@article {pmid38636949, year = {2024}, author = {Deore, P and Tsang Min Ching, SJ and Nitschke, MR and Rudd, D and Brumley, DR and Hinde, E and Blackall, LL and van Oppen, MJH}, title = {Unique photosynthetic strategies employed by closely related Breviolum minutum strains under rapid short-term cumulative heat stress.}, journal = {Journal of experimental botany}, volume = {}, number = {}, pages = {}, doi = {10.1093/jxb/erae170}, pmid = {38636949}, issn = {1460-2431}, abstract = {The thermal tolerance of symbiodiniacean photo-endosymbionts largely underpins the thermal bleaching resilience of their cnidarian hosts such as corals and the coral model, Exaiptasia diaphana. While variation in thermal tolerance between species is well documented, variation between conspecific strains is understudied. We compared the thermal tolerance of three closely related strains of Breviolum minutum represented by two internal transcribed spacer region 2 profiles (one strain B1-B1o-B1g-B1p and the other two strains B1-B1a-B1b-1g) and differences in photochemical and non-photochemical quenching, de-epoxidation state of photopigments, and accumulation of reactive oxygen species under rapid short-term cumulative temperature stress (26-40°C). We found that B. minutum strains employ distinct photoprotective strategies, resulting in different upper thermal tolerances. We provide evidence for previously unknown interdependencies between thermal tolerance traits and photoprotective mechanisms which include a delicate balancing of excitation energy and its dissipation through fast relaxing and state transition components of non-photochemical quenching. The more thermally tolerant B. minutum strain (B1-B1o-B1g-B1p) exhibited an enhanced de-epoxidation that is strongly linked to the thylakoid membrane melting point and possibly membrane rigidification minimising oxidative damage. This study provides an in-depth understanding of photoprotective mechanisms underpinning thermal tolerance in closely related strains of B. minutum.}, }
@article {pmid38632506, year = {2024}, author = {Alkathiry, HA and Alghamdi, SQ and Sinha, A and Margos, G and Stekolnikov, AA and Alagaili, AN and Darby, AC and Makepeace, BL and Khoo, JJ}, title = {Microbiome and mitogenomics of the chigger mite Pentidionis agamae: potential role as an Orientia vector and associations with divergent clades of Wolbachia and Borrelia.}, journal = {BMC genomics}, volume = {25}, number = {1}, pages = {380}, pmid = {38632506}, issn = {1471-2164}, abstract = {BACKGROUND: Trombiculid mites are globally distributed, highly diverse arachnids that largely lack molecular resources such as whole mitogenomes for the elucidation of taxonomic relationships. Trombiculid larvae (chiggers) parasitise vertebrates and can transmit bacteria (Orientia spp.) responsible for scrub typhus, a zoonotic febrile illness. Orientia tsutsugamushi causes most cases of scrub typhus and is endemic to the Asia-Pacific Region, where it is transmitted by Leptotrombidium spp. chiggers. However, in Dubai, Candidatus Orientia chuto was isolated from a case of scrub typhus and is also known to circulate among rodents in Saudi Arabia and Kenya, although its vectors remain poorly defined. In addition to Orientia, chiggers are often infected with other potential pathogens or arthropod-specific endosymbionts, but their significance for trombiculid biology and public health is unclear.<br><br>RESULTS: Ten chigger species were collected from rodents in southwestern Saudi Arabia. Chiggers were pooled according to species and screened for Orientia DNA by PCR. Two species (Microtrombicula muhaylensis and Pentidionis agamae) produced positive results for the htrA gene, although Ca. Orientia chuto DNA was confirmed by Sanger sequencing only in P. agamae. Metagenomic sequencing of three pools of P. agamae provided evidence for two other bacterial associates: a spirochaete and a Wolbachia symbiont. Phylogenetic analysis of 16S rRNA and multi-locus sequence typing genes placed the spirochaete in a clade of micromammal-associated Borrelia spp. that are widely-distributed globally with no known vector. For the Wolbachia symbiont, a genome assembly was obtained that allowed phylogenetic localisation in a novel, divergent clade. Cytochrome c oxidase I (COI) barcodes for Saudi Arabian chiggers enabled comparisons with global chigger diversity, revealing several cases of discordance with classical taxonomy. Complete mitogenome assemblies were obtained for the three P. agamae pools and almost 50 SNPs were identified, despite a common geographic origin.<br><br>CONCLUSIONS: P. agamae was identified as a potential vector of Ca. Orientia chuto on the Arabian Peninsula. The detection of an unusual Borrelia sp. and a divergent Wolbachia symbiont in P. agamae indicated links with chigger microbiomes in other parts of the world, while COI barcoding and mitogenomic analyses greatly extended our understanding of inter- and intraspecific relationships in trombiculid mites.}, }
@article {pmid38632047, year = {2024}, author = {Arai, H and Legeai, F and Kageyama, D and Sugio, A and Simon, JC}, title = {Genomic insights into Spiroplasma endosymbionts that induce male-killing and protective phenotypes in the pea aphid.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnae027}, pmid = {38632047}, issn = {1574-6968}, abstract = {The endosymbiotic bacteria Spiroplasma (Mollicutes) infect diverse plants and arthropods, and some of which induce male killing, where male hosts are killed during development. Male-killing Spiroplasma strains belong to either the phylogenetically distant Citri-Poulsonii or Ixodetis groups. In Drosophila flies, Spiroplasma poulsonii induces male killing via the Spaid toxin. While Spiroplasma ixodetis infects a wide range of insects and arachnids, little is known about the genetic basis of S. ixodetis-induced male killing. Here, we analyzed the genome of S. ixodetis strains in the pea aphid Acyrthosiphon pisum (Aphididae, Hemiptera). Genome sequencing constructed a complete genome of a male-killing strain, sAp269, consisting of a 1.5 Mb circular chromosome and an 80 Kb plasmid. sAp269 encoded putative virulence factors containing either ankyrin repeat, ovarian tumor-like deubiquitinase, or ribosome inactivating protein domains, but lacked the Spaid toxin. Further comparative genomics of Spiroplasma strains in A. pisum biotypes adapted to different host plants revealed their phylogenetic associations and the diversity of putative virulence factors. Although the mechanisms of S. ixodetis-induced male killing in pea aphids remain elusive, this study underlines the dynamic genome evolution of S. ixodetis and proposes independent acquisition events of male-killing mechanisms in insects.}, }
@article {pmid38630610, year = {2024}, author = {Pilgrim, J}, title = {Comparative genomics of a novel Erwinia species associated with the Highland midge (Culicoides impunctatus).}, journal = {Microbial genomics}, volume = {10}, number = {4}, pages = {}, doi = {10.1099/mgen.0.001242}, pmid = {38630610}, issn = {2057-5858}, abstract = {Erwinia (Enterobacterales: Erwiniaceae) are a group of cosmopolitan bacteria best known as the causative agents of various plant diseases. However, other species in this genus have been found to play important roles as insect endosymbionts supplementing the diet of their hosts. Here, I describe Candidatus Erwinia impunctatus (Erwimp) associated with the Highland midge Culicoides impunctatus (Diptera: Ceratopogonidae), an abundant biting pest in the Scottish Highlands. The genome of this new Erwinia species was assembled using hybrid long and short read techniques, and a comparative analysis was undertaken with other members of the genus to understand its potential ecological niche and impact. Genome composition analysis revealed that Erwimp is similar to other endophytic and ectophytic species in the genus and is unlikely to be restricted to its insect host. Evidence for an additional plant host includes the presence of a carotenoid synthesis operon implicated as a virulence factor in plant-associated members in the sister genus Pantoea. Unique features of Erwimp include several copies of intimin-like proteins which, along with signs of genome pseudogenization and a loss of certain metabolic pathways, suggests an element of host restriction seen elsewhere in the genus. Furthermore, a screening of individuals over two field seasons revealed the absence of the bacteria in Culicoides impunctatus during the second year indicating this microbe-insect interaction is likely to be transient. These data suggest that Culicoides impunctatus may have an important role to play beyond a biting nuisance, as an insect vector transmitting Erwimp alongside any conferred impacts to surrounding biota.}, }
@article {pmid38629270, year = {2024}, author = {Nakajima, H and Fukui, A and Suzuki, K and Tirta, RYK and Furuya, H}, title = {HOST SWITCHING IN DICYEMIDS (PHYLUM DICYEMIDA).}, journal = {The Journal of parasitology}, volume = {110}, number = {2}, pages = {159-169}, doi = {10.1645/23-52}, pmid = {38629270}, issn = {1937-2345}, abstract = {Dicyemids (phylum Dicyemida) are the most common and most characteristic endosymbionts in the renal sacs of benthic cephalopod molluscs: octopuses and cuttlefishes. Typically, 2 or 3 dicyemid species are found in a single specimen of the host, and most dicyemids have high host specificity. Host-specific parasites are restricted to a limited range of host species by ecological barriers that impede dispersal and successful establishment; therefore, phylogenies of interacting groups are often congruent due to repeated co-speciation. Most frequently, however, host and parasite phylogenies are not congruent, which can be explained by processes such as host switching and other macro-evolutionary events. Here, the history of dicyemids and their host cephalopod associations were studied by comparing their phylogenies. Dicyemid species were collected from 8 decapodiform species and 12 octopodiform species in Japanese waters. Using whole mitochondrial cytochrome c oxidase subunit 1 (COI) sequences, a phylogeny of 37 dicyemid species, including 4 genera representing the family Dicyemidae, was reconstructed. Phylogenetic trees derived from analyses of COI genes consistently suggested that dicyemid species should be separated into 3 major clades and that the most common genera, Dicyema and Dicyemennea, are not monophyletic. Thus, morphological classification does not reflect the phylogenetic relationships of these 2 genera. Divergence (speciation) of dicyemid species seems to have occurred within a single host species. Possible host-switching events may have occurred between the Octopodiformes and Decapodiformes or within the Octopodiformes or the Decapodiformes. Therefore, the mechanism of dicyemid speciation may be a mixture of host switching and intra-host speciation. This is the first study in which the process of dicyemid diversification involving cephalopod hosts has been evaluated with a large number of dicyemid species and genera.}, }
@article {pmid38629189, year = {2024}, author = {Bard, NW and Cronk, QCB and Davies, TJ}, title = {Fungal endophytes can modulate plant invasion.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {}, number = {}, pages = {}, doi = {10.1111/brv.13085}, pmid = {38629189}, issn = {1469-185X}, support = {RGPIN-2019-04041//Natural Sciences and Engineering Research Council of Canada/ ; RGPIN-2020-04439//Natural Sciences and Engineering Research Council of Canada/ ; 6456//University of British Columbia Graduate School/ ; }, abstract = {Symbiotic organisms may contribute to a host plant's success or failure to grow, its ability to maintain viable populations, and potentially, its probability of establishment and spread outside its native range. Intercellular and intracellular microbial symbionts that are asymptomatic in their plant host during some or all of their life cycle - endophytes - can form mutualistic, commensal, or pathogenic relationships, and sometimes novel associations with alien plants. Fungal endophytes are likely the most common endosymbiont infecting plants, with life-history, morphological, physiological, and plant-symbiotic traits that are distinct from other endophytic guilds. Here, we review the community dynamics of fungal endophytes during the process of plant invasion, and how their functional role may shift during the different stages of invasion: transport, introduction (colonisation), establishment, and spread. Each invasion stage presents distinct ecological filters that an alien plant must overcome to advance to the subsequent stage of invasion. Endophytes can alternately aid the host in overcoming stage-specific filters, or contribute to the barriers imposed by filters (e.g. biotic resistance), thereby affecting invasion pathways. A few fungi can be transported as seed endophytes from their native range and be vertically transmitted to future generations in the non-native range, especially in graminoids. In other plant groups, alien plants mostly acquire endophytes via horizontal transmission from the invaded plant community, and the host endophyte community is shaped by host filtering and biogeographic factors (e.g. dispersal limitation, environmental filtering). Endophytes infecting alien plants (both those transported with their host and those accumulated in the non-native range) may influence invasion success by affecting plant growth, reproduction, environmental tolerance, and pathogen and herbivory defences; however, the direction and magnitude of these effects can be contingent upon the host identity, life stage, ecological conditions, and invasion stage. This context dependence may cause endophytic fungi to shift to a non-endophytic (e.g. pathogenic) functional life stage in the same or different hosts, which can modify alien-native plant community dynamics. We conclude by identifying paths in which alien hosts can exploit the context dependency of endophyte function in novel abiotic and biotic conditions and at the different stages of invasion.}, }
@article {pmid38627945, year = {2024}, author = {Rooney, T and Fèvre, EM and Villinger, J and Brenn-White, M and Cummings, CO and Chai, D and Kamau, J and Kiyong'a, A and Getange, D and Ochieng, DO and Kivali, V and Zimmerman, D and Rosenbaum, M and Nutter, FB and Deem, SL}, title = {Coxiella burnetii serostatus in dromedary camels (Camelus dromedarius) is associated with the presence of C. burnetii DNA in attached ticks in Laikipia County, Kenya.}, journal = {Zoonoses and public health}, volume = {}, number = {}, pages = {}, doi = {10.1111/zph.13127}, pmid = {38627945}, issn = {1863-2378}, support = {//Saint Louis Zoo Institution for Conservation Medicine/ ; //National Institute of Health's Summer Training Grant/ ; //European Union's Horizon 2020 research and innovation programme/ ; //icipe institutional funding from the Swedish International Development Cooperation Agency (SIDA)/ ; //The Swiss Agency for Development and Cooperation (SDC)/ ; //The Federal Democratic Republic of Ethiopia/ ; //The Government of the Republic of Kenya/ ; //CGIAR One Health initiative "Protecting Human Health Through a One Health Approach"/ ; }, abstract = {AIMS: Q fever is a globally distributed, neglected zoonotic disease of conservation and public health importance, caused by the bacterium Coxiella burnetii. Coxiella burnetii normally causes subclinical infections in livestock, but may also cause reproductive pathology and spontaneous abortions in artiodactyl species. One such artiodactyl, the dromedary camel (Camelus dromedarius), is an increasingly important livestock species in semi-arid landscapes. Ticks are naturally infected with C. burnetii worldwide and are frequently found on camels in Kenya. In this study, we assessed the relationship between dromedary camels' C. burnetii serostatus and whether the camels were carrying C. burnetii PCR-positive ticks in Kenya. We hypothesized that there would be a positive association between camel seropositivity and carrying C. burnetii PCR-positive ticks.<br><br>METHODS AND RESULTS: Blood was collected from camels (N&#x2009;=&#x2009;233) from three herds, and serum was analysed using commercial ELISA antibody test kits. Ticks were collected (N&#x2009;=&#x2009;4354), divided into pools of the same species from the same camel (N&#x2009;=&#x2009;397) and tested for C. burnetii and Coxiella-like endosymbionts. Descriptive statistics were used to summarize seroprevalence by camel demographic and clinical variables. Univariate logistic regression analyses were used to assess relationships between serostatus (outcome) and tick PCR status, camel demographic variables, and camel clinical variables (predictors). Camel C. burnetii seroprevalence was 52%. Across tick pools, the prevalence of C. burnetii was 15% and Coxiella-like endosymbionts was 27%. Camel seropositivity was significantly associated with the presence of a C. burnetii PCR-positive tick pool (OR: 2.58; 95% CI: 1.4-5.1; p&#x2009;=&#x2009;0.0045), increasing age class, and increasing total solids.<br><br>CONCLUSIONS: The role of ticks and camels in the epidemiology of Q fever warrants further research to better understand this zoonotic disease that has potential to cause illness and reproductive losses in humans, livestock, and wildlife.}, }
@article {pmid38626194, year = {2024}, author = {McCutcheon, JP and Garber, AI and Spencer, N and Warren, JM}, title = {How do bacterial endosymbionts work with so few genes?.}, journal = {PLoS biology}, volume = {22}, number = {4}, pages = {e3002577}, doi = {10.1371/journal.pbio.3002577}, pmid = {38626194}, issn = {1545-7885}, abstract = {The move from a free-living environment to a long-term residence inside a host eukaryotic cell has profound effects on bacterial function. While endosymbioses are found in many eukaryotes, from protists to plants to animals, the bacteria that form these host-beneficial relationships are even more diverse. Endosymbiont genomes can become radically smaller than their free-living relatives, and their few remaining genes show extreme compositional biases. The details of how these reduced and divergent gene sets work, and how they interact with their host cell, remain mysterious. This Unsolved Mystery reviews how genome reduction alters endosymbiont biology and highlights a "tipping point" where the loss of the ability to build a cell envelope coincides with a marked erosion of translation-related genes.}, }
@article {pmid38623496, year = {2024}, author = {Marulanda-Moreno, SM and Saldamando-Benjumea, CI and Vivero Gomez, R and Cadavid-Restrepo, G and Moreno-Herrera, CX}, title = {Comparative analysis of Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) corn and rice strains microbiota revealed minor changes across life cycle and strain endosymbiont association.}, journal = {PeerJ}, volume = {12}, number = {}, pages = {e17087}, doi = {10.7717/peerj.17087}, pmid = {38623496}, issn = {2167-8359}, abstract = {BACKGROUND: Spodoptera frugiperda (FAW) is a pest that poses a significant threat to corn production worldwide, causing millions of dollars in losses. The species has evolved into two strains (corn and rice) that differ in their genetics, reproductive isolation, and resistance to insecticides and Bacillus thuringiensis endotoxins. The microbiota plays an important role in insects' physiology, nutrient acquisition, and response to chemical and biological controls. Several studies have been carried out on FAW microbiota from larvae guts using laboratory or field samples and a couple of studies have analyzed the corn strain microbiota across its life cycle. This investigation reveals the first comparison between corn strain (CS) and rice strain (RS) of FAW during different developmental insect stages and, more importantly, endosymbiont detection in both strains, highlighting the importance of studying both FAW populations and samples from different stages.<br><br>METHODS: The composition of microbiota during the life cycle of the FAW corn and rice strains was analyzed through high-throughput sequencing of the bacterial 16S rRNA gene using the MiSeq system. Additionally, culture-dependent techniques were used to isolate gut bacteria and the Transcribed Internal Spacer-ITS, 16S rRNA, and gyrB genes were examined to enhance bacterial identification.<br><br>RESULTS: Richness, diversity, and bacterial composition changed significantly across the life cycle of FAW. Most diversity was observed in eggs and males. Differences in gut microbiota diversity between CS and RS were minor. However, Leuconostoc, A2, Klebsiella, Lachnoclostridium, Spiroplasma, and Mucispirilum were mainly associated with RS and Colidextribacter, Pelomonas, Weissella, and Arsenophonus to CS, suggesting that FAW strains differ in several genera according to the host plant. Firmicutes and Proteobacteria were the dominant phyla during FAW metamorphosis. Illeobacterium, Ralstonia, and Burkholderia exhibited similar abundancies in both strains. Enterococcus was identified as a conserved taxon across the entire FAW life cycle. Microbiota core communities mainly consisted of Enterococcus and Illeobacterium. A positive correlation was found between Spiroplasma with RS (sampled from eggs, larvae, pupae, and adults) and Arsenophonus (sampled from eggs, larvae, and adults) with CS. Enterococcus mundtii was predominant in all developmental stages. Previous studies have suggested its importance in FAW response to B. thuringensis. Our results are relevant for the characterization of FAW corn and rice strains microbiota to develop new strategies for their control. Detection of Arsenophonus in CS and Spiroplasma in RS are promising for the improvement of this pest management, as these bacteria induce male killing and larvae fitness reduction in other Lepidoptera species.}, }
@article {pmid38617467, year = {2024}, author = {Vancaester, E and Blaxter, ML}, title = {MarkerScan: Separation and assembly of cobionts sequenced alongside target species in biodiversity genomics projects.}, journal = {Wellcome open research}, volume = {9}, number = {}, pages = {33}, pmid = {38617467}, issn = {2398-502X}, abstract = {Contamination of public databases by mislabelled sequences has been highlighted for many years and the avalanche of novel sequencing data now being deposited has the potential to make databases difficult to use effectively. It is therefore crucial that sequencing projects and database curators perform pre-submission checks to remove obvious contamination and avoid propagating erroneous taxonomic relationships. However, it is important also to recognise that biological contamination of a target sample with unexpected species' DNA can also lead to the discovery of fascinating biological phenomena through the identification of environmental organisms or endosymbionts. Here, we present a novel, integrated method for detection and generation of high-quality genomes of all non-target genomes co-sequenced in eukaryotic genome sequencing projects. After performing taxonomic profiling of an assembly from the raw data, and leveraging the identity of small rRNA sequences discovered therein as markers, a targeted classification approach retrieves and assembles high-quality genomes. The genomes of these cobionts are then not only removed from the target species' genome but also available for further interrogation. Source code is available from https://github.com/CobiontID/MarkerScan. MarkerScan is written in Python and is deployed as a Docker container.}, }
@article {pmid38617242, year = {2024}, author = {Mallikaarachchi, KS and Huang, JL and Madras, S and Cuellar, RA and Huang, Z and Gega, A and Rathnayaka-Mudiyanselage, IW and Al-Husini, N and Saldaña-Rivera, N and Ma, LH and Ng, E and Chen, JC and Schrader, JM}, title = {Sinorhizobium meliloti BR-bodies promote fitness during host colonization.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.04.05.588320}, pmid = {38617242}, abstract = {UNLABELLED: Biomolecular condensates, such as the nucleoli or P-bodies, are non-membrane-bound assemblies of proteins and nucleic acids that facilitate specific cellular processes. Like eukaryotic P-bodies, the recently discovered bacterial ribonucleoprotein bodies (BR-bodies) organize the mRNA decay machinery, yet the similarities in molecular and cellular functions across species have been poorly explored. Here, we examine the functions of BR-bodies in the nitrogen-fixing endosymbiont Sinorhizobium meliloti , which colonizes the roots of compatible legume plants. Assembly of BR-bodies into visible foci in S. meliloti cells requires the C-terminal intrinsically disordered region (IDR) of RNase E, and foci fusion is readily observed in vivo , suggesting they are liquid-like condensates that form via mRNA sequestration. Using Rif-seq to measure mRNA lifetimes, we found a global slowdown in mRNA decay in a mutant deficient in BR-bodies, indicating that compartmentalization of the degradation machinery promotes efficient mRNA turnover. While BR-bodies are constitutively present during exponential growth, the abundance of BR-bodies increases upon cell stress, whereby they promote stress resistance. Finally, using Medicago truncatula as host, we show that BR-bodies enhance competitiveness during colonization and appear to be required for effective symbiosis, as mutants without BR-bodies failed to stimulate plant growth. These results suggest that BR-bodies provide a fitness advantage for bacteria during infection, perhaps by enabling better resistance against the host immune response.<br><br>SIGNIFICANCE: While eukaryotes often organize their biochemical pathways in membrane-bound organelles, bacteria generally lack such subcellular structures. Instead, membraneless compartments called biomolecular condensates have recently been found in bacteria to enhance biochemical activities. Bacterial ribonucleoprotein bodies (BR-bodies), as one of the most widespread biomolecular condensates identified to date, assemble the mRNA decay machinery via the intrinsically disordered regions (IDRs) of proteins. However, the implications of such assemblies are unclear. Using a plant-associated symbiont, we show that the IDR of its mRNA degradation protein is necessary for condensate formation. Absence of BR-bodies results in slower mRNA decay and ineffective symbiosis, suggesting that BR-bodies play critical roles in regulating biochemical pathways and promoting fitness during host colonization.}, }
@article {pmid38609398, year = {2024}, author = {Mowery, MA and Rosenwald, LC and Chapman, E and Lubin, Y and Segoli, M and Khoza, T and Lyle, R and White, JA}, title = {Endosymbiont diversity across native and invasive brown widow spider populations.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {8556}, pmid = {38609398}, issn = {2045-2322}, support = {1953223//National Science Foundation/ ; 1020740//National Institute of Food and Agriculture/ ; }, mesh = {Humans ; Adult ; Animals ; Female ; *Animals, Poisonous ; *Chlamydiales ; Eggs ; *Spiders ; *Wolbachia ; }, abstract = {The invasive brown widow spider, Latrodectus geometricus (Araneae: Theridiidae), has spread in multiple locations around the world and, along with it, brought associated organisms such as endosymbionts. We investigated endosymbiont diversity and prevalence across putative native and invasive populations of this spider, predicting lower endosymbiont diversity across the invasive range compared to the native range. First, we characterized the microbial community in the putative native (South Africa) and invasive (Israel and the United States) ranges via high throughput 16S sequencing of 103 adult females. All specimens were dominated by reads from only 1-3 amplicon sequence variants (ASV), and most individuals were infected with an apparently uniform strain of Rhabdochlamydia. We also found Rhabdochlamydia in spider eggs, indicating that it is a maternally-inherited endosymbiont. Relatively few other ASV were detected, but included two variant Rhabdochlamydia strains and several Wolbachia, Spiroplasma and Enterobacteriaceae strains. We then diagnostically screened 118 adult female spiders from native and invasive populations specifically for Rhabdochlamydia and Wolbachia. We found Rhabdochlamydia in 86% of individuals and represented in all populations, which suggests that it is a consistent and potentially important associate of L. geometricus. Wolbachia was found at lower overall prevalence (14%) and was represented in all countries, but not all populations. In addition, we found evidence for geographic variation in endosymbiont prevalence: spiders from Israel were more likely to carry Rhabdochlamydia than those from the US and South Africa, and Wolbachia was geographically clustered in both Israel and South Africa. Characterizing endosymbiont prevalence and diversity is a first step in understanding their function inside the host and may shed light on the process of spread and population variability in cosmopolitan invasive species.}, }
@article {pmid38608678, year = {2024}, author = {Trznadel, M and Holt, CC and Livingston, SJ and Kwong, WK and Keeling, PJ}, title = {Coral-infecting parasites in cold marine ecosystems.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2024.03.026}, pmid = {38608678}, issn = {1879-0445}, abstract = {Coral reefs are a biodiversity hotspot,[1][,][2] and the association between coral and intracellular dinoflagellates is a model for endosymbiosis.[3][,][4] Recently, corals and related anthozoans have also been found to harbor another kind of endosymbiont, apicomplexans called corallicolids.[5] Apicomplexans are a diverse lineage of obligate intracellular parasites[6] that include human pathogens such as the malaria parasite, Plasmodium.[7] Global environmental sequencing shows corallicolids are tightly associated with tropical and subtropical reef environments,[5][,][8][,][9] where they infect diverse corals across a range of depths in many reef systems, and correlate with host mortality during bleaching events.[10] All of this points to corallicolids being ecologically significant to coral reefs, but it is also possible they are even more widely distributed because most environmental sampling is biased against parasites that maintain a tight association with their hosts throughout their life cycle. We tested the global distribution of corallicolids using a more direct approach, by specifically targeting potential anthozoan host animals from cold/temperate marine waters outside the coral reef context. We found that corallicolids are in fact common in such hosts, in some cases at high frequency, and that they infect the same tissue as parasites from topical coral reefs. Parasite phylogeny suggests corallicolids move between hosts and habitats relatively frequently, but that biogeography is more conserved. Overall, these results greatly expand the range of corallicolids beyond coral reefs, suggesting they are globally distributed parasites of marine anthozoans, which also illustrates significant blind spots that result from strategies commonly used to sample microbial biodiversity.}, }
@article {pmid38607980, year = {2024}, author = {Partida-Martínez, LP}, title = {Fungal holobionts as blueprints for synthetic endosymbiotic systems.}, journal = {PLoS biology}, volume = {22}, number = {4}, pages = {e3002587}, doi = {10.1371/journal.pbio.3002587}, pmid = {38607980}, issn = {1545-7885}, abstract = {Rhizopus microsporus is an example of a fungal holobiont. Strains of this species can harbor bacterial and viral endosymbionts inherited by the next generation. These microbial allies increase pathogenicity and defense and control asexual and sexual reproduction.}, }
@article {pmid38603513, year = {2024}, author = {Massana, R}, title = {The nitroplast: A nitrogen-fixing organelle.}, journal = {Science (New York, N.Y.)}, volume = {384}, number = {6692}, pages = {160-161}, doi = {10.1126/science.ado8571}, pmid = {38603513}, issn = {1095-9203}, abstract = {A bacterial endosymbiont of marine algae evolved to an organelle.}, }
@article {pmid38603509, year = {2024}, author = {Coale, TH and Loconte, V and Turk-Kubo, KA and Vanslembrouck, B and Mak, WKE and Cheung, S and Ekman, A and Chen, JH and Hagino, K and Takano, Y and Nishimura, T and Adachi, M and Le Gros, M and Larabell, C and Zehr, JP}, title = {Nitrogen-fixing organelle in a marine alga.}, journal = {Science (New York, N.Y.)}, volume = {384}, number = {6692}, pages = {217-222}, doi = {10.1126/science.adk1075}, pmid = {38603509}, issn = {1095-9203}, abstract = {Symbiotic interactions were key to the evolution of chloroplast and mitochondria organelles, which mediate carbon and energy metabolism in eukaryotes. Biological nitrogen fixation, the reduction of abundant atmospheric nitrogen gas (N2) to biologically available ammonia, is a key metabolic process performed exclusively by prokaryotes. Candidatus Atelocyanobacterium thalassa, or UCYN-A, is a metabolically streamlined N2-fixing cyanobacterium previously reported to be an endosymbiont of a marine unicellular alga. Here we show that UCYN-A has been tightly integrated into algal cell architecture and organellar division and that it imports proteins encoded by the algal genome. These are characteristics of organelles and show that UCYN-A has evolved beyond endosymbiosis and functions as an early evolutionary stage N2-fixing organelle, or "nitroplast."}, }
@article {pmid38601947, year = {2023}, author = {Zytynska, SE and Sturm, S and Hawes, C and Weisser, WW and Karley, A}, title = {Floral presence and flower identity alter cereal aphid endosymbiont communities on adjacent crops.}, journal = {The Journal of applied ecology}, volume = {60}, number = {7}, pages = {1409-1423}, pmid = {38601947}, issn = {0021-8901}, abstract = {Floral plantings adjacent to crops fields can recruit populations of natural enemies by providing flower nectar and non-crop prey to increase natural pest regulation. Observed variation in success rates might be due to changes in the unseen community of endosymbionts hosted by many herbivorous insects, of which some can confer resistance to natural enemies, for example, parasitoid wasps. Reduced insect control may occur if highly protective symbiont combinations increase in frequency via selection effects, and this is expected to be stronger in lower diversity systems.We used a large-scale field trial to analyse the bacterial endosymbiont communities hosted by cereal aphids Sitobion avenae collected along transects into strip plots of barley plants managed by either conventional or integrated (including floral field margins and reduced inputs) methods. In addition, we conducted an outdoor pot experiment to analyse endosymbionts in S. avenae aphids collected on barley plants that were either grown alone or alongside one of three flowering plants, across three time points.In the field, aphids hosted up to four symbionts. The abundance of aphids and parasitoid wasps was reduced towards the middle of all fields while aphid symbiont species richness and diversity decreased into the field in conventional, but not integrated, field-strips. The proportion of aphids hosting different symbiont combinations varied across cropping systems, with distances into the fields, and were correlated with parasitoid wasp abundances.In the pot experiment, aphids hosted up to six symbionts. Flower presence increased natural enemy abundance and diversity, and decreased aphid abundance. The proportion of aphids hosting different symbiont combinations varied across the flower treatment and time, and were correlated with varying abundances of the different specialist parasitoid wasp species recruited by different flowers. Synthesis and applications. Floral plantings and flower identity had community-wide impacts on the combinations of bacterial endosymbionts hosted by herbivorous insects, which correlated with natural enemy diversity and abundance. We recommend that integrated management practices incorporate floral resources within field areas to support a more functionally diverse and resilient natural enemy community to mitigate selection for symbiont-mediated pest resistance throughout the cropping area.}, }
@article {pmid38598600, year = {2024}, author = {Wang, H and Marucci, G and Munke, A and Hassan, MM and Lalle, M and Okamoto, K}, title = {High-resolution comparative atomic structures of two Giardiavirus prototypes infecting G. duodenalis parasite.}, journal = {PLoS pathogens}, volume = {20}, number = {4}, pages = {e1012140}, doi = {10.1371/journal.ppat.1012140}, pmid = {38598600}, issn = {1553-7374}, abstract = {The Giardia lamblia virus (GLV) is a non-enveloped icosahedral dsRNA and endosymbiont virus that infects the zoonotic protozoan parasite Giardia duodenalis (syn. G. lamblia, G. intestinalis), which is a pathogen of mammals, including humans. Elucidating the transmission mechanism of GLV is crucial for gaining an in-depth understanding of the virulence of the virus in G. duodenalis. GLV belongs to the family Totiviridae, which infects yeast and protozoa intracellularly; however, it also transmits extracellularly, similar to the phylogenetically, distantly related toti-like viruses that infect multicellular hosts. The GLV capsid structure is extensively involved in the longstanding discussion concerning extracellular transmission in Totiviridae and toti-like viruses. Hence, this study constructed the first high-resolution comparative atomic models of two GLV strains, namely GLV-HP and GLV-CAT, which showed different intracellular localization and virulence phenotypes, using cryogenic electron microscopy single-particle analysis. The atomic models of the GLV capsids presented swapped C-terminal extensions, extra surface loops, and a lack of cap-snatching pockets, similar to those of toti-like viruses. However, their open pores and absence of the extra crown protein resemble those of other yeast and protozoan Totiviridae viruses, demonstrating the essential structures for extracellular cell-to-cell transmission. The structural comparison between GLV-HP and GLV-CAT indicates the first evidence of critical structural motifs for the transmission and virulence of GLV in G. duodenalis.}, }
@article {pmid38597256, year = {2024}, author = {Fox, T and Sguassero, Y and Chaplin, M and Rose, W and Doum, D and Arevalo-Rodriguez, I and Villanueva, G}, title = {Wolbachia-carrying Aedes mosquitoes for preventing dengue infection.}, journal = {The Cochrane database of systematic reviews}, volume = {4}, number = {}, pages = {CD015636}, doi = {10.1002/14651858.CD015636.pub2}, pmid = {38597256}, issn = {1469-493X}, abstract = {BACKGROUND: Dengue is a global health problem of high significance, with 3.9 billion people at risk of infection. The geographic expansion of dengue virus (DENV) infection has resulted in increased frequency and severity of the disease, and the number of deaths has increased in recent years. Wolbachia,an intracellular bacterial endosymbiont, has been under investigation for several years as a novel dengue-control strategy. Some dengue vectors (Aedes mosquitoes) can be transinfected with specific strains of Wolbachia, which decreases their fitness (ability to survive and mate) and their ability to reproduce, inhibiting the replication of dengue. Both laboratory and field studies have demonstrated the potential effect of Wolbachia deployments on reducing dengue transmission, and modelling studies have suggested that this may be a self-sustaining strategy for dengue prevention, although long-term effects are yet to be elucidated.<br><br>OBJECTIVES: To assess the efficacy of Wolbachia-carrying Aedes speciesdeployments (specifically wMel-, wMelPop-, and wAlbB- strains of Wolbachia) for preventing dengue virus infection.<br><br>SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, four other databases, and two trial registries up to 24 January 2024.<br><br>SELECTION CRITERIA: Randomized controlled trials (RCTs), including cluster-randomized controlled trials (cRCTs), conducted in dengue endemic or epidemic-prone settings were eligible. We sought studies that investigated the impact of Wolbachia-carrying Aedes deployments on epidemiological or entomological dengue-related outcomes, utilizing either the population replacement or population suppression strategy.<br><br>DATA COLLECTION AND ANALYSIS: Two review authors independently selected eligible studies, extracted data, and assessed the risk of bias using the Cochrane RoB 2 tool. We used odds ratios (OR) with the corresponding 95% confidence intervals (CI) as the effect measure for dichotomous outcomes. For count/rate outcomes, we planned to use the rate ratio with 95% CI as the effect measure. We used adjusted measures of effect for cRCTs. We assessed the certainty of evidence using GRADE.<br><br>MAIN RESULTS: One completed cRCT met our inclusion criteria, and we identified two further ongoing cRCTs. The included trial was conducted in an urban setting in Yogyakarta, Indonesia. It utilized a nested test-negative study design, whereby all participants aged three to 45 years who presented at healthcare centres with a fever were enrolled in the study provided they had resided in the study area for the previous 10 nights. The trial showed that wMel-Wolbachia infected Ae aegypti deployments probably reduce the odds of contracting virologically confirmed dengue by 77% (OR 0.23, 95% CI 0.15 to 0.35; 1 trial, 6306 participants; moderate-certainty evidence). The cluster-level prevalence of wMel Wolbachia-carrying mosquitoes remained high over two years in the intervention arm of the trial, reported as 95.8% (interquartile range 91.5 to 97.8) across 27 months in clusters receiving wMel-Wolbachia Ae aegypti deployments, but there were no reliable comparative data for this outcome. Other primary outcomes were the incidence of virologically confirmed dengue, the prevalence of dengue ribonucleic acid in the mosquito population, and mosquito density, but there were no data for these outcomes. Additionally, there were no data on adverse events.<br><br>AUTHORS' CONCLUSIONS: The included trial demonstrates the potential significant impact of wMel-Wolbachia-carrying Ae aegypti mosquitoes on preventing dengue infection in an endemic setting, and supports evidence reported in non-randomized and uncontrolled studies. Further trials across a greater diversity of settings are required to confirm whether these findings apply to other locations and country settings, and greater reporting of acceptability and cost are important.}, }
@article {pmid38585949, year = {2024}, author = {Mirchandani, C and Wang, P and Jacobs, J and Genetti, M and Pepper-Tunick, E and Sullivan, WT and Corbett-Detig, R and Russell, SL}, title = {Mixed Wolbachia infections resolve rapidly during in vitro evolution.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.03.27.586911}, pmid = {38585949}, abstract = {UNLABELLED: The intracellular symbiont Wolbachia pipientis evolved after the divergence of arthropods and nematodes, but it reached high prevalence in many of these taxa through its abilities to infect new hosts and their germlines. Some strains exhibit long-term patterns of co-evolution with their hosts, while other strains are capable of switching hosts. This makes strain selection an important factor in symbiont-based biological control. However, little is known about the ecological and evolutionary interactions that occur when a promiscuous strain colonizes an infected host. Here, we study what occurs when two strains come into contact in host cells following horizontal transmission and infection. We focus on the faithful w Mel strain from Drosophila melanogaster and the promiscuous w Ri strain from Drosophila simulans using an in vitro cell culture system with multiple host cell types and combinatorial infection states. Mixing D. melanogaster cell lines stably infected with w Mel and w Ri revealed that wMel outcompetes w Ri quickly and reproducibly. Furthermore, w Mel was able to competitively exclude w Ri even from minuscule starting quantities, indicating that this is a nearly deterministic outcome, independent of the starting infection frequency. This competitive advantage was not exclusive to wM el's native D. melanogaster cell background, as w Mel also outgrew w Ri in D. simulans cells. Overall, w Ri is less adept at i n vitro growth and survival than w Mel and its in vivo state, revealing differences between cellular and humoral regulation. These attributes may underlie the observed low rate of mixed infections in nature and the relatively rare rate of host-switching in most strains. Our in vitro experimental framework for estimating cellular growth dynamics of Wolbachia strains in different host species, tissues, and cell types provides the first strategy for parameterizing endosymbiont and host cell biology at high resolution. This toolset will be crucial to our application of these bacteria as biological control agents in novel hosts and ecosystems.<br><br>AUTHOR SUMMARY: Wolbachia pipientis is one of the most common bacterial endosymbionts due to its ability to manipulate host reproduction, and it has become a useful biological control tool for mosquito populations. Wolbachia is passed from mother to offspring, however the bacterium can also "jump" to new hosts via horizontal transmission. When a Wolbachia strain successfully infects a new host, it often encounters a resident strain that it must either replace or co-exist with as a superinfection. Here, we use a Drosophila melanogaster cell culture system to study the dynamics of mixed Wolbachia infections consisting of the high-fidelity w Mel and promiscuous w Ri strains. The w Mel strain consistently outcompetes the w Ri strain, regardless of w Mel's initial frequency in D. melanogaster cells. This competitive advantage is independent of host species. While both strains significantly impede host cell division, only the w Mel strain is able to rapidly expand into uninfected cells. Our results suggest that the w Ri strain is pathogenic in nature and a poor cellular symbiont, and it is retained in natural infections because cell lineages are not expendable or replaceable in development. These findings provide insights into mixed infection outcomes, which are crucial for the use of the bacteria in biological control.}, }
@article {pmid38585906, year = {2024}, author = {Gasser, MT and Liu, A and Altamia, M and Brensinger, BR and Brewer, SL and Flatau, R and Hancock, ER and Preheim, SP and Filone, CM and Distel, DL}, title = {Outer membrane vesicles can contribute to cellulose degradation in Teredinibacter turnerae, a cultivable intracellular endosymbiont of shipworms.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.03.27.587001}, pmid = {38585906}, abstract = {Teredinibacter turnerae is a cultivable cellulolytic Gammaproeteobacterium (Cellvibrionaceae) that commonly occurs as an intracellular endosymbiont in the gills of wood-eating bivalves of the family Teredinidae (shipworms). The genome of T. turnerae encodes a broad range of enzymes that deconstruct cellulose, hemicellulose, and pectin and contribute to lignocellulose digestion in the shipworm gut. However, the mechanism by which symbiont-made enzymes are secreted by T. turnerae and subsequently transported to the site of lignocellulose digestion in the shipworm gut is incompletely understood. Here, we show that T. turnerae cultures grown on carboxymethyl cellulose (CMC) produce outer membrane vesicles (OMVs) that contain a variety of proteins identified by LC-MS/MS as carbohydrate-active enzymes with predicted activities against cellulose, hemicellulose, and pectin. Reducing sugar assays and zymography confirm that these OMVs retain cellulolytic activity, as evidenced by hydrolysis of CMC. Additionally, these OMVs were enriched with TonB -dependent receptors, which are essential to carbohydrate and iron acquisition by free-living bacteria. These observations suggest potential roles for OMVs in lignocellulose utilization by T. turnerae in the free-living state, in enzyme transport and host interaction during symbiotic association, and in commercial applications such as lignocellulosic biomass conversion.}, }
@article {pmid38577764, year = {2024}, author = {Garber, AI and Garcia de la Filia Molina, A and Vea, I and Mongue, AJ and Ross, L and McCutcheon, JP}, title = {Retention of an endosymbiont for the production of a single molecule.}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evae075}, pmid = {38577764}, issn = {1759-6653}, abstract = {Sap-feeding insects often maintain two or more nutritional endosymbionts which act in concert to produce compounds essential for insect survival. Many mealybugs have endosymbionts in a nested configuration: one or two bacterial species reside within the cytoplasm of another bacterium, and together these bacteria have genomes which encode interdependent sets of genes needed to produce key nutritional molecules. Here we show that the mealybug Pseudococcus viburni has three endosymbionts, one of which contributes only two unique genes that produce the host nutrition-related molecule chorismate. All three bacterial endosymbionts have tiny genomes, suggesting that they have been co-evolving inside their insect host for millions of years.}, }
@article {pmid38569988, year = {2024}, author = {Amala, M and Nagarajan, H and Ahila, M and Nachiappan, M and Veerapandiyan, M and Vetrivel, U and Jeyakanthan, J}, title = {Unveiling the intricacies of allosteric regulation in aspartate kinase from the Wolbachia endosymbiont of Brugia Malayi: Mechanistic and therapeutic insights.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {131326}, doi = {10.1016/j.ijbiomac.2024.131326}, pmid = {38569988}, issn = {1879-0003}, abstract = {Aspartate kinase (AK), an enzyme from the Wolbachia endosymbiont of Brugia malayi (WBm), plays a pivotal role in the bacterial cell wall and amino acid biosynthesis, rendering it an attractive candidate for therapeutic intervention. Allosteric inhibition of aspartate kinase is a prevalent mode of regulation across microorganisms and plants, often modulated by end products such as lysine, threonine, methionine, or meso-diaminopimelate. The intricate and diverse nature of microbial allosteric regulation underscores the need for rigorous investigation. This study employs a combined experimental and computational approach to decipher the allosteric regulation of WBmAK. Molecular Dynamics (MD) simulations elucidate that ATP (cofactor) and ASP (substrate) binding induce a closed conformation, promoting enzymatic activity. In contrast, the binding of lysine (allosteric inhibitor) leads to enzyme inactivation and an open conformation. The enzymatic assay demonstrates the optimal activity of WBmAK at 28 °C and a pH of 8.0. Notably, the allosteric inhibition study highlights lysine as a more potent inhibitor compared to threonine. Importantly, this investigation sheds light on the allosteric mechanism governing WBmAK and imparts novel insights into structure-based drug discovery, paving the way for the development of effective inhibitors against filarial pathogens.}, }
@article {pmid38465385, year = {2024}, author = {Park, E and Leander, B}, title = {Coinfection of slime feather duster worms (Annelida, Myxicola) by different gregarine apicomplexans (Selenidium) and astome ciliates reflects spatial niche partitioning and host specificity.}, journal = {Parasitology}, volume = {}, number = {}, pages = {1-12}, doi = {10.1017/S0031182024000209}, pmid = {38465385}, issn = {1469-8161}, support = {//Tula Foundation/ ; 2019-03986//Natural Sciences and Engineering Research Council of Canada/ ; }, abstract = {Individual organisms can host multiple species of parasites (or symbionts), and one species of parasite can infect different host species, creating complex interactions among multiple hosts and parasites. When multiple parasite species coexist in a host, they may compete or use strategies, such as spatial niche partitioning, to reduce competition. Here, we present a host–symbiont system with two species of Selenidium (Apicomplexa, Gregarinida) and one species of astome ciliate co-infecting two different species of slime feather duster worms (Annelida, Sabellidae, Myxicola) living in neighbouring habitats. We examined the morphology of the endosymbionts with light and scanning electron microscopy (SEM) and inferred their phylogenetic interrelationships using small subunit (SSU) rDNA sequences. In the host ‘Myxicola sp. Quadra’, we found two distinct species of Selenidium; S. cf. mesnili exclusively inhabited the foregut, and S. elongatum n. sp. inhabited the mid to hindgut, reflecting spatial niche partitioning. Selenidium elongatum n. sp. was also present in the host M. aesthetica, which harboured the astome ciliate Pennarella elegantia n. gen. et sp. Selenidium cf. mesnili and P. elegantia n. gen. et sp. were absent in the other host species, indicating host specificity. This system offers an intriguing opportunity to explore diverse aspects of host–endosymbiont interactions and competition among endosymbionts.}, }
@article {pmid38564675, year = {2024}, author = {Lehman, SS and Verhoeve, VI and Driscoll, TP and Beckmann, JF and Gillespie, JJ}, title = {Metagenome diversity illuminates the origins of pathogen effectors.}, journal = {mBio}, volume = {}, number = {}, pages = {e0075923}, doi = {10.1128/mbio.00759-23}, pmid = {38564675}, issn = {2150-7511}, abstract = {Recent metagenome-assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. The discovery of basal lineages (novel families Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles exposed an evolutionary timepoint for the transition to host dependency, which seemingly occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for later-evolving rickettsial pathogens. MAG analysis also substantially increased diversity for the genus Rickettsia and delineated a sister lineage (the novel genus Tisiphia) that stands to inform on the emergence of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages illuminates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, indicating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role in shaping the rvh effector landscape, as evinced by the discovery of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can yield insight into pathogen effector origins, particularly how effector architectures might become tailored to the discrete host cell functions of different eukaryotic hosts.IMPORTANCEWhile rickettsioses are deadly vector-borne human diseases, factors distinguishing Rickettsia pathogens from the innumerable bevy of environmental rickettsial endosymbionts remain lacking. Recent metagenome-assembled genome (MAG) studies revealed evolutionary timepoints for rickettsial transitions to host dependency. The rvh type IV secretion system was likely repurposed from congener killing in basal extracellular species to parasitizing host cells in later-evolving pathogens. Our analysis of MAG diversity for over two dozen rvh effectors unearthed their presence in some non-pathogens. However, most effectors were found in multiple divergent forms with variable architectures, indicating gene duplication and recombination-fashioned effector repertoires of Rickettsia pathogens. Lateral gene transfer substantially shaped pathogen effector arsenals, evinced by the discovery of effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchanges between Rickettsia and Legionella species. Our study exemplifies how MAGs yield insight into pathogen effector origins and evolutionary processes tailoring effectors to eukaryotic host cell biology.}, }
@article {pmid38558489, year = {2024}, author = {Ferguson, LF and Ross, PA and van Heerwaarden, B}, title = {Wolbachia infection negatively impacts Drosophila simulans heat tolerance in a strain- and trait-specific manner.}, journal = {Environmental microbiology}, volume = {26}, number = {4}, pages = {e16609}, doi = {10.1111/1462-2920.16609}, pmid = {38558489}, issn = {1462-2920}, support = {DE230100067//Australian Research Council/ ; FT200100025//Australian Research Council/ ; }, abstract = {The susceptibility of insects to rising temperatures has largely been measured by their ability to survive thermal extremes. However, the capacity for maternally inherited endosymbionts to influence insect heat tolerance has been overlooked. Further, while some studies have addressed the impact of heat on traits like fertility, which can decline at temperatures below lethal thermal limits, none have considered the impact of endosymbionts. Here, we assess the impact of three Wolbachia strains (wRi, wAu and wNo) on the survival and fertility of Drosophila simulans exposed to heat stress during development or as adults. The effect of Wolbachia infection on heat tolerance was generally small and trait/strain specific. Only the wNo infection significantly reduced the survival of adult males after a heat shock. When exposed to fluctuating heat stress during development, the wRi and wAu strains reduced egg-to-adult survival but only the wNo infection reduced male fertility. Wolbachia densities of all three strains decreased under developmental heat stress, but reductions occurred at temperatures above those that reduced host fertility. These findings emphasize the necessity to account for endosymbionts and their effect on both survival and fertility when investigating insect responses to heat stress.}, }
@article {pmid38557755, year = {2024}, author = {Cho, A and Lax, G and Livingston, SJ and Masukagami, Y and Naumova, M and Millar, O and Husnik, F and Keeling, PJ}, title = {Genomic analyses of Symbiomonas scintillans show no evidence for endosymbiotic bacteria but does reveal the presence of giant viruses.}, journal = {PLoS genetics}, volume = {20}, number = {4}, pages = {e1011218}, doi = {10.1371/journal.pgen.1011218}, pmid = {38557755}, issn = {1553-7404}, abstract = {Symbiomonas scintillans Guillou et Chrétiennot-Dinet, 1999 is a tiny (1.4 μm) heterotrophic microbial eukaryote. The genus was named based on the presence of endosymbiotic bacteria in its endoplasmic reticulum, however, like most such endosymbionts neither the identity nor functional association with its host were known. We generated both amplification-free shotgun metagenomics and whole genome amplification sequencing data from S. scintillans strains RCC257 and RCC24, but were unable to detect any sequences from known lineages of endosymbiotic bacteria. The absence of endobacteria was further verified with FISH analyses. Instead, numerous contigs in assemblies from both RCC24 and RCC257 were closely related to prasinoviruses infecting the green algae Ostreococcus lucimarinus, Bathycoccus prasinos, and Micromonas pusilla (OlV, BpV, and MpV, respectively). Using the BpV genome as a reference, we assembled a near-complete 190 kbp draft genome encoding all hallmark prasinovirus genes, as well as two additional incomplete assemblies of closely related but distinct viruses from RCC247, and three similar draft viral genomes from RCC24, which we collectively call SsVs. A multi-gene tree showed the three SsV genome types branched within highly supported clades with each of BpV2, OlVs, and MpVs, respectively. Interestingly, transmission electron microscopy also revealed a 190 nm virus-like particle similar the morphology and size of the endosymbiont originally reported in S. scintillans. Overall, we conclude that S. scintillans currently does not harbour an endosymbiotic bacterium, but is associated with giant viruses.}, }
@article {pmid38553514, year = {2024}, author = {Konecka, E and Szymkowiak, P}, title = {Wolbachia supergroup A in Enoplognatha latimana (Araneae: Theridiidae) in Poland as an example of possible horizontal transfer of bacteria.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {7486}, pmid = {38553514}, issn = {2045-2322}, mesh = {Animals ; Bacterial Proteins/genetics ; *Wolbachia/genetics ; RNA, Ribosomal, 16S/genetics ; Poland ; *Spiders/genetics ; Phylogeny ; }, abstract = {Wolbachia (phylum Pseudomonadota, class Alfaproteobacteria, order Rickettsiales, family Ehrlichiaceae) is a maternally inherited bacterial symbiont infecting more than half of arthropod species worldwide and constituting an important force in the evolution, biology, and ecology of invertebrate hosts. Our study contributes to the limited knowledge regarding the presence of intracellular symbiotic bacteria in spiders. Specifically, we investigated the occurrence of Wolbachia infection in the spider species Enoplognatha latimana Hippa and Oksala, 1982 (Araneae: Theridiidae) using a sample collected in north-western Poland. To the best of our knowledge, this is the first report of Wolbachia infection in E. latimana. A phylogeny based on the sequence analysis of multiple genes, including 16S rRNA, coxA, fbpA, ftsZ, gatB, gltA, groEL, hcpA, and wsp revealed that Wolbachia from the spider represented supergroup A and was related to bacterial endosymbionts discovered in other spider hosts, as well as insects of the orders Diptera and Hymenoptera. A sequence unique for Wolbachia supergroup A was detected for the ftsZ gene. The sequences of Wolbachia housekeeping genes have been deposited in publicly available databases and are an important source of molecular data for comparative studies. The etiology of Wolbachia infection in E. latimana is discussed.}, }
@article {pmid38535401, year = {2024}, author = {Cholvi, M and Trelis, M and Bueno-Marí, R and Khoubbane, M and Gil, R and Marcilla, A and Moretti, R}, title = {Wolbachia Infection through Hybridization to Enhance an Incompatible Insect Technique-Based Suppression of Aedes albopictus in Eastern Spain.}, journal = {Insects}, volume = {15}, number = {3}, pages = {}, pmid = {38535401}, issn = {2075-4450}, abstract = {The emergence of insecticide resistance in arbovirus vectors is putting the focus on the development of new strategies for control. In this regard, the exploitation of Wolbachia endosymbionts is receiving increasing attention due to its demonstrated effectiveness in reducing the vectorial capacity of Aedes mosquitoes. Here, we describe the establishment of a naïve Wolbachia infection in a wild Aedes albopictus population of eastern Spain through a hybridization approach to obtain males capable of sterilizing wild females. The obtained lines were compared with the Wolbachia donor, Ae. albopictus ARwP, previously artificially infected with Wolbachia wPip, regarding immature and adult survival, female fecundity, egg fertility, and level of induced sterility. Our results did not show significant differences between lines in any of the biological parameters analyzed, indicating the full suitability of the hybrids to be used as a control tool against Ae. albopictus. In particular, hybrid males induced 99.9% sterility in the eggs of wild females without the need for any preliminary treatment. Being harmless to non-target organisms and the environment, the use of this bacterium for the control of Ae. albopictus deserves further exploration. This is especially relevant in areas such as eastern Spain, where this mosquito species has recently spread and may represent a serious threat due to its competence as a vector for dengue, chikungunya, and Zika viruses.}, }
@article {pmid38534421, year = {2024}, author = {Hyder, M and Lodhi, AM and Wang, Z and Bukero, A and Gao, J and Mao, R}, title = {Wolbachia Interactions with Diverse Insect Hosts: From Reproductive Modulations to Sustainable Pest Management Strategies.}, journal = {Biology}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/biology13030151}, pmid = {38534421}, issn = {2079-7737}, support = {32202276//National Science Foundation of China/ ; 2022GDASZH-2022010106, 2022GDASZH-2022030501-08//GDAS Special Project of Science and Technology Development/ ; KTP20210352//Guangdong Province Rural Science and Technology Commissioner Project/ ; 2023SDZG06//Top Ten Critical Priorities of Agricultural Science and Technology Innovation for the 14th Five-Year Plan of Guangdong Province/ ; }, abstract = {Effective in a variety of insect orders, including dipteran, lepidopteran, and hemipteran, Wolbachia-based control tactics are investigated, noting the importance of sterile and incompatible insect techniques. Encouraging approaches for controlling Aedes mosquitoes are necessary, as demonstrated by the evaluation of a new SIT/IIT combination and the incorporation of SIT into Drosophila suzukii management. For example, Wolbachia may protect plants from rice pests, demonstrating its potential for agricultural biological vector management. Maternal transmission and cytoplasmic incompatibility dynamics are explored, while Wolbachia phenotypic impacts on mosquito and rice pest management are examined. The importance of host evolutionary distance is emphasised in recent scale insect research that addresses host-shifting. Using greater information, a suggested method for comprehending Wolbachia host variations in various contexts emphasises ecological connectivity. Endosymbionts passed on maternally in nematodes and arthropods, Wolbachia are widely distributed around the world and have evolved both mutualistic and parasitic traits. Wolbachia is positioned as a paradigm for microbial symbiosis due to advancements in multiomics, gene functional assays, and its effect on human health. The challenges and opportunities facing Wolbachia research include scale issues, ecological implications, ethical conundrums, and the possibility of customising strains through genetic engineering. It is thought that cooperative efforts are required to include Wolbachia-based therapies into pest management techniques while ensuring responsible and sustainable ways.}, }
@article {pmid38532645, year = {2024}, author = {Berrabah, F and Benaceur, F and Yin, C and Xin, D and Magne, K and Garmier, M and Gruber, V and Ratet, P}, title = {Defense and senescence interplay in legume nodules.}, journal = {Plant communications}, volume = {}, number = {}, pages = {100888}, doi = {10.1016/j.xplc.2024.100888}, pmid = {38532645}, issn = {2590-3462}, abstract = {Immunity and senescence play a crucial role in the functioning of the legume symbiotic nodules. The miss-regulation of one of these processes compromises the symbiosis leading to death of the endosymbiont and the arrest of the nodule functioning. The relationship between immunity and senescence is highly studied in plant organs where a synergistic response can be observed. However, the interplay between immunity and senescence in the symbiotic organ is poorly discussed in the literature and these phenomena are often mixed up. Recent studies revealed that the cooperation between immunity and senescence is not always observed in the nodule, suggesting complex interactions between these two processes within the symbiotic organ. Here, we discussed recent results on the interplay between immunity and senescence in the nodule and the specificities of this relationship during legume-rhizobium symbiosis.}, }
@article {pmid38525276, year = {2024}, author = {Guse, K and Pietri, JE}, title = {Endosymbiont and gut bacterial communities of the brown-banded cockroach, Supella longipalpa.}, journal = {PeerJ}, volume = {12}, number = {}, pages = {e17095}, pmid = {38525276}, issn = {2167-8359}, mesh = {Male ; Animals ; Female ; Adult ; Humans ; *Blattellidae/genetics ; *Gastrointestinal Microbiome ; RNA, Ribosomal, 16S/genetics ; *Flavobacteriaceae/genetics ; Symbiosis/genetics ; }, abstract = {The brown-banded cockroach (Supella longipalpa) is a widespread nuisance and public health pest. Like the German cockroach (Blattella germanica), this species is adapted to the indoor biome and completes the entirety of its life cycle in human-built structures. Recently, understanding the contributions of commensal and symbiotic microbes to the biology of cockroach pests, as well as the applications of targeting these microbes for pest control, have garnered significant scientific interest. However, relative to B. germanica, the biology of S. longipalpa, including its microbial associations, is understudied. Therefore, the goal of the present study was to quantitatively examine and characterize both the endosymbiont and gut bacterial communities of S. longipalpa for the first time. To do so, bacterial 16S rRNA gene amplicon sequencing was conducted on DNA extracts from whole adult females and males, early instar nymphs, and late instar nymphs. The results demonstrate that the gut microbiome is dominated by two genera of bacteria known to have beneficial probiotic effects in other organisms, namely Lactobacillus and Akkermansia. Furthermore, our data show a significant effect of nymphal development on diversity and variation in the gut microbiome. Lastly, we reveal significant negative correlations between the two intracellular endosymbionts, Blattabacterium and Wolbachia, as well as between Blattabacterium and the gut microbiome, suggesting that Blattabacterium endosymbionts could directly or indirectly influence the composition of other bacterial populations. These findings have implications for understanding the adaptation of S. longipalpa to the indoor biome, its divergence from other indoor cockroach pest species such as B. germanica, the development of novel control approaches that target the microbiome, and fundamental insect-microbe interactions more broadly.}, }
@article {pmid38519099, year = {2024}, author = {Bai, J and Zuo, Z and DuanMu, H and Li, M and Tong, H and Mei, Y and Xiao, Y and He, K and Jiang, M and Wang, S and Li, F}, title = {Endosymbiont Tremblaya phenacola influences the reproduction of cotton mealybugs by regulating the mTOR pathway.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, doi = {10.1093/ismejo/wrae052}, pmid = {38519099}, issn = {1751-7370}, abstract = {The intricate evolutionary dynamics of endosymbiotic relationships result in unique characteristics among the genomes of symbionts, which profoundly influence host insect phenotypes. Here, we investigated an endosymbiotic system in Phenacoccus solenopsis, a notorious pest of the subfamily Phenacoccinae. The endosymbiont, "Candidatus Tremblaya phenacola" (T. phenacola PSOL), persisted throughout the complete life cycle of female hosts and was more active during oviposition, whereas there was a significant decline in abundance after pupation in males. Genome sequencing yielded an endosymbiont genome of 221.1 kb in size, comprising seven contigs and originating from a chimeric arrangement between betaproteobacteria and gammaproteobacteria. A comprehensive analysis of amino acid metabolic pathways demonstrated complementarity between the host and endosymbiont metabolism. Elimination of T. phenacola PSOL through antibiotic treatment significantly decreased P. solenopsis fecundity. Weighted gene co-expression network analysis (WGCNA) demonstrated a correlation between genes associated with essential amino acid synthesis and those associated with host meiosis and oocyte maturation. Moreover, altering endosymbiont abundance activated the host mTOR pathway, suggesting that changes in amino acid abundance affected host reproductive capabilities via this signal pathway. Taken together, these findings demonstrate a mechanism by which the endosymbiont T. phenacola PSOL contributed to high fecundity in P. solenopsis and provide new insights into nutritional compensation and coevolution of the endosymbiotic system.}, }
@article {pmid38509052, year = {2024}, author = {Ang'ang'o, LM and Waweru, JW and Makhulu, EE and Wairimu, A and Otieno, FG and Onchuru, T and Tastan Bishop, &#xd6; and Herren, JK}, title = {Draft genome of Microsporidia sp. MB-a malaria-blocking microsporidian symbiont of the Anopheles arabiensis.}, journal = {Microbiology resource announcements}, volume = {}, number = {}, pages = {e0090323}, doi = {10.1128/MRA.00903-23}, pmid = {38509052}, issn = {2576-098X}, abstract = {We report the draft whole-genome assembly of Microsporidia sp. MB, a symbiotic malaria-transmission-blocking microsporidian isolated from Anopheles arabiensis in Kenya. The whole-genome sequence of Microsporidia sp. MB has a length of 5,908,979 bp, 2,335 contigs, and an average GC content of 31.12%.}, }
@article {pmid38505947, year = {2024}, author = {Torp, MK and Stensløkken, KO and Vaage, J}, title = {When Our Best Friend Becomes Our Worst Enemy: The Mitochondrion in Trauma, Surgery, and Critical Illness.}, journal = {Journal of intensive care medicine}, volume = {}, number = {}, pages = {8850666241237715}, doi = {10.1177/08850666241237715}, pmid = {38505947}, issn = {1525-1489}, abstract = {Common for major surgery, multitrauma, sepsis, and critical illness, is a whole-body inflammation. Tissue injury is able to trigger a generalized inflammatory reaction. Cell death causes release of endogenous structures termed damage associated molecular patterns (DAMPs) that initiate a sterile inflammation. Mitochondria are evolutionary endosymbionts originating from bacteria, containing molecular patterns similar to bacteria. These molecular patterns are termed mitochondrial DAMPs (mDAMPs). Mitochondrial debris released into the extracellular space or into the circulation is immunogenic and damaging secondary to activation of the innate immune system. In the circulation, released mDAMPS are either free or exist in extracellular vesicles, being able to act on every organ and cell in the body. However, the role of mDAMPs in trauma and critical care is not fully clarified. There is a complete lack of knowledge how they may be counteracted in patients. Among mDAMPs are mitochondrial DNA, cardiolipin, N-formyl peptides, cytochrome C, adenosine triphosphate, reactive oxygen species, succinate, and mitochondrial transcription factor A. In this overview, we present the different mDAMPs, their function, release, targets, and inflammatory potential. In light of present knowledge, the role of mDAMPs in the pathophysiology of major surgery and trauma as well as sepsis, and critical care is discussed.}, }
@article {pmid38502496, year = {2024}, author = {Füssy, Z and Oborník, M}, title = {Complex Endosymbioses I: From Primary to Complex Plastids, Serial Endosymbiotic Events.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2776}, number = {}, pages = {21-41}, pmid = {38502496}, issn = {1940-6029}, abstract = {A considerable part of the diversity of eukaryotic phototrophs consists of algae with plastids that evolved from endosymbioses between two eukaryotes. These complex plastids are characterized by a high number of envelope membranes (more than two) and some of them contain a residual nucleus of the endosymbiotic alga called a nucleomorph. Complex plastid-bearing algae are thus chimeric cell assemblies, eukaryotic symbionts living in a eukaryotic host. In contrast, the primary plastids of the Archaeplastida (plants, green algae, red algae, and glaucophytes) possibly evolved from a single endosymbiosis with a cyanobacterium and are surrounded by two membranes. Complex plastids have been acquired several times by unrelated groups of eukaryotic heterotrophic hosts, suggesting that complex plastids are somewhat easier to obtain than primary plastids. Evidence suggests that complex plastids arose twice independently in the green lineage (euglenophytes and chlorarachniophytes) through secondary endosymbiosis, and four times in the red lineage, first through secondary endosymbiosis in cryptophytes, then by higher-order events in stramenopiles, alveolates, and haptophytes. Engulfment of primary and complex plastid-containing algae by eukaryotic hosts (secondary, tertiary, and higher-order endosymbioses) is also responsible for numerous plastid replacements in dinoflagellates. Plastid endosymbiosis is accompanied by massive gene transfer from the endosymbiont to the host nucleus and cell adaptation of both endosymbiotic partners, which is related to the trophic switch to phototrophy and loss of autonomy of the endosymbiont. Such a process is essential for the metabolic integration and division control of the endosymbiont in the host. Although photosynthesis is the main advantage of acquiring plastids, loss of photosynthesis often occurs in algae with complex plastids. This chapter summarizes the essential knowledge of the acquisition, evolution, and function of complex plastids.}, }
@article {pmid38502456, year = {2024}, author = {Singh, AS and Pathak, D and Devi, MS and Anifowoshe, AT and Nongthomba, U}, title = {Antibiotic alters host's gut microbiota, fertility, and antimicrobial peptide gene expression vis-à-vis ampicillin treatment on model organism Drosophila melanogaster.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {38502456}, issn = {1618-1905}, support = {DBT-RA/2022/January NE/994//Department of Biotechnology, Government of India./ ; DBT-RA/2022/January NE/994//Department of Biotechnology, Government of India./ ; }, abstract = {Antibiotics are commonly used to treat infectious diseases; however, persistence is often expressed by the pathogenic bacteria and their long-term relative effect on the host have been neglected. The present study investigated the impact of antibiotics in gut microbiota (GM) and metabolism of host. The effect of ampicillin antibiotics on GM of Drosophila melanogaster was analyzed through deep sequencing of 16S rRNA amplicon gene. The dominant phyla consisted of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Planctomycetes, Chloroflexi, Euryarchaeota, Acedobacteria, Verrucomicrobia, and Cyanobacteria. It was found that the composition of GM was significantly altered on administration of antibiotics. On antibiotic treatments, there were decline in relative abundance of Proteobacteria and Firmicutes, while there were increase in relative abundance of Chlorophyta and Bacteroidota. High abundance of 14 genera, viz., Wolbachia, Lactobacillus, Bacillus, Pseudomonas, Thiolamprovum, Pseudoalteromonas, Vibrio, Romboutsia, Staphylococcus, Alteromonas, Clostridium, Lysinibacillus, Litoricola, and Cellulophaga were significant (p ≤ 0.05) upon antibiotic treatment. Particularly, the abundance of Acetobacter was significantly (p ≤ 0.05) declined but increased for Wolbachia. Further, a significant (p ≤ 0.05) increase in Wolbachia endosymbiont of D. melanogaster, Wolbachia endosymbiont of Curculio okumai, and Wolbachia pipientis and a decrease in the Acinetobacter sp. were observed. We observed an increase in functional capacity for biosynthesis of certain nucleotides and the enzyme activities. Further, the decrease in antimicrobial peptide production in the treated group and potential effects on the host's defense mechanisms were observed. This study helps shed light on an often-overlooked dimension, namely the persistence of antibiotics' effects on the host.}, }
@article {pmid38499810, year = {2024}, author = {Novák Vanclová, AM and Nef, C and Füssy, Z and Vancl, A and Liu, F and Bowler, C and Dorrell, RG}, title = {New plastids, old proteins: repeated endosymbiotic acquisitions in kareniacean dinoflagellates.}, journal = {EMBO reports}, volume = {}, number = {}, pages = {}, pmid = {38499810}, issn = {1469-3178}, support = {ANR-21-CE02-0014//Agence Nationale de la Recherche (ANR)/ ; ANR-20-CE13-0007//Agence Nationale de la Recherche (ANR)/ ; ANR-19-CE20-0020//Agence Nationale de la Recherche (ANR)/ ; 101039760//EC | European Research Council (ERC)/ ; 835067//EC | European Research Council (ERC)/ ; Momentum Fellowship 2019-2021//Centre National de la Recherche Scientifique (CNRS)/ ; 835067//EC | ERC | HORIZON EUROPE European Research Council (ERC)/ ; ANR-10-LABX-54//Agence Nationale de la Recherche (ANR)/ ; ANR-1253 11-IDEX-0001-02//Universit&#xe9; de Recherche Paris Sciences et Lettres (PSL)/ ; 90254//e-INFRA CZ/ ; }, abstract = {Dinoflagellates are a diverse group of ecologically significant micro-eukaryotes that can serve as a model system for plastid symbiogenesis due to their susceptibility to plastid loss and replacement via serial endosymbiosis. Kareniaceae harbor fucoxanthin-pigmented plastids instead of the ancestral peridinin-pigmented ones and support them with a diverse range of nucleus-encoded plastid-targeted proteins originating from the haptophyte endosymbiont, dinoflagellate host, and/or lateral gene transfers (LGT). Here, we present predicted plastid proteomes from seven distantly related kareniaceans in three genera (Karenia, Karlodinium, and Takayama) and analyze their evolutionary patterns using automated tree building and sorting. We project a relatively limited (~ 10%) haptophyte signal pointing towards a shared origin in the family Chrysochromulinaceae. Our data establish significant variations in the functional distributions of these signals, emphasizing the importance of micro-evolutionary processes in shaping the chimeric proteomes. Analysis of plastid genome sequences recontextualizes these results by a striking finding the extant kareniacean plastids are in fact not all of the same origin, as two of the studied species (Karlodinium armiger, Takayama helix) possess plastids from different haptophyte orders than the rest.}, }
@article {pmid38497713, year = {2024}, author = {Tang, X-F and Sun, Y-F and Liang, Y-S and Yang, K-Y and Chen, P-T and Li, H-S and Huang, Y-H and Pang, H}, title = {Metabolism, digestion, and horizontal transfer: potential roles and interaction of symbiotic bacteria in the ladybird beetle Novius pumilus and their prey Icerya aegyptiaca.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0295523}, doi = {10.1128/spectrum.02955-23}, pmid = {38497713}, issn = {2165-0497}, abstract = {In this study, we first time sequenced and analyzed the 16S rRNA gene data of predator ladybird beetles Novius pumilus and globally distributed invasive pest Icerya aegyptiaca at different stages, and combined data with bacterial genome sequences in N. pumilus to explored the taxonomic distribution, alpha and beta diversity, differentially abundant bacteria, co-occurrence network, and putative functions of their microbial community. Our finding revealed that Candidatus Walczuchella, which exhibited a higher abundance in I. aegyptiaca, possessed several genes in essential amino acid biosynthesis and seemed to perform roles in providing nutrients to the host, similar to other obligate symbionts in scale insects. Lactococcus, Serratia, and Pseudomonas, more abundant in N. pumilus, were predicted to have genes related to hydrocarbon, fatty acids, and chitin degradation, which may assist their hosts in digesting the wax shell covering the scale insects. Notably, our result showed that Lactococcus had relatively higher abundances in adults and eggs compared to other stages in N. pumilus, indicating potential vertical transmission. Additionally, we found that Arsenophonus, known to influence sex ratios in whitefly and wasp, may also function in I. aegyptiaca, probably by influencing nutrient metabolism as it similarly had many genes corresponding to vitamin B and essential amino acid biosynthesis. Also, we observed a potential horizontal transfer of Arsenophonus between the scale insect and its predator, with a relatively high abundance in the ladybirds compared to other bacteria from the scale insects.IMPORTANCEThe composition and dynamic changes of microbiome in different developmental stages of ladybird beetles Novius pumilus with its prey Icerya aegyptiaca were detected. We found that Candidatus Walczuchella, abundant in I. aegyptiaca, probably provide nutrients to their host based on their amino acid biosynthesis-related genes. Abundant symbionts in N. pumilus, including Lactococcus, Serratia, and Pseudophonus, may help the host digest the scale insects with their hydrocarbon, fatty acid, and chitin degrading-related genes. A key endosymbiont Arsenophonus may play potential roles in the nutrient metabolisms and sex determination in I. aegyptiaca, and is possibly transferred from the scale insect to the predator.}, }
@article {pmid38497254, year = {2024}, author = {Galambos, N and Vincent-Monegat, C and Vallier, A and Parisot, N and Heddi, A and Zaidman-Rémy, A}, title = {Cereal weevils' antimicrobial peptides: at the crosstalk between development, endosymbiosis and immune response.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {379}, number = {1901}, pages = {20230062}, doi = {10.1098/rstb.2023.0062}, pmid = {38497254}, issn = {1471-2970}, abstract = {Interactions between animals and microbes are ubiquitous in nature and strongly impact animal physiology. These interactions are shaped by the host immune system, which responds to infections and contributes to tailor the associations with beneficial microorganisms. In many insects, beneficial symbiotic associations not only include gut commensals, but also intracellular bacteria, or endosymbionts. Endosymbionts are housed within specialized host cells, the bacteriocytes, and are transmitted vertically across host generations. Host-endosymbiont co-evolution shapes the endosymbiont genome and host immune system, which not only fights against microbial intruders, but also ensures the preservation of endosymbionts and the control of their load and location. The cereal weevil Sitophilus spp. is a remarkable model in which to study the evolutionary adaptation of the immune system to endosymbiosis owing to its binary association with a unique, relatively recently acquired nutritional endosymbiont, Sodalis pierantonius. This Gram-negative bacterium has not experienced the genome size shrinkage observed in long-term endosymbioses and has retained immunogenicity. We focus here on the sixteen antimicrobial peptides (AMPs) identified in the Sitophilus oryzae genome and their expression patterns in different tissues, along host development or upon immune challenges, to address their potential functions in the defensive response and endosymbiosis homeostasis along the insect life cycle. This article is part of the theme issue 'Sculpting the microbiome: how host factors determine and respond to microbial colonization'.}, }
@article {pmid38496649, year = {2024}, author = {Hague, MTJ and Wheeler, TB and Cooper, BS}, title = {Comparative analysis of Wolbachia maternal transmission and localization in host ovaries.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2024.03.03.583170}, pmid = {38496649}, abstract = {Many insects and other animals carry microbial endosymbionts that influence their reproduction and fitness. These relationships only persist if endosymbionts are reliably transmitted from one host generation to the next. Wolbachia are maternally transmitted endosymbionts found in most insect species, but transmission rates can vary across environments. Maternal transmission of w Mel Wolbachia depends on temperature in natural Drosophila melanogaster hosts and in transinfected Aedes aegypti , where w Mel is used to block pathogens that cause human disease. In D. melanogaster , w Mel transmission declines in the cold as Wolbachia become less abundant in host ovaries and at the posterior pole plasm (the site of germline formation) in mature oocytes. Here, we assess how temperature affects maternal transmission and underlying patterns of Wolbachia localization across 10 Wolbachia strains diverged up to 50 million years-including strains closely related to w Mel-and their natural Drosophila hosts. Many Wolbachia maintain high transmission rates across temperatures, despite highly variable (and sometimes low) levels of Wolbachia in the ovaries and at the developing germline in late-stage oocytes. Identifying strains like closely related w Mel-like Wolbachia with stable transmission across variable environmental conditions may improve the efficacy of Wolbachia -based biocontrol efforts as they expand into globally diverse environments.}, }
@article {pmid38493166, year = {2024}, author = {Zhao, LS and Wang, N and Li, K and Li, CY and Guo, JP and He, FY and Liu, GM and Chen, XL and Gao, J and Liu, LN and Zhang, YZ}, title = {Architecture of symbiotic dinoflagellate photosystem I-light-harvesting supercomplex in Symbiodinium.}, journal = {Nature communications}, volume = {15}, number = {1}, pages = {2392}, pmid = {38493166}, issn = {2041-1723}, support = {BB/V009729/1//RCUK | Biotechnology and Biological Sciences Research Council (BBSRC)/ ; BB/R003890/1//RCUK | Biotechnology and Biological Sciences Research Council (BBSRC)/ ; URF\R\180030//Royal Society/ ; }, mesh = {*Photosystem I Protein Complex/metabolism ; *Light-Harvesting Protein Complexes/metabolism ; Ecosystem ; Cryoelectron Microscopy ; Photosynthesis ; }, abstract = {Symbiodinium are the photosynthetic endosymbionts for corals and play a vital role in supplying their coral hosts with photosynthetic products, forming the nutritional foundation for high-yield coral reef ecosystems. Here, we determine the cryo-electron microscopy structure of Symbiodinium photosystem I (PSI) supercomplex with a PSI core composed of 13 subunits including 2 previously unidentified subunits, PsaT and PsaU, as well as 13 peridinin-Chl a/c-binding light-harvesting antenna proteins (AcpPCIs). The PSI-AcpPCI supercomplex exhibits distinctive structural features compared to their red lineage counterparts, including extended termini of PsaD/E/I/J/L/M/R and AcpPCI-1/3/5/7/8/11 subunits, conformational changes in the surface loops of PsaA and PsaB subunits, facilitating the association between the PSI core and peripheral antennae. Structural analysis and computational calculation of excitation energy transfer rates unravel specific pigment networks in Symbiodinium PSI-AcpPCI for efficient excitation energy transfer. Overall, this study provides a structural basis for deciphering the mechanisms governing light harvesting and energy transfer in Symbiodinium PSI-AcpPCI supercomplexes adapted to their symbiotic ecosystem, as well as insights into the evolutionary diversity of PSI-LHCI among various photosynthetic organisms.}, }
@article {pmid38487180, year = {2024}, author = {Duan, L and Zhang, L and Hou, X and Bao, Z and Zeng, Y and He, L and Liu, Z and Zhou, H and Hao, Q and Dong, A}, title = {Surveillance of tick-borne bacteria infection in ticks and forestry populations in Inner Mongolia, China.}, journal = {Frontiers in public health}, volume = {12}, number = {}, pages = {1302133}, pmid = {38487180}, issn = {2296-2565}, abstract = {Ticks are one of the most important vectors that can transmit pathogens to animals and human beings. This study investigated the dominant tick-borne bacteria carried by ticks and tick-borne infections in forestry populations in Arxan, Inner Mongolia, China. Ticks were collected by flagging from May 2020 to May 2021, and blood samples were collected from individuals at high risk of acquiring tick-borne diseases from March 2022 to August 2023. The pooled DNA samples of ticks were analyzed to reveal the presence of tick-borne bacteria using high-throughput sequencing of the 16S rDNA V3-V4 region, and species-specific polymerase chain reaction (PCR) related to sequencing was performed to confirm the presence of pathogenic bacteria in individual ticks and human blood samples. All sera samples were examined for anti-SFGR using ELISA and anti-B. burgdorferi using IFA and WB. A total of 295 ticks (282 Ixodes persulcatus and 13 Dermacentor silvarum) and 245 human blood samples were collected. Rickettsia, Anaplasma, Borrelia miyamotoi, and Coxiella endosymbiont were identified in I. persulcatus by high-throughput sequencing, while Candidatus R. tarasevichiae (89.00%, 89/100), B. garinii (17.00%, 17/100), B. afzelii (7.00%, 7/100), and B. miyamotoi (7.00%, 7/100) were detected in I. persulcatus, as well the dual co-infection with Candidatus R. tarasevichiae and B. garinii were detected in 13.00% (13/100) of I. persulcatus. Of the 245 individuals, B. garinii (4.90%, 12/245), R. slovaca (0.82%, 2/245), and C. burnetii (0.41%, 1/245) were detected by PCR, and the sequences of the target genes of B. garinii detected in humans were identical to those detected in I. persulcatus. The seroprevalence of anti-SFGR and anti-B. burgdorferi was 5.71% and 13.47%, respectively. This study demonstrated that Candidatus R. tarasevichiae and B. garinii were the dominant tick-borne bacteria in I. persulcatus from Arxan, and that dual co-infection with Candidatus R. tarasevichiae and B. garinii was frequent. This is the first time that B. miyamotoi has been identified in ticks from Arxan and R. solvaca has been detected in humans from Inner Mongolia. More importantly, this study demonstrated the transmission of B. garinii from ticks to humans in Arxan, suggesting that long-term monitoring of tick-borne pathogens in ticks and humans is important for the prevention and control of tick-borne diseases.}, }
@article {pmid38486702, year = {2024}, author = {Liu, XL and Zhao, H and Wang, YX and Liu, XY and Jiang, Y and Tao, MF and Liu, XY}, title = {Detecting and characterizing new endofungal bacteria in new hosts: Pandoraea sputorum and Mycetohabitans endofungorum in Rhizopus arrhizus.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1346252}, doi = {10.3389/fmicb.2024.1346252}, pmid = {38486702}, issn = {1664-302X}, abstract = {The fungus Rhizopus arrhizus (=R. oryzae) is commonly saprotrophic, exhibiting a nature of decomposing organic matter. Additionally, it serves as a crucial starter in food fermentation and can act as a pathogen causing mucormycosis in humans and animals. In this study, two distinct endofungal bacteria (EFBs), associated with individual strains of R. arrhizus, were identified using live/dead staining, fluorescence in situ hybridization, transmission electron microscopy, and 16S rDNA sequencing. The roles of these bacteria were elucidated through antibiotic treatment, pure cultivation, and comparative genomics. The bacterial endosymbionts, Pandoraea sputorum EFB03792 and Mycetohabitans endofungorum EFB03829, were purified from the host fungal strains R. arrhizus XY03792 and XY03829, respectively. Notably, this study marks the first report of Pandoraea as an EFB genus. Compared to its free-living counterparts, P. sputorum EFB03792 exhibited 28 specific virulence factor-related genes, six specific CE10 family genes, and 74 genes associated with type III secretion system (T3SS), emphasizing its pivotal role in invasion and colonization. Furthermore, this study introduces R. arrhizus as a new host for EFB M. endofungorum, with EFB contributing to host sporulation. Despite a visibly reduced genome, M. endofungorum EFB03829 displayed a substantial number of virulence factor-related genes, CE10 family genes, T3SS genes, mobile elements, and significant gene rearrangement. While EFBs have been previously identified in R. arrhizus, their toxin-producing potential in food fermentation has not been explored until this study. The discovery of these two new EFBs highlights their potential for toxin production within R. arrhizus, laying the groundwork for identifying suitable R. arrhizus strains for fermentation processes.}, }
@article {pmid38479454, year = {2024}, author = {Del Carmen Guarneros Martínez, T and Cáceres-Martínez, J and Cruz-Flores, R and López-Carvallo, JA and Ángel Del Río-Portilla, M and Guerrero Rentería, Y}, title = {Prevalence and intensity of a rickettsiales-like organism in cultured pleasure oyster, crassostrea corteziensis, from nayarit, mexico.}, journal = {Journal of invertebrate pathology}, volume = {204}, number = {}, pages = {108093}, doi = {10.1016/j.jip.2024.108093}, pmid = {38479454}, issn = {1096-0805}, abstract = {Fastidious endosymbiotic Rickettsiales-like organisms (RLOs) have been observed in the digestive diverticula of the cultured pleasure oyster (Crassostrea corteziensis) from Nayarit, Mexico since 2007. In a few mollusk species, these bacteria have been associated with mortality events and production losses. The type of relationship between the RLOs and the pleasure oyster is largely unknown and further investigations are needed to determine if these bacteria warrant management concern in C. corteziensis. In this study, the morphological characteristics of the RLOs were studied by histology and SEM, and the taxonomic affiliations of the bacteria were evaluated by 16S rRNA amplicon sequencing. In addition, the prevalence and intensity of the RLOs was recorded from 2007 to 2017 by histology. The RLOs were observed inside circular basophilic cytoplasmic membrane bound vacuoles (MBVs) that had an average length and width of 15.70 ± 15.24 µm and 15.42 ± 14.95 µm respectively. Apart from cellular hypertrophy, no tissue alterations were observed in the areas adjacent to the RLOs. Individual bacteria within the MBVs were coccoid in shape with an average length of 0.65 ± 0.12 µm and an average width of 0.38 ± 0.09 µm. The bacterial microbiota of a selected number of samples (one sample without RLOs and two samples with RLOs) showed the presence of intracellular parasite OTUs corresponding to the families Rickettsiaceae and Anaplasmataceae, suggesting that the RLOs from the pleasure oyster is associated with the order Rickettsiales. A mean prevalence of 5 % was observed throughout the study period and the majority of the organisms (89 %) presented low intensity of Grade 1 (30-61 RLOs) of the MBVs. A higher prevalence of the RLOs was observed during warmer months. The lack of tissue alterations, the low prevalence and the low intensity of the MBVs suggest that the RLOs from C. corteziensis is a commensal endosymbiont that presents little risk for oyster production in Nayarit, México. However, regular monitoring is needed to detect if any variation in this relationship occurs, mainly in a scenario where extreme environmental fluctuations may occur.}, }
@article {pmid38479324, year = {2024}, author = {Walters, LJ and Busch, SJ and Vermeulen, S and Craig, CA}, title = {Entanglement and ingestion of microfibers by the oyster pea crab Zaops ostreum, an endosymbiont of the eastern oyster Crassostrea virginica.}, journal = {Marine pollution bulletin}, volume = {201}, number = {}, pages = {116251}, doi = {10.1016/j.marpolbul.2024.116251}, pmid = {38479324}, issn = {1879-3363}, abstract = {The kleptoparasitic pea crab Zaops ostreum lives within the gills of bivalves, including the economically important eastern oyster Crassostrea virginica. Previous research along the east coast of central Florida has found an average of 2.3 pieces of plastic per oyster. The goals of our research were to determine if filter-feeding oysters transfer microfibers to Z. ostreum via the crab: 1) actively consuming plastic particles, or 2) passively becoming entangled in microfibers. Our results show that both occur. While only 11.6 % of Z. ostreum (total n = 122) consumed microfibers, those that did had up to 14 pieces in their soft tissues. Similarly, only 7.4 % of Z. ostreum had microfibers entangled around their appendages. Mean lengths of consumed and entangled fibers were similar, 1.9 and 2.7 mm, respectively. Additional research is needed to understand the positive and negative impacts of microfibers associated with pea crabs on both species.}, }
@article {pmid38472683, year = {2024}, author = {Ezhova, OV and Lukinykh, AI and Malakhov, VV}, title = {Nemertodermatida-Endosymbionts of Deep-Sea Acorn Worms (Hemichordata, Torquaratoridae).}, journal = {Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections}, volume = {}, number = {}, pages = {}, pmid = {38472683}, issn = {1608-3105}, abstract = {Worm-like endosymbionts were found in the hepatic region of the digestive tract of the deep-sea acorn worm Quatuoralisia malakhovi Ezhova et Lukinykh, 2022 (family Torquaratoridae) from the Bering Sea. The symbionts were assigned to the taxon Nemertodermatida on the basis of histological examination. Torquaratoridae are similar in feeding type to holothuroids, which have also been found to have Xenacoelomorpha endosymbionts.}, }
@article {pmid38471501, year = {2024}, author = {Cornejo-Castillo, FM and Inomura, K and Zehr, JP and Follows, MJ}, title = {Metabolic trade-offs constrain the cell size ratio in a nitrogen-fixing symbiosis.}, journal = {Cell}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cell.2024.02.016}, pmid = {38471501}, issn = {1097-4172}, abstract = {Biological dinitrogen (N2) fixation is a key metabolic process exclusively performed by prokaryotes, some of which are symbiotic with eukaryotes. Species of the marine haptophyte algae Braarudosphaera bigelowii harbor the N2-fixing endosymbiotic cyanobacteria UCYN-A, which might be evolving organelle-like characteristics. We found that the size ratio between UCYN-A and their hosts is strikingly conserved across sublineages/species, which is consistent with the size relationships of organelles in this symbiosis and other species. Metabolic modeling showed that this size relationship maximizes the coordinated growth rate based on trade-offs between resource acquisition and exchange. Our findings show that the size relationships of N2-fixing endosymbionts and organelles in unicellular eukaryotes are constrained by predictable metabolic underpinnings and that UCYN-A is, in many regards, functioning like a hypothetical N2-fixing organelle (or nitroplast).}, }
@article {pmid38469952, year = {2024}, author = {Arinanto, LS and Hoffmann, AA and Ross, PA and Gu, X}, title = {Hormetic effect induced by Beauveria bassiana in Myzus persicae.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.8075}, pmid = {38469952}, issn = {1526-4998}, abstract = {BACKGROUND: Myzus persicae, a serious sap-sucking pest of a large variety of host plants in agriculture, is traditionally controlled using chemical insecticides but there is interest in using biopesticides as restrictions are increasingly placed on the use of broad-spectrum pesticides.<br><br>RESULTS: Here we show that in petri dish experiments high concentrations of the fungal entomopathogen Beauveria bassiana lead to rapid mortality of M. persicae but at a low concentration (1&#x2009;&#xd7;&#x2009;10[4] conidia mL[-1]) there is a hormetic effect where survival and fecundity are enhanced. Hormetic effects persisted across a generation with reduced development times and increased fecundity in the offspring of M. persicae exposed to B. bassiana. Whole plant experiments point to a hormetic effect being detected in two out of three tested lines. The impact of these effects might also depend on whether M. persicae was transinfected with the endosymbiont Rickettsiella viridis, which decreases fecundity and survival compared to aphids lacking this endosymbiont. This fecundity cost was ameliorated in the generation following exposure to the entomopathogen.<br><br>CONCLUSION: While B. bassiana is effective in controlling M. persicae especially at higher spore concentrations, utilization of this entomopathogen requires careful consideration of hormetic effects at lower spore concentrations, and further research to optimize its application for sustainable agriculture is recommended. This article is protected by copyright. All rights reserved.}, }
@article {pmid38468292, year = {2024}, author = {Ahouandjinou, MJ and Sovi, A and Sidick, A and Sewadé, W and Koukpo, CZ and Chitou, S and Towakinou, L and Adjottin, B and Hougbe, S and Tokponnon, F and Padonou, GG and Akogbéto, M and Messenger, LA and Ossè, RA}, title = {First report of natural infection of Anopheles gambiae s.s. and Anopheles coluzzii by Wolbachia and Microsporidia in Benin: a cross-sectional study.}, journal = {Malaria journal}, volume = {23}, number = {1}, pages = {72}, pmid = {38468292}, issn = {1475-2875}, abstract = {BACKGROUND: Recently, bacterial endosymbiont, including Wolbachia and Microsporidia were found to limit the infection of Anopheles mosquitoes with Plasmodium falciparum. This study aimed to investigate the natural presence of key transmission-blocking endosymbionts in Anopheles gambiae and Anopheles coluzzii in Southern Benin.<br><br>METHODS: The present study was conducted in seven communes (Cotonou, Porto-Novo, Agu&#xe9;gu&#xe9;s, Ifangni, Pob&#xe8; Athi&#xe9;m&#xe9;, and Grand-Popo) of Southern Benin. Anopheles were collected using indoor/outdoor Human Landing Catches (HLCs) and Pyrethrum Spray Catches (PSCs). Following morphological identification, PCR was used to identify An. gambiae sensu lato (s.l.) to species level and to screen for the presence of both Wolbachia and Microsporidia. Plasmodium falciparum sporozoite infection was also assessed using ELISA.<br><br>RESULTS: Overall, species composition in An. gambiae s.l. was 53.7% An. coluzzii, while the remainder was An. gambiae sensu stricto (s.s.). Combined data of the two sampling techniques revealed a mean infection prevalence with Wolbachia of 5.1% (95% CI 0.90-18.6) and 1.3% (95% CI 0.07-7.8) in An. gambiae s.s. and An. coluzzii, respectively. The mean infection prevalence with Microsporidia was 41.0% (95% CI 25.9-57.8) for An. gambiae s.s. and 57.0% (95% CI 45.4-67.9) for An. coluzzii. Wolbachia was only observed in Ifangni, Pob&#xe8;, and Cotonou, while Microsporidia was detected in all study communes. Aggregated data for HLCs and PSCs showed a sporozoite rate (SR) of 0.80% (95% CI 0.09-2.87) and 0.69% (95% CI 0.09-2.87) for An. gambiae and An. coluzzii, respectively, with a mean of 0.74% (95% CI 0.20-1.90). Of the four individual mosquitoes which harboured P. falciparum, none were also infected with Wolbachia and one contained Microsporidia.<br><br>CONCLUSIONS: The present study is the first report of natural infections of field-collected An. gambiae s.l. populations from Benin with Wolbachia and Microsporidia. Sustained efforts should be made to widen the spectrum of bacteria identified in mosquitoes, with the potential to develop endosymbiont-based control tools; such interventions could be the game-changer in the control of malaria and arboviral disease transmission.}, }
@article {pmid38462506, year = {2024}, author = {Beasley-Hall, PG and Kinjo, Y and Rose, HA and Walker, J and Foster, CSP and Kovacs, TGL and Bourguignon, T and Ho, SYW and Lo, N}, title = {Shrinking in the dark: Parallel endosymbiont genome erosions are associated with repeated host transitions to an underground life.}, journal = {Insect science}, volume = {}, number = {}, pages = {}, doi = {10.1111/1744-7917.13339}, pmid = {38462506}, issn = {1744-7917}, support = {FT160100463//Australian Research Council/ ; }, abstract = {Microbial symbioses have had profound impacts on the evolution of animals. Conversely, changes in host biology may impact the evolutionary trajectory of symbionts themselves. Blattabacterium cuenoti is present in almost all cockroach species and enables hosts to subsist on a nutrient-poor diet. To investigate if host biology has impacted Blattabacterium at the genomic level, we sequenced and analyzed 25 genomes from Australian soil-burrowing cockroaches (Blaberidae: Panesthiinae), which have undergone at least seven separate subterranean, subsocial transitions from above-ground, wood-feeding ancestors. We find at least three independent instances of genome erosion have occurred in Blattabacterium strains exclusive to Australian soil-burrowing cockroaches. These shrinkages have involved the repeated inactivation of genes involved in amino acid biosynthesis and nitrogen recycling, the core role of Blattabacterium in the host-symbiont relationship. The most drastic of these erosions have occurred in hosts thought to have transitioned underground the earliest relative to other lineages, further suggestive of a link between gene loss in Blattabacterium and the burrowing behavior of hosts. As Blattabacterium is unable to fulfill its core function in certain host lineages, these findings suggest soil-burrowing cockroaches must acquire these nutrients from novel sources. Our study represents one of the first cases, to our knowledge, of parallel host adaptations leading to concomitant parallelism in their mutualistic symbionts, further underscoring the intimate relationship between these two partners.}, }
@article {pmid38468766, year = {2022}, author = {Fernández, MB and Bleidorn, C and Calcaterra, LA}, title = {Wolbachia Infection in Native Populations of the Invasive Tawny Crazy Ant Nylanderia fulva.}, journal = {Frontiers in insect science}, volume = {2}, number = {}, pages = {905803}, pmid = {38468766}, issn = {2673-8600}, abstract = {Antagonistic interactions can affect population growth and dispersal of an invasive species. Wolbachia are intracellular endosymbiont bacteria that infect arthropod and nematode hosts and are able to manipulate reproduction, which in some cases leads to cocladogenesis. Moreover, the presence of the strictly maternally transferred Wolbachia in a population can indirectly induce selective sweeps on the hosts' mitochondria. Ants have a Wolbachia infection rate of about 34%, which makes phylogenetic studies using mitochondrial markers vulnerable of being confounded by the effect of the endosymbiont. Nylanderia fulva is an invasive ant native to South America, considered a pest in the United States. Its distribution and biology are poorly known in its native range, and the taxonomic identity of this and its closely related species, Nylanderia pubens, has only recently been understood with the aid of molecular phylogenies. Aiming at estimating robust phylogenetic relationships of N. fulva in its native range, we investigated the presence and pattern of Wolbachia infection in populations of N. fulva from Argentina, part of its native range, to account for its possible effect on the host population structure. Using the ftsZ gene, 30 nests of N. fulva and four from sympatric Nylanderia species were screened for the presence of Wolbachia. We sequenced the MLST genes, the highly variable gene wsp, as well as glyQ, a novel target gene for which new primers were designed. Phylogeny of the ants was estimated using mtDNA (COI). We found supergroup A Wolbachia strains infecting 73% of N. fulva nests and two nests of Nylanderia sp. 1. Wolbachia phylogenetic tree inferred with MLST genes is partially congruent with the host phylogeny topology, with the exception of a lineage of strains shared by ants from different N. fulva clades. Furthermore, by comparing with Wolbachia sequences infecting other ants, we found that the strains infecting different N. fulva clades are not monophyletic. Our findings suggest there are three recent independent horizontally transmitted Wolbachia infections in N. fulva, and we found no evidence of influence of Wolbachia in the host mtDNA based phylogeny.}, }
@article {pmid38459641, year = {2024}, author = {Donner, SH and Slingerland, M and Beekman, MM and Comte, A and Dicke, M and Zwaan, BJ and Pannebakker, BA and Verhulst, EC}, title = {Aphid populations are frequently infected with facultative endosymbionts.}, journal = {Environmental microbiology}, volume = {26}, number = {3}, pages = {e16599}, doi = {10.1111/1462-2920.16599}, pmid = {38459641}, issn = {1462-2920}, support = {//Nederlandse Organisatie voor Wetenschappelijk Onderzoek/ ; KNAWWF/807/19002//Koninklijke Nederlandse Akademie van Wetenschappen/ ; //Koppert Biological Systems/ ; //Top Sector Horticulture &amp; Starting Materials (TKI T&amp;U)/ ; }, abstract = {The occurrence of facultative endosymbionts has been studied in many commercially important crop pest aphids, but their occurrence and effects in non-commercial aphid species in natural populations have received less attention. We screened 437 aphid samples belonging to 106 aphid species for the eight most common facultative aphid endosymbionts. We found one or more facultative endosymbionts in 53% (56 of 106) of the species investigated. This likely underestimates the situation in the field because facultative endosymbionts are often present in only some colonies of an aphid species. Oligophagous aphid species carried facultative endosymbionts significantly more often than monophagous species. We did not find a significant correlation between ant tending and facultative endosymbiont presence. In conclusion, we found that facultative endosymbionts are common among aphid populations. This study is, to our knowledge, the first of its kind in the Netherlands and provides a basis for future research in this field. For instance, it is still unknown in what way many of these endosymbionts affect their hosts, which is important for determining the importance of facultative endosymbionts to community dynamics.}, }
@article {pmid38457881, year = {2024}, author = {Lintner, M and Schagerl, M and Lintner, B and Wanek, W and Goleń, J and Tyszka, J and Heinz, P}, title = {Impact of pesticides on marine coral reef foraminifera.}, journal = {Marine pollution bulletin}, volume = {201}, number = {}, pages = {116237}, doi = {10.1016/j.marpolbul.2024.116237}, pmid = {38457881}, issn = {1879-3363}, abstract = {Our laboratory study looked into how pesticides affect the foraminifera species Heterostegina depressa and their obligatory algal endosymbionts. We incubated the foraminifera separately with different types of pesticides at varying concentrations (1 %, 0.01 % and 0.0001 %); we included the insecticide Confidor© (active substance: imidacloprid), the fungicide Pronto©Plus (tebuconazole), and the herbicide Roundup© (glyphosate). Our evaluation focused on the symbiont's photosynthetically active area (PA), and the uptake of dissolved inorganic carbon (DIC) and nitrogen (nitrate) to determine the vitality of the foraminifera. Our findings showed that even the lowest doses of the fungicide and herbicide caused irreparable damage to the foraminifera and their symbionts. While the insecticide only deactivated the symbionts (PA = 0) at the highest concentration (1 %), the fungicide, and herbicide caused complete deactivation even at the lowest levels provided (0.0001 %). The fungicide had the strongest toxic effect on the foraminiferal host regarding reduced isotope uptake. In conclusion, all pesticides had a negative impact on the holosymbiont, with the host showing varying degrees of sensitivity towards different types of pesticides.}, }
@article {pmid38456555, year = {2024}, author = {Malandrakis, AA and Varikou, K and Kavroulakis, &#x39d; and Nikolakakis, A and Dervisi, I and Reppa, C&#x399; and Papadakis, S and Holeva, MC and Chrysikopoulos, CV}, title = {Copper nanoparticles interfere with insecticide sensitivity, fecundity and endosymbiont abundance in olive fruit fly Bactrocera oleae (Diptera: Tephritidae).}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.8068}, pmid = {38456555}, issn = {1526-4998}, abstract = {BACKGROUND: The potential of copper nanoparticles (NPs) to be used as an alternative control strategy against olive fruit flies (Bactrocera oleae) with reduced sensitivity to the pyrethroid deltamethrin and the impact of both nanosized and bulk copper [Cu(OH)2 ] on the insect's reproductive and endosymbiotic parameters were investigated.<br><br>RESULTS: The application of nanosized and bulk copper applied by feeding resulted in significant levels of adult mortality, comparable to or surpassing those achieved with deltamethrin at recommended doses. Combinations of Cu-NPs or CuO-NPs with deltamethrin significantly enhanced the insecticide's efficacy against B. oleae adults. When combined with deltamethrin, Cu-NPs significantly reduced the mean total number of offspring compared with the control, and the number of stings, pupae, female and total number of offspring compared with the insecticide alone. Both bulk and nanosized copper negatively affected the abundance of the endosymbiotic bacterium Candidatus Erwinia dacicola which is crucial for the survival of B. oleae larvae.<br><br>CONCLUSION: Cu-NPs can aid the control of B. oleae both by reducing larval survival and by enhancing deltamethrin performance in terms of toxicity and reduced fecundity, providing an effective anti-resistance tool and minimizing the environmental footprint of synthetic pesticides by reducing the required doses for the control of the pest.}, }
@article {pmid38456084, year = {2024}, author = {Kumar, V and Subramanian, J and Marimuthu, M and Subbarayalu, M and Ramasamy, V and Gandhi, K and Ariyan, M}, title = {Diversity and functional characteristics of culturable bacterial endosymbionts from cassava whitefly biotype Asia II-5, Bemisia tabaci.}, journal = {3 Biotech}, volume = {14}, number = {4}, pages = {100}, doi = {10.1007/s13205-024-03949-0}, pmid = {38456084}, issn = {2190-572X}, abstract = {UNLABELLED: Whitefly Bemisia tabaci, a carrier of cassava mosaic disease (CMD), poses a significant threat to cassava crops. Investigating culturable bacteria and their impact on whiteflies is crucial due to their vital role in whitefly fitness and survival. The whitefly biotype associated with cassava and transmitting CMD in India has been identified as Asia II 5 through partial mitochondrial cytochrome oxidase I gene sequencing. In this study, bacteria associated with adult B. tabaci feeding on cassava were extracted using seven different media. Nutrient Agar (NA), Soyabean Casein Digest Medium (SCDM), Luria Bertani agar (LBA), and Reasoner's 2A agar (R2A) media resulted in 19, 6, 4, and 4 isolates, respectively, producing a total of 33 distinct bacterial isolates. Species identification through 16SrRNA gene sequencing revealed that all isolates belonged to the Bacillota and Pseudomonadota phyla, encompassing 11 genera: Bacillus, Cytobacillus, Exiguobacterium, Terribacillus, Brevibacillus, Enterococcus, Staphylococcus, Brucella, Novosphingobium, Lysobacter, and Pseudomonas. All bacterial isolates were tested for chitinase, protease, siderophore activity, and antibiotic sensitivity. Nine isolates exhibited chitinase activity, 28 showed protease activity, and 23 displayed siderophore activity. Most isolates were sensitive to antibiotics such as Vancomycin, Streptomycin, Erythromycin, Kanamycin, Doxycycline, Tetracycline, and Ciprofloxacin, while they demonstrated resistance to Bacitracin and Colistin. Understanding the culturable bacteria associated with cassava whitefly and their functional significance could contribute to developing effective cassava whitefly and CMD control in agriculture.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-024-03949-0.}, }
@article {pmid38455147, year = {2024}, author = {Hafer-Hahmann, N and Vorburger, C}, title = {Parasitoid species diversity has no effect on protective symbiont diversity in experimental host-parasitoid populations.}, journal = {Ecology and evolution}, volume = {14}, number = {3}, pages = {e11090}, doi = {10.1002/ece3.11090}, pmid = {38455147}, issn = {2045-7758}, abstract = {How does diversity in nature come about? One factor contributing to this diversity are species interactions; diversity on one trophic level can shape diversity on lower or higher trophic levels. For example, parasite diversity enhances host immune diversity. Insect protective symbionts mediate host resistance and are, therefore, also engaged in reciprocal selection with their host's parasites. Here, we applied experimental evolution in a well-known symbiont-aphid-parasitoid system to study whether parasitoid diversity contributes to maintaining symbiont genetic diversity. We used caged populations of black bean aphids (Aphis fabae), containing uninfected individuals and individuals infected with different strains of the bacterial endosymbiont Hamiltonella defensa, which protects aphids against parasitoids. Over multiple generations, these populations were exposed to three different species of parasitoid wasps (Aphidius colemani, Binodoxys acalephae or Lysiphlebus fabarum), simultaneous or sequential mixtures of these species or no wasps. Surprisingly, we observed little selection for H. defensa in most treatments, even when it clearly provided protection against a fatal parasitoid infection. This seemed to be caused by high induced costs of resistance: aphids surviving parasitoid attacks suffered an extreme reduction in fitness. In marked contrast to previous studies looking at the effect of different genotypes of a single parasitoid species, we found little evidence for a diversifying effect of multiple parasitoid species on symbiont diversity in hosts.}, }
@article {pmid38452081, year = {2024}, author = {Kaur, R and McGarry, A and Shropshire, JD and Leigh, BA and Bordenstein, SR}, title = {Prophage proteins alter long noncoding RNA and DNA of developing sperm to induce a paternal-effect lethality.}, journal = {Science (New York, N.Y.)}, volume = {383}, number = {6687}, pages = {1111-1117}, doi = {10.1126/science.adk9469}, pmid = {38452081}, issn = {1095-9203}, abstract = {The extent to which prophage proteins interact with eukaryotic macromolecules is largely unknown. In this work, we show that cytoplasmic incompatibility factor A (CifA) and B (CifB) proteins, encoded by prophage WO of the endosymbiont Wolbachia, alter long noncoding RNA (lncRNA) and DNA during Drosophila sperm development to establish a paternal-effect embryonic lethality known as cytoplasmic incompatibility (CI). CifA is a ribonuclease (RNase) that depletes a spermatocyte lncRNA important for the histone-to-protamine transition of spermiogenesis. Both CifA and CifB are deoxyribonucleases (DNases) that elevate DNA damage in late spermiogenesis. lncRNA knockdown enhances CI, and mutagenesis links lncRNA depletion and subsequent sperm chromatin integrity changes to embryonic DNA damage and CI. Hence, prophage proteins interact with eukaryotic macromolecules during gametogenesis to create a symbiosis that is fundamental to insect evolution and vector control.}, }
@article {pmid38444236, year = {2024}, author = {Manentzos, AN and Pahl, AMC and Melloh, P and Martin, EA and Leybourne, DJ}, title = {Low prevalence of secondary endosymbionts in aphids sampled from rapeseed crops in Germany.}, journal = {Bulletin of entomological research}, volume = {}, number = {}, pages = {1-6}, doi = {10.1017/S0007485324000063}, pmid = {38444236}, issn = {1475-2670}, support = {RF-2022-100004//Royal Commission for the Exhibition of 1851/ ; }, abstract = {Peach-potato aphids, Myzus persicae Sulzer (Hemiptera:Aphididae), and cabbage aphids, Brevicoryne brassicae Linnaeus (Hemiptera:Aphididae), are herbivorous insects of significant agricultural importance. Aphids can harbour a range of non-essential (facultative) endosymbiotic bacteria that confer multiple costs and benefits to the host aphid. A key endosymbiont-derived phenotype is protection against parasitoid wasps, and this protective phenotype has been associated with several defensive enodsymbionts. In recent years greater emphasis has been placed on developing alternative pest management strategies, including the increased use of natural enemies such as parasitoids wasps. For the success of aphid control strategies to be estimated the presence of defensive endosymbionts that can potentially disrupt the success of biocontrol agents needs to be determined in natural aphid populations. Here, we sampled aphids and mummies (parasitised aphids) from an important rapeseed production region in Germany and used multiplex PCR assays to characterise the endosymbiont communities. We found that aphids rarely harboured facultative endosymbionts, with 3.6% of M. persicae and 0% of B. brassicae populations forming facultative endosymbiont associations. This is comparable with endosymbiont prevalence described for M. persicae populations surveyed in Australia, Europe, Chile, and USA where endosymbiont infection frequencies range form 0-2%, but is in contrast with observations from China where M. persicae populations have more abundant and diverse endosymbiotic communities (endosymbionts present in over 50% of aphid populations).}, }
@article {pmid38443775, year = {2024}, author = {Molina-Garza, ZJ and Cuesy-León, M and Baylón-Pacheco, L and Rosales-Encina, JL and Galaviz-Silva, L}, title = {Diversity of midgut microbiota in ticks collected from white-tailed deer (Odocoileus virginianus) from northern Mexico.}, journal = {Parasites, hosts and diseases}, volume = {62}, number = {1}, pages = {117-130}, doi = {10.3347/PHD.23006}, pmid = {38443775}, issn = {2982-6799}, support = {#3157//FOINS PN-CONACyT/ ; //PAICyT-UANL/ ; //CONACyT/ ; }, abstract = {Ticks host different pathogens as endosymbiont and nonpathogenic microorganisms and play an important role in reproductive fitness and nutrient provision. However, the bacterial microbiomes of white-tailed deer ticks have received minimal attention. This study aimed to examine the bacterial microbiome of ticks collected from Odocoileus virginianus on the Mexico-United States border to assess differences in microbiome diversity in ticks of different species, sexes, and localities. Five different tick species were collected: Rhipicephalus microplus, Dermacentor nitens, Otobius megnini, Amblyomma cajennense, and A. maculatum. The tick microbiomes were analyzed using next-generation sequencing. Among all tick species, the most predominant phylum was Proteobacteria, followed by Actinobacteria and Firmicutes. The ticks from Tamaulipas and Nuevo León presented the highest bacterial species diversity. Acinetobacter johnsonii and A. lwoffii were the common bacterial species in the microbiome of all ticks, Coxiella were present in R. microplus, and Dermacentor nitens also exhibited a Francisella-like endosymbiont. The microbiome of most females in D. nitens was less diverse than that of males, whereas R. microplus occurs in females, suggesting that microbiome diversity is influenced by sex. In the bacterial communities of A. maculatum and O. megnini, Candidatus Midichloria massiliensis, and Candidatus Endoecteinascidia fumentensis were the most predominant endosymbionts. These results constitute the initial report on these bacteria, and this is also the first study to characterize the microbiome of O. megnini.}, }
@article {pmid38439943, year = {2024}, author = {González Porras, M&#xc1; and Pons, I and García-Lozano, M and Jagdale, S and Emmerich, C and Weiss, B and Salem, H}, title = {Extracellular symbiont colonizes insect during embryo development.}, journal = {ISME communications}, volume = {4}, number = {1}, pages = {ycae005}, pmid = {38439943}, issn = {2730-6151}, abstract = {Insects typically acquire their beneficial microbes early in development. Endosymbionts housed intracellularly are commonly integrated during oogenesis or embryogenesis, whereas extracellular microbes are only known to be acquired after hatching by immature instars such as larvae or nymphs. Here, however, we report on an extracellular symbiont that colonizes its host during embryo development. Tortoise beetles (Chrysomelidae: Cassidinae) host their digestive bacterial symbiont Stammera extracellularly within foregut symbiotic organs and in ovary-associated glands to ensure its vertical transmission. We outline the initial stages of symbiont colonization and observe that although the foregut symbiotic organs develop 3 days prior to larval emergence, they remain empty until the final 24 h of embryo development. Infection by Stammera occurs during that timeframe and prior to hatching. By experimentally manipulating symbiont availability to embryos in the egg, we describe a 12-h developmental window governing colonization by Stammera. Symbiotic organs form normally in aposymbiotic larvae, demonstrating that these Stammera-bearing structures develop autonomously. In adults, the foregut symbiotic organs are already colonized following metamorphosis and host a stable Stammera population to facilitate folivory. The ovary-associated glands, however, initially lack Stammera. Symbiont abundance subsequently increases within these transmission organs, thereby ensuring sufficient titers at the onset of oviposition ~29 days following metamorphosis. Collectively, our findings reveal that Stammera colonization precedes larval emergence, where its proliferation is eventually decoupled in adult beetles to match the nutritional and reproductive requirements of its host.}, }
@article {pmid38438424, year = {2024}, author = {Tan, KXY and Shigenobu, S}, title = {In vivo interference of pea aphid endosymbiont Buchnera groEL gene by synthetic peptide nucleic acids.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {5378}, pmid = {38438424}, issn = {2045-2322}, support = {Scholarship//Ministry of Education, Culture, Sports, Science and Technology/ ; JP20H00478//Japan Society for the Promotion of Science/ ; }, abstract = {The unculturable nature of intracellular obligate symbionts presents a significant challenge for elucidating gene functionality, necessitating the development of gene manipulation techniques. One of the best-studied obligate symbioses is that between aphids and the bacterial endosymbiont Buchnera aphidicola. Given the extensive genome reduction observed in Buchnera, the remaining genes are crucial for understanding the host-symbiont relationship, but a lack of tools for manipulating gene function in the endosymbiont has significantly impeded the exploration of the molecular mechanisms underlying this mutualism. In this study, we introduced a novel gene manipulation technique employing synthetic single-stranded peptide nucleic acids (PNAs). We targeted the critical Buchnera groEL using specially designed antisense PNAs conjugated to an arginine-rich cell-penetrating peptide (CPP). Within 24 h of PNA administration via microinjection, we observed a significant reduction in groEL expression and Buchnera cell count. Notably, the interference of groEL led to profound morphological malformations in Buchnera, indicative of impaired cellular integrity. The gene knockdown technique developed in this study, involving the microinjection of CPP-conjugated antisense PNAs, provides a potent approach for in vivo gene manipulation of unculturable intracellular symbionts, offering valuable insights into their biology and interactions with hosts.}, }
@article {pmid38437189, year = {2024}, author = {Dye, D and Cain, JW}, title = {Efficacy of Wolbachia-based mosquito control: Predictions of a spatially discrete mathematical model.}, journal = {PloS one}, volume = {19}, number = {3}, pages = {e0297964}, doi = {10.1371/journal.pone.0297964}, pmid = {38437189}, issn = {1932-6203}, abstract = {Wolbachia is an endosymbiont bacterium present in many insect species. When Wolbachia-carrying male Aedes aegypti mosquitoes mate with non-carrier females, their embryos are not viable due to cytoplasmic incompatibility. This phenomenon has been exploited successfully for the purpose of controlling mosquito populations and the spread of mosquito-borne illnesses: Wolbachia carriers are bred and released into the environment. Because Wolbachia is not harmful to humans, this method of mosquito control is regarded as a safer alternative to pesticide spraying. In this article, we introduce a mathematical framework for exploring (i) whether a one-time release of Wolbachia carriers can elicit a sustained presence of carriers near the release site, and (ii) the extent to which spatial propagation of carriers may allow them to establish fixation in other territories. While some prior studies have formulated mosquito dispersal models using advection-reaction-diffusion PDEs, the predictive power of such models requires careful ecological mapping: advection and diffusion coefficients exhibit significant spatial dependence due to heterogeneity of resources and topography. Here, we adopt a courser-grained view, regarding the environment as a network of discrete, diffusively-coupled "habitats"-distinct zones of high mosquito density such as stagnant ponds. We extend two previously published single-habitat mosquito models to multiple habitats, and calculate rates of migration between pairs of habitats using dispersal kernels. Our primary results are quantitative estimates regarding how the success of carrier fixation in one or more habitats is determined by: the number of carriers released, sizes of habitats, distances between habitats, and the rate of migration between habitats. Besides yielding sensible and potentially useful predictions regarding the success of Wolbachia-based control, our framework applies to other approaches (e.g., gene drives) and contexts beyond the realm of insect pest control.}, }
@article {pmid38431055, year = {2024}, author = {Walt, HK and King, JG and Sheele, JM and Meyer, F and Pietri, JE and Hoffmann, FG}, title = {Do bed bugs transmit human viruses, or do humans spread bed bugs and their viruses? A worldwide survey of the bed bug RNA virosphere.}, journal = {Virus research}, volume = {}, number = {}, pages = {199349}, doi = {10.1016/j.virusres.2024.199349}, pmid = {38431055}, issn = {1872-7492}, abstract = {BED BUGS (HEMIPTERA: : Cimicidae) are a globally distributed hematophagous pest that routinely feed on humans. Unlike many blood-sucking arthropods, they have never been linked to pathogen transmission in a natural setting, and despite increasing interest in their role as disease vectors, little is known about the viruses that bed bugs naturally harbor. Here, we present a global-scale survey of the bed bug RNA virosphere. We sequenced the metatranscriptomes of 22 individual bed bugs (Cimex lectularius and Cimex hemipterus) from 8 locations around the world. We detected sequences from two known bed bug viruses (Shuangao bedbug virus 1 and Shuangao bedbug virus 2) which extends their geographical range. We identified three novel bed bug virus sequences from a tenui-like virus (Bunyavirales), a toti-like virus (Ghabrivirales), and a luteo-like virus (Tolivirales). Interestingly, some of the bed bug viruses branch near to insect-transmitted plant-infecting viruses, opening questions regarding the evolution of plant virus infection. When we analyzed the viral sequences by their host's collection location, we found unexpected patterns of geographical diversity that may reflect humans' role in bed bug dispersal. Additionally, we investigated the effect that Wolbachia, the primary bed bug endosymbiont, may have on viral abundance and found that Wolbachia infection neither promotes nor inhibits viral infection. Finally, our results provide no evidence that bed bugs transmit any known human pathogenic viruses.}, }
@article {pmid38426058, year = {2024}, author = {Cantin, LJ and Dunning Hotopp, JC and Foster, JM}, title = {Improved metagenome assemblies through selective enrichment of bacterial genomic DNA from eukaryotic host genomic DNA using ATAC-seq.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1352378}, pmid = {38426058}, issn = {1664-302X}, abstract = {Genomics can be used to study the complex relationships between hosts and their microbiota. Many bacteria cannot be cultured in the laboratory, making it difficult to obtain adequate amounts of bacterial DNA and to limit host DNA contamination for the construction of metagenome-assembled genomes (MAGs). For example, Wolbachia is a genus of exclusively obligate intracellular bacteria that live in a wide range of arthropods and some nematodes. While Wolbachia endosymbionts are frequently described as facultative reproductive parasites in arthropods, the bacteria are obligate mutualistic endosymbionts of filarial worms. Here, we achieve 50-fold enrichment of bacterial sequences using ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) with Brugia malayi nematodes, containing Wolbachia (wBm). ATAC-seq uses the Tn5 transposase to cut and attach Illumina sequencing adapters to accessible DNA lacking histones, typically thought to be open chromatin. Bacterial and mitochondrial DNA in the lysates are also cut preferentially since they lack histones, leading to the enrichment of these sequences. The benefits of this include minimal tissue input (<1 mg of tissue), a quick protocol (<4 h), low sequencing costs, less bias, correct assembly of lateral gene transfers and no prior sequence knowledge required. We assembled the wBm genome with as few as 1 million Illumina short paired-end reads with >97% coverage of the published genome, compared to only 12% coverage with the standard gDNA libraries. We found significant bacterial sequence enrichment that facilitated genome assembly in previously published ATAC-seq data sets from human cells infected with Mycobacterium tuberculosis and C. elegans contaminated with their food source, the OP50 strain of E. coli. These results demonstrate the feasibility and benefits of using ATAC-seq to easily obtain bacterial genomes to aid in symbiosis, infectious disease, and microbiome research.}, }
@article {pmid38414566, year = {2024}, author = {Ffrench-Constant, RH and Bennie, J and Gordon, IJ and Depew, L and Smith, DAS}, title = {Penetrance interactions of colour pattern loci in the African Monarch and their implications for the evolution of dominance.}, journal = {Ecology and evolution}, volume = {14}, number = {2}, pages = {e11024}, pmid = {38414566}, issn = {2045-7758}, abstract = {Scoring the penetrance of heterozygotes in complex phenotypes, like colour pattern, is difficult and complicates the analysis of systems in which dominance is incomplete or evolving. The African Monarch (Danaus chrysippus) represents an example where colour pattern heterozygotes, formed in the contact zone between the different subspecies, show such intermediate dominance. Colour pattern in this aposematic butterfly is controlled by three loci A, B and C. The B and C loci are closely linked in a B/C supergene and significant interaction of B and C phenotypes is therefore expected via linkage alone. The A locus, however, is not linked to B/C and is found on a different chromosome. To study interactions between these loci we generated colour pattern heterozygotes by crossing males and females bearing different A and B/C genotypes, collected from different parts of Africa. We derived a novel scoring system for the expressivity of the heterozygotes and, as predicted, we found significant interactions between the genotypes of the closely linked B and C loci. Surprisingly, however, we also found highly significant interactions between C and the unlinked A locus, modifications that generally increased the resemblance of heterozygotes to homozygous ancestors. In contrast, we found no difference in the penetrance of any of the corresponding heterozygotes from crosses conducted either in allopatry or sympatry, in reciprocal crosses of males and females, or in the presence or absence of endosymbiont mediated male-killing or its associated neoW mediated sex-linkage of colour pattern. Together, this data supports the idea that the different colour morphs of the African Monarch meet transiently in the East African contact zone and that genetic modifiers act to mask inappropriate expression of colour patterns in the incorrect environments.}, }
@article {pmid38408183, year = {2024}, author = {Paddock, CD and Zambrano, ML and Clover, JR and Ladd-Wilson, S and Dykstra, EA and Salamone, A and Kangiser, D and Ayres, BN and Shooter, SL and Karpathy, SE and Kjemtrup, AM and Beati, L and Levin, ML and Lane, RS and Zazueta, OE}, title = {Rickettsia species identified in adult, host-seeking Dermacentor occidentalis (Acari: Ixodidae) from Baja California, Mexico, and Oregon and Washington, United States.}, journal = {Journal of medical entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jme/tjae023}, pmid = {38408183}, issn = {1938-2928}, abstract = {The Pacific Coast tick (Dermacentor occidentalis Marx, 1892) is a frequently encountered and commonly reported human-biting tick species that has been recorded from most of California and parts of southwestern Oregon, southcentral Washington, and northwestern Mexico. Although previous investigators have surveyed populations of D. occidentalis for the presence of Rickettsia species across several regions of California, populations of this tick have not been surveyed heretofore for rickettsiae from Baja California, Oregon, or Washington. We evaluated 1,367 host-seeking, D. occidentalis adults collected from 2015 to 2022 by flagging vegetation at multiple sites in Baja California, Mexico, and Oregon and Washington, United States, using genus- and species-specific assays for spotted fever group rickettsiae. DNA of Rickettsia 364D, R. bellii, and R. tillamookensis was not detected in specimens from these regions. DNA of R. rhipicephali was detected in D. occidentalis specimens obtained from Ensenada Municipality in Baja California and southwestern Oregon, but not from Washington. All ompA sequences of R. rhipichephali that were amplified from individual ticks in southwestern Oregon were represented by a single genotype. DNA of the Ixodes pacificus rickettsial endosymbiont was amplified from specimens collected in southwestern Oregon and Klickitat County, Washington; to the best of our knowledge, this Rickettsia species has never been identified in D. occidentalis. Collectively, these data are consistent with a relatively recent introduction of Pacific Coast ticks in the northernmost extension of its recognized range.}, }
@article {pmid38403930, year = {2024}, author = {Lastovetsky, OA and Caruso, T and Brennan, FP and Wall, D and Pylni, S and Doyle, E}, title = {Spores of arbuscular mycorrhizal fungi host surprisingly diverse communities of endobacteria.}, journal = {The New phytologist}, volume = {}, number = {}, pages = {}, doi = {10.1111/nph.19605}, pmid = {38403930}, issn = {1469-8137}, support = {GOIPD/2017/879//Irish Research Council/ ; }, abstract = {Arbuscular mycorrhizal fungi (AMF) are ubiquitous plant root symbionts, which can house two endobacteria: Ca. Moeniiplasma glomeromycotorum (CaMg) and Ca. Glomeribacter gigasporarum (CaGg). However, little is known about their distribution and population structure in natural AMF populations and whether AMF can harbour other endobacteria. We isolated AMF from two environments and conducted detailed analyses of endobacterial communities associated with surface-sterilised AMF spores. Consistent with the previous reports, we found that CaMg were extremely abundant (80%) and CaGg were extremely rare (2%) in both environments. Unexpectedly, we discovered an additional and previously unknown level of bacterial diversity within AMF spores, which extended beyond the known endosymbionts, with bacteria belonging to 10 other phyla detected across our spore data set. Detailed analysis revealed that: CaGg were not limited in distribution to the Gigasporaceae family of AMF, as previously thought; CaMg population structure was driven by AMF host genotype; and a significant inverse correlation existed between the diversity of CaMg and diversity of all other endobacteria. Based on these data, we generate novel testable hypotheses regarding the function of CaMg in AMF biology by proposing that they might act as conditional mutualists of AMF.}, }
@article {pmid38399702, year = {2024}, author = {Cameirão, C and Costa, D and Rufino, J and Pereira, JA and Lino-Neto, T and Baptista, P}, title = {Diversity, Composition, and Specificity of the Philaenus spumarius Bacteriome.}, journal = {Microorganisms}, volume = {12}, number = {2}, pages = {}, pmid = {38399702}, issn = {2076-2607}, support = {UIDB/00690/2020; UIDP/00690/2020; LA/P/0007/2020; UIDB/04050/2020; UIDB/05757/2020 and UIDP/05757/2020//Funda&#xe7;&#xe3;o para a Ci&#xea;ncia e Tecnologia/ ; PRR-C05-i03-I-000083//Agriculture and Fisheries Financing Institute/ ; 727987//Horizon2020/ ; }, abstract = {Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Aphrophoridae) was recently classified as a pest due to its ability to act as a vector of the phytopathogen Xylella fastidiosa. This insect has been reported to harbour several symbiotic bacteria that play essential roles in P. spumarius health and fitness. However, the factors driving bacterial assemblages remain largely unexplored. Here, the bacteriome associated with different organs (head, abdomen, and genitalia) of males and females of P. spumarius was characterized using culturally dependent and independent methods and compared in terms of diversity and composition. The bacteriome of P. spumarius is enriched in Proteobacteria, Bacteroidota, and Actinobacteria phyla, as well as in Candidatus Sulcia and Cutibacterium genera. The most frequent isolates were Curtobacterium, Pseudomonas, and Rhizobiaceae sp.1. Males display a more diverse bacterial community than females, but no differences in diversity were found in distinct organs. However, the organ shapes the bacteriome structure more than sex, with the Microbacteriaceae family revealing a high level of organ specificity and the Blattabacteriaceae family showing a high level of sex specificity. Several symbiotic bacterial genera were identified in P. spumarius for the first time, including Rhodococcus, Citrobacter, Halomonas, Streptomyces, and Providencia. Differences in the bacterial composition within P. spumarius organs and sexes suggest an adaptation of bacteria to particular insect tissues, potentially shaped by their significance in the life and overall fitness of P. spumarius. Although more research on the bacteria of P. spumarius interactions is needed, such knowledge could help to develop specific bacterial-based insect management strategies.}, }
@article {pmid38392507, year = {2024}, author = {Cheng, Y and Yang, J and Li, T and Li, J and Ye, M and Wang, J and Chen, R and Zhu, L and Du, B and He, G}, title = {Endosymbiotic Fungal Diversity and Dynamics of the Brown Planthopper across Developmental Stages, Tissues, and Sexes Revealed Using Circular Consensus Sequencing.}, journal = {Insects}, volume = {15}, number = {2}, pages = {}, pmid = {38392507}, issn = {2075-4450}, support = {2022ABA001//The Science and Technology Major Program of Hubei Province/ ; }, abstract = {Endosymbiotic fungi play an important role in the growth and development of insects. Understanding the endosymbiont communities hosted by the brown planthopper (BPH; Nilaparvata lugens Stål), the most destructive pest in rice, is a prerequisite for controlling BPH rice infestations. However, the endosymbiont diversity and dynamics of the BPH remain poorly studied. Here, we used circular consensus sequencing (CCS) to obtain 87,131 OTUs (operational taxonomic units), which annotated 730 species of endosymbiotic fungi in the various developmental stages and tissues. We found that three yeast-like symbionts (YLSs), Polycephalomyces prolificus, Ophiocordyceps heteropoda, and Hirsutella proturicola, were dominant in almost all samples, which was especially pronounced in instar nymphs 4-5, female adults, and the fat bodies of female and male adult BPH. Interestingly, honeydew as the only in vitro sample had a unique community structure. Various diversity indices might indicate the different activity of endosymbionts in these stages and tissues. The biomarkers analyzed using LEfSe suggested some special functions of samples at different developmental stages of growth and the active functions of specific tissues in different sexes. Finally, we found that the incidence of occurrence of three species of Malassezia and Fusarium sp. was higher in males than in females in all comparison groups. In summary, our study provides a comprehensive survey of symbiotic fungi in the BPH, which complements the previous research on YLSs. These results offer new theoretical insights and practical implications for novel pest management strategies to understand the BPH-microbe symbiosis and devise effective pest control strategies.}, }
@article {pmid38392506, year = {2024}, author = {Budrys, E and Orlovskytė, S and Budrienė, A}, title = {Ecological Speciation without Morphological Differentiation? A New Cryptic Species of Diodontus Curtis (Hymenoptera, Pemphredonidae) from the Centre of Europe.}, journal = {Insects}, volume = {15}, number = {2}, pages = {}, doi = {10.3390/insects15020086}, pmid = {38392506}, issn = {2075-4450}, support = {Contract No S-MIP-20-23//Lietuvos Mokslo Taryba/ ; }, abstract = {Upon exploring the mitotype diversity of the aphid-hunting wasp, Diodontus tristis, we revealed specimens with highly divergent mitotypes from two localities in Lithuania and nesting in clayey substrate, while the specimens with typical mitotypes were found nesting in sandy sites. The comparison of inter- and intra-specific distances and application of delimitation algorithms supported the species status of the clay-nesting populations. Using a set of DNA markers that included complete or partial sequences of six mitochondrial genes, three markers of ribosomal operon, two homeobox genes, and four other nuclear genes, we clarified the phylogenetic relationships of the new cryptic species. The endosymbiotic bacteria infestation was checked, considering the option that the divergent populations may represent clades isolated by Wolbachia infection; however, it did not demonstrate any specificity. We found only subtle morphological differences in the new clay-nesting species, D. argillicola sp. nov.; the discriminant analysis of morphometric measurements did not reliably segregate it as well. Thus, we provide the molecular characters of the cryptic species, which allow confident identification, its phylogenetic position within the genus, and an updated identification key for the D. tristis species group.}, }
@article {pmid38392339, year = {2024}, author = {Reese, C and Graber, LC and Ramalho, MO and Moreau, CS}, title = {The Diversity of Wolbachia across the Turtle Ants (Formicidae: Cephalotes spp.).}, journal = {Biology}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/biology13020121}, pmid = {38392339}, issn = {2079-7737}, support = {DGE-1650441; NSF DEB 1900357//National Science Foundation/ ; }, abstract = {Wolbachia is a widespread and well-known bacterium that can induce a wide range of changes within its host. Ants specifically harbor a great deal of Wolbachia diversity and are useful systems to study endosymbiosis. The turtle ants (Cephalotes) are a widespread group of tropical ants that rely on gut microbes to support their herbivorous diet for their survival, yet little is known of the extent of this diversity. Therefore, studying their endosymbionts and categorizing the diversity of bacteria within Cephalotes hosts could help to delimit species and identify new strains and can help lead to a further understanding of how the microbiome leads to survival and speciation in the wild. In our study, 116 individual samples were initially tested for positive infection with the wsp gene. Of the initial 116 samples, 9 samples were infected with only one strain of Wolbachia, and 7 were able to be used successfully for multilocus sequence typing (MLST). We used the new MLST data to infer a phylogeny with other Formicidae samples from the MLST online database to identify new Wolbachia strains and related genes, of which only one came back as an exact match. The 18 Wolbachia-positive samples ranged across 15 different species and 7 different countries, which we further test for species identity and geographic correlation. This study is the first comprehensive look into the diversity of Wolbachia in the turtle ants, providing insight into how endosymbionts are oriented in widespread species and providing a strong foundation for further research in host-microbe interactions.}, }
@article {pmid38390299, year = {2024}, author = {Baruah, N and Haajanen, R and Rahman, MT and Pirttilä, AM and Koskimäki, JJ}, title = {Biosynthesis of polyhydroxybutyrate by Methylorubrum extorquens DSM13060 is essential for intracellular colonization in plant endosymbiosis.}, journal = {Frontiers in plant science}, volume = {15}, number = {}, pages = {1302705}, doi = {10.3389/fpls.2024.1302705}, pmid = {38390299}, issn = {1664-462X}, abstract = {Methylorubrum extorquens DSM13060 is an endosymbiont that lives in the cells of shoot tip meristems. The bacterium is methylotrophic and consumes plant-derived methanol for the production of polyhydroxybutyrate (PHB). The PHB provides protection against oxidative stress for both host and endosymbiont cells through its fragments, methyl-esterified 3-hydroxybutyrate (ME-3HB) oligomers. We evaluated the role of the genes involved in the production of ME-3HB oligomers in the host colonization by the endosymbiont M. extorquens DSM13060 through targeted genetic mutations. The strains with deletions in PHB synthase (phaC), PHB depolymerase (phaZ1), and a transcription factor (phaR) showed altered PHB granule characteristics, as ΔphaC had a significantly low number of granules, ΔphaR had a significantly increased number of granules, and ΔphaZ1 had significantly large PHB granules in the bacterial cells. When the deletion strains were exposed to oxidative stress, the ΔphaC strain was sensitive to 10 mM HO· and 20 mM H2O2. The colonization of the host, Scots pine (Pinus sylvestris L.), by the deletion strains varied greatly. The deletion strain ΔphaR colonized the host mainly intercellularly, whereas the ΔphaZ1 strain was a slightly poorer colonizer than the control. The deletion strain ΔphaC lacked the colonization potential, living mainly on the surfaces of the epidermis of pine roots and shoots in contrast to the control, which intracellularly colonized all pine tissues within the study period. In earlier studies, deletions within the PHB metabolic pathway have had a minor effect on plant colonization by rhizobia. We have previously shown the association between ME-3HB oligomers, produced by PhaC and PhaZ1, and the ability to alleviate host-generated oxidative stress during plant infection by the endosymbiont M. extorquens DSM13060. Our current results show that the low capacity for PHB synthesis leads to poor tolerance of oxidative stress and loss of colonization potential by the endosymbiont. Altogether, our findings demonstrate that the metabolism of PHB in M. extorquens DSM13060 is an important trait in the non-rhizobial endosymbiosis.}, }
@article {pmid38381797, year = {2024}, author = {Mendoza-Roldan, JA and Perles, L and Filippi, E and Szafranski, N and Montinaro, G and Carbonara, M and Scalera, R and de Abreu Teles, PP and Walochnik, J and Otranto, D}, title = {Parasites and microorganisms associated with the snakes collected for the "festa Dei serpari" in Cocullo, Italy.}, journal = {PLoS neglected tropical diseases}, volume = {18}, number = {2}, pages = {e0011973}, doi = {10.1371/journal.pntd.0011973}, pmid = {38381797}, issn = {1935-2735}, abstract = {While in much of the Western world snakes are feared, in the small, rural, mountainous town of Cocullo, in the middle of central Italy, snakes are annually collected and celebrated in a sacro-profane ritual. Every 1st of May, Serpari (snake catchers) capture and showcase dozens of non-venomous snakes to celebrate the ritual of San Domenico. In order to detect potential zoonotic pathogens within this unique epidemiological context, parasites and microorganisms of snakes harvested for the "festa dei serpari" ritual was investigated. Snakes (n = 112) were examined and ectoparasites collected, as well as blood and feces sampled. Ectoparasites were identified morpho-molecularly, and coprological examination conducted through direct smear and flotation. Molecular screenings were performed to identify parasites and microorganisms in collected samples (i.e., Mesostigmata mites, Anaplasma/Ehrlichia spp., Rickettsia spp., Borrelia burgdorferi sensu lato, Coxiella burnetii, Babesia/Theileria spp., Cryptosporidium spp., Giardia spp., Leishmania spp. and helminths). Overall, 28.5% (32/112) of snakes were molecularly positive for at least one parasite and/or microorganism. Endosymbiont Wolbachia bacteria were identified from Macronyssidae mites and zoonotic vector-borne bacteria (e.g., Rickettsia, Leishmania), as well as orally transmitted pathogens (i.e., Cryptosporidium, Giardia, Proteus vulgaris, Pseudomonas), were detected from blood and feces. Thus, given the central role of the snakes in the tradition of Cocullo, surveys of their parasitic fauna and associated zoonotic pathogens may aid to generate conservation policies to benefit the human-snake interactions, whilst preserving the cultural patrimony of this event.}, }
@article {pmid38376262, year = {2024}, author = {Šibanc, N and Clark, DR and Helgason, T and Dumbrell, AJ and Maček, I}, title = {Extreme environments simplify reassembly of communities of arbuscular mycorrhizal fungi.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0133123}, doi = {10.1128/msystems.01331-23}, pmid = {38376262}, issn = {2379-5077}, abstract = {The ecological impacts of long-term (press) disturbance on mechanisms regulating the relative abundance (i.e., commonness or rarity) and temporal dynamics of species within a community remain largely unknown. This is particularly true for the functionally important arbuscular mycorrhizal (AM) fungi; obligate plant-root endosymbionts that colonize more than two-thirds of terrestrial plant species. Here, we use high-resolution amplicon sequencing to examine how AM fungal communities in a specific extreme ecosystem-mofettes or natural CO2 springs caused by geological CO2 exhalations-are affected by long-term stress. We found that in mofettes, specific and temporally stable communities form as a subset of the local metacommunity. These communities are less diverse and dominated by adapted, "stress tolerant" taxa. Those taxa are rare in control locations and more benign environments worldwide, but show a stable temporal pattern in the extreme sites, consistently dominating the communities in grassland mofettes. This pattern of lower diversity and high dominance of specific taxa has been confirmed as relatively stable over several sampling years and is independently observed across multiple geographic locations (mofettes in different countries). This study implies that the response of soil microbial community composition to long-term stress is relatively predictable, which can also reflect the community response to other anthropogenic stressors (e.g., heavy metal pollution or land use change). Moreover, as AM fungi are functionally differentiated, with different taxa providing different benefits to host plants, changes in community structure in response to long-term environmental change have the potential to impact terrestrial plant communities and their productivity.IMPORTANCEArbuscular mycorrhizal (AM) fungi form symbiotic relationships with more than two-thirds of plant species. In return for using plant carbon as their sole energy source, AM fungi improve plant mineral supply, water balance, and protection against pathogens. This work demonstrates the importance of long-term experiments to understand the effects of long-term environmental change and long-term disturbance on terrestrial ecosystems. We demonstrated a consistent response of the AM fungal community to a long-term stress, with lower diversity and a less variable AM fungal community over time under stress conditions compared to the surrounding controls. We have also identified, for the first time, a suite of AM fungal taxa that are consistently observed across broad geographic scales in stressed and anthropogenically heavily influenced ecosystems. This is critical because global environmental change in terrestrial ecosystems requires an integrative approach that considers both above- and below-ground changes and examines patterns over a longer geographic and temporal scale, rather than just single sampling events.}, }
@article {pmid38374896, year = {2024}, author = {Mazel, F and Pitteloud, C and Guisan, A and Pellissier, L}, title = {Contrasted host specificity of gut and endosymbiont bacterial communities in alpine grasshoppers and crickets.}, journal = {ISME communications}, volume = {4}, number = {1}, pages = {ycad013}, pmid = {38374896}, issn = {2730-6151}, abstract = {Bacteria colonize the body of macroorganisms to form associations ranging from parasitic to mutualistic. Endosymbiont and gut symbiont communities are distinct microbiomes whose compositions are influenced by host ecology and evolution. Although the composition of horizontally acquired symbiont communities can correlate to host species identity (i.e. harbor host specificity) and host phylogeny (i.e. harbor phylosymbiosis), we hypothesize that the microbiota structure of vertically inherited symbionts (e.g. endosymbionts like Wolbachia) is more strongly associated with the host species identity and phylogeny than horizontally acquired symbionts (e.g. most gut symbionts). Here, using 16S metabarcoding on 336 guts from 24 orthopteran species (grasshoppers and crickets) in the Alps, we observed that microbiota correlated to host species identity, i.e. hosts from the same species had more similar microbiota than hosts from different species. This effect was ~5 times stronger for endosymbionts than for putative gut symbionts. Although elevation correlated with microbiome composition, we did not detect phylosymbiosis for endosymbionts and putative gut symbionts: closely related host species did not harbor more similar microbiota than distantly related species. Our findings indicate that gut microbiota of studied orthopteran species is more correlated to host identity and habitat than to the host phylogeny. The higher host specificity in endosymbionts corroborates the idea that-everything else being equal-vertically transmitted microbes harbor stronger host specificity signal, but the absence of phylosymbiosis suggests that host specificity changes quickly on evolutionary time scales.}, }
@article {pmid38371935, year = {2024}, author = {Thimmappa, BC and Salhi, LN and Forget, L and Sarrasin, M and Bustamante Villalobos, P and Henrissat, B and Lang, BF and Burger, G}, title = {A biofertilizing fungal endophyte of cranberry plants suppresses the plant pathogen Diaporthe.}, journal = {Frontiers in microbiology}, volume = {15}, number = {}, pages = {1327392}, pmid = {38371935}, issn = {1664-302X}, abstract = {Fungi colonizing plants are gaining attention because of their ability to promote plant growth and suppress pathogens. While most studies focus on endosymbionts from grasses and legumes, the large and diverse group of ericaceous plants has been much neglected. We recently described one of the very few fungal endophytes promoting the growth of the Ericaceae Vaccinium macrocarpon (American cranberry), notably the Codinaeella isolate EC4. Here, we show that EC4 also suppresses fungal pathogens, which makes it a promising endophyte for sustainable cranberry cultivation. By dual-culture assays on agar plates, we tested the potential growth suppression (or biocontrol) of EC4 on other microbes, notably 12 pathogenic fungi and one oomycete reported to infect not only cranberry but also blueberry, strawberry, tomato plants, rose bushes and olive trees. Under greenhouse conditions, EC4 protects cranberry plantlets infected with one of the most notorious cranberry-plant pathogens, Diaporthe vaccinii, known to cause upright dieback and berry rot. The nuclear genome sequence of EC4 revealed a large arsenal of genes potentially involved in biocontrol. About ∼60 distinct clusters of genes are homologs of secondary metabolite gene clusters, some of which were shown in other fungi to synthesize nonribosomal peptides and polyketides, but in most cases, the exact compounds these clusters may produce are unknown. The EC4 genome also encodes numerous homologs of hydrolytic enzymes known to degrade fungal cell walls. About half of the nearly 250 distinct glucanases and chitinases are likely involved in biocontrol because they are predicted to be secreted outside the cell. Transcriptome analysis shows that the expression of about a quarter of the predicted secondary-metabolite gene clusters and glucan and chitin-degrading genes of EC4 is stimulated when it is co-cultured with D. vaccinii. Some of the differentially expressed EC4 genes are alternatively spliced exclusively in the presence of the pathogen, altering the proteins' domain content and subcellular localization signal, thus adding a second level of proteome adaptation in response to habitat competition. To our knowledge, this is the first report of Diaporthe-induced alternative splicing of biocontrol genes.}, }
@article {pmid38366251, year = {2024}, author = {Gimmi, E and Vorburger, C}, title = {High specificity of symbiont-conferred resistance in an aphid-parasitoid field community.}, journal = {Journal of evolutionary biology}, volume = {37}, number = {2}, pages = {162-170}, doi = {10.1093/jeb/voad013}, pmid = {38366251}, issn = {1420-9101}, support = {31003A_181969/SNSF_/Swiss National Science Foundation/Switzerland ; }, mesh = {Animals ; *Aphids/genetics/microbiology ; *Wasps/genetics ; Host-Parasite Interactions/genetics ; Symbiosis ; Enterobacteriaceae ; }, abstract = {Host-parasite coevolution is mediated by genetic interactions between the antagonists and may lead to reciprocal adaptation. In the black bean aphid, Aphis fabae fabae, resistance to parasitoids can be conferred by the heritable bacterial endosymbiont Hamiltonella defensa. H. defensa has been shown to be variably protective against different parasitoid species, and different genotypes of the black bean aphid's main parasitoid Lysiphlebus fabarum. However, these results were obtained using haphazard combinations of laboratory-reared insect lines with different origins, making it unclear how representative they are of natural, locally (co)adapted communities. We therefore comprehensively sampled the parasitoids of a natural A. f. fabae population and measured the ability of the five most abundant species to parasitize aphids carrying the locally prevalent H. defensa haplotypes. H. defensa provided resistance only against the dominant parasitoid L. fabarum (70% of all parasitoids), but not against less abundant parasitoids, and resistance to L. fabarum acted in a genotype-specific manner (G × G interactions between H. defensa and L. fabarum). These results confirm that strong species- and genotype-specificity of symbiont-conferred resistance is indeed a hallmark of wild A. f. fabae populations, and they are consistent with symbiont-mediated adaptation of aphids to the parasitoids posing the highest risk.}, }
@article {pmid38365237, year = {2024}, author = {Zhang, H and Hellweger, FL and Luo, H}, title = {Genome reduction occurred in early Prochlorococcus with an unusually low effective population size.}, journal = {The ISME journal}, volume = {18}, number = {1}, pages = {}, doi = {10.1093/ismejo/wrad035}, pmid = {38365237}, issn = {1751-7370}, support = {14110820//Hong Kong Research Grants Council General Research Fund/ ; MCEF21101//Marine Conservation Enhancement Fund/ ; AoE/M-403/16//Hong Kong Research Grants Council Area of Excellence Scheme/ ; 4053605//Chinese University of Hong Kong/ ; 2022A1515010844//Guangdong Basic and Applied Basic Research Foundation/ ; 2021M702296//China Postdoctoral Science Foundation/ ; }, abstract = {In the oligotrophic sunlit ocean, the most abundant free-living planktonic bacterial lineages evolve convergently through genome reduction. The cyanobacterium Prochlorococcus responsible for 10% global oxygen production is a prominent example. The dominant theory known as "genome streamlining" posits that they have extremely large effective population sizes (Ne) such that selection for metabolic efficiency acts to drive genome reduction. Because genome reduction largely took place anciently, this theory builds on the assumption that their ancestors' Ne was similarly large. Constraining Ne for ancient ancestors is challenging because experimental measurements of extinct organisms are impossible and alternatively reconstructing ancestral Ne with phylogenetic models gives large uncertainties. Here, we develop a new strategy that leverages agent-based modeling to simulate the changes in the genome-wide ratio of radical to conservative nonsynonymous nucleotide substitution rate (dR/dC) in a possible range of Ne in ancestral populations. This proxy shows expected increases with decreases of Ne only when Ne falls to about 10 k - 100 k or lower, magnitudes characteristic of Ne of obligate endosymbiont species where drift drives genome reduction. Our simulations therefore strongly support a scenario where the primary force of Prochlorococcus genome reduction is drift rather than selection.}, }
@article {pmid38351312, year = {2024}, author = {Goodbody-Gringley, G and Martinez, S and Bellworthy, J and Chequer, A and Nativ, H and Mass, T}, title = {Irradiance driven trophic plasticity in the coral Madracis pharensis from the Eastern Mediterranean.}, journal = {Scientific reports}, volume = {14}, number = {1}, pages = {3646}, pmid = {38351312}, issn = {2045-2322}, support = {1937770//National Science Foundation (NSF)/ ; 2019653//United States - Israel Binational Science Foundation (BSF)/ ; }, mesh = {Animals ; *Anthozoa/physiology ; Photosynthesis ; Heterotrophic Processes ; Symbiosis/physiology ; Israel ; Coral Reefs ; }, abstract = {The distribution of symbiotic scleractinian corals is driven, in part, by light availability, as host energy demands are partially met through translocation of photosynthate. Physiological plasticity in response to environmental conditions, such as light, enables the expansion of resilient phenotypes in the face of changing environmental conditions. Here we compared the physiology, morphology, and taxonomy of the host and endosymbionts of individual Madracis pharensis corals exposed to dramatically different light conditions based on colony orientation on the surface of a shipwreck at 30 m depth in the Bay of Haifa, Israel. We found significant differences in symbiont species consortia, photophysiology, and stable isotopes, suggesting that these corals can adjust multiple aspects of host and symbiont physiology in response to light availability. These results highlight the potential of corals to switch to a predominantly heterotrophic diet when light availability and/or symbiont densities are too low to sustain sufficient photosynthesis, which may provide resilience for corals in the face of climate change.}, }
@article {pmid38349547, year = {2024}, author = {Kumar, MPS and Keerthana, A and Priya,  and Singh, SK and Rai, D and Jaiswal, A and Reddy, MSS}, title = {Exploration of culturable bacterial associates of aphids and their interactions with entomopathogens.}, journal = {Archives of microbiology}, volume = {206}, number = {3}, pages = {96}, pmid = {38349547}, issn = {1432-072X}, abstract = {Aphids shelter several bacteria that benefit them in various ways. The associates having an obligatory relationship are non-culturable, while a few of facultative associates are culturable in insect cell lines, axenic media or standard microbiology media. In the present investigation, isolation, and characterization of the culturable bacterial associates of various aphid species, viz., Rhopalosiphum maidis, Rhopalosiphum padi, Sitobion avenae, Schizaphis graminum, and Lipaphis erysimi pseudobrassicae were carried out. A total of 42 isolates were isolated using different growth media, followed by their morphological, biochemical, and molecular characterization. The isolated culturable bacterial associates were found to belong to the genera Acinetobacter, Bacillus, Brevundimonas, Cytobacillus, Fictibacillus, Planococcus, Priestia, Pseudomonas, Staphylococcus, Sutcliffiella, and Tumebacillus which were grouped under seven families of four different orders of phyla Bacillota (Firmicutes) and Pseudomonata (Proteobacteria). Symbiont-entomopathogen interaction study was also conducted, in which the quantification of colony forming units of culturable bacterial associates of entomopathogenic fungal-treated aphids led us to the assumption that the bacterial load in aphid body can be altered by the application of entomopathogens. Whereas, the mycelial growth of entomopathogens Akanthomyces lecanii and Metarhizium anisopliae was found uninhibited by the bacterial associates obtained from Sitobion avenae and Rhopalosiphum padi. Analyzing persistent aphid microflora and their interactions with entomopathogens enhances our understanding of aphid resistance. It also fosters the development of innovative solutions for agricultural pest management, highlighting the intricate dynamics of symbiotic relationships in pest management strategies.}, }
@article {pmid38346575, year = {2024}, author = {Garrido-Bautista, J and Cláudia Norte, A and Moreno-Rueda, G and Nadal-Jiménez, P}, title = {Ecological determinants of prevalence of the male-killing bacterium Arsenophonus nasoniae.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {108073}, doi = {10.1016/j.jip.2024.108073}, pmid = {38346575}, issn = {1096-0805}, abstract = {Male-killing bacteria are found in a broad range of arthropods. Arsenophonus nasoniae is a male-killing bacterium, causing a 80% reduction of the male progeny in infected Nasonia vitripennis wasps. Although the discovery of A. nasoniae dates from the early 80's, knowledge about the biology and ecology of this endosymbiont is still scarce. One of these poorly studied features is the ecological factors underlying A. nasoniae incidence on its Nasonia spp. hosts in different geographical locations. Here, we studied the prevalence of A. nasoniae in Iberian wild populations of its host N. vitripennis. This wasp species is a common parasitoid of the blowfly Protocalliphora azurea pupae, which in turn is a parasite of hole-nesting birds, such as the blue tit (Cyanistes caeruleus). We also examined the effects of bird rearing conditions on the prevalence of A. nasoniae through a brood size manipulation experiment (creating enlarged, control and reduced broods). Both the wasp and bacterium presence were tested through PCR assays in blowfly pupae. We found A. nasoniae in almost half (47%) of nests containing blowflies parasitized by N. vitripennis. The prevalence of A. nasoniae was similar in the two geographical areas examined (central Portugal and southeastern Spain) and the probability of infection by A. nasoniae was independent of the number of blowfly pupae in the nest. Experimental manipulation of brood size did not affect the prevalence of A. nasoniae nor the prevalence of its host, N. vitripennis. These results suggest that the incidence of A. nasoniae in natural populations of N. vitripennis is high in the Iberian Peninsula, and the infestation frequency of nests by N. vitripennis carrying A. nasoniae is spatially stable in this geographical region independently of bird rearing conditions.}, }
@article {pmid38334408, year = {2024}, author = {Wang, R and Meng, Q and Wang, X and Xiao, Y and Sun, R and Zhang, Z and Fu, Y and Di Giuseppe, G and Liang, A}, title = {Comparative genomic analysis of symbiotic and free-living Fluviibacter phosphoraccumulans strains provides insights into the evolutionary origins of obligate Euplotes-bacterial endosymbioses.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0190023}, doi = {10.1128/aem.01900-23}, pmid = {38334408}, issn = {1098-5336}, abstract = {Endosymbiosis is a widespread and important phenomenon requiring diverse model systems. Ciliates are a widespread group of protists that often form symbioses with diverse microorganisms. Endosymbioses between the ciliate Euplotes and heritable bacterial symbionts are common in nature, and four essential symbionts were described: Polynucleobacter necessarius, "Candidatus Protistobacter heckmanni," "Ca. Devosia symbiotica," and "Ca. Devosia euplotis." Among them, only the genus Polynucleobacter comprises very close free-living and symbiotic representatives, which makes it an excellent model for investigating symbiont replacements and recent symbioses. In this article, we characterized a novel endosymbiont inhabiting the cytoplasm of Euplotes octocarinatus and found that it is a close relative of the free-living bacterium Fluviibacter phosphoraccumulans (Betaproteobacteria and Rhodocyclales). We present the complete genome sequence and annotation of the symbiotic Fluviibacter. Comparative analyses indicate that the genome of symbiotic Fluviibacter is small in size and rich in pseudogenes when compared with free-living strains, which seems to fit the prediction for recently established endosymbionts undergoing genome erosion. Further comparative analysis revealed reduced metabolic capacities in symbiotic Fluviibacter, which implies that the symbiont relies on the host Euplotes for carbon sources, organic nitrogen and sulfur, and some cofactors. We also estimated substitution rates between symbiotic and free-living Fluviibacter pairs for 233 genes; the results showed that symbiotic Fluviibacter displays higher dN/dS mean value than free-living relatives, which suggested that genetic drift is the main driving force behind molecular evolution in endosymbionts.IMPORTANCEIn the long history of symbiosis research, most studies focused mainly on organelles or bacteria within multicellular hosts. The single-celled protists receive little attention despite harboring an immense diversity of symbiotic associations with bacteria and archaea. One subgroup of the ciliate Euplotes species is strictly dependent on essential symbionts for survival and has emerged as a valuable model for understanding symbiont replacements and recent symbioses. However, almost all of our knowledge about the evolution and functions of Euplotes symbioses comes from the Euplotes-Polynucleobacter system. In this article, we report a novel essential symbiont, which also has very close free-living relatives. Genome analysis indicated that it is a recently established endosymbiont undergoing genome erosion and relies on the Euplotes host for many essential molecules. Our results provide support for the notion that essential symbionts of the ciliate Euplotes evolve from free-living progenitors in the natural water environment.}, }
@article {pmid38326788, year = {2024}, author = {Burger, NFV and Nicolis, VF and Botha, AM}, title = {Host-specific co-evolution likely driven by diet in Buchnera aphidicola.}, journal = {BMC genomics}, volume = {25}, number = {1}, pages = {153}, pmid = {38326788}, issn = {1471-2164}, support = {CSRU180414320893//National Research Foundation, South Africa/ ; WCT/W/2001/02//South African Winter Cereal Industry Trust/ ; }, mesh = {Animals ; *Buchnera/genetics/metabolism ; Escherichia coli ; *Aphids/genetics/metabolism ; Gene Expression Regulation ; Diet ; Symbiosis/genetics ; }, abstract = {BACKGROUND: Russian wheat aphid (Diuraphis noxia Kurd.) is a severe pest to wheat, and even though resistance varieties are available to curb this pest, they are becoming obsolete with the development of new virulent aphid populations. Unlike many other aphids, D noxia only harbours a single endosymbiont, Buchnera aphidicola. Considering the importance of Buchnera, this study aimed to elucidate commonalities and dissimilarities between various hosts, to better understand its distinctiveness within its symbiotic relationship with D. noxia. To do so, the genome of the D. noxia's Buchnera was assembled and compared to those of other aphid species that feed on diverse host species.<br><br>RESULTS: The overall importance of several features such as gene length and percentage GC content was found to be critical for the maintenance of Buchnera genes when compared to their closest free-living relative, Escherichia coli. Buchnera protein coding genes were found to have percentage GC contents that tended towards a mean of&#x2009;~&#x2009;26% which had strong correlation to their identity to their E. coli homologs. Several SNPs were identified between different aphid populations and multiple isolates of Buchnera were confirmed in single aphids.<br><br>CONCLUSIONS: Establishing the strong correlation of percentage GC content of protein coding genes and gene identity will allow for identifying which genes will be lost in the continually shrinking Buchnera genome. This is also the first report of a parthenogenically reproducing aphid that hosts multiple Buchnera strains in a single aphid, raising questions regarding the benefits of maintaining multiple strains. We also found preliminary evidence for post-transcriptional regulation of Buchnera genes in the form of polyadenylation.}, }
@article {pmid38325049, year = {2024}, author = {Hollender, M and Sałek, M and Karlicki, M and Karnkowska, A}, title = {Single-cell genomics revealed Candidatus Grellia alia sp. nov. as an endosymbiont of Eutreptiella sp. (Euglenophyceae).}, journal = {Protist}, volume = {175}, number = {2}, pages = {126018}, doi = {10.1016/j.protis.2024.126018}, pmid = {38325049}, issn = {1618-0941}, abstract = {Though endosymbioses between protists and prokaryotes are widespread, certain host lineages have received disproportionate attention what may indicate either a predisposition to such interactions or limited studies on certain protist groups due to lack of cultures. The euglenids represent one such group in spite of microscopic observations showing intracellular bacteria in some strains. Here, we perform a comprehensive molecular analysis of a previously identified endosymbiont in the Eutreptiella sp. CCMP3347 using a single cell approach and bulk culture sequencing. The genome reconstruction of this endosymbiont allowed the description of a new endosymbiont Candidatus Grellia alia sp. nov. from the family Midichloriaceae. Comparative genomics revealed a remarkably complete conjugative type IV secretion system present in three copies on the plasmid sequences of the studied endosymbiont, a feature missing in the closely related Grellia incantans. This study addresses the challenge of limited host cultures with endosymbionts by showing that the genomes of endosymbionts reconstructed from single host cells have the completeness and contiguity that matches or exceeds those coming from bulk cultures. This paves the way for further studies of endosymbionts in euglenids and other protist groups. The research also provides the opportunity to study the diversity of endosymbionts in natural populations.}, }
@article {pmid38322002, year = {2024}, author = {Zhai, X and Zhang, Y and Zhou, J and Li, H and Wang, A and Liu, L}, title = {Physiological and microbiome adaptation of coral Turbinaria peltata in response to marine heatwaves.}, journal = {Ecology and evolution}, volume = {14}, number = {2}, pages = {e10869}, doi = {10.1002/ece3.10869}, pmid = {38322002}, issn = {2045-7758}, abstract = {Against the backdrop of global warming, marine heatwaves are projected to become increasingly intense and frequent. This trend poses a potential threat to the survival of corals and the maintenance of entire coral reef ecosystems. Despite extensive evidence for the resilience of corals to heat stress, their ability to withstand repeated heatwave events has not been determined. In this study, we examined the responses and resilience of Turbinaria peltata to repeated exposure to marine heatwaves, with a focus on physiological parameters and symbiotic microorganisms. In the first heatwave, from a physiological perspective, T. peltata showed decreases in the Chl a content and endosymbiont density and significant increases in GST, caspase-3, CAT, and SOD levels (p < .05), while the effects of repeated exposure on heatwaves were weaker than those of the initial exposure. In terms of bacteria, the abundance of Leptospira, with the potential for pathogenicity and intracellular parasitism, increased significantly during the initial exposure. Beneficial bacteria, such as Achromobacter arsenitoxydans and Halomonas desiderata increased significantly during re-exposure to the heatwave. Overall, these results indicate that T. peltata might adapt to marine heatwaves through physiological regulation and microbial community alterations.}, }
@article {pmid38318130, year = {2023}, author = {Koga, R and Moriyama, M and Nozaki, T and Fukatsu, T}, title = {Genome analysis of "Candidatus Aschnera chinzeii," the bacterial endosymbiont of the blood-sucking bat fly Penicillidia jenynsii (Insecta: Diptera: Nycteribiidae).}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1336919}, pmid = {38318130}, issn = {1664-302X}, abstract = {Insect-microbe endosymbiotic associations are omnipresent in nature, wherein the symbiotic microbes often play pivotal biological roles for their host insects. In particular, insects utilizing nutritionally imbalanced food sources are dependent on specific microbial symbionts to compensate for the nutritional deficiency via provisioning of B vitamins in blood-feeding insects, such as tsetse flies, lice, and bedbugs. Bat flies of the family Nycteribiidae (Diptera) are blood-sucking ectoparasites of bats and shown to be associated with co-speciating bacterial endosymbiont "Candidatus Aschnera chinzeii," although functional aspects of the microbial symbiosis have been totally unknown. In this study, we report the first complete genome sequence of Aschnera from the bristled bat fly Penicillidia jenynsii. The Aschnera genome consisted of a 748,020 bp circular chromosome and a 18,747 bp circular plasmid. The chromosome encoded 603 protein coding genes (including 3 pseudogenes), 33 transfer RNAs, and 1 copy of 16S/23S/5S ribosomal RNA operon. The plasmid contained 10 protein coding genes, whose biological function was elusive. The genome size, 0.77 Mbp, was drastically reduced in comparison with 4-6 Mbp genomes of free-living γ-proteobacteria. Accordingly, the Aschnera genome was devoid of many important functional genes, such as synthetic pathway genes for purines, pyrimidines, and essential amino acids. On the other hand, the Aschnera genome retained complete or near-complete synthetic pathway genes for biotin (vitamin B7), tetrahydrofolate (vitamin B9), riboflavin (vitamin B2), and pyridoxal 5'-phosphate (vitamin B6), suggesting that Aschnera provides these vitamins and cofactors that are deficient in the blood meal of the host bat fly. Similar retention patterns of the synthetic pathway genes for vitamins and cofactors were also observed in the endosymbiont genomes of other blood-sucking insects, such as Riesia of human lice, Arsenophonus of louse flies, and Wigglesworthia of tsetse flies, which may be either due to convergent evolution in the blood-sucking host insects or reflecting the genomic architecture of Arsenophonus-allied bacteria.}, }
@article {pmid38315036, year = {2024}, author = {Shi, P-Q and Wang, L and Chen, X-Y and Wang, K and Wu, Q-J and Turlings, TCJ and Zhang, P-J and Qiu, B-L}, title = {Rickettsia transmission from whitefly to plants benefits herbivore insects but is detrimental to fungal and viral pathogens.}, journal = {mBio}, volume = {}, number = {}, pages = {e0244823}, doi = {10.1128/mbio.02448-23}, pmid = {38315036}, issn = {2150-7511}, abstract = {Bacterial endosymbionts play important roles in the life histories of herbivorous insects by impacting their development, survival, reproduction, and stress tolerance. How endosymbionts may affect the interactions between plants and insect herbivores is still largely unclear. Here, we show that endosymbiotic Rickettsia belli can provide mutual benefits also outside of their hosts when the sap-sucking whitefly Bemisia tabaci transmits them to plants. This transmission facilitates the spread of Rickettsia but is shown to also enhance the performance of the whitefly and co-infesting caterpillars. In contrast, Rickettsia infection enhanced plant resistance to several pathogens. Inside the plants, Rickettsia triggers the expression of salicylic acid-related genes and the two pathogen-resistance genes TGA 2.1 and VRP, whereas they repressed genes of the jasmonic acid pathway. Performance experiments using wild type and mutant tomato plants confirmed that Rickettsia enhances the plants' suitability for insect herbivores but makes them more resistant to fungal and viral pathogens. Our results imply that endosymbiotic Rickettsia of phloem-feeding insects affects plant defenses in a manner that facilitates their spread and transmission. This novel insight into how insects can exploit endosymbionts to manipulate plant defenses also opens possibilities to interfere with their ability to do so as a crop protection strategy.IMPORTANCEMost insects are associated with symbiotic bacteria in nature. These symbionts play important roles in the life histories of herbivorous insects by impacting their development, survival, reproduction as well as stress tolerance. Rickettsia is one important symbiont to the agricultural pest whitefly Bemisia tabaci. Here, for the first time, we revealed that the persistence of Rickettsia symbionts in tomato leaves significantly changed the defense pattern of tomato plants. These changes benefit both sap-feeding and leaf-chewing herbivore insects, such as increasing the fecundity of whitefly adults, enhancing the growth and development of the noctuid Spodoptera litura, but reducing the pathogenicity of Verticillium fungi and TYLCV virus to tomato plants distinctively. Our study unraveled a new horizon for the multiple interaction theories among plant-insect-bacterial symbionts.}, }
@article {pmid38309271, year = {2024}, author = {Bastide, H and Legout, H and Dogbo, N and Ogereau, D and Prediger, C and Carcaud, J and Filée, J and Garnery, L and Gilbert, C and Marion-Poll, F and Requier, F and Sandoz, JC and Yassin, A}, title = {The genome of the blind bee louse fly reveals deep convergences with its social host and illuminates Drosophila origins.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2024.01.034}, pmid = {38309271}, issn = {1879-0445}, abstract = {Social insects' nests harbor intruders known as inquilines,[1] which are usually related to their hosts.[2][,][3] However, distant non-social inquilines may also show convergences with their hosts,[4][,][5] although the underlying genomic changes remain unclear. We analyzed the genome of the wingless and blind bee louse fly Braula coeca, an inquiline kleptoparasite of the western honey bee, Apis mellifera.[6][,][7] Using large phylogenomic data, we confirmed recent accounts that the bee louse fly is a drosophilid[8][,][9] and showed that it had likely evolved from a sap-breeder ancestor associated with honeydew and scale insects' wax. Unlike many parasites, the bee louse fly genome did not show significant erosion or strict reliance on an endosymbiont, likely due to a relatively recent age of inquilinism. However, we observed a horizontal transfer of a transposon and a striking parallel evolution in a set of gene families between the honey bee and the bee louse fly. Convergences included genes potentially involved in metabolism and immunity and the loss of nearly all bitter-tasting gustatory receptors, in agreement with life in a protective nest and a diet of honey, pollen, and beeswax. Vision and odorant receptor genes also exhibited rapid losses. Only genes whose orthologs in the closely related Drosophila melanogaster respond to honey bee pheromone components or floral aroma were retained, whereas the losses included orthologous receptors responsive to the anti-ovarian honey bee queen pheromones. Hence, deep genomic convergences can underlie major phenotypic transitions during the evolution of inquilinism between non-social parasites and their social hosts.}, }
@article {pmid38309038, year = {2024}, author = {Manigandan, V and Muthukumar, C and Shah, C and Logesh, N and Sivadas, SK and Ramu, K and Ramana Murthy, MV}, title = {Phylogenetic affiliation of Pedinomonas noctilucae and green Noctiluca scintillans nutritional dynamics in the Gulf of Mannar, Southeastern Arabian Sea.}, journal = {Protist}, volume = {175}, number = {2}, pages = {126019}, doi = {10.1016/j.protis.2024.126019}, pmid = {38309038}, issn = {1618-0941}, abstract = {The present investigation focused on studying the phylogenetic position of the green Noctiluca endosymbiont, Pedinomonas noctilucae, collected from the Gulf of Mannar, India. In this study, we re-examined the evolutionary position of this endosymbiotic algae using rbcL sequences. The phylogenetic analysis revealed that P. noctilucae is distantly related to the Pedinomonas species, and formed a monophyletic clade with Marsupiomandaceae. Based on the phylogenetic association of endosymbiont with Maruspiomonadales it was concluded that the endosymbiont belongs to an independent genus within the family Marsupiomonadaceae. At the site of the bloom, Noctiluca scintillans was found to exhibit a dense monospecific proliferation, with an average cell density of 27.l88 × 10[3] cells L[-1]. The investigation revealed that the green Noctiluca during its senescent phase primarily relied on autotrophic nutrition, which was confirmed by the presence of a high number of trophonts, vegetatively reproducing cells (1.45 × 10[3] cells L[-1]) and the absence of food vacuoles.}, }
@article {pmid38294503, year = {2024}, author = {Pistán, ME and Cook, D and Gutiérrez, SA and Schnittger, L and Gardner, DR and Cholich, LA and Gonzalez, AM}, title = {Identification and distribution of a fungal endosymbiotic Alternaria species (Alternaria section Undifilum sp.) in Astragalus garbancillo tissues.}, journal = {Mycologia}, volume = {}, number = {}, pages = {1-8}, doi = {10.1080/00275514.2023.2299191}, pmid = {38294503}, issn = {1557-2536}, abstract = {Plants belonging to the genera Astragalus, Oxytropis, Ipomoea, Sida, and Swainsona often contain the toxin swainsonine (SW) produced by an associated fungal symbiont. Consumption of SW-containing plants causes a serious neurological disorder in livestock, which can be fatal. In this study, a fungal endophyte, Alternaria section Undifilum, was identified in Astragalus garbancillo seeds, using polymerase chain reaction (PCR) followed by direct sequencing. In seeds, the SW concentrations were about 4 times higher than in other parts of the plant. Furthermore, microscopic examination demonstrated that the fungus mycelium grows inside the petioles and stems, on the outer surface and inside the mesocarp of the fruit, in the mesotesta and endotesta layers of the seed coat, and inside the endosperm of the seeds. Our results support the notion that the SW-producing fungus is vertically transmitted in the host plant A. garbancillo.}, }
@article {pmid38276282, year = {2024}, author = {Domínguez-Santos, R and Baixeras, J and Moya, A and Latorre, A and Gil, R and García-Ferris, C}, title = {Gut Microbiota Is Not Essential for Survival and Development in Blattella germanica, but Affects Uric Acid Storage.}, journal = {Life (Basel, Switzerland)}, volume = {14}, number = {1}, pages = {}, pmid = {38276282}, issn = {2075-1729}, support = {PGC2018-099344-B-I00//MCIN/AEI/10.13039/501100011033 and "ERDF A way of making Europe"/ ; PID2021-128201NB-I00//MCIN/AEI/10.13039/501100011033 and "ERDF A way of making Europe"/ ; PROMETEO/2018/133//Conselleria d'Educaci&#xf3;, Generalitat Valenciana (Spain)/ ; CIPROM/2021/042//Conselleria d'Educaci&#xf3;, Generalitat Valenciana (Spain)/ ; }, abstract = {Cockroaches harbor two coexisting symbiotic systems: the obligate endosymbiont Blattabacterium cuenotii, and a complex gut microbiota. Blattabacterium is the only bacterium present in the eggs, as the gut microbiota is acquired by horizontal transmission after hatching, mostly through coprophagy. Blattella germanica, a cosmopolitan omnivorous cockroach living in intimate association with humans, is an appropriate model system for studying whether the gut microbiota is essential for the cockroach's survival, development, or welfare. We obtained a germ-free cockroach population (i.e., containing normal amounts of the endosymbiont, but free of microbes on the insects' surface and digestive tract). Non-significant differences with the controls were detected in most fitness parameters analyzed, except for a slight shortening in the hatching time of the second generation and a reduction in female weight at 10 days after adult ecdysis. The latter is accompanied by a decrease in uric acid reserves. This starvation-like phenotype of germ-free B. germanica suggests that the microbiota is not essential in this species for survival and development throughout its complete life cycle, but it could participate in complementation of host nutrition by helping with food digestion and nutrient absorption.}, }
@article {pmid38276179, year = {2023}, author = {Chirgwin, E and Yang, Q and Umina, PA and Thia, JA and Gill, A and Song, W and Gu, X and Ross, PA and Wei, SJ and Hoffmann, AA}, title = {Barley Yellow Dwarf Virus Influences Its Vector's Endosymbionts but Not Its Thermotolerance.}, journal = {Microorganisms}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/microorganisms12010010}, pmid = {38276179}, issn = {2076-2607}, support = {AGPIP//Grains Research and Development Corporation/ ; }, abstract = {The barley yellow dwarf virus (BYDV) of cereals is thought to substantially increase the high-temperature tolerance of its aphid vector, Rhopalosiphum padi, which may enhance its transmission efficiency. This is based on experiments with North American strains of BYDV and R. padi. Here, we independently test these by measuring the temperature tolerance, via Critical Thermal Maximum (CTmax) and knockdown time, of Australian R. padi infected with a local BYDV isolate. We further consider the interaction between BYDV transmission, the primary endosymbiont of R. padi (Buchnera aphidicola), and a transinfected secondary endosymbiont (Rickettsiella viridis) which reduces the thermotolerance of other aphid species. We failed to find an increase in tolerance to high temperatures in BYDV-infected aphids or an impact of Rickettsiella on thermotolerance. However, BYDV interacted with R. padi endosymbionts in unexpected ways, suppressing the density of Buchnera and Rickettsiella. BYDV density was also fourfold higher in Rickettsiella-infected aphids. Our findings indicate that BYDV does not necessarily increase the temperature tolerance of the aphid transmission vector to increase its transmission potential, at least for the genotype combinations tested here. The interactions between BYDV and Rickettsiella suggest new ways in which aphid endosymbionts may influence how BYDV spreads, which needs further testing in a field context.}, }
@article {pmid38273274, year = {2024}, author = {Butenko, A and Lukeš, J and Speijer, D and Wideman, JG}, title = {Mitochondrial genomes revisited: why do different lineages retain different genes?.}, journal = {BMC biology}, volume = {22}, number = {1}, pages = {15}, pmid = {38273274}, issn = {1741-7007}, support = {DBI-2119963//Division of Biological Infrastructure/ ; 23-07695S//Grantov&#xe1; Agentura &#x10c;esk&#xe9; Republiky/ ; 23-06479X//Grantov&#xe1; Agentura &#x10c;esk&#xe9; Republiky/ ; }, abstract = {The mitochondria contain their own genome derived from an alphaproteobacterial endosymbiont. From thousands of protein-coding genes originally encoded by their ancestor, only between 1 and about 70 are encoded on extant mitochondrial genomes (mitogenomes). Thanks to a dramatically increasing number of sequenced and annotated mitogenomes a coherent picture of why some genes were lost, or relocated to the nucleus, is emerging. In this review, we describe the characteristics of mitochondria-to-nucleus gene transfer and the resulting varied content of mitogenomes across eukaryotes. We introduce a 'burst-upon-drift' model to best explain nuclear-mitochondrial population genetics with flares of transfer due to genetic drift.}, }
@article {pmid38271524, year = {2024}, author = {Ivanov, S and Harrison, MJ}, title = {Receptor-associated kinases control the lipid provisioning program in plant-fungal symbiosis.}, journal = {Science (New York, N.Y.)}, volume = {383}, number = {6681}, pages = {443-448}, doi = {10.1126/science.ade1124}, pmid = {38271524}, issn = {1095-9203}, abstract = {The mutualistic association between plants and arbuscular mycorrhizal (AM) fungi requires intracellular accommodation of the fungal symbiont and maintenance by means of lipid provisioning. Symbiosis signaling through lysin motif (LysM) receptor-like kinases and a leucine-rich repeat receptor-like kinase DOES NOT MAKE INFECTIONS 2 (DMI2) activates transcriptional programs that underlie fungal passage through the epidermis and accommodation in cortical cells. We show that two Medicago truncatula cortical cell-specific, membrane-bound proteins of a CYCLIN-DEPENDENT KINASE-LIKE (CKL) family associate with, and are phosphorylation substrates of, DMI2 and a subset of the LysM receptor kinases. CKL1 and CKL2 are required for AM symbiosis and control expression of transcription factors that regulate part of the lipid provisioning program. Onset of lipid provisioning is coupled with arbuscule branching and with the REDUCED ARBUSCULAR MYCORRHIZA 1 (RAM1) regulon for complete endosymbiont accommodation.}, }
@article {pmid38265715, year = {2024}, author = {Tomás-Gallardo, L and Cabrera, JJ and Mesa, S}, title = {Surface Plasmon Resonance as a Tool to Elucidate the Molecular Determinants of Key Transcriptional Regulators Controlling Rhizobial Lifestyles.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2751}, number = {}, pages = {145-163}, pmid = {38265715}, issn = {1940-6029}, mesh = {Humans ; *Rhizobium ; Surface Plasmon Resonance ; Oxygen ; DNA ; Transcription Factors ; }, abstract = {Bacteria must be provided with a battery of tools integrated into regulatory networks, in order to respond and, consequently, adapt their physiology to changing environments. Within these networks, transcription factors finely orchestrate the expression of genes in response to a variety of signals, by recognizing specific DNA sequences at their promoter regions. Rhizobia are host-interacting soil bacteria that face severe changes to adapt their physiology from free-living conditions to the nitrogen-fixing endosymbiotic state inside root nodules associated with leguminous plants. One of these cues is the low partial pressure of oxygen within root nodules.Surface plasmon resonance (SPR) constitutes a technique that allows to measure molecular interactions dynamics at real time by detecting changes in the refractive index of a surface. Here, we implemented the SPR methodology to analyze the discriminatory determinants of transcription factors for specific interaction with their target genes. We focused on FixK2, a CRP/FNR-type protein with a central role in the complex oxygen-responsive regulatory network in the soybean endosymbiont Bradyrhizobium diazoefficiens. Our study unveiled relevant residues for protein-DNA interaction as well as allowed us to monitor kinetics and stability protein-DNA complex. We believe that this approach can be employed for the characterization of other relevant transcription factors which can assist to the better understanding of the adaptation of bacteria with agronomic or human interest to their different modes of life.}, }
@article {pmid38259912, year = {2023}, author = {Chen, J}, title = {Editorial: Aphids as plant pests: from biology to green control technology.}, journal = {Frontiers in plant science}, volume = {14}, number = {}, pages = {1337558}, pmid = {38259912}, issn = {1664-462X}, }
@article {pmid38257926, year = {2024}, author = {Jia, J and Lu, SE}, title = {Comparative Genome Analyses Provide Insight into the Antimicrobial Activity of Endophytic Burkholderia.}, journal = {Microorganisms}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/microorganisms12010100}, pmid = {38257926}, issn = {2076-2607}, support = {MIS-401260//United States Department of Agriculture/ ; }, abstract = {Endophytic bacteria are endosymbionts that colonize a portion of plants without harming the plant for at least a part of its life cycle. Bacterial endophytes play an essential role in promoting plant growth using multiple mechanisms. The genus Burkholderia is an important member among endophytes and encompasses bacterial species with high genetic versatility and adaptability. In this study, the endophytic characteristics of Burkholderia species are investigated via comparative genomic analyses of several endophytic Burkholderia strains with pathogenic Burkholderia strains. A group of bacterial genes was identified and predicted as the putative endophytic behavior genes of Burkholderia. Multiple antimicrobial biosynthesis genes were observed in these endophytic bacteria; however, certain important pathogenic and virulence genes were absent. The majority of resistome genes were distributed relatively evenly among the endophytic and pathogenic bacteria. All known types of secretion systems were found in the studied bacteria. This includes T3SS and T4SS, which were previously thought to be disproportionately represented in endophytes. Additionally, questionable CRISPR-Cas systems with an orphan CRISPR array were prevalent, suggesting that intact CRISPR-Cas systems may not exist in symbiotes of Burkholderia. This research not only sheds light on the antimicrobial activities that contribute to biocontrol but also expands our understanding of genomic variations in Burkholderia's endophytic and pathogenic bacteria.}, }
@article {pmid38249471, year = {2023}, author = {Chang, X and Xue, S and Li, R and Zhang, Y}, title = {Episyrphus balteatus symbiont variation across developmental stages, living states, two sexes, and potential horizontal transmission from prey or environment.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1308393}, pmid = {38249471}, issn = {1664-302X}, abstract = {INTRODUCTION: Episyrphus balteatus is one representative Syrphidae insect which can provide extensive pollination and pest control services. To date, the symbiont composition and potential acquisition approaches in Syrphidae remain unclear.<br><br>METHODS: Herein, we investigated microbiota dynamics across developmental stages, different living states, and two sexes in E. balteatus via full-length 16S rRNA genes sequencing, followed by an attempt to explore the possibility of symbiont transmission from prey Megoura crassicauda to the hoverfly.<br><br>RESULTS: Overall, Proteobacteria and Firmicutes were the dominant bacteria phyla with fluctuating relative abundances across the life stage. Cosenzaea myxofaciens is dominant in adulthood, while Enterococcus silesiacus and Morganella morganii dominate in larvae and pupae of E. balteatus, respectively. Unexpectedly, Serratia symbiotica, one facultative endosymbiont commonly harbored in aphids, was one of the predominant bacteria in larvae of E. balteatus, just behind Enterococcus silesiacus. In addition, S. symbiotica was also surprisingly most dominated in M. crassicauda aphids (92.1% relative abundance), which are significantly higher than Buchnera aphidicola (4.7% relative abundance), the primary obligate symbiont of most aphid species. Approximately 25% mortality was observed among newly emerged adults, of which microbiota was also disordered, similar to normally dying individuals. Sexually biased symbionts and 41 bacteria species with pairwise co-occurrence in E. balteatus and 23 biomarker species for each group were identified eventually. Functional prediction showed symbionts of hoverflies and aphids, both mainly focusing on metabolic pathways. In brief, we comprehensively explored the microbiome in one Syrphidae hoverfly using E. balteatus reared indoors on M. morganii as the model, revealed its dominated symbiont species, identified sexually biased symbionts, and found an aphid facultative endosymbiont inhabited in the hoverfly. We also found that the dominated symbiotic bacteria in M. crassicauda are S. symbiotica other than Buchnera aphidicola.<br><br>DISCUSSION: Taken together, this study provides new valuable resources about symbionts in hoverflies and prey aphids jointly, which will benefit further exploring the potential roles of microbiota in E. balteatus.}, }
@article {pmid38249041, year = {2024}, author = {Huang, Y and Feng, ZF and Li, F and Hou, YM}, title = {Host-Encoded Aminotransferase Import into the Endosymbiotic Bacteria Nardonella of Red Palm Weevil.}, journal = {Insects}, volume = {15}, number = {1}, pages = {}, doi = {10.3390/insects15010035}, pmid = {38249041}, issn = {2075-4450}, support = {32001972//National Natural Science Foundation of China/ ; 2022J05032//Natural Science Foundation of Fujian Province/ ; }, abstract = {Symbiotic systems are intimately integrated at multiple levels. Host-endosymbiont metabolic complementarity in amino acid biosynthesis is especially important for sap-feeding insects and their symbionts. In weevil-Nardonella endosymbiosis, the final step reaction of the endosymbiont tyrosine synthesis pathway is complemented by host-encoded aminotransferases. Based on previous results from other insects, we suspected that these aminotransferases were likely transported into the Nardonella cytoplasm to produce tyrosine. Here, we identified five aminotransferase genes in the genome of the red palm weevil. Using quantitative real-time RT-PCR, we confirmed that RfGOT1 and RfGOT2A were specifically expressed in the bacteriome. RNA interference targeting these two aminotransferase genes reduced the tyrosine level in the bacteriome. The immunofluorescence-FISH double labeling localization analysis revealed that RfGOT1 and RfGOT2A were present within the bacteriocyte, where they colocalized with Nardonella cells. Immunogold transmission electron microscopy demonstrated the localization of RfGOT1 and RfGOT2A in the cytosol of Nardonella and the bacteriocyte. Our data revealed that RfGOT1 and RfGOT2A are transported into the Nardonella cytoplasm to collaborate with genes retained in the Nardonella genome in order to synthesize tyrosine. The results of our study will enhance the understanding of the integration of host and endosymbiont metabolism in amino acid biosynthesis.}, }
@article {pmid38232706, year = {2024}, author = {Schott, D and Ribeiro, FL and Santos, FN and Carvalho, RW}, title = {Fleas (Siphonaptera, Latreille, 1825) from Rio Grande do Sul State, Brazil: Species Diversity, Hosts, and One Health Approach.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {}, number = {}, pages = {}, doi = {10.1089/vbz.2023.0065}, pmid = {38232706}, issn = {1557-7759}, abstract = {Background: Fleas are ectoparasitic insects with holometabolous development. It has a hematophagous habit with mouthparts adapted to sting and suck its hosts. There are about 3000 species in the world, ∼61 in Brazil, and 19 in Rio Grande do Sul state. The objective of the research is to catalog the diversity of fleas recorded in the state, their respective hosts, and endosymbionts. Materials and Methods: To this end, a search was carried out in the scientific literature, from articles, books, to abstracts submitted to congresses. Results: The 19 species of fleas occurring in Rio Grande do Sul are divided into 7 families and 10 genera. These ectoparasites, in addition to being found in the environment, were associated with 10 different families of hosts in Rio Grande do Sul, and on the endosymbiont, agents found associated with fleas, there were 7 different species. The main agents researched in the state are Rickettsia spp. and Bartonella spp. The relationships between parasites, hosts, environment, and etiological agents present different scenarios, whether anthropized or conserved, but unknown. Sometimes, this overlap, a factor that aggravates the possibility of spillovers, either from cosmopolitan fleas in these conserved areas, or from their endosymbionts. Conclusion: Thus, it is important to characterize the environment so that the complexities of each location are known for the adoption of environmental and public health policies in each case. The challenges are extensive, but necessary in view of the One Health perspective.}, }
@article {pmid38206026, year = {2024}, author = {Spencer, N and Santee, M and Wetherhold, A and Rio, RVM}, title = {Draft genome sequence of Wigglesworthia glossinidia "palpalis gambiensis" isolate.}, journal = {Microbiology resource announcements}, volume = {}, number = {}, pages = {e0091223}, doi = {10.1128/mra.00912-23}, pmid = {38206026}, issn = {2576-098X}, abstract = {The 0.719 Mb genome of the tsetse endosymbiont, Wigglesworthia glossinidia, from Glossina palpalis gambiensis is presented. This Wigglesworthia genome retains 611 protein-coding sequences and a 25.3% GC content. A cryptic plasmid is conserved, between Wigglesworthia isolates, suggesting functional significance. This genome adds a further dimension to characterize Wigglesworthia lineage-based differences.}, }
@article {pmid38204789, year = {2024}, author = {Arai, H and Watada, M and Kageyama, D}, title = {Two male-killing Wolbachia from Drosophila birauraia that are closely related but distinct in genome structure.}, journal = {Royal Society open science}, volume = {11}, number = {1}, pages = {231502}, pmid = {38204789}, issn = {2054-5703}, abstract = {Insects harbour diverse maternally inherited bacteria and viruses, some of which have evolved to kill the male progeny of their hosts (male killing: MK). The fly species Drosophila biauraria carries a maternally transmitted MK-inducing partiti-like virus, but it was unknown if it carries other MK-inducing endosymbionts. Here, we identified two male-killing Wolbachia strains (wBiau1 and wBiau2) from D. biauraria and compared their genomes to elucidate their evolutionary processes. The two strains were genetically closely related but had exceptionally different genome structures with considerable rearrangements compared with combinations of other Wolbachia strains. Despite substantial changes in the genome structure, the two Wolbachia strains did not experience gene losses that would disrupt the male-killing expression or persistence in the host population. The two Wolbachia-infected matrilines carried distinct mitochondrial haplotypes, suggesting that wBiau1 and wBiau2 have invaded D. biauraria independently and undergone considerable genome changes owing to unknown selective pressures in evolutionary history. This study demonstrated the presence of three male-killers from two distinct origins in one fly species and highlighted the diverse and rapid genome evolution of MK Wolbachia in the host.}, }
@article {pmid38196174, year = {2024}, author = {Wang, ZW and Zhao, J and Li, GY and Hu, D and Wang, ZG and Ye, C and Wang, JJ}, title = {The endosymbiont Serratia symbiotica improves aphid fitness by disrupting the predation strategy of ladybeetle larvae.}, journal = {Insect science}, volume = {}, number = {}, pages = {}, doi = {10.1111/1744-7917.13315}, pmid = {38196174}, issn = {1744-7917}, support = {32102195//National Natural Science Foundation of China/ ; 32020103010//National Natural Science Foundation of China - Major International (Regional) Joint Research Project/ ; CSTB2022NSCQ-MSX0748//Natural Science Foundation of Chongqing, China/ ; SWU-KQ22020//Fundamental Research Funds for the Central Universities of China/ ; }, abstract = {Aphids, the important global agricultural pests, harbor abundant resources of symbionts that can improve the host adaptability to environmental conditions, also control the interactions between host aphid and natural enemy, resulting in a significant decrease in efficiency of biological control. The facultative symbiont Serratia symbiotica has a strong symbiotic association with its aphid hosts, a relationship that is known to interfere with host-parasitoid interactions. We hypothesized that Serratia may also influence other trophic interactions by interfering with the physiology and behavior of major predators to provide host aphid defense. To test this hypothesis, we investigated the effects of Serratia on the host aphid Acyrthosiphon pisum and its predator, the ladybeetle Propylaea japonica. First, the prevalence of Serratia in different A. pisum colonies was confirmed by amplicon sequencing. We then showed that harboring Serratia improved host aphid growth and fecundity but reduced longevity. Finally, our research demonstrated that Serratia defends aphids against P. japonica by impeding the predator's development and predation capacity, and modulating its foraging behavior. Our findings reveal that facultative symbiont Serratia improves aphid fitness by disrupting the predation strategy of ladybeetle larvae, offering new insight into the interactions between aphids and their predators, and providing the basis of a new biological control strategy for aphid pests involving the targeting of endosymbionts.}, }
@article {pmid38195557, year = {2024}, author = {Owens, LA and Friant, S and Martorelli Di Genova, B and Knoll, LJ and Contreras, M and Noya-Alarcon, O and Dominguez-Bello, MG and Goldberg, TL}, title = {VESPA: an optimized protocol for accurate metabarcoding-based characterization of vertebrate eukaryotic endosymbiont and parasite assemblages.}, journal = {Nature communications}, volume = {15}, number = {1}, pages = {402}, pmid = {38195557}, issn = {2041-1723}, support = {1R21AI163592-01//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; 1R01AG049395-01//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; T32AI007414//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; }, abstract = {Protocols for characterizing taxonomic assemblages by deep sequencing of short DNA barcode regions (metabarcoding) have revolutionized our understanding of microbial communities and are standardized for bacteria, archaea, and fungi. Unfortunately, comparable methods for host-associated eukaryotes have lagged due to technical challenges. Despite 54 published studies, issues remain with primer complementarity, off-target amplification, and lack of external validation. Here, we present VESPA (Vertebrate Eukaryotic endoSymbiont and Parasite Analysis) primers and optimized metabarcoding protocol for host-associated eukaryotic community analysis. Using in silico prediction, panel PCR, engineered mock community standards, and clinical samples, we demonstrate VESPA to be more effective at resolving host-associated eukaryotic assemblages than previously published methods and to minimize off-target amplification. When applied to human and non-human primate samples, VESPA enables reconstruction of host-associated eukaryotic endosymbiont communities more accurately and at finer taxonomic resolution than microscopy. VESPA has the potential to advance basic and translational science on vertebrate eukaryotic endosymbiont communities, similar to achievements made for bacterial, archaeal, and fungal microbiomes.}, }
@article {pmid38194362, year = {2024}, author = {Fernandez, HN and Kretsch, AM and Kunakom, S and Kadjo, AE and Mitchell, DA and Eustáquio, AS}, title = {High-Yield Lasso Peptide Production in a Burkholderia Bacterial Host by Plasmid Copy Number Engineering.}, journal = {ACS synthetic biology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acssynbio.3c00597}, pmid = {38194362}, issn = {2161-5063}, abstract = {The knotted configuration of lasso peptides confers thermal stability and proteolytic resistance, addressing two shortcomings of peptide-based drugs. However, low isolation yields hinder the discovery and development of lasso peptides. While testing Burkholderia sp. FERM BP-3421 as a bacterial host to produce the lasso peptide capistruin, an overproducer clone was previously identified. In this study, we show that an increase in the plasmid copy number partially contributed to the overproducer phenotype. Further, we modulated the plasmid copy number to recapitulate titers to an average of 160% relative to the overproducer, which is 1000-fold higher than previously reported with E. coli, reaching up to 240 mg/L. To probe the applicability of the developed tools for lasso peptide discovery, we targeted a new lasso peptide biosynthetic gene cluster from endosymbiont Mycetohabitans sp. B13, leading to the isolation of mycetolassin-15 and mycetolassin-18 in combined titers of 11 mg/L. These results validate Burkholderia sp. FERM BP-3421 as a production platform for lasso peptide discovery.}, }
@article {pmid38193019, year = {2024}, author = {Mat Udin, AS and Uni, S and Rodrigues, J and Martin, C and Junker, K and Agatsuma, T and Low, VL and Saijuntha, W and Omar, H and Zainuri, NA and Fukuda, M and Matsubayashi, M and Kimura, D and Takaoka, H and Ramli, R}, title = {Redescription, molecular characterisation and Wolbachia endosymbionts of Mansonella (Tupainema) dunni (Mullin &amp; Orihel, 1972) (Spirurida: Onchocercidae) from the common treeshrew Tupaia glis Diard &amp; Duvaucel (Mammalia: Scandentia) in Peninsular Malaysia.}, journal = {Current research in parasitology &amp; vector-borne diseases}, volume = {5}, number = {}, pages = {100154}, pmid = {38193019}, issn = {2667-114X}, abstract = {The genus Mansonella Faust, 1929 includes 29 species, mainly parasites of platyrrhine monkeys in South America and anthropoid apes in Africa. In Malaysia, Mansonella (Tupainema) dunni (Mullin &amp; Orihel, 1972) was described from the common treeshrew Tupaia glis Diard &amp; Duvaucel (Scandentia). In a recent classification of the genus Mansonella, seven subgenera were proposed, with M. (Tup.) dunni as a monotypic species in the subgenus Tupainema. In this study, we collected new material of M. (Tup.) dunni from common treeshrews in Peninsular Malaysia and redescribed the morphological features of this species. We found that M. (Tup.) dunni differs from M. (Cutifilaria) perforata Uni et al., 2004 from sika deer Cervus nippon (Cetartiodactyla) in Japan, with regards to morphological features and predilection sites in their respective hosts. Based on multi-locus sequence analyses, we examined the molecular phylogeny of M. (Tup.) dunni and its Wolbachia genotype. Species of the genus Mansonella grouped monophyletically in clade ONC5 and M. (Tup.) dunni was placed in the most derived position within this genus. Mansonella (Tup.) dunni was closely related to M. (M.) ozzardi (Manson, 1897) from humans in Central and South America, and most distant from M. (C.) perforata. The calculated p-distances between the cox1 gene sequences for M. (Tup.) dunni and its congeners were 13.09% for M. (M.) ozzardi and 15.6-16.15% for M. (C.) perforata. The molecular phylogeny of Mansonella spp. thus corroborates their morphological differences. We determined that M. (Tup.) dunni harbours Wolbachia endosymbionts of the supergroup F genotype, in keeping with all other Mansonella species screened to date.}, }
@article {pmid38176202, year = {2023}, author = {Segura, JA and Dibernardo, A and Manguiat, K and Waitt, B and Rueda, ZV and Keynan, Y and Wood, H and Gutiérrez, LA}, title = {Molecular surveillance of microbial agents from cattle-attached and questing ticks from livestock agroecosystems of Antioquia, Colombia.}, journal = {Comparative immunology, microbiology and infectious diseases}, volume = {105}, number = {}, pages = {102113}, doi = {10.1016/j.cimid.2023.102113}, pmid = {38176202}, issn = {1878-1667}, abstract = {Ticks are obligate ectoparasites and vectors of pathogens affecting health, agriculture, and animal welfare. This study collected ticks from the cattle and questing ticks of 24 Magdalena Medio Antioquia region cattle farms. Genomic DNA was extracted from the specimens (individual or pools) of the 2088 adult ticks collected from cattle and 4667 immature questing ticks collected from pastures. The molecular detection of Babesia, Anaplasma, Coxiella and Rickettsia genera was performed by polymerase chain reaction amplification and subsequent DNA sequencing. In a total of 6755 Rhipicephalus microplus DNA samples, Anaplasma marginale was the most detected with a frequency of 2% (Confidence Interval- CI 1.68-2.36), followed by Babesia bigemina with 0.28% (CI 0.16-0.44), Coxiella spp. with 0.15% (CI 0.07-0.27), and Rickettsia spp. with 0.13% (CI 0.06-0.25). Molecular analysis of the DNA sequences obtained from the tick samples revealed the presence of Coxiella-like endosymbiont and R. felis. These results demonstrated the diversity of microorganisms present in R. microplus ticks predominantly associated with cattle and questing ticks from livestock agroecosystems, suggesting their role as reservoirs and potential biological vectors of these microorganisms on the studied sites. Also, it emphasizes the need to combine acarological surveillance with clinical diagnoses and control strategies on regional and national levels.}, }
@article {pmid38163636, year = {2024}, author = {Sharkey, TD}, title = {The end game(s) of photosynthetic carbon metabolism.}, journal = {Plant physiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/plphys/kiad601}, pmid = {38163636}, issn = {1532-2548}, support = {//Division of Chemical Sciences/ ; //Geosciences, and Biosciences/ ; //Office of Basic Energy Sciences/ ; DE-FG02-91ER20021//United States Department of Energy/ ; IOS-2022495//U.S. National Science Foundation/ ; //Michigan AgBioResearch/ ; }, abstract = {The year 2024 marks 70 years since the general outline of the carbon pathway in photosynthesis was published. Although several alternative pathways are now known, it is remarkable how many organisms use the reaction sequence described 70 yrs ago, which is now known as the Calvin-Benson cycle or variants such as the Calvin-Benson-Bassham cycle or Benson-Calvin cycle. However, once the carbon has entered the Calvin-Benson cycle and is converted to a 3-carbon sugar, it has many potential fates. This review will examine the last stages of photosynthetic metabolism in leaves. In land plants, this process mostly involves the production of sucrose provided by an endosymbiont (the chloroplast) to its host for use and transport to the rest of the plant. Photosynthetic metabolism also usually involves the synthesis of starch, which helps maintain respiration in the dark and enables the symbiont to supply sugars during both the day and night. Other end products made in the chloroplast are closely tied to photosynthetic CO2 assimilation. These include serine from photorespiration and various amino acids, fatty acids, isoprenoids, and shikimate pathway products. I also describe 2 pathways that can short circuit parts of the Calvin-Benson cycle. These final processes of photosynthetic metabolism play many important roles in plants.}, }
@article {pmid38150911, year = {2023}, author = {Polsomboon Nelson, S and Ergunay, K and Bourke, BP and Reinbold-Wasson, DD and Caicedo-Quiroga, L and Kirkitadze, G and Chunashvili, T and Tucker, CL and Linton, YM}, title = {Nanopore-based metagenomics reveal a new Rickettsia in Europe.}, journal = {Ticks and tick-borne diseases}, volume = {15}, number = {2}, pages = {102305}, doi = {10.1016/j.ttbdis.2023.102305}, pmid = {38150911}, issn = {1877-9603}, abstract = {Accurate identification of tick-borne bacteria, including those associated with rickettsioses, pose significant challenges due to the polymicrobial and polyvectoral nature of the infections. We aimed to carry out a comparative evaluation of a non-targeted metagenomic approach by nanopore sequencing (NS) and commonly used PCR assays amplifying Rickettsia genes in field-collected ticks. The study included a total of 310 ticks, originating from Poland (44.2 %) and Bulgaria (55.8 %). Samples comprised 7 species, the majority of which were Ixodes ricinus (62.9 %), followed by Dermacentor reticulatus (21.2 %). Screening was carried out in 55 pools, using total nucleic acid extractions from individual ticks. NS and ompA/gltA PCRs identified Rickettsia species in 47.3 % and 54.5 % of the pools, respectively. The most frequently detected species were Rickettsia asiatica (27.2 %) and Rickettsia raoultii (21.8 %), followed by Rickettsia monacensis (3.6 %), Rickettsia helvetica (1.8 %), Rickettsia massiliae (1.8 %) and Rickettsia tillamookensis (1.8 %). Phylogeny construction on mutS, uvrD, argS and virB4 sequences and a follow-up deep sequencing further supported R. asiatica identification, documented in Europe for the first time. NS further enabled detection of Anaplasma phagocytophilum (9.1 %), Coxiella burnetii (5.4 %) and Neoehrlichia mikurensis (1.8 %), as well as various endosymbionts of Rickettsia and Coxiella. Co-detection of multiple rickettsial and non-rickettsial bacteria were observed in 16.4 % of the pools with chromosome and plasmid-based contigs. In conclusion, non-targeted metagenomic sequencing was documented as a robust strategy capable of providing a broader view of the tick-borne bacterial pathogen spectrum.}, }
@article {pmid38148222, year = {2023}, author = {Kundu, A}, title = {Antimicrobial to anti-herbivore: Sakuranetin in rice efficiently inhibits brown planthopper by targeting their beneficial endosymbionts.}, journal = {Physiologia plantarum}, volume = {175}, number = {6}, pages = {e14110}, doi = {10.1111/ppl.14110}, pmid = {38148222}, issn = {1399-3054}, support = {RGCB/2023/00661//Rajiv gandhi centre for biotechnology/ ; }, abstract = {In rice, biosynthesis of specialized metabolites active against insect herbivores is elusive. The major known defense metabolites in rice against the destructive phloem-sucking herbivore brown planthoppers (BPH) (Nilaparvata lugens) are proteinase inhibitors, phenolamides and some terpenes (Xiao et al., 2012), which are induced during the invasion. Specifically, phenolamides were found to be induced upon herbivory with different feeding guild, including chewing and phloem-sucking, but could only provide defense against phloem-sucking BPH, though the clear mode of action of phenolamides has not been explored yet. Moreover, the jasmonic acid-mediated modulation of biosynthesis of these specialized metabolites in rice is not elucidated yet. However, a recent study by Liu et al. (2023) demonstrated that sakuranetin, a phytoalexin in rice, was induced upon BPH invasion and showed significant detrimental effect on herbivore's performance by targeting their beneficial endosymbionts. This is the first report on a strong bioactive anti-herbivore molecule observed in rice with an unusual mode of action. In this article, a view has been presented on this work, its impact and exceptionality.}, }
@article {pmid38143905, year = {2023}, author = {Mouillaud, T and Berger, A and Buysse, M and Rahola, N and Daron, J and Agbor, JP and Sango, SN and Neafsey, DE and Duron, O and Ayala, D}, title = {Limited association between Wolbachia and Plasmodium falciparum infections in natural populations of the major malaria mosquito Anopheles moucheti.}, journal = {Evolutionary applications}, volume = {16}, number = {12}, pages = {1999-2006}, pmid = {38143905}, issn = {1752-4571}, abstract = {Since the discovery of natural malaria vector populations infected by the endosymbiont bacterium Wolbachia, a renewed interest has arisen for using this bacterium as an alternative for malaria control. Among naturally infected mosquitoes, Anopheles moucheti, a major malaria mosquito in Central Africa, exhibits one of the highest prevalences of Wolbachia infection. To better understand whether this maternally inherited bacterium could be used for malaria control, we investigated Wolbachia influence in An. moucheti populations naturally infected by the malaria parasite Plasmodium falciparum. To this end, we collected mosquitoes in a village from Cameroon, Central Africa, where this mosquito is the main malaria vector. We found that the prevalence of Wolbachia bacterium was almost fixed in the studied mosquito population, and was higher than previously recorded. We also quantified Wolbachia in whole mosquitoes and dissected abdomens, confirming that the bacterium is also elsewhere than in the abdomen, but at lower density. Finally, we analyzed the association of Wolbachia presence and density on P. falciparum infection. Wolbachia density was slightly higher in mosquitoes infected with the malaria parasite than in uninfected mosquitoes. However, we observed no correlation between the P. falciparum and Wolbachia densities. In conclusion, our study indicates that naturally occurring Wolbachia infection is not associated to P. falciparum development within An. moucheti mosquitoes.}, }
@article {pmid38143870, year = {2023}, author = {Martins, M and César, CS and Cogni, R}, title = {The effects of temperature on prevalence of facultative insect heritable symbionts across spatial and seasonal scales.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1321341}, pmid = {38143870}, issn = {1664-302X}, abstract = {Facultative inheritable endosymbionts are common and diverse in insects and are often found at intermediate frequencies in insect host populations. The literature assessing the relationship between environment and facultative endosymbiont frequency in natural host populations points to temperature as a major component shaping the interaction. However, a synthesis describing its patterns and mechanistic basis is lacking. This mini-review aims to bridge this gap by, following an evolutionary model, hypothesizing that temperature increases endosymbiont frequencies by modulating key phenotypes mediating the interaction. Field studies mainly present positive correlations between temperature and endosymbiont frequency at spatial and seasonal scales; and unexpectedly, temperature is predominantly negatively correlated with the key phenotypes. Higher temperatures generally reduce the efficiency of maternal transmission, reproductive parasitism, endosymbiont influence on host fitness and the ability to protect against natural enemies. From the endosymbiont perspective alone, higher temperatures reduce titer and both high and low temperatures modulate their ability to promote host physiological acclimation and behavior. It is necessary to promote research programs that integrate field and laboratory approaches to pinpoint which processes are responsible for the temperature correlated patterns of endosymbiont prevalence in natural populations.}, }
@article {pmid38107563, year = {2023}, author = {Fu, J and Zhou, J and Zhou, J and Zhang, Y and Liu, L}, title = {Competitive effects of the macroalga Caulerpa taxifolia on key physiological processes in the scleractinian coral Turbinaria peltata under thermal stress.}, journal = {PeerJ}, volume = {11}, number = {}, pages = {e16646}, pmid = {38107563}, issn = {2167-8359}, mesh = {Animals ; *Anthozoa ; Chlorophyll A ; *Caulerpa ; Antioxidants ; *Seaweed/physiology ; *Physiological Phenomena ; Water ; }, abstract = {An increased abundance of macroalgae has been observed in coral reefs damaged by climate change and local environmental stressors. Macroalgae have a sublethal effect on corals that includes the inhibition of their growth, development, and reproduction. Thus, this study explored the effects of the macroalga, Caulerpa taxifolia, on the massive coral, Turbinaria peltata, under thermal stress. We compared the responses of the corals' water-meditated interaction with algae (the co-occurrence group) and those in direct contact with algae at two temperatures. The results show that after co-culturing with C. taxifolia for 28 days, the density content of the dinoflagellate endosymbionts was significantly influenced by the presence of C. taxifolia at ambient temperature (27 °C), from 1.3 × 10[6] cells cm[-2] in control group to 0.95 × 10[6] cells cm[-2] in the co-occurrence group and to 0.89 × 10[6] cells cm[-2] in the direct contact group. The chlorophyll a concentration only differed significantly between the control and the direct contact group at 27 °C. The protein content of T. peltata decreased by 37.2% in the co-occurrence group and 49.0% in the direct contact group compared to the control group. Meanwhile, the growth rate of T. peltata decreased by 57.7% in the co-occurrence group and 65.5% in the direct contact group compared to the control group. The activity of the antioxidant enzymes significantly increased, and there was a stronger effect of direct coral contact with C. taxifolia than the co-occurrence group. At 30 °C, the endosymbiont density, chlorophyll a content, and growth rate of T. peltata significantly decreased compared to the control temperature; the same pattern was seen in the increase in antioxidant enzyme activity. Additionally, when the coral was co-cultured with macroalgae at 30 °C, there was no significant decrease in the density or chlorophyll a content of the endosymbiont compared to the control. However, the interaction of macroalgae and elevated temperature was evident in the feeding rate, protein content, superoxide dismutase (SOD), and catalase (CAT) activity compared to the control group. The direct contact of the coral with macroalga had a greater impact than water-meditated interactions. Hence, the competition between coral and macroalga may be more intense under thermal stress.}, }
@article {pmid38106215, year = {2023}, author = {Maeda, GP and Kelly, MK and Sundar, A and Moran, NA}, title = {Intracellular defensive symbiont is culturable and capable of transovarial, vertical transmission.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.12.05.570145}, pmid = {38106215}, abstract = {UNLABELLED: Insects frequently form heritable associations with beneficial bacteria that are vertically transmitted from parent to offspring. Long term vertical transmission has repeatedly resulted in genome reduction and gene loss rendering many such bacteria incapable of independent culture. Among aphids, heritable endosymbionts often provide a wide range of context-specific benefits to their hosts. Although these associations have large impacts on host phenotypes, experimental approaches are often limited by an inability to independently cultivate these microbes. Here, we report the axenic culture of Candidatus Fukatsuia symbiotica strain WIR, a heritable bacterial endosymbiont of the pea aphid, Acyrthosiphon pisum . Whole genome sequencing revealed similar genomic features and high sequence similarity to previously described strains, suggesting the cultivation techniques used here may be applicable to Ca . F. symbiotica strains from distantly related aphids. Microinjection of the isolated strain into uninfected aphids revealed that it can reinfect developing embryos, and is maintained in subsequent generations via transovarial maternal transmission. Artificially infected aphids exhibit similar phenotypic and life history traits compared to native infections, including protective effects against an entomopathogenic Fusarium species. Overall, our results show that Ca . F. symbiotica may be a useful tool for experimentally probing the molecular mechanisms underlying heritable symbioses and antifungal defense in the pea aphid system.<br><br>IMPORTANCE: Diverse eukaryotic organisms form stable, symbiotic relationships with bacteria that provide benefits to their hosts. While these associations are often biologically important, they can be difficult to probe experimentally, because intimately host-associated bacteria are difficult to access within host tissues, and most cannot be cultured. This is especially true of the intracellular, maternally inherited bacteria associated with many insects, including aphids. Here, we demonstrate that a pea aphid-associated strain of the heritable endosymbiont, Candidatus Fukatsuia symbiotica, can be grown outside of its host using standard microbiology techniques, and can readily re-establish infection that is maintained across host generations. These artificial infections recapitulate the effects of native infections making this host-symbiont pair a useful experimental system. Using this system, we demonstrate that Ca . F. symbiotica infection reduces host fitness under benign conditions, but protects against a previously unreported fungal pathogen.}, }
@article {pmid38105949, year = {2023}, author = {Shropshire, JD and Conner, WR and Vanderpool, D and Hoffmann, AA and Turelli, M and Cooper, BS}, title = {Rapid turnover of pathogen-blocking Wolbachia and their incompatibility loci.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.12.04.569981}, pmid = {38105949}, abstract = {UNLABELLED: At least half of all insect species carry maternally inherited Wolbachia alphaproteobacteria, making Wolbachia the most common endosymbionts in nature. Wolbachia spread to high frequencies is often due to cytoplasmic incompatibility (CI), a Wolbachia -induced sperm modification that kills embryos without Wolbachia . Several CI-causing Wolbachia variants, including w Mel from Drosophila melanogaster , also block viruses. Establishing pathogen-blocking w Mel in natural Aedes aegypti mosquito populations has reduced dengue disease incidence, with one study reporting about 85% reduction when w Mel frequency is high. However, w Mel transinfection establishment is challenging in many environments, highlighting the importance of identifying CI-causing Wolbachia variants that stably persist in diverse hosts and habitats. We demonstrate that w Mel-like variants have naturally established in widely distributed holometabolous dipteran and hymenopteran insects that diverged approximately 350 million years ago, with w Mel variants spreading rapidly among these hosts over only the last 100,000 years. Wolbachia genomes contain prophages that encode CI-causing operons (cifs). These cifs move among Wolbachia genomes - with and without prophages - even more rapidly than Wolbachia move among insect hosts. Our results shed light on how rapid host switching and horizontal gene transfer contribute to Wolbachia and cif diversity in nature. The diverse w Mel variants we report here from hosts present in different climates offer many new options for broadening Wolbachia -based biocontrol of diseases and pests.<br><br>SIGNIFICANCE STATEMENT: Wolbachia bacteria transinfected into Aedes aegypti mosquitoes (in particular the w Mel Wolbachia strain) are being widely released to suppress the transmission of dengue and other insect-vectored arboviruses. The bacterial strain w Mel originated from Drosophila melanogaster , but very little is known about its distribution and spread to other drosophilids and distantly related insects. Here we show that there has been a rapid rate of spread of Wolbachia strains closely related to w Mel not just into other flies but also into wasps, indicating a large pool of w Mel variants that can be employed in vector-borne disease control. Wolbachia prophage genes essential to this spread have evolved particularly rapidly.}, }
@article {pmid38104431, year = {2023}, author = {Lau, DC and Power, RI and Šlapeta, J}, title = {Exploring multiplex qPCR as a diagnostic tool for detecting microfilarial DNA in dogs infected with Dirofilaria immitis: A comparative analysis with the modified Knott's test.}, journal = {Veterinary parasitology}, volume = {325}, number = {}, pages = {110097}, doi = {10.1016/j.vetpar.2023.110097}, pmid = {38104431}, issn = {1873-2550}, abstract = {Current recommendations to diagnose cardiopulmonary dirofilariosis in dogs caused by Dirofilaria immitis involves tandem antigen and circulating microfilariae tests. The modified Knott's test is an important tool in heartworm diagnosis, allowing identification of circulating microfilariae. However, the subjective nature of the modified Knott's test affects its accuracy and diagnostic laboratories usually do not provide a quantitative outcome. Quantitative enumeration of microfilariae enables clinicians to track treatment progress and acts as a proxy for detecting emerging macrocyclic lactone resistance. There is a need for better diagnostic tools suitable for routine use to efficiently and accurately quantify the presence of D. immitis microfilaremia. The aim of this study was to determine whether the quantitative modified Knott's test can be substituted by multiplex quantitative polymerase chain reaction (qPCR) targeting D. immitis and associated Wolbachia endosymbiont DNA in canine blood samples. To do this, genomic DNA samples (n = 161) from Australian dogs, collected as part of a previous 2021 study, were assessed in a TaqMan qPCR targeting DNA of D. immitis, Wolbachia sp. and Canis lupus familiaris. Of the 161 genomic DNA samples, eight were considered positive for D. immitis microfilariae. The qPCR assay demonstrated good efficiency (E = 90 to 110%, R[2] > 0.94). Considering the performance and efficient use of bench time, this TaqMan qPCR assay is a suitable alternative to the modified Knott's test for quantitative enumeration of microfilariae (Cohen's kappa coefficient [κ]: κ = 1 using D. immitis qPCR marker, κ = 0.93 using Wolbachia qPCR marker). The qPCR data demonstrated a comparable result to that of the quantitative modified Knott's test in a 2022 survey of D. immitis in Australian dogs (n = 23) before and after macrocyclic lactone (ML) administration. Improving the detection and diagnosis of canine heartworm infections will assist veterinarians in better managing and controlling disease outcomes and will be valuable for tracking the spread of ML resistance in Australia.}, }
@article {pmid38097942, year = {2023}, author = {Mirabedini, Z and Mirjalali, H and Kazemirad, E and Khamesipour, A and Samimirad, K and Koosha, M and Saberi, R and Rahimi, HM and Mohebali, M and Hajjaran, H}, title = {The effects of Leishmania RNA virus 2 (LRV2) on the virulence factors of L. major and pro-inflammatory biomarkers: an in vitro study on human monocyte cell line (THP-1).}, journal = {BMC microbiology}, volume = {23}, number = {1}, pages = {398}, pmid = {38097942}, issn = {1471-2180}, support = {IR.TUMS.SPH.REC.1400.251//Tehran University of Medical Science/ ; }, mesh = {Humans ; NLR Family, Pyrin Domain-Containing 3 Protein ; Monocytes ; Interleukin-18 ; *Leishmania ; *Leishmaniavirus/genetics ; *Leishmaniasis, Cutaneous ; *RNA Viruses/genetics ; Biomarkers ; }, abstract = {BACKGROUND: Cutaneous Leishmaniasis (CL) is a parasitic disease with diverse outcomes. Clinical diversity is influenced by various factors such as Leishmania species and host genetic background. The role of Leishmania RNA virus (LRV), as an endosymbiont, is suggested to not only affect the pathogenesis of Leishmania, but also impact host immune responses. This study aimed to investigate the influence of LRV2 on the expression of a number of virulence factors (VFs) of Leishmania and pro-inflammatory biomarkers.<br><br>MATERIALS AND METHODS: Sample were obtained from CL patients from Golestan province. Leishmania species were identified by PCR (LIN 4, 17), and the presence of LRV2 was checked using the semi-nested PCR (RdRp gene). Human monocyte cell line (THP-1) was treated with three isolates of L. major with LRV2 and one isolate of L. major without LRV2. The treatments with four isolates were administered for the time points: zero, 12, 24, 36, and 48&#xa0;h after co-infection. The expression levels of Leishmania VFs genes including GP63, HSP83, and MPI, as well as pro-inflammatory biomarkers genes including NLRP3, IL18, and IL1&#x3b2;, were measured using quantitative real-time PCR.<br><br>RESULTS: The expression of GP63, HSP83, and MPI revealed up-regulation in LRV2&#x2009;+&#x2009;isolates compared to LRV2- isolates. The expression of the pro-inflammatory biomarkers including NLRP3, IL1&#x3b2;, and IL18 genes in LRV2- were higher than LRV2&#x2009;+&#x2009;isolates.<br><br>CONCLUSION: This finding suggests that LRV2&#x2009;+&#x2009;may have a probable effect on the Leishmania VFs and pro-inflammatory biomarkers in the human macrophage model.}, }
@article {pmid38088471, year = {2023}, author = {Gonzalez-Gonzalez, A and Cabrera, N and Rubio-Meléndez, ME and Sepúlveda, DA and Ceballos, R and Fernández, N and Francis, F and Figueroa, CC and Ramirez, CC}, title = {Facultative endosymbionts modulate the aphid reproductive performance on wheat cultivars differing in contents of benzoxazinoids.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7932}, pmid = {38088471}, issn = {1526-4998}, abstract = {BACKGROUND: Facultative bacterial endosymbionts have the potential to influence the interactions between aphids, their natural enemies, and host plants. Among the facultative symbionts found in populations of the grain aphid Sitobion avenae in Central Chile, the bacterium Regiella insecticola is the most prevalent. In this study, we aimed to investigate whether infected and cured aphid lineages exhibit differential responses to wheat cultivars containing varying levels of the benzoxazinoid DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one), which is a xenobiotic compound produced by plants. Specifically, we examined the reproductive performance responses of the most frequently encountered genotypes of S. avenae when reared on wheat seedlings expressing low, medium, and high concentrations of DIMBOA.<br><br>RESULTS: Our findings reveal that the intrinsic rate of population increase (rm) in cured lineages of S. avenae genotypes exhibits a biphasic pattern, characterized by the lowest rm and an extended time to first reproduction on wheat seedlings with medium levels of DIMBOA. In contrast, the aphid genotypes harbouring R. insecticola display idiosyncratic responses, with the two most prevalent genotypes demonstrating improved performance on seedlings featuring an intermediate content of DIMBOA compared to their cured counterparts.<br><br>CONCLUSION: This study represents the first investigation into the mediating impact of facultative endosymbionts on aphid performance in plants exhibiting varying DIMBOA contents. These findings present exciting prospects for identifying novel targets for aphid control by manipulating the presence of aphid symbionts. This article is protected by copyright. All rights reserved.}, }
@article {pmid38087390, year = {2023}, author = {Ferrarini, MG and Vallier, A and Vincent-Monégat, C and Dell'Aglio, E and Gillet, B and Hughes, S and Hurtado, O and Condemine, G and Zaidman-Rémy, A and Rebollo, R and Parisot, N and Heddi, A}, title = {Coordination of host and endosymbiont gene expression governs endosymbiont growth and elimination in the cereal weevil Sitophilus spp.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {274}, pmid = {38087390}, issn = {2049-2618}, support = {ANR-17-CE20-0031-01//Agence Nationale de la Recherche/ ; ANR-17-CE20-0015//Agence Nationale de la Recherche/ ; ANR-17-CE20-0015//Agence Nationale de la Recherche/ ; ANR-17-CE20-0031-01//Agence Nationale de la Recherche/ ; }, abstract = {BACKGROUND: Insects living in nutritionally poor environments often establish long-term relationships with intracellular bacteria that supplement their diets and improve their adaptive and invasive powers. Even though these symbiotic associations have been extensively studied on physiological, ecological, and evolutionary levels, few studies have focused on the molecular dialogue between host and endosymbionts to identify genes and pathways involved in endosymbiosis control and dynamics throughout host development.<br><br>RESULTS: We simultaneously analyzed host and endosymbiont gene expression during the life cycle of the cereal weevil Sitophilus oryzae, from larval stages to adults, with a particular emphasis on emerging adults where the endosymbiont Sodalis pierantonius experiences a contrasted growth-climax-elimination dynamics. We unraveled a constant arms race in which different biological functions are intertwined and coregulated across both partners. These include immunity, metabolism, metal control, apoptosis, and bacterial stress response.<br><br>CONCLUSIONS: The study of these tightly regulated functions, which are at the center of symbiotic regulations, provides evidence on how hosts and bacteria finely tune their gene expression and respond to different physiological challenges constrained by insect development in a nutritionally limited ecological niche. Video Abstract.}, }
@article {pmid38078889, year = {2023}, author = {Schwartz, HT and Tan, CH and Peraza, J and Raymundo, KLT and Sternberg, PW}, title = {Molecular identification of a peroxidase gene controlling body size in the entomopathogenic nematode Steinernema hermaphroditum.}, journal = {Genetics}, volume = {}, number = {}, pages = {}, doi = {10.1093/genetics/iyad209}, pmid = {38078889}, issn = {1943-2631}, abstract = {The entomopathogenic nematode Steinernema hermaphroditum was recently rediscovered and is being developed as a genetically tractable experimental system for the study of previously unexplored biology, including parasitism of its insect hosts and mutualism with its bacterial endosymbiont Xenorhabdus griffiniae. Through whole-genome re-sequencing and genetic mapping we have for the first time molecularly identified the gene responsible for a mutationally defined phenotypic locus in an entomopathogenic nematode. In the process we observed an unexpected mutational spectrum following EMS mutagenesis in this species. We find that the ortholog of the essential C. elegans peroxidase gene skpo-2 controls body size and shape in S. hermaphroditum. We confirmed this identification by generating additional loss-of-function mutations in the gene using CRISPR-Cas9. We propose that the identification of skpo-2 will accelerate gene targeting in other Steinernema entomopathogenic nematodes used commercially in pest control, as skpo-2 is X-linked and males hemizygous for loss of its function can mate, making skpo-2 an easily recognized and maintained marker for use in co-CRISPR.}, }
@article {pmid38072824, year = {2023}, author = {Valadez-Cano, C and Olivares-Hernández, R and Espino-Vázquez, AN and Partida-Martínez, LP}, title = {Genome-Scale Model of Rhizopus microsporus: Metabolic integration of a fungal holobiont with its bacterial and viral endosymbionts.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16551}, pmid = {38072824}, issn = {1462-2920}, support = {FOINS-2015-01-006//Consejo Nacional de Ciencia y Tecnolog&#xed;a/ ; }, abstract = {Rhizopus microsporus often lives in association with bacterial and viral symbionts that alter its biology. This fungal model represents an example of the complex interactions established among diverse organisms in functional holobionts. We constructed a Genome-Scale Model (GSM) of the fungal-bacterial-viral holobiont (iHol). We employed a constraint-based method to calculate the metabolic fluxes to decipher the metabolic interactions of the symbionts with their host. Our computational analyses of iHol simulate the holobiont's growth and the production of the toxin rhizoxin. Analyses of the calculated fluxes between R. microsporus in symbiotic (iHol) versus asymbiotic conditions suggest that changes in the lipid and nucleotide metabolism of the host are necessary for the functionality of the holobiont. Glycerol plays a pivotal role in the fungal-bacterial metabolic interaction, as its production does not compromise fungal growth, and Mycetohabitans bacteria can efficiently consume it. Narnavirus RmNV-20S and RmNV-23S affected the nucleotide metabolism without impacting the fungal-bacterial symbiosis. Our analyses highlighted the metabolic stability of Mycetohabitans throughout its co-evolution with the fungal host. We also predicted changes in reactions of the bacterial metabolism required for the active production of rhizoxin. This iHol is the first GSM of a fungal holobiont.}, }
@article {pmid37994906, year = {2023}, author = {Meyer, DF and Moumène, A and Rodrigues, V}, title = {Microbe Profile: Ehrlichia ruminantium - stealthy as it goes.}, journal = {Microbiology (Reading, England)}, volume = {169}, number = {11}, pages = {}, pmid = {37994906}, issn = {1465-2080}, mesh = {*Ehrlichia ruminantium ; }, abstract = {Ehrlichia ruminantium is an obligate intracellular pathogenic bacterium that causes heartwater, a fatal disease of ruminants in tropical areas. Some human cases have also been reported. This globally important pathogen is primarily transmitted by ticks of the Amblyomma genus and threatens American mainland. E. ruminantium replicates within eukaryotic mammal or tick cell is a membrane-bound vacuole, where it undergoes a biphasic developmental growth cycle and differentiates from noninfectious replicative form into infectious elementary bodies. The ability of E. ruminantium to hijack host cellular processes and avoid innate immunity is a fundamental, but not yet fully understood, virulence trait of this stealth pathogen in the genomic era.}, }
@article {pmid38072536, year = {2023}, author = {Zhou, YM and Xie, W and Zhi, JR and Zou, X}, title = {Frankliniella occidentalis pathogenic fungus Lecanicillium interacts with internal microbes and produces sublethal effects.}, journal = {Pesticide biochemistry and physiology}, volume = {197}, number = {}, pages = {105679}, doi = {10.1016/j.pestbp.2023.105679}, pmid = {38072536}, issn = {1095-9939}, abstract = {Frankliniella occidentalis (Thysanoptera: Thripidae) is a pest that feeds on various crops worldwide. A prior study identified Lecanicillium attenuatum and L. cauligalbarum as pathogens of F. occidentalis. Unfortunately, the potential of these two entomopathogenic fungi for the biocontrol of F. occidentalis has not been effectively evaluated. The internal microbes (endosymbionts and the gut microbiota) of insects, especially gut bacteria, are crucial in regulating the interactions between the host and intestinal pathogens. The role of thrips internal microbes in the infection of these two entomopathogenic fungi is also unknown. Therefore, biological control of thrips is immediately needed, and to accomplish that, an improved understanding of the internal microbes of thrips against Lecanicillium infection is essential. The virulence of the two pathogenic fungi against F. occidentalis increased with the conidia concentration. Overall, the LC50 of L. cauligalbarum was lower than that of L. attenuatum, and the pathogenicity degree was adult > pupa > nymphs. The activities of protective enzymes include superoxide dismutase (SOD), catalase (CAT), peroxidase (POD); detoxification enzymes include polyphenol oxidase (PPO), glutathione s-transferase (GSTs), and carboxylesterase (CarE); hormones include ecdysone and juvenile hormone; and the composition and proportion of microorganisms (fungi and bacteria) in F. occidentalis infected by L. cauligalbarum and L. attenuatum have changed significantly. According to the network correlation results, there was a considerable correlation among the internal microbes (including bacteria and fungi), enzyme activities, and hormones, which indicates that in addition to bacteria, internal fungi of F. occidentalis are also involved in the L. cauligalbarum and L. attenuatum infection process. In addition, the development time of the surviving F. occidentalis exposed to L. cauligalbarum or L. attenuatum was significantly shorter than that of the control group. Furthermore, the intrinsic rate of increase (rm), finite rate of increase (λ), net reproductive rate (R0), mean generation time (T), and gross reproductive rate (GRR) were significantly lower in the treatment groups than in the control group. L. attenuatum and L. cauligalbarum have biocontrol potential against F. occidentalis. In addition to bacteria, internal fungi of F. occidentalis are also involved in the infection process of insect pathogenic fungi. Disruption of the internal microbial balance results in discernible sublethal effects. Such prevention and control potential should not be ignored. These findings provide an improved understanding of physiological responses in thrips with altered immunity against entomopathogenic fungal infections, which can guide us toward the development of novel biocontrol strategies against thrips.}, }
@article {pmid38071646, year = {2023}, author = {Urairi, C and Fujito, S}, title = {Interbiotype hybridization between biotypes A and B of Liriomyza chinensis (Diptera: Agromyzidae).}, journal = {Journal of economic entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jee/toad223}, pmid = {38071646}, issn = {1938-291X}, abstract = {Liriomyza chinensis (Kato) is a formidable pest of Allium species, especially the Japanese bunching onion Allium fistulosum L. Recently, a novel biotype of L. chinensis (biotype B) has emerged, which causes more severe damage than the native biotype A. It has been reported that biotype B has frequently displaced biotype A in the Japanese bunching onion fields in Japan. As interbiotype hybridization is a possible factor that influences such displacement, interbiotype hybridization was conducted between L. chinensis biotypes A and B. Eggs were not laid under one-by-one crossing conditions; however, adult hybrid progeny of both sexes emerged from no-choice mating combinations-when multiple males and females were present. The fertility of F1 hybrid adults was also investigated, and backcrossed adults emerged from F1 females in both mating combinations. F1 males might have exhibited reproductive abnormalities because only a small number of backcross progeny emerged from the mating combinations using F1 males. Additionally, 3 representative endosymbionts (Wolbachia, Spiroplasma, and Cardinium) were investigated, and both biotypes were found to be infected by the same strain of Wolbachia. In addition, the courtship signals (tapping) of male adults differed between biotypes A and B as well as between F1 hybrids; the F1 males exhibited tapping behavior that was intermediate between biotypes A and B. Therefore, mating sounds serve as a form of premating reproductive isolation between biotypes A and B.}, }
@article {pmid38070273, year = {2023}, author = {Zhang, B and Wang, X and Aguli Nurland, R and Lu, M and Guan, Y and Liu, M and Gao, F and Li, K}, title = {Investigation of tick-borne bacterial microorganisms in Haemaphysalis ticks from Hebei, Shandong, and Qinghai provinces, China.}, journal = {Ticks and tick-borne diseases}, volume = {15}, number = {2}, pages = {102290}, doi = {10.1016/j.ttbdis.2023.102290}, pmid = {38070273}, issn = {1877-9603}, abstract = {Tick-borne microorganisms in many tick species and many areas of China are still not thoroughly investigated. In this study, 224 ticks including two species (Haemaphysalis longicornis and Haemaphysalis qinghaiensis) were collected from four cities in Hebei, Shandong, and Qinghai provinces, China. Ticks were screened for the presence of tick-borne bacterial microorganisms including Rickettsia, Anaplasmataceae (Anaplasma, Ehrlichia, Neoehrlichia, etc.), Coxiella, Borrelia, and Bartonella. Two Anaplasma species (Anaplasma ovis and Anaplasma capra) were detected in H. longicornis from Xingtai City of Hebei Province, with a positive rate of 3 % and 8 %, respectively. A Coxiella species was detected in H. longicornis ticks from all three locations in Hebei and Shandong provinces, with the positive rate ranging from 30 to 75 %. All the 16S and rpoB sequences were very similar (99.77-100 % identity) to Coxiella endosymbiont of Haemaphysalis ticks. An Ehrlichia species was detected in H. qinghaiensis (6/66, 9 %) from Xining City, Qinghai Province. The 16S and groEL sequences had 100 % and 97.40-97.85 % nucleotide identities to "Candidatus Ehrlichia pampeana" strains, respectively, suggesting that it may be a variant of "Candidatus Ehrlichia pampeana". All the ticks were negative for Rickettsia, Borrelia, and Bartonella. Because all the ticks were removed from goats or humans and were partially or fully engorged, it is possible that the microorganisms were from the blood meal but not vectored by the ticks. Our results may provide some information on the diversity and distribution of tick-borne pathogens in China.}, }
@article {pmid38047686, year = {2023}, author = {Zhang, W and Wang, J and Huang, Z and He, X and Wei, C}, title = {Symbionts in Hodgkinia-free cicadas and their implications for co-evolution between endosymbionts and host insects.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0137323}, doi = {10.1128/aem.01373-23}, pmid = {38047686}, issn = {1098-5336}, abstract = {Obligate symbionts in sap-sucking hemipterans are harbored in either the same or different organs, which provide a unique perspective for uncovering complicated insect-microbe symbiosis. Here, we investigated the distribution of symbionts in adults of 10 Hodgkinia-free cicada species of 2 tribes (Sonatini and Polyneurini) and the co-phylogeny between 65 cicada species and related symbionts (Sulcia and YLSs). We revealed that YLSs commonly colonize the bacteriome sheath besides the fat bodies in these two tribes, which is different with that in most other Hodgkinia-free cicadas. Co-phylogeny analyses between cicadas and symbionts suggest that genetic variation of Sulcia occurred in Sonatini and some other cicada lineages and more independent replacement events in the loss of Hodgkinia/acquisition of YLS in Cicadidae. Our results provide new information on the complex relationships between auchenorrhynchans and related symbionts.}, }
@article {pmid38038450, year = {2023}, author = {Wang, X-R and Cull, B and Oliver, JD and Kurtti, TJ and Munderloh, UG}, title = {The role of autophagy in tick-endosymbiont interactions: insights from Ixodes scapularis and Rickettsia buchneri.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0108623}, doi = {10.1128/spectrum.01086-23}, pmid = {38038450}, issn = {2165-0497}, abstract = {Ticks are second only to mosquitoes in their importance as vectors of disease agents; however, tick-borne diseases (TBDs) account for the majority of all vector-borne disease cases in the United States (approximately 76.5%), according to Centers for Disease Control and Prevention reports. Newly discovered tick species and their associated disease-causing pathogens, and anthropogenic and demographic factors also contribute to the emergence and re-emergence of TBDs. Thus, incorporating different tick control approaches based on a thorough knowledge of tick biology has great potential to prevent and eliminate TBDs in the future. Here we demonstrate that replication of a transovarially transmitted rickettsial endosymbiont depends on the tick's autophagy machinery but not on apoptosis. Our findings improve our understanding of the role of symbionts in tick biology and the potential to discover tick control approaches to prevent or manage TBDs.}, }
@article {pmid38021190, year = {2023}, author = {Bawm, S and Khaing, Y and Chel, HM and Hmoon, MM and Win, SY and Bo, M and Naing, T and Htun, LL}, title = {Molecular detection of Dirofilaria immitis and its Wolbachia endosymbionts in dogs from Myanmar.}, journal = {Current research in parasitology &amp; vector-borne diseases}, volume = {4}, number = {}, pages = {100148}, pmid = {38021190}, issn = {2667-114X}, abstract = {Heartworm disease in dogs and cats caused by Dirofilaria immitis continues to be a major clinical issue globally. This study focused on dogs suspicious of having tick-borne diseases (TBD) brought to a clinic and a veterinary teaching hospital in Myanmar. Blood samples were collected and initially screened using SNAP® 4Dx® Plus test kit. All dog blood samples were subjected to conventional PCR to detect both Dirofilaria spp. (cox1 gene) and Wolbachia spp. (16S rDNA) infections. Infection with D. immitis was detected in 14 (28.0%) of 50 examined samples, while the detection rate of TBD causative agents, including Anaplasma phagocytophilum and Ehrlichia canis, was 26.0% (13/50) and 26.0% (13/50), respectively, as determined by ELISA rapid test. In this study, D. immitis infection was moderately but significantly correlated with TBD infections (Pearson's r = 0.397, P = 0.008). Comparative sequence and phylogenetic analyses provided molecular identification of D. immitis in Myanmar and confirmed the identity of its Wolbachia endosymbiont with Wolbachia endosymbionts isolated from D. immitis, Rhipicephalus sanguineus and Aedes aegypti. The present study contributes to our understanding of the coexistence of D. immitis and Wolbachia endosymbiosis in dogs, and the findings may benefit the future prevention and control of dirofilariasis in dogs.}, }
@article {pmid38018626, year = {2023}, author = {Sperandio, NDC and Tunholi, VM and Amaral, LS and Vidal, MLB and Cassani, LS and Tunholi-Alves, VM and Couto-Chambarelli, MCMD and Boeloni, JN and Monteiro, C and Martins, IVF}, title = {Influence of exposure Heterorhabditis bacteriophora HP88, (Rhabditida: Heterorhabditidae) on biological and physiological parameters of Pseudosuccinea columella (Basommatophora: Lymnaeidae).}, journal = {Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria}, volume = {32}, number = {4}, pages = {e007023}, doi = {10.1590/S1984-29612023072}, pmid = {38018626}, issn = {1984-2961}, abstract = {Many studies about fasciolosis control have been carried out, whether acting on the adult parasite or in Pseudosuccinea columella, compromising the development of the larval stages. The present study aimed to evaluate, under laboratory conditions, the susceptibility of P. columella to Heterorhabditis bacteriophora HP88, during for 24 and 48 hours of exposure. The snails were evaluated for 21 days for accumulated mortality; number of eggs laid; hatchability rate; biochemical changes; and histopathological analysis. We found that exposure induced a reduction in glucose and glycogen levels, characterizing a negative energy balance, due to the depletion of energy reserves as a result of the direct competition established by the nematode/endosymbiont bacteria complex in such substrates. A mortality rate of 48.25% and 65.52% was observed in the group exposed for 24 h and 48 h, respectively, along with significant impairment of reproductive biology in both exposed groups in relation to the respective controls. The results presented here show that P. columella is susceptible to the nematode H. bacteriophora, with the potential to be used as an alternative bioagent in the control of this mollusk, especially in areas considered endemic for fascioliasis, in line with the position expressed by the World Health Organization Health.}, }
@article {pmid38016137, year = {2023}, author = {Azarm, A and Koosha, M and Dalimi, A and Zahraie-Ramazani, A and Akhavan, AA and Saeidi, Z and Mohebali, M and Azam, K and Vatandoost, H and Oshaghi, MA}, title = {Association Between Wolbachia Infection and Susceptibility to Deltamethrin Insecticide in Phlebotomus papatasi (Diptera: Psychodidae), the Main Vector of Zoonotic Cutaneous Leishmaniasis.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {}, number = {}, pages = {}, doi = {10.1089/vbz.2023.0085}, pmid = {38016137}, issn = {1557-7759}, abstract = {Background: Phlebotomus papatasi (Diptera: Psychodidae) is the main vector of zoonotic cutaneous leishmaniasis. Wolbachia is a symbiotic alphaproteobacteria of arthropods that can be involved in susceptibility or resistance. This study aimed to investigate the relationship between Wolbachia and Deltamethrin susceptibility/resistance in Ph. papatasi. Deltamethrin filter papers (0.00002%) were used to test sand fly field collected from southern Iran. After the test, PCR amplification of the Wolbachia surface protein gene (wsp) was used to measure Wolbachia infection rate in the killed, surviving, and control groups. Result: The rates of infection by Wolbachia strain (wPap, super group A) differed between killed (susceptible) and surviving (resistant) Ph. papatasi specimens. The rate of Wolbachia infection in susceptible individuals was more than twice (2.3) (39% vs. 17%) in resistant individuals with the same genetic background. This difference was highly significant (p < 0.001), indicating a positive association between Wolbachia infection and susceptibility to Deltamethrin. In addition, the results showed that Deltamethrin can act as a PCR inhibitor during detection of Wolbachia in Ph. papatasi. Conclusion: Results of this study show that Wolbachia is associated with Deltamethrin susceptibility level in Ph. papatasi. Also, as Deltamethrin has been identified as a PCR inhibitor, great care must be taken in interpreting Wolbachia infection status in infected populations. The results of this study may provide information for a better understanding of the host-symbiont relationship, as well as application of host symbiosis in pest management.}, }
@article {pmid38010882, year = {2023}, author = {Espada-Hinojosa, S and Karthäuser, C and Srivastava, A and Schuster, L and Winter, T and de Oliveira, AL and Schulz, F and Horn, M and Sievert, S and Bright, M}, title = {Comparative genomics of a vertically transmitted thiotrophic bacterial ectosymbiont and its close free-living relative.}, journal = {Molecular ecology resources}, volume = {}, number = {}, pages = {}, doi = {10.1111/1755-0998.13889}, pmid = {38010882}, issn = {1755-0998}, support = {P 24565//Austrian Science Fund/ ; P 32197//Austrian Science Fund/ ; //WHOI Investment in Science Fund/ ; }, abstract = {Thiotrophic symbioses between sulphur-oxidizing bacteria and various unicellular and metazoan eukaryotes are widespread in reducing marine environments. The giant colonial ciliate Zoothamnium niveum, however, is the only host of thioautotrophic symbionts that has been cultivated along with its symbiont, the vertically transmitted ectosymbiont Candidatus Thiobius zoothamnicola (short Thiobius). Because theoretical predictions posit a smaller genome in vertically transmitted endosymbionts compared to free-living relatives, we investigated whether this is true also for an ectosymbiont. We used metagenomics to recover the high-quality draft genome of this bacterial symbiont. For comparison we have also sequenced a closely related free-living cultured but not formally described strain Milos ODIII6 (short ODIII6). We then performed comparative genomics to assess the functional capabilities at gene, metabolic pathway and trait level. 16S rRNA gene trees and average amino acid identity confirmed the close phylogenetic relationship of both bacteria. Indeed, Thiobius has about a third smaller genome than its free-living relative ODIII6, with reduced metabolic capabilities and fewer functional traits. The functional capabilities of Thiobius were a subset of those of the more versatile ODIII6, which possessed additional genes for oxygen, sulphur and hydrogen utilization and for the acquisition of phosphorus illustrating features that may be adaptive for the unstable environmental conditions at hydrothermal vents. In contrast, Thiobius possesses genes potentially enabling it to utilize lactate and acetate heterotrophically, compounds that may be provided as byproducts by the host. The present study illustrates the effect of strict host-dependence of a bacterial ectosymbiont on genome evolution and host adaptation.}, }
@article {pmid38009998, year = {2023}, author = {Naka, H and Haygood, MG}, title = {The dual role of TonB genes in turnerbactin uptake and carbohydrate utilization in the shipworm symbiont Teredinibacter turnerae.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0074423}, doi = {10.1128/aem.00744-23}, pmid = {38009998}, issn = {1098-5336}, abstract = {This study highlights diversity in iron acquisition and regulation in bacteria. The mechanisms of iron acquisition and its regulation in Teredinibacter turnerae, as well as its connection to cellulose utilization, a hallmark phenotype of T. turnerae, expand the paradigm of bacterial iron acquisition. Two of the four TonB genes identified in T. turnerae exhibit functional redundancy and play a crucial role in siderophore-mediated iron transport. Unlike typical TonB genes in bacteria, none of the TonB genes in T. turnerae are clearly iron regulated. This unusual regulation could be explained by another important finding in this study, namely, that the two TonB genes involved in iron transport are also essential for cellulose utilization as a carbon source, leading to the expression of TonB genes even under iron-rich conditions.}, }
@article {pmid38006562, year = {2024}, author = {Serbus, LR}, title = {A Light in the Dark: Uncovering Wolbachia-Host Interactions Using Fluorescence Imaging.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2739}, number = {}, pages = {349-373}, pmid = {38006562}, issn = {1940-6029}, mesh = {Animals ; *Wolbachia/genetics ; *Arthropods/microbiology ; *Nematoda ; Symbiosis ; Optical Imaging ; }, abstract = {The success of microbial endosymbionts, which reside naturally within a eukaryotic "host" organism, requires effective microbial interaction with, and manipulation of, the host cells. Fluorescence microscopy has played a key role in elucidating the molecular mechanisms of endosymbiosis. For 30 years, fluorescence analyses have been a cornerstone in studies of endosymbiotic Wolbachia bacteria, focused on host colonization, maternal transmission, reproductive parasitism, horizontal gene transfer, viral suppression, and metabolic interactions in arthropods and nematodes. Fluorescence-based studies stand to continue informing Wolbachia-host interactions in increasingly detailed and innovative ways.}, }
@article {pmid38006558, year = {2024}, author = {Valerio, F and Twort, VG and Duplouy, A}, title = {A Worked Example of Screening Genomic Material for the Presence of Wolbachia Infection.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2739}, number = {}, pages = {275-299}, doi = {10.1007/978-1-0716-3553-7_17}, pmid = {38006558}, issn = {1940-6029}, abstract = {This chapter gives a brief overview of how to screen existing host genomic data for the presence of endosymbionts, such as Wolbachia. The various programs used provide test examples, and the corresponding manuals and discussion boards provide invaluable information. Please do consult these resources.}, }
@article {pmid38006554, year = {2024}, author = {Walker, T}, title = {Detection of Natural Wolbachia Strains in Anopheles Mosquitoes.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2739}, number = {}, pages = {205-218}, pmid = {38006554}, issn = {1940-6029}, abstract = {Wolbachia is an endosymbiotic bacterium that naturally infects many insect species, including mosquitoes that transmit human diseases. Wolbachia strains have been shown to inhibit the transmission of both arboviruses and malaria Plasmodium parasites. The existence of natural strains in wild Anopheles (An.) mosquitoes, the vectors of malaria parasites, in an endosymbiotic relationship is still to be fully determined. Although Wolbachia has been reported to be present in wild populations of the An. gambiae complex, the primary vectors of malaria in Sub-Saharan Africa, Wolbachia DNA sequence density and infection frequencies are low. As most studies have used highly sensitive nested PCR as the only detection method, more robust evidence is required to determine whether Wolbachia strains are established as endosymbionts in Anopheles species. Techniques such as fluorescent in situ hybridization, microbiome sequencing, and Wolbachia whole genome sequencing have provided concrete evidence for genuine Wolbachia strains in two mosquito species: An. moucheti and An. demeilloni. In this chapter, the current methodology used to determine if resident strains exist in Anopheles mosquitoes will be reviewed, including both PCR- and non-PCR-based protocols.}, }
@article {pmid38006547, year = {2024}, author = {Kakumanu, ML and Hickin, ML and Schal, C}, title = {Detection, Quantification, and Elimination of Wolbachia in Bed Bugs.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2739}, number = {}, pages = {97-114}, pmid = {38006547}, issn = {1940-6029}, abstract = {Wolbachia is an obligatory nutritional symbiont of the common bed bug, Cimex lectularius, providing B-vitamins to its host. The biological significance of Wolbachia to bed bugs is investigated primarily by eliminating the symbiont with antibiotics, which is followed by confirmation with molecular assays. In this chapter, we describe a protocol for eliminating Wolbachia in bed bugs using the ansamycin antibiotic rifampicin (also known as rifampin) and three molecular methods to accurately detect and quantify the Wolbachia gene copies in bed bug samples. We describe the digital droplet PCR (ddPCR), a highly sensitive technique for absolute quantification of low abundance target genes, which has proven to be a valuable technique for confirmation of the elimination of Wolbachia.}, }
@article {pmid38006542, year = {2024}, author = {Fallon, AM}, title = {Wolbachia: Advancing into a Second Century.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2739}, number = {}, pages = {1-13}, pmid = {38006542}, issn = {1940-6029}, abstract = {Wolbachia pipientis had its scientific debut nearly a century ago and has recently emerged as a target for therapeutic treatment of filarial infections and an attractive tool for control of arthropod pests. Wolbachia was known as a biological entity before DNA was recognized as the molecule that carries the genetic information on which life depends, and before arthropods and nematodes were grouped in the Ecdysozoa. Today, some investigators consider Wolbachia the most abundant endosymbiont on earth, given the numbers of its hosts and its diverse mutualistic, commensal, and parasitic roles in their life histories. Recent advances in molecular technologies have revolutionized our understanding of Wolbachia and its associated reproductive phenotypes. New models have emerged for its investigation, and substantial progress has been made towards Wolbachia-based interventions in medicine and agriculture. Here I introduce Wolbachia, with a focus on aspects of its biology that are covered in greater detail in subsequent chapters.}, }
@article {pmid37999087, year = {2023}, author = {Lei, T and Luo, N and Song, C and Yu, J and Zhou, Y and Qi, X and Liu, Y}, title = {Comparative Genomics Reveals Three Genetic Groups of the Whitefly Obligate Endosymbiont Candidatus Portiera aleyrodidarum.}, journal = {Insects}, volume = {14}, number = {11}, pages = {}, pmid = {37999087}, issn = {2075-4450}, support = {32070481//National Natural Science Foundation of China/ ; CARS-23-C05//Earmarked Fund for China Agriculture Research System/ ; LY22C040003//Zhejiang Provincial Natural Science Foundation of China/ ; 21hb04//Science &amp; Technology Project of Taizhou/ ; 21nya17//Science &amp; Technology Project of Taizhou/ ; 1902gy23//Science &amp; Technology Project of Taizhou/ ; }, abstract = {Maternally inherited obligate endosymbionts codiverge with their invertebrate hosts and reflect their host's evolutionary history. Whiteflies (Hemiptera: Aleyrodidae) harbor one obligate endosymbiont, Candidatus Portiera aleyrodidarum (hereafter Portiera). Portiera was anciently acquired by whitefly and has been coevolving with its host ever since. Uncovering the divergence of endosymbionts provides a fundamental basis for inspecting the coevolutionary processes between the bacteria and their hosts. To illustrate the divergence of Portiera lineages across different whitefly species, we sequenced the Portiera genome from Aleyrodes shizuokensis and conducted a comparative analysis on the basic features and gene evolution with bacterial genomes from five whitefly genera, namely Aleurodicus, Aleyrodes, Bemisia, Pealius, and Trialeurodes. The results indicated that Portiera from Bemisia possessed significantly larger genomes, fewer coding sequences (CDSs), and a lower coding density. Their gene arrangement differed notably from those of other genera. The phylogeny of the nine Portiera lineages resembled that of their hosts. Moreover, the lineages were classified into three distinct genetic groups based on the genetic distance, one from Aleurodicus (Aleurodicinae), one from Bemisia (Aleyrodinae), and another from Aleyrodes, Pealius, and Trialeurrodes (Aleyrodinae). Synonymous and nonsynonymous rate analyses, parity rule 2 plot analyses, neutrality plot analyses, and effective number of codons analyses supported the distinction of the three genetic groups. Our results indicated that Portiera from distant hosts exhibit distinct genomic contents, implying codivergence between hosts and their endosymbionts. This work will enhance our understanding of coevolution between hosts and their endosymbionts.}, }
@article {pmid37995370, year = {2023}, author = {Strunov, A and Kirchner, S and Schindelar, J and Kruckenhauser, L and Haring, E and Kapun, M}, title = {Historic museum samples provide evidence for a recent replacement of Wolbachia types in European Drosophila melanogaster.}, journal = {Molecular biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/molbev/msad258}, pmid = {37995370}, issn = {1537-1719}, abstract = {Wolbachia is one of the most common bacterial endosymbionts, which is frequently found in numerous arthropods and nematode taxa. Wolbachia infections can have a strong influence on the evolutionary dynamics of their hosts since these bacteria are reproductive manipulators that affect the fitness and life history of their host species for their own benefit. Host-symbiont interactions with Wolbachia are perhaps best studied in the model organism Drosophila melanogaster, which is naturally infected with at least five different variants among which wMel and wMelCS are the most frequent ones. Comparisons of infection types between natural flies and long-term lab stocks have previously indicated that wMelCS represents the ancestral type, which was only very recently replaced by the nowadays dominant wMel in most natural populations. In this study, we took advantage of recently sequenced museum specimens of D. melanogaster that have been collected 90-200 years ago in Northern Europe to test this hypothesis. Our comparison to contemporary Wolbachia samples provides compelling support for the replacement hypothesis. Our analyses show that sequencing data from historic museum specimens and their bycatch are an emerging and unprecedented resource to address fundamental questions about evolutionary dynamics in host-symbiont interactions. However, we also identified contamination with DNA from crickets which resulted in co-contamination with cricket-specific Wolbachia in several samples. These results underpin the need for rigorous quality assessments of museomics datasets to account for contamination as a source of error which may strongly influence biological interpretations if it remains undetected.}, }
@article {pmid37980433, year = {2023}, author = {Sanches, P and De Moraes, CM and Mescher, MC}, title = {Endosymbionts modulate virus effects on aphid-plant interactions.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {37980433}, issn = {1751-7370}, abstract = {Vector-borne pathogens frequently modify traits of their primary hosts and vectors in ways that influence disease transmission. Such effects can themselves be altered by the presence of other microbial symbionts, yet we currently have limited understanding of these interactions. Here we show that effects of pea enation mosaic virus (PEMV) on interactions between host plants and aphid vectors are modulated by the presence of different aphid endosymbionts. In a series of laboratory assays, we found strong interactive effects of virus infection and endosymbionts on aphid metabolomic profiles, population growth, behavior, and virus transmission during aphid feeding. Furthermore, the strongest effects-and those predicted to favor virus transmission-were most apparent in aphid lines harboring particular endosymbionts. These findings show that virus effects on host-vector interactions can be strongly influenced by other microbial symbionts and suggest a potentially important role for such interactions in disease ecology and evolution.}, }
@article {pmid37978413, year = {2023}, author = {Pascar, J and Middleton, H and Dorus, S}, title = {Aedes aegypti microbiome composition covaries with the density of Wolbachia infection.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {255}, pmid = {37978413}, issn = {2049-2618}, abstract = {BACKGROUND: Wolbachia is a widespread bacterial endosymbiont that can inhibit vector competency when stably transinfected into the mosquito, Aedes aegypti, a primary vector of the dengue virus (DENV) and other arboviruses. Although a complete mechanistic understanding of pathogen blocking is lacking, it is likely to involve host immunity induction and resource competition between Wolbachia and DENV, both of which may be impacted by microbiome composition. The potential impact of Wolbachia transinfection on host fitness is also of importance given the widespread release of mosquitos infected with the Drosophila melanogaster strain of Wolbachia (wMel) in wild populations. Here, population-level genomic data from Ae. aegypti was surveyed to establish the relationship between the density of wMel infection and the composition of the host microbiome.<br><br>RESULTS: Analysis of genomic data from 172 Ae. aegypti females across six populations resulted in an expanded and quantitatively refined, species-level characterization of the bacterial, archaeal, and fungal microbiome. This included 844 species of bacteria across 23 phyla, of which 54 species were found to be ubiquitous microbiome members across these populations. The density of wMel infection was highly variable between individuals and negatively correlated with microbiome diversity. Network analyses revealed wMel as a hub comprised solely of negative interactions with other bacterial species. This contrasted with the large and highly interconnected network of other microbiome species that may represent members of the midgut microbiome community in this population.<br><br>CONCLUSION: Our bioinformatic survey provided a species-level characterization of Ae. aegypti microbiome composition and variation. wMel load varied substantially across populations and individuals and, importantly, wMel was a major hub of a negative interactions across the microbiome. These interactions may be an inherent consequence of heightened pathogen blocking in densely infected individuals or, alternatively, may result from antagonistic Wolbachia-incompatible bacteria that could impede the efficacy of wMel as a biological control agent in future applications. The relationship between wMel infection variation and the microbiome warrants further investigation in the context of developing wMel as a multivalent control agent against other arboviruses. Video Abstract.}, }
@article {pmid37974296, year = {2023}, author = {Sun, Y and Wang, M and Cao, L and Seim, I and Zhou, L and Chen, J and Wang, H and Zhong, Z and Chen, H and Fu, L and Li, M and Li, C and Sun, S}, title = {Mosaic environment-driven evolution of the deep-sea mussel Gigantidas platifrons bacterial endosymbiont.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {253}, pmid = {37974296}, issn = {2049-2618}, support = {2022QNLM030004//Marine S&amp;T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao)/ ; 2022QNLM030004//Marine S&amp;T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao)/ ; 2022QNLM030004//Marine S&amp;T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology (Qingdao)/ ; 42076091//National Natural Science Foundation of China/ ; 42030407//National Natural Science Foundation of China/ ; JSSCTD202142//Jiangsu Provincial Department of Technology/ ; XDB42020401//Strategic Priority Research Program of the Chinese Academy of Sciences/ ; ZDBS-LY-DQC032//Key Research Program of Frontier Sciences of the Chinese Academy of Sciences/ ; }, abstract = {BACKGROUND: The within-species diversity of symbiotic bacteria represents an important genetic resource for their environmental adaptation, especially for horizontally transmitted endosymbionts. Although strain-level intraspecies variation has recently been detected in many deep-sea endosymbionts, their ecological role in environmental adaptation, their genome evolution pattern under heterogeneous geochemical environments, and the underlying molecular forces remain unclear.<br><br>RESULTS: Here, we conducted a fine-scale metagenomic analysis of the deep-sea mussel Gigantidas platifrons bacterial endosymbiont collected from distinct habitats: hydrothermal vent and methane seep. Endosymbiont genomes were assembled using a pipeline that distinguishes within-species variation and revealed highly heterogeneous compositions in mussels from different habitats. Phylogenetic analysis separated the assemblies into three distinct environment-linked clades. Their functional differentiation follows a mosaic evolutionary pattern. Core genes, essential for central metabolic function and symbiosis, were conserved across all clades. Clade-specific genes associated with heavy metal resistance, pH homeostasis, and nitrate utilization exhibited signals of accelerated evolution. Notably, transposable elements and plasmids contributed to the genetic reshuffling of the symbiont genomes and likely accelerated adaptive evolution through pseudogenization and the introduction of new genes.<br><br>CONCLUSIONS: The current study uncovers the environment-driven evolution of deep-sea symbionts mediated by mobile genetic elements. Its findings highlight a potentially common and critical role of within-species diversity in animal-microbiome symbioses. Video Abstract.}, }
@article {pmid37970093, year = {2023}, author = {Awori, RM and Hendre, P and Amugune, NO}, title = {The genome of a steinernematid-associated Pseudomonas piscis bacterium encodes the biosynthesis of insect toxins.}, journal = {Access microbiology}, volume = {5}, number = {10}, pages = {}, pmid = {37970093}, issn = {2516-8290}, abstract = {Several species of soil-dwelling Steinernema nematodes are used in the biocontrol of crop pests, due to their natural capacity to kill diverse lepidopteran species. Although this insect-killing trait is known to be augmented by the nematodes' Xenorhabdus endosymbionts, the role of other steinernematid-associated bacterial genera in the nematode lifecycle remains unclear. This genomic study aimed to determine the potential of Pseudomonas piscis to contribute to the entomopathogenicity of its Steinernema host. Insect larvae were infected with three separate Steinernema cultures. From each of the three treatments, the prevalent bacteria in the haemocoel of cadavers, four days post-infection, were isolated. These three bacterial isolates were morphologically characterised. DNA was extracted from each of the three bacterial isolates and used for long-read genome sequencing and assembly. Assemblies were used to delineate species and identify genes that encode insect toxins, antimicrobials, and confer antibiotic resistance. We assembled three complete genomes. Through digital DNA-DNA hybridisation analyses, we ascertained that the haemocoels of insect cadavers previously infected with Steinernema sp. Kalro, Steinernema sp. 75, and Steinernema sp. 97 were dominated by Xenorhabdus griffiniae Kalro, Pseudomonas piscis 75, and X. griffiniae 97, respectively. X. griffiniae Kalro and X. griffiniae 97 formed a subspecies with other X. griffiniae symbionts of steinernematids from Kenya. P. piscis 75 phylogenetically clustered with pseudomonads that are characterised by high insecticidal activity. The P. piscis 75 genome encoded the production pathway of insect toxins such as orfamides and rhizoxins, antifungals such as pyrrolnitrin and pyoluteorin, and the broad-spectrum antimicrobial 2,4-diacetylphloroglucinol. The P. piscis 75 genome encoded resistance to over ten classes of antibiotics, including cationic lipopeptides. Steinernematid-associated P. piscis bacteria hence have the biosynthetic potential to contribute to nematode entomopathogenicity.}, }
@article {pmid37963163, year = {2023}, author = {Takasu, R and Yasuda, Y and Izu, T and Nakabachi, A}, title = {Diaphorin, a polyketide produced by a bacterial endosymbiont of the Asian citrus psyllid, adversely affects the in vitro gene expression with ribosomes from Escherichia coli and Bacillus subtilis.}, journal = {PloS one}, volume = {18}, number = {11}, pages = {e0294360}, pmid = {37963163}, issn = {1932-6203}, mesh = {Animals ; Bacillus subtilis/genetics/metabolism ; Escherichia coli/genetics/metabolism ; *Hemiptera/microbiology ; *Polyketides/pharmacology/metabolism ; *Citrus/microbiology ; *Gammaproteobacteria/metabolism ; Gene Expression ; Plant Diseases/microbiology ; *Rhizobiaceae/physiology ; }, abstract = {Diaphorin is a polyketide produced by "Candidatus Profftella armatura" (Gammaproteobacteria), an obligate mutualist of an important agricultural pest, the Asian citrus psyllid Diaphorina citri (Hemiptera). Our previous study demonstrated that diaphorin, at physiological concentrations in D. citri, inhibits the growth and cell division of Bacillus subtilis (Firmicutes) but promotes the growth and metabolic activity of Escherichia coli (Gammaproteobacteria). This unique property of diaphorin may aid microbial mutualism in D. citri, potentially affecting the transmission of "Candidatus Liberibacter spp." (Alphaproteobacteria), the pathogens of the most destructive citrus disease Huanglongbing. Moreover, this property may be exploited to promote microbes' efficiency in producing industrial materials. However, the mechanism underlying this activity is unknown. Diaphorin belongs to the family of pederin-type compounds, which inhibit protein synthesis in eukaryotes by binding to eukaryotic ribosomes. Therefore, as a first step to assess diaphorin's direct influence on bacterial gene expression, this study examined the effect of diaphorin on the in vitro translation using ribosomes of B. subtilis and E. coli, quantifying the production of the green fluorescent protein. The results showed that the gene expression involving B. subtilis and E. coli ribosomes along with five millimolar diaphorin was 29.6% and 13.1%, respectively, less active than the control. This suggests that the diaphorin's adverse effects on B. subtilis are attributed to, at least partly, its inhibitory effects on gene expression. Moreover, as ingredients of the translation system were common other than ribosomes, the greater inhibitory effects observed with the B. subtilis ribosome imply that the ribosome is among the potential targets of diaphorin. On the other hand, the results also imply that diaphorin's positive effects on E. coli are due to targets other than the core machinery of transcription and translation. This study demonstrated for the first time that a pederin congener affects bacterial gene expression.}, }
@article {pmid37961388, year = {2023}, author = {Karim, S and Zenzal, TJ and Beati, L and Sen, R and Adegoke, A and Kumar, D and Downs, LP and Keko, M and Nussbaum, A and Becker, DJ and Moore, FR}, title = {Ticks without borders: Microbial communities of immature Neotropical tick species parasitizing migratory landbirds along northern Gulf of Mexico.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.10.22.563347}, pmid = {37961388}, abstract = {The long-distance, seasonal migrations of birds make them an effective ecological bridge for the movement of ticks. The introduction of exotic tick species to new geographical regions can lead to the emergence of novel tick-borne pathogens or the re-emergence of previously eradicated ones. This study assessed the prevalence of exotic tick species parasitizing resident, short-distance, and long-distance songbirds during spring and autumn at stopover sites in the northern Gulf of Mexico using the mitochondrial 12S rDNA gene. Birds were captured for tick collection from six different sites from late August to early November in both 2018 and 2019. The highest number of ticks were collected in the 2019 season. Most ticks were collected off the Yellow-breasted Chat (Icteria virens) and Common Yellowthroat (Geothlypis trichas), and 54% of the total ticks collected were from Grand Chenier, LA. A high throughput 16S ribosomal RNA sequencing approach was followed to characterize the microbial communities and identify pathogenic microbes in all tick samples. Tick microbial communities, diversity, and community structure were determined using quantitative insight into microbial ecology (QIIME). The sparse correlations for compositional data (SparCC) approach was then used to construct microbial network maps and infer microbial correlations. A total of 421 individual ticks in the genera Amblyomma, Haemaphysalis, and Ixodes were recorded from 28 songbird species, of which Amblyomma and Amblyomma longirostre was the most abundant tick genus and species, respectively. Microbial profiles showed that Proteobacteria was the most abundant phylum. The most abundant bacteria include the pathogenic Rickettsia and endosymbiont Francisella, Candidatus Midichloria, and Spiroplasma . BLAST analysis and phylogenetic reconstruction of the Rickettsia sequences revealed the highest similarities to pathogenic spotted and non-spotted fever groups, including R . buchneri, R. conorii, R. prowazekii, R. bellii, R. australis, R. parkeri, R. monacensis, and R. monteiroi . Permutation multivariate analysis of variance revealed that the relative abundance of Francisella and Rickettsia drives microbial patterns across the tick genera. We also observed a higher percentage of positive correlations in microbe-microbe interactions among members of the microbial communities. Network analysis suggested a negative correlation between a) Francisella and Rickettsia and, b) Francisella and Cutibacterium . Lastly, mapping the distributions of bird species parasitized during spring migrations highlighted geographic hotspots where migratory songbirds could disperse ticks and their pathogens at stopover sites or upon arrival to their breeding grounds, the latter showing means dispersal distances from 421-5003 kilometers. These findings strongly highlight the potential role of migratory birds in the epidemiology of tick-borne pathogens.}, }
@article {pmid37955420, year = {2023}, author = {Whittle, M and Bonsall, MB and Barreaux, AMG and Ponton, F and English, S}, title = {A theoretical model for host-controlled regulation of symbiont density.}, journal = {Journal of evolutionary biology}, volume = {}, number = {}, pages = {}, doi = {10.1111/jeb.14246}, pmid = {37955420}, issn = {1420-9101}, abstract = {There is growing empirical evidence that animal hosts actively control the density of their mutualistic symbionts according to their requirements. Such active regulation can be facilitated by compartmentalization of symbionts within host tissues, which confers a high degree of control of the symbiosis to the host. Here, we build a general theoretical framework to predict the underlying ecological drivers and evolutionary consequences of host-controlled endosymbiont density regulation for a mutually obligate association between a host and a compartmentalized, vertically transmitted symbiont. Building on the assumption that the costs and benefits of hosting a symbiont population increase with symbiont density, we use state-dependent dynamic programming to determine an optimal strategy for the host, i.e., that which maximizes host fitness, when regulating the density of symbionts. Simulations of active host-controlled regulation governed by the optimal strategy predict that the density of the symbiont should converge to a constant level during host development, and following perturbation. However, a similar trend also emerges from alternative strategies of symbiont regulation. The strategy which maximizes host fitness also promotes symbiont fitness compared to alternative strategies, suggesting that active host-controlled regulation of symbiont density could be adaptive for the symbiont as well as the host. Adaptation of the framework allowed the dynamics of symbiont density to be predicted for other host-symbiont ecologies, such as for non-essential symbionts, demonstrating the versatility of this modelling approach.}, }
@article {pmid37953792, year = {2023}, author = {Furtado, DP and Vieira, EA and Nascimento, WF and Inagaki, KY and Bleuel, J and Alves, MAZ and Longo, GO and Oliveira, LS}, title = {#DeOlhoNosCorais: a polygonal annotated dataset to optimize coral monitoring.}, journal = {PeerJ}, volume = {11}, number = {}, pages = {e16219}, pmid = {37953792}, issn = {2167-8359}, abstract = {Corals are colonial animals within the Phylum Cnidaria that form coral reefs, playing a significant role in marine environments by providing habitat for fish, mollusks, crustaceans, sponges, algae, and other organisms. Global climate changes are causing more intense and frequent thermal stress events, leading to corals losing their color due to the disruption of a symbiotic relationship with photosynthetic endosymbionts. Given the importance of corals to the marine environment, monitoring coral reefs is critical to understanding their response to anthropogenic impacts. Most coral monitoring activities involve underwater photographs, which can be costly to generate on large spatial scales and require processing and analysis that may be time-consuming. The Marine Ecology Laboratory (LECOM) at the Federal University of Rio Grande do Norte (UFRN) developed the project "#DeOlhoNosCorais" which encourages users to post photos of coral reefs on their social media (Instagram) using this hashtag, enabling people without previous scientific training to contribute to coral monitoring. The laboratory team identifies the species and gathers information on coral health along the Brazilian coast by analyzing each picture posted on social media. To optimize this process, we conducted baseline experiments for image classification and semantic segmentation. We analyzed the classification results of three different machine learning models using the Local Interpretable Model-agnostic Explanations (LIME) algorithm. The best results were achieved by combining EfficientNet for feature extraction and Logistic Regression for classification. Regarding semantic segmentation, the U-Net Pix2Pix model produced a pixel-level accuracy of 86%. Our results indicate that this tool can enhance image selection for coral monitoring purposes and open several perspectives for improving classification performance. Furthermore, our findings can be expanded by incorporating other datasets to create a tool that streamlines the time and cost associated with analyzing coral reef images across various regions.}, }
@article {pmid37952351, year = {2023}, author = {El Hamss, H and Maruthi, MN and Omongo, CA and Wang, HL and van Brunschot, S and Colvin, J and Delatte, H}, title = {Microbiome diversity and composition in Bemisia tabaci SSA1-SG1 whitefly are influenced by their host's life stage.}, journal = {Microbiological research}, volume = {278}, number = {}, pages = {127538}, doi = {10.1016/j.micres.2023.127538}, pmid = {37952351}, issn = {1618-0623}, abstract = {Within the Bemisia tabaci group of cryptic whitefly species, many are damaging agricultural pests and plant-virus vectors, conferring upon this group the status of one of the world's top 100 most invasive and destructive species, affecting farmers' income and threatening their livelihoods. Studies on the microbiome of whitefly life stages are scarce, although their composition and diversity greatly influence whitefly fitness and development. We used high-throughput sequencing to understand microbiome diversity in different developmental stages of the B. tabaci sub-Saharan Africa 1 (SSA1-SG1) species of the whitefly from Uganda. Endosymbionts (Portiera, Arsenophonus, Wolbachia, and Hemipteriphilus were detected but excluded from further statistical analysis as they were not influenced by life stage using Permutational Multivariate Analysis of Variance Using Distance Matrices (ADONIS, p = 0.925 and Bray, p = 0.903). Our results showed significant differences in the meta microbiome composition in different life stages of SSA1-SG1. The diversity was significantly higher in eggs (Shannon, p = 0.024; Simpson, p = 0.047) than that in nymphs and pupae, while the number of microbial species observed by the amplicon sequence variant (ASV) was not significant (n(ASV), p = 0.094). At the phylum and genus levels, the dominant constituents in the microbiome changed significantly during various developmental stages, with Halomonas being present in eggs, whereas Bacillus and Caldalkalibacillus were consistently found across all life stages. These findings provide the first description of differing meta microbiome diversity in the life stage of whiteflies, suggesting their putative role in whitefly development.}, }
@article {pmid37952050, year = {2023}, author = {Miyagishima, SY}, title = {Taming the perils of photosynthesis by eukaryotes: constraints on endosymbiotic evolution in aquatic ecosystems.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {1150}, pmid = {37952050}, issn = {2399-3642}, support = {20H00477//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 22682397//MEXT | Japan Science and Technology Agency (JST)/ ; }, abstract = {An ancestral eukaryote acquired photosynthesis by genetically integrating a cyanobacterial endosymbiont as the chloroplast. The chloroplast was then further integrated into many other eukaryotic lineages through secondary endosymbiotic events of unicellular eukaryotic algae. While photosynthesis enables autotrophy, it also generates reactive oxygen species that can cause oxidative stress. To mitigate the stress, photosynthetic eukaryotes employ various mechanisms, including regulating chloroplast light absorption and repairing or removing damaged chloroplasts by sensing light and photosynthetic status. Recent studies have shown that, besides algae and plants with innate chloroplasts, several lineages of numerous unicellular eukaryotes engage in acquired phototrophy by hosting algal endosymbionts or by transiently utilizing chloroplasts sequestrated from algal prey in aquatic ecosystems. In addition, it has become evident that unicellular organisms engaged in acquired phototrophy, as well as those that feed on algae, have also developed mechanisms to cope with photosynthetic oxidative stress. These mechanisms are limited but similar to those employed by algae and plants. Thus, there appear to be constraints on the evolution of those mechanisms, which likely began by incorporating photosynthetic cells before the establishment of chloroplasts by extending preexisting mechanisms to cope with oxidative stress originating from mitochondrial respiration and acquiring new mechanisms.}, }
@article {pmid37949964, year = {2023}, author = {Bickerstaff, JRM and Jordal, BH and Riegler, M}, title = {Two sympatric lineages of Australian Cnestus solidus share Ambrosiella symbionts but not Wolbachia.}, journal = {Heredity}, volume = {}, number = {}, pages = {}, pmid = {37949964}, issn = {1365-2540}, abstract = {Sympatric lineages of inbreeding species provide an excellent opportunity to investigate species divergence patterns and processes. Many ambrosia beetle lineages (Curculionidae: Scolytinae) reproduce by predominant inbreeding through sib mating in nests excavated in woody plant parts wherein they cultivate symbiotic ambrosia fungi as their sole source of nutrition. The Xyleborini ambrosia beetle species Cnestus solidus and Cnestus pseudosolidus are sympatrically distributed across eastern Australia and have overlapping morphological variation. Using multilocus sequencing analysis of individuals collected from 19 sites spanning their sympatric distribution, we assessed their phylogenetic relationships, taxonomic status and microbial symbionts. We found no genetic differentiation between individuals morphologically identified as C. solidus and C. pseudosolidus confirming previous suggestions that C. pseudosolidus is synonymous to C. solidus. However, within C. solidus we unexpectedly discovered the sympatric coexistence of two morphologically indistinguishable but genetically distinct lineages with small nuclear yet large mitochondrial divergence. At all sites except one, individuals of both lineages carried the same primary fungal symbiont, a new Ambrosiella species, indicating that fungal symbiont differentiation may not be involved in lineage divergence. One strain of the maternally inherited bacterial endosymbiont Wolbachia was found at high prevalence in individuals of the more common lineage but not in the other, suggesting that it may influence host fitness. Our data suggest that the two Australian Cnestus lineages diverged allopatrically, and one lineage then acquired Wolbachia. Predominant inbreeding and Wolbachia infection may have reinforced reproductive barriers between these two lineages after their secondary contact contributing to their current sympatric distribution.}, }
@article {pmid37948354, year = {2023}, author = {Hussain, M and Zhong, Y and Tao, T and Xiu, B and Ye, F and Gao, J and Mao, R}, title = {Effect of tree height and spraying methods on Diaphorina citri kuwayama endosymbionts in the context of Huanglongbing disease management in citrus orchards.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7880}, pmid = {37948354}, issn = {1526-4998}, abstract = {BACKGROUND: Huanglongbing (caused by Candidatus Liberibacter asiaticus) is the most damaging disease of citrus around the world. This study investigated the effects of citrus tree age on Diaphorina citri Kuwayama mortality, endosymbiont responses, and Huanglongbing distribution.<br><br>RESULTS: The results reveal that the age of citrus trees plays a significant role in psyllid mortality. Notably, four-year-old plants exhibited higher psyllid mortality (31.50%) compared to thirteen-year-old trees (9.10% and 0.09%, respectively). Our findings also revealed that psyllids from both 4 and 13-year-old citrus trees carried Candidatus Carsonella ruddii species and Wolbachia, the primary and secondary endosymbionts, respectively. Surprisingly, infection rates of these endosymbionts remained consistent across different age groups, as confirmed by qPCR analysis. Furthermore, our study highlights the significance of tree height as a proxy for tree age in influencing Huanglongbing occurrence. Specifically, 4-year-old trees subjected to the US-SMART mechanical sprayer for citrus psyllid control demonstrated effective disease management compared to 13-year-old trees treated with handheld gun sprayers. Additionally, the investigation explored the impact of tree height on HLB distribution. In four-year-old trees, no significant correlation between HLB disease and tree height was observed, potentially due to effective spray coverage. However, in thirteen-year-old trees, a negative correlation between tree height and HLB disease was evident.<br><br>CONCLUSION: This research provides valuable insights into the complex interaction between citrus tree age, psyllid endosymbionts responses, and HLB distribution. These results emphasize effective HLB management strategies, especially in orchards with diverse tree age populations, ultimately contributing to the long-term sustainability of citrus cultivation. This article is protected by copyright. All rights reserved.}, }
@article {pmid37944675, year = {2023}, author = {Chaves-Olarte, E and Meza-Torres, J and Herrera-Rodríguez, F and Lizano-González, E and Suárez-Esquivel, M and Baker, KS and Rivas-Solano, O and Ruiz-Villalobos, N and Villalta-Romero, F and Cheng, HP and Walker, GC and Cloeckaert, A and Thomson, NR and Frisan, T and Moreno, E and Guzmán-Verri, C}, title = {A sensor histidine kinase from a plant-endosymbiont bacterium restores the virulence of a mammalian intracellular pathogen.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106442}, doi = {10.1016/j.micpath.2023.106442}, pmid = {37944675}, issn = {1096-1208}, abstract = {Alphaproteobacteria include organisms living in close association with plants or animals. This interaction relies partly on orthologous two-component regulatory systems (TCS), with sensor and regulator proteins modulating the expression of conserved genes related to symbiosis/virulence. We assessed the ability of the exoS[+]Sm gene, encoding a sensor protein from the plant endosymbiont Sinorhizobium meliloti to substitute its orthologous bvrS in the related animal/human pathogen Brucella abortus. ExoS phosphorylated the B. abortus regulator BvrR in vitro and in cultured bacteria, showing conserved biological function. Production of ExoS in a B. abortus bvrS mutant reestablished replication in host cells and the capacity to infect mice. Bacterial outer membrane properties, the production of the type IV secretion system VirB, and its transcriptional regulators VjbR and BvrR were restored as compared to parental B. abortus. These results indicate that conserved traits of orthologous TCS from bacteria living in and sensing different environments are sufficient to achieve phenotypic plasticity and support bacterial survival. The knowledge of bacterial genetic networks regulating host interactions allows for an understanding of the subtle differences between symbiosis and parasitism. Rewiring these networks could provide new alternatives to control and prevent bacterial infection.}, }
@article {pmid37938758, year = {2022}, author = {Luo, H and Wang, J and Goes, JI and Gomes, HDR and Al-Hashmi, K and Tobias, C and Koerting, C and Lin, S}, title = {A grazing-driven positive nutrient feedback loop and active sexual reproduction underpin widespread Noctiluca green tides.}, journal = {ISME communications}, volume = {2}, number = {1}, pages = {103}, pmid = {37938758}, issn = {2730-6151}, support = {4980.01//Gordon and Betty Moore Foundation (Gordon E. and Betty I. Moore Foundation)/ ; 2019983//Gordon and Betty Moore Foundation (Gordon E. and Betty I. Moore Foundation)/ ; 42276096//National Natural Science Foundation of China (National Science Foundation of China)/ ; NNX17AG66G-ECO4CAST//National Aeronautics and Space Administration (NASA)/ ; CMS-80NSSC20K0014//National Aeronautics and Space Administration (NASA)/ ; }, abstract = {The mixoplankton green Noctiluca scintillans (gNoctiluca) is known to form extensive green tides in tropical coastal ecosystems prone to eutrophication. In the Arabian Sea, their recent appearance and annual recurrence have upended an ecosystem that was once exclusively dominated by diatoms. Despite evidence of strong links to eutrophication, hypoxia and warming, the mechanisms underlying outbreaks of this mixoplanktonic dinoflagellate remain uncertain. Here we have used eco-physiological measurements and transcriptomic profiling to ascribe gNoctiluca's explosive growth during bloom formation to the form of sexual reproduction that produces numerous gametes. Rapid growth of gNoctiluca coincided with active ammonium and phosphate release from gNoctiluca cells, which exhibited high transcriptional activity of phagocytosis and metabolism generating ammonium. This grazing-driven nutrient flow ostensibly promotes the growth of phytoplankton as prey and offers positive support successively for bloom formation and maintenance. We also provide the first evidence that the host gNoctiluca cell could be manipulating growth of its endosymbiont population in order to exploit their photosynthetic products and meet critical energy needs. These findings illuminate gNoctiluca's little known nutritional and reproductive strategies that facilitate its ability to form intense and expansive gNoctiluca blooms to the detriment of regional water, food and the socio-economic security in several tropical countries.}, }
@article {pmid37936139, year = {2023}, author = {Hakobyan, A and Velte, S and Sickel, W and Quandt, D and Stoll, A and Knief, C}, title = {Tillandsia landbeckii phyllosphere and laimosphere as refugia for bacterial life in a hyperarid desert environment.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {246}, pmid = {37936139}, issn = {2049-2618}, support = {268236062//Deutsche Forschungsgemeinschaft/ ; 268236062//Deutsche Forschungsgemeinschaft/ ; 268236062//Deutsche Forschungsgemeinschaft/ ; 268236062//Deutsche Forschungsgemeinschaft/ ; 268236062//Deutsche Forschungsgemeinschaft/ ; 268236062//Deutsche Forschungsgemeinschaft/ ; }, abstract = {BACKGROUND: The lack of water is a major constraint for microbial life in hyperarid deserts. Consequently, the abundance and diversity of microorganisms in common habitats such as soil are strongly reduced, and colonization occurs primarily by specifically adapted microorganisms that thrive in particular refugia to escape the harsh conditions that prevail in these deserts. We suggest that plants provide another refugium for microbial life in hyperarid deserts. We studied the bacterial colonization of Tillandsia landbeckii (Bromeliaceae) plants, which occur in the hyperarid regions of the Atacama Desert in Chile, one of the driest and oldest deserts on Earth.<br><br>RESULTS: We detected clear differences between the bacterial communities being plant associated to those of the bare soil surface (PERMANOVA, R[2]&#x2009;=&#x2009;0.187, p&#x2009;=&#x2009;0.001), indicating that Tillandsia plants host a specific bacterial community, not only dust-deposited cells. Moreover, the bacterial communities in the phyllosphere were distinct from those in the laimosphere, i.e., on buried shoots (R[2]&#x2009;=&#x2009;0.108, p&#x2009;=&#x2009;0.001), indicating further habitat differentiation within plant individuals. The bacterial taxa detected in the phyllosphere are partly well-known phyllosphere colonizers, but in addition, some rather unusual taxa (subgroup2 Acidobacteriae, Acidiphilum) and insect endosymbionts (Wolbachia, "Candidatus Uzinura") were found. The laimosphere hosted phyllosphere-associated as well as soil-derived taxa. The phyllosphere bacterial communities showed biogeographic patterns across the desert (R[2]&#x2009;=&#x2009;0.331, p&#x2009;=&#x2009;0.001). These patterns were different and even more pronounced in the laimosphere (R[2]&#x2009;=&#x2009;0.467, p&#x2009;=&#x2009;0.001), indicating that different factors determine community assembly in the two plant compartments. Furthermore, the phyllosphere microbiota underwent temporal changes (R[2]&#x2009;=&#x2009;0.064, p&#x2009;=&#x2009;0.001).<br><br>CONCLUSIONS: Our data demonstrate that T. landbeckii plants host specific bacterial communities in the phyllosphere as well as in the laimosphere. Therewith, these plants provide compartment-specific refugia for microbial life in hyperarid desert environments. The bacterial communities show biogeographic patterns and temporal variation, as known from other plant microbiomes, demonstrating environmental responsiveness and suggesting that bacteria inhabit these plants as viable microorganisms. Video Abstract.}, }
@article {pmid37930120, year = {2023}, author = {Henry, E and Carlson, CR and Kuo, YW}, title = {Candidatus Kirkpatrickella diaphorinae gen. nov., sp. nov., an uncultured endosymbiont identified in a population of Diaphorina citri from Hawaii.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {73}, number = {11}, pages = {}, doi = {10.1099/ijsem.0.006111}, pmid = {37930120}, issn = {1466-5034}, mesh = {Animals ; Symbiosis ; Hawaii ; RNA, Ribosomal, 16S/genetics ; Phylogeny ; DNA, Bacterial/genetics ; Sequence Analysis, DNA ; Bacterial Typing Techniques ; Base Composition ; Fatty Acids/chemistry ; Bacteria/genetics ; *Hemiptera/microbiology ; *Citrus ; }, abstract = {Diaphorina citri is the hemipteran pest and vector of a devastating bacterial pathogen of citrus worldwide. In addition to the two core bacterial endosymbionts of D. citri, Candidatus Carsonella ruddii and Candidatus Profftella armatura, the genome of a novel endosymbiont and as of yet undescribed microbe was discovered in a Hawaiian D. citri population through deep sequencing of multiple D. citri populations. Found to be closely related to the genus Asaia in the family Acetobacteraceae by 16S rRNA gene sequence analysis, it forms a sister clade along with other insect-associated 16S rRNA gene sequences from uncultured bacterium found associated with Aedes koreicus and Sogatella furcifera. Multilocus sequence analysis confirmed the phylogenetic placement sister to the Asaia clade. Despite the culturable Asaia clade being the closest phylogenetic neighbour, attempts to culture this newly identified bacterial endosymbiont were unsuccessful. On the basis of these distinct genetic differences, the novel endosymbiont is proposed to be classified into a candidate genus and species 'Candidatus Kirkpatrickella diaphorinae'. The full genome was deposited in GenBank (accession number CP107052; prokaryotic 16S rRNA OP600170).}, }
@article {pmid37921460, year = {2023}, author = {Zhang, Y and Liu, S and Huang, X-y and Zi, H-b and Gao, T and Ji, R-j and Sheng, J and Zhi, D and Zhang, Y-l and Gong, C-m and Yang, Y-q}, title = {Altitude as a key environmental factor shaping microbial communities of tea green leafhoppers (Matsumurasca onukii).}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0100923}, doi = {10.1128/spectrum.01009-23}, pmid = {37921460}, issn = {2165-0497}, abstract = {The tea green leafhopper, Matsumurasca onukii Matsuda, is the most destructive insect pest of tea plantations in East Asia. While several microbes in M. onukii have been characterized, the microbial community compositions in wild M. onukii populations and the environmental factors that shape them are mostly unknown. In this study, M. onukii populations were collected from major tea growing regions in China. Following high-throughput sequencing of 16S rRNA gene fragments for bacteria and the internal transcribed spacer region for fungi, association analyses were performed within the microbial communities associated with M. onukii and their environmental drivers. We found that the bacterial community structures differed in various regions, and the abundance of dominant bacteria such as Wolbachia, Pseudomonas, Acinetobacter, Pantoea, Enterobacter, and Methylobacterium varied widely. Moreover, wild populations of M. onukii can be infected with facultative symbionts from six genera (Wolbachia, Rickettsia, Asaia, Serratia, Arsenophonus, and Cardinium) with divergent relative abundances. Correlation analysis indicated that altitude was a key environmental factor that shaped bacterial communities of M. onukii. Furthermore, longitude, temperature, and rainfall are also significantly correlated with the bacterial communities. The fungal communities of M. onukii populations were dominated by Ascomycota and Basidiomycota, of which most genera are considered to be plant endophytes or plant pathogens, such as Cladosporium, Fusarium, Alternaria, and Gibberella. We demonstrated that M. onukii carry a complex and variable microbial community, which is influenced by altitude as well as climate-related factors. Our results provide novel insights into the bacteria and fungi of M. onukii.IMPORTANCEHost-associated microbial communities play an important role in the fitness of insect hosts. However, the factors shaping microbial communities in wild populations, including environmental factors and interactions among microbial species, remain largely unknown. The tea green leafhopper has a wide geographical distribution and is highly adaptable, providing a suitable model for studying the effect of ecological drivers on microbiomes. This is the first large-scale culture-independent study investigating the microbial communities of M. onukii sampled from different locations. Altitude as a key environmental factor may have shaped microbial communities of M. onukii by affecting the relative abundance of endosymbionts, especially Wolbachia. The results of this study, therefore, offer not only an in-depth view of the microbial diversity of this species but also an insight into the influence of environmental factors.}, }
@article {pmid37914998, year = {2023}, author = {Liu, W and Xia, X and Hoffmann, AA and Ding, Y and Fang, JC and Yu, H}, title = {Evolution of Wolbachia reproductive and nutritional mutualism: insights from the genomes of two novel strains that double infect the pollinator of dioecious Ficus hirta.}, journal = {BMC genomics}, volume = {24}, number = {1}, pages = {657}, pmid = {37914998}, issn = {1471-2164}, support = {2021A1515110981//Guangdong Basic and Applied Basic Research Foundation/ ; 2022ZB773//Jiangsu Funding Program for Excellent Postdoctoral Talent/ ; 2022VBA0002//The Chinese Academy of Sciences PIFI Fellowship for Visiting Scientists/ ; 2023YFE0100540//National Key R &amp; D Program of China/ ; 202206010058//Guangzhou Collaborative Innovation Center on Science-tech of Ecology and Landscape/ ; }, mesh = {*Ficus/genetics ; *Wolbachia/genetics ; Biotin/genetics ; Symbiosis/genetics ; Phylogeny ; DNA Transposable Elements/genetics ; Multilocus Sequence Typing ; Prophages/genetics ; Reproduction ; }, abstract = {Wolbachia is a genus of maternally inherited endosymbionts that can affect reproduction of their hosts and influence metabolic processes. The pollinator, Valisia javana, is common in the male syconium of the dioecious fig Ficus hirta. Based on a high-quality chromosome-level V. javana genome with PacBio long-read and Illumina short-read sequencing, we discovered a sizeable proportion of Wolbachia sequences and used these to assemble two novel Wolbachia strains belonging to supergroup A. We explored its phylogenetic relationship with described Wolbachia strains based on MLST sequences and the possibility of induction of CI (cytoplasmic incompatibility) in this strain by examining the presence of cif genes known to be responsible for CI in other insects. We also identified mobile genetic elements including prophages and insertion sequences, genes related to biotin synthesis and metabolism. A total of two prophages and 256 insertion sequences were found. The prophage WOjav1 is cryptic (structure incomplete) and WOjav2 is relatively intact. IS5 is the dominant transposon family. At least three pairs of type I cif genes with three copies were found which may cause strong CI although this needs experimental verification; we also considered possible nutritional effects of the Wolbachia by identifying genes related to biotin production, absorption and metabolism. This study provides a resource for further studies of Wolbachia-pollinator-host plant interactions.}, }
@article {pmid37914705, year = {2023}, author = {Rädecker, N and Escrig, S and Spangenberg, JE and Voolstra, CR and Meibom, A}, title = {Coupled carbon and nitrogen cycling regulates the cnidarian-algal symbiosis.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {6948}, pmid = {37914705}, issn = {2041-1723}, support = {205321_212614//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung (Swiss National Science Foundation)/ ; }, abstract = {Efficient nutrient recycling underpins the ecological success of cnidarian-algal symbioses in oligotrophic waters. In these symbioses, nitrogen limitation restricts the growth of algal endosymbionts in hospite and stimulates their release of photosynthates to the cnidarian host. However, the mechanisms controlling nitrogen availability and their role in symbiosis regulation remain poorly understood. Here, we studied the metabolic regulation of symbiotic nitrogen cycling in the sea anemone Aiptasia by experimentally altering labile carbon availability in a series of experiments. Combining [13]C and [15]N stable isotope labeling experiments with physiological analyses and NanoSIMS imaging, we show that the competition for environmental ammonium between the host and its algal symbionts is regulated by labile carbon availability. Light regimes optimal for algal photosynthesis increase carbon availability in the holobiont and stimulate nitrogen assimilation in the host metabolism. Consequently, algal symbiont densities are lowest under optimal environmental conditions and increase toward the lower and upper light tolerance limits of the symbiosis. This metabolic regulation promotes efficient carbon recycling in a stable symbiosis across a wide range of environmental conditions. Yet, the dependence on resource competition may favor parasitic interactions, explaining the instability of the cnidarian-algal symbiosis as environmental conditions in the Anthropocene shift towards its tolerance limits.}, }
@article {pmid37914031, year = {2023}, author = {Grossi, AA and Tian, C and Ren, M and Zou, F and Gustafsson, DR}, title = {Co-phylogeny of a hyper-symbiotic system: endosymbiotic bacteria (Gammaproteobacteria), chewing lice (Insecta: Phthiraptera) and birds (Passeriformes).}, journal = {Molecular phylogenetics and evolution}, volume = {}, number = {}, pages = {107957}, doi = {10.1016/j.ympev.2023.107957}, pmid = {37914031}, issn = {1095-9513}, abstract = {Chewing lice are hosts to endosymbiotic bacteria as well as themselves being permanent parasites. This offers a unique opportunity to examine the cophylogenetic relationships between three ecologically interconnected organismal groups: birds, chewing lice, and bacteria. Here, we examine the cophylogenetic relationships between lice in the genus Guimaraesiella Eichler, 1949, their endosymbiotic Sodalis-allied bacteria, and a range of bird species from across South China. Both event and distance-based cophylogenetic analyses were explored to compare phylogenies of the three organismal groups. Pair-wise comparisons between lice-endosymbionts and bird-endosymbionts indicated that their evolutionary histories are not independent. However, comparisons between lice and birds, showed mixed results; the distance-based method of ParaFit indicated that their evolutionary histories are not independent, while the event-based method of Jane indicated that their phylogenies were no more congruent than expected by chance. Notably, louse host-switching does not seem to have affected bacterial strains, as conspecific lice sampled from distantly related hosts share bacteria belonging to the same clade.}, }
@article {pmid37907954, year = {2023}, author = {Pfarr, KM and Krome, AK and Al-Obaidi, I and Batchelor, H and Vaillant, M and Hoerauf, A and Opoku, NO and Kuesel, AC}, title = {The pipeline for drugs for control and elimination of neglected tropical diseases: 2. Oral anti-infective drugs and drug combinations for off-label use.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {394}, pmid = {37907954}, issn = {1756-3305}, support = {RIA2019PD-2880//European and Developing Countries Clinical Trials Partnership/ ; INTER/EDCTP/19/14338294/MiniMox/Vaillant//Fonds National de la Recherche Luxembourg/ ; }, mesh = {Humans ; *Ivermectin/therapeutic use ; Rifampin ; Doxycycline ; Fluconazole ; Off-Label Use ; *Anti-Infective Agents/therapeutic use ; Drug Combinations ; Neglected Diseases/drug therapy/prevention &amp; control ; }, abstract = {In its 'Road map for neglected tropical diseases 2021-2030', the World Health Organization outlined its targets for control and elimination of neglected tropical diseases (NTDs) and research needed to achieve them. For many NTDs, this includes research for new treatment options for case management and/or preventive chemotherapy. Our review of small-molecule anti-infective drugs recently approved by a stringent regulatory authority (SRA) or in at least Phase 2 clinical development for regulatory approval showed that this pipeline cannot deliver all new treatments needed. WHO guidelines and country policies show that drugs may be recommended for control and elimination for NTDs for which they are not SRA approved (i.e. for 'off-label' use) if efficacy and safety data for the relevant NTD are considered sufficient by WHO and country authorities. Here, we are providing an overview of clinical research in the past 10 years evaluating the anti-infective efficacy of oral small-molecule drugs for NTD(s) for which they are neither SRA approved, nor included in current WHO strategies nor, considering the research sponsors, likely to be registered with a SRA for that NTD, if found to be effective and safe. No such research has been done for yaws, guinea worm, Trypanosoma brucei gambiense human African trypanosomiasis (HAT), rabies, trachoma, visceral leishmaniasis, mycetoma, T. b. rhodesiense HAT, echinococcosis, taeniasis/cysticercosis or scabies. Oral drugs evaluated include sparfloxacin and acedapsone for leprosy; rifampicin, rifapentin and moxifloxacin for onchocerciasis; imatinib and levamisole for loiasis; itraconazole, fluconazole, ketoconazole, posaconazole, ravuconazole and disulfiram for Chagas disease, doxycycline and rifampicin for lymphatic filariasis; arterolane, piperaquine, artesunate, artemether, lumefantrine and mefloquine for schistosomiasis; ivermectin, tribendimidine, pyrantel, oxantel and nitazoxanide for soil-transmitted helminths including strongyloidiasis; chloroquine, ivermectin, balapiravir, ribavirin, celgosivir, UV-4B, ivermectin and doxycycline for dengue; streptomycin, amoxicillin, clavulanate for Buruli ulcer; fluconazole and isavuconazonium for mycoses; clarithromycin and dapsone for cutaneous leishmaniasis; and tribendimidine, albendazole, mebendazole and nitazoxanide for foodborne trematodiasis. Additional paths to identification of new treatment options are needed. One promising path is exploitation of the worldwide experience with 'off-label' treatment of diseases with insufficient treatment options as pursued by the 'CURE ID' initiative.}, }
@article {pmid37906220, year = {2023}, author = {He, LS and Qi, Y and Allard, CAH and Valencia-Montoya, WA and Krueger, SP and Weir, K and Seminara, A and Bellono, NW}, title = {Molecular tuning of sea anemone stinging.}, journal = {eLife}, volume = {12}, number = {}, pages = {}, pmid = {37906220}, issn = {2050-084X}, support = {R35GM142697/NH/NIH HHS/United States ; 101002724 RIDING/ERC_/European Research Council/International ; R01DC018789/NH/NIH HHS/United States ; }, abstract = {Jellyfish and sea anemones fire single-use, venom-covered barbs to immobilize prey or predators. We previously showed that the anemone Nematostella vectensis uses a specialized voltage-gated calcium (CaV) channel to trigger stinging in response to synergistic prey-derived chemicals and touch (Weir et al., 2020). Here, we use experiments and theory to find that stinging behavior is suited to distinct ecological niches. We find that the burrowing anemone Nematostella uses uniquely strong CaV inactivation for precise control of predatory stinging. In contrast, the related anemone Exaiptasia diaphana inhabits exposed environments to support photosynthetic endosymbionts. Consistent with its niche, Exaiptasia indiscriminately stings for defense and expresses a CaV splice variant that confers weak inactivation. Chimeric analyses reveal that CaVβ subunit adaptations regulate inactivation, suggesting an evolutionary tuning mechanism for stinging behavior. These findings demonstrate how functional specialization of ion channel structure contributes to distinct organismal behavior.}, }
@article {pmid37905582, year = {2023}, author = {Radice, VZ and Martinez, A and Paytan, A and Potts, DC and Barshis, DJ}, title = {Complex dynamics of coral gene expression responses to low pH across species.}, journal = {Molecular ecology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mec.17186}, pmid = {37905582}, issn = {1365-294X}, support = {9915-16//The National Geographic Explorer grant/ ; //The National Park Foundation Science Fellowship/ ; }, abstract = {Coral capacity to tolerate low pH affects coral community composition and, ultimately, reef ecosystem function. Low pH submarine discharges ('Ojo'; Yucatán, México) represent a natural laboratory to study plasticity and acclimatization to low pH in relation to ocean acidification. A previous >2-year coral transplant experiment to ambient and low pH common garden sites revealed differential survivorship across species and sites, providing a framework to compare mechanistic responses to differential pH exposures. Here, we examined gene expression responses of transplants of three species of reef-building corals (Porites astreoides, Porites porites and Siderastrea siderea) and their algal endosymbiont communities (Symbiodiniaceae) originating from low pH (Ojo) and ambient pH native origins (Lagoon or Reef). Transplant pH environment had the greatest effect on gene expression of Porites astreoides hosts and symbionts and P. porites hosts. Host P. astreoides Ojo natives transplanted to ambient pH showed a similar gene expression profile to Lagoon natives remaining in ambient pH, providing evidence of plasticity in response to ambient pH conditions. Although origin had a larger effect on host S. siderea gene expression due to differences in symbiont genera within Reef and Lagoon/Ojo natives, subtle effects of low pH on all origins demonstrated acclimatization potential. All corals responded to low pH by differentially expressing genes related to pH regulation, ion transport, calcification, cell adhesion and stress/immune response. This study demonstrates that the magnitude of coral gene expression responses to pH varies considerably among populations, species and holobionts, which could differentially affect acclimatization to and impacts of ocean acidification.}, }
@article {pmid37891154, year = {2023}, author = {Matthews, JL and Khalil, A and Siboni, N and Bougoure, J and Guagliardo, P and Kuzhiumparambil, U and DeMaere, M and Le Reun, NM and Seymour, JR and Suggett, DJ and Raina, JB}, title = {Coral endosymbiont growth is enhanced by metabolic interactions with bacteria.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {6864}, pmid = {37891154}, issn = {2041-1723}, mesh = {Animals ; *Anthozoa/microbiology ; *Rhodobacteraceae ; Plant Growth Regulators ; Coral Reefs ; *Dinoflagellida ; Symbiosis ; }, abstract = {Bacteria are key contributors to microalgae resource acquisition, competitive performance, and functional diversity, but their potential metabolic interactions with coral microalgal endosymbionts (Symbiodiniaceae) have been largely overlooked. Here, we show that altering the bacterial composition of two widespread Symbiodiniaceae species, during their free-living stage, results in a significant shift in their cellular metabolism. Indeed, the abundance of monosaccharides and the key phytohormone indole-3-acetic acid (IAA) were correlated with the presence of specific bacteria, including members of the Labrenzia (Roseibium) and Marinobacter genera. Single-cell stable isotope tracking revealed that these two bacterial genera are involved in reciprocal exchanges of carbon and nitrogen with Symbiodiniaceae. We identified the provision of IAA by Labrenzia and Marinobacter, and this metabolite caused a significant growth enhancement of Symbiodiniaceae. By unravelling these interkingdom interactions, our work demonstrates how specific bacterial associates fundamentally govern Symbiodiniaceae fitness.}, }
@article {pmid37887820, year = {2023}, author = {Giorgini, M and Formisano, G and García-García, R and Bernat-Ponce, S and Beitia, F}, title = {The Susceptibility of Bemisia tabaci Mediterranean (MED) Species to Attack by a Parasitoid Wasp Changes between Two Whitefly Strains with Different Facultative Endosymbiotic Bacteria.}, journal = {Insects}, volume = {14}, number = {10}, pages = {}, pmid = {37887820}, issn = {2075-4450}, support = {Short Term Mobility Fellowship//National Research Council/ ; DBA.AD002.356 Lotta Biologica ed Integrata IPSP SS Portici//National Research Council/ ; KBBE 219262 (SWIPE)//ERA-NET - ARIMNet/ ; }, abstract = {In this study, two strains of the mitochondrial lineage Q1 of Bemisia tabaci MED species, characterized by a different complement of facultative bacterial endosymbionts, were tested for their susceptibility to be attacked by the parasitoid wasp Eretmocerus mundus, a widespread natural enemy of B. tabaci. Notably, the BtHC strain infected with Hamiltonella and Cardinium was more resistant to parasitization than the BtHR strain infected with Hamiltonella and Rickettsia. The resistant phenotype consisted of fewer nymphs successfully parasitized (containing the parasitoid mature larva or pupa) and in a lower percentage of adult wasps emerging from parasitized nymphs. Interestingly, the resistance traits were not evident when E. mundus parasitism was compared between BtHC and BtHR using parasitoids originating from a colony maintained on BtHC. However, when we moved the parasitoid colony on BtHR and tested E. mundus after it was reared on BtHR for four and seven generations, we saw then that BtHC was less susceptible to parasitization than BtHR. On the other hand, we did not detect any difference in the parasitization of the BtHR strain between the three generations of E. mundus tested. Our findings showed that host strain is a factor affecting the ability of E. mundus to parasitize B. tabaci and lay the basis for further studies aimed at disentangling the role of the facultative endosymbiont Cardinium and of the genetic background in the resistance of B. tabaci MED to parasitoid attack. Furthermore, they highlight that counteradaptations to the variation of B. tabaci defence mechanisms may be rapidly selected in E. mundus to maximize the parasitoid fitness.}, }
@article {pmid37882523, year = {2023}, author = {Głowska, E and Gerth, M}, title = {Draft genome sequence of a Wolbachia endosymbiont from Syringophilopsis turdi (Fritsch, 1958) (Acari, Syringophilidae).}, journal = {Microbiology resource announcements}, volume = {}, number = {}, pages = {e0060523}, doi = {10.1128/MRA.00605-23}, pmid = {37882523}, issn = {2576-098X}, abstract = {We present the draft genome of a Wolbachia endosymbiont from quill mites. This is the first representative of a recently discovered distinct Wolbachia lineage (supergroup P). We hope the genome will be a useful resource for comparative evolutionary and genomic studies across the globally distributed symbiont Wolbachia.}, }
@article {pmid37874788, year = {2023}, author = {Russell, SL and Castillo, JR and Sullivan, WT}, title = {Wolbachia endosymbionts manipulate the self-renewal and differentiation of germline stem cells to reinforce fertility of their fruit fly host.}, journal = {PLoS biology}, volume = {21}, number = {10}, pages = {e3002335}, pmid = {37874788}, issn = {1545-7885}, abstract = {The alphaproteobacterium Wolbachia pipientis infects arthropod and nematode species worldwide, making it a key target for host biological control. Wolbachia-driven host reproductive manipulations, such as cytoplasmic incompatibility (CI), are credited for catapulting these intracellular bacteria to high frequencies in host populations. Positive, perhaps mutualistic, reproductive manipulations also increase infection frequencies, but are not well understood. Here, we identify molecular and cellular mechanisms by which Wolbachia influences the molecularly distinct processes of germline stem cell (GSC) self-renewal and differentiation. We demonstrate that wMel infection rescues the fertility of flies lacking the translational regulator mei-P26 and is sufficient to sustain infertile homozygous mei-P26-knockdown stocks indefinitely. Cytology revealed that wMel mitigates the impact of mei-P26 loss through restoring proper pMad, Bam, Sxl, and Orb expression. In Oregon R files with wild-type fertility, wMel infection elevates lifetime egg hatch rates. Exploring these phenotypes through dual-RNAseq quantification of eukaryotic and bacterial transcripts revealed that wMel infection rescues and offsets many gene expression changes induced by mei-P26 loss at the mRNA level. Overall, we show that wMel infection beneficially reinforces host fertility at mRNA, protein, and phenotypic levels, and these mechanisms may promote the emergence of mutualism and the breakdown of host reproductive manipulations.}, }
@article {pmid37873081, year = {2023}, author = {Perlmutter, JI and Atadurdyyeva, A and Schedl, ME and Unckless, RL}, title = {Wolbachia enhances the survival of Drosophila infected with fungal pathogens.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.09.30.560320}, pmid = {37873081}, abstract = {UNLABELLED: Wolbachia bacteria of arthropods are at the forefront of basic and translational research on multipartite host-symbiont-pathogen interactions. These microbes are vertically inherited from mother to offspring via the cytoplasm. They are the most widespread endosymbionts on the planet due to their infamous ability to manipulate the reproduction of their hosts to spread themselves in a population, and to provide a variety of fitness benefits to their hosts. Importantly, some strains of Wolbachia can inhibit viral pathogenesis within and between arthropod hosts. Mosquitoes carrying the w Mel Wolbachia strain of Drosophila melanogaster have a greatly reduced capacity to spread viruses like dengue and Zika to humans. Therefore, Wolbachia are the basis of several global vector control initiatives. While significant research efforts have focused on viruses, relatively little attention has been given to Wolbachia -fungal interactions despite the ubiquity of fungal entomopathogens in nature. Here, we demonstrate that Wolbachia increase the longevity of their Drosophila melanogaster hosts when challenged with a spectrum of yeast and filamentous fungal pathogens. We find that this pattern can vary based on host genotype, sex, and fungal species. Further, Wolbachia correlates with higher fertility and reduced pathogen titers during initial fungal infection, indicating a significant fitness benefit. This study demonstrates Wolbachia 's role in diverse fungal pathogen interactions and determines that the phenotype is broad, but with several variables that influence both the presence and strength of the phenotype. These results enhance our knowledge of the strategies Wolbachia uses that likely contribute to such a high global symbiont prevalence.<br><br>IMPORTANCE: Wolbachia bacteria of arthropods are at the forefront of global initiatives to fight arthropod-borne viruses. Despite great success in using the symbiont to fight viruses, little research has focused on Wolbachia -fungal interactions. Here, we find that Wolbachia of Drosophila melanogaster , the same strain widely used in antiviral initiatives, can also increase the longevity of flies systemically infected with a panel of yeast and filamentous fungal pathogens. The symbiont also partially increases host fertility and reduces fungal titers during early infection, indicating a significant fitness benefit. This represents a major step forward in Wolbachia research since its pathogen blocking abilities can now be extended to a broad diversity of another major branch of microbial life. This discovery may inform basic research on pathogen blocking and has potential translational applications in areas including biocontrol in agriculture.}, }
@article {pmid37871129, year = {2023}, author = {Wenzel, M and Aquadro, CF}, title = {Wolbachia infection at least partially rescues the fertility and ovary defects of several new Drosophila melanogaster bag of marbles protein-coding mutants.}, journal = {PLoS genetics}, volume = {19}, number = {10}, pages = {e1011009}, doi = {10.1371/journal.pgen.1011009}, pmid = {37871129}, issn = {1553-7404}, abstract = {The D. melanogaster protein coding gene bag of marbles (bam) plays a key role in early male and female reproduction by forming complexes with partner proteins to promote differentiation in gametogenesis. Like another germline gene, Sex lethal, bam genetically interacts with the endosymbiont Wolbachia, as Wolbachia rescues the reduced fertility of a bam hypomorphic mutant. Here, we explored the specificity of the bam-Wolbachia interaction by generating 22 new bam mutants, with ten mutants displaying fertility defects. Nine of these mutants trend towards rescue by the wMel Wolbachia variant, with eight statistically significant at the fertility and/or cytological level. In some cases, fertility was increased a striking 20-fold. There is no specificity between the rescue and the known binding regions of bam, suggesting wMel does not interact with one singular bam partner to rescue the reproductive phenotype. We further tested if wMel interacts with bam in a non-specific way, by increasing bam transcript levels or acting upstream in germline stem cells. A fertility assessment of a bam RNAi knockdown mutant reveals that wMel rescue is specific to functionally mutant bam alleles and we find no obvious evidence of wMel interaction with germline stem cells in bam mutants.}, }
@article {pmid37871041, year = {2023}, author = {Bustamante, JA and Ceron, JS and Gao, IT and Ramirez, HA and Aviles, MV and Bet Adam, D and Brice, JR and Cuellar, R and Dockery, E and Jabagat, MK and Karp, DG and Lau, JK and Li, S and Lopez-Magaña, R and Moore, RR and Morin, BKR and Nzongo, J and Rezaeihaghighi, Y and Sapienza-Martinez, J and Tran, TTK and Huang, Z and Duthoy, AJ and Barnett, MJ and Long, SR and Chen, JC}, title = {A protease and a lipoprotein jointly modulate the conserved ExoR-ExoS-ChvI signaling pathway critical in Sinorhizobium meliloti for symbiosis with legume hosts.}, journal = {PLoS genetics}, volume = {19}, number = {10}, pages = {e1010776}, doi = {10.1371/journal.pgen.1010776}, pmid = {37871041}, issn = {1553-7404}, abstract = {Sinorhizobium meliloti is a model alpha-proteobacterium for investigating microbe-host interactions, in particular nitrogen-fixing rhizobium-legume symbioses. Successful infection requires complex coordination between compatible host and endosymbiont, including bacterial production of succinoglycan, also known as exopolysaccharide-I (EPS-I). In S. meliloti EPS-I production is controlled by the conserved ExoS-ChvI two-component system. Periplasmic ExoR associates with the ExoS histidine kinase and negatively regulates ChvI-dependent expression of exo genes, necessary for EPS-I synthesis. We show that two extracytoplasmic proteins, LppA (a lipoprotein) and JspA (a lipoprotein and a metalloprotease), jointly influence EPS-I synthesis by modulating the ExoR-ExoS-ChvI pathway and expression of genes in the ChvI regulon. Deletions of jspA and lppA led to lower EPS-I production and competitive disadvantage during host colonization, for both S. meliloti with Medicago sativa and S. medicae with M. truncatula. Overexpression of jspA reduced steady-state levels of ExoR, suggesting that the JspA protease participates in ExoR degradation. This reduction in ExoR levels is dependent on LppA and can be replicated with ExoR, JspA, and LppA expressed exogenously in Caulobacter crescentus and Escherichia coli. Akin to signaling pathways that sense extracytoplasmic stress in other bacteria, JspA and LppA may monitor periplasmic conditions during interaction with the plant host to adjust accordingly expression of genes that contribute to efficient symbiosis. The molecular mechanisms underlying host colonization in our model system may have parallels in related alpha-proteobacteria.}, }
@article {pmid37864609, year = {2023}, author = {Vaurs, M and Dolu, EB and Decottignies, A}, title = {Mitochondria and telomeres: hand in glove.}, journal = {Biogerontology}, volume = {}, number = {}, pages = {}, pmid = {37864609}, issn = {1573-6768}, abstract = {Born as an endosymbiont, the bacteria engulfed by the proto-eukaryotic cell more than 1.45 billion years ago progressively evolved as an important organelle with multiple interactions with the host cell. In particular, strong connections between mitochondria and the chromosome ends, the telomeres, led to propose a new theory of ageing in which dysfunctional telomeres and mitochondria are the main actors of a vicious circle reducing cell fitness and promoting cellular ageing. We review the evidences that oxidative stress and dysfunctional mitochondria damage telomeres and further discuss the interrelationship between telomere biology and mitochondria through the lens of telomerase which shuttles between the nucleus and mitochondria. Finally, we elaborate on the possible role of the mitochondrial genome on the inheritance of human telomere length through the expression of mitochondrial gene variants.}, }
@article {pmid37860089, year = {2023}, author = {Rushidi, MNA and Azhari, MLH and Yaakop, S and Hazmi, IR}, title = {Detection and Characterisation of Endosymbiont Wolbachia (Rickettsiales: Anaplasmataceae) in Elaeidobius kamerunicus (Coleoptera: Curculionoidea), Pollinating Agent of Oil Palm, and Its Relationships between Populations.}, journal = {Tropical life sciences research}, volume = {34}, number = {3}, pages = {95-111}, pmid = {37860089}, issn = {1985-3718}, abstract = {Elaeidobius kamerunicus is the most efficient pollinator of oil palm. Wolbachia is an endosymbiotic bacteria associated with E. kamerunicus that has a potential to affect the fecundity and fitness of the E. kamerunicus. Despite their importance, no studies have been conducted to investigate its prevalence in E. kamerunicus. The objectives of this study were to detect and characterise Wolbachia in E. kamerunicus and determine the phylogenetic relationship of Wolbachia strains that infect E. kamerunicus by using three genetic markers namely Filamenting temperature-sensitive mutant Z (ftsZ), Chaperonin folding protein (groEL), and Citrate Synthase Coding Gene (gltA). DNA was extracted from 210 individuals of E. kamerunicus and the Wolbachia infections were detected using the wsp marker. The infected samples (n = 25, 11.9%) were then sequenced using ftsZ, gltA and groEL markers for strain characterization. In this study, a combination of four markers was used to construct the phylogeny of Wolbachia. Similar topologies were shown in all trees; Neighbour-Joining (NJ), Maximum Parsimony (MP), and Bayesian Inference (BI), which showed the mixing of individuals that harbor Wolbachia between populations. Interestingly, Wolbachia on E. kamerunicus was claded together with the species Drosophila simulans under supergroup B. This is the first report of Wolbachia infecting E. kamerunicus which is very valuable and significant as one of the parameters to evaluate the quality of the E. kamerunicus population for sustaining its function as a great pollinator for oil palm.}, }
@article {pmid37860043, year = {2023}, author = {Mannaa, M and Seo, YS}, title = {Improved and simplified method for aseptic isolation of nematodes and nematode-endosymbiotic bacteria from pine seedlings.}, journal = {MethodsX}, volume = {11}, number = {}, pages = {102421}, pmid = {37860043}, issn = {2215-0161}, abstract = {Pine wilt disease (PWD), caused by the pinewood nematode (PWN), Bursaphelenchus xylophilus, significantly impacts pine species and poses a broader ecological concern. An understanding of these nematode-associated microbes is essential for formulating sustainable PWD management strategies. We introduce a streamlined method for the aseptic extraction of B. xylophilus from pine seedlings, evolving beyond traditional Baermann funnel approaches. The method ensures optimal nematode extraction under sterile parameters, with seedling cutting discs processed using a unique sterile syringe assembly setup. The efficiency and simplicity of this method promise to significantly reduce the time and resources required. It also incorporates endosymbiotic bacterial isolation from isolated nematodes. The robustness of this method is affirmed by the successful isolation and identification of nematodes and bacterial strains as endosymbionts. Collectively, this protocol paves the way for more effective studies of nematodes and associated microbes, promoting the understanding of PWD and offering practical implications for better PWD management.•A simplified, aseptic method for extracting B. xylophilus from pine seedlings, offering a modern alternative to traditional Baermann funnel method.•Utilization of a specialized sterile syringe assembly setup, ensuring controlled and optimal nematode isolation.•Method validation achieved through the successful isolation and identification of bacterial strains as nematode endosymbionts.}, }
@article {pmid37858069, year = {2023}, author = {Bu, XL and Zhao, WS and Li, ZY and Ma, HW and Chen, YS and Li, WX and Zou, H and Li, M and Wang, GT}, title = {The energy metabolism of Balantidium polyvacuolum inhabiting the hindgut of Xenocypris davidi.}, journal = {BMC genomics}, volume = {24}, number = {1}, pages = {624}, pmid = {37858069}, issn = {1471-2164}, support = {No. 32170437//National Natural Science Foundation of China/ ; No. 2019QZKK0304//the Second Tibetan Plateau Scientific Expedition and Research Program/ ; No. CARS-45//the earmarked fund for CARS/ ; }, abstract = {Anaerobic parasitic ciliates are a specialized group of ciliates that are adapted to anoxic and oxygen-depleted habitats. Among them, Balantidium polyvacuolum, which inhabits the hindgut of Xenocyprinae fishes, has received very limited scientific attention, so the molecular mechanism of its adaptation to the digestive tract microenvironment is still unclear. In this study, transmission electron microscopy (TEM) and single-cell transcriptome analysis were used to uncover the metabolism of B. polyvacuolum. Starch granules, endosymbiotic bacteria, and multiple specialized mitochondrion-related organelles (MROs) of various shapes were observed. The MROs may have completely lost the electron transport chain (ETC) complexes I, III, IV, and V and only retained succinate dehydrogenase subunit A (SDHA) of complex II. The tricarboxylic acid (TCA) cycle was also incomplete. It can be inferred that the hypoxic intestinal environment has led to the specialization of the mitochondria in B. polyvacuolum. Moreover, carbohydrate-active enzymes (CAZymes), including carbohydrate esterases, enzymes with a carbohydrate-binding module, glycoside hydrolases, and glycosyltransferases, were identified, which may constitute evidence that B. polyvacuolum is able to digest carbohydrates and starch. These findings can improve our knowledge of the energy metabolism and adaptive mechanisms of B. polyvacuolum.}, }
@article {pmid37850668, year = {2023}, author = {Hepler, JR and Cooper, WR and Cullum, JP and Dardick, C and Dardick, L and Nixon, LJ and Pouchnik, DJ and Raupp, MJ and Shrewsbury, P and Leskey, TC}, title = {Do adult Magicicada (Hemiptera: Cicadidae) feed? Historical perspectives and evidence from molecular gut content analysis.}, journal = {Journal of insect science (Online)}, volume = {23}, number = {5}, pages = {}, doi = {10.1093/jisesa/iead082}, pmid = {37850668}, issn = {1536-2442}, support = {8080-21000-032-000D//USDA-ARS-CRIS/ ; }, abstract = {The periodical cicadas in the genus Magicicada are remarkable for their unusual life histories and dramatic synchronized emergences every 13 or 17 years. While aspects of their evolution, mating behaviors, and general biology have been well-characterized, there is surprising uncertainty surrounding the feeding habits of the short-lived adult stage. Despite a tentative scientific consensus to the contrary, the perception that adult Magicicada do not feed has persisted among the general public, and recent studies are lacking. We directly investigated the feeding behavior of Magicicada spp. through high-throughput sequencing (HTS)-based dietary analysis of nymphs, freshly molted (teneral) adults, and fully sclerotized adults collected from orchard and wooded habitats during the 2021 emergence of Brood X. Identifiable plant DNA (trnF, ITS amplicons) was successfully recovered from nymphs and adults. No plant DNA was recovered from teneral adults, suggesting that all DNA recovered from sclerotized adults was ingested during the post-teneral adult stage. Both nymphs and adults were found to have ingested a range of woody and herbaceous plants across 17 genera and 14 families. Significantly more plant genera per individual were recovered from adults than from nymphs, likely reflecting the greater mobility of the adult stage. We hypothesize that the demonstrated ingestion of plant sap by Magicicada adults is driven by a need to replace lost water and support specialized bacteriome-dwelling endosymbionts that cicadas depend upon for growth and development, which constitutes true feeding behavior.}, }
@article {pmid37844224, year = {2023}, author = {Duncan, RP and Anderson, CMH and Thwaites, DT and Luetje, CW and Wilson, ACC}, title = {Co-option of a conserved host glutamine transporter facilitates aphid/Buchnera metabolic integration.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {43}, pages = {e2308448120}, doi = {10.1073/pnas.2308448120}, pmid = {37844224}, issn = {1091-6490}, support = {DEB-1406631//National Science Foundation (NSF)/ ; IOS-1354154//National Science Foundation (NSF)/ ; N/A//Newcastle University NUAcT fellowship/ ; RGS\R1\221113//Royal Society (The Royal Society)/ ; 47690-FR//The Physiological Society Momentum Fellowship/ ; N/A//Rank Prize new lecturer grant/ ; }, abstract = {Organisms across the tree of life colonize novel environments by partnering with bacterial symbionts. These symbioses are characterized by intimate integration of host/endosymbiont biology at multiple levels, including metabolically. Metabolic integration is particularly important for sap-feeding insects and their symbionts, which supplement nutritionally unbalanced host diets. Many studies reveal parallel evolution of host/endosymbiont metabolic complementarity in amino acid biosynthesis, raising questions about how amino acid metabolism is regulated, how regulatory mechanisms evolve, and the extent to which similar mechanisms evolve in different systems. In the aphid/Buchnera symbiosis, the transporter ApGLNT1 (Acyrthosiphon pisum glutamine transporter 1) supplies glutamine, an amino donor in transamination reactions, to bacteriocytes (where Buchnera reside) and is competitively inhibited by Buchnera-supplied arginine-consistent with a role regulating amino acid metabolism given host demand for Buchnera-produced amino acids. We examined how ApGLNT1 evolved a regulatory role by functionally characterizing orthologs in insects with and without endosymbionts. ApGLNT1 orthologs are functionally similar, and orthology searches coupled with homology modeling revealed that GLNT1 is ancient and structurally conserved across insects. Our results indicate that the ApGLNT1 symbiotic regulatory role is derived from its ancestral role and, in aphids, is likely facilitated by loss of arginine biosynthesis through the urea cycle. Given consistent loss of host arginine biosynthesis and retention of endosymbiont arginine supply, we hypothesize that GLNT1 is a general mechanism regulating amino acid metabolism in sap-feeding insects. This work fills a gap, highlighting the broad importance of co-option of ancestral proteins to novel contexts in the evolution of host/symbiont systems.}, }
@article {pmid37838705, year = {2023}, author = {Sounart, H and Voronin, D and Masarapu, Y and Chung, M and Saarenpää, S and Ghedin, E and Giacomello, S}, title = {Miniature spatial transcriptomics for studying parasite-endosymbiont relationships at the micro scale.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {6500}, pmid = {37838705}, issn = {2041-1723}, abstract = {Several important human infectious diseases are caused by microscale-sized parasitic nematodes like filarial worms. Filarial worms have their own spatial tissue organization; to uncover this tissue structure, we need methods that can spatially resolve these miniature specimens. Most filarial worms evolved a mutualistic association with endosymbiotic bacteria Wolbachia. However, the mechanisms underlying the dependency of filarial worms on the fitness of these bacteria remain unknown. As Wolbachia is essential for the development, reproduction, and survival of filarial worms, we spatially explored how Wolbachia interacts with the worm's reproductive system by performing a spatial characterization using Spatial Transcriptomics (ST) across a posterior region containing reproductive tissue and developing embryos of adult female Brugia malayi worms. We provide a proof-of-concept for miniature-ST to explore spatial gene expression patterns in small sample types, demonstrating the method's ability to uncover nuanced tissue region expression patterns, observe the spatial localization of key B. malayi - Wolbachia pathway genes, and co-localize the B. malayi spatial transcriptome in Wolbachia tissue regions, also under antibiotic treatment. We envision our approach will open up new avenues for the study of infectious diseases caused by micro-scale parasitic worms.}, }
@article {pmid37827122, year = {2023}, author = {Butterworth, S and Kordova, K and Chandrasekaran, S and Thomas, KK and Torelli, F and Lockyer, EJ and Edwards, A and Goldstone, R and Koshy, AA and Treeck, M}, title = {High-throughput identification of Toxoplasma gondii effector proteins that target host cell transcription.}, journal = {Cell host &amp; microbe}, volume = {31}, number = {10}, pages = {1748-1762.e8}, doi = {10.1016/j.chom.2023.09.003}, pmid = {37827122}, issn = {1934-6069}, abstract = {Intracellular pathogens and other endosymbionts reprogram host cell transcription to suppress immune responses and recalibrate biosynthetic pathways. This reprogramming is critical in determining the outcome of infection or colonization. We combine pooled CRISPR knockout screening with dual host-microbe single-cell RNA sequencing, a method we term dual perturb-seq, to identify the molecular mediators of these transcriptional interactions. Applying dual perturb-seq to the intracellular pathogen Toxoplasma gondii, we are able to identify previously uncharacterized effector proteins and directly infer their function from the transcriptomic data. We show that TgGRA59 contributes to the export of other effector proteins from the parasite into the host cell and identify an effector, TgSOS1, that is necessary for sustained host STAT6 signaling and thereby contributes to parasite immune evasion and persistence. Together, this work demonstrates a tool that can be broadly adapted to interrogate host-microbe transcriptional interactions and reveal mechanisms of infection and immune evasion.}, }
@article {pmid37820843, year = {2023}, author = {Thanchomnang, T and Rodpai, R and Thinnabut, K and Boonroumkaew, P and Sadaow, L and Tangkawanit, U and Sanpool, O and Janwan, P and Intapan, PM and Maleewong, W}, title = {Characterization of the bacterial microbiota of cattle ticks in northeastern Thailand through 16S rRNA amplicon sequencing.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {}, number = {}, pages = {105511}, doi = {10.1016/j.meegid.2023.105511}, pmid = {37820843}, issn = {1567-7257}, abstract = {Ticks are vectors of a variety of pathogens that can infect humans and animals. Ticks also harbor non-pathogenic microbiota. This study characterized the microbiota of the ticks infesting beef cattle in Thailand. Two species of ticks; Rhipicephalus microplus (n = 15) and Haemaphysalis bispinosa (n = 5), were collected in seven provinces in northeastern Thailand. Microbial community profile of ticks was examined based on sequences of the V3-V4 region of 16S rRNA gene. Proteobacteria (Pseudomonadota) was the most abundant phylum, followed by Firmicutes (Bacillota), and Actinobacteriota. Coxiella-like endosymbiont was the most abundant bacterial taxon overall (49% of sequence reads), followed by Anaplasma (8.5%), Corynebacterium (5.5%), Ehrlichia (3.9%), and Castellaniella (3.4%). Co-infections of the pathogenic bacteria Ehrlichia and Anaplasma were detected in 19/20 (95%) female ticks. The tick with the lowest number of bacteria had the lowest abundance of the Coxiella-like endosymbiont, and the pathogenic bacteria Anaplasma and Ehrlichia were absent. This study provides baseline information of the microbiota of cattle ticks in northeastern Thailand, suggesting that ticks carry a few dominant bacterial taxa that are primarily non-pathogenic but can co-occur with pathogenic microorganisms. The information obtained is useful for monitoring disease outbreaks in the future and informing prevention and control strategies against cattle tick-borne diseases.}, }
@article {pmid37819592, year = {2023}, author = {Haghshenas-Gorgabi, N and Poorjavd, N and Khajehali, J and Wybouw, N}, title = {Cardinium symbionts are pervasive in Iranian populations of the spider mite Panonychus ulmi despite inducing an infection cost and no demonstrable reproductive phenotypes when Wolbachia is a symbiotic partner.}, journal = {Experimental &amp; applied acarology}, volume = {}, number = {}, pages = {}, pmid = {37819592}, issn = {1572-9702}, abstract = {Maternally transmitted symbionts such as Cardinium and Wolbachia are widespread in arthropods. Both Cardinium and Wolbachia can cause cytoplasmic incompatibility, a reproductive phenotype that interferes with the development of uninfected eggs that are fertilized by infected sperm. In haplodiploid hosts, these symbionts can also distort sex allocation to facilitate their spread through host populations. Without other fitness effects, symbionts that induce strong reproductive phenotypes tend to spread to high and stable infection frequencies, whereas variants that induce weak reproductive phenotypes are typically associated with intermediate and variable frequencies. To study the spread of Cardinium in a haplodiploid host, we sampled Iranian populations of the economically important spider mite Panonychus ulmi in apple orchards. Within several field populations, we also studied the Wolbachia infection frequencies. All P. ulmi field populations carried a Cardinium infection and exhibited high infection frequencies. In contrast, Wolbachia frequency ranged between ca. 10% and ca. 70% and was only found in co-infected mites. To test whether Cardinium induce reproductive phenotypes in P. ulmi, a Cardinium-cured derived line was generated by antibiotic treatment from a co-infected field population. Genetic crosses indicated that Cardinium do not induce demonstrable levels of cytoplasmic incompatibility and sex allocation distortion in co-infected P. ulmi. However, Cardinium infection was associated with a longer developmental time and reduced total fecundity for co-infected females. We hypothesize that Cardinium spread through P. ulmi populations via uncharacterized fitness effects and that co-infection with Wolbachia might impact these drive mechanisms.}, }
@article {pmid37816433, year = {2023}, author = {Margarita, V and Carboni, G and Diaz, N and Rappelli, P and Fiori, PL}, title = {Patterns of antibiotic resistance of Mycoplasma hominis endosymbiont of Trichomonas vaginalis and the influence of bacterial intracellular location on drugs susceptibility.}, journal = {Journal of global antimicrobial resistance}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jgar.2023.09.021}, pmid = {37816433}, issn = {2213-7173}, abstract = {OBJECTIVES: Mycoplasma hominis, an opportunistic pathogen of the human lower urogenital tract, can survive and replicate within the protozoan Trichomonas vaginalis, establishing an endosymbiotic relationship. The intracellular location may provide a means for the bacteria to evade the immune system and protection from antimicrobial activities. Our aim was to investigate the influence of the endosymbiotic association of M. hominis with trichomonad cells on bacterial antibiotic susceptibility.<br><br>METHODS: We evaluated antibiotic resistance patterns in a group of M. hominis isolated from T. vaginalis clinical specimens as well as in M. hominis isolated from patients without trichomoniasis. Using an experimental model system, we compared the minimal inhibitory concentration (MIC) and lethal concentration (MLC) of tetracycline on M. hominis endosymbionts of T. vaginalis and extracellular bacteria.<br><br>RESULTS: The incidence rate of M. hominis strains resistant to C14 and C15 macrolide antibiotics was higher in intracellular strains associated with T. vaginalis compared to extracellular bacteria isolated from women not affected by trichomoniasis. However, sensitivity to tetracycline and quinolones was similar in both groups. In vitro experiments demonstrated that M. hominis strains, when isolated as endosymbionts from T. vaginalis, exhibited reduced sensitivity to tetracycline when cultured extracellularly for at least 8 weeks.<br><br>CONCLUSION: The intracellular localization of bacteria within trichomonad cells may impact antibiotic susceptibility.}, }
@article {pmid37813003, year = {2023}, author = {Oundo, JW and Kalayou, S and Bosch, QT and Villinger, J and Koenraadt, CJM and Masiga, D}, title = {Ticks (Acari: Ixodidae) infesting cattle in coastal Kenya harbor a diverse array of tick-borne pathogens.}, journal = {Ticks and tick-borne diseases}, volume = {15}, number = {1}, pages = {102266}, doi = {10.1016/j.ttbdis.2023.102266}, pmid = {37813003}, issn = {1877-9603}, abstract = {Ticks and the microbes they transmit have emerged in sub-Saharan Africa as a major threat to veterinary and public health. Although progress has been made in detecting and identifying tick-borne pathogens (TBPs) across vast agroecologies of Kenya, comprehensive information on tick species infesting cattle and their associated pathogens in coastal Kenya needs to be updated and expanded. Ticks infesting extensively grazed zebu cattle in 14 villages were sampled and identified based on morphology and molecular methods and tested for the presence of bacterial and protozoan TBPs using PCR with high-resolution melting analysis and gene sequencing. In total, 3,213 adult ticks were collected and identified as Rhipicephalus appendiculatus (15.8%), R. evertsi (12.8%), R. microplus (11.3%), R. pulchellus (0.1%), Amblyomma gemma (24.1%), A. variegatum (35.1%), Hyalomma rufipes (0.6%), and H. albiparmatum (0.2%). Ticks were infected with Rickettsia africae, Ehrlichia ruminantium, E. minasensis, Theileria velifera and T. parva. Coxiella sp. endosymbionts were detected in the Rhipicephalus and Amblyomma ticks. Co-infections with two and three different pathogens were identified in 6.9% (n = 95/1382) and 0.1% (n = 2/1382) of single tick samples, respectively, with the most common co-infection being R. africae and E. ruminantium (7.2%, CI: 4.6 - 10.6). All samples were negative for Coxiella burnetii, Anaplasma spp. and Babesia spp. Our study provides an overview of tick and tick-borne microbial diversities in coastal Kenya.}, }
@article {pmid37810228, year = {2023}, author = {Kwak, Y and Hansen, AK}, title = {Unveiling metabolic integration in psyllids and their nutritional endosymbionts through comparative transcriptomics analysis.}, journal = {iScience}, volume = {26}, number = {10}, pages = {107930}, pmid = {37810228}, issn = {2589-0042}, abstract = {Psyllids, a group of insects that feed on plant sap, have a symbiotic relationship with an endosymbiont called Carsonella. Carsonella synthesizes essential amino acids and vitamins for its psyllid host, but lacks certain genes required for this process, suggesting a compensatory role of psyllid host genes. To investigate this, gene expression was compared between two psyllid species, Bactericera cockerelli and Diaphorina citri, in specialized cells where Carsonella resides (bacteriomes). Collaborative psyllid genes, including horizontally transferred genes, showed patterns of conserved gene expression; however, species-specific patterns were also observed, suggesting differences in the nutritional metabolism between psyllid species. Also, the recycling of nitrogen in bacteriomes may primarily rely on glutamate dehydrogenase (GDH). Additionally, lineage-specific gene clusters were differentially expressed in B. cockerelli and D. citri bacteriomes and are highlighted here. These findings shed light on potential host adaptations for the regulation of this symbiosis due to host, microbiome, and environmental differences.}, }
@article {pmid37808301, year = {2023}, author = {Cui, X and Liu, Y and Zhang, J and Hu, P and Zheng, Z and Deng, X and Xu, M}, title = {Variation of endosymbiont and citrus tristeza virus (CTV) titers in the Huanglongbing insect vector, Diaphorina citri, on CTV-infected plants.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1236731}, pmid = {37808301}, issn = {1664-302X}, abstract = {"Candidatus Liberibacter asiaticus" (CLas) is a notorious agent that causes Citrus Huanglongbing (HLB), which is transmitted by Diaphorina citri (D. citri). We recently found that the acquisition and transmission of CLas by D. citri was facilitated by Citrus tristeza virus (CTV), a widely distributed virus in the field. In this study, we further studied whether different CTV strains manipulate the host preference of D. citri, and whether endosymbionts variation is related to CTV strains in D. citri. The results showed that the non-viruliferous D. citri preferred to select the shoots infected with CTV, without strain differences was observed in the selection. However, the viruliferous D. citri prefered to select the mixed strain that is similar to the field's. Furthermore, D. citri effectively acquired the CTV within 2-12 h depending on the strains of the virus. The persistence period of CTV in D. citri was longer than 24 days, without reduction of the CTV titers being observed. These results provide a foundation for understanding the transmission mode of D. citri on CTV. During the process of CTV acquisition and persistence, the titers of main endosymbionts in D. citri showed similar variation trend, but their relative titers were different at different time points. The titers of the "Candidatus Profftella armatura" and CTV tended to be positively correlated, and the titers of Wolbachia and "Candidatus Carsonella ruddii" were mostly negatively related with titers of CT31. These results showed the relationship among D. citri, endosymbionts, and CTV and provided useful information for further research on the interactions between D. citri and CLas, which may benefit the development of approaches for the prevention of CLas transmission and control of citrus HLB.}, }
@article {pmid37808105, year = {2023}, author = {Pikula, J and Piacek, V and Bandouchova, H and Bartlova, M and Bednarikova, S and Burianova, R and Danek, O and Jedlicka, P and Masova, S and Nemcova, M and Seidlova, V and Zukalova, K and Zukal, J}, title = {Case report: Filarial infection of a parti-coloured bat: Litomosa sp. adult worms in abdominal cavity and microfilariae in bat semen.}, journal = {Frontiers in veterinary science}, volume = {10}, number = {}, pages = {1284025}, pmid = {37808105}, issn = {2297-1769}, abstract = {BACKGROUND: Filarial infections have been understudied in bats. Likewise, little is known about pathogens associated with the reproductive system in chiropterans. While semen quality is critical for reproductive success, semen-borne pathogens may contribute to reproductive failure.<br><br>METHODS: For the first time we performed electroejaculation and used computer-assisted semen analysis to provide baseline data on semen quality in a parti-coloured bat (Vespertilio murinus).<br><br>RESULTS: The semen quality values measured in the V. murinus male appeared high (semen concentration&#x2009;=&#x2009;305.4&#x2009;&#xd7;&#x2009;10[6]/mL; progressive and motile sperm&#x2009;=&#x2009;46.58 and 60.27%, respectively). As an incidental finding, however, microfilariae were observed in the bat semen examined. At necropsy, eight adult filarial worms, later genetically identified as Litomosa sp., were found in the peritoneal cavity, close to the stomach, of the same particoloured bat male dying as a result of dysmicrobia and haemorrhagic gastroenteritis in a wildlife rescue centre. Histopathology revealed microfilariae in the testicular connective tissue and the epidydimal connective and fat tissues. A PCR assay targeting cytochrome c oxidase subunit 1 confirmed that adult worms from the peritoneal cavity and testicular microfilariae were of the same filarial species. Mildly engorged argasid mite larvae attached to the bat skin proved negative for filarial DNA and the adult filarial worms proved negative for endosymbiont Wolbachia.<br><br>CONCLUSION: While the standard filarial life cycle pattern involves a vertebrate definitive host and an invertebrate vector, represented by a blood-sucking ectoparasite, our finding suggests that microfilariae of this nematode species may also be semen-borne, with transmission intensity promoted by the polygynous mating system of vespertilionid bats in which an infected male mates with many females during the autumn swarming. Presence of microfilariae may be expected to decrease semen quality and transmission via this route may challenge the success of reproductive events in females after mating. Further investigation will be necessary to better understand the bat-parasite interaction and the life cycle of this filarial worm.}, }
@article {pmid37794084, year = {2023}, author = {Hettiarachchi, A and Cnockaert, M and Joossens, M and Gekière, A and Meeus, I and Vereecken, NJ and Michez, D and Smagghe, G and Vandamme, P}, title = {The wild solitary bees Andrena vaga, Anthophora plumipes, Colletes cunicularius, and Osmia cornuta microbiota are host specific and dominated by endosymbionts and environmental microorganisms.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {37794084}, issn = {1432-184X}, abstract = {We characterized the microbial communities of the crop, midgut, hindgut, and ovaries of the wild solitary bees Andrena vaga, Anthophora plumipes, Colletes cunicularius, and Osmia cornuta through 16S rRNA gene and ITS2 amplicon sequencing and a large-scale isolation campaign. The bacterial communities of these bees were dominated by endosymbionts of the genera Wolbachia and Spiroplasma. Bacterial and yeast genera representing the remaining predominant taxa were linked to an environmental origin. While only a single sampling site was examined for Andrena vaga, Anthophora plumipes, and Colletes cunicularius, and two sampling sites for Osmia cornuta, the microbiota appeared to be host specific: bacterial, but not fungal, communities generally differed between the analyzed bee species, gut compartments and ovaries. This may suggest a selective process determined by floral and host traits. Many of the gut symbionts identified in the present study are characterized by metabolic versatility. Whether they exert similar functionalities within the bee gut and thus functional redundancy remains to be elucidated.}, }
@article {pmid37778576, year = {2023}, author = {Datki, Z and Darula, Z and Vedelek, V and Hunyadi-Gulyas, E and Dingmann, BJ and Vedelek, B and Kalman, J and Urban, P and Gyenesei, A and Galik-Olah, Z and Galik, B and Sinka, R}, title = {Biofilm formation initiating rotifer-specific biopolymer and its predicted components.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {127157}, doi = {10.1016/j.ijbiomac.2023.127157}, pmid = {37778576}, issn = {1879-0003}, abstract = {The rotifer-specific biopolymer, namely Rotimer, is a recently discovered group of the biomolecule family. Rotimer has an active role in the biofilm formation initiated by rotifers (e.g., Euchlanis dilatata or Adineta vaga) or in the female-male sexual interaction of monogononts. To understand the Ca[2+]- and polarity-dependent formation of this multifunctional viscoelastic material, it is essential to explore its molecular composition. The investigation of the rotifer-enhanced biofilm and Rotimer-inductor conglomerate (RIC) formation yielded several protein candidates to predict the Rotimer-specific main components. The exudate of E. dilatata males was primarily applied from different biopolimer-containing samples (biofilm or RIC). The advantage of males over females lies in their degenerated digestive system and simple anatomy. Thus, their exudate is less contaminated with food and endosymbiont elements. The sequenced and annotated genome and transcriptome of this species opened the way for identifying Rotimer proteins by mass spectrometry. The predicted rotifer-biopolymer forming components are SCO-spondins and 14-3-3 protein. The characteristics of Rotimer are similar to Reissner's fiber, which is found in the central nervous system of vertebrates and is mainly formed from SCO-spondins. This molecular information serves as a starting point for its interdisciplinary investigation and application in biotechnology, biomedicine, or neurodegeneration-related drug development.}, }
@article {pmid37768955, year = {2023}, author = {Chebbah, D and Hamarsheh, O and Sereno, D and Elissa, N and Brun, S and Jan, J and Izri, A and Akhoundi, M}, title = {Molecular characterization and genetic diversity of Wolbachia endosymbionts in bed bugs (Hemiptera; Cimicidae) collected in Paris.}, journal = {PloS one}, volume = {18}, number = {9}, pages = {e0292229}, pmid = {37768955}, issn = {1932-6203}, abstract = {PURPOSE: This study aimed to investigate the genetic diversity of Wolbachia in field-caught bed bug species in Paris areas.<br><br>METHODS: The bed bug specimens were captured from various infested localities in Paris and surrounding cities. They belonged to diverse life stages, including egg, nymph, and adult. They were then identified using morphological and molecular approaches. Furthermore, Wolbachia was detected, and its genetic diversity was investigated by conventional PCR of 16S-rRNA and Wolbachia surface protein (wsp) genes.<br><br>RESULTS: A total of 256 bed bug specimens belonging to various life stages [adult (183 specimens), nymph (48), and egg (25)] were captured from seven private apartments, five social apartments, three houses, two immigrant residences, and one retirement home situated in 10 districts of Paris and 8 surrounding cities. They were identified as Cimex lectularius (237 specimens) and C. hemipterus (19) using morphological and molecular approaches. The presence and diversity of Wolbachia were ascertained by targeting 16S-rRNA and wsp genes. Based on molecular analysis, 182 and 148 out of 256 processed specimens were positive by amplifying 16S-rRNA and wsp fragments, respectively. The inferred phylogenetic analysis with 16S-rRNA and wsp sequences displayed monophyletic Wolbachia strains clustering each one in three populations. The median-joining network, including the Wolbachia 16S-rRNA and wsp sequences of C. lectularius and C. hemipterous specimens, indicated a significant genetic differentiation among these populations in Paris areas which was consent with Neighbor-Joining analyses. A phylogenetic analysis of our heterogenic Wolbachia sequences with those reported from other arthropod species confirmed their belonging to supergroup F. Moreover, no difference between Wolbachia sequences from eggs, nymphs, and adults belonging to the same clade and between Wolbachia sequences of C. lectularius and C. hemipterus were observed after sequence alignment. Furthermore, no significant correlation was found between multiple geographical locations (or accomodation type) where bed bugs were collected and the genetic diversity of Wolbachia.<br><br>CONCLUSIONS: We highlight a significant heterogeneity within Wolbachia symbionts detected in C. lectularius and C. hemipterus. No correlation between Wolbachia species and bed bug species (C. lectularius versus C. hemipterus), physiological stages (egg, nymph, and adult), and sampling location was recorded in this study.}, }
@article {pmid37768069, year = {2023}, author = {Dittmer, J and Corretto, E and Štarhová Serbina, L and Michalik, A and Nováková, E and Schuler, H}, title = {Division of labor within psyllids: metagenomics reveals an ancient dual endosymbiosis with metabolic complementarity in the genus Cacopsylla.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0057823}, doi = {10.1128/msystems.00578-23}, pmid = {37768069}, issn = {2379-5077}, abstract = {Hemipteran insects are well-known for their ancient associations with beneficial bacterial endosymbionts, particularly nutritional symbionts that provide the host with essential nutrients such as amino acids or vitamins lacking in the host's diet. Therefore, these primary endosymbionts enable the exploitation of nutrient-poor food sources such as plant sap or vertebrate blood. In turn, the strictly host-associated lifestyle strongly impacts the genome evolution of the endosymbionts, resulting in small and degraded genomes. Over time, even the essential nutritional functions can be compromised, leading to the complementation or replacement of an ancient endosymbiont by another, more functionally versatile bacterium. Herein, we provide evidence for a dual primary endosymbiosis in several psyllid species. Using metagenome sequencing, we produced the complete genome sequences of both the primary endosymbiont "Candidatus Carsonella ruddii" and an as yet uncharacterized Enterobacteriaceae bacterium from four species of the genus Cacopsylla. The latter represents a new psyllid-associated endosymbiont clade for which we propose the name "Candidatus Psyllophila symbiotica." Fluorescent in situ hybridization confirmed the co-localization of both endosymbionts in the bacteriome. The metabolic repertoire of Psyllophila is highly conserved across host species and complements the tryptophan biosynthesis pathway that is incomplete in the co-occurring Carsonella. Unlike co-primary endosymbionts in other insects, the genome of Psyllophila is almost as small as the one of Carsonella, indicating an ancient co-obligate endosymbiosis rather than a recent association to rescue a degrading primary endosymbiont. IMPORTANCE Heritable beneficial bacterial endosymbionts have been crucial for the evolutionary success of numerous insects by enabling the exploitation of nutritionally limited food sources. Herein, we describe a previously unknown dual endosymbiosis in the psyllid genus Cacopsylla, consisting of the primary endosymbiont "Candidatus Carsonella ruddii" and a co-occurring Enterobacteriaceae bacterium for which we propose the name "Candidatus Psyllophila symbiotica." Its localization within the bacteriome and its small genome size confirm that Psyllophila is a co-primary endosymbiont widespread within the genus Cacopsylla. Despite its highly eroded genome, Psyllophila perfectly complements the tryptophan biosynthesis pathway that is incomplete in the co-occurring Carsonella. Moreover, the genome of Psyllophila is almost as small as Carsonella's, suggesting an ancient dual endosymbiosis that has now reached a precarious stage where any additional gene loss would make the system collapse. Hence, our results shed light on the dynamic interactions of psyllids and their endosymbionts over evolutionary time.}, }
@article {pmid37764903, year = {2023}, author = {Yüksel, E and Yıldırım, A and İmren, M and Canhilal, R and Dababat, AA}, title = {Xenorhabdus and Photorhabdus Bacteria as Potential Candidates for the Control of Culex pipiens L. (Diptera: Culicidae), the Principal Vector of West Nile Virus and Lymphatic Filariasis.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, doi = {10.3390/pathogens12091095}, pmid = {37764903}, issn = {2076-0817}, abstract = {Vector-borne diseases pose a severe threat to human and animal health. Culex pipiens L. (Diptera: Culicidae) is a widespread mosquito species and serves as a vector for the transmission of infectious diseases such as West Nile disease and Lymphatic Filariasis. Synthetic insecticides have been the prime control method for many years to suppress Cx. pipiens populations. However, recently, the use of insecticides has begun to be questioned due to the detrimental impact on human health and the natural environment. Therefore, many authorities urge the development of eco-friendly control methods that are nontoxic to humans. The bacterial associates [Xenorhabdus and Photorhabdus spp. (Enterobacterales: Morganellaceae)] of entomopathogenic nematodes (EPNs) (Sterinernema spp. and Heterorhabditis spp.) (Rhabditida: Heterorhabditidae and Steinernematidae) are one of the green approaches to combat a variety of insect pests. In the present study, the mosquitocidal activity of the cell-free supernatants and cell suspension (4 × 10[7] cells mL[-1]) of four different symbiotic bacteria (Xenorhabdus nematophila, X. bovienii, X. budapestensis, and P. luminescens subsp. kayaii) was assessed against different development stages of Cx. pipiens (The 1st/2nd and 3rd/4th instar larvae and pupa) under laboratory conditions. The bacterial symbionts were able to kill all the development stages with varying levels of mortality. The 1st/2nd instar larvae exhibited the highest susceptibility to the cell-free supernatants and cell suspensions of symbiotic bacteria and the efficacy of the cell-free supernatants and cell suspensions gradually declined with increasing phases of growth. The highest effectiveness was achieved by the X. bovienii KCS-4S strain inducing 95% mortality to the 1st/2nd instar larvae. The results indicate that tested bacterial symbionts have great potential as an eco-friendly alternative to insecticides.}, }
@article {pmid37764891, year = {2023}, author = {Margarita, V and Congiargiu, A and Diaz, N and Fiori, PL and Rappelli, P}, title = {Mycoplasma hominis and Candidatus Mycoplasma girerdii in Trichomonas vaginalis: Peaceful Cohabitants or Contentious Roommates?.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, doi = {10.3390/pathogens12091083}, pmid = {37764891}, issn = {2076-0817}, support = {2017SFBFER_004//Ministero dell'Istruzione, dell' Universit&#xe0; e della Ricerca/ ; }, abstract = {Trichomonas vaginalis is a pathogenic protozoan diffused worldwide capable of infecting the urogenital tract in humans, causing trichomoniasis. One of its most intriguing aspects is the ability to establish a close relationship with endosymbiotic microorganisms: the unique association of T. vaginalis with the bacterium Mycoplasma hominis represents, to date, the only example of an endosymbiosis involving two true human pathogens. Since its discovery, several aspects of the symbiosis between T. vaginalis and M. hominis have been characterized, demonstrating that the presence of the intracellular guest strongly influences the pathogenic characteristics of the protozoon, making it more aggressive towards host cells and capable of stimulating a stronger proinflammatory response. The recent description of a further symbiont of the protozoon, the newly discovered non-cultivable mycoplasma Candidatus Mycoplasma girerdii, makes the picture even more complex. This review provides an overview of the main aspects of this complex microbial consortium, with particular emphasis on its effect on protozoan pathobiology and on the interplays among the symbionts.}, }
@article {pmid37764139, year = {2023}, author = {Santana, MCO and Chourabi, K and Cantanhêde, LM and Cupolillo, E}, title = {Exploring Host-Specificity: Untangling the Relationship between Leishmania (Viannia) Species and Its Endosymbiont Leishmania RNA Virus 1.}, journal = {Microorganisms}, volume = {11}, number = {9}, pages = {}, doi = {10.3390/microorganisms11092295}, pmid = {37764139}, issn = {2076-2607}, support = {001//National Council for Scientific and Technological Development/ ; 302622/2017-9//Coordena&#xe7;&#xe3;o de Aperfeicoamento de Pessoal de N&#xed;vel Superior/ ; (E26-202.569/2019), (E26-210.038/2020), (E-26/205.730/2022 and 205.731/2022)//Funda&#xe7;&#xe3;o Carlos Chagas Filho de Amparo &#xe0; Pesquisa do Estado do Rio de Janeiro/ ; Edital 16/2014//Funda&#xe7;&#xe3;o de Amparo ao Desenvolvimento das A&#xe7;&#xf5;es Cient&#xed;ficas e Tecnol&#xf3;gicas e &#xe0; Pesquisa-FAPERO/ ; }, abstract = {A relevant aspect in the epidemiology of Tegumentary Leishmaniasis (TL) are the Leishmania parasites carrying a viral endosymbiont, Leishmania RNA Virus 1 (LRV1), a dsRNA virus. Leishmania parasites carrying LRV1 are prone to causing more severe TL symptoms, increasing the likelihood of unfavorable clinical outcomes. LRV1 has been observed in the cultured strains of five L. (Viannia) species, and host specificity was suggested when studying the LRV1 from L. braziliensis and L. guyanensis strains. The coevolution hypothesis of LRV1 and Leishmania was based on phylogenetic analyses, implying an association between LRV1 genotypes, Leishmania species, and their geographic origins. This study aimed to investigate LRV1 specificity relative to Leishmania (Viannia) species hosts by analyzing LRV1 from L. (Viannia) species. To this end, LRV1 was screened in L. (Viannia) species other than L. braziliensis or L. guyanensis, and it was detected in 11 out of 15 L. naiffi and two out of four L. shawi. Phylogenetic analyses based on partial LRV1 genomic sequencing supported the hypothesis of host specificity, as LRV1 clustered according to their respective Leishmania species' hosts. These findings underscore the importance of investigating Leishmania and LRV1 coevolution and its impact on Leishmania (Viannia) species dispersion and pathogenesis in the American Continent.}, }
@article {pmid37758795, year = {2023}, author = {Garcia Guizzo, M and Meneses, C and Amado Cecilio, P and Hessab Alvarenga, P and Sonenshine, D and Ribeiro, JM}, title = {Optimizing tick artificial membrane feeding for Ixodes scapularis.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {16170}, pmid = {37758795}, issn = {2045-2322}, support = {Award number: Z01 AI000810-18//Intramural Research Program of the National Institute of Allergy and Infectious Diseases/ ; Award number: AI00115203//Intramural Research Program of the National Institute of Allergy and Infectious Diseases/ ; }, abstract = {Artificial membrane feeding (AMF) is a powerful and versatile technique with a wide range of applications in the study of disease vectors species. Since its first description, AMF has been under constant optimization and standardization for different tick species and life stages. In the USA, Ixodes scapularis is the main vector of tick-borne zoonoses including the pathogens causing Lyme disease in humans and animals. Seeking to improve the overall fitness of I. scapularis adult females fed artificially, here, we have optimized the AMF technique, considerably enhancing attachment rate, engorgement success, egg laying, and egg hatching compared to those described in previous studies. Parameters such as the membrane thickness and the light/dark cycle to which the ticks were exposed were refined to more closely reflect the tick's natural behavior and life cycle. Additionally, ticks were fed on blood only, blood + ATP or blood + ATP + gentamicin. The artificial feeding of ticks on blood only was successful and generated a progeny capable of feeding naturally on a host, i.e., mice. Adding ATP as a feeding stimulant did not improve tick attachment or engorgement. Notably, the administration of gentamicin, an antibiotic commonly used in tick AMF to prevent microbial contamination, negatively impacted Rickettsia buchneri endosymbiont levels in the progeny of artificially fed ticks. In addition, gentamicin-fed ticks showed a reduction in oviposition success compared to ticks artificially fed on blood only, discouraging the use of antibiotics in AMF. Overall, our data suggest that the AMF of adult females on blood only, in association with the natural feeding of their progeny on mice, might be used as an integrated approach in tick rearing, eliminating the use of protected species under the Animal Welfare Act (AWA). Of note, although optimized for I. scapularis adult ticks, I. scapularis nymphs, other tick species, and sand flies could also be fed using the membrane described in this study, indicating that it might be a suitable alternative for the artificial feeding of a variety of hematophagous species.}, }
@article {pmid37754731, year = {2023}, author = {Heidari Latibari, M and Moravvej, G and Rakhshani, E and Karimi, J and Arias-Penna, DC and Butcher, BA}, title = {Arsenophonus: A Double-Edged Sword of Aphid Defense against Parasitoids.}, journal = {Insects}, volume = {14}, number = {9}, pages = {}, doi = {10.3390/insects14090763}, pmid = {37754731}, issn = {2075-4450}, support = {No. 3/48846//Ph.D. project, the Ferdowsi University of Mashhad, Iran/ ; IR-UOZ-GR-3949//University of Zabol/ ; N42A650262//National Research Council of Thailand (NRCT) and Chulalongkorn University/ ; }, abstract = {It is widely accepted that endosymbiont interactions with their hosts have significant effects on the fitness of both pests and beneficial species. A particular type of endosymbiosis is that of beneficial associations. Facultative endosymbiotic bacteria are associated with elements that provide aphids with protection from parasitoids. Arsenophonus (Enterobacterales: Morganellaceae) is one such endosymbiont bacterium, with infections being most commonly found among the Hemiptera species. Here, black cowpea aphids (BCAs), Aphis craccivora Koch (Hemiptera: Aphididae), naturally infected with Arsenophonus, were evaluated to determine the defensive role of this bacterium in BCAs against two parasitoid wasp species, Binodoxys angelicae and Lysiphlebus fabarum (both in Braconidae: Aphidiinae). Individuals of the black cowpea aphids infected with Arsenophonus were treated with a blend of ampicillin, cefotaxime, and gentamicin (Arsenophonus-reduced infection, AR) and subsequently subjected to parasitism assays. The results showed that the presence of Arsenophonus does not prevent BCAs from being parasitized by either B. angelicae or L. fabarum. Nonetheless, in BCA colonies parasitized by B. angelicae, the endosymbiont delayed both the larval maturation period and the emergence of the adult parasitoid wasps. In brief, Arsenophonus indirectly limits the effectiveness of B. angelicae parasitism by decreasing the number of emerged adult wasps. Therefore, other members of the BCA colony can survive. Arsenophonus acts as a double-edged sword, capturing the complex dynamic between A. craccivora and its parasitoids.}, }
@article {pmid37752965, year = {2023}, author = {Scharfenstein, HJ and Alvarez-Roa, C and Peplow, LM and Buerger, P and Chan, WY and van Oppen, MJH}, title = {Chemical mutagenesis and thermal selection of coral photosymbionts induce adaptation to heat stress with trait trade-offs.}, journal = {Evolutionary applications}, volume = {16}, number = {9}, pages = {1549-1567}, pmid = {37752965}, issn = {1752-4571}, abstract = {Despite the relevance of heat-evolved microalgal endosymbionts to coral reef restoration, to date, few Symbiodiniaceae strains have been thermally enhanced via experimental evolution. Here, we investigated whether the thermal tolerance of Symbiodiniaceae can be increased through chemical mutagenesis followed by thermal selection. Strains of Durusdinium trenchii, Fugacium kawagutii and Symbiodinium pilosum were exposed to ethyl methanesulfonate to induce random mutagenesis, and then underwent thermal selection at high temperature (31/33°C). After 4.6-5 years of experimental evolution, the in vitro thermal tolerance of these strains was assessed via reciprocal transplant experiments to ambient (27°C) and elevated (31/35°C) temperatures. Growth, photosynthetic efficiency, oxidative stress and nutrient use were measured to compare thermal tolerance between strains. Heat-evolved D. trenchii, F. kawagutii and S. pilosum strains all exhibited increased photosynthetic efficiency under thermal stress. However, trade-offs in growth rates were observed for the heat-evolved D. trenchii lineage at both ambient and elevated temperatures. Reduced phosphate and nitrate uptake rates in F. kawagutii and S. pilosum heat-evolved lineages, respectively, suggest alterations in nutrition resource usage and allocation processes may have occurred. Increased phosphate uptake rates of the heat-evolved D. trenchii strain indicate that experimental evolution resulted in further trade-offs in this species. These findings deepen our understanding of the physiological responses of Symbiodiniaceae cultures to thermal selection and their capacity to adapt to elevated temperatures. The new heat-evolved Symbiodiniaceae developed here may be beneficial for coral reef restoration efforts if their enhanced thermal tolerance can be conferred in hospite.}, }
@article {pmid37752841, year = {2023}, author = {Lyndby, NH and Murthy, S and Bessette, S and Jakobsen, SL and Meibom, A and Kühl, M}, title = {Non-invasive investigation of the morphology and optical properties of the upside-down jellyfish Cassiopea with optical coherence tomography.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2007}, pages = {20230127}, doi = {10.1098/rspb.2023.0127}, pmid = {37752841}, issn = {1471-2954}, abstract = {The jellyfish Cassiopea largely cover their carbon demand via photosynthates produced by microalgal endosymbionts, but how holobiont morphology and tissue optical properties affect the light microclimate and symbiont photosynthesis in Cassiopea remain unexplored. Here, we use optical coherence tomography (OCT) to study the morphology of Cassiopea medusae at high spatial resolution. We include detailed 3D reconstructions of external micromorphology, and show the spatial distribution of endosymbionts and white granules in the bell tissue. Furthermore, we use OCT data to extract inherent optical properties from light-scattering white granules in Cassiopea, and show that granules enhance local light-availability for symbionts in close proximity. Individual granules had a scattering coefficient of µs = 200-300 cm[-1], and scattering anisotropy factor of g = 0.7, while large tissue-regions filled with white granules had a lower µs = 40-100 cm[-1], and g = 0.8-0.9. We combined OCT information with isotopic labelling experiments to investigate the effect of enhanced light-availability in whitish tissue regions. Endosymbionts located in whitish tissue exhibited significantly higher carbon fixation compared to symbionts in anastomosing tissue (i.e. tissue without light-scattering white granules). Our findings support previous suggestions that white granules in Cassiopea play an important role in the host modulation of the light-microenvironment.}, }
@article {pmid37751380, year = {2023}, author = {Ward, PS and Cash, EI and Ferger, K and Escalona, M and Sahasrabudhe, R and Miller, C and Toffelmier, E and Fairbairn, C and Seligmann, W and Shaffer, HB and Tsutsui, ND}, title = {Reference genome of the bicolored carpenter ant, Camponotus vicinus.}, journal = {The Journal of heredity}, volume = {}, number = {}, pages = {}, doi = {10.1093/jhered/esad055}, pmid = {37751380}, issn = {1465-7333}, abstract = {Carpenter ants in the genus Camponotus are large, conspicuous ants that are abundant and ecologically influential in many terrestrial ecosystems. The bicolored carpenter ant, C. vicinus Mayr, is distributed across a wide range of elevations and latitudes in western North America, where it is a prominent scavenger and predator. Here, we present a high-quality genome assembly of C. vicinus from a sample collected in Sonoma County, California, near the type locality of the species. This genome assembly consists of 38 scaffolds spanning 302.74 Mb, with contig N50 of 15.9Mb, scaffold N50 of 19.9 Mb, and BUSCO completeness of 99.2%. This genome sequence will be a valuable resource for exploring the evolutionary ecology of C. vicinus and carpenter ants generally. It also provides an important tool for clarifying cryptic diversity within the C. vicinus species complex, a genetically diverse set of populations, some of which are quite localized and of conservation interest.}, }
@article {pmid37749181, year = {2023}, author = {Štarhová Serbina, L and Corretto, E and Enciso Garcia, JS and Berta, M and Giovanelli, T and Dittmer, J and Schuler, H}, title = {Seasonal wild dance of dual endosymbionts in the pear psyllid Cacopsylla pyricola (Hemiptera: Psylloidea).}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {16038}, pmid = {37749181}, issn = {2045-2322}, abstract = {Most sap-feeding insects maintain obligate relationships with endosymbiotic bacteria that provide their hosts with essential nutrients. However, knowledge about the dynamics of endosymbiont titers across seasons in natural host populations is scarce. Here, we used quantitative PCR to investigate the seasonal dynamics of the dual endosymbionts "Candidatus Carsonella ruddii" and "Ca. Psyllophila symbiotica" in a natural population of the pear psyllid Cacopsylla pyricola (Hemiptera: Psylloidea: Psyllidae). Psyllid individuals were collected across an entire year, covering both summer and overwintering generations. Immatures harboured the highest titers of both endosymbionts, while the lowest endosymbiont density was observed in males. The density of Carsonella remained high and relatively stable across the vegetative period of the pear trees, but significantly dropped during the non-vegetative period, overlapping with C. pyricola's reproductive diapause. In contrast, the titer of Psyllophila was consistently higher than Carsonella's and exhibited fluctuations throughout the sampling year, which might be related to host age. Despite a tightly integrated metabolic complementarity between Carsonella and Psyllophila, our findings highlight differences in their density dynamics throughout the year, that might be linked to their metabolic roles at different life stages of the host.}, }
@article {pmid37748072, year = {2023}, author = {Maegele, I and Rupp, S and Özbek, S and Guse, A and Hambleton, EA and Holstein, TW}, title = {A predatory gastrula leads to symbiosis-independent settlement in Aiptasia.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {40}, pages = {e2311872120}, doi = {10.1073/pnas.2311872120}, pmid = {37748072}, issn = {1091-6490}, support = {SFB1324-A5//Deutsche Forschungsgemeinschaft (DFG)/ ; D.A.C.H.//Deutsche Forschungsgemeinschaft (DFG)/ ; SFB1324-B7//Deutsche Forschungsgemeinschaft (DFG)/ ; Oe416/8-1//Deutsche Forschungsgemeinschaft (DFG)/ ; 724715//European Resuscitation Council (ERC)/ ; }, abstract = {The planula larvae of the sea anemone Aiptasia have so far not been reported to complete their life cycle by undergoing metamorphosis into adult forms. This has been a major obstacle in their use as a model for coral-dinoflagellate endosymbiosis. Here, we show that Aiptasia larvae actively feed on crustacean nauplii, displaying a preference for live prey. This feeding behavior relies on functional stinging cells, indicative of complex neuronal control. Regular feeding leads to significant size increase, morphological changes, and efficient settlement around 14 d postfertilization. Surprisingly, the presence of dinoflagellate endosymbionts does not affect larval growth or settlement dynamics but is crucial for sexual reproduction. Our findings finally close Aiptasia's life cycle and highlight the functional nature of its larvae, as in Haeckel's Gastrea postulate, yet reveal its active carnivory, thus contributing to our understanding of early metazoan evolution.}, }
@article {pmid37744901, year = {2023}, author = {Zhao, C and Wang, L and Zhang, K and Zhu, X and Li, D and Ji, J and Luo, J and Cui, J}, title = {Variation of Helicoverpa armigera symbionts across developmental stages and geographic locations.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1251627}, pmid = {37744901}, issn = {1664-302X}, abstract = {Cotton bollworm (Helicoverpa armigera) poses a global problem, causing substantial economic and ecological losses. Endosymbionts in insects play crucial roles in multiple insect biological processes. However, the interactions between H. armigera and its symbionts have not been well characterized to date. We investigated the symbionts of H. armigera in the whole life cycle from different geographical locations. In the whole life cycle of H. armigera, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacteria at the phylum level, while Enterococcus, Enterobacter, Glutamicibacter, and Bacillus were the four dominant bacteria at the genus level. Furthermore, high similarity in symbiotic bacterial community was observed in different stages of H. armigera, which were dominated by Enterococcus and Enterobacter. In fields, the dominant bacteria were Proteobacteria and Bacteroidetes, whereas, in the laboratory, the dominant bacteria were Proteobacteria. At the genus level, the dominant bacteria in cotton bollworm eggs of wild populations were Enterobacter, Morganella, Lactococcus, Asaia, Apibacter, and Enterococcus, and the subdominant bacteria were Bartonella, Pseudomonas, and Orbus. Moreover, the symbionts varied with geographical locations, and the closer the geographical distance, the more similar the microbial composition. Taken together, our study identifies and compares the symbiont variation along with geographical gradients and host development dynamic and reveals the high flexibility of microbiome communities in H. armigera, which probably benefits for the successful survival in a complicated changing environment.}, }
@article {pmid37740026, year = {2023}, author = {Kumar, V and Nautiyal, CS}, title = {Endophytes Modulate Plant Genes: Present Status and Future Perspectives.}, journal = {Current microbiology}, volume = {80}, number = {11}, pages = {353}, pmid = {37740026}, issn = {1432-0991}, mesh = {*Genes, Plant ; Endophytes/genetics ; Genomics ; *Microbiota ; Plant Development ; }, abstract = {Interactions among endophytes and plants are widespread and can vary from neutral or positive or negative. Plants are continually in a functionally dynamic state due to interactions with diverse endophytic microorganisms, which produce various metabolic substances. Through quorum sensing, these substances not only help endophytes to outcompete other host-associated pathogens or microbes but also allow them to overcome the plant immune system. Manifold interactions between endophytic microbiota cause a reflective impact on the host plant functioning and the development of 'endobiomes,' by synthesizing chemicals that fill the gap between host and endophytes. Despite the advances in the field, specific mechanisms for the endophytes' precise methods to modulate plant genome and their effects on host plants remain poorly understood. Deeper genomic exploration can provide a locked away understanding of the competencies of endophytes and their conceivable function in host growth and health. Endophytes also can modify host metabolites, which could manipulate plants' growth, adaptation, and proliferation, and can be a more exciting and puzzling topic that must be properly investigated. The consequence of the interaction of endophytes on the host genome was analyzed as it can help unravel the gray areas of endophytes about which very little or no knowledge exists. This review discusses the recent advances in understanding the future challenges in the emerging research investigating how endosymbionts affect the host's metabolism and gene expression as an effective strategy for imparting resistance to biotic and abiotic challenges.}, }
@article {pmid37725257, year = {2023}, author = {Wagner, T and Bangoura, B and Wiedmer, S and Daugschies, A and Dunay, IR}, title = {Phytohormones regulate asexual Toxoplasma gondii replication.}, journal = {Parasitology research}, volume = {}, number = {}, pages = {}, pmid = {37725257}, issn = {1432-1955}, abstract = {The protozoan Toxoplasma gondii (T. gondii) is a zoonotic disease agent causing systemic infection in warm-blooded intermediate hosts including humans. During the acute infection, the parasite infects host cells and multiplies intracellularly in the asexual tachyzoite stage. In this stage of the life cycle, invasion, multiplication, and egress are the most critical events in parasite replication. T. gondii features diverse cell organelles to support these processes, including the apicoplast, an endosymbiont-derived vestigial plastid originating from an alga ancestor. Previous studies have highlighted that phytohormones can modify the calcium-mediated secretion, e.g., of adhesins involved in parasite movement and cell invasion processes. The present study aimed to elucidate the influence of different plant hormones on the replication of asexual tachyzoites in a human foreskin fibroblast (HFF) host cell culture. T. gondii replication was measured by the determination of T. gondii DNA copies via qPCR. Three selected phytohormones, namely abscisic acid (ABA), gibberellic acid (GIBB), and kinetin (KIN) as representatives of different plant hormone groups were tested. Moreover, the influence of typical cell culture media components on the phytohormone effects was assessed. Our results indicate that ABA is able to induce a significant increase of T. gondii DNA copies in a typical supplemented cell culture medium when applied in concentrations of 20 ng/μl or 2 ng/μl, respectively. In contrast, depending on the culture medium composition, GIBB may potentially serve as T. gondii growth inhibitor and may be further investigated as a potential treatment for toxoplasmosis.}, }
@article {pmid37723238, year = {2023}, author = {Longley, R and Robinson, A and Liber, JA and Bryson, AE and Morales, DP and LaButti, K and Riley, R and Mondo, SJ and Kuo, A and Yoshinaga, Y and Daum, C and Barry, K and Grigoriev, IV and Desirò, A and Chain, PSG and Bonito, G}, title = {Comparative genomics of Mollicutes-related endobacteria supports a late invasion into Mucoromycota fungi.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {948}, pmid = {37723238}, issn = {2399-3642}, support = {DE-AC02-05CH11231//U.S. Department of Energy (DOE)/ ; LANLF59T//U.S. Department of Energy (DOE)/ ; DEB 1737898//National Science Foundation (NSF)/ ; MICL02416//United States Department of Agriculture | National Institute of Food and Agriculture (NIFA)/ ; }, abstract = {Diverse members of early-diverging Mucoromycota, including mycorrhizal taxa and soil-associated Mortierellaceae, are known to harbor Mollicutes-related endobacteria (MRE). It has been hypothesized that MRE were acquired by a common ancestor and transmitted vertically. Alternatively, MRE endosymbionts could have invaded after the divergence of Mucoromycota lineages and subsequently spread to new hosts horizontally. To better understand the evolutionary history of MRE symbionts, we generated and analyzed four complete MRE genomes from two Mortierellaceae genera: Linnemannia (MRE-L) and Benniella (MRE-B). These genomes include the smallest known of fungal endosymbionts and showed signals of a tight relationship with hosts including a reduced functional capacity and genes transferred from fungal hosts to MRE. Phylogenetic reconstruction including nine MRE from mycorrhizal fungi revealed that MRE-B genomes are more closely related to MRE from Glomeromycotina than MRE-L from the same host family. We posit that reductions in genome size, GC content, pseudogene content, and repeat content in MRE-L may reflect a longer-term relationship with their fungal hosts. These data indicate Linnemannia and Benniella MRE were likely acquired independently after their fungal hosts diverged from a common ancestor. This work expands upon foundational knowledge on minimal genomes and provides insights into the evolution of bacterial endosymbionts.}, }
@article {pmid37722758, year = {2023}, author = {Kolo, AO and Raghavan, R}, title = {Impact of endosymbionts on tick physiology and fitness.}, journal = {Parasitology}, volume = {}, number = {}, pages = {1-7}, doi = {10.1017/S0031182023000793}, pmid = {37722758}, issn = {1469-8161}, abstract = {Ticks transmit pathogens and harbour non-pathogenic, vertically transmitted intracellular bacteria termed endosymbionts. Almost all ticks studied to date contain 1 or more of Coxiella, Francisella, Rickettsia or Candidatus Midichloria mitochondrii endosymbionts, indicative of their importance to tick physiology. Genomic and experimental data suggest that endosymbionts promote tick development and reproductive success. Here, we review the limited information currently available on the potential roles endosymbionts play in enhancing tick metabolism and fitness. Future studies that expand on these findings are needed to better understand endosymbionts’ contributions to tick biology. This knowledge could potentially be applied to design novel strategies that target endosymbiont function to control the spread of ticks and pathogens they vector.}, }
@article {pmid37719127, year = {2023}, author = {Castañeda-Molina, Y and Marulanda-Moreno, SM and Saldamando-Benjumea, C and Junca, H and Moreno-Herrera, CX and Cadavid-Restrepo, G}, title = {Microbiome analysis of Spodoptera frugiperda (Lepidoptera, Noctuidae) larvae exposed to Bacillus thuringiensis (Bt) endotoxins.}, journal = {PeerJ}, volume = {11}, number = {}, pages = {e15916}, pmid = {37719127}, issn = {2167-8359}, abstract = {BACKGROUND: Spodoptera frugiperda (or fall armyworm, FAW) is a polyphagous pest native to Western Hemisphere and recently discovered in the Eastern Hemisphere. In Colombia, S. frugiperda is recognized as a pest of economic importance in corn. The species has genetically differentiated into two host populations named "corn" and "rice" strains. In 2012, a study made in central Colombia demonstrated that the corn strain is less susceptible to Bacillus thuringiensis (Bt) endotoxins (Cry1Ac and Cry 1Ab) than the rice strain. In this country, Bt transgenic corn has been extensively produced over the last 15 years. Since gut microbiota plays a role in the physiology and immunity of insects, and has been implicated in promoting the insecticidal activity of Bt, in this study an analysis of the interaction between Bt endotoxins and FAW gut microbiota was made. Also, the detection of endosymbionts was performed here, as they might have important implications in the biological control of a pest.<br><br>METHODS: The composition and diversity of microbiomes associated with larval specimens of S. frugiperda(corn strain) was investigated in a bioassay based on six treatments in the presence/absence of Bt toxins and antibiotics (Ab) through bacterial isolate analyses and by high throughput sequencing of the bacterial 16S rRNA gene. Additionally, species specific primers were used, to detect endosymbionts from gonads in S. frugiperda corn strain.<br><br>RESULTS: Firmicutes, Proteobacteria and Bacteroidota were the most dominant bacterial phyla found in S. frugiperda corn strain. No significant differences in bacteria species diversity and richness among the six treatments were found. Two species of Enterococcus spp., E. mundtii and E. casseliflavus were detected in treatments with Bt and antibiotics, suggesting that they are less susceptible to both of them. Additionally, the endosymbiont Arsenophonus was also identified on treatments in presence of Bt and antibiotics. The results obtained here are important since little knowledge exists about the gut microbiota on this pest and its interaction with Bt endotoxins. Previous studies made in Lepidoptera suggest that alteration of gut microbiota can be used to improve the management of pest populations, demonstrating the relevance of the results obtained in this work.}, }
@article {pmid37716961, year = {2023}, author = {Mfopit, YM and Engel, JS and Chechet, GD and Ibrahim, MAM and Signaboubo, D and Achukwi, DM and Mamman, M and Balogun, EO and Shuaibu, MN and Kabir, J and Kelm, S}, title = {Molecular detection of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts in wild population of tsetse flies collected in Cameroon, Chad and Nigeria.}, journal = {BMC microbiology}, volume = {23}, number = {1}, pages = {260}, pmid = {37716961}, issn = {1471-2180}, mesh = {Animals ; *Tsetse Flies ; *Wolbachia/genetics ; Cameroon ; Chad ; Nigeria ; *Glossinidae ; *Trypanosomiasis, African ; *Spiroplasma/genetics ; }, abstract = {BACKGROUND: Tsetse flies are cyclical vectors of African trypanosomiasis (AT). The flies have established symbiotic associations with different bacteria that influence certain aspects of their physiology. Vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by bacterial endosymbionts amongst other factors. Symbiotic interactions may provide an avenue for AT control. The current study provided prevalence of three tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria.<br><br>RESULTS: Tsetse flies were collected and dissected from five different locations. DNA was extracted and polymerase chain reaction used to detect presence of Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts, using species specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the three symbionts. Among infected flies, six (6.31%) had Wolbachia and Spiroplasma mixed infection. The overall symbiont prevalence was 0.88, 3.66 and 11.00% respectively, for Sodalis glossinidius, Spiroplasma species and Wolbachia endosymbionts. Prevalence varied between countries and tsetse fly species. Neither Spiroplasma species nor S. glossinidius were detected in samples from Cameroon and Nigeria respectively.<br><br>CONCLUSION: The present study revealed, for the first time, presence of Spiroplasma species infections in tsetse fly populations in Chad and Nigeria. These findings provide useful information on repertoire of bacterial flora of tsetse flies and incite more investigations to understand their implication in the vector competence of tsetse flies.}, }
@article {pmid37716699, year = {2023}, author = {Amses, K and Desiró, A and Bryson, A and Grigoriev, I and Mondo, S and Lipzen, A and LaButti, K and Riley, R and Singan, V and Salazar-Hamm, P and King, J and Ballou, E and Pawlowska, T and Adeleke, R and Bonito, G and Uehling, J}, title = {Convergent reductive evolution and host adaptation in Mycoavidus bacterial endosymbionts of Mortierellaceae fungi.}, journal = {Fungal genetics and biology : FG &amp; B}, volume = {}, number = {}, pages = {103838}, doi = {10.1016/j.fgb.2023.103838}, pmid = {37716699}, issn = {1096-0937}, abstract = {Intimate associations between fungi and intracellular bacterial endosymbionts are becoming increasingly well understood. Phylogenetic analyses demonstrate that bacterial endosymbionts of Mucoromycota fungi are related either to free-living Burkholderia or Mollicutes species. The so-called Burkholderia-related endosymbionts or BRE comprise Mycoavidus, Mycetohabitans and Candidatus Glomeribacter gigasporarum. These endosymbionts are marked by genome contraction thought to be associated with intracellular selection. However, the conclusions drawn thus far are based on a very small subset of endosymbiont genomes, and the mechanisms leading to genome streamlining are not well understood. The purpose of this study was to better understand how intracellular existence shapes Mycoavidus and BRE functionally at the genome level. To this end we generated and analyzed 14 novel draft genomes for Mycoavidus living within the hyphae of Mortierellomycotina fungi. We found that our novel Mycoavidus genomes were significantly reduced compared to free-living Burkholderiales relatives. Using a genome-scale phylogenetic approach including the novel and available existing genomes of Mycoavidus, we show that the genus is an assemblage composed of two independently derived lineages including three well supported clades of Mycoavidus. Using a comparative genomic approach, we shed light on the functional implications of genome reduction, documenting shared and unique gene loss patterns between the three Mycoavidus clades. We found that many endosymbiont isolates demonstrate patterns of vertical transmission and host-specificity, but some are present in phylogenetically disparate hosts. We discuss how reductive evolution and host specificity reflect convergent adaptation to the intrahyphal selective landscape and commonalities of eukaryotic endosymbiont genome evolution.}, }
@article {pmid37716131, year = {2023}, author = {Bharathi, MD and Muthukumar, C and Sathishkumar, RS and Ramu, K and Murthy, MVR}, title = {First report on the occurrence of Gonyaulax polygramma bloom during the onset of Noctiluca scintillans bloom along the Tuticorin coast, southeast coast of India.}, journal = {Marine pollution bulletin}, volume = {195}, number = {}, pages = {115523}, doi = {10.1016/j.marpolbul.2023.115523}, pmid = {37716131}, issn = {1879-3363}, abstract = {Dense and green-coloured patches were encountered on the sea surface waters of the Tuticorin coast on 22[nd] October 2022. Microscopic investigation revealed that the discoloration is caused by plankton, green Noctiluca scintillans. In order to find out the causes that trigger the bloom of N. scintillans, plankton samples were collected for 5 days in fourteen days duration from 22[nd] October to 4[th] November. During the peak bloom period, the abundance and biovolume of N. scintillans reached 1.56 × 10[4] cells/L and 21.8 × 10[10]μm[3]/L, respectively. The highest concentration (73.65 mg/m[3]) of chlorophyll-a was recorded during blooming period that was caused by Gonyaulax polygramma and endosymbiont, Pedinomonas noctilucae in N. scintillans. Formation of G. polygramma bloom is being reported for the first time in Tuticorin, southeast coast of India, with a species abundance of 36.9 × 10[4] cells/L. Present study concluded that besides the optimum hydrological conditions and eutrophic nature of the system, abundant prey (G. polygramma) facilitated the N. scintillans bloom.}, }
@article {pmid37715236, year = {2023}, author = {ElKraly, OA and Awad, M and El-Saadany, HM and Hassanein, SE and Elrahman, TA and Elnagdy, SM}, title = {Impact of gut microbiota composition on black cutworm, Agrotis ipsilon (hufnagel) metabolic indices and pesticide degradation.}, journal = {Animal microbiome}, volume = {5}, number = {1}, pages = {44}, pmid = {37715236}, issn = {2524-4671}, abstract = {Endosymbionts are known to have significant effects on their insect hosts, including nutrition, reproduction, and immunity. Insects gut microbiota is a critical component that affects their physiological and behavioral characteristics. The black cutworm (BCW), Agrotis ipsilon, is an economically important lepidopteran pest that has a diverse gut microbiome composed of nine species belonging to three phyla: Proteobacteria, Actinobacteria, and Firmicutes. This study was conducted to investigate the diversity of gut bacteria isolated from BCW larvae and moths and their effects on metabolism and pesticide degradation. The bacterial isolates were identified using the 16 S rRNA gene. The study showed that the gut microbiome composition significantly affected the metabolism of BCW larvae. Based on the screening results of synthesis of digestive enzymes and pesticide degradation, Brachybacterium conglomeratum and Glutamicibacter sp were selected to perform the remaining experiments as single isolates and consortium. The consortium-fed larvae showed high metabolic indices compared to antibiotic-fed larvae and the control. The gut bacteria were also shown to degrade three pesticide groups. Concerns regarding the health risk of chlorpyrifos have been raised due to its extensive use in agriculture. The isolated B. conglomeratum was more effective in chlorpyrifos degradation than the consortium. Furthermore, the study also examined the presence of sex related endosymbionts (Wolbachia, Spiroplasma, and Rickettsia) in the reproductive tissues of adults. The outcomes demonstrated that none of the examined endosymbionts existed. In conclusion, the study highlights the importance of the gut microbiome in insect physiology and behavior and its potential applications in biotechnology. It provides insights into developing eco-friendly pest control and bioremediation strategies using gut bacteria.}, }
@article {pmid37715090, year = {2023}, author = {Nuschke, A and Sobey-Skelton, C and Dawod, B and Kelly, B and Tremblay, ML and Davis, C and Rioux, JA and Brewer, K}, title = {Use of Magnetotactic Bacteria as an MRI Contrast Agent for In Vivo Tracking of Adoptively Transferred Immune Cells.}, journal = {Molecular imaging and biology}, volume = {}, number = {}, pages = {}, pmid = {37715090}, issn = {1860-2002}, support = {Discovery Grant//Natural Science and Engineering Council (NSERC)/ ; Project Grant//IWK Health Centre/ ; }, abstract = {PURPOSE: In vivo immune cell tracking using MRI can be a valuable tool for studying the mechanisms underlying successful cancer therapies. Current cell labeling methods using superparamagnetic iron oxide (SPIO) lack the persistence to track the fate and location of transplanted cells long-term. Magnetospirillum magneticum is a commercially available, iron-producing bacterium that can be taken up by and live harmoniously within mammalian cells as magneto-endosymbionts (MEs). MEs have shown promise as labeling agents for in vivo stem and cancer cell tracking but have yet to be evaluated in immune cells. This pilot study examined ME labeling in myeloid-derived suppressor cells (MDSCs), cytotoxic T lymphocytes (CTLs), and dendritic cells (DCs) and its effects on cell purity, function, and MRI contrast.<br><br>PROCEDURES: MDSCs, CTLs, and DCs were incubated with MEs at various ME labeling ratios (MLR), and various biological metrics and iron uptake were assessed. For in vivo imaging, MDSCs were labeled overnight with either MEs or SPIO (Molday ION Rhodamine B) and injected into C3 tumor-bearing mice via tail vein injection 24&#xa0;days post-implant and scanned daily with MRI for 1&#xa0;week to assess cellular quantification.<br><br>RESULTS: Following incubations, MDSCs contained&#x2009;>&#x2009;0.6&#xa0;pg Fe/cell. CTLs achieved Fe loading of&#x2009;<&#x2009;0.5&#xa0;pg/cell, and DCs achieved Fe loading of&#x2009;~&#x2009;1.4&#xa0;pg/cell. The suppressive functionality of MDSCs at 1000 MLR was not affected by ME labeling but was affected at 2000 MLR. Markers of CTL dysfunction were not markedly affected by ME labeling nor were DC markers. In vivo data demonstrated that the MDSCs labeled with MEs generated sufficient contrast to be detectable using TurboSPI, similar to SPIO-labeled cells.<br><br>CONCLUSIONS: Cells can be labeled with sufficient numbers of MEs to be detectable with MRI without compromising cell viability. Care must be taken at higher concentrations of MEs, which may affect some cell types' functional activity and/or morphology. Immune cells with minimal phagocytic behavior have much lower iron content per cell after incubation with MEs vs SPIO; however, MEs can successfully be used as a contrast agent for phagocytic immune cells.}, }
@article {pmid37702423, year = {2023}, author = {Sakamoto, W and Takami, T}, title = {Plastid inheritance revisited: emerging role of organelle DNA degradation in angiosperms.}, journal = {Plant &amp; cell physiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/pcp/pcad104}, pmid = {37702423}, issn = {1471-9053}, support = {21H02508 21K06230 23H04959//Japan Society for the Promotion of Science/ ; }, abstract = {Plastids are essential organelles in angiosperms and show non-Mendelian inheritance due to their evolution as endosymbionts. In approximately 80% of angiosperms, plastids are thought to be inherited from the maternal parent, whereas other species transmit plastids biparentally. Maternal inheritance can be generally explained by the stochastic segregation of maternal plastids after fertilization because the zygote is overwhelmed by the maternal cytoplasm. In contrast, biparental inheritance shows transmission of organelles from both parents. In some species, maternal inheritance is not absolute and paternal leakage occurs at a very low frequency (~10-5). A key process controlling the inheritance mode lies in the behavior of plastids during male gametophyte (pollen) development, with accumulating evidence indicating that the plastids themselves or their DNAs are eliminated during pollen maturation or at fertilization. Cytological observations in numerous angiosperm species have revealed several critical steps that mutually influence the degree of plastid transmission quantitatively among different species. This review revisits plastid inheritance and focuses on the mechanistic viewpoint. Particularly, we focus on a recent finding demonstrating that both low temperature and plastid DNA degradation mediated by the organelle exonuclease DPD1 influence the degree of paternal leakage significantly in tobacco. Given these findings, we also highlight the emerging role of DPD1 in organelle DNA degradation.}, }
@article {pmid37695720, year = {2023}, author = {Kryukova, NA and Kryukov, VY and Polenogova, OV and Chertkova, &#x415;&#x410; and Tyurin, MV and Rotskaya, UN and Alikina, T and Kabilov, &#x41c;R and Glupov, VV}, title = {The endosymbiotic bacterium Wolbachia (Rickettsiales) alters larval metabolism of the parasitoid Habrobracon hebetor (Hymenoptera: Braconidae).}, journal = {Archives of insect biochemistry and physiology}, volume = {}, number = {}, pages = {e22053}, doi = {10.1002/arch.22053}, pmid = {37695720}, issn = {1520-6327}, support = {//Federal Fundamental Scientific Research Program/ ; //Russian Science Foundation/ ; 23-24-00259//The Russian Science Foundation/ ; 1021051703454-5-1.6.12//The Federal Fundamental Scientific Research Program/ ; }, abstract = {Infection of intestinal tissues with Wolbachia has been found in Habrobracon hebetor. There are not many studies on the relationship between Habrobracon and Wolbachia, and they focus predominantly on the sex index of an infected parasitoid, its fertility, and behavior. The actual role of Wolbachia in the biology of Habrobracon is not yet clear. The method of complete eradication of Wolbachia in the parasitoid was developed here, and effects of the endosymbiont on the host's digestive metabolism were compared between two lines of the parasitoid (Wolbachia-positive and Wolbachia-negative). In the gut of Wolbachia[+] larvae, lipases' activity was higher almost twofold, and activities of acid proteases, esterases, and trehalase were 1.5-fold greater than those in the Wolbachia[-] line. Analyses of larval homogenates revealed that Wolbachia[+] larvae accumulate significantly more lipids and have a lower amount of pyruvate as compared to Wolbachia[-] larvae. The presented results indicate significant effects of the intracellular symbiotic bacterium Wolbachia on the metabolism of H. hebetor larvae and on the activity of its digestive enzymes.}, }
@article {pmid37690114, year = {2023}, author = {Manzano-Marn, A and Kvist, S and Oceguera-Figueroa, A}, title = {Evolution of an alternative genetic code in the Providencia symbiont of the haematophagous leech Haementeria acuecueyetzin.}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evad164}, pmid = {37690114}, issn = {1759-6653}, abstract = {Strict blood-feeding animals are confronted with a strong B vitamin de_ciency. Blood-feeding leeches from the Glossiphoniidae family, similarly to haematophagous insects, have evolved specialised organs called bacteriomes to harbour symbiotic bacteria. Leeches of the Haementeria genus have two pairs of globular bacteriomes attached to the oesophagus which house intracellular 'Candidatus Providencia siddallii' bacteria. Previous work analysing a draft genome of the Providencia symbiont of the Mexican leech Haementeria officinalis showed that, in this species, the bacteria hold a reduced genome capable of synthesising B vitamins. In this work, we aimed to expand our knowledge on the diversity and evolution of Providencia symbionts of Haementeria. For this purpose, we sequenced the symbiont genomes of three selected leech species. We found that all genomes are highly syntenic and have kept a stable genetic repertoire, mirroring ancient insect endosymbionts. Additionally, we found B vitamin pathways to be conserved among these symbionts, pointing to a conserved symbiotic role. Lastly and most notably, we found that the symbiont of Haementeria acuecueyetzin has evolved an alternative genetic code, affecting a portion of its proteome and showing evidence of a lineage-specific and likely intermediate stage of genetic code reassignment.}, }
@article {pmid37686049, year = {2023}, author = {Zhang, Z and Zhang, J and Chen, Q and He, J and Li, X and Wang, Y and Lu, Y}, title = {Complete De Novo Assembly of Wolbachia Endosymbiont of Frankliniella intonsa.}, journal = {International journal of molecular sciences}, volume = {24}, number = {17}, pages = {}, doi = {10.3390/ijms241713245}, pmid = {37686049}, issn = {1422-0067}, support = {31672031, 32272537//National Natural Science Foundation of China/ ; 2021C02003//Key Research and Development Program of Zhejiang Province, China/ ; 2022YFD1401204, 2022YFC2601405//Key R&amp;D Program of China/ ; }, abstract = {As an endosymbiont, Wolbachia exerts significant effects on the host, including on reproduction, immunity, and metabolism. However, the study of Wolbachia in Thysanopteran insects, such as flower thrips Frankliniella intonsa, remains limited. Here, we assembled a gap-free looped genome assembly of Wolbachia strain wFI in a length of 1,463,884 bp (GC content 33.80%), using Nanopore long reads and Illumina short reads. The annotation of wFI identified a total of 1838 protein-coding genes (including 85 pseudogenes), 3 ribosomal RNAs (rRNAs), 35 transfer RNAs (tRNAs), and 1 transfer-messenger RNA (tmRNA). Beyond this basic description, we identified mobile genetic elements, such as prophage and insertion sequences (ISs), which make up 17% of the entire wFI genome, as well as genes involved in riboflavin and biotin synthesis and metabolism. This research lays the foundation for understanding the nutritional mutualism between Wolbachia and flower thrips. It also serves as a valuable resource for future studies delving into the intricate interactions between Wolbachia and its host.}, }
@article {pmid37673069, year = {2023}, author = {Harumoto, T}, title = {Self-stabilization mechanism encoded by a bacterial toxin facilitates reproductive parasitism.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2023.08.032}, pmid = {37673069}, issn = {1879-0445}, abstract = {A wide variety of maternally transmitted endosymbionts in insects are associated with reproductive parasitism, whereby they interfere with host reproduction to increase the ratio of infected females and spread within populations.[1][,][2] Recent successes in identifying bacterial factors responsible for reproductive parasitism[3][,][4][,][5][,][6][,][7] as well as further omics approaches[8][,][9][,][10][,][11][,][12] have highlighted the common appearance of deubiquitinase domains, although their biological roles-in particular, how they link to distinct manipulative phenotypes-remain poorly defined. Spiroplasma poulsonii is a helical and motile bacterial endosymbiont of Drosophila,[13][,][14] which selectively kills male progeny with a male-killing toxin Spaid (S. poulsonii androcidin), which encodes an ovarian tumor (OTU) deubiquitinase domain.[6] Artificial expression of Spaid in flies reproduces male-killing-associated pathologies that include abnormal apoptosis and neural defects during embryogenesis[6][,][15][,][16][,][17][,][18][,][19]; moreover, it highly accumulates on the dosage-compensated male X chromosome,[20] congruent with cellular defects such as the DNA damage/chromatin bridge breakage specifically induced upon that chromosome.[6][,][21][,][22][,][23] Here, I show that without the function of OTU, Spaid is polyubiquitinated and degraded through the host ubiquitin-proteasome pathway, leading to the attenuation of male-killing activity as shown previously.[6] Furthermore, I find that Spaid utilizes its OTU domain to deubiquitinate itself in an intermolecular manner. Collectively, the deubiquitinase domain of Spaid serves as a self-stabilization mechanism to facilitate male killing in flies, optimizing a molecular strategy of endosymbionts that enables the efficient manipulation of the host at a low energetic cost.}, }
@article {pmid37669272, year = {2023}, author = {Lau, MJ and Dutra, HLC and Jones, MJ and McNulty, BP and Diaz, AM and Ware-Gilmore, F and McGraw, EA}, title = {Jamestown Canyon virus is transmissible by Aedes aegypti and is only moderately blocked by Wolbachia co-infection.}, journal = {PLoS neglected tropical diseases}, volume = {17}, number = {9}, pages = {e0011616}, doi = {10.1371/journal.pntd.0011616}, pmid = {37669272}, issn = {1935-2735}, abstract = {Jamestown Canyon virus (JCV), a negative-sense arbovirus, is increasingly common in the upper Midwest of the USA. Transmitted by a range of mosquito genera, JCV's primary amplifying host is white-tailed deer. Aedes aegypti is responsible for transmitting various positive-sense viruses globally including dengue (DENV), Zika, chikungunya, and Yellow Fever. Ae. aegypti's distribution, once confined to the tropics, is expanding, in part due to climate change. Wolbachia, an insect endosymbiont, limits the replication of co-infecting viruses inside insects. The release and spread of the symbiont into Ae. aegypti populations have been effective in reducing transmission of DENV to humans, although the mechanism of Wolbachia-mediated viral blocking is still poorly understood. Here we explored JCV infection potential in Ae. aegypti, the nature of the vector's immune response, and interactions with Wolbachia infection. We show that Ae. aegypti is highly competent for JCV, which grows to high loads and rapidly reaches the saliva after an infectious blood meal. The mosquito immune system responds with strong induction of RNAi and JAK/STAT. Neither the direct effect of viral infection nor the energetic investment in immunity appears to affect mosquito longevity. Wolbachia infection blocked JCV only in the early stages of infection. Wolbachia-induced immunity was small compared to that of JCV, suggesting innate immune priming does not likely explain blocking. We propose two models to explain why Wolbachia's blocking of negative-sense viruses like JCV may be less than that of positive-sense viruses, relating to the slowdown of host protein synthesis and the triggering of interferon-like factors like Vago. In conclusion, we highlight the risk for increased human disease with the predicted future overlap of Ae. aegypti and JCV ranges. We suggest that with moderate Wolbachia-mediated blocking and distinct biology, negative-sense viruses represent a fruitful comparator model to other viruses for understanding blocking mechanisms in mosquitoes.}, }
@article {pmid37660098, year = {2023}, author = {Lin, C and Li, LJ and Ren, K and Zhou, SY and Isabwe, A and Yang, LY and Neilson, R and Yang, XR and Cytryn, E and Zhu, YG}, title = {Phagotrophic protists preserve antibiotic-resistant opportunistic human pathogens in the vegetable phyllosphere.}, journal = {ISME communications}, volume = {3}, number = {1}, pages = {94}, pmid = {37660098}, issn = {2730-6151}, support = {42090063//National Natural Science Foundation of China (National Science Foundation of China)/ ; 32061143015//National Natural Science Foundation of China (National Science Foundation of China)/ ; 32100331//National Natural Science Foundation of China (National Science Foundation of China)/ ; }, abstract = {Food safety of leafy greens is an emerging public health issue as they can harbor opportunistic human pathogens (OHPs) and expose OHPs to consumers. Protists are an integral part of phyllosphere microbial ecosystems. However, our understanding of protist-pathogen associations in the phyllosphere and their consequences on public health remains poor. Here, we examined phyllosphere protists, human pathogen marker genes (HPMGs), and protist endosymbionts from four species of leafy greens from major supermarkets in Xiamen, China. Our results showed that Staphylococcus aureus and Klebsiella pneumoniae were the dominant human pathogens in the vegetable phyllosphere. The distribution of HPMGs and protistan communities differed between vegetable species, of which Chinese chive possessed the most diverse protists and highest abundance of HPMGs. HPMGs abundance positively correlated with the diversity and relative abundance of phagotrophic protists. Whole genome sequencing further uncovered that most isolated phyllosphere protists harbored multiple OHPs which carried antibiotic resistance genes, virulence factors, and metal resistance genes and had the potential to HGT. Colpoda were identified as key phagotrophic protists which positively linked to OHPs and carried diverse resistance and virulence potential endosymbiont OHPs including Pseudomonas nitroreducens, Achromobacter xylosoxidans, and Stenotrophomonas maltophilia. We highlight that phyllosphere protists contribute to the transmission of resistant OHPs through internalization and thus pose risks to the food safety of leafy greens and human health. Our study provides insights into the protist-OHP interactions in the phyllosphere, which will help in food safety surveillance and human health.}, }
@article {pmid37658881, year = {2023}, author = {Owashi, Y and Minami, T and Kikuchi, T and Yoshida, A and Nakano, R and Kageyama, D and Adachi-Hagimori, T}, title = {Microbiome of Zoophytophagous Biological Control Agent Nesidiocoris tenuis.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {37658881}, issn = {1432-184X}, abstract = {Many insects are associated with endosymbionts that influence the feeding, reproduction, and distribution of their hosts. Although the small green mirid, Nesidiocoris tenuis (Reuter) (Hemiptera: Miridae), a zoophytophagous predator that feeds on plants as well as arthropods, is a globally important biological control agent, its microbiome has not been sufficiently studied. In the present study, we assessed the microbiome variation in 96 N. tenuis individuals from 14 locations throughout Japan, based on amplicon sequencing of the 16S ribosomal RNA gene. Nine major bacteria associated with N. tenuis were identified: Rickettsia, two strains of Wolbachia, Spiroplasma, Providencia, Serratia, Pseudochrobactrum, Lactococcus, and Stenotrophomonas. Additionally, a diagnostic PCR analysis for three typical insect reproductive manipulators, Rickettsia, Wolbachia, and Spiroplasma, was performed on a larger sample size (n = 360) of N. tenuis individuals; the most prevalent symbiont was Rickettsia (69.7%), followed by Wolbachia (39.2%) and Spiroplasma (6.1%). Although some symbionts were co-infected, their prevalence did not exhibit any specific tendency, such as a high frequency in specific infection combinations. The infection frequency of Rickettsia was significantly correlated with latitude and temperature, while that of Wolbachia and Spiroplasma was significantly correlated with host plants. The predominance of these bacteria and the absence of obligate symbionts suggested that the N. tenuis microbiome is typical for predatory arthropods rather than sap-feeding insects. Rickettsia and Wolbachia were vertically transmitted rather than horizontally transmitted from the prey. The functional validation of each symbiont would be warranted to develop N. tenuis as a biological control agent.}, }
@article {pmid37653429, year = {2023}, author = {Duong Thi Hue, K and da Silva Goncalves, D and Tran Thuy, V and Thi Vo, L and Le Thi, D and Vu Tuyet, N and Nguyen Thi, G and Huynh Thi Xuan, T and Nguyen Minh, N and Nguyen Thanh, P and Yacoub, S and Simmons, CP}, title = {Wolbachia wMel strain-mediated effects on dengue virus vertical transmission from Aedes aegypti to their offspring.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {308}, pmid = {37653429}, issn = {1756-3305}, abstract = {BACKGROUND: Dengue virus serotypes (DENV-1 to -4) can be transmitted vertically in Aedes aegpti mosquitoes. Whether infection with the wMel strain of the endosymbiont Wolbachia can reduce the incidence of vertical transmission of DENV from infected females to their offspring is not well understood.<br><br>METHODS: A laboratory colony of Vietnamese Ae. aegypti, both with and without wMel infection, were infected with DENV-1 by intrathoracic injection (IT) to estimate the rate of vertical transmission (VT) of the virus. VT in the DENV-infected mosquitoes was calculated via the infection rate estimation from mosquito pool data using maximum likelihood estimation (MLE).<br><br>RESULTS: In 6047 F1 Vietnamese wild-type Ae. aegypti, the MLE of DENV-1 infection was 1.49 per 1000 mosquitoes (95% confidence interval [CI] 0.73-2.74). In 5500&#xa0;wMel-infected Ae. aegypti, the MLE infection rate was 0 (95% CI 0-0.69). The VT rates between mosquito lines showed a statistically significant difference.<br><br>CONCLUSIONS: The results reinforce the view that VT is a rare event in wild-type mosquitoes and that infection with wMel is effective in reducing VT.}, }
@article {pmid37653056, year = {2023}, author = {Takahashi, K and Kuwahara, H and Horikawa, Y and Izawa, K and Kato, D and Inagaki, T and Yuki, M and Ohkuma, M and Hongoh, Y}, title = {Emergence of putative energy parasites within Clostridia revealed by genome analysis of a novel endosymbiotic clade.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {37653056}, issn = {1751-7370}, support = {17H01447//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 19H05689//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; GS009//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 22241046//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 16H04840//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 20H02897//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 20H05584//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 22K19342//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 14532219//MEXT | JST | Core Research for Evolutional Science and Technology (CREST)/ ; }, abstract = {The Clostridia is a dominant bacterial class in the guts of various animals and are considered to nutritionally contribute to the animal host. Here, we discovered clostridial endosymbionts of cellulolytic protists in termite guts, which have never been reported with evidence. We obtained (near-)complete genome sequences of three endosymbiotic Clostridia, each associated with a different parabasalid protist species with various infection rates: Trichonympha agilis, Pseudotrichonympha grassii, and Devescovina sp. All these protists are previously known to harbor permanently-associated, mutualistic Endomicrobia or Bacteroidales that supplement nitrogenous compounds. The genomes of the endosymbiotic Clostridia were small in size (1.0-1.3 Mbp) and exhibited signatures of an obligately-intracellular parasite, such as an extremely limited capability to synthesize amino acids, cofactors, and nucleotides and a disrupted glycolytic pathway with no known net ATP-generating system. Instead, the genomes encoded ATP/ADP translocase and, interestingly, regulatory proteins that are unique to eukaryotes in general and are possibly used to interfere with host cellular processes. These three genomes formed a clade with metagenome-assembled genomes (MAGs) derived from the guts of other animals, including human and ruminants, and the MAGs shared the characteristics of parasites. Gene flux analysis suggested that the acquisition of the ATP/ADP translocase gene in a common ancestor was probably key to the emergence of this parasitic clade. Taken together, we provide novel insights into the multilayered symbiotic system in the termite gut by adding the presence of parasitism and present an example of the emergence of putative energy parasites from a dominant gut bacterial clade.}, }
@article {pmid37650927, year = {2023}, author = {Ho, HVN and Dunigan, DD and Salsbery, ME and Agarkova, IV and Al Ameeli, Z and Van Etten, JL and DeLong, JP}, title = {Viral Chemotaxis of Paramecium Bursaria Altered by Algal Endosymbionts.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {37650927}, issn = {1432-184X}, support = {1736030//Directorate for Biological Sciences/ ; 1736030//Directorate for Biological Sciences/ ; 1736030//Directorate for Biological Sciences/ ; }, abstract = {Chemotaxis is widespread across many taxa and often aids resource acquisition or predator avoidance. Species interactions can modify the degree of movement facilitated by chemotaxis. In this study, we investigated the influence of symbionts on Paramecium bursaria's chemotactic behavior toward chloroviruses. To achieve this, we performed choice experiments using chlorovirus and control candidate attractors (virus stabilization buffer and pond water). We quantified the movement of Paramecia grown with or without algal and viral symbionts toward each attractor. All Paramecia showed some chemotaxis toward viruses, but cells without algae and viruses showed the most movement toward viruses. Thus, the endosymbiotic algae (zoochlorellae) appeared to alter the movement of Paramecia toward chloroviruses, but it was not clear that ectosymbiotic viruses (chlorovirus) also had this effect. The change in behavior was consistent with a change in swimming speed, but a change in attraction remains possible. The potential costs and benefits of chemotactic movement toward chloroviruses for either the Paramecia hosts or its symbionts remain unclear.}, }
@article {pmid37650335, year = {2023}, author = {Ehinger, F and Niehs, S and Dose, B and Dell, M and Krabe, J and Pidot, SJ and Stinear, TP and Scherlach, K and Ross, C and Lackner, G and Hertweck, C}, title = {Analysis of Rhizonin Biosynthesis Reveals Origin of Pharmacophoric Furylalanine Moieties in Diverse Cyclopeptides.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {}, number = {}, pages = {e202308540}, doi = {10.1002/anie.202308540}, pmid = {37650335}, issn = {1521-3773}, abstract = {Rhizonin A and B are hepatotoxic cyclopeptides produced by bacterial endosymbionts (Mycetohabitans endofungorum) of the fungus Rhizopus microsporus. Their toxicity critically depends on the presence of 3-furylalanine (Fua) residues, which also occur in pharmaceutically relevant cyclopeptides of the endolide and bingchamide families. The biosynthesis and incorporation of Fua by non-ribosomal peptide synthetases (NRPS), however, has remained elusive. By genome sequencing and gene inactivation we elucidated the gene cluster responsible for rhizonin biosynthesis. A suite of isotope labeling experiments identified tyrosine and l-DOPA as Fua precursors and provided the first mechanistic insights. Bioinformatics, mutational analysis and heterologous reconstitution identified dioxygenase RhzB as necessary and sufficient for Fua formation. RhzB is a novel type of heme-dependent aromatic oxygenases (HDAO) that enabled the discovery of the bingchamide biosynthesis gene cluster through genome mining.}, }
@article {pmid37645949, year = {2023}, author = {Wenzel, M and Aquadro, CF}, title = {Wolbachia infection at least partially rescues the fertility and ovary defects of several new Drosophila melanogaster bag of marbles protein-coding mutants.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.20.532813}, pmid = {37645949}, abstract = {UNLABELLED: The D. melanogaster protein coding gene bag of marbles (bam) plays a key role in early male and female reproduction by forming complexes with partner proteins to promote differentiation in gametogenesis. Like another germline gene, Sex lethal , bam genetically interacts with the endosymbiont Wolbachia , as Wolbachia rescues the reduced fertility of a bam hypomorphic mutant. Here, we explored the specificity of the bam-Wolbachia interaction by generating 22 new bam mutants, with ten mutants displaying fertility defects. Nine of these mutants trend towards rescue by the w Mel Wolbachia variant, with eight statistically significant at the fertility and/or cytological level. In some cases, fertility was increased a striking 20-fold. There is no specificity between the rescue and the known binding regions of bam , suggesting w Mel does not interact with one singular bam partner to rescue the reproductive phenotype. We further tested if w Mel interacts with bam in a non-specific way, by increasing bam transcript levels or acting upstream in germline stem cells. A fertility assessment of a bam RNAi knockdown mutant reveals that w Mel rescue is specific to functionally mutant bam alleles and we find no obvious evidence of w Mel interaction with germline stem cells in bam mutants.<br><br>AUTHOR SUMMARY: Reproduction in the Drosophila melanogaster fruit fly is dependent on the bag of marbles (bam) gene, which acts early in the process of generating eggs and sperm. Mutations to this gene negatively impact the fertility of the fly, causing it to be sterile or have fewer progeny. Interestingly, we find that the bacteria Wolbachia , which resides within reproductive cells across a wide range of insects, partially restores the fertility and ovary phenotype of several bam mutants of which the resultant Bam protein is altered from wildtype. The protein function of Bam is further suggested to be important by the lack of rescue for a fly that has a fertility defect due to low expression of a non-mutated bam gene. Previous work makes similar conclusions about Wolbachia with another reproductive gene, Sex lethal (Sxl), highlighting the potential for rescue of fertility mutants to occur in a similar way across different genes. An understanding of the ways in which Wolbachia can affect host reproduction provides us with context with which to frame Wolbachia 's impact on host genes, such as bam and Sxl, and consider the evolutionary implications of Wolbachia 's infection in D. melanogaster fruit flies.}, }
@article {pmid37638258, year = {2023}, author = {Sheibani, P and Jamshidi, M and Khakvar, R and Nematollahi, S}, title = {Genomic Characterization of Endosymbiotic Bacteria Associated With Helicoverpa armigera in Iran Using Next-Generation Sequencing.}, journal = {Bioinformatics and biology insights}, volume = {17}, number = {}, pages = {11779322231195457}, pmid = {37638258}, issn = {1177-9322}, abstract = {Several species of the Helicoverpa genus have been recognized as major agricultural pests from different regions of the world, among which Helicoverpa armigera species has been reported as the most destructive and cosmopolitan species in most regions of the world, including Iran. This pest is a polyphagous species and can cause damage to more than 120 plant species. Studying the internal microbiome of pests is very important in identifying species' weaknesses and natural enemies and potential biological control agents. For genomic characterization of the microbial community associated with H armigera, the whole genome of insect larvae collected from vegetable fields in the northwest of Iran was sequenced using next-generation sequencing Illumina platform. Finally, about 2 GB of raw data were obtained. Using the MetaPhlAn2 pipeline, it was predicted that 2 endosymbiont bacterial species including Buchnera aphidicola and Serratia symbiotica were associated with H armigera. Alignment of reference strains sequences related to both endosymbiotic bacteria with raw data and subsequently, assembly analyses resulted in 2 genomes with 657 623 bp length with GC content of 27.4% for B aphidicola and 1 595 135 bp length with GC content of 42.90% for S symbiotica. This research is the first report on the association of B aphidicola and S symbiotica as endosymbiotic bacteria with H armigera worldwide.}, }
@article {pmid37634049, year = {2023}, author = {Treitli, SC and Hanousková, P and Beneš, V and Brune, A and Čepička, I and Hampl, V}, title = {Hydrogenotrophic methanogenesis is the key process in the obligately syntrophic consortium of the anaerobic ameba Pelomyxa schiedti.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {37634049}, issn = {1751-7370}, abstract = {Pelomyxa is a genus of anaerobic amoebae that live in consortia with multiple prokaryotic endosymbionts. Although the symbionts represent a large fraction of the cellular biomass, their metabolic roles have not been investigated. Using single-cell genomics and transcriptomics, we have characterized the prokaryotic community associated with P. schiedti, which is composed of two bacteria, Candidatus Syntrophus pelomyxae (class Deltaproteobacteria) and Candidatus Vesiculincola pelomyxae (class Clostridia), and a methanogen, Candidatus Methanoregula pelomyxae. Fluorescence in situ hybridization and electron microscopy showed that Ca. Vesiculincola pelomyxae is localized inside vesicles, whereas the other endosymbionts occur freely in the cytosol, with Ca. Methanoregula pelomyxae enriched around the nucleus. Genome and transcriptome-based reconstructions of the metabolism suggests that the cellulolytic activity of P. schiedti produces simple sugars that fuel its own metabolism and the metabolism of a Ca. Vesiculincola pelomyxae, while Ca. Syntrophus pelomyxae energy metabolism relies on degradation of butyrate and isovalerate from the environment. Both species of bacteria and the ameba use hydrogenases to transfer the electrons from reduced equivalents to hydrogen, a process that requires a low hydrogen partial pressure. This is achieved by the third endosymbiont, Ca. Methanoregula pelomyxae, which consumes H2 and formate for methanogenesis. While the bacterial symbionts can be successfully eliminated by vancomycin treatment without affecting the viability of the amoebae, treatment with 2-bromoethanesulfonate, a specific inhibitor of methanogenesis, killed the amoebae, indicating the essentiality of the methanogenesis for this consortium.}, }
@article {pmid37630596, year = {2023}, author = {Mancuso, E and Di Domenico, M and Di Gialleonardo, L and Menegon, M and Toma, L and Di Luca, M and Casale, F and Di Donato, G and D'Onofrio, L and De Rosa, A and Riello, S and Ferri, A and Serra, L and Monaco, F}, title = {Tick Species Diversity and Molecular Identification of Spotted Fever Group Rickettsiae Collected from Migratory Birds Arriving from Africa.}, journal = {Microorganisms}, volume = {11}, number = {8}, pages = {}, pmid = {37630596}, issn = {2076-2607}, support = {IZS AM 04/19 RC//Italian Ministry of Health/ ; }, abstract = {The role of migratory birds in the spread of ticks and tick-borne pathogens along their routes from Africa to Europe is increasingly emerging. Wild birds can host several tick species, often infected by bacteria responsible for zoonoses. The aim of the study is to assess the possible introduction of exotic ticks carried by migratory birds into Italy from Africa and to detect the presence of Rickettsia species and Coxiella burnetii they may harbor. During a two-year survey, we collected ticks from migratory birds captured during their short stop-over on Ventotene Island. Specimens were first identified by morphology or sequencing molecular targets when needed, and then tested by real-time PCR for the presence of selected pathogens. A total of 91% of the collection consisted of sub-Saharan ticks, more than 50% of which were infected by Rickettsia species belonging to the spotted fever group, mainly represented by R. aeschlimannii. In contrast, the suspected C. burnetii detected in two soft ticks were confirmed as Coxiella-like endosymbionts and not the pathogen. Although there are still gaps in the knowledge of this dispersal process, our findings confirm the role of migratory birds in the spread of ticks and tick-borne pathogens, suggesting the need for a continuous surveillance to monitor the potential emergence of new diseases in Europe.}, }
@article {pmid37630527, year = {2023}, author = {Namina, A and Kazarina, A and Lazovska, M and Akopjana, S and Ulanova, V and Kivrane, A and Freimane, L and Sadovska, D and Kimsis, J and Bormane, A and Capligina, V and Ranka, R}, title = {Comparative Microbiome Analysis of Three Epidemiologically Important Tick Species in Latvia.}, journal = {Microorganisms}, volume = {11}, number = {8}, pages = {}, doi = {10.3390/microorganisms11081970}, pmid = {37630527}, issn = {2076-2607}, support = {No. 1.1.1.1/16/A/044//European Research and Development Fund/ ; }, abstract = {(1) Background: Amplicon-based 16S rRNA profiling is widely used to study whole communities of prokaryotes in many niches. Here, we comparatively examined the microbial composition of three tick species, Ixodes ricinus, Ixodes persulcatus and Dermacentor reticulatus, which were field-collected in Latvia. (2) Methods: Tick DNA samples were used for microbiome analysis targeting bacterial 16S rDNA using next-generation sequencing (NGS). (3) Results: The results showed significant differences in microbial species diversity and composition by tick species and life stage. A close similarity between microbiomes of I. ricinus and I. persulcatus ticks was observed, while the D. reticulatus microbiome composition appeared to be more distinct. Significant differences in alpha and beta microbial diversity were observed between Ixodes tick life stages and sexes, with lower taxa richness indexes obtained for female ticks. The Francisella genus was closely associated with D. reticulatus ticks, while endosymbionts Candidatus Midichlorii and Candidatus Lariskella were associated with I. ricinus and I. persulcatus females, respectively. In I. ricinus females, the endosymbiont load negatively correlated with the presence of the Rickettsia genus. (4) Conclusions: The results of this study revealed important associations between ticks and their microbial community and highlighted the microbiome features of three tick species in Latvia.}, }
@article {pmid37630471, year = {2023}, author = {Chao, LL and Shih, CM}, title = {First Detection and Genetic Identification of Wolbachia Endosymbiont in Field-Caught Aedes aegypti (Diptera: Culicidae) Mosquitoes Collected from Southern Taiwan.}, journal = {Microorganisms}, volume = {11}, number = {8}, pages = {}, doi = {10.3390/microorganisms11081911}, pmid = {37630471}, issn = {2076-2607}, support = {MOST 111-2314-B-037-031//Ministry of Science and Technology, Taiwan/ ; }, abstract = {The prevalence and genetic character of Wolbachia endosymbionts in field-collected Aedes aegypti mosquitoes were examined for the first time in Taiwan. A total of 665 Ae. aegypti were screened for Wolbachia infection using a PCR assay targeting the Wolbachia surface protein (wsp) gene. In general, the prevalence of Wolbachia infection was detected in 3.3% Ae. aegypti specimens (2.0% female and 5.2% male). Group-specific Wolbachia infection was detected with an infection rate of 1.8%, 0.8% and 0.8% in groups A, B and A&amp;B, respectively. Genetic analysis demonstrated that all Wolbachia strains from Taiwan were phylogenetically affiliated with Wolbachia belonging to the supergroups A and B, with high sequence similarities of 99.4-100% and 99.2-100%, respectively. Phylogenetic relationships can be easily distinguished by maximum likelihood (ML) analysis and were congruent with the unweighted pair group with the arithmetic mean (UPGMA) method. The intra- and inter-group analysis of genetic distance (GD) values revealed a lower level within the Taiwan strains (GD < 0.006 for group A and GD < 0.008 for group B) and a higher level (GD > 0.498 for group A and GD > 0.286 for group B) as compared with other Wolbachia strains. Our results describe the first detection and molecular identification of Wolbachia endosymbiont in field-caught Ae. aegypti mosquitoes collected from Taiwan, and showed a low Wolbachia infection rate belonging to supergroups A and B in Ae. aegypti mosquitoes.}, }
@article {pmid37628597, year = {2023}, author = {Corpuz, RL and Bellinger, MR and Veillet, A and Magnacca, KN and Price, DK}, title = {The Transmission Patterns of the Endosymbiont Wolbachia within the Hawaiian Drosophilidae Adaptive Radiation.}, journal = {Genes}, volume = {14}, number = {8}, pages = {}, doi = {10.3390/genes14081545}, pmid = {37628597}, issn = {2073-4425}, support = {1345247//National Science Foundation/ ; }, abstract = {The evolution of endosymbionts and their hosts can lead to highly dynamic interactions with varying fitness effects for both the endosymbiont and host species. Wolbachia, a ubiquitous endosymbiont of arthropods and nematodes, can have both beneficial and detrimental effects on host fitness. We documented the occurrence and patterns of transmission of Wolbachia within the Hawaiian Drosophilidae and examined the potential contributions of Wolbachia to the rapid diversification of their hosts. Screens for Wolbachia infections across a minimum of 140 species of Hawaiian Drosophila and Scaptomyza revealed species-level infections of 20.0%, and across all 399 samples, a general infection rate of 10.3%. Among the 44 Wolbachia strains we identified using a modified Wolbachia multi-locus strain typing scheme, 30 (68.18%) belonged to supergroup B, five (11.36%) belonged to supergroup A, and nine (20.45%) had alleles with conflicting supergroup assignments. Co-phylogenetic reconciliation analysis indicated that Wolbachia strain diversity within their endemic Hawaiian Drosophilidae hosts can be explained by vertical (e.g., co-speciation) and horizontal (e.g., host switch) modes of transmission. Results from stochastic character trait mapping suggest that horizontal transmission is associated with the preferred oviposition substrate of the host, but not the host's plant family or island of occurrence. For Hawaiian Drosophilid species of conservation concern, with 13 species listed as endangered and 1 listed as threatened, knowledge of Wolbachia strain types, infection status, and potential for superinfection could assist with conservation breeding programs designed to bolster population sizes, especially when wild populations are supplemented with laboratory-reared, translocated individuals. Future research aimed at improving the understanding of the mechanisms of Wolbachia transmission in nature, their impact on the host, and their role in host species formation may shed light on the influence of Wolbachia as an evolutionary driver, especially in Hawaiian ecosystems.}, }
@article {pmid37623315, year = {2023}, author = {Moriyama, M and Nishide, Y and Toyoda, A and Itoh, T and Fukatsu, T}, title = {Complete genomes of mutualistic bacterial co-symbionts "Candidatus Sulcia muelleri" and "Candidatus Nasuia deltocephalinicola" of the rice green leafhopper Nephotettix cincticeps.}, journal = {Microbiology resource announcements}, volume = {}, number = {}, pages = {e0035323}, doi = {10.1128/MRA.00353-23}, pmid = {37623315}, issn = {2576-098X}, abstract = {The genomes of obligate bacterial co-symbionts of the green rice leafhopper Nephotettix cincticeps, which is notorious as an agricultural pest, were determined. The streamlined genomes of "Candidatus Sulcia muelleri" and "Candidatus Nasuia deltocephalinicola" exhibited complementary metabolic pathways for synthesizing essential nutrients that contribute to host adaptation.}, }
@article {pmid37622600, year = {2023}, author = {Ciocchetta, S and Frentiu, FD and Montarsi, F and Capelli, G and Devine, GJ}, title = {Investigation on key aspects of mating biology in the mosquito Aedes koreicus.}, journal = {Medical and veterinary entomology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mve.12687}, pmid = {37622600}, issn = {1365-2915}, abstract = {Aedes koreicus Edwards, 1917 (Hulecoetomyia koreica) is a mosquito (Diptera: Culicidae) from Northeast Asia with a rapidly expanding presence outside its original native range. Over the years, the species has been discovered in several new countries, either spreading after first introduction or remaining localised to limited areas. Notably, recent studies have demonstrated the ability of the species to transmit zoonotic parasites and viruses both in the field and in laboratory settings. Combined with its invasive potential, the possible role of Ae. koreicus in pathogen transmission highlights the public health risks resulting from its invasion. In this study, we used a recently established population from Italy to investigate aspects of biology that influence reproductive success in Ae. koreicus: autogeny, mating behaviour, mating disruption by the sympatric invasive species Aedes albopictus Skuse, 1894, and the presence of the endosymbiont Wolbachia pipientis Hertig, 1936. Our laboratory population did not exhibit autogenic behaviour and required a bloodmeal to complete its ovarian cycle. When we exposed Ae. koreicus females to males of Ae. albopictus, we observed repeated attempts at insemination and an aggressive, disruptive mating behaviour initiated by male Ae. albopictus. Despite this, no sperm was identified in Ae. koreicus spermathecae. Wolbachia, an endosymbiotic bacterium capable of influencing mosquito reproductive behaviour, was not detected in this Ae. koreicus population and, therefore, had no effect on Ae. koreicus reproduction.}, }
@article {pmid37615902, year = {2023}, author = {Lanzoni, O and Szokoli, F and Schrallhammer, M and Sabaneyeva, E and Krenek, S and Doak, TG and Verni, F and Berendonk, TU and Castelli, M and Petroni, G}, title = {"Candidatus Intestinibacterium parameciiphilum"-member of the "Candidatus Paracaedibacteraceae" family (Alphaproteobacteria, Holosporales) inhabiting the ciliated protist Paramecium.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {37615902}, issn = {1618-1905}, abstract = {Protists frequently host diverse bacterial symbionts, in particular those affiliated with the order Holosporales (Alphaproteobacteria). All characterised members of this bacterial lineage have been retrieved in obligate association with a wide range of eukaryotes, especially multiple protist lineages (e.g. amoebozoans, ciliates, cercozoans, euglenids, and nucleariids), as well as some metazoans (especially arthropods and related ecdysozoans). While the genus Paramecium and other ciliates have been deeply investigated for the presence of symbionts, known members of the family "Candidatus Paracaedibacteraceae" (Holosporales) are currently underrepresented in such hosts. Herein, we report the description of "Candidatus Intestinibacterium parameciiphilum" within the family "Candidatus Paracaedibacteraceae", inhabiting the cytoplasm of Paramecium biaurelia. This novel bacterium is almost twice as big as its relative "Candidatus Intestinibacterium nucleariae" from the opisthokont Nuclearia and does not present a surrounding halo. Based on phylogenetic analyses of 16S rRNA gene sequences, we identified six further potential species-level lineages within the genus. Based on the provenance of the respective samples, we investigated the environmental distribution of the representatives of "Candidatus Intestinibacterium" species. Obtained results are consistent with an obligate endosymbiotic lifestyle, with protists, in particular freshwater ones, as hosts. Thus, available data suggest that association with freshwater protists could be the ancestral condition for the members of the "Candidatus Intestinibacterium" genus.}, }
@article {pmid37601442, year = {2023}, author = {Archer, J and Hurst, GDD and Hornett, EA}, title = {Male-killer symbiont screening reveals novel associations in Adalia ladybirds.}, journal = {Access microbiology}, volume = {5}, number = {7}, pages = {}, pmid = {37601442}, issn = {2516-8290}, abstract = {While male-killing bacteria are known to infect across arthropods, ladybird beetles represent a hotspot for these symbioses. In some host species, there are multiple different symbionts that vary in presence and frequency between populations. To further our understanding of spatial and frequency variation, we tested for the presence of three male-killing bacteria: Wolbachia , Rickettsia and Spiroplasma , in two Adalia ladybird species from a previously unexplored UK population. The two-spot ladybird, A. bipunctata, is known to harbour all three male-killers, and we identified Spiroplasma infection in the Merseyside population for the first time. However, in contrast to previous studies on two-spot ladybirds from continental Europe, evidence from egg-hatch rates indicates the Spiroplasma strain present in the Merseyside population does not cause embryonic male-killing. In the related ten-spot ladybird, A. decempunctata, there is only one previous record of a male-killing symbiont, a Rickettsia , which we did not detect in the Merseyside sample. However, PCR assays indicated the presence of a Spiroplasma in a single A. decempunctata specimen. Marker sequence indicated that this Spiroplasma was divergent from that found in sympatric A. bipunctata. Genome sequencing of the Spiroplasma -infected A. decempunctata additionally revealed the presence of cobionts in the form of a Centistes parasitoid wasp and the parasitic fungi Beauveria. Further study of A. decempunctata from this population is needed to resolve whether it is the ladybird or wasp cobiont that harbours Spiroplasma , and to establish the phenotype of this strain. These data indicate first that microbial symbiont phenotype should not be assumed from past studies conducted in different locations, and second that cobiont presence may confound screening studies aimed to detect the frequency of a symbiont in field collected material from a focal host species.}, }
@article {pmid37593719, year = {2023}, author = {Scott, TJ and Larsen, TJ and Brock, DA and Uhm, SYS and Queller, DC and Strassmann, JE}, title = {Symbiotic bacteria, immune-like sentinel cells, and the response to pathogens in a social amoeba.}, journal = {Royal Society open science}, volume = {10}, number = {8}, pages = {230727}, pmid = {37593719}, issn = {2054-5703}, abstract = {Some endosymbionts living within a host must modulate their hosts' immune systems in order to infect and persist. We studied the effect of a bacterial endosymbiont on a facultatively multicellular social amoeba host. Aggregates of the amoeba Dictyostelium discoideum contain a subpopulation of sentinel cells that function akin to the immune systems of more conventional multicellular organisms. Sentinel cells sequester and discard toxins from D. discoideum aggregates and may play a central role in defence against pathogens. We measured the number and functionality of sentinel cells in aggregates of D. discoideum infected by bacterial endosymbionts in the genus Paraburkholderia. Infected D. discoideum produced fewer and less functional sentinel cells, suggesting that Paraburkholderia may interfere with its host's immune system. Despite impaired sentinel cells, however, infected D. discoideum were less sensitive to ethidium bromide toxicity, suggesting that Paraburkholderia may also have a protective effect on its host. By contrast, D. discoideum infected by Paraburkholderia did not show differences in their sensitivity to two non-symbiotic pathogens. Our results expand previous work on yet another aspect of the complicated relationship between D. discoideum and Paraburkholderia, which has considerable potential as a model for the study of symbiosis.}, }
@article {pmid37399133, year = {2023}, author = {Beliavskaia, A and Tan, KK and Sinha, A and Husin, NA and Lim, FS and Loong, SK and Bell-Sakyi, L and Carlow, CKS and AbuBakar, S and Darby, AC and Makepeace, BL and Khoo, JJ}, title = {Metagenomics of culture isolates and insect tissue illuminate the evolution of Wolbachia, Rickettsia and Bartonella symbionts in Ctenocephalides spp. fleas.}, journal = {Microbial genomics}, volume = {9}, number = {7}, pages = {}, pmid = {37399133}, issn = {2057-5858}, support = {BB/P024378/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/P024270/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 223743/Z/21/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Rickettsia/genetics ; *Bartonella/genetics ; *Siphonaptera/microbiology ; *Ctenocephalides/microbiology ; *Wolbachia/genetics ; Metagenomics ; Insecta ; }, abstract = {While fleas are often perceived simply as a biting nuisance and a cause of allergic dermatitis, they represent important disease vectors worldwide, especially for bacterial zoonoses such as plague (transmitted by rodent fleas) and some of the rickettsioses and bartonelloses. The cosmopolitan cat (Ctenocephalides felis) and dog (Ctenocephalides canis) fleas, as well as Ctenocephalides orientis (restricted to tropical and subtropical Asia), breed in human dwellings and are vectors of cat-scratch fever (caused by Bartonella spp.) and Rickettsia spp., including Rickettsia felis (agent of flea-borne spotted fever) and Rickettsia asembonensis , a suspected pathogen. These Rickettsia spp. are members of a phylogenetic clade known as the ‘transitional group’, which includes both human pathogens and arthropod-specific endosymbionts. The relatively depauperate flea microbiome can also contain other endosymbionts, including a diverse range of Wolbachia strains. Here, we present circularized genome assemblies for two C. orientis-derived pathogens (Bartonella clarridgeiae and R. asembonensis) from Malaysia, a novel Wolbachia strain (wCori), and the C. orientis mitochondrion; all were obtained by direct metagenomic sequencing of flea tissues. Moreover, we isolated two Wolbachia strains from Malaysian C. felis into tick cell culture and recovered circularized genome assemblies for both, one of which (wCfeF) is newly sequenced. We demonstrate that the three Wolbachia strains are representatives of different major clades (‘supergroups’), two of which appear to be flea-specific. These Wolbachia genomes exhibit unique combinations of features associated with reproductive parasitism or mutualism, including prophage WO, cytoplasmic incompatibility factors and the biotin operon of obligate intracellular microbes. The first circularized assembly for R. asembonensis includes a plasmid with a markedly different structure and gene content compared to the published plasmid; moreover, this novel plasmid was also detected in cat flea metagenomes from the USA. Analysis of loci under positive selection in the transitional group revealed genes involved in host–pathogen interactions that may facilitate host switching. Finally, the first B. clarridgeiae genome from Asia exhibited large-scale genome stability compared to isolates from other continents, except for SNPs in regions predicted to mediate interactions with the vertebrate host. These findings highlight the paucity of data on the genomic diversity of Ctenocephalides-associated bacteria and raise questions regarding how interactions between members of the flea microbiome might influence vector competence.}, }
@article {pmid37585608, year = {2023}, author = {Shao, Y and Mason, CJ and Felton, GW}, title = {Toward an Integrated Understanding of the Lepidoptera Microbiome.}, journal = {Annual review of entomology}, volume = {}, number = {}, pages = {}, doi = {10.1146/annurev-ento-020723-102548}, pmid = {37585608}, issn = {1545-4487}, abstract = {Research over the past 30 years has led to a widespread acceptance that insects establish widespread and diverse associations with microorganisms. More recently, microbiome research has been accelerating in lepidopteran systems, leading to a greater understanding of both endosymbiont and gut microorganisms and how they contribute to integral aspects of the host. Lepidoptera are associated with a robust assemblage of microorganisms, some of which may be stable and routinely detected in larval and adult hosts, while others are ephemeral and transient. Certain microorganisms that populate Lepidoptera can contribute significantly to the hosts' performance and fitness, while others are inconsequential. We emphasize the context-dependent nature of the interactions between players. While our review discusses the contemporary literature, there are major avenues yet to be explored to determine both the fundamental aspects of host-microbe interactions and potential applications for the lepidopteran microbiome; we describe these avenues after our synthesis. Expected final online publication date for the Annual Review of Entomology, Volume 69 is January 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.}, }
@article {pmid37584011, year = {2023}, author = {Perles, L and Otranto, D and Barreto, WTG and de Macedo, GC and Lia, RP and Mendoza-Roldan, JA and Herrera, HM and de Oliveira, CE and Machado, RZ and André, MR}, title = {Mansonella sp. and associated Wolbachia endosymbionts in ring-tailed coatis (Nasua nasua) in periurban areas from Midwestern Brazil.}, journal = {International journal for parasitology. Parasites and wildlife}, volume = {22}, number = {}, pages = {14-19}, pmid = {37584011}, issn = {2213-2244}, abstract = {Coatis (Nasua nasua) are wild carnivorous well adapted to anthropized environments especially important because they act as reservoirs hosts for many arthropod-borne zoonotic pathogens. Information about filarioids from coatis and associated Wolbachia spp. in Brazil is scant. To investigate the diversity of filarial nematodes, blood samples (n = 100 animals) were obtained from two urban areas in midwestern Brazil and analyzed using blood smears and buffy coats and cPCR assays based on the cox1, 12S rRNA, 18S rRNA, hsp70 and myoHC genes for nematodes and 16S rRNA for Wolbachia. When analyzing coati blood smears and buffy coats, 30% and 80% of the samples presented at least one microfilaria, respectively. Twenty-five cox1 sequences were obtained showing 89% nucleotide identity with Mansonella ozzardi. Phylogenetic analyses clustered cox1 sequences herein obtained within the Mansonella spp. clade. Sequences of both myoHC and two hsp70 genes showed 99.8% nucleotide identity with Mansonella sp. and clustered into a clade within Mansonella sp., previously detected in coatis from Brazil. Two blood samples were positive for Wolbachia, with a 99% nucleotide identity with Wolbachia previously found in Mansonella perstans, Mansonella ozzardi and Mansonella atelensis and in ectoparasites of the genus Pseudolynchia, Melophagus and Cimex. The study showed a high prevalence of Mansonella sp. in the coati population examined, suggesting that this animal species play a role as reservoirs of a novel, yet to be described, species within the Onchocercidae family.}, }
@article {pmid37583325, year = {2023}, author = {Travers-Cook, TJ and Jokela, J and Buser, CC}, title = {The evolutionary ecology of fungal killer phenotypes.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2005}, pages = {20231108}, doi = {10.1098/rspb.2023.1108}, pmid = {37583325}, issn = {1471-2954}, abstract = {Ecological interactions influence evolutionary dynamics by selecting upon fitness variation within species. Antagonistic interactions often promote genetic and species diversity, despite the inherently suppressive effect they can have on the species experiencing them. A central aim of evolutionary ecology is to understand how diversity is maintained in systems experiencing antagonism. In this review, we address how certain single-celled and dimorphic fungi have evolved allelopathic killer phenotypes that engage in antagonistic interactions. We discuss the evolutionary pathways to the production of lethal toxins, the functions of killer phenotypes and the consequences of competition for toxin producers, their competitors and toxin-encoding endosymbionts. Killer phenotypes are powerful models because many appear to have evolved independently, enabling across-phylogeny comparisons of the origins, functions and consequences of allelopathic antagonism. Killer phenotypes can eliminate host competitors and influence evolutionary dynamics, yet the evolutionary ecology of killer phenotypes remains largely unknown. We discuss what is known and what remains to be ascertained about killer phenotype ecology and evolution, while bringing their model system properties to the reader's attention.}, }
@article {pmid37577638, year = {2023}, author = {He, LS and Qi, Y and Allard, CA and Valencia-Montoya, WA and Krueger, SP and Weir, K and Seminara, A and Bellono, NW}, title = {Molecular tuning of sea anemone stinging.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.06.15.545144}, pmid = {37577638}, abstract = {Jellyfish and sea anemones fire single-use, venom-covered barbs to immobilize prey or predators. We previously showed that the anemone Nematostella vectensis uses a specialized voltage-gated calcium (Ca V) channel to trigger stinging in response to synergistic prey-derived chemicals and touch (Weir et al., 2020). Here we use experiments and theory to find that stinging behavior is suited to distinct ecological niches. We find that the burrowing anemone Nematostella uses uniquely strong Ca V inactivation for precise control of predatory stinging. In contrast, the related anemone Exaiptasia diaphana inhabits exposed environments to support photosynthetic endosymbionts. Consistent with its niche, Exaiptasia indiscriminately stings for defense and expresses a Ca V splice variant that confers weak inactivation. Chimeric analyses reveal that Ca V β subunit adaptations regulate inactivation, suggesting an evolutionary tuning mechanism for stinging behavior. These findings demonstrate how functional specialization of ion channel structure contributes to distinct organismal behavior.}, }
@article {pmid37577446, year = {2023}, author = {Ali, A and Obaid, MK and Almutairi, MM and Alouffi, A and Numan, M and Ullah, S and Rehman, G and Islam, ZU and Khan, SB and Tanaka, T}, title = {Molecular detection of Coxiella spp. in ticks (Ixodidae and Argasidae) infesting domestic and wild animals: with notes on the epidemiology of tick-borne Coxiella burnetii in Asia.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1229950}, pmid = {37577446}, issn = {1664-302X}, abstract = {Tick-borne Coxiella spp. are emerging in novel regions infecting different hosts, but information regarding their occurrence is limited. The purpose of this study was the molecular screening of Coxiella spp. in various ticks infesting goats, sheep, camels, cattle, wild mice, and domestic fowls (Gallus gallus domesticus) in various districts of Khyber Pakhtunkhwa, Pakistan. Morphologically identified tick species were confirmed by obtaining their cox1 sequences and were molecularly screened for Coxiella spp. by sequencing GroEL fragments. Almost 345 out of 678 (50.9%) hosts were infested by nine tick species. Regarding the age groups, the hosts having an age >3 years were highly infested (192/345, 55.6%), while gender-wise infestation was higher in female hosts (237/345, 68.7%). In collected ticks, the nymphs were outnumbered (613/1,119, 54.8%), followed by adult females (293/1,119, 26.2%) and males (213/1,119, 19.7%). A total of 227 ticks were processed for molecular identification and detection of Coxiella spp. The obtained cox1 sequences of nine tick species such as Hyalomma dromedarii, Hyalomma anatolicum, Haemaphysalis cornupunctata, Haemaphysalis bispinosa, Haemaphysalis danieli, Haemaphysalis montgomeryi, Rhipicephalus haemaphysaloides, Rhipicephalus microplus, and Argas persicus showed maximum identities between 99.6% and 100% with the same species and in the phylogenetic tree, clustered to the corresponding species. All the tick species except Ha. danieli and R. microplus were found positive for Coxiella spp. (40/227, 17.6%), including Coxiella burnetii (15/40, 6.7%), Coxiella endosymbionts (14/40, 6.3%), and different Coxiella spp. (11/40, 4.9%). By the BLAST results, the GroEL fragments of Coxiella spp. showed maximum identity to C. burnetii, Coxiella endosymbionts, and Coxiella sp., and phylogenetically clustered to the corresponding species. This is the first comprehensive report regarding the genetic characterization of Coxiella spp. in Pakistan's ticks infesting domestic and wild hosts. Proper surveillance and management measures should be undertaken to avoid health risks.}, }
@article {pmid37577425, year = {2023}, author = {Garrido, M and Veiga, J and Garrigós, M and Martínez-de la Puente, J}, title = {The interplay between vector microbial community and pathogen transmission on the invasive Asian tiger mosquito, Aedes albopictus: current knowledge and future directions.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1208633}, pmid = {37577425}, issn = {1664-302X}, abstract = {The invasive Asian tiger mosquito Aedes albopictus is nowadays broadly distributed with established populations in all continents except Antarctica. In the invaded areas, this species represents an important nuisance for humans and, more relevant, it is involved in the local transmission of pathogens relevant under a public health perspective. Aedes albopictus is a competent vector of parasites such as Dirofilaria and viruses including dengue virus, Zika virus, and chikungunya virus, among others. The mosquito microbiota has been identified as one of the major drivers of vector competence, acting upon relevant vector functions as development or immunity. Here, we review the available literature on the interaction between Ae. albopictus microbiota and pathogen transmission and identify the knowledge gaps on the topic. Most studies are strictly focused on the interplay between pathogens and Wolbachia endosymbiont while studies screening whole microbiota are still scarce but increasing in recent years, supported on Next-generation sequencing tools. Most experimental trials use lab-reared mosquitoes or cell lines, exploring the molecular mechanisms of the microbiota-pathogen interaction. Yet, correlational studies on wild populations are underrepresented. Consequently, we still lack sufficient evidence to reveal whether the microbiota of introduced populations of Ae. albopictus differ from those of native populations, or how microbiota is shaped by different environmental and anthropic factors, but especially, how these changes affect the ability of Ae. albopictus to transmit pathogens and favor the occurrence of outbreaks in the colonized areas. Finally, we propose future research directions on this research topic.}, }
@article {pmid37573143, year = {2023}, author = {Pacheco, PJ and Cabrera, JJ and Jiménez-Leiva, A and Torres, MJ and Gates, AJ and Bedmar, EJ and Richardson, DJ and Mesa, S and Tortosa, G and Delgado, MJ}, title = {The copper-responsive regulator CsoR is indirectly involved in Bradyrhizobium diazoefficiens denitrification.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnad084}, pmid = {37573143}, issn = {1574-6968}, abstract = {The soybean endosymbiont Bradyrhizobium diazoefficiens harbours the complete denitrification pathway that is catalysed by a periplasmic nitrate reductase (Nap), a copper (Cu)-containing nitrite reductase (NirK), a c-type nitric oxide reductase (cNor), and a nitrous oxide reductase (Nos), encoded by the napEDABC, nirK, norCBQD and nosRZDFYLX genes, respectively. Induction of denitrification genes requires low oxygen and nitric oxide, both signals integrated into a complex regulatory network comprised by two interconnected cascades, FixLJ-FixK2-NnrR and RegSR-NifA. Copper is a cofactor of NirK and Nos, but it has also a role in denitrification gene expression and protein synthesis. In fact, Cu limitation triggers a substantial down-regulation of nirK, norCBQD, and nosRZDFYLX gene expression under denitrifying conditions. B. diazoefficiens genome possesses a gene predicted to encode a Cu-responsive repressor of the CsoR family, which is located adjacent to copA, a gene encoding a putative Cu+-ATPase transporter. To investigate the role of CsoR in the control of denitrification gene expression in response to Cu, a csoR deletion mutant was constructed in this work. Mutation of csoR did not affect the capacity of B. diazoefficiens to grow under denitrifying conditions. However, by using qRT-PCR analyses, we showed that nirK and norCBQD expression was much lower in the csoR mutant compared to wild-type levels under Cu-limiting denitrifying conditions. On the contrary, copA expression was significantly increased in the csoR mutant. The results obtained suggest that CsoR acts as a repressor of copA. Under Cu limitation, CsoR has also an indirect role in the expression of nirK and norCBQD genes.}, }
@article {pmid37567493, year = {2023}, author = {Kamkong, P and Jitsamai, W and Thongmeesee, K and Ratthawongjirakul, P and Taweethavonsawat, P}, title = {Genetic diversity and characterization of Wolbachia endosymbiont in canine filariasis.}, journal = {Acta tropica}, volume = {246}, number = {}, pages = {107000}, doi = {10.1016/j.actatropica.2023.107000}, pmid = {37567493}, issn = {1873-6254}, abstract = {Canine filariasis is caused by nematodes from the family Onchocercidae, which is transmitted by arthropod vectors. The disease is commonly found in Southeast Asia and exists worldwide. Some filarial nematodes are associated with intracellular bacteria of the genus Wolbachia, which plays an important role in embryogenesis, molting, and the long-term survival of adult worms. This study aims to characterize Wolbachia sp. and determine the association between Wolbachia and canine filarial nematode species in Thailand. A total of 46 dog blood samples that were naturally infected with filarial nematodes were obtained to identify filarial nematode species by Giemsa stained under a light microscope and confirmed using the molecular technique. In order to characterize Wolbachia sp., the nested PCR assay targeting the 16S rRNA gene showed that all samples of Dirofilaria immitis and fifteen samples of Candidatus Dirofilaria hongkongensis were grouped into Wolbachia supergroup C. In addition, all samples of Brugia spp. and five samples of Candidatus Dirofilaria hongkongensis were classified into Wolbachia supergroup D. The genetic diversity analysis conducted using the 16S rRNA gene revealed a similar result when analyzed through phylogenetic tree analysis. This is the first genetic diversity study of Wolbachia of Candidatus Dirofilaria hongkongensis in infected dogs in Thailand.}, }
@article {pmid37564291, year = {2023}, author = {Salem, H and Biedermann, PHW and Fukatsu, T}, title = {Editorial: Diversity of beetles and associated microorganisms.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1252736}, pmid = {37564291}, issn = {1664-302X}, }
@article {pmid37555448, year = {2023}, author = {Zhang, R and Shen, Y and He, J and Zhang, C and Ma, Y and Sun, C and Son, X and Li, L and Zhang, S and Biró, JB and Saifi, F and Kalo, P and Chen, R}, title = {Nodule-Specific Cysteine-Rich Peptide 343 is required for symbiotic nitrogen fixation in Medicago truncatula.}, journal = {Plant physiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/plphys/kiad454}, pmid = {37555448}, issn = {1532-2548}, abstract = {Symbiotic interactions between legumes and rhizobia lead to development of root nodules and nitrogen fixation by differentiated bacteroids within nodules. Differentiation of the endosymbionts is reversible or terminal, determined by plant effectors. In IRLC legumes, Nodule-Specific Cysteine-Rich Peptides (NCRs) control the terminal differentiation of bacteroids. Medicago truncatula contains ∼700 NCR-coding genes. However, the role of few NCRs has been demonstrated. Here, we report characterization of FN2106 (Fast Neutron 2106), a symbiotic nitrogen fixation defective (fix-) mutant of M. truncatula. Using a transcript-based approach, together with linkage and complementation tests, we showed that loss-of-function of NCR343 results in impaired bacteroid differentiation and/or maintenance and premature nodule senescence of the FN2106 mutant. NCR343 was specifically expressed in nodules. Subcellular localization studies showed that the functional NCR343-YFP fusion protein colocalizes with bacteroids in symbiosomes in infected nodule cells. Transcriptomic analyses identified senescence-, but not defense-related genes, as being significantly upregulated in ncr343 (FN2106) nodules. Taken together, results from our phenotypic and transcriptomic analyses of a loss-of-function ncr343 mutant demonstrate an essential role of NCR343 in bacteroid differentiation and/or maintenance required for symbiotic nitrogen fixation.}, }
@article {pmid37555448, year = {2023}, author = {Zhang, R and Shen, Y and He, J and Zhang, C and Ma, Y and Sun, C and Son, X and Li, L and Zhang, S and Biró, JB and Saifi, F and Kalo, P and Chen, R}, title = {Nodule-Specific Cysteine-Rich Peptide 343 is required for symbiotic nitrogen fixation in Medicago truncatula.}, journal = {Plant physiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/plphys/kiad454}, pmid = {37555448}, issn = {1532-2548}, abstract = {Symbiotic interactions between legumes and rhizobia lead to development of root nodules and nitrogen fixation by differentiated bacteroids within nodules. Differentiation of the endosymbionts is reversible or terminal, determined by plant effectors. In IRLC legumes, Nodule-Specific Cysteine-Rich Peptides (NCRs) control the terminal differentiation of bacteroids. Medicago truncatula contains ∼700 NCR-coding genes. However, the role of few NCRs has been demonstrated. Here, we report characterization of FN2106 (Fast Neutron 2106), a symbiotic nitrogen fixation defective (fix-) mutant of M. truncatula. Using a transcript-based approach, together with linkage and complementation tests, we showed that loss-of-function of NCR343 results in impaired bacteroid differentiation and/or maintenance and premature nodule senescence of the FN2106 mutant. NCR343 was specifically expressed in nodules. Subcellular localization studies showed that the functional NCR343-YFP fusion protein colocalizes with bacteroids in symbiosomes in infected nodule cells. Transcriptomic analyses identified senescence-, but not defense-related genes, as being significantly upregulated in ncr343 (FN2106) nodules. Taken together, results from our phenotypic and transcriptomic analyses of a loss-of-function ncr343 mutant demonstrate an essential role of NCR343 in bacteroid differentiation and/or maintenance required for symbiotic nitrogen fixation.}, }
@article {pmid37545710, year = {2023}, author = {Dzul-Rosado, KR and Arroyo-Solís, KA and Torres-Monroy, AJ and Arias-León, JJ and Peniche-Lara, GF and Puerto-Manzano, FI and Landa-Flores, MG and Del Mazo-López, JC and Salceda-Sánchez, B}, title = {Tick-associated diseases identified from hunting dogs during the COVID-19 pandemic in a Mayan community in Yucatan, Mexico.}, journal = {Open veterinary journal}, volume = {13}, number = {6}, pages = {794-800}, pmid = {37545710}, issn = {2218-6050}, abstract = {BACKGROUND: Hunting activity in the Mayan communities has increased due to COVID-19 and domestic dogs have gained more importance. Due to their proximity to humans, domestic dogs are a bridge between tick-borne diseases (TBDs) and humans and their peri-domestic environment. In Mexico, and especially in rural regions, there were not adequate records of TBDs during the SARS-CoV-2 pandemic.<br><br>AIM: Identify TBD of ticks collected during the COVID-19 pandemic in a rural community.<br><br>METHODS: Tick capture was carried out in March 2021, in Teabo, Yucatan. Ticks were removed using from domestic dogs and placed in ethanol. Collected ticks were morphologically identified and underwent DNA extraction and a partial segment of the mitochondrial 16S-rDNA gene was amplified to corroborate the tick species. The DNA was screened for the presence of Anaplasma spp., Borrelia spp., Ehrlichia spp., and Rickettsia spp. Purified amplification products were submitted for sequencing and the results were compared to those deposited in GenBank using BLAST.<br><br>RESULTS: We collected 33 ectoparasites, Ixodes affinis, Rhipicephalus sanguineus, Rhipicephalus microplus, and Amblyomma mixtum on 11 hunting dogs. The most frequent ectoparasite was R. sanguineus (66%). We detected the presence of DNA of Rickettsia endosymbiont in I. affinis and Anaplasma platys in R. sanguineus. Rickettsia endosymbiont presented a similarity of 100% with the partial sequence of R. endosymbiont of I. affinis isolate IACACTM001 16S ribosomal RNA gene and the sequence of A. platys had a similarity of 100% with the partial sequence of the isolate 23-33TX 16S ribosomal RNA gene of A. platys from dogs from Texas, USA and with the partial sequence of the isolate L134 16S ribosomal RNA gene of Ehrlichia canis from dogs from Piura, Peru.<br><br>CONCLUSION: We confirmed for the first time the presence of A. platys in R. sanguineus and R. endosymbiont in I. affinis ticks from dogs in the state of Yucatan.}, }
@article {pmid37543226, year = {2023}, author = {Li, Q and Fu, D and Zhou, Y and Li, Y and Chen, L and Wang, Z and Wan, Y and Huang, Z and Zhao, H}, title = {Individual and combined effects of herbicide prometryn and nitrate enrichment at environmentally relevant concentrations on photosynthesis, oxidative stress, and endosymbiont community diversity of coral Acropora hyacinthus.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {139729}, doi = {10.1016/j.chemosphere.2023.139729}, pmid = {37543226}, issn = {1879-1298}, abstract = {Nitrogen pollution and pesticides such as photosystem II (PSII) inhibitor herbicides have several detrimental impacts on coral reefs, including breakdown of the symbiosis between host corals and photosynthetic symbionts. Although nitrogen and PSII herbicide pollution separately cause coral bleaching, the combined effects of these stressors at environmentally relevant concentrations on corals have not been assessed. Here, we report the combined effects of nitrate enrichment and PSII herbicide (prometryn) exposure on photosynthesis, oxidative status and endosymbiont community diversity of the reef-building coral Acropora hyacinthus. Coral fragments were exposed in a mesocosm system to nitrate enrichment (9 μmol/L) and two prometryn concentrations (1 and 5 μg/L). The results showed that sustained prometryn exposure in combination with nitrate enrichment stress had significant detrimental impacts on photosynthetic apparatus [the maximum quantum efficiency of photosystem II (Fv/Fm), nonphotochemical quenching (NPQ)] and oxidative status in the short term. Nevertheless, the adaptive mechanism of corals allowed the normal physiological state to be recovered following 1 μg/L prometryn and 9 μmol/L nitrate enrichment individual exposure. Moreover, exposure for 9 days was insufficient to trigger a shift in Symbiodiniaceae community. Most importantly, the negative impact of exposure to the combined environmental concentrations of 1 μg/L prometryn and 9 μmol/L nitrate enrichment was found to be significantly greater on the Fv/Fm, quantum yield of non-regulated energy dissipation [Y(NO)], NPQ, and oxidative status of corals compared to the impact of individual stressors. Our results show that interactions between prometryn stress and nitrate enrichment have a synergistic impact on the photosynthetic and oxidative stress responses of corals. This study provides valuable insights into combined effects of nitrate enrichment and PSII herbicides pollution for coral's physiology. Environmental concentrations of PSII herbicides may be more harmful to photosystems and antioxidant systems of corals under nitrate enrichment stress. Thus, future research and management of seawater quality stressors should consider combined impacts rather than just the impacts of individual stressors alone.}, }
@article {pmid37525959, year = {2023}, author = {Kolasa, M and Kajtoch, &#x141; and Michalik, A and Maryańska-Nadachowska, A and Łukasik, P}, title = {Till evolution do us part: The diversity of symbiotic associations across populations of Philaenus spittlebugs.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16473}, pmid = {37525959}, issn = {1462-2920}, support = {PPN/PPO/2018/1/00015//Narodowa Agencja Wymiany Akademickiej/ ; 2018/30/E/NZ8/00880//Narodowe Centrum Nauki/ ; 2018/31/B/NZ8/01158//Narodowe Centrum Nauki/ ; }, abstract = {Symbiotic bacteria have played crucial roles in the evolution of sap-feeding insects and can strongly affect host function. However, their diversity and distribution within species are not well understood; we do not know to what extent environmental factors or associations with other species may affect microbial community profiles. We addressed this question in Philaenus spittlebugs by surveying both insect and bacterial marker gene amplicons across multiple host populations. Host mitochondrial sequence data confirmed morphology-based identification of six species and revealed two divergent clades of Philaenus spumarius. All of them hosted the primary symbiont Sulcia that was almost always accompanied by Sodalis. Interestingly, populations and individuals often differed in the presence of Sodalis sequence variants, suggestive of intra-genome 16S rRNA variant polymorphism combined with rapid genome evolution and/or recent additional infections or replacements of the co-primary symbiont. The prevalence of facultative endosymbionts, including Wolbachia, Rickettsia, and Spiroplasma, varied among populations. Notably, cytochrome I oxidase (COI) amplicon data also showed that nearly a quarter of P. spumarius were infected by parasitoid flies (Verralia aucta). One of the Wolbachia operational taxonomic units (OTUs) was exclusively present in Verralia-parasitized specimens, suggestive of parasitoids as their source and highlighting the utility of host gene amplicon sequencing in microbiome studies.}, }
@article {pmid37520253, year = {2023}, author = {Dong, AZ and Cokcetin, N and Carter, DA and Fernandes, KE}, title = {Unique antimicrobial activity in honey from the Australian honeypot ant (Camponotus inflatus).}, journal = {PeerJ}, volume = {11}, number = {}, pages = {e15645}, pmid = {37520253}, issn = {2167-8359}, abstract = {Honey produced by the Australian honeypot ant (Camponotus inflatus) is valued nutritionally and medicinally by Indigenous peoples, but its antimicrobial activity has never been formally studied. Here, we determine the activity of honeypot ant honey (HPAH) against a panel of bacterial and fungal pathogens, investigate its chemical properties, and profile the bacterial and fungal microbiome of the honeypot ant for the first time. We found HPAH to have strong total activity against Staphylococcus aureus but not against other bacteria, and strong non-peroxide activity against Cryptococcus and Aspergillus sp. When compared with therapeutic-grade jarrah and manuka honey produced by honey bees, we found HPAH to have a markedly different antimicrobial activity and chemical properties, suggesting HPAH has a unique mode of antimicrobial action. We found the bacterial microbiome of honeypot ants to be dominated by the known endosymbiont genus Candidatus Blochmannia (99.75%), and the fungal microbiome to be dominated by the plant-associated genus Neocelosporium (92.77%). This study demonstrates that HPAH has unique antimicrobial characteristics that validate its therapeutic use by Indigenous peoples and may provide a lead for the discovery of novel antimicrobial compounds.}, }
@article {pmid37513789, year = {2023}, author = {Holguin-Rocha, AF and Calle-Tobon, A and Vásquez, GM and Astete, H and Fisher, ML and Tobon-Castano, A and Velez-Tobon, G and Maldonado-Ruiz, LP and Silver, K and Park, Y and Londono-Renteria, B}, title = {Diversity of the Bacterial and Viral Communities in the Tropical Horse Tick, Dermacentor nitens, in Colombia.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {7}, pages = {}, doi = {10.3390/pathogens12070942}, pmid = {37513789}, issn = {2076-0817}, support = {AI163423/NH/NIH HHS/United States ; }, abstract = {Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The microbial and viral communities of ticks, including pathogenic microorganisms, are known to be highly diverse. However, the factors driving this diversity are not well understood. The tropical horse tick, Dermacentor nitens, is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi, the causal agents of equine piroplasmosis. In this study, we characterized the bacterial and viral communities associated with partially fed Dermacentor nitens females collected using a passive survey on horses from field sites representing three distinct geographical areas in the country of Colombia (Bolivar, Antioquia, and Cordoba). RNA-seq and sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene were performed using the Illumina-Miseq platform (Illumina, San Diego, CA, USA). A total of 356 operational taxonomic units (OTUs) were identified, in which the presumed endosymbiont, Francisellaceae/Francisella spp., was predominantly found. Nine contigs corresponding to six different viruses were identified in three viral families: Chuviridae, Rhabdoviridae, and Flaviviridae. Differences in the relative abundance of the microbial composition among the geographical regions were found to be independent of the presence of Francisella-like endosymbiont (FLE). The most prevalent bacteria found in each region were Corynebacterium in Bolivar, Staphylococcus in Antioquia, and Pseudomonas in Cordoba. Rickettsia-like endosymbionts, mainly recognized as the etiological agent of rickettsioses in Colombia, were detected in the Cordoba samples. Metatranscriptomics revealed 13 contigs containing FLE genes, suggesting a trend of regional differences. These findings suggest regional distinctions among the ticks and their bacterial compositions.}, }
@article {pmid37508385, year = {2023}, author = {Cazzaniga, M and Domínguez-Santos, R and Marín-Miret, J and Gil, R and Latorre, A and García-Ferris, C}, title = {Exploring Gut Microbial Dynamics and Symbiotic Interaction in Blattella germanica Using Rifampicin.}, journal = {Biology}, volume = {12}, number = {7}, pages = {}, doi = {10.3390/biology12070955}, pmid = {37508385}, issn = {2079-7737}, support = {PGC2018-099344-B-I00//MCIN/AEI/10.13039/501100011033 (Spain) and "ERDF A way of making Europe"/ ; PID2021-128201NB-I00//MCIN/AEI/10.13039/501100011033 (Spain) and "ERDF A way of making Europe"/ ; Prometeo/2018/A/133//Conselleria d'Educaci&#xf3;, Generalitat Valenciana/ ; CIPROM/2021/042//Conselleria d'Educaci&#xf3;, Generalitat Valenciana/ ; }, abstract = {Blattella germanica harbours two cohabiting symbiotic systems: an obligate endosymbiont, Blattabacterium, located inside bacteriocytes and vertically transmitted, which is key in nitrogen metabolism, and abundant and complex gut microbiota acquired horizontally (mainly by coprophagy) that must play an important role in host physiology. In this work, we use rifampicin treatment to deepen the knowledge on the relationship between the host and the two systems. First, we analysed changes in microbiota composition in response to the presence and removal of the antibiotic with and without faeces in one generation. We found that, independently of faeces supply, rifampicin-sensitive bacteria are strongly affected at four days of treatment, and most taxa recover after treatment, although some did not reach control levels. Second, we tried to generate an aposymbiotic population, but individuals that reached the second generation were severely affected and no third generation was possible. Finally, we established a mixed population with quasi-aposymbiotic and control nymphs sharing an environment in a blind experiment. The analysis of the two symbiotic systems in each individual after reaching the adult stage revealed that endosymbiont's load does not affect the composition of the hindgut microbiota, suggesting that there is no interaction between the two symbiotic systems in Blattella germanica.}, }
@article {pmid37497544, year = {2023}, author = {Kanyile, SN and Engl, T and Heddi, A and Kaltenpoth, M}, title = {Endosymbiosis allows Sitophilus oryzae to persist in dry conditions.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1199370}, pmid = {37497544}, issn = {1664-302X}, abstract = {Insects frequently associate with intracellular microbial symbionts (endosymbionts) that enhance their ability to cope with challenging environmental conditions. Endosymbioses with cuticle-enhancing microbes have been reported in several beetle families. However, the ecological relevance of these associations has seldom been demonstrated, particularly in the context of dry environments where high cuticle quality can reduce water loss. Thus, we investigated how cuticle-enhancing symbionts of the rice-weevil, Sitophilus oryzae contribute to desiccation resistance. We exposed symbiotic and symbiont-free (aposymbiotic) beetles to long-term stressful (47% RH) or relaxed (60% RH) humidity conditions and measured population growth. We found that symbiont presence benefits host fitness especially under dry conditions, enabling symbiotic beetles to increase their population size by over 33-fold within 3 months, while aposymbiotic beetles fail to increase in numbers beyond the starting population in the same conditions. To understand the mechanisms underlying this drastic effect, we compared beetle size and body water content and found that endosymbionts confer bigger body size and higher body water content. While chemical analyses revealed no significant differences in composition and quantity of cuticular hydrocarbons after long-term exposure to desiccation stress, symbiotic beetles lost water at a proportionally slower rate than did their aposymbiotic counterparts. We posit that the desiccation resistance and higher fitness observed in symbiotic beetles under dry conditions is due to their symbiont-enhanced thicker cuticle, which provides protection against cuticular transpiration. Thus, we demonstrate that the cuticle enhancing symbiosis of Sitophilus oryzae confers a fitness benefit under drought stress, an ecologically relevant condition for grain pest beetles. This benefit likely extends to many other systems where symbiont-mediated cuticle synthesis has been identified, including taxa spanning beetles and ants that occupy different ecological niches.}, }
@article {pmid37490862, year = {2023}, author = {Dijksterhuis, J}, title = {Endosymbionts: Bacterial hijacking of fungi?.}, journal = {Current biology : CB}, volume = {33}, number = {14}, pages = {R765-R767}, doi = {10.1016/j.cub.2023.06.028}, pmid = {37490862}, issn = {1879-0445}, abstract = {Bacteria inside fungal hyphae allow the fungus Rhizopus microsporus to form spores and operate via effectors in 'stealth' mode. When the functionality of one effector is taken away, bacteria are captured in septated cells and die.}, }
@article {pmid37488011, year = {2023}, author = {Seo Jeon, M and Han, SI and Ahn, JW and Jung, JH and Choi, JS and Choi, YE}, title = {Endophyte Bacillus tequilensis improves the growth of microalgae Haematococcus lacustris by regulating host cell metabolism.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {129546}, doi = {10.1016/j.biortech.2023.129546}, pmid = {37488011}, issn = {1873-2976}, abstract = {This study identified an endosymbiotic bacterium, Bacillus tequilensis, residing within the cells of the microalga Haematococcus lacustris through 16S rRNA analysis. To confirm the optimal interactive conditions between H. lacustris and B. tequilensis, the effects of different ratios of cells using H. lacustris of different growth stages were examined. Under optimized conditions, the cell density, dry weight, chlorophyll content, and astaxanthin content of H. lacustris increased significantly, and the fatty acid content improved 1.99-fold. Microscopy demonstrated the presence of bacteria within the H. lacustris cells. The interaction upregulated amino acid and nucleotide metabolism in H. lacustris. Interestingly, muramic and phenylacetic acids were found exclusively in H. lacustris cells in the presence of B. tequilensis. Furthermore, B. tequilensis delayed pigment degradation in H. lacustris. This study reveals the impact of the endosymbiont B. tequilensis on the metabolism of H. lacustris and offers new perspectives on the symbiotic relationship between them.}, }
@article {pmid37484687, year = {2023}, author = {Adams, GJ and O'Brien, PA}, title = {The unified theory of sleep: Eukaryotes endosymbiotic relationship with mitochondria and REM the push-back response for awakening.}, journal = {Neurobiology of sleep and circadian rhythms}, volume = {15}, number = {}, pages = {100100}, pmid = {37484687}, issn = {2451-9944}, abstract = {The Unified Theory suggests that sleep is a process that developed in eukaryotic animals from a relationship with an endosymbiotic bacterium. Over evolutionary time the bacterium evolved into the modern mitochondrion that continues to exert an effect on sleep patterns, e.g. the bacterium Wolbachia establishes an endosymbiotic relationship with Drosophila and many other species of insects and is able to change the host's behaviour by making it sleep. The hypothesis is supported by other host-parasite relationships, e.g., Trypanosoma brucei which causes day-time sleepiness and night-time insomnia in humans and cattle. For eukaryotes such as Monocercomonoids that don't contain mitochondria we find no evidence of them sleeping. Mitochondria produce the neurotransmitter gamma aminobutyric acid (GABA), and ornithine a precursor of the neurotransmitter GABA, together with substances such as 3,4dihydroxy phenylalanine (DOPA) a precursor for the neurotransmitter dopamine: These substances have been shown to affect the sleep/wake cycles in animals such as Drosophilia and Hydra. Eukaryote animals have traded the very positive side of having mitochondria providing aerobic respiration for them with the negative side of having to sleep. NREM (Quiet sleep) is the process endosymbionts have imposed upon their host eukaryotes and REM (Active sleep) is the push-back adaptation of eukaryotes with brains, returning to wakefulness.}, }
@article {pmid37479750, year = {2023}, author = {Pan, Q and Yu, SJ and Lei, S and Li, SC and Ding, LL and Liu, L and Cheng, LY and Luo, R and Lei, CY and Lou, BH and Cong, L and Liu, HQ and Wang, XF and Ran, C}, title = {Effects of Candidatus Liberibacter asiaticus infection on metagenome of Diaphorina citri gut endosymbiont.}, journal = {Scientific data}, volume = {10}, number = {1}, pages = {478}, pmid = {37479750}, issn = {2052-4463}, abstract = {Asian citrus psyllid (Diaphorina citri, D. citri) is the important vector of "Candidatus Liberibacter asiaticus" (CLas), associated with Huanglongbing, the most devastating citrus disease worldwide. CLas can affect endosymbiont abundance of D. citri. Here, we generated the high-quality gut endosymbiont metagenomes of Diaphorina citri on the condition of CLas infected and uninfected. The dataset comprised 6616.74 M and 6586.04 M raw reads, on overage, from CLas uninfected and infected psyllid strains, respectively. Taxonomic analysis revealed that a total of 1046 species were annotated with 10 Archaea, 733 Bacteria, 234 Eukaryota, and 69 Viruses. 80 unique genera in CLas infected D. citri were identified. DIAMOND software was used for complement function research against various functional databases, including Nr, KEGG, eggNOG, and CAZy, which annotated 84543 protein-coding genes. These datasets provided an avenue for further study of the interaction mechanism between CLas and D. citri.}, }
@article {pmid37477269, year = {2023}, author = {Ferreira, MU and Crainey, JL and Gobbi, FG}, title = {The search for better treatment strategies for mansonellosis: An expert perspective.}, journal = {Expert opinion on pharmacotherapy}, volume = {}, number = {}, pages = {}, doi = {10.1080/14656566.2023.2240235}, pmid = {37477269}, issn = {1744-7666}, abstract = {INTRODUCTION: Four species of the Mansonella genus infect millions of people across sub-Saharan Africa and Central and South America. Most infections are asymptomatic, but mansonellosis can be associated with unspecific clinical manifestations such as fever, headache, arthralgia, and ocular lesions (M. ozzardi); pruritus, arthralgia, abdominal pain, angioedema, skin rash, and fatigue (M. perstans and perhaps Mansonella sp 'DEUX'); and pruritic dermatitis and chronic lymphadenitis (M. perstans).<br><br>AREAS COVERED: We searched the PubMed and SciELO databases for publications on mansonelliasis in English, Spanish, Portuguese, or French that appeared until 1 May 2023. Literature data show that anthelmintics - single-dose ivermectin for M. ozzardi, repeated doses of mebendazole alone or in combination with diethylcarbamazine (DEC) for M. perstans, and DEC alone for M. streptocerca - are effective against microfilariae. Antibiotics that target Wolbachia endosymbionts, such as doxycycline, are likely to kill adult worms of most, if not all, Mansonella species, but the currently recommended 6-week regimen is relatively unpractical. New anthelminthics and shorter antibiotic regimens (e.g. with rifampin) have showed promise in experimental filarial infections and may proceed to clinical trials.<br><br>EXPERT OPINION: We recommend that human infections with Mansonella species be treated, regardless of any apparent clinical manifestations. We argue that mansonellosis, despite being widely considered a benign infection, may represent a direct or indirect cause of significant morbidity that remains poorly characterized at present.}, }
@article {pmid37468834, year = {2023}, author = {Campbell, LI and Nwezeobi, J and van Brunschot, SL and Kaweesi, T and Seal, SE and Swamy, RAR and Namuddu, A and Maslen, GL and Mugerwa, H and Armean, IM and Haggerty, L and Martin, FJ and Malka, O and Santos-Garcia, D and Juravel, K and Morin, S and Stephens, ME and Muhindira, PV and Kersey, PJ and Maruthi, MN and Omongo, CA and Navas-Castillo, J and Fiallo-Olivé, E and Mohammed, IU and Wang, HL and Onyeka, J and Alicai, T and Colvin, J}, title = {Comparative evolutionary analyses of eight whitefly Bemisia tabaci sensu lato genomes: cryptic species, agricultural pests and plant-virus vectors.}, journal = {BMC genomics}, volume = {24}, number = {1}, pages = {408}, pmid = {37468834}, issn = {1471-2164}, support = {WT108749/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; WT108749/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; WT108749/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; }, abstract = {BACKGROUND: The group of > 40 cryptic whitefly species called Bemisia tabaci sensu lato are amongst the world's worst agricultural pests and plant-virus vectors. Outbreaks of B. tabaci s.l. and the associated plant-virus diseases continue to contribute to global food insecurity and social instability, particularly in sub-Saharan Africa and Asia. Published B. tabaci s.l. genomes have limited use for studying African cassava B. tabaci SSA1 species, due to the high genetic divergences between them. Genomic annotations presented here were performed using the 'Ensembl gene annotation system', to ensure that comparative analyses and conclusions reflect biological differences, as opposed to arising from different methodologies underpinning transcript model identification.<br><br>RESULTS: We present here six new B. tabaci s.l. genomes from Africa and Asia, and two re-annotated previously published genomes, to provide evolutionary insights into these globally distributed pests. Genome sizes ranged between 616-658&#xa0;Mb and exhibited some of the highest coverage of transposable elements reported within Arthropoda. Many fewer total protein coding genes (PCG) were recovered compared to the previously published B. tabaci s.l. genomes and structural annotations generated via the uniform methodology strongly supported a repertoire of between 12.8-13.2&#x2009;&#xd7;&#x2009;10[3] PCG. An integrative systematics approach incorporating phylogenomic analysis of nuclear and mitochondrial markers supported a monophyletic Aleyrodidae and the basal positioning of B. tabaci Uganda-1 to the sub-Saharan group of species. Reciprocal cross-mating data and the co-cladogenesis pattern of the primary obligate endosymbiont 'Candidatus Portiera aleyrodidarum' from 11 Bemisia genomes further supported the phylogenetic reconstruction to show that African cassava B. tabaci populations consist of just three biological species. We include comparative analyses of gene families related to detoxification, sugar metabolism, vector competency and evaluate the presence and function of horizontally transferred genes, essential for understanding the evolution and unique biology of constituent B. tabaci. s.l species.<br><br>CONCLUSIONS: These genomic resources have provided new and critical insights into the genetics underlying B. tabaci s.l. biology. They also provide a rich foundation for post-genomic research, including the selection of candidate gene-targets for innovative whitefly and virus-control strategies.}, }
@article {pmid37468804, year = {2023}, author = {Muñoz-García, CI and Rendón-Franco, E and Grostieta, E and Navarrete-Sotelo, M and Sánchez-Montes, S}, title = {Novel Francisella-like endosymbiont and Anaplasma species from Amblyomma nodosum hosted by the anteater Tamandua Mexicana in Mexico.}, journal = {Experimental &amp; applied acarology}, volume = {}, number = {}, pages = {}, pmid = {37468804}, issn = {1572-9702}, abstract = {The microbiome represents a complex network among the various members of the community of microorganisms that are associated with a host. The composition of the bacterial community is essential to supplement multiple metabolic pathways that the host lacks, particularly in organisms with blood-sucking habits such as ticks. On the other hand, some endosymbionts showed some competence with potentially pathogenic microorganisms. Francisella-like endosymbionts (FLEs) encompass a group of gamma-proteobacterias that are closely related to Francisella tularensis, but are usually apathogenic, which brings nutrients like vitamin B and other cofactors to the tick. It has been postulated that the main route of transmission of FLE is vertical; however, evidence has accumulated regarding the possible mechanism of horizontal transmission. Despite growing interest in knowledge of endosymbionts in the Neotropical region, the efforts related to the establishment of their inventory for tick communities are concentrated in South and Central America, with an important gap in knowledge in Mesoamerican countries such as Mexico. For this reason, the aim of this work was to evaluate the presence and diversity of endosymbionts in the highly host-specialized tick Amblyomma nodosum collected from the anteater Tamandua mexicana in Mexico. We analysed 36 A. nodosum for the presence of DNA of endosymbiont (Coxiella and Francisella) and pathogenic (Anaplasma, Borrelia, Ehrlichia and Rickettsia) bacteria. The presence of a member of the genus Francisella and Candidatus Anaplasma brasiliensis was demonstrated. Our findings provide information on the composition of A. nodosum's microbiome, increasing the inventory of bacterial species associated with this hard tick on the American continent.}, }
@article {pmid37464760, year = {2023}, author = {Mather, RV and Larsen, TJ and Brock, DA and Queller, DC and Strassmann, JE}, title = {Paraburkholderia symbionts isolated from Dictyostelium discoideum induce bacterial carriage in other Dictyostelium species.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2003}, pages = {20230977}, doi = {10.1098/rspb.2023.0977}, pmid = {37464760}, issn = {1471-2954}, abstract = {The social amoeba Dictyostelium discoideum engages in a complex relationship with bacterial endosymbionts in the genus Paraburkholderia, which can benefit their host by imbuing it with the ability to carry prey bacteria throughout its life cycle. The relationship between D. discoideum and Paraburkholderia has been shown to take place across many strains and a large geographical area, but little is known about Paraburkholderia's potential interaction with other dictyostelid species. We explore the ability of three Paraburkholderia species to stably infect and induce bacterial carriage in other dictyostelid hosts. We found that all three Paraburkholderia species successfully infected and induced carriage in seven species of Dictyostelium hosts. While the overall behaviour was qualitatively similar to that previously observed in infections of D. discoideum, differences in the outcomes of different host/symbiont combinations suggest a degree of specialization between partners. Paraburkholderia was unable to maintain a stable association with the more distantly related host Polysphondylium violaceum. Our results suggest that the mechanisms and evolutionary history of Paraburkholderia's symbiotic relationships may be general within Dictyostelium hosts, but not so general that it can associate with hosts of other genera. Our work further develops an emerging model system for the study of symbiosis in microbes.}, }
@article {pmid37452489, year = {2023}, author = {Qiao, SA and Gao, Z and Roth, R}, title = {A perspective on cross-kingdom RNA interference in mutualistic symbioses.}, journal = {The New phytologist}, volume = {}, number = {}, pages = {}, doi = {10.1111/nph.19122}, pmid = {37452489}, issn = {1469-8137}, support = {BB/T008784/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {RNA interference (RNAi) is arguably one of the more versatile mechanisms in cell biology, facilitating the fine regulation of gene expression and protection against mobile genomic elements, whilst also constituting a key aspect of induced plant immunity. More recently, the use of this mechanism to regulate gene expression in heterospecific partners - cross-kingdom RNAi (ckRNAi) - has been shown to form a critical part of bidirectional interactions between hosts and endosymbionts, regulating the interplay between microbial infection mechanisms and host immunity. Here, we review the current understanding of ckRNAi as it relates to interactions between plants and their pathogenic and mutualistic endosymbionts, with particular emphasis on evidence in support of ckRNAi in the arbuscular mycorrhizal symbiosis.}, }
@article {pmid37438329, year = {2023}, author = {Uzum, Z and Ershov, D and Pavia, MJ and Mallet, A and Gorgette, O and Plantard, O and Sassera, D and Stavru, F}, title = {Three-dimensional images reveal the impact of the endosymbiont Midichloria mitochondrii on the host mitochondria.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {4133}, pmid = {37438329}, issn = {2041-1723}, support = {RGY-0075//Human Frontier Science Program (HFSP)/ ; RGY-0075//Human Frontier Science Program (HFSP)/ ; RGY-0075//Human Frontier Science Program (HFSP)/ ; RGY-0075//Human Frontier Science Program (HFSP)/ ; }, abstract = {The hard tick, Ixodes ricinus, a main Lyme disease vector, harbors an intracellular bacterial endosymbiont. Midichloria mitochondrii is maternally inherited and resides in the mitochondria of I. ricinus oocytes, but the consequences of this endosymbiosis are not well understood. Here, we provide 3D images of wild-type and aposymbiotic I. ricinus oocytes generated with focused ion beam-scanning electron microscopy. Quantitative image analyses of endosymbionts and oocyte mitochondria at different maturation stages show that the populations of both mitochondrion-associated bacteria and bacterium-hosting mitochondria increase upon vitellogenisation, and that mitochondria can host multiple bacteria in later stages. Three-dimensional reconstructions show symbiosis-dependent morphologies of mitochondria and demonstrate complete M. mitochondrii inclusion inside a mitochondrion. Cytoplasmic endosymbiont located close to mitochondria are not oriented towards the mitochondria, suggesting that bacterial recolonization is unlikely. We further demonstrate individual globular-shaped mitochondria in the wild type oocytes, while aposymbiotic oocytes only contain a mitochondrial network. In summary, our study suggests that M. mitochondrii modulates mitochondrial fragmentation in oogenesis possibly affecting organelle function and ensuring its presence over generations.}, }
@article {pmid37433980, year = {2023}, author = {Candelori, A and Di Giuseppe, G and Villalobo, E and Sjödin, A and Vallesi, A}, title = {Bipolar Biogeographical Distribution of Parafrancisella Bacteria Carried by the Ciliate Euplotes.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {37433980}, issn = {1432-184X}, support = {PNRA18_00152//PNRA (Programma Nazionale di Ricerca in Antartide)/ ; PNRA18_00152//PNRA (Programma Nazionale di Ricerca in Antartide)/ ; }, abstract = {Parafrancisella adeliensis, a Francisella-like endosymbiont, was found to reside in the cytoplasm of an Antarctic strain of the bipolar ciliate species, Euplotes petzi. To inquire whether Euplotes cells collected from distant Arctic and peri-Antarctic sites host Parafrancisella bacteria, wild-type strains of the congeneric bipolar species, E. nobilii, were screened for Parafrancisella by in situ hybridization and 16S gene amplification and sequencing. Results indicate that all Euplotes strains analyzed contained endosymbiotic bacteria with 16S nucleotide sequences closely similar to the P. adeliensis 16S gene sequence. This finding suggests that Parafrancisella/Euplotes associations are not endemic to Antarctica, but are common in both the Antarctic and Arctic regions.}, }
@article {pmid37430172, year = {2023}, author = {Porter, J and Sullivan, W}, title = {The cellular lives of Wolbachia.}, journal = {Nature reviews. Microbiology}, volume = {}, number = {}, pages = {}, pmid = {37430172}, issn = {1740-1534}, abstract = {Wolbachia are successful Gram-negative bacterial endosymbionts, globally infecting a large fraction of arthropod species and filarial nematodes. Efficient vertical transmission, the capacity for horizontal transmission, manipulation of host reproduction and enhancement of host fitness can promote the spread both within and between species. Wolbachia are abundant and can occupy extraordinary diverse and evolutionary distant host species, suggesting that they have evolved to engage and manipulate highly conserved core cellular processes. Here, we review recent studies identifying Wolbachia-host interactions at the molecular and cellular levels. We explore how Wolbachia interact with a wide array of host cytoplasmic and nuclear components in order to thrive in a diversity of cell types and cellular environments. This endosymbiont has also evolved the ability to precisely target and manipulate specific phases of the host cell cycle. The remarkable diversity of cellular interactions distinguishes Wolbachia from other endosymbionts and is largely responsible for facilitating its global propagation through host populations. Finally, we describe how insights into Wolbachia-host cellular interactions have led to promising applications in controlling insect-borne and filarial nematode-based diseases.}, }
@article {pmid37424778, year = {2023}, author = {Zhou, JC and Dong, QJ and Shang, D and Ning, SF and Zhang, HH and Wang, Y and Che, WN and Dong, H and Zhang, LS}, title = {Posterior concentration of Wolbachia during the early embryogenesis of the host dynamically shapes the tissue tropism of Wolbachia in host Trichogramma wasps.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1198428}, pmid = {37424778}, issn = {2235-2988}, abstract = {INTRODUCTION: The bacterial endosymbiont, Wolbachia spp. induce thelytokous parthenogenesis in certain parasitoid wasps, such as the egg parasitoid wasps Trichogramma spp. To complete the cycle of vertical transmission, Wolbachia displays efficient transovarial transmission by targeting the reproductive tissues and often exhibits strong tissue-specific tropism in their host.<br><br>METHOD: The present study aimed to describe the basic Wolbachia distribution patterns that occur during the development of Wolbachia-infected, thelytokous Trichogramma dendrolimi, and T. pretiosum. We used fluorescence in situ hybridization (FISH) to investigate Wolbachia signal dynamics during early embryogenesis (from 30 to 120 min). Wolbachia titers and distributions from the embryo to adult stages of Trichogramma after early embryogenesis were detected by absolute quantitative polymerase chain reaction (AQ-PCR) and FISH. The symmetry ratios (SR) of the Wolbachia signals were calculated using the SR odds ratios in the anterior and posterior parts of the host. The SR was determined to describe Wolbachia tropism during early embryogenesis and various developmental stages of Trichogramma.<br><br>RESULTS: Wolbachia was concentrated in the posterior part of the embryo during early embryogenesis and the various developmental stages of both T. dendrolimi and T. pretiosum. Wolbachia density increased with the number of nuclei and the initial mitotic division frequency during early embryogenesis. The total Wolbachia titer increased with postembryogenesis development in both T. dendrolimi and T. pretiosum. However, the Wolbachia densities relative to body size were significantly lower at the adult and pupal stages than they were at the embryonic stage.<br><br>DISCUSSION: The present work revealed that posterior Wolbachia concentration during early host embryogenesis determined Wolbachia localization in adult wasps. By this mechanism, Wolbachia exhibits efficient vertical transmission across generations by depositing only female Wolbachia-infected offspring. The results of this study describe the dynamics of Wolbachia during the development of their Trichogramma host. The findings of this investigation helped clarify Wolbachia tropism in Trichogramma wasps.}, }
@article {pmid37417166, year = {2023}, author = {Tharsan, A and Sivabalakrishnan, K and Arthiyan, S and Eswaramohan, T and Raveendran, S and Ramasamy, R and Surendran, SN}, title = {Wolbachia infection is widespread in brackish and fresh water Aedes albopictus (Diptera: Culicidae) in the coastal Jaffna peninsula of northern Sri Lanka.}, journal = {Journal of vector borne diseases}, volume = {60}, number = {2}, pages = {172-178}, doi = {10.4103/0972-9062.361165}, pmid = {37417166}, issn = {0972-9062}, abstract = {BACKGROUND &amp; OBJECTIVES: Aedes albopictus and Aedes aegypti are important vectors of dengue and many other arboviral diseases in tropical and sub-tropical locations. Both vectors are tolerant of salinity in the dengue-endemic coastal Jaffna peninsula of northern Sri Lanka. Aedes albopictus pre-imaginal stages are found in field brackish water habitats of up to 14 parts per thousand (ppt, gL[-1]) salt in the Jaffna peninsula. Salinity-tolerance in Aedes is characterized by significant genetic and physiological changes. Infection with the wMel strain of the endosymbiont bacterium Wolbachia pipientis reduces dengue transmission in the field by Ae. aegypti, and the same approach is also being considered for Ae. albopictus. In this context, we investigated natural Wolbachia infections in brackish and fresh water field isolates of Ae. albopictus in the Jaffna district.<br><br>METHODS: Aedes albopictus collected as pre-imaginal stages using conventional ovitraps in the Jaffna peninsula and adjacent islands of the Jaffna district were screened by PCR utilizing strain-transcending primers for the presence of Wolbachia. Wolbachia strains were then further identified by PCR using strain-specific primers for the Wolbachia surface protein gene wsp. The Jaffna wsp sequences were compared by phylogenetic analysis with other wsp sequences available in Genbank.<br><br>RESULTS: Aedes albopictus were found to be widely infected with the wAlbA and wAlbB strains of Wolbachia in Jaffna. The partial wAlbB wsp surface protein gene sequence in Jaffna Ae. albopictus was identical to a corresponding sequence from South India but different from that in mainland Sri Lanka.<br><br>Widespread infection of salinity-tolerant Ae. albopictus with Wolbachia is a factor to be considered when developing Wolbachia-based dengue control in coastal areas like the Jaffna peninsula.}, }
@article {pmid37416893, year = {2023}, author = {Wenzel, M and Aquadro, CF}, title = {Wolbachia genetically interacts with the bag of marbles germline stem cell gene in male D. melanogaster.}, journal = {microPublication biology}, volume = {2023}, number = {}, pages = {}, pmid = {37416893}, issn = {2578-9430}, abstract = {The bacterial endosymbiont Wolbachia manipulates reproduction of its arthropod hosts to promote its own maternal vertical transmission. In female D. melanogaster , Wolbachia has been shown to genetically interact with three key reproductive genes (bag of marbles (bam) , Sex-lethal, and mei-P26) , as it rescues the reduced female fertility or fecundity phenotype seen in partial loss-of-function mutants of these genes . Here, we show that Wolbachia also partially rescues male fertility in D. melanogaster carrying a new, largely sterile bam allele when in a bam null genetic background. This finding shows that the molecular mechanism of Wolbachia 's influence on its hosts' reproduction involves interaction with genes in males as well as females, at least in D. melanogaster .}, }
@article {pmid37410021, year = {2023}, author = {Herrera, G and Vieira Lista, MC and Páez-Triana, L and Muro, A and López-Abán, J and Muñoz, M and Ramírez, JD}, title = {Examining the gut microbiota from several human-biting tick species in Northwestern Spain.}, journal = {Journal of medical entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jme/tjad084}, pmid = {37410021}, issn = {1938-2928}, support = {PI22/01721//ISC-III/ ; PI22/01721//ISC-III/ ; }, abstract = {Tick-borne diseases have increased significantly in Europe and Spain in recent years. One strategy explored for tick surveillance and control is the study of the microbiota. The focus is on understanding the relationships between pathogens and endosymbionts within the microbiota and how these relationships can alter these arthropods' vectorial capacity. Thus, it is pivotal to depict the bacterial communities composing the microbiota of ticks present in specific territories. This work aimed to describe the microbiota present in 29 adult individuals of 5 tick species collected from 4 provinces of Castilla y Leon in northwestern Spain from 2015 to 2022. DNA extraction and sequencing of the V4 hypervariable region of 16S-rRNA was performed on the tick samples, with subsequent analysis of diversity, taxonomic composition, and correlations between genera of microorganisms. There were no differences in the alpha diversity of microbiota by tick species, nor were compositional changes evident at the phylum level for microorganisms. However, interindividual differences at the microbial genus level allowed spatial differentiation of the 5 tick species included in the study. Correlation analyses showed complex interactions between different genera of microbiota members. These findings provide an initial insight into the composition of the gut microbiota of various tick species in northwestern Spain, which can contribute to establishing surveillance and control measures to reduce diseases such as rickettsiosis, Lyme disease, and Crimean-Congo hemorrhagic fever.}, }
@article {pmid37407813, year = {2023}, author = {Moger-Reischer, RZ and Glass, JI and Wise, KS and Sun, L and Bittencourt, DMC and Lehmkuhl, BK and Schoolmaster, DR and Lynch, M and Lennon, JT}, title = {Evolution of a minimal cell.}, journal = {Nature}, volume = {}, number = {}, pages = {}, pmid = {37407813}, issn = {1476-4687}, abstract = {Possessing only essential genes, a minimal cell can reveal mechanisms and processes that are critical for the persistence and stability of life[1,2]. Here we report on how an engineered minimal cell[3,4] contends with the forces of evolution compared with the Mycoplasma mycoides non-minimal cell from which it was synthetically derived. Mutation rates were the highest among all reported bacteria, but were not affected by genome minimization. Genome streamlining was costly, leading to a decrease in fitness of greater than 50%, but this deficit was regained during 2,000 generations of evolution. Despite selection acting on distinct genetic targets, increases in the maximum growth rate of the synthetic cells were comparable. Moreover, when performance was assessed by relative fitness, the minimal cell evolved 39% faster than the non-minimal cell. The only apparent constraint involved the evolution of cell size. The size of the non-minimal cell increased by 80%, whereas the minimal cell remained the same. This pattern reflected epistatic effects of mutations in ftsZ, which encodes a tubulin-homologue protein that regulates cell division and morphology[5,6]. Our findings demonstrate that natural selection can rapidly increase the fitness of one of the simplest autonomously growing organisms. Understanding how species with small genomes overcome evolutionary challenges provides critical insights into the persistence of host-associated endosymbionts, the stability of streamlined chassis for biotechnology and the targeted refinement of synthetically engineered cells[2,7-9].}, }
@article {pmid37392458, year = {2023}, author = {Deng, J and Bennett, GM and Franco, DC and Prus-Frankowska, M and Stroiński, A and Michalik, A and Łukasik, P}, title = {Genome comparison reveals inversions and alternative evolutionary history of nutritional endosymbionts in planthoppers (Hemiptera: Fulgoromorpha).}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evad120}, pmid = {37392458}, issn = {1759-6653}, abstract = {The evolutionary success of sap-feeding hemipteran insects in the suborder Auchenorrhyncha was enabled by nutritional contributions from their heritable endosymbiotic bacteria. However, the symbiont diversity, functions, and evolutionary origins in this large insect group have not been broadly characterized using genomic tools. In particular, the origins and relationships among ancient betaproteobacterial symbionts Vidania (in Fulgoromorpha) and Nasuia/Zinderia (in Cicadomorpha) are uncertain. Here, we characterized the genomes of Vidania and Sulcia from three Pyrops planthoppers (family Fulgoridae) to understand their metabolic functions and evolutionary histories. We find that, like in previously characterized planthoppers, these symbionts share nutritional responsibilities, with Vidania providing seven out of ten essential amino acids. Sulcia lineages across the Auchenorrhyncha have a highly conserved genome but with multiple independent rearrangements occurring in an early ancestor of Cicadomorpha or Fulgoromorpha and in a few succeeding lineages. Genomic synteny was also observed within each of the betaproteobacterial symbiont genera Nasuia, Zinderia, and Vidania, but not across them, which challenges the expectation of a shared ancestry for these symbionts. The further comparison of other biological traits strongly suggests an independent origin of Vidania early in the planthopper evolution and possibly of Nasuia and Zinderia in their respective host lineages. This hypothesis further links the potential acquisition of novel nutritional endosymbiont lineages with the emergence of auchenorrhynchan superfamilies.}, }
@article {pmid37391621, year = {2023}, author = {Yamada, N and Lepetit, B and Mann, DG and Sprecher, BN and Buck, JM and Bergmann, P and Kroth, PG and Bolton, JJ and Dąbek, P and Witkowski, A and Kim, SY and Trobajo, R}, title = {Prey preference in a kleptoplastic dinoflagellate is linked to photosynthetic performance.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {37391621}, issn = {1751-7370}, support = {YA577/2-1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; GBMF9360//Gordon and Betty Moore Foundation (Gordon E. and Betty I. Moore Foundation)/ ; }, abstract = {Dinoflagellates of the family Kryptoperidiniaceae, known as "dinotoms", possess diatom-derived endosymbionts and contain individuals at three successive evolutionary stages: a transiently maintained kleptoplastic stage; a stage containing multiple permanently maintained diatom endosymbionts; and a further permanent stage containing a single diatom endosymbiont. Kleptoplastic dinotoms were discovered only recently, in Durinskia capensis; until now it has not been investigated kleptoplastic behavior and the metabolic and genetic integration of host and prey. Here, we show D. capensis is able to use various diatom species as kleptoplastids and exhibits different photosynthetic capacities depending on the diatom species. This is in contrast with the prey diatoms in their free-living stage, as there are no differences in their photosynthetic capacities. Complete photosynthesis including both the light reactions and the Calvin cycle remain active only when D. capensis feeds on its habitual associate, the "essential" diatom Nitzschia captiva. The organelles of another edible diatom, N. inconspicua, are preserved intact after ingestion by D. capensis and expresses the psbC gene of the photosynthetic light reaction, while RuBisCO gene expression is lost. Our results indicate that edible but non-essential, "supplemental" diatoms are used by D. capensis for producing ATP and NADPH, but not for carbon fixation. D. capensis has established a species-specifically designed metabolic system allowing carbon fixation to be performed only by its essential diatoms. The ability of D. capensis to ingest supplemental diatoms as kleptoplastids may be a flexible ecological strategy, to use these diatoms as "emergency supplies" while no essential diatoms are available.}, }
@article {pmid37391552, year = {2023}, author = {Zając, Z and Obregon, D and Foucault-Simonin, A and Wu-Chuang, A and Moutailler, S and Galon, C and Kulisz, J and Woźniak, A and Bartosik, K and Cabezas-Cruz, A}, title = {Disparate dynamics of pathogen prevalence in Ixodes ricinus and Dermacentor reticulatus ticks occurring sympatrically in diverse habitats.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {10645}, pmid = {37391552}, issn = {2045-2322}, support = {205/2018//Programa Nacional de Becas de Postgrado en el Exterior "Don Carlos Antonio L&#xf3;pez"/ ; ANR-10-LABX-62-IBEID//Agence Nationale de la Recherche/ ; }, abstract = {Ixodes ricinus and Dermacentor reticulatus ticks are important reservoirs and vectors of pathogens. The aim of the present study was to investigate the dynamic of the prevalence and genetic diversity of microorganisms detected in these tick species collected from two ecologically diverse biotopes undergoing disparate long-term climate condition. High-throughput real time PCR confirmed high prevalence of microorganisms detected in sympatrically occurring ticks species. D. reticulatus specimens were the most often infected with Francisella-like endosymbiont (FLE) (up to 100.0%) and Rickettsia spp. (up to 91.7%), while in case of I. ricinus the prevalence of Borreliaceae spirochetes reached up to 25.0%. Moreover, pathogens belonging to genera of Bartonella, Anaplasma, Ehrlichia and Babesia were detected in both tick species regardless the biotope. On the other hand, Neoehrlichia mikurensis was conformed only in I. ricinus in the forest biotope, while genetic material of Theileria spp. was found only in D. reticulatus collected from the meadow. Our study confirmed significant impact of biotope type on prevalence of representatives of Borreliaceae and Rickettsiaceae families. The most common co-infection detected in D. reticulatus was Rickettsia spp. + FLE, while Borreliaceae + R. helvetica was the most common in I. ricinus. Additionally, we found significant genetic diversity of R. raoultii gltA gene across studied years, however such relationship was not observed in ticks from studied biotopes. Our results suggest that ecological type of biotope undergoing disparate long-term climate conditions have an impact on prevalence of tick-borne pathogens in adult D. reticulatus and I. ricinus.}, }
@article {pmid37389180, year = {2023}, author = {Gao, ZM and Xu, T and Chen, HG and Lu, R and Tao, J and Wang, HB and Qiu, JW and Wang, Y}, title = {Early genome erosion and internal phage-symbiont-host interaction in the endosymbionts of a cold-seep tubeworm.}, journal = {iScience}, volume = {26}, number = {7}, pages = {107033}, doi = {10.1016/j.isci.2023.107033}, pmid = {37389180}, issn = {2589-0042}, abstract = {Endosymbiosis with chemosynthetic Gammaproteobacteria is widely recognized as an adaptive mechanism of siboglinid tubeworms, yet evolution of these endosymbionts and their driving forces remain elusive. Here, we report a finished endosymbiont genome (HMS1) of the cold-seep tubeworm Sclerolinum annulatum. The HMS1 genome is small in size, with abundant prophages and transposable elements but lacking gene sets coding for denitrification, hydrogen oxidization, oxidative phosphorylation, vitamin biosynthesis, cell pH and/or sodium homeostasis, environmental sensing, and motility, indicative of early genome erosion and adaptive evolution toward obligate endosymbiosis. Unexpectedly, a prophage embedded in the HMS1 genome undergoes lytic cycle. Highly expressed ROS scavenger and LexA repressor genes indicate that the tubeworm host likely activates the lysogenic phage into lytic cycle through the SOS response to regulate endosymbiont population and harvest nutrients. Our findings indicate progressive evolution of Sclerolinum endosymbionts toward obligate endosymbiosis and expand the knowledge about phage-symbiont-host interaction in deep-sea tubeworms.}, }
@article {pmid37383020, year = {2023}, author = {Nieves-Morión, M and Camargo, S and Bardi, S and Ruiz, MT and Flores, E and Foster, RA}, title = {Heterologous expression of genes from a cyanobacterial endosymbiont highlights substrate exchanges with its diatom host.}, journal = {PNAS nexus}, volume = {2}, number = {6}, pages = {pgad194}, pmid = {37383020}, issn = {2752-6542}, abstract = {A few genera of diatoms are widespread and thrive in low-nutrient waters of the open ocean due to their close association with N2-fixing, filamentous heterocyst-forming cyanobacteria. In one of these symbioses, the symbiont, Richelia euintracellularis, has penetrated the cell envelope of the host, Hemiaulus hauckii, and lives inside the host cytoplasm. How the partners interact, including how the symbiont sustains high rates of N2 fixation, is unstudied. Since R. euintracellularis has evaded isolation, heterologous expression of genes in model laboratory organisms was performed to identify the function of proteins from the endosymbiont. Gene complementation of a cyanobacterial invertase mutant and expression of the protein in Escherichia coli showed that R. euintracellularis HH01 possesses a neutral invertase that splits sucrose producing glucose and fructose. Several solute-binding proteins (SBPs) of ABC transporters encoded in the genome of R. euintracellularis HH01 were expressed in E. coli, and their substrates were characterized. The selected SBPs directly linked the host as the source of several substrates, e.g. sugars (sucrose and galactose), amino acids (glutamate and phenylalanine), and a polyamine (spermidine), to support the cyanobacterial symbiont. Finally, transcripts of genes encoding the invertase and SBPs were consistently detected in wild populations of H. hauckii collected from multiple stations and depths in the western tropical North Atlantic. Our results support the idea that the diatom host provides the endosymbiotic cyanobacterium with organic carbon to fuel N2 fixation. This knowledge is key to understanding the physiology of the globally significant H. hauckii-R. euintracellularis symbiosis.}, }
@article {pmid37382438, year = {2023}, author = {Goffredi, SK and Panossian, B and Brzechffa, C and Field, N and King, C and Moggioli, G and Rouse, GW and Martín-Durán, JM and Henry, LM}, title = {A dynamic epibiont community associated with the bone-eating polychaete genus Osedax.}, journal = {mBio}, volume = {}, number = {}, pages = {e0314022}, doi = {10.1128/mbio.03140-22}, pmid = {37382438}, issn = {2150-7511}, abstract = {Osedax, the deep-sea annelid found at sunken whalefalls, is known to host Oceanospirillales bacterial endosymbionts intracellularly in specialized roots, which help it feed exclusively on vertebrate bones. Past studies, however, have also made mention of external bacteria on their trunks. During a 14-yr study, we reveal a dynamic, yet persistent, shift of Campylobacterales integrated into the epidermis of Osedax, which change over time as the whale carcass degrades on the sea floor. The Campylobacterales associated with seven species of Osedax, which comprise 67% of the bacterial community on the trunk, appear initially dominated by the genus Arcobacter (at early time points <24 mo), the Sulfurospirillum at intermediate stages (~50 mo), and the Sulfurimonas at later stages (>140 mo) of whale carcass decomposition. Metagenome analysis of the epibiont metabolic capabilities suggests potential for a transition from heterotrophy to autotrophy and differences in their capacity to metabolize oxygen, carbon, nitrogen, and sulfur. Compared to free-living relatives, the Osedax epibiont genomes were enriched in transposable elements, implicating genetic exchange on the host surface, and contained numerous secretions systems with eukaryotic-like protein (ELP) domains, suggesting a long evolutionary history with these enigmatic, yet widely distributed deep-sea worms. IMPORTANCE Symbiotic associations are widespread in nature and we can expect to find them in every type of ecological niche. In the last twenty years, the myriad of functions, interactions and species comprising microbe-host associations has fueled a surge of interest and appreciation for symbiosis. During this 14-year study, we reveal a dynamic population of bacterial epibionts, integrated into the epidermis of 7 species of a deep-sea worm group that feeds exclusively on the remains of marine mammals. The bacterial genomes provide clues of a long evolutionary history with these enigmatic worms. On the host surface, they exchange genes and appear to undergo ecological succession, as the whale carcass habitat degrades over time, similar to what is observed for some free-living communities. These, and other annelid worms are important keystone species for diverse deep-sea environments, yet the role of attached external bacteria in supporting host health has received relatively little attention.}, }
@article {pmid37376640, year = {2023}, author = {Esmael, A and Agarkova, IV and Dunigan, DD and Zhou, Y and Van Etten, JL}, title = {Viral DNA Accumulation Regulates Replication Efficiency of Chlorovirus OSy-NE5 in Two Closely Related Chlorella variabilis Strains.}, journal = {Viruses}, volume = {15}, number = {6}, pages = {}, doi = {10.3390/v15061341}, pmid = {37376640}, issn = {1999-4915}, support = {1736030//NSF-EPSCoR grant/ ; }, abstract = {Many chloroviruses replicate in Chlorella variabilis algal strains that are ex-endosymbionts isolated from the protozoan Paramecium bursaria, including the NC64A and Syngen 2-3 strains. We noticed that indigenous water samples produced a higher number of plaque-forming viruses on C. variabilis Syngen 2-3 lawns than on C. variabilis NC64A lawns. These observed differences led to the discovery of viruses that replicate exclusively in Syngen 2-3 cells, named Only Syngen (OSy) viruses. Here, we demonstrate that OSy viruses initiate infection in the restricted host NC64A by synthesizing some early virus gene products and that approximately 20% of the cells produce a small number of empty virus capsids. However, the infected cells did not produce infectious viruses because the cells were unable to replicate the viral genome. This is interesting because all previous attempts to isolate host cells resistant to chlorovirus infection were due to changes in the host receptor for the virus.}, }
@article {pmid37372055, year = {2023}, author = {Gheibzadeh, MS and Manyumwa, CV and Tastan Bishop, &#xd6; and Shahbani Zahiri, H and Parkkila, S and Zolfaghari Emameh, R}, title = {Genome Study of α-, β-, and γ-Carbonic Anhydrases from the Thermophilic Microbiome of Marine Hydrothermal Vent Ecosystems.}, journal = {Biology}, volume = {12}, number = {6}, pages = {}, doi = {10.3390/biology12060770}, pmid = {37372055}, issn = {2079-7737}, support = {737//National Institute of Genetic Engineering and Biotechnology/ ; M/75137//Ministry of Science, Research and Technology/ ; 111212//National Research Foundation/ ; }, abstract = {Carbonic anhydrases (CAs) are metalloenzymes that can help organisms survive in hydrothermal vents by hydrating carbon dioxide (CO2). In this study, we focus on alpha (α), beta (β), and gamma (γ) CAs, which are present in the thermophilic microbiome of marine hydrothermal vents. The coding genes of these enzymes can be transferred between hydrothermal-vent organisms via horizontal gene transfer (HGT), which is an important tool in natural biodiversity. We performed big data mining and bioinformatics studies on α-, β-, and γ-CA coding genes from the thermophilic microbiome of marine hydrothermal vents. The results showed a reasonable association between thermostable α-, β-, and γ-CAs in the microbial population of the hydrothermal vents. This relationship could be due to HGT. We found evidence of HGT of α- and β-CAs between Cycloclasticus sp., a symbiont of Bathymodiolus heckerae, and an endosymbiont of Riftia pachyptila via Integrons. Conversely, HGT of β-CA genes from the endosymbiont Tevnia jerichonana to the endosymbiont Riftia pachyptila was detected. In addition, Hydrogenovibrio crunogenus SP-41 contains a β-CA gene on genomic islands (GIs). This gene can be transferred by HGT to Hydrogenovibrio sp. MA2-6, a methanotrophic endosymbiont of Bathymodiolus azoricus, and a methanotrophic endosymbiont of Bathymodiolus puteoserpentis. The endosymbiont of R. pachyptila has a γ-CA gene in the genome. If α- and β-CA coding genes have been derived from other microorganisms, such as endosymbionts of T. jerichonana and Cycloclasticus sp. as the endosymbiont of B. heckerae, through HGT, the theory of the necessity of thermostable CA enzymes for survival in the extreme ecosystem of hydrothermal vents is suggested and helps the conservation of microbiome natural diversity in hydrothermal vents. These harsh ecosystems, with their integral players, such as HGT and endosymbionts, significantly impact the enrichment of life on Earth and the carbon cycle in the ocean.}, }
@article {pmid37367660, year = {2023}, author = {Sikorskaya, TV}, title = {Coral Lipidome: Molecular Species of Phospholipids, Glycolipids, Betaine Lipids, and Sphingophosphonolipids.}, journal = {Marine drugs}, volume = {21}, number = {6}, pages = {}, doi = {10.3390/md21060335}, pmid = {37367660}, issn = {1660-3397}, abstract = {Coral reefs are the most biodiversity-rich ecosystems in the world's oceans. Coral establishes complex interactions with various microorganisms that constitute an important part of the coral holobiont. The best-known coral endosymbionts are Symbiodiniaceae dinoflagellates. Each member of the coral microbiome contributes to its total lipidome, which integrates many molecular species. The present study summarizes available information on the molecular species of the plasma membrane lipids of the coral host and its dinoflagellates (phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), ceramideaminoethylphosphonate, and diacylglyceryl-3-O-carboxyhydroxymethylcholine), and the thylakoid membrane lipids of dinoflagellates (phosphatidylglycerol (PG) and glycolipids). Alkyl chains of PC and PE molecular species differ between tropical and cold-water coral species, and features of their acyl chains depend on the coral's taxonomic position. PS and PI structural features are associated with the presence of an exoskeleton in the corals. The dinoflagellate thermosensitivity affects the profiles of PG and glycolipid molecular species, which can be modified by the coral host. Coral microbiome members, such as bacteria and fungi, can also be the source of the alkyl and acyl chains of coral membrane lipids. The lipidomics approach, providing broader and more detailed information about coral lipid composition, opens up new opportunities in the study of biochemistry and ecology of corals.}, }
@article {pmid37367356, year = {2023}, author = {Bazukyan, I and Georgieva-Miteva, D and Velikova, T and Dimov, SG}, title = {In Silico Probiogenomic Characterization of Lactobacillus delbrueckii subsp. lactis A4 Strain Isolated from an Armenian Honeybee Gut.}, journal = {Insects}, volume = {14}, number = {6}, pages = {}, doi = {10.3390/insects14060540}, pmid = {37367356}, issn = {2075-4450}, support = {21T-2I019//Science Committee of the Republic of Armenia/ ; 2022//Yerevan State University in the frames of inner research projects/ ; BG-RRP-2.004-0008-C01//European Union-NextGenerationEU, through the National Recovery and Resilience Plan of the Republic of Bulgaria/ ; }, abstract = {A Lactobacillus delbrueckii ssp. lactis strain named A4, isolated from the gut of an Armenian honeybee, was subjected to a probiogenomic characterization because of its unusual origin. A whole-genome sequencing was performed, and the bioinformatic analysis of its genome revealed a reduction in the genome size and the number of the genes-a process typical for the adaptation to endosymbiotic conditions. Further analysis of the genome revealed that Lactobacillus delbrueckii ssp. lactis strain named A4 could play the role of a probiotic endosymbiont because of the presence of intact genetic sequences determining antioxidant properties, exopolysaccharides synthesis, adhesion properties, and biofilm formation, as well as an antagonistic activity against some pathogens which is not due to pH or bacteriocins production. Additionally, the genomic analysis revealed significant potential for stress tolerance, such as extreme pH, osmotic stress, and high temperature. To our knowledge, this is the first report of a potentially endosymbiotic Lactobacillus delbrueckii ssp. lactis strain adapted to and playing beneficial roles for its host.}, }
@article {pmid37364116, year = {2023}, author = {Macorano, L and Binny, TM and Spiegl, T and Klimenko, V and Singer, A and Oberleitner, L and Applegate, V and Seyffert, S and Stefanski, A and Gremer, L and Gertzen, CGW and Höppner, A and Smits, SHJ and Nowack, ECM}, title = {DNA-binding and protein structure of nuclear factors likely acting in genetic information processing in the Paulinella chromatophore.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {27}, pages = {e2221595120}, doi = {10.1073/pnas.2221595120}, pmid = {37364116}, issn = {1091-6490}, support = {CRC1208 project B09//Deutsche Forschungsgemeinschaft (DFG)/ ; NO 1090/1-1//Deutsche Forschungsgemeinschaft (DFG)/ ; 417919780//Deutsche Forschungsgemeinschaft (DFG)/ ; INST 208/740-1 FUGG//Deutsche Forschungsgemeinschaft (DFG)/ ; }, abstract = {The chromatophores in Paulinella are evolutionary-early-stage photosynthetic organelles. Biological processes in chromatophores depend on a combination of chromatophore and nucleus-encoded proteins. Interestingly, besides proteins carrying chromatophore-targeting signals, a large arsenal of short chromatophore-targeted proteins (sCTPs; <90 amino acids) without recognizable targeting signals were found in chromatophores. This situation resembles endosymbionts in plants and insects that are manipulated by host-derived antimicrobial peptides. Previously, we identified an expanded family of sCTPs of unknown function, named here "DNA-binding (DB)-sCTPs". DB-sCTPs contain a ~45 amino acid motif that is conserved in some bacterial proteins with predicted functions in DNA processing. Here, we explored antimicrobial activity, DNA-binding capacity, and structures of three purified recombinant DB-sCTPs. All three proteins exhibited antimicrobial activity against bacteria involving membrane permeabilization, and bound to bacterial lipids in vitro. A combination of in vitro assays demonstrated binding of recombinant DB-sCTPs to chromatophore-derived genomic DNA sequences with an affinity in the low nM range. Additionally, we report the 1.2 Å crystal structure of one DB-sCTP. In silico docking studies suggest that helix α2 inserts into the DNA major grove and the exposed residues, that are highly variable between different DB-sCTPs, confer interaction with the DNA bases. Identification of photosystem II subunit CP43 as a potential interaction partner of one DB-sCTP, suggests DB-sCTPs to be involved in more complex regulatory mechanisms. We hypothesize that membrane binding of DB-sCTPs is related to their import into chromatophores. Once inside, they interact with the chromatophore genome potentially providing nuclear control over genetic information processing.}, }
@article {pmid37363264, year = {2023}, author = {Gashururu, RS and Maingi, N and Githigia, SM and Getange, DO and Ntivuguruzwa, JB and Habimana, R and Cecchi, G and Gashumba, J and Bargul, JL and Masiga, DK}, title = {Trypanosomes infection, endosymbionts, and host preferences in tsetse flies (Glossina spp.) collected from Akagera park region, Rwanda: A correlational xenomonitoring study.}, journal = {One health (Amsterdam, Netherlands)}, volume = {16}, number = {}, pages = {100550}, doi = {10.1016/j.onehlt.2023.100550}, pmid = {37363264}, issn = {2352-7714}, abstract = {Akagera National Park and its surroundings are home to tsetse flies and a number of their mammalian hosts in Rwanda. A One-health approach is being used in the control and surveillance of both animal and human trypanosomosis in Rwanda. Determination of the infection level in tsetse flies, species of trypanosomes circulating in vectors, the source of tsetse blood meal and endosymbionts is crucial in understanding the epidemiology of the disease in animals and humans in the region. Tsetse flies (n = 1101), comprising Glossina pallidipes (n = 771) and Glossina morsitans centralis (n = 330) were collected from Akagera park and surrounding areas between May 2018 and June 2019. The flies were screened for trypanosomes, vertebrate host DNA to identify sources of blood meal, and endosymbionts by PCR - High Resolution Melting analysis and amplicon sequencing. The feeding frequency and the feeding indices (selection index - W) were calculated to identify the preferred hosts. An overall trypanosome infection rate of 13.9% in the fly's Head and Proboscis (HP) and 24.3% in the Thorax and Abdomen (TA) were found. Eight trypanosome species were identified in the tsetse fly HP and TA, namely: Trypanosoma (T.) brucei brucei, T. congolense Kilifi, T. congolense savannah, T. vivax, T. simiae, T. evansi, T. godfreyi, T. grayi and T. theileri. We found no evidence of human-infective T. brucei rhodesiense. We also identified eighteen species of vertebrate hosts that tsetse flies fed on, and the most frequent one was the buffalo (Syncerus caffer) (36.5%). The frequently detected host by selection index was the rhinoceros (Diceros bicornis) (W = 16.2). Most trypanosome infections in tsetse flies were associated with the buffalo blood meal. The prevalence of tsetse endosymbionts Sodalis and Wolbachia was 2.8% and 4.8%, respectively. No Spiroplasma and Salivary Gland Hypertrophy Virus were detected. These findings implicate the buffaloes as the important reservoirs of tsetse-transmitted trypanosomes in the area. This contributes to predicting the main cryptic reservoirs and therefore guiding the effective control of the disease. The study findings provide the key scientific information that supports the current One Health collaboration in the control and surveillance of tsetse-transmitted trypanosomosis in Rwanda.}, }
@article {pmid37362913, year = {2023}, author = {Beckmann, J and Gillespie, J and Tauritz, D}, title = {Modeling emergence of Wolbachia toxin-antidote protein functions with an evolutionary algorithm.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1116766}, doi = {10.3389/fmicb.2023.1116766}, pmid = {37362913}, issn = {1664-302X}, abstract = {Evolutionary algorithms (EAs) simulate Darwinian evolution and adeptly mimic natural evolution. Most EA applications in biology encode high levels of abstraction in top-down population ecology models. In contrast, our research merges protein alignment algorithms from bioinformatics into codon based EAs that simulate molecular protein string evolution from the bottom up. We apply our EA to reconcile a problem in the field of Wolbachia induced cytoplasmic incompatibility (CI). Wolbachia is a microbial endosymbiont that lives inside insect cells. CI is conditional insect sterility that operates as a toxin antidote (TA) system. Although, CI exhibits complex phenotypes not fully explained under a single discrete model. We instantiate in-silico genes that control CI, CI factors (cifs), as strings within the EA chromosome. We monitor the evolution of their enzymatic activity, binding, and cellular localization by applying selective pressure on their primary amino acid strings. Our model helps rationalize why two distinct mechanisms of CI induction might coexist in nature. We find that nuclear localization signals (NLS) and Type IV secretion system signals (T4SS) are of low complexity and evolve fast, whereas binding interactions have intermediate complexity, and enzymatic activity is the most complex. Our model predicts that as ancestral TA systems evolve into eukaryotic CI systems, the placement of NLS or T4SS signals can stochastically vary, imparting effects that might impact CI induction mechanics. Our model highlights how preconditions and sequence length can bias evolution of cifs toward one mechanism or another.}, }
@article {pmid37347285, year = {2023}, author = {Ehlers, LP and Slaviero, M and De Lorenzo, C and Fagundes-Moreira, R and de Souza, VK and Perles, L and Baggio-Souza, V and Bezerra-Santos, MA and Modrý, D and Benovics, M and Panziera, W and Driemeier, D and Pavarini, SP and Soares, JF and Otranto, D and Sonne, L}, title = {Pathological findings associated with Dipetalonema spp. (Spirurida, Onchocercidae) infection in two species of Neotropical monkeys from Brazil.}, journal = {Parasitology research}, volume = {}, number = {}, pages = {}, pmid = {37347285}, issn = {1432-1955}, abstract = {Among vector-borne helminths, filarioids of the genus Dipetalonema (Spirurida: Onchocercidae) localize in several tissues and body cavities of several animal species, causing mild to moderate lesions. The pathological findings associated with Dipetalonema spp. infection in Neotropical monkeys from southern Brazil are herein described, along with a fatal case due to filarial polyserositis and entrapment of an intestinal segment. At necropsy, nematodes were observed in abdominal and thoracic cavities, or in the pericardium of 37 (31.3%) out of the 118 individuals examined (i.e., 35 Alouatta guariba clamitans and two Sapajus nigritus). In addition, at histology, 27.0% of positive animals presented microfilarie (inside blood vessels of lung, spleen, liver, and brain) and 8.1% presented adult nematodes in the heart, lung, and liver. In two cases, cross-sections of filarioids were associated with areas of epicardial thickening with intense fibrosis and pyogranulomatous inflammation in the brain, heart, liver, lungs, or spleen. The DNA fragment was amplify using the cox1 gene, sequenced and analyzed to identify the nematode species collected; presence of Wolbachia was assessed in the filarioids using the 16S rRNA gene. At BLAST analysis of the cox1 gene, 10 sequences showed 91.7% nucleotide identity with Dipetalonema gracile, and two with D. gracile (98.5%) and Dipetalonema graciliformis (98.3%). Phylogenetic analyses clustered sequences of the cox1 obtained in this study in two clades corresponding with the host species. Wolbachia sp. endosymbiont was detected in four samples. Data herein reported provide a description of pathological lesions associated with the infection by Dipetalonema spp., suggesting that they may cause disease in Neotropical monkeys. In addition, a better understanding of diversity and biology of Dipetalonema spp. in South America is needed to assess the impact they may cause in native non-human primates from Brazil.}, }
@article {pmid37345405, year = {2023}, author = {Gao, YF and Ren, YJ and Chen, JC and Cao, LJ and Qiao, GH and Zong, SX and Hoffmann, AA and Wei, SJ and Yang, Q}, title = {Effects of fungicides on fitness and Buchnera endosymbiont density in Aphis gossypii.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7625}, pmid = {37345405}, issn = {1526-4998}, abstract = {BACKGROUND: Several agricultural fungicides are known to affect insect pests directly and these effects may be transgenerational and mediated through impacts on endosymbionts, providing opportunities for pest control. The cotton aphid Aphis gossypii is a polyphagous pest that can cause large crop yield losses. Here we tested the effects of three fungicides, pyraclostrobin, trifloxystrobin, and chlorothalonil, on the fitness and Buchnera endosymbiont of A. gossypii.<br><br>RESULTS: The formulations of trifloxystrobin and pyraclostrobin, and the active ingredient of pyraclostrobin, produced dose-dependent mortality to A. gossypii, while there was no dose-dependent mortality for chlorothalonil. The formulations of trifloxystrobin and pyraclostrobin significantly reduced the lifespan and fecundity of A. gossypii, and increased the density of Buchnera in the parental generation but not the (unexposed) F1 . When the active ingredient of pyraclostrobin was tested, the lifespan of the F0 generation was also reduced but not the density of Buchnera, indicating that non-insecticidal chemicals in the fungicide formulation may affect density of the endosymbiont of A. gossypii. There was no transgenerational effect of active ingredient of pyraclostrobin on the lifespan and Buchnera of (unexposed) F1 .<br><br>CONCLUSIONS: Our results suggest that formulations of two strobilurin fungicides have immediate impacts on the fitness of A. gossypii, and chemicals in the formulation impact the density of the primary Buchnera endosymbiont. Our study highlights the potential effects of non-insecticidal chemicals of fungicides on aphid pests and their primary endosymbionts but direct connections between fitness and Buchnera densities remain unclear. This article is protected by copyright. All rights reserved.}, }
@article {pmid37339742, year = {2023}, author = {Arora, J and Buček, A and Hellemans, S and Beránková, T and Arias, JR and Fisher, BL and Clitheroe, C and Brune, A and Kinjo, Y and Šobotník, J and Bourguignon, T}, title = {Evidence of cospeciation between termites and their gut bacteria on a geological time scale.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {2001}, pages = {20230619}, doi = {10.1098/rspb.2023.0619}, pmid = {37339742}, issn = {1471-2954}, abstract = {Termites host diverse communities of gut microbes, including many bacterial lineages only found in this habitat. The bacteria endemic to termite guts are transmitted via two routes: a vertical route from parent colonies to daughter colonies and a horizontal route between colonies sometimes belonging to different termite species. The relative importance of both transmission routes in shaping the gut microbiota of termites remains unknown. Using bacterial marker genes derived from the gut metagenomes of 197 termites and one Cryptocercus cockroach, we show that bacteria endemic to termite guts are mostly transferred vertically. We identified 18 lineages of gut bacteria showing cophylogenetic patterns with termites over tens of millions of years. Horizontal transfer rates estimated for 16 bacterial lineages were within the range of those estimated for 15 mitochondrial genes, suggesting that horizontal transfers are uncommon and vertical transfers are the dominant transmission route in these lineages. Some of these associations probably date back more than 150 million years and are an order of magnitude older than the cophylogenetic patterns between mammalian hosts and their gut bacteria. Our results suggest that termites have cospeciated with their gut bacteria since first appearing in the geological record.}, }
@article {pmid37323942, year = {2023}, author = {Awori, RM and Waturu, CN and Pidot, SJ and Amugune, NO and Bode, HB}, title = {Draft genomes, phylogenomic reconstruction and comparative genome analysis of three Xenorhabdus strains isolated from soil-dwelling nematodes in Kenya.}, journal = {Access microbiology}, volume = {5}, number = {5}, pages = {}, pmid = {37323942}, issn = {2516-8290}, abstract = {As a proven source of potent and selective antimicrobials, Xenorhabdus bacteria are important to an age plagued with difficult-to-treat microbial infections. Yet, only 27 species have been described to date. In this study, a novel Xenorhabdus species was discovered through genomic studies on three isolates from Kenyan soils. Soils in Western Kenya were surveyed for steinernematids and Steinernema isolates VH1 and BG5 were recovered from red volcanic loam soils from cultivated land in Vihiga and clay soils from riverine land in Bungoma respectively. From the two nematode isolates, Xenorhabdus sp. BG5 and Xenorhabdus sp. VH1 were isolated. The genomes of these two, plus that of X. griffiniae XN45 - this was previously isolated from Steinernema sp. scarpo that also originated from Kenyan soils - were sequenced and assembled. Nascent genome assemblies of the three isolates were of good quality with over 70 % of their proteome having known functions. These three isolates formed the X. griffiniae clade in a phylogenomic reconstruction of the genus. Their species were delineated using three overall genome relatedness indices: an unnamed species of the genus, Xenorhabdus sp. BG5, X. griffiniae VH1 and X. griffiniae XN45. A pangenome analysis of this clade revealed that over 70 % of species-specific genes encoded unknown functions. Transposases were linked to genomic islands in Xenorhabdus sp. BG5. Thus, overall genome-related indices sufficiently delineated species of two new Xenorhabdus isolates from Kenya, both of which were closely related to X. griffiniae . The functions encoded by most species-specific genes in the X. griffiniae clade remain unknown.}, }
@article {pmid37323901, year = {2023}, author = {Hyams, Y and Rubin-Blum, M and Rosner, A and Brodsky, L and Rinkevich, Y and Rinkevich, B}, title = {Physiological changes during torpor favor association with Endozoicomonas endosymbionts in the urochordate Botrylloides leachii.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1072053}, pmid = {37323901}, issn = {1664-302X}, abstract = {Environmental perturbations evoke down-regulation of metabolism in some multicellular organisms, leading to dormancy, or torpor. Colonies of the urochordate Botrylloides leachii enter torpor in response to changes in seawater temperature and may survive for months as small vasculature remnants that lack feeding and reproductive organs but possess torpor-specific microbiota. Upon returning to milder conditions, the colonies rapidly restore their original morphology, cytology and functionality while harboring re-occurring microbiota, a phenomenon that has not been described in detail to date. Here we investigated the stability of B. leachii microbiome and its functionality in active and dormant colonies, using microscopy, qPCR, in situ hybridization, genomics and transcriptomics. A novel lineage of Endozoicomonas, proposed here as Candidatus Endozoicomonas endoleachii, was dominant in torpor animals (53-79% read abundance), and potentially occupied specific hemocytes found only in torpid animals. Functional analysis of the metagenome-assembled genome and genome-targeted transcriptomics revealed that Endozoicomonas can use various cellular substrates, like amino acids and sugars, potentially producing biotin and thiamine, but also expressing various features involved in autocatalytic symbiosis. Our study suggests that the microbiome can be linked to the metabolic and physiological states of the host, B. leachii, introducing a model organism for the study of symbioses during drastic physiological changes, such as torpor.}, }
@article {pmid37317290, year = {2023}, author = {Massé, A and Detang, J and Duval, C and Duperron, S and Woo, AC and Domart-Coulon, I}, title = {Bacterial Microbiota of Ostreobium, the Coral-Isolated Chlorophyte Ectosymbiont, at Contrasted Salinities.}, journal = {Microorganisms}, volume = {11}, number = {5}, pages = {}, doi = {10.3390/microorganisms11051318}, pmid = {37317290}, issn = {2076-2607}, abstract = {Microscopic filaments of the siphonous green algae Ostreobium (Ulvophyceae, Bryopsidales) colonize and dissolve the calcium carbonate skeletons of coral colonies in reefs of contrasted salinities. Here, we analyzed their bacterial community's composition and plasticity in response to salinity. Multiple cultures of Pocillopora coral-isolated Ostreobium strains from two distinct rbcL lineages representative of IndoPacific environmental phylotypes were pre-acclimatized (>9 months) to three ecologically relevant reef salinities: 32.9, 35.1, and 40.2 psu. Bacterial phylotypes were visualized for the first time at filament scale by CARD-FISH in algal tissue sections, within siphons, at their surface or in their mucilage. Ostreobium-associated microbiota, characterized by bacterial 16S rDNA metabarcoding of cultured thalli and their corresponding supernatants, were structured by host genotype (Ostreobium strain lineage), with dominant Kiloniellaceae or Rhodospirillaceae (Alphaproteobacteria, Rhodospirillales) depending on Ostreobium lineage, and shifted Rhizobiales' abundances in response to the salinity increase. A small core microbiota composed of seven ASVs (~1.5% of thalli ASVs, 19-36% cumulated proportions) was persistent across three salinities in both genotypes, with putative intracellular Amoebophilaceae and Rickettsiales_AB1, as well as Hyphomonadaceae and Rhodospirillaceae also detected within environmental (Ostreobium-colonized) Pocillopora coral skeletons. This novel knowledge on the taxonomic diversity of Ostreobium bacteria paves the way to functional interaction studies within the coral holobiont.}, }
@article {pmid37317070, year = {2023}, author = {Aspinwall, JA and Jarvis, SM and Noh, SM and Brayton, KA}, title = {The Effect of Rickettsia bellii on Anaplasma marginale Infection in Dermacentor andersoni Cell Culture.}, journal = {Microorganisms}, volume = {11}, number = {5}, pages = {}, doi = {10.3390/microorganisms11051096}, pmid = {37317070}, issn = {2076-2607}, abstract = {Anaplasma marginale is a tick-borne pathogen that causes bovine anaplasmosis, which affects cattle around the world. Despite its broad prevalence and severe economic impacts, limited treatments exist for this disease. Our lab previously reported that a high proportion of Rickettsia bellii, a tick endosymbiont, in the microbiome of a population of Dermacentor andersoni ticks negatively impacts the ticks' ability to acquire A. marginale. To better understand this correlation, we used mixed infection of A. marginale and R. bellii in D. andersoni cell culture. We assessed the impacts of different amounts of R. bellii in coinfections, as well as established R. bellii infection, on the ability of A. marginale to establish an infection and grow in D. andersoni cells. From these experiments, we conclude that A. marginale is less able to establish an infection in the presence of R. bellii and that an established R. bellii infection inhibits A. marginale replication. This interaction highlights the importance of the microbiome in preventing tick vector competence and may lead to the development of a biological or mechanistic control for A. marginale transmission by the tick.}, }
@article {pmid37303533, year = {2023}, author = {Rodríguez, L and Peñalver, M and Casino, P and García-Del Portillo, F}, title = {Evolutionary analysis and structure modelling of the Rcs-repressor IgaA unveil a functional role of two cytoplasmic small β-barrel (SBB) domains.}, journal = {Heliyon}, volume = {9}, number = {6}, pages = {e16661}, pmid = {37303533}, issn = {2405-8440}, abstract = {The Rcs sensor system, comprising the RcsB/RcsC/RcsD and RcsF proteins, is used by bacteria of the order Enterobacterales to withstand envelope damage. In non-stress conditions, Rcs is repressed by IgaA, a membrane protein with three cytoplasmic regions (cyt-1, cyt-2 and cyt-3). How the Rcs-IgaA axis evolved within Enterobacterales has not been yet explored. Here, we report phylogenetic data supporting co-evolution of IgaA with RcsC/RcsD. Functional exchange assays showed that IgaA from Shigella and Dickeya, but not from Yersinia or the endosymbionts Photorhabdus and Sodalis, repress the Rcs system of Salmonella. IgaA from Dickeya, however, repress only partially the Rcs system despite being produced at high levels in the complementation assay. The modelled structures of these IgaA variants uncovered one periplasmic and two cytoplasmic conserved β-rich architectures forming partially closed small β-barrel (SBB) domains. Conserved residues map in a connector linking cytoplasmic SSB-1 and SBB-2 domains (E180-R265); a region of cyt-1 facing cyt-2 (R188-E194-D309 and T191-H326); and between cyt-2 and cyt-3 (H293-E328-R686). These structures validated early in vivo studies in Salmonella that assigned a role in function to R188, T191 and G262, and in addition revealed a previously unnoticed "hybrid" SBB-2 domain to which cyt-1 and cyt-2 contribute. IgaA variants not functional or partially functional in Salmonella lack H192-P249 and R255-D313 interactions. Among these variants, only IgaA from Dickeya conserves the helix α6 in SSB-1 that is present in IgaA from Salmonella and Shigella. RcsF and RcsD, which interact directly with IgaA, failed to show structural features linked to specific IgaA variants. Altogether, our data provide new insights into IgaA by mapping residues selected differently during evolution and involved in function. Our data also infer contrasting lifestyles of Enterobacterales bacteria as source of variability in the IgaA-RcsD/IgaA-RcsF interactions.}, }
@article {pmid37301202, year = {2023}, author = {Richter, I and Wein, P and Uzum, Z and Stanley, CE and Krabbe, J and Molloy, EM and Moebius, N and Ferling, I and Hillmann, F and Hertweck, C}, title = {Transcription activator-like effector protects bacterial endosymbionts from entrapment within fungal hyphae.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2023.05.028}, pmid = {37301202}, issn = {1879-0445}, abstract = {As an endosymbiont of the ecologically and medically relevant fungus Rhizopus microsporus, the toxin-producing bacterium Mycetohabitans rhizoxinica faces myriad challenges, such as evading the host's defense mechanisms. However, the bacterial effector(s) that facilitate the remarkable ability of M. rhizoxinica to freely migrate within fungal hyphae have thus far remained unknown. Here, we show that a transcription activator-like (TAL) effector released by endobacteria is an essential symbiosis factor. By combining microfluidics with fluorescence microscopy, we observed enrichment of TAL-deficient M. rhizoxinica in side hyphae. High-resolution live imaging showed the formation of septa at the base of infected hyphae, leading to the entrapment of endobacteria. Using a LIVE/DEAD stain, we demonstrate that the intracellular survival of trapped TAL-deficient bacteria is significantly reduced compared with wild-type M. rhizoxinica, indicative of a protective host response in the absence of TAL proteins. Subversion of host defense in TAL-competent endobacteria represents an unprecedented function of TAL effectors. Our data illustrate an unusual survival strategy of endosymbionts in the host and provide deeper insights into the dynamic interactions between bacteria and eukaryotes.}, }
@article {pmid37298563, year = {2023}, author = {Fiutek, N and Couger, MB and Pirro, S and Roy, SW and de la Torre, JR and Connor, EF}, title = {Genomic Assessment of the Contribution of the Wolbachia Endosymbiont of Eurosta solidaginis to Gall Induction.}, journal = {International journal of molecular sciences}, volume = {24}, number = {11}, pages = {}, doi = {10.3390/ijms24119613}, pmid = {37298563}, issn = {1422-0067}, support = {IRGEN_RG_2021-1345/IRGEN/IRGEN/United States ; }, abstract = {We explored the genome of the Wolbachia strain, wEsol, symbiotic with the plant-gall-inducing fly Eurosta solidaginis with the goal of determining if wEsol contributes to gall induction by its insect host. Gall induction by insects has been hypothesized to involve the secretion of the phytohormones cytokinin and auxin and/or proteinaceous effectors to stimulate cell division and growth in the host plant. We sequenced the metagenome of E. solidaginis and wEsol and assembled and annotated the genome of wEsol. The wEsol genome has an assembled length of 1.66 Mbp and contains 1878 protein-coding genes. The wEsol genome is replete with proteins encoded by mobile genetic elements and shows evidence of seven different prophages. We also detected evidence of multiple small insertions of wEsol genes into the genome of the host insect. Our characterization of the genome of wEsol indicates that it is compromised in the synthesis of dimethylallyl pyrophosphate (DMAPP) and S-adenosyl L-methionine (SAM), which are precursors required for the synthesis of cytokinins and methylthiolated cytokinins. wEsol is also incapable of synthesizing tryptophan, and its genome contains no enzymes in any of the known pathways for the synthesis of indole-3-acetic acid (IAA) from tryptophan. wEsol must steal DMAPP and L-methionine from its host and therefore is unlikely to provide cytokinin and auxin to its insect host for use in gall induction. Furthermore, in spite of its large repertoire of predicted Type IV secreted effector proteins, these effectors are more likely to contribute to the acquisition of nutrients and the manipulation of the host's cellular environment to contribute to growth and reproduction of wEsol than to aid E. solidaginis in manipulating its host plant. Combined with earlier work that shows that wEsol is absent from the salivary glands of E. solidaginis, our results suggest that wEsol does not contribute to gall induction by its host.}, }
@article {pmid37298356, year = {2023}, author = {Mioduchowska, M and Konecka, E and Gołdyn, B and Pinceel, T and Brendonck, L and Lukić, D and Kaczmarek, &#x141; and Namiotko, T and Zając, K and Zając, T and Jastrzębski, JP and Bartoszek, K}, title = {Playing Peekaboo with a Master Manipulator: Metagenetic Detection and Phylogenetic Analysis of Wolbachia Supergroups in Freshwater Invertebrates.}, journal = {International journal of molecular sciences}, volume = {24}, number = {11}, pages = {}, doi = {10.3390/ijms24119400}, pmid = {37298356}, issn = {1422-0067}, abstract = {The infamous "master manipulators"-intracellular bacteria of the genus Wolbachia-infect a broad range of phylogenetically diverse invertebrate hosts in terrestrial ecosystems. Wolbachia has an important impact on the ecology and evolution of their host with documented effects including induced parthenogenesis, male killing, feminization, and cytoplasmic incompatibility. Nonetheless, data on Wolbachia infections in non-terrestrial invertebrates are scarce. Sampling bias and methodological limitations are some of the reasons limiting the detection of these bacteria in aquatic organisms. In this study, we present a new metagenetic method for detecting the co-occurrence of different Wolbachia strains in freshwater invertebrates host species, i.e., freshwater Arthropoda (Crustacea), Mollusca (Bivalvia), and water bears (Tardigrada) by applying NGS primers designed by us and a Python script that allows the identification of Wolbachia target sequences from the microbiome communities. We also compare the results obtained using the commonly applied NGS primers and the Sanger sequencing approach. Finally, we describe three supergroups of Wolbachia: (i) a new supergroup V identified in Crustacea and Bivalvia hosts; (ii) supergroup A identified in Crustacea, Bivalvia, and Eutardigrada hosts, and (iii) supergroup E infection in the Crustacea host microbiome community.}, }
@article {pmid37296325, year = {2023}, author = {Chaúque, BJM and Corção, G and Benetti, AD and Rott, MB}, title = {A challenge in washing water with the sun: 24h of SODIS fails to inactivate Acanthamoeba castellanii cysts and internalized Pseudomonas aeruginosa under strong real sun conditions.}, journal = {Photochemical &amp; photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology}, volume = {}, number = {}, pages = {}, pmid = {37296325}, issn = {1474-9092}, abstract = {Despite access to drinking water being a basic human right, the availability of safe drinking water remains a privilege that many do not have and as a result, many lives are lost each year due to waterborne diseases associated with the consumption of biologically unsafe water. To face this situation, different low-cost household drinking water treatment technologies (HDWT) have been developed, and among them is solar disinfection (SODIS). Despite the effectiveness of SODIS and the epidemiological gains being consistently documented in the literature, there is a lack of evidence of the effectiveness of the batch-SODIS process against protozoan cysts as well as their internalized bacteria under real sun conditions. This work evaluated the effectiveness of the batch-SODIS process on the viability of Acanthamoeba castellanii cysts, and internalized Pseudomonas aeruginosa. Dechlorinated tap water contaminated with 5.6 × 10[3] cysts/L, contained in PET (polyethylene terephthalate) bottles, was exposed for 8 h a day to strong sunlight (531-1083 W/m[2] of maximum insolation) for 3 consecutive days. The maximum water temperature inside the reactors ranged from 37 to 50 °C. Cyst viability was assessed by inducing excystment on non-nutrient agar, or in water with heat-inactivated Escherichia coli. After sun exposure for 0, 8, 16 and 24 h, the cysts remained viable and without any perceptible impairment in their ability to excyst. 3 and 5.5 log CFU/mL of P. aeruginosa were detected in water containing untreated and treated cysts, respectively, after 3 days of incubation at 30 °C. The batch-SODIS process is unable to inactivate A. castellanii cysts as well as its internalized bacteria. Although the use of batch SODIS by communities should continue to be encouraged, SODIS-disinfected water should be consumed within 3 days.}, }
@article {pmid37292783, year = {2023}, author = {Samaddar, S and O'Neal, AJ and Marnin, L and Rolandelli, A and Singh, N and Wang, X and Butler, LR and Rangghran, P and Laukaitis, HJ and Cabrera Paz, FE and Fiskum, GM and Polster, BM and Pedra, JHF}, title = {Metabolic disruption impacts tick fitness and microbial relationships.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.05.26.542501}, pmid = {37292783}, abstract = {Arthropod-borne microbes rely on the metabolic state of a host to cycle between evolutionarily distant species. For instance, arthropod tolerance to infection may be due to redistribution of metabolic resources, often leading to microbial transmission to mammals. Conversely, metabolic alterations aids in pathogen elimination in humans, who do not ordinarily harbor arthropod-borne microbes. To ascertain the effect of metabolism on interspecies relationships, we engineered a system to evaluate glycolysis and oxidative phosphorylation in the tick Ixodes scapularis . Using a metabolic flux assay, we determined that the rickettsial bacterium Anaplasma phagocytophilum and the Lyme disease spirochete Borrelia burgdorferi , which are transstadially transmitted in nature, induced glycolysis in ticks. On the other hand, the endosymbiont Rickettsia buchneri, which is transovarially maintained, had a minimal effect on I. scapularis bioenergetics. Importantly, the metabolite β-aminoisobutyric acid (BAIBA) was elevated during A. phagocytophilum infection of tick cells following an unbiased metabolomics approach. Thus, we manipulated the expression of genes associated with the catabolism and anabolism of BAIBA in I. scapularis and detected impaired feeding on mammals, reduced bacterial acquisition, and decreased tick survival. Collectively, we reveal the importance of metabolism for tick-microbe relationships and unveil a valuable metabolite for I. scapularis fitness.}, }
@article {pmid37290396, year = {2023}, author = {Matulis, GA and Sakolvaree, J and Boldbaatar, B and Cleary, N and Takhampunya, R and Poole-Smith, BK and Lilak, AA and Altantogtokh, D and Tsogbadrakh, N and Chanarat, N and Youngdech, N and Lindroth, EJ and Fiorenzano, JM and Letizia, AG and von Fricken, ME}, title = {Applying next generation sequencing to detect tick-pathogens in Dermacentor nuttalli, Ixodes persulcatus, and Hyalomma asiaticum collected from Mongolia.}, journal = {Ticks and tick-borne diseases}, volume = {14}, number = {5}, pages = {102203}, doi = {10.1016/j.ttbdis.2023.102203}, pmid = {37290396}, issn = {1877-9603}, abstract = {Ticks and tick-borne diseases represent major threats to the public health of the Mongolian population, of which an estimated 26% live a traditional nomadic pastoralist lifestyle that puts them at increased risk for exposure. Ticks were collected by dragging and removal from livestock in Khentii, Selenge, Tuv, and Umnugovi aimags (provinces) during March-May 2020. Using next-generation sequencing (NGS) with confirmatory PCR and DNA sequencing, we sought to characterize the microbial species present in Dermacentor nuttalli (n = 98), Hyalomma asiaticum (n = 38), and Ixodes persulcatus (n = 72) tick pools. Rickettsia spp. were detected in 90.4% of tick pools, with Khentii, Selenge, and Tuv tick pools all having 100% pool positivity. Coxiella spp. were detected at an overall pool positivity rate of 60%, while Francisella spp. were detected in 20% of pools and Borrelia spp. detected in 13% of pools. Additional confirmatory testing for Rickettsia-positive pools demonstrated Rickettsia raoultii (n = 105), Candidatus Rickettsia tarasevichiae (n = 65) and R. slovaca/R. sibirica (n = 2), as well as the first report of Candidatus Rickettsia jingxinensis (n = 1) in Mongolia. For Coxiella spp. reads, most samples were identified as a Coxiella endosymbiont (n = 117), although Coxiella burnetii was detected in eight pools collected in Umnugovi. Borrelia species that were identified include Borrelia burgdorferi sensu lato (n = 3), B. garinii (n = 2), B. miyamotoi (n = 16), and B. afzelii (n = 3). All Francisella spp. reads were identified as Francisella endosymbiont species. Our findings emphasize the utility of NGS to provide baseline data across multiple tick-borne pathogen groups, which in turn can be used to inform health policy, determine regions for expanded surveillance, and guide risk mitigation strategies.}, }
@article {pmid37286189, year = {2023}, author = {Yang, Q and Gill, A and Robinson, KL and Umina, PA and Ross, PA and Zhan, D and Brown, C and Bell, N and MacMahon, A and Hoffmann, AA}, title = {A diversity of endosymbionts across Australian aphids and their persistence in aphid cultures.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16432}, pmid = {37286189}, issn = {1462-2920}, abstract = {There is increasing interest in the use of endosymbionts in pest control, which will benefit from the identification of endosymbionts from potential donor species for transfer to pest species. Here, we screened for endosymbionts in 123 Australian aphid samples across 32 species using 16S DNA metabarcoding. We then developed a qPCR method to validate the metabarcoding data set and to monitor endosymbiont persistence in aphid cultures. Pea aphids (Acyrthosiphon pisum) were frequently coinfected with Rickettsiella and Serratia, and glasshouse potato aphids (Aulacorthum solani) were coinfected with Regiella and Spiroplasma; other secondary endosymbionts detected in samples occurred by themselves. Hamiltonella, Rickettsia and Wolbachia were restricted to a single aphid species, whereas Regiella was found in multiple species. Rickettsiella, Hamiltonella and Serratia were stably maintained in laboratory cultures, although others were lost rapidly. The overall incidence of secondary endosymbionts in Australian samples tended to be lower than recorded from aphids overseas. These results indicate that aphid endosymbionts probably exhibit different levels of infectivity and vertical transmission efficiency across hosts, which may contribute to natural infection patterns. The rapid loss of some endosymbionts in cultures raises questions about factors that maintain them under field conditions, while endosymbionts that persisted in laboratory culture provide candidates for interspecific transfers.}, }
@article {pmid37285901, year = {2023}, author = {Nadal-Jimenez, P and Frost, CL and Cláudia Norte, A and Garrido-Bautista, J and Wilkes, TE and Connell, R and Rice, A and Krams, I and Eeva, T and Christe, P and Moreno-Rueda, G and Hurst, GDD}, title = {The son-killer microbe Arsenophonus nasoniae is a widespread associate of the parasitic wasp Nasonia vitripennis in Europe.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {107947}, doi = {10.1016/j.jip.2023.107947}, pmid = {37285901}, issn = {1096-0805}, abstract = {Heritable microbes that exhibit reproductive parasitism are common in insects. One class of these are the male-killing bacteria, which are found in a broad range of insect hosts. Commonly, our knowledge of the incidence of these microbes is based on one or a few sampling sites, and the degree and causes of spatial variation are unclear. In this paper, we examine the incidence of the son-killer microbe Arsenophonus nasoniae across European populations of its wasp host, Nasonia vitripennis. In preliminary work, we noticed two female N. vitripennis producing highly female biased sex ratios in a field study from the Netherlands and Germany. When tested, the brood from Germany was revealed to be infected with A. nasoniae. We then completed a broad survey in 2012, in which fly pupal hosts of N. vitripennis were collected from vacated birds' nests from four European populations, N. vitripennis wasps allowed to emerge and then tested for A. nasoniae presence through PCR assay. We then developed a new screening methodology based on direct PCR assays of fly pupae and applied this to ethanol-preserved material collected from great tit (Parus major) nests in Portugal. These data show A. nasoniae is found widely in European N. vitripennis, being present in Germany, the UK, Finland, Switzerland and Portugal. Samples varied in the frequency with which they carry A. nasoniae, from being rare to being present in 50% of the pupae parasitised by N. vitripennis. Direct screening of ethanol-preserved fly pupae was an effective method for revealing both wasp and A. nasoniae infection, and will facilitate sample transport across national boundaries. Future research should examine the causes of variation in frequency, in particular testing the hypothesis that N. vitripennis superparasitism rates drive the variation in A. nasoniae frequency through providing opportunities for infectious transmission.}, }
@article {pmid37285552, year = {2023}, author = {Hochstrasser, M}, title = {Molecular Biology of Cytoplasmic Incompatibility Caused by Wolbachia Endosymbionts.}, journal = {Annual review of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1146/annurev-micro-041020-024616}, pmid = {37285552}, issn = {1545-3251}, abstract = {Among endosymbiotic bacteria living within eukaryotic cells, Wolbachia is exceptionally widespread, particularly in arthropods. Inherited through the female germline, it has evolved ways to increase the fraction of bacterially infected offspring by inducing parthenogenesis, feminization, male killing, or, most commonly, cytoplasmic incompatibility (CI). In CI, Wolbachia infection of males causes embryonic lethality unless they mate with similarly infected females, creating a relative reproductive advantage for infected females. A set of related Wolbachia bicistronic operons encodes the CI-inducing factors. The downstream gene encodes a deubiquitylase or nuclease and is responsible for CI induction by males, while the upstream product when expressed in females binds its sperm-introduced cognate partner and rescues viability. Both toxin-antidote and host-modification mechanisms have been proposed to explain CI. Interestingly, male killing by either Spiroplasma or Wolbachia endosymbionts involves deubiquitylases as well. Interference with the host ubiquitin system may therefore be a common theme among endosymbiont-mediated reproductive alterations. Expected final online publication date for the Annual Review of Microbiology, Volume 77 is September 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.}, }
@article {pmid37278210, year = {2023}, author = {Xu, X and Hoffmann, AA and Umina, PA and Ward, SE and Coquilleau, MP and Malipatil, MB and Ridland, PM}, title = {Molecular identification of hymenopteran parasitoids and their endosymbionts from agromyzids.}, journal = {Bulletin of entomological research}, volume = {}, number = {}, pages = {1-16}, doi = {10.1017/S0007485323000160}, pmid = {37278210}, issn = {1475-2670}, abstract = {Three polyphagous pest Liriomyza spp. (Diptera: Agromyzidae) have recently invaded Australia and are damaging horticultural crops. Parasitic wasps are recognized as effective natural enemies of leafmining species globally and are expected to become important biocontrol agents in Australia. However, the hymenopteran parasitoid complex of agromyzids in Australia is poorly known and its use hindered due to taxonomic challenges when based on morphological characters. Here, we identified 14 parasitoid species of leafminers based on molecular and morphological data. We linked DNA barcodes (5' end cytochrome c oxidase subunit I (COI) sequences) to five adventive eulophid wasp species (Chrysocharis pubicornis (Zetterstedt), Diglyphus isaea (Walker), Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Westwood), and Neochrysocharis okazakii Kamijo) and two braconid species (Dacnusa areolaris (Nees) and Opius cinerariae Fischer). We also provide the first DNA barcodes (5' end COI sequences) with linked morphological characters for seven wasp species, with three identified to species level (Closterocerus mirabilis Edwards &amp; La Salle, Trigonogastrella parasitica (Girault), and Zagrammosoma latilineatum Ubaidillah) and four identified to genus (Aprostocetus sp., Asecodes sp., Opius sp. 1, and Opius sp. 2). Phylogenetic analyses suggest C. pubicornis, D. isaea, H. varicornis, and O. cinerariae are likely cryptic species complexes. Neochrysocharis formosa and Aprostocetus sp. specimens were infected with Rickettsia. Five other species (Cl. mirabilis, D. isaea, H. varicornis, Opius sp. 1, and Opius sp. 2) were infected with Wolbachia, while two endosymbionts (Rickettsia and Wolbachia) co-infected N. okazakii. These findings provide background information about the parasitoid fauna expected to help control the leafminers.}, }
@article {pmid37267326, year = {2023}, author = {Spencer, N and Łukasik, P and Meyer, M and Veloso, C and McCutcheon, JP}, title = {No Transcriptional Compensation for Extreme Gene Dosage Imbalance in Fragmented Bacterial Endosymbionts of Cicadas.}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evad100}, pmid = {37267326}, issn = {1759-6653}, abstract = {Bacteria that form long-term intracellular associations with host cells lose many genes, a process that often results in tiny, gene-dense, and stable genomes. Paradoxically, the same evolutionary processes that drive genome reduction and simplification may sometimes cause genome expansion and complexification. A bacterial endosymbiont of cicadas, Hodgkinia cicadicola, exemplifies this paradox. In many cicada species, a single Hodgkinia lineage with a tiny, gene-dense genome has split into several interdependent cell and genome lineages. Each new Hodgkinia lineage encodes a unique subset of the ancestral unsplit genome in a complementary way, such that the collective gene contents of all lineages match the total found in the ancestral single genome. This splitting creates genetically distinct Hodgkinia cells that must function together to carry out basic cellular processes. It also creates a gene dosage problem where some genes are encoded by only a small fraction of cells while others are much more abundant. Here, by sequencing DNA and RNA of Hodgkinia from different cicada species with different amounts of splitting - along with its structurally stable, unsplit partner endosymbiont Sulcia muelleri - we show that Hodgkinia does not transcriptionally compensate to rescue the wildly unbalanced gene and genome ratios that result from lineage splitting. We also find that Hodgkinia has a reduced capacity for basic transcriptional control independent of the splitting process. Our findings reveal another layer of degeneration further pushing the limits of canonical molecular and cell biology in Hodgkinia and may partially explain its propensity to go extinct through symbiont replacement.}, }
@article {pmid37264036, year = {2023}, author = {Armstrong, EJ and Lê-Hoang, J and Carradec, Q and Aury, JM and Noel, B and Hume, BCC and Voolstra, CR and Poulain, J and Belser, C and Paz-García, DA and Cruaud, C and Labadie, K and Da Silva, C and Moulin, C and Boissin, E and Bourdin, G and Iwankow, G and Romac, S and Agostini, S and Banaigs, B and Boss, E and Bowler, C and de Vargas, C and Douville, E and Flores, M and Forcioli, D and Furla, P and Galand, PE and Gilson, E and Lombard, F and Pesant, S and Reynaud, S and Sullivan, MB and Sunagawa, S and Thomas, OP and Troublé, R and Thurber, RV and Zoccola, D and Planes, S and Allemand, D and Wincker, P}, title = {Host transcriptomic plasticity and photosymbiotic fidelity underpin Pocillopora acclimatization across thermal regimes in the Pacific Ocean.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {3056}, pmid = {37264036}, issn = {2041-1723}, abstract = {Heat waves are causing declines in coral reefs globally. Coral thermal responses depend on multiple, interacting drivers, such as past thermal exposure, endosymbiont community composition, and host genotype. This makes the understanding of their relative roles in adaptive and/or plastic responses crucial for anticipating impacts of future warming. Here, we extracted DNA and RNA from 102 Pocillopora colonies collected from 32 sites on 11 islands across the Pacific Ocean to characterize host-photosymbiont fidelity and to investigate patterns of gene expression across a historical thermal gradient. We report high host-photosymbiont fidelity and show that coral and microalgal gene expression respond to different drivers. Differences in photosymbiotic association had only weak impacts on host gene expression, which was more strongly correlated with the historical thermal environment, whereas, photosymbiont gene expression was largely determined by microalgal lineage. Overall, our results reveal a three-tiered strategy of thermal acclimatization in Pocillopora underpinned by host-photosymbiont specificity, host transcriptomic plasticity, and differential photosymbiotic association under extreme warming.}, }
@article {pmid37261959, year = {2023}, author = {Kim, SJ and Jo, J and Ko, KS}, title = {Lipid A modification-induced colistin-resistant Klebsiella variicola from healthy adults.}, journal = {Journal of medical microbiology}, volume = {72}, number = {6}, pages = {}, doi = {10.1099/jmm.0.001680}, pmid = {37261959}, issn = {1473-5644}, abstract = {Background. Klebsiella variicola was once recognised as a benign plant-endosymbiont but recent case reports suggest that it is a newly emerging Gram-negative pathogen related to opportunistic infection of multiple sites in humans.Methods. Antimicrobial susceptibility testing was performed using broth microdilution method. To identify colistin resistance mechanisms, phoPQ, pmrAB, and mgrB were sequenced and their mRNA expression was analysed using quantitative real-time PCR. In addition, we tried to detect crrAB and mcr. The lipid A moieties of colistin-susceptible and -resistant isolates were analysed using MALDI-TOF.Results. Among the two K. variicola isolates, one is colistin-resistant, and another is colistin-susceptible. The colistin-resistant K. variicola isolate showed no mutations in phoPQ, pmrAB, and mgrB, and crrAB and mcr were not identified. However, its phoQ and pbgP expression was significantly higher and amino-arabinosylated lipid A with hexa-acylated species in lipopolysaccharide was identified.Conclusions. We found that colistin resistance in K. variicola was mediated by the modification of lipid A. Although the isolate was obtained from faecal samples of healthy adults, colistin-resistant K. variicola challenges public health as an opportunistic pathogen.}, }
@article {pmid37256931, year = {2023}, author = {Liu, M and Hong, G and Li, H and Bing, X and Chen, Y and Jing, X and Gershenzon, J and Lou, Y and Baldwin, IT and Li, R}, title = {Sakuranetin protects rice from brown planthopper attack by depleting its beneficial endosymbionts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {23}, pages = {e2305007120}, doi = {10.1073/pnas.2305007120}, pmid = {37256931}, issn = {1091-6490}, abstract = {Plants produce chemical defenses that poison insect herbivores or deter their feeding, but herbivores are also accompanied by microbial endosymbionts crucial for their nutrition, reproduction, and fitness. Hence, plant defenses could target a herbivore's beneficial endosymbionts, but this has not yet been demonstrated. Here, we studied flavonoids that are induced when rice is attacked by a phloem-feeding pest, the brown planthopper (BPH), which harbors beneficial yeast-like symbionts (YLS) essential for insect nutrition, such as by remedying deficiencies in sterols. BPH attack dramatically increased sakuranetin accumulations in leaf sheaths and phloem exudates. Sakuranetin is an antifungal phytoalexin derived from the antibacterial precursor, naringenin, via catalysis of naringenin-O-methyltransferase (NOMT). When added to artificial diets, sakuranetin decreased BPH survivorship, suggesting that it functions as an induced defense. Mutation of NOMT abolished sakuranetin accumulation and increased BPH oviposition and hatching rates. High-throughput amplicon sequencing revealed that BPH fed on sakuranetin-deficient nomt lines were enriched in YLS with only minor changes in the bacterial endosymbionts, compared to those feeding on sakuranetin-rich wild-type (WT) plants. In-vitro feeding of sakuranetin suggested that this flavonoid directly inhibited the growth of YLS. BPH feeding on nomt lines accumulated higher cholesterol levels, which might be attributed to increases in the supply of sterol precursors from the YLS, while nomt lines suffered more damage than WT plants did from BPH herbivory. BPH-elicited accumulation of sakuranetin requires intact jasmonate (JA) signaling. This study reveals that rice uses a JA-induced antifungal flavonoid phytoalexin in defense against BPH by inhibiting its beneficial endosymbionts.}, }
@article {pmid37250803, year = {2023}, author = {Arai, H and Anbutsu, H and Nishikawa, Y and Kogawa, M and Ishii, K and Hosokawa, M and Lin, SR and Ueda, M and Nakai, M and Kunimi, Y and Harumoto, T and Kageyama, D and Takeyama, H and Inoue, MN}, title = {Combined actions of bacteriophage-encoded genes in Wolbachia-induced male lethality.}, journal = {iScience}, volume = {26}, number = {6}, pages = {106842}, pmid = {37250803}, issn = {2589-0042}, abstract = {Some Wolbachia endosymbionts induce male killing, whereby male offspring of infected females are killed during development; however, the origin and diversity of the underlying mechanisms remain unclear. In this study, we identified a 76 kbp prophage region specific to male-killing Wolbachia hosted by the moth Homona magnanima. The prophage encoded a homolog of the male-killing gene oscar in Ostrinia moths and the wmk gene that induces various toxicities in Drosophila melanogaster. Upon overexpressing these genes in D. melanogaster, wmk-1 and wmk-3 killed all males and most females, whereas Hm-oscar, wmk-2, and wmk-4 had no impact on insect survival. Strikingly, co-expression of tandemly arrayed wmk-3 and wmk-4 killed 90% of males and restored 70% of females, suggesting their conjugated functions for male-specific lethality. While the male-killing gene in the native host remains unknown, our findings highlight the role of bacteriophages in male-killing evolution and differences in male-killing mechanisms among insects.}, }
@article {pmid37247378, year = {2023}, author = {Oladipupo, SO and Laidoudi, Y and Beckmann, JF and Hu, XP and Appel, AG}, title = {The prevalence of Wolbachia in multiple cockroach species and its implication for urban insect management.}, journal = {Journal of economic entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jee/toad098}, pmid = {37247378}, issn = {1938-291X}, abstract = {Cockroach management relies heavily on the use of conventional insecticides in urban settings, which no longer provide the anticipated level of control. Knowledge of cockroach endosymbionts, like Wolbachia, might provide novel avenues for control. Therefore, we screened 16 cockroach species belonging to 3 families (Ectobiidae, Blattidae, and Blaberidae) for the presence of Wolbachia. We mapped the evolution of Wolbachia-cockroach relationships based on maximum likelihood phylogeny and phylogenetic species clustering on a multi-loci sequence dataset (i.e., coxA, virD4, hcpA, and gatB) of Wolbachia genes. We confirmed the previous report of Wolbachia in 1 Ectobiid species; Supella longipalpa (Fab.), and detected the presence of Wolbachia in 2 Ectobiid species; Balta notulata (Stål) and Pseudomops septentrionalis Hebard, and 1 Blaberid species; Gromphadorhina portentosa (Schaum). All cockroach-associated Wolbachia herein detected were clustered with the ancestor of F clade Wolbachia of Cimex lectularius L. (bed bugs). Since Wolbachia provision C. lectularius with biotin vitamins that confer reproductive fitness, we screened the cockroach-associated Wolbachia for the presence of biotin genes. In toto, our results reveal 2 important findings: (i) Wolbachia is relatively uncommon among cockroach species infecting about 25% of species investigated, and (ii) cockroach-associated Wolbachia have biotin genes that likely provide nutritional benefits to their hosts. Thus, we discuss the potential of exploring Wolbachia as a tool for urban insect management.}, }
@article {pmid37240058, year = {2023}, author = {Mohammad Aslam, S and Vass, I and Szabó, M}, title = {Characterization of the Flash-Induced Fluorescence Wave Phenomenon in the Coral Endosymbiont Algae, Symbiodiniaceae.}, journal = {International journal of molecular sciences}, volume = {24}, number = {10}, pages = {}, doi = {10.3390/ijms24108712}, pmid = {37240058}, issn = {1422-0067}, abstract = {The dinoflagellate algae, Symbiodiniaceae, are significant symbiotic partners of corals due to their photosynthetic capacity. The photosynthetic processes of the microalgae consist of linear electron transport, which provides the energetic balance of ATP and NADPH production for CO2 fixation, and alternative electron transport pathways, including cyclic electron flow, which ensures the elevated ATP requirements under stress conditions. Flash-induced chlorophyll fluorescence relaxation is a non-invasive tool to assess the various electron transport pathways. A special case of fluorescence relaxation, the so-called wave phenomenon, was found to be associated with the activity of NAD(P)H dehydrogenase (NDH) in microalgae. We showed previously that the wave phenomenon existed in Symbiodiniaceae under acute heat stress and microaerobic conditions, however, the electron transport processes related to the wave phenomenon remained unknown. In this work, using various inhibitors, we show that (i) the linear electron transport has a crucial role in the formation of the wave, (ii) the inhibition of the donor side of Photosystem II did not induce the wave, whereas inhibition of the Calvin-Benson cycle accelerated it, (iii) the wave phenomenon was related to the operation of type II NDH (NDH-2). We therefore propose that the wave phenomenon is an important marker of the regulation of electron transport in Symbiodiniaceae.}, }
@article {pmid37237521, year = {2023}, author = {Pomahač, O and Méndez-Sánchez, D and Poláková, K and Müller, M and Solito, MM and Bourland, WA and Čepička, I}, title = {Rediscovery of Remarkably Rare Anaerobic Tentaculiferous Ciliate Genera Legendrea and Dactylochlamys (Ciliophora: Litostomatea).}, journal = {Biology}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/biology12050707}, pmid = {37237521}, issn = {2079-7737}, abstract = {Free-living anaerobic ciliates are of considerable interest from an ecological and an evolutionary standpoint. Extraordinary tentacle-bearing predatory lineages have evolved independently several times within the phylum Ciliophora, including two rarely encountered anaerobic litostomatean genera, Legendrea and Dactylochlamys. In this study, we significantly extend the morphological and phylogenetic characterization of these two poorly known groups of predatory ciliates. We provide the first phylogenetic analysis of the monotypic genus Dactylochlamys and the three valid species of Legendrea based on the 18S rRNA gene and ITS-28S rRNA gene sequences. Prior to this study, neither group had been studied using silver impregnation methods. We provide the first protargol-stained material and also a unique video material including documentation, for the first time, of the hunting and feeding behavior of a Legendrea species. We briefly discuss the identity of methanogenic archaeal and bacterial endosymbionts of both genera based on 16S rRNA gene sequences, and the importance of citizen science for ciliatology from a historical and contemporary perspective.}, }
@article {pmid37237053, year = {2023}, author = {Tillmann, U and Wietkamp, S and Kretschmann, J and Chacón, J and Gottschling, M}, title = {Spatial fragmentation in the distribution of diatom endosymbionts from the taxonomically clarified dinophyte Kryptoperidinium triquetrum (= Kryptoperidinium foliaceum, Peridiniales).}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {8593}, pmid = {37237053}, issn = {2045-2322}, abstract = {Among the photosynthetically active dinophytes, the Kryptoperidiniaceae are unique in having a diatom as endosymbiont instead of the widely present peridinin chloroplast. Phylogenetically, it is unresolved at present how the endosymbionts are inherited, and the taxonomic identities of two iconic dinophyte names, Kryptoperidinium foliaceum and Kryptoperidinium triquetrum, are also unclear. Multiple strains were newly established from the type locality in the German Baltic Sea off Wismar and inspected using microscopy as well as molecular sequence diagnostics of both host and endosymbiont. All strains were bi-nucleate, shared the same plate formula (i.e., po, X, 4', 2a, 7'', 5c, 7s, 5''', 2'''') and exhibited a narrow and characteristically L-shaped precingular plate 7''. Within the molecular phylogeny of Bacillariaceae, endosymbionts were scattered over the tree in a highly polyphyletic pattern, even if they were gained from different strains of a single species, namely K. triquetrum. Notably, endosymbionts from the Baltic Sea show molecular sequences distinct from the Atlantic and the Mediterranean Sea, which is the first report of such a spatial fragmentation in a planktonic species of dinophytes. The two names K. foliaceum and K. triquetrum are taxonomically clarified by epitypification, with K. triquetrum having priority over its synonym K. foliaceum. Our study underlines the need of stable taxonomy for central questions in evolutionary biology.}, }
@article {pmid37231093, year = {2023}, author = {Bruner-Montero, G and Jiggins, FM}, title = {Wolbachia protects Drosophila melanogaster against two naturally occurring and virulent viral pathogens.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {8518}, pmid = {37231093}, issn = {2045-2322}, abstract = {Wolbachia is a common endosymbiont that can protect insects against viral pathogens. However, whether the antiviral effects of Wolbachia have a significant effect on fitness remains unclear. We have investigated the interaction between Drosophila melanogaster, Wolbachia and two viruses that we recently isolated from wild flies, La Jolla virus (LJV; Iflaviridae) and Newfield virus (NFV; Permutotetraviridae). Flies infected with these viruses have increased mortality rates, and NFV partially sterilizes females. These effects on fitness were reduced in Wolbachia-infected flies, and this was associated with reduced viral titres. However, Wolbachia alone also reduces survival, and under our experimental conditions these costs of the symbiont can outweigh the benefits of antiviral protection. In contrast, protection against the sterilizing effect of NFV leads to a net benefit of Wolbachia infection after exposure to the virus. These results support the hypothesis that Wolbachia is an important defense against the natural pathogens of D. melanogaster. Furthermore, by reducing the cost of Wolbachia infection, the antiviral effects of Wolbachia may aid its invasion into populations and help explain why it is so common in nature.}, }
@article {pmid37226596, year = {2023}, author = {Medina, JM and Queller, DC and Strassmann, JE and Garcia, JR}, title = {The social amoeba dictyostelium discoideum rescues paraburkholderia hayleyella, but not P. agricolaris, from interspecific competition.}, journal = {FEMS microbiology ecology}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsec/fiad055}, pmid = {37226596}, issn = {1574-6941}, abstract = {Bacterial endosymbionts can provide benefits for their eukaryotic hosts, but it is often unclear if endosymbionts benefit from these relationships. The social amoeba Dictyostelium discoideum associates with three species of Paraburkholderia endosymbionts, including P. agricolaris and P. hayleyella. These endosymbionts can be costly to host but are beneficial in certain contexts because they allow D. discoideum to carry prey bacteria through the dispersal stage. In experiments where no other species are present, P. hayleyella benefits from D. discoideum while P. agricolaris does not. However, the presence of other species may influence this symbiosis. We tested if P. agricolaris and P. hayleyella benefit from D. discoideum in the context of resource competition with Klebsiella pneumoniae, the typical laboratory prey of D. discoideum. Without D. discoideum, K. pneumoniae depressed the growth of both Paraburkholderia symbionts, consistent with competition. P. hayleyella was more harmed by interspecific competition than P. agricolaris. We found that P. hayleyella was rescued from competition by D. discoideum while P. agricolaris was not. This may be because P. hayleyella is more specialized as an endosymbiont; it has a highly reduced genome compared to P. agricolaris and may have lost genes relevant for resource competition outside of its host.}, }
@article {pmid37223258, year = {2021}, author = {Marra, A and Masson, F and Lemaitre, B}, title = {The iron transporter Transferrin 1 mediates homeostasis of the endosymbiotic relationship between Drosophila melanogaster and Spiroplasma poulsonii.}, journal = {microLife}, volume = {2}, number = {}, pages = {uqab008}, pmid = {37223258}, issn = {2633-6693}, abstract = {Iron is involved in numerous biological processes in both prokaryotes and eukaryotes and is therefore subject to a tug-of-war between host and microbes upon pathogenic infections. In the fruit fly Drosophila melanogaster, the iron transporter Transferrin 1 (Tsf1) mediates iron relocation from the hemolymph to the fat body upon infection as part of the nutritional immune response. The sequestration of iron in the fat body renders it less available for pathogens, hence limiting their proliferation and enhancing the host ability to fight the infection. Here we investigate the interaction between host iron homeostasis and Spiroplasma poulsonii, a facultative, vertically transmitted, endosymbiont of Drosophila. This low-pathogenicity bacterium is devoid of cell wall and is able to thrive in the host hemolymph without triggering pathogen-responsive canonical immune pathways. However, hemolymph proteomics revealed an enrichment of Tsf1 in infected flies. We find that S. poulsonii induces tsf1 expression and triggers an iron sequestration response similarly to pathogenic bacteria. We next demonstrate that free iron cannot be used by Spiroplasma while Tsf1-bound iron promotes bacterial growth, underlining the adaptation of Spiroplasma to the intra-host lifestyle where iron is mostly protein-bound. Our results show that Tsf1 is used both by the fly to sequester iron and by Spiroplasma to forage host iron, making it a central protein in endosymbiotic homeostasis.}, }
@article {pmid37214831, year = {2023}, author = {Mfopit, YM and Weber, JS and Chechet, GD and Ibrahim, MAM and Signaboubo, D and Achukwi, DM and Mamman, M and Balogun, EO and Shuaibu, MN and Kabir, J and Kelm, S}, title = {Molecular detection of Sodalis glossinidius, Spiroplasma and Wolbachia endosymbionts in wild population of tsetse flies collected in Cameroon, Chad and Nigeria.}, journal = {Research square}, volume = {}, number = {}, pages = {}, doi = {10.21203/rs.3.rs-2902767/v1}, pmid = {37214831}, abstract = {Background Tsetse flies are cyclical vectors of African trypanosomiasis. They have established symbiotic associations with different bacteria, which influence certain aspects of their physiology. The vector competence of tsetse flies for different trypanosome species is highly variable and is suggested to be affected by various factors, amongst which are bacterial endosymbionts. Symbiotic interactions may provide an avenue for the disease control. The current study provided the prevalence of 3 tsetse symbionts in Glossina species from Cameroon, Chad and Nigeria. Results Tsetse flies were collected from five different locations and dissected. DNA was extracted and polymerase chain reaction PCR was used to detect the presence of Sodalis glossinidius , Spiroplasma sp and Wolbachia using specific primers. A total of 848 tsetse samples were analysed: Glossina morsitans submorsitans (47.52%), Glossina palpalis palpalis (37.26%), Glossina fuscipes fuscipes (9.08%) and Glossina tachinoides (6.13%). Only 95 (11.20%) were infected with at least one of the 3 symbionts. Among the infected, 6 (6.31%) were carrying mixed infection (Wolbachia and Spiroplasma). The overall symbiont prevalence was 0.88%, 3.66% and 11.00% respectively, for Sodalis , Spiroplasma and Wolbachia . Prevalence varied between countries and tsetse species. No Spiroplasma was detected in samples from Cameroon and no Sodalis was found in samples from Nigeria. Conclusion The present study revealed for the first time, the presence of infection by Spiroplasma in tsetse in Chad and Nigeria. These findings provide useful information to the repertoire of bacterial flora of tsetse flies and incite to more investigations to understand their implication in the vector competence of tsetse flies.}, }
@article {pmid37213490, year = {2023}, author = {Jackson, R and Patapiou, PA and Golding, G and Helanterä, H and Economou, CK and Chapuisat, M and Henry, LM}, title = {Evidence of phylosymbiosis in Formica ants.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1044286}, pmid = {37213490}, issn = {1664-302X}, abstract = {INTRODUCTION: Insects share intimate relationships with microbes that play important roles in their biology. Yet our understanding of how host-bound microbial communities assemble and perpetuate over evolutionary time is limited. Ants host a wide range of microbes with diverse functions and are an emerging model for studying the evolution of insect microbiomes. Here, we ask whether phylogenetically related ant species have formed distinct and stable microbiomes.<br><br>METHODS: To answer this question, we investigated the microbial communities associated with queens of 14 Formica species from five clades, using deep coverage 16S rRNA amplicon sequencing.<br><br>RESULTS: We reveal that Formica species and clades harbor highly defined microbial communities that are dominated by four bacteria genera: Wolbachia, Lactobacillus, Liliensternia, and Spiroplasma. Our analysis reveals that the composition of Formica microbiomes mirrors the phylogeny of the host, i.e., phylosymbiosis, in that related hosts harbor more similar microbial communities. In addition, we find there are significant correlations between microbe co-occurrences.<br><br>DISCUSSION: Our results demonstrate Formica ants carry microbial communities that recapitulate the phylogeny of their hosts. Our data suggests that the co-occurrence of different bacteria genera may at least in part be due to synergistic and antagonistic interactions between microbes. Additional factors potentially contributing to the phylosymbiotic signal are discussed, including host phylogenetic relatedness, host-microbe genetic compatibility, modes of transmission, and similarities in host ecologies (e.g., diets). Overall, our results support the growing body of evidence that microbial community composition closely depends on the phylogeny of their hosts, despite bacteria having diverse modes of transmission and localization within the host.}, }
@article {pmid37206333, year = {2023}, author = {Russo, N and Floridia, V and D'Alessandro, E and Lopreiato, V and Pino, A and Chiofalo, V and Caggia, C and Liotta, L and Randazzo, CL}, title = {Influence of olive cake dietary supplementation on fecal microbiota of dairy cows.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1137452}, doi = {10.3389/fmicb.2023.1137452}, pmid = {37206333}, issn = {1664-302X}, abstract = {Olive by-products represent a valuable low-price feed supplement for animal nutrition. In the present study, the effect of the dietary destoned olive cake supplementation, on both composition and dynamics of the fecal bacterial biota of cow, was assessed by Illumina MiSeq analysis of the 16S rRNA gene. In addition, metabolic pathways were predicted by using the PICRUSt2 bioinformatic tool. Eighteen lactating cows, according to the body condition score, the days from calving, and the daily milk production were homogeneously allocated into two groups, control or experimental, and subjected to different dietary treatments. In detail, the experimental diet contained, along with the components of the control one, 8% of destoned olive cake. Metagenomics data revealed significant differences in abundance rather than in richness between the two groups. Results showed that Bacteroidota and Firmicutes were identified as the dominant phyla, accounting for over 90% of the total bacterial population. The Desulfobacterota phylum, able to reduce sulfur compounds, was detected only in fecal samples of cows allocated to the experimental diet whereas the Elusimicrobia phylum, a common endosymbiont or ectosymbiont of various flagellated protists, was detected only in cows subjected to the control diet. In addition, both Oscillospiraceae and Ruminococcaceae families were mainly found in the experimental group whereas fecal samples of control cows showed the presence of Rikenellaceae and Bacteroidaceae families, usually associated with the high roughage or low concentrate diet. Based on the PICRUSt2 bioinformatic tool, pathways related to carbohydrate, fatty acid, lipid, and amino acids biosynthesis were mainly up regulated in the experimental group. On the contrary, in the control group, the metabolic pathways detected with the highest occurrence were associated with amino acids biosynthesis and degradation, aromatic compounds degradation, nucleosides and nucleotides biosynthesis. Hence, the present study confirms that the destoned olive cake is a valuable feed supplement able to modulate the fecal microbiota of cows. Further studies will be conducted in order to deepen the inter-relationships between the GIT microbiota and the host.}, }
@article {pmid37205465, year = {2023}, author = {Holguin-Rocha, AF and Calle-Tobon, A and Vásquez, GM and Astete, H and Fisher, ML and Tobon-Castano, A and Velez-Tobon, G and Maldonado-Ruiz, LP and Silver, K and Park, Y and Londono-Renteria, B}, title = {Diversity of the bacterial and viral communities in the tropical horse tick, Dermacentor nitens in Colombia.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.05.04.539352}, pmid = {37205465}, abstract = {Ticks are obligatory hematophagous ectoparasites that transmit pathogens among various vertebrates, including humans. The composition of the microbial and viral communities in addition to the pathogenic microorganisms is highly diverse in ticks, but the factors driving the diversity are not well understood. The tropical horse tick, Dermacentor nitens , is distributed throughout the Americas and it is recognized as a natural vector of Babesia caballi and Theileria equi , the causal agents of equine piroplasmosis. We characterized the bacterial and viral communities associated with partially-fed D. nitens females collected by a passive survey on horses from field sites representing three distinct geographical areas in Colombia (Bolivar, Antioquia, and Cordoba). RNA-seq and sequencing of the V3 and V4 hypervariable regions of the 16S rRNA gene were performed using the Illumina-Miseq platform. A total of 356 operational taxonomic units (OTUs) were identified, in which the presumed endosymbiotic Francisellaceae/ Francisella spp. was predominantly found. Nine contigs corresponding to six different viruses were identified in three viral families: Chuviridae, Rhabdoviridae, and Flaviviridae. Differences in the relative abundance of the microbial composition among the geographical regions were found to be independent of the presence of Francisella -Like Endosymbiont (FLE). The most prevalent bacteria found on each region were Corynebacterium in Bolivar, Staphylococcus in Antioquia, and Pseudomonas in Cordoba. Rickettsia -like endosymbionts, mainly recognized as the etiological agent of rickettsioses in Colombia were detected in the Cordoba samples. Metatranscriptomics revealed 13 contigs containing FLE genes, suggesting a trend of regional differences. These findings suggest regional distinctions among the ticks and their bacterial compositions.}, }
@article {pmid37201521, year = {2023}, author = {Zakharova, A and Tashyreva, D and Butenko, A and Morales, J and Saura, A and Svobodová, M and Poschmann, G and Nandipati, S and Zakharova, A and Noyvert, D and Gahura, O and Týč, J and Stühler, K and Kostygov, AY and Nowack, ECM and Lukeš, J and Yurchenko, V}, title = {A neo-functionalized homolog of host transmembrane protein controls localization of bacterial endosymbionts in the trypanosomatid Novymonas esmeraldas.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2023.04.060}, pmid = {37201521}, issn = {1879-0445}, abstract = {The stability of endosymbiotic associations between eukaryotes and bacteria depends on a reliable mechanism ensuring vertical inheritance of the latter. Here, we demonstrate that a host-encoded protein, located at the interface between the endoplasmic reticulum of the trypanosomatid Novymonas esmeraldas and its endosymbiotic bacterium Ca. Pandoraea novymonadis, regulates such a process. This protein, named TMP18e, is a product of duplication and neo-functionalization of the ubiquitous transmembrane protein 18 (TMEM18). Its expression level is increased at the proliferative stage of the host life cycle correlating with the confinement of bacteria to the nuclear vicinity. This is important for the proper segregation of bacteria into the daughter host cells as evidenced from the TMP18e ablation, which disrupts the nucleus-endosymbiont association and leads to greater variability of bacterial cell numbers, including an elevated proportion of aposymbiotic cells. Thus, we conclude that TMP18e is necessary for the reliable vertical inheritance of endosymbionts.}, }
@article {pmid37196858, year = {2023}, author = {Ward, MCE and Barrios, MC and Fallon, AM}, title = {Paraquat is toxic to the soil-dwelling arthropod, Folsomia candida (Collembola: Isotomidae), and has potential effects on its Wolbachia endosymbiont.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {107936}, doi = {10.1016/j.jip.2023.107936}, pmid = {37196858}, issn = {1096-0805}, abstract = {The springtail, Folsomia candida, is a soil arthropod commonly used to evaluate environmental toxins. Conflicting data on the toxicity of the herbicide paraquat prompted re-evaluation of its effects on F. candida survival and reproduction. Paraquat has an LC50 of about 80 μM when tested in the absence of charcoal; charcoal, often used in test arenas to facilitate visualization of the white Collembola, has a protective effect. Survivors of paraquat treatment fail to resume molting and oviposition, suggesting an irreversible effect on the Wolbachia symbiont that restores diploidy during parthenogenetic reproduction of this species.}, }
@article {pmid37198188, year = {2023}, author = {Moggioli, G and Panossian, B and Sun, Y and Thiel, D and Martín-Zamora, FM and Tran, M and Clifford, AM and Goffredi, SK and Rimskaya-Korsakova, N and Jékely, G and Tresguerres, M and Qian, PY and Qiu, JW and Rouse, GW and Henry, LM and Martín-Durán, JM}, title = {Distinct genomic routes underlie transitions to specialised symbiotic lifestyles in deep-sea annelid worms.}, journal = {Nature communications}, volume = {14}, number = {1}, pages = {2814}, pmid = {37198188}, issn = {2041-1723}, abstract = {Bacterial symbioses allow annelids to colonise extreme ecological niches, such as hydrothermal vents and whale falls. Yet, the genetic principles sustaining these symbioses remain unclear. Here, we show that different genomic adaptations underpin the symbioses of phylogenetically related annelids with distinct nutritional strategies. Genome compaction and extensive gene losses distinguish the heterotrophic symbiosis of the bone-eating worm Osedax frankpressi from the chemoautotrophic symbiosis of deep-sea Vestimentifera. Osedax's endosymbionts complement many of the host's metabolic deficiencies, including the loss of pathways to recycle nitrogen and synthesise some amino acids. Osedax's endosymbionts possess the glyoxylate cycle, which could allow more efficient catabolism of bone-derived nutrients and the production of carbohydrates from fatty acids. Unlike in most Vestimentifera, innate immunity genes are reduced in O. frankpressi, which, however, has an expansion of matrix metalloproteases to digest collagen. Our study supports that distinct nutritional interactions influence host genome evolution differently in highly specialised symbioses.}, }
@article {pmid37196086, year = {2023}, author = {Maire, J and Tandon, K and Collingro, A and van de Meene, A and Damjanovic, K and Gotze, CR and Stephenson, S and Philip, GK and Horn, M and Cantin, NE and Blackall, LL and van Oppen, MJH}, title = {Colocalization and potential interactions of Endozoicomonas and chlamydiae in microbial aggregates of the coral Pocillopora acuta.}, journal = {Science advances}, volume = {9}, number = {20}, pages = {eadg0773}, doi = {10.1126/sciadv.adg0773}, pmid = {37196086}, issn = {2375-2548}, abstract = {Corals are associated with a variety of bacteria, which occur in the surface mucus layer, gastrovascular cavity, skeleton, and tissues. Some tissue-associated bacteria form clusters, termed cell-associated microbial aggregates (CAMAs), which are poorly studied. Here, we provide a comprehensive characterization of CAMAs in the coral Pocillopora acuta. Combining imaging techniques, laser capture microdissection, and amplicon and metagenome sequencing, we show that (i) CAMAs are located in the tentacle tips and may be intracellular; (ii) CAMAs contain Endozoicomonas (Gammaproteobacteria) and Simkania (Chlamydiota) bacteria; (iii) Endozoicomonas may provide vitamins to its host and use secretion systems and/or pili for colonization and aggregation; (iv) Endozoicomonas and Simkania occur in distinct, but adjacent, CAMAs; and (v) Simkania may receive acetate and heme from neighboring Endozoicomonas. Our study provides detailed insight into coral endosymbionts, thereby improving our understanding of coral physiology and health and providing important knowledge for coral reef conservation in the climate change era.}, }
@article {pmid37192168, year = {2023}, author = {Kulkarni, A and Ewen-Campen, B and Terao, K and Matsumoto, Y and Li, Y and Watanabe, T and Kao, JA and Parhad, SS and Ylla, G and Mizunami, M and Extavour, CG}, title = {oskar acts with the transcription factor Creb to regulate long-term memory in crickets.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {21}, pages = {e2218506120}, doi = {10.1073/pnas.2218506120}, pmid = {37192168}, issn = {1091-6490}, abstract = {Novel genes have the potential to drive the evolution of new biological mechanisms, or to integrate into preexisting regulatory circuits and contribute to the regulation of older, conserved biological functions. One such gene, the novel insect-specific gene oskar, was first identified based on its role in establishing the Drosophila melanogaster germ line. We previously showed that this gene likely arose through an unusual domain transfer event involving bacterial endosymbionts and played a somatic role before evolving its well-known germ line function. Here, we provide empirical support for this hypothesis in the form of evidence for a neural role for oskar. We show that oskar is expressed in the adult neural stem cells of a hemimetabolous insect, the cricket Gryllus bimaculatus. In these stem cells, called neuroblasts, oskar is required together with the ancient animal transcription factor Creb to regulate long-term (but not short-term) olfactory memory. We provide evidence that oskar positively regulates Creb, which plays a conserved role in long-term memory across animals, and that oskar in turn may be a direct target of Creb. Together with previous reports of a role for oskar in nervous system development and function in crickets and flies, our results are consistent with the hypothesis that oskar's original somatic role may have been in the insect nervous system. Moreover, its colocalization and functional cooperation with the conserved pluripotency gene piwi in the nervous system may have facilitated oskar's later co-option to the germ line in holometabolous insects.}, }
@article {pmid37186593, year = {2023}, author = {Martoni, F and Bulman, SR and Piper, AM and Pitman, A and Taylor, GS and Armstrong, KF}, title = {Insect phylogeny structures the bacterial communities in the microbiome of psyllids (Hemiptera: Psylloidea) in Aotearoa New Zealand.}, journal = {PloS one}, volume = {18}, number = {5}, pages = {e0285587}, doi = {10.1371/journal.pone.0285587}, pmid = {37186593}, issn = {1932-6203}, abstract = {The bacterial microbiome of psyllids has been studied for decades, with a strong focus on the primary and secondary endosymbionts capable of providing essential amino acids for the insects' diet and therefore playing a key role in the insects' ability to radiate on novel plant hosts. Here, we combine metabarcoding analysis of the bacterial communities hosted by psyllids with a multi-gene phylogenetic analysis of the insect hosts to determine what factors influence the bacterial diversity of the psyllids' microbiomes, especially in the context of the dispersal and evolutionary radiation of these insects in Aotearoa New Zealand. Using multi-gene phylogenetics with COI, 18S and EF-1α sequences from 102 psyllid species, we confirmed for the first time monophyly for all the six genera of native/endemic Aotearoa New Zealand psyllids, with indications that they derive from at least six dispersal events to the country. This also revealed that, after its ancestral arrival, the genus Powellia has radiated onto a larger and more diverse range of plants than either Psylla or Ctenarytaina, which is uncommon amongst monophyletic psyllids globally. DNA metabarcoding of the bacterial 16S gene here represents the largest dataset analysed to date from psyllids, including 246 individuals from 73 species. This provides novel evidence that bacterial diversity across psyllid species is strongly associated with psyllid phylogenetic structure, and to a lesser degree to their host plant association and geographic distribution. Furthermore, while the strongest co-phylogenetic signals were derived from the primary and secondary symbionts, a signal of phylosymbiosis was still retained among the remaining taxa of the bacterial microbiome, suggesting potential vertical transmission of bacterial lineages previously unknown to have symbiotic roles.}, }
@article {pmid37184407, year = {2023}, author = {Paulson, AR and Lougheed, SC and Huang, D and Colautti, RI}, title = {Multiomics Reveals Symbionts, Pathogens, and Tissue-Specific Microbiome of Blacklegged Ticks (Ixodes scapularis) from a Lyme Disease Hot Spot in Southeastern Ontario, Canada.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0140423}, doi = {10.1128/spectrum.01404-23}, pmid = {37184407}, issn = {2165-0497}, abstract = {Ticks in the family Ixodidae are important vectors of zoonoses, including Lyme disease (LD), which is caused by spirochete bacteria from the Borreliella (Borrelia) burgdorferi sensu lato complex. The blacklegged tick (Ixodes scapularis) continues to expand across Canada, creating hot spots of elevated LD risk at the leading edge of its expanding range. Current efforts to understand the risk of pathogen transmission associated with I. scapularis in Canada focus primarily on targeted screens, while natural variation in the tick microbiome remains poorly understood. Using multiomics consisting of 16S metabarcoding and ribosome-depleted, whole-shotgun RNA transcriptome sequencing, we examined the microbial communities associated with adult I. scapularis (n = 32), sampled from four tissue types (whole tick, salivary glands, midgut, and viscera) and three geographical locations within a LD hot spot near Kingston, Ontario, Canada. The communities consisted of both endosymbiotic and known or potentially pathogenic microbes, including RNA viruses, bacteria, and a Babesia sp. intracellular parasite. We show that β-diversity is significantly higher between the bacterial communities of individual tick salivary glands and midguts than that of whole ticks. Linear discriminant analysis effect size (LEfSe) determined that the three potentially pathogenic bacteria detected by V4 16S rRNA sequencing also differed among dissected tissues only, including a Borrelia strain from the B. burgdorferi sensu lato complex, Borrelia miyamotoi, and Anaplasma phagocytophilum. Importantly, we find coinfection of I. scapularis by multiple microbes, in contrast to diagnostic protocols for LD, which typically focus on infection from a single pathogen of interest (B. burgdorferi sensu stricto). IMPORTANCE As a vector of human health concern, blacklegged ticks (Ixodes scapularis) transmit pathogens that cause tick-borne diseases (TBDs), including Lyme disease (LD). Several hot spots of elevated LD risk have emerged across Canada as I. scapularis expands its range. Focusing on a hot spot in southeastern Ontario, we used high-throughput sequencing to characterize the microbiome of whole ticks and dissected salivary glands and midguts. Compared with whole ticks, salivary glands and midguts were more diverse and associated with distinct bacterial communities that are less dominated by Rickettsia endosymbiont bacteria and are enriched for pathogenic bacteria, including a B. burgdorferi sensu lato-associated Borrelia sp., Borrelia miyamotoi, and Anaplasma phagocytophilum. We also found evidence of coinfection of I. scapularis by multiple pathogens. Overall, our study highlights the challenges and opportunities associated with the surveillance of the microbiome of I. scapularis for pathogen detection using metabarcoding and metatranscriptome approaches.}, }
@article {pmid37178742, year = {2023}, author = {Yuan, F and Su, M and Li, T and Zhang, Y and Dietrich, CH and Webb, MD and Wei, C}, title = {Functional and evolutionary implications of protein and metal content of leafhopper brochosomes.}, journal = {Insect biochemistry and molecular biology}, volume = {}, number = {}, pages = {103962}, doi = {10.1016/j.ibmb.2023.103962}, pmid = {37178742}, issn = {1879-0240}, abstract = {Brochosomes derived from the specialized glandular segments of the Malpighian tubules (MTs) form superhydrophobic coatings for insects of Membracoidea, and have multiple hypothetical functions. However, the constituents, biosynthesis and evolutionary origin of brochosomes remain poorly understood. We investigated general chemical and physical characteristics of the integumental brochosomes (IBs) of the leafhopper Psammotettix striatus, determined the constituents of IBs, identified the unigenes involved in brochosomal protein synthesis, and investigated the potential associations among brochosomal protein synthesis, amino acid composition of food source, and the possible roles of endosymbionts in brochosome production. The results show that IBs are mainly composed of glycine- and tyrosine-rich proteins and some metal elements, which contain both essential and non-essential amino acids (EAAs and NEAAs) for insects, including EAAs deficient in the sole food source. All 12 unigenes involved in synthesizing the 12 brochosomal proteins (BPs) with high confidence are exclusively highly expressed in the glandular segment of MTs, confirming that brochosomes are synthesized by this segment. The synthesis of BPs is one of the key synapomorphies of Membracoidea but may be lost secondarily in a few lineages. The synthesis of BPs might be related to the symbiosis of leafhoppers/treehoppers with endosymbionts that provide these insects with EAAs, including those are deficient in the sole diet (i.e., plant sap) and could only be made available by the symbionts. We hypothesize that the functional modification of MTs have combined with the application of BPs enabling Membracoidea to colonize and adapt to novel ecological niches, and evolve to the dramatic diversification of this hemipteran group (in particular the family Cicadellidae). This study highlights the importance of evolutionary plasticity and multiple functions of MTs in driving the adaptations and evolution of sap-sucking insects of Hemiptera.}, }
@article {pmid37172511, year = {2023}, author = {Becker, NS and Rollins, RE and Stephens, R and Sato, K and Brachmann, A and Nakao, M and Kawabata, H}, title = {Candidatus Lariskella arthopodarum endosymbiont is the main factor differentiating the microbiome communities of female and male Borrelia-positive Ixodes persulcatus ticks.}, journal = {Ticks and tick-borne diseases}, volume = {14}, number = {4}, pages = {102183}, doi = {10.1016/j.ttbdis.2023.102183}, pmid = {37172511}, issn = {1877-9603}, abstract = {Ixodes persulcatus, a hard-bodied tick species primarily found in Asia and Eastern Europe, is a vector of pathogens to human and livestock hosts. Little research has been done on the microbiome of this species, especially using individual non-pooled samples and comparing different geographical locations. Here, we use 16S rRNA amplicon sequencing to determine the individual microbial composition of 85 Borrelia-positive I. persulcatus from the Japanese islands of Hokkaido and Honshu. The resulting data (164 unique OTUs) were further analyzed to compare the makeup and diversity of the microbiome by sex and location, as well as to determine the presence of human pathogens. We found that, while location had little influence, the diversity of I. persulcatus microbiome was predominantly dependent on sex. Males were seen to have higher microbiome diversity than females, likely due to the high presence of endosymbiotic Candidatus Lariskella arthropodarum within the female microbial communities. Furthermore, high read counts for five genera containing potentially human pathogenic species were detected among both male and female microbiomes: Ehrlichia, Borrelia, Rickettsia, Candidatus Neoehrlichia and Burkholderia and co-infections between different pathogens were frequent. We conclude that the microbiome of I. persulcatus depends mainly on sex and not geographical location and that the major difference between sexes is due to the high abundance of Ca. L. arthropodarum in females. We also stress the importance of this tick species as a vector of potential human pathogens frequently found in co-infections.}, }
@article {pmid37170316, year = {2021}, author = {Serra, V and D'Alessandro, A and Nitla, V and Gammuto, L and Modeo, L and Petroni, G and Fokin, SI}, title = {The neotypification of Frontonia vernalis (Ehrenberg, 1833) Ehrenberg, 1838 and the description of Frontonia paravernalis sp. nov. trigger a critical revision of frontoniid systematics.}, journal = {BMC zoology}, volume = {6}, number = {1}, pages = {4}, pmid = {37170316}, issn = {2056-3132}, abstract = {BACKGROUND: Among Oligohymenophorea (Ciliophora, Alveolata) the subclass Peniculia stands as one of the most well-known groups. Frontonia is the largest genus of Peniculia, and its representatives are spread in any type of water bodies as well as in soil. At a first glance, Frontonia species exhibit an overall similar morphology, and form a well-recognizable taxon of ciliates. Despite the general morphological homogeneity, the phylogenetic analysis based on the 18S rDNA sequencing showed that Frontonia is a non-monophyletic group. The systematics of this genus should be deeply reviewed, although additional issues complicate the task solving. First, type species of the genus is not yet clearly established, and no type material is available. In this context, the situation of F. vernalis, one of the first Frontonia ever described, is somehow puzzled: the description of this ciliate made by Ehrenberg (in 1833 and 1838) contains several inaccuracies and subsequent misidentifications by other authors occurred. Moreover, the 18S rDNA sequence of a putative F. vernalis is available on GenBank, but no morphological description of the correspondent specimens is provided; thus, in our opinion, it should be only prudently associated with F. vernalis or at least indicated as "F. vernalis".<br><br>RESULTS: In the present work, we provide the neotypification of F. vernalis newly found in Italy, presenting its multidisciplinary description and its neotype material. Similarly, we describe a novel species bearing Chlorella-like endosymbionts, Frontonia paravernalis sp. nov., retrieved in two far distant locations (Italy, Russia). A critical discussion on the status of Frontonia taxonomy and phylogeny is also presented, based on the 18S rDNA sequencing of both these two newly collected species and other 14 frontoniids isolated in different parts of the world. Finally, in the present study F. leucas was neotypified and proposed as the type species of the genus.<br><br>CONCLUSIONS: Green frontoniids form a monophyletic clade of freshwater organisms characterized by having a single contractile vacuole and bearing intracytoplasmatic Chlorella-like symbionts. With the neotypification of F. vernalis and F. leucas a fundamental step in Frontonia systematics was taken, and the bases for further taxonomic studies were laid.}, }
@article {pmid37160773, year = {2023}, author = {Yang, B and Xu, C and Cheng, Y and Jia, T and Hu, X}, title = {Research progress on the biosynthesis and delivery of iron-sulfur clusters in the plastid.}, journal = {Plant cell reports}, volume = {}, number = {}, pages = {}, pmid = {37160773}, issn = {1432-203X}, abstract = {Iron-sulfur (Fe-S) clusters are ancient protein cofactors ubiquitously exist in organisms. They are involved in many important life processes. Plastids are semi-autonomous organelles with a double membrane and it is believed to originate from a cyanobacterial endosymbiont. By learning form the research in cyanobacteria, a Fe-S cluster biosynthesis and delivery pathway has been proposed and partly demonstrated in plastids, including iron uptake, sulfur mobilization, Fe-S cluster assembly and delivery. Fe-S clusters are essential for the downstream Fe-S proteins to perform their normal biological functions. Because of the importance of Fe-S proteins in plastid, researchers have made a lot of research progress on this pathway in recent years. This review summarizes the detail research progress made in recent years. In addition, the scientific problems remained in this pathway are also discussed.}, }
@article {pmid37160764, year = {2023}, author = {Gimmi, E and Wallisch, J and Vorburger, C}, title = {Defensive symbiosis in the wild: Seasonal dynamics of parasitism risk and symbiont-conferred resistance.}, journal = {Molecular ecology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mec.16976}, pmid = {37160764}, issn = {1365-294X}, abstract = {Parasite-mediated selection can rapidly drive up resistance levels in host populations, but fixation of resistance traits may be prevented by costs of resistance. Black bean aphids (Aphis fabae) benefit from increased resistance to parasitoids when carrying the defensive bacterial endosymbiont Hamiltonella defensa. However, due to fitness costs that come with symbiont infection, symbiont-conferred resistance may result in either a net benefit or a net cost to the aphid host, depending on parasitoid presence as well as on the general ecological context. Balancing selection may therefore explain why in natural aphid populations, H. defensa is often found at intermediate frequencies. Here we present a 2-year field study where we set out to look for signatures of balancing selection in natural aphid populations. We collected temporally well-resolved data on the prevalence of H. defensa in A. f. fabae and estimated the risk imposed by parasitoids using sentinel hosts. Despite a marked and consistent early-summer peak in parasitism risk, and significant changes in symbiont prevalence over time, we found just a weak correlation between parasitism risk and H. defensa frequency dynamics. H. defensa prevalence in the populations under study was, in fact, better explained by the number of heat days that previous aphid generations were exposed to. Our study grants an unprecedentedly well-resolved insight into the dynamics of endosymbiont and parasitoid communities of A. f. fabae populations, and it adds to a growing body of empirical evidence suggesting that not only parasitism risk, but rather multifarious selection is shaping H. defensa prevalence in the wild.}, }
@article {pmid37147800, year = {2023}, author = {Zhang, Y and Tian, L and Lu, C}, title = {Chloroplast Gene Expression: Recent Advances and Perspectives.}, journal = {Plant communications}, volume = {}, number = {}, pages = {100611}, doi = {10.1016/j.xplc.2023.100611}, pmid = {37147800}, issn = {2590-3462}, abstract = {Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations to gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved the stage of describing phases of chloroplast gene expression to explore the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss the PPR protein engineering and its biotechnological impacts on chloroplast RNA research, new techniques for elucidating the molecular mechanisms of chloroplast gene expression, and some important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss the remaining biological and mechanistic questions to be answered in the future.}, }
@article {pmid37138629, year = {2023}, author = {Tan, Y and Gong, B and Zhang, Q and Li, C and Weng, J and Zhou, X and Jin, L}, title = {Diversity of endosymbionts in camellia spiny whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), estimated by 16S rRNA analysis and their biological implications.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1124386}, pmid = {37138629}, issn = {1664-302X}, abstract = {Camellia spiny whitefly, Aleurocanthus camelliae (Hemiptera: Aleyrodidae), is a major pest in tea, which poses a serious threat to tea production. Similar to many insects, various bacterial symbioses inside A. camelliae may participate in the reproduction, metabolism, and detoxification of the host. However, few reports included research on the microbial composition and influence on A. camelliae growth. We first applied high-throughput sequencing of the V4 region in the 16S rRNA of symbiotic bacteria to study its component and effect on the biological trait of A. camelliae by comparing it with the antibiotic treatment group. The population parameters, survival rate, and fecundity rate of A. camelliae were also analyzed using the age-stage two-sex life table. Our results demonstrated that phylum Proteobacteria (higher than 96.15%) dominated the whole life cycle of A. camelliae. It unveiled the presence of Candidatus Portiera (primary endosymbiont) (67.15-73.33%), Arsenophonus (5.58-22.89%), Wolbachia (4.53-11.58%), Rickettsia (0.75-2.59%), and Pseudomonas (0.99-1.88%) genus. Antibiotic treatment caused a significant decrease in the endosymbiont, which negatively affected the host's biological properties and life process. For example, 1.5% rifampicin treatment caused a longer preadult stage in the offspring generation (55.92 d) compared to the control (49.75d) and a lower survival rate (0.36) than the control (0.60). The decreased intrinsic rate of increase (r), net reproductive rate (R 0), and prolonged mean generation time (T) were signs of all disadvantageous effects associated with symbiotic reduction. Our findings confirmed the composition and richness of symbiotic bacteria in larva and adult of A. camelliae by an Illumina NovaSeq 6000 analysis and their influence on the development of the host by demographic research. Together, the results suggested that symbiotic bacteria play an important role in manipulating the biological development of their hosts, which might help us for developing new pest control agents and technologies for better management of A. camelliae.}, }
@article {pmid37133447, year = {2023}, author = {DeLong, JP and Van Etten, JL and Dunigan, DD}, title = {Lessons from Chloroviruses: the Complex and Diverse Roles of Viruses in Food Webs.}, journal = {Journal of virology}, volume = {}, number = {}, pages = {e0027523}, doi = {10.1128/jvi.00275-23}, pmid = {37133447}, issn = {1098-5514}, abstract = {Viruses can have large effects on the ecological communities in which they occur. Much of this impact comes from the mortality of host cells, which simultaneously alters microbial community composition and causes the release of matter that can be used by other organisms. However, recent studies indicate that viruses may be even more deeply integrated into the functioning of ecological communities than their effect on nutrient cycling suggests. In particular, chloroviruses, which infect chlorella-like green algae that typically occur as endosymbionts, participate in three types of interactions with other species. Chlororviruses (i) can lure ciliates from a distance, using them as a vector; (ii) depend on predators for access to their hosts; and (iii) get consumed as a food source by, at least, a variety of protists. Therefore, chloroviruses both depend on and influence the spatial structures of communities as well as the flows of energy through those communities, driven by predator-prey interactions. The emergence of these interactions are an eco-evolutionary puzzle, given the interdependence of these species and the many costs and benefits that these interactions generate.}, }
@article {pmid37121168, year = {2023}, author = {Biney, C and Graham, GE and Asiedu, E and Sakyi, SA and Kwarteng, A}, title = {Wolbachia Ferrochelatase as a potential drug target against filarial infections.}, journal = {Journal of molecular graphics &amp; modelling}, volume = {122}, number = {}, pages = {108490}, doi = {10.1016/j.jmgm.2023.108490}, pmid = {37121168}, issn = {1873-4243}, abstract = {Filarial infections are among the world's most disturbing diseases caused by 3 major parasitic worms; Onchocerca volvulus, Wuchereria bancrofti, and Brugia malayi, affecting more than 500 million people worldwide. Currently used drugs for mass drug administration (MDA) have been met with several challenges including the development of complications in individuals with filaria co-infections and parasitic drug resistance. The filarial endosymbiont, Wolbachia, has emerged as an attractive therapeutic target for filariasis elimination, due to the dependence of the filaria on this endosymbiont for survival. Here, we target an important enzyme in the Wolbachia heme biosynthetic pathway (ferrochelatase), using high-throughput virtual screening and molecular dynamics with MM-PBSA calculations. We identified four drug candidates; Nilotinib, Ledipasvir, 3-benzhydryloxy-8-methyl-8-azabicyclo[3.2.1]octane, and 2-(4-Amino-piperidin-1-yl)-ethanol as potential small molecules inhibitors as they could compete with the enzyme's natural substrate (Protoporphyrin IX) for active pocket binding. This prevents the worm from receiving the heme molecule from Wolbachia for their growth and survival, resulting in their death. This study which involved targeting enzymes in biosynthetic pathways of the parasitic worms' endosymbiont (Wolbachia), has proven to be an alternative therapeutic option leading to the discovery of new drugs, which will help facilitate the elimination of parasitic infections.}, }
@article {pmid37117399, year = {2023}, author = {Ghousein, A and Tutagata, J and Schrieke, H and Etienne, M and Chaumeau, V and Boyer, S and Pages, N and Roiz, D and Eren, AM and Cambray, G and Reveillaud, J}, title = {pWCP is a widely distributed and highly conserved Wolbachia plasmid in Culex pipiens and Culex quinquefasciatus mosquitoes worldwide.}, journal = {ISME communications}, volume = {3}, number = {1}, pages = {40}, pmid = {37117399}, issn = {2730-6151}, abstract = {Mosquitoes represent the most important pathogen vectors and are responsible for the spread of a wide variety of poorly treatable diseases. Wolbachia are obligate intracellular bacteria that are widely distributed among arthropods and collectively represents one of the most promising solutions for vector control. In particular, Wolbachia has been shown to limit the transmission of pathogens, and to dramatically affect the reproductive behavior of their host through its phage WO. While much research has focused on deciphering and exploring the biocontrol applications of these WO-related phenotypes, the extent and potential impact of the Wolbachia mobilome remain poorly appreciated. Notably, several Wolbachia plasmids, carrying WO-like genes and Insertion Sequences (IS), thus possibly interrelated to other genetic units of the endosymbiont, have been recently discovered. Here we investigated the diversity and biogeography of the first described plasmid of Wolbachia in Culex pipiens (pWCP) in several islands and continental countries around the world-including Cambodia, Guadeloupe, Martinique, Thailand, and Mexico-together with mosquito strains from colonies that evolved for 2 to 30 years in the laboratory. We used PCR and qPCR to determine the presence and copy number of pWCP in individual mosquitoes, and highly accurate Sanger sequencing to evaluate potential variations. Together with earlier observation, our results show that pWCP is omnipresent and strikingly conserved among Wolbachia populations within mosquitoes from distant geographies and environmental conditions. These data suggest a critical role for the plasmid in Wolbachia ecology and evolution, and the potential of a great tool for further genetic dissection and possible manipulation of this endosymbiont.}, }
@article {pmid37117271, year = {2023}, author = {Řezáč, M and Řezáčová, V and Gloríková, N and Némethová, E and Heneberg, P}, title = {Food provisioning to Pardosa spiders decreases the levels of tissue-resident endosymbiotic bacteria.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {6943}, pmid = {37117271}, issn = {2045-2322}, abstract = {The diversity, host specificity, and physiological effects of endosymbiotic bacteria in spiders (Araneae) are poorly characterized. We used 16S rDNA sequencing to evaluate endosymbionts in the cephalothorax and legs of a wolf spider Pardosa agrestis. We tested the effects of feeding once or twice daily with fruit flies, aphids, or starved and compared them to those of syntopically occurring Pardosa palustris. The feeding increased traveled distance up to five times in some of the groups provisioned with food relative to the starved control. The Shannon diversity t-test revealed significant differences between these component communities of the two spider species. The increased frequency of feeding with fruit flies, but not aphids, increased the dominance and decreased the alpha diversity of OTUs. The obligate or facultative endosymbionts were present in all analyzed spider individuals and were represented mostly by Rickettsiella, Rhabdochlamydia, Spiroplasma, and the facultative intracellular parasite Legionella. Vertically transmitted endosymbionts were less common, represented by Wolbachia pipientis and Rickettsia sp. H820. The relative abundance of Mycoplasma spp. was negatively correlated with provisioned or killed aphids. In conclusion, the tissues of Pardosa spiders host tremendously diverse assemblages of bacteria, including obligate or facultative endosymbionts, with yet unknown phenotypic effects.}, }
@article {pmid37116483, year = {2023}, author = {George, EE and Barcytė, D and Lax, G and Livingston, S and Tashyreva, D and Husnik, F and Lukeš, J and Eliáš, M and Keeling, PJ}, title = {A single cryptomonad cell harbors a complex community of organelles, bacteria, a phage, and selfish elements.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2023.04.010}, pmid = {37116483}, issn = {1879-0445}, abstract = {Symbiosis between prokaryotes and microbial eukaryotes (protists) has broadly impacted both evolution and ecology. Endosymbiosis led to mitochondria and plastids, the latter spreading across the tree of eukaryotes by subsequent rounds of endosymbiosis. Present-day endosymbionts in protists remain both common and diverse, although what function they serve is often unknown. Here, we describe a highly complex community of endosymbionts and a bacteriophage (phage) within a single cryptomonad cell. Cryptomonads are a model for organelle evolution because their secondary plastid retains a relict endosymbiont nucleus, but only one previously unidentified Cryptomonas strain (SAG 25.80) is known to harbor bacterial endosymbionts. We carried out electron microscopy and FISH imaging as well as genomic sequencing on Cryptomonas SAG 25.80, which revealed a stable, complex community even after over 50 years in continuous cultivation. We identified the host strain as Cryptomonas gyropyrenoidosa, and sequenced genomes from its mitochondria, plastid, and nucleomorph (and partially its nucleus), as well as two symbionts, Megaira polyxenophila and Grellia numerosa, and one phage (MAnkyphage) infecting M. polyxenophila. Comparing closely related endosymbionts from other hosts revealed similar metabolic and genomic features, with the exception of abundant transposons and genome plasticity in M. polyxenophila from Cryptomonas. We found an abundance of eukaryote-interacting genes as well as many toxin-antitoxin systems, including in the MAnkyphage genome that also encodes several eukaryotic-like proteins. Overall, the Cryptomonas cell is an endosymbiotic conglomeration with seven distinct evolving genomes that all show evidence of inter-lineage conflict but nevertheless remain stable, even after more than 4,000 generations in culture.}, }
@article {pmid37110360, year = {2023}, author = {Van Houten, J}, title = {A Review for the Special Issue on Paramecium as a Modern Model Organism.}, journal = {Microorganisms}, volume = {11}, number = {4}, pages = {}, doi = {10.3390/microorganisms11040937}, pmid = {37110360}, issn = {2076-2607}, abstract = {This review provides background and perspective for the articles contributing to the Special Issue of MDPI Micro-organisms on Paramecium as a Modern Model Organism. The six articles cover a variety of topics, each taking advantage of an important aspect of Paramecium biology: peripheral surface proteins that are developmentally regulated, endosymbiont algae and bacteria, ion channel regulation by calmodulin, regulation of cell mating reactivity and senescence, and the introns that dwell in the large genome. Each article highlights a significant aspect of Paramecium and its versatility.}, }
@article {pmid37103216, year = {2023}, author = {Lv, N and Peng, J and He, ZQ and Wen, Q and Su, ZQ and Ali, S and Liu, CZ and Qiu, BL}, title = {The Dynamic Distribution of Wolbachia and Rickettsia in AsiaII1 Bemisia tabaci.}, journal = {Insects}, volume = {14}, number = {4}, pages = {}, doi = {10.3390/insects14040401}, pmid = {37103216}, issn = {2075-4450}, abstract = {Wolbachia and Rickettsia are bacterial endosymbionts that can induce a number of reproductive abnormalities in their arthropod hosts. We screened and established the co-infection of Wolbachia and Rickettsia in Bemisia tabaci and compared the spatial and temporal distribution of Wolbachia and Rickettsia in eggs (3-120 h after spawning), nymphs, and adults of B. tabaci by qPCR quantification and fluorescent in situ hybridization (FISH). The results show that the titer of Wolbachia and Rickettsia in the 3-120 h old eggs showed a "w" patterned fluctuation, while the titers of Wolbachia and Rickettsia had a "descending-ascending descending-ascending" change process. The titers of Rickettsia and Wolbachia nymphal and the adult life stages of Asia II1 B. tabaci generally increased with the development of whiteflies. However, the location of Wolbachia and Rickettsia in the egg changed from egg stalk to egg base, and then from egg base to egg posterior, and finally back to the middle of the egg. These results will provide basic information on the quantity and localization of Wolbachia and Rickettsia within different life stages of B. tabaci. These findings help to understand the dynamics of the vertical transmission of symbiotic bacteria.}, }
@article {pmid37103129, year = {2023}, author = {Li, J and An, Z and Luo, J and Zhu, X and Wang, L and Zhang, K and Li, D and Ji, J and Niu, L and Gao, X and Cui, J}, title = {Parasitization of Aphis gossypii Glover by Binodoxys communis Gahan Causes Shifts in the Ovarian Bacterial Microbiota.}, journal = {Insects}, volume = {14}, number = {4}, pages = {}, doi = {10.3390/insects14040314}, pmid = {37103129}, issn = {2075-4450}, abstract = {BACKGROUND: Aphis gossypii Glover is an important agricultural pest distributed worldwide. Binodoxys communis Gahan is the main parasitoid wasp of A. gossypii. Previous studies have shown that parasitization causes reduced egg production in A. gossypii, but the effects of parasitism on the symbiotic bacteria in the host ovaries are unknown.<br><br>RESULTS: In this study, we analyzed the microbial communities in the ovaries of A. gossypii without and after parasitization. Whether parasitized or not, Buchnera was the dominant genus of symbiotic bacteria in the ovaries, followed by facultative symbionts including Arsenophonus, Pseudomonas, and Acinetobacter. The relative abundance of Buchnera in the aphid ovary increased after parasitization for 1 d in both third-instar nymph and adult stages, but decreased after parasitization for 3 d. The shifts in the relative abundance of Arsenophonus in both stages were the same as those observed for Buchnera. In addition, the relative abundance of Serratia remarkably decreased after parasitization for 1 d and increased after parasitization for 3 d. A functional predictive analysis of the control and parasitized ovary microbiomes revealed that pathways primarily enriched in parasitization were "amino acid transport and metabolism" and "energy production and conversion." Finally, RT-qPCR analysis was performed on Buchnera, Arsenophonus, and Serratia. The results of RT-qPCR were the same as the results of 16S rDNA sequencing.<br><br>CONCLUSIONS: These results provide a framework for investigating shifts in the microbial communities in host ovaries, which may be responsible for reduced egg production in aphids. These findings also broaden our understanding of the interactions among aphids, parasitoid wasps, and endosymbionts.}, }
@article {pmid37100405, year = {2023}, author = {Jaffe, AL and Castelle, CJ and Banfield, JF}, title = {Habitat Transition in the Evolution of Bacteria and Archaea.}, journal = {Annual review of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1146/annurev-micro-041320-032304}, pmid = {37100405}, issn = {1545-3251}, abstract = {Related groups of microbes are widely distributed across Earth's habitats, implying numerous dispersal and adaptation events over evolutionary time. However, relatively little is known about the characteristics and mechanisms of these habitat transitions, particularly for populations that reside in animal microbiomes. Here, we review the literature concerning habitat transitions among a variety of bacterial and archaeal lineages, considering the frequency of migration events, potential environmental barriers, and mechanisms of adaptation to new physicochemical conditions, including the modification of protein inventories and other genomic characteristics. Cells dependent on microbial hosts, particularly bacteria from the Candidate Phyla Radiation, have undergone repeated habitat transitions from environmental sources into animal microbiomes. We compare their trajectories to those of both free-living cells-including the Melainabacteria, Elusimicrobia, and methanogenic archaea-and cellular endosymbionts and bacteriophages, which have made similar transitions. We conclude by highlighting major related topics that may be worthy of future study. Expected final online publication date for the Annual Review of Microbiology, Volume 77 is September 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.}, }
@article {pmid37101136, year = {2023}, author = {Mosquera, KD and Martínez Villegas, LE and Rocha Fernandes, G and Rocha David, M and Maciel-de-Freitas, R and A Moreira, L and Lorenzo, MG}, title = {Egg-laying by female Aedes aegypti shapes the bacterial communities of breeding sites.}, journal = {BMC biology}, volume = {21}, number = {1}, pages = {97}, pmid = {37101136}, issn = {1741-7007}, abstract = {BACKGROUND: Aedes aegypti, the main arboviral mosquito vector, is attracted to human dwellings and makes use of human-generated breeding sites. Past research has shown that bacterial communities associated with such sites undergo compositional shifts as larvae develop and that exposure to different bacteria during larval stages can have an impact on mosquito development and life-history traits. Based on these facts, we hypothesized that female Ae. aegypti shape the bacteria communities of breeding sites during oviposition as a form of niche construction to favor offspring fitness.<br><br>RESULTS: To test this hypothesis, we first verified that gravid females can act as mechanical vectors of bacteria. We then elaborated an experimental scheme to test the impact of oviposition on breeding site microbiota. Five different groups of experimental breeding sites were set up with a sterile aqueous solution of larval food, and subsequently exposed to (1) the environment alone, (2) surface-sterilized eggs, (3) unsterilized eggs, (4) a non-egg laying female, or (5) oviposition by a gravid female. The microbiota of these differently treated sites was assessed by amplicon-oriented DNA sequencing once the larvae from the sites with eggs had completed development and formed pupae. Microbial ecology analyses revealed significant differences between the five treatments in terms of diversity. In particular, between-treatment shifts in abundance profiles were detected, showing that females induce a significant decrease in microbial alpha diversity through oviposition. In addition, indicator species analysis pinpointed bacterial taxa with significant predicting values and fidelity coefficients for the samples in which single females laid eggs. Furthermore, we provide evidence regarding how one of these indicator taxa, Elizabethkingia, exerts a positive effect on the development and fitness of mosquito larvae.<br><br>CONCLUSIONS: Ovipositing females impact the composition of the microbial community associated with a breeding site, promoting certain bacterial taxa over those prevailing in the environment. Among these bacteria, we found known mosquito symbionts and showed that they can improve offspring fitness if present in the water where eggs are laid. We deem this oviposition-mediated bacterial community shaping as a form of niche construction initiated by the gravid female.}, }
@article {pmid37098937, year = {2023}, author = {Arai, H and Takamatsu, T and Lin, SR and Mizutani, T and Omatsu, T and Katayama, Y and Nakai, M and Kunimi, Y and Inoue, MN}, title = {Diverse Molecular Mechanisms Underlying Microbe-Inducing Male Killing in the Moth Homona magnanima.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0209522}, doi = {10.1128/aem.02095-22}, pmid = {37098937}, issn = {1098-5336}, abstract = {Male killing (MK) is a type of reproductive manipulation induced by microbes, where sons of infected mothers are killed during development. MK is a strategy that enhances the fitness of the microbes, and the underlying mechanisms and the process of their evolution have attracted substantial attention. Homona magnanima, a moth, harbors two embryonic MK bacteria, namely, Wolbachia (Alphaproteobacteria) and Spiroplasma (Mollicutes), and a larval MK virus, Osugoroshi virus (OGV; Partitiviridae). However, whether the three distantly related male killers employ similar or different mechanisms to accomplish MK remains unknown. Here, we clarified the differential effects of the three male killers on the sex-determination cascades and development of H. magnanima males. Reverse transcription-PCR demonstrated that Wolbachia and Spiroplasma, but not OGVs, disrupted the sex-determination cascade of males by inducing female-type splice variants of doublesex (dsx), a downstream regulator of the sex-determining gene cascade. We also found that MK microbes altered host transcriptomes in different manners; Wolbachia impaired the host dosage compensation system, whereas Spiroplasma and OGVs did not. Moreover, Wolbachia and Spiroplasma, but not OGVs, triggered abnormal apoptosis in male embryos. These findings suggest that distantly related microbes employ distinct machineries to kill males of the identical host species, which would be the outcome of the convergent evolution. IMPORTANCE Many microbes induce male killing (MK) in various insect species. However, it is not well understood whether microbes adopt similar or different MK mechanisms. This gap in our knowledge is partly because different insect models have been examined for each MK microbe. Here, we compared three taxonomically distinct male killers (i.e., Wolbachia, Spiroplasma, and a partiti-like virus) that infect the same host. We provided evidence that microbes can cause MK through distinct mechanisms that differ in the expression of genes involved in sex determination, dosage compensation, and apoptosis. These results imply independent evolutionary scenarios for the acquisition of their MK ability.}, }
@article {pmid37098535, year = {2023}, author = {da Moura, AJF and Valadas, V and Da Veiga Leal, S and Montalvo Sabino, E and Sousa, CA and Pinto, J}, title = {Screening of natural Wolbachia infection in mosquitoes (Diptera: Culicidae) from the Cape Verde islands.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {142}, pmid = {37098535}, issn = {1756-3305}, abstract = {BACKGROUND: Wolbachia pipientis is an endosymbiont bacterium that induces cytoplasmic incompatibility and inhibits arboviral replication in mosquitoes. This study aimed to assess Wolbachia prevalence and genetic diversity in different mosquito species from Cape Verde.<br><br>METHODS: Mosquitoes were collected on six islands of Cape Verde and identified to species using morphological keys and PCR-based assays. Wolbachia was detected by amplifying a fragment of the surface protein gene (wsp). Multilocus sequence typing (MLST) was performed with five housekeeping genes (coxA, gatB, ftsZ, hcpA, and fbpA) and the wsp hypervariable region (HVR) for strain identification. Identification of wPip groups (wPip-I to wPip-V) was performed using PCR-restriction fragment length polymorphism (RFLP) assay on the ankyrin domain gene pk1.<br><br>RESULTS: Nine mosquito species were collected, including the major vectors Aedes aegypti, Anopheles arabiensis, Culex pipiens sensu stricto, and Culex quinquefasciatus. Wolbachia was only detected in Cx. pipiens s.s. (100% prevalence), Cx. quinquefasciatus (98.3%), Cx. pipiens/quinquefasciatus hybrids (100%), and Culex tigripes (100%). Based on the results of MLST and wsp hypervariable region typing, Wolbachia from the Cx. pipiens complex was assigned to sequence type 9, wPip clade, and supergroup B. PCR/RFLP analysis revealed three wPip groups in Cape Verde, namely wPip-II, wPip-III, and wPip-IV. wPip-IV was the most prevalent, while wPip-II and wPip-III were found only on Maio and Fogo islands. Wolbachia detected in Cx. tigripes belongs to supergroup B, with no attributed MLST profile, indicating a new strain of Wolbachia in this mosquito species.<br><br>CONCLUSIONS: A high prevalence and diversity of Wolbachia was found in species from the Cx. pipiens complex. This diversity may be related to the mosquito's colonization history on the Cape Verde islands. To the best of our knowledge, this is the first study to detect Wolbachia in Cx. tigripes, which may provide an additional opportunity for biocontrol initiatives.}, }
@article {pmid37094805, year = {2023}, author = {Goldstein, EB and de Anda Acosta, Y and Henry, LM and Parker, BJ}, title = {Variation in density, immune gene suppression, and co-infection outcomes among strains of the aphid endosymbiont Regiella insecticola.}, journal = {Evolution; international journal of organic evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/evolut/qpad071}, pmid = {37094805}, issn = {1558-5646}, abstract = {Many insects harbor heritable microbes that influence host phenotypes. Symbiont strains establish at different densities within hosts. This variation is important evolutionarily because within-host density has been linked to the costs and benefits of the symbiosis for both partners. Studying the factors shaping within-host density is important to our broader understanding of host-microbe coevolution. Here we focused on different strains of Regiella insecticola, a facultative symbiont of aphids. We first showed that strains of Regiella establish in pea aphids at drastically different densities. We then found that variation in density is correlated with the expression levels of two key insect immune system genes (phenoloxidase and hemocytin), with the suppression of immune gene expression correlating with higher Regiella density. We then performed an experiment where we established co-infections of a higher- and a lower-density Regiella strain, and we showed that the higher-density strain is better able to persist in co-infections than the lower-density strain. Together, our results point to a potential mechanism that contributes to strain-level variation in symbiont density in this system, and our data suggest that symbiont fitness may be increased by establishing at higher density within hosts. Our work highlights the importance of within-host dynamics shaping symbiont evolution.}, }
@article {pmid37094148, year = {2023}, author = {Gu, X and Ross, PA and Gill, A and Yang, Q and Ansermin, E and Sharma, S and Soleimannejad, S and Sharma, K and Callahan, A and Brown, C and Umina, PA and Kristensen, TN and Hoffmann, AA}, title = {A rapidly spreading deleterious aphid endosymbiont that uses horizontal as well as vertical transmission.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {18}, pages = {e2217278120}, doi = {10.1073/pnas.2217278120}, pmid = {37094148}, issn = {1091-6490}, abstract = {Endosymbiotic bacteria that live inside the cells of insects are typically only transmitted maternally and can spread by increasing host fitness and/or modifying reproduction in sexual hosts. Transinfections of Wolbachia endosymbionts are now being used to introduce useful phenotypes into sexual host populations, but there has been limited progress on applications using other endosymbionts and in asexual populations. Here, we develop a unique pathway to application in aphids by transferring the endosymbiont Rickettsiella viridis to the major crop pest Myzus persicae. Rickettsiella infection greatly reduced aphid fecundity, decreased heat tolerance, and modified aphid body color, from light to dark green. Despite inducing host fitness costs, Rickettsiella spread rapidly through caged aphid populations via plant-mediated horizontal transmission. The phenotypic effects of Rickettsiella were sensitive to temperature, with spread only occurring at 19 °C and not 25 °C. Body color modification was also lost at high temperatures despite Rickettsiella maintaining a high density. Rickettsiella shows the potential to spread through natural M. persicae populations by horizontal transmission and subsequent vertical transmission. Establishment of Rickettsiella in natural populations could reduce crop damage by modifying population age structure, reducing population growth and providing context-dependent effects on host fitness. Our results highlight the importance of plant-mediated horizontal transmission and interactions with temperature as drivers of endosymbiont spread in asexual insect populations.}, }
@article {pmid37085551, year = {2023}, author = {Kiefer, JST and Bauer, E and Okude, G and Fukatsu, T and Kaltenpoth, M and Engl, T}, title = {Cuticle supplementation and nitrogen recycling by a dual bacterial symbiosis in a family of xylophagous beetles.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {37085551}, issn = {1751-7370}, abstract = {Many insects engage in stable nutritional symbioses with bacteria that supplement limiting essential nutrients to their host. While several plant sap-feeding Hemipteran lineages are known to be simultaneously associated with two or more endosymbionts with complementary biosynthetic pathways to synthesize amino acids or vitamins, such co-obligate symbioses have not been functionally characterized in other insect orders. Here, we report on the characterization of a dual co-obligate, bacteriome-localized symbiosis in a family of xylophagous beetles using comparative genomics, fluorescence microscopy, and phylogenetic analyses. Across the beetle family Bostrichidae, most investigated species harbored the Bacteroidota symbiont Shikimatogenerans bostrichidophilus that encodes the shikimate pathway to produce tyrosine precursors in its severely reduced genome, likely supplementing the beetles' cuticle biosynthesis, sclerotisation, and melanisation. One clade of Bostrichid beetles additionally housed the co-obligate symbiont Bostrichicola ureolyticus that is inferred to complement the function of Shikimatogenerans by recycling urea and provisioning the essential amino acid lysine, thereby providing additional benefits on nitrogen-poor diets. Both symbionts represent ancient associations within the Bostrichidae that have subsequently experienced genome erosion and co-speciation with their hosts. While Bostrichicola was repeatedly lost, Shikimatogenerans has been retained throughout the family and exhibits a perfect pattern of co-speciation. Our results reveal that co-obligate symbioses with complementary metabolic capabilities occur beyond the well-known sap-feeding Hemiptera and highlight the importance of symbiont-mediated cuticle supplementation and nitrogen recycling for herbivorous beetles.}, }
@article {pmid37079598, year = {2023}, author = {Choubdar, N and Karimian, F and Koosha, M and Nejati, J and Shabani Kordshouli, R and Azarm, A and Oshaghi, MA}, title = {Wolbachia infection in native populations of Blattella germanica and Periplaneta americana.}, journal = {PloS one}, volume = {18}, number = {4}, pages = {e0284704}, doi = {10.1371/journal.pone.0284704}, pmid = {37079598}, issn = {1932-6203}, abstract = {Cockroaches are significant pests worldwide, being important in medical, veterinary, and public health fields. Control of cockroaches is difficult because they have robust reproductive ability and high adaptability and are resistant to many insecticides. Wolbachia is an endosymbiont bacterium that infects the reproductive organs of approximately 70% of insect species and has become a promising biological agent for controlling insect pests. However, limited data on the presence or strain typing of Wolbachia in cockroaches are available. PCR amplification and sequencing of the wsp and gltA genes were used to study the presence, prevalence and molecular typing of Wolbachia in two main cockroach species, Blattella germanica (German cockroach) and Periplaneta americana (American cockroach), from different geographical locations of Iran. The Wolbachia endosymbiont was found only in 20.6% of German cockroaches while it was absent in American cockroach samples. Blast search and phylogenetic analysis revealed that the Wolbachia strain found in the German cockroach belongs to Wolbachia supergroup F. Further studies should investigate the symbiotic role of Wolbachia in cockroaches and determine whether lack of Wolbachia infection may increase this insect's ability to tolerate or acquire various pathogens. Results of our study provide a foundation for continued work on interactions between cockroaches, bacterial endosymbionts, and pathogens.}, }
@article {pmid37075471, year = {2023}, author = {Che Lah, EF and Ahamad, M and Dmitry, A and Md Zain, BM and Yaakop, S}, title = {Metagenomic profile of the bacterial communities associated with Ixodes granulatus (Acari: Ixodidae): a potential vector of tick-borne diseases.}, journal = {Journal of medical entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jme/tjad044}, pmid = {37075471}, issn = {1938-2928}, abstract = {Ixodes granulatus Supino, 1897 (Acari: Ixodida) is one of Malaysia's most common hard ticks and is a potential vector for tick-borne diseases (TBDs). Despite its great public health importance, research on I. granulatus microbial communities remains largely unexplored. Therefore, this study aimed to investigate the bacterial communities of on-host I. granulatus collected from three different recreational areas on the East Coast of Peninsular Malaysia using high throughput Next Generation Sequencing (NGS). A total of 9 females on-host I. granulatus were subjected to metabarcoding analysis targeting V3-V4 regions of 16S ribosomal RNA (rRNA) using the Illumina MiSeq platform. This study identified 15 bacterial phyla corresponding to 19 classes, 54 orders, and 90 families from 435 amplicon sequence variants (ASVs), revealing a diverse bacterial community profile. Together with 130 genera assigned, local I. granulatus harbored 4 genera of pathogens, i.e., Rickettsia da Rocha Lima, 1916 (Rickettsiales: Rickettsiaceae) (58.6%), Borrelia Swellengrebel 1907 (Spirochaetales: Borreliaceae) (31.6%), Borreliella Adeolu and Gupta 2015 (Spirochaetales: Borreliaceae) (0.6%), and Ehrlichia Cowdria Moshkovski 1947 (Rickettsiales: Ehrlichiaceae) (39.9%). Some endosymbiont bacteria, such as Coxiella (Philip, 1943) (Legionellales: Coxiellaceae), Wolbachia Hertig 1936 (Rickettsiales: Ehrlichiaceae), and Rickettsiella Philip, 1956 (Legionellales: Coxiellaceae), were also detected at very low abundance. Interestingly, this study reported the co-infection of Borrelia and Ehrlichia for the first time, instilling potential health concerns in the context of co-transmission to humans, especially in areas with a high population of I. granulatus. This study successfully characterized the tick microbiome and provided the first baseline data of I. granulatus bacterial communities in Malaysia. These results support the need for way-forward research on tick-associated bacteria using NGS, focusing on medically important species toward TBD prevention.}, }
@article {pmid37071674, year = {2023}, author = {Libby, E and Kempes, CP and Okie, JG}, title = {Metabolic compatibility and the rarity of prokaryote endosymbioses.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {17}, pages = {e2206527120}, doi = {10.1073/pnas.2206527120}, pmid = {37071674}, issn = {1091-6490}, abstract = {The evolution of the mitochondria was a significant event that gave rise to the eukaryotic lineage and most large complex life. Central to the origins of the mitochondria was an endosymbiosis between prokaryotes. Yet, despite the potential benefits that can stem from a prokaryotic endosymbiosis, their modern occurrence is exceptionally rare. While many factors may contribute to their rarity, we lack methods for estimating the extent to which they constrain the appearance of a prokaryotic endosymbiosis. Here, we address this knowledge gap by examining the role of metabolic compatibility between a prokaryotic host and endosymbiont. We use genome-scale metabolic flux models from three different collections (AGORA, KBase, and CarveMe) to assess the viability, fitness, and evolvability of potential prokaryotic endosymbioses. We find that while more than half of host-endosymbiont pairings are metabolically viable, the resulting endosymbioses have reduced growth rates compared to their ancestral metabolisms and are unlikely to gain mutations to overcome these fitness differences. In spite of these challenges, we do find that they may be more robust in the face of environmental perturbations at least in comparison with the ancestral host metabolism lineages. Our results provide a critical set of null models and expectations for understanding the forces that shape the structure of prokaryotic life.}, }
@article {pmid37067424, year = {2023}, author = {Chakraborty, A and Šobotník, J and Votýpková, K and Hradecký, J and Stiblik, P and Synek, J and Bourguignon, T and Baldrian, P and Engel, MS and Novotný, V and Odriozola, I and Větrovský, T}, title = {Impact of Wood Age on Termite Microbial Assemblages.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0036123}, doi = {10.1128/aem.00361-23}, pmid = {37067424}, issn = {1098-5336}, abstract = {The decomposition of wood and detritus is challenging to most macroscopic organisms due to the recalcitrant nature of lignocellulose. Moreover, woody plants often protect themselves by synthesizing toxic or nocent compounds which infuse their tissues. Termites are essential wood decomposers in warmer terrestrial ecosystems and, as such, they have to cope with high concentrations of plant toxins in wood. In this paper, we evaluated the influence of wood age on the gut microbial (bacterial and fungal) communities associated with the termites Reticulitermes flavipes (Rhinotermitidae) (Kollar, 1837) and Microcerotermes biroi (Termitidae) (Desneux, 1905). We confirmed that the secondary metabolite concentration decreased with wood age. We identified a core microbial consortium maintained in the gut of R. flavipes and M. biroi and found that its diversity and composition were not altered by the wood age. Therefore, the concentration of secondary metabolites had no effect on the termite gut microbiome. We also found that both termite feeding activities and wood age affect the wood microbiome. Whether the increasing relative abundance of microbes with termite activities is beneficial to the termites is unknown and remains to be investigated. IMPORTANCE Termites can feed on wood thanks to their association with their gut microbes. However, the current understanding of termites as holobiont is limited. To our knowledge, no studies comprehensively reveal the influence of wood age on the termite-associated microbial assemblage. The wood of many tree species contains high concentrations of plant toxins that can vary with their age and may influence microbes. Here, we studied the impact of Norway spruce wood of varying ages and terpene concentrations on the microbial communities associated with the termites Reticulitermes flavipes (Rhinotermitidae) and Microcerotermes biroi (Termitidae). We performed a bacterial 16S rRNA and fungal ITS2 metabarcoding study to reveal the microbial communities associated with R. flavipes and M. biroi and their impact on shaping the wood microbiome. We noted that a stable core microbiome in the termites was unaltered by the feeding substrate, while termite activities influenced the wood microbiome, suggesting that plant secondary metabolites have negligible effects on the termite gut microbiome. Hence, our study shed new insights into the termite-associated microbial assemblage under the influence of varying amounts of terpene content in wood and provides a groundwork for future investigations for developing symbiont-mediated termite control measures.}, }
@article {pmid37066385, year = {2023}, author = {Moulin, SLY and Frail, S and Doenier, J and Braukmann, T and Yeh, E}, title = {The endosymbiont of Epithemia clementina is specialized for nitrogen fixation within a photosynthetic eukaryote.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.08.531752}, pmid = {37066385}, abstract = {Epithemia spp. diatoms contain obligate, nitrogen-fixing endosymbionts, or "diazoplasts", derived from cyanobacteria. These algae are a rare example of photosynthetic eukaryotes that have successfully coupled oxygenic photosynthesis with oxygen-sensitive nitrogenase activity. Here, we report a newly-isolated species, E. clementina , as a model to investigate endosymbiotic acquisition of nitrogen fixation. To detect the metabolic changes associated with endosymbiotic specialization, we compared nitrogen fixation, associated carbon and nitrogen metabolism, and their regulatory pathways in the Epithemia diazoplast with its close, free-living cyanobacterial relative, Crocosphaera subtropica . Unlike C. subtropica , we show that nitrogenase activity in the diazoplast is concurrent with, and even dependent on, host photosynthesis and no longer associated with cyanobacterial glycogen storage suggesting carbohydrates are imported from the host diatom. Carbohydrate catabolism in the diazoplast indicates that the oxidative pentose pathway and oxidative phosphorylation, in concert, generates reducing equivalents and ATP and consumes oxygen to support nitrogenase activity. In contrast to expanded nitrogenase activity, the diazoplast has diminished ability to utilize alternative nitrogen sources. Upon ammonium repletion, negative feedback regulation of nitrogen fixation was conserved, however ammonia assimilation showed paradoxical responses in the diazoplast compared with C. subtropica . The altered nitrogen regulation likely favors nitrogen transfer to the host. Our results suggest that the diazoplast is specialized for endosymbiotic nitrogen fixation. Altogether, we establish a new model for studying endosymbiosis, perform the first functional characterization of this diazotroph endosymbiosis, and identify metabolic adaptations for endosymbiotic acquisition of a critical biological function.}, }
@article {pmid37052365, year = {2023}, author = {Xu, J and Tan, JB and Li, YD and Xu, YH and Tang, A and Zhou, HK and Shi, PQ}, title = {Diversity and dynamics of endosymbionts in a single population of sweet potato weevil, Cylas formicarius (Coleoptera: Brentidae): a preliminary study.}, journal = {Journal of insect science (Online)}, volume = {23}, number = {2}, pages = {}, doi = {10.1093/jisesa/iead021}, pmid = {37052365}, issn = {1536-2442}, abstract = {Endosymbionts live symbiotically with insect hosts and play important roles in the evolution, growth, development, reproduction, and environmental fitness of hosts. Weevils are one of the most abundant insect groups that can be infected by various endosymbionts, such as Sodalis, Nardonella, and Wolbachia. The sweet potato weevil, Cylas formicarius (Coleoptera: Brentidae), is a notorious pest in sweet potato (Ipomoea batatas L.) cultivation. Currently, little is known about the presence of endosymbionts in C. formicarius. Herein, we assessed the endosymbiont load of a single geographic population of C. formicarius. The results showed that Nardonella and Rickettsia could infect C. formicarius at different rates, which also varied according to the developmental stages of C. formicarius. The relative titer of Nardonella was significantly related to C. formicarius developmental stages. The Nardonella-infecting sweet potato weevils were most closely related to the Nardonella in Sphenophorus levis (Coleoptera, Curculionidae). The Rickettsia be identified in bellii group. These results preliminarily revealed the endosymbionts in C. formicarius and helped to explore the diversity of endosymbionts in weevils and uncover the physiological roles of endosymbionts in weevils.}, }
@article {pmid37042290, year = {2023}, author = {Lu, M and Chen, S and Meng, C and Wang, W and Li, H and Sun, Y and Li, M and Ma, X and Ma, Y and Duan, C and Li, K}, title = {A novel Rickettsia species closely related to Rickettsia felis in Anopheles mosquitoes from Yingkou City, Northeast China.}, journal = {Zoonoses and public health}, volume = {}, number = {}, pages = {}, doi = {10.1111/zph.13043}, pmid = {37042290}, issn = {1863-2378}, abstract = {Mosquitoes are generally recognized as the most important vector of many zoonotic pathogens. In this study, seven mosquitoes species were identified (Anopheles pullus, Anopheles sinensis, Anopheles lesteri, Anopheles kleini, Ochlerotatus dorsalis, Aedes koreicus and Culex inatomii) in samples collected from Yingkou City, Liaoning Province, Northeastern China. A novel Rickettsia species was detected in Anopheles sinensis (two of 71, 2.82%) and Anopheles pullus (one of 106, 0.94%) mosquitoes. Genetic analysis indicated that the rrs and ompB genes have highest 99.60% and 97.88%-98.14% identities to Rickettsia felis, an emerging human pathogen of global concern mainly harboured by fleas, mosquitoes and booklice. The gltA sequences of these strains have 99.72% of nucleotide similarity with Rickettsia endosymbiont of Medetera jacula. The groEL sequences have 98.37% similarity to both Rickettsia tillamookensis and Rickettsia australis. The htrA sequences have 98.77% similarity to Rickettsia lusitaniae. In the phylogenetic tree based on concatenated nucleotide sequences of rrs, gltA, groEL, ompB and htrA genes, these strains are closely related to R. felis. Herein, we name it 'Candidatus Rickettsia yingkouensis'. Its human pathogenicity to humans and animals is still to be determined.}, }
@article {pmid37035680, year = {2023}, author = {Ferrarini, MG and Vallier, A and Dell'Aglio, E and Balmand, S and Vincent-Monégat, C and Debbache, M and Maire, J and Parisot, N and Zaidman-Rémy, A and Heddi, A and Rebollo, R}, title = {Endosymbiont-containing germarium transcriptional survey in a cereal weevil depicts downregulation of immune effectors at the onset of sexual maturity.}, journal = {Frontiers in physiology}, volume = {14}, number = {}, pages = {1142513}, pmid = {37035680}, issn = {1664-042X}, abstract = {Insects often establish long-term relationships with intracellular symbiotic bacteria, i.e., endosymbionts, that provide them with essential nutrients such as amino acids and vitamins. Endosymbionts are typically confined within specialized host cells called bacteriocytes that may form an organ, the bacteriome. Compartmentalization within host cells is paramount for protecting the endosymbionts and also avoiding chronic activation of the host immune system. In the cereal weevil Sitophilus oryzae, bacteriomes are present as a single organ at the larval foregut-midgut junction, and in adults, at the apex of midgut mesenteric caeca and at the apex of the four ovarioles. While the adult midgut endosymbionts experience a drastic proliferation during early adulthood followed by complete elimination through apoptosis and autophagy, ovarian endosymbionts are maintained throughout the weevil lifetime by unknown mechanisms. Bacteria present in ovarian bacteriomes are thought to be involved in the maternal transmission of endosymbionts through infection of the female germline, but the exact mode of transmission is not fully understood. Here, we show that endosymbionts are able to colonize the germarium in one-week-old females, pinpointing a potential infection route of oocytes. To identify potential immune regulators of ovarian endosymbionts, we have analyzed the transcriptomes of the ovarian bacteriomes through young adult development, from one-day-old adults to sexually mature ones. In contrast with midgut bacteriomes, immune effectors are downregulated in ovarian bacteriomes at the onset of sexual maturation. We hypothesize that relaxation of endosymbiont control by antimicrobial peptides might allow bacterial migration and potential oocyte infection, ensuring endosymbiont transmission.}, }
@article {pmid37035661, year = {2023}, author = {Michalik, A and Franco, DC and Deng, J and Szklarzewicz, T and Stroiński, A and Kobiałka, M and Łukasik, P}, title = {Variable organization of symbiont-containing tissue across planthoppers hosting different heritable endosymbionts.}, journal = {Frontiers in physiology}, volume = {14}, number = {}, pages = {1135346}, pmid = {37035661}, issn = {1664-042X}, abstract = {Sap-feeding hemipteran insects live in associations with diverse heritable symbiotic microorganisms (bacteria and fungi) that provide essential nutrients deficient in their hosts' diets. These symbionts typically reside in highly specialized organs called bacteriomes (with bacterial symbionts) or mycetomes (with fungal symbionts). The organization of these organs varies between insect clades that are ancestrally associated with different microbes. As these symbioses evolve and additional microorganisms complement or replace the ancient associates, the organization of the symbiont-containing tissue becomes even more variable. Planthoppers (Hemiptera: Fulgoromorpha) are ancestrally associated with bacterial symbionts Sulcia and Vidania, but in many of the planthopper lineages, these symbionts are now accompanied or have been replaced by other heritable bacteria (e.g., Sodalis, Arsenophonus, Purcelliella) or fungi. We know the identity of many of these microbes, but the symbiont distribution within the host tissues and the bacteriome organization have not been systematically studied using modern microscopy techniques. Here, we combine light, fluorescence, and transmission electron microscopy with phylogenomic data to compare symbiont tissue distributions and the bacteriome organization across planthoppers representing 15 families. We identify and describe seven primary types of symbiont localization and seven types of the organization of the bacteriome. We show that Sulcia and Vidania, when present, usually occupy distinct bacteriomes distributed within the body cavity. The more recently acquired gammaproteobacterial and fungal symbionts generally occupy separate groups of cells organized into distinct bacteriomes or mycetomes, distinct from those with Sulcia and Vidania. They can also be localized in the cytoplasm of fat body cells. Alphaproteobacterial symbionts colonize a wider range of host body habitats: Asaia-like symbionts often colonize the host gut lumen, whereas Wolbachia and Rickettsia are usually scattered across insect tissues and cell types, including cells containing other symbionts, bacteriome sheath, fat body cells, gut epithelium, as well as hemolymph. However, there are exceptions, including Gammaproteobacteria that share bacteriome with Vidania, or Alphaproteobacteria that colonize Sulcia cells. We discuss how planthopper symbiont localization correlates with their acquisition and replacement patterns and the symbionts' likely functions. We also discuss the evolutionary consequences, constraints, and significance of these findings.}, }
@article {pmid37035211, year = {2023}, author = {Gong, W and Zhang, S}, title = {YB1 participated in regulating mitochondrial activity through RNA replacement.}, journal = {Frontiers in oncology}, volume = {13}, number = {}, pages = {1145379}, pmid = {37035211}, issn = {2234-943X}, abstract = {As a relic of ancient bacterial endosymbionts, mitochondria play a central role in cell metabolism, apoptosis, autophagy, and other processes. However, the function of mitochondria-derived nucleic acids in cellular signal transduction has not been fully elucidated. Here, our work has found that Y-box binding protein 1 (YB1) maintained cellular autophagy at a moderate level to inhibit mitochondrial oxidative phosphorylation. In addition, mitochondrial RNA was leaked into cytosol under starvation, accompanied by YB1 mitochondrial relocation, resulting in YB1-bound RNA replacement. The mRNAs encoded by oxidative phosphorylation (OXPHOS)-associated genes and oncogene HMGA1 (high-mobility group AT-hook 1) were competitively replaced by mitochondria-derived tRNAs. The increase of free OXPHOS mRNAs released from the YB1 complex enhanced mitochondrial activity through facilitating translation, but the stability of HMGA1 mRNA was impaired without the protection of YB1, both contributing to breast cancer cell apoptosis and reactive oxygen species production. Our finding not only provided a new potential target for breast cancer therapy but also shed new light on understanding the global landscape of cellular interactions between RNA-binding proteins and different RNA species.}, }
@article {pmid37022136, year = {2023}, author = {Arras, SD and Sibaeva, N and Catchpole, RJ and Horinouchi, N and Si, D and Rickerby, AM and Deguchi, K and Hibi, M and Tanaka, K and Takeuchi, M and Ogawa, J and Poole, AM}, title = {Characterisation of an Escherichia coli line that completely lacks ribonucleotide reduction yields insights into the evolution of parasitism and endosymbiosis.}, journal = {eLife}, volume = {12}, number = {}, pages = {}, doi = {10.7554/eLife.83845}, pmid = {37022136}, issn = {2050-084X}, abstract = {All life requires ribonucleotide reduction for de novo synthesis of deoxyribonucleotides. A handful of obligate intracellular species are known to lack ribonucleotide reduction and are instead dependent on their host for deoxyribonucleotide synthesis. As ribonucleotide reduction has on occasion been lost in obligate intracellular parasites and endosymbionts, we reasoned that it should in principle be possible to knock this process out entirely under conditions where deoxyribonucleosides are present in the growth media. We report here the creation of a strain of E. coli where all three ribonucleotide reductase operons have been fully deleted following introduction of a broad spectrum deoxyribonucleoside kinase from Mycoplasma mycoides. Our strain is able to grow in the presence of deoxyribonucleosides and shows slowed but substantial growth. Under limiting deoxyribonucleoside levels, we observe a distinctive filamentous cell morphology, where cells grow but do not appear to divide regularly. Finally, we examined whether our lines are able to adapt to limited supplies of deoxyribonucleosides, as might occur in the evolutionary switch from de novo synthesis to dependence on host production during the evolution of parasitism or endosymbiosis. Over the course of an evolution experiment, we observe a 25-fold reduction in the minimum concentration of exogenous deoxyribonucleosides necessary for growth. Genome analysis of replicate lines reveals that several lines carry mutations in deoB and cdd. deoB codes for phosphopentomutase, a key part of the deoxyriboaldolase pathway, which has been hypothesised as an alternative to ribonucleotide reduction for deoxyribonucleotide synthesis. Rather than synthesis via this pathway complementing the loss of ribonucleotide reduction, our experiments reveal that mutations appear that reduce or eliminate the capacity for this pathway to catabolise deoxyribonucleotides, thus preventing their loss via central metabolism. Mutational inactivation of both deoB and cdd is also observed in a number of obligate intracellular bacteria that have lost ribonucleotide reduction. We conclude that our experiments recapitulate key evolutionary steps in the adaptation to intracellular life without ribonucleotide reduction.}, }
@article {pmid37021082, year = {2023}, author = {Rutagarama, VP and Ireri, PM and Sibomana, C and Omufwoko, KS and Martin, SH and Ffrench-Constant, RH and Eckardt, W and Kaplin, BK and Smith, DAS and Gordon, I}, title = {African Queens find mates when males are rare.}, journal = {Ecology and evolution}, volume = {13}, number = {4}, pages = {e9956}, pmid = {37021082}, issn = {2045-7758}, abstract = {In butterflies and moths, male-killing endosymbionts are transmitted from infected females via their eggs, and the male progeny then perish. This means that successful transmission of the parasite relies on the successful mating of the host. Paradoxically, at the population level, parasite transmission also reduces the number of adult males present in the final population for infected females to mate with. Here we investigate if successful female mating when males are rare is indeed a likely rate-limiting step in the transmission of male-killing Spiroplasma in the African Monarch, Danaus chrysippus. In Lepidoptera, successful pairings are hallmarked by the transfer of a sperm-containing spermatophore from the male to the female during copulation. Conveniently, this spermatophore remains detectable within the female upon dissection, and thus, spermatophore counts can be used to assess the frequency of successful mating in the field. We used such spermatophore counts to examine if altered sex ratios in the D. chrysippus do indeed affect female mating success. We examined two different field sites in East Africa where males were often rare. Surprisingly, mated females carried an average of 1.5 spermatophores each, regardless of male frequency, and importantly, only 10-20% remained unmated. This suggests that infected females will still be able to mate in the face of either Spiroplasma-mediated male killing and/or fluctuations in adult sex ratio over the wet-dry season cycle. These observations may begin to explain how the male-killing mollicute can still be successfully transmitted in a population where males are rare.}, }
@article {pmid37016457, year = {2023}, author = {Junghare, M and Manavalan, T and Fredriksen, L and Leiros, I and Altermark, B and Eijsink, VGH and Vaaje-Kolstad, G}, title = {Biochemical and structural characterisation of a family GH5 cellulase from endosymbiont of shipworm P. megotara.}, journal = {Biotechnology for biofuels and bioproducts}, volume = {16}, number = {1}, pages = {61}, pmid = {37016457}, issn = {2731-3654}, abstract = {BACKGROUND: Cellulases play a key role in the enzymatic conversion of plant cell-wall polysaccharides into simple and economically relevant sugars. Thus, the discovery of novel cellulases from exotic biological niches is of great interest as they may present properties that are valuable in the biorefining of lignocellulosic biomass.<br><br>RESULTS: We have characterized a glycoside hydrolase 5 (GH5) domain of a bi-catalytic GH5-GH6 multi-domain enzyme from the unusual gill endosymbiont Teredinibacter waterburyi of the wood-digesting shipworm Psiloteredo megotara. The catalytic&#xa0;GH5 domain, was cloned and recombinantly produced with or without a&#xa0;C-terminal&#xa0;family 10 carbohydrate-binding module (CBM). Both variants showed hydrolytic endo-activity on soluble substrates such as&#xa0;&#x3b2;-glucan, carboxymethylcellulose and konjac glucomannan, respectively. However, low activity was observed towards the crystalline form of cellulose. Interestingly, when co-incubated with a cellulose-active LPMO, a clear synergy was observed that boosted the overall hydrolysis of crystalline cellulose. The crystal structure of the GH5 catalytic domain was solved to 1.0&#xa0;&#xc5; resolution and revealed a substrate binding cleft&#xa0;extension containing a putative&#x2009;+&#x2009;3 subsite, which is uncommon in this enzyme family. The enzyme&#xa0;was active in a wide range of pH, temperatures and showed high tolerance for NaCl.<br><br>CONCLUSIONS: This study provides significant knowledge in the discovery of new enzymes from shipworm gill endosymbionts and sheds new light on biochemical and structural characterization of cellulolytic cellulase. Study demonstrated a boost in the hydrolytic activity of cellulase on crystalline cellulose when co-incubated with cellulose-active LPMO. These findings will be relevant for the development of future enzyme cocktails that may be useful for the biotechnological conversion of lignocellulose.}, }
@article {pmid37016078, year = {2023}, author = {Nielsen, DA and Petrou, K}, title = {Lipid stores reveal the state of the coral-algae symbiosis at the single-cell level.}, journal = {ISME communications}, volume = {3}, number = {1}, pages = {29}, pmid = {37016078}, issn = {2730-6151}, abstract = {Coral reefs worldwide are threatened by environmental stress. The observable decline in coral cover, is principally due to the intensifying breakdown of the coral symbiosis, a process known as 'bleaching'. Overproduction of reactive oxygen species (ROS) is considered a key driver of coral bleaching, where environmental stress leads to increased ROS expression. To explore the link between ROS damage and symbiont status, we measured lipid peroxidation (LPO), a ubiquitous form of ROS damage, in the lipid stores of individual endo- and ex-symbiotic algal cells of three coral species, using confocal microscopy and a lipid hydroperoxide sensitive fluorescent dye. We found LPO was higher in endosymbionts, while lipid volume was greater in ex-symbiotic cells. Cluster analysis revealed three metabolic profiles differentiating endosymbiotic (#1: high LPO, low lipid) and ex-symbiotic cells (#3: low LPO, high lipid), with the intermediate group (#2) containing both cell types. Heat stress caused endosymbionts of Pocillopora acuta to shift away from cluster #1, suggesting this cluster represents cells in healthy/stable symbiosis. Our study delivers a new means to assess the coral symbiosis, demonstrating that symbiont LPO ratio combined with lipid store volume is a robust metabolic marker for the state of the symbiosis at the cellular level.}, }
@article {pmid37005434, year = {2023}, author = {Argandona, JA and Kim, D and Hansen, AK}, title = {Comparative transcriptomics of aphid species that diverged &gt; 22 MYA reveals genes that are important for the maintenance of their symbiosis.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {5341}, pmid = {37005434}, issn = {2045-2322}, abstract = {Most plant-sap feeding insects have obligate relationships with maternally transmitted bacteria. Aphids require their nutritional endosymbiont, Buchnera aphidicola, for the production of essential amino acids. Such endosymbionts are harbored inside of specialized insect cells called bacteriocytes. Here, we use comparative transcriptomics of bacteriocytes between two recently diverged aphid species, Myzus persicae and Acyrthosiphon pisum, to identify key genes that are important for the maintenance of their nutritional mutualism. The majority of genes with conserved expression profiles in M. persicae and A. pisum are for orthologs previously identified in A. pisum to be important for the symbiosis. However, asparaginase which produces aspartate from asparagine was significantly up-regulated only in A. pisum bacteriocytes, potentially because Buchnera of M. persicae encodes its own asparaginase enzyme unlike Buchnera of A. pisum resulting in Buchnera of A. pisum to be dependent on its aphid host for aspartate. One-to-one orthologs that explained the most amount of variation for bacteriocyte specific mRNA expression for both species includes a collaborative gene for methionine biosynthesis, multiple transporters, a horizontally transmitted gene, and secreted proteins. Finally, we highlight species-specific gene clusters which may contribute to host adaptations and/or accommodations in gene regulation to changes in the symbiont or the symbiosis.}, }
@article {pmid37001324, year = {2023}, author = {Romano, DMM and Pereira, TN and Almeida, IB and Coelho, CSG and Duarte, FC and Harakava, R and Cassiano, LL and Mendes, MC}, title = {First molecular evidence of Wolbachia occurrence in Amblyomma sculptum (Acari: Ixodidae).}, journal = {Veterinary parasitology}, volume = {317}, number = {}, pages = {109907}, doi = {10.1016/j.vetpar.2023.109907}, pmid = {37001324}, issn = {1873-2550}, abstract = {As the main vector for the bacterium Rickettsia rickettsii in Brazil, the tick Amblyomma sculptum is a parasite of great public health importance in this country. Wolbachia is an endosymbiont bacterium highly widespread among invertebrates and because of its impact on its hosts' biology, form a powerful alternative for pests and disease control. The aim of this study was to investigate the occurrence of this bacterium in A. sculptum. For this, 187 adult ticks collected in two municipalities in the interior of the state of São Paulo, Brazil, were analyzed using molecular techniques and bioinformatics tools. A total of 15 ticks were positive for the presence of Wolbachia. Phylogenetic analysis on the 16S rRNA gene indicated that the Wolbachia DNA sequences obtained in this investigation belonged to different clades, probably in supergroups B and F. This was the first study to report the occurrence of Wolbachia in A. sculptum and it enriches knowledge about the susceptibility of ticks to this bacterium. Now that we know that Wolbachia can be found in A. sculptum, the objective for a next study must be to investigate Wolbachia's possible origin in this tick.}, }
@article {pmid37001140, year = {2023}, author = {Newman, LE and Shadel, GS}, title = {Mitochondrial DNA Release in Innate Immune Signaling.}, journal = {Annual review of biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1146/annurev-biochem-032620-104401}, pmid = {37001140}, issn = {1545-4509}, abstract = {According to the endosymbiotic theory, most of the DNA of the original bacterial endosymbiont has been lost or transferred to the nucleus, leaving a much smaller (∼16 kb in mammals), circular molecule that is the present-day mitochondrial DNA (mtDNA). The ability of mtDNA to escape mitochondria and integrate into the nuclear genome was discovered in budding yeast, along with genes that regulate this process. Mitochondria have emerged as key regulators of innate immunity, and it is now recognized that mtDNA released into the cytoplasm, outside of the cell, or into circulation activates multiple innate immune signaling pathways. Here, we first review the mechanisms through which mtDNA is released into the cytoplasm, including several inducible mitochondrial pores and defective mitophagy or autophagy. Next, we cover how the different forms of released mtDNA activate specific innate immune nucleic acid sensors and inflammasomes. Finally, we discuss how intracellular and extracellular mtDNA release, including circulating cell-free mtDNA that promotes systemic inflammation, are implicated in human diseases, bacterial and viral infections, and senescence and aging. Expected final online publication date for the Annual Review of Biochemistry, Volume 92 is June 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.}, }
@article {pmid36993585, year = {2023}, author = {Beckmann, J and Gillespie, J and Tauritz, D}, title = {Modelling Emergence of Wolbachia Toxin-Antidote Protein Functions with an Evolutionary Algorithm.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.23.533954}, pmid = {36993585}, abstract = {Evolutionary algorithms (EAs) simulate Darwinian evolution and adeptly mimic natural evolution. Most EA applications in biology encode high levels of abstraction in top-down ecological population models. In contrast, our research merges protein alignment algorithms from bioinformatics into codon based EAs that simulate molecular protein string evolution from the bottom up. We apply our EA to reconcile a problem in the field of Wolbachia induced cytoplasmic incompatibility (CI). Wolbachia is a microbial endosymbiont that lives inside insect cells. CI is conditional insect sterility that operates as a toxin antidote (TA) system. Although, CI exhibits complex phenotypes not fully explained under a single discrete model. We instantiate in-silico genes that control CI, CI factors (cifs), as strings within the EA chromosome. We monitor the evolution of their enzymatic activity, binding, and cellular localization by applying selective pressure on their primary amino acid strings. Our model helps rationalize why two distinct mechanisms of CI induction might coexist in nature. We find that nuclear localization signals (NLS) and Type IV secretion system signals (T4SS) are of low complexity and evolve fast, whereas binding interactions have intermediate complexity, and enzymatic activity is the most complex. Our model predicts that as ancestral TA systems evolve into eukaryotic CI systems, the placement of NLS or T4SS signals can stochastically vary, imparting effects that might impact CI induction mechanics. Our model highlights how preconditions, genetic diversity, and sequence length can bias evolution of cifs towards one mechanism or another.}, }
@article {pmid36989877, year = {2023}, author = {Weisse, T and Scheffel, U and Stadler, P}, title = {Temperature-dependent resistance to starvation of three contrasting freshwater ciliates.}, journal = {European journal of protistology}, volume = {88}, number = {}, pages = {125973}, doi = {10.1016/j.ejop.2023.125973}, pmid = {36989877}, issn = {1618-0429}, abstract = {We investigated the temperature-dependent response to starvation of three contrasting freshwater ciliates (Ciliophora). The cyst-forming algivorous species Meseres corlissi and the bactivorous species Glaucomides bromelicola, which cannot form cysts, co-occur in the reservoirs (tanks) of tree bromeliads. The mixotrophic species Coleps spetai is common in many lakes. We hypothesized that the ciliates' different traits and life strategies would affect their survival rates and temperature sensitivity under food depleted conditions. We measured the decline of the ciliate populations in microcosm experiments at different temperatures for several days. We used an imaging flow cytometer to size the ciliates and documented their morphological and physiological changes in response to starvation. We found that the cyst-forming species had the highest mortality rates but may endure long-term starvation by encystment. The sympatric, non-encysting species suffered the lowest mortality rates and could survive for more than three weeks without food. The mixotrophic species had intermediate mortality rates but showed the highest phenotypic plasticity in response to starvation. A significant fraction of the C. spetai population appeared unaffected by starvation, suggesting that the endosymbionts provided some resources to the host cells. The mean mortality rate per day of all three species increased with temperature by 0.09 °C[-1].}, }
@article {pmid36986288, year = {2023}, author = {Moore, C and Lashnits, E and Neupane, P and Herrin, BH and Lappin, M and André, MR and Breitschwerdt, EB}, title = {Feeding on a Bartonella henselae Infected Host Triggers Temporary Changes in the Ctenocephalides felis Microbiome.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/pathogens12030366}, pmid = {36986288}, issn = {2076-0817}, abstract = {The effect of Bartonella henselae on the microbiome of its vector, Ctenocephalides felis (the cat flea) is largely unknown, as the majority of C. felis microbiome studies have utilized wild-caught pooled fleas. We surveyed the microbiome of laboratory-origin C. felis fed on B. henselae-infected cats for 24 h or 9 days to identify changes to microbiome diversity and microbe prevalence compared to unfed fleas, and fleas fed on uninfected cats. Utilizing Next Generation Sequencing (NGS) on the Illumina platform, we documented an increase in microbial diversity in C. felis fed on Bartonella-infected cats for 24 h. These changes returned to baseline (unfed fleas or fleas fed on uninfected cats) after 9 days on the host. Increased diversity in the C. felis microbiome when fed on B. henselae-infected cats may be related to the mammalian, flea, or endosymbiont response. Poor B. henselae acquisition was documented with only one of four infected flea pools having B. henselae detected by NGS. We hypothesize this is due to the use of adult fleas, flea genetic variation, or lack of co-feeding with B. henselae-infected fleas. Future studies are necessary to fully characterize the effect of endosymbionts and C. felis diversity on B. henselae acquisition.}, }
@article {pmid36985289, year = {2023}, author = {Huynh, LN and Diarra, AZ and Pham, QL and Berenger, JM and Ho, VH and Nguyen, XQ and Parola, P}, title = {Identification of Vietnamese Flea Species and Their Associated Microorganisms Using Morphological, Molecular, and Protein Profiling.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030716}, pmid = {36985289}, issn = {2076-2607}, abstract = {Fleas are obligatory blood-sucking ectoparasites of medical and veterinary importance. The identification of fleas and associated flea-borne microorganisms, therefore, plays an important role in controlling and managing these vectors. Recently, Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been reported as an innovative and effective approach to the identification of arthropods, including fleas. This study aims to use this technology to identify ethanol-preserved fleas collected in Vietnam and to use molecular biology to search for microorganisms associated with these fleas. A total of 502 fleas were collected from wild and domestic animals in four provinces in Vietnam. Morphological identification led to the recognition of five flea species, namely Xenopsylla cheopis, Xenopsylla astia, Pulex irritans, Ctenocephalides canis, and Ctenocephalides felis. The cephalothoraxes of 300 individual, randomly selected fleas were tested using MALDI-TOF MS and molecular analysis for the identification and detection of microorganisms. A total of 257/300 (85.7%) of the obtained spectra from the cephalothoraxes of each species were of good enough quality to be used for our analyses. Our laboratory MALDI-TOF MS reference database was upgraded with spectra achieved from five randomly selected fleas for every species of Ctenocephalides canis and Ctenocephalides felis. The remaining spectra were then queried against the upgraded MALDI-TOF MS database, which showed 100% correspondence between morphology and MALDI-TOF MS identification for two flea species (Ctenocephalides canis and Ctenocephalides felis). The MS spectra of the remaining species (three P. irritans, five X. astia, and two X. cheopis) were visually generated low-intensity MS profiles with high background noise that could not be used to update our database. Bartonella and Wolbachia spp. were detected in 300 fleas from Vietnam using PCR and sequencing with primers derived from the gltA gene for Bartonella and the 16S rRNA gene for Wolbachia, including 3 Bartonella clarridgeiae (1%), 3 Bartonella rochalimae (1%), 1 Bartonella coopersplainsensis (0.3%), and 174 Wolbachia spp. endosymbionts (58%).}, }
@article {pmid36985288, year = {2023}, author = {Cossu, CA and Collins, NE and Oosthuizen, MC and Menandro, ML and Bhoora, RV and Vorster, I and Cassini, R and Stoltsz, H and Quan, M and van Heerden, H}, title = {Distribution and Prevalence of Anaplasmataceae, Rickettsiaceae and Coxiellaceae in African Ticks: A Systematic Review and Meta-Analysis.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030714}, pmid = {36985288}, issn = {2076-2607}, abstract = {In Africa, ticks continue to be a major hindrance to the improvement of the livestock industry due to tick-borne pathogens that include Anaplasma, Ehrlichia, Rickettsia and Coxiella species. A systemic review and meta-analysis were conducted here and highlighted the distribution and prevalence of these tick-borne pathogens in African ticks. Relevant publications were searched in five electronic databases and selected using inclusion/exclusion criteria, resulting in 138 and 78 papers included in the qualitative and quantitative analysis, respectively. Most of the studies focused on Rickettsia africae (38 studies), followed by Ehrlichia ruminantium (27 studies), Coxiella burnetii (20 studies) and Anaplasma marginale (17 studies). A meta-analysis of proportions was performed using the random-effects model. The highest prevalence was obtained for Rickettsia spp. (18.39%; 95% CI: 14.23-22.85%), R. africae (13.47%; 95% CI: 2.76-28.69%), R. conorii (11.28%; 95% CI: 1.77-25.89%), A. marginale (12.75%; 95% CI: 4.06-24.35%), E. ruminantium (6.37%; 95% CI: 3.97-9.16%) and E. canis (4.3%; 95% CI: 0.04-12.66%). The prevalence of C. burnetii was low (0%; 95% CI: 0-0.25%), with higher prevalence for Coxiella spp. (27.02%; 95% CI: 10.83-46.03%) and Coxiella-like endosymbionts (70.47%; 95% CI: 27-99.82%). The effect of the tick genera, tick species, country and other variables were identified and highlighted the epidemiology of Rhipicephalus ticks in the heartwater; affinity of each Rickettsia species for different tick genera; dominant distribution of A. marginale, R. africae and Coxiella-like endosymbionts in ticks and a low distribution of C. burnetii in African hard ticks.}, }
@article {pmid36985217, year = {2023}, author = {Djondji Kamga, FM and Mugenzi, LMJ and Tchouakui, M and Sandeu, MM and Maffo, CGT and Nyegue, MA and Wondji, CS}, title = {Contrasting Patterns of Asaia Association with Pyrethroid Resistance Escalation between the Malaria Vectors Anopheles funestus and Anopheles gambiae.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030644}, pmid = {36985217}, issn = {2076-2607}, abstract = {Microbiome composition has been associated with insecticide resistance in malaria vectors. However, the contribution of major symbionts to the increasingly reported resistance escalation remains unclear. This study explores the possible association of a specific endosymbiont, Asaia spp., with elevated levels of pyrethroid resistance driven by cytochrome P450s enzymes and voltage-gated sodium channel mutations in Anopheles funestus and Anopheles gambiae. Molecular assays were used to detect the symbiont and resistance markers (CYP6P9a/b, 6.5 kb, L1014F, and N1575Y). Overall, genotyping of key mutations revealed an association with the resistance phenotype. The prevalence of Asaia spp. in the FUMOZ_X_FANG strain was associated with the resistance phenotype at a 5X dose of deltamethrin (OR = 25.7; p = 0.002). Mosquitoes with the resistant allele for the markers tested were significantly more infected with Asaia compared to those possessing the susceptible allele. Furthermore, the abundance correlated with the resistance phenotype at 1X concentration of deltamethrin (p = 0.02, Mann-Whitney test). However, for the MANGOUM_X_KISUMU strain, findings rather revealed an association between Asaia load and the susceptible phenotype (p = 0.04, Mann-Whitney test), demonstrating a negative link between the symbiont and permethrin resistance. These bacteria should be further investigated to establish its interactions with other resistance mechanisms and cross-resistance with other insecticide classes.}, }
@article {pmid36982826, year = {2023}, author = {Stączek, S and Cytryńska, M and Zdybicka-Barabas, A}, title = {Unraveling the Role of Antimicrobial Peptides in Insects.}, journal = {International journal of molecular sciences}, volume = {24}, number = {6}, pages = {}, doi = {10.3390/ijms24065753}, pmid = {36982826}, issn = {1422-0067}, abstract = {Antimicrobial peptides (AMPs) are short, mainly positively charged, amphipathic molecules. AMPs are important effectors of the immune response in insects with a broad spectrum of antibacterial, antifungal, and antiparasitic activity. In addition to these well-known roles, AMPs exhibit many other, often unobvious, functions in the host. They support insects in the elimination of viral infections. AMPs participate in the regulation of brain-controlled processes, e.g., sleep and non-associative learning. By influencing neuronal health, communication, and activity, they can affect the functioning of the insect nervous system. Expansion of the AMP repertoire and loss of their specificity is connected with the aging process and lifespan of insects. Moreover, AMPs take part in maintaining gut homeostasis, regulating the number of endosymbionts as well as reducing the number of foreign microbiota. In turn, the presence of AMPs in insect venom prevents the spread of infection in social insects, where the prey may be a source of pathogens.}, }
@article {pmid36975937, year = {2023}, author = {Li, H and Jiang, Z and Zhou, J and Liu, X and Zhang, Y and Chu, D}, title = {Ecological Factors Associated with the Distribution of Bemisia tabaci Cryptic Species and Their Facultative Endosymbionts.}, journal = {Insects}, volume = {14}, number = {3}, pages = {}, doi = {10.3390/insects14030252}, pmid = {36975937}, issn = {2075-4450}, abstract = {The sweetpotato whitefly, Bemisia tabaci species complex, comprises at least 44 morphologically indistinguishable cryptic species, whose endosymbiont infection patterns often varied at the spatial and temporal dimension. However, the effects of ecological factors (e.g., climatic or geographical factors) on the distribution of whitefly and the infection frequencies of their endosymbionts have not been fully elucidated. We, here, analyzed the associations between ecological factors and the distribution of whitefly and their three facultative endosymbionts (Candidatus Cardinium hertigii, Candidatus Hamiltonella defensa, and Rickettsia sp.) by screening 665 individuals collected from 29 geographical localities across China. The study identified eight B. tabaci species via mitochondrial cytochrome oxidase I (mtCOI) gene sequence alignment: two invasive species, MED (66.9%) and MEAM1 (12.2%), and six native cryptic species (20.9%), which differed in distribution patterns, ecological niches, and high suitability areas. The infection frequencies of the three endosymbionts in different cryptic species were distinct and multiple infections were relatively common in B. tabaci MED populations. Furthermore, the annual mean temperature positively affected Cardinium sp. and Rickettsia sp. infection frequencies in B. tabaci MED but negatively affected the quantitative distribution of B. tabaci MED, which indicates that Cardinium sp. and Rickettsia sp. maybe play a crucial role in the thermotolerance of B. tabaci MED, although the host whitefly per se exhibits no resistance to high temperature. Our findings revealed the complex effects of ecological factors on the expansion of the invasive whitefly.}, }
@article {pmid36965057, year = {2023}, author = {Speijer, D}, title = {How mitochondria showcase evolutionary mechanisms and the importance of oxygen.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {}, number = {}, pages = {e2300013}, doi = {10.1002/bies.202300013}, pmid = {36965057}, issn = {1521-1878}, abstract = {Darwinian evolution can be simply stated: natural selection of inherited variations increasing differential reproduction. However, formulated thus, links with biochemistry, cell biology, ecology, and population dynamics remain unclear. To understand interactive contributions of chance and selection, higher levels of biological organization (e.g., endosymbiosis), complexities of competing selection forces, and emerging biological novelties (such as eukaryotes or meiotic sex), we must analyze actual examples. Focusing on mitochondria, I will illuminate how biology makes sense of life's evolution, and the concepts involved. First, looking at the bacterium - mitochondrion transition: merging with an archaeon, it lost its independence, but played a decisive role in eukaryogenesis, as an extremely efficient aerobic ATP generator and internal ROS source. Second, surveying later mitochondrion adaptations and diversifications illustrates concepts such as constructive neutral evolution, dynamic interactions between endosymbionts and hosts, the contingency of life histories, and metabolic reprogramming. Without oxygen, mitochondria disappear; with (intermittent) oxygen diversification occurs in highly complex ways, especially upon (temporary) phototrophic substrate supply. These expositions show the Darwinian model to be a highly fruitful paradigm.}, }
@article {pmid36958587, year = {2023}, author = {Verhulst, EC and Pannebakker, BA and Geuverink, E}, title = {Variation in sex determination mechanisms may constrain parthenogenesis-induction by endosymbionts in haplodiploid systems.}, journal = {Current opinion in insect science}, volume = {}, number = {}, pages = {101023}, doi = {10.1016/j.cois.2023.101023}, pmid = {36958587}, issn = {2214-5753}, abstract = {Endosymbionts are maternally transmitted, and therefore benefit from maximizing female offspring numbers. Parthenogenesis-induction (PI) is the most effective type of manipulation for transmission, but has solely been detected in haplodiploid species, whereas cytoplasmic incompatibility (CI) is detected frequently across the arthropod phylum, including haplodiploids. This puzzling observation led us to hypothesize that the molecular sex-determination mechanism of the haplodiploid host may be a constraining factor in the ability of endosymbionts to induce parthenogenesis. Recent insights indicate that PI-endosymbionts may be able to directly manipulate sex-determination genes to induce the necessary steps required for PI in haplodiploids. However, sex-determination cascades vary extensively, so PI-induction would require a specialized and host-dependent tool set. Contrastingly, CI-related genes target conserved cell-cycle mechanisms, are located on mobile elements, and spread easily. Finally, endosymbiont-manipulations may have a strong impact on the effectiveness of haplodiploid biocontrol agents, but can also be used to enhance their efficacy.}, }
@article {pmid36950155, year = {2023}, author = {Moore, C and Breitschwerdt, EB and Kim, L and Li, Y and Ferris, K and Maggi, R and Lashnits, E}, title = {The association of host and vector characteristics with Ctenocephalides felis pathogen and endosymbiont infection.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1137059}, pmid = {36950155}, issn = {1664-302X}, abstract = {Surveillance of the fleas and flea-borne pathogens infecting cats is important for both human and animal health. Multiple zoonotic Bartonella and Rickettsia species are known to infect the most common flea infesting cats and dogs worldwide: Ctenocephalides felis, the cat flea. The ability of other flea species to transmit pathogens is relatively unexplored. We aimed to determine cat host and flea factors independently associated with flea Bartonella and Rickettsia infection. We also assessed flea and cat infection by flea-host pair and location. To accomplish these aims, we performed qPCR for the detection of Bartonella, hemotropic Mycoplasma, Rickettsia, and Wolbachia DNA using paired cat and flea samples obtained from free-roaming cats presenting for spay or neuter across four locations in the United States. A logistic regression model was employed to identify the effect of cat (sex, body weight, geographic location, and Bartonella, hemotropic Mycoplasma, and Rickettsia spp., infection) and flea (clade and Rickettsia and Wolbachia infection) factors on C. felis Bartonella clarridgeiae infection. From 189 free roaming cats, we collected 84 fleas: Ctenocephalides felis (78/84), Cediopsylla simplex (4/84), Orchopeas howardi (1/84), and Nosopsyllus fasciatus (1/84). Ctenocephalides felis were phylogenetically assigned to Clades 1, 4, and 6 by cox1 gene amplification. Rickettsia asembonensis (52/84) and B. clarridgeiae (16/84) were the most common pathogenic bacteria detected in fleas. Our model identified host cat sex and weight as independently associated with B. clarridgeiae infection in fleas. Rickettsia asembonensis (52/84), Rickettsia felis (7/84) and Bartonella henselae (7/84) were detected in specific clades: R. felis was detected only in Clades 1 and 6 while B. henselae and R. asembonensis were detected only in Clade 4. Wolbachia spp., also displayed clade specificity with strains other than Wolbachia wCfeT only infecting fleas from Clade 6. There was poor flea and host agreement for Bartonella spp., infection; however, there was agreement in the Bartonella species detected in cats and fleas by geographic location. These findings reinforce the importance of considering reservoir host attributes and vector phylogenetic diversity in epidemiological studies of flea-borne pathogens. Widespread sampling is necessary to identify the factors driving flea-borne pathogen presence and transmission.}, }
@article {pmid36949814, year = {2023}, author = {Ou, D and Qiu, JH and Su, ZQ and Wang, L and Qiu, BL}, title = {The phylogeny and distribution of Wolbachia in two pathogen vector insects, Asian citrus psyllid and Longan psyllid.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1121186}, pmid = {36949814}, issn = {2235-2988}, abstract = {BACKGROUND: Wolbachia is the most abundant bacterial endosymbiont among insects. It can play a prominent role in the development, reproduction and immunity of its given insect host. To date, Wolbachia presence is well studied within aphids, whiteflies and planthoppers, but relatively few studies have investigated its presence in psyllids.<br><br>METHODS: Here, the infection status of Wolbachia in five species of psyllid, including Asian citrus psyllid Diaphorina citri and longan psyllid Cornegenapsylla sinica was investigated. The phylogenetic relationships of different Wolbachia lines and their infection density and patterns in D. citri and C. sinica from different countries was also examined.<br><br>RESULTS: The infection rates of Wolbachia in D. citri and C. sinica were both 100%, and their sequencing types are ST173 and ST532 respectively. Phylogenetic analysis revealed that the Wolbachia lines in D. citri and C. sinica both belong to the Con subgroup of Wolbachia supergroup B. In addition, Wolbachia displayed a scattered localization pattern in the 5th instar nymphs and in the reproductive organs of both D. citri and C. sinica but differed in other tissues; it was highest in the midgut, lowest in the salivary glands and medium in both the testes and ovaries.<br><br>CONCLUSION: Our findings assist in further understanding the coevolution of Wolbachia and its psyllid hosts. Given that Wolbachia could play an important role in insect pest control and pathogen transmission inhibition, our findings may also provide new insights for development of control strategies for D. citri and C. sinica.}, }
@article {pmid36947547, year = {2023}, author = {Richardson, KM and Ross, PA and Cooper, BS and Conner, WR and Schmidt, T and Hoffmann, AA}, title = {A male-killing Wolbachia endosymbiont is concealed by another endosymbiont and a nuclear suppressor.}, journal = {PLoS biology}, volume = {21}, number = {3}, pages = {e3001879}, doi = {10.1371/journal.pbio.3001879}, pmid = {36947547}, issn = {1545-7885}, abstract = {Bacteria that live inside the cells of insect hosts (endosymbionts) can alter the reproduction of their hosts, including the killing of male offspring (male killing, MK). MK has only been described in a few insects, but this may reflect challenges in detecting MK rather than its rarity. Here, we identify MK Wolbachia at a low frequency (around 4%) in natural populations of Drosophila pseudotakahashii. MK Wolbachia had a stable density and maternal transmission during laboratory culture, but the MK phenotype which manifested mainly at the larval stage was lost rapidly. MK Wolbachia occurred alongside a second Wolbachia strain expressing a different reproductive manipulation, cytoplasmic incompatibility (CI). A genomic analysis highlighted Wolbachia regions diverged between the 2 strains involving 17 genes, and homologs of the wmk and cif genes implicated in MK and CI were identified in the Wolbachia assembly. Doubly infected males induced CI with uninfected females but not females singly infected with CI-causing Wolbachia. A rapidly spreading dominant nuclear suppressor genetic element affecting MK was identified through backcrossing and subsequent analysis with ddRAD SNPs of the D. pseudotakahashii genome. These findings highlight the complexity of nuclear and microbial components affecting MK endosymbiont detection and dynamics in populations and the challenges of making connections between endosymbionts and the host phenotypes affected by them.}, }
@article {pmid36939357, year = {2023}, author = {Macher, JN and Coots, NL and Poh, YP and Girard, EB and Langerak, A and Muñoz-Gómez, SA and Sinha, SD and Jirsová, D and Vos, R and Wissels, R and Gile, GH and Renema, W and Wideman, JG}, title = {Single-Cell Genomics Reveals the Divergent Mitochondrial Genomes of Retaria (Foraminifera and Radiolaria).}, journal = {mBio}, volume = {}, number = {}, pages = {e0030223}, doi = {10.1128/mbio.00302-23}, pmid = {36939357}, issn = {2150-7511}, abstract = {Mitochondria originated from an ancient bacterial endosymbiont that underwent reductive evolution by gene loss and endosymbiont gene transfer to the nuclear genome. The diversity of mitochondrial genomes published to date has revealed that gene loss and transfer processes are ongoing in many lineages. Most well-studied eukaryotic lineages are represented in mitochondrial genome databases, except for the superphylum Retaria-the lineage comprising Foraminifera and Radiolaria. Using single-cell approaches, we determined two complete mitochondrial genomes of Foraminifera and two nearly complete mitochondrial genomes of radiolarians. We report the complete coding content of an additional 14 foram species. We show that foraminiferan and radiolarian mitochondrial genomes contain a nearly fully overlapping but reduced mitochondrial gene complement compared to other sequenced rhizarians. In contrast to animals and fungi, many protists encode a diverse set of proteins on their mitochondrial genomes, including several ribosomal genes; however, some aerobic eukaryotic lineages (euglenids, myzozoans, and chlamydomonas-like algae) have reduced mitochondrial gene content and lack all ribosomal genes. Similar to these reduced outliers, we show that retarian mitochondrial genomes lack ribosomal protein and tRNA genes, contain truncated and divergent small and large rRNA genes, and contain only 14 or 15 protein-coding genes, including nad1, -3, -4, -4L, -5, and -7, cob, cox1, -2, and -3, and atp1, -6, and -9, with forams and radiolarians additionally carrying nad2 and nad6, respectively. In radiolarian mitogenomes, a noncanonical genetic code was identified in which all three stop codons encode amino acids. Collectively, these results add to our understanding of mitochondrial genome evolution and fill in one of the last major gaps in mitochondrial sequence databases. IMPORTANCE We present the reduced mitochondrial genomes of Retaria, the rhizarian lineage comprising the phyla Foraminifera and Radiolaria. By applying single-cell genomic approaches, we found that foraminiferan and radiolarian mitochondrial genomes contain an overlapping but reduced mitochondrial gene complement compared to other sequenced rhizarians. An alternative genetic code was identified in radiolarian mitogenomes in which all three stop codons encode amino acids. Collectively, these results shed light on the divergent nature of the mitochondrial genomes from an ecologically important group, warranting further questions into the biological underpinnings of gene content variability and genetic code variation between mitochondrial genomes.}, }
@article {pmid36939349, year = {2023}, author = {Xiong, Q and Fung, CS and Xiao, X and Wan, AT and Wang, M and Klimov, P and Ren, Y and Yang, KY and Hubert, J and Cui, Y and Liu, X and Tsui, SK}, title = {Endogenous Plasmids and Chromosomal Genome Reduction in the Cardinium Endosymbiont of Dermatophagoides farinae.}, journal = {mSphere}, volume = {}, number = {}, pages = {e0007423}, doi = {10.1128/msphere.00074-23}, pmid = {36939349}, issn = {2379-5042}, abstract = {Cardinium bacteria are well known as endosymbionts that infect a wide range of arthropods and can manipulate host reproduction to promote their vertical transmission. As intracellular bacteria, Cardinium species undergo dramatic genome evolution, especially their chromosomal genome reduction. Although Cardinium plasmids have been reported to harbor important genes, the role of these plasmids in the genome evolution is yet to be fully understood. In this study, 2 genomes of Cardinium endosymbiont bacteria in astigmatic mites were de novo assembled, including the complete circular chromosomal genome of Cardinium sp. DF that was constructed in high quality using high-coverage long-read sequencing data. Intriguingly, 2 circular plasmids were assembled in Cardinium sp. DF and were identified to be endogenous for over 10 homologous genes shared with the chromosomal genome. Comparative genomics analysis illustrated an outline of the genome evolution of Cardinium bacteria, and the in-depth analysis of Cardinium sp. DF shed light on the multiple roles of endogenous plasmids in the molecular process of the chromosomal genome reduction. The endogenous plasmids of Cardinium sp. DF not only harbor massive homologous sequences that enable homologous recombination with the chromosome, but also can provide necessary functional proteins when the coding genes decayed in the chromosomal genome. IMPORTANCE As bacterial endosymbionts, Cardinium typically undergoes genome reduction, but the molecular process is still unclear, such as how plasmids get involved in chromosome reduction. Here, we de novo assembled 2 genomes of Cardinium in astigmatic mites, especially the chromosome of Cardinium sp. DF was assembled in a complete circular DNA using high-coverage long-read sequencing data. In the genome assembly of Cardinium sp. DF, 2 circular endogenous plasmids were identified to share at least 10 homologous genes with the chromosomal genome. In the comparative analysis, we identified a range of genes decayed in the chromosomal genome of Cardinium sp. DF but preserved in the 2 plasmids. Taken together with in-depth analyses, our results unveil that the endogenous plasmids harbor homologous sequences of chromosomal genome and can provide a structural basis of homologous recombination. Overall, this study reveals that endogenous plasmids participate in the ongoing chromosomal genome reduction of Cardinium sp. DF.}, }
@article {pmid36934294, year = {2023}, author = {Allman, MJ and Lin, YH and Joubert, DA and Addley-Cook, J and Mejía-Torres, MC and Simmons, CP and Flores, HA and Fraser, JE}, title = {Enhancing the scalability of Wolbachia-based vector-borne disease management: time and temperature limits for storage and transport of Wolbachia-infected Aedes aegypti eggs for field releases.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {108}, pmid = {36934294}, issn = {1756-3305}, abstract = {BACKGROUND: Introgression of the bacterial endosymbiont Wolbachia into Aedes aegypti populations is a biocontrol approach being used to reduce arbovirus transmission. This requires mass release of Wolbachia-infected mosquitoes. While releases have been conducted using a variety of techniques, egg releases, using water-soluble capsules containing mosquito eggs and larval food, offer an attractive method due to its potential to reduce onsite resource requirements. However, optimisation of this approach is required to ensure there is no detrimental impact on mosquito fitness and to promote successful Wolbachia introgression.<br><br>METHODS: We determined the impact of storage time and temperature on wild-type (WT) and Wolbachia-infected (wMel or wAlbB strains) Ae. aegypti eggs. Eggs were stored inside capsules over 8 weeks at 18&#xa0;&#xb0;C or 22&#xa0;&#xb0;C and hatch rate, emergence rate and Wolbachia density were determined. We next examined egg quality and Wolbachia density after exposing eggs to 4-40&#xa0;&#xb0;C to determine how eggs may be impacted if exposed to extreme temperatures during shipment.<br><br>RESULTS: Encapsulating eggs for 8 weeks did not negatively impact egg viability or resulting adult emergence and Wolbachia density compared to controls. When eggs were exposed to temperatures within 4-36&#xa0;&#xb0;C for 48&#xa0;h, their viability and resulting adult Wolbachia density were maintained; however, both were significantly reduced when exposed to 40&#xa0;&#xb0;C.<br><br>CONCLUSIONS: We describe the time and temperature limits for maintaining viability of Wolbachia-infected Ae. aegypti eggs when encapsulated or exposed to extreme temperatures. These findings could improve the efficiency of mass releases by providing transport and storage constraints to ensure only high-quality material is utilised during field releases.}, }
@article {pmid36929176, year = {2023}, author = {Eugénio, AT and Marialva, MSP and Beldade, P}, title = {Effects of Wolbachia on transposable element expression vary between Drosophila melanogaster host genotypes.}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evad036}, pmid = {36929176}, issn = {1759-6653}, abstract = {Transposable elements (TEs) are repetitive DNA sequences capable of changing position in host genomes, thereby causing mutations. TE insertions typically have deleterious effects but they can also be beneficial. Increasing evidence of the contribution of TEs to adaptive evolution further raises interest in understanding what factors impact TE activity. Based on previous studies associating the bacterial endosymbiont Wolbachia to changes in the abundance of piRNAs, a mechanism for TE repression, and to transposition of specific TEs, we hypothesized that Wolbachia infection would interfere with TE activity. We tested this hypothesis by studying expression of 14 TEs in a panel of 25 Drosophila melanogaster host genotypes, naturally infected with Wolbachia and annotated for TE insertions. The host genotypes differed significantly in Wolbachia titers inside individual flies, with broad-sense heritability around 20%, and in the number of TE insertions, which depended greatly on TE identity. By removing Wolbachia from the target host genotypes, we generated a panel of 25 pairs of Wolbachia-positive and Wolbachia-negative lines in which we quantified transcription levels our target TEs. We found variation in TE expression that was dependent on Wolbachia status, TE identity, and host genotype. Comparing between pairs of Wolbachia-positive and Wolbachia-negative flies, we found that Wolbachia removal affected TE expression in 21.1% of the TE-genotype combinations tested, with up to 2.3 times differences in median level of transcript. Our data shows that Wolbachia can impact TE activity in host genomes, underscoring the importance this endosymbiont can have in the generation of genetic novelty in hosts.}, }
@article {pmid36928089, year = {2023}, author = {Terretaz, K and Horard, B and Weill, M and Loppin, B and Landmann, F}, title = {Functional analysis of Wolbachia Cid effectors unravels cooperative interactions to target host chromatin during replication.}, journal = {PLoS pathogens}, volume = {19}, number = {3}, pages = {e1011211}, doi = {10.1371/journal.ppat.1011211}, pmid = {36928089}, issn = {1553-7374}, abstract = {Wolbachia are common bacteria among terrestrial arthropods. These endosymbionts transmitted through the female germline manipulate their host reproduction through several mechanisms whose most prevalent form called Cytoplasmic Incompatibility -CI- is a conditional sterility syndrome eventually favoring the infected progeny. Upon fertilization, the sperm derived from an infected male is only compatible with an egg harboring a compatible Wolbachia strain, this sperm leading otherwise to embryonic death. The Wolbachia Cif factors CidA and CidB responsible for CI and its neutralization function as a Toxin-Antitoxin system in the mosquito host Culex pipiens. However, the mechanism of CidB toxicity and its neutralization by the CidA antitoxin remain unexplored. Using transfected insect cell lines to perform a structure-function analysis of these effectors, we show that both CidA and CidB are chromatin interactors and CidA anchors CidB to the chromatin in a cell-cycle dependent-manner. In absence of CidA, the CidB toxin localizes to its own chromatin microenvironment and acts by preventing S-phase completion, independently of its deubiquitylase -DUB- domain. Experiments with transgenic Drosophila show that CidB DUB domain is required together with CidA during spermatogenesis to stabilize the CidA-CidB complex. Our study defines CidB functional regions and paves the way to elucidate the mechanism of its toxicity.}, }
@article {pmid36911919, year = {2023}, author = {Radousky, YA and Hague, MTJ and Fowler, S and Paneru, E and Codina, A and Rugamas, C and Hartzog, G and Cooper, BS and Sullivan, W}, title = {Distinct Wolbachia localization patterns in oocytes of diverse host species reveal multiple strategies of maternal transmission.}, journal = {Genetics}, volume = {}, number = {}, pages = {}, doi = {10.1093/genetics/iyad038}, pmid = {36911919}, issn = {1943-2631}, abstract = {A broad array of endosymbionts radiate through host populations via vertical transmission, yet much remains unknown concerning the cellular basis, diversity and routes underlying this transmission strategy. Here we address these issues, by examining the cellular distributions of Wolbachia strains that diverged up to 50 million years ago in the oocytes of 18 divergent Drosophila species. This analysis revealed three Wolbachia distribution patterns: 1) a tight clustering at the posterior pole plasm (the site of germline formation); 2) a concentration at the posterior pole plasm, but with a significant bacteria population distributed throughout the oocyte; 3) and a distribution throughout the oocyte, with none or very few located at the posterior pole plasm. Examination of this latter class indicates Wolbachia accesses the posterior pole plasm during the interval between late oogenesis and the blastoderm formation. We also find that one Wolbachia strain in this class concentrates in the posterior somatic follicle cells that encompass the pole plasm of the developing oocyte. In contrast, strains in which Wolbachia concentrate at the posterior pole plasm generally exhibit no or few Wolbachia in the follicle cells associated with the pole plasm. Taken together, these studies suggest that for some Drosophila species, Wolbachia invade the germline from neighboring somatic follicle cells. Phylogenomic analysis indicates that closely related Wolbachia strains tend to exhibit similar patterns of posterior localization, suggesting that specific localization strategies are a function of Wolbachia-associated factors. Previous studies revealed that endosymbionts rely on one of two distinct routes of vertical transmission: continuous maintenance in the germline (germline-to-germline) or a more circuitous route via the soma (germline-to-soma-to-germline). Here we provide compelling evidence that Wolbachia strains infecting Drosophila species maintain the diverse arrays of cellular mechanisms necessary for both of these distinct transmission routes. This characteristic may account for its ability to infect and spread globally through a vast range of host insect species.}, }
@article {pmid36909700, year = {2022}, author = {Murugesan, RK and Balakrishnan, R and Natesan, S and Jayavel, S and Muthiah, RC}, title = {Identification of coral endosymbionts of Veedhalai and Mandapam coasts of Palk Bay, India using small subunit rDNA.}, journal = {Bioinformation}, volume = {18}, number = {4}, pages = {318-324}, pmid = {36909700}, issn = {0973-2063}, abstract = {Coral endosymbionts act as a bio-indicator of coral ecosystem under extreme environmental conditions. The health of the coral ecosystem depends on the endosymbiont cell density of the coral hosts. Therefore, it is of interest to analyze ten coral fragments found to be under the genera Acropora, Favites, Favia, and Porites collected at various locations from Veedhalai to Mandapam, southeast coast of India during January 2019 to March 2019. The zooxanthellae cell count ranged between 4.08 (Porites sp.9) and 13.75x105 cells cm2 -1 (Favites sp.3). This indicates the health of the corals in the region. The genus (clade) level identification of endosymbionts was detected using the host excluding primers of small subunit DNA (nssrDNA). Bidirectional sequencing of 18S nrDNA gene (SSU) of all ten coral fragments show that the Veedhalai corals is associated with the genus Durusdinium (Clade D) but the corals of Mandapam is associated with the genera, Cladocopium (Clade C) and Durusdinium (Clade D). It is known that the thermal stress has negative impact on coral reef ecosystem of the world. The dominance of the genus Durusdinium in the scleractinian corals of Palk Bay may be due to frequent exposure to thermal stress. This thermotolerant endosymbionts is opportunistic. Thus, the corals of Veedhalai and Mandapam coasts, Palk Bay, India are necessarily packed with thermotolerant endosymbionts enabling conservation.}, }
@article {pmid36909625, year = {2023}, author = {Verhoeve, VI and Lehman, SS and Driscoll, TP and Beckmann, JF and Gillespie, JJ}, title = {Metagenome diversity illuminates origins of pathogen effectors.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.02.26.530123}, pmid = {36909625}, abstract = {Recent metagenome assembled genome (MAG) analyses have profoundly impacted Rickettsiology systematics. Discovery of basal lineages (Mitibacteraceae and Athabascaceae) with predicted extracellular lifestyles reveals an evolutionary timepoint for the transition to host dependency, which occurred independent of mitochondrial evolution. Notably, these basal rickettsiae carry the Rickettsiales vir homolog (rvh) type IV secretion system (T4SS) and purportedly use rvh to kill congener microbes rather than parasitize host cells as described for derived rickettsial pathogens. MAG analysis also substantially increased diversity for genus Rickettsia and delineated a basal lineage (Tisiphia) that stands to inform on the rise of human pathogens from protist and invertebrate endosymbionts. Herein, we probed Rickettsiales MAG and genomic diversity for the distribution of Rickettsia rvh effectors to ascertain their origins. A sparse distribution of most Rickettsia rvh effectors outside of Rickettsiaceae lineages indicates unique rvh evolution from basal extracellular species and other rickettsial families. Remarkably, nearly every effector was found in multiple divergent forms with variable architectures, illuminating profound roles for gene duplication and recombination in shaping effector repertoires in Rickettsia pathogens. Lateral gene transfer plays a prominent role shaping the rvh effector landscape, as evinced by the discover of many effectors on plasmids and conjugative transposons, as well as pervasive effector gene exchange between Rickettsia and Legionella species. Our study exemplifies how MAGs can provide incredible insight on the origins of pathogen effectors and how their architectural modifications become tailored to eukaryotic host cell biology.}, }
@article {pmid36907292, year = {2023}, author = {Ruiz, A and Gutiérrez-Bugallo, G and Rodríguez-Roche, R and Pérez, L and González-Broche, R and Piedra, LA and Martínez, LC and Menéndez, Z and Vega-Rúa, A and Bisset, JA}, title = {First report of natural Wolbachia infections in mosquitoes from Cuba.}, journal = {Acta tropica}, volume = {}, number = {}, pages = {106891}, doi = {10.1016/j.actatropica.2023.106891}, pmid = {36907292}, issn = {1873-6254}, abstract = {Mosquitoes are extensively responsible for the transmission of pathogens. Novel strategies using Wolbachia could transform that scenario, since these bacteria manipulate mosquito reproduction, and can confer a pathogen transmission-blocking phenotype in culicids. Here, we screened the Wolbachia surface protein region by PCR in eight Cuban mosquito species. We confirmed the natural infections by sequencing and assessed the phylogenetic relationships among the Wolbachia strains detected. We identified four Wolbachia hosts: Aedes albopictus, Culex quinquefasciatus, Mansonia titillans, and Aedes mediovittatus (first report worldwide). Knowledge of Wolbachia strains and their natural hosts is essential for future operationalization of this vector control strategy in Cuba.}, }
@article {pmid36897260, year = {2023}, author = {Reich, HG and Camp, EF and Roger, LM and Putnam, HM}, title = {The trace metal economy of the coral holobiont: supplies, demands and exchanges.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {98}, number = {2}, pages = {623-642}, doi = {10.1111/brv.12922}, pmid = {36897260}, issn = {1469-185X}, abstract = {The juxtaposition of highly productive coral reef ecosystems in oligotrophic waters has spurred substantial interest and progress in our understanding of macronutrient uptake, exchange, and recycling among coral holobiont partners (host coral, dinoflagellate endosymbiont, endolithic algae, fungi, viruses, bacterial communities). By contrast, the contribution of trace metals to the physiological performance of the coral holobiont and, in turn, the functional ecology of reef-building corals remains unclear. The coral holobiont's trace metal economy is a network of supply, demand, and exchanges upheld by cross-kingdom symbiotic partnerships. Each partner has unique trace metal requirements that are central to their biochemical functions and the metabolic stability of the holobiont. Organismal homeostasis and the exchanges among partners determine the ability of the coral holobiont to adjust to fluctuating trace metal supplies in heterogeneous reef environments. This review details the requirements for trace metals in core biological processes and describes how metal exchanges among holobiont partners are key to sustaining complex nutritional symbioses in oligotrophic environments. Specifically, we discuss how trace metals contribute to partner compatibility, ability to cope with stress, and thereby to organismal fitness and distribution. Beyond holobiont trace metal cycling, we outline how the dynamic nature of the availability of environmental trace metal supplies can be influenced by a variability of abiotic factors (e.g. temperature, light, pH, etc.). Climate change will have profound consequences on the availability of trace metals and further intensify the myriad stressors that influence coral survival. Lastly, we suggest future research directions necessary for understanding the impacts of trace metals on the coral holobiont symbioses spanning subcellular to organismal levels, which will inform nutrient cycling in coral ecosystems more broadly. Collectively, this cross-scale elucidation of the role of trace metals for the coral holobiont will allow us to improve forecasts of future coral reef function.}, }
@article {pmid36896707, year = {2023}, author = {McKnight, KS and Gissi, F and Adams, MS and Stone, S and Jolley, D and Stauber, J}, title = {The Effects of Nickel and Copper on Tropical Marine and Freshwater Microalgae Using Single and Multispecies Tests.}, journal = {Environmental toxicology and chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1002/etc.5565}, pmid = {36896707}, issn = {1552-8618}, abstract = {Microalgae are key components of aquatic food chains and are known to be sensitive to a range of contaminants. Much of the available data on metal toxicity to microalgae have been derived from temperate single-species tests with temperate data used to supplement tropical toxicity data sets to derive guideline values. In the present study, we used single-species and multispecies tests to investigate the toxicity of nickel and copper to tropical freshwater and marine microalgae, including the free-swimming stage of Symbiodinium sp., a worldwide coral endosymbiont. Based on the 10% effect concentration (EC10) for growth rate, copper was two to four times more toxic than nickel to all species tested. The temperate strain of Ceratoneis closterium was eight to 10 times more sensitive to nickel than the two tropical strains. Freshwater Monoraphidium arcuatum was less sensitive to copper and nickel in the multispecies tests compared with the single-species tests (EC10 values increasing from 0.45 to 1.4 µg Cu/L and from 62 to 330 µg Ni/L). The Symbiodinium sp. was sensitive to copper (EC10 of 3.1 µg Cu/L) and less sensitive to nickel (EC50 >1600 µg Ni/L). This is an important contribution of data on the chronic toxicity of nickel to Symbiodinium sp. A key result from the present study was that three microalgal species had EC10 values below the current copper water quality guideline value for 95% species protection in slightly to moderately disturbed systems in Australia and New Zealand, indicating that they may not be adequately protected by the current copper guideline value. By contrast, toxicity of nickel to microalgae is unlikely to occur at exposure concentrations typically found in fresh and marine waters. Environ Toxicol Chem 2023;00:1-13. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.}, }
@article {pmid36889655, year = {2023}, author = {Zhu, X and Liu, T and He, A and Zhang, L and Li, J and Li, T and Miao, X and You, M and You, S}, title = {Diversity of Wolbachia infection and its influence on mitochondrial DNA variation in the diamondback moth, Plutella xylostella.}, journal = {Molecular phylogenetics and evolution}, volume = {}, number = {}, pages = {107751}, doi = {10.1016/j.ympev.2023.107751}, pmid = {36889655}, issn = {1095-9513}, abstract = {Plutella xylostella is a pest that severely damages cruciferous vegetables worldwide and has been shown to be infected with the maternally inherited bacteria Wolbachia, with the main infected strain was plutWB1. In this study, we performed a large-scale global sampling of P. xylostella and amplified 3 mtDNA genes of P. xylostella and 6 Wolbachia genes to analyze the infection status, diversity of Wolbachia in P. xylostella, and its effect on mtDNA variation in P. xylostella. This study provides a conservative estimate of Wolbachia infection rates in P. xylostella, which was found to be 7% (104/1440). The ST 108 (plutWB1) was shared among butterfly species and the moth species P. xylostella, revealing that Wolbachia strain plutWB1 acquisition in P. xylostella may be through horizontal transmission. The Parafit analyses indicated a significant association between Wolbachia and Wolbachia-infected P. xylostella individuals, and individuals infected with plutWB1 tended to cluster in the basal positions of the phylogenetic tree based on the mtDNA data. Additionally, Wolbachia infections were associated with increased mtDNA polymorphism in the infected P. xylostella population. These data suggest that Wolbachia endosymbionts may have a potential effect on mtDNA variation of P. xylostella.}, }
@article {pmid36880348, year = {2023}, author = {Tholl, D and Rebholz, Z and Morozov, AV and O'Maille, PE}, title = {Terpene synthases and pathways in animals: enzymology and structural evolution in the biosynthesis of volatile infochemicals.}, journal = {Natural product reports}, volume = {}, number = {}, pages = {}, doi = {10.1039/d2np00076h}, pmid = {36880348}, issn = {1460-4752}, abstract = {Covering: up to the beginning of 2023Many animals release volatile or semi-volatile terpenes as semiochemicals in intra- and inter-specific interactions. Terpenes are important constituents of pheromones and serve as chemical defenses to ward off predators. Despite the occurrence of terpene specialized metabolites from soft corals to mammals, the biosynthetic origin of these compounds has largely remained obscure. An increasing number of animal genome and transcriptome resources is facilitating the identification of enzymes and pathways that allow animals to produce terpenes independent of their food sources or microbial endosymbionts. Substantial evidence has emerged for the presence of terpene biosynthetic pathways such as in the formation of the iridoid sex pheromone nepetalactone in aphids. In addition, terpene synthase (TPS) enzymes have been discovered that are evolutionary unrelated to canonical plant and microbial TPSs and instead resemble precursor enzymes called isoprenyl diphosphate synthases (IDSs) in central terpene metabolism. Structural modifications of substrate binding motifs in canonical IDS proteins presumably facilitated the transition to TPS function at an early state in insect evolution. Other arthropods such as mites appear to have adopted their TPS genes from microbial sources via horizontal gene transfer. A similar scenario likely occurred in soft corals, where TPS families with closer resemblance to microbial TPSs have been discovered recently. Together, these findings will spur the identification of similar or still unknown enzymes in terpene biosynthesis in other lineages of animals. They will also help develop biotechnological applications for animal derived terpenes of pharmaceutical value or advance sustainable agricultural practices in pest management.}, }
@article {pmid36869841, year = {2023}, author = {Cooper, WR and Walker, WB and Angelella, GM and Swisher Grimm, KD and Foutz, JJ and Harper, SJ and Nottingham, LB and Northfield, TD and Wohleb, CH and Strausbaugh, CA}, title = {Bacterial Endosymbionts Identified From Leafhopper (Hemiptera: Cicadellidae) Vectors of Phytoplasmas.}, journal = {Environmental entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/ee/nvad015}, pmid = {36869841}, issn = {1938-2936}, abstract = {Insects often harbor bacterial endosymbionts that provide them with nutritional benefit or with protection against natural enemies, plant defenses, insecticides, and abiotic stresses. Certain endosymbionts may also alter acquisition and transmission of plant pathogens by insect vectors. We identified bacterial endosymbionts from four leafhopper vectors (Hemiptera: Cicadellidae) of 'Candidatus Phytoplasma' species by direct sequencing 16S rDNA and confirmed endosymbiont presence and identity by species-specific conventional PCR. We examined three vectors of Ca. Phytoplasma pruni, causal agent of cherry X-disease [Colladonus geminatus (Van Duzee), Colladonus montanus reductus (Van Duzee), Euscelidius variegatus (Kirschbaum)] - and a vector of Ca. Phytoplasma trifolii, the causal agent of potato purple top disease [Circulifer tenellus (Baker)]. Direct sequencing of 16S identified the two obligate endosymbionts of leafhoppers, 'Ca. Sulcia' and 'Ca. Nasuia', which are known to produce essential amino acids lacking in the leafhoppers' phloem sap diet. About 57% of C. geminatus also harbored endosymbiotic Rickettsia. We identified 'Ca. Yamatotoia cicadellidicola' in Euscelidius variegatus, providing just the second host record for this endosymbiont. Circulifer tenellus harbored the facultative endosymbiont Wolbachia, although the average infection rate was only 13% and all males were Wolbachia-uninfected. A significantly greater percentage of Wolbachia-infected Ci. tenellus adults than uninfected adults carried Ca. P. trifolii, suggesting that Wolbachia may increase this insect's ability to tolerate or acquire this pathogen. Results of our study provide a foundation for continued work on interactions between leafhoppers, bacterial endosymbionts, and phytoplasma.}, }
@article {pmid36864565, year = {2023}, author = {Gossett, JM and Porter, ML and Vasquez, Y and Bennett, GM and Chong, RA}, title = {Genomic comparisons reveal selection pressure and functional variation between nutritional endosymbionts of cave-adapted and epigean Hawaiian planthoppers.}, journal = {Genome biology and evolution}, volume = {}, number = {}, pages = {}, doi = {10.1093/gbe/evad031}, pmid = {36864565}, issn = {1759-6653}, abstract = {Planthoppers in the family Cixiidae (Hempitera: Auchenorrhyncha: Fulgoromorpha) harbor a diverse set of obligate bacterial endosymbionts that provision essential amino acids and vitamins that are missing from their plant-sap diet. "Candidatus Sulcia muelleri", and "Ca. Vidania fulgoroidea" have been associated with cixiid planthoppers since their origin within the Auchenorrhyncha, while "Ca. Purcelliella pentastirinorum" is a more recent endosymbiotic acquisition. Hawaiian cixiid planthoppers occupy diverse habitats including lava tube caves and shrubby surface landscapes, which offer different nutritional resources and environmental constraints. Genomic studies have focused on understanding the nutritional provisioning roles of cixiid endosymbionts more broadly, yet it is still unclear how selection pressures on endosymbiont genes might differ between cixiid host species inhabiting such diverse landscapes, or how variation in selection might impact symbiont evolution. In this study, we sequenced the genomes of Sulcia, Vidania, and Purcelliella isolated from both surface and cave-adapted planthopper hosts from the genus Oliarus. We found that nutritional biosynthesis genes were conserved in Sulcia and Vidania genomes in inter- and intra-host species comparisons. In contrast, Purcelliella genomes retain different essential nutritional biosynthesis genes between surface- and cave-adapted planthopper species. Finally, we see variation in selection pressures on symbiont genes both within and between host species suggesting that strong coevolution between host and endosymbiont is associated with different patterns of molecular evolution on a fine scale that may be associated with host diet.}, }
@article {pmid36850014, year = {2023}, author = {Latrofa, MS and Varotto-Boccazzi, I and Louzada-Flores, VN and Iatta, R and Mendoza-Roldan, JA and Roura, X and Zatelli, A and Epis, S and Bandi, C and Otranto, D}, title = {Interaction between Wolbachia pipientis and Leishmania infantum in heartworm infected dogs.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {77}, pmid = {36850014}, issn = {1756-3305}, abstract = {BACKGROUND: Wolbachia is a Gram-negative endosymbiont associated with several species of arthropods and filarioid nematodes, including Dirofilaria immitis. This endosymbiont may elicit a Th1 response, which is a component of the immunity against Leishmania infantum.<br><br>METHODS: To investigate the interactions between Wolbachia of D. immitis and L. infantum in naturally infected dogs and cytokine circulation, dogs without clinical signs (n&#x2009;=&#x2009;187) were selected. Dogs were tested for microfilariae (mfs) by Knott, for female antigens of D. immitis by SNAP, and for anti-L. infantum antibodies by IFAT and assigned to four groups. Dogs of group 1 (G1) and 2 (G2) were positive for D. immitis and positive or negative to L. infantum, respectively. Dogs of group 3 (G3) and 4 (G4) were negative to D. immitis and positive or negative to L. infantum, respectively. Wolbachia and L. infantum DNA was quantified by real-time PCR (qPCR) in dog blood samples. A subset of dogs (n&#x2009;=&#x2009;65) was examined to assess pro- and anti-inflammatory cytokine production using an ELISA test.<br><br>RESULTS: Of 93 dogs positive to D. immitis with circulating mfs, 85% were positive to Wolbachia, with the highest amount of DNA detected in G1 and the lowest in dogs with low mfs load in G1 and G2. Among dogs positive to L. infantum, 66% from G1 showed low antibody titer, while 48.9% from G3 had the highest antibody titer. Of 37 dogs positive to Wolbachia from G1, 26 (70.3%) had low antibody titers to L. infantum (1:160). Among cytokines, TNF&#x3b1; showed the highest mean concentration in G1 (246.5&#xa0;pg/ml), IFN&#x3b3; being the one most represented (64.3%). IL-10 (1809.5&#xa0;pg/ml) and IL-6 (123.5&#xa0;pg/ml) showed the highest mean concentration in dogs from G1. A lower percentage of dogs producing IL-4 was observed in all groups examined, with the highest mean concentration (2794&#xa0;pg/ml) recorded in G2.<br><br>CONCLUSION: Results show the association of D. immitis and Wolbachia with the lower antibody titers of L. infantum in co-infected dogs, suggesting the hypothesis that the endosymbiont may affect the development of the patent leishmaniosis. However, due to the limitations associated with the heterogeneity of naturally infected dogs in field conditions, results should be validated by investigation on experimental models.}, }
@article {pmid36838431, year = {2023}, author = {Nencioni, A and Pastorelli, R and Bigiotti, G and Cucu, MA and Sacchetti, P}, title = {Diversity of the Bacterial Community Associated with Hindgut, Malpighian Tubules, and Foam of Nymphs of Two Spittlebug Species (Hemiptera: Aphrophoridae).}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020466}, pmid = {36838431}, issn = {2076-2607}, abstract = {Spittlebugs are xylem-sap feeding insects that can exploit a nutrient-poor diet, thanks to mutualistic endosymbionts residing in various organs of their body. Although obligate symbioses in some spittlebug species have been quite well studied, little is known about their facultative endosymbionts, especially those inhabiting the gut. Recently, the role played by spittlebugs as vectors of the phytopathogenetic bacterium Xylella fastidiosa aroused attention to this insect group, boosting investigations aimed at developing effective yet sustainable control strategies. Since spittlebug nymphs are currently the main target of applied control, the composition of gut bacterial community of the juveniles of Philaenus spumarius and Lepyronia coleoptrata was investigated using molecular techniques. Moreover, bacteria associated with their froth, sampled from different host plants, were studied. Results revealed that Sodalis and Rickettsia bacteria are the predominant taxa in the gut of P. spumarius and L. coleoptrata nymphs, respectively, while Rhodococcus was found in both species. Our investigations also highlighted the presence of recurring bacteria in the froth. Furthermore, the foam hosted several bacterial species depending on the host plant, the insect species, or on soil contaminant. Overall, first findings showed that nymphs harbor a large and diverse bacterial community in their gut and froth, providing new accounts to the knowledge on facultative symbionts of spittlebugs.}, }
@article {pmid36838405, year = {2023}, author = {Picciotti, U and Araujo Dalbon, V and Ciancio, A and Colagiero, M and Cozzi, G and De Bellis, L and Finetti-Sialer, MM and Greco, D and Ippolito, A and Lahbib, N and Logrieco, AF and López-Llorca, LV and Lopez-Moya, F and Luvisi, A and Mincuzzi, A and Molina-Acevedo, JP and Pazzani, C and Scortichini, M and Scrascia, M and Valenzano, D and Garganese, F and Porcelli, F}, title = {"Ectomosphere": Insects and Microorganism Interactions.}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020440}, pmid = {36838405}, issn = {2076-2607}, abstract = {This study focuses on interacting with insects and their ectosymbiont (lato sensu) microorganisms for environmentally safe plant production and protection. Some cases help compare ectosymbiont microorganisms that are insect-borne, -driven, or -spread relevant to endosymbionts' behaviour. Ectosymbiotic bacteria can interact with insects by allowing them to improve the value of their pabula. In addition, some bacteria are essential for creating ecological niches that can host the development of pests. Insect-borne plant pathogens include bacteria, viruses, and fungi. These pathogens interact with their vectors to enhance reciprocal fitness. Knowing vector-phoront interaction could considerably increase chances for outbreak management, notably when sustained by quarantine vector ectosymbiont pathogens, such as the actual Xylella fastidiosa Mediterranean invasion episode. Insect pathogenic viruses have a close evolutionary relationship with their hosts, also being highly specific and obligate parasites. Sixteen virus families have been reported to infect insects and may be involved in the biological control of specific pests, including some economic weevils. Insects and fungi are among the most widespread organisms in nature and interact with each other, establishing symbiotic relationships ranging from mutualism to antagonism. The associations can influence the extent to which interacting organisms can exert their effects on plants and the proper management practices. Sustainable pest management also relies on entomopathogenic fungi; research on these species starts from their isolation from insect carcasses, followed by identification using conventional light or electron microscopy techniques. Thanks to the development of omics sciences, it is possible to identify entomopathogenic fungi with evolutionary histories that are less-shared with the target insect and can be proposed as pest antagonists. Many interesting omics can help detect the presence of entomopathogens in different natural matrices, such as soil or plants. The same techniques will help localize ectosymbionts, localization of recesses, or specialized morphological adaptation, greatly supporting the robust interpretation of the symbiont role. The manipulation and modulation of ectosymbionts could be a more promising way to counteract pests and borne pathogens, mitigating the impact of formulates and reducing food insecurity due to the lesser impact of direct damage and diseases. The promise has a preventive intent for more manageable and broader implications for pests, comparing what we can obtain using simpler, less-specific techniques and a less comprehensive approach to Integrated Pest Management (IPM).}, }
@article {pmid36838257, year = {2023}, author = {Mashini, AG and Oakley, CA and Beepat, SS and Peng, L and Grossman, AR and Weis, VM and Davy, SK}, title = {The Influence of Symbiosis on the Proteome of the Exaiptasia Endosymbiont Breviolum minutum.}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020292}, pmid = {36838257}, issn = {2076-2607}, abstract = {The cellular mechanisms responsible for the regulation of nutrient exchange, immune response, and symbiont population growth in the cnidarian-dinoflagellate symbiosis are poorly resolved. Here, we employed liquid chromatography-mass spectrometry to elucidate proteomic changes associated with symbiosis in Breviolum minutum, a native symbiont of the sea anemone Exaiptasia diaphana ('Aiptasia'). We manipulated nutrients available to the algae in culture and to the holobiont in hospite (i.e., in symbiosis) and then monitored the impacts of our treatments on host-endosymbiont interactions. Both the symbiotic and nutritional states had significant impacts on the B. minutum proteome. B. minutum in hospite showed an increased abundance of proteins involved in phosphoinositol metabolism (e.g., glycerophosphoinositol permease 1 and phosphatidylinositol phosphatase) relative to the free-living alga, potentially reflecting inter-partner signalling that promotes the stability of the symbiosis. Proteins potentially involved in concentrating and fixing inorganic carbon (e.g., carbonic anhydrase, V-type ATPase) and in the assimilation of nitrogen (e.g., glutamine synthase) were more abundant in free-living B. minutum than in hospite, possibly due to host-facilitated access to inorganic carbon and nitrogen limitation by the host when in hospite. Photosystem proteins increased in abundance at high nutrient levels irrespective of the symbiotic state, as did proteins involved in antioxidant defences (e.g., superoxide dismutase, glutathione s-transferase). Proteins involved in iron metabolism were also affected by the nutritional state, with an increased iron demand and uptake under low nutrient treatments. These results detail the changes in symbiont physiology in response to the host microenvironment and nutrient availability and indicate potential symbiont-driven mechanisms that regulate the cnidarian-dinoflagellate symbiosis.}, }
@article {pmid36836374, year = {2023}, author = {Solanki, S and Lakshmi, GBVS and Dhiman, T and Gupta, S and Solanki, PR and Kapoor, R and Varma, A}, title = {Co-Application of Silver Nanoparticles and Symbiotic Fungus Piriformospora indica Improves Secondary Metabolite Production in Black Rice.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {2}, pages = {}, doi = {10.3390/jof9020260}, pmid = {36836374}, issn = {2309-608X}, abstract = {In the current research, unique Nano-Embedded Fungus (NEF), made by the synergic association of silver nanoparticles (AgNPs) and endophytic fungus (Piriformospora indica), is studied, and the impact of NEF on black rice secondary metabolites is reported. AgNPs were synthesized by chemical reduction process using the temperature-dependent method and characterized for morphological and structural features through UV visible absorption spectroscopy, zeta potential, XRD, SEM-EDX, and FTIR spectroscopy. The NEF, prepared by optimizing the AgNPs concentration (300 ppm) in agar and broth media, showed better fungal biomass, colony diameter, spore count, and spore size than the control P. indica. Treatment with AgNPs, P. indica, and NEF resulted in growth enhancement in black rice. NEF and AgNPs stimulated the production of secondary metabolites in its leaves. The concentrations of chlorophyll, carotenoids, flavonoids, and terpenoids were increased in plants inoculated with P. indica and AgNPs. The findings of the study highlight the synergistic effect of AgNPs and the fungal symbionts in augmenting the secondary metabolites in leaves of black rice.}, }
@article {pmid36828496, year = {2023}, author = {Kallu, SA and Ndebe, J and Qiu, Y and Nakao, R and Simuunza, MC}, title = {Prevalence and Association of Trypanosomes and Sodalis glossinidius in Tsetse Flies from the Kafue National Park in Zambia.}, journal = {Tropical medicine and infectious disease}, volume = {8}, number = {2}, pages = {}, doi = {10.3390/tropicalmed8020080}, pmid = {36828496}, issn = {2414-6366}, abstract = {Tsetse flies are obligate hematophagous vectors of animal and human African trypanosomosis. They cyclically transmit pathogenic Trypanosoma species. The endosymbiont Sodalis glossinidius is suggested to play a role in facilitating the susceptibility of tsetse flies to trypanosome infections. Therefore, this study was aimed at determining the prevalence of S. glossinidius and trypanosomes circulating in tsetse flies and checking whether an association exists between trypanosomes and Sodalis infections in tsetse flies from Kafue National Park in Zambia. A total of 326 tsetse flies were sampled from the Chunga and Ngoma areas of the national park. After DNA extraction was conducted, the presence of S. glossinidius and trypanosome DNA was checked using PCR. The Chi-square test was carried out to determine whether there was an association between the presence of S. glossinidius and trypanosome infections. Out of the total tsetse flies collected, the prevalence of S. glossinidius and trypanosomes was 21.8% and 19.3%, respectively. The prevalence of S. glossinidius was 22.2% in Glossina morsitans and 19.6% in Glossina pallidipes. In relation to sampling sites, the prevalence of S. glossinidius was 26.0% in Chunga and 21.0% in Ngoma. DNA of trypanosomes was detected in 18.9% of G. morsitans and 21.4% of G. pallidipes. The prevalence of trypanosomes was 21.7% and 6.0% for Ngoma and Chunga, respectively. The prevalences of trypanosome species detected in this study were 6.4%, 4.6%, 4.0%, 3.7%, 3.1%, and 2.5% for T. vivax, T. simiae, T. congolense, T. godfreyi, T. simiae Tsavo, and T. b. brucei, respectively. Out of 63 trypanosome infected tsetse flies, 47.6% of the flies also carried S. glossinidius, and the remaining flies were devoid of S. glossinidius. A statistically significant association was found between S. glossinidius and trypanosomes (p < 0.001) infections in tsetse flies. Our findings indicated that presence of S. glossinidius increases the susceptibility of tsetse flies to trypanosome infections and S. glossinidius could be a potential candidate for symbiont-mediated vector control in these tsetse species.}, }
@article {pmid36827319, year = {2023}, author = {Teal, E and Herrera, C and Dumonteil, E}, title = {Metabolomics of developmental changes in Triatoma sanguisuga gut microbiota.}, journal = {PloS one}, volume = {18}, number = {2}, pages = {e0280868}, doi = {10.1371/journal.pone.0280868}, pmid = {36827319}, issn = {1932-6203}, abstract = {Triatoma sanguisuga is one of the major vectors of Trypanosoma cruzi in the southeastern US, where it sustains a robust zoonotic parasite transmission cycle and occasional human infections. A better understanding of triatomine development may allow for alternative approaches to insecticide-based vector control. Indeed, the role of the gut microbiota and bacterial endosymbionts in triatomine development and in their vectorial capacity is emerging. We investigated here the differences in microbiota among nymph and adult T. sanguisuga, to shed light on the metabolomic interactions occurring during development. Microbiota composition was assessed by 16s gene amplification and deep sequencing from field-caught adult bugs and their laboratory-raised progeny. Significant differences in microbiota bacterial diversity and composition were observed between nymphs and adults. Laboratory-raised nymphs showed a higher taxonomic diversity, and at least seven families predominated. On the other hand, field-caught adults had a lower bacterial diversity and four families comprised most of the microbiota. These differences in compositions were associated with differences in predicted metabolism, with laboratory-raised nymphs microbiota metabolizing a limited diversity of carbon sources, with potential for resource competition between bacterial families, and the production of lactic acid as a predominant fermentation product. On the other hand, field-caught adult microbiota was predicted to metabolize a broader diversity of carbon sources, with complementarity rather than competition among taxa, and produced a diverse range of products in a more balanced manner. The restricted functionality of laboratory-raised nymph microbiota may be associated with their poor development in captivity, and further understanding of the metabolic interactions at play may lead to alternative vector control strategies targeting triatomine microbiota.}, }
@article {pmid36825089, year = {2023}, author = {Jiang, RX and Shang, F and Jiang, HB and Dou, W and Cernava, T and Wang, JJ}, title = {Candidatus Liberibacter asiaticus: An important factor affecting bacterial community composition and Wolbachia titers in Asian citrus psyllid.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1109803}, doi = {10.3389/fmicb.2023.1109803}, pmid = {36825089}, issn = {1664-302X}, abstract = {Endosymbionts play crucial roles in various physiological activities within insect hosts. The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is an important vector for Candidatus Liberibacter asiaticus (CLas), a fatal pathogenic bacterial agent causing the disease Huanglongbing in the citrus industry. This study combines high-throughput sequencing of 16S ribosomal RNA amplicons to explore how CLas affects the bacterial community in different color morphs (blue, gray), genders, and tissues (cuticle, gut, mycetome, Malpighian tubule, ovary, and testis) of ACP. We found that there was no significant differences in the bacterial community diversity and CLas acquired ratio between the different color morphs and genders of ACP adults. However, acquiring CLas could promote the adult bacterial community's diversity and richness more than in the uninfected condition. The presence of CLas could increase the Wolbachia and unclassified_Enterobacteriaceae proportions more than in the uninfected condition. The bacterial community diversity in the CLas infected tissues of ovary and cuticle, was lower than the uninfected condition, but the richness of all tissues was not different between the infected and uninfected conditions. CLas could also change the bacterial structure in different tissues and make the bacterial relationship network simpler than it is in an uninfected condition. Furthermore, we used quantitative real-time PCR to assess the dynamic changes of Wolbachia in CLas uninfected and infected color morphs and tissues of ACP. The results showed that Wolbachia titers were significantly higher in CLas infected adults than in uninfected adults. In different tissues, the Wolbachia titers in the testis, ovary, and Malpighian tubule were higher than their uninfected counterparts. Our results provide essential knowledge for understanding the symbionts of the ACP and how CLas affects the bacterial community of the ACP.}, }
@article {pmid36824530, year = {2022}, author = {Schultz, DL and Selberherr, E and Stouthamer, CM and Doremus, MR and Kelly, SE and Hunter, MS and Schmitz-Esser, S}, title = {Sex-based de novo transcriptome assemblies of the parasitoid wasp Encarsia suzannae, a host of the manipulative heritable symbiont Cardinium hertigii.}, journal = {GigaByte (Hong Kong, China)}, volume = {2022}, number = {}, pages = {gigabyte68}, doi = {10.46471/gigabyte.68}, pmid = {36824530}, issn = {2709-4715}, abstract = {Parasitoid wasps in the genus Encarsia are commonly used as biological pest control agents of whiteflies and armored scale insects in greenhouses or the field. They are also hosts of the bacterial endosymbiont Cardinium hertigii, which can cause reproductive manipulation phenotypes, including parthenogenesis, feminization, and cytoplasmic incompatibility (the last is mainly studied in Encarsia suzannae). Despite their biological and economic importance, there are no published Encarsia genomes and only one public transcriptome. Here, we applied a mapping-and-removal approach to eliminate known contaminants from previously-obtained Illumina sequencing data. We generated de novo transcriptome assemblies for both female and male E. suzannae which contain 45,986 and 54,762 final coding sequences, respectively. Benchmarking Single-Copy Orthologs results indicate both assemblies are highly complete. Preliminary analyses revealed the presence of homologs of sex-determination genes characterized in other insects and putative venom proteins. Our male and female transcriptomes will be valuable tools to better understand the biology of Encarsia and their evolutionary relatives, particularly in studies involving insects of only one sex.}, }
@article {pmid36810669, year = {2023}, author = {Manoj, RRS and Latrofa, MS and Louni, M and Laidoudi, Y and Fenollar, F and Otranto, D and Mediannikov, O}, title = {In vitro maintenance of the endosymbiont Wolbachia of Dirofilaria immitis.}, journal = {Parasitology research}, volume = {}, number = {}, pages = {}, pmid = {36810669}, issn = {1432-1955}, abstract = {Wolbachia has an obligatory mutualistic relationship with many onchocercid nematodes of the subfamilies Dirofilariinae and Onchocercinae. Till date, no attempts have been made for the in vitro cultivation of this intracellular bacterium from the filarioid host. Hence, the current study attempted cell co-culture method using embryonic Drosophila S2 and the LD cell lines to cultivate Wolbachia from Dirofilaria immitis microfilariae (mfs) harvested from infected dogs. Microfilariae (mfs = 1500) were inoculated in shell vials supplemented with Schneider medium using both cell lines. The establishment and multiplication of the bacterium were observed during the initial inoculation, at day 0 and before every medium change (from days 14 to 115). An aliquot (50 µl) from each time point was tested by quantitative real-time PCR (qPCR). Comparing the average of Ct values, obtained by the tested parameters (i.e., LD/S2 cell lines and mfs with/without treatment), the S2 cell line without mechanical disruption of mfs provided the highest Wolbachia cell count by qPCR. Despite the maintenance of Wolbachia within both S2 and LD-based cell co-culture models for up to 115 days, a definitive conclusion is still far. Further trials using fluorescent microscopy and viable staining will help to demonstrate the cell line infection and viability of Wolbachia. Use of considerable amount of untreated mfs to inoculate the Drosophilia S2 cell lines, as well as the supplementation of the culture media with growth stimulants or pre-treated cells to increase their susceptibility for the infection and development of a filarioid-based cell line system are recommended for the future trials.}, }
@article {pmid36810610, year = {2023}, author = {Muro, T and Hikida, H and Fujii, T and Kiuchi, T and Katsuma, S}, title = {Two Complete Genomes of Male-Killing Wolbachia Infecting Ostrinia Moth Species Illuminate Their Evolutionary Dynamics and Association with Hosts.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {36810610}, issn = {1432-184X}, abstract = {Wolbachia is an extremely widespread intracellular symbiont which causes reproductive manipulation on various arthropod hosts. Male progenies are killed in Wolbachia-infected lineages of the Japanese Ostrinia moth population. While the mechanism of male killing and the evolutionary interaction between host and symbiont are significant concerns for this system, the absence of Wolbachia genomic information has limited approaches to these issues. We determined the complete genome sequences of wFur and wSca, the male-killing Wolbachia of Ostrinia furnacalis and Ostrinia scapulalis. The two genomes shared an extremely high degree of homology, with over 95% of the predicted protein sequences being identical. A comparison of these two genomes revealed nearly minimal genome evolution, with a strong emphasis on the frequent genome rearrangements and the rapid evolution of ankyrin repeat-containing proteins. Additionally, we determined the mitochondrial genomes of both species' infected lineages and performed phylogenetic analyses to deduce the evolutionary dynamics of Wolbachia infection in the Ostrinia clade. According to the inferred phylogenetic relationship, two possible scenarios were proposed: (1) Wolbachia infection was established in the Ostrinia clade prior to the speciation of related species such as O. furnacalis and O. scapulalis, or (2) Wolbachia infection in these species was introgressively transferred from a currently unidentified relative. Simultaneously, the relatively high homology of mitochondrial genomes suggested recent Wolbachia introgression between infected Ostrinia species. The findings of this study collectively shed light on the host-symbiont interaction from an evolutionary standpoint.}, }
@article {pmid36809083, year = {2023}, author = {De la Vega, P and Shimpi, GG and Bentlage, B}, title = {Genome Sequence of the Endosymbiont Endozoicomonas sp. Strain GU-1 (Gammaproteobacteria), Isolated from the Staghorn Coral Acropora pulchra (Cnidaria: Scleractinia).}, journal = {Microbiology resource announcements}, volume = {}, number = {}, pages = {e0135522}, doi = {10.1128/mra.01355-22}, pmid = {36809083}, issn = {2576-098X}, abstract = {Endozoicomonas sp. strain GU-1 was isolated from two separate staghorn coral (Acropora pulchra) colonies collected in Guam, Micronesia. Both isolates were grown in marine broth prior to DNA extraction and Oxford Nanopore Technologies (ONT) sequencing. Genomes were approximately 6.1 Mbp in size, containing highly similar gene content and matching sets of rRNA sequences.}, }
@article {pmid36801155, year = {2023}, author = {Ogier, JC and Akhurst, R and Boemare, N and Gaudriault, S}, title = {The endosymbiont and the second bacterial circle of entomopathogenic nematodes.}, journal = {Trends in microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.tim.2023.01.004}, pmid = {36801155}, issn = {1878-4380}, abstract = {Single host-symbiont interactions should be reconsidered from the perspective of the pathobiome. We revisit here the interactions between entomopathogenic nematodes (EPNs) and their microbiota. We first describe the discovery of these EPNs and their bacterial endosymbionts. We also consider EPN-like nematodes and their putative symbionts. Recent high-throughput sequencing studies have shown that EPNs and EPN-like nematodes are also associated with other bacterial communities, referred to here as the second bacterial circle of EPNs. Current findings suggest that some members of this second bacterial circle contribute to the pathogenic success of nematodes. We suggest that the endosymbiont and the second bacterial circle delimit an EPN pathobiome.}, }
@article {pmid36800397, year = {2023}, author = {Mills, MK and McCabe, LG and Rodrigue, EM and Lechtreck, KF and Starai, VJ}, title = {Wbm0076, a candidate effector protein of the Wolbachia endosymbiont of Brugia malayi, disrupts eukaryotic actin dynamics.}, journal = {PLoS pathogens}, volume = {19}, number = {2}, pages = {e1010777}, doi = {10.1371/journal.ppat.1010777}, pmid = {36800397}, issn = {1553-7374}, abstract = {Brugia malayi, a parasitic roundworm of humans, is colonized by the obligate intracellular bacterium, Wolbachia pipientis. The symbiosis between this nematode and bacterium is essential for nematode reproduction and long-term survival in a human host. Therefore, identifying molecular mechanisms required by Wolbachia to persist in and colonize B. malayi tissues will provide new essential information regarding the basic biology of this endosymbiosis. Wolbachia utilize a Type IV secretion system to translocate so-called "effector" proteins into the cytosol of B. malayi cells to promote colonization of the eukaryotic host. However, the characterization of these Wolbachia secreted proteins has remained elusive due to the genetic intractability of both organisms. Strikingly, expression of the candidate Wolbachia Type IV-secreted effector protein, Wbm0076, in the surrogate eukaryotic cell model, Saccharomyces cerevisiae, resulted in the disruption of the yeast actin cytoskeleton and inhibition of endocytosis. Genetic analyses show that Wbm0076 is a member of the family of Wiskott-Aldrich syndrome proteins (WAS [p]), a well-conserved eukaryotic protein family required for the organization of actin skeletal structures. Thus, Wbm0076 likely plays a central role in the active cell-to-cell movement of Wolbachia throughout B. malayi tissues during nematode development. As most Wolbachia isolates sequenced to date encode at least partial orthologs of wBm0076, we find it likely that the ability of Wolbachia to directly manipulate host actin dynamics is an essential requirement of all Wolbachia endosymbioses, independent of host cell species.}, }
@article {pmid36793689, year = {2023}, author = {Matias, AMA and Popovic, I and Thia, JA and Cooke, IR and Torda, G and Lukoschek, V and Bay, LK and Kim, SW and Riginos, C}, title = {Cryptic diversity and spatial genetic variation in the coral Acropora tenuis and its endosymbionts across the Great Barrier Reef.}, journal = {Evolutionary applications}, volume = {16}, number = {2}, pages = {293-310}, pmid = {36793689}, issn = {1752-4571}, abstract = {Genomic studies are uncovering extensive cryptic diversity within reef-building corals, suggesting that evolutionarily and ecologically relevant diversity is highly underestimated in the very organisms that structure coral reefs. Furthermore, endosymbiotic algae within coral host species can confer adaptive responses to environmental stress and may represent additional axes of coral genetic variation that are not constrained by taxonomic divergence of the cnidarian host. Here, we examine genetic variation in a common and widespread, reef-building coral, Acropora tenuis, and its associated endosymbiotic algae along the entire expanse of the Great Barrier Reef (GBR). We use SNPs derived from genome-wide sequencing to characterize the cnidarian coral host and organelles from zooxanthellate endosymbionts (genus Cladocopium). We discover three distinct and sympatric genetic clusters of coral hosts, whose distributions appear associated with latitude and inshore-offshore reef position. Demographic modelling suggests that the divergence history of the three distinct host taxa ranges from 0.5 to 1.5 million years ago, preceding the GBR's formation, and has been characterized by low-to-moderate ongoing inter-taxon gene flow, consistent with occasional hybridization and introgression typifying coral evolution. Despite this differentiation in the cnidarian host, A. tenuis taxa share a common symbiont pool, dominated by the genus Cladocopium (Clade C). Cladocopium plastid diversity is not strongly associated with host identity but varies with reef location relative to shore: inshore colonies contain lower symbiont diversity on average but have greater differences between colonies as compared with symbiont communities from offshore colonies. Spatial genetic patterns of symbiont communities could reflect local selective pressures maintaining coral holobiont differentiation across an inshore-offshore environmental gradient. The strong influence of environment (but not host identity) on symbiont community composition supports the notion that symbiont community composition responds to habitat and may assist in the adaptation of corals to future environmental change.}, }
@article {pmid36786616, year = {2023}, author = {Li, C and Liu, S and Zhou, H and Zhu, W and Cui, M and Li, J and Wang, J and Liu, J and Zhu, J and Li, W and Bi, Y and Carr, MJ and Holmes, EC and Shi, W}, title = {Metatranscriptomic Sequencing Reveals Host Species as an Important Factor Shaping the Mosquito Virome.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0465522}, doi = {10.1128/spectrum.04655-22}, pmid = {36786616}, issn = {2165-0497}, abstract = {Mosquitoes are important vector hosts for numerous viral pathogens and harbor a large number of mosquito-specific viruses as well as human-infecting viruses. Previous studies have mainly focused on the discovery of mosquito viruses, and our understanding of major ecological factors associated with virome structure in mosquitoes remains limited. We utilized metatranscriptomic sequencing to characterize the viromes of five mosquito species sampled across eight locations in Yunnan Province, China. This revealed the presence of 52 viral species, of which 19 were novel, belonging to 15 viral families/clades. Of particular note was Culex hepacivirus 1, clustering within the avian clade of hepaciviruses. Notably, both the viromic diversity and abundance of Aedes genus mosquitoes were significantly higher than those of the Culex genus, while Aedes albopictus mosquitoes harbored a higher diversity than Aedes aegypti mosquitoes. Our findings thus point to discernible differences in viromic structure between mosquito genera and even between mosquito species within the same genus. Importantly, such differences were not attributable to differences in sampling between geographical location. Our study also revealed the ubiquitous presence of the endosymbiont bacterium Wolbachia, with the genetic diversity and abundance also varying between mosquito species. In conclusion, our results suggested that the mosquito host species play an important role in shaping the virome's structure. IMPORTANCE This study revealed the huge capability of mosquitoes in harboring a rich diversity of RNA viruses, although relevant studies have characterized the intensively unparalleled diversity of RNA viruses previously. Furthermore, our findings showed discernible differences not only in viromic structure between mosquito genera and even between mosquito species within the same genus but also in the genetic diversity and abundance of Wolbachia between different mosquito populations. These findings emphasize the importance of host genetic background in shaping the virome composition of mosquitoes.}, }
@article {pmid36785954, year = {2023}, author = {Sanaei, E and Albery, GF and Yeoh, YK and Lin, YP and Cook, LG and Engelstädter, J}, title = {Host phylogeny and ecological associations best explain Wolbachia host shifts in scale insects.}, journal = {Molecular ecology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mec.16883}, pmid = {36785954}, issn = {1365-294X}, abstract = {Wolbachia are among the most prevalent and widespread endosymbiotic bacteria on earth. Wolbachia's success in infecting an enormous number of arthropod species is attributed to two features: the range of phenotypes they induce in their hosts, and their ability to switch between host species. Whilst much progress has been made in elucidating their induced phenotypes, our understanding of Wolbachia host shifting is still very limited: we lack answers to even fundamental questions concerning Wolbachia's routes of transfer and the importance of factors influencing host shifts. Here, we investigate the diversity and host-shift patterns of Wolbachia in scale insects, a group of arthropods with intimate associations with other insects that make them well-suited to studying host shifts. Using Illumina multi-target amplicon sequencing of Wolbachia-infected scale insects and their direct associates we determined the identity of all Wolbachia strains. We then fitted a Generalised Additive Mixed Model (GAMM) to our data to estimate the influence of host phylogeny and the geographic distribution on Wolbachia strain sharing among scale insect species. The model predicts no significant contribution of host geography but strong effects of host phylogeny, with high rates of Wolbachia sharing among closely related species and a sudden drop-off in sharing with increasing phylogenetic distance. We also detected the same Wolbachia strain in scale insects and several intimately associated species (ants, wasps, and flies). This indicates putative host shifts and potential routes of transfers via these associates and highlights the importance of ecological connectivity in Wolbachia host-shifting.}, }
@article {pmid36781724, year = {2023}, author = {Takasuka, K and Arakawa, K}, title = {The Method of Eliminating the Wolbachia Endosymbiont Genomes from Insect Samples Prior to a Long-Read Sequencing.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2632}, number = {}, pages = {101-112}, pmid = {36781724}, issn = {1940-6029}, abstract = {When extracting DNA of invertebrates for long-read sequencing, not only enough quantity and size of the DNA but, depending on the species, elimination of contamination of endosymbiotic Wolbachia genome also has to be achieved. These requirements become troublesome, especially in small-sized species with a limited number of individuals available for the experiment. In this chapter, using tiny parasitoid wasps (Reclinervellus nielseni) parasitizing spiders as hosts, we developed a method of eliminating the Wolbachia genomes by means of an antibiotic administration to adult wasps via honey solution. Twenty days of rifampicin treatment since their emergence from cocoons resulted in a significant decrease in the Wolbachia genomes while keeping good DNA conditions for nanopore sequencing. An adequate quantity of DNA was then gained by pooling several individuals. The method could be applied to other insects or invertebrates that can be maintained by laboratory feeding with liquid food.}, }
@article {pmid36779765, year = {2023}, author = {Dell'Aglio, E and Lacotte, V and Peignier, S and Rahioui, I and Benzaoui, F and Vallier, A and Da Silva, P and Desouhant, E and Heddi, A and Rebollo, R}, title = {Weevil Carbohydrate Intake Triggers Endosymbiont Proliferation: A Trade-Off between Host Benefit and Endosymbiont Burden.}, journal = {mBio}, volume = {}, number = {}, pages = {e0333322}, doi = {10.1128/mbio.03333-22}, pmid = {36779765}, issn = {2150-7511}, abstract = {Nutritional symbioses between insects and intracellular bacteria (endosymbionts) are a major force of adaptation, allowing animals to colonize nutrient-poor ecological niches. Many beetles feeding on tyrosine-poor substrates rely on a surplus of aromatic amino acids produced by bacterial endosymbionts. This surplus of aromatic amino acids is crucial for the biosynthesis of a thick exoskeleton, the cuticle, which is made of a matrix of chitin with proteins and pigments built from tyrosine-derived molecules, providing an important defensive barrier against biotic and abiotic stress. Other endosymbiont-related advantages for beetles include faster development and improved fecundity. The association between Sitophilus oryzae and the Sodalis pierantonius endosymbiont represents a unique case study among beetles: endosymbionts undergo an exponential proliferation in young adults concomitant with the cuticle tanning, and then they are fully eliminated. While endosymbiont clearance, as well as total endosymbiont titer, are host-controlled processes, the mechanism triggering endosymbiont exponential proliferation remains poorly understood. Here, we show that endosymbiont exponential proliferation relies on host carbohydrate intake, unlike the total endosymbiont titer or the endosymbiont clearance, which are under host genetic control. Remarkably, insect fecundity was preserved, and the cuticle tanning was achieved, even when endosymbiont exponential proliferation was experimentally blocked, except in the context of a severely unbalanced diet. Moreover, a high endosymbiont titer coupled with nutrient shortage dramatically impacted host survival, revealing possible environment-dependent disadvantages for the host, likely due to the high energy cost of exponentially proliferating endosymbionts. IMPORTANCE Beetles thriving on tyrosine-poor diet sources often develop mutualistic associations with endosymbionts able to synthesize aromatic amino acids. This surplus of aromatic amino acids is used to reinforce the insect's protective cuticle. An exceptional feature of the Sitophilus oryzae/Sodalis pierantonius interaction is the exponential increase in endosymbiotic titer observed in young adult insects, in concomitance with cuticle biosynthesis. Here, we show that host carbohydrate intake triggers endosymbiont exponential proliferation, even in conditions that lead to the detriment of the host survival. In addition, when hosts thrive on a balanced diet, endosymbiont proliferation is dispensable for several host fitness traits. The endosymbiont exponential proliferation is therefore dependent on the nutritional status of the host, and its consequences on host cuticle biosynthesis and survival depend on food quality and availability.}, }
@article {pmid36778977, year = {2022}, author = {Sinha, DK and Gupta, A and Padmakumari, AP and Bentur, JS and Nair, S}, title = {Infestation of Rice by Gall Midge Influences Density and Diversity of Pseudomonas and Wolbachia in the Host Plant Microbiome.}, journal = {Current genomics}, volume = {23}, number = {2}, pages = {126-136}, pmid = {36778977}, issn = {1389-2029}, abstract = {Background: The virulence of phytophagous insects is predominantly determined by their ability to evade or suppress host defense for their survival. The rice gall midge (GM, Orseolia oryzae), a monophagous pest of rice, elicits a host defense similar to the one elicited upon pathogen attack. This could be due to the GM feeding behaviour, wherein the GM endosymbionts are transferred to the host plant via oral secretions, and as a result, the host mounts an appropriate defense response(s) (i.e., up-regulation of the salicylic acid pathway) against these endosymbionts. Methods: The current study aimed to analyze the microbiome present at the feeding site of GM maggots to determine the exchange of bacterial species between GM and its host and to elucidate their role in rice-GM interaction using a next-generation sequencing approach. Results: Our results revealed differential representation of the phylum Proteobacteria in the GM-infested and -uninfested rice tissues. Furthermore, analysis of the species diversity of Pseudomonas and Wolbachia supergroups at the feeding sites indicated the exchange of bacterial species between GM and its host upon infestation. Conclusion: As rice-GM microbial associations remain relatively unstudied, these findings not only add to our current understanding of microbe-assisted insect-plant interactions but also provide valuable insights into how these bacteria drive insect-plant coevolution. Moreover, to the best of our knowledge, this is the first report analyzing the microbiome of a host plant (rice) at the feeding site of its insect pest (GM).}, }
@article {pmid36769231, year = {2023}, author = {Tarlachkov, SV and Efeykin, BD and Castillo, P and Evtushenko, LI and Subbotin, SA}, title = {Distribution of Bacterial Endosymbionts of the Cardinium Clade in Plant-Parasitic Nematodes.}, journal = {International journal of molecular sciences}, volume = {24}, number = {3}, pages = {}, doi = {10.3390/ijms24032905}, pmid = {36769231}, issn = {1422-0067}, abstract = {Bacteria of the genus "Candidatus Cardinium" and related organisms composing the Cardinium clade are intracellular endosymbionts frequently occurring in several arthropod groups, freshwater mussels and plant-parasitic nematodes. Phylogenetic analyses based on two gene sequences (16S rRNA and gyrB) showed that the Cardinium clade comprised at least five groups: A, B, C, D and E. In this study, a screening of 142 samples of plant-parasitic nematodes belonging to 93 species from 12 families and two orders using PCR with specific primers and sequencing, revealed bacteria of Cardinium clade in 14 nematode samples belonging to 12 species of cyst nematodes of the family Heteroderidae. Furthermore, in this study, the genome of the Cardinium cHhum from the hop cyst nematode, Heterodera humuli, was also amplified, sequenced and analyzed. The comparisons of the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values for the strain Cardinium cHhum with regard to related organisms with available genomes, combined with the data on 16S rRNA and gyrB gene sequence identities, showed that this strain represents a new candidate species within the genus "Candidatus Paenicardinium". The phylogenetic position of endosymbionts of the Cardinium clade detected in nematode hosts was also compared to known representatives of this clade from other metazoans. Phylogenetic reconstructions based on analysis of 16S rRNA, gyrB, sufB, gloEL, fusA, infB genes and genomes and estimates of genetic distances both indicate that the endosymbiont of the root-lesion nematode Pratylenchus penetrans represented a separate lineage and is designated herein as a new group F. The phylogenetic analysis also confirmed that endosymbionts of ostracods represent the novel group G. Evolutionary relationships of bacterial endosymbionts of the Cardinium clade within invertebrates are presented and discussed.}, }
@article {pmid36757767, year = {2023}, author = {Halter, T and Köstlbacher, S and Rattei, T and Hendrickx, F and Manzano-Marín, A and Horn, M}, title = {One to host them all: genomics of the diverse bacterial endosymbionts of the spider Oedothorax gibbosus.}, journal = {Microbial genomics}, volume = {9}, number = {2}, pages = {}, doi = {10.1099/mgen.0.000943}, pmid = {36757767}, issn = {2057-5858}, abstract = {Bacterial endosymbionts of the groups Wolbachia, Cardinium and Rickettsiaceae are well known for their diverse effects on their arthropod hosts, ranging from mutualistic relationships to reproductive phenotypes. Here, we analysed a unique system in which the dwarf spider Oedothorax gibbosus is co-infected with up to five different endosymbionts affiliated with Wolbachia, 'Candidatus Tisiphia' (formerly Torix group Rickettsia), Cardinium and Rhabdochlamydia. Using short-read genome sequencing data, we show that the endosymbionts are heterogeneously distributed among O. gibbosus populations and are frequently found co-infecting spider individuals. To study this intricate host-endosymbiont system on a genome-resolved level, we used long-read sequencing to reconstruct closed genomes of the Wolbachia, 'Ca. Tisiphia' and Cardinium endosymbionts. We provide insights into the ecology and evolution of the endosymbionts and shed light on the interactions with their spider host. We detected high quantities of transposable elements in all endosymbiont genomes and provide evidence that ancestors of the Cardinium, 'Ca. Tisiphia' and Wolbachia endosymbionts have co-infected the same hosts in the past. Our findings contribute to broadening our knowledge about endosymbionts infecting one of the largest animal phyla on Earth and show the usefulness of transposable elements as an evolutionary 'contact-tracing' tool.}, }
@article {pmid36755874, year = {2022}, author = {Du, S and Ye, F and Xu, S and Liang, Y and Wan, F and Guo, J and Liu, W}, title = {Apomixis for no bacteria-induced thelytoky in Diglyphus wani (Hymenoptera: Eulophidae).}, journal = {Frontiers in genetics}, volume = {13}, number = {}, pages = {1061100}, pmid = {36755874}, issn = {1664-8021}, abstract = {In Hymenoptera species, the reproductive mode is usually arrhenotoky, where haploid males arise from unfertilized eggs and diploid females from fertilized eggs. In addition, a few species reproduce by thelytoky, where diploid females arise from unfertilized eggs. Diploid females can be derived through various cytological mechanisms in thelytokous Hymenoptera species. Hitherto, these mechanisms were revealed mainly in endosymbiont-induced thelytokous Hymenoptera species. In contrast, thelytokous Hymenoptera species in which a reproductive manipulator has not been verified or several common endosymbionts have been excluded were paid less attention in their cytological mechanisms, for instance, Diglyphus wani (Hymenoptera: Eulophidae). Here, we investigated the cytological mechanism of D. wani using cytological methods and genetic markers. Our observations indicated that the diploid karyotypes of two strains of D. wani consist of four pairs of relatively large metacentric chromosomes and one pair of short submetacentric chromosomes (2n = 10). The arrhenotokous strains could complete normal meiosis, whereas the thelytokous strain lacked meiosis and did not expulse any polar bodies. This reproductive type of lacking meiosis is classified as apomictic thelytoky. Moreover, a total of 636 microsatellite sequences were obtained from thelytokous D. wani, dominated by dinucleotide repeats. Genetic markers results showed all three generations of offspring from thelytokous strain maintained the same genotype as their parents. Our results revealed that D. wani is the first eulophid parasitoid wasp in Hymenoptera whose thelytoky was not induced by bacteria to form an apomictic thelytoky. These findings provide a baseline for future inner molecular genetic studies of ameiotic thelytoky.}, }
@article {pmid36754115, year = {2023}, author = {Prigot-Maurice, C and Lheraud, B and Guéritault, S and Beltran-Bech, S and Cordaux, R and Peccoud, J and Braquart-Varnier, C}, title = {Investigating Wolbachia symbiont-mediated host protection against a bacterial pathogen using a natural Wolbachia nuclear insert.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {107893}, doi = {10.1016/j.jip.2023.107893}, pmid = {36754115}, issn = {1096-0805}, abstract = {Wolbachia bacterial endosymbionts provide protection against pathogens in various arthropod species but the underlying mechanisms remain misunderstood. By using a natural Wolbachia nuclear insert (f-element) in the isopod Armadillidium vulgare, we explored whether Wolbachia presence is mandatory to observe protection in this species or the presence of its genes is sufficient. We assessed survival of closely related females carrying or lacking the f-element (and lacking Wolbachia) challenged with the bacterial pathogen Salmonella enterica. Despite marginal significant effects, the f-element alone did not appear to confer survival benefits to its host, suggesting that Wolbachia presence in cells is crucial for protection.}, }
@article {pmid36750192, year = {2023}, author = {Haydon, TD and Matthews, JL and Seymour, JR and Raina, JB and Seymour, JE and Chartrand, K and Camp, EF and Suggett, DJ}, title = {Metabolomic signatures of corals thriving across extreme reef habitats reveal strategies of heat stress tolerance.}, journal = {Proceedings. Biological sciences}, volume = {290}, number = {1992}, pages = {20221877}, doi = {10.1098/rspb.2022.1877}, pmid = {36750192}, issn = {1471-2954}, abstract = {Anthropogenic stressors continue to escalate worldwide, driving unprecedented declines in reef environmental conditions and coral health. One approach to better understand how corals can function in the future is to examine coral populations that thrive within present day naturally extreme habitats. We applied untargeted metabolomics (gas chromatography-mass spectrometry (GC-MS)) to contrast metabolite profiles of Pocillopora acuta colonies from hot, acidic and deoxygenated mangrove environments versus those from adjacent reefs. Under ambient temperatures, P. acuta predominantly associated with endosymbionts of the genera Cladocopium (reef) or Durusdinium (mangrove), exhibiting elevated metabolism in mangrove through energy-generating and biosynthesis pathways compared to reef populations. Under transient heat stress, P. acuta endosymbiont associations were unchanged. Reef corals bleached and exhibited extensive shifts in symbiont metabolic profiles (whereas host metabolite profiles were unchanged). By contrast, mangrove populations did not bleach and solely the host metabolite profiles were altered, including cellular responses in inter-partner signalling, antioxidant capacity and energy storage. Thus mangrove P. acuta populations resist periodically high-temperature exposure via association with thermally tolerant endosymbionts coupled with host metabolic plasticity. Our findings highlight specific metabolites that may be biomarkers of heat tolerance, providing novel insight into adaptive coral resilience to elevated temperatures.}, }
@article {pmid36748607, year = {2022}, author = {Giannotti, D and Boscaro, V and Husnik, F and Vannini, C and Keeling, PJ}, title = {At the threshold of symbiosis: the genome of obligately endosymbiotic 'Candidatus Nebulobacter yamunensis' is almost indistinguishable from that of a cultivable strain.}, journal = {Microbial genomics}, volume = {8}, number = {12}, pages = {}, doi = {10.1099/mgen.0.000909}, pmid = {36748607}, issn = {2057-5858}, abstract = {Comparing obligate endosymbionts with their free-living relatives is a powerful approach to investigate the evolution of symbioses, and it has led to the identification of several genomic traits consistently associated with the establishment of symbiosis. 'Candidatus Nebulobacter yamunensis' is an obligate bacterial endosymbiont of the ciliate Euplotes that seemingly depends on its host for survival. A subsequently characterized bacterial strain with an identical 16S rRNA gene sequence, named Fastidiosibacter lacustris, can instead be maintained in pure culture. We analysed the genomes of 'Candidatus Nebulobacter' and Fastidiosibacter seeking to identify key differences between their functional traits and genomic structure that might shed light on a recent transition to obligate endosymbiosis. Surprisingly, we found almost no such differences: the two genomes share a high level of sequence identity, the same overall structure, and largely overlapping sets of genes. The similarities between the genomes of the two strains are at odds with their different ecological niches, confirmed here with a parallel growth experiment. Although other pairs of closely related symbiotic/free-living bacteria have been compared in the past, 'Candidatus Nebulobacter' and Fastidiosibacter represent an extreme example proving that a small number of (unknown) factors might play a pivotal role in the earliest stages of obligate endosymbiosis establishment.}, }
@article {pmid36748430, year = {2022}, author = {Izraeli, Y and Lepetit, D and Atias, S and Mozes-Daube, N and Wodowski, G and Lachman, O and Luria, N and Steinberg, S and Varaldi, J and Zchori-Fein, E and Chiel, E}, title = {Genomic characterization of viruses associated with the parasitoid Anagyrus vladimiri (Hymenoptera: Encyrtidae).}, journal = {The Journal of general virology}, volume = {103}, number = {12}, pages = {}, doi = {10.1099/jgv.0.001810}, pmid = {36748430}, issn = {1465-2099}, abstract = {Knowledge on symbiotic microorganisms of insects has increased dramatically in recent years, yet relatively little data are available regarding non-pathogenic viruses. Here we studied the virome of the parasitoid wasp Anagyrus vladimiri Triapitsyn (Hymenoptera: Encyrtidae), a biocontrol agent of mealybugs. By high-throughput sequencing of viral nucleic acids, we revealed three novel viruses, belonging to the families Reoviridae [provisionally termed AnvRV (Anagyrus vladimiri reovirus)], Iflaviridae (AnvIFV) and Dicistroviridae (AnvDV). Phylogenetic analysis further classified AnvRV in the genus Idnoreovirus, and AnvDV in the genus Triatovirus. The genome of AnvRV comprises 10 distinct genomic segments ranging in length from 1.5 to 4.2 kb, but only two out of the 10 ORFs have a known function. AnvIFV and AnvDV each have one polypeptide ORF, which is typical of iflaviruses but very un-common among dicistroviruses. Five conserved domains were found along both the ORFs of those two viruses. AnvRV was found to be fixed in an A. vladimiri population that was obtained from a mass rearing facility, whereas its prevalence in field-collected A. vladimiri was ~15 %. Similarly, the prevalence of AnvIFV and AnvDV was much higher in the mass rearing population than in the field population. The presence of AnvDV was positively correlated with the presence of Wolbachia in the same individuals. Transmission electron micrographs of females' ovaries revealed clusters and viroplasms of reovirus-like particles in follicle cells, suggesting that AnvRV is vertically transmitted from mother to offspring. AnvRV was not detected in the mealybugs, supporting the assumption that this virus is truly associated with the wasps. The possible effects of these viruses on A. vladimiri's biology, and on biocontrol agents in general, are discussed. Our findings identify RNA viruses as potentially involved in the multitrophic system of mealybugs, their parasitoids and other members of the holobiont.}, }
@article {pmid36744984, year = {2023}, author = {Banerjee, P and Sarkar, A and Ghosh, K and Mazumdar, A}, title = {A Metagenomic Based Approach on Abundance and Diversity of Bacterial Communities Across the Life Stages of Culicoides peregrinus (Diptera: Ceratopogonidae) a Vector of Bluetongue Virus.}, journal = {Journal of medical entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jme/tjad011}, pmid = {36744984}, issn = {1938-2928}, abstract = {During larval rearing of Culicoides peregrinus Kieffer (Diptera: Ceratopogonidae) it was obligatory to add a small quantity of mud from larval habitat to nutrient broth in culture plates. This initiated microbial growth in rearing plates which facilitated growth and development of immature. The primary aim was to enumerate gut microbial communities across the different life stages of C. peregrinus. Amplicon sequencing of the V3-V4 hypervariable region (16S rDNA) was done on Illumina Miseq platform to detect gut bacterial communities at different life stages, while ITS regions (18S rRNA) were targeted for fungal communities of the 4th instar larvae. The major findings were: 1) Phylum Proteobacteria and Firmicutes were the most abundant throughout the life stages, along with the highest bacterial alpha diversity in the egg, 2) bacterial compositions were similar to laboratory reared and field collected adults, and 3) abundant fungal phyla associated with the larval gut were Ascomycota and Basidiomycota. Furthermore, analyses of the gut microbiome with METAGENassist might be indicative of their likely function in the natural habitat. Abundant gut-associated bacteria and/or fungal genera detected in the present study could be used as dietary supplements to establish laboratory colonies for further vectorial research. While, individual roles of the bacteria or fungi in paratransgenesis are warned for their possible utilization to frame the management strategy in upcoming works.}, }
@article {pmid36744754, year = {2023}, author = {Chen, J and Wang, MK and Xie, QX and Bing, XL and Li, TP and Hong, XY}, title = {NDUFA8 potentially rescues Wolbachia-induced cytoplasmic incompatibility in Laodelphax striatellus.}, journal = {Insect science}, volume = {}, number = {}, pages = {}, doi = {10.1111/1744-7917.13182}, pmid = {36744754}, issn = {1744-7917}, abstract = {The endosymbiont Wolbachia manipulates host reproduction by several strategies, one of the most important of which is cytoplasmic incompatibility (CI). CI can be rescued when Wolbachia-infected (WI) males mate with females infected with the same Wolbachia strain. However, the potential rescue mechanism of CI in the small brown planthopper Laodelphax striatellus is unclear. In this study, comparative transcriptome analysis was applied to explore the effect of Wolbachia on L. striatellus eggs. A total of 1387 differentially expressed genes were identified. RNAi of seven Wolbachia-upregulated key planthopper genes reduced egg reproduction, suggesting that Wolbachia might improve fecundity in L. striatellus by affecting these seven genes. Suppressing the expression of another upregulated gene, NDUFA8 (encoding NADH dehydrogenase [ubiquinone] 1 alpha subcomplex subunit 8-like) by RNAi significantly increased the mortality of early embryos without affecting the number of deposited eggs. Wolbachia infection upregulated the mRNA level of NDUFA8, and dsNDUFA8 treatment of WI females re-created CI-like symptoms, suggesting that NDUFA8 is associated with the rescue phenotype. Because all L. striatellus populations worldwide are infected with Wolbachia, NDUFA8 is a potential pest control target. This article is protected by copyright. All rights reserved.}, }
@article {pmid36743537, year = {2022}, author = {Mushtaq, S and Shafiq, M and Tariq, MR and Sami, A and Nawaz-Ul-Rehman, MS and Bhatti, MHT and Haider, MS and Sadiq, S and Abbas, MT and Hussain, M and Shahid, MA}, title = {Interaction between bacterial endophytes and host plants.}, journal = {Frontiers in plant science}, volume = {13}, number = {}, pages = {1092105}, pmid = {36743537}, issn = {1664-462X}, abstract = {Endophytic bacteria are mainly present in the plant's root systems. Endophytic bacteria improve plant health and are sometimes necessary to fight against adverse conditions. There is an increasing trend for the use of bacterial endophytes as bio-fertilizers. However, new challenges are also arising regarding the management of these newly discovered bacterial endophytes. Plant growth-promoting bacterial endophytes exist in a wide host range as part of their microbiome, and are proven to exhibit positive effects on plant growth. Endophytic bacterial communities within plant hosts are dynamic and affected by abiotic/biotic factors such as soil conditions, geographical distribution, climate, plant species, and plant-microbe interaction at a large scale. Therefore, there is a need to evaluate the mechanism of bacterial endophytes' interaction with plants under field conditions before their application. Bacterial endophytes have both beneficial and harmful impacts on plants but the exact mechanism of interaction is poorly understood. A basic approach to exploit the potential genetic elements involved in an endophytic lifestyle is to compare the genomes of rhizospheric plant growth-promoting bacteria with endophytic bacteria. In this mini-review, we will be focused to characterize the genetic diversity and dynamics of endophyte interaction in different host plants.}, }
@article {pmid36740932, year = {2023}, author = {Becher, H and Nichols, RA}, title = {Assembly-free quantification of vagrant DNA inserts.}, journal = {Molecular ecology resources}, volume = {}, number = {}, pages = {}, doi = {10.1111/1755-0998.13764}, pmid = {36740932}, issn = {1755-0998}, abstract = {Inserts of DNA from extranuclear sources, such as organelles and microbes, are common in eukaryote nuclear genomes. However, sequence similarity between the nuclear and extranuclear DNA, and a history of multiple insertions, make the assembly of these regions challenging. Consequently, the number, sequence, and location of these vagrant DNAs cannot be reliably inferred from the genome assemblies of most organisms. We introduce two statistical methods to estimate the abundance of nuclear inserts even in the absence of a nuclear genome assembly. The first (intercept method) only requires low-coverage (<1x) sequencing data, as commonly generated for population studies of organellar and ribosomal DNAs. The second method additionally requires that a subset of the individuals carry extra-nuclear DNA with diverged genotypes. We validated our intercept method using simulations and by re-estimating the frequency of human NUMTs (nuclear mitochondrial inserts). We then applied it to the grasshopper Podisma pedestris, exceptional for both its large genome size and reports of numerous NUMT inserts, estimating that NUMTs make up 0.056% of the nuclear genome, equivalent to >500 times the mitochondrial genome size. We also re-analysed a museomics dataset of the parrot Psephotellus varius, obtaining an estimate of only 0.0043%, in line with reports from other species of bird. Our study demonstrates the utility of low-coverage high-throughput sequencing data for the quantification of nuclear vagrant DNAs. Beyond quantifying organellar inserts, these methods could also be used on endosymbiont-derived sequences. We provide an R implementation of our methods called "vagrantDNA" and code to simulate test datasets.}, }
@article {pmid36735822, year = {2023}, author = {Sweet, AD and Browne, DR and Hernandez, AG and Johnson, KP and Cameron, SL}, title = {Draft genome assemblies of the avian louse Brueelia nebulosa and its associates using long-read sequencing from an individual specimen.}, journal = {G3 (Bethesda, Md.)}, volume = {}, number = {}, pages = {}, doi = {10.1093/g3journal/jkad030}, pmid = {36735822}, issn = {2160-1836}, abstract = {Sequencing high molecular weight (HMW) DNA with long-read and linked-read technologies has promoted a major increase in more complete genome sequences for non-model organisms. Sequencing approaches that rely on HMW DNA have been limited to larger organisms or pools of multiple individuals, but recent advances have allowed for sequencing from individuals of small-bodied organisms. Here, we use HMW DNA sequencing with PacBio long-reads and TELL-Seq linked-reads to assemble and annotate the genome from a single individual feather louse (Brueelia nebulosa) from a European Starling (Sturnus vulgaris). We assembled a genome with a relatively high scaffold N50 (637 kb) and with BUSCO scores (96.1%) comparable to louse genomes assembled from pooled individuals. We annotated a number of genes (10,938) similar to the human louse (Pediculus humanus) genome. Additionally, calling phased variants revealed that the Brueelia genome is more heterozygous (∼1%) then expected for a highly obligate and dispersal-limited parasite. We also assembled and annotated the mitochondrial genome and primary endosymbiont (Sodalis) genome from the individual louse, which showed evidence for heteroplasmy in the mitogenome and a reduced genome size in the endosymbiont compared to its free-living relative. Our study is a valuable demonstration of the capability to obtain high-quality genomes from individual small, non-model organisms. Applying this approach to other organisms could greatly increase our understanding of the diversity and evolution of individual genomes.}, }
@article {pmid36732111, year = {2023}, author = {Shaw, S and Roditi, I}, title = {The sweet and sour sides of trypanosome social motility.}, journal = {Trends in parasitology}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.pt.2023.01.001}, pmid = {36732111}, issn = {1471-5007}, abstract = {Recent studies showed that the formation of elegant geometric patterns by communities of Trypanosoma brucei on semi-solid surfaces, dubbed social motility (SoMo) by its discoverers, is a manifestation of pH taxis. This is caused by procyclic forms generating and responding to pH gradients through glucose metabolism and cAMP signalling. These findings established that trypanosomes can sense and manipulate gradients, potentially helping them to navigate through host tissues. At the same time, the host itself and bystanders such as endosymbionts have the potential to shape the environment and influence the chances of successful transmission. We postulate that the ability to sense and contribute to the gradient landscape may also underlie the tissue tropism and migration of other parasites in their hosts.}, }
@article {pmid36727281, year = {2023}, author = {Quach, QN and Clay, K and Lee, ST and Gardner, DR and Cook, D}, title = {Phylogenetic patterns of bioactive secondary metabolites produced by fungal endosymbionts in morning glories (Ipomoeeae, Convolvulaceae).}, journal = {The New phytologist}, volume = {}, number = {}, pages = {}, doi = {10.1111/nph.18785}, pmid = {36727281}, issn = {1469-8137}, abstract = {Heritable fungal endosymbiosis is under-investigated in plant biology and documented in only three plant families (Convolvulaceae, Fabaceae, Poaceae). An estimated 40% of morning glory species in the tribe Ipomoeeae (Convolvulaceae) have associations with one of two distinct heritable, endosymbiotic fungi (Periglandula and Chaetothyriales) that produce the bioactive metabolites ergot alkaloids, indole diterpene alkaloids, and swainsonine, which have been of interest for their toxic effects on animals and potential medical applications. Here, we report the occurrence of ergot alkaloids, indole diterpene alkaloids, and swainsonine in the Convolvulaceae; and the fungi that produce them based on synthesis of previous studies and new indole diterpene alkaloid data from 27 additional species in a phylogenetic, geographic, and life-history context. We find that individual morning glory species host no more than one metabolite-producing fungal endosymbiont (with one possible exception), possibly due to costs to the host and overlapping functions of the alkaloids. The symbiotic morning glory lineages occur in distinct phylogenetic clades and host species have significantly larger seed size than non-symbiotic species. The distinct and widely distributed endosymbiotic relationships in the morning glory family and their alkaloids provide an accessible study system for understanding heritable plant-fungal symbiosis evolution and their potential functions for host plants.}, }
@article {pmid36725749, year = {2023}, author = {Sullivan, TJ and Roberts, H and Bultman, TL}, title = {Genetic Covariation Between the Vertically Transmitted Endophyte Epichloë canadensis and Its Host Canada Wildrye.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {36725749}, issn = {1432-184X}, abstract = {Symbiotic mutualisms are thought to be stabilized by correlations between the interacting genotypes which may be strengthened via vertical transmission and/or reduced genetic variability within each species. Vertical transmission, however, may weaken interactions over time as the endosymbionts would acquire mutations that could not be purged. Additionally, temporal variation in a conditional mutualism could create genetic variation and increased variation in the interaction outcome. In this study, we assessed genetic variation in both members of a symbiosis, the endosymbiotic fungal endophyte Epichloë canadensis and its grass host Canada wildrye (Elymus canadensis). Both species exhibited comparable levels of diversity, mostly within populations rather than between. There were significant differences between populations, although not in the same pattern for the two species, and the differences were not correlated with geographic distance for either species. Interindividual genetic distance matrices for the two species were significantly correlated, although all combinations of discriminant analysis of principle components (DAPC) defined multilocus genotype groups were found suggesting that strict genotype matching is not necessary. Variation in interaction outcome is common in grass/endophyte interactions, and our results suggest that the accumulation of mutations overtime combined with temporal variation in selection pressures increasing genetic variation in the symbiosis may be the cause.}, }
@article {pmid36717919, year = {2023}, author = {Grandi, G and Chiappa, G and Ullman, K and Lindgren, PE and Olivieri, E and Sassera, D and Östlund, E and Omazic, A and Perissinotto, D and Söderlund, R}, title = {Characterization of the bacterial microbiome of Swedish ticks through 16S rRNA amplicon sequencing of whole ticks and of individual tick organs.}, journal = {Parasites &amp; vectors}, volume = {16}, number = {1}, pages = {39}, doi = {10.1186/s13071-022-05638-4}, pmid = {36717919}, issn = {1756-3305}, abstract = {BACKGROUND: The composition of the microbial flora associated with ixodid ticks has been studied in several species, revealing the importance of geographical origin, developmental stage(s) and feeding status of the tick, as well as substantial differences between tissues and organs. Studying the microbiome in the correct context and scale is therefore necessary for understanding the interactions between tick-borne pathogens and other microorganisms as well as other aspects of tick biology.<br><br>METHODS: In the present study the microbial flora of whole Ixodes ricinus, I. persulcatus and I. trianguliceps ticks were analyzed with 16S rRNA amplicon sequencing. Additionally, tick organs (midguts, Malpighian tubules, ovaries, salivary glands) from flat and engorged I. ricinus female ticks were examined with the same methodology.<br><br>RESULTS: The most abundant bacteria belonged to the group of Proteobacteria (Cand. Midichloria mitochondrii and Cand. Lariskella). 16S amplicon sequencing of dissected tick organs provided more information on the diversity of I. ricinus-associated microbial flora, especially when organs were collected from engorged ticks. Bacterial genera significantly associated with tick feeding status as well as genera associated with the presence of tick-borne pathogens were identified.<br><br>CONCLUSIONS: These results contribute to the knowledge of microbial flora associated with ixodid ticks in their northernmost distribution limit in Europe and opens new perspectives for other investigations on the function of these bacteria, including those using other approaches like in vitro cultivation and in vitro models.}, }
@article {pmid36715911, year = {2023}, author = {Nevalainen, LBM and Newton, ILG}, title = {Detection and Assessment of Wolbachia pipientis Infection.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2626}, number = {}, pages = {291-307}, pmid = {36715911}, issn = {1940-6029}, abstract = {Wolbachia pipientis is a widespread vertically transmitted intracellular bacterium naturally present in the model organism Drosophila melanogaster. As Wolbachia is present in a large number of Drosophila lines, it is critical for researchers to be able to identify which of their stocks maintain this infection to avoid any potential confounding variables. Here, we describe methods for detecting the bacterium and assessing the infection, including polymerase chain reaction (PCR) of DNA, multi-locus sequence typing (MLST) to identify strains, western blotting for protein detection, and immunohistochemistry and fluorescence in situ hybridization (FISH) of Drosophila ovaries to visually detect Wolbachia by fluorescence microscopy.}, }
@article {pmid36714835, year = {2022}, author = {Niehs, SP and Scherlach, K and Dose, B and Uzum, Z and Stinear, TP and Pidot, SJ and Hertweck, C}, title = {A highly conserved gene locus in endofungal bacteria codes for the biosynthesis of symbiosis-specific cyclopeptides.}, journal = {PNAS nexus}, volume = {1}, number = {4}, pages = {pgac152}, pmid = {36714835}, issn = {2752-6542}, abstract = {The tight association of the pathogenic fungus Rhizopus microsporus and its toxin-producing, bacterial endosymbionts (Mycetohabitans spp.) is distributed worldwide and has significance for agriculture, food production, and human health. Intriguingly, the endofungal bacteria are essential for the propagation of the fungal host. Yet, little is known about chemical mediators fostering the symbiosis, and universal metabolites that support the mutualistic relationship have remained elusive. Here, we describe the discovery of a complex of specialized metabolites produced by endofungal bacteria under symbiotic conditions. Through full genome sequencing and comparative genomics of eight endofungal symbiont strains from geographically distant regions, we discovered a conserved gene locus (hab) for a nonribosomal peptide synthetase as a unifying trait. Bioinformatics analyses, targeted gene deletions, and chemical profiling uncovered unprecedented depsipeptides (habitasporins) whose structures were fully elucidated. Computational network analysis and labeling experiments granted insight into the biosynthesis of their nonproteinogenic building blocks (pipecolic acid and β-phenylalanine). Deletion of the hab gene locus was shown to impair the ability of the bacteria to enter their fungal host. Our study unveils a common principle of the endosymbiotic lifestyle of Mycetohabitans species and expands the repertoire of characterized chemical mediators of a globally occurring mutualistic association.}, }
@article {pmid36714306, year = {2022}, author = {Barman, M and Samanta, S and Ahmed, B and Dey, S and Chakraborty, S and Deeksha, MG and Dutta, S and Samanta, A and Tarafdar, J and Roy, D}, title = {Transcription dynamics of heat-shock proteins (Hsps) and endosymbiont titres in response to thermal stress in whitefly, Bemisia tabaci (Asia-I).}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {1097459}, pmid = {36714306}, issn = {1664-042X}, abstract = {The sweet potato whitefly, Bemisia tabaci (Gennadius), is one of the several species complexes of whitefly that are currently significant agricultural pests. Bemisia tabaci infests more than 600 plant species and thrives under a wide range of temperature conditions. In addition to the direct damage caused by sucking plant sap, it vectors several plant viruses. Heat-shock proteins play a pivotal role in enabling the insect to extend its geographical location, survival, and reproduction under different stress conditions. B. tabaci harbours several endosymbionts under the genera Portiera, Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium, and Fritschea that directly or indirectly affect its fitness. By accelerating cuticle biosynthesis and sclerotisation, symbiotic microbes can reduce or enhance tolerance to extreme temperatures and detoxify heavy metals. Thus, symbionts or microbial communities can expand or constrain the abiotic niche space of their host and affect its ability to adapt to changing conditions. The present study delineates the effect of thermal stress on the expression of heat-shock genes and endosymbionts in B. tabaci. Studies of the expression level of heat-shock proteins with the help of quantitative real-time polymerase chain reaction (qRT-PCR) showed that heat- and cold-shock treatment fuels the increased expression of heat-shock proteins (Hsp40 and Hsp70). However, Hsp90 was not induced by a heat- and cold-shock treatment. A significant decrease in the relative titre of secondary endosymbionts, such as Rickettsia, Arsenophonus, and Wolbachia, were recorded in B. tabaci upon heat treatment. However, the titre of the primary symbiont, C. Portiera, was relatively unaffected by both cold and heat treatments. These results are indicative of the fact that Hsp genes and endosymbionts in B. tabaci are modulated in response to thermal stress, and this might be responsible for the adaptation of whitefly under changing climatic scenario.}, }
@article {pmid36703713, year = {2023}, author = {Quicray, M and Wilhelm, L and Enriquez, T and He, S and Scheifler, M and Visser, B}, title = {The Drosophila-parasitizing wasp Leptopilina heterotoma: A comprehensive model system in ecology and evolution.}, journal = {Ecology and evolution}, volume = {13}, number = {1}, pages = {e9625}, pmid = {36703713}, issn = {2045-7758}, abstract = {The parasitoid Leptopilina heterotoma has been used as a model system for more than 70 years, contributing greatly to diverse research areas in ecology and evolution. Here, we synthesized the large body of work on L. heterotoma with the aim to identify new research avenues that could be of interest also for researchers studying other parasitoids and insects. We start our review with a description of typical L. heterotoma characteristics, as well as that of the higher taxonomic groups to which this species belongs. We then continue discussing host suitability and immunity, foraging behaviors, as well as fat accumulation and life histories. We subsequently shift our focus towards parasitoid-parasitoid interactions, including L. heterotoma coexistence within the larger guild of Drosophila parasitoids, chemical communication, as well as mating and population structuring. We conclude our review by highlighting the assets of L. heterotoma as a model system, including its intermediate life history syndromes, the ease of observing and collecting natural hosts and wasps, as well as recent genomic advances.}, }
@article {pmid36699601, year = {2022}, author = {Kueneman, JG and Gillung, J and Van Dyke, MT and Fordyce, RF and Danforth, BN}, title = {Solitary bee larvae modify bacterial diversity of pollen provisions in the stem-nesting bee, Osmia cornifrons (Megachilidae).}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1057626}, pmid = {36699601}, issn = {1664-302X}, abstract = {Microbes, including diverse bacteria and fungi, play an important role in the health of both solitary and social bees. Among solitary bee species, in which larvae remain in a closed brood cell throughout development, experiments that modified or eliminated the brood cell microbiome through sterilization indicated that microbes contribute substantially to larval nutrition and are in some cases essential for larval development. To better understand how feeding larvae impact the microbial community of their pollen/nectar provisions, we examine the temporal shift in the bacterial community in the presence and absence of actively feeding larvae of the solitary, stem-nesting bee, Osmia cornifrons (Megachilidae). Our results indicate that the O. cornifrons brood cell bacterial community is initially diverse. However, larval solitary bees modify the microbial community of their pollen/nectar provisions over time by suppressing or eliminating rare taxa while favoring bacterial endosymbionts of insects and diverse plant pathogens, perhaps through improved conditions or competitive release. We suspect that the proliferation of opportunistic plant pathogens may improve nutrient availability of developing larvae through degradation of pollen. Thus, the health and development of solitary bees may be interconnected with pollen bacterial diversity and perhaps with the propagation of plant pathogens.}, }
@article {pmid36694551, year = {2023}, author = {de Gier, W}, title = {Phylomorphometrics reveal ecomorphological convergence in pea crab carapace shapes (Brachyura, Pinnotheridae).}, journal = {Ecology and evolution}, volume = {13}, number = {1}, pages = {e9744}, pmid = {36694551}, issn = {2045-7758}, abstract = {Most members of the speciose pea crab family (Decapoda: Brachyura: Pinnotheridae) are characterized by their symbioses with marine invertebrates in various host phyla. The ecology of pea crabs is, however, understudied, and the degree of host dependency of most species is still unclear. With the exception of one lineage of ectosymbiotic echinoid-associated crabs, species within the subfamily Pinnotherinae are endosymbionts, living within the body cavities of mollusks, ascidians, echinoderms, and brachiopods. By contrast, most members of the two other subfamilies are considered to have an ectosymbiotic lifestyle, sharing burrows and tubes with various types of worms and burrowing crustaceans (inquilism). The body shapes within the family are extremely variable, mainly in the width and length of the carapace. The variation of carapace shapes in the family, focusing on pinnotherines, is mapped using landmark-based morphometrics. Mean carapace shapes of species groups (based on their host preference) are statistically compared. In addition, a phylomorphometric approach is used to study three different convergence events (across subfamilies; between three genera; and within one genus), and link these events with the associated hosts.}, }
@article {pmid36691279, year = {2023}, author = {Cooper, W and Swisher Grimm, K and Angelella, G and Mustafa, T}, title = {Acquisition and transmission of "Candidatus Liberibacter solanacearum" differs among Wolbachia-infected and -uninfected haplotypes of Bactericera cockerelli.}, journal = {Plant disease}, volume = {}, number = {}, pages = {}, doi = {10.1094/PDIS-11-22-2701-RE}, pmid = {36691279}, issn = {0191-2917}, abstract = {"Candidatus Liberibacter solanacearum" (Lso) causes disease symptoms and economic losses in potato, tomato, and other solanaceous crops in North America. Lso is transmitted to plants by potato psyllid, Bactericera cockerelli, which occurs as distinct haplotypes named western, central, and northwestern that differ in presence or absence of the bacterial endosymbiont, Wolbachia. Previous work showed that all three vector haplotypes can transmit Lso, but it was not clear whether acquisition and transmission rates of Lso were equal among the haplotypes. The goal of our study was to compare Lso infection rates among psyllids of the western, central, and northwestern haplotypes. Using data collected from several years of periodic testing of Lso infection of laboratory-reared potato psyllid colonies, we showed that psyllids of the western and central haplotypes are more likely to harbor Lso than are psyllids of the northwestern haplotype. We then used greenhouse assays to demonstrate that psyllids of the northwestern haplotype are less likely to acquire and transmit Lso compared with those of the western haplotype. Lso infection rates corresponded with Wolbachia infection among the three psyllid haplotypes. The Wolbachia-infected central and western haplotypes were more likely to harbor and transmit Lso compared with the Wolbachia-free northwestern haplotype. Results demonstrate that potato psyllids of the western and central haplotypes pose a greater risk for spread of Lso in crops and suggest a pattern between infection with Lso and Wolbachia in potato psyllid.}, }
@article {pmid36689552, year = {2023}, author = {Vancaester, E and Blaxter, M}, title = {Phylogenomic analysis of Wolbachia genomes from the Darwin Tree of Life biodiversity genomics project.}, journal = {PLoS biology}, volume = {21}, number = {1}, pages = {e3001972}, doi = {10.1371/journal.pbio.3001972}, pmid = {36689552}, issn = {1545-7885}, abstract = {The Darwin Tree of Life (DToL) project aims to sequence all described terrestrial and aquatic eukaryotic species found in Britain and Ireland. Reference genome sequences are generated from single individuals for each target species. In addition to the target genome, sequenced samples often contain genetic material from microbiomes, endosymbionts, parasites, and other cobionts. Wolbachia endosymbiotic bacteria are found in a diversity of terrestrial arthropods and nematodes, with supergroups A and B the most common in insects. We identified and assembled 110 complete Wolbachia genomes from 93 host species spanning 92 families by filtering data from 368 insect species generated by the DToL project. From 15 infected species, we assembled more than one Wolbachia genome, including cases where individuals carried simultaneous supergroup A and B infections. Different insect orders had distinct patterns of infection, with Lepidopteran hosts mostly infected with supergroup B, while infections in Diptera and Hymenoptera were dominated by A-type Wolbachia. Other than these large-scale order-level associations, host and Wolbachia phylogenies revealed no (or very limited) cophylogeny. This points to the occurrence of frequent host switching events, including between insect orders, in the evolutionary history of the Wolbachia pandemic. While supergroup A and B genomes had distinct GC% and GC skew, and B genomes had a larger core gene set and tended to be longer, it was the abundance of copies of bacteriophage WO who was a strong determinant of Wolbachia genome size. Mining raw genome data generated for reference genome assemblies is a robust way of identifying and analysing cobiont genomes and giving greater ecological context for their hosts.}, }
@article {pmid36686690, year = {2022}, author = {Büttiker, P and Weissenberger, S and Esch, T and Anders, M and Raboch, J and Ptacek, R and Kream, RM and Stefano, GB}, title = {Dysfunctional mitochondrial processes contribute to energy perturbations in the brain and neuropsychiatric symptoms.}, journal = {Frontiers in pharmacology}, volume = {13}, number = {}, pages = {1095923}, pmid = {36686690}, issn = {1663-9812}, abstract = {Mitochondria are complex endosymbionts that evolved from primordial purple nonsulfur bacteria. The incorporation of bacteria-derived mitochondria facilitates a more efficient and effective production of energy than what could be achieved based on previous processes alone. In this case, endosymbiosis has resulted in the seamless coupling of cytochrome c oxidase and F-ATPase to maximize energy production. However, this mechanism also results in the generation of reactive oxygen species (ROS), a phenomenon that can have both positive and negative ramifications on the host. Recent studies have revealed that neuropsychiatric disorders have a pro-inflammatory component in which ROS is capable of initiating damage and cognitive malfunction. Our current understanding of cognition suggests that it is the product of a neuronal network that consumes a substantial amount of energy. Thus, alterations or perturbations of mitochondrial function may alter not only brain energy supply and metabolite generation, but also thought processes and behavior. Mitochondrial abnormalities and oxidative stress have been implicated in several well-known psychiatric disorders, including schizophrenia (SCZ) and bipolar disorder (BPD). As cognition is highly energy-dependent, we propose that the neuronal pathways underlying maladaptive cognitive processing and psychiatric symptoms are most likely dependent on mitochondrial function, and thus involve brain energy translocation and the accumulation of the byproducts of oxidative stress. We also hypothesize that neuropsychiatric symptoms (e.g., disrupted emotional processing) may represent the vestiges of an ancient masked evolutionary response that can be used by both hosts and pathogens to promote self-repair and proliferation via parasitic and/or symbiotic pathways.}, }
@article {pmid36683703, year = {2022}, author = {Liu, Y and He, ZQ and Wen, Q and Peng, J and Zhou, YT and Mandour, N and McKenzie, CL and Ahmed, MZ and Qiu, BL}, title = {Parasitoid-mediated horizontal transmission of Rickettsia between whiteflies.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {1077494}, pmid = {36683703}, issn = {2235-2988}, abstract = {Intracellular bacterial endosymbionts of arthropods are mainly transmitted vertically from mother to offspring, but phylogenetically distant insect hosts often harbor identical endosymbionts, indicating that horizontal transmission from one species to another occurs in nature. Here, we investigated the parasitoid Encarsia formosa-mediated horizontal transmission of the endosymbiont Rickettsia between different populations of whitefly Bemisia tabaci MEAM1. Rickettsia was successfully transmitted from the positive MEAM1 nymphs (R [+]) into E. formosa and retained at least for 48 h in E. formosa adults. Fluorescence in situ hybridization (FISH) visualization results revealed that the ovipositors, mouthparts, and digestive tract of parasitoid adults get contaminated with Rickettsia. Random non-lethal probing of Rickettisia-negative (R[-]) MEAM1 nymphs by these Rickettsia-carrying E. formosa resulted in newly infected MEAM1 nymphs, and the vertical transmission of Rickettsia within the recipient females can remain at least up to F3 generation. Further phylogenetic analyses revealed that Rickettsia had high fidelity during the horizontal transmission in whiteflies and parasitoids. Our findings may help to explain why Rickettsia bacteria are so abundant in arthropods and suggest that, in some insect species that shared the same parasitoids, Rickettsia may be maintained in populations by horizontal transmission.}, }
@article {pmid36677450, year = {2023}, author = {Hoffman, T and Olsen, B and Lundkvist, &#xc5;}, title = {The Biological and Ecological Features of Northbound Migratory Birds, Ticks, and Tick-Borne Microorganisms in the African-Western Palearctic.}, journal = {Microorganisms}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/microorganisms11010158}, pmid = {36677450}, issn = {2076-2607}, abstract = {Identifying the species that act as hosts, vectors, and vehicles of vector-borne pathogens is vital for revealing the transmission cycles, dispersal mechanisms, and establishment of vector-borne pathogens in nature. Ticks are common vectors for pathogens causing human and animal diseases, and they transmit a greater variety of pathogenic agents than any other arthropod vector group. Ticks depend on the movements by their vertebrate hosts for their dispersal, and tick species with long feeding periods are more likely to be transported over long distances. Wild birds are commonly parasitized by ticks, and their migration patterns enable the long-distance range expansion of ticks. The African-Palearctic migration system is one of the world's largest migrations systems. African-Western Palearctic birds create natural links between the African, European, and Asian continents when they migrate biannually between breeding grounds in the Palearctic and wintering grounds in Africa and thereby connect different biomes. Climate is an important geographical determinant of ticks, and with global warming, the distribution range and abundance of ticks in the Western Palearctic may increase. The introduction of exotic ticks and their microorganisms into the Western Palearctic via avian vehicles might therefore pose a greater risk for the public and animal health in the future.}, }
@article {pmid36677447, year = {2023}, author = {Fujishima, M and Kawano, H and Miyakawa, I}, title = {A 63-kDa Periplasmic Protein of the Endonuclear Symbiotic Bacterium Holospora obtusa Secreted to the Outside of the Bacterium during the Early Infection Process Binds Weakly to the Macronuclear DNA of the Host Paramecium caudatum.}, journal = {Microorganisms}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/microorganisms11010155}, pmid = {36677447}, issn = {2076-2607}, abstract = {The Gram-negative bacterium Holospora obtusa is a macronucleus-specific symbiont of the ciliate Paramecium caudatum. It is known that an infection of this bacterium induces high level expressions of the host hsp60 and hsp70 genes, and the host cell acquires both heat-shock and high salt resistances. In addition, an infectious form of H. obtusa-specific 63-kDa periplasmic protein with a DNA-binding domain in its amino acid sequence is secreted into the host macronucleus after invasion into the macronucleus and remain within the nucleus. These facts suggest that binding of the 63-kDa protein to the host macronuclear DNA causes changes in the host gene expressions and enhances an environmental adaptability of the host cells. This 63-kDa protein was renamed as periplasmic region protein 1 (PRP1) to distinguish it from other proteins with similar molecular weights. To confirm whether PRP1 indeed binds to the host DNA, SDS-DNA PAGE and DNA affinity chromatography with calf thymus DNA and P. caudatum DNA were conducted and confirmed that PRP1 binds weakly to the P. caudatum DNA with a monoclonal antibody raised for the 63-kDa protein.}, }
@article {pmid36675947, year = {2023}, author = {Thimmappa, BC and Salhi, LN and Forget, L and Sarrasin, M and Bustamante Villalobos, P and Lang, BF and Burger, G}, title = {Nuclear Genome Sequence and Gene Expression of an Intracellular Fungal Endophyte Stimulating the Growth of Cranberry Plants.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, doi = {10.3390/jof9010126}, pmid = {36675947}, issn = {2309-608X}, abstract = {Ericaceae thrive in poor soil, which we postulate is facilitated by microbes living inside those plants. Here, we investigate the growth stimulation of the American cranberry (Vaccinium macrocarpon) by one of its fungal endosymbionts, EC4. We show that the symbiont resides inside the epidermal root cells of the host but extends into the rhizosphere via its hyphae. Morphological classification of this fungus is ambiguous, but phylogenetic inference based on 28S rRNA identifies EC4 as a Codinaeella species (Chaetosphaeriaceae, Sordariomycetes, Ascomycetes). We sequenced the genome and transcriptome of EC4, providing the first 'Omics' information of a Chaetosphaeriaceae fungus. The 55.3-Mbp nuclear genome contains 17,582 potential protein-coding genes, of which nearly 500 have the capacity to promote plant growth. For comparing gene sets involved in biofertilization, we annotated the published genome assembly of the plant-growth-promoting Trichoderma hamatum. The number of proteins involved in phosphate transport and solubilization is similar in the two fungi. In contrast, EC4 has ~50% more genes associated with ammonium, nitrate/nitrite transport, and phytohormone synthesis. The expression of 36 presumed plant-growth-promoting EC4 genes is stimulated when the fungus is in contact with the plant. Thus, Omics and in-plantae tests make EC4 a promising candidate for cranberry biofertilization on nutrient-poor soils.}, }
@article {pmid36675893, year = {2023}, author = {Akram, S and Ahmed, A and He, P and He, P and Liu, Y and Wu, Y and Munir, S and He, Y}, title = {Uniting the Role of Endophytic Fungi against Plant Pathogens and Their Interaction.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, doi = {10.3390/jof9010072}, pmid = {36675893}, issn = {2309-608X}, abstract = {Endophytic fungi are used as the most common microbial biological control agents (MBCAs) against phytopathogens and are ubiquitous in all plant parts. Most of the fungal species have roles against a variety of plant pathogens. Fungal endophytes provide different services to be used as pathogen control agents, using an important aspect in the form of enhanced plant growth and induced systemic resistance, produce a variety of antifungal secondary metabolites (lipopeptides, antibiotics and enzymes) through colonization, and compete with other pathogenic microorganisms for growth factors (space and nutrients). The purpose of this review is to highlight the biological control potential of fungal species with antifungal properties against different fungal plant pathogens. We focused on the introduction, biology, isolation, identification of endophytic fungi, and their antifungal activity against fungal plant pathogens. The endosymbionts have developed specific genes that exhibited endophytic behavior and demonstrated defensive responses against pathogens such as antibiosis, parasitism, lytic enzyme and competition, siderophore production, and indirect responses by induced systemic resistance (ISR) in the host plant. Finally, different microscopic detection techniques to study microbial interactions (endophytic and pathogenic fungal interactions) in host plants are briefly discussed.}, }
@article {pmid36675187, year = {2023}, author = {Deng, Y and Wang, K and Hu, Z and Hu, Q and Tang, Y}, title = {Different Geographic Strains of Dinoflagellate Karlodinium veneficum Host Highly Diverse Fungal Community and Potentially Serve as Possible Niche for Colonization of Fungal Endophytes.}, journal = {International journal of molecular sciences}, volume = {24}, number = {2}, pages = {}, doi = {10.3390/ijms24021672}, pmid = {36675187}, issn = {1422-0067}, abstract = {In numerous studies, researchers have explored the interactions between fungi and their hosting biota in terrestrial systems, while much less attention has been paid to the counterpart interactions in aquatic, and particularly marine, ecosystems. Despite the growing recognition of the potential functions of fungi in structuring phytoplankton communities, the current insights were mostly derived from phytoplankton hosts, such as diatoms, green microalgae, and cyanobacteria. Dinoflagellates are the second most abundant group of phytoplankton in coastal marine ecosystems, and they are notorious for causing harmful algal blooms (HABs). In this study, we used high-throughput amplicon sequencing to capture global snapshots of specific fungal assemblages associated with laboratory-cultured marine dinoflagellate. We investigated a total of 13 clonal cultures of the dinoflagellate Karlodinium veneficum that were previously isolated from 5 geographic origins and have been maintained in our laboratory from several months to more than 14 years. The total recovered fungal microbiome, which consisted of 349 ASVs (amplicon sequencing variants, sequences clustered at a 100% sequence identity), could be assigned to 4 phyla, 18 classes, 37 orders, 65 families, 97 genera, and 131 species. The fungal consortium displayed high diversity and was dominated by filamentous fungi and ascomycetous and basidiomycetous yeasts. A core set of three genera among all the detected fungi was constitutively present in the K. veneficum strains isolated from geographically distant regions, with the top two most abundant genera, Thyridium and Pseudeurotium, capable of using hydrocarbons as the sole or major source of carbon and energy. In addition, fungal taxa previously documented as endophytes in other hosts were also found in all tested strains of K. veneficum. Because host-endophyte interactions are highly variable and strongly case-dependent, these fungal taxa were not necessarily genuine endosymbionts of K. veneficum; instead, it raised the possibility that dinoflagellates could potentially serve as an alternative ecological niche for the colonization of fungal endophytes. Our findings lay the foundation for further investigations into the potential roles or functions of fungi in the regulation of the growth dynamics and HABs of marine dinoflagellates in the field.}, }
@article {pmid36674613, year = {2023}, author = {Wiesinger, A and Wenderlein, J and Ulrich, S and Hiereth, S and Chitimia-Dobler, L and Straubinger, RK}, title = {Revealing the Tick Microbiome: Insights into Midgut and Salivary Gland Microbiota of Female Ixodes ricinus Ticks.}, journal = {International journal of molecular sciences}, volume = {24}, number = {2}, pages = {}, doi = {10.3390/ijms24021100}, pmid = {36674613}, issn = {1422-0067}, abstract = {The ectoparasite Ixodes ricinus is an important vector for many tick-borne diseases (TBD) in the northern hemisphere, such as Lyme borreliosis, rickettsiosis, human granulocytic anaplasmosis, or tick-borne encephalitis virus. As climate change will lead to rising temperatures in the next years, we expect an increase in tick activity, tick population, and thus in the spread of TBD. Consequently, it has never been more critical to understand relationships within the microbial communities in ticks that might contribute to the tick's fitness and the occurrence of TBD. Therefore, we analyzed the microbiota in different tick tissues such as midgut, salivary glands, and residual tick material, as well as the microbiota in complete Ixodes ricinus ticks using 16S rRNA gene amplicon sequencing. By using a newly developed DNA extraction protocol for tick tissue samples and a self-designed mock community, we were able to detect endosymbionts and pathogens that have been described in the literature previously. Further, this study displayed the usefulness of including a mock community during bioinformatic analysis to identify essential bacteria within the tick.}, }
@article {pmid36670832, year = {2023}, author = {Silva, RXG and Madeira, D and Cartaxana, P and Calado, R}, title = {Assessing the Trophic Impact of Bleaching: The Model Pair Berghia stephanieae/Exaiptasia diaphana.}, journal = {Animals : an open access journal from MDPI}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/ani13020291}, pmid = {36670832}, issn = {2076-2615}, abstract = {Bleaching events associated with climate change are increasing worldwide, being a major threat to tropical coral reefs. Nonetheless, the indirect impacts promoted by the bleaching of organisms hosting photosynthetic endosymbionts, such as those impacting trophic interactions, have received considerably less attention by the scientific community. Bleaching significantly affects the nutritional quality of bleached organisms. The consequences promoted by such shifts remain largely overlooked, namely on specialized predators that have evolved to prey upon organisms hosting photosynthetic endosymbionts and benefit nutritionally, either directly or indirectly, from the available pool of photosynthates. In the present study, we advocate the use of the model predator-prey pair featuring the stenophagous nudibranch sea slug Berghia stephanieae that preys upon the photosymbiotic glass anemone Exaiptasia diaphana to study the impacts of bleaching on trophic interactions. These model organisms are already used in other research fields, and one may benefit from knowledge available on their physiology, omics, and culture protocols under controlled laboratory conditions. Moreover, B. stephanieae can thrive on either photosymbiotic or aposymbiotic (bleached) glass anemones, which can be easily maintained over long periods in the laboratory (unlike photosymbiotic corals). As such, one can investigate if and how nutritional shifts induced by bleaching impact highly specialized predators (stenophagous species), as well as if and how such effects cascade over consecutive generations. Overall, by using this model predator-prey pair one can start to truly unravel the trophic effects of bleaching events impacting coral reef communities, as well as their prevalence over time.}, }
@article {pmid36670494, year = {2023}, author = {Chamankar, B and Maleki-Ravasan, N and Karami, M and Forouzan, E and Karimian, F and Naeimi, S and Choobdar, N}, title = {The structure and diversity of microbial communities in Paederus fuscipes (Coleoptera: Staphylinidae): from ecological paradigm to pathobiome.}, journal = {Microbiome}, volume = {11}, number = {1}, pages = {11}, pmid = {36670494}, issn = {2049-2618}, abstract = {BACKGROUND: Paederus fuscipes is medically the most famous rove beetle, which causes dermatitis or conjunctivitis in humans, as well as gastrointestinal toxicosis in livestock, via releasing toxic hemolymph containing pederin. Pedrin biosynthesis genes have been identified in uncultured Pseudomonas-like endosymbionts that are speculated to be acquired through a horizontal transfer. However, the composition of the P. fuscipes microbial community, especially of the gut and genital microbiome, remains unclear. This study was aimed to characterize the structure and diversity of P. fuscipes-associated bacterial communities in terms of gender, organ, and location using the Illumina HiSeq platform in the southern littorals of Caspian Sea.<br><br>RESULTS: The OTUs identified from P. fuscipes specimens were collapsed into 40 phyla, 112 classes, 249 orders, 365 families, 576 genera, and 106 species. The most abundant families were Pseudomonadaceae, Spiroplasmataceae, Weeksellaceae, Enterococcaceae, and Rhizobiaceae, respectively. Thirty top genera made up > 94% of the P. fuscipes microbiome, with predominating Pseudomonas, followed by the Spiroplasma, Apibacter, Enterococcus, Dysgonomonas, Sebaldella, Ruminococcus, and Wolbachia. Interesting dissimilarities were also discovered within and between the beetle microbiomes in terms of genders and organs. Analyses showed that Spiroplasma / Apibacter as well as Pseudomonas / Pseudomonas were the most abundant in the genitals / intestines of male and female beetles, respectively. Bacterial richness did not display any significant difference in the three provinces but was higher in male beetles than in females and more in the genitals than intestines.<br><br>CONCLUSIONS: The present study identified Pseudomonas-like endobacterium as a common symbiont of P. fuscipes beetles; this bacterium begins its journey from gut and genitalia of females to reach the male rove beetles. Additionally, male and female rove beetles were characterized by distinctive microbiota in different organs, likely reflecting different functions and/or adaptation processes. Evidence of the extension of P. fuscipes microbiome from the environmental paradigm to the pathobiome was also presented herein. A comprehensive survey of P. fuscipes microbiome components may eventually lead to ecological insights into the production and utilization of defensive compound of pederin and also the management of linear dermatitis with the use of available antibiotics against bacterial pathogens released by the beetles. Video Abstract.}, }
@article {pmid36669676, year = {2023}, author = {Awad, M and Piálková, R and Haelewaters, D and Nedvěd, O}, title = {Infection patterns of Harmonia axyridis (Coleoptera: Coccinellidae) by ectoparasitic microfungi and endosymbiotic bacteria.}, journal = {Journal of invertebrate pathology}, volume = {}, number = {}, pages = {107887}, doi = {10.1016/j.jip.2023.107887}, pmid = {36669676}, issn = {1096-0805}, abstract = {The invasive alien ladybird Harmonia axyridis (Coleoptera: Coccinellidae) hosts a wide range of natural enemies. Many observations have been done in nature but experimental studies of interactions of multiple enemies on Ha. axyridis are rare. In light of this knowledge gap, we tested whether the host phenotype and presence of bacterial endosymbionts Spiroplasma and Wolbachia affected parasitism of Ha. axyridis by the ectoparasitic fungus Hesperomyces harmoniae (Ascomycota: Laboulbeniales). We collected 379 Ha. axyridis in the Czech Republic, processed specimens, including screening for He. harmoniae and a molecular assessment for bacteria, and calculated fecundity and hatchability of females. We found that high hatchability rate (71%) was conditioned by high fecundity (20 eggs daily or more). The average parasite prevalence of He. harmoniae was 53%, while the infection rate of Spiroplasma was 73% in ladybirds that survived in winter conditions. Wolbachia was only present in 2% of the analyzed ladybirds. Infection by either He. harmoniae or Spiroplasma did not differ among host color morphs. In the novemdecimsignata morph, younger individuals (with orange elytra) were more heavily parasitized compared to old ones (with red elytra). Fecundity and hatchability rate of females were unaffected by infection with either He. harmoniae or Spiroplasma. However, female ladybirds co-infected with He. harmoniae and Spiroplasma had a significantly lower fecundity and hatchability compared to females with only one or no symbiont.}, }
@article {pmid36653630, year = {2023}, author = {Mayfield, AB}, title = {Multi-macromolecular Extraction from Endosymbiotic Anthozoans.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2625}, number = {}, pages = {17-56}, pmid = {36653630}, issn = {1940-6029}, abstract = {Obligately symbiotic associations between reef-building corals (anthozoan cnidarians) and photosynthetically active dinoflagellates of the family Symbiodiniaceae comprise the functional basis of all coral reef ecosystems. Given the existential threats of global climate change toward these thermo-sensitive entities, there is an urgent need to better understand the physiological implications of changes in the abiotic milieu of scleractinian corals and their mutualistic algal endosymbionts. Although initially slow to leverage the immense breakthroughs in molecular biotechnology that have benefited humankind, coral biologists are making up for lost time in exploiting an array of ever-advancing molecular tools for answering key questions pertaining to the survival of corals in an ever-changing world. In order to comprehensively characterize the multi-omic landscape of the coral holobiont-the cnidarian host, its intracellular dinoflagellates, and a plethora of other microbial constituents-I introduce a series of protocols herein that yield large quantities of high-quality RNA, DNA, protein, lipids, and polar metabolites from a diverse array of reef corals and endosymbiotic sea anemones. Although numerous published articles in the invertebrate zoology field feature protocols that lead to sufficiently high yield of intact host coral macromolecules, through using the approach outlined herein one may simultaneously acquire a rich, multi-compartmental biochemical pool that truly reflects the complex and dynamic nature of these animal-plant chimeras.}, }
@article {pmid36653505, year = {2023}, author = {Prada, F and Franzellitti, S and Caroselli, E and Cohen, I and Marini, M and Campanelli, A and Sana, L and Mancuso, A and Marchini, C and Puglisi, A and Candela, M and Mass, T and Tassi, F and LaJeunesse, TC and Dubinsky, Z and Falini, G and Goffredo, S}, title = {Acclimatization of a coral-dinoflagellate mutualism at a CO2 vent.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {66}, pmid = {36653505}, issn = {2399-3642}, abstract = {Ocean acidification caused by shifts in ocean carbonate chemistry resulting from increased atmospheric CO2 concentrations is threatening many calcifying organisms, including corals. Here we assessed autotrophy vs heterotrophy shifts in the Mediterranean zooxanthellate scleractinian coral Balanophyllia europaea acclimatized to low pH/high pCO2 conditions at a CO2 vent off Panarea Island (Italy). Dinoflagellate endosymbiont densities were higher at lowest pH Sites where changes in the distribution of distinct haplotypes of a host-specific symbiont species, Philozoon balanophyllum, were observed. An increase in symbiont C/N ratios was observed at low pH, likely as a result of increased C fixation by higher symbiont cell densities. δ[13]C values of the symbionts and host tissue reached similar values at the lowest pH Site, suggesting an increased influence of autotrophy with increasing acidification. Host tissue δ[15]N values of 0‰ strongly suggest that diazotroph N2 fixation is occurring within the coral tissue/mucus at the low pH Sites, likely explaining the decrease in host tissue C/N ratios with acidification. Overall, our findings show an acclimatization of this coral-dinoflagellate mutualism through trophic adjustment and symbiont haplotype differences with increasing acidification, highlighting that some corals are capable of acclimatizing to ocean acidification predicted under end-of-century scenarios.}, }
@article {pmid36651852, year = {2023}, author = {Takagi, T and Aoyama, K and Motone, K and Aburaya, S and Yamashiro, H and Miura, N and Inoue, K}, title = {Mutualistic Interactions between Dinoflagellates and Pigmented Bacteria Mitigate Environmental Stress.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0246422}, doi = {10.1128/spectrum.02464-22}, pmid = {36651852}, issn = {2165-0497}, abstract = {Scleractinian corals form symbiotic relationships with a variety of microorganisms, including endosymbiotic dinoflagellates of the family Symbiodiniaceae, and with bacteria, which are collectively termed coral holobionts. Interactions between hosts and their symbionts are critical to the physiological status of corals. Coral-microorganism interactions have been studied extensively, but dinoflagellate-bacterial interactions remain largely unexplored. Here, we developed a microbiome manipulation method employing KAS-antibiotic treatment (kanamycin, ampicillin, and streptomycin) to favor pigmented bacteria residing on cultured Cladocopium and Durusdinium, major endosymbionts of corals, and isolated several carotenoid-producing bacteria from cell surfaces of the microalgae. Following KAS-antibiotic treatment of Cladocopium sp. strain NIES-4077, pigmented bacteria increased 8-fold based on colony-forming assays from the parental strain, and 100% of bacterial sequences retrieved through 16S rRNA amplicon sequencing were affiliated with the genus Maribacter. Microbiome manipulation enabled host microalgae to maintain higher maximum quantum yield of photosystem II (variable fluorescence divided by maximum fluorescence [Fv/Fm]) under light-stress conditions, compared to the parental strain. Furthermore, by combining culture-dependent and -independent techniques, we demonstrated that species of the family Symbiodiniaceae and pigmented bacteria form strong interactions. Dinoflagellates protected bacteria from antibiotics, while pigmented bacteria protected microalgal cells from light stress via carotenoid production. Here, we describe for the first time a symbiotic relationship in which dinoflagellates and bacteria mutually reduce environmental stress. Investigations of microalgal-bacterial interactions further document bacterial contributions to coral holobionts and may facilitate development of novel techniques for microbiome-mediated coral reef conservation. IMPORTANCE Coral reefs cover less than 0.1% of the ocean floor, but about 25% of all marine species depend on coral reefs at some point in their life cycles. However, rising ocean temperatures associated with global climate change are a serious threat to coral reefs, causing dysfunction of the photosynthetic apparatus of endosymbiotic microalgae of corals, and overproducing reactive oxygen species harmful to corals. We manipulated the microbiome using an antibiotic treatment to favor pigmented bacteria, enabling their symbiotic microalgal partners to maintain higher photosynthetic function under insolation stress. Furthermore, we investigated mechanisms underlying microalgal-bacterial interactions, describing for the first time a symbiotic relationship in which the two symbionts mutually reduce environmental stress. Our findings extend current insights about microalgal-bacterial interactions, enabling better understanding of bacterial contributions to coral holobionts under stressful conditions and offering hope of reducing the adverse impacts of global warming on coral reefs.}, }
@article {pmid36651455, year = {2023}, author = {Mata-Somarribas, C and Quesada-López, J and Matamoros, MF and Cervantes-Gómez, C and Mejía, A and Chacón, K and Bendig, I and Campos, R and Quesada-Morera, R and Cantanhêde, LM and Pereira, LOR and Cupolillo, E}, title = {Raising the suspicion of a non-autochthonous infection: identification of Leishmania guyanensis from Costa Rica exhibits a Leishmaniavirus related to Brazilian north-east and French Guiana viral genotypes.}, journal = {Memorias do Instituto Oswaldo Cruz}, volume = {117}, number = {}, pages = {e220162}, doi = {10.1590/0074-02760220162}, pmid = {36651455}, issn = {1678-8060}, abstract = {BACKGROUND: Costa Rica has a history of neglecting prevention, control and research of leishmaniasis, including limited understanding on Leishmania species causing human disease across the country and a complete lack of knowledge on the Leishmania RNA virus, described as a factor linked to the worsening and metastasis of leishmanial lesions.<br><br>OBJECTIVES: The aim of this work was to describe a case of cutaneous leishmaniasis by Leishmania (Viannia) guyanensis, bearing infection with Leishmaniavirus 1 (LRV1) in Costa Rica, raising the suspicion of imported parasites in the region.<br><br>METHODS: The Leishmania strain was previously identified by routine hsp70 polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in Costa Rica and subsequently characterised by isoenzyme electrophoresis and Sanger sequencing in Brazil. Screening for LRV1 was conducted with a dual RT-PCR approach and sequencing of the fragment obtained.<br><br>FINDINGS: Since 2016 Costa Rica performs Leishmania isolation and typing as part of its epidemiological surveillance activities. Amongst 113 strains typed until 2019, only one was characterised as a L. (V.) guyanensis, corresponding to the first confirmed report of this species in the country. Interestingly, the same strain tested positive for LRV1. Sequencing of the viral orf1 and 2, clustered this sample with other LRV1 genotypes of South American origin, from the Northeast of Brazil and French Guiana.<br><br>MAIN CONCLUSION: The unique characteristics of this finding raised the suspicion that it was not an autochthonous strain. Notwithstanding its presumed origin, this report points to the occurrence of said endosymbiont in Central American Leishmania strains. The possibility of its local dispersion represents one more challenge faced by regional health authorities in preventing and controlling leishmaniasis.}, }
@article {pmid36646785, year = {2023}, author = {Sétamou, M and Soto, YL and Tachin, M and Alabi, OJ}, title = {Report on the first detection of Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) in the Republic of Benin, West Africa.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {801}, pmid = {36646785}, issn = {2045-2322}, abstract = {The Asian citrus psyllid (ACP), Diaphorina citri, was detected for the first time in the Republic of Benin, West Africa. The ACP is a known vector of Candidatus Liberibacter asiaticus (CLas), the putative causal agent of the devastating Huanglongbing (HLB; citrus greening disease). During visual surveys, ACP was only observed on residential citrus trees in southern Benin, but not in residential areas or commercial groves in the central and northern parts of the country. Its identity was confirmed morphologically and molecularly via DNA barcoding with published primers. Analysis of the obtained sequences showed that the ACP recorded in Benin clustered with the ones previously reported from Nigeria, suggesting a common origin of both populations. The ACP samples from Benin also carried Ca. Carsonella ruddii and Ca. Profftella armatura, two commonly found ACP endosymbionts. However, all the sampled ACP individuals tested negative for Ca. Liberibacter africanus, Ca. Liberibacter americanus, and CLas by quantitative polymerase chain reaction. This is the second report of the ACP in West Africa after Nigeria, the eastern bordering country of the Republic of Benin. Benin has an expanding commercial citrus industry, especially in the southern part of the country. Although the ACP samples tested negative for the HLB associated bacteria, the detection of ACP in the country requires swift actions including area-wide surveys to determine the extent of spread of this pest and the implementation of eradication or control efforts to prevent its establishment and spread of HLB in the country.}, }
@article {pmid36636344, year = {2023}, author = {Hussain, M and Zhang, G and Leitner, M and Hedges, LM and Asgari, S}, title = {Wolbachia RNase HI contributes to virus blocking in the mosquito Aedes aegypti.}, journal = {iScience}, volume = {26}, number = {1}, pages = {105836}, pmid = {36636344}, issn = {2589-0042}, abstract = {The endosymbiotic bacterium Wolbachia pipientis blocks replication of several arboviruses in transinfected Aedes aegypti mosquitoes. However, the mechanism of virus blocking remains poorly understood. Here, we characterized an RNase HI gene from Wolbachia, which is rapidly induced in response to dengue virus (DENV) infection. Knocking down w RNase HI using antisense RNA in Wolbachia-transinfected mosquito cell lines and A. aegypti mosquitoes led to increased DENV replication. Furthermore, overexpression of wRNase HI, in the absence of Wolbachia, led to reduced replication of a positive sense RNA virus, but had no effect on a negative sense RNA virus, a familiar scenario in Wolbachia-infected cells. Altogether, our results provide compelling evidence for the missing link between early Wolbachia-mediated virus blocking and degradation of viral RNA. These findings and the successful pioneered knockdown of Wolbachia genes using antisense RNA in cell line and mosquitoes enable new ways to manipulate and study the complex endosymbiont-host interactions.}, }
@article {pmid36628964, year = {2023}, author = {Durand, S and Lheraud, B and Giraud, I and Bech, N and Grandjean, F and Rigaud, T and Peccoud, J and Cordaux, R}, title = {Heterogeneous distribution of sex ratio distorters in natural populations of the isopod Armadillidium vulgare.}, journal = {Biology letters}, volume = {19}, number = {1}, pages = {20220457}, doi = {10.1098/rsbl.2022.0457}, pmid = {36628964}, issn = {1744-957X}, abstract = {In the isopod Armadillidium vulgare, many females produce progenies with female-biased sex ratios, owing to two feminizing sex ratio distorters (SRD): Wolbachia endosymbionts and the f element. We investigated the distribution and population dynamics of these SRD and mitochondrial DNA variation in 16 populations from Europe and Japan. Confirming and extending results from the 1990s, we found that the SRD are present at variable frequencies in populations and that the f element is overall more frequent than Wolbachia. The two SRD never co-occur at high frequency in any population, suggesting an apparent mutual exclusion. We also detected Wolbachia or the f element in some males, which probably reflects insufficient titer to induce feminization or presence of masculinizing alleles. Our results are consistent with a single integration event of a Wolbachia genome in the A. vulgare genome at the origin of the f element, which contradicts an earlier hypothesis of frequent losses and gains. We identified strong linkage between Wolbachia strains and mitochondrial haplotypes, but no association between the f element and mitochondrial background. Our results open new perspectives on SRD evolutionary dynamics in A. vulgare, the evolution of genetic conflicts and their impact on the variability of sex determination systems.}, }
@article {pmid36627918, year = {2023}, author = {Singh, T and Sakai, K and Ishida-Castañeda, J and Iguchi, A}, title = {Short-term improvement of heat tolerance in naturally growing Acropora corals in Okinawa.}, journal = {PeerJ}, volume = {11}, number = {}, pages = {e14629}, pmid = {36627918}, issn = {2167-8359}, abstract = {Mass bleaching and subsequent mortality of reef corals by heat stress has increased globally since the late 20th century, due to global warming. Some experimental studies have reported that corals may increase heat tolerance for short periods, but only a few such studies have monitored naturally-growing colonies. Therefore, we monitored the survival, growth, and bleaching status of Acropora corals in fixed plots by distinguishing individual colonies on a heat-sensitive reef flat in Okinawa, Japan. The level of heat stress, assessed by the modified version of degree heating week duration in July and August, when the seawater temperature was the highest, was minimally but significantly higher in 2017 than in 2016; however, the same colonies exhibited less bleaching and mortality in 2017 than in 2016. Another study conducted at the same site showed that the dominant unicellular endosymbiotic algal species did not change before and after the 2016 bleaching, indicating that shifting and switching of the Symbiodiniaceae community did not contribute to improved heat tolerance. Colonies that suffered from partial mortality in 2016 were completely bleached at higher rates in 2017 than those without partial mortality in 2016. The present results suggest that either genetic or epigenetic changes in coral hosts and/or algal symbionts, or the shifting or switching of microbes other than endosymbionts, may have improved coral holobiont heat tolerance.}, }
@article {pmid36626858, year = {2023}, author = {Husnik, F}, title = {Organellogenesis: Host proteins control symbiont cell divisions.}, journal = {Current biology : CB}, volume = {33}, number = {1}, pages = {R22-R25}, doi = {10.1016/j.cub.2022.11.028}, pmid = {36626858}, issn = {1879-0445}, abstract = {Understanding the order and importance of events through which endosymbionts transition into cellular organelles (organellogenesis) is central to hypotheses about the origin of the eukaryotic cell. A new study on host-symbiont integration in a unicellular eukaryote reveals host-derived cell-division proteins that are targeted to the cell envelope of a bacterial endosymbiont and involved in its cell division.}, }
@article {pmid36624259, year = {2023}, author = {Zhang, S and Wang, T and Lima, RM and Pettkó-Szandtner, A and Kereszt, A and Downie, JA and Kondorosi, E}, title = {Widely conserved AHL transcription factors are essential for NCR gene expression and nodule development in Medicago.}, journal = {Nature plants}, volume = {}, number = {}, pages = {}, pmid = {36624259}, issn = {2055-0278}, abstract = {Symbiotic nitrogen fixation by Rhizobium bacteria in the cells of legume root nodules alleviates the need for nitrogen fertilizers. Nitrogen fixation requires the endosymbionts to differentiate into bacteroids which can be reversible or terminal. The latter is controlled by the plant, it is more beneficial and has evolved in multiple clades of the Leguminosae family. The plant effectors of terminal differentiation in inverted repeat-lacking clade legumes (IRLC) are nodule-specific cysteine-rich (NCR) peptides, which are absent in legumes such as soybean where there is no terminal differentiation of rhizobia. It was assumed that NCRs co-evolved with specific transcription factors, but our work demonstrates that expression of NCR genes does not require NCR-specific transcription factors. Introduction of the Medicago truncatula NCR169 gene under its own promoter into soybean roots resulted in its nodule-specific expression, leading to bacteroid changes associated with terminal differentiation. We identified two AT-Hook Motif Nuclear Localized (AHL) transcription factors from both M. truncatula and soybean nodules that bound to AT-rich sequences in the NCR169 promoter inducing its expression. Whereas mutation of NCR169 arrested bacteroid development at a late stage, the absence of MtAHL1 or MtAHL2 completely blocked bacteroid differentiation indicating that they also regulate other NCR genes required for the development of nitrogen-fixing nodules. Regulation of NCRs by orthologous transcription factors in non-IRLC legumes opens up the possibility of increasing the efficiency of nitrogen fixation in legumes lacking NCRs.}, }
@article {pmid36617670, year = {2023}, author = {Torp, MK and Vaage, J and Stensløkken, KO}, title = {Mitochondria-derived damage associated molecular patterns and inflammation in the ischemic-reperfused heart.}, journal = {Acta physiologica (Oxford, England)}, volume = {}, number = {}, pages = {e13920}, doi = {10.1111/apha.13920}, pmid = {36617670}, issn = {1748-1716}, abstract = {Cardiac cell death after myocardial infarction release endogenous structures termed damage associated molecular patterns (DAMPs) that trigger the innate immune system and initiate a sterile inflammation in the myocardium. Cardiomyocytes are energy demanding cells and 30% of their volume are mitochondria. Mitochondria are evolutionary endosymbionts originating from bacteria containing molecular patterns similar to bacteria, termed mitochondrial DAMPs (mDAMPs). Consequently, mitochondrial debris may be particularly immunogenic and damaging. However, the role of mDAMPs in myocardial infarction is not clarified. Identifying the most harmful mDAMPs and inhibiting their early inflammatory signaling may reduce infarct size and the risk of developing post-infarct heart failure. The focus of this review is the role of mDAMPs in the immediate pro-inflammatory phase after myocardial infarction before arrival of immune cells in the myocardium. We discuss different mDAMPs, their role in physiology and present knowledge regarding their role in the inflammatory response of acute myocardial infarction.}, }
@article {pmid36605741, year = {2022}, author = {Büttner, H and Pidot, SJ and Scherlach, K and Hertweck, C}, title = {Endofungal bacteria boost anthelminthic host protection with the biosurfactant symbiosin.}, journal = {Chemical science}, volume = {14}, number = {1}, pages = {103-112}, pmid = {36605741}, issn = {2041-6520}, abstract = {Effective protection of soil fungi from predators is crucial for their survival in the niche. Thus, fungi have developed efficient defence strategies. We discovered that soil beneficial Mortierella fungi employ a potent cytotoxin (necroxime) against fungivorous nematodes. Interestingly, this anthelminthic agent is produced by bacterial endosymbionts (Candidatus Mycoavidus necroximicus) residing within the fungus. Analysis of the symbiont's genome indicated a rich biosynthetic potential, yet nothing has been known about additional metabolites and their potential synergistic functions. Here we report that two distinct Mortierella endosymbionts produce a novel cyclic lipodepsipeptide (symbiosin), that is clearly of bacterial origin, but has striking similarities to various fungal specialized metabolites. The structure and absolute configuration of symbiosin were fully elucidated. By comparative genomics of symbiosin-positive strains and in silico analyses of the deduced non-ribosomal synthetases, we assigned the (sym) biosynthetic gene cluster and proposed an assembly line model. Bioassays revealed that symbiosin is not only an antibiotic, in particular against mycobacteria, but also exhibits marked synergistic effects with necroxime in anti-nematode tests. By functional analyses and substitution experiments we found that symbiosin is a potent biosurfactant and that this particular property confers a boost in the anthelmintic action, similar to formulations of therapeutics in human medicine. Our findings illustrate that "combination therapies" against parasites already exist in ecological contexts, which may inspire the development of biocontrol agents and therapeutics.}, }
@article {pmid36604515, year = {2023}, author = {Dharamshi, JE and Köstlbacher, S and Schön, ME and Collingro, A and Ettema, TJG and Horn, M}, title = {Gene gain facilitated endosymbiotic evolution of Chlamydiae.}, journal = {Nature microbiology}, volume = {8}, number = {1}, pages = {40-54}, pmid = {36604515}, issn = {2058-5276}, abstract = {Chlamydiae is a bacterial phylum composed of obligate animal and protist endosymbionts. However, other members of the Planctomycetes-Verrucomicrobia-Chlamydiae superphylum are primarily free living. How Chlamydiae transitioned to an endosymbiotic lifestyle is still largely unresolved. Here we reconstructed Planctomycetes-Verrucomicrobia-Chlamydiae species relationships and modelled superphylum genome evolution. Gene content reconstruction from 11,996 gene families suggests a motile and facultatively anaerobic last common Chlamydiae ancestor that had already gained characteristic endosymbiont genes. Counter to expectations for genome streamlining in strict endosymbionts, we detected substantial gene gain within Chlamydiae. We found that divergence in energy metabolism and aerobiosis observed in extant lineages emerged later during chlamydial evolution. In particular, metabolic and aerobic genes characteristic of the more metabolically versatile protist-infecting chlamydiae were gained, such as respiratory chain complexes. Our results show that metabolic complexity can increase during endosymbiont evolution, adding an additional perspective for understanding symbiont evolutionary trajectories across the tree of life.}, }
@article {pmid36602726, year = {2023}, author = {Xiao, B and Li, D and Liao, B and Zheng, H and Yang, X and Xie, Y and Xie, Z and Li, C}, title = {Effects of microplastic combined with Cr(III) on apoptosis and energy pathway of coral endosymbiont.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {36602726}, issn = {1614-7499}, abstract = {The combined effect of polyethylene (PE) microplastics and chromium (Cr(III)) on the scleractinian coral Acropora pruinosa (A. pruinosa) was investigated. The endpoints analysed in this study included the endosymbiont density, the chlorophyll a + c content, and the activity of enzymes involved in apoptosis (caspase-1, caspase-3), glycolysis (lactate dehydrogenase, LDH), the pentose phosphate pathway (glucose-6-phosphate dehydrogenase, G6PDH) and electron transfer coenzyme (nicotinamide adenine dinucleotide, NAD[+]/NADH). During the 7-day exposure to PE and Cr(III) stress, the endosymbiont density and chlorophyll content decreased gradually. The caspase-1 and caspase-3 activities increased in the high-concentration Cr(III) exposure group. Furthermore, the LDH and G6PDH activities decreased significantly, and the NAD[+]/NADH was decreased significantly. In summary, the results showed that PE and Cr(III) stress inhibited the endosymbiont energy metabolism enzymes and further led to endosymbiont apoptosis in coral. In addition, under exposure to the combination of stressors, when the concentration of Cr(III) remained at 1 × 10[-2] mg/L, the toxic effects of heavy metals on the endosymbiont were temporarily relieved with elevated PE concentrations. In contrast, when coral polyps were exposed to 5 mg/L PE and increasing Cr(III) concentrations, their metabolic activities were seriously disturbed, which increased the burden of energy consumption. In the short term, the toxic effect of Cr(III) was more obvious than that of PE because Cr(III) exposure leads to endosymbiont apoptosis and irreversible damage. This is the first study to provide insights into the combined effect of microplastic and Cr(III) stress on the apoptosis and energy pathways of coral endosymbionts. This study suggested that microplastics combined with Cr(III) are an important factor affecting the apoptosis and energy metabolism of endosymbionts, accelerating the collapse of the balance between the coral host and symbiotic endosymbiont.}, }
@article {pmid36602054, year = {2023}, author = {Jin, L and Zhang, BW and Lu, JW and Liao, JA and Zhu, QJ and Lin, Y and Yu, XQ}, title = {The mechanism of Cry41-related toxin against Myzus persicae based on its interaction with Buchnera-derived ATP-dependent-6-phosphofructokinase.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7340}, pmid = {36602054}, issn = {1526-4998}, abstract = {BACKGROUND: Myzus persicae (Hemiptera: Aphididae) is one of the most notorious pests to many crops worldwide. Most Cry toxins produced by Bacillus thuringiensis show very low toxicity to M. persicae; however, a study showed that Cry41-related toxin had moderate toxic activity against M. persicae. In our previous work, potential Cry41-related toxin binding proteins in M. persicae were identified, including Cathepsin B, calcium-transporting ATPase, and Buchnera-derived ATP-dependent-6-phosphofructokinase (PFKA). Buchnera is an endosymbiont present in almost all aphids and it provides necessary nutrients for aphid's growth. This study investigated the role of Buchnera-derived PFKA in Cry41-related toxicity against M. persicae.<br><br>RESULTS: In this study, recombinant PFKA was expressed and purified, and in vitro assays revealed that PFKA bound to Cry41-related toxin, and Cry41-related toxin at 25 &#x3bc;g/mL significantly inhibited the activity of PFKA. Additionally, when M. persicae was treated with 30 &#x3bc;g/mL of Cry41-related toxin for 24 h, the expression of dnak, a single-copy gene in Buchnera, was significantly decreased, indicating a decrease in the number of Buchnera.<br><br>CONCLUSION: Our results suggest that Cry41-related toxin interacts with Buchnera-derived PFKA to inhibit its enzymatic activity and likely impair cell viability, resulting in a decrease in the number of Buchnera, and finally leading to M. persicae death. These findings open new perspectives in understanding the mode of action of Cry toxins and are useful to help improve the Cry toxicity for aphid control. This article is protected by copyright. All rights reserved.}, }
@article {pmid36598738, year = {2023}, author = {Scholz, H}, title = {From Natural Behavior to Drug Screening: Invertebrates as Models to Study Mechanisms Associated with Alcohol Use Disorders.}, journal = {Current topics in behavioral neurosciences}, volume = {}, number = {}, pages = {}, pmid = {36598738}, issn = {1866-3370}, abstract = {Humans consume ethanol-containing beverages, which may cause an uncontrollable or difficult-to-control intake of ethanol-containing liquids and may result in alcohol use disorders. How the transition at the molecular level from "normal" ethanol-associated behaviors to addictive behaviors occurs is still unknown. One problem is that the components contributing to normal ethanol intake and their underlying molecular adaptations, especially in neurons that regulate behavior, are not clear. The fruit fly Drosophila melanogaster and the earthworm Caenorhabditis elegans show behavioral similarities to humans such as signs of intoxication, tolerance, and withdrawal. Underlying the phenotypic similarities, invertebrates and vertebrates share mechanistic similarities. For example in Drosophila melanogaster, the dopaminergic neurotransmitter system regulates the positive reinforcing properties of ethanol and in Caenorhabditis elegans, serotonergic neurons regulate feeding behavior. Since these mechanisms are fundamental molecular mechanisms and are highly conserved, invertebrates are good models for uncovering the basic principles of neuronal adaptation underlying the behavioral response to ethanol. This review will focus on the following aspects that might shed light on the mechanisms underlying normal ethanol-associated behaviors. First, the current status of what is required at the behavioral and cellular level to respond to naturally occurring levels of ethanol is summarized. Low levels of ethanol delay the development and activate compensatory mechanisms that in turn might be beneficial for some aspects of the animal's physiology. Repeated exposure to ethanol however might change brain structures involved in mediating learning and memory processes. The smell of ethanol is already a key component in the environment that is able to elicit behavioral changes and molecular programs. Minimal networks have been identified that regulate normal ethanol consumption. Other environmental factors that influence ethanol-induced behaviors include the diet, dietary supplements, and the microbiome. Second, the molecular mechanisms underlying neuronal adaptation to the cellular stressor ethanol are discussed. Components of the heat shock and oxidative stress pathways regulate adaptive responses to low levels of ethanol and in turn change behavior. The adaptive potential of the brain cells is challenged when the organism encounters additional cellular stressors caused by aging, endosymbionts or environmental toxins or excessive ethanol intake. Finally, to underline the conserved nature of these mechanisms between invertebrates and higher organisms, recent approaches to identify drug targets for ethanol-induced behaviors are provided. Already approved drugs regulate ethanol-induced behaviors and they do so in part by interfering with cellular stress pathways. In addition, invertebrates have been used to identify new compounds targeting molecules involved in the regulation in ethanol withdrawal-like symptoms. This review primarily highlights the advances of the last 5 years concerning Drosophila melanogaster, but also provides intriguing examples of Caenorhabditis elegans and Apis mellifera in support.}, }
@article {pmid36597782, year = {2023}, author = {Mahdhi, A and Mars, M and Rejili, M}, title = {Members of Ensifer and Rhizobium genera are new bacterial endosymbionts nodulating Pisum sativum (L.).}, journal = {FEMS microbiology ecology}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsec/fiad001}, pmid = {36597782}, issn = {1574-6941}, abstract = {Eighty-four Pisum sativum legume nodulating bacteria (LNB) were isolated from seven geographical sites from southern Tunisia. Phylogenetic analyses based on partial sequences of 16S rRNA gene and the housekeeping genes glnII, and recA grouped strains into six clusters, four of which belonged to the genus Rhizobium and two to the Ensifer genus. Among Rhizobium clusters, 41 strains were affiliated to Rhizobium leguminosarum, two strains to R. pisi, two strains to R. etli, and interestingly two strains belonged to previously undescribed Rhizobium species. The remaining two strains were closely related to Ensifer medicae (two strains) and Ensifer meliloti (two strains). A symbiotic nodC gene-based phylogeny and host specificity test showed that all Rhizobium strains nodulating pea belonged to the symbiovar viciae, whereas the Ensifer strains were associated with the symbiovar meliloti never described to date. All strains under investigation differed in the number of induced root nodules and the effectiveness of atmospheric nitrogen fixation. The R. leguminosarum PsZA23, R. leguminosarum PsGBL42 and E. medicae PsTA22a, forming the most effective symbiosis with the plant host, are potential candidates for inoculation programs.}, }
@article {pmid36589876, year = {2022}, author = {Uni, S and Mat Udin, AS and Tan, PE and Rodrigues, J and Martin, C and Junker, K and Agatsuma, T and Low, VL and Lim, YA and Saijuntha, W and Omar, H and Zainuri, NA and Fukuda, M and Kimura, D and Matsubayashi, M and Uga, S and Takaoka, H and Azirun, MS and Ramli, R}, title = {Description and molecular characterisation of Pelecitus copsychi Uni, Mat Udin &amp; Martin n. sp. (Nematoda: Onchocercidae) from the white-rumped shama Copsychus malabaricus (Scopoli) (Passeriformes: Muscicapidae) of Pahang, Malaysia.}, journal = {Current research in parasitology &amp; vector-borne diseases}, volume = {2}, number = {}, pages = {100078}, pmid = {36589876}, issn = {2667-114X}, abstract = {Species of the genus Pelecitus Railliet &amp; Henry, 1910 the most widely distributed avian filariae in Africa and South America. Zoonotic cases in humans were reported in South America. While investigating the filarial fauna of wild animals in Malaysia, we discovered an undescribed filaria from the swollen footpad of the left leg of Copsychus malabaricus (Scopoli) in Pahang, Peninsular Malaysia. Adults of both sexes have a corkscrew-shaped body. Based on comparison of their morphological characteristics (i.e. pre-oesophageal cuticular ring distinct, oesophagus divided, vulva protuberant and situated at the level of anterior half of oesophagus, spicules strongly sclerotized and left spicule with broad blade) with other Pelecitus species, they are here described as Pelecitus copsychi Uni, Mat Udin &amp; Martin n. sp. Multi-locus sequence analyses based on seven genes (12S rDNA, cox1, 18S rDNA, 28S rDNA, MyoHC, rbp1 and hsp70) were performed to determine the phylogenetic position of the new species. The calculated p-distance between the cox1 gene sequences for P. copsychi n. sp. and Pelecitus fulicaeatrae (Diesing, 1861) was 14.1%. Intraspecific genetic variation between two individuals of the new species was 0.4%. In both the Bayesian inference and maximum-likelihood trees, P. copsychi n. sp. was positioned in the second clade of ONC5, containing three genera of the subfamily Dirofilariinae (Foleyella Seurat, 1917, Pelecitus and Loa Stiles, 1905). Immunostaining and molecular analyses remained negative for the presence of Wolbachia endosymbionts. Our findings corroborate the division of the subfamily Dirofilariinae into ONC3 with Dirofilaria Railliet &amp; Henry, 1911 and ONC5 with Pelecitus.}, }
@article {pmid36585292, year = {2022}, author = {Minahan, NT and Wu, WJ and Tsai, KH}, title = {Rickettsia felis is an emerging human pathogen associated with cat fleas: A review of findings in Taiwan.}, journal = {Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jmii.2022.12.006}, pmid = {36585292}, issn = {1995-9133}, abstract = {Rickettsia felis is an emerging rickettsial agent principally associated with cat fleas (Ctenocephalides felis), formerly discovered in 1990. Since then, clinical cases of R. felis infection have been identified globally by specific DNA sequences in patients with undifferentiated febrile illness, including in Taiwan, but such evidence is limited. R. felis rickettsiosis is self-limiting and easily treated with doxycycline, but its diagnosis remains a challenge. Environmental risk factors for R. felis rickettsiosis have yet to be clearly demonstrated, and its transmission biology is incompletely understood. Cat fleas are naturally infected with R. felis at varying rates, and vector competence in the transmission of R. felis has been demonstrated in animal models, including dogs, which may serve as reservoir hosts. In northern Taiwan, despite ∼20% of cat fleas infesting companion animals consistently found to be infected with R. felis, only a few cases of potential R. felis infection have been identified through a retrospective serological investigation, though without molecular confirmation. Ecological studies have identified divergent R. felis-like organisms in different arthropod hosts, but these strains appear to serve as nonpathogenic endosymbionts. Although its association with disease is limited, we believe cat flea-borne R. felis warrants increased recognition in an aging population due to immunosenescence and the proximity of companion animals to the elderly. Adopting a One Health approach involving collaboration and communication between clinicians, veterinarians, public health practitioners, and environmental scientists will improve our knowledge about this neglected pathogen and promote the prevention and control of vector-borne diseases.}, }
@article {pmid36569075, year = {2022}, author = {Obert, T and Zhang, T and Rurik, I and Vďačný, P}, title = {First molecular evidence of hybridization in endosymbiotic ciliates (Protista, Ciliophora).}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1067315}, pmid = {36569075}, issn = {1664-302X}, abstract = {Hybridization is an important evolutionary process that can fuel diversification via formation of hybrid species or can lead to fusion of previously separated lineages by forming highly diverse species complexes. We provide here the first molecular evidence of hybridization in wild populations of ciliates, a highly diverse group of free-living and symbiotic eukaryotic microbes. The impact of hybridization was studied on the model of Plagiotoma, an obligate endosymbiont of the digestive tube of earthworms, using split decomposition analyses and species networks, 2D modeling of the nuclear rRNA molecules and compensatory base change analyses as well as multidimensional morphometrics. Gene flow slowed down and eventually hampered the diversification of Lumbricus-dwelling plagiotomids, which collapsed into a single highly variable biological entity, the P. lumbrici complex. Disruption of the species boundaries was suggested also by the continuum of morphological variability in the phenotypic space. On the other hand, hybridization conspicuously increased diversity in the nuclear rDNA cistron and somewhat weakened the host structural specificity of the P. lumbrici complex, whose members colonize a variety of phylogenetically closely related anecic and epigeic earthworms. By contrast, another recorded species, P. aporrectodeae sp. n., showed no signs of introgression, no variability in the rDNA cistron, and very high host specificity. These contrasting eco-evolutionary patterns indicate that hybridization might decrease the alpha-diversity by dissolving species boundaries, weaken the structural host specificity by broadening ecological amplitudes, and increase the nuclear rDNA variability by overcoming concerted evolution within the P. lumbrici species complex.}, }
@article {pmid36558828, year = {2022}, author = {Cabezas-Cruz, A and Fogaça, AC}, title = {Lock and Key: Why Rickettsia Endosymbionts Do Not Harm Vertebrate Hosts?.}, journal = {Pathogens (Basel, Switzerland)}, volume = {11}, number = {12}, pages = {}, doi = {10.3390/pathogens11121494}, pmid = {36558828}, issn = {2076-0817}, abstract = {Are tick endosymbionts transmitted to and able to injure vertebrate hosts [...].}, }
@article {pmid36555070, year = {2022}, author = {Fan, ZY and Liu, Y and He, ZQ and Wen, Q and Chen, XY and Khan, MM and Osman, M and Mandour, NS and Qiu, BL}, title = {Rickettsia Infection Benefits Its Whitefly Hosts by Manipulating Their Nutrition and Defense.}, journal = {Insects}, volume = {13}, number = {12}, pages = {}, doi = {10.3390/insects13121161}, pmid = {36555070}, issn = {2075-4450}, abstract = {Endosymbionts play an essential role in the biology, physiology and immunity of insects. Many insects, including the whitefly Bemisia&amp;nbsp;tabaci, are infected with the facultative endosymbiont Rickettsia. However, the mutualism between Rickettsia and its whitefly host remains unclear. This study investigated the biological and physiological benefits of Rickettsia infection to B. tabaci. Results revealed that infection of Rickettsia increased the fertility, the survival rate from nymph to adult and the number of female whiteflies. In addition, this facilitation caused a significant reduction in nymphal developmental duration but did not affect percentage rate of egg hatching. Rickettsia infected B. tabaci had significantly higher glycogen, soluble sugar and trehalose contents than Rickettsia negative B. tabaci individuals. Rickettsia also improved the immunity of its whitefly hosts. Rickettsia infested B. tabaci had lower mortality rates and higher semi-lethal concentrations (LC50) when exposed to the fungus Akanthomyces&amp;nbsp;attenuatus and the insecticides imidacloprid and spirotetramat. The percentage of parasitism by Encarsia&amp;nbsp;formosa was also reduced by Rickettsia infection. Overall, Rickettsia infection benefits B. tabaci by improving the nutritional composition of its host, and also protects B. tabaci by enhancing its resistance towards insecticides (imidacloprid and spirotetramat), entomopathogenic fungi (A. attenuatus) and its main parasitoid (E.&amp;nbsp;formosa); all of which could significantly impact on current management strategies.}, }
@article {pmid36555052, year = {2022}, author = {Tomanović, &#x17d; and Kavallieratos, NG and Ye, Z and Nika, EP and Petrović, A and Vollhardt, IMG and Vorburger, C}, title = {Cereal Aphid Parasitoids in Europe (Hymenoptera: Braconidae: Aphidiinae): Taxonomy, Biodiversity, and Ecology.}, journal = {Insects}, volume = {13}, number = {12}, pages = {}, doi = {10.3390/insects13121142}, pmid = {36555052}, issn = {2075-4450}, abstract = {Cereals are very common and widespread crops in Europe. Aphids are a diverse group of herbivorous pests on cereals and one of the most important limiting factors of cereal production. Here, we present an overview of knowledge about the taxonomy, biodiversity, and ecology of cereal aphid parasitoids in Europe, an important group of natural enemies contributing to cereal aphid control. We review the knowledge obtained from the integrative taxonomy of 26 cereal aphid primary parasitoid species, including two allochthonous species (Lysiphlebus testaceipes and Trioxys sunnysidensis) and two recently described species (Lipolexis labialis and Paralipsis brachycaudi). We further review 28 hyperparasitoid species belonging to three hymenopteran superfamilies and four families (Ceraphronoidea: Megaspillidae; Chalcidoidea: Pteromalidae, Encyrtidae; Cynipoidea: Figitidae). We also compile knowledge on the presence of secondary endosymbionts in cereal aphids, as these are expected to influence the community composition and biocontrol efficiency of cereal aphid parasitoids. To study aphid-parasitoid-hyperparasitoid food webs more effectively, we present two kinds of DNA-based approach: (i) diagnostic PCR (mainly multiplex PCR), and (ii) DNA sequence-based methods. Finally, we also review the effects of landscape complexity on the different trophic levels in the food webs of cereal aphids and their associated parasitoids, as well as the impacts of agricultural practices and environmental variation.}, }
@article {pmid36554995, year = {2022}, author = {Gümüşsoy, A and Yüksel, E and Özer, G and İmren, M and Canhilal, R and Amer, M and Dababat, AA}, title = {Identification and Biocontrol Potential of Entomopathogenic Nematodes and Their Endosymbiotic Bacteria in Apple Orchards against the Codling Moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae).}, journal = {Insects}, volume = {13}, number = {12}, pages = {}, doi = {10.3390/insects13121085}, pmid = {36554995}, issn = {2075-4450}, abstract = {The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is one of the major pests in pome fruit production worldwide. Heavy treatment of the larvae of C. pomonella with insecticides triggered the development of resistance to many groups of insecticides. In addition, the increasing concern about the adverse effects of synthetic insecticides on human health and the environment has led to the development of sustainable and eco-friendly control practices for C. pomonella. The entomopathogenic nematodes (EPNs) (Steinernema and Heterorhabditis spp.) and their endosymbionts (Xenorhabdus and Photorhabdus spp.) represent a newly emerging approach to controlling a wide range of insect pests. In the present study, field surveys were conducted in apple orchards to isolate and identify EPNs and their endosymbionts and evaluate their insecticidal efficacy on the larvae of C. pomonella. EPNs were isolated from 12 of 100 soil samples (12%). Seven samples were identified as Steinernema feltiae (Filipjev, 1934) (Rhabditida: Steinernematidae), whereas five samples were assigned to Heterorhabditis bacteriophora (Poinar, 1976) (Rhabditida: Heterorhabditidae). The pathogenicity of the EPN species/isolates was screened on the last instar larvae of G. mellonella. The two most pathogenic isolates from each EPN species were tested against fifth instar larvae of C. pomonella under controlled conditions. The maximum mortality (100%) was achieved by all EPN species/isolates at a concentration of 100 IJs/larva 96 h after treatment. The endosymbionts of selected H. bacteriophora and S. feltiae species were identified as Photorhabdus luminescens subsp. kayaii and Xenorhabdus bovienii, respectively. The mortality rates ranged between 25 and 62% when the fifth larval instar larvae of C. pomonella were exposed to the treatment of cell-free supernatants of symbiotic bacteria. In essence, the present survey indicated that EPNs and their symbiotic bacteria have good potential for biological control of C. pomonella.}, }
@article {pmid36548668, year = {2022}, author = {Zeng, W and Li, Z and Jiang, T and Cheng, D and Yang, L and Hang, T and Duan, L and Zhu, D and Fang, Y and Zhang, Y}, title = {Identification of Bacterial Communities and Tick-Borne Pathogens in Haemaphysalis spp. Collected from Shanghai, China.}, journal = {Tropical medicine and infectious disease}, volume = {7}, number = {12}, pages = {}, doi = {10.3390/tropicalmed7120413}, pmid = {36548668}, issn = {2414-6366}, abstract = {Ticks can carry and transmit a large number of pathogens, including bacteria, viruses and protozoa, posing a huge threat to human health and animal husbandry. Previous investigations have shown that the dominant species of ticks in Shanghai are Haemaphysalis flava and Haemaphysalis longicornis. However, no relevant investigations and research have been carried out in recent decades. Therefore, we investigated the bacterial communities and tick-borne pathogens (TBPs) in Haemaphysalis spp. from Shanghai, China. Ixodid ticks were collected from 18 sites in Shanghai, China, and identified using morphological and molecular methods. The V3-V4 hypervariable regions of the bacterial 16S rRNA gene were amplified from the pooled tick DNA samples and subject to metagenomic analysis. The microbial diversity in the tick samples was estimated using the alpha diversity that includes the observed species index and Shannon index. The Unifrac distance matrix as determined using the QIIME software was used for unweighted Unifrac Principal coordinates analysis (PCoA). Individual tick DNA samples were screened with genus-specific or group-specific nested polymerase chain reaction (PCR) for these TBPs and combined with a sequencing assay to confirm the results of the V3-V4 hypervariable regions of the bacterial 16S rRNA gene. We found H. flava and H. longicornis to be the dominant species of ticks in Shanghai in this study. Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria are the main bacterial communities of Haemaphysalis spp. The total species abundances of Proteobacteria, Firmicutes and Bacteroidetes, are 48.8%, 20.8% and 18.1%, respectively. At the level of genus analysis, H. longicornis and H. flava carried at least 946 genera of bacteria. The bacteria with high abundance include Lactobacillus, Coxiella, Rickettsia and Muribaculaceae. Additionally, Rickettsia rickettsii, Rickettsia japonica, Candidatus Rickettsia jingxinensis, Anaplasma bovis, Ehrlichia ewingii, Ehrlichia chaffeensis, Coxiella spp. and Coxiella-like endosymbiont were detected in Haemaphysalis spp. from Shanghai, China. This study is the first report of bacterial communities and the prevalence of some main pathogens in Haemaphysalis spp. from Shanghai, China, and may provide insights and evidence for bacterial communities and the prevalence of the main pathogen in ticks. This study also indicates that people and other animals in Shanghai, China, are exposed to several TBPs.}, }
@article {pmid36546855, year = {2022}, author = {Fujiwara, A and Meng, XY and Kamagata, Y and Tsuchida, T}, title = {Subcellular Niche Segregation of Co-Obligate Symbionts in Whiteflies.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0468422}, doi = {10.1128/spectrum.04684-22}, pmid = {36546855}, issn = {2165-0497}, abstract = {Many insects contain endosymbiotic bacteria within their bodies. In multiple endosymbiotic systems comprising two or more symbionts, each of the symbionts is generally localized in a different host cell or tissue. Bemisia tabaci (Sweet potato whitefly) possesses a unique endosymbiotic system where co-obligate symbionts are localized in the same bacteriocytes. Using fluorescence in situ hybridization, we found that endosymbionts in B. tabaci MEAM1 occupy distinct subcellular habitats, or niches, within a single bacteriocyte. Hamiltonella was located adjacent to the nucleus of the bacteriocyte, while Portiera was present in the cytoplasm surrounding Hamiltonella. Immunohistochemical analysis revealed that the endoplasmic reticulum separates the two symbionts. Habitat segregation was maintained for longer durations in female bacteriocytes. The same segregation was observed in three genetically distinct B. tabaci groups (MEAM1, MED Q1, and Asia II 6) and Trialeurodes vaporariorum, which shared a common ancestor with Bemisia over 80 million years ago, even though the coexisting symbionts and the size of bacteriocytes were different. These results suggest that the habitat segregation system existed in the common ancestor and was conserved in both lineages, despite different bacterial partners coexisting with Portiera. Our findings provide insights into the evolution and maintenance of complex endosymbiotic systems and highlight the importance of organelles for the construction of separate niches for endosymbionts. IMPORTANCE Co-obligate endosymbionts in B. tabaci are exceptionally localized within the same bacteriocyte (a specialized cell for endosymbiosis), but the underlying mechanism for their coexistence remains largely unknown. This study provides evidence for niche segregation at the subcellular level between the two symbionts. We showed that the endoplasmic reticulum is a physical barrier separating the two species. Despite differences in co-obligate partners, this subcellular niche segregation was conserved across various whitefly species. The physical proximity of symbionts may enable the efficient biosynthesis of essential nutrients via shared metabolic pathways. The expression "Good fences make good neighbors" appears to be true for insect endosymbiotic systems.}, }
@article {pmid36534288, year = {2023}, author = {Espino-Vázquez, AN and Córdova-López, G and Cabrera-Rangel, JF and Mendoza-Servín, JV and Partida-Martínez, LP}, title = {The Rhizopus Holobiont: A Model to Decipher Fungal-Bacterial-Viral Symbioses.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2610}, number = {}, pages = {137-147}, pmid = {36534288}, issn = {1940-6029}, abstract = {Rhizopus microsporus is an early-diverging fungal species that inhabits the soil, is used for the fermentation of diverse Asian and African foods, and can be a pathogen of plants, animals, and humans.Toxin-producing strains of R. microsporus live in symbiosis with Gram-negative betaproteobacteria from the genus Mycetohabitans (Burkholderia sensu lato). These bacterial endosymbionts increase the metabolic plasticity of the fungal holobiont by producing the "mycotoxins," control their asexual reproduction, and influence their sexual success. Recently, we identified two viruses of the genus Narnavirus in some R. microsporus strains that harbor Mycetohabitans. By eliminating bacteria and/or viruses from host R. microsporus strains, we have been able to study the role of these symbionts in fungal biology. Remarkably, the absence of these bacterial and viral symbionts decreases sexual reproduction. In this chapter, the method developed to eliminate and genotype the Narnavirus RmNV-20S and RmNV-23S in R. microsporus is described in detail.}, }
@article {pmid36533142, year = {2022}, author = {Zucker, F and Bischoff, V and Olo Ndela, E and Heyerhoff, B and Poehlein, A and Freese, HM and Roux, S and Simon, M and Enault, F and Moraru, C}, title = {New Microviridae isolated from Sulfitobacter reveals two cosmopolitan subfamilies of single-stranded DNA phages infecting marine and terrestrial Alphaproteobacteria.}, journal = {Virus evolution}, volume = {8}, number = {2}, pages = {veac070}, pmid = {36533142}, issn = {2057-1577}, abstract = {The Microviridae family represents one of the major clades of single-stranded DNA (ssDNA) phages. Their cultivated members are lytic and infect Proteobacteria, Bacteroidetes, and Chlamydiae. Prophages have been predicted in the genomes from Bacteroidales, Hyphomicrobiales, and Enterobacteriaceae and cluster within the 'Alpavirinae', 'Amoyvirinae', and Gokushovirinae. We have isolated 'Ascunsovirus oldenburgi' ICBM5, a novel phage distantly related to known Microviridae. It infects Sulfitobacter dubius SH24-1b and uses both a lytic and a carrier-state life strategy. Using ICBM5 proteins as a query, we uncovered in publicly available resources sixty-five new Microviridae prophages and episomes in bacterial genomes and retrieved forty-seven environmental viral genomes (EVGs) from various viromes. Genome clustering based on protein content and phylogenetic analysis showed that ICBM5, together with Rhizobium phages, new prophages, episomes, and EVGs cluster within two new phylogenetic clades, here tentatively assigned the rank of subfamily and named 'Tainavirinae' and 'Occultatumvirinae'. They both infect Rhodobacterales. Occultatumviruses also infect Hyphomicrobiales, including nitrogen-fixing endosymbionts from cosmopolitan legumes. A biogeographical assessment showed that tainaviruses and occultatumviruses are spread worldwide, in terrestrial and marine environments. The new phage isolated here sheds light onto new and diverse branches of the Microviridae tree, suggesting that much of the ssDNA phage diversity remains in the dark.}, }
@article {pmid36530420, year = {2022}, author = {Zhang, H and Gao, J and Ma, Z and Liu, Y and Wang, G and Liu, Q and Du, Y and Xing, D and Li, C and Zhao, T and Jiang, Y and Dong, Y and Guo, X and Zhao, T}, title = {Wolbachia infection in field-collected Aedes aegypti in Yunnan Province, southwestern China.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {1082809}, pmid = {36530420}, issn = {2235-2988}, abstract = {BACKGROUND: Wolbachia is gram-negative and common intracellular bacteria, which is maternally inherited endosymbionts and could expand their propagation in host populations by means of various manipulations. Recent reports reveal the natural infection of Wolbachia in Aedes Aegypti in Malaysia, India, Philippines, Thailand and the United States. At present, none of Wolbachia natural infection in Ae. aegypti has been reported in China.<br><br>METHODS: A total of 480 Ae. aegypti adult mosquitoes were collected from October and November 2018 based on the results of previous investigations and the distribution of Ae. aegypti in Yunnan. Each individual sample was processed and screened for the presence of Wolbachia by PCR with wsp primers. Phylogenetic trees for the wsp gene was constructed using the neighbour-joining method with 1,000 bootstrap replicates, and the p-distance distribution model of molecular evolution was applied.<br><br>RESULTS: 24 individual adult mosquito samples and 10 sample sites were positive for Wolbachia infection. The Wolbachia infection rate (IR) of each population ranged from 0 - 41.7%. The infection rate of group A alone was 0%-10%, the infection rate of group B alone was 0%-7.7%, and the infection rate of co-infection with A and B was 0-33.3%.<br><br>CONCLUSIONS: Wolbachia infection in wild Ae. aegypti in China is the first report based on PCR amplification of the Wolbachia wsp gene. The Wolbachia infection is 5%, and the wAlbA and wAlbB strains were found to be prevalent in the natural population of Ae. aegypti in Yunnan Province.}, }
@article {pmid36519169, year = {2022}, author = {Arai, H and Inoue, MN and Kageyama, D}, title = {Male-killing mechanisms vary between Spiroplasma species.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1075199}, doi = {10.3389/fmicb.2022.1075199}, pmid = {36519169}, issn = {1664-302X}, abstract = {Male-killing, a male-specific death of arthropod hosts during development, is induced by Spiroplasma (Mollicutes) endosymbionts of the Citri-Poulsonii and the Ixodetis groups, which are phylogenetically distant groups. Spiroplasma poulsonii induces male-killing in Drosophila melanogaster (Diptera) using the Spaid toxin that harbors ankyrin repeats, whereas little is known about the origin and mechanisms of male-killing induced by Spiroplasma ixodetis. Here, we analyzed the genome and the biological characteristics of a male-killing S. ixodetis strain sHm in the moth Homona magnanima (Tortricidae, Lepidoptera). Strain sHm harbored a 2.1 Mb chromosome and two potential plasmids encoding Type IV effectors, putatively involved in virulence and host-symbiont interactions. Moreover, sHm did not harbor the spaid gene but harbored 10 ankyrin genes that were homologous to those in other S. ixodetis strains. In contrast to the predominant existence of S. poulsonii in hemolymph, our quantitative PCR assays revealed a systemic distribution of strain sHm in H. magnanima, with particularly high titers in Malpighian tubules but low titers in hemolymph. Furthermore, transinfection assays confirmed that strain sHm can infect cultured cells derived from distantly related insects, namely Aedes albopictus (Diptera) and Bombyx mori (Lepidoptera). These results suggest different origins and characteristics of S. ixodetis- and S. poulsonii-induced male-killing.}, }
@article {pmid36516405, year = {2022}, author = {Roldán, EL and Stelinski, LL and Pelz-Stelinski, KS}, title = {Foliar Antibiotic Treatment Reduces Candidatus Liberibacter asiaticus Acquisition by the Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae), but Does not Reduce Tree Infection Rate.}, journal = {Journal of economic entomology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jee/toac200}, pmid = {36516405}, issn = {1938-291X}, abstract = {Huanglongbing (HLB), or citrus greening, is the most destructive disease of cultivated citrus worldwide. Candidatus Liberibacter asiaticus (CLas), the putative causal agent of HLB, is transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). In Florida, D. citri was first reported in 1998, and CLas was confirmed in 2005. Management of HLB relies on the use of insecticides to reduce vector populations. In 2016, antibiotics were approved to manage CLas infection in citrus. Diaphorina citri is host to several bacterial endosymbionts and reducing endosymbiont abundance is known to cause a corresponding reduction in host fitness. We hypothesized that applications of oxytetracycline and streptomycin would reduce: CLas populations in young and mature citrus trees, CLas acquisition by D. citri, and D. citri abundance. Our results indicate that treatment of citrus with oxytetracycline and streptomycin reduced acquisition of CLas by D. citri adults and emerging F1 nymphs as compared with that observed in trees treated only with insecticides, but not with antibiotics. However, under field conditions, neither antibiotic treatment frequency tested affected CLas infection of young or mature trees as compared with insecticide treatment alone (negative control); whereas trees enveloped with mesh screening that excluded vectors did prevent bacterial infection (positive control). Populations of D. citri were not consistently affected by antibiotic treatment under field conditions, as compared with an insecticide only comparison. Collectively, our results suggest that while foliar application of oxytetracycline and streptomycin to citrus reduces acquisition of CLas bacteria by the vector, even high frequency applications of these formulations under field conditions do not prevent or reduce tree infection.}, }
@article {pmid36515176, year = {2022}, author = {Wang, D and He, H and Wei, C}, title = {Cellular and potential molecular mechanisms underlying transovarial transmission of the obligate symbiont Sulcia in cicadas.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16310}, pmid = {36515176}, issn = {1462-2920}, abstract = {Vertical transmission of symbionts in insects is critical to persistence of symbioses across host generations. The key time point and related cellular/molecular mechanisms underlying the transmission in most insects remain unclear. Here, we reveal that in the bacteriome-endosymbiont system of the cicada Meimuna mongolica, the obligate symbiont Candidatus Sulcia muelleri (hereafter Sulcia) proliferates and migrates to the ovaries mainly after the adult emergence of cicadas. Sulcia cells swell to approximately twice their previous size with the outer membrane changed to be more irregular during this process. Almost all the Sulcia genes involved in biosynthesis of essential amino acids, heat shock protein, energy metabolism, DNA replication and repair and protein export were highly expressed in all life stages of cicadas. Among which, genes involved in DNA replication and synthesis of leucine and arginine were up-regulated in the newly emerged adults relative to 5[th] -instar nymphs. Signal transduction is the pronounced function exhibited in both Sulcia and the cicada bacteriomes in newly emerged adults. The results suggest host sensing of arginine and leucine integrate Sulcia's output of host-EAAs into mTORC1 signaling. This study highlights the importance of signaling pathways in regulating the host/symbiont interaction and symbiont transmission in sap-feeding auchenorrhynchous insects. This article is protected by copyright. All rights reserved.}, }
@article {pmid36510006, year = {2022}, author = {Elder, H and Million, WC and Bartels, E and Krediet, CJ and Muller, EM and Kenkel, CD}, title = {Long-term maintenance of a heterologous symbiont association in Acropora palmata on natural reefs.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {36510006}, issn = {1751-7370}, abstract = {The sensitivity of reef-building coral to elevated temperature is a function of their symbiosis with dinoflagellate algae in the family Symbiodiniaceae. Changes in the composition of the endosymbiont community in response to thermal stress can increase coral thermal tolerance. Consequently, this mechanism is being investigated as a human-assisted intervention for rapid acclimation of coral in the face of climate change. Successful establishment of novel symbioses that increase coral thermal tolerance have been demonstrated in laboratory conditions; however, it is unclear how long these heterologous relationships persist in nature. Here, we test the persistence of a novel symbiosis between Acropora palmata and Durusdinium spp. from Mote Marine Laboratory's ex situ nursery by outplanting clonal replicates (ramets) of five A. palmata host genotypes to natural reefs in the lower Florida Keys. Amplicon sequencing analysis of ITS2-type profiles revealed that the majority of surviving ramets remained dominated by Durusdinium spp. two years after transplantation. However, 15% of ramets, including representatives of all genotypes, exhibited some degree of symbiont shuffling or switching at six of eight sites, including complete takeover by site-specific strains of the native symbiont, Symbiodinium fitti. The predominant long-term stability of the novel symbiosis supports the potential effectiveness of symbiont modification as a management tool. Although, the finding that 6-7 year-old coral can alter symbiont community composition in the absence of bleaching indicates that Symbiodiniaceae communities are indeed capable of great flexibility under ambient conditions.}, }
@article {pmid36505058, year = {2022}, author = {Alarcón, ME and Polo, PG and Akyüz, SN and Rafiqi, AM}, title = {Evolution and ontogeny of bacteriocytes in insects.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {1034066}, pmid = {36505058}, issn = {1664-042X}, abstract = {The ontogenetic origins of the bacteriocytes, which are cells that harbour bacterial intracellular endosymbionts in multicellular animals, are unknown. During embryonic development, a series of morphological and transcriptional changes determine the fate of distinct cell types. The ontogeny of bacteriocytes is intimately linked with the evolutionary transition of endosymbionts from an extracellular to an intracellular environment, which in turn is linked to the diet of the host insect. Here we review the evolution and development of bacteriocytes in insects. We first classify the endosymbiotic occupants of bacteriocytes, highlighting the complex challenges they pose to the host. Then, we recall the historical account of the discovery of bacteriocytes. We then summarize the molecular interactions between the endosymbiont and the host. In addition, we illustrate the genetic contexts in which the bacteriocytes develop, with examples of the genetic changes in the hosts and endosymbionts, during specific endosymbiotic associations. We finally address the evolutionary origin as well as the putative ontogenetic or developmental source of bacteriocytes in insects.}, }
@article {pmid36504780, year = {2022}, author = {Li, T and Wei, Y and Zhao, C and Li, S and Gao, S and Zhang, Y and Wu, Y and Lu, C}, title = {Facultative symbionts are potential agents of symbiont-mediated RNAi in aphids.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1020461}, pmid = {36504780}, issn = {1664-302X}, abstract = {Aphids are major crop pests, and they can be controlled through the application of the promising RNA interference (RNAi) techniques. However, chemical synthesis yield of dsRNA for RNAi is low and costly. Another sustainable aphid pest control strategy takes advantage of symbiont-mediated RNAi (SMR), which can generate dsRNA by engineered microbes. Aphid host the obligate endosymbiont Buchnera aphidicola and various facultative symbionts that not only have a wide host range but are also vertically and horizontally transmitted. Thus, we described the potential of facultative symbionts in aphid pest control by SMR. We summarized the community and host range of these facultative symbionts, and then reviewed their probable horizontal transmitted routes and ecological functions. Moreover, recent advances in the cultivation and genetic engineering of aphid facultative symbionts were discussed. In addition, current legislation of dsRNA-based pest control strategies and their safety assessments were reviewed.}, }
@article {pmid36504779, year = {2022}, author = {Liberman, R and Benayahu, Y and Huchon, D}, title = {Octocorals in the Gulf of Aqaba exhibit high photosymbiont fidelity.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1005471}, pmid = {36504779}, issn = {1664-302X}, abstract = {Symbiotic associations, widespread in terrestrial and marine ecosystems, are of considerable ecological importance. Many tropical coral species are holobionts, formed by the obligate association between a cnidarian host and endosymbiotic dinoflagellates of the family Symbiodiniaceae. The latter are abundant on coral reefs from very shallow water down to the upper mesophotic zone (30-70 m). The research on scleractinians has revealed that the photosymbiont lineages present in the cnidarian host play an important role in the coral's ability to thrive under different environmental conditions, such as light regime and temperature. However, little is known regarding octocoral photosymbionts, and in particular regarding those found deeper than 30 m. Here, we used ribosomal (ITS2) and chloroplast (23S) markers to uncover, for the first time, the dominant Symbiodiniaceae taxa present in 19 mesophotic octocoral species (30-70 m depth) from the Gulf of Aqaba/Eilat (northern Red Sea). In addition, using high-throughput sequencing of the ITS2 region we characterized both the dominant and the rare Symbiodiniaceae lineages found in several species across depth. The phylogenetic analyses of both markers were in agreement and revealed that most of the studied mesophotic octocorals host the genus Cladocopium. Litophyton spp. and Klyxum utinomii were exceptions, as they harbored Symbiodinium and Durusdinium photosymbionts, respectively. While the dominant algal lineage of each coral species did not vary across depth, the endosymbiont community structure significantly differed between host species, as well as between different depths for some host species. The findings from this study contribute to the growing global-catalogue of Cnidaria-Symbiodiniaceae associations. Unravelling the Symbiodiniaceae composition in octocoral holobionts across environmental gradients, depth in particular, may enable a better understanding of how specialized those associations are, and to what extent coral holobionts are able to modify their photosymbionts.}, }
@article {pmid36502993, year = {2022}, author = {V Venkataravanappa,  and Kodandaram, MH and Prasanna, HC and Reddy, MK and Reddy, CNL}, title = {Unraveling different begomoviruses, DNA satellites and cryptic species of Bemisia tabaci and their endosymbionts in vegetable ecosystem.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {105892}, doi = {10.1016/j.micpath.2022.105892}, pmid = {36502993}, issn = {1096-1208}, abstract = {Bemisia tabaci species complex contains more than 46 cryptic species. It has emerged as an important pest causing significant yield loss in many cultivated crops. This pest is also a vector for more than 100 species of begomoviruses, that are a major threat for the cultivation of many crops in different regions of the world. The relation between cryptic species of the B. tabaci species complex and associated begomoviruses that infect different crops remains unclear. In the present study, four cryptic species (Asia I, China 3, Asia II 5 and Asia II-1) of B. tabaci and four associated endosymbionts (Arsenophonus, Cardinium, Rickettsia and Wolbachia) were identified in different vegetable crops. The vector-based PCR detection revealed five different begomoviruses such as okra enation leaf curl virus (OELCuV), tomato leaf curl Palampur virus (ToLCPalV), squash leaf curl China virus (SLCCNV), chilli leaf curl virus (ChiLCuV), and tomato leaf curl New Delhi virus (ToLCNDV). Of these begomoviruses, the maximum infection rate was observed (9.1%) for OELCuV, followed by 7.3% for ToLCNDV. The infection rate of the other three viruses (SLCCNV, ChiLCuV, ToLCPalV) ranged from 0.9 to 2.7% in cryptic species of B. tabaci. Further, each cryptic species was infected with multiple virus species and the virus infection rate of Asia I, Asia II-5, China 3 and Asia II-1 was 21.2%, 15.1%, 15.1% and 0.6% respectively. Similarly, in case of betasatellites the highest infection rate was 12% for ToLCBDB, followed by 6% for OLCuB and PaLCB. With regard to alphasatellites, the highest infection rate was 18.2% for AEV and 3% for CLCuMuA. This study demonstrates the distribution of cryptic species of whitefly and their endosymbionts, and associated begomoviruses and DNA satellites in vegetable ecosystem. We believe that the information generated here is useful for evolving an effective pest management strategies for vegetable production.}, }
@article {pmid36501390, year = {2022}, author = {Yu, W and Bosquée, E and Fan, J and Liu, Y and Bragard, C and Francis, F and Chen, J}, title = {Proteomic and Transcriptomic Analysis for Identification of Endosymbiotic Bacteria Associated with BYDV Transmission Efficiency by Sitobion miscanthi.}, journal = {Plants (Basel, Switzerland)}, volume = {11}, number = {23}, pages = {}, doi = {10.3390/plants11233352}, pmid = {36501390}, issn = {2223-7747}, abstract = {Sitobion miscanthi, an important viral vector of barley yellow dwarf virus (BYDV), is also symbiotically associated with endosymbionts, but little is known about the interactions between endosymbionts, aphid and BYDV. Therefore, two aphids' geographic populations, differing in their BYDV transmission efficiency, after characterizing their endosymbionts, were treated with antibiotics to investigate how changes in the composition of their endosymbiont population affected BYDV transmission efficiency. After antibiotic treatment, Rickettsia was eliminated from two geographic populations. BYDV transmission efficiency by STY geographic population dropped significantly, by -44.2% with ampicillin and -25.01% with rifampicin, but HDZ geographic population decreased by only 14.19% with ampicillin and 23.88% with rifampicin. Transcriptomic analysis showed that the number of DEGs related to the immune system, carbohydrate metabolism and lipid metabolism did increase in the STY rifampicin treatment, while replication and repair, glycan biosynthesis and metabolism increased in the STY ampicillin treatment. Proteomic analysis showed that the abundance of symbionin symL, nascent polypeptide-associated complex subunit alpha and proteasome differed significantly between the two geographic populations. We found that the endosymbionts can mediate vector viral transmission. They should therefore be included in investigations into aphid-virus interactions and plant disease epidemiology. Our findings should also help with the development of strategies to prevent virus transmission.}, }
@article {pmid36480982, year = {2022}, author = {Morales, J and Ehret, G and Poschmann, G and Reinicke, T and Maurya, AK and Kröninger, L and Zanini, D and Wolters, R and Kalyanaraman, D and Krakovka, M and Bäumers, M and Stühler, K and Nowack, ECM}, title = {Host-symbiont interactions in Angomonas deanei include the evolution of a host-derived dynamin ring around the endosymbiont division site.}, journal = {Current biology : CB}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.cub.2022.11.020}, pmid = {36480982}, issn = {1879-0445}, abstract = {The trypanosomatid Angomonas deanei is a model to study endosymbiosis. Each cell contains a single β-proteobacterial endosymbiont that divides at a defined point in the host cell cycle and contributes essential metabolites to the host metabolism. Additionally, one endosymbiont gene, encoding an ornithine cyclodeaminase (OCD), was transferred by endosymbiotic gene transfer (EGT) to the nucleus. However, the molecular mechanisms mediating the intricate host/symbiont interactions are largely unexplored. Here, we used protein mass spectrometry to identify nucleus-encoded proteins that co-purify with the endosymbiont. Expression of fluorescent fusion constructs of these proteins in A. deanei confirmed seven host proteins to be recruited to specific sites within the endosymbiont. These endosymbiont-targeted proteins (ETPs) include two proteins annotated as dynamin-like protein and peptidoglycan hydrolase that form a ring-shaped structure around the endosymbiont division site that remarkably resembles organellar division machineries. The EGT-derived OCD was not among the ETPs, but instead localizes to the glycosome, likely enabling proline production in the glycosome. We hypothesize that recalibration of the metabolic capacity of the glycosomes that are closely associated with the endosymbiont helps to supply the endosymbiont with metabolites it is auxotrophic for and thus supports the integration of host and endosymbiont metabolic networks. Hence, scrutiny of endosymbiosis-induced protein re-localization patterns in A. deanei yielded profound insights into how an endosymbiotic relationship can stabilize and deepen over time far beyond the level of metabolite exchange.}, }
@article {pmid36478675, year = {2022}, author = {Adegoke, A and Kumar, D and Budachetri, K and Karim, S}, title = {Hematophagy and tick-borne Rickettsial pathogen shape the microbial community structure and predicted functions within the tick vector, Amblyomma maculatum.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {1037387}, doi = {10.3389/fcimb.2022.1037387}, pmid = {36478675}, issn = {2235-2988}, abstract = {BACKGROUND: Ticks are the primary vectors of emerging and resurging pathogens of public health significance worldwide. Analyzing tick bacterial composition, diversity, and functionality across developmental stages and tissues is crucial for designing new strategies to control ticks and prevent tick-borne diseases.<br><br>MATERIALS AND METHODS: Here, we explored the microbial communities across the developmental timeline and in different tissues of the Gulf-Coast ticks (Amblyomma maculatum). Using a high-throughput sequencing approach, the influence of blood meal and Rickettsia parkeri, a spotted fever group rickettsiae infection in driving changes in microbiome composition, diversity, and functionality was determined.<br><br>RESULTS: This study shows that the core microbiome of Am. maculatum comprises ten core bacterial genera. The genus Rickettsia, Francisella, and Candidatus_Midichloria are the key players, with positive interactions within each developmental stage and adult tick organ tested. Blood meal and Rickettsia parkeri led to an increase in the bacterial abundance in the tissues. According to functional analysis, the increase in bacterial numbers is positively correlated to highly abundant energy metabolism orthologs with blood meal. Correlation analysis identified an increase in OTUs identified as Candidatus Midichloria and a subsequent decrease in Francisella OTUs in Rickettsia parkeri infected tick stages and tissues. Results demonstrate the abundance of Rickettsia and Francisella predominate in the core microbiome of Am. maculatum, whereas Candidatus_Midichloria and Cutibacterium prevalence increase with R. parkeri-infection. Network analysis and functional annotation suggest that R. parkeri interacts positively with Candidatus_Midichloria and negatively with Francisella.<br><br>CONCLUSION: We conclude that tick-transmitted pathogens, such as R. parkeri establishes infection by interacting with the core microbiome of the tick vector.}, }
@article {pmid36473013, year = {2022}, author = {Liu, L and Sonenshine, DE and Sultana, H and Neelakanta, G}, title = {Identification of a rickettsial endosymbiont in a soft tick Ornithodoros turicata americanus.}, journal = {PloS one}, volume = {17}, number = {12}, pages = {e0278582}, doi = {10.1371/journal.pone.0278582}, pmid = {36473013}, issn = {1932-6203}, abstract = {Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis, a rickettsial endosymbiont, was first identified in the soft tick Ornithodoros sonrai collected from Senegal and later was identified in a hard tick Africaniella transversale. In this study, we noted the presence of Occidentia species, designated as Occidentia-like species, in a soft tick O. turicata americanus. Sequencing and phylogenetic analyses of the two genetic markers, 16S rRNA and groEL confirmed the presence of Occidentia-like species in O. turicata americanus ticks. The Occidentia-like species was noted to be present in all developmental stages of O. turicata americanus and in different tick tissues including ovaries, synganglion, guts and salivary gland. The levels of Occidentia-like species 16S rRNA transcripts were noted to be significantly higher in ovaries than in a gut tissue. In addition, Occidentia-like species groEL expression was noted to be significantly higher in tick synganglion than in ovaries and gut tissues. Furthermore, levels of Occidentia-like species 16S rRNA transcripts increased significantly upon O. turicata americanus blood feeding. Taken together, our study not only shows that Occidentia-like species is present in O. turicata americanus but also suggests that this bacterium may play a role in tick-bacteria interactions.}, }
@article {pmid36472572, year = {2022}, author = {Pilgrim, J}, title = {The opportunities of research parasitism: A case study using the Barcode of Life Data System (BOLD).}, journal = {GigaScience}, volume = {11}, number = {}, pages = {}, doi = {10.1093/gigascience/giac123}, pmid = {36472572}, issn = {2047-217X}, abstract = {The Barcode of Life Data System (BOLD) is primarily used to identify biological specimens based on a mitochondrial gene sequence and has been an underpinning resource for life science researchers. Importantly, curators of BOLD archive DNA extracts where possible, and also record contaminant sequences that can be made available on request. This collegial offering of samples and data led to our work describing the serendipitous discovery of new interactions between a Torix Rickettsia bacterium and their arthropod hosts and resulted in winning the 2022 Junior Research Parasite Award. A case study of this work is presented, which discusses the opportunities provided by secondary data and how careful maintenance of such large-scale repositories plays a vital role in scientific research that goes beyond obvious lines of enquiry.}, }
@article {pmid36467722, year = {2022}, author = {Hodosi, R and Kazimirova, M and Soltys, K}, title = {What do we know about the microbiome of I. ricinus?.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {990889}, pmid = {36467722}, issn = {2235-2988}, mesh = {Animals ; *Ixodes ; *Microbiota ; Coxiella ; Symbiosis ; *Rickettsia ; *Francisella tularensis ; }, abstract = {I. ricinus is an obligate hematophagous parasitic arthropod that is responsible for the transmission of a wide range of zoonotic pathogens including spirochetes of the genus Borrelia, Rickettsia spp., C. burnetii, Anaplasma phagocytophilum and Francisella tularensis, which are part the tick´s microbiome. Most of the studies focus on "pathogens" and only very few elucidate the role of "non-pathogenic" symbiotic microorganisms in I. ricinus. While most of the members of the microbiome are leading an intracellular lifestyle, they are able to complement tick´s nutrition and stress response having a great impact on tick´s survival and transmission of pathogens. The composition of the tick´s microbiome is not consistent and can be tied to the environment, tick species, developmental stage, or specific organ or tissue. Ovarian tissue harbors a stable microbiome consisting mainly but not exclusively of endosymbiotic bacteria, while the microbiome of the digestive system is rather unstable, and together with salivary glands, is mostly comprised of pathogens. The most prevalent endosymbionts found in ticks are Rickettsia spp., Ricketsiella spp., Coxiella-like and Francisella-like endosymbionts, Spiroplasma spp. and Candidatus Midichloria spp. Since microorganisms can modify ticks' behavior, such as mobility, feeding or saliva production, which results in increased survival rates, we aimed to elucidate the potential, tight relationship, and interaction between bacteria of the I. ricinus microbiome. Here we show that endosymbionts including Coxiella-like spp., can provide I. ricinus with different types of vitamin B (B2, B6, B7, B9) essential for eukaryotic organisms. Furthermore, we hypothesize that survival of Wolbachia spp., or the bacterial pathogen A. phagocytophilum can be supported by the tick itself since coinfection with symbiotic Spiroplasma ixodetis provides I. ricinus with complete metabolic pathway of folate biosynthesis necessary for DNA synthesis and cell division. Manipulation of tick´s endosymbiotic microbiome could present a perspective way of I. ricinus control and regulation of spread of emerging bacterial pathogens.}, }
@article {pmid36466669, year = {2022}, author = {El Hamss, H and Maruthi, MN and Ally, HM and Omongo, CA and Wang, HL and van Brunschot, S and Colvin, J and Delatte, H}, title = {Spatio-temporal changes in endosymbiont diversity and composition in the African cassava whitefly, Bemisia tabaci SSA1.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {986226}, pmid = {36466669}, issn = {1664-302X}, abstract = {Sap-sucking insects, including whiteflies, are amongst the most devastating and widely distributed organisms on the planet. They are often highly invasive and endosymbiont communities within these insects help them adapt to new or changing environments. Bemisia tabaci (Gennadius; Hemiptera: Aleyrodidae) whitefly species are vectors of more than 500 known plant-viruses and harbour highly diverse endosymbionts communities. To date, however, whitefly-endosymbiont interactions, community structure and their spatio-temporal changes are still poorly understood. In this study, we investigated the spatio-temporal changes in the composition and diversity of bacterial endosymbionts in the agricultural crop pest whitefly species, Bemisia tabaci sub-Saharan Africa 1-subgroup 1 and 2 (SSA1-SG1 and SSA1-SG2). 16S rRNA amplicon sequencing analysis was carried out to characterise endosymbiont compositionsin field-collected SSA1 (SSA1-SG1 and SSA1-SG2) populations infesting cassava in Uganda in 1997 and 2017. We detected Portiera, Arsenophonus, Wolbachia, Hamiltonella and Hemipteriphilus, with Arsenophonus and Wolbachia infections being predominant. Hemipteriphilus and Hamiltonella frequencies were very low and were detected in seven and two samples, respectively. Bacterial diversity based on three independent parameters including Simpson index, number of haplotypes and Bray-Curtis dissimilarity matrix was significantly higher in 1997 than in 2017. This period also coincided with the advent of super-abundant cassava-whitefly populations on cassava crops in Uganda. We discuss how endosymbionts may influence the biology and behaviour of whiteflies leading to population explosions.}, }
@article {pmid36458425, year = {2022}, author = {Higashi, CHV and Nichols, WL and Chevignon, G and Patel, V and Allison, SE and Kim, KL and Strand, MR and Oliver, KM}, title = {An aphid symbiont confers protection against a specialized RNA virus, another increases vulnerability to the same pathogen.}, journal = {Molecular ecology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mec.16801}, pmid = {36458425}, issn = {1365-294X}, abstract = {Insects often harbor heritable symbionts that provide defense against specialized natural enemies, yet little is known about symbiont protection when hosts face simultaneous threats. In pea aphids (Acyrthosiphon pisum), the facultative endosymbiont Hamiltonella defensa confers protection against the parasitoid, Aphidius ervi, and Regiella insecticola protects against aphid-specific fungal pathogens, including Pandora neoaphidis. Here we investigated whether these two common aphid symbionts protect against a specialized virus A. pisum virus (APV), and whether their anti-fungal and anti-parasitoid services are impacted by APV infection. We found that APV imposed large fitness costs on symbiont-free aphids and these costs were elevated in aphids also housing H. defensa. In contrast, APV titers were significantly reduced and costs to APV infection were largely eliminated in aphids with R. insecticola. To our knowledge, R. insecticola is the first aphid symbiont shown to protect against a viral pathogen, and only the second arthropod symbiont reported to do so. In contrast, APV infection did not impact the protective services of either R. insecticola or H. defensa. To better understand APV biology, we produced five genomes and examined transmission routes. We found that moderate rates of vertical transmission, combined with horizontal transfer through food plants, were the major route of APV spread, although lateral transfer by parasitoids also occurred. Transmission was unaffected by facultative symbionts. In summary, the presence and species identity of facultative symbionts resulted in highly divergent outcomes for aphids infected with APV, while not impacting defensive services that target other enemies. These findings add to the diverse phenotypes conferred by aphid symbionts, and to the growing body of work highlighting extensive variation in symbiont-mediated interactions.}, }
@article {pmid36456664, year = {2022}, author = {Milenovic, M and Gouttepifre, A and Eickermann, M and Junk, J and Rapisarda, C}, title = {Plant-mediated rifampicin treatment of Bemisia tabaci disrupts but does not eliminate endosymbionts.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {20766}, pmid = {36456664}, issn = {2045-2322}, mesh = {Animals ; Rifampin/pharmacology ; *Halomonadaceae ; Anti-Bacterial Agents/pharmacology ; *Rickettsia ; *Hemiptera ; }, abstract = {Whiteflies are among the most important global insect pests in agriculture; their sustainable control has proven challenging and new methods are needed. Bacterial symbionts of whiteflies are poorly understood potential target of novel whitefly control methods. Whiteflies harbour an obligatory bacterium, Candidatus Portiera aleyrodidarum, and a diverse set of facultative bacterial endosymbionts. Function of facultative microbial community is poorly understood largely due to the difficulty in their selective elimination without removal of the primary endosymbiont. Since the discovery of secondary endosymbionts, antibiotic rifampicin has emerged as the most used tool for their manipulation. Its effectiveness is however much less clear, with contrasting reports on its effects on the endosymbiont community. The present study builds upon most recent method of rifampicin application in whiteflies and evaluates its ability to eliminate obligatory Portiera and two facultative endosymbionts (Rickettsia and Arsenophnus). Our results show that rifampicin reduces but does not eliminate any of the three endosymbionts. Additionally, rifampicin causes direct negative effect on whiteflies, likely by disrupting mitochondria. Taken together, results signify the end of a rifampicin era in whitefly endosymbiont studies. Finally, we propose refinement of current quantification and data analysis methods which yields additional insights in cellular metabolic scaling.}, }
@article {pmid36447246, year = {2022}, author = {Dieng, MM and Augustinos, AA and Demirbas-Uzel, G and Doudoumis, V and Parker, AG and Tsiamis, G and Mach, RL and Bourtzis, K and Abd-Alla, AMM}, title = {Interactions between Glossina pallidipes salivary gland hypertrophy virus and tsetse endosymbionts in wild tsetse populations.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {447}, pmid = {36447246}, issn = {1756-3305}, mesh = {Animals ; Cytomegalovirus ; *Tsetse Flies ; *Coinfection ; *Glossinidae ; Hypertrophy ; *Infertility ; Salivary Glands ; }, abstract = {BACKGROUND: Tsetse control is considered an effective and sustainable tactic for the control of cyclically transmitted trypanosomosis in the absence of effective vaccines and inexpensive, effective drugs. The sterile insect technique (SIT) is currently used to eliminate tsetse fly populations in an area-wide integrated pest management (AW-IPM) context in Senegal. For SIT, tsetse mass rearing is a major milestone that associated microbes can influence. Tsetse flies can be infected with microorganisms, including the primary and obligate Wigglesworthia glossinidia, the commensal Sodalis glossinidius, and Wolbachia pipientis. In addition, tsetse populations often carry a pathogenic DNA virus, the Glossina pallidipes salivary gland hypertrophy virus (GpSGHV) that hinders tsetse fertility and fecundity. Interactions between symbionts and pathogens might affect the performance of the insect host.<br><br>METHODS: In the present study, we assessed associations of GpSGHV and tsetse endosymbionts under field conditions to decipher the possible bidirectional interactions in different Glossina species. We determined the co-infection pattern of GpSGHV and Wolbachia in natural tsetse populations. We further analyzed the interaction of both Wolbachia and GpSGHV infections with Sodalis and Wigglesworthia density using qPCR.<br><br>RESULTS: The results indicated that the co-infection of GpSGHV and Wolbachia was most prevalent in Glossina austeni and Glossina morsitans morsitans, with an explicit significant negative correlation between GpSGHV and Wigglesworthia density. GpSGHV infection levels > 10[3.31] seem to be absent when Wolbachia infection is present at high density (>&#x2009;10[7.36]), suggesting a potential protective role of Wolbachia against GpSGHV.<br><br>CONCLUSION: The result indicates that Wolbachia infection might interact (with an undefined mechanism) antagonistically with SGHV infection protecting tsetse fly against GpSGHV, and the interactions between the tsetse host and its associated microbes are dynamic and likely species specific; significant differences may exist between laboratory and field conditions.}, }
@article {pmid36445499, year = {2022}, author = {Ramirez, P and Leavitt, JC and Gill, JJ and Mateos, M}, title = {Preliminary Characterization of Phage-Like Particles from the Male-Killing Mollicute Spiroplasma poulsonii (an Endosymbiont of Drosophila).}, journal = {Current microbiology}, volume = {80}, number = {1}, pages = {6}, pmid = {36445499}, issn = {1432-0991}, mesh = {Male ; Animals ; Drosophila ; *Bacteriophages/genetics ; Drosophila melanogaster ; *Spiroplasma/genetics ; }, abstract = {Bacteriophages are vastly abundant, diverse, and influential, but with few exceptions (e.g. the Proteobacteria genera Wolbachia and Hamiltonella), the role of phages in heritable bacteria-arthropod interactions, which are ubiquitous and diverse, remains largely unexplored. Despite prior studies documenting phage-like particles in the mollicute Spiroplasma associated with Drosophila flies, genomic sequences of such phage are lacking, and their effects on the Spiroplasma-Drosophila interaction have not been comprehensively characterized. We used a density step gradient to isolate phage-like particles from the male-killing bacterium Spiroplasma poulsonii (strains NSRO and MSRO-Br) harbored by Drosophila melanogaster. Isolated particles were subjected to DNA sequencing, assembly, and annotation. Several lines of evidence suggest that we recovered phage-like particles of similar features (shape, size, DNA content) to those previously reported in Drosophila-associated Spiroplasma strains. We recovered three ~ 19 kb phage-like contigs (two in NSRO and one in MSRO-Br) containing 21-24 open reading frames, a read-alignment pattern consistent with circular permutation, and terminal redundancy (at least in NSRO). Although our results do not allow us to distinguish whether these phage-like contigs represent infective phage-like particles capable of transmitting their DNA to new hosts, their encoding of several typical phage genes suggests that they are at least remnants of functional phage. We also recovered two smaller non-phage-like contigs encoding a known Spiroplasma toxin (Ribosome Inactivating Protein; RIP), and an insertion element, suggesting that they are packaged into particles. Substantial homology of our particle-derived contigs was found in the genome assemblies of members of the Spiroplasma poulsonii clade.}, }
@article {pmid36445124, year = {2022}, author = {Kang, ZW and Zhang, M and Cao, HH and Guo, SS and Liu, FH and Liu, TX}, title = {Facultative Endosymbiont Serratia symbiotica Inhibits the Apterization of Pea Aphid To Enhance Its Spread.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0406622}, doi = {10.1128/spectrum.04066-22}, pmid = {36445124}, issn = {2165-0497}, abstract = {Aphids display wing polyphenism, and the mother can produce a wingless morph for reproduction and a winged morph for dispersal. It is believed that the wingless morph is an adaptive status under favorable conditions and is determined prenatally. In this study, we have found that winged nymphs of the pea aphid, Acyrthosiphon pisum, can change from winged to wingless during normal development. Our results showed that winged nymphs could become the wingless morph by apterization in response to changes from stressful to favorable conditions. The acquired wingless aphids had higher fecundity than the winged morph. However, this process of regression from winged to wingless morph was inhibited by Serratia symbiotica. The existence of the symbiont did not affect the body mass and fecundity of adult aphids, but it increased the body weight of nymphs and temporally increased the quantity of a primary symbiont, Buchnera aphidicola. Our results showed that despite temporal improvement of living conditions causing the induction of apterization of winged nymphs, the inhibition effect of S. symbiotica on this process was activated simultaneously. This finding, for the first time, reveals that the wingless morph can be changed postnatally, which explains a novel regulating mechanism of wing polyphenism driven by external abiotic stimuli and internal biotic regulation together in aphids. IMPORTANCE Wing polyphenism is an important adaptative response to environmental changes for aphids. Endosymbionts are widespread in aphids and also confer the ability to withstand unfavorable conditions. However, little is known about whether endosymbionts are involved in the wing polyphenism. In this study, we report a new finding that winged nymphs of the pea aphid could turn into adults without wings or wing-related structures through apterization when winged nymphs escaped from stressful to favorable environments. Further analysis revealed that the facultative symbiont S. symbiotica could prevent the temporal determination of the host in wing suppression by inhibiting apterization, to enhance its spread. Our findings provide a novel angle to understanding the wing polyphenism regulation of aphids.}, }
@article {pmid36441823, year = {2022}, author = {Runyen-Janecky, LJ and Scheutzow, JD and Farsin, R and Cabo, LF and Wall, KE and Kuhn, KM and Amador, R and D'Souza, SJ and Vigneron, A and Weiss, BL}, title = {Heme-induced genes facilitate endosymbiont (Sodalis glossinidius) colonization of the tsetse fly (Glossina morsitans) midgut.}, journal = {PLoS neglected tropical diseases}, volume = {16}, number = {11}, pages = {e0010833}, doi = {10.1371/journal.pntd.0010833}, pmid = {36441823}, issn = {1935-2735}, abstract = {Tsetse flies (Glossina spp.) feed exclusively on vertebrate blood. After a blood meal, the enteric endosymbiont Sodalis glossinidius is exposed to various environmental stressors including high levels of heme. To investigate how S. glossinidius morsitans (Sgm), the Sodalis subspecies that resides within the gut of G. morsitans) tolerates the heme-induced oxidative environment of tsetse's midgut, we used RNAseq to identify bacterial genes that are differentially expressed in cells cultured in high versus lower heme environments. Our analysis identified 436 genes that were significantly differentially expressed (> or < 2-fold) in the presence of high heme [219 heme-induced genes (HIGs) and 217 heme-repressed genes (HRGs)]. HIGs were enriched in Gene Ontology (GO) terms related to regulation of a variety of biological functions, including gene expression and metabolic processes. We observed that 11 out of 13 Sgm genes that were heme regulated in vitro were similarly regulated in bacteria that resided within tsetse's midgut 24 hr (high heme environment) and 96 hr (low heme environment) after the flies had consumed a blood meal. We used intron mutagenesis to make insertion mutations in 12 Sgm HIGs and observed no significant change in growth in vitro in any of the mutant strains in high versus low heme conditions. However, Sgm strains that carried mutations in genes encoding a putative undefined phosphotransferase sugar (PTS) system component (SG2427), fucose transporter (SG0182), bacterioferritin (SG2280), and a DNA-binding protein (SGP1-0002) presented growth and/or survival defects in tsetse midguts as compared to normal Sgm. These findings suggest that the uptake up of sugars and storage of iron represent strategies that Sgm employs to successfully reside within the high heme environment of its tsetse host's midgut. Our results are of epidemiological relevance, as many hematophagous arthropods house gut-associated bacteria that mediate their host's competency as a vector of disease-causing pathogens.}, }
@article {pmid36436891, year = {2022}, author = {Rialch, A and Sankar, M and Silamparasan, M and Madhusoodan, AP and Kharayat, NS and Gautam, S and Gurav, AR and Thankappan, S}, title = {Molecular detection of Coxiella-like endosymbionts in Rhipicephalus microplus from north India.}, journal = {Veterinary parasitology, regional studies and reports}, volume = {36}, number = {}, pages = {100803}, doi = {10.1016/j.vprsr.2022.100803}, pmid = {36436891}, issn = {2405-9390}, mesh = {Humans ; Female ; Animals ; Coxiella/genetics ; *Rhipicephalus/genetics ; RNA, Ribosomal, 16S/genetics ; Phylogeny ; Pilot Projects ; *Rickettsia/genetics ; *Francisella ; }, abstract = {Apart from the tick-borne pathogens affecting human and animal health, ticks also harbor various non-pathogenic endosymbionts with dynamic ecological interactions. These endosymbionts are unexplored from the Indian ticks; hence this pilot study was conducted. Seventy-nine ticks were collected from Nainital district of Uttarakhand state of north India and were identified as Rhipicephalus microplus morphologically and by molecular analysis. PCR and sequence analysis were carried out to detect the presence of Rickettsia-like, Coxiella-like and Francisella-like endosymbionts in these ticks. Based on the partial 16S rRNA gene sequence, Coxiella-like endosymbiont (CLE) was detected in the adult and other life-cycle stages of ticks with 96.6-97.7% nucleotide sequence identity with the published CLE sequences from GenBank. The phylogenetic analysis revealed that the CLE from R. microplus were clustered with the CLE from other Rhipicephalus species. All these CLE formed distinct clades from the pathogenic Coxiella burnetii. None of the tick samples was found positive for Rickettsia-like and Francisella-like endosymbionts in the present study. We also demonstrated the vertical transmission of CLE from surface sterilized and laboratory reared fully engorged adult females to the eggs and the larvae. However, large scale studies are to be conducted to detect various endosymbionts and endosymbiont-tick associations in the Indian tick species and to explore these associations for tick and tick-borne disease control.}, }
@article {pmid36429867, year = {2022}, author = {Chen, K and Roe, RM and Ponnusamy, L}, title = {Biology, Systematics, Microbiome, Pathogen Transmission and Control of Chiggers (Acari: Trombiculidae, Leeuwenhoekiidae) with Emphasis on the United States.}, journal = {International journal of environmental research and public health}, volume = {19}, number = {22}, pages = {}, doi = {10.3390/ijerph192215147}, pmid = {36429867}, issn = {1660-4601}, mesh = {Animals ; Humans ; *Trombiculidae/microbiology ; *Scrub Typhus/epidemiology ; *Orientia tsutsugamushi ; *Acari ; *Microbiota ; Biology ; }, abstract = {Chiggers are the larval stage of Trombiculidae and Leeuwenhoekiidae mites of medical and veterinary importance. Some species in the genus Leptotrombidium and Herpetacarus vector Orientia species, the bacteria that causes scrub typhus disease in humans. Scrub typhus is a life-threatening, febrile disease. Chigger bites can also cause dermatitis. There were 248 chigger species reported from the US from almost every state. However, there are large gaps in our knowledge of the life history of other stages of development. North American wide morphological keys are needed for better species identification, and molecular sequence data for identification are minimal and not clearly matched with morphological data. The role of chiggers in disease transmission in the US is especially understudied, and the role of endosymbionts in Orientia infection are suggested in the scientific literature but not confirmed. The most common chiggers in the eastern United States were identified as Eutrombicula alfreddugesi but were likely misidentified and should be replaced with Eutrombicula cinnabaris. Scrub typhus was originally believed to be limited to the Tsutsugamushi Triangle and the chigger genus, Leptotrombidium, but there is increasing evidence this is not the case. The potential of Orientia species establishing in the US is high. In addition, several other recognized pathogens to infect humans, namely Hantavirus, Bartonella, Borrelia, and Rickettsia, were also detected in chiggers. The role that chiggers play in these disease transmissions in the US needs further investigation. It is possible some of the tick-borne diseases and red meat allergies are caused by chiggers.}, }
@article {pmid36424352, year = {2022}, author = {Zhang, J and Li, T and Hong, Z and Ma, C and Fang, X and Zheng, F and Teng, W and Zhang, C and Si, T}, title = {Biosynthesis of Hybrid Neutral Lipids with Archaeal and Eukaryotic Characteristics in Engineered Saccharomyces cerevisiae.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {}, number = {}, pages = {}, doi = {10.1002/anie.202214344}, pmid = {36424352}, issn = {1521-3773}, abstract = {Discovery of the Asgard superphylum of archaea provides new evidence supporting the two-domain model of life: eukaryotes originated from an Asgard-related archaeon that engulfed a bacterial endosymbiont. However, how eukaryotes acquired bacterial-like membrane lipids with a sn-glycerol-3-phosphate (G3P) backbone instead of the archaeal-like sn-glycerol-1-phosphate (G1P) backbone remains unknown. Here we reconstituted archaeal lipid production in Saccharomyces cerevisiae by expressing unsaturated archaeol-synthesizing enzymes. Using Golden Gate cloning for pathway assembly, modular gene replacement was performed, revealing the potential biosynthesis of both G1P- and G3P-based unsaturated archaeol by uncultured Asgard archaea. Unexpectedly, hybrid neutral lipids containing both archaeal isoprenoids and eukaryotic fatty acids were observed in recombinant S. cerevisiae. The ability of yeast and archaeal diacylglycerol acyltransferases to synthesize such hybrid lipids was demonstrated.}, }
@article {pmid36422292, year = {2022}, author = {Villacorta, JB and Rodriguez, CV and Peran, JE and Batucan, JD and Concepcion, GP and Salvador-Reyes, LA and Junio, HA}, title = {Mining Small Molecules from Teredinibacter turnerae Strains Isolated from Philippine Teredinidae.}, journal = {Metabolites}, volume = {12}, number = {11}, pages = {}, pmid = {36422292}, issn = {2218-1989}, abstract = {Endosymbiotic relationship has played a significant role in the evolution of marine species, allowing for the development of biochemical machinery for the synthesis of diverse metabolites. In this work, we explore the chemical space of exogenous compounds from shipworm endosymbionts using LC-MS-based metabolomics. Priority T. turnerae strains (1022X.S.1B.7A, 991H.S.0A.06B, 1675L.S.0A.01) that displayed antimicrobial activity, isolated from shipworms collected from several sites in the Philippines were cultured, and fractionated extracts were subjected for profiling using ultrahigh-performance liquid chromatography with high-resolution mass spectrometry quadrupole time-of-flight mass analyzer (UHPLC-HRMS QTOF). T. turnerae T7901 was used as a reference microorganism for dereplication analysis. Tandem MS data were analyzed through the Global Natural Products Social (GNPS) molecular networking, which resulted to 93 clusters with more than two nodes, leading to four putatively annotated clusters: lipids, lysophosphatidylethanolamines, cyclic dipeptides, and rhamnolipids. Additional clusters were also annotated through molecular networking with cross-reference to previous publications. Tartrolon D cluster with analogues, turnercyclamycins A and B; teredinibactin A, dechloroteredinibactin, and two other possible teredinibactin analogues; and oxylipin (E)-11-oxooctadec-12-enoic acid were putatively identified as described. Molecular networking also revealed two additional metabolite clusters, annotated as lyso-ornithine lipids and polyethers. Manual fragmentation analysis corroborated the putative identification generated from GNPS. However, some of the clusters remained unclassified due to the limited structural information on marine natural products in the public database. The result of this study, nonetheless, showed the diversity in the chemical space occupied by shipworm endosymbionts. This study also affirms the use of bioinformatics, molecular networking, and fragmentation mechanisms analysis as tools for the dereplication of high-throughput data to aid the prioritization of strains for further analysis.}, }
@article {pmid36419550, year = {2022}, author = {Li, J and Chen, D and Yu, B and He, J and Huang, Z and Zheng, P and Mao, X and Li, H and Yu, J and Luo, J and Yan, H and Luo, Y}, title = {Batch and sampling time exert a larger influence on the fungal community than gastrointestinal location in model animals: A meaningful case study.}, journal = {Frontiers in nutrition}, volume = {9}, number = {}, pages = {1021215}, pmid = {36419550}, issn = {2296-861X}, abstract = {Fungi play a fundamental role in the intestinal ecosystem and health, but our knowledge of fungal composition and distribution in the whole gastrointestinal tract (GIT) is very limited. The physiological similarity between humans and pigs in terms of digestive and associated metabolic processes places, the pig in a superior position over other non-primate models. Here, we aimed to characterize the diversity and composition of fungi in the GIT of pigs. Using high-throughput sequencing, we evaluated the fungal community in different locations of GIT of 11 pigs with 128.41 ± 1.25 kg body weight acquired successively. Among them, five pigs are sacrificed in April 2019 (Batch 1) and the other six are sacrificed in January 2020 (Batch 2). All subjects with similar genetic backgrounds, housing, management, and diet. Finally, no significant difference is found in the α-diversity (Richness) of the fungal community among all intestinal segments. Basidiomycota and Ascomycota are the two predominant fungal phyla, but Batch 1 harbored a notably high abundance of Basidiomycota and Batch 2 harbored a high abundance of Ascomycota. Moreover, the two batches harbored completely different fungal compositions and core fungal genera. FUNGuild (Fungal Functional Guild) analysis revealed that most of the fungal species present in the GIT are saprotroph, plant pathogen, and animal endosymbiont. Our study is the first to report that even under the same condition, large variations in fungal composition in the host GIT still occur from batch-to-batch and sampling time. The implications of our observations serve as references to the development of better models of the human gut.}, }
@article {pmid36419378, year = {2023}, author = {Lin, YT and Xu, T and Ip, JC and Sun, Y and Fang, L and Luan, T and Zhang, Y and Qian, PY and Qiu, JW}, title = {Interactions among deep-sea mussels and their epibiotic and endosymbiotic chemoautotrophic bacteria: Insights from multi-omics analysis.}, journal = {Zoological research}, volume = {44}, number = {1}, pages = {106-125}, doi = {10.24272/j.issn.2095-8137.2022.279}, pmid = {36419378}, issn = {2095-8137}, mesh = {Animals ; *Ecosystem ; *Bivalvia/genetics ; Bacteria/genetics ; Symbiosis ; Carbon/metabolism ; }, abstract = {Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel (Gigantidas haimaensis) as a model, we explored this host-bacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing (SOX) multienzyme complex with the acquisition of soxB from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham (CBB) cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway (RuMP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine, isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.}, }
@article {pmid36417831, year = {2022}, author = {Power, RI and Šlapeta, J}, title = {Exploration of the sensitivity to macrocyclic lactones in the canine heartworm (Dirofilaria immitis) in Australia using phenotypic and genotypic approaches.}, journal = {International journal for parasitology. Drugs and drug resistance}, volume = {20}, number = {}, pages = {145-158}, doi = {10.1016/j.ijpddr.2022.11.003}, pmid = {36417831}, issn = {2211-3207}, abstract = {Canine heartworm disease is a potentially deadly cardiopulmonary disease caused by the mosquito-borne filarial nematode Dirofilaria immitis. In Australia, the administration of macrocyclic lactone (ML) drugs has successfully reduced the prevalence of D. immitis infection. However, the recent re-emergence of D. immitis in dogs in Queensland, Australia and the identification of ML-resistant isolates in the USA poses an important question of whether ML-resistance has emerged in this parasite in Australia. The aim of this study was to utilise phenotypic and genotypic approaches to examine the sensitivity to ML drugs in D. immitis in Australia. To do this, we surveyed 45 dogs from Queensland and New South Wales across 3 years (2019-2022) for the presence of D. immitis infection using an antigen test, quantitative Modified Knott's test, and qPCR targeting both D. immitis and the D. immitis symbiont Wolbachia. A phenotype observed by utilising sequential quantification of microfilariae for 23/45 dogs was coupled with genetic testing of filtered microfilariae for SNPs previously associated with ML-resistance in isolates from the USA. Sixteen (16/45) dogs tested positive for D. immitis infection despite reportedly receiving 'rigorous' heartworm prevention for 12 months prior to the study, according to the owners' assessment. The phenotype and genotypic assays in this study did not unequivocally demonstrate the presence of ML-resistant D. immitis in Australia. Although the failure of 16 dogs to reduce microfilaremia by >90% after ML treatment was considered a suspect phenotype of ML-resistance, no genotypic evidence was discovered using the genetic SNP analysis. The traditional quantitative Modified Knott's test can be substituted by qPCR targeting D. immitis or associated Wolbachia endosymbiont DNA for a more rapid measurement of microfilariae levels. More definitive phenotypic evidence of resistance is critically needed before the usefulness of SNPs for the detection of ML-resistance in Australia can be properly assessed.}, }
@article {pmid36412071, year = {2022}, author = {Shimpi, GG and Bentlage, B}, title = {Ancient endosymbiont-mediated transmission of a selfish gene provides a model for overcoming barriers to gene transfer into animal mitochondrial genomes.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {}, number = {}, pages = {e2200190}, doi = {10.1002/bies.202200190}, pmid = {36412071}, issn = {1521-1878}, abstract = {In contrast to bilaterian animals, non-bilaterian mitochondrial genomes contain atypical genes, often attributed to horizontal gene transfer (HGT) as an ad hoc explanation. Although prevalent in plants, HGT into animal mitochondrial genomes is rare, lacking suitable explanatory models for their occurrence. HGT of the mismatch DNA repair gene (mtMutS) from giant viruses to octocoral (soft corals and their kin) mitochondrial genomes provides a model for how barriers to HGT to animal mitochondria may be overcome. A review of the available literature suggests that this HGT was mediated by an alveolate endosymbiont infected with a lysogenic phycodnavirus that enabled insertion of the homing endonuclease containing mtMutS into octocoral mitochondrial genomes. We posit that homing endonuclease domains and similar selfish elements play a crucial role in such inter-domain gene transfers. Understanding the role of selfish genetic elements in HGT has the potential to aid development of tools for manipulating animal mitochondrial DNA.}, }
@article {pmid36407602, year = {2022}, author = {An, Y and Wang, Y and Wang, X and Xiao, J}, title = {Development of chloroplast transformation and gene expression regulation technology in land plants.}, journal = {Frontiers in plant science}, volume = {13}, number = {}, pages = {1037038}, pmid = {36407602}, issn = {1664-462X}, abstract = {Chloroplasts in land plants have their own small circular DNA that is presumed to have originated from cyanobacteria-related endosymbionts, and the chloroplast genome is an attractive target to improve photosynthetic ability and crop yield. However, to date, most transgenic or genetic engineering technologies for plants are restricted to manipulations of the nuclear genome. In this review, we provide a comprehensive overview of chloroplast genetic engineering and regulation of gene expression from the perspective of history and biology, focusing on current and latest methods. In addition, we suggest techniques that may regulate the chloroplast gene expression at the transcriptional or post-transcriptional level.}, }
@article {pmid36404929, year = {2022}, author = {Yorimoto, S and Hattori, M and Kondo, M and Shigenobu, S}, title = {Complex host/symbiont integration of a multi-partner symbiotic system in the eusocial aphid Ceratovacuna japonica.}, journal = {iScience}, volume = {25}, number = {12}, pages = {105478}, pmid = {36404929}, issn = {2589-0042}, abstract = {Some hemipteran insects rely on multiple endosymbionts for essential nutrients. However, the evolution of multi-partner symbiotic systems is not well-established. Here, we report a co-obligate symbiosis in the eusocial aphid, Ceratovacuna japonica. 16S rRNA amplicon sequencing unveiled co-infection with a novel Arsenophonus sp. symbiont and Buchnera aphidicola, a common obligate endosymbiont in aphids. Both symbionts were housed within distinct bacteriocytes and were maternally transmitted. The Buchnera and Arsenophonus symbionts had streamlined genomes of 432,286 bp and 853,149 bp, respectively, and exhibited metabolic complementarity in riboflavin and peptidoglycan synthesis pathways. These anatomical and genomic properties were similar to those of independently evolved multi-partner symbiotic systems, such as Buchnera-Serratia in Lachninae and Periphyllus aphids, representing remarkable parallelism. Furthermore, symbiont populations and bacteriome morphology differed between reproductive and soldier castes. Our study provides the first example of co-obligate symbiosis in Hormaphidinae and gives insight into the evolutionary genetics of this complex system.}, }
@article {pmid36389419, year = {2022}, author = {Wang, P and Ding, L and Li, F and Liao, J and Wang, M}, title = {Herbivore camping reshapes the taxonomy, function and network of pasture soil microbial communities.}, journal = {PeerJ}, volume = {10}, number = {}, pages = {e14314}, pmid = {36389419}, issn = {2167-8359}, abstract = {Although the effects of herbivore camping on soil physicochemical properties have been studied, whether the effects alter the soil microbial communities (e.g., composition, functions, taxonomic and functional diversities, network) remain unknown, especially below the surface. Here, using paired subsoil samples from half month-camping and non-camping, we showed for the first time that camping significantly changed the relative abundance of 21 bacterial phylotypes and five fungal phylotypes. Specifically, we observed significant increases in the relative abundance of putative chitinase and terpenes vanillin-decomposition genes, nitrite reduction function (nirB, nasA), decreases in the relative abundance of putative carbon fixation genes (ackA, PGK, and Pak), starch-decomposition gene (dexB), gene coding nitrogenase (anfG), and tetracycline resistance gene (tetB) for bacterial communities, and significant decreases in the relative abundance of animal endosymbiont and increases in the relative abundance of litter saprotroph and endophyte for fungal communities. However, camping did not significantly impact the taxonomic and functional diversity. The niche restriction was the main driving force of bacterial and fungal community assembly. Compared to no camping, camping increased the stability of bacterial networks but decreased the stability of fungal networks. Camping exerted a positive effect on the network by compressing the niche width and reduced the change in the network by reducing the niche overlap. Our results suggest that camping restructures the soil microbial composition, function, and network, and provides a novel insight into the effect of animal camping on soil microbial communities in grassland.}, }
@article {pmid36361939, year = {2022}, author = {Alves, R and Pazos-Gil, M and Medina-Carbonero, M and Sanz-Alcázar, A and Delaspre, F and Tamarit, J}, title = {Evolution of an Iron-Detoxifying Protein: Eukaryotic and Rickettsia Frataxins Contain a Conserved Site Which Is Not Present in Their Bacterial Homologues.}, journal = {International journal of molecular sciences}, volume = {23}, number = {21}, pages = {}, pmid = {36361939}, issn = {1422-0067}, mesh = {Humans ; Bacterial Proteins/chemistry/metabolism ; Escherichia coli/metabolism ; Escherichia coli Proteins/genetics ; Eukaryota/metabolism ; Friedreich Ataxia/genetics/metabolism ; Iron/metabolism ; *Iron-Binding Proteins/chemistry/metabolism ; *Neurodegenerative Diseases ; *Rickettsia/metabolism ; Tyrosine/metabolism ; Mitochondria/metabolism/microbiology ; }, abstract = {Friedreich's ataxia is a neurodegenerative disease caused by mutations in the frataxin gene. Frataxin homologues, including bacterial CyaY proteins, can be found in most species and play a fundamental role in mitochondrial iron homeostasis, either promoting iron assembly into metaloproteins or contributing to iron detoxification. While several lines of evidence suggest that eukaryotic frataxins are more effective than bacterial ones in iron detoxification, the residues involved in this gain of function are unknown. In this work, we analyze conservation of amino acid sequence and protein structure among frataxins and CyaY proteins to identify four highly conserved residue clusters and group them into potential functional clusters. Clusters 1, 2, and 4 are present in eukaryotic frataxins and bacterial CyaY proteins. Cluster 3, containing two serines, a tyrosine, and a glutamate, is only present in eukaryotic frataxins and on CyaY proteins from the Rickettsia genus. Residues from cluster 3 are blocking a small cavity of about 40 Å present in E. coli's CyaY. The function of this cluster is unknown, but we hypothesize that its tyrosine may contribute to prevent formation of reactive oxygen species during iron detoxification. This cluster provides an example of gain of function during evolution in a protein involved in iron homeostasis, as our results suggests that Cluster 3 was present in the endosymbiont ancestor of mitochondria and was conserved in eukaryotic frataxins.}, }
@article {pmid36360278, year = {2022}, author = {Montes-Rodríguez, IM and Cadilla, CL and López-Garriga, J and González-Méndez, R}, title = {Bioinformatic Characterization and Molecular Evolution of the Lucina pectinata Hemoglobins.}, journal = {Genes}, volume = {13}, number = {11}, pages = {}, pmid = {36360278}, issn = {2073-4425}, support = {U54 MD007600/MD/NIMHD NIH HHS/United States ; P20 GM103475/GM/NIGMS NIH HHS/United States ; R25 GM088023/GM/NIGMS NIH HHS/United States ; P41 RR006009/RR/NCRR NIH HHS/United States ; T36 GM008789/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Computational Biology ; Phylogeny ; Amino Acid Sequence ; Hemoglobins/genetics/metabolism ; *Bivalvia/genetics/metabolism ; Evolution, Molecular ; Sulfides ; Oxygen/metabolism ; }, abstract = {(1) Introduction: Lucina pectinata is a clam found in sulfide-rich mud environments that has three hemoglobins believed to be responsible for the transport of hydrogen sulfide (HbILp) and oxygen (HbIILp and HbIIILp) to chemoautotrophic endosymbionts. The physiological roles and evolution of these globins in sulfide-rich environments are not well understood. (2) Methods: We performed bioinformatic and phylogenetic analyses with 32 homologous mollusk globin sequences. Phylogenetics suggests a first gene duplication resulting in sulfide binding and oxygen binding genes. A more recent gene duplication gave rise to the two oxygen-binding hemoglobins. Multidimensional scaling analysis of the sequence space shows evolutionary drift of HbIILp and HbIIILp, while HbILp was closer to the Calyptogena hemoglobins. Further corroboration is seen by conservation in the coding region of hemoglobins from L. pectinata compared to those from Calyptogena. (3) Conclusions: Presence of glutamine in position E7 in organisms living in sulfide-rich environments can be considered an adaptation to prevent loss of protein function. In HbILp a substitution of phenylalanine in position B10 is accountable for its unique reactivity towards H2S. It appears that HbILp has been changing over time, apparently not subject to functional constraints of binding oxygen, and acquired a unique function for a specialized environment.}, }
@article {pmid36355038, year = {2022}, author = {Raval, PK and Garg, SG and Gould, SB}, title = {Endosymbiotic selective pressure at the origin of eukaryotic cell biology.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36355038}, issn = {2050-084X}, mesh = {*Eukaryotic Cells/physiology ; *Symbiosis/genetics ; Biological Evolution ; Eukaryota/genetics ; Archaea/genetics ; Cell Nucleus ; Meiosis ; Biology ; Phylogeny ; }, abstract = {The dichotomy that separates prokaryotic from eukaryotic cells runs deep. The transition from pro- to eukaryote evolution is poorly understood due to a lack of reliable intermediate forms and definitions regarding the nature of the first host that could no longer be considered a prokaryote, the first eukaryotic common ancestor, FECA. The last eukaryotic common ancestor, LECA, was a complex cell that united all traits characterising eukaryotic biology including a mitochondrion. The role of the endosymbiotic organelle in this radical transition towards complex life forms is, however, sometimes questioned. In particular the discovery of the asgard archaea has stimulated discussions regarding the pre-endosymbiotic complexity of FECA. Here we review differences and similarities among models that view eukaryotic traits as isolated coincidental events in asgard archaeal evolution or, on the contrary, as a result of and in response to endosymbiosis. Inspecting eukaryotic traits from the perspective of the endosymbiont uncovers that eukaryotic cell biology can be explained as having evolved as a solution to housing a semi-autonomous organelle and why the addition of another endosymbiont, the plastid, added no extra compartments. Mitochondria provided the selective pressures for the origin (and continued maintenance) of eukaryotic cell complexity. Moreover, they also provided the energetic benefit throughout eukaryogenesis for evolving thousands of gene families unique to eukaryotes. Hence, a synthesis of the current data lets us conclude that traits such as the Golgi apparatus, the nucleus, autophagosomes, and meiosis and sex evolved as a response to the selective pressures an endosymbiont imposes.}, }
@article {pmid36354861, year = {2022}, author = {Ali, S and Sajjad, A and Shakeel, Q and Farooqi, MA and Aqueel, MA and Tariq, K and Ullah, MI and Iqbal, A and Jamal, A and Saeed, MF and Manachini, B}, title = {Influence of Bacterial Secondary Symbionts in Sitobion avenae on Its Survival Fitness against Entomopathogenic Fungi, Beauveria bassiana and Metarhizium brunneum.}, journal = {Insects}, volume = {13}, number = {11}, pages = {}, pmid = {36354861}, issn = {2075-4450}, abstract = {The research was focused on the ability of wheat aphids Sitobion avenae, harboring bacterial secondary symbionts (BSS) Hamiltonella defensa or Regiella insecticola, to withstand exposure to fungal isolates of Beauveria bassiana and Metarhizium brunneum. In comparison to aphids lacking bacterial secondary symbionts, BSS considerably increased the lifespan of wheat aphids exposed to B. bassiana strains (Bb1022, EABb04/01-Tip) and M. brunneum strains (ART 2825 and BIPESCO 5) and also reduced the aphids' mortality. The wheat aphid clones lacking bacterial secondary symbionts were shown to be particularly vulnerable to M. brunneum strain BIPESCO 5. As opposed to wheat aphids carrying bacterial symbionts, fungal pathogens infected the wheat aphids lacking H. defensa and R. insecticola more quickly. When treated with fungal pathogens, bacterial endosymbionts had a favorable effect on the fecundity of their host aphids compared to the aphids lacking these symbionts, but there was no change in fungal sporulation on the deceased aphids. By defending their insect hosts against natural enemies, BSS increase the population of their host society and may have a significant impact on the development of their hosts.}, }
@article {pmid36352292, year = {2022}, author = {Xing, R and Zhang, HC and Gao, QB and Zhang, FQ and Chi, XF and Chen, SL}, title = {Bacterial communities associated with mushrooms in the Qinghai-Tibet Plateau are shaped by soil parameters.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36352292}, issn = {1618-1905}, abstract = {Fungi capable of producing fruit bodies are essential food and medicine resources. Despite recent advances in the study of microbial communities in mycorrhizospheres, little is known about the bacterial communities contained in fruit bodies. Using high-throughput sequencing, we investigated the bacterial communities in four species of mushrooms located on the alpine meadow and saline-alkali soil of the Qinghai-Tibet Plateau (QTP). Proteobacteria (51.7% on average) and Actinobacteria (28.2% on average) were the dominant phyla in all of the sampled fairy ring fruit bodies, and Acidobacteria (27.5% on average) and Proteobacteria (25.7% on average) dominated their adjacent soils. For the Agria. Bitorquis, Actinobacteria was the dominant phylum in its fruit body (67.5% on average) and adjacent soils (65.9% on average). The alpha diversity (i.e., Chao1, Shannon, Richness, and Simpson indexes) of the bacterial communities in the fruit bodies were significantly lower than those in the soil samples. All of the fungi shared more than half of their bacterial phyla and 16.2% of their total operational taxonomic units (OTUs) with their adjacent soil. Moreover, NH4[+] and pH were the key factors associated with bacterial communities in the fruit bodies and soils, respectively. These results indicate that the fungi tend to create a unique niche that selects for specific members of the bacterial community. Using culture-dependent methods, we also isolated 27 bacterial species belonging to three phyla and five classes from fruit bodies and soils. The strains isolated will be useful for future research on interactions between mushroom-forming fungi and their bacterial endosymbionts.}, }
@article {pmid36339946, year = {2022}, author = {Compton, A and Tu, Z}, title = {Natural and Engineered Sex Ratio Distortion in Insects.}, journal = {Frontiers in ecology and evolution}, volume = {10}, number = {}, pages = {}, pmid = {36339946}, issn = {2296-701X}, support = {R01 AI121284/AI/NIAID NIH HHS/United States ; R01 AI123338/AI/NIAID NIH HHS/United States ; R01 AI157491/AI/NIAID NIH HHS/United States ; R21 AI154871/AI/NIAID NIH HHS/United States ; }, abstract = {Insects have evolved highly diverse genetic sex-determination mechanisms and a relatively balanced male to female sex ratio is generally expected. However, selection may shift the optimal sex ratio while meiotic drive and endosymbiont manipulation can result in sex ratio distortion (SRD). Recent advances in sex chromosome genomics and CRISPR/Cas9-mediated genome editing brought significant insights into the molecular regulators of sex determination in an increasing number of insects and provided new ways to engineer SRD. We review these advances and discuss both naturally occurring and engineered SRD in the context of the Anthropocene. We emphasize SRD-mediated biological control of insects to help improve One Health, sustain agriculture, and conserve endangered species.}, }
@article {pmid36336686, year = {2022}, author = {McIlroy, SE and terHorst, CP and Teece, M and Coffroth, MA}, title = {Nutrient dynamics in coral symbiosis depend on both the relative and absolute abundance of Symbiodiniaceae species.}, journal = {Microbiome}, volume = {10}, number = {1}, pages = {192}, pmid = {36336686}, issn = {2049-2618}, mesh = {Animals ; *Anthozoa/physiology ; Symbiosis/physiology ; *Dinoflagellida/physiology ; Nitrogen ; Carbon ; Nutrients ; Coral Reefs ; }, abstract = {BACKGROUND: Symbionts provide a variety of reproductive, nutritional, and defensive resources to their hosts, but those resources can vary depending on symbiont community composition. As genetic techniques open our eyes to the breadth of symbiont diversity within myriad microbiomes, symbiosis research has begun to consider what ecological mechanisms affect the identity and relative abundance of symbiont species and how this community structure impacts resource exchange among partners. Here, we manipulated the in hospite density and relative ratio of two species of coral endosymbionts (Symbiodinium microadriaticum and Breviolum minutum) and used stable isotope enrichment to trace nutrient exchange with the host, Briareum asbestinum.<br><br>RESULTS: The patterns of uptake and translocation of carbon and nitrogen varied with both density and ratio of symbionts. Once a density threshold was reached, carbon acquisition decreased with increasing proportions of S. microadriaticum. In hosts dominated by B. minutum, nitrogen uptake was density independent and intermediate. Conversely, for those corals dominated by S. microadriaticum, nitrogen uptake decreased as densities increased, and as a result, these hosts had the overall highest (at low density) and lowest (at high density) nitrogen enrichment.<br><br>CONCLUSIONS: Our findings show that the uptake and sharing of nutrients was strongly dependent on both the density of symbionts within the host, as well as which symbiont species was dominant. Together, these complex interactive effects suggest that host regulation and the repression of in hospite symbiont competition can ultimately lead to a more productive mutualism. Video Abstract.}, }
@article {pmid36330308, year = {2022}, author = {Beekman, MM and Donner, SH and Litjens, JJH and Dicke, M and Zwaan, BJ and Verhulst, EC and Pannebakker, BA}, title = {Do aphids in Dutch sweet pepper greenhouses carry heritable elements that protect them against biocontrol parasitoids?.}, journal = {Evolutionary applications}, volume = {15}, number = {10}, pages = {1580-1593}, pmid = {36330308}, issn = {1752-4571}, abstract = {Biological control (biocontrol) of crop pests is a sustainable alternative to the use of biodiversity and organismal health-harming chemical pesticides. Aphids can be biologically controlled with parasitoid wasps; however, variable results of parasitoid-based aphid biocontrol in greenhouses are reported. Aphids may display genetically encoded (endogenous) defences that increase aphid resistance against parasitoids as under high parasitoid pressure there will be selection for parasitoid-resistant aphids, potentially affecting the success of parasitoid-based aphid biocontrol in greenhouses. Additionally, aphids may carry secondary bacterial endosymbionts that protect them against parasitoids. We studied whether there is variation in either of these heritable elements in aphids in greenhouses of sweet pepper, an agro-economically important crop in the Netherlands that is prone to aphid pests and where pest management heavily relies on biocontrol. We sampled aphid populations in organic (biocontrol only) and conventional (biocontrol and pesticides) sweet pepper greenhouses in the Netherlands during the 2019 crop growth season. We assessed the aphid microbiome through both diagnostic PCR and 16S rRNA sequencing and did not detect any secondary endosymbionts in the two most encountered aphid species, Myzus persicae and Aulacorthum solani. We also compared multiple aphid lines collected from different greenhouses for variation in levels of endogenous-based resistance against the parasitoids commonly used as biocontrol agents. We found no differences in the levels of endogenous-based resistance between different aphid lines. This study does not support the hypothesis that protective endosymbionts or the presence of endogenous resistant aphid lines affects the success of parasitoid-based biocontrol of aphids in Dutch greenhouses. Future investigations will need to address what is causing the variable successes of aphid biocontrol and what (biological and management-related) lessons can be learned for aphid control in other crops, and biocontrol in general.}, }
@article {pmid36321837, year = {2022}, author = {McGlynn, SE and Perkins, G and Sim, MS and Mackey, M and Deerinck, TJ and Thor, A and Phan, S and Ballard, D and Ellisman, MH and Orphan, VJ}, title = {A Cristae-Like Microcompartment in Desulfobacterota.}, journal = {mBio}, volume = {}, number = {}, pages = {e0161322}, doi = {10.1128/mbio.01613-22}, pmid = {36321837}, issn = {2150-7511}, abstract = {Some Alphaproteobacteria contain intracytoplasmic membranes (ICMs) and proteins homologous to those responsible for the mitochondrial cristae, an observation which has given rise to the hypothesis that the Alphaproteobacteria endosymbiont had already evolved cristae-like structures and functions. However, our knowledge of microbial fine structure is still limited, leaving open the possibility of structurally homologous ICMs outside the Alphaproteobacteria. Here, we report on the detailed characterization of lamellar cristae-like ICMs in environmental sulfate-reducing Desulfobacterota that form syntrophic partnerships with anaerobic methane-oxidizing (ANME) archaea. These structures are junction-bound to the cytoplasmic membrane and resemble the form seen in the lamellar cristae of opisthokont mitochondria. Extending these observations, we also characterized similar structures in Desulfovibrio carbinolicus, a close relative of the magnetotactic D. magneticus, which does not contain magnetosomes. Despite a remarkable structural similarity, the key proteins involved in cristae formation have not yet been identified in Desulfobacterota, suggesting that an analogous, but not a homologous, protein organization system developed during the evolution of some members of Desulfobacterota. IMPORTANCE Working with anaerobic consortia of methane oxidizing ANME archaea and their sulfate-reducing bacterial partners recovered from deep sea sediments and with the related sulfate-reducing bacterial isolate D. carbinolicus, we discovered that their intracytoplasmic membranes (ICMs) appear remarkably similar to lamellar cristae. Three-dimensional electron microscopy allowed for the novel analysis of the nanoscale attachment of ICMs to the cytoplasmic membrane, and these ICMs are structurally nearly identical to the crista junction architecture seen in metazoan mitochondria. However, the core junction-forming proteins must be different. The outer membrane vesicles were observed to bud from syntrophic Desulfobacterota, and darkly stained granules were prominent in both Desulfobacterota and D. carbinolicus. These findings expand the taxonomic breadth of ICM-producing microorganisms and add to our understanding of three-dimensional microbial fine structure in environmental microorganisms.}, }
@article {pmid36319835, year = {2022}, author = {Moffat, JJ and Coffroth, MA and Wallingford, PD and terHorst, CP}, title = {Symbiont genotype influences holobiont response to increased temperature.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {18394}, pmid = {36319835}, issn = {2045-2322}, mesh = {Animals ; Temperature ; Coral Reefs ; *Anthozoa/physiology ; *Dinoflagellida/physiology ; Symbiosis ; Genotype ; }, abstract = {As coral reefs face warming oceans and increased coral bleaching, a whitening of the coral due to loss of microalgal endosymbionts, the possibility of evolutionary rescue offers some hope for reef persistence. In tightly linked mutualisms, evolutionary rescue may occur through evolution of the host and/or endosymbionts. Many obligate mutualisms are composed of relatively small, fast-growing symbionts with greater potential to evolve on ecologically relevant time scales than their relatively large, slower growing hosts. Numerous jellyfish species harbor closely related endosymbiont taxa to other cnidarian species such as coral, and are commonly used as a model system for investigating cnidarian mutualisms. We examined the potential for adaptation of the upside-down jellyfish Cassiopea xamachana to increased temperature via evolution of its microalgal endosymbiont, Symbiodinium microadriaticum. We quantified trait variation among five algal genotypes in response to three temperatures (26 °C, 30 °C, and 32 °C) and fitness of hosts infected with each genotype. All genotypes showed positive growth rates at each temperature, but rates of respiration and photosynthesis decreased with increased temperature. Responses varied among genotypes but were unrelated to genetic similarity. The effect of temperature on asexual reproduction and the timing of development in the host also depended on the genotype of the symbiont. Natural selection could favor different algal genotypes at different temperatures, affecting host fitness. This eco-evolutionary interaction may be a critical component of understanding species resilience in increasingly stressful environments.}, }
@article {pmid36315059, year = {2022}, author = {Shantz, AA and Ladd, MC and Ezzat, L and Schmitt, RJ and Holbrook, SJ and Schmeltzer, E and Vega Thurber, R and Burkepile, DE}, title = {Positive interactions between corals and damselfish increase coral resistance to temperature stress.}, journal = {Global change biology}, volume = {}, number = {}, pages = {}, doi = {10.1111/gcb.16480}, pmid = {36315059}, issn = {1365-2486}, abstract = {By the century's end, many tropical seas will reach temperatures exceeding most coral species' thermal tolerance on an annual basis. The persistence of corals in these regions will, therefore, depend on their abilities to tolerate recurrent thermal stress. Although ecologists have long recognized that positive interspecific interactions can ameliorate environmental stress to expand the realized niche of plants and animals, coral bleaching studies have largely overlooked how interactions with community members outside of the coral holobiont shape the bleaching response. Here, we subjected a common coral, Pocillopora grandis, to 10 days of thermal stress in aquaria with and without the damselfish Dascyllus flavicaudus (yellowtail dascyllus), which commonly shelter within these corals, to examine how interactions with damselfish impacted coral thermal tolerance. Corals often benefit from nutrients excreted by animals they interact with and prior to thermal stress, corals grown with damselfish showed improved photophysiology (Fv /Fm) and developed larger endosymbiont populations. When exposed to thermal stress, corals with fish performed as well as control corals maintained at ambient temperatures without fish. In contrast, corals exposed to thermal stress without fish experienced photophysiological impairment, a more than 50% decline in endosymbiont density, and a 36% decrease in tissue protein content. At the end of the experiment, thermal stress caused average calcification rates to decrease by over 80% when damselfish were absent but increase nearly 25% when damselfish were present. Our study indicates that damselfish-derived nutrients can increase coral thermal tolerance and are consistent with the Stress Gradient Hypothesis, which predicts that positive interactions become increasingly important for structuring communities as environmental stress increases. Because warming of just a few degrees can exceed corals' temperature tolerance to trigger bleaching and mortality, positive interactions could play a critical role in maintaining some coral species in warming regions until climate change is aggressively addressed.}, }
@article {pmid36314939, year = {2022}, author = {Palmieri, L and Pavarini, R and Sharma, PP}, title = {Draft Genome Sequence of "Candidatus Nardonella dryophthoridicola" Strain NARMHE1, Endosymbiont of Metamasius hemipterus (Coleoptera, Curculionidae, Dryophthorinae).}, journal = {Microbiology resource announcements}, volume = {11}, number = {11}, pages = {e0073822}, pmid = {36314939}, issn = {2576-098X}, abstract = {Here, we report the draft genome and annotation of "Candidatus Nardonella dryophthoridicola" strain NARMHE1, obtained via Oxford Nanopore sequencing of the ovaries of its host, the weevil Metamasius hemipterus, from a population from southeast Brazil.}, }
@article {pmid36311398, year = {2022}, author = {Park, E and Poulin, R}, title = {Extremely divergent COI sequences within an amphipod species complex: A possible role for endosymbionts?.}, journal = {Ecology and evolution}, volume = {12}, number = {10}, pages = {e9448}, pmid = {36311398}, issn = {2045-7758}, abstract = {Some heritable endosymbionts can affect host mtDNA evolution in various ways. Amphipods host diverse endosymbionts, but whether their mtDNA has been influenced by these endosymbionts has yet to be considered. Here, we investigated the role of endosymbionts (microsporidians and Rickettsia) in explaining highly divergent COI sequences in Paracalliope fluviatilis species complex, the most common freshwater amphipods in New Zealand. We first contrasted phylogeographic patterns using COI, ITS, and 28S sequences. While molecular species delimitation methods based on 28S sequences supported 3-4 potential species (N, C, SA, and SB) among freshwater lineages, COI sequences supported 17-27 putative species reflecting high inter-population divergence. The deep divergence between NC and S lineages (~20%; 28S) and the substitution saturation on the 3rd codon position of COI detected even within one lineage (SA) indicate a very high level of morphological stasis. Interestingly, individuals infected and uninfected by Rickettsia comprised divergent COI lineages in one of four populations tested, suggesting a potential influence of endosymbionts in mtDNA patterns. We propose several plausible explanations for divergent COI lineages, although they would need further testing with multiple lines of evidence. Lastly, due to common morphological stasis and the presence of endosymbionts, phylogeographic patterns of amphipods based on mtDNA should be interpreted with caution.}, }
@article {pmid36302793, year = {2022}, author = {Spanner, C and Darienko, T and Filker, S and Sonntag, B and Pröschold, T}, title = {Morphological diversity and molecular phylogeny of five Paramecium bursaria (Alveolata, Ciliophora, Oligohymenophorea) syngens and the identification of their green algal endosymbionts.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {18089}, pmid = {36302793}, issn = {2045-2322}, mesh = {*Paramecium/genetics ; Phylogeny ; *Oligohymenophorea ; *Alveolata ; *Chlorella vulgaris ; *Ciliophora ; *Chlorophyta/genetics ; Symbiosis/genetics ; }, abstract = {Paramecium bursaria is a mixotrophic ciliate species, which is common in stagnant and slow-flowing, nutrient-rich waters. It is usually found living in symbiosis with zoochlorellae (green algae) of the genera Chlorella or Micractinium. We investigated P. bursaria isolates from around the world, some of which have already been extensively studied in various laboratories, but whose morphological and genetic identity has not yet been completely clarified. Phylogenetic analyses of the SSU and ITS rDNA sequences revealed five highly supported lineages, which corresponded to the syngen and most likely to the biological species assignment. These syngens R1-R5 could also be distinguished by unique synapomorphies in the secondary structures of the SSU and the ITS. Considering these synapomorphies, we could clearly assign the existing GenBank entries of P. bursaria to specific syngens. In addition, we discovered synapomorphies at amino acids of the COI gene for the identification of the syngens. Using the metadata of these entries, most syngens showed a worldwide distribution, however, the syngens R1 and R5 were only found in Europe. From morphology, the syngens did not show any significant deviations. The investigated strains had either Chlorella variabilis, Chlorella vulgaris or Micractinium conductrix as endosymbionts.}, }
@article {pmid36301108, year = {2022}, author = {Halter, T and Hendrickx, F and Horn, M and Manzano-Marín, A}, title = {A Novel Widespread MITE Element in the Repeat-Rich Genome of the Cardinium Endosymbiont of the Spider Oedothorax gibbosus.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0262722}, doi = {10.1128/spectrum.02627-22}, pmid = {36301108}, issn = {2165-0497}, abstract = {Free-living bacteria have evolved multiple times to become host-restricted endosymbionts. The transition from a free-living to a host-restricted lifestyle comes with a number of different genomic changes, including a massive loss of genes. In host-restricted endosymbionts, gene inactivation and genome reduction are facilitated by mobile genetic elements, mainly insertion sequences (ISs). ISs are small autonomous mobile elements, and one of, if not the most, abundant transposable elements in bacteria. Proliferation of ISs is common in some facultative endosymbionts, and is likely driven by the transmission bottlenecks, which increase the level of genetic drift. In this study, we present a manually curated genome annotation for a Cardinium endosymbiont of the dwarf spider Oedothorax gibbosus. Cardinium species are host-restricted endosymbionts that, similarly to ColbachiaWolbachia spp., include strains capable of manipulating host reproduction. Through the focus on mobile elements, the annotation revealed a rampant spread of ISs, extending earlier observations in other Cardinium genomes. We found that a large proportion of IS elements are pseudogenized, with many displaying evidence of recent inactivation. Most notably, we describe the lineage-specific emergence and spread of a novel IS-derived Miniature Inverted repeat Transposable Element (MITE), likely being actively maintained by intact copies of its parental IS982-family element. This study highlights the relevance of manual curation of these repeat-rich endosymbiont genomes for the discovery of novel MITEs, as well as the possible role these understudied elements might play in genome streamlining. IMPORTANCE Cardinium bacteria, a widespread symbiont lineage found across insects and nematodes, have been linked to reproductive manipulation of their hosts. However, the study of Cardinium has been hampered by the lack of comprehensive genomic resources. The high content of mobile genetic elements, namely, insertion sequences (ISs), has long complicated the analyses and proper annotations of these genomes. In this study, we present a manually curated annotation of the Cardinium symbiont of the spider Oedothorax gibbosus. Most notably, we describe a novel IS-like element found exclusively in this strain. We show that this mobile element likely evolved from a defective copy of its parental IS and then spread throughout the genome, contributing to the pseudogenization of several other mobile elements. We propose this element is likely being maintained by the intact copies of its parental IS element and that other similar elements in the genome could potentially follow this route.}, }
@article {pmid36299729, year = {2022}, author = {Lima, MS and Hamerski, L and Silva, TA and da Cruz, MLR and Varasteh, T and Tschoeke, DA and Atella, GC and de Souza, W and Thompson, FL and Thompson, CC}, title = {Insights on the biochemical and cellular changes induced by heat stress in the Cladocopium isolated from coral Mussismilia braziliensis.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {973980}, pmid = {36299729}, issn = {1664-302X}, abstract = {Corals are treatened by global warming. Bleaching is one immediate effect of global warming, resulting from the loss of photosynthetic endosymbiont dinoflagellates. Understanding host-symbiont associations are critical for assessing coral's habitat requirements and its response to environmental changes. Cladocopium (formerly family Symbiodiniaceae clade C) are dominant endosymbionts in the reef-building coral, Mussismilia braziliensis. This study aimed to investigate the effect of temperature on the biochemical and cellular features of Cladocopium. Heat stress increased oxygen (O2) and decreased proteins, pigments (Chla + Chlc2), hexadecanoic acid- methyl ester, methyl stearate, and octadecenoic acid (Z)- methyl ester molecules. In addition, there was an increase in neutral lipids such as esterified cholesterol and a decrease in free fatty acids that may have been incorporated for the production of lipid droplets. Transmission electron microscopy (TEM) demonstrated that Cladocopium cells subjected to heat stress had thinner cell walls, deformation of chloroplasts, and increased lipid droplets after 3 days at 28°C. These findings indicate that thermal stress negatively affects isolated Cladocopium spp. from Mussismilia host coral.}, }
@article {pmid36299486, year = {2022}, author = {Hargitai, D and Kenéz, L and Al-Lami, M and Szenczi, G and Lőrincz, P and Juhász, G}, title = {Autophagy controls Wolbachia infection upon bacterial damage and in aging Drosophila.}, journal = {Frontiers in cell and developmental biology}, volume = {10}, number = {}, pages = {976882}, pmid = {36299486}, issn = {2296-634X}, abstract = {Autophagy is a conserved catabolic process in eukaryotic cells that degrades intracellular components in lysosomes, often in an organelle-specific selective manner (mitophagy, ERphagy, etc). Cells also use autophagy as a defense mechanism, eliminating intracellular pathogens via selective degradation known as xenophagy. Wolbachia pipientis is a Gram-negative intracellular bacterium, which is one of the most common parasites on Earth affecting approximately half of terrestrial arthropods. Interestingly, infection grants the host resistance against other pathogens and modulates lifespan, so this bacterium resembles an endosymbiont. Here we demonstrate that Drosophila somatic cells normally degrade a subset of these bacterial cells, and autophagy is required for selective elimination of Wolbachia upon antibiotic damage. In line with these, Wolbachia overpopulates in autophagy-compromised animals during aging while its presence fails to affect host lifespan unlike in case of control flies. The autophagic degradation of Wolbachia thus represents a novel antibacterial mechanism that controls the propagation of this unique bacterium, behaving both as parasite and endosymbiont at the same time.}, }
@article {pmid36296266, year = {2022}, author = {Díaz-Abad, L and Bacco-Mannina, N and Miguel Madeira, F and Serrao, EA and Regalla, A and Patrício, AR and Frade, PR}, title = {Red, Gold and Green: Microbial Contribution of Rhodophyta and Other Algae to Green Turtle (Chelonia mydas) Gut Microbiome.}, journal = {Microorganisms}, volume = {10}, number = {10}, pages = {}, pmid = {36296266}, issn = {2076-2607}, abstract = {The fitness of the endangered green sea turtle (Chelonia mydas) may be strongly affected by its gut microbiome, as microbes play important roles in host nutrition and health. This study aimed at establishing environmental microbial baselines that can be used to assess turtle health under altered future conditions. We characterized the microbiome associated with the gastrointestinal tract of green turtles from Guinea Bissau in different life stages and associated with their food items, using 16S rRNA metabarcoding. We found that the most abundant (% relative abundance) bacterial phyla across the gastrointestinal sections were Proteobacteria (68.1 ± 13.9% "amplicon sequence variants", ASVs), Bacteroidetes (15.1 ± 10.1%) and Firmicutes (14.7 ± 21.7%). Additionally, we found the presence of two red algae bacterial indicator ASVs (the Alphaproteobacteria Brucella pinnipedialis with 75 ± 0% and a Gammaproteobacteria identified as methanotrophic endosymbiont of Bathymodiolus, with <1%) in cloacal compartments, along with six bacterial ASVs shared only between cloacal and local environmental red algae samples. We corroborate previous results demonstrating that green turtles fed on red algae (but, to a lower extent, also seagrass and brown algae), thus, acquiring microbial components that potentially aid them digest these food items. This study is a foundation for better understanding the microbial composition of sea turtle digestive tracts.}, }
@article {pmid36296199, year = {2022}, author = {Mofokeng, LS and Smit, NJ and Cook, CA}, title = {Molecular Detection of Tick-Borne Bacteria from Amblyomma (Acari: Ixodidae) Ticks Collected from Reptiles in South Africa.}, journal = {Microorganisms}, volume = {10}, number = {10}, pages = {}, pmid = {36296199}, issn = {2076-2607}, abstract = {Reptiles are hosts for various tick species and tick-associated organisms, many of which are zoonotic. However, little is known about the presence and diversity of tick-borne bacteria infecting reptiles and their ticks in South Africa. Amblyomma ticks (n = 253) collected from reptiles were screened for the presence of Coxiella, Anaplasma, Rickettsia, and Borrelia species by amplification, sequencing and phylogenetic analysis of the 16S rRNA, 23S rRNA, gltA, OmpA, and Flagellin genes, respectively. This study recorded the presence of reptile associated Borrelia species and Coxiella-like endosymbiont in South Africa for the first time. Furthermore, a spotted fever group Rickettsia species was observed in 7 Amblyomma marmoreum and 14 Amblyomma sylvaticum from tortoises of genera Kinixys and Chersina. Francisella-like endosymbiont was observed from 2 Amblyomma latum collected from the Mozambique spitting cobra, Naja mossambica. Coxiella burnetii and Anaplasma spp., were not detected from the current samples. Although the direct evidence that reptiles can act as reservoir hosts remains to be determined, observations from this study provide indications that reptilian ticks may play a role in the transmission of pathogenic bacteria to homothermic animals. Furthermore, the absence of Anaplasma spp., and C. burnetii does not mean that these pathogens should be completely neglected.}, }
@article {pmid36293276, year = {2022}, author = {Lesiak-Markowicz, I and Walochnik, J and Stary, A and Fürnkranz, U}, title = {Characterisation of Trichomonas vaginalis Isolates Collected from Patients in Vienna between 2019 and 2021.}, journal = {International journal of molecular sciences}, volume = {23}, number = {20}, pages = {}, pmid = {36293276}, issn = {1422-0067}, mesh = {Female ; Humans ; *Trichomonas vaginalis/genetics ; Metronidazole/pharmacology ; HeLa Cells ; *Trichomonas Infections ; Mycoplasma hominis/genetics ; *Totiviridae ; }, abstract = {Trichomonas vaginalis (TV) is the causative agent of trichomoniasis, the most common nonviral sexually transmitted disease. TV can carry symbionts such as Trichomonas vaginalis virus (TVV) or Mycoplasma hominis. Four distinct strains of TV are known: TVV1, TVV2, TVV3, and TVV4. The aim of the current study was to characterise TV isolates from Austrian patients for the presence of symbionts, and to determine their effect on metronidazole susceptibility and cytotoxicity against HeLa cells. We collected 82 TV isolates and detected presence of TVV (TVV1, TVV2, or TVV3) in 29 of them (35%); no TVV4 was detected. M. hominis was detected in vaginal/urethral swabs by culture in 37% of the TV-positive patients; M. hominis DNA was found in 28% of the TV isolates by PCR. In 15% of the patients, M. hominis was detected in the clinical samples as well as within the respective TV isolates. In 22% of the patients, M. hominis was detected by culture only. In 11 patients, M. hominis was detected only within the respective cultured TV isolates (13%), while the swab samples were negative for M. hominis. Our results provide a first insight into the distribution of symbionts in TV isolates from Austrian patients. We did not observe significant effects of the symbionts on metronidazole susceptibility, cytotoxicity, or severity of symptoms.}, }
@article {pmid36282692, year = {2022}, author = {Haziqah-Rashid, A and Stobierska, K and Glenn, L and Metelmann, S and Sherlock, K and Chrostek, E and C Blagrove, MS}, title = {Determining Temperature Preference of Mosquitoes and Other Ectotherms.}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {187}, pages = {}, doi = {10.3791/64356}, pmid = {36282692}, issn = {1940-087X}, mesh = {Animals ; Temperature ; *Culicidae ; Aluminum ; Incubators ; Insecta ; }, abstract = {Most insects and other ectotherms have a relatively narrow optimal temperature window, and deviation from their optima can have significant effects on their fitness, as well as other characteristics. Consequently, many such ectotherms seek out their optimal temperature range. Although temperature preferences of mosquitoes and other insects have been well studied, the traditional experimental setup is performed using a temperature gradient on an aluminum surface in a highly enclosed space. In some cases, this equipment restricts many natural behaviors, such as flying, which may be important in preference selection. The objective of this study is to observe insect preference for air temperature by using a two-chamber apparatus with sufficient room for flight. The two chambers consist of independent temperature-controlled incubators, each with a large aperture. The incubators are connected by these apertures using a short acrylic bridge. Inside the incubators are two netted cages, linked via the apertures and bridge, allowing the insects to freely fly between the different conditions. The acrylic bridge also acts as a temperature gradient between the two incubators. Due to the spacious area in the cage and easy construction, this method can be used to study any small ectotherm and/or any manipulation which may alter temperature preference including sensory organ manipulation, diet, gut flora, and endosymbiont presence at biosafety levels 1 or 2 (BSL 1 or 2). Additionally, the apparatus can be used for the study of pathogen infection using further containment (e.g., inside of a biosafety cabinet) at BSL 3.}, }
@article {pmid36270115, year = {2022}, author = {Araújo, IM and Cordeiro, MD and Soares, RFP and Guterres, A and Sanavria, A and Baêta, BA and da Fonseca, AH}, title = {Survey of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {6}, pages = {102037}, doi = {10.1016/j.ttbdis.2022.102037}, pmid = {36270115}, issn = {1877-9603}, abstract = {This study evaluates the presence of bacterial and protozoan agents in ticks and fleas found on wild animals in the state of Rio de Janeiro, Brazil. These ectoparasites were collected on mammal species Hydrochoerus hydrochaeris, Tapirus terrestris, Dicotyles tajacu, Didelphis aurita, Cuniculus paca, Cerdocyon thous, and Coendou prehensilis, and on the terrestrial bird Dromaius novaehollandiae. Ticks and fleas were identified morphologically using specific taxonomic keys. A total of 396 ticks and 54 fleas were tested via polymerase chain reaction (PCR) for the presence of Rickettsia spp., Borrelia spp., microorganisms of the order Piroplasmida and Anaplasmataceae family. This total is distributed among nine tick species of the genus Amblyomma and one flea species. Rickettsia bellii was detected in Amblyomma dubitatum and Amblyomma pacae; Rickettsia sp. strain AL was found in Amblyomma longirostre; Rickettsia parkeri strain Atlantic rainforest was found in Amblyomma ovale; and "Candidatus Rickettsia senegalensis" and Rickettsia felis were detected in Ctenocephalides felis felis. Wolbachia sp. was detected in C. f. felis, and Borrelia sp. was detected in Amblyomma calcaratum (here named Borrelia sp. strain Acalc110). All tested samples were negative for Ehrlichia spp. and microorganisms of the Piroplasmida order. This study detected a new bacterial strain, Borrelia sp. strain Acalc 110 (which is genetically close to B. miyamotoi and B. venezuelensis) and the Rickettsia sp. strain 19P, which is 100% similar to "Ca. R. senegalensis", a bacterium recently discovered and now being reported for the first time in Brazil.}, }
@article {pmid36261834, year = {2022}, author = {Numan, M and Islam, N and Adnan, M and Zaman Safi, S and Chitimia-Dobler, L and Labruna, MB and Ali, A}, title = {First genetic report of Ixodes kashmiricus and associated Rickettsia sp.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {378}, pmid = {36261834}, issn = {1756-3305}, mesh = {Humans ; Male ; Female ; Animals ; Sheep/genetics ; *Ixodes/microbiology ; Phylogeny ; *Rickettsia/genetics ; *Ixodidae/microbiology ; Goats ; DNA, Ribosomal ; }, abstract = {BACKGROUND: Hard ticks (Ixodidae) are hematophagous ectoparasites that transmit various pathogens to a variety of hosts including humans. Transhumant herds have been involved in the spread of ticks and associated Rickettsia spp., and studies on this neglected topic have been unexplored in many regions including Pakistan. This study aimed to investigate ticks infesting transhumant herds of sheep (Ovis aries) and goats (Capra hircus) in district Shangla, Khyber Pakhtunkhwa, Pakistan.<br><br>METHODS: Of the 144 examined animals, 112 hosts (68 sheep and 44 goats) of transhumant herds were infested by 419 ticks of different life stages including nymphs (105; 25%), males (58; 14%) and females (256; 61%). For molecular analyses, DNA was extracted from 64 collected ticks and subjected to PCR for the amplification of tick 16S rDNA and ITS2 partial sequences and for the amplification of rickettsial gltA and ompA gene sequences.<br><br>RESULTS: All tick specimens were identified as Ixodes kashmiricus based on morphological features. The obtained 16S rDNA and ITS2 sequences showed 95.7% and 95.3% identity, respectively, with Ixodes kazakstani reported from Kyrgyzstan. In the phylogenetic tree, the sequences clustered with members of the Ixodes ricinus species complex, including I. kazakstani and Ixodes apronophorus. Additionally, rickettsial gltA and ompA partial sequences were 99.7% identical to Rickettsia sp. endosymbiont of Ixodes spp. from Panama and Costa Rica and 99.2% with Rickettsia endosymbiont from the USA. Phylogenetically, the rickettsial gltA and ompA partial sequences from I. kashmiricus clustered with various haplotypes of Rickettsia endosymbiont, which were sister cladded to Rickettsia monacensis.<br><br>CONCLUSIONS: This is the first genetic report of I. kashmiricus and associated Rickettsia sp. Large-scale tick surveillance studies across the country are needed to investigate Ixodes ticks and associated pathogens.}, }
@article {pmid36250862, year = {2022}, author = {Huggins, LG and Colella, V and Atapattu, U and Koehler, AV and Traub, RJ}, title = {Nanopore Sequencing Using the Full-Length 16S rRNA Gene for Detection of Blood-Borne Bacteria in Dogs Reveals a Novel Species of Hemotropic Mycoplasma.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0308822}, doi = {10.1128/spectrum.03088-22}, pmid = {36250862}, issn = {2165-0497}, abstract = {Dogs across the globe are afflicted by diverse blood- and vector-borne bacteria (VBB), many of which cause severe disease and can be fatal. Diagnosis of VBB infections can be challenging due to the low concentration of bacteria in the blood, the frequent occurrence of coinfections, and the wide range of known, emerging, and potentially novel VBB species encounterable. Therefore, there is a need for diagnostics that address these challenges by being both sensitive and capable of detecting all VBB simultaneously. We detail the first employment of a nanopore-based sequencing methodology conducted on the Oxford Nanopore Technologies (ONT) MinION device to accurately elucidate the "hemobacteriome" from canine blood through sequencing of the full-length 16S rRNA gene. We detected a diverse range of important canine VBB, including Ehrlichia canis, Anaplasma platys, Mycoplasma haemocanis, Bartonella clarridgeiae, "Candidatus Mycoplasma haematoparvum", a novel species of hemotropic mycoplasma, and Wolbachia endosymbionts of filarial worms, indicative of filariasis. Our nanopore-based protocol was equivalent in sensitivity to both quantitative PCR (qPCR) and Illumina sequencing when benchmarked against these methods, achieving high agreement as defined by the kappa statistics (k > 0.81) for three key VBB. Utilizing the ability of the ONT' MinION device to sequence long read lengths provides an excellent alternative diagnostic method by which the hemobacteriome can be accurately characterized to the species level in a way previously unachievable using short reads. We envision our method to be translatable to multiple contexts, such as the detection of VBB in other vertebrate hosts, including humans, while the small size of the MinION device is highly amenable to field use. IMPORTANCE Blood- and vector-borne bacteria (VBB) can cause severe pathology and even be lethal for dogs in many regions across the globe. Accurate characterization of all the bacterial pathogens infecting a canine host is critical, as coinfections are common and emerging and novel pathogens that may go undetected by traditional diagnostics frequently arise. Deep sequencing using devices from Oxford Nanopore Technologies (ONT) provides a solution, as the long read lengths achievable provide species-level taxonomic identification of pathogens that previous short-read technologies could not accomplish. We developed a protocol using ONT' MinION sequencer to accurately detect and classify a wide spectrum of VBB from canine blood at a sensitivity comparable to that of regularly used diagnostics, such as qPCR. This protocol demonstrates great potential for use in biosurveillance and biosecurity operations for the detection of VBB in a range of vertebrate hosts, while the MinION sequencer's portability allows this method to be used easily in the field.}, }
@article {pmid36246278, year = {2022}, author = {Li, Z and Czajkowski, R}, title = {Editorial: Insights in microbial symbioses: 2021.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1022893}, doi = {10.3389/fmicb.2022.1022893}, pmid = {36246278}, issn = {1664-302X}, }
@article {pmid36246272, year = {2022}, author = {Bensig, EO and Valadez-Cano, C and Kuang, Z and Freire, IR and Reyes-Prieto, A and MacLellan, SR}, title = {The two-component regulatory system CenK-CenR regulates expression of a previously uncharacterized protein required for salinity and oxidative stress tolerance in Sinorhizobium meliloti.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1020932}, pmid = {36246272}, issn = {1664-302X}, abstract = {Genes of unknown function constitute a considerable fraction of most bacterial genomes. In a Tn5-based search for stress response genes in the nitrogen-fixing facultative endosymbiont Sinorhizobium (Ensifer) meliloti, we identified a previously uncharacterized gene required for growth on solid media with increased NaCl concentrations. The encoded protein carries a predicted thioredoxin fold and deletion of the gene also results in increased sensitivity to hydrogen peroxide and cumene hydroperoxide. We have designated the gene srlA (stress resistance locus A) based on these phenotypes. A deletion mutant yields phenotypic revertants on high salt medium and genome sequencing revealed that all revertants carry a mutation in genes homologous to either cenK or cenR. srlA promoter activity is abolished in these revertant host backgrounds and in a strain carrying a deletion in cenK. We also observed that the srlA promoter is autoregulated, displaying low activity in a wildtype (wt) host background and high activity in the srl deletion mutant background. The srlA promoter includes a conserved inverted repeat directly upstream of the predicted -35 subsequence. A mutational analysis demonstrated that the site is required for the high promoter activity in the srlA deletion background. Electromobility shift assays using purified wildtype CenR response regulator and a D55E phosphomimetic derivative suggest this protein acts as a likely Class II activator by binding promoter DNA. These results document the first identified CenK-CenR regulon member in S. meliloti and demonstrate this two-component regulatory system and gene srlA influences cellular growth and persistence under certain stress-inducing conditions.}, }
@article {pmid36244047, year = {2022}, author = {Grostieta, E and Zazueta-Islas, HM and Cruz-Valdez, T and Ballados-González, GG and Álvarez-Castillo, L and García-Esparza, SM and Cruz-Romero, A and Romero-Salas, D and Aguilar-Domínguez, M and Becker, I and Sánchez-Montes, S}, title = {Molecular detection of Coxiella-like endosymbionts and absence of Coxiella burnetii in Amblyomma mixtum from Veracruz, Mexico.}, journal = {Experimental &amp; applied acarology}, volume = {88}, number = {1}, pages = {113-125}, pmid = {36244047}, issn = {1572-9702}, mesh = {Humans ; Animals ; Cattle ; Horses ; *Coxiella burnetii/genetics ; Coxiella/genetics ; *Q Fever/veterinary ; Amblyomma ; Phylogeny ; Mexico ; *Ticks ; Livestock ; *Cattle Diseases ; *Horse Diseases ; }, abstract = {Ticks are obligate ectoparasites associated with a wide range of vertebrate hosts, including domestic animals. Moreover, ticks are capable of transmitting many pathogens such as Coxiella. To date, Coxiella burnetii, the etiological agent of coxiellosis or Q fever, is the only valid species of the genera. Nevertheless, a wide range of agents denominated Coxiella-like have been detected in recent studies, mainly associated with ticks. The pathogenicity of these Coxiella-like agents is controversial as some of them can infect both birds and humans. In Mexico, knowledge about Q fever is scarce and limited to historical serological records, and there is an overall lack of molecular proof of any agent of the genus Coxiella circulating in the country. Therefore, the aim of this study was to detect the presence of Coxiella in ticks associated with cattle in all 10 regions of Veracruz, Mexico. To accomplish this objective, first, we identified ticks collected from cattle and horses in Veracruz. Then, for Coxiella detection, DNA extraction from ticks and PCR amplification of the 16S-rDNA of Coxiella was performed. Finally, we performed a phylogenetic reconstruction to determine the Coxiella lineages detected. From the 10 regions sampled we collected 888 ticks grouped in 180 pools, and only five Amblyomma mixtum from the locality of Castán, and one from Los Angeles from Tuxpan were found positive, which represents a frequency of 20% for each locality. This study represents the first attempt at molecular detection of Coxiella in ticks associated with cattle in the state of Veracruz, the major livestock producer in the country. The findings of the present study are relevant as they establish a precedent regarding the circulation of Coxiella-like agents, as well as the absence in three municipalities of the state of Veracruz of C. burnetii, an abortive agent of livestock importance.}, }
@article {pmid36240631, year = {2022}, author = {Ip, JC and Zhang, Y and Xie, JY and Yeung, YH and Qiu, JW}, title = {Stable Symbiodiniaceae composition in three coral species during the 2017 natural bleaching event in subtropical Hong Kong.}, journal = {Marine pollution bulletin}, volume = {184}, number = {}, pages = {114224}, doi = {10.1016/j.marpolbul.2022.114224}, pmid = {36240631}, issn = {1879-3363}, mesh = {Animals ; *Anthozoa ; Coral Reefs ; Hong Kong ; *Dinoflagellida ; Symbiosis ; }, abstract = {Adaptive changes in endosymbiotic Symbiodiniaceae communities have been reported during and after bleaching events in tropical coral species, but little is known about such shifts in subtropical species. Here we examined the Symbiodiniaceae communities in three coral species (Montipora peltiformis, Pavona decussata, and Platygyra carnosa) based on samples collected during and after the 2017 bleaching event in subtropical Hong Kong waters. In all of the collected samples, ITS2 meta-sequencing revealed that P. decussata and P. carnosa were predominantly associated with Cladocopium C1 and C1c, whereas M. peltiformis was mainly associated with two Cladocopium C21 types and C1. For each species, the predominant endosymbionts exhibited high fidelity, and the relatively low abundance ITS2-types showed minor changes between the bleached and recovered corals. Our study provided the first details of coral-algal association in Hong Kong waters, suggesting the selection of certain genotypes as a potential adaptive mechanism to the marginal environmental conditions.}, }
@article {pmid36217008, year = {2022}, author = {Brumfield, KD and Raupp, MJ and Haji, D and Simon, C and Graf, J and Cooley, JR and Janton, ST and Meister, RC and Huq, A and Colwell, RR and Hasan, NA}, title = {Gut microbiome insights from 16S rRNA analysis of 17-year periodical cicadas (Hemiptera: Magicicada spp.) Broods II, VI, and X.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {16967}, pmid = {36217008}, issn = {2045-2322}, support = {R01ES030317A/NH/NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics ; *Gastrointestinal Microbiome/genetics ; *Hemiptera/genetics ; RNA, Ribosomal, 16S/genetics ; Soil ; United States ; }, abstract = {Periodical cicadas (Hemiptera: Magicicada) have coevolved with obligate bacteriome-inhabiting microbial symbionts, yet little is known about gut microbial symbiont composition or differences in composition among allochronic Magicicada broods (year classes) which emerge parapatrically or allopatrically in the eastern United States. Here, 16S rRNA amplicon sequencing was performed to determine gut bacterial community profiles of three periodical broods, including II (Connecticut and Virginia, 2013), VI (North Carolina, 2017), and X (Maryland, 2021, and an early emerging nymph collected in Ohio, 2017). Results showed similarities among all nymphal gut microbiomes and between morphologically distinct 17-year Magicicada, namely Magicicada septendecim (Broods II and VI) and 17-year Magicicada cassini (Brood X) providing evidence of a core microbiome, distinct from the microbiome of burrow soil inhabited by the nymphs. Generally, phyla Bacteroidetes [Bacteroidota] (> 50% relative abundance), Actinobacteria [Actinomycetota], or Proteobacteria [Pseudomonadota] represented the core. Acidobacteria and genera Cupriavidus, Mesorhizobium, and Delftia were prevalent in nymphs but less frequent in adults. The primary obligate endosymbiont, Sulcia (Bacteroidetes), was dominant amongst core genera detected. Chryseobacterium were common in Broods VI and X. Chitinophaga, Arthrobacter, and Renibacterium were common in Brood X, and Pedobacter were common to nymphs of Broods II and VI. Further taxonomic assignment of unclassified Alphaproteobacteria sequencing reads allowed for detection of multiple copies of the Hodgkinia 16S rRNA gene, distinguishable as separate operational taxonomic units present simultaneously. As major emergences of the broods examined here occur at 17-year intervals, this study will provide a valuable comparative baseline in this era of a changing climate.}, }
@article {pmid36214563, year = {2022}, author = {Zhou, JC and Zhao, X and Huo, LX and Shang, D and Dong, H and Zhang, LS}, title = {Wolbachia-Driven Memory Loss in a Parasitic Wasp Increases Superparasitism to Enhance Horizontal Transmission.}, journal = {mBio}, volume = {}, number = {}, pages = {e0236222}, doi = {10.1128/mbio.02362-22}, pmid = {36214563}, issn = {2150-7511}, abstract = {Horizontal transmission of the endosymbiont, Wolbachia, may occur during superparasitism when parasitoid females deposit a second clutch of eggs on a host. Wolbachia may increase the superparasitism tendency of Trichogramma wasps by depriving their memory. To test this hypothesis, we investigated the effects of conditioning experience and memory inhibitors (actinomycin D [ACD] and anisomycin [ANI]) on memory capacity, and expressions of memory-related genes (CREB1 and PKA), and superparasitism frequency of Wolbachia-infected (TDW) and uninfected (TD) lines of Trichogramma dendrolimi after conditioning with lemon or peppermint odor. We detected the presence of Wolbachia in eggs, larvae, pre-pupae, pupae, and adults of Trichogramma by using fluorescence in situ hybridization. The results showed that TDW females had a more reduced memory capacity than TD females after conditioning. Compared with TD females, TDW females showed a higher proportion of superparasitism and a downregulation of CREB1 and PKA genes after conditioning. TD females fed ACD or ANI showed a higher tendency for superparasitism and a downregulation of CREB1 and PKA, along with memory loss after conditioning than TD females fed honey solution only. The presence of Wolbachia was detected in the anterior region of the larva, pre-pupa, and pupa, but was not found in the head of the adult. The results provide evidence of host behavioral manipulation of Wolbachia by depriving memory of host Trichogramma wasps based on Poulin' s criteria. These host behavioral changes led by Wolbachia may be caused by the virulence of Wolbachia on the nervous system of the host. IMPORTANCE The endosymbiotic bacteria, Wolbachia, live widely within cells of arthropods. Wolbachia are not only transmitted vertically from host mother to offspring, but are also transmitted horizontally among host individuals. Horizontal transmission is expected to occur during superparasitism when host parasitoid females deposit a clutch of eggs on a host previously parasitized by the same parasitoid species. Thus, a question is proposed regarding whether superparasitism behavior is a behavior modification induced by the symbiont to favor symbiont transmission. This study highlights behavioral mechanisms of Wolbachia-induced superparasitism in Trichogramma wasps and the manipulation of symbionts on host parasitoids.}, }
@article {pmid36209116, year = {2022}, author = {Kim, JI and Tanifuji, G and Jeong, M and Shin, W and Archibald, JM}, title = {Gene loss, pseudogenization, and independent genome reduction in non-photosynthetic species of Cryptomonas (Cryptophyceae) revealed by comparative nucleomorph genomics.}, journal = {BMC biology}, volume = {20}, number = {1}, pages = {227}, pmid = {36209116}, issn = {1741-7007}, mesh = {*Cryptophyta/genetics ; *Genome ; Genomics ; Photosynthesis ; Phylogeny ; Plastids/genetics ; }, abstract = {BACKGROUND: Cryptophytes are ecologically important algae of interest to evolutionary cell biologists because of the convoluted history of their plastids and nucleomorphs, which are derived from red algal secondary endosymbionts. To better understand the evolution of the cryptophyte nucleomorph, we sequenced nucleomorph genomes from two photosynthetic and two non-photosynthetic species in the genus Cryptomonas. We performed a comparative analysis of these four genomes and the previously published genome of the non-photosynthetic species Cryptomonas paramecium CCAP977/2a.<br><br>RESULTS: All five nucleomorph genomes are similar in terms of their general architecture, gene content, and gene order and, in the non-photosynthetic strains, loss of photosynthesis-related genes. Interestingly, in terms of size and coding capacity, the nucleomorph genome of the non-photosynthetic species Cryptomonas sp. CCAC1634B is much more similar to that of the photosynthetic C. curvata species than to the non-photosynthetic species C. paramecium.<br><br>CONCLUSIONS: Our results reveal fine-scale nucleomorph genome variation between distantly related congeneric taxa containing photosynthetic and non-photosynthetic species, including recent pseudogene formation, and provide a first glimpse into the possible impacts of the loss of photosynthesis on nucleomorph genome coding capacity and structure in independently evolved colorless strains.}, }
@article {pmid36205078, year = {2022}, author = {Iwata, M and Yoshinaga, M and Mizutani, K and Kikawada, T and Kikuta, S}, title = {Proton gradient mediates hemolymph trehalose influx into aphid bacteriocytes.}, journal = {Archives of insect biochemistry and physiology}, volume = {}, number = {}, pages = {e21971}, doi = {10.1002/arch.21971}, pmid = {36205078}, issn = {1520-6327}, abstract = {Aphids harbor proteobacterial endosymbionts such as Buchnera aphidicola housed in specialized bacteriocytes derived from host cells. The endosymbiont Buchnera supplies essential amino acids such as arginine to the host cells and, in turn, obtains sugars needed for its survival from the hemolymph. The mechanism of sugar supply in aphid bacteriocytes has been rarely studied. It also remains unclear how Buchnera acquires its carbon source. The hemolymph sugars in Acyrthosiphon pisum are composed of the disaccharide trehalose containing two glucose molecules. Here, we report for the first time that trehalose is transported and used as a potential carbon source by Buchnera across the bacteriocyte plasma membrane via trehalose transporters. The current study characterized the bacteriocyte trehalose transporter Ap_ST11 (LOC100159441) using the Xenopus oocyte expression system. The Ap_ST11 transporter was found to be proton-dependent with a Km value ≥700 mM. We re-examined the hemolymph trehalose at 217.8 mM using a fluorescent trehalose sensor. The bacteriocytes did not obtain trehalose by facilitated diffusion along the gradient across cellular membranes. These findings suggest that trehalose influx into the bacteriocytes depends on the extracellular proton-driven secondary electrochemical transporter.}, }
@article {pmid36194551, year = {2022}, author = {Gäbelein, CG and Reiter, MA and Ernst, C and Giger, GH and Vorholt, JA}, title = {Engineering Endosymbiotic Growth of E. coli in Mammalian Cells.}, journal = {ACS synthetic biology}, volume = {11}, number = {10}, pages = {3388-3396}, pmid = {36194551}, issn = {2161-5063}, mesh = {Animals ; Humans ; *Symbiosis ; *Escherichia coli/genetics ; HeLa Cells ; Biological Evolution ; Bacteria ; Amino Acids, Aromatic ; Mammals ; }, abstract = {Endosymbioses are cellular mergers in which one cell lives within another cell and have led to major evolutionary transitions, most prominently to eukaryogenesis. Generation of synthetic endosymbioses aims to provide a defined starting point for studying fundamental processes in emerging endosymbiotic systems and enable the engineering of cells with novel properties. Here, we tested the potential of different bacteria for artificial endosymbiosis in mammalian cells. To this end, we adopted the fluidic force microscopy technology to inject diverse bacteria directly into the cytosol of HeLa cells and examined the endosymbiont-host interactions by real-time fluorescence microscopy. Among them, Escherichia coli grew exponentially within the cytoplasm, however, at a faster pace than its host cell. To slow down the intracellular growth of E. coli, we introduced auxotrophies in E. coli and demonstrated that the intracellular growth rate can be reduced by limiting the uptake of aromatic amino acids. In consequence, the survival of the endosymbiont-host pair was prolonged. The presented experimental framework enables studying endosymbiotic candidate systems at high temporal resolution and at the single cell level. Our work represents a starting point for engineering a stable, vertically inherited endosymbiosis.}, }
@article {pmid36192976, year = {2022}, author = {Morales-Quintana, L and Miño, R and Mendez-Yañez, A and Gundel, PE and Ramos, P}, title = {Do fungal-endosymbionts improve crop nutritional quality and tolerance to stress by boosting flavonoid-mediated responses?.}, journal = {Food research international (Ottawa, Ont.)}, volume = {161}, number = {}, pages = {111850}, doi = {10.1016/j.foodres.2022.111850}, pmid = {36192976}, issn = {1873-7145}, mesh = {*Antioxidants ; Endophytes/physiology ; *Flavonoids ; Humans ; Nutritive Value ; Plants ; Symbiosis ; }, abstract = {Climate change is threatening human activities, but the combination of water scarcity and heat waves are particularly challenging agriculture. Accumulating literature shows that beneficial fungal endophytes improve plant performance, a condition that seems to be magnified in presence of stress. Because evidence points out to an endophytic mediation of antioxidant activity in plants, we here focused on flavonoids for two main reasons: (i) they are involved in plant tolerance to abiotic stress, and (ii) they are known to be healthy for human consumption. With these two premises as guidance, we explored the literature trying to link mechanistically the relationship between endophytes and plant responses to stress as well as identifying patterns and knowledge gaps. Overall, fungal endophytes improve plant growth and tolerance to environmental stresses. However, evidence for endophytes boosting flavonoid mediated responses in plants is relatively scarce. Reports showing endophytes promoting flavonoid contents in grains and fresh fruits are rather limited which may be related to (long) length of the required experiments for testing it. The use of endophytes isolated from extreme environments (e.g., dry and cold deserts, acid lakes, etc.) is proposed to be better in conferring tolerance to plants under very stressful conditions. However, the real challenge is to test the capacity of these endophytes to established and maintain persistent and functional symbiosis under productive conditions. In summary, there is a clear potential for symbiotically modifying crop plants as a strategy to develop more tolerant varieties to face the stress and eventually increase the quality of the agricultural products.}, }
@article {pmid36179855, year = {2022}, author = {Ünal, M and Yüksel, E and Canhilal, R}, title = {Biocontrol potential of cell suspensions and cell-free superntants of different Xenorhabdus and Photorhabdus bacteria against the different larval instars of Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae).}, journal = {Experimental parasitology}, volume = {242}, number = {}, pages = {108394}, doi = {10.1016/j.exppara.2022.108394}, pmid = {36179855}, issn = {1090-2449}, mesh = {Animals ; Humans ; Larva/microbiology ; *Xenorhabdus ; *Photorhabdus ; *Insecticides ; *Moths ; Sugars ; Pest Control, Biological/methods ; }, abstract = {The black cutworm (BCW), Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), is one of the destructive cutworm species. Black cutworm is a highly polyphagous pest that feeds on more than 30 plants, many of which are of economic importance such as maize, sugar beet, and potato. The control of BCW larvae relies heavily on the application of synthetic insecticides which have a detrimental impact on human health and the natural environment. In addition, increasing insecticide resistance in many insect species requires a novel and sustainable approach to controlling insect pests. The endosymbionts of entomopathogenic nematodes (EPNs) (Xenorhabdus and Phorohabdus spp.) represent a newly emerging green approach to controlling a wide range of insect pests. In the current study, the oral and contact efficacy of cell suspension (4 × 10[7] cells ml[-1]) and cell-free supernatants of different symbiotic bacteria (X. nematophilai, X. bovienii, X. budapestensis, and P. luminescent subsp. kayaii) were evaluated against the mixed groups of 1st-2nd and 3rd-4th instars larvae of BCW under controlled conditions. The oral treatment of the cell suspension and cell-free supernatants resulted in higher mortality rates than contact treatments. In general, larval mortality was higher in the 1st-2nd instar larvae than in the 3rd-4th instar larvae. The highest (75%) mortality was obtained from the cell suspension of X. budapestensis. The results indicated that the oral formulations of the cell suspension and cell-free supernatants of bacterial strains may have a good control potential against the 1st-2nd larvae BCW. However, the efficacy of the cell suspension and cell-free supernatants of tested bacterial strains should be further evaluated under greenhouse and field conditions.}, }
@article {pmid36175838, year = {2022}, author = {Rayamajhee, B and Sharma, S and Willcox, M and Henriquez, FL and Rajagopal, RN and Shrestha, GS and Subedi, D and Bagga, B and Carnt, N}, title = {Assessment of genotypes, endosymbionts and clinical characteristics of Acanthamoeba recovered from ocular infection.}, journal = {BMC infectious diseases}, volume = {22}, number = {1}, pages = {757}, pmid = {36175838}, issn = {1471-2334}, mesh = {*Acanthamoeba/genetics ; *Acanthamoeba Keratitis ; *Disinfectants ; *Eye Infections ; Genotype ; Humans ; In Situ Hybridization, Fluorescence ; Retrospective Studies ; }, abstract = {INTRODUCTION: Acanthamoeba is an emerging pathogen, infamous for its resilience against antiprotozoal compounds, disinfectants and harsh environments. It is known to cause keratitis, a sight-threatening, painful and difficult to treat corneal infection which is often reported among contact lens wearers and patients with ocular trauma. Acanthamoeba comprises over 24 species and currently 23 genotypes (T1-T23) have been identified.<br><br>AIMS: This retrospective study was designed to examine the Acanthamoeba species and genotypes recovered from patients with Acanthamoeba keratitis (AK), determine the presence of endosymbionts in ocular isolates of Acanthamoeba and review the clinical presentations.<br><br>METHODOLOGY: Thirteen culture-confirmed AK patients treated in a tertiary eye care facility in Hyderabad, India from February to October 2020 were included in this study. The clinical manifestations, medications and visual outcomes of all patients were obtained from medical records. The Acanthamoeba isolates were identified by sequencing the ribosomal nuclear subunit (rns) gene. Acanthamoeba isolates were assessed for the presence of bacterial or fungal endosymbionts using molecular assays, PCR and fluorescence in situ hybridization (FISH).<br><br>RESULTS: The mean age of the patients was 33&#xa0;years (SD&#x2009;&#xb1;&#x2009;17.4; 95% CI 22.5 to 43.5&#xa0;years). Six (46.2%) cases had AK associated risk factors; four patients had ocular trauma and two were contact lens wearers. A. culbertsoni (6/13, 46.2%) was the most common species, followed by A. polyphaga and A. triangularis. Most of the isolates (12/13) belonged to genotype T4 and one was a T12; three sub-clusters T4A, T4B, and T4F were identified within the T4 genotype. There was no significant association between Acanthamoeba types and clinical outcomes. Eight (61.5%) isolates harboured intracellular bacteria and one contained Malassezia restricta. The presence of intracellular microbes was associated with a higher proportion of stromal infiltrates (88.9%, 8/9), epithelial defect (55.6%, 5/9) and hypopyon (55.6%, 5/9) compared to 50% (2/4), 25% (1/4) and 25% (1/4) AK cases without intracellular microbes, respectively.<br><br>CONCLUSIONS: Genotype T4 was the predominant isolate in southern India. This is the second report of T12 genotype identified from AK patient in India, which is rarely reported worldwide. The majority of the Acanthamoeba clinical isolates in this study harboured intracellular microbes, which may impact clinical characteristics of AK.}, }
@article {pmid36172550, year = {2022}, author = {Wu, D and Yang, L and Gu, J and Tarkowska, D and Deng, X and Gan, Q and Zhou, W and Strnad, M and Lu, Y}, title = {A Functional Genomics View of Gibberellin Metabolism in the Cnidarian Symbiont Breviolum minutum.}, journal = {Frontiers in plant science}, volume = {13}, number = {}, pages = {927200}, pmid = {36172550}, issn = {1664-462X}, abstract = {Dinoflagellate inhabitants of the reef-building corals exchange nutrients and signals with host cells, which often benefit the growth of both partners. Phytohormones serve as central hubs for signal integration between symbiotic microbes and their hosts, allowing appropriate modulation of plant growth and defense in response to various stresses. However, the presence and function of phytohormones in photosynthetic dinoflagellates and their function in the holobionts remain elusive. We hypothesized that endosymbiotic dinoflagellates may produce and employ phytohormones for stress responses. Using the endosymbiont of reef corals Breviolum minutum as model, this study aims to exam whether the alga employ analogous signaling systems by an integrated multiomics approach. We show that key gibberellin (GA) biosynthetic genes are widely present in the genomes of the selected dinoflagellate algae. The non-13-hydroxylation pathway is the predominant route for GA biosynthesis and the multifunctional GA dioxygenase in B. minutum has distinct substrate preference from high plants. GA biosynthesis is modulated by the investigated bleaching-stimulating stresses at both transcriptional and metabolic levels and the exogenously applied GAs improve the thermal tolerance of the dinoflagellate. Our results demonstrate the innate ability of a selected Symbiodiniaceae to produce the important phytohormone and the active involvement of GAs in the coordination and the integration of the stress response.}, }
@article {pmid36172295, year = {2022}, author = {Tiwary, A and Babu, R and Sen, R and Raychoudhury, R}, title = {Bacterial supergroup-specific "cost" of Wolbachia infections in Nasonia vitripennis.}, journal = {Ecology and evolution}, volume = {12}, number = {9}, pages = {e9219}, pmid = {36172295}, issn = {2045-7758}, abstract = {The maternally inherited endosymbiont, Wolbachia, is known to alter the reproductive biology of its arthropod hosts for its own benefit and can induce both positive and negative fitness effects in many hosts. Here, we describe the effects of the maintenance of two distinct Wolbachia infections, one each from supergroups A and B, on the parasitoid host Nasonia vitripennis. We compare the effect of Wolbachia infections on various traits between the uninfected, single A-infected, single B-infected, and double-infected lines with their cured versions. Contrary to some previous reports, our results suggest that there is a significant cost associated with the maintenance of Wolbachia infections where traits such as family size, fecundity, longevity, and rates of male copulation are compromised in Wolbachia-infected lines. The double Wolbachia infection has the most detrimental impact on the host as compared to single infections. Moreover, there is a supergroup-specific negative impact on these wasps as the supergroup B infection elicits the most pronounced negative effects. These negative effects can be attributed to a higher Wolbachia titer seen in the double and the single supergroup B infection lines when compared to supergroup A. Our findings raise important questions on the mechanism of survival and maintenance of these reproductive parasites in arthropod hosts.}, }
@article {pmid36169529, year = {2022}, author = {Favoreto, AL and Carvalho, VR and Domingues, MM and Ribeiro, MF and Cavallini, G and Lawson, SA and Silva, WM and Zanuncio, JC and Wilcken, CF}, title = {Wolbachia pipientis: first detection in populations of Glycaspis brimblecombei (Hemiptera: Aphalaridae) and Psyllaephagus bliteus (Hymenoptera: Encyrtidae) in Brazil.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {82}, number = {}, pages = {e264475}, doi = {10.1590/1519-6984.264475}, pmid = {36169529}, issn = {1678-4375}, mesh = {Animals ; Brazil ; *Eucalyptus ; *Hemiptera ; Humans ; *Hymenoptera ; *Wolbachia ; }, abstract = {The sucking insect, Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae), is originally from Australia and reduces the productivity of Eucalyptus crops. The parasitoid Psyllaephagus bliteus Riek (Hymenoptera: Encyrtidae) is the main agent used in the integrated management of G. brimblecombei. Endosymbionts, in insects, are important in the adaptation and protection of their hosts to the environment. The intracellular symbionts Wolbachia, induces reproductive changes such as cytoplasmic incompatibility, feminization, male death and parthenogenesis. The objective of this study was to report the first record of Wolbachia pipientis in populations of G. brimblecombei and of its parasitoid P. bliteus in the field in Brazil. Branches with adults of G. brimblecombei and P. bliteus were collected from eucalyptus trees in commercial farms in six Brazilian states and, after emergence, the insects obtained were frozen at -20 °C. Polymerase chain reaction (PCR) was performed to detect the Wolbachia endosymbiont. Wolbachia pipientis was identified in individuals of G. brimblecombei and its parasitoid P. bliteus from populations of the counties of Agudos and Mogi-Guaçu (São Paulo State), Itamarandiba (Minas Gerais State) and São Jerônimo da Serra (Paraná State) in Brazil.}, }
@article {pmid36163269, year = {2022}, author = {Ferrarini, MG and Dell'Aglio, E and Vallier, A and Balmand, S and Vincent-Monégat, C and Hughes, S and Gillet, B and Parisot, N and Zaidman-Rémy, A and Vieira, C and Heddi, A and Rebollo, R}, title = {Efficient compartmentalization in insect bacteriomes protects symbiotic bacteria from host immune system.}, journal = {Microbiome}, volume = {10}, number = {1}, pages = {156}, pmid = {36163269}, issn = {2049-2618}, mesh = {Animals ; Bacteria ; Immune System ; Insect Proteins ; *Peptidoglycan ; Symbiosis ; *Weevils/microbiology ; }, abstract = {BACKGROUND: Many insects house symbiotic intracellular bacteria (endosymbionts) that provide them with essential nutrients, thus promoting the usage of nutrient-poor habitats. Endosymbiont seclusion within host specialized cells, called bacteriocytes, often organized in a dedicated organ, the bacteriome, is crucial in protecting them from host immune defenses while avoiding chronic host immune activation. Previous evidence obtained in the cereal weevil Sitophilus oryzae has shown that bacteriome immunity is activated against invading pathogens, suggesting endosymbionts might be targeted and impacted by immune effectors during an immune challenge. To pinpoint any molecular determinants associated with such challenges, we conducted a dual transcriptomic analysis of S. oryzae's bacteriome subjected to immunogenic peptidoglycan fragments.<br><br>RESULTS: We show that upon immune challenge, the bacteriome actively participates in the innate immune response via induction of antimicrobial peptides (AMPs). Surprisingly, endosymbionts do not undergo any transcriptomic changes, indicating that this potential threat goes unnoticed. Immunohistochemistry showed that TCT-induced AMPs are located outside the bacteriome, excluding direct contact with the endosymbionts.<br><br>CONCLUSIONS: This work demonstrates that endosymbiont protection during an immune challenge is mainly achieved by efficient confinement within bacteriomes, which provides physical separation between host systemic response and endosymbionts. Video Abstract.}, }
@article {pmid36160860, year = {2022}, author = {An, L and Bhowmick, B and Liang, D and Suo, P and Liao, C and Zhao, J and Han, Q}, title = {The microbiota changes of the brown dog tick, Rhipicephalus sanguineus under starvation stress.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {932130}, pmid = {36160860}, issn = {1664-042X}, abstract = {Rhipicephalus sanguineus, the brown dog tick, is the most widespread tick in the world and a predominant vector of multiple pathogens affecting wild and domestic animals. There is an increasing interest in understanding the role of tick microbiome in pathogen acquisition and transmission as well as in environment-vector interfaces. Several studies suggested that the tick microbial communities are under the influence of several factors including the tick species, dietary bloodmeal, and physiological stress. Compared with insects, very little of the microbial community is known to contribute to the nutrition of the host. Therefore, it is of significance to elucidate the regulation of the microbial community of Rh. Sanguineus under starvation stress. Starvation stress was induced in wild-type adults (1 month, 2 months, 4 months, 6 months) and the microbial composition and diversity were analyzed before and after blood feeding. After the evaluation, it was found that the microbial community composition of Rh. sanguineus changed significantly with starvation stress. The dominant symbiotic bacteria Coxiella spp. of Rh. sanguineus gradually decreased with the prolongation of starvation stress. We also demonstrated that the starvation tolerance of Rh. sanguineus was as long as 6 months. Next, Coxiella-like endosymbionts were quantitatively analyzed by fluorescence quantitative PCR. We found a pronounced tissue tropism in the Malpighian tubule and female gonad, and less in the midgut and salivary gland organs. Finally, the blood-fed nymphs were injected with ofloxacin within 24 h. The nymphs were allowed to develop into adults. It was found that the adult blood-sucking rate, adult weight after blood meal, fecundity (egg hatching rate), and feeding period of the newly hatched larvae were all affected to varying degrees, indicating that the removal of most symbiotic bacteria had an irreversible effect on it.}, }
@article {pmid36156240, year = {2022}, author = {Bespalaya, YV and Sousa, R and Gofarov, MY and Kondakov, AV and Kropotin, AV and Palatov, DM and Vikhrev, IV and Bolotov, IN}, title = {An exploration of the hidden endosymbionts of Corbicula in the native range.}, journal = {Ecology}, volume = {}, number = {}, pages = {e3836}, doi = {10.1002/ecy.3836}, pmid = {36156240}, issn = {1939-9170}, }
@article {pmid36151951, year = {2022}, author = {Niu, R and Zhu, X and Wang, L and Zhang, K and Li, D and Ji, J and Niu, L and Gao, X and Luo, J and Cui, J}, title = {Evaluation of Hamiltonella on Aphis gossypii fitness based on life table parameters and RNA sequencing.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7200}, pmid = {36151951}, issn = {1526-4998}, abstract = {BACKGROUND: Insect endosymbionts are widespread in nature and known to play key roles in regulating host biology. As a secondary endosymbiont, bacteria in the genus Hamiltonella help cotton aphids (Aphis gossypii) defend against parasitism by parasitoid wasps, however, the potential negative impacts of these bacteria on cotton aphid biology remain largely unclear.<br><br>RESULTS: This study aims to evaluate the potential impacts of Hamiltonella on the growth and development of cotton aphids based on life table parameters and RNA sequencing. The results showed that infection with Hamiltonella resulted in smaller body type and lower body weight in aphids. Compared to the control group, there were significant differences in the finite and intrinsic rates of increase and mean generation time. Furthermore, the RNA sequencing data revealed that the genes related to energy synthesis and nutrient metabolism pathways were significantly downregulated and genes related to molting and nervous system pathways were significantly upregulated in the Hamiltonella population.<br><br>CONCLUSION: Our results confirm that Hamiltonella retarded the growth and development of cotton aphids accompanied by the downregulation of genes related to energy synthesis and nutrient metabolism, which provides new insights into aphid-symbiont interactions and may support the development of improved aphid management strategies. &#xa9; 2022 Society of Chemical Industry.}, }
@article {pmid36151871, year = {2022}, author = {Bing, XL and Xia, CB and Ye, QT and Gong, X and Cui, JR and Peng, CW and Hong, XY}, title = {Wolbachia manipulates reproduction of spider mites by influencing herbivore salivary proteins.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7201}, pmid = {36151871}, issn = {1526-4998}, abstract = {BACKGROUND: The endosymbiont Wolbachia is known for manipulating host reproduction. Wolbachia also can affect host fitness by mediating interactions between plant and herbivores. However, it remains unclear whether saliva proteins are involved in this process.<br><br>RESULTS: We found that Wolbachia infection decreased the number of deposited eggs but increased the egg hatching rate in the spider mite Tetranychus urticae Koch (Acari: Tetranychidae), a cosmopolitan pest that infects >1000 species of plants. Transcriptomic and proteomic analyses revealed that Wolbachia-infected mites upregulated the gene expression levels of many T.&#xa0;urticae salivary proteins including a cluster of Tetranychidae-specific, functionally uncharacterized SHOT1s (secreted host-responsive proteins of Tetranychidae). The SHOT1 genes were expressed more in the feeding stages (nymphs and adults) of mites than in eggs and highly enriched in the proterosomas. RNA interference experiments showed that knockdown of SHOT1s significantly decreased Wolbachia density, increased the number of deposited eggs and decreased the egg hatching rate.<br><br>CONCLUSION: Together, these results indicate that SHOT1s are positively correlated with Wolbachia density and account for Wolbachia-mediated phenotypes. Our results provide new evidence that herbivore salivary proteins are related to Wolbachia-mediated manipulations of host performance on plants. &#xa9; 2022 Society of Chemical Industry.}, }
@article {pmid36149408, year = {2022}, author = {Warecki, B and Titen, SWA and Alam, MS and Vega, G and Lemseffer, N and Hug, K and Minden, JS and Sullivan, W}, title = {Wolbachia action in the sperm produces developmentally deferred chromosome segregation defects during the Drosophila mid-blastula transition.}, journal = {eLife}, volume = {11}, number = {}, pages = {}, pmid = {36149408}, issn = {2050-084X}, support = {R35 GM139595/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Blastula ; Chromatin ; Chromosome Segregation ; Cytoplasm ; Drosophila/genetics ; Female ; In Situ Hybridization, Fluorescence ; Male ; Semen ; Spermatozoa ; *Wolbachia/genetics ; }, abstract = {Wolbachia, a vertically transmitted endosymbiont infecting many insects, spreads rapidly through uninfected populations by a mechanism known as cytoplasmic incompatibility (CI). In CI, a paternally delivered modification of the sperm leads to chromatin defects and lethality during and after the first mitosis of embryonic development in multiple species. However, whether CI-induced defects in later stage embryos are a consequence of the first division errors or caused by independent defects remains unresolved. To address this question, we focused on ~1/3 of embryos from CI crosses in Drosophila simulans that develop apparently normally through the first and subsequent pre-blastoderm divisions before exhibiting mitotic errors during the mid-blastula transition and gastrulation. We performed single embryo PCR and whole genome sequencing to find a large percentage of these developed CI-derived embryos bypass the first division defect. Using fluorescence in situ hybridization, we find increased chromosome segregation errors in gastrulating CI-derived embryos that had avoided the first division defect. Thus, Wolbachia action in the sperm induces developmentally deferred defects that are not a consequence of the first division errors. Like the immediate defect, the delayed defect is rescued through crosses to infected females. These studies inform current models on the molecular and cellular basis of CI.}, }
@article {pmid36143478, year = {2022}, author = {Johnson, KP}, title = {Genomic Approaches to Uncovering the Coevolutionary History of Parasitic Lice.}, journal = {Life (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, pmid = {36143478}, issn = {2075-1729}, abstract = {Next-generation sequencing technologies are revolutionizing the fields of genomics, phylogenetics, and population genetics. These new genomic approaches have been extensively applied to a major group of parasites, the lice (Insecta: Phthiraptera) of birds and mammals. Two louse genomes have been assembled and annotated to date, and these have opened up new resources for the study of louse biology. Whole genome sequencing has been used to assemble large phylogenomic datasets for lice, incorporating sequences of thousands of genes. These datasets have provided highly supported trees at all taxonomic levels, ranging from relationships among the major groups of lice to those among closely related species. Such approaches have also been applied at the population scale in lice, revealing patterns of population subdivision and inbreeding. Finally, whole genome sequence datasets can also be used for additional study beyond that of the louse nuclear genome, such as in the study of mitochondrial genome fragmentation or endosymbiont function.}, }
@article {pmid36143410, year = {2022}, author = {Johnston-Monje, D and Gutiérrez, JP and Becerra Lopez-Lavalle, LA}, title = {Stochastic Inoculum, Biotic Filtering and Species-Specific Seed Transmission Shape the Rare Microbiome of Plants.}, journal = {Life (Basel, Switzerland)}, volume = {12}, number = {9}, pages = {}, pmid = {36143410}, issn = {2075-1729}, abstract = {A plant's health and productivity is influenced by its associated microbes. Although the common/core microbiome is often thought to be the most influential, significant numbers of rare or uncommon microbes (e.g., specialized endosymbionts) may also play an important role in the health and productivity of certain plants in certain environments. To help identify rare/specialized bacteria and fungi in the most important angiosperm plants, we contrasted microbiomes of the seeds, spermospheres, shoots, roots and rhizospheres of Arabidopsis, Brachypodium, maize, wheat, sugarcane, rice, tomato, coffee, common bean, cassava, soybean, switchgrass, sunflower, Brachiaria, barley, sorghum and pea. Plants were grown inside sealed jars on sterile sand or farm soil. Seeds and spermospheres contained some uncommon bacteria and many fungi, suggesting at least some of the rare microbiome is vertically transmitted. About 95% and 86% of fungal and bacterial diversity inside plants was uncommon; however, judging by read abundance, uncommon fungal cells are about half of the mycobiome, while uncommon bacterial cells make up less than 11% of the microbiome. Uncommon-seed-transmitted microbiomes consisted mostly of Proteobacteria, Firmicutes, Bacteriodetes, Ascomycetes and Basidiomycetes, which most heavily colonized shoots, to a lesser extent roots, and least of all, rhizospheres. Soil served as a more diverse source of rare microbes than seeds, replacing or excluding the majority of the uncommon-seed-transmitted microbiome. With the rarest microbes, their colonization pattern could either be the result of stringent biotic filtering by most plants, or uneven/stochastic inoculum distribution in seeds or soil. Several strong plant-microbe associations were observed, such as seed transmission to shoots, roots and/or rhizospheres of Sarocladium zeae (maize), Penicillium (pea and Phaseolus), and Curvularia (sugarcane), while robust bacterial colonization from cassava field soil occurred with the cyanobacteria Leptolyngbya into Arabidopsis and Panicum roots, and Streptomyces into cassava roots. Some abundant microbes such as Sakaguchia in rice shoots or Vermispora in Arabidopsis roots appeared in no other samples, suggesting that they were infrequent, stochastically deposited propagules from either soil or seed (impossible to know based on the available data). Future experiments with culturing and cross-inoculation of these microbes between plants may help us better understand host preferences and their role in plant productivity, perhaps leading to their use in crop microbiome engineering and enhancement of agricultural production.}, }
@article {pmid36129743, year = {2022}, author = {Weiss, BL and Rio, RVM and Aksoy, S}, title = {Microbe Profile: Wigglesworthia glossinidia: the tsetse fly's significant other.}, journal = {Microbiology (Reading, England)}, volume = {168}, number = {9}, pages = {}, doi = {10.1099/mic.0.001242}, pmid = {36129743}, issn = {1465-2080}, mesh = {Amidohydrolases/metabolism ; Animals ; Antiparasitic Agents/metabolism ; Symbiosis ; *Tsetse Flies/parasitology/physiology ; Vitamins/metabolism ; *Wigglesworthia/metabolism ; }, abstract = {Wigglesworthia glossinidia is an obligate, maternally transmitted endosymbiont of tsetse flies. The ancient association between these two organisms accounts for many of their unique physiological adaptations. Similar to other obligate mutualists, Wigglesworthia's genome is dramatically reduced in size, yet it has retained the capacity to produce many B-vitamins that are found at inadequate quantities in the fly's vertebrate blood-specific diet. These Wigglesworthia-derived B-vitamins play essential nutritional roles to maintain tsetse's physiological homeostasis as well as that of other members of the fly's microbiota. In addition to its nutritional role, Wigglesworthia contributes towards the development of tsetse's immune system during the larval period. Tsetse produce amidases that degrade symbiotic peptidoglycans and prevent activation of antimicrobial responses that can damage Wigglesworthia. These amidases in turn exhibit antiparasitic activity and decrease tsetse's ability to be colonized with parasitic trypanosomes, which reduce host fitness. Thus, the Wigglesworthia symbiosis represents a fine-tuned association in which both partners actively contribute towards achieving optimal fitness outcomes.}, }
@article {pmid36125236, year = {2022}, author = {Brinker, P and Chen, F and Chehida, YB and Beukeboom, LW and Fontaine, MC and Salles, JF}, title = {Microbiome composition is shaped by geography and population structure in the parasitic wasp Asobara japonica, but not in the presence of the endosymbiont Wolbachia.}, journal = {Molecular ecology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mec.16699}, pmid = {36125236}, issn = {1365-294X}, abstract = {The microbial community composition is crucial for diverse life-history traits in many organisms. However, we still lack a sufficient understanding of how the host microbiome is acquired and maintained, a pressing issue in times of global environmental change. Here we investigated to what extent host genotype, environmental conditions, and the endosymbiont Wolbachia influence the bacterial communities in the parasitic wasp Asobara japonica. We sampled multiple wasp populations across 10 locations in their natural distribution range in Japan and sequenced the host genome (whole genome sequencing) and microbiome (16S rRNA gene). We compared the host population structure and bacterial community composition of wasps that reproduce sexually and are uninfected with Wolbachia with wasps that reproduce asexually and carry Wolbachia. The bacterial communities in asexual wasps were highly similar due to a strong effect of Wolbachia rather than host genomic structure. In contrast, in sexual wasps, bacterial communities appear primarily shaped by a combination of population structure and environmental conditions. Our research highlights that multiple factors shape the bacterial communities of an organism and that the presence of a single endosymbiont can strongly alter their compositions. This information is crucial to understanding how organisms and their associated microbiome will react in the face of environmental change.}, }
@article {pmid36124671, year = {2022}, author = {Brophy, M and Walker, KR and Adamson, JE and Ravenscraft, A}, title = {Tropical and Temperate Lineages of Rhipicephalus sanguineus s.l. Ticks (Acari: Ixodidae) Host Different Strains of Coxiella-like Endosymbionts.}, journal = {Journal of medical entomology}, volume = {59}, number = {6}, pages = {2022-2029}, doi = {10.1093/jme/tjac132}, pmid = {36124671}, issn = {1938-2928}, mesh = {Dogs ; Animals ; *Rhipicephalus sanguineus/genetics ; Coxiella/genetics ; *Ixodidae/microbiology ; RNA, Ribosomal, 16S/genetics ; Phylogeny ; Bacteria/genetics ; *Dog Diseases ; }, abstract = {Nonpathogenic bacteria likely play important roles in the biology and vector competence of ticks and other arthropods. Coxiella, a gram-negative gammaproteobacterium, is one of the most commonly reported maternally inherited endosymbionts in ticks and has been associated with over 40 tick species. Species-specific Coxiella-like endosymbionts (CLEs) have been reported in the brown dog tick, Rhipicephalus sanguineus sensu lato (Acari: Ixodidae), throughout the world, while recent research suggests low Coxiella diversity among tick species. We investigated CLE diversity among R. sanguineus s.l. ticks across Arizona. We detected 37 recurrent sequence variants (SVs) of the symbiont, indicating greater diversity in these symbiotic bacteria than previously reported. However, two SVs accounted for the vast majority of 16S rRNA amplicon reads. These two dominant CLEs were both closely related to Candidatus C. mudrowiae, an identified symbiont of Rhipicephalus turanicus ticks. One strain strongly associated with the tropical lineage of R. sanguineus s.l. while the other was found almost exclusively in the temperate lineage, supporting the conclusion that CLEs are primarily vertically transmitted. However, occasional mismatches between tick lineage and symbiont SV indicate that horizontal symbiont transfer may occur, perhaps via cofeeding of ticks from different lineages on the same dog. This study advances our understanding of CLE diversity in Rh. sanguineus s.l.}, }
@article {pmid36110209, year = {2022}, author = {Zhang, HD and Gao, J and Xing, D and Guo, XX and Li, CX and Dong, YD and Zheng, Z and Ma, Z and Wu, ZM and Zhu, XJ and Zhao, MH and Liu, QM and Yan, T and Chu, HL and Zhao, TY}, title = {Fine-scale genetic structure and wolbachia infection of aedes albopictus (Diptera: Culicidae) in Nanjing city, China.}, journal = {Frontiers in genetics}, volume = {13}, number = {}, pages = {827655}, pmid = {36110209}, issn = {1664-8021}, abstract = {Background: Aedes albopictus is an indigenous primary vector of dengue and Zika viruses in China. Wolbachia is a gram-negative and common intracellular bacteria, which is maternally inherited endosymbionts and could expand their propagation in host populations by means of various manipulations. Compared with research on the dispersion of Ae. albopictus at the macrospatial level (mainly at the country or continent level), little is known about its variation and Wolbachia infection at the microspatial level, which is essential for its management. Meanwhile, no local cases of dengue fever have been recorded in the history of Nanjing, which implies that few adulticides have been applied in the city. Thus, the present study examines how the Ae. albopictus population varies and the Wolbachia infection status of each population among microspatial regions of Nanjing City. Methods: The genetic structure of 17 Aedes albopictus populations collected from urban, urban fringe, and rural regions of Nanjing City was investigated based on 9 microsatellite loci and the mitochondrial coxI gene. The Wolbachia infection status of each population was also assessed with Wolbachia A- and Wolbachia B-specific primers. Results: Nine out of 58 tested pairs of microsatellite markers were highly polymorphic, with a mean PIC value of 0.560, and these markers were therefore chosen for microsatellite genotyping analysis. The Na value of each Ae. albopictus population was very high, and the urban area populations (7.353 ± 4.975) showed a lower mean value than the urban fringe region populations (7.866 ± 5.010). A total of 19 coxI haplotypes were observed among 329 Ae. albopictus individuals via haplotype genotyping, with the highest diversity observed among the urban fringe Ae. albopictus populations (Hd = 0.456) and the lowest among the urban populations (Hd = 0.277). Each Ae. albopictus population showed significant departure from HWE, and significant population expansion was observed in only three populations from the urban (ZSL), urban fringe (HAJY), and rural areas (HSZY) (p < 0.05). Combined with DAPC analysis, all the Ae. albopictus populations were adequately allocated to two clades with significant genetic differences according to population structure analysis, and the best K value was equal to two. AMOVA results showed that most (96.18%) of the genetic variation detected in Ae. albopictus occurred within individuals (FIT = 0.22238, p < 0.0001), while no significant positive correlation was observed via isolation by distance (IBD) analysis (R [2] = 0.03262, p = 0.584). The TCS network of all haplotypes showed that haplotype 1 (H1) and haplotype 4 (H4) were the most frequent haplotypes among all populations, and the haplotype frequency significantly increased from urban regions (36.84%) to rural regions (68.42%). Frequent migration was observed among Ae. albopictus populations from rural to urban regions via the urban fringe region, with four direct migration routes between rural and urban regions. Furthermore, Wolbachia genotyping results showed that most of the individuals of each population were coinfected with Wolbachia A and Wolbachia B. The independent infection rate of Wolbachia A was slightly higher than that of Wolbachia B, and no significant differences were observed among different regions. Conclusion: In the microspatial environment of Nanjing City, the urban fringe region is an important region for the dispersion of Ae. albopictus populations between rural and urban areas, and Wolbachia A and Wolbachia B coinfection is the most common Wolbachia infection status in all Ae. albopictus populations among different regions.}, }
@article {pmid36109147, year = {2022}, author = {Matthey-Doret, C and Colp, MJ and Escoll, P and Thierry, A and Moreau, P and Curtis, B and Sahr, T and Sarrasin, M and Gray, MW and Lang, BF and Archibald, JM and Buchrieser, C and Koszul, R}, title = {Chromosome-scale assemblies of Acanthamoeba castellanii genomes provide insights into Legionella pneumophila infection-related chromatin reorganization.}, journal = {Genome research}, volume = {32}, number = {9}, pages = {1698-1710}, pmid = {36109147}, issn = {1549-5469}, abstract = {The unicellular amoeba Acanthamoeba castellanii is ubiquitous in aquatic environments, where it preys on bacteria. The organism also hosts bacterial endosymbionts, some of which are parasitic, including human pathogens such as Chlamydia and Legionella spp. Here we report complete, high-quality genome sequences for two extensively studied A. castellanii strains, Neff and C3. Combining long- and short-read data with Hi-C, we generated near chromosome-level assemblies for both strains with 90% of the genome contained in 29 scaffolds for the Neff strain and 31 for the C3 strain. Comparative genomics revealed strain-specific functional enrichment, most notably genes related to signal transduction in the C3 strain and to viral replication in Neff. Furthermore, we characterized the spatial organization of the A. castellanii genome and showed that it is reorganized during infection by Legionella pneumophila Infection-dependent chromatin loops were found to be enriched in genes for signal transduction and phosphorylation processes. In genomic regions where chromatin organization changed during Legionella infection, we found functional enrichment for genes associated with metabolism, organelle assembly, and cytoskeleton organization. Given Legionella infection is known to alter its host's cell cycle, to exploit the host's organelles, and to modulate the host's metabolism in its favor, these changes in chromatin organization may partly be related to mechanisms of host control during Legionella infection.}, }
@article {pmid36100023, year = {2022}, author = {Brown, KT and Mello-Athayde, MA and Sampayo, EM and Chai, A and Dove, S and Barott, KL}, title = {Environmental memory gained from exposure to extreme pCO2 variability promotes coral cellular acid-base homeostasis.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1982}, pages = {20220941}, pmid = {36100023}, issn = {1471-2954}, mesh = {Animals ; *Anthozoa/physiology ; Ecosystem ; Homeostasis ; Hydrogen-Ion Concentration ; Seawater ; }, abstract = {Ocean acidification is a growing threat to coral growth and the accretion of coral reef ecosystems. Corals inhabiting environments that already endure extreme diel pCO2 fluctuations, however, may represent acidification-resilient populations capable of persisting on future reefs. Here, we examined the impact of pCO2 variability on the reef-building coral Pocillopora damicornis originating from reefs with contrasting environmental histories (variable reef flat versus stable reef slope) following reciprocal exposure to stable (218 ± 9) or variable (911 ± 31) diel pCO2 amplitude (μtam) in aquaria over eight weeks. Endosymbiont density, photosynthesis and net calcification rates differed between origins but not treatment, whereas primary calcification (extension) was affected by both origin and acclimatization to novel pCO2 conditions. At the cellular level, corals from the variable reef flat exhibited less intracellular pH (pHi) acidosis and faster pHi recovery rates in response to experimental acidification stress (pH 7.40) than corals originating from the stable reef slope, suggesting environmental memory gained from lifelong exposure to pCO2 variability led to an improved ability to regulate acid-base homeostasis. These results highlight the role of cellular processes in maintaining acidification resilience and suggest that prior exposure to pCO2 variability may promote more acidification-resilient coral populations in a changing climate.}, }
@article {pmid36099809, year = {2022}, author = {Dhali, S and Acharya, S and Pradhan, M and Patra, DK and Pradhan, C}, title = {Synergistic effect of Bacillus and Rhizobium on cytological and photosynthetic performance of Macrotyloma uniflorum (Lam.) Verdc. Grown in Cr (VI) contaminated soil.}, journal = {Plant physiology and biochemistry : PPB}, volume = {190}, number = {}, pages = {62-69}, doi = {10.1016/j.plaphy.2022.08.027}, pmid = {36099809}, issn = {1873-2690}, mesh = {*Bacillus ; Biodegradation, Environmental ; Chromium/pharmacology ; *Fabaceae/microbiology ; Photosynthesis ; Plant Roots ; *Rhizobium ; Soil ; *Soil Pollutants/analysis ; }, abstract = {Macrotyloma uniflorum (horse gram) is considered an under-utilized legume crop despite its nutritional and medicinal values. In India, it has wide acceptance among farming communities. This investigation emphasized on the possible application of two endosymbionts (Bacillus sp. AS03 and Rhizobium sp. AS05) of horse gram cultivated on Cr (VI)-contaminated soil. The photosynthetic performance (PIφ) of Cr treated plants co-inoculated with AS03 and AS05 was significantly improved compared with non-inoculated Cr treated plants based on photosynthetic yield, which was evidenced from the rise in the fluorescence at I-P transient and rate of photosynthesis (pN), indicating synergistic action between plant and bacteria (AS03 and AS05). The smooth electron transport from PS II to PS I was achieved in the Cr stressed plants inoculated with both the bacterial strains. The detrimental effects of Cr toxicity on the root tips were also minimized with bioinoculation as revealed from mitotic index. Plants with dual inoculation of AS03 and AS05 had significantly lesser chromosomal aberration in the roots. Dual inoculation biochar or seed inoculation have beneficial impact on the plant photosynthetic performance along with improved growth of roots in plants treated with Cr (VI). The results of the current work suggest the possitive effect of dual inoculation of Cr tolerant endosymbionts, Bacillus sp. (AS03) and nodulating Rhizobium sp. (AS05), in reducing cytological as well as physiological stress of plants in Cr (VI) contaminated soil.}, }
@article {pmid36098749, year = {2022}, author = {Angelella, G and Nalam, V and Nachappa, P and White, J and Kaplan, I}, title = {Correction to: Endosymbionts Differentially Alter Exploratory Probing Behavior of a Nonpersistent Plant Virus Vector.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, doi = {10.1007/s00248-022-02107-4}, pmid = {36098749}, issn = {1432-184X}, }
@article {pmid36094208, year = {2022}, author = {Kinjo, Y and Bourguignon, T and Hongoh, Y and Lo, N and Tokuda, G and Ohkuma, M}, title = {Coevolution of Metabolic Pathways in Blattodea and Their Blattabacterium Endosymbionts, and Comparisons with Other Insect-Bacteria Symbioses.}, journal = {Microbiology spectrum}, volume = {10}, number = {5}, pages = {e0277922}, pmid = {36094208}, issn = {2165-0497}, mesh = {Animals ; *Cockroaches/microbiology ; Genome, Bacterial ; Phylogeny ; Symbiosis ; Insecta ; Bacteria/genetics ; Metabolic Networks and Pathways/genetics ; Amino Acids ; Amino Acids, Essential/genetics ; Arginine/genetics ; Folic Acid ; Vitamins ; }, abstract = {Many insects harbor bacterial endosymbionts that supply essential nutrients and enable their hosts to thrive on a nutritionally unbalanced diet. Comparisons of the genomes of endosymbionts and their insect hosts have revealed multiple cases of mutually-dependent metabolic pathways that require enzymes encoded in 2 genomes. Complementation of metabolic reactions at the pathway level has been described for hosts feeding on unbalanced diets, such as plant sap. However, the level of collaboration between symbionts and hosts that feed on more variable diets is largely unknown. In this study, we investigated amino acid and vitamin/cofactor biosynthetic pathways in Blattodea, which comprises cockroaches and termites, and their obligate endosymbiont Blattabacterium cuenoti (hereafter Blattabacterium). In contrast to other obligate symbiotic systems, we found no clear evidence of "collaborative pathways" for amino acid biosynthesis in the genomes of these taxa, with the exception of collaborative arginine biosynthesis in 2 taxa, Cryptocercus punctulatus and Mastotermes darwiniensis. Nevertheless, we found that several gaps specific to Blattabacterium in the folate biosynthetic pathway are likely to be complemented by their host. Comparisons with other insects revealed that, with the exception of the arginine biosynthetic pathway, collaborative pathways for essential amino acids are only observed in phloem-sap feeders. These results suggest that the host diet is an important driving factor of metabolic pathway evolution in obligate symbiotic systems. IMPORTANCE The long-term coevolution between insects and their obligate endosymbionts is accompanied by increasing levels of genome integration, sometimes to the point that metabolic pathways require enzymes encoded in two genomes, which we refer to as "collaborative pathways". To date, collaborative pathways have only been reported from sap-feeding insects. Here, we examined metabolic interactions between cockroaches, a group of detritivorous insects, and their obligate endosymbiont, Blattabacterium, and only found evidence of collaborative pathways for arginine biosynthesis. The rarity of collaborative pathways in cockroaches and Blattabacterium contrasts with their prevalence in insect hosts feeding on phloem-sap. Our results suggest that host diet is a factor affecting metabolic integration in obligate symbiotic systems.}, }
@article {pmid36093053, year = {2022}, author = {Gabr, A and Stephens, TG and Bhattacharya, D}, title = {Loss of key endosymbiont genes may facilitate early host control of the chromatophore in Paulinella.}, journal = {iScience}, volume = {25}, number = {9}, pages = {104974}, pmid = {36093053}, issn = {2589-0042}, abstract = {The primary plastid endosymbiosis (∼124 Mya) that occurred in the heterotrophic amoeba lineage, Paulinella, is at an earlier stage of evolution than in Archaeplastida, and provides an excellent model for studying organelle integration. Using genomic data from photosynthetic Paulinella, we identified a plausible mechanism for the evolution of host control of endosymbiont (termed the chromatophore) biosynthetic pathways and functions. Specifically, random gene loss from the chromatophore and compensation by nuclear-encoded gene copies enables host control of key pathways through a minimal number of evolutionary innovations. These gene losses impact critical enzymatic steps in nucleotide biosynthesis and the more peripheral components of multi-protein DNA replication complexes. Gene retention in the chromatophore likely reflects the need to maintain a specific stoichiometric balance of the encoded products (e.g., involved in DNA replication) rather than redox state, as in the highly reduced plastid genomes of algae and plants.}, }
@article {pmid36085198, year = {2022}, author = {Medina, GA and Flores-Martin, SN and Pereira, WA and Figueroa, EG and Guzmán, NH and Letelier, PJ and Andaur, MR and Leyán, PI and Boguen, RE and Hernández, AH and Fernández, H}, title = {Long-term survive of Aliarcobacter butzleri in two models symbiotic interaction with Acanthamoeba castellanii.}, journal = {Archives of microbiology}, volume = {204}, number = {10}, pages = {610}, pmid = {36085198}, issn = {1432-072X}, mesh = {*Acanthamoeba castellanii/microbiology ; *Arcobacter ; Symbiosis ; }, abstract = {Aliarcobacter butzleri (formerly known as Arcobacter butzleri) is an emerging food-borne zoonotic pathogen that establishes in vitro endosymbiotic relationships with Acanthamoeba castellanii, a free-living amoeba. Previously, we described that this bacterium acts as an endocytobiont of A. castellanii, surviving for at least 10 days in absence of bacterial replication. Thus, the aim of this study was to evaluate the ability of A. butzleri to survive as a long-term endosymbiont of A. castellanii for 30 days in two models of symbiotic interaction with A. castellanii: (i) endosymbiotic culture followed by gentamicin protection assay and (ii) transwell co-culture assay. The results allow us to conclude that A. butzleri is capable of surviving as an endosymbiont of A. castellanii for at least 30 days, without multiplying, under controlled laboratory conditions. In addition, in the absence of nutrients and as both microorganisms remain in the same culture, separated by semi-permeable membranes, A. castellanii does not promote the survival of A. butzleri, nor does it multiply. Our findings suggest that the greater survival capacity of A. butzleri is associated with their endosymbiont status inside A. castellanii, pointing out the complexity of this type of symbiotic relationship.}, }
@article {pmid36054322, year = {2022}, author = {Štarhová Serbina, L and Gajski, D and Pafčo, B and Zurek, L and Malenovský, I and Nováková, E and Schuler, H and Dittmer, J}, title = {Microbiome of pear psyllids: A tale about closely related species sharing their endosymbionts.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16180}, pmid = {36054322}, issn = {1462-2920}, abstract = {Psyllids are phloem-feeding insects that can transmit plant pathogens such as phytoplasmas, intracellular bacteria causing numerous plant diseases worldwide. Their microbiomes are essential for insect physiology and may also influence the capacity of vectors to transmit pathogens. Using 16S rRNA gene metabarcoding, we compared the microbiomes of three sympatric psyllid species associated with pear trees in Central Europe. All three species are able to transmit 'Candidatus Phytoplasma pyri', albeit with different efficiencies. Our results revealed potential relationships between insect biology and microbiome composition that varied during psyllid ontogeny and between generations in Cacopsylla pyri and C. pyricola, as well as between localities in C. pyri. In contrast, no variations related to psyllid life cycle and geography were detected in C. pyrisuga. In addition to the primary endosymbiont Carsonella ruddii, we detected another highly abundant endosymbiont (unclassified Enterobacteriaceae). C. pyri and C. pyricola shared the same taxon of Enterobacteriaceae which is related to endosymbionts harboured by other psyllid species from various families. In contrast, C. pyrisuga carried a different Enterobacteriaceae taxon related to the genus Sodalis. Our study provides new insights into host-symbiont interactions in psyllids and highlights the importance of host biology and geography in shaping microbiome structure.}, }
@article {pmid36042402, year = {2022}, author = {Twort, VG and Blande, D and Duplouy, A}, title = {One's trash is someone else's treasure: sequence read archives from Lepidoptera genomes provide material for genome reconstruction of their endosymbionts.}, journal = {BMC microbiology}, volume = {22}, number = {1}, pages = {209}, pmid = {36042402}, issn = {1471-2180}, mesh = {Animals ; *Lepidoptera ; Phylogeny ; *Spiroplasma/genetics ; Symbiosis/genetics ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Maternally inherited bacterial symbionts are extremely widespread in insects. They owe their success to their ability to promote their own transmission through various manipulations of their hosts' life-histories. Many symbionts however very often go undetected. Consequently, we have only a restricted idea of the true symbiont diversity in insects, which may hinder our understanding of even bigger questions in the field such as the evolution or establishment of symbiosis.<br><br>RESULTS: In this study, we screened publicly available Lepidoptera genomic material for two of the most common insect endosymbionts, namely Wolbachia and Spiroplasma, in 1904 entries, encompassing 106 distinct species. We compared the performance of two screening software, Kraken2 and MetaPhlAn2, to identify the bacterial infections and using a baiting approach we reconstruct endosymbiont genome assemblies. Of the 106 species screened, 20 (19%) and nine (8.5%) were found to be infected with either Wolbachia or Spiroplasma, respectively. Construction of partial symbiotic genomes and phylogenetic analyses suggested the Wolbachia strains from the supergroup B were the most prevalent type of symbionts, while Spiroplasma infections were scarce in the Lepidoptera species screened here.<br><br>CONCLUSIONS: Our results indicate that many of the host-symbiont associations remain largely unexplored, with the majority of associations we identify never being recorded before. This highlights the usefulness of public databases to explore the hidden diversity of symbiotic entities, allowing the development of hypotheses regarding host-symbiont associations. The ever-expanding genomic databases provide a diverse databank from which one can characterize and explore the true diversity of symbiotic entities.}, }
@article {pmid36042324, year = {2022}, author = {Dharamshi, JE and Gaarslev, N and Steffen, K and Martin, T and Sipkema, D and Ettema, TJG}, title = {Genomic diversity and biosynthetic capabilities of sponge-associated chlamydiae.}, journal = {The ISME journal}, volume = {16}, number = {12}, pages = {2725-2740}, pmid = {36042324}, issn = {1751-7370}, mesh = {Animals ; Ecosystem ; Phylogeny ; *Chlamydia/genetics ; Bacteria ; Genomics ; *Porifera ; }, abstract = {Sponge microbiomes contribute to host health, nutrition, and defense through the production of secondary metabolites. Chlamydiae, a phylum of obligate intracellular bacteria ranging from animal pathogens to endosymbionts of microbial eukaryotes, are frequently found associated with sponges. However, sponge-associated chlamydial diversity has not yet been investigated at the genomic level and host interactions thus far remain unexplored. Here, we sequenced the microbiomes of three sponge species and found high, though variable, Chlamydiae relative abundances of up to 18.7% of bacteria. Using genome-resolved metagenomics 18 high-quality sponge-associated chlamydial genomes were reconstructed, covering four chlamydial families. Among these, Candidatus Sororchlamydiaceae shares a common ancestor with Chlamydiaceae animal pathogens, suggesting long-term co-evolution with animals. Based on gene content, sponge-associated chlamydiae resemble members from the same family more than sponge-associated chlamydiae of other families, and have greater metabolic versatility than known chlamydial animal pathogens. Sponge-associated chlamydiae are also enriched in genes for degrading diverse compounds found in sponges. Unexpectedly, we identified widespread genetic potential for secondary metabolite biosynthesis across Chlamydiae, which may represent an unexplored source of novel natural products. This finding suggests that Chlamydiae members may partake in defensive symbioses and that secondary metabolites play a wider role in mediating intracellular interactions. Furthermore, sponge-associated chlamydiae relatives were found in other marine invertebrates, pointing towards wider impacts of the Chlamydiae phylum on marine ecosystems.}, }
@article {pmid36042261, year = {2022}, author = {Madsen, CS and Makela, AV and Greeson, EM and Hardy, JW and Contag, CH}, title = {Engineered endosymbionts that alter mammalian cell surface marker, cytokine and chemokine expression.}, journal = {Communications biology}, volume = {5}, number = {1}, pages = {888}, pmid = {36042261}, issn = {2399-3642}, mesh = {Animals ; Chemokines ; *Cytokines/genetics ; *Listeria monocytogenes/genetics ; Mammals ; Phagosomes ; Transcription Factors ; }, abstract = {Developing modular tools that direct mammalian cell function and activity through controlled delivery of essential regulators would improve methods of guiding tissue regeneration, enhancing cellular-based therapeutics and modulating immune responses. To address this challenge, Bacillus subtilis was developed as a chassis organism for engineered endosymbionts (EES) that escape phagosome destruction, reside in the cytoplasm of mammalian cells, and secrete proteins that are transported to the nucleus to impact host cell response and function. Two synthetic operons encoding either the mammalian transcription factors Stat-1 and Klf6 or Klf4 and Gata-3 were recombined into the genome of B. subtilis expressing listeriolysin O (LLO) from Listeria monocytogenes and expressed from regulated promoters. Controlled expression of the mammalian proteins from B. subtilis LLO in the cytoplasm of J774A.1 macrophage/monocyte cells altered surface marker, cytokine and chemokine expression. Modulation of host cell fates displayed some expected patterns towards anti- or pro-inflammatory phenotypes by each of the distinct transcription factor pairs with further demonstration of complex regulation caused by a combination of the EES interaction and transcription factors. Expressing mammalian transcription factors from engineered intracellular B. subtilis as engineered endosymbionts comprises a new tool for directing host cell gene expression for therapeutic and research purposes.}, }
@article {pmid36039907, year = {2022}, author = {Wang, R and Sun, R and Zhang, Z and Vannini, C and Di Giuseppe, G and Liang, A}, title = {"Candidatus Euplotechlamydia quinta," a novel chlamydia-like bacterium hosted by the ciliate Euplotes octocarinatus (Ciliophora, Spirotrichea).}, journal = {The Journal of eukaryotic microbiology}, volume = {}, number = {}, pages = {e12945}, doi = {10.1111/jeu.12945}, pmid = {36039907}, issn = {1550-7408}, abstract = {Our knowledge of ciliate endosymbiont diversity greatly expanded over the past decades due to the development of characterization methods for uncultivable bacteria. Chlamydia-like bacteria have been described as symbionts of free-living amoebae and other phylogenetically diverse eukaryotic hosts. In the present work, a systematic survey of the bacterial diversity associated with the ciliate Euplotes octocarinatus strain Zam5b-1 was performed, using metagenomic screening as well as classical full-cycle rRNA approach, and a novel chlamydial symbiont was characterized. The metagenomic screening revealed 16S rRNA gene sequences from Polynucleobacter necessarius, three previously reported accessory symbionts, and a novel chlamydia-like bacterium. Following the full-cycle rRNA approach, we obtained the full-length 16S rRNA gene sequence of this chlamydia-like bacterium and developed probes for diagnostic fluorescence in situ hybridizations. The phylogenetic analysis of the 16S rRNA gene sequences unambiguously places the new bacterium in the family Rhabdochlamydiaceae. This is the first report of chlamydia-like bacterium being found in Euplotes. Based on the obtained data, the bacterium is proposed as a new candidate genus and species: "Candidatus Euplotechlamydia quinta."}, }
@article {pmid36034709, year = {2022}, author = {Jha, B and Reverte, M and Ronet, C and Prevel, F and Morgenthaler, FD and Desponds, C and Lye, LF and Owens, KL and Scarpellino, L and Dubey, LK and Sabine, A and Petrova, TV and Luther, SA and Beverley, SM and Fasel, N}, title = {In and out: Leishmania metastasis by hijacking lymphatic system and migrating immune cells.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {941860}, pmid = {36034709}, issn = {2235-2988}, support = {R01 AI130222/AI/NIAID NIH HHS/United States ; }, mesh = {Humans ; *Leishmania ; *Leishmania braziliensis ; *Leishmaniasis, Mucocutaneous ; Lymphatic System ; *Neoplasms ; }, abstract = {The lymphatic system plays a crucial role in mounting immune response against intracellular pathogens, and recent studies have documented its role in facilitating tumor dissemination linked largely with cancer cells. However, in mucocutaneous leishmaniasis (MCL) caused by Leishmania Viannia subgenus showing infectious metastasis and resulting in severe distant secondary lesions, the route of escape of these parasites to secondary sites has not yet been investigated in detail. Our results demonstrated that when infection was associated with inflammation and additionally exacerbated by the presence of dsRNA viral endosymbiont (LRV1), lymphatic vessels could serve as efficient routes for infected cells to egress from the primary site and colonize distant organs. We challenged this hypothesis by using the intracellular Leishmania protozoan parasites Leishmania guyanensis (Lgy) associated with or without a dsRNA viral endosymbiont, exacerbating the infection and responsible for a strong inflammatory response, and favoring metastasis of the infection. We analyzed possible cargo cells and the routes of dissemination through flow cytometry, histological analysis, and in vivo imaging in our metastatic model to show that parasites disseminated not only intracellularly but also as free extracellular parasites using migrating immune cells, lymph nodes (LNs), and lymph vessels, and followed intricate connections of draining and non-draining lymph node to finally end up in the blood and in distant skin, causing new lesions.}, }
@article {pmid36034693, year = {2022}, author = {Kopelyanskiy, D and Desponds, C and Prevel, F and Rossi, M and Migliorini, R and Snäkä, T and Eren, RO and Claudinot, S and Lye, LF and Pasparakis, M and Beverley, SM and Fasel, N}, title = {Leishmania guyanensis suppressed inducible nitric oxide synthase provoked by its viral endosymbiont.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {944819}, pmid = {36034693}, issn = {2235-2988}, support = {R01 AI029646/AI/NIAID NIH HHS/United States ; R01 AI130222/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cytokines ; Humans ; Interleukin-17 ; *Leishmania ; *Leishmania guyanensis/virology ; Leishmaniavirus ; Mice ; NF-kappa B ; Nitric Oxide ; *Nitric Oxide Synthase Type II/metabolism ; Toll-Like Receptor 3 ; }, abstract = {Inducible nitric oxide synthase (iNOS) is essential to the production of nitric oxide (NO), an efficient effector molecule against intracellular human pathogens such as Leishmania protozoan parasites. Some strains of Leishmania are known to bear a viral endosymbiont termed Leishmania RNA virus 1 (LRV1). Recognition of LRV1 by the innate immune sensor Toll-like receptor-3 (TLR3) leads to conditions worsening the disease severity in mice. This process is governed by type I interferon (type I IFNs) arising downstream of TLR3 stimulation and favoring the formation of secondary metastatic lesions. The formation of these lesions is mediated by the inflammatory cytokine IL-17A and occurs in the absence, or low level of, protective cytokine IFN-γ. Here, we described that the presence of LRV1 led to the initial expression of iNOS and low production of NO that failed to control infection. We subsequently showed that LRV1-triggered type I IFN was essential but insufficient to induce robust iNOS induction, which requires strong activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Leishmania guyanensis carrying LRV1 (LgyLRV1+) parasites mitigated strong iNOS production by limiting NF-kB activation via the induction of tumor necrosis factor-alpha-induced protein 3 (TNFAIP3), also known as A20. Moreover, our data suggested that production of LRV1-induced iNOS could be correlated with parasite dissemination and metastasis via elevated secretion of IL-17A in the draining lymph nodes. Our findings support an additional strategy by which LRV1-bearing Leishmania guyanensis evaded killing by nitric oxide and suggest that low levels of LRV1-induced NO might contribute to parasite metastasis.}, }
@article {pmid36015007, year = {2022}, author = {Špitalská, E and Minichová, L and Hamšíková, Z and Stanko, M and Kazimírová, M}, title = {Bartonella, Rickettsia, Babesia, and Hepatozoon Species in Fleas (Siphonaptera) Infesting Small Mammals of Slovakia (Central Europe).}, journal = {Pathogens (Basel, Switzerland)}, volume = {11}, number = {8}, pages = {}, pmid = {36015007}, issn = {2076-0817}, abstract = {Fleas (Siphonaptera) as obligate, blood-feeding ectoparasites are, together with ticks, hosted by small mammals and can transmit causative agents of serious infections. This study aimed to determine and characterize the presence and genetic diversity of Bartonella, Rickettsia, and apicomplexan parasites (Babesia, Hepatozoon) in fleas feeding on small mammals from three different habitat types (suburban, natural, and rural) in Slovakia. The most common pathogen in the examined fleas was Bartonella spp. (33.98%; 95% CI: 30.38-37.58), followed by Rickettsia spp. (19.1%; 95% CI: 16.25-22.24) and apicomplexan parasites (4.36%; 95% CI: 2.81-5.91). Bartonella strains belonging to B. taylorii, B. grahamii, B. elizabethae, Bartonella sp. wbs11, and B. rochalimae clades were identified in Ctenophthalmus agyrtes, C. congener, C. assimilis, C. sciurorum, C. solutus, C. bisoctodentatus, Palaeopsylla similis, Megabothris turbidus, and Nosopsyllus fasciatus within all habitats. The presence of Rickettsia helvetica, R. monacensis, and rickettsiae, belonging to the R. akari and R. felis clusters, and endosymbionts with a 96-100% identity with the Rickettsia endosymbiont of Nosopsyllus laeviceps laeviceps were also revealed in C. agyrtes, C. solutus, C. assimilis, C. congener, M. turbidus, and N. fasciatus. Babesia and Hepatozoon DNA was detected in the fleas from all habitat types. Hepatozoon sp. was detected in C. agyrtes, C. assimilis, and M. turbidus, while Babesia microti was identified from C. agyrtes, C. congener, and P. similis. The present study demonstrated the presence of zoonotic pathogens in fleas, parasitizing the wild-living small mammals of southwestern and central Slovakia and widens our knowledge of the ecology and genomic diversity of Bartonella, Rickettsia, Babesia, and Hepatozoon.}, }
@article {pmid36012723, year = {2022}, author = {Zong, Q and Mao, B and Zhang, HB and Wang, B and Yu, WJ and Wang, ZW and Wang, YF}, title = {Comparative Ubiquitome Analysis Reveals Deubiquitinating Effects Induced by Wolbachia Infection in Drosophila melanogaster.}, journal = {International journal of molecular sciences}, volume = {23}, number = {16}, pages = {}, pmid = {36012723}, issn = {1422-0067}, mesh = {Animals ; Cytoplasm/metabolism ; *Drosophila melanogaster/genetics ; Female ; Male ; Proteasome Endopeptidase Complex/metabolism ; Semen ; Testis/metabolism ; *Wolbachia ; }, abstract = {The endosymbiotic Wolbachia bacteria frequently cause cytoplasmic incompatibility (CI) in their insect hosts, where Wolbachia-infected males cross with uninfected females, leading to no or fewer progenies, indicating a paternal modification by Wolbachia. Recent studies have identified a Wolbachia protein, CidB, containing a DUB (deubiquitylating enzyme) domain, which can be loaded into host sperm nuclei and involved in CI, though the DUB activity is not necessary for CI in Drosophila melanogaster. To investigate whether and how Wolbachia affect protein ubiquitination in testes of male hosts and are thus involved in male fertility, we compared the protein and ubiquitinated protein expressions in D. melanogaster testes with and without Wolbachia. A total of 643 differentially expressed proteins (DEPs) and 309 differentially expressed ubiquitinated proteins (DEUPs) were identified to have at least a 1.5-fold change with a p-value of <0.05. Many DEPs were enriched in metabolic pathway, ribosome, RNA transport, and post-translational protein modification pathways. Many DEUPs were involved in metabolism, ribosome, and proteasome pathways. Notably, 98.1% DEUPs were downregulated in the presence of Wolbachia. Four genes coding for DEUPs in ubiquitin proteasome pathways were knocked down, respectively, in Wolbachia-free fly testes. Among them, Rpn6 and Rpn7 knockdown caused male sterility, with no mature sperm in seminal vesicles. These results reveal deubiquitylating effects induced by Wolbachia infection, suggesting that Wolbachia can widely deubiquitinate proteins that have crucial functions in male fertility of their hosts, but are not involved in CI. Our data provide new insights into the regulatory mechanisms of endosymbiont/host interactions and male fertility.}, }
@article {pmid36005392, year = {2022}, author = {Richter, I and Radosa, S and Cseresnyés, Z and Ferling, I and Büttner, H and Niehs, SP and Gerst, R and Scherlach, K and Figge, MT and Hillmann, F and Hertweck, C}, title = {Toxin-Producing Endosymbionts Shield Pathogenic Fungus against Micropredators.}, journal = {mBio}, volume = {13}, number = {5}, pages = {e0144022}, pmid = {36005392}, issn = {2150-7511}, support = {P40 OD010440/OD/NIH HHS/United States ; }, mesh = {Animals ; *Burkholderia/metabolism ; *Antimitotic Agents/metabolism ; Macrolides ; Symbiosis ; *Oryza/microbiology ; *Toxins, Biological ; Seedlings ; Soil ; }, abstract = {The fungus Rhizopus microsporus harbors a bacterial endosymbiont (Mycetohabitans rhizoxinica) for the production of the antimitotic toxin rhizoxin. Although rhizoxin is the causative agent of rice seedling blight, the toxinogenic bacterial-fungal alliance is, not restricted to the plant disease. It has been detected in numerous environmental isolates from geographically distinct sites covering all five continents, thus raising questions regarding the ecological role of rhizoxin beyond rice seedling blight. Here, we show that rhizoxin serves the fungal host in fending off protozoan and metazoan predators. Fluorescence microscopy and coculture experiments with the fungivorous amoeba Protostelium aurantium revealed that ingestion of R. microsporus spores is toxic to P. aurantium. This amoebicidal effect is caused by the dominant bacterial rhizoxin congener rhizoxin S2, which is also lethal toward the model nematode Caenorhabditis elegans. By combining stereomicroscopy, automated image analysis, and quantification of nematode movement, we show that the fungivorous nematode Aphelenchus avenae actively feeds on R. microsporus that is lacking endosymbionts, whereas worms coincubated with symbiotic R. microsporus are significantly less lively. This study uncovers an unexpected ecological role of rhizoxin as shield against micropredators. This finding suggests that predators may function as an evolutionary driving force to maintain toxin-producing endosymbionts in nonpathogenic fungi. IMPORTANCE The soil community is a complex system characterized by predator-prey interactions. Fungi have developed effective strategies to defend themselves against predators. Understanding these strategies is of critical importance for ecology, medicine, and biotechnology. In this study, we shed light on the defense mechanisms of the phytopathogenic Rhizopus-Mycetohabitans symbiosis that has spread worldwide. We report an unexpected role of rhizoxin, a secondary metabolite produced by the bacterium M. rhizoxinica residing within the hyphae of R. microsporus. We show that this bacterial secondary metabolite is utilized by the fungal host to successfully fend off fungivorous protozoan and metazoan predators and thus identified a fundamentally new function of this infamous cytotoxic compound. This endosymbiont-dependent predator defense illustrates an unusual strategy employed by fungi that has broader implications, since it may serve as a model for understanding how animal predation acts as an evolutionary driving force to maintain endosymbionts in nonpathogenic fungi.}, }
@article {pmid36003934, year = {2022}, author = {Nishide, Y and Oguchi, K and Murakami, M and Moriyama, M and Koga, R and Fukatsu, T}, title = {Endosymbiotic bacteria of the boar louse Haematopinus apri (Insecta: Phthiraptera: Anoplura).}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {962252}, pmid = {36003934}, issn = {1664-302X}, abstract = {Insects exclusively feeding on vertebrate blood are usually dependent on symbiotic bacteria for provisioning of B vitamins. Among them, sucking lice are prominent in that their symbiotic bacteria as well as their symbiotic organs exhibit striking diversity. Here we investigated the bacterial diversity associated with the boar louse Haematopinus apri in comparison with the hog louse Haematopinus suis. Amplicon sequencing analysis identified the primary endosymbiont predominantly detected from all populations of H. apri with some minor secondary bacterial associates. Sequencing and phylogenetic analysis of bacterial 16S rRNA gene confirmed that the endosymbionts of the boar louse H. apri, the hog louse H. suis and the cattle louse Haematopinus eurysternus form a distinct clade in the Gammaproteobacteria. The endosymbiont clade of Haematopinus spp. was phylogenetically distinct from the primary endosymbionts of other louse lineages. Fluorescence in situ hybridization visualized the endosymbiont localization within midgut epithelium, ovarial ampulla and posterior oocyte of H. apri, which were substantially the same as the endosymbiont localization previously described in H. suis and H. eurysternus. Mitochondrial haplotype analysis revealed that, although the domestic pig was derived from the wild boar over the past 8,000 years of human history, the populations of H. apri constituted a distinct sister clade to the populations of H. suis. Based on these results, we discussed possible evolutionary trajectories of the boar louse, the hog louse and their endosymbionts in the context of swine domestication. We proposed 'Candidatus Haematopinicola symbiotica' for the distinct clade of the endosymbionts of Haematopinus spp.}, }
@article {pmid36003268, year = {2022}, author = {Davies, OK and Dorey, JB and Stevens, MI and Gardner, MG and Bradford, TM and Schwarz, MP}, title = {Unparalleled mitochondrial heteroplasmy and Wolbachia co-infection in the non-model bee, Amphylaeus morosus.}, journal = {Current research in insect science}, volume = {2}, number = {}, pages = {100036}, pmid = {36003268}, issn = {2666-5158}, abstract = {Mitochondrial heteroplasmy is the occurrence of more than one type of mitochondrial DNA within a single individual. Although generally reported to occur in a small subset of individuals within a species, there are some instances of widespread heteroplasmy across entire populations. Amphylaeus morosus is an Australian native bee species in the diverse and cosmopolitan bee family Colletidae. This species has an extensive geographical range along the eastern Australian coast, from southern Queensland to western Victoria, covering approximately 2,000 km. Seventy individuals were collected from five localities across this geographical range and sequenced using Sanger sequencing for the mitochondrial cytochrome c oxidase subunit I (COI) gene. These data indicate that every individual had the same consistent heteroplasmic sites but no other nucleotide variation, suggesting two conserved and widespread heteroplasmic mitogenomes. Ion Torrent shotgun sequencing revealed that heteroplasmy occurred across multiple mitochondrial protein-coding genes and is unlikely explained by transposition of mitochondrial genes into the nuclear genome (NUMTs). DNA sequence data also demonstrated a consistent co-infection of Wolbachia across the A. morosus distribution with every individual infected with both bacterial strains. Our data are consistent with the presence of two mitogenomes within all individuals examined in this species and suggest a major divergence from standard patterns of mitochondrial inheritance. Because the host's mitogenome and the Wolbachia genome are genetically linked through maternal inheritance, we propose three possible hypotheses that could explain maintenance of the widespread and conserved co-occurring bacterial and mitochondrial genomes in this species.}, }
@article {pmid36000911, year = {2022}, author = {Qi, Y and Ai, L and Zhu, C and Ye, F and Lv, R and Wang, J and Mao, Y and Lu, N and Tan, W}, title = {Wild Hedgehogs and Their Parasitic Ticks Coinfected with Multiple Tick-Borne Pathogens in Jiangsu Province, Eastern China.}, journal = {Microbiology spectrum}, volume = {10}, number = {5}, pages = {e0213822}, pmid = {36000911}, issn = {2165-0497}, mesh = {Animals ; Humans ; *Ticks/microbiology/parasitology ; Hedgehogs/parasitology ; *Coinfection/epidemiology/veterinary ; *Rickettsia/genetics ; *Tick-Borne Diseases/epidemiology/veterinary/microbiology ; Ehrlichia/genetics ; *Parasites ; }, abstract = {The increasing awareness of emerging tickborne pathogens (TBPs) has inspired much research. In the present study, the coinfections of TBPs both in ticks and their wild hedgehog hosts in Jiangsu province, Eastern China were determined by metagenome next-generation sequencing and nested PCR. As a result, Rickettsia japonica (81.1%), novel Rickettsia sp. SFGR-1 (5.1%), Anaplasma bovis (12%), A. platys (6.3%), novel Ehrlichia spp. Ehr-1 (16%) and Ehr-2 (0.6%), E. ewingii-like strain (0.6%), Coxiella burnetii (10.9%), and a novel Coxiella-like endosymbiont (CLE) strain (61.1%) were detected in Haemaphysalis flava ticks. A. bovis (43.8%), Ehrlichia sp. Ehr-1 (83.3%), and C. burnetii (80%) were detected in Erinaceus amurensis hedgehogs. Coinfection rates with various TBPs were 71.5% and 83.3% in ticks and hedgehogs, respectively, both with double-pathogen/endosymbiont coinfection rates over 50%. We found the following. (i) Er. amurensis hedgehogs seem to contribute to the natural cycles of R. japonica, A. bovis, Ehrlichia sp., and C. burnetii and may be reservoirs of them except for R. japonica, and A. bovis is proved to infect hedgehogs for the first time. (ii) H. flava is proved to harbor various TBPs as a reservoir host, including CLE identified for the first time, which could inhibit coinfection of C. burnetii while promoting that of Rickettsia spp. in H. flava. (iii) Four novel TBP species were identified. This study provides useful epidemiological information crucial for assessing the potential infection risks to humans, thus benefiting the development of strategies to prevent and control tick-borne diseases. IMPORTANCE In the present study, we found the following. (i) Er. amurensis hedgehogs seem to contribute to the natural cycles of R. japonica, A. bovis, Ehrlichia sp., and C. burnetii and may be reservoirs of them except for R. japonica, and A. bovis is proved to infect hedgehogs for the first time. (ii) H. flava is proved to harbor various tickborne pathogens (TBPs) as a reservoir host, including Coxiella-like endosymbiont (CLE) identified for the first time, which could inhibit coinfection of C. burnetii while promoting that of Rickettsia spp. in H. flava. (iii) Four novel TBP species were identified. This study provides useful epidemiological information on TBPs harbored and transmitted by ticks and their hosts, for assessing the potential infection risks to humans, thus benefiting the developing strategies for tick-borne diseases prevention and control.}, }
@article {pmid35997584, year = {2022}, author = {Breusing, C and Klobusnik, NH and Hauer, MA and Beinart, RA}, title = {Genome assembly of the chemosynthetic endosymbiont of the hydrothermal vent snail Alviniconcha adamantis from the Mariana Arc.}, journal = {G3 (Bethesda, Md.)}, volume = {12}, number = {10}, pages = {}, pmid = {35997584}, issn = {2160-1836}, mesh = {Ammonia ; Animals ; Bacteria/genetics ; Ecosystem ; *Gammaproteobacteria/genetics ; *Hydrothermal Vents/microbiology ; Phylogeny ; Snails ; Symbiosis/genetics ; Urea ; Waste Products ; }, abstract = {Chemosynthetic animal-microbe symbioses sustain hydrothermal vent communities in the global deep sea. In the Indo-Pacific Ocean, hydrothermal ecosystems are often dominated by gastropod species of the genus Alviniconcha, which live in association with chemosynthetic Gammaproteobacteria or Campylobacteria. While the symbiont genomes of most extant Alviniconcha species have been sequenced, no genome information is currently available for the gammaproteobacterial endosymbiont of Alviniconcha adamantis-a comparatively shallow living species that is thought to be the ancestor to all other present Alviniconcha lineages. Here, we report the first genome sequence for the symbiont of A. adamantis from the Chamorro Seamount at the Mariana Arc. Our phylogenomic analyses show that the A. adamantis symbiont is most closely related to Chromatiaceae endosymbionts of the hydrothermal vent snails Alviniconcha strummeri and Chrysomallon squamiferum, but represents a distinct bacterial species or possibly genus. Overall, the functional capacity of the A. adamantis symbiont appeared to be similar to other chemosynthetic Gammaproteobacteria, though several flagella and chemotaxis genes were detected, which are absent in other gammaproteobacterial Alviniconcha symbionts. These differences might suggest potential contrasts in symbiont transmission dynamics, host recognition, or nutrient transfer. Furthermore, an abundance of genes for ammonia transport and urea usage could indicate adaptations to the oligotrophic waters of the Mariana region, possibly via recycling of host- and environment-derived nitrogenous waste products. This genome assembly adds to the growing genomic resources for chemosynthetic bacteria from hydrothermal vents and will be valuable for future comparative genomic analyses assessing gene content evolution in relation to environment and symbiotic lifestyles.}, }
@article {pmid35997363, year = {2022}, author = {Sgroi, G and Iatta, R and Lovreglio, P and Stufano, A and Laidoudi, Y and Mendoza-Roldan, JA and Bezerra-Santos, MA and Veneziano, V and Di Gennaro, F and Saracino, A and Chironna, M and Bandi, C and Otranto, D}, title = {Detection of Endosymbiont Candidatus Midichloria mitochondrii and Tickborne Pathogens in Humans Exposed to Tick Bites, Italy.}, journal = {Emerging infectious diseases}, volume = {28}, number = {9}, pages = {1824-1832}, pmid = {35997363}, issn = {1080-6059}, mesh = {Animals ; Humans ; *Ixodes/microbiology ; Phylogeny ; *Rickettsia/genetics ; Rickettsiales ; *Tick Bites/epidemiology ; }, abstract = {During 2021, we collected blood and serum samples from 135 persons exposed to tick bites in southern Italy. We serologically and molecularly screened for zoonotic tickborne pathogens and only molecularly screened for Candidatus Midichloria mitochondrii. Overall, 62 (45.9%) persons tested positive for tickborne pathogens. Coxiella burnetii was detected most frequently (27.4%), along with Rickettsia spp. (21.5%) and Borrelia spp. (10.4%). We detected Candidatus M. mitochondrii DNA in 46 (34.1%) participants who had statistically significant associations to tickborne pathogens (p<0.0001). Phylogenetic analysis of Candidatus M. mitochondrii sequences revealed 5 clades and 8 human sequence types that correlated with vertebrates, Ixodes spp. ticks, and countries in Europe. These data demonstrated a high circulation of tickborne pathogens and Candidatus M. mitochondrii DNA in persons participating in outdoor activities in southern Italy. Our study shows how coordinated surveillance among patients, clinicians, and veterinarians could inform a One Health approach for monitoring and controlling the circulation of tickborne pathogens.}, }
@article {pmid35994143, year = {2022}, author = {Hirunkanokpun, S and Ahantarig, A and Baimai, V and Pramual, P and Rakthong, P and Trinachartvanit, W}, title = {Correction to: Spotted fever group Rickettsia, Anaplasma and Coxiella‑like endosymbiont in Haemaphysalis ticks from mammals in Thailand.}, journal = {Veterinary research communications}, volume = {}, number = {}, pages = {}, doi = {10.1007/s11259-022-09988-3}, pmid = {35994143}, issn = {1573-7446}, }
@article {pmid35992676, year = {2022}, author = {Sadanandane, C and Gunasekaran, K and Panneer, D and Subbarao, SK and Rahi, M and Vijayakumar, B and Athithan, V and Sakthivel, A and Dinesh, S and Jambulingam, P}, title = {Studies on the fitness characteristics of wMel- and wAlbB-introgressed Aedes aegypti (Pud) lines in comparison with wMel- and wAlbB-transinfected Aedes aegypti (Aus) and wild-type Aedes aegypti (Pud) lines.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {947857}, pmid = {35992676}, issn = {1664-302X}, abstract = {Wolbachia, an intracellular maternally transmitted endosymbiont, has been shown to interfere with the replication of dengue virus in Aedes aegypti mosquitoes. The Wolbachia-transinfected Ae. aegypti has been currently released in many countries to test its effectiveness in preventing the transmission of dengue virus. ICMR-Vector Control Research Centre in collaboration with World Mosquito Program Monash University, Australia, has generated two new Wolbachia-introgressed Ae. aegypti Puducherry (Pud) lines via backcrossing Ae. aegypti females of Australian (Aus) strains, infected with wMel and wAlbB Wolbachia with wild-type Ae. aegypti Puducherry (Pud) males. Wolbachia infections are known to induce a fitness cost and confer benefit on the host mosquito populations that will influence spread of the Wolbachia into native wild mosquito populations during the field release. Hence, the induced fitness cost or benefit/advantage in the two newly generated Ae. aegypti (Pud) lines was assessed in the laboratory in comparison with the wild-type Ae. aegypti (Pud) strain. In addition, maternal transmission (MT) efficiency, induced cytoplasmic incompatibility (CI), and insecticide resistance status of the two (Pud) lines were determined to assess the likely frequency of wMel and wAlbB infections in the native wild population after field invasion. The study shows that wMel and wAlbB infections did not induce any fitness cost on the two newly generated (Pud) lines. Rather, in terms of wing length, fecundity, egg hatch rate, and adult survival, the Wolbachia introgression conferred fitness benefits on the (Pud) lines compared to uninfected Wolbachia free wild Ae. aegypti population. wMel and wAlbB exhibited a high maternal transmission (99-100%) and induced nearly complete (98-100%) cytoplasmic incompatibility. Both the (Pud) lines were resistant to deltamethrin, malathion, DDT, and temephos, and the level of resistance was almost the same between the two lines as in the wild type. Overall, the stable association of wMel and wAlbB established with Ae. aegypti and the reproductive advantages of the (Pud) lines encourage a pilot release in the field for population replacement potential.}, }
@article {pmid35992159, year = {2022}, author = {Bekkar, A and Isorce, N and Snäkä, T and Claudinot, S and Desponds, C and Kopelyanskiy, D and Prével, F and Reverte, M and Xenarios, I and Fasel, N and Teixeira, F}, title = {Dissection of the macrophage response towards infection by the Leishmania-viral endosymbiont duo and dynamics of the type I interferon response.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {941888}, pmid = {35992159}, issn = {2235-2988}, mesh = {Animals ; Humans ; *Interferon Type I/immunology ; *Leishmania/virology ; *Leishmaniasis/immunology/parasitology/virology ; *Leishmaniavirus ; *Macrophages/immunology/parasitology ; Mice ; }, abstract = {Leishmania RNA virus 1 (LRV1) is a double-stranded RNA virus found in some strains of the human protozoan parasite Leishmania, the causative agent of leishmaniasis, a neglected tropical disease. Interestingly, the presence of LRV1 inside Leishmania constitutes an important virulence factor that worsens the leishmaniasis outcome in a type I interferon (IFN)-dependent manner and contributes to treatment failure. Understanding how macrophages respond toward Leishmania alone or in combination with LRV1 as well as the role that type I IFNs may play during infection is fundamental to oversee new therapeutic strategies. To dissect the macrophage response toward infection, RNA sequencing was performed on murine wild-type and Ifnar-deficient bone marrow-derived macrophages infected with Leishmania guyanensis (Lgy) devoid or not of LRV1. Additionally, macrophages were treated with poly I:C (mimetic virus) or with type I IFNs. By implementing a weighted gene correlation network analysis, the groups of genes (modules) with similar expression patterns, for example, functionally related, coregulated, or the members of the same functional pathway, were identified. These modules followed patterns dependent on Leishmania, LRV1, or Leishmania exacerbated by the presence of LRV1. Not only the visualization of how individual genes were embedded to form modules but also how different modules were related to each other were observed. Thus, in the context of the observed hyperinflammatory phenotype associated to the presence of LRV1, it was noted that the biomarkers tumor-necrosis factor α (TNF-α) and the interleukin 6 (IL-6) belonged to different modules and that their regulating specific Src-family kinases were segregated oppositely. In addition, this network approach revealed the strong and sustained effect of LRV1 on the macrophage response and genes that had an early, late, or sustained impact during infection, uncovering the dynamics of the IFN response. Overall, this study contributed to shed light and dissect the intricate macrophage response toward infection by the Leishmania-LRV1 duo and revealed the crosstalk between modules made of coregulated genes and provided a new resource that can be further explored to study the impact of Leishmania on the macrophage response.}, }
@article {pmid35987324, year = {2022}, author = {Fujii, S and Somei, K and Asaeda, Y and Igawa, T and Hattori, K and Yoshida, T and Sambongi, Y}, title = {Heterologous expression and biochemical comparison of two homologous SoxX proteins of endosymbiotic Candidatus Vesicomyosocius okutanii and free-living Hydrogenovibrio crunogenus from deep-sea environments.}, journal = {Protein expression and purification}, volume = {200}, number = {}, pages = {106157}, doi = {10.1016/j.pep.2022.106157}, pmid = {35987324}, issn = {1096-0279}, mesh = {Animals ; Bacteria/genetics ; *Bivalvia/genetics/metabolism ; Cytochromes c ; *Gammaproteobacteria ; Phylogeny ; Piscirickettsiaceae ; Sulfur/metabolism ; Sulfur Compounds ; }, abstract = {Candidatus Vesicomyosocius okutanii is a currently uncultured endosymbiotic bacterium of Phreagena okutanii, a clam that inhabits deep-sea vent environments. The genome of Ca. V. okutanii encodes a sulfur-oxidizing (Sox) enzyme complex, presumably generating biological energy for the host from inorganic sulfur compounds. Here, Ca. V. okutanii SoxX (VoSoxX), a mono-heme cytochrome c component of the Sox complex, was shown to be phylogenetically related to its homologous counterpart (HcSoxX) from a free-living deep-sea bacterium, Hydrogenovibrio crunogenus. Both proteins were heterologously expressed in Escherichia coli co-expressing cytochrome c maturation genes for comparative biochemical analysis. The VoSoxX recombinant had significantly lower thermal stability than HcSoxX, reflecting the difference in growth conditions of the source bacteria. The endosymbiont inhabits a mild intracellular environment, whereas the free-living bacterium dwells in a harsh environment. This study represents the first successful case of heterologous expression of genes from Ca. V. okutanii, allowing further biochemical studies of the molecular mechanism of sulfur oxidation in deep-sea environments.}, }
@article {pmid35979496, year = {2022}, author = {Říhová, J and Bell, KC and Nováková, E and Hypša, V}, title = {Lightella neohaematopini: A new lineage of highly reduced endosymbionts coevolving with chipmunk lice of the genus Neohaematopinus.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {900312}, pmid = {35979496}, issn = {1664-302X}, abstract = {Sucking lice (Anoplura) are known to have established symbiotic associations multiple times with different groups of bacteria as diverse as Enterobacteriales, Legionellales, and Neisseriales. This diversity, together with absence of a common coevolving symbiont (such as Buchnera, in aphids), indicates that sucking lice underwent a series of symbiont acquisitions, losses, and replacements. To better understand evolution and significance of louse symbionts, genomic and phylogenetic data are needed from a broader taxonomic diversity of lice and their symbiotic bacteria. In this study, we extend the known spectrum of the louse symbionts with a new lineage associated with Neohaematopinus pacificus, a louse species that commonly parasitizes North American chipmunks. The recent coevolutionary analysis showed that rather than a single species, these lice form a cluster of unique phylogenetic lineages specific to separate chipmunk species (or group of closely related species). Using metagenomic assemblies, we show that the lice harbor a bacterium which mirrors their phylogeny and displays traits typical for obligate mutualists. Phylogenetic analyses place this bacterium within Enterobacteriaceae on a long branch related to another louse symbiont, "Candidatus Puchtella pedicinophila." We propose for this symbiotic lineage the name "Candidatus Lightella neohaematopini." Based on the reconstruction of metabolic pathways, we suggest that like other louse symbionts, L. neohaematopini provides its host with at least some B vitamins. In addition, several samples harbored another symbiotic bacterium phylogenetically affiliated with the Neisseriales-related symbionts described previously from the lice Polyplax serrata and Hoplopleura acanthopus. Characterizing these bacteria further extend the known diversity of the symbiotic associations in lice and show unique complexity and dynamics of the system.}, }
@article {pmid35976120, year = {2022}, author = {Shastry, V and Bell, KL and Buerkle, CA and Fordyce, JA and Forister, ML and Gompert, Z and Lebeis, SL and Lucas, LK and Marion, ZH and Nice, CC}, title = {A continental-scale survey of Wolbachia infections in blue butterflies reveals evidence of interspecific transfer and invasion dynamics.}, journal = {G3 (Bethesda, Md.)}, volume = {12}, number = {10}, pages = {}, pmid = {35976120}, issn = {2160-1836}, mesh = {Animals ; *Butterflies/genetics/microbiology ; DNA, Mitochondrial/genetics ; Haplotypes/genetics ; Phylogeny ; *Wolbachia/genetics ; }, abstract = {Infections by maternally inherited bacterial endosymbionts, especially Wolbachia, are common in insects and other invertebrates but infection dynamics across species ranges are largely under studied. Specifically, we lack a broad understanding of the origin of Wolbachia infections in novel hosts, and the historical and geographical dynamics of infections that are critical for identifying the factors governing their spread. We used Genotype-by-Sequencing data from previous population genomics studies for range-wide surveys of Wolbachia presence and genetic diversity in North American butterflies of the genus Lycaeides. As few as one sequence read identified by assembly to a Wolbachia reference genome provided high accuracy in detecting infections in host butterflies as determined by confirmatory PCR tests, and maximum accuracy was achieved with a threshold of only 5 sequence reads per host individual. Using this threshold, we detected Wolbachia in all but 2 of the 107 sampling localities spanning the continent, with infection frequencies within populations ranging from 0% to 100% of individuals, but with most localities having high infection frequencies (mean = 91% infection rate). Three major lineages of Wolbachia were identified as separate strains that appear to represent 3 separate invasions of Lycaeides butterflies by Wolbachia. Overall, we found extensive evidence for acquisition of Wolbachia through interspecific transfer between host lineages. Strain wLycC was confined to a single butterfly taxon, hybrid lineages derived from it, and closely adjacent populations in other taxa. While the other 2 strains were detected throughout the rest of the continent, strain wLycB almost always co-occurred with wLycA. Our demographic modeling suggests wLycB is a recent invasion. Within strain wLycA, the 2 most frequent haplotypes are confined almost exclusively to separate butterfly taxa with haplotype A1 observed largely in Lycaeides melissa and haplotype A2 observed most often in Lycaeides idas localities, consistent with either cladogenic mode of infection acquisition from a common ancestor or by hybridization and accompanying mutation. More than 1 major Wolbachia strain was observed in 15 localities. These results demonstrate the utility of using resequencing data from hosts to quantify Wolbachia genetic variation and infection frequency and provide evidence of multiple colonizations of novel hosts through hybridization between butterfly lineages and complex dynamics between Wolbachia strains.}, }
@article {pmid35973490, year = {2022}, author = {Qi, S and Al Naggar, Y and Li, J and Liu, Z and Xue, X and Wu, L and El-Seedi, HR and Wang, K}, title = {Acaricide flumethrin-induced sublethal risks in honeybees are associated with gut symbiotic bacterium Gilliamella apicola through microbe-host metabolic interactions.}, journal = {Chemosphere}, volume = {307}, number = {Pt 3}, pages = {136030}, doi = {10.1016/j.chemosphere.2022.136030}, pmid = {35973490}, issn = {1879-1298}, mesh = {*Acaricides/toxicity ; Animals ; Anti-Bacterial Agents ; Bacteria ; Bees ; Gammaproteobacteria ; Glycerophospholipids ; *Pesticides ; Pyrethrins ; }, abstract = {Flumethrin is one of the few acaricides that permit the control of Varroa disease or varroosis in bee colonies. However, flumethrin accumulates in hive products. We previously discovered that sublethal doses of flumethrin induce significant physiological stress in honeybees (Apis mellifera L.), however its potential impacts on the honeybee gut microenvironment remains unknown. To fill this gap, honeybees were exposed to a field-relevant concentration of flumethrin (10 μg/L) for 14 d and its potential impacts on gut system were evaluated. The results indicated that flumethrin triggered immune responses in the gut but had limited effects on survival and gut microbial composition. However, survival stress drastically increased in bees exposed to antibiotics, suggesting that the gut microbiota is closely related to flumethrin-induced dysbiosis in the bee gut. Based on a non-targeted metabolomics approach, flumethrin at 10 μg/L considerably altered the composition of intestinal metabolites, and we discovered that this metabolic stress was closely linked with a reduction of gut core bacterial endosymbiont Gilliamella spp. through a combination of microbiological and metabolomics investigations. Finally, an in vitro study showed that while flumethrin does not directly inhibit the growth of Gilliamella apicola isolates, it does have a significant impact on the glycerophospholipid metabolism in bacteria cells, which was also observed in host bees. These findings indicated that even though flumethrin administered at environmental relevant concentrations does not significantly induce death in honeybees, it still alters the metabolism balance between honeybees and the gut symbiotic bacterium, G. apicola. The considerable negative impact of flumethrin on the honeybee gut microenvironment emphasizes the importance of properly monitoring acaricide to avoid potential environmental concerns, and further studies are needed to illustrate the mode of action of bee health-gut microbiota-exogenous pesticides.}, }
@article {pmid35972515, year = {2022}, author = {Oliveira, CYB and Abreu, JL and Santos, EP and Matos, &#xc2;P and Tribuzi, G and Oliveira, CDL and Veras, BO and Bezerra, RS and Müller, MN and Gálvez, AO}, title = {Light induces peridinin and docosahexaenoic acid accumulation in the dinoflagellate Durusdinium glynnii.}, journal = {Applied microbiology and biotechnology}, volume = {106}, number = {18}, pages = {6263-6276}, pmid = {35972515}, issn = {1432-0614}, mesh = {Antioxidants ; Carotenoids ; Chlorophyll ; *Dinoflagellida ; Docosahexaenoic Acids ; }, abstract = {Peridinin is a light-harvesting carotenoid present in phototrophic dinoflagellates and has great potential for new drug applications and cosmetics development. Herein, the effects of irradiance mediated by light-emitting diodes on growth performance, carotenoid and fatty acid profiles, and antioxidant activity of the endosymbiotic dinoflagellate Durusdinium glynnii were investigated. The results demonstrate that D. glynnii is particularly well adapted to low-light conditions; however, it can be high-light-tolerant. In contrast to other light-harvesting carotenoids, the peridinin accumulation in D. glynnii occurred during high-light exposure. The peridinin to chlorophyll-a ratio varied as a function of irradiance, while the peridinin to total carotenoids ratio remained stable. Under optimal irradiance for growth, there was a peak in docosahexaenoic acid (DHA) bioaccumulation. This study contributes to the understanding of the photoprotective role of peridinin in endosymbiont dinoflagellates and highlights the antioxidant activity of peridinin-rich extracts. KEY POINTS: • Peridinin has a protective role against chlorophyll photo-oxidation • High light conditions induce cellular peridinin accumulation • D. glynnii accumulates high amounts of DHA under optimal light supply.}, }
@article {pmid35968950, year = {2022}, author = {Aquino, MF and Simoes-Barbosa, A}, title = {A Microbial Piñata: Bacterial Endosymbionts of Trichomonas vaginalis Come in Different Flavors.}, journal = {mBio}, volume = {13}, number = {4}, pages = {e0132322}, pmid = {35968950}, issn = {2150-7511}, mesh = {Bacteria/genetics ; Female ; Humans ; *Mycoplasma ; Mycoplasma hominis/genetics ; *Trichomonas vaginalis/genetics ; Vagina/microbiology ; }, abstract = {The protozoan parasite Trichomonas vaginalis causes trichomoniasis, a prevalent human urogenital infection with significant morbidity that is commonly associated with vaginal dysbiosis. Exacerbation of T. vaginalis pathogenicity has been related to endosymbionts, including mycoplasma, and thought for a while to be solely attributable to Mycoplasma hominis. In a recent publication, Margarita and colleagues (https://journals.asm.org/doi/10.1128/mbio.00918-22) showed that endosymbiosis extends to a second species of mycoplasma known as "Candidatus Mycoplasma girerdii." Those authors confirmed the strong association of T. vaginalis with both species of mycoplasma by reassessing clinical samples. Additionally, they showed that in vitro symbiosis of protozoa and bacteria resulted in the modulation of gene expression of T. vaginalis and enhancement of parasite cytoadhesion and hemolytic activity in culture assays. In this commentary, we portray T. vaginalis as a synergistically interacting multimicrobe organism-a "microbial piñata"-whose endosymbionts contribute significantly to the pathophysiology of this medically important protozoan parasite.}, }
@article {pmid35967981, year = {2022}, author = {Shropshire, JD and Hamant, E and Conner, WR and Cooper, BS}, title = {cifB-transcript levels largely explain cytoplasmic incompatibility variation across divergent Wolbachia.}, journal = {PNAS nexus}, volume = {1}, number = {3}, pages = {pgac099}, pmid = {35967981}, issn = {2752-6542}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, abstract = {Divergent hosts often associate with intracellular microbes that influence their fitness. Maternally transmitted Wolbachia bacteria are the most common of these endosymbionts, due largely to cytoplasmic incompatibility (CI) that kills uninfected embryos fertilized by Wolbachia-infected males. Closely related infections in females rescue CI, providing a relative fitness advantage that drives Wolbachia to high frequencies. One prophage-associated gene (cifA) governs rescue, and two contribute to CI (cifA and cifB), but CI strength ranges from very strong to very weak for unknown reasons. Here, we investigate CI-strength variation and its mechanistic underpinnings in a phylogenetic context across 20 million years (MY) of Wolbachia evolution in Drosophila hosts diverged up to 50 MY. These Wolbachia encode diverse Cif proteins (100% to 7.4% pairwise similarity), and AlphaFold structural analyses suggest that CifB sequence similarities do not predict structural similarities. We demonstrate that cifB-transcript levels in testes explain CI strength across all but two focal systems. Despite phylogenetic discordance among cifs and the bulk of the Wolbachia genome, closely related Wolbachia tend to cause similar CI strengths and transcribe cifB at similar levels. This indicates that other non-cif regions of the Wolbachia genome modulate cif-transcript levels. CI strength also increases with the length of the host's larval life stage, presumably due to prolonged cif action. Our findings reveal that cifB-transcript levels largely explain CI strength, while highlighting other covariates. Elucidating CI's mechanism contributes to our understanding of Wolbachia spread in natural systems and to improving the efficacy of CI-based biocontrol of arboviruses and agricultural pests globally.}, }
@article {pmid35963240, year = {2022}, author = {Su, Y and Lin, HC and Teh, LS and Chevance, F and James, I and Mayfield, C and Golic, KG and Gagnon, JA and Rog, O and Dale, C}, title = {Rational engineering of a synthetic insect-bacterial mutualism.}, journal = {Current biology : CB}, volume = {32}, number = {18}, pages = {3925-3938.e6}, doi = {10.1016/j.cub.2022.07.036}, pmid = {35963240}, issn = {1879-0445}, support = {R35 GM136389/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids, Aromatic ; Animals ; Bacteria/genetics ; Insecta/microbiology ; Phenylalanine ; Phylogeny ; *Symbiosis ; Tyrosine ; *Weevils/genetics ; }, abstract = {Many insects maintain mutualistic associations with bacterial endosymbionts, but little is known about how they originate in nature. In this study, we describe the establishment and manipulation of a synthetic insect-bacterial symbiosis in a weevil host. Following egg injection, the nascent symbiont colonized many tissues, including prototypical somatic and germinal bacteriomes, yielding maternal transmission over many generations. We then engineered the nascent symbiont to overproduce the aromatic amino acids tyrosine and phenylalanine, which facilitate weevil cuticle strengthening and accelerated larval development, replicating the function of mutualistic symbionts that are widely distributed among weevils and other beetles in nature. Our work provides empirical support for the notion that mutualistic symbioses can be initiated in insects by the acquisition of environmental bacteria. It also shows that certain bacterial genera, including the Sodalis spp. used in our study, are predisposed to develop these associations due to their ability to maintain benign infections and undergo vertical transmission in diverse insect hosts, facilitating the partner-fidelity feedback that is critical for the evolution of obligate mutualism. These experimental advances provide a new platform for laboratory studies focusing on the molecular mechanisms and evolutionary processes underlying insect-bacterial symbiosis.}, }
@article {pmid35955579, year = {2022}, author = {Zuber, L and Domínguez-Santos, R and García-Ferris, C and Silva, FJ}, title = {Identification of the Gene Repertoire of the IMD Pathway and Expression of Antimicrobial Peptide Genes in Several Tissues and Hemolymph of the Cockroach Blattella germanica.}, journal = {International journal of molecular sciences}, volume = {23}, number = {15}, pages = {}, pmid = {35955579}, issn = {1422-0067}, mesh = {Adenosine Monophosphate ; Animals ; Antimicrobial Peptides ; *Blattellidae/genetics ; Female ; *Flavobacteriaceae ; Hemolymph ; }, abstract = {Antimicrobial peptide (AMP) genes, triggered by Toll and IMD pathways, are essential components of the innate immune system in the German cockroach Blattella germanica. Besides their role in killing pathogenic bacteria, AMPs could be involved in controlling its symbiotic systems (endosymbiont and microbiota). We found that the IMD pathway was active in the adult female transcriptomes of six tissues (salivary glands, foregut, midgut, hindgut, Malpighian tubules and fat body) and hemolymph. Total expression of AMP genes was high in hemolymph and salivary glands and much lower in the other sample types. The expression of specific AMP genes was very heterogeneous among sample types. Two genes, defensin_g10 and drosomycin_g5, displayed relevant expression in the seven sample types, although higher in hemolymph. Other genes only displayed high expression in one tissue. Almost no expression of attacin-like and blattellicin genes was observed in any sample type, although some of them were among the genes with the highest expression in adult female whole bodies. The expression of AMP genes in salivary glands could help control pathogens ingested with food and even determine gut microbiota composition. The low expression levels in midgut and hindgut are probably related to the presence of beneficial microbiota. Furthermore, a reduction in the expression of AMP genes in fat body could be the way to prevent damage to the population of the endosymbiont Blattabacterium cuenoti within bacteriocytes.}, }
@article {pmid35945408, year = {2022}, author = {Hirunkanokpun, S and Ahantarig, A and Baimai, V and Pramual, P and Rakthong, P and Trinachartvanit, W}, title = {Spotted fever group Rickettsia, Anaplasma and Coxiella-like endosymbiont in Haemaphysalis ticks from mammals in Thailand.}, journal = {Veterinary research communications}, volume = {46}, number = {4}, pages = {1209-1219}, pmid = {35945408}, issn = {1573-7446}, mesh = {Animals ; Male ; *Rickettsia/genetics ; *Ticks/genetics/microbiology ; RNA, Ribosomal, 16S/genetics ; Phylogeny ; Thailand ; Ferrets ; DNA, Bacterial/genetics ; *Ixodidae/genetics/microbiology ; Anaplasma/genetics ; Coxiella/genetics ; *Spotted Fever Group Rickettsiosis/veterinary ; }, abstract = {Ticks are ectoparasites of vertebrates and vectors of various pathogenic microorganisms. In this study, the presence of bacteria and protozoa was evaluated by PCR and DNA sequencing in 233 mammal ticks collected from 8 provinces in Thailand. Sequence and phylogenetic analyses of partial rickettsial ompA, ompB, sca4 and partial Coxiella 16S rRNA, GroEL, rpoB genes clearly revealed, for the first time, a co-infection of SFG Rickettsia belonging to R. massiliae subgroup and Coxiella-like endosymbiont (CLE), Cox-hein, in a male of Haemaphysalis heinrichi tick infesting Burmese ferret-badger in Loei province. Moreover, a male of H. hystricis tick infesting the same host was infected with another CLE, Cox-hys. Based on the 16S rRNA gene sequence, Anaplasma sp., closely related to Anaplasma bovis was also detected in a male of H. heinrichi infesting the same Burmese ferret-badger. In addition, the third CLE, Cox-asia, found in H. asiatica collected from Asian palm civet in Chiang Rai province, was different from both Cox-hein and Cox-hys. This study provided important data and broadened our knowledge on tick-borne pathogens and endosymbionts in Thailand and Southeast Asia.}, }
@article {pmid35930552, year = {2022}, author = {Gao, RF and Wang, Y and Wang, Y and Wang, ZW and Zhang, GM}, title = {Genome insights from the identification of a novel Pandoraea sputorum isolate and its characteristics.}, journal = {PloS one}, volume = {17}, number = {8}, pages = {e0272435}, pmid = {35930552}, issn = {1932-6203}, mesh = {*Burkholderiaceae/genetics ; Phylogeny ; Quorum Sensing ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {In this study, we sequenced a bacteria isolate Pandoraea sp. 892iso isolated from a Phytophthora rubi strain which is an important plant pathogenic oomycete, identified through genome and combined the data with existing genomic data from other 28 the genus of Pandoraea species. Next, we conducted a comparative genomic analysis of the genome structure, evolutionary relationships, and pathogenic characteristics of Pandoraea species. Our results identified Pandoraea sp. 892iso as Pandoraea sputorum at both the genome and gene levels. At the genome level, we carried out phylogenetic analysis of single-copy, gene co-linearity, ANI (average nucleotide identity) and AAI (average amino acid identity) indices, rpoB similarity, MLSA phylogenetic analysis, and genome-to-genome distance calculator calculations to identify the relationship between Pandoraea sp. 892iso and P. sputorum. At the gene level, the quorum sensing genes ppnI and ppnR and the OXA-159 gene were assessed. It is speculated that Pandoraea sp. 892iso is the endosymbiont of the Oomycetes strain of Phytophthora rubi.}, }
@article {pmid35925827, year = {2023}, author = {Kwak, Y and Argandona, JA and Degnan, PH and Hansen, AK}, title = {Chromosomal-level assembly of Bactericera cockerelli reveals rampant gene family expansions impacting genome structure, function and insect-microbe-plant-interactions.}, journal = {Molecular ecology resources}, volume = {23}, number = {1}, pages = {233-252}, doi = {10.1111/1755-0998.13693}, pmid = {35925827}, issn = {1755-0998}, mesh = {Animals ; *Hemiptera/genetics ; Symbiosis/genetics ; Genome ; Bacteria/genetics ; Chromosomes ; }, abstract = {Lineage specific expansions and gene duplications are some of the most important sources of evolutionary novelty in eukaryotes. Although not as prevalent in eukaryotes compared to bacteria, horizontal gene transfer events can also result in key adaptations for insects, especially for those involved in insect-microbe interactions. In this study we assemble the first chromosomal assembly of the psyllid Bactericera cockerelli and reveal that the B. cockerelli genome has experienced significantly more gene expansion events compared to other Hemipteran representatives with fully sequenced genomes. We also reveal that B. cockerelli's genome is the largest psyllid genome (567 Mb) sequenced to date and is ~15% larger than the other two psyllid species genomes sequenced (Pachypsylla venusta and Diaphorina citri). Structurally, B. cockerelli appears to have an additional chromosome compared to the distantly related psyllid species P. venusta due to a previous chromosomal fission or fusion event. The increase in genome size and dynamic nature of the B. cockerelli genome may largely be contributed to the widespread expansion of type I and II repeat elements that are rampant across all of B. cockerelli's. chromosomes. These repeat elements are distributed near equally in both euchromatic and heterochromatic regions. Furthermore, significant gene family expansions and gene duplications were uncovered for genes that are expected to be important in its adaptation to insect-plant and microbe interactions, which include transcription factors, proteases, odorant receptors, and horizontally transferred genes that are involved in the nutritional symbioses with their long-term nutritional endosymbiont Carsonella.}, }
@article {pmid35923389, year = {2022}, author = {Tibbs-Cortes, LE and Tibbs-Cortes, BW and Schmitz-Esser, S}, title = {Tardigrade Community Microbiomes in North American Orchards Include Putative Endosymbionts and Plant Pathogens.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {866930}, pmid = {35923389}, issn = {1664-302X}, abstract = {The microbiome of tardigrades, a phylum of microscopic animals best known for their ability to survive extreme conditions, is poorly studied worldwide and completely unknown in North America. An improved understanding of tardigrade-associated bacteria is particularly important because tardigrades have been shown to act as vectors of the plant pathogen Xanthomonas campestris in the laboratory. However, the potential role of tardigrades as reservoirs and vectors of phytopathogens has not been investigated further. This study analyzed the microbiota of tardigrades from six apple orchards in central Iowa, United States, and is the first analysis of the microbiota of North American tardigrades. It is also the first ever study of the tardigrade microbiome in an agricultural setting. We utilized 16S rRNA gene amplicon sequencing to characterize the tardigrade community microbiome across four contrasts: location, substrate type (moss or lichen), collection year, and tardigrades vs. their substrate. Alpha diversity of the tardigrade community microbiome differed significantly by location and year of collection but not by substrate type. Our work also corroborated earlier findings, demonstrating that tardigrades harbor a distinct microbiota from their environment. We also identified tardigrade-associated taxa that belong to genera known to contain phytopathogens (Pseudomonas, Ralstonia, and the Pantoea/Erwinia complex). Finally, we observed members of the genera Rickettsia and Wolbachia in the tardigrade microbiome; because these are obligate intracellular genera, we consider these taxa to be putative endosymbionts of tardigrades. These results suggest the presence of putative endosymbionts and phytopathogens in the microbiota of wild tardigrades in North America.}, }
@article {pmid35916900, year = {2022}, author = {Jin, C and Mo, Y and Zhao, L and Xiao, Z and Zhu, S and He, Z and Chen, Z and Zhang, M and Shu, L and Qiu, R}, title = {Host-Endosymbiont Relationship Impacts the Retention of Bacteria-Containing Amoeba Spores in Porous Media.}, journal = {Environmental science &amp; technology}, volume = {56}, number = {17}, pages = {12347-12357}, doi = {10.1021/acs.est.2c02899}, pmid = {35916900}, issn = {1520-5851}, mesh = {*Amoeba/microbiology ; *Dictyostelium/metabolism/microbiology ; Porosity ; Spores, Bacterial ; Symbiosis ; }, abstract = {Amoebae are protists that are commonly found in water, soil, and other habitats around the world and have complex interactions with other microorganisms. In this work, we investigated how host-endosymbiont interactions between amoebae and bacteria impacted the retention behavior of amoeba spores in porous media. A model amoeba species, Dictyostelium discoideum, and a representative bacterium, Burkholderia agricolaris B1qs70, were used to prepare amoeba spores that carried bacteria. After interacting with B. agricolaris, the retention of D. discoideum spores was enhanced compared to noninfected spores. Diverse proteins, especially proteins contributing to the looser exosporium structure and cell adhesion functionality, are secreted in higher quantities on the exosporium surface of infected spores compared to that of noninfected ones. Comprehensive examinations using a quartz crystal microbalance with dissipation (QCM-D), a parallel plate chamber, and a single-cell force microscope present coherent evidence that changes in the exosporium of D. discoideum spores due to infection by B. agricolaris enhance the connections between spores in the suspension and the spores that were previously deposited on the collector surface, thus resulting in more retention compared to the uninfected ones in porous media. This work provides novel insight into the retention of amoeba spores after bacterial infection in porous media and suggests that the host-endosymbiont relationship regulates the fate of biocolloids in drinking water systems, groundwater, and other porous environments.}, }
@article {pmid35916448, year = {2022}, author = {Wang, J and Gou, QY and Luo, GY and Hou, X and Liang, G and Shi, M}, title = {Total RNA sequencing of Phlebotomus chinensis sandflies in China revealed viral, bacterial, and eukaryotic microbes potentially pathogenic to humans.}, journal = {Emerging microbes &amp; infections}, volume = {11}, number = {1}, pages = {2080-2092}, pmid = {35916448}, issn = {2222-1751}, support = {U01 AI151810/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics ; Eukaryota/genetics ; Humans ; Mammals ; *Phlebotomus/genetics ; *Phlebovirus/genetics ; *Psychodidae/genetics ; RNA ; Sequence Analysis, RNA ; }, abstract = {Phlebotomus chinensis sandfly is a neglected insect vector in China that is well-known for carrying Leishmania. Recent studies have expanded its pathogen repertoire with two novel arthropod-borne phleboviruses capable of infecting humans and animals. Despite these discoveries, our knowledge of the general pathogen diversity and overall microbiome composition of this vector species is still very limited. Here we carried out a meta-transcriptomics analysis that revealed the actively replicating/transcribing RNA viruses, DNA viruses, bacteria, and eukaryotic microbes, namely, the "total microbiome", of several sandfly populations in China. Strikingly, "microbiome" made up 1.8% of total non-ribosomal RNA and comprised more than 87 species, among which 70 were novel, including divergent members of the genera Flavivirus and of the family Trypanosomatidae. Importantly, among these microbes we were able to reveal four distinguished types of human and/or mammalian pathogens, including two phleboviruses (hedi and wuxiang viruses), one novel Spotted fever group rickettsia, as well as a member of Leishmania donovani complex, among which hedi virus and Leishmania each had > 50% pool prevalence rate and relatively high abundance levels. Our study also showed the ubiquitous presence of an endosymbiont, namely Wolbachia, although no anti-viral or anti-pathogen effects were detected based on our data. In summary, our results uncovered the much un-explored diversity of microbes harboured by sandflies in China and demonstrated that high pathogen diversity and abundance are currently present in multiple populations, implying disease potential for exposed local human population or domestic animals.}, }
@article {pmid35914568, year = {2022}, author = {Rosário, AAD and Dias-Lima, AG and Lambert, SM and Souza, BMPDS and Bravo, F}, title = {Identification and molecular characterization of Wolbachia strains and natural infection for Leishmania sp. in neotropical Phlebotominae (Diptera: Psychodidae) species, leishmaniasis vectors.}, journal = {Acta tropica}, volume = {235}, number = {}, pages = {106624}, doi = {10.1016/j.actatropica.2022.106624}, pmid = {35914568}, issn = {1873-6254}, mesh = {Animals ; Brazil ; Insect Vectors/parasitology ; *Leishmania infantum/genetics ; *Leishmaniasis ; *Parasites ; *Psychodidae/parasitology ; *Wolbachia/genetics ; }, abstract = {Recently, Wolbachia infection has been described in leishmaniasis vector sandflies. This endosymbiont bacterium is present in 60% of insects, and has been suggested as a mechanism of biological control of vector insects, because it causes a series of changes in the invertebrate host. In addition, recent studies have shown that this bacterium can prevent the development of parasites in vector insects. In this context, the present study aims to molecularly characterize the circulating strain of this bacterium in sandflies in the State of Bahia, Brazil, as well as the natural infection rate of Leishmania sp., and to evaluate the coinfection between Wolbachia and Leishmania. Seven hundred and forty-five (745) specimens of sandflies were collected in nine municipalities of Bahia, belonging to two species, Lutzomyia longipalpis (Lutz and Neiva, 1912) and Nyssomyia whitmani (Antunes and Coutinho, 1939). The results confirm infection by the protozoan Leishmania infantum and Wolbachia in both species collected. The identified strain of Wolbachia in sandflies was wStv MI, known to lead to a phenotype of cytoplasmic incompatibility in vector insects.}, }
@article {pmid35913594, year = {2022}, author = {Patra, AK and Kwon, YM and Yang, Y}, title = {Complete gammaproteobacterial endosymbiont genome assembly from a seep tubeworm Lamellibrachia satsuma.}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {60}, number = {9}, pages = {916-927}, pmid = {35913594}, issn = {1976-3794}, mesh = {Animals ; Bacteria/genetics ; *Hydrothermal Vents/microbiology ; *Microbiota ; *Polychaeta/genetics/microbiology ; Symbiosis ; }, abstract = {Siboglinid tubeworms thrive in hydrothermal vent and seep habitats via a symbiotic relationship with chemosynthetic bacteria. Difficulties in culturing tubeworms and their symbionts in a laboratory setting have hindered the study of host-microbe interactions. Therefore, released symbiont genomes are fragmented, thereby limiting the data available on the genome that affect subsequent analyses. Here, we present a complete genome of gammaproteobacterial endosymbiont from the tubeworm Lamellibrachia satsuma collected from a seep in Kagoshima Bay, assembled using a hybrid approach that combines sequences generated from the Illumina and Oxford Nano-pore platforms. The genome consists of a single circular chromosome with an assembly size of 4,323,754 bp and a GC content of 53.9% with 3,624 protein-coding genes. The genome is of high quality and contains no assembly gaps, while the completeness and contamination are 99.33% and 2.73%, respectively. Comparative genome analysis revealed a total of 1,724 gene clusters shared in the vent and seep tubeworm symbionts, while 294 genes were found exclusively in L. satsuma symbionts such as transposons, genes for defense mechanisms, and inorganic ion transportations. The addition of this complete endosymbiont genome assembly would be valuable for comparative studies particularly with tubeworm symbiont genomes as well as with other chemosynthetic microbial communities.}, }
@article {pmid35906526, year = {2022}, author = {Gabriel, E and Krauß, N and Lamparter, T}, title = {Evidence for evolutionary relationship between archaeplastidal and cyanobacterial phytochromes based on their chromophore pockets.}, journal = {Photochemical &amp; photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology}, volume = {21}, number = {11}, pages = {1961-1974}, pmid = {35906526}, issn = {1474-9092}, mesh = {*Phytochrome/chemistry ; Phylogeny ; *Cyanobacteria/chemistry ; Biological Evolution ; Plants/metabolism ; Amino Acids/metabolism ; Bacterial Proteins/chemistry ; }, abstract = {Phytochromes are photoreceptor proteins with a bilin chromophore that undergo photoconversion between two spectrally different forms, Pr and Pfr. In plants, phytochromes play a central role in growth and differentiation during the entire life cycle. Phytochromes of plants and other groups of archaeplastida have a common evolutionary origin in prokaryotes, but the exact prokaryotic origin is as yet uncertain. Two possibilities are presently discussed: either, archaeplastidal phytochromes arose from the last eukaryotic common ancestor (LECA) or they arose from the cyanobacterial endosymbiont that gave rise to plastids. We first constructed standard phylogenetic trees based on N-terminal protein sequences of the chromophore module. As usual, variation of algorithms and parameters led to different trees. A relationship between cyanobacteria and archaeplastida was observed in 7 out of 36 trees. The lack of consistency between results obtained from variation of parameters of tree constructions reflects the uncertainty of archaeplastidal origin. To gain more information about a possible cyanobacterial and archaeplastidal relationship, we performed phylogenetic studies based on the amino acids that line the chromophore pockets. These amino acids are highly conserved and could provide more accurate information about long evolutionary time scales, but the reduction of traits could also lead to insignificant results. From 30 selected chromophore-binding amino acids, 6 were invariant. The subsequent studies were thus based on the information dependent on 24 or fewer amino acid positions. Again, multiple trees were constructed to get information about the robustness of relationships. The very low number of information-containing traits resulted in low bootstrap values and many indistinguishable leaves. However, the major groups fungi, bacteria, cyanobacteria, and plants remained united. Without exception, cyanobacteria and archaeplastida were always closely linked. In this respect, the results were more robust than those of the classic approach, based on long contiguous sequences. We therefore consider cyanobacteria as the most likely origin of archaeplastidal phytochromes.}, }
@article {pmid35898209, year = {2022}, author = {Matsuo, E and Morita, K and Nakayama, T and Yazaki, E and Sarai, C and Takahashi, K and Iwataki, M and Inagaki, Y}, title = {Comparative Plastid Genomics of Green-Colored Dinoflagellates Unveils Parallel Genome Compaction and RNA Editing.}, journal = {Frontiers in plant science}, volume = {13}, number = {}, pages = {918543}, pmid = {35898209}, issn = {1664-462X}, abstract = {Dinoflagellates possess plastids that are diverse in both pigmentation and evolutionary background. One of the plastid types found in dinoflagellates is pigmented with chlorophylls a and b (Chl a + b) and originated from the endosymbionts belonging to a small group of green algae, Pedinophyceae. The Chl a + b-containing plastids have been found in three distantly related dinoflagellates Lepidodinium spp., strain MGD, and strain TGD, and were proposed to be derived from separate partnerships between a dinoflagellate (host) and a pedinophycean green alga (endosymbiont). Prior to this study, a plastid genome sequence was only available for L. chlorophorum, which was reported to bear the features that were not found in that of the pedinophycean green alga Pedinomonas minor, a putative close relative of the endosymbiont that gave rise to the current Chl a + b-containing plastid. In this study, we sequenced the plastid genomes of strains MGD and TGD to compare with those of L. chlorophorum as well as pedinophycean green algae. The mapping of the RNA-seq reads on the corresponding plastid genome identified RNA editing on plastid gene transcripts in the three dinoflagellates. Further, the comparative plastid genomics revealed that the plastid genomes of the three dinoflagellates achieved several features, which are not found in or much less obvious than the pedinophycean plastid genomes determined to date, in parallel.}, }
@article {pmid35895627, year = {2022}, author = {Calle-Tobón, A and Pérez-Pérez, J and Forero-Pineda, N and Chávez, OT and Rojas-Montoya, W and Rúa-Uribe, G and Gómez-Palacio, A}, title = {Local-scale virome depiction in Medellín, Colombia, supports significant differences between Aedes aegypti and Aedes albopictus.}, journal = {PloS one}, volume = {17}, number = {7}, pages = {e0263143}, pmid = {35895627}, issn = {1932-6203}, mesh = {*Aedes/classification/virology ; Animals ; Colombia ; *Insect Viruses/genetics ; Mosquito Vectors/virology ; *RNA Viruses/genetics ; *Virome/genetics ; Wolbachia/genetics ; }, abstract = {Aedes spp. comprise the primary group of mosquitoes that transmit arboviruses such as dengue, Zika, and chikungunya viruses to humans, and thus these insects pose a significant burden on public health worldwide. Advancements in next-generation sequencing and metagenomics have expanded our knowledge on the richness of RNA viruses harbored by arthropods such as Ae. aegypti and Ae. albopictus. Increasing evidence suggests that vector competence can be modified by the microbiome (comprising both bacteriome and virome) of mosquitoes present in endemic zones. Using an RNA-seq-based metataxonomic approach, this study determined the virome structure, Wolbachia presence and mitochondrial diversity of field-caught Ae. aegypti and Ae. albopictus mosquitoes in Medellín, Colombia, a municipality with a high incidence of mosquito-transmitted arboviruses. The two species are sympatric, but their core viromes differed considerably in richness, diversity, and abundance; although the community of viral species identified was large and complex, the viromes were dominated by few virus species. BLAST searches of assembled contigs suggested that at least 17 virus species (16 of which are insect-specific viruses [ISVs]) infect the Ae. aegypti population. Dengue virus 3 was detected in one sample and it was the only pathogenic virus detected. In Ae. albopictus, up to 11 ISVs and one plant virus were detected. Therefore, the virome composition appears to be species-specific. The bacterial endosymbiont Wolbachia was identified in all Ae. albopictus samples and in some Ae. aegypti samples collected after 2017. The presence of Wolbachia sp. in Ae. aegypti was not related to significant changes in the richness, diversity, or abundance of this mosquito's virome, although it was related to an increase in the abundance of Aedes aegypti To virus 2 (Metaviridae). The mitochondrial diversity of these mosquitoes suggested that the Ae. aegypti population underwent a change that started in the second half of 2017, which coincides with the release of Wolbachia-infected mosquitoes in Medellín, indicating that the population of wMel-infected mosquitoes released has introduced new alleles into the wild Ae. aegypti population of Medellín. However, additional studies are required on the dispersal speed and intergenerational stability of wMel in Medellín and nearby areas as well as on the introgression of genetic variants in the native mosquito population.}, }
@article {pmid35889112, year = {2022}, author = {Hoffman, T and Sjödin, A and Öhrman, C and Karlsson, L and McDonough, RF and Sahl, JW and Birdsell, D and Wagner, DM and Carra, LG and Wilhelmsson, P and Pettersson, JH and Barboutis, C and Figuerola, J and Onrubia, A and Kiat, Y and Piacentini, D and Jaenson, TGT and Lindgren, PE and Moutailler, S and Fransson, T and Forsman, M and Nilsson, K and Lundkvist, &#xc5; and Olsen, B}, title = {Co-Occurrence of Francisella, Spotted Fever Group Rickettsia, and Midichloria in Avian-Associated Hyalomma rufipes.}, journal = {Microorganisms}, volume = {10}, number = {7}, pages = {}, pmid = {35889112}, issn = {2076-2607}, abstract = {The migratory behavior of wild birds contributes to the geographical spread of ticks and their microorganisms. In this study, we aimed to investigate the dispersal and co-occurrence of Francisella and spotted fever group Rickettsia (SFGR) in ticks infesting birds migrating northward in the African-Western Palaearctic region (AWPR). Birds were trapped with mist nests across the Mediterranean basin during the 2014 and 2015 spring migration. In total, 575 ticks were collected from 244 birds. We screened the ticks for the species Francisella tularensis, the genus Francisella, and SFGR by microfluidic real-time PCR. Confirmatory analyses and metagenomic sequencing were performed on tick samples that putatively tested positive for F. tularensis during initial screenings. Hyalomma rufipes was the most common tick species and had a high prevalence of Francisella, including co-occurrence of Francisella and SFGR. Metagenomic analysis of total DNA extracted from two H. rufipes confirmed the presence of Francisella, Rickettsia, and Midichloria. Average nucleotide identity and phylogenetic inference indicated the highest identity of the metagenome-assembled genomes to a Francisella-like endosymbiont (FLE), Rickettsia aeschlimannii, and Midichloria mitochondrii. The results of this study suggest that (i) FLE- and SFGR-containing ticks are dispersed by northbound migratory birds in the AWPR, (ii) H. rufipes likely is not involved in transmission of F. tularensis in the AWPR, and (iii) a dual endosymbiosis of FLEs and Midichloria may support some of the nutritional requirements of H. rufipes.}, }
@article {pmid35889091, year = {2022}, author = {Mendoza-Hoffmann, F and Zarco-Zavala, M and Ortega, R and Celis-Sandoval, H and Torres-Larios, A and García-Trejo, JJ}, title = {Evolution of the Inhibitory and Non-Inhibitory ε, ζ, and IF1 Subunits of the F1FO-ATPase as Related to the Endosymbiotic Origin of Mitochondria.}, journal = {Microorganisms}, volume = {10}, number = {7}, pages = {}, pmid = {35889091}, issn = {2076-2607}, abstract = {The F1FO-ATP synthase nanomotor synthesizes >90% of the cellular ATP of almost all living beings by rotating in the "forward" direction, but it can also consume the same ATP pools by rotating in "reverse." To prevent futile F1FO-ATPase activity, several different inhibitory proteins or domains in bacteria (ε and ζ subunits), mitochondria (IF1), and chloroplasts (ε and γ disulfide) emerged to block the F1FO-ATPase activity selectively. In this study, we analyze how these F1FO-ATPase inhibitory proteins have evolved. The phylogeny of the α-proteobacterial ε showed that it diverged in its C-terminal side, thus losing both the inhibitory function and the ATP-binding/sensor motif that controls this inhibition. The losses of inhibitory function and the ATP-binding site correlate with an evolutionary divergence of non-inhibitory α-proteobacterial ε and mitochondrial δ subunits from inhibitory bacterial and chloroplastidic ε subunits. Here, we confirm the lack of inhibitory function of wild-type and C-terminal truncated ε subunits of P. denitrificans. Taken together, the data show that ζ evolved to replace ε as the primary inhibitor of the F1FO-ATPase of free-living α-proteobacteria. However, the ζ inhibitory function was also partially lost in some symbiotic α-proteobacteria and totally lost in some strictly parasitic α-proteobacteria such as the Rickettsiales order. Finally, we found that ζ and IF1 likely evolved independently via convergent evolution before and after the endosymbiotic origin mitochondria, respectively. This led us to propose the ε and ζ subunits as tracer genes of the pre-endosymbiont that evolved into the actual mitochondria.}, }
@article {pmid35887442, year = {2022}, author = {Chen, C and Qi, J and He, Y and Lu, Y and Wang, Y}, title = {Genomic and Chemical Profiling of B9, a Unique Penicillium Fungus Derived from Sponge.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {8}, number = {7}, pages = {}, pmid = {35887442}, issn = {2309-608X}, abstract = {This study presented the first insights into the genomic and chemical profiles of B9, a specific Penicillium strain derived from sponges of the South China Sea that demonstrated the closest morphological and phylogenetic affinity to P. paxillin. Via the Illumina MiSeq sequencing platform, the draft genome was sequenced, along with structural assembly and functional annotation. There were 34 biosynthetic gene clusters (BGCs) predicted against the antiSMASH database, but only 4 gene clusters could be allocated to known BGCs (≥50% identities). Meanwhile, the comparison between B9 and P. paxillin ATCC 10480 demonstrated clear distinctions in morphology, which might be ascribed to the unique environmental adaptability of marine endosymbionts. In addition, two novel pyridinones, penicidihydropyridone A (2) and penicidihydropyridone B (3), were isolated from cultures of B9, and structurally characterized by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The absolute configurations were confirmed by comparison of experimental and calculated electronic circular dichroism (ECD) curves. In addition, structure-based molecular docking indicated that both neo-pyridinones might block the programmed cell death protein 1(PD-1) pathway by competitively binding a programmed cell death 1 ligand 1(PD-L1) dimer. This was verified by the significant inhibition rates of the PD-1/L1 interaction. These indicated that Penicillium sp. B9 possessed a potential source of active secondary metabolites.}, }
@article {pmid35876309, year = {2022}, author = {Schuler, H and Dittmer, J and Borruso, L and Galli, J and Fischnaller, S and Anfora, G and Rota-Stabelli, O and Weil, T and Janik, K}, title = {Investigating the microbial community of Cacopsylla spp. as potential factor in vector competence of phytoplasma.}, journal = {Environmental microbiology}, volume = {24}, number = {10}, pages = {4771-4786}, doi = {10.1111/1462-2920.16138}, pmid = {35876309}, issn = {1462-2920}, mesh = {Animals ; *Hemiptera/microbiology ; *Malus/microbiology ; *Microbiota/genetics ; *Phytoplasma/genetics ; Plant Diseases/microbiology ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Phytoplasmas are obligatory intracellular bacteria that colonize the phloem of many plant species and cause hundreds of plant diseases worldwide. In nature, phytoplasmas are primarily transmitted by hemipteran vectors. While all phloem-feeding insects could in principle transmit phytoplasmas, only a limited number of species have been confirmed as vectors. Knowledge about factors that might determine the vector capacity is currently scarce. Here, we characterized the microbiomes of vector and non-vector species of apple proliferation (AP) phytoplasma 'Candidatus Phytoplasma mali' to investigate their potential role in the vector capacity of the host. We performed high-throughput 16S rRNA metabarcoding of the two principal AP-vectors Cacopsylla picta and Cacopsylla melanoneura and eight Cacopsylla species, which are not AP-vectors but co-occur in apple orchards. The microbiomes of all species are dominated by Carsonella, the primary endosymbiont of psyllids and a second uncharacterized Enterobacteriaceae endosymbiont. Each Cacopsylla species harboured a species-specific phylotype of both symbionts. Moreover, we investigated differences between the microbiomes of AP-vector versus non-vector species and identified the predominant endosymbionts but also Wolbachia and several minor taxa as potential indicator species. Our study highlights the importance of considering the microbiome in future investigations of potential factors influencing host vector competence. We investigated the potential role of symbiotic bacteria in the acquisition and transmission of phytoplasma. By comparing the two main psyillid vector species of Apple proliferation (AP) phytoplasma and eight co-occurring species, which are not able to vector AP-phytoplasma, we found differences in the microbial communities of AP-vector and non-vector species, which appear to be driven by the predominant symbionts in both vector species and Wolbachia and several minor taxa in the non-vector species. In contrast, infection with AP-phytoplasma did not affect microbiome composition in both vector species. Our study provides new insights into the endosymbiont diversity of Cacopsylla spp. and highlights the importance of considering the microbiome when investigating potential factors influencing host vector competence.}, }
@article {pmid35876244, year = {2022}, author = {Sawadogo, SP and Kabore, DA and Tibiri, EB and Hughes, A and Gnankine, O and Quek, S and Diabaté, A and Ranson, H and Hughes, GL and Dabiré, RK}, title = {Lack of robust evidence for a Wolbachia infection in Anopheles gambiae from Burkina Faso.}, journal = {Medical and veterinary entomology}, volume = {36}, number = {3}, pages = {301-308}, doi = {10.1111/mve.12601}, pmid = {35876244}, issn = {1365-2915}, support = {MR/P027873/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; *Anopheles/genetics ; Burkina Faso ; *Malaria/veterinary ; Mosquito Vectors ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Wolbachia/genetics ; }, abstract = {The endosymbiont Wolbachia can have major effects on the reproductive fitness, and vectorial capacity of host insects and may provide new avenues to control mosquito-borne pathogens. Anopheles gambiae s.l is the major vector of malaria in Africa but the use of Wolbachia in this species has been limited by challenges in establishing stable transinfected lines and uncertainty around native infections. High frequencies of infection of Wolbachia have been previously reported in An. gambiae collected from the Valle du Kou region of Burkina Faso in 2011 and 2014. Here, we re-evaluated the occurrence of Wolbachia in natural samples, collected from Valle du Kou over a 12-year time span, and in addition, expanded sampling to other sites in Burkina Faso. Our results showed that, in contrast to earlier reports, Wolbachia is present at an extremely low prevalence in natural population of An. gambiae. From 5341 samples analysed, only 29 were positive for Wolbachia by nested PCR representing 0.54% of prevalence. No positive samples were found with regular PCR. Phylogenetic analysis of 16S rRNA gene amplicons clustered across supergroup B, with some having similarity to sequences previously found in Anopheles from Burkina Faso. However, we cannot discount the possibility that the amplicon positive samples we detected were due to environmental contamination or were false positives. Regardless, the lack of a prominent native infection in An. gambiae s.l. is encouraging for applications utilizing Wolbachia transinfected mosquitoes for malaria control.}, }
@article {pmid35873163, year = {2022}, author = {Ramos, LFC and Martins, M and Murillo, JR and Domont, GB and de Oliveira, DMP and Nogueira, FCS and Maciel-de-Freitas, R and Junqueira, M}, title = {Interspecies Isobaric Labeling-Based Quantitative Proteomics Reveals Protein Changes in the Ovary of Aedes aegypti Coinfected With ZIKV and Wolbachia.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {900608}, pmid = {35873163}, issn = {2235-2988}, mesh = {*Aedes/microbiology ; Animals ; *Coinfection ; Female ; Humans ; Infant, Newborn ; Mosquito Vectors ; Ovary ; Proteomics ; *Wolbachia ; *Zika Virus ; *Zika Virus Infection ; }, abstract = {Zika is a vector-borne disease caused by an arbovirus (ZIKV) and overwhelmingly transmitted by Ae. aegypti. This disease is linked to adverse fetal outcomes, mostly microcephaly in newborns, and other clinical aspects such as acute febrile illness and neurologic complications, for example, Guillain-Barré syndrome. One of the most promising strategies to mitigate arbovirus transmission involves releasing Ae. aegypti mosquitoes carrying the maternally inherited endosymbiont bacteria Wolbachia pipientis. The presence of Wolbachia is associated with a reduced susceptibility to arboviruses and a fitness cost in mosquito life-history traits such as fecundity and fertility. However, the mechanisms by which Wolbachia influences metabolic pathways leading to differences in egg production remains poorly known. To investigate the impact of coinfections on the reproductive tract of the mosquito, we applied an isobaric labeling-based quantitative proteomic strategy to investigate the influence of Wolbachia wMel and ZIKV infection in Ae. aegypti ovaries. To the best of our knowledge, this is the most complete proteome of Ae. aegypti ovaries reported so far, with a total of 3913 proteins identified, were also able to quantify 1044 Wolbachia proteins in complex sample tissue of Ae. aegypti ovary. Furthermore, from a total of 480 mosquito proteins modulated in our study, we discuss proteins and pathways altered in Ae. aegypti during ZIKV infections, Wolbachia infections, coinfection Wolbachia/ZIKV, and compared with no infection, focusing on immune and reproductive aspects of Ae. aegypti. The modified aspects mainly were related to the immune priming enhancement by Wolbachia presence and the modulation of the Juvenile Hormone pathway caused by both microorganism's infection.}, }
@article {pmid35869302, year = {2022}, author = {Mejia, AJ and Jimenez, L and Dutra, HLC and Perera, R and McGraw, EA}, title = {Attempts to use breeding approaches in Aedes aegypti to create lines with distinct and stable relative Wolbachia densities.}, journal = {Heredity}, volume = {129}, number = {4}, pages = {215-224}, pmid = {35869302}, issn = {1365-2540}, mesh = {*Aedes/genetics ; Animals ; Mosquito Vectors/genetics ; Specific Gravity ; Virus Replication ; *Wolbachia/genetics ; *Zika Virus ; *Zika Virus Infection ; }, abstract = {Wolbachia is an insect endosymbiont being used for biological control in the mosquito Aedes aegypti because it causes cytoplasmic incompatibility (CI) and limits viral replication of dengue, chikungunya, and Zika viruses. While the genetic mechanism of pathogen blocking (PB) is not fully understood, the strength of both CI and PB are positively correlated with Wolbachia densities in the host. Wolbachia densities are determined by a combination of Wolbachia strain and insect genotype, as well as interactions with the environment. We employed both artificial selection and inbreeding with the goal of creating lines of Ae. aegypti with heritable and distinct Wolbachia densities so that we might better dissect the mechanism underlying PB. We were unable to shift the mean relative Wolbachia density in Ae. aegypti lines by either strategy, with relative densities instead tending to cycle over a narrow range. In lieu of this, we used Wolbachia densities in mosquito legs as predictors of relative densities in the remaining individual's carcass. Because we worked with outbred mosquitoes, our findings indicate either a lack of genetic variation in the mosquito for controlling relative density, natural selection against extreme densities, or a predominance of environmental factors affecting densities. Our study reveals that there are moderating forces acting on relative Wolbachia densities that may help to stabilize density phenotypes post field release. We also show a means to accurately bin vector carcasses into high and low categories for non-DNA omics-based studies of Wolbachia-mediated traits.}, }
@article {pmid35868196, year = {2022}, author = {Zhang, XY and Li, SS and Chen, KL and Yang, C and Zhou, XJ and Liu, JZ and Zhang, YK}, title = {Growth dynamics and tissue localization of a Coxiella-like endosymbiont in the tick Haemaphysalis longicornis.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {5}, pages = {102005}, doi = {10.1016/j.ttbdis.2022.102005}, pmid = {35868196}, issn = {1877-9603}, mesh = {Animals ; Coxiella/genetics ; Female ; In Situ Hybridization, Fluorescence ; *Ixodidae/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Ticks/genetics ; }, abstract = {A Coxiella-like endosymbiont (Coxiella-LE hereinafter) stably infects and influences Haemaphysalis longicornis development, indicating a mutualistic relationship of Coxiella-LE and ticks. To further elucidate the patterns of growth dynamics and tissue localization of Coxiella-LE in H. longicornis, 16S rRNA high-throughput sequencing, quantitative PCR (qPCR), and fluorescence in situ hybridization (FISH) were used in this study. The density of Coxiella-LE varied among different tick life stages, and fed female ticks had the highest density, followed by unfed female and unfed larval ticks. In the four organs that were dissected from fed female ticks, the ovary carried the highest density of Coxiella-LE, which was significantly different from salivary glands, midgut and Malpighian tubules. The high abundance of Coxiella-LE in fed female ticks and in the ovaries of fed female ticks in the bacterial microbiota analyses further confirmed that Coxiella-LE rapidly proliferates in the ovary after blood feeding. The ovaries continued to develop after engorgement and oviposition began on day 5, with a significant decrease in the density of Coxiella-LE in the ovaries occurring on day 7. FISH results indicated that Coxiella-LE is mainly colonized in the cytoplasm of the oocyte and proliferates with oogenesis. Coxiella-LE was expelled from the body with the mature oocyte, ensuring its vertical transmission. In the Malpighian tubules at different days after engorgement, the white flocculent materials were increasing, and the density of Coxiella-LE raised significantly on day 7. Unlike the localization pattern in the ovary, Coxiella-LE was initially distributed in a mass and continually increased during the development of Malpighian tubules until it filled the Malpighian tubules. These findings provide new insights on the growth dynamics and tissue localization of Coxiella-LE in ticks and are useful for further investigation on the interactions of symbiont and ticks .}, }
@article {pmid35866313, year = {2022}, author = {Chirgwin, E and Yang, Q and Umina, PA and Gill, A and Soleimannejad, S and Gu, X and Ross, P and Hoffmann, AA}, title = {Fungicides have transgenerational effects on Rhopalosiphum padi but not their endosymbionts.}, journal = {Pest management science}, volume = {78}, number = {11}, pages = {4709-4718}, doi = {10.1002/ps.7091}, pmid = {35866313}, issn = {1526-4998}, mesh = {Acetates ; Animals ; Anti-Bacterial Agents/pharmacology ; *Aphids ; *Fungicides, Industrial/pharmacology ; Imines ; Nitriles ; Strobilurins/pharmacology ; }, abstract = {BACKGROUND: While several agricultural fungicides are known to directly affect invertebrate pests, including aphids, the mechanisms involved are often unknown. One hypothesis is that fungicides with antibacterial activity suppress bacterial endosymbionts present in aphids which are important for aphid survival. Endosymbiont-related effects are expected to be transgenerational, given that these bacteria are maternally inherited. Here, we test for these associations using three fungicides (chlorothalonil, pyraclostrobin and trifloxystrobin) against the bird cherry-oat aphid, Rhopalosiphum padi, using a microinjected strain that carried both the primary endosymbiont Buchnera and the secondary endosymbiont Rickettsiella.<br><br>RESULTS: We show that the fungicide chlorothalonil did not cause an immediate effect on aphid survival, whereas both strobilurin fungicides (pyraclostrobin and trifloxystrobin) decreased survival after 48&#x2009;h exposure. However, chlorothalonil substantially reduced the lifespan and fecundity of the F1 generation. Trifloxystrobin also reduced the lifespan and fecundity of F1 offspring, however, pyraclostrobin did not affect these traits. None of the fungicides consistently altered the density of Buchnera or Rickettsiella in whole aphids.<br><br>CONCLUSIONS: Our results suggest fungicides have sublethal impacts on R. padi that are not fully realized until the generation after exposure, and these sublethal impacts are not associated with the density of endosymbionts harbored by R. padi. However, we cannot rule out other effects of fungicides on endosymbionts that might influence fitness, like changes in their tissue distribution. We discuss these results within the context of fungicidal effects on aphid suppression across generations and point to potential field applications. &#xa9; 2022 Society of Chemical Industry.}, }
@article {pmid35865927, year = {2022}, author = {Bisschop, K and Kortenbosch, HH and van Eldijk, TJB and Mallon, CA and Salles, JF and Bonte, D and Etienne, RS}, title = {Microbiome Heritability and Its Role in Adaptation of Hosts to Novel Resources.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {703183}, pmid = {35865927}, issn = {1664-302X}, abstract = {Microbiomes are involved in most vital processes, such as immune response, detoxification, and digestion and are thereby elementary to organismal functioning and ultimately the host's fitness. In turn, the microbiome may be influenced by the host and by the host's environment. To understand microbiome dynamics during the process of adaptation to new resources, we performed an evolutionary experiment with the two-spotted spider mite, Tetranychus urticae. We generated genetically depleted strains of the two-spotted spider mite and reared them on their ancestral host plant and two novel host plants for approximately 12 generations. The use of genetically depleted strains reduced the magnitude of genetic adaptation of the spider mite host to the new resource and, hence, allowed for better detection of signals of adaptation via the microbiome. During the course of adaptation, we tested spider mite performance (number of eggs laid and longevity) and characterized the bacterial component of its microbiome (16S rRNA gene sequencing) to determine: (1) whether the bacterial communities were shaped by mite ancestry or plant environment and (2) whether the spider mites' performance and microbiome composition were related. We found that spider mite performance on the novel host plants was clearly correlated with microbiome composition. Because our results show that only little of the total variation in the microbiome can be explained by the properties of the host (spider mite) and the environment (plant species) we studied, we argue that the bacterial community within hosts could be valuable for understanding a species' performance on multiple resources.}, }
@article {pmid35858432, year = {2022}, author = {Masson, F and Rommelaere, S and Schüpfer, F and Boquete, JP and Lemaitre, B}, title = {Disproportionate investment in Spiralin B production limits in-host growth and favors the vertical transmission of Spiroplasma insect endosymbionts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, number = {30}, pages = {e2208461119}, pmid = {35858432}, issn = {1091-6490}, mesh = {Amino Acids/metabolism ; Animals ; *Bacterial Outer Membrane Proteins/metabolism ; *Drosophila melanogaster/microbiology/physiology ; *Host Microbial Interactions ; *Spiroplasma/metabolism ; *Symbiosis ; }, abstract = {Insects frequently harbor endosymbionts, which are bacteria housed within host tissues. These associations are stably maintained over evolutionary timescales through vertical transmission of endosymbionts from host mothers to their offspring. Some endosymbionts manipulate host reproduction to facilitate spread within natural populations. Consequently, such infections have major impacts on insect physiology and evolution. However, technical hurdles have limited our understanding of the molecular mechanisms underlying such insect-endosymbiont interactions. Here, we investigate the nutritional interactions between endosymbiotic partners using the tractable insect Drosophila melanogaster and its natural endosymbiont Spiroplasma poulsonii. Using a combination of functional assays, metabolomics, and proteomics, we show that the abundance and amino acid composition of a single Spiroplasma membrane lectin, Spiralin B (SpiB), dictates the amino acid requirements of the endosymbiont and determines its proliferation within host tissues. Ectopically increasing SpiB levels in host tissues disrupts localization of endosymbionts in the fly egg chambers and decreases vertical transmission. We find that SpiB is likely to be required by the endosymbiont to enter host oocytes, which may explain the massive investment of S. poulsonii in SpiB synthesis. SpiB both permits vertical transmission of the symbiont and limits its growth in nutrient-limiting conditions for the host; therefore, a single protein plays a pivotal role in ensuring durability of the interaction in a variable environment.}, }
@article {pmid35856677, year = {2022}, author = {Kamala Jayanthi, PD and Vyas, M}, title = {Exploring the Transient Microbe Population on Citrus Butterfly Wings.}, journal = {Microbiology spectrum}, volume = {10}, number = {4}, pages = {e0205521}, pmid = {35856677}, issn = {2165-0497}, mesh = {Animals ; *Butterflies/microbiology ; *Citrus ; Humans ; Insecta/microbiology ; Phylogeny ; Wings, Animal/metabolism ; }, abstract = {Microbes carve out dwelling niches in unusual environments. Insects, in general, have been hosts to microbes in different ways. Some insects incorporate microbes as endosymbionts that help with metabolic functions, while some vector pathogenic microbes that cause serious plant and animal diseases, including humans. Microbes isolated from insect sources have been beneficial and a huge information repository. The fascinating and evolutionarily successful insect community has survived mass extinctions as a result of their unique biological traits. Wings have been one of the most important factors contributing to the evolutionary success of insects. In the current study, wings of Papilio polytes, a citrus butterfly, were investigated for the presence of ecologically significant microbes within hours of eclosing under aseptic conditions. Scanning electron microscopy (SEM) revealed the presence of bacteria dwelling in crevices created by a specific arrangement of scales on the butterfly wing. A total of 38 bacterial isolates were obtained from the patched wings of the citrus butterfly, and Bacillus spp. were predominant among them. We probed the occurrence of these microbes to assess their significance to the insect. Many of the isolates displayed antibacterial, antifungal, and biosurfactant properties. Interestingly, one of the isolates displayed entomopathogenic potential toward the notorious agricultural pest mealybug. All the wing isolates were seen to cluster together consistently in a phylogenetic analysis, except for one isolate of Bacillus zhangzhouensis (Papilio polytes isolate [Pp] no. 28), suggesting they are distinct strains. IMPORTANCE This is a first study reporting the presence of culturable microbes on an unusual ecological niche such as butterfly wings. Our findings also establish that microbes inhabit these niches before the butterfly has contact with the environment. The findings in this report have opened up a new area of research which will not only help understand the microbiome of insect wings but might prove beneficial in other specialized studies.}, }
@article {pmid35856258, year = {2022}, author = {Guo, F and Castillo, P and Li, C and Qing, X and Li, H}, title = {Description of Rotylenchus zhongshanensis sp. nov. (Tylenchomorpha: Hoplolaimidae) and discovery of its endosymbiont Cardinium.}, journal = {Journal of helminthology}, volume = {96}, number = {}, pages = {e48}, doi = {10.1017/S0022149X22000384}, pmid = {35856258}, issn = {1475-2697}, mesh = {Animals ; Female ; Genes, Mitochondrial ; Male ; Phylogeny ; RNA, Ribosomal, 16S ; *Rhabditida ; *Tylenchoidea/genetics ; }, abstract = {A new bisexual species of Rotylenchus is described and illustrated based on morphological, morphometric and molecular characterizations. Rotylenchus zhongshanensis sp. nov. is characterized by having a conoid lip region complying with the basic pattern for Hoplolaimidae, but with pharyngeal glands slightly overlapping intestine dorsally and cuticle thickened abnormally in female tail terminus. Females have robust stylet (30.1-33.8 μm). The pharyngeal gland has short dorsal (11.2-16.8 μm) overlap on the intestine. The vulva is located at 48.0-56.5% of body length, and phasmids are pore-like, 4-6 annuli posterior to the anus. For males, phasmids are pore-like, 11-17 annuli posterior to cloaca. The spicules are ventrally arcuate (21.0-28.5 μm) with gubernaculum in 5-8 μm length. The rRNA and mitochondrial COI genes were successfully sequenced from the assembled whole-genome sequences of the new species, and were used for reconstructing the phylogenetic relationships of the new species. A new strain of cyto-endosymbiont Cardinium was also discovered from the genome sequences of R. zhongshanensis sp. nov. The 16S rRNA phylogeny analyses revealed that this new bacterial strain is closed to that from cyst and root-lesion nematodes.}, }
@article {pmid35849008, year = {2022}, author = {Chaves, EB and Nascimento-Pereira, AC and Pinto, JLM and Rodrigues, BL and de Andrade, MS and Rêbelo, JMM}, title = {Detection of Wolbachia in Mosquitoes (Diptera: Culicidae) in the State of Maranhão, Brazil.}, journal = {Journal of medical entomology}, volume = {59}, number = {5}, pages = {1831-1836}, doi = {10.1093/jme/tjac092}, pmid = {35849008}, issn = {1938-2928}, mesh = {*Aedes/microbiology ; Animals ; *Anopheles/microbiology ; Brazil ; *Culex/microbiology ; *Culicidae/microbiology ; *Wolbachia ; }, abstract = {Recently, the endobacteria Wolbachia has emerged as a biological tool for the control of arboviruses. Thus, we investigated the rate of natural infection by Wolbachia in Culicidae species from Maranhão, Brazil. For this, we amplified the Wolbachia surface protein gene (wsp) from mosquitoes collected in six localities of Maranhão, and positive samples were subjected to new analysis using group-specific primers. In total, 448 specimens comprising 6 genera and 18 species of mosquitoes were analyzed. Wolbachia DNA was PCR-detected in 7 species, three of which are new records: Aedes scapularis (Rondani, 1848), Coquillettidia juxtamansonia (Chagas, 1907) and Cq. venezuelensis (Theobald, 1912), in addition to Ae. albopictus (Skuse, 1894) and Culex quinquefasciatus Say, 1823, which are commonly described as permissive to maintain this bacterium in natural environments, and two species of the subgenera Anopheles (Nyssorhynchus) Blanchard, 1902 and Culex (Melanoconion) Theobald, 1903 which could not be identified at species level. The infection rate of all species ranged from 0 to 80%, and the average value was 16.5%. This study increases the knowledge about the prevalence of Wolbachia in the culicid fauna and may help in selecting strains for biological control purposes.}, }
@article {pmid35841879, year = {2022}, author = {Gonçalves, P and Gonçalves, C}, title = {Horizontal gene transfer in yeasts.}, journal = {Current opinion in genetics &amp; development}, volume = {76}, number = {}, pages = {101950}, doi = {10.1016/j.gde.2022.101950}, pmid = {35841879}, issn = {1879-0380}, mesh = {*Bacteria/genetics ; *Gene Transfer, Horizontal/genetics ; Phylogeny ; }, abstract = {Horizontal gene transfer (HGT), defined as the exchange of genetic material other than from parent to progeny, is very common in bacteria and appears to constitute the most important mechanism contributing to enlarge a species gene pool. However, in eukaryotes, HGT is certainly much less common and some early insufficiently consubstantiated cases involving bacterial donors led some to consider that it was unlikely to occur in eukaryotes outside the host/endosymbiont relationship. More recently, plenty of reports of interdomain HGT have seen the light based on the strictest criteria, many concerning filamentous fungi and yeasts. Here, we attempt to summarize the most prominent instances of HGT reported in yeasts as well as what we have been able to learn so far concerning frequency and distribution, mechanisms, barriers, function of horizontally acquired genes, and the role of HGT in domestication.}, }
@article {pmid35841431, year = {2022}, author = {Mitra, A and Acharya, K and Bhattacharya, A}, title = {Evolutionary analysis of globin domains from kinetoplastids.}, journal = {Archives of microbiology}, volume = {204}, number = {8}, pages = {493}, pmid = {35841431}, issn = {1432-072X}, mesh = {Amino Acid Sequence ; Codon ; *Gene Transfer, Horizontal ; *Globins/chemistry/genetics/metabolism ; Heme/chemistry/metabolism ; Phylogeny ; }, abstract = {Globin (Gb) domains function in sensing gaseous ligands like oxygen and nitric oxide. In recent years, Gb domain containing heme binding adenylate cyclases (OsAC or GbAC) emerged as significant modulator of Leishmania response to hypoxia and oxidative stress. During progression of life cycle stages, kinetoplastids experience altered condition in insect vectors or other hosts. Moreover, marked diversity in life style has been accounted among kinetoplastids. Distribution and abundance of Gb-domains vary between different groups of kinetoplastids. While in bodonoids, Gbs are not combined with any other functional domains, in trypanosomatids it is either fused with adenylate cyclase (AC) or oxidoreductase (OxR) domains. In salivarian trypanosomatids and Leishmania (Viannia) subtypes, no gene product featuring Gbs can be identified. In this context, evolution of Gb-domains in kinetoplastids was explored. GbOxR derived Gbs clustered with bacterial flavohemoglobins (fHb) including one fHb from Advenella, an endosymbiont of monoxeneous trypanosomatids. Codon adaptation and other evolutionary analysis suggested that OsAC (LmjF.28.0090), the solitary Gb-domain featuring gene product in Leishmania, was acquired via possible horizontal gene transfer. Substantial functional divergence was estimated between orthologues of genes encoding GbAC or GbOxR; an observation also reflected in structural alignment and heme-binding residue predictions. Orthologue-paralogue and synteny analysis indicated genomic reduction in GbOxR and GbAC loci for dixeneous trypanosomatids.}, }
@article {pmid35840731, year = {2022}, author = {Cárdenas, A and Raina, JB and Pogoreutz, C and Rädecker, N and Bougoure, J and Guagliardo, P and Pernice, M and Voolstra, CR}, title = {Greater functional diversity and redundancy of coral endolithic microbiomes align with lower coral bleaching susceptibility.}, journal = {The ISME journal}, volume = {16}, number = {10}, pages = {2406-2420}, pmid = {35840731}, issn = {1751-7370}, mesh = {Animals ; *Anthozoa ; Coral Bleaching ; Coral Reefs ; Metagenomics ; *Microbiota ; Symbiosis ; }, abstract = {The skeleton of reef-building coral harbors diverse microbial communities that could compensate for metabolic deficiencies caused by the loss of algal endosymbionts, i.e., coral bleaching. However, it is unknown to what extent endolith taxonomic diversity and functional potential might contribute to thermal resilience. Here we exposed Goniastrea edwardsi and Porites lutea, two common reef-building corals from the central Red Sea to a 17-day long heat stress. Using hyperspectral imaging, marker gene/metagenomic sequencing, and NanoSIMS, we characterized their endolithic microbiomes together with [15]N and [13]C assimilation of two skeletal compartments: the endolithic band directly below the coral tissue and the deep skeleton. The bleaching-resistant G. edwardsi was associated with endolithic microbiomes of greater functional diversity and redundancy that exhibited lower N and C assimilation than endoliths in the bleaching-sensitive P. lutea. We propose that the lower endolithic primary productivity in G. edwardsi can be attributed to the dominance of chemolithotrophs. Lower primary production within the skeleton may prevent unbalanced nutrient fluxes to coral tissues under heat stress, thereby preserving nutrient-limiting conditions characteristic of a stable coral-algal symbiosis. Our findings link coral endolithic microbiome structure and function to bleaching susceptibility, providing new avenues for understanding and eventually mitigating reef loss.}, }
@article {pmid35839761, year = {2022}, author = {Boscaro, V and Syberg-Olsen, MJ and Irwin, NAT and George, EE and Vannini, C and Husnik, F and Keeling, PJ}, title = {All essential endosymbionts of the ciliate Euplotes are cyclically replaced.}, journal = {Current biology : CB}, volume = {32}, number = {15}, pages = {R826-R827}, doi = {10.1016/j.cub.2022.06.052}, pmid = {35839761}, issn = {1879-0445}, mesh = {Animals ; Bacteria ; Biological Evolution ; *Ciliophora ; *Euplotes/microbiology ; Insecta ; Phylogeny ; Symbiosis ; }, abstract = {Symbiotic systems vary in the degree to which the partners are bound to each other[1]. At one extreme, there are intracellular endosymbionts in mutually obligate relationships with their host, often interpreted as mutualistic. The symbiosis between the betaproteobacterium Polynucleobacter and the ciliate Euplotes (clade B) challenges this view[2]: although freshwater Euplotes species long ago became dependent on endosymbionts, the many extant Polynucleobacter lineages they harbour arose recently and in parallel from different free-living ancestors[2]. The host requires the endosymbionts for reproduction and survival[3], but each newly established symbiont is ultimately driven to extinction in a cycle of establishment, degeneration, and replacement. Similar replacement events have been observed in sap-feeding insects[4-6], a model for bacteria-eukaryote symbioses[7], but usually only affect a small subset of the host populations. Most insects retain an ancient coevolving symbiont, suggesting that long-term mutualism and permanent integration remain the rule and symbiont turnovers are mere evolutionary side-stories. Here we show that this is not the case for Euplotes. We examined all known essential Euplotes symbionts and found that none are ancient or coevolving; rather, all are recently established and continuously replaced over relatively short evolutionary time spans, making the symbiosis ancient for the host but not for any bacterial lineage.}, }
@article {pmid35829939, year = {2022}, author = {Carvajal-Agudelo, JD and Ramírez-Chaves, HE and Ossa-López, PA and Rivera-Páez, FA}, title = {Bacteria related to tick-borne pathogen assemblages in Ornithodoros cf. hasei (Acari: Argasidae) and blood of the wild mammal hosts in the Orinoquia region, Colombia.}, journal = {Experimental &amp; applied acarology}, volume = {87}, number = {2-3}, pages = {253-271}, pmid = {35829939}, issn = {1572-9702}, mesh = {*Acari ; Animals ; *Argasidae ; *Chiroptera ; Colombia ; *Ornithodoros ; RNA, Ribosomal, 16S ; *Rickettsia ; }, abstract = {Interest in research on soft ticks has increased in recent decades, leading to valuable insight into their role as disease vectors. The use of metagenomics-based analyses have helped to elucidate ecological factors involved in pathogen, vector, and host dynamics. To understand the main bacterial assemblages present in Ornithodoros cf. hasei and its mammalian hosts, 84 ticks and 13 blood samples from bat hosts (Chiroptera) were selected, and the 16S rRNA gene V4 region was sequenced in five pools (each one related to each host-tick pairing). Bacterial taxonomic assignment analyses were performed by comparing operational taxonomic units (OTUs) shared between ticks and their host blood. This analysis showed the presence of Proteobacteria (38.8%), Enterobacteriaceae (25%), Firmicutes (12.3%), and Actinobacteria (10.9%) within blood samples, and Rickettsiaceae (39%), Firmicutes (25%), Actinobacteria (13.1%), and Proteobacteria (9%) within ticks. Species related to potentially pathogenic genera were detected in ticks, such as Borrelia sp., Bartonella tamiae, Ehrlichia sp. and Rickettsia-like endosymbiont, and the presence of these organisms was found in all analyzed bat species (Cynomops planirostris, Molossus pretiosus, Noctilio albiventris), and O. cf. hasei. About 41-48.6% of bacterial OTUs (genera and species) were shared between ticks and the blood of bat hosts. Targeted metagenomic screening techniques allowed the detection of tick-associated pathogens for O. cf. hasei and small mammals for the first time, enabling future research on many of these pathogens.}, }
@article {pmid35814684, year = {2022}, author = {Barman, M and Samanta, S and Upadhyaya, G and Thakur, H and Chakraborty, S and Samanta, A and Tarafdar, J}, title = {Unraveling the Basis of Neonicotinoid Resistance in Whitefly Species Complex: Role of Endosymbiotic Bacteria and Insecticide Resistance Genes.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {901793}, pmid = {35814684}, issn = {1664-302X}, abstract = {Bemisia tabaci (whitefly) is one of the most detrimental agricultural insect pests and vectors of many plant viruses distributed worldwide. Knowledge of the distribution patterns and insecticide resistance of this cryptic species is crucial for its management. In this study, genetic variation of mitochondrial cytochrome oxidase subunit 1 (MtCoI) gene of B. tabaci was analyzed followed by a study of the infection profile of various endosymbionts in 26 whitefly populations collected from West Bengal, India. Phylogenetic analysis revealed Asia I as the major cryptic species (65.38%), followed by Asia II 5, China 3, and Asia II 7, which were diversified into 20 different haplotypes. In addition to the primary endosymbiont (C. poriera), each of the four whitefly species showed a variable population of three secondary endosymbionts, majorly Arsenophonus with the highest infection rate (73.07%), followed by Wolbachia and Rickettsia. Further phylogenetic analyses revealed the presence of two subgroups of Arsenophonus, viz., A1 and A2, and one each in Wolbachia (W1) and Rickettsia (R3). Resistance to thiamethoxam, imidacloprid, and acetamiprid insecticides was analyzed for a clear picture of pesticide resistance status. The highest susceptibility was noted toward thiamethoxam (LC50 = 5.36 mg/L), followed by imidacloprid and acetamiprid. The whitefly population from Purulia and Hooghly districts bearing Asia II 7 and Asia II 5 cryptic species, respectively, shows maximum resistance. The differences in mean relative titer of four symbiotic bacteria among field populations varied considerably; however, a significant positive linear correlation was observed between the resistance level and relative titer of Arsenophonus and Wolbachia in the case of imidacloprid and thiamethoxam, while only Wolbachia was found in case of acetamiprid. Expression analysis demonstrated differential upregulation of insecticide resistance genes with Purulia and Hooghly populations showing maximally upregulated P450 genes. Moreover, thiamethoxam and imidacloprid resistance ratio (RR) showed a significant correlation with CYP6CM1, CYP6DZ7, and CYP4C64 genes, while acetamiprid RR correlated with CYP6CX1, CYP6DW2, CYP6DZ7, and CYP4C64 genes. Taken together, these findings suggested that P450 mono-oxygenase and symbiotic bacteria together affected whitefly resistance to neonicotinoids. Hence, a symbiont-oriented management programme could be a better alternative to control or delay resistance development in whitefly and can be used for pesticide clean-up in an agricultural field.}, }
@article {pmid35799468, year = {2022}, author = {Horas, EL and Metzger, SM and Platzer, B and Kelly, JB and Becks, L}, title = {Context-dependent costs and benefits of endosymbiotic interactions in a ciliate-algae system.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16112}, pmid = {35799468}, issn = {1462-2920}, abstract = {Endosymbiosis, an interaction between two species where one lives within the other, has evolved multiple times independently, but the underlying mechanisms remain unclear. Evolutionary theory suggests that for an endosymbiotic interaction to remain stable over time, births of both partners should be higher than their deaths in symbiosis and deaths of both partners should be higher than their births when living independently. However, experimentally measuring this can be difficult and conclusions tend to focus on the host. Using a ciliate-algal system (Paramecium bursaria host and Chlorella endosymbionts), we estimated the benefits and costs of endosymbiosis for both organisms using fitness measurements in different biotic environments to test under which environmental conditions the net effects of the interaction were positive for both partners. We found that the net effects of harbouring endosymbionts were positive for the ciliate hosts as it allowed them to survive in conditions of low-quality bacteria food. The algae benefitted by being endosymbiotic when predators such as the hosts were present, but the net effects were dependent on the total density of hosts, decreasing as hosts densities increased. Overall, we show that including context-dependency of endosymbiosis is essential in understanding how these interactions have evolved.}, }
@article {pmid35798888, year = {2022}, author = {Schön, ME and Martijn, J and Vosseberg, J and Köstlbacher, S and Ettema, TJG}, title = {The evolutionary origin of host association in the Rickettsiales.}, journal = {Nature microbiology}, volume = {7}, number = {8}, pages = {1189-1199}, pmid = {35798888}, issn = {2058-5276}, support = {817834/ERC_/European Research Council/International ; }, mesh = {Humans ; *Metagenome ; Phylogeny ; *Rickettsiales/genetics ; }, abstract = {The evolution of obligate host-association of bacterial symbionts and pathogens remains poorly understood. The Rickettsiales are an alphaproteobacterial order of obligate endosymbionts and parasites that infect a wide variety of eukaryotic hosts, including humans, livestock, insects and protists. Induced by their host-associated lifestyle, Rickettsiales genomes have undergone reductive evolution, leading to small, AT-rich genomes with limited metabolic capacities. Here we uncover eleven deep-branching alphaproteobacterial metagenome assembled genomes from aquatic environments, including data from the Tara Oceans initiative and other publicly available datasets, distributed over three previously undescribed Rickettsiales-related clades. Phylogenomic analyses reveal that two of these clades, Mitibacteraceae and Athabascaceae, branch sister to all previously sampled Rickettsiales. The third clade, Gamibacteraceae, branch sister to the recently identified ectosymbiotic 'Candidatus Deianiraea vastatrix'. Comparative analyses indicate that the gene complement of Mitibacteraceae and Athabascaceae is reminiscent of that of free-living and biofilm-associated bacteria. Ancestral genome content reconstruction across the Rickettsiales species tree further suggests that the evolution of host association in Rickettsiales was a gradual process that may have involved the repurposing of a type IV secretion system.}, }
@article {pmid35795355, year = {2022}, author = {Manthey, JD and Girón, JC and Hruska, JP}, title = {Impact of host demography and evolutionary history on endosymbiont molecular evolution: A test in carpenter ants (genus Camponotus) and their Blochmannia endosymbionts.}, journal = {Ecology and evolution}, volume = {12}, number = {7}, pages = {e9026}, pmid = {35795355}, issn = {2045-7758}, abstract = {Obligate endosymbioses are tight associations between symbionts and the hosts they live inside. Hosts and their associated obligate endosymbionts generally exhibit codiversification, which has been documented in taxonomically diverse insect lineages. Host demography (e.g., effective population sizes) may impact the demography of endosymbionts, which may lead to an association between host demography and the patterns and processes of endosymbiont molecular evolution. Here, we used whole-genome sequencing data for carpenter ants (Genus Camponotus; subgenera Camponotus and Tanaemyrmex) and their Blochmannia endosymbionts as our study system to address whether Camponotus demography shapes Blochmannia molecular evolution. Using whole-genome phylogenomics, we confirmed previous work identifying codiversification between carpenter ants and their Blochmannia endosymbionts. We found that Blochmannia genes have evolved at a pace ~30× faster than that of their hosts' molecular evolution and that these rates are positively associated with host rates of molecular evolution. Using multiple tests for selection in Blochmannia genes, we found signatures of positive selection and shifts in selection strength across the phylogeny. Host demography was associated with Blochmannia shifts toward increased selection strengths, but not associated with Blochmannia selection relaxation, positive selection, genetic drift rates, or genome size evolution. Mixed support for relationships between host effective population sizes and Blochmannia molecular evolution suggests weak or uncoupled relationships between host demography and Blochmannia population genomic processes. Finally, we found that Blochmannia genome size evolution was associated with genome-wide estimates of genetic drift and number of genes with relaxed selection pressures.}, }
@article {pmid35792339, year = {2022}, author = {Mohamed, SA and Dubois, T and Azrag, AG and Ndlela, S and Neuenschwander, P}, title = {Classical biological of key horticultural pests in Africa: successes, challenges, and opportunities.}, journal = {Current opinion in insect science}, volume = {53}, number = {}, pages = {100945}, doi = {10.1016/j.cois.2022.100945}, pmid = {35792339}, issn = {2214-5753}, mesh = {Africa ; Animals ; *Insecta ; *Introduced Species ; }, abstract = {Classical biological control (CBC) is considered a safer and more sustainable alternative for management of alien-invasive species. This review presents recent advances in CBC of key horticultural insect pests using parasitoids in Africa. Several CBC programs have been undertaken targeting different insect pests of both fruits and vegetables, largely yielding outstanding success. Key obstacles impeding CBC and opportunities that could promote CBC in Africa are outlined. Also, very brief highlights on recent scientific and technological advances in modeling, integrative taxonomy and molecular tools, and endosymbionts that relate to CBC are provided.}, }
@article {pmid35765190, year = {2022}, author = {Weiland, SO and Detcharoen, M and Schlick-Steiner, BC and Steiner, FM}, title = {Analyses of locomotion, wing morphology, and microbiome in Drosophila nigrosparsa after recovery from antibiotics.}, journal = {MicrobiologyOpen}, volume = {11}, number = {3}, pages = {e1291}, pmid = {35765190}, issn = {2045-8827}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Drosophila ; Locomotion ; *Microbiota ; Tetracycline/pharmacology ; *Wolbachia/genetics ; }, abstract = {Antibiotics, such as tetracycline, have been frequently used to cure arthropods of Wolbachia endosymbionts. After the symbionts have been removed, the hosts must recover for some generations from the side effects of the antibiotics. However, most studies do not assess the direct and indirect longer-term effects of antibiotics used to remove Wolbachia, which may question the exact contribution of this endosymbiont to the effects observed. Here, we used the fly Drosophila nigrosparsa treated or not with tetracycline for three generations followed by two generations of recovery to investigate the effects of this antibiotic on the fly locomotion, wing morphology, and the gut microbiome. We found that antibiotic treatment did not affect fly locomotion two generations after being treated with the antibiotic. In addition, gut-microbiome restoration was tested as a more efficient solution to reduce the potential side effects of tetracycline on the microbiome. There was no significant difference in alpha diversity between gut restoration and other treatments, but the abundance of some bacterial taxa differed significantly between the gut-restoration treatment and the control. We conclude that in D. nigrosparsa the recovery period of two generations after being treated with the antibiotic is sufficient for locomotion, and suggest a general assessment of direct and indirect effects of antibiotics after a particular recovery time.}, }
@article {pmid35755814, year = {2022}, author = {Lima, RM and Rathod, BB and Tiricz, H and Howan, DHO and Al Bouni, MA and Jenei, S and Tímár, E and Endre, G and Tóth, GK and Kondorosi, &#xc9;}, title = {Legume Plant Peptides as Sources of Novel Antimicrobial Molecules Against Human Pathogens.}, journal = {Frontiers in molecular biosciences}, volume = {9}, number = {}, pages = {870460}, pmid = {35755814}, issn = {2296-889X}, abstract = {Antimicrobial peptides are prominent components of the plant immune system acting against a wide variety of pathogens. Legume plants from the inverted repeat lacking clade (IRLC) have evolved a unique gene family encoding nodule-specific cysteine-rich NCR peptides acting in the symbiotic cells of root nodules, where they convert their bacterial endosymbionts into non-cultivable, polyploid nitrogen-fixing cells. NCRs are usually 30-50 amino acids long peptides having a characteristic pattern of 4 or 6 cysteines and highly divergent amino acid composition. While the function of NCRs is largely unknown, antimicrobial activity has been demonstrated for a few cationic Medicago truncatula NCR peptides against bacterial and fungal pathogens. The advantages of these plant peptides are their broad antimicrobial spectrum, fast killing modes of actions, multiple bacterial targets, and low propensity to develop resistance to them and no or low cytotoxicity to human cells. In the IRLC legumes, the number of NCR genes varies from a few to several hundred and it is possible that altogether hundreds of thousands of different NCR peptides exist. Due to the need for new antimicrobial agents, we investigated the antimicrobial potential of 104 synthetic NCR peptides from M. truncatula, M. sativa, Pisum sativum, Galega orientalis and Cicer arietinum against eight human pathogens, including ESKAPE bacteria. 50 NCRs showed antimicrobial activity with differences in the antimicrobial spectrum and effectivity. The most active peptides eliminated bacteria at concentrations from 0.8 to 3.1 μM. High isoelectric point and positive net charge were important but not the only determinants of their antimicrobial activity. Testing the activity of shorter peptide derivatives against Acinetobacter baumannii and Candida albicans led to identification of regions responsible for the antimicrobial activity and provided insight into their potential modes of action. This work provides highly potent lead molecules without hemolytic activity on human blood cells for novel antimicrobial drugs to fight against pathogens.}, }
@article {pmid35745515, year = {2022}, author = {Karsenti, N and Purssell, A and Lau, R and Ralevski, F and Bhasker, S and Raheel, H and Boggild, AK}, title = {Surveillance of Amoebic Keratitis-Causing Acanthamoebae for Potential Bacterial Endosymbionts in Ontario, Canada.}, journal = {Pathogens (Basel, Switzerland)}, volume = {11}, number = {6}, pages = {}, pmid = {35745515}, issn = {2076-0817}, abstract = {Acanthamoeba spp. are the causative pathogens of several infections, including amoebic keratitis (AK), a vision-threatening infection. Acanthamoebae from corneal specimens of patients with AK harbor bacterial endosymbionts, which may increase virulence. We sought to understand the spectrum of bacterial endosymbionts present in clinical isolates of Acanthamoeba spp. identified in our reference parasitology laboratory. Isolates of Acanthamoeba spp. obtained from our biobank of anonymized corneal scrapings were screened for potential endosymbionts by PCR using primer pairs detecting bacteria belonging to orders Chlamydiales, Rickettsiales, or Legionellales and pan16S primers. Three primer pairs specific to the 18s rRNA gene of Acanthamoeba spp. were used for the amplification of Acanthamoeba DNA used for sequencing. Sanger sequencing of all PCR products was performed, followed by BLAST analysis for species identification. We screened 26 clinical isolates of Acanthamoeba spp. for potential endosymbionts. Five isolates (19%) were found to contain bacterial DNA belonging to Legionellales. Three (11%) contained members of the Rickettsiales and Pseudomonas genticulata was detected in a Rickettsia-positive sample. One strain (4%) contained Neochlamydia hartmannellae, a member of the Chlamydiales order. Bacterial endosymbionts are prevalent in clinical strains of Acanthamoeba causing AK isolated from corneal scrapings. The demonstration of these organisms in clinical Acanthamoeba isolates supports a potential exploration of anti-endosymbiont therapeutics as an adjuvant therapy in the treatment of AK.}, }
@article {pmid35744766, year = {2022}, author = {Takahashi, T}, title = {Method for Stress Assessment of Endosymbiotic Algae in Paramecium bursaria as a Model System for Endosymbiosis.}, journal = {Microorganisms}, volume = {10}, number = {6}, pages = {}, pmid = {35744766}, issn = {2076-2607}, abstract = {Endosymbiosis between heterotrophic host and microalga often breaks down because of environmental conditions, such as temperature change and exposure to toxic substances. By the time of the apparent breakdown of endosymbiosis, it is often too late for the endosymbiotic system to recover. In this study, I developed a technique for the stress assessment of endosymbiotic algae using Paramecium bursaria as an endosymbiosis model, after treatment with the herbicide paraquat, an endosymbiotic collapse inducer. Microcapillary flow cytometry was employed to evaluate a large number of cells in an approach that is more rapid than microscopy evaluation. In the assay, red fluorescence of the chlorophyll reflected the number of endosymbionts within the host cell, while yellow fluorescence fluctuated in response to the deteriorating viability of the endosymbiont under stress. Hence, the yellow/red fluorescence intensity ratio can be used as an algal stress index independent of the algal number. An optical evaluation revealed that the viability of the endosymbiotic algae within the host cell decreased after treatment with paraquat and that the remaining endosymbionts were exposed to high stress. The devised assay is a potential environmental monitoring method, applicable not only to P. bursaria but also to multicellular symbiotic units, such as corals.}, }
@article {pmid35740880, year = {2022}, author = {Hassan, K and Chepkirui, C and Llanos-López, NA and Matasyoh, JC and Decock, C and Marin-Felix, Y and Stadler, M}, title = {Meroterpenoids Possibly Produced by a Bacterial Endosymbiont of the Tropical Basidiomycete Echinochaete brachypora.}, journal = {Biomolecules}, volume = {12}, number = {6}, pages = {}, pmid = {35740880}, issn = {2218-273X}, mesh = {Anti-Bacterial Agents/chemistry ; Bacteria/metabolism ; *Basidiomycota/chemistry ; Fungi/metabolism ; *Polyporaceae/metabolism ; }, abstract = {A mycelial culture of the African basidiomycete Echinochaete cf. brachypora was studied for biologically active secondary metabolites, and four compounds were isolated from its crude extract derived from shake flask fermentations, using preparative high-performance liquid chromatography (HPLC). The pure metabolites were identified using extensive nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HR-MS). Aside from the new metabolites 1-methoxyneomarinone (1) and (E)-3-methyl-5-(-12,13,14-trimethylcyclohex-10-en-6-yl)pent-2-enoic acid (4), the known metabolites neomarinone (2) and fumaquinone (4) were obtained. Such compounds had previously only been reported from Actinobacteria but were never isolated from the cultures of a fungus. This observation prompted us to evaluate whether the above metabolites may actually have been produced by an endosymbiontic bacterium that is associated with the basidiomycete. We have indeed been able to characterize bacterial 16S rDNA in the fungal mycelia, and the production of the metabolites stopped when the fungus was sub-cultured on a medium containing antibacterial antibiotics. Therefore, we have found strong evidence that compounds 1-4 are not of fungal origin. However, the endofungal bacterium was shown to belong to the genus Ralstonia, which has never been reported to produce similar metabolites to 1-4. Moreover, we failed to obtain the bacterial strain in pure culture to provide final proof for its identity. In any case, the current report is the first to document that polyporoid Basidiomycota are associated with endosymbionts and constitutes the first report on secondary metabolites from the genus Echinochaete.}, }
@article {pmid35738252, year = {2022}, author = {George, EE and Tashyreva, D and Kwong, WK and Okamoto, N and Horák, A and Husnik, F and Lukeš, J and Keeling, PJ}, title = {Gene Transfer Agents in Bacterial Endosymbionts of Microbial Eukaryotes.}, journal = {Genome biology and evolution}, volume = {14}, number = {7}, pages = {}, pmid = {35738252}, issn = {1759-6653}, mesh = {Bacteria/genetics ; *Eukaryota/genetics ; Gene Transfer, Horizontal ; Phylogeny ; Symbiosis/genetics ; *Viruses ; }, abstract = {Gene transfer agents (GTAs) are virus-like structures that package and transfer prokaryotic DNA from donor to recipient prokaryotic cells. Here, we describe widespread GTA gene clusters in the highly reduced genomes of bacterial endosymbionts from microbial eukaryotes (protists). Homologs of the GTA capsid and portal complexes were initially found to be present in several highly reduced alphaproteobacterial endosymbionts of diplonemid protists (Rickettsiales and Rhodospirillales). Evidence of GTA expression was found in polyA-enriched metatranscriptomes of the diplonemid hosts and their endosymbionts, but due to biases in the polyA-enrichment methods, levels of GTA expression could not be determined. Examining the genomes of closely related bacteria revealed that the pattern of retained GTA head/capsid complexes with missing tail components was common across Rickettsiales and Holosporaceae (Rhodospirillales), all obligate symbionts with a wide variety of eukaryotic hosts. A dN/dS analysis of Rickettsiales and Holosporaceae symbionts revealed that purifying selection is likely the main driver of GTA evolution in symbionts, suggesting they remain functional, but the ecological function of GTAs in bacterial symbionts is unknown. In particular, it is unclear how increasing horizontal gene transfer in small, largely clonal endosymbiont populations can explain GTA retention, and, therefore, the structures may have been repurposed in endosymbionts for host interactions. Either way, their widespread retention and conservation in endosymbionts of diverse eukaryotes suggests an important role in symbiosis.}, }
@article {pmid35735896, year = {2022}, author = {Nian, X and Tao, X and Xiao, Z and Wang, D and He, Y}, title = {Effects of Sublethal Concentrations of Tetracycline Hydrochloride on the Biological Characteristics and Wolbachia Titer in Parthenogenesis Trichogramma pretiosum.}, journal = {Insects}, volume = {13}, number = {6}, pages = {}, pmid = {35735896}, issn = {2075-4450}, abstract = {Trichogramma pretiosum Riley is an important natural enemy and biological control agent of lepidopteran pests. Wolbachia is an intracellular endosymbiont that induces parthenogenesis in the parasitoid T. pretiosum. In this paper, the sublethal effects of the antibiotic tetracycline hydrochloride on the development and reproduction of T. pretiosum were studied. Emerged females were fed with sublethal concentrations (LC5, LC15, and LC35) of tetracycline for ten generations. The biological parameters (longevity, parasitized eggs, and fecundity) of treated females significantly reduced compared with the control Moreover, the percentage of female offspring in the treatments significantly reduced, but the percentage of male offspring significantly increased. In addition, the Wolbachia titer sharply reduced after two generations of antibiotic treatments, but it could still be detected even after ten successive generations of antibiotic treatments, which indicated that Wolbachia was not completely removed by sublethal concentrations of tetracycline. The control lines with higher Wolbachia titers produced more female offspring than the tetracycline treatments with lower Wolbachia titers, indicating that the Wolbachia titer affected the sex determination of T. pretiosum. Our results show that sublethal concentrations of tetracycline had adverse effects on the development of T. pretiosum, and Wolbachia titers affected the sexual development of T. pretiosum eggs.}, }
@article {pmid35731940, year = {2022}, author = {Romero Picazo, D and Werner, A and Dagan, T and Kupczok, A}, title = {Pangenome Evolution in Environmentally Transmitted Symbionts of Deep-Sea Mussels Is Governed by Vertical Inheritance.}, journal = {Genome biology and evolution}, volume = {14}, number = {7}, pages = {}, pmid = {35731940}, issn = {1759-6653}, mesh = {Animals ; Bacteria/genetics ; Gene Transfer, Horizontal ; Genome, Bacterial ; Methane ; *Mytilidae/genetics/microbiology ; Phylogeny ; Sulfur ; Symbiosis/genetics ; }, abstract = {Microbial pangenomes vary across species; their size and structure are determined by genetic diversity within the population and by gene loss and horizontal gene transfer (HGT). Many bacteria are associated with eukaryotic hosts where the host colonization dynamics may impact bacterial genome evolution. Host-associated lifestyle has been recognized as a barrier to HGT in parentally transmitted bacteria. However, pangenome evolution of environmentally acquired symbionts remains understudied, often due to limitations in symbiont cultivation. Using high-resolution metagenomics, here we study pangenome evolution of two co-occurring endosymbionts inhabiting Bathymodiolus brooksi mussels from a single cold seep. The symbionts, sulfur-oxidizing (SOX) and methane-oxidizing (MOX) gamma-proteobacteria, are environmentally acquired at an early developmental stage and individual mussels may harbor multiple strains of each symbiont species. We found differences in the accessory gene content of both symbionts across individual mussels, which are reflected by differences in symbiont strain composition. Compared with core genes, accessory genes are enriched in genome plasticity functions. We found no evidence for recent HGT between both symbionts. A comparison between the symbiont pangenomes revealed that the MOX population is less diverged and contains fewer accessory genes, supporting that the MOX association with B. brooksi is more recent in comparison to that of SOX. Our results show that the pangenomes of both symbionts evolved mainly by vertical inheritance. We conclude that genome evolution of environmentally transmitted symbionts that associate with individual hosts over their lifetime is affected by a narrow symbiosis where the frequency of HGT is constrained.}, }
@article {pmid35726500, year = {2022}, author = {Dzul-Rosado, K and Maldonado-Borges, JI and Puerto-Manzano, FI and Lammoglia-Villagómez, MA and Becker, I and Sánchez-Montes, S}, title = {First exploratory study of bacterial pathogens and endosymbionts in head lice from a Mayan community in southern Mexico.}, journal = {Zoonoses and public health}, volume = {69}, number = {6}, pages = {729-736}, doi = {10.1111/zph.12982}, pmid = {35726500}, issn = {1863-2378}, mesh = {*Acinetobacter/genetics ; Animals ; Bacteria/genetics ; DNA ; Humans ; *Lice Infestations/epidemiology/veterinary ; Mexico/epidemiology ; *Pediculus/genetics/microbiology ; Phylogeny ; }, abstract = {Lice represent one of the most neglected group of vectors worldwide, particularly in Latin America. Records of bacterial agents related to head lice are non-existent in this region of the continent. Many of these communities often do not have adequate access to public services and/or health protection. The normalization of this condition prevents them from manifesting discomfort, such as bites and itching, which further aggravates the situation, as they can be vectors of important diseases. For this reason, the aim of this work was to identify the richness of bacterial pathogens (Acinetobacter, Bartonella, and Rickettsia) and endosymbionts (Wolbachia) in head lice of paediatric patients from the indigenous municipality of Hoctun, Yucatan, Mexico. DNA extraction was performed using the QIAamp DNA Mini Kit. For the detection of bacterial pathogens, fragments of the gltA, rpoB, and 16S rDNA genes were amplified. For the detection of Wolbachia, the wsp gene was amplified. Of the 28 lice analysed, the presence of two genera of bacterial pathogens was detected Acinetobacter (42.9% = 12/28) and Bartonella (7.14% = 2/28). We also detected the endosymbiont Wolbachia (71.42% = 20/28). Our results showed that DNA from three bacteria species (Acinetobacter baumannii, Bartonella quintana, and Wolbachia pipientis) was present with frequencies ranging from 3.57% to 71.42%. This work represents the first exploratory study of the diversity of agents associated with head lice (Pediculus humanus capitis) in Mexico and Latin America. Due to the findings generated in the present study, it is important to perform surveillance of head lice populations to identify the degree of spread of these pathogens and their impact on populations in the region.}, }
@article {pmid35723456, year = {2022}, author = {Chen, L and Xiao, Q and Shi, M and Cheng, J and Wu, J}, title = {Detecting Wolbachia Strain wAlbB in Aedes albopictus Cell Lines.}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {184}, pages = {}, doi = {10.3791/63662}, pmid = {35723456}, issn = {1940-087X}, mesh = {*Aedes ; Animals ; Cell Line ; Mosquito Vectors ; *RNA Viruses ; *Wolbachia/physiology ; }, abstract = {As a maternally harbored endosymbiont, Wolbachia infects large proportions of insect populations. Studies have recently reported the successful regulation of RNA virus transmission using Wolbachia-transfected mosquitoes. Key strategies to control viruses include the manipulation of host reproduction via cytoplasmic incompatibility and the inhibition of viral transcripts via immune priming and competition for host-derived resources. However, the underlying mechanisms of the responses of Wolbachia-transfected mosquitoes to viral infection are poorly understood. This paper presents a protocol for the in vitro identification of Wolbachia infection at the nucleic acid and protein levels in Aedes albopictus (Diptera: Culicidae) Aa23 cells to enhance the understanding of the interactions between Wolbachia and its insect vectors. Through the combined use of polymerase chain reaction (PCR), quantitative PCR, western blot, and immunological analytical methods, a standard morphologic protocol has been described for the detection of Wolbachia-infected cells that is more accurate than the use of a single method. This approach may also be applied to the detection of Wolbachia infection in other insect taxa.}, }
@article {pmid35716742, year = {2022}, author = {Perrotta, BG and Kidd, KA and Walters, DM}, title = {PCB exposure is associated with reduction of endosymbionts in riparian spider microbiomes.}, journal = {The Science of the total environment}, volume = {842}, number = {}, pages = {156726}, doi = {10.1016/j.scitotenv.2022.156726}, pmid = {35716742}, issn = {1879-1026}, mesh = {Animals ; Insecta ; *Microbiota ; Ontario ; *Polychlorinated Biphenyls/analysis ; RNA, Ribosomal, 16S ; *Spiders ; }, abstract = {Microbial communities, including endosymbionts, play diverse and critical roles in host biology and reproduction, but contaminant exposure may cause an imbalance in the microbiome composition with subsequent impacts on host health. Here, we examined whether there was a significant alteration of the microbiome community within two taxa of riparian spiders (Tetragnathidae and Araneidae) from a site with historical polychlorinated biphenyl (PCB) contamination in southern Ontario, Canada. Riparian spiders specialize in the predation of adult aquatic insects and, as such, their contaminant levels closely track those of nearby aquatic ecosystems. DNA from whole spiders from sites with either low or high PCB contamination was extracted, and spider microbiota profiled by partial 16S rRNA gene amplicon sequencing. The most prevalent shift in microbial communities we observed was a large reduction in endosymbionts in spiders at the high PCB site. The abundance of endosymbionts at the high PCB site was 63 % and 98 % lower for tetragnathids and araneids, respectively, than at the low PCB site. Overall, this has potential implications for spider reproductive success and food webs, as riparian spiders are critical gatekeepers of energy and material fluxes at the land-water interface.}, }
@article {pmid35715703, year = {2022}, author = {Lan, Y and Sun, J and Chen, C and Wang, H and Xiao, Y and Perez, M and Yang, Y and Kwan, YH and Sun, Y and Zhou, Y and Han, X and Miyazaki, J and Watsuji, TO and Bissessur, D and Qiu, JW and Takai, K and Qian, PY}, title = {Endosymbiont population genomics sheds light on transmission mode, partner specificity, and stability of the scaly-foot snail holobiont.}, journal = {The ISME journal}, volume = {16}, number = {9}, pages = {2132-2143}, pmid = {35715703}, issn = {1751-7370}, mesh = {Animals ; *Hydrothermal Vents/microbiology ; Metagenomics ; Phylogeny ; Snails/physiology ; Symbiosis/genetics ; }, abstract = {The scaly-foot snail (Chrysomallon squamiferum) inhabiting deep-sea hydrothermal vents in the Indian Ocean relies on its sulphur-oxidising gammaproteobacterial endosymbionts for nutrition and energy. In this study, we investigate the specificity, transmission mode, and stability of multiple scaly-foot snail populations dwelling in five vent fields with considerably disparate geological, physical and chemical environmental conditions. Results of population genomics analyses reveal an incongruent phylogeny between the endosymbiont and mitochondrial genomes of the scaly-foot snails in the five vent fields sampled, indicating that the hosts obtain endosymbionts via horizontal transmission in each generation. However, the genetic homogeneity of many symbiont populations implies that vertical transmission cannot be ruled out either. Fluorescence in situ hybridisation of ovarian tissue yields symbiont signals around the oocytes, suggesting that vertical transmission co-occurs with horizontal transmission. Results of in situ environmental measurements and gene expression analyses from in situ fixed samples show that the snail host buffers the differences in environmental conditions to provide the endosymbionts with a stable intracellular micro-environment, where the symbionts serve key metabolic functions and benefit from the host's cushion. The mixed transmission mode, symbiont specificity at the species level, and stable intracellular environment provided by the host support the evolutionary, ecological, and physiological success of scaly-foot snail holobionts in different vents with unique environmental parameters.}, }
@article {pmid35715692, year = {2022}, author = {Hickin, ML and Kakumanu, ML and Schal, C}, title = {Effects of Wolbachia elimination and B-vitamin supplementation on bed bug development and reproduction.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {10270}, pmid = {35715692}, issn = {2045-2322}, mesh = {Animals ; *Bedbugs ; Dietary Supplements ; Female ; Nymph ; Reproduction ; *Vitamin B Complex/pharmacology ; *Wolbachia ; }, abstract = {Obligate blood feeders, such as Cimex lectularius (common bed bug), have symbiotic associations with nutritional endosymbionts that produce B-vitamins. To quantify the symbiont's contribution to host fitness in these obligate mutualisms, the symbiont must be eliminated and its absence rigorously confirmed. We developed and validated procedures for complete elimination of Wolbachia (Wb) in bed bugs and quantified development and reproduction in bed bugs with and without Wb and with and without B-vitamins supplementation. Aposymbiotic bed bugs had slower nymphal development, reduced adult survivorship, smaller adult size, fewer eggs per female, and lower hatch rate than bed bugs that harbored Wb. In aposymbiotic bed bugs that were fed B-vitamins-supplemented blood, nymph development time, adult survivorship and hatch rate recovered to control levels, but adult size and egg number only partially recovered. These results underscore the nutritional dependence of bed bugs on their Wb symbiont and suggest that Wb may provide additional nutritional benefits beyond the B-vitamin mix that we investigated.}, }
@article {pmid35714221, year = {2022}, author = {Li, Y and Altamia, MA and Shipway, JR and Brugler, MR and Bernardino, AF and de Brito, TL and Lin, Z and da Silva Oliveira, FA and Sumida, P and Smith, CR and Trindade-Silva, A and Halanych, KM and Distel, DL}, title = {Contrasting modes of mitochondrial genome evolution in sister taxa of wood-eating marine bivalves (Teredinidae and Xylophagaidae).}, journal = {Genome biology and evolution}, volume = {14}, number = {6}, pages = {}, pmid = {35714221}, issn = {1759-6653}, support = {U19 TW008163/TW/FIC NIH HHS/United States ; }, abstract = {The bivalve families Teredinidae and Xylophagaidae include voracious consumers of wood in shallow and deep-water marine environments, respectively. The taxa are sister clades whose members consume wood as food with the aid of intracellular cellulolytic endosymbionts housed in their gills. This combination of adaptations is found in no other group of animals and was likely present in the common ancestor of both families. Despite these commonalities, the two families have followed dramatically different evolutionary paths with respect to anatomy, life history and distribution. Here we present 42 new mitochondrial genome sequences from Teredinidae and Xylophagaidae and show that distinct trajectories have also occurred in the evolution and organization of their mitochondrial genomes. Teredinidae display significantly greater rates of amino acid substitution but absolute conservation of protein-coding gene order, whereas Xylophagaidae display significantly less amino acid change but have undergone numerous and diverse changes in genome organization since their divergence from a common ancestor. As with many bivalves, these mitochondrial genomes encode two ribosomal RNAs, 12 protein coding genes, and 22 tRNAs; atp8 was not detected. We further show that their phylogeny, as inferred from amino acid sequences of 12 concatenated mitochondrial protein-coding genes, is largely congruent with those inferred from their nuclear genomes based on 18S and 28S ribosomal RNA sequences. Our results provide a robust phylogenetic framework to explore the tempo and mode of mitochondrial genome evolution and offer directions for future phylogenetic and taxonomic studies of wood-boring bivalves.}, }
@article {pmid35707007, year = {2022}, author = {Zhao, R and Li, D and Wang, X and Li, Z and Yu, X and Shentu, X}, title = {Synergistic and Additive Interactions of Zhongshengmycin to the Chemical Insecticide Pymetrozine for Controlling Nilaparvata lugens (Hemiptera: Delphacidae).}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {875610}, pmid = {35707007}, issn = {1664-042X}, abstract = {Management of the rice brown planthopper Nilaparvata lugens Stål is challenging because it can rapidly adapt to new pesticides within several generations. Combined use of chemical insecticides and antimicrobials was proposed as an alternative strategy to control N. lugens. Our previous experiments identified two effective agents (chemical insecticide: pymetrozine and antimicrobial: zhongshengmycin) that act on different targets in N. lugens. However, conditions and effectiveness of combinations of antimicrobials and insecticides against N. lugens are still unknown. Here, we evaluated separate and combined effects of pymetrozine and zhongshengmycin on third instar nymphs of N. lugens under laboratory and greenhouse conditions. Results showed that zhongshengmycin exerts significant inhibitory effects on the three endosymbionts Pichia guilliermondii, Cryptococcus peneaus, and Pichia anomala cultured in vitro of N. lugens. Combinations of pymetrozine and zhongshengmycin under laboratory conditions produced additive or synergistic effects on N. lugens and caused higher mortality in third instar nymphs than either of them used alone. Experiments under greenhouse conditions further demonstrated that effective component quality ratio of pymetrozine to zhongshengmycin of 1:10 and 1:40 with co-toxicity coefficients of 221.63 and 672.87, respectively, also produced significant synergistic effects against N. lugens. Our results indicated that chemical insecticides combined with antimicrobials may provide a potential novel strategy for controlling N. lugens by inhibiting its endosymbionts.}, }
@article {pmid35702810, year = {2022}, author = {Colunga-Salas, P and Sánchez-Montes, S and Torres-Castro, M and Andrade-Torres, A and González, CAL and Aguilar-Tipacamú, G}, title = {Is vertical transmission the only pathway for Rickettsia felis?.}, journal = {Transboundary and emerging diseases}, volume = {69}, number = {5}, pages = {e3352-e3356}, doi = {10.1111/tbed.14626}, pmid = {35702810}, issn = {1865-1682}, mesh = {Animals ; *Flea Infestations/veterinary ; Humans ; Phylogeny ; *Rickettsia/genetics ; *Rickettsia Infections/microbiology/veterinary ; *Rickettsia felis/genetics ; *Siphonaptera/microbiology ; }, abstract = {The genus Rickettsia encompasses several species grouped into two main clusters, Typhus and the Transitional groups. The latter group contains Rickettsia felis, an endosymbiont of several arthropods with an uncertain human pathogenicity and whose most efficient transmission mechanism described thus far is transovarial. The aim of this study was to evaluate whether this pathway exists using phylogenetic analysis and partial sequences of the 17kDa and gltA genes and comparing them with host phylogeny using the cytb region. This is the first study that evaluates the vertical transmission of R. felis. In general, both phylogenies of R. felis showed no polytomies, as suspected if this pathway was the only pathway occurring. When phylogenies of the invertebrates and the gltA of R. felis were compared for strong coevolutionary insight, intricate relationships were observed, suggesting that other transmission pathways must occur, such as horizontal transmission. Further studies are needed to determine which other transmission routes occur in hematophagous arthropods.}, }
@article {pmid35699368, year = {2022}, author = {De Oliveira, AL and Srivastava, A and Espada-Hinojosa, S and Bright, M}, title = {The complete and closed genome of the facultative generalist Candidatus Endoriftia persephone from deep-sea hydrothermal vents.}, journal = {Molecular ecology resources}, volume = {22}, number = {8}, pages = {3106-3123}, doi = {10.1111/1755-0998.13668}, pmid = {35699368}, issn = {1755-0998}, mesh = {DNA Restriction-Modification Enzymes/genetics ; Epigenesis, Genetic ; *Hydrothermal Vents ; Sulfur ; Symbiosis/genetics ; Transposases/genetics ; }, abstract = {The mutualistic interactions between Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone (short Endoriftia) have been extensively researched. However, the closed Endoriftia genome is still lacking. Here, by employing single-molecule real-time sequencing we present the closed chromosomal sequence of Endoriftia. In contrast to theoretical predictions of enlarged and mobile genetic element-rich genomes related to facultative endosymbionts, the closed Endoriftia genome is streamlined with fewer than expected coding sequence regions, insertion-, prophage-sequences and transposase-coding sequences. Automated and manually curated functional analyses indicated that Endoriftia is more versatile regarding sulphur metabolism than previously reported. We identified the presence of two identical rRNA operons and two long CRISPR regions in the closed genome. Additionally, pangenome analyses revealed the presence of three types of secretion systems (II, IV and VI) in the different Endoriftia populations indicating lineage-specific adaptations. The in depth mobilome characterization identified the presence of shared genomic islands in the different Endoriftia drafts and in the closed genome, suggesting that the acquisition of foreign DNA predates the geographical dispersal of the different endosymbiont populations. Finally, we found no evidence of epigenetic regulation in Endoriftia, as revealed by gene screenings and absence of methylated modified base motifs in the genome. As a matter of fact, the restriction-modification system seems to be dysfunctional in Endoriftia, pointing to a higher importance of molecular memory-based immunity against phages via spacer incorporation into CRISPR system. The Endoriftia genome is the first closed tubeworm endosymbiont to date and will be valuable for future gene oriented and evolutionary comparative studies.}, }
@article {pmid35699129, year = {2022}, author = {Mulenga, GM and Namangala, B and Gummow, B}, title = {Prevalence of trypanosomes and selected symbionts in tsetse species of eastern Zambia.}, journal = {Parasitology}, volume = {149}, number = {11}, pages = {1406-1410}, doi = {10.1017/S0031182022000804}, pmid = {35699129}, issn = {1469-8161}, mesh = {Animals ; Enterobacteriaceae/genetics ; Insect Vectors/parasitology ; Prevalence ; *Trypanosoma/genetics ; *Trypanosomiasis, African/parasitology ; *Tsetse Flies/parasitology ; *Wolbachia/genetics ; Zambia/epidemiology ; }, abstract = {Insect symbionts have attracted attention for their potential use as anti-parasitic gene products in arthropod disease vectors. While tsetse species of the Luangwa valley have been extensively studied, less is known about the prevalence of symbionts and their interactions with the trypanosome parasite. Polymerase chain reaction was used to investigate the presence of Wolbachia and Sodalis bacteria, in tsetse flies infected with trypanosomes (Trypanosoma vivax, Trypanosoma congolense and Trypanosoma brucei). Out of 278 captured tsetse flies in eastern Zambia, 95.3% (n = 265, 95% CI = 92.8–97.8) carried endosymbionts: Wolbachia (79.1%, 95% CI 73.9–83.8) and Sodalis (86.3%, 95% CI 81.7–90.1). Overall, trypanosome prevalence was 25.5% (n = 71, 95% CI = 20.4–30.7), 10.8% (n = 30, 95% CI 7.1–14.4) for T. brucei, 1.4% (n = 4, 95% CI = 0.4–3.6) for both T. congolense and T. vivax, and 0.7% (n = 2, 95% CI 0.1–2.6) for T. b. rhodesiense. Out of 240 tsetse flies that were infected with Sodalis, trypanosome infection was reported in 40 tsetse flies (16.7%, 95% CI = 12.0–21.4) while 37 (16.8%, 95% CI 11.9–21.8) of the 220 Wolbachia infected tsetse flies were infected with trypanosomes. There was 1.3 times likelihood of T. brucei infection to be present when Wolbachia was present and 1.7 likelihood of T. brucei infection when Sodalis was present. Overall findings suggest absence of correlation between the presence of tsetse endosymbionts and tsetse with trypanosome infection. Lastly, the presence of pathogenic trypanosomes in tsetse species examined provided insights into the risk communities face, and the importance of African trypanosomiasis in the area.}, }
@article {pmid35695864, year = {2022}, author = {Nadal-Jimenez, P and Siozios, S and Halliday, N and Cámara, M and Hurst, GDD}, title = {Symbiopectobacterium purcellii, gen. nov., sp. nov., isolated from the leafhopper Empoasca decipiens.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {72}, number = {6}, pages = {}, doi = {10.1099/ijsem.0.005440}, pmid = {35695864}, issn = {1466-5034}, mesh = {Animals ; Bacterial Typing Techniques ; Base Composition ; Chromatography, Liquid ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; *Hemiptera ; *Pectobacterium ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Tandem Mass Spectrometry ; }, abstract = {Bacterial endosymbionts are found in multiple arthropod species, where they play crucial roles as nutritional symbionts, defensive symbionts or reproductive parasites. Recent work has highlighted a new clade of heritable microbes within the gammaproteobacteria that enter into both obligate and facultative symbioses, with an obligately required unculturable symbiont recently given the name Candidatus Symbiopectobacterium. In this study, we describe a culturable rod shaped non-flagellated bacterial symbiont from this clade isolated from the leafhopper Empoasca decipiens. The symbiont is related to the transovarially transmitted 'BEV' bacterium that was first isolated from the leafhopper Euscelidius variegatus by Alexander Purcell, and we therefore name the symbiont Symbiopectobacterium purcellii sp. nov., gen. nov. We further report the closed genome sequence for S. purcellii. The genome is atypical for a heritable microbe, being large in size, without profound AT bias and with little evidence of pseudogenization. The genome is predicted to encode Type II, III and VI secretion systems and associated effectors and a non-ribosomal peptide synthase array likely to produce bioactive small molecules. The predicted metabolism is more complete than for other symbionts in the Symbiopectobacterium clade, and the microbe is predicted to synthesize a range of B vitamins. However, Biolog plate results indicate that the metabolism is depauperate compared to the sister clade, represented by Pectobacterium carotovorum. A quorum-sensing pathway related to that of Pectobacterium species (containing an overlapping expI-expR1 pair in opposite directions and a "solo" expR2) is evidenced, and LC-MS/MS analysis reveals the presence of 3-hydroxy-C10-HSL as the sole N-acylhomoserine lactone (AHL) in our strain. This AHL profile is profoundly divergent from that of other Erwinia and Pectobacterium species which produce mostly 3-oxo-C6- and 3-oxo-C8-HSL and could aid group identification. Thus, this microbe denotes one that has lost certain pathways associated with a saprophytic lifestyle but represents an important baseline against which to compare other members of the genus Symbiopectobacterium that show more profound integration into host biology. The type strain of Symbiopectobacterium purcellii gen. nov., sp. nov. is SyEd1[T] (LMG 32449[T]=CECT 30436[T]).}, }
@article {pmid35681493, year = {2022}, author = {Das De, T and Sharma, P and Tevatiya, S and Chauhan, C and Kumari, S and Yadav, P and Singla, D and Srivastava, V and Rani, J and Hasija, Y and Pandey, KC and Kajla, M and Dixit, R}, title = {Bidirectional Microbiome-Gut-Brain-Axis Communication Influences Metabolic Switch-Associated Responses in the Mosquito Anopheles culicifacies.}, journal = {Cells}, volume = {11}, number = {11}, pages = {}, pmid = {35681493}, issn = {2073-4409}, mesh = {Animals ; *Anopheles ; Bacteria/genetics ; Brain/metabolism ; Cell Communication ; Female ; *Gastrointestinal Microbiome/physiology ; }, abstract = {The periodic ingestion of a protein-rich blood meal by adult female mosquitoes causes a drastic metabolic change in their innate physiological status, which is referred to as a 'metabolic switch'. While understanding the neural circuits for host-seeking is modestly attended, how the gut 'metabolic switch' modulates brain functions, and resilience to physiological homeostasis, remains unexplored. Here, through a comparative brain RNA-Seq study, we demonstrate that the protein-rich diet induces the expression of brain transcripts related to mitochondrial function and energy metabolism, possibly causing a shift in the brain's engagement to manage organismal homeostasis. A dynamic mRNA expression pattern of neuro-signaling and neuro-modulatory genes in both the gut and brain likely establishes an active gut-brain communication. The disruption of this communication through decapitation does not affect the modulation of the neuro-modulator receptor genes in the gut. In parallel, an unusual and paramount shift in the level of neurotransmitters (NTs), from the brain to the gut after blood feeding, further supports the idea of the gut's ability to serve as a 'second brain'. After blood-feeding, a moderate enrichment of the gut microbial population, and altered immunity in the gut of histamine receptor-silenced mosquitoes, provide initial evidence that the gut-microbiome plays a crucial role in gut-brain-axis communication. Finally, a comparative metagenomics evaluation of the gut microbiome highlighted that blood-feeding enriches the family members of the Morganellaceae and Pseudomonadaceae bacterial communities. The notable observation of a rapid proliferation of Pseudomonas bacterial sp. and tryptophan enrichment in the gut correlates with the suppression of appetite after blood-feeding. Additionally, altered NTs dynamics of naïve and aseptic mosquitoes provide further evidence that gut-endosymbionts are key modulators for the synthesis of major neuroactive molecules. Our data establish a new conceptual understanding of microbiome-gut-brain-axis communication in mosquitoes.}, }
@article {pmid35678925, year = {2022}, author = {Lin, GW and Chung, CY and Cook, CE and Lin, MD and Lee, WC and Chang, CC}, title = {Germline specification and axis determination in viviparous and oviparous pea aphids: conserved and divergent features.}, journal = {Development genes and evolution}, volume = {232}, number = {2-4}, pages = {51-65}, pmid = {35678925}, issn = {1432-041X}, mesh = {Animals ; *Aphids/physiology ; Female ; Germ Cells ; Insect Proteins ; Oviparity ; Peas ; }, abstract = {Aphids are hemimetabolous insects that undergo incomplete metamorphosis without pupation. The annual life cycle of most aphids includes both an asexual (viviparous) and a sexual (oviparous) phase. Sexual reproduction only occurs once per year and is followed by many generations of asexual reproduction, during which aphids propagate exponentially with telescopic development. Here, we discuss the potential links between viviparous embryogenesis and derived developmental features in the pea aphid Acyrthosiphon pisum, particularly focusing on germline specification and axis determination, both of which are key events of early development in insects. We also discuss potential evolutionary paths through which both viviparous and oviparous females might have come to utilize maternal germ plasm to drive germline specification. This developmental strategy, as defined by germline markers, has not been reported in other hemimetabolous insects. In viviparous females, furthermore, we discuss whether molecules that in other insects characterize germ plasm, like Vasa, also participate in posterior determination and how the anterior localization of the hunchback orthologue Ap-hb establishes the anterior-posterior axis. We propose that the linked chain of developing oocytes and embryos within each ovariole and the special morphology of early embryos might have driven the formation of evolutionary novelties in germline specification and axis determination in the viviparous aphids. Moreover, based upon the finding that the endosymbiont Buchnera aphidicola is closely associated with germ cells throughout embryogenesis, we propose presumptive roles for B. aphidicola in aphid development, discussing how it might regulate germline migration in both reproductive modes of pea aphids. In summary, we expect that this review will shed light on viviparous as well as oviparous development in aphids.}, }
@article {pmid35678589, year = {2022}, author = {Higgins, SA and Mann, M and Heck, M}, title = {Strain Tracking of 'Candidatus Liberibacter asiaticus', the Citrus Greening Pathogen, by High-Resolution Microbiome Analysis of Asian Citrus Psyllids.}, journal = {Phytopathology}, volume = {112}, number = {11}, pages = {2273-2287}, doi = {10.1094/PHYTO-02-22-0067-R}, pmid = {35678589}, issn = {0031-949X}, mesh = {Animals ; *Hemiptera/microbiology ; *Citrus/microbiology ; *Rhizobiaceae/genetics ; Liberibacter ; Plant Diseases/microbiology ; *Microbiota ; }, abstract = {The Asian citrus psyllid, Diaphorina citri, is an invasive insect and a vector of 'Candidatus Liberibacter asiaticus' (CLas), a bacterium whose growth in Citrus species results in huanglongbing (HLB), also known as citrus greening disease. Methods to enrich and sequence CLas from D. citri often rely on biased genome amplification and nevertheless contain significant quantities of host DNA. To overcome these hurdles, we developed a simple pretreatment DNase and filtration (PDF) protocol to remove host DNA and directly sequence CLas and the complete, primarily uncultivable microbiome from D. citri adults. The PDF protocol yielded CLas abundances upward of 60% and facilitated direct measurement of CLas and endosymbiont replication rates in psyllids. The PDF protocol confirmed our lab strains derived from a progenitor Florida CLas strain and accumulated 156 genetic variants, underscoring the utility of this method for bacterial strain tracking. CLas genetic polymorphisms arising in lab-reared psyllid populations included prophage-encoding regions with key functions in CLas pathogenesis, putative antibiotic resistance loci, and a single secreted effector. These variants suggest that laboratory propagation of CLas could result in different phenotypic trajectories among laboratories and could confound CLas physiology or therapeutic design and evaluation if these differences remain undocumented. Finally, we obtained genetic signatures affiliated with Citrus nuclear and organellar genomes, entomopathogenic fungal mitochondria, and commensal bacteria from laboratory-reared and field-collected D. citri adults. Hence, the PDF protocol can directly inform agricultural management strategies related to bacterial strain tracking, insect microbiome surveillance, and antibiotic resistance screening.}, }
@article {pmid35672454, year = {2022}, author = {Pilátová, J and Pánek, T and Oborník, M and Čepička, I and Mojzeš, P}, title = {Revisiting biocrystallization: purine crystalline inclusions are widespread in eukaryotes.}, journal = {The ISME journal}, volume = {16}, number = {9}, pages = {2290-2294}, pmid = {35672454}, issn = {1751-7370}, mesh = {*Biomineralization ; *Eukaryota/genetics/metabolism ; Guanine/metabolism ; Humans ; Purines/metabolism ; }, abstract = {Despite the widespread occurrence of intracellular crystalline inclusions in unicellular eukaryotes, scant attention has been paid to their composition, functions, and evolutionary origins. Using Raman microscopy, we examined >200 species from all major eukaryotic supergroups. We detected cellular crystalline inclusions in 77% species out of which 80% is composed of purines, such as anhydrous guanine (62%), guanine monohydrate (2%), uric acid (12%) and xanthine (4%). Our findings shifts the paradigm assuming predominance of calcite and oxalates. Purine crystals emerge in microorganisms in all habitats, e.g., in freshwater algae, endosymbionts of reef-building corals, deadly parasites, anaerobes in termite guts, or slime molds. Hence, purine biocrystallization is a general and ancestral eukaryotic process likely present in the last eukaryotic common ancestor (LECA) and here we propose two proteins omnipresent in eukaryotes that are likely in charge of their metabolism: hypoxanthine-guanine phosphoribosyl transferase and equilibrative nucleoside transporter. Purine crystalline inclusions are multifunctional structures representing high-capacity and rapid-turnover reserves of nitrogen and optically active elements, e.g., used in light sensing. Thus, we anticipate our work to be a starting point for further studies spanning from cell biology to global ecology, with potential applications in biotechnologies, bio-optics, or in human medicine.}, }
@article {pmid35671755, year = {2022}, author = {Tvedte, ES and Gasser, M and Zhao, X and Tallon, LJ and Sadzewicz, L and Bromley, RE and Chung, M and Mattick, J and Sparklin, BC and Dunning Hotopp, JC}, title = {Accumulation of endosymbiont genomes in an insect autosome followed by endosymbiont replacement.}, journal = {Current biology : CB}, volume = {32}, number = {12}, pages = {2786-2795.e5}, pmid = {35671755}, issn = {1879-0445}, support = {R01 CA206188/CA/NCI NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Chromosomes ; Drosophila/genetics/microbiology ; Gene Transfer, Horizontal ; Genome ; Symbiosis/genetics ; *Wolbachia/genetics ; }, abstract = {Eukaryotic genomes can acquire bacterial DNA via lateral gene transfer (LGT).[1] A prominent source of LGT is Wolbachia,[2] a widespread endosymbiont of arthropods and nematodes that is transmitted maternally through female germline cells.[3,4] The DNA transfer from the Wolbachia endosymbiont wAna to Drosophila ananassae is extensive[5-7] and has been localized to chromosome 4, contributing to chromosome expansion in this lineage.[6] As has happened frequently with claims of bacteria-to-eukaryote LGT, the contribution of wAna transfers to the expanded size of D. ananassae chromosome 4 has been specifically contested[8] owing to an assembly where Wolbachia sequences were classified as contaminants and removed.[9] Here, long-read sequencing with DNA from a Wolbachia-cured line enabled assembly of 4.9 Mbp of nuclear Wolbachia transfers (nuwts) in D. ananassae and a 24-kbp nuclear mitochondrial transfer. The nuwts are <8,000 years old in at least two locations in chromosome 4 with at least one whole-genome integration followed by rapid extensive duplication of most of the genome with regions that have up to 10 copies. The genes in nuwts are accumulating small indels and mobile element insertions. Among the highly duplicated genes are cifA and cifB, two genes associated with Wolbachia-mediated Drosophila cytoplasmic incompatibility. The wAna strain that was the source of nuwts was subsequently replaced by a different wAna endosymbiont. Direct RNA Nanopore sequencing of Wolbachia-cured lines identified nuwt transcripts, including spliced transcripts, but functionality, if any, remains elusive.}, }
@article {pmid35668761, year = {2022}, author = {Djihinto, OY and Medjigbodo, AA and Gangbadja, ARA and Saizonou, HM and Lagnika, HO and Nanmede, D and Djossou, L and Bohounton, R and Sovegnon, PM and Fanou, MJ and Agonhossou, R and Akoton, R and Mousse, W and Djogbénou, LS}, title = {Malaria-Transmitting Vectors Microbiota: Overview and Interactions With Anopheles Mosquito Biology.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {891573}, pmid = {35668761}, issn = {1664-302X}, abstract = {Malaria remains a vector-borne infectious disease that is still a major public health concern worldwide, especially in tropical regions. Malaria is caused by a protozoan parasite of the genus Plasmodium and transmitted through the bite of infected female Anopheles mosquitoes. The control interventions targeting mosquito vectors have achieved significant success during the last two decades and rely mainly on the use of chemical insecticides through the insecticide-treated nets (ITNs) and indoor residual spraying (IRS). Unfortunately, resistance to conventional insecticides currently being used in public health is spreading in the natural mosquito populations, hampering the long-term success of the current vector control strategies. Thus, to achieve the goal of malaria elimination, it appears necessary to improve vector control approaches through the development of novel environment-friendly tools. Mosquito microbiota has by now given rise to the expansion of innovative control tools, such as the use of endosymbionts to target insect vectors, known as "symbiotic control." In this review, we will present the viral, fungal and bacterial diversity of Anopheles mosquitoes, including the bacteriophages. This review discusses the likely interactions between the vector microbiota and its fitness and resistance to insecticides.}, }
@article {pmid35666732, year = {2022}, author = {Bordenstein, SR and Bordenstein, SR}, title = {Widespread phages of endosymbionts: Phage WO genomics and the proposed taxonomic classification of Symbioviridae.}, journal = {PLoS genetics}, volume = {18}, number = {6}, pages = {e1010227}, pmid = {35666732}, issn = {1553-7404}, support = {R01 AI132581/AI/NIAID NIH HHS/United States ; R01 AI143725/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Arthropods ; *Bacteriophages/genetics ; Eukaryota ; Genomics ; Symbiosis/genetics ; *Wolbachia/genetics ; }, abstract = {Wolbachia are the most common obligate, intracellular bacteria in animals. They exist worldwide in arthropod and nematode hosts in which they commonly act as reproductive parasites or mutualists, respectively. Bacteriophage WO, the largest of Wolbachia's mobile elements, includes reproductive parasitism genes, serves as a hotspot for genetic divergence and genomic rearrangement of the bacterial chromosome, and uniquely encodes a Eukaryotic Association Module with eukaryotic-like genes and an ensemble of putative host interaction genes. Despite WO's relevance to genome evolution, selfish genetics, and symbiotic applications, relatively little is known about its origin, host range, diversification, and taxonomic classification. Here we analyze the most comprehensive set of 150 Wolbachia and phage WO assemblies to provide a framework for discretely organizing and naming integrated phage WO genomes. We demonstrate that WO is principally in arthropod Wolbachia with relatives in diverse endosymbionts and metagenomes, organized into four variants related by gene synteny, often oriented opposite the putative origin of replication in the Wolbachia chromosome, and the large serine recombinase is an ideal typing tool to distinguish the four variants. We identify a novel, putative lytic cassette and WO's association with a conserved eleven gene island, termed Undecim Cluster, that is enriched with virulence-like genes. Finally, we evaluate WO-like Islands in the Wolbachia genome and discuss a new model in which Octomom, a notable WO-like Island, arose from a split with WO. Together, these findings establish the first comprehensive Linnaean taxonomic classification of endosymbiont phages, including non-Wolbachia phages from aquatic environments, that includes a new family and two new genera to capture the collective relatedness of these viruses.}, }
@article {pmid35665222, year = {2022}, author = {Steinberg, RK and Ainsworth, TD and Moriarty, T and Bednarek, T and Dafforn, KA and Johnston, EL}, title = {Bleaching Susceptibility and Resistance of Octocorals and Anemones at the World's Southern-Most Coral Reef.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {804193}, pmid = {35665222}, issn = {1664-042X}, abstract = {Coral reefs are amongst the most biodiverse ecosystems on earth, and while stony corals create the foundational complexity of these ecosystems, octocorals and anemones contribute significantly to their biodiversity and function. Like stony corals, many octocorals contain Symbiodiniaceae endosymbionts and can bleach when temperatures exceed the species' upper thermal limit. Here, we report octocoral bleaching susceptibility and resistance within the subtropical Lord Howe Island coral reef ecosystem during and after marine heatwaves in 2019. Octocoral and anemone surveys were conducted at multiple reef locations within the Lord Howe Island lagoon during, immediately after, and 7 months after the heatwaves. One octocoral species, Cladiella sp. 1, experienced bleaching and mortality, with some bleached colonies detaching from the reef structure during the heatwave (presumed dead). Those that remained attached to the benthos survived the event and recovered endosymbionts within 7 months of bleaching. Cladiella sp. 1 Symbiodiniaceae density (in cells per µg protein), chlorophyll a and c 2 per µg protein, and photosynthetic efficiency were significantly lower in bleached colonies compared to unbleached colonies, while chlorophyll a and c 2 per symbiont were higher. Interestingly, no other symbiotic octocoral species of the Lord Howe Island lagoonal reef bleached. Unbleached Xenia cf crassa colonies had higher Symbiodiniaceae and chlorophyll densities during the marine heatwave compared to other monitoring intervals, while Cladiella sp. 2 densities did not change substantially through time. Previous work on octocoral bleaching has focused primarily on gorgonian octocorals, while this study provides insight into bleaching variability in other octocoral groups. The study also provides further evidence that octocorals may be generally more resistant to bleaching than stony corals in many, but not all, reef ecosystems. Responses to marine heating events vary and should be assessed on a species by species basis.}, }
@article {pmid35663891, year = {2022}, author = {James, EB and Pan, X and Schwartz, O and Wilson, ACC}, title = {SymbiQuant: A Machine Learning Object Detection Tool for Polyploid Independent Estimates of Endosymbiont Population Size.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {816608}, pmid = {35663891}, issn = {1664-302X}, abstract = {Quantifying the size of endosymbiont populations is challenging because endosymbionts are typically difficult or impossible to culture and commonly polyploid. Current approaches to estimating endosymbiont population sizes include quantitative PCR (qPCR) targeting endosymbiont genomic DNA and flow-cytometry. While qPCR captures genome copy number data, it does not capture the number of bacterial cells in polyploid endosymbiont populations. In contrast, flow cytometry can capture accurate estimates of whole host-level endosymbiont population size, but it is not readily able to capture data at the level of endosymbiotic host cells. To complement these existing approaches for estimating endosymbiont population size, we designed and implemented an object detection/segmentation tool for counting the number of endosymbiont cells in micrographs of host tissues. The tool, called SymbiQuant, which makes use of recent advances in deep neural networks includes a graphic user interface that allows for human curation of tool output. We trained SymbiQuant for use in the model aphid/Buchnera endosymbiosis and studied Buchnera population dynamics and phenotype over aphid postembryonic development. We show that SymbiQuant returns accurate counts of endosymbionts, and readily captures Buchnera phenotype. By replacing our training data with data composed of annotated microscopy images from other models of endosymbiosis, SymbiQuant has the potential for broad application. Our tool, which is available on GitHub, adds to the repertoire of methods researchers can use to study endosymbiosis at the organismal, genome, and now endosymbiotic host tissue or cell levels.}, }
@article {pmid35662068, year = {2022}, author = {Lu, M and Tang, G and Ren, Z and Zhang, J and Wang, W and Qin, X and Li, K}, title = {Ehrlichia, Coxiella and Bartonella infections in rodents from Guizhou Province, Southwest China.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {5}, pages = {101974}, doi = {10.1016/j.ttbdis.2022.101974}, pmid = {35662068}, issn = {1877-9603}, mesh = {Animals ; *Bartonella/genetics ; *Bartonella Infections/epidemiology/veterinary ; China/epidemiology ; Coxiella/genetics ; Ehrlichia/genetics ; Murinae ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rats ; *Ticks/genetics ; }, abstract = {Rodents are generally recognized to be the reservoir hosts of a great many zoonotic pathogens. In some areas of China, rodent-borne pathogens, as well as the role of rodents in the natural cycle of these pathogens, are still poorly investigated. To increase our knowledge on the distribution and epidemiology of rodent-borne bacterial pathogens, 81 rodent liver samples were collected in three locations of Guizhou province located in Southwest China, and screened for the presence of Ehrlichia, Coxiella, and Bartonella in them. A putative novel Ehrlichia species was identified in 5 Berylmys bowersi samples (100%, 5/5). Its 16S rRNA, gltA, and groEL genes have highest 99.84%, 89.11%, and 98.02% identities to those from known Ehrlichia species, and form distinct clades in the phylogenetic trees. Herein we name it "Candidatus Ehrlichia zunyiensis". Bartonella was tested positive in 8 A. agrarius (striped field mouse), 2 A. chevrieri (Chevrier's field mouse), 1 R. norvegicus (Norway rat), 1 N. confucianus, and 1 N. lotipes, with a total positive rate of 16.05% (13/81). Sequence analysis indicated high genetic diversity in these Bartonella strains. Unexpectedly, two Coxiella strains were identified from the rodents (1 Niviventer confucianus and 1 Mus pahari). Genetic and phylogenetic analysis indicated that both of them are closely related to the Coxiella endosymbiont of ticks. This result supported previous conjectures that vertebrate hosts such as rodents may play a role in the preservation and transmission of Coxiella endosymbiont of ticks.}, }
@article {pmid35660157, year = {2022}, author = {Kohga, H and Mori, T and Tanaka, Y and Yoshikaie, K and Taniguchi, K and Fujimoto, K and Fritz, L and Schneider, T and Tsukazaki, T}, title = {Crystal structure of the lipid flippase MurJ in a "squeezed" form distinct from its inward- and outward-facing forms.}, journal = {Structure (London, England : 1993)}, volume = {30}, number = {8}, pages = {1088-1097.e3}, doi = {10.1016/j.str.2022.05.008}, pmid = {35660157}, issn = {1878-4186}, mesh = {Bacterial Proteins/chemistry ; Escherichia coli/chemistry/genetics ; *Escherichia coli Proteins/chemistry ; Lipids ; Peptidoglycan/chemistry ; Phospholipid Transfer Proteins/chemistry ; Protein Conformation ; }, abstract = {The bacterial peptidoglycan enclosing the cytoplasmic membrane is a fundamental cellular architecture. The integral membrane protein MurJ plays an essential role in flipping the cell wall building block Lipid II across the cytoplasmic membrane for peptidoglycan biosynthesis. Previously reported crystal structures of MurJ have elucidated its V-shaped inward- or outward-facing forms with an internal cavity for substrate binding. MurJ transports Lipid II using its cavity through conformational transitions between these two forms. Here, we report two crystal structures of inward-facing forms from Arsenophonus endosymbiont MurJ and an unprecedented crystal structure of Escherichia coli MurJ in a "squeezed" form, which lacks a cavity to accommodate the substrate, mainly because of the increased proximity of transmembrane helices 2 and 8. Subsequent molecular dynamics simulations supported the hypothesis that the squeezed form is an intermediate conformation. This study fills a gap in our understanding of the Lipid II flipping mechanism.}, }
@article {pmid35651643, year = {2022}, author = {Badrulisham, AS and Abu Bakar, MA and Md Zain, BM and Md-Nor, S and Abd Rahman, MR and Mohd-Yusof, NS and Halim, M and Yaakop, S}, title = {Metabarcoding of Parasitic Wasp, Dolichogenidea metesae (Nixon) (Hymenoptera: Braconidae) That Parasitizing Bagworm, Metisa plana Walker (Lepidoptera: Psychidae).}, journal = {Tropical life sciences research}, volume = {33}, number = {1}, pages = {23-42}, pmid = {35651643}, issn = {1985-3718}, abstract = {Microbiome studies of the parasitoid wasp, Dolichogenidea metesae (Nixon) (Hymenoptera, Braconidae) are important because D. metesae has potential as a biological control agent to suppress the pest, Metisa plana Walker (Lepidoptera, Psychidae). Three field populations of parasitic wasps with different Integrated Pest Management (IPM) practices to control M. plana collected from Perak state (Tapah) and Johor state (Yong Peng and Batu Pahat districts) in Peninsular Malaysia were studied. Bacterial community composition and structure were analysed using α and β diversity metrics. Proteobacteria (83.31%) and Bacteroidetes (6.80%) were the most dominant phyla, whereas unknown family from order Rhizobiales was the most abundant family found in all populations followed by Pseudomonadaceae. Family Micrococcaceae was absent in Tapah. Rhizobiales gen. sp. and Pseudomonas sp. were abundant in all populations. Pearson's correlation analysis showed the strongest correlation between individuals of Batu Pahat and Yong Peng (r = 0.89827, p < 0.05), followed by Tapah and Yong Peng with r = 0.75358, p < 0.05 and Batu Pahat and Tapah (r = 0.69552, p < 0.05). We hypothesise that low diversity and richness in Tapah might be due to direct and indirect effect of insecticides application. This preliminary data was the first study to do inventory of the microbiomes in the gut of the D. metesae.}, }
@article {pmid35643082, year = {2022}, author = {Paight, C and Hunter, ES and Lane, CE}, title = {Codependence of individuals in the Nephromyces species swarm requires heterospecific bacterial endosymbionts.}, journal = {Current biology : CB}, volume = {32}, number = {13}, pages = {2948-2955.e4}, pmid = {35643082}, issn = {1879-0445}, support = {R03 AI124092/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Apicomplexa ; Bacteria/genetics ; Codependency, Psychological ; Genome, Bacterial ; Phylogeny ; Symbiosis ; *Urochordata/genetics ; }, abstract = {Symbiosis is one of the most important evolutionary processes shaping the biodiversity on Earth. Symbiotic associations often bring together organisms from different domains of life, which can provide an unparalleled route to evolutionary innovation.[1-4] The phylum Apicomplexa encompasses 6,000 ubiquitous animal parasites; however, species in the recently described apicomplexan family, Nephromycidae, are reportedly non-virulent.[5][,][6] The members of the genus Nephromyces live within a specialized organ of tunicates, called the renal sac, in which they use concentrated uric acid as a primary nitrogen source.[7][,][8] Here, we report genomic and transcriptomic data from the diverse genus Nephromyces, as well as the three bacterial symbionts that live within this species complex. We show that the diversity of Nephromyces is unexpectedly high within each renal sac, with as many as 20 different species inhabiting the renal sacs in wild populations. The many species of Nephromyces can host three different types of bacterial endosymbionts; however, FISH microscopy allowed us to demonstrate that each individual Nephromyces cell hosts only a single bacterial type. Through the reconstruction and analyses of the endosymbiont bacterial genomes, we infer that each bacterial type supplies its host with different metabolites. No individual species of Nephromyces, in combination with its endosymbiont, can produce a complete set of essential amino acids, and culture experiments demonstrate that individual Nephromyces species cannot form a viable infection. Therefore, we hypothesize that Nephromyces spp. depend on co-infection with congeners containing different bacterial symbionts in order to exchange metabolites to meet their needs.}, }
@article {pmid35642381, year = {2022}, author = {Liu, W and Smith, DAS and Raina, G and Stanforth, R and Ng'Iru, I and Ireri, P and Martins, DJ and Gordon, IJ and Martin, SH}, title = {Global biogeography of warning coloration in the butterfly Danaus chrysippus.}, journal = {Biology letters}, volume = {18}, number = {6}, pages = {20210639}, pmid = {35642381}, issn = {1744-957X}, mesh = {Adaptation, Biological ; Animals ; Biological Evolution ; *Butterflies/genetics ; Citizen Science ; Gene Frequency ; Phenotype ; *Pigmentation ; Predatory Behavior ; Selection, Genetic ; }, abstract = {Warning coloration provides a textbook example of natural selection, but the frequent observation of polymorphism in aposematic species presents an evolutionary puzzle. We investigated biogeography and polymorphism of warning patterns in the widespread butterfly Danaus chrysippus using records from citizen science (n = 5467), museums (n = 8864) and fieldwork (n = 2586). We find that polymorphism in three traits controlled by known mendelian loci is extensive. Broad allele frequency clines, hundreds of kilometres wide, suggest a balance between long-range dispersal and predation of unfamiliar morphs. Mismatched clines for the white hindwing and forewing tip in East Africa are consistent with a previous finding that the black wingtip allele has spread recently in the region through hitchhiking with a heritable endosymbiont. Light/dark background coloration shows more extensive polymorphism. The darker genotype is more common in cooler regions, possibly reflecting a trade-off between thermoregulation and predator warning. Overall, our findings show how studying local adaptation at the global scale provides a more complete picture of the evolutionary forces involved.}, }
@article {pmid35639693, year = {2022}, author = {Calatrava, V and Stephens, TG and Gabr, A and Bhaya, D and Bhattacharya, D and Grossman, AR}, title = {Retrotransposition facilitated the establishment of a primary plastid in the thecate amoeba Paulinella.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {119}, number = {23}, pages = {e2121241119}, pmid = {35639693}, issn = {1091-6490}, mesh = {*Amoeba/genetics ; *Biological Evolution ; Eukaryota/genetics ; Plastids/genetics ; *Rhizaria ; *Symbiosis/genetics ; }, abstract = {The evolution of eukaryotic life was predicated on the development of organelles such as mitochondria and plastids. During this complex process of organellogenesis, the host cell and the engulfed prokaryote became genetically codependent, with the integration of genes from the endosymbiont into the host nuclear genome and subsequent gene loss from the endosymbiont. This process required that horizontally transferred genes become active and properly regulated despite inherent differences in genetic features between donor (endosymbiont) and recipient (host). Although this genetic reorganization is considered critical for early stages of organellogenesis, we have little knowledge about the mechanisms governing this process. The photosynthetic amoeba Paulinella micropora offers a unique opportunity to study early evolutionary events associated with organellogenesis and primary endosymbiosis. This amoeba harbors a “chromatophore,” a nascent photosynthetic organelle derived from a relatively recent cyanobacterial association (∼120 million years ago) that is independent of the evolution of primary plastids in plants (initiated ∼1.5 billion years ago). Analysis of the genome and transcriptome of Paulinella revealed that retrotransposition of endosymbiont-derived nuclear genes was critical for their domestication in the host. These retrocopied genes involved in photoprotection in cyanobacteria became expanded gene families and were “rewired,” acquiring light-responsive regulatory elements that function in the host. The establishment of host control of endosymbiont-derived genes likely enabled the cell to withstand photo-oxidative stress generated by oxygenic photosynthesis in the nascent organelle. These results provide insights into the genetic mechanisms and evolutionary pressures that facilitated the metabolic integration of the host–endosymbiont association and sustained the evolution of a photosynthetic organelle.}, }
@article {pmid35639004, year = {2022}, author = {Maruyama, S and Mandelare-Ruiz, PE and McCauley, M and Peng, W and Cho, BG and Wang, J and Mechref, Y and Loesgen, S and Weis, VM}, title = {Heat Stress of Algal Partner Hinders Colonization Success and Alters the Algal Cell Surface Glycome in a Cnidarian-Algal Symbiosis.}, journal = {Microbiology spectrum}, volume = {10}, number = {3}, pages = {e0156722}, pmid = {35639004}, issn = {2165-0497}, support = {R01 GM112490/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Dinoflagellida/metabolism ; Heat-Shock Response ; Polysaccharides ; *Sea Anemones ; Symbiosis ; }, abstract = {Corals owe their ecological success to their symbiotic relationship with dinoflagellate algae (family Symbiodiniaceae). While the negative effects of heat stress on this symbiosis are well studied, how heat stress affects the onset of symbiosis and symbiont specificity is less explored. In this work, we used the model sea anemone, Exaiptasia diaphana (commonly referred to as Aiptasia), and its native symbiont, Breviolum minutum, to study the effects of heat stress on the colonization of Aiptasia by algae and the algal cell-surface glycome. Heat stress caused a decrease in the colonization of Aiptasia by algae that were not due to confounding variables such as algal motility or oxidative stress. With mass spectrometric analysis and lectin staining, a thermally induced enrichment of glycans previously found to be associated with free-living strains of algae (high-mannoside glycans) and a concomitant reduction in glycans putatively associated with symbiotic strains of algae (galactosylated glycans) were identified. Differential enrichment of specific sialic acid glycans was also identified, although their role in this symbiosis remains unclear. We also discuss the methods used to analyze the cell-surface glycome of algae, evaluate current limitations, and provide suggestions for future work in algal-coral glycobiology. Overall, this study provided insight into how stress may affect the symbiosis between cnidarians and their algal symbionts by altering the glycome of the symbiodinian partner. IMPORTANCE Coral reefs are under threat from global climate change. Their decline is mainly caused by the fragility of their symbiotic relationship with dinoflagellate algae which they rely upon for their ecological success. To better understand coral biology, researchers used the sea anemone, Aiptasia, a model system for the study of coral-algal symbiosis, and characterized how heat stress can alter the algae's ability to communicate to the coral host. This study found that heat stress caused a decline in algal colonization success and impacted the cell surface molecules of the algae such that it became more like that of nonsymbiotic species of algae. This work adds to our understanding of the molecular signals involved in coral-algal symbiosis and how it breaks down during heat stress.}, }
@article {pmid35638879, year = {2022}, author = {Chetri, SPK and Rahman, Z and Thomas, L and Lal, R and Gour, T and Agarwal, LK and Vashishtha, A and Kumar, S and Kumar, G and Kumar, R and Sharma, K}, title = {Paradigms of actinorhizal symbiosis under the regime of global climatic changes: New insights and perspectives.}, journal = {Journal of basic microbiology}, volume = {62}, number = {7}, pages = {764-778}, doi = {10.1002/jobm.202200043}, pmid = {35638879}, issn = {1521-4028}, mesh = {Climate Change ; Ecosystem ; Fagales/microbiology ; *Frankia/genetics ; Nitrogen/metabolism ; Nitrogen Fixation ; Phylogeny ; *Symbiosis/genetics ; }, abstract = {Nitrogen occurs as inert and inaccessible dinitrogen gaseous form (N2) in the atmosphere. Biological nitrogen fixation is a chief process that makes this dinitrogen (N2) accessible and bioavailable in the form of ammonium (NH4 [+]) ions. The key organisms to fix nitrogen are certain prokaryotes, called diazotrophs either in the free-living form or establishing significant mutual relationships with a variety of plants. On such examples is ~95-100 MY old incomparable symbiosis between dicotyledonous trees and a unique actinobacterial diazotroph in diverse ecosystems. In this association, the root of the certain dicotyledonous tree (~25 genera and 225 species) belonging to three different taxonomic orders, Fagales, Cucurbitales, and Rosales (FaCuRo) known as actinorhizal trees can host a diazotroph, Frankia of order Frankiales. Frankia is gram-positive, branched, filamentous, sporulating, and free-living soil actinobacterium. It resides in the specialized, multilobed, and coralloid organs (lateral roots but without caps), the root nodules of actinorhizal tress. This review aims to provide systematic information on the distribution and the phylogenetic diversity of hosts from FaCuRo and their micro-endosymbionts (Frankia spp.), colonization mechanisms, and signaling pathways. We also aim to provide details on developmental and physiological imperatives for gene regulation and functional genomics of symbiosis, phenomenal restoration ecology, influences of contemporary global climatic changes, and anthropogenic impacts on plant-Frankia interactions for the functioning of ecosystems and the biosphere.}, }
@article {pmid35631127, year = {2022}, author = {Lu, M and Tian, J and Zhao, H and Jiang, H and Qin, X and Wang, W and Li, K}, title = {Molecular Survey of Vector-Borne Pathogens in Ticks, Sheep Keds, and Domestic Animals from Ngawa, Southwest China.}, journal = {Pathogens (Basel, Switzerland)}, volume = {11}, number = {5}, pages = {}, pmid = {35631127}, issn = {2076-0817}, abstract = {Vector-borne pathogens are mainly transmitted by blood-feeding arthropods such as ticks, mosquitoes, fleas, lice, mites, etc. They pose a significant threat to animal and human health due to their worldwide distribution. Although much work has been performed on these pathogens, some neglected areas and undiscovered pathogens are still to be further researched. In this study, ticks (Haemaphysalis qinghaiensis), sheep keds (Melophagus ovinus), and blood samples from yaks and goats were collected in Ngawa Tibetan and Qiang Autonomous Prefecture located on the eastern edge of the Qinghai-Tibet Plateau, Southwest China. Several vector-borne bacterial pathogens were screened and studied. Anaplasma bovis strains representing novel genotypes were detected in ticks (8.83%, 37/419), yak blood samples (45.71%, 64/140), and goat blood samples (58.93%, 33/56). Two spotted fever group (SFG) Rickettsiae, Candidatus Rickettsia jingxinensis, and a novel Rickettsia species named Candidatus Rickettsia hongyuanensis were identified in ticks. Another Rickettsia species closely related to the Rickettsia endosymbiont of Polydesmus complanatus was also detected in ticks. Furthermore, a Coxiella species was detected in ticks (3.34%, 14/419), keds (1.89%, 2/106), and yak blood (0.71%, 1/140). Interestingly, another Coxiella species and a Coxiella-like bacterium were detected in a tick and a goat blood sample, respectively. These results indicate the remarkable diversity of vector-borne pathogens circulating in this area. Further investigations on their pathogenicity to humans and domestic animals are still needed.}, }
@article {pmid35630383, year = {2022}, author = {Csorba, AB and Fora, CG and Bálint, J and Felföldi, T and Szabó, A and Máthé, I and Loxdale, HD and Kentelky, E and Nyárádi, II and Balog, A}, title = {Endosymbiotic Bacterial Diversity of Corn Leaf Aphid, Rhopalosiphum maidis Fitch (Hemiptera: Aphididae) Associated with Maize Management Systems.}, journal = {Microorganisms}, volume = {10}, number = {5}, pages = {}, pmid = {35630383}, issn = {2076-2607}, abstract = {In this study, different maize fields cultivated under different management systems were sampled to test corn leaf aphid, Rhopalosiphum maidis, populations in terms of total and endosymbiotic bacterial diversity. Corn leaf aphid natural populations were collected from traditionally managed maize fields grown under high agricultural and natural landscape diversity as well as conventionally treated high-input agricultural fields grown in monoculture and with fertilizers use, hence with low natural landscape diversity. Total bacterial community assessment by DNA sequencing was performed using the Illumina MiSeq platform. In total, 365 bacterial genera were identified and 6 endosymbiont taxa. A high abundance of the primary endosymbiont Buchnera and secondary symbionts Serratia and Wolbachia were detected in all maize crops. Their frequency was found to be correlated with the maize management system used, probably with fertilizer input. Three other facultative endosymbionts ("Candidatus Hamiltonella", an uncultured Rickettsiales genus, and Spiroplasma) were also recorded at different frequencies under the two management regimes. Principal components analyses revealed that the relative contribution of the obligate and dominant symbiont Buchnera to the aphid endosymbiotic bacterial community was 72%, whereas for the managed system this was only 16.3%. When facultative symbionts alone were considered, the effect of management system revealed a DNA diversity of 23.3%.}, }
@article {pmid35627785, year = {2022}, author = {Salomon, J and Fernandez Santos, NA and Zecca, IB and Estrada-Franco, JG and Davila, E and Hamer, GL and Rodriguez Perez, MA and Hamer, SA}, title = {Brown Dog Tick (Rhipicephalus sanguineus Sensu Lato) Infection with Endosymbiont and Human Pathogenic Rickettsia spp., in Northeastern México.}, journal = {International journal of environmental research and public health}, volume = {19}, number = {10}, pages = {}, pmid = {35627785}, issn = {1660-4601}, mesh = {Animals ; *Dog Diseases/epidemiology ; Dogs ; Humans ; Mexico/epidemiology ; *Rhipicephalus sanguineus/microbiology ; *Rickettsia/genetics ; *Tick Infestations/epidemiology/veterinary ; }, abstract = {Of the documented tick-borne diseases infecting humans in México, Rocky Mountain spotted fever (RMSF), caused by the Gram-negative bacterium Rickettsia rickettsii, is responsible for most fatalities. Given recent evidence of brown dog tick, Rhipicephalus sanguineus s.l., as an emerging vector of human RMSF, we aimed to evaluate dogs and their ticks for rickettsiae infections as an initial step in assessing the establishment of this pathosystem in a poorly studied region of northeastern México while evaluating the use of dogs as sentinels for transmission/human disease risk. We sampled owned dogs living in six disadvantaged neighborhoods of Reynosa, northeastern México to collect whole blood and ticks. Of 168 dogs assessed, tick infestation prevalence was 53%, composed of exclusively Rh. sanguineus s. l. (n = 2170 ticks). Using PCR and sequencing, we identified an overall rickettsiae infection prevalence of 4.1% (n = 12/292) in ticks, in which eight dogs harbored at least one infected tick. Rickettsiae infections included Rickettsia amblyommatis and Rickettsia parkeri, both of which are emerging human pathogens, as well as Candidatus Rickettsia andeanae. This is the first documentation of pathogenic Rickettsia species in Rh. sanguineus s.l. collected from dogs from northeastern México. Domestic dog infestation with Rickettsia-infected ticks indicates ongoing transmission; thus, humans are at risk for exposure, and this underscores the importance of public and veterinary health surveillance for these pathogens.}, }
@article {pmid35624491, year = {2022}, author = {Arora, J and Kinjo, Y and Šobotník, J and Buček, A and Clitheroe, C and Stiblik, P and Roisin, Y and Žifčáková, L and Park, YC and Kim, KY and Sillam-Dussès, D and Hervé, V and Lo, N and Tokuda, G and Brune, A and Bourguignon, T}, title = {The functional evolution of termite gut microbiota.}, journal = {Microbiome}, volume = {10}, number = {1}, pages = {78}, pmid = {35624491}, issn = {2049-2618}, mesh = {Animals ; *Gastrointestinal Microbiome/genetics ; *Isoptera ; Metagenome ; Phylogeny ; Soil ; }, abstract = {BACKGROUND: Termites primarily feed on lignocellulose or soil in association with specific gut microbes. The functioning of the termite gut microbiota is partly understood in a handful of wood-feeding pest species but remains largely unknown in other taxa. We intend to fill this gap and provide a global understanding of the functional evolution of termite gut microbiota.<br><br>RESULTS: We sequenced the gut metagenomes of 145 samples representative of the termite diversity. We show that the prokaryotic fraction of the gut microbiota of all termites possesses similar genes for carbohydrate and nitrogen metabolisms, in proportions varying with termite phylogenetic position and diet. The presence of a conserved set of gut prokaryotic genes implies that essential nutritional functions were present in the ancestor of modern termites. Furthermore, the abundance of these genes largely correlated with the host phylogeny. Finally, we found that the adaptation to a diet of soil by some termite lineages was accompanied by a change in the stoichiometry of genes involved in important nutritional functions rather than by the acquisition of new genes and pathways.<br><br>CONCLUSIONS: Our results reveal that the composition and function of termite gut prokaryotic communities have been remarkably conserved since termites first appeared ~ 150 million years ago. Therefore, the "world's smallest bioreactor" has been operating as a multipartite symbiosis composed of termites, archaea, bacteria, and cellulolytic flagellates since its inception. Video Abstract.}, }
@article {pmid35618596, year = {2022}, author = {Leister, D and Marino, G and Minagawa, J and Dann, M}, title = {An ancient function of PGR5 in iron delivery?.}, journal = {Trends in plant science}, volume = {27}, number = {10}, pages = {971-980}, doi = {10.1016/j.tplants.2022.04.006}, pmid = {35618596}, issn = {1878-4372}, support = {854126/ERC_/European Research Council/International ; }, mesh = {Antimycin A/pharmacology ; *Arabidopsis Proteins/metabolism ; Electron Transport/physiology ; Ferritins/metabolism/pharmacology ; Iron/metabolism ; Photosynthesis/physiology ; *Photosystem I Protein Complex/metabolism ; Protons ; }, abstract = {In all phototrophic organisms, the photosynthetic apparatus must be protected from light-induced damage. One important mechanism that mitigates photodamage in plants is antimycin A (AA)-sensitive cyclic electron flow (CEF), the evolution of which remains largely obscure. Here we show that proton gradient regulation 5 (PGR5), a key protein involved in AA-sensitive CEF, displays intriguing commonalities - including sequence and structural features - with a group of ferritin-like proteins. We therefore propose that PGR5 may originally have been involved in prokaryotic iron mobilization and delivery, which facilitated a primordial type of CEF as a side effect. The abandonment of the bacterioferritin system during the transformation of cyanobacterial endosymbionts into chloroplasts might have allowed PGR5 to functionally specialize in CEF.}, }
@article {pmid35611654, year = {2022}, author = {Robes, JMD and Altamia, MA and Murdock, EG and Concepcion, GP and Haygood, MG and Puri, AW}, title = {A Conserved Biosynthetic Gene Cluster Is Regulated by Quorum Sensing in a Shipworm Symbiont.}, journal = {Applied and environmental microbiology}, volume = {88}, number = {11}, pages = {e0027022}, pmid = {35611654}, issn = {1098-5336}, support = {R00 GM118762/GM/NIGMS NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics ; *Bivalvia/microbiology ; *Gammaproteobacteria/genetics ; Multigene Family ; Phylogeny ; Quorum Sensing ; Symbiosis ; }, abstract = {Bacterial symbionts often provide critical functions for their hosts. For example, wood-boring bivalves called shipworms rely on cellulolytic endosymbionts for wood digestion. However, how the relationship between shipworms and their bacterial symbionts is formed and maintained remains unknown. Quorum sensing (QS) often plays an important role in regulating symbiotic relationships. We identified and characterized a QS system found in Teredinibacter sp. strain 2052S, a gill isolate of the wood-boring shipworm Bactronophorus cf. thoracites. We determined that 2052S produces the signal N-decanoyl-l-homoserine lactone (C10-HSL) and that this signal controls the activation of a biosynthetic gene cluster colocated in the symbiont genome that is conserved among all symbiotic Teredinibacter isolates. We subsequently identified extracellular metabolites associated with the QS regulon, including ones linked to the conserved biosynthetic gene cluster, using mass spectrometry-based molecular networking. Our results demonstrate that QS plays an important role in regulating secondary metabolism in this shipworm symbiont. This information provides a step toward deciphering the molecular details of the relationship between these symbionts and their hosts. Furthermore, because shipworm symbionts harbor vast yet underexplored biosynthetic potential, understanding how their secondary metabolism is regulated may aid future drug discovery efforts using these organisms. IMPORTANCE Bacteria play important roles as symbionts in animals ranging from invertebrates to humans. Despite this recognized importance, much is still unknown about the molecular details of how these relationships are formed and maintained. One of the proposed roles of shipworm symbionts is the production of bioactive secondary metabolites due to the immense biosynthetic potential found in shipworm symbiont genomes. Here, we report that a shipworm symbiont uses quorum sensing to coordinate activation of its extracellular secondary metabolism, including the transcriptional activation of a biosynthetic gene cluster that is conserved among many shipworm symbionts. This work is a first step toward linking quorum sensing, secondary metabolism, and symbiosis in wood-boring shipworms.}, }
@article {pmid35608298, year = {2022}, author = {Margarita, V and Bailey, NP and Rappelli, P and Diaz, N and Dessì, D and Fettweis, JM and Hirt, RP and Fiori, PL}, title = {Two Different Species of Mycoplasma Endosymbionts Can Influence Trichomonas vaginalis Pathophysiology.}, journal = {mBio}, volume = {13}, number = {3}, pages = {e0091822}, pmid = {35608298}, issn = {2150-7511}, support = {BB/M011186/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Ecosystem ; Female ; Humans ; *Mycoplasma/genetics ; Mycoplasma hominis/genetics ; *Trichomonas Infections/microbiology ; *Trichomonas vaginalis/genetics ; }, abstract = {Trichomonas vaginalis can host the endosymbiont Mycoplasma hominis, an opportunistic pathogenic bacterium capable of modulating T. vaginalis pathobiology. Recently, a new noncultivable mycoplasma, "Candidatus Mycoplasma girerdii," has been shown to be closely associated with women affected by trichomoniasis, suggesting a biological association. Although several features of "Ca. M. girerdii" have been investigated through genomic analysis, the nature of the potential T. vaginalis-"Ca. M. girerdii" consortium and its impact on the biology and pathogenesis of both microorganisms have not yet been explored. Here, we investigate the association between "Ca. M. girerdii" and T. vaginalis isolated from patients affected by trichomoniasis, demonstrating their intracellular localization. By using an in vitro model system based on single- and double-Mycoplasma infection of Mycoplasma-free isogenic T. vaginalis, we investigated the ability of the protist to establish a relationship with the bacteria and impact T. vaginalis growth. Our data indicate likely competition between M. hominis and "Ca. M. girerdii" while infecting trichomonad cells. Comparative dual-transcriptomics data showed major shifts in parasite gene expression in response to the presence of Mycoplasma, including genes associated with energy metabolism and pathogenesis. Consistent with the transcriptomics data, both parasite-mediated hemolysis and binding to host epithelial cells were significantly upregulated in the presence of either Mycoplasma species. Taken together, these results support a model in which this microbial association could modulate the virulence of T. vaginalis. IMPORTANCE T. vaginalis and M. hominis form a unique case of endosymbiosis that modulates the parasite's pathobiology. Recently, a new nonculturable mycoplasma species ("Candidatus Mycoplasma girerdii") has been described as closely associated with the protozoon. Here, we report the characterization of this endosymbiotic relationship. Clinical isolates of the parasite demonstrate that mycoplasmas are common among trichomoniasis patients. The relationships are studied by devising an in vitro system of single and/or double infections in isogenic protozoan recipients. Comparative growth experiments and transcriptomics data demonstrate that the composition of different microbial consortia influences the growth of the parasite and significantly modulates its transcriptomic profile, including metabolic enzymes and virulence genes such as adhesins and pore-forming proteins. The data on modulation from RNA sequencing (RNA-Seq) correlated closely with those of the cytopathic effect and adhesion to human target cells. We propose the hypothesis that the presence and the quantitative ratios of endosymbionts may contribute to modulating protozoan virulence. Our data highlight the importance of considering pathogenic entities as microbial ecosystems, reinforcing the importance of the development of integrated diagnostic and therapeutic strategies.}, }
@article {pmid35606844, year = {2022}, author = {Sparagon, WJ and Gentry, EC and Minich, JJ and Vollbrecht, L and Laurens, LML and Allen, EE and Sims, NA and Dorrestein, PC and Kelly, LW and Nelson, CE}, title = {Fine scale transitions of the microbiota and metabolome along the gastrointestinal tract of herbivorous fishes.}, journal = {Animal microbiome}, volume = {4}, number = {1}, pages = {33}, pmid = {35606844}, issn = {2524-4671}, abstract = {BACKGROUND: Gut microorganisms aid in the digestion of food by providing exogenous metabolic pathways to break down organic compounds. An integration of longitudinal microbial and chemical data is necessary to illuminate how gut microorganisms supplement the energetic and nutritional requirements of animals. Although mammalian gut systems are well-studied in this capacity, the role of microbes in the breakdown and utilization of recalcitrant marine macroalgae in herbivorous fish is relatively understudied and an emerging priority for bioproduct extraction. Here we use a comprehensive survey of the marine herbivorous fish gut microbial ecosystem via parallel 16S rRNA gene amplicon profiling (microbiota) and untargeted tandem mass spectrometry (metabolomes) to demonstrate consistent transitions among 8 gut subsections across five fish of the genus of Kyphosus.<br><br>RESULTS: Integration of microbial phylogenetic and chemical diversity data reveals that microbial communities and metabolomes covaried and differentiated continuously from stomach to hindgut, with the midgut containing multiple distinct and previously uncharacterized microenvironments and a distinct hindgut community dominated by obligate anaerobes. This differentiation was driven primarily by anaerobic gut endosymbionts of the classes Bacteroidia and Clostridia changing in concert with bile acids, small peptides, and phospholipids: bile acid deconjugation associated with early midgut microbiota, small peptide production associated with midgut microbiota, and phospholipid production associated with hindgut microbiota.<br><br>CONCLUSIONS: The combination of microbial and untargeted metabolomic data at high spatial resolution provides a new view of the diverse fish gut microenvironment and serves as a foundation to understand functional partitioning of microbial activities that contribute to the digestion of complex macroalgae in herbivorous marine fish.}, }
@article {pmid35602967, year = {2022}, author = {Pollmann, M and Moore, LD and Krimmer, E and D'Alvise, P and Hasselmann, M and Perlman, SJ and Ballinger, MJ and Steidle, JLM and Gottlieb, Y}, title = {Highly transmissible cytoplasmic incompatibility by the extracellular insect symbiont Spiroplasma.}, journal = {iScience}, volume = {25}, number = {5}, pages = {104335}, pmid = {35602967}, issn = {2589-0042}, abstract = {Cytoplasmic incompatibility (CI) is a form of reproductive manipulation caused by maternally inherited endosymbionts infecting arthropods, like Wolbachia, whereby matings between infected males and uninfected females produce few or no offspring. We report the discovery of a new CI symbiont, a strain of Spiroplasma causing CI in the parasitoid wasp Lariophagus distinguendus. Its extracellular occurrence enabled us to establish CI in uninfected adult insects by transferring Spiroplasma-infected hemolymph. We sequenced the CI-Spiroplasma genome and did not find any homologues of any of the cif genes discovered to cause CI in Wolbachia, suggesting independent evolution of CI. Instead, the genome contains other potential CI-causing candidate genes, such as homologues of high-mobility group (HMG) box proteins that are crucial in eukaryotic development but rare in bacterial genomes. Spiroplasma's extracellular nature and broad host range encompassing medically and agriculturally important arthropods make it a promising tool to study CI and its applications.}, }
@article {pmid35598650, year = {2022}, author = {Louzada-Flores, VN and Kramer, L and Brianti, E and Napoli, E and Mendoza-Roldan, JA and Bezerra-Santos, MA and Latrofa, MS and Otranto, D}, title = {Treatment with doxycycline is associated with complete clearance of circulating Wolbachia DNA in Dirofilaria immitis-naturally infected dogs.}, journal = {Acta tropica}, volume = {232}, number = {}, pages = {106513}, doi = {10.1016/j.actatropica.2022.106513}, pmid = {35598650}, issn = {1873-6254}, mesh = {Animals ; *Cell-Free Nucleic Acids ; *Dirofilaria immitis/genetics ; *Dirofilariasis/drug therapy ; *Dog Diseases/parasitology ; Dogs ; Doxycycline/pharmacology/therapeutic use ; *Wolbachia/genetics ; }, abstract = {Bacteria of the genus Wolbachia are endosymbionts of parasitic filarial nematodes, including Dirofilaria immitis, and are a target for the treatment of canine heartworm disease. In the present study, 53 naturally-infected dogs were divided in three groups, based on their positivity to D. immitis by antigen and Knott tests, to assess the efficacy of doxycycline treatment in eliminating Wolbachia from circulating blood. At T0, dogs that scored positive to both tests (G1) or to antigen only (G2) were submitted to doxycycline (10 mg/kg BID PO) treatment and to 10% Imidacloprid + 2.5% Moxidectin (Advocate®), while those negative to both tests (G3) received only 10% Imidacloprid + 2.5% Moxidectin (Advocate®). All dogs were followed-up for one year, monthly treated with Advocate® and regularly monitored by antigen and Knott tests. During the whole period, all blood samples were screened for Wolbachia-D. immitis DNA load by quantitative real-time PCR (qPCR). At T0, 88.2% of the microfilariemic dogs were positive for Wolbachia DNA, while none of the dogs from G2 or G3 were positive. Wolbachia DNA was no longer detectable in dogs from G1 following 1 month of doxycycline treatment and microfilariae (mfs) were cleared at T2. All dogs from the G1 and G2 were negative for D. immitis antigen at 12 months. Results of this study suggest that successful elimination of mfs by doxycycline is associated with complete clearance of Wolbachia DNA in D. immitis-naturally infected dogs.}, }
@article {pmid35592653, year = {2022}, author = {Verhoeve, VI and Fauntleroy, TD and Risteen, RG and Driscoll, TP and Gillespie, JJ}, title = {Cryptic Genes for Interbacterial Antagonism Distinguish Rickettsia Species Infecting Blacklegged Ticks From Other Rickettsia Pathogens.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {880813}, pmid = {35592653}, issn = {2235-2988}, support = {R21 AI146773/AI/NIAID NIH HHS/United States ; R21 AI156762/AI/NIAID NIH HHS/United States ; R21 AI166832/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antidotes ; Humans ; *Ixodes/microbiology ; Mammals ; Phylogeny ; *Rickettsia/genetics ; Symbiosis ; }, abstract = {BACKGROUND: The genus Rickettsia (Alphaproteobacteria: Rickettsiales) encompasses numerous obligate intracellular species with predominantly ciliate and arthropod hosts. Notable species are pathogens transmitted to mammals by blood-feeding arthropods. Mammalian pathogenicity evolved from basal, non-pathogenic host-associations; however, some non-pathogens are closely related to pathogens. One such species, Rickettsia buchneri, is prevalent in the blacklegged tick, Ixodes scapularis. While I. scapularis transmits several pathogens to humans, it does not transmit Rickettsia pathogens. We hypothesize that R. buchneri established a mutualism with I. scapularis, blocking tick superinfection with Rickettsia pathogens.<br><br>METHODS: To improve estimates for assessing R. buchneri infection frequency in blacklegged tick populations, we used comparative genomics to identify an R. buchneri gene (REIS_1424) not present in other Rickettsia species present throughout the I. scapularis geographic range. Bioinformatic and phylogenomics approaches were employed to propose a function for the hypothetical protein (263 aa) encoded by REIS_1424.<br><br>RESULTS: REIS_1424 has few analogs in other Rickettsiales genomes and greatest similarity to non-Proteobacteria proteins. This cohort of proteins varies greatly in size and domain composition, possessing characteristics of Recombination hotspot (Rhs) and contact dependent growth inhibition (CDI) toxins, with similarity limited to proximal C-termini (~145 aa). This domain was named CDI-like/Rhs-like C-terminal toxin (CRCT). As such proteins are often found as toxin-antidote (TA) modules, we interrogated REIS_1423 (151 aa) as a putative antidote. Indeed, REIS_1423 is similar to proteins encoded upstream of CRCT domain-containing proteins. Accordingly, we named these proteins CDI-like/Rhs-like C-terminal toxin antidotes (CRCA). R. buchneri expressed both REIS_1423 and REIS_1424 in tick cell culture, and PCR assays showed specificity for R. buchneri over other rickettsiae and utility for positive detection in three tick populations. Finally, phylogenomics analyses uncovered divergent CRCT/CRCA modules in varying states of conservation; however, only R. buchneri and related Tamurae/Ixodes Group rickettsiae carry complete TA modules.<br><br>CONCLUSION: We hypothesize that Rickettsia CRCT/CRCA modules circulate in the Rickettsia mobile gene pool, arming rickettsiae for battle over arthropod colonization. While its functional significance remains to be tested, R. buchneri CRCT/CRCA serves as a marker to positively identify infection and begin deciphering the role this endosymbiont plays in the biology of the blacklegged tick.}, }
@article {pmid35591999, year = {2022}, author = {Guizzo, MG and Tirloni, L and Gonzalez, SA and Farber, MD and Braz, G and Parizi, LF and Dedavid E Silva, LA and da Silva Vaz, I and Oliveira, PL}, title = {Coxiella Endosymbiont of Rhipicephalus microplus Modulates Tick Physiology With a Major Impact in Blood Feeding Capacity.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {868575}, pmid = {35591999}, issn = {1664-302X}, abstract = {In the past decade, metagenomics studies exploring tick microbiota have revealed widespread interactions between bacteria and arthropods, including symbiotic interactions. Functional studies showed that obligate endosymbionts contribute to tick biology, affecting reproductive fitness and molting. Understanding the molecular basis of the interaction between ticks and their mutualist endosymbionts may help to develop control methods based on microbiome manipulation. Previously, we showed that Rhipicephalus microplus larvae with reduced levels of Coxiella endosymbiont of R. microplus (CERM) were arrested at the metanymph life stage (partially engorged nymph) and did not molt into adults. In this study, we performed a transcriptomic differential analysis of the R. microplus metanymph in the presence and absence of its mutualist endosymbiont. The lack of CERM resulted in an altered expression profile of transcripts from several functional categories. Gene products such as DA-P36, protease inhibitors, metalloproteases, and evasins, which are involved in blood feeding capacity, were underexpressed in CERM-free metanymphs. Disregulation in genes related to extracellular matrix remodeling was also observed in the absence of the symbiont. Taken together, the observed alterations in gene expression may explain the blockage of development at the metanymph stage and reveal a novel physiological aspect of the symbiont-tick-vertebrate host interaction.}, }
@article {pmid35591989, year = {2022}, author = {Wang, R and Dong, L and Chen, Y and Wang, S and Qu, L}, title = {Third Generation Genome Sequencing Reveals That Endobacteria in Nematophagous Fungi Esteya vermicola Contain Multiple Genes Encoding for Nematicidal Proteins.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {842684}, pmid = {35591989}, issn = {1664-302X}, abstract = {Esteya vermicola is the first recorded endoparasitic nematophagous fungus with high infectivity capacity, attacking the pinewood nematode Bursaphelenchus xylophilus which causes pine wilt disease. Endosymbionts are found in the cytoplasm of E. vermicola from various geographical areas. We sequenced the genome of endobacteria residing in E. vermicola to discover possible biological functions of these widespread endobacteria. Multilocus phylogenetic analyses showed that the endobacteria form a previously unidentified lineage sister to Phyllobacterium myrsinacearum species. The number of genes in the endobacterium was 4542, with 87.8% of the proteins having a known function. It contained a high proportion of repetitive sequences, as well as more Acyl-CoA synthetase genes and genes encoding the electron transport chain, compared with compared with plant-associated P. zundukense Tri 48 and P. myrsinacearum DSM 5893. Thus, this symbiotic bacterium is likely to be more efficient in regulating gene expression and energy release. Furthermore, the endobacteria in nematophagous fungi Esteya vermicola contained multiple nematicidal subtilase/subtilisin encoding genes, so it is likely that endobacteria cooperate with the host to kill nematodes.}, }
@article {pmid35591984, year = {2022}, author = {Quach, QN and Gardner, DR and Clay, K and Cook, D}, title = {Phylogenetic Patterns of Swainsonine Presence in Morning Glories.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {871148}, pmid = {35591984}, issn = {1664-302X}, abstract = {Endosymbionts play important roles in the life cycles of many macro-organisms. The indolizidine alkaloid swainsonine is produced by heritable fungi that occurs in diverse plant families, such as locoweeds (Fabaceae) and morning glories (Convolvulaceae) plus two species of Malvaceae. Swainsonine is known for its toxic effects on livestock following the ingestion of locoweeds and the potential for pharmaceutical applications. We sampled and tested herbarium seed samples (n = 983) from 244 morning glory species for the presence of swainsonine and built a phylogeny based on available internal transcribed spacer (ITS) sequences of the sampled species. We show that swainsonine occurs only in a single morning glory clade and host species are established on multiple continents. Our results further indicate that this symbiosis developed ∼5 mya and that swainsonine-positive species have larger seeds than their uninfected conspecifics.}, }
@article {pmid35588270, year = {2022}, author = {Bashir, F and Kovács, S and Ábrahám, &#xc1; and Nagy, K and Ayaydin, F and Valkony-Kelemen, I and Ferenc, G and Galajda, P and Tóth, SZ and Sass, L and Kós, PB and Vass, I and Szabó, M}, title = {Viable protoplast formation of the coral endosymbiont alga Symbiodinium spp. in a microfluidics platform.}, journal = {Lab on a chip}, volume = {22}, number = {16}, pages = {2986-2999}, doi = {10.1039/d2lc00130f}, pmid = {35588270}, issn = {1473-0189}, mesh = {Animals ; *Anthozoa/physiology ; *Dinoflagellida/physiology ; Microfluidics ; Protoplasts ; Reactive Oxygen Species ; Singlet Oxygen ; }, abstract = {Symbiodiniaceae is an important dinoflagellate family which lives in endosymbiosis with reef invertebrates, including coral polyps, making them central to the holobiont. With coral reefs currently under extreme threat from climate change, there is a pressing need to improve our understanding on the stress tolerance and stress avoidance mechanisms of Symbiodinium spp. Reactive oxygen species (ROS) such as singlet oxygen are central players in mediating various stress responses; however, the detection of ROS using specific dyes is still far from definitive in intact Symbiodinium cells due to the hindrance of uptake of certain fluorescent dyes because of the presence of the cell wall. Protoplast technology provides a promising platform for studying oxidative stress with the main advantage of removed cell wall, however the preparation of viable protoplasts remains a significant challenge. Previous studies have successfully applied cellulose-based protoplast preparation in Symbiodiniaceae; however, the protoplast formation and regeneration process was found to be suboptimal. Here, we present a microfluidics-based platform which allowed protoplast isolation from individually trapped Symbiodinium cells, by using a precisely adjusted flow of cell wall digestion enzymes (cellulase and macerozyme). Trapped single cells exhibited characteristic changes in their morphology, cessation of cell division and a slight decrease in photosynthetic activity during protoplast formation. Following digestion and transfer to regeneration medium, protoplasts remained photosynthetically active, regrew cell walls, regained motility, and entered exponential growth. Elevated flow rates in the microfluidic chambers resulted in somewhat faster protoplast formation; however, cell wall digestion at higher flow rates partially compromised photosynthetic activity. Physiologically competent protoplasts prepared from trapped cells in microfluidic chambers allowed for the first time the visualization of the intracellular localization of singlet oxygen (using Singlet Oxygen Sensor Green dye) in Symbiodiniaceae, potentially opening new avenues for studying oxidative stress.}, }
@article {pmid35587930, year = {2022}, author = {Benyedem, H and Lekired, A and Mhadhbi, M and Dhibi, M and Romdhane, R and Chaari, S and Rekik, M and Ouzari, HI and Hajji, T and Darghouth, MA}, title = {First insights into the microbiome of Tunisian Hyalomma ticks gained through next-generation sequencing with a special focus on H. scupense.}, journal = {PloS one}, volume = {17}, number = {5}, pages = {e0268172}, pmid = {35587930}, issn = {1932-6203}, mesh = {Animals ; Cattle ; *Francisella/genetics ; High-Throughput Nucleotide Sequencing ; *Ixodidae/genetics/microbiology ; *Microbiota/genetics ; RNA, Ribosomal, 16S/genetics ; *Rickettsia/genetics ; *Ticks/genetics ; }, abstract = {Ticks are one of the most important vectors of several pathogens affecting humans and animals. In addition to pathogens, ticks carry diverse microbiota of symbiotic and commensal microorganisms. In this study, we have investigated the first Tunisian insight into the microbial composition of the most dominant Hyalomma species infesting Tunisian cattle and explored the relative contribution of tick sex, life stage, and species to the diversity, richness and bacterial species of tick microbiome. In this regard, next generation sequencing for the 16S rRNA (V3-V4 region) of tick bacterial microbiota and metagenomic analysis were established. The analysis of the bacterial diversity reveals that H. marginatum and H. excavatum have greater diversity than H. scupense. Furthermore, microbial diversity and composition vary according to the tick's life stage and sex in the specific case of H. scupense. The endosymbionts Francisella, Midichloria mitochondrii, and Rickettsia were shown to be the most prevalent in Hyalomma spp. Rickettsia, Francisella, Ehrlichia, and Erwinia are the most common zoonotic bacteria found in Hyalomma ticks. Accordingly, Hyalomma ticks could represent potential vectors for these zoonotic bacterial agents.}, }
@article {pmid35581290, year = {2022}, author = {Gomes, TMFF and Wallau, GL and Loreto, ELS}, title = {Multiple long-range host shifts of major Wolbachia supergroups infecting arthropods.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {8131}, pmid = {35581290}, issn = {2045-2322}, mesh = {Animals ; *Arthropods/genetics/microbiology ; Female ; Insecta/microbiology ; Phylogeny ; *Wolbachia/genetics ; }, abstract = {Wolbachia is a genus of intracellular bacterial endosymbionts found in 20-66% of all insect species and a range of other invertebrates. It is classified as a single species, Wolbachia pipientis, divided into supergroups A to U, with supergroups A and B infecting arthropods exclusively. Wolbachia is transmitted mainly via vertical transmission through female oocytes, but can also be transmitted across different taxa by host shift (HS): the direct transmission of Wolbachia cells between organisms without involving vertically transmitted gametic cells. To assess the HS contribution, we recovered 50 orthologous genes from over 1000 Wolbachia genomes, reconstructed their phylogeny and calculated gene similarity. Of 15 supergroup A Wolbachia lineages, 10 have similarities ranging from 95 to 99.9%, while their hosts' similarities are around 60 to 80%. For supergroup B, four out of eight lineages, which infect diverse and distantly-related organisms such as Acari, Hemiptera and Diptera, showed similarities from 93 to 97%. These results show that Wolbachia genomes have a much higher similarity when compared to their hosts' genes, which is a major indicator of HS. Our comparative genomic analysis suggests that, at least for supergroups A and B, HS is more frequent than expected, occurring even between distantly-related species.}, }
@article {pmid35579457, year = {2022}, author = {Chaput, G and Ford, J and DeDiego, L and Narayanan, A and Tam, WY and Whalen, M and Huntemann, M and Clum, A and Spunde, A and Pillay, M and Palaniappan, K and Varghese, N and Mikhailova, N and Chen, IM and Stamatis, D and Reddy, TBK and O'Malley, R and Daum, C and Shapiro, N and Ivanova, N and Kyrpides, NC and Woyke, T and Glavina Del Rio, T and DeAngelis, KM}, title = {Sodalis ligni Strain 159R Isolated from an Anaerobic Lignin-Degrading Consortium.}, journal = {Microbiology spectrum}, volume = {10}, number = {3}, pages = {e0234621}, pmid = {35579457}, issn = {2165-0497}, mesh = {Anaerobiosis ; Animals ; Bacterial Typing Techniques ; DNA, Bacterial/genetics/metabolism ; *Enterobacteriaceae/genetics ; *Lignin/metabolism ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Novel bacterial isolates with the capabilities of lignin depolymerization, catabolism, or both, could be pertinent to lignocellulosic biofuel applications. In this study, we aimed to identify anaerobic bacteria that could address the economic challenges faced with microbial-mediated biotechnologies, such as the need for aeration and mixing. Using a consortium seeded from temperate forest soil and enriched under anoxic conditions with organosolv lignin as the sole carbon source, we successfully isolated a novel bacterium, designated 159R. Based on the 16S rRNA gene, the isolate belongs to the genus Sodalis in the family Bruguierivoracaceae. Whole-genome sequencing revealed a genome size of 6.38 Mbp and a GC content of 55 mol%. To resolve the phylogenetic position of 159R, its phylogeny was reconstructed using (i) 16S rRNA genes of its closest relatives, (ii) multilocus sequence analysis (MLSA) of 100 genes, (iii) 49 clusters of orthologous groups (COG) domains, and (iv) 400 conserved proteins. Isolate 159R was closely related to the deadwood associated Sodalis guild rather than the tsetse fly and other insect endosymbiont guilds. Estimated genome-sequence-based digital DNA-DNA hybridization (dDDH), genome percentage of conserved proteins (POCP), and an alignment analysis between 159R and the Sodalis clade species further supported that isolate 159R was part of the Sodalis genus and a strain of Sodalis ligni. We proposed the name Sodalis ligni str. 159R (=DSM 110549 = ATCC TSD-177). IMPORTANCE Currently, in the paper industry, paper mill pulping relies on unsustainable and costly processes to remove lignin from lignocellulosic material. A greener approach is biopulping, which uses microbes and their enzymes to break down lignin. However, there are limitations to biopulping that prevent it from outcompeting other pulping processes, such as requiring constant aeration and mixing. Anaerobic bacteria are a promising alternative source for consolidated depolymerization of lignin and its conversion to valuable by-products. We presented Sodalis ligni str. 159R and its characteristics as another example of potential mechanisms that can be developed for lignocellulosic applications.}, }
@article {pmid35573785, year = {2022}, author = {Elaagip, A and Absalon, S and Florentin, A}, title = {Apicoplast Dynamics During Plasmodium Cell Cycle.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {864819}, pmid = {35573785}, issn = {2235-2988}, mesh = {Animals ; *Apicoplasts/genetics/metabolism ; Cell Cycle ; Cell Division ; Humans ; *Malaria, Falciparum/metabolism ; *Parasites/metabolism ; *Plasmodium/metabolism ; Plasmodium falciparum/genetics ; Protozoan Proteins/genetics ; }, abstract = {The deadly malaria parasite, Plasmodium falciparum, contains a unique subcellular organelle termed the apicoplast, which is a clinically-proven antimalarial drug target. The apicoplast is a plastid with essential metabolic functions that evolved via secondary endosymbiosis. As an ancient endosymbiont, the apicoplast retained its own genome and it must be inherited by daughter cells during cell division. During the asexual replication of P. falciparum inside human red blood cells, both the parasite, and the apicoplast inside it, undergo massive morphological changes, including DNA replication and division. The apicoplast is an integral part of the cell and thus its development is tightly synchronized with the cell cycle. At the same time, certain aspects of its dynamics are independent of nuclear division, representing a degree of autonomy in organelle biogenesis. Here, we review the different aspects of organelle dynamics during P. falciparum intraerythrocytic replication, summarize our current understanding of these processes, and describe the many open questions in this area of parasite basic cell biology.}, }
@article {pmid35572673, year = {2022}, author = {Xiang, LG and Wang, HC and Wang, F and Cai, LT and Li, WH and Hsiang, T and Yu, ZH}, title = {Analysis of Phyllosphere Microorganisms and Potential Pathogens of Tobacco Leaves.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {843389}, pmid = {35572673}, issn = {1664-302X}, abstract = {In the tobacco phyllosphere, some of the microbes may have detrimental effects on plant health, while many may be neutral or even beneficial. Some cannot be cultivated, so culture-independent methods are needed to explore microbial diversity. In this study, both metagenetic analysis and traditional culture-dependent methods were used on asymptomatic healthy leaves and symptomatic diseased leaves of tobacco plants. In the culture-independent analysis, asymptomatic leaves had higher microbial diversity and richness than symptomatic leaves. Both asymptomatic and symptomatic leaves contained several potentially pathogenic bacterial and fungal genera. The putative bacterial pathogens, such as species of Pseudomonas, Pantoea, or Ralstonia, and putative fungal pathogens, such as species of Phoma, Cladosporium, Alternaria, Fusarium, Corynespora, and Epicoccum, had a higher relative abundance in symptomatic leaves than asymptomatic leaves. FUNGuild analysis indicated that the foliar fungal community also included endophytes, saprotrophs, epiphytes, parasites, and endosymbionts. PICRUSt analysis showed that the dominant functions of the bacterial community in a symptomatic leaf were cellular processes and environmental information processing. In the other five foliar samples, the dominant functions of the bacterial community were genetic information processing, metabolism, and organismal systems. In the traditional culture-dependent method, 47 fungal strains were isolated from 60 symptomatic tobacco leaf fragments bearing leaf spots. Among them, 21 strains of Colletotrichum (29%), Xylariaceae (14%), Corynespora (14%), Pestalotiopsis (10%), Alternaria (10%), Epicoccum (10%), Byssosphaeria (5%), Phoma (5%), and Diaporthe (5%) all fulfilled Koch's postulates and were found to cause disease on detached tobacco leaves in artificial inoculation tests. Symptoms on detached leaves caused by three strains of Corynespora cassiicola in artificial inoculation tests were similar to the original disease symptoms in the tobacco field. This study showed that the combined application of culture-dependent and independent methods could give comprehensive insights into microbial composition that each method alone did not reveal.}, }
@article {pmid35563511, year = {2022}, author = {Parejo, S and Cabrera, JJ and Jiménez-Leiva, A and Tomás-Gallardo, L and Bedmar, EJ and Gates, AJ and Mesa, S}, title = {Fine-Tuning Modulation of Oxidation-Mediated Posttranslational Control of Bradyrhizobium diazoefficiens FixK2 Transcription Factor.}, journal = {International journal of molecular sciences}, volume = {23}, number = {9}, pages = {}, pmid = {35563511}, issn = {1422-0067}, support = {BB/M00256X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/S008942/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Bacterial Proteins/genetics/metabolism ; *Bradyrhizobium/metabolism ; DNA/metabolism ; *Gene Expression Regulation, Bacterial ; Soybeans/genetics/metabolism ; Symbiosis ; Transcription Factors/genetics/metabolism ; }, abstract = {FixK2 is a CRP/FNR-type transcription factor that plays a central role in a sophisticated regulatory network for the anoxic, microoxic and symbiotic lifestyles of the soybean endosymbiont Bradyrhizobium diazoefficiens. Aside from the balanced expression of the fixK2 gene under microoxic conditions (induced by the two-component regulatory system FixLJ and negatively auto-repressed), FixK2 activity is posttranslationally controlled by proteolysis, and by the oxidation of a singular cysteine residue (C183) near its DNA-binding domain. To simulate the permanent oxidation of FixK2, we replaced C183 for aspartic acid. Purified C183D FixK2 protein showed both low DNA binding and in vitro transcriptional activation from the promoter of the fixNOQP operon, required for respiration under symbiosis. However, in a B. diazoefficiens strain coding for C183D FixK2, expression of a fixNOQP'-'lacZ fusion was similar to that in the wild type, when both strains were grown microoxically. The C183D FixK2 encoding strain also showed a wild-type phenotype in symbiosis with soybeans, and increased fixK2 gene expression levels and FixK2 protein abundance in cells. These two latter observations, together with the global transcriptional profile of the microoxically cultured C183D FixK2 encoding strain, suggest the existence of a finely tuned regulatory strategy to counterbalance the oxidation-mediated inactivation of FixK2 in vivo.}, }
@article {pmid35563303, year = {2022}, author = {Buerger, P and Vanstone, RT and Maire, J and van Oppen, MJH}, title = {Long-Term Heat Selection of the Coral Endosymbiont Cladocopium C1[acro] (Symbiodiniaceae) Stabilizes Associated Bacterial Communities.}, journal = {International journal of molecular sciences}, volume = {23}, number = {9}, pages = {}, pmid = {35563303}, issn = {1422-0067}, mesh = {Animals ; *Anthozoa/genetics ; Bacteria/genetics ; Coral Reefs ; *Dinoflagellida/genetics ; Hot Temperature ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Heat-tolerant strains of the coral endosymbiont, Cladocopium C1[acro] (Symbiodiniaceae), have previously been developed via experimental evolution. Here, we examine physiological responses and bacterial community composition (using 16S rRNA gene metabarcoding) in cultures of 10 heat-evolved (SS) and 9 wild-type (WT) strains, which had been exposed for 6 years to 31 °C and 27 °C, respectively. We also examine whether the associated bacterial communities were affected by a three-week reciprocal transplantation to both temperatures. The SS strains had bacterial communities with lower diversities that showed more stability and lower variability when exposed to elevated temperatures compared with the WT strains. Amplicon sequence variants (ASVs) of the bacterial genera Labrenzia, Algiphilus, Hyphobacterium and Roseitalea were significantly more associated with the SS strains compared with the WT strains. WT strains showed higher abundance of ASVs assigned to the genera Fabibacter and Tropicimonas. We hypothesize that these compositional differences in associated bacterial communities between SS and WT strains also contribute to the thermal tolerance of the microalgae. Future research should explore functional potential between bacterial communities using metagenomics to unravel specific genomic adaptations.}, }
@article {pmid35561259, year = {2022}, author = {Zhou, W and Zhang, X and Wang, A and Yang, L and Gan, Q and Yi, L and Summons, RE and Volkman, JK and Lu, Y}, title = {Widespread Sterol Methyltransferase Participates in the Biosynthesis of Both C4α- and C4β-Methyl Sterols.}, journal = {Journal of the American Chemical Society}, volume = {144}, number = {20}, pages = {9023-9032}, pmid = {35561259}, issn = {1520-5126}, mesh = {Eukaryota/metabolism ; Eukaryotic Cells/metabolism ; *Methyltransferases/metabolism ; Oxidoreductases ; *Sterols ; }, abstract = {The 4-methyl steranes serve as molecular fossils and are used for studying both eukaryotic evolution and geological history. The occurrence of 4α-methyl steranes in sediments has long been considered evidence of products of partial demethylation mediated by sterol methyl oxidases (SMOs), while 4β-methyl steranes are attributed entirely to diagenetic generation from 4α-methyl steroids since possible biological sources of their precursor 4β-methyl sterols are unknown. Here, we report a previously unknown C4-methyl sterol biosynthetic pathway involving a sterol methyltransferase rather than the SMOs. We show that both C4α- and C4β-methyl sterols are end products of the sterol biosynthetic pathway in an endosymbiont of reef corals, Breviolum minutum, while this mechanism exists not only in dinoflagellates but also in eukaryotes from alveolates, haptophytes, and aschelminthes. Our discovery provides a previously untapped route for the generation of C4-methyl steranes and overturns the paradigm that all 4β-methyl steranes are diagenetically generated from the 4α isomers. This may facilitate the interpretation of molecular fossils and understanding of the evolution of eukaryotic life in general.}, }
@article {pmid35560029, year = {2022}, author = {Thayanukul, P and Lertanantawong, B and Sirawaraporn, W and Charasmongkolcharoen, S and Chaibun, T and Jittungdee, R and Kittayapong, P}, title = {Simple, sensitive, and cost-effective detection of wAlbB Wolbachia in Aedes mosquitoes, using loop mediated isothermal amplification combined with the electrochemical biosensing method.}, journal = {PLoS neglected tropical diseases}, volume = {16}, number = {5}, pages = {e0009600}, pmid = {35560029}, issn = {1935-2735}, mesh = {*Aedes/genetics ; Animals ; *Arbovirus Infections ; Cost-Benefit Analysis ; Humans ; Molecular Diagnostic Techniques ; Mosquito Vectors ; Nucleic Acid Amplification Techniques ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Wolbachia is an endosymbiont bacterium generally found in about 40% of insects, including mosquitoes, but it is absent in Aedes aegypti which is an important vector of several arboviral diseases. The evidence that Wolbachia trans-infected Ae. aegypti mosquitoes lost their vectorial competence and became less capable of transmitting arboviruses to human hosts highlights the potential of using Wolbachia-based approaches for prevention and control of arboviral diseases. Recently, release of Wolbachia trans-infected Ae. aegypti has been deployed widely in many countries for the control of mosquito-borne viral diseases. Field surveillance and monitoring of Wolbachia presence in released mosquitoes is important for the success of these control programs. So far, a number of studies have reported the development of loop mediated isothermal amplification (LAMP) assays to detect Wolbachia in mosquitoes, but the methods still have some specificity and cost issues.<br><br>We describe here the development of a LAMP assay combined with the DNA strand displacement-based electrochemical sensor (BIOSENSOR) method to detect wAlbB Wolbachia in trans-infected Ae. aegypti. Our developed LAMP primers used a low-cost dye detecting system and 4 oligo nucleotide primers which can reduce the cost of analysis while the specificity is comparable to the previous methods. The detection capacity of our LAMP technique was 1.4 nM and the detection limit reduced to 2.2 fM when combined with the BIOSENSOR. Our study demonstrates that a BIOSENSOR can also be applied as a stand-alone method for detecting Wolbachia; and it showed high sensitivity when used with the crude DNA extracts of macerated mosquito samples without DNA purification.<br><br>CONCLUSIONS/SIGNIFICANCE: Our results suggest that both LAMP and BIOSENSOR, either used in combination or stand-alone, are robust and sensitive. The methods have good potential for routine detection of Wolbachia in mosquitoes during field surveillance and monitoring of Wolbachia-based release programs, especially in countries with limited resources.}, }
@article {pmid35548046, year = {2022}, author = {Ben Said, M and Diaz Sanchez, S and Bastos, A and Silaghi, C}, title = {Editorial: Current Knowledge on Pathogenic and Endosymbiotic Tick-Borne Bacteria.}, journal = {Frontiers in veterinary science}, volume = {9}, number = {}, pages = {900510}, doi = {10.3389/fvets.2022.900510}, pmid = {35548046}, issn = {2297-1769}, }
@article {pmid35547116, year = {2022}, author = {Weyandt, N and Aghdam, SA and Brown, AMV}, title = {Discovery of Early-Branching Wolbachia Reveals Functional Enrichment on Horizontally Transferred Genes.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {867392}, pmid = {35547116}, issn = {1664-302X}, abstract = {Wolbachia is a widespread endosymbiont of insects and filarial nematodes that profoundly influences host biology. Wolbachia has also been reported in rhizosphere hosts, where its diversity and function remain poorly characterized. The discovery that plant-parasitic nematodes (PPNs) host Wolbachia strains with unknown roles is of interest evolutionarily, ecologically, and for agriculture as a potential target for developing new biological controls. The goal of this study was to screen communities for PPN endosymbionts and analyze genes and genomic patterns that might indicate their role. Genome assemblies revealed 1 out of 16 sampled sites had nematode communities hosting a Wolbachia strain, designated wTex, that has highly diverged as one of the early supergroup L strains. Genome features, gene repertoires, and absence of known genes for cytoplasmic incompatibility, riboflavin, biotin, and other biosynthetic functions placed wTex between mutualist C + D strains and reproductive parasite A + B strains. Functional terms enriched in group L included protoporphyrinogen IX, thiamine, lysine, fatty acid, and cellular amino acid biosynthesis, while dN/dS analysis suggested the strongest purifying selection on arginine and lysine metabolism, and vitamin B6, heme, and zinc ion binding, suggesting these as candidate roles in PPN Wolbachia. Higher dN/dS pathways between group L, wPni from aphids, wFol from springtails, and wCfeT from cat fleas suggested distinct functional changes characterizing these early Wolbachia host transitions. PPN Wolbachia had several putative horizontally transferred genes, including a lysine biosynthesis operon like that of the mitochondrial symbiont Midichloria, a spirochete-like thiamine synthesis operon shared only with wCfeT, an ATP/ADP carrier important in Rickettsia, and a eukaryote-like gene that may mediate plant systemic acquired resistance through the lysine-to-pipecolic acid system. The Discovery of group L-like variants from global rhizosphere databases suggests diverse PPN Wolbachia strains remain to be discovered. These findings support the hypothesis of plant-specialization as key to shaping early Wolbachia evolution and present new functional hypotheses, demonstrating promise for future genomics-based rhizosphere screens.}, }
@article {pmid35532932, year = {2022}, author = {Strunov, A and Lerch, S and Blanckenhorn, WU and Miller, WJ and Kapun, M}, title = {Complex effects of environment and Wolbachia infections on the life history of Drosophila melanogaster hosts.}, journal = {Journal of evolutionary biology}, volume = {35}, number = {6}, pages = {788-802}, pmid = {35532932}, issn = {1420-9101}, mesh = {Animals ; Drosophila melanogaster/genetics ; Female ; Fertility ; Longevity ; Male ; Reproduction ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Wolbachia bacteria are common endosymbionts of many arthropods found in gonads and various somatic tissues. They manipulate host reproduction to enhance their transmission and confer complex effects on fitness-related traits. Some of these effects can serve to increase the survival and transmission efficiency of Wolbachia in the host population. The Wolbachia-Drosophila melanogaster system represents a powerful model to study the evolutionary dynamics of host-microbe interactions and infections. Over the past decades, there has been a replacement of the ancestral wMelCS Wolbachia variant by the more recent wMel variant in worldwide D. melanogaster populations, but the reasons remain unknown. To investigate how environmental change and genetic variation of the symbiont affect host developmental and adult life-history traits, we compared effects of both Wolbachia variants and uninfected controls in wild-caught D. melanogaster strains at three developmental temperatures. While Wolbachia did not influence any developmental life-history traits, we found that both lifespan and fecundity of host females were increased without apparent fitness trade-offs. Interestingly, wMelCS-infected flies were more fecund than uninfected and wMel-infected flies. By contrast, males infected with wMel died sooner, indicating sex-specific effects of infection that are specific to the Wolbachia variant. Our study uncovered complex temperature-specific effects of Wolbachia infections, which suggests that symbiont-host interactions in nature are strongly dependent on the genotypes of both partners and the thermal environment.}, }
@article {pmid35526060, year = {2022}, author = {Hildebrand, J and Perec-Matysiak, A and Popiołek, M and Merta, D and Myśliwy, I and Buńkowska-Gawlik, K}, title = {A molecular survey of spotted fever group rickettsiae in introduced raccoons (Procyon lotor).}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {162}, pmid = {35526060}, issn = {1756-3305}, mesh = {Animals ; Bayes Theorem ; Phylogeny ; Raccoons ; *Rickettsia ; *Spotted Fever Group Rickettsiosis ; *Ticks ; }, abstract = {BACKGROUND: The raccoon Procyon lotor (Linnaeus, 1758) (Carnivora; Procyonidae) is one of the most important and most intensively studied invasive mammal species in Europe. Within the last 30 years the raccoon has spread at an increasing rate, resulting in the establishment of local populations in various regions of Europe. In these newly colonised areas, gaps in knowledge of the raccoon's biology concern not only most aspects of its ecology in a broad sense, but also its pathogens and parasites. Most micropathogens recorded hitherto in the raccoons that have colonised Europe have documented epizootic and zoonotic potential. Thus, it is considered especially important to investigate the role played by the raccoon in the spread of pathogens through both animal-animal and animal-human pathways.<br><br>METHODS: Tissue samples of raccoons from Poland and Germany were examined in this study. In total, 384 tissue samples from 220 raccoons (170 spleen samples, 82 liver biopsies, 132 ear biopsies) were examined using molecular methods. The presence of Rickettsia spp. DNA was screened through amplification of a fragment of the gltA gene. Samples that were PCR positive for gltA were tested for other rickettsial genes, ompB and a 17-kDa antigen. For taxonomic purposes, the obtained sequences were compared with corresponding sequences deposited in GenBank using the Basic Local Alignment Search Tool, and phylogenetic analyses were conducted using Bayesian inference implemented in MrBayes software.<br><br>RESULTS: Rickettsia DNA was confirmed only in skin biopsies; no isolates from the spleen or liver were positive for Rickettsia DNA. With the exception of one sample from Germany, which was positive for Rickettsia helvetica DNA, all the samples positive for Rickettsia DNA derived from the Polish population of raccoons. DNA of Rickettsia spp. was detected in 25 samples, i.e. 11.4% of the tested raccoons, and R. helvetica was confirmed in 52% of the positive samples. Additionally, single cases of Rickettsia monacensis, Rickettsia raoultii, and Candidatus Rickettsia kotlanii-like were found, and in 32% of all the positive samples similarity was shown to different Rickettsia endosymbionts. Out of the samples that tested positive for gltA, amplicons of ompB and 17&#xa0;kDa were successfully sequenced from 14 and three samples, respectively.<br><br>CONCLUSIONS: To the best of our knowledge, this study provides, for the first time, evidence of the occurrence of Rickettsia pathogens and endosymbionts in the European population of raccoons. Further, broader research on different species of wild vertebrates, and ticks, as potential vectors and hosts for tick-borne pathogens, in natural as well as in peri-urban environments, is therefore required.}, }
@article {pmid35521555, year = {2022}, author = {Moustafa, MAM and Mohamed, WMA and Lau, ACC and Chatanga, E and Qiu, Y and Hayashi, N and Naguib, D and Sato, K and Takano, A and Matsuno, K and Nonaka, N and Taylor, D and Kawabata, H and Nakao, R}, title = {Novel symbionts and potential human pathogens excavated from argasid tick microbiomes that are shaped by dual or single symbiosis.}, journal = {Computational and structural biotechnology journal}, volume = {20}, number = {}, pages = {1979-1992}, pmid = {35521555}, issn = {2001-0370}, abstract = {Research on vector-associated microbiomes has been expanding due to increasing emergence of vector-borne pathogens and awareness of the importance of symbionts in the vector physiology. However, little is known about microbiomes of argasid (or soft-bodied) ticks due to limited access to specimens. We collected four argasid species (Argas japonicus, Carios vespertilionis, Ornithodoros capensis, and Ornithodoros sawaii) from the nests or burrows of their vertebrate hosts. One laboratory-reared argasid species (Ornithodoros moubata) was also included. Attempts were then made to isolate and characterize potential symbionts/pathogens using arthropod cell lines. Microbial community structure was distinct for each tick species. Coxiella was detected as the predominant symbiont in four tick species where dual symbiosis between Coxiella and Rickettsia or Coxiella and Francisella was observed in C. vespertilionis and O. moubata, respectively. Of note, A. japonicus lacked Coxiella and instead had Occidentia massiliensis and Thiotrichales as alternative symbionts. Our study found strong correlation between tick species and life stage. We successfully isolated Oc. massiliensis and characterized potential pathogens of genera Ehrlichia and Borrelia. The results suggest that there is no consistent trend of microbiomes in relation to tick life stage that fit all tick species and that the final interpretation should be related to the balance between environmental bacterial exposure and endosymbiont ecology. Nevertheless, our findings provide insights on the ecology of tick microbiomes and basis for future investigations on the capacity of argasid ticks to carry novel pathogens with public health importance.}, }
@article {pmid35517715, year = {2022}, author = {Kačar, D and Schleissner, C and Cañedo, LM and Rodríguez, P and de la Calle, F and Cuevas, C and Galán, B and García, JL}, title = {In vivo production of pederin by labrenzin pathway expansion.}, journal = {Metabolic engineering communications}, volume = {14}, number = {}, pages = {e00198}, pmid = {35517715}, issn = {2214-0301}, abstract = {Pederin is a potent polyketide toxin that causes severe skin lesions in humans after contact with insects of genus Paederus. Due to its potent anticancer activities, pederin family compounds have raised the interest of pharmaceutical industry. Despite the extensive studies on the cluster of biosynthetic genes responsible for the production of pederin, it has not yet been possible to isolate and cultivate its bacterial endosymbiont producer. However, the marine bacterium Labrenzia sp. PHM005 was recently reported to produce labrenzin, the closest pederin analog. By cloning a synthetic pedO gene encoding one of the three O-methyltraferase of the pederin cluster into Labrenzia sp. PHM005 we have been able to produce pederin for the first time by fermentation in the new recombinant strain.}, }
@article {pmid35508975, year = {2022}, author = {Johnson, JV and Dick, JTA and Pincheira-Donoso, D}, title = {Marine protected areas do not buffer corals from bleaching under global warming.}, journal = {BMC ecology and evolution}, volume = {22}, number = {1}, pages = {58}, pmid = {35508975}, issn = {2730-7182}, mesh = {Animals ; *Anthozoa ; Bayes Theorem ; Coral Reefs ; Ecosystem ; Global Warming/prevention &amp; control ; }, abstract = {BACKGROUND: The rising temperature of the oceans has been identified as the primary driver of mass coral reef declines via coral bleaching (expulsion of photosynthetic endosymbionts). Marine protected areas (MPAs) have been implemented throughout the oceans with the aim of mitigating the impact of local stressors, enhancing fish biomass, and sustaining biodiversity overall. In coral reef regions specifically, protection from local stressors and the enhanced ecosystem function contributed by MPAs are expected to increase coral resistance to global-scale stressors such as marine heatwaves. However, MPAs still suffer from limitations in design, or fail to be adequately enforced, potentially reducing their intended efficacy. Here, we address the hypothesis that the local-scale benefits resulting from MPAs moderate coral bleaching under global warming related stress.<br><br>RESULTS: Bayesian analyses reveal that bleaching is expected to occur in both larger and older MPAs when corals are under thermal stress from marine heatwaves (quantified as Degree Heating Weeks, DHW), but this is partially moderated in comparison to the effects of DHW alone. Further analyses failed to identify differences in bleaching prevalence in MPAs relative to non-MPAs for coral reefs experiencing different levels of thermal stress. Finally, no difference in temperatures where bleaching occurs between MPA and non-MPA sites was found.<br><br>CONCLUSIONS: Our findings suggest that bleaching is likely to occur under global warming regardless of protected status. Thus, while protected areas have key roles for maintaining ecosystem function and local livelihoods, combatting the source of global warming remains the best way to prevent the decline of coral reefs via coral bleaching.}, }
@article {pmid35503212, year = {2022}, author = {Scott, H and Davies, GJ and Armstrong, Z}, title = {The structure of Phocaeicola vulgatus sialic acid acetylesterase.}, journal = {Acta crystallographica. Section D, Structural biology}, volume = {78}, number = {Pt 5}, pages = {647-657}, pmid = {35503212}, issn = {2059-7983}, support = {BB/R001162/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Acetylation ; *Acetylesterase/chemistry/metabolism ; Bacteria/metabolism ; Bacteroides ; Carboxylic Ester Hydrolases ; Humans ; *N-Acetylneuraminic Acid/metabolism ; Sialic Acids/metabolism ; }, abstract = {Sialic acids terminate many N- and O-glycans and are widely distributed on cell surfaces. There are a diverse range of enzymes which interact with these sugars throughout the tree of life. They can act as receptors for influenza and specific betacoronaviruses in viral binding and their cleavage is important in virion release. Sialic acids are also exploited by both commensal and pathogenic bacteria for nutrient acquisition. A common modification of sialic acid is 9-O-acetylation, which can limit the action of sialidases. Some bacteria, including human endosymbionts, employ esterases to overcome this modification. However, few bacterial sialic acid 9-O-acetylesterases (9-O-SAEs) have been structurally characterized. Here, the crystal structure of a 9-O-SAE from Phocaeicola vulgatus (PvSAE) is reported. The structure of PvSAE was determined to resolutions of 1.44 and 2.06 Å using crystals from two different crystallization conditions. Structural characterization revealed PvSAE to be a dimer with an SGNH fold, named after the conserved sequence motif of this family, and a Ser-His-Asp catalytic triad. These structures also reveal flexibility in the most N-terminal α-helix, which provides a barrier to active-site accessibility. Biochemical assays also show that PvSAE deacetylates both mucin and the acetylated chromophore para-nitrophenyl acetate. This structural and biochemical characterization of PvSAE furthers the understanding of 9-O-SAEs and may aid in the discovery of small molecules targeting this class of enzyme.}, }
@article {pmid35499324, year = {2022}, author = {Yang, Q and Cahn, JKB and Piel, J and Song, YF and Zhang, W and Lin, HW}, title = {Marine Sponge Endosymbionts: Structural and Functional Specificity of the Microbiome within Euryspongia arenaria Cells.}, journal = {Microbiology spectrum}, volume = {10}, number = {3}, pages = {e0229621}, pmid = {35499324}, issn = {2165-0497}, mesh = {Animals ; Lipase/genetics ; *Microbiota ; Phylogeny ; *Porifera/genetics/microbiology ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Sponge microbiomes are typically profiled by analyzing the community DNA of whole tissues, which does not distinguish the taxa residing within sponge cells from extracellular microbes. To uncover the endosymbiotic microbiome, we separated the sponge cells to enrich the intracellular microbes. The intracellular bacterial community of sponge Euryspongia arenaria was initially assessed by amplicon sequencing, which indicated that it hosts three unique phyla not found in the extracellular and bulk tissue microbiomes. These three phyla account for 66% of the taxonomically known genera in the intracellular microbiome. The shotgun metagenomic analysis extended the taxonomic coverage to viruses and eukaryotes, revealing the most abundant signature taxa specific to the intracellular microbiome. Functional KEGG pathway annotation demonstrated that the endosymbiotic microbiome hosted the greatest number of unique gene orthologs. The pathway profiles distinguished the intra- and extracellular microbiomes from the tissue and seawater microbiomes. Carbohydrate-active enzyme analysis further discriminated each microbiome based on their representative and dominant enzyme families. One pathway involved in digestion system and family esterase had a consistently higher level in intracellular microbiome and could statistically differentiate the intracellular microbiome from the others, suggesting that triacylglycerol lipases could be the key functional component peculiar to the endosymbionts. The identified higher abundance of lipase-related eggNOG categories further supported the lipid-hydrolyzing metabolism of endosymbiotic microbiota. Pseudomonas members, reported as lipase-producing bacteria, were only in the endosymbiotic microbiome, meanwhile Pseudomonas also showed a greater abundance intracellularly. Our study aided a comprehensive sponge microbiome that demonstrated the taxonomic and functional specificity of endosymbiotic microbiota. IMPORTANCE Sponges host abundant microbial symbionts that can produce an impressive number of novel bioactive metabolites. However, knowledge on intracellular (endosymbiotic) microbiota is scarce. We characterize the composition and function of the endosymbiotic microbiome by separation of sponge cells and enrichment of intracellular microbes. We uncover a noteworthy number of taxa exclusively in the endosymbiotic microbiome. We unlock the unique pathways and enzymes of endosymbiotic taxa. This study achieves a more comprehensive sponge microbial community profile, which demonstrates the structural and functional specificity of the endosymbiotic microbiome. Our findings not only open the possibility to reveal the low abundant and the likely missed microbiota when directly sequencing the sponge bulk tissues, but also warrant future in-depth exploration within single sponge cells.}, }
@article {pmid35495648, year = {2022}, author = {Rataj, M and Zhang, T and Vd'ačný, P}, title = {Nuclear and Mitochondrial SSU rRNA Genes Reveal Hidden Diversity of Haptophrya Endosymbionts in Freshwater Planarians and Challenge Their Traditional Classification in Astomatia.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {830951}, pmid = {35495648}, issn = {1664-302X}, abstract = {Like many other aquatic animals, freshwater planarians have also become partners of symbiotic ciliates from the class Oligohymenophorea. In the present study, we explored the hidden diversity and addressed the questionable systematic position of mouthless obligatory gut endosymbionts of freshwater planarians, using the nuclear and mitochondrial SSU rRNA genes. Although all isolated ciliates morphologically corresponded to a single species, molecular analyses suggested the existence of three genetically distinct entities: Haptophrya planariarum, Haptophrya dugesiarum nov. spec., and Haptophrya schmidtearum nov. spec. The two former species share the same planarian host, which indicates a speciation model involving one duplication event without host switching. Such a diversification pattern was recognized also in astome ciliates inhabiting megascolecid and glossoscolecid earthworms. The present multi-gene phylogenies along with the secondary structure of the mitochondrial 16S rRNA molecule, however, challenge the traditional classification of Haptophrya within the subclass Astomatia. Haptophrya very likely evolved from an orphan scuticociliate lineage by the loss of oral apparatus and by the transformation of the thigmotactic field into an adhesive sucker. Since astomy evolved multiple times independently within the Oligohymenophorea, the loss of cell mouth cannot be used as a sole argument for the assignment of Haptophrya to the Astomatia anymore.}, }
@article {pmid35493735, year = {2022}, author = {Kumar, D and Sharma, SR and Adegoke, A and Kennedy, A and Tuten, HC and Li, AY and Karim, S}, title = {Recently Evolved Francisella-Like Endosymbiont Outcompetes an Ancient and Evolutionarily Associated Coxiella-Like Endosymbiont in the Lone Star Tick (Amblyomma americanum) Linked to the Alpha-Gal Syndrome.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {787209}, pmid = {35493735}, issn = {2235-2988}, mesh = {Amblyomma ; Animals ; Bacteria ; Coxiella ; *Food Hypersensitivity ; *Francisella/genetics ; Humans ; *Ticks/microbiology ; United States ; }, abstract = {BACKGROUND: Ticks are hematophagous arthropods that transmit various bacterial, viral, and protozoan pathogens of public health significance. The lone star tick (Amblyomma americanum) is an aggressive human-biting tick that transmits bacterial and viral pathogens, and its bites are suspected of eliciting the alpha-gal syndrome, a newly emerged delayed hypersensitivity following consumption of red meat in the United States. While ongoing studies have attempted to investigate the contribution of different tick-inherent factors to the induction of alpha-gal syndrome, an otherwise understudied aspect is the contribution of the tick microbiome and specifically obligate endosymbionts to the establishment of the alpha-gal syndrome in humans.<br><br>MATERIALS AND METHODS: Here we utilized a high-throughput metagenomic sequencing approach to cataloging the entire microbial communities residing within different developmental stages and tissues of unfed and blood-fed ticks from laboratory-maintained ticks and three new geographical locations in the United States. The Quantitative Insights Into Microbial Ecology (QIIME2) pipeline was used to perform data analysis and taxonomic classification. Moreover, using a SparCC (Sparse Correlations for Compositional data) network construction model, we investigated potential interactions between members of the microbial communities from laboratory-maintained and field-collected ticks.<br><br>RESULTS: Overall, Francisellaceae was the most dominant bacteria identified in the microbiome of both laboratory-raised and field-collected Am. americanum across all tissues and developmental stages. Likewise, microbial diversity was seen to be significantly higher in field-collected ticks compared with laboratory-maintained ticks as seen with a higher number of both Operational Taxonomic Units and measures of species richness. Several potential positive and negative correlations were identified from our network analysis. We observed a strong positive correlation between Francisellaceae, Rickettsiaceae, and Midichloriaceae in both developmental stages and tissues from laboratory-maintained ticks, whereas ovarian tissues had a strong positive correlation of bacteria in the family Xanthobacteraceae and Rhizobiaceae. A negative interaction was observed between Coxiellaceae and Francisellaceae in Illinois, and all the bacteria detected from ticks from Delaware were negatively correlated.<br><br>CONCLUSION: This study is the first to catalog the microbiome of Am. americanum throughout its developmental stages and different tissue niches and report the potential replacement of Coxiellaceae by Francisellaceae across developmental stages and tissues tested except in ovarian tissues. These unique and significant findings advance our knowledge and open a new avenue of research to further understand the role of tick microbiome in tick-borne diseases and develop a holistic strategy to control alpha-gal syndrome.}, }
@article {pmid35490549, year = {2022}, author = {Noden, BH and Henriquez, BE and Roselli, MA and Loss, SR}, title = {Use of an exclusion assay to detect novel rickettsiae in field collected Amblyomma americanum.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {4}, pages = {101959}, doi = {10.1016/j.ttbdis.2022.101959}, pmid = {35490549}, issn = {1877-9603}, mesh = {Amblyomma ; Animals ; Canada ; Dogs ; Humans ; *Ixodidae/microbiology ; Oklahoma/epidemiology ; *Rickettsia ; *Ticks ; }, abstract = {In the south-central United States, several tick-borne diseases (TbDs) occur at or near their highest levels of incidence of anywhere in the U.S. The diversity of Rickettsia species found in Amblyomma americanum continues to be under-characterized in this region and throughout the U.S. and Canada where this tick species is expanding. One reason for this lack of knowledge about Rickettsia diversity is the high prevalence of the endosymbiont Rickettsia amblyommatis that obscures detection of other bacteria in this genus. Focusing on unknown rickettsial agents, we used a recently described R. amblyommatis exclusion assay to screen 1909 A. americanum collected in Oklahoma City, Oklahoma, which resulted in eight ticks that had unique rickettsial sequences. Through the process of characterizing primary and secondary rickettsiae, we identified ticks primarily infected with Rickettsia rhipicephali and a Rickettsia species (2019-CO-FNY) previously linked with a canine rickettsiosis case in Tulsa, Oklahoma. We also identified a Rickettsia agent that was 97% identical with an endosymbiont of Amblyomma tonelliae and which aligned with archaic rickettsial species. Through this study, we further demonstrate the usefulness of this exclusion assay for rapid screening in large cohort A. americanum studies to identify a small number of ticks that contain poorly described and previously undocumented rickettsiae.}, }
@article {pmid35486255, year = {2022}, author = {Oortwijn, T and de Fouw, J and Petersen, JM and van Gils, JA}, title = {Sulfur in lucinid bivalves inhibits intake rates of a molluscivore shorebird.}, journal = {Oecologia}, volume = {199}, number = {1}, pages = {69-78}, pmid = {35486255}, issn = {1432-1939}, mesh = {Animals ; *Bivalvia ; *Charadriiformes ; Ecosystem ; Sulfides ; Sulfur ; }, abstract = {A forager's energy intake rate is usually constrained by a combination of handling time, encounter rate and digestion rate. On top of that, food intake may be constrained when a forager can only process a maximum amount of certain toxic compounds. The latter constraint is well described for herbivores with a limited tolerance to plant secondary metabolites. In sulfidic marine ecosystems, many animals host chemoautotrophic endosymbionts, which store sulfur compounds as an energy resource, potentially making their hosts toxic to predators. The red knot Calidris canutus canutus is a molluscivore shorebird that winters on the mudflats of Banc d'Arguin, where the most abundant bivalve prey Loripes orbiculatus hosts sulfide-oxidizing bacteria. In this system, we studied the potential effect of sulfur on the red knots' intake rates, by offering Loripes with various sulfur content to captive birds. To manipulate toxicity, we starved Loripes for 10 days by removing them from their symbiont's energy source sulfide. As predicted, we found lower sulfur concentrations in starved Loripes. We also included natural variation in sulfur concentrations by offering Loripes collected at two different locations. In both cases lower sulfur levels in Loripes resulted in higher consumption rates in red knots. Over time the red knots increased their intake rates on Loripes, showing their ability to adjust to a higher intake of sulfur.}, }
@article {pmid35485184, year = {2022}, author = {Kaur, R and Singh, S and Joshi, N}, title = {Pervasive Endosymbiont Arsenophonus Plays a Key Role in the Transmission of Cotton Leaf Curl Virus Vectored by Asia II-1 Genetic Group of Bemisia tabaci.}, journal = {Environmental entomology}, volume = {51}, number = {3}, pages = {564-577}, doi = {10.1093/ee/nvac024}, pmid = {35485184}, issn = {1938-2936}, mesh = {Animals ; Anti-Bacterial Agents ; Asia ; *Hemiptera/genetics ; *Rifampin/pharmacology ; Symbiosis ; Tetracyclines ; }, abstract = {Insects often coevolved with their mutualistic partners such as gut endosymbionts, which play a key in the physiology of host. Studies on such interactions between Bemisia tabaci and its primary and secondary endosymbionts have gained importance due to their indispensable roles in the biology of this insect. Present study reports the predominance of two secondary endosymbionts, Arsenophonus and Cardinium in the Asia II-1 genetic group of whitefly and elucidates their role in the transmission of its vectored Cotton leaf curl virus. Selective elimination of endosymbionts was optimized using serial concentration of ampicillin, chloramphenicol, kanamycin, tetracycline, and rifampicin administered to viruliferous whiteflies through sucrose diet. Primary endosymbiont, Portiera was unresponsive to all the antibiotics, however, rifampicin and tetracycline at 90 μg/ml selectively eliminated Arsenophonus from the whitefly. Elimination of Arsenophonus resulted in significant decrease in virus titer from viruliferous whitefly, further the CLCuV transmission efficiency of these whiteflies was significantly reduced compared to the control flies. Secondary endosymbiont, Cardinium could not be eliminated completely even with higher concentrations of antibiotics. Based on the findings, Arsenophonus plays a key role in the retention and transmission of CLCuV in the Asia II-1 genetic group of B. tabaci, while the role of Cardinium could not be established due to its unresponsiveness to antibiotics.}, }
@article {pmid35479634, year = {2022}, author = {Garzón, MJ and Reyes-Prieto, M and Gil, R}, title = {The Minimal Translation Machinery: What We Can Learn From Naturally and Experimentally Reduced Genomes.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {858983}, pmid = {35479634}, issn = {1664-302X}, abstract = {The current theoretical proposals of minimal genomes have not attempted to outline the essential machinery for proper translation in cells. Here, we present a proposal of a minimal translation machinery based on (1) a comparative analysis of bacterial genomes of insects' endosymbionts using a machine learning classification algorithm, (2) the empiric genomic information obtained from Mycoplasma mycoides JCVI-syn3.0 the first minimal bacterial genome obtained by design and synthesis, and (3) a detailed functional analysis of the candidate genes based on essentiality according to the DEG database (Escherichia coli and Bacillus subtilis) and the literature. This proposed minimal translational machinery is composed by 142 genes which must be present in any synthetic prokaryotic cell designed for biotechnological purposes, 76.8% of which are shared with JCVI-syn3.0. Eight additional genes were manually included in the proposal for a proper and efficient translation.}, }
@article {pmid35474066, year = {2022}, author = {Cournoyer, JE and Altman, SD and Gao, YL and Wallace, CL and Zhang, D and Lo, GH and Haskin, NT and Mehta, AP}, title = {Engineering artificial photosynthetic life-forms through endosymbiosis.}, journal = {Nature communications}, volume = {13}, number = {1}, pages = {2254}, pmid = {35474066}, issn = {2041-1723}, support = {R01 GM139949/GM/NIGMS NIH HHS/United States ; }, mesh = {Biological Evolution ; Chloroplasts/genetics ; *Cyanobacteria/genetics ; Photosynthesis/genetics ; Saccharomyces cerevisiae ; *Symbiosis/genetics ; }, abstract = {The evolutionary origin of the photosynthetic eukaryotes drastically altered the evolution of complex lifeforms and impacted global ecology. The endosymbiotic theory suggests that photosynthetic eukaryotes evolved due to endosymbiosis between non-photosynthetic eukaryotic host cells and photosynthetic cyanobacterial or algal endosymbionts. The photosynthetic endosymbionts, propagating within the cytoplasm of the host cells, evolved, and eventually transformed into chloroplasts. Despite the fundamental importance of this evolutionary event, we have minimal understanding of this remarkable evolutionary transformation. Here, we design and engineer artificial, genetically tractable, photosynthetic endosymbiosis between photosynthetic cyanobacteria and budding yeasts. We engineer various mutants of model photosynthetic cyanobacteria as endosymbionts within yeast cells where, the engineered cyanobacteria perform bioenergetic functions to support the growth of yeast cells under defined photosynthetic conditions. We anticipate that these genetically tractable endosymbiotic platforms can be used for evolutionary studies, particularly related to organelle evolution, and also for synthetic biology applications.}, }
@article {pmid35446252, year = {2022}, author = {Quek, S and Cerdeira, L and Jeffries, CL and Tomlinson, S and Walker, T and Hughes, GL and Heinz, E}, title = {Wolbachia endosymbionts in two Anopheles species indicates independent acquisitions and lack of prophage elements.}, journal = {Microbial genomics}, volume = {8}, number = {4}, pages = {}, pmid = {35446252}, issn = {2057-5858}, support = {BB/V011278/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 217303/Z/19/Z/WT_/Wellcome Trust/United Kingdom ; 101285/WT_/Wellcome Trust/United Kingdom ; BB/T001240/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; R01 AI116811/AI/NIAID NIH HHS/United States ; R21 AI138074/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Anopheles ; Prophages/genetics ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Wolbachia is a genus of obligate bacterial endosymbionts that infect a diverse range of arthropod species as well as filarial nematodes, with its single described species, Wolbachia pipientis , divided into several ‘supergroups’ based on multilocus sequence typing. Wolbachia strains in mosquitoes have been shown to inhibit the transmission of human pathogens, including Plasmodium malaria parasites and arboviruses. Despite their large host range, Wolbachia strains within the major malaria vectors of the Anopheles gambiae and Anopheles funestus complexes appear at low density, established solely on PCR-based methods. Questions have been raised as to whether this represents a true endosymbiotic relationship. However, recent definitive evidence for two distinct, high-density strains of supergroup B Wolbachia within Anopheles demeilloni and Anopheles moucheti has opened exciting possibilities to explore naturally occurring Wolbachia endosymbionts in Anopheles for biocontrol strategies to block Plasmodium transmission. Here, we utilize genomic analyses to demonstrate that both Wolbachia strains have retained all key metabolic and transport pathways despite their smaller genome size, with this reduction potentially attributable to degenerated prophage regions. Even with this reduction, we confirmed the presence of cytoplasmic incompatibility (CI) factor genes within both strains, with wAnD maintaining intact copies of these genes while the cifB gene was interrupted in wAnM, so functional analysis is required to determine whether wAnM can induce CI. Additionally, phylogenetic analysis indicates that these Wolbachia strains may have been introduced into these two Anopheles species via horizontal transmission events, rather than by ancestral acquisition and subsequent loss events in the Anopheles gambiae species complex. These are the first Wolbachia genomes, to our knowledge, that enable us to study the relationship between natural strain Plasmodium malaria parasites and their anopheline hosts.}, }
@article {pmid35445372, year = {2022}, author = {Patra, G and Ghosh, S and Polley, S and Priyanka,  and Borthakur, SK and Choudhary, OP and Arya, RS}, title = {Molecular detection and genetic characterization of Coxiella-like endosymbionts in dogs and ticks infesting dogs in Northeast India.}, journal = {Experimental &amp; applied acarology}, volume = {86}, number = {4}, pages = {549-566}, pmid = {35445372}, issn = {1572-9702}, mesh = {Animals ; Coxiella/genetics ; DNA, Bacterial/genetics ; Dogs ; Female ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Rhipicephalus/genetics ; *Rhipicephalus sanguineus/genetics ; Superoxide Dismutase/genetics ; }, abstract = {An epidemiological study was performed to determine the role of dogs and ticks infesting dogs in the transmission of Q fever in humans and animals from April 2019 to March 2020 in the northeastern hill states of India. In total, 245 pet and stray dogs irrespective of age or sex were sampled, without specific inclusion or exclusion criteria. In total, 478 ticks belonging to three species were detected, namely Rhipicephalus sanguineus, Rhipicephalus (Boophilus) microplus and Hyalomma anatolicum anatolicum. The DNA extracted from blood and tick samples was assayed for molecular characterization of Coxiella burnetii targeting the 16S rRNA and superoxide dismutase (SOD) genes. Amplified PCR products were purified, cloned and custom sequenced. PCR assay showed 3.3% (8/245) of the dogs were positive for Coxiella-like bacteria. Coxiella-like bacterial DNA was detected in adult fully engorged females of R. sanguineus (7.7%, 13/168), R. (B.) microplus (3.3%, 4/123) and H. anatolicum (1.9%, 1/54). Coxiella-like bacterial DNA lacked in adult male or nymphal stage. The infection rate did not vary significantly between seasons, nor according to sex or age of the host. Six nucleotide sequences of 16S rRNA and SOD genes are discussed.}, }
@article {pmid35437949, year = {2022}, author = {Zhou, JC and Shang, D and Qian, Q and Zhang, C and Zhang, LS and Dong, H}, title = {Penetrance during Wolbachia-mediated parthenogenesis of Trichogramma wasps is reduced by continuous oviposition, associated with exhaustion of Wolbachia titers in ovary and offspring eggs.}, journal = {Pest management science}, volume = {78}, number = {7}, pages = {3080-3089}, doi = {10.1002/ps.6934}, pmid = {35437949}, issn = {1526-4998}, mesh = {Animals ; Female ; In Situ Hybridization, Fluorescence ; Ovary ; Oviposition ; Parthenogenesis ; Penetrance ; *Wasps/genetics ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Thelytokous Wolbachia-infected Trichogramma wasps are superior to bisexual uninfected wasps regarding biological control programs. However, continuous oviposition weakens the parthenogenesis-inducing (PI) strength of Wolbachia. Whether this reduced PI strength relates to decreases in the titer of Wolbachia in the ovary and offspring eggs of Trichogramma remains unclear. Here, using fluorescence in situ hybridization (FISH) and reverse transcription quantitative polymerase chain reaction (RT-qPCR) methods, we investigated how the penetrance of Wolbachia-mediated parthenogenesis, Wolbachia density, and distributions of two Wolbachia-infected Trichogramma species, T. pretiosum (TP) and T. dendrolimi (TD), were influenced by different host access treatments [newly-emerged virgin females (NE), 7-day-old females without access to host eggs (NAH), and 7-day-old virgin females with access to host eggs (AH)].<br><br>RESULTS: Continuous oviposition decreased Wolbachia PI strength and titers in TP and TD. Continuous oviposition in AH decreased Wolbachia titers in abdomen and offspring eggs of TP and TD females, compared with NAH and NE; NAH had a lower thorax Wolbachia titer than NE. The numbers of parasitized host eggs and offspring wasps, and emergence rates of offspring deposited by AH were lower than those of NE and NAH, for either species.<br><br>CONCLUSION: Weakened PI strength, driven by continuous oviposition in Trichogramma wasps, is associated with Wolbachia titer exhaustion in ovary and offspring eggs. Wolbachia density is dependent on PI strength in Trichogramma wasps, highlighting the side effects of continuous oviposition regarding thelytokous Wolbachia-infected Trichogramma in biological control programs. &#xa9; 2022 Society of Chemical Industry.}, }
@article {pmid35432921, year = {2022}, author = {Darwell, CT and Souto-Vilarós, D and Michalek, J and Boutsi, S and Isua, B and Sisol, M and Kuyaiva, T and Weiblen, G and Křivan, V and Novotny, V and Segar, ST}, title = {Predicting distributions of Wolbachia strains through host ecological contact-Who's manipulating whom?.}, journal = {Ecology and evolution}, volume = {12}, number = {4}, pages = {e8826}, pmid = {35432921}, issn = {2045-7758}, abstract = {Reproductive isolation in response to divergent selection is often mediated via third-party interactions. Under these conditions, speciation is inextricably linked to ecological context. We present a novel framework for understanding arthropod speciation as mediated by Wolbachia, a microbial endosymbiont capable of causing host cytoplasmic incompatibility (CI). We predict that sympatric host sister-species harbor paraphyletic Wolbachia strains that provide CI, while well-defined congeners in ecological contact and recently diverged noninteracting congeners are uninfected due to Wolbachia redundancy. We argue that Wolbachia provides an adaptive advantage when coupled with reduced hybrid fitness, facilitating assortative mating between co-occurring divergent phenotypes-the contact contingency hypothesis. To test this, we applied a predictive algorithm to empirical pollinating fig wasp data, achieving up to 91.60% accuracy. We further postulate that observed temporal decay of Wolbachia incidence results from adaptive host purging-adaptive decay hypothesis-but implementation failed to predict systematic patterns. We then account for post-zygotic offspring mortality during CI mating, modeling fitness clines across developmental resources-the fecundity trade-off hypothesis. This model regularly favored CI despite fecundity losses. We demonstrate that a rules-based algorithm accurately predicts Wolbachia infection status. This has implications among other systems where closely related sympatric species encounter adaptive disadvantage through hybridization.}, }
@article {pmid35418670, year = {2022}, author = {Titus, BM and Daly, M}, title = {Population genomics for symbiotic anthozoans: can reduced representation approaches be used for taxa without reference genomes?.}, journal = {Heredity}, volume = {128}, number = {5}, pages = {338-351}, pmid = {35418670}, issn = {1365-2540}, mesh = {Animals ; Genome/genetics ; Genomics/methods ; Humans ; *Metagenomics/methods ; Phylogeny ; *Sea Anemones/genetics ; Sequence Analysis, DNA ; }, abstract = {Population genetic studies of symbiotic anthozoans have been historically challenging because their endosymbioses with dinoflagellates have impeded marker development. Genomic approaches like reduced representation sequencing alleviate marker development issues but produce anonymous loci, and without a reference genome, it is unknown which organism is contributing to the observed patterns. Alternative methods such as bait-capture sequencing targeting Ultra-Conserved Elements are now possible but costly. Thus, RADseq remains attractive, but how useful are these methods for symbiotic anthozoan taxa without a reference genome to separate anthozoan from algal sequences? We explore this through a case-study using a double-digest RADseq dataset for the sea anemone Bartholomea annulata. We assembled a holobiont dataset (3854 loci) for 101 individuals, then used a reference genome to create an aposymbiotic dataset (1402 loci). For both datasets, we investigated population structure and used coalescent simulations to estimate demography and population parameters. We demonstrate complete overlap in the spatial patterns of genetic diversity, demographic histories, and population parameter estimates for holobiont and aposymbiotic datasets. We hypothesize that the unique combination of anthozoan biology, diversity of the endosymbionts, and the manner in which assembly programs identify orthologous loci alleviates the need for reference genomes in some circumstances. We explore this hypothesis by assembling an additional 21 datasets using the assembly programs pyRAD and Stacks. We conclude that RADseq methods are more tractable for symbiotic anthozoans without reference genomes than previously realized.}, }
@article {pmid35417002, year = {2022}, author = {Tamarozzi, F and Rodari, P and Salas-Coronas, J and Bottieau, E and Salvador, F and Soriano-Pérez, MJ and Cabeza-Barrera, MI and Van Esbroeck, M and Treviño, B and Buonfrate, D and Gobbi, FG}, title = {A large case series of travel-related Mansonella perstans (vector-borne filarial nematode): a TropNet study in Europe.}, journal = {Journal of travel medicine}, volume = {29}, number = {7}, pages = {}, pmid = {35417002}, issn = {1708-8305}, mesh = {Animals ; Humans ; Mansonella ; *Mansonelliasis/diagnosis/drug therapy/epidemiology ; Retrospective Studies ; Travel ; Mebendazole/therapeutic use ; Prospective Studies ; Travel-Related Illness ; *Wolbachia ; }, abstract = {BACKGROUND: Infection with Mansonella perstans is a neglected filariasis, widely distributed in sub-Saharan Africa, characterized by an elusive clinical picture; treatment for mansonellosis is not standardized. This retrospective study aimed to describe the clinical features, treatment schemes and evolution, of a large cohort of imported cases of M. perstans infection seen in four European centres for tropical diseases.<br><br>METHODS: Mansonella perstans infections, diagnosed by identification of blood microfilariae in migrants, expatriates and travellers, collected between 1994 and 2018, were retrospectively analysed. Data concerning demographics, clinical history and laboratory examinations at diagnosis and at follow-up time points were retrieved.<br><br>RESULTS: A total of 392 patients were included in the study. Of the 281 patients for whom information on symptoms could be retrieved, 150 (53.4%) reported symptoms, abdominal pain and itching being the most frequent. Positive serology and eosinophilia were present in 84.4% and 66.1%, respectively, of those patients for whom these data were available. Concomitant parasitic infections were reported in 23.5% of patients. Treatment, administered to 325 patients (82.9%), was extremely heterogeneous between and within centres; the most commonly used regimen was mebendazole 100&#xa0;mg twice a day for 1 month. A total of 256 (65.3%) patients attended a first follow-up, median 3&#xa0;months (interquartile range 2-12) after the first visit; 83.1% of patients having received treatment based on mebendazole and/or doxycycline, targeting Wolbachia, became amicrofilaremic, 41.1-78.4% of whom within 12&#xa0;months from single treatment.<br><br>CONCLUSIONS: Lack of specific symptoms, together with the inconstant positivity of parasitological and antibody-based assays in the infected population, makes the clinical suspicion and screening for mansonellosis particularly difficult. Prospective studies evaluating prevalence of infection in migrants from endemic areas, infection-specific morbidity, presence of Wolbachia endosymbionts in M. perstans populations from different geographical areas and efficacy of treatment regimens are absolutely needed to optimize the clinical management of infection.}, }
@article {pmid35416714, year = {2022}, author = {Gu, X and Lu, X and Lin, S and Shi, X and Shen, Y and Lu, Q and Yang, Y and Yang, J and Cai, J and Fu, C and Lou, Y and Zheng, M}, title = {A Comparative Genomic Approach to Determine the Virulence Factors and Horizontal Gene Transfer Events of Clinical Acanthamoeba Isolates.}, journal = {Microbiology spectrum}, volume = {10}, number = {2}, pages = {e0002522}, pmid = {35416714}, issn = {2165-0497}, mesh = {*Acanthamoeba/genetics/microbiology ; *Gene Transfer, Horizontal ; Genomics ; Humans ; Phylogeny ; Pseudomonas ; Virulence Factors/genetics ; }, abstract = {Acanthamoeba species are among the most ubiquitous protists that are widespread in soil and water and act as both a replicative niche and vectors for dispersal. They are the most important human intracellular pathogens, causing Acanthamoeba keratitis (AK) and severely damaging the human cornea. The sympatric lifestyle within the host and amoeba-resisting microorganisms (ARMs) promotes horizontal gene transfer (HGT). However, the genomic diversity of only A. castellanii and A. polyphaga has been widely studied, and the pathogenic mechanisms remain unknown. Thus, we examined 7 clinically pathogenic strains by comparative genomic, phylogenetic, and rhizome gene mosaicism analyses to explore amoeba-symbiont interactions that possibly contribute to pathogenesis. Genetic characterization and phylogenetic analysis showed differences in functional characteristics between the "open" state of T3 and T4 isolates, which may contribute to the differences in virulence and pathogenicity. Through comparative genomic analysis, we identified potential genes related to virulence, such as metalloprotease, laminin-binding protein, and HSP, that were specific to the genus Acanthamoeba. Then, analysis of putative sequence trafficking between Acanthamoeba and Pandoraviruses or Acanthamoeba castellanii medusaviruses provided the best hits with viral genes; among bacteria, Pseudomonas had the most significant numbers. The most parsimonious evolutionary scenarios were between Acanthamoeba and endosymbionts; nevertheless, in most cases, the scenarios are more complex. In addition, the differences in exchanged genes were limited to the same family. In brief, this study provided extensive data to suggest the existence of HGT between Acanthamoeba and ARMs, explaining the occurrence of diseases and challenging Darwin's concept of eukaryotic evolution. IMPORTANCEAcanthamoeba has the ability to cause serious blinding keratitis. Although the prevalence of this phenomenon has increased in recent years, our knowledge of the underlying opportunistic pathogenic mechanism maybe remains incomplete. In this study, we highlighted the importance of Pseudomonas in the pathogenesis pathway using comprehensive a whole genomics approach of clinical isolates. The horizontal gene transfer events help to explain how endosymbionts contribute Acanthamoeba to act as an opportunistic pathogen. Our study opens up several potential avenues for future research on the differences in pathogenicity and interactions among clinical strains.}, }
@article {pmid35414231, year = {2022}, author = {Hornett, EA and Kageyama, D and Hurst, GDD}, title = {Sex determination systems as the interface between male-killing bacteria and their hosts.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1972}, pages = {20212781}, pmid = {35414231}, issn = {1471-2954}, mesh = {Animals ; *Arthropods/microbiology ; Bacteria/genetics ; Male ; Sex Ratio ; Symbiosis ; *Wolbachia/physiology ; }, abstract = {Arthropods host a range of sex-ratio-distorting selfish elements, including diverse maternally inherited endosymbionts that solely kill infected males. Male-killing heritable microbes are common, reach high frequency, but until recently have been poorly understood in terms of the host-microbe interaction. Additionally, while male killing should generate strong selection for host resistance, evidence of this has been scant. The interface of the microbe with host sex determination is integral to the understanding of how death is sex limited and how hosts can evolve evasion of male killing. We first review current knowledge of the mechanisms diverse endosymbionts use to induce male-specific death. We then examine recent evidence that these agents do produce intense selection for host nuclear suppressor elements. We argue, from our understanding of male-killing mechanisms, that suppression will commonly involve evolution of the host sex determination pathways and that the host's response to male-killing microbes thus represents an unrecognized driver of the diversity of arthropod sex determination. Further work is required to identify the genes and mechanisms responsible for male-killing suppression, which will both determine the components of sex determination (or other) systems associated with suppressor evolution, and allow insight into the mechanism of male killing itself.}, }
@article {pmid35413060, year = {2022}, author = {Vandepol, N and Liber, J and Yocca, A and Matlock, J and Edger, P and Bonito, G}, title = {Linnemannia elongata (Mortierellaceae) stimulates Arabidopsis thaliana aerial growth and responses to auxin, ethylene, and reactive oxygen species.}, journal = {PloS one}, volume = {17}, number = {4}, pages = {e0261908}, pmid = {35413060}, issn = {1932-6203}, mesh = {*Arabidopsis/metabolism ; *Burkholderia/genetics ; Ethylenes ; Indoleacetic Acids/metabolism ; *Mycorrhizae/physiology ; Plant Roots/metabolism ; Reactive Oxygen Species/metabolism ; Symbiosis ; }, abstract = {Harnessing the plant microbiome has the potential to improve agricultural yields and protect plants against pathogens and/or abiotic stresses, while also relieving economic and environmental costs of crop production. While previous studies have gained valuable insights into the underlying genetics facilitating plant-fungal interactions, these have largely been skewed towards certain fungal clades (e.g. arbuscular mycorrhizal fungi). Several different phyla of fungi have been shown to positively impact plant growth rates, including Mortierellaceae fungi. However, the extent of the plant growth promotion (PGP) phenotype(s), their underlying mechanism(s), and the impact of bacterial endosymbionts on fungal-plant interactions remain poorly understood for Mortierellaceae. In this study, we focused on the symbiosis between soil fungus Linnemannia elongata (Mortierellaceae) and Arabidopsis thaliana (Brassicaceae), as both organisms have high-quality reference genomes and transcriptomes available, and their lifestyles and growth requirements are conducive to research conditions. Further, L. elongata can host bacterial endosymbionts related to Mollicutes and Burkholderia. The role of these endobacteria on facilitating fungal-plant associations, including potentially further promoting plant growth, remains completely unexplored. We measured Arabidopsis aerial growth at early and late life stages, seed production, and used mRNA sequencing to characterize differentially expressed plant genes in response to fungal inoculation with and without bacterial endosymbionts. We found that L. elongata improved aerial plant growth, seed mass and altered the plant transcriptome, including the upregulation of genes involved in plant hormones and "response to oxidative stress", "defense response to bacterium", and "defense response to fungus". Furthermore, the expression of genes in certain phytohormone biosynthetic pathways were found to be modified in plants treated with L. elongata. Notably, the presence of Mollicutes- or Burkholderia-related endosymbionts in Linnemannia did not impact the expression of genes in Arabidopsis or overall growth rates. Together, these results indicate that beneficial plant growth promotion and seed mass impacts of L. elongata on Arabidopsis are likely driven by plant hormone and defense transcription responses after plant-fungal contact, and that plant phenotypic and transcriptional responses are independent of whether the fungal symbiont is colonized by Mollicutes or Burkholderia-related endohyphal bacteria.}, }
@article {pmid35395710, year = {2022}, author = {Camp, EF and Nitschke, MR and Clases, D and Gonzalez de Vega, R and Reich, HG and Goyen, S and Suggett, DJ}, title = {Micronutrient content drives elementome variability amongst the Symbiodiniaceae.}, journal = {BMC plant biology}, volume = {22}, number = {1}, pages = {184}, pmid = {35395710}, issn = {1471-2229}, mesh = {Animals ; *Anthozoa ; *Dinoflagellida ; Micronutrients ; Symbiosis ; }, abstract = {BACKGROUND: Elements are the basis of life on Earth, whereby organisms are essentially evolved chemical substances that dynamically interact with each other and their environment. Determining species elemental quotas (their elementome) is a key indicator for their success across environments with different resource availabilities. Elementomes remain undescribed for functionally diverse dinoflagellates within the family Symbiodiniaceae that includes coral endosymbionts. We used dry combustion and ICP-MS to assess whether Symbiodiniaceae (ten isolates spanning five genera Breviolum, Cladocopium, Durusdinium, Effrenium, Symbiodinium) maintained under long-term nutrient replete conditions have unique elementomes (six key macronutrients and nine micronutrients) that would reflect evolutionarily conserved preferential elemental acquisition. For three isolates we assessed how elevated temperature impacted their elementomes. Further, we tested whether Symbiodiniaceae conform to common stoichiometric hypotheses (e.g., the growth rate hypothesis) documented in other marine algae. This study considers whether Symbiodiniaceae isolates possess unique elementomes reflective of their natural ecologies, evolutionary histories, and resistance to environmental change.<br><br>RESULTS: Symbiodiniaceae isolates maintained under long-term luxury uptake conditions, all exhibited highly divergent elementomes from one another, driven primarily by differential content of micronutrients. All N:P and C:P ratios were below the Redfield ratio values, whereas C:N was close to the Redfield value. Elevated temperature resulted in a more homogenised elementome across isolates. The Family-level elementome was (C19.8N2.6 P1.0S18.8K0.7Ca0.1) &#xb7; 1000 (Fe55.7Mn5.6Sr2.3Zn0.8Ni0.5Se0.3Cu0.2Mo0.1V0.04) mmol Phosphorous[-1] versus (C25.4N3.1P1.0S23.1K0.9Ca0.4) &#xb7; 1000 (Fe66.7Mn6.3Sr7.2Zn0.8Ni0.4Se0.2Cu0.2Mo0.2V0.05) mmol Phosphorous [-1] at 27.4 &#xb1; 0.4 &#xb0;C and 30.7 &#xb1; 0.01 &#xb0;C, respectively. Symbiodiniaceae isolates tested here conformed to some, but not all, stoichiometric principles.<br><br>CONCLUSIONS: Elementomes for Symbiodiniaceae diverge from those reported for other marine algae, primarily via lower C:N:P and different micronutrient expressions. Long-term maintenance of Symbiodiniaceae isolates in culture under common nutrient replete conditions suggests isolates have evolutionary conserved preferential uptake for certain elements that allows these unique elementomes to be identified. Micronutrient content (normalised to phosphorous) commonly increased in the Symbiodiniaceae isolates in response to elevated temperature, potentially indicating a common elemental signature to warming.}, }
@article {pmid35373850, year = {2022}, author = {Ajendra, J and Allen, JE}, title = {Neutrophils: Friend or foe in Filariasis?.}, journal = {Parasite immunology}, volume = {44}, number = {6}, pages = {e12918}, doi = {10.1111/pim.12918}, pmid = {35373850}, issn = {1365-3024}, support = {MR/V011235/1/MRC_/Medical Research Council/United Kingdom ; 106898/A/15/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Elephantiasis, Filarial ; *Filarioidea ; Humans ; Immunity ; Mice ; Neutrophils ; *Wolbachia ; }, abstract = {Infection with the filarial nematodes that cause diseases such as lymphatic filariasis and onchocerciasis represent major public health challenges. With millions of people at risk of infection, new strategies for treatment or prevention are urgently needed. More complete understanding of the host immune system's ability to control and eliminate the infection is an important step towards fighting these debilitating infectious diseases. Neutrophils are innate immune cells that are rapidly recruited to inflamed or infected tissues and while considered primarily anti-microbial, there is increasing recognition of their role in helminth infections. Filarial nematodes present a unique situation, as many species harbour the bacterial endosymbiont, Wolbachia. The unexpected involvement of neutrophils during filarial infections has been revealed both in human diseases and animal studies, with strong evidence for recruitment by Wolbachia. This present review will introduce the different human filarial diseases and discuss neutrophil involvement in both protective immune responses, but also in the exacerbation of pathology. Additionally, we will highlight the contributions of the murine model of filariasis, Litomosoides sigmodontis. While several studies have revealed the importance of neutrophils in these parasite infections, we will also draw attention to many questions that remain to be answered.}, }
@article {pmid35369521, year = {2022}, author = {Lupini, S and Peña-Bahamonde, J and Bonito, G and Rodrigues, DF}, title = {Effect of Endosymbiotic Bacteria on Fungal Resistance Toward Heavy Metals.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {822541}, pmid = {35369521}, issn = {1664-302X}, abstract = {Most studies on metal removal or tolerance by fungi or bacteria focus on single isolates, without taking into consideration that some fungi in nature may be colonized by endobacteria. To address this knowledge gap, we investigated the tolerance and removal of diverse metals with two fungal species: Linnemannia elongata containing Burkholderia-related endobacteria and Benniella erionia containing Mollicute-related endobacteria. Isogenic lines of both species were generated with antibiotic treatments to remove their respective endobacteria. Experiments involved comparing the isogenic lines and wild type fungi in relation to the minimum inhibitory concentration for the metals, the fungal ability to remove these different metals via atomic adsorption spectroscopy, and the interaction of the metals with specific functional groups of the fungi and fungi-bacteria to determine the role of the bacteria via attenuated total reflection fourier transformed infrared (ATR-FTIR). Finally, we determined the influence of different metal concentrations, associated with moderate and high fungal growth inhibition, on the presence of the endobacteria inside the fungal mycelium via quantitative real-time PCR. Results showed that the presence of the endosymbiont increased B. erionia resistance to Mn[2+] and increased the removal of Fe[2+] compared to isogenic lines. The absence of the endosymbiont in L. elongata increased the fungal resistance toward Fe[2+] and improved the removal of Fe[2+]. Furthermore, when the bacterial endosymbiont was present in L. elongata, a decrease in the fungal resistance to Ca[2+], Fe[2+], and Cr[6+]was noticeable. In the ATR-FTIR analysis, we determined that C-H and C = O were the major functional groups affected by the presence of Cu[2+], Mn[2+], and Fe[2+] for L. elongata and in the presence of Cu[2+] and Ca[2+] for B. eronia. It is noteworthy that the highest concentration of Pb[2+] led to the loss of endobacteria in both L. elongata and B. eronia, while the other metals generally increased the concentration of endosymbionts inside the fungal mycelium. From these results, we concluded that bacterial endosymbionts of fungi can play a fundamental role in fungal resistance to metals. This study provides the first step toward a greater understanding of symbiotic interactions between bacteria and fungi in relation to metal tolerance and remediation.}, }
@article {pmid35369505, year = {2022}, author = {Flores, E and Romanovicz, DK and Nieves-Morión, M and Foster, RA and Villareal, TA}, title = {Adaptation to an Intracellular Lifestyle by a Nitrogen-Fixing, Heterocyst-Forming Cyanobacterial Endosymbiont of a Diatom.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {799362}, pmid = {35369505}, issn = {1664-302X}, abstract = {The symbiosis between the diatom Hemiaulus hauckii and the heterocyst-forming cyanobacterium Richelia intracellularis makes an important contribution to new production in the world's oceans, but its study is limited by short-term survival in the laboratory. In this symbiosis, R. intracellularis fixes atmospheric dinitrogen in the heterocyst and provides H. hauckii with fixed nitrogen. Here, we conducted an electron microscopy study of H. hauckii and found that the filaments of the R. intracellularis symbiont, typically composed of one terminal heterocyst and three or four vegetative cells, are located in the diatom's cytoplasm not enclosed by a host membrane. A second prokaryotic cell was also detected in the cytoplasm of H. hauckii, but observations were infrequent. The heterocysts of R. intracellularis differ from those of free-living heterocyst-forming cyanobacteria in that the specific components of the heterocyst envelope seem to be located in the periplasmic space instead of outside the outer membrane. This specialized arrangement of the heterocyst envelope and a possible association of the cyanobacterium with oxygen-respiring mitochondria may be important for protection of the nitrogen-fixing enzyme, nitrogenase, from photosynthetically produced oxygen. The cell envelope of the vegetative cells of R. intracellularis contained numerous membrane vesicles that resemble the outer-inner membrane vesicles of Gram-negative bacteria. These vesicles can export cytoplasmic material from the bacterial cell and, therefore, may represent a vehicle for transfer of fixed nitrogen from R. intracellularis to the diatom's cytoplasm. The specific morphological features of R. intracellularis described here, together with its known streamlined genome, likely represent specific adaptations of this cyanobacterium to an intracellular lifestyle.}, }
@article {pmid35369485, year = {2022}, author = {Hussain, S and Perveen, N and Hussain, A and Song, B and Aziz, MU and Zeb, J and Li, J and George, D and Cabezas-Cruz, A and Sparagano, O}, title = {The Symbiotic Continuum Within Ticks: Opportunities for Disease Control.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {854803}, pmid = {35369485}, issn = {1664-302X}, abstract = {Among blood-sucking arthropods, ticks are recognized as being of prime global importance because of their role as vectors of pathogens affecting human and animal health. Ticks carry a variety of pathogenic, commensal, and symbiotic microorganisms. For the latter, studies are available concerning the detection of endosymbionts, but their role in the physiology and ecology of ticks remains largely unexplored. This review paper focuses on tick endosymbionts of the genera Coxiella, Rickettsia, Francisella, Midichloria, and Wolbachia, and their impact on ticks and tick-pathogen interactions that drive disease risk. Tick endosymbionts can affect tick physiology by influencing nutritional adaptation, fitness, and immunity. Further, symbionts may influence disease ecology, as they interact with tick-borne pathogens and can facilitate or compete with pathogen development within the vector tissues. Rickettsial symbionts are frequently found in ticks of the genera of Ixodes, Amblyomma, and Dermacentor with relatively lower occurrence in Rhipicephalus, Haemaphysalis, and Hyalomma ticks, while Coxiella-like endosymbionts (CLEs) were reported infecting almost all tick species tested. Francisella-like endosymbionts (FLEs) have been identified in tick genera such as Dermacentor, Amblyomma, Ornithodoros, Ixodes, and Hyalomma, whereas Wolbachia sp. has been detected in Ixodes, Amblyomma, Hyalomma, and Rhipicephalus tick genera. Notably, CLEs and FLEs are obligate endosymbionts essential for tick survival and development through the life cycle. American dog ticks showed greater motility when infected with Rickettsia, indirectly influencing infection risk, providing evidence of a relationship between tick endosymbionts and tick-vectored pathogens. The widespread occurrence of endosymbionts across the tick phylogeny and evidence of their functional roles in ticks and interference with tick-borne pathogens suggests a significant contribution to tick evolution and/or vector competence. We currently understand relatively little on how these endosymbionts influence tick parasitism, vector capacity, pathogen transmission and colonization, and ultimately on how they influence tick-borne disease dynamics. Filling this knowledge gap represents a major challenge for future research.}, }
@article {pmid35364056, year = {2022}, author = {Andreychuk, S and Yakob, L}, title = {Mathematical modelling to assess the feasibility of Wolbachia in malaria vector biocontrol.}, journal = {Journal of theoretical biology}, volume = {542}, number = {}, pages = {111110}, doi = {10.1016/j.jtbi.2022.111110}, pmid = {35364056}, issn = {1095-8541}, mesh = {*Aedes ; Animals ; *Anopheles ; Feasibility Studies ; *Malaria ; Models, Theoretical ; Mosquito Vectors ; *Wolbachia ; }, abstract = {Releasing mosquitoes transinfected with the endosymbiotic bacterium Wolbachia is a novel strategy for interrupting vector-borne pathogen transmission. Following its success in controlling arboviruses spread by Aedes aegypti, this technology is being adapted for anopheline malaria vectors. However, antagonistic interactions between Wolbachia and naturally resident Asaia bacteria in malaria vectors have been demonstrated experimentally, potentially jeopardising Wolbachia biocontrol. We developed the first mathematical model accounting for interspecific competition between endosymbionts to assess the feasibility of this novel strategy for controlling malaria. First, Asaia prevalences among natural mosquito populations were compared with simulations parametrized with rates of Asaia transmission reported from laboratory studies. Discrepancies between projections and natural Asaia prevalences indicated potential overestimation of Asaia transmissibility in artificial laboratory settings. With parametrization that matches natural Asaia prevalence, simulations identified redundancies in Asaia's many infection routes (vertical, sexual and environmental). This resilience was only overcome when Wolbachia conferred very high resistance to environmental infection with Asaia, resulting in Wolbachia fixation and Asaia exclusion. Wolbachia's simulated spread was prevented when its maternal transmission was impeded in coinfected mosquitoes and the pre-control Asaia prevalence was beyond a threshold of 60-75%. This theoretical assessment highlights critical next steps in laboratory experiments to inform this strategy's feasibility.}, }
@article {pmid35357208, year = {2022}, author = {Strunov, A and Schmidt, K and Kapun, M and Miller, WJ}, title = {Restriction of Wolbachia Bacteria in Early Embryogenesis of Neotropical Drosophila Species via Endoplasmic Reticulum-Mediated Autophagy.}, journal = {mBio}, volume = {13}, number = {2}, pages = {e0386321}, pmid = {35357208}, issn = {2150-7511}, mesh = {Animals ; Autophagy ; Drosophila/microbiology ; Embryonic Development ; Endoplasmic Reticulum ; *Wolbachia/genetics ; }, abstract = {Wolbachia are maternally transmitted intracellular bacteria that are not only restricted to the reproductive organs but also found in various somatic tissues of their native hosts. The abundance of the endosymbiont in the soma, usually a dead end for vertically transmitted bacteria, causes a multitude of effects on life history traits of their hosts, which are still not well understood. Thus, deciphering the host-symbiont interactions on a cellular level throughout a host's life cycle is of great importance to understand their homeostatic nature, persistence, and spreading success. Using fluorescent and transmission electron microscopy, we conducted a comprehensive analysis of Wolbachia tropism in soma and germ line of six Drosophila species at the intracellular level during host development. Our data uncovered diagnostic patterns of infections to embryonic primordial germ cells and to particular cells of the soma in three different neotropical Drosophila species that have apparently evolved independently. We further found that restricted patterns of Wolbachia tropism are determined in early embryogenesis via selective autophagy, and their spatially restricted infection patterns are preserved in adult flies. We observed tight interactions of Wolbachia with membranes of the endoplasmic reticulum, which might play a scaffolding role for autophagosome formation and subsequent elimination of the endosymbiont. Finally, by analyzing D. simulans lines transinfected with nonnative Wolbachia, we uncovered that the host genetic background regulates tissue tropism of infection. Our data demonstrate a novel and peculiar mechanism to limit and spatially restrict bacterial infection in the soma during a very early stage of host development. IMPORTANCE All organisms are living in close and intimate interactions with microbes that cause conflicts but also cooperation between both unequal genetic partners due to their different innate interests of primarily enhancing their own fitness. However, stable symbioses often result in homeostatic interaction, named mutualism, by balancing costs and benefits, where both partners profit. Mechanisms that have evolved to balance and stably maintain homeostasis in mutualistic relationships are still quite understudied; one strategy is to "domesticate" potentially beneficial symbionts by actively controlling their replication rate below a critical and, hence, costly threshold, and/or to spatially and temporally restrict their localization in the host organism, which, in the latter case, in its most extreme form, is the formation of a specialized housing organ for the microbe (bacteriome). However, questions remain: how do these mutualistic associations become established in their first place, and what are the mechanisms for symbiont control and restriction in their early stages? Here, we have uncovered an unprecedented symbiont control mechanism in neotropical Drosophila species during early embryogenesis. The fruit fly evolved selective autophagy to restrict and control the proliferation of its intracellular endosymbiont Wolbachia in a defined subset of the stem cells as soon as the host's zygotic genome is activated.}, }
@article {pmid35353007, year = {2022}, author = {Li, TP and Zhou, CY and Wang, MK and Zha, SS and Chen, J and Bing, XL and Hoffmann, AA and Hong, XY}, title = {Endosymbionts Reduce Microbiome Diversity and Modify Host Metabolism and Fecundity in the Planthopper Sogatella furcifera.}, journal = {mSystems}, volume = {7}, number = {2}, pages = {e0151621}, pmid = {35353007}, issn = {2379-5077}, abstract = {Endosymbionts can strongly affect bacterial microbiota in pests. The white-backed planthopper Sogatella furcifera, a notorious pest in rice, is usually co-infected with Cardinium and Wolbachia, but the effects of these endosymbionts together or individually on the host microbiome and fecundity are unclear. Here, we established three S. furcifera lines (Cardinium and Wolbachia double-infected, Cardinium single-infected, and both-uninfected lines) backcrossed to a common nuclear background and found that single and double infections reduced bacterial diversity and changed bacterial community structure across nymph and adult stages and across adult tissues. The endosymbionts differed in densities between adults and nymphs as well as across adult tissues, with the distribution of Cardinium affected by Wolbachia. Both the single infection and particularly the double infection reduced host fecundity. Lines also differed in levels of metabolites, some of which may influence fecundity (e.g., arginine biosynthesis and nicotinamide metabolism). Cardinium in the single-infected line upregulated metabolic levels, while Wolbachia in the double-infected line appeared to mainly downregulate them. Association analysis pointed to possible connections between various bacteria and differential metabolites. These results reveal that Cardinium by itself and in combination with Wolbachia affect bacterial microbiota and levels of metabolites, with likely effects on host fecundity. Many of the effects of these metabolically limited endosymbionts that are dependent on the hosts may be exerted through manipulation of the microbiome. IMPORTANCE Endosymbionts can profoundly affect the nutrition, immunity, development, and reproduction of insect hosts, but the effects of multiple endosymbiont infections on microbiota and the interaction of these effects with insect host fitness are not well known. By establishing S. furcifera lines with different endosymbiont infection status, we found that Cardinium and the combined Cardinium + Wolbachia infections differentially reduced bacterial diversity as well as changing bacterial community structure and affecting metabolism, which may connect to negative fitness effects of the endosymbionts on their host. These results established the connections between reduced bacterial diversity, decreased fecundity and metabolic responses in S. furcifera.}, }
@article {pmid35350856, year = {2022}, author = {Katlav, A and Cook, JM and Riegler, M}, title = {Common endosymbionts affect host fitness and sex allocation via egg size provisioning.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1971}, pages = {20212582}, pmid = {35350856}, issn = {1471-2954}, mesh = {Animals ; *Arthropods ; Bacteroidetes ; Female ; Humans ; Male ; Reproduction ; Symbiosis ; *Wolbachia ; }, abstract = {It is hard to overemphasize the importance of endosymbionts in arthropod biology, ecology and evolution. Some endosymbionts can complement host metabolic function or provide defence against pathogens; others, such as ubiquitous Wolbachia and Cardinium, have evolved strategies to manipulate host reproduction. A common reproductive manipulation strategy is cytoplasmic incompatibility (CI) between differently infected individuals which can result in female mortality or male development of fertilized eggs in haplodiploid hosts. Recently, an additional role of endosymbionts has been recognized in the modification of sex allocation in sexually reproducing haplodiploids. This was theoretically expected due to the maternal inheritance of endosymbionts and natural selection for them to increase infected female production, yet the underlying mechanism remained unknown. Here, we tested whether and how Cardinium and Wolbachia causing different CI types interact to increase female production in a haplodiploid thrips species where sex allocation depends on both maternal condition and egg size provisioning. We found that Cardinium augmented female production by increasing maternal fitness and egg size, thereby boosting fertilization rate and offspring fitness. Wolbachia, in contrast, reduced the beneficial effects of Cardinium. Our results demonstrate different invasion strategies and antagonistic effects of endosymbiotic bacteria on host fitness and evolution of sex allocation.}, }
@article {pmid35349818, year = {2022}, author = {Hochstrasser, M}, title = {Cytoplasmic incompatibility: A Wolbachia toxin-antidote mechanism comes into view.}, journal = {Current biology : CB}, volume = {32}, number = {6}, pages = {R287-R289}, doi = {10.1016/j.cub.2022.02.014}, pmid = {35349818}, issn = {1879-0445}, mesh = {Animals ; Antidotes ; Cytoplasm ; Cytosol ; Drosophila melanogaster/genetics ; *Wolbachia/genetics ; }, abstract = {The Wolbachia cidA and cidB genes promote bacterial endosymbiont inheritance through the host female germline. CidB is now shown to load into maturing sperm nuclei. Following fertilization, it disrupts paternal chromosome condensation, triggering embryonic arrest if not countered by CidA in Wolbachia-infected eggs.}, }
@article {pmid35349727, year = {2022}, author = {Hsu, V and Pfab, F and Moeller, HV}, title = {Niche expansion via acquired metabolism facilitates competitive dominance in planktonic communities.}, journal = {Ecology}, volume = {103}, number = {7}, pages = {e3693}, doi = {10.1002/ecy.3693}, pmid = {35349727}, issn = {1939-9170}, mesh = {*Ecosystem ; *Paramecium ; Photosynthesis ; Plankton ; }, abstract = {Acquired phototrophs, organisms that obtain their photosynthetic abilities by hosting endosymbionts or stealing plastids from their prey, are omnipresent in aquatic ecosystems. This acquisition of photosynthetic metabolism allows for niche expansion, and can therefore influence competition outcomes by alleviating competition for shared resources. Here, we test how acquired metabolism alters competitive outcomes by manipulating light availability to control the energetic contribution of photosynthesis to acquired phototrophs. Using freshwater protists that compete for bacterial prey, we demonstrate light-dependent competition outcomes of acquired phototrophs (Paramecium bursaria) and strict heterotrophs (Colpidium sp.) in laboratory model experiments. We then synthesize these findings using a series of mathematical models, and show that explicitly accounting for resource competition improves model fits. Both empirical and mathematical models predict that the acquired phototroph should increase in competitive dominance with increasing light availability. Our results highlight the importance of acquired metabolism to community dynamics, highlighting the need for more empirical and theoretical studies of this mechanism for niche expansion.}, }
@article {pmid35346758, year = {2022}, author = {Bazzocchi, C and Genchi, M and Lucchetti, C and Cafiso, A and Ciuca, L and McCall, J and Kramer, LH and Vismarra, A}, title = {Transporter gene expression and Wolbachia quantification in adults of Dirofilaria immitis treated in vitro with ivermectin or moxidectin alone or in combination with doxycycline for 12 h.}, journal = {Molecular and biochemical parasitology}, volume = {249}, number = {}, pages = {111475}, doi = {10.1016/j.molbiopara.2022.111475}, pmid = {35346758}, issn = {1872-9428}, mesh = {Animals ; *Dirofilaria immitis/genetics ; *Dog Diseases/drug therapy/parasitology/prevention &amp; control ; Dogs ; Doxycycline/pharmacology/therapeutic use ; Female ; Gene Expression ; Ivermectin/pharmacology ; Macrolides ; Male ; Membrane Transport Proteins/genetics ; *Wolbachia/genetics ; }, abstract = {Due to their marked larvicidal activity, macrocyclic lactones (MLs) are used for the prevention of heartworm disease (Dirofilaria immitis) in dogs. They have also been shown to eliminate adult parasites after long-term administration, with a so-called "slow-kill" effect. In addition, recent studies have established that a combination of doxycycline, which eliminates the endosymbiont Wolbachia, and MLs has superior adulticide effects when compared to MLs alone. It has been hypothesized that the apparent synergism between doxycycline/MLs may be due to interaction with drug efflux transport proteins. The aim of the present study was to evaluate gene expression of several transport proteins in D. immitis adults treated in vitro either with doxycycline alone, ivermectin alone, moxidectin alone, or a combination of ivermectin or moxidectin with doxycycline for 12 h. Quantitative PCR analysis showed a sex-dependent response to treatments. In female worms, Dim-pgp-10, Dim-haf-1 and Dim-haf-5 were upregulated compared to controls with doxycycline alone and when combined with ivermectin. Moxidectin did not induce any changes in gene expression. In males, moxidectin administered alone induced a slight increase in Dim-pgp-10, Dim-pgp-11and Di-avr-14, while ivermectin in combination with doxycycline produced significant upregulation of the ML receptor Di-avr-14. These results suggest possible synergism between the two drug classes and different susceptibility of males vs. females to adulticide effects.}, }
@article {pmid35346038, year = {2022}, author = {Queffelec, J and Postma, A and Allison, JD and Slippers, B}, title = {Remnants of horizontal transfers of Wolbachia genes in a Wolbachia-free woodwasp.}, journal = {BMC ecology and evolution}, volume = {22}, number = {1}, pages = {36}, pmid = {35346038}, issn = {2730-7182}, mesh = {Animals ; *Nematoda ; *Pinus ; *Wasps/genetics ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Wolbachia is a bacterial endosymbiont of many arthropod and nematode species. Due to its capacity to alter host biology, Wolbachia plays an important role in arthropod and nematode ecology and evolution. Sirex noctilio is a woodwasp causing economic loss in pine plantations of the Southern Hemisphere. An investigation into the genome of this wasp revealed the presence of Wolbachia sequences. Due to the potential impact of Wolbachia on the populations of this wasp, as well as its potential use as a biological control agent against invasive insects, this discovery warranted investigation.<br><br>RESULTS: In this study we first investigated the presence of Wolbachia in S. noctilio and demonstrated that South African populations of the wasp are unlikely to be infected. We then screened the full genome of S. noctilio and found 12 Wolbachia pseudogenes. Most of these genes constitute building blocks of various transposable elements originating from the Wolbachia genome. Finally, we demonstrate that these genes are distributed in all South African populations of the wasp.<br><br>CONCLUSIONS: Our results provide evidence that S. noctilio might be compatible with a Wolbachia infection and that the bacteria could potentially be used in the future to regulate invasive populations of the wasp. Understanding the mechanisms that led to a loss of Wolbachia infection in S. noctilio could indicate which host species or host population should be sampled to find a Wolbachia strain that could be used as a biological control against S. noctilio.}, }
@article {pmid35339983, year = {2022}, author = {Tashyreva, D and Simpson, AGB and Prokopchuk, G and Škodová-Sveráková, I and Butenko, A and Hammond, M and George, EE and Flegontova, O and Záhonová, K and Faktorová, D and Yabuki, A and Horák, A and Keeling, PJ and Lukeš, J}, title = {Diplonemids - A Review on "New" Flagellates on the Oceanic Block.}, journal = {Protist}, volume = {173}, number = {2}, pages = {125868}, doi = {10.1016/j.protis.2022.125868}, pmid = {35339983}, issn = {1618-0941}, mesh = {Animals ; *Euglenozoa/genetics ; Eukaryota/genetics ; Oceans and Seas ; *Parasites ; Phylogeny ; }, abstract = {Diplonemids are a group of flagellate protists, that belong to the phylum Euglenozoa alongside euglenids, symbiontids and kinetoplastids. They primarily inhabit marine environments, though are also found in freshwater lakes. Diplonemids have been considered as rare and unimportant eukaryotes for over a century, with only a handful of species described until recently. However, thanks to their unprecedented diversity and abundance in the world oceans, diplonemids now attract increased attention. Recent improvements in isolation and cultivation have enabled characterization of several new genera, warranting a re-examination of all available knowledge gathered so far. Here we summarize available data on diplonemids, focusing on the recent advances in the fields of diversity, ecology, genomics, metabolism, and endosymbionts. We illustrate the life stages of cultivated genera, and summarise all reported interspecies associations, which in turn suggest lifestyles of predation and parasitism. This review also includes the latest classification of diplonemids, with a taxonomic revision of the genus Diplonema. Ongoing efforts to sequence various diplonemids suggest the presence of large and complex genomes, which correlate with the metabolic versatility observed in the model species Paradiplonema papillatum. Finally, we highlight its successful transformation into one of few genetically tractable marine protists.}, }
@article {pmid35336121, year = {2022}, author = {Neyaz, M and Gardner, DR and Creamer, R and Cook, D}, title = {Localization of the Swainsonine-Producing Chaetothyriales Symbiont in the Seed and Shoot Apical Meristem in Its Host Ipomoea carnea.}, journal = {Microorganisms}, volume = {10}, number = {3}, pages = {}, pmid = {35336121}, issn = {2076-2607}, abstract = {Several species of fungi from the orders Chaetothyriales and Pleosporales have been reported to produce swainsonine and be associated as symbionts with plants of the Convolvulaceae and Fabaceae, respectively. An endosymbiont belonging to the Chaetothyriales produces swainsonine and grows as an epibiont on the adaxial leaf surfaces of Ipomoea carnea, but how the symbiont passes through plant growth and development is unknown. Herein, different types of microscopy were used to localize the symbiont in seeds and in cross sections of plant parts. The symbiont was found in several tissues including the hilum, the sclereids, and the hypocotyl of seeds. In five-day old seedlings and mature plants, the symbiont was found in the shoot apical meristem (SAM) and the adaxial surface of immature folded leaves. The mycelia generally formed a close association with peltate glandular trichomes. This report provides further data explaining the relationship between the seed transmitted Chaetothyriales symbiont and Ipomoea carnea. These results provide a possible explanation for how this symbiont, and others like Periglandula may persist and are transmitted over time.}, }
@article {pmid35336091, year = {2022}, author = {Petrone, JR and Muñoz-Beristain, A and Glusberger, PR and Russell, JT and Triplett, EW}, title = {Unamplified, Long-Read Metagenomic Sequencing Approach to Close Endosymbiont Genomes of Low-Biomass Insect Populations.}, journal = {Microorganisms}, volume = {10}, number = {3}, pages = {}, pmid = {35336091}, issn = {2076-2607}, abstract = {With the current advancements in DNA sequencing technology, the limiting factor in long-read metagenomic assemblies is now the quantity and quality of input DNA. Although these requirements can be met through the use of axenic bacterial cultures or large amounts of biological material, insect systems that contain unculturable bacteria or that contain a low amount of available DNA cannot fully utilize the benefits of third-generation sequencing. The citrus greening disease insect vector Diaphorina citri is an example that exhibits both of these limitations. Although endosymbiont genomes have mostly been closed after the short-read sequencing of amplified template DNA, creating de novo long-read genomes from the unamplified DNA of an insect population may benefit communities using bioinformatics to study insect pathosystems. Here all four genomes of the infected D. citri microbiome were sequenced to closure using unamplified template DNA and two long-read sequencing technologies. Avoiding amplification bias and using long reads to assemble the bacterial genomes allowed for the circularization of the Wolbachia endosymbiont of Diaphorina citri for the first time and paralleled the annotation context of all four reference genomes without utilizing a traditional hybrid assembly. The strategies detailed here are suitable for the sequencing of other insect systems for which the input DNA, time, and cost are an issue.}, }
@article {pmid35328804, year = {2022}, author = {Pacheco, PJ and Cabrera, JJ and Jiménez-Leiva, A and Bedmar, EJ and Mesa, S and Tortosa, G and Delgado, MJ}, title = {Effect of Copper on Expression of Functional Genes and Proteins Associated with Bradyrhizobium diazoefficiens Denitrification.}, journal = {International journal of molecular sciences}, volume = {23}, number = {6}, pages = {}, pmid = {35328804}, issn = {1422-0067}, mesh = {*Bradyrhizobium/genetics/metabolism ; *Copper/metabolism/pharmacology ; Denitrification/genetics ; Nitrates/metabolism/pharmacology ; Nitrite Reductases/genetics/metabolism ; Nitrogen Oxides/metabolism ; Soil ; }, abstract = {Nitrous oxide (N2O) is a powerful greenhouse gas that contributes to climate change. Denitrification is one of the largest sources of N2O in soils. The soybean endosymbiont Bradyrhizobium diazoefficiens is a model for rhizobial denitrification studies since, in addition to fixing N2, it has the ability to grow anaerobically under free-living conditions by reducing nitrate from the medium through the complete denitrification pathway. This bacterium contains a periplasmic nitrate reductase (Nap), a copper (Cu)-containing nitrite reductase (NirK), a c-type nitric oxide reductase (cNor), and a Cu-dependent nitrous oxide reductase (Nos) encoded by the napEDABC, nirK, norCBQD and nosRZDFYLX genes, respectively. In this work, an integrated study of the role of Cu in B. diazoefficiens denitrification has been performed. A notable reduction in nirK, nor, and nos gene expression observed under Cu limitation was correlated with a significant decrease in NirK, NorC and NosZ protein levels and activities. Meanwhile, nap expression was not affected by Cu, but a remarkable depletion in Nap activity was found, presumably due to an inhibitory effect of nitrite accumulated under Cu-limiting conditions. Interestingly, a post-transcriptional regulation by increasing Nap and NirK activities, as well as NorC and NosZ protein levels, was observed in response to high Cu. Our results demonstrate, for the first time, the role of Cu in transcriptional and post-transcriptional control of B. diazoefficiens denitrification. Thus, this study will contribute by proposing useful strategies for reducing N2O emissions from agricultural soils.}, }
@article {pmid35325496, year = {2022}, author = {Rotterová, J and Edgcomb, VP and Čepička, I and Beinart, R}, title = {Anaerobic ciliates as a model group for studying symbioses in oxygen-depleted environments.}, journal = {The Journal of eukaryotic microbiology}, volume = {69}, number = {5}, pages = {e12912}, doi = {10.1111/jeu.12912}, pmid = {35325496}, issn = {1550-7408}, mesh = {Anaerobiosis ; *Ciliophora/genetics ; Ecosystem ; *Oxygen ; Phylogeny ; Symbiosis ; }, abstract = {Anaerobiosis has independently evolved in multiple lineages of ciliates, allowing them to colonize a variety of anoxic and oxygen-depleted habitats. Anaerobic ciliates commonly form symbiotic relationships with various prokaryotes, including methanogenic archaea and members of several bacterial groups. The hypothesized functions of these ecto- and endosymbionts include the symbiont utilizing the ciliate's fermentative end products to increase the host's anaerobic metabolic efficiency, or the symbiont directly providing the host with energy by denitrification or photosynthesis. The host, in turn, may protect the symbiont from competition, the environment, and predation. Despite rapid advances in sampling, molecular, and microscopy methods, as well as the associated broadening of the known diversity of anaerobic ciliates, many aspects of these ciliate symbioses, including host specificity and coevolution, remain largely unexplored. Nevertheless, with the number of comparative genomic and transcriptomic analyses targeting anaerobic ciliates and their symbionts on the rise, insights into the nature of these symbioses and the evolution of the ciliate transition to obligate anaerobiosis continue to deepen. This review summarizes the current body of knowledge regarding the complex nature of symbioses in anaerobic ciliates, the diversity of these symbionts, their role in the evolution of ciliate anaerobiosis and their significance in ecosystem-level processes.}, }
@article {pmid35323529, year = {2022}, author = {Majeed, MZ and Sayed, S and Bo, Z and Raza, A and Ma, CS}, title = {Bacterial Symbionts Confer Thermal Tolerance to Cereal Aphids Rhopalosiphum padi and Sitobion avenae.}, journal = {Insects}, volume = {13}, number = {3}, pages = {}, pmid = {35323529}, issn = {2075-4450}, abstract = {High-temperature events are evidenced to exert significant influence on the population performance and thermal biology of insects, such as aphids. However, it is not yet clear whether the bacterial symbionts of insects mediate the thermal tolerance traits of their hosts. This study is intended to assess the putative association among the chronic and acute thermal tolerance of two cereal aphid species, Rhopalosiphum padi (L.) and Sitobion avenae (F.), and the abundance of their bacterial symbionts. The clones of aphids were collected randomly from different fields of wheat crops and were maintained under laboratory conditions. Basal and acclimated CTmax and chronic thermal tolerance indices were measured for 5-day-old apterous aphid individuals and the abundance (gene copy numbers) of aphid-specific and total (16S rRNA) bacterial symbionts were determined using real-time RT-qPCR. The results reveal that R. padi individuals were more temperature tolerant under chronic exposure to 31 °C and also exhibited about 1.0 °C higher acclimated and basal CTmax values than those of S. avenae. Moreover, a significantly higher bacterial symbionts' gene abundance was recorded in temperature-tolerant aphid individuals than the susceptible ones for both aphid species. Although total bacterial (16S rRNA) abundance per aphid was higher in S. avenae than R. padi, the gene abundance of aphid-specific bacterial symbionts was nearly alike for both of the aphid species. Nevertheless, basal and acclimated CTmax values were positively and significantly associated with the gene abundance of total symbiont density, Buchnera aphidicola, Serratia symbiotica, Hamilton defensa, Regiella insecticola and Spiroplasma spp. for R. padi, and with the total symbiont density, total bacteria (16S rRNA) and with all aphid-specific bacterial symbionts (except Spiroplasma spp.) for S. avenae. The overall study results corroborate the potential role of the bacterial symbionts of aphids in conferring thermal tolerance to their hosts.}, }
@article {pmid35305557, year = {2022}, author = {Purkiss, SA and Khudr, MS and Aguinaga, OE and Hager, R}, title = {Symbiont-conferred immunity interacts with effects of parasitoid genotype and intraguild predation to affect aphid immunity in a clone-specific fashion.}, journal = {BMC ecology and evolution}, volume = {22}, number = {1}, pages = {33}, pmid = {35305557}, issn = {2730-7182}, mesh = {Animals ; *Aphids/genetics ; Clone Cells ; Genotype ; *Parasites ; Predatory Behavior ; *Wasps/genetics ; }, abstract = {BACKGROUND: Host-parasite interactions represent complex co-evolving systems in which genetic and associated phenotypic variation within a species can significantly affect selective pressures on traits, such as host immunity, in the other. While often modelled as a two-species interaction between host and parasite, some systems are more complex due to effects of host enemies, intraguild predation, and endosymbionts, all of which affect host immunity. However, it remains unclear how these factors, combined with genetic variation in the host and the parasitoid, affect host immunity. We address this question in an important agricultural pest system, the pea aphid Acyrthosiphon pisum, which shows significant intraspecific variability in immunity to the parasitoid wasp Aphidius ervi. In a complex experiment, we use a quantitative genetic design in the parasitoid, two ecologically different aphid lineages and the aphid lion Chrysoperla carnea as an intraguild predator to unravel the complex interdependencies.<br><br>RESULTS: We demonstrate that aphid immunity as a key trait of this complex host-parasite system is affected by intraspecific genetic variation in the parasitoid and the aphid, the interaction of intraspecific genetic variation with intraguild predation, and differences in defensive endosymbionts between aphid lineages. Further, aphid lineages differ in their altruistic behaviour whereby infested aphids move away from the clonal colony to facilitate predation.<br><br>CONCLUSIONS: Our findings provide new insights into the influence of endosymbiosis and genetic variability in an important host-parasitoid system which is influenced by natural enemies of the parasitoid and the aphid, including its endosymbiont communities. We show that endosymbiosis can mediate or influence the evolutionary arms race between aphids and their natural enemies. The outcome of these complex interactions between species has significant implications for understanding the evolution of multitrophic systems, including eco-agricultural settings.}, }
@article {pmid35303931, year = {2022}, author = {Hosseini, SH and Manshori-Ghaishghorshagh, F and Ramezani, M and Nayebzadeh, H and Ahoo, MB and Eslamian, A and Soltani, M and Jamshidi, S and Bezerra-Santos, MA and Jalousian, F and Sazmand, A and Otranto, D}, title = {Canine microfilaraemia in some regions of Iran.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {90}, pmid = {35303931}, issn = {1756-3305}, mesh = {Animals ; *Dirofilaria immitis/genetics ; *Dirofilaria repens/genetics ; *Dog Diseases/parasitology ; Dogs ; Iran/epidemiology ; Phylogeny ; }, abstract = {BACKGROUND: Dirofilaria immitis and Dirofilaria repens are vector-borne zoonotic parasites which affect mainly dogs and humans worldwide. In Iran, information about the distribution of those nematodes is scant in several regions. Therefore, we investigated the prevalence of these filarial parasites in stray dogs from five Iranian provinces where no information about these parasites is available.<br><br>METHODS: Blood samples were collected from 344 stray dogs in five provinces of Iran (i.e. Mazandaran, Gilan, Esfahan, Qazvin and Loresan). The presence of microfilariae was assessed using direct smear, modified Knott's test, molecular detection of filarial DNA (cox1 gene) and Wolbachia endosymbiont of parasitic nematodes (ftsZ gene) by conventional PCR (cPCR).&#xa0;All of the PCR products were sequenced and phylogenetic&#xa0;analysis was&#xa0;performed.<br><br>RESULTS: In total, 75 dogs (21.8%) were found to be positive for D. immitis by cPCR. Infection was detected in all provinces, with the highest prevalence in Gilan province (22/28; 78.6%). Acanthocheilonema reconditum was diagnosed in five dogs (1.4%) from three provinces (i.e. Esfahan, Mazandaran, Gilan). Two dogs were infected with both parasites and three were only infected with A. reconditum. Dirofilaria repens infection was not found in the examined population. Representative sequences of the D. immitis cox1 gene from dogs from the northern provinces (Mazandaran, Gilan, Qazvin) were grouped together and distinctly separate from the ones from western and central provinces (Lorestan and Esfahan), suggesting that different nematode populations are present in the country.<br><br>CONCLUSION: The data reported herein fill existing gaps in knowledge about canine filarial infection in two Iranian provinces and record the highest prevalence of D. immitis ever reported in the country (i.e. 78.6%). A geographical review of the literature about Dirofilaria spp. and A. reconditum infections in dogs and humans has also been summarized, indicating that D. immitis and D. repens are distributed in 22 of 31 provinces in Iran, whereas A. reconditum is present in fewer regions. Effective control strategies are advocated for owned dogs, and a national program for the management of stray dogs is needed to minimize the risk of infection in animals and humans.}, }
@article {pmid35299660, year = {2022}, author = {Madeira, C and Dias, M and Ferreira, A and Gouveia, R and Cabral, H and Diniz, MS and Vinagre, C}, title = {Does Predation Exacerbate the Risk of Endosymbiont Loss in Heat Stressed Hermatypic Corals? Molecular Cues Provide Insights Into Species-Specific Health Outcomes in a Multi-Stressor Ocean.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {801672}, pmid = {35299660}, issn = {1664-042X}, abstract = {Ocean warming has been a major driver of coral reef bleaching and mass mortality. Coupled to other biotic pressures, corals' ability for acclimatization and adaptation may become compromised. Here, we tested the combined effects of warming scenarios (26, 30, and 32°C) and predation (wound vs. no wound) in coral health condition (paleness, bleaching, and mortality), cellular stress responses (heat shock protein 70 kDa Hsp70, total ubiquitin Ub, and total antioxidant capacity TAC), and physiological state (integrated biomarker response index, IBR) of seven Scleractinian coral species, after being exposed for 60 days. Results show that although temperature was the main factor driving coral health condition, thermotolerant species (Galaxea fascicularis, Psammocora contigua, and Turbinaria reniformis) displayed increased paleness, bleaching, and mortality in predation treatments at high temperature, whereas thermosensitive species (Acropora tenuis, Echinopora lamellosa, and Montipora capricornis brown and green morphotypes) all died at 32°C, regardless of predation condition. At the molecular level, results show that there were significant main and interactive effects of species, temperature, and predation in the biomarkers assessed. Temperature affected Hsp70, Ub, and TAC, evidencing the role of protein folding and turnover, as well as reactive oxygen species scavenging in heat stress management. Predation increased Hsp70 and Ub, suggesting the activation of the pro-phenoloxidase system and cytokine activity, whereas the combination of both stressors mainly affected TAC during moderate stress and Ub under severe stress, suggesting that redox balance and defense of homeostasis are crucial in tissue repair at high temperature. IBR levels showed an increasing trend at 32°C in predated coral fragments (although non-significant). We conclude that coral responses to the combination of high temperature and predation pressure display high inter-species variability, but these stressors may pose a higher risk of endosymbiont loss, depending on species physiology and stress intensity.}, }
@article {pmid35295292, year = {2022}, author = {Yan, K and Pei, Z and Meng, L and Zheng, Y and Wang, L and Feng, R and Li, Q and Liu, Y and Zhao, X and Wei, Q and El-Sappah, AH and Abbas, M}, title = {Determination of Community Structure and Diversity of Seed-Vectored Endophytic Fungi in Alpinia zerumbet.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {814864}, pmid = {35295292}, issn = {1664-302X}, abstract = {Endophytic fungi act as seed endosymbiont, thereby playing a very crucial role in the growth and development of seeds. Seed-vectored endophytic fungi establish an everlasting association with seeds and travel from generation to generation. To explore the composition and diversity of endophytic fungi in Alpinia zerumbet seeds, high-throughput Illumina MiSeq sequencing was employed for the following stages: fruit formation period (YSJ1), young fruit period (YSJ2), early mature period (YSJ3), middle mature period (YSJ4), and late mature period (YSJ5). A total of 906,694 sequence reads and 745 operational taxonomic units (OTUs) were obtained and further classified into 8 phyla, 30 classes, 73 orders, 163 families, 302 genera, and 449 species. The highest endophytic fungal diversity was observed at YSJ5. The genera with the highest abundance were Cladosporium, Kodamaea, Hannaella, Mycothermus, Gibberella, Sarocladium, and Neopestalotiopsis. Functional Guild (FUNGuild) analysis revealed that endophytic fungi were undefined saprotroph, plant pathogens, animal pathogen-endophyte-lichen parasite-plant pathogen-wood saprotroph, and soil saprotrophs. Alternaria, Fusarium, Cladosporium, and Sarocladium, which are potential probiotics and can be used as biocontrol agents, were also abundant. This study is part of the Sustainable Development Goals of United Nations Organization (UNO) to "Establish Good Health and Well-Being."}, }
@article {pmid35294495, year = {2022}, author = {Bhattacharya, T and Yan, L and Crawford, JM and Zaher, H and Newton, ILG and Hardy, RW}, title = {Differential viral RNA methylation contributes to pathogen blocking in Wolbachia-colonized arthropods.}, journal = {PLoS pathogens}, volume = {18}, number = {3}, pages = {e1010393}, pmid = {35294495}, issn = {1553-7374}, support = {R01 AI144430/AI/NIAID NIH HHS/United States ; R01 GM112641/GM/NIGMS NIH HHS/United States ; R21 AI153785/AI/NIAID NIH HHS/United States ; }, mesh = {5-Methylcytosine/metabolism ; *Aedes ; *Alphavirus/genetics ; Animals ; *Arthropods/genetics ; *Flavivirus/genetics ; Methylation ; Methyltransferases/genetics/metabolism ; RNA, Viral/genetics/metabolism ; Virus Replication ; *Wolbachia/physiology ; }, abstract = {Arthropod endosymbiont Wolbachia pipientis is part of a global biocontrol strategy to reduce the replication of mosquito-borne RNA viruses such as alphaviruses. We previously demonstrated the importance of a host cytosine methyltransferase, DNMT2, in Drosophila and viral RNA as a cellular target during pathogen-blocking. Here we report a role for DNMT2 in Wolbachia-induced alphavirus inhibition in Aedes species. Expression of DNMT2 in mosquito tissues, including the salivary glands, is elevated upon virus infection. Notably, this is suppressed in Wolbachia-colonized animals, coincident with reduced virus replication and decreased infectivity of progeny virus. Ectopic expression of DNMT2 in cultured Aedes cells is proviral, increasing progeny virus infectivity, and this effect of DNMT2 on virus replication and infectivity is dependent on its methyltransferase activity. Finally, examining the effects of Wolbachia on modifications of viral RNA by LC-MS show a decrease in the amount of 5-methylcytosine modification consistent with the down-regulation of DNMT2 in Wolbachia colonized mosquito cells and animals. Collectively, our findings support the conclusion that disruption of 5-methylcytosine modification of viral RNA is a vital mechanism operative in pathogen blocking. These data also emphasize the essential role of epitranscriptomic modifications in regulating fundamental alphavirus replication and transmission processes.}, }
@article {pmid35293790, year = {2022}, author = {Shaffer, JP and Carter, ME and Spraker, JE and Clark, M and Smith, BA and Hockett, KL and Baltrus, DA and Arnold, AE}, title = {Transcriptional Profiles of a Foliar Fungal Endophyte (Pestalotiopsis, Ascomycota) and Its Bacterial Symbiont (Luteibacter, Gammaproteobacteria) Reveal Sulfur Exchange and Growth Regulation during Early Phases of Symbiotic Interaction.}, journal = {mSystems}, volume = {7}, number = {2}, pages = {e0009122}, pmid = {35293790}, issn = {2379-5077}, support = {K12 GM068524/GM/NIGMS NIH HHS/United States ; }, abstract = {Symbiosis with bacteria is widespread among eukaryotes, including fungi. Bacteria that live within fungal mycelia (endohyphal bacteria) occur in many plant-associated fungi, including diverse Mucoromycota and Dikarya. Pestalotiopsis sp. strain 9143 is a filamentous ascomycete isolated originally as a foliar endophyte of Platycladus orientalis (Cupressaceae). It is infected naturally with the endohyphal bacterium Luteibacter sp. strain 9143, which influences auxin and enzyme production by its fungal host. Previous studies have used transcriptomics to examine similar symbioses between endohyphal bacteria and root-associated fungi such as arbuscular mycorrhizal fungi and plant pathogens. However, currently there are no gene expression studies of endohyphal bacteria of Ascomycota, the most species-rich fungal phylum. To begin to understand such symbioses, we developed methods for assessing gene expression by Pestalotiopsis sp. and Luteibacter sp. when grown in coculture and when each was grown axenically. Our assays showed that the density of Luteibacter sp. in coculture was greater than in axenic culture, but the opposite was true for Pestalotiopsis sp. Dual-transcriptome sequencing (RNA-seq) data demonstrate that growing in coculture modulates developmental and metabolic processes in both the fungus and bacterium, potentially through changes in the balance of organic sulfur via methionine acquisition. Our analyses also suggest an unexpected, potential role of the bacterial type VI secretion system in symbiosis establishment, expanding current understanding of the scope and dynamics of fungal-bacterial symbioses. IMPORTANCE Interactions between microbes and their hosts have important outcomes for host and environmental health. Foliar fungal endophytes that infect healthy plants can harbor facultative endosymbionts called endohyphal bacteria, which can influence the outcome of plant-fungus interactions. These bacterial-fungal interactions can be influential but are poorly understood, particularly from a transcriptome perspective. Here, we report on a comparative, dual-RNA-seq study examining the gene expression patterns of a foliar fungal endophyte and a facultative endohyphal bacterium when cultured together versus separately. Our findings support a role for the fungus in providing organic sulfur to the bacterium, potentially through methionine acquisition, and the potential involvement of a bacterial type VI secretion system in symbiosis establishment. This work adds to the growing body of literature characterizing endohyphal bacterial-fungal interactions, with a focus on a model facultative bacterial-fungal symbiosis in two species-rich lineages, the Ascomycota and Proteobacteria.}, }
@article {pmid35292086, year = {2022}, author = {Weck, BC and Serpa, MCA and Ramos, VN and Luz, HR and Costa, FB and Ramirez, DG and Benatti, HR and Piovezan, U and Szabó, MPJ and Marcili, A and Krawczak, FS and Muñoz-Leal, S and Labruna, MB}, title = {Novel genotypes of Hepatozoon spp. in small mammals, Brazil.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {87}, pmid = {35292086}, issn = {1756-3305}, mesh = {Animals ; Brazil/epidemiology ; *Carnivora ; *Eucoccidiida/genetics ; Haplotypes ; Phylogeny ; }, abstract = {BACKGROUND: Small mammals (rodents and marsupials) have been poorly explored for the occurrence of apicomplexan (genus Hepatozoon and genera of the order Piroplasmorida) and Anaplasmataceae agents in Brazil. Thus, this study investigated the occurrence of Hepatozoon spp., Piroplasmorida, and Anaplasmataceae agents in small mammals in seven forest fragments in Brazil.<br><br>METHODS: During 2015-2018, small mammals were captured in six forest fragments in the State of S&#xe3;o Paulo (Cerrado and Atlantic Forest biomes) and one fragment in the State of Mato Grosso do Sul (Pantanal biome). Mammal blood, liver, spleen, and lung samples were tested molecularly for the presence of DNA of Hepatozoon, Piroplasmorida, and Anaplasmataceae agents.<br><br>RESULTS: A total of 524 mammals were captured, comprising seven species of marsupials, 14 rodents, two carnivores, and one Cingulata. Four novel haplotypes (1, 2, 3, 4) of Hepatozoon spp. were detected in small mammals from different biomes. In S&#xe3;o Paulo state, haplotype 1 was detected in rodents from Cerrado and a transition area of Cerrado and Atlantic Forest biomes, whereas haplotype 2 was detected in rodents from the Atlantic Forest biome. On the other hand, haplotypes 3 and 4 were restricted to rodents and marsupials, respectively, from the Pantanal biome of Mato Grosso do Sul. No host species shared more than one haplotype. Despite these distinct geographical and host associations, our phylogenetic analyses indicated that the four Hepatozoon haplotypes belonged to the same clade that contained nearly all haplotypes previously reported on rodents and marsupials, in addition to several reptile-associated haplotypes from different parts of the world. No mammal samples yielded detectable DNA of Piroplasmorida agents. On the other hand, the Anaplasmataceae-targeted polymerase chain reaction (PCR) assay amplified a sequence 100% identical to the Wolbachia pipientis endosymbiont of the rodent filarid Litomosoides galizai.<br><br>CONCLUSIONS: We report a variety of Hepatozoon haplotypes associated with small mammals in three Brazilian biomes: Cerrado, Atlantic Forest, and Pantanal. Through phylogenetic analyses, the Hepatozoon agents grouped in the rodent-marsupial-reptile large clade of Hepatozoon spp. from the world. The detection of a W. pipientis associated with the rodent filarid L. galizai indicates that the rodent was infected by filarial nematodes.}, }
@article {pmid35286393, year = {2022}, author = {Ndiaye, EHI and Diatta, G and Diarra, AZ and Berenger, JM and Bassene, H and Mediannikov, O and Bouganali, C and Sokhna, C and Parola, P}, title = {Morphological, Molecular and MALDI-TOF MS Identification of Bedbugs and Associated Wolbachia Species in Rural Senegal.}, journal = {Journal of medical entomology}, volume = {59}, number = {3}, pages = {1019-1032}, doi = {10.1093/jme/tjac019}, pmid = {35286393}, issn = {1938-2928}, mesh = {Animals ; *Bedbugs/anatomy &amp; histology ; *Ectoparasitic Infestations ; Senegal ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; *Wolbachia ; }, abstract = {Bed bugs are known to carry several microorganisms. The purpose of this study was to assess the prevalence of bed bug infestation in two rural areas of Senegal and determine the species present in the population. A screening was conducted to detect some arthropod associated pathogenic bacteria in bed bugs and to evaluate the prevalence of endosymbiont carriage. One survey took place in 17 villages in Niakhar and two surveys in Dielmo and Ndiop and surroundings area in the same 20 villages. Bed bugs collected were identified morphologically and by MALDI-TOF MS tools. Microorganisms screening was performed by qPCR and confirmed by sequencing. During the survey in the Niakhar region, only one household 1/255 (0.4%) in the village of Ngayokhem was found infested by bed bugs. In a monitoring survey of the surroundings of Dielmo and Ndiop area, high prevalence was found during the two rounds of surveys in 65/314 (21%) in 16/20 villages (January-March) and 93/351 (26%) in 19/20 villages (December). All bed bugs were morphologically identified as the species Cimex hemipterus, of which 285/1,637 (17%) were randomly selected for MALDI-TOF MS analysis and bacteria screening. Among the Bacteria tested only Wolbachia (Alphaproteobacteria, Rickettsiales, Rickettsiaceae) DNA was found in 248/276 (90%) of the bedbugs. We briefly describe a high level of non-generalized bed bug infestation in rural Senegal and the diversity of Wolbachia strains carried by C. hemipterus. This study opens perspectives for raising household awareness of bed bug infestations and possibilities for appropriate control.}, }
@article {pmid35284894, year = {2021}, author = {Bermúdez C, SE and Félix, ML and Domínguez A, L and Kadoch, N and Muñoz-Leal, S and Venzal, JM}, title = {Molecular screening for tick-borne bacteria and hematozoa in Ixodes cf. boliviensis and Ixodes tapirus (Ixodida: Ixodidae) from western highlands of Panama.}, journal = {Current research in parasitology &amp; vector-borne diseases}, volume = {1}, number = {}, pages = {100034}, pmid = {35284894}, issn = {2667-114X}, abstract = {The first molecular screening for Rickettsia, Anaplasma, Ehrlichia, Borrelia, Babesia and Hepatozoon was carried out in questing Ixodes cf. boliviensis and Ixodes tapirus from Talamanca Mountains, Panama, using specific primers, sequencing and phylogeny. Phylogenetic analyses for the microorganisms in Ixodes cf. boliviensis confirmed the presence of Rickettsia sp. strain IbR/CRC endosymbiont (26/27 ticks), three genotypes of the Borrelia burgdorferi (sensu lato) complex (4/27 ticks), Babesia odocoilei (1/27 ticks), and Hepatozoon sp. (2/27 ticks), tentatively designated Hepatozoon sp. strain Chiriquensis. Phylogenetic analyses for the microorganisms in I. tapirus revealed an undescribed Rickettsia sp., tentatively designated Rickettsia sp. strain Itapirus LQ (6/6 ticks), and Anaplasma phagocytophilum (2/6 ticks). To the best of our knowledge, this is the first report of B. burgdorferi (s.l.) complex, A. phagocytophilum, B. odocoilei, and Hepatozoon sp. in Ixodes ticks from Central America, and also the first detection of Rickettsia spp. in Ixodes species in Panama. In light of the importance of these findings, further studies are needed focusing on the role of I. tapirus and I. cf. boliviensis as vectors, and the vertebrates acting as reservoirs.}, }
@article {pmid35283769, year = {2022}, author = {Lefoulon, E and McMullen, JG and Stock, SP}, title = {Transcriptomic Analysis of Steinernema Nematodes Highlights Metabolic Costs Associated to Xenorhabdus Endosymbiont Association and Rearing Conditions.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {821845}, pmid = {35283769}, issn = {1664-042X}, abstract = {Entomopathogenic nematodes of the genus Steinernema have a mutualistic relationship with bacteria of the genus Xenorhabdus and together they form an antagonist partnership against their insect hosts. The nematodes (third-stage infective juveniles, or IJs) protect the bacteria from the external environmental stressors and vector them from one insect host to another. Xenorhabdus produce secondary metabolites and antimicrobial compounds inside the insect that protect the cadaver from soil saprobes and scavengers. The bacteria also become the nematodes' food, allowing them to grow and reproduce. Despite these benefits, it is yet unclear what the potential metabolic costs for Steinernema IJs are relative to the maintenance and vectoring of Xenorhabdus. In this study, we performed a comparative dual RNA-seq analysis of IJs of two nematode-bacteria partnerships: Steinernema carpocapsae-Xenorhabdus nematophila and Steinernema. puntauvense-Xenorhbdus bovienii. For each association, three conditions were studied: (1) IJs reared in the insect (in vivo colonized), (2) colonized IJs reared on liver-kidney agar (in vitro colonized), and (3) IJs depleted by the bacteria reared on liver-kidney agar (in vitro aposymbiotic). Our study revealed the downregulation of numerous genes involved in metabolism pathways, such as carbohydrate, amino acid, and lipid metabolism when IJs were reared in vitro, both colonized and without the symbiont. This downregulation appears to impact the longevity pathway, with the involvement of glycogen and trehalose metabolism, as well as arginine metabolism. Additionally, a differential expression of the venom protein known to be secreted by the nematodes was observed when both Steinernema species were depleted of their symbiotic partners. These results suggest Steinernema IJs may have a mechanism to adapt their virulence in absence of their symbionts.}, }
@article {pmid35273583, year = {2022}, author = {Qin, M and Chen, J and Jiang, L and Qiao, G}, title = {Insights Into the Species-Specific Microbiota of Greenideinae (Hemiptera: Aphididae) With Evidence of Phylosymbiosis.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {828170}, pmid = {35273583}, issn = {1664-302X}, abstract = {Aphids and their symbionts represent an outstanding model for studies of insect-symbiont interactions. The aphid microbiota can be shaped by aphid species, geography and host plants. However, the relative importance of phylogenetic and ecological factors in shaping microbial community structures is not well understood. Using Illumina sequencing of the V3-V4 hypervariable region of the 16S rRNA gene, we characterized the microbial compositions of 215 aphid colonies representing 53 species of the aphid subfamily Greenideinae from different regions and plants in China, Nepal, and Vietnam. The primary endosymbiont Buchnera aphidicola and secondary symbiont Serratia symbiotica dominated the microbiota of Greenideinae. We simultaneously explored the relative contribution of host identity (i.e., aphid genus and aphid species), geography and host plant to the structures of bacterial, symbiont and secondary symbiont communities. Ordination analyses and statistical tests highlighted the strongest impact of aphid species on the microbial flora in Greenideinae. Furthermore, we found a phylosymbiosis pattern in natural Greenideinae populations, in which the aphid phylogeny was positively correlated with microbial community dissimilarities. These findings will advance our knowledge of host-associated microbiota assembly across both host phylogenetic and ecological contexts.}, }
@article {pmid35271765, year = {2022}, author = {Mao, B and Zhang, W and Zheng, Y and Li, D and Chen, MY and Wang, YF}, title = {Comparative phosphoproteomics reveal new candidates in the regulation of spermatogenesis of Drosophila melanogaster.}, journal = {Insect science}, volume = {29}, number = {6}, pages = {1703-1720}, doi = {10.1111/1744-7917.13031}, pmid = {35271765}, issn = {1744-7917}, mesh = {Female ; Male ; Animals ; *Drosophila melanogaster/genetics ; Proteomics ; Semen ; Spermatogenesis ; *Wolbachia/physiology ; Phosphoproteins ; }, abstract = {The most common phenotype induced by the endosymbiont Wolbachia in insects is cytoplasmic incompatibility, where none or fewer progenies can be produced when Wolbachia-infected males mate with uninfected females. This suggests that some modifications are induced in host sperms during spermatogenesis by Wolbachia. To identify the proteins whose phosphorylation states play essential roles in male reproduction in Drosophila melanogaster, we applied isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic strategy combined with titanium dioxide (TiO2) enrichment to compare the phosphoproteome of Wolbachia-infected with that of uninfected male reproductive systems in D. melanogaster. We identified 182 phosphopeptides, defining 140 phosphoproteins, that have at least a 1.2 fold change in abundance with a P-value of <0.05. Most of the differentially abundant phosphoproteins (DAPPs) were associated with microtubule cytoskeleton organization and spermatid differentiation. The DAPPs included proteins already known to be associated with spermatogenesis, as well as many not previously studied during this process. Six genes coding for DAPPs were knocked down, respectively, in Wolbachia-free fly testes. Among them, Slmap knockdown caused the most severe damage in spermatogenesis, with no mature sperm observed in seminal vesicles. Immunofluorescence staining showed that the formation of individualization complex composed of actin cones was completely disrupted. These results suggest that Wolbachia may induce wide changes in the abundance of phosphorylated proteins which are closely related to male reproduction. By identifying phospho-modulated proteins we also provide a significant candidate set for future studies on their roles in spermatogenesis.}, }
@article {pmid35266572, year = {2022}, author = {Matthews, ML and Covey, HO and Drolet, BS and Brelsfoard, CL}, title = {Wolbachia wAlbB inhibits bluetongue and epizootic hemorrhagic fever viruses in Culicoides midge cells.}, journal = {Medical and veterinary entomology}, volume = {36}, number = {3}, pages = {320-328}, pmid = {35266572}, issn = {1365-2915}, mesh = {Animals ; *Bluetongue ; *Bluetongue virus/physiology ; *Ceratopogonidae/physiology ; *Dengue Virus/genetics ; Real-Time Polymerase Chain Reaction/veterinary ; Sheep ; *Sheep Diseases ; *Wolbachia/genetics ; }, abstract = {Culicoides midges are hematophagous insects that transmit arboviruses of veterinary importance. These viruses include bluetongue virus (BTV) and epizootic hemorrhagic fever virus (EHDV). The endosymbiont Wolbachia pipientis Hertig spreads rapidly through insect host populations and has been demonstrated to inhibit viral pathogen transmission in multiple mosquito vectors. Here, we have demonstrated a replication inhibitory effect on BTV and EHDV in a Wolbachia (wAlbB strain)-infected Culicoides sonorensis Wirth and Jones W8 cell line. Viral replication was significantly reduced by day 5 for BTV and by day 2 for EHDV as detected by real-time polymerase chain reaction (RT-qPCR) of the non-structural NS3 gene of both viruses. Evaluation of innate cellular immune responses as a cause of the inhibitory effect showed responses associated with BTV but not with EHDV infection. Wolbachia density also did not play a role in the observed pathogen inhibitory effects, and an alternative hypothesis is suggested. Applications of Wolbachia-mediated pathogen interference to impact disease transmission by Culicoides midges are discussed.}, }
@article {pmid35264613, year = {2022}, author = {El Karkouri, K and Ghigo, E and Raoult, D and Fournier, PE}, title = {Genomic evolution and adaptation of arthropod-associated Rickettsia.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {3807}, pmid = {35264613}, issn = {2045-2322}, mesh = {Animals ; *Arthropods/genetics ; Evolution, Molecular ; *Gammaproteobacteria ; Genomics ; Phylogeny ; *Rickettsia/genetics ; *Spotted Fever Group Rickettsiosis ; }, abstract = {Rickettsia species are endosymbionts hosted by arthropods and are known to cause mild to fatal diseases in humans. Here, we analyse the evolution and diversity of 34 Rickettsia species using a pangenomic meta-analysis (80 genomes/41 plasmids). Phylogenomic trees showed that Rickettsia spp. diverged into two Spotted Fever groups, a Typhus group, a Canadensis group and a Bellii group, and may have inherited their plasmids from an ancestral plasmid that persisted in some strains or may have been lost by others. The results suggested that the ancestors of Rickettsia spp. might have infected Acari and/or Insecta and probably diverged by persisting inside and/or switching hosts. Pangenomic analysis revealed that the Rickettsia genus evolved through a strong interplay between genome degradation/reduction and/or expansion leading to possible distinct adaptive trajectories. The genus mainly shared evolutionary relationships with α-proteobacteria, and also with γ/β/δ-proteobacteria, cytophagia, actinobacteria, cyanobacteria, chlamydiia and viruses, suggesting lateral exchanges of several critical genes. These evolutionary processes have probably been orchestrated by an abundance of mobile genetic elements, especially in the Spotted Fever and Bellii groups. In this study, we provided a global evolutionary genomic view of the intracellular Rickettsia that may help our understanding of their diversity, adaptation and fitness.}, }
@article {pmid35264574, year = {2022}, author = {Klimov, PB and Chetverikov, PE and Dodueva, IE and Vishnyakov, AE and Bolton, SJ and Paponova, SS and Lutova, LA and Tolstikov, AV}, title = {Symbiotic bacteria of the gall-inducing mite Fragariocoptes setiger (Eriophyoidea) and phylogenomic resolution of the eriophyoid position among Acari.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {3811}, pmid = {35264574}, issn = {2045-2322}, mesh = {Animals ; Bacteria ; Biological Evolution ; In Situ Hybridization, Fluorescence ; *Mites/genetics ; Phylogeny ; Plants ; }, abstract = {Eriophyoid mites represent a hyperdiverse, phytophagous lineage with an unclear phylogenetic position. These mites have succeeded in colonizing nearly every seed plant species, and this evolutionary success was in part due to the mites' ability to induce galls in plants. A gall is a unique niche that provides the inducer of this modification with vital resources. The exact mechanism of gall formation is still not understood, even as to whether it is endogenic (mites directly cause galls) or exogenic (symbiotic microorganisms are involved). Here we (i) investigate the phylogenetic affinities of eriophyoids and (ii) use comparative metagenomics to test the hypothesis that the endosymbionts of eriophyoid mites are involved in gall formation. Our phylogenomic analysis robustly inferred eriophyoids as closely related to Nematalycidae, a group of deep-soil mites belonging to Endeostigmata. Our comparative metagenomics, fluorescence in situ hybridization, and electron microscopy experiments identified two candidate endosymbiotic bacteria shared across samples, however, it is unlikely that they are gall inducers (morphotype1: novel Wolbachia, morphotype2: possibly Agrobacterium tumefaciens). We also detected an array of plant pathogens associated with galls that may be vectored by the mites, and we determined a mite pathogenic virus (Betabaculovirus) that could be tested for using in biocontrol of agricultural pest mites.}, }
@article {pmid35259985, year = {2022}, author = {Perez, M and Breusing, C and Angers, B and Beinart, RA and Won, YJ and Young, CR}, title = {Divergent paths in the evolutionary history of maternally transmitted clam symbionts.}, journal = {Proceedings. Biological sciences}, volume = {289}, number = {1970}, pages = {20212137}, pmid = {35259985}, issn = {1471-2954}, mesh = {Animals ; Bacteria/genetics ; *Bivalvia/genetics ; *Gammaproteobacteria/genetics ; Genome Size ; Genome, Bacterial ; Phylogeny ; Symbiosis/genetics ; }, abstract = {Vertical transmission of bacterial endosymbionts is accompanied by virtually irreversible gene loss that results in a progressive reduction in genome size. While the evolutionary processes of genome reduction have been well described in some terrestrial symbioses, they are less understood in marine systems where vertical transmission is rarely observed. The association between deep-sea vesicomyid clams and chemosynthetic Gammaproteobacteria is one example of maternally inherited symbioses in the ocean. Here, we assessed the contributions of drift, recombination and selection to genome evolution in two extant vesicomyid symbiont clades by comparing 15 representative symbiont genomes (1.017-1.586 Mb) to those of closely related bacteria and the hosts' mitochondria. Our analyses suggest that drift is a significant force driving genome evolution in vesicomyid symbionts, though selection and interspecific recombination appear to be critical for maintaining symbiont functional integrity and creating divergent patterns of gene conservation. Notably, the two symbiont clades possess putative functional differences in sulfide physiology, anaerobic respiration and dependency on environmental vitamin B12, which probably reflect adaptations to different ecological habitats available to each symbiont group. Overall, these results contribute to our understanding of the eco-evolutionary processes shaping reductive genome evolution in vertically transmitted symbioses.}, }
@article {pmid35259567, year = {2022}, author = {Tang, J and Cai, W and Yan, Z and Zhang, K and Zhou, Z and Zhao, J and Lin, S}, title = {Interactive effects of acidification and copper exposure on the reproduction and metabolism of coral endosymbiont Cladocopium goreaui.}, journal = {Marine pollution bulletin}, volume = {177}, number = {}, pages = {113508}, doi = {10.1016/j.marpolbul.2022.113508}, pmid = {35259567}, issn = {1879-3363}, mesh = {Animals ; *Anthozoa/physiology ; Copper/metabolism/toxicity ; Coral Reefs ; Ecosystem ; Hydrogen-Ion Concentration ; Reproduction ; Seawater/chemistry ; }, abstract = {Ocean acidification resulting from increased CO2 and pollution from land-sourced toxicants such as copper have been linked to coral cover declines in coastal reef ecosystems. The impacts of ocean acidification and copper pollution on corals have been intensively investigated, whereas research on their effects on coral endosymbiont Symbiodiniaceae is limited. In this study, reproduction, photosynthetic parameters, nutrient accumulation and metabolome of Symbiodiniaceae Cladocopium goreaui were investigated after a weeklong treatment with acute CO2-induced acidification and copper ion. Acidification promoted algal reproduction through increased nutrients assimilation, upregulated citrate cycle and biomolecular biosynthesis pathway, while copper exposure repressed algal reproduction through toxic effects. The combined acidification and copper exposure caused the same decline in algal reproduction as copper exposure alone, but the upregulation of pentose phosphate pathway and the downregulation of aromatic amino acid biosynthesis. These results suggest that copper pollution could override the positive effects of acidification on the symbiodiniacean reproduction.}, }
@article {pmid35252590, year = {2021}, author = {Roquis, D and Cosseau, C and Brener Raffalli, K and Romans, P and Masanet, P and Mitta, G and Grunau, C and Vidal-Dupiol, J}, title = {The tropical coral Pocillopora acuta displays an unusual chromatin structure and shows histone H3 clipping plasticity upon bleaching.}, journal = {Wellcome open research}, volume = {6}, number = {}, pages = {195}, pmid = {35252590}, issn = {2398-502X}, abstract = {Background: Pocillopora acuta is a hermatypic coral with strong ecological importance. Anthropogenic disturbances and global warming are major threats that can induce coral bleaching, the disruption of the mutualistic symbiosis between the coral host and its endosymbiotic algae. Previous works have shown that somaclonal colonies display different levels of survival depending on the environmental conditions they previously faced. Epigenetic mechanisms are good candidates to explain this phenomenon. However, almost no work had been published on the P. acuta epigenome, especially on histone modifications. In this study, we aim at providing the first insight into chromatin structure of this species. Methods: We aligned the amino acid sequence of P. acuta core histones with histone sequences from various phyla. We developed a centri-filtration on sucrose gradient to separate chromatin from the host and the symbiont. The presence of histone H3 protein and specific histone modifications were then detected by western blot performed on histone extraction done from bleached and healthy corals. Finally, micrococcal nuclease (MNase) digestions were undertaken to study nucleosomal organization. Results: The centri-filtration enabled coral chromatin isolation with less than 2% of contamination by endosymbiont material. Histone sequences alignments with other species show that P. acuta displays on average ~90% of sequence similarities with mice and ~96% with other corals. H3 detection by western blot showed that H3 is clipped in healthy corals while it appeared to be intact in bleached corals. MNase treatment failed to provide the usual mononucleosomal digestion, a feature shared with some cnidarian, but not all; suggesting an unusual chromatin structure. Conclusions: These results provide a first insight into the chromatin, nucleosome and histone structure of P. acuta. The unusual patterns highlighted in this study and partly shared with other cnidarian will need to be further studied to better understand its role in corals.}, }
@article {pmid35255163, year = {2022}, author = {Gabr, A and Stephens, TG and Bhattacharya, D}, title = {Hypothesis: Trans-splicing Generates Evolutionary Novelty in the Photosynthetic Amoeba Paulinella.}, journal = {Journal of phycology}, volume = {58}, number = {3}, pages = {392-405}, pmid = {35255163}, issn = {1529-8817}, mesh = {*Amoeba/genetics/metabolism ; Biological Evolution ; RNA, Spliced Leader/genetics/metabolism ; *Rhizaria ; Trans-Splicing ; }, abstract = {Plastid primary endosymbiosis has occurred twice, once in the Archaeplastida ancestor and once in the Paulinella (Rhizaria) lineage. Both events precipitated massive evolutionary changes, including the recruitment and activation of genes that are horizontally acquired (HGT) and the redeployment of existing genes and pathways in novel contexts. Here we address the latter aspect in Paulinella micropora KR01 (hereafter, KR01) that has independently evolved spliced leader (SL) trans-splicing (SLTS) of nuclear-derived transcripts. We investigated the role of this process in gene regulation, novel gene origination, and endosymbiont integration. Our analysis shows that 20% of KR01 genes give rise to transcripts with at least one (but in some cases, multiple) sites of SL addition. This process, which often occurs at canonical cis-splicing acceptor sites (internal introns), results in shorter transcripts that may produce 5'-truncated proteins with novel functions. SL-truncated transcripts fall into four categories that may show: (i) altered protein localization, (ii) altered protein function, structure, or regulation, (iii) loss of valid alternative start codons, preventing translation, or (iv) multiple SL addition sites at the 5'-terminus. The SL RNA genes required for SLTS are putatively absent in the heterotrophic sister lineage of photosynthetic Paulinella species. Moreover, a high proportion of transcripts derived from genes of endosymbiotic gene transfer (EGT) and HGT origin contain SL sequences. We hypothesize that truncation of transcripts by SL addition may facilitate the generation and expression of novel gene variants and that SLTS may have enhanced the activation and fixation of foreign genes in the host genome of the photosynthetic lineages, playing a key role in primary endosymbiont integration.}, }
@article {pmid35251878, year = {2022}, author = {Pawar, MM and Shivanna, B and Prasannakumar, MK and Parivallal, PB and Suresh, K and Meenakshi, NH}, title = {Spatial distribution and community structure of microbiota associated with cowpea aphid (Aphis craccivora Koch).}, journal = {3 Biotech}, volume = {12}, number = {3}, pages = {75}, pmid = {35251878}, issn = {2190-572X}, abstract = {UNLABELLED: Aphid populations were collected on cowpea, dolichos, redgram and black gram from Belagavi and Udupi locations. The samples were shotgun sequenced using the Illumina NovaSeq 6000 system to understand the spatial distribution and community structure of microbiota (especially bacteria) associated with aphids. In the present study, we identified obligatory nutritional symbiont Buchnera aphidicola and facultative symbionts Rickettsia sp. and Bacteroidetes endosymbiont of Geopemphigus sp. in all the aphid samples studied, although in varied abundance. On the other hand, Serratia symbiotica, Arsenophonus sp. and Acinetobacter sp. were only found in aphids on specific host plants, suggesting that host plants might influence the bacterial community structure. Furthermore, our study revealed that microbiota other than bacteria were highly insignificant in the aphid populations. Additionally, functional annotation of aphid metagenomes identified several pathways and enzymes involved in various physiological and ecological functions. Amino acid and vitamin biosynthesis-related pathways were predominant than carbohydrate metabolism, owing to their feeding habit and nutritional requirement. Chaperones related to stress tolerance such as GroEL and DnaK were identified. Enzymes involved in toxic chemical metabolisms such as glutathione transferase, phosphodiesterases and ABC transferases were observed. These enzymes may confer resistance to pesticides in the aphid populations. Overall, our results support the importance of host plants in structuring bacterial communities in aphids and show the functional roles of symbionts in aphid survival and development. Thus, these findings can be the basis for further detailed investigations and devising better strategies to manage the pests in field conditions.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03142-1.}, }
@article {pmid35248159, year = {2022}, author = {Hammoud, A and Louni, M and Missé, D and Cortaredona, S and Fenollar, F and Mediannikov, O}, title = {Phylogenetic relationship between the endosymbiont "Candidatus Riesia pediculicola" and its human louse host.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {73}, pmid = {35248159}, issn = {1756-3305}, mesh = {Animals ; *Anoplura/genetics ; Biological Evolution ; Genes, Mitochondrial ; Humans ; *Pediculus/microbiology ; Phylogeny ; }, abstract = {BACKGROUND: The human louse (Pediculus humanus) is a haematophagous ectoparasite that is intimately related to its host. It has been of great public health concern throughout human history. This louse has been classified into six divergent mitochondrial clades (A, D, B, F, C and E). As with all haematophagous lice, P. humanus directly depends on the presence of a bacterial symbiont, known as "Candidatus Riesia pediculicola", to complement their unbalanced diet. In this study, we evaluated the codivergence of human lice around the world and their endosymbiotic bacteria. Using molecular approaches, we targeted lice mitochondrial genes from the six diverged clades and Candidatus Riesia pediculicola housekeeping genes.<br><br>METHODS: The mitochondrial cytochrome b gene (cytb) of lice was selected for molecular analysis, with the aim to identify louse clade. In parallel, we developed four PCR primer pairs targeting three housekeeping genes of Candidatus Riesia pediculicola: ftsZ, groEL and two regions of the rpoB gene (rpoB-1 and rpoB-2).<br><br>RESULTS: The endosymbiont phylogeny perfectly mirrored the host insect phylogeny using the ftsZ and rpoB-2 genes, in addition to showing a significant co-phylogenetic congruence, suggesting a strict vertical transmission and a host-symbiont co-speciation following the evolutionary course of the human louse.<br><br>CONCLUSION: Our results unequivocally indicate that louse endosymbionts have experienced a similar co-evolutionary history and that the human louse clade can be determined by their endosymbiotic bacteria.}, }
@article {pmid35247466, year = {2022}, author = {Bojko, J and McCoy, KA and Blakeslee, AMH}, title = {'Candidatus Mellornella promiscua' n. gen. n. sp. (Alphaproteobacteria: Rickettsiales: Anaplasmataceae): An intracytoplasmic, hepatopancreatic, pathogen of the flatback mud crab, Eurypanopeus depressus.}, journal = {Journal of invertebrate pathology}, volume = {190}, number = {}, pages = {107737}, doi = {10.1016/j.jip.2022.107737}, pmid = {35247466}, issn = {1096-0805}, mesh = {*Alphaproteobacteria/genetics ; *Anaplasmataceae/genetics ; Animals ; *Brachyura/genetics ; Ecosystem ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiales/genetics ; }, abstract = {Bacterial pathogens are a long-standing threat to the longevity and survival of crustacean hosts. Their presence and continuing emergence require close monitoring to understand their impact on fished, cultured, and wild crustacean populations. We describe a new bacterial pathogen belonging to the Anaplasmataceae family (Alphaproteobacteria: Rickettsiales), providing pathological, ultrastructural, phylogenetic, and genomic evidence to determine a candidate genus and species ('Candidatus Mellornella promiscua'). This bacterium was found to infect the mud crab, Eurypanopeus depressus, on the North Carolina coastline (USA) at a prevalence of 10.8%. 'Candidatus Mellornella promiscua' was often observed in co-infection with the rhizocephalan barnacle, Loxothylacus panopaei. The bacterium was only found in the hepatopancreas of the mud crab host, causing cytoplasmic hypertrophy, tubule necrosis, large plaques within the cytoplasm of the host cell, and an abundance of sex-pili. The circular genome of the bacterium is 1,013,119 bp and encodes 939 genes in total. Phylogenetically, the new bacterium branches within the Anaplasmataceae. The genome is dissimilar from other described bacteria, with 16S gene similarity observed at a maximum of 85.3% to a Wolbachia endosymbiont. We explore this novel bacterial pathogen using genomic, phylogenetic, ultrastructural, and pathological methods, discussing these results in light of current bacterial taxonomy, similarity to other bacterial pathogens, and the potential impact upon the surrounding disease ecology of the host and benthic ecosystem.}, }
@article {pmid35243727, year = {2022}, author = {Fujishima, M and Kodama, Y}, title = {Mechanisms for establishing primary and secondary endosymbiosis in Paramecium.}, journal = {The Journal of eukaryotic microbiology}, volume = {69}, number = {5}, pages = {e12901}, doi = {10.1111/jeu.12901}, pmid = {35243727}, issn = {1550-7408}, mesh = {*Chlorella ; *Paramecium/metabolism ; Symbiosis ; }, abstract = {Primary (eukaryote and procaryote) and secondary (eukaryote and eukaryote) endosymbioses are driving forces in eukaryotic cell evolution. These phenomena are still contributing to acquire new cell structures and functions. To understand mechanisms for establishment of each endosymbiosis, experiments that can induce endosymbiosis synchronously by mixing symbionts isolated from symbiont-bearing host cells and symbiont-free host cells are indispensable. Recent progress on endosymbiosis using Paramecium and their endonuclear symbiotic bacteria Holospora or symbiotic green alga Chlorella has been remarkable, providing excellent opportunities for elucidating host-symbiont interactions. These organisms are now becoming model organisms to know the mechanisms for establishing primary and secondary endosymbioses. Based on experiments of many researchers, we introduce how these endosymbionts escape from the host lysosomal fusion, how they migrate in the host cytoplasm to localize specific locations within the host, how their species specificity and strain specificity of the host cells are controlled, how their life cycles are controlled, how they escape from the host cell to infect more young host cell, how they affect the host viability and gene expression, what kind of substances are needed in these phenomena, and what changes had been induced in the symbiont and the host genomes.}, }
@article {pmid35237241, year = {2021}, author = {Li, J and Wei, X and Huang, D and Xiao, J}, title = {The Phylosymbiosis Pattern Between the Fig Wasps of the Same Genus and Their Associated Microbiota.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {800190}, pmid = {35237241}, issn = {1664-302X}, abstract = {Microbial communities can be critical for many metazoans, which can lead to the observation of phylosymbiosis with phylogenetically related species sharing similar microbial communities. Most of the previous studies on phylosymbiosis were conducted across the host families or genera. However, it is unclear whether the phylosymbiosis signal is still prevalent at lower taxonomic levels. In this study, 54 individuals from six species of the fig wasp genus Ceratosolen (Hymenoptera: Agaonidae) collected from nine natural populations and their associated microbiota were investigated. The fig wasp species were morphologically identified and further determined by mitochondrial CO1 gene fragments and nuclear ITS2 sequences, and the V4 region of 16S rRNA gene was sequenced to analyze the bacterial communities. The results suggest a significant positive correlation between host genetic characteristics and microbial diversity characteristics, indicating the phylosymbiosis signal between the phylogeny of insect hosts and the associated microbiota in the lower classification level within a genus. Moreover, we found that the endosymbiotic Wolbachia carried by fig wasps led to a decrease in bacterial diversity of host-associated microbial communities. This study contributes to our understanding of the role of host phylogeny, as well as the role of endosymbionts in shaping the host-associated microbial community.}, }
@article {pmid35232465, year = {2022}, author = {Marinov, GK and Chen, X and Wu, T and He, C and Grossman, AR and Kundaje, A and Greenleaf, WJ}, title = {The chromatin organization of a chlorarachniophyte nucleomorph genome.}, journal = {Genome biology}, volume = {23}, number = {1}, pages = {65}, pmid = {35232465}, issn = {1474-760X}, support = {RM1 HG007735/HG/NHGRI NIH HHS/United States ; DP2 CA228042/CA/NCI NIH HHS/United States ; U01 HG009431/HG/NHGRI NIH HHS/United States ; R01 HG008140/HG/NHGRI NIH HHS/United States ; U19 AI057266/AI/NIAID NIH HHS/United States ; P50 HG007735/HG/NHGRI NIH HHS/United States ; UM1 HG009436/HG/NHGRI NIH HHS/United States ; UM1 HG009442/HG/NHGRI NIH HHS/United States ; }, mesh = {Chromatin ; Chromosomes ; *Cryptophyta/genetics ; Eukaryota/genetics ; *Genome ; }, abstract = {BACKGROUND: Nucleomorphs are remnants of secondary endosymbiotic events between two eukaryote cells wherein the endosymbiont has retained its eukaryotic nucleus. Nucleomorphs have evolved at least twice independently, in chlorarachniophytes and cryptophytes, yet they have converged on a remarkably similar genomic architecture, characterized by the most extreme compression and miniaturization among all known eukaryotic genomes. Previous computational studies have suggested that nucleomorph chromatin likely exhibits a number of divergent features.<br><br>RESULTS: In this work, we provide the first maps of open chromatin, active transcription, and three-dimensional organization for the nucleomorph genome of the chlorarachniophyte Bigelowiella natans. We find that the B. natans nucleomorph genome exists in a highly accessible state, akin to that of ribosomal DNA in some other eukaryotes, and that it is highly transcribed over its entire length, with few signs of polymerase pausing at transcription start sites (TSSs). At the same time, most nucleomorph TSSs show very strong nucleosome positioning. Chromosome conformation (Hi-C) maps reveal that nucleomorph chromosomes interact with one other at their telomeric regions and show the relative contact frequencies between the multiple genomic compartments of distinct origin that B. natans cells contain.<br><br>CONCLUSIONS: We provide the first study of a nucleomorph genome using modern functional genomic tools, and derive numerous novel insights into the physical and functional organization of these unique genomes.}, }
@article {pmid35229443, year = {2022}, author = {Ashraf, HJ and Ramos Aguila, LC and Akutse, KS and Ilyas, M and Abbasi, A and Li, X and Wang, L}, title = {Comparative microbiome analysis of Diaphorina citri and its associated parasitoids Tamarixia radiata and Diaphorencyrtus aligarhensis reveals Wolbachia as a dominant endosymbiont.}, journal = {Environmental microbiology}, volume = {24}, number = {3}, pages = {1638-1652}, doi = {10.1111/1462-2920.15948}, pmid = {35229443}, issn = {1462-2920}, mesh = {Animals ; Bacteria ; *Citrus/microbiology ; *Hemiptera/microbiology ; *Microbiota ; *Wasps ; *Wolbachia ; }, abstract = {Microbiome analysis in a host-parasitoid interaction network was conducted to compare the taxonomic composition of bacterial communities of Diaphornia citri, Tamarixia radiata, and Diaphorencyrtus aligarhensis. The comparative analysis revealed differences in the composition and diversity of the symbiont populations across the host and its associated parasitoids. Proteobacteria was the most dominant phylum, representing 67.80% of the total bacterial community, while Candidatus Profftella armature and Wolbachia were the dominant genera across the host and parasitoids. There were clear differences observed in alpha and beta diversity of microbiota through the host and its associated parasitoids. The function prediction of bacterial communities and Pearson correlation analysis showed that specific bacterial communities displayed positive correlations with the carbohydrate metabolism pathway. Furthermore, when symbiotic bacteria were eliminated using a broad-spectrum antibiotic, tetracycline hydrochloride, the parasitoids' median survival time and longevity were significantly reduced. We confirmed the physiological effects of symbiotic bacteria on the fitness of parasitoids and demonstrated the effect of antibiotics in decreasing the food intake and measurement of amino acids in the hemolymph. This study sheds light on basic information about the mutualism between parasitoids and bacteria, which may be a potential source for biocontrol strategies for citrus psyllid, especially D. citri.}, }
@article {pmid35222085, year = {2022}, author = {Cotinat, P and Fricano, C and Toullec, G and Röttinger, E and Barnay-Verdier, S and Furla, P}, title = {Intrinsically High Capacity of Animal Cells From a Symbiotic Cnidarian to Deal With Pro-Oxidative Conditions.}, journal = {Frontiers in physiology}, volume = {13}, number = {}, pages = {819111}, pmid = {35222085}, issn = {1664-042X}, abstract = {The cnidarian-dinoflagellate symbiosis is a mutualistic intracellular association based on the photosynthetic activity of the endosymbiont. This relationship involves significant constraints and requires co-evolution processes, such as an extensive capacity of the holobiont to counteract pro-oxidative conditions induced by hyperoxia generated during photosynthesis. In this study, we analyzed the capacity of Anemonia viridis cells to deal with pro-oxidative conditions by in vivo and in vitro approaches. Whole specimens and animal primary cell cultures were submitted to 200 and 500 μM of H2O2 during 7 days. Then, we monitored global health parameters (symbiotic state, viability, and cell growth) and stress biomarkers (global antioxidant capacity, oxidative protein damages, and protein ubiquitination). In animal primary cell cultures, the intracellular reactive oxygen species (ROS) levels were also evaluated under H2O2 treatments. At the whole organism scale, both H2O2 concentrations didn't affect the survival and animal tissues exhibited a high resistance to H2O2 treatments. Moreover, no bleaching has been observed, even at high H2O2 concentration and after long exposure (7 days). Although, the community has suggested the role of ROS as the cause of bleaching, our results indicating the absence of bleaching under high H2O2 concentration may exculpate this specific ROS from being involved in the molecular processes inducing bleaching. However, counterintuitively, the symbiont compartment appeared sensitive to an H2O2 burst as it displayed oxidative protein damages, despite an enhancement of antioxidant capacity. The in vitro assays allowed highlighting an intrinsic high capacity of isolated animal cells to deal with pro-oxidative conditions, although we observed differences on tolerance between H2O2 treatments. The 200 μM H2O2 concentration appeared to correspond to the tolerance threshold of animal cells. Indeed, no disequilibrium on redox state was observed and only a cell growth decrease was measured. Contrarily, the 500 μM H2O2 concentration induced a stress state, characterized by a cell viability decrease from 1 day and a drastic cell growth arrest after 7 days leading to an uncomplete recovery after treatment. In conclusion, this study highlights the overall high capacity of cnidarian cells to cope with H2O2 and opens new perspective to investigate the molecular mechanisms involved in this peculiar resistance.}, }
@article {pmid35215074, year = {2022}, author = {Kumar, D and Downs, LP and Adegoke, A and Machtinger, E and Oggenfuss, K and Ostfeld, RS and Embers, M and Karim, S}, title = {An Exploratory Study on the Microbiome of Northern and Southern Populations of Ixodes scapularis Ticks Predicts Changes and Unique Bacterial Interactions.}, journal = {Pathogens (Basel, Switzerland)}, volume = {11}, number = {2}, pages = {}, pmid = {35215074}, issn = {2076-0817}, support = {P20 GM103476/GM/NIGMS NIH HHS/United States ; }, abstract = {The black-legged tick (Ixodes scapularis) is the primary vector of Borrelia burgdorferi, the causative agent of Lyme disease in North America. However, the prevalence of Lyme borreliosis is clustered around the Northern States of the United States of America. This study utilized a metagenomic sequencing approach to compare the microbial communities residing within Ix. scapularis populations from northern and southern geographic locations in the USA. Using a SparCC network construction model, we performed potential interactions between members of the microbial communities from Borrelia burgdorferi-infected tissues of unfed and blood-fed ticks. A significant difference in bacterial composition and diversity was found between northern and southern tick populations. The network analysis predicted a potential antagonistic interaction between endosymbiont Rickettsia buchneri and Borrelia burgdorferi sensu lato. The network analysis, as expected, predicted significant positive and negative microbial interactions in ticks from these geographic regions, with the genus Rickettsia, Francisella, and Borreliella playing an essential role in the identified clusters. Interactions between Rickettsia buchneri and Borrelia burgdorferi sensu lato need more validation and understanding. Understanding the interplay between the microbiome and tick-borne pathogens within tick vectors may pave the way for new strategies to prevent tick-borne infections.}, }
@article {pmid35211975, year = {2022}, author = {Gabr, A and Zournas, A and Stephens, TG and Dismukes, GC and Bhattacharya, D}, title = {Evidence for a robust photosystem II in the photosynthetic amoeba Paulinella.}, journal = {The New phytologist}, volume = {234}, number = {3}, pages = {934-945}, doi = {10.1111/nph.18052}, pmid = {35211975}, issn = {1469-8137}, mesh = {*Amoeba/genetics ; *Chromatophores ; Light ; Photosynthesis/genetics ; Photosystem II Protein Complex ; Phylogeny ; }, abstract = {Paulinella represents the only known case of an independent primary plastid endosymbiosis, outside Archaeplastida, that occurred c. 120 (million years ago) Ma. These photoautotrophs grow very slowly in replete culture medium with a doubling time of 6-7 d at optimal low light, and are highly sensitive to photodamage under moderate light levels. We used genomic and biophysical methods to investigate the extreme slow growth rate and light sensitivity of Paulinella, which are key to photosymbiont integration. All photosystem II (PSII) genes except psb28-2 and all cytochrome b6 f complex genes except petM and petL are present in Paulinella micropora KR01 (hereafter, KR01). Biophysical measurements of the water oxidation complex, variable chlorophyll fluorescence, and photosynthesis-irradiance curves show no obvious evidence of PSII impairment. Analysis of photoacclimation under high-light suggests that although KR01 can perform charge separation, it lacks photoprotection mechanisms present in cyanobacteria. We hypothesize that Paulinella species are restricted to low light environments because they are deficient in mitigating the formation of reactive oxygen species formed within the photosystems under peak solar intensities. The finding that many photoprotection genes have been lost or transferred to the host-genome during endosymbiont genome reduction, and may lack light-regulation, is consistent with this hypothesis.}, }
@article {pmid35208930, year = {2022}, author = {Liu, X and Zhao, J and Jiang, P}, title = {Easy Removal of Epiphytic Bacteria on Ulva (Ulvophyceae, Chlorophyta) by Vortex with Silica Sands.}, journal = {Microorganisms}, volume = {10}, number = {2}, pages = {}, pmid = {35208930}, issn = {2076-2607}, abstract = {Macroalgae-associated bacteria play an important role in their algal hosts' biological processes. They are localized on surfaces of the host thalli, as well as between and even within algal cells. To examine the differences in community structures and functions between epi- and endo- bacteria, an effective approach for maximizing epiphyte removal from delicate seaweeds while retaining endophyte fidelity must be developed. In this study, a variety of surface sterilization methods for Ulva prolifera were compared, including mechanical, chemical, and enzymatical treatments. According to the results of scanning electron microscope (SEM) and denaturing gradient gel electrophoresis (DGGE) analysis, almost complete removal of epiphytic bacteria on Ulva was obtained simply by co-vortex of seaweeds with silica sands, causing minimal disturbance to endosymbionts when compared to previous published methods. In addition, the adaptability was also confirmed in additional U. prolifera strains and Ulva species with blade-like or narrow tubular thallus shapes. This easy mechanical method would enable the analysis of community composition and host specificity for Ulva-associated epi- and endo-bacteria separately.}, }
@article {pmid35207577, year = {2022}, author = {Latorre, A and Domínguez-Santos, R and García-Ferris, C and Gil, R}, title = {Of Cockroaches and Symbionts: Recent Advances in the Characterization of the Relationship between Blattella germanica and Its Dual Symbiotic System.}, journal = {Life (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, pmid = {35207577}, issn = {2075-1729}, abstract = {Mutualistic stable symbioses are widespread in all groups of eukaryotes, especially in insects, where symbionts have played an essential role in their evolution. Many insects live in obligate relationship with different ecto- and endosymbiotic bacteria, which are needed to maintain their hosts' fitness in their natural environment, to the point of even relying on them for survival. The case of cockroaches (Blattodea) is paradigmatic, as both symbiotic systems coexist in the same organism in two separated compartments: an intracellular endosymbiont (Blattabacterium) inside bacteriocytes located in the fat body, and a rich and complex microbiota in the hindgut. The German cockroach Blattella germanica is a good model for the study of symbiotic interactions, as it can be maintained in the laboratory in controlled populations, allowing the perturbations of the two symbiotic systems in order to study the communication and integration of the tripartite organization of the host-endosymbiont-microbiota, and to evaluate the role of symbiotic antimicrobial peptides (AMPs) in host control over their symbionts. The importance of cockroaches as reservoirs and transmission vectors of antibiotic resistance sequences, and their putative interest to search for AMPs to deal with the problem, is also discussed.}, }
@article {pmid35196357, year = {2022}, author = {Ross, PA and Robinson, KL and Yang, Q and Callahan, AG and Schmidt, TL and Axford, JK and Coquilleau, MP and Staunton, KM and Townsend, M and Ritchie, SA and Lau, MJ and Gu, X and Hoffmann, AA}, title = {A decade of stability for wMel Wolbachia in natural Aedes aegypti populations.}, journal = {PLoS pathogens}, volume = {18}, number = {2}, pages = {e1010256}, pmid = {35196357}, issn = {1553-7374}, mesh = {*Aedes ; Animals ; *Arboviruses ; Australia ; *Wolbachia/genetics ; }, abstract = {Mosquitoes carrying Wolbachia endosymbionts are being released in many countries for arbovirus control. The wMel strain of Wolbachia blocks Aedes-borne virus transmission and can spread throughout mosquito populations by inducing cytoplasmic incompatibility. Aedes aegypti mosquitoes carrying wMel were first released into the field in Cairns, Australia, over a decade ago, and with wider releases have resulted in the near elimination of local dengue transmission. The long-term stability of Wolbachia effects is critical for ongoing disease suppression, requiring tracking of phenotypic and genomic changes in Wolbachia infections following releases. We used a combination of field surveys, phenotypic assessments, and Wolbachia genome sequencing to show that wMel has remained stable in its effects for up to a decade in Australian Ae. aegypti populations. Phenotypic comparisons of wMel-infected and uninfected mosquitoes from near-field and long-term laboratory populations suggest limited changes in the effects of wMel on mosquito fitness. Treating mosquitoes with antibiotics used to cure the wMel infection had limited effects on fitness in the next generation, supporting the use of tetracycline for generating uninfected mosquitoes without off-target effects. wMel has a temporally stable within-host density and continues to induce complete cytoplasmic incompatibility. A comparison of wMel genomes from pre-release (2010) and nine years post-release (2020) populations show few genomic differences and little divergence between release locations, consistent with the lack of phenotypic changes. These results indicate that releases of Wolbachia-infected mosquitoes for population replacement are likely to be effective for many years, but ongoing monitoring remains important to track potential evolutionary changes.}, }
@article {pmid35194678, year = {2022}, author = {Dos Santos, DL and Virginio, VG and Berté, FK and Lorenzatto, KR and Marinho, DR and Kwitko, S and Locatelli, CI and Freitas, EC and Rott, MB}, title = {Clinical and molecular diagnosis of Acanthamoeba keratitis in contact lens wearers in southern Brazil reveals the presence of an endosymbiont.}, journal = {Parasitology research}, volume = {121}, number = {5}, pages = {1447-1454}, pmid = {35194678}, issn = {1432-1955}, mesh = {*Acanthamoeba/genetics ; *Acanthamoeba Keratitis/diagnosis/etiology ; *Amebiasis/complications ; Brazil ; *Contact Lenses/adverse effects ; Genotype ; Humans ; }, abstract = {Acanthamoeba keratitis (AK) is an infection that is mostly observed in contact lens wearers. It is often misdiagnosed causing delays in the administration of the correct treatment. The aim of this study was to report the outcome of clinical and molecular diagnosis of AK cases during the summer of 2019 in the southern region of Brazil. Three suspected cases of AK were discovered after an ophthalmic examination at a public hospital in the city of Porto Alegre. These cases were then confirmed through laboratory diagnosis (cell culture and molecular analysis by PCR and sequencing). In each of the three clinical sample cell cultures of corneal scraping and molecular analysis confirmed the presence of Acanthamoeba spp., all belonging to the morphological group II and to the genotype T4, which is the most common genotype associated with AK. In addition, Acanthamoeba spp. isolated from one of the clinical samples was found to harbor the Candidatus Paracaedibacter acanthamoeba, a bacterial endosymbiont. The presence of Ca. Paracaedibacter acanthamoeba in clinical isolates requires further research to reveal its possible role in the pathogenicity of Acanthamoeba infections.}, }
@article {pmid35192040, year = {2022}, author = {Detcharoen, M and Nilsai, A}, title = {Low Endosymbiont Incidence in Drosophila Species Across Peninsula Thailand.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {35192040}, issn = {1432-184X}, abstract = {Arthropods are known to harbor several endosymbionts, such as Cardinium, Rickettsia, Spiroplasma, and Wolbachia. Wolbachia, for example, are the most widespread known endosymbionts in the world, which are found in about half of all arthropod species. To increase their transmission, these endosymbionts must manipulate their hosts in several ways such as cytoplasmic incompatibility and male killing. In tropical regions, endosymbiont diversity has not been studied exhaustively. Here, we checked four endosymbionts, including Cardinium, Rickettsia, Spiroplasma, and Wolbachia, in eleven Drosophila species found in Thai Peninsula. The Wolbachia strain wRi-like was found in all populations of Drosophila ananassae and Drosophila simulans. Furthermore, we found two new strains, wMalA and wMalB, in two populations of Drosophila malerkotliana. Besides Wolbachia, we did not find any of the above endosymbionts in all fly species. This work reveals the hidden diversity of endosymbionts in Drosophila and is the first exhaustive study on Drosophila in the region.}, }
@article {pmid35190334, year = {2022}, author = {Yessinou, RE and Katja, MS and Heinrich, N and Farougou, S}, title = {Prevalence of Coxiella-infections in ticks - review and meta-analysis.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {3}, pages = {101926}, doi = {10.1016/j.ttbdis.2022.101926}, pmid = {35190334}, issn = {1877-9603}, mesh = {Animals ; Coxiella/genetics ; *Coxiella burnetii/genetics ; Prevalence ; *Q Fever/epidemiology/microbiology/veterinary ; *Ticks/microbiology ; }, abstract = {Q fever is a global zoonotic infection caused by the intracellular Gram-negative bacterium Coxiella burnetii. Historically, it is considered a vector-borne disease, but the role of ticks in transmission has not fully been elucidated yet. Excretion of C. burnetii in tick feces and saliva is well documented but the role of these findings or the epidemiological context is discussed controversially. Thus, the aim of this study was to determine the prevalence of C. burnetii DNA in ticks to clarify the potential role of tick species for maintenance of C. burnetii infection. A literature review was performed using Google scholar, Agora, Science Direct, PubMed and Scopus to identify original studies on C. burnetii DNA presence in ticks. The search was limited to literature published from 2009 to 2020 in English and French and focused on data obtained by molecular detection of C. burnetii DNA in ticks. Overall, the prevalence of C. burnetii in ticks collected in Africa varied from 2.91% to 13.97%, in Europe from 2.46% to 10.52% and the Middle East from 4.76% to 12.53%. Ticks collected from animals showed a prevalence of 8% (95% CI: 6%-10%), followed by ticks collected from the environment and animals of 7% (95% CI: 5%-10%). C. burnetii DNA has been found in samples of many tick species with the highest prevalence in Rhipicephalus evertsi and Amblyomma variegatum. However, most of these studies did not include a differentiation between C. burnetii and Coxiella-like endosymbionts making it finally difficult to estimate the potential role that ticks play in the epidemiology of Q fever. Therefore, it is necessary to analyze the vector competence of different tick species to transmit C. burnetii. Knowledge of the vector and reservoir competence of ticks is important for taking adequate preventive measures to limit infection risks.}, }
@article {pmid35186508, year = {2022}, author = {Lefoulon, E and Campbell, N and Stock, SP}, title = {Identification of novel prophage regions in Xenorhabdus nematophila genome and gene expression analysis during phage-like particle induction.}, journal = {PeerJ}, volume = {10}, number = {}, pages = {e12956}, pmid = {35186508}, issn = {2167-8359}, abstract = {BACKGROUND: Entomopathogenic Xenorhabdus bacteria are endosymbionts of Steinernema nematodes and together they form an insecticidal mutualistic association that infects a wide range of insect species. Xenorhabdus produce an arsenal of toxins and secondary metabolites that kill the insect host. In addition, they can induce the production of diverse phage particles. A few studies have focused on one integrated phage responsible for producing a phage tail-like bacteriocin, associated with an antimicrobial activity against other Xenorhabdus species. However, very little is known about the diversity of prophage regions in Xenorhabdus species.<br><br>METHODS: In the present study, we identified several prophage regions in the genome of Xenorhabdus nematophila AN6/1. We performed a preliminary study on the relative expression of genes in these prophage regions. We also investigated some genes (not contained in prophage region) known to be involved in SOS bacterial response (recA and lexA) associated with mitomycin C and UV exposure.<br><br>RESULTS: We described two integrated prophage regions (designated Xnp3 and Xnp4) not previously described in the genome of Xenorhabdus nematophila AN6/1. The Xnp3 prophage region appears very similar to complete Mu-like bacteriophage. These prophages regions are not unique to X. nematophila species, although they appear less conserved among Xenorhabdus species when compared to the previously described p1 prophage region. Our results showed that mitomycin C exposure induced an up-regulation of recA and lexA suggesting activation of SOS response. In addition, mitomycin C and UV exposure seems to lead to up-regulation of genes in three of the four integrated prophages regions.}, }
@article {pmid35183553, year = {2022}, author = {Konecka, E}, title = {Fifty shades of bacterial endosymbionts and some of them still remain a mystery: Wolbachia and Cardinium in oribatid mites (Acari: Oribatida).}, journal = {Journal of invertebrate pathology}, volume = {189}, number = {}, pages = {107733}, doi = {10.1016/j.jip.2022.107733}, pmid = {35183553}, issn = {1096-0805}, mesh = {Animals ; Bacteria ; Bacteroidetes ; *Mites/microbiology ; Phylogeny ; *Wolbachia ; }, abstract = {Wolbachia is the most abundant intracellular symbiont among terrestrial Arthropoda. This bacterium together with other microorganisms, i.e., Cardinium, gained fame mainly as the causative agent of host sex-ratio distortion. Across the impressive diversity of oribatid mites (Acari: Oribatida), the microbes have been found in both parthenogenetic (Oppiella nova, Ceratozetes thienemanni, Hypochthonius rufulus) as well as sexually-reproducing (Gustavia microcephala, Achipteria coleoptrata, Microzetorchestes emeryi, Damaeus onustus) species. Wolbachia found in Oribatida represents supergroup E and is related to bacterial endosymbionts of springtails (Hexapoda: Collembola). Cardinium identified in O. nova and M. emeryi belongs to phylogenetic group A. In turn, Cardinium from A. coleoptrata constitutes a new separate group E. The occurrence of these bacterial endosymbionts in parthenogenetic and sexual oribatid mites species may suggests a different function other than manipulating host reproduction. Indeed, endosymbionts may have various "shades" of functions in invertebrate hosts, some of which cannot be excluded in the oribatid mites, e.g., enriching a nutrient-limited diet with B vitamins or contributing to host adaptation to colder and harsher climates. Nevertheless, the mystery behind the roles of bacteria in Oribatida still needs required to be unraveled.}, }
@article {pmid35175127, year = {2022}, author = {Gharabigloozare, Y and Wähling, A and Bleidorn, C}, title = {Whole-Genome Sequence of the Wolbachia Strain wTcon, an Endosymbiont of the Confused Flour Beetle, Tribolium confusum.}, journal = {Microbiology resource announcements}, volume = {11}, number = {2}, pages = {e0114421}, pmid = {35175127}, issn = {2576-098X}, abstract = {Up to 60% of insects are infected with symbiont intracellular alphaproteobacteria of the genus Wolbachia, which are often able to manipulate their host's reproduction. Here, we report the annotated draft genome sequence of strain wTcon from the confused flour beetle, Tribolium confusum, based on long- and short-read sequence data. The assembled genome is located on 12 contigs with a total size of 1,418,452 bp.}, }
@article {pmid35172009, year = {2022}, author = {Rutins, I and Schannauer, S and Orellana, S and Laukhuff, H and Lang, E and Becker, T and McKinney, E and Thomas, K and Tilden, V and Swartz, M and Blair, JE}, title = {Genetic Diversity and Wolbachia (Rickettsiales: Anaplasmataceae) Prevalence Within a Remnant Population of Regal Fritillary, Argynnis idalia (Lepidoptera: Nymphalidae), in South-Central Pennsylvania.}, journal = {Journal of insect science (Online)}, volume = {22}, number = {1}, pages = {}, pmid = {35172009}, issn = {1536-2442}, mesh = {Animals ; *Butterflies/genetics/microbiology ; Female ; Genetic Variation ; Pennsylvania ; Prevalence ; United States ; *Wolbachia/genetics ; }, abstract = {Eastern populations of the North American regal fritillary, Argynnis idalia Drury (1773), have been largely extirpated over the past half century. Here we report on the last remaining population of eastern regal fritillaries, located within a military installation in south-central Pennsylvania. Samples were obtained from field specimens during two years of annual monitoring, and from females collected for captive rearing over a five year period. Nuclear microsatellite and mitochondrial sequence data do not suggest subdivision within this population, but excess nuclear homozygosity indicates negative impacts on genetic diversity likely due to small population size and potential inbreeding effects. Molecular assays did not detect Wolbachia endosymbionts in field specimens of regal fritillary, but sympatric Argynnis sister species showed high prevalence of Wolbachia infected individuals. Our results inform ongoing conservation and reintroduction projects, designed to protect the last remaining regal fritillary population from extirpation in the eastern United States.}, }
@article {pmid35171977, year = {2022}, author = {Gagalova, KK and Whitehill, JGA and Culibrk, L and Lin, D and Lévesque-Tremblay, V and Keeling, CI and Coombe, L and Yuen, MMS and Birol, I and Bohlmann, J and Jones, SJM}, title = {The genome of the forest insect pest Pissodes strobi reveals genome expansion and evidence of a Wolbachia endosymbiont.}, journal = {G3 (Bethesda, Md.)}, volume = {12}, number = {4}, pages = {}, pmid = {35171977}, issn = {2160-1836}, mesh = {Animals ; Forests ; Insecta ; *Picea/genetics ; *Weevils/genetics ; *Wolbachia/genetics ; }, abstract = {The highly diverse insect family of true weevils, Curculionidae, includes many agricultural and forest pests. Pissodes strobi, commonly known as the spruce weevil or white pine weevil, is a major pest of spruce and pine forests in North America. Pissodes strobi larvae feed on the apical shoots of young trees, causing stunted growth and can destroy regenerating spruce or pine forests. Here, we describe the nuclear and mitochondrial Pissodes strobi genomes and their annotations, as well as the genome of an apparent Wolbachia endosymbiont. We report a substantial expansion of the weevil nuclear genome, relative to other Curculionidae species, possibly driven by an abundance of class II DNA transposons. The endosymbiont observed belongs to a group (supergroup A) of Wolbachia species that generally form parasitic relationships with their arthropod host.}, }
@article {pmid35170217, year = {2022}, author = {Breusing, C and Castel, J and Yang, Y and Broquet, T and Sun, J and Jollivet, D and Qian, PY and Beinart, RA}, title = {Global 16S rRNA diversity of provannid snail endosymbionts from Indo-Pacific deep-sea hydrothermal vents.}, journal = {Environmental microbiology reports}, volume = {14}, number = {2}, pages = {299-307}, pmid = {35170217}, issn = {1758-2229}, mesh = {Animals ; Ecosystem ; *Hydrothermal Vents/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Snails/microbiology ; Symbiosis ; }, abstract = {Symbioses between invertebrate animals and chemosynthetic bacteria build the foundation of deep-sea hydrothermal ecosystems worldwide. Despite the importance of these symbioses for ecosystem functioning, the diversity of symbionts within and between host organisms and geographic regions is still poorly understood. In this study we used 16S rRNA amplicon sequencing to determine the diversity of gill endosymbionts in provannid snails of the genera Alviniconcha and Ifremeria, which are key species at deep-sea hydrothermal vents in the Indo-Pacific Ocean. Our analysis of 761 snail samples across the distributional range of these species confirms previous findings that symbiont lineages are strongly partitioned by host species and broad-scale geography. Less structuring was observed within geographic regions, probably due to insufficient strain resolution of the 16S rRNA gene. Symbiont richness in individual hosts appeared to be unrelated to host size, suggesting that provannid snails might acquire their symbionts only during a permissive time window in early developmental stages in contrast to other vent molluscs that obtain their symbionts throughout their lifetime. Despite the extent of our dataset, symbiont accumulation curves did not reach saturation, highlighting the need for increased sampling efforts to uncover the full diversity of symbionts within these and other hydrothermal vent species.}, }
@article {pmid35163495, year = {2022}, author = {Fish, M and Nash, D and German, A and Overton, A and Jelokhani-Niaraki, M and Chuong, SDX and Smith, MD}, title = {New Insights into the Chloroplast Outer Membrane Proteome and Associated Targeting Pathways.}, journal = {International journal of molecular sciences}, volume = {23}, number = {3}, pages = {}, pmid = {35163495}, issn = {1422-0067}, mesh = {Chloroplast Proteins/chemistry/*metabolism ; Chloroplasts/*metabolism ; Intracellular Membranes/*metabolism ; Protein Transport ; Proteome/*metabolism ; Signal Transduction ; }, abstract = {Plastids are a dynamic class of organelle in plant cells that arose from an ancient cyanobacterial endosymbiont. Over the course of evolution, most genes encoding plastid proteins were transferred to the nuclear genome. In parallel, eukaryotic cells evolved a series of targeting pathways and complex proteinaceous machinery at the plastid surface to direct these proteins back to their target organelle. Chloroplasts are the most well-characterized plastids, responsible for photosynthesis and other important metabolic functions. The biogenesis and function of chloroplasts rely heavily on the fidelity of intracellular protein trafficking pathways. Therefore, understanding these pathways and their regulation is essential. Furthermore, the chloroplast outer membrane proteome remains relatively uncharted territory in our understanding of protein targeting. Many key players in the cytosol, receptors at the organelle surface, and insertases that facilitate insertion into the chloroplast outer membrane remain elusive for this group of proteins. In this review, we summarize recent advances in the understanding of well-characterized chloroplast outer membrane protein targeting pathways as well as provide new insights into novel targeting signals and pathways more recently identified using a bioinformatic approach. As a result of our analyses, we expand the known number of chloroplast outer membrane proteins from 117 to 138.}, }
@article {pmid35163408, year = {2022}, author = {Bueno, E and Mania, D and Mesa, S and Bedmar, EJ and Frostegård, &#xc5; and Bakken, LR and Delgado, MJ}, title = {Regulation of the Emissions of the Greenhouse Gas Nitrous Oxide by the Soybean Endosymbiont Bradyrhizobium diazoefficiens.}, journal = {International journal of molecular sciences}, volume = {23}, number = {3}, pages = {}, pmid = {35163408}, issn = {1422-0067}, mesh = {Bradyrhizobium/*metabolism ; Greenhouse Gases/*metabolism ; Nitrous Oxide/*metabolism ; Soybeans/*microbiology ; *Symbiosis ; }, abstract = {The greenhouse gas nitrous oxide (N2O) has strong potential to drive climate change. Soils are a major source of N2O, with microbial nitrification and denitrification being the primary processes involved in such emissions. The soybean endosymbiont Bradyrhizobium diazoefficiens is a model microorganism to study denitrification, a process that depends on a set of reductases, encoded by the napEDABC, nirK, norCBQD, and nosRZDYFLX genes, which sequentially reduce nitrate (NO3[-]) to nitrite (NO2[-]), nitric oxide (NO), N2O, and dinitrogen (N2). In this bacterium, the regulatory network and environmental cues governing the expression of denitrification genes rely on the FixK2 and NnrR transcriptional regulators. To understand the role of FixK2 and NnrR proteins in N2O turnover, we monitored real-time kinetics of NO3[-], NO2[-], NO, N2O, N2, and oxygen (O2) in a fixK2 and nnrR mutant using a robotized incubation system. We confirmed that FixK2 and NnrR are regulatory determinants essential for NO3[-] respiration and N2O reduction. Furthermore, we demonstrated that N2O reduction by B. diazoefficiens is independent of canonical inducers of denitrification, such as the nitrogen oxide NO3[-], and it is negatively affected by acidic and alkaline conditions. These findings advance the understanding of how specific environmental conditions and two single regulators modulate N2O turnover in B. diazoefficiens.}, }
@article {pmid35162074, year = {2022}, author = {Skinner, KM and Underwood, J and Ghosh, A and Oliva Chavez, AS and Brelsfoard, CL}, title = {Wolbachia Impacts Anaplasma Infection in Ixodes scapularis Tick Cells.}, journal = {International journal of environmental research and public health}, volume = {19}, number = {3}, pages = {}, pmid = {35162074}, issn = {1660-4601}, mesh = {*Anaplasma phagocytophilum ; *Anaplasmosis ; Animals ; Host-Pathogen Interactions ; *Ixodes/microbiology ; *Wolbachia ; }, abstract = {The specific interactions of members of tick bacterial microbiota and their effects on pathogen transmission remains relatively unexplored. Here, we introduced a novel Wolbachia infection type into Ixodes scapularis tick cells and examined the antipathogenic effects on the intracellular pathogen Anaplasma phagocytophilum. An increase in A. phagocytophilum replication was observed in Wolbachia-infected tick cells. However, Wolbachia infection densities decreased when cells were serially passaged and ultimately the infection was lost. Host-cell immune response was also examined as an additional factor that could have affected A. phagocytophilum replication in Wolbachia-infected cells. In early passages post-Wolbachia infection, a decreased immune response was observed, but in later passages of cells with low Wolbachia densities, there was no change in the immune response. The results are discussed in relation to the importance of studying the interactions of the tick microbiota, the host cell, and the pathogen and the development of novel tick and tick-borne disease-control approaches.}, }
@article {pmid35145076, year = {2022}, author = {Schvarcz, CR and Wilson, ST and Caffin, M and Stancheva, R and Li, Q and Turk-Kubo, KA and White, AE and Karl, DM and Zehr, JP and Steward, GF}, title = {Overlooked and widespread pennate diatom-diazotroph symbioses in the sea.}, journal = {Nature communications}, volume = {13}, number = {1}, pages = {799}, pmid = {35145076}, issn = {2041-1723}, mesh = {Cyanobacteria/physiology ; Diatoms/classification/genetics/isolation &amp; purification/*physiology ; Ecosystem ; Nitrogen ; Nitrogen Fixation ; Pacific Ocean ; Phylogeny ; Seawater/*microbiology ; *Symbiosis ; }, abstract = {Persistent nitrogen depletion in sunlit open ocean waters provides a favorable ecological niche for nitrogen-fixing (diazotrophic) cyanobacteria, some of which associate symbiotically with eukaryotic algae. All known marine examples of these symbioses have involved either centric diatom or haptophyte hosts. We report here the discovery and characterization of two distinct marine pennate diatom-diazotroph symbioses, which until now had only been observed in freshwater environments. Rhopalodiaceae diatoms Epithemia pelagica sp. nov. and Epithemia catenata sp. nov. were isolated repeatedly from the subtropical North Pacific Ocean, and analysis of sequence libraries reveals a global distribution. These symbioses likely escaped attention because the endosymbionts lack fluorescent photopigments, have nifH gene sequences similar to those of free-living unicellular cyanobacteria, and are lost in nitrogen-replete medium. Marine Rhopalodiaceae-diazotroph symbioses are a previously overlooked but widespread source of bioavailable nitrogen in marine habitats and provide new, easily cultured model organisms for the study of organelle evolution.}, }
@article {pmid35134329, year = {2022}, author = {Itabangi, H and Sephton-Clark, PCS and Tamayo, DP and Zhou, X and Starling, GP and Mahamoud, Z and Insua, I and Probert, M and Correia, J and Moynihan, PJ and Gebremariam, T and Gu, Y and Ibrahim, AS and Brown, GD and King, JS and Ballou, ER and Voelz, K}, title = {A bacterial endosymbiont of the fungus Rhizopus microsporus drives phagocyte evasion and opportunistic virulence.}, journal = {Current biology : CB}, volume = {32}, number = {5}, pages = {1115-1130.e6}, pmid = {35134329}, issn = {1879-0445}, support = {MR/N006364/2/MRC_/Medical Research Council/United Kingdom ; MR/V033417/1/MRC_/Medical Research Council/United Kingdom ; 108387/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; 097377/WT_/Wellcome Trust/United Kingdom ; BB/M01116X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/S010122/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; R01 AI063503/AI/NIAID NIH HHS/United States ; 102705/WT_/Wellcome Trust/United Kingdom ; BB/M014525/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 211241/Z/18/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {*Amoeba ; Animals ; Bacteria ; *Dictyostelium ; Fungi ; Humans ; Mammals ; Mice ; Phagocytes ; Rhizopus ; Virulence ; Zebrafish ; }, abstract = {Opportunistic infections by environmental fungi are a growing clinical problem, driven by an increasing population of people with immunocompromising conditions. Spores of the Mucorales order are ubiquitous in the environment but can also cause acute invasive infections in humans through germination and evasion of the mammalian host immune system. How they achieve this and the evolutionary drivers underlying the acquisition of virulence mechanisms are poorly understood. Here, we show that a clinical isolate of Rhizopus microsporus contains a Ralstonia pickettii bacterial endosymbiont required for virulence in both zebrafish and mice and that this endosymbiosis enables the secretion of factors that potently suppress growth of the soil amoeba Dictyostelium discoideum, as well as their ability to engulf and kill other microbes. As amoebas are natural environmental predators of both bacteria and fungi, we propose that this tri-kingdom interaction contributes to establishing endosymbiosis and the acquisition of anti-phagocyte activity. Importantly, we show that this activity also protects fungal spores from phagocytosis and clearance by human macrophages, and endosymbiont removal renders the fungal spores avirulent in vivo. Together, these findings describe a new role for a bacterial endosymbiont in Rhizopus microsporus pathogenesis in animals and suggest a mechanism of virulence acquisition through environmental interactions with amoebas.}, }
@article {pmid35134189, year = {2022}, author = {Grodowitz, MJ and Gundersen-Rindal, DE and Elliott, B and Evans, R and Sparks, ME and Reed, DA and Miles, GP and Allen, ML and Perring, TM}, title = {Trypanosomatids Associated in the Alimentary Canal of Bagrada hilaris (Hemiptera: Pentatomidae).}, journal = {Journal of insect science (Online)}, volume = {22}, number = {1}, pages = {}, pmid = {35134189}, issn = {1536-2442}, mesh = {Animals ; *Hemiptera/parasitology ; *Trypanosoma/classification ; }, abstract = {Bagrada hilaris (Burmeister) is an invasive pest of economically important crops in the United States. During physiological investigations of B. hilaris, a flagellated protozoan was discovered in the alimentary canal of many specimens. This manuscript characterizes the morphology and molecular identification of the trypanosomatid, which appears similar to trypanosomatids identified in other stink bug species. It has been identified as a species in the Blastocrithidia genus based on morphological characteristics and molecular analyses.}, }
@article {pmid35132118, year = {2022}, author = {Scharfenstein, HJ and Chan, WY and Buerger, P and Humphrey, C and van Oppen, MJH}, title = {Evidence for de novo acquisition of microalgal symbionts by bleached adult corals.}, journal = {The ISME journal}, volume = {16}, number = {6}, pages = {1676-1679}, pmid = {35132118}, issn = {1751-7370}, mesh = {Animals ; *Anthozoa/genetics ; Coral Reefs ; *Dinoflagellida/genetics ; *Microalgae ; Symbiosis ; }, abstract = {Early life stages of most coral species acquire microalgal endosymbionts (Symbiodiniaceae) from the environment, but whether exogenous symbiont uptake is possible in the adult life stage is unclear. Deep sequencing of the Symbiodiniaceae ITS2 genetic marker has revealed novel symbionts in adult corals following bleaching; however these strains may have already been present at densities below detection limits. To test whether acquisition of symbionts from the environment occurs, we subjected adult fragments of corals (six species in four families) to a chemical bleaching treatment (menthol and DCMU). The treatment reduced the native microalgal symbiont abundance to below 2% of their starting densities. The bleached corals were then inoculated with a cultured Cladocopium C1[acro] strain. Genotyping of the Symbiodiniaceae communities before bleaching and after reinoculation showed that fragments of all six coral species acquired the Cladocopium C1[acro] strain used for inoculation. Our results provide strong evidence for the uptake of Symbiodiniaceae from the environment by adult corals. We also demonstrate the feasibility of chemical bleaching followed by reinoculation to manipulate the Symbiodiniaceae communities of adult corals, providing an innovative approach to establish new symbioses between adult corals and heat-evolved microalgal symbionts, which could prove highly relevant to coral reef restoration efforts.}, }
@article {pmid35129273, year = {2022}, author = {Chang, CY and Sun, XW and Tian, PP and Miao, NH and Zhang, YL and Liu, XD}, title = {Plant secondary metabolite and temperature determine the prevalence of Arsenophonus endosymbionts in aphid populations.}, journal = {Environmental microbiology}, volume = {24}, number = {8}, pages = {3764-3776}, doi = {10.1111/1462-2920.15929}, pmid = {35129273}, issn = {1462-2920}, mesh = {Amino Acids ; Animals ; *Aphids ; *Gammaproteobacteria ; *Gossypol ; Plants ; Prevalence ; Symbiosis ; Temperature ; }, abstract = {Transmission rate and role in hosts contribute to the prevalence of an endosymbiont. However, factors affecting transmission and role of facultative endosymbionts are still not well understood. Here, we illustrated that host plants and environmental temperatures affected the transmission, relative abundance and role of Arsenophonus in the cotton aphid Aphis gossypii. The transmission rate of this endosymbiont from mother aphids to offspring was relatively lower. High temperatures impeded the transmission, and infection rates declined as aphids were exposed to 30°C. Contents of amino acids and secondary metabolites were remarkably different among host plants. Aphids feeding on zucchini leaves containing a higher titre of amino acids and lower secondary metabolites harboured a relatively lower abundance of Arsenophonus. Concentrations of an amino acid and a plant secondary metabolite, cucurbitacin B, in aphid diet were not associated with Arsenophonus abundance. However, gossypol, another plant secondary metabolite, was strongly related with the abundance. Arsenophonus imparted a fitness benefit to aphids, and the benefit was dependent on host plants and gossypol concentration. In sum, plant secondary metabolite and environmental temperature affect transmission, relative abundance and role of Arsenophonus, which determine the endosymbiont prevalence in aphid populations.}, }
@article {pmid35127053, year = {2022}, author = {Travers Cook, TJ and Skirgaila, C and Martin, OY and Buser, CC}, title = {Infection by dsRNA viruses is associated with enhanced sporulation efficiency in Saccharomyces cerevisiae.}, journal = {Ecology and evolution}, volume = {12}, number = {1}, pages = {e8558}, pmid = {35127053}, issn = {2045-7758}, abstract = {Upon starvation diploid cells of the facultative sexual yeast Saccharomyces cerevisiae undergo sporulation, forming four metabolically quiescent and robust haploid spores encased in a degradable ascus. All endosymbionts, whether they provide net benefits or costs, utilize host resources; in yeast, this should induce an earlier onset of sporulation. Here, we tested whether the presence of endosymbiotic dsRNA viruses (M satellite and L-A helper) correspond with higher sporulation rate of their host, S. cerevisiae. We find that S. cerevisiae hosting both the M and L-A viruses (so-called "killer yeasts") have significantly higher sporulation efficiency than those without. We also found that the removal of the M virus did not reduce sporulation frequency, possibly because the L-A virus still utilizes host resources with and without the M virus. Our findings indicate that either virulent resource use by endosymbionts induces sporulation, or that viruses are spread more frequently to sporulating strains. Further exploration is required to distinguish cause from effect.}, }
@article {pmid35127049, year = {2022}, author = {Kaech, H and Jud, S and Vorburger, C}, title = {Similar cost of Hamiltonella defensa in experimental and natural aphid-endosymbiont associations.}, journal = {Ecology and evolution}, volume = {12}, number = {1}, pages = {e8551}, pmid = {35127049}, issn = {2045-7758}, abstract = {Endosymbiont-conferred resistance to parasitoids is common in aphids, but comes at a cost to the host in the absence of parasitoids. In black bean aphids (Aphis fabae), costs in terms of reduced lifespan and lifetime reproduction were demonstrated by introducing 11 isolates of the protective symbiont Hamiltonella defensa into previously uninfected aphid clones. Transfection of H. defensa isolates into a common genetic background allows to compare the costs of different endosymbiont isolates unconfounded by host genetic variation, but has been suggested to overestimate the realized costs of the endosymbiont in natural populations, because transfection creates new and potentially maladapted host-symbiont combinations that would be eliminated by natural selection in the field. In this experiment, we show that removing H. defensa isolates from their natural host clones with antibiotics results in a fitness gain that is comparable to the fitness loss from their introduction into two new clones. This suggests that estimating cost by transfecting endosymbiont isolates into a shared host genotype does not lead to gross overestimates of their realized costs, at least not in the two recipient genotypes used here. By comparing our data with data reported in previous publications using the same lines, we show that symbiont-induced costs may fluctuate over time. Thus, costs estimated after extended culture in the laboratory may not always be representative of the costs at the time of collection in the field. Finally, we report the accidental observation that two isolates from a distinct haplotype of H. defensa could not be removed by cefotaxime treatment, while all isolates from two other haplotypes were readily eliminated, which is suggestive of variation in susceptibility to this antibiotic in H. defensa.}, }
@article {pmid35126998, year = {2022}, author = {Markalanda, SH and McFadden, CJ and Cassidy, ST and Wood, CW}, title = {The soil microbiome increases plant survival and modifies interactions with root endosymbionts in the field.}, journal = {Ecology and evolution}, volume = {12}, number = {1}, pages = {e8283}, pmid = {35126998}, issn = {2045-7758}, abstract = {Evidence is accumulating that the soil microbiome-the community of microorganisms living in soils-has a major effect on plant traits and fitness. However, most work to date has taken place under controlled laboratory conditions and has not experimentally disentangled the effect of the soil microbiome on plant performance from the effects of key endosymbiotic constituents. As a result, it is difficult to extrapolate from existing data to understand the role of the soil microbiome in natural plant populations. To address this gap, we performed a field experiment using the black medick Medicago lupulina to test how the soil microbiome influences plant performance and colonization by two root endosymbionts (the mutualistic nitrogen-fixing bacteria Ensifer spp. and the parasitic root-knot nematode Meloidogyne hapla) under natural conditions. We inoculated all plants with nitrogen-fixing bacteria and factorially manipulated the soil microbiome and nematode infection. We found that plants grown in microbe-depleted soil exhibit greater mortality, but that among the survivors, there was no effect of the soil microbiome on plant performance (shoot biomass, root biomass, or shoot-to-root ratio). The soil microbiome also impacted parasitic nematode infection and affected colonization by mutualistic nitrogen-fixing bacteria in a plant genotype-dependent manner, increasing colonization in some plant genotypes and decreasing it in others. Our results demonstrate the soil microbiome has complex effects on plant-endosymbiont interactions and may be critical for survival under natural conditions.}, }
@article {pmid35115648, year = {2022}, author = {Katlav, A and Nguyen, DT and Morrow, JL and Spooner-Hart, RN and Riegler, M}, title = {Endosymbionts moderate constrained sex allocation in a haplodiploid thrips species in a temperature-sensitive way.}, journal = {Heredity}, volume = {128}, number = {3}, pages = {169-177}, pmid = {35115648}, issn = {1365-2540}, mesh = {Animals ; Bacteroidetes ; Female ; Male ; Sex Ratio ; Symbiosis/genetics ; Temperature ; *Thysanoptera/genetics/microbiology ; *Wolbachia/genetics ; }, abstract = {Maternally inherited bacterial endosymbionts that affect host fitness are common in nature. Some endosymbionts colonise host populations by reproductive manipulations (such as cytoplasmic incompatibility; CI) that increase the reproductive fitness of infected over uninfected females. Theory predicts that CI-inducing endosymbionts in haplodiploid hosts may also influence sex allocation, including in compatible crosses, however, empirical evidence for this is scarce. We examined the role of two common CI-inducing endosymbionts, Cardinium and Wolbachia, in the sex allocation of Pezothrips kellyanus, a haplodiploid thrips species with a split sex ratio. In this species, irrespective of infection status, some mated females are constrained to produce extremely male-biased broods, whereas other females produce extremely female-biased broods. We analysed brood sex ratio of females mated with males of the same infection status at two temperatures. We found that at 20 °C the frequency of constrained sex allocation in coinfected pairs was reduced by 27% when compared to uninfected pairs. However, at 25 °C the constrained sex allocation frequency increased and became similar between coinfected and uninfected pairs, resulting in more male-biased population sex ratios at the higher temperature. This temperature-dependent pattern occurred without changes in endosymbiont densities and compatibility. Our findings indicate that endosymbionts affect sex ratios of haplodiploid hosts beyond the commonly recognised reproductive manipulations by causing female-biased sex allocation in a temperature-dependent fashion. This may contribute to a higher transmission efficiency of CI-inducing endosymbionts and is consistent with previous models that predict that CI by itself is less efficient in driving endosymbiont invasions in haplodiploid hosts.}, }
@article {pmid35113477, year = {2022}, author = {Bourland, W and Pomahač, O and Čepička, I}, title = {Morphology and phylogeny of two anaerobic freshwater ciliates: Brachonella comma sp. nov. and the widely distributed but little-known caenomorphid, Ludio parvulus Penard, 1922.}, journal = {The Journal of eukaryotic microbiology}, volume = {69}, number = {3}, pages = {e12892}, doi = {10.1111/jeu.12892}, pmid = {35113477}, issn = {1550-7408}, mesh = {Anaerobiosis ; *Ciliophora/genetics ; Fresh Water ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; }, abstract = {Hypoxic, sulfidic freshwater sediments typically support a diffuse consortium of distinctive ciliated protists, including caenomorphids, metopids, and odontostomatids among others. A recent resurgence of interest in these important members of sapropelic food webs has resulted in the description of many new species and an effort, still in its infancy, to characterize them from a morphologic, molecular, and metabolic standpoint and to determine their phylogenetic relationships. Their seemingly invariable association with prokaryotic endosymbionts and, less commonly, ectosymbionts has become a focus for many researchers. In this report, based on morphologic and molecular data, we describe a Brachonella species (Ciliophora, Metopida) new to science and analyze its phylogeny. We also provide a morphologic and molecular characterization of the smallest representative of the Caenomorphidae Poche, 1913, Ludio parvulus Penard, 1922. The phylogenetic analysis confirms the inclusion of this species in the Caenomorphidae.}, }
@article {pmid35112871, year = {2022}, author = {Deutsch, JM and Mandelare-Ruiz, P and Yang, Y and Foster, G and Routhu, A and Houk, J and De La Flor, YT and Ushijima, B and Meyer, JL and Paul, VJ and Garg, N}, title = {Metabolomics Approaches to Dereplicate Natural Products from Coral-Derived Bioactive Bacteria.}, journal = {Journal of natural products}, volume = {85}, number = {3}, pages = {462-478}, doi = {10.1021/acs.jnatprod.1c01110}, pmid = {35112871}, issn = {1520-6025}, mesh = {Animals ; *Anthozoa/microbiology ; Anti-Bacterial Agents/metabolism/pharmacology ; Bacteria/genetics ; *Biological Products/metabolism/pharmacology ; Metabolomics ; Symbiosis ; }, abstract = {Stony corals (Scleractinia) are invertebrates that form symbiotic relationships with eukaryotic algal endosymbionts and the prokaryotic microbiome. The microbiome has the potential to produce bioactive natural products providing defense and resilience to the coral host against pathogenic microorganisms, but this potential has not been extensively explored. Bacterial pathogens can pose a significant threat to corals, with some species implicated in primary and opportunistic infections of various corals. In response, probiotics have been proposed as a potential strategy to protect corals in the face of increased incidence of disease outbreaks. In this study, we screened bacterial isolates from healthy and diseased corals for antibacterial activity. The bioactive extracts were analyzed using untargeted metabolomics. Herein, an UpSet plot and hierarchical clustering analyses were performed to identify isolates with the largest number of unique metabolites. These isolates also displayed different antibacterial activities. Through application of in silico and experimental approaches coupled with genome analysis, we dereplicated natural products from these coral-derived bacteria from Florida's coral reef environments. The metabolomics approach highlighted in this study serves as a useful resource to select probiotic candidates and enables insights into natural product-mediated chemical ecology in holobiont symbiosis.}, }
@article {pmid35108076, year = {2022}, author = {Giannotti, D and Boscaro, V and Husnik, F and Vannini, C and Keeling, PJ}, title = {The "Other" Rickettsiales: an Overview of the Family "Candidatus Midichloriaceae".}, journal = {Applied and environmental microbiology}, volume = {88}, number = {6}, pages = {e0243221}, pmid = {35108076}, issn = {1098-5336}, mesh = {*Alphaproteobacteria/genetics ; Animals ; Bacteria ; Phylogeny ; *Rickettsiales ; Symbiosis ; }, abstract = {The family "Candidatus Midichloriaceae" constitutes the most diverse but least studied lineage within the important order of intracellular bacteria Rickettsiales. "Candidatus Midichloriaceae" endosymbionts are found in many hosts, including terrestrial arthropods, aquatic invertebrates, and protists. Representatives of the family are not documented to be pathogenic, but some are associated with diseased fish or corals. Different genera display a range of unusual features, such as full sets of flagellar genes without visible flagella or the ability to invade host mitochondria. Since studies on "Ca. Midichloriaceae" tend to focus on the host, the family is rarely addressed as a unit, and we therefore lack a coherent picture of its diversity. Here, we provide four new midichloriaceae genomes, and we survey molecular and ecological data from the entire family. Features like genome size, ecological context, and host transitions vary considerably even among closely related midichloriaceae, suggesting a high frequency of such shifts, incomplete sampling, or both. Important functional traits involved in energy metabolism, flagella, and secretion systems were independently reduced multiple times with no obvious correspondence to host or habitat, corroborating the idea that many features of these "professional symbionts" are largely independent of host identity. Finally, despite "Ca. Midichloriaceae" being predominantly studied in ticks, our analyses show that the clade is mainly aquatic, with a few terrestrial offshoots. This highlights the importance of considering aquatic hosts, and protists in particular, when reconstructing the evolution of these endosymbionts and by extension all Rickettsiales. IMPORTANCE Among endosymbiotic bacterial lineages, few are as intensely studied as Rickettsiales, which include the causative agents of spotted fever, typhus, and anaplasmosis. However, an important subgroup called "Candidatus Midichloriaceae" receives little attention despite accounting for a third of the diversity of Rickettsiales and harboring a wide range of bacteria with unique features, like the ability to infect mitochondria. Midichloriaceae are found in many hosts, from ticks to corals to unicellular protozoa, and studies on them tend to focus on the host groups. Here, for the first time since the establishment of this clade, we address the genomics, evolution, and ecology of "Ca. Midichloriaceae" as a whole, highlighting trends and patterns, the remaining gaps in our knowledge, and its importance for the understanding of symbiotic processes in intracellular bacteria.}, }
@article {pmid35107338, year = {2022}, author = {Stephens, ME and Benjamino, J and Graf, J and Gage, DJ}, title = {Simultaneous Single-Cell Genome and Transcriptome Sequencing of Termite Hindgut Protists Reveals Metabolic and Evolutionary Traits of Their Endosymbionts.}, journal = {mSphere}, volume = {7}, number = {1}, pages = {e0002122}, pmid = {35107338}, issn = {2379-5042}, mesh = {Animals ; Bacteria ; Carbon/metabolism ; Eukaryota/genetics ; *Isoptera/microbiology ; Phylogeny ; Symbiosis/genetics ; Transcriptome ; }, abstract = {Some of the protist species which colonize the hindguts of wood-feeding Reticulitermes termites are associated with endosymbiotic bacteria belonging to the genus Endomicrobium. In this study, we focused on the endosymbionts of three protist species from Reticulitermes flavipes, as follows: Pyrsonympha vertens, Trichonympha agilis, and Dinenympha species II. Since these protist hosts represented members of different taxa which colonize separate niches within the hindguts of their termite hosts, we investigated if these differences translated to differential gene content and expression in their endosymbionts. Following assembly and comparative genome and transcriptome analyses, we discovered that these endosymbionts differed with respect to some possible niche-specific traits, such as carbon metabolism. Our analyses suggest that species-specific genes related to carbon metabolism were acquired by horizontal gene transfer (HGT) and may have come from taxa which are common in the termite hind gut. In addition, our analyses suggested that these endosymbionts contain and express genes related to natural transformation (competence) and recombination. Taken together, the presence of genes acquired by HGT and a putative competence pathway suggest that these endosymbionts are not cut off from gene flow and that competence may be a mechanism by which members of Endomicrobium can acquire new traits. IMPORTANCE The composition and structure of wood, which contains cellulose, hemicellulose, and lignin, prevent most organisms from using this common food source. Termites are a rare exception among animals, and they rely on a complex microbiota housed in their hindguts to use wood as a source of food. The lower termite, Reticulitermes flavipes, houses a variety of protists and prokaryotes that are the key players in the disassembly of lignocellulose. Here, we describe the genomes and the gene expression profiles of five Endomicrobium endosymbionts living inside three different protist species from R. flavipes. Data from these genomes suggest that these Endomicrobium species have different mechanisms for using carbon. In addition, they harbor genes that may be used to import DNA from their environment. This process of DNA uptake may contribute to the high levels of horizontal gene transfer noted previously in Endomicrobium species.}, }
@article {pmid35092614, year = {2022}, author = {Rodrigues, LR and Zélé, F and Santos, I and Magalhães, S}, title = {No evidence for the evolution of mating behavior in spider mites due to Wolbachia-induced cytoplasmic incompatibility.}, journal = {Evolution; international journal of organic evolution}, volume = {76}, number = {3}, pages = {623-635}, doi = {10.1111/evo.14429}, pmid = {35092614}, issn = {1558-5646}, mesh = {Animals ; *Arthropods ; Cytoplasm ; Female ; Male ; Reproduction ; *Tetranychidae/genetics ; *Wolbachia/genetics ; }, abstract = {Arthropods are often infected with Wolbachia inducing cytoplasmic incompatibility (CI), whereby crosses between uninfected females and infected males yield unviable fertilized offspring. Although uninfected females benefit from avoiding mating with Wolbachia-infected males, this behavior is not always present in host populations and its evolution may hinge upon various factors. Here, we used spider mites to test whether CI could select for mate preference in uninfected females in absence of kin recognition. We found that uninfected females from several field-derived populations showed no preference for infected or uninfected males, nor evolved a preference after being exposed to CI for 12-15 generations by maintaining uninfected females with both infected and uninfected males (i.e., stable "infection polymorphism"). This suggests that Wolbachia-mediated mate choice evolution may require very specific conditions in spider mites. However, after experimental evolution, the copulation duration of Wolbachia-infected control males was significantly higher than that of uninfected control males, but not than that of uninfected males from the "infection polymorphism" regime. This result illustrates how gene flow may oppose Wolbachia-driven divergence between infected and uninfected hosts in natural populations.}, }
@article {pmid35087493, year = {2021}, author = {Flemming, FE and Grosser, K and Schrallhammer, M}, title = {Natural Shifts in Endosymbionts' Occurrence and Relative Frequency in Their Ciliate Host Population.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {791615}, pmid = {35087493}, issn = {1664-302X}, abstract = {The role of bacterial endosymbionts harbored by heterotrophic Paramecium species is complex. Obligate intracellular bacteria supposedly always inflict costs as the host is the only possible provider of resources. However, several experimental studies have shown that paramecia carrying bacterial endosymbionts can benefit from their infection. Here, we address the question which endosymbionts occur in natural paramecia populations isolated from a small lake over a period of 5 years and which factors might explain observed shifts and persistence in the symbionts occurrence. One hundred and nineteen monoclonal strains were investigated and approximately two-third harbored intracellular bacteria. The majority of infected paramecia carried the obligate endosymbiotic "Candidatus Megaira polyxenophila", followed by Caedimonas varicaedens, and Holospora undulata. The latter was only detected in a single strain. While "Ca. M. polyxenophila" was observed in seven out of 13 samplings, C. varicaedens presence was limited to a single sampling occasion. After the appearance of C. varicaedens, "Ca. M. polyxenophila" prevalence dramatically dropped with some delay but recovered to original levels at the end of our study. Potential mechanisms explaining these observations include differences in infectivity, host range, and impact on host fitness as well as host competitive capacities. Growth experiments revealed fitness advantages for infected paramecia harboring "Ca. M. polyxenophila" as well as C. varicaedens. Furthermore, we showed that cells carrying C. varicaedens gain a competitive advantage from the symbiosis-derived killer trait. Other characteristics like infectivity and overlapping host range were taken into consideration, but the observed temporal persistence of "Ca. M. polyxenophila" is most likely explained by the positive effect this symbiont provides to its host.}, }
@article {pmid35076268, year = {2022}, author = {Perez-Lamarque, B and Krehenwinkel, H and Gillespie, RG and Morlon, H}, title = {Limited Evidence for Microbial Transmission in the Phylosymbiosis between Hawaiian Spiders and Their Microbiota.}, journal = {mSystems}, volume = {7}, number = {1}, pages = {e0110421}, pmid = {35076268}, issn = {2379-5077}, abstract = {The degree of similarity between the microbiotas of host species often mirrors the phylogenetic proximity of the hosts. This pattern, referred to as phylosymbiosis, is widespread in animals and plants. While phylosymbiosis was initially interpreted as the signal of symbiotic transmission and coevolution between microbes and their hosts, it is now recognized that similar patterns can emerge even if the microbes are environmentally acquired. Distinguishing between these two scenarios, however, remains challenging. We recently developed HOME (host-microbiota evolution), a cophylogenetic model designed to detect vertically transmitted microbes and host switches from amplicon sequencing data. Here, we applied HOME to the microbiotas of Hawaiian spiders of the genus Ariamnes, which experienced a recent radiation on the archipelago. We demonstrate that although Hawaiian Ariamnes spiders display a significant phylosymbiosis, there is little evidence of microbial vertical transmission. Next, we performed simulations to validate the absence of transmitted microbes in Ariamnes spiders. We show that this is not due to a lack of detection power because of the low number of segregating sites or an effect of phylogenetically driven or geographically driven host switches. Ariamnes spiders and their associated microbes therefore provide an example of a pattern of phylosymbiosis likely emerging from processes other than vertical transmission. IMPORTANCE How host-associated microbiotas assemble and evolve is one of the outstanding questions of microbial ecology. Studies aiming at answering this question have repeatedly found a pattern of "phylosymbiosis," that is, a phylogenetic signal in the composition of host-associated microbiotas. While phylosymbiosis was often interpreted as evidence for vertical transmission and host-microbiota coevolution, simulations have now shown that it can emerge from other processes, including host filtering of environmentally acquired microbes. However, distinguishing the processes driving phylosymbiosis in nature remains challenging. We recently developed a cophylogenetic method that can detect vertical transmission. Here, we applied this method to the microbiotas of recently diverged spiders from the Hawaiian archipelago, which display a clear phylosymbiosis pattern. We found that none of the bacterial operational taxonomic units is vertically transmitted. We show with simulations that this result is not due to methodological artifacts. Thus, we provide a striking empirical example of phylosymbiosis emerging from processes other than vertical transmission.}, }
@article {pmid35071375, year = {2021}, author = {Cull, B and Burkhardt, NY and Wang, XR and Thorpe, CJ and Oliver, JD and Kurtti, TJ and Munderloh, UG}, title = {The Ixodes scapularis Symbiont Rickettsia buchneri Inhibits Growth of Pathogenic Rickettsiaceae in Tick Cells: Implications for Vector Competence.}, journal = {Frontiers in veterinary science}, volume = {8}, number = {}, pages = {748427}, pmid = {35071375}, issn = {2297-1769}, abstract = {Ixodes scapularis is the primary vector of tick-borne pathogens in North America but notably does not transmit pathogenic Rickettsia species. This tick harbors the transovarially transmitted endosymbiont Rickettsia buchneri, which is widespread in I. scapularis populations, suggesting that it confers a selective advantage for tick survival such as providing essential nutrients. The R. buchneri genome includes genes with similarity to those involved in antibiotic synthesis. There are two gene clusters not found in other Rickettsiaceae, raising the possibility that these may be involved in excluding pathogenic bacteria from the tick. This study explored whether the R. buchneri antibiotic genes might exert antibiotic effects on pathogens associated with I. scapularis. Markedly reduced infectivity and replication of the tick-borne pathogens Anaplasma phagocytophilum, R. monacensis, and R. parkeri were observed in IRE11 tick cells hosting R. buchneri. Using a fluorescent plate reader assay to follow infection dynamics revealed that the presence of R. buchneri in tick cells, even at low infection rates, inhibited the growth of R. parkeri by 86-100% relative to R. buchneri-free cells. In contrast, presence of the low-pathogenic species R. amblyommatis or the endosymbiont R. peacockii only partially reduced the infection and replication of R. parkeri. Addition of host-cell free R. buchneri, cell lysate of R. buchneri-infected IRE11, or supernatant from R. buchneri-infected IRE11 cultures had no effect on R. parkeri infection and replication in IRE11, nor did these treatments show any antibiotic effect against non-obligate intracellular bacteria E. coli and S. aureus. However, lysate from R. buchneri-infected IRE11 challenged with R. parkeri showed some inhibitory effect on R. parkeri infection of treated IRE11, suggesting that challenge by pathogenic rickettsiae may induce the antibiotic effect of R. buchneri. This research suggests a potential role of the endosymbiont in preventing other rickettsiae from colonizing I. scapularis and/or being transmitted transovarially. The confirmation that the observed inhibition is linked to R. buchneri's antibiotic clusters requires further investigation but could have important implications for our understanding of rickettsial competition and vector competence of I. scapularis for rickettsiae.}, }
@article {pmid35066589, year = {2022}, author = {Hidayanti, AK and Gazali, A and Tagami, Y}, title = {Effect of Quorum Sensing Inducers and Inhibitors on Cytoplasmic Incompatibility Induced by Wolbachia (Rickettsiales: Anaplasmataceae) in American Serpentine Leafminer (Diptera: Agromyzidae): Potential Tool for the Incompatible Insect Technique.}, journal = {Journal of insect science (Online)}, volume = {22}, number = {1}, pages = {}, pmid = {35066589}, issn = {1536-2442}, mesh = {Animals ; *Diptera/microbiology ; Ovum ; *Pest Control, Biological ; *Quorum Sensing ; *Wolbachia ; }, abstract = {Agricultural crops around the world are attacked by approximately 3,000-10,000 species of pest insect. There is increasing interest in resolving this problem using environmentally friendly approaches. Wolbachia (Hertig), an insect endosymbiont, can modulate host reproduction and offspring sex through cytoplasmic incompatibility (CI). The incompatible insect technique (IIT) based on CI-Wolbachia is a promising biological control method. Previous studies have reported an association between CI and Wolbachia density, which may involve a quorum sensing (QS) mechanism. In this study, we investigated the effect of manipulating QS in Wolbachia using several chemicals including 3O-C12-HSL; C2HSL; spermidine (QS inducers), 4-phenylbutanoyl; and 4-NPO (QS inhibitors) on American serpentine leafminer (Liriomyza trifolii [Burgess]), an agricultural pest. The results showed that inducing QS with 3O-C12-HSL decreased the proportion of hatched eggs and increased Wolbachia density, whereas QS inhibition with 4-phenylbutanoyl had the opposite effects. Thus, manipulating QS in Wolbachia can alter cell density and the proportion of hatched eggs in the host L. trifolii, thereby reducing the number of insect progeny. These findings provide evidence supporting the potential efficacy of the IIT based on CI-Wolbachia for the environmentally friendly control of insect pest populations.}, }
@article {pmid35057842, year = {2022}, author = {Perveen, N and Muzaffar, SB and Vijayan, R and Al-Deeb, MA}, title = {Microbial composition in Hyalomma anatolicum collected from livestock in the United Arab Emirates using next-generation sequencing.}, journal = {Parasites &amp; vectors}, volume = {15}, number = {1}, pages = {30}, pmid = {35057842}, issn = {1756-3305}, mesh = {Animals ; Bacteria/classification/*genetics/*isolation &amp; purification ; Cross-Sectional Studies ; Genetic Variation ; High-Throughput Nucleotide Sequencing/*methods ; Ixodidae/*microbiology ; Livestock/*parasitology ; Male ; Microbiota/*genetics ; Tick Infestations/epidemiology/*veterinary ; Tick-Borne Diseases/epidemiology/microbiology/transmission ; United Arab Emirates/epidemiology ; }, abstract = {BACKGROUND: Hyalomma anatolicum is a widely distributed tick species that acts as a vector transmitting tick-borne pathogens (TBPs) in livestock. Such pathogens affect the health of livestock and consequently reduce their productivity. Knowledge about the microbial communities (pathogens and endosymbionts) of ticks in the United Arab Emirates (UAE) is scarce. Therefore, the aim of the present study was to quantify microbial diversity in H. anatolicum using next-generation sequencing (NGS) technology.<br><br>METHODS: Hyalomma anatolicum ticks were collected from livestock in the emirates of Abu Dhabi, Dubai and Sharjah in the UAE during 2019. DNA was extracted from 175 male ticks sampled from livestock (n&#x2009;=&#x2009;78) and subjected to NGS. The 16S rRNA gene was analyzed using the Illumina MiSeq platform to determine the bacterial communities. Principal coordinates analysis (PCA) was performed to identify patterns of diversity in the bacterial communities.<br><br>RESULTS: Twenty-six bacterial families with high relative abundance were identified, of which the most common were Staphylococcaceae, Francisellaceae, Corynebacteriaceae, Enterobacteriaceae, Moraxellaceae, Bacillaceae, Halomonadaceae, Xanthomonadaceae, Pseudomonadaceae, Enterococcaceae, Actinomycetaceae and Streptococcaceae. The diversity of the microbial communities in terms of richness and evenness was different at the three study locations, with the PCA showing clear clusters separating the microbial communities in ticks collected at Abu Dhabi, Dubai, and Sharjah. The presence of bacterial families harboring pathogenic genera showed that H. anatolicum could pose a potential threat to livestock and food security in the UAE.<br><br>CONCLUSIONS: The study is the first to document important data on the microbial communities associated with H. anatolicum in the UAE. This knowledge will facilitate a better understanding of the distribution pattern of microbes in livestock ticks in the UAE and, ultimately, will aid in deciphering the relationships between microbes and in the exploration of potential factors towards developing effective management strategies.}, }
@article {pmid35056571, year = {2022}, author = {Oborník, M}, title = {Organellar Evolution: A Path from Benefit to Dependence.}, journal = {Microorganisms}, volume = {10}, number = {1}, pages = {}, pmid = {35056571}, issn = {2076-2607}, abstract = {Eukaryotic organelles supposedly evolved from their bacterial ancestors because of their benefits to host cells. However, organelles are quite often retained, even when the beneficial metabolic pathway is lost, due to something other than the original beneficial function. The organellar function essential for cell survival is, in the end, the result of organellar evolution, particularly losses of redundant metabolic pathways present in both the host and endosymbiont, followed by a gradual distribution of metabolic functions between the organelle and host. Such biological division of metabolic labor leads to mutual dependence of the endosymbiont and host. Changing environmental conditions, such as the gradual shift of an organism from aerobic to anaerobic conditions or light to dark, can make the original benefit useless. Therefore, it can be challenging to deduce the original beneficial function, if there is any, underlying organellar acquisition. However, it is also possible that the organelle is retained because it simply resists being eliminated or digested untill it becomes indispensable.}, }
@article {pmid35055928, year = {2022}, author = {Lai, C and Hou, Y and Hao, P and Pang, K and Yu, X}, title = {Detection of Yeast-like Symbionts in Brown Planthopper Reared on Different Resistant Rice Varieties Combining DGGE and Absolute Quantitative Real-Time PCR.}, journal = {Insects}, volume = {13}, number = {1}, pages = {}, pmid = {35055928}, issn = {2075-4450}, abstract = {The brown planthopper (BPH), Nilaparvata lugens, is a serious pest of rice throughout Asia. Yeast-like symbionts (YLS) are endosymbionts closely linked with the development of BPH and the adapted mechanism of BPH virulence to resistant plants. In this study, we used semi-quantitative DGGE and absolute quantitative real-time PCR (qPCR) to quantify the number of the three YLS strains (Ascomycetes symbionts, Pichia-like symbionts, and Candida-like symbionts) that typically infect BPH in the nymphal stages and in newly emerged female adults. The quantities of each of the three YLS assessed increased in tandem with the developing nymphal instar stages, peaking at the fourth instar stage, and then declined significantly at the fifth instar stage. However, the amount of YLS present recovered sharply within the emerging adult females. Additionally, we estimated the quantities of YLS for up to eight generations after their inoculation onto resistant cultivars (Mudgo, ASD7, and RH) to reassociate the dynamics of YLS with the fitness of BPH. The minimum number of each YLS was detected in the second generation and gradually increased from the third generation with regard to resistant rice varieties. In addition, the Ascomycetes symbionts of YLS were found to be the most abundant of the three YLS strains tested for all of the development stages of BPH.}, }
@article {pmid35055852, year = {2021}, author = {Du, S and Ye, F and Wang, Q and Liang, Y and Wan, W and Guo, J and Liu, W}, title = {Multiple Data Demonstrate That Bacteria Regulating Reproduction Could Be Not the Cause for the Thelytoky of Diglyphus&amp;nbsp;wani (Hymenoptera: Eulophidae).}, journal = {Insects}, volume = {13}, number = {1}, pages = {}, pmid = {35055852}, issn = {2075-4450}, abstract = {In Hymenoptera parasitoids, the reproductive mode is arrhenotoky, while a few species reproduce by thelytoky. The thelytoky of Hymenoptera parasitoids is generally genetically determined by the parasitoids themselves or induced by bacteria, including Wolbachia, Cardinium, and Rickettsia. Diglyphus&amp;nbsp;wani (Hymenoptera: Eulophidae), a recently reported thelytokous species is a main parasitoid attacking agromyzid leafminers. To assess whether endosymbionts induce thelytoky in D.&amp;nbsp;wani, we performed universal PCR detection and sequenced the V3-V4 region of 16S ribosomal RNA gene. In addition, bacteria were removed through high-temperature and antibiotic treatments, and the localized bacteria were detected using FISH. Based on general PCR detection, Wolbachia, Cardinium, Rickettsia, Arsenophonus, Spiroplasma, and Microsporidia were absent in laboratory and field individuals of thelytokous D.&amp;nbsp;wani. Furthermore, 16S rRNA gene sequencing revealed that the dominant endosymbionts in thelytokous D.&amp;nbsp;wani were not reproductive manipulators. High-temperature and antibiotic treatment for five consecutive generations cannot reverse the thelytokous pattern of D.&amp;nbsp;wani, and no male offspring were produced. Moreover, no bacterial spots were found in the ovaries of D.&amp;nbsp;wani. Thus, it is considered that the thelytoky of D. wani does not result in the presence of endosymbionts. This species is thus the second reported eulophid parasitoid whose thelytoky appears not to be associated with endosymbionts.}, }
@article {pmid35053126, year = {2022}, author = {Castelo, MK and Crespo, JE}, title = {Microorganismal Cues Involved in Host-Location in Asilidae Parasitoids.}, journal = {Biology}, volume = {11}, number = {1}, pages = {}, pmid = {35053126}, issn = {2079-7737}, abstract = {Parasitoids are organisms that kill their host before completing their development. Typical parasitoids belong to Hymenoptera, whose females search for the hosts. But some atypical Diptera parasitoids also have searching larvae that must orientate toward, encounter, and accept hosts, through cues with different levels of detectability. In this work, the chemical cues involved in the detection of the host by parasitoid larvae of the genus Mallophora are shown with a behavioral approach. Through olfactometry assays, we show that two species of Mallophora orient to different host species and that chemical cues are produced by microorganisms. We also show that treating potential hosts with antibiotics reduces attractiveness on M. ruficauda but not to M. bigoti suggesting that endosymbiotic bacteria responsible for the host cues production should be located in different parts of the host. In fact, we were able to show that M. bigoti is attracted to frass from the most common host. Additionally, we evaluated host orientation under a context of interspecific competence and found that both parasitoid species orient to Cyclocephaala signaticollis showing that host competition could occur in the field. Our work shows how microorganisms mediate orientation to hosts but differences in their activity or location in the host result in differences in the attractiveness of different cues. We show for the first time that M. bigoti behaves similar to M. ruficauda extending and reinforcing that all Mallophora species have adopted a parasitoid lifestyle.}, }
@article {pmid35051873, year = {2022}, author = {Gomaa, F and Utter, DR and Loo, W and Lahr, DJG and Cavanaugh, CM}, title = {Exploring the protist microbiome: The diversity of bacterial communities associated with Arcella spp. (Tubulina: Amoebozoa).}, journal = {European journal of protistology}, volume = {82}, number = {}, pages = {125861}, doi = {10.1016/j.ejop.2021.125861}, pmid = {35051873}, issn = {1618-0429}, mesh = {*Amoebozoa ; Bacteria/genetics ; Humans ; *Microbiota ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Tubulina ; }, abstract = {Research on protist-bacteria interactions is increasingly relevant as these associations are now known to play important roles in ecosystem and human health. Free-living amoebae are abundant in all environments and are frequent hosts for bacterial endosymbionts including pathogenic bacteria. However, to date, only a small fraction of these symbionts have been identified, while the structure and composition of the total symbiotic bacterial communities still remains largely unknown. Here, we use the testate amoeba Arcella spp. as model organisms to investigate the specificity and diversity of Arcella-associated microbial communities. High-throughputamplicon sequencing from the V4 region of the 16S rRNA gene revealed high diversity in the bacterial communities associated with the wild Arcella spp. To investigate the specificity of the associated bacterial community with greater precision, we investigated the bacterial communities of two lab-cultured Arcella species, A. hemispherica and A. intermedia, grown in two different media types. Our results suggest that Arcella-bacteria associations are species-specific, and that the associated bacterial community of lab-cultured Arcella spp. remains distinct from that of the surrounding media. Further, each host Arcella species could be distinguished based on its bacterial composition. Our findings provide insight into the understanding of eukaryotic-bacterial symbiosis.}, }
@article {pmid35050159, year = {2022}, author = {Fernando, K and Reddy, P and Guthridge, KM and Spangenberg, GC and Rochfort, SJ}, title = {A Metabolomic Study of Epichloë Endophytes for Screening Antifungal Metabolites.}, journal = {Metabolites}, volume = {12}, number = {1}, pages = {}, pmid = {35050159}, issn = {2218-1989}, abstract = {Epichloë endophytes, fungal endosymbionts of Pooidae grasses, are commonly utilized in forage and turf industries because they produce beneficial metabolites that enhance resistance against environmental stressors such as insect feeding and disease caused by phytopathogen infection. In pastoral agriculture, phytopathogenic diseases impact both pasture quality and animal production. Recently, bioactive endophyte strains have been reported to secrete compounds that significantly inhibit the growth of phytopathogenic fungi in vitro. A screen of previously described Epichloë-produced antifeedant and toxic alkaloids determined that the antifungal bioactivity observed is not due to the production of these known metabolites, and so there is a need for methods to identify new bioactive metabolites. The process described here is applicable more generally for the identification of antifungals in new endophytes. This study aims to characterize the fungicidal potential of novel, 'animal friendly' Epichloë endophyte strains NEA12 and NEA23 that exhibit strong antifungal activity using an in vitro assay. Bioassay-guided fractionation, followed by metabolite analysis, identified 61 metabolites that, either singly or in combination, are responsible for the observed bioactivity. Analysis of the perennial ryegrass-endophyte symbiota confirmed that NEA12 and NEA23 produce the prospective antifungal metabolites in symbiotic association and thus are candidates for compounds that promote disease resistance in planta. The "known unknown" suite of antifungal metabolites identified in this study are potential biomarkers for the selection of strains that enhance pasture and turf production through better disease control.}, }
@article {pmid35049085, year = {2022}, author = {Cao, Y and Dietrich, CH}, title = {Phylogenomics of flavobacterial insect nutritional endosymbionts with implications for Auchenorrhyncha phylogeny.}, journal = {Cladistics : the international journal of the Willi Hennig Society}, volume = {38}, number = {1}, pages = {38-58}, doi = {10.1111/cla.12474}, pmid = {35049085}, issn = {1096-0031}, mesh = {Animals ; *Flavobacteriaceae/genetics ; *Hemiptera/genetics ; Insecta/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis/genetics ; }, abstract = {"Candidatus Sulcia muelleri" (Sulcia) is a diverse lineage of intracellular nutritional endosymbiotic bacteria strictly associated with auchenorrhynchous hemipteran insects. Sulcia has undergone long-term codiversification with its insect hosts but the phylogeny of these endosymbionts, their relationships to other bacteria, and the extent of their occurrence within various groups of Auchenorrhyncha remain inadequately explored. Comprehensive phylogenetic analyses of Sulcia and related bacteria were performed to elucidate its position relative to other members of Phylum Bacteroidetes and the degree of congruence to the phylogeny of its auchenorrhynchous hosts. Maximum likelihood (ML) and maximum parsimony (MP) analyses of Flavobacteriales based on genomic data from 182 bacterial strains recover a monophyletic Sulcia within a larger clade of flavobacterial insect endosymbionts, closely related to Weeksellaceae. Molecular divergence time analysis of Sulcia dates the origin of Sulcia at approximately 339.95 million years ago (Myr) and the initial divergence within Sulcia at approximately 256.91 Myr but these are considered underestimates due to the tendency for endosymbionts to evolve at higher rates compared to their free-living relatives. Screening of 96 recently sequenced hemipteran transcriptomes revealed that 73 of these species, all Auchenorrhyncha, harbored Sulcia. Phylogenetic analysis of 131 orthologous genes plus 16S rRNA for 101 Sulcia strains, representing six fulgoroid families and all the families of Cicadomorpha except Tettigarctidae, recover largely congruent phylogenies between Sulcia and Auchenorrhyncha. The phylogeny of Sulcia strongly supports the superfamily relationships Fulgoroidea + (Cicadoidea + (Cercopoidea + Membracoidea)). Relationships within individual superfamilies are also largely concordant, with the few areas of apparent incongruence between Sulcia and insect genes attributable to low branch support in one or both datasets. These results suggest that analysis of Sulcia phylogeny may contribute to resolution of contentious aspects of Auchenorrhyncha phylogeny.}, }
@article {pmid35048168, year = {2022}, author = {Boscaro, V and Manassero, V and Keeling, PJ and Vannini, C}, title = {Single-cell Microbiomics Unveils Distribution and Patterns of Microbial Symbioses in the Natural Environment.}, journal = {Microbial ecology}, volume = {}, number = {}, pages = {}, pmid = {35048168}, issn = {1432-184X}, abstract = {Protist-bacteria associations are extremely common. Among them, those involving ciliates of the genus Euplotes are emerging as models for symbioses between prokaryotes and eukaryotes, and a great deal of information is available from cultured representatives of this system. Even so, as for most known microbial symbioses, data on natural populations is lacking, and their ecology remains largely unexplored; how well lab cultures represent actual diversity is untested. Here, we describe a survey on natural populations of Euplotes based on a single-cell microbiomic approach, focusing on taxa that include known endosymbionts of this ciliate. The results reveal an unexpected variability in symbiotic communities, with individual hosts of the same population harboring different sets of bacterial endosymbionts. Co-occurring Euplotes individuals of the same population can even have different essential symbionts, Polynucleobacter and "Candidatus Protistobacter," which might suggest that replacement events could be more frequent in nature than previously hypothesized. Accessory symbionts are even more variable: some showed a strong affinity for one host species, some for a sampling site, and two ("Candidatus Cyrtobacter" and "Candidatus Anadelfobacter") displayed an unusual pattern of competitive exclusion. These data represent the first insight into the prevalence and patterns of bacterial symbionts in natural populations of free-living protists.}, }
@article {pmid35046559, year = {2022}, author = {Grupstra, CGB and Howe-Kerr, LI and Veglia, AJ and Bryant, RL and Coy, SR and Blackwelder, PL and Correa, AMS}, title = {Thermal stress triggers productive viral infection of a key coral reef symbiont.}, journal = {The ISME journal}, volume = {16}, number = {5}, pages = {1430-1441}, pmid = {35046559}, issn = {1751-7370}, mesh = {Animals ; *Anthozoa ; Coral Reefs ; *Dinoflagellida/genetics ; Symbiosis ; *Virus Diseases ; }, abstract = {Climate change-driven ocean warming is increasing the frequency and severity of bleaching events, in which corals appear whitened after losing their dinoflagellate endosymbionts (family Symbiodiniaceae). Viral infections of Symbiodiniaceae may contribute to some bleaching signs, but little empirical evidence exists to support this hypothesis. We present the first temporal analysis of a lineage of Symbiodiniaceae-infecting positive-sense single-stranded RNA viruses ("dinoRNAVs") in coral colonies, which were exposed to a 5-day heat treatment (+2.1 °C). A total of 124 dinoRNAV major capsid protein gene "aminotypes" (unique amino acid sequences) were detected from five colonies of two closely related Pocillopora-Cladocopium (coral-symbiont) combinations in the experiment; most dinoRNAV aminotypes were shared between the two coral-symbiont combinations (64%) and among multiple colonies (82%). Throughout the experiment, seventeen dinoRNAV aminotypes were found only in heat-treated fragments, and 22 aminotypes were detected at higher relative abundances in heat-treated fragments. DinoRNAVs in fragments of some colonies exhibited higher alpha diversity and dispersion under heat stress. Together, these findings provide the first empirical evidence that exposure to high temperatures triggers some dinoRNAVs to switch from a persistent to a productive infection mode within heat-stressed corals. Over extended time frames, we hypothesize that cumulative dinoRNAV production in the Pocillopora-Cladocopium system could affect colony symbiotic status, for example, by decreasing Symbiodiniaceae densities within corals. This study sets the stage for reef-scale investigations of dinoRNAV dynamics during bleaching events.}, }
@article {pmid35045070, year = {2022}, author = {Yang, CJ and Hu, JM}, title = {Molecular phylogeny of Asian Ardisia (Myrsinoideae, Primulaceae) and their leaf-nodulated endosymbionts, Burkholderia s.l. (Burkholderiaceae).}, journal = {PloS one}, volume = {17}, number = {1}, pages = {e0261188}, pmid = {35045070}, issn = {1932-6203}, mesh = {*Burkholderia ; }, abstract = {The genus Ardisia (Myrsinoideae, Primulaceae) has 16 subgenera and over 700 accepted names, mainly distributed in tropical Asia and America. The circumscription of Ardisia is not well-defined and sometimes confounded with the separation of some small genera. A taxonomic revision focusing on Ardisia and allies is necessary. In the Ardisia subgenus Crispardisia, symbiotic association with leaf-nodule bacteria is a unique character within the genus. The endosymbionts are vertically transmitted, highly specific and highly dependent on the hosts, suggesting strict cospeciation may have occurred in the evolutionary history. In the present study, we aimed to establish a phylogenetic framework for further taxonomic revision. We also aimed to test the cospeciation hypothesis of the leaf-nodulate Ardisia and their endosymbiotic bacteria. Nuclear ITS and two chloroplast intergenic spaces were used to reconstruct the phylogeny of Asian Ardisia and relatives in Myrsinoideae, Primulaceae. The 16S-23S rRNA were used to reconstruct the bacterial symbionts' phylogeny. To understand the evolutionary association of the Ardisia and symbionts, topology tests and cophylogenetic analyses were conducted. The molecular phylogeny suggested Ardisia is not monophyletic, unless Sardiria, Hymenandra, Badula and Oncostemum are included. The results suggest the generic limit within Myrsinoideae (Primulaceae) needs to be further revised. The subgenera Crispardisia, Pimelandra, and Stylardisia were supported as monophyly, while the subgenus Bladhia was separated into two distant clades. We proposed to divide the subgenus Bladhia into subgenus Bladhia s.str. and subgenus Odontophylla. Both of the cophylogenetic analyses and topology tests rejected strict cospeciation hypothesis between Ardisia hosts and symbiotic Burkholderia. Cophylogenetic analyses showed general phylogenetic concordance of Ardisia and Burkholderia, and cospeciation events, host-switching events and loss events were all inferred.}, }
@article {pmid35042972, year = {2022}, author = {Prokopchuk, G and Korytář, T and Juricová, V and Majstorović, J and Horák, A and Šimek, K and Lukeš, J}, title = {Trophic flexibility of marine diplonemids - switching from osmotrophy to bacterivory.}, journal = {The ISME journal}, volume = {16}, number = {5}, pages = {1409-1419}, pmid = {35042972}, issn = {1751-7370}, mesh = {Bacteria/genetics ; *Ecosystem ; *Eukaryota ; Feeding Behavior ; Plankton ; }, abstract = {Diplonemids are one of the most abundant groups of heterotrophic planktonic microeukaryotes in the world ocean and, thus, are likely to play an essential role in marine ecosystems. So far, only few species have been introduced into a culture, allowing basic studies of diplonemid genetics, morphology, ultrastructure, metabolism, as well as endosymbionts. However, it remains unclear whether these heterotrophic flagellates are parasitic or free-living and what are their predominant dietary patterns and preferred food items. Here we show that cultured diplonemids, maintained in an organic-rich medium as osmotrophs, can gradually switch to bacterivory as a sole food resource, supporting positive growth of their population, even when fed with a low biovolume of bacteria. We further observed remarkable differences in species-specific feeding patterns, size-selective grazing preferences, and distinct feeding strategies. Diplonemids can discriminate between low-quality food items and inedible particles, such as latex beads, even after their ingestion, by discharging them in the form of large waste vacuoles. We also detected digestion-related endogenous autofluorescence emitted by lysosomes and the activity of a melanin-like material. We present the first evidence that these omnipresent protists possess an opportunistic lifestyle that provides a considerable advantage in the generally food resource-limited marine environments.}, }
@article {pmid35024989, year = {2022}, author = {Cicuttin, GL and De Salvo, MN and Venzal, JM and Nava, S}, title = {Rickettsia spp., Ehrlichia sp. and Candidatus Midichloria sp. associated to ticks from a protected urban area in Buenos Aires City (Argentina).}, journal = {Experimental &amp; applied acarology}, volume = {86}, number = {2}, pages = {271-282}, pmid = {35024989}, issn = {1572-9702}, mesh = {Animals ; Argentina ; Ehrlichia/genetics ; *Ixodes/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Rickettsia/genetics ; }, abstract = {The aim of this study was to determine the infection with Rickettsiales in ticks and birds from the main protected urban area of Buenos Aires City (Argentina). One Amblyomma aureolatum (0.2%) and one Ixodes auritulus (0.1%) were positive by PCR targeting Rickettsia 23S-5S rRNA intergenic spacer. Phylogenetic analysis shows to findings in A. aureolatum are closely to Rickettsia bellii and for I. auritulus are related to 'Candidatus Rickettsia mendelii'. One I. auritulus (0.1%) and three A. aureolatum (0.6%) were positive by PCR for a fragment of the 16S rRNA gene of the Anaplasmataceae family. The sequences obtained from A. aureolatum were phylogenetically related to Midichloriaceae endosymbionts. The sequence from I. auritulus s.l. had 100% identity with Ehrlichia sp. Magellanica from Chile and two genotypes of Ehrlichia sp. from Uruguay. The results of our study show that Rickettsia and Ehrlichia are present in ticks in the main protected urban area of Buenos Aires City.}, }
@article {pmid35023810, year = {2022}, author = {Udayan, S and Stamou, P and Crispie, F and Hickey, A and Floyd, AN and Hsieh, CS and Cotter, PD and O'Sullivan, O and Melgar, S and O'Toole, PW and Newberry, RD and Rossini, V and Nally, K}, title = {Identification of Gut Bacteria such as Lactobacillus johnsonii that Disseminate to Systemic Tissues of Wild Type and MyD88-/- Mice.}, journal = {Gut microbes}, volume = {14}, number = {1}, pages = {2007743}, pmid = {35023810}, issn = {1949-0984}, support = {R01 DK097317/DK/NIDDK NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Dendritic Cells/microbiology ; *Gastrointestinal Microbiome ; Gastrointestinal Tract/microbiology ; Lactobacillus johnsonii/genetics/*physiology ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Myeloid Differentiation Factor 88/*deficiency/genetics ; }, abstract = {In healthy hosts the gut microbiota is restricted to gut tissues by several barriers some of which require MyD88-dependent innate immune sensor pathways. Nevertheless, some gut taxa have been reported to disseminate to systemic tissues. However, the extent to which this normally occurs during homeostasis in healthy organisms is still unknown. In this study, we recovered viable gut bacteria from systemic tissues of healthy wild type (WT) and MyD88[-/-] mice. Shotgun metagenomic-sequencing revealed a marked increase in the relative abundance of L. johnsonii in intestinal tissues of MyD88[-/-] mice compared to WT mice. Lactobacillus johnsonii was detected most frequently from multiple systemic tissues and at higher levels in MyD88[-/-] mice compared to WT mice. Viable L. johnsonii strains were recovered from different cell types sorted from intestinal and systemic tissues of WT and MyD88[-/-] mice. L. johnsonii could persist in dendritic cells and may represent murine immunomodulatory endosymbionts.}, }
@article {pmid35019702, year = {2022}, author = {Cibichakravarthy, B and Oses-Prieto, JA and Ben-Yosef, M and Burlingame, AL and Karr, TL and Gottlieb, Y}, title = {Comparative Proteomics of Coxiella like Endosymbionts (CLEs) in the Symbiotic Organs of Rhipicephalus sanguineus Ticks.}, journal = {Microbiology spectrum}, volume = {10}, number = {1}, pages = {e0167321}, pmid = {35019702}, issn = {2165-0497}, support = {P41 GM103481/GM/NIGMS NIH HHS/United States ; S10 OD016229/OD/NIH HHS/United States ; }, mesh = {Animals ; Coxiella/genetics/*metabolism ; Dogs ; Female ; Gene Ontology ; Malpighian Tubules ; Ovary ; *Proteomics ; Rhipicephalus ; Rhipicephalus sanguineus ; Symbiosis/*physiology ; }, abstract = {Maternally transmitted obligatory endosymbionts are found in the female gonads as well as in somatic tissue and are expected to provide missing metabolite to their hosts. These deficiencies are presumably complemented through specific symbiotic microorganisms such as Coxiella-like endosymbionts (CLEs) of Rhipicephalus ticks. CLEs are localized in specialized host tissue cells within the Malpighian tubules (Mt) and the ovaries (Ov) from which they are maternally transmitted to developing oocytes. These two organs differ in function and cell types, but the role of CLEs in these tissues is unknown. To probe possible functions of CLEs, comparative proteomics was performed between Mt and Ov of R. sanguineus ticks. Altogether, a total of 580 and 614 CLE proteins were identified in Mt and Ov, respectively. Of these, 276 CLE proteins were more abundant in Mt, of which 12 were significantly differentially abundant. In Ov, 290 CLE proteins were more abundant, of which 16 were significantly differentially abundant. Gene Ontology analysis revealed that most of the proteins enriched in Mt are related to cellular metabolic functions and stress responses, whereas in Ov, the majority were related to cell proliferation suggesting CLEs function differentially and interdependently with host requirements specific to each organ. The results suggest Mt CLEs provide essential nutrients to its host and Ov CLEs promote proliferation and vertical transmission to tick progeny. IMPORTANCE Here we compare the Coxiella-like endosymbionts (CLEs) proteomes from Malpighian tubule (Mt) and the ovaries (Ov) of the brown dog tick Rhipicephalus sanguineus. Our results support the hypothesis that CLEs function interdependently with host requirements in each of the organs. The different functional specificity of CLE in the same host suggest that metabolic capabilities evolved according to the constrains imposed by the specific organ function and requirements. Our findings provide specific CLE protein targets that can be useful for future studies of CLE biology with a focus on tick population control.}, }
@article {pmid35019223, year = {2022}, author = {Richardson, KM and Schiffer, M and Ross, PA and Thia, JA and Hoffmann, AA}, title = {Characterization of the first Wolbachia from the genus Scaptodrosophila, a male-killer from the rainforest species S. claytoni.}, journal = {Insect science}, volume = {29}, number = {5}, pages = {1401-1413}, doi = {10.1111/1744-7917.13000}, pmid = {35019223}, issn = {1744-7917}, mesh = {Animals ; Drosophila/genetics ; Female ; Male ; Multilocus Sequence Typing ; Phylogeny ; Rainforest ; Tetracyclines ; *Wolbachia/genetics ; }, abstract = {The Scaptodrosophila genus represents a large group of drosophilids with a worldwide distribution and a predominance of species in Australia, but there is little information on the presence and impacts of Wolbachia endosymbionts in this group. Here we describe the first Wolbachia infection from this group, wClay isolated from Scaptodrosophila claytoni (van Klinken), a species from the east coast of Australia. The infection is polymorphic in natural populations, occurring at a frequency of around 6%-10%. wClay causes male killing, producing female-biased lines; most lines showed 100% male killing, though in 1 line it was <80%. The lines need to be maintained through the introduction of males unless the infection is removed by tetracycline treatment. wClay is transmitted at a high fidelity (98.6%) through the maternal lineage and has been stable in 2 laboratory lines across 24 generations, suggesting it is likely to persist in populations. The infection has not been previously described but is closely related to the male-killing Wolbachia recently described from Drosophila pandora based on multilocus sequence typing and the wsp gene. Male-killing Wolbachia are likely to be common in drosophilids but remain difficult to detect because the infections can often be at a low frequency.}, }
@article {pmid35013476, year = {2022}, author = {Towett-Kirui, S and Morrow, JL and Riegler, M}, title = {Substantial rearrangements, single nucleotide frameshift deletion and low diversity in mitogenome of Wolbachia-infected strepsipteran endoparasitoid in comparison to its tephritid hosts.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {477}, pmid = {35013476}, issn = {2045-2322}, mesh = {Animals ; Australia ; Frameshift Mutation ; Gene Rearrangement ; *Genome, Insect ; *Genome, Mitochondrial ; Insect Proteins/genetics ; Sequence Deletion ; Tephritidae/classification/*genetics/*microbiology/physiology ; Wolbachia/*physiology ; }, abstract = {Insect mitogenome organisation is highly conserved, yet, some insects, especially with parasitic life cycles, have rearranged mitogenomes. Furthermore, intraspecific mitochondrial diversity can be reduced by fitness-affecting bacterial endosymbionts like Wolbachia due to their maternal coinheritance with mitochondria. We have sequenced mitogenomes of the Wolbachia-infected endoparasitoid Dipterophagus daci (Strepsiptera: Halictophagidae) and four of its 22 known tephritid fruit fly host species using total genomic extracts of parasitised flies collected across > 700 km in Australia. This halictophagid mitogenome revealed extensive rearrangements relative to the four fly mitogenomes which exhibited the ancestral insect mitogenome pattern. Compared to the only four available other strepsipteran mitogenomes, the D. daci mitogenome had additional transpositions of one rRNA and two tRNA genes, and a single nucleotide frameshift deletion in nad5 requiring translational frameshifting or, alternatively, resulting in a large protein truncation. Dipterophagus daci displays an almost completely endoparasitic life cycle when compared to Strepsiptera that have maintained the ancestral state of free-living adults. Our results support the hypothesis that the transition to extreme endoparasitism evolved together with increased levels of mitogenome changes. Furthermore, intraspecific mitogenome diversity was substantially smaller in D. daci than the parasitised flies suggesting Wolbachia reduced mitochondrial diversity because of a role in D. daci fitness.}, }
@article {pmid35006317, year = {2022}, author = {Schlabe, S and Korir, P and Lämmer, C and Landmann, F and Dubben, B and Koschel, M and Albers, A and Debrah, LB and Debrah, AY and Hübner, MP and Pfarr, K and Klarmann-Schulz, U and Hoerauf, A}, title = {A qPCR to quantify Wolbachia from few Onchocerca volvulus microfilariae as a surrogate for adult worm histology in clinical trials of antiwolbachial drugs.}, journal = {Parasitology research}, volume = {121}, number = {4}, pages = {1199-1206}, pmid = {35006317}, issn = {1432-1955}, mesh = {Animals ; *Filarioidea ; Humans ; *Intestinal Volvulus ; Microfilariae ; Onchocerca ; *Onchocerca volvulus/genetics ; *Onchocerciasis/drug therapy ; Reproducibility of Results ; *Wolbachia/genetics ; }, abstract = {The filarial nematode Onchocerca volvulus causes onchocerciasis (river blindness), a neglected tropical disease affecting 21 million people, mostly in Sub-Saharan Africa. Targeting the endosymbiont Wolbachia with antibiotics leads to permanent sterilization and killing of adult worms. The gold standard to assess Wolbachia depletion is the histological examination of adult worms in nodules beginning at 6 months post-treatment. However, nodules can only be used once, limiting the time points to monitor Wolbachia depletion. A diagnostic to longitudinally monitor Wolbachia depletion from microfilariae (MF) at more frequent intervals < 6 months post-treatment would accelerate clinical trials of antiwolbachials. We developed a TaqMan qPCR amplifying the single-copy gene wOvftsZ to quantify Wolbachia from as few as one MF that had migrated from skin biopsies and compared quantification using circular and linearized plasmids or synthetic dsDNA (gBlock®). qPCR for MF from the rodent nematode Litomosoides sigmodontis was used to support the reproducibility and validate the principle. The qPCR using as few as 2 MF from O. volvulus and L. sigmodontis reproducibly quantified Wolbachia. Use of a linearized plasmid standard or synthesized dsDNA resulted in numbers of Wolbachia/MF congruent with biologically plausible estimates in O. volvulus and L. sigmodontis MF. The qPCR assay yielded a median of 48.8 (range 1.5-280.5) Wolbachia/O. volvulus MF. The qPCR is a sensitive tool for quantifying Wolbachia in a few MF from skin biopsies and allows for establishing the qPCR as a surrogate parameter for monitoring Wolbachia depletion in adult worms of new antiwolbachial candidates.}, }
@article {pmid35006065, year = {2022}, author = {Leitner, M and Etebari, K and Asgari, S}, title = {Transcriptional response of Wolbachia-transinfected Aedes aegypti mosquito cells to dengue virus at early stages of infection.}, journal = {The Journal of general virology}, volume = {103}, number = {1}, pages = {}, pmid = {35006065}, issn = {1465-2099}, mesh = {Aedes/microbiology/*virology ; Animals ; Dengue/*virology ; Dengue Virus/*genetics/physiology ; Host Microbial Interactions ; Humans ; Mosquito Vectors/microbiology/virology ; RNA, Long Noncoding ; Sumoylation ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {Mosquito-borne flaviviruses are responsible for viral infections and represent a considerable public health burden. Aedes aegypti is the principal vector of dengue virus (DENV), therefore understanding the intrinsic virus-host interactions is vital, particularly in the presence of the endosymbiont Wolbachia, which blocks virus replication in mosquitoes. Here, we examined the transcriptional response of Wolbachia-transinfected Ae. aegypti Aag2 cells to DENV infection. We identified differentially expressed immune genes that play a key role in the activation of anti-viral defence such as the Toll and immune deficiency pathways. Further, genes encoding cytosine and N[6]-adenosine methyltransferases and SUMOylation, involved in post-transcriptional modifications, an antioxidant enzyme, and heat-shock response were up-regulated at the early stages of DENV infection and are reported here for the first time. Additionally, several long non-coding RNAs were among the differentially regulated genes. Our results provide insight into Wolbachia-transinfected Ae. aegypti's initial virus recognition and transcriptional response to DENV infection.}, }
@article {pmid35003655, year = {2021}, author = {El Hamss, H and Ghosh, S and Maruthi, MN and Delatte, H and Colvin, J}, title = {Microbiome diversity and reproductive incompatibility induced by the prevalent endosymbiont Arsenophonus in two species of African cassava Bemisia tabaci whiteflies.}, journal = {Ecology and evolution}, volume = {11}, number = {24}, pages = {18032-18041}, pmid = {35003655}, issn = {2045-7758}, abstract = {A minimum of 13 diverse whitefly species belonging to the Bemisia tabaci (B. tabaci) species complex are known to infest cassava crops in sub-Saharan Africa (SSA), designated as SSA1-13. Of these, the SSA1 and SSA2 are the predominant species colonizing cassava crops in East Africa. The SSA species of B. tabaci harbor diverse bacterial endosymbionts, many of which are known to manipulate insect reproduction. One such symbiont, Arsenophonus, is known to drive its spread by inducing reproductive incompatibility in its insect host and are abundant in SSA species of B. tabaci. However, whether Arsenophonus affects the reproduction of SSA species is unknown. In this study, we investigated both the reproductive compatibility between Arsenophonus infected and uninfected whiteflies by inter-/intraspecific crossing experiments involving the sub-group three haplotypes of the SSA1 (SSA1-SG3), SSA2 species, and their microbial diversity. The number of eggs, nymphs, progenies produced, hatching rate, and survival rate were recorded for each cross. In intra-specific crossing trials, both male and female progenies were produced and thus demonstrated no reproductive incompatibility. However, the total number of eggs laid, nymphs hatched, and the emerged females were low in the intra-species crosses of SSA1-SG3A+, indicating the negative effect of Arsenophonus on whitefly fitness. In contrast, the inter-species crosses between the SSA1-SG3 and SSA2 produced no female progeny and thus demonstrated reproductive incompatibility. The relative frequency of other bacteria colonizing the whiteflies was also investigated using Illumina sequencing of 16S rDNA and diversity indices were recorded. Overall, SSA1-SG3 and SSA2 harbored high microbial diversity with more than 137 bacteria discovered. These results described for the first time the microbiome diversity and the reproductive behaviors of intra-/inter-species of Arsenophonus in whitefly reproduction, which is crucial for understanding the invasion abilities of cassava whiteflies.}, }
@article {pmid34996906, year = {2022}, author = {Neupane, S and Bonilla, SI and Manalo, AM and Pelz-Stelinski, KS}, title = {Complete de novo assembly of Wolbachia endosymbiont of Diaphorina citri Kuwayama (Hemiptera: Liviidae) using long-read genome sequencing.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {125}, pmid = {34996906}, issn = {2045-2322}, mesh = {Animals ; Cell Line ; *Chromosomes, Bacterial ; DNA, Bacterial/*genetics ; DNA, Circular/*genetics ; *Genes, Bacterial ; *Genome, Bacterial ; Hemiptera/*microbiology ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; *Whole Genome Sequencing ; Wolbachia/*genetics ; }, abstract = {Wolbachia, a gram-negative [Formula: see text]-proteobacterium, is an endosymbiont found in some arthropods and nematodes. Diaphorina citri Kuwayama, the vector of 'Candidatus Liberibacter asiaticus' (CLas), are naturally infected with a strain of Wolbachia (wDi), which has been shown to colocalize with the bacteria pathogens CLas, the pathogen associated with huanglongbing (HLB) disease of citrus. The relationship between wDi and CLas is poorly understood in part because the complete genome of wDi has not been available. Using high-quality long-read PacBio circular consensus sequences, we present the largest complete circular wDi genome among supergroup-B members. The assembled circular chromosome is 1.52 megabases with 95.7% genome completeness with contamination of 1.45%, as assessed by checkM. We identified Insertion Sequences (ISs) and prophage genes scattered throughout the genomes. The proteins were annotated using Pfam, eggNOG, and COG that assigned unique domains and functions. The wDi genome was compared with previously sequenced Wolbachia genomes using pangenome and phylogenetic analyses. The availability of a complete circular chromosome of wDi will facilitate understanding of its role within the insect vector, which may assist in developing tools for disease management. This information also provides a baseline for understanding phylogenetic relationships among Wolbachia of other insect vectors.}, }
@article {pmid34995739, year = {2022}, author = {Cejp, B and Ravara, A and Aguado, MT}, title = {First mitochondrial genomes of Chrysopetalidae (Annelida) from shallow-water and deep-sea chemosynthetic environments.}, journal = {Gene}, volume = {815}, number = {}, pages = {146159}, doi = {10.1016/j.gene.2021.146159}, pmid = {34995739}, issn = {1879-0038}, mesh = {Animals ; Codon Usage ; Ecosystem ; *Genome, Mitochondrial ; *Phylogeny ; Polychaeta/*genetics ; Proteins/genetics ; RNA, Transfer/genetics ; *Selection, Genetic ; Symbiosis ; Water ; }, abstract = {Among Annelida, Chrysopetalidae is an ecologically and morphologically diverse group, which includes shallow-water, deep-sea, free-living, and symbiotic species. Here, the four first mitochondrial genomes of this group are presented and described. One of the free-living shallow-water species Chrysopetalum debile (Chrysopetalinae), one of the yet undescribed free-living deep-sea species Boudemos sp., and those of the two deep-sea bivalve endosymbionts Craseoschema thyasiricola and Iheyomytilidicola lauensis (Calamyzinae). An updated phylogeny of Chrysopetalidae is performed, which supports previous phylogenetic hypotheses within Chrysopetalinae and indicates a complex ecological evolution within Calamyzinae. Additionally, analyses of natural selection pressure in the four mitochondrial genomes and additional genes from the two shallow-water species Bhawania goodei and Arichlidon gathofi were performed. Relaxed selection pressure in the mitochondrion of deep-sea and symbiotic species was found, with many sites under selection identified in the COX3 gene of deep-sea species.}, }
@article {pmid34981990, year = {2022}, author = {Peta, V and Tantely, LM and Potts, R and Girod, R and Pietri, JE}, title = {A Francisella tularensis-Like Bacterium in Tropical Bed Bugs from Madagascar.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {22}, number = {1}, pages = {58-61}, doi = {10.1089/vbz.2021.0079}, pmid = {34981990}, issn = {1557-7759}, mesh = {Animals ; *Bedbugs/microbiology ; *Francisella ; Insect Vectors/microbiology ; Madagascar/epidemiology ; }, abstract = {The genus Francisella includes several highly virulent human pathogens and some tick endosymbionts. Francisella infections are acquired by humans through contact with vertebrate animal reservoirs or contaminated water or dust. The species Francisella tularensis can also be transmitted by arthropods including ticks, mosquitoes, and flies. For the first time, we describe the molecular detection of an F. tularensis-like bacterium in bed bugs from samples collected in rural Madagascar. This finding suggests a potential involvement of bed bugs in the ecology of Francisella. The role of bed bugs as possible hosts, reservoirs, or vectors of Francisella spp. should be further investigated.}, }
@article {pmid34980289, year = {2022}, author = {Yang, Y and Sun, J and Chen, C and Zhou, Y and Van Dover, CL and Wang, C and Qiu, JW and Qian, PY}, title = {Metagenomic and metatranscriptomic analyses reveal minor-yet-crucial roles of gut microbiome in deep-sea hydrothermal vent snail.}, journal = {Animal microbiome}, volume = {4}, number = {1}, pages = {3}, pmid = {34980289}, issn = {2524-4671}, abstract = {BACKGROUND: Marine animals often exhibit complex symbiotic relationship with gut microbes to attain better use of the available resources. Many animals endemic to deep-sea chemosynthetic ecosystems host chemoautotrophic bacteria endocellularly, and they are thought to rely entirely on these symbionts for energy and nutrition. Numerous investigations have been conducted on the interdependence between these animal hosts and their chemoautotrophic symbionts. The provannid snail Alviniconcha marisindica from the Indian Ocean hydrothermal vent fields hosts a Campylobacterial endosymbiont in its gill. Unlike many other chemosymbiotic animals, the gut of A. marisindica is reduced but remains functional; yet the contribution of gut microbiomes and their interactions with the host remain poorly characterised.<br><br>RESULTS: Metagenomic and metatranscriptomic analyses showed that the gut microbiome of A. marisindica plays key nutritional and metabolic roles. The composition and relative abundance of gut microbiota of A. marisindica were different from those of snails that do not depend on endosymbiosis. The relative abundance of microbial taxa was similar amongst three individuals of A. marisindica with significant inter-taxa correlations. These correlations suggest the potential for interactions between taxa that may influence community assembly and stability. Functional profiles of the gut microbiome revealed thousands of additional genes that assist in the use of vent-supplied inorganic compounds (autotrophic energy source), digest host-ingested organics (carbon source), and recycle the metabolic waste of the host. In addition, members of five taxonomic classes have the potential to form slime capsules&#xa0;to protect themselves from the host immune system, thereby contributing to homeostasis. Gut microbial ecology and its interplay with the host thus contribute to the nutritional and metabolic demands of A. marisindica.<br><br>CONCLUSIONS: The findings advance the understanding of how deep-sea chemosymbiotic animals use available resources through contributions from gut microbiota. Gut microbiota may be critical in the survival of invertebrate hosts with autotrophic endosymbionts in extreme environments.}, }
@article {pmid34967937, year = {2021}, author = {Singh, PP and Srivastava, D and Shukla, S and Varsha, }, title = {Rhizophagus proliferus genome sequence reiterates conservation of genetic traits in AM fungi, but predicts higher saprotrophic activity.}, journal = {Archives of microbiology}, volume = {204}, number = {1}, pages = {105}, pmid = {34967937}, issn = {1432-072X}, mesh = {Fungi ; Genome, Fungal ; Genomics ; Humans ; *Mycorrhizae/genetics ; Plants ; Soil ; }, abstract = {Arbuscular mycorrhizal (AM) fungi are ubiquitous endosymbionts of terrestrial plants. It helps plants to extract more nutrients from the soil and enhances the plant tolerance to various ecological stress factors. The AM fungal genome sequence helps to identify the gene repertoires that are crucial for adaptation to different habitat and mechanisms for interaction with host plant. The present work comprises the first draft of the genome sequence of Rhizophagus proliferus, which is an important AM species present in biofertilizer consortia for agricultural purpose. The estimated genome size of R. proliferus is ~ 110 Mbps and its genomic assembly is 94.35% complete. Genome mining was carried out to identify putative gene families important for biological functions. A total of 22,526 protein-coding genes were estimated in the genome, with an abundance of kinases and reduced number of glycoside hydrolases as compared to other fungal classes. A striking finding in the R. proliferus genome was higher number of carbohydrate esterases (CE), which may suggest towards presence of higher saprotrophic activity in this species as compared to the previously reported AM fungi, which may indicate towards its role as a link between plants and soil mineral nutrients. The genome sequence and annotation of R. proliferus presented here would serve as an important reference for functional genomics studies required for developing biofertilizer formulations in future. In addition, the findings from this work may also prove important in deciphering molecular mechanisms in AM fungi that govern the host-specific interaction and associated agriculture benefits.}, }
@article {pmid34955690, year = {2021}, author = {Sánchez-Suárez, J and Garnica-Agudelo, M and Villamil, L and Díaz, L and Coy-Barrera, E}, title = {Bioactivity and Biotechnological Overview of Naturally Occurring Compounds from the Dinoflagellate Family Symbiodiniaceae: A Systematic Review.}, journal = {TheScientificWorldJournal}, volume = {2021}, number = {}, pages = {1983589}, pmid = {34955690}, issn = {1537-744X}, mesh = {Biological Products/*pharmacology ; *Biotechnology ; Dinoflagellida/*chemistry ; }, abstract = {Marine invertebrates are a significant source of biologically active compounds. Recent studies have highlighted the role of microbiota associated with marine invertebrates in the production of bioactive compounds. Corals and sponges are the main marine invertebrates producing bioactive substances, and Symbiodiniaceae dinoflagellates are well-recognized endosymbionts with corals and sponges playing vital functions. The biological properties of Symbiodiniaceae-derived compounds have garnered attention in the past decades owing to their ecological implications and potentiality for bioprospecting initiatives. This study aims to systematically review studies on bioactivities and potential biotechnological applications of Symbiodiniaceae-derived compounds. The PRISMA guidelines were followed. Our study showed that anti-inflammatory and vasoconstrictive activities of Symbiodiniaceae-derived compounds have been the most investigated. However, very few studies have been published, with in vitro culturing of Symbiodiniaceae being the most significant challenge. Therefore, we surveyed for the metabolites reported so far, analyzed their chemodiversity, and discussed approaches to overcome culturing-related limitations.}, }
@article {pmid34954414, year = {2022}, author = {Namias, A and Sicard, M and Weill, M and Charlat, S}, title = {From Wolbachia genomics to phenotype: molecular models of cytoplasmic incompatibility must account for the multiplicity of compatibility types.}, journal = {Current opinion in insect science}, volume = {49}, number = {}, pages = {78-84}, doi = {10.1016/j.cois.2021.12.005}, pmid = {34954414}, issn = {2214-5753}, mesh = {Animals ; Antidotes ; Genomics ; Male ; Models, Molecular ; Phenotype ; *Wolbachia/genetics ; }, abstract = {Wolbachia endosymbionts commonly induce cytoplasmic incompatibility, making infected males' sperm lethal to the embryos unless these are rescued by the same bacterium, inherited from their mother. Causal genes were recently identified but two families of mechanistic models are still opposed. In the toxin-antidote model, interaction between the toxin and the antidote is required for rescuing the embryos. In host modification models, a host factor is misregulated in sperm and rescue occurs through compensation or withdrawal of this modification. While these models have been thoroughly discussed, the multiplicity of compatibility types, that is, the existence of many mutually incompatible strains, as seen in Culex mosquitoes, has not received sufficient attention. To explain such a fact, host modification models must posit that the same embryonic defects can be induced and rescued through a large variety of host targets. Conversely, the toxin-antidote model simply accommodates this pattern in a lock-key fashion, through variations in the toxin-antidote interaction sites.}, }
@article {pmid34953157, year = {2022}, author = {Røed, ES and Engelstädter, J}, title = {Cytoplasmic incompatibility in hybrid zones: infection dynamics and resistance evolution.}, journal = {Journal of evolutionary biology}, volume = {35}, number = {2}, pages = {240-253}, doi = {10.1111/jeb.13974}, pmid = {34953157}, issn = {1420-9101}, mesh = {Animals ; *Arthropods ; Cytoplasm ; Female ; Male ; Reproduction ; Symbiosis ; *Wolbachia ; }, abstract = {Cytoplasmic incompatibility is an endosymbiont-induced mating incompatibility common in arthropods. Unidirectional cytoplasmic incompatibility impairs crosses between infected males and uninfected females, whereas bidirectional cytoplasmic incompatibility occurs when two host lineages are infected with reciprocally incompatible endosymbionts. Bidirectional cytoplasmic incompatibility is unstable in unstructured populations, but may be stable in hybrid zones. Stable coexistence of incompatible host lineages should generate frequent incompatible crosses. Therefore, hosts are expected to be under selection to resist their endosymbionts. Here, we formulate a mathematical model of hybrid zones where two bidirectionally incompatible host lineages meet. We expand this model to consider the invasion of a hypothetical resistance allele. To corroborate our mathematical predictions, we test each prediction with stochastic, individual-based simulations. Our models suggest that hybrid zones may sustain stable coinfections of bidirectionally incompatible endosymbiont strains. Over a range of conditions, hosts are under selection for resistance against cytoplasmic incompatibility. Under asymmetric migration, a resistance allele can facilitate infection turnover and subsequently either persist or become lost. The predictions we present may inform our understanding of the cophylogenetic relationship between the endosymbiont Wolbachia and its hosts.}, }
@article {pmid34946034, year = {2021}, author = {Sonenshine, DE and Stewart, PE}, title = {Microbiomes of Blood-Feeding Arthropods: Genes Coding for Essential Nutrients and Relation to Vector Fitness and Pathogenic Infections. A Review.}, journal = {Microorganisms}, volume = {9}, number = {12}, pages = {}, pmid = {34946034}, issn = {2076-2607}, abstract = {Blood-feeding arthropods support a diverse array of symbiotic microbes, some of which facilitate host growth and development whereas others are detrimental to vector-borne pathogens. We found a common core constituency among the microbiota of 16 different arthropod blood-sucking disease vectors, including Bacillaceae, Rickettsiaceae, Anaplasmataceae, Sphingomonadaceae, Enterobacteriaceae, Pseudomonadaceae, Moraxellaceae and Staphylococcaceae. By comparing 21 genomes of common bacterial symbionts in blood-feeding vectors versus non-blooding insects, we found that certain enteric bacteria benefit their hosts by upregulating numerous genes coding for essential nutrients. Bacteria of blood-sucking vectors expressed significantly more genes (p < 0.001) coding for these essential nutrients than those of non-blooding insects. Moreover, compared to endosymbionts, the genomes of enteric bacteria also contained significantly more genes (p < 0.001) that code for the synthesis of essential amino acids and proteins that detoxify reactive oxygen species. In contrast, microbes in non-blood-feeding insects expressed few gene families coding for these nutrient categories. We also discuss specific midgut bacteria essential for the normal development of pathogens (e.g., Leishmania) versus others that were detrimental (e.g., bacterial toxins in mosquitoes lethal to Plasmodium spp.).}, }
@article {pmid34939561, year = {2021}, author = {Moran, NA}, title = {Microbe Profile: Buchnera aphidicola: ancient aphid accomplice and endosymbiont exemplar.}, journal = {Microbiology (Reading, England)}, volume = {167}, number = {12}, pages = {}, doi = {10.1099/mic.0.001127}, pmid = {34939561}, issn = {1465-2080}, support = {R35 GM131738/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Aphids ; *Buchnera/genetics/metabolism ; Phylogeny ; Symbiosis/genetics ; }, abstract = {Buchnera aphidicola is an obligate endosymbiont of aphids that cannot be cultured outside of hosts. It exists as diverse strains in different aphid species, and phylogenetic reconstructions show that it has been maternally transmitted in aphids for >100 million years. B. aphidicola genomes are highly reduced and show conserved gene order and no gene acquisition, but encoded proteins undergo rapid evolution. Aphids depend on B. aphidicola for biosynthesis of essential amino acids and as an integral part of embryonic development. How B. aphidicola populations are regulated within hosts remains little known.}, }
@article {pmid34933456, year = {2021}, author = {Smith, TE and Lee, M and Person, MD and Hesek, D and Mobashery, S and Moran, NA}, title = {Horizontal-Acquisition of a Promiscuous Peptidoglycan-Recycling Enzyme Enables Aphids To Influence Symbiont Cell Wall Metabolism.}, journal = {mBio}, volume = {12}, number = {6}, pages = {e0263621}, pmid = {34933456}, issn = {2150-7511}, support = {R35 GM131685/GM/NIGMS NIH HHS/United States ; F32 GM126706/GM/NIGMS NIH HHS/United States ; R35 GM131738/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aphids/*enzymology/genetics/microbiology/physiology ; Bacterial Proteins/*genetics/metabolism ; Buchnera/*enzymology/genetics/metabolism ; Cell Wall/genetics/*metabolism ; *Gene Transfer, Horizontal ; Insect Proteins/*genetics/metabolism ; N-Acetylmuramoyl-L-alanine Amidase/*genetics/metabolism ; Peptidoglycan/*biosynthesis ; Symbiosis ; }, abstract = {During evolution, enzymes can undergo shifts in preferred substrates or in catalytic activities. An intriguing question is how enzyme function changes following horizontal gene transfer, especially for bacterial genes that have moved to animal genomes. Some insects have acquired genes that encode enzymes for the biosynthesis of bacterial cell wall components and that appear to function to support or control their obligate endosymbiotic bacteria. In aphids, the bacterial endosymbiont Buchnera aphidicola provides essential amino acids for aphid hosts but lacks most genes for remodeling of the bacterial cell wall. The aphid genome has acquired seven genes with putative functions in cell wall metabolism that are primarily expressed in the aphid cells harboring Buchnera. In analyses of aphid homogenates, we detected peptidoglycan (PGN) muropeptides indicative of the reactions of PGN hydrolases encoded by horizontally acquired aphid genes but not by Buchnera genes. We produced one such host enzyme, ApLdcA, and characterized its activity with both cell wall derived and synthetic PGN. Both ApLdcA and the homologous enzyme in Escherichia coli, which functions as an l,d-carboxypeptidase in the cytoplasmic PGN recycling pathway, exhibit turnover of PGN substrates containing stem pentapeptides and cross-linkages via l,d-endopeptidase activity, consistent with a potential role in cell wall remodeling. Our results suggest that ApLdcA derives its functions from the promiscuous activities of an ancestral LdcA enzyme, whose acquisition by the aphid genome may have enabled hosts to influence Buchnera cell wall metabolism as a means to control symbiont growth and division. IMPORTANCE Most enzymes are capable of performing biologically irrelevant side reactions. During evolution, promiscuous enzyme activities may acquire new biological roles, especially after horizontal gene transfer to new organisms. Pea aphids harbor obligate bacterial symbionts called Buchnera and encode horizontally acquired bacterial genes with putative roles in cell wall metabolism. Though Buchnera lacks cell wall endopeptidase genes, we found evidence of endopeptidase activity among peptidoglycan muropeptides purified from aphids. We characterized a multifunctional, aphid-encoded enzyme, ApLdcA, which displays l,d-endopeptidase activities considered promiscuous for the Escherichia coli homolog, for which these activities do not contribute to its native role in peptidoglycan recycling. These results exemplify the roles of enzyme promiscuity and horizontal gene transfer in enzyme evolution and demonstrate how aphids influence symbiont cell wall metabolism.}, }
@article {pmid34932865, year = {2022}, author = {Wheelhouse, N and Hearn, J and Livingstone, M and Flockhart, A and Dagleish, M and Longbottom, D}, title = {Identification of Parachlamydiaceae DNA in nasal and rectal passages of healthy dairy cattle.}, journal = {Journal of applied microbiology}, volume = {132}, number = {4}, pages = {2642-2648}, doi = {10.1111/jam.15422}, pmid = {34932865}, issn = {1365-2672}, mesh = {Animals ; Cattle ; *Chlamydiales/genetics ; DNA ; DNA, Bacterial/analysis/genetics ; Female ; Pregnancy ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {AIMS: The order Chlamydiales comprises a broad range of bacterial pathogens and endosymbionts, which infect a wide variety of host species. Within this order, members of the family Parachlamydiaceae, which includes Parachlamydia and Neochlamydia species, have been particularly associated with infections in both humans and cattle, including having a potential pathogenic role in cases of bovine abortion. While the route of transmission has yet to be defined, it has been hypothesised that asymptomatic carriage and contamination of the immediate environment may be a route of inter-animal transmission. We investigated the asymptomatic carriage of Chlamydia-related organisms in healthy cattle.<br><br>METHODS &amp; RESULTS: DNA was isolated from nasal and rectal swabs obtained from 38&#xa0;healthy dairy heifers. A Chlamydiales sp. 16S rRNA qPCR was performed on each sample. A total of 18/38 nasal samples and all 38/38 rectal samples were identified as positive for Chlamydiales sp. Each positive sample was sequenced confirming the presence of DNA belonging to the Parachlamydiaceae.<br><br>CONCLUSIONS: The presence of Parachlamydiaceae DNA in nasal and rectal swab samples of healthy cattle provides evidence for the asymptomatic carriage of parachlamydial organisms within cattle.<br><br>The study provides evidence of potential routes of environmental contamination that could provide a route for inter-animal and animal transmission of Parachlamydiaceae.}, }
@article {pmid34928947, year = {2021}, author = {Vivero-Gomez, RJ and Castañeda-Monsalve, VA and Atencia, MC and Hoyos-Lopez, R and Hurst, GD and Cadavid-Restrepo, G and Moreno-Herrera, CX}, title = {Molecular phylogeny of heritable symbionts and microbiota diversity analysis in phlebotominae sand flies and Culex nigripalpus from Colombia.}, journal = {PLoS neglected tropical diseases}, volume = {15}, number = {12}, pages = {e0009942}, pmid = {34928947}, issn = {1935-2735}, mesh = {Animals ; Bacteroidetes/classification/genetics/*isolation &amp; purification/physiology ; Biodiversity ; Colombia ; Culex/*microbiology/physiology ; *Microbiota ; Microsporidia/classification/genetics/*isolation &amp; purification/physiology ; *Phylogeny ; Psychodidae/*microbiology/physiology ; Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {BACKGROUND: Secondary symbionts of insects include a range of bacteria and fungi that perform various functional roles on their hosts, such as fitness, tolerance to heat stress, susceptibility to insecticides and effects on reproduction. These endosymbionts could have the potential to shape microbial communites and high potential to develop strategies for mosquito-borne disease control.<br><br>The relative frequency and molecular phylogeny of Wolbachia, Microsporidia and Cardinium were determined of phlebotomine sand flies and mosquitoes in two regions from Colombia. Illumina Miseq using the 16S rRNA gene as a biomarker was conducted to examine the microbiota. Different percentages of natural infection by Wolbachia, Cardinium, and Microsporidia in phlebotomines and mosquitoes were detected. Phylogenetic analysis of Wolbachia shows putative new strains of Lutzomyia gomezi (wLgom), Brumptomyia hamata (wBrham), and a putative new group associated with Culex nigripalpus (Cnig) from the Andean region, located in Supergroup A and Supergroup B, respectively. The sequences of Microsporidia were obtained of Pi. pia and Cx. nigripalpus, which are located on phylogeny in the IV clade (terrestrial origin). The Cardinium of Tr. triramula and Ps. shannoni were located in group C next to Culicoides sequences while Cardinium of Mi. cayennensis formed two putative new subgroups of Cardinium in group A. In total were obtained 550 bacterial amplicon sequence variants (ASVs) and 189 taxa to the genus level. The microbiota profiles of Sand flies and mosquitoes showed mainly at the phylum level to Proteobacteria (67.6%), Firmicutes (17.9%) and Actinobacteria (7.4%). High percentages of relative abundance for Wolbachia (30%-83%) in Lu. gomezi, Ev. dubitans, Mi. micropyga, Br. hamata, and Cx. nigripalpus were found. ASVs assigned as Microsporidia were found in greater abundance in Pi. pia (23%) and Cx. nigripalpus (11%). An important finding is the detection of Rickettsia in Pi. pia (58,8%) and Bartonella sp. in Cx. nigripalpus.<br><br>CONCLUSIONS/SIGNIFICANCE: We found that Wolbachia infection significantly decreased the alpha diversity and negatively impacts the number of taxa on sand flies and Culex nigripalpus. The Principal Coordinate Analysis (PCoA) is consistent, which showed statistically significant differences (PERMANOVA, F = 2.4744; R2 = 0.18363; p-value = 0.007) between the microbiota of sand flies and mosquitoes depending on its origin, host and possibly for the abundance of some endosymbionts (Wolbachia, Rickettsia).}, }
@article {pmid34925404, year = {2021}, author = {Suzuki, S and Kawachi, M and Tsukakoshi, C and Nakamura, A and Hagino, K and Inouye, I and Ishida, KI}, title = {Unstable Relationship Between Braarudosphaera bigelowii (= Chrysochromulina parkeae) and Its Nitrogen-Fixing Endosymbiont.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {749895}, pmid = {34925404}, issn = {1664-462X}, abstract = {Marine phytoplankton are major primary producers, and their growth is primarily limited by nitrogen in the oligotrophic ocean environment. The haptophyte Braarudosphaera bigelowii possesses a cyanobacterial endosymbiont (UCYN-A), which plays a major role in nitrogen fixation in the ocean. However, host-symbiont interactions are poorly understood because B. bigelowii was unculturable. In this study, we sequenced the complete genome of the B. bigelowii endosymbiont and showed that it was highly reductive and closely related to UCYN-A2 (an ecotype of UCYN-A). We succeeded in establishing B. bigelowii strains and performed microscopic observations. The detailed observations showed that the cyanobacterial endosymbiont was surrounded by a single host derived membrane and divided synchronously with the host cell division. The transcriptome of B. bigelowii revealed that B. bigelowii lacked the expression of many essential genes associated with the uptake of most nitrogen compounds, except ammonia. During cultivation, some of the strains completely lost the endosymbiont. Moreover, we did not find any evidence of endosymbiotic gene transfer from the endosymbiont to the host. These findings illustrate an unstable morphological, metabolic, and genetic relationship between B. bigelowii and its endosymbiont.}, }
@article {pmid34919808, year = {2022}, author = {Hague, MTJ and Shropshire, JD and Caldwell, CN and Statz, JP and Stanek, KA and Conner, WR and Cooper, BS}, title = {Temperature effects on cellular host-microbe interactions explain continent-wide endosymbiont prevalence.}, journal = {Current biology : CB}, volume = {32}, number = {4}, pages = {878-888.e8}, pmid = {34919808}, issn = {1879-0445}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Drosophila melanogaster/genetics ; Host Microbial Interactions ; Prevalence ; Temperature ; *Wolbachia/genetics ; }, abstract = {Endosymbioses influence host physiology, reproduction, and fitness, but these relationships require efficient microbe transmission between host generations to persist. Maternally transmitted Wolbachia are the most common known endosymbionts,[1] but their frequencies vary widely within and among host populations for unknown reasons.[2][,][3] Here, we integrate genomic, cellular, and phenotypic analyses with mathematical models to provide an unexpectedly simple explanation for global wMel Wolbachia prevalence in Drosophila melanogaster. Cooling temperatures decrease wMel cellular abundance at a key stage of host oogenesis, producing temperature-dependent variation in maternal transmission that plausibly explains latitudinal clines of wMel frequencies on multiple continents. wMel sampled from a temperate climate targets the germline more efficiently in the cold than a recently differentiated tropical variant (∼2,200 years ago), indicative of rapid wMel adaptation to climate. Genomic analyses identify a very narrow list of wMel alleles-most notably, a derived stop codon in the major Wolbachia surface protein WspB-that underlie thermal sensitivity of cellular Wolbachia abundance and covary with temperature globally. Decoupling temperate wMel and host genomes further reduces transmission in the cold, a pattern that is characteristic of host-microbe co-adaptation to a temperate climate. Complex interactions among Wolbachia, hosts, and the environment (GxGxE) mediate wMel cellular abundance and maternal transmission, implicating temperature as a key determinant of Wolbachia spread and equilibrium frequencies, in conjunction with Wolbachia effects on host fitness and reproduction.[4][,][5] Our results motivate the strategic use of locally selected wMel variants for Wolbachia-based biocontrol efforts, which protect millions of individuals from arboviruses that cause human disease.[6].}, }
@article {pmid34906073, year = {2021}, author = {Cotroneo, CE and Gormley, IC and Shields, DC and Salter-Townshend, M}, title = {Computational modelling of chromosomally clustering protein domains in bacteria.}, journal = {BMC bioinformatics}, volume = {22}, number = {1}, pages = {593}, pmid = {34906073}, issn = {1471-2105}, mesh = {Archaea/genetics ; Bacteria/genetics ; Cluster Analysis ; Computer Simulation ; Evolution, Molecular ; *Genome, Archaeal ; *Genome, Bacterial ; Phylogeny ; Protein Domains ; }, abstract = {BACKGROUND: In bacteria, genes with related functions-such as those involved in the metabolism of the same compound or in infection processes-are often physically close on the genome and form groups called clusters. The enrichment of such clusters over various distantly related bacteria can be used to predict the roles of genes of unknown function that cluster with characterised genes. There is no obvious rule to define a cluster, given their variability in size and intergenic distances, and the definition of what comprises a "gene", since genes can gain and lose domains over time. Protein domains can cluster within a gene, or in adjacent genes of related function, and in both cases these are chromosomally clustered. Here, we model the distances between pairs of protein domain coding regions across a wide range of bacteria and archaea via a probabilistic two component mixture model, without imposing arbitrary thresholds in terms of gene numbers or distances.<br><br>RESULTS: We trained our model using matched gene ontology terms to label functionally related pairs and assess the stability of the parameters of the model across 14,178 archaeal and bacterial strains. We found that the parameters of our mixture model are remarkably stable across bacteria and archaea, except for endosymbionts and obligate intracellular pathogens. Obligate pathogens have smaller genomes, and although they vary, on average do not show noticeably different clustering distances; the main difference in the parameter estimates is that a far greater proportion of the genes sharing ontology terms are clustered. This may reflect that these genomes are enriched for complexes encoded by clustered core housekeeping genes, as a proportion of the total genes. Given the overall stability of the parameter estimates, we then used the mean parameter estimates across the entire dataset to investigate which gene ontology terms are most frequently associated with clustered genes.<br><br>CONCLUSIONS: Given the stability of the mixture model across species, it may be used to predict bacterial gene clusters that are shared across multiple species, in addition to giving insights into the evolutionary pressures on the chromosomal locations of genes in different species.}, }
@article {pmid34903056, year = {2021}, author = {Shropshire, JD and Hamant, E and Cooper, BS}, title = {Male Age and Wolbachia Dynamics: Investigating How Fast and Why Bacterial Densities and Cytoplasmic Incompatibility Strengths Vary.}, journal = {mBio}, volume = {12}, number = {6}, pages = {e0299821}, pmid = {34903056}, issn = {2150-7511}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Cytoplasm/genetics/*microbiology ; Drosophila/genetics/immunology/*microbiology/physiology ; Drosophila melanogaster ; Female ; Male ; Species Specificity ; Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Endosymbionts can influence host reproduction and fitness to favor their maternal transmission. For example, endosymbiotic Wolbachia bacteria often cause cytoplasmic incompatibility (CI) that kills uninfected embryos fertilized by Wolbachia-modified sperm. Infected females can rescue CI, providing them a relative fitness advantage. Wolbachia-induced CI strength varies widely and tends to decrease as host males age. Since strong CI drives Wolbachia to high equilibrium frequencies, understanding how fast and why CI strength declines with male age is crucial to explaining age-dependent CI's influence on Wolbachia prevalence. Here, we investigate if Wolbachia densities and/or CI gene (cif) expression covary with CI-strength variation and explore covariates of age-dependent Wolbachia-density variation in two classic CI systems. wRi CI strength decreases slowly with Drosophila simulans male age (6%/day), but wMel CI strength decreases very rapidly (19%/day), yielding statistically insignificant CI after only 3 days of Drosophila melanogaster adult emergence. Wolbachia densities and cif expression in testes decrease as wRi-infected males age, but both surprisingly increase as wMel-infected males age, and CI strength declines. We then tested if phage lysis, Octomom copy number (which impacts wMel density), or host immune expression covary with age-dependent wMel densities. Only host immune expression correlated with density. Together, our results identify how fast CI strength declines with male age in two model systems and reveal unique relationships between male age, Wolbachia densities, cif expression, and host immunity. We discuss new hypotheses about the basis of age-dependent CI strength and its contributions to Wolbachia prevalence. IMPORTANCEWolbachia bacteria are the most common animal-associated endosymbionts due in large part to their manipulation of host reproduction. Many Wolbachia cause cytoplasmic incompatibility (CI) that kills uninfected host eggs. Infected eggs are protected from CI, favoring Wolbachia spread in natural systems and in transinfected mosquito populations where vector-control groups use strong CI to maintain pathogen-blocking Wolbachia at high frequencies for biocontrol of arboviruses. CI strength varies considerably in nature and declines as males age for unknown reasons. Here, we determine that CI strength weakens at different rates with age in two model symbioses. Wolbachia density and CI gene expression covary with wRi-induced CI strength in Drosophila simulans, but neither explain rapidly declining wMel-induced CI in aging D. melanogaster males. Patterns of host immune gene expression suggest a candidate mechanism behind age-dependent wMel densities. These findings inform how age-dependent CI may contribute to Wolbachia prevalence in natural systems and potentially in transinfected systems.}, }
@article {pmid34893862, year = {2022}, author = {de Oliveira, AL and Mitchell, J and Girguis, P and Bright, M}, title = {Novel Insights on Obligate Symbiont Lifestyle and Adaptation to Chemosynthetic Environment as Revealed by the Giant Tubeworm Genome.}, journal = {Molecular biology and evolution}, volume = {39}, number = {1}, pages = {}, pmid = {34893862}, issn = {1537-1719}, mesh = {Acclimatization ; Animals ; *Gammaproteobacteria/genetics ; *Polychaeta/genetics/metabolism ; Symbiosis/genetics ; }, abstract = {The mutualism between the giant tubeworm Riftia pachyptila and its endosymbiont Candidatus Endoriftia persephone has been extensively researched over the past 40 years. However, the lack of the host whole-genome information has impeded the full comprehension of the genotype/phenotype interface in Riftia. Here, we described the high-quality draft genome of Riftia, its complete mitogenome, and tissue-specific transcriptomic data. The Riftia genome presents signs of reductive evolution, with gene family contractions exceeding expansions. Expanded gene families are related to sulfur metabolism, detoxification, antioxidative stress, oxygen transport, immune system, and lysosomal digestion, reflecting evolutionary adaptations to the vent environment and endosymbiosis. Despite the derived body plan, the developmental gene repertoire in the gutless tubeworm is extremely conserved with the presence of a near intact and complete Hox cluster. Gene expression analyses establish that the trophosome is a multifunctional organ marked by intracellular digestion of endosymbionts, storage of excretory products, and hematopoietic functions. Overall, the plume and gonad tissues both in contact to the environment harbor highly expressed genes involved with cell cycle, programed cell death, and immunity indicating a high cell turnover and defense mechanisms against pathogens. We posit that the innate immune system plays a more prominent role into the establishment of the symbiosis during the infection in the larval stage, rather than maintaining the symbiostasis in the trophosome. This genome bridges four decades of physiological research in Riftia, whereas it simultaneously provides new insights into the development, whole organism functions, and evolution in the giant tubeworm.}, }
@article {pmid34889195, year = {2021}, author = {Gürelli, G and Mohamed, ARA}, title = {Comparative Study of Rumen Ciliate Fauna of Goat and Sheep in Libya.}, journal = {Turkiye parazitolojii dergisi}, volume = {45}, number = {4}, pages = {274-279}, doi = {10.4274/tpd.galenos.2021.39974}, pmid = {34889195}, issn = {2146-3077}, mesh = {Animals ; *Ciliophora ; *Goats ; Laboratories ; Libya/epidemiology ; Rumen ; Sheep ; }, abstract = {OBJECTIVE: This study aims to provide comparative information on the rumen ciliate fauna of goat (Capra aegagrus hircus) and sheep (Ovis aries) living in Zawiya, Libya.<br><br>METHODS: We obtained rumen samples from 16 goats and 17 sheep after the slaughter in Zawiya, Libya between June and August 2016. We immediately fixed the well-mixed samples with an equal volume of 18.5% formalin. We filtered and stained the samples in the laboratory with methyl green formalin saline solution to determine the nuclei and added 2% Lugol's iodine solution to visualize the skeletal plates.<br><br>RESULTS: We found that the mean number (&#xb1; standard deviation) of ciliates in the rumen contents from goats and sheep was 70.9&#xb1;61.6&#xd7;10[4] cells mL[-1] (minimum-maximum value, 4.0-187.0&#xd7;10[4] cells mL[-1]) and 96.3&#xb1;49.3&#xd7;10[4] cells mL[-1] (minimum-maximum value, 19.5-235.0&#xd7;10[4] cells mL[-1]), respectively. Results also showed that the total number of species per goat and sheep was 1-17 (mean, 8.2&#xb1;4.7) and 1-13 (mean, 7.9&#xb1;3.8), respectively. We identified 10 genera, 19 species, and 11 morphotypes in goats and 9 genera, 16 species, and 13 morphotypes in sheep. Additionally, we found that Entodinium simulans prevalence in all goats and sheep was 100%. On the other hand, we observed Hsiungia triciliata and Ostracodinium gracile in only one goat (6.3% prevalence) and Polyplastron multivesiculatum in only one sheep (5.9% prevalence). Overall, the ruminal ciliate fauna of goat and sheep in Libya comprised Entodinium species (mean for goats, 85.9%; mean for sheep, 83.5%).<br><br>CONCLUSION: This study recorded Hsiungia triciliata as a new endosymbiont in goats. To our knowledge, this study is the first to report all of the species detected in goats from Libya. Similarly, this is the first to detect Diplodinium anisacanthum, Entodinium bursa, E. ellipsoideum, E. longinucleatum, E. simulans, Isotricha prostoma, Ophryoscolex caudatus, Ostracodinium gracile, and Polyplastron multivesiculatum in sheep from Libya.}, }
@article {pmid34881320, year = {2021}, author = {Takhampunya, R and Sakolvaree, J and Chanarat, N and Youngdech, N and Phonjatturas, K and Promsathaporn, S and Tippayachai, B and Tachavarong, W and Srinoppawan, K and Poole-Smith, BK and McCardle, PW and Chaorattanakawee, S}, title = {The Bacterial Community in Questing Ticks From Khao Yai National Park in Thailand.}, journal = {Frontiers in veterinary science}, volume = {8}, number = {}, pages = {764763}, pmid = {34881320}, issn = {2297-1769}, abstract = {Ticks are known vectors for a variety of pathogens including bacteria, viruses, fungi, and parasites. In this study, bacterial communities were investigated in active life stages of three tick genera (Haemaphysalis, Dermacentor, and Amblyomma) collected from Khao Yai National Park in Thailand. Four hundred and thirty-three questing ticks were selected for pathogen detection individually using real-time PCR assays, and 58 of these were subjected to further metagenomics analysis. A total of 62 ticks were found to be infected with pathogenic bacteria, for a 14.3% prevalence rate, with Amblyomma spp. exhibiting the highest infection rate (20.5%), followed by Haemaphysalis spp. (14.5%) and Dermacentor spp. (8.6%). Rickettsia spp. were the most prevalent bacteria (7.9%) found, followed by Ehrlichia spp. (3.2%), and Anaplasma spp. and Borrelia spp. each with a similar prevalence of 1.6%. Co-infection between pathogenic bacteria was only detected in three Haemaphysalis females, and all co-infections were between Rickettsia spp. and Anaplasmataceae (Ehrlichia spp. or Anaplasma spp.), accounting for 4.6% of infected ticks or 0.7% of all examined questing ticks. The prevalence of the Coxiella-like endosymbiont was also investigated. Of ticks tested, 65.8% were positive for the Coxiella-like endosymbiont, with the highest infection rate in nymphs (86.7%), followed by females (83.4%). Among tick genera, Haemaphysalis exhibited the highest prevalence of infection with the Coxiella-like endosymbiont. Ticks harboring the Coxiella-like endosymbiont were more likely to be infected with Ehrlichia spp. or Rickettsia spp. than those without, with statistical significance for Ehrlichia spp. infection in particular (p-values = 0.003 and 0.917 for Ehrlichia spp. and Rickettsia spp., respectively). Profiling the bacterial community in ticks using metagenomics revealed distinct, predominant bacterial taxa in tick genera. Alpha and beta diversities analyses showed that the bacterial community diversity and composition in Haemaphysalis spp. was significantly different from Amblyomma spp. However, when examining bacterial diversity among tick life stages (larva, nymph, and adult) in Haemaphysalis spp., no significant difference among life stages was detected. These results provide valuable information on the bacterial community composition and co-infection rates in questing ticks in Thailand, with implications for animal and human health.}, }
@article {pmid34878815, year = {2022}, author = {Horn, CJ and Yoon, T and Mierzejewski, MK and Luong, LT}, title = {Endosymbiotic Male-Killing Spiroplasma Affects the Physiological and Behavioral Ecology of Macrocheles-Drosophila Interactions.}, journal = {Applied and environmental microbiology}, volume = {88}, number = {3}, pages = {e0197221}, pmid = {34878815}, issn = {1098-5336}, mesh = {Animals ; *Drosophila ; Host-Parasite Interactions ; Male ; Phylogeny ; *Spiroplasma/physiology ; Symbiosis ; }, abstract = {While many arthropod endosymbionts are vertically transmitted, phylogenetic studies reveal repeated introductions of hemolymph-dwelling Spiroplasma into Drosophila. Introductions are often attributed to horizontal transmission via ectoparasite vectors. Here, we test if mites (Macrocheles subbadius) prefer to infect Spiroplasma poulsonii MSRO (Melanogaster sex ratio organism)-infected flies and if MSRO infection impairs fly resistance against secondary mite attack. First, we tested if mites prefer MSRO[+] or MSRO[-] flies using pairwise choice tests across fly ages. We then tested whether mite preferences are explained by changes in fly physiology, specifically increased metabolic rate (measured as CO2 production). We hypothesize that this preference is due in part to MSRO[+] flies expressing higher metabolic rates. However, our results showed mite preference depended on an interaction between fly age and MSRO status: mites avoided 14-day-old MSRO[+] flies relative to MSRO[-] flies (31% infection) but preferred MSRO[+] flies (64% infection) among 26-day-old flies. Using flowthrough respirometry, we found 14-day-old MSRO[+] flies had higher CO2 emissions than MSRO[-] flies (32% greater), whereas at 26 days old the CO2 production among MSRO[+] flies was 20% lower than that of MSRO[-] flies. Thus, mite preferences for high-metabolic-rate hosts did not explain the infection biases in this study. To assess changes in susceptibility to infection, we measured fly endurance using geotaxis assays. Older flies had lower endurance consistent with fly senescence, and this effect was magnified among MSRO[+] flies. Given the biological importance of male-killing Spiroplasma, potential changes in the interactions of hosts and potential vectors could impact the ecology and evolution of host species. IMPORTANCE Male-killing endosymbionts are transmitted from mother to daughter and kill male offspring. Despite these major ecological effects, how these endosymbionts colonize new host species is not always clear. Mites are sometimes hypothesized to transfer these bacteria between hosts/host species. Here, we test if (i) mites prefer to infect flies that harbor Spiroplasma poulisoni MSRO and (ii) flies infected with MSRO are less able to resist mite infection. Our results show that flies infected with MSRO have weaker anti-mite resistance, but the mite preference/aversion for MSRO[+] flies varied with fly age. Given the fitness and population impacts of male-killing Spiroplasma, changes in fly-mite interactions have implications for the ecology and evolution of these symbioses.}, }
@article {pmid34878113, year = {2022}, author = {Byrne, S and Schughart, M and Carolan, JC and Gaffney, M and Thorpe, P and Malloch, G and Wilkinson, T and McNamara, L}, title = {Genome sequence of the English grain aphid, Sitobion avenae and its endosymbiont Buchnera aphidicola.}, journal = {G3 (Bethesda, Md.)}, volume = {12}, number = {3}, pages = {}, pmid = {34878113}, issn = {2160-1836}, support = {/WT_/Wellcome Trust/United Kingdom ; 05621/Z/14/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Aphids/genetics ; *Buchnera/genetics ; Genome ; Sequence Analysis, DNA ; Triticum/genetics ; }, abstract = {The English grain aphid, Sitobion avenae, is a major agricultural pest of wheat, barley and oats, and one of the principal vectors of barley yellow dwarf virus leading to significant reductions in grain yield, annually. Emerging resistance to and increasing regulation of insecticides has resulted in limited options for their control. Using PacBio HiFi data, we have produced a high-quality draft assembly of the S. avenae genome; generating a primary assembly with a total assembly size of 475.7 Mb, and an alternate assembly with a total assembly size of 430.8 Mb. Our primary assembly was highly contiguous with only 326 contigs and a contig N50 of 15.95 Mb. Assembly completeness was estimated at 97.7% using BUSCO analysis and 31,007 and 29,037 protein-coding genes were predicted from the primary and alternate assemblies, respectively. This assembly, which is to our knowledge the first for an insecticide resistant clonal lineage of English grain aphid, will provide novel insight into the molecular and mechanistic determinants of resistance and will facilitate future research into mechanisms of viral transmission and aphid behavior.}, }
@article {pmid34869220, year = {2021}, author = {Ding, L and Zhang, SD and Haidar, AK and Bajimaya, M and Guo, Y and Larsen, TO and Gram, L}, title = {Polycyclic Tetramate Macrolactams-A Group of Natural Bioactive Metallophores.}, journal = {Frontiers in chemistry}, volume = {9}, number = {}, pages = {772858}, pmid = {34869220}, issn = {2296-2646}, abstract = {New infectious diseases and increase in drug-resistant microbial pathogens emphasize the need for antibiotics with novel mode-of-action. Tetramates represented by fungi-derived tenuazonic acid and bacterial polycyclic tetramate macrolactams (PTMs) are an important family of natural products with a broad spectrum of antimicrobial activities. Despite their potential application as new antibiotics, it remains unknown how PTMs function. In this study, genomic mining revealed that PTM biosynthetic gene clusters (BGCs) are widespread in both Gram-positive and Gram-negative bacteria, and we investigated a sponge endosymbiont Actinoalloteichus hymeniacidonis harboring a potential PTM-BGC. Xanthobaccin A that previously has only been isolated from a Gram-negative bacterium was obtained after a scale-up fermentation, isolation, and structure elucidation through mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy. Xanthobaccin A as well as two previously reported tetramates, equisetin and ikarugamycin, exhibited antibacterial activities against Bacillus subtilis. In addition, these three tetramates were for the first time to be confirmed as metallophores and the stoichiometry of the complexes were shown to be Fe(III)(equisetin)3/Fe(III)(equisetin)2 and Fe(III)(ikarugamycin)2, respectively. Meanwhile, we found that all three tetramates could reduce ferric into ferrous iron, which triggers the Fenton chemistry reaction. Their antibacterial activity was reduced by adding the radical scavenger, vitamin C. Altogether, our work demonstrates that equisetin and PTMs can act as metallophores and their antimicrobial mechanism is possibly mediated through Fenton chemistry.}, }
@article {pmid34864906, year = {2022}, author = {Cooper, WR and Horton, DR and Swisher-Grimm, K and Krey, K and Wildung, MR}, title = {Bacterial Endosymbionts of Bactericera maculipennis and Three Mitochondrial Haplotypes of B. cockerelli (Hemiptera: Psylloidea: Triozidae).}, journal = {Environmental entomology}, volume = {51}, number = {1}, pages = {94-107}, doi = {10.1093/ee/nvab133}, pmid = {34864906}, issn = {1938-2936}, mesh = {Animals ; Bacteria/genetics ; Haplotypes ; *Hemiptera/microbiology ; Plant Diseases/microbiology ; *Rhizobiaceae ; *Solanum tuberosum/microbiology ; }, abstract = {Insects harbor bacterial endosymbionts that provide their hosts with nutritional benefit or with protection against natural enemies, plant defenses, insecticides, or abiotic stresses. We used directed sequencing of 16S rDNA to identify and compare endosymbionts of Bactericera maculipennis (Crawford) and the western, central, and northwestern haplotypes of B. cockerelli (Šulc) (Hemiptera: Psylloidea: Triozidae). Both species are native to North America, are known to harbor the plant pathogen 'Candidatus Liberibacter solanacearum' and develop on shared host plants within the Convolvulaceae. The Old-World species Heterotrioza chenopodii (Reuter) (Psylloidea: Triozidae), now found in North America, was included as an outgroup. 16S sequencing confirmed that both Bactericera species harbor 'Candidatus Liberibacter solanacearum' and revealed that both species harbor unique strains of Wolbachia and Sodalis. However, the presence of Wolbachia and Sodalis varied among haplotypes of B. cockerelli. The central and western haplotypes harbored the same strains of Wolbachia, which was confirmed by Sanger sequencing of the wsp and ftsZ genes. Wolbachia was also detected in very low abundance from the northwestern haplotype by high-throughput sequencing of 16S but was not detected from this haplotype by PCR screening. The northwestern and central haplotypes also harbored Sodalis, which was not detected in the western haplotype. Heterotrioza chenopodii harbored an entirely different community of potential endosymbionts compared with the Bactericera spp. that included Rickettsia and an unidentified bacterium in the Enterobacteriaceae. Results of this study provide a foundation for further research on the interactions between psyllids and their bacterial endosymbionts.}, }
@article {pmid34863611, year = {2022}, author = {Nobs, SJ and MacLeod, FI and Wong, HL and Burns, BP}, title = {Eukarya the chimera: eukaryotes, a secondary innovation of the two domains of life?.}, journal = {Trends in microbiology}, volume = {30}, number = {5}, pages = {421-431}, doi = {10.1016/j.tim.2021.11.003}, pmid = {34863611}, issn = {1878-4380}, mesh = {Archaea/genetics ; Bacteria/genetics ; *Biological Evolution ; *Eukaryota/genetics ; Eukaryotic Cells ; Phylogeny ; }, abstract = {One of the most significant events in the evolution of life is the origin of the eukaryotic cell, an increase in cellular complexity that occurred approximately 2 billion years ago. Ground-breaking research has centered around unraveling the characteristics of the Last Eukaryotic Common Ancestor (LECA) and the nuanced archaeal and bacterial contributions in eukaryogenesis, resulting in fundamental changes in our understanding of the Tree of Life. The archaeal and bacterial roles are covered by theories of endosymbiogenesis wherein an ancestral host archaeon and a bacterial endosymbiont merged to create a new complex cell type - Eukarya - and its mitochondrion. Eukarya is often regarded as a unique and distinct domain due to complex innovations not found in archaea or bacteria, despite housing a chimeric genome containing genes of both archaeal and bacterial origin. However, the discovery of complex cell machineries in recently described Asgard archaeal lineages, and the growing support for diverse bacterial gene transfers prior to and during the time of LECA, is redefining our understanding of eukaryogenesis. Indeed, the uniqueness of Eukarya, as a domain, is challenged. It is likely that many microbial syntrophies, encompassing a 'microbial village', were required to 'raise' a eukaryote during the process of eukaryogenesis.}, }
@article {pmid34861071, year = {2022}, author = {Armstrong, EE and Perez-Lamarque, B and Bi, K and Chen, C and Becking, LE and Lim, JY and Linderoth, T and Krehenwinkel, H and Gillespie, RG}, title = {A holobiont view of island biogeography: Unravelling patterns driving the nascent diversification of a Hawaiian spider and its microbial associates.}, journal = {Molecular ecology}, volume = {31}, number = {4}, pages = {1299-1316}, doi = {10.1111/mec.16301}, pmid = {34861071}, issn = {1365-294X}, mesh = {Animals ; Geography ; Hawaii ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Spiders/genetics ; }, abstract = {The diversification of a host lineage can be influenced by both the external environment and its assemblage of microbes. Here, we use a young lineage of spiders, distributed along a chronologically arranged series of volcanic mountains, to investigate how their associated microbial communities have changed as the spiders colonized new locations. Using the stick spider Ariamnes waikula (Araneae, Theridiidae) on the island of Hawai'i, and outgroup taxa on older islands, we tested whether each component of the "holobiont" (spider hosts, intracellular endosymbionts and gut microbial communities) showed correlated signatures of diversity due to sequential colonization from older to younger volcanoes. To investigate this, we generated ddRAD data for the host spiders and 16S rRNA gene amplicon data from their microbiota. We expected sequential colonizations to result in a (phylo)genetic structuring of the host spiders and in a diversity gradient in microbial communities. The results showed that the host A. waikula is indeed structured by geographical isolation, suggesting sequential colonization from older to younger volcanoes. Similarly, the endosymbiont communities were markedly different between Ariamnes species on different islands, but more homogeneous among A. waikula populations on the island of Hawai'i. Conversely, the gut microbiota, which we suspect is generally environmentally derived, was largely conserved across all populations and species. Our results show that different components of the holobiont respond in distinct ways to the dynamic environment of the volcanic archipelago. This highlights the necessity of understanding the interplay between different components of the holobiont, to properly characterize its evolution.}, }
@article {pmid34849818, year = {2021}, author = {Bauer DuMont, VL and White, SL and Zinshteyn, D and Aquadro, CF}, title = {Molecular population genetics of Sex-lethal (Sxl) in the Drosophila melanogaster species group: a locus that genetically interacts with Wolbachia pipientis in Drosophila melanogaster.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {8}, pages = {}, pmid = {34849818}, issn = {2160-1836}, support = {R01 GM095793/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Drosophila Proteins/genetics/metabolism ; Drosophila melanogaster/genetics/metabolism ; Female ; Genetics, Population ; RNA-Binding Proteins ; *Wolbachia/metabolism ; }, abstract = {Sex-lethal (Sxl) is the sex determination switch in Drosophila, and also plays a critical role in germ-line stem cell daughter differentiation in Drosophila melanogaster. Three female-sterile alleles at Sxl in D. melanogaster were previously shown to genetically interact to varying degrees with the maternally inherited endosymbiont Wolbachia pipientis. Given this genetic interaction and W. pipientis' ability to manipulate reproduction in Drosophila, we carried out a careful study of both the population genetics (within four Drosophila species) and molecular evolutionary analysis (across 20 Drosophila species) of Sxl. Consistent with earlier studies, we find that selective constraint has played a prominent role in Sxl's molecular evolution within Drosophila, but we also observe patterns that suggest both episodic bursts of protein evolution and recent positive selection at Sxl. The episodic nature of Sxl's protein evolution is discussed in light of its genetic interaction with W. pipientis.}, }
@article {pmid34846757, year = {2022}, author = {Kuo, CC and Lee, PL and Wang, HC}, title = {Molecular identification of Rickettsia spp. in chigger mites in Taiwan.}, journal = {Medical and veterinary entomology}, volume = {36}, number = {2}, pages = {223-229}, doi = {10.1111/mve.12560}, pmid = {34846757}, issn = {1365-2915}, mesh = {Animals ; *Mite Infestations/veterinary ; *Rickettsia/genetics ; *Rodent Diseases ; Rodentia ; *Scrub Typhus/microbiology/veterinary ; *Siphonaptera/microbiology ; Taiwan ; *Ticks ; *Trombiculidae/microbiology ; }, abstract = {The genus Rickettsia is the causative agent of several rickettsial diseases that are primarily transmitted by hard ticks. The occurrence of Rickettsia in chigger mites, which are vectors of scrub typhus in the western Pacific region, has been infrequently investigated. We identified Rickettsia spp. in chiggers collected from small mammals in six counties of Taiwan. Moreover, by capitalising on parallel Rickettsia detections on small mammals and their infested ticks and fleas, we were able to identify Rickettsia spp. that suggested more intimate associations with chigger mites. Rickettsia detection rates in 318 pools of chiggers were 21.7% and 22.3% when based on the ompB and gltA gene, respectively. Overall, we identified six (based on the ompB gene) and eight (gltA gene) Rickettsia species. Approximately half of the sequenced species were most similar to Rickettsia sp. clone MB74-1 (ompB gene) and Rickettsia sp. TwKM02 (gltA gene). Furthermore, both species were either infrequently or never identified in small mammals, ticks and fleas, which suggests that chigger mites might be the primary host of both rickettsiae. Whether both species are pathogenic to humans remains to be studied. They may also be microbial endosymbionts of chigger mites, with their potential effects on the pathogenicity of the aetiologic agent of scrub typhus deserving further investigations.}, }
@article {pmid34845838, year = {2022}, author = {Watanabe, K and Motonaga, A and Tachibana, M and Shimizu, T and Watarai, M}, title = {Francisella novicida can utilize Paramecium bursaria as its potential host.}, journal = {Environmental microbiology reports}, volume = {14}, number = {1}, pages = {50-59}, doi = {10.1111/1758-2229.13029}, pmid = {34845838}, issn = {1758-2229}, mesh = {*Chlorella ; *Francisella ; *Paramecium/microbiology ; *Tularemia/microbiology ; }, abstract = {Francisella novicida is a facultative intracellular pathogen and the causative agent of tularemia. Although cases of infection caused by exposure to contaminated water have been reported, its natural host and ecology in the environment remain unclear. In this study, we investigated in vitro the possibility that Paramecium bursaria may be a useful tool as a protist host model of F. novicida. Experimental infection with F. novicida resulted in a stable intracellular relationship within P. bursaria. This symbiotic intracellular relationship was not observed in experimental infections with other Francisella species and Legionella pneumophila. We found that F. novicida showed similar behaviour to that of the eukaryotic endosymbiont of P. bursaria, the green algae Chlorella, in the internalization process. In addition, stable intracellular localization of F. novicida was possible only when Chlorella was not present. Although we investigated the type VI secretion system of F. novicida as a candidate for the bacterial factor, we found that it was not involved in the establishment of an intracellular relationship with P. bursaria. These results suggested that P. bursaria is potentially a protist host model for F. novicida and may be a useful tool for understanding the relationship between protist hosts and their symbionts.}, }
@article {pmid34843992, year = {2022}, author = {Manoj, RRS and Latrofa, MS and Bezerra-Santos, MA and Sgroi, G and Samarelli, R and Mendoza-Roldan, JA and Otranto, D}, title = {Molecular detection and characterization of the endosymbiont Wolbachia in the European hedgehog flea, Archaeopsylla erinacei.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {97}, number = {}, pages = {105161}, doi = {10.1016/j.meegid.2021.105161}, pmid = {34843992}, issn = {1567-7257}, mesh = {Animals ; Bacterial Outer Membrane Proteins/analysis ; Female ; Italy ; Male ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Siphonaptera/*microbiology ; *Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia, the endosymbiont of arthropods and onchocercid nematodes is present in many medically important insect species, being also considered for the indirect control of parasitic ones. Archaeopsylla erinacei is a flea species infesting hedgehogs acting as vector of Rickettsia felis, Bartonella henselae, and Rickettsia helvetica, thus having public health relevance. The Wolbachia surface protein (wsp) and 16S rRNA genes were used to determine the presence, prevalence and molecular typing of Wolbachia in this flea species collected in two regions of southern Italy. Of the 45 fleas tested (n = 16 males, 35.6%; n = 29 females, 64.4%), 43 (95.6%; 95% CI: 84.8-99.2) scored positive for Wolbachia, of which 15 (33.3%) and 28 (62.2%) were males and females, respectively. The sex-wise prevalence of this endosymbiont was almost equal in both sexes (males 93.8%; 95% CI: 69.5-99.7; females 96.7%; 95% CI: 83.1-99.8). Single locus sequence analysis (SLST) of Wolbachia revealed two sequence types for 16S rRNA gene, named as wAr_15227 and wAr_15234, which came from two different areas, equally distributed in male and female fleas, whilst only one sequence type was identified for wsp gene. The phylogenetic analysis placed the two 16S rRNA sequence types in paraphyletic clades belonging to the supergroup A and B, respectively. Whilst, the tree of wsp gene clustered the corresponding sequence in the same clade including those of Wolbachia supergroup A. In MLST analyses, both Wolbachia sequence types clustered in a monophyletic clade with Drosophila nikananu (wNik) and Drosophila sturtevanti (wStv) from supergroup A. ClonalFrame analysis revealed a recombination event in the wAr_15234 strain which came from Apulia region. Scientific knowledge of the presence/prevalence of Wolbachia among medically important fleas, may contribute to develop an alternative biological method for the vector control.}, }
@article {pmid34843507, year = {2021}, author = {Singh, I and Kaur, R and Kumar, A and Singh, S and Sharma, A}, title = {Differential expression of gut protein genes and population density of Arsenophonus contributes to sex-biased transmission of Bemisia tabaci vectored Cotton leaf curl virus.}, journal = {PloS one}, volume = {16}, number = {11}, pages = {e0259374}, pmid = {34843507}, issn = {1932-6203}, mesh = {Animals ; Begomovirus/growth &amp; development/*physiology ; Cyclophilins/antagonists &amp; inhibitors/genetics/metabolism ; Digestive System/*metabolism ; Female ; Gammaproteobacteria/*growth &amp; development/isolation &amp; purification/physiology ; Gene Expression Regulation ; Gene Silencing ; HSP40 Heat-Shock Proteins/antagonists &amp; inhibitors/genetics/metabolism ; Haplotypes ; Hemiptera/*virology ; Insect Proteins/antagonists &amp; inhibitors/genetics/*metabolism ; Insect Vectors/virology ; Male ; Plant Diseases/virology ; RNA, Double-Stranded/metabolism ; Sex Factors ; Symbiosis ; Viral Load ; }, abstract = {Whitefly, Bemisia tabaci (Gennadius) is an important pest of cotton causing direct damage as sap feeder and vector of Cotton leaf curl virus (CLCuV). Previous few studies suggest that female whiteflies are more efficient vector of begomovirusthan males, however the sex-biased transmission efficiency is still not clearly understood. Present studies with B. tabaci AsiaII-1 haplotype showed higher virus transmission efficiency of females compared to males. This variable begomovirus transmission efficiency has been related to previously identifiedkey factors associated with B. tabaci. The higher density of endosymbiont Arsenophonus and variable expression of some midgut proteins genes i.e. Cyclophilin, Knottin, Hsp40, Hsp70 may be possibly imparting higher vector competency to the females compared to males. The present studies suggest low abundance of Arsenophonus spp. as well as lower expressionof Cyclophilin genein males as compared to females. This is further supplemented by overexpression of Knottin, Hsp40, and Hsp70 genes in males compared to females and thus collectively all these factors might be playing a key role in low virus transmission efficiency of males. The relative density of Arsenophonus spp. and expression of midgut proteins genes in male and female whitefly first time enriches our understanding about sex-biased transmission efficiency of begomovirus.}, }
@article {pmid34838119, year = {2021}, author = {Hamlili, FZ and Bérenger, JM and Diarra, AZ and Parola, P}, title = {Molecular and MALDI-TOF MS identification of swallow bugs Cimex hirundinis (Heteroptera: Cimicidae) and endosymbionts in France.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {587}, pmid = {34838119}, issn = {1756-3305}, mesh = {Animals ; *Bedbugs/classification/microbiology ; Birds ; France ; Humans ; Pathology, Molecular ; Phylogeny ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods ; Swallows/*parasitology ; Symbiosis ; Wolbachia/*isolation &amp; purification ; }, abstract = {BACKGROUND: The Cimicidae are obligatory blood-feeding ectoparasites of medical and veterinary importance. We aim in the current study to assess the ability of MALDI-TOF MS to identify Cimex hirundinis swallow bugs collected in house martin nests.<br><br>METHODS: Swallow bugs were picked out from abandoned nests of house martin swallows and identified morphologically to the species level. The bugs were randomly selected, dissected and then subjected to MALDI-TOF MS and molecular analyses.<br><br>RESULTS: A total of 65 adults and 50 nymphs were used in the attempt to determine whether this tool could identify the bug species and discriminate their developmental stages. Five adults and four nymphs of C. hirundinis specimens were molecularly identified to update our MS homemade arthropod database. BLAST analysis of COI gene sequences from these C. hirundinis revealed 98.66-99.12% identity with the corresponding sequences of C. hirundinis of the GenBank. The blind test against the database supplemented with MS reference spectra showed 100% (57/57) C. hirundinis adults and 100% (46/46) C. hirundinis nymphs were reliably identified and in agreement with morphological identification with logarithmic score values between 1.922 and 2.665. Ninety-nine percent of C. hirundinis specimens tested were positive for Wolbachia spp. The sequencing results revealed that they were identical to Wolbachia massiliensis, belonging to the new T-supergroup strain and previously isolated from C. hemipterus.<br><br>CONCLUSIONS: We report for the first time to our knowledge a case of human infestation by swallow bugs (C. hirundinis) in France. We also show the usefulness of MALDI-TOF MS in the rapid identification of C. hirundinis specimens and nymphs with minimal sample requirements. We phylogenetically characterized the novel Wolbachia strain (W. massiliensis) infecting C. hirundinis and compared it to other recognized Wolbachia clades.}, }
@article {pmid34831890, year = {2021}, author = {Rousseau, R and Vanwambeke, SO and Boland, C and Mori, M}, title = {The Isolation of Culturable Bacteria in Ixodes ricinus Ticks of a Belgian Peri-Urban Forest Uncovers Opportunistic Bacteria Potentially Important for Public Health.}, journal = {International journal of environmental research and public health}, volume = {18}, number = {22}, pages = {}, pmid = {34831890}, issn = {1660-4601}, mesh = {Animals ; Bacteria/genetics ; Belgium ; Forests ; Humans ; *Ixodes ; Public Health ; }, abstract = {Most bacteria found in ticks are not pathogenic to humans but coexist as endosymbionts and may have effects on tick fitness and pathogen transmission. In this study, we cultured and isolated 78 bacteria from 954 Ixodes ricinus ticks collected in 7 sites of a Belgian peri-urban forest. Most isolated species were non-pathogenic environmental microorganisms, and were from the Firmicutes (69.23%), Actinobacteria (17.95%) and Proteobacteria (3.84%) phyla. One bacterium isolate was particularly noteworthy, Cedecea davisae, a rare opportunistic bacterium, naturally resistant to various antibiotics. It has never been isolated from ticks before and this isolated strain was resistant to ampicillin, cefoxitin and colistin. Although cultivable bacteria do not represent the complete tick microbiota, the sites presented variable bacterial compositions and diversities. This study is a first attempt to describe the culturable microbiota of ticks collected in Belgium. Further collections and analyses of ticks of different species, from various areas and using other bacterial identification methods would strengthen these results. However, they highlight the importance of ticks as potential sentinel for opportunistic bacteria of public health importance.}, }
@article {pmid34829911, year = {2021}, author = {Kwofie, SK and Broni, E and Yunus, FU and Nsoh, J and Adoboe, D and Miller, WA and Wilson, MD}, title = {Molecular Docking Simulation Studies Identifies Potential Natural Product Derived-Antiwolbachial Compounds as Filaricides against Onchocerciasis.}, journal = {Biomedicines}, volume = {9}, number = {11}, pages = {}, pmid = {34829911}, issn = {2227-9059}, abstract = {Onchocerciasis is the leading cause of blindness and severe skin lesions which remain a major public health problem, especially in tropical areas. The widespread use of antibiotics and the long duration required for effective treatment continues to add to the increasing global menace of multi-resistant pathogens. Onchocerca volvulus harbors the endosymbiont bacteria Wolbachia, essential for the normal development of embryos, larvae and long-term survival of the adult worm, O. volvulus. We report here results of using structure-based drug design (SBDD) approach aimed at identifying potential novel Wolbachia inhibitors from natural products against the Wolbachia surface protein (WSP). The protein sequence of the WSP with UniProtKB identifier Q0RAI4 was used to model the three-dimensional (3D) structure via homology modelling techniques using three different structure-building algorithms implemented in Modeller, I-TASSER and Robetta. Out of the 15 generated models of WSP, one was selected as the most reasonable quality model which had 82, 15.5, 1.9 and 0.5% of the amino acid residues in the most favored regions, additionally allowed regions, generously allowed regions and disallowed regions, respectively, based on the Ramachandran plot. High throughput virtual screening was performed via Autodock Vina with a library comprising 42,883 natural products from African and Chinese databases, including 23 identified anti-Onchocerca inhibitors. The top six compounds comprising ZINC000095913861, ZINC000095486235, ZINC000035941652, NANPDB4566, acetylaleuritolic acid and rhemannic acid had binding energies of -12.7, -11.1, -11.0, -11, -10.3 and -9.5 kcal/mol, respectively. Molecular dynamics simulations including molecular mechanics Poisson-Boltzmann (MMPBSA) calculations reinforced the stability of the ligand-WSP complexes and plausible binding mechanisms. The residues Arg45, Tyr135, Tyr148 and Phe195 were predicted as potential novel critical residues required for ligand binding in pocket 1. Acetylaleuritolic acid and rhemannic acid (lantedene A) have previously been shown to possess anti-onchocercal activity. This warrants the need to evaluate the anti-WSP activity of the identified molecules. The study suggests the exploitation of compounds which target both pockets 1 and 2, by investigating their potential for effective depletion of Wolbachia. These compounds were predicted to possess reasonably good pharmacological profiles with insignificant toxicity and as drug-like. The compounds were computed to possess biological activity including antibacterial, antiparasitic, anthelmintic and anti-rickettsials. The six natural products are potential novel antiwolbachial agents with insignificant toxicities which can be explored further as filaricides for onchocerciasis.}, }
@article {pmid34823581, year = {2021}, author = {Bleidorn, C and Henze, K}, title = {A new primer pair for barcoding of bees (Hymenoptera: Anthophila) without amplifying the orthologous coxA gene of Wolbachia bacteria.}, journal = {BMC research notes}, volume = {14}, number = {1}, pages = {427}, pmid = {34823581}, issn = {1756-0500}, mesh = {Animals ; Bacteria ; Bees/genetics ; DNA Barcoding, Taxonomic ; Hip ; *Hymenoptera ; *Wolbachia/genetics ; }, abstract = {OBJECTIVES: DNA barcoding became an effective method for the identification and monitoring of bees. However, standard primer pairs used for barcoding often result in (co-) amplification of bacterial endosymbionts of the genus Wolbachia, which are widespread among bee species. Here we designed a new primer pair and compared it with the performance of the standard Folmer-primers for a small sample set of bees representing the main taxonomic groups of bees.<br><br>RESULTS: The newly designed primer pair (BeeCox1F1/BeeCox1R2) outperformed the standard barcoding primer (LCO1490/HCO2198). By generating barcodes for a small test set of bees we found that the new primer pair produced high-quality sequences in all cases for unambiguous species identification using BOLD. Conversely, the standard barcoding primers often co-amplified the homologous Wolbachia gene and resulted in mixed chromatogram signals. These sequences showed high similarity with the bacterial endosymbiont instead of the host.}, }
@article {pmid34821769, year = {2021}, author = {Thorpe, CJ and Wang, XR and Munderloh, UG and Kurtti, TJ}, title = {Tick Cell Culture Analysis of Growth Dynamics and Cellular Tropism of Rickettsia buchneri, an Endosymbiont of the Blacklegged Tick, Ixodes scapularis.}, journal = {Insects}, volume = {12}, number = {11}, pages = {}, pmid = {34821769}, issn = {2075-4450}, abstract = {The blacklegged tick, Ixodes scapularis, a species of significant importance to human and animal health, harbors an endosymbiont Rickettsia buchneri sensu stricto. The symbiont is largely restricted to the ovaries, but all life stages can harbor various quantities or lack R. buchneri entirely. The endosymbiont is cultivable in cell lines isolated from embryos of Ixodes ticks. Rickettsia buchneri most readily grows and is maintained in the cell line IRE11 from the European tick, Ixodes ricinus. The line was characterized by light and electron microscopy and used to analyze the growth dynamics of wildtype and GFPuv-expressing R. buchneri. qPCR indicated that the genome copy doubling time in IRE11 was >7 days. Measurements of fluorescence using a plate reader indicated that the amount of green fluorescent protein doubled every 11 days. Two 23S rRNA probes were tested via RNA FISH on rickettsiae grown in vitro and adapted to evaluate the tissue tropism of R. buchneri in field-collected female I. scapularis. We observed strong positive signals of R. buchneri in the ovaries and surrounding the nucleus of the developing oocytes. Tissue tropism in I. scapularis and in vitro growth dynamics strengthen the contemporary understanding of R. buchneri as a transovarially transmitted, non-pathogenic endosymbiont.}, }
@article {pmid34820894, year = {2022}, author = {Guo, J and Hao, G and Hatt, S and Wang, Z and Francis, F}, title = {Host plant adaptability and proteomic differences of diverse Rhopalosiphum maidis (Fitch) lineages.}, journal = {Archives of insect biochemistry and physiology}, volume = {109}, number = {1}, pages = {e21853}, doi = {10.1002/arch.21853}, pmid = {34820894}, issn = {1520-6327}, mesh = {Animals ; Aphids/*metabolism/microbiology/physiology ; Enterobacteriaceae/metabolism ; Hordeum/parasitology ; Insect Proteins/metabolism ; Plant Leaves/parasitology ; *Proteome ; Serratia/metabolism ; Symbiosis ; Zea mays/parasitology ; }, abstract = {Corn leaf aphid Rhopalosiphum maidis (Fitch) can feed on various cereal crops and transmit viruses that may cause serious economic losses. To test the impact of both host plant species and age on R. maidis, as well as the proteomic difference of diverse populations, we first investigated the survival and reproduction of six R. maidis populations (i.e., LF, HF, GZ, DY, BJ, and MS) via a direct observation method in the laboratory on 10 and 50 cm high maize seedlings, and 10 cm high barley seedlings. Then a proteomic approach was implemented to identify the differentially expressed proteins from both aphids and endosymbionts of BJ and MS populations. Results indicated that the BJ population performed significantly better than the others on both barley and 50 cm high maize seedlings, while no population could survive on 10 cm high maize seedlings. The proteomic results demonstrated that the expression levels of myosin heavy chain (muscle isoform X12) (spot 781) and peroxidase (spot 1383) were upregulated, while ATP-dependent protease Hsp 100 (spot 2137) from Hamiltonella defensa and protein SYMBAF (spot 2703) from Serratia symbiotica were downregulated in the BJ population when compared to expression levels of the MS population. We hypothesize that the fatalness observed on 10 cm high maize seedlings may be caused by secondary metabolites that are synthesized by the seedlings and the MS population of R. maidis should be more stress-resistant than the BJ population. Our results also provide insights for understanding the interaction between host plants and aphids.}, }
@article {pmid34820166, year = {2021}, author = {Price, DC and Brennan, JR and Wagner, NE and Egizi, AM}, title = {Comparative hologenomics of two Ixodes scapularis tick populations in New Jersey.}, journal = {PeerJ}, volume = {9}, number = {}, pages = {e12313}, pmid = {34820166}, issn = {2167-8359}, abstract = {Tick-borne diseases, such as those transmitted by the blacklegged tick Ixodes scapularis, are a significant and growing public health problem in the US. There is mounting evidence that co-occurring non-pathogenic microbes can also impact tick-borne disease transmission. Shotgun metagenome sequencing enables sampling of the complete tick hologenome-the collective genomes of the tick and all of the microbial species contained therein, whether pathogenic, commensal or symbiotic. This approach simultaneously uncovers taxonomic composition and allows the detection of intraspecific genetic variation, making it a useful tool to compare spatial differences across tick populations. We evaluated this approach by comparing hologenome data from two tick samples (N = 6 ticks per location) collected at a relatively fine spatial scale, approximately 23 km apart, within a single US county. Several intriguing variants in the data between the two sites were detected, including polymorphisms in both in the tick's own mitochondrial DNA and that of a rickettsial endosymbiont. The two samples were broadly similar in terms of the microbial species present, including multiple known tick-borne pathogens (Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum), filarial nematodes, and Wolbachia and Babesia species. We assembled the complete genome of the rickettsial endosymbiont (most likely Rickettsia buchneri) from both populations. Our results provide further evidence for the use of shotgun metagenome sequencing as a tool to compare tick hologenomes and differentiate tick populations across localized spatial scales.}, }
@article {pmid34807291, year = {2022}, author = {Chowdanayaka, R and Basappa, RN}, title = {Rapid Divergence of Key Spermatogenesis Genes in nasuta-Subgroup of Drosophila.}, journal = {Journal of molecular evolution}, volume = {90}, number = {1}, pages = {2-16}, pmid = {34807291}, issn = {1432-1432}, mesh = {Animals ; *Drosophila/genetics ; Humans ; Hybridization, Genetic ; *Infertility, Male/genetics ; Male ; Polymorphism, Genetic ; Spermatogenesis/genetics ; }, abstract = {The crosses between closely related Drosophila species usually produce sterile hybrid males with spermatogenesis disrupted at post-meiotic phase, especially in sperm individualization stage than the pre-meiotic stage. This is possibly due to the rapid interspecies divergence of male sex and reproduction-related genes. Here we annotated 11 key spermatogenesis genes in 35 strains of species belonging to nasuta-subgroup of Drosophila, where many interspecies crosses produce sterile males. We characterized the divergence and polymorphism in the protein coding regions by employing gene-wide, codon-wide, and lineage-specific selection analysis to test the mode and strength of selection acting on these genes. Our analysis showed signature of positive selection at bag of marbles (bam) and benign gonial cell neoplasma (bgcn) despite the selection constrains and the absence of endosymbiont infection which could potentially drive rapid divergence due to an arms race while roughex (rux) showed lineage-specific rapid divergence in frontal sheen complex of nasuta-subgroup. cookie monster (comr) showed rapid divergence consistent with the possibility of meiotic arrest observed in sterile hybrids of Drosophila species. Rapid divergence observed at don juan (dj) and Mst98Ca-like was consistent with fused sperm-tail abnormality observed in the hybrids of Drosophila nasuta and Drosophila albomicans. These findings highlight the potential role of rapid nucleotide divergence in bringing about hybrid incompatibility in the form of male sterility; however, additional genetic manipulation studies can widen our understanding of hybrid incompatibilities. Furthermore, our study emphasizes the importance of young species belonging to nasuta-subgroup of Drosophila in studying post-zygotic reproductive isolation mechanisms.}, }
@article {pmid34800866, year = {2022}, author = {Duan, DY and Liu, YK and Liu, L and Liu, GH and Cheng, TY}, title = {Microbiome analysis of the midguts of different developmental stages of Argas persicus in China.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {1}, pages = {101868}, doi = {10.1016/j.ttbdis.2021.101868}, pmid = {34800866}, issn = {1877-9603}, mesh = {Animals ; *Argas/genetics ; Chickens/parasitology ; DNA, Bacterial/genetics ; Female ; *Microbiota ; RNA, Ribosomal, 16S/analysis/genetics ; }, abstract = {Argas persicus is an ectoparasite of poultry. The bacterial community structure and the pathogenic bacteria associated with different developmental stages of A. persicus have implications for control. Argas persicus were collected from chickens in the city of Jiuquan in Gansu, China. Bacterial DNA was extracted from the midgut contents of blood engorged larvae, nymphs and adult females. The V3-V4 hypervariable regions of 16S rRNA genes were sequenced using the IonS5™XL platform. Identification of Rickettsia spp. and detection of Coxiella burnetii were performed using PCR on target genes. The bacterial diversity within larvae was the highest and the bacterial diversity within nymphs was greater than that of adults. At different classification levels, seven bacterial phyla were common phyla, 27 genera were common genera, and 18 species were common species in the three samples. At the phylum level, Proteobacteria showed a marked predominance in all samples. Rickettsia, Stenotrophomonas, Spiroplasma, and Coxiella were the dominant bacteria at the genus level. The Rickettsia species in A. persicus was identified as Rickettsia hoogstraalii and the Coxiella species was identified as a Coxiella-like endosymbiont. Additionally, some bacterial species such as Pseudomonas geniculata, Sphingomonas koreensis, and Acinetobacter haemolyticus were reported here for the first time in A. persicus.}, }
@article {pmid34798529, year = {2022}, author = {Mumcuoglu, KY and Arslan-Akveran, G and Aydogdu, S and Karasartova, D and Kosar, N and Gureser, AS and Shacham, B and Taylan-Ozkan, A}, title = {Pathogens in ticks collected in Israel: I. Bacteria and protozoa in Hyalomma aegyptium and Hyalomma dromedarii collected from tortoises and camels.}, journal = {Ticks and tick-borne diseases}, volume = {13}, number = {1}, pages = {101866}, doi = {10.1016/j.ttbdis.2021.101866}, pmid = {34798529}, issn = {1877-9603}, mesh = {Animals ; Camelus/parasitology ; Israel/epidemiology ; *Ixodidae/microbiology ; *Rickettsia ; *Ticks/microbiology ; *Turtles ; }, abstract = {Ticks were collected from 30 Greek tortoise (Testudo graeca), and 10 Arabian camels (dromedary) (Camelus dromedarius) in Israel. All those collected from Greek tortoises belonged to Hyalomma aegyptium, while all specimens collected from the camels belonged to Hyalomma dromedarii. Out of 84 specimens of H. aegyptium, 31 pools were examined by PCR, while from 75 H. dromedarii specimens nine pools were studied. Out of 31 pools of H. aegyptium 26 were positive for pathogens or endosymbiont; 14 for one, 11 for two and one for three pathogens. Out of nine pools prepared from H. dromedarii, seven were positive for pathogens (two for C. burnetii and five for Leishmania infantum). In H. aegyptium, Rickettsia africae, Rickettsia aeschlimannii, Rickettsia endosymbiont, Coxiella burnetii, Hemolivia mauritanica, Babesia microti, Theileria sp., and Leishmania infantum was detected, while in H. dromedarii C. burnetii and L. infantum were found. None of the ticks were positive for Anaplasma/Ehrlichia, Listeria monocytogenes, Bartonella spp., Hepatozoon spp. and Toxoplasma gondii. H Rickettsia endosymbionts, C. burnetii, B. microti, Theileria sp. and L. infantum are reported for the first time in H. aegyptium, and C. burnetii and L. infantum for the first time in H. dromedarii.}, }
@article {pmid34791442, year = {2022}, author = {Kundu, A and Mishra, S and Kundu, P and Jogawat, A and Vadassery, J}, title = {Piriformospora indica recruits host-derived putrescine for growth promotion in plants.}, journal = {Plant physiology}, volume = {188}, number = {4}, pages = {2289-2307}, pmid = {34791442}, issn = {1532-2548}, mesh = {*Basidiomycota ; Chromatography, Liquid ; Gene Expression Regulation, Plant ; Plant Roots/metabolism ; *Putrescine/metabolism/pharmacology ; Tandem Mass Spectrometry ; }, abstract = {Growth promotion induced by the endosymbiont Piriformospora indica has been observed in various plants; however, except growth phytohormones, specific functional metabolites involved in P. indica-mediated growth promotion are unknown. Here, we used a gas chromatography-mass spectrometry-based untargeted metabolite analysis to identify tomato (Solanum lycopersicum) metabolites whose levels were altered during P. indica-mediated growth promotion. Metabolomic multivariate analysis revealed several primary metabolites with altered levels, with putrescine (Put) induced most significantly in roots during the interaction. Further, our results indicated that P. indica modulates the arginine decarboxylase (ADC)-mediated Put biosynthesis pathway via induction of SlADC1 in tomato. Piriformospora indica did not promote growth in Sladc1-(virus-induced gene silencing of SlADC1) lines of tomato and showed less colonization. Furthermore, using LC-MS/MS we showed that Put promoted growth by elevation of auxin (indole-3-acetic acid) and gibberellin (GA4 and GA7) levels in tomato. In Arabidopsis (Arabidopsis thaliana) adc knockout mutants, P. indica colonization also decreased and showed no plant growth promotion, and this response was rescued upon exogenous application of Put. Put is also important for hyphal growth of P. indica, indicating that it is co-adapted by both host and microbe. Taken together, we conclude that Put is an essential metabolite and its biosynthesis in plants is crucial for P. indica-mediated plant growth promotion and fungal growth.}, }
@article {pmid34791181, year = {2022}, author = {Mostoufi, SL and Singh, ND}, title = {Diet-induced changes in titer support a discrete response of Wolbachia-associated plastic recombination in Drosophila melanogaster.}, journal = {G3 (Bethesda, Md.)}, volume = {12}, number = {1}, pages = {}, pmid = {34791181}, issn = {2160-1836}, support = {T32 GM007413/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila melanogaster/physiology ; Phenotype ; Plastics ; Recombination, Genetic ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Plastic recombination in Drosophila melanogaster has been associated with a variety of extrinsic and intrinsic factors such as temperature, starvation, and parasite infection. The bacterial endosymbiont Wolbachia pipientis has also been associated with plastic recombination in D. melanogaster. Wolbachia infection is pervasive in arthropods and this infection induces a variety of phenotypes in its hosts, the strength of which can depend on bacterial titer. Here, we test the hypothesis that the magnitude of Wolbachia-associated plastic recombination in D. melanogaster depends on titer. To manipulate titer, we raised Wolbachia-infected and uninfected flies on diets that have previously been shown to increase or decrease Wolbachia titer relative to controls. We measured recombination in treated and control individuals using a standard backcrossing scheme with two X-linked visible markers. Our results recapitulate previous findings that Wolbachia infection is associated with increased recombination rate across the yellow-vermillion interval of the X chromosome. Our data show no significant effect of diet or diet by Wolbachia interactions on recombination, suggesting that diet-induced changes in Wolbachia titer have no effect on the magnitude of plastic recombination. These findings represent one of the first steps toward investigating Wolbachia-associated plastic recombination and demonstrate that the phenotype is a discrete response rather than a continuous one.}, }
@article {pmid34789815, year = {2021}, author = {Georgiou, A and Sieber, S and Hsiao, CC and Grayfer, T and Gorenflos López, JL and Gademann, K and Eberl, L and Bailly, A}, title = {Leaf nodule endosymbiotic Burkholderia confer targeted allelopathy to their Psychotria hosts.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {22465}, pmid = {34789815}, issn = {2045-2322}, mesh = {Allelopathy/*physiology ; Arabidopsis/drug effects/growth &amp; development ; Burkholderia/*metabolism ; Cyclohexanols/*pharmacology ; Germination/drug effects ; Lettuce/drug effects/growth &amp; development ; Meristem/drug effects/growth &amp; development ; Mustard Plant/drug effects/growth &amp; development ; Pheromones/*pharmacology ; Phylogeny ; Plant Extracts/*pharmacology ; Plant Leaves/*chemistry/metabolism/*microbiology ; Psychotria/*chemistry/metabolism/*microbiology ; Seedlings/drug effects/growth &amp; development ; Seeds/drug effects/growth &amp; development ; Symbiosis/*physiology ; }, abstract = {After a century of investigations, the function of the obligate betaproteobacterial endosymbionts accommodated in leaf nodules of tropical Rubiaceae remained enigmatic. We report that the α-D-glucose analogue (+)-streptol, systemically supplied by mature Ca. Burkholderia kirkii nodules to their Psychotria hosts, exhibits potent and selective root growth inhibiting activity. We provide compelling evidence that (+)-streptol specifically affects meristematic root cells transitioning to anisotropic elongation by disrupting cell wall organization in a mechanism of action that is distinct from canonical cellulose biosynthesis inhibitors. We observed no inhibitory or cytotoxic effects on organisms other than seed plants, further suggesting (+)-streptol as a bona fide allelochemical. We propose that the suppression of growth of plant competitors is a major driver of the formation and maintenance of the Psychotria-Burkholderia association. In addition to potential agricultural applications as a herbicidal agent, (+)-streptol might also prove useful to dissect plant cell and organ growth processes.}, }
@article {pmid34788070, year = {2022}, author = {Hirayama, H and Takaki, Y and Abe, M and Imachi, H and Ikuta, T and Miyazaki, J and Tasumi, E and Uematsu, K and Tame, A and Tsuda, M and Tanaka, K and Matsui, Y and Watanabe, HK and Yamamoto, H and Takai, K}, title = {Multispecies Populations of Methanotrophic Methyloprofundus and Cultivation of a Likely Dominant Species from the Iheya North Deep-Sea Hydrothermal Field.}, journal = {Applied and environmental microbiology}, volume = {88}, number = {2}, pages = {e0075821}, pmid = {34788070}, issn = {1098-5336}, mesh = {Animals ; Methane/metabolism ; *Methylococcaceae/genetics/metabolism ; *Microbiota ; *Mytilidae/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {The Methyloprofundus clade is represented by uncultivated methanotrophic bacterial endosymbionts of deep-sea bathymodiolin mussels, but only a single free-living species has been cultivated to date. This study reveals the existence of free-living Methyloprofundus variants in the Iheya North deep-sea hydrothermal field in the mid-Okinawa Trough. A clade-targeted amplicon analysis of the particulate methane monooxygenase gene (pmoA) detected 647 amplicon sequence variants (ASVs) of the Methyloprofundus clade in microbial communities newly formed in in situ colonization systems. Such systems were deployed at colonies of bathymodiolin mussels and a galatheoid crab in diffuse-flow areas. These ASVs were classified into 161 species-like groups. The proportion of the species-like groups representing endosymbionts of mussels was unexpectedly low. A methanotrophic bacterium designated INp10, a likely dominant species in the Methyloprofundus population in this field, was enriched in a biofilm formed in a methane-fed cultivation system operated at 10°C. Genomic characterization with the gene transcription data set of INp10 from the biofilm suggested traits advantageous to niche competition in environments, such as mobility, chemotaxis, biofilm formation, offensive and defensive systems, and hypoxia tolerance. The notable metabolic traits that INp10 shares with some Methyloprofundus members are the use of lanthanide-dependent XoxF as the sole methanol dehydrogenase due to the absence of the canonical MxaFI, the glycolytic pathway using fructose-6-phosphate aldolase instead of fructose-1,6-bisphosphate aldolase, and the potential to perform partial denitrification from nitrate under oxygen-limited conditions. These findings help us better understand the ecological strategies of this possibly widespread marine-specific methanotrophic clade. IMPORTANCE The Iheya North deep-sea hydrothermal field in the mid-Okinawa Trough is characterized by abundant methane derived from organic-rich sediments and diverse chemosynthetic animal species, including those harboring methanotrophic bacterial symbionts, such as bathymodiolin mussels Bathymodiolus japonicus and "Bathymodiolus" platifrons and a galatheoid crab, Shinkaia crosnieri. Symbiotic methanotrophs have attracted significant attention, and yet free-living methanotrophs in this environment have not been studied in detail. We focused on the free-living Methyloprofundus spp. that thrive in this hydrothermal field and identified an unexpectedly large number of species-like groups in this clade. Moreover, we enriched and characterized a methanotroph whose genome sequence indicated that it corresponds to a new species in the genus Methyloprofundus. This species might be a dominant member of the indigenous Methyloprofundus population. New information on free-living Methyloprofundus populations suggests that the hydrothermal field is a promising locale at which to investigate the adaptive capacity and associated genetic diversity of Methyloprofundus spp.}, }
@article {pmid34781749, year = {2021}, author = {Benhamou, S and Rahioui, I and Henri, H and Charles, H and Da Silva, P and Heddi, A and Vavre, F and Desouhant, E and Calevro, F and Mouton, L}, title = {Cytotype Affects the Capability of the Whitefly Bemisia tabaci MED Species To Feed and Oviposit on an Unfavorable Host Plant.}, journal = {mBio}, volume = {12}, number = {6}, pages = {e0073021}, pmid = {34781749}, issn = {2150-7511}, mesh = {Amino Acids/chemistry ; Animals ; Feeding Behavior ; Fertility ; Hemiptera/classification/*physiology ; Hibiscus/chemistry/*parasitology/physiology ; Host Specificity ; Lantana/chemistry/*parasitology/physiology ; Mitochondria/metabolism ; Oviposition ; Symbiosis ; Tobacco/chemistry/*parasitology/physiology ; }, abstract = {The acquisition of nutritional obligate primary endosymbionts (P-symbionts) allowed phloemo-phageous insects to feed on plant sap and thus colonize novel ecological niches. P-symbionts often coexist with facultative secondary endosymbionts (S-symbionts), which may also influence their hosts' niche utilization ability. The whitefly Bemisia tabaci is a highly diversified species complex harboring, in addition to the P-symbiont "Candidatus Portiera aleyrodidarum," seven S-symbionts whose roles remain poorly understood. Here, we compare the phenotypic and metabolic responses of three B. tabaci lines differing in their S-symbiont community, reared on three different host plants, hibiscus, tobacco, or lantana, and address whether and how S-symbionts influence insect capacity to feed and produce offspring on those plants. We first show that hibiscus, tobacco, and lantana differ in their free amino acid composition. Insects' performance, as well as free amino acid profile and symbiotic load, were shown to be plant dependent, suggesting a critical role for the plant nutritional properties. Insect fecundity was significantly lower on lantana, indicating that it is the least favorable plant. Remarkably, insects reared on this plant show a specific amino acid profile and a higher symbiont density compared to the two other plants. In addition, this plant was the only one for which fecundity differences were observed between lines. Using genetically homogeneous hybrids, we demonstrate that cytotype (mitochondria and symbionts), and not genotype, is a major determinant of females' fecundity and amino acid profile on lantana. As cytotypes differ in their S-symbiont community, we propose that these symbionts may mediate their hosts' suitable plant range. IMPORTANCE Microbial symbionts are universal in eukaryotes, and it is now recognized that symbiotic associations represent major evolutionary driving forces. However, the extent to which symbionts contribute to their hosts' ecological adaptation and subsequent diversification is far from being fully elucidated. The whitefly Bemisia tabaci is a sap feeder associated with multiple coinfecting intracellular facultative symbionts. Here, we show that plant species simultaneously affect whiteflies' performance, amino acid profile, and symbiotic density, which could be partially explained by differences in plant nutritional properties. We also demonstrate that, on lantana, the least favorable plant used in our study, whiteflies' performance is determined by their cytotype. We propose that the host plant utilization in B. tabaci is influenced by its facultative symbiont community composition, possibly through its impact on the host dietary requirements. Altogether, our data provide new insights into the impact of intracellular microorganisms on their animal hosts' ecological niche range and diversification.}, }
@article {pmid34773705, year = {2022}, author = {Hitchcock, TJ and Gardner, A and Ross, L}, title = {Sexual antagonism in haplodiploids.}, journal = {Evolution; international journal of organic evolution}, volume = {76}, number = {2}, pages = {292-309}, doi = {10.1111/evo.14398}, pmid = {34773705}, issn = {1558-5646}, mesh = {Alleles ; Animals ; Biological Evolution ; *Diploidy ; Female ; *Inbreeding ; Inheritance Patterns ; Male ; }, abstract = {Females and males may face different selection pressures, such that alleles conferring a benefit in one sex may be deleterious in the other. Such sexual antagonism has received a great deal of theoretical and empirical attention, almost all of which has focused on diploids. However, a sizeable minority of animals display an alternative haplodiploid mode of inheritance, encompassing both arrhenotoky, whereby males develop from unfertilized eggs, and paternal genome elimination (PGE), whereby males receive but do not transmit a paternal genome. Alongside unusual genetics, haplodiploids often exhibit social ecologies that modulate the relative value of females and males. Here, we develop a series of evolutionary-genetic models of sexual antagonism for haplodiploids, incorporating details of their molecular biology and social ecology. We find that: (1) PGE promotes female-beneficial alleles more than arrhenotoky, and to an extent determined by the timing of elimination-and degree of silencing of-the paternal genome; (2) sib-mating relatively promotes female-beneficial alleles, as do other forms of inbreeding including limited male-dispersal, oedipal-mating, and the pseudo-hermaphroditism of Icerya purchasi; (3) resource competition between related females inhibits the invasion of female-beneficial alleles; and (4) sexual antagonism foments conflicts between parents and offspring, endosymbionts and hosts, and maternal- and paternal-origin genes.}, }
@article {pmid34765121, year = {2021}, author = {Gupta, M and Kaur, R and Gupta, A and Raychoudhury, R}, title = {Are ecological communities the seat of endosymbiont horizontal transfer and diversification? A case study with soil arthropod community.}, journal = {Ecology and evolution}, volume = {11}, number = {21}, pages = {14490-14508}, pmid = {34765121}, issn = {2045-7758}, abstract = {Maternally inherited endosymbionts of arthropods are one of the most abundant and diverse group of bacteria. These bacterial endosymbionts also show extensive horizontal transfer to taxonomically unrelated hosts and widespread recombination in their genomes. Such horizontal transfers can be enhanced when different arthropod hosts come in contact like in an ecological community. Higher rates of horizontal transfer can also increase the probability of recombination between endosymbionts, as they now share the same host cytoplasm. However, reports of community-wide endosymbiont data are rare as most studies choose few host taxa and specific ecological interactions among the hosts. To better understand endosymbiont spread within host populations, we investigated the incidence, diversity, extent of horizontal transfer, and recombination of three endosymbionts (Wolbachia, Cardinium, and Arsenophonus) in a specific soil arthropod community. Wolbachia strains were characterized with MLST genes whereas 16S rRNA gene was used for Cardinium and Arsenophonus. Among 3,509 individual host arthropods, belonging to 390 morphospecies, 12.05% were infected with Wolbachia, 2.82% with Cardinium and 2.05% with Arsenophonus. Phylogenetic incongruence between host and endosymbiont indicated extensive horizontal transfer of endosymbionts within this community. Three cases of recombination between Wolbachia supergroups and eight incidences of within-supergroup recombination were also found. Statistical tests of similarity indicated supergroup A Wolbachia and Cardinium show a pattern consistent with extensive horizontal transfer within the community but not for supergroup B Wolbachia and Arsenophonus. We highlight the importance of extensive community-wide studies for a better understanding of the spread of endosymbionts across global arthropod communities.}, }
@article {pmid34749528, year = {2021}, author = {Mancini, MV and Ant, TH and Herd, CS and Martinez, J and Murdochy, SM and Gingell, DD and Mararo, E and Johnson, PCD and Sinkins, SP}, title = {High Temperature Cycles Result in Maternal Transmission and Dengue Infection Differences Between Wolbachia Strains in Aedes aegypti.}, journal = {mBio}, volume = {12}, number = {6}, pages = {e0025021}, pmid = {34749528}, issn = {2150-7511}, support = {/WT_/Wellcome Trust/United Kingdom ; 202888/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/growth &amp; development/*microbiology/virology ; Animals ; Dengue/transmission/virology ; Dengue Virus/physiology ; Ecosystem ; Female ; Humans ; Larva/*growth &amp; development/microbiology/virology ; Male ; Mosquito Control ; Mosquito Vectors/growth &amp; development/*microbiology/virology ; Population Dynamics ; Temperature ; Wolbachia/genetics/*physiology ; }, abstract = {Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist, and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity, and dengue inhibition capacity were observed for wMel. In contrast, wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. IMPORTANCE In the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Aedes aegypti mosquitoes artificially transinfected with the bacterial symbiont Wolbachia, with the ultimate aim of replacing wild mosquito populations. However, the rearing temperature of mosquito larvae is known to impact on some Wolbachia strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two Wolbachia strains, currently used for open field trials. When choosing the Wolbachia strain to be used in a dengue control program it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition. These results underline the significance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.}, }
@article {pmid34744550, year = {2022}, author = {Milenovic, M and Ghanim, M and Hoffmann, L and Rapisarda, C}, title = {Whitefly endosymbionts: IPM opportunity or tilting at windmills?.}, journal = {Journal of pest science}, volume = {95}, number = {2}, pages = {543-566}, pmid = {34744550}, issn = {1612-4758}, abstract = {Whiteflies are sap-sucking insects responsible for high economic losses. They colonize hundreds of plant species and cause direct feeding damage and indirect damage through transmission of devastating viruses. Modern agriculture has seen a history of invasive whitefly species and populations that expand to novel regions, bringing along fierce viruses. Control efforts are hindered by fast virus transmission, insecticide-resistant populations, and a wide host range which permits large natural reservoirs for whiteflies. Augmentative biocontrol by parasitoids while effective in suppressing high population densities in greenhouses falls short when it comes to preventing virus transmission and is ineffective in the open field. A potential source of much needed novel control strategies lays within a diverse community of whitefly endosymbionts. The idea to exploit endosymbionts for whitefly control is as old as identification of these bacteria, yet it still has not come to fruition. We review where our knowledge stands on the aspects of whitefly endosymbiont evolution, biology, metabolism, multitrophic interactions, and population dynamics. We show how these insights are bringing us closer to the goal of better integrated pest management strategies. Combining most up to date understanding of whitefly-endosymbiont interactions and recent technological advances, we discuss possibilities of disrupting and manipulating whitefly endosymbionts, as well as using them for pest control.}, }
@article {pmid34739816, year = {2021}, author = {Kaur, H and Kalia, A and Sharma, SP}, title = {Multi-Wall Carbon Nanotubes, Metal Oxide and Hydroxy-Apatite Nanoparticles Enhanced Plant Growth Promoting Capabilities of Root Endosymbionts of Cowpea (Vigna unguiculata (L.) Walp.).}, journal = {Journal of nanoscience and nanotechnology}, volume = {21}, number = {6}, pages = {3634-3649}, doi = {10.1166/jnn.2021.18995}, pmid = {34739816}, issn = {1533-4899}, mesh = {Apatites ; *Nanoparticles ; *Nanotubes, Carbon ; Oxides ; *Vigna ; }, abstract = {The present study was aimed to evaluate the effect of three different nanomaterials (NMs) on the growth, physiology and protein profile of the endosymbiotic bacteria isolated from the root nodules of vegetable cowpea. The alterations in growth and viability of the bacterial cells, their indole-acetic acid (IAA) and siderophore production abilities, phosphate solubilization potential and total protein content were assessed. Further, the isolates were also analyzed for changes in their exopolysaccharide (EPS) production and secretion behavior with exposure to different concentrations of the NMs. The NM supplementation of the broth improved the growth, viable cell count, IAA content, siderophore production and potential to solubilize tri-calcium phosphate (TCP) as sole phosphorus (P)-source. The NMs also improved the total protein content of the bacterial cells indicating the improved physiology and biochemistry of the treated bacterial cells. The treated cells produced significantly high EPS compared to untreated control cultures. The present investigation revealed that the NMs improved plant growth abilities of cowpea root endosymbiotic bacteria, though the impact varied across various isolates as well as NM concentrations.}, }
@article {pmid34737333, year = {2021}, author = {Marzonie, M and Flores, F and Sadoun, N and Thomas, MC and Valada-Mennuni, A and Kaserzon, S and Mueller, JF and Negri, AP}, title = {Toxicity thresholds of nine herbicides to coral symbionts (Symbiodiniaceae).}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {21636}, pmid = {34737333}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/*drug effects/*metabolism ; Conservation of Natural Resources/methods ; Coral Reefs ; Ecosystem ; Herbicides/*adverse effects/pharmacology/toxicity ; Photosynthesis/drug effects ; Photosystem II Protein Complex/drug effects ; Symbiosis/physiology ; Water Pollutants, Chemical/pharmacology ; }, abstract = {Over 30 herbicides have been detected in catchments and waters of the Great Barrier Reef (GBR) and their toxicity to key tropical species, including the coral endosymbiotic algae Symbiodiniaceae, is not generally considered in current water quality guideline values (WQGVs). Mutualistic symbionts of the family Symbiodiniaceae are essential for the survival of scleractinian corals. We tested the effects of nine GBR-relevant herbicides on photosynthetic efficiency (ΔF/Fm') and specific growth rate (SGR) over 14 days of cultured coral endosymbiont Cladocopium goreaui (formerly Symbiodinium clade C1). All seven Photosystem II (PSII) herbicides tested inhibited ΔF/Fm' and SGR, with toxicity thresholds for SGR ranging between 2.75 and 320 µg L[-1] (no effect concentration) and 2.54-257 µg L[-1] (EC10). There was a strong correlation between EC50s for ΔF/Fm' and SGR for all PSII herbicides indicating that inhibition of ΔF/Fm' can be considered a biologically relevant toxicity endpoint for PSII herbicides to this species. The non-PSII herbicides haloxyfop and imazapic did not affect ΔF/Fm' or SGR at the highest concentrations tested. The inclusion of this toxicity data for Symbiodiniaceae will contribute to improving WQGVs to adequately inform risk assessments and the management of herbicides in tropical marine ecosystems.}, }
@article {pmid34733585, year = {2021}, author = {Solak, CN and Gastineau, R and Lemieux, C and Turmel, M and Gorecka, E and Trobajo, R and Rybak, M and Yılmaz, E and Witkowski, A}, title = {Nitzschia anatoliensis sp. nov., a cryptic diatom species from the highly alkaline Van Lake (Turkey).}, journal = {PeerJ}, volume = {9}, number = {}, pages = {e12220}, pmid = {34733585}, issn = {2167-8359}, abstract = {In this article we describe Nitzschia anatoliensis Górecka, Gastineau &amp; Solak sp. nov., an example of a diatom species inhabiting extreme habitats. The new species has been isolated and successfully grown from the highly alkaline Van Lake in East Turkey. The description is based on morphology (light and scanning electron microscopy), the sequencing of its organellar genomes and several molecular phylogenies. This species could easily be overlooked because of its extreme similarity to Nitzschia aurariae but molecular phylogenies indicate that they are only distantly related. Furthermore, molecular data suggest that N. anatoliensis may occur in several alkaline lakes of Asia Minor and Siberia, but was previously misidentified as Nitzschia communis. It also revealed the very close genetic proximity between N. anatoliensis and the endosymbiont of the dinotom Kryptoperidinium foliaceum, providing additional clues on what might have been the original species of diatoms to enter symbiosis.}, }
@article {pmid34730808, year = {2022}, author = {Cummings, TFM and Gori, K and Sanchez-Pulido, L and Gavriilidis, G and Moi, D and Wilson, AR and Murchison, E and Dessimoz, C and Ponting, CP and Christophorou, MA}, title = {Citrullination Was Introduced into Animals by Horizontal Gene Transfer from Cyanobacteria.}, journal = {Molecular biology and evolution}, volume = {39}, number = {2}, pages = {}, pmid = {34730808}, issn = {1537-1719}, support = {/WT_/Wellcome Trust/United Kingdom ; MC_UU_00007/15/MRC_/Medical Research Council/United Kingdom ; 105642/A/14/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Citrullination ; Conserved Sequence ; *Cyanobacteria/genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Phylogeny ; }, abstract = {Protein posttranslational modifications add great sophistication to biological systems. Citrullination, a key regulatory mechanism in human physiology and pathophysiology, is enigmatic from an evolutionary perspective. Although the citrullinating enzymes peptidylarginine deiminases (PADIs) are ubiquitous across vertebrates, they are absent from yeast, worms, and flies. Based on this distribution PADIs were proposed to have been horizontally transferred, but this has been contested. Here, we map the evolutionary trajectory of PADIs into the animal lineage. We present strong phylogenetic support for a clade encompassing animal and cyanobacterial PADIs that excludes fungal and other bacterial homologs. The animal and cyanobacterial PADI proteins share functionally relevant primary and tertiary synapomorphic sequences that are distinct from a second PADI type present in fungi and actinobacteria. Molecular clock calculations and sequence divergence analyses using the fossil record estimate the last common ancestor of the cyanobacterial and animal PADIs to be less than 1 billion years old. Additionally, under an assumption of vertical descent, PADI sequence change during this evolutionary time frame is anachronistically low, even when compared with products of likely endosymbiont gene transfer, mitochondrial proteins, and some of the most highly conserved sequences in life. The consilience of evidence indicates that PADIs were introduced from cyanobacteria into animals by horizontal gene transfer (HGT). The ancestral cyanobacterial PADI is enzymatically active and can citrullinate eukaryotic proteins, suggesting that the PADI HGT event introduced a new catalytic capability into the regulatory repertoire of animals. This study reveals the unusual evolution of a pleiotropic protein modification.}, }
@article {pmid34728194, year = {2022}, author = {Sun, Y and Jiang, L and Gong, S and Diaz-Pulido, G and Yuan, X and Tong, H and Huang, L and Zhou, G and Zhang, Y and Huang, H}, title = {Changes in physiological performance and protein expression in the larvae of the coral Pocillopora damicornis and their symbionts in response to elevated temperature and acidification.}, journal = {The Science of the total environment}, volume = {807}, number = {Pt 2}, pages = {151251}, doi = {10.1016/j.scitotenv.2021.151251}, pmid = {34728194}, issn = {1879-1026}, mesh = {Animals ; *Anthozoa ; Ecosystem ; Hydrogen-Ion Concentration ; Larva ; Proteomics ; Temperature ; }, abstract = {Climate change causes ocean warming and acidification, which threaten coral reef ecosystems. Ocean warming and acidification cause bleaching and mortality, and decrease calcification in adult corals, leading to changes in the composition of coral communities; however, their interactive effects on coral larvae are not comprehensively understood. To examine the underlying molecular mechanisms of larval responses to elevated temperature and pCO2, we examined the physiological performance and protein expression profiles of Pocillopora damicornis at two temperatures (29 and 33 °C) and pCO2 levels (500 and 1000 μatm) for 5 d. Extensive physiological and proteomic changes were observed in coral larvae. The results indicated a significant decrease in net photosynthesis (PNET) and autotrophic capability (PNET/RD) of larvae exposed to elevated temperature but a marked increase in PNET and PNET/RD of larvae exposed to high pCO2 levels. Elevated temperature significantly reduced endosymbiont densities by 70% and photochemical efficiency, indicating that warming impaired host-symbiont symbiosis. Expression of photosynthesis-related proteins, the photosystem (PS) I reaction center subunits IV and XI as well as oxygen-evolving enhancer 1, was downregulated at higher temperatures in symbionts, whereas expression of the PS I iron‑sulfur center protein was increased under high pCO2 conditions. Furthermore, expression of phosphoribulokinase (involved in the Calvin cycle) and phosphoenolpyruvate carboxylase (related to the C4 pathway) was downregulated in symbionts under thermal stress; this finding suggests reduced carbon fixation at high temperatures. The abundance of carbonic anhydrase-associated proteins, which are predicted to exert biochemical roles in dissolved inorganic carbon transport in larvae, was reduced in coral host and symbionts at high temperatures. These results elucidate potential mechanisms underlying the responses of coral larvae exposed to elevated temperature and acidification and suggest an important role of symbionts in the response to warming and acidification.}, }
@article {pmid34726818, year = {2022}, author = {Urrutia, A and Mitsi, K and Foster, R and Ross, S and Carr, M and Ward, GM and van Aerle, R and Marigomez, I and Leger, MM and Ruiz-Trillo, I and Feist, SW and Bass, D}, title = {Txikispora philomaios n. sp., n. g., a micro-eukaryotic pathogen of amphipods, reveals parasitism and hidden diversity in Class Filasterea.}, journal = {The Journal of eukaryotic microbiology}, volume = {69}, number = {2}, pages = {e12875}, doi = {10.1111/jeu.12875}, pmid = {34726818}, issn = {1550-7408}, support = {747789/MCCC_/Marie Curie/United Kingdom ; }, mesh = {*Amphipoda/parasitology ; Animals ; Eukaryota ; Eukaryotic Cells ; Phylogeny ; Polymerase Chain Reaction ; }, abstract = {This study provides a morphological, ultrastructural, and phylogenetic characterization of a novel micro-eukaryotic parasite (2.3-2.6 µm) infecting amphipod genera Echinogammarus and Orchestia. Longitudinal studies across two years revealed that infection prevalence peaked in late April and May, reaching 64% in Echinogammarus sp. and 15% in Orchestia sp., but was seldom detected during the rest of the year. The parasite infected predominantly hemolymph, connective tissue, tegument, and gonad, although hepatopancreas and nervous tissue were affected in heavier infections, eliciting melanization and granuloma formation. Cell division occurred inside walled parasitic cysts, often within host hemocytes, resulting in hemolymph congestion. Small subunit (18S) rRNA gene phylogenies including related environmental sequences placed the novel parasite as a highly divergent lineage within Class Filasterea, which together with Choanoflagellatea represent the closest protistan relatives of Metazoa. We describe the new parasite as Txikispora philomaios n. sp. n. g., the first confirmed parasitic filasterean lineage, which otherwise comprises four free-living flagellates and a rarely observed endosymbiont of snails. Lineage-specific PCR probing of other hosts and surrounding environments only detected T. philomaios in the platyhelminth Procerodes sp. We expand the known diversity of Filasterea by targeted searches of metagenomic datasets, resulting in 13 previously unknown lineages from environmental samples.}, }
@article {pmid34726490, year = {2021}, author = {Hubert, J and Nesvorna, M and Klimov, PB and Erban, T and Sopko, B and Dowd, SE and Scully, ED}, title = {Interactions of the Intracellular Bacterium Cardinium with Its Host, the House Dust Mite Dermatophagoides farinae, Based on Gene Expression Data.}, journal = {mSystems}, volume = {6}, number = {6}, pages = {e0091621}, pmid = {34726490}, issn = {2379-5077}, abstract = {Dermatophagoides farinae is inhabited by an intracellular bacterium, Cardinium. Using correlations between host and symbiont gene expression profiles, we identified several important molecular pathways that potentially regulate/facilitate their interactions. The expression of Cardinium genes collectively explained 95% of the variation in the expression of mite genes assigned to pathways for phagocytosis, apoptosis, the MAPK signaling cascade, endocytosis, the tumor necrosis factor (TNF) pathway, the transforming growth factor beta (TGF-β) pathway, lysozyme, and the Toll/Imd pathway. In addition, expression of mite genes explained 76% of the variability in Cardinium gene expression. In particular, the expression of the Cardinium genes encoding the signaling molecules BamD, LepA, SymE, and VirD4 was either positively or negatively correlated with the expression levels of mite genes involved in endocytosis, phagocytosis, and apoptosis. We also found that Cardinium possesses a complete biosynthetic pathway for lipoic acid and may provide lipoate, but not biotin, to mites. Cardinium gene expression collectively explained 84% of the variation in expression related to several core mite metabolic pathways, and, most notably, a negative correlation was observed between bacterial gene expression and expression of mite genes assigned to the glycolysis and citric acid cycle pathways. Furthermore, we showed that Cardinium gene expression is correlated with expression levels of genes associated with terpenoid backbone biosynthesis. This pathway is important for the synthesis of pheromones, thus providing an opportunity for Cardinium to influence mite reproductive behavior to facilitate transmission of the bacterium. Overall, our study provided correlational gene expression data that can be useful for future research on mite-Cardinium interactions. IMPORTANCE The molecular mechanisms of mite-symbiont interactions and their impacts on human health are largely unknown. Astigmatid mites, such as house dust and stored-product mites, are among the most significant allergen sources worldwide. Although mites themselves are the main allergen sources, recent studies have indicated that mite-associated microbiomes may have implications for allergen production and human health. The major medically important house dust mite, D. farinae, is known to harbor a highly abundant intracellular bacterium belonging to the genus Cardinium. Expression analysis of the mite and symbiont genes can identify key mite molecular pathways that facilitate interactions with this endosymbiont and possibly shed light on how this bacterium affects mite allergen production and physiology in general.}, }
@article {pmid34724941, year = {2021}, author = {Pesante, G and Sabbadin, F and Elias, L and Steele-King, C and Shipway, JR and Dowle, AA and Li, Y and Busse-Wicher, M and Dupree, P and Besser, K and Cragg, SM and Bruce, NC and McQueen-Mason, SJ}, title = {Characterisation of the enzyme transport path between shipworms and their bacterial symbionts.}, journal = {BMC biology}, volume = {19}, number = {1}, pages = {233}, pmid = {34724941}, issn = {1741-7007}, support = {BB/H531543/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/L001926/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacteria ; *Bivalvia ; Phylogeny ; *Proteomics ; Symbiosis ; }, abstract = {BACKGROUND: Shipworms are marine xylophagus bivalve molluscs, which can live on a diet solely of wood due to their ability to produce plant cell wall-degrading enzymes. Bacterial carbohydrate-active enzymes (CAZymes), synthesised by endosymbionts living in specialised shipworm cells called bacteriocytes and located in the animal's gills, play an important role in wood digestion in shipworms. However, the main site of lignocellulose digestion within these wood-boring molluscs, which contains both endogenous lignocellulolytic enzymes and prokaryotic enzymes, is the caecum, and the mechanism by which bacterial enzymes reach the distant caecum lumen has remained so far mysterious. Here, we provide a characterisation of the path through which bacterial CAZymes produced in the gills of the shipworm Lyrodus pedicellatus reach the distant caecum to contribute to the digestion of wood.<br><br>RESULTS: Through a combination of transcriptomics, proteomics, X-ray microtomography, electron microscopy studies and in vitro biochemical characterisation, we show that wood-digesting enzymes produced by symbiotic bacteria are localised not only in the gills, but also in the lumen of the food groove, a stream of mucus secreted by gill cells that carries food particles trapped by filter feeding to the mouth. Bacterial CAZymes are also present in the crystalline style and in the caecum of their shipworm host, suggesting a unique pathway by which enzymes involved in a symbiotic interaction are transported to their site of action. Finally, we characterise in vitro four new bacterial glycosyl hydrolases and a lytic polysaccharide monooxygenase identified in our transcriptomic and proteomic analyses as some of the major bacterial enzymes involved in this unusual biological system.<br><br>CONCLUSION: Based on our data, we propose that bacteria and their enzymes are transported from the gills along the food groove to the shipworm's mouth and digestive tract, where they aid in wood digestion.}, }
@article {pmid34719095, year = {2022}, author = {Malkeyeva, D and Kiseleva, E and Fedorova, SA}, title = {Loss of Hsp67Bc leads to autolysosome enlargement in the Drosophila brain.}, journal = {Cell biology international}, volume = {46}, number = {2}, pages = {203-212}, doi = {10.1002/cbin.11721}, pmid = {34719095}, issn = {1095-8355}, mesh = {Animals ; Brain/metabolism ; *Drosophila/genetics ; *Drosophila Proteins/genetics/metabolism ; Drosophila melanogaster/metabolism ; Heat-Shock Proteins/metabolism ; Lysosomes/metabolism ; }, abstract = {Hsp67Bc is a small heat shock protein found in Drosophila melanogaster. Apart from performing a function (common for all small heat shock proteins) of preventing aggregation of misfolded proteins, it is involved in macroautophagy regulation alongside the Starvin protein. Overexpression of the D. melanogaster Hsp67Bc gene has been shown to stimulate macroautophagy in S2 cell culture. Nonetheless, it has been unknown how the absence of the Hsp67Bc gene may affect it. Here, we studied the effect of Hsp67Bc gene deletion on the macroautophagy induced by the pathogenic Wolbachia wMelPop strain in D. melanogaster. We detected Wolbachia inside autophagic vacuoles in fly neurons, thereby proving that these endosymbionts were being eliminated via macroautophagy. Nevertheless, we did not register any difference in brain bacterial load between Hsp67Bc-null and control flies at all tested stages of ontogenesis. Moreover, the abundance of autophagic vacuoles was similar between neurons of the mutant and control flies, yet the cross-sectional area of autolysosomes on ultrathin sections was more than 1.5-fold larger in Hsp67Bc-null fly brains than in the control line. Our findings suggest that the product of the Hsp67Bc gene does not participate in the initiation of endosymbiont-induced macroautophagy but may mediate autophagosome maturation: the deletion of the Hsp67Bc gene leads to the increase in autolysosome size.}, }
@article {pmid34708258, year = {2021}, author = {Deng, S and Liu, Y and Deng, Z and Huang, Y}, title = {Isolation of actinobacterial endophytes from wheat sprouts as biocontrol agents to control seed pathogenic fungi.}, journal = {Archives of microbiology}, volume = {203}, number = {10}, pages = {6163-6171}, pmid = {34708258}, issn = {1432-072X}, mesh = {*Endophytes ; Fungi ; Plant Diseases ; Seeds ; *Streptomyces ; Triticum ; }, abstract = {Seed-borne Streptomyces can transmit vertically from generation to generation and be a mutualism between the endosymbionts and hosts. The aim of this study was to isolate and characterize endophytic Streptomyces strains from wheat sprouts, and to investigate their protection against wheat seed pathogenic fungi Penicillium. Endophytic Streptomyces sp. F6 and Streptomyces sp. F39 were isolated from wheat sprouts germinated under sterile conditions. Both Streptomyces strains could produce siderophores, and showed antagonistic activities against the seed pathogenic fungi Penicillium sp. Z17. The inoculation of Streptomyces sp. F39 and F6 could protect wheat seed germination and promote seedling growth under Penicillium sp. Z17 infection. However, the protection efficiency was impacted by the Streptomyces spore concentrations, the concentration ratios of Streptomyces spores to pathogen spores, and inoculation methods. The results suggested that wheat sprouts harbored diverse endophytic Streptomyces species which derived from wheat seeds, these strains should be more likely transmitted to the next generation, and confer competitive ability to pathogens on the offspring. Owing to the more intimate correlation between sprout endophytic flora with host plants, these strains are more suitable for mature plant interiors compared with those from rhizosphere soils and root interiors.}, }
@article {pmid34704919, year = {2021}, author = {Ortiz-Baez, AS and Shi, M and Hoffmann, AA and Holmes, EC}, title = {RNA virome diversity and Wolbachia infection in individual Drosophila simulans flies.}, journal = {The Journal of general virology}, volume = {102}, number = {10}, pages = {}, pmid = {34704919}, issn = {1465-2099}, mesh = {Animals ; Drosophila simulans/*microbiology/virology ; Female ; Phylogeny ; RNA Viruses/classification/genetics/isolation &amp; purification/*physiology ; Symbiosis ; Virome/genetics/*physiology ; Wolbachia/isolation &amp; purification/*physiology ; }, abstract = {The endosymbiont bacteria of the genus Wolbachia are associated with multiple mutualistic effects on insect biology, including nutritional and antiviral properties. Members of the genus Wolbachia naturally occur in fly species of the genus Drosophila, providing an operational model host for studying how virome composition may be affected by its presence. Drosophila simulans populations can carry a variety of strains of members of the genus Wolbachia, with the wAu strain associated with strong antiviral protection under experimental conditions. We used D. simulans sampled from the Perth Hills, Western Australia, to investigate the potential virus protective effect of the wAu strain of Wolbachia on individual wild-caught flies. Our data revealed no appreciable variation in virus composition and abundance between individuals infected or uninfected with Wolbachia associated with the presence or absence of wAu. However, it remains unclear whether wAu might affect viral infection and host survival by increasing tolerance rather than inducing complete resistance. These data also provide new insights into the natural virome diversity of D. simulans. Despite the small number of individuals sampled, we identified a repertoire of RNA viruses, including nora virus, galbut virus, thika virus and La Jolla virus, that have been identified in other species of the genus Drosophila. Chaq virus-like sequences associated with galbut virus were also detected. In addition, we identified five novel viruses from the families Reoviridae, Tombusviridae, Mitoviridae and Bunyaviridae. Overall, this study highlights the complex interaction between Wolbachia and RNA virus infections and provides a baseline description of the natural virome of D. simulans.}, }
@article {pmid34699520, year = {2021}, author = {Miller, AK and Westlake, CS and Cross, KL and Leigh, BA and Bordenstein, SR}, title = {The microbiome impacts host hybridization and speciation.}, journal = {PLoS biology}, volume = {19}, number = {10}, pages = {e3001417}, pmid = {34699520}, issn = {1545-7885}, mesh = {Animals ; *Genetic Speciation ; Genome ; Host-Pathogen Interactions/*genetics ; *Hybridization, Genetic ; *Microbiota ; }, abstract = {Microbial symbiosis and speciation profoundly shape the composition of life's biodiversity. Despite the enormous contributions of these two fields to the foundations of modern biology, there is a vast and exciting frontier ahead for research, literature, and conferences to address the neglected prospects of merging their study. Here, we survey and synthesize exemplar cases of how endosymbionts and microbial communities affect animal hybridization and vice versa. We conclude that though the number of case studies remain nascent, the wide-ranging types of animals, microbes, and isolation barriers impacted by hybridization will likely prove general and a major new phase of study that includes the microbiome as part of the functional whole contributing to reproductive isolation. Though microorganisms were proposed to impact animal speciation a century ago, the weight of the evidence supporting this view has now reached a tipping point.}, }
@article {pmid34695269, year = {2021}, author = {Gimmi, E and Vorburger, C}, title = {Strong genotype-by-genotype interactions between aphid-defensive symbionts and parasitoids persist across different biotic environments.}, journal = {Journal of evolutionary biology}, volume = {34}, number = {12}, pages = {1944-1953}, pmid = {34695269}, issn = {1420-9101}, support = {31003A_181969/SNSF_/Swiss National Science Foundation/Switzerland ; }, mesh = {Animals ; *Aphids/genetics ; Genotype ; Host-Parasite Interactions ; Symbiosis ; *Wasps/genetics ; }, abstract = {The dynamics of coevolution between hosts and parasites are influenced by their genetic interactions. Highly specific interactions, where the outcome of an infection depends on the precise combination of host and parasite genotypes (G × G interactions), have the potential to maintain genetic variation by inducing negative frequency-dependent selection. The importance of this effect also rests on whether such interactions are consistent across different environments or modified by environmental variation (G × G × E interaction). In the black bean aphid, Aphis fabae, resistance to its parasitoid Lysiphlebus fabarum is largely determined by the possession of a heritable bacterial endosymbiont, Hamiltonella defensa, with strong G × G interactions between H. defensa and L. fabarum. A key environmental factor in this system is the host plant on which the aphid feeds. Here, we exposed genetically identical aphids harbouring three different strains of H. defensa to three asexual genotypes of L. fabarum and measured parasitism success on three common host plants of A. fabae, namely Vicia faba, Chenopodium album and Beta vulgaris. As expected, we observed the pervasive G × G interaction between H. defensa and L. fabarum, but despite strong main effects of the host plants on average rates of parasitism, this interaction was not altered significantly by the host plant environment (no G × G × E interaction). The symbiont-conferred specificity of resistance is thus likely to mediate the coevolution of A. fabae and L. fabarum, even when played out across diverse host plants of the aphid.}, }
@article {pmid34687882, year = {2021}, author = {Chen, H and Wang, M and Zhang, H and Wang, H and Zhou, L and Zhong, Z and Cao, L and Lian, C and Sun, Y and Li, C}, title = {microRNAs facilitate comprehensive responses of Bathymodiolinae mussel against symbiotic and nonsymbiotic bacteria stimulation.}, journal = {Fish &amp; shellfish immunology}, volume = {119}, number = {}, pages = {420-431}, doi = {10.1016/j.fsi.2021.10.025}, pmid = {34687882}, issn = {1095-9947}, mesh = {Animals ; Bacteria/genetics ; *Hydrothermal Vents ; *MicroRNAs/genetics ; *Mytilidae/genetics ; Symbiosis ; }, abstract = {Bathymodiolinae mussels are dominant species in cold seeps and hydrothermal vents and could harbor endosymbionts in gill bacteriocytes. However, mechanisms underlying the symbiosis have remained largely undisclosed for years. In the present study, the global expression pattern of immune-related genes and miRNAs were surveyed in Gigantidas platifrons during bacterial challenges using enriched symbiotic methane oxidation bacteria MOBs or nonsymbiotic Vibrio. As a result, multiple pattern recognition receptors were found differentially expressed at 12 h and 24 h post bacteria challenges and distinctly clustered between stimulations. Dozens of immune effectors along with signal transducers were also modulated simultaneously during MOB or Vibrio challenge. A total of 459 miRNAs were identified in the gill while some were differentially expressed post MOB or nonsymbiotic bacteria challenge. A variety of immune-related genes were annotated as target genes of aforesaid differentially expressed miRNAs. As a result, biological processes including the immune recognition, lysosome activity and bacteria engulfment were suggested to be dynamically modulated by miRNAs in either symbiotic or nonsymbiotic bacteria challenge. It was suggested that G. platifrons mussels could maintain a robust immune response against invading pathogens while establishing symbiosis with chemosynthetic bacteria with the orchestra of immune-related genes and miRNAs.}, }
@article {pmid34683491, year = {2021}, author = {Al-Ameeli, ZT and Al-Sammak, MA and DeLong, JP and Dunigan, DD and Van Etten, JL}, title = {Catalysis of Chlorovirus Production by the Foraging of Bursaria truncatella on Paramecia bursaria Containing Endosymbiotic Algae.}, journal = {Microorganisms}, volume = {9}, number = {10}, pages = {}, pmid = {34683491}, issn = {2076-2607}, abstract = {Chloroviruses are large viruses that replicate in chlorella-like green algae and normally exist as mutualistic endosymbionts (referred to as zoochlorellae) in protists such as Paramecium bursaria. Chlorovirus populations rise and fall in indigenous waters through time; however, the factors involved in these virus fluctuations are still under investigation. Chloroviruses attach to the surface of P. bursaria but cannot infect their zoochlorellae hosts because the viruses cannot reach the zoochlorellae as long as they are in the symbiotic phase. Predators of P. bursaria, such as copepods and didinia, can bring chloroviruses into contact with zoochlorellae by disrupting the paramecia, which results in an increase in virus titers in microcosm experiments. Here, we report that another predator of P. bursaria, Bursaria truncatella, can also increase chlorovirus titers. After two days of foraging on P. bursaria, B. truncatella increased infectious chlorovirus abundance about 20 times above the controls. Shorter term foraging (3 h) resulted in a small increase of chlorovirus titers over the controls and more foraging generated more chloroviruses. Considering that B. truncatella does not release viable zoochlorellae either during foraging or through fecal pellets, where zoochlorellae could be infected by chlorovirus, we suggest a third pathway of predator virus catalysis. By engulfing the entire protist and digesting it slowly, virus replication can occur within the predator and some of the virus is passed out through a waste vacuole. These results provide additional support for the hypothesis that predators of P. bursaria are important drivers of chlorovirus population sizes and dynamics.}, }
@article {pmid34681115, year = {2021}, author = {Muñoz-Benavent, M and Latorre, A and Alemany-Cosme, E and Marín-Miret, J and Domínguez-Santos, R and Silva, FJ and Gil, R and García-Ferris, C}, title = {Gut Microbiota Cannot Compensate the Impact of (quasi) Aposymbiosis in Blattella germanica.}, journal = {Biology}, volume = {10}, number = {10}, pages = {}, pmid = {34681115}, issn = {2079-7737}, abstract = {Blattella germanica presents a very complex symbiotic system, involving the following two kinds of symbionts: the endosymbiont Blattabacterium and the gut microbiota. Although the role of the endosymbiont has been fully elucidated, the function of the gut microbiota remains unclear. The study of the gut microbiota will benefit from the availability of insects deprived of Blattabacterium. Our goal is to determine the effect of the removal (or, at least, the reduction) of the endosymbiont population on the cockroach's fitness, in a normal gut microbiota community. For this purpose, we treated our cockroach population, over several generations, with rifampicin, an antibiotic that only affects the endosymbiont during its extracellular phase, and decreases its amount in the following generation. As rifampicin also affects gut bacteria that are sensitive to this antibiotic, the treatment was performed during the first 12 days of the adult stage, which is the period when the endosymbiont infects the oocytes and lacks bacteriocyte protection. We found that after this antibiotic treatment, the endosymbiont population remained extremely reduced and only the microbiota was able to recover, although it could not compensate for the endosymbiont role, and the host's fitness was drastically affected. This accomplished reduction, however, is not homogenous and requires further study to develop stable quasi-aposymbiotic cockroaches.}, }
@article {pmid34680698, year = {2021}, author = {Chen, XD and Kaur, N and Horton, DR and Cooper, WR and Qureshi, JA and Stelinski, LL}, title = {Crude Extracts and Alkaloids Derived from Ipomoea-Periglandula Symbiotic Association Cause Mortality of Asian Citrus Psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae).}, journal = {Insects}, volume = {12}, number = {10}, pages = {}, pmid = {34680698}, issn = {2075-4450}, abstract = {Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Psyllidae) is an important economic pest of citrus crops because it vectors the causal pathogen of huanglongbing (HLB; aka citrus greening). Population suppression of D. citri with insecticides has been disproportionally relied on for HLB management and a greater diversity of more sustainable tools is needed. Periglandula spp. is a fungal endosymbiont (family Clavicipitaceae) that forms a mutualistic relationship with members of plants in family Convolvulaceae. This association results in the production of ergot alkaloids that were previously documented as having psyllicidal properties. We investigated the mortality and behavior of D. citri exposed to crude extracts from morning glories in the plant family Convolvulaceae, as well as synthetic ergot alkaloids. Nymphs and adults were exposed to the crude plant extracts from Periglandula positive species of Convolvulaceae, as well as five synthetic ergot alkaloids. Treatments were prepared by exposing clippings of citrus to 100 ng/µL of crude extract from Periglandula-positive species of Ipomoea (I. imperati, I. leptophylla, I. pandurata and I. tricolor), and Turbina corymbosa, and from one Periglandula-negative species (I. alba) (100 ng/µL). Mortality of adult and nymphal D. citri was significantly higher than the control after exposure to extracts from I. tricolor and I. imperati. The synthetic ergot alkaloids, lysergol (10-100 ng/µL), ergonovine maleate (100 ng/µL), agroclavine (10-100 ng/µL), and ergosine (10-100 ng/µL) increased mortality of D. citri nymphs, while ergosine (100 ng/µL) and agroclavine (100 ng/µL) increased mortality of adults compared to water controls. Fewer D. citri adults settled on plants treated with crude extracts or synthetic ergot alkaloids than on water controls at 48 h after release. D. citri that fed on citrus leaves treated with 10 ng/μL solution of crude extract from the Periglandula-positive species Ipomoea (I. imperati, I. leptophylla, I. pandurata, I. tricolor), and Turbina corymbosa excreted significantly less honeydew compared with a negative water control and extract from Periglandula-negative species (I. alba). Our results indicate that crude extracts and ergot alkaloids exhibit toxic and sub-lethal effects on D. citri that could be useful for management of this pest.}, }
@article {pmid34680677, year = {2021}, author = {Horgan, FG and Peñalver Cruz, A and Arida, A and Ferrater, JB and Bernal, CC}, title = {Adaptation by the Brown Planthopper to Resistant Rice: A Test of Female-Derived Virulence and the Role of Yeast-like Symbionts.}, journal = {Insects}, volume = {12}, number = {10}, pages = {}, pmid = {34680677}, issn = {2075-4450}, abstract = {The adaptation by planthoppers to feed and develop on resistant rice is a challenge for pest management in Asia. We conducted a series of manipulative experiments with the brown planthopper (Nilaparvata lugens (Stål)) on the resistant rice variety IR62 (BPH3/BPH32 genes) to assess behavioral and bionomic changes in planthoppers exhibiting virulence adaptation. We also examined the potential role of yeast-like symbionts (YLS) in virulence adaptation by assessing progeny fitness (survival × reproduction) following controlled matings between virulent males or females and avirulent males or females, and by manipulating YLS densities in progeny through heat treatment. We found virulence-adapted planthoppers developed faster, grew larger, had adults that survived for longer, had female-biased progeny, and produced more eggs than non-selected planthoppers on the resistant variety. However, feeding capacity-as revealed through honeydew composition-remained inefficient on IR62, even after 20+ generations of exposure to the resistant host. Virulence was derived from both the male and female parents; however, females contributed more than males to progeny virulence. We found that YLS are essential for normal planthopper development and densities are highest in virulent nymphs feeding on the resistant host; however, we found only weak evidence that YLS densities contributed more to virulence. Virulence against IR62 in the brown planthopper, therefore, involves a complex of traits that encompass a series of behavioral, physiological, and genetic mechanisms, some of which are determined only by the female parent.}, }
@article {pmid34680640, year = {2021}, author = {Bell-Sakyi, L and Beliavskaia, A and Hartley, CS and Jones, L and Luu, L and Haines, LR and Hamilton, JGC and Darby, AC and Makepeace, BL}, title = {Isolation in Natural Host Cell Lines of Wolbachia Strains wPip from the Mosquito Culex pipiens and wPap from the Sand Fly Phlebotomus papatasi.}, journal = {Insects}, volume = {12}, number = {10}, pages = {}, pmid = {34680640}, issn = {2075-4450}, support = {BBS/E/I/00007039/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BBS/E/I/00002118/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 204806/Z/16/Z and 080961/Z/06/Z/WT_/Wellcome Trust/United Kingdom ; BB/P024270/1, BBS/E/I/00002118 and BBS/E/I/00007039/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/P024270/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {Endosymbiotic intracellular bacteria of the genus Wolbachia are harboured by many species of invertebrates. They display a wide range of developmental, metabolic and nutritional interactions with their hosts and may impact the transmission of arboviruses and protozoan parasites. Wolbachia have occasionally been isolated during insect cell line generation. Here, we report the isolation of two strains of Wolbachia, wPip and wPap, during cell line generation from their respective hosts, the mosquito Culex pipiens and the sand fly Phlebotomus papatasi. wPip was pathogenic for both new C. pipiens cell lines, CPE/LULS50 and CLP/LULS56, requiring tetracycline treatment to rescue the lines. In contrast, wPap was tolerated by the P. papatasi cell line PPL/LULS49, although tetracycline treatment was applied to generate a Wolbachia-free subline. Both Wolbachia strains were infective for a panel of heterologous insect and tick cell lines, including two novel lines generated from the sand fly Lutzomyia longipalpis, LLE/LULS45 and LLL/LULS52. In all cases, wPip was more pathogenic for the host cells than wPap. These newly isolated Wolbachia strains, and the novel mosquito and sand fly cell lines reported here, will add to the resources available for research on host-endosymbiont relationships, as well as on C. pipiens, P. papatasi, L. longipalpis and the pathogens that they transmit.}, }
@article {pmid34680622, year = {2021}, author = {Shapoval, NA and Nokkala, S and Nokkala, C and Kuftina, GN and Kuznetsova, VG}, title = {The Incidence of Wolbachia Bacterial Endosymbiont in Bisexual and Parthenogenetic Populations of the Psyllid Genus Cacopsylla (Hemiptera, Psylloidea).}, journal = {Insects}, volume = {12}, number = {10}, pages = {}, pmid = {34680622}, issn = {2075-4450}, abstract = {Wolbachia is one of the most common intracellular bacteria; it infects a wide variety of insects, other arthropods, and some nematodes. Wolbachia is ordinarily transmitted vertically from mother to offspring and can manipulate physiology and reproduction of their hosts in different ways, e.g., induce feminization, male killing, and parthenogenesis. Despite the great interest in Wolbachia, many aspects of its biology remain unclear and its incidence across many insect orders, including Hemiptera, is still poorly understood. In this report, we present data on Wolbachia infection in five jumping plant-lice species (Hemiptera, Psylloidea) of the genus Cacopsylla Ossiannilsson, 1970 with different reproductive strategies and test the hypothesis that Wolbachia mediates parthenogenetic and bisexual patterns observed in some Cacopsylla species. We show that the five species studied are infected with a single Wolbachia strain, belonging to the supergroup B. This strain has also been found in different insect orders (Lepidoptera, Hemiptera, Plecoptera, Orthoptera, Hymenoptera, Diptera) and even in acariform mites (Trombidiformes), suggesting extensive horizontal transmission of Wolbachia between representatives of these taxa. Our survey did not reveal significant differences in infection frequency between parthenogenetic and bisexual populations or between males and females within bisexual populations. However, infection rate varied notably in different Cacopsylla species or within distinct populations of the same species. Overall, we demonstrate that Wolbachia infects a high proportion of Cacopsylla individuals and populations, suggesting the essential role of this bacterium in their biology.}, }
@article {pmid34677126, year = {2021}, author = {Perlmutter, JI and Meyers, JE and Bordenstein, SR}, title = {A single synonymous nucleotide change impacts the male-killing phenotype of prophage WO gene wmk.}, journal = {eLife}, volume = {10}, number = {}, pages = {}, pmid = {34677126}, issn = {2050-084X}, support = {R21 AI133522/AI/NIAID NIH HHS/United States ; F31 AI143152/AI/NIAID NIH HHS/United States ; P20 GM103418/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/*genetics/metabolism ; Drosophila melanogaster/*microbiology ; Male ; Microorganisms, Genetically-Modified/genetics/physiology ; Prophages/*genetics ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia are the most widespread bacterial endosymbionts in animals. Within arthropods, these maternally transmitted bacteria can selfishly hijack host reproductive processes to increase the relative fitness of their transmitting females. One such form of reproductive parasitism called male killing, or the selective killing of infected males, is recapitulated to degrees by transgenic expression of the prophage WO-mediated killing (wmk) gene. Here, we characterize the genotype-phenotype landscape of wmk-induced male killing in D. melanogaster using transgenic expression. While phylogenetically distant wmk homologs induce no sex-ratio bias, closely-related homologs exhibit complex phenotypes spanning no death, male death, or death of all hosts. We demonstrate that alternative start codons, synonymous codons, and notably a single synonymous nucleotide in wmk can ablate killing. These findings reveal previously unrecognized features of transgenic wmk-induced killing and establish new hypotheses for the impacts of post-transcriptional processes in male killing variation. We conclude that synonymous sequence changes are not necessarily silent in nested endosymbiotic interactions with life-or-death consequences.}, }
@article {pmid34669447, year = {2022}, author = {Mendiola, SY and Stoy, KS and DiSalvo, S and Wynn, CL and Civitello, DJ and Gerardo, NM}, title = {Competitive Exclusion of Phytopathogenic Serratia marcescens from Squash Bug Vectors by the Gut Endosymbiont Caballeronia.}, journal = {Applied and environmental microbiology}, volume = {88}, number = {1}, pages = {e0155021}, pmid = {34669447}, issn = {1098-5336}, support = {R01 AI150774/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Burkholderiaceae ; *Heteroptera ; Insecta ; Serratia marcescens ; Symbiosis ; }, abstract = {Many insects harbor microbial symbiotic partners that offer protection against pathogens, parasitoids, and other natural enemies. Mounting evidence suggests that these symbiotic microbes can play key roles in determining infection outcomes in insect vectors, making them important players in the quest to develop novel vector control strategies. Using the squash bug Anasa tristis, we investigated how the presence of Caballeronia symbionts affected the persistence and intensity of phytopathogenic Serratia marcescens within the insect vector. We reared insects aposymbiotically and with different Caballeronia isolates, infected them with S. marcescens, and then sampled the insects periodically to assess the intensity and persistence of pathogen infection. Squash bugs harboring Caballeronia consistently had much lower-intensity infections and cleared S. marcescens significantly faster than their aposymbiotic counterparts. These patterns held even when we reversed the timing of exposure to symbiont and pathogen. Taken together, these results indicate that Caballeronia symbionts play an essential role in S. marcescens infection outcomes in squash bugs and could be used to alter vector competence to enhance agricultural productivity in the future. IMPORTANCE Insect-microbe symbioses have repeatedly been shown to profoundly impact an insect's ability to vector pathogens to other hosts. The use of symbiotic microbes to control insect vector populations is of growing interest in agricultural settings. Our study examines how symbiotic microbes affect the dynamics of a plant pathogen infection within the squash bug vector Anasa tristis, a well-documented pest of squash and other cucurbit plants and a vector of Serratia marcescens, the causative agent of cucurbit yellow vine disease. We provide evidence that the symbiont Caballeronia prevents successful, long-term establishment of S. marcescens in the squash bug. These findings give us insight into symbiont-pathogen dynamics within the squash bug that could ultimately determine its ability to transmit pathogens and be leveraged to interrupt disease transmission in this system.}, }
@article {pmid34668578, year = {2022}, author = {Zülfikaroğlu, T and Turgay-İzzetoğlu, G and Yikilmaz, MS and İzzetoğlu, S}, title = {Demonstrating the general structure and cell types of the fat body in Blatta orientalis (Oriental Cockroach).}, journal = {Anatomia, histologia, embryologia}, volume = {51}, number = {1}, pages = {23-35}, doi = {10.1111/ahe.12748}, pmid = {34668578}, issn = {1439-0264}, mesh = {Adipocytes ; Adipose Tissue ; Animals ; *Cockroaches ; *Fat Body ; }, abstract = {The fat body is a tissue that originates from mesoderm in insects. It consists of several cell types. The basic cell of the fat body is trophocyte. Glycogen, protein and lipid which are required for energy are stored in these cells. Mycetocyte, urocyte, chromotocyte and haemoglobin cells are the other cell types which originate from differentiated trophocytes. Of the cells found in cockroaches, mycetocytes contain an endosymbiont species of bacteria while urocytes are specialized cells for storing and discharging uric acid. Oenocyte, which is not the fat body cell type but associated with epidermis and the fat body cells, is also found in cockroaches. In this research, the fat body distribution was shown for the first time in three selected sections (thorax, beginning and end of abdomen) in all stages of Blatta orientalis (Linnaeus, 1758). In addition, the fat body cell types and distribution were determined by histological, histochemical and ultrastructural studies. As a result, trophocytes, mycetocytes, urocytes of the fat body and oenocytes which are related to the fat body were determined in B. orientalis. Also, it was revealed that the fat body content increased in the selected regions of the stages depending on the development. We hope that these findings will contribute to data about the fat body and give some directions to insecticide studies.}, }
@article {pmid34666103, year = {2021}, author = {Poopandi, S and Sundaraj, R and Rajmichael, R and Thangaraj, S and Dhamodharan, P and Biswal, J and Malaisamy, V and Jeyaraj Pandian, C and Jeyaraman, J}, title = {Computational screening of potential inhibitors targeting MurF of Brugia malayi Wolbachia through multi-scale molecular docking, molecular dynamics and MM-GBSA analysis.}, journal = {Molecular and biochemical parasitology}, volume = {246}, number = {}, pages = {111427}, doi = {10.1016/j.molbiopara.2021.111427}, pmid = {34666103}, issn = {1872-9428}, mesh = {Animals ; *Brugia malayi ; *Elephantiasis, Filarial/parasitology ; Molecular Docking Simulation ; Molecular Dynamics Simulation ; *Wolbachia/metabolism ; }, abstract = {Lymphatic filariasis is a parasitic disease caused by the worms Wuchereria bancrofti, Brugia malayi and Brugia timori. Three anti-filarial drugs namely Diethylcarbamazine, Ivermectin and Albendazole and their combinations are used as the control strategies for filariasis. The disease has received much attention in drug discovery due to the unavailability of vaccines and the toxic pharmaceutical properties of the existing drugs. In Wolbachia endosymbiont Brugia malayi, the UDP-N-acetylmuramoyl-tripeptide-d-alanyl-d-alanine ligase (MurF) plays a key role in peptidoglycan biosynthesis pathway and therefore can be considered as effective drug target against filariasis disease. Therefore, in the present study, MurF was selected as the therapeutic target to identify specific inhibitors against filariasis. Homology modeling was performed to predict the three-dimensional structure of MurF due to the absence of the experimental structure. Further molecular dynamics simulation and structure-based high throughput virtual screening with three different chemical databases (Zinc, Maybridge and Specs) were carried out to identify potent inhibitors and also to check their conformations inside the binding site of MurF, respectively. Top three compounds with high docking score and high relative binding affinity against MurF were selected. Further, validation studies, including predicted ADME (Absorption, Distribution, Metabolism, Excretion) assessment, binding free energy using MM-GBSA (Molecular Mechanics Generalized Born Surface Area) and DFT (Density Functional Theory) calculations were performed for the top three compounds. From the results, it was observed that all the three compounds were predicted to show high reactivity, acceptable range of pharmacokinetic properties and high binding affinity with the drug target MurF. Overall, the results could provide more understanding on the inhibition of MurF enzyme and the screened compounds could lead to the development of new specific anti-filarial drugs.}, }
@article {pmid34662426, year = {2022}, author = {Hill, T and Unckless, RL and Perlmutter, JI}, title = {Positive Selection and Horizontal Gene Transfer in the Genome of a Male-Killing Wolbachia.}, journal = {Molecular biology and evolution}, volume = {39}, number = {1}, pages = {}, pmid = {34662426}, issn = {1537-1719}, support = {P20 GM103418/GM/NIGMS NIH HHS/United States ; R00 GM114714/GM/NIGMS NIH HHS/United States ; R01 AI139154/AI/NIAID NIH HHS/United States ; P20 GM103638/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila/genetics/microbiology ; Drosophila melanogaster/genetics ; Gene Transfer, Horizontal ; Genome ; Male ; *Wolbachia/genetics ; }, abstract = {Wolbachia are a genus of widespread bacterial endosymbionts in which some strains can hijack or manipulate arthropod host reproduction. Male killing is one such manipulation in which these maternally transmitted bacteria benefit surviving daughters in part by removing competition with the sons for scarce resources. Despite previous findings of interesting genome features of microbial sex ratio distorters, the population genomics of male-killers remain largely uncharacterized. Here, we uncover several unique features of the genome and population genomics of four Arizonan populations of a male-killing Wolbachia strain, wInn, that infects mushroom-feeding Drosophila innubila. We first compared the wInn genome with other closely related Wolbachia genomes of Drosophila hosts in terms of genome content and confirm that the wInn genome is largely similar in overall gene content to the wMel strain infecting D. melanogaster. However, it also contains many unique genes and repetitive genetic elements that indicate lateral gene transfers between wInn and non-Drosophila eukaryotes. We also find that, in line with literature precedent, genes in the Wolbachia prophage and Octomom regions are under positive selection. Of all the genes under positive selection, many also show evidence of recent horizontal transfer among Wolbachia symbiont genomes. These dynamics of selection and horizontal gene transfer across the genomes of several Wolbachia strains and diverse host species may be important underlying factors in Wolbachia's success as a male-killer of divergent host species.}, }
@article {pmid34659281, year = {2021}, author = {Sarkar, S and Dey, A and Kumar, V and Batiha, GE and El-Esawi, MA and Tomczyk, M and Ray, P}, title = {Fungal Endophyte: An Interactive Endosymbiont With the Capability of Modulating Host Physiology in Myriad Ways.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {701800}, pmid = {34659281}, issn = {1664-462X}, abstract = {Endophytic fungi ubiquitously dwell inside the tissue-spaces of plants, mostly asymptomatically. They grow either intercellularly or intracellularly in a particular host plant to complete the whole or part of their life cycle. They have been found to be associated with almost all the plants occurring in a natural ecosystem. Due to their important role in the survival of plants (modulate photosynthesis, increase nutrient uptake, alleviate the effect of various stresses) they have been selected to co-evolve with their hosts through the course of evolution. Many years of intense research have discovered their tremendous roles in increasing the fitness of the plants in both normal and stressed conditions. There are numerous literature regarding the involvement of various endophytic fungi in enhancing plant growth, nutrient uptake, stress tolerance, etc. But, there are scant reports documenting the specific mechanisms employed by fungal endophytes to manipulate plant physiology and exert their effects. In this review, we aim to document the probable ways undertaken by endophytic fungi to alter different physiological parameters of their host plants. Our objective is to present an in-depth elucidation about the impact of fungal endophytes on plant physiology to make this evolutionarily conserved symbiotic interaction understandable from a broader perspective.}, }
@article {pmid34659173, year = {2021}, author = {Kwak, Y and Sun, P and Meduri, VR and Percy, DM and Mauck, KE and Hansen, AK}, title = {Uncovering Symbionts Across the Psyllid Tree of Life and the Discovery of a New Liberibacter Species, "Candidatus" Liberibacter capsica.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {739763}, pmid = {34659173}, issn = {1664-302X}, abstract = {Sap-feeding insects in the order Hemiptera associate with obligate endosymbionts that are required for survival and facultative endosymbionts that can potentially modify resistance to stress, enemies, development, and reproduction. In the superfamily Psylloidea, the jumping plant lice (psyllids), less is known about the diversity and prevalence of their endosymbionts compared to other sap-feeding pests such as aphids (Aphididae). To address this knowledge gap, using 16S rRNA sequencing we identify symbionts across divergent psyllid host lineages from around the world. Taking advantage of a new comprehensive phylogenomic analyses of Psylloidea, we included psyllid samples from 44 species of 35 genera of five families, collected from 11 international locations for this study. Across psyllid lineages, a total of 91 OTUs were recovered, predominantly of the Enterobacteriaceae (68%). The diversity of endosymbionts harbored by each psyllid species was low with an average of approximately 3 OTUs. Two clades of endosymbionts (clade 1 and 2), belonging to Enterobacteriaceae, were identified that appear to be long term endosymbionts of the psyllid families Triozidae and Psyllidae, respectively. We also conducted high throughput metagenomic sequencing on three Ca. Liberibacter infected psyllid species (Russelliana capsici, Trichochermes walkeri, and Macrohomotoma gladiata), initially identified from 16S rRNA sequencing, to obtain more genomic information on these putative Liberibacter plant pathogens. The phylogenomic analyses from these data identified a new Ca. Liberibacter species, Candidatus Liberibacter capsica, that is a potential pathogen of solanaceous crops. This new species shares a distant ancestor with Ca. L. americanus, which occurs in the same range as R. capsici in South America. We also detected the first association between a psyllid specializing on woody hosts and the Liberibacter species Ca. L. psyllaurous, which is a globally distributed pathogen of herbaceous crop hosts in the Solanaceae. Finally, we detected a potential association between a psyllid pest of figs (M. gladiata) and a Ca. Liberibacter related to Ca. L. asiaticus, which causes severe disease in citrus. Our findings reveal a wider diversity of associations between facultative symbionts and psyllids than previously reported and suggest numerous avenues for future work to clarify novel associations of ecological, evolutionary, and pathogenic interest.}, }
@article {pmid34659172, year = {2021}, author = {Shan, HW and Liu, SS}, title = {The Costs and Benefits of Two Secondary Symbionts in a Whitefly Host Shape Their Differential Prevalence in the Field.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {739521}, pmid = {34659172}, issn = {1664-302X}, abstract = {Insects commonly harbor maternally inherited intracellular symbionts in nature, and the microbial partners often exert influence on host reproduction and fitness to promote their prevalence. Here, we investigated composition of symbionts and their biological effects in the invasive Bemisia tabaci MED species of a whitefly complex. Our field surveys revealed that populations of the MED whitefly, in addition to the primary symbiont Portiera, mainly contain two secondary symbionts Hamiltonella, which is nearly fixed in the host populations, and Cardinium with infection frequencies ranging from 0 to 86%. We isolated and established Cardinium-positive and Cardinium-free whitefly lines with a similar nuclear genetic background from a field population, and compared performance of the two whitefly lines. The infection of Cardinium incurred significant fitness costs on the MED whitefly, including reduction of fecundity and egg viability as well as delay in development. We then selectively removed Hamiltonella from the Cardinium-free whitefly line and compared performance of two whitefly lines, one harboring both Portiera and Hamiltonella and the other harboring only Portiera. While depletion of Hamiltonella had little or only marginal effects on the fecundity, developmental rate, and offspring survival, the Hamiltonella-free whitefly line produced very few female offspring, often reducing the progeny female ratio from about 50% to less than 1%. Our findings indicate that the varying costs and benefits of the association between these two symbionts and the MED whitefly may play an important role in shaping their differential prevalence in the field.}, }
@article {pmid34657608, year = {2021}, author = {Maffo, CGT and Sandeu, MM and Fadel, AN and Tchouakui, M and Nguete, DN and Menze, B and Kusimo, MO and Njiokou, F and Hughes, GL and Wondji, CS}, title = {Molecular detection and maternal transmission of a bacterial symbiont Asaia species in field-caught Anopheles mosquitoes from Cameroon.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {539}, pmid = {34657608}, issn = {1756-3305}, support = {MR/P027873/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Acetobacteraceae/classification/*genetics ; Animals ; Anopheles/classification/*microbiology ; Cameroon ; Female ; Infectious Disease Transmission, Vertical ; Insecticide Resistance ; Mosquito Control ; Mosquito Vectors/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {BACKGROUND: Malaria control relies mainlyon insecticide-based tools. However, the effectiveness of these tools is threatened by widespread insecticide resistance in malaria vectors, highlighting the need for alternative control approaches. The endosymbiont Asaia has emerged as a promising candidate for paratransgenic control of malaria, but its biology and genetics still need to be further analyzed across Africa. Here, we investigated the prevalence of Asaia and its maternal transmission in the natural population of Anopheles mosquitoes in Cameroon.<br><br>METHODS: Indoor-resting adult mosquitoes belonging to four species (An. coluzzii, An. arabiensis, An. funestus and An. gambiae) were collected from eight localities across Cameroon from July 2016 to February 2020. PCR was performed on the Asaia-specific 16S ribosomal RNA gene, and samples positive by PCR for Asaia were confirmed by Sanger sequencing and phylogenetic analysis. The vertical transmission of Asaia was investigated by screening F1 mosquitoes belonging to F0 Asaia-positive females.<br><br>RESULTS: A total of 895 mosquitoes were screened. We found 43% (384) Asaia infection prevalence in four mosquito species. Phylogenetic analysis revealed that Asaia from Cameroon clustered together with the strains of Asaia isolated from other parts of the world. In addition, seven nucleotide sequence variants were found with low genetic diversity (&#x3c0;&#x2009;=&#x2009;0.00241) and nucleotide sequence variant diversity (Hd&#x2009;=&#x2009;0.481). Asaia was vertically transmitted with high frequency (range from 42.5 to 100%).<br><br>CONCLUSIONS: This study provides field-based evidence of the presence of Asaia in Anopheles mosquitoes in Cameroon for exploitation as a symbiont in the control of malaria in sub-Saharan Africa.}, }
@article {pmid34643449, year = {2021}, author = {Lefoulon, E and Truchon, A and Clark, T and Long, C and Frey, D and Slatko, BE}, title = {Greenhead (Tabanus nigrovittatus) Wolbachia and Its Microbiome: A Preliminary Study.}, journal = {Microbiology spectrum}, volume = {9}, number = {2}, pages = {e0051721}, pmid = {34643449}, issn = {2165-0497}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Diptera/*microbiology ; *Microbiota ; Phylogeny ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Endosymbiotic Wolbachia bacteria are known to influence the host physiology, microbiota composition, and dissemination of pathogens. We surveyed a population of Tabanus nigrovittatus, commonly referred to as "greenheads," from Crane Beach (Ipswich, MA, USA) for the presence of the alphaproteobacterial symbiont Wolbachia. We studied the COI (mitochondrial cytochrome oxidase) marker gene to evaluate the phylogenetic diversity of the studied specimens. The DNA sequences show strong similarity (between 99.9 and 98%) among the collected specimens but lower similarity to closely related entries in the NCBI database (only between 96.3 and 94.7%), suggesting a more distant relatedness. Low levels of Wolbachia presence necessitated a nested PCR approach, and using 5 markers (ftsZ, fbpA, dnaA, coxA, and gatB), we determined that two recognized "supergroups" of Wolbachia species were represented in the studied specimens, members of clades A and B. Using next-generation sequencing, we also surveyed the insect gut microbiomes of a subset of flies, using Illumina and PacBio 16S rRNA gene sequencing with barcoded primers. The composition of Proteobacteria also varied from fly to fly, with components belonging to Gammaproteobacteria making up the largest percentage of organisms (30 to 70%) among the microbiome samples. Most of the samples showed the presence of Spiroplasma, a member of the phylum Mollicutes, although the frequency of its presence was variable, ranging from 2 to 57%. Another noteworthy bacterial phylum consistently identified was Firmicutes, though the read abundances were typically below 10%. Of interest is an association between Wolbachia presence and higher Alphaproteobacteria representation in the microbiomes, suggesting that the presence of Wolbachia affects the host microbiome. IMPORTANCE Tabanus nigrovittatus greenhead populations contain two supergroups of Wolbachia endosymbionts, members of supergroups A and B. Analysis of the greenhead microbiome using next-generation sequencing revealed that the majority of bacterial species detected belonged to Gammaproteobacteria, with most of the samples also showing the presence of Spiroplasma, a member of the Mollicutes phylum also known to infect insects. An association between Wolbachia presence and higher Alphaproteobacteria representation in the microbiomes suggests that Wolbachia presence affects the host microbiome composition.}, }
@article {pmid34642800, year = {2021}, author = {Ngwewondo, A and Scandale, I and Specht, S}, title = {Onchocerciasis drug development: from preclinical models to humans.}, journal = {Parasitology research}, volume = {120}, number = {12}, pages = {3939-3964}, pmid = {34642800}, issn = {1432-1955}, mesh = {Humans ; Neglected Diseases/drug therapy/prevention &amp; control ; *Onchocerciasis/drug therapy ; *Pharmaceutical Preparations ; *Wolbachia ; }, abstract = {Twenty diseases are recognized as neglected tropical diseases (NTDs) by World Health Assembly resolutions, including human filarial diseases. The end of NTDs is embedded within the Sustainable Development Goals for 2030, under target 3.3. Onchocerciasis afflicts approximately 20.9 million people worldwide with > 90% of those infected residing in Africa. Control programs have made tremendous efforts in the management of onchocerciasis by mass drug administration and aerial larviciding; however, disease elimination is not yet achieved. In the new WHO roadmap, it is recognized that new drugs or drug regimens that kill or permanently sterilize adult filarial worms would significantly improve elimination timelines and accelerate the achievement of the program goal of disease elimination. Drug development is, however, handicapped by high attrition rates, and many promising molecules fail in preclinical development or in subsequent toxicological, safety and efficacy testing; thus, research and development (R&amp;D) costs are, in aggregate, very high. Drug discovery and development for NTDs is largely driven by unmet medical needs put forward by the global health community; the area is underfunded and since no high return on investment is possible, there is no dedicated drug development pipeline for human filariasis. Repurposing existing drugs is one approach to filling the drug development pipeline for human filariasis. The high cost and slow pace of discovery and development of new drugs has led to the repurposing of "old" drugs, as this is more cost-effective and allows development timelines to be shortened. However, even if a drug is marketed for a human or veterinary indication, the safety margin and dosing regimen will need to be re-evaluated to determine the risk in humans. Drug repurposing is a promising approach to enlarging the pool of active molecules in the drug development pipeline. Another consideration when providing new treatment options is the use of combinations, which is not addressed in this review. We here summarize recent advances in the late preclinical or early clinical stage in the search for a potent macrofilaricide, including drugs against the nematode and against its endosymbiont, Wolbachia pipientis.}, }
@article {pmid34636935, year = {2021}, author = {Wackerow-Kouzova, ND and Myagkov, DV}, title = {Clarification of the Taxonomic Position of Paramecium caudatum Micronucleus Symbionts.}, journal = {Current microbiology}, volume = {78}, number = {12}, pages = {4098-4102}, pmid = {34636935}, issn = {1432-0991}, mesh = {*Holosporaceae/genetics ; *Paramecium caudatum/genetics ; Phylogeny ; Symbiosis ; }, abstract = {Bacteria of genus Holospora (order Holosporales, class Alphaproteobacteria) are obligate intranuclear symbionts of ciliates Paramecium spp. with strict host species and nuclear (macronucleus or micronucleus) specificity. However, three species under study Holospora undulata, Holospora elegans and 'Holospora recta' occupy the same ecological niche-micronucleus of Paramecium caudatum and demonstrate some differences in morphology of infectious form. The genetic diversity of holosporas by rrs and rpoB sequence analysis was determined. Phylogenetic and phylogenomic analysis of Holospora spp., as well as some phenotypic features indicate that there is no distinctive difference supporting studied micronuclear endosymbionts as distinct species. Therefore, Holospora elegans and 'Holospora recta' should be considered subspecies of Holospora undulata (ex Haffkine 1890) Gromov and Ossipov 1981, which was described first. Thus, we confirmed the evolutionary aspects of the development of symbiotic relationships: holosporas have a strict specificity to the host species and the type of nucleus.}, }
@article {pmid34634928, year = {2021}, author = {Jiménez, NE and Gerdtzen, ZP and Olivera-Nappa, &#xc1; and Salgado, JC and Conca, C}, title = {Novel Symbiotic Genome-Scale Model Reveals Wolbachia's Arboviral Pathogen Blocking Mechanism in Aedes aegypti.}, journal = {mBio}, volume = {12}, number = {5}, pages = {e0156321}, pmid = {34634928}, issn = {2150-7511}, mesh = {Aedes/*microbiology/*virology ; Amino Acids/metabolism ; Animals ; Arboviruses/metabolism/*pathogenicity ; *Genome, Bacterial ; Host Microbial Interactions ; Lipid Metabolism ; Mosquito Vectors/microbiology/virology ; Symbiosis/*genetics ; Virus Replication/physiology ; Wolbachia/*genetics/metabolism/*virology ; }, abstract = {Wolbachia are endosymbiont bacteria known to infect arthropods causing different effects, such as cytoplasmic incompatibility and pathogen blocking in Aedes aegypti. Although several Wolbachia strains have been studied, there is little knowledge regarding the relationship between this bacterium and their hosts, particularly on their obligate endosymbiont nature and its pathogen blocking ability. Motivated by the potential applications on disease control, we developed a genome-scale model of two Wolbachia strains: wMel and the strongest Dengue blocking strain known to date: wMelPop. The obtained metabolic reconstructions exhibit an energy metabolism relying mainly on amino acids and lipid transport to support cell growth that is consistent with altered lipid and cholesterol metabolism in Wolbachia-infected mosquitoes. The obtained metabolic reconstruction was then coupled with a reconstructed mosquito model to retrieve a symbiotic genome-scale model accounting for 1,636 genes and 6,408 reactions of the Aedes aegypti-Wolbachia interaction system. Simulation of an arboviral infection in the obtained novel symbiotic model represents a metabolic scenario characterized by pathogen blocking in higher titer Wolbachia strains, showing that pathogen blocking by Wolbachia infection is consistent with competition for lipid and amino acid resources between arbovirus and this endosymbiotic bacteria. IMPORTANCE Arboviral diseases such as Zika and Dengue have been on the rise mainly due to climate change, and the development of new treatments and strategies to limit their spreading is needed. The use of Wolbachia as an approach for disease control has motivated new research related to the characterization of the mechanisms that underlie its pathogen-blocking properties. In this work, we propose a new approach for studying the metabolic interactions between Aedes aegypti and Wolbachia using genome-scale models, finding that pathogen blocking is mainly influenced by competition for the resources required for Wolbachia and viral replication.}, }
@article {pmid34627407, year = {2021}, author = {McGorum, BC and Chen, Z and Glendinning, L and Gweon, HS and Hunt, L and Ivens, A and Keen, JA and Pirie, RS and Taylor, J and Wilkinson, T and McLachlan, G}, title = {Equine grass sickness (a multiple systems neuropathy) is associated with alterations in the gastrointestinal mycobiome.}, journal = {Animal microbiome}, volume = {3}, number = {1}, pages = {70}, pmid = {34627407}, issn = {2524-4671}, abstract = {BACKGROUND: Equine grass sickness (EGS) is a multiple systems neuropathy of grazing horses of unknown aetiology. An apparently identical disease occurs in cats, dogs, rabbits, hares, sheep, alpacas and llamas. Many of the risk factors for EGS are consistent with it being a pasture mycotoxicosis. To identify potential causal fungi, the gastrointestinal mycobiota of EGS horses were evaluated using targeted amplicon sequencing, and compared with those of two control groups. Samples were collected post mortem from up to 5 sites in the gastrointestinal tracts of EGS horses (EGS group; 150 samples from 54 horses) and from control horses that were not grazing EGS pastures and that had been euthanased for reasons other than neurologic and gastrointestinal diseases (CTRL group; 67 samples from 31 horses). Faecal samples were also collected from healthy control horses that were co-grazing pastures with EGS horses at disease onset (CoG group; 48 samples from 48 horses).<br><br>RESULTS: Mycobiota at all 5 gastrointestinal sites comprised large numbers of fungi exhibiting diverse taxonomy, growth morphology, trophic mode and ecological guild. FUNGuild analysis parsed most phylotypes as ingested environmental microfungi, agaricoids and yeasts, with only 1% as gastrointestinal adapted animal endosymbionts. Mycobiota richness varied throughout the gastrointestinal tract and was greater in EGS horses. There were significant inter-group and inter-site differences in mycobiota structure. A large number of phylotypes were differentially abundant among groups. Key phylotypes (n&#x2009;=&#x2009;56) associated with EGS were identified that had high abundance and high prevalence in EGS samples, significantly increased abundance in EGS samples, and were important determinants of the inter-group differences in mycobiota structure. Many key phylotypes were extremophiles and/or were predicted to produce cytotoxic and/or neurotoxic extrolites.<br><br>CONCLUSIONS: This is the first reported molecular characterisation of the gastrointestinal mycobiota of grazing horses. Key phylotypes associated with EGS were identified. Further work is required to determine whether neurotoxic extrolites from key phylotypes contribute to EGS aetiology or whether the association of key phylotypes and EGS is a consequence of disease or is non-causal.}, }
@article {pmid34623904, year = {2022}, author = {Simon, C and Cooley, JR and Karban, R and Sota, T}, title = {Advances in the Evolution and Ecology of 13- and 17-Year Periodical Cicadas.}, journal = {Annual review of entomology}, volume = {67}, number = {}, pages = {457-482}, doi = {10.1146/annurev-ento-072121-061108}, pmid = {34623904}, issn = {1545-4487}, mesh = {Animals ; Ecology ; Ecosystem ; *Hemiptera/genetics/microbiology ; Humans ; Life Cycle Stages ; Phylogeography ; }, abstract = {Apart from model organisms, 13- and 17-year periodical cicadas (Hemiptera: Cicadidae: Magicicada) are among the most studied insects in evolution and ecology. They are attractive subjects because they predictably emerge in large numbers; have a complex biogeography shaped by both spatial and temporal isolation; and include three largely sympatric, parallel species groups that are, in a sense, evolutionary replicates. Magicicada are also relatively easy to capture and manipulate, and their spectacular, synchronized mass emergences facilitate outreach and citizen science opportunities. Since the last major review, studies of Magicicada have revealed insights into reproductive character displacement and the nature of species boundaries, provided additional examples of allochronic speciation, found evidence for repeated and parallel (but noncontemporaneous) evolution of 13- and 17-year life cycles, quantified the amount and direction of gene flow through time, revealed phylogeographic patterning resulting from paleoclimate change, examined the timing of juvenile development, and created hypotheses for the evolution of life-cycle control and the future effects of climate changeon Magicicada life cycles. New ecological studies have supported and questioned the role of prime numbers in Magicicada ecology and evolution, found bidirectional shifts in population size over generations, quantified the contribution of Magicicada to nutrient flow in forest ecosystems, and examined behavioral and biochemical interactions between Magicicada and their fungal parasites and bacterial endosymbionts.}, }
@article {pmid34621258, year = {2021}, author = {Jiao, J and Zhang, J and He, P and OuYang, X and Yu, Y and Wen, B and Sun, Y and Yuan, Q and Xiong, X}, title = {Identification of Tick-Borne Pathogens and Genotyping of Coxiella burnetii in Rhipicephalus microplus in Yunnan Province, China.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {736484}, pmid = {34621258}, issn = {1664-302X}, abstract = {Rhipicephalus microplus, a vector that can transmit many pathogens to humans and domestic animals, is widely distributed in Yunnan province, China. However, few reports on the prevalence of tick-borne pathogens (TBPs) in Rh. microplus in Yunnan are available. The aim of this study was to detect TBPs in Rh. microplus in Yunnan and to analyze the phylogenetic characterization of TBPs detected in these ticks. The adult Rh. microplus (n = 516) feeding on cattle were collected. The pooled DNA samples of these ticks were evaluated using metagenomic next-generation sequencing (mNGS) and then TBPs in individual ticks were identified using genus- or group-specific nested polymerase chain reaction (PCR) combined with DNA sequencing assay. As a result, Candidatus Rickettsia jingxinensis (24.61%, 127/516), Anaplasma marginale (13.18%, 68/516), Coxiella burnetii (3.10%, 16/516), and Coxiella-like endosymbiont (CLE) (8.33%, 43/516) were detected. The dual coinfection with Ca. R. jingxinensis and A. marginale and the triple coinfection with Ca. R. jingxinensis, A. marginale, and CLE were most frequent and detected in 3.68% (19/516) and 3.10% (16/516) of these ticks, respectively. The results provide insight into the diversity of TBPs and their coinfections in Rh. microplus in Yunnan province of China, reporting for the first time that C. burnetii had been found in Rh. microplus in China. Multilocus variable number tandem repeat analysis with 6 loci (MLVA-6) discriminated the C. burnetii detected in Rh. microplus in Yunnan into MLVA genotype 1, which is closely related to previously described genotypes found primarily in tick and human samples from different regions of the globe, indicating a potential public health threat posed by C. burnetii in Rh. microplus in Yunnan.}, }
@article {pmid34620940, year = {2021}, author = {Kuroyanagi, A and Irie, T and Kinoshita, S and Kawahata, H and Suzuki, A and Nishi, H and Sasaki, O and Takashima, R and Fujita, K}, title = {Decrease in volume and density of foraminiferal shells with progressing ocean acidification.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {19988}, pmid = {34620940}, issn = {2045-2322}, abstract = {Rapid increases in anthropogenic atmospheric CO2 partial pressure have led to a decrease in the pH of seawater. Calcifying organisms generally respond negatively to ocean acidification. Foraminifera are one of the major carbonate producers in the ocean; however, whether calcification reduction by ocean acidification affects either foraminiferal shell volume or density, or both, has yet to be investigated. In this study, we cultured asexually reproducing specimens of Amphisorus kudakajimensis, a dinoflagellate endosymbiont-bearing large benthic foraminifera (LBF), under different pH conditions (pH 7.7-8.3, NBS scale). The results suggest that changes in seawater pH would affect not only the quantity (i.e., shell volume) but also the quality (i.e., shell density) of foraminiferal calcification. We proposed that pH and temperature affect these growth parameters differently because (1) they have differences in the contribution to the calcification process (e.g., Ca[2+]-ATPase and Ω) and (2) pH mainly affects calcification and temperature mainly affects photosynthesis. Our findings also suggest that, under the IPCC RCP8.5 scenario, both ocean acidification and warming will have a significant impact on reef foraminiferal carbonate production by the end of this century, even in the tropics.}, }
@article {pmid34614366, year = {2022}, author = {Vorburger, C}, title = {Defensive Symbionts and the Evolution of Parasitoid Host Specialization.}, journal = {Annual review of entomology}, volume = {67}, number = {}, pages = {329-346}, doi = {10.1146/annurev-ento-072621-062042}, pmid = {34614366}, issn = {1545-4487}, mesh = {Animals ; *Aphids/microbiology ; Food Chain ; Host Specificity ; Symbiosis ; *Wasps ; }, abstract = {Insect host-parasitoid interactions abound in nature and are characterized by a high degree of host specialization. In addition to their behavioral and immune defenses, many host species rely on heritable bacterial endosymbionts for defense against parasitoids. Studies on aphids and flies show that resistance conferred by symbionts can be very strong and highly specific, possibly as a result of variation in symbiont-produced toxins. I argue that defensive symbionts are therefore an important source of diversifying selection, promoting the evolution of host specialization by parasitoids. This is likely to affect the structure of host-parasitoid food webs. I consider potential changes in terms of food web complexity, although the nature of these effects will also be influenced by whether maternally transmitted symbionts have some capacity for lateral transfer. This is discussed in the light of available evidence for horizontal transmission routes. Finally, I propose that defensive mutualisms other than microbial endosymbionts may also exert diversifying selection on insect parasitoids.}, }
@article {pmid34613411, year = {2022}, author = {Uthanumallian, K and Iha, C and Repetti, SI and Chan, CX and Bhattacharya, D and Duchene, S and Verbruggen, H}, title = {Tightly Constrained Genome Reduction and Relaxation of Purifying Selection during Secondary Plastid Endosymbiosis.}, journal = {Molecular biology and evolution}, volume = {39}, number = {1}, pages = {}, pmid = {34613411}, issn = {1537-1719}, mesh = {*Dinoflagellida/genetics ; Genome ; *Genome, Plastid ; Phylogeny ; Plastids/genetics ; Symbiosis/genetics ; }, abstract = {Endosymbiosis, the establishment of a former free-living prokaryotic or eukaryotic cell as an organelle inside a host cell, can dramatically alter the genomic architecture of the endosymbiont. Plastids or chloroplasts, the light-harvesting organelle of photosynthetic eukaryotes, are excellent models to study this phenomenon because plastid origin has occurred multiple times in evolution. Here, we investigate the genomic signature of molecular processes acting through secondary plastid endosymbiosis-the origination of a new plastid from a free-living eukaryotic alga. We used phylogenetic comparative methods to study gene loss and changes in selective regimes on plastid genomes, focusing on green algae that have given rise to three independent lineages with secondary plastids (euglenophytes, chlorarachniophytes, and Lepidodinium). Our results show an overall increase in gene loss associated with secondary endosymbiosis, but this loss is tightly constrained by the retention of genes essential for plastid function. The data show that secondary plastids have experienced temporary relaxation of purifying selection during secondary endosymbiosis. However, this process is tightly constrained, with selection relaxed only relative to the background in primary plastids. Purifying selection remains strong in absolute terms even during the endosymbiosis events. Selection intensity rebounds to pre-endosymbiosis levels following endosymbiosis events, demonstrating the changes in selection efficiency during different origin phases of secondary plastids. Independent endosymbiosis events in the euglenophytes, chlorarachniophytes, and Lepidodinium differ in their degree of relaxation of selection, highlighting the different evolutionary contexts of these events. This study reveals the selection-drift interplay during secondary endosymbiosis and evolutionary parallels during organellogenesis.}, }
@article {pmid34612500, year = {2021}, author = {Colosimo, G and Jackson, AC and Benton, A and Varela-Stokes, A and Iverson, J and Knapp, CR and Welch, M}, title = {Correlated Population Genetic Structure in a Three-Tiered Host-Parasite System: The Potential for Coevolution and Adaptive Divergence.}, journal = {The Journal of heredity}, volume = {112}, number = {7}, pages = {590-601}, doi = {10.1093/jhered/esab058}, pmid = {34612500}, issn = {1465-7333}, mesh = {Animals ; Genetics, Population ; *Iguanas ; *Lizards ; *Parasites ; }, abstract = {Three subspecies of Northern Bahamian Rock Iguanas, Cyclura cychlura, are currently recognized: C. c. cychlura, restricted to Andros Island, and C. c. figginsi and C. c. inornata, native to the Exuma Island chain. Populations on Andros are genetically distinct from Exuma Island populations, yet genetic divergence among populations in the Exumas is inconsistent with the 2 currently recognized subspecies from those islands. The potential consequences of this discrepancy might include the recognition of a single subspecies throughout the Exumas rather than 2. That inference also ignores evidence that populations of C. cychlura are potentially adaptively divergent. We compared patterns of population relatedness in a three-tiered host-parasite system: C. cychlura iguanas, their ticks (genus Amblyomma, preferentially parasitizing these reptiles), and Rickettsia spp. endosymbionts (within tick ectoparasites). Our results indicate that while C. c. cychlura on Andros is consistently supported as a separate clade, patterns of relatedness among populations of C. c. figginsi and C. c. inornata within the Exuma Island chain are more complex. The distribution of the hosts, different tick species, and Rickettsia spp., supports the evolutionary independence of C. c. inornata. Further, these patterns are also consistent with two independent evolutionarily significant units within C. c. figginsi. Our findings suggest coevolutionary relationships between the reptile hosts, their ectoparasites, and rickettsial organisms, suggesting local adaptation. This work also speaks to the limitations of using neutral molecular markers from a single focal taxon as the sole currency for recognizing evolutionary novelty in populations of endangered species.}, }
@article {pmid34599211, year = {2021}, author = {Hertaeg, C and Risse, M and Vorburger, C and De Moraes, CM and Mescher, MC}, title = {Aphids harbouring different endosymbionts exhibit differences in cuticular hydrocarbon profiles that can be recognized by ant mutualists.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {19559}, pmid = {34599211}, issn = {2045-2322}, mesh = {Animals ; *Ants ; Aphids/*microbiology/*physiology ; Behavior, Animal ; Hydrocarbons/chemistry/*metabolism ; Species Specificity ; *Symbiosis ; }, abstract = {Cuticular hydrocarbons (CHCs) have important communicative functions for ants, which use CHC profiles to recognize mutualistic aphid partners. Aphid endosymbionts can influence the quality of their hosts as ant mutualists, via effects on honeydew composition, and might also affect CHC profiles, suggesting that ants could potentially use CHC cues to discriminate among aphid lines harbouring different endosymbionts. We explored how several strains of Hamiltonella defensa and Regiella insecticola influence the CHC profiles of host aphids (Aphis fabae) and the ability of aphid-tending ants (Lasius niger) to distinguish the profiles of aphids hosting different endosymbionts. We found significant compositional differences between the CHCs of aphids with different infections. Some endosymbionts changed the proportions of odd-chain linear alkanes, while others changed primarily methyl-branched compounds, which may be particularly important for communication. Behavioural assays, in which we trained ants to associate CHC profiles of endosymbiont infected or uninfected aphids with food rewards, revealed that ants readily learned to distinguish differences in aphid CHC profiles associated with variation in endosymbiont strains. While previous work has documented endosymbiont effects on aphid interactions with antagonists, the current findings support the hypothesis that endosymbionts also alter traits that influence communicative interactions with ant mutualists.}, }
@article {pmid34596262, year = {2021}, author = {Guo, C and Peng, X and Wang, H and Zheng, X and Hu, P and Zhou, J and Ding, Z and Wang, X and Yang, Z}, title = {Bacterial diversity of Leptocybe invasa Fisher &amp; La Salle (Hymenoptera: Eulophidae) from different geographical conditions in China.}, journal = {Archives of insect biochemistry and physiology}, volume = {108}, number = {4}, pages = {e21847}, doi = {10.1002/arch.21847}, pmid = {34596262}, issn = {1520-6327}, mesh = {Acclimatization ; Animals ; *Bacteria/classification/genetics/isolation &amp; purification ; Genes, Bacterial ; High-Throughput Nucleotide Sequencing ; Metagenomics ; RNA, Ribosomal, 16S ; Symbiosis ; Wasps/*microbiology ; }, abstract = {Insects harbor numerous endosymbionts, including bacteria, fungi, yeast, and viruses, which could affect the ecology and behavior of their hosts. However, data regarding the effect of environmental factors on endosymbiotic bacteria of Leptocybe invasa (Hymenoptera: Eulophidae) are quite rare. In this study, we assessed the diversity of endosymbiotic bacteria of L. invasa from 10 different geographic populations collected across China through the Illumina MiSeq platform. A total of 547 OTUs were generated, which were annotated into 19 phyla, 33 classes, 75 orders, 137 families, and 274 genera. The dominant bacteria detected in L. invasa were Rickettsia, and Pantoea, Enterobacter, Pseudomonas, Acinetobacter, and Bacillus were also annotated among each population. Nevertheless, the endosymbiotic bacterial abundance and diversity varied among different populations, which was related to the local climate (annual mean high temperature). The bacterial function prediction analysis showed that these endosymbiotic bacteria were concentrated in metabolism, such as carbohydrate, amino acid, and energy metabolism. Overall, the results provide a comprehensive description of the endosymbiotic bacteria in 10 different populations of an important eucalyptus pest L. invasa, and help to understand the endosymbiotic bacterial diversity and adaptation of various conditions.}, }
@article {pmid34588907, year = {2021}, author = {Tyagi, K and Tyagi, I and Kumar, V}, title = {Insights into the gut bacterial communities of spider from wild with no evidence of phylosymbiosis.}, journal = {Saudi journal of biological sciences}, volume = {28}, number = {10}, pages = {5913-5924}, pmid = {34588907}, issn = {1319-562X}, abstract = {In the present study, an effort has been made to elucidate the gut bacterial diversity of twelve species of the family Araneidae under three subfamilies collected from 5 states of India along with their predicted metabolic role in functional metabolism. Further, we also compared the host species phylogeny based on partial cytochrome c oxidase subunit I (COI) sequences with the gut bacteria composition dendrogram to decipher the phylosymbiotic relationships. Analysis revealed the presence of 22 bacterial phyla, 145 families, and 364 genera in the gut, with Proteobacteria, Firmicutes, Actinobacteria, and Deinococcus-Thermus as the highest abundant phyla. Moreover, phylum Bacteriodetes was dominated only in Cyclosa mulmeinensis and Chlamydiae in Neoscona bengalensis. At the genus level, Bacillus, Acinetobacter, Cutibacterium, Pseudomonas, and Staphylococcus were the most dominant genera. Furthermore, the genus Prevotella was observed only in Cyclosa mulmeinensis, and endosymbiont Wolbachia only in Eriovixia laglaizei. The differential abundance analysis (DeSeq2) revealed the 19 significant ASVs represented by the genera like Acinetobacter, Vagoccoccus, Prevotella, Staphylococcus, Curvibacter, Corynebacterium, Paracoccus, Streptococcus, Microbacterium, and Pseudocitrobacter. The inter- and intra-subfamilies comparison based on diversity indices (alpha and beta diversity) revealed that the subfamily Araneinae have high richness and diversity than Argiopinae and Gasteracanthinae. The phylosymbiotic analysis revealed that there is no congruence between the gut bacteria composition dendrogram with their host phylogeny.}, }
@article {pmid34580706, year = {2021}, author = {Bubnell, JE and Fernandez-Begne, P and Ulbing, CKS and Aquadro, CF}, title = {Diverse wMel variants of Wolbachia pipientis differentially rescue fertility and cytological defects of the bag of marbles partial loss of function mutation in Drosophila melanogaster.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {12}, pages = {}, pmid = {34580706}, issn = {2160-1836}, support = {R01 GM095793/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Calcium Carbonate ; *Drosophila melanogaster/genetics ; Female ; Fertility/genetics ; Loss of Function Mutation ; Phylogeny ; *Wolbachia ; }, abstract = {In Drosophila melanogaster, the maternally inherited endosymbiont Wolbachia pipientis interacts with germline stem cell genes during oogenesis. One such gene, bag of marbles (bam) is the key switch for differentiation and also shows signals of adaptive evolution for protein diversification. These observations have led us to hypothesize that W. pipientis could be driving the adaptive evolution of bam for control of oogenesis. To test this hypothesis, we must understand the specificity of the genetic interaction between bam and W. pipientis. Previously, we documented that the W. pipientis variant, wMel, rescued the fertility of the bamBW hypomorphic mutant as a transheterozygote over a bam null. However, bamBW was generated more than 20 years ago in an uncontrolled genetic background and maintained over a balancer chromosome. Consequently, the chromosome carrying bamBW accumulated mutations that have prevented controlled experiments to further assess the interaction. Here, we used CRISPR/Cas9 to engineer the same single amino acid bam hypomorphic mutation (bamL255F) and a new bam null disruption mutation into the w1118 isogenic background. We assess the fertility of wildtype bam, bamL255F/bamnull hypomorphic, and bamL255F/bamL255F mutant females, each infected individually with 10 W. pipientis wMel variants representing three phylogenetic clades. Overall, we find that all of the W. pipientis variants tested here rescue bam hypomorphic fertility defects with wMelCS-like variants exhibiting the strongest rescue effects. In addition, these variants did not increase wildtype bam female fertility. Therefore, both bam and W. pipientis interact in genotype-specific ways to modulate female fertility, a critical fitness phenotype.}, }
@article {pmid34579766, year = {2021}, author = {Lee, H and Seo, MG and Lee, SH and Oem, JK and Kim, SH and Jeong, H and Kim, Y and Jheong, WH and Kwon, OD and Kwak, D}, title = {Relationship among bats, parasitic bat flies, and associated pathogens in Korea.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {503}, pmid = {34579766}, issn = {1756-3305}, mesh = {Animals ; Bacteria/classification/*genetics/pathogenicity ; Chiroptera/*parasitology ; Diptera/anatomy &amp; histology/classification/*microbiology/*parasitology ; Disease Reservoirs/microbiology/parasitology ; Disease Vectors ; Female ; Genetic Variation ; Male ; Parasites/classification/*genetics/pathogenicity ; Phylogeny ; Republic of Korea ; Sequence Analysis, DNA ; }, abstract = {BACKGROUND: Bats are hosts for many ectoparasites and act as reservoirs for several infectious agents, some of which exhibit zoonotic potential. Here, species of bats and bat flies were identified and screened for microorganisms that could be mediated by bat flies.<br><br>METHODS: Bat species were identified on the basis of their morphological characteristics. Bat flies associated with bat species were initially morphologically identified and further identified at the genus level by analyzing the cytochrome c oxidase subunit I gene. Different vector-borne pathogens and endosymbionts were screened using PCR to assess all possible relationships among bats, parasitic bat flies, and their associated organisms.<br><br>RESULTS: Seventy-four bat flies were collected from 198 bats; 66 of these belonged to Nycteribiidae and eight to Streblidae families. All Streblidae bat flies were hosted by Rhinolophus ferrumequinum, known as the most common Korean bat. Among the 74 tested bat flies, PCR and nucleotide sequencing data showed that 35 (47.3%) and 20 (27.0%) carried Wolbachia and Bartonella bacteria, respectively, whereas tests for Anaplasma, Borrelia, Hepatozoon, Babesia, Theileria, and Coxiella were negative. Phylogenetic analysis revealed that Wolbachia endosymbionts belonged to two different supergroups, A and F. One sequence of Bartonella was identical to that of Bartonella isolated from Taiwanese bats.<br><br>CONCLUSIONS: The vectorial role of bat flies should be checked by testing the same pathogen and bacterial organisms by collecting blood from host bats. This study is of great interest in the fields of disease ecology and public health owing to the bats' potential to transmit pathogens to humans and/or livestock.}, }
@article {pmid34578149, year = {2021}, author = {Cantanhêde, LM and Mattos, CB and Cruz, AK and Ikenohuchi, YJ and Fernandes, FG and Medeiros, EHRT and da Silva-Júnior, CF and Cupolillo, E and Ferreira, GEM and Ferreira, RGM}, title = {Overcoming the Negligence in Laboratory Diagnosis of Mucosal Leishmaniasis.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {9}, pages = {}, pmid = {34578149}, issn = {2076-0817}, abstract = {The northern region of Brazil, which has the largest number of cases of tegumentary leishmaniasis (TL) in the country, is also the region that has the highest diversity of species of vectors and Leishmania parasites. In this region, cases of mucosal leishmaniasis (ML), a clinical form of TL, exceed the national average of cases, reaching up to 12% of the total annual TL notifications. ML is associated with multiple factors, such as the parasite species and the viral endosymbiont Leishmania RNA virus 1 (LRV1). Being a chronic parasitological disease, laboratory diagnosis of ML poses a challenge for health services. Here, we evaluated more than 700 clinical samples from patients with clinical suspicion of TL, including patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis, comparing the results of parasitological tests-direct parasitological examination by microscopy (DP) and conventional PCR (cPCR) targeting of both kDNA and hsp70. The DP was performed by collecting material from lesions through biopsies (mucosal lesions) or scarification (cutaneous lesions); for PCR, a cervical brush was used for sample collection. Blood samples were tested employing standardized real-time PCR (qPCR) protocol targeting the HSP70 gene. PCR tests showed higher sensitivity than DP for both CL and ML samples. Considering ML samples only (N = 89), DP showed a sensitivity of 49.4% (N = 44) against 98.8% (N = 88) for kDNA PCR. The qPCR hsp70 for blood samples from patients with ML (N = 14) resulted in superior sensitivity (50%; N = 7) compared to DP (21.4%; N = 3) for samples from the same patients. Our results reinforced the need to implement a molecular test for the diagnosis of ML, in addition to proposing methods less invasive for collecting material from TL patients. Sample collection using a cervical brush in lesions observed in CL and ML patients is easy to perform and less invasive, compared to scarification and biopsies. Blood samples could be a good source for qPCR diagnosis for ML patients. Thus, we propose here a standardized method for collection and for performing of molecular diagnosis of clinical samples from suspicious ML patients that can be applied in reference services for improving ML diagnosis.}, }
@article {pmid34568917, year = {2021}, author = {Ettinger, CL and Byrne, FJ and Collin, MA and Carter-House, D and Walling, LL and Atkinson, PW and Redak, RA and Stajich, JE}, title = {Improved draft reference genome for the Glassy-winged Sharpshooter (Homalodisca vitripennis), a vector for Pierce's disease.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {10}, pages = {}, pmid = {34568917}, issn = {2160-1836}, support = {S10 OD016290/OD/NIH HHS/United States ; }, mesh = {Animals ; *Genome, Insect ; *Hemiptera/genetics ; Metagenome ; Pilot Projects ; *Xylella ; }, abstract = {Homalodisca vitripennis (Hemiptera: Cicadellidae), known as the glassy-winged sharpshooter, is a xylem feeding leafhopper and an important agricultural pest as a vector of Xylella fastidiosa, which causes Pierce's disease in grapes and a variety of other scorch diseases. The current H. vitripennis reference genome from the Baylor College of Medicine's i5k pilot project is a 1.4-Gb assembly with 110,000 scaffolds, which still has significant gaps making identification of genes difficult. To improve on this effort, we used a combination of Oxford Nanopore long-read sequencing technology combined with Illumina sequencing reads to generate a better assembly and first-pass annotation of the whole genome sequence of a wild-caught Californian (Tulare County) individual of H. vitripennis. The improved reference genome assembly for H. vitripennis is 1.93-Gb in length (21,254 scaffolds, N50 = 650 Mb, BUSCO completeness = 94.3%), with 33.06% of the genome masked as repetitive. In total, 108,762 gene models were predicted including 98,296 protein-coding genes and 10,466 tRNA genes. As an additional community resource, we identified 27 orthologous candidate genes of interest for future experimental work including phenotypic marker genes like white. Furthermore, as part of the assembly process, we generated four endosymbiont metagenome-assembled genomes, including a high-quality near complete 1.7-Mb Wolbachia sp. genome (1 scaffold, CheckM completeness = 99.4%). The improved genome assembly and annotation for H. vitripennis, curated set of candidate genes, and endosymbiont MAGs will be invaluable resources for future research of H. vitripennis.}, }
@article {pmid34564228, year = {2021}, author = {Xu, X and Ridland, PM and Umina, PA and Gill, A and Ross, PA and Pirtle, E and Hoffmann, AA}, title = {High Incidence of Related Wolbachia across Unrelated Leaf-Mining Diptera.}, journal = {Insects}, volume = {12}, number = {9}, pages = {}, pmid = {34564228}, issn = {2075-4450}, abstract = {The maternally inherited endosymbiont, Wolbachia pipientis, plays an important role in the ecology and evolution of many of its hosts by affecting host reproduction and fitness. Here, we investigated 13 dipteran leaf-mining species to characterize Wolbachia infections and the potential for this endosymbiont in biocontrol. Wolbachia infections were present in 12 species, including 10 species where the Wolbachia infection was at or near fixation. A comparison of Wolbachia relatedness based on the wsp/MLST gene set showed that unrelated leaf-mining species often shared similar Wolbachia, suggesting common horizontal transfer. We established a colony of Liriomyza brassicae and found adult Wolbachia density was stable; although Wolbachia density differed between the sexes, with females having a 20-fold higher density than males. Wolbachia density increased during L. brassicae development, with higher densities in pupae than larvae. We removed Wolbachia using tetracycline and performed reciprocal crosses between Wolbachia-infected and uninfected individuals. Cured females crossed with infected males failed to produce offspring, indicating that Wolbachia induced complete cytoplasmic incompatibility in L. brassicae. The results highlight the potential of Wolbachia to suppress Liriomyza pests based on approaches such as the incompatible insect technique, where infected males are released into populations lacking Wolbachia or with a different incompatible infection.}, }
@article {pmid34564160, year = {2021}, author = {De Rinaldis, G and Leone, A and De Domenico, S and Bosch-Belmar, M and Slizyte, R and Milisenda, G and Santucci, A and Albano, C and Piraino, S}, title = {Biochemical Characterization of Cassiopea andromeda (Forsskål, 1775), Another Red Sea Jellyfish in the Western Mediterranean Sea.}, journal = {Marine drugs}, volume = {19}, number = {9}, pages = {}, pmid = {34564160}, issn = {1660-3397}, mesh = {Animals ; Antioxidants ; Aquatic Organisms ; *Dietary Supplements ; Ecosystem ; Mediterranean Sea ; *Scyphozoa ; }, abstract = {Increasing frequency of native jellyfish proliferations and massive appearance of non-indigenous jellyfish species recently concur to impact Mediterranean coastal ecosystems and human activities at sea. Nonetheless, jellyfish biomass may represent an exploitable novel resource to coastal communities, with reference to its potential use in the pharmaceutical, nutritional, and nutraceutical Blue Growth sectors. The zooxanthellate jellyfish Cassiopea andromeda, Forsskål, 1775 (Cnidaria, Rhizostomeae) entered the Levant Sea through the Suez Canal and spread towards the Western Mediterranean to reach Malta, Tunisia, and recently also the Italian coasts. Here we report on the biochemical characterization and antioxidant activity of C. andromeda specimens with a discussion on their relative biological activities. The biochemical characterization of the aqueous (PBS) and hydroalcoholic (80% ethanol) soluble components of C. andromeda were performed for whole jellyfish, as well as separately for umbrella and oral arms. The insoluble components were hydrolyzed by sequential enzymatic digestion with pepsin and collagenase. The composition and antioxidant activity of the insoluble and enzymatically digestible fractions were not affected by the pre-extraction types, resulting into collagen- and non-collagen-derived peptides with antioxidant activity. Both soluble compounds and hydrolyzed fractions were characterized for the content of proteins, phenolic compounds, and lipids. The presence of compounds coming from the endosymbiont zooxanthellae was also detected. The notable yield and the considerable antioxidant activity detected make this species worthy of further study for its potential biotechnological sustainable exploitation.}, }
@article {pmid34563127, year = {2021}, author = {Deng, J and Assandri, G and Chauhan, P and Futahashi, R and Galimberti, A and Hansson, B and Lancaster, LT and Takahashi, Y and Svensson, EI and Duplouy, A}, title = {Wolbachia-driven selective sweep in a range expanding insect species.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {181}, pmid = {34563127}, issn = {2730-7182}, mesh = {Animals ; Cyprus ; *DNA, Mitochondrial/genetics ; Female ; Genetic Variation ; Odonata/*genetics/*microbiology ; Phylogeny ; *Wolbachia ; }, abstract = {BACKGROUND: Evolutionary processes can cause strong spatial genetic signatures, such as local loss of genetic diversity, or conflicting histories from mitochondrial versus nuclear markers. Investigating these genetic patterns is important, as they may reveal obscured processes and players. The maternally inherited bacterium Wolbachia is among the most widespread symbionts in insects. Wolbachia typically spreads within host species by conferring direct fitness benefits, and/or by manipulating its host reproduction to favour infected over uninfected females. Under sufficient selective advantage, the mitochondrial haplotype associated with the favoured maternally-inherited symbiotic strains will spread (i.e. hitchhike), resulting in low mitochondrial genetic variation across the host species range.<br><br>METHOD: The common bluetail damselfly (Ischnura elegans: van der Linden, 1820) has recently emerged as a model organism for genetics and genomic signatures of range expansion during climate change. Although there is accumulating data on the consequences of such expansion on the genetics of I. elegans, no study has screened for Wolbachia in the damselfly genus Ischnura. Here, we present the biogeographic variation in Wolbachia prevalence and penetrance across Europe and Japan (including samples from 17 populations), and from close relatives in the Mediterranean area (i.e. I. genei: Rambur, 1842; and I. saharensis: Aguesse, 1958).<br><br>RESULTS: Our data reveal (a) multiple Wolbachia-strains, (b) potential transfer of the symbiont through hybridization, (c) higher infection rates at higher latitudes, and (d) reduced mitochondrial diversity in the north-west populations, indicative of hitchhiking associated with the selective sweep of the most common strain. We found low mitochondrial haplotype diversity in the Wolbachia-infected north-western European populations (Sweden, Scotland, the Netherlands, Belgium, France and Italy) of I. elegans, and, conversely, higher mitochondrial diversity in populations with low penetrance of Wolbachia (Ukraine, Greece, Montenegro and Cyprus). The timing of the selective sweep associated with infected lineages was estimated between 20,000 and 44,000&#xa0;years before present, which is consistent with the end of the last glacial period about 20,000 years.<br><br>CONCLUSIONS: Our findings provide an example of how endosymbiont infections can shape spatial variation in their host evolutionary genetics during postglacial expansion. These results also challenge population genetic studies that do not consider the prevalence of symbionts in many insects, which we show can impact geographic patterns of mitochondrial genetic diversity.}, }
@article {pmid34562300, year = {2021}, author = {Ramírez, CS and Tolmie, C and Opperman, DJ and González, PJ and Rivas, MG and Brondino, CD and Ferroni, FM}, title = {Copper nitrite reductase from Sinorhizobium meliloti 2011: Crystal structure and interaction with the physiological versus a nonmetabolically related cupredoxin-like mediator.}, journal = {Protein science : a publication of the Protein Society}, volume = {30}, number = {11}, pages = {2310-2323}, pmid = {34562300}, issn = {1469-896X}, mesh = {Azurin/*chemistry ; Bacterial Proteins/*chemistry ; Crystallography, X-Ray ; Nitrite Reductases/*chemistry ; Protein Domains ; Sinorhizobium meliloti/*enzymology ; }, abstract = {We report the crystal structure of the copper-containing nitrite reductase (NirK) from the Gram-negative bacterium Sinorhizobium meliloti 2011 (Sm), together with complex structural alignment and docking studies with both non-cognate and the physiologically related pseudoazurins, SmPaz1 and SmPaz2, respectively. S. meliloti is a rhizobacterium used for the formulation of Medicago sativa bionoculants, and SmNirK plays a key role in this symbiosis through the denitrification pathway. The structure of SmNirK, solved at a resolution of 2.5 Å, showed a striking resemblance with the overall structure of the well-known Class I NirKs composed of two Greek key β-barrel domains. The activity of SmNirK is ~12% of the activity reported for classical NirKs, which could be attributed to several factors such as subtle structural differences in the secondary proton channel, solvent accessibility of the substrate channel, and that the denitrifying activity has to be finely regulated within the endosymbiont. In vitro kinetics performed in homogenous and heterogeneous media showed that both SmPaz1 and SmPaz2, which are coded in different regions of the genome, donate electrons to SmNirK with similar performance. Even though the energetics of the interprotein electron transfer (ET) process is not favorable with either electron donors, adduct formation mediated by conserved residues allows minimizing the distance between the copper centers involved in the interprotein ET process.}, }
@article {pmid34557283, year = {2021}, author = {Husain, DR and Wardhani, R}, title = {Antibacterial activity of endosymbiotic bacterial compound from Pheretima sp. earthworms inhibit the growth of Salmonella Typhi and Staphylococcus aureus: in vitro and in silico approach.}, journal = {Iranian journal of microbiology}, volume = {13}, number = {4}, pages = {537-543}, pmid = {34557283}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Earthworms coexist with various pathogenic microorganisms; thus, their immunity mechanisms have developed through a long process of adaptation, including through endogenous bacterial symbionts. This study aims to identify earthworm endosymbiont bacteria compounds and their antibacterial activity through an in vitro approach supported by an in silico approach.<br><br>MATERIALS AND METHODS: This research was conducted using the in vitro inhibition test through agar diffusion and the in silico test using molecular docking applications, namely, PyRx and Way2Drugs Prediction of Activity Spectra for Substances (PASS).<br><br>RESULTS: The in vitro results showed a potent inhibition activity with a clear zone diameter of 21.75 and 15.5 mm for Staphylococcus aureus and Salmonella Typhi, respectively. These results are supported by chromatography and in silico tests, which showed that several compounds in endosymbiotic bacteria, cyclo (phenylalanyl-prolyl) and sedanolide, have high binding affinity values with several antibiotic-related target proteins in both pathogenic bacteria. Cyclo (phenylalanyl-prolyl) has the highest binding affinity of -6.0 to dihydropteroate synthase, -8.2 to topoisomerase, and -8.2 to the outer membrane, whereas sedanolide has the highest binding affinity to DNA gyrase with approximately -7.3. This antibiotic activity was also clarified through the Way2Drugs PASS application.<br><br>CONCLUSION: Ten active compounds of endosymbiont bacteria, Cyclo (phenylalanyl-prolyl) and sedanolide were potential candidates for antibacterial compounds based on the inhibition test of the agar diffusion method and the results of reverse docking and Way2Drugs PASS.}, }
@article {pmid34557206, year = {2021}, author = {Jorrin, B and Maluk, M and Atoliya, N and Kumar, SC and Chalasani, D and Tkacz, A and Singh, P and Basu, A and Pullabhotla, SV and Kumar, M and Mohanty, SR and East, AK and Ramachandran, VK and James, EK and Podile, AR and Saxena, AK and Rao, D and Poole, PS}, title = {Genomic Diversity of Pigeon Pea (Cajanus cajan L. Millsp.) Endosymbionts in India and Selection of Potential Strains for Use as Agricultural Inoculants.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {680981}, pmid = {34557206}, issn = {1664-462X}, abstract = {Pigeon pea (Cajanus cajan L. Millsp.) is a legume crop resilient to climate change due to its tolerance to drought. It is grown by millions of resource-poor farmers in semiarid and tropical subregions of Asia and Africa and is a major contributor to their nutritional food security. Pigeon pea is the sixth most important legume in the world, with India contributing more than 70% of the total production and harbouring a wide variety of cultivars. Nevertheless, the low yield of pigeon pea grown under dry land conditions and its yield instability need to be improved. This may be done by enhancing crop nodulation and, hence, biological nitrogen fixation (BNF) by supplying effective symbiotic rhizobia through the application of "elite" inoculants. Therefore, the main aim in this study was the isolation and genomic analysis of effective rhizobial strains potentially adapted to drought conditions. Accordingly, pigeon pea endosymbionts were isolated from different soil types in Southern, Central, and Northern India. After functional characterisation of the isolated strains in terms of their ability to nodulate and promote the growth of pigeon pea, 19 were selected for full genome sequencing, along with eight commercial inoculant strains obtained from the ICRISAT culture collection. The phylogenomic analysis [Average nucleotide identity MUMmer (ANIm)] revealed that the pigeon pea endosymbionts were members of the genera Bradyrhizobium and Ensifer. Based on nodC phylogeny and nod cluster synteny, Bradyrhizobium yuanmingense was revealed as the most common endosymbiont, harbouring nod genes similar to those of Bradyrhizobium cajani and Bradyrhizobium zhanjiangense. This symbiont type (e.g., strain BRP05 from Madhya Pradesh) also outperformed all other strains tested on pigeon pea, with the notable exception of an Ensifer alkalisoli strain from North India (NBAIM29). The results provide the basis for the development of pigeon pea inoculants to increase the yield of this legume through the use of effective nitrogen-fixing rhizobia, tailored for the different agroclimatic regions of India.}, }
@article {pmid34555085, year = {2021}, author = {Lau, MJ and Hoffmann, AA and Endersby-Harshman, NM}, title = {A diagnostic primer pair to distinguish between wMel and wAlbB Wolbachia infections.}, journal = {PloS one}, volume = {16}, number = {9}, pages = {e0257781}, pmid = {34555085}, issn = {1932-6203}, mesh = {Aedes/*microbiology ; Anaplasmataceae Infections/*diagnosis/veterinary ; Animals ; DNA Primers/*genetics ; Early Diagnosis ; Female ; Sensitivity and Specificity ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Detection of the Wolbachia endosymbiont in Aedes aegypti mosquitoes through real-time polymerase chain reaction assays is widely used during and after Wolbachia releases in dengue reduction trials involving the wMel and wAlbB strains. Although several different primer pairs have been applied in current successful Wolbachia releases, they cannot be used in a single assay to distinguish between these strains. Here, we developed a new diagnostic primer pair, wMwA, which can detect the wMel or wAlbB infection in the same assay. We also tested current Wolbachia primers and show that there is variation in their performance when they are used to assess the relative density of Wolbachia. The new wMwA primers provide an accurate and efficient estimate of the presence and density of both Wolbachia infections, with practical implications for Wolbachia estimates in field collected Ae. aegypti where Wolbachia releases have taken place.}, }
@article {pmid34552138, year = {2021}, author = {Figueroa, RI and Howe-Kerr, LI and Correa, AMS}, title = {Direct evidence of sex and a hypothesis about meiosis in Symbiodiniaceae.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {18838}, pmid = {34552138}, issn = {2045-2322}, mesh = {Coral Reefs ; DNA/genetics ; Dinoflagellida/genetics/*physiology ; Flow Cytometry ; *Meiosis/physiology ; Microscopy, Confocal ; Mitosis/physiology ; Recombination, Genetic ; Reproduction ; Zygote/physiology ; }, abstract = {Dinoflagellates in the family Symbiodiniaceae are obligate endosymbionts of diverse marine invertebrates, including corals, and impact the capacity of their hosts to respond to climate change-driven ocean warming. Understanding the conditions under which increased genetic variation in Symbiodiniaceae arises via sexual recombination can support efforts to evolve thermal tolerance in these symbionts and ultimately mitigate coral bleaching, the breakdown of the coral-Symbiodiniaceae partnership under stress. However, direct observations of meiosis in Symbiodiniaceae have not been reported, despite various lines of indirect evidence that it occurs. We present the first cytological evidence of sex in Symbiodiniaceae based on nuclear DNA content and morphology using Image Flow Cytometry, Cell Sorting and Confocal Microscopy. We show the Symbiodiniaceae species, Cladocopium latusorum, undergoes gamete conjugation, zygote formation, and meiosis within a dominant reef-building coral in situ. On average, sex was detected in 1.5% of the cells analyzed (N = 10,000-40,000 cells observed per sample in a total of 20 samples obtained from 3 Pocillopora colonies). We hypothesize that meiosis follows a two-step process described in other dinoflagellates, in which diploid zygotes form dyads during meiosis I, and triads and tetrads as final products of meiosis II. This study sets the stage for investigating environmental triggers of Symbiodiniaceae sexuality and can accelerate the assisted evolution of a key coral symbiont in order to combat reef degradation.}, }
@article {pmid34548405, year = {2021}, author = {Beckmann, JF and Van Vaerenberghe, K and Akwa, DE and Cooper, BS}, title = {A single mutation weakens symbiont-induced reproductive manipulation through reductions in deubiquitylation efficiency.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {39}, pages = {}, pmid = {34548405}, issn = {1091-6490}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Cytoplasm/microbiology/*pathology ; Deubiquitinating Enzymes/metabolism ; Drosophila melanogaster/genetics/*microbiology ; Embryo, Nonmammalian/metabolism/*microbiology ; Female ; Male ; *Mutation ; *Symbiosis ; *Ubiquitination ; Wolbachia/*physiology ; }, abstract = {Animals interact with microbes that affect their performance and fitness, including endosymbionts that reside inside their cells. Maternally transmitted Wolbachia bacteria are the most common known endosymbionts, in large part because of their manipulation of host reproduction. For example, many Wolbachia cause cytoplasmic incompatibility (CI) that reduces host embryonic viability when Wolbachia-modified sperm fertilize uninfected eggs. Operons termed cifs control CI, and a single factor (cifA) rescues it, providing Wolbachia-infected females a fitness advantage. Despite CI's prevalence in nature, theory indicates that natural selection does not act to maintain CI, which varies widely in strength. Here, we investigate the genetic and functional basis of CI-strength variation observed among sister Wolbachia that infect Drosophila melanogaster subgroup hosts. We cloned, Sanger sequenced, and expressed cif repertoires from weak CI-causing wYak in Drosophila yakuba, revealing mutations suspected to weaken CI relative to model wMel in D. melanogaster A single valine-to-leucine mutation within the deubiquitylating (DUB) domain of the wYak cifB homolog (cidB) ablates a CI-like phenotype in yeast. The same mutation reduces both DUB efficiency in vitro and transgenic CI strength in the fly, each by about twofold. Our results map hypomorphic transgenic CI to reduced DUB activity and indicate that deubiquitylation is central to CI induction in cid systems. We also characterize effects of other genetic variation distinguishing wMel-like cifs Importantly, CI strength determines Wolbachia prevalence in natural systems and directly influences the efficacy of Wolbachia biocontrol strategies in transinfected mosquito systems. These approaches rely on strong CI to reduce human disease.}, }
@article {pmid34547433, year = {2021}, author = {Tang, W and Guo, M and Jiang, X and Xu, H}, title = {Expression, purification, and biochemical characterization of an NAD[+]-dependent homoserine dehydrogenase from the symbiotic Polynucleobacter necessarius subsp. necessarius.}, journal = {Protein expression and purification}, volume = {188}, number = {}, pages = {105977}, doi = {10.1016/j.pep.2021.105977}, pmid = {34547433}, issn = {1096-0279}, mesh = {Amino Acid Sequence ; Aspartic Acid/analogs &amp; derivatives/*biosynthesis/metabolism ; Bacterial Proteins/biosynthesis/*genetics/isolation &amp; purification ; Burkholderiaceae/chemistry/*enzymology/genetics ; Chromatography, Gel ; Cloning, Molecular ; Escherichia coli/genetics/metabolism ; Euplotes/microbiology ; Gene Expression ; Genetic Vectors/chemistry/metabolism ; Homoserine/metabolism ; Homoserine Dehydrogenase/biosynthesis/*genetics/isolation &amp; purification ; Kinetics ; Molecular Weight ; NAD/*metabolism ; NADP/metabolism ; Protein Multimerization ; Recombinant Fusion Proteins/biosynthesis/*genetics/isolation &amp; purification ; Sequence Alignment ; Sequence Homology, Amino Acid ; Small Ubiquitin-Related Modifier Proteins/genetics/metabolism ; Symbiosis/physiology ; }, abstract = {Homoserine dehydrogenase (HSD), encoded by the hom gene, is a key enzyme in the aspartate pathway, which reversibly catalyzes the conversion of l-aspartate β-semialdehyde to l-homoserine (l-Hse), using either NAD(H) or NADP(H) as a coenzyme. In this work, we presented the first characterization of the HSD from the symbiotic Polynucleobacter necessaries subsp. necessarius (PnHSD) produced in Escherichia coli. Sequence analysis showed that PnHSD is an ACT domain-containing monofunctional HSD with 436 amnio acid residues. SDS-PAGE and Western blot demonstrated that PnHSD could be overexpressed in E. coli BL21(DE3) cell as a soluble form by using SUMO fusion technique. It could be purified to apparent homogeneity for biochemical characterization. Size-exclusion chromatography revealed that the purified PnHSD has a native molecular mass of ∼160 kDa, indicating a homotetrameric structure. The oxidation activity of PnHSD was studied in this work. Kinetic analysis revealed that PnHSD displayed an up to 1460-fold preference for NAD[+] over NADP[+], in contrast to its homologs. The purified PnHSD displayed maximal activity at 35 °C and pH 11. Similar to its NAD[+]-dependent homolog, neither NaCl and KCl activation nor L-Thr inhibition on the enzymatic activity of PnHSD was observed. These results will contribute to a better understanding of the coenzyme specificity of the HSD family and the aspartate pathway of P. necessarius.}, }
@article {pmid34539600, year = {2021}, author = {Price, DRG and Bartley, K and Blake, DP and Karp-Tatham, E and Nunn, F and Burgess, STG and Nisbet, AJ}, title = {A Rickettsiella Endosymbiont Is a Potential Source of Essential B-Vitamins for the Poultry Red Mite, Dermanyssus gallinae.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {695346}, pmid = {34539600}, issn = {1664-302X}, abstract = {Many obligate blood-sucking arthropods rely on symbiotic bacteria to provision essential B vitamins that are either missing or at sub-optimal levels in their nutritionally challenging blood diet. The poultry red mite Dermanyssus gallinae, an obligate blood-feeding ectoparasite, is a serious threat to the hen egg industry. Poultry red mite infestation has a major impact on hen health and welfare and causes a significant reduction in both egg quality and production. Thus far, the identity and biological role of nutrient provisioning bacterial mutualists from D. gallinae are little understood. Here, we demonstrate that an obligate intracellular bacterium of the Rickettsiella genus is detected in D. gallinae mites collected from 63 sites (from 15 countries) across Europe. In addition, we report the genome sequence of Rickettsiella from D. gallinae (Rickettsiella - D. gallinae endosymbiont; Rickettsiella DGE). Rickettsiella DGE has a circular 1.89Mbp genome that encodes 1,973 proteins. Phylogenetic analysis confirms the placement of Rickettsiella DGE within the Rickettsiella genus, related to a facultative endosymbiont from the pea aphid and Coxiella-like endosymbionts (CLEs) from blood feeding ticks. Analysis of the Rickettsiella DGE genome reveals that many protein-coding sequences are either pseudogenized or lost, but Rickettsiella DGE has retained several B vitamin biosynthesis pathways, suggesting the importance of these pathways in evolution of a nutritional symbiosis with D. gallinae. In silico metabolic pathway reconstruction revealed that Rickettsiella DGE is unable to synthesize protein amino acids and, therefore, amino acids are potentially provisioned by the host. In contrast, Rickettsiella DGE retains biosynthetic pathways for B vitamins: thiamine (vitamin B1) via the salvage pathway; riboflavin (vitamin B2) and pyridoxine (vitamin B6) and the cofactors: flavin adenine dinucleotide (FAD) and coenzyme A (CoA) that likely provision these nutrients to the host.}, }
@article {pmid34533888, year = {2021}, author = {Nagase, H and Watanabe, T and Koshikawa, N and Yamamoto, S and Takenaga, K and Lin, J}, title = {Mitochondria: Endosymbiont bacteria DNA sequence as a target against cancer.}, journal = {Cancer science}, volume = {112}, number = {12}, pages = {4834-4843}, pmid = {34533888}, issn = {1349-7006}, mesh = {Genome, Mitochondrial/drug effects ; Humans ; Mitochondria/drug effects/*genetics ; Molecular Targeted Therapy ; Mutation ; Neoplasms/drug therapy/*genetics ; Organophosphorus Compounds/chemistry/*pharmacology/therapeutic use ; }, abstract = {As the energy factory for the cell, the mitochondrion, through its role of adenosine triphosphate production by oxidative phosphorylation, can be regarded as the guardian of well regulated cellular metabolism; the integrity of mitochondrial functions, however, is particularly vulnerable in cancer due to the lack of superstructures such as histone and lamina folds to protect the mitochondrial genome from unintended exposure, which consequently elevates risks of mutation. In cancer, mechanisms responsible for enforcing quality control surveillance for identifying and eliminating defective mitochondria are often poorly regulated, and certain uneliminated mitochondrial DNA (mtDNA) mutations and polymorphisms can be advantageous for the proliferation, progression, and metastasis of tumor cells. Such pathogenic mtDNA aberrations are likely to increase and occasionally be homoplasmic in cancer cells and, intriguingly, in normal cells in the proximity of tumor microenvironments as well. Distinct characteristics of these abnormalities in mtDNA may provide a new path for cancer therapy. Here we discuss a promising novel therapeutic strategy, using the sequence-specific properties of pyrrole-imidazole polyamide-triphenylphosphonium conjugates, against cancer for clearing abnormal mtDNA by reactivating mitochondrial quality control surveillance.}, }
@article {pmid34529715, year = {2021}, author = {Son, JH and Weiss, BL and Schneider, DI and Dera, KM and Gstöttenmayer, F and Opiro, R and Echodu, R and Saarman, NP and Attardo, GM and Onyango, M and Abd-Alla, AMM and Aksoy, S}, title = {Infection with endosymbiotic Spiroplasma disrupts tsetse (Glossina fuscipes fuscipes) metabolic and reproductive homeostasis.}, journal = {PLoS pathogens}, volume = {17}, number = {9}, pages = {e1009539}, pmid = {34529715}, issn = {1553-7374}, support = {D43 TW007391/TW/FIC NIH HHS/United States ; R01 AI139525/AI/NIAID NIH HHS/United States ; UL1 TR001863/TR/NCATS NIH HHS/United States ; }, mesh = {Animals ; Female ; Insect Vectors/*microbiology/*physiology ; Male ; *Spiroplasma ; Symbiosis/*physiology ; Tsetse Flies/*microbiology/*physiology ; }, abstract = {Tsetse flies (Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host's metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma, was recently discovered to reside within multiple tissues of field captured and laboratory colonized tsetse flies grouped in the Palpalis subgenera. In various arthropods, Spiroplasma induces reproductive abnormalities and pathogen protective phenotypes. In tsetse, Spiroplasma infections also induce a protective phenotype by enhancing the fly's resistance to infection with trypanosomes. However, the potential impact of Spiroplasma on tsetse's viviparous reproductive physiology remains unknown. Herein we employed high-throughput RNA sequencing and laboratory-based functional assays to better characterize the association between Spiroplasma and the metabolic and reproductive physiologies of G. fuscipes fuscipes (Gff), a prominent vector of human disease. Using field-captured Gff, we discovered that Spiroplasma infection induces changes of sex-biased gene expression in reproductive tissues that may be critical for tsetse's reproductive fitness. Using a Gff lab line composed of individuals heterogeneously infected with Spiroplasma, we observed that the bacterium and tsetse host compete for finite nutrients, which negatively impact female fecundity by increasing the length of intrauterine larval development. Additionally, we found that when males are infected with Spiroplasma, the motility of their sperm is compromised following transfer to the female spermatheca. As such, Spiroplasma infections appear to adversely impact male reproductive fitness by decreasing the competitiveness of their sperm. Finally, we determined that the bacterium is maternally transmitted to intrauterine larva at a high frequency, while paternal transmission was also noted in a small number of matings. Taken together, our findings indicate that Spiroplasma exerts a negative impact on tsetse fecundity, an outcome that could be exploited for reducing tsetse population size and thus disease transmission.}, }
@article {pmid34529074, year = {2022}, author = {Roeder, AHK and Otegui, MS and Dixit, R and Anderson, CT and Faulkner, C and Zhang, Y and Harrison, MJ and Kirchhelle, C and Goshima, G and Coate, JE and Doyle, JJ and Hamant, O and Sugimoto, K and Dolan, L and Meyer, H and Ehrhardt, DW and Boudaoud, A and Messina, C}, title = {Fifteen compelling open questions in plant cell biology.}, journal = {The Plant cell}, volume = {34}, number = {1}, pages = {72-102}, pmid = {34529074}, issn = {1532-298X}, support = {R01 GM134037/GM/NIGMS NIH HHS/United States ; R35 GM139552/GM/NIGMS NIH HHS/United States ; }, mesh = {Cell Biology ; Plant Cells/*physiology ; Plant Development ; *Plant Physiological Phenomena ; }, abstract = {As scientists, we are at least as excited about the open questions-the things we do not know-as the discoveries. Here, we asked 15 experts to describe the most compelling open questions in plant cell biology. These are their questions: How are organelle identity, domains, and boundaries maintained under the continuous flux of vesicle trafficking and membrane remodeling? Is the plant cortical microtubule cytoskeleton a mechanosensory apparatus? How are the cellular pathways of cell wall synthesis, assembly, modification, and integrity sensing linked in plants? Why do plasmodesmata open and close? Is there retrograde signaling from vacuoles to the nucleus? How do root cells accommodate fungal endosymbionts? What is the role of cell edges in plant morphogenesis? How is the cell division site determined? What are the emergent effects of polyploidy on the biology of the cell, and how are any such "rules" conditioned by cell type? Can mechanical forces trigger new cell fates in plants? How does a single differentiated somatic cell reprogram and gain pluripotency? How does polarity develop de-novo in isolated plant cells? What is the spectrum of cellular functions for membraneless organelles and intrinsically disordered proteins? How do plants deal with internal noise? How does order emerge in cells and propagate to organs and organisms from complex dynamical processes? We hope you find the discussions of these questions thought provoking and inspiring.}, }
@article {pmid34527601, year = {2021}, author = {Altinli, M and Schnettler, E and Sicard, M}, title = {Symbiotic Interactions Between Mosquitoes and Mosquito Viruses.}, journal = {Frontiers in cellular and infection microbiology}, volume = {11}, number = {}, pages = {694020}, pmid = {34527601}, issn = {2235-2988}, mesh = {Animals ; *Arboviruses ; *Culicidae ; Female ; Humans ; *Insect Viruses ; Metagenomics ; *Viruses ; }, abstract = {Mosquitoes not only transmit human and veterinary pathogens called arboviruses (arthropod-borne viruses) but also harbor mosquito-associated insect-specific viruses (mosquito viruses) that cannot infect vertebrates. In the past, studies investigating mosquito viruses mainly focused on highly pathogenic interactions that were easier to detect than those without visible symptoms. However, the recent advances in viral metagenomics have highlighted the abundance and diversity of viruses which do not generate mass mortality in host populations. Over the last decade, this has facilitated the rapid growth of virus discovery in mosquitoes. The circumstances around the discovery of mosquito viruses greatly affected how they have been studied so far. While earlier research mainly focused on the pathogenesis caused by DNA and some double-stranded RNA viruses during larval stages, more recently discovered single-stranded RNA mosquito viruses were heavily studied for their putative interference with arboviruses in female adults. Thus, many aspects of mosquito virus interactions with their hosts and host-microbiota are still unknown. In this context, considering mosquito viruses as endosymbionts can help to identify novel research areas, in particular in relation to their long-term interactions with their hosts (e.g. relationships during all life stages, the stability of the associations at evolutionary scales, transmission routes and virulence evolution) and the possible context-dependent range of interactions (i.e. beneficial to antagonistic). Here, we review the symbiotic interactions of mosquito viruses considering different aspects of their ecology, such as transmission, host specificity, host immune system and interactions with other symbionts within the host cellular arena. Finally, we highlight related research gaps in mosquito virus research.}, }
@article {pmid34525331, year = {2021}, author = {Zhong, Z and Zhong, T and Peng, Y and Zhou, X and Wang, Z and Tang, H and Wang, J}, title = {Symbiont-regulated serotonin biosynthesis modulates tick feeding activity.}, journal = {Cell host &amp; microbe}, volume = {29}, number = {10}, pages = {1545-1557.e4}, doi = {10.1016/j.chom.2021.08.011}, pmid = {34525331}, issn = {1934-6069}, mesh = {Animals ; Blood/parasitology ; Coxiella/*physiology ; Feeding Behavior ; Humans ; Serotonin/*biosynthesis ; *Symbiosis ; Ticks/*microbiology/*physiology ; Tryptophan/metabolism ; }, abstract = {Ticks are obligate hematophagous arthropods. Blood feeding ensures that ticks obtain nutrients essential for their survival, development, and reproduction while providing routes for pathogen transmission. However, the effectors that determine tick feeding activities remain poorly understood. Here, we demonstrate that reduced abundance of the symbiont Coxiella (CHI) in Haemaphysalis longicornis decreases blood intake. Providing tetracycline-treated ticks with the CHI-derived tryptophan precursor chorismate, tryptophan, or 5-hydroxytryptamine (5-HT; serotonin) restores the feeding defect. Mechanistically, CHI-derived chorismate increases tick 5-HT biosynthesis by stimulating the expression of aromatic amino acid decarboxylase (AAAD), which catalyzes the decarboxylation of 5-hydroxytryptophan (5-HTP) to 5-HT. The increased level of 5-HT in the synganglion and midgut promotes tick feeding. Inhibition of CHI chorismate biosynthesis by treating the colonized tick with the herbicide glyphosate suppresses blood-feeding behavior. Taken together, our results demonstrate an important function of the endosymbiont Coxiella in the regulation of tick 5-HT biosynthesis and feeding.}, }
@article {pmid34525260, year = {2022}, author = {Chen, F and Schenkel, M and Geuverink, E and van de Zande, L and Beukeboom, LW}, title = {Absence of complementary sex determination in two Leptopilina species (Figitidae, Hymenoptera) and a reconsideration of its incompatibility with endosymbiont-induced thelytoky.}, journal = {Insect science}, volume = {29}, number = {3}, pages = {900-914}, pmid = {34525260}, issn = {1744-7917}, mesh = {Animals ; Diploidy ; Female ; Haploidy ; *Hymenoptera/genetics/microbiology ; Male ; Parthenogenesis ; *Wasps/genetics/microbiology ; *Wolbachia/genetics ; }, abstract = {Complementary sex determination (CSD) is a widespread sex determination mechanism in haplodiploid Hymenoptera. Under CSD, sex is determined by the allelic state of one or multiple CSD loci. Heterozygosity at one or more loci leads to female development, whereas hemizygosity of haploid eggs and homozygosity of diploid eggs results in male development. Sexual (arrhenotokous) reproduction normally yields haploid male and diploid female offspring. Under asexual reproduction (thelytoky), diploidized unfertilized eggs develop into females. Thelytoky is often induced by bacterial endosymbionts that achieve egg diploidization by gamete duplication. As gamete duplication leads to complete homozygosity, endosymbiont-induced thelytokous reproduction is presumed to be incompatible with CSD, which relies on heterozygosity for female development. Previously, we excluded CSD in four Asobara (Braconidae) species and proposed a two-step mechanism for Wolbachia-induced thelytoky in Asobara japonica. Here, we conclusively reject CSD in two cynipid wasp species, Leptopilina heterotoma and Leptopilina clavipes. We further show that thelytoky in L. clavipes depends on Wolbachia titer but that diploidization and feminization steps cannot be separated, unlike in A. japonica. We discuss what these results reveal about the sex determination mechanism of L. clavipes and the presumed incompatibility between CSD and endosymbiont-induced thelytoky in the Hymenoptera.}, }
@article {pmid34521754, year = {2021}, author = {Jenkins, BH and Maguire, F and Leonard, G and Eaton, JD and West, S and Housden, BE and Milner, DS and Richards, TA}, title = {Emergent RNA-RNA interactions can promote stability in a facultative phototrophic endosymbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {38}, pages = {}, pmid = {34521754}, issn = {1091-6490}, support = {/WT_/Wellcome Trust/United Kingdom ; WT107791/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Chlorella/genetics ; Chloroplasts/genetics ; Eukaryota/genetics ; Paramecium/genetics ; Phototrophic Processes/*genetics ; Plastids/genetics ; RNA/*genetics ; RNA Interference/physiology ; Symbiosis/*genetics ; }, abstract = {Eukaryote-eukaryote endosymbiosis was responsible for the spread of chloroplast (plastid) organelles. Stability is required for the metabolic and genetic integration that drives the establishment of new organelles, yet the mechanisms that act to stabilize emergent endosymbioses-between two fundamentally selfish biological organisms-are unclear. Theory suggests that enforcement mechanisms, which punish misbehavior, may act to stabilize such interactions by resolving conflict. However, how such mechanisms can emerge in a facultative endosymbiosis has yet to be explored. Here, we propose that endosymbiont-host RNA-RNA interactions, arising from digestion of the endosymbiont population, can result in a cost to host growth for breakdown of the endosymbiosis. Using the model facultative endosymbiosis between Paramecium bursaria and Chlorella spp., we demonstrate that this mechanism is dependent on the host RNA-interference (RNAi) system. We reveal through small RNA (sRNA) sequencing that endosymbiont-derived messenger RNA (mRNA) released upon endosymbiont digestion can be processed by the host RNAi system into 23-nt sRNA. We predict multiple regions of shared sequence identity between endosymbiont and host mRNA, and demonstrate through delivery of synthetic endosymbiont sRNA that exposure to these regions can knock down expression of complementary host genes, resulting in a cost to host growth. This process of host gene knockdown in response to endosymbiont-derived RNA processing by host RNAi factors, which we term "RNAi collisions," represents a mechanism that can promote stability in a facultative eukaryote-eukaryote endosymbiosis. Specifically, by imposing a cost for breakdown of the endosymbiosis, endosymbiont-host RNA-RNA interactions may drive maintenance of the symbiosis across fluctuating ecological conditions.}, }
@article {pmid34518054, year = {2021}, author = {Voolstra, CR and Aranda, M and Zhan, Y and Dekker, J}, title = {Symbiodinium microadriaticum (coral microalgal endosymbiont).}, journal = {Trends in genetics : TIG}, volume = {37}, number = {11}, pages = {1044-1045}, doi = {10.1016/j.tig.2021.08.008}, pmid = {34518054}, issn = {0168-9525}, support = {R01 HG003143/HG/NHGRI NIH HHS/United States ; }, mesh = {Animals ; *Anthozoa ; Coral Reefs ; *Dinoflagellida/genetics ; *Microalgae/genetics ; Symbiosis/genetics ; }, }
@article {pmid34513731, year = {2021}, author = {Salazar, MM and Pupo, MT and Brown, AMV}, title = {Co-Occurrence of Viruses, Plant Pathogens, and Symbionts in an Underexplored Hemipteran Clade.}, journal = {Frontiers in cellular and infection microbiology}, volume = {11}, number = {}, pages = {715998}, pmid = {34513731}, issn = {2235-2988}, mesh = {Animals ; *Aphids ; *Bacteriophages ; Phylogeny ; *Plant Viruses ; Symbiosis ; }, abstract = {Interactions between insect symbionts and plant pathogens are dynamic and complex, sometimes involving direct antagonism or synergy and sometimes involving ecological and evolutionary leaps, as insect symbionts transmit through plant tissues or plant pathogens transition to become insect symbionts. Hemipterans such as aphids, whiteflies, psyllids, leafhoppers, and planthoppers are well-studied plant pests that host diverse symbionts and vector plant pathogens. The related hemipteran treehoppers (family Membracidae) are less well-studied but offer a potentially new and diverse array of symbionts and plant pathogenic interactions through their distinct woody plant hosts and ecological interactions with diverse tending hymenopteran taxa. To explore membracid symbiont-pathogen diversity and co-occurrence, this study performed shotgun metagenomic sequencing on 20 samples (16 species) of treehopper, and characterized putative symbionts and pathogens using a combination of rapid blast database searches and phylogenetic analysis of assembled scaffolds and correlation analysis. Among the 8.7 billion base pairs of scaffolds assembled were matches to 9 potential plant pathogens, 12 potential primary and secondary insect endosymbionts, numerous bacteriophages, and other viruses, entomopathogens, and fungi. Notable discoveries include a divergent Brenneria plant pathogen-like organism, several bee-like Bombella and Asaia strains, novel strains of Arsenophonus-like and Sodalis-like symbionts, Ralstonia sp. and Ralstonia-type phages, Serratia sp., and APSE-type phages and bracoviruses. There were several short Phytoplasma and Spiroplasma matches, but there was no indication of plant viruses in these data. Clusters of positively correlated microbes such as yeast-like symbionts and Ralstonia, viruses and Serratia, and APSE phage with parasitoid-type bracoviruses suggest directions for future analyses. Together, results indicate membracids offer a rich palette for future study of symbiont-plant pathogen interactions.}, }
@article {pmid34512702, year = {2021}, author = {Aroney, STN and Poole, PS and Sánchez-Cañizares, C}, title = {Rhizobial Chemotaxis and Motility Systems at Work in the Soil.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {725338}, pmid = {34512702}, issn = {1664-462X}, abstract = {Bacteria navigate their way often as individual cells through their chemical and biological environment in aqueous medium or across solid surfaces. They swim when starved or in response to physical and chemical stimuli. Flagella-driven chemotaxis in bacteria has emerged as a paradigm for both signal transduction and cellular decision-making. By altering motility, bacteria swim toward nutrient-rich environments, movement modulated by their chemotaxis systems with the addition of pili for surface movement. The numbers and types of chemoreceptors reflect the bacterial niche and lifestyle, with those adapted to complex environments having diverse metabolic capabilities, encoding far more chemoreceptors in their genomes. The Alpha-proteobacteria typify the latter case, with soil bacteria such as rhizobia, endosymbionts of legume plants, where motility and chemotaxis are essential for competitive symbiosis initiation, among other processes. This review describes the current knowledge of motility and chemotaxis in six model soil bacteria: Sinorhizobium meliloti, Agrobacterium fabacearum, Rhizobium leguminosarum, Azorhizobium caulinodans, Azospirillum brasilense, and Bradyrhizobium diazoefficiens. Although motility and chemotaxis systems have a conserved core, rhizobia possess several modifications that optimize their movements in soil and root surface environments. The soil provides a unique challenge for microbial mobility, since water pathways through particles are not always continuous, especially in drier conditions. The effectiveness of symbiont inoculants in a field context relies on their mobility and dispersal through the soil, often assisted by water percolation or macroorganism movement or networks. Thus, this review summarizes the factors that make it essential to consider and test rhizobial motility and chemotaxis for any potential inoculant.}, }
@article {pmid34509839, year = {2022}, author = {Sun, Y and Wang, M and Zhong, Z and Chen, H and Wang, H and Zhou, L and Cao, L and Fu, L and Zhang, H and Lian, C and Sun, S and Li, C}, title = {Adaption to hydrogen sulfide-rich environments: Strategies for active detoxification in deep-sea symbiotic mussels, Gigantidas platifrons.}, journal = {The Science of the total environment}, volume = {804}, number = {}, pages = {150054}, doi = {10.1016/j.scitotenv.2021.150054}, pmid = {34509839}, issn = {1879-1026}, mesh = {Animals ; Bacteria ; *Hydrogen Sulfide ; *Hydrothermal Vents ; *Mytilidae ; Symbiosis ; }, abstract = {The deep-sea mussel Gigantidas platifrons is a representative species that relies on nutrition provided by chemoautotrophic endosymbiotic bacteria to survive in both hydrothermal vent and methane seep environments. However, vent and seep habitats have distinct geochemical features, with vents being more harsh than seeps because of abundant toxic chemical substances, particularly hydrogen sulfide (H2S). Until now, the adaptive strategies of G. platifrons in a heterogeneous environment and their sulfide detoxification mechanisms are still unclear. Herein, we conducted 16S rDNA sequencing and metatranscriptome sequencing of G. platifrons collected from a methane seep at Formosa Ridge in the South China Sea and a hydrothermal vent at Iheya North Knoll in the Mid-Okinawa Trough to provide a model for understanding environmental adaption and sulfide detoxification mechanisms, and a three-day laboratory controlled Na2S stress experiment to test the transcriptomic responses under sulfide stress. The results revealed the active detoxification of sulfide in G. platifrons gills. First, epibiotic Campylobacterota bacteria were more abundant in vent mussels and contributed to environmental adaptation by active oxidation of extracellular H2S. Notably, a key sulfide-oxidizing gene, sulfide:quinone oxidoreductase (sqr), derived from the methanotrophic endosymbiont, was significantly upregulated in vent mussels, indicating the oxidization of intracellular sulfide by the endosymbiont. In addition, transcriptomic comparison further suggested that genes involved in oxidative phosphorylation and mitochondrial sulfide oxidization pathway played important roles in the sulfide tolerance of the host mussels. Moreover, transcriptomic analysis of Na2S stressed mussels confirmed the upregulation of oxidative phosphorylation and sulfide oxidization genes in response to sulfide exposure. Overall, this study provided a systematic transcriptional analysis of both the active bacterial community members and the host mussels, suggesting that the epibionts, endosymbionts, and mussel host collaborated on sulfide detoxification from extracellular to intracellular space to adapt to harsh H2S-rich environments.}, }
@article {pmid34506949, year = {2022}, author = {Zhang, T and Vd'ačný, P}, title = {Multiple independent losses of cell mouth in phylogenetically distant endosymbiotic lineages of oligohymenophorean ciliates: A lesson from Clausilocola.}, journal = {Molecular phylogenetics and evolution}, volume = {166}, number = {}, pages = {107310}, doi = {10.1016/j.ympev.2021.107310}, pmid = {34506949}, issn = {1095-9513}, mesh = {*Ciliophora/genetics ; Mouth ; *Oligohymenophorea ; Phylogeny ; Symbiosis/genetics ; }, abstract = {The cell mouth is a property of the vast majority of free-living and endosymbiotic/epibiotic ciliates of the class Oligohymenophorea. Cytostome, however, naturally absents in the whole endosymbiotic subclass Astomatia and was naturally or experimentally lost in a few members of the subclass Hymenostomatia. This poses a question of how homoplastic might be the lack of oral structures in the oligohymenophorean evolution. To address this question, we used two mitochondrial genes, five nuclear markers, and detailed morphological data from an enigmatic mouthless ciliate, Clausilocola apostropha, which we re-discovered after more than half of a century. According to the present phylogenetic analyses, astomy evolved at least three times independently and in different time frames of the oligohymenophorean phylogeny, ranging from the Paleozoic to the Cenozoic period. Mouthless endosymbionts inhabiting mollusks (represented by Clausilocola), planarians (Haptophrya), and annelids ('core' astomes) never clustered together. Haptophrya grouped with the scuticociliate genus Conchophthirus, 'core' astomes were placed in a sister position to the scuticociliate orders Philasterida and Pleuronematida, and Clausilocola was robustly nested within the hymenostome family Tetrahymenidae. The tetrahymenid origin of Clausilocola is further corroborated by the existence of mouthless Tetrahymena mutants and the huge phenotypic plasticity in the cytostome size in tetrahymenids.}, }
@article {pmid34504301, year = {2021}, author = {Kiefer, JST and Batsukh, S and Bauer, E and Hirota, B and Weiss, B and Wierz, JC and Fukatsu, T and Kaltenpoth, M and Engl, T}, title = {Author Correction: Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis.}, journal = {Communications biology}, volume = {4}, number = {1}, pages = {1079}, pmid = {34504301}, issn = {2399-3642}, }
@article {pmid34504005, year = {2021}, author = {Büttner, H and Niehs, SP and Vandelannoote, K and Cseresnyés, Z and Dose, B and Richter, I and Gerst, R and Figge, MT and Stinear, TP and Pidot, SJ and Hertweck, C}, title = {Bacterial endosymbionts protect beneficial soil fungus from nematode attack.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {37}, pages = {}, pmid = {34504005}, issn = {1091-6490}, mesh = {Animals ; Anthelmintics/*pharmacology ; Burkholderiaceae/*physiology ; Genomics ; Lactones/*pharmacology ; Metabolic Networks and Pathways ; *Metagenome ; Mortierella/drug effects/*physiology ; Nematoda/*drug effects/pathogenicity ; Peptide Synthases/genetics/metabolism ; Phylogeny ; Soil Microbiology ; *Symbiosis ; }, abstract = {Fungi of the genus Mortierella occur ubiquitously in soils where they play pivotal roles in carbon cycling, xenobiont degradation, and promoting plant growth. These important fungi are, however, threatened by micropredators such as fungivorous nematodes, and yet little is known about their protective tactics. We report that Mortierella verticillata NRRL 6337 harbors a bacterial endosymbiont that efficiently shields its host from nematode attacks with anthelmintic metabolites. Microscopic investigation and 16S ribosomal DNA analysis revealed that a previously overlooked bacterial symbiont belonging to the genus Mycoavidus dwells in M. verticillata hyphae. Metabolic profiling of the wild-type fungus and a symbiont-free strain obtained by antibiotic treatment as well as genome analyses revealed that highly cytotoxic macrolactones (CJ-12,950 and CJ-13,357, syn necroxime C and D), initially thought to be metabolites of the soil-inhabiting fungus, are actually biosynthesized by the endosymbiont. According to comparative genomics, the symbiont belongs to a new species (Candidatus Mycoavidus necroximicus) with 12% of its 2.2 Mb genome dedicated to natural product biosynthesis, including the modular polyketide-nonribosomal peptide synthetase for necroxime assembly. Using Caenorhabditis elegans and the fungivorous nematode Aphelenchus avenae as test strains, we show that necroximes exert highly potent anthelmintic activities. Effective host protection was demonstrated in cocultures of nematodes with symbiotic and chemically complemented aposymbiotic fungal strains. Image analysis and mathematical quantification of nematode movement enabled evaluation of the potency. Our work describes a relevant role for endofungal bacteria in protecting fungi against mycophagous nematodes.}, }
@article {pmid34495683, year = {2021}, author = {Li, TP and Zha, SS and Zhou, CY and Xia, X and Hoffmann, AA and Hong, XY}, title = {Two Newly Introduced Wolbachia Endosymbionts Induce Cell Host Differences in Competitiveness and Metabolic Responses.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {22}, pages = {e0147921}, pmid = {34495683}, issn = {1098-5336}, mesh = {Aedes/microbiology ; Animals ; Cell Line ; Hemiptera/*microbiology ; *Symbiosis ; *Wolbachia/classification/growth &amp; development ; }, abstract = {Wolbachia endosymbionts can induce multiple reproductive manipulations in their hosts, with cytoplasmic incompatibility (CI) being one of the most common manipulations. Two important agricultural pests, the white-backed planthopper (Sogatella furcifera) and the brown planthopper (Nilaparvata lugens), are usually infected with CI-inducing Wolbachia strain wFur and non-CI-inducing Wolbachia strain wLug, respectively. The biological effects of these infections when present in a host cell are unknown. Here, we introduced the two Wolbachia strains into an Aedes albopictus cell line to stably establish a wFur-infected cell line (WFI) and a wLug-infected cell line (WLI). In a mixed culture, WFI cells were completely replaced by WLI cells, pointing to a stronger competitiveness of the WLI cell line. We found that infection by both Wolbachia strains reduced cell growth rates, but WLI had a higher cell growth rate than WFI, and this difference in cell growth rate combined with possible Wolbachia differences in diffusivity may have affected cell competitiveness. By examining gene expression and metabolites in the two lines, we found that some genes and key metabolites responded to differences in cell competitiveness. These results point to potential mechanisms that could contribute to the relative performance of hosts infected by these strains and also highlight the substantial impact of a non-CI Wolbachia on metabolism, which may in turn influence the fitness of its native host. IMPORTANCEWolbachia transinfection in insects can be used to suppress pests and block virus transmission. We stably introduced two Wolbachia strains from rice planthoppers into cell lines of an important arbovirus mosquito vector, Aedes albopictus. The levels of competitiveness of host cells from the lines infected by the two Wolbachia strains were different, as were metabolic responses of the cell lines. These results suggest potential metabolic effects of Wolbachia on native hosts that could be exploited when they are transinfected into novel hosts for pest control.}, }
@article {pmid34488648, year = {2021}, author = {Prazeres, M and Roberts, TE and Ramadhani, SF and Doo, SS and Schmidt, C and Stuhr, M and Renema, W}, title = {Diversity and flexibility of algal symbiont community in globally distributed larger benthic foraminifera of the genus Amphistegina.}, journal = {BMC microbiology}, volume = {21}, number = {1}, pages = {243}, pmid = {34488648}, issn = {1471-2180}, mesh = {Coral Reefs ; DNA Barcoding, Taxonomic ; Diatoms/genetics ; *Ecosystem ; Foraminifera/classification/*genetics ; *Genetic Variation ; High-Throughput Nucleotide Sequencing ; Oceans and Seas ; Phylogeny ; *Symbiosis ; }, abstract = {BACKGROUND: Understanding the specificity and flexibility of the algal symbiosis-host association is fundamental for predicting how species occupy a diverse range of habitats. Here we assessed the algal symbiosis diversity of three species of larger benthic foraminifera from the genus Amphistegina and investigated the role of habitat and species identity in shaping the associated algal community.<br><br>RESULTS: We used next-generation sequencing to identify the associated algal community, and DNA barcoding to identify the diatom endosymbionts associated with species of A. lobifera, A. lessonii, and A. radiata, collected from shallow habitats (<&#x2009;15&#x2009;m) in 16 sites, ranging from the Mediterranean Sea to French Polynesia. Next-generation sequencing results showed the consistent presence of Ochrophyta as the main algal phylum associated with all species and sites analysed. A significant proportion of phylotypes were classified as Chlorophyta and Myzozoa. We uncovered unprecedented diversity of algal phylotypes found in low abundance, especially of the class Bacillariophyta (i.e., diatoms). We found a significant influence of sites rather than host identity in shaping algal communities in all species. DNA barcoding revealed the consistent presence of phylotypes classified within the order Fragilariales as the diatoms associated with A. lobifera and A. lessonii, while A. radiata specimens host predominately diatoms of the order Triceratiales.<br><br>CONCLUSIONS: We show that local habitat is the main factor influencing the overall composition of the algal symbiont community. However, host identity and the phylogenetic relationship among hosts is relevant in shaping the specific endosymbiont diatom community, suggesting that the relationship between diatom endosymbiont and hosts plays a crucial role in the evolutionary history of the genus Amphistegina. The capacity of Amphistegina species to associate with a diverse array of diatoms, and possibly other algal groups, likely underpins the ecological success of these crucial calcifying organisms across their extensive geographic range.}, }
@article {pmid34488624, year = {2021}, author = {Urban, JM and Foulk, MS and Bliss, JE and Coleman, CM and Lu, N and Mazloom, R and Brown, SJ and Spradling, AC and Gerbi, SA}, title = {High contiguity de novo genome assembly and DNA modification analyses for the fungus fly, Sciara coprophila, using single-molecule sequencing.}, journal = {BMC genomics}, volume = {22}, number = {1}, pages = {643}, pmid = {34488624}, issn = {1471-2164}, support = {P20 GM103418/GM/NIGMS NIH HHS/United States ; T32-GM 007601/GM/NIGMS NIH HHS/United States ; GM121455/GM/NIGMS NIH HHS/United States ; }, mesh = {DNA ; Female ; Fungi ; *High-Throughput Nucleotide Sequencing ; Humans ; Male ; Sequence Analysis, DNA ; *X Chromosome ; }, abstract = {BACKGROUND: The lower Dipteran fungus fly, Sciara coprophila, has many unique biological features that challenge the rule of genome DNA constancy. For example, Sciara undergoes paternal chromosome elimination and maternal X chromosome nondisjunction during spermatogenesis, paternal X elimination during embryogenesis, intrachromosomal DNA amplification of DNA puff loci during larval development, and germline-limited chromosome elimination from all somatic cells. Paternal chromosome elimination in Sciara was the first observation of imprinting, though the mechanism remains a mystery. Here, we present the first draft genome sequence for Sciara coprophila to take a large step forward in addressing these features.<br><br>RESULTS: We assembled the Sciara genome using PacBio, Nanopore, and Illumina sequencing. To find an optimal assembly using these datasets, we generated 44 short-read and 50 long-read assemblies. We ranked assemblies using 27 metrics assessing contiguity, gene content, and dataset concordance. The highest-ranking assemblies were scaffolded using BioNano optical maps. RNA-seq datasets from multiple life stages and both sexes facilitated genome annotation. A set of 66 metrics was used to select the first draft assembly for Sciara. Nearly half of the Sciara genome sequence was anchored into chromosomes, and all scaffolds were classified as X-linked or autosomal by coverage.<br><br>CONCLUSIONS: We determined that X-linked genes in Sciara males undergo dosage compensation. An entire bacterial genome from the Rickettsia genus, a group known to be endosymbionts in insects, was co-assembled with the Sciara genome, opening the possibility that Rickettsia may function in sex determination in Sciara. Finally, the signal level of the PacBio and Nanopore data support the presence of cytosine and adenine modifications in the Sciara genome, consistent with a possible role in imprinting.}, }
@article {pmid34479645, year = {2021}, author = {Zhou, K and Xu, Y and Zhang, R and Qian, PY}, title = {Arms race in a cell: genomic, transcriptomic, and proteomic insights into intracellular phage-bacteria interplay in deep-sea snail holobionts.}, journal = {Microbiome}, volume = {9}, number = {1}, pages = {182}, pmid = {34479645}, issn = {2049-2618}, mesh = {Animals ; Bacteria/genetics ; *Bacteriophages/genetics ; Genomics ; Proteomics ; Snails ; Transcriptome/genetics ; }, abstract = {BACKGROUND: Deep-sea animals in hydrothermal vents often form endosymbioses with chemosynthetic bacteria. Endosymbionts serve essential biochemical and ecological functions, but the prokaryotic viruses (phages) that determine their fate are unknown.<br><br>RESULTS: We conducted metagenomic analysis of a deep-sea vent snail. We assembled four genome bins for Caudovirales phages that had developed dual endosymbiosis with sulphur-oxidising bacteria (SOB) and methane-oxidising bacteria (MOB). Clustered regularly interspaced short palindromic repeat (CRISPR) spacer mapping, genome comparison, and transcriptomic profiling revealed that phages Bin1, Bin2, and Bin4 infected SOB and MOB. The observation of prophages in the snail endosymbionts and expression of the phage integrase gene suggested the presence of lysogenic infection, and the expression of phage structural protein and lysozyme genes indicated active lytic infection. Furthermore, SOB and MOB appear to employ adaptive CRISPR-Cas systems to target phage DNA. Additional expressed defence systems, such as innate restriction-modification systems and dormancy-inducing toxin-antitoxin systems, may co-function and form multiple lines for anti-viral defence. To counter host defence, phages Bin1, Bin2, and Bin3 appear to have evolved anti-restriction mechanisms and expressed methyltransferase genes that potentially counterbalance host restriction activity. In addition, the high-level expression of the auxiliary metabolic genes narGH, which encode nitrate reductase subunits, may promote ATP production, thereby benefiting phage DNA packaging for replication.<br><br>CONCLUSIONS: This study provides new insights into phage-bacteria interplay in intracellular environments of a deep-sea vent snail. Video Abstract.}, }
@article {pmid34475861, year = {2021}, author = {Mosquera, KD and Martinez Villegas, LE and Pidot, SJ and Sharif, C and Klimpel, S and Stinear, TP and Moreira, LA and Tobias, NJ and Lorenzo, MG}, title = {Multi-Omic Analysis of Symbiotic Bacteria Associated With Aedes aegypti Breeding Sites.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {703711}, pmid = {34475861}, issn = {1664-302X}, abstract = {Mosquito breeding sites are complex aquatic environments with wide microbial diversity and physicochemical parameters that can change over time during the development of immature insect stages. Changes in biotic and abiotic conditions in water can alter life-history traits of adult mosquitos but this area remains understudied. Here, using microbial genomic and metabolomics analyses, we explored the metabolites associated with Aedes aegypti breeding sites as well as the potential contribution of Klebsiella sp., symbiotic bacteria highly associated with mosquitoes. We sought to address whether breeding sites have a signature metabolic profile and understand the metabolite contribution of the bacteria in the aquatic niches where Ae. aegypti larvae develop. An analysis of 32 mosquito-associated bacterial genomes, including Klebsiella, allowed us to identify gene clusters involved in primary metabolic pathways. From them, we inferred metabolites that could impact larval development (e.g., spermidine), as well as influence the quality assessment of a breeding site by a gravid female (e.g., putrescine), if produced by bacteria in the water. We also detected significant variance in metabolite presence profiles between water samples representing a decoupled oviposition event (oviposition by single females and manually deposited eggs) versus a control where no mosquito interactions occurred (PERMANOVA: p < 0.05; R [2] = 24.64% and R [2] = 30.07%). Five Klebsiella metabolites were exclusively linked to water samples where oviposition and development occurred. These data suggest metabolomics can be applied to identify compounds potentially used by female Ae. aegypti to evaluate the quality of a breeding site. Elucidating the physiological mechanisms by which the females could integrate these sensory cues while ovipositing constitutes a growing field of interest, which could benefit from a more depurated list of candidate molecules.}, }
@article {pmid34474788, year = {2021}, author = {Krishnamoorthy, P and Sudhagar, S and Goudar, AL and Jacob, SS and Suresh, KP}, title = {Molecular survey and phylogenetic analysis of tick-borne pathogens in ticks infesting cattle from two South Indian states.}, journal = {Veterinary parasitology, regional studies and reports}, volume = {25}, number = {}, pages = {100595}, doi = {10.1016/j.vprsr.2021.100595}, pmid = {34474788}, issn = {2405-9390}, mesh = {Animals ; Cattle ; *Cattle Diseases/epidemiology/microbiology ; India/epidemiology ; Phylogeny ; *Rhipicephalus/microbiology ; *Tick Infestations/epidemiology/veterinary ; *Tick-Borne Diseases/epidemiology/microbiology/veterinary ; }, abstract = {In this study, the molecular survey of cattle ticks and tick-borne pathogens in various agroclimatic zones in Karnataka and Kerala states, India, and phylogenetic analysis of gene sequences were accomplished. Overall, 240 pooled tick DNA samples from two states were used for the identification of three tick genera and nine tick-borne pathogens by using the PCR method and sequencing. The distribution of Haemaphysalis (Ha.), Hyalomma (Hy.), and Rhipicephalus (R.) species were 5.0, 17.5, and 65.8% in Karnataka and 5.8, 11.7, and 65.0% in Kerala, respectively. The prevalence of Anaplasma marginale, Babesia bovis, Rickettsia species, and Trypanosoma evansi was 8.3, 0.8, 6.7, and 0.0% in Karnataka and 14.2, 0.0, 8.3, and 8.3% in Kerala, respectively. The pooled tick DNA samples were negative for Bartonella species, Borrelia species, Coxiella burnetti, Pasteurella multocida, and Theileria species. The season-wise analysis revealed a high occurrence of Ha. species in all seasons except for post-monsoon, Hy. and Rhipicephalus species in monsoon season in Karnataka, and all three tick genera were present in monsoon season in Kerala. The sequence analysis of mitochondrial cytochrome oxidase subunit 1 gene facilitated the identification of tick species namely, Ha. bispinosa, Ha. japonica, Hy. excavatum, R. annulatus, R. decoloratus, R. microplus, and R. sanguineus. The Rhipicephalus species was a major tick in these two states, and Rickettsia endosymbiont and Trypanosoma evansi in tick were detected in this study. This study represents the first report about the presence of Rickettsia massiliae in Ha. bispinosa in Karnataka and Trypanosoma evansi in R. species in Kerala. Phylogenetic analysis revealed sequence homology between the different isolates from India and neighbouring countries. Thus, the study provides key information on the distribution of ticks and tick-borne pathogens of cattle in Karnataka and Kerala, which will aid in developing and strategizing effective control measures.}, }
@article {pmid34470970, year = {2022}, author = {Sasaki, T and Moi, ML and Saito, K and Isawa, H and Takasaki, T and Sawabe, K}, title = {Aedes albopictus Strain and Dengue Virus Serotype in the Dengue Fever Outbreaks in Japan: Implications of Wolbachia Infection.}, journal = {Japanese journal of infectious diseases}, volume = {75}, number = {2}, pages = {140-143}, doi = {10.7883/yoken.JJID.2021.376}, pmid = {34470970}, issn = {1884-2836}, mesh = {*Aedes/genetics/virology ; Anaplasmataceae Infections/microbiology/virology ; Animals ; *Dengue/epidemiology/immunology/virology ; *Dengue Virus/genetics/immunology ; *Disease Outbreaks ; Disease Susceptibility ; Japan/epidemiology ; Serogroup ; Symbiosis ; *Wolbachia/genetics/virology ; }, abstract = {From August 27 to October 15, 2014, a dengue fever outbreak with 158 autochthonous cases occurred after nearly 70 years of no reports of autochthonous cases in Japan. The most competent mosquito vector for dengue virus (DENV) transmission in Japan is Aedes albopictus. Since A. albopictus is widely distributed throughout Japan, we examined the susceptibility of this species to infection by DENV and the relationship of the endosymbiont Wolbachia (wAlbA and wAlbB) with susceptibility to DENV. The A. albopictus YYG strain, collected from the Yoyogi Park in 2014, the epicenter of the dengue fever outbreak, was found to have lower susceptibility to DENV 1 and 3 than that of the indigenous Japanese strains A. albopictus EBN 201808 (F1 from the field) and A. albopictus ISG 201603. Furthermore, the A. albopictus EBN 201808 strain showed the same susceptibility to DENV3 as the A. albopictus ISG 201603tet strain (Wolbachia-free). Susceptibility to DENV3 was not related to Wolbachia strains wAlbA or wAlbB in the A. albopictus ISG 201603 strain.}, }
@article {pmid34466651, year = {2021}, author = {Pupić-Bakrač, A and Pupić-Bakrač, J and Beck, A and Jurković, D and Polkinghorne, A and Beck, R}, title = {Dirofilaria repens microfilaremia in humans: Case description and literature review.}, journal = {One health (Amsterdam, Netherlands)}, volume = {13}, number = {}, pages = {100306}, pmid = {34466651}, issn = {2352-7714}, abstract = {INTRODUCTION: Dirofilaria repens is a vector-borne filaroid helminth of carnivorous animals, primarily domesticated dogs. Humans are considered to be accidental hosts in which D. repens rarely reach sexual maturity but induce local inflammation, mainly in subcutaneous and ocular tissues.<br><br>METHODS: In the current study, we present the detection of multiple adults of D. repens, endosymbiont Wolbachia sp. and microfilariae by molecular analysis in peripheral tissues and bloodstream of a human host. A subsequent meta-analysis of published literature identified 21 cases of human infection with adult D. repens producing microfilariae.<br><br>RESULTS: Within the study population, there were 13 (59.09%) males, eight (36.36%) females and, in one (4.55%) case, sex was not reported. A total of 11 (50.00%) cases had subcutaneous dirofilariasis, six (27.27%) had ocular dirofiliariasis, with single cases (4.55% each) of genital, mammary, lymphatic and a combination of subcutaneous and pulmonary dirofilariasis described. In one (4.55%) case, the primary anatomical site of adult D. repens could not be found. D. repens microfilariae were detected in the local tissue (local microfilariasis) in 11 (50.00%) cases and the peripheral blood (microfilaremia) in 11 (50.50%) cases. Final identification of D. repens microfilariae was based on morphological detection in 14 (63.64%) cases, and molecular detection in eight (36.36%) cases.<br><br>CONCLUSION: The results of this study suggest that humans may act as a final host for D. repens, however its role as a source of D. repens infection is less clear.}, }
@article {pmid34463330, year = {2021}, author = {Álvarez-Lagazzi, AP and Cabrera, N and Francis, F and Ramírez, CC}, title = {Bacillus subtilis (Bacillales, Bacillaceae) Spores Affect Survival and Population Growth in the Grain Aphid Sitobion avenae (Hemiptera, Aphididae) in Relation to the Presence of the Facultative Bacterial Endosymbiont Regiella insecticola (Enterobacteriales, Enterobacteriaceae).}, journal = {Journal of economic entomology}, volume = {114}, number = {5}, pages = {2043-2050}, doi = {10.1093/jee/toab164}, pmid = {34463330}, issn = {1938-291X}, mesh = {Animals ; *Aphids ; *Bacillaceae ; *Bacillales ; Bacillus subtilis ; Enterobacteriaceae ; Population Growth ; Spores, Bacterial ; Symbiosis ; }, abstract = {The grain aphid Sitobion avenae (Fabricius) is one of the most important cereal pests, damaging crops through sap sucking and virus transmission. Sitobion avenae harbors the secondary endosymbiont Regiella insecticola, which is highly prevalent in populations in south-central Chile and other regions of the world. In order to develop ecological alternatives for biological control, we studied the effect of applying the spores of a strain of the bacterium Bacillus subtilis on the survival and fecundity of the most prevalent genotype of S. avenae in central Chile. The strain selected was one that in previous studies had shown the ability to outcompete other bacteria. Using clones of this aphid genotype infected and uninfected with R. insecticola, we found that applying B. subtilis spores through artificial diets and spraying on leaves decreased both adult survival and nymph production. The detection of spores within the aphid body was negatively correlated with nymph production and was lower in the presence of R. insecticola when applied in diets. B. subtilis spores applied on leaves reduced the number of aphids, an effect that was stronger on aphids harboring R. insecticola. A possible interaction between endosymbiotic bacteria and bacterial antagonists within the aphid body is discussed.}, }
@article {pmid34455644, year = {2022}, author = {Bruzzese, DJ and Schuler, H and Wolfe, TM and Glover, MM and Mastroni, JV and Doellman, MM and Tait, C and Yee, WL and Rull, J and Aluja, M and Hood, GR and Goughnour, RB and Stauffer, C and Nosil, P and Feder, JL}, title = {Testing the potential contribution of Wolbachia to speciation when cytoplasmic incompatibility becomes associated with host-related reproductive isolation.}, journal = {Molecular ecology}, volume = {31}, number = {10}, pages = {2935-2950}, pmid = {34455644}, issn = {1365-294X}, mesh = {Animals ; Cytoplasm/genetics ; DNA, Mitochondrial/genetics ; Drosophila/genetics ; Male ; Reproductive Isolation ; *Tephritidae/genetics ; *Wolbachia/genetics ; }, abstract = {Endosymbiont-induced cytoplasmic incompatibility (CI) may play an important role in arthropod speciation. However, whether CI consistently becomes associated or coupled with other host-related forms of reproductive isolation (RI) to impede the transfer of endosymbionts between hybridizing populations and further the divergence process remains an open question. Here, we show that varying degrees of pre- and postmating RI exist among allopatric populations of two interbreeding cherry-infesting tephritid fruit flies (Rhagoletis cingulata and R. indifferens) across North America. These flies display allochronic and sexual isolation among populations, as well as unidirectional reductions in egg hatch in hybrid crosses involving southwestern USA males. All populations are infected by a Wolbachia strain, wCin2, whereas a second strain, wCin3, only co-infects flies from the southwest USA and Mexico. Strain wCin3 is associated with a unique mitochondrial DNA haplotype and unidirectional postmating RI, implicating the strain as the cause of CI. When coupled with nonendosymbiont RI barriers, we estimate the strength of CI associated with wCin3 would not prevent the strain from introgressing from infected southwestern to uninfected populations elsewhere in the USA if populations were to come into secondary contact and hybridize. In contrast, cytoplasmic-nuclear coupling may impede the transfer of wCin3 if Mexican and USA populations were to come into contact. We discuss our results in the context of the general paucity of examples demonstrating stable Wolbachia hybrid zones and whether the spread of Wolbachia among taxa can be constrained in natural hybrid zones long enough for the endosymbiont to participate in speciation.}, }
@article {pmid34451405, year = {2021}, author = {Kisten, D and Brinkerhoff, J and Tshilwane, SI and Mukaratirwa, S}, title = {A Pilot Study on the Microbiome of Amblyomma hebraeum Tick Stages Infected and Non-Infected with Rickettsia africae.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {8}, pages = {}, pmid = {34451405}, issn = {2076-0817}, abstract = {Variation in tick microbiota may affect pathogen acquisition and transmission but for many vector species, including Amblyomma hebraeum, components and determinants of the microbiome are unidentified. This pilot study aimed to determine baseline microbial community within A. hebraeum nymphs infected- and non-infected with Rickettsia africae from the environment, and within adult ticks infected- and non-infected with R. africae collected from cattle sampled from two locations in the Eastern Cape province of South Africa. Adult A. hebraeum ticks (N = 13) and A. hebraeum nymph (N = 15) preliminary screened for R. africae were randomly selected and subjected to Illumina sequencing targeting the v3-v4 hypervariable regions of the 16S rRNA gene. No significant difference in microbial community composition, as well as rarefied OTU richness and diversity were detected between adults and nymphs. Nymphs showed a higher richness of bacterial taxa indicating blood-feeding could have resulted in loss of microbial diversity during the moulting stage from nymph to adult. Core OTUs that were in at least 50% of nymphs and adults negative and positive for Rickettsia at 1% minimum relative abundance were Rickettsia, Coxiella and Ruminococcaceae UCG-005 with a single genus Arsenophonus occurring only in nymphs negative for Rickettsia. Ehrlichia spp. was present in only four nymphal ticks positive for Rickettsia. Interestingly, Rickettsia&amp;nbsp;aeschlimannii was found in one nymph and one adult, indicating the first ever detection of the species in A. hebraeum. Furthermore, A. hebraeum harboured a Coxiella-like endosymbiont, which should be investigated further as Coxiella may affect the viability and transmission of other organisms.}, }
@article {pmid34450656, year = {2021}, author = {Verster, KI and Tarnopol, RL and Akalu, SM and Whiteman, NK}, title = {Horizontal Transfer of Microbial Toxin Genes to Gall Midge Genomes.}, journal = {Genome biology and evolution}, volume = {13}, number = {9}, pages = {}, pmid = {34450656}, issn = {1759-6653}, support = {R35 GM119816/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Aphids/genetics ; *Diptera/genetics ; Gene Transfer, Horizontal ; Genome ; Phylogeny ; }, abstract = {A growing body of evidence has underscored the role of horizontal gene transfer (HGT) in animal evolution. Previously, we discovered the horizontal transfer of the gene encoding the eukaryotic genotoxin cytolethal distending toxin B (cdtB) from the pea aphid Acyrthosiphon pisum secondary endosymbiont (APSE) phages to drosophilid and aphid nuclear genomes. Here, we report cdtB in the nuclear genome of the gall-forming "swede midge" Contarinia nasturtii (Diptera: Cecidomyiidae) via HGT. We searched all available gall midge genome sequences for evidence of APSE-to-insect HGT events and found five toxin genes (aip56, cdtB, lysozyme, rhs, and sltxB) transferred horizontally to cecidomyiid nuclear genomes. Surprisingly, phylogenetic analyses of HGT candidates indicated APSE phages were often not the ancestral donor lineage of the toxin gene to cecidomyiids. We used a phylogenetic signal statistic to test a transfer-by-proximity hypothesis for animal HGT, which suggested that microbe-to-insect HGT was more likely between taxa that share environments than those from different environments. Many of the toxins we found in midge genomes target eukaryotic cells, and catalytic residues important for toxin function are conserved in insect copies. This class of horizontally transferred, eukaryotic cell-targeting genes is potentially important in insect adaptation.}, }
@article {pmid34448004, year = {2021}, author = {Cruz, LNPD and Carvalho-Costa, LF and Rebêlo, JMM}, title = {Molecular Evidence Suggests That Wolbachia pipientis (Rickettsiales: Anaplasmataceae) is Widely Associated With South American Sand Flies (Diptera: Psychodidae).}, journal = {Journal of medical entomology}, volume = {58}, number = {6}, pages = {2186-2195}, doi = {10.1093/jme/tjab130}, pmid = {34448004}, issn = {1938-2928}, mesh = {Animals ; Brazil ; DNA, Bacterial/analysis ; Psychodidae/*physiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia pipientis (Hertig) is an endosymbiotic microorganism widespread among arthropods and other invertebrate hosts, and employed in strategies to reduce the incidence of arthropod-borne diseases. Here, we used a PCR-based approach for 16S RNA and wsp genes to investigate the prevalence, geographical distribution, and strains of Wolbachia in sand flies (Diptera: Psychodidae: Phlebotominae), the main vectors of the causative agents of leishmaniasis, from three biomes in Brazil: Amazon, Cerrado, and Caatinga. We found that: 1) Wolbachia DNA is present in most (66.7%) of the sampled sand fly species, including vectors of Leishmania spp. (Ross, Trypanosomatida: Trypanosomatidae), 2) the prevalence of Wolbachia DNA varies among species and populations, 3) some strains of Wolbachia may have wider geographical and host range in South America, and 4) two phylogenetic distinct wsp sequences might represent two novel strains for Wolbachia in South America sand flies. Those findings increase the basic knowledge about Wolbachia in South American sand flies and might foster further researches on its use to reduce the transmission of sand fly-borne parasites.}, }
@article {pmid34446060, year = {2021}, author = {Bergman, A and Hesson, JC}, title = {Wolbachia prevalence in the vector species Culex pipiens and Culex torrentium in a Sindbis virus-endemic region of Sweden.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {428}, pmid = {34446060}, issn = {1756-3305}, mesh = {Alphavirus Infections/*epidemiology/virology ; Animals ; Culex/classification/*microbiology ; Endemic Diseases ; Mosquito Vectors/*microbiology ; Prevalence ; Sindbis Virus/physiology ; Sweden/epidemiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {BACKGROUND: Wolbachia pipientis are endosymbiotic bacteria present in a large proportion of terrestrial arthropods. The species is known to sometimes affect the ability of its host to transmit vector-borne pathogens. Central Sweden is endemic for Sindbis virus (SINV), where it is mainly transmitted by the vector species Culex pipiens and Culex torrentium, with the latter established as the main vector. In this study we investigated the Wolbachia prevalence in these two vector species in a region highly endemic for SINV.<br><br>METHODS: Culex mosquitoes were collected using CDC light traps baited with carbon dioxide over 9 years at 50 collection sites across the River Dal&#xe4;lven floodplains in central Sweden. Mosquito genus was determined morphologically, while a molecular method was used for reliable species determination. The presence of Wolbachia was determined through PCR using general primers targeting the wsp gene and sequencing of selected samples.<br><br>RESULTS: In total, 676 Cx. pipiens and 293 Cx. torrentium were tested for Wolbachia. The prevalence of Wolbachia in Cx. pipiens was 97% (95% CI 94.8-97.6%), while only 0.7% (95% CI 0.19-2.45%) in Cx. torrentium. The two Cx. torrentium mosquitoes that were infected with Wolbachia carried different types of the bacteria.<br><br>CONCLUSIONS: The main vector of SINV in the investigated endemic region, Cx. torrentium, was seldom infected with Wolbachia, while it was highly prevalent in the secondary vector, Cx. pipiens. The presence of Wolbachia could potentially have an impact on the vector competence of these two species. Furthermore, the detection of Wolbachia in Cx. torrentium could indicate horizontal transmission of the endosymbiont between arthropods of different species.}, }
@article {pmid34442816, year = {2021}, author = {Osuna-Mascaró, C and Doña, J and Johnson, KP and de Rojas, M}, title = {Genome-Resolved Metagenomic Analyses Reveal the Presence of a Putative Bacterial Endosymbiont in an Avian Nasal Mite (Rhinonyssidae; Mesostigmata).}, journal = {Microorganisms}, volume = {9}, number = {8}, pages = {}, pmid = {34442816}, issn = {2076-2607}, abstract = {Rhinonyssidae (Mesostigmata) is a family of nasal mites only found in birds. All species are hematophagous endoparasites, which may damage the nasal cavities of birds, and also could be potential reservoirs or vectors of other infections. However, the role of members of Rhinonyssidae as disease vectors in wild bird populations remains uninvestigated, with studies of the microbiomes of Rhinonyssidae being almost non-existent. In the nasal mite (Tinaminyssus melloi) from rock doves (Columba livia), a previous study found evidence of a highly abundant putatively endosymbiotic bacteria from Class Alphaproteobacteria. Here, we expanded the sample size of this species (two different hosts- ten nasal mites from two independent samples per host), incorporated contamination controls, and increased sequencing depth in shotgun sequencing and genome-resolved metagenomic analyses. Our goal was to increase the information regarding this mite species and its putative endosymbiont. We obtained a metagenome assembled genome (MAG) that was estimated to be 98.1% complete and containing only 0.9% possible contamination. Moreover, the MAG has characteristics typical of endosymbionts (namely, small genome size an AT bias). Overall, our results support the presence of a potential endosymbiont, which is the first described for avian nasal mites to date, and improve the overall understanding of the microbiota inhabiting these mites.}, }
@article {pmid34442312, year = {2021}, author = {Barman, M and Samanta, S and Thakur, H and Chakraborty, S and Samanta, A and Ghosh, A and Tarafdar, J}, title = {Effect of Neonicotinoids on Bacterial Symbionts and Insecticide-Resistant Gene in Whitefly, Bemisia tabaci.}, journal = {Insects}, volume = {12}, number = {8}, pages = {}, pmid = {34442312}, issn = {2075-4450}, abstract = {The silverleaf whitefly, Bemisia tabaci (Gennadius, Hemiptera: Aleyrodidae), is a major threat to field and horticultural crops worldwide. Persistent use of insecticides for the management of this pest is a lingering problem. In the present study, the status of sensitivity of B. tabaci to two neonicotinoids, imidacloprid and thiamethoxam, was evaluated. The expression pattern of two cytochrome P450 (cyp) genes and changes in the relative amount of symbionts in insecticide-treated B. tabaci were also assessed. Quantitative PCR (qPCR) studies indicate that the CYP6CM1 and CYP6CX1 genes were always expressed higher in imidacloprid-treated whitefly, suggesting a correlation between gene expression and the insect's ability to detoxify toxic compounds such as insecticides. In addition, the thiamethoxam-treated population harbored higher Portiera and lower Rickettsia titers, whereas the imidacloprid-treated population harbored more Rickettsia at different time intervals. Interestingly, we also examined that an increase in exposure to both the insecticides resulted in a reduction in the mutualistic partners from their insect host. These differential responses of endosymbionts to insecticide exposure imply the complex interactions among the symbionts inside the host insect. The results also provide a deeper understanding of the molecular mechanism of resistance development that might be useful for formulating effective management strategies to control B. tabaci by manipulating symbionts and detoxifying genes.}, }
@article {pmid34438657, year = {2021}, author = {Silva, RXG and Cartaxana, P and Calado, R}, title = {Prevalence and Photobiology of Photosynthetic Dinoflagellate Endosymbionts in the Nudibranch Berghia stephanieae.}, journal = {Animals : an open access journal from MDPI}, volume = {11}, number = {8}, pages = {}, pmid = {34438657}, issn = {2076-2615}, abstract = {Berghia stephanieae is a stenophagous sea slug that preys upon glass anemones, such as Exaiptasia diaphana. Glass anemones host photosynthetic dinoflagellate endosymbionts that sea slugs ingest when consuming E. diaphana. However, the prevalence of these photosynthetic dinoflagellate endosymbionts in sea slugs appears to be short-lived, particularly if B.stephanieae is deprived of prey that host these microalgae (e.g., during bleaching events impacting glass anemones). In the present study, we investigated this scenario, along with food deprivation, and validated the use of a non-invasive and non-destructive approach employing chlorophyll fluorescence as a proxy to monitor the persistence of the association between sea slugs and endosymbiotic photosynthetic dinoflagellates acquired through the consumption of glass anemones. Berghia stephanieae deprived of a trophic source hosting photosynthetic dinoflagellate endosymbionts (e.g., through food deprivation or by feeding on bleached E. diaphana) showed a rapid decrease in minimum fluorescence (Fo) and photosynthetic efficiency (Fv/Fm) when compared to sea slugs fed with symbiotic anemones. A complete loss of endosymbionts was observed within 8 days, confirming that no true symbiotic association was established. The present work opens a new window of opportunity to rapidly monitor in vivo and over time the prevalence of associations between sea slugs and photosynthetic dinoflagellate endosymbionts, particularly during bleaching events that prevent sea slugs from incorporating new microalgae through trophic interactions.}, }
@article {pmid34436602, year = {2021}, author = {Petrů, M and Dohnálek, V and Füssy, Z and Doležal, P}, title = {Fates of Sec, Tat, and YidC Translocases in Mitochondria and Other Eukaryotic Compartments.}, journal = {Molecular biology and evolution}, volume = {38}, number = {12}, pages = {5241-5254}, pmid = {34436602}, issn = {1537-1719}, mesh = {*Escherichia coli Proteins/genetics ; *Eukaryota/genetics/metabolism ; Evolution, Molecular ; Membrane Transport Proteins/genetics/metabolism ; Mitochondria/genetics/metabolism ; Mitochondrial Proteins/genetics/metabolism ; Protein Transport ; }, abstract = {Formation of mitochondria by the conversion of a bacterial endosymbiont was a key moment in the evolution of eukaryotes. It was made possible by outsourcing the endosymbiont's genetic control to the host nucleus, while developing the import machinery for proteins synthesized on cytosolic ribosomes. The original protein export machines of the nascent organelle remained to be repurposed or were completely abandoned. This review follows the evolutionary fates of three prokaryotic inner membrane translocases Sec, Tat, and YidC. Homologs of all three translocases can still be found in current mitochondria, but with different importance for mitochondrial function. Although the mitochondrial YidC homolog, Oxa1, became an omnipresent independent insertase, the other two remained only sporadically present in mitochondria. Only a single substrate is known for the mitochondrial Tat and no function has yet been assigned for the mitochondrial Sec. Finally, this review compares these ancestral mitochondrial proteins with their paralogs operating in the plastids and the endomembrane system.}, }
@article {pmid34429360, year = {2021}, author = {Perreau, J and Zhang, B and Maeda, GP and Kirkpatrick, M and Moran, NA}, title = {Strong within-host selection in a maternally inherited obligate symbiont: Buchnera and aphids.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {35}, pages = {}, pmid = {34429360}, issn = {1091-6490}, support = {R01 GM116853/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aphids/genetics/*microbiology ; Buchnera/*physiology ; *Genetic Drift ; Genome ; *Haplotypes ; *Host Microbial Interactions ; *Maternal Inheritance ; Phylogeny ; Reproduction ; *Symbiosis ; }, abstract = {Numerous animal lineages have maternally inherited symbionts that are required for host reproduction and growth. Endosymbionts also pose a risk to their hosts because of the mutational decay of their genomes through genetic drift or to selfish mutations that favor symbiont fitness over host fitness. One model for heritable endosymbiosis is the association of aphids with their obligate bacterial symbiont, Buchnera We experimentally established heteroplasmic pea aphid matrilines containing pairs of closely related Buchnera haplotypes and used deep sequencing of diagnostic markers to measure haplotype frequencies in successive host generations. These frequencies were used to estimate the effective population size of Buchnera within hosts (i.e., the transmission bottleneck size) and the extent of within-host selection. The within-host effective population size was in the range of 10 to 20, indicating a strong potential for genetic drift and fixation of deleterious mutations. Remarkably, closely related haplotypes were subject to strong within-host selection, with selection coefficients as high as 0.5 per aphid generation. In one case, the direction of selection depended on the thermal environment and went in the same direction as between-host selection. In another, a new mutant haplotype had a strong within-host advantage under both environments but had no discernible effect on host-level fitness under laboratory conditions. Thus, within-host selection can be strong, resulting in a rapid fixation of mutations with little impact on host-level fitness. Together, these results show that within-host selection can drive evolution of an obligate symbiont, accelerating sequence evolution.}, }
@article {pmid34429226, year = {2022}, author = {Maire, J and van Oppen, MJH}, title = {A role for bacterial experimental evolution in coral bleaching mitigation?.}, journal = {Trends in microbiology}, volume = {30}, number = {3}, pages = {217-228}, doi = {10.1016/j.tim.2021.07.006}, pmid = {34429226}, issn = {1878-4380}, mesh = {Animals ; *Anthozoa ; Bacteria/genetics ; Climate Change ; *Coral Bleaching ; Coral Reefs ; Seawater ; }, abstract = {Coral reefs are rapidly declining because of widespread mass coral bleaching causing extensive coral mortality. Elevated seawater temperatures are the main drivers of coral bleaching, and climate change is increasing the frequency and severity of destructive marine heatwaves. Efforts to enhance coral thermal bleaching tolerance can be targeted at the coral host or at coral-associated microorganisms (e.g., dinoflagellate endosymbionts and bacteria). The literature on experimental evolution of bacteria suggests that it has value as a tool to increase coral climate resilience. We provide a workflow on how to experimentally evolve coral-associated bacteria to confer thermal tolerance to coral hosts and emphasize the value of implementing this approach in coral reef conservation and restoration efforts.}, }
@article {pmid34426845, year = {2021}, author = {Kinjo, Y and Lo, N and Martín, PV and Tokuda, G and Pigolotti, S and Bourguignon, T}, title = {Enhanced Mutation Rate, Relaxed Selection, and the "Domino Effect" are associated with Gene Loss in Blattabacterium, A Cockroach Endosymbiont.}, journal = {Molecular biology and evolution}, volume = {38}, number = {9}, pages = {3820-3831}, pmid = {34426845}, issn = {1537-1719}, mesh = {Animals ; Bacteroidetes/*genetics ; Cockroaches/*microbiology ; *Genome, Bacterial ; *Mutation Rate ; Selection, Genetic ; Symbiosis/*genetics ; }, abstract = {Intracellular endosymbionts have reduced genomes that progressively lose genes at a timescale of tens of million years. We previously reported that gene loss rate is linked to mutation rate in Blattabacterium, however, the mechanisms causing gene loss are not yet fully understood. Here, we carried out comparative genomic analyses on the complete genome sequences of a representative set of 67 Blattabacterium strains, with sizes ranging between 511 and 645 kb. We found that 200 of the 566 analyzed protein-coding genes were lost in at least one lineage of Blattabacterium, with the most extreme case being one gene that was lost independently in 24 lineages. We found evidence for three mechanisms influencing gene loss in Blattabacterium. First, gene loss rates were found to increase exponentially with the accumulation of substitutions. Second, genes involved in vitamin and amino acid metabolism experienced relaxed selection in Cryptocercus and Mastotermes, possibly triggered by their vertically inherited gut symbionts. Third, we found evidence of epistatic interactions among genes leading to a "domino effect" of gene loss within pathways. Our results highlight the complexity of the process of genome erosion in an endosymbiont.}, }
@article {pmid34422675, year = {2021}, author = {Fichorova, RN and DeLong, AK and Cu-Uvin, S and King, CC and Jamieson, DJ and Klein, RS and Sobel, JD and Vlahov, D and Yamamoto, HS and Mayer, KH}, title = {Protozoan-Viral-Bacterial Co-Infections Alter Galectin Levels and Associated Immunity Mediators in the Female Genital Tract.}, journal = {Frontiers in cellular and infection microbiology}, volume = {11}, number = {}, pages = {649940}, pmid = {34422675}, issn = {2235-2988}, support = {P30 AI042853/AI/NIAID NIH HHS/United States ; R01 AI079085/AI/NIAID NIH HHS/United States ; R56 AI091889/AI/NIAID NIH HHS/United States ; RC1 AI086788/AI/NIAID NIH HHS/United States ; }, mesh = {Bacteria ; *Coinfection ; Female ; Galectin 3 ; Humans ; Prevotella ; *Trichomonas Vaginitis ; *Virus Diseases ; }, abstract = {Co-infections with sexually transmittable pathogens are common and more likely in women with disturbed vaginal bacteriome. Among those pathogens, the protozoan parasite Trichomonas vaginalis (TV) is most common after accounting for the highly persistent DNA viruses human papillomavirus (HPV) and genital herpes. The parasitic infection often concurs with the dysbiotic syndrome diagnosed as bacterial vaginosis (BV) and both are associated with risks of superimposed viral infections. Yet, the mechanisms of microbial synergisms in evading host immunity remain elusive. We present clinical and experimental evidence for a new role of galectins, glycan-sensing family of proteins, in mixed infections. We assessed participants of the HIV Epidemiology Research Study (HERS) at each of their incident TV visits (223 case visits) matched to controls who remained TV-negative throughout the study. Matching criteria included age, race, BV (by Nugent score), HIV status, hysterectomy, and contraceptive use. Non-matched variables included BV status at 6 months before the matched visit, and variables examined at baseline, within 6 months of and/or at the matched visit e.g. HSV-2, HPV, and relevant laboratory and socio-demographic parameters. Conditional logistic regression models using generalized estimating equations calculated odds ratios (OR) for incident TV occurrence with each log10 unit higher cervicovaginal concentration of galectins and cytokines. Incident TV was associated with higher levels of galectin-1, galectin-9, IL-1β and chemokines (ORs 1.53 to 2.91, p <0.001). Galectin-9, IL-1β and chemokines were up and galectin-3 down in TV cases with BV or intermediate Nugent versus normal Nugent scores (p <0.001). Galectin-9, IL-1β and chemokines were up in TV-HIV and down in TV-HPV co-infections. In-vitro, TV synergized with its endosymbiont Trichomonasvirus (TVV) and BV bacteria to upregulate galectin-1, galectin-9, and inflammatory cytokines. The BV-bacterium Prevotella bivia alone and together with TV downregulated galectin-3 and synergistically upregulated galectin-1, galectin-9 and IL-1β, mirroring the clinical findings of mixed TV-BV infections. P. bivia also downregulated TVV+TV-induced anti-viral response e.g. IP-10 and RANTES, providing a mechanism for conducing viral persistence in TV-BV co-infections. Collectively, the experimental and clinical data suggest that galectin-mediated immunity may be dysregulated and exploited by viral-protozoan-bacterial synergisms exacerbating inflammatory complications from dysbiosis and sexually transmitted infections.}, }
@article {pmid34413841, year = {2021}, author = {Vaccaro, L and Gomes, TS and Izquierdo, F and Magnet, A and Llorens Berzosa, S and Ollero, D and Salso, S and Alhambra, A and Gómez, C and López Cano, M and Pelaz, C and Bellido Samaniego, B and Del Aguila, C and Fenoy, S and Hurtado-Marcos, C}, title = {Legionella feeleii: Ubiquitous Pathogen in the Environment and Causative Agent of Pneumonia.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {707187}, pmid = {34413841}, issn = {1664-302X}, abstract = {L. feeleii is one of the most frequent Legionella species isolated from natural pools of the central region of Spain. This study aimed to evaluate its ecology and to identify this Legionella species as a respiratory pathogen. A PCR assay for detecting the L. feeleii mip gene was developed to identify it in clinical and environmental samples. Culture and PCR were performed in environmental samples from four drinking water treatment plants (DWTPs). Free L. feeleii was only detected in raw water samples (3.4%), while L. feeleii as an Acanthamoeba endosymbiont was found in 30.7% of raw water, 11.5% of decanter biofilm, and 32% of finished water samples. Therefore, Acanthamoeba spp. plays an essential role in the multiplication, persistence, and spread of Legionella species in the environment. The first case of Legionnaires' disease caused by L. feeleii in Spain is described in this study. The case was diagnosed in an older woman through PCR and sequencing from urine and sputum samples. A respiratory infection could be linked with health care procedures, and the patient presented several risk factors (age, insulin-dependent diabetes, and heart disease). The detection of non-L. pneumophila, such as L. feeleii, is a factor that must be considered when establishing or reviewing measures for the control and prevention of legionellosis.}, }
@article {pmid34402109, year = {2021}, author = {Arif, S and Gerth, M and Hone-Millard, WG and Nunes, MDS and Dapporto, L and Shreeve, TG}, title = {Evidence for multiple colonisations and Wolbachia infections shaping the genetic structure of the widespread butterfly Polyommatus icarus in the British Isles.}, journal = {Molecular ecology}, volume = {30}, number = {20}, pages = {5196-5213}, doi = {10.1111/mec.16126}, pmid = {34402109}, issn = {1365-294X}, mesh = {Animals ; *Butterflies/genetics ; DNA, Mitochondrial/genetics ; Genetic Structures ; Genetic Variation ; Phylogeny ; Phylogeography ; Refugium ; *Wolbachia/genetics ; }, abstract = {The paradigm of isolation in southern refugia during glacial periods followed by expansions during interglacials, producing limited genetic differentiation in northern areas, dominates European phylogeography. However, the existence of complex structured populations in formerly glaciated areas, and islands connected to mainland areas during glacial maxima, call for alternative explanations. We reconstructed the mtDNA phylogeography of the widespread Polyommatus Icarus butterfly with an emphasis on the formerly glaciated and connected British Isles. We found distinct geographical structuring of CO1 haplogroups, with an ancient lineage restricted to the marginal European areas, including Northern Scotland and Outer Hebrides. Population genomic analyses, using ddRADSeq genomic markers, also reveal substantial genetic structuring within Britain. However, there is negligble mito-nuclear concordance consistent with independent demographic histories of mitochondrial versus nuclear DNA. While mtDNA-Wolbachia associations in northern Britain could account for the geographic structuring of mtDNA across most of the British Isles, for nuclear DNA markers (derived from ddRADseq data) butterflies from France cluster between northern and southern British populations - an observation consistent with a scenario of multiple recolonisation. Taken together our results suggest that contemporary mtDNA structuring in the British Isles (and potentially elsewhere in Europe) largely results from Wolbachia infections, however, nuclear genomic structuring suggests a history of at least two distinct colonisations. This two-stage colonisation scenario has previously been put forth to explain genetic diversity and structuring in other British flora and fauna. Additionally, we also present preliminary evidence for potential Wolbachia-induced feminization in the Outer Hebrides.}, }
@article {pmid34399629, year = {2021}, author = {Zakharova, A and Saura, A and Butenko, A and Podešvová, L and Warmusová, S and Kostygov, AY and Nenarokova, A and Lukeš, J and Opperdoes, FR and Yurchenko, V}, title = {A New Model Trypanosomatid, Novymonas esmeraldas: Genomic Perception of Its "Candidatus Pandoraea novymonadis" Endosymbiont.}, journal = {mBio}, volume = {12}, number = {4}, pages = {e0160621}, pmid = {34399629}, issn = {2150-7511}, mesh = {Bacteria/classification/*genetics/*metabolism ; *Genome, Bacterial ; Genomics ; Phylogeny ; Symbiosis/*genetics ; Trypanosoma/classification/*metabolism/*microbiology ; }, abstract = {The closest relative of human pathogen Leishmania, the trypanosomatid Novymonas esmeraldas, harbors a bacterial endosymbiont "Candidatus Pandoraea novymonadis." Based on genomic data, we performed a detailed characterization of the metabolic interactions of both partners. While in many respects the metabolism of N. esmeraldas resembles that of other Leishmaniinae, the endosymbiont provides the trypanosomatid with heme, essential amino acids, purines, some coenzymes, and vitamins. In return, N. esmeraldas shares with the bacterium several nonessential amino acids and phospholipids. Moreover, it complements its carbohydrate metabolism and urea cycle with enzymes missing from the "Ca. Pandoraea novymonadis" genome. The removal of the endosymbiont from N. esmeraldas results in a significant reduction of the overall translation rate, reduced expression of genes involved in lipid metabolism and mitochondrial respiratory activity, and downregulation of several aminoacyl-tRNA synthetases, enzymes involved in the synthesis of some amino acids, as well as proteins associated with autophagy. At the same time, the genes responsible for protection against reactive oxygen species and DNA repair become significantly upregulated in the aposymbiotic strain of this trypanosomatid. By knocking out a component of its flagellum, we turned N. esmeraldas into a new model trypanosomatid that is amenable to genetic manipulation using both conventional and CRISPR-Cas9-mediated approaches. IMPORTANCENovymonas esmeraldas is a parasitic flagellate of the family Trypanosomatidae representing the closest insect-restricted relative of the human pathogen Leishmania. It bears symbiotic bacteria in its cytoplasm, the relationship with which has been established relatively recently and independently from other known endosymbioses in protists. Here, using the genome analysis and comparison of transcriptomic profiles of N. esmeraldas with and without the endosymbionts, we describe a uniquely complex cooperation between both partners on the biochemical level. We demonstrate that the removal of bacteria leads to a decelerated growth of N. esmeraldas, substantial suppression of many metabolic pathways, and increased oxidative stress. Our success with the genetic transformation of this flagellate makes it a new model trypanosomatid species that can be used for the dissection of mechanisms underlying the symbiotic relationships between protists and bacteria.}, }
@article {pmid34394061, year = {2021}, author = {Gesto, JSM and Pinto, SB and Dias, FBS and Peixoto, J and Costa, G and Kutcher, S and Montgomery, J and Green, BR and Anders, KL and Ryan, PA and Simmons, CP and O'Neill, SL and Moreira, LA}, title = {Large-Scale Deployment and Establishment of Wolbachia Into the Aedes aegypti Population in Rio de Janeiro, Brazil.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {711107}, pmid = {34394061}, issn = {1664-302X}, abstract = {Traditional methods of vector control have proven insufficient to reduce the alarming incidence of dengue, Zika, and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-infected adults were released across residential areas between August 2017 and March 2020. Over 131 weeks, including release and post-release phases, we monitored the wMel prevalence in field specimens and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel successfully invaded both areas, reaching overall infection rates of 50-70% in RJ1 and 30-60% in RJ2 by the end of the monitoring period. At the neighborhood-level, wMel introgression was heterogeneous in both RJ1 and RJ2, with some profiles sustaining a consistent increase in infection rates and others failing to elicit the same. Correlation analysis revealed a weak overall association between RJ1 and RJ2 (r = 0.2849, p = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, p < 0.0001) or RJ2 (r = 0.6263, p < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas were consistently high over this study. Altogether, these findings corroborate that wMel can be successfully deployed at large-scale as part of vector control intervention strategies and provide the basis for imminent disease impact studies in Southeastern Brazil.}, }
@article {pmid34390927, year = {2021}, author = {Calderon, RH and Strand, &#xc5;}, title = {How retrograde signaling is intertwined with the evolution of photosynthetic eukaryotes.}, journal = {Current opinion in plant biology}, volume = {63}, number = {}, pages = {102093}, doi = {10.1016/j.pbi.2021.102093}, pmid = {34390927}, issn = {1879-0356}, mesh = {Biological Evolution ; *Eukaryota ; Photosynthesis/genetics ; Phylogeny ; *Plastids/genetics ; Symbiosis/genetics ; }, abstract = {Chloroplasts and mitochondria evolved from free-living prokaryotic organisms that entered the eukaryotic cell through endosymbiosis. The gradual conversion from endosymbiont to organelle during the course of evolution was accompanied by the development of a communication system between the host and the endosymbiont, referred to as retrograde signaling or organelle-to-nucleus signaling. In higher plants, plastid-to-nucleus signaling involves multiple signaling pathways necessary to coordinate plastid function and cellular responses to developmental and environmental stimuli. Phylogenetic reconstructions using sequence information from evolutionarily diverse photosynthetic eukaryotes have begun to provide information about how retrograde signaling pathways were adopted and modified in different lineages over time. A tight communication system was likely a major facilitator of plants conquest of the land because it would have enabled the algal ancestors of land plants to better allocate their cellular resources in response to high light and desiccation, the major stressor for streptophyte algae in a terrestrial habitat. In this review, we aim to give an evolutionary perspective on plastid-to-nucleus signaling.}, }
@article {pmid34390609, year = {2021}, author = {Towett-Kirui, S and Morrow, JL and Close, S and Royer, JE and Riegler, M}, title = {Host-endoparasitoid-endosymbiont relationships: concealed Strepsiptera provide new twist to Wolbachia in Australian tephritid fruit flies.}, journal = {Environmental microbiology}, volume = {23}, number = {9}, pages = {5587-5604}, doi = {10.1111/1462-2920.15715}, pmid = {34390609}, issn = {1462-2920}, mesh = {Animals ; Australia ; *Symbiosis ; *Tephritidae/microbiology ; *Wolbachia/genetics ; }, abstract = {Wolbachia are widespread endosymbionts that affect arthropod reproduction and fitness. Mostly maternally inherited, Wolbachia are occasionally transferred horizontally. Previously, two Wolbachia strains were reported at low prevalence and titres across seven Australian tephritid species, possibly indicative of frequent horizontal transfer. Here, we performed whole-genome sequencing of field-caught Wolbachia-positive flies. Unexpectedly, we found complete mitogenomes of an endoparasitic strepsipteran, Dipterophagus daci, suggesting that Wolbachia in the flies are linked to concealed parasitization. We performed the first genetic characterization of D. daci and detected D. daci in Wolbachia-positive flies not visibly parasitized, and most but not all Wolbachia-negative flies were D. daci-negative, presumably reflecting polymorphism for the Wolbachia infections in D. daci. We dissected D. daci from stylopized flies and confirmed that Wolbachia infects D. daci, but also found Wolbachia in stylopized fly tissues, likely somatic, horizontally transferred, non-heritable infections. Furthermore, no Wolbachia cif and wmk genes were detected and very low mitogenomic variation in D. daci across its distribution. Therefore, Wolbachia may influence host fitness without reproductive manipulation. Our study of 13 tephritid species highlights that concealed early stages of strepsipteran parasitization led to the previous incorrect assignment of Wolbachia co-infections to tephritid species, obscuring ecological studies of this common endosymbiont and its horizontal transmission by parasitoids.}, }
@article {pmid34388986, year = {2021}, author = {Morrow, JL and Riegler, M}, title = {Genome analyses of four Wolbachia strains and associated mitochondria of Rhagoletis cerasi expose cumulative modularity of cytoplasmic incompatibility factors and cytoplasmic hitchhiking across host populations.}, journal = {BMC genomics}, volume = {22}, number = {1}, pages = {616}, pmid = {34388986}, issn = {1471-2164}, mesh = {Animals ; Biological Evolution ; Cytoplasm ; Humans ; Mitochondria ; Symbiosis/genetics ; *Tephritidae ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: The endosymbiont Wolbachia can manipulate arthropod reproduction and invade host populations by inducing cytoplasmic incompatibility (CI). Some host species are coinfected with multiple Wolbachia strains which may have sequentially invaded host populations by expressing different types of modular CI factor (cif) genes. The tephritid fruit fly Rhagoletis cerasi is a model for CI and Wolbachia population dynamics. It is associated with at least four Wolbachia strains in various combinations, with demonstrated (wCer2, wCer4), predicted (wCer1) or unknown (wCer5) CI phenotypes.<br><br>RESULTS: We sequenced and assembled the draft genomes of the Wolbachia strains wCer1, wCer4 and wCer5, and compared these with the previously sequenced genome of wCer2 which currently invades R. cerasi populations. We found complete cif gene pairs in all strains: four pairs in wCer2 (three Type I; one Type V), two pairs in wCer1 (both Type I) and wCer4 (one Type I; one Type V), and one pair in wCer5 (Type IV). Wolbachia genome variant analyses across geographically and genetically distant host populations revealed the largest diversity of single nucleotide polymorphisms (SNPs) in wCer5, followed by wCer1 and then wCer2, indicative of their different lengths of host associations. Furthermore, mitogenome analyses of the Wolbachia genome-sequenced individuals in combination with SNP data from six European countries revealed polymorphic mitogenome sites that displayed reduced diversity in individuals infected with wCer2 compared to those without.<br><br>CONCLUSIONS: Coinfections with Wolbachia are common in arthropods and affect options for Wolbachia-based management strategies of pest and vector species already infected by Wolbachia. Our analyses of Wolbachia genomes of a host naturally coinfected&#xa0;by several strains unravelled signatures of the evolutionary dynamics in both Wolbachia and host mitochondrial genomes as a consequence of repeated invasions. Invasion of already infected populations by new Wolbachia strains requires new sets of functionally different cif genes and thereby may select for a cumulative modularity of cif gene diversity in invading strains. Furthermore, we demonstrated at the mitogenomic scale that repeated CI-driven Wolbachia invasions of hosts result in reduced mitochondrial diversity and hitchhiking effects. Already resident Wolbachia strains may experience similar cytoplasmic hitchhiking effects caused by the invading Wolbachia strain.}, }
@article {pmid34379678, year = {2021}, author = {Fakhour, S and Renoz, F and Ambroise, J and Pons, I and Noël, C and Gala, JL and Hance, T}, title = {Insight into the bacterial communities of the subterranean aphid Anoecia corni.}, journal = {PloS one}, volume = {16}, number = {8}, pages = {e0256019}, pmid = {34379678}, issn = {1932-6203}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*classification/genetics/*isolation &amp; purification ; *Biodiversity ; *Biological Evolution ; *Genetic Variation ; High-Throughput Nucleotide Sequencing ; Microbiota ; Morocco ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Many insect species are associated with bacterial partners that can significantly influence their evolutionary ecology. Compared to other insect groups, aphids harbor a bacterial microbiota that has the reputation of being poorly diversified, generally limited to the presence of the obligate nutritional symbiont Buchnera aphidicola and some facultative symbionts. In this study, we analyzed the bacterial diversity associated with the dogwood-grass aphid Anoecia corni, an aphid species that spends much of its life cycle in a subterranean environment. Little is known about the bacterial diversity associated with aphids displaying such a lifestyle, and one hypothesis is that close contact with the vast microbial community of the rhizosphere could promote the acquisition of a richer bacterial diversity compared to other aphid species. Using 16S rRNA amplicon Illumina sequencing on specimens collected on wheat roots in Morocco, we identified 10 bacterial operational taxonomic units (OTUs) corresponding to five bacterial genera. In addition to the obligate symbiont Buchnera, we identified the facultative symbionts Serratia symbiotica and Wolbachia in certain aphid colonies. The detection of Wolbachia is unexpected as it is considered rare in aphids. Moreover, its biological significance remains unknown in these insects. Besides, we also detected Arsenophonus and Dactylopiibacterium carminicum. These results suggest that, despite its subterranean lifestyle, A. corni shelter a bacterial diversity mainly limited to bacterial endosymbionts.}, }
@article {pmid34371395, year = {2021}, author = {Ferreira, V and Pavlaki, MD and Martins, R and Monteiro, MS and Maia, F and Tedim, J and Soares, AMVM and Calado, R and Loureiro, S}, title = {Effects of nanostructure antifouling biocides towards a coral species in the context of global changes.}, journal = {The Science of the total environment}, volume = {799}, number = {}, pages = {149324}, doi = {10.1016/j.scitotenv.2021.149324}, pmid = {34371395}, issn = {1879-1026}, mesh = {Animals ; *Anthozoa ; *Biofouling/prevention &amp; control ; Coral Reefs ; *Disinfectants/toxicity ; Ecosystem ; *Nanostructures/toxicity ; Thiazoles ; }, abstract = {Biofouling prevention is one of the biggest challenges faced by the maritime industry, but antifouling agents commonly impact marine ecosystems. Advances in antifouling technology include the use of nanomaterials. Herein we test an antifouling nano-additive based on the encapsulation of the biocide 4,5-dichloro-2-octyl-4-isothiazolin-3-one (DCOIT) in engineered silica nanocontainers (SiNC). The work aims to assess the biochemical and physiological effects on the symbiotic coral Sarcophyton cf. glaucum caused by (1) thermal stress and (2) DCOIT exposure (free or nanoencapsulated forms), in a climate change scenario. Accordingly, the following hypotheses were addressed: (H1) ocean warming can cause toxicity on S. cf. glaucum; (H2) the nanoencapsulation process decreases DCOIT toxicity towards this species; (H3) the biocide toxicity, free or encapsulated forms, can be affected by ocean warming. Coral fragments were exposed for seven days to DCOIT in both free and encapsulated forms, SiNC and negative controls, under two water temperature regimes (26 °C and 30.5 °C). Coral polyp behavior and photosynthetic efficiency were determined in the holobiont, while biochemical markers were assessed individually in the endosymbiont and coral host. Results showed transient coral polyp retraction and diminished photosynthetic efficiency in the presence of heat stress or free DCOIT, with effects being magnified in the presence of both stressors. The activity of catalase and glutathione-S-transferase were modulated by temperature in each partner of the symbiosis. The shifts in enzymatic activity were more pronounced in the presence of free DCOIT, but to a lower extent for encapsulated DCOIT. Increased levels of oxidative damage were detected under heat conditions. The findings highlight the physiological constrains elicited by the increase of seawater temperature to symbiotic corals and demonstrate that DCOIT toxicity can be minimized through encapsulation in SiNC. The presence of both stressors magnifies toxicity and confirm that ocean warming enhances the vulnerability of tropical photosynthetic corals to local stressors.}, }
@article {pmid34370055, year = {2022}, author = {Travanty, NV and Vargo, EL and Apperson, CS and Ponnusamy, L}, title = {Colonization by the Red Imported Fire Ant, Solenopsis invicta, Modifies Soil Bacterial Communities.}, journal = {Microbial ecology}, volume = {84}, number = {1}, pages = {240-256}, pmid = {34370055}, issn = {1432-184X}, mesh = {Animals ; *Ants/microbiology ; Bacteria/genetics ; Ecosystem ; RNA, Ribosomal, 16S/genetics ; Soil ; }, abstract = {The long-standing association between insects and microorganisms has been especially crucial to the evolutionary and ecological success of social insect groups. Notably, research on the interaction of the two social forms (monogyne and polygyne) of the red imported fire ant (RIFA), Solenopsis invicta Buren, with microbes in its soil habitat is presently limited. In this study, we characterized bacterial microbiomes associated with RIFA nest soils and native (RIFA-negative) soils to better understand the effects of colonization of RIFA on soil microbial communities. Bacterial community fingerprints of 16S rRNA amplicons using denaturing gradient gel electrophoresis revealed significant differences in the structure of the bacterial communities between RIFA-positive and RIFA-negative soils at 0 and 10 cm depths. Illumina sequencing of 16S rRNA amplicons provided fine-scale analysis to test for effects of RIFA colonization, RIFA social form, and soil depth on the composition of the bacterial microbiomes of the soil and RIFA workers. Our results showed the bacterial community structure of RIFA-colonized soils to be significantly different from native soil communities and to evidence elevated abundances of several taxa, including Actinobacteria. Colony social form was not found to be a significant factor in nest or RIFA worker microbiome compositions. RIFA workers and nest soils were determined to have markedly different bacterial communities, with RIFA worker microbiomes being characterized by high abundances of a Bartonella-like endosymbiont and Entomoplasmataceae. Cloning and sequencing of the 16S rRNA gene revealed the Bartonella sp. to be a novel bacterium.}, }
@article {pmid34367558, year = {2021}, author = {Wheeler, TB and Thompson, V and Conner, WR and Cooper, BS}, title = {Wolbachia in the spittlebug Prosapia ignipectus: Variable infection frequencies, but no apparent effect on host reproductive isolation.}, journal = {Ecology and evolution}, volume = {11}, number = {15}, pages = {10054-10065}, pmid = {34367558}, issn = {2045-7758}, abstract = {Animals serve as hosts for complex communities of microorganisms, including endosymbionts that live inside their cells. Wolbachia bacteria are perhaps the most common endosymbionts, manipulating host reproduction to propagate. Many Wolbachia cause cytoplasmic incompatibility (CI), which results in reduced egg hatch when uninfected females mate with infected males. Wolbachia that cause intense CI spread to high and relatively stable frequencies, while strains that cause weak or no CI tend to persist at intermediate, often variable, frequencies. Wolbachia could also contribute to host reproductive isolation (RI), although current support for such contributions is limited to a few systems. To test for Wolbachia frequency variation and effects on host RI, we sampled several local Prosapia ignipectus (Fitch) (Hemiptera: Cercopidae) spittlebug populations in the northeastern United States over two years, including closely juxtaposed Maine populations with different monomorphic color forms, "black" and "lined." We discovered a group-B Wolbachia (wPig) infecting P. ignipectus that diverged from group-A Wolbachia-like model wMel and wRi strains in Drosophila-6 to 46 MYA. Populations of the sister species Prosapia bicincta (Say) from Hawaii and Florida are uninfected, suggesting that P. ignipectus acquired wPig after their initial divergence. wPig frequencies were generally high and variable among sites and between years. While phenotyping wPig effects on host reproduction is not currently feasible, the wPig genome contains three divergent sets of CI loci, consistent with high wPig frequencies. Finally, Maine monomorphic black and monomorphic lined populations of P. ignipectus share both wPig and mtDNA haplotypes, implying no apparent effect of wPig on the maintenance of this morphological contact zone. We hypothesize P. ignipectus acquired wPig horizontally as observed for many Drosophila species, and that significant CI and variable transmission produce high but variable wPig frequencies.}, }
@article {pmid34364896, year = {2021}, author = {Mendoza-Roldan, JA and Gabrielli, S and Cascio, A and Manoj, RRS and Bezerra-Santos, MA and Benelli, G and Brianti, E and Latrofa, MS and Otranto, D}, title = {Zoonotic Dirofilaria immitis and Dirofilaria repens infection in humans and an integrative approach to the diagnosis.}, journal = {Acta tropica}, volume = {223}, number = {}, pages = {106083}, doi = {10.1016/j.actatropica.2021.106083}, pmid = {34364896}, issn = {1873-6254}, mesh = {Animals ; *Dirofilaria immitis/genetics ; *Dirofilaria repens/genetics ; *Dirofilariasis/diagnosis/epidemiology ; Dog Diseases/diagnosis/epidemiology ; Dogs ; Humans ; Islands ; Italy ; Phylogeny ; Seroepidemiologic Studies ; *Zoonoses/diagnosis/parasitology ; }, abstract = {Dirofilariosis by Dirofilaria immitis and Dirofilaria repens is endemic in dogs from countries of the Mediterranean basin. Both species may infect humans, with most of the infected patients remaining asymptomatic. Based on the recent description of the southernmost hyperendemic European focus of heartworm disease in dogs from the Pelagie archipelagos, we performed a serological and molecular survey in human population of that area. Human blood samples were collected in the islands of Linosa (n=101) and Lampedusa (n=296) and tested by ELISA and molecular test for the detection of D. immitis and D. repens. Samples were also screened for filarioid-associated endosymbionts, Wolbachia sp. The seroprevalence of D. immitis and D. repens was, respectively, 7.9% and 3.96% in Linosa, and 7.77% and 19.93% in Lampedusa. Out of 397 human blood samples tested molecularly, 4 scored positive (1%) for Dirofilaria spp. by qPCR (i.e., three for D. immitis and one for D. repens) and 6 (1.5%) for Wolbachia. Of the qPCR positive for Dirofilaria spp., only D. repens was amplified by cPCR and was positive for Wolbachia. In the phylogenetic analysis, the sequence of Wolbachia detected in D. repens positive samples clustered along with other C supergroup filarioids. Our results overlap with the recent prevalence data collected on dogs from the same area, where D. immitis is prevalent in Linosa and D. repens prevails in Lampedusa. Molecular detection of D. immitis in human blood is quite unusual considering that humans are dead-end hosts for dirofilarial infection and most of the human cases described so far in Europe were ascribed to D. repens. An integrative diagnostic approach using serum analysis and Wolbachia detection is also presented. In endemic areas for canine dirofilarioses humans are exposed to the infection, suggesting the importance of One Health approach in diagnosing, treating and controlling this zoonotic parasitosis.}, }
@article {pmid34357349, year = {2021}, author = {Bellés-Sancho, P and Lardi, M and Liu, Y and Eberl, L and Zamboni, N and Bailly, A and Pessi, G}, title = {Metabolomics and Dual RNA-Sequencing on Root Nodules Revealed New Cellular Functions Controlled by Paraburkholderia phymatum NifA.}, journal = {Metabolites}, volume = {11}, number = {7}, pages = {}, pmid = {34357349}, issn = {2218-1989}, abstract = {Paraburkholderia phymatum STM815 is a nitrogen-fixing endosymbiont that nodulate the agriculturally important Phaseolus vulgaris and several other host plants. We previously showed that the nodules induced by a STM815 mutant of the gene encoding the master regulator of nitrogen fixation NifA showed no nitrogenase activity (Fix[-]) and increased in number compared to P. vulgaris plants infected with the wild-type strain. To further investigate the role of NifA during symbiosis, nodules from P. phymatum wild-type and nifA mutants were collected and analyzed by metabolomics and dual RNA-Sequencing, allowing us to investigate both host and symbiont transcriptome. Using this approach, several metabolites' changes could be assigned to bacterial or plant responses. While the amount of the C4-dicarboxylic acid succinate and of several amino acids was lower in Fix[-] nodules, the level of indole-acetamide (IAM) and brassinosteroids increased. Transcriptome analysis identified P. phymatum genes involved in transport of C4-dicarboxylic acids, carbon metabolism, auxin metabolism and stress response to be differentially expressed in absence of NifA. Furthermore, P. vulgaris genes involved in autoregulation of nodulation (AON) are repressed in nodules in absence of NifA potentially explaining the hypernodulation phenotype of the nifA mutant. These results and additional validation experiments suggest that P. phymatum STM815 NifA is not only important to control expression of nitrogenase and related enzymes but is also involved in regulating its own auxin production and stress response. Finally, our data indicate that P. vulgaris does sanction the nifA nodules by depleting the local carbon allocation rather than by mounting a strong systemic immune response to the Fix[-] rhizobia.}, }
@article {pmid34351459, year = {2021}, author = {Balaji, S and Deepthi, KNG and Prabagaran, SR}, title = {Native Wolbachia influence bacterial composition in the major vector mosquito Aedes aegypti.}, journal = {Archives of microbiology}, volume = {203}, number = {8}, pages = {5225-5240}, pmid = {34351459}, issn = {1432-072X}, mesh = {*Aedes ; Animals ; Female ; Mosquito Vectors ; RNA, Ribosomal, 16S/genetics ; *Wolbachia/genetics ; }, abstract = {Bacterial species that inhabit mosquito microbiota play an essential role in determining vector competence. In addition to critical factors such as host genotype, feeding habit and geography, intracellular endosymbiont Wolbachia pipientis modulates microbial composition considerably. In the present study, we assessed the midgut bacterial diversity of Aedes aegypti mosquitoes that is either naturally carrying Wolbachia (wAegB[+]) or antibiotic cured (wAegB[-]) through a culture-independent approach. Towards this, 16S rRNA gene libraries were constructed from midgut bacterial DNA of laboratory-reared larvae and adult female mosquitoes fed with sugar or blood. Among them 33 genera comprising 65 distinct species were identified, where > 75% of bacterial taxa were commonly shared by both groups (wAegB[+] and wAegB[-]), implying a subtle shift in the bacterial composition influenced by Wolbachia. Though the change was mostly restricted to minimally represented species, predominant taxa were observed unaltered except for certain genera. While Serratia sp. was abundant in Wolbachia carrying mosquitoes, Pseudomonas sp. and Acinetobacter sp. were predominant in Wolbachia free mosquitoes. This result demonstrates the influence of Wolbachia that could modulate the colonization of certain resident bacterial taxa through competitive interactions. Overall, this study shed more light on the impact of wAegB in altering the gut microbiota of Ae. aegypti mosquito, which might challenge host fitness and vector competence.}, }
@article {pmid34349742, year = {2021}, author = {Zhang, Y and Liu, S and Jiang, R and Zhang, C and Gao, T and Wang, Y and Liu, C and Long, Y and Zhang, Y and Yang, Y}, title = {Wolbachia Strain wGri From the Tea Geometrid Moth Ectropis grisescens Contributes to Its Host's Fecundity.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {694466}, pmid = {34349742}, issn = {1664-302X}, abstract = {Members of the Wolbachia genus manipulate insect-host reproduction and are the most abundant bacterial endosymbionts of insects. The tea Geometrid moth Ectropis grisescens (Warren) (Lepidoptera: Geometridae) is the most devastating insect pest of tea plants [Camellia sinensis (L.) O. Kuntze] in China. However, limited data on the diversity, typing, or phenotypes of Wolbachia in E. grisescens are available. Here, we used a culture-independent method to compare the gut bacteria of E. grisescens and other tea Geometridae moths. The results showed that the composition of core gut bacteria in larvae of the three Geometridae moth species was similar, except for the presence of Wolbachia. Moreover, Wolbachia was also present in adult female E. grisescens samples. A Wolbachia strain was isolated from E. grisescens and designated as wGri. Comparative analyses showed that this strain shared multilocus sequence types and Wolbachia surface protein hypervariable region profiles with cytoplasmic incompatibility (CI)-inducing strains in supergroup B; however, the wGri-associated phenotypes were undetermined. A reciprocal cross analysis showed that Wolbachia-uninfected females mated with infected males resulted in 100% embryo mortality (0% eggs hatched per female). Eggs produced by mating between uninfected males and infected females hatched normally. These findings indicated that wGri induces strong unidirectional CI in E. grisescens. Additionally, compared with uninfected females, Wolbachia-infected females produced approximately 30-40% more eggs. Together, these results show that this Wolbachia strain induces reproductive CI in E. grisescens and enhances the fecundity of its female host. We also demonstrated that wGri potential influences reproductive communication between E. grisescens and Ectropis obliqua through CI.}, }
@article {pmid34349734, year = {2021}, author = {Herrera, M and Liew, YJ and Venn, A and Tambutté, E and Zoccola, D and Tambutté, S and Cui, G and Aranda, M}, title = {New Insights From Transcriptomic Data Reveal Differential Effects of CO2 Acidification Stress on Photosynthesis of an Endosymbiotic Dinoflagellate in hospite.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {666510}, pmid = {34349734}, issn = {1664-302X}, abstract = {Ocean acidification (OA) has both detrimental as well as beneficial effects on marine life; it negatively affects calcifiers while enhancing the productivity of photosynthetic organisms. To date, many studies have focused on the impacts of OA on calcification in reef-building corals, a process particularly susceptible to acidification. However, little is known about the effects of OA on their photosynthetic algal partners, with some studies suggesting potential benefits for symbiont productivity. Here, we investigated the transcriptomic response of the endosymbiont Symbiodinium microadriaticum (CCMP2467) in the Red Sea coral Stylophora pistillata subjected to different long-term (2 years) OA treatments (pH 8.0, 7.8, 7.4, 7.2). Transcriptomic analyses revealed that symbionts from corals under lower pH treatments responded to acidification by increasing the expression of genes related to photosynthesis and carbon-concentrating mechanisms. These processes were mostly up-regulated and associated metabolic pathways were significantly enriched, suggesting an overall positive effect of OA on the expression of photosynthesis-related genes. To test this conclusion on a physiological level, we analyzed the symbiont's photochemical performance across treatments. However, in contrast to the beneficial effects suggested by the observed gene expression changes, we found significant impairment of photosynthesis with increasing pCO2. Collectively, our data suggest that over-expression of photosynthesis-related genes is not a beneficial effect of OA but rather an acclimation response of the holobiont to different water chemistries. Our study highlights the complex effects of ocean acidification on these symbiotic organisms and the role of the host in determining symbiont productivity and performance.}, }
@article {pmid34346878, year = {2021}, author = {Karatepe, M and Aksoy, S and Karatepe, B}, title = {Wolbachia spp. and Spiroplasma spp. in Musca spp.: Detection Using Molecular Approaches.}, journal = {Turkiye parazitolojii dergisi}, volume = {45}, number = {3}, pages = {211-215}, doi = {10.4274/tpd.galenos.2021.35229}, pmid = {34346878}, issn = {2146-3077}, mesh = {Animals ; Female ; Male ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; *Spiroplasma/genetics ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {OBJECTIVE: This study aimed to detect the presence of Wolbachia and Spiroplasma endosymbionts in Musca flies through molecular approaches.<br><br>METHODS: In total, 40 Musca spp. (20 female and 20 male) were used. Before DNA extraction, the flies were dissected and their heads, wings and legs were detached from their bodies under a stereomicroscope. Genomic DNA was analysed by standard polymerase chain reaction (PCR) using primers against Musca beta-tubulin. Afterward, the samples were examined for the presence of Wolbachia spp. using primers against Wolbachia wsp and GroEL. Furthermore, the DNA samples were analysed by PCR to detect the presence of Spiroplasma using primers against the 16S rRNA.<br><br>RESULTS: No Wolbachia positivity was detected in Musca flies, as shown by the negative PCR results for wsp and GroEL. Spiroplasma positivity was detected in 5% (1/20) of the female Musca flies but not in the male flies (0/20).<br><br>CONCLUSION: Wolbachia spp. were not detected in Musca flies. Of the total Musca flies, only one was positive for Spiroplasma spp. To our knowledge, this is the first study to detect the presence of Spiroplasma in Musca flies.}, }
@article {pmid34339868, year = {2021}, author = {Hilander, T and Jackson, CB and Robciuc, M and Bashir, T and Zhao, H}, title = {The roles of assembly factors in mammalian mitoribosome biogenesis.}, journal = {Mitochondrion}, volume = {60}, number = {}, pages = {70-84}, doi = {10.1016/j.mito.2021.07.008}, pmid = {34339868}, issn = {1872-8278}, mesh = {Animals ; *Genome, Mitochondrial ; Mammals/*genetics/*physiology ; Mitochondrial Ribosomes/*physiology ; }, abstract = {As ancient bacterial endosymbionts of eukaryotic cells, mitochondria have retained their own circular DNA as well as protein translation system including mitochondrial ribosomes (mitoribosomes). In recent years, methodological advancements in cryoelectron microscopy and mass spectrometry have revealed the extent of the evolutionary divergence of mitoribosomes from their bacterial ancestors and their adaptation to the synthesis of 13 mitochondrial DNA encoded oxidative phosphorylation complex subunits. In addition to the structural data, the first assembly pathway maps of mitoribosomes have started to emerge and concomitantly also the assembly factors involved in this process to achieve fully translational competent particles. These transiently associated factors assist in the intricate assembly process of mitoribosomes by enhancing protein incorporation, ribosomal RNA folding and modification, and by blocking premature or non-native protein binding, for example. This review focuses on summarizing the current understanding of the known mammalian mitoribosome assembly factors and discussing their possible roles in the assembly of small or large mitoribosomal subunits.}, }
@article {pmid34335311, year = {2021}, author = {Yue, L and Guan, Z and Zhong, M and Zhao, L and Pang, R and Liu, K}, title = {Genome-Wide Identification and Characterization of Amino Acid Polyamine Organocation Transporter Family Genes Reveal Their Role in Fecundity Regulation in a Brown Planthopper Species (Nilaparvata lugens).}, journal = {Frontiers in physiology}, volume = {12}, number = {}, pages = {708639}, pmid = {34335311}, issn = {1664-042X}, abstract = {The brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera:Delphacidae), is one of the most destructive pests of rice worldwide. As a sap-feeding insect, the BPH is incapable of synthesizing several amino acids which are essential for normal growth and development. Therefore, the insects have to acquire these amino acids from dietary sources or their endosymbionts, in which amino acid transporters (AATs) play a crucial role by enabling the movement of amino acids into and out of insect cells. In this study, a common amino acid transporter gene family of amino acid/polyamine/organocation (APC) was identified in BPHs and analyzed. Based on a homology search and conserved functional domain recognition, 20 putative APC transporters were identified in the BPH genome. Molecular trait analysis showed that the verified BPH APC family members were highly variable in protein features, conserved motif distribution patterns, and exon/intron organization. Phylogenetic analysis of five hemipteran species revealed an evolutionary pattern of interfamily conservation and lineage-specific expansion of this gene family. Moreover, stage- and tissue-specific expression analysis revealed diverse expression patterns in the 20 BPH APC transporter genes. Lastly, a potential BPH fecundity regulatory gene of NlAPC09 was identified and shown to participate in the fecundity regulation through the use of quantitative polymerase chain reaction (qPCR) and RNA inference experiments. Our results provide a basis for further functional investigations of APC transporters in BPH.}, }
@article {pmid34329639, year = {2021}, author = {Cirino, L and Tsai, S and Wen, ZH and Wang, LH and Chen, HK and Cheng, JO and Lin, C}, title = {Lipid profiling in chilled coral larvae.}, journal = {Cryobiology}, volume = {102}, number = {}, pages = {56-67}, doi = {10.1016/j.cryobiol.2021.07.012}, pmid = {34329639}, issn = {1090-2392}, mesh = {Animals ; *Anthozoa ; Coral Reefs ; Cryopreservation/methods ; Ecosystem ; Humans ; Larva ; Lipids ; }, abstract = {Coral reefs are disappearing worldwide as a result of several harmful human activities. The establishment of cryobanks can secure a future for these ecosystems. To design effective cryopreservation protocols, basic proprieties such as chilling tolerance and lipid content must be assessed. In the present study, we investigated chilling sensitivity and the effect of chilling exposure on the lipid content and composition of larvae belonging to 2 common Indo-Pacific corals: Seriatopora caliendrum and Pocillopora verrucosa. The viability of coral larvae incubated with 0.5, 1, and 2 M ethylene glycol (EG), propylene glycol (PG), dimethyl sulfoxide (Me2SO), methanol, or glycerol and kept at 5 °C for different time periods was documented. In addition, we investigated the content of cholesterol, triacylglycerol (TAG), wax ester (WE), sterol ester (SE), lysophosphatidylcholine, phosphatidylcholine, phosphatidylethanolamine, and several fatty acid (FA) classes in coral propagules incubated with 1 M PG or EG and kept at 5 °C for 6 h. Moreover, we examined seasonal changes in the aforementioned lipid classes in coral larvae. S. caliendrum incubated with 0.5 M PG or Me2SO and chilled for 2 h exhibited a viability rate of 11 ± 11%, whereas P. verrucosa exhibited a viability rate of 22 ± 14% after being chilled for 4 h. Furthermore, the results indicated that chilling exposure did not affect the content of any investigated lipid class in either species. The higher concentration of SE in P. verrucosa compared to S. caliendrum larvae may have contributed to the different cryotolerance displayed by the 2 larval species. A year-round lipid analysis of both coral larvae species revealed trends of homeoviscous adaptation and seasonal enhancement of lipid fluxes from symbionts to the host. During winter, the cholesterol/phospholipid ratio significantly increased, and P. verrucosa larvae exhibited an averagely decrease in FA chain lengths. During spring and summer, intracellular lipid content in the form of TAGs and WEs significantly increased in both species, and the average content of Symbiodiniaceae-derived FAs increased in P. verrucosa larvae. We concluded that the low cryotolerance displayed by S. caliendrum and P. verrucosa larvae is attributable to their chilling-sensitive membrane lipid profile and the high intracellular lipid content provided by their endosymbionts.}, }
@article {pmid34328183, year = {2022}, author = {Koskimäki, JJ and Pohjanen, J and Kvist, J and Fester, T and Härtig, C and Podolich, O and Fluch, S and Edesi, J and Häggman, H and Pirttilä, AM}, title = {The meristem-associated endosymbiont Methylorubrum extorquens DSM13060 reprograms development and stress responses of pine seedlings.}, journal = {Tree physiology}, volume = {42}, number = {2}, pages = {391-410}, pmid = {34328183}, issn = {1758-4469}, mesh = {Endophytes/physiology ; Meristem ; *Pinus/genetics ; *Pinus sylvestris ; Seedlings ; }, abstract = {Microbes living in plant tissues-endophytes-are mainly studied in crop plants where they typically colonize the root apoplast. Trees-a large carbon source with a high capacity for photosynthesis-provide a variety of niches for endophytic colonization. We have earlier identified a new type of plant-endophyte interaction in buds of adult Scots pine, where Methylorubrum species live inside the meristematic cells. The endosymbiont Methylorubrum extorquens DSM13060 significantly increases needle and root growth of pine seedlings without producing plant hormones, but by aggregating around host nuclei. Here, we studied gene expression and metabolites of the pine host induced by M. extorquens DSM13060 infection. Malic acid was produced by pine to potentially boost M. extorquens colonization and interaction. Based on gene expression, the endosymbiont activated the auxin- and ethylene (ET)-associated hormonal pathways through induction of CUL1 and HYL1, and suppressed salicylic and abscisic acid signaling of pine. Infection by the endosymbiont had an effect on pine meristem and leaf development through activation of GLP1-7 and ALE2, and suppressed flowering, root hair and lateral root formation by downregulation of AGL8, plantacyanin, GASA7, COW1 and RALFL34. Despite of systemic infection of pine seedlings by the endosymbiont, the pine genes CUL1, ETR2, ERF3, HYL, GLP1-7 and CYP71 were highly expressed in the shoot apical meristem, rarely in needles and not in stem or root tissues. Low expression of MERI5, CLH2, EULS3 and high quantities of ononitol suggest that endosymbiont promotes viability and protects pine seedlings against abiotic stress. Our results indicate that the endosymbiont positively affects host development and stress tolerance through mechanisms previously unknown for endophytic bacteria, manipulation of plant hormone signaling pathways, downregulation of senescence and cell death-associated genes and induction of ononitol biosynthesis.}, }
@article {pmid34327796, year = {2021}, author = {Orlofsky, E and Zabari, L and Bonito, G and Masaphy, S}, title = {Changes in soil bacteria functional ecology associated with Morchella rufobrunnea fruiting in a natural habitat.}, journal = {Environmental microbiology}, volume = {23}, number = {11}, pages = {6651-6662}, doi = {10.1111/1462-2920.15692}, pmid = {34327796}, issn = {1462-2920}, mesh = {Ascomycota ; Bacteria/genetics ; *Microbiota/genetics ; RNA, Ribosomal, 16S/genetics ; *Soil ; Soil Microbiology ; }, abstract = {Morchella rufobrunnea is a saprobic edible mushroom, found in a range of ecological niches, indicating nutritional adjustment to different habitats and possible interaction with soil prokaryotic microbiome (SPM). Using the 16S rRNA gene, we examined the SPM of M. rufobrunnea that appeared in a natural habitat in Northern Israel. Three sample types were included: bare soil without mushroom, soil beneath young mushroom initials and soil beneath the mature fruiting body. Morchella rufobrunnea developmental stage was significantly associated with changes in bacterial populations (PERMANOVA, p < 0.0005). Indicator analysis with point-biserial correlation coefficient found 180 operational taxonomic units (OTU) uniquely associated with distinct stages of development. The Functional Annotation of Prokaryotic Taxonomy (FAPROTAX) database helped to infer ecological roles for indicator OTU. The functional ecological progression begins with establishment of a photoautotrophic N-fixing bacterial mat on bare soil. Pioneer heterotrophs including oligotrophs, acidifying nutrient mobilizers and nitrifiers are congruent with appearance of young M. rufobrunnea initials. Under the mature fruiting body, the population changed to saprobes, organic-N degraders, denitrifiers, insect endosymbionts and fungal antagonists. Based on this work, M. rufobrunnea may be able to influence SPM and change the soil nutritional profile.}, }
@article {pmid34326342, year = {2021}, author = {Wang, B and Lin, YC and Vasquez-Rifo, A and Jo, J and Price-Whelan, A and McDonald, ST and Brown, LM and Sieben, C and Dietrich, LEP}, title = {Pseudomonas aeruginosa PA14 produces R-bodies, extendable protein polymers with roles in host colonization and virulence.}, journal = {Nature communications}, volume = {12}, number = {1}, pages = {4613}, pmid = {34326342}, issn = {2041-1723}, support = {R01 AI103369/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics/*metabolism ; Biofilms/growth &amp; development ; Caenorhabditis elegans ; Phylogeny ; Pseudomonas Infections/genetics/metabolism/*microbiology ; Pseudomonas aeruginosa/cytology/genetics/*metabolism/*pathogenicity ; Virulence ; Virulence Factors/genetics/*metabolism ; }, abstract = {R-bodies are long, extendable protein polymers formed in the cytoplasm of some bacteria; they are best known for their role in killing of paramecia by bacterial endosymbionts. Pseudomonas aeruginosa PA14, an opportunistic pathogen of diverse hosts, contains genes (referred to as the reb cluster) with potential to confer production of R-bodies and that have been implicated in virulence. Here, we show that products of the PA14 reb cluster associate with R-bodies and control stochastic expression of R-body structural genes. PA14 expresses reb genes during colonization of plant and nematode hosts, and R-body production is required for full virulence in nematodes. Analyses of nematode ribosome content and immune response indicate that P. aeruginosa R-bodies act via a mechanism involving ribosome cleavage and translational inhibition. Our observations provide insight into the biology of R-body production and its consequences during P. aeruginosa infection.}, }
@article {pmid34324610, year = {2021}, author = {Rothman, JA and Loope, KJ and McFrederick, QS and Wilson Rankin, EE}, title = {Microbiome of the wasp Vespula pensylvanica in native and invasive populations, and associations with Moku virus.}, journal = {PloS one}, volume = {16}, number = {7}, pages = {e0255463}, pmid = {34324610}, issn = {1932-6203}, mesh = {Animals ; *Bees ; RNA Viruses ; *RNA, Ribosomal, 16S ; *Wasps ; }, abstract = {Invasive species present a worldwide concern as competition and pathogen reservoirs for native species. Specifically, the invasive social wasp, Vespula pensylvanica, is native to western North America and has become naturalized in Hawaii, where it exerts pressures on native arthropod communities as a competitor and predator. As invasive species may alter the microbial and disease ecology of their introduced ranges, there is a need to understand the microbiomes and virology of social wasps. We used 16S rRNA gene sequencing to characterize the microbiome of V. pensylvanica samples pooled by colony across two geographically distinct ranges and found that wasps generally associate with taxa within the bacterial genera Fructobacillus, Fructilactobacillus, Lactococcus, Leuconostoc, and Zymobacter, and likely associate with environmentally-acquired bacteria. Furthermore, V. pensylvanica harbors-and in some cases were dominated by-many endosymbionts including Wolbachia, Sodalis, Arsenophonus, and Rickettsia, and were found to contain bee-associated taxa, likely due to scavenging on or predation upon honey bees. Next, we used reverse-transcriptase quantitative PCR to assay colony-level infection intensity for Moku virus (family: Iflaviridae), a recently-described disease that is known to infect multiple Hymenopteran species. While Moku virus was prevalent and in high titer, it did not associate with microbial diversity, indicating that the microbiome may not directly interact with Moku virus in V. pensylvanica in meaningful ways. Collectively, our results suggest that the invasive social wasp V. pensylvanica associates with a simple microbiome, may be infected with putative endosymbionts, likely acquires bacterial taxa from the environment and diet, and is often infected with Moku virus. Our results suggest that V. pensylvanica, like other invasive social insects, has the potential to act as a reservoir for bacteria pathogenic to other pollinators, though this requires experimental demonstration.}, }
@article {pmid34324516, year = {2021}, author = {Rangel-Chávez, CP and Galán-Vásquez, E and Pescador-Tapia, A and Delaye, L and Martínez-Antonio, A}, title = {RNA polymerases in strict endosymbiont bacteria with extreme genome reduction show distinct erosions that might result in limited and differential promoter recognition.}, journal = {PloS one}, volume = {16}, number = {7}, pages = {e0239350}, pmid = {34324516}, issn = {1932-6203}, mesh = {DNA-Directed RNA Polymerases/*metabolism ; Escherichia coli/genetics/metabolism ; Genome, Bacterial/*genetics ; Promoter Regions, Genetic/*genetics ; *Symbiosis ; }, abstract = {Strict endosymbiont bacteria present high degree genome reduction, retain smaller proteins, and in some instances, lack complete functional domains compared to free-living counterparts. Until now, the mechanisms underlying these genetic reductions are not well understood. In this study, the conservation of RNA polymerases, the essential machinery for gene expression, is analyzed in endosymbiont bacteria with extreme genome reductions. We analyzed the RNA polymerase subunits to identify and define domains, subdomains, and specific amino acids involved in precise biological functions known in Escherichia coli. We also perform phylogenetic analysis and three-dimensional models over four lineages of endosymbiotic proteobacteria with the smallest genomes known to date: Candidatus Hodgkinia cicadicola, Candidatus Tremblaya phenacola, Candidatus Tremblaya Princeps, Candidatus Nasuia deltocephalinicola, and Candidatus Carsonella ruddii. We found that some Hodgkinia strains do not encode for the RNA polymerase α subunit. The rest encode genes for α, β, β', and σ subunits to form the RNA polymerase. However, 16% shorter, on average, respect their orthologous in E. coli. In the α subunit, the amino-terminal domain is the most conserved. Regarding the β and β' subunits, both the catalytic core and the assembly domains are the most conserved. However, they showed compensatory amino acid substitutions to adapt to changes in the σ subunit. Precisely, the most erosive diversity occurs within the σ subunit. We identified broad amino acid substitution even in those recognizing and binding to the -10-box promoter element. In an overall conceptual image, the RNA polymerase from Candidatus Nasuia conserved the highest similarity with Escherichia coli RNA polymerase and their σ70. It might be recognizing the two main promoter elements (-10 and -35) and the two promoter accessory elements (-10 extended and UP-element). In Candidatus Carsonella, the RNA polymerase could recognize all the promoter elements except the -10-box extended. In Candidatus Tremblaya and Hodgkinia, due to the α carboxyl-terminal domain absence, they might not recognize the UP-promoter element. We also identified the lack of the β flap-tip helix domain in most Hodgkinia's that suggests the inability to bind the -35-box promoter element.}, }
@article {pmid34322098, year = {2021}, author = {Stravoravdis, S and Shipway, JR and Goodell, B}, title = {How Do Shipworms Eat Wood? Screening Shipworm Gill Symbiont Genomes for Lignin-Modifying Enzymes.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {665001}, pmid = {34322098}, issn = {1664-302X}, abstract = {Shipworms are ecologically and economically important mollusks that feed on woody plant material (lignocellulosic biomass) in marine environments. Digestion occurs in a specialized cecum, reported to be virtually sterile and lacking resident gut microbiota. Wood-degrading CAZymes are produced both endogenously and by gill endosymbiotic bacteria, with extracellular enzymes from the latter being transported to the gut. Previous research has predominantly focused on how these animals process the cellulose component of woody plant material, neglecting the breakdown of lignin - a tough, aromatic polymer which blocks access to the holocellulose components of wood. Enzymatic or non-enzymatic modification and depolymerization of lignin has been shown to be required in other wood-degrading biological systems as a precursor to cellulose deconstruction. We investigated the genomes of five shipworm gill bacterial symbionts obtained from the Joint Genome Institute Integrated Microbial Genomes and Microbiomes Expert Review for the production of lignin-modifying enzymes, or ligninases. The genomes were searched for putative ligninases using the Joint Genome Institute's Function Profile tool and blastp analyses. The resulting proteins were then modeled using SWISS-MODEL. Although each bacterial genome possessed at least four predicted ligninases, the percent identities and protein models were of low quality and were unreliable. Prior research demonstrates limited endogenous ability of shipworms to modify lignin at the chemical/molecular level. Similarly, our results reveal that shipworm bacterial gill-symbiont enzymes are unlikely to play a role in lignin modification during lignocellulose digestion in the shipworm gut. This suggests that our understanding of how these keystone organisms digest and process lignocellulose is incomplete, and further research into non-enzymatic and/or other unknown mechanisms for lignin modification is required.}, }
@article {pmid34315897, year = {2021}, author = {Zhang, M and Wang, C and Oberstaller, J and Thomas, P and Otto, TD and Casandra, D and Boyapalle, S and Adapa, SR and Xu, S and Button-Simons, K and Mayho, M and Rayner, JC and Ferdig, MT and Jiang, RHY and Adams, JH}, title = {The apicoplast link to fever-survival and artemisinin-resistance in the malaria parasite.}, journal = {Nature communications}, volume = {12}, number = {1}, pages = {4563}, pmid = {34315897}, issn = {2041-1723}, support = {F31 AI083053/AI/NIAID NIH HHS/United States ; F32 AI112271/AI/NIAID NIH HHS/United States ; 098051/WT_/Wellcome Trust/United Kingdom ; R01 AI130171/AI/NIAID NIH HHS/United States ; R01 AI094973/AI/NIAID NIH HHS/United States ; R01 AI117017/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Apicoplasts/drug effects/*metabolism ; Artemisinins/*pharmacology ; *Drug Resistance/drug effects ; Fever/*parasitology ; Gene Expression Regulation/drug effects ; Heat-Shock Response/drug effects ; Malaria, Falciparum/*parasitology ; Mutation/genetics ; Parasites/drug effects/*physiology ; Phenotype ; Plasmodium falciparum/genetics ; Signal Transduction/drug effects ; Temperature ; Terpenes/metabolism ; Transcription, Genetic/drug effects ; Unfolded Protein Response/drug effects ; }, abstract = {The emergence and spread of Plasmodium falciparum parasites resistant to front-line antimalarial artemisinin-combination therapies (ACT) threatens to erase the considerable gains against the disease of the last decade. Here, we develop a large-scale phenotypic screening pipeline and use it to carry out a large-scale forward-genetic phenotype screen in P. falciparum to identify genes allowing parasites to survive febrile temperatures. Screening identifies more than 200 P. falciparum mutants with differential responses to increased temperature. These mutants are more likely to be sensitive to artemisinin derivatives as well as to heightened oxidative stress. Major processes critical for P. falciparum tolerance to febrile temperatures and artemisinin include highly essential, conserved pathways associated with protein-folding, heat shock and proteasome-mediated degradation, and unexpectedly, isoprenoid biosynthesis, which originated from the ancestral genome of the parasite's algal endosymbiont-derived plastid, the apicoplast. Apicoplast-targeted genes in general are upregulated in response to heat shock, as are other Plasmodium genes with orthologs in plant and algal genomes. Plasmodium falciparum parasites appear to exploit their innate febrile-response mechanisms to mediate resistance to artemisinin. Both responses depend on endosymbiont-derived genes in the parasite's genome, suggesting a link to the evolutionary origins of Plasmodium parasites in free-living ancestors.}, }
@article {pmid34312980, year = {2021}, author = {Herran, B and Houdelet, C and Raimond, M and Delaunay, C and Cerveau, N and Debenest, C and Grève, P and Bertaux, J}, title = {Feminising Wolbachia disrupt Armadillidium vulgare insulin-like signalling pathway.}, journal = {Cellular microbiology}, volume = {23}, number = {11}, pages = {e13381}, doi = {10.1111/cmi.13381}, pmid = {34312980}, issn = {1462-5822}, mesh = {Animals ; Female ; Feminization ; Humans ; Insulin ; *Isopoda ; Male ; Signal Transduction ; *Wolbachia/genetics ; }, abstract = {The endosymbiont Wolbachia feminises male isopods by making them refractory to the insulin-like masculinising hormone, which shunts the autocrine development of the androgenic glands. It was, therefore, proposed that Wolbachia silences the IR receptors, either by preventing their expression or by inactivating them. We describe here the two IR paralogs of Armadillidium vulgare. They displayed a conventional structure and belonged to a family widespread among isopods. Av-IR1 displayed an ubiquist expression, whereas the expression of Av-IR2 was restricted to the gonads. Both were constitutively expressed in males and females and throughout development. However, upon silencing, altered gland physiology and gene expression therein suggested antagonistic roles for Av-IR1 (androinhibiting) and Av-IR2 (androstimulating). They may function in tandem with regulating neurohormones, as a conditional platform that conveys insulin signalling. Wolbachia infection did not alter their expression patterns: leaving the IRs unscathed, the bacteria would suppress the secretion of the neurohormones, thus inducing body-wide IR deactivation and feminisation. Adult males injected with Wolbachia acquired an intersexed physiology. Their phenotypes and gene expressions mirrored the silencing of Av-IR1 only, suggesting that imperfect feminisation stems from a flawed invasion of the androstimulating centre, whereas in fully feminised males invasion would be complete in early juveniles. TAKE AWAY: Two antagonistic Insulin Receptors were characterised in Armadillidium vulgare. The IRs were involved in androstimulating and androinhibiting functions. Wolbachia-induced feminisation did not prevent the expression of the IRs. Imperfectly feminised intersexes phenocopied the silencing of Av-IR1 only. Wolbachia would deactivate the IRs by suppressing neurosecretory co-factors.}, }
@article {pmid34311584, year = {2021}, author = {Atwal, S and Chuenklin, S and Bonder, EM and Flores, J and Gillespie, JJ and Driscoll, TP and Salje, J}, title = {Discovery of a Diverse Set of Bacteria That Build Their Cell Walls without the Canonical Peptidoglycan Polymerase aPBP.}, journal = {mBio}, volume = {12}, number = {4}, pages = {e0134221}, pmid = {34311584}, issn = {2150-7511}, support = {R01 AI043006/AI/NIAID NIH HHS/United States ; R01 AI152219/AI/NIAID NIH HHS/United States ; R21 AI146773/AI/NIAID NIH HHS/United States ; R56 AI148645/AI/NIAID NIH HHS/United States ; R21 AI156762/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; 220211/WT_/Wellcome Trust/United Kingdom ; R21 AI052108/AI/NIAID NIH HHS/United States ; R21 AI144385/AI/NIAID NIH HHS/United States ; }, mesh = {Bacterial Proteins/genetics/*metabolism ; Biosynthetic Pathways ; Cell Division ; Cell Wall/*metabolism ; Humans ; Penicillin-Binding Proteins/classification/genetics/*metabolism ; Peptidoglycan/*metabolism ; Rickettsiaceae/classification/*enzymology/genetics/*metabolism ; }, abstract = {Peptidoglycan (PG) is a highly cross-linked peptide-glycan mesh that confers structural rigidity and shape to most bacterial cells. Polymerization of new PG is usually achieved by the concerted activity of two membrane-bound machineries, class-A penicillin binding proteins (aPBPs) and class-B penicillin binding proteins (bPBPs) in complex with shape, elongation, division, and sporulation (SEDS) proteins. Here, we have identified four phylogenetically distinct groups of bacteria that lack any identifiable aPBPs. We performed experiments on a panel of species within one of these groups, the Rickettsiales, and found that bacteria lacking aPBPs build a PG-like cell wall with minimal abundance and rigidity relative to cell walls of aPBP-containing bacteria. This reduced cell wall may have evolved to minimize the activation of host responses to pathogens and endosymbionts while retaining the minimal PG-biosynthesis machinery required for cell elongation and division. We term these "peptidoglycan-intermediate" bacteria, a cohort of host-associated species that includes some human pathogens. IMPORTANCE Peptidoglycan (PG) is a large, cross-linked polymer that forms the cell wall of most bacterial species and confers shape, rigidity, and protection from osmotic shock. It is also a potent stimulator of the immune response in animals. PG is normally polymerized by two groups of enzymes, aPBPs and bPBPs working together with shape, elongation, division, and sporulation (SEDS) proteins. We have identified a diverse set of host-associated bacteria that have selectively lost aPBP genes while retaining bPBP/SEDS and show that some of these build a minimal PG-like structure. It is expected that these minimal cell walls built in the absence of aPBPs improve the evolutionary fitness of host-associated bacteria, potentially through evasion of PG-recognition by the host immune system.}, }
@article {pmid34311575, year = {2021}, author = {Nicoud, Q and Barrière, Q and Busset, N and Dendene, S and Travin, D and Bourge, M and Le Bars, R and Boulogne, C and Lecroël, M and Jenei, S and Kereszt, A and Kondorosi, E and Biondi, EG and Timchenko, T and Alunni, B and Mergaert, P}, title = {Sinorhizobium meliloti Functions Required for Resistance to Antimicrobial NCR Peptides and Bacteroid Differentiation.}, journal = {mBio}, volume = {12}, number = {4}, pages = {e0089521}, pmid = {34311575}, issn = {2150-7511}, mesh = {Antimicrobial Peptides/genetics/*metabolism/*pharmacology ; *Drug Resistance, Bacterial ; Medicago truncatula/*chemistry/microbiology ; Nitrogen Fixation ; Root Nodules, Plant/microbiology ; Sinorhizobium meliloti/*drug effects/genetics/*metabolism ; Symbiosis ; }, abstract = {Legumes of the Medicago genus have a symbiotic relationship with the bacterium Sinorhizobium meliloti and develop root nodules housing large numbers of intracellular symbionts. Members of the nodule-specific cysteine-rich peptide (NCR) family induce the endosymbionts into a terminal differentiated state. Individual cationic NCRs are antimicrobial peptides that have the capacity to kill the symbiont, but the nodule cell environment prevents killing. Moreover, the bacterial broad-specificity peptide uptake transporter BacA and exopolysaccharides contribute to protect the endosymbionts against the toxic activity of NCRs. Here, we show that other S. meliloti functions participate in the protection of the endosymbionts; these include an additional broad-specificity peptide uptake transporter encoded by the yejABEF genes and lipopolysaccharide modifications mediated by lpsB and lpxXL, as well as rpoH1, encoding a stress sigma factor. Strains with mutations in these genes show a strain-specific increased sensitivity profile against a panel of NCRs and form nodules in which bacteroid differentiation is affected. The lpsB mutant nodule bacteria do not differentiate, the lpxXL and rpoH1 mutants form some seemingly fully differentiated bacteroids, although most of the nodule bacteria are undifferentiated, while the yejABEF mutants form hypertrophied but nitrogen-fixing bacteroids. The nodule bacteria of all the mutants have a strongly enhanced membrane permeability, which is dependent on the transport of NCRs to the endosymbionts. Our results suggest that S. meliloti relies on a suite of functions, including peptide transporters, the bacterial envelope structures, and stress response regulators, to resist the aggressive assault of NCR peptides in the nodule cells. IMPORTANCE The nitrogen-fixing symbiosis of legumes with rhizobium bacteria has a predominant ecological role in the nitrogen cycle and has the potential to provide the nitrogen required for plant growth in agriculture. The host plants allow the rhizobia to colonize specific symbiotic organs, the nodules, in large numbers in order to produce sufficient reduced nitrogen for the plants' needs. Some legumes, including Medicago spp., produce massively antimicrobial peptides to keep this large bacterial population in check. These peptides, known as NCRs, have the potential to kill the rhizobia, but in nodules, they rather inhibit the division of the bacteria, which maintain a high nitrogen-fixing activity. In this study, we show that the tempering of the antimicrobial activity of the NCR peptides in the Medicago symbiont Sinorhizobium meliloti is multifactorial and requires the YejABEF peptide transporter, the lipopolysaccharide outer membrane, and the stress response regulator RpoH1.}, }
@article {pmid34308025, year = {2021}, author = {Neiers, F and Saliou, JM and Briand, L and Robichon, A}, title = {Adaptive Variation of Buchnera Endosymbiont Density in Aphid Host Acyrthosiphon pisum Controlled by Environmental Conditions.}, journal = {ACS omega}, volume = {6}, number = {28}, pages = {17902-17914}, pmid = {34308025}, issn = {2470-1343}, abstract = {The scarcity of transcriptional regulatory genes in Buchnera aphidicola, an obligate endosymbiont in aphids, suggests the stability of expressed gene patterns and metabolic pathways. This observation argues in favor of the hypothesis that this endosymbiont bacteria might contribute little to the host adaptation when aphid hosts are facing challenging fluctuating environment. Finding evidence for the increased expression or silenced genes involved in metabolic pathways under the pressure of stress conditions and/or a given environment has been challenging for experimenters with this bacterial symbiotic model. Transcriptomic data have shown that Buchnera gene expression changes are confined to a narrow range when the aphids face brutal environmental variations. In this report, we demonstrate that instead of manipulating individual genes, the conditions may act on the relative mass of endosymbiont corresponding to the needs of the host. The control of the fluctuating number of endosymbiont cells per individual host appears to be an unexpected regulatory modality that contributes to the adaptation of aphids to their environment. This feature may account for the success of the symbiotic advantages in overcoming the drastic changes in temperature and food supplies during evolution.}, }
@article {pmid34305877, year = {2021}, author = {Zhu, YX and Song, ZR and Zhang, YY and Hoffmann, AA and Hong, XY}, title = {Spider Mites Singly Infected With Either Wolbachia or Spiroplasma Have Reduced Thermal Tolerance.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {706321}, pmid = {34305877}, issn = {1664-302X}, abstract = {Heritable symbionts play an essential role in many aspects of host ecology in a temperature-dependent manner. However, how temperature impacts the host and their interaction with endosymbionts remains largely unknown. Here, we investigated the impact of moderate (20°C) and high (30 and 35°C) temperatures on symbioses between the spider mite Tetranychus truncatus and two maternally inherited endosymbionts (Wolbachia and Spiroplasma). We found that the thermal tolerance of mites (as measured by survival after heat exposure) was lower for mites that were singly infected with either Wolbachia or Spiroplasma than it was for co-infected or uninfected mites. Although a relatively high temperature (30°C) is thought to promote bacterial replication, rearing at high temperature (35°C) resulted in losses of Wolbachia and particularly Spiroplasma. Exposing the mites to 20°C reduced the density and transmission of Spiroplasma but not Wolbachia. The four spider mite strains tested differed in the numbers of heat shock genes (Hsps) induced under moderate or high temperature exposure. In thermal preference (Tp) assays, the two Wolbachia-infected spider mite strains preferred a lower temperature than strains without Wolbachia. Our results show that endosymbiont-mediated spider mite responses to temperature stress are complex, involving a combination of changing endosymbiont infection patterns, altered thermoregulatory behavior, and transcription responses.}, }
@article {pmid34295000, year = {2021}, author = {Cano-Calle, D and Saldamando-Benjumea, CI and Vivero-Gómez, RJ and Moreno-Herrera, CX and Arango-Isaza, RE}, title = {Two New Strains of Wolbachia Affecting Natural Avocado Thrips.}, journal = {Indian journal of microbiology}, volume = {61}, number = {3}, pages = {348-354}, pmid = {34295000}, issn = {0046-8991}, abstract = {UNLABELLED: Wolbachia is an obligate intracellular bacterium with a high frequency of infection and a continental distribution in arthropods and nematodes. This endosymbiont can induce various reproductive phenotypes in their hosts and has been previously found naturally in several pests including thrips (Thripidae). These insects cause physical fruit damage and economic losses in avocado. The presence of Wolbachia was evaluated for the first time in avocado thrips populations of Frankliniella sp. and Scirtothrips hansoni sp.n. from eastern Antioquia. DNA from adult thrips individuals was used to assess the detection of Wolbachia by amplifying a fragment (600 bp) of the Wolbachia major surface protein (wsp) gene. Results confirmed the presence of two new Wolbachia strains in these two thrips species, with a higher percentage of natural infection in S. hansoni sp.n. The first Wolbachia species was found in Frankliniella sp. and belongs to supergroup A and the second was detected in S. hansoni sp.n. and is part of supergroup B. Wolbachia was more frequently found in females (32.73%), and only found in one male. Analysis of phylogenetic relationships, suggests that the two new Wolbachia sequences (wFran: Frankliniella and wShan: Scirtothrips hansoni) detected here represent two new groups for this endosymbiont. The haplotype network shows the presence of two possible haplotypes for each strain. Future studies to evaluate the possible use of Wolbachia as a control agent in avocado thrips are necessary.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12088-021-00951-5.}, }
@article {pmid34294881, year = {2022}, author = {Szabó, G and Schulz, F and Manzano-Marín, A and Toenshoff, ER and Horn, M}, title = {Evolutionarily recent dual obligatory symbiosis among adelgids indicates a transition between fungus- and insect-associated lifestyles.}, journal = {The ISME journal}, volume = {16}, number = {1}, pages = {247-256}, pmid = {34294881}, issn = {1751-7370}, mesh = {Animals ; Fungi ; *Hemiptera/microbiology ; Insecta ; Phylogeny ; *Symbiosis/genetics ; }, abstract = {Adelgids (Insecta: Hemiptera: Adelgidae) form a small group of insects but harbor a surprisingly diverse set of bacteriocyte-associated endosymbionts, which suggest multiple replacement and acquisition of symbionts over evolutionary time. Specific pairs of symbionts have been associated with adelgid lineages specialized on different secondary host conifers. Using a metagenomic approach, we investigated the symbiosis of the Adelges laricis/Adelges tardus species complex containing betaproteobacterial ("Candidatus Vallotia tarda") and gammaproteobacterial ("Candidatus Profftia tarda") symbionts. Genomic characteristics and metabolic pathway reconstructions revealed that Vallotia and Profftia are evolutionary young endosymbionts, which complement each other's role in essential amino acid production. Phylogenomic analyses and a high level of genomic synteny indicate an origin of the betaproteobacterial symbiont from endosymbionts of Rhizopus fungi. This evolutionary transition was accompanied with substantial loss of functions related to transcription regulation, secondary metabolite production, bacterial defense mechanisms, host infection, and manipulation. The transition from fungus to insect endosymbionts extends our current framework about evolutionary trajectories of host-associated microbes.}, }
@article {pmid34293581, year = {2021}, author = {Krueger, S and Moritz, G}, title = {Sperm ultrastructure in arrhenotokous and thelytokous Thysanoptera.}, journal = {Arthropod structure &amp; development}, volume = {64}, number = {}, pages = {101084}, doi = {10.1016/j.asd.2021.101084}, pmid = {34293581}, issn = {1873-5495}, mesh = {Animals ; Female ; Insecta ; Male ; Parthenogenesis ; Reproduction ; Spermatozoa ; *Thysanoptera ; }, abstract = {Thysanoptera are haplo-diploid insects that reproduce either via arrhenotoky or thelytoky. Beside genetically based thelytoky, this reproduction mode can also be endosymbiont induced. The recovery of these females from their infection again leads to the development of males. Functionality of these males ranges widely, and this might be associated with sperm structure. We analyzed the sperm ultrastructure in three different species belonging to both suborders with different reproduction systems via electron microscopy. Beside the different reproduction modes, and adaptations to their life style, the arrhenotokous species Suocerathrips linguis (Thysanoptera: Tubulifera) and Echinothrips americanus (Thysanoptera: Terebrantia) possess typical thysanopteran-like sperm structure. But endosymbiont-cured males from the thelytokous species Hercinothrips femoralis (Thysanoptera: Terebrantia) possess several malformed spermatozoa and a large amount of secretions in their testes. Spermiophagy seems to be typical. It indicates a highly conserved mechanism of the male developmental pathways, despite the observed decay. However, this decay would explain why in some species no stable arrhenotokous line can be re-established.}, }
@article {pmid34292377, year = {2021}, author = {Manoj, RRS and Latrofa, MS and Mendoza-Roldan, JA and Otranto, D}, title = {Molecular detection of Wolbachia endosymbiont in reptiles and their ectoparasites.}, journal = {Parasitology research}, volume = {120}, number = {9}, pages = {3255-3261}, pmid = {34292377}, issn = {1432-1955}, mesh = {Animals ; *Ixodes/microbiology ; *Mites/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Reptiles/*microbiology/parasitology ; *Wolbachia/genetics/isolation &amp; purification ; }, abstract = {Wolbachia, a maternally transmitted Gram-negative endosymbiont of onchocercid nematodes and arthropods, has a role in the biology of their host; thus it has been exploited for the filariasis treatment in humans. To assess the presence and prevalence of this endosymbiont in reptiles and their ectoparasites, blood and tail tissue as well as ticks and mites collected from them were molecularly screened for Wolbachia DNA using two sets of primers targeting partial 16S rRNA and Wolbachia surface protein (wsp) genes. Positive samples were screened for the partial 12S rRNA and cytochrome c oxidase subunit 1 (cox1) genes for filarioids. Of the different species of lizards (Podarcis siculus, Podarcis muralis and Lacerta bilineata) and snakes (Elaphe quatuorlineata and Boa constrictor constrictor) screened from three collection sites, only P. siculus scored positive for Wolbachia 16S rRNA. Among ectoparasites collected from reptiles (Ixodes ricinus ticks and Neotrombicula autumnalis, Ophionyssus sauracum and Ophionyssus natricis mites), I. ricinus (n = 4; 2.8%; 95% CI, 0.9-7) from P. siculus, N. autumnalis (n = 2 each; 2.8%; 95% CI, 0.9-6.5) from P. siculus and P. muralis and O. natricis (n = 1; 14.3%; 95% CI, 0.7-55.4) from Boa constrictor constrictor scored positive for Wolbachia DNA. None of the positive Wolbachia samples scored positive for filarioids. This represents the first report of Wolbachia in reptilian hosts and their ectoparasites, which follows a single identification in the intestinal cells of a filarioid associated with a gecko. This data could contribute to better understand the reptile filarioid-Wolbachia association and to unveil the evolutionary pattern of Wolbachia in its filarial host.}, }
@article {pmid34288947, year = {2021}, author = {Tyagi, K and Tyagi, I and Kumar, V}, title = {Interspecific variation and functional traits of the gut microbiome in spiders from the wild: The largest effort so far.}, journal = {PloS one}, volume = {16}, number = {7}, pages = {e0251790}, pmid = {34288947}, issn = {1932-6203}, mesh = {Animals ; Ecosystem ; *Gastrointestinal Microbiome ; Species Specificity ; Spiders/*microbiology ; Symbiosis ; }, abstract = {Spiders being one of the most diverse group in phylum arthropod are of great importance due to their role as predators, silk producer, and in medicinal applications. Spiders in prey-predator relationships play a crucial role in balancing the food-chain of any ecosystem; therefore it is essential to characterize the gut microbiota of spiders collected from natural environments. In the present work, the largest effort so far has been made to characterize the gut microbiota of 35 spider species belonging to four different families using 16S amplicon targeting sequencing. Further, we compared the gut microbiota composition including endosymbiont abundance in spider species collected from different geographical locations. The results obtained revealed the presence of genera like Acinetobacter (15%), V7clade (9%), Wolbachia (8%), Pseudomonas (5%), Bacillus (6%). Although comparative analysis revealed that the gut bacterial composition in all the spider families has a similar pattern, in terms of community richness and evenness. The bacterial diversity in the spider family, Lycosidae are more diverse than in Salticidae, Tetragnathidae and Araneidae. Furthermore, it was observed that the abundance of endosymbiont genera, i.e. Wolbachia and Rickettsia, leads to shift in the abundance of other bacterial taxa and may cause sexual alterations in spider species. Moreover, predicted functional analysis based on PICRUSt2 reveals that gut microbiota of spider species were involved in functions like metabolism of carbohydrates, cofactors and vitamins, amino acids; biosynthesis of organic compounds, fatty acids, lipids etc. Based on the results obtained, it can be said that different locations do not correlate with community composition of gut microbiota in spider species collected from natural environments.}, }
@article {pmid34287117, year = {2021}, author = {Palomares-Rius, JE and Gutiérrez-Gutiérrez, C and Mota, M and Bert, W and Claeys, M and Yushin, VV and Suzina, NE and Ariskina, EV and Evtushenko, LI and Subbotin, SA and Castillo, P}, title = {'Candidatus Xiphinematincola pachtaicus' gen. nov., sp. nov., an endosymbiotic bacterium associated with nematode species of the genus Xiphinema (Nematoda, Longidoridae).}, journal = {International journal of systematic and evolutionary microbiology}, volume = {71}, number = {7}, pages = {}, pmid = {34287117}, issn = {1466-5034}, mesh = {Animals ; Bacterial Typing Techniques ; Base Composition ; Burkholderiaceae/*classification/isolation &amp; purification ; Citrus/parasitology ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Female ; Genes, Bacterial ; In Situ Hybridization, Fluorescence ; Nematoda/*microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizosphere ; Sequence Analysis, DNA ; Spain ; *Symbiosis ; }, abstract = {An intracellular bacterium, strain IAS[T], was observed to infect several species of the plant-parasitic nematode genus Xiphinema (Xiphinema astaregiense, Xiphinema incertum, Xiphinema madeirense, Xiphinema pachtaicum, Xiphinema parapachydermum and Xiphinema vallense). The bacterium could not be recovered on axenic medium. The 16S rRNA gene sequence of IAS[T] was found to be new, being related to the family Burkholderiaceae, class Betaproteobacteria. Fungal endosymbionts Mycoavidus cysteinexigens B1-EB[T] (92.9 % sequence identity) and 'Candidatus Glomeribacter gigasporarum' BEG34 (89.8 % identity) are the closest taxa and form a separate phylogenetic clade inside Burkholderiaceae. Other genes (atpD, lepA and recA) also separated this species from its closest relatives using a multilocus sequence analysis approach. These genes were obtained using a partial genome of this bacterium. The localization of the bacterium (via light and fluorescence in situ hybridization microscopy) is in the X. pachtaicum females clustered around the developing oocytes, primarily found embedded inside the epithelial wall cells of the ovaries, from where they are dispersed in the intestine. Transmission electron microscopy (TEM) observations supported the presence of bacteria inside the nematode body, where they occupy ovaries and occur inside the intestinal epithelium. Ultrastructural analysis of the bacterium showed cells that appear as mostly irregular, slightly curved rods with rounded ends, 0.8-1.2 µm wide and 2.5-6.0 µm long, possessing a typical Gram-negative cell wall. The peptidoglycan layer is, however, evident only occasionally and not detectable by TEM in most cells. Another irregularly occurring shell surrounding the endosymbiont cells or the cell clusters was also revealed, probably originating from the host cell membrane. Flagella or spore-like cells do not occur and the nucleoid is diffusely distributed throughout the cell. This endosymbiont is transmitted vertically through nematode generations. These results support the proposal of IAS[T] as a new species, although its obligate intracellular and obligate endosymbiont nature prevented isolation of a definitive type strain. Strain IAS[T] is therefore proposed as representing 'Candidatus Xiphinematincola pachtaicus' gen. nov., sp. nov.}, }
@article {pmid34276617, year = {2021}, author = {Huang, J and Dai, Z and Zheng, Z and da Silvia, PA and Kumagai, L and Xiang, Q and Chen, J and Deng, X}, title = {Bacteriomic Analyses of Asian Citrus Psyllid and Citrus Samples Infected With "Candidatus Liberibacter asiaticus" in Southern California and Huanglongbing Management Implications.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {683481}, pmid = {34276617}, issn = {1664-302X}, abstract = {Citrus Huanglongbing (HLB; yellow shoot disease) is associated with an unculturable α-proteobacterium "Candidatus Liberibacter asiaticus" (CLas). HLB was found in southern California in 2012, and the current management strategy is based on suppression of the Asian citrus psyllid (Diaphorina citri) that transmits CLas and removal of confirmed CLas-positive trees. Little is known about Asian citrus psyllid-associated bacteria and citrus-associated bacteria in the HLB system. Such information is important in HLB management, particularly for accurate detection of CLas. Recent advancements in next-generation sequencing technology provide new opportunities to study HLB through genomic DNA sequence analyses (metagenomics). In this study, HLB-related bacteria in Asian citrus psyllid and citrus (represented by leaf midrib tissues) samples from southern California were analyzed. A metagenomic pipeline was developed to serve as a prototype for future bacteriomic research. This pipeline included steps of next-generation sequencing in Illumina platform, de novo assembly of Illumina reads, sequence classification using the Kaiju tool, acquisition of bacterial draft genome sequences, and taxonomic validation and diversity evaluation using average nucleotide identity. The identified bacteria in Asian citrus psyllids and citrus together included Bradyrhizobium, Buchnera, Burkholderia, "Candidatus Profftella armature," "Candidatus Carsonella ruddii," CLas, Mesorhizobium, Paraburkholderia, Pseudomonas, and Wolbachia. The whole genome of a CLas strain recently found in San Bernardino County was sequenced and classified into prophage typing group 1 (PTG-1), one of the five known CLas groups in California. Based on sequence similarity, Bradyrhizobium and Mesorhizobium were identified as possible source that could interfere with CLas detection using the 16S rRNA gene-based PCR commonly used for HLB diagnosis, particularly at low or zero CLas titer situation.}, }
@article {pmid34273392, year = {2021}, author = {Gangwar, M and Jha, R and Goyal, M and Srivastava, M}, title = {Biochemical characterization of Recombinase A from Wolbachia endosymbiont of filarial nematode Brugia malayi (wBmRecA).}, journal = {International journal for parasitology}, volume = {51}, number = {10}, pages = {841-853}, doi = {10.1016/j.ijpara.2021.02.007}, pmid = {34273392}, issn = {1879-0135}, mesh = {Animals ; *Brugia malayi ; *Elephantiasis, Filarial ; Female ; Humans ; Microfilariae ; Rec A Recombinases/antagonists &amp; inhibitors/chemistry/*metabolism ; *Wolbachia ; }, abstract = {Lymphatic filariasis is a debilitating disease that affects over 890 million people in 49 countries. A lack of vaccines, non-availability of adulticidal drugs, the threat of emerging drug resistance against available chemotherapeutics and an incomplete understanding of the immunobiology of the disease have sustained the problem. Characterization of Wolbachia proteins, the bacterial endosymbiont which helps in the growth and development of filarial worms, regulates fecundity in female worms and mediates immunopathogenesis of Lymphatic Filariasis, is an important approach to gain insights into the immunopathogenesis of the disease. In this study, we carried out extensive biochemical characterization of Recombinase A from Wolbachia of the filarial nematode Brugia malayi (wBmRecA) using an Electrophoretic Mobility Shift Assay, an ATP binding and hydrolysis assay, DNA strand exchange reactions, DAPI displacement assay and confocal microscopy, and evaluated anti-filarial activity of RecA inhibitors. Confocal studies showed that wBmRecA was expressed and localised within B. malayi microfilariae (Mf) and uteri and lateral chord of adult females. Recombinant wBmRecA was biochemically active and showed intrinsic binding capacity towards both single-stranded DNA and double-stranded DNA that were enhanced by ATP, suggesting ATP-induced cooperativity. wBmRecA promoted ATP hydrolysis and DNA strand exchange reactions in a concentration-dependent manner, and its binding to DNA was sensitive to temperature, pH and salt concentration. Importantly, the anti-parasitic drug Suramin, and Phthalocyanine tetrasulfonate (PcTs)-based inhibitors Fe-PcTs and 3,4-Cu-PcTs, inhibited wBmRecA activity and affected the motility and viability of Mf. The addition of Doxycycline further enhanced microfilaricidal activity of wBmRecA, suggesting potential synergism. Taken together, the omnipresence of wBmRecA in B. malayi life stages and the potent microfilaricidal activity of RecA inhibitors suggest an important role of wBmRecA in filarial pathogenesis.}, }
@article {pmid34272503, year = {2021}, author = {Russell, A and Borrelli, S and Fontana, R and Laricchiuta, J and Pascar, J and Becking, T and Giraud, I and Cordaux, R and Chandler, CH}, title = {Evolutionary transition to XY sex chromosomes associated with Y-linked duplication of a male hormone gene in a terrestrial isopod.}, journal = {Heredity}, volume = {127}, number = {3}, pages = {266-277}, pmid = {34272503}, issn = {1365-2540}, mesh = {Animals ; Evolution, Molecular ; Female ; Genome ; Hormones ; Humans ; *Isopoda/genetics ; Male ; Sex Chromosomes/genetics ; Sex Determination Processes/genetics ; }, abstract = {Sex chromosomes are highly variable in some taxonomic groups, but the evolutionary mechanisms underlying this diversity are not well understood. In terrestrial isopod crustaceans, evolutionary turnovers in sex chromosomes are frequent, possibly caused by Wolbachia, a vertically-transmitted endosymbiont causing male-to-female sex reversal. Here, we use surgical manipulations and genetic crosses, plus genome sequencing, to examine sex chromosomes in the terrestrial isopod Trachelipus rathkei. Although an earlier cytogenetics study suggested a ZZ/ZW sex chromosome system in this species, we surprisingly find multiple lines of evidence that in our study population, sex is determined by an XX/XY system. Consistent with a recent evolutionary origin for this XX/XY system, the putative male-specific region of the genome is small. The genome shows evidence of Y-linked duplications of the gene encoding the androgenic gland hormone, a major component of male sexual differentiation in isopods. Our analyses also uncover sequences horizontally acquired from past Wolbachia infections, consistent with the hypothesis that Wolbachia may have interfered with the evolution of sex determination in T. rathkei. Overall, these results provide evidence for the co-occurrence of multiple sex chromosome systems within T. rathkei, further highlighting the relevance of terrestrial isopods as models for the study of sex chromosome evolution.}, }
@article {pmid34272286, year = {2021}, author = {Osvatic, JT and Wilkins, LGE and Leibrecht, L and Leray, M and Zauner, S and Polzin, J and Camacho, Y and Gros, O and van Gils, JA and Eisen, JA and Petersen, JM and Yuen, B}, title = {Global biogeography of chemosynthetic symbionts reveals both localized and globally distributed symbiont groups.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {29}, pages = {}, pmid = {34272286}, issn = {1091-6490}, support = {S10 OD010786/OD/NIH HHS/United States ; }, mesh = {Animals ; Autotrophic Processes ; Biodiversity ; Biological Evolution ; Bivalvia/classification/*microbiology/physiology ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification/*physiology ; Host Specificity ; Phylogeny ; Phylogeography ; *Symbiosis ; }, abstract = {In the ocean, most hosts acquire their symbionts from the environment. Due to the immense spatial scales involved, our understanding of the biogeography of hosts and symbionts in marine systems is patchy, although this knowledge is essential for understanding fundamental aspects of symbiosis such as host-symbiont specificity and evolution. Lucinidae is the most species-rich and widely distributed family of marine bivalves hosting autotrophic bacterial endosymbionts. Previous molecular surveys identified location-specific symbiont types that "promiscuously" form associations with multiple divergent cooccurring host species. This flexibility of host-microbe pairings is thought to underpin their global success, as it allows hosts to form associations with locally adapted symbionts. We used metagenomics to investigate the biodiversity, functional variability, and genetic exchange among the endosymbionts of 12 lucinid host species from across the globe. We report a cosmopolitan symbiont species, Candidatus Thiodiazotropha taylori, associated with multiple lucinid host species. Ca. T. taylori has achieved more success at dispersal and establishing symbioses with lucinids than any other symbiont described thus far. This discovery challenges our understanding of symbiont dispersal and location-specific colonization and suggests both symbiont and host flexibility underpin the ecological and evolutionary success of the lucinid symbiosis.}, }
@article {pmid34255082, year = {2021}, author = {Sun, Y and Sun, J and Yang, Y and Lan, Y and Ip, JC and Wong, WC and Kwan, YH and Zhang, Y and Han, Z and Qiu, JW and Qian, PY}, title = {Genomic Signatures Supporting the Symbiosis and Formation of Chitinous Tube in the Deep-Sea Tubeworm Paraescarpia echinospica.}, journal = {Molecular biology and evolution}, volume = {38}, number = {10}, pages = {4116-4134}, pmid = {34255082}, issn = {1537-1719}, mesh = {Animals ; Chitin ; Ecosystem ; Genomics ; *Hydrothermal Vents/microbiology ; Proteomics ; *Symbiosis/genetics ; }, abstract = {Vestimentiferan tubeworms are iconic animals that present as large habitat-forming chitinized tube bushes in deep-sea chemosynthetic ecosystems. They are gutless and depend entirely on their endosymbiotic sulfide-oxidizing chemoautotrophic bacteria for nutrition. Information on the genomes of several siboglinid endosymbionts has improved our understanding of their nutritional supplies. However, the interactions between tubeworms and their endosymbionts remain largely unclear due to a paucity of host genomes. Here, we report the chromosome-level genome of the vestimentiferan tubeworm Paraescarpia echinospica. We found that the genome has been remodeled to facilitate symbiosis through the expansion of gene families related to substrate transfer and innate immunity, suppression of apoptosis, regulation of lysosomal digestion, and protection against oxidative stress. Furthermore, the genome encodes a programmed cell death pathway that potentially controls the endosymbiont population. Our integrated genomic, transcriptomic, and proteomic analyses uncovered matrix proteins required for the formation of the chitinous tube and revealed gene family expansion and co-option as evolutionary mechanisms driving the acquisition of this unique supporting structure for deep-sea tubeworms. Overall, our study provides novel insights into the host's support system that has enabled tubeworms to establish symbiosis, thrive in deep-sea hot vents and cold seeps, and produce the unique chitinous tubes in the deep sea.}, }
@article {pmid34253453, year = {2022}, author = {Massey, JH and Newton, ILG}, title = {Diversity and function of arthropod endosymbiont toxins.}, journal = {Trends in microbiology}, volume = {30}, number = {2}, pages = {185-198}, pmid = {34253453}, issn = {1878-4380}, support = {R01 AI144430/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Arthropods ; Male ; Phylogeny ; *Rickettsia ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Bacterial endosymbionts induce dramatic phenotypes in their arthropod hosts, including cytoplasmic incompatibility, feminization, parthenogenesis, male killing, parasitoid defense, and pathogen blocking. The molecular mechanisms underlying these effects remain largely unknown but recent evidence suggests that protein toxins secreted by the endosymbionts play a role. Here, we describe the diversity and function of endosymbiont proteins with homology to known bacterial toxins. We focus on maternally transmitted endosymbionts belonging to the Wolbachia, Rickettsia, Arsenophonus, Hamiltonella, Spiroplasma, and Cardinium genera because of their ability to induce the above phenotypes. We identify at least 16 distinct toxin families with diverse enzymatic activities, including AMPylases, nucleases, proteases, and glycosyltransferases. Notably, several annotated toxins contain domains with homology to eukaryotic proteins, suggesting that arthropod endosymbionts mimic host biochemistry to manipulate host physiology, similar to bacterial pathogens.}, }
@article {pmid34252087, year = {2021}, author = {Noroy, C and Meyer, DF}, title = {The super repertoire of type IV effectors in the pangenome of Ehrlichia spp. provides insights into host-specificity and pathogenesis.}, journal = {PLoS computational biology}, volume = {17}, number = {7}, pages = {e1008788}, pmid = {34252087}, issn = {1553-7358}, mesh = {Animals ; Bacterial Proteins ; Computational Biology ; *Ehrlichia/genetics/pathogenicity ; Ehrlichiosis/microbiology ; Genome, Bacterial/*genetics ; Host Specificity/*genetics ; Humans ; Type IV Secretion Systems/*genetics ; Virulence/*genetics ; }, abstract = {The identification of bacterial effectors is essential to understand how obligatory intracellular bacteria such as Ehrlichia spp. manipulate the host cell for survival and replication. Infection of mammals-including humans-by the intracellular pathogenic bacteria Ehrlichia spp. depends largely on the injection of virulence proteins that hijack host cell processes. Several hypothetical virulence proteins have been identified in Ehrlichia spp., but one so far has been experimentally shown to translocate into host cells via the type IV secretion system. However, the current challenge is to identify most of the type IV effectors (T4Es) to fully understand their role in Ehrlichia spp. virulence and host adaptation. Here, we predict the T4E repertoires of four sequenced Ehrlichia spp. and four other Anaplasmataceae as comparative models (pathogenic Anaplasma spp. and Wolbachia endosymbiont) using previously developed S4TE 2.0 software. This analysis identified 579 predicted T4Es (228 pT4Es for Ehrlichia spp. only). The effector repertoires of Ehrlichia spp. overlapped, thereby defining a conserved core effectome of 92 predicted effectors shared by all strains. In addition, 69 species-specific T4Es were predicted with non-canonical GC% mostly in gene sparse regions of the genomes and we observed a bias in pT4Es according to host-specificity. We also identified new protein domain combinations, suggesting novel effector functions. This work presenting the predicted effector collection of Ehrlichia spp. can serve as a guide for future functional characterisation of effectors and design of alternative control strategies against these bacteria.}, }
@article {pmid34249780, year = {2021}, author = {Reyes, JIL and Suzuki, Y and Carvajal, T and Muñoz, MNM and Watanabe, K}, title = {Intracellular Interactions Between Arboviruses and Wolbachia in Aedes aegypti.}, journal = {Frontiers in cellular and infection microbiology}, volume = {11}, number = {}, pages = {690087}, pmid = {34249780}, issn = {2235-2988}, mesh = {*Aedes ; Animals ; *Arboviruses ; Humans ; Mosquito Vectors ; *Wolbachia ; *Zika Virus ; *Zika Virus Infection ; }, abstract = {Aedes aegypti is inherently susceptible to arboviruses. The geographical expansion of this vector host species has led to the persistence of Dengue, Zika, and Chikungunya human infections. These viruses take advantage of the mosquito's cell to create an environment conducive for their growth. Arboviral infection triggers transcriptomic and protein dysregulation in Ae. aegypti and in effect, host antiviral mechanisms are compromised. Currently, there are no existing vaccines able to protect human hosts from these infections and thus, vector control strategies such as Wolbachia mass release program is regarded as a viable option. Considerable evidence demonstrates how the presence of Wolbachia interferes with arboviruses by decreasing host cytoskeletal proteins and lipids essential for arboviral infection. Also, Wolbachia strengthens host immunity, cellular regeneration and causes the expression of microRNAs which could potentially be involved in virus inhibition. However, variation in the magnitude of Wolbachia's pathogen blocking effect that is not due to the endosymbiont's density has been recently reported. Furthermore, the cellular mechanisms involved in this phenotype differs depending on Wolbachia strain and host species. This prompts the need to explore the cellular interactions between Ae. aegypti-arboviruses-Wolbachia and how different Wolbachia strains overall affect the mosquito's cell. Understanding what happens at the cellular and molecular level will provide evidence on the sustainability of Wolbachia vector control.}, }
@article {pmid34247634, year = {2021}, author = {Endersby-Harshman, NM and Ali, A and Alhumrani, B and Alkuriji, MA and Al-Fageeh, MB and Al-Malik, A and Alsuabeyl, MS and Elfekih, S and Hoffmann, AA}, title = {Voltage-sensitive sodium channel (Vssc) mutations associated with pyrethroid insecticide resistance in Aedes aegypti (L.) from two districts of Jeddah, Kingdom of Saudi Arabia: baseline information for a Wolbachia release program.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {361}, pmid = {34247634}, issn = {1756-3305}, mesh = {Aedes/*drug effects/*genetics ; Animals ; Biological Assay/methods/statistics &amp; numerical data ; Dengue/prevention &amp; control/transmission ; Female ; Insecticide Resistance/*genetics ; Insecticides/*pharmacology ; Mosquito Control/methods/statistics &amp; numerical data ; *Mutation ; Pyrethrins/*pharmacology ; Saudi Arabia ; Sodium Channels/*genetics ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Dengue suppression often relies on control of the mosquito vector, Aedes aegypti, through applications of insecticides of which the pyrethroid group has played a dominant role. Insecticide resistance is prevalent in Ae. aegypti around the world, and the resulting reduction of insecticide efficacy is likely to exacerbate the impact of dengue. Dengue has been a public health problem in Saudi Arabia, particularly in Jeddah, since its discovery there in the 1990s, and insecticide use for vector control is widespread throughout the city. An alternative approach to insecticide use, based on blocking dengue transmission in mosquitoes by the endosymbiont Wolbachia, is being trialed in Jeddah following the success of this approach in Australia and Malaysia. Knowledge of insecticide resistance status of mosquito populations in Jeddah is a prerequisite for establishing a Wolbachia-based dengue control program as releases of Wolbachia mosquitoes succeed when resistance status of the release population is similar to that of the wild population.<br><br>METHODS: WHO resistance bioassays of mosquitoes with deltamethrin, permethrin and DDT were used in conjunction with TaqMan[&#xae;] SNP Genotyping Assays to characterize mutation profiles of Ae. aegypti.<br><br>RESULTS: Screening of the voltage-sensitive sodium channel (Vssc), the pyrethroid target site, revealed mutations at codons 989, 1016 and 1534 in Ae. aegypti from two districts of Jeddah. The triple mutant homozygote (1016G/1534C/989P) was confirmed from Al Safa and Al Rawabi. Bioassays with pyrethroids (Type I and II) and DDT showed that mosquitoes were resistant to each of these compounds based on WHO definitions. An association between Vssc mutations and resistance was established for the Type II pyrethroid, deltamethrin, with one genotype (989P/1016G/1534F) conferring a survival advantage over two others (989S/1016V/1534C and the triple heterozygote). An indication of synergism of Type I pyrethroid activity with piperonyl butoxide suggests that detoxification by cytochrome P450s accounts for some of the pyrethroid resistance response in Ae. aegypti populations from Jeddah.<br><br>CONCLUSIONS: The results provide a baseline for monitoring and management of resistance as well as knowledge of Vssc genotype frequencies required in Wolbachia release populations to ensure homogeneity with the target field population. Vssc mutation haplotypes observed show some similarity with those from Ae. aegypti in southeast Asia and the Indo-Pacific, but the presence of the triple mutant haplotype in three genotypes indicates that the species in this region may have a unique population history.}, }
@article {pmid34235554, year = {2022}, author = {Buysse, M and Binetruy, F and Leibson, R and Gottlieb, Y and Duron, O}, title = {Ecological Contacts and Host Specificity Promote Replacement of Nutritional Endosymbionts in Ticks.}, journal = {Microbial ecology}, volume = {83}, number = {3}, pages = {776-788}, pmid = {34235554}, issn = {1432-184X}, mesh = {Animals ; *Francisella ; Host Specificity ; Phylogeny ; Symbiosis ; *Ticks ; }, abstract = {Symbiosis with vitamin-provisioning microbes is essential for the nutrition of animals with some specialized feeding habits. While coevolution favors the interdependence between symbiotic partners, their associations are not necessarily stable: Recently acquired symbionts can replace ancestral symbionts. In this study, we demonstrate successful replacement by Francisella-like endosymbionts (-LE), a group of B-vitamin-provisioning endosymbionts, across tick communities driven by horizontal transfers. Using a broad collection of Francisella-LE-infected tick species, we determined the diversity of Francisella-LE haplotypes through a multi-locus strain typing approach and further characterized their phylogenetic relationships and their association with biological traits of their tick hosts. The patterns observed showed that Francisella-LE commonly transfer through similar ecological networks and geographic distributions shared among different tick species and, in certain cases, through preferential shuffling across congeneric tick species. Altogether, these findings reveal the importance of geographic, ecological, and phylogenetic proximity in shaping the replacement pattern in which new nutritional symbioses are initiated.}, }
@article {pmid34229954, year = {2021}, author = {Johnston, KL and Hong, WD and Turner, JD and O'Neill, PM and Ward, SA and Taylor, MJ}, title = {Anti-Wolbachia drugs for filariasis.}, journal = {Trends in parasitology}, volume = {37}, number = {12}, pages = {1068-1081}, doi = {10.1016/j.pt.2021.06.004}, pmid = {34229954}, issn = {1471-5007}, support = {/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Anti-Bacterial Agents/pharmacology/therapeutic use ; Drug Discovery ; *Elephantiasis, Filarial/drug therapy ; Humans ; *Nematode Infections/drug therapy ; *Onchocerciasis/drug therapy ; *Wolbachia ; }, abstract = {The mutualistic association between Wolbachia endosymbionts and their filarial nematode hosts has been exploited as a validated drug target delivering macrofilaricidal outcomes. Limitations of existing antibiotics to scale-up have driven the search for new drugs, which are effective in shorter regimens of 7 days or less. Here, we review the last 14 years of anti-Wolbachia drug discovery by the anti-Wolbachia (A·WOL) consortium, which has screened more than two million compounds, delivering thousands of hit compounds. Refined screening models integrated with robust pharmacokinetic/pharmacodynamic (PK/PD) driven optimisation and selection strategies have delivered the first two drug candidates specifically designed to target Wolbachia. AWZ1066S and ABBV-4083 are currently progressing through clinical trials with the aim of delivering safe and effective macrofilaricides to support the elimination of onchocerciasis and lymphatic filariasis.}, }
@article {pmid34220782, year = {2021}, author = {Obert, T and Rurik, I and Vd'ačný, P}, title = {Diversity and Eco-Evolutionary Associations of Endosymbiotic Astome Ciliates With Their Lumbricid Earthworm Hosts.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {689987}, pmid = {34220782}, issn = {1664-302X}, abstract = {Coevolution of endosymbionts with their hosts plays an important role in the processes of speciation and is among the most fascinating topics in evolutionary biology. Astome ciliates represent an interesting model for coevolutionary studies because they are so tightly associated with their host organisms that they completely lost the cell oral apparatus. In the present study, we used five nuclear markers (18S rRNA gene, ITS1-5.8S-ITS2 region, and 28S rRNA gene) and two mitochondrial genes (16S rRNA gene and cytochrome c oxidase subunit I) to explore the diversity of astomes inhabiting the digestive tract of lumbricid earthworms at temperate latitudes in Central Europe and to cast more light on their host specificity and coevolution events that shaped their diversification. The present coevolutionary and phylogenetic interaction-adjusted similarity analyses suggested that almost every host switch leads to speciation and firm association with the new host. Nevertheless, the suggested high structural host specificity of astomes needs to be tested with increased earthworm sampling, as only 52 out of 735 lumbricid earthworms (7.07%) were inhabited by ciliates. On the other hand, the diversification of astomes associated with megascolecid and glossoscolecid earthworms might have been driven by duplication events without host switching.}, }
@article {pmid34216527, year = {2021}, author = {Yang, K and Yuan, MY and Liu, Y and Guo, CL and Liu, TX and Zhang, YJ and Chu, D}, title = {First evidence for thermal tolerance benefits of the bacterial symbiont Cardinium in an invasive whitefly, Bemisia tabaci.}, journal = {Pest management science}, volume = {77}, number = {11}, pages = {5021-5031}, doi = {10.1002/ps.6543}, pmid = {34216527}, issn = {1526-4998}, mesh = {Animals ; Bacteria ; Female ; Fertility ; *Hemiptera/genetics ; Longevity ; Male ; Symbiosis ; }, abstract = {BACKGROUD: Cardinium symbiont is a maternally inherited bacterial endosymbiont and widely spreads in arthropods including Bemisia tabaci (Hemiptera: Aleyrodidae). However, the potential role of Cardinium played in the biology of their hosts is largely unknown. In two genetic lines (i.e. LS and SG lines) of B. tabaci MED, collected from different locations in China, we tested the effects of Cardinium on the performance of the host whitefly under a constant high temperature (31 °C) using the age-stage two-sex life table method, and explored the genes influenced by Cardinium-infection by RNA-sequencing.<br><br>RESULTS: We found that Cardinium did provide protection of B. tabaci against heat stress under 31&#x2009;&#xb0;C. However, there was a significant connection between Cardinium-infection and whitefly genetic backgrounds. Performance revealed that Cardinium infection can increase the longevity of both female and male adults and oviposition periods in both lines, but it also conferred benefits of fecundity and pre-adult period to LS line. Additionally, the population parameters such as intrinsic rate of increase (r), finite rate of increase (&#x3bb;) and mean generation time (T) demonstrated that Cardinium infection conferred fitness benefits to LS line but not to SG line. Transcriptome analysis indicated that several genes related to homeostasis and metamorphosis such as ubiquitin-related genes were highly expressed in Cardinium-infected B. tabaci.<br><br>CONCLUSION: The research provided the first evidence that Cardinium can increase the thermal tolerance of whitefly, which may be associated with host genetic background.}, }
@article {pmid34215695, year = {2021}, author = {Uwizeye, C and Mars Brisbin, M and Gallet, B and Chevalier, F and LeKieffre, C and Schieber, NL and Falconet, D and Wangpraseurt, D and Schertel, L and Stryhanyuk, H and Musat, N and Mitarai, S and Schwab, Y and Finazzi, G and Decelle, J}, title = {Cytoklepty in the plankton: A host strategy to optimize the bioenergetic machinery of endosymbiotic algae.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {27}, pages = {}, pmid = {34215695}, issn = {1091-6490}, mesh = {Carbon Cycle ; Cell Division ; Cell Nucleus/metabolism ; *Energy Metabolism ; Haptophyta/*metabolism ; Microalgae/cytology ; Mitochondria/metabolism ; Photosynthesis ; Plankton/*cytology ; Plastids/metabolism ; *Symbiosis ; }, abstract = {Endosymbioses have shaped the evolutionary trajectory of life and remain ecologically important. Investigating oceanic photosymbioses can illuminate how algal endosymbionts are energetically exploited by their heterotrophic hosts and inform on putative initial steps of plastid acquisition in eukaryotes. By combining three-dimensional subcellular imaging with photophysiology, carbon flux imaging, and transcriptomics, we show that cell division of endosymbionts (Phaeocystis) is blocked within hosts (Acantharia) and that their cellular architecture and bioenergetic machinery are radically altered. Transcriptional evidence indicates that a nutrient-independent mechanism prevents symbiont cell division and decouples nuclear and plastid division. As endosymbiont plastids proliferate, the volume of the photosynthetic machinery volume increases 100-fold in correlation with the expansion of a reticular mitochondrial network in close proximity to plastids. Photosynthetic efficiency tends to increase with cell size, and photon propagation modeling indicates that the networked mitochondrial architecture enhances light capture. This is accompanied by 150-fold higher carbon uptake and up-regulation of genes involved in photosynthesis and carbon fixation, which, in conjunction with a ca.15-fold size increase of pyrenoids demonstrates enhanced primary production in symbiosis. Mass spectrometry imaging revealed major carbon allocation to plastids and transfer to the host cell. As in most photosymbioses, microalgae are contained within a host phagosome (symbiosome), but here, the phagosome invaginates into enlarged microalgal cells, perhaps to optimize metabolic exchange. This observation adds evidence that the algal metamorphosis is irreversible. Hosts, therefore, trigger and benefit from major bioenergetic remodeling of symbiotic microalgae with potential consequences for the oceanic carbon cycle. Unlike other photosymbioses, this interaction represents a so-called cytoklepty, which is a putative initial step toward plastid acquisition.}, }
@article {pmid34213555, year = {2021}, author = {Thairu, MW and Meduri, VRS and Degnan, PH and Hansen, AK}, title = {Natural Selection Shapes Maintenance of Orthologous sRNAs in Divergent Host-Restricted Bacterial Genomes.}, journal = {Molecular biology and evolution}, volume = {38}, number = {11}, pages = {4778-4791}, pmid = {34213555}, issn = {1537-1719}, mesh = {Animals ; *Buchnera/genetics ; Gene Expression Regulation, Bacterial ; Genome, Bacterial ; *Hemiptera/genetics ; RNA, Bacterial/genetics ; Selection, Genetic ; Symbiosis/genetics ; }, abstract = {Historically it has been difficult to study the evolution of bacterial small RNAs (sRNAs) across distantly related species. For example, identifying homologs of sRNAs is often difficult in genomes that have undergone multiple structural rearrangements. Also, some types of regulatory sRNAs evolve at rapid rates. The high degree of genomic synteny among divergent host-restricted bacterial lineages, including intracellular symbionts, is conducive to sRNA maintenance and homolog identification. In turn, symbiont genomes can provide us with novel insights into sRNA evolution. Here, we examine the sRNA expression profile of the obligate symbiont of psyllids, Carsonella ruddii, which has one of the smallest cellular genomes described. Using RNA-seq, we identified 36 and 32 antisense sRNAs (asRNAs) expressed by Carsonella from the psyllids Bactericera cockerelli (Carsonella-BC) and Diaphorina citri (Carsonella-DC), respectively. The majority of these asRNAs were associated with genes that are involved in essential amino acid biosynthetic pathways. Eleven of the asRNAs were conserved in both Carsonella lineages and the majority were maintained by selection. Notably, five of the corresponding coding sequences are also the targets of conserved asRNAs in a distantly related insect symbiont, Buchnera. We detected differential expression of two asRNAs for genes involved in arginine and leucine biosynthesis occurring between two distinct Carsonella-BC life stages. Using asRNAs identified in Carsonella, Buchnera, and Profftella which are all endosymbionts, and Escherichia coli, we determined that regions upstream of these asRNAs encode unique conserved patterns of AT/GC richness, GC skew, and sequence motifs which may be involved in asRNA regulation.}, }
@article {pmid34212028, year = {2021}, author = {Choi, NJ and Xi, H and Park, J}, title = {A Comparative Analyses of the Complete Mitochondrial Genomes of Fungal Endosymbionts in Sogatella furcifera, White-Backed Planthoppers.}, journal = {International journal of genomics}, volume = {2021}, number = {}, pages = {6652508}, pmid = {34212028}, issn = {2314-4378}, abstract = {Sogatella furcifera Horvath, commonly known as the white-backed planthoppers (WBPH), is an important pest in East Asian rice fields. Fungal endosymbiosis is widespread among planthoppers in the infraorder Fulgoromorpha and suborder Auchenorrhyncha. We successfully obtained complete mitogenome of five WBPH fungal endosymbionts, belonging to the Ophiocordycipitaceae family, from next-generation sequencing (NGS) reads obtained from S. furcifera samples. These five mitogenomes range in length from 55,390 bp to 55,406 bp, which is shorter than the mitogenome of the fungal endosymbiont found in Ricania speculum, black planthoppers. Twenty-eight protein-coding genes (PCGs), 12 tRNAs, and 2 rRNAs were found in the mitogenomes. Two single-nucleotide polymorphisms, two insertions, and three deletions were identified among the five mitogenomes, which were fewer in number than those of four species of Ophiocordycipitaceae, Ophiocordyceps sinensis, Hirsutella thompsonii, Hirsutella rhossiliensis, and Tolypocladium inflatum. Noticeably short lengths (up to 18 bp) of simple sequence repeats were identified in the five WBPH fungal endosymbiont mitogenomes. Phylogenetic analysis based on conserved PCGs across 25 Ophiocordycipitaceae mitogenomes revealed that the five mitogenomes were clustered with that of R. speculum, forming an independent clade. In addition to providing the full mitogenome sequences, obtaining complete mitogenomes of WBPH endosymbionts can provide insights into their phylogenetic positions without needing to isolate the mtDNA from the host. This advantage is of value to future studies involving fungal endosymbiont mitogenomes.}, }
@article {pmid34209060, year = {2021}, author = {Getange, D and Bargul, JL and Kanduma, E and Collins, M and Bodha, B and Denge, D and Chiuya, T and Githaka, N and Younan, M and Fèvre, EM and Bell-Sakyi, L and Villinger, J}, title = {Ticks and Tick-Borne Pathogens Associated with Dromedary Camels (Camelus dromedarius) in Northern Kenya.}, journal = {Microorganisms}, volume = {9}, number = {7}, pages = {}, pmid = {34209060}, issn = {2076-2607}, support = {BB/P024378/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/L019019/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; Newton-Utafiti Fund project BB/S004890/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 107742/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; BB/P024270/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {Ticks and tick-borne pathogens (TBPs) are major constraints to camel health and production, yet epidemiological data on their diversity and impact on dromedary camels remain limited. We surveyed the diversity of ticks and TBPs associated with camels and co-grazing sheep at 12 sites in Marsabit County, northern Kenya. We screened blood and ticks (858 pools) from 296 camels and 77 sheep for bacterial and protozoan TBPs by high-resolution melting analysis and sequencing of PCR products. Hyalomma (75.7%), Amblyomma (17.6%) and Rhipicephalus (6.7%) spp. ticks were morphologically identified and confirmed by molecular analyses. We detected TBP DNA in 80.1% of blood samples from 296 healthy camels. "Candidatus Anaplasma camelii", "Candidatus Ehrlichia regneryi" and Coxiella burnetii were detected in both camels and associated ticks, and Ehrlichia chaffeensis, Rickettsia africae, Rickettsia aeschlimannii and Coxiella endosymbionts were detected in camel ticks. We also detected Ehrlichia ruminantium, which is responsible for heartwater disease in ruminants, in Amblyomma ticks infesting camels and sheep and in sheep blood, indicating its endemicity in Marsabit. Our findings also suggest that camels and/or the ticks infesting them are disease reservoirs of zoonotic Q fever (C. burnetii), ehrlichiosis (E. chaffeensis) and rickettsiosis (R. africae), which pose public health threats to pastoralist communities.}, }
@article {pmid34208681, year = {2021}, author = {Ourry, M and Crosland, A and Lopez, V and Derocles, SAP and Mougel, C and Cortesero, AM and Poinsot, D}, title = {Influential Insider: Wolbachia, an Intracellular Symbiont, Manipulates Bacterial Diversity in Its Insect Host.}, journal = {Microorganisms}, volume = {9}, number = {6}, pages = {}, pmid = {34208681}, issn = {2076-2607}, abstract = {Facultative intracellular symbionts like the α-proteobacteria Wolbachia influence their insect host phenotype but little is known about how much they affect their host microbiota. Here, we quantified the impact of Wolbachia infection on the bacterial community of the cabbage root fly Delia radicum by comparing the microbiota of Wolbachia-free and infected adult flies of both sexes. We used high-throughput DNA sequencing (Illumina MiSeq, 16S rRNA, V5-V7 region) and performed a community and a network analysis. In both sexes, Wolbachia infection significantly decreased the diversity of D. radicum bacterial communities and modified their structure and composition by reducing abundance in some taxa but increasing it in others. Infection by Wolbachia was negatively correlated to 8 bacteria genera (Erwinia was the most impacted), and positively correlated to Providencia and Serratia. We suggest that Wolbachia might antagonize Erwinia for being entomopathogenic (and potentially intracellular), but would favor Providencia and Serratia because they might protect the host against chemical plant defenses. Although they might seem prisoners in a cell, endocellular symbionts can impact the whole microbiota of their host, hence its extended phenotype, which provides them with a way to interact with the outside world.}, }
@article {pmid34205691, year = {2021}, author = {Kobayashi, T and Chatanga, E and Qiu, Y and Simuunza, M and Kajihara, M and Hang'ombe, BM and Eto, Y and Saasa, N and Mori-Kajihara, A and Simulundu, E and Takada, A and Sawa, H and Katakura, K and Nonaka, N and Nakao, R}, title = {Molecular Detection and Genotyping of Coxiella-Like Endosymbionts in Ticks Collected from Animals and Vegetation in Zambia.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {6}, pages = {}, pmid = {34205691}, issn = {2076-0817}, abstract = {Ticks are obligate ectoparasites as they require to feed on their host blood during some or all stages of their life cycle. In addition to the pathogens that ticks harbor and transmit to vertebrate hosts, they also harbor other seemingly nonpathogenic microorganisms including nutritional mutualistic symbionts. Tick nutritional mutualistic symbionts play important roles in the physiology of the host ticks as they are involved in tick reproduction and growth through the supply of B vitamins as well as in pathogen maintenance and propagation. Coxiella-like endosymbionts (CLEs) are the most widespread endosymbionts exclusively reported in ticks. Although CLEs have been investigated in ticks in other parts of the world, there is no report of their investigation in ticks in Zambia. To investigate the occurrence of CLEs, their maintenance, and association with host ticks in Zambia, 175 ticks belonging to six genera, namely Amblyomma, Argas, Haemaphysalis, Hyalomma, Ornithodoros, and Rhipicephalus, were screened for CLEs, followed by characterization of CLEs by multi-locus sequence typing of the five Coxiella housekeeping genes (dnaK, groEL, rpoB, 16S rRNA, and 23S rRNA). The results showed that 45.7% (n = 80) were positive for CLEs. The comparison of the tick 16S rDNA phylogenetic tree with that of the CLEs concatenated sequences showed that there was a strong correlation between the topology of the trees. The results suggest that most of the CLEs have evolved within tick species, supporting the vertical transmission phenomenon. However, the negative results for CLE in some ticks warrants further investigations of other endosymbionts that the ticks in Zambia may also harbor.}, }
@article {pmid34204648, year = {2021}, author = {Frangoulidis, D and Kahlhofer, C and Said, AS and Osman, AY and Chitimia-Dobler, L and Shuaib, YA}, title = {High Prevalence and New Genotype of Coxiella burnetii in Ticks Infesting Camels in Somalia.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {6}, pages = {}, pmid = {34204648}, issn = {2076-0817}, abstract = {Coxiella burnetii is the causative agent of Q fever. It can infect animals, humans, and birds, as well as ticks, and it has a worldwide geographical distribution. To better understand the epidemiology of C. burnetii in Somalia, ticks infesting camels were collected from five different regions, including Bari, Nugaal, Mudug, Sool, and Sanaag, between January and March 2018. Collected ticks were tested for C. burnetii and Coxiella-like endosymbiont DNA by using IS1111, icd, and Com1-target PCR assays. Moreover, sequencing of the 16S-rRNA was conducted. Molecular characterization and typing were done by adaA-gene analysis and plasmid-type identification. Further typing was carried out by 14-marker Multi-Locus Variable-Number Tandem Repeats (MLVA/VNTR) analysis. The investigated ticks (n = 237) were identified as Hyalomma spp. (n = 227, 95.8%), Amblyomma spp. (n = 8, 3.4%), and Ripicephalus spp. (n = 2, 0.8%), and 59.1% (140/237) of them were positive for Coxiella spp. While Sanger sequencing and plasmid-type identification revealed a C. burnetii that harbours the QpRS-plasmid, MLVA/VNTR genotyping showed a new genotype which was initially named D21. In conclusion, this is the first report of C. burnetii in ticks in Somalia. The findings denote the possibility that C. burnetii is endemic in Somalia. Further epidemiological studies investigating samples from humans, animals, and ticks within the context of "One Health" are warranted.}, }
@article {pmid34200026, year = {2021}, author = {Skalický, T and Alves, JMP and Morais, AC and Režnarová, J and Butenko, A and Lukeš, J and Serrano, MG and Buck, GA and Teixeira, MMG and Camargo, EP and Sanders, M and Cotton, JA and Yurchenko, V and Kostygov, AY}, title = {Endosymbiont Capture, a Repeated Process of Endosymbiont Transfer with Replacement in Trypanosomatids Angomonas spp.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {6}, pages = {}, pmid = {34200026}, issn = {2076-0817}, support = {R01 AI050196/AI/NIAID NIH HHS/United States ; }, abstract = {Trypanosomatids of the subfamily Strigomonadinae bear permanent intracellular bacterial symbionts acquired by the common ancestor of these flagellates. However, the cospeciation pattern inherent to such relationships was revealed to be broken upon the description of Angomonas ambiguus, which is sister to A. desouzai, but bears an endosymbiont genetically close to that of A. deanei. Based on phylogenetic inferences, it was proposed that the bacterium from A. deanei had been horizontally transferred to A. ambiguus. Here, we sequenced the bacterial genomes from two A. ambiguus isolates, including a new one from Papua New Guinea, and compared them with the published genome of the A. deanei endosymbiont, revealing differences below the interspecific level. Our phylogenetic analyses confirmed that the endosymbionts of A. ambiguus were obtained from A. deanei and, in addition, demonstrated that this occurred more than once. We propose that coinfection of the same blowfly host and the phylogenetic relatedness of the trypanosomatids facilitate such transitions, whereas the drastic difference in the occurrence of the two trypanosomatid species determines the observed direction of this process. This phenomenon is analogous to organelle (mitochondrion/plastid) capture described in multicellular organisms and, thereafter, we name it endosymbiont capture.}, }
@article {pmid34199688, year = {2021}, author = {Vivero, RJ and Castañeda-Monsalve, VA and Romero, LR and D Hurst, G and Cadavid-Restrepo, G and Moreno-Herrera, CX}, title = {Gut Microbiota Dynamics in Natural Populations of Pintomyia evansi under Experimental Infection with Leishmania infantum.}, journal = {Microorganisms}, volume = {9}, number = {6}, pages = {}, pmid = {34199688}, issn = {2076-2607}, abstract = {Pintomyia evansi is recognized by its vectorial competence in the transmission of parasites that cause fatal visceral leishmaniasis in rural and urban environments of the Caribbean coast of Colombia. The effect on and the variation of the gut microbiota in female P. evansi infected with Leishmania infantum were evaluated under experimental conditions using 16S rRNA Illumina MiSeq sequencing. In the coinfection assay with L. infantum, 96.8% of the midgut microbial population was composed mainly of Proteobacteria (71.0%), followed by Cyanobacteria (20.4%), Actinobacteria (2.7%), and Firmicutes (2.7%). In insect controls (uninfected with L. infantum) that were treated or not with antibiotics, Ralstonia was reported to have high relative abundance (55.1-64.8%), in contrast to guts with a high load of infection from L. infantum (23.4-35.9%).&amp;nbsp;ASVs that moderately increased in guts infected with Leishmania were Bacillus and Aeromonas. Kruskal-Wallis nonparametric variance statistical inference showed statistically significant intergroup differences in the guts of P. evansi infected and uninfected with L. infantum (p < 0.05), suggesting that some individuals of the microbiota could induce or restrict Leishmania infection. This assay also showed a negative effect of the antibiotic treatment and L. infantum infection on the gut microbiota diversity. Endosymbionts, such as Microsporidia infections (<2%), were more often associated with guts without Leishmania infection, whereas Arsenophonus was only found in guts with a high load of Leishmania infection and treated with antibiotics. Finally, this is the first report that showed the potential role of intestinal microbiota in natural populations of P. evansi in susceptibility to L. infantum infection.}, }
@article {pmid34197460, year = {2021}, author = {Kupritz, J and Martin, J and Fischer, K and Curtis, KC and Fauver, JR and Huang, Y and Choi, YJ and Beatty, WL and Mitreva, M and Fischer, PU}, title = {Isolation and characterization of a novel bacteriophage WO from Allonemobius socius crickets in Missouri.}, journal = {PloS one}, volume = {16}, number = {7}, pages = {e0250051}, pmid = {34197460}, issn = {1932-6203}, mesh = {Animals ; Bacteriophages/classification/*genetics/isolation &amp; purification ; Capsid Proteins/genetics ; DNA, Bacterial/chemistry/metabolism ; DNA, Viral/chemistry/metabolism ; Female ; *Genome, Viral ; Gryllidae/*microbiology/virology ; Membrane Proteins/genetics ; Missouri ; Open Reading Frames/genetics ; Phylogeny ; Whole Genome Sequencing ; Wolbachia/genetics/isolation &amp; purification/virology ; }, abstract = {Wolbachia are endosymbionts of numerous arthropod and some nematode species, are important for their development and if present can cause distinct phenotypes of their hosts. Prophage DNA has been frequently detected in Wolbachia, but particles of Wolbachia bacteriophages (phage WO) have been only occasionally isolated. Here, we report the characterization and isolation of a phage WO of the southern ground cricket, Allonemobius socius, and provided the first whole-genome sequence of phage WO from this arthropod family outside of Asia. We screened A. socius abdomen DNA extracts from a cricket population in eastern Missouri by quantitative PCR for Wolbachia surface protein and phage WO capsid protein and found a prevalence of 55% and 50%, respectively, with many crickets positive for both. Immunohistochemistry using antibodies against Wolbachia surface protein showed many Wolbachia clusters in the reproductive system of female crickets. Whole-genome sequencing using Oxford Nanopore MinION and Illumina technology allowed for the assembly of a high-quality, 55 kb phage genome containing 63 open reading frames (ORF) encoding for phage WO structural proteins and host lysis and transcriptional manipulation. Taxonomically important regions of the assembled phage genome were validated by Sanger sequencing of PCR amplicons. Analysis of the nucleotides sequences of the ORFs encoding the large terminase subunit (ORF2) and minor capsid (ORF7) frequently used for phage WO phylogenetics showed highest homology to phage WOAu of Drosophila simulans (94.46% identity) and WOCin2USA1 of the cherry fruit fly, Rhagoletis cingulata (99.33% identity), respectively. Transmission electron microscopy examination of cricket ovaries showed a high density of phage particles within Wolbachia cells. Isolation of phage WO revealed particles characterized by 40-62 nm diameter heads and up to 190 nm long tails. This study provides the first detailed description and genomic characterization of phage WO from North America that is easily accessible in a widely distributed cricket species.}, }
@article {pmid34197116, year = {2021}, author = {Hanke, W and Patt, J and Alenfelder, J and Voss, JH and Zdouc, MM and Kehraus, S and Kim, JB and Grujičić, GV and Namasivayam, V and Reher, R and Müller, CE and Kostenis, E and Crüsemann, M and König, GM}, title = {Feature-Based Molecular Networking for the Targeted Identification of Gq-Inhibiting FR900359 Derivatives.}, journal = {Journal of natural products}, volume = {84}, number = {7}, pages = {1941-1953}, doi = {10.1021/acs.jnatprod.1c00194}, pmid = {34197116}, issn = {1520-6025}, mesh = {Ardisia/chemistry ; Chromobacterium/chemistry ; Depsipeptides/*pharmacology ; HEK293 Cells ; Humans ; Molecular Docking Simulation ; Molecular Structure ; Plant Leaves/chemistry ; Receptors, G-Protein-Coupled/*antagonists &amp; inhibitors ; Signal Transduction/*drug effects ; }, abstract = {Both the soil bacterium Chromobacterium vaccinii and the bacterial endosymbiont Candidatus Burkholderia crenata of the plant Ardisia crenata are producers of FR900359 (FR). This cyclic depsipeptide is a potent and selective Gq protein inhibitor used extensively to investigate the intracellular signaling of G protein coupled receptors (GPCRs). In this study, the metabolomes of both FR producers were investigated and compared using feature-based molecular networking (FBMN). As a result, 30 previously unknown FR derivatives were identified, one-third being unique to C. vaccinii. Guided by MS, a novel FR derivative, FR-6 (compound 1), was isolated, and its structure unambiguously established. In a whole-cell biosensing assay based on detection of dynamic mass redistribution (DMR) as readout for Gq inhibition, FR-6 suppressed Gq signaling with micromolar potency (pIC50 = 5.56). This functional activity was confirmed in radioligand binding assays (pKi = 7.50). This work demonstrates the power of molecular networking, guiding the way to a novel Gq-inhibiting FR derivative and underlining the potency of FR as a Gq inhibitor.}, }
@article {pmid34194462, year = {2021}, author = {Hoecker, N and Hennecke, Y and Schrott, S and Marino, G and Schmidt, SB and Leister, D and Schneider, A}, title = {Gene Replacement in Arabidopsis Reveals Manganese Transport as an Ancient Feature of Human, Plant and Cyanobacterial UPF0016 Proteins.}, journal = {Frontiers in plant science}, volume = {12}, number = {}, pages = {697848}, pmid = {34194462}, issn = {1664-462X}, abstract = {The protein family 0016 (UPF0016) is conserved through evolution, and the few members characterized share a function in Mn[2+] transport. So far, little is known about the history of these proteins in Eukaryotes. In Arabidopsis thaliana five such proteins, comprising four different subcellular localizations including chloroplasts, have been described, whereas non-photosynthetic Eukaryotes have only one. We used a phylogenetic approach to classify the eukaryotic proteins into two subgroups and performed gene-replacement studies to investigate UPF0016 genes of various origins. Replaceability can be scored readily in the Arabidopsis UPF0016 transporter mutant pam71, which exhibits a functional deficiency in photosystem II. The N-terminal region of the Arabidopsis PAM71 was used to direct selected proteins to chloroplast membranes. Transgenic pam71 lines overexpressing the closest plant homolog (CMT1), human TMEM165 or cyanobacterial MNX successfully restored photosystem II efficiency, manganese binding to photosystem II complexes and consequently plant growth rate and biomass production. Thus AtCMT1, HsTMEM165, and SynMNX can operate in the thylakoid membrane and substitute for PAM71 in a non-native environment, indicating that the manganese transport function of UPF0016 proteins is an ancient feature of the family. We propose that the two chloroplast-localized UPF0016 proteins, CMT1 and PAM71, in plants originated from the cyanobacterial endosymbiont that gave rise to the organelle.}, }
@article {pmid34192342, year = {2021}, author = {Salsbery, ME and DeLong, JP}, title = {Thermal adaptation in a holobiont accompanied by phenotypic changes in an endosymbiont.}, journal = {Evolution; international journal of organic evolution}, volume = {75}, number = {8}, pages = {2074-2084}, doi = {10.1111/evo.14301}, pmid = {34192342}, issn = {1558-5646}, mesh = {Acclimatization ; Adaptation, Physiological ; *Ciliophora ; *Paramecium ; Symbiosis ; Temperature ; }, abstract = {How and if organisms can adapt to changing temperatures has drastic consequences for the natural world. Thermal adaptation involves finding a match between temperatures permitting growth and the expected temperature distribution of the environment. However, if and how this match is achieved, and how tightly linked species change together, is poorly understood. Paramecium bursaria is a ciliate that has a tight physiological interaction with endosymbiotic green algae (zoochlorellae). We subjected a wild population of P. bursaria to a cold and warm climate (20 and 32℃) for ∼300 generations. We then measured the thermal performance curve (TPC) for intrinsic rate of growth (rmax) for these evolved lines across temperatures. We also evaluated number and size of the zoochlorellae populations within paramecia cells. TPCs for warm-adapted populations were shallower and broader than TPCs of cold-adapted populations, indicating that the warm populations adapted by moving along a thermal generalist/specialist trade off rather than right-shifting the TPC. Zoochlorellae populations within cold-adapted paramecia had fewer and larger zoochlorellae than hot-adapted paramecia, indicating phenotypic shifts in the endosymbiont accompany thermal adaptation in the host. Our results provide new and novel insight into how species involved in complex interactions will be affected by continuing increasing global temperatures.}, }
@article {pmid34190607, year = {2021}, author = {Leonard, JM and Mitchell, J and Beinart, RA and Delaney, JA and Sanders, JG and Ellis, G and Goddard, EA and Girguis, PR and Scott, KM}, title = {Cooccurring Activities of Two Autotrophic Pathways in Symbionts of the Hydrothermal Vent Tubeworm Riftia pachyptila.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {17}, pages = {e0079421}, pmid = {34190607}, issn = {1098-5336}, mesh = {Animals ; Autotrophic Processes ; Bacterial Proteins/genetics/metabolism ; Citric Acid Cycle ; Gammaproteobacteria/classification/genetics/isolation &amp; purification/*physiology ; Hydrothermal Vents/microbiology/parasitology ; Photosynthesis ; Polychaeta/*microbiology/physiology ; Sulfides/metabolism ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Genome and proteome data predict the presence of both the reductive citric acid cycle (rCAC; also called the reductive tricarboxylic acid cycle) and the Calvin-Benson-Bassham cycle (CBB) in "Candidatus Endoriftia persephonae," the autotrophic sulfur-oxidizing bacterial endosymbiont from the giant hydrothermal vent tubeworm Riftia pachyptila. We tested whether these cycles were differentially induced by sulfide supply, since the synthesis of biosynthetic intermediates by the rCAC is less energetically expensive than that by the CBB. R. pachyptila was incubated under in situ conditions in high-pressure aquaria under low (28 to 40 μmol · h[-1]) or high (180 to 276 μmol · h[-1]) rates of sulfide supply. Symbiont-bearing trophosome samples excised from R. pachyptila maintained under the two conditions were capable of similar rates of CO2 fixation. Activities of the rCAC enzyme ATP-dependent citrate lyase (ACL) and the CBB enzyme 1,3-bisphosphate carboxylase/oxygenase (RubisCO) did not differ between the two conditions, although transcript abundances for ATP-dependent citrate lyase were 4- to 5-fold higher under low-sulfide conditions. δ[13]C values of internal dissolved inorganic carbon (DIC) pools were varied and did not correlate with sulfide supply rate. In samples taken from freshly collected R. pachyptila, δ[13]C values of lipids fell between those collected for organisms using either the rCAC or the CBB exclusively. These observations are consistent with cooccurring activities of the rCAC and the CBB in this symbiosis. IMPORTANCE Previous to this study, the activities of the rCAC and CBB in R. pachyptila had largely been inferred from "omics" studies of R. pachyptila without direct assessment of in situ conditions prior to collection. In this study, R. pachyptila was maintained and monitored in high-pressure aquaria prior to measuring its CO2 fixation parameters. Results suggest that ranges in sulfide concentrations similar to those experienced in situ do not exert a strong influence on the relative activities of the rCAC and the CBB. This observation highlights the importance of further study of this symbiosis and other organisms with multiple CO2-fixing pathways, which recent genomics and biochemical studies suggest are likely to be more prevalent than anticipated.}, }
@article {pmid34190587, year = {2021}, author = {Leitner, M and Bishop, C and Asgari, S}, title = {Transcriptional Response of Wolbachia to Dengue Virus Infection in Cells of the Mosquito Aedes aegypti.}, journal = {mSphere}, volume = {6}, number = {3}, pages = {e0043321}, pmid = {34190587}, issn = {2379-5042}, abstract = {Aedes aegypti transmits one of the most significant mosquito-borne viruses, dengue virus (DENV). The absence of effective vaccines and clinical treatments and the emergence of insecticide resistance in A. aegypti necessitate novel vector control strategies. A new approach uses the endosymbiotic bacterium Wolbachia pipientis to reduce the spread of arboviruses. However, the Wolbachia-mediated antiviral mechanism is not well understood. To shed light on this mechanism, we investigated an unexplored aspect of Wolbachia-virus-mosquito interaction. We used RNA sequencing to examine the transcriptional response of Wolbachia to DENV infection in A. aegypti Aag2 cells transinfected with the wAlbB strain of Wolbachia. Our results suggest that genes encoding an endoribonuclease (RNase HI), a regulator of sigma 70-dependent gene transcription (6S RNA), essential cellular, transmembrane, and stress response functions and primary type I and IV secretion systems were upregulated, while a number of transport and binding proteins of Wolbachia, ribosome structure, and elongation factor-associated genes were downregulated due to DENV infection. Furthermore, bacterial retrotransposon, transposable, and phage-related elements were found among the up- and downregulated genes. We show that Wolbachia elicits a transcriptional response to virus infection and identify differentially expressed Wolbachia genes mostly at the early stages of virus infection. These findings highlight Wolbachia's ability to alter its gene expression in response to DENV infection of the host cell. IMPORTANCE Aedes aegypti is a vector of several pathogenic viruses, including dengue, Zika, chikungunya, and yellow fever viruses, which are of importance to human health. Wolbachia is an endosymbiotic bacterium currently used in transinfected mosquitoes to suppress replication and transmission of dengue viruses. However, the mechanism of Wolbachia-mediated virus inhibition is not fully understood. While several studies have shown mosquitoes' transcriptional responses to dengue virus infection, none have investigated these responses in Wolbachia, which may provide clues to the inhibition mechanism. Our results suggest changes in the expression of a number of functionally important Wolbachia genes upon dengue virus infection, including those involved in stress responses, providing insights into the endosymbiont's reaction to virus infection.}, }
@article {pmid34188937, year = {2021}, author = {Page, CE and Leggat, W and Heron, SF and Fordyce, AJ and Ainsworth, TD}, title = {High flow conditions mediate damaging impacts of sub-lethal thermal stress on corals' endosymbiotic algae.}, journal = {Conservation physiology}, volume = {9}, number = {1}, pages = {coab046}, pmid = {34188937}, issn = {2051-1434}, abstract = {The effects of thermal anomalies on tropical coral endosymbiosis can be mediated by a range of environmental factors, which in turn ultimately influence coral health and survival. One such factor is the water flow conditions over coral reefs and corals. Although the physiological benefits of living under high water flow are well known, there remains a lack of conclusive experimental evidence characterizing how flow mitigates thermal stress responses in corals. Here we use in situ measurements of flow in a variety of reef habitats to constrain the importance of flow speeds on the endosymbiosis of an important reef building species under different thermal regimes. Under high flow speeds (0.15 m s[-1]) and thermal stress, coral endosymbionts retained photosynthetic function and recovery capacity for longer compared to low flow conditions (0.03 m s[-1]). We hypothesize that this may be due to increased rates of mass transfer of key metabolites under higher flow, putatively allowing corals to maintain photosynthetic efficiency for longer. We also identified a positive interactive effect between high flow and a pre-stress, sub-lethal pulse in temperature. While higher flow may delay the onset of photosynthetic stress, it does not appear to confer long-term protection; sustained exposure to thermal stress (eDHW accumulation equivalent to 4.9°C weeks) eventually overwhelmed the coral meta-organism as evidenced by eventual declines in photo-physiological function and endosymbiont densities. Investigating flow patterns at the scale of metres within the context of these physiological impacts can reveal interesting avenues for coral reef management. This study increases our understanding of the effects of water flow on coral reef health in an era of climate change and highlights the potential to learn from existing beneficial bio-physical interactions for the effective preservation of coral reefs into the future.}, }
@article {pmid34187119, year = {2020}, author = {Chigurupati, S and Vijayabalan, S and Selvarajan, KK and Alhowail, A and Kauser, F}, title = {Bacterial endosymbiont inhabiting Leucaena leucocephala leaves and their antioxidant and antidiabetic potential.}, journal = {Journal of complementary &amp; integrative medicine}, volume = {18}, number = {2}, pages = {319-325}, doi = {10.1515/jcim-2020-0203}, pmid = {34187119}, issn = {1553-3840}, mesh = {Animals ; *Antioxidants/pharmacology ; Bacteria ; *Diabetes Mellitus, Experimental/drug therapy ; Hypoglycemic Agents/pharmacology ; Plant Extracts/pharmacology ; Plant Leaves ; RNA, Ribosomal, 16S/genetics ; Rats ; }, abstract = {OBJECTIVES: Research on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves.<br><br>METHODS: Endophytic bacteria were isolated from the leaves of L.&#xa0;leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using &#x3b1;-amylase and &#x3b1;-glucosidase enzyme inhibition assay.<br><br>RESULTS: The isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49&#xa0;&#xb1;&#xa0;0.06 and 11.3&#xa0;&#xb1;&#xa0;0.1&#xa0;&#x3bc;g/mL respectively. LL exhibited &#x3b1;-amylase and &#x3b1;-glucosidase inhibition with an IC50 value of 23.3&#xa0;&#xb1;&#xa0;0.08 and 23.4&#xa0;&#xb1;&#xa0;0.1&#xa0;&#x3bc;g/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200&#xa0;mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8&#xa0;h of treatment when compared to normal and diabetic control rats respectively.<br><br>CONCLUSIONS: Thus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.}, }
@article {pmid34177846, year = {2021}, author = {Tláskal, V and Pylro, VS and Žifčáková, L and Baldrian, P}, title = {Ecological Divergence Within the Enterobacterial Genus Sodalis: From Insect Symbionts to Inhabitants of Decomposing Deadwood.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {668644}, pmid = {34177846}, issn = {1664-302X}, abstract = {The bacterial genus Sodalis is represented by insect endosymbionts as well as free-living species. While the former have been studied frequently, the distribution of the latter is not yet clear. Here, we present a description of a free-living strain, Sodalis ligni sp. nov., originating from decomposing deadwood. The favored occurrence of S. ligni in deadwood is confirmed by both 16S rRNA gene distribution and metagenome data. Pangenome analysis of available Sodalis genomes shows at least three groups within the Sodalis genus: deadwood-associated strains, tsetse fly endosymbionts and endosymbionts of other insects. This differentiation is consistent in terms of the gene frequency level, genome similarity and carbohydrate-active enzyme composition of the genomes. Deadwood-associated strains contain genes for active decomposition of biopolymers of plant and fungal origin and can utilize more diverse carbon sources than their symbiotic relatives. Deadwood-associated strains, but not other Sodalis strains, have the genetic potential to fix N2, and the corresponding genes are expressed in deadwood. Nitrogenase genes are located within the genomes of Sodalis, including S. ligni, at multiple loci represented by more gene variants. We show decomposing wood to be a previously undescribed habitat of the genus Sodalis that appears to show striking ecological divergence.}, }
@article {pmid34159734, year = {2021}, author = {Haselkorn, TS and Jimenez, D and Bashir, U and Sallinger, E and Queller, DC and Strassmann, JE and DiSalvo, S}, title = {Novel Chlamydiae and Amoebophilus endosymbionts are prevalent in wild isolates of the model social amoeba Dictyostelium discoideum.}, journal = {Environmental microbiology reports}, volume = {13}, number = {5}, pages = {708-719}, pmid = {34159734}, issn = {1758-2229}, mesh = {*Amoeba ; Bacteria ; Bacteroidetes ; *Dictyostelium/microbiology ; Symbiosis ; }, abstract = {Amoebae interact with bacteria in multifaceted ways. Amoeba predation can serve as a selective pressure for the development of bacterial virulence traits. Bacteria may also adapt to life inside amoebae, resulting in symbiotic relationships. Indeed, particular lineages of obligate bacterial endosymbionts have been found in different amoebae. Here, we screened an extensive collection of Dictyostelium discoideum wild isolates for the presence of these bacterial symbionts using endosymbiont specific PCR primers. We find that these symbionts are surprisingly common, identified in 42% of screened isolates (N = 730). Members of the Chlamydiae phylum are particularly prevalent, occurring in 27% of the amoeba isolated. They are novel and phylogenetically distinct from other Chlamydiae. We also found Amoebophilus symbionts in 8% of screened isolates (N = 730). Antibiotic-cured amoebae behave similarly to their Chlamydiae or Amoebophilus-infected counterparts, suggesting that these endosymbionts do not significantly impact host fitness, at least in the laboratory. We found several natural isolates were co-infected with multiple endosymbionts, with no obvious fitness effect of co-infection under laboratory conditions. The high prevalence and novelty of amoeba endosymbiont clades in the model organism D. discoideum opens the door to future research on the significance and mechanisms of amoeba-symbiont interactions.}, }
@article {pmid34157872, year = {2021}, author = {Scucchia, F and Malik, A and Zaslansky, P and Putnam, HM and Mass, T}, title = {Combined responses of primary coral polyps and their algal endosymbionts to decreasing seawater pH.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1953}, pages = {20210328}, pmid = {34157872}, issn = {1471-2954}, mesh = {Animals ; *Anthozoa/genetics ; Coral Reefs ; Ecosystem ; Hydrogen-Ion Concentration ; Oceans and Seas ; Seawater ; }, abstract = {With coral reefs declining globally, resilience of these ecosystems hinges on successful coral recruitment. However, knowledge of the acclimatory and/or adaptive potential in response to environmental challenges such as ocean acidification (OA) in earliest life stages is limited. Our combination of physiological measurements, microscopy, computed tomography techniques and gene expression analysis allowed us to thoroughly elucidate the mechanisms underlying the response of early-life stages of corals, together with their algal partners, to the projected decline in oceanic pH. We observed extensive physiological, morphological and transcriptional changes in surviving recruits, and the transition to a less-skeleton/more-tissue phenotype. We found that decreased pH conditions stimulate photosynthesis and endosymbiont growth, and gene expression potentially linked to photosynthates translocation. Our unique holistic study discloses the previously unseen intricate net of interacting mechanisms that regulate the performance of these organisms in response to OA.}, }
@article {pmid34152527, year = {2021}, author = {Dângelo, RAC and Michereff-Filho, M and Inoue-Nagata, AK and da Silva, PS and Chediak, M and Guedes, RNC}, title = {Area-wide insecticide resistance and endosymbiont incidence in the whitefly Bemisia tabaci MEAM1 (B biotype): A Neotropical context.}, journal = {Ecotoxicology (London, England)}, volume = {30}, number = {6}, pages = {1056-1070}, pmid = {34152527}, issn = {1573-3017}, mesh = {Animals ; *Hemiptera ; Humans ; Incidence ; Insecticide Resistance ; *Insecticides/toxicity ; Symbiosis ; }, abstract = {Agriculture insecticides are used against insect pest species, but are able to change community structure in contaminated habitats, and also the genetic pool of exposed individuals. In fact, the latter effect is a relevant tool to in situ biomonitoring of pollutant contamination and impact, besides its practical economic and management concerns. This takes place because the emergence of individuals with resistance to insecticides is particularly frequent among insect pest species and usually enhances insecticide overuse and crop losses. Pest insects of global prominence such as whiteflies are a focus of attention due to problems with insecticide resistance and association with endosymbionts, as the case of the invasive putative species Bemisia tabaci MEAM1. The scenario is particularly complex in the Neotropics, where insecticide use is ubiquitous, but whose spatial scale of occurrence is usually neglected. Here we explored the spatial-dependence of both phenomena in MEAM1 whiteflies recording resistance to two widely used insecticides, lambda-cyhalothrin and spiromesifen, and endosymbiont co-occurrence. Resistance to both insecticides was frequent exhibiting low to moderate frequency of lambda-cyhalothrin resistance and moderate to high frequency of spiromesifen resistance. Among the prevailing whitefly endosymbionts, Wolbachia, Cardinium and Arsenophonus were markedly absent. In contrast, Hamiltonella and Rickettsia prevailed and their incidence was correlated. Furthermore, Rickettsia endosymbionts were particularly associated with lambda-cyhalothrin susceptibility. These traits were spatially dependent with significant variation taking place within an area of about 700 Km[2]. Such findings reinforce the notion of endosymbiont-associated resistance to insecticides, and also of their local incidence allowing spatial mapping and locally-targeted mitigation.}, }
@article {pmid34149652, year = {2021}, author = {Xiao, B and Li, D and Liao, B and Zheng, H and Yang, X and Xie, Y and Xie, Z and Li, C}, title = {Effects of Microplastics Exposure on the Acropora sp. Antioxidant, Immunization and Energy Metabolism Enzyme Activities.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {666100}, pmid = {34149652}, issn = {1664-302X}, abstract = {Microplastic pollution in marine environments has increased rapidly in recent years, with negative influences on the health of marine organisms. Scleractinian coral, one of the most important species in the coral ecosystems, is highly sensitive to microplastic. However, whether microplastic causes physiological disruption of the coral, via oxidative stress, immunity, and energy metabolism, is unclear. In the present study, the physiological responses of the coral Acropora sp. were determined after exposure to polyethylene terephthalate (PET), polyamide 66 (PA66), and polyethylene (PE) microplastic for 96 h. The results showed that there were approximately 4-22 items/nubbin on the surface of the coral skeleton and 2-10 items/nubbin on the inside of the skeleton in the MPs exposure groups. The density of endosymbiont decreased (1.12 × 10[5]-1.24 × 10[5] cell/cm[2]) in MPs exposure groups compared with the control group. Meanwhile, the chlorophyll content was reduced (0.11-0.76 μg/cm[2]) after MPs exposure. Further analysis revealed that the antioxidant enzymes in coral tissues were up-regulated (Total antioxidant capacity T-AOC 2.35 × 10[-3]-1.05 × 10[-2] mmol/mg prot, Total superoxide dismutase T-SOD 3.71-28.67 U/mg prot, glutathione GSH 10.21-10.51 U/mg prot). The alkaline phosphatase (AKP) was inhibited (1.44-4.29 U/mg prot), while nitric oxide (NO) increased (0.69-2.26 μmol/g prot) for cell signal. Moreover, lactate dehydrogenase (LDH) was down-regulated in the whole experiment period (0.19-0.22 U/mg prot), and Glucose-6-phosphate dehydrogenase (G6PDH) for cell the phosphate pentoses pathway was also reduced (0.01-0.04 U/mg port). Results showed that the endosymbiont was released and chlorophyll was decreased. In addition, a disruption could occur under MPs exposure, which was related to anti-oxidant, immune, and energy metabolism.}, }
@article {pmid34146106, year = {2021}, author = {Ying, L and Baiming, L and Hongran, L and Tianbo, D and Yunli, T and Dong, C}, title = {Effect of Cardinium Infection on the Probing Behavior of Bemisia tabaci (Hemiptera: Aleyrodidae) MED.}, journal = {Journal of insect science (Online)}, volume = {21}, number = {3}, pages = {}, pmid = {34146106}, issn = {1536-2442}, mesh = {Animals ; Bacteria ; Bacterial Infections ; *Behavior ; *Hemiptera/microbiology/physiology ; Host Microbial Interactions/*physiology ; *Symbiosis ; }, abstract = {Facultative endosymbionts can affect the growth, physiology, and behavior of their arthropod hosts. There are several endosymbionts in the invasive whitefly Bemisia tabaci Mediterranean (MED, Q biotype) that influence host fitness by altering stylet probing behavior. We investigated the probing behavior of B. tabaci MED infected with the facultative endosymbiont Candidatus Cardinium hertigii (Cardinium (Sphingobacteriales: Flexibacteraceae)). We generated genetically similar Cardinium-infected (C*+) and uninfected (C-) clonal sublines and analyzed the probing behavior of newly emerged adult on cotton (Malvales: Malvaceae), Gossypium hirsutum L., using electropenetrography (EPG). The C- subline demonstrated a longer duration of E2 (2.81-fold) and more events of E2 (2.22-fold) than the C*+ subline, indicating a greater level of sustained ingestion of plant phloem. These findings provide insight into the fitness costs (fitness of a particular genotype is lower than the average fitness of the population) of the Cardinium-infected B. tabaci.}, }
@article {pmid34143770, year = {2021}, author = {Duarte, EH and Carvalho, A and López-Madrigal, S and Costa, J and Teixeira, L}, title = {Forward genetics in Wolbachia: Regulation of Wolbachia proliferation by the amplification and deletion of an addictive genomic island.}, journal = {PLoS genetics}, volume = {17}, number = {6}, pages = {e1009612}, pmid = {34143770}, issn = {1553-7404}, mesh = {Animals ; Bacterial Load ; Dicistroviridae/growth &amp; development/pathogenicity ; Drosophila melanogaster/immunology/*microbiology/virology ; Female ; Gene Editing/methods ; *Genome, Bacterial ; Genomic Islands ; Longevity/*immunology ; Male ; Phenotype ; Symbiosis/*genetics ; Wolbachia/*genetics/growth &amp; development/metabolism ; }, abstract = {Wolbachia is one of the most prevalent bacterial endosymbionts, infecting approximately 40% of terrestrial arthropod species. Wolbachia is often a reproductive parasite but can also provide fitness benefits to its host, as, for example, protection against viral pathogens. This protective effect is currently being applied to fight arboviruses transmission by releasing Wolbachia-transinfected mosquitoes. Titre regulation is a crucial aspect of Wolbachia biology. Higher titres can lead to stronger phenotypes and fidelity of transmission but can have a higher cost to the host. Since Wolbachia is maternally transmitted, its fitness depends on host fitness, and, therefore, its cost to the host may be under selection. Understanding how Wolbachia titres are regulated and other aspects of Wolbachia biology has been hampered by the lack of genetic tools. Here we developed a forward genetic screen to identify new Wolbachia over-proliferative mutant variants. We characterized in detail two new mutants, wMelPop2 and wMelOctoless, and show that the amplification or loss of the Octomom genomic region lead to over-proliferation. These results confirm previous data and expand on the complex role of this genomic region in the control of Wolbachia proliferation. Both new mutants shorten the host lifespan and increase antiviral protection. Moreover, we show that Wolbachia proliferation rate in Drosophila melanogaster depends on the interaction between Octomom copy number, the host developmental stage, and temperature. Our analysis also suggests that the life shortening and antiviral protection phenotypes of Wolbachia are dependent on different, but related, properties of the endosymbiont; the rate of proliferation and the titres near the time of infection, respectively. We also demonstrate the feasibility of a novel and unbiased experimental approach to study Wolbachia biology, which could be further adapted to characterize other genetically intractable bacterial endosymbionts.}, }
@article {pmid34141272, year = {2021}, author = {Zhao, C and Miao, S and Yin, Y and Zhu, Y and Nabity, P and Bansal, R and Liu, C}, title = {Tripartite parasitic and symbiotic interactions as a possible mechanism of horizontal gene transfer.}, journal = {Ecology and evolution}, volume = {11}, number = {11}, pages = {7018-7028}, pmid = {34141272}, issn = {2045-7758}, abstract = {Herbivory is a highly sophisticated feeding behavior that requires abilities of plant defense suppression, phytochemical detoxification, and plant macromolecule digestion. For plant-sucking insects, salivary glands (SGs) play important roles in herbivory by secreting and injecting proteins into plant tissues to facilitate feeding. Little is known on how insects evolved secretory SG proteins for such specialized functions. Here, we investigated the composition and evolution of secretory SG proteins in the brown marmorated stink bug (Halyomorpha halys) and identified a group of secretory SG phospholipase C (PLC) genes with highest sequence similarity to the bacterial homologs. Further analyses demonstrated that they were most closely related to PLCs of Xenorhabdus, a genus of Gammaproteobacteria living in symbiosis with insect-parasitizing nematodes. These suggested that H. halys might acquire these PLCs from Xenorhabdus through the mechanism of horizontal gene transfer (HGT), likely mediated by a nematode during its parasitizing an insect host. We also showed that the original HGT event was followed by gene duplication and expansion, leading to functional diversification of the bacterial-origin PLC genes in H. halys. Thus, this study suggested that an herbivore might enhance adaptation through gaining genes from an endosymbiont of its parasite in the tripartite parasitic and symbiotic interactions.}, }
@article {pmid34140946, year = {2021}, author = {Williams, TJ and Allen, MA and Ivanova, N and Huntemann, M and Haque, S and Hancock, AM and Brazendale, S and Cavicchioli, R}, title = {Genome Analysis of a Verrucomicrobial Endosymbiont With a Tiny Genome Discovered in an Antarctic Lake.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {674758}, pmid = {34140946}, issn = {1664-302X}, abstract = {Organic Lake in Antarctica is a marine-derived, cold (-13∘C), stratified (oxic-anoxic), hypersaline (>200 gl[-1]) system with unusual chemistry (very high levels of dimethylsulfide) that supports the growth of phylogenetically and metabolically diverse microorganisms. Symbionts are not well characterized in Antarctica. However, unicellular eukaryotes are often present in Antarctic lakes and theoretically could harbor endosymbionts. Here, we describe Candidatus Organicella extenuata, a member of the Verrucomicrobia with a highly reduced genome, recovered as a metagenome-assembled genome with genetic code 4 (UGA-to-Trp recoding) from Organic Lake. It is closely related to Candidatus Pinguicocccus supinus (163,218 bp, 205 genes), a newly described cytoplasmic endosymbiont of the freshwater ciliate Euplotes vanleeuwenhoeki (Serra et al., 2020). At 158,228 bp (encoding 194 genes), the genome of Ca. Organicella extenuata is among the smallest known bacterial genomes and similar to the genome of Ca. Pinguicoccus supinus (163,218 bp, 205 genes). Ca. Organicella extenuata retains a capacity for replication, transcription, translation, and protein-folding while lacking any capacity for the biosynthesis of amino acids or vitamins. Notably, the endosymbiont retains a capacity for fatty acid synthesis (type II) and iron-sulfur (Fe-S) cluster assembly. Metagenomic analysis of 150 new metagenomes from Organic Lake and more than 70 other Antarctic aquatic locations revealed a strong correlation in abundance between Ca. Organicella extenuata and a novel ciliate of the genus Euplotes. Like Ca. Pinguicoccus supinus, we infer that Ca. Organicella extenuata is an endosymbiont of Euplotes and hypothesize that both Ca. Organicella extenuata and Ca. Pinguicocccus supinus provide fatty acids and Fe-S clusters to their Euplotes host as the foundation of a mutualistic symbiosis. The discovery of Ca. Organicella extenuata as possessing genetic code 4 illustrates that in addition to identifying endosymbionts by sequencing known symbiotic communities and searching metagenome data using reference endosymbiont genomes, the potential exists to identify novel endosymbionts by searching for unusual coding parameters.}, }
@article {pmid34134631, year = {2021}, author = {Kaech, H and Dennis, AB and Vorburger, C}, title = {Triple RNA-Seq characterizes aphid gene expression in response to infection with unequally virulent strains of the endosymbiont Hamiltonella defensa.}, journal = {BMC genomics}, volume = {22}, number = {1}, pages = {449}, pmid = {34134631}, issn = {1471-2164}, mesh = {Animals ; *Aphids/genetics ; Enterobacteriaceae/genetics ; Gene Expression ; RNA-Seq ; Symbiosis/genetics ; *Wasps ; }, abstract = {BACKGROUND: Secondary endosymbionts of aphids provide benefits to their hosts, but also impose costs such as reduced lifespan and reproductive output. The aphid Aphis fabae is host to different strains of the secondary endosymbiont Hamiltonella defensa, which encode different putative toxins. These strains have very different phenotypes: They reach different densities in the host, and the costs and benefits (protection against parasitoid wasps) they confer to the host vary strongly.<br><br>RESULTS: We used RNA-Seq to generate hypotheses on why four of these strains inflict such different costs to A. fabae. We found different H. defensa strains to cause strain-specific changes in aphid gene expression, but little effect of H. defensa on gene expression of the primary endosymbiont, Buchnera aphidicola. The highly costly and over-replicating H. defensa strain H85 was associated with strongly reduced aphid expression of hemocytin, a marker of hemocytes in Drosophila. The closely related strain H15 was associated with downregulation of ubiquitin-related modifier 1, which is related to nutrient-sensing and oxidative stress in other organisms. Strain H402 was associated with strong differential regulation of a set of hypothetical proteins, the majority of which were only differentially regulated in presence of H402.<br><br>CONCLUSIONS: Overall, our results suggest that costs of different strains of H. defensa are likely caused by different mechanisms, and that these costs are imposed by interacting with the host rather than the host's obligatory endosymbiont B. aphidicola.}, }
@article {pmid34125088, year = {2021}, author = {Dukes, HE and Dyer, JE and Ottesen, EA}, title = {Establishment and Maintenance of Gnotobiotic American Cockroaches (Periplaneta americana).}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {171}, pages = {}, pmid = {34125088}, issn = {1940-087X}, support = {R35 GM133789/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Gastrointestinal Microbiome ; Germ-Free Life ; *Periplaneta/microbiology ; Rats ; }, abstract = {Gnotobiotic animals are a powerful tool for the study of controls on microbiome structure and function. Presented here is a protocol for the establishment and maintenance of gnotobiotic American cockroaches (Periplaneta americana). This approach includes built-in sterility checks for ongoing quality control. Gnotobiotic insects are defined here as cockroaches that still contain their vertically transmitted endosymbiont (Blattabacterium) but lack other microbes that normally reside on their surface and in their digestive tract. For this protocol, egg cases (oothecae) are removed from a (nonsterile) stock colony and surface sterilized. Once collected and sterilized, the oothecae are incubated at 30 °C for approximately 4-6 weeks on brain-heart infusion (BHI) agar until they hatch or are removed due to contamination. Hatched nymphs are transferred to an Erlenmeyer flask containing a BHI floor, sterile water, and sterile rat food. To ensure that the nymphs are not housing microbes that are unable to grow on BHI in the given conditions, an additional quality control measure uses restriction fragment-length polymorphism (RFLP) to test for nonendosymbiotic microbes. Gnotobiotic nymphs generated using this approach can be inoculated with simple or complex microbial communities and used as a tool in gut microbiome studies.}, }
@article {pmid34124939, year = {2021}, author = {Baaziz, H and Compton, KK and Hildreth, SB and Helm, RF and Scharf, BE}, title = {McpT, a Broad-Range Carboxylate Chemoreceptor in Sinorhizobium meliloti.}, journal = {Journal of bacteriology}, volume = {203}, number = {17}, pages = {e0021621}, pmid = {34124939}, issn = {1098-5530}, mesh = {Bacterial Proteins/genetics/*metabolism ; Carboxylic Acids/chemistry/metabolism ; Chemotactic Factors/genetics/*metabolism ; Chemotaxis ; Gene Deletion ; Glyoxylates/metabolism ; Ligands ; Sinorhizobium meliloti/genetics/*metabolism ; }, abstract = {Chemoreceptors enable the legume symbiont Sinorhizobium meliloti to detect and respond to specific chemicals released from their host plant alfalfa, which allows the establishment of a nitrogen-fixing symbiosis. The periplasmic region (PR) of transmembrane chemoreceptors act as the sensory input module for chemotaxis systems via binding of specific ligands, either directly or indirectly. S. meliloti has six transmembrane and two cytosolic chemoreceptors. However, the function of only three of the transmembrane receptors have been characterized so far, with McpU, McpV, and McpX serving as general amino acid, short-chain carboxylate, and quaternary ammonium compound sensors, respectively. In the present study, we analyzed the S. meliloti chemoreceptor McpT. High-throughput differential scanning fluorimetry assays, using Biolog phenotype microarray plates, identified 15 potential ligands for McpT[PR], with the majority classified as mono-, di-, and tricarboxylates. S. meliloti exhibited positive chemotaxis toward seven selected carboxylates, namely, α-ketobutyrate, citrate, glyoxylate, malate, malonate, oxalate, and succinate. These carboxylates were detected in seed exudates of the alfalfa host. Deletion of mcpT resulted in a significant decrease of chemotaxis to all carboxylates except for citrate. Isothermal titration calorimetry revealed that McpT[PR] bound preferentially to the monocarboxylate glyoxylate and with lower affinity to the dicarboxylates malate, malonate, and oxalate. However, no direct binding was detected for the remaining three carboxylates that elicited an McpT-dependent chemotaxis response. Taken together, these results demonstrate that McpT is a broad-range carboxylate chemoreceptor that mediates chemotactic response via direct ligand binding and an indirect mechanism that needs to be identified. IMPORTANCE Nitrate pollution is one of the most widespread and challenging environmental problems that is mainly caused by the agricultural overapplication of nitrogen fertilizers. Biological nitrogen fixation by the endosymbiont Sinorhizobium meliloti enhances the growth of its host Medicago sativa (alfalfa), which also efficiently supplies the soil with nitrogen. Establishment of the S. meliloti-alfalfa symbiosis relies on the early exchange and recognition of chemical signals. The present study contributes to the disclosure of this complex molecular dialogue by investigating the underlying mechanisms of carboxylate sensing in S. meliloti. Understanding individual steps that govern the S. meliloti-alfalfa molecular cross talk helps in the development of efficient, commercial bacterial inoculants that promote the growth of alfalfa, which is the most cultivated forage legume in the world, and improves soil fertility.}, }
@article {pmid34122387, year = {2021}, author = {Fujiwara, Y and Kawamura, I and Reimer, JD and Parkinson, JE}, title = {Zoantharian Endosymbiont Community Dynamics During a Stress Event.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {674026}, pmid = {34122387}, issn = {1664-302X}, abstract = {Coral reefs are complex ecosystems composed of many interacting species. One ecologically important group consists of zoantharians, which are closely related to reef-building corals. Like corals, zoantharians form mutualistic symbioses with dinoflagellate micro-algae (family Symbiodiniaceae), but their associations remain underexplored. To examine the degree to which zoantharians exhibit altered symbiont dynamics under changing environmental conditions, we reciprocally transplanted colonies of Zoanthus sansibaricus between intertidal (2 m) and subtidal (26 m) depths within a reef in Okinawa, Japan. At this location, Z. sansibaricus can associate with three Symbiodiniaceae species from two genera distributed along a light and depth gradient. We developed species-specific molecular assays and sampled colonies pre- and post-transplantation to analyze symbiont community diversity. Despite large environmental differences across depths, we detected few symbiont compositional changes resulting from transplantation stress. Colonies sourced from the intertidal zone associated with mixtures of a "shallow" Symbiodinium sp. and a "shallow" Cladocopium sp. independent of whether they were transplanted to shallow or deep waters. Colonies sourced from the subtidal zone were dominated by a "deep" Cladocopium sp. regardless of transplant depth. Subtidal colonies brought to shallow depths did not transition to the presumably high-light adapted shallow symbionts present in the new environment, but rather bleached and died. These patterns mirror observations of highly stable coral-algal associations subjected to depth transplantation. Our results indicate that Zoanthus-Symbiodiniaceae symbioses remain stable despite stress, suggesting these important reef community members have relatively low capacity to shuffle to more stress-tolerant micro-algae in response to ongoing climate change.}, }
@article {pmid34122367, year = {2021}, author = {Demirbas-Uzel, G and Augustinos, AA and Doudoumis, V and Parker, AG and Tsiamis, G and Bourtzis, K and Abd-Alla, AMM}, title = {Interactions Between Tsetse Endosymbionts and Glossina pallidipes Salivary Gland Hypertrophy Virus in Glossina Hosts.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {653880}, pmid = {34122367}, issn = {1664-302X}, abstract = {Tsetse flies are the sole cyclic vector for trypanosomosis, the causative agent for human African trypanosomosis or sleeping sickness and African animal trypanosomosis or nagana. Tsetse population control is the most efficient strategy for animal trypanosomosis control. Among all tsetse control methods, the Sterile Insect Technique (SIT) is one of the most powerful control tactics to suppress or eradicate tsetse flies. However, one of the challenges for the implementation of SIT is the mass production of target species. Tsetse flies have a highly regulated and defined microbial fauna composed of three bacterial symbionts (Wigglesworthia, Sodalis and Wolbachia) and a pathogenic Glossina pallidipes Salivary Gland Hypertrophy Virus (GpSGHV) which causes reproduction alterations such as testicular degeneration and ovarian abnormalities with reduced fertility and fecundity. Interactions between symbionts and GpSGHV might affect the performance of the insect host. In the present study, we assessed the possible impact of GpSGHV on the prevalence of tsetse endosymbionts under laboratory conditions to decipher the bidirectional interactions on six Glossina laboratory species. The results indicate that tsetse symbiont densities increased over time in tsetse colonies with no clear impact of the GpSGHV infection on symbionts density. However, a positive correlation between the GpSGHV and Sodalis density was observed in Glossina fuscipes species. In contrast, a negative correlation between the GpSGHV density and symbionts density was observed in the other taxa. It is worth noting that the lowest Wigglesworthia density was observed in G. pallidipes, the species which suffers most from GpSGHV infection. In conclusion, the interactions between GpSGHV infection and tsetse symbiont infections seems complicated and affected by the host and the infection density of the GpSGHV and tsetse symbionts.}, }
@article {pmid34121858, year = {2021}, author = {Ibrahim, S and Gupta, RK and War, AR and Hussain, B and Kumar, A and Sofi, T and Noureldeen, A and Darwish, H}, title = {Degradation of chlorpyriphos and polyethylene by endosymbiotic bacteria from citrus mealybug.}, journal = {Saudi journal of biological sciences}, volume = {28}, number = {6}, pages = {3214-3224}, pmid = {34121858}, issn = {1319-562X}, abstract = {Chlorpyriphos is one of the major organophosphorus pesticides used widely to control a range of insect pests across several crops. This insecticide is hazardous to the environment and toxic to mammals, thus, it is essential to remove the same from the environment. Similarly, use of polythene is also increasing day by day. Therefore, it is highly important to identify ways to degrade chlorpyriphos and other pesticides from the environment. We studied the degradation of chlorpyriphos and polyethylene by Citrus mealybug (Planococcus citri) bacterial endosymbionts such as Bacillus licheniformis, Pseudomonas cereus, Pseudomonas putida and Bacillus subtilis. This investigation revealed that bacterial endosymbionts use the polythene as a source of carbon and solubilize them by their enzymatic machinery. The degradation of polyethylene by endosymbionts showed a significant reduction in weight of polyethylene sheet after 15, 30 and 45 days of treatment. The SEM images showed localized degradation of the polyethylene around the bacterial cells in the biofilm. Further, the tensile strength (percentage elongation) was significantly reduced after 45 days of incubation. The weight of paraffin wax showed significant reduction in B. cereus. A significant reduction in total amount of chlorpyriphos in soil was observed at an interval of 7, 14 and 21 days after treatment by the bacterial isolates. Among the bacteria, B. cereus and P. putida were found to be most effective. The results from this study show that endosymbionts can be significantly implicated in degrading chlorpyriphos and polyethylene from the environment.}, }
@article {pmid34117067, year = {2021}, author = {Muñoz-Gómez, SA and Kreutz, M and Hess, S}, title = {A microbial eukaryote with a unique combination of purple bacteria and green algae as endosymbionts.}, journal = {Science advances}, volume = {7}, number = {24}, pages = {}, pmid = {34117067}, issn = {2375-2548}, abstract = {Oxygenic photosynthesizers (cyanobacteria and eukaryotic algae) have repeatedly become endosymbionts throughout evolution. In contrast, anoxygenic photosynthesizers (e.g., purple bacteria) are exceedingly rare as intracellular symbionts. Here, we report on the morphology, ultrastructure, lifestyle, and metagenome of the only "purple-green" eukaryote known. The ciliate Pseudoblepharisma tenue harbors green algae and hundreds of genetically reduced purple bacteria. The latter represent a new candidate species of the Chromatiaceae that lost known genes for sulfur dissimilation. The tripartite consortium is physiologically complex because of the versatile energy metabolism of each partner but appears to be ecologically specialized as it prefers hypoxic sediments. The emergent niche of this complex symbiosis is predicted to be a partial overlap of each partners' niches and may be largely defined by anoxygenic photosynthesis and possibly phagotrophy. This purple-green ciliate thus represents an extraordinary example of how symbiosis merges disparate physiologies and allows emergent consortia to create novel ecological niches.}, }
@article {pmid34108021, year = {2021}, author = {Novelo, M and Audsley, MD and McGraw, EA}, title = {The effects of DENV serotype competition and co-infection on viral kinetics in Wolbachia-infected and uninfected Aedes aegypti mosquitoes.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {314}, pmid = {34108021}, issn = {1756-3305}, mesh = {Aedes/*microbiology/physiology/*virology ; Animals ; Dengue Virus/chemistry/classification/genetics/*physiology ; Female ; Kinetics ; Mosquito Vectors/*microbiology/physiology/*virology ; Viral Load ; Virus Replication ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: The Aedes aegypti mosquito is responsible for the transmission of several medically important arthropod-borne viruses, including multiple serotypes of dengue virus (DENV-1, -2, -3, and -4). Competition within the mosquito between DENV serotypes can affect viral infection dynamics, modulating the transmission potential of the pathogen. Vector control remains the main method for limiting dengue fever. The insect endosymbiont Wolbachia pipientis is currently being trialed in field releases globally as a means of biological control because it reduces virus replication inside the mosquito. It is not clear how co-infection between DENV serotypes in the same mosquito might alter the pathogen-blocking phenotype elicited by Wolbachia in Ae. aegypti.<br><br>METHODS: Five- to 7-day-old female Ae. aegypti from two lines, namely, with (wMel) and without Wolbachia infection (WT), were fed virus-laden blood through an artificial membrane with either a mix of DENV-2 and DENV-3 or the same DENV serotypes singly. Mosquitoes were subsequently incubated inside environmental chambers and collected on the following days post-infection: 3, 4, 5, 7, 8, 9, 11, 12, and 13. Midgut, carcass, and salivary glands were collected from each mosquito at each timepoint and individually analyzed to determine the percentage of DENV infection and viral RNA load via RT-qPCR.<br><br>RESULTS: We saw that for WT mosquitoes DENV-3 grew to higher viral RNA loads across multiple tissues when co-infected with DENV-2 than when it was in a mono-infection. Additionally, we saw a strong pathogen-blocking phenotype in wMel mosquitoes independent of co-infection status.<br><br>CONCLUSION: In this study, we demonstrated that the wMel mosquito line is capable of blocking DENV serotype co-infection in a systemic way across the mosquito body. Moreover, we showed that for WT mosquitoes, serotype co-infection can affect infection frequency in a tissue- and time-specific manner and that both viruses have the potential of being transmitted simultaneously. Our findings suggest that the long-term efficacy of Wolbachia pathogen blocking is not compromised by arthropod-borne virus co-infection.}, }
@article {pmid34107000, year = {2021}, author = {Yang, L and Weiss, BL and Williams, AE and Aksoy, E and de Silva Orfano, A and Son, JH and Wu, Y and Vigneron, A and Karakus, M and Aksoy, S}, title = {Paratransgenic manipulation of a tsetse microRNA alters the physiological homeostasis of the fly's midgut environment.}, journal = {PLoS pathogens}, volume = {17}, number = {6}, pages = {e1009475}, pmid = {34107000}, issn = {1553-7374}, support = {R01 AI139525/AI/NIAID NIH HHS/United States ; UL1 TR001863/TR/NCATS NIH HHS/United States ; }, mesh = {Animals ; Animals, Genetically Modified ; Gastrointestinal Microbiome/physiology ; Genes, Insect ; Homeostasis/*physiology ; Insect Vectors/genetics/parasitology ; Intestines/*physiology ; MicroRNAs/*genetics ; Trypanosoma ; Trypanosomiasis, African/*parasitology ; Tsetse Flies/*genetics/*parasitology ; }, abstract = {Tsetse flies are vectors of parasitic African trypanosomes, the etiological agents of human and animal African trypanosomoses. Current disease control methods include fly-repelling pesticides, fly trapping, and chemotherapeutic treatment of infected people and animals. Inhibiting tsetse's ability to transmit trypanosomes by strengthening the fly's natural barriers can serve as an alternative approach to reduce disease. The peritrophic matrix (PM) is a chitinous and proteinaceous barrier that lines the insect midgut and serves as a protective barrier that inhibits infection with pathogens. African trypanosomes must cross tsetse's PM in order to establish an infection in the fly, and PM structural integrity negatively correlates with trypanosome infection outcomes. Bloodstream form trypanosomes shed variant surface glycoproteins (VSG) into tsetse's gut lumen early during the infection establishment, and free VSG molecules are internalized by the fly's PM-producing cardia. This process results in a reduction in the expression of a tsetse microRNA (miR275) and a sequential molecular cascade that compromises PM integrity. miRNAs are small non-coding RNAs that are critical in regulating many physiological processes. In the present study, we investigated the role(s) of tsetse miR275 by developing a paratransgenic expression system that employs tsetse's facultative bacterial endosymbiont, Sodalis glossinidius, to express tandem antagomir-275 repeats (or miR275 sponges). This system induces a constitutive, 40% reduction in miR275 transcript abundance in the fly's midgut and results in obstructed blood digestion (gut weights increased by 52%), a significant increase (p-value < 0.0001) in fly survival following infection with an entomopathogenic bacteria, and a 78% increase in trypanosome infection prevalence. RNA sequencing of cardia and midgut tissues from paratransgenic tsetse confirmed that miR275 regulates processes related to the expression of PM-associated proteins and digestive enzymes as well as genes that encode abundant secretory proteins. Our study demonstrates that paratransgenesis can be employed to study microRNA regulated pathways in arthropods that house symbiotic bacteria.}, }
@article {pmid34103228, year = {2022}, author = {Elston, KM and Leonard, SP and Geng, P and Bialik, SB and Robinson, E and Barrick, JE}, title = {Engineering insects from the endosymbiont out.}, journal = {Trends in microbiology}, volume = {30}, number = {1}, pages = {79-96}, doi = {10.1016/j.tim.2021.05.004}, pmid = {34103228}, issn = {1878-4380}, mesh = {Animals ; Bacteria/genetics ; *Ecosystem ; *Insecta/microbiology ; Symbiosis ; }, abstract = {Insects are an incredibly diverse group of animals with species that benefit and harm natural ecosystems, agriculture, and human health. Many insects have consequential associations with microbes: bacterial symbionts may be embedded in different insect tissues and cell types, inherited across insect generations, and required for insect survival and reproduction. Genetically engineering insect symbionts is key to understanding and harnessing these associations. We summarize different types of insect-bacteria relationships and review methods used to genetically modify endosymbiont and gut symbiont species. Finally, we discuss recent studies that use this approach to study symbioses, manipulate insect-microbe interactions, and influence insect biology. Further progress in insect symbiont engineering promises to solve societal challenges, ranging from controlling pests to protecting pollinator health.}, }
@article {pmid34096774, year = {2022}, author = {Killiny, N}, title = {Made for Each Other: Vector-Pathogen Interfaces in the Huanglongbing Pathosystem.}, journal = {Phytopathology}, volume = {112}, number = {1}, pages = {26-43}, doi = {10.1094/PHYTO-05-21-0182-FI}, pmid = {34096774}, issn = {0031-949X}, mesh = {Animals ; *Citrus ; *Hemiptera ; Insect Vectors ; Plant Diseases ; *Rhizobiaceae ; }, abstract = {Citrus greening, or huanglongbing (HLB), currently is the most destructive disease of citrus. HLB disease is putatively caused by the phloem-restricted α-proteobacterium 'Candidatus Liberibacter asiaticus'. This bacterium is transmitted primarily by the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae). Most animal pathogens are considered pathogenic to their insect vectors, whereas the relationships between plant pathogens and their insect vectors are variable. Lately, the relationship of 'Ca. L. asiaticus' with its insect vector, D. citri, has been well investigated at the molecular, biochemical, and biological levels in many studies. Herein, the findings concerning this relationship are discussed and molecular features of the acquisition of 'Ca. L. asiaticus' from the plant host and its growth and circulation within D. citri, as well as its transmission to plants, are presented. In addition, the effects of 'Ca. L. asiaticus' on the energy metabolism (respiration, tricarboxylic acid cycle, and adenosine triphosphate production), metabolic pathways, immune system, endosymbionts, and detoxification enzymes of D. citri are discussed together with other impacts such as shorter lifespan, altered feeding behavior, and higher fecundity. Overall, although 'Ca. L. asiaticus' has significant negative effects on its insect vector, it increases its vector fitness, indicating that it develops a mutualistic relationship with its vector. This review will help in understanding the specific interactions between 'Ca. L. asiaticus' and its psyllid vector in order to design innovative management strategies.}, }
@article {pmid34084554, year = {2021}, author = {Huffmyer, AS and Johnson, CJ and Epps, AM and Lemus, JD and Gates, RD}, title = {Feeding and thermal conditioning enhance coral temperature tolerance in juvenile Pocillopora acuta.}, journal = {Royal Society open science}, volume = {8}, number = {5}, pages = {210644}, pmid = {34084554}, issn = {2054-5703}, abstract = {Scleractinian corals form the foundation of coral reefs by acquiring autotrophic nutrition from photosynthetic endosymbionts (Symbiodiniaceae) and use feeding to obtain additional nutrition, especially when the symbiosis is compromised (i.e. bleaching). Juvenile corals are vulnerable to stress due to low energetic reserves and high demand for growth, which is compounded when additional stressors occur. Therefore, conditions that favour energy acquisition and storage may enhance survival under stressful conditions. To investigate the influence of feeding on thermal tolerance, we exposed Pocillopora acuta juveniles to temperature (ambient, 27.4°C versus cool, 25.9°C) and feeding treatments (fed versus unfed) for 30 days post-settlement and monitored growth and physiology, followed by tracking survival under thermal stress. Feeding increased growth and resulted in thicker tissues and elevated symbiont fluorescence. Under high-temperature stress (31-60 days post-settlement; ca 30.1°C), corals that were fed and previously exposed to cool temperature had 33% higher survival than other treatment groups. These corals demonstrated reduced symbiont fluorescence, which may have provided protective effects under thermal stress. These results highlight that the impacts of feeding on coral physiology and stress tolerance are dependent on temperature and as oceans continue to warm, early life stages may experience shifts in feeding strategies to survive.}, }
@article {pmid34082325, year = {2021}, author = {Gao, X and Hu, F and Zhang, S and Luo, J and Zhu, X and Wang, L and Zhang, K and Li, D and Ji, J and Niu, L and Wu, C and Cui, J}, title = {Glyphosate exposure disturbs the bacterial endosymbiont community and reduces body weight of the predatory ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae).}, journal = {The Science of the total environment}, volume = {790}, number = {}, pages = {147847}, doi = {10.1016/j.scitotenv.2021.147847}, pmid = {34082325}, issn = {1879-1026}, mesh = {Animals ; Bacteria/genetics ; Body Weight ; *Coleoptera ; Crops, Agricultural ; Glycine/analogs &amp; derivatives ; Larva ; Plants, Genetically Modified ; Predatory Behavior ; RNA, Ribosomal, 16S/genetics ; }, abstract = {The predatory ladybird beetle, Harmonia axyridis, is a predominant natural enemy of pest insects in cotton fields. Commercialization of genetically modified crops has promoted the increased use of the herbicide glyphosate. In this study, to assess potential negative effects of glyphosate on beneficial non-target organisms in cotton fields, we first examined how glyphosate exposure affected the development and endosymbiotic bacterial community of H. axyridis. The results showed that the survival rate, development duration, pupation rate and emergence rate of H. axyridis under low and high concentrations of glyphosate exposure were not significantly changed, but glyphosate did significantly reduce the body weight of H. axyridis. Based on 16S rRNA sequencing, there were no significant differences in the diversity or richness of the endosymbiotic bacteria of H. axyridis before and after glyphosate exposure. The dominant bacterial phyla Firmicutes and Proteobacteria and genera Staphylococcus and Enterobacter remained the same regardless of treatment with glyphosate, however the abundance and copy number of these bacteria were altered. Glyphosate treatment significantly reduced the abundance and gene copy number of Staphylococcus and increased the abundance and gene copy number of Enterobacter. This is the first report demonstrating that glyphosate can reduce the body weight H. axyridis and alter the bacterial endosymbiont community by affecting the abundance and gene copy number of dominant bacteria.}, }
@article {pmid34078265, year = {2021}, author = {Alickovic, L and Johnson, KP and Boyd, BM}, title = {The reduced genome of a heritable symbiont from an ectoparasitic feather feeding louse.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {108}, pmid = {34078265}, issn = {2730-7182}, mesh = {Animals ; Bacteria/genetics ; Genome, Bacterial/genetics ; *Ischnocera ; *Parasites ; Symbiosis ; }, abstract = {BACKGROUND: Feather feeding lice are abundant and diverse ectoparasites that complete their entire life cycle on an avian host. The principal or sole source of nutrition for these lice is feathers. Feathers appear to lack four amino acids that the lice would require to complete development and reproduce. Several insect groups have acquired heritable and intracellular bacteria that can synthesize metabolites absent in an insect's diet, allowing insects to feed exclusively on nutrient-poor resources. Multiple species of feather feeding lice have been shown to harbor heritable and intracellular bacteria. We expected that these bacteria augment the louse's diet with amino acids and facilitated the evolution of these diverse and specialized parasites. Heritable symbionts of insects often have small genomes that contain a minimal set of genes needed to maintain essential cell functions and synthesize metabolites absent in the host insect's diet. Therefore, we expected the genome of a bacterial endosymbiont in feather lice would be small, but encode pathways for biosynthesis of amino acids.<br><br>RESULTS: We sequenced the genome of a bacterial symbiont from a feather feeding louse (Columbicola wolffhuegeli) that parasitizes the Pied Imperial Pigeon (Ducula bicolor) and used its genome to predict metabolism of amino acids based on the presence or absence of genes. We found that this bacterial symbiont has a small genome, similar to the genomes of heritable symbionts described in other insect groups. However, we failed to identify many of the genes that we expected would support metabolism of amino acids in the symbiont genome. We also evaluated other gene pathways and features of the highly reduced genome of this symbiotic bacterium.<br><br>CONCLUSIONS: Based on the data collected in this study, it does not appear that this bacterial symbiont can synthesize amino acids needed to complement the diet of a feather feeding louse. Our results raise additional questions about the biology of feather chewing lice and the roles of symbiotic bacteria in evolution of diverse avian parasites.}, }
@article {pmid34073039, year = {2021}, author = {Zhou, X and Ling, X and Guo, H and Zhu-Salzman, K and Ge, F and Sun, Y}, title = {Serratia symbiotica Enhances Fatty Acid Metabolism of Pea Aphid to Promote Host Development.}, journal = {International journal of molecular sciences}, volume = {22}, number = {11}, pages = {}, pmid = {34073039}, issn = {1422-0067}, mesh = {Animals ; *Aphids/metabolism/microbiology ; Fatty Acids/*metabolism ; *Host Microbial Interactions ; Serratia/*physiology ; *Symbiosis ; }, abstract = {Bacterial symbionts associated with insects are often involved in host development and ecological adaptation. Serratia symbiotica, a common facultative endosymbiont harbored in pea aphids, improves host fitness and heat tolerance, but studies concerning the nutritional metabolism and impact on the aphid host associated with carrying Serratia are limited. In the current study, we showed that Serratia-infected aphids had a shorter nymphal developmental time and higher body weight than Serratia-free aphids when fed on detached leaves. Genes connecting to fatty acid biosynthesis and elongation were up-regulated in Serratia-infected aphids. Specifically, elevated expression of fatty acid synthase 1 (FASN1) and diacylglycerol-o-acyltransferase 2 (DGAT2) could result in accumulation of myristic acid, palmitic acid, linoleic acid, and arachidic acid in fat bodies. Impairing fatty acid synthesis in Serratia-infected pea aphids either by a pharmacological inhibitor or through silencing FASN1 and DGAT2 expression prolonged the nymphal growth period and decreased the aphid body weight. Conversely, supplementation of myristic acid (C14:0) to these aphids restored their normal development and weight gain. Our results indicated that Serratia promoted development and growth of its aphid host through enhancing fatty acid biosynthesis. Our discovery has shed more light on nutritional effects underlying the symbiosis between aphids and facultative endosymbionts.}, }
@article {pmid34071987, year = {2021}, author = {Sato, N}, title = {Are Cyanobacteria an Ancestor of Chloroplasts or Just One of the Gene Donors for Plants and Algae?.}, journal = {Genes}, volume = {12}, number = {6}, pages = {}, pmid = {34071987}, issn = {2073-4425}, mesh = {Chlorophyta/*genetics ; Chloroplasts/*genetics ; Cyanobacteria/*genetics ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Peptidoglycan/genetics ; }, abstract = {Chloroplasts of plants and algae are currently believed to originate from a cyanobacterial endosymbiont, mainly based on the shared proteins involved in the oxygenic photosynthesis and gene expression system. The phylogenetic relationship between the chloroplast and cyanobacterial genomes was important evidence for the notion that chloroplasts originated from cyanobacterial endosymbiosis. However, studies in the post-genomic era revealed that various substances (glycolipids, peptidoglycan, etc.) shared by cyanobacteria and chloroplasts are synthesized by different pathways or phylogenetically unrelated enzymes. Membranes and genomes are essential components of a cell (or an organelle), but the origins of these turned out to be different. Besides, phylogenetic trees of chloroplast-encoded genes suggest an alternative possibility that chloroplast genes could be acquired from at least three different lineages of cyanobacteria. We have to seriously examine that the chloroplast genome might be chimeric due to various independent gene flows from cyanobacteria. Chloroplast formation could be more complex than a single event of cyanobacterial endosymbiosis. I present the "host-directed chloroplast formation" hypothesis, in which the eukaryotic host cell that had acquired glycolipid synthesis genes as an adaptation to phosphate limitation facilitated chloroplast formation by providing glycolipid-based membranes (pre-adaptation). The origins of the membranes and the genome could be different, and the origin of the genome could be complex.}, }
@article {pmid34070926, year = {2021}, author = {Mandon, K and Nazaret, F and Farajzadeh, D and Alloing, G and Frendo, P}, title = {Redox Regulation in Diazotrophic Bacteria in Interaction with Plants.}, journal = {Antioxidants (Basel, Switzerland)}, volume = {10}, number = {6}, pages = {}, pmid = {34070926}, issn = {2076-3921}, abstract = {Plants interact with a large number of microorganisms that greatly influence their growth and health. Among the beneficial microorganisms, rhizosphere bacteria known as Plant Growth Promoting Bacteria increase plant fitness by producing compounds such as phytohormones or by carrying out symbioses that enhance nutrient acquisition. Nitrogen-fixing bacteria, either as endophytes or as endosymbionts, specifically improve the growth and development of plants by supplying them with nitrogen, a key macro-element. Survival and proliferation of these bacteria require their adaptation to the rhizosphere and host plant, which are particular ecological environments. This adaptation highly depends on bacteria response to the Reactive Oxygen Species (ROS), associated to abiotic stresses or produced by host plants, which determine the outcome of the plant-bacteria interaction. This paper reviews the different antioxidant defense mechanisms identified in diazotrophic bacteria, focusing on their involvement in coping with the changing conditions encountered during interaction with plant partners.}, }
@article {pmid34067814, year = {2021}, author = {Vallino, M and Rossi, M and Ottati, S and Martino, G and Galetto, L and Marzachì, C and Abbà, S}, title = {Bacteriophage-Host Association in the Phytoplasma Insect Vector Euscelidius variegatus.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {5}, pages = {}, pmid = {34067814}, issn = {2076-0817}, abstract = {Insect vectors transmit viruses and bacteria that can cause severe diseases in plants and economic losses due to a decrease in crop production. Insect vectors, like all other organisms, are colonized by a community of various microorganisms, which can influence their physiology, ecology, evolution, and also their competence as vectors. The important ecological meaning of bacteriophages in various ecosystems and their role in microbial communities has emerged in the past decade. However, only a few phages have been described so far in insect microbiomes. The leafhopper Euscelidius variegatus is a laboratory vector of the phytoplasma causing Flavescence dorée, a severe grapevine disease that threatens viticulture in Europe. Here, the presence of a temperate bacteriophage in E. variegatus (named Euscelidius variegatus phage 1, EVP-1) was revealed through both insect transcriptome analyses and electron microscopic observations. The bacterial host was isolated in axenic culture and identified as the bacterial endosymbiont of E. variegatus (BEV), recently assigned to the genus Candidatus Symbiopectobacterium. BEV harbors multiple prophages that become active in culture, suggesting that different environments can trigger different mechanisms, finely regulating the interactions among phages. Understanding the complex relationships within insect vector microbiomes may help in revealing possible microbe influences on pathogen transmission, and it is a crucial step toward innovative sustainable strategies for disease management in agriculture.}, }
@article {pmid34066350, year = {2021}, author = {Liu, Q and Zhang, H and Zeng, L and Yu, Y and Lin, X and Huang, X}, title = {Coexistence of Three Dominant Bacterial Symbionts in a Social Aphid and Implications for Ecological Adaptation.}, journal = {Insects}, volume = {12}, number = {5}, pages = {}, pmid = {34066350}, issn = {2075-4450}, abstract = {Aphids are associated with an array of symbionts that have diverse ecological and evolutionary effects on their hosts. To date, symbiont communities of most aphid species are still poorly characterized, especially for the social aphids. In this study, high-throughput 16S rDNA amplicon sequencing was used to assess the bacterial communities of the social aphid Pseudoregma bambucicola, and the differences in bacterial diversity with respect to ant attendance and time series were also assessed. We found that the diversity of symbionts in P. bambucicola was low and three dominant symbionts (Buchnera, Pectobacterium and Wolbachia) were stably coexisting. Pectobacterium may help P. bambucicola feed on the hard bamboo stems, and genetic distance analysis suggests that the Pectobacterium in P. bambucicola may be a new symbiont species. Wolbachia may be associated with the transition of reproduction mode or has a nutritional role in P. bambucicola. Statistical tests on the diversity of bacterial communities in P. bambucicola suggest that aphid populations attended by ants usually have a significantly higher evenness than populations without ant attendance but there was no significant difference among aphid populations from different seasons.}, }
@article {pmid34065848, year = {2021}, author = {Lyu, D and Msimbira, LA and Nazari, M and Antar, M and Pagé, A and Shah, A and Monjezi, N and Zajonc, J and Tanney, CAS and Backer, R and Smith, DL}, title = {The Coevolution of Plants and Microbes Underpins Sustainable Agriculture.}, journal = {Microorganisms}, volume = {9}, number = {5}, pages = {}, pmid = {34065848}, issn = {2076-2607}, abstract = {Terrestrial plants evolution occurred in the presence of microbes, the phytomicrobiome. The rhizosphere microbial community is the most abundant and diverse subset of the phytomicrobiome and can include both beneficial and parasitic/pathogenic microbes. Prokaryotes of the phytomicrobiome have evolved relationships with plants that range from non-dependent interactions to dependent endosymbionts. The most extreme endosymbiotic examples are the chloroplasts and mitochondria, which have become organelles and integral parts of the plant, leading to some similarity in DNA sequence between plant tissues and cyanobacteria, the prokaryotic symbiont of ancestral plants. Microbes were associated with the precursors of land plants, green algae, and helped algae transition from aquatic to terrestrial environments. In the terrestrial setting the phytomicrobiome contributes to plant growth and development by (1) establishing symbiotic relationships between plant growth-promoting microbes, including rhizobacteria and mycorrhizal fungi, (2) conferring biotic stress resistance by producing antibiotic compounds, and (3) secreting microbe-to-plant signal compounds, such as phytohormones or their analogues, that regulate aspects of plant physiology, including stress resistance. As plants have evolved, they recruited microbes to assist in the adaptation to available growing environments. Microbes serve themselves by promoting plant growth, which in turn provides microbes with nutrition (root exudates, a source of reduced carbon) and a desirable habitat (the rhizosphere or within plant tissues). The outcome of this coevolution is the diverse and metabolically rich microbial community that now exists in the rhizosphere of terrestrial plants. The holobiont, the unit made up of the phytomicrobiome and the plant host, results from this wide range of coevolved relationships. We are just beginning to appreciate the many ways in which this complex and subtle coevolution acts in agricultural systems.}, }
@article {pmid34063663, year = {2021}, author = {Manocha, E and Caruso, A and Caccuri, F}, title = {Viral Proteins as Emerging Cancer Therapeutics.}, journal = {Cancers}, volume = {13}, number = {9}, pages = {}, pmid = {34063663}, issn = {2072-6694}, abstract = {Viruses are obligatory intracellular parasites that originated millions of years ago. Viral elements cover almost half of the human genome sequence and have evolved as genetic blueprints in humans. They have existed as endosymbionts as they are largely dependent on host cell metabolism. Viral proteins are known to regulate different mechanisms in the host cells by hijacking cellular metabolism to benefit viral replication. Amicable viral proteins, on the other hand, from several viruses can participate in mediating growth retardation of cancer cells based on genetic abnormalities while sparing normal cells. These proteins exert discreet yet converging pathways to regulate events like cell cycle and apoptosis in human cancer cells. This property of viral proteins could be harnessed for their use in cancer therapy. In this review, we discuss viral proteins from different sources as potential anticancer therapeutics.}, }
@article {pmid34061893, year = {2021}, author = {Yamashita, H and Koike, K and Shinzato, C and Jimbo, M and Suzuki, G}, title = {Can Acropora tenuis larvae attract native Symbiodiniaceae cells by green fluorescence at the initial establishment of symbiosis?.}, journal = {PloS one}, volume = {16}, number = {6}, pages = {e0252514}, pmid = {34061893}, issn = {1932-6203}, mesh = {Alveolata/*physiology ; Animals ; Anthozoa/*physiology ; Coral Reefs ; Dinoflagellida/physiology ; *Fluorescence ; Larva/*physiology ; Phototaxis/physiology ; Symbiosis/*physiology ; Ultraviolet Rays ; }, abstract = {Most corals acquire symbiodiniacean symbionts from the surrounding environment to initiate symbiosis. The cell densities of Symbiodiniaceae in the environment are usually low, and mechanisms may exist by which new coral generations attract suitable endosymbionts. Phototaxis of suitable symbiodiniacean cells toward green fluorescence in corals has been proposed as one such mechanism. In the present study, we observed the phototaxis action wavelength of various strains of Symbiodiniaceae and the fluorescence spectra of aposymbiotic Acropora tenuis larvae at the time of endosymbiont uptake. The phototaxis patterns varied among the Symbiodiniaceae species and "native" endosymbionts-commonly found in Acropora juveniles present in natural environments; that is, Symbiodinium microadriaticum was attracted to blue light rather than to green light. Another native endosymbiont, Durusdinium trenchii, showed no phototaxis specific to any wavelength. Although the larvae exhibited green and broad orange fluorescence under blue-violet excitation light, the maximum green fluorescence peak did not coincide with that of the phototaxis action spectrum of S. microadriaticum. Rather, around the peak wavelength of larval green fluorescence, this native endosymbiont showed slightly negative phototaxis, suggesting that the green fluorescence of A. tenuis larvae may not play a role in the initial attraction of native endosymbionts. Conversely, broad blue larval fluorescence under UV-A excitation covered the maximum phototaxis action wavelength of S. microadriaticum. We also conducted infection tests using native endosymbionts and aposymbiotic larvae under red LED light that does not excite visible larval fluorescence. Almost all larvae failed to acquire S. microadriaticum cells, whereas D. trenchii cells were acquired by larvae even under red illumination. Thus, attraction mechanisms other than visible fluorescence might exist, at least in the case of D. trenchii. Our results suggest that further investigation and discussion, not limited to green fluorescence, would be required to elucidate the initial attraction mechanisms.}, }
@article {pmid34061185, year = {2021}, author = {Garber, AI and Kupper, M and Laetsch, DR and Weldon, SR and Ladinsky, MS and Bjorkman, PJ and McCutcheon, JP}, title = {The Evolution of Interdependence in a Four-Way Mealybug Symbiosis.}, journal = {Genome biology and evolution}, volume = {13}, number = {8}, pages = {}, pmid = {34061185}, issn = {1759-6653}, support = {P50 AI150464/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Betaproteobacteria/genetics ; *Gammaproteobacteria/genetics ; Genome, Bacterial ; *Hemiptera/genetics/microbiology ; Phylogeny ; Symbiosis/genetics ; }, abstract = {Mealybugs are insects that maintain intracellular bacterial symbionts to supplement their nutrient-poor plant sap diets. Some mealybugs have a single betaproteobacterial endosymbiont, a Candidatus Tremblaya species (hereafter Tremblaya) that alone provides the insect with its required nutrients. Other mealybugs have two nutritional endosymbionts that together provision these same nutrients, where Tremblaya has gained a gammaproteobacterial partner that resides in its cytoplasm. Previous work had established that Pseudococcus longispinus mealybugs maintain not one but two species of gammaproteobacterial endosymbionts along with Tremblaya. Preliminary genomic analyses suggested that these two gammaproteobacterial endosymbionts have large genomes with features consistent with a relatively recent origin as insect endosymbionts, but the patterns of genomic complementarity between members of the symbiosis and their relative cellular locations were unknown. Here, using long-read sequencing and various types of microscopy, we show that the two gammaproteobacterial symbionts of P. longispinus are mixed together within Tremblaya cells, and that their genomes are somewhat reduced in size compared with their closest nonendosymbiotic relatives. Both gammaproteobacterial genomes contain thousands of pseudogenes, consistent with a relatively recent shift from a free-living to an endosymbiotic lifestyle. Biosynthetic pathways of key metabolites are partitioned in complex interdependent patterns among the two gammaproteobacterial genomes, the Tremblaya genome, and horizontally acquired bacterial genes that are encoded on the mealybug nuclear genome. Although these two gammaproteobacterial endosymbionts have been acquired recently in evolutionary time, they have already evolved codependencies with each other, Tremblaya, and their insect host.}, }
@article {pmid34059765, year = {2021}, author = {Detcharoen, M and Schilling, MP and Arthofer, W and Schlick-Steiner, BC and Steiner, FM}, title = {Differential gene expression in Drosophila melanogaster and D. nigrosparsa infected with the same Wolbachia strain.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {11336}, pmid = {34059765}, issn = {2045-2322}, mesh = {Animals ; Drosophila melanogaster/*metabolism/*microbiology ; Female ; *Gene Expression ; Gene Expression Profiling ; Species Specificity ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia are maternally inherited endosymbionts that infect nearly half of all arthropod species. Wolbachia manipulate their hosts to maximize their transmission, but they can also provide benefits such as nutrients and resistance against viruses to their hosts. The Wolbachia strain wMel was recently found to increase locomotor activities and possibly trigger cytoplasmic incompatibility in the transinfected fly Drosophila nigrosparsa. Here, we investigated, in females of both D. melanogaster and D. nigrosparsa, the gene expression between animals uninfected and infected with wMel, using RNA sequencing to see if the two Drosophila species respond to the infection in the same or different ways. A total of 2164 orthologous genes were used. The two fly species responded to the infection in different ways. Significant changes shared by the fly species belong to the expression of genes involved in processes such as oxidation-reduction process, iron-ion binding, and voltage-gated potassium-channel activity. We discuss our findings also in the light of how Wolbachia survive within both the native and the novel host.}, }
@article {pmid34058098, year = {2021}, author = {Paredes, GF and Viehboeck, T and Lee, R and Palatinszky, M and Mausz, MA and Reipert, S and Schintlmeister, A and Maier, A and Volland, JM and Hirschfeld, C and Wagner, M and Berry, D and Markert, S and Bulgheresi, S and König, L}, title = {Anaerobic Sulfur Oxidation Underlies Adaptation of a Chemosynthetic Symbiont to Oxic-Anoxic Interfaces.}, journal = {mSystems}, volume = {6}, number = {3}, pages = {e0118620}, pmid = {34058098}, issn = {2379-5077}, support = {P 28743/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Chemosynthetic symbioses occur worldwide in marine habitats, but comprehensive physiological studies of chemoautotrophic bacteria thriving on animals are scarce. Stilbonematinae are coated by thiotrophic Gammaproteobacteria. As these nematodes migrate through the redox zone, their ectosymbionts experience varying oxygen concentrations. However, nothing is known about how these variations affect their physiology. Here, by applying omics, Raman microspectroscopy, and stable isotope labeling, we investigated the effect of oxygen on "Candidatus Thiosymbion oneisti." Unexpectedly, sulfur oxidation genes were upregulated in anoxic relative to oxic conditions, but carbon fixation genes and incorporation of [13]C-labeled bicarbonate were not. Instead, several genes involved in carbon fixation were upregulated under oxic conditions, together with genes involved in organic carbon assimilation, polyhydroxyalkanoate (PHA) biosynthesis, nitrogen fixation, and urea utilization. Furthermore, in the presence of oxygen, stress-related genes were upregulated together with vitamin biosynthesis genes likely necessary to withstand oxidative stress, and the symbiont appeared to proliferate less. Based on its physiological response to oxygen, we propose that "Ca. T. oneisti" may exploit anaerobic sulfur oxidation coupled to denitrification to proliferate in anoxic sand. However, the ectosymbiont would still profit from the oxygen available in superficial sand, as the energy-efficient aerobic respiration would facilitate carbon and nitrogen assimilation. IMPORTANCE Chemoautotrophic endosymbionts are famous for exploiting sulfur oxidization to feed marine organisms with fixed carbon. However, the physiology of thiotrophic bacteria thriving on the surface of animals (ectosymbionts) is less understood. One longstanding hypothesis posits that attachment to animals that migrate between reduced and oxic environments would boost sulfur oxidation, as the ectosymbionts would alternatively access sulfide and oxygen, the most favorable electron acceptor. Here, we investigated the effect of oxygen on the physiology of "Candidatus Thiosymbion oneisti," a gammaproteobacterium which lives attached to marine nematodes inhabiting shallow-water sand. Surprisingly, sulfur oxidation genes were upregulated under anoxic relative to oxic conditions. Furthermore, under anoxia, the ectosymbiont appeared to be less stressed and to proliferate more. We propose that animal-mediated access to oxygen, rather than enhancing sulfur oxidation, would facilitate assimilation of carbon and nitrogen by the ectosymbiont.}, }
@article {pmid34056878, year = {2021}, author = {Wang, S and Hua, X and Cui, L}, title = {Characterization of microbiota diversity of engorged ticks collected from dogs in China.}, journal = {Journal of veterinary science}, volume = {22}, number = {3}, pages = {e37}, pmid = {34056878}, issn = {1976-555X}, support = {2017YFC1200202//National Key Research and Development Program of China/China ; PKJ2018-N02//Shanghai Pudong New Area Science and Technology Development Fund/China ; }, mesh = {*Animal Distribution ; Animals ; Bacteria/classification/*isolation &amp; purification ; Bacterial Physiological Phenomena ; China ; Dogs ; Female ; Ixodidae/*microbiology ; Male ; *Microbiota ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Sex Factors ; }, abstract = {BACKGROUND: Ticks are one of the most common external parasites in dogs, and are associated with the transmission of a number of major zoonoses, which result in serious harm to human health and even death. Also, the increasing number of pet dogs and pet owners in China has caused concern regarding human tick-borne illnesses. Accordingly, studies are needed to gain a complete understanding of the bacterial composition and diversity of the ticks that parasitize dogs.<br><br>OBJECTIVES: To date, there have been relatively few reports on the analysis of the bacterial community structure and diversity in ticks that parasitize dogs. The objective of this study was to investigate the microbial composition and diversity of parasitic ticks of dogs, and assessed the effect of tick sex and geographical region on the bacterial composition in two tick genera collected from dogs in China.<br><br>METHODS: A total of 178 whole ticks were subjected to a 16S ribosomal RNA (rRNA) next generation sequencing analysis. The Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene was used to characterize the bacterial communities of the collected ticks. Sequence analysis and taxonomic assignment were performed using QIIME 2 and the GreenGene database, respectively. After clustering the sequences into taxonomic units, the sequences were quality-filtered and rarefied.<br><br>RESULTS: After pooling 24 tick samples, we identified a total of 2,081 operational taxonomic units, which were assigned to 23 phyla and 328 genera, revealing a diverse bacterial community profile. The high, moderate and low prevalent taxa include 46, 101, and 182 genera, respectively. Among them, dominant taxa include environmental bacterial genera, such as Psychrobacter and Burkholderia. Additionally, some known tick-associated endosymbionts were also detected, including Coxiella, Rickettsia, and Ricketssiella. Also, the potentially pathogenic genera Staphylococcus and Pseudomonas were detected in the tick pools. Moreover, our preliminary study found that the differences in microbial communities are more dependent on the sampling location than tick sex in the tick specimens collected from dogs.<br><br>CONCLUSIONS: The findings of this study support the need for future research on the microbial population present in ticks collected from dogs in China.}, }
@article {pmid34054743, year = {2021}, author = {Chandra, S and Harvey, E and Emery, D and Holmes, EC and Šlapeta, J}, title = {Unbiased Characterization of the Microbiome and Virome of Questing Ticks.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {627327}, pmid = {34054743}, issn = {1664-302X}, abstract = {Due to their vector capacity, ticks are ectoparasites of medical and veterinary significance. Modern sequencing tools have facilitated tick-associated microbiota studies, but these have largely focused on bacterial pathogens and symbionts. By combining 16S rRNA gene sequencing with total RNA-sequencing methods, we aimed to determine the complete microbiome and virome of questing, female Ixodes holocyclus recovered from coastal, north-eastern New South Wales (NSW), Australia. We present, for the first time, a robust and unbiased method for the identification of novel microbes in ticks that enabled us to identify bacteria, viruses, fungi and eukaryotic pathogens. The dominant bacterial endosymbionts were Candidatus Midichloria sp. Ixholo1 and Candidatus Midichloria sp. Ixholo2. Candidatus Neoehrlichia australis and Candidatus Neoehrlichia arcana were also recovered, confirming that these bacteria encompass I. holocyclus' core microbiota. In addition, seven virus species were detected-four previously identified in I. holocyclus and three novel species. Notably, one of the four previously identified virus species has pathogenic potential based on its phylogenetic relationship to other tick-associated pathogens. No known pathogenic eukaryotes or fungi were identified. This study has revealed the microbiome and virome of female I. holocyclus from the environment in north-eastern NSW. We propose that future tick microbiome and virome studies utilize equivalent methods to provide an improved representation of the microbial diversity in ticks globally.}, }
@article {pmid34052226, year = {2021}, author = {Maeda, I and Kudou, S and Iwai, S}, title = {Efficient isolation and cultivation of endosymbiotic Chlorella from Paramecium bursaria on agar plates by co-culture with yeast cells.}, journal = {Journal of microbiological methods}, volume = {186}, number = {}, pages = {106254}, doi = {10.1016/j.mimet.2021.106254}, pmid = {34052226}, issn = {1872-8359}, mesh = {Chlorella/growth &amp; development/isolation &amp; purification/*physiology ; Coculture Techniques/*methods ; Paramecium/*parasitology/physiology ; Saccharomyces cerevisiae/genetics/*growth &amp; development ; *Symbiosis ; }, abstract = {Paramecium bursaria is a ciliate that harbors Chlorella-like unicellular green algae as endosymbionts. The relationship between the host P. bursaria and the endosymbiotic Chlorella is facultative; therefore, both partners can be cultured independently and re-combined to re-establish symbiosis, making this system suitable for studying algal endosymbiosis. However, despite many previous studies, cultivation of endosymbiotic Chlorella remains difficult, particularly on agar plates. Here we describe a simple agar plate method for efficiently isolating and culturing cells of the endosymbiotic alga Chlorella variabilis from an individual P. bursaria cell, by co-culturing them with yeast Saccharomyces cerevisiae. The co-culture with the yeast significantly improved the colony-forming efficiency of the alga on agar. Growth assays suggest that the main role of the co-cultured yeast cells is not to provide nutrients for the algal cells, but to protect the algal cells from some environmental stresses on the agar surface. Using the algal cells grown on the plates and a set of specially designed primers, direct colony PCR can be performed for screening of multiple endosymbiont clones isolated from a single host ciliate. These methods may provide a useful tool for studying endosymbiotic Chlorella species within P. bursaria and various other protists.}, }
@article {pmid34047357, year = {2021}, author = {Ün, &#xc7; and Schultner, E and Manzano-Marín, A and Flórez, LV and Seifert, B and Heinze, J and Oettler, J}, title = {Cytoplasmic incompatibility between Old and New World populations of a tramp ant.}, journal = {Evolution; international journal of organic evolution}, volume = {75}, number = {7}, pages = {1775-1791}, doi = {10.1111/evo.14261}, pmid = {34047357}, issn = {1558-5646}, mesh = {Animals ; *Ants/genetics ; Biological Evolution ; Cytoplasm ; Reproduction ; Symbiosis ; *Wolbachia ; }, abstract = {Reproductive manipulation by endosymbiotic Wolbachia can cause unequal inheritance, allowing the manipulator to spread and potentially impacting evolutionary dynamics in infected hosts. Tramp and invasive species are excellent models to study the dynamics of host-Wolbachia associations because introduced populations often diverge in their microbiomes after colonizing new habitats, resulting in infection polymorphisms between native and introduced populations. Ants are the most abundant group of insects on earth, and numerous ant species are classified as highly invasive. However, little is known about the role of Wolbachia in these ecologically dominant insects. Here, we provide the first description of reproductive manipulation by Wolbachia in an ant. We show that Old and New World populations of the cosmotropic tramp ant Cardiocondyla obscurior harbor distinct Wolbachia strains, and that only the Old World strain manipulates host reproduction by causing cytoplasmic incompatibility (CI) in hybrid crosses. By uncovering a symbiont-induced mechanism of reproductive isolation in a social insect, our study provides a novel perspective on the biology of tramp ants and introduces a new system for studying the evolutionary consequences of CI.}, }
@article {pmid34044867, year = {2021}, author = {Jiao, J and Lu, Z and Yu, Y and Ou, Y and Fu, M and Zhao, Y and Wu, N and Zhao, M and Liu, Y and Sun, Y and Wen, B and Zhou, D and Yuan, Q and Xiong, X}, title = {Identification of tick-borne pathogens by metagenomic next-generation sequencing in Dermacentor nuttalli and Ixodes persulcatus in Inner Mongolia, China.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {287}, pmid = {34044867}, issn = {1756-3305}, mesh = {Anaplasma/genetics/isolation &amp; purification ; Animals ; Arthropod Vectors/genetics ; Babesia/genetics ; Babesiosis/diagnosis ; Cattle ; Dermacentor/*genetics ; High-Throughput Nucleotide Sequencing/*methods ; Ixodes/classification/*genetics ; Ixodidae/genetics ; *Metagenomics ; Mongolia ; Polymerase Chain Reaction ; Rickettsia/genetics ; Rickettsia Infections/diagnosis/veterinary ; Tick-Borne Diseases/*diagnosis/parasitology ; }, abstract = {BACKGROUND: Hard ticks act as arthropod vectors in the transmission of human and animal pathogens and are widely distributed in northern China. The aim of this study is to screen the important tick-borne pathogens (TBPs) carried by hard ticks in Inner Mongolia using metagenomic next-generation sequencing (mNGS) and to estimate the risk of human infection imposed by tick bites.<br><br>METHODS: The adult Dermacentor nuttalli (n&#x2009;=&#x2009;203) and Ixodes persulcatus (n&#x2009;=&#x2009;36) ticks feeding on cattle were collected. The pooled DNA samples prepared from these ticks were sequenced as the templates for mNGS to survey the presence of TBPs at the genus level. Individual tick DNA samples were detected by genus--specific or group-specific nested polymerase chain reaction (PCR) of these TBPs and combined with DNA sequencing assay to confirm the results of mNGS.<br><br>RESULTS: R. raoultii (45.32%, 92/203), Candidatus R. tarasevichiae (5.42%, 11/203), Anaplasma sp. Mongolia (26.60%, 54/203), Coxiella-like endosymbiont (CLE) (53.69%, 109/203), and Babesia venatorum (7.88%, 16/203) were detected in D. nuttalli, while R. raoultii (30.56%, 11/36), Anaplasma sp. Mongolia (27.80%, 10/36), and CLE (27.80%, 10/36) were detected in I. persulcatus. The double- and triple-pathogen/endosymbiont co-infections were detected in 40.39% of D. nuttalli and 13.89% of I. persulcatus, respectively. The dual co-infection with R. raoultii and CLE (14.29%, 29/203) and triple co-infection with R. raoultii, Anaplasma sp. Mongolia, and CLE (13.79%, 28/203) were most frequent in D. nuttalli.<br><br>CONCLUSIONS: This study provides insight into the microbial diversity of D. nuttalli and I. persulcatus in Inner Mongolia, China, reporting for the first time that Candidatus R. tarasevichiae had been found in D. nuttalli in China, and for the first time in the world that Anaplasma sp. Mongolia has been detected in I. persulcatus. This study proves that various vertically transmitted pathogens co-inhabit D. nuttalli and I. persulcatus, and indicates that cattle in Inner Mongolia are exposed to several TBPs.}, }
@article {pmid34040152, year = {2021}, author = {Fukuda, K and Yamasaki, K and Ogura, Y and Kawanami, T and Ikegami, H and Noguchi, S and Akata, K and Katsura, K and Yatera, K and Mukae, H and Hayashi, T and Taniguchi, H}, title = {A human respiratory tract-associated bacterium with an extremely small genome.}, journal = {Communications biology}, volume = {4}, number = {1}, pages = {628}, pmid = {34040152}, issn = {2399-3642}, mesh = {Bacteria/genetics ; Base Composition/genetics ; Genome, Bacterial/*genetics ; Genome, Human/genetics ; Humans ; Phylogeny ; Respiratory System/*microbiology ; Respiratory Tract Diseases/genetics/microbiology ; Rickettsiales/*genetics/pathogenicity ; Whole Genome Sequencing/methods ; }, abstract = {Recent advances in culture-independent microbiological analyses have greatly expanded our understanding of the diversity of unculturable microbes. However, human pathogenic bacteria differing significantly from known taxa have rarely been discovered. Here, we present the complete genome sequence of an uncultured bacterium detected in human respiratory tract named IOLA, which was determined by developing a protocol to selectively amplify extremely AT-rich genomes. The IOLA genome is 303,838 bp in size with a 20.7% GC content, making it the smallest and most AT-rich genome among known human-associated bacterial genomes to our best knowledge and comparable to those of insect endosymbionts. While IOLA belongs to order Rickettsiales (mostly intracellular parasites), the gene content suggests an epicellular parasitic lifestyle. Surveillance of clinical samples provides evidence that IOLA can be predominantly detected in patients with respiratory bacterial infections and can persist for at least 15 months in the respiratory tract, suggesting that IOLA is a human respiratory tract-associated bacterium.}, }
@article {pmid34022346, year = {2021}, author = {Kohli, S and Gulati, P and Narang, A and Maini, J and Shamsudheen, KV and Pandey, R and Scaria, V and Sivasubbu, S and Brahmachari, V}, title = {Genome and transcriptome analysis of the mealybug Maconellicoccus hirsutus: Correlation with its unique phenotypes.}, journal = {Genomics}, volume = {113}, number = {4}, pages = {2483-2494}, doi = {10.1016/j.ygeno.2021.05.014}, pmid = {34022346}, issn = {1089-8646}, mesh = {Animals ; Female ; Gene Expression Profiling ; Genome ; *Hemiptera/genetics ; Male ; Phenotype ; Symbiosis ; Transcriptome ; }, abstract = {Mealybugs are aggressive pests with world-wide distribution and are suitable for the study of different phenomena like genomic imprinting and epigenetics. Genomic approaches facilitate these studies in absence of robust genetics in this system. We sequenced, de novo assembled, annotated Maconellicoccus hirsutus genome. We carried out comparative genomics it with four mealybug and eight other insect species, to identify expanded, specific and contracted gene classes that relate to pesticide and desiccation resistance. We identified horizontally transferred genes adding to the mutualism between the mealybug and its endosymbionts. Male and female transcriptome analysis indicates differential expression of metabolic pathway genes correlating with their physiology and the genes for sexual dimorphism. The significantly lower expression of endosymbiont genes in males relates to the depletion of endosymbionts in males during development.}, }
@article {pmid34020585, year = {2021}, author = {Lucek, K and Bouaouina, S and Jospin, A and Grill, A and de Vos, JM}, title = {Prevalence and relationship of endosymbiotic Wolbachia in the butterfly genus Erebia.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {95}, pmid = {34020585}, issn = {2730-7182}, mesh = {Animals ; *Butterflies ; Phylogeny ; Prevalence ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Wolbachia is an endosymbiont common to most invertebrates, which can have significant evolutionary implications for its host species by acting as a barrier to gene flow. Despite the importance of Wolbachia, still little is known about its prevalence and diversification pattern among closely related host species. Wolbachia strains may phylogenetically coevolve with their hosts, unless horizontal host-switches are particularly common. We address these issues in the genus Erebia, one of the most diverse Palearctic butterfly genera.<br><br>RESULTS: We sequenced the Wolbachia genome from a strain infecting Erebia cassioides and showed that it belongs to the Wolbachia supergroup B, capable of infecting arthropods from different taxonomic orders. The prevalence of Wolbachia across 13 closely related Erebia host species based on extensive population-level genetic data revealed that multiple Wolbachia strains jointly infect all investigated taxa, but with varying prevalence. Finally, the phylogenetic relationships of Wolbachia strains are in some cases significantly associated to that of their hosts, especially among the most closely related Erebia species, demonstrating mixed evidence for phylogenetic coevolution.<br><br>CONCLUSIONS: Closely related host species can be infected by closely related Wolbachia strains, evidencing some phylogenetic coevolution, but the actual pattern of infection more often reflects historical or contemporary geographic proximity among host species. Multiple processes, including survival in distinct glacial refugia, recent host shifts in sympatry, and a loss of Wolbachia during postglacial range expansion seem to have jointly shaped the complex interactions between Wolbachia evolution and the diversification of its host among our studied Erebia species.}, }
@article {pmid34018613, year = {2021}, author = {Stephens, TG and Gabr, A and Calatrava, V and Grossman, AR and Bhattacharya, D}, title = {Why is primary endosymbiosis so rare?.}, journal = {The New phytologist}, volume = {231}, number = {5}, pages = {1693-1699}, pmid = {34018613}, issn = {1469-8137}, support = {80NSSC19K0462/ImNASA/Intramural NASA/United States ; }, mesh = {*Amoeba ; Biological Evolution ; Eukaryota ; Phylogeny ; Plastids ; *Symbiosis ; }, abstract = {Endosymbiosis is a relationship between two organisms wherein one cell resides inside the other. This affiliation, when stable and beneficial for the 'host' cell, can result in massive genetic innovation with the foremost examples being the evolution of eukaryotic organelles, the mitochondria and plastids. Despite its critical evolutionary role, there is limited knowledge about how endosymbiosis is initially established and how host-endosymbiont biology is integrated. Here, we explore this issue, using as our model the rhizarian amoeba Paulinella, which represents an independent case of primary plastid origin that occurred c. 120 million yr ago. We propose the 'chassis and engine' model that provides a theoretical framework for understanding primary plastid endosymbiosis, potentially explaining why it is so rare.}, }
@article {pmid34015229, year = {2021}, author = {Mioduchowska, M and Nitkiewicz, B and Roszkowska, M and Kačarević, U and Madanecki, P and Pinceel, T and Namiotko, T and Gołdyn, B and Kaczmarek, &#x141;}, title = {Taxonomic classification of the bacterial endosymbiont Wolbachia based on next-generation sequencing: is there molecular evidence for its presence in tardigrades?.}, journal = {Genome}, volume = {64}, number = {10}, pages = {951-958}, doi = {10.1139/gen-2020-0036}, pmid = {34015229}, issn = {1480-3321}, mesh = {Animals ; High-Throughput Nucleotide Sequencing ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Tardigrada/*microbiology ; *Wolbachia/classification ; }, abstract = {We used high-throughput sequencing of 16S rRNA to test whether tardigrade species are infected with Wolbachia parasites. We applied SILVA and Greengenes databases that allowed taxonomic classification of bacterial sequences to OTUs. The results obtained from both databases differed considerably in the number of OTUs, and only the Greengenes database allowed identification of Wolbachia (infection was also supported by comparison of sequences to NCBI database). The putative bacterial endosymbiont Wolbachia was discovered only in adult eutardigrades, while bacteria identified down to the order Rickettsiales were detected in both eutardigrade eggs and adult specimens. Nevertheless, the frequency of Wolbachia in the bacterial communities of the studied eutardigrades was low. Similarly, in our positive control, i.e., a fairy shrimp Streptocephalus cafer, which was found to be infected with Wolbachia in our previous study using Sanger sequencing, only the Rickettsiales were detected. We also carried out phylogenetic reconstruction using Wolbachia sequences from the SILVA and Greengenes databases, Alphaproteobacteria putative endosymbionts and Rickettsiales OTUs obtained in previous studies on the microbial community of tardigrades, and Rickettsiales and Wolbachia OTUs obtained in the current study. Our discovery of Wolbachia in tardigrades can fuel new research to uncover the specifics of this interaction.}, }
@article {pmid34013860, year = {2021}, author = {Huebl, L and Tappe, D and Giese, M and Mempel, S and Tannich, E and Kreuels, B and Ramharter, M and Veletzky, L and Jochum, J}, title = {Recurrent Swelling and Microfilaremia Caused by Dirofilaria repens Infection after Travel to India.}, journal = {Emerging infectious diseases}, volume = {27}, number = {6}, pages = {1701-1704}, pmid = {34013860}, issn = {1080-6059}, mesh = {Animals ; *Dirofilaria repens ; *Dirofilariasis ; Germany ; Humans ; India ; Travel ; }, abstract = {Human subcutaneous dirofilariasis is an emerging mosquitoborne zoonosis. A traveler returning to Germany from India experienced Dirofilaria infection with concomitant microfilaremia. Molecular analysis indicated Dirofilaria repens nematodes of an Asian genotype. Microfilaremia showed no clear periodicity. Presence of Wolbachia endosymbionts enabled successful treatment with doxycycline.}, }
@article {pmid34012059, year = {2021}, author = {Ulrich, GF and Zemp, N and Vorburger, C and Boulain, H}, title = {Quantitative trait locus analysis of parasitoid counteradaptation to symbiont-conferred resistance.}, journal = {Heredity}, volume = {127}, number = {2}, pages = {219-232}, pmid = {34012059}, issn = {1365-2540}, mesh = {Animals ; *Aphids/genetics ; Enterobacteriaceae ; Female ; Quantitative Trait Loci ; Symbiosis ; *Wasps/genetics ; }, abstract = {Insect hosts and parasitoids are engaged in an intense struggle of antagonistic coevolution. Infection with heritable bacterial endosymbionts can substantially increase the resistance of aphids to parasitoid wasps, which exerts selection on parasitoids to overcome this symbiont-conferred protection (counteradaptation). Experimental evolution in the laboratory has produced counteradapted populations of the parasitoid wasp Lysiphlebus fabarum. These populations can parasitize black bean aphids (Aphis fabae) protected by the bacterial endosymbiont Hamiltonella defensa, which confers high resistance against L. fabarum. We used two experimentally evolved parasitoid populations to study the genetic architecture of the counteradaptation to symbiont-conferred resistance by QTL analysis. With simple crossing experiments, we showed that the counteradaptation is a recessive trait depending on the maternal genotype. Based on these results, we designed a customized crossing scheme to genotype a mapping population phenotyped for the ability to parasitize Hamiltonella-protected aphids. Using 1835 SNP markers obtained by ddRAD sequencing, we constructed a high-density linkage map consisting of six linkage groups (LGs) with an overall length of 828.3 cM and an average marker spacing of 0.45 cM. We identified a single QTL associated with the counteradaptation to Hamiltonella in L. fabarum on linkage group 2. Out of 120 genes located in this QTL, several genes encoding putative venoms may represent candidates for counteradaptation, as parasitoid wasps inject venoms into their hosts during oviposition.}, }
@article {pmid34009306, year = {2021}, author = {Brenner, AE and Muñoz-Leal, S and Sachan, M and Labruna, MB and Raghavan, R}, title = {Coxiella burnetii and Related Tick Endosymbionts Evolved from Pathogenic Ancestors.}, journal = {Genome biology and evolution}, volume = {13}, number = {7}, pages = {}, pmid = {34009306}, issn = {1759-6653}, support = {R03 AI123464/AI/NIAID NIH HHS/United States ; R03 AI133023/AI/NIAID NIH HHS/United States ; R15 AI126385/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Argasidae/microbiology ; Coxiella/genetics ; *Coxiella burnetii/genetics ; Symbiosis ; *Ticks ; }, abstract = {Both symbiotic and pathogenic bacteria in the family Coxiellaceae cause morbidity and mortality in humans and animals. For instance, Coxiella-like endosymbionts (CLEs) improve the reproductive success of ticks-a major disease vector, while Coxiella burnetii causes human Q fever, and uncharacterized coxiellae infect both animals and humans. To better understand the evolution of pathogenesis and symbiosis in this group of intracellular bacteria, we sequenced the genome of a CLE present in the soft tick Ornithodoros amblus (CLEOA) and compared it to the genomes of other bacteria in the order Legionellales. Our analyses confirmed that CLEOA is more closely related to C. burnetii, the human pathogen, than to CLEs in hard ticks, and showed that most clades of CLEs contain both endosymbionts and pathogens, indicating that several CLE lineages have evolved independently from pathogenic Coxiella. We also determined that the last common ancestorof CLEOA and C. burnetii was equipped to infect macrophages and that even though horizontal gene transfer (HGT) contributed significantly to the evolution of C. burnetii, most acquisition events occurred primarily in ancestors predating the CLEOA-C. burnetii divergence. These discoveries clarify the evolution of C. burnetii, which previously was assumed to have emerged when an avirulent tick endosymbiont recently gained virulence factors via HGT. Finally, we identified several metabolic pathways, including heme biosynthesis, that are likely critical to the intracellular growth of the human pathogen but not the tick symbiont, and show that the use of heme analog is a promising approach to controlling C. burnetii infections.}, }
@article {pmid34008202, year = {2021}, author = {Speijer, D}, title = {Zombie ideas about early endosymbiosis: Which entry mechanisms gave us the "endo" in different endosymbionts?.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {43}, number = {7}, pages = {e2100069}, doi = {10.1002/bies.202100069}, pmid = {34008202}, issn = {1521-1878}, mesh = {Bacteria/genetics ; Biological Evolution ; Eukaryota ; *Eukaryotic Cells ; Phylogeny ; *Symbiosis ; }, abstract = {Recently, a review regarding the mechanics and evolution of mitochondrial fission appeared in Nature. Surprisingly, it stated authoritatively that the mitochondrial outer membrane, in contrast with the inner membrane of bacterial descent, was acquired from the host, presumably during uptake. However, it has been known for quite some time that this membrane was also derived from the Gram-negative, alpha-proteobacterium related precursor of present-day mitochondria. The zombie idea of the host membrane still surrounding the endosymbiont is not only wrong, but more importantly, might hamper the proper conception of possible scenarios of eukaryogenesis. Why? Because it steers the imagination not only with regard to possible uptake mechanisms, but also regarding what went on before. Here I critically discuss both the evidence for the continuity of the bacterial outer membrane, the reasons for the persistence of the erroneous host membrane hypothesis and the wider implications of these misconceptions for the ideas regarding events occurring during the first steps towards the evolution of the eukaryotes and later major eukaryotic differentiations. I will also highlight some of the latest insights regarding different instances of endosymbiont evolution.}, }
@article {pmid34007993, year = {2021}, author = {Nadolny, RM and Kennedy, AC and Rodgers, JM and Vincent, ZT and Cornman, H and Haynes, SA and Casal, C and Robbins, RG and Richards, AL and Jiang, J and Farris, CM}, title = {Carios kelleyi (Acari: Ixodida: Argasidae) Infected With Rickettsial Agents Documented Infesting Housing in Kansas, United States.}, journal = {Journal of medical entomology}, volume = {58}, number = {6}, pages = {2398-2405}, doi = {10.1093/jme/tjab069}, pmid = {34007993}, issn = {1938-2928}, mesh = {Animals ; Argasidae/growth &amp; development/*microbiology ; Female ; Housing ; Kansas ; Male ; Nymph/growth &amp; development/microbiology ; Rickettsia/*isolation &amp; purification ; Tick Infestations/*parasitology ; }, abstract = {During September-December 2018, 25 live ticks were collected on-post at Fort Leavenworth, Kansas, in a home with a history of bat occupancy. Nine ticks were sent to the Army Public Health Center Tick-Borne Disease Laboratory and were identified as Carios kelleyi (Cooley and Kohls, 1941), a species that seldom bites humans but that may search for other sources of blood meals, including humans, when bats are removed from human dwellings. The ticks were tested for numerous agents of human disease. Rickettsia lusitaniae was identified by multilocus sequence typing to be present in two ticks, marking the first detection of this Rickettsia agent in the United States and in this species of tick. Two other Rickettsia spp. were also detected, including an endosymbiont previously associated with C. kelleyi and a possible novel Rickettsia species. The potential roles of C. kelleyi and bats in peridomestic Rickettsia transmission cycles warrant further investigation.}, }
@article {pmid34006882, year = {2021}, author = {Schrader, L and Pan, H and Bollazzi, M and Schiøtt, M and Larabee, FJ and Bi, X and Deng, Y and Zhang, G and Boomsma, JJ and Rabeling, C}, title = {Relaxed selection underlies genome erosion in socially parasitic ant species.}, journal = {Nature communications}, volume = {12}, number = {1}, pages = {2918}, pmid = {34006882}, issn = {2041-1723}, mesh = {Animals ; Ants/classification/*genetics/physiology ; Evolution, Molecular ; Female ; Gene Rearrangement/genetics ; Genome, Insect/*genetics ; Genomics/methods ; Host-Parasite Interactions ; Insect Proteins/classification/genetics ; Male ; Parasites/classification/*genetics/physiology ; Phylogeny ; Receptors, Odorant/classification/genetics ; *Social Behavior ; Species Specificity ; }, abstract = {Inquiline ants are highly specialized and obligate social parasites that infiltrate and exploit colonies of closely related species. They have evolved many times convergently, are often evolutionarily young lineages, and are almost invariably rare. Focusing on the leaf-cutting ant genus Acromyrmex, we compared genomes of three inquiline social parasites with their free-living, closely-related hosts. The social parasite genomes show distinct signatures of erosion compared to the host lineages, as a consequence of relaxed selective constraints on traits associated with cooperative ant colony life and of inquilines having very small effective population sizes. We find parallel gene losses, particularly in olfactory receptors, consistent with inquiline species having highly reduced social behavioral repertoires. Many of the genomic changes that we uncover resemble those observed in the genomes of obligate non-social parasites and intracellular endosymbionts that branched off into highly specialized, host-dependent niches.}, }
@article {pmid34003269, year = {2021}, author = {Baião, GC and Janice, J and Galinou, M and Klasson, L}, title = {Comparative Genomics Reveals Factors Associated with Phenotypic Expression of Wolbachia.}, journal = {Genome biology and evolution}, volume = {13}, number = {7}, pages = {}, pmid = {34003269}, issn = {1759-6653}, mesh = {Animals ; Cytoplasm/genetics ; Female ; Genomics ; Male ; Phenotype ; Symbiosis/genetics ; *Wolbachia/genetics ; }, abstract = {Wolbachia is a widespread, vertically transmitted bacterial endosymbiont known for manipulating arthropod reproduction. Its most common form of reproductive manipulation is cytoplasmic incompatibility (CI), observed when a modification in the male sperm leads to embryonic lethality unless a compatible rescue factor is present in the female egg. CI attracts scientific attention due to its implications for host speciation and in the use of Wolbachia for controlling vector-borne diseases. However, our understanding of CI is complicated by the complexity of the phenotype, whose expression depends on both symbiont and host factors. In the present study, we perform a comparative analysis of nine complete Wolbachia genomes with known CI properties in the same genetic host background, Drosophila simulans STC. We describe genetic differences between closely related strains and uncover evidence that phages and other mobile elements contribute to the rapid evolution of both genomes and phenotypes of Wolbachia. Additionally, we identify both known and novel genes associated with the modification and rescue functions of CI. We combine our observations with published phenotypic information and discuss how variability in cif genes, novel CI-associated genes, and Wolbachia titer might contribute to poorly understood aspects of CI such as strength and bidirectional incompatibility. We speculate that high titer CI strains could be better at invading new hosts already infected with a CI Wolbachia, due to a higher rescue potential, and suggest that titer might thus be a relevant parameter to consider for future strategies using CI Wolbachia in biological control.}, }
@article {pmid33984469, year = {2021}, author = {Chow, LH and De Grave, S and Tsang, LM}, title = {Evolution of protective symbiosis in palaemonid shrimps (Decapoda: Caridea) with emphases on host spectrum and morphological adaptations.}, journal = {Molecular phylogenetics and evolution}, volume = {162}, number = {}, pages = {107201}, doi = {10.1016/j.ympev.2021.107201}, pmid = {33984469}, issn = {1095-9513}, mesh = {Adaptation, Biological/*genetics ; Animals ; *Host Specificity ; Palaemonidae/*classification/*genetics ; *Phylogeny ; *Symbiosis/genetics ; }, abstract = {Palaemonidae is the most speciose caridean shrimp family, with its huge biodiversity partially generated via symbiosis with various marine invertebrates. Previous studies have provided insights into the evolution of protective symbiosis in this family with evidence for frequent inter-phyla host switches, but the comprehensiveness of evolutionary pathways is hampered by the resolution of the previous phylogenetic trees as well as the taxon coverage. Furthermore, several critical issues related to the evolution of a symbiotic lifestyle, including the change in host spectrum and corresponding morphological adaptations, remain largely unresolved. We therefore performed a much extended phylogenetic comparative study on Palaemonidae, rooted in a comprehensive phylogeny reconstructed by a supermatrix-supertree approach based on a total of three mitochondrial and five nuclear markers. Ancestral state reconstruction of host associations revealed at least three independent evolutions into symbiosis, with potentially a drive to seek protection fuelling incipient symbiosis. Yet, most of the observed symbiotic species diversity was radiated from a single cnidarian associate. The evolution of mandibles and ambulatory dactyli suggests a general lack of correlation with host affiliation (except sponge endosymbionts), implying limited morphological adaptations following host switching, despite being putatively a major adaptive consequence of symbiosis. Our analyses of host spectrum, in terms of basic and taxonomic specificity, revealed no apparent phylogenetic signal but instead resolved a dynamic pattern attributable to frequent host switching. Uncoupling between host spectrum and the degree of morphological specialisation is the norm in palaemonids, suggesting that morphological characters are not fully in tune with host spectrum, in addition to host affiliation. This study demonstrates the complexity in the evolution of symbiosis, pointing to the presence of cryptic adaptations determining host spectrum and governing host switch diversification, and provides a clear direction for the evolutionary study of symbiosis in other marine symbiotic groups involving host switching.}, }
@article {pmid33981744, year = {2021}, author = {Körner, S and Makert, GR and Ulbert, S and Pfeffer, M and Mertens-Scholz, K}, title = {The Prevalence of Coxiella burnetii in Hard Ticks in Europe and Their Role in Q Fever Transmission Revisited-A Systematic Review.}, journal = {Frontiers in veterinary science}, volume = {8}, number = {}, pages = {655715}, pmid = {33981744}, issn = {2297-1769}, abstract = {The zoonosis Q fever is caused by the obligate intracellular bacterium Coxiella burnetii. Besides the main transmission route via inhalation of contaminated aerosols, ticks are discussed as vectors since the first isolation of the pathogen from a Dermacentor andersonii tick. The rare detection of C. burnetii in ticks and the difficult differentiation of C. burnetii from Coxiella-like endosymbionts (CLEs) are questioning the relevance of ticks in the epidemiology of Q fever. In this review, literature databases were systematically searched for recent prevalence studies concerning C. burnetii in ticks in Europe and experimental studies evaluating the vector competence of tick species. A total of 72 prevalence studies were included and evaluated regarding DNA detection methods and collection methods, country, and tested tick species. Specimens of more than 25 different tick species were collected in 23 European countries. Overall, an average prevalence of 4.8% was determined. However, in half of the studies, no Coxiella-DNA was detected. In Southern European countries, a significantly higher prevalence was observed, possibly related to the abundance of different tick species here, namely Hyalomma spp. and Rhipicephalus spp. In comparison, a similar proportion of studies used ticks sampled by flagging and dragging or tick collection from animals, under 30% of the total tick samples derived from the latter. There was no significant difference in the various target genes used for the molecular test. In most of the studies, no distinction was made between C. burnetii and CLEs. The application of specific detection methods and the confirmation of positive results are crucial to determine the role of ticks in Q fever transmission. Only two studies were available, which assessed the vector competence of ticks for C. burnetii in the last 20 years, demonstrating the need for further research.}, }
@article {pmid33976379, year = {2021}, author = {Kiefer, JST and Batsukh, S and Bauer, E and Hirota, B and Weiss, B and Wierz, JC and Fukatsu, T and Kaltenpoth, M and Engl, T}, title = {Inhibition of a nutritional endosymbiont by glyphosate abolishes mutualistic benefit on cuticle synthesis in Oryzaephilus surinamensis.}, journal = {Communications biology}, volume = {4}, number = {1}, pages = {554}, pmid = {33976379}, issn = {2399-3642}, mesh = {Animal Scales/metabolism ; Animals ; Coleoptera/*metabolism/physiology ; Glycine/*analogs &amp; derivatives/metabolism/pharmacology ; Herbicides ; Phylogeny ; Shikimic Acid/metabolism ; Symbiosis/drug effects/*physiology ; }, abstract = {Glyphosate is widely used as a herbicide, but recent studies begin to reveal its detrimental side effects on animals by targeting the shikimate pathway of associated gut microorganisms. However, its impact on nutritional endosymbionts in insects remains poorly understood. Here, we sequenced the tiny, shikimate pathway encoding symbiont genome of the sawtoothed grain beetle Oryzaephilus surinamensis. Decreased titers of the aromatic amino acid tyrosine in symbiont-depleted beetles underscore the symbionts' ability to synthesize prephenate as the precursor for host tyrosine synthesis and its importance for cuticle sclerotization and melanization. Glyphosate exposure inhibited symbiont establishment during host development and abolished the mutualistic benefit on cuticle synthesis in adults, which could be partially rescued by dietary tyrosine supplementation. Furthermore, phylogenetic analyses indicate that the shikimate pathways of many nutritional endosymbionts likewise contain a glyphosate sensitive 5-enolpyruvylshikimate-3-phosphate synthase. These findings highlight the importance of symbiont-mediated tyrosine supplementation for cuticle biosynthesis in insects, but also paint an alarming scenario regarding the use of glyphosate in light of recent declines in insect populations.}, }
@article {pmid33975971, year = {2021}, author = {Domínguez-Santos, R and Pérez-Cobas, AE and Cuti, P and Pérez-Brocal, V and García-Ferris, C and Moya, A and Latorre, A and Gil, R}, title = {Interkingdom Gut Microbiome and Resistome of the Cockroach Blattella germanica.}, journal = {mSystems}, volume = {6}, number = {3}, pages = {}, pmid = {33975971}, issn = {2379-5077}, abstract = {Cockroaches are intriguing animals with two coexisting symbiotic systems, an endosymbiont in the fat body, involved in nitrogen metabolism, and a gut microbiome whose diversity, complexity, role, and developmental dynamics have not been fully elucidated. In this work, we present a metagenomic approach to study Blattella germanica populations not treated, treated with kanamycin, and recovered after treatment, both naturally and by adding feces to the diet, with the aim of better understanding the structure and function of its gut microbiome along the development as well as the characterization of its resistome.IMPORTANCE For the first time, we analyze the interkingdom hindgut microbiome of this species, including bacteria, fungi, archaea, and viruses. Network analysis reveals putative cooperation between core bacteria that could be key for ecosystem equilibrium. We also show how antibiotic treatments alter microbiota diversity and function, while both features are restored after one untreated generation. Combining data from B. germanica treated with three antibiotics, we have characterized this species' resistome. It includes genes involved in resistance to several broad-spectrum antibiotics frequently used in the clinic. The presence of genetic elements involved in DNA mobilization indicates that they can be transferred among microbiota partners. Therefore, cockroaches can be considered reservoirs of antibiotic resistance genes (ARGs) and potential transmission vectors.}, }
@article {pmid33963929, year = {2021}, author = {Yang, F and Zhang, J and Cai, Z and Zhou, J and Li, Y}, title = {Exploring the oxygenase function of Form II Rubisco for production of glycolate from CO2.}, journal = {AMB Express}, volume = {11}, number = {1}, pages = {65}, pmid = {33963929}, issn = {2191-0855}, abstract = {The oxygenase activity of Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) converts ribulose-1,5-bisphosphate (RuBP) into 2-phosphoglycolate, which in turn channels into photorespiration, resulting in carbon and energy loss in higher plants. We observed that glycolate can be accumulated extracellularly when two genes encoding the glycolate dehydrogenase of cyanobacteria Synechocystis sp. PCC 6803 were inactivated. This inspired us to explore the oxygenase function of Rubisco for production of glycolate, an important industrial chemical, from CO2 by engineered cyanobacteria. Since the oxygenase activity of Rubisco is generally low in CO2-rich carboxysome of cyanobacteria, we introduced Form II Rubisco, which cannot be assembled in carboxysome, into the cytoplasm of cyanobacteria. Heterologous expression of a Form II Rubisco from endosymbiont of tubeworm Riftia pachyptila (RPE Rubisco) significantly increased glycolate production. We show that the RPE Rubisco is expressed in the cytoplasm. Glycolate production increased upon addition of NaHCO3 but decreased upon supplying CO2. The titer of glycolate reached 2.8 g/L in 18 days, a 14-fold increase compared with the initial strain with glycolate dehydrogenase inactivated. This is also the highest glycolate titer biotechnologically produced from CO2 ever reported. Photosynthetic production of glycolate demonstrated the oxygenase activity of Form II Rubisco can be explored for production of chemicals from CO2.}, }
@article {pmid33963405, year = {2021}, author = {Skejo, J and Garg, SG and Gould, SB and Hendriksen, M and Tria, FDK and Bremer, N and Franjević, D and Blackstone, NW and Martin, WF}, title = {Evidence for a Syncytial Origin of Eukaryotes from Ancestral State Reconstruction.}, journal = {Genome biology and evolution}, volume = {13}, number = {7}, pages = {}, pmid = {33963405}, issn = {1759-6653}, mesh = {Archaea/genetics ; *Biological Evolution ; *Eukaryota/genetics ; Eukaryotic Cells ; Phylogeny ; Prokaryotic Cells ; }, abstract = {Modern accounts of eukaryogenesis entail an endosymbiotic encounter between an archaeal host and a proteobacterial endosymbiont, with subsequent evolution giving rise to a unicell possessing a single nucleus and mitochondria. The mononucleate state of the last eukaryotic common ancestor (LECA) is seldom, if ever, questioned, even though cells harboring multiple (syncytia, coenocytes, and polykaryons) are surprisingly common across eukaryotic supergroups. Here, we present a survey of multinucleated forms. Ancestral character state reconstruction for representatives of 106 eukaryotic taxa using 16 different possible roots and supergroup sister relationships, indicate that LECA, in addition to being mitochondriate, sexual, and meiotic, was multinucleate. LECA exhibited closed mitosis, which is the rule for modern syncytial forms, shedding light on the mechanics of its chromosome segregation. A simple mathematical model shows that within LECA's multinucleate cytosol, relationships among mitochondria and nuclei were neither one-to-one, nor one-to-many, but many-to-many, placing mitonuclear interactions and cytonuclear compatibility at the evolutionary base of eukaryotic cell origin. Within a syncytium, individual nuclei and individual mitochondria function as the initial lower-level evolutionary units of selection, as opposed to individual cells, during eukaryogenesis. Nuclei within a syncytium rescue each other's lethal mutations, thereby postponing selection for viable nuclei and cytonuclear compatibility to the generation of spores, buffering transitional bottlenecks at eukaryogenesis. The prokaryote-to-eukaryote transition is traditionally thought to have left no intermediates, yet if eukaryogenesis proceeded via a syncytial common ancestor, intermediate forms have persisted to the present throughout the eukaryotic tree as syncytia but have so far gone unrecognized.}, }
@article {pmid33962669, year = {2021}, author = {Manoj, RRS and Latrofa, MS and Epis, S and Otranto, D}, title = {Wolbachia: endosymbiont of onchocercid nematodes and their vectors.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {245}, pmid = {33962669}, issn = {1756-3305}, mesh = {Animals ; Arthropods/microbiology/physiology ; Host-Pathogen Interactions ; Nematoda/growth &amp; development/immunology/*microbiology ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: Wolbachia is an obligate intracellular maternally transmitted, gram-negative bacterium which forms a spectrum of endosymbiotic relationships from parasitism to obligatory mutualism in a wide range of arthropods and onchocercid nematodes, respectively. In arthropods Wolbachia produces reproductive manipulations such as male killing, feminization, parthenogenesis and cytoplasmic incompatibility for its propagation and provides an additional fitness benefit for the host to protect against pathogens, whilst in onchocercid nematodes, apart from the mutual metabolic dependence, this bacterium is involved in moulting, embryogenesis, growth and survival of the host.<br><br>METHODS: This review details the molecular data of Wolbachia and its effect on host biology, immunity, ecology and evolution, reproduction, endosymbiont-based treatment and control strategies exploited for filariasis. Relevant peer-reviewed scientic papers available in various authenticated scientific data bases were considered while writing the review.<br><br>CONCLUSIONS: The information presented provides an overview on Wolbachia biology and its use in the control and/or treatment of vectors, onchocercid nematodes and viral diseases of medical and veterinary importance. This offers the development of new approaches for the control of a variety of vector-borne diseases.}, }
@article {pmid33958407, year = {2021}, author = {Park, J and Lee, SH and Kim, JH}, title = {Complete Genome Sequence of the Endosymbiotic Bacterium "Candidatus Riesia pediculicola".}, journal = {Microbiology resource announcements}, volume = {10}, number = {18}, pages = {}, pmid = {33958407}, issn = {2576-098X}, abstract = {Human head and body lice host the obligate endosymbiotic bacterium "Candidatus Riesia pediculicola." In this announcement, we describe the complete genome sequence of a "Ca. Riesia pediculicola" strain isolated from the human head louse, Pediculus humanus subsp. capitis The inter- and intraspecific variations of endosymbiont genomes were investigated, and this strain was found to display high-level variations in its genome.}, }
@article {pmid33956519, year = {2021}, author = {Hensley, JR and Zambrano, ML and Williams-Newkirk, AJ and Dasch, GA}, title = {Detection of Rickettsia Species, and Coxiella-Like and Francisella-Like Endosymbionts in Amblyomma americanum and Amblyomma maculatum from a Shared Field Site in Georgia, United States of America.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {21}, number = {7}, pages = {509-516}, doi = {10.1089/vbz.2020.2683}, pmid = {33956519}, issn = {1557-7759}, mesh = {Amblyomma ; Animals ; Coxiella ; Dogs ; *Ehrlichia chaffeensis ; *Francisella/genetics ; Georgia/epidemiology ; *Ixodidae ; *Rickettsia/genetics ; }, abstract = {Two abundant species of aggressive ticks commonly feed on humans in Georgia: the Gulf Coast tick (Amblyomma maculatum) and the Lone Star tick (A. americanum). A. maculatum is the primary host of Rickettsia parkeri, "Candidatus Rickettsia andeanae," and a Francisella-like endosymbiont (AmacFLE), whereas A. americanum is the primary host for R. amblyommatis, Ehrlichia chaffeensis, E. ewingii, and a Coxiella-like endosymbiont (AamCLE). Horizontal transmission of R. parkeri from A. maculatum to A. americanum by co-feeding has been described, and R. amblyommatis has been found infrequently in A. maculatum ticks. We assessed the prevalence of these agents and whether exchange of tick-associated bacteria is common between A. maculatum and A. americanum collected from the same field site. Unengorged ticks were collected May-August 2014 in west-central Georgia from a 4.14 acre site by flagging and from humans and canines traversing that site. All DNA samples were screened with quantitative PCR assays for the bacteria found in both ticks, and the species of any Rickettsia detected was identified by species-specific TaqMan assays or sequencing of the rickettsial ompA gene. Only R. amblyommatis (15) and AamCLE (39) were detected in 40 A. americanum, while the 74 A. maculatum only contained R. parkeri (30), "Candidatus Rickettsia andeanae" (3), and AmacFLE (74). Neither tick species had either Ehrlichia species. Consequently, we obtained no evidence for the frequent exchange of these tick-borne agents in a natural setting despite high levels of carriage of each agent and the common observance of infestation of both ticks on both dogs and humans at this site. Based on these data, exchange of these Rickettsia, Coxiella, and Francisella agents between A. maculatum and A. americanum appears to be an infrequent event.}, }
@article {pmid33955029, year = {2021}, author = {Pilgrim, J and Siozios, S and Baylis, M and Venter, G and Garros, C and Hurst, GDD}, title = {Identifying potential candidate Culicoides spp. for the study of interactions with Candidatus Cardinium hertigii.}, journal = {Medical and veterinary entomology}, volume = {35}, number = {3}, pages = {501-506}, doi = {10.1111/mve.12517}, pmid = {33955029}, issn = {1365-2915}, support = {BB/M011186/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacteroidetes ; *Ceratopogonidae ; Mosquito Vectors ; Phylogeny ; *Wolbachia/genetics ; }, abstract = {Culicoides biting midges (Diptera: Ceratopogonidae) are vectors responsible for the transmission of several viruses of veterinary importance. Previous screens of Culicoides have described the presence of the endosymbiont Candidatus Cardinium hertigii (Bacteroidetes). However, any impacts of this microbe on vectorial capacity, akin to those conferred by Wolbachia in mosquitoes, are yet to be uncovered and await a suitable system to study Cardinium-midge interactions. To identify potential candidate species to investigate these interactions, accurate knowledge of the distribution of the endosymbiont within Culicoides populations is needed. We used conventional and nested PCR assays to screen Cardinium infection in 337 individuals of 25 Culicoides species from both Palearctic and Afrotropical regions. Infections were observed in several vector species including C. imicola and the Pulicaris complex (C. pulicaris, C. bysta, C. newsteadi and C. punctatus) with varying prevalence. Phylogenetic analysis based on the Gyrase B gene grouped all new isolates within 'group C' of the genus, a clade that has to date been exclusively described in Culicoides. Through a comparison of our results with previous screens, we suggest C. imicola and C. sonorensis represent good candidates for onward study of Cardinium-midge interactions.}, }
@article {pmid33947218, year = {2021}, author = {Hague, MTJ and Woods, HA and Cooper, BS}, title = {Pervasive effects of Wolbachia on host activity.}, journal = {Biology letters}, volume = {17}, number = {5}, pages = {20210052}, pmid = {33947218}, issn = {1744-957X}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila ; Locomotion ; Reproduction ; Symbiosis ; *Wolbachia ; }, abstract = {Heritable symbionts have diverse effects on the physiology, reproduction and fitness of their hosts. Maternally transmitted Wolbachia are one of the most common endosymbionts in nature, infecting about half of all insect species. We test the hypothesis that Wolbachia alter host behaviour by assessing the effects of 14 different Wolbachia strains on the locomotor activity of nine Drosophila host species. We find that Wolbachia alter the activity of six different host genotypes, including all hosts in our assay infected with wRi-like Wolbachia strains (wRi, wSuz and wAur), which have rapidly spread among Drosophila species in about the last 14 000 years. While Wolbachia effects on host activity were common, the direction of these effects varied unpredictably and sometimes depended on host sex. We hypothesize that the prominent effects of wRi-like Wolbachia may be explained by patterns of Wolbachia titre and localization within host somatic tissues, particularly in the central nervous system. Our findings support the view that Wolbachia have wide-ranging effects on host behaviour. The fitness consequences of these behavioural modifications are important for understanding the evolution of host-symbiont interactions, including how Wolbachia spread within host populations.}, }
@article {pmid33945798, year = {2021}, author = {Kaur, R and Shropshire, JD and Cross, KL and Leigh, B and Mansueto, AJ and Stewart, V and Bordenstein, SR and Bordenstein, SR}, title = {Living in the endosymbiotic world of Wolbachia: A centennial review.}, journal = {Cell host &amp; microbe}, volume = {29}, number = {6}, pages = {879-893}, pmid = {33945798}, issn = {1934-6069}, support = {F32 AI140694/AI/NIAID NIH HHS/United States ; R01 AI132581/AI/NIAID NIH HHS/United States ; R01 AI143725/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteriophages/physiology ; Biological Evolution ; Feminization ; *Host Microbial Interactions ; Host Specificity ; Humans ; Male ; Phenotype ; Phylogeny ; Preventive Medicine ; *Symbiosis ; Wolbachia/*cytology/*physiology/*virology ; }, abstract = {The most widespread intracellular bacteria in the animal kingdom are maternally inherited endosymbionts of the genus Wolbachia. Their prevalence in arthropods and nematodes worldwide and stunning arsenal of parasitic and mutualistic adaptations make these bacteria a biological archetype for basic studies of symbiosis and applied outcomes for curbing human and agricultural diseases. Here, we conduct a summative, centennial analysis of living in the Wolbachia world. We synthesize literature on Wolbachia's host range, phylogenetic diversity, genomics, cell biology, and applications to filarial, arboviral, and agricultural diseases. We also review the mobilome of Wolbachia including phage WO and its essentiality to hallmark reproductive phenotypes in arthropods. Finally, the Wolbachia system is an exemplar for discovery-based science education using biodiversity, biotechnology, and bioinformatics lessons. As we approach a century of Wolbachia research, the interdisciplinary science of this symbiosis stands as a model for consolidating and teaching the integrative rules of endosymbiotic life.}, }
@article {pmid33940005, year = {2021}, author = {Das, A and Roy, A and Mandal, A and Mondal, HA and Hess, D and Kundu, P and Das, S}, title = {Inhibition of Bemisia tabaci vectored, GroEL mediated transmission of tomato leaf curl New Delhi virus by garlic leaf lectin (Allium sativum leaf agglutinin).}, journal = {Virus research}, volume = {300}, number = {}, pages = {198443}, doi = {10.1016/j.virusres.2021.198443}, pmid = {33940005}, issn = {1872-7492}, mesh = {Agglutinins ; Animals ; *Aphids ; *Begomovirus/genetics ; Chromatography, Liquid ; *Garlic ; *Hemiptera ; Lectins ; Plant Diseases ; Tandem Mass Spectrometry ; }, abstract = {GroEL or symbionin synthesized by the endosymbionts of whitefly (Bemisia tabaci)/ aphids play a cardinal role in the persistent, circulative transmission of plant viruses by binding to viral coat protein/ read-through protein. Allium sativum leaf agglutinin (ASAL), a Galanthus nivalis agglutinin (GNA)- related mannose-binding lectin from garlic leaf has been reported as a potent controlling agent against hemipteran insects including whitefly and aphids. GroEL related chaperonin- symbionin was previously identified as a receptor of ASAL by the present group in the brush border membrane vesicle (BBMV) of mustard aphid. In the present study similar GroEL receptor of ASAL has been identified through LC-MS/MS in the BBMV of B. tabaci which serves as a vector for several plant viruses including tomato leaf curl New Delhi virus (ToLCNDV). Ligand blot analysis of ASAL-fed B. tabaci showed that when GroEL is pre-occupied by ASAL, it completely blocks its further binding to ToLCNDV coat protein (ToLCNDV-CP). Prior feeding of ASAL hindered the co-localization of ToLCNDV-CP and GroEL in the midgut of B. tabaci. Immunoprecipitation followed by western blot with ASAL-fed B. tabaci yielded similar result. Moreover, ASAL feeding inhibited viral transmission by B. tabaci. Together, these results confirmed that the interaction of ASAL with GroEL interferes with the binding of ToLCNDV-CP and inhibits further B. tabaci mediated viral transmission.}, }
@article {pmid33930291, year = {2021}, author = {Jia, N and Wang, J and Du, L and Shi, W and Zhao, F and Cao, WC}, title = {Reply to Evidence that microbes identified as tick-borne pathogens are nutritional endosymbionts.}, journal = {Cell}, volume = {184}, number = {9}, pages = {2261-2262}, doi = {10.1016/j.cell.2021.03.054}, pmid = {33930291}, issn = {1097-4172}, mesh = {Animals ; DNA, Bacterial ; *Rickettsia/genetics ; *Ticks ; }, }
@article {pmid33930290, year = {2021}, author = {Buysse, M and Duron, O}, title = {Evidence that microbes identified as tick-borne pathogens are nutritional endosymbionts.}, journal = {Cell}, volume = {184}, number = {9}, pages = {2259-2260}, doi = {10.1016/j.cell.2021.03.053}, pmid = {33930290}, issn = {1097-4172}, mesh = {Animals ; DNA, Bacterial ; *Rickettsia/genetics ; *Ticks ; }, }
@article {pmid33927399, year = {2021}, author = {Nand, A and Zhan, Y and Salazar, OR and Aranda, M and Voolstra, CR and Dekker, J}, title = {Genetic and spatial organization of the unusual chromosomes of the dinoflagellate Symbiodinium microadriaticum.}, journal = {Nature genetics}, volume = {53}, number = {5}, pages = {618-629}, pmid = {33927399}, issn = {1546-1718}, support = {R01 HG003143/HG/NHGRI NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Base Composition/genetics ; Benzimidazoles/pharmacology ; Chromosomes/*genetics ; Cross-Linking Reagents/chemistry ; Dinoflagellida/drug effects/*genetics ; Diterpenes/pharmacology ; Epoxy Compounds/pharmacology ; Gene Dosage ; Genome ; Phenanthrenes/pharmacology ; Repetitive Sequences, Nucleic Acid/genetics ; Telomere/genetics ; Transcription, Genetic/drug effects ; }, abstract = {Dinoflagellates are main primary producers in the oceans, the cause of algal blooms and endosymbionts of marine invertebrates. Much remains to be understood about their biology, including their peculiar crystalline chromosomes. We assembled 94 chromosome-scale scaffolds of the genome of the coral endosymbiont Symbiodinium microadriaticum and analyzed their organization. Genes are enriched towards the ends of chromosomes and are arranged in alternating unidirectional blocks. Some chromosomes are enriched for genes involved in specific biological processes. The chromosomes fold as linear rods and each is composed of a series of structural domains separated by boundaries. Domain boundaries are positioned at sites where transcription of two gene blocks converges and disappear when cells are treated with chemicals that block transcription, indicating correlations between gene orientation, transcription and chromosome folding. The description of the genetic and spatial organization of the S. microadriaticum genome provides a foundation for deeper exploration of the extraordinary biology of dinoflagellates and their chromosomes.}, }
@article {pmid33927044, year = {2021}, author = {Park, J and Xi, H and Park, J}, title = {Complete Genome Sequence of a Blochmannia Endosymbiont of Colobopsis nipponica.}, journal = {Microbiology resource announcements}, volume = {10}, number = {17}, pages = {}, pmid = {33927044}, issn = {2576-098X}, abstract = {Blochmannia endosymbionts (Gammaproteobacteria) live in bacteriocytes, which are specialized cells found in the genus Camponotus and its neighbor genera. In this announcement, we describe the complete genome sequence of the Blochmannia endosymbiont of Colobopsis nipponica, which originated from a colony collected in the Republic of Korea.}, }
@article {pmid33925663, year = {2021}, author = {Cantanhêde, LM and Mata-Somarribas, C and Chourabi, K and Pereira da Silva, G and Dias das Chagas, B and de Oliveira R Pereira, L and Côrtes Boité, M and Cupolillo, E}, title = {The Maze Pathway of Coevolution: A Critical Review over the Leishmania and Its Endosymbiotic History.}, journal = {Genes}, volume = {12}, number = {5}, pages = {}, pmid = {33925663}, issn = {2073-4425}, mesh = {Animals ; Biological Evolution ; Humans ; Leishmania/*genetics ; Leishmaniasis/parasitology ; Phylogeny ; RNA Viruses/genetics ; Symbiosis/*genetics ; }, abstract = {The description of the genus Leishmania as the causative agent of leishmaniasis occurred in the modern age. However, evolutionary studies suggest that the origin of Leishmania can be traced back to the Mesozoic era. Subsequently, during its evolutionary process, it achieved worldwide dispersion predating the breakup of the Gondwana supercontinent. It is assumed that this parasite evolved from monoxenic Trypanosomatidae. Phylogenetic studies locate dixenous Leishmania in a well-supported clade, in the recently named subfamily Leishmaniinae, which also includes monoxenous trypanosomatids. Virus-like particles have been reported in many species of this family. To date, several Leishmania species have been reported to be infected by Leishmania RNA virus (LRV) and Leishbunyavirus (LBV). Since the first descriptions of LRVs decades ago, differences in their genomic structures have been highlighted, leading to the designation of LRV1 in L. (Viannia) species and LRV2 in L. (Leishmania) species. There are strong indications that viruses that infect Leishmania spp. have the ability to enhance parasitic survival in humans as well as in experimental infections, through highly complex and specialized mechanisms. Phylogenetic analyses of these viruses have shown that their genomic differences correlate with the parasite species infected, suggesting a coevolutionary process. Herein, we will explore what has been described in the literature regarding the relationship between Leishmania and endosymbiotic Leishmania viruses and what is known about this association that could contribute to discussions about the worldwide dispersion of Leishmania.}, }
@article {pmid33919688, year = {2021}, author = {He, W and Pan, L and Han, W and Wang, X}, title = {Isothiazolinones as Novel Candidate Insecticides for the Control of Hemipteran Insects.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {10}, number = {4}, pages = {}, pmid = {33919688}, issn = {2079-6382}, abstract = {Hemipteran insects, such as whiteflies, aphids and planthoppers, resemble one of the most important pest groups threating food security. While many insecticides have been used to control these pests, many issues such as insecticide resistance have been found, highlighting the urgent need to develop novel insecticides. Here, we first observed that a commercial tetramycin solution was highly effective in killing whitefly. The major bioactive constituents were identified to be isothiazolinones, a group of biocides. We then tested the toxicity of several isothiazolinones to five hemipteran insects. The results show that Kathon, a widely used biocide against microorganisms, and its two constituents, chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT), can cause considerable levels of mortality to whiteflies and aphids when applied at concentrations close to, or lower than, the upper limit of these chemicals permitted in cosmetic products. The results also indicate that two other isothiazolinones, benzisothiazolinone (BIT) and octylisothiazolinone (OIT) can cause considerable levels of mortality to whitefly and aphids but are less toxic than Kathon. Further, we show that Kathon marginally affects whitefly endosymbionts, suggesting its insecticidal activity is independent of its biocidal activity. These results suggest that some isothiazolinones are promising candidates for the development of a new class of insecticides for the control of hemipteran pests.}, }
@article {pmid33914801, year = {2021}, author = {Masson, F and Rommelaere, S and Marra, A and Schüpfer, F and Lemaitre, B}, title = {Dual proteomics of Drosophila melanogaster hemolymph infected with the heritable endosymbiont Spiroplasma poulsonii.}, journal = {PloS one}, volume = {16}, number = {4}, pages = {e0250524}, pmid = {33914801}, issn = {1932-6203}, mesh = {Animals ; Bacterial Proteins/genetics ; Drosophila melanogaster/*genetics/immunology/microbiology ; Female ; Hemolymph/microbiology ; Oogenesis/genetics ; Proteome/*genetics ; *Proteomics ; Signal Transduction/genetics/immunology ; Spiroplasma/*genetics/pathogenicity ; Symbiosis/genetics/immunology ; }, abstract = {Insects are frequently infected with heritable bacterial endosymbionts. Endosymbionts have a dramatic impact on their host physiology and evolution. Their tissue distribution is variable with some species being housed intracellularly, some extracellularly and some having a mixed lifestyle. The impact of extracellular endosymbionts on the biofluids they colonize (e.g. insect hemolymph) is however difficult to appreciate because biofluid composition can depend on the contribution of numerous tissues. Here we investigate Drosophila hemolymph proteome changes in response to the infection with the endosymbiont Spiroplasma poulsonii. S. poulsonii inhabits the fly hemolymph and gets vertically transmitted over generations by hijacking the oogenesis in females. Using dual proteomics on infected hemolymph, we uncovered a weak, chronic activation of the Toll immune pathway by S. poulsonii that was previously undetected by transcriptomics-based approaches. Using Drosophila genetics, we also identified candidate proteins putatively involved in controlling S. poulsonii growth. Last, we also provide a deep proteome of S. poulsonii, which, in combination with previously published transcriptomics data, improves our understanding of the post-transcriptional regulations operating in this bacterium.}, }
@article {pmid33914388, year = {2021}, author = {Wong, KH and Goodbody-Gringley, G and de Putron, SJ and Becker, DM and Chequer, A and Putnam, HM}, title = {Brooded coral offspring physiology depends on the combined effects of parental press and pulse thermal history.}, journal = {Global change biology}, volume = {27}, number = {13}, pages = {3179-3195}, doi = {10.1111/gcb.15629}, pmid = {33914388}, issn = {1365-2486}, mesh = {Acclimatization ; Animals ; *Anthozoa ; Chlorophyll A ; Coral Reefs ; Hot Temperature ; }, abstract = {Reef-building corals respond to the temporal integration of both pulse events (i.e., heat waves) and press thermal history (i.e., local environment) via physiological changes, with ecological consequences. We used a "press-pulse-press" experimental framework to expose the brooding coral Porites astreoides to various thermal histories to understand the physiological response of temporal dynamics within and across generations. We collected adult colonies from two reefs (outer Rim reef and inner Patch reef) in Bermuda with naturally contrasting thermal regimes as our initial "press" scenario, followed by a 21-day ex situ "pulse" thermal stress of 30.4°C during larval brooding, and a "press" year-long adult reciprocal transplant between the original sites. Higher endosymbiont density and holobiont protein was found in corals originating from the lower thermal variability site (Rim) compared to the higher thermal variability site (Patch). The thermal pulse event drove significant declines in photosynthesis, endosymbiont density, and chlorophyll a, with bleaching phenotype convergence for adults from both histories. Following the reciprocal transplant, photosynthesis was higher in previously heated corals, indicating recovery from the thermal pulse. The effect of origin (initial press) modulated the response to transplant site for endosymbiont density and chlorophyll a, suggesting contrasting acclimation strategies. Higher respiration and photosynthetic rates were found in corals originating from the Rim site, indicating greater energy available for reproduction, supported by larger larvae released from Rim corals post-transplantation. Notably, parental exposure to the pulse thermal event resulted in increased offspring plasticity when parents were transplanted to foreign sites, highlighting the legacy of the pulse event and the importance of the environment during recovery in contributing to cross-generational or developmental plasticity. Together, these findings provide novel insight into the role of historical disturbance events in driving differential outcomes within and across generations, which is of critical importance in forecasting reef futures.}, }
@article {pmid33912718, year = {2021}, author = {Shemshadian, A and Vatandoost, H and Oshaghi, MA and Abai, MR and Djadid, ND and Karimian, F}, title = {Relationship between Wolbachia infection in Culex quinquefasciatus and its resistance to insecticide.}, journal = {Heliyon}, volume = {7}, number = {4}, pages = {e06749}, pmid = {33912718}, issn = {2405-8440}, abstract = {Many studies have been done on the various factors affecting resistance to insecticides. The relationship between Wolbachia bacteria and resistance to insecticides is one of the factors that has attracted a lot of attentions. Wolbachia are obligatory intracellular endosymbionts that naturally occur in a wide range of arthropods and nematodes, including the mosquito Culex quinquefasciatus. Initially, the presence of bacteria was proved by molecular assays. Then the resistance level of this species was evaluated in adults against DDT 4.0% and deltamethrin 0.05% using the standard WHO guideline. After elimination of Wolbachia by tetracycline and its proof by molecular assays, the susceptibility tests were conducted again on uninfected line. Finally, the two lines were compared in terms of responding to insecticides. The findings indicated that there is no significant correlation between susceptibility of two lines in response to DDT 4.0% while they represented a significant correlation for deltamethrin (P =0.00). We propose that Wolbachia bacteria increase the susceptibility to deltamethrin but they show neutral effect on DDT susceptibility in Cx. quinquefasciatus. However, more studies on other vectors and insecticides still need to be done.}, }
@article {pmid33901257, year = {2021}, author = {Nichols, HL and Goldstein, EB and Saleh Ziabari, O and Parker, BJ}, title = {Intraspecific variation in immune gene expression and heritable symbiont density.}, journal = {PLoS pathogens}, volume = {17}, number = {4}, pages = {e1009552}, pmid = {33901257}, issn = {1553-7374}, mesh = {Animals ; Aphids/classification/genetics/immunology/*microbiology ; Bacterial Load/*genetics/physiology ; Enterobacteriaceae/classification/cytology/genetics/*immunology ; Gene Expression ; Gene Expression Regulation, Bacterial ; Genes, Insect/genetics ; Genetic Variation/physiology ; Host Microbial Interactions/genetics/immunology ; Immunity, Innate/*genetics ; Species Specificity ; *Symbiosis/genetics/immunology ; }, abstract = {Host genetic variation plays an important role in the structure and function of heritable microbial communities. Recent studies have shown that insects use immune mechanisms to regulate heritable symbionts. Here we test the hypothesis that variation in symbiont density among hosts is linked to intraspecific differences in the immune response to harboring symbionts. We show that pea aphids (Acyrthosiphon pisum) harboring the bacterial endosymbiont Regiella insecticola (but not all other species of symbionts) downregulate expression of key immune genes. We then functionally link immune expression with symbiont density using RNAi. The pea aphid species complex is comprised of multiple reproductively-isolated host plant-adapted populations. These 'biotypes' have distinct patterns of symbiont infections: for example, aphids from the Trifolium biotype are strongly associated with Regiella. Using RNAseq, we compare patterns of gene expression in response to Regiella in aphid genotypes from multiple biotypes, and we show that Trifolium aphids experience no downregulation of immune gene expression while hosting Regiella and harbor symbionts at lower densities. Using F1 hybrids between two biotypes, we find that symbiont density and immune gene expression are both intermediate in hybrids. We propose that in this system, Regiella symbionts are suppressing aphid immune mechanisms to increase their density, but that some hosts have adapted to prevent immune suppression in order to control symbiont numbers. This work therefore suggests that antagonistic coevolution can play a role in host-microbe interactions even when symbionts are transmitted vertically and provide a clear benefit to their hosts. The specific immune mechanisms that we find are downregulated in the presence of Regiella have been previously shown to combat pathogens in aphids, and thus this work also highlights the immune system's complex dual role in interacting with both beneficial and harmful microbes.}, }
@article {pmid33895462, year = {2021}, author = {Zurita, A and Benkacimi, L and El Karkouri, K and Cutillas, C and Parola, P and Laroche, M}, title = {New records of bacteria in different species of fleas from France and Spain.}, journal = {Comparative immunology, microbiology and infectious diseases}, volume = {76}, number = {}, pages = {101648}, doi = {10.1016/j.cimid.2021.101648}, pmid = {33895462}, issn = {1878-1667}, mesh = {Animals ; *Bacteria/classification/genetics ; *Ctenocephalides/microbiology ; Europe ; *Flea Infestations/epidemiology/veterinary ; France ; *Siphonaptera/microbiology ; Spain/epidemiology ; }, abstract = {In this study, we assessed the presence of vector-borne microorganisms in different species of fleas collected from different hosts in diverse areas of South-Western Europe by molecular methods. A total of 319 fleas belonging to eight different species was tested for the presence of eight microorganisms. Wolbachia spp. endosymbionts were detected in Ctenocephalides felis, Pulex irritans, Archaeopsylla erinacei and Ctenophthalmus baeticus boisseauorum specimens. Rickettsia felis, an emerging pathogen, was detected in C. felis, A. erinacei and Ct. b. boisseauorum. Rickettsia typhi, the agent of murine typhus was detected for the first time in A. erinacei and Mycobacterium spp. were detected for the first time in fleas (C. felis, P. irritans and A. erinacei). Lastly, five different species of Bartonella were detected in fleas' DNA in this study, including a possible new bacterium belonging to this genus. With this study, we updated the knowledge of the flea-borne bacteria present in the South-West of Europe reinforcing the idea about the necessity to expand and increase the current knowledge on flea-borne pathogens.}, }
@article {pmid33892498, year = {2021}, author = {Knopp, M and Stockhorst, S and van der Giezen, M and Garg, SG and Gould, SB}, title = {The Asgard Archaeal-Unique Contribution to Protein Families of the Eukaryotic Common Ancestor Was 0.3.}, journal = {Genome biology and evolution}, volume = {13}, number = {6}, pages = {}, pmid = {33892498}, issn = {1759-6653}, mesh = {Archaea/*genetics ; Bacteria/*genetics ; Eukaryota/*genetics ; *Multigene Family ; }, abstract = {The identification of the asgard archaea has fueled speculations regarding the nature of the archaeal host in eukaryogenesis and its level of complexity prior to endosymbiosis. Here, we analyzed the coding capacity of 150 eukaryotes, 1,000 bacteria, and 226 archaea, including the only cultured member of the asgard archaea. Clustering methods that consistently recover endosymbiotic contributions to eukaryotic genomes recover an asgard archaeal-unique contribution of a mere 0.3% to protein families present in the last eukaryotic common ancestor, while simultaneously suggesting that this group's diversity rivals that of all other archaea combined. The number of homologs shared exclusively between asgard archaea and eukaryotes is only 27 on average. This tiny asgard archaeal-unique contribution to the root of eukaryotic protein families questions claims that archaea evolved complexity prior to eukaryogenesis. Genomic and cellular complexity remains a eukaryote-specific feature and is best understood as the archaeal host's solution to housing an endosymbiont.}, }
@article {pmid33882628, year = {2021}, author = {Wolfe, TM and Bruzzese, DJ and Klasson, L and Corretto, E and Lečić, S and Stauffer, C and Feder, JL and Schuler, H}, title = {Comparative genome sequencing reveals insights into the dynamics of Wolbachia in native and invasive cherry fruit flies.}, journal = {Molecular ecology}, volume = {30}, number = {23}, pages = {6259-6272}, pmid = {33882628}, issn = {1365-294X}, mesh = {Animals ; Drosophila ; Multilocus Sequence Typing ; Symbiosis/genetics ; *Tephritidae/genetics ; *Wolbachia/genetics ; }, abstract = {Wolbachia is a maternally inherited obligate endosymbiont that can induce a wide spectrum of effects in its host, ranging from mutualism to reproductive parasitism. At the genomic level, recombination within and between strains, transposable elements, and horizontal transfer of strains between host species make Wolbachia an evolutionarily dynamic bacterial system. The invasive cherry fruit fly Rhagoletis cingulata arrived in Europe from North America ~40 years ago, where it now co-occurs with the native cherry pest R. cerasi. This shared distribution has been proposed to have led to the horizontal transfer of different Wolbachia strains between the two species. To better understand transmission dynamics, we performed a comparative genome study of the strain wCin2 in its native United States and invasive European populations of R. cingulata with wCer2 in European R. cerasi. Previous multilocus sequence genotyping (MLST) of six genes implied that the source of wCer2 in R. cerasi was wCin2 from R. cingulata. However, we report genomic evidence discounting the recent horizontal transfer hypothesis for the origin of wCer2. Despite near identical sequences for the MLST markers, substantial sequence differences for other loci were found between wCer2 and wCin2, as well as structural rearrangements, and differences in prophage, repetitive element, gene content, and cytoplasmic incompatibility inducing genes. Our study highlights the need for whole-genome sequencing rather than relying on MLST markers for resolving Wolbachia strains and assessing their evolutionary dynamics.}, }
@article {pmid33882275, year = {2021}, author = {Liu, XC and Li, ZX}, title = {Transmission of the wMel Wolbachia strain is modulated by its titre and by immune genes in Drosophila melanogaster (Wolbachia density and transmission).}, journal = {Journal of invertebrate pathology}, volume = {181}, number = {}, pages = {107591}, doi = {10.1016/j.jip.2021.107591}, pmid = {33882275}, issn = {1096-0805}, mesh = {Animals ; Drosophila melanogaster/genetics/*immunology ; Wolbachia/*physiology ; }, abstract = {Wolbachia are common intracellular endosymbionts of arthropods, but the interactions between Wolbachia and arthropods are only partially understood. The fruit fly Drosophila melanogaster is a model insect for understanding Wolbachia-host interactions. Here the native wMel strain of D. melanogaster was isolated and then different initial titres of wMel were artificially transferred back into antibiotics-treated fruit flies. Our purpose was to examine the interactions between the injected wMel in a density gradient and the recipient host during trans-generational transmission. The results showed that the trans-generational transmission rates of wMel and titres of wMel exhibited a fluctuating trend over nine generations, and the titres of wMel displayed a similar fluctuating trans-generational trend. There was a significant positive correlation between the transmission rate and the titre of wMel. Reciprocal crossings between wMel-transinfected and uninfected fruit flies revealed that wMel could induce cytoplasmic incompatibility (CI) at different initial titres, but the intensity of CI was not significantly correlated with the initial titre of wMel. Quantitative PCR analysis showed that the immune genes Drsl5 and Spn38F displayed a significant transcriptional response to wMel transfection, with an obvious negative correlation with the titre of wMel at the 3rd and 4th generations. Furthermore, RNA interference-mediated knockdown of Drsl5 and Spn38F elicited a drastic increase in the titre of wMel. In combination, our study suggests that the trans-generational transmission of wMel is modulated by its density, and the immune genes are involved in the regulation of Wolbachia density.}, }
@article {pmid33876478, year = {2021}, author = {Smith, AH and O'Connor, MP and Deal, B and Kotzer, C and Lee, A and Wagner, B and Joffe, J and Woloszynek, S and Oliver, KM and Russell, JA}, title = {Does getting defensive get you anywhere?-Seasonal balancing selection, temperature, and parasitoids shape real-world, protective endosymbiont dynamics in the pea aphid.}, journal = {Molecular ecology}, volume = {30}, number = {10}, pages = {2449-2472}, doi = {10.1111/mec.15906}, pmid = {33876478}, issn = {1365-294X}, mesh = {Animals ; *Aphids/genetics ; Genotype ; Peas ; Seasons ; Symbiosis ; Temperature ; *Wasps/genetics ; }, abstract = {Facultative, heritable endosymbionts are found at intermediate prevalence within most insect species, playing frequent roles in their hosts' defence against environmental pressures. Focusing on Hamiltonella defensa, a common bacterial endosymbiont of aphids, we tested the hypothesis that such pressures impose seasonal balancing selection, shaping a widespread infection polymorphism. In our studied pea aphid (Acyrthosiphon pisum) population, Hamiltonella frequencies ranged from 23.2% to 68.1% across a six-month longitudinal survey. Rapid spikes and declines were often consistent across fields, and we estimated that selection coefficients for Hamiltonella-infected aphids changed sign within this field season. Prior laboratory research suggested antiparasitoid defence as the major Hamiltonella benefit, and costs under parasitoid absence. While a prior field study suggested these forces can sometimes act as counter-weights in a regime of seasonal balancing selection, our present survey showed no significant relationship between parasitoid wasps and Hamiltonella prevalence. Field cage experiments provided some explanation: parasitoids drove modest ~10% boosts to Hamiltonella frequencies that would be hard to detect under less controlled conditions. They also showed that Hamiltonella was not always costly under parasitoid exclusion, contradicting another prediction. Instead, our longitudinal survey - and two overwintering studies - showed temperature to be the strongest predictor of Hamiltonella prevalence. Matching some prior lab discoveries, this suggested that thermally sensitive costs and benefits, unrelated to parasitism, can shape Hamiltonella dynamics. These results add to a growing body of evidence for rapid, seasonal adaptation in multivoltine organisms, suggesting that such adaptation can be mediated through the diverse impacts of heritable bacterial endosymbionts.}, }
@article {pmid33875732, year = {2021}, author = {Kwarteng, A and Asiedu, E and Sylverken, A and Larbi, A and Mubarik, Y and Apprey, C}, title = {In silico drug repurposing for filarial infection predicts nilotinib and paritaprevir as potential inhibitors of the Wolbachia 5'-aminolevulinic acid synthase.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {8455}, pmid = {33875732}, issn = {2045-2322}, mesh = {5-Aminolevulinate Synthetase/*antagonists &amp; inhibitors ; Amino Acid Sequence ; *Computer Simulation ; Cyclopropanes/*pharmacology ; Drug Repositioning/*methods ; Enzyme Inhibitors/*pharmacology ; Humans ; Lactams, Macrocyclic/*pharmacology ; Proline/*analogs &amp; derivatives/pharmacology ; Pyrimidines/*pharmacology ; Sequence Homology ; Sulfonamides/*pharmacology ; Wolbachia/*drug effects/enzymology/growth &amp; development ; }, abstract = {Filarial infections affect millions of individuals and are responsible for some notorious disabilities. Current treatment options involve repeated mass drug administrations, which have been met with several challenges despite some successes. Administration of doxycycline, an anti-Wolbachia agent, has shown clinical effectiveness but has several limitations, including long treatment durations and contraindications. We describe the use of an in silico drug repurposing approach to screening a library of over 3200 FDA-approved medications against the filarial endosymbiont, Wolbachia. We target the enzyme which catalyzes the first step of heme biosynthesis in the Wolbachia. This presents an opportunity to inhibit heme synthesis, which leads to depriving the filarial worm of heme, resulting in a subsequent macrofilaricidal effect. High throughput virtual screening, molecular docking and molecular simulations with binding energy calculations led to the identification of paritaprevir and nilotinib as potential anti-Wolbachia agents. Having higher binding affinities to the catalytic pocket than the natural substrate, these drugs have the structural potential to bind and engage active site residues of the wolbachia 5'-Aminolevulinic Acid Synthase. We hereby propose paritaprevir and nilotinib for experimental validations as anti-Wolbachia agents.}, }
@article {pmid33868697, year = {2021}, author = {Jeffries, CL and Cansado-Utrilla, C and Beavogui, AH and Stica, C and Lama, EK and Kristan, M and Irish, SR and Walker, T}, title = {Evidence for natural hybridization and novel Wolbachia strain superinfections in the Anopheles gambiae complex from Guinea.}, journal = {Royal Society open science}, volume = {8}, number = {4}, pages = {202032}, pmid = {33868697}, issn = {2054-5703}, abstract = {Wolbachia, a widespread bacterium which can influence mosquito-borne pathogen transmission, has recently been detected within Anopheles (An.) species that are malaria vectors in Sub-Saharan Africa. Although studies have reported Wolbachia strains in the An. gambiae complex, apparent low density and prevalence rates require confirmation. In this study, wild Anopheles mosquitoes collected from two regions of Guinea were investigated. In contrast with previous studies, RNA was extracted from adult females (n = 516) to increase the chances for the detection of actively expressed Wolbachia genes, determine Wolbachia prevalence rates and estimate relative strain densities. Molecular confirmation of mosquito species and Wolbachia multilocus sequence typing (MLST) were carried out to analyse phylogenetic relationships of mosquito hosts and newly discovered Wolbachia strains. Strains were detected in An. melas (prevalence rate of 11.6%-16/138) and hybrids between An. melas and An. gambiae sensu stricto (prevalence rate of 40.0%-6/15) from Senguelen in the Maferinyah region. Furthermore, a novel high-density strain, termed wAnsX, was found in an unclassified Anopheles species. The discovery of novel Wolbachia strains (particularly in members, and hybrids, of the An. gambiae complex) provides further candidate strains that could be used for future Wolbachia-based malaria biocontrol strategies.}, }
@article {pmid33860546, year = {2021}, author = {Brandeis, M}, title = {Were eukaryotes made by sex?: Sex might have been vital for merging endosymbiont and host genomes giving rise to eukaryotes.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {43}, number = {6}, pages = {e2000256}, doi = {10.1002/bies.202000256}, pmid = {33860546}, issn = {1521-1878}, mesh = {Archaea/genetics ; *Biological Evolution ; *Eukaryota/genetics ; Eukaryotic Cells ; Phylogeny ; Symbiosis/genetics ; }, abstract = {I hypothesize that the appearance of sex facilitated the merging of the endosymbiont and host genomes during early eukaryote evolution. Eukaryotes were formed by symbiosis between a bacterium that entered an archaeon, eventually giving rise to mitochondria. This entry was followed by the gradual transfer of most bacterial endosymbiont genes into the archaeal host genome. I argue that the merging of the mitochondrial genes into the host genome was vital for the evolution of genuine eukaryotes. At the time this process commenced it was unprecedented and required a novel mechanism. I suggest that this mechanism was meiotic sex, and that its appearance might have been THE crucial step that enabled the evolution of proper eukaryotes from early endosymbiont containing proto-eukaryotes. Sex might continue to be essential today for keeping genome insertions in check. Also see the video abstract here: https://youtu.be/aVMvWMpomac.}, }
@article {pmid33857748, year = {2021}, author = {Bermúdez, S and Martínez-Mandiche, J and Domínguez, L and Gonzalez, C and Chavarria, O and Moreno, A and Góndola, J and Correa, N and Rodríguez, I and Castillo, B and Smith, D and Martínez, AA}, title = {Diversity of Rickettsia in ticks collected from wild animals in Panama.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {4}, pages = {101723}, doi = {10.1016/j.ttbdis.2021.101723}, pmid = {33857748}, issn = {1877-9603}, mesh = {Amblyomma/*microbiology/physiology ; Animals ; *Iguanas ; Ixodes/*microbiology/physiology ; *Mammals ; *Microbiota ; Panama ; Rickettsia/classification/*isolation &amp; purification ; Tick Infestations/parasitology/*veterinary ; }, abstract = {This paper presents new data about Rickettsia species detected in ticks collected from wild animals, using 16S rRNA, gltA and ompA. Rickettsia DNA was found in 66 of 101 ticks. Using EZ BioCloud libraries were produced reads that identified Rickettsia aeschlimannii, and Illumina BaseSpace produced reads of Rickettsia rickettsii group, Rickettsia bellii group, and unclassified Rickettsia. Using gltA and ompA gene-specific primers, R. aeschlimannii could not be confirmed, but detection of Rickettsia amblyommatis was achieved in Amblyomma auricularium, Amblyomma geayi, Amblyomma mixtum, and Amblyomma pacae; R. bellii from Amblyomma dissimile, "Candidatus Rickettsia colombianensi" from A. dissimile, Rickettsia spp. closely related to R. raoultii from A. geayi, Rickettsia tamurae from A. dissimile, and Rickettsia endosymbionts of Ixodes from Ixodes affinis. There were no databases available specifically for 16S rRNA of Neotropical Rickettsia, highlighting the need to use species primers over only 16S rRNA primers to achieve more accurate interpretations and identifications. These findings increase the number of Rickettsia species detected in Panama and highlight the need to establish isolates to further characterize the nature of Rickettsia in the area.}, }
@article {pmid33857432, year = {2021}, author = {Walker, T and Quek, S and Jeffries, CL and Bandibabone, J and Dhokiya, V and Bamou, R and Kristan, M and Messenger, LA and Gidley, A and Hornett, EA and Anderson, ER and Cansado-Utrilla, C and Hegde, S and Bantuzeko, C and Stevenson, JC and Lobo, NF and Wagstaff, SC and Nkondjio, CA and Irish, SR and Heinz, E and Hughes, GL}, title = {Stable high-density and maternally inherited Wolbachia infections in Anopheles moucheti and Anopheles demeilloni mosquitoes.}, journal = {Current biology : CB}, volume = {31}, number = {11}, pages = {2310-2320.e5}, pmid = {33857432}, issn = {1879-0445}, support = {/WT_/Wellcome Trust/United Kingdom ; R21 AI124452/AI/NIAID NIH HHS/United States ; R21 AI129507/AI/NIAID NIH HHS/United States ; R21 AI138074/AI/NIAID NIH HHS/United States ; BB/T001240/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; V011278/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; *Anopheles/genetics ; In Situ Hybridization, Fluorescence ; *Malaria ; Maternal Inheritance ; Mosquito Vectors ; *Wolbachia/genetics ; }, abstract = {Wolbachia, a widespread bacterium that can reduce pathogen transmission in mosquitoes, has recently been reported to be present in Anopheles (An.) species. In wild populations of the An. gambiae complex, the primary vectors of Plasmodium malaria in Sub-Saharan Africa, Wolbachia DNA sequences at low density and infection frequencies have been detected. As the majority of studies have used highly sensitive nested PCR as the only method of detection, more robust evidence is required to determine whether Wolbachia strains are established as endosymbionts in Anopheles species. Here, we describe high-density Wolbachia infections in geographically diverse populations of An. moucheti and An. demeilloni. Fluorescent in situ hybridization localized a heavy infection in the ovaries of An. moucheti, and maternal transmission was observed. Genome sequencing of both Wolbachia strains obtained genome depths and coverages comparable to those of other known infections. Notably, homologs of cytoplasmic incompatibility factor (cif) genes were present, indicating that these strains possess the capacity to induce the cytoplasmic incompatibility phenotype, which allows Wolbachia to spread through host populations. These strains should be further investigated as candidates for use in Wolbachia biocontrol strategies in Anopheles aiming to reduce the transmission of malaria.}, }
@article {pmid33857428, year = {2021}, author = {Moore, WM and Chan, C and Ishikawa, T and Rennie, EA and Wipf, HM and Benites, V and Kawai-Yamada, M and Mortimer, JC and Scheller, HV}, title = {Reprogramming sphingolipid glycosylation is required for endosymbiont persistence in Medicago truncatula.}, journal = {Current biology : CB}, volume = {31}, number = {11}, pages = {2374-2385.e4}, doi = {10.1016/j.cub.2021.03.067}, pmid = {33857428}, issn = {1879-0445}, mesh = {Gene Expression Regulation, Plant ; Glucosamine ; Glycosylation ; Inositol ; *Medicago truncatula/genetics/metabolism ; *Mycorrhizae/metabolism ; Plant Proteins/genetics/metabolism ; Plant Roots/metabolism ; Sphingolipids ; Symbiosis ; }, abstract = {Plant endosymbiosis relies on the development of specialized membranes that encapsulate the endosymbiont and facilitate nutrient exchange. However, the identity and function of lipids within these membrane interfaces is largely unknown. Here, we identify GLUCOSAMINE INOSITOL PHOSPHORYLCERAMIDE TRANSFERASE1 (GINT1) as a sphingolipid glycosyltransferase highly expressed in Medicago truncatula root nodules and roots colonized by arbuscular mycorrhizal (AM) fungi and further demonstrate that this enzyme functions in the synthesis of N-acetyl-glucosamine-decorated glycosyl inositol phosphoryl ceramides (GIPCs) in planta. MtGINT1 expression was developmentally regulated in symbiotic tissues associated with the development of symbiosome and periarbuscular membranes. RNAi silencing of MtGINT1 did not affect overall root growth but strongly impaired nodulation and AM symbiosis, resulting in the senescence of symbiosomes and arbuscules. Our results indicate that, although M. truncatula root sphingolipidome predominantly consists of hexose-decorated GIPCs, local reprogramming of GIPC glycosylation by MtGINT1 is required for the persistence of endosymbionts within the plant cell.}, }
@article {pmid33855055, year = {2021}, author = {Palomar, AM and Veiga, J and Portillo, A and Santibáñez, S and Václav, R and Santibáñez, P and Oteo, JA and Valera, F}, title = {Novel Genotypes of Nidicolous Argas Ticks and Their Associated Microorganisms From Spain.}, journal = {Frontiers in veterinary science}, volume = {8}, number = {}, pages = {637837}, pmid = {33855055}, issn = {2297-1769}, abstract = {The knowledge of the distribution, richness and epidemiological importance of soft ticks of the genus Argas is incomplete. In Spain, five Argas species have been recorded, including three ornitophilic nidicolous ticks, but their associated microorganisms remain unknown. This study aimed to investigate ticks from bird nests and their microorganisms. Ticks were collected extensively from natural cavities and nest-boxes used by European rollers (Coracias garrulus) and little owls (Athene noctua) in Southeastern and Central Spain. Ticks were morphologically and genetically identified and corresponding DNA/RNA tick extracts were analyzed [individually (n = 150) or pooled (n = 43)] using specific PCR assays for bacteria (Anaplasmataceae, Bartonella, Borrelia, Coxiella/Rickettsiella, and Rickettsia spp.), viruses (Flaviviruses, Orthonairoviruses, and Phenuiviruses), and protozoa (Babesia/Theileria spp.). Six Argas genotypes were identified, of which only those of Argas reflexus (n = 8) were identified to the species level. Two other genotypes were closely related to each other and to Argas vulgaris (n = 83) and Argas polonicus (n = 33), respectively. These two species have not been previously reported from Western Europe. Two additional genotypes (n = 4) clustered with Argas persicus, previously reported in Spain. The remaining genotype (n = 22) showed low sequence identity with any Argas species, being most similar to the African Argas africolumbae. The microbiological screening revealed infection with a rickettsial strain belonging to Rickettsia fournieri and Candidatus Rickettsia vini group in 74.7% of ticks, mainly comprising ticks genetically related to A. vulgaris and A. polonicus. Other tick endosymbionts belonging to Coxiella, Francisella and Rickettsiella species were detected in ten, one and one tick pools, respectively. In addition, one Babesia genotype, closely related to avian Babesia species, was found in one tick pool. Lastly, Anaplasmataceae, Bartonella, Borrelia, and viruses were not detected. In conclusion, five novel Argas genotypes and their associated microorganisms with unproven pathogenicity are reported for Spain. The re-use of nests between and within years by different bird species appears to be ideal for the transmission of tick-borne microorganisms in cavity-nesting birds of semiarid areas. Further work should be performed to clarify the taxonomy and the potential role of soft Argas ticks and their microorganisms in the epidemiology of zoonoses.}, }
@article {pmid33854192, year = {2021}, author = {Maire, J and Girvan, SK and Barkla, SE and Perez-Gonzalez, A and Suggett, DJ and Blackall, LL and van Oppen, MJH}, title = {Correction to: Intracellular bacteria are common and taxonomically diverse in cultured and in hospite algal endosymbionts of coral reefs.}, journal = {The ISME journal}, volume = {15}, number = {7}, pages = {2168-2170}, doi = {10.1038/s41396-021-00970-6}, pmid = {33854192}, issn = {1751-7370}, }
@article {pmid33853946, year = {2021}, author = {Carrier, TJ and Leigh, BA and Deaker, DJ and Devens, HR and Wray, GA and Bordenstein, SR and Byrne, M and Reitzel, AM}, title = {Microbiome reduction and endosymbiont gain from a switch in sea urchin life history.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {118}, number = {16}, pages = {}, pmid = {33853946}, issn = {1091-6490}, support = {R01 AI132581/AI/NIAID NIH HHS/United States ; }, mesh = {Adaptation, Biological/genetics ; Animals ; Biological Evolution ; Gastrointestinal Tract/*microbiology/physiology ; Microbiota/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sea Urchins/genetics/*microbiology ; Symbiosis/*genetics ; }, abstract = {Animal gastrointestinal tracts harbor a microbiome that is integral to host function, yet species from diverse phyla have evolved a reduced digestive system or lost it completely. Whether such changes are associated with alterations in the diversity and/or abundance of the microbiome remains an untested hypothesis in evolutionary symbiosis. Here, using the life history transition from planktotrophy (feeding) to lecithotrophy (nonfeeding) in the sea urchin Heliocidaris, we demonstrate that the lack of a functional gut corresponds with a reduction in microbial community diversity and abundance as well as the association with a diet-specific microbiome. We also determine that the lecithotroph vertically transmits a Rickettsiales that may complement host nutrition through amino acid biosynthesis and influence host reproduction. Our results indicate that the evolutionary loss of a functional gut correlates with a reduction in the microbiome and the association with an endosymbiont. Symbiotic transitions can therefore accompany life history transitions in the evolution of developmental strategies.}, }
@article {pmid33850182, year = {2021}, author = {Tekle, YI and Lyttle, JM and Blasingame, MG and Wang, F}, title = {Comprehensive comparative genomics reveals over 50 phyla of free-living and pathogenic bacteria are associated with diverse members of the amoebozoa.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {8043}, pmid = {33850182}, issn = {2045-2322}, support = {R15 GM116103/GM/NIGMS NIH HHS/United States ; }, mesh = {*Amoeba ; *Amoebozoa ; *Bacteria ; *Genomics ; *Phylogeny ; }, abstract = {The Amoebozoa, a group containing predominantly amoeboid unicellular protists has been shown to play an important ecological role in controlling environmental bacteria. Amoebozoans not only graze bacteria but also serve as a safe niche for bacterial replication and harbor endosymbiotic bacteria including dangerous human pathogens. Despite their importance, only a few lineages of Amoebozoa have been studied in this regard. In this research, we conducted a comprehensive genomic and transcriptomic study with expansive taxon sampling by including representatives from the three known clades of the Amoebozoa. We used culture independent whole culture and single cell genomics/transcriptomics to investigate the association of bacteria with diverse amoebozoans. Relative to current published evidence, we recovered the largest number of bacterial phyla (64) and human pathogen genera (51) associated with the Amoebozoa. Using single cell genomics/transcriptomics we were able to determine up to 24 potential endosymbiotic bacterial phyla, some potentially endosymbionts. This includes the majority of multi-drug resistant pathogens designated as major public health threats. Our study demonstrates amoebozoans are associated with many more phylogenetically diverse bacterial phyla than previously recognized. It also shows that all amoebozoans are capable of harboring far more dangerous human pathogens than presently documented, making them of primal public health concern.}, }
@article {pmid33850043, year = {2021}, author = {Cui, WJ and Zhang, B and Zhao, R and Liu, LX and Jiao, J and Zhang, Z and Tian, CF}, title = {Lineage-Specific Rewiring of Core Pathways Predating Innovation of Legume Nodules Shapes Symbiotic Efficiency.}, journal = {mSystems}, volume = {6}, number = {2}, pages = {}, pmid = {33850043}, issn = {2379-5077}, abstract = {The interkingdom coevolution innovated the rhizobium-legume symbiosis. The application of this nitrogen-fixing system in sustainable agriculture is usually impeded by incompatible interactions between partners. However, the progressive evolution of rhizobium-legume compatibility remains elusive. In this work, deletions of rhcV encoding a structural component of the type three secretion system allow related Sinorhizobium strains to nodulate a previously incompatible soybean cultivar (Glycine max). These rhcV mutants show low to medium to high symbiotic efficiency on the same cultivated soybean while being indistinguishable on wild soybean plants (Glycine soja). The dual pantranscriptomics reveals nodule-specific activation of core symbiosis genes of Sinorhizobium and Glycine genes associated with genome duplication events along the chronogram. Unexpectedly, symbiotic efficiency is in line with lineage-dependent transcriptional profiles of core pathways which predate the diversification of Fabaceae and Sinorhizobium. This is supported by further physiological and biochemical experiments. Particularly, low-efficiency nodules show disordered antioxidant activity and low-energy status, which restrict nitrogen fixation activity. Collectively, the ancient core pathways play a crucial role in optimizing the function of later-evolved mutualistic arsenals in the rhizobium-legume coevolution.IMPORTANCE Significant roles of complex extracellular microbiota in environmental adaptation of eukaryotes in ever-changing circumstances have been revealed. Given the intracellular infection ability, facultative endosymbionts can be considered pioneers within complex extracellular microbiota and are ideal organisms for understanding the early stage of interkingdom adaptation. This work reveals that the later innovation of key symbiotic arsenals and the lineage-specific network rewiring in ancient core pathways, predating the divergence of legumes and rhizobia, underline the progressive evolution of rhizobium-legume compatibility. This insight not only is significant for improving the application benefits of rhizobial inoculants in sustainable agriculture but also advances our general understanding of the interkingdom coevolution which is theoretically explored by all host-microbiota interactions.}, }
@article {pmid33848694, year = {2021}, author = {Pang, HE and Poquita-Du, RC and Jain, SS and Huang, D and Todd, PA}, title = {Among-genotype responses of the coral Pocillopora acuta to emersion: implications for the ecological engineering of artificial coastal defences.}, journal = {Marine environmental research}, volume = {168}, number = {}, pages = {105312}, doi = {10.1016/j.marenvres.2021.105312}, pmid = {33848694}, issn = {1879-0291}, mesh = {Animals ; *Anthozoa/genetics ; Chlorophyll A ; Coral Reefs ; Genotype ; Salinity ; Sunlight ; }, abstract = {Stony corals are promising transplant candidates for the ecological engineering of artificial coastal defences such as seawalls as they attract and host numerous other organisms. However, seawalls are exposed to a wide range of environmental stressors associated with periods of emersion during low tide such as desiccation and changes in salinity, temperature, and solar irradiance. All of these variables have known deleterious effects on coral physiology, growth, and fitness. In this study, we performed parallel experiments (in situ and ex situ) to examine among-genotype responses of Pocillopora acuta to emersion by quantifying growth, photophysiological metrics (Fv/Fm, non-photochemical quenching [NPQ], endosymbiont density, and chlorophyll [chl] a concentration) and survival, following different emersion periods. Results showed that coral fragments emersed for longer durations (>2 h) exhibited reduced growth and survival. Endosymbiont density and NPQ, but not Fv/Fm and chl a concentration, varied significantly among genotypes across different durations of emersion. Overall, the ability of P. acuta to tolerate emersion for up to 2 h suggests its potential to serve as a 'starter species' for transplantation efforts on seawalls. Further, careful characterisation and selection of genotypes with a high capacity to withstand emersion can help maximise the efficacy of ecological engineering using coral transplants.}, }
@article {pmid33848483, year = {2021}, author = {Lhee, D and Bhattacharya, D and Yoon, HS}, title = {Independent evolution of the thioredoxin system in photosynthetic Paulinella species.}, journal = {Current biology : CB}, volume = {31}, number = {7}, pages = {R328-R329}, pmid = {33848483}, issn = {1879-0445}, support = {80NSSC19K0462/ImNASA/Intramural NASA/United States ; }, mesh = {Amoeba ; Chromatophores ; *Evolution, Molecular ; *Photosynthesis ; Phylogeny ; Plastids ; *Rhizaria/metabolism ; Symbiosis ; Thioredoxins/*metabolism ; }, abstract = {Redox regulation allows phytoplankton to monitor and stabilize metabolic pathways under changing conditions[1]. In plastids, the thioredoxin (TRX) system is linked to photosynthetic electron transport and fine tuning of metabolic pathways to fluctuating light levels. Expansion of the number of redox signal transmitters and their protein targets, as seen in plants, is believed to increase cell robustness[2]. In this study, we searched for genes related to redox regulation in the photosynthetic amoeba Paulinella micropora KR01 (hereafter, KR01). The genus Paulinella includes testate filose amoebae, in which a single clade acquired a photosynthetic organelle, the chromatophore, from an alpha-cyanobacterial donor[3]. This independent primary endosymbiosis occurred relatively recently (∼124 million years ago) when compared to Archaeplastida (>1 billion years ago), making photosynthetic Paulinella a valuable model for studying the early stages of primary endosymbiosis[4]. Our comparative analysis demonstrates that this lineage has evolved a TRX system similar to other algae, relying, however, on genes with diverse phylogenetic origins (including the endosymbiont, host, bacteria, and red algae). One TRX of eukaryotic provenance is targeted to the chromatophore, implicating host-endosymbiont coordination of redox regulation. A chromatophore-targeted glucose-6-phosphate dehydrogenase (G6PDH) of red algal origin suggests that Paulinella exploited the existing redox regulation system in Archaeplastida to foster integration. Our study elucidates the independent evolution of the TRX system in photosynthetic Paulinella, whose parts derive from the existing genetic toolkit in diverse organisms.}, }
@article {pmid33842580, year = {2021}, author = {Beliavskaia, A and Hönig, V and Erhart, J and Vyhlidalova, T and Palus, M and Cerny, J and Kozlova, I and Ruzek, D and Palomar, AM and Bell-Sakyi, L}, title = {Spiroplasma Isolated From Third-Generation Laboratory Colony Ixodes persulcatus Ticks.}, journal = {Frontiers in veterinary science}, volume = {8}, number = {}, pages = {659786}, pmid = {33842580}, issn = {2297-1769}, abstract = {Spiroplasma are vertically-transmitted endosymbionts of ticks and other arthropods. Field-collected Ixodes persulcatus have been reported to harbour Spiroplasma, but nothing is known about their persistence during laboratory colonisation of this tick species. We successfully isolated Spiroplasma from internal organs of 6/10 unfed adult ticks, belonging to the third generation of an I. persulcatus laboratory colony, into tick cell culture. We screened a further 51 adult male and female ticks from the same colony for presence of Spiroplasma by genus-specific PCR amplification of fragments of the 16S rRNA and rpoB genes; 100% of these ticks were infected and the 16S rRNA sequence showed 99.8% similarity to that of a previously-published Spiroplasma isolated from field-collected I. persulcatus. Our study shows that Spiroplasma endosymbionts persist at high prevalence in colonised I. persulcatus through at least three generations, and confirms the usefulness of tick cell lines for isolation and cultivation of this bacterium.}, }
@article {pmid33837831, year = {2021}, author = {Joseph, R and Keyhani, NO}, title = {Fungal mutualisms and pathosystems: life and death in the ambrosia beetle mycangia.}, journal = {Applied microbiology and biotechnology}, volume = {105}, number = {9}, pages = {3393-3410}, pmid = {33837831}, issn = {1432-0614}, mesh = {Ambrosia ; Animals ; *Coleoptera ; Hong Kong ; Phylogeny ; Symbiosis ; *Weevils ; }, abstract = {Ambrosia beetles and their microbial communities, housed in specialized structures termed mycangia, represent one of the oldest and most diverse systems of mutualism and parasitism described thus far. Comprised of core filamentous fungal members, but also including bacteria and yeasts, the mycangia represent a unique adaptation that allows beetles to store and transport their source of nutrition. Although perhaps the most ancient of "farmers," the nature of these interactions remains largely understudied, with the exception of a handful of emerging pathosystems, where the fungal partner acts as a potentially devastating tree pathogen. Such virulence is often seen during "invasions," where (invasive) beetles carrying the fungal symbiont/plant pathogen expand into new territories and presumably "naïve" trees. Here, we summarize recent findings on the phylogenetic relationships between beetles and their symbionts and advances in the developmental and genetic characterization of the mechanisms that underlie insect-fungal-plant interactions. Results on genomic, transcriptomic, and metabolomic aspects of these relationships are described. Although many members of the fungal Raffaelea-beetle symbiont genera are relatively harmless to host trees, specialized pathosystems including wilt diseases of laurel and oak, caused by specific subspecies (R. lauricola and R. quercus, in the USA and East Asia, respectively), have emerged as potent plant pathogens capable of killing healthy trees. With the development of genetic tools, coupled to biochemical and microscopic techniques, the ambrosia beetle-fungal symbiont is establishing itself as a unique model system to study the molecular determinants and mechanisms that underlie the convergences of symbioses, mutualism, parasitism, and virulence. KEY POINTS: • Fungal-beetle symbioses are diverse and ancient examples of microbial farming. • The mycangium is a specialized structure on insects that houses microbial symbionts. • Some beetle symbiotic fungi are potent plant pathogens vectored by the insect.}, }
@article {pmid33831149, year = {2021}, author = {Pers, D and Hansen, AK}, title = {The boom and bust of the aphid's essential amino acid metabolism across nymphal development.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {9}, pages = {}, pmid = {33831149}, issn = {2160-1836}, mesh = {Amino Acids, Essential ; Animals ; *Aphids/genetics ; *Buchnera/genetics ; Plants ; Symbiosis ; }, abstract = {Within long-term symbioses, animals integrate their physiology and development with their symbiont. In a model nutritional mutualism, aphids harbor the endosymbiont, Buchnera, within specialized bacteriocyte cells. Buchnera synthesizes essential amino acids (EAAs) and vitamins for their host, which are lacking from the aphid's plant sap diet. It is unclear if the aphid host differentially expresses aphid EAA metabolism pathways and genes that collaborate with Buchnera for the production of EAA and vitamins throughout nymphal development when feeding on plants. It is also unclear if aphid bacteriocytes are differentially methylated throughout aphid development as DNA methylation may play a role in gene regulation. By analyzing aphid gene expression, we determined that the bacteriocyte is metabolically more active in metabolizing Buchnera's EAAs and vitamins early in nymphal development compared to intermediate or later immature and adult lifestages. The largest changes in aphid bacteriocyte gene expression, especially for aphid genes that collaborate with Buchnera, occurred during the 3rd to 4th instar transition. During this transition, there is a huge shift in the bacteriocyte from a high energy "nutrient-consuming state" to a "recovery and growth state" where patterning and signaling genes and pathways are upregulated and differentially methylated, and de novo methylation is reduced as evidenced by homogenous DNA methylation profiles after the 2nd instar. Moreover, bacteriocyte number increased and Buchnera's titer decreased throughout aphid nymphal development. These data suggest in combination that bacteriocytes of older nymphal and adult lifestages depend less on the nutritional symbiosis compared to early nymphal lifestages.}, }
@article {pmid33826895, year = {2021}, author = {Özsoy, &#x15e; and Vujovic, F and Simonian, M and Valova, V and Hunter, N and Farahani, RM}, title = {Cannibalized erythroblasts accelerate developmental neurogenesis by regulating mitochondrial dynamics.}, journal = {Cell reports}, volume = {35}, number = {1}, pages = {108942}, doi = {10.1016/j.celrep.2021.108942}, pmid = {33826895}, issn = {2211-1247}, support = {512524.3/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Chick Embryo ; Erythroblasts/*metabolism ; Guanosine Triphosphate/metabolism ; Heme/metabolism ; Male ; Mice, Inbred C57BL ; Mitochondria/metabolism ; *Mitochondrial Dynamics ; Monomeric GTP-Binding Proteins/metabolism ; Neural Tube/metabolism ; *Neurogenesis ; Protein Stability ; Reactive Oxygen Species/metabolism ; Transcription, Genetic ; beta Catenin/metabolism ; }, abstract = {Metabolic support was long considered to be the only developmental function of hematopoiesis, a view that is gradually changing. Here, we disclose a mechanism triggered during neurulation that programs brain development by donation of sacrificial yolk sac erythroblasts to neuroepithelial cells. At embryonic day (E) 8.5, neuroepithelial cells transiently integrate with the endothelium of yolk sac blood vessels and cannibalize intravascular erythroblasts as transient heme-rich endosymbionts. This cannibalistic behavior instructs precocious neuronal differentiation of neuroepithelial cells in the proximity of blood vessels. By experiments in vitro, we show that access to erythroblastic heme accelerates the pace of neurogenesis by induction of a truncated neurogenic differentiation program from a poised state. Mechanistically, the poised state is invoked by activation of the mitochondrial electron transport chain that leads to amplified production of reactive oxygen species in addition to omnipresent guanosine triphosphate (GTP) with consequential upregulation of pro-differentiation β-catenin.}, }
@article {pmid33824193, year = {2021}, author = {Daisley, BA and Reid, G}, title = {BEExact: a Metataxonomic Database Tool for High-Resolution Inference of Bee-Associated Microbial Communities.}, journal = {mSystems}, volume = {6}, number = {2}, pages = {}, pmid = {33824193}, issn = {2379-5077}, abstract = {High-throughput 16S rRNA gene sequencing technologies have robust potential to improve our understanding of bee (Hymenoptera: Apoidea)-associated microbial communities and their impact on hive health and disease. Despite recent computation algorithms now permitting exact inferencing of high-resolution exact amplicon sequence variants (ASVs), the taxonomic classification of these ASVs remains a challenge due to inadequate reference databases. To address this, we assemble a comprehensive data set of all publicly available bee-associated 16S rRNA gene sequences, systematically annotate poorly resolved identities via inclusion of 618 placeholder labels for uncultivated microbial dark matter, and correct for phylogenetic inconsistencies using a complementary set of distance-based and maximum likelihood correction strategies. To benchmark the resultant database (BEExact), we compare performance against all existing reference databases in silico using a variety of classifier algorithms to produce probabilistic confidence scores. We also validate realistic classification rates on an independent set of ∼234 million short-read sequences derived from 32 studies encompassing 50 different bee types (36 eusocial and 14 solitary). Species-level classification rates on short-read ASVs range from 80 to 90% using BEExact (with ∼20% due to "bxid" placeholder names), whereas only ∼30% at best can be resolved with current universal databases. A series of data-driven recommendations are developed for future studies. We conclude that BEExact (https://github.com/bdaisley/BEExact) enables accurate and standardized microbiota profiling across a broad range of bee species-two factors of key importance to reproducibility and meaningful knowledge exchange within the scientific community that together, can enhance the overall utility and ecological relevance of routine 16S rRNA gene-based sequencing endeavors.IMPORTANCE The failure of current universal taxonomic databases to support the rapidly expanding field of bee microbiota research has led to many investigators relying on "in-house" reference sets or manual classification of sequence reads (usually based on BLAST searches), often with vague identity thresholds and subjective taxonomy choices. This time-consuming, error- and bias-prone process lacks standardization, cripples the potential for comparative cross-study analysis, and in many cases is likely to incorrectly sway study conclusions. BEExact is structured on and leverages several complementary bioinformatic techniques to enable refined inference of bee host-associated microbial communities without any other methodological modifications necessary. It also bridges the gap between current practical outcomes (i.e., phylotype-to-genus level constraints with 97% operational taxonomic units [OTUs]) and the theoretical resolution (i.e., species-to-strain level classification with 100% ASVs) attainable in future microbiota investigations. Other niche habitats could also likely benefit from customized database curation via implementation of the novel approaches introduced in this study.}, }
@article {pmid33823812, year = {2021}, author = {Vera-Ponce León, A and Dominguez-Mirazo, M and Bustamante-Brito, R and Higareda-Alvear, V and Rosenblueth, M and Martínez-Romero, E}, title = {Functional genomics of a Spiroplasma associated with the carmine cochineals Dactylopius coccus and Dactylopius opuntiae.}, journal = {BMC genomics}, volume = {22}, number = {1}, pages = {240}, pmid = {33823812}, issn = {1471-2164}, mesh = {Animals ; Carmine ; Female ; Genomics ; *Hemiptera ; Male ; *Spiroplasma/genetics ; }, abstract = {BACKGROUND: Spiroplasma is a widely distributed endosymbiont of insects, arthropods, and plants. In insects, Spiroplasma colonizes the gut, hemolymph, and reproductive organs of the host. Previous metagenomic surveys of the domesticated carmine cochineal Dactylopius coccus and the wild cochineal D. opuntiae reported sequences of Spiroplasma associated with these insects. However, there is no analysis of the genomic capabilities and the interaction of this Spiroplasma with Dactylopius.<br><br>RESULTS: Here we present three Spiroplasma genomes independently recovered from metagenomes of adult males and females of D. coccus, from two different populations, as well as from adult females of D. opuntiae. Single-copy gene analysis showed that these genomes were&#x2009;>&#x2009;92% complete. Phylogenomic analyses classified these genomes as new members of Spiroplasma ixodetis. Comparative genome analysis indicated that they exhibit fewer genes involved in amino acid and carbon catabolism compared to other spiroplasmas. Moreover, virulence factor-encoding genes (i.e., glpO, spaid and rip2) were found incomplete in these S. ixodetis genomes. We also detected an enrichment of genes encoding the type IV secretion system (T4SS) in S. ixodetis genomes of Dactylopius. A metratranscriptomic analysis of D. coccus showed that some of these T4SS genes (i.e., traG, virB4 and virD4) in addition to the superoxide dismutase sodA of S. ixodetis were overexpressed in the ovaries.<br><br>CONCLUSION: The symbiont S. ixodetis is a new member of the bacterial community of D. coccus and D. opuntiae. The recovery of incomplete virulence factor-encoding genes in S. ixodetis of Dactylopius suggests that this bacterium is a non-pathogenic symbiont. A high number of genes encoding the T4SS, in the S. ixodetis genomes and the overexpression of these genes in the ovary and hemolymph of the host suggest that S. ixodetis use the T4SS to interact with the Dactylopius cells. Moreover, the transcriptional differences of S. ixodetis among the gut, hemolymph and ovary tissues of D. coccus indicate that this bacterium can respond and adapt to the different conditions (e.g., oxidative stress) present within the host. All this evidence proposes that there is a strong interaction and molecular signaling in the symbiosis between S. ixodetis and the carmine cochineal Dactylopius.}, }
@article {pmid33817579, year = {2021}, author = {Row, S and Huang, YC and Deng, WM}, title = {Developmental regulation of oocyte lipid intake through 'patent' follicular epithelium in Drosophila melanogaster.}, journal = {iScience}, volume = {24}, number = {4}, pages = {102275}, pmid = {33817579}, issn = {2589-0042}, support = {R01 CA224381/CA/NCI NIH HHS/United States ; R01 CA227789/CA/NCI NIH HHS/United States ; R01 GM072562/GM/NIGMS NIH HHS/United States ; S10 OD021685/OD/NIH HHS/United States ; }, abstract = {Epithelia form protective permeability barriers that selectively allow the exchange of material while maintaining tissue integrity under extreme mechanical, chemical, and bacterial loads. Here, we report in the Drosophila follicular epithelium a developmentally regulated and evolutionarily conserved process "patency", wherein a breach is created in the epithelium at tricellular contacts during mid-vitellogenesis. In Drosophila, patency exhibits a strict temporal range potentially delimited by the transcription factor Tramtrack69 and a spatial pattern influenced by the dorsal-anterior signals of the follicular epithelium. Crucial for growth and lipid uptake by the oocyte, patency is also exploited by endosymbionts such as Spiroplasma pulsonii. Our findings reveal an evolutionarily conserved and developmentally regulated non-typical epithelial function in a classic model system.}, }
@article {pmid33813285, year = {2021}, author = {Daveu, R and Laurence, C and Bouju-Albert, A and Sassera, D and Plantard, O}, title = {Symbiont dynamics during the blood meal of Ixodes ricinus nymphs differ according to their sex.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {4}, pages = {101707}, doi = {10.1016/j.ttbdis.2021.101707}, pmid = {33813285}, issn = {1877-9603}, mesh = {Animals ; Female ; Ixodes/growth &amp; development/*microbiology ; Male ; Nymph/growth &amp; development/microbiology ; Rickettsiales/*physiology ; Sex Factors ; *Symbiosis ; }, abstract = {Ticks harbour rich and diverse microbiota and, among the microorganisms associated with them, endosymbionts are the subject of a growing interest due to their crucial role in the biology of their arthropod host. Midichloria mitochondrii is the main endosymbiont of the European tick Ixodes ricinus and is found in abundance in all I. ricinus females, while at a much lower density in males, where it is even absent in 56 % of the individuals. This endosymbiont is also known to increase in numbers after the blood meal of larvae, nymphs or females. Because of this difference in the prevalence of M. mitochondrii between the two sexes, surveying the density of these bacteria in nymphs that will become either females or males could help to understand the behaviour of Midichloria in its arthropod host. To this aim, we have set up an experimental design by building 3 groups of unfed nymphs based on their scutum and hypostome lengths. After engorgement, weighing and moulting of a subset of the nymphs, a significant difference in sex-ratio among the 3 groups was observed. In parallel, Midichloria load in individual nymphs was quantified by qPCR both before and after engorgement. No difference in either body mass or Midichloria load was observed at the unfed stage, but following engorgement, both features were significantly different between each size group. Our results demonstrate that symbiont dynamics during nymphal engorgement is different between the two sexes, resulting in a significantly higher Midichloria load in nymphs that will become females. The consequences of those findings on our understanding of the interplay between the endosymbiont and its arthropod host are discussed.}, }
@article {pmid33806926, year = {2021}, author = {Greczek-Stachura, M and Leśnicka, PZ and Tarcz, S and Rautian, M and Możdżeń, K}, title = {Genetic Diversity of Symbiotic Green Algae of Paramecium bursaria Syngens Originating from Distant Geographical Locations.}, journal = {Plants (Basel, Switzerland)}, volume = {10}, number = {3}, pages = {}, pmid = {33806926}, issn = {2223-7747}, abstract = {Paramecium bursaria (Ehrenberg 1831) is a ciliate species living in a symbiotic relationship with green algae. The aim of the study was to identify green algal symbionts of P. bursaria originating from distant geographical locations and to answer the question of whether the occurrence of endosymbiont taxa was correlated with a specific ciliate syngen (sexually separated sibling group). In a comparative analysis, we investigated 43 P. bursaria symbiont strains based on molecular features. Three DNA fragments were sequenced: two from the nuclear genomes-a fragment of the ITS1-5.8S rDNA-ITS2 region and a fragment of the gene encoding large subunit ribosomal RNA (28S rDNA), as well as a fragment of the plastid genome comprising the 3'rpl36-5'infA genes. The analysis of two ribosomal sequences showed the presence of 29 haplotypes (haplotype diversity Hd = 0.98736 for ITS1-5.8S rDNA-ITS2 and Hd = 0.908 for 28S rDNA) in the former two regions, and 36 haplotypes in the 3'rpl36-5'infA gene fragment (Hd = 0.984). The following symbiotic strains were identified: Chlorella vulgaris, Chlorella variabilis, Chlorella sorokiniana and Micractinium conductrix. We rejected the hypotheses concerning (i) the correlation between P. bursaria syngen and symbiotic species, and (ii) the relationship between symbiotic species and geographic distribution.}, }
@article {pmid33806260, year = {2021}, author = {Zepeda-Paulo, F and Lavandero, B}, title = {Effect of the Genotypic Variation of an Aphid Host on the Endosymbiont Associations in Natural Host Populations.}, journal = {Insects}, volume = {12}, number = {3}, pages = {}, pmid = {33806260}, issn = {2075-4450}, abstract = {Understanding the role of facultative endosymbionts on the host's ecology has been the main aim of the research in symbiont-host systems. However, current research on host-endosymbiont dynamics has failed to examine the genetic background of the hosts and its effect on host-endosymbiont associations in real populations. We have addressed the seasonal dynamic of facultative endosymbiont infections among different host clones of the grain aphid Sitobion avenae, on two cereal crops (wheat and oat) and whether their presence affects the total hymenopteran parasitism of aphid hosts at the field level. We present evidence of rapid seasonal shifts in the endosymbiont frequency, suggesting a positive selection of endosymbionts at the host-level (aphids) through an agricultural growing season, by two mechanisms; (1) an increase of aphid infections with endosymbionts over time, and (2) the seasonal replacement of host clones within natural populations by increasing the prevalence of aphid clones closely associated to endosymbionts. Our results highlight how genotypic variation of hosts can affect the endosymbiont prevalence in the field, being an important factor for understanding the magnitude and direction of the adaptive and/or maladaptive responses of hosts to the environment.}, }
@article {pmid33803682, year = {2021}, author = {Boularias, G and Azzag, N and Galon, C and Šimo, L and Boulouis, HJ and Moutailler, S}, title = {High-Throughput Microfluidic Real-Time PCR for the Detection of Multiple Microorganisms in Ixodid Cattle Ticks in Northeast Algeria.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {3}, pages = {}, pmid = {33803682}, issn = {2076-0817}, abstract = {Ixodid ticks are hematophagous arthropods considered to be prominent ectoparasite vectors that have a negative impact on cattle, either through direct injury or via the transmission of several pathogens. In this study, we investigated the molecular infection rates of numerous tick-borne pathogens in ticks sampled on cattle from the Kabylia region, northeastern Algeria, using a high-throughput microfluidic real-time PCR system. A total of 235 ticks belonging to seven species of the genera Rhipicephalus, Hyalomma, and Ixodes were sampled on cattle and then screened for the presence of 36 different species of bacteria and protozoans. The most prevalent tick-borne microorganisms were Rickettsia spp. at 79.1%, followed by Francisella-like endosymbionts (62.9%), Theileria spp. (17.8%), Anaplasma spp. (14.4%), Bartonella spp. (6.8%), Borrelia spp. (6.8%), and Babesia spp. (2.5%). Among the 80.4% of ticks bearing microorganisms, 20%, 36.6%, 21.7%, and 2.1% were positive for one, two, three, and four different microorganisms, respectively. Rickettsia aeschlimannii was detected in Hyalomma marginatum, Hyalomma detritum, and Rhipicephalus bursa ticks. Rickettsia massiliae was found in Rhipicephalus sanguineus, and Rickettsiamonacensis and Rickettsia helvetica were detected in Ixodesricinus. Anaplasma marginale was found in all identified tick genera, but Anaplasma centrale was detected exclusively in Rhipicephalus spp. ticks. The DNA of Borrelia spp. and Bartonella spp. was identified in several tick species. Theileria orientalis was found in R. bursa, R. sanguineus, H. detritum, H. marginatum, and I. ricinus and Babesia bigemina was found in Rhipicephalus annulatus and R. sanguineus. Our study highlights the importance of tick-borne pathogens in cattle in Algeria.}, }
@article {pmid33801932, year = {2021}, author = {Gałęcki, R and Jaroszewski, J and Bakuła, T and Galon, EM and Xuan, X}, title = {Molecular Detection of Selected Pathogens with Zoonotic Potential in Deer Keds (Lipoptena fortisetosa).}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {3}, pages = {}, pmid = {33801932}, issn = {2076-0817}, abstract = {Deer keds are obligatory hematophagous ectoparasites of birds and mammals. Cervids serve as specific hosts for these insects. However, ked infestations have been observed in non-specific hosts, including humans, companion animals, and livestock. Lipoptena fortisetosa is a weakly studied ectoparasite, but there is evidence to indicate that it continues to spread across Europe. The existing knowledge on deer keds' impact on wildlife is superficial, and their veterinary importance is enigmatic. Lipoptena fortisetosa is a species with vectorial capacity, but potential pathogen transmission has not been assessed. The objective of this study was to evaluate the prevalence of selected pathogens in L. fortisetosa collected from cervids and host-seeking individuals in the environment. Out of 500 acquired samples, 307 (61.4%) had genetic material from at least one tested pathogen. Our research suggests that L. fortisetosa may be a potential vector of several pathogens, including A. phagocytophilum, Babesia spp., Bartonella spp., Borellia spp., Coxiella-like endosymbionts, Francisiella tularensis, Mycoplasma spp., Rickettsia spp., and Theileria spp.; however, further, more extensive investigations are required to confirm this. The results of the study indicate that keds can be used as biological markers for investigating the prevalence of vector-borne diseases in the population of free-ranging cervids.}, }
@article {pmid33800543, year = {2021}, author = {Moelling, K and Broecker, F}, title = {Viroids and the Origin of Life.}, journal = {International journal of molecular sciences}, volume = {22}, number = {7}, pages = {}, pmid = {33800543}, issn = {1422-0067}, mesh = {Animals ; Gene Silencing ; Genetic Complementation Test ; Humans ; Meteoroids ; Nucleic Acid Conformation ; *Origin of Life ; Plant Diseases/virology ; RNA Interference ; RNA, Catalytic/*genetics ; RNA, Viral/*genetics ; Ribosomes/chemistry/*genetics ; Symbiosis ; Viroids/*genetics ; Virus Diseases/metabolism ; *Virus Replication ; }, abstract = {Viroids are non-coding circular RNA molecules with rod-like or branched structures. They are often ribozymes, characterized by catalytic RNA. They can perform many basic functions of life and may have played a role in evolution since the beginning of life on Earth. They can cleave, join, replicate, and undergo Darwinian evolution. Furthermore, ribozymes are the essential elements for protein synthesis of cellular organisms as parts of ribosomes. Thus, they must have preceded DNA and proteins during evolution. Here, we discuss the current evidence for viroids or viroid-like RNAs as a likely origin of life on Earth. As such, they may also be considered as models for life on other planets or moons in the solar system as well as on exoplanets.}, }
@article {pmid33794350, year = {2021}, author = {Konecka, E and Olszanowski, Z}, title = {Wolbachia supergroup E found in Hypochthonius rufulus (Acari: Oribatida) in Poland.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {91}, number = {}, pages = {104829}, doi = {10.1016/j.meegid.2021.104829}, pmid = {33794350}, issn = {1567-7257}, mesh = {Animals ; Mites/*microbiology ; Phylogeny ; Poland ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Data on the spread of intracellular bacteria in oribatid mites (Acari: Oribatida) are scarce. Our work fills a gap in the research on endosymbionts in this group of invertebrates and provides information on Wolbachia infection in Hypochthonius rufulus (Acari: Oribatida) from soil, litter and moss sample collected in south-eastern Poland. This is the first report of Wolbachia in H. rufulus. Phylogeny based on the analysis of the 16S rRNA, gatB, fbpA, gltA, ftsZ and hcpA gene sequences revealed that Wolbachia from H. rufulus represented supergroup E and was related to bacterial endosymbionts of Collembola. The unique sequence within Wolbachia supergroup E was detected for the 16S rRNA gene of the bacteria from H. rufulus. The sequences of Wolbachia 16S rRNA and housekeeping genes have been deposited in publicly available databases and are an important source of molecular data for comparative studies.}, }
@article {pmid33793664, year = {2021}, author = {Nooroong, P and Trinachartvanit, W and Baimai, V and Anuracpreeda, P and Ahantarig, A}, title = {Partial DnaK protein expression from Coxiella-like endosymbiont of Rhipicephalus annulatus tick.}, journal = {PloS one}, volume = {16}, number = {4}, pages = {e0249354}, pmid = {33793664}, issn = {1932-6203}, mesh = {Adenosine Triphosphatases/classification/genetics/immunology/*metabolism ; Amino Acid Sequence ; Animals ; Bacterial Proteins/classification/genetics/immunology/*metabolism ; Coxiella burnetii/isolation &amp; purification/*metabolism ; DNA, Bacterial/chemistry/metabolism ; Databases, Genetic ; Epitopes/analysis/immunology ; Haplotypes ; Mutation ; Phylogeny ; Recombinant Proteins/biosynthesis/chemistry/isolation &amp; purification ; Rhipicephalus/*microbiology ; Symbiosis ; }, abstract = {Q fever is one of the most important zoonotic diseases caused by the obligate intracellular bacteria, Coxiella burnetii. This bacterial infection has been frequently reported in both humans and animals, especially ruminants. Ticks are important ectoparasite and serve as reservoir hosts of Coxiella-like endosymbionts (CLEs). In this study, we have attempted to express chaperone-coding genes from CLEs of Rhipicephalus annulatus ticks collected fromcow path. The partial DnaK coding sequence has been amplified and expressed by Escherichia coli. Amino acid sequences have been analyzed by MS-MS spectrometry and the UniProt database. Despites nucleotide sequences indicating high nucleotide variation and diversity, many nucleotide substitutions are synonymous. In addition, amino acid substitutions compensate for the physicochemical properties of the original amino acids. Immune Epitope Database and Analysis Resource (IEDB-AR) was employed to indicate the antigenicity of the partial DnaK protein and predict the epitopes of B-and T-cells. Interestingly, some predicted HLA-A and B alleles of the MHC-I and HLA-DR alleles belonging to MHC-II were similar to T-cell responses to C. burnetii in Q fever patients. Therefore, the partial DnaK protein of CLE from R. annulatus could be considered a vaccine candidate and immunogenic marker with future prospects.}, }
@article {pmid33787747, year = {2021}, author = {Ribeiro, MF and Carvalho, VR and Favoreto, AL and De Marchi, BR and Jordan, C and Zanuncio, JC and Soares, MA and Zanuncio, AJV and Wilcken, CF}, title = {Yersinia massiliensis (Enterobacteriales: Enterobacteriaceae) in the host Anaphes nitens (Hymenoptera: Mymaridae): first report of association with insects.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {82}, number = {}, pages = {e237098}, doi = {10.1590/1519-6984.237098}, pmid = {33787747}, issn = {1678-4375}, mesh = {Animals ; Enterobacteriaceae/genetics ; *Hymenoptera/genetics ; *Weevils ; Yersinia/genetics ; }, abstract = {Endosymbiont bacteria can affect biological parameters and reduce the effectiveness of natural enemies in controlling the target insect. The objective of this work was to identify endosymbiont bacteria in Anaphes nitens (Girault, 1928) (Hymenoptera: Mymaridae), the main natural enemy used to manage Gonipterus platensis (Marelli, 1926) (Coleoptera: Curculionidae). Genomic DNA from six A. nitens populations was extracted and polymerase chain reactions (PCR) were performed with the primers to detect endosymbiont bacteria in this insect. The PCR products were amplified, sequenced, and compared with sequences deposited in the GenBank for the bacteria identification. All A. nitens populations had the bacterium Yersinia massiliensis (Enterobacteriales: Enterobacteriaceae). This bacterium was originally described as free-living, and it is associated with and composes part of the A. nitens microbiota. This is the first report of Y. massiliensis in an insect host.}, }
@article {pmid33786972, year = {2021}, author = {Shang, J and Yao, YS and Zhu, XZ and Wang, L and Li, DY and Zhang, KX and Gao, XK and Wu, CC and Niu, L and Ji, JC and Luo, JY and Cui, JJ}, title = {Evaluation of sublethal and transgenerational effects of sulfoxaflor on Aphis gossypii via life table parameters and 16S rRNA sequencing.}, journal = {Pest management science}, volume = {77}, number = {7}, pages = {3406-3418}, doi = {10.1002/ps.6385}, pmid = {33786972}, issn = {1526-4998}, mesh = {Animals ; *Aphids/genetics ; Humans ; Life Tables ; Pyridines ; RNA, Ribosomal, 16S/genetics ; Sulfur Compounds/toxicity ; }, abstract = {BACKGROUND: Aphis gossypii, a polyphagous and recurrent pest induced by pesticides, causes tremendous loss crop yields each year. Previous studies on the mechanism of pesticide-induced sublethal effects mainly focus on the gene level. The symbiotic bacteria are also important participants of this mechanism, but their roles in hormesis are still unclear.<br><br>RESULTS: In this study, life table parameters and 16S rRNA sequencing were applied to evaluate the sublethal and transgenerational effects of sulfoxaflor on adult A. gossypii after 24-h LC20 (6.96&#x2009;mg&#x2009;L[-1]) concentration exposure. The results indicated that the LC20 of sulfoxaflor significantly reduced the finite rate of increase (&#x3bb;) and net reproductive rate (R0) of parent generation (G0), and significantly increased mean generation time (T) of G1 and G2, but not of G3 and G4. Both reproductive period and fecundity of G1 and G2 were significantly higher than those of the control. Furthermore, our sequencing data revealed that more than 95% bacterial communities were dominated by the phylum Proteobacteria, in which the maximum proportion genus was the primary symbiont Buchnera and the facultative symbiont Arsenophonus. Compared to those of the control, the abundance and composition of symbiotic bacteria of A. gossypii for three successive generations (G0-G2) were changed after G0 A. gossypii was exposed to sulfoxaflor: the diversity of the bacterial community was decreased, but the abundance of Buchnera was increased (G0), while the abundance of Arsenophonus was decreased. Contrary to G0, G1 and G2 cotton aphid exhibited an increased relative abundance of Arsenophonus in the sublethal treatment group.<br><br>CONCLUSION: Taken together, our results provide an insight into the interactions among pesticide resistance, aphids, and symbionts, which will eventually help to better manage the resurgence of A. gossypii. &#xa9; 2021 Society of Chemical Industry.}, }
@article {pmid33786050, year = {2021}, author = {Ertabaklar, H and Malatyali, E and Özün Özbay, EP and Yildiz, &#x130; and Sinecen, M and Ertuğ, S and Bozdoğan, B and Güçlü, &#xd6;}, title = {Microsatellite-Based Genotyping, Analysis of Population Structure, Presence of Trichomonas vaginalis Virus (TVV) and Mycoplasma hominis in T. vaginalis Isolates from Southwest of Turkey.}, journal = {Iranian journal of parasitology}, volume = {16}, number = {1}, pages = {81-90}, pmid = {33786050}, issn = {1735-7020}, abstract = {BACKGROUND: The present study aimed to determine genetic diversity of Trichomonas vaginalis (T. vaginalis) isolates with microsatellite markers in Turkey (Nov 2015 to 2016) and to create a web-based microsatellite typing (MT) approach for the global interpretation of the data. In addition, the endosymbiosis of Mycoplasma hominis (M. hominis) and T. vaginalis virus (TVV) in the isolates was also examined.<br><br>METHODS: The allele sizes for each locus were calculated and microsatellite types were determined according to the allele profiles. The population structure was examined with Bayesian clustering method. A website (http://mttype.adu.edu.tr) was created for collection and sharing of microsatellite data. Presence of TVV and M. hominis in T. vaginalis isolates were investigated with electrophoresis and PCR.<br><br>RESULTS: Of 630 vaginal samples T. vaginalis was detected in 30 (4.7%) and those were used for further analysis. The structure produced by a clustering algorithm revealed eight genetic groups. The typing of isolates according to microsatellites revealed 23 different microsatellite types. Three clones were determined among isolates (MT10 16.7%; MT18 10% and MT3 6.7%). The frequency of TVV and M. hominis was 16.6% (n=5) and 20% (n=6), respectively.<br><br>CONCLUSION: Presence of three clones among 30 T. vaginalis isolates indicated that microsatellite-based genotyping was efficient to determine the clonal distribution of T. vaginalis isolates. Therefore, a promising tool might be developed further and adapted to the studies dealing with molecular epidemiology of T. vaginalis. Microsatellite data from forthcoming studies will be deposited and presented on the website. In addition, we also presented the frequency of two endosymbionts in T. vaginalis isolates for the first time in Turkey.}, }
@article {pmid33785618, year = {2021}, author = {Ledermann, R and Emmenegger, B and Couzigou, JM and Zamboni, N and Kiefer, P and Vorholt, JA and Fischer, HM}, title = {Bradyrhizobium diazoefficiens Requires Chemical Chaperones To Cope with Osmotic Stress during Soybean Infection.}, journal = {mBio}, volume = {12}, number = {2}, pages = {}, pmid = {33785618}, issn = {2150-7511}, mesh = {Amino Acids, Diamino/metabolism ; Bacterial Proteins/genetics/metabolism ; Betaine/metabolism ; Bradyrhizobium/genetics/*metabolism ; Osmotic Pressure ; Plant Root Nodulation ; Root Nodules, Plant/growth &amp; development/microbiology ; Soybeans/growth &amp; development/*microbiology ; Trehalose/*metabolism ; }, abstract = {When engaging in symbiosis with legume hosts, rhizobia are confronted with environmental changes, including nutrient availability and stress exposure. Genetic circuits allow responding to these environmental stimuli to optimize physiological adaptations during the switch from the free-living to the symbiotic life style. A pivotal regulatory system of the nitrogen-fixing soybean endosymbiont Bradyrhizobium diazoefficiens for efficient symbiosis is the general stress response (GSR), which relies on the alternative sigma factor σ[EcfG] However, the GSR-controlled process required for symbiosis has not been identified. Here, we demonstrate that biosynthesis of trehalose is under GSR control, and mutants lacking the respective biosynthetic genes otsA and/or otsB phenocopy GSR-deficient mutants under symbiotic and selected free-living stress conditions. The role of trehalose as a cytoplasmic chemical chaperone and stress protectant can be functionally replaced in an otsA or otsB mutant by introducing heterologous genetic pathways for biosynthesis of the chemically unrelated compatible solutes glycine betaine and (hydroxy)ectoine. Alternatively, uptake of exogenously provided trehalose also restores efficient symbiosis and tolerance to hyperosmotic and hyperionic stress of otsA mutants. Hence, elevated cytoplasmic trehalose levels resulting from GSR-controlled biosynthesis are crucial for B. diazoefficiens cells to overcome adverse conditions during early stages of host infection and ensure synchronization with root nodule development.IMPORTANCE The Bradyrhizobium-soybean symbiosis is of great agricultural significance and serves as a model system for fundamental research in bacterium-plant interactions. While detailed molecular insight is available about mutual recognition and early nodule organogenesis, our understanding of the host-imposed conditions and the physiology of infecting rhizobia during the transition from a free-living state in the rhizosphere to endosymbiotic bacteroids is currently limited. In this study, we show that the requirement of the rhizobial general stress response (GSR) during host infection is attributable to GSR-controlled biosynthesis of trehalose. Specifically, trehalose is crucial for an efficient symbiosis by acting as a chemical chaperone to protect rhizobia from osmostress during host infection.}, }
@article {pmid33776981, year = {2021}, author = {Flatau, R and Segoli, M and Hawlena, H}, title = {Wolbachia Endosymbionts of Fleas Occur in All Females but Rarely in Males and Do Not Show Evidence of Obligatory Relationships, Fitness Effects, or Sex-Distorting Manipulations.}, journal = {Frontiers in microbiology}, volume = {12}, number = {}, pages = {649248}, pmid = {33776981}, issn = {1664-302X}, abstract = {The widespread temporal and spatial persistence of endosymbionts in arthropod host populations, despite potential conflicts with their hosts and fluctuating environmental conditions, is puzzling. Here, we disentangled three main mechanisms that are commonly proposed to explain such persistence, namely, obligatory relationships, in which the host is fully dependent on its endosymbiont, fitness advantages conferred by the endosymbiont, and reproductive manipulations imposed by the endosymbiont. Our model system reflects an extreme case, in which the Wolbachia endosymbiont persists in all female flea hosts but rarely in male ones. We cured fleas of both sexes of Wolbachia but found no indications for either lower reproduction, offspring survival, or a change in the offspring sex ratio, compared to Wolbacia-infected fleas. These results do not support any of the suggested mechanisms. We highlight future directions to advance our understanding of endosymbiont persistence in fleas, as well as in other model systems, with extreme sex-differences in endosymbiont persistence. Insights from such studies are predicted to shed light on the evolution and ecology of arthropod-endosymbiont interactions in nature.}, }
@article {pmid33774874, year = {2021}, author = {Chen, H and Wang, M and Li, M and Lian, C and Zhou, L and Zhang, X and Zhang, H and Zhong, Z and Wang, H and Cao, L and Li, C}, title = {A glimpse of deep-sea adaptation in chemosynthetic holobionts: Depressurization causes DNA fragmentation and cell death of methanotrophic endosymbionts rather than their deep-sea Bathymodiolinae host.}, journal = {Molecular ecology}, volume = {30}, number = {10}, pages = {2298-2312}, doi = {10.1111/mec.15904}, pmid = {33774874}, issn = {1365-294X}, mesh = {Acclimatization ; Animals ; Cell Death ; DNA Fragmentation ; *Hydrothermal Vents ; *Mytilidae ; Phylogeny ; Symbiosis/genetics ; }, abstract = {Bathymodiolinae mussels are typical species in deep-sea cold seeps and hydrothermal vents and an ideal model for investigating chemosynthetic symbiosis and the influence of high hydrostatic pressure on deep-sea organisms. Herein, the potential influence of depressurization on DNA fragmentation and cell death in Bathymodiolinae hosts and their methanotrophic symbionts were surveyed using isobaric and unpressurized samples. As a hallmark of cell death, massive DNA fragmentation was observed in methanotrophic symbionts from unpressurized Bathymodiolinae while several endonucleases and restriction enzymes were upregulated. Additionally, genes involved in DNA repair, glucose/methane metabolism as well as two-component regulatory system were also differentially expressed in depressurized symbionts. DNA fragmentation and programmed cell death, however, were rarely detected in the host bacteriocytes owing to the orchestrated upregulation of inhibitor of apoptosis genes and downregulation of caspase genes. Meanwhile, diverse host immune recognition receptors were promoted during depressurization, probably enabling the regain of symbionts. When the holobionts were subjected to a prolonged acclimation at atmospheric pressure, alternations in both the DNA fragmentation and the expression atlas of aforesaid genes were continuously observed in symbionts, demonstrating the persistent influence of depressurization. Contrarily, the host cells demonstrated certain tolerance against depressurization stress as expression level of some immune-related genes returned to the basal level in isobaric samples. Altogether, the present study illustrates the distinct stress responses of Bathymodiolinae hosts and their methanotrophic symbionts against depressurization, which could provide further insight into the deep-sea adaptation of Bathymodiolinae holobionts while highlighting the necessity of using isobaric sampling methods in deep-sea research.}, }
@article {pmid33769570, year = {2021}, author = {Katlav, A and Nguyen, DT and Cook, JM and Riegler, M}, title = {Constrained sex allocation after mating in a haplodiploid thrips species depends on maternal condition.}, journal = {Evolution; international journal of organic evolution}, volume = {75}, number = {6}, pages = {1525-1536}, doi = {10.1111/evo.14217}, pmid = {33769570}, issn = {1558-5646}, mesh = {Animals ; Body Size ; Crosses, Genetic ; Female ; Fertilization ; Genetic Fitness ; Male ; Ovum ; Paternal Inheritance ; Reproduction ; *Sex Ratio ; Sexual Behavior, Animal ; Thysanoptera/*genetics/physiology ; Time Factors ; }, abstract = {In females of haplodiploid animals, female production requires fertilization, whereas male production does not. Therefore, haplodiploid species can display extraordinary sex ratios. Constrained sex allocation occurs when a female cannot produce daughters. This can be due to virginity but may also occur after mating due to insemination failure, selfish genetic elements or physiological constraints. Here, we investigated the mechanism underlying constrained sex allocation in Pezothrips kellyanus. In this species some mated females produce highly female-biased broods, yet, for unknown reasons, others produce extremely male-biased broods. Using crossing experiments controlled for maternally inherited endosymbionts we confirmed that constrained females were successfully inseminated. Furthermore, male-biased offspring production was not paternally inherited, ruling out paternal sex ratio elements previously identified as sex ratio distorters in some parasitoid wasps. Next, we excluded mating time and paternal fitness effects (male size) on sex allocation. However, we found that constrained sex allocation only occurred in small females producing smaller eggs than large females producing larger eggs and female-biased broods. Consequently, the bimodal sex allocation pattern correlates with maternal condition, and may have arisen (adaptively or non-adaptively) in association with an egg size-mediated fertilization mechanism recently detected in some haplodiploids, with egg size positively affecting fertilization success.}, }
@article {pmid33765083, year = {2021}, author = {Reverte, M and Eren, RO and Jha, B and Desponds, C and Snäkä, T and Prevel, F and Isorce, N and Lye, LF and Owens, KL and Gazos Lopes, U and Beverley, SM and Fasel, N}, title = {The antioxidant response favors Leishmania parasites survival, limits inflammation and reprograms the host cell metabolism.}, journal = {PLoS pathogens}, volume = {17}, number = {3}, pages = {e1009422}, pmid = {33765083}, issn = {1553-7374}, support = {R01 AI031078/AI/NIAID NIH HHS/United States ; R01 AI130222/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Host-Parasite Interactions/*physiology ; Inflammation/immunology/metabolism ; Leishmania/immunology/*metabolism ; Leishmaniasis/immunology/*metabolism ; Mice ; NF-E2-Related Factor 2/immunology/*metabolism ; Oxidative Stress/*physiology ; Signal Transduction/immunology ; }, abstract = {The oxidative burst generated by the host immune system can restrict intracellular parasite entry and growth. While this burst leads to the induction of antioxidative enzymes, the molecular mechanisms and the consequences of this counter-response on the life of intracellular human parasites are largely unknown. The transcription factor NF-E2-related factor (NRF2) could be a key mediator of antioxidant signaling during infection due to the entry of parasites. Here, we showed that NRF2 was strongly upregulated in infection with the human Leishmania protozoan parasites, its activation was dependent on a NADPH oxidase 2 (NOX2) and SRC family of protein tyrosine kinases (SFKs) signaling pathway and it reprogrammed host cell metabolism. In inflammatory leishmaniasis caused by a viral endosymbiont inducing TNF-α in chronic leishmaniasis, NRF2 activation promoted parasite persistence but limited TNF-α production and tissue destruction. These data provided evidence of the dual role of NRF2 in protecting both the invading pathogen from reactive oxygen species and the host from an excess of the TNF-α destructive pro-inflammatory cytokine.}, }
@article {pmid33764469, year = {2021}, author = {Pilgrim, J and Thongprem, P and Davison, HR and Siozios, S and Baylis, M and Zakharov, EV and Ratnasingham, S and deWaard, JR and Macadam, CR and Smith, MA and Hurst, GDD}, title = {Torix Rickettsia are widespread in arthropods and reflect a neglected symbiosis.}, journal = {GigaScience}, volume = {10}, number = {3}, pages = {}, pmid = {33764469}, issn = {2047-217X}, support = {BB/M011186/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; *Arthropods/genetics ; Base Sequence ; Humans ; Phylogeny ; *Rickettsia/genetics ; Symbiosis ; }, abstract = {BACKGROUND: Rickettsia are intracellular bacteria best known as the causative agents of human and animal diseases. Although these medically important Rickettsia are often transmitted via haematophagous arthropods, other Rickettsia, such as those in the Torix group, appear to reside exclusively in invertebrates and protists with no secondary vertebrate host. Importantly, little is known about the diversity or host range of Torix group Rickettsia.<br><br>RESULTS: This study describes the serendipitous discovery of Rickettsia amplicons in the Barcode of Life Data System (BOLD), a sequence database specifically designed for the curation of mitochondrial DNA barcodes. Of 184,585 barcode sequences analysed, Rickettsia is observed in &#x223c;0.41% of barcode submissions and is more likely to be found than Wolbachia (0.17%). The Torix group of Rickettsia are shown to account for 95% of all unintended amplifications from the genus. A further targeted PCR screen of 1,612 individuals from 169 terrestrial and aquatic invertebrate species identified mostly Torix strains and supports the "aquatic hot spot" hypothesis for Torix infection. Furthermore, the analysis of 1,341 SRA deposits indicates that Torix infections represent a significant proportion of all Rickettsia symbioses found in arthropod genome projects.<br><br>CONCLUSIONS: This study supports a previous hypothesis that suggests that Torix Rickettsia are overrepresented in aquatic insects. In addition, multiple methods reveal further putative hot spots of Torix Rickettsia infection, including in phloem-feeding bugs, parasitoid wasps, spiders, and vectors of disease. The unknown host effects and transmission strategies of these endosymbionts make these newly discovered associations important to inform future directions of investigation involving the understudied Torix Rickettsia.}, }
@article {pmid33763389, year = {2021}, author = {Solbach, MD and Bonkowski, M and Dumack, K}, title = {Novel Endosymbionts in Rhizarian Amoebae Imply Universal Infection of Unrelated Free-Living Amoebae by Legionellales.}, journal = {Frontiers in cellular and infection microbiology}, volume = {11}, number = {}, pages = {642216}, pmid = {33763389}, issn = {2235-2988}, mesh = {*Amoeba ; *Amoebida ; Bacteria ; Humans ; *Legionella ; *Legionnaires' Disease ; }, abstract = {Legionellales-infected water is a frequent cause of local outbreaks of Legionnaires' disease and Pontiac fever. Decontaminations are difficult because Legionellales reproduce in eukaryotic microorganisms (protists). Most often, Legionellales have been isolated from amoebae; however, the culture-based sampling methods are taxonomically biased. Sequencing studies show that amoebae in the cercozoan class Thecofilosea are dominant in soils and wastewater treatment plants, prompting us to screen their capability to serve as potential hosts of endosymbiotic bacteria. Environmental isolates of Thecofilosea contained a surprising richness of endosymbiotic Legionellales, including Legionella. Considering the widespread dispersal of Legionellales in apparently unrelated amoeboid protist taxa, it appears that the morphotype and not the evolutionary origin of amoebae determines their suitability as hosts for Legionellales. We further provide a protocol for gnotobiotic cultivation of Legionellales and their respective hosts, facilitating future genomic and transcriptomic research of host-symbiont relationships.}, }
@article {pmid33762724, year = {2021}, author = {Schalm, G and Bruns, K and Drachenberg, N and Geyer, N and Foulkes, NS and Bertolucci, C and Gerlach, G}, title = {Finding Nemo's clock reveals switch from nocturnal to diurnal activity.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {6801}, pmid = {33762724}, issn = {2045-2322}, mesh = {Animals ; Circadian Clocks/*genetics ; Circadian Rhythm/physiology/radiation effects ; Coral Reefs ; DNA Repair/genetics ; Larva/genetics/metabolism ; Light ; Locomotion ; Perciformes/*genetics/growth &amp; development/physiology ; Transcriptome ; }, abstract = {Timing mechanisms play a key role in the biology of coral reef fish. Typically, fish larvae leave their reef after hatching, stay for a period in the open ocean before returning to the reef for settlement. During this dispersal, larvae use a time-compensated sun compass for orientation. However, the timing of settlement and how coral reef fish keep track of time via endogenous timing mechanisms is poorly understood. Here, we have studied the behavioural and genetic basis of diel rhythms in the clown anemonefish Amphiprion ocellaris. We document a behavioural shift from nocturnal larvae to diurnal adults, while juveniles show an intermediate pattern of activity which potentially indicates flexibility in the timing of settlement on a host anemone. qRTPCR analysis of six core circadian clock genes (bmal1, clocka, cry1b, per1b, per2, per3) reveals rhythmic gene expression patterns that are comparable in larvae and juveniles, and so do not reflect the corresponding activity changes. By establishing an embryonic cell line, we demonstrate that clown anemonefish possess an endogenous clock with similar properties to that of the zebrafish circadian clock. Furthermore, our study provides a first basis to study the multi-layered interaction of clocks from fish, anemones and their zooxanthellae endosymbionts.}, }
@article {pmid33761023, year = {2021}, author = {Clausi, M and Leone, D and Strano, A and Lizio, A and Rappazzo, G and Mulder, C and Conti, E}, title = {Effects of tetracycline on entomopathogenic nematodes and their bacterial symbionts.}, journal = {Ecotoxicology (London, England)}, volume = {30}, number = {4}, pages = {705-710}, pmid = {33761023}, issn = {1573-3017}, mesh = {Animals ; Anti-Bacterial Agents/toxicity ; Bacteria ; Humans ; *Moths ; *Rhabditida ; Tetracyclines ; }, abstract = {Among the new contaminants relevant for environment, one of the most significant roles is played by pharmaceuticals like antibiotic products for either human or veterinary use. Their presence could cause serious damage to bacteria and microfauna, like nematodes. Within the widely investigated nematodes, very little is known about the interaction between antibiotics and entomopathogenic nematodes (EPN). EPNs have been used for biological control of crops, due to their ability to penetrate arthropod pests and kill their hosts thanks to a complex symbiotic mechanism with specific gram-negative bacteria. Tetracycline is an antibiotic used in human and veterinary medicine, both for therapeutic purposes and for the growth of livestock. Since its action against gram-negative bacteria is documented, we verified in this study the survival, growth and pathogenicity of two species of EPNs, Steinernema vulcanicum and S. feltiae. All tests were performed with tetracycline in 1% ethanol solution and up to 300 mg/L. Apparently, this incubation did not harm the vitality of EPNs. Both S. vulcanicum as S. feltiae recovered their vitality and entomopathogenic ability after 48 h. Moreover, the latter EPN species did not grow nor reproduce in the hemolymph of the Greater Wax Moth, Galleria mellonella, and their endosymbionts did not grow on MacConkey Agar. Our results suggest that the first EPN species has always retained all its abilities and that endosymbionts have acquired resistance to tetracycline, while experiments with the second EPN species provided some contrasting results in time that will require further investigations.}, }
@article {pmid33740894, year = {2021}, author = {Pyrih, J and Žárský, V and Fellows, JD and Grosche, C and Wloga, D and Striepen, B and Maier, UG and Tachezy, J}, title = {The iron-sulfur scaffold protein HCF101 unveils the complexity of organellar evolution in SAR, Haptista and Cryptista.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {46}, pmid = {33740894}, issn = {2730-7182}, mesh = {Animals ; *Cryptosporidiosis ; *Cryptosporidium ; Iron ; *Iron-Sulfur Proteins/genetics ; Phylogeny ; Sulfur ; }, abstract = {BACKGROUND: Nbp35-like proteins (Nbp35, Cfd1, HCF101, Ind1, and AbpC) are P-loop NTPases that serve as components of iron-sulfur cluster (FeS) assembly machineries. In eukaryotes, Ind1 is present in mitochondria, and its function is associated with the assembly of FeS clusters in subunits of respiratory Complex I, Nbp35 and Cfd1 are the components of the cytosolic FeS assembly (CIA) pathway, and HCF101 is involved in FeS assembly of photosystem I in plastids of plants (chHCF101). The AbpC protein operates in Bacteria and Archaea. To date, the cellular distribution of these proteins is considered to be highly conserved with only a few exceptions.<br><br>RESULTS: We searched for the genes of all members of the Nbp35-like protein family and analyzed their targeting sequences. Nbp35 and Cfd1 were predicted to reside in the cytoplasm with some exceptions of Nbp35 localization to the mitochondria; Ind1was found in the mitochondria, and HCF101 was predicted to reside in plastids (chHCF101) of all photosynthetically active eukaryotes. Surprisingly, we found a second HCF101 paralog in all members of Cryptista, Haptista, and SAR that was predicted to predominantly target mitochondria (mHCF101), whereas Ind1 appeared to be absent in these organisms. We also identified a few exceptions, as apicomplexans possess mHCF101 predicted to localize in the cytosol and Nbp35 in the mitochondria. Our predictions were experimentally confirmed in selected representatives of Apicomplexa (Toxoplasma gondii), Stramenopila (Phaeodactylum tricornutum, Thalassiosira pseudonana), and Ciliophora (Tetrahymena thermophila) by tagging proteins with a transgenic reporter. Phylogenetic analysis suggested that chHCF101 and mHCF101 evolved from a common ancestral HCF101 independently of the Nbp35/Cfd1 and Ind1 proteins. Interestingly, phylogenetic analysis supports rather a lateral gene transfer of ancestral HCF101 from bacteria than its acquisition being associated with either &#x3b1;-proteobacterial or cyanobacterial endosymbionts.<br><br>CONCLUSION: Our searches for Nbp35-like proteins across eukaryotic lineages revealed that SAR, Haptista, and Cryptista possess mitochondrial HCF101. Because plastid localization of HCF101 was only known thus far, the discovery of its mitochondrial paralog explains confusion regarding the presence of HCF101 in organisms that possibly lost secondary plastids (e.g., ciliates, Cryptosporidium) or possess reduced nonphotosynthetic plastids (apicomplexans).}, }
@article {pmid33739376, year = {2021}, author = {Tria, FDK and Brueckner, J and Skejo, J and Xavier, JC and Kapust, N and Knopp, M and Wimmer, JLE and Nagies, FSP and Zimorski, V and Gould, SB and Garg, SG and Martin, WF}, title = {Gene Duplications Trace Mitochondria to the Onset of Eukaryote Complexity.}, journal = {Genome biology and evolution}, volume = {13}, number = {5}, pages = {}, pmid = {33739376}, issn = {1759-6653}, mesh = {*Biological Evolution ; Eukaryota/*genetics ; Evolution, Molecular ; *Gene Duplication ; Gene Transfer, Horizontal ; Genes, Archaeal ; Genes, Bacterial ; Mitochondria/*genetics ; }, abstract = {The last eukaryote common ancestor (LECA) possessed mitochondria and all key traits that make eukaryotic cells more complex than their prokaryotic ancestors, yet the timing of mitochondrial acquisition and the role of mitochondria in the origin of eukaryote complexity remain debated. Here, we report evidence from gene duplications in LECA indicating an early origin of mitochondria. Among 163,545 duplications in 24,571 gene trees spanning 150 sequenced eukaryotic genomes, we identify 713 gene duplication events that occurred in LECA. LECA's bacterial-derived genes include numerous mitochondrial functions and were duplicated significantly more often than archaeal-derived and eukaryote-specific genes. The surplus of bacterial-derived duplications in LECA most likely reflects the serial copying of genes from the mitochondrial endosymbiont to the archaeal host's chromosomes. Clustering, phylogenies and likelihood ratio tests for 22.4 million genes from 5,655 prokaryotic and 150 eukaryotic genomes reveal no evidence for lineage-specific gene acquisitions in eukaryotes, except from the plastid in the plant lineage. That finding, and the functions of bacterial genes duplicated in LECA, suggests that the bacterial genes in eukaryotes are acquisitions from the mitochondrion, followed by vertical gene evolution and differential loss across eukaryotic lineages, flanked by concomitant lateral gene transfer among prokaryotes. Overall, the data indicate that recurrent gene transfer via the copying of genes from a resident mitochondrial endosymbiont to archaeal host chromosomes preceded the onset of eukaryotic cellular complexity, favoring mitochondria-early over mitochondria-late hypotheses for eukaryote origin.}, }
@article {pmid33732075, year = {2021}, author = {Pachla, A and Ptaszyńska, AA and Wicha, M and Kunat, M and Wydrych, J and Oleńska, E and Małek, W}, title = {Insight into probiotic properties of lactic acid bacterial endosymbionts of Apis mellifera L. derived from the Polish apiary.}, journal = {Saudi journal of biological sciences}, volume = {28}, number = {3}, pages = {1890-1899}, pmid = {33732075}, issn = {1319-562X}, abstract = {Taking into account that fructophilic lactic acid bacteria (FLAB) can play an important role in the health of honey bees and can be used as probiotics, phenotypic properties of probiotic interest of Lactobacillus kunkeei (12 strains) and Fructobacillus fructossus bacteria (2 strains), isolated from Apis mellifera gastrointestinal tract, have been studied. We have evaluated survival of tested FLAB in honey bee gut, their susceptibility to antibiotics (ampicillin, erythromycin, tylosin), cell surface hydrophobicity, auto-aggregation ability, co-aggregation with model pathogenic bacteria, biofilm formation capacity, and effect of studied FLAB, added to sucrose syrup bee diet, on longevity of honey bees. The tested FLAB exhibited good gastrointestinal tract tolerance and high antibiotic susceptibility, which are important criteria in the screening of probiotic candidates. It was also found that all FLAB studied have high cell surface hydrophobicity and fulfil next selection criterion for their use as probiotics. Symbionts of A. mellifera showed also auto- and co-aggregation capacities regarded as valuable features for biofilm formation and inhibition of pathogens adhesion to the bee gut cells. Biofilm-development ability is a desired characteristic of probiotic lactic acid bacteria. As indicated by quantitative crystal violet-stained microplate assay and confocal laser scanning microscopy imaging, all studied A. mellifera gut isolates exhibit a biofilm positive phenotype. Moreover, it was also documented, on honey bees kept in cages, that supplementation of A. mellifera sucrose diet with FLAB decreases mortality and improves significantly longevity of honey bees. Presented research showed that A. mellifera FLAB symbionts are good candidates for application as probiotics.}, }
@article {pmid33731867, year = {2021}, author = {Otto, G}, title = {A new bacterial endosymbiont.}, journal = {Nature reviews. Microbiology}, volume = {19}, number = {5}, pages = {283}, pmid = {33731867}, issn = {1740-1534}, }
@article {pmid33730185, year = {2021}, author = {Arab, DA and Lo, N}, title = {Evolutionary Rates are Correlated Between Buchnera Endosymbionts and the Mitochondrial Genomes of Their Aphid Hosts.}, journal = {Journal of molecular evolution}, volume = {89}, number = {4-5}, pages = {238-248}, pmid = {33730185}, issn = {1432-1432}, mesh = {Animals ; *Aphids/genetics ; Bacteroidetes ; *Buchnera/genetics ; Evolution, Molecular ; *Genome, Mitochondrial/genetics ; Phylogeny ; }, abstract = {The evolution of bacterial endosymbiont genomes is strongly influenced by host-driven selection. Factors affecting host genome evolution will potentially affect endosymbiont genomes in similar ways. One potential outcome is correlations in molecular rates between the genomes of the symbiotic partners. Recently, we presented the first evidence of such correlations between the mitochondrial genomes of cockroaches and the genomes of their endosymbiont (Blattabacterium cuenoti). Here we investigate whether similar patterns are found in additional host-symbiont partners. We use partial genome data from multiple strains of the bacterial endosymbionts Buchnera aphidicola and Sulcia muelleri, and the mitochondrial genomes of their sap-feeding insect hosts. Both endosymbionts show phylogenetic congruence with the mitochondria of their hosts, a result that is expected due to their identical mode of inheritance. We compared root-to-tip distances and branch lengths of phylogenetically independent species pairs. Both analyses showed a highly significant correlation of molecular rates between the genomes of Buchnera and the mitochondrial genomes of their hosts. A similar correlation was detected between Sulcia and their hosts, but was not statistically significant. Our results indicate that evolutionary rate correlations between hosts and long-term symbionts may be a widespread phenomenon.}, }
@article {pmid33723272, year = {2021}, author = {Pröschold, T and Rieser, D and Darienko, T and Nachbaur, L and Kammerlander, B and Qian, K and Pitsch, G and Bruni, EP and Qu, Z and Forster, D and Rad-Menendez, C and Posch, T and Stoeck, T and Sonntag, B}, title = {An integrative approach sheds new light onto the systematics and ecology of the widespread ciliate genus Coleps (Ciliophora, Prostomatea).}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {5916}, pmid = {33723272}, issn = {2045-2322}, support = {I 2238/FWF_/Austrian Science Fund FWF/Austria ; P 28333/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Biodiversity ; Biological Variation, Population ; Ciliophora/*classification/cytology/*genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Ecology ; Ecosystem ; Lakes ; Nucleic Acid Conformation ; Phenotype ; Phylogeny ; Seasons ; Symbiosis ; Water/*parasitology ; }, abstract = {Species of the genus Coleps are one of the most common planktonic ciliates in lake ecosystems. The study aimed to identify the phenotypic plasticity and genetic variability of different Coleps isolates from various water bodies and from culture collections. We used an integrative approach to study the strains by (i) cultivation in a suitable culture medium, (ii) screening of the morphological variability including the presence/absence of algal endosymbionts of living cells by light microscopy, (iii) sequencing of the SSU and ITS rDNA including secondary structures, (iv) assessment of their seasonal and spatial occurrence in two lakes over a one-year cycle both from morphospecies counts and high-throughput sequencing (HTS), and, (v) proof of the co-occurrence of Coleps and their endosymbiotic algae from HTS-based network analyses in the two lakes. The Coleps strains showed a high phenotypic plasticity and low genetic variability. The algal endosymbiont in all studied strains was Micractinium conductrix and the mutualistic relationship turned out as facultative. Coleps is common in both lakes over the whole year in different depths and HTS has revealed that only one genotype respectively one species, C. viridis, was present in both lakes despite the different lifestyles (mixotrophic with green algal endosymbionts or heterotrophic without algae). Our results suggest a future revision of the species concept of the genus Coleps.}, }
@article {pmid33716790, year = {2021}, author = {Martins, M and Ramos, LFC and Murillo, JR and Torres, A and de Carvalho, SS and Domont, GB and de Oliveira, DMP and Mesquita, RD and Nogueira, FCS and Maciel-de-Freitas, R and Junqueira, M}, title = {Comprehensive Quantitative Proteome Analysis of Aedes aegypti Identifies Proteins and Pathways Involved in Wolbachia pipientis and Zika Virus Interference Phenomenon.}, journal = {Frontiers in physiology}, volume = {12}, number = {}, pages = {642237}, pmid = {33716790}, issn = {1664-042X}, abstract = {Zika virus (ZIKV) is a global public health emergency due to its association with microcephaly, Guillain-Barré syndrome, neuropathy, and myelitis in children and adults. A total of 87 countries have had evidence of autochthonous mosquito-borne transmission of ZIKV, distributed across four continents, and no antivirus therapy or vaccines are available. Therefore, several strategies have been developed to target the main mosquito vector, Aedes aegypti, to reduce the burden of different arboviruses. Among such strategies, the use of the maternally-inherited endosymbiont Wolbachia pipientis has been applied successfully to reduce virus susceptibility and decrease transmission. However, the mechanisms by which Wolbachia orchestrate resistance to ZIKV infection remain to be elucidated. In this study, we apply isobaric labeling quantitative mass spectrometry (MS)-based proteomics to quantify proteins and identify pathways altered during ZIKV infection; Wolbachia infection; co-infection with Wolbachia/ZIKV in the A. aegypti heads and salivary glands. We show that Wolbachia regulates proteins involved in reactive oxygen species production, regulates humoral immune response, and antioxidant production. The reduction of ZIKV polyprotein in the presence of Wolbachia in mosquitoes was determined by MS and corroborates the idea that Wolbachia helps to block ZIKV infections in A. aegypti. The present study offers a rich resource of data that may help to elucidate mechanisms by which Wolbachia orchestrate resistance to ZIKV infection in A. aegypti, and represents a step further on the development of new targeted methods to detect and quantify ZIKV and Wolbachia directly in complex tissues.}, }
@article {pmid33715441, year = {2021}, author = {Cornwell, BH and Hernández, L}, title = {Genetic structure in the endosymbiont Breviolum 'muscatinei' is correlated with geographical location, environment and host species.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1946}, pages = {20202896}, pmid = {33715441}, issn = {1471-2954}, support = {P30 CA093373/CA/NCI NIH HHS/United States ; S10 OD018223/OD/NIH HHS/United States ; }, mesh = {Animals ; *Anthozoa/genetics ; Coral Reefs ; *Dinoflagellida/genetics ; Ecosystem ; Genetic Structures ; *Sea Anemones ; Symbiosis ; }, abstract = {Corals and cnidarians form symbioses with dinoflagellates across a wide range of habitats from the tropics to temperate zones. Notably, these partnerships create the foundation of coral reef ecosystems and are at risk of breaking down due to climate change. This symbiosis couples the fitness of the partners, where adaptations in one species can benefit the holobiont. However, the scales over which each partner can match their current-and future-environment are largely unknown. We investigated population genetic patterns of temperate anemones (Anthopleura spp.) and their endosymbiont Breviolum 'muscatinei', across an extensive geographical range to identify the spatial scales over which local adaptation is possible. Similar to previously published results, two solitary host species exhibited isolation by distance across hundreds of kilometres. However, symbionts exhibited genetic structure across multiple spatial scales, from geographical location to depth in the intertidal zone, and host species, suggesting that symbiont populations are more likely than their hosts to adaptively mitigate the impact of increasing temperatures.}, }
@article {pmid33712703, year = {2021}, author = {Smee, MR and Raines, SA and Ferrari, J}, title = {Genetic identity and genotype × genotype interactions between symbionts outweigh species level effects in an insect microbiome.}, journal = {The ISME journal}, volume = {15}, number = {9}, pages = {2537-2546}, pmid = {33712703}, issn = {1751-7370}, support = {BB/J00524X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; *Aphids ; Genotype ; *Microbiota ; Pedigree ; Symbiosis ; }, abstract = {Microbial symbionts often alter the phenotype of their host. Benefits and costs to hosts depend on many factors, including host genotype, symbiont species and genotype, and environmental conditions. Here, we present a study demonstrating genotype-by-genotype (G×G) interactions between multiple species of endosymbionts harboured by an insect, and the first to quantify the relative importance of G×G interactions compared with species interactions in such systems. In the most extensive study to date, we microinjected all possible combinations of five Hamiltonella defensa and five Fukatsuia symbiotica (X-type; PAXS) isolates into the pea aphid, Acyrthosiphon pisum. We applied several ecological challenges: a parasitoid wasp, a fungal pathogen, heat shock, and performance on different host plants. Surprisingly, genetic identity and genotype × genotype interactions explained far more of the phenotypic variation (on average 22% and 31% respectively) than species identity or species interactions (on average 12% and 0.4%, respectively). We determined the costs and benefits associated with co-infection, and how these compared to corresponding single infections. All phenotypes were highly reliant on individual isolates or interactions between isolates of the co-infecting partners. Our findings highlight the importance of exploring the eco-evolutionary consequences of these highly specific interactions in communities of co-inherited species.}, }
@article {pmid33705534, year = {2021}, author = {Lim, SJ and Davis, B and Gill, D and Swetenburg, J and Anderson, LC and Engel, AS and Campbell, BJ}, title = {Gill microbiome structure and function in the chemosymbiotic coastal lucinid Stewartia floridana.}, journal = {FEMS microbiology ecology}, volume = {97}, number = {4}, pages = {}, doi = {10.1093/femsec/fiab042}, pmid = {33705534}, issn = {1574-6941}, mesh = {Animals ; Bacteria ; *Bivalvia ; Gills ; *Microbiota ; Phylogeny ; Symbiosis ; }, abstract = {Lucinid bivalves harbor environmentally acquired, chemosynthetic, gammaproteobacterial gill endosymbionts. Lucinid gill microbiomes, which may contain other gammaproteobacterial and/or spirochete taxa, remain under-sampled. To understand inter-host variability of the lucinid gill microbiome, specifically in the bacterial communities, we analyzed the microbiome content of Stewartia floridana collected from Florida. Sampled gills contained a monospecific gammaproteobacterial endosymbiont expressing lithoautotrophic, mixotrophic, diazotrophic and C1 compound oxidation-related functions previously characterized in similar lucinid species. Another low-abundance Spirochaeta-like species in ∼72% of the sampled gills was most closely related to Spirochaeta-like species in another lucinid Phacoides pectinatus and formed a clade with known marine Spirochaeta symbionts. The spirochete expressed genes were involved in heterotrophy and the transport of sugars, amino acids, peptides and other substrates. Few muscular and neurofilament genes from the host and none from the gammaproteobacterial and spirochete symbionts were differentially expressed among quadrats predominantly covered with seagrass species or 80% bare sand. Our results suggest that spirochetes are facultatively associated with S. floridana, with potential scavenging and nutrient cycling roles. Expressed stress- and defense-related functions in the host and symbionts also suggest species-species communications, which highlight the need for further study of the interactions among lucinid hosts, their microbiomes and their environment.}, }
@article {pmid33684989, year = {2021}, author = {Moon, EK and Park, SM and Chu, KB and Quan, FS and Kong, HH}, title = {Differentially Expressed Gene Profile of Acanthamoeba castellanii Induced by an Endosymbiont Legionella pneumophila.}, journal = {The Korean journal of parasitology}, volume = {59}, number = {1}, pages = {67-75}, pmid = {33684989}, issn = {1738-0006}, mesh = {Acanthamoeba castellanii/enzymology/*genetics/*microbiology ; Acetyltransferases/genetics/metabolism ; Catalysis ; Gene Ontology ; Genes, Protozoan/*genetics ; Hydrolases/metabolism ; Legionella pneumophila/pathogenicity/*physiology ; Methyltransferases/genetics/metabolism ; Oxidoreductases/metabolism ; Sequence Analysis, RNA ; Symbiosis/*genetics ; Transcription, Genetic ; Transcriptome/*genetics ; }, abstract = {Legionella pneumophila is an opportunistic pathogen that survives and proliferates within protists such as Acanthamoeba spp. in environment. However, intracellular pathogenic endosymbiosis and its implications within Acanthamoeba spp. remain poorly understood. In this study, RNA sequencing analysis was used to investigate transcriptional changes in A. castellanii in response to L. pneumophila infection. Based on RNA sequencing data, we identified 1,211 upregulated genes and 1,131 downregulated genes in A. castellanii infected with L. pneumophila for 12 hr. After 24 hr, 1,321 upregulated genes and 1,379 downregulated genes were identified. Gene ontology (GO) analysis revealed that L. pneumophila endosymbiosis enhanced hydrolase activity, catalytic activity, and DNA binding while reducing oxidoreductase activity in the molecular function (MF) domain. In particular, multiple genes associated with the GO term 'integral component of membrane' were downregulated during endosymbiosis. The endosymbiont also induced differential expression of various methyltransferases and acetyltransferases in A. castellanii. Findings herein are may significantly contribute to understanding endosymbiosis of L. pneumophila within A. castellanii.}, }
@article {pmid33669045, year = {2021}, author = {Wang, YJ and Li, SC and Lin, WC and Huang, FC}, title = {Intracellular Microbiome Profiling of the Acanthamoeba Clinical Isolates from Lens Associated Keratitis.}, journal = {Pathogens (Basel, Switzerland)}, volume = {10}, number = {3}, pages = {}, pmid = {33669045}, issn = {2076-0817}, abstract = {Acanthamoeba act as hosts for various microorganisms and pathogens, causing Acanthamoeba Keratitis (AK). To investigate the association between endosymbionts and AK progression, we performed a metagenomics study to characterize the intracellular microbiome from five lenses associated with AK isolates and standard strains to characterize the role of ocular flora in AK progression. The used clinical isolates were axenic cultured from lenses associated with AK patients. AK isolates and standard controls such as 16S ribosomal RNA sequencing techniques were used for analysis. The microbiome compositions and relative abundance values were compared. The orders of Clostridiales and Bacteroidales presented major populations of intracellular microbes belonging to all isolates. Comparison of the different source isolates showed that most of the abundance in keratitis isolates came from Ruminococcus gnavus (121.0 folds), Eubacterium dolichum (54.15 folds), Roseburia faecis (24.51 folds), and Blautia producta (3.15 folds). Further analysis of the relative abundance data from keratitis isolates showed that Blautia producta was positively correlated with the disease course. In contrast, Bacteroides ovatus was found to be abundant in early-stage keratitis isolates. This study reveals the abundant anaerobic Gram-positive rods present in severe keratitis isolate and characterize the association between Acanthamoeba and ocular flora in AK progression.}, }
@article {pmid33664278, year = {2021}, author = {Ma, YJ and He, HP and Zhao, HM and Xian, YD and Guo, H and Liu, B and Xue, K}, title = {Microbiome diversity of cotton aphids (Aphis gossypii) is associated with host alternation.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {5260}, pmid = {33664278}, issn = {2045-2322}, mesh = {Animals ; Aphids/genetics/*microbiology ; Genetic Variation/*genetics ; Gossypium/genetics/microbiology ; High-Throughput Nucleotide Sequencing ; Host-Pathogen Interactions/*genetics ; Microbiota/*genetics ; Symbiosis/genetics ; }, abstract = {Aphids are infected by a series of bacteria that can help them survive on specific host plants. However, the associations between aphids and these bacteria are not clear, and the bacterial communities in many aphid species are poorly characterized. Here, we investigated the bacterial communities of cotton aphids (Aphis gossypii) on 2 representative winter host plants and transferred to 3 summer host plants by 16S rDNA sequencing using the Illumina MiSeq platform. Our results revealed that the bacterial communities varied among cotton aphids on hibiscus, cotton aphids on pomegranate, cotton aphids on cotton transferred from hibiscus, cotton aphids on muskmelon transferred from hibiscus, cotton aphids on cucumber transferred from hibiscus,. The diversity and richness of the bacterial communities were significantly higher in aphids on muskmelon and aphids on cucumber than in the other treatments. There were two main factors influencing the distribution of internal bacterial OTUs revealed by principal component analysis, including the differences among Punicaceae, Malvaceae and Cucurbitaceae. There were 28 bacterial communities with significant differences between two arbitrary treatments, which could be grouped into 6 main clusters depending on relative abundance. Moreover, our results indicated that in addition to the obligate endosymbiont Buchnera, with a dominant position (> 52%), A. gossypii also harbored 3 facultative endosymbiotic bacteria (Serratia, Arsenophonus, and Wolbachia) and 3 possibly symbiotic bacteria (Acinetobacter, Pantoea, and Flavobacterium). There were several correspondences between the symbiotic bacteria in cotton aphids and the specific host plants of the aphids. This study provides a better understanding of the interactions among symbiotic bacteria, aphids and host plants, suggesting that the selection pressure on aphid bacterial communities is likely to be exerted by the species of host plants.}, }
@article {pmid33659853, year = {2020}, author = {Romanov, DA and Zakharov, IA and Shaikevich, EV}, title = {Wolbachia, Spiroplasma, and Rickettsia symbiotic bacteria in aphids (Aphidoidea).}, journal = {Vavilovskii zhurnal genetiki i selektsii}, volume = {24}, number = {6}, pages = {673-682}, doi = {10.18699/VJ20.661}, pmid = {33659853}, issn = {2500-0462}, abstract = {Aphids are a diverse family of crop pests. Aphids formed a complex relationship with intracellular bacteria. Depending on the region of study, the species composition of both aphids and their facultative endosymbionts varies. The aim of the work was to determine the occurrence and genetic diversity of Wolbachia, Spiroplasma and Rickettsia symbionts in aphids collected in 2018-2019 in Moscow. For these purposes, 578 aphids from 32 collection sites were tested by PCR using specific primers. At least 21 species of aphids from 14 genera and four families were identified by barcoding method, of which 11 species were infected with endosymbionts. Rickettsia was found in six species, Wolbachia in two species, Spiroplasma in one species. The presence of Rickettsia in Impatientinum asiaticum, Myzus cerasi, Hyalopterus pruni, Eucallipterus tiliae, Chaitophorus tremulae and Wolbachia in Aphis pomi and C. tremulae has been described for the first time. A double infection with Rickettsia and Spiroplasma was detected in a half of pea aphid (Acyrthosiphon pisum) individuals. For the first time was found that six species of aphids are infected with Rickettsia that are genetically different from previously known. It was first discovered that A. pomi is infected with two Wolbachia strains, one of which belongs to supergroup B and is genetically close to Wolbachia from C. tremulae. The second Wolbachia strain from A. pomi belongs to the supergroup M, recently described in aphid species. Spiroplasma, which we observed in A. pisum, is genetically close to male killing Spiroplasma from aphids, ladybirds and moths. Both maternal inheritance and horizontal transmission are the pathways for the distribution of facultative endosymbiotic bacteria in aphids.}, }
@article {pmid33658719, year = {2021}, author = {Graf, JS and Schorn, S and Kitzinger, K and Ahmerkamp, S and Woehle, C and Huettel, B and Schubert, CJ and Kuypers, MMM and Milucka, J}, title = {Anaerobic endosymbiont generates energy for ciliate host by denitrification.}, journal = {Nature}, volume = {591}, number = {7850}, pages = {445-450}, pmid = {33658719}, issn = {1476-4687}, mesh = {Adenosine Triphosphate/metabolism ; *Anaerobiosis ; Bacteria/genetics/*metabolism ; Biological Evolution ; Cell Respiration ; Ciliophora/chemistry/cytology/*metabolism ; Citric Acid Cycle/genetics ; *Denitrification ; Electron Transport/genetics ; *Energy Metabolism ; Genome, Bacterial/genetics ; *Host Microbial Interactions/genetics ; Mitochondria ; Nitrates/metabolism ; Oxygen/metabolism ; Phylogeny ; *Symbiosis ; }, abstract = {Mitochondria are specialized eukaryotic organelles that have a dedicated function in oxygen respiration and energy production. They evolved about 2 billion years ago from a free-living bacterial ancestor (probably an alphaproteobacterium), in a process known as endosymbiosis[1,2]. Many unicellular eukaryotes have since adapted to life in anoxic habitats and their mitochondria have undergone further reductive evolution[3]. As a result, obligate anaerobic eukaryotes with mitochondrial remnants derive their energy mostly from fermentation[4]. Here we describe 'Candidatus Azoamicus ciliaticola', which is an obligate endosymbiont of an anaerobic ciliate and has a dedicated role in respiration and providing energy for its eukaryotic host. 'Candidatus A. ciliaticola' contains a highly reduced 0.29-Mb genome that encodes core genes for central information processing, the electron transport chain, a truncated tricarboxylic acid cycle, ATP generation and iron-sulfur cluster biosynthesis. The genome encodes a respiratory denitrification pathway instead of aerobic terminal oxidases, which enables its host to breathe nitrate instead of oxygen. 'Candidatus A. ciliaticola' and its ciliate host represent an example of a symbiosis that is based on the transfer of energy in the form of ATP, rather than nutrition. This discovery raises the possibility that eukaryotes with mitochondrial remnants may secondarily acquire energy-providing endosymbionts to complement or replace functions of their mitochondria.}, }
@article {pmid33650119, year = {2021}, author = {Zhou, Z and Zhang, K and Wang, L and Su, Y and Wang, J and Song, T and Yang, X and Tang, J and Lin, S}, title = {Nitrogen availability improves the physiological resilience of coral endosymbiont Cladocopium goreaui to high temperature.}, journal = {Journal of phycology}, volume = {57}, number = {4}, pages = {1187-1198}, doi = {10.1111/jpy.13156}, pmid = {33650119}, issn = {1529-8817}, mesh = {Animals ; *Anthozoa ; *Dinoflagellida ; Nitrogen ; Symbiosis ; Temperature ; }, abstract = {The physiological response of symbiotic Symbiodiniaceae to high temperature is believed to result in coral bleaching. However, the potential effect of nitrogen availability on heat acclimatization of symbiotic Symbiodiniaceae is still unclear. In this study, physiological responses of Symbiodiniaceae Cladocopium goreaui to temperature and nitrogen nutrient stress conditions were investigated. Nitrogen deficiency caused significant declines in cell concentration and chlorophyll content per cell, but significant increases in nitric oxide synthase activity, caspase3 activation level, and cellular carbon content of C. goreaui at normal temperature. Algal cells under high temperature and nitrogen deficiency showed significant rises in Fv/Fm, catalase activity, and caspase3 activation level, but no significant changes in cell yield, cell size, chlorophyll content, superoxide dismutase, nitric oxide synthase activity, and cellular contents of nitrogen and carbon, in comparison with those under normal temperature and nitrogen deficiency. Growth, chlorophyll, and nitrogen contents of algal cells under the high temperature and nitrogen-replete conditions were significantly higher than those under high temperature or nitrogen deficiency alone, whereas nitric oxide synthase activity, superoxide dismutase activity, catalase activity, carbon content, and caspase3 activation level exhibited opposite trends of variation. Transcriptomic and network analyses revealed ion transport and metabolic processes mainly involved in regulating these physiological activities under different temperature and nitrogen nutrient. The totality of results shows that high temperature activates stress responses, induces antioxidant capacity of apoptosis, and limits the growth rate of C. goreaui. Adequate nitrogen nutrient can improve the resilience of this Symbiodiniaceae against heat stress through repressed apoptosis, promoted ion transport, and optimized metabolism.}, }
@article {pmid33646482, year = {2021}, author = {Olivieri, E and Kariuki, E and Floriano, AM and Castelli, M and Tafesse, YM and Magoga, G and Kumsa, B and Montagna, M and Sassera, D}, title = {Multi-country investigation of the diversity and associated microorganisms isolated from tick species from domestic animals, wildlife and vegetation in selected african countries.}, journal = {Experimental &amp; applied acarology}, volume = {83}, number = {3}, pages = {427-448}, pmid = {33646482}, issn = {1572-9702}, mesh = {Africa ; Animals ; Animals, Domestic ; Animals, Wild ; Egypt/epidemiology ; *Rickettsia ; *Tick-Borne Diseases/epidemiology/veterinary ; }, abstract = {In many areas of Africa, recent studies highlighted the great impact of ticks on animal and human health throughout the continent. On the other hand, very limited information on the bacterial endosymbionts of the African ticks and their pattern of co-infections with other bacteria are found in literature, notwithstanding their pivotal role in tick survival and vector efficiency. Thus, we investigated the distribution of selected pathogenic and symbiotic bacteria in hard ticks collected from wild, domestic animals and from vegetation in various ecological zones in Africa and their co-occurrence in the same tick host. Overall, 339 hard ticks were morphologically identified as belonging to the genera Amblyomma, Dermacentor, Hyalomma, Haemaphysalis, Ixodes and Rhipicephalus. Molecular screening provided information on pathogens circulation in Africa, detecting spotted fever group rickettsiae, Anaplasma spp., Ehrlichia ruminantium, Borrelia garinii, Babesia spp., Theileria spp. and Coxiella burnetii. Furthermore, our work provides insights on the African scenario of tick-symbiont associations, revealing the presence of Coxiella, Francisella and Midichloria across multiple tick populations. Coxiella endosymbionts were the most prevalent microorganisms, and that with the broadest spectrum of hosts, being detected in 16 tick species. Francisella was highly prevalent among the Hyalomma species tested and correlated negatively with the presence of Coxiella, showing a potential competitive interaction. Interestingly, we detected a positive association of Francisella with Rickettsia in specimens of Hy. rufipes, suggesting a synergistic interaction between them. Finally, Midichloria was the most prevalent symbiont in Rhipicephalus sanguineus sensu lato from Egypt.}, }
@article {pmid33634321, year = {2021}, author = {Teoh, MC and Furusawa, G and Veera Singham, G}, title = {Multifaceted interactions between the pseudomonads and insects: mechanisms and prospects.}, journal = {Archives of microbiology}, volume = {203}, number = {5}, pages = {1891-1915}, pmid = {33634321}, issn = {1432-072X}, mesh = {Animals ; Biological Control Agents ; Host-Pathogen Interactions ; Insect Vectors/classification/microbiology ; Insecta/classification/*microbiology ; Pseudomonas/metabolism/*physiology ; Symbiosis ; Virulence Factors/metabolism ; }, abstract = {Insects and bacteria are the most widespread groups of organisms found in nearly all habitats on earth, establishing diverse interactions that encompass the entire range of possible symbiotic associations from strict parasitism to obligate mutualism. The complexity of their interactions is instrumental in shaping the roles of insects in the environment, meanwhile ensuring the survival and persistence of the associated bacteria. This review aims to provide detailed insight on the multifaceted symbiosis between one of the most versatile bacterial genera, Pseudomonas (Gammaproteobacteria: Pseudomonadaceae) and a diverse group of insect species. The Pseudomonas engages with varied interactions with insects, being either a pathogen or beneficial endosymbiont, as well as using insects as vectors. In addition, this review also provides updates on existing and potential applications of Pseudomonas and their numerous insecticidal metabolites as biocontrol agents against pest insects for the improvement of integrated pest management strategies. Here, we have summarized several known modes of action and the virulence factors of entomopathogenic Pseudomonas strains essential for their pathogenicity against insects. Meanwhile, the beneficial interactions between pseudomonads and insects are currently limited to a few known insect taxa, despite numerous studies reporting identification of pseudomonads in the guts and haemocoel of various insect species. The vector-symbiont association between pseudomonads and insects can be diverse from strict phoresy to a role switch from commensalism to parasitism following a dose-dependent response. Overall, the pseudomonads appeared to have evolved independently to be either exclusively pathogenic or beneficial towards insects.}, }
@article {pmid33627171, year = {2021}, author = {Bulman, CA and Chappell, L and Gunderson, E and Vogel, I and Beerntsen, B and Slatko, BE and Sullivan, W and Sakanari, JA}, title = {The Eagle effect in the Wolbachia-worm symbiosis.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {118}, pmid = {33627171}, issn = {1756-3305}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Brugia malayi/drug effects/microbiology/*physiology ; Doxycycline/pharmacology ; Female ; Male ; Microfilariae/drug effects/*microbiology/physiology ; Onchocerca/drug effects/microbiology/*physiology ; *Symbiosis/drug effects ; Wolbachia/drug effects/*physiology ; }, abstract = {BACKGROUND: Onchocerciasis (river blindness) and lymphatic filariasis (elephantiasis) are two human neglected tropical diseases that cause major disabilities. Mass administration of drugs targeting the microfilarial stage has reduced transmission and eliminated these diseases in several countries but a macrofilaricidal drug that kills or sterilizes the adult worms is critically needed to eradicate the diseases. The causative agents of onchocerciasis and lymphatic filariasis are filarial worms that harbor the endosymbiotic bacterium Wolbachia. Because filarial worms depend on Wolbachia for reproduction and survival, drugs targeting Wolbachia hold great promise as a means to eliminate these diseases.<br><br>METHODS: To better understand the relationship between Wolbachia and its worm host, adult&#xa0;Brugia pahangi&#xa0;were exposed to varying concentrations of doxycycline, minocycline, tetracycline and rifampicin&#xa0;in vitro&#xa0;and assessed for Wolbachia numbers and worm motility. Worm motility was monitored using the Worminator system, and Wolbachia titers were assessed by qPCR of the single copy gene wsp from Wolbachia and gst from Brugia to calculate IC50s and in time course experiments. Confocal microscopy was also used to quantify Wolbachia located at the distal tip region of worm ovaries to assess the effects of antibiotic treatment in this region of the worm where Wolbachia are transmitted vertically to the microfilarial stage.<br><br>RESULTS: Worms treated with higher concentrations of antibiotics had higher Wolbachia titers, i.e. as antibiotic concentrations increased there was a corresponding increase in Wolbachia titers. As the concentration of antibiotic increased, worms stopped moving and never recovered despite maintaining Wolbachia titers comparable to controls. Thus, worms were rendered moribund by the higher concentrations of antibiotics but Wolbachia persisted suggesting that these antibiotics may act directly on the worms at high concentration. Surprisingly, in contrast to these results, antibiotics given at low concentrations reduced Wolbachia titers.<br><br>CONCLUSION: Wolbachia in B. pahangi display a counterintuitive dose response known as the "Eagle effect." This effect in Wolbachia suggests a common underlying mechanism that allows diverse bacterial and fungal species to persist despite exposure to high concentrations of antimicrobial compounds. To our knowledge this is the first report of this phenomenon occurring in an intracellular endosymbiont, Wolbachia, in its filarial host.}, }
@article {pmid33624756, year = {2021}, author = {Baniya, A and DiGennaro, P}, title = {Genome announcement of Steinernema khuongi and its associated symbiont from Florida.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {4}, pages = {}, pmid = {33624756}, issn = {2160-1836}, mesh = {Animals ; Florida ; *Rhabditida ; Symbiosis ; *Xenorhabdus ; }, abstract = {Citrus root weevil (Diaprepes abbreviates) causes significant yield loss in citrus, especially in Florida. A promising source of control for this pest is biological control agents, namely, native entomopathogenic nematodes (EPNs) within the genus Steinernema. Two species of endemic EPN in Florida are S. diaparepesi, abundant within the central ridge, and S. khuongi, dominating the flatwood regions of the state. These citrus-growing regions differ significantly in their soil habitats, which impacts the potential success of biological control measures. Although the genome sequence of S. diaprepesi is currently available, the genome sequence of S. khuongi and identity of the symbiotic bacteria is still unknown. Understanding the genomic differences between these two nematodes and their favored habitats can inform successful biological control practices. Here, MiSeq libraries were used to simultaneously sequence and assemble the draft genome of S. khuongi and its associated symbionts. The final draft genome for S. khuongi has 8,794 contigs with a total length of ∼82 Mb, a largest contig of 428,226 bp, and N50 of 46 kb; its BUSCO scores indicate that it is > 86% complete. An associated bacterial genome was assembled with a total length of ∼3.5 Mb, a largest contig at 116,532 bp, and N50 of 17,487 bp. The bacterial genome encoded 3,721 genes, similar to other Xenorhabdus genomes. Comparative genomics identified the symbiotic bacteria of S. khuongi as Xenorhabdus poinarii. These new draft genomes of a host and symbiont can be used as a valuable tool for comparative genomics with other EPNs and its symbionts to understand host range and habitat suitability.}, }
@article {pmid33620311, year = {2021}, author = {Wang, XQ and Guo, JS and Li, DT and Yu, Y and Hagoort, J and Moussian, B and Zhang, CX}, title = {Three-dimensional reconstruction of a whole insect reveals its phloem sap-sucking mechanism at nano-resolution.}, journal = {eLife}, volume = {10}, number = {}, pages = {}, pmid = {33620311}, issn = {2050-084X}, mesh = {Animals ; Feeding Behavior ; Female ; Hemiptera/growth &amp; development/*ultrastructure ; *Imaging, Three-Dimensional ; Microscopy, Electron, Scanning ; Mouth/ultrastructure ; Nymph/growth &amp; development/ultrastructure ; Phloem ; }, abstract = {Using serial block-face scanning electron microscopy, we report on the internal 3D structures of the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae) at nanometer resolution for the first time. Within the reconstructed organs and tissues, we found many novel and fascinating internal structures in the planthopper such as naturally occurring three four-way rings connecting adjacent spiracles to facilitate efficient gas exchange, and fungal endosymbionts in a single huge insect cell occupying 22% of the abdomen volume to enable the insect to live on plant sap. To understand the muscle and stylet movement during phloem sap-sucking, the cephalic skeleton and muscles were reconstructed in feeding nymphs. The results revealed an unexpected contraction of the protractors of the stylets and suggested a novel feeding model for the phloem sap-sucking.}, }
@article {pmid33610188, year = {2021}, author = {Guo, H and Wang, N and Niu, H and Zhao, D and Zhang, Z}, title = {Interaction of Arsenophonus with Wolbachia in Nilaparvata lugens.}, journal = {BMC ecology and evolution}, volume = {21}, number = {1}, pages = {31}, pmid = {33610188}, issn = {2730-7182}, mesh = {Animals ; China/epidemiology ; *Hemiptera ; Humans ; *Spiroplasma ; Symbiosis ; *Wolbachia ; }, abstract = {BACKGROUND: Co-infection of endosymbionts in the same host is ubiquitous, and the interactions of the most common symbiont Wolbachia with other symbionts, including Spiroplasma, in invertebrate organisms have received increasing attention. However, the interactions between Wolbachia and Arsenophonus, another widely distributed symbiont in nature, are poorly understood. We tested the co-infection of Wolbachia and Arsenophonus in different populations of Nilaparvata lugens and investigated whether co-infection affected the population size of the symbionts in their host.<br><br>RESULTS: A significant difference was observed in the co-infection incidence of Wolbachia and Arsenophonus among 5 populations of N. lugens from China, with nearly half of the individuals in the Zhenjiang population harbouring the two symbionts simultaneously, and the rate of occurrence was significantly higher than that of the other 4 populations. The Arsenophonus density in the superinfection line was significantly higher only in the Maanshan population compared with that of the single-infection line. Differences in the density of Wolbachia and Arsenophonus were found in all the tested double-infection lines, and the dominant symbiont species varied with the population only in the Nanjing population, with Arsenophonus the overall dominant symbiont.<br><br>CONCLUSIONS: Wolbachia and Arsenophonus could coexist in N. lugens, and the co-infection incidence varied with the geographic populations. Antagonistic interactions were not observed between Arsenophonus and Wolbachia, and the latter was the dominant symbiont in most populations.}, }
@article {pmid33608555, year = {2021}, author = {Lan, Y and Sun, J and Chen, C and Sun, Y and Zhou, Y and Yang, Y and Zhang, W and Li, R and Zhou, K and Wong, WC and Kwan, YH and Cheng, A and Bougouffa, S and Van Dover, CL and Qiu, JW and Qian, PY}, title = {Hologenome analysis reveals dual symbiosis in the deep-sea hydrothermal vent snail Gigantopelta aegis.}, journal = {Nature communications}, volume = {12}, number = {1}, pages = {1165}, pmid = {33608555}, issn = {2041-1723}, mesh = {Animals ; Bacteria/*genetics/metabolism ; Gammaproteobacteria/genetics/metabolism ; Gene Expression ; Genome, Bacterial ; Genomics ; Hydrothermal Vents/*microbiology ; Phylogeny ; Snails/*genetics/metabolism/*microbiology ; Sulfur/metabolism ; Symbiosis/*genetics/physiology ; Transcriptome ; }, abstract = {Animals endemic to deep-sea hydrothermal vents often form obligatory symbioses with bacteria, maintained by intricate host-symbiont interactions. Most genomic studies on holobionts have not investigated both sides to similar depths. Here, we report dual symbiosis in the peltospirid snail Gigantopelta aegis with two gammaproteobacterial endosymbionts: a sulfur oxidiser and a methane oxidiser. We assemble high-quality genomes for all three parties, including a chromosome-level host genome. Hologenomic analyses reveal mutualism with nutritional complementarity and metabolic co-dependency, highly versatile in transporting and using chemical energy. Gigantopelta aegis likely remodels its immune system to facilitate dual symbiosis. Comparisons with Chrysomallon squamiferum, a confamilial snail with a single sulfur-oxidising gammaproteobacterial endosymbiont, show that their sulfur-oxidising endosymbionts are phylogenetically distant. This is consistent with previous findings that they evolved endosymbiosis convergently. Notably, the two sulfur-oxidisers share the same capabilities in biosynthesising nutrients lacking in the host genomes, potentially a key criterion in symbiont selection.}, }
@article {pmid33600263, year = {2021}, author = {Snellgrove, AN and Krapiunaya, I and Scott, P and Levin, ML}, title = {Assessment of the Pathogenicity of Rickettsia amblyommatis, Rickettsia bellii, and Rickettsia montanensis in a Guinea Pig Model.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {21}, number = {4}, pages = {232-241}, pmid = {33600263}, issn = {1557-7759}, support = {CC999999/ImCDC/Intramural CDC HHS/United States ; /CC/CDC HHS/United States ; }, mesh = {Animals ; Guinea Pigs ; Male ; *Rickettsia/genetics ; *Ticks ; Virulence ; }, abstract = {Members of the genus Rickettsia range from nonpathogenic endosymbionts to virulent pathogens such as Rickettsia rickettsii, the causative agent of Rocky Mountain spotted fever. Many rickettsiae are considered nonpathogenic because they have been isolated from ticks but not vertebrate hosts. We assessed the ability of three presumed endosymbionts: Rickettsia amblyommatis, Rickettsia bellii, and Rickettsia montanensis, to infect a guinea pig animal model. These species were chosen because of their high prevalence in respective tick vectors or published reports suggestive of human or animal pathogenicity. Following intraperitoneal (IP) inoculation of cell culture suspensions of R. rickettsii, R. amblyommatis, R. bellii, or R. montanensis into guinea pigs, animals were monitored for signs of clinical illness for 13 days. Ear biopsies and blood samples were taken at 2- to 3-day intervals for detection of rickettsial DNA by PCR. Animals were necropsied and internal organ samples were also tested using PCR assays. Among the six guinea pigs inoculated with R. amblyommatis, fever, orchitis, and dermatitis were observed in one, one, and three animals respectively. In R. bellii-exposed animals, we noted fever in one of six animals, orchitis in one, and dermatitis in two. No PCR-positive tissues were present in either the R. amblyommatis- or R. bellii-exposed groups. In the R. montanensis-exposed group, two of six animals became febrile, two had orchitis, and three developed dermatitis in ears or footpads. R. montanensis DNA was detected in ear skin biopsies collected on multiple days from three animals. Also, a liver specimen from one animal and spleen specimens of two animals were PCR positive. The course and severity of disease in the three experimental groups were significantly milder than that of R. rickettsii. This study suggests that the three rickettsiae considered nonpathogenic can cause either subclinical or mild infections in guinea pigs when introduced via IP inoculation.}, }
@article {pmid33597173, year = {2021}, author = {Keller, CM and Kendra, CG and Bruna, RE and Craft, D and Pontes, MH}, title = {Genetic Modification of Sodalis Species by DNA Transduction.}, journal = {mSphere}, volume = {6}, number = {1}, pages = {}, pmid = {33597173}, issn = {2379-5042}, support = {R21 AI148774/AI/NIAID NIH HHS/United States ; }, mesh = {Bacteriophages/genetics/metabolism ; DNA, Bacterial/*genetics ; Enterobacteriaceae/classification/*genetics/*virology ; Escherichia coli/genetics ; *Gene Transfer Techniques ; *Genome, Bacterial ; Host Specificity ; Phylogeny ; Symbiosis ; *Transduction, Genetic ; }, abstract = {Bacteriophages (phages) are ubiquitous in nature. These viruses play a number of central roles in microbial ecology and evolution by, for instance, promoting horizontal gene transfer (HGT) among bacterial species. The ability of phages to mediate HGT through transduction has been widely exploited as an experimental tool for the genetic study of bacteria. As such, bacteriophage P1 represents a prototypical generalized transducing phage with a broad host range that has been extensively employed in the genetic manipulation of Escherichia coli and a number of other model bacterial species. Here we demonstrate that P1 is capable of infecting, lysogenizing, and promoting transduction in members of the bacterial genus Sodalis, including the maternally inherited insect endosymbiont Sodalis glossinidius While establishing new tools for the genetic study of these bacterial species, our results suggest that P1 may be used to deliver DNA to many Gram-negative endosymbionts in their insect host, thereby circumventing a culturing requirement to genetically manipulate these organisms.IMPORTANCE A large number of economically important insects maintain intimate associations with maternally inherited endosymbiotic bacteria. Due to the inherent nature of these associations, insect endosymbionts cannot be usually isolated in pure culture or genetically manipulated. Here we use a broad-host-range bacteriophage to deliver exogenous DNA to an insect endosymbiont and a closely related free-living species. Our results suggest that broad-host-range bacteriophages can be used to genetically alter insect endosymbionts in their insect host and, as a result, bypass a culturing requirement to genetically alter these bacteria.}, }
@article {pmid33591248, year = {2021}, author = {Gerth, M and Martinez-Montoya, H and Ramirez, P and Masson, F and Griffin, JS and Aramayo, R and Siozios, S and Lemaitre, B and Mateos, M and Hurst, GDD}, title = {Rapid molecular evolution of Spiroplasma symbionts of Drosophila.}, journal = {Microbial genomics}, volume = {7}, number = {2}, pages = {}, pmid = {33591248}, issn = {2057-5858}, mesh = {Amino Acid Substitution ; Animals ; Bacterial Proteins/genetics ; Drosophila/*microbiology ; Evolution, Molecular ; MutL Proteins/*genetics ; MutS Proteins/*genetics ; Mutation Rate ; Phylogeny ; Sequence Analysis, DNA ; Spiroplasma/*classification/genetics ; Symbiosis ; }, abstract = {Spiroplasma is a genus of Mollicutes whose members include plant pathogens, insect pathogens and endosymbionts of animals. Spiroplasma phenotypes have been repeatedly observed to be spontaneously lost in Drosophila cultures, and several studies have documented a high genomic turnover in Spiroplasma symbionts and plant pathogens. These observations suggest that Spiroplasma evolves quickly in comparison to other insect symbionts. Here, we systematically assess evolutionary rates and patterns of Spiroplasma poulsonii, a natural symbiont of Drosophila. We analysed genomic evolution of sHy within flies, and sMel within in vitro culture over several years. We observed that S. poulsonii substitution rates are among the highest reported for any bacteria, and around two orders of magnitude higher compared with other inherited arthropod endosymbionts. The absence of mismatch repair loci mutS and mutL is conserved across Spiroplasma, and likely contributes to elevated substitution rates. Further, the closely related strains sMel and sHy (>99.5 % sequence identity in shared loci) show extensive structural genomic differences, which potentially indicates a higher degree of host adaptation in sHy, a protective symbiont of Drosophila hydei. Finally, comparison across diverse Spiroplasma lineages confirms previous reports of dynamic evolution of toxins, and identifies loci similar to the male-killing toxin Spaid in several Spiroplasma lineages and other endosymbionts. Overall, our results highlight the peculiar nature of Spiroplasma genome evolution, which may explain unusual features of its evolutionary ecology.}, }
@article {pmid33590884, year = {2021}, author = {Larsen, T and Jefferson, C and Bartley, A and Strassmann, JE and Queller, DC}, title = {Inference of symbiotic adaptations in nature using experimental evolution.}, journal = {Evolution; international journal of organic evolution}, volume = {75}, number = {4}, pages = {945-955}, doi = {10.1111/evo.14193}, pmid = {33590884}, issn = {1558-5646}, mesh = {*Adaptation, Physiological ; Burkholderiaceae/*genetics/pathogenicity ; Dictyostelium/*genetics/microbiology ; *Directed Molecular Evolution ; *Symbiosis ; Virulence ; }, abstract = {Microbes must adapt to the presence of other species, but it can be difficult to recreate the natural context for these interactions in the laboratory. We describe a method for inferring the existence of symbiotic adaptations by experimentally evolving microbes that would normally interact in an artificial environment without access to other species. By looking for changes in the fitness effects microbes adapted to isolation have on their partners, we can infer the existence of ancestral adaptations that were lost during experimental evolution. The direction and magnitude of trait changes can offer useful insight as to whether the microbes have historically been selected to help or harm one another in nature. We apply our method to the complex symbiosis between the social amoeba Dictyostelium discoideum and two intracellular bacterial endosymbionts, Paraburkholderia agricolaris and Paraburkholderia hayleyella. Our results suggest P. hayleyella-but not P. agricolaris-has generally been selected to attenuate its virulence in nature, and that D. discoideum has evolved to antagonistically limit the growth of Paraburkholderia. The approach demonstrated here can be a powerful tool for studying adaptations in microbes, particularly when the specific natural context in which the adaptations evolved is unknown or hard to reproduce.}, }
@article {pmid33584729, year = {2020}, author = {Pimentel, AC and Cesar, CS and Martins, M and Cogni, R}, title = {The Antiviral Effects of the Symbiont Bacteria Wolbachia in Insects.}, journal = {Frontiers in immunology}, volume = {11}, number = {}, pages = {626329}, pmid = {33584729}, issn = {1664-3224}, mesh = {Animals ; *Drosophila/immunology/microbiology/virology ; RNA Virus Infections/*immunology ; RNA Viruses/*immunology ; Symbiosis/*immunology ; Wolbachia/*immunology ; }, abstract = {Wolbachia is a maternally transmitted bacterium that lives inside arthropod cells. Historically, it was viewed primarily as a parasite that manipulates host reproduction, but more recently it was discovered that Wolbachia can also protect Drosophila species against infection by RNA viruses. Combined with Wolbachia's ability to invade insect populations due to reproductive manipulations, this provides a way to modify mosquito populations to prevent them transmitting viruses like dengue. In this review, we discuss the main advances in the field since Wolbachia's antiviral effect was discovered 12 years ago, identifying current research gaps and potential future developments. We discuss that the antiviral effect works against a broad range of RNA viruses and depends on the Wolbachia lineage. We describe what is known about the mechanisms behind viral protection, and that recent studies suggest two possible mechanisms: activation of host immunity or competition with virus for cellular resources. We also discuss how association with Wolbachia may influence the evolution of virus defense on the insect host genome. Finally, we investigate whether the antiviral effect occurs in wild insect populations and its ecological relevance as a major antiviral component in insects.}, }
@article {pmid33580178, year = {2021}, author = {Kapantaidaki, DE and Antonatos, S and Evangelou, V and Papachristos, DP and Milonas, P}, title = {Genetic and endosymbiotic diversity of Greek populations of Philaenus spumarius, Philaenus signatus and Neophilaenus campestris, vectors of Xylella fastidiosa.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {3752}, pmid = {33580178}, issn = {2045-2322}, mesh = {Animals ; Genetic Variation/genetics ; Greece ; Hemiptera/*genetics/*microbiology ; Insect Vectors/genetics/microbiology ; Olea/microbiology ; Phylogeny ; Plant Diseases/microbiology ; Symbiosis/genetics ; Xylella/*genetics/metabolism/pathogenicity ; }, abstract = {The plant-pathogenic bacterium Xylella fastidiosa which causes significant diseases to various plant species worldwide, is exclusively transmitted by xylem sap-feeding insects. Given the fact that X. fastidiosa poses a serious potential threat for olive cultivation in Greece, the main aim of this study was to investigate the genetic variation of Greek populations of three spittlebug species (Philaenus spumarius, P. signatus and Neophilaenus campestris), by examining the molecular markers Cytochrome Oxidase I, cytochrome b and Internal Transcribed Spacer. Moreover, the infection status of the secondary endosymbionts Wolbachia, Arsenophonus, Hamiltonella, Cardinium and Rickettsia, among these populations, was determined. According to the results, the ITS2 region was the less polymorphic, while the analyzed fragments of COI and cytb genes, displayed high genetic diversity. The phylogenetic analysis placed the Greek populations of P. spumarius into the previously obtained Southwest clade in Europe. The analysis of the bacterial diversity revealed a diverse infection status. Rickettsia was the most predominant endosymbiont while Cardinium was totally absent from all examined populations. Philaenus spumarius harbored Rickettsia, Arsenophonus, Hamiltonella and Wolbachia, N. campestris carried Rickettsia, Hamiltonella and Wolbachia while P. signatus was infected only by Rickettsia. The results of this study will provide an important knowledge resource for understanding the population dynamics of vectors of X. fastidiosa with a view to formulate effective management strategies towards the bacterium.}, }
@article {pmid33567508, year = {2021}, author = {Mannella, CA}, title = {VDAC-A Primal Perspective.}, journal = {International journal of molecular sciences}, volume = {22}, number = {4}, pages = {}, pmid = {33567508}, issn = {1422-0067}, support = {U01 HL116321/HL/NHLBI NIH HHS/United States ; U01HLI16321/HL/NHLBI NIH HHS/United States ; P41RR01219/RR/NCRR NIH HHS/United States ; P41 RR001219/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Humans ; *Ion Channel Gating ; Lipid Bilayers/*metabolism ; *Membrane Potentials ; Mitochondria/*physiology ; Voltage-Dependent Anion Channels/*metabolism ; }, abstract = {The evolution of the eukaryotic cell from the primal endosymbiotic event involved a complex series of adaptations driven primarily by energy optimization. Transfer of genes from endosymbiont to host and concomitant expansion (by infolding) of the endosymbiont's chemiosmotic membrane greatly increased output of adenosine triphosphate (ATP) and placed selective pressure on the membrane at the host-endosymbiont interface to sustain the energy advantage. It is hypothesized that critical functions at this interface (metabolite exchange, polypeptide import, barrier integrity to proteins and DNA) were managed by a precursor β-barrel protein ("pβB") from which the voltage-dependent anion-selective channel (VDAC) descended. VDAC's role as hub for disparate and increasingly complex processes suggests an adaptability that likely springs from a feature inherited from pβB, retained because of important advantages conferred. It is proposed that this property is the remarkable structural flexibility evidenced in VDAC's gating mechanism, a possible origin of which is discussed.}, }
@article {pmid33563832, year = {2021}, author = {Lindsey, ARI and Bhattacharya, T and Hardy, RW and Newton, ILG}, title = {Wolbachia and Virus Alter the Host Transcriptome at the Interface of Nucleotide Metabolism Pathways.}, journal = {mBio}, volume = {12}, number = {1}, pages = {}, pmid = {33563832}, issn = {2150-7511}, support = {P40 OD018537/OD/NIH HHS/United States ; R01 AI144430/AI/NIAID NIH HHS/United States ; R21 AI121849/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Drosophila melanogaster/*genetics/microbiology/virology ; Female ; Gene Expression Profiling ; Host-Pathogen Interactions/genetics ; Male ; *Metabolic Networks and Pathways ; *Microbial Interactions ; Mosquito Vectors/microbiology/virology ; Nucleotides/genetics/*metabolism ; Symbiosis ; *Transcriptome ; Virus Diseases/virology ; Virus Replication ; Viruses/*pathogenicity ; Wolbachia/*pathogenicity ; }, abstract = {Wolbachia is a maternally transmitted bacterium that manipulates arthropod and nematode biology in myriad ways. The Wolbachia strain colonizing Drosophila melanogaster creates sperm-egg incompatibilities and protects its host against RNA viruses, making it a promising tool for vector control. Despite successful trials using Wolbachia-transfected mosquitoes for dengue control, knowledge of how Wolbachia and viruses jointly affect insect biology remains limited. Using the Drosophila melanogaster model, transcriptomics and gene expression network analyses revealed pathways with altered expression and splicing due to Wolbachia colonization and virus infection. Included are metabolic pathways previously unknown to be important for Wolbachia-host interactions. Additionally, Wolbachia-colonized flies exhibit a dampened transcriptomic response to virus infection, consistent with early blocking of virus replication. Finally, using Drosophila genetics, we show that Wolbachia and expression of nucleotide metabolism genes have interactive effects on virus replication. Understanding the mechanisms of pathogen blocking will contribute to the effective development of Wolbachia-mediated vector control programs.IMPORTANCE Recently developed arbovirus control strategies leverage the symbiotic bacterium Wolbachia, which spreads in insect populations and blocks viruses from replicating. While this strategy has been successful, details of how this "pathogen blocking" works are limited. Here, we use a combination of virus infections, fly genetics, and transcriptomics to show that Wolbachia and virus interact at host nucleotide metabolism pathways.}, }
@article {pmid33563818, year = {2021}, author = {Sicard, M and Namias, A and Perriat-Sanguinet, M and Carron, E and Unal, S and Altinli, M and Landmann, F and Weill, M}, title = {Cytoplasmic Incompatibility Variations in Relation with Wolbachia cid Genes Divergence in Culex pipiens.}, journal = {mBio}, volume = {12}, number = {1}, pages = {}, pmid = {33563818}, issn = {2150-7511}, mesh = {Animals ; Cell Line ; Centromere Protein A/*genetics ; Culex/*microbiology/physiology ; Cytoplasm/*physiology ; Cytosol/*microbiology ; Female ; Genetic Drift ; Heterocyclic Compounds, 2-Ring ; Host Specificity ; Male ; Phenotype ; Phylogeny ; Symbiosis ; Thiourea/analogs &amp; derivatives ; Wolbachia/*genetics ; }, abstract = {In arthropods, Wolbachia endosymbionts induce conditional sterility, called cytoplasmic incompatibility (CI), resulting from embryonic lethality. CI penetrance (i.e., embryonic death rate) varies depending on host species and Wolbachia strains involved. All Culex pipiens mosquitoes are infected by the endosymbiotic alphaproteobacteria Wolbachia wPip. CI in Culex, characterized as a binary "compatible/incompatible" phenomenon, revealed an unparalleled diversity of patterns linked to the amplification-diversification of cidA and cidB genes. Here, we accurately studied CI penetrance variations in the light of cid genes divergence by generating a C. pipiens compatibility matrix between 11 lines hosting different phylogenetic wPip groups and exhibiting distinct cid gene repertoires. We showed, as expected, that crosses involving wPip from the same group were mostly compatible. In contrast, only 22% of the crosses involving different wPip groups were compatible, while 54% were fully incompatible. For the remaining 24% of the crosses, "intermediate" compatibilities were reported, and a cytological observation of the first zygotic division confirmed the occurrence of "canonical" CI phenotypes in a fraction of the eggs. Backcross experiments demonstrated that intermediate compatibilities were not linked to host genetic background but to the Wolbachia strains involved. This previously unstudied intermediate penetrance CI was more severe and frequent in crosses involving wPip-IV strains exhibiting cid variants markedly divergent from other wPip groups. Our data demonstrate that CI is not always a binary compatible/incompatible phenomenon in C. pipiens but that intermediate compatibilities putatively resulting from partial mismatch due to Cid proteins divergence exist in this species complex.IMPORTANCECulex pipiens mosquitoes are infected with wPip. These endosymbionts induce a conditional sterility called CI resulting from embryonic deaths, which constitutes a cornerstone for Wolbachia antivectorial methods. Recent studies revealed that (i) two genes, cidA and cidB, are central in Wolbachia-CI mechanisms, and (ii) compatibility versus incompatibility between mosquito lines depends on the wPip phylogenetic groups at play. Here, we studied CI variations in relation to wPip groups and cid genes divergence. We showed, as expected, that the crosses involving wPip from the same group were compatible. In contrast, 78% of the crosses involving different wPip groups were partially or fully incompatible. In such crosses, we reported defects during the first zygotic division, a hallmark of CI. We showed that CI was more severe and frequent in crosses involving wPip-IV strains exhibiting cid variants, which markedly diverge from those of other wPip groups.}, }
@article {pmid33561560, year = {2021}, author = {Puthiyaveetil, S and McKenzie, SD and Kayanja, GE and Ibrahim, IM}, title = {Transcription initiation as a control point in plastid gene expression.}, journal = {Biochimica et biophysica acta. Gene regulatory mechanisms}, volume = {1864}, number = {3}, pages = {194689}, doi = {10.1016/j.bbagrm.2021.194689}, pmid = {33561560}, issn = {1876-4320}, mesh = {DNA-Directed RNA Polymerases/genetics/metabolism ; Gene Expression Regulation, Plant/*physiology ; Plant Proteins/genetics/metabolism ; Plastids/genetics/*metabolism ; Transcription Initiation, Genetic/*physiology ; }, abstract = {The extensive processing and protein-assisted stabilization of transcripts have been taken as evidence for a viewpoint that the control of gene expression had shifted entirely in evolution from transcriptional in the bacterial endosymbiont to posttranscriptional in the plastid. This suggestion is however at odds with many observations on plastid gene transcription. Chloroplasts of flowering plants and mosses contain two or more RNA polymerases with distinct promoter preference and division of labor for the coordinated synthesis of plastid RNAs. Plant and algal plastids further possess multiple nonredundant sigma factors that function as transcription initiation factors. The controlled accumulation of plastid sigma factors and modification of their activity by sigma-binding proteins and phosphorylation constitute additional transcriptional regulatory strategies. Plant and algal plastids also contain dedicated one- or two-component transcriptional regulators. Transcription initiation thus continues to form a critical control point at which varied developmental and environmental signals intersect with plastid gene expression.}, }
@article {pmid33561222, year = {2021}, author = {Davey, JW and Catta-Preta, CMC and James, S and Forrester, S and Motta, MCM and Ashton, PD and Mottram, JC}, title = {Chromosomal assembly of the nuclear genome of the endosymbiont-bearing trypanosomatid Angomonas deanei.}, journal = {G3 (Bethesda, Md.)}, volume = {11}, number = {1}, pages = {}, pmid = {33561222}, issn = {2160-1836}, support = {/WT_/Wellcome Trust/United Kingdom ; 200807/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Bacteria/genetics ; Chromosomes ; Genome ; *Symbiosis ; *Trypanosomatina/genetics ; }, abstract = {Angomonas deanei is an endosymbiont-bearing trypanosomatid with several highly fragmented genome assemblies and unknown chromosome number. We present an assembly of the A. deanei nuclear genome based on Oxford Nanopore sequence that resolves into 29 complete or close-to-complete chromosomes. The assembly has several previously unknown special features; it has a supernumerary chromosome, a chromosome with a 340-kb inversion, and there is a translocation between two chromosomes. We also present an updated annotation of the chromosomal genome with 10,365 protein-coding genes, 59 transfer RNAs, 26 ribosomal RNAs, and 62 noncoding RNAs.}, }
@article {pmid33559322, year = {2021}, author = {Almeida, C}, title = {A potential third-order role of the host endoplasmic reticulum as a contact site in interkingdom microbial endosymbiosis and viral infection.}, journal = {Environmental microbiology reports}, volume = {13}, number = {3}, pages = {255-271}, doi = {10.1111/1758-2229.12938}, pmid = {33559322}, issn = {1758-2229}, mesh = {Bacteria/genetics ; Biological Evolution ; Endoplasmic Reticulum/metabolism/microbiology ; Humans ; *Symbiosis ; *Virus Diseases/metabolism ; }, abstract = {The normal functioning of eukaryotic cells depends on the compartmentalization of metabolic processes within specific organelles. Interactions among organelles, such as those between the endoplasmic reticulum (ER) - considered the largest single structure in eukaryotic cells - and other organelles at membrane contact sites (MCSs) have also been suggested to trigger synergisms, including intracellular immune responses against pathogens. In addition to the ER-endogenous functions and ER-organelle MCSs, we present the perspective of a third-order role of the ER as a host contact site for endosymbiotic microbial non-pathogens and pathogens, from endosymbiont bacteria to parasitic protists and viruses. Although understudied, ER-endosymbiont interactions have been observed in a range of eukaryotic hosts, including protists, plants, algae, and metazoans. Host ER interactions with endosymbionts could be an ER function built from ancient, conserved mechanisms selected for communicating with mutualistic endosymbionts in specific life cycle stages, and they may be exploited by pathogens and parasites. The host ER-'guest' interactome and traits in endosymbiotic biology are briefly discussed. The acknowledgment and understanding of these possible mechanisms might reveal novel evolutionary perspectives, uncover the causes of unexplained cellular disorders and suggest new pharmacological targets.}, }
@article {pmid33558689, year = {2021}, author = {Maire, J and Girvan, SK and Barkla, SE and Perez-Gonzalez, A and Suggett, DJ and Blackall, LL and van Oppen, MJH}, title = {Intracellular bacteria are common and taxonomically diverse in cultured and in hospite algal endosymbionts of coral reefs.}, journal = {The ISME journal}, volume = {15}, number = {7}, pages = {2028-2042}, pmid = {33558689}, issn = {1751-7370}, mesh = {Animals ; *Anthozoa/genetics ; Bacteria/genetics ; Coral Reefs ; *Dinoflagellida/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Corals house a variety of microorganisms which they depend on for their survival, including endosymbiotic dinoflagellates (Symbiodiniaceae) and bacteria. While cnidarian-microorganism interactions are widely studied, Symbiodiniaceae-bacteria interactions are only just beginning to receive attention. Here, we describe the localization and composition of the bacterial communities associated with cultures of 11 Symbiodiniaceae strains from nine species and six genera. Three-dimensional confocal laser scanning and electron microscopy revealed bacteria are present inside the Symbiodiniaceae cells as well as closely associated with their external cell surface. Bacterial pure cultures and 16S rRNA gene metabarcoding from Symbiodiniaceae cultures highlighted distinct and highly diverse bacterial communities occur intracellularly, closely associated with the Symbiodiniaceae outer cell surface and loosely associated (i.e., in the surrounding culture media). The intracellular bacteria are highly conserved across Symbiodiniaceae species, suggesting they may be involved in Symbiodiniaceae physiology. Our findings provide unique new insights into the biology of Symbiodiniaceae.}, }
@article {pmid33557932, year = {2021}, author = {Pilgrim, J and Siozios, S and Baylis, M and Venter, G and Garros, C and Hurst, GDD}, title = {Cardinium symbiosis as a potential confounder of mtDNA based phylogeographic inference in Culicoides imicola (Diptera: Ceratopogonidae), a vector of veterinary viruses.}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {100}, pmid = {33557932}, issn = {1756-3305}, support = {BB/M011186/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacterial Infections/*transmission ; Bacteroidetes/genetics ; Ceratopogonidae/*genetics/*microbiology ; DNA, Mitochondrial/chemistry/*genetics ; Gene Flow ; Horses ; Insect Vectors/*microbiology ; Mediterranean Region ; Phylogeny ; Phylogeography ; Sequence Analysis, DNA ; South Africa ; *Symbiosis ; }, abstract = {BACKGROUND: Culicoides imicola (Diptera: Ceratopogonidae) is an important Afrotropical and Palearctic vector of disease, transmitting viruses of animal health and economic significance including African horse sickness and bluetongue viruses. Maternally inherited symbiotic bacteria (endosymbionts) of arthropods can alter the frequency of COI (cytochrome c oxidase subunit I) mitochondrial haplotypes (mitotypes) in a population, masking the true patterns of host movement and gene flow. Thus, this study aimed to assess the mtDNA structure of C. imicola in relation to infection with Candidatus Cardinum hertigii (Bacteroides), a common endosymbiont of Culicoides spp.<br><br>METHODS: Using haplotype network analysis, COI Sanger sequences from Cardinium-infected and -uninfected C. imicola individuals were first compared in a population from South Africa. The network was then extended to include mitotypes from a geographic range where Cardinium infection has previously been investigated.<br><br>RESULTS: The mitotype network of the South African population demonstrated the presence of two broad mitotype groups. All Cardinium-infected specimens fell into one group (Fisher's exact test, P&#x2009;=&#x2009;0.00071) demonstrating a linkage disequilibrium between endosymbiont and mitochondria. Furthermore, by extending this haplotype network to include other C. imicola populations from the Mediterranean basin, we revealed mitotype variation between the Eastern and Western Mediterranean basins (EMB and WMB) mirrored Cardinium-infection heterogeneity.<br><br>CONCLUSIONS: These observations suggest that the linkage disequilibrium of Cardinium and mitochondria reflects endosymbiont gene flow within the Mediterranean basin but may not assist in elucidating host gene flow. Subsequently, we urge caution on the single usage of the COI marker to determine population structure and movement in C. imicola and instead suggest the complementary utilisation of additional molecular markers.}, }
@article {pmid33556614, year = {2021}, author = {Vieri, MK and Hendy, A and Mokili, JL and Colebunders, R}, title = {Nodding syndrome research revisited.}, journal = {International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases}, volume = {104}, number = {}, pages = {739-741}, doi = {10.1016/j.ijid.2021.02.006}, pmid = {33556614}, issn = {1878-3511}, mesh = {Animals ; Biomedical Research/*trends ; Humans ; Nodding Syndrome/*etiology ; Onchocerca volvulus/physiology ; Onchocerciasis/*complications/parasitology ; Prevalence ; }, abstract = {Nodding syndrome is one of several forms of onchocerciasis-associated epilepsy (OAE) seen among children in areas formerly hyperendemic for the transmission of Onchocerca volvulus. These forms of epilepsy are highly prevalent and clustered in certain villages located close to blackfly (Diptera: Simuliidae) breeding sites. OAE presents with a wide spectrum of seizures, including generalized tonic-clonic and head nodding seizures, impaired cognitive function, growth stunting and delayed puberty. In 2014, the present authors published a perspective paper in this journal which hypothesized that nodding syndrome may be caused by either a neurotropic virus transmitted by blackflies or an endosymbiont present within the O. volvulus parasite. Seven years later, this critical review presents progress in nodding syndrome research, and assesses whether it is still plausible that a neurotropic virus or endosymbiont could be the cause.}, }
@article {pmid33548192, year = {2021}, author = {Iha, C and Dougan, KE and Varela, JA and Avila, V and Jackson, CJ and Bogaert, KA and Chen, Y and Judd, LM and Wick, R and Holt, KE and Pasella, MM and Ricci, F and Repetti, SI and Medina, M and Marcelino, VR and Chan, CX and Verbruggen, H}, title = {Genomic adaptations to an endolithic lifestyle in the coral-associated alga Ostreobium.}, journal = {Current biology : CB}, volume = {31}, number = {7}, pages = {1393-1402.e5}, doi = {10.1016/j.cub.2021.01.018}, pmid = {33548192}, issn = {1879-0445}, mesh = {Adaptation, Biological/*genetics ; Animals ; *Anthozoa ; Chlorophyta/*genetics ; *Genomics ; *Symbiosis ; }, abstract = {The green alga Ostreobium is an important coral holobiont member, playing key roles in skeletal decalcification and providing photosynthate to bleached corals that have lost their dinoflagellate endosymbionts. Ostreobium lives in the coral's skeleton, a low-light environment with variable pH and O2 availability. We present the Ostreobium nuclear genome and a metatranscriptomic analysis of healthy and bleached corals to improve our understanding of Ostreobium's adaptations to its extreme environment and its roles as a coral holobiont member. The Ostreobium genome has 10,663 predicted protein-coding genes and shows adaptations for life in low and variable light conditions and other stressors in the endolithic environment. This alga presents a rich repertoire of light-harvesting complex proteins but lacks many genes for photoprotection and photoreceptors. It also has a large arsenal of genes for oxidative stress response. An expansion of extracellular peptidases suggests that Ostreobium may supplement its energy needs by feeding on the organic skeletal matrix, and a diverse set of fermentation pathways allows it to live in the anoxic skeleton at night. Ostreobium depends on other holobiont members for vitamin B12, and our metatranscriptomes identify potential bacterial sources. Metatranscriptomes showed Ostreobium becoming a dominant agent of photosynthesis in bleached corals and provided evidence for variable responses among coral samples and different Ostreobium genotypes. Our work provides a comprehensive understanding of the adaptations of Ostreobium to its extreme environment and an important genomic resource to improve our comprehension of coral holobiont resilience, bleaching, and recovery.}, }
@article {pmid33543432, year = {2021}, author = {Nazipi, S and Vangkilde-Pedersen, SG and Busck, MM and Lund, DK and Marshall, IPG and Bilde, T and Lund, MB and Schramm, A}, title = {An antimicrobial Staphylococcus sciuri with broad temperature and salt spectrum isolated from the surface of the African social spider, Stegodyphus dumicola.}, journal = {Antonie van Leeuwenhoek}, volume = {114}, number = {3}, pages = {325-335}, pmid = {33543432}, issn = {1572-9699}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; *Spiders ; Staphylococcus/genetics ; Temperature ; }, abstract = {Some social arthropods engage in mutualistic symbiosis with antimicrobial compound-producing microorganisms that provide protection against pathogens. Social spiders live in communal nests and contain specific endosymbionts with unknown function. Bacteria are also found on the spiders' surface, including prevalent staphylococci, which may have protective potential. Here we present the genomic and phenotypic characterization of strain i1, isolated from the surface of the social spider Stegodyphus dumicola. Phylogenomic analysis identified i1 as novel strain of Staphylococcus sciuri within subgroup 2 of three newly defined genomic subgroups. Further phenotypic investigations showed that S. sciuri i1 is an extremophile that can grow at a broad range of temperatures (4 °C-45 °C), high salt concentrations (up to 27%), and has antimicrobial activity against closely related species. We identified a lactococcin 972-like bacteriocin gene cluster, likely responsible for the antimicrobial activity, and found it conserved in two of the three subgroups of S. sciuri. These features indicate that S. sciuri i1, though not a specific symbiont, is well-adapted to survive on the surface of social spiders and may gain a competitive advantage by inhibiting closely related species.}, }
@article {pmid33540276, year = {2021}, author = {Al-Hosary, A and Răileanu, C and Tauchmann, O and Fischer, S and Nijhof, AM and Silaghi, C}, title = {Tick species identification and molecular detection of tick-borne pathogens in blood and ticks collected from cattle in Egypt.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {3}, pages = {101676}, doi = {10.1016/j.ttbdis.2021.101676}, pmid = {33540276}, issn = {1877-9603}, mesh = {Animals ; Cattle ; Cattle Diseases/*epidemiology/microbiology/parasitology ; Egypt/epidemiology ; Female ; Ixodidae/classification/growth &amp; development/*microbiology ; Male ; Nymph/classification/growth &amp; development/microbiology ; Tick Infestations/parasitology/veterinary ; Tick-Borne Diseases/epidemiology/microbiology/*veterinary ; }, abstract = {To address the lack of information on ticks infesting cattle in Egypt and the pathogens that they transmit, the current study aimed to (i) provide insight into tick species found on cattle in Egypt, (ii) identify the pathogens in ticks and their cattle hosts and (iii) detect pathogen associations in ticks and cattle. Tick samples and blood from their bovine hosts were collected from three different areas in Egypt (EL-Faiyum Oasis, Assiut Governorate and EL-Kharga Oasis). Tick species were identified by morphology and by sequence analysis of the cytochrome C oxidase subunit 1 (cox1) gene. Tick pools and blood samples from cattle were screened by the Reverse Line Blot hybridization (RLB) assay for the simultaneous detection of tick-borne pathogens, including Babesia, Theileria, Anaplasma, Ehrlichia, and Rickettsia spp., as well as the tick endosymbiont Midichloria mitochondrii. The RLB results were confirmed with specific conventional and semi-nested PCRs followed by sequencing. In total, 570 ticks (males, females and nymphs) were collected from 41 heads of cattle. Altogether 398 ticks belonged to the genus Hyalomma (397 Hyalomma excavatum and one Hyalomma scupense) while 172 ticks were identified as Rhipicephalus annulatus. Pooled H. excavatum ticks tested positive for several protozoa and bacteria with different minimum infection rates (MIRs): Theileria annulata (18.1 %), Babesia occultans (1.8 %), Anaplasma marginale (28.5 %), Anaplasma platys (0.25 %), Midichloria mitochondrii (11.6 %), Ehrlichia chaffeensis-like (1.8 %) and Ehrlichia minasensis (1 %). In R. annulatus, several agents were identified at different MIRs: T. annulata (2.3 %), B. bovis (0.6 %), A. marginale (18.0 %), A. platys (1.2 %), M. mitochondrii (2.9 %), E. minasensis (0.6 %). Pathogens co-detection in tick pools revealed A. marginale and T. annulata in 13.3 % samples followed by the co-detection of A. marginale and M. mitochondrii (8.4 %). In addition, triple co-detection with A. marginale, T. annulata and M. mitochondrii were found in 5.3 % of the tick pools. In cattle, the most common coinfection was with A. marginale and T. annulata (82.9 %) followed by the coinfection between A. marginale, T. annulata and B. bovis (4.9 %), A. marginale and B. bigemina (2.4 %) and finally the coinfection between T. annulata and B. occultans (2.4 %). Anaplasma platys, Babesia occultans, and E. minasensis were detected for the first time in Egypt in both cattle and ticks. These findings should be taken in consideration regarding human and animal wellbeing by the public health and veterinary authorities in Egypt.}, }
@article {pmid33536456, year = {2021}, author = {Tikhonenkov, DV and Gawryluk, RMR and Mylnikov, AP and Keeling, PJ}, title = {First finding of free-living representatives of Prokinetoplastina and their nuclear and mitochondrial genomes.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {2946}, pmid = {33536456}, issn = {2045-2322}, mesh = {Biological Evolution ; Cell Nucleus/*genetics ; *Genome, Mitochondrial ; Kinetoplastida/cytology/*genetics ; Phylogeny ; }, abstract = {Kinetoplastids are heterotrophic flagellated protists, including important parasites of humans and animals (trypanosomatids), and ecologically important free-living bacterial consumers (bodonids). Phylogenies have shown that the earliest-branching kinetoplastids are all parasites or obligate endosymbionts, whose highly-derived state makes reconstructing the ancestral state of the group challenging. We have isolated new strains of unusual free-living flagellates that molecular phylogeny shows to be most closely related to endosymbiotic and parasitic Perkinsela and Ichthyobodo species that, together with unidentified environmental sequences, form the clade at the base of kinetoplastids. These strains are therefore the first described free-living prokinetoplastids, and potentially very informative in understanding the evolution and ancestral states of morphological and molecular characteristics described in other kinetoplastids. Overall, we find that these organisms morphologically and ultrastructurally resemble some free-living bodonids and diplonemids, and possess nuclear genomes with few introns, polycistronic mRNA expression, high coding density, and derived traits shared with other kinetoplastids. Their genetic repertoires are more diverse than the best-studied free-living kinetoplastids, which is likely a reflection of their higher metabolic potential. Mitochondrial RNAs of these new species undergo the most extensive U insertion/deletion editing reported so far, and limited deaminative C-to-U and A-to-I editing, but we find no evidence for mitochondrial trans-splicing.}, }
@article {pmid33531619, year = {2021}, author = {Sandoval-Mojica, AF and Hunter, WB and Aishwarya, V and Bonilla, S and Pelz-Stelinski, KS}, title = {Antibacterial FANA oligonucleotides as a novel approach for managing the Huanglongbing pathosystem.}, journal = {Scientific reports}, volume = {11}, number = {1}, pages = {2760}, pmid = {33531619}, issn = {2045-2322}, mesh = {Animals ; Arabinonucleotides/administration &amp; dosage/genetics ; Cell Line ; Citrus/microbiology ; Drosophila ; Gene Expression Regulation, Bacterial/*drug effects ; Gene Silencing ; Hemiptera/drug effects/*microbiology ; Insect Vectors/drug effects/microbiology ; Oligonucleotides, Antisense/*administration &amp; dosage/genetics ; Plant Diseases/microbiology/*prevention &amp; control ; Rhizobiaceae/*drug effects/genetics/pathogenicity ; Symbiosis/drug effects/genetics ; }, abstract = {Candidatus Liberibacter asiaticus (CLas), a bacterium transmitted by the Asian citrus psyllid, Diaphorina citri, is the causal agent of citrus greening disease, or Huanglongbng (HLB). Currently, vector population suppression with insecticides and tree removal are the most effective strategies for managing the HLB pathosystem. In this study, we assessed the bactericidal capabilities of 2'-deoxy-2'-fluoro-D-arabinonucleic acid antisense oligonucleotides (FANA ASO) both in vitro and in vivo by (1) confirming their capacity to penetrate insect cells, (2) silencing bacterial essential genes, and (3) quantifying reductions in bacterial titer and D. citri transmission. We confirmed that FANA ASO are able to penetrate insect cells without the use of a delivery agent. Expression of an essential gene in the D. citri endosymbiont, Wolbachia (wDi), significantly decreased by 30% following incubation with a wDi-specific FANA ASO. Viability of isolated wDi cells also decreased in response to the FANA ASO treatment. Delivery of a CLas-specific FANA ASO to infected adult D. citri in feeding assays resulted in significant silencing of a CLas essential gene. CLas relative density and transmission were significantly lower among D. citri fed FANA ASO in diet compared to untreated insects. Root infusions of a CLas-specific FANA ASO into infected Citrus trees significantly reduced CLas titer during a 30-day trial. Our results suggest that FANA ASO targeting insect-transmitted plant bacteria or insect endosymbionts may be useful tool for integrated management of agricultural pathogens.}, }
@article {pmid33531407, year = {2021}, author = {Myers, KN and Conn, D and Brown, AMV}, title = {Essential Amino Acid Enrichment and Positive Selection Highlight Endosymbiont's Role in a Global Virus-Vectoring Pest.}, journal = {mSystems}, volume = {6}, number = {1}, pages = {}, pmid = {33531407}, issn = {2379-5077}, abstract = {Host-associated microbes display remarkable convergence in genome repertoire resulting from selection to supplement missing host functions. Nutritional supplementation has been proposed in the verrucomicrobial endosymbiont Xiphinematobacter sp., which lives within a globally widespread group of plant-parasitic nematodes that vector damaging nepoviruses to plants. Only one genome sequence has been published from this symbiont, leaving unanswered questions about its diversity, host range, role, and selective pressures within its hosts. Because its hosts are exceptionally resistant to culturing, this symbiont is best studied through advanced genomic approaches. To analyze the role of Xiphinematobacter sp. in its host, sequencing was performed on nematode communities, and then genomes were extracted for comparative genomics, gene ontology enrichment tests, polymorphism analysis, de Bruijn-based genome-wide association studies, and tests of pathway- and site-specific selection on genes predicted play a role in the symbiosis. Results showed a closely clustered set of Xiphinematobacter isolates with reduced genomes of ∼917 kbp, for which a new species was proposed. Symbionts shared only 2.3% of genes with outgroup Verrucomicrobia, but comparative analyses showed high conservation of all 10 essential amino acid (EAA) biosynthesis pathways plus several vitamin pathways. These findings were supported by gene ontology enrichment tests and high polymorphisms in these pathways compared with background. Genome-wide association analysis confirmed high between-species fixation of alleles with significant functional enrichment for EAA and thiamine synthesis. Strong positive selection was detected on sites within these pathways, despite several being under increased purifying selection. Together, these results suggest that supplementation of EAAs missing in the host diet may drive this widespread symbiosis.IMPORTANCE Xiphinematobacter spp. are distinctly evolved intracellular symbionts in the phylum Verrucomicrobia, which includes the important human gut-associated microbe Akkermansia muciniphila and many highly abundant free-living soil microbes. Like Akkermansia sp., Xiphinematobacter sp. is obligately associated with the gut of its hosts, which in this case consists of a group of plant-parasitic nematodes that are among the top 10 most destructive species to global agriculture, by vectoring plant viruses. This study examined the hypothesis that the key to this symbiont's stable evolutionary association with its host is through provisioning nutrients that its host cannot make that may be lacking in the nematode's plant phloem diet, such as essential amino acids and several vitamins. The significance of our research is in demonstrating, using population genomics, the signatures of selective pressure on these hypothesized roles to ultimately learn how this independently evolved symbiont functionally mirrors symbionts of phloem-feeding insects.}, }
@article {pmid33519791, year = {2020}, author = {Kaech, H and Vorburger, C}, title = {Horizontal Transmission of the Heritable Protective Endosymbiont Hamiltonella defensa Depends on Titre and Haplotype.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {628755}, pmid = {33519791}, issn = {1664-302X}, abstract = {Secondary endosymbionts of aphids have an important ecological and evolutionary impact on their host, as they provide resistance to natural enemies but also reduce the host's lifespan and reproduction. While secondary symbionts of aphids are faithfully transmitted from mother to offspring, they also have some capacity to be transmitted horizontally between aphids. Here we explore whether 11 isolates from 3 haplotypes of the secondary endosymbiont Hamiltonella defensa differ in their capacity for horizontal transmission. These isolates vary in the protection they provide against parasitoid wasps as well as the costs they inflict on their host, Aphis fabae. We simulated natural horizontal transmission through parasitoid wasps by stabbing aphids with a thin needle and assessed horizontal transmission success of the isolates from one shared donor clone into three different recipient clones. Specifically, we asked whether potentially costly isolates reaching high cell densities in aphid hosts are more readily transmitted through this route. This hypothesis was only partially supported. While transmissibility increased with titre for isolates from two haplotypes, isolates of the H. defensa haplotype 1 were transmitted with greater frequency than isolates of other haplotypes with comparable titres. Thus, it is not sufficient to be merely frequent-endosymbionts might have to evolve specific adaptations to transmit effectively between hosts.}, }
@article {pmid33514519, year = {2021}, author = {Kueneman, JG and Esser, HJ and Weiss, SJ and Jansen, PA and Foley, JE}, title = {Tick Microbiomes in Neotropical Forest Fragments Are Best Explained by Tick-Associated and Environmental Factors Rather than Host Blood Source.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {7}, pages = {}, pmid = {33514519}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Forests ; Larva/growth &amp; development/microbiology ; Mammals/parasitology ; *Microbiota ; Nymph/growth &amp; development/microbiology ; Panama ; Ticks/growth &amp; development/*microbiology ; }, abstract = {The composition of tick microbiomes varies both within and among tick species. Whether this variation is intrinsic (related to tick characteristics) or extrinsic (related to vertebrate host and habitat) is poorly understood but important, as microbiota can influence the reproductive success and vector competence of ticks. We aimed to uncover what intrinsic and extrinsic factors best explain the microbial composition and taxon richness of 11 species of neotropical ticks collected from eight species of small mammals in 18 forest fragments across central Panama. Microbial richness varied among tick species, life stages, and collection sites but was not related to host blood source. Microbiome composition was best explained by tick life stage, with bacterial assemblages of larvae being a subset of those of nymphs. Collection site explained most of the bacterial taxa with differential abundance across intrinsic and extrinsic factors. Francisella and Rickettsia were highly prevalent, but their proportional abundance differed greatly among tick species, and we found both positive and negative cooccurrence between members of these two genera. Other tick endosymbionts (e.g., Coxiella and Rickettsiella) were associated with specific tick species. In addition, we detected Anaplasma and Bartonella in several tick species. Our results indicate that the microbial composition and richness of neotropical ticks are principally related to intrinsic factors (tick species and life stage) and collection site. Taken together, our analysis informs how tick microbiomes are structured and can help anchor our understanding of tick microbiomes from tropical environments more broadly.IMPORTANCE Blood-feeding arthropod microbiomes often play important roles in disease transmission, yet the factors that structure tick microbial communities in the Neotropics are unknown. Utilizing ticks collected from live animals in neotropical forest fragments, this study teases apart the contributions of intrinsic and extrinsic tick-associated factors on tick microbial composition as well as which specific microbes contribute to differences across tick species, tick life stages, the mammals they fed on, and the locations from where they were sampled. Furthermore, this study provides revelations of how notable tick-associated bacterial genera are interacting with other tick-associated microbes as well as the forest animals they encounter.}, }
@article {pmid33514310, year = {2021}, author = {Shi, XB and Yan, S and Zhang, C and Zheng, LM and Zhang, ZH and Sun, SE and Gao, Y and Tan, XQ and Zhang, DY and Zhou, XG}, title = {Aphid endosymbiont facilitates virus transmission by modulating the volatile profile of host plants.}, journal = {BMC plant biology}, volume = {21}, number = {1}, pages = {67}, pmid = {33514310}, issn = {1471-2229}, mesh = {Animals ; Aphids/drug effects/microbiology/physiology/*virology ; Buchnera/*physiology ; Capsicum/microbiology/parasitology/*virology ; Cucumovirus/*physiology ; Feeding Behavior ; Host-Parasite Interactions ; Insect Vectors/physiology ; Plant Diseases/microbiology/parasitology/*virology ; Rifampin/pharmacology ; *Symbiosis ; Volatile Organic Compounds/metabolism ; }, abstract = {BACKGROUND: Most plant viruses rely on vectors for their transmission and spread. One of the outstanding biological questions concerning the vector-pathogen-symbiont multi-trophic interactions is the potential involvement of vector symbionts in the virus transmission process. Here, we used a multi-factorial system containing a non-persistent plant virus, cucumber mosaic virus (CMV), its primary vector, green peach aphid, Myzus persicae, and the obligate endosymbiont, Buchnera aphidicola to explore this uncharted territory.<br><br>RESULTS: Based on our preliminary research, we hypothesized that aphid endosymbiont B. aphidicola can facilitate CMV transmission by modulating plant volatile profiles. Gene expression analyses demonstrated that CMV infection reduced B. aphidicola abundance in M. persicae, in which lower abundance of B. aphidicola was associated with a preference shift in aphids from infected to healthy plants. Volatile profile analyses confirmed that feeding by aphids with lower B. aphidicola titers reduced the production of attractants, while increased the emission of deterrents. As a result, M. persicae changed their feeding preference from infected to healthy plants.<br><br>CONCLUSIONS: We conclude that CMV infection reduces the B. aphidicola abundance in M. persicae. When viruliferous aphids feed on host plants, dynamic changes in obligate symbionts lead to a shift in plant volatiles from attraction to avoidance, thereby switching insect vector's feeding preference from infected to healthy plants.}, }
@article {pmid33503057, year = {2021}, author = {de Kluijver, A and Nierop, KGJ and Morganti, TM and Bart, MC and Slaby, BM and Hanz, U and de Goeij, JM and Mienis, F and Middelburg, JJ}, title = {Bacterial precursors and unsaturated long-chain fatty acids are biomarkers of North-Atlantic deep-sea demosponges.}, journal = {PloS one}, volume = {16}, number = {1}, pages = {e0241095}, pmid = {33503057}, issn = {1932-6203}, support = {294757/ERC_/European Research Council/International ; }, mesh = {Animals ; *Aquatic Organisms/classification/metabolism/microbiology ; Fatty Acids, Unsaturated/*metabolism ; Geodia/*metabolism ; Porifera/*microbiology ; }, abstract = {Sponges produce distinct fatty acids (FAs) that (potentially) can be used as chemotaxonomic and ecological biomarkers to study endosymbiont-host interactions and the functional ecology of sponges. Here, we present FA profiles of five common habitat-building deep-sea sponges (class Demospongiae, order Tetractinellida), which are classified as high microbial abundance (HMA) species. Geodia hentscheli, G. parva, G. atlantica, G. barretti, and Stelletta rhaphidiophora were collected from boreal and Arctic sponge grounds in the North-Atlantic Ocean. Bacterial FAs dominated in all five species and particularly isomeric mixtures of mid-chain branched FAs (MBFAs, 8- and 9-Me-C16:0 and 10- and 11-Me-C18:0) were found in high abundance (together ≥ 20% of total FAs) aside more common bacterial markers. In addition, the sponges produced long-chain linear, mid- and a(i)-branched unsaturated FAs (LCFAs) with a chain length of 24‒28 C atoms and had predominantly the typical Δ5,9 unsaturation, although the Δ9,19 and (yet undescribed) Δ11,21 unsaturations were also identified. G. parva and S. rhaphidiophora each produced distinct LCFAs, while G. atlantica, G. barretti, and G. hentscheli produced similar LCFAs, but in different ratios. The different bacterial precursors varied in carbon isotopic composition (δ13C), with MBFAs being more enriched compared to other bacterial (linear and a(i)-branched) FAs. We propose biosynthetic pathways for different LCFAs from their bacterial precursors, that are consistent with small isotopic differences found in LCFAs. Indeed, FA profiles of deep-sea sponges can serve as chemotaxonomic markers and support the concept that sponges acquire building blocks from their endosymbiotic bacteria.}, }
@article {pmid33499057, year = {2021}, author = {Dittmer, J and Lusseau, T and Foissac, X and Faoro, F}, title = {Skipping the Insect Vector: Plant Stolon Transmission of the Phytopathogen 'Ca. Phlomobacter fragariae' from the Arsenophonus Clade of Insect Endosymbionts.}, journal = {Insects}, volume = {12}, number = {2}, pages = {}, pmid = {33499057}, issn = {2075-4450}, abstract = {The genus Arsenophonus represents one of the most widespread clades of insect endosymbionts, including reproductive manipulators and bacteriocyte-associated primary endosymbionts. Two strains belonging to the Arsenophonus clade have been identified as insect-vectored plant pathogens of strawberry and sugar beet. The bacteria accumulate in the phloem of infected plants, ultimately causing leaf yellows and necrosis. These symbionts therefore represent excellent model systems to investigate the evolutionary transition from a purely insect-associated endosymbiont towards an insect-vectored phytopathogen. Using quantitative PCR and transmission electron microscopy, we demonstrate that 'Candidatus Phlomobacter fragariae', bacterial symbiont of the planthopper Cixius wagneri and the causative agent of Strawberry Marginal Chlorosis disease, can be transmitted from an infected strawberry plant to multiple daughter plants through stolons. Stolons are horizontally growing stems enabling the nutrient provisioning of daughter plants during their early growth phase. Our results show that Phlomobacter was abundant in the phloem sieve elements of stolons and was efficiently transmitted to daughter plants, which rapidly developed disease symptoms. From an evolutionary perspective, Phlomobacter is, therefore, not only able to survive within the plant after transmission by the insect vector, but can even be transmitted to new plant generations, independently from its ancestral insect host.}, }
@article {pmid33492720, year = {2021}, author = {Gao, X and Niu, R and Zhu, X and Wang, L and Ji, J and Niu, L and Wu, C and Zhang, S and Luo, J and Cui, J}, title = {Characterization and comparison of the bacterial microbiota of Lysiphlebia japonica parasitioid wasps and their aphid host Aphis gosypii.}, journal = {Pest management science}, volume = {77}, number = {6}, pages = {2710-2718}, doi = {10.1002/ps.6299}, pmid = {33492720}, issn = {1526-4998}, mesh = {Animals ; *Aphids ; Bacteria/genetics ; *Buchnera ; *Microbiota ; Symbiosis ; *Wasps ; }, abstract = {BACKGROUND: Endosymbiotic bacteria have been reported to mediate interactions between parasitoids and their insect hosts. How parasitic wasps influence changes in host microbial communities and the relationship between them are of great importance to the study of host-parasitoid co-evolutionary and ecological interactions. However, these interactions remain largely unreported for interactions between Aphis gossypii and Lysiphlebia japonica.<br><br>RESULTS: In this study, we characterize the bacterial microbiota of L. japonica wasps at different developmental stages and monitor changes over time in the bacterial microbiota of their parasitized and nonparasitized aphid hosts, using metagenomic analysis of 16S rDNA sequencing data. Proteobacteria, Firmicutes, and Actinobacteria were the three most abundant bacterial phyla identified in L. japonica. We found that parasitism was associated with an increased abundance of Buchnera nutritional endosymbionts, but decreased abundance of Acinetobacter, Arsenophonus, Candidatus_Hamiltonella, and Pseudomonas facultative symbionts in aphid hosts. Functional analysis of enriched pathways of parasitized aphids showed significant differences in the 'transport and metabolism of carbohydrates' and 'amino acid, lipid, and coenzyme biosynthesis' pathways. Notably, the composition of symbiotic bacteria in wasp larvae was highly similar to that of their aphid hosts, especially the high abundance of Buchnera.<br><br>CONCLUSION: The results provide a conceptual framework for L. japonica interactions with A. gossypii in which the exchange of symbiotic microbes provides a means by which microbiota can potentially serve as evolutionary drivers of complex, multilevel interactions underlying the ecology and co-evolution of these hosts and parasites. &#xa9; 2021 Society of Chemical Industry.}, }
@article {pmid33492605, year = {2021}, author = {Chisu, V and Mura, L and Foxi, C and Masala, G}, title = {Coxiellaceae in Ticks from Human, Domestic and Wild Hosts from Sardinia, Italy: High Diversity of Coxiella-like Endosymbionts.}, journal = {Acta parasitologica}, volume = {66}, number = {2}, pages = {654-663}, pmid = {33492605}, issn = {1896-1851}, mesh = {Animals ; Coxiella/genetics ; *Coxiellaceae ; Humans ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Ticks ; }, abstract = {PURPOSE: Coxiella burnetii is known for its potential as veterinary and human bacterial pathogen. The bacteria have been described in ticks, but their role in transmission of Q fever in humans is considered low. Coxiella endosymbionts closely related to C. burnetii have been also isolated from an extensive range of tick species and evidence is growing that these endosymbionts could be linked to human bacteremia. The aim of this study was to get new information on the presence of Coxiella species in ticks infesting wild and domestic hosts in Sardinia, Italy.<br><br>METHODS: Here, 138 ticks collected from the study area were analyzed for the presence of C. burnetii and Coxiella-like bacteria by polymerase chain reaction (PCR), sequencing and philogenetic analyses using a set of primers targeting the 16S rRNA gene.<br><br>RESULTS: DNA of Coxiella species was detected in 69% of the total ticks examined. Based on phylogenetic analysis, the 16S rRNA Coxiella genotypes identified in this study grouped in strongly supported monophyletic clades with identified reference sequences of CLEs detected from Rhipicephalus, Dermacentor, Haemaphysalis and Ornithodoros species and with Coxiella burnetii strains isolated worldwide.<br><br>CONCLUSION: This study reports the molecular detection of a high diversity of Coxiella-like bacteria in Sardinian ticks and confirms also the presence of C. burnetii in tick species previously identified in the island. The role that Coxiella-like endosymbionts play in Sardinian ticks and in their vertebrate hosts needs to be explored further.}, }
@article {pmid33489283, year = {2020}, author = {Seas, C and Chaverri, P}, title = {Response of psychrophilic plant endosymbionts to experimental temperature increase.}, journal = {Royal Society open science}, volume = {7}, number = {12}, pages = {201405}, pmid = {33489283}, issn = {2054-5703}, abstract = {Countless uncertainties remain regarding the effects of global warming on biodiversity, including the ability of organisms to adapt and how that will affect obligate symbiotic relationships. The present study aimed to determine the consequences of temperature increase in the adaptation of plant endosymbionts (endophytes) that grow better at low temperatures (psychrophilic). We isolated fungal endophytes from a high-elevation (paramo) endemic plant, Chusquea subtessellata. Initial growth curves were constructed at different temperatures (4-25°C). Next, experiments were carried out in which only the psychrophilic isolates were subjected to repeated increments in temperature. After the experiments, the final growth curves showed significantly slower growth than the initial curves, and some isolates even ceased to grow. While most studies suggest that the distribution of microorganisms will expand as temperatures increase because most of these organisms grow better at 25°C, the results from our experiments demonstrate that psychrophilic fungi were negatively affected by temperature increases. These outcomes raise questions concerning the potential adaptation of beneficial endosymbiotic fungi in the already threatened high-elevation ecosystems. Assessing the consequences of global warming at all trophic levels is urgent because many species on Earth depend on their microbial symbionts for survival.}, }
@article {pmid33488562, year = {2020}, author = {Wang, B and Artsimovitch, I}, title = {NusG, an Ancient Yet Rapidly Evolving Transcription Factor.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {619618}, pmid = {33488562}, issn = {1664-302X}, abstract = {Timely and accurate RNA synthesis depends on accessory proteins that instruct RNA polymerase (RNAP) where and when to start and stop transcription. Among thousands of transcription factors, NusG/Spt5 stand out as the only universally conserved family of regulators. These proteins interact with RNAP to promote uninterrupted RNA synthesis and with diverse cellular partners to couple transcription to RNA processing, modification or translation, or to trigger premature termination of aberrant transcription. NusG homologs are present in all cells that utilize bacterial-type RNAP, from endosymbionts to plants, underscoring their ancient and essential function. Yet, in stark contrast to other core RNAP components, NusG family is actively evolving: horizontal gene transfer and sub-functionalization drive emergence of NusG paralogs, such as bacterial LoaP, RfaH, and UpxY. These specialized regulators activate a few (or just one) operons required for expression of antibiotics, capsules, secretion systems, toxins, and other niche-specific macromolecules. Despite their common origin and binding site on the RNAP, NusG homologs differ in their target selection, interacting partners and effects on RNA synthesis. Even among housekeeping NusGs from diverse bacteria, some factors promote pause-free transcription while others slow the RNAP down. Here, we discuss structure, function, and evolution of NusG proteins, focusing on unique mechanisms that determine their effects on gene expression and enable bacterial adaptation to diverse ecological niches.}, }
@article {pmid33488560, year = {2020}, author = {Henriquez, FL and Mooney, R and Bandel, T and Giammarini, E and Zeroual, M and Fiori, PL and Margarita, V and Rappelli, P and Dessì, D}, title = {Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {616213}, pmid = {33488560}, issn = {1664-302X}, abstract = {Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.}, }
@article {pmid33486127, year = {2021}, author = {Lozano-Sardaneta, YN and Valderrama, A and Sánchez-Montes, S and Grostieta, E and Colunga-Salas, P and Sánchez-Cordero, V and Becker, I}, title = {Rickettsial agents detected in the genus Psathyromyia (Diptera:Phlebotominae) from a Biosphere Reserve of Veracruz, Mexico.}, journal = {Parasitology international}, volume = {82}, number = {}, pages = {102286}, doi = {10.1016/j.parint.2021.102286}, pmid = {33486127}, issn = {1873-0329}, mesh = {Animals ; Female ; Mexico ; Psychodidae/*microbiology ; Rickettsia/*isolation &amp; purification ; Wolbachia/*isolation &amp; purification ; }, abstract = {Phlebotomine sand flies are considered the main vectors of Leishmania, the causal agents of leishmaniasis, which is a serious emerging public health problem worldwide. The use of biological control alternatives, like endosymbiotic bacteria (Wolbachia and Rickettsia), have been proposed to decrease sand fly populations and reduce Leishmania transmissions, yet only few records on the detection of Wolbachia or Rickettsia in sand flies are available worldwide. The aim of this study was to perform the molecular detection of Rickettsial agents associated with sand flies from the last patch of a rainforest in south-eastern Mexico, where a high prevalence of Leishmania infantum has been reported. Sampling effort of sand flies covered 300 trap-nights between 2011 and 2013, and a total of 925 specimens from twelve species were morphologically identified. Using PCR techniques, we identified a new lineage of the endosymbionts Rickettsia in Psathyromyia aclydifera (prevalence of 19.54%), and Wolbachia in Psathyromyia shannoni and Lutzomyia sp. (prevalence of 25%). The detected Wolbachia lineage was similar to the wWhi strain found in Pa. shannoni from Colombia and Nyssomyia whitmani from Brazil; whereas the identified Rickettsia represents a new lineage worldwide. This is the first record of Rickettsial agents associated to sand flies from this region, yet it remains for analysed if these bacteria possibly play a role as vector control agents, capable of reducing the sand fly populations in Mexico.}, }
@article {pmid33484388, year = {2021}, author = {Yang, K and Chen, H and Bing, XL and Xia, X and Zhu, YX and Hong, XY}, title = {Wolbachia and Spiroplasma could influence bacterial communities of the spider mite Tetranychus truncatus.}, journal = {Experimental &amp; applied acarology}, volume = {83}, number = {2}, pages = {197-210}, pmid = {33484388}, issn = {1572-9702}, mesh = {Animals ; Bacteria/genetics ; RNA, Ribosomal, 16S/genetics ; *Spiroplasma/genetics ; Symbiosis ; *Tetranychidae/genetics ; *Wolbachia/genetics ; }, abstract = {The structures of arthropod bacterial communities are complex. These microbiotas usually provide many beneficial services to their hosts, whereas occasionally they may be parasitical. To date, little is known about the bacterial communities of Tetranychus truncatus and the factors contributing to the structure of its bacterial communities are unexplored yet. Here, we used four symbiont-infected T. truncatus strains-including one Wolbachia and Spiroplasma co-infected strain, two symbiont singly-infected strains and one symbiont uninfected strain-to investigate the influence of endosymbionts on the structure of the host mites' microbiota. Based on 16S rRNA genes sequencing analysis, we found Wolbachia and Spiroplasma were the two most abundant bacteria in T. truncatus and the presence of both symbionts could not change the diversity of bacterial communities (based on alpha-diversity indexes such as ACE, Chao1, Shannon and Simpson diversity index). Symbiont infection did alter the abundance of many other bacterial genera, such as Megamonas and Bacteroides. The structures of bacterial communities differed significantly among symbiont-infected strains. These results suggested a prominent effect of Wolbachia and Spiroplasma on bacterial communities of the host T. truncatus. These findings advance our understanding of T. truncatus microbiota and will be helpful for further study on bacterial communities of spider mites.}, }
@article {pmid33483310, year = {2021}, author = {Okrasińska, A and Bokus, A and Duk, K and Gęsiorska, A and Sokołowska, B and Miłobędzka, A and Wrzosek, M and Pawłowska, J}, title = {New Endohyphal Relationships between Mucoromycota and Burkholderiaceae Representatives.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {7}, pages = {}, pmid = {33483310}, issn = {1098-5336}, mesh = {Burkholderiaceae/*physiology ; Fungi/*physiology ; Hyphae/*physiology ; In Situ Hybridization, Fluorescence ; Polymerase Chain Reaction ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; }, abstract = {Mucoromycota representatives are known to harbor two types of endohyphal bacteria (EHB)-Burkholderia-related endobacteria (BRE) and Mycoplasma-related endobacteria (MRE). While both BRE and MRE occur in fungi representing all subphyla of Mucoromycota, their distribution is not well studied. Therefore, it is difficult to resolve the evolutionary history of these associations in favor of one of the following two alternative hypotheses explaining their origin: "early invasion" and "late invasion." Our main goal was to fill this knowledge gap by surveying Mucoromycota fungi for the presence of EHB. We screened 196 fungal strains from 16 genera using a PCR-based approach to detect bacterial 16S rRNA genes, complemented with fluorescence in situ hybridization (FISH) imaging to confirm the presence of bacteria within the hyphae. We detected Burkholderiaceae in ca. 20% of fungal strains. Some of these bacteria clustered phylogenetically with previously described BRE clades, whereas others grouped with free-living Paraburkholderia Importantly, the latter were detected in Umbelopsidales, which previously were not known to harbor endobacteria. Our results suggest that this group of EHB is recruited from the environment, supporting the late invasion scenario. This pattern complements the early invasion scenario apparent in the BRE clade of EHB.IMPORTANCE Bacteria living within fungal hyphae present an example of one of the most intimate relationships between fungi and bacteria. Even though there are several well-described examples of such partnerships, their prevalence within the fungal kingdom remains unknown. Our study focused on early divergent terrestrial fungi in the phylum Mucoromycota. We found that ca. 20% of the strains tested harbored bacteria from the family Burkholderiaceae Not only did we confirm the presence of bacteria from previously described endosymbiont clades, we also identified a new group of endohyphal Burkholderiaceae representing the genus Paraburkholderia We established that more than half of the screened Umbelopsis strains were positive for bacteria from this new group. We also determined that, while previously described BRE codiverged with their fungal hosts, Paraburkholderia symbionts did not.}, }
@article {pmid33470507, year = {2021}, author = {Castelli, M and Lanzoni, O and Nardi, T and Lometto, S and Modeo, L and Potekhin, A and Sassera, D and Petroni, G}, title = {'Candidatus Sarmatiella mevalonica' endosymbiont of the ciliate Paramecium provides insights on evolutionary plasticity among Rickettsiales.}, journal = {Environmental microbiology}, volume = {23}, number = {3}, pages = {1684-1701}, doi = {10.1111/1462-2920.15396}, pmid = {33470507}, issn = {1462-2920}, mesh = {*Paramecium ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiales/genetics ; Symbiosis/genetics ; }, abstract = {Members of the bacterial order Rickettsiales are obligatorily associated with a wide range of eukaryotic hosts. Their evolutionary trajectories, in particular concerning the origin of shared or differential traits among distant sub-lineages, are still poorly understood. Here, we characterized a novel Rickettsiales bacterium associated with the ciliate Paramecium tredecaurelia and phylogenetically related to the Rickettsia genus. Its genome encodes significant lineage-specific features, chiefly the mevalonate pathway gene repertoire, involved in isoprenoid precursor biosynthesis. Not only this pathway has never been described in Rickettsiales, it also is very rare among bacteria, though typical in eukaryotes, thus likely representing a horizontally acquired trait. The presence of these genes could enable an efficient exploitation of host-derived intermediates for isoprenoid synthesis. Moreover, we hypothesize the reversed reactions could have replaced canonical pathways for producing acetyl-CoA, essential for phospholipid biosynthesis. Additionally, we detected phylogenetically unrelated mevalonate pathway genes in metagenome-derived Rickettsiales sequences, likely indicating evolutionary convergent effects of independent horizontal gene transfer events. Accordingly, convergence, involving both gene acquisitions and losses, is highlighted as a relevant evolutionary phenomenon in Rickettsiales, possibly favoured by plasticity and comparable lifestyles, representing a potentially hidden origin of other more nuanced similarities among sub-lineages.}, }
@article {pmid33468211, year = {2021}, author = {Beard, D and Stannard, HJ and Old, JM}, title = {Morphological identification of ticks and molecular detection of tick-borne pathogens from bare-nosed wombats (Vombatus ursinus).}, journal = {Parasites &amp; vectors}, volume = {14}, number = {1}, pages = {60}, pmid = {33468211}, issn = {1756-3305}, mesh = {Animals ; Animals, Wild/parasitology ; Bacteria/classification/*genetics/isolation &amp; purification/pathogenicity ; Female ; Male ; Marsupialia/*parasitology ; New South Wales/epidemiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Tick Infestations/epidemiology/*veterinary ; Ticks/*anatomy &amp; histology/classification ; }, abstract = {BACKGROUND: Ticks are obligate haematophagous ectoparasites of vertebrate hosts and transmit the widest range of pathogenic organisms of any arthropod vector. Seven tick species are known to feed on bare-nosed wombats (Vombatus ursinus), in addition to the highly prevalent Sarcoptes scabiei mite which causes fatal sarcoptic mange in most bare-nosed wombat populations. Little is known about the pathogens carried by most wombat ticks or how they may impact wombats and wombat handlers.<br><br>METHODS: Wombat ticks were sourced from wildlife hospitals and sanctuaries across Australia and identified to species level using taxonomic keys. Genomic DNA was extracted from a subsample, and following the amplification of the bacterial 16S rRNA gene V3-V4 hypervariable region, next-generation sequencing (NGS) on the Illumina MiSeq platform was used to assess the microbial composition.<br><br>RESULTS: A total of 447 tick specimens were collected from 47 bare-nosed wombats between January 2019 and January 2020. Five species of ticks were identified comprising wombat tick Bothriocroton auruginans (n = 420), wallaby tick Haemaphysalis bancrofti (n = 8), bush tick Haemaphysalis longicornis (n = 3), common marsupial tick Ixodes tasmani (n = 12), and Australian paralysis tick Ixodes holocyclus (n = 4). Tick infestations ranged from one to 73 ticks per wombat. The wombat tick was the most prevalent tick species comprising 94% of the total number of samples and was present on 97.9% (46/47) of wombat hosts. NGS results revealed the 16S rRNA gene diversity profile was predominantly Proteobacteria (55.1%) followed by Firmicutes (21.9%) and Actinobacteria (18.4%). A species of Coxiella sharing closest sequence identity to Coxiella burnetii (99.07%), was detected in 72% of B. auruginans and a Rickettsiella endosymbiont dominated the bacterial profile for I. tasmani.<br><br>CONCLUSIONS: A new host record for H. longicornis is the bare-nosed wombat. One adult male and two engorged adult female specimens were found on an adult male wombat from Coolagolite in New South Wales, and more specimens should be collected to confirm this host record. The most prevalent tick found on bare-nosed wombats was B. auruginans, confirming previous records. Analysis of alpha-diversity showed high variability across both sample locations and instars, similar to previous studies. The detection of various Proteobacteria in this study highlights the high bacterial diversity in native Australian ticks.}, }
@article {pmid33468006, year = {2021}, author = {Yoshida, K and Sanada-Morimura, S and Huang, SH and Tokuda, M}, title = {Silence of the killers: discovery of male-killing suppression in a rearing strain of the small brown planthopper, Laodelphax striatellus.}, journal = {Proceedings. Biological sciences}, volume = {288}, number = {1943}, pages = {20202125}, pmid = {33468006}, issn = {1471-2954}, mesh = {Animals ; Female ; *Hemiptera/genetics ; Male ; Sex Ratio ; *Spiroplasma ; *Wolbachia ; }, abstract = {According to evolutionary theory, sex ratio distortions caused by reproductive parasites such as Wolbachia and Spiroplasma are predicted to be rapidly normalized by the emergence of host nuclear suppressors. However, such processes in the evolutionary arms race are difficult to observe because sex ratio biases will be promptly hidden and become superficially unrecognizable. The evolution of genetic suppressors has been reported in just two insect species so far. In the small brown planthopper, Laodelphax striatellus, female-biases caused by Spiroplasma, which is a 'late' male-killer, have been found in some populations. During the continuous rearing of L. striatellus, we noted that a rearing strain had a 1 : 1 sex ratio even though it harboured Spiroplasma. Through introgression crossing experiments with a strain lacking suppressors, we revealed that the L. striatellus strain had the zygotic male-killing suppressor acting as a dominant trait. The male-killing phenotype was hidden by the suppressor even though Spiroplasma retained its male-killing ability. This is the first study to demonstrate the existence of a late male-killing suppressor and its mode of inheritance. Our results, together with those of previous studies, suggest that the inheritance modes of male-killing suppressors are similar regardless of insect order or early or late male killing.}, }
@article {pmid33454808, year = {2021}, author = {Takano, SI and Gotoh, Y and Hayashi, T}, title = {"Candidatus Mesenet longicola": Novel Endosymbionts of Brontispa longissima that Induce Cytoplasmic Incompatibility.}, journal = {Microbial ecology}, volume = {82}, number = {2}, pages = {512-522}, pmid = {33454808}, issn = {1432-184X}, mesh = {Animals ; *Coleoptera ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Intracellular bacteria that are mainly transmitted maternally affect their arthropod hosts' biology in various ways. One such effect is known as cytoplasmic incompatibility (CI), and three bacterial species are known to induce CI: Wolbachia, Cardinium hertigii, and a recently found alphaproteobacterial symbiont. To clarify the taxonomic status and provide the foundation for future studies to reveal CI mechanisms and other phenotypes, we investigated genetic and morphological properties of the third CI inducer that we have previously reported inducing CI in the coconut beetle Brontispa longissima. The draft genome of the bacteria was obtained from the oocytes of two isofemale lines of B. longissima infected with the bacteria: one from Japan (GL2) and the other from Vietnam (L5). Genome features of the symbionts (sGL2 and sL5) were highly similar, showing 1.3 Mb in size, 32.1% GC content, and 99.83% average nucleotide sequence. A phylogenetic study based on 43 universal and single-copy phylogenetic marker genes indicates that they formed a distinct clade in the family Anaplasmataceae. 16S rRNA gene sequences indicate that they are different from the closest known relatives, at least at the genus level. Therefore, we propose a new genus and species, "Candidatus Mesenet longicola", for the symbionts of B. longissima. Morphological analyses showed that Ca. M. longicola is an intracellular bacterium that is ellipsoidal to rod-shaped and 0.94 ± 0.26 μm (mean ± SD) in length, and accumulated in the anterior part of the oocyte. Candidates for the Ca. M. longicola genes responsible for CI induction are also described.}, }
@article {pmid33452833, year = {2021}, author = {Jiang, J and Dehesh, K}, title = {Plastidial retrograde modulation of light and hormonal signaling: an odyssey.}, journal = {The New phytologist}, volume = {230}, number = {3}, pages = {931-937}, doi = {10.1111/nph.17192}, pmid = {33452833}, issn = {1469-8137}, support = {R01 GM107311/GM/NIGMS NIH HHS/United States ; }, mesh = {*Arabidopsis/metabolism ; *Arabidopsis Proteins/metabolism ; Chloroplasts/metabolism ; DNA-Binding Proteins ; Gene Expression Regulation, Plant ; Plastids/metabolism ; Signal Transduction ; }, abstract = {The transition from an engulfed autonomous unicellular photosynthetic bacterium to a semiautonomous endosymbiont plastid was accompanied by the transfer of genetic material from the endosymbiont to the nuclear genome of the host, followed by the establishment of plastid-to-nucleus (retrograde) signaling. The retrograde coordinated activities of the two subcellular genomes ensure chloroplast biogenesis and function as the photosynthetic hub and sensing and signaling center that tailors growth-regulating and adaptive processes. This review specifically focuses on the current knowledge of selected stress-induced retrograde signals, genomes uncoupled 1 (GUN1), methylerythritol cyclodiphosphate (MEcPP), apocarotenoid and β-cyclocitral, and 3'-phosphoadenosine 5'-phosphate (PAP), which evolved to establish the photoautotrophic lifestyle and are instrumental in the integration of light and hormonal signaling networks to ultimately fashion adaptive responses in an ever-changing environment.}, }
@article {pmid33452479, year = {2021}, author = {Midha, S and Rigden, DJ and Siozios, S and Hurst, GDD and Jackson, AP}, title = {Bodo saltans (Kinetoplastida) is dependent on a novel Paracaedibacter-like endosymbiont that possesses multiple putative toxin-antitoxin systems.}, journal = {The ISME journal}, volume = {15}, number = {6}, pages = {1680-1694}, pmid = {33452479}, issn = {1751-7370}, mesh = {*Alphaproteobacteria ; Eukaryota ; *Kinetoplastida ; Phylogeny ; Symbiosis ; *Toxin-Antitoxin Systems ; }, abstract = {Bacterial endosymbiosis has been instrumental in eukaryotic evolution, and includes both mutualistic, dependent and parasitic associations. Here we characterize an intracellular bacterium inhabiting the flagellated protist Bodo saltans (Kinetoplastida). We present a complete bacterial genome comprising a 1.39 Mb circular chromosome with 40.6% GC content. Fluorescent in situ hybridisation confirms that the endosymbiont is located adjacent to the nuclear membrane, and a detailed model of its intracellular niche is generated using serial block-face scanning electron microscopy. Phylogenomic analysis shows that the endosymbiont belongs to the Holosporales, most closely related to other α-proteobacterial endosymbionts of ciliates and amoebae. Comparative genomics indicates that it has a limited metabolism and is nutritionally host-dependent. However, the endosymbiont genome does encode diverse symbiont-specific secretory proteins, including a type VI secretion system and three separate toxin-antitoxin systems. We show that these systems are actively transcribed and hypothesize they represent a mechanism by which B. saltans becomes addicted to its endosymbiont. Consistent with this idea, attempts to cure Bodo of endosymbionts led to rapid and uniform cell death. This study adds kinetoplastid flagellates to ciliates and amoebae as hosts of Paracaedibacter-like bacteria, suggesting that these antagonistic endosymbioses became established very early in Eukaryotic evolution.}, }
@article {pmid33436511, year = {2021}, author = {Chung, M and Adkins, RS and Mattick, JSA and Bradwell, KR and Shetty, AC and Sadzewicz, L and Tallon, LJ and Fraser, CM and Rasko, DA and Mahurkar, A and Dunning Hotopp, JC}, title = {FADU: a Quantification Tool for Prokaryotic Transcriptomic Analyses.}, journal = {mSystems}, volume = {6}, number = {1}, pages = {}, pmid = {33436511}, issn = {2379-5077}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, abstract = {Quantification tools for RNA sequencing (RNA-Seq) analyses are often designed and tested using human transcriptomics data sets, in which full-length transcript sequences are well annotated. For prokaryotic transcriptomics experiments, full-length transcript sequences are seldom known, and coding sequences must instead be used for quantification steps in RNA-Seq analyses. However, operons confound accurate quantification of coding sequences since a single transcript does not necessarily equate to a single gene. Here, we introduce FADU (Feature Aggregate Depth Utility), a quantification tool designed specifically for prokaryotic RNA-Seq analyses. FADU assigns partial count values proportional to the length of the fragment overlapping the target feature. To assess the ability of FADU to quantify genes in prokaryotic transcriptomics analyses, we compared its performance to those of eXpress, featureCounts, HTSeq, kallisto, and Salmon across three paired-end read data sets of (i) Ehrlichia chaffeensis, (ii) Escherichia coli, and (iii) the Wolbachia endosymbiont wBm. Across each of the three data sets, we find that FADU can more accurately quantify operonic genes by deriving proportional counts for multigene fragments within operons. FADU is available at https://github.com/IGS/FADUIMPORTANCE Most currently available quantification tools for transcriptomics analyses have been designed for human data sets, in which full-length transcript sequences, including the untranslated regions, are well annotated. In most prokaryotic systems, full-length transcript sequences have yet to be characterized, leading to prokaryotic transcriptomics analyses being performed based on only the coding sequences. In contrast to eukaryotes, prokaryotes contain polycistronic transcripts, and when genes are quantified based on coding sequences instead of transcript sequences, this leads to an increased abundance of improperly assigned ambiguous multigene fragments, specifically those mapping to multiple genes in operons. Here, we describe FADU, a quantification tool for prokaryotic RNA-Seq analyses designed to assign proportional counts with the purpose of better quantifying operonic genes while minimizing the pitfalls associated with improperly assigning fragment counts from ambiguous transcripts.}, }
@article {pmid33436431, year = {2021}, author = {Deehan, M and Lin, W and Blum, B and Emili, A and Frydman, H}, title = {Intracellular Density of Wolbachia Is Mediated by Host Autophagy and the Bacterial Cytoplasmic Incompatibility Gene cifB in a Cell Type-Dependent Manner in Drosophila melanogaster.}, journal = {mBio}, volume = {12}, number = {1}, pages = {}, pmid = {33436431}, issn = {2150-7511}, mesh = {Animals ; Autophagy/*genetics/physiology ; Autophagy-Related Protein-1 Homolog ; Bacterial Proteins/metabolism ; Cytoplasm/*microbiology ; Cytosol ; Drosophila Proteins ; Drosophila melanogaster/genetics/immunology/*microbiology ; Female ; Gene Knockdown Techniques ; Genes, Bacterial/*genetics ; Host-Pathogen Interactions/*genetics/immunology ; Immunity, Innate ; Male ; Reproduction ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Autophagy is an intracellular degradation pathway involved in innate immunity. Pathogenic bacteria have evolved several mechanisms to escape degradation or exploit autophagy to acquire host nutrients. In the case of endosymbionts, which often have commensal or mutualistic interactions with the host, autophagy is not well characterized. We utilized tissue-specific autophagy mutants to determine if Wolbachia, a vertically transmitted obligate endosymbiont of Drosophila melanogaster, is regulated by autophagy in somatic and germ line cell types. Our analysis revealed core autophagy proteins Atg1 and Atg8 and a selective autophagy-specific protein Ref(2)p negatively regulate Wolbachia in the hub, a male gonad somatic cell type. Furthermore, we determined that the Wolbachia effector protein, CifB, modulates autophagy-Wolbachia interactions, identifying a new host-related pathway which these bacterial proteins interact with. In the female germ line, the cell type necessary for inheritance of Wolbachia through vertical transmission, we discovered that bulk autophagy mediated by Atg1 and Atg8 positively regulates Wolbachia density, whereas Ref(2)p had no effect. Global metabolomics of fly ovaries deficient in germ line autophagy revealed reduced lipid and carbon metabolism, implicating metabolites from these pathways as positive regulators of Wolbachia Our work provides further understanding of how autophagy affects bacteria in a cell type-dependent manner.IMPORTANCE Autophagy is a eukaryotic intracellular degradation pathway which can act as an innate immune response to eliminate pathogens. Conversely, pathogens can evolve proteins which modulate the autophagy pathway to subvert degradation and establish an infection. Wolbachia, a vertically transmitted obligate endosymbiont which infects up to 40% of insect species, is negatively regulated by autophagy in whole animals, but the specific molecular mechanism and tissue which govern this interaction remain unknown. Our studies use cell type-specific autophagy mutants to reveal that Wolbachia is negatively regulated by selective autophagy in the soma, while nonselective autophagy positively regulates Wolbachia in the female germ line. These data provide evidence that cell type can drive different basal autophagy programs which modulate intracellular microbes differently. Additionally, we identified that the Wolbachia effector CifB acts in the selective autophagy pathway to aid in intracellular bacterial survival, providing a new function for CifB beyond its previously identified role in reproductive manipulation.}, }
@article {pmid33432342, year = {2021}, author = {Harada, R and Inagaki, Y}, title = {Phage Origin of Mitochondrion-Localized Family A DNA Polymerases in Kinetoplastids and Diplonemids.}, journal = {Genome biology and evolution}, volume = {13}, number = {2}, pages = {}, pmid = {33432342}, issn = {1759-6653}, mesh = {Bacteriophages/enzymology/*genetics ; DNA-Directed DNA Polymerase/classification/*genetics ; Euglenozoa/enzymology/*genetics ; *Gene Transfer, Horizontal ; Kinetoplastida/enzymology/*genetics ; Mitochondria/enzymology/genetics ; Phylogeny ; }, abstract = {Mitochondria retain their own genomes as other bacterial endosymbiont-derived organelles. Nevertheless, no protein for DNA replication and repair is encoded in any mitochondrial genomes (mtDNAs) assessed to date, suggesting that the nucleus primarily governs the maintenance of mtDNA. As the proteins of diverse evolutionary origins occupy a large proportion of the current mitochondrial proteomes, we anticipate finding the same evolutionary trend in the nucleus-encoded machinery for mtDNA maintenance. Indeed, none of the DNA polymerases (DNAPs) in the mitochondrial endosymbiont, a putative α-proteobacterium, seemingly had been inherited by their descendants (mitochondria), as none of the known types of mitochondrion-localized DNAP showed a specific affinity to the α-proteobacterial DNAPs. Nevertheless, we currently have no concrete idea of how and when the known types of mitochondrion-localized DNAPs emerged. We here explored the origins of mitochondrion-localized DNAPs after the improvement of the samplings of DNAPs from bacteria and phages/viruses. Past studies have revealed that a set of mitochondrion-localized DNAPs in kinetoplastids and diplonemids, namely PolIB, PolIC, PolID, PolI-Perk1/2, and PolI-dipl (henceforth designated collectively as "PolIBCD+") have emerged from a single DNAP. In this study, we recovered an intimate connection between PolIBCD+ and the DNAPs found in a particular group of phages. Thus, the common ancestor of kinetoplastids and diplonemids most likely converted a laterally acquired phage DNAP into a mitochondrion-localized DNAP that was ancestral to PolIBCD+. The phage origin of PolIBCD+ hints at a potentially large contribution of proteins acquired via nonvertical processes to the machinery for mtDNA maintenance in kinetoplastids and diplonemids.}, }
@article {pmid33430009, year = {2021}, author = {Badji, CA and Sol-Mochkovitch, Z and Fallais, C and Sochard, C and Simon, JC and Outreman, Y and Anton, S}, title = {Alarm Pheromone Responses Depend on Genotype, but Not on the Presence of Facultative Endosymbionts in the Pea Aphid Acyrthosiphon pisum.}, journal = {Insects}, volume = {12}, number = {1}, pages = {}, pmid = {33430009}, issn = {2075-4450}, abstract = {Aphids use an alarm pheromone, E-β farnesene (EBF), to warn conspecifics of potential danger. The antennal sensitivity and behavioural escape responses to EBF can be influenced by different factors. In the pea aphid, Acyrthosiphon pisum, different biotypes are adapted to different legume species, and within each biotype, different genotypes exist, which can carry or not Hamiltonella defensa, a bacterial symbiont that can confer protection against natural enemies. We investigate here the influence of the aphid genotype and symbiotic status on the escape behaviour using a four-way olfactometer and antennal sensitivity for EBF using electroantennograms (EAGs). Whereas the investigated three genotypes from two biotypes showed significantly different escape and locomotor behaviours in the presence of certain EBF doses, the infection with H. defensa did not significantly modify the escape behaviour and only marginally influenced the locomotor behaviour at high doses of EBF. Dose-response curves of EAG amplitudes after stimulation with EBF differed significantly between aphid genotypes in correlation with behavioural differences, whereas antennal sensitivity to EBF did not change significantly as a function of the symbiotic status. The protective symbiont H. defensa does thus not modify the olfactory sensitivity to the alarm pheromone. How EBF sensitivity is modified between genotypes or biotypes remains to be investigated.}, }
@article {pmid33424811, year = {2020}, author = {Thongprem, P and Evison, SEF and Hurst, GDD and Otti, O}, title = {Transmission, Tropism, and Biological Impacts of Torix Rickettsia in the Common Bed Bug Cimex lectularius (Hemiptera: Cimicidae).}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {608763}, pmid = {33424811}, issn = {1664-302X}, abstract = {The torix group of Rickettsia have been recorded from a wide assemblage of invertebrates, but details of transmission and biological impacts on the host have rarely been established. The common bed bug (Cimex lectularius) is a hemipteran insect which lives as an obligatory hematophagous pest of humans and is host to a primary Wolbachia symbiont and two facultative symbionts, a BEV-like symbiont, and a torix group Rickettsia. In this study, we first note the presence of a single Rickettsia strain in multiple laboratory bed bug isolates derived from Europe and Africa. Importantly, we discovered that the Rickettsia has segregated in two laboratory strains, providing infected and uninfected isogenic lines for study. Crosses with these lines established transmission was purely maternal. Fluorescence in-situ hybridization analysis indicates Rickettsia infection in oocytes, bacteriomes, and other somatic tissues. We found no evidence that Rickettsia infection was associated with sex ratio distortion activity, but Rickettsia infected individuals developed from first instar to adult more slowly. The impact of Rickettsia on fecundity and fertility resulted in infected females producing fewer fertile eggs. However, we could not find any evidence for cytoplasmic incompatibility associated with Rickettsia presence. These data imply the existence of an unknown benefit to C. lectularius carrying Rickettsia that awaits further research.}, }
@article {pmid33420046, year = {2021}, author = {Hermes, C and Richarz, R and Wirtz, DA and Patt, J and Hanke, W and Kehraus, S and Voß, JH and Küppers, J and Ohbayashi, T and Namasivayam, V and Alenfelder, J and Inoue, A and Mergaert, P and Gütschow, M and Müller, CE and Kostenis, E and König, GM and Crüsemann, M}, title = {Thioesterase-mediated side chain transesterification generates potent Gq signaling inhibitor FR900359.}, journal = {Nature communications}, volume = {12}, number = {1}, pages = {144}, pmid = {33420046}, issn = {2041-1723}, mesh = {Animals ; Bacterial Proteins/biosynthesis/chemistry/isolation &amp; purification/*pharmacology ; Chromobacterium/*metabolism ; Depsipeptides/biosynthesis/chemistry/isolation &amp; purification/*pharmacology ; Esterases/metabolism ; GTP-Binding Protein alpha Subunits, Gq-G11/*antagonists &amp; inhibitors/genetics/metabolism ; Gene Knockout Techniques ; HEK293 Cells ; Hemiptera ; Humans ; Molecular Docking Simulation ; Molecular Structure ; Signal Transduction/drug effects/genetics ; }, abstract = {The potent and selective Gq protein inhibitor depsipeptide FR900359 (FR), originally discovered as the product of an uncultivable plant endosymbiont, is synthesized by a complex biosynthetic system comprising two nonribosomal peptide synthetase (NRPS) assembly lines. Here we characterize a cultivable bacterial FR producer, enabling detailed investigations into biosynthesis and attachment of the functionally important FR side chain. We reconstitute side chain assembly by the monomodular NRPS FrsA and the non-heme monooxygenase FrsH, and characterize intermolecular side chain transesterification to the final macrocyclic intermediate FR-Core, mediated by the FrsA thioesterase domain. We harness FrsA substrate promiscuity to generate FR analogs with altered side chains and demonstrate indispensability of the FR side chain for efficient Gq inhibition by comparative bioactivity, toxicity and docking studies. Finally, evolution of FR and side chain biosynthesis is discussed based on bioinformatics analyses. Side chain transesterification boosts potency and target affinity of selective Gq inhibitor natural products.}, }
@article {pmid33419736, year = {2021}, author = {Shore, A and Day, RD and Stewart, JA and Burge, CA}, title = {Dichotomy between Regulation of Coral Bacterial Communities and Calcification Physiology under Ocean Acidification Conditions.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {6}, pages = {}, pmid = {33419736}, issn = {1098-5336}, mesh = {Animals ; Anthozoa/*microbiology/*physiology ; Bacteria/classification/isolation &amp; purification ; *Calcification, Physiologic ; Hydrogen-Ion Concentration ; Oceans and Seas ; Seawater/*chemistry ; }, abstract = {Ocean acidification (OA) threatens the growth and function of coral reef ecosystems. A key component to coral health is the microbiome, but little is known about the impact of OA on coral microbiomes. A submarine CO2 vent at Maug Island in the Northern Mariana Islands provides a natural pH gradient to investigate coral responses to long-term OA conditions. Three coral species (Pocillopora eydouxi, Porites lobata, and Porites rus) were sampled from three sites where the mean seawater pH is 8.04, 7.98, and 7.94. We characterized coral bacterial communities (using 16S rRNA gene sequencing) and determined pH of the extracellular calcifying fluid (ECF) (using skeletal boron isotopes) across the seawater pH gradient. Bacterial communities of both Porites species stabilized (decreases in community dispersion) with decreased seawater pH, coupled with large increases in the abundance of Endozoicomonas, an endosymbiont. P. lobata experienced a significant decrease in ECF pH near the vent, whereas P. rus experienced a trending decrease in ECF pH near the vent. In contrast, Pocillopora exhibited bacterial community destabilization (increases in community dispersion), with significant decreases in Endozoicomonas abundance, while its ECF pH remained unchanged across the pH gradient. Our study shows that OA has multiple consequences on Endozoicomonas abundance and suggests that Endozoicomonas abundance may be an indicator of coral response to OA. We reveal an interesting dichotomy between two facets of coral physiology (regulation of bacterial communities and regulation of calcification), highlighting the importance of multidisciplinary approaches to understanding coral health and function in a changing ocean.IMPORTANCE Ocean acidification (OA) is a consequence of anthropogenic CO2 emissions that is negatively impacting marine ecosystems such as coral reefs. OA affects many aspects of coral physiology, including growth (i.e., calcification) and disrupting associated bacterial communities. Coral-associated bacteria are important for host health, but it remains unclear how coral-associated bacterial communities will respond to future OA conditions. We document changes in coral-associated bacterial communities and changes to calcification physiology with long-term exposure to decreases in seawater pH that are environmentally relevant under midrange IPCC emission scenarios (0.1 pH units). We also find species-specific responses that may reflect different responses to long-term OA. In Pocillopora, calcification physiology was highly regulated despite changing seawater conditions. In Porites spp., changes in bacterial communities do not reflect a breakdown of coral-bacterial symbiosis. Insights into calcification and host-microbe interactions are critical to predicting the health and function of different coral taxa to future OA conditions.}, }
@article {pmid33419303, year = {2020}, author = {Lacerna, NM and Ramones, CMV and Robes, JMD and Picart, MRD and Tun, JO and Miller, BW and Haygood, MG and Schmidt, EW and Salvador-Reyes, LA and Concepcion, GP}, title = {Inhibition of Biofilm Formation by Modified Oxylipins from the Shipworm Symbiont Teredinibacter turnerae.}, journal = {Marine drugs}, volume = {18}, number = {12}, pages = {}, pmid = {33419303}, issn = {1660-3397}, mesh = {Animals ; Biofilms/*drug effects/growth &amp; development ; Bivalvia ; *Gammaproteobacteria/chemistry ; Microbial Sensitivity Tests/methods ; Oxylipins/isolation &amp; purification/*pharmacology ; Symbiosis/*drug effects/physiology ; }, abstract = {The bioactivity-guided purification of the culture broth of the shipworm endosymbiont Teredinibacter turnerae strain 991H.S.0a.06 yielded a new fatty acid, turneroic acid (1), and two previously described oxylipins (2-3). Turneroic acid (1) is an 18-carbon fatty acid decorated by a hydroxy group and an epoxide ring. Compounds 1-3 inhibited bacterial biofilm formation in Staphylococcus epidermidis, while only 3 showed antimicrobial activity against planktonic S. epidermidis. Comparison of the bioactivity of 1-3 with structurally related compounds indicated the importance of the epoxide moiety for selective and potent biofilm inhibition.}, }
@article {pmid33418339, year = {2021}, author = {Díaz-Sánchez, S and Fernández, AM and Habela, MA and Calero-Bernal, R and de Mera, IGF and de la Fuente, J}, title = {Microbial community of Hyalomma lusitanicum is dominated by Francisella-like endosymbiont.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {2}, pages = {101624}, doi = {10.1016/j.ttbdis.2020.101624}, pmid = {33418339}, issn = {1877-9603}, mesh = {Animals ; Francisella/*physiology ; Ixodidae/*microbiology ; *Microbiota ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Spain ; *Symbiosis ; }, abstract = {Exploring tick associations with complex microbial communities and single-microbial partners, especially intracellular symbionts, has become crucial to understand tick biology. Of particular interest are the underlying interactions with biological consequences i.e. tick fitness, vector competence. In this study, we first sequenced the 16S rRNA bacterial phylogenetic marker in adult male ticks of Hyalomma lusitanicum collected from 5 locations in the province of Cáceres to explore the composition of its microbial community. Overall, 16S rRNA sequencing results demonstrated that the microbial community of H. lusitanicum is mostly dominated by Francisella-like endosymbionts (FLEs) (ranging from 52% to 99% of relative abundance) suggesting it is a key taxon within the microbial community and likely a primary endosymbiont. However, further research is required to explore the mechanisms underlying the interaction between FLEs and H. lusitanicum.}, }
@article {pmid33406151, year = {2021}, author = {Chevignon, G and Foray, V and Pérez-Jiménez, MM and Libro, S and Chung, M and Foster, JM and Landmann, F}, title = {Dual RNAseq analyses at soma and germline levels reveal evolutionary innovations in the elephantiasis-agent Brugia malayi, and adaptation of its Wolbachia endosymbionts.}, journal = {PLoS neglected tropical diseases}, volume = {15}, number = {1}, pages = {e0008935}, pmid = {33406151}, issn = {1935-2735}, mesh = {Animals ; *Biological Evolution ; Brugia malayi/*genetics ; Caenorhabditis elegans ; *Carisoprodol ; Elephantiasis/*genetics ; Elephantiasis, Filarial/genetics ; Female ; Gene Expression ; Genome ; *Germ Cells ; Humans ; Oogenesis ; Sequence Analysis, RNA ; Symbiosis ; Wolbachia/physiology ; }, abstract = {Brugia malayi is a human filarial nematode responsible for elephantiasis, a debilitating condition that is part of a broader spectrum of diseases called filariasis, including lymphatic filariasis and river blindness. Almost all filarial nematode species infecting humans live in mutualism with Wolbachia endosymbionts, present in somatic hypodermal tissues but also in the female germline which ensures their vertical transmission to the nematode progeny. These α-proteobacteria potentially provision their host with essential metabolites and protect the parasite against the vertebrate immune response. In the absence of Wolbachia wBm, B. malayi females become sterile, and the filarial nematode lifespan is greatly reduced. In order to better comprehend this symbiosis, we investigated the adaptation of wBm to the host nematode soma and germline, and we characterized these cellular environments to highlight their specificities. Dual RNAseq experiments were performed at the tissue-specific and ovarian developmental stage levels, reaching the resolution of the germline mitotic proliferation and meiotic differentiation stages. We found that most wBm genes, including putative effectors, are not differentially regulated between infected tissues. However, two wBm genes involved in stress responses are upregulated in the hypodermal chords compared to the germline, indicating that this somatic tissue represents a harsh environment to which wBm have adapted. A comparison of the B. malayi and C. elegans germline transcriptomes reveals a poor conservation of genes involved in the production of oocytes, with the filarial germline proliferative zone relying on a majority of genes absent from C. elegans. The first orthology map of the B. malayi genome presented here, together with tissue-specific expression enrichment analyses, indicate that the early steps of oogenesis are a developmental process involving genes specific to filarial nematodes, that likely result from evolutionary innovations supporting the filarial parasitic lifestyle.}, }
@article {pmid33406097, year = {2021}, author = {Makhulu, EE and Villinger, J and Adunga, VO and Jeneby, MM and Kimathi, EM and Mararo, E and Oundo, JW and Musa, AA and Wambua, L}, title = {Tsetse blood-meal sources, endosymbionts and trypanosome-associations in the Maasai Mara National Reserve, a wildlife-human-livestock interface.}, journal = {PLoS neglected tropical diseases}, volume = {15}, number = {1}, pages = {e0008267}, pmid = {33406097}, issn = {1935-2735}, mesh = {Animals ; Animals, Wild/*parasitology ; Artiodactyla/parasitology ; Blood ; Buffaloes/parasitology ; Ecosystem ; Elephants/parasitology ; Enterobacteriaceae ; Humans ; Insect Vectors/*parasitology ; Kenya ; Livestock/*parasitology ; Polymerase Chain Reaction ; Symbiosis/*physiology ; Trypanosoma/genetics/*physiology ; Trypanosoma vivax ; Trypanosomiasis, African/parasitology ; Tsetse Flies/*parasitology ; }, abstract = {African trypanosomiasis (AT) is a neglected disease of both humans and animals caused by Trypanosoma parasites, which are transmitted by obligate hematophagous tsetse flies (Glossina spp.). Knowledge on tsetse fly vertebrate hosts and the influence of tsetse endosymbionts on trypanosome presence, especially in wildlife-human-livestock interfaces, is limited. We identified tsetse species, their blood-meal sources, and correlations between endosymbionts and trypanosome presence in tsetse flies from the trypanosome-endemic Maasai Mara National Reserve (MMNR) in Kenya. Among 1167 tsetse flies (1136 Glossina pallidipes, 31 Glossina swynnertoni) collected from 10 sampling sites, 28 (2.4%) were positive by PCR for trypanosome DNA, most (17/28) being of Trypanosoma vivax species. Blood-meal analyses based on high-resolution melting analysis of vertebrate cytochrome c oxidase 1 and cytochrome b gene PCR products (n = 354) identified humans as the most common vertebrate host (37%), followed by hippopotamus (29.1%), African buffalo (26.3%), elephant (3.39%), and giraffe (0.84%). Flies positive for trypanosome DNA had fed on hippopotamus and buffalo. Tsetse flies were more likely to be positive for trypanosomes if they had the Sodalis glossinidius endosymbiont (P = 0.0002). These findings point to complex interactions of tsetse flies with trypanosomes, endosymbionts, and diverse vertebrate hosts in wildlife ecosystems such as in the MMNR, which should be considered in control programs. These interactions may contribute to the maintenance of tsetse populations and/or persistent circulation of African trypanosomes. Although the African buffalo is a key reservoir of AT, the higher proportion of hippopotamus blood-meals in flies with trypanosome DNA indicates that other wildlife species may be important in AT transmission. No trypanosomes associated with human disease were identified, but the high proportion of human blood-meals identified are indicative of human African trypanosomiasis risk. Our results add to existing data suggesting that Sodalis endosymbionts are associated with increased trypanosome presence in tsetse flies.}, }
@article {pmid33406079, year = {2021}, author = {Buysse, M and Duhayon, M and Cantet, F and Bonazzi, M and Duron, O}, title = {Vector competence of the African argasid tick Ornithodoros moubata for the Q fever agent Coxiella burnetii.}, journal = {PLoS neglected tropical diseases}, volume = {15}, number = {1}, pages = {e0009008}, pmid = {33406079}, issn = {1935-2735}, mesh = {Animals ; Arthropod Vectors/*microbiology ; Coxiella burnetii/*isolation &amp; purification ; Feces/microbiology ; Female ; Male ; Ornithodoros/*microbiology ; Q Fever/*transmission ; }, abstract = {Q fever is a widespread zoonotic disease caused by the intracellular bacterium Coxiella burnetii. While transmission is primarily but not exclusively airborne, ticks are usually thought to act as vectors on the basis of early microscopy studies. However, recent observations revealed that endosymbionts of ticks have been commonly misidentified as C. burnetii, calling the importance of tick-borne transmission into question. In this study, we re-evaluated the vector competence of the African soft tick Ornithodoros moubata for an avirulent strain of C. burnetii. To this end, we used an artificial feeding system to initiate infection of ticks, specific molecular tools to monitor further infections, and culture assays in axenic and cell media to check for the viability of C. burnetii excreted by ticks. We observed typical traits associated with vector competence: The exposure to an infected blood meal resulted in viable and persistent infections in ticks, trans-stadial transmissions of infection from nymphs to adults and the ability of adult ticks to transmit infectious C. burnetii. However, in contrast to early studies, we found that infection differed substantially between tick organs. In addition, while adult female ticks were infected, we did not observe C. burnetii in eggs, suggesting that transovarial transmission is not effective. Finally, we detected only a sporadic presence of C. burnetii DNA in tick faeces, but no living bacterium was further isolated in culture assays, suggesting that excretion in faeces is not a common mode of transmission in O. moubata.}, }
@article {pmid33399931, year = {2021}, author = {Shih, CM and Ophine, L and Chao, LL}, title = {Molecular Detection and Genetic Identification of Wolbachia Endosymbiont in Wild-Caught Culex quinquefasciatus (Diptera: Culicidae) Mosquitoes from Sumatera Utara, Indonesia.}, journal = {Microbial ecology}, volume = {81}, number = {4}, pages = {1064-1074}, pmid = {33399931}, issn = {1432-184X}, mesh = {Animals ; *Culex ; *Culicidae ; Female ; Indonesia ; Male ; Phylogeny ; *Wolbachia/genetics ; }, abstract = {The genetic identity of Wolbachia endosymbiont in wild-caught Culex quinquefasciatus was determined for the first time in Indonesia. A total of 314 Cx. quinquefasciatus were examined for Wolbachia by PCR assay targeting the Wolbachia surface protein (wsp) gene. The prevalence of Wolbachia infection was detected in 29.94% of Cx. specimens (45.86% female and 8.27% male). The group-specific infection was detected with an infection rate of 0.32%, 28.98%, and 0.64% in groups A, B, and A&amp;B, respectively. Phylogenetic analysis revealed all Wolbachia strains from Indonesia were genetically affiliated to the supergroup A and B with the high sequence similarity of 97.9-100% and 99.7-100%, respectively. Phylogenetic relationships can be easily distinguished by neighbor-joining analysis and were congruent by maximum likelihood method. The genetic distance (GD) values of intra- and inter-group analysis indicated a lower level (GD < 0.007 for group A and GD < 0.003 for group B) within the Indonesia strains and a higher level (GD > 1.125 for group A and GD > 1.129 for group B) as compared with other Wolbachia strains. Our results provide the first genetic identification of Wolbachia endosymbiont in Cx. quinquefasciatus collected from Indonesia, and the phylogenetic analysis revealed a new discovery of group A Wolbachia in wild-caught Cx. quinquefasciatus mosquitoes.}, }
@article {pmid33391879, year = {2020}, author = {Manullang, C and Millyaningrum, IH and Iguchi, A and Miyagi, A and Tanaka, Y and Nojiri, Y and Sakai, K}, title = {Responses of branching reef corals Acropora digitifera and Montipora digitata to elevated temperature and pCO2.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e10562}, pmid = {33391879}, issn = {2167-8359}, abstract = {Anthropogenic emission of CO2 into the atmosphere has been increasing exponentially, causing ocean acidification (OA) and ocean warming (OW). The "business-as-usual" scenario predicts that the atmospheric concentration of CO2 may exceed 1,000 µatm and seawater temperature may increase by up to 3 °C by the end of the 21[st] century. Increases in OA and OW may negatively affect the growth and survival of reef corals. In the present study, we separately examined the effects of OW and OA on the corals Acropora digitifera and Montipora digitata, which are dominant coral species occurring along the Ryukyu Archipelago, Japan, at three temperatures (28 °C, 30 °C, and 32 °C) and following four pCO2 treatments (400, 600, 800, and 1,000 µatm) in aquarium experiments. In the OW experiment, the calcification rate (p = 0.02), endosymbiont density, and maximum photosynthetic efficiency (Fv/Fm) (both p < 0.0001) decreased significantly at the highest temperature (32 °C) compared to those at the lower temperatures (28 °C and 30 °C) in both species. In the OA experiment, the calcification rate decreased significantly as pCO2 increased (p < 0.0001), whereas endosymbiont density, chlorophyll content, and Fv/Fm were not affected. The calcification rate of A. digitifera showed greater decreases from 30 °C to 32 °C than that of M. digitata. The calcification of the two species responded differently to OW and OA. These results suggest that A. digitifera is more sensitive to OW than M. digitata, whereas M. digitata is more sensitive to OA. Thus, differences in the sensitivity of the two coral species to OW and OA might be attributed to differences in the endosymbiont species and high calcification rates, respectively.}, }
@article {pmid33389546, year = {2021}, author = {Awad, M and Sharaf, A and Elrahman, TA and El-Saadany, HM and ElKraly, OA and Elnagdy, SM}, title = {The First Report for the Presence of Spiroplasma and Rickettsia in Red Palm Weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) in Egypt.}, journal = {Acta parasitologica}, volume = {66}, number = {2}, pages = {593-604}, pmid = {33389546}, issn = {1896-1851}, mesh = {Animals ; *Coleoptera ; Egypt ; Humans ; Phylogeny ; *Rickettsia/genetics ; *Spiroplasma ; *Weevils ; }, abstract = {PURPOSE: The study of the Red Palm Weevil (RPW), Rhynchophorus ferrugineus (Olivier), as an invasive pest of palm trees.<br><br>METHODS: In this study, 36 RPW individuals were collected from 6 different locations in Egypt. The presences of endosymbionts in the RPW individuals were assayed. The phylogenetic analysis of the RPW inhabiting Egypt was conducted using Cytochrome c oxidase sub-unit 1 (CO1) gene.<br><br>RESULTS: Spiroplasma was found, for the first time, in all individuals, while Rickettsia was found, for the first time, in individuals collected from only 3 of the 6 locations. Endosymbionts harbouring Egyptian RPW were closely related to those harbouring Diptera and\or Trombidiformes associated with palm trees. This may be due to horizontal transmission through palm sap or through ectoparasites living on the RPW. Finally, the phylogenetic analysis of the RPW inhabiting Egypt was conducted. The collected individuals were closely related to Saudi Arabia specimens collected from the eastern region. Thus, Saudi Arabia may be the origin of the RPW which invaded Egypt. Individuals from populations inhabiting the same geographical locations were closely related. This may be due to secondary invasion incidents that may have taken place through transportation of infested date palm trees and offshoots from infected to uninfected locations.<br><br>CONCLUSION: This study reports the first incidence for the presence and coexistence of Spiroplasma and Rickettsia in RPW collected from Egypt. In addition, it was found that the collected individuals of RPW were closely related to a Saudi haplotype. Thus, Saudi Arabia may be the origin of infection which invaded Egypt.}, }
@article {pmid33387647, year = {2021}, author = {Conner, WR and Delaney, EK and Bronski, MJ and Ginsberg, PS and Wheeler, TB and Richardson, KM and Peckenpaugh, B and Kim, KJ and Watada, M and Hoffmann, AA and Eisen, MB and Kopp, A and Cooper, BS and Turelli, M}, title = {A phylogeny for the Drosophila montium species group: A model clade for comparative analyses.}, journal = {Molecular phylogenetics and evolution}, volume = {158}, number = {}, pages = {107061}, pmid = {33387647}, issn = {1095-9513}, support = {F32 GM120893/GM/NIGMS NIH HHS/United States ; R01 GM104325/GM/NIGMS NIH HHS/United States ; R35 GM122592/GM/NIGMS NIH HHS/United States ; R35 GM124701/GM/NIGMS NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Bayes Theorem ; DNA/chemistry/isolation &amp; purification/metabolism ; Drosophila/*classification/genetics ; Drosophila Proteins/classification/genetics ; Drosophila melanogaster/classification/genetics ; Evolution, Molecular ; Phylogeny ; Sequence Analysis, DNA ; }, abstract = {The Drosophila montium species group is a clade of 94 named species, closely related to the model species D. melanogaster. The montium species group is distributed over a broad geographic range throughout Asia, Africa, and Australasia. Species of this group possess a wide range of morphologies, mating behaviors, and endosymbiont associations, making this clade useful for comparative analyses. We use genomic data from 42 available species to estimate the phylogeny and relative divergence times within the montium species group, and its relative divergence time from D. melanogaster. To assess the robustness of our phylogenetic inferences, we use 3 non-overlapping sets of 20 single-copy coding sequences and analyze all 60 genes with both Bayesian and maximum likelihood methods. Our analyses support monophyly of the group. Apart from the uncertain placement of a single species, D. baimaii, our analyses also support the monophyly of all seven subgroups proposed within the montium group. Our phylograms and relative chronograms provide a highly resolved species tree, with discordance restricted to estimates of relatively short branches deep in the tree. In contrast, age estimates for the montium crown group, relative to its divergence from D. melanogaster, depend critically on prior assumptions concerning variation in rates of molecular evolution across branches, and hence have not been reliably determined. We discuss methodological issues that limit phylogenetic resolution - even when complete genome sequences are available - as well as the utility of the current phylogeny for understanding the evolutionary and biogeographic history of this clade.}, }
@article {pmid33375268, year = {2020}, author = {Barradas, PF and Lima, C and Cardoso, L and Amorim, I and Gärtner, F and Mesquita, JR}, title = {Molecular Evidence of Hemolivia mauritanica, Ehrlichia spp. and the Endosymbiont Candidatus Midichloria Mitochondrii in Hyalomma aegyptium Infesting Testudo graeca Tortoises from Doha, Qatar.}, journal = {Animals : an open access journal from MDPI}, volume = {11}, number = {1}, pages = {}, pmid = {33375268}, issn = {2076-2615}, abstract = {Tick-borne agents constitute a growing concern for human and animal health worldwide. Hyalomma aegyptium is a hard tick with a three-host life cycle, whose main hosts for adults are Palearctic tortoises of genus Testudo. Nevertheless, immature ticks can feed on a variety of hosts, representing an important eco-epidemiological issue regarding H. aegyptium pathogens circulation. Hyalomma aegyptium ticks are vectors and/or reservoirs of various pathogenic agents, such as Ehrlichia, Anaplasma, Babesia and Hepatozoon/Hemolivia. Ehrlichia and Anaplasma are emergent tick-borne bacteria with a worldwide distribution and zoonotic potential, responsible for diseases that cause clinical manifestations that grade from acute febrile illness to a fulminant disease characterized by multi-organ system failure, depending on the species. Babesia and Hepatozoon/Hemolivia are tick-borne parasites with increasing importance in multiple species. Testudo graeca tortoises acquired in a large animal market in Doha, Qatar, were screened for a panel of tick-borne pathogens by conventional PCR followed by bidirectional sequencing. The most prevalent agent identified in ticks was Hemolivia mauritanica (28.6%), followed by Candidatus Midichloria mitochondrii (9.5%) and Ehrlichia spp. (4.7%). All samples were negative for Babesia spp. and Hepatozoon spp. Overall, 43% of the examined adult ticks were infected with at least one agent. Only 4.7% of the ticks appeared to be simultaneously infected with two agents, i.e., Ehrlichia spp. and H. mauritanica. This is the first detection of H. mauritanica, Ehrlichia spp. and Candidatus M. mitochondrii in H. aegyptium ticks collected from pet spur-thighed tortoises, in Qatar, a fact which adds to the geographical extension of these agents. The international trade of Testudo tortoises carrying ticks infected with pathogens of veterinary and medical importance deserves strict control, in order to reduce potential exotic diseases.}, }
@article {pmid33356903, year = {2021}, author = {Pérez-Rodríguez, F and González-Prieto, JM and Vera-Núñez, JA and Ruiz-Medrano, R and Peña-Cabriales, JJ and Ruiz-Herrera, J}, title = {Wide distribution of the Ustilago maydis-bacterium endosymbiosis in naturally infected maize plants.}, journal = {Plant signaling &amp; behavior}, volume = {16}, number = {2}, pages = {1855016}, pmid = {33356903}, issn = {1559-2324}, mesh = {Basidiomycota/*pathogenicity ; Host-Pathogen Interactions ; Plant Diseases/microbiology ; RNA, Ribosomal, 16S/genetics ; Symbiosis/physiology ; Zea mays/genetics/*microbiology ; }, abstract = {We have previously described that laboratory strains of Ustilago maydis, a fungal pathogen of maize and its ancestor teosinte, harbor an intracellular bacterium that enables the fungus to fix nitrogen. However, it is not clear whether other strains isolated from nature also harbor endosymbiotic bacteria, and whether these fix nitrogen for its host. In the present study, we isolated U. maydis strains from naturally infected maize. All the isolated strains harbored intracellular bacteria as determined by PCR amplification of the 16S rRNA gene, and some of them showed capacity to fix nitrogen. That these are truly bacterial endosymbionts were shown by the fact that, after thorough treatments with CuSO4 followed by serial incubations with antibiotics, the aforementioned bacterial gene was still amplified in treated fungi. In all, these data support the notion that U. maydis-bacterium endosymbiosis is a general phenomenon in this species.}, }
@article {pmid33352133, year = {2020}, author = {Sullivan, W}, title = {Vector Control: Wolbachia Expands Its Protective Reach from Humans to Plants.}, journal = {Current biology : CB}, volume = {30}, number = {24}, pages = {R1489-R1491}, doi = {10.1016/j.cub.2020.11.005}, pmid = {33352133}, issn = {1879-0445}, mesh = {Animals ; *Hemiptera ; Humans ; Insect Vectors ; *Oryza ; Plant Diseases/prevention &amp; control ; *Reoviridae ; *Wolbachia ; }, abstract = {RNA viral titers are often suppressed in insects co-infected with the bacterial endosymbiont Wolbachia. This property has been used to suppress transmission of the ragged rice stunt virus from its insect host, the brown planthopper, to the rice plant.}, }
@article {pmid33344080, year = {2020}, author = {Gil, JC and Helal, ZH and Risatti, G and Hird, SM}, title = {Ixodes scapularis microbiome correlates with life stage, not the presence of human pathogens, in ticks submitted for diagnostic testing.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e10424}, pmid = {33344080}, issn = {2167-8359}, abstract = {Ticks are globally distributed arthropods and a public health concern due to the many human pathogens they carry and transmit, including the causative agent of Lyme disease, Borrelia burgdorferi. As tick species' ranges increase, so do the number of reported tick related illnesses. The microbiome is a critical part of understanding arthropod biology, and the microbiome of pathogen vectors may provide critical insight into disease transmission and management. Yet we lack a comprehensive understanding of the microbiome of wild ticks, including what effect the presence of multiple tick-borne pathogens (TBPs) has on the microbiome. In this study we chose samples based on life stage (adult or nymph) and which TBPs were present. We used DNA from previously extracted Ixodes scapularis ticks that tested positive for zero, one, two or three common TBPs (B. burgdorferi, B. miyamotoi, Anaplasma phagocytophilum, Babesia microti). We produced 16S rRNA amplicon data for the whole tick microbiome and compared samples across TBPs status, single vs multiple coinfections, and life stages. Focusing on samples with a single TBP, we found no significant differences in microbiome diversity in ticks that were infected with B. burgdorferi and ticks with no TBPs. When comparing multiple TBPs, we found no significant difference in both alpha and beta diversity between ticks with a single TBP and ticks with multiple TBPs. Removal of TBPs from the microbiome did not alter alpha or beta diversity results. Life stage significantly correlated to variation in beta diversity and nymphs had higher alpha diversity than adult ticks. Rickettsia, a common tick endosymbiont, was the most abundant genus. This study confirms that the wild tick microbiome is highly influenced by life stage and much less by the presence of human pathogenic bacteria.}, }
@article {pmid33335517, year = {2020}, author = {Hunter, ES and Paight, C and Lane, CE}, title = {Metabolic Contributions of an Alphaproteobacterial Endosymbiont in the Apicomplexan Cardiosporidium cionae.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {580719}, pmid = {33335517}, issn = {1664-302X}, abstract = {Apicomplexa is a diverse protistan phylum composed almost exclusively of metazoan-infecting parasites, including the causative agents of malaria, cryptosporidiosis, and toxoplasmosis. A single apicomplexan genus, Nephromyces, was described in 2010 as a mutualist partner to its tunicate host. Here we present genomic and transcriptomic data from the parasitic sister species to this mutualist, Cardiosporidium cionae, and its associated bacterial endosymbiont. Cardiosporidium cionae and Nephromyces both infect tunicate hosts, localize to similar organs within these hosts, and maintain bacterial endosymbionts. Though many other protists are known to harbor bacterial endosymbionts, these associations are completely unknown in Apicomplexa outside of the Nephromycidae clade. Our data indicate that a vertically transmitted α-proteobacteria has been retained in each lineage since Nephromyces and Cardiosporidium diverged. This α-proteobacterial endosymbiont has highly reduced metabolic capabilities, but contributes the essential amino acid lysine, and essential cofactor lipoic acid to C. cionae. This partnership likely reduces resource competition with the tunicate host. However, our data indicate that the contribution of the single α-proteobacterial endosymbiont in C. cionae is minimal compared to the three taxa of endosymbionts present in the Nephromyces system, and is a potential explanation for the virulence disparity between these lineages.}, }
@article {pmid33330486, year = {2020}, author = {Zeng, M and He, Y and Du, H and Yang, J and Wan, H}, title = {Output Regulation and Function Optimization of Mitochondria in Eukaryotes.}, journal = {Frontiers in cell and developmental biology}, volume = {8}, number = {}, pages = {598112}, pmid = {33330486}, issn = {2296-634X}, abstract = {The emergence of endosymbiosis between aerobic alpha-proteobacterium and anaerobic eukaryotic cell precursors opened the chapter of eukaryotic evolution. Multiple functions of mitochondria originated from the ancient precursors of mitochondria and underwent remodeling in eukaryotic cells. Due to the dependence on mitochondrial functions, eukaryotic cells need to constantly adjust mitochondrial output based on energy demand and cellular stress. Meanwhile, eukaryotes conduct the metabolic cooperation between different cells through the involvement of mitochondria. Under some conditions, mitochondria might also be transferred to nearby cells to provide a protective mechanism. However, the endosymbiont relationship determines the existence of various types of mitochondrial injury, such as proteotoxic stress, mutational meltdown, oxidative injure, and immune activation caused by released mitochondrial contents. Eukaryotes have a repertoire of mitochondrial optimization processes, including various mitochondrial quality-control proteins, regulation of mitochondrial dynamics and activation of mitochondrial autophagy. When these quality-control processes fail, eukaryotic cells can activate apoptosis to intercept uncontrolled cell death, thereby minimizing the damage to extracellular tissue. In this review, we describe the intracellular and extracellular context-based regulation of mitochondrial output in eukaryotic cells, and introduce new findings on multifaceted quality-control processes to deal with mitochondrial defects.}, }
@article {pmid33329655, year = {2020}, author = {Yamada, N and Sakai, H and Onuma, R and Kroth, PG and Horiguchi, T}, title = {Five Non-motile Dinotom Dinoflagellates of the Genus Dinothrix.}, journal = {Frontiers in plant science}, volume = {11}, number = {}, pages = {591050}, pmid = {33329655}, issn = {1664-462X}, abstract = {Dinothrix paradoxa and Gymnodinium quadrilobatum are benthic dinoflagellates possessing diatom-derived tertiary plastids, so-called dinotoms. Due to the lack of available genetic information, their phylogenetic relationship remains unknown. In this study, sequencing of 18S ribosomal DNA (rDNA) and the rbcL gene from temporary cultures isolated from natural samples revealed that they are close relatives of another dinotom, Galeidinium rugatum. The morphologies of these three dinotoms differ significantly from each other; however, they share a distinctive life cycle, in which the non-motile cells without flagella are their dominant phase. Cell division occurs in this non-motile phase, while swimming cells only appear for several hours after being released from each daughter cell. Furthermore, we succeeded in isolating and establishing two novel dinotom strains, HG180 and HG204, which show a similar life cycle and are phylogenetically closely related to the aforementioned three species. The non-motile cells of strain HG180 are characterized by the possession of a hemispheroidal cell covered with numerous nodes, while those of the strain HG204 form aggregations consisting of spherical smooth-surface cells. Based on the similarity in life cycles and phylogenetic closeness, we conclude that all five species should belong to a single genus, Dinothrix, the oldest genus within this clade. We transferred Ga. rugatum and Gy. quadrilobatum to Dinothrix, and described strains HG180 and HG204 as Dinothrix phymatodea sp. nov. and Dinothrix pseudoparadoxa sp. nov.}, }
@article {pmid33329499, year = {2020}, author = {Oberleitner, L and Poschmann, G and Macorano, L and Schott-Verdugo, S and Gohlke, H and Stühler, K and Nowack, ECM}, title = {The Puzzle of Metabolite Exchange and Identification of Putative Octotrico Peptide Repeat Expression Regulators in the Nascent Photosynthetic Organelles of Paulinella chromatophora.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {607182}, pmid = {33329499}, issn = {1664-302X}, abstract = {The endosymbiotic acquisition of mitochondria and plastids more than one billion years ago was central for the evolution of eukaryotic life. However, owing to their ancient origin, these organelles provide only limited insights into the initial stages of organellogenesis. The cercozoan amoeba Paulinella chromatophora contains photosynthetic organelles-termed chromatophores-that evolved from a cyanobacterium ∼100 million years ago, independently from plastids in plants and algae. Despite the more recent origin of the chromatophore, it shows tight integration into the host cell. It imports hundreds of nucleus-encoded proteins, and diverse metabolites are continuously exchanged across the two chromatophore envelope membranes. However, the limited set of chromatophore-encoded solute transporters appears insufficient for supporting metabolic connectivity or protein import. Furthermore, chromatophore-localized biosynthetic pathways as well as multiprotein complexes include proteins of dual genetic origin, suggesting that mechanisms evolved that coordinate gene expression levels between chromatophore and nucleus. These findings imply that similar to the situation in mitochondria and plastids, also in P. chromatophora nuclear factors evolved that control metabolite exchange and gene expression in the chromatophore. Here we show by mass spectrometric analyses of enriched insoluble protein fractions that, unexpectedly, nucleus-encoded transporters are not inserted into the chromatophore inner envelope membrane. Thus, despite the apparent maintenance of its barrier function, canonical metabolite transporters are missing in this membrane. Instead we identified several expanded groups of short chromatophore-targeted orphan proteins. Members of one of these groups are characterized by a single transmembrane helix, and others contain amphipathic helices. We hypothesize that these proteins are involved in modulating membrane permeability. Thus, the mechanism generating metabolic connectivity of the chromatophore fundamentally differs from the one for mitochondria and plastids, but likely rather resembles the poorly understood mechanism in various bacterial endosymbionts in plants and insects. Furthermore, our mass spectrometric analysis revealed an expanded family of chromatophore-targeted helical repeat proteins. These proteins show similar domain architectures as known organelle-targeted expression regulators of the octotrico peptide repeat type in algae and plants. Apparently these chromatophore-targeted proteins evolved convergently to plastid-targeted expression regulators and are likely involved in gene expression control in the chromatophore.}, }
@article {pmid33329443, year = {2020}, author = {Venice, F and Desirò, A and Silva, G and Salvioli, A and Bonfante, P}, title = {The Mosaic Architecture of NRPS-PKS in the Arbuscular Mycorrhizal Fungus Gigaspora margarita Shows a Domain With Bacterial Signature.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {581313}, pmid = {33329443}, issn = {1664-302X}, abstract = {As obligate biotrophic symbionts, arbuscular mycorrhizal fungi (AMF) live in association with most land plants. Among them, Gigaspora margarita has been deeply investigated because of its peculiar features, i.e., the presence of an intracellular microbiota with endobacteria and viruses. The genome sequencing of this fungus revealed the presence of some hybrid non-ribosomal peptide synthases-polyketide synthases (NRPS-PKS) that have been rarely identified in AMF. The aim of this study is to describe the architecture of these NRPS-PKS sequences and to understand whether they are present in other fungal taxa related to G. margarita. A phylogenetic analysis shows that the ketoacyl synthase (KS) domain of one G. margarita NRPS-PKS clusters with prokaryotic sequences. Since horizontal gene transfer (HGT) has often been advocated as a relevant evolutionary mechanism for the spread of secondary metabolite genes, we hypothesized that a similar event could have interested the KS domain of the PKS module. The bacterial endosymbiont of G. margarita, Candidatus Glomeribacter gigasporarum (CaGg), was the first candidate as a donor, since it possesses a large biosynthetic cluster involving an NRPS-PKS. However, bioinformatics analyses do not confirm the hypothesis of a direct HGT from the endobacterium to the fungal host: indeed, endobacterial and fungal sequences show a different evolution and potentially different donors. Lastly, by amplifying a NRPS-PKS conserved fragment and mining the sequenced AMF genomes, we demonstrate that, irrespective of the presence of CaGg, G. margarita, and some other related Gigasporaceae possess such a sequence.}, }
@article {pmid33328698, year = {2020}, author = {Pröschold, T and Darienko, T}, title = {Choricystis and Lewiniosphaera gen. nov. (Trebouxiophyceae Chlorophyta), two different green algal endosymbionts in freshwater sponges.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {82}, number = {3}, pages = {175-188}, pmid = {33328698}, issn = {0334-5114}, support = {P 28333/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Associations of freshwater sponges with coccoid green algae have been known for a long time. Two types of coccoid green algae, which are commonly assigned as zoochlorellae, are recognized by morphology: small coccoids (< 3 μm) without pyrenoids and larger Chlorella-like algae (4-6 μm) with pyrenoids. Despite their wide distribution in some freshwater sponges, these green algae were never studied using a combined analysis of morphology and molecular phylogeny. We investigated several endosymbiotic strains isolated from different Spongilla species, which were available in culture collections. Phylogenetic analyses of SSU and ITS rDNA sequences revealed that the strain SAG 211-40a is a member of the Chlorellaceae and represents a new species of the newly erected genus Lewiniosphaera, L symbiontica. The phylogenetic position was confirmed by morphology and ITS-2 barcode. The endosymbionts without pyrenoid were identified as Choricystis parasitica by morphology and phylogenetic analyses. The comparison with free-living strains revealed the recognition of two new Choricystis species, C. krienitzii and C. limnetica, which were confirmed by molecular signatures in V9 region of SSU rDNA and ITS-2 barcode.}, }
@article {pmid33324385, year = {2020}, author = {Mironov, T and Sabaneyeva, E}, title = {A Robust Symbiotic Relationship Between the Ciliate Paramecium multimicronucleatum and the Bacterium Ca. Trichorickettsia Mobilis.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {603335}, pmid = {33324385}, issn = {1664-302X}, abstract = {Close reciprocal interactions in symbiotic systems have suggested the holobiont concept, in which the host and its microbiota are considered as a single entity. Ciliates are known for their ability to form symbiotic associations with prokaryotes. Relationships between the partners in such systems vary from mutualism to parasitism and differ significantly in their robustness. We assessed the viability of the ciliate Paramecium multimicronucleatum and its ability to maintain its intranuclear endosymbiont Ca. Trichorickettsia mobilis (Rickettsiaceae) after treatment with antibiotics characterized by different mode of action, such as ampicillin, streptomycin, chloramphenicol, tetracycline. The presence of endosymbionts in the host cell was determined by means of living cell observations made using differential interference contrast or fluorescence in situ hybridization with the species-specific oligonucleotide probe (FISH). Administration of antibiotics traditionally used in treatments of rickettsioses, tetracycline and chloramphenicol, depending on the concentration used and the ciliate strain treated, either caused death of both, infected and control cells, or did not affect the ability of the host to maintain the intranuclear endosymbiont. The surviving cells always manifested motile bacteria in the macronucleus. Streptomycin treatment never led to the loss of endosymbionts in any of the four infected strains, and nearly all ciliates remained viable. Ampicillin treatment never caused host cell death, but resulted in formation of filamentous and immobile oval bacterial forms. Under repeated ampicillin treatments, a part of endosymbionts was registered in the host cytoplasm, as evidenced both by FISH and transmission electron microscopy. Endosymbionts located in the host cytoplasm were enclosed in vacuoles, apparently, corresponding to autophagosomes. Nevertheless, the bacteria seemed to persist in this compartment and might cause relapse of the infection. Although the antibiotic sensitivity profile of Trichorickettsia seems to resemble that of other representatives of Rickettsiaceae, causative agents of severe diseases in humans, neither of the antibiotic treatments used in this study resulted in an aposymbiotic cell line, apparently, due to the protists' sensitivity to tetracyclines, the drugs of preference in rickettsiosis treatment. The observed robustness of this symbiotic system makes it a good model for further elaboration of the holobiont concept.}, }
@article {pmid33323078, year = {2020}, author = {Lyndby, NH and Rädecker, N and Bessette, S and Søgaard Jensen, LH and Escrig, S and Trampe, E and Kühl, M and Meibom, A}, title = {Amoebocytes facilitate efficient carbon and nitrogen assimilation in the Cassiopea-Symbiodiniaceae symbiosis.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1941}, pages = {20202393}, pmid = {33323078}, issn = {1471-2954}, mesh = {Ammonium Compounds ; Animals ; Anthozoa ; Dinoflagellida/*physiology ; Ecosystem ; Nitrogen/metabolism ; Nutrients ; Photosynthesis ; Scyphozoa/*physiology ; Symbiosis/*physiology ; }, abstract = {The upside-down jellyfish Cassiopea engages in symbiosis with photosynthetic microalgae that facilitate uptake and recycling of inorganic nutrients. By contrast to most other symbiotic cnidarians, algal endosymbionts in Cassiopea are not restricted to the gastroderm but are found in amoebocyte cells within the mesoglea. While symbiont-bearing amoebocytes are highly abundant, their role in nutrient uptake and cycling in Cassiopea remains unknown. By combining isotopic labelling experiments with correlated scanning electron microscopy, and Nano-scale secondary ion mass spectrometry (NanoSIMS) imaging, we quantified the anabolic assimilation of inorganic carbon and nitrogen at the subcellular level in juvenile Cassiopea medusae bell tissue. Amoebocytes were clustered near the sub-umbrella epidermis and facilitated efficient assimilation of inorganic nutrients. Photosynthetically fixed carbon was efficiently translocated between endosymbionts, amoebocytes and host epidermis at rates similar to or exceeding those observed in corals. The Cassiopea holobionts efficiently assimilated ammonium, while no nitrate assimilation was detected, possibly reflecting adaptation to highly dynamic environmental conditions of their natural habitat. The motile amoebocytes allow Cassiopea medusae to distribute their endosymbiont population to optimize access to light and nutrients, and transport nutrition between tissue areas. Amoebocytes thus play a vital role for the assimilation and translocation of nutrients in Cassiopea, providing an interesting new model for studies of metabolic interactions in photosymbiotic marine organisms.}, }
@article {pmid33315074, year = {2020}, author = {Cardoso, A and Gómez-Zurita, J}, title = {Food Resource Sharing of Alder Leaf Beetle Specialists (Coleoptera: Chrysomelidae) as Potential Insect-Plant Interface for Horizontal Transmission of Endosymbionts.}, journal = {Environmental entomology}, volume = {49}, number = {6}, pages = {1402-1414}, pmid = {33315074}, issn = {1938-2936}, mesh = {Animals ; *Coleoptera ; Insecta ; North America ; Phylogeny ; *RNA, Ribosomal, 16S/genetics ; Specialization ; Symbiosis ; }, abstract = {Recent studies suggest that endosymbionts of herbivore insects can be horizontally transferred to other herbivores feeding on the same host plants, whereby the plant acts as an intermediate stage in the chain of transmission. If this mechanism operates, it is also expected that insect communities sharing the same host plant will have higher chances to share their endosymbionts. In this study, we use a high-throughput 16S rRNA metabarcoding approach to investigate the presence, diversity, and potential sharing of endosymbionts in several species of leaf beetles (Coleoptera: Chrysomelidae) of a local community specialized on an alder diet in North America. Rickettsia and Wolbachia were predominant in the sample, with strong evidence for each species having their own dominant infection, of either or both types of bacteria. However, all species shared a much lower proportion of a particular Wolbachia type, compatible with the same strain dominant in one of the species of leaf beetles. Crucially, the same 16S rRNA haplotype of Wolbachia was found on alder leaf extracts. The combined evidence and the absence of this strain in a syntopic species of leaf beetle feeding on a different host plant support the hypothesis that at least the initial stages of the mechanism that would allow horizontal transmission of endosymbionts across species feeding on the same plant is possible. The accessibility and characteristics of endosymbiont associations of this system make it suitable for deeper analyses of their diversity and transmission in natural conditions.}, }
@article {pmid33313861, year = {2021}, author = {Murray, GGR and Charlesworth, J and Miller, EL and Casey, MJ and Lloyd, CT and Gottschalk, M and Tucker, AWD and Welch, JJ and Weinert, LA}, title = {Genome Reduction Is Associated with Bacterial Pathogenicity across Different Scales of Temporal and Ecological Divergence.}, journal = {Molecular biology and evolution}, volume = {38}, number = {4}, pages = {1570-1579}, pmid = {33313861}, issn = {1537-1719}, support = {BB/G019274/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; 109385/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; BB/L018934/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacteria/genetics/*pathogenicity ; *Biological Evolution ; *Genome Size ; *Genome, Bacterial ; Symbiosis ; }, abstract = {Emerging bacterial pathogens threaten global health and food security, and so it is important to ask whether these transitions to pathogenicity have any common features. We present a systematic study of the claim that pathogenicity is associated with genome reduction and gene loss. We compare broad-scale patterns across all bacteria, with detailed analyses of Streptococcus suis, an emerging zoonotic pathogen of pigs, which has undergone multiple transitions between disease and carriage forms. We find that pathogenicity is consistently associated with reduced genome size across three scales of divergence (between species within genera, and between and within genetic clusters of S. suis). Although genome reduction is also found in mutualist and commensal bacterial endosymbionts, genome reduction in pathogens cannot be solely attributed to the features of their ecology that they share with these species, that is, host restriction or intracellularity. Moreover, other typical correlates of genome reduction in endosymbionts (reduced metabolic capacity, reduced GC content, and the transient expansion of nonfunctional elements) are not consistently observed in pathogens. Together, our results indicate that genome reduction is a consistent correlate of pathogenicity in bacteria.}, }
@article {pmid33310079, year = {2021}, author = {Park, HJ and Kim, J and Choi, YJ and Kim, HC and Klein, TA and Chong, ST and Jiang, J and Richards, AL and Jang, WJ}, title = {Tick-borne rickettsiae in Midwestern region of Republic of Korea.}, journal = {Acta tropica}, volume = {215}, number = {}, pages = {105794}, doi = {10.1016/j.actatropica.2020.105794}, pmid = {33310079}, issn = {1873-6254}, mesh = {Animals ; Female ; Male ; Polymerase Chain Reaction ; Republic of Korea ; Rickettsia/genetics/*isolation &amp; purification ; Ticks/*microbiology ; }, abstract = {To identify spotted fever group (SFG) rickettsiae among ticks collected by dragging at eight sites in three provinces of the midwestern region of the Republic of Korea (ROK), genus- and species-specific quantitative real-time PCR (qPCR) assays and sequencing were performed. DNA was extracted from a total of 2,312 ticks that were assayed individually (n=140) or in pools (n=444), resulting in a total of 584 individual and pooled tick samples. The 584 tick samples were screened with the genus-specific qPCR assay (Rick17b) and produced 265 (45.38%) positive reactions [individual (n=64) and pooled (n=101) samples]. Of these genus-specific positive samples, 57 (21.51%) were identified as Candidatus Rickettsia longicornii and 48 (18.11%) were identified as R. monacensis by species-specific qPCR assays. Subsequently, nested PCR (nPCR) was performed with 120 samples, which tested positive samples for genus-specific, but not species-specific, qPCR assays. The sequences of ompA and ompB genes showed how many close relatedness to Ca. R. longicornii and Ca. R. jingxinensis isolate Xian Hl-79, uncultured Rickettsia sp. Y27-1, Ca. R. tasmanensis strain T152, R. endosymbiont of H. longicornis tick 47, and R. koreansis strain CNH17-7. In conclusion, we successfully detected specific rickettsial agents using qPCR and a sequence-based analysis approach that demonstrated the prevalence of various tick-borne Rickettsia spp. in midwestern ROK.}, }
@article {pmid33304490, year = {2020}, author = {Doellman, MM and Saint Jean, G and Egan, SP and Powell, THQ and Hood, GR and Schuler, H and Bruzzese, DJ and Glover, MM and Smith, JJ and Yee, WL and Goughnour, R and Rull, J and Aluja, M and Feder, JL}, title = {Evidence for spatial clines and mixed geographic modes of speciation for North American cherry-infesting Rhagoletis (Diptera: Tephritidae) flies.}, journal = {Ecology and evolution}, volume = {10}, number = {23}, pages = {12727-12744}, pmid = {33304490}, issn = {2045-7758}, abstract = {An important criterion for understanding speciation is the geographic context of population divergence. Three major modes of allopatric, parapatric, and sympatric speciation define the extent of spatial overlap and gene flow between diverging populations. However, mixed modes of speciation are also possible, whereby populations experience periods of allopatry, parapatry, and/or sympatry at different times as they diverge. Here, we report clinal patterns of variation for 21 nuclear-encoded microsatellites and a wing spot phenotype for cherry-infesting Rhagoletis (Diptera: Tephritidae) across North America consistent with these flies having initially diverged in parapatry followed by a period of allopatric differentiation in the early Holocene. However, mitochondrial DNA (mtDNA) displays a different pattern; cherry flies at the ends of the clines in the eastern USA and Pacific Northwest share identical haplotypes, while centrally located populations in the southwestern USA and Mexico possess a different haplotype. We hypothesize that the mitochondrial difference could be due to lineage sorting but more likely reflects a selective sweep of a favorable mtDNA variant or the spread of an endosymbiont. The estimated divergence time for mtDNA suggests possible past allopatry, secondary contact, and subsequent isolation between USA and Mexican fly populations initiated before the Wisconsin glaciation. Thus, the current genetics of cherry flies may involve different mixed modes of divergence occurring in different portions of the fly's range. We discuss the need for additional DNA sequencing and quantification of prezygotic and postzygotic reproductive isolation to verify the multiple mixed-mode hypothesis for cherry flies and draw parallels from other systems to assess the generality that speciation may commonly involve complex biogeographies of varying combinations of allopatric, parapatric, and sympatric divergence.}, }
@article {pmid33301664, year = {2020}, author = {Lubova, VA and Leonova, GN and Shutikova, AL and Bondarenko, EI}, title = {Indication Q fever pathogen in the south of Far east.}, journal = {Klinicheskaia laboratornaia diagnostika}, volume = {65}, number = {11}, pages = {724-728}, doi = {10.18821/0869-2084-2020-65-11-724-728}, pmid = {33301664}, issn = {0869-2084}, mesh = {Animals ; *Coxiella burnetii/genetics ; Far East ; Horses ; Humans ; Polymerase Chain Reaction ; *Q Fever/epidemiology ; Sheep ; Ticks/*microbiology ; }, abstract = {Q fever (coxiellosis) is a widespread natural focal disease in the world. The causative agent of coxiellosis is the gram-negative bacterium Coxiella burnetii, which is highly contagious and low virulence. The main carriers of C. burnetii are ixodid ticks, which feed on domestic and farm animals in anthropurgic foci. To address the possible circulation of the Q fever pathogen in the territory of the Primorsky Territory, 334 samples of various natural material collected in the spring-summer period of 2019 were studied. In the vicinity of the Vladivostok (on Reineke island), genetic markers of C. burnetii were detected in 19.7% of all tick species. In the Khankaisk region, coxiella DNA was detected more often (in 6.3%) in ticks of D. silvarum, in ticks of I. persulcatus and H. japonica, 1 case was detected. From 56 copies. ixodid ticks sucked to humans, C. burnetii DNA was detected in ticks of I. persulcatus in 38.8%, H. concinna - in 14.3%. In the serum of farm animals, the presence of coxiella in sheep in 3 samples was detected, in horses - in two. Sequencing of the obtained sequences showed the presence of the pathogen C. burnetii in the blood serum of animals. The ticks have stuck to people in 6 samples were identified C. burnetii and 6 samples - Coxiella-like endosymbiont. The presented results indicate the circulation of the causative agent of Q fever in the territory of the Primorsky Territory. To obtain a more complete description of the current epidemiological situation, it is necessary to conduct more extensive studies of natural material and blood of people with suspected Q fever.}, }
@article {pmid33298138, year = {2020}, author = {Ding, H and Yeo, H and Puniamoorthy, N}, title = {Wolbachia infection in wild mosquitoes (Diptera: Culicidae): implications for transmission modes and host-endosymbiont associations in Singapore.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {612}, pmid = {33298138}, issn = {1756-3305}, mesh = {Aedes/genetics/microbiology ; Anaplasmataceae Infections/*microbiology/*transmission ; Animals ; Biological Evolution ; Culex/genetics/microbiology ; Culicidae/*microbiology ; DNA, Bacterial ; Female ; Host-Pathogen Interactions/*physiology ; Male ; Mosquito Vectors/*microbiology ; Polymerase Chain Reaction ; Sequence Analysis ; Singapore ; Vector Borne Diseases ; Wolbachia/classification/genetics ; }, abstract = {BACKGROUND: Wolbachia are intracellular bacterial endosymbionts found in most insect lineages. In mosquitoes, the influence of these endosymbionts on host reproduction and arboviral transmission has spurred numerous studies aimed at using Wolbachia infection as a vector control technique. However, there are several knowledge gaps in the literature and little is known about natural Wolbachia infection across species, their transmission modes, or associations between various Wolbachia lineages and their hosts. This study aims to address these gaps by exploring mosquito-Wolbachia associations and their evolutionary implications.<br><br>METHODS: We conducted tissue-specific polymerase chain reaction screening for Wolbachia infection in the leg, gut and reproductive tissues of wild mosquitoes from Singapore using the Wolbachia surface protein gene (wsp) molecular marker. Mosquito-Wolbachia associations were explored using three methods-tanglegram, distance-based, and event-based methods-and by inferred instances of vertical transmission and host shifts.<br><br>RESULTS: Adult mosquitoes (271 specimens) representing 14 genera and 40 species were screened for Wolbachia. Overall, 21 species (51.2%) were found positive for Wolbachia, including five in the genus Aedes and five in the genus Culex. To our knowledge, Wolbachia infections have not been previously reported in seven of these 21 species: Aedes nr. fumidus, Aedes annandalei, Uranotaenia obscura, Uranotaenia trilineata, Verrallina butleri, Verrallina sp. and Zeugnomyia gracilis. Wolbachia were predominantly detected in the reproductive tissues, which is an indication of vertical transmission. However, Wolbachia infection rates varied widely within a mosquito host species. There was no clear signal of cophylogeny between the mosquito hosts and the 12 putative Wolbachia strains observed in this study. Host shift events were also observed.<br><br>CONCLUSIONS: Our results suggest that the mosquito-Wolbachia relationship is complex and that combinations of transmission modes and multiple evolutionary events likely explain the observed distribution of Wolbachia diversity across mosquito hosts. These findings have implications for a better understanding of the diversity and ecology of Wolbachia and for their utility as biocontrol agents.}, }
@article {pmid33297293, year = {2020}, author = {Sontowski, R and Gerth, M and Richter, S and Gruppe, A and Schlegel, M and van Dam, NM and Bleidorn, C}, title = {Infection Patterns and Fitness Effects of Rickettsia and Sodalis Symbionts in the Green Lacewing Chrysoperla carnea.}, journal = {Insects}, volume = {11}, number = {12}, pages = {}, pmid = {33297293}, issn = {2075-4450}, abstract = {Endosymbionts are widely distributed in insects and can strongly affect their host ecology. The common green lacewing (Chrysoperla carnea) is a neuropteran insect which is widely used in biological pest control. However, their endosymbionts and their interactions with their hosts have not been very well studied. Therefore, we screened for endosymbionts in natural and laboratory populations of Ch. carnea using diagnostic PCR amplicons. We found the endosymbiont Rickettsia to be very common in all screened natural and laboratory populations, while a hitherto uncharacterized Sodalis strain was found only in laboratory populations. By establishing lacewing lines with no, single or co-infections of Sodalis and Rickettsia, we found a high vertical transmission rate for both endosymbionts (>89%). However, we were only able to estimate these numbers for co-infected lacewings. Sodalis negatively affected the reproductive success in single and co-infected Ch. carnea, while Rickettsia showed no effect. We hypothesize that the fitness costs accrued by Sodalis infections might be more tolerable in the laboratory than in natural populations, as the latter are also prone to fluctuating environmental conditions and natural enemies. The economic and ecological importance of lacewings in biological pest control warrants a more profound understanding of its biology, which might be influenced by symbionts.}, }
@article {pmid33295865, year = {2020}, author = {Lefoulon, E and Clark, T and Guerrero, R and Cañizales, I and Cardenas-Callirgos, JM and Junker, K and Vallarino-Lhermitte, N and Makepeace, BL and Darby, AC and Foster, JM and Martin, C and Slatko, BE}, title = {Diminutive, degraded but dissimilar: Wolbachia genomes from filarial nematodes do not conform to a single paradigm.}, journal = {Microbial genomics}, volume = {6}, number = {12}, pages = {}, pmid = {33295865}, issn = {2057-5858}, mesh = {Animals ; Databases, Genetic ; Evolution, Molecular ; Filarioidea/*microbiology ; Genome Size ; Genome, Bacterial ; Genomics ; Molecular Sequence Annotation ; Phylogeny ; Sequence Analysis, DNA/*methods ; Wolbachia/*classification/genetics/isolation &amp; purification ; }, abstract = {Wolbachia are alpha-proteobacteria symbionts infecting a large range of arthropod species and two different families of nematodes. Interestingly, these endosymbionts are able to induce diverse phenotypes in their hosts: they are reproductive parasites within many arthropods, nutritional mutualists within some insects and obligate mutualists within their filarial nematode hosts. Defining Wolbachia 'species' is controversial and so they are commonly classified into 17 different phylogenetic lineages, termed supergroups, named A-F, H-Q and S. However, available genomic data remain limited and not representative of the full Wolbachia diversity; indeed, of the 24 complete genomes and 55 draft genomes of Wolbachia available to date, 84 % belong to supergroups A and B, exclusively composed of Wolbachia from arthropods. For the current study, we took advantage of a recently developed DNA-enrichment method to produce four complete genomes and two draft genomes of Wolbachia from filarial nematodes. Two complete genomes, wCtub and wDcau, are the smallest Wolbachia genomes sequenced to date (863 988 bp and 863 427 bp, respectively), as well as the first genomes representing supergroup J. These genomes confirm the validity of this supergroup, a controversial clade due to weaknesses of the multilocus sequence typing approach. We also produced the first draft Wolbachia genome from a supergroup F filarial nematode representative (wMhie), two genomes from supergroup D (wLsig and wLbra) and the complete genome of wDimm from supergroup C. Our new data confirm the paradigm of smaller Wolbachia genomes from filarial nematodes containing low levels of transposable elements and the absence of intact bacteriophage sequences, unlike many Wolbachia from arthropods, where both are more abundant. However, we observe differences among the Wolbachia genomes from filarial nematodes: no global co-evolutionary pattern, strong synteny between supergroup C and supergroup J Wolbachia, and more transposable elements observed in supergroup D Wolbachia compared to the other supergroups. Metabolic pathway analysis indicates several highly conserved pathways (haem and nucleotide biosynthesis, for example) as opposed to more variable pathways, such as vitamin B biosynthesis, which might be specific to certain host-symbiont associations. Overall, there appears to be no single Wolbachia-filarial nematode pattern of co-evolution or symbiotic relationship.}, }
@article {pmid33294364, year = {2020}, author = {Olafson, PU and Buckmeier, BG and May, MA and Thomas, DB}, title = {Molecular screening for rickettsial bacteria and piroplasms in ixodid ticks surveyed from white-tailed deer (Odocoileus virginianus) and nilgai antelope (Boselaphus tragocamelus) in southern Texas.}, journal = {International journal for parasitology. Parasites and wildlife}, volume = {13}, number = {}, pages = {252-260}, pmid = {33294364}, issn = {2213-2244}, abstract = {A survey of ixodid ticks parasitizing white-tailed deer (Odocoileus virginianus) and nilgai antelope (Boselaphus tragocamelus) was completed during the 2018-2019 public hunt season on the Laguna Atascosa National Wildlife Refuge (Cameron County, Texas) and the East Foundation's El Sauz Ranch in nearby Willacy County (Texas). Anocenter nitens was the predominant tick species identified with 5% of these ticks collected from nilgai. All life stages were encountered in high numbers on white-tailed deer, indicating that deer may be a primary host in this region. Amblyomma maculatum and Amblyomma inornatum were identified from both hosts, while Ixodes scapularis was encountered only on white-tailed deer. This is the first published record of A. inornatum on nilgai. A subset of ticks was used in PCR assays to detect Rickettsia spp., family Anaplasmataceae, Borrelia spp., and Theileria-Babesia spp. Borrelia spp. were not detected in any of the ticks analyzed. Rickettsia parkeri was detected in three A. maculatum adult ticks from deer, Rickettsia sp. endosymbiont sequences were present in all I. scapularis ticks, and Rickettsia amblyommatis was detected in three A. inornatum adult ticks from deer. Sequence analysis of Anaplasmataceae-positive amplicons from A. nitens and A. maculatum had low percent identity to published Anaplasma spp. sequences, suggesting a unique Anaplasma sp. may be circulating in the population. Anaplasma platys was detected from A. nitens larvae and an Ehrlichia sp. Delta strain was present in A. maculatum, both of unknown pathogenicity towards deer. Theileria cervi was detected in all stages of A. nitens ticks, and positive ticks originated from 27 of 31 deer and a single nilgai sampled from throughout the survey site. The primary vector for T. cervi is absent from this region, suggesting T. cervi is possibly maintained by a different tick species.}, }
@article {pmid33294020, year = {2020}, author = {Fu, Z and Meier, AR and Epstein, B and Bergland, AO and Castillo Carrillo, CI and Cooper, WR and Cruzado, RK and Horton, DR and Jensen, AS and Kelley, JL and Rashed, A and Reitz, SR and Rondon, SI and Thinakaran, J and Wenninger, EJ and Wohleb, CH and Crowder, DW and Snyder, WE}, title = {Host plants and Wolbachia shape the population genetics of sympatric herbivore populations.}, journal = {Evolutionary applications}, volume = {13}, number = {10}, pages = {2740-2753}, pmid = {33294020}, issn = {1752-4571}, abstract = {Changing climate and land-use practices have the potential to bring previously isolated populations of pest insects into new sympatry. This heightens the need to better understand how differing patterns of host-plant association, and unique endosymbionts, serve to promote genetic isolation or integration. We addressed these factors in populations of potato psyllid, Bactericera cockerelli (Šulc), a generalist herbivore that vectors a bacterial pathogen (Candidatus Liberibacter solanacearum, causal pathogen of zebra chip disease) of potato (Solanum tuberosum L.). Genome-wide SNP data revealed two major genetic clusters-psyllids collected from potato crops were genetically similar to psyllids found on a common weed, Lycium spp., but dissimilar from those found on another common non-crop host, Solanum dulcamara L. Most psyllids found on Lycium spp. and potato represented a single mitochondrial cytochrome oxidase I (COI) haplotype that has been suggested to not be native to the region, and whose arrival may have been concurrent with zebra chip disease first emerging. The putatively introduced COI haplotype usually co-occurred with endosymbiotic Wolbachia, while the putatively resident COI haplotype generally did not. Genetic intermediates between the two genetic populations of insects were rare, consistent with recent sympatry or reproductive isolation, although admixture patterns of apparent hybrids were consistent with introgression of genes from introduced into resident populations. Our results suggest that both host-plant associations and endosymbionts are shaping the population genetic structure of sympatric psyllid populations associated with different non-crop hosts. It is of future interest to explicitly examine vectorial capacity of the two populations and their potential hybrids, as population structure and hybridization might alter regional vector capacity and disease outbreaks.}, }
@article {pmid33292476, year = {2020}, author = {Banfill, CR and Wilson, ACC and Lu, HL}, title = {Further evidence that mechanisms of host/symbiont integration are dissimilar in the maternal versus embryonic Acyrthosiphon pisum bacteriome.}, journal = {EvoDevo}, volume = {11}, number = {1}, pages = {23}, pmid = {33292476}, issn = {2041-9139}, abstract = {BACKGROUND: Host/symbiont integration is a signature of evolutionarily ancient, obligate endosymbioses. However, little is known about the cellular and developmental mechanisms of host/symbiont integration at the molecular level. Many insects possess obligate bacterial endosymbionts that provide essential nutrients. To advance understanding of the developmental and metabolic integration of hosts and endosymbionts, we track the localization of a non-essential amino acid transporter, ApNEAAT1, across asexual embryogenesis in the aphid, Acyrthosiphon pisum. Previous work in adult bacteriomes revealed that ApNEAAT1 functions to exchange non-essential amino acids at the A. pisum/Buchnera aphidicola symbiotic interface. Driven by amino acid concentration gradients, ApNEAAT1 moves proline, serine, and alanine from A. pisum to Buchnera and cysteine from Buchnera to A. pisum. Here, we test the hypothesis that ApNEAAT1 is localized to the symbiotic interface during asexual embryogenesis.<br><br>RESULTS: During A. pisum asexual embryogenesis, ApNEAAT1 does not localize to the symbiotic interface. We observed ApNEAAT1 localization to the maternal follicular epithelium, the germline, and, in late-stage embryos, to anterior neural structures and insect immune cells (hemocytes). We predict that ApNEAAT1 provisions non-essential amino acids to developing oocytes and embryos, as well as to the brain and related neural structures. Additionally, ApNEAAT1 may perform roles related to host immunity.<br><br>CONCLUSIONS: Our work provides further evidence that the embryonic and adult bacteriomes of asexual A. pisum are not equivalent. Future research is needed to elucidate the developmental time point at which the bacteriome reaches maturity.}, }
@article {pmid33284808, year = {2020}, author = {Schiefer, A and Hübner, MP and Krome, A and Lämmer, C and Ehrens, A and Aden, T and Koschel, M and Neufeld, H and Chaverra-Muñoz, L and Jansen, R and Kehraus, S and König, GM and Pogorevc, D and Müller, R and Stadler, M and Hüttel, S and Hesterkamp, T and Wagner, K and Pfarr, K and Hoerauf, A}, title = {Corallopyronin A for short-course anti-wolbachial, macrofilaricidal treatment of filarial infections.}, journal = {PLoS neglected tropical diseases}, volume = {14}, number = {12}, pages = {e0008930}, pmid = {33284808}, issn = {1935-2735}, mesh = {Animals ; Female ; Filariasis/*drug therapy/parasitology ; Filaricides/*therapeutic use ; Filarioidea/*drug effects/microbiology ; Lactones/*therapeutic use ; Mice ; Mice, Inbred BALB C ; Symbiosis/drug effects ; Wolbachia/*drug effects ; }, abstract = {Current efforts to eliminate the neglected tropical diseases onchocerciasis and lymphatic filariasis, caused by the filarial nematodes Onchocerca volvulus and Wuchereria bancrofti or Brugia spp., respectively, are hampered by lack of a short-course macrofilaricidal-adult-worm killing-treatment. Anti-wolbachial antibiotics, e.g. doxycycline, target the essential Wolbachia endosymbionts of filariae and are a safe prototype adult-worm-sterilizing and macrofilaricidal regimen, in contrast to standard treatments with ivermectin or diethylcarbamazine, which mainly target the microfilariae. However, treatment regimens of 4-5 weeks necessary for doxycycline and contraindications limit its use. Therefore, we tested the preclinical anti-Wolbachia drug candidate Corallopyronin A (CorA) for in vivo efficacy during initial and chronic filarial infections in the Litomosoides sigmodontis rodent model. CorA treatment for 14 days beginning immediately after infection cleared >90% of Wolbachia endosymbionts from filariae and prevented development into adult worms. CorA treatment of patently infected microfilaremic gerbils for 14 days with 30 mg/kg twice a day (BID) achieved a sustained reduction of >99% of Wolbachia endosymbionts from adult filariae and microfilariae, followed by complete inhibition of filarial embryogenesis resulting in clearance of microfilariae. Combined treatment of CorA and albendazole, a drug currently co-administered during mass drug administrations and previously shown to enhance efficacy of anti-Wolbachia drugs, achieved microfilarial clearance after 7 days of treatment at a lower BID dose of 10 mg/kg CorA, a Human Equivalent Dose of 1.4 mg/kg. Importantly, this combination led to a significant reduction in the adult worm burden, which has not yet been published with other anti-Wolbachia candidates tested in this model. In summary, CorA is a preclinical candidate for filariasis, which significantly reduces treatment times required to achieve sustained Wolbachia depletion, clearance of microfilariae, and inhibition of embryogenesis. In combination with albendazole, CorA is robustly macrofilaricidal after 7 days of treatment and fulfills the Target Product Profile for a macrofilaricidal drug.}, }
@article {pmid33277267, year = {2020}, author = {Elston, KM and Perreau, J and Maeda, GP and Moran, NA and Barrick, JE}, title = {Engineering a Culturable Serratia symbiotica Strain for Aphid Paratransgenesis.}, journal = {Applied and environmental microbiology}, volume = {87}, number = {4}, pages = {}, pmid = {33277267}, issn = {1098-5336}, abstract = {Aphids are global agricultural pests and important models for bacterial symbiosis. To date, none of the native symbionts of aphids have been genetically manipulated, which limits our understanding of how they interact with their hosts. Serratia symbiotica CWBI-2.3[T] is a culturable, gut-associated bacterium isolated from the black bean aphid. Closely related Serratia symbiotica strains are facultative aphid endosymbionts that are vertically transmitted from mother to offspring during embryogenesis. We demonstrate that CWBI-2.3[T] can be genetically engineered using a variety of techniques, plasmids, and gene expression parts. Then, we use fluorescent protein expression to track the dynamics with which CWBI-2.3[T] colonizes the guts of multiple aphid species, and we measure how this bacterium affects aphid fitness. Finally, we show that we can induce heterologous gene expression from engineered CWBI-2.3[T] in living aphids. These results inform the development of CWBI-2.3[T] for aphid paratransgenesis, which could be used to study aphid biology and enable future agricultural technologies.IMPORTANCE Insects have remarkably diverse and integral roles in global ecosystems. Many harbor symbiotic bacteria, but very few of these bacteria have been genetically engineered. Aphids are major agricultural pests and an important model system for the study of symbiosis. This work describes methods for engineering a culturable aphid symbiont, Serratia symbiotica CWBI-2.3[T] These approaches and genetic tools could be used in the future to implement new paradigms for the biological study and control of aphids.}, }
@article {pmid33275136, year = {2021}, author = {Waneka, G and Vasquez, YM and Bennett, GM and Sloan, DB}, title = {Mutational Pressure Drives Differential Genome Conservation in Two Bacterial Endosymbionts of Sap-Feeding Insects.}, journal = {Genome biology and evolution}, volume = {13}, number = {3}, pages = {}, pmid = {33275136}, issn = {1759-6653}, support = {R01 GM118046/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/*genetics ; Betaproteobacteria/genetics ; Evolution, Molecular ; *Genome, Bacterial ; Hemiptera ; Insecta/*microbiology ; *Mutation ; Phylogeny ; Symbiosis/*genetics/*physiology ; }, abstract = {Compared with free-living bacteria, endosymbionts of sap-feeding insects have tiny and rapidly evolving genomes. Increased genetic drift, high mutation rates, and relaxed selection associated with host control of key cellular functions all likely contribute to genome decay. Phylogenetic comparisons have revealed massive variation in endosymbiont evolutionary rate, but such methods make it difficult to partition the effects of mutation versus selection. For example, the ancestor of Auchenorrhynchan insects contained two obligate endosymbionts, Sulcia and a betaproteobacterium (BetaSymb; called Nasuia in leafhoppers) that exhibit divergent rates of sequence evolution and different propensities for loss and replacement in the ensuing ∼300 Ma. Here, we use the auchenorrhynchan leafhopper Macrosteles sp. nr. severini, which retains both of the ancestral endosymbionts, to test the hypothesis that differences in evolutionary rate are driven by differential mutagenesis. We used a high-fidelity technique known as duplex sequencing to measure and compare low-frequency variants in each endosymbiont. Our direct detection of de novode novo mutations reveals that the rapidly evolving endosymbiont (Nasuia) has a much higher frequency of single-nucleotide variants than the more stable endosymbiont (Sulcia) and a mutation spectrum that is potentially even more AT-biased than implied by the 83.1% AT content of its genome. We show that indels are common in both endosymbionts but differ substantially in length and distribution around repetitive regions. Our results suggest that differences in long-term rates of sequence evolution in Sulcia versus BetaSymb, and perhaps the contrasting degrees of stability of their relationships with the host, are driven by differences in mutagenesis.}, }
@article {pmid33275132, year = {2021}, author = {Nardi, T and Olivieri, E and Kariuki, E and Sassera, D and Castelli, M}, title = {Sequence of a Coxiella Endosymbiont of the Tick Amblyomma nuttalli Suggests a Pattern of Convergent Genome Reduction in the Coxiella Genus.}, journal = {Genome biology and evolution}, volume = {13}, number = {1}, pages = {}, pmid = {33275132}, issn = {1759-6653}, mesh = {Amblyomma/classification/*genetics/microbiology ; Animals ; Bacteria ; Base Sequence ; Coxiella/*genetics/metabolism ; Female ; Genome, Bacterial ; Genomics ; Phylogeny ; Symbiosis/*genetics ; Ticks/genetics ; }, abstract = {Ticks require bacterial symbionts for the provision of necessary compounds that are absent in their hematophagous diet. Such symbionts are frequently vertically transmitted and, most commonly, belong to the Coxiella genus, which also includes the human pathogen Coxiella burnetii. This genus can be divided in four main clades, presenting partial but incomplete cocladogenesis with the tick hosts. Here, we report the genome sequence of a novel Coxiella, endosymbiont of the African tick Amblyomma nuttalli, and the ensuing comparative analyses. Its size (∼1 Mb) is intermediate between symbionts of Rhipicephalus species and other Amblyomma species. Phylogenetic analyses show that the novel sequence is the first genome of the B clade, the only one for which no genomes were previously available. Accordingly, it allows to draw an enhanced scenario of the evolution of the genus, one of parallel genome reduction of different endosymbiont lineages, which are now at different stages of reduction from a more versatile ancestor. Gene content comparison allows to infer that the ancestor could be reminiscent of C. burnetii. Interestingly, the convergent loss of mismatch repair could have been a major driver of such reductive evolution. Predicted metabolic profiles are rather homogenous among Coxiella endosymbionts, in particular vitamin biosynthesis, consistently with a host-supportive role. Concurrently, similarities among Coxiella endosymbionts according to host genus and despite phylogenetic unrelatedness hint at possible host-dependent effects.}, }
@article {pmid33263887, year = {2020}, author = {Ye, S and Siemann, E}, title = {Endosymbiont-Mediated Adaptive Responses to Stress in Holobionts.}, journal = {Results and problems in cell differentiation}, volume = {69}, number = {}, pages = {559-580}, pmid = {33263887}, issn = {0080-1844}, mesh = {Adaptation, Biological ; Animals ; Aquatic Organisms/*microbiology ; Bacteria ; Climate Change ; Ecosystem ; *Host Microbial Interactions ; Insecta/*microbiology ; Plants/*microbiology ; Stress, Physiological ; *Symbiosis ; }, abstract = {Endosymbiosis is found in all types of ecosystems and it can be sensitive to environmental changes due to the intimate interaction between the endosymbiont and the host. Indeed, global climate change disturbs the local ambient environment and threatens endosymbiotic species, and in some cases leads to local ecosystem collapse. Recent studies have revealed that the endosymbiont can affect holobiont (endosymbiont and host together) stress tolerance as much as the host does, and manipulation of the microbial partners in holobionts may mitigate the impacts of the environmental stress. Here, we first show how the endosymbiont presence affects holobiont stress tolerance by discussing three well-studied endosymbiotic systems, which include plant-fungi, aquatic organism-algae, and insect-bacteria systems. We then review how holobionts are able to alter their stress tolerance via associated endosymbionts by changing their endosymbiont composition, by adaptation of their endosymbionts, or by acclimation of their endosymbionts. Finally, we discuss how different transmission modes (vertical or horizontal transmission) might affect the adaptability of holobionts. We propose that the endosymbiont is a good target for modifying holobiont stress tolerance, which makes it critical to more fully investigate the role of endosymbionts in the adaptive responses of holobionts to stress.}, }
@article {pmid33263872, year = {2020}, author = {Dunn, CD and Somborac, T and Akpınar, BA}, title = {We're in this Together: Sensation of the Host Cell Environment by Endosymbiotic Bacteria.}, journal = {Results and problems in cell differentiation}, volume = {69}, number = {}, pages = {179-197}, pmid = {33263872}, issn = {0080-1844}, mesh = {*Bacteria/genetics ; *Biological Evolution ; Cell Communication ; Genome ; *Host Microbial Interactions ; *Symbiosis ; }, abstract = {Bacteria inhabit diverse environments, including the inside of eukaryotic cells. While a bacterial invader may initially act as a parasite or pathogen, a subsequent mutualistic relationship can emerge in which the endosymbiotic bacteria and their host share metabolites. While the environment of the host cell provides improved stability when compared to an extracellular environment, the endosymbiont population must still cope with changing conditions, including variable nutrient concentrations, the host cell cycle, host developmental programs, and host genetic variation. Furthermore, the eukaryotic host can deploy mechanisms actively preventing a bacterial return to a pathogenic state. Many endosymbionts are likely to use two-component systems (TCSs) to sense their surroundings, and expanded genomic studies of endosymbionts should reveal how TCSs may promote bacterial integration with a host cell. We suggest that studying TCS maintenance or loss may be informative about the evolutionary pathway taken toward endosymbiosis, or even toward endosymbiont-to-organelle conversion.}, }
@article {pmid33263869, year = {2020}, author = {Sabater-Muñoz, B and Toft, C}, title = {Evolution from Free-Living Bacteria to Endosymbionts of Insects: Genomic Changes and the Importance of the Chaperonin GroEL.}, journal = {Results and problems in cell differentiation}, volume = {69}, number = {}, pages = {77-103}, pmid = {33263869}, issn = {0080-1844}, mesh = {Animals ; Bacteria/*genetics ; Bacterial Proteins ; *Biological Evolution ; Chaperonin 60/*genetics ; *Genome, Bacterial ; Genomics ; Insecta/*microbiology ; Phylogeny ; *Symbiosis ; }, abstract = {Major insect lineages have independently acquired bacterial species, mainly from Gamma-proteobacteria and Bacteroidetes class, which could be nutritional mutualistic factories, facultative mutualists that protect against biotic and abiotic stresses, or reproductive manipulators (which alter the fertility of the host species in its benefit). Some of them are enclosed in bacteriocytes to assure their maternal transmission over generations. All of them show an increased level of genetic drift due to the small population size and the continuous population bottlenecking at each generation, processes that have shaped their genome, proteome, and morphology. Depending on the nature of the relationship, the degree of genome plasticity varies, i.e., obligate nutritional mutualistic symbionts have extremely small genomes lacking mobile elements, bacteriophages, or recombination machinery. Under these conditions, endosymbionts face high mutational pressures that may drive to extinction or symbiont replacement. How do then they survive for such long evolutionary time, and why do they show a genome stasis? In this chapter, after a brief introduction to the problem, we will focus on the genome changes suffered by these endosymbionts, and on the mutational robustness mechanisms, including the moonlighting chaperone GroEL that could explain their long prevalence from an evolutionary perspective by comparing them with free-living bacteria.}, }
@article {pmid33260091, year = {2021}, author = {Banović, P and Díaz-Sánchez, AA and Galon, C and Simin, V and Mijatović, D and Obregón, D and Moutailler, S and Cabezas-Cruz, A}, title = {Humans infested with Ixodes ricinus are exposed to a diverse array of tick-borne pathogens in Serbia.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {2}, pages = {101609}, doi = {10.1016/j.ttbdis.2020.101609}, pmid = {33260091}, issn = {1877-9603}, mesh = {Aged ; Animals ; Female ; Gram-Negative Bacteria/classification/*isolation &amp; purification ; Gram-Negative Bacterial Infections/*microbiology ; High-Throughput Nucleotide Sequencing ; Humans ; Ixodes/growth &amp; development/*microbiology ; Larva/growth &amp; development/microbiology ; Male ; Nymph/growth &amp; development/microbiology ; Real-Time Polymerase Chain Reaction ; Rhipicephalus sanguineus/growth &amp; development/*microbiology ; Serbia ; Tick-Borne Diseases/*microbiology ; }, abstract = {Tick-borne pathogens (TBPs) pose a major threat to human health in Europe and the whole northern hemisphere. Despite a high prevalence of TBPs in Ixodes ricinus ticks, knowledge on the incidence of tick-borne diseases in humans infested by this tick species is limited. This study was conducted in the year 2019 on patients who presented themselves to the Pasteur Institute Novi Sad with tick infestations. Ticks (n = 31) feeding on human (n = 30) and blood samples from the same individuals were collected by physicians and a microfluidic real-time high-throughput PCR system was used to test the genomic DNA of the samples for the presence of 27 bacterial and eight parasitic microorganisms in Serbia. Except for one Rhipicephalus sanguineus s.l. adult male tick, all ticks infesting humans were morphologically identified as I. ricinus. A high proportion of ticks (74 %, 23/31) were infected with at least one of the tested TB microorganisms, being Rickettsia helvetica (54 %, 17/31) the most common pathogen, but Borrelia afzelii (9 %, 3/31), Anaplasma phagocytophilum (6 %, 2/31), Borrelia miyamotoi (6 %, 2/31), and Francisella like-endosymbiont (6 %, 2/31), Borrelia valaisiana (3 %, 1/31), Borrelia lusitaniae (3 %, 1/31), Rickettsia felis (3 %, 1/31) and Rickettsia aeschlimannii (3 %, 1/31) were also identified. Despite the high infection rate of TBPs in ticks, only two human blood samples (6 %, 2/30) tested positive for the presence of TBPs, one patient (code H12, 67 years old female) was diagnosed with Borrelia spp. and the other patient was diagnosed (code H17, 71 years old female) with R. felis infection. The tick infesting patient H12 tested positive for B. afzelii, and R. helvetica and the tick infesting patient H17 tested positive for R. felis. Upon clinical examination, both patients were diagnosed with erythema migrans. No additional discomfort was reported by the patient and no additional pathology was observed by the physician. We concluded that humans bitten by I. ricinus in Serbia are exposed to a diverse array of TBPs with clinical impact in the Serbian cohort studied.}, }
@article {pmid33257562, year = {2020}, author = {Martinson, VG and Gawryluk, RMR and Gowen, BE and Curtis, CI and Jaenike, J and Perlman, SJ}, title = {Multiple origins of obligate nematode and insect symbionts by a clade of bacteria closely related to plant pathogens.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {50}, pages = {31979-31986}, pmid = {33257562}, issn = {1091-6490}, mesh = {Animals ; Drosophila/microbiology/*parasitology ; Enterobacteriaceae/isolation &amp; purification/*physiology ; Genome, Bacterial/genetics ; Genomics ; Pectobacterium/genetics ; Phylogeny ; Pseudogenes/genetics ; Rhabditida/microbiology/*physiology ; Symbiosis/*physiology ; }, abstract = {Obligate symbioses involving intracellular bacteria have transformed eukaryotic life, from providing aerobic respiration and photosynthesis to enabling colonization of previously inaccessible niches, such as feeding on xylem and phloem, and surviving in deep-sea hydrothermal vents. A major challenge in the study of obligate symbioses is to understand how they arise. Because the best studied obligate symbioses are ancient, it is especially challenging to identify early or intermediate stages. Here we report the discovery of a nascent obligate symbiosis in Howardula aoronymphium, a well-studied nematode parasite of Drosophila flies. We have found that Haoronymphium and its sister species harbor a maternally inherited intracellular bacterial symbiont. We never find the symbiont in nematode-free flies, and virtually all nematodes in the field and the laboratory are infected. Treating nematodes with antibiotics causes a severe reduction in fly infection success. The association is recent, as more distantly related insect-parasitic tylenchid nematodes do not host these endosymbionts. We also report that the Howardula nematode symbiont is a member of a widespread monophyletic group of invertebrate host-associated microbes that has independently given rise to at least four obligate symbioses, one in nematodes and three in insects, and that is sister to Pectobacterium, a lineage of plant pathogenic bacteria. Comparative genomic analysis of this group, which we name Candidatus Symbiopectobacterium, shows signatures of genome erosion characteristic of early stages of symbiosis, with the Howardula symbiont's genome containing over a thousand predicted pseudogenes, comprising a third of its genome.}, }
@article {pmid33248417, year = {2020}, author = {Madhav, M and Baker, D and Morgan, JAT and Asgari, S and James, P}, title = {Wolbachia: A tool for livestock ectoparasite control.}, journal = {Veterinary parasitology}, volume = {288}, number = {}, pages = {109297}, doi = {10.1016/j.vetpar.2020.109297}, pmid = {33248417}, issn = {1873-2550}, mesh = {Animals ; Camelus/parasitology ; Cattle/parasitology ; Cimicidae/microbiology ; Diptera/microbiology ; Ectoparasitic Infestations/parasitology/prevention &amp; control/*veterinary ; Goats/parasitology ; Horses/parasitology ; *Livestock ; Mites/microbiology ; Phthiraptera/microbiology ; Sheep, Domestic/parasitology ; Siphonaptera/microbiology ; Sus scrofa/parasitology ; Ticks/microbiology ; Wolbachia/*physiology ; }, abstract = {Ectoparasites and livestock-associated insects are a major concern throughout the world because of their economic and welfare impacts. Effective control is challenging and relies mainly on the use of chemical insecticides and acaricides. Wolbachia, an arthropod and nematode-infecting, maternally-transmitted endosymbiont is currently of widespread interest for use in novel strategies for the control of a range of arthropod-vectored human diseases and plant pests but to date has received only limited consideration for use in the control of diseases of veterinary concern. Here, we review the currently available information on Wolbachia in veterinary ectoparasites and disease vectors, consider the feasibility for use of Wolbachia in the control of livestock pests and diseases and highlight critical issues which need further investigation.}, }
@article {pmid33244313, year = {2020}, author = {Pan, H and Pierson, LS and Pierson, EA}, title = {PcsR2 Is a LuxR-Type Regulator That Is Upregulated on Wheat Roots and Is Unique to Pseudomonas chlororaphis.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {560124}, pmid = {33244313}, issn = {1664-302X}, abstract = {LuxR solos are common in plant-associated bacteria and increasingly recognized for playing important roles in plant-microbe interkingdom signaling. Unlike the LuxR-type transcriptional regulators of prototype LuxR/LuxI quorum sensing systems, luxR solos do not have a LuxI-type autoinducer synthase gene associated with them. LuxR solos in plant-pathogenic bacteria are important for virulence and in plant endosymbionts contribute to symbiosis. In the present study, we characterized an atypical LuxR solo, PcsR2, in the biological control species Pseudomonas chlororaphis 30-84 that is highly conserved among sequenced P. chlororaphis strains. Unlike most LuxR solos in the plant-associated bacteria characterized to date, pcsR2 is not associated with a proline iminopeptidase gene and the protein has an atypical N-terminal binding domain. We created a pcsR2 deletion mutant and used quantitative RT-PCR to show that the expression of pcsR2 and genes in the operon immediately downstream was upregulated ∼10-fold when the wild type strain was grown on wheat roots compared to planktonic culture. PcsR2 was involved in upregulation. Using a GFP transcriptional reporter, we found that expression of pcsR2 responded specifically to root-derived substrates as compared to leaf-derived substrates but not to endogenous AHLs. Compared to the wild type, the mutant was impaired in the ability to utilize root carbon and nitrogen sources in wheat root macerate and to colonize wheat roots. Phenazine production and most biofilm traits previously shown to be correlated with phenazine production also were diminished in the mutant. Gene expression of several of the proteins in the phenazine regulatory network including PhzR, Pip (phenazine inducing protein) and RpeA/RpeB were reduced in the mutant, and overexpression of these genes in trans restored phenazine production in the mutant to wild-type levels, indicating PcsR2 affects the activity of the these regulatory genes upstream of RpeA/RpeB via an undetermined mechanism. Our results indicate PcsR2 upregulates the expression of the adjacent operon in response to unknown wheat root-derived signals and belongs to a novel subfamily of LuxR-type transcriptional regulators found in sequenced P. chlororaphis strains.}, }
@article {pmid33240234, year = {2020}, author = {Momtaz, AZ and Ahumada Sabagh, AD and Gonzalez Amortegui, JG and Salazar, SA and Finessi, A and Hernandez, J and Christensen, S and Serbus, LR}, title = {A Role for Maternal Factors in Suppressing Cytoplasmic Incompatibility.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {576844}, pmid = {33240234}, issn = {1664-302X}, abstract = {Wolbachia are maternally transmitted bacterial endosymbionts, carried by approximately half of all insect species. Wolbachia prevalence in nature stems from manipulation of host reproduction to favor the success of infected females. The best known reproductive modification induced by Wolbachia is referred to as sperm-egg Cytoplasmic Incompatibility (CI). In CI, the sperm of Wolbachia-infected males cause embryonic lethality, attributed to paternal chromatin segregation defects during early mitotic divisions. Remarkably, the embryos of Wolbachia-infected females "rescue" CI lethality, yielding egg hatch rates equivalent to uninfected female crosses. Several models have been discussed as the basis for Rescue, and functional evidence indicates a major contribution by Wolbachia CI factors. A role for host contributions to Rescue remains largely untested. In this study, we used a chemical feeding approach to test for CI suppression capabilities by Drosophila simulans. We found that uninfected females exhibited significantly higher CI egg hatch rates in response to seven chemical treatments that affect DNA integrity, cell cycle control, and protein turnover. Three of these treatments suppressed CI induced by endogenous wRi Wolbachia, as well as an ectopic wMel Wolbachia infection. The results implicate DNA integrity as a focal aspect of CI suppression for different Wolbachia strains. The framework presented here, applied to diverse CI models, will further enrich our understanding of host reproductive manipulation by insect endosymbionts.}, }
@article {pmid33237151, year = {2020}, author = {Pimentel, AC and Beraldo, CS and Cogni, R}, title = {Host-shift as the cause of emerging infectious diseases: Experimental approaches using Drosophila-virus interactions.}, journal = {Genetics and molecular biology}, volume = {44}, number = {1 Suppl 1}, pages = {e20200197}, pmid = {33237151}, issn = {1415-4757}, abstract = {Host shifts, when a cross-species transmission of a pathogen can lead to successful infections, are the main cause of emerging infectious diseases, such as COVID-19. A complex challenge faced by the scientific community is to address the factors that determine whether the cross-species transmissions will result in spillover or sustained onwards infections. Here we review recent literature and present a perspective on current approaches we are using to understand the mechanisms underlying host shifts. We highlight the usefulness of the interactions between Drosophila species and viruses as an ideal study model. Additionally, we discuss how cross-infection experiments - when pathogens from a natural reservoir are intentionally injected in novel host species- can test the effect cross-species transmissions may have on the fitness of virus and host, and how the host phylogeny may influence this response. We also discuss experiments evaluating how cooccurrence with other viruses or the presence of the endosymbiont bacteria Wolbachia may affect the performance of new viruses in a novel host. Finally, we discuss the need of surveys of virus diversity in natural populations using next-generation sequencing technologies. In the long term, these approaches can contribute to a better understanding of the basic biology of host shifts.}, }
@article {pmid33224901, year = {2020}, author = {Govender, Y and Chan, T and Yamamoto, HS and Budnik, B and Fichorova, RN}, title = {The Role of Small Extracellular Vesicles in Viral-Protozoan Symbiosis: Lessons From Trichomonasvirus in an Isogenic Host Parasite Model.}, journal = {Frontiers in cellular and infection microbiology}, volume = {10}, number = {}, pages = {591172}, pmid = {33224901}, issn = {2235-2988}, support = {R56 AI091889/AI/NIAID NIH HHS/United States ; RC1 AI086788/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Extracellular Vesicles ; Female ; Humans ; *Parasites ; Symbiosis ; *Totiviridae ; *Trichomonas vaginalis ; }, abstract = {The protozoan parasite Trichomonas vaginalis (TV), exclusively adapted to the human genital tract, is one of the most common sexually transmitted pathogens. Adding to the complexity of the host-pathogen interactions, the parasite harbors TV-specific endosymbiont viruses (Trichomonasvirus, TVV). It was reported that small extracellular vesicles (sEVs) released by TV play a role in host immunity; however, the role of the viral endosymbiosis in this process remained unknown. We hypothesized that the virus may offer evolutionary benefit to its protozoan host at least in part by altering the immunomodulatory properties of sEVs spreading from the site of infection to non-infected immune effector cells. We infected human vaginal epithelial cells, the natural host of the parasite, with TV natively harboring TVV and an isogenic derivative of the parasite cured from the viral infection. sEVs were isolated from vaginal cell culture 24 h post TV infection and from medium where the isogenic TV strains were cultured in the absence of the human host. sEVs from TVV-negative but not TVV-positive parasites cultured alone caused NF-κB activation and increase of IL-8 and RANTES expression by uterine endocervical cells, which provide innate immune defense at the gate to the upper reproductive tract. Similarly, mononuclear leukocytes increased their IL-8, IL-6 and TNF-α output in response to sEVs from virus-negative, but not isogenic virus-positive parasites, the latter exosomes being immunosuppressive in comparison to TV medium control. The same phenomenon of suppressed immunity induced by the TVV-positive compared to TVV-negative phenotype was seen when stimulating the leukocytes with sEVs originating from infected vaginal cultures. In addition, the sEVs from the TVV-positive infection phenotype suppressed immune signaling of a toll-like receptor ligand derived from mycoplasma, another frequent TV symbiont. Quantitative comparative proteome analysis of the secreted sEVs from virus-positive versus virus-negative TV revealed differential expression of two functionally uncharacterized proteins and five proteins involved in Zn binding, protein binding, electron transfer, transferase and catalytic activities. These data support the concept that symbiosis with viruses may provide benefit to the protozoan parasite by exploiting sEVs as a vehicle for inter-cellular communications and modifying their protein cargo to suppress host immune activation.}, }
@article {pmid33222623, year = {2022}, author = {Amala, M and Richard, M and Saritha, P and Prabhu, D and Veerapandiyan, M and Surekha, K and Jeyakanthan, J}, title = {Molecular evolution, binding site interpretation and functional divergence of aspartate semialdehyde dehydrogenase.}, journal = {Journal of biomolecular structure &amp; dynamics}, volume = {40}, number = {7}, pages = {3223-3241}, doi = {10.1080/07391102.2020.1846619}, pmid = {33222623}, issn = {1538-0254}, mesh = {Amino Acid Sequence ; *Aspartate-Semialdehyde Dehydrogenase/chemistry/genetics ; Binding Sites ; *Evolution, Molecular ; Phylogeny ; }, abstract = {Aspartate Semialdehyde Dehydrogenase (ASDH) is an important enzyme essential for the viability of pathogenic microorganisms. ASDH is mainly involved in amino acid and cell wall biosynthesis of microorganisms, hence it is considered to be a promising target for drug design. This enzyme depicts similar mechanistic function in all microorganisms; although, the kinetic efficiency of an enzyme differs according to their active site residual composition. Therefore, understanding the residual variation and kinetic efficiency of the enzyme would pave new insights in structure-based drug discovery and a novel drug molecule against ASDH. Here, ASDH from Wolbachia endosymbiont of Brugia malayi is used as a prime enzyme to execute evolutionary studies. The phylogenetic analysis was opted to classify 400 sequences of ASDH enzymes based on their structure and electrostatic surfaces. Analysis resulted in 37 monophyletic clades of diverse pathogenic and non-pathogenic organisms. The representative structures of 37 ASDHs from different clades were further deciphered to structural homologues. These enzymes exhibited presence of more positively charged surfaces than negatively charged surfaces in the active site pocket which restrains evolutionary significance. Docking studies of NADP[+] with 37 enzymes reveals that site-specific residual variation in the active site pocket modulates the binding affinity (ranges of -13 to -9 kcal/mol). Type-I and Type-II divergence studies show, no significant functional divergence among ASDH, but residual changes were found among the enzyme that modulates the biochemical characteristics and catalytic efficiency. The present study not only explores residual alteration and catalytic variability, it also aids in the design of species-specific inhibitors.Communicated by Ramaswamy H. Sarma.}, }
@article {pmid33222325, year = {2021}, author = {Grottoli, AG and Toonen, RJ and van Woesik, R and Vega Thurber, R and Warner, ME and McLachlan, RH and Price, JT and Bahr, KD and Baums, IB and Castillo, KD and Coffroth, MA and Cunning, R and Dobson, KL and Donahue, MJ and Hench, JL and Iglesias-Prieto, R and Kemp, DW and Kenkel, CD and Kline, DI and Kuffner, IB and Matthews, JL and Mayfield, AB and Padilla-Gamiño, JL and Palumbi, S and Voolstra, CR and Weis, VM and Wu, HC}, title = {Increasing comparability among coral bleaching experiments.}, journal = {Ecological applications : a publication of the Ecological Society of America}, volume = {31}, number = {4}, pages = {e02262}, pmid = {33222325}, issn = {1939-5582}, mesh = {Animals ; *Anthozoa ; Coral Reefs ; *Dinoflagellida ; Temperature ; }, abstract = {Coral bleaching is the single largest global threat to coral reefs worldwide. Integrating the diverse body of work on coral bleaching is critical to understanding and combating this global problem. Yet investigating the drivers, patterns, and processes of coral bleaching poses a major challenge. A recent review of published experiments revealed a wide range of experimental variables used across studies. Such a wide range of approaches enhances discovery, but without full transparency in the experimental and analytical methods used, can also make comparisons among studies challenging. To increase comparability but not stifle innovation, we propose a common framework for coral bleaching experiments that includes consideration of coral provenance, experimental conditions, and husbandry. For example, reporting the number of genets used, collection site conditions, the experimental temperature offset(s) from the maximum monthly mean (MMM) of the collection site, experimental light conditions, flow, and the feeding regime will greatly facilitate comparability across studies. Similarly, quantifying common response variables of endosymbiont (Symbiodiniaceae) and holobiont phenotypes (i.e., color, chlorophyll, endosymbiont cell density, mortality, and skeletal growth) could further facilitate cross-study comparisons. While no single bleaching experiment can provide the data necessary to determine global coral responses of all corals to current and future ocean warming, linking studies through a common framework as outlined here, would help increase comparability among experiments, facilitate synthetic insights into the causes and underlying mechanisms of coral bleaching, and reveal unique bleaching responses among genets, species, and regions. Such a collaborative framework that fosters transparency in methods used would strengthen comparisons among studies that can help inform coral reef management and facilitate conservation strategies to mitigate coral bleaching worldwide.}, }
@article {pmid33219271, year = {2020}, author = {Serra, V and Gammuto, L and Nitla, V and Castelli, M and Lanzoni, O and Sassera, D and Bandi, C and Sandeep, BV and Verni, F and Modeo, L and Petroni, G}, title = {Morphology, ultrastructure, genomics, and phylogeny of Euplotes vanleeuwenhoeki sp. nov. and its ultra-reduced endosymbiont "Candidatus Pinguicoccus supinus" sp. nov.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {20311}, pmid = {33219271}, issn = {2045-2322}, mesh = {Computational Biology ; DNA, Bacterial/isolation &amp; purification ; Euplotes/*classification/genetics/microbiology/ultrastructure ; Genome, Bacterial ; Genome, Mitochondrial ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Phylogeny ; Symbiosis/*genetics ; *Terminology as Topic ; Verrucomicrobia/*genetics/isolation &amp; purification ; }, abstract = {Taxonomy is the science of defining and naming groups of biological organisms based on shared characteristics and, more recently, on evolutionary relationships. With the birth of novel genomics/bioinformatics techniques and the increasing interest in microbiome studies, a further advance of taxonomic discipline appears not only possible but highly desirable. The present work proposes a new approach to modern taxonomy, consisting in the inclusion of novel descriptors in the organism characterization: (1) the presence of associated microorganisms (e.g.: symbionts, microbiome), (2) the mitochondrial genome of the host, (3) the symbiont genome. This approach aims to provide a deeper comprehension of the evolutionary/ecological dimensions of organisms since their very first description. Particularly interesting, are those complexes formed by the host plus associated microorganisms, that in the present study we refer to as "holobionts". We illustrate this approach through the description of the ciliate Euplotes vanleeuwenhoeki sp. nov. and its bacterial endosymbiont "Candidatus Pinguicoccus supinus" gen. nov., sp. nov. The endosymbiont possesses an extremely reduced genome (~ 163 kbp); intriguingly, this suggests a high integration between host and symbiont.}, }
@article {pmid33216144, year = {2021}, author = {Cormier, A and Chebbi, MA and Giraud, I and Wattier, R and Teixeira, M and Gilbert, C and Rigaud, T and Cordaux, R}, title = {Comparative Genomics of Strictly Vertically Transmitted, Feminizing Microsporidia Endosymbionts of Amphipod Crustaceans.}, journal = {Genome biology and evolution}, volume = {13}, number = {1}, pages = {}, pmid = {33216144}, issn = {1759-6653}, mesh = {Amphipoda/*genetics ; Animals ; Female ; Feminization/*genetics/parasitology ; *Genomics ; Host-Parasite Interactions ; Male ; Microsporidia/*genetics ; Nosema ; Phylogeny ; Wolbachia/genetics ; }, abstract = {Microsporidia are obligate intracellular eukaryotic parasites of vertebrates and invertebrates. Microsporidia are usually pathogenic and undergo horizontal transmission or a mix of horizontal and vertical transmission. However, cases of nonpathogenic microsporidia, strictly vertically transmitted from mother to offspring, have been reported in amphipod crustaceans. Some of them further evolved the ability to feminize their nontransmitting male hosts into transmitting females. However, our understanding of the evolution of feminization in microsporidia is hindered by a lack of genomic resources. We report the sequencing and analysis of three strictly vertically transmitted microsporidia species for which feminization induction has been demonstrated (Nosema granulosis) or is strongly suspected (Dictyocoela muelleri and Dictyocoela roeselum), along with a draft genome assembly of their host Gammarus roeselii. Contrary to horizontally transmitted microsporidia that form environmental spores that can be purified, feminizing microsporidia cannot be easily isolated from their host cells. Therefore, we cosequenced symbiont and host genomic DNA and devised a computational strategy to obtain genome assemblies for the different partners. Genomic comparison with feminizing Wolbachia bacterial endosymbionts of isopod crustaceans indicated independent evolution of feminization in microsporidia and Wolbachia at the molecular genetic level. Feminization thus represents a remarkable evolutionary convergence of eukaryotic and prokaryotic microorganisms. Furthermore, a comparative genomics analysis of microsporidia allowed us to identify several candidate genes for feminization, involving functions such as DNA binding and membrane fusion. The genomic resources we generated contribute to establish Gammarus roeselii and its microsporidia symbionts as a new model to study the evolution of symbiont-mediated feminization.}, }
@article {pmid33207056, year = {2020}, author = {Lefcort, H and Tsybulnik, DY and Browning, RJ and Eagle, HP and Eggleston, TE and Magori, K and Andrade, CC}, title = {Behavioral characteristics and endosymbionts of two potential tularemia and Rocky Mountain spotted fever tick vectors.}, journal = {Journal of vector ecology : journal of the Society for Vector Ecology}, volume = {45}, number = {2}, pages = {321-332}, doi = {10.1111/jvec.12403}, pmid = {33207056}, issn = {1948-7134}, mesh = {Animals ; Arachnid Vectors/microbiology/*physiology ; *Behavior, Animal ; Dermacentor/microbiology/*physiology ; Female ; Francisella/*isolation &amp; purification ; Male ; Rickettsia/*isolation &amp; purification ; Rocky Mountain Spotted Fever/transmission ; Symbiosis ; Tularemia/transmission ; Washington ; }, abstract = {Due to climate change-induced alterations of temperature and humidity, the distribution of pathogen-carrying organisms such as ticks may shift. Tick survival is often limited by environmental factors such as dryness, but a predicted hotter and wetter world may allow the expansion of tick ranges. Dermacentor andersoni and D. variabilis ticks are morphologically similar, co-occur throughout the Inland Northwest of Washington State, U.S.A., and both can be injected with pathogenic Rickettsia and Francisella bacteria. Differences in behavior and the potential role of endosymbiotic Rickettsia and Francisella in these ticks are poorly studied. We wanted to measure behavioral and ecological differences between the two species and determine which, if any, Rickettsia and Francisella bacteria - pathogenic or endosymbiotic - they carried. Additionally, we wanted to determine if either tick species may be selected for if the climate in eastern Washington becomes wetter or dryer. We found that D. andersoni is more resistant to desiccation, but both species share similar questing behaviors such as climbing and attraction to bright light. Both also avoid the odor of eucalyptus and DEET but not permethrin. Although both tick species are capable of transmitting pathogenic species of Francisella and Rickettsia, which cause tularemia and Rocky Mountain Spotted Fever, respectively, we found primarily non-pathogenic endosymbiotic strains of Francisella and Rickettsia, and only one tick infected with F. tularensis subspecies holarctica.}, }
@article {pmid33202505, year = {2020}, author = {Lee, S and Kim, JY and Yi, MH and Lee, IY and Lee, WJ and Moon, HS and Yong, D and Yong, TS}, title = {Comparative Microbiome Analysis of Three Species of Laboratory-Reared Periplaneta Cockroaches.}, journal = {The Korean journal of parasitology}, volume = {58}, number = {5}, pages = {537-542}, pmid = {33202505}, issn = {1738-0006}, mesh = {Animals ; Ecosystem ; Environment ; High-Throughput Nucleotide Sequencing ; *Laboratories ; Male ; *Microbiota ; Periplaneta/classification/*microbiology ; Species Specificity ; }, abstract = {Cockroaches inhabit various habitats, which will influence their microbiome. Although the microbiome can be influenced by the diet and environmental factors, it can also differ between species. Therefore, we conducted 16S rDNAtargeted high-throughput sequencing to evaluate the overall bacterial composition of the microbiomes of 3 cockroach species, Periplaneta americana, P. japonica, and P. fuliginosa, raised in laboratory for several generations under the same conditions. The experiments were conducted using male adult cockroaches. The number of operational taxonomic units (OTUs) was not significantly different among the 3 species. With regard to the Shannon and Pielou indexes, higher microbiome values were noted in P. americana than in P. japonica and P. fuliginosa. Microbiome composition was also evaluated, with endosymbionts accounting for over half of all OTUs in P. japonica and P. fuliginosa. Beta diversity analysis further showed that P. japonica and P. fuliginosa had similar microbiome composition, which differed from that of P. americana. However, we also identified that P. japonica and P. fuliginosa host distinct OTUs. Thus, although microbiome compositions may vary based on multiple conditions, it is possible to identify distinct microbiome compositions among different Periplaneta cockroach species, even when the individuals are reared under the same conditions.}, }
@article {pmid33198339, year = {2020}, author = {Mubarik, MS and Khan, SH and Ahmad, A and Raza, A and Khan, Z and Sajjad, M and Sammour, RHA and Mustafa, AEMA and Al-Ghamdi, AA and Alajmi, AH and Alshamasi, FKI and Elshikh, MS}, title = {Controlling Geminiviruses before Transmission: Prospects.}, journal = {Plants (Basel, Switzerland)}, volume = {9}, number = {11}, pages = {}, pmid = {33198339}, issn = {2223-7747}, abstract = {Whitefly (Bemisia tabaci)-transmitted Geminiviruses cause serious diseases of crop plants in tropical and sub-tropical regions. Plants, animals, and their microbial symbionts have evolved complex ways to interact with each other that impact their life cycles. Blocking virus transmission by altering the biology of vector species, such as the whitefly, can be a potential approach to manage these devastating diseases. Virus transmission by insect vectors to plant hosts often involves bacterial endosymbionts. Molecular chaperonins of bacterial endosymbionts bind with virus particles and have a key role in the transmission of Geminiviruses. Hence, devising new approaches to obstruct virus transmission by manipulating bacterial endosymbionts before infection opens new avenues for viral disease control. The exploitation of bacterial endosymbiont within the insect vector would disrupt interactions among viruses, insects, and their bacterial endosymbionts. The study of this cooperating web could potentially decrease virus transmission and possibly represent an effective solution to control viral diseases in crop plants.}, }
@article {pmid33196908, year = {2021}, author = {Chao, LL and Castillo, CT and Shih, CM}, title = {Molecular detection and genetic identification of Wolbachia endosymbiont in Rhipicephalus sanguineus (Acari: Ixodidae) ticks of Taiwan.}, journal = {Experimental &amp; applied acarology}, volume = {83}, number = {1}, pages = {115-130}, pmid = {33196908}, issn = {1572-9702}, mesh = {Animals ; Female ; *Ixodidae ; Male ; Phylogeny ; *Rhipicephalus sanguineus ; Taiwan ; *Wolbachia/genetics ; }, abstract = {The genetic identity of Wolbachia endosymbiont in Rhipicephalus sanguineus ticks was determined for the first time in Taiwan. In total 1004 Rh. sanguineus ticks were examined for Wolbachia by polymerase chain reaction assay targeting the Wolbachia surface protein (wsp) gene. The prevalence of Wolbachia infection was detected in nymphs, females, and males with an infection rate of 55.8, 39.8, and 44%, respectively. The phylogenetic relationships were analyzed by comparing the sequences of wsp gene obtained from 60 strains of Wolbachia representing 11 strains of supergroup A and 10 strains of supergroup B. In general, seven major clades of supergroup A and six major clades of supergroup B can be easily distinguished by neighbour-joining analysis and were congruent by maximum likelihood method. All these Wolbachia strains of Taiwan were genetically affiliated to supergroups A and B with high sequence similarity of 98.3-100% and 98.6-100%, respectively. Intra- and inter-group analysis based on the genetic distance (GD) values indicated a lower level (GD < 0.017) within the group A strains of Taiwan compared with the group B (GD > 0.576) of other Wolbachia strains, as well as a lower level (GD < 0.062) within the group B strains of Taiwan compared with the group A (GD > 0.246) of other Wolbachia strains. Our results provide the first genetic identification of Wolbachia endosymbiont in Rh. sanguineus ticks collected from Taiwan, and detection of Wolbachia in male and nymphal ticks may imply the possible mechanism of transstadial transmission in Rh. sanguineus ticks.}, }
@article {pmid33196140, year = {2021}, author = {Brzechffa, C and Goffredi, SK}, title = {Contrasting influences on bacterial symbiont specificity by co-occurring deep-sea mussels and tubeworms.}, journal = {Environmental microbiology reports}, volume = {13}, number = {2}, pages = {104-111}, doi = {10.1111/1758-2229.12909}, pmid = {33196140}, issn = {1758-2229}, mesh = {Animals ; Bacteria/genetics ; *Bivalvia/microbiology ; Methane ; *Polychaeta/microbiology ; Symbiosis ; }, abstract = {Relationships fueled by sulfide between deep-sea invertebrates and bacterial symbionts are well known, yet the diverse overlapping factors influencing symbiont specificity are complex. For animals that obtain their symbionts from the environment, both host identity and geographic location can impact the ultimate symbiont partner. Bacterial symbionts were analysed for three co-occurring species each of Bathymodiolus mussels and vestimentiferan tubeworms, from three deep methane seeps off the west coast of Costa Rica. The bacterial internal transcribed spacer gene was analysed via direct and barcoded amplicon sequencing to reveal fine-scale symbiont diversity. Each of the three mussel species (B. earlougheri, B. billschneideri and B. nancyschneideri) hosted genetically distinct thiotrophic endosymbionts, despite living nearly side-by-side in their habitat, suggesting that host identity is crucial in driving symbiont specificity. The dominant thiotrophic symbiont of co-occurring tubeworms Escarpia spicata and Lamellibrachia (L. barhami and L. donwalshi), on the other hand, was identical regardless of host species or sample location, suggesting lack of influence by either factor on symbiont selectivity in this group of animals. These findings highlight the specific, yet distinct, influences on the environmental acquisition of symbionts in two foundational invertebrates with similar lifestyles, and provide a rapid, precise method of examining symbiont identities.}, }
@article {pmid33193996, year = {2020}, author = {Maire, J and Chouaia, B and Zaidman-Rémy, A and Heddi, A}, title = {Endosymbiosis morphological reorganization during metamorphosis diverges in weevils.}, journal = {Communicative &amp; integrative biology}, volume = {13}, number = {1}, pages = {184-188}, pmid = {33193996}, issn = {1942-0889}, abstract = {Virtually all animals associate with beneficial symbiotic bacteria. Whether and how these associations are modulated across a host's lifecycle is an important question in disentangling animal-bacteria interactions. We recently reported a case of complete morphological reorganization of symbiosis during metamorphosis of the cereal weevil, Sitophilus oryzae. In this model, the bacteriome, a specialized organ that houses the intracellular bacterium Sodalis pierantonius, undergoes a two-phase remodeling program synchronously driven by host and endosymbiont, resulting in a localization shift and the formation of multiple new bacteriomes. Here, we provide comparative data in a closely-related coleopteran, the red palm weevil Rhynchophorus ferrugineus, which is associated with the ancestral endosymbiont Nardonella. Using cell imaging experiments, we show that the red pal weevil bacteriome remains unchanged during metamorphosis, hence contrasting with what we reported in the cereal weevil S. oryzae. These findings highlight the complexity and divergence of host-symbiont interactions and their intertwining with host development, even in closely-related species. Abbreviations: DAPI: 4',6-diamidino-2-phenylindole; FISH: Fluorescence in situ hybridization; T3SS: Type III secretion system.}, }
@article {pmid33193249, year = {2020}, author = {Hirota, B and Meng, XY and Fukatsu, T}, title = {Bacteriome-Associated Endosymbiotic Bacteria of Nosodendron Tree Sap Beetles (Coleoptera: Nosodendridae).}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {588841}, pmid = {33193249}, issn = {1664-302X}, abstract = {The family Nosodendridae is a small group of tree sap beetles with only 91 described species representing three genera from the world. In 1930s, bacteria-harboring symbiotic organs, called bacteriomes, were briefly described in a European species Nosodendron fasciculare. Since then, however, no studies have been conducted on the nosodendrid endosymbiosis for decades. Here we investigated the bacteriomes and the endosymbiotic bacteria of Nosodendron coenosum and Nosodendron asiaticum using molecular phylogenetic and histological approaches. In adults and larvae, a pair of slender bacteriomes were found along both sides of the midgut. The bacteriomes consisted of large bacteriocytes at the center and flat sheath cells on the surface. Fluorescence in situ hybridization detected preferential localization of the endosymbiotic bacteria in the cytoplasm of the bacteriocytes. In reproductive adult females, the endosymbiotic bacteria were also detected at the infection zone in the ovarioles and on the surface of growing oocytes, indicating vertical symbiont transmission via ovarial passage. Transmission electron microscopy unveiled bizarre structural features of the bacteriocytes, whose cytoplasm exhibited degenerate cytology with deformed endosymbiont cells. Molecular phylogenetic analysis revealed that the nosodendrid endosymbionts formed a distinct clade in the Bacteroidetes. The nosodendrid endosymbionts were the most closely related to the bacteriome endosymbionts of bostrichid powderpost beetles and also allied to the bacteriome endosymbionts of silvanid grain beetles, uncovering an unexpected endosymbiont relationship across the unrelated beetle families Nosodendridae, Bostrichidae and Silvanidae. Host-symbiont co-evolution and presumable biological roles of the endosymbiotic bacteria are discussed.}, }
@article {pmid33193196, year = {2020}, author = {Cano, I and Ryder, D and Webb, SC and Jones, BJ and Brosnahan, CL and Carrasco, N and Bodinier, B and Furones, D and Pretto, T and Carella, F and Chollet, B and Arzul, I and Cheslett, D and Collins, E and Lohrmann, KB and Valdivia, AL and Ward, G and Carballal, MJ and Villalba, A and Marigómez, I and Mortensen, S and Christison, K and Kevin, WC and Bustos, E and Christie, L and Green, M and Feist, SW}, title = {Cosmopolitan Distribution of Endozoicomonas-Like Organisms and Other Intracellular Microcolonies of Bacteria Causing Infection in Marine Mollusks.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {577481}, pmid = {33193196}, issn = {1664-302X}, abstract = {Intracellular microcolonies of bacteria (IMC), in some cases developing large extracellular cysts (bacterial aggregates), infecting primarily gill and digestive gland, have been historically reported in a wide diversity of economically important mollusk species worldwide, sometimes associated with severe lesions and mass mortality events. As an effort to characterize those organisms, traditionally named as Rickettsia or Chlamydia-like organisms, 1950 specimens comprising 22 mollusk species were collected over 10 countries and after histology examination, a selection of 99 samples involving 20 species were subjected to 16S rRNA gene amplicon sequencing. Phylogenetic analysis showed Endozoicomonadaceae sequences in all the mollusk species analyzed. Geographical differences in the distribution of Operational Taxonomic Units (OTUs) and a particular OTU associated with pathology in king scallop (OTU_2) were observed. The presence of Endozoicomonadaceae sequences in the IMC was visually confirmed by in situ hybridization (ISH) in eight selected samples. Sequencing data also indicated other symbiotic bacteria. Subsequent phylogenetic analysis of those OTUs revealed a novel microbial diversity associated with molluskan IMC infection distributed among different taxa, including the phylum Spirochetes, the families Anaplasmataceae and Simkaniaceae, the genera Mycoplasma and Francisella, and sulfur-oxidizing endosymbionts. Sequences like Francisella halioticida/philomiragia and Candidatus Brownia rhizoecola were also obtained, however, in the absence of ISH studies, the association between those organisms and the IMCs were not confirmed. The sequences identified in this study will allow for further molecular characterization of the microbial community associated with IMC infection in marine mollusks and their correlation with severity of the lesions to clarify their role as endosymbionts, commensals or true pathogens.}, }
@article {pmid33188003, year = {2021}, author = {Oliver, JD and Price, LD and Burkhardt, NY and Heu, CC and Khoo, BS and Thorpe, CJ and Kurtti, TJ and Munderloh, UG}, title = {Growth Dynamics and Antibiotic Elimination of Symbiotic Rickettsia buchneri in the Tick Ixodes scapularis (Acari: Ixodidae).}, journal = {Applied and environmental microbiology}, volume = {87}, number = {3}, pages = {}, pmid = {33188003}, issn = {1098-5336}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI081690/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/genetics ; Ciprofloxacin/*pharmacology ; Female ; Genes, Bacterial ; Ixodes/*microbiology ; Male ; RNA, Ribosomal, 16S ; Rickettsia/*drug effects/genetics/growth &amp; development ; Symbiosis ; }, abstract = {Rickettsia buchneri is the principal symbiotic bacterium of the medically significant tick Ixodes scapularis This species has been detected primarily in the ovaries of adult female ticks and is vertically transmitted, but its tissue tropism in other life stages and function with regard to tick physiology is unknown. In order to determine the function of R. buchneri, it may be necessary to produce ticks free from this symbiont. We quantified the growth dynamics of R. buchneri naturally occurring in I. scapularis ticks throughout their life cycle and compared it with bacterial growth in ticks in which symbiont numbers were experimentally reduced or eliminated. To eliminate the bacteria, we exposed ticks to antibiotics through injection and artificial membrane feeding. Both injection and membrane feeding of the antibiotic ciprofloxacin were effective at eliminating R. buchneri from most offspring of exposed females. Because of its effectiveness and ease of use, we have determined that injection of ciprofloxacin into engorged female ticks is an efficient means of clearing R. buchneri from the majority of progeny.IMPORTANCE This paper describes the growth of symbiotic Rickettsia buchneri within Ixodes scapularis through the life cycle of the tick and provides methods to eliminate R. buchneri from I. scapularis ticks.}, }
@article {pmid33182634, year = {2020}, author = {Andreason, SA and Shelby, EA and Moss, JB and Moore, PJ and Moore, AJ and Simmons, AM}, title = {Whitefly Endosymbionts: Biology, Evolution, and Plant Virus Interactions.}, journal = {Insects}, volume = {11}, number = {11}, pages = {}, pmid = {33182634}, issn = {2075-4450}, abstract = {Whiteflies (Hemiptera: Aleyrodidae) are sap-feeding global agricultural pests. These piercing-sucking insects have coevolved with intracellular endosymbiotic bacteria that help to supplement their nutrient-poor plant sap diets with essential amino acids and carotenoids. These obligate, primary endosymbionts have been incorporated into specialized organs called bacteriomes where they sometimes coexist with facultative, secondary endosymbionts. All whitefly species harbor the primary endosymbiont Candidatus Portiera aleyrodidarum and have a variable number of secondary endosymbionts. The secondary endosymbiont complement harbored by the cryptic whitefly species Bemisia tabaci is particularly complex with various assemblages of seven different genera identified to date. In this review, we discuss whitefly associated primary and secondary endosymbionts. We focus on those associated with the notorious B. tabaci species complex with emphasis on their biological characteristics and diversity. We also discuss their interactions with phytopathogenic begomoviruses (family Geminiviridae), which are transmitted exclusively by B. tabaci in a persistent-circulative manner. Unraveling the complex interactions of these endosymbionts with their insect hosts and plant viruses could lead to advancements in whitefly and whitefly transmitted virus management.}, }
@article {pmid33177190, year = {2020}, author = {Masson, F and Lemaitre, B}, title = {Growing Ungrowable Bacteria: Overview and Perspectives on Insect Symbiont Culturability.}, journal = {Microbiology and molecular biology reviews : MMBR}, volume = {84}, number = {4}, pages = {}, pmid = {33177190}, issn = {1098-5557}, mesh = {Animals ; Bacteria/*genetics/*growth &amp; development ; *Bacterial Physiological Phenomena ; Bacteriological Techniques ; Biological Evolution ; Coculture Techniques ; Culture Media ; *Gastrointestinal Microbiome ; Host Microbial Interactions ; Insecta/*microbiology ; *Symbiosis ; }, abstract = {Insects are often involved in endosymbiosis, that is, the housing of symbiotic microbes within their tissues or within their cells. Endosymbionts are a major driving force in insects' evolution, because they dramatically affect their host physiology and allow them to adapt to new niches, for example, by complementing their diet or by protecting them against pathogens. Endosymbiotic bacteria are, however, fastidious and therefore difficult to manipulate outside of their hosts, especially intracellular species. The coevolution between hosts and endosymbionts leads to alterations in the genomes of endosymbionts, limiting their ability to cope with changing environments. Consequently, few insect endosymbionts are culturable in vitro and genetically tractable, making functional genetics studies impracticable on most endosymbiotic bacteria. However, recently, major progress has been made in manipulating several intracellular endosymbiont species in vitro, leading to astonishing discoveries on their physiology and the way they interact with their host. This review establishes a comprehensive picture of the in vitro tractability of insect endosymbiotic bacteria and addresses the reason why most species are not culturable. By compiling and discussing the latest developments in the design of custom media and genetic manipulation protocols, it aims at providing new leads to expand the range of tractable endosymbionts and foster genetic research on these models.}, }
@article {pmid33161541, year = {2021}, author = {Dumack, K and Bonkowski, M}, title = {Protists in the Plant Microbiome: An Untapped Field of Research.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {2232}, number = {}, pages = {77-84}, doi = {10.1007/978-1-0716-1040-4_8}, pmid = {33161541}, issn = {1940-6029}, mesh = {Classification/*methods ; Microbiota/*genetics ; Phylogeny ; Plant Diseases/*genetics/microbiology ; Plant Leaves/genetics/microbiology ; Plant Roots/genetics/microbiology ; Plants/genetics/*microbiology ; RNA, Ribosomal, 18S/genetics ; Rhizosphere ; Sequence Analysis, DNA ; }, abstract = {Protists are mostly unicellular eukaryotes. Some protists are beneficial for plants, while others live as endosymbionts and can cause severe plant diseases. More detailed studies on plant-protist interactions exist only for plant pathogens and parasites. A number of protists live as inconspicuous endophytes and cause no visible disease symptoms, while others appear closely associated with the rhizosphere or phyllosphere of plants, but we still have only a vague understanding on their identities and functions. Here, we provide a protocol on how to assess the plant-associated protist community via Illumina-sequencing of ribosomal marker-amplicons and describe how to assign taxonomic affiliation to the obtained sequences.}, }
@article {pmid33160070, year = {2020}, author = {Varotto-Boccazzi, I and Epis, S and Arnoldi, I and Corbett, Y and Gabrieli, P and Paroni, M and Nodari, R and Basilico, N and Sacchi, L and Gramiccia, M and Gradoni, L and Tranquillo, V and Bandi, C}, title = {Boosting immunity to treat parasitic infections: Asaia bacteria expressing a protein from Wolbachia determine M1 macrophage activation and killing of Leishmania protozoans.}, journal = {Pharmacological research}, volume = {161}, number = {}, pages = {105288}, doi = {10.1016/j.phrs.2020.105288}, pmid = {33160070}, issn = {1096-1186}, mesh = {Acetobacteraceae/genetics/*immunology/metabolism ; Animals ; Bacterial Outer Membrane Proteins/genetics/*immunology/metabolism ; Cell Line ; Cytokines/metabolism ; Genetic Vectors ; Host-Parasite Interactions ; *Immunity, Innate ; Leishmania infantum/growth &amp; development/*immunology/ultrastructure ; Leishmaniasis Vaccines/genetics/*immunology/metabolism ; *Macrophage Activation ; Macrophages/immunology/metabolism/*microbiology/*parasitology ; Mice ; Nitric Oxide/metabolism ; Phagocytosis ; Phenotype ; Reactive Oxygen Species/metabolism ; Vaccines, DNA/immunology ; }, abstract = {Leishmaniases are severe vector-borne diseases affecting humans and animals, caused by Leishmania protozoans. Over one billion people and millions of dogs live in endemic areas for leishmaniases and are at risk of infection. Immune polarization plays a major role in determining the outcome of Leishmania infections: hosts displaying M1-polarized macrophages are protected, while those biased on the M2 side acquire a chronic infection that could develop into a deadly disease. The identification of the factors involved in M1 polarization is essential for the design of therapeutic and prophylactic interventions, including vaccines. Infection by the filarial nematode Dirofilaria immitis could be one of the factors that interfere with leishmaniasis in dogs. Indeed, filarial nematodes induce a partial skew of the immune response towards M1, likely caused by their bacterial endosymbionts, Wolbachia. Here we have examined the potential of Asaia[WSP], a bacterium engineered for the expression of the Wolbachia surface protein (WSP), as an inductor of M1 macrophage activation and Leishmania killing. Macrophages stimulated with Asaia[WSP] displayed a strong leishmanicidal activity, comparable to that determined by the choice-drug amphotericin B. Additionally, Asaia[WSP] determined the expression of markers of classical macrophage activation, including M1 cytokines, ROS and NO, and an increase in phagocytosis activity. Asaia not expressing WSP also induced macrophage activation, although at a lower extent compared to Asaia[WSP]. In summary, the results of the present study confirm the immunostimulating properties of WSP highlighting a potential therapeutic efficacy against Leishmania parasites. Furthermore, Asaia was designed as a delivery system for WSP, thus developing a novel type of immunomodulating agent, worthy of being investigated for immuno-prophylaxis and -therapy of leishmaniases and other diseases that could be subverted by M1 macrophage activation.}, }
@article {pmid33148821, year = {2020}, author = {Kendra, CG and Keller, CM and Bruna, RE and Pontes, MH}, title = {Conjugal DNA Transfer in Sodalis glossinidius, a Maternally Inherited Symbiont of Tsetse Flies.}, journal = {mSphere}, volume = {5}, number = {6}, pages = {}, pmid = {33148821}, issn = {2379-5042}, support = {R21 AI148774/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Conjugation, Genetic ; Enterobacteriaceae/*genetics ; Escherichia coli/genetics ; Insect Vectors/microbiology ; Maternal Inheritance/*genetics ; *Symbiosis ; Trypanosoma brucei brucei/physiology ; Tsetse Flies/*microbiology ; }, abstract = {Stable associations between insects and bacterial species are widespread in nature. This is the case for many economically important insects, such as tsetse flies. Tsetse flies are the vectors of Trypanosoma brucei, the etiological agent of African trypanosomiasis-a zoonotic disease that incurs a high socioeconomic cost in regions of endemicity. Populations of tsetse flies are often infected with the bacterium Sodalis glossinidius Following infection, S. glossinidius establishes a chronic, stable association characterized by vertical (maternal) and horizontal (paternal) modes of transmission. Due to the stable nature of this association, S. glossinidius has been long sought as a means for the implementation of anti-Trypanosoma paratransgenesis in tsetse flies. However, the lack of tools for the genetic modification of S. glossinidius has hindered progress in this area. Here, we establish that S. glossinidius is amenable to DNA uptake by conjugation. We show that conjugation can be used as a DNA delivery method to conduct forward and reverse genetic experiments in this bacterium. This study serves as an important step in the development of genetic tools for S. glossinidius The methods highlighted here should guide the implementation of genetics for the study of the tsetse-Sodalis association and the evaluation of S. glossinidius-based tsetse fly paratransgenesis strategies.IMPORTANCE Tsetse flies are the insect vectors of T. brucei, the causative agent of African sleeping sickness-a zoonotic disease that inflicts a substantial economic cost on a broad region of sub-Saharan Africa. Notably, tsetse flies can be infected with the bacterium S. glossinidius to establish an asymptomatic chronic infection. This infection can be inherited by future generations of tsetse flies, allowing S. glossinidius to spread and persist within populations. To this effect, S. glossinidius has been considered a potential expression platform to create flies which reduce T. brucei stasis and lower overall parasite transmission to humans and animals. However, the efficient genetic manipulation of S. glossinidius has remained a technical challenge due to its complex growth requirements and uncharacterized physiology. Here, we exploit a natural mechanism of DNA transfer among bacteria and develop an efficient technique to genetically manipulate S. glossinidius for future studies in reducing trypanosome transmission.}, }
@article {pmid33148243, year = {2020}, author = {Bell, RT and Wolf, YI and Koonin, EV}, title = {Modified base-binding EVE and DCD domains: striking diversity of genomic contexts in prokaryotes and predicted involvement in a variety of cellular processes.}, journal = {BMC biology}, volume = {18}, number = {1}, pages = {159}, pmid = {33148243}, issn = {1741-7007}, mesh = {Archaeal Proteins/*metabolism ; Bacterial Proteins/*metabolism ; DNA, Archaeal/*metabolism ; *Genome, Archaeal ; *Genome, Bacterial ; RNA, Bacterial/*metabolism ; }, abstract = {BACKGROUND: DNA and RNA of all cellular life forms and many viruses contain an expansive repertoire of modified bases. The modified bases play diverse biological roles that include both regulation of transcription and translation, and protection against restriction endonucleases and antibiotics. Modified bases are often recognized by dedicated protein domains. However, the elaborate networks of interactions and processes mediated by modified bases are far from being completely understood.<br><br>RESULTS: We present a comprehensive census and classification of EVE domains that belong to the PUA/ASCH domain superfamily and bind various modified bases in DNA and RNA. We employ the "guilt by association" approach to make functional inferences from comparative analysis of bacterial and archaeal genomes, based on the distribution and associations of EVE domains in (predicted) operons and functional networks of genes. Prokaryotes encode two classes of EVE domain proteins, slow-evolving and fast-evolving ones. Slow-evolving EVE domains in &#x3b1;-proteobacteria are embedded in conserved operons, potentially involved in coupling between translation and respiration, cytochrome c biogenesis in particular, via binding 5-methylcytosine in tRNAs. In &#x3b2;- and &#x3b3;-proteobacteria, the conserved associations implicate the EVE domains in the coordination of cell division, biofilm formation, and global transcriptional regulation by non-coding 6S small RNAs, which are potentially modified and bound by the EVE domains. In eukaryotes, the EVE domain-containing THYN1-like proteins have been reported to inhibit PCD and regulate the cell cycle, potentially, via binding 5-methylcytosine and its derivatives in DNA and/or RNA. We hypothesize that the link between PCD and cytochrome c was inherited from the &#x3b1;-proteobacterial and proto-mitochondrial endosymbiont and, unexpectedly, could involve modified base recognition by EVE domains. Fast-evolving EVE domains are typically embedded in defense contexts, including toxin-antitoxin modules and type IV restriction systems, suggesting roles in the recognition of modified bases in invading DNA molecules and targeting them for restriction. We additionally identified EVE-like prokaryotic Development and Cell Death (DCD) domains that are also implicated in defense functions including PCD. This function was inherited by eukaryotes, but in animals, the DCD proteins apparently were displaced by the extended Tudor family proteins, whose partnership with Piwi-related Argonautes became the centerpiece of the Piwi-interacting RNA (piRNA) system.<br><br>CONCLUSIONS: Recognition of modified bases in DNA and RNA by EVE-like domains appears to be an important, but until now, under-appreciated, common denominator in a variety of processes including PCD, cell cycle control, antivirus immunity, stress response, and germline development in animals.}, }
@article {pmid33146464, year = {2021}, author = {Mugerwa, H and Wang, HL and Sseruwagi, P and Seal, S and Colvin, J}, title = {Whole-genome single nucleotide polymorphism and mating compatibility studies reveal the presence of distinct species in sub-Saharan Africa Bemisia tabaci whiteflies.}, journal = {Insect science}, volume = {28}, number = {6}, pages = {1553-1566}, pmid = {33146464}, issn = {1744-7917}, support = {/GATES/Bill &amp; Melinda Gates Foundation/United States ; }, mesh = {Africa South of the Sahara ; Animals ; Genome, Insect ; Genome, Mitochondrial ; *Hemiptera/classification/genetics ; Manihot ; Phylogeny ; Plant Diseases ; *Polymorphism, Single Nucleotide ; }, abstract = {In sub-Saharan Africa cassava growing areas, two members of the Bemisia tabaci species complex termed sub-Saharan Africa 1 (SSA1) and SSA2 have been reported as the prevalent whiteflies associated with the spread of viruses that cause cassava mosaic disease (CMD) and cassava brown streak disease (CBSD) pandemics. At the peak of CMD pandemic in the late 1990s, SSA2 was the prevalent whitefly, although its numbers have diminished over the last two decades with the resurgence of SSA1 whiteflies. Three SSA1 subgroups (SG1 to SG3) are the predominant whiteflies in East Africa and vary in distribution and biological properties. Mating compatibility between SSA1 subgroups and SSA2 whiteflies was reported as the possible driver for the resurgence of SSA1 whiteflies. In this study, a combination of both phylogenomic methods and reciprocal crossing experiments were applied to determine species status of SSA1 subgroups and SSA2 whitefly populations. Phylogenomic analyses conducted with 26 548 205 bp whole genome single nucleotide polymorphisms (SNPs) and the full mitogenomes clustered SSA1 subgroups together and separate from SSA2 species. Mating incompatibility between SSA1 subgroups and SSA2 further demonstrated their distinctiveness from each other. Phylogenomic analyses conducted with SNPs and mitogenomes also revealed different genetic relationships among SSA1 subgroups. The former clustered SSA1-SG1 and SSA1-SG2 together but separate from SSA1-SG3, while the latter clustered SSA1-SG2 and SSA1-SG3 together but separate from SSA1-SG1. Mating compatibility was observed between SSA1-SG1 and SSA1-SG2, while incompatibility occurred between SSA1-SG1 and SSA1-SG3, and SSA1-SG2 and SSA1-SG3. Mating results among SSA1 subgroups were coherent with phylogenomics results based on SNPs but not the full mitogenomes. Furthermore, this study revealed that the secondary endosymbiont-Wolbachia-did not mediate reproductive success in the crossing assays carried out. Overall, using genome wide SNPs together with reciprocal crossings assays, this study established accurate genetic relationships among cassava-colonizing populations, illustrating that SSA1 and SSA2 are distinct species while at least two species occur within SSA1 species.}, }
@article {pmid33138055, year = {2020}, author = {Laidoudi, Y and Levasseur, A and Medkour, H and Maaloum, M and Ben Khedher, M and Sambou, M and Bassene, H and Davoust, B and Fenollar, F and Raoult, D and Mediannikov, O}, title = {An Earliest Endosymbiont, Wolbachia massiliensis sp. nov., Strain PL13 from the Bed Bug (Cimex hemipterus), Type Strain of a New Supergroup T.}, journal = {International journal of molecular sciences}, volume = {21}, number = {21}, pages = {}, pmid = {33138055}, issn = {1422-0067}, mesh = {Animals ; Bacterial Proteins/*genetics ; Bedbugs/*microbiology ; *Genome, Bacterial ; Genomics ; Phylogeny ; Symbiosis/*genetics ; Wolbachia/*classification/genetics/isolation &amp; purification ; }, abstract = {The symbiotic Wolbachia are the most sophisticated mutualistic bacterium among all insect-associated microbiota. Wolbachia-insect relationship fluctuates from the simple facultative/parasitic to an obligate nutritional-mutualistic association as it was the case of the bedbug-Wolbachia from Cimexlectularius. Understanding this association may help in the control of associated arthropods. Genomic data have proven to be reliable tools in resolving some aspects of these symbiotic associations. Although, Wolbachia appear to be fastidious or uncultivated bacteria which strongly limited their study. Here we proposed Drosophila S2 cell line for the isolation and culture model to study Wolbachia strains. We therefore isolated and characterized a novel Wolbachia strain associated with the bedbug Cimexhemipterus, designated as wChem strain PL13, and proposed Wolbachiamassiliensis sp. nov. strain wChem-PL13 a type strain of this new species from new supergroup T. Phylogenetically, T-supergroup was close to F and S-supergroups from insects and D-supergroup from filarial nematodes. We determined the 1,291,339-bp genome of wChem-PL13, which was the smallest insect-associated Wolbachia genomes. Overall, the wChem genome shared 50% of protein coding genes with the other insect-associated facultative Wolbachia strains. These findings highlight the diversity of Wolbachia genotypes as well as the Wolbachia-host relationship among Cimicinae subfamily. The wChem provides folate and riboflavin vitamins on which the host depends, while the bacteria had a limited translation mechanism suggesting its strong dependence to its hosts. However, the clear-cut distinction between mutualism and parasitism of the wChem in C. hemipterus cannot be yet ruled out.}, }
@article {pmid33137653, year = {2021}, author = {Ryan, DG and Frezza, C and O'Neill, LA}, title = {TCA cycle signalling and the evolution of eukaryotes.}, journal = {Current opinion in biotechnology}, volume = {68}, number = {}, pages = {72-88}, pmid = {33137653}, issn = {1879-0429}, support = {109443/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; MC_UU_12022/6/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Archaea/genetics ; *Biological Evolution ; *Eukaryota/genetics ; Eukaryotic Cells ; Phylogeny ; Prokaryotic Cells ; Symbiosis ; }, abstract = {A major question remaining in the field of evolutionary biology is how prokaryotic organisms made the leap to complex eukaryotic life. The prevailing theory depicts the origin of eukaryotic cell complexity as emerging from the symbiosis between an α-proteobacterium, the ancestor of present-day mitochondria, and an archaeal host (endosymbiont theory). A primary contribution of mitochondria to eukaryogenesis has been attributed to the mitochondrial genome, which enabled the successful internalisation of bioenergetic membranes and facilitated remarkable genome expansion. It has also been postulated that a key contribution of the archaeal host during eukaryogenesis was in providing 'archaeal histones' that would enable compaction and regulation of an expanded genome. Yet, how the communication between the host and the symbiont evolved is unclear. Here, we propose an evolutionary concept in which mitochondrial TCA cycle signalling was also a crucial player during eukaryogenesis enabling the dynamic control of an expanded genome via regulation of DNA and histone modifications. Furthermore, we discuss how TCA cycle remodelling is a common evolutionary strategy invoked by eukaryotic organisms to coordinate stress responses and gene expression programmes, with a particular focus on the TCA cycle-derived metabolite itaconate.}, }
@article {pmid33128981, year = {2020}, author = {Rosado Rodríguez, G and Otero Morales, E}, title = {Assessment of heavy metal contamination at Tallaboa Bay (Puerto Rico) by marine sponges' bioaccumulation and fungal community composition.}, journal = {Marine pollution bulletin}, volume = {161}, number = {Pt B}, pages = {111803}, doi = {10.1016/j.marpolbul.2020.111803}, pmid = {33128981}, issn = {1879-3363}, mesh = {Animals ; Bays ; Bioaccumulation ; Ecosystem ; Environmental Monitoring ; *Metals, Heavy/analysis ; *Mycobiome ; *Porifera ; Puerto Rico ; *Water Pollutants, Chemical/analysis ; }, abstract = {The water filtering capacity, and the potential to accumulate contaminants such as heavy metals, make marine sponges suitable candidates for biomonitoring of marine ecosystems. Sponges also harbor a variety of endosymbionts, including fungi, which could be affected by the accumulation of contaminants. This work examined the bioaccumulation factors of heavy metals by sponges from coastal waters from Puerto Rico. Fungal communities associated with marine sponges were assessed to determine if their composition co-varied with heavy metals in sponge tissue. All sponges in our study where found to bioaccumulate arsenic, cadmium and copper. Fungi associated with the sponges showed variations in community composition among localities and sponge species. Our results suggest that sponges, specially Tedania ignis, could be used as a complementary component for biomonitoring of arsenic, cadmium and copper; and that members of the harbored fungal communities could be negatively affected by the accumulation of heavy metals in the sponges.}, }
@article {pmid33128345, year = {2021}, author = {Sanaei, E and Charlat, S and Engelstädter, J}, title = {Wolbachia host shifts: routes, mechanisms, constraints and evolutionary consequences.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {96}, number = {2}, pages = {433-453}, doi = {10.1111/brv.12663}, pmid = {33128345}, issn = {1469-185X}, mesh = {Animals ; *Arthropods ; Biological Evolution ; Mosquito Vectors ; Symbiosis ; *Wolbachia ; }, abstract = {Wolbachia is one of the most abundant endosymbionts on earth, with a wide distribution especially in arthropods. Effective maternal transmission and the induction of various phenotypes in their hosts are two key features of this bacterium. Here, we review our current understanding of another central aspect of Wolbachia's success: their ability to switch from one host species to another. We build on the proposal that Wolbachia host shifts occur in four main steps: (i) physical transfer to a new species; (ii) proliferation within that host; (iii) successful maternal transmission; and (iv) spread within the host species. Host shift can fail at each of these steps, and the likelihood of ultimate success is influenced by many factors. Some stem from traits of Wolbachia (different strains have different abilities for host switching), others on host features such as genetic resemblance (e.g. host shifting is likely to be easier between closely related species), ecological connections (the donor and recipient host need to interact), or the resident microbiota. Host shifts have enabled Wolbachia to reach its enormous current incidence and global distribution among arthropods in an epidemiological process shaped by loss and acquisition events across host species. The ability of Wolbachia to transfer between species also forms the basis of ongoing endeavours to control pests and disease vectors, following artificial introduction into uninfected hosts such as mosquitoes. Throughout, we emphasise the many knowledge gaps in our understanding of Wolbachia host shifts, and question the effectiveness of current methodology to detect these events. We conclude by discussing an apparent paradox: how can Wolbachia maintain its ability to undergo host shifts given that its biology seems dominated by vertical transmission?}, }
@article {pmid33126019, year = {2020}, author = {Li, Z and Mertens, KN and Gottschling, M and Gu, H and Söhner, S and Price, AM and Marret, F and Pospelova, V and Smith, KF and Carbonell-Moore, C and Nézan, E and Bilien, G and Shin, HH}, title = {Taxonomy and Molecular Phylogenetics of Ensiculiferaceae, fam. nov. (Peridiniales, Dinophyceae), with Consideration of their Life-history.}, journal = {Protist}, volume = {171}, number = {5}, pages = {125759}, doi = {10.1016/j.protis.2020.125759}, pmid = {33126019}, issn = {1618-0941}, mesh = {Diatoms/physiology ; Dinoflagellida/*classification/*genetics/parasitology ; *Phylogeny ; Species Specificity ; Symbiosis ; }, abstract = {In the current circumscription, the Thoracosphaeraceae comprise all dinophytes exhibiting calcified coccoid cells produced during their life-history. Species hitherto assigned to Ensiculifera and Pentapharsodinium are mostly based on the monadoid stage of life-history, while the link to the coccoid stage (occasionally treated taxonomically distinct) is not always resolved. We investigated the different life-history stages and DNA sequence data of Ensiculifera mexicana and other species occurring in samples collected from all over the world. Based on concatenated ribosomal RNA gene sequences Ensiculiferaceae represented a distinct peridinalean branch, which showed a distant relationship to other calcareous dinophytes. Both molecular and morphological data (particularly of the coccoid stage) revealed the presence of three distinct clades within Ensiculiferaceae, which may include other dinophytes exhibiting a parasitic life-history stage. At a higher taxonomic level, Ensiculiferaceae showed relationships to parasites and endosymbionts (i.e., Blastodinium and Zooxanthella) as well as to dinophytes harbouring diatoms instead of chloroplasts. These unexpected phylogenetic relationships are corroborated by the presence of five cingular plates in all such taxa, which differs from the six cingular plates of most other Thoracosphaeraceae. We herein describe Ensiculiferaceae, emend the descriptions of Ensiculifera and Pentapharsodinium, erect Matsuokaea and provide several new combinations at the species level.}, }
@article {pmid33117302, year = {2020}, author = {Sun, Y and Jiang, L and Gong, S and Guo, M and Yuan, X and Zhou, G and Lei, X and Zhang, Y and Yuan, T and Lian, J and Qian, P and Huang, H}, title = {Impact of Ocean Warming and Acidification on Symbiosis Establishment and Gene Expression Profiles in Recruits of Reef Coral Acropora intermedia.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {532447}, pmid = {33117302}, issn = {1664-302X}, abstract = {The onset of symbiosis and the early development of most broadcast spawning corals play pivotal roles in recruitment success, yet these critical early stages are threatened by multiple stressors. However, molecular mechanisms governing these critical processes under ocean warming and acidification are still poorly understood. The present study investigated the interactive impact of elevated temperature (∼28.0°C and ∼30.5°C) and partial pressure of carbon dioxide (pCO2) (∼600 and ∼1,200 μatm) on early development and the gene expression patterns in juvenile Acropora intermedia over 33 days. The results showed that coral survival was >89% and was unaffected by high temperature, pCO2, or the combined treatment. Notably, high temperature completely arrested successful symbiosis establishment and the budding process, whereas acidification had a negligible effect. Moreover, there was a positive exponential relationship between symbiosis establishment and budding rates (y = 0.0004e[6.43x], R = 0.72, P < 0.0001), which indicated the importance of symbiosis in fueling asexual budding. Compared with corals at the control temperature (28°C), those under elevated temperature preferentially harbored Durusdinium spp., despite unsuccessful symbiosis establishment. In addition, compared to the control, 351 and 153 differentially expressed genes were detected in the symbiont and coral host in response to experimental conditions, respectively. In coral host, some genes involved in nutrient transportation and tissue fluorescence were affected by high temperature. In the symbionts, a suite of genes related to cell growth, ribosomal proteins, photosynthesis, and energy production was downregulated under high temperatures, which may have severely hampered successful cell proliferation of the endosymbionts and explains the failure of symbiosis establishment. Therefore, our results suggest that the responses of symbionts to future ocean conditions could play a vital role in shaping successful symbiosis in juvenile coral.}, }
@article {pmid33114018, year = {2020}, author = {Tully, BG and Huntley, JF}, title = {Mechanisms Affecting the Acquisition, Persistence and Transmission of Francisella tularensis in Ticks.}, journal = {Microorganisms}, volume = {8}, number = {11}, pages = {}, pmid = {33114018}, issn = {2076-2607}, support = {R01 AI093351/AI/NIAID NIH HHS/United States ; }, abstract = {Over 600,000 vector-borne disease cases were reported in the United States (U.S.) in the past 13 years, of which more than three-quarters were tick-borne diseases. Although Lyme disease accounts for the majority of tick-borne disease cases in the U.S., tularemia cases have been increasing over the past decade, with >220 cases reported yearly. However, when comparing Borrelia burgdorferi (causative agent of Lyme disease) and Francisella tularensis (causative agent of tularemia), the low infectious dose (<10 bacteria), high morbidity and mortality rates, and potential transmission of tularemia by multiple tick vectors have raised national concerns about future tularemia outbreaks. Despite these concerns, little is known about how F. tularensis is acquired by, persists in, or is transmitted by ticks. Moreover, the role of one or more tick vectors in transmitting F. tularensis to humans remains a major question. Finally, virtually no studies have examined how F. tularensis adapts to life in the tick (vs. the mammalian host), how tick endosymbionts affect F. tularensis infections, or whether other factors (e.g., tick immunity) impact the ability of F. tularensis to infect ticks. This review will assess our current understanding of each of these issues and will offer a framework for future studies, which could help us better understand tularemia and other tick-borne diseases.}, }
@article {pmid33113477, year = {2021}, author = {Rollins, RE and Schaper, S and Kahlhofer, C and Frangoulidis, D and Strauß, AFT and Cardinale, M and Springer, A and Strube, C and Bakkes, DK and Becker, NS and Chitimia-Dobler, L}, title = {Ticks (Acari: Ixodidae) on birds migrating to the island of Ponza, Italy, and the tick-borne pathogens they carry.}, journal = {Ticks and tick-borne diseases}, volume = {12}, number = {1}, pages = {101590}, doi = {10.1016/j.ttbdis.2020.101590}, pmid = {33113477}, issn = {1877-9603}, mesh = {Animals ; Bacteria/isolation &amp; purification ; Bacterial Infections/epidemiology/microbiology/veterinary ; Bird Diseases/*epidemiology/microbiology/parasitology ; Incidence ; Islands ; Italy/epidemiology ; Ixodidae/growth &amp; development/*microbiology/*parasitology ; Larva/growth &amp; development/microbiology/parasitology ; Nymph/growth &amp; development/microbiology/parasitology ; Piroplasmida/isolation &amp; purification ; Prevalence ; Protozoan Infections, Animal/epidemiology/parasitology ; *Songbirds ; Tick Infestations/epidemiology/parasitology/*veterinary ; Tick-Borne Diseases/epidemiology/microbiology/parasitology/*veterinary ; }, abstract = {Seasonal migration of birds between breeding and wintering areas can facilitate the spread of tick species and tick-borne diseases. In this study, 151 birds representing 10 different bird species were captured on Ponza Island, an important migratory stopover off the western coast of Italy and screened for tick infestation. Ticks were collected and identified morphologically. Morphological identification was supported through sequencing a fragment of the 16S mitochondrial gene. In total, 16 captured birds carried ticks from four tick species: Hyalomma rufipes (n = 14), Amblyomma variegatum (n = 1), Amblyomma sp. (n = 1), and Ixodes ventalloi (n = 2). All specimens were either larvae (n = 2) or nymphs (n = 16). All ticks were investigated for tick-borne pathogens using published molecular methods. Rickettsia aeschlimannii was detected in six of the 14 collected H. rufipes ticks. Additionally, the singular A. variegatum nymph tested positive for R. africae. In all 14 H. rufipes specimens (2 larvae and 12 nymphs), Francisella-like endosymbionts were detected. Four H. rufipes ticks tested positive for Borrelia burgdorferi sensu lato in a screening PCR but did not produce sufficient amplicon amounts for species identification. All ticks tested negative for tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Coxiella-like organisms, Babesia spp., and Theileria spp. This study confirms the role of migratory birds in the spread and establishment of both exotic tick species and tick-borne pathogens outside their endemic range.}, }
@article {pmid33104188, year = {2020}, author = {Durante, IM and Butenko, A and Rašková, V and Charyyeva, A and Svobodová, M and Yurchenko, V and Hashimi, H and Lukeš, J}, title = {Large-Scale Phylogenetic Analysis of Trypanosomatid Adenylate Cyclases Reveals Associations with Extracellular Lifestyle and Host-Pathogen Interplay.}, journal = {Genome biology and evolution}, volume = {12}, number = {12}, pages = {2403-2416}, pmid = {33104188}, issn = {1759-6653}, mesh = {Adenylyl Cyclases/*genetics ; *Evolution, Molecular ; Gene Duplication ; Genome, Protozoan ; Host-Pathogen Interactions/*genetics ; *Phylogeny ; Trypanosomatina/*enzymology/genetics ; Up-Regulation ; }, abstract = {Receptor adenylate cyclases (RACs) on the surface of trypanosomatids are important players in the host-parasite interface. They detect still unidentified environmental signals that affect the parasites' responses to host immune challenge, coordination of social motility, and regulation of cell division. A lesser known class of oxygen-sensing adenylate cyclases (OACs) related to RACs has been lost in trypanosomes and expanded mostly in Leishmania species and related insect-dwelling trypanosomatids. In this work, we have undertaken a large-scale phylogenetic analysis of both classes of adenylate cyclases (ACs) in trypanosomatids and the free-living Bodo saltans. We observe that the expanded RAC repertoire in trypanosomatids with a two-host life cycle is not only associated with an extracellular lifestyle within the vertebrate host, but also with a complex path through the insect vector involving several life cycle stages. In Trypanosoma brucei, RACs are split into two major clades, which significantly differ in their expression profiles in the mammalian host and the insect vector. RACs of the closely related Trypanosoma congolense are intermingled within these two clades, supporting early RAC diversification. Subspecies of T. brucei that have lost the capacity to infect insects exhibit high numbers of pseudogenized RACs, suggesting many of these proteins have become redundant upon the acquisition of a single-host life cycle. OACs appear to be an innovation occurring after the expansion of RACs in trypanosomatids. Endosymbiont-harboring trypanosomatids exhibit a diversification of OACs, whereas these proteins are pseudogenized in Leishmania subgenus Viannia. This analysis sheds light on how ACs have evolved to allow diverse trypanosomatids to occupy multifarious niches and assume various lifestyles.}, }
@article {pmid33099649, year = {2021}, author = {Sandri, TL and Kreidenweiss, A and Cavallo, S and Weber, D and Juhas, S and Rodi, M and Woldearegai, TG and Gmeiner, M and Veletzky, L and Ramharter, M and Tazemda-Kuitsouc, GB and Matsiegui, PB and Mordmüller, B and Held, J}, title = {Molecular Epidemiology of Mansonella Species in Gabon.}, journal = {The Journal of infectious diseases}, volume = {223}, number = {2}, pages = {287-296}, doi = {10.1093/infdis/jiaa670}, pmid = {33099649}, issn = {1537-6613}, mesh = {Animals ; Carrier State/parasitology ; Cross-Sectional Studies ; Gabon/epidemiology ; Humans ; Loa/genetics ; Male ; Mansonella/*classification/*genetics ; Mansonelliasis/*epidemiology/*parasitology ; Molecular Epidemiology ; Polymerase Chain Reaction ; Rural Population ; }, abstract = {Mansonella perstans, a filarial nematode, infects large populations in Africa and Latin America. Recently, a potential new species, Mansonella sp "DEUX," was reported. Carriage of endosymbiotic Wolbachia opens treatment options for Mansonella infections. Within a cross-sectional study, we assessed the prevalence of filarial infections in 834 Gabonese individuals and the presence of the endosymbiont Wolbachia. Almost half of the participants (400/834 [48%]) were infected with filarial nematodes, with Mansonella sp "DEUX" being the most frequent (295/400 [74%]), followed by Loa loa (273/400 [68%]) and Mansonella perstans (82/400 [21%]). Being adult/elderly, male, and living in rural areas was associated with a higher risk of infection. Wolbachia carriage was confirmed in M. perstans and Mansonella sp "DEUX." In silico analysis revealed that Mansonella sp "DEUX" is not detected with currently published M. perstans-specific assays. Mansonella infections are highly prevalent in Gabon and might have been underreported, likely also beyond Gabon.}, }
@article {pmid33083143, year = {2020}, author = {Pyle, AE and Johnson, AM and Villareal, TA}, title = {Isolation, growth, and nitrogen fixation rates of the Hemiaulus-Richelia (diatom-cyanobacterium) symbiosis in culture.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e10115}, pmid = {33083143}, issn = {2167-8359}, abstract = {Nitrogen fixers (diazotrophs) are often an important nitrogen source to phytoplankton nutrient budgets in N-limited marine environments. Diazotrophic symbioses between cyanobacteria and diatoms can dominate nitrogen-fixation regionally, particularly in major river plumes and in open ocean mesoscale blooms. This study reports the successful isolation and growth in monocultures of multiple strains of a diatom-cyanobacteria symbiosis from the Gulf of Mexico using a modified artificial seawater medium. We document the influence of light and nutrients on nitrogen fixation and growth rates of the host diatom Hemiaulus hauckii Grunow together with its diazotrophic endosymbiont Richelia intracellularis Schmidt, as well as less complete results on the Hemiaulus membranaceus-R. intracellularis symbiosis. The symbioses rates reported here are for the joint diatom-cyanobacteria unit. Symbiont diazotrophy was sufficient to support both the host diatom and cyanobacteria symbionts, and the entire symbiosis replicated and grew without added nitrogen. Maximum growth rates of multiple strains of H. hauckii symbioses in N-free medium with N2 as the sole N source were 0.74-0.93 div d[-1]. Growth rates followed light saturation kinetics in H. hauckii symbioses with a growth compensation light intensity (EC) of 7-16 µmol m[-2]s[-1]and saturation light level (EK) of 84-110 µmol m[-2]s[-1]. Nitrogen fixation rates by the symbiont while within the host followed a diel pattern where rates increased from near-zero in the scotophase to a maximum 4-6 h into the photophase. At the onset of the scotophase, nitrogen-fixation rates declined over several hours to near-zero values. Nitrogen fixation also exhibited light saturation kinetics. Maximum N2 fixation rates (84 fmol N2 heterocyst[-1]h[-1]) in low light adapted cultures (50 µmol m[-2]s[-]1) were approximately 40-50% of rates (144-154 fmol N2 heterocyst[-1]h[-1]) in high light (150 and 200 µmol m[-2]s[-1]) adapted cultures. Maximum laboratory N2 fixation rates were ~6 to 8-fold higher than literature-derived field rates of the H. hauckii symbiosis. In contrast to published results on the Rhizosolenia-Richelia symbiosis, the H. hauckii symbiosis did not use nitrate when added, although ammonium was consumed by the H. hauckii symbiosis. Symbiont-free host cell cultures could not be established; however, a symbiont-free H. hauckii strain was isolated directly from the field and grown on a nitrate-based medium that would not support DDA growth. Our observations together with literature reports raise the possibility that the asymbiotic H. hauckii are lines distinct from an obligately symbiotic H. hauckii line. While brief descriptions of successful culture isolation have been published, this report provides the first detailed description of the approaches, handling, and methodologies used for successful culture of this marine symbiosis. These techniques should permit a more widespread laboratory availability of these important marine symbioses.}, }
@article {pmid33081422, year = {2020}, author = {Garcia-Vozmediano, A and Giglio, G and Ramassa, E and Nobili, F and Rossi, L and Tomassone, L}, title = {Dermacentor marginatus and Dermacentor reticulatus, and Their Infection by SFG Rickettsiae and Francisella-Like Endosymbionts, in Mountain and Periurban Habitats of Northwestern Italy.}, journal = {Veterinary sciences}, volume = {7}, number = {4}, pages = {}, pmid = {33081422}, issn = {2306-7381}, abstract = {We investigated the distribution of Dermacentor spp. and their infection by zoonotic bacteria causing SENLAT (scalp eschar neck lymphadenopathy) in Turin province, northwestern Italy. We collected ticks in a mountain and in a periurban park, from vegetation and different animal sources, and we sampled tissues from wild boar. Dermacentor marginatus (n = 121) was collected in both study areas, on vegetation, humans, and animals, while D. reticulatus (n = 13) was exclusively collected on wild boar from the periurban area. Rickettsia slovaca and Candidatus Rickettsia rioja infected 53.1% of the ticks, and R. slovaca was also identified in 11.3% of wild boar tissues. Bartonella spp. and Francisella tularensis were not detected, however, Francisella-like endosymbionts infected both tick species (9.2%). Our findings provide new insights on the current distribution of Dermacentor spp. and their infection with a spotted-fever group rickettsiae in the Alps region. Wild boar seem to play a major role in their eco-epidemiology and dispersion in the study area. Although further studies are needed to assess the burden of rickettsial diseases, our results highlight the risk of contracting SENLAT infection through Dermacentor spp. bites in the region.}, }
@article {pmid33073851, year = {2020}, author = {Can-Vargas, X and Barboza, N and Fuchs, EJ and Hernández, EJ}, title = {Spatial Distribution of Whitefly Species (Hemiptera: Aleyrodidae) and Identification of Secondary Bacterial Endosymbionts in Tomato Fields in Costa Rica.}, journal = {Journal of economic entomology}, volume = {113}, number = {6}, pages = {2900-2910}, pmid = {33073851}, issn = {1938-291X}, mesh = {Animals ; Bacteria ; Costa Rica ; *Hemiptera/genetics ; *Lycopersicon esculentum ; Symbiosis ; }, abstract = {In Costa Rica, tomato (Solanum lycopersicum Linnaeus) Linnaeus (Solanales: Solanaceae) is one of the crops most severely affected by the whiteflies (Hemiptera: Aleyrodidae) Trialeurodes vaporariorum (Westwood) and the Bemisia tabaci (Gennadius) species complex. The objective of this study was to monitor the spatial distribution and diversity of these species and to detect the presence of secondary bacterial endosymbionts in individuals collected in areas of intensive tomato production. In total, 628 whitefly individuals were identified to the species level using restriction analysis (PCR-RFLP) of a fragment of the mitochondrial cytochrome C oxidase I gene (mtCOI). Trialeurodes vaporariorum was the predominant species, followed by B. tabaci Mediterranean (MED). Bemisia tabaci New World (NW) and B. tabaci Middle East-Asia Minor 1 (MEAM1) were present in lower numbers. The mtCOI fragment was sequenced for 89 individuals and a single haplotype was found for each whitefly species. Using molecular markers, the 628 individuals were analyzed for the presence of four endosymbionts. Arsenophonus Gherna et al. (Enterobacterales: Morganellaceae) was most frequently associated with T. vaporariorum, whereas Wolbachia Hertig (Rickettsiales: Anaplasmataceae) and Rickettsia da Rocha-Lima (Rickettsiales: Rickettsiaceae) were associated with B. tabaci MED. This study confirmed that B. tabaci NW has not been completely displaced by the invasive species B. tabaci MED and B. tabaci MEAM1 present in the country. An association was found between whitefly species present in tomato and certain secondary endosymbionts, elevation was the most likely environmental factor to affect their frequency.}, }
@article {pmid33071999, year = {2020}, author = {Yang, Y and Liu, L and Singh, RP and Meng, C and Ma, S and Jing, C and Li, Y and Zhang, C}, title = {Nodule and Root Zone Microbiota of Salt-Tolerant Wild Soybean in Coastal Sand and Saline-Alkali Soil.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {2178}, pmid = {33071999}, issn = {1664-302X}, abstract = {Soil salinization limits crop growth and yield in agro-ecosystems worldwide by reducing soil health and altering the structure of microbial communities. Salt-tolerant plant growth-promoting rhizobacteria (PGPR) alleviate plant salinity stress. Wild soybean (Glycine soja Sieb. and Zucc.) is unique in agricultural ecosystems owing to its ability to grow in saline-alkali soils and fix atmospheric nitrogen via symbiotic interactions with diverse soil microbes. However, this rhizosphere microbiome and the nodule endosymbionts have not been investigated to identify PGPR. In this study, we investigated the structural and functional rhizosphere microbial communities in saline-alkali soil from the Yellow River Delta and coastal soil in China, as well as wild soybean root nodule endosymbionts. To reveal the composition of the microbial ecosystem, we performed 16S rRNA and nifH gene amplicon sequencing on root nodules and root zones under different environmental conditions. In addition, we used culture-independent methods to examine the root bacterial microbiome of wild soybean. For functional characterization of individual members of the microbiome and their impact on plant growth, we inoculated isolates from the root microbiome with wild soybean and observed nodulation. Sinorhizobium/Ensifer accounted for 97% of the root nodule microbiome, with other enriched members belonging to the phyla Actinobacteria, Bacteroidetes, Chloroflexi, Acidobacteria, and Gemmatimonadetes; the genera Sphingomonas, Microbacterium, Arthrobacter, Nocardioides, Streptomyces, Flavobacterium, Flavisolibacter, and Pseudomonas; and the family Enterobacteriaceae. Compared to saline-alkali soil from the Yellow River Delta, coastal soil was highly enriched for soybean nodules and displayed significant differences in the abundance and diversity of β-proteobacteria, δ-proteobacteria, Actinobacteria, and Bacteroidetes. Overall, the wild soybean root nodule microbiome was dominated by nutrient-providing Sinorhizobium/Ensifer and was enriched for bacterial genera that may provide salt resistance. Thus, this reductionist experimental approach provides an avenue for future systematic and functional studies of the plant root microbiome.}, }
@article {pmid33070212, year = {2021}, author = {Xu, S and Jiang, L and Qiao, G and Chen, J}, title = {Diversity of bacterial symbionts associated with Myzus persicae (Sulzer) (Hemiptera: Aphididae: Aphidinae) revealed by 16S rRNA Illumina sequencing.}, journal = {Microbial ecology}, volume = {81}, number = {3}, pages = {784-794}, pmid = {33070212}, issn = {1432-184X}, mesh = {Animals ; *Aphids ; Bacteria/genetics ; *Buchnera/genetics ; High-Throughput Nucleotide Sequencing ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Aphids are known to be associated with a variety of symbiotic bacteria. To improve our knowledge of the bacterial diversity of polyphagous aphids, in the present study, we investigated the microbiota of the cosmopolitan agricultural pest Myzus persicae (Sulzer). Ninety-two aphid samples collected from different host plants in various regions of China were examined using high-throughput amplicon sequencing. We comprehensively characterized the symbiont diversity of M. persicae and assessed the variations in aphid-associated symbiont communities. We detected a higher diversity of symbionts than has been previously observed. M. persicae hosted the primary endosymbiont Buchnera aphidicola and seven secondary symbionts, among which Wolbachia was the most prevalent and Rickettsia, Arsenophonus, and Spiroplasma were reported for the first time. Ordination analyses and statistical tests revealed that the symbiont flora associated with M. persicae did not change with respect to host plant or geography, which may be due to frequent migrations between different aphid populations. These findings will advance our knowledge of the microbiota of polyphagous insects and will enrich our understanding of assembly of host-microbiome systems.}, }
@article {pmid33060749, year = {2020}, author = {Vega de Luna, F and Córdoba-Granados, JJ and Dang, KV and Roberty, S and Cardol, P}, title = {In vivo assessment of mitochondrial respiratory alternative oxidase activity and cyclic electron flow around photosystem I on small coral fragments.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {17514}, pmid = {33060749}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/*physiology ; Chlorophyll A/*chemistry ; Electron Transport ; Energy Metabolism ; Fluorescence ; Genotype ; Light ; Mitochondria/*enzymology ; Mitochondrial Proteins/*chemistry ; Oxidation-Reduction ; Oxidoreductases/*chemistry ; Oxygen/chemistry ; Oxygen Consumption ; Photosynthesis ; Photosystem I Protein Complex ; Photosystem II Protein Complex ; Plant Proteins/*chemistry ; Spectrophotometry ; *Symbiosis ; }, abstract = {The mutualistic relationship existing between scleractinian corals and their photosynthetic endosymbionts involves a complex integration of the metabolic pathways within the holobiont. Respiration and photosynthesis are the most important of these processes and although they have been extensively studied, our understanding of their interactions and regulatory mechanisms is still limited. In this work we performed chlorophyll-a fluorescence, oxygen exchange and time-resolved absorption spectroscopy measurements on small and thin fragments (0.3 cm[2]) of the coral Stylophora pistillata. We showed that the capacity of mitochondrial alternative oxidase accounted for ca. 25% of total coral respiration, and that the high-light dependent oxygen uptake, commonly present in isolated Symbiodiniaceae, was negligible. The ratio between photosystem I (PSI) and photosystem II (PSII) active centers as well as their respective electron transport rates, indicated that PSI cyclic electron flow occurred in high light in S. pistillata and in some branching and lamellar coral species freshly collected in the field. Altogether, these results show the potential of applying advanced biophysical and spectroscopic methods on small coral fragments to understand the complex mechanisms of coral photosynthesis and respiration and their responses to environmental changes.}, }
@article {pmid33049039, year = {2020}, author = {Santos-Garcia, D and Mestre-Rincon, N and Ouvrard, D and Zchori-Fein, E and Morin, S}, title = {Portiera Gets Wild: Genome Instability Provides Insights into the Evolution of Both Whiteflies and Their Endosymbionts.}, journal = {Genome biology and evolution}, volume = {12}, number = {11}, pages = {2107-2124}, pmid = {33049039}, issn = {1759-6653}, mesh = {Acidosis ; Animals ; *Biological Evolution ; DNA Polymerase III/*genetics ; Genome, Bacterial ; *Genomic Instability ; Halomonadaceae/*genetics/metabolism ; Hemiptera/*microbiology ; Symbiosis ; }, abstract = {Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. They rely on their primary endosymbionts "Candidatus Portiera aleyrodidarum" to produce essential amino acids not present in their diet. Portiera has been codiverging with whiteflies since their origin and therefore reflects its host's evolutionary history. Like in most primary endosymbionts, the genome of Portiera stays stable across the Aleyrodidae superfamily after millions of years of codivergence. However, Portiera of the whitefly Bemisia tabaci has lost the ancestral genome order, reflecting a rare event in the endosymbiont evolution: the appearance of genome instability. To gain a better understanding of Portiera genome evolution, identify the time point in which genome instability appeared and contribute to the reconstruction of whitefly phylogeny, we developed a new phylogenetic framework. It targeted five Portiera genes and determined the presence of the DNA polymerase proofreading subunit (dnaQ) gene, previously associated with genome instability, and two alternative gene rearrangements. Our results indicated that Portiera gene sequences provide a robust tool for studying intergenera phylogenetic relationships in whiteflies. Using these new framework, we found that whitefly species from the Singhiella, Aleurolobus, and Bemisia genera form a monophyletic tribe, the Aleurolobini, and that their Portiera exhibit genome instability. This instability likely arose once in the common ancestor of the Aleurolobini tribe (at least 70 Ma), drawing a link between the appearance of genome instability in Portiera and the switch from multibacteriocyte to a single-bacteriocyte mode of inheritance in this tribe.}, }
@article {pmid33041180, year = {2021}, author = {Rosset, SL and Oakley, CA and Ferrier-Pagès, C and Suggett, DJ and Weis, VM and Davy, SK}, title = {The Molecular Language of the Cnidarian-Dinoflagellate Symbiosis.}, journal = {Trends in microbiology}, volume = {29}, number = {4}, pages = {320-333}, doi = {10.1016/j.tim.2020.08.005}, pmid = {33041180}, issn = {1878-4380}, mesh = {Animals ; Coral Reefs ; Dinoflagellida/*genetics/*physiology ; Lipid Metabolism ; Lipids ; Signal Transduction/*genetics/physiology ; Symbiosis/*genetics/physiology ; }, abstract = {The cnidarian-dinoflagellate symbiosis is of huge importance as it underpins the success of coral reefs, yet we know very little about how the host cnidarian and its dinoflagellate endosymbionts communicate with each other to form a functionally integrated unit. Here, we review the current knowledge of interpartner molecular signaling in this symbiosis, with an emphasis on lipids, glycans, reactive species, biogenic volatiles, and noncoding RNA. We draw upon evidence of these compounds from recent omics-based studies of cnidarian-dinoflagellate symbiosis and discuss the signaling roles that they play in other, better-studied symbioses. We then consider how improved knowledge of interpartner signaling might be used to develop solutions to the coral reef crisis by, for example, engineering more thermally resistant corals.}, }
@article {pmid33038482, year = {2021}, author = {Khoo, JJ and Husin, NA and Lim, FS and Oslan, SNH and Mohd Azami, SNI and To, SW and Abd Majid, MA and Lee, HY and Loong, SK and Khor, CS and AbuBakar, S}, title = {Molecular detection of pathogens from ectoparasites recovered from peri-domestic animals, and the first description of a Candidatus Midichloria sp. from Haemaphysalis wellingtoni from rural communities in Malaysia.}, journal = {Parasitology international}, volume = {80}, number = {}, pages = {102202}, doi = {10.1016/j.parint.2020.102202}, pmid = {33038482}, issn = {1873-0329}, mesh = {Anaplasma/isolation &amp; purification ; Animals ; Borrelia/isolation &amp; purification ; Cats/microbiology/parasitology ; Chickens/microbiology/parasitology ; Coxiella burnetii/isolation &amp; purification ; Ctenocephalides/*microbiology/*parasitology ; Dogs/microbiology/parasitology ; Ixodidae/*microbiology/*parasitology ; Malaysia ; Polymerase Chain Reaction/veterinary ; Rickettsiales/genetics/*isolation &amp; purification ; Rural Population ; Sequence Analysis, DNA/veterinary ; }, abstract = {Rural communities in Malaysia have been shown to be exposed to Coxiella, Borrelia and rickettsial infections in previous seroprevalence studies. Further research is necessary to identify the actual causative agents and the potential vectors of these infections. The arthropods parasitizing peri-domestic animals in these communities may serve as the vector in transmitting arthropod-borne and zoonotic agents to the humans. Molecular screening of bacterial and zoonotic pathogens from ticks and fleas collected from dogs, cats and chickens from six rural communities in Malaysia was undertaken. These communities were made up of mainly the indigenous people of Malaysia, known as the Orang Asli, as well as settlers in oil palm plantations. The presence of Coxiella burnetii, Borrelia, and rickettsial agents, including Rickettsia and Anaplasma, was investigated by performing polymerase chain reaction (PCR) and DNA sequencing. Candidatus Rickettsia senegalensis was detected in one out of eight pools of Ctenocephalides felis fleas. A relapsing fever group Borrelia sp. was identified from one of seven Haemaphysalis hystricis ticks tested. The results from the PCR screening for Anaplasma unexpectedly revealed the presence of Candidatus Midichloria sp., a potential tick endosymbiont, in two out of fourteen Haemaphysalis wellingtoni ticks tested. C. burnetii was not detected in any of the samples tested. The findings here provide evidence for the presence of potentially novel strains of rickettsial and borrelial agents in which their impact on public health risks among the rural communities in Malaysia merit further investigation. The detection of a potential endosymbiont of ticks also suggest that the presence of tick endosymbionts in the region is not fully explored.}, }
@article {pmid33033309, year = {2020}, author = {Park, E and Poulin, R}, title = {Widespread Torix Rickettsia in New Zealand amphipods and the use of blocking primers to rescue host COI sequences.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {16842}, pmid = {33033309}, issn = {2045-2322}, mesh = {Amphipoda/*genetics/*microbiology ; Animals ; *DNA Barcoding, Taxonomic ; DNA, Bacterial/genetics ; Electron Transport Complex IV/*genetics ; Genetic Variation ; Genetics, Population ; *Host Microbial Interactions ; New Zealand ; Phylogeny ; Rickettsia/*genetics/physiology ; Symbiosis/genetics ; }, abstract = {Endosymbionts and intracellular parasites are common in arthropod hosts. As a consequence, (co)amplification of untargeted bacterial sequences has been occasionally reported as a common problem in DNA barcoding. While identifying amphipod species with universal COI primers, we unexpectedly detected rickettsial endosymbionts belonging to the Torix group. To map the distribution and diversity of Rickettsia species among amphipod hosts, we conducted a nationwide molecular screening of seven families of New Zealand freshwater amphipods. In addition to uncovering a diversity of Torix Rickettsia species across multiple amphipod populations from three different families, our research indicates that: (1) detecting Torix Rickettsia with universal primers is not uncommon, (2) obtaining 'Rickettsia COI sequences' from many host individuals is highly likely when a population is infected, and (3) obtaining 'host COI' may not be possible with a conventional PCR if an individual is infected. Because Rickettsia COI is highly conserved across diverse host taxa, we were able to design blocking primers that can be used in a wide range of host species infected with Torix Rickettsia. We propose the use of blocking primers to circumvent problems caused by unwanted amplification of Rickettsia and to obtain targeted host COI sequences for DNA barcoding, population genetics, and phylogeographic studies.}, }
@article {pmid33028894, year = {2020}, author = {Horák, A and Allen, AE and Oborník, M}, title = {Common origin of ornithine-urea cycle in opisthokonts and stramenopiles.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {16687}, pmid = {33028894}, issn = {2045-2322}, mesh = {Animals ; Biological Evolution ; Databases, Genetic ; Ornithine/*metabolism ; Phylogeny ; Stramenopiles/*metabolism ; Symbiosis/physiology ; Urea/*metabolism ; }, abstract = {Eukaryotic complex phototrophs exhibit a colorful evolutionary history. At least three independent endosymbiotic events accompanied by the gene transfer from the endosymbiont to host assembled a complex genomic mosaic. Resulting patchwork may give rise to unique metabolic capabilities; on the other hand, it can also blur the reconstruction of phylogenetic relationships. The ornithine-urea cycle (OUC) belongs to the cornerstone of the metabolism of metazoans and, as found recently, also photosynthetic stramenopiles. We have analyzed the distribution and phylogenetic positions of genes encoding enzymes of the urea synthesis pathway in eukaryotes. We show here that metazoan and stramenopile OUC enzymes share common origins and that enzymes of the OUC found in primary algae (including plants) display different origins. The impact of this fact on the evolution of stramenopiles is discussed here.}, }
@article {pmid33027888, year = {2020}, author = {Bakovic, V and Schebeck, M and Stauffer, C and Schuler, H}, title = {Wolbachia-Mitochondrial DNA Associations in Transitional Populations of Rhagoletis cerasi.}, journal = {Insects}, volume = {11}, number = {10}, pages = {}, pmid = {33027888}, issn = {2075-4450}, abstract = {The endosymbiont Wolbachia can manipulate arthropod host reproduction by inducing cytoplasmic incompatibility (CI), which results in embryonic mortality when infected males mate with uninfected females. A CI-driven invasion of Wolbachia can result in a selective sweep of associated mitochondrial haplotype. The co-inheritance of Wolbachia and host mitochondrial DNA can therefore provide significant information on the dynamics of an ongoing Wolbachia invasion. Therefore, transition zones (i.e., regions where a Wolbachia strain is currently spreading from infected to uninfected populations) represent an ideal area to investigate the relationship between Wolbachia and host mitochondrial haplotype. Here, we studied Wolbachia-mitochondrial haplotype associations in the European cherry fruit fly, Rhagoletis cerasi, in two transition zones in the Czech Republic and Hungary, where the CI-inducing strain wCer2 is currently spreading. The wCer2-infection status of 881 individuals was compared with the two known R. cerasi mitochondrial haplotypes, HT1 and HT2. In accordance with previous studies, wCer2-uninfected individuals were associated with HT1, and wCer2-infected individuals were mainly associated with HT2. We found misassociations only within the transition zones, where HT2 flies were wCer2-uninfected, suggesting the occurrence of imperfect maternal transmission. We did not find any HT1 flies that were wCer2-infected, suggesting that Wolbachia was not acquired horizontally. Our study provides new insights into the dynamics of the early phase of a Wolbachia invasion.}, }
@article {pmid33025290, year = {2020}, author = {Dabravolski, SA}, title = {Evolutionary aspects of the Viridiplantae nitroreductases.}, journal = {Journal, genetic engineering &amp; biotechnology}, volume = {18}, number = {1}, pages = {60}, pmid = {33025290}, issn = {2090-5920}, abstract = {BACKGROUND: Nitroreductases are a family of evolutionarily related proteins catalyzing the reduction of nitro-substituted compounds. Nitroreductases are widespread enzymes, but nearly all modern research and practical application have been concentrated on the bacterial proteins, mainly nitroreductases of Escherichia coli. The main aim of this study is to describe the phylogenic distribution of the nitroreductases in the photosynthetic eukaryotes (Viridiplantae) to highlight their structural similarity and areas for future research and application.<br><br>RESULTS: This study suggests that homologs of nitroreductase proteins are widely presented also in Viridiplantae. Maximum likelihood phylogenetic tree reconstruction method and comparison of the structural models suggest close evolutional relation between cyanobacterial and Viridiplantae nitroreductases.<br><br>CONCLUSIONS: This study provides the first attempt to understand the evolution of nitroreductase protein family in Viridiplantae. Our phylogeny estimation and preservation of the chloroplasts/mitochondrial localization indicate the evolutional origin of the plant nitroreductases from the cyanobacterial endosymbiont. A defined high level of the similarity on the structural level suggests conservancy also for the functions. Directions for the future research and industrial application of the Viridiplantae nitroreductases are discussed.}, }
@article {pmid33024036, year = {2020}, author = {Hague, MTJ and Caldwell, CN and Cooper, BS}, title = {Pervasive Effects of Wolbachia on Host Temperature Preference.}, journal = {mBio}, volume = {11}, number = {5}, pages = {}, pmid = {33024036}, issn = {2150-7511}, support = {R35 GM124701/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Behavior, Animal ; *Body Temperature ; Body Temperature Regulation ; Cytoplasm/microbiology ; Drosophila melanogaster/microbiology/*physiology ; Female ; Genotype ; Host Microbial Interactions/*physiology ; Male ; Phenotype ; Phylogeny ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Heritable symbionts can modify a range of ecologically important host traits, including behavior. About half of all insect species are infected with maternally transmitted Wolbachia, a bacterial endosymbiont known to alter host reproduction, nutrient acquisition, and virus susceptibility. Here, we broadly test the hypothesis that Wolbachia modifies host behavior by assessing the effects of eight different Wolbachia strains on the temperature preference of six Drosophila melanogaster subgroup species. Four of the seven host genotypes infected with A-group Wolbachia strains (wRi in Drosophila simulans, wHa in D. simulans, wSh in Drosophila sechellia, and wTei in Drosophila teissieri) prefer significantly cooler temperatures relative to uninfected genotypes. Contrastingly, when infected with divergent B-group wMau, Drosophila mauritiana prefers a warmer temperature. For most strains, changes to host temperature preference do not alter Wolbachia titer. However, males infected with wSh and wTei tend to experience an increase in titer when shifted to a cooler temperature for 24 h, suggesting that Wolbachia-induced changes to host behavior may promote bacterial replication. Our results indicate that Wolbachia modifications to host temperature preference are likely widespread, which has important implications for insect thermoregulation and physiology. Understanding the fitness consequences of these Wolbachia effects is crucial for predicting evolutionary outcomes of host-symbiont interactions, including how Wolbachia spreads to become common.IMPORTANCE Microbes infect a diversity of species, influencing the performance and fitness of their hosts. Maternally transmitted Wolbachia bacteria infect most insects and other arthropods, making these bacteria some of the most common endosymbionts in nature. Despite their global prevalence, it remains mostly unknown how Wolbachia influence host physiology and behavior to proliferate. We demonstrate pervasive effects of Wolbachia on Drosophila temperature preference. Most hosts infected with A-group Wolbachia prefer cooler temperatures, whereas the one host species infected with divergent B-group Wolbachia prefers warmer temperatures, relative to uninfected genotypes. Changes to host temperature preference generally do not alter Wolbachia abundance in host tissues, but for some A-group strains, adult males have increased Wolbachia titer when shifted to a cooler temperature. This suggests that Wolbachia-induced changes to host behavior may promote bacterial replication. Our results help elucidate the impact of endosymbionts on their hosts amid the global Wolbachia pandemic.}, }
@article {pmid33022020, year = {2020}, author = {Coates, LC and Mahoney, J and Ramsey, JS and Warwick, E and Johnson, R and MacCoss, MJ and Krasnoff, SB and Howe, KJ and Moulton, K and Saha, S and Mueller, LA and Hall, DG and Shatters, RG and Heck, ML and Slupsky, CM}, title = {Development on Citrus medica infected with 'Candidatus Liberibacter asiaticus' has sex-specific and -nonspecific impacts on adult Diaphorina citri and its endosymbionts.}, journal = {PloS one}, volume = {15}, number = {10}, pages = {e0239771}, pmid = {33022020}, issn = {1932-6203}, mesh = {Animals ; Citrus/metabolism/*microbiology/physiology ; Female ; Hemiptera/metabolism/*microbiology/physiology ; Insect Vectors/metabolism/*microbiology/physiology ; Male ; Metabolome/physiology ; Microbiota/physiology ; Oxidative Stress/physiology ; Plant Diseases/*microbiology ; Proteome/metabolism ; Rhizobiaceae/*pathogenicity/*physiology ; Symbiosis/*physiology ; Transcriptome/physiology ; }, abstract = {Huanglongbing (HLB) is a deadly, incurable citrus disease putatively caused by the unculturable bacterium, 'Candidatus Liberibacter asiaticus' (CLas), and transmitted by Diaphorina citri. Prior studies suggest D. citri transmits CLas in a circulative and propagative manner; however, the precise interactions necessary for CLas transmission remain unknown, and the impact of insect sex on D. citri-CLas interactions is poorly understood despite reports of sex-dependent susceptibilities to CLas. We analyzed the transcriptome, proteome, metabolome, and microbiome of male and female adult D. citri reared on healthy or CLas-infected Citrus medica to determine shared and sex-specific responses of D. citri and its endosymbionts to CLas exposure. More sex-specific than shared D. citri responses to CLas were observed, despite there being no difference between males and females in CLas density or relative abundance. CLas exposure altered the abundance of proteins involved in immunity and cellular and oxidative stress in a sex-dependent manner. CLas exposure impacted cuticular proteins and enzymes involved in chitin degradation, as well as energy metabolism and abundance of the endosymbiont 'Candidatus Profftella armatura' in both sexes similarly. Notably, diaphorin, a toxic Profftella-derived metabolite, was more abundant in both sexes with CLas exposure. The responses reported here resulted from a combination of CLas colonization of D. citri as well as the effect of CLas infection on C. medica. Elucidating these impacts on D. citri and their endosymbionts contributes to our understanding of the HLB pathosystem and identifies the responses potentially critical to limiting or promoting CLas acquisition and propagation in both sexes.}, }
@article {pmid33021711, year = {2021}, author = {Shan, H and Liu, Y and Luan, J and Liu, S}, title = {New insights into the transovarial transmission of the symbiont Rickettsia in whiteflies.}, journal = {Science China. Life sciences}, volume = {64}, number = {7}, pages = {1174-1186}, pmid = {33021711}, issn = {1869-1889}, mesh = {Animals ; Disease Transmission, Infectious ; Hemiptera/*microbiology ; Infectious Disease Transmission, Vertical ; Oocytes/*microbiology ; Oogenesis ; Rickettsia/*pathogenicity ; Symbiosis ; }, abstract = {Endosymbiont transmission via eggs to future host generations has been recognized as the main strategy for its persistence in insect hosts; however, the mechanisms for transmission have yet to be elucidated. Here, we describe the dynamic locations of Rickettsia in the ovarioles and eggs during oogenesis and embryogenesis in a globally significant pest whitefly Bemisia tabaci. Field populations of the whitefly have a high prevalence of Rickettsia, and in all Rickettsia-infected individuals, the bacterium distributes in the body cavity of the host, especially in the midgut, fat body, hemocytes, hemolymph, and near bacteriocytes. The distribution of Rickettsia was subjected to dynamic changes in the ovary during oogenesis, and our ultrastructural observations indicated that the bacteria infect host ovarioles during early developmental stages via two routes: (i) invasion of the tropharium by endocytosis and then transmission into vitellarium via nutritive cord and (ii) entry into vitellarium by hijacking bacteriocyte translocation. Most of the Rickettsia are degraded in the oocyte cytoplasm in late-stage oogenesis. However, a few reside beneath the vitelline envelope of mature eggs, spread into the embryo, and proliferate during embryogenesis to sustain high-fidelity transmission to the next generation. Our findings provide novel insights into the maternal transmission underpinning the persistence and spread of insect symbionts.}, }
@article {pmid33016322, year = {2021}, author = {Moreno, E}, title = {The one hundred year journey of the genus Brucella (Meyer and Shaw 1920).}, journal = {FEMS microbiology reviews}, volume = {45}, number = {1}, pages = {}, doi = {10.1093/femsre/fuaa045}, pmid = {33016322}, issn = {1574-6976}, mesh = {Animals ; Brucella/*classification/genetics/pathogenicity ; Brucellosis/*microbiology ; Host Specificity ; Humans ; Terminology as Topic ; Virulence Factors/genetics ; }, abstract = {The genus Brucella, described by Meyer and Shaw in 1920, comprises bacterial pathogens of veterinary and public health relevance. For 36 years, the genus came to include three species that caused brucellosis in livestock and humans. In the second half of the 20th century, bacteriologists discovered five new species and several 'atypical' strains in domestic animals and wildlife. In 1990, the Brucella species were recognized as part of the Class Alphaproteobacteria, clustering with pathogens and endosymbionts of animals and plants such as Bartonella, Agrobacterium and Ochrobactrum; all bacteria that live in close association with eukaryotic cells. Comparisons with Alphaproteobacteria contributed to identify virulence factors and to establish evolutionary relationships. Brucella members have two circular chromosomes, are devoid of plasmids, and display close genetic relatedness. A proposal, asserting that all brucellae belong to a single species with several subspecies debated for over 70 years, was ultimately rejected in 2006 by the subcommittee of taxonomy, based on scientific, practical, and biosafety considerations. Following this, the nomenclature of having multiples Brucella species prevailed and defined according to their molecular characteristics, host preference, and virulence. The 100-year history of the genus corresponds to the chronicle of scientific efforts and the struggle for understanding brucellosis.}, }
@article {pmid33016318, year = {2020}, author = {Moussa, A and Passera, A and Sanna, F and Faccincani, M and Casati, P and Bianco, PA and Mori, N and Quaglino, F}, title = {Bacterial microbiota associated with insect vectors of grapevine Bois noir disease in relation to phytoplasma infection.}, journal = {FEMS microbiology ecology}, volume = {96}, number = {11}, pages = {}, doi = {10.1093/femsec/fiaa203}, pmid = {33016318}, issn = {1574-6941}, mesh = {Insect Vectors ; *Microbiota ; Phylogeny ; Phytoplasma Disease ; Plant Diseases ; *Vitis ; }, abstract = {Bois noir is a grapevine disease causing severe yield loss in vineyards worldwide. It is associated with 'Candidatus Phytoplasma solani', a phloem-limited bacterium transmitted by polyphagous insects. Due to its complex epidemiology, it is difficult to organize effective containment measures. This study aimed to describe the bacterial microbiota associated with 'Candidatus Phytoplasma solani' infected and non-infected insect hosts and vectors to investigate if phytoplasma presence can shape the microbiota. Alpha-diversity analysis showed a low microbiota diversity in these insects, in which few genera were highly abundant. Beta-diversity analysis revealed that the xylem- and phloem-feeding behavior influences the microbiota structure. Moreover, it highlighted that phytoplasma infection is associated with a restructuring of microbiota exclusively in Deltocephalinae insect vectors. Obtained data showed that 'Candidatus Phytoplasma solani' may have adverse effects on the endosymbionts Sulcia and Wolbachia, suggesting a possible fitness modification in the insects. The phytoplasma-antagonistic Dyella was not found in any of the examined insect species. The results indicate an interesting perspective regarding the microbial signatures associated with xylem- and phloem-feeding insects, and determinants that could be relevant to establish whether an insect species can be a vector or not, opening up new avenues for developing microbial resource management-based approaches.}, }
@article {pmid33014260, year = {2020}, author = {Nakayama, T and Takahashi, K and Kamikawa, R and Iwataki, M and Inagaki, Y and Tanifuji, G}, title = {Putative genome features of relic green alga-derived nuclei in dinoflagellates and future perspectives as model organisms.}, journal = {Communicative &amp; integrative biology}, volume = {13}, number = {1}, pages = {84-88}, pmid = {33014260}, issn = {1942-0889}, abstract = {Nucleomorphs, relic endosymbiont nuclei, have been studied as a model to elucidate the evolutionary process of integrating a eukaryotic endosymbiont into a host cell organelle. Recently, we reported two new dinoflagellates possessing nucleomorphs, and proposed them as new models in this research field based on the following findings: genome integration processes are incomplete, and the origins of the endosymbiont lineages were pinpointed. Here, we focused on the nucleomorph genome features in the two green dinoflagellates and compared them with those of the known nucleomorph genomes of cryptophytes and chlorarachniophytes. All nucleomorph genomes showed similar trends suggesting convergent evolution. However, the number of nucleomorph genes that are unrelated to housekeeping machineries in the two green dinoflagellates are greater than the numbers in cryptophytes and chlorarachniophytes, providing additional evidence that their genome reduction has not progressed much compared with those of cryptophytes and chlorarachniophytes. Finally, potential future work is discussed.}, }
@article {pmid33002324, year = {2021}, author = {Izraeli, Y and Lalzar, M and Netanel, N and Mozes-Daube, N and Steinberg, S and Chiel, E and Zchori-Fein, E}, title = {Wolbachia influence on the fitness of Anagyrus vladimiri (Hymenoptera: Encyrtidae), a bio-control agent of mealybugs.}, journal = {Pest management science}, volume = {77}, number = {2}, pages = {1023-1034}, doi = {10.1002/ps.6117}, pmid = {33002324}, issn = {1526-4998}, mesh = {Animals ; Female ; *Hymenoptera ; Multilocus Sequence Typing ; Reproduction ; Symbiosis ; *Wasps ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Like numerous other animals, biocontrol agents (BCAs) of arthropod pests carry various microorganisms that may have diverse effects on the biology of their eukaryote hosts. We postulated that it is possible to improve the efficacy of BCAs by manipulating the composition of their associated microbiota. The parasitoid wasp Anagyrus vladimiri (Hymenoptera: Encyrtidae) from a mass-rearing facility was chosen for testing this hypothesis.<br><br>RESULTS: High-throughput sequencing analysis indicated that fungal abundance in A. vladimiri was low and variable, whereas the bacterial community was dominated by the endosymbiont Wolbachia. Wolbachia was fixed in the mass-rearing population, whereas in field-collected A. vladimiri Wolbachia's prevalence was only approximately 20%. Identification of Wolbachia strains from the two populations by Multi Locus Sequence Typing, revealed two closely related but unique strains. A series of bioassays with the mass-rearing Wolbachia-fixed (W[+]) and a derived antibiotic-treated Wolbachia-free (W[-]) lines revealed that: (i) Wolbachia does not induce reproductive manipulations; (ii) W[-] females have higher fecundity when reared individually, but not when reared with conspecifics; (iii) W[+] females outcompete W[-] when they share hosts for oviposition; (iv) longevity and developmental time were similar in both lines.<br><br>CONCLUSIONS: The findings suggest that W[+] A. vladimiri have no clear fitness benefit under mass-rearing conditions and may be disadvantageous under lab-controlled conditions. In a broader view, the results suggest that augmentative biological control can benefit from manipulation of the microbiome of natural enemies.}, }
@article {pmid33002000, year = {2020}, author = {Sorroche, F and Morales, V and Mouffok, S and Pichereaux, C and Garnerone, AM and Zou, L and Soni, B and Carpéné, MA and Gargaros, A and Maillet, F and Burlet-Schiltz, O and Poinsot, V and Polard, P and Gough, C and Batut, J}, title = {The ex planta signal activity of a Medicago ribosomal uL2 protein suggests a moonlighting role in controlling secondary rhizobial infection.}, journal = {PloS one}, volume = {15}, number = {10}, pages = {e0235446}, pmid = {33002000}, issn = {1932-6203}, mesh = {Coinfection/prevention &amp; control ; Ethylenes/metabolism ; Gene Expression Regulation, Plant ; Genes, Plant ; *Medicago truncatula/genetics/metabolism/microbiology ; Plant Immunity/genetics ; Plant Proteins/genetics/*metabolism ; Plant Root Nodulation/physiology ; Plant Roots/metabolism/microbiology ; Ribosomal Proteins/genetics/*metabolism ; Root Nodules, Plant/*metabolism/microbiology ; Signal Transduction ; Sinorhizobium meliloti/*metabolism ; Symbiosis ; }, abstract = {We recently described a regulatory loop, which we termed autoregulation of infection (AOI), by which Sinorhizobium meliloti, a Medicago endosymbiont, downregulates the root susceptibility to secondary infection events via ethylene. AOI is initially triggered by so-far unidentified Medicago nodule signals named signal 1 and signal 1' whose transduction in bacteroids requires the S. meliloti outer-membrane-associated NsrA receptor protein and the cognate inner-membrane-associated adenylate cyclases, CyaK and CyaD1/D2, respectively. Here, we report on advances in signal 1 identification. Signal 1 activity is widespread as we robustly detected it in Medicago nodule extracts as well as in yeast and bacteria cell extracts. Biochemical analyses indicated a peptidic nature for signal 1 and, together with proteomic analyses, a universally conserved Medicago ribosomal protein of the uL2 family was identified as a candidate signal 1. Specifically, MtRPuL2A (MtrunA17Chr7g0247311) displays a strong signal activity that requires S. meliloti NsrA and CyaK, as endogenous signal 1. We have shown that MtRPuL2A is active in signaling only in a non-ribosomal form. A Medicago truncatula mutant in the major symbiotic transcriptional regulator MtNF-YA1 lacked most signal 1 activity, suggesting that signal 1 is under developmental control. Altogether, our results point to the MtRPuL2A ribosomal protein as the candidate for signal 1. Based on the Mtnf-ya1 mutant, we suggest a link between root infectiveness and nodule development. We discuss our findings in the context of ribosomal protein moonlighting.}, }
@article {pmid33000998, year = {2020}, author = {Noutoshi, Y and Toyoda, A and Ishii, T and Saito, K and Watanabe, M and Kawaguchi, A}, title = {Complete Genome Sequence Data of Nonpathogenic and Nonantagonistic Strain of Rhizobium vitis VAR06-30 Isolated From Grapevine Rhizosphere.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {33}, number = {11}, pages = {1283-1285}, doi = {10.1094/MPMI-07-20-0182-A}, pmid = {33000998}, issn = {0894-0282}, mesh = {*Genome, Bacterial ; Phylogeny ; Plant Tumors/*microbiology ; *Rhizobium/genetics ; Rhizosphere ; Vitis/*microbiology ; }, abstract = {Rhizobium (Agrobacterium) is one genus in the family Rhizobiaceae. Most of the species are epi- or endophytic bacteria which include tumorigenic or rhizogenic pathogens, root nodule bacteria, and commensal endosymbionts. Rhizobium vitis strain VAR06-30 is a commensal bacterium without pathogenicity which was isolated from a rootstock of grapevine in Japan. It also does not have antagonistic activity to the pathogenic strain of R. vitis. Here, we show the complete genome sequence data with annotation of R. vitis VAR06-30 which was analyzed by sequence reads obtained from both PacBio and Illumina platforms. This genome sequence would contribute to the understanding of evolutionary lineage and characteristics of Rhizobium commensal bacteria.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.}, }
@article {pmid32994291, year = {2020}, author = {Lu, Y and Jiang, J and Zhao, H and Han, X and Xiang, Y and Zhou, W}, title = {Clade-Specific Sterol Metabolites in Dinoflagellate Endosymbionts Are Associated with Coral Bleaching in Response to Environmental Cues.}, journal = {mSystems}, volume = {5}, number = {5}, pages = {}, pmid = {32994291}, issn = {2379-5077}, abstract = {Cnidarians cannot synthesize sterols (which play essential roles in growth and development) de novo but often use sterols acquired from endosymbiotic dinoflagellates. While sterol availability can impact the mutualistic interaction between coral host and algal symbiont, the biosynthetic pathways (in the dinoflagellate endosymbionts) and functional roles of sterols in these symbioses are poorly understood. In this study, we found that itraconazole, which perturbs sterol metabolism by inhibiting the sterol 14-demethylase CYP51 in dinoflagellates, induces bleaching of the anemone Heteractis crispa and that bleaching perturbs sterol metabolism of the dinoflagellate. While Symbiodiniaceae have clade-specific sterol metabolites, they share features of the common sterol biosynthetic pathway but with distinct architecture and substrate specificity features of participating enzymes. Tracking sterol profiles and transcripts of enzymes involved in sterol biosynthesis across time in response to different environmental cues revealed similarities and idiosyncratic features of sterol synthesis in the endosymbiont Breviolum minutum Exposure of algal cultures to high levels of light, heat, and acidification led to alterations in sterol synthesis, including blocks through downregulation of squalene synthase transcript levels accompanied by marked growth reductions.IMPORTANCE These results indicate that sterol metabolites in Symbiodiniaceae are clade specific, that their biosynthetic pathways share architectural and substrate specificity features with those of animals and plants, and that environmental stress-specific perturbation of sterol biosynthesis in dinoflagellates can impair a key mutualistic partnership for healthy reefs.}, }
@article {pmid32993944, year = {2020}, author = {Sperling, J and MacDonald, Z and Normandeau, J and Merrill, E and Sperling, F and Magor, K}, title = {Within-population diversity of bacterial microbiomes in winter ticks (Dermacentor albipictus).}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {6}, pages = {101535}, doi = {10.1016/j.ttbdis.2020.101535}, pmid = {32993944}, issn = {1877-9603}, mesh = {Alberta ; Animals ; Bacteria/*isolation &amp; purification ; Dermacentor/*microbiology ; Microbiota/*genetics ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; }, abstract = {The bacterial microbiome of ticks is notoriously diverse, but the factors leading to this diversity are poorly understood. We sequenced bacterial 16S rRNA amplicons from individual winter ticks, Dermacentor albipictus, to assess whether their one-host life cycle is associated with reduced bacterial diversity. On average, about 100 bacterial genera were found for individual ticks. Francisella-like endosymbiont (FLE) dominated bacterial communities, particularly in female ticks and in ticks that had fed. The remainder of the winter tick microbiome was highly variable. In addition to FLE, the main bacterial genera associated with winter ticks on elk were Pseudomonas, Ehrlichia, Asinibacterium, Acinetobacter and Streptococcus, although sequences associated with hundreds of other minor bacterial genera were detected. A complex interaction between richness and evenness was revealed in comparisons among tick life stages, using the Hill number series to show trends in diversity with decreasing emphasis on rare members of the assemblage. Male ticks had a significantly greater number of bacterial genera than females or nymphs, while males had greater evenness than females and similar evenness to nymphs. We intentionally sampled ticks from a single host species, North American elk, from a single location in Alberta, Canada, to constrain the ecological and blood meal variation that individuals experience through their life cycle. In spite of this, we found that the number of bacterial genera detected in this one-host tick system was remarkably diverse. The high taxonomic variability of the minor components of the winter tick microbiome suggests that this part of their microbiome diversity should be examined for functional significance.}, }
@article {pmid32993936, year = {2020}, author = {Tufts, DM and Sameroff, S and Tagliafierro, T and Jain, K and Oleynik, A and VanAcker, MC and Diuk-Wasser, MA and Lipkin, WI and Tokarz, R}, title = {A metagenomic examination of the pathobiome of the invasive tick species, Haemaphysalis longicornis, collected from a New York City borough, USA.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {6}, pages = {101516}, doi = {10.1016/j.ttbdis.2020.101516}, pmid = {32993936}, issn = {1877-9603}, mesh = {Animals ; Ixodidae/growth &amp; development/*microbiology/virology ; Larva/growth &amp; development/microbiology/virology ; *Metagenome ; Metagenomics ; *Microbiota ; New York City ; Nymph/growth &amp; development/microbiology/virology ; *Virome ; }, abstract = {Haemaphysalis longicornis, the Asian longhorned tick, is an invasive tick species that has spread rapidly across the northeastern and southeastern regions of the United States in recent years. This invasive pest species, known to transmit several tick-borne pathogens in its native range, is a potential threat to wildlife, livestock, domestic animals, and humans. Questing larval (n = 25), nymph (n = 10), and adult (n = 123), along with host-derived adult (n = 25) H. longicornis ticks were collected from various locations on Staten Island, NY. The pathobiome of each specimen was examined using two different high throughput sequencing approaches, virus enrichment and shotgun metagenomics. An average of 45,828,061 total reads per sample were recovered from the virus enriched samples and an average of 11,381,144 total reads per sample were obtained using shotgun metagenomics. Aside from endogenous viral sequences, no viruses were identified through either approach. Through shotgun metagenomics, Coxiella-like bacteria, Legionella, Sphingomonas, and other bacterial species were recovered. The Coxiella-like agent was ubiquitous and present at high abundances in all samples, suggesting it may be an endosymbiont. The other bacterial agents are not known to be transmitted by ticks. From these analyses, H. longicornis do not appear to host any endemic human tick-borne pathogens in the New York City region.}, }
@article {pmid32993931, year = {2020}, author = {Al-Khafaji, AM and Bell-Sakyi, L and Fracasso, G and Luu, L and Heylen, D and Matthysen, E and Oteo, JA and Palomar, AM}, title = {Isolation of Candidatus Rickettsia vini from Belgian Ixodes arboricola ticks and propagation in tick cell lines.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {6}, pages = {101511}, pmid = {32993931}, issn = {1877-9603}, support = {BB/N023889/2/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/P024270/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Belgium ; Cell Line ; Female ; Genes, Bacterial ; Ixodes/*microbiology ; Male ; Phylogeny ; Rickettsia/classification/*isolation &amp; purification ; }, abstract = {Candidatus Rickettsia vini was originally detected in Ixodes arboricola ticks from Spain, and subsequently reported from several other Western Palearctic countries including Belgium. Recently, the bacterium was isolated in mammalian (Vero) cell culture from macerated male I. arboricola from Czech Republic, but there have been no reports of propagation in tick cells. Here we report isolation in a tick cell line of three strains of Ca. R. vini from I. arboricola collected from nests of great tits (Parus major) in Belgium. Internal organs of one male and two engorged female ticks were dissected aseptically, added to cultures of the Rhipicephalus microplus cell line BME/CTVM23 and incubated at 28 °C. Rickettsia-like bacteria were first seen in Giemsa-stained cytocentrifuge smears between 2 and 15 weeks later. Two of the isolates grew rapidly, destroying the tick cells within 2-4 weeks of onward passage in BME/CTVM23 cells, while the third isolate grew much more slowly, only requiring subculture at 4-5-month intervals. PCR amplification of bacterial 16S rRNA and Rickettsia gltA, sca4, ompB, ompA and 17-kDa genes revealed that all three isolates were Ca. R. vini, with 100 % identity to each other and to published Ca. R. vini sequences from other geographical locations. Transmission electron microscopy revealed typical single Rickettsia bacteria in the cytoplasm of BME/CTVM23 cells. The Ca. R. vini strain isolated from the male I. arboricola tick, designated Boshoek1, was tested for ability to grow in a panel of Ixodes ricinus, Ixodes scapularis and R. microplus cell lines and in Vero cells. The Boshoek1 strain grew rapidly, causing severe cytopathic effect, in the R. microplus line BME26, the I. ricinus line IRE11 and Vero cells, more slowly in the I. ricinus line IRE/CTVM19, possibly established a low-level infection in the I. ricinus line IRE/CTVM20, and failed to infect cells of any of four I. scapularis lines over a 12-week observation period. This study confirmed the applicability of the simple tick organ-cell line co-cultivation technique for isolation of tick-borne Rickettsia spp. using BME/CTVM23 cells.}, }
@article {pmid32972080, year = {2020}, author = {Noda, T and Okude, G and Meng, XY and Koga, R and Moriyama, M and Fukatsu, T}, title = {Bacteriocytes and Blattabacterium Endosymbionts of the German Cockroach Blattella germanica, the Forest Cockroach Blattella nipponica, and Other Cockroach Species.}, journal = {Zoological science}, volume = {37}, number = {5}, pages = {399-410}, doi = {10.2108/zs200054}, pmid = {32972080}, issn = {0289-0003}, mesh = {Animals ; Bacteroidetes/*physiology ; Cockroaches/*cytology/*microbiology ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {Cockroaches are commonly found in human residences and notorious as hygienic and nuisance pests. Notably, however, no more than 30 cockroach species are regarded as pests, while the majority of 4,500 cockroaches in the world are living in forest environments with little relevance to human life. Why some cockroaches have exceptionally adapted to anthropic environments and established pest status is of interest. Here we investigated the German cockroach Blattella germanica, which is a cosmopolitan pest species, and the forest cockroach Blattella nipponica, which is a wild species closely related to B. germanica. In contrast to easy rearing of B. germanica, laboratory rearing of B. nipponica was challenging-several trials enabled us to keep the insects for up to three months. We particularly focused on the distribution patterns of specialized cells, bacteriocytes, for harboring endosymbiotic Blattabacterium, which has been suggested to contribute to host's nitrogen metabolism and recycling, during the postembryonic development of the insects. The bacteriocytes were consistently localized to visceral fat bodies filling the abdominal body cavity, where a number of single bacteriocytes were scattered among the adipocytes, throughout the developmental stages in both females and males. The distribution patterns of the bacteriocytes were quite similar between B. germanica and B. nipponica, and also among other diverse cockroach species, plausibly reflecting the highly conserved cockroach-Blattabacterium symbiotic association over evolutionary time. Our study lays a foundation to experimentally investigate the origin and the processes of urban pest evolution, on account of possible involvement of microbial associates.}, }
@article {pmid32970802, year = {2020}, author = {Li, TP and Zha, SS and Zhou, CY and Gong, JT and Zhu, YX and Zhang, X and Xi, Z and Hong, XY}, title = {Newly introduced Cardinium endosymbiont reduces microbial diversity in the rice brown planthopper Nilaparvata lugens.}, journal = {FEMS microbiology ecology}, volume = {96}, number = {12}, pages = {}, doi = {10.1093/femsec/fiaa194}, pmid = {32970802}, issn = {1574-6941}, mesh = {Animals ; Bacteria/genetics ; Bacteroidetes/genetics ; Female ; *Hemiptera ; Male ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Symbiotic microorganisms in invertebrates play vital roles in host ecology and evolution. Cardinium, a common intracellular symbiont, is transinfected into the important agricultural pest Nilaparvata lugens (rice brown planthopper) to regulate its reproduction, but how this impacts its microbial community is unknown. Here, we characterized the bacterial microbiota from N. lugens, with or without Cardinium, at different developmental stages and in various adult tissues using 16S ribosomal ribonucleic acid (16S rRNA) gene sequencing. Upon infection with Cardinium, we found that microbial diversity in the different developmental stages of N. lugens (especially females), and in female midguts and male testes, was lower than that in the uninfected control. There was a negative correlation between Cardinium and most related genera and between Bacteroidetes and Proteobacteria. Although the microbial structure varied during Cardinium infection, Acinetobacter spp. were a core microbiome genus. The Cardinium infection enhanced the relative density of midgut-associated Acinetobacter spp., with both bacteria exhibiting tissue-specific tropism. In addition, this infection caused the changes of main microbial functions in N. lugens. These results offer insights into the effects of alien (i.e. newly introduced from other organism) Cardinium infection on N. lugens-associated microbiotas, aiding in the development of transinfected endosymbionts for pest control.}, }
@article {pmid32968175, year = {2020}, author = {Shao, M and Sun, C and Liu, X and Wang, X and Li, W and Wei, X and Li, Q and Ju, J}, title = {Upregulation of a marine fungal biosynthetic gene cluster by an endobacterial symbiont.}, journal = {Communications biology}, volume = {3}, number = {1}, pages = {527}, pmid = {32968175}, issn = {2399-3642}, mesh = {Actinobacteria/*genetics/metabolism/physiology ; Alcaligenes faecalis/*genetics/metabolism/physiology ; Anti-Bacterial Agents/biosynthesis/pharmacology ; Aquatic Organisms/*genetics ; Geologic Sediments/microbiology ; Microbial Sensitivity Tests ; Multigene Family/*physiology ; Symbiosis ; Up-Regulation ; }, abstract = {Fungal-bacterial associations are present in nature, playing important roles in ecological, evolutionary and medicinal processes. Here we report a fungus-bacterial symbiont from marine sediment. The bacterium lives inside the fungal mycelium yet is robust enough to survive independent of its host; the independently grown bacterium can infect the fungal host in vitro and continue to grow progenitively. The bacterial symbiont modulates the fungal host to biosynthesize a polyketide antimicrobial, spiromarmycin. Spiromarmycin appears to endow upon the symbiont pair a protective/defensive means of warding off competitor organisms, be they prokaryotic or eukaryotic microorganisms. Genomic analyses revealed the spiromarmycin biosynthetic machinery to be encoded, not by the bacterium, but rather the fungal host. This unique fungal-bacterial symbiotic relationship and the molecule/s resulting from it dramatically expand our knowledge of marine microbial diversity and shed important insights into endosymbionts and fungal-bacterial relationships.}, }
@article {pmid32961808, year = {2020}, author = {Salcedo-Porras, N and Umaña-Diaz, C and Bitencourt, ROB and Lowenberger, C}, title = {The Role of Bacterial Symbionts in Triatomines: An Evolutionary Perspective.}, journal = {Microorganisms}, volume = {8}, number = {9}, pages = {}, pmid = {32961808}, issn = {2076-2607}, abstract = {Insects have established mutualistic symbiotic interactions with microorganisms that are beneficial to both host and symbiont. Many insects have exploited these symbioses to diversify and expand their ecological ranges. In the Hemiptera (i.e., aphids, cicadas, and true bugs), symbioses have established and evolved with obligatory essential microorganisms (primary symbionts) and with facultative beneficial symbionts (secondary symbionts). Primary symbionts are usually intracellular microorganisms found in insects with specialized diets such as obligate hematophagy or phytophagy. Most Heteroptera (true bugs), however, have gastrointestinal (GI) tract extracellular symbionts with functions analogous to primary endosymbionts. The triatomines, are vectors of the human parasite, Trypanosoma cruzi. A description of their small GI tract microbiota richness was based on a few culturable microorganisms first described almost a century ago. A growing literature describes more complex interactions between triatomines and bacteria with properties characteristic of both primary and secondary symbionts. In this review, we provide an evolutionary perspective of beneficial symbioses in the Hemiptera, illustrating the context that may drive the evolution of symbioses in triatomines. We highlight the diversity of the triatomine microbiota, bacterial taxa with potential to be beneficial symbionts, the unique characteristics of triatomine-bacteria symbioses, and the interactions among trypanosomes, microbiota, and triatomines.}, }
@article {pmid32957540, year = {2020}, author = {Ghafar, A and Khan, A and Cabezas-Cruz, A and Gauci, CG and Niaz, S and Ayaz, S and Mateos-Hernández, L and Galon, C and Nasreen, N and Moutailler, S and Gasser, RB and Jabbar, A}, title = {An Assessment of the Molecular Diversity of Ticks and Tick-Borne Microorganisms of Small Ruminants in Pakistan.}, journal = {Microorganisms}, volume = {8}, number = {9}, pages = {}, pmid = {32957540}, issn = {2076-2607}, abstract = {This study investigated ticks and tick-borne microorganisms of small ruminants from five districts of the Federally Administered Tribal Area (FATA) of Pakistan. Morphological (n = 104) and molecular (n = 54) characterization of the ticks revealed the presence of six ixodid ticks: Rhipicephalus (Rh.) haemaphysaloides, Rh. microplus, Rh. turanicus, Haemaphysalis (Hs.) punctata, Hs. sulcata and Hyalomma anatolicum. Phylogenetic analyses of nucleotide sequence data for two mitochondrial (16S and cytochrome c oxidase 1) and one nuclear (second internal transcribed spacer) DNA regions provided strong support for the grouping of the six tick species identified in this study. Microfluidic real-time PCR, employing multiple pre-validated nuclear and mitochondrial genetic markers, detected 11 potential pathogens and endosymbionts in 72.2% of the ticks (n = 54) tested. Rickettsia (R.) massiliae was the most common pathogen found (42.6% of ticks) followed by Theileria spp. (33.3%), Anaplasma (A.) ovis and R. slovaca (25.9% each). Anaplasma centrale, A. marginale, Ehrlichia spp., R. aeschlimannii, R. conorii and endosymbionts (Francisella- and Coxiella-like) were detected at much lower rates (1.9-22.2%) in ticks. Ticks from goats (83.9%) carried significantly higher microorganisms than those from sheep (56.5%). This study demonstrates that ticks of small ruminants from the FATA are carrying multiple microorganisms of veterinary and medical health significance and provides the basis for future investigations of ticks and tick-borne diseases of animals and humans in this and neighboring regions.}, }
@article {pmid32956455, year = {2021}, author = {Ip, JC and Xu, T and Sun, J and Li, R and Chen, C and Lan, Y and Han, Z and Zhang, H and Wei, J and Wang, H and Tao, J and Cai, Z and Qian, PY and Qiu, JW}, title = {Host-Endosymbiont Genome Integration in a Deep-Sea Chemosymbiotic Clam.}, journal = {Molecular biology and evolution}, volume = {38}, number = {2}, pages = {502-518}, pmid = {32956455}, issn = {1537-1719}, support = {EP-C-18-007/EPA/EPA/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Bivalvia/*microbiology/physiology ; *Gene Transfer, Horizontal ; *Genome ; Hemoglobins/chemistry/genetics ; Hydrothermal Vents/*microbiology ; Immune System ; Phylogeny ; Piscirickettsiaceae/genetics ; *Symbiosis ; }, abstract = {Endosymbiosis with chemosynthetic bacteria has enabled many deep-sea invertebrates to thrive at hydrothermal vents and cold seeps, but most previous studies on this mutualism have focused on the bacteria only. Vesicomyid clams dominate global deep-sea chemosynthesis-based ecosystems. They differ from most deep-sea symbiotic animals in passing their symbionts from parent to offspring, enabling intricate coevolution between the host and the symbiont. Here, we sequenced the genomes of the clam Archivesica marissinica (Bivalvia: Vesicomyidae) and its bacterial symbiont to understand the genomic/metabolic integration behind this symbiosis. At 1.52 Gb, the clam genome encodes 28 genes horizontally transferred from bacteria, a large number of pseudogenes and transposable elements whose massive expansion corresponded to the timing of the rise and subsequent divergence of symbiont-bearing vesicomyids. The genome exhibits gene family expansion in cellular processes that likely facilitate chemoautotrophy, including gas delivery to support energy and carbon production, metabolite exchange with the symbiont, and regulation of the bacteriocyte population. Contraction in cellulase genes is likely adaptive to the shift from phytoplankton-derived to bacteria-based food. It also shows contraction in bacterial recognition gene families, indicative of suppressed immune response to the endosymbiont. The gammaproteobacterium endosymbiont has a reduced genome of 1.03 Mb but retains complete pathways for sulfur oxidation, carbon fixation, and biosynthesis of 20 common amino acids, indicating the host's high dependence on the symbiont for nutrition. Overall, the host-symbiont genomes show not only tight metabolic complementarity but also distinct signatures of coevolution allowing the vesicomyids to thrive in chemosynthesis-based ecosystems.}, }
@article {pmid32943577, year = {2020}, author = {Becker, DM and Silbiger, NJ}, title = {Nutrient and sediment loading affect multiple facets of functionality in a tropical branching coral.}, journal = {The Journal of experimental biology}, volume = {223}, number = {Pt 21}, pages = {}, doi = {10.1242/jeb.225045}, pmid = {32943577}, issn = {1477-9145}, mesh = {Animals ; *Anthozoa ; Chlorophyll A ; Coral Reefs ; Ecosystem ; Nutrients ; Polynesia ; }, abstract = {Coral reefs, one of the most diverse ecosystems in the world, face increasing pressures from global and local anthropogenic stressors. Therefore, a better understanding of the ecological ramifications of warming and land-based inputs (e.g. sedimentation and nutrient loading) on coral reef ecosystems is necessary. In this study, we measured how a natural nutrient and sedimentation gradient affected multiple facets of coral functionality, including endosymbiont and coral host response variables, holobiont metabolic responses and percent cover of Pocillopora acuta colonies in Mo'orea, French Polynesia. We used thermal performance curves to quantify the relationship between metabolic rates and temperature along the environmental gradient. We found that algal endosymbiont percent nitrogen content, endosymbiont densities and total chlorophyll a content increased with nutrient input, while endosymbiont nitrogen content per cell decreased, likely representing competition among the algal endosymbionts. Nutrient and sediment loading decreased coral metabolic responses to thermal stress in terms of their thermal performance and metabolic rate processes. The acute thermal optimum for dark respiration decreased, along with the maximal performance for gross photosynthetic and calcification rates. Gross photosynthetic and calcification rates normalized to a reference temperature (26.8°C) decreased along the gradient. Lastly, percent cover of P. acuta colonies decreased by nearly two orders of magnitude along the nutrient gradient. These findings illustrate that nutrient and sediment loading affect multiple levels of coral functionality. Understanding how local-scale anthropogenic stressors influence the responses of corals to temperature can inform coral reef management, particularly in relation to the mediation of land-based inputs into coastal coral reef ecosystems.}, }
@article {pmid32943557, year = {2020}, author = {DeAngelis, KM and Pold, G}, title = {Genome Sequences of Frankineae sp. Strain MT45 and Jatrophihabitans sp. Strain GAS493, Two Actinobacteria Isolated from Forest Soil.}, journal = {Microbiology resource announcements}, volume = {9}, number = {38}, pages = {}, pmid = {32943557}, issn = {2576-098X}, abstract = {Frankiaceae are bacterial endosymbionts that are also found free-living in soil. Here, we present the genome sequences of two novel bacterial members of the order Frankiales, class Actinobacteria, isolated from temperate terrestrial forest soils. The genomes for MT45 and GAS493 indicate a genetic capacity for carbohydrate degradation but not nitrogen fixation.}, }
@article {pmid32937243, year = {2020}, author = {Shin, PT and Baptista, RP and O'Neill, CM and Wallis, C and Reaves, BJ and Wolstenholme, AJ}, title = {Comparative sequences of the Wolbachia genomes of drug-sensitive and resistant isolates of Dirofilaria immitis.}, journal = {Veterinary parasitology}, volume = {286}, number = {}, pages = {109225}, pmid = {32937243}, issn = {1873-2550}, support = {R01 AI103140/AI/NIAID NIH HHS/United States ; R21 AI125899/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Dirofilaria immitis/*drug effects/microbiology ; *Drug Resistance ; *Genetic Variation ; *Genome, Bacterial ; Lactones/*pharmacology ; Macrocyclic Compounds/pharmacology ; Wolbachia/*genetics ; }, abstract = {The recent identification of isolates of D. immitis with confirmed resistance to the macrocyclic lactone preventatives presents an opportunity for comparative genomic studies using these isolates, and examining the genetic diversity within and between them. We studied the genomes of Wolbachia endosymbionts of five isolates of D. immitis maintained at the University of Georgia. Missouri and Georgia-2 are maintained as drug susceptible isolates, and JYD-27, Yazoo-2013 and Metairie-2014 are resistant to the macrocyclic lactone preventatives. We used whole genome amplification followed by Illumina-based sequencing from 8 to 12 individual microfilariae from each of the five isolates, obtaining a depth of coverage of approximately 40-75 fold for each. The Illumina sequences were used to create new genome assemblies for all the Wolbachia isolates studied. Comparisons of the Wolbachia sequences revealed more than 3000 sequence variations in each isolate. We identified 67 loci specific in resistant isolates but not in susceptible isolates, including 18 genes affected.Phylogenetic analysis suggested that the endosymbionts of the drug-susceptible isolates are more closely related to each other than to those from any of the resistant parasites. This level of variation in the Wolbachia endosymbionts of D. immitis isolates suggests a potential for selection for resistance against drugs targeting them.}, }
@article {pmid32927527, year = {2020}, author = {Kakumanu, ML and DeVries, ZC and Barbarin, AM and Santangelo, RG and Schal, C}, title = {Bed bugs shape the indoor microbial community composition of infested homes.}, journal = {The Science of the total environment}, volume = {743}, number = {}, pages = {140704}, doi = {10.1016/j.scitotenv.2020.140704}, pmid = {32927527}, issn = {1879-1026}, mesh = {Aged ; Animals ; *Bedbugs ; Hot Temperature ; Housing ; Humans ; *Microbiota ; Poverty ; }, abstract = {Indoor pests, and the allergens they produce, adversely affect human health. Surprisingly, however, their effects on indoor microbial communities have not been assessed. Bed bug (Cimex lectularius) infestations pose severe challenges in elderly and low-income housing. They void large amounts of liquid feces into the home environment, which might alter the indoor microbial community composition. In this study, using bed bug-infested and uninfested homes, we showed a strong impact of bed bug infestations on the indoor microbial diversity. Floor dust samples were collected from uninfested and bed bug-infested homes and their microbiomes were analyzed before and after heat interventions that eliminated bed bugs. The microbial communities of bed bug-infested homes were radically different from those of uninfested homes, and the bed bug endosymbiont Wolbachia was the major driver of this difference. After bed bugs were eliminated, the microbial community gradually shifted toward the community composition of uninfested homes, strongly implicating bed bugs in shaping the dust-associated environmental microbiome. Further studies are needed to understand the viability of these microbial communities and the potential risks that bed bug-associated microbes and their metabolites pose to human health.}, }
@article {pmid32924896, year = {2020}, author = {Gonçalves, WG and Fernandes, KM and Silva, APA and Gonçalves, DG and Fiaz, M and Serrão, JE}, title = {Ultrastructure of the Bacteriocytes in the Midgut of the Carpenter ant Camponotus rufipes: Endosymbiont Control by Autophagy.}, journal = {Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada}, volume = {26}, number = {6}, pages = {1236-1244}, doi = {10.1017/S1431927620024484}, pmid = {32924896}, issn = {1435-8115}, mesh = {Animals ; *Ants ; Autophagy ; Bacteria ; Humans ; Symbiosis ; }, abstract = {The carpenter ant Camponotus rufipes has intracellular bacteria in bacteriocytes scattered in the midgut epithelium, which have different amounts of endosymbionts, according to the developmental stages. However, there are no detailed data about the midgut cells in adult workers. The present work aimed to evaluate the morphology and cellular events that coordinate the abundance of endosymbionts in the midgut cells in C. rufipes workers. The midgut epithelium has digestive cells, bacteriocytes, and cells with intermediate morphology. The latter is similar to bacteriocytes, due to the abundance of endosymbionts, and similar to digestive cells, due to their microvilli. The digestive and intermediate cells are rich in autophagosomes and autolysosomes, both with bacteria debris in the lumen. These findings suggest that midgut cells of C. rufipes control the endosymbiont level by the autophagy pathway.}, }
@article {pmid32908591, year = {2020}, author = {Rossbacher, S and Vorburger, C}, title = {Prior adaptation of parasitoids improves biological control of symbiont-protected pests.}, journal = {Evolutionary applications}, volume = {13}, number = {8}, pages = {1868-1876}, pmid = {32908591}, issn = {1752-4571}, abstract = {There is increasing demand for sustainable pest management to reduce harmful effects of pesticides on the environment and human health. For pest aphids, biological control with parasitoid wasps provides a welcome alternative, particularly in greenhouses. However, aphids are frequently infected with the heritable bacterial endosymbiont Hamiltonella defensa, which increases resistance to parasitoids and thereby hampers biological control. Using the black bean aphid (Aphis fabae) and its main parasitoid Lysiphlebus fabarum, we tested whether prior adaptation of parasitoids can improve the control of symbiont-protected pests. We had parasitoid lines adapted to two different strains of H. defensa by experimental evolution, as well as parasitoids evolved on H. defensa-free aphids. We compared their ability to control caged aphid populations comprising 60% unprotected and 40% H. defensa-protected aphids, with both H. defensa strains present in the populations. Parasitoids that were not adapted to H. defensa had virtually no effect on aphid population dynamics compared to parasitoid-free controls, but one of the adapted lines and a mixture of both adapted lines controlled aphids successfully, strongly benefitting plant growth. Selection by parasitoids altered aphid population composition in a very specific manner. Aphid populations became dominated by H. defensa-protected aphids in the presence of parasitoids, and each adapted parasitoid line selected for the H. defensa strain it was not adapted to. This study shows, for the first time, that prior adaptation of parasitoids improves biological control of symbiont-protected pests, but the high specificity of parasitoid counter-resistance may represent a challenge for its implementation.}, }
@article {pmid32906741, year = {2020}, author = {Jain, SS and Afiq-Rosli, L and Feldman, B and Levy, O and Phua, JW and Wainwright, BJ and Huang, D}, title = {Homogenization of Endosymbiont Communities Hosted by Equatorial Corals during the 2016 Mass Bleaching Event.}, journal = {Microorganisms}, volume = {8}, number = {9}, pages = {}, pmid = {32906741}, issn = {2076-2607}, abstract = {Thermal stress drives the bleaching of reef corals, during which the endosymbiotic relationship between Symbiodiniaceae microalgae and the host breaks down. The endosymbiont communities are known to shift in response to environmental disturbances, but how they respond within and between colonies during and following bleaching events remains unclear. In 2016, a major global-scale bleaching event hit countless tropical reefs. Here, we investigate the relative abundances of Cladocopium LaJeunesse &amp; H.J.Jeong, 2018 and Durusdinium LaJeunesse, 2018 within and among Pachyseris speciosa colonies in equatorial Singapore that are known to host both these Symbiodiniaceae clades. Bleached and unbleached tissues from bleaching colonies, as well as healthy colonies, during and following the bleaching event were sampled and analyzed for comparison. The nuclear ribosomal internal transcribed spacer (ITS) regions were separately amplified and quantified using a SYBR Green-based quantitative polymerase chain reaction (qPCR) method and Illumina high-throughput sequencing. We found Cladocopium to be highly abundant relative to Durusdinium. The relative abundance of Durusdinium, known to be thermally tolerant, was highest in post-bleaching healthy colonies, while bleached and unbleached tissues from bleaching colonies as well as tissue from healthy colonies during the event had depressed proportions of Durusdinium. Given the importance of Durusdinium for thermal tolerance and stress response, it is surprising that bleached tissue showed limited change over healthy tissue during the bleaching event. Moreover, colonies were invariably dominated by Cladocopium during bleaching, but a minority of colonies were Durusdinium-dominant during non-bleaching times. The detailed characterization of Symbiodiniaceae in specific colonies during stress and recovery will provide insights into this crucial symbiosis, with implications for their responses during major bleaching events.}, }
@article {pmid32904796, year = {2020}, author = {Ciuca, L and Vismarra, A and Lebon, W and Beugnet, F and Morchon, R and Rinaldi, L and Cringoli, G and Kramer, L and Genchi, M}, title = {New insights into the biology, diagnosis and immune response to Dirofilaria repens in the canine host.}, journal = {Veterinary parasitology: X}, volume = {4}, number = {}, pages = {100029}, pmid = {32904796}, issn = {2590-1389}, abstract = {Dogs are the primary host for Dirofilaria repens, therefore it is mandatory to accurately diagnose the canine infection and to expand our current knowledge on parasite biology and the immune response of the infected host for a better prevention.Thus, the aim of the present study was to provide new insights from experimental infections of dogs with D. repens, focusing on the evaluation of: 1) the pre-patent period and 2) the antibody response against D. repens somatic antigens and against the Wolbachia endosymbiont. Briefly, on Day 0, twenty purpose-bred Beagle dogs were experimentally infected with 50 infective larvae (L3) of D. repens. Starting from Day 58 until the last day of the study (Day 281), blood samples were collected on a monthly basis for detection of antibodies against D. repens (Dr) and recombinant Wolbachia surface protein (rWSP) by non-commercial IgG-ELISAs. Additional samples were collected on Days 220, 245 and 281 for the detection of microfilariae (mff) using the modified Knott's test and biomolecular analysis, following two PCR protocols: Gioia et al. (2010; protocol A) and Rishniw et al. (2006- protocol B). The results were analysed by univariate statistical analyses using 2 × 2 contingency tables and K Cohen was calculated to assess the agreement among all the diagnostic techniques. Overall, the outcome of the study revealed that out of the 20 dogs experimentally infected with D. repens, 16 (80 %) were microfilaraemic, 17 (85 %) were positive at DNA detection in the blood, 18 (90 %) had D. repens antibodies and 16 (80 %) had Wolbachia antibodies on the last day of the study. The overall k agreement between Knott's and PCR protocol B was 0.442 (P = 0.0001) and increased throughout the study, reaching 0.828 (P = 0.0001) on Day 281. To the authors knowledge, this is only the second study reporting antibody response to D. repens somatic antigen in experimentally infected dogs. ELISA results showed that an antibody response develops before the onset of patency, and steadily increases with time. Results would suggest that the development of an immunological response to infection could lead to application in epidemiological studies, risk assessment and as an aid in the diagnostic approach in dogs, in particular for early infections without mff.}, }
@article {pmid32899580, year = {2020}, author = {Barraza-Guerrero, SI and Meza-Herrera, CA and García-De la Peña, C and González-Álvarez, VH and Vaca-Paniagua, F and Díaz-Velásquez, CE and Sánchez-Tortosa, F and Ávila-Rodríguez, V and Valenzuela-Núñez, LM and Herrera-Salazar, JC}, title = {General Microbiota of the Soft Tick Ornithodoros turicata Parasitizing the Bolson Tortoise (Gopherus flavomarginatus) in the Mapimi Biosphere Reserve, Mexico.}, journal = {Biology}, volume = {9}, number = {9}, pages = {}, pmid = {32899580}, issn = {2079-7737}, abstract = {The general bacterial microbiota of the soft tick Ornithodoros turicata found on Bolson tortoises (Gopherus flavomarginatus) were analyzed using next generation sequencing. The main aims of the study were to establish the relative abundance of bacterial taxa in the tick, and to document the presence of potentially pathogenic species for this tortoise, other animals, and humans. The study was carried-out in the Mapimi Biosphere Reserve in the northern-arid part of Mexico. Bolson tortoises (n = 45) were inspected for the presence of soft ticks, from which 11 tortoises (24.4%) had ticks in low loads (1-3 ticks per individual). Tick pools (five adult ticks each) were analyzed through 16S rRNA V3-V4 region amplification in a MiSeq Illumina, using EzBioCloud as a taxonomical reference. The operational taxonomic units (OTUs) revealed 28 phyla, 84 classes, 165 orders, 342 families, 1013 genera, and 1326 species. The high number of taxa registered for O. turicata may be the result of the variety of hosts that this tick parasitizes as they live inside G. flavomarginatus burrows. While the most abundant phyla were Proteobacteria, Actinobacteria, and Firmicutes, the most abundant species were two endosymbionts of ticks (Midichloria-like and Coxiella-like). Two bacteria documented as pathogenic to Gopherus spp. were registered (Mycoplasma spp. and Pasteurella testudinis). The bovine and ovine tick-borne pathogens A. marginale and A. ovis, respectively, were recorded, as well as the zoonotic bacteria A. phagocytophilum,Coxiella burnetii, and Neoehrlichia sp. Tortoises parasitized with O. turicata did not show evident signs of disease, which could indicate a possible ecological role as a reservoir that has yet to be demonstrated. In fact, the defense mechanisms of this tortoise against the microorganisms transmitted by ticks during their feeding process are still unknown. Future studies on soft ticks should expand our knowledge about what components of the microbiota are notable across multiple host-microbe dynamics. Likewise, studies are required to better understand the host competence of this tortoise, considered the largest terrestrial reptile in North America distributed throughout the Chihuahuan Desert since the late Pleistocene.}, }
@article {pmid32894786, year = {2020}, author = {Lenhart, PA and White, JA}, title = {Endosymbionts facilitate rapid evolution in a polyphagous herbivore.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {10}, pages = {1507-1511}, doi = {10.1111/jeb.13697}, pmid = {32894786}, issn = {1420-9101}, mesh = {Animals ; Aphids/*genetics/microbiology ; *Biological Evolution ; Gammaproteobacteria/*physiology ; *Herbivory ; Robinia ; *Selection, Genetic ; Symbiosis ; Vicia faba ; }, abstract = {Maternally transmitted bacterial symbionts can be important mediators of the interactions between insect herbivores and their foodplants. These symbionts are often facultative (present in some host individuals but not others) and can have large effects on their host's phenotype, thus giving rise to heritable variation upon which selection can act. In the cowpea aphid (Aphis craccivora), it has been established that the facultative endosymbiont Arsenophonus improves aphid performance on black locust trees (Robinia pseudoacacia) but not on fava (Vicia faba). Here, we tested whether this fitness differential translated into contemporaneous evolution of aphid populations associated with the different plants. In a laboratory study lasting 16 weeks, we found that the frequency of Arsenophonus-infected individuals significantly increased over time for aphid populations on black locust but declined for aphid populations on fava. By the end of the experiment, Arsenophonus infection was >3× more common on black locust than fava, which is comparable to previously described infection frequencies in natural field populations. Our results clearly demonstrate that aphid populations with mixed facultative symbiont infection status can rapidly evolve in response to the selective environments imposed by different host plants. This selection differential may be a sufficient explanation for the global association between Arsenophonus-infected cowpea aphids and black locust trees, without invoking additional assortative mechanisms. Because the aphid and plant originate from different parts of the world, we further hypothesize that Arsenophonus infection may have acted as a preadaptation that has promoted functional specialization of infected aphids on a novel host plant.}, }
@article {pmid32878185, year = {2020}, author = {Karakaidos, P and Rampias, T}, title = {Mitonuclear Interactions in the Maintenance of Mitochondrial Integrity.}, journal = {Life (Basel, Switzerland)}, volume = {10}, number = {9}, pages = {}, pmid = {32878185}, issn = {2075-1729}, abstract = {In eukaryotic cells, mitochondria originated in an α-proteobacterial endosymbiont. Although these organelles harbor their own genome, the large majority of genes, originally encoded in the endosymbiont, were either lost or transferred to the nucleus. As a consequence, mitochondria have become semi-autonomous and most of their processes require the import of nuclear-encoded components to be functional. Therefore, the mitochondrial-specific translation has evolved to be coordinated by mitonuclear interactions to respond to the energetic demands of the cell, acquiring unique and mosaic features. However, mitochondrial-DNA-encoded genes are essential for the assembly of the respiratory chain complexes. Impaired mitochondrial function due to oxidative damage and mutations has been associated with numerous human pathologies, the aging process, and cancer. In this review, we highlight the unique features of mitochondrial protein synthesis and provide a comprehensive insight into the mitonuclear crosstalk and its co-evolution, as well as the vulnerabilities of the animal mitochondrial genome.}, }
@article {pmid32876380, year = {2021}, author = {Shi, T and Niu, G and Kvitt, H and Zheng, X and Qin, Q and Sun, D and Ji, Z and Tchernov, D}, title = {Untangling ITS2 genotypes of algal symbionts in zooxanthellate corals.}, journal = {Molecular ecology resources}, volume = {21}, number = {1}, pages = {137-152}, doi = {10.1111/1755-0998.13250}, pmid = {32876380}, issn = {1755-0998}, mesh = {Animals ; *Anthozoa/microbiology ; DNA, Ribosomal Spacer/*genetics ; Databases, Genetic ; *Dinoflagellida/genetics ; Genotype ; Phylogeny ; RNA, Ribosomal, 28S/genetics ; RNA, Ribosomal, 5.8S/genetics ; }, abstract = {Collectively called zooxanthellae, photosynthetic dinoflagellates in the family Symbiodiniaceae are typical endosymbionts that unequivocally mediate coral responses to environmental changes. Symbiodiniaceae are genetically diverse, encompassing at least nine phylogenetically distinct genera (clades A-I). The ribosomal internal transcribed spacer 2 (ITS2) region is commonly utilized for determining Symbiodiniaceae diversity within clades. However, ITS2 is often inadvertently interpreted together with the tailing part of the ribosomal RNA genes (5.8S and 28S or equivalent), leading to unresolved taxonomy and equivocal annotations. To overcome this hurdle, we mined in GenBank and expert reference databases for ITS2 sequences of Symbiodiniaceae having explicit boundaries with adjacent rRNAs. We profiled a Hidden Markov Model of the ITS2-proximal 5.8S-28S rRNA interaction, which was shown to facilitate the delimitation of Symbiodiniaceae ITS2 from GenBank, while considerably reducing sequence ambiguity and redundancy in reference databases. The delineation of ITS2 sequences unveiled intra-clade sequence diversity and inter-clade secondary structure conservation. We compiled the clean data into a non-redundant database that archives the largest number of Symbiodiniaceae ITS2 sequences known to date with definite genotype/subclade representations and well-defined secondary structures. This database provides a fundamental reference catalog for consistent and precise genotyping of Symbiodiniaceae and a tool for automated annotation of user-supplied sequences.}, }
@article {pmid32866324, year = {2021}, author = {Lamin, H and Alami, S and Bouhnik, O and Bennis, M and Benkritly, S and Abdelmoumen, H and Bedmar, EJ and Missbah-El Idrissi, M}, title = {Identification of the endosymbionts from Sulla spinosissima growing in a lead mine tailings in Eastern Morocco as Mesorhizobium camelthorni sv. aridi.}, journal = {Journal of applied microbiology}, volume = {130}, number = {3}, pages = {948-959}, doi = {10.1111/jam.14834}, pmid = {32866324}, issn = {1365-2672}, mesh = {Bacterial Proteins/genetics ; Fabaceae/*microbiology ; Genes, Essential/genetics ; Host Specificity ; Lead/*metabolism ; Mesorhizobium/classification/*physiology ; *Mining ; Morocco ; Phylogeny ; Plant Root Nodulation/genetics ; RNA, Ribosomal, 16S/genetics ; Root Nodules, Plant/microbiology ; Soil Microbiology ; *Symbiosis/genetics ; }, abstract = {AIMS: To identify the bacteria nodulating Sulla spinosissima growing profusely in a lead and zinc mine tailings in Eastern Morocco.<br><br>METHODS AND RESULTS: In all, 32 rhizobial cultures, isolated from root nodules of S. spinosissima growing in soils of the mining site, were tolerant to different heavy metals. The ERIC-polymerase chain reaction (PCR) fingerprinting analysis clustered the isolates into seven different groups, and the analysis of the 16S rRNA sequences of four selected representative strains, showed they were related to different species of the genus Mesorhizobium. The atpD, glnII and recA housekeeping genes analysis confirmed the affiliation of the four representative strains to Mesorhizobium camelthorni CCNWXJ40-4[T] , with similarity percentages varying from 96&#xb7;30 to 98&#xb7;30%. The sequences of the nifH gene had 97&#xb7;33-97&#xb7;78% similarities with that of M. camelthorni CCNWXJ40-4[T] ; however, the nodC phylogeny of the four strains diverged from the type and other reference strains of M. camelthorni and formed a separated cluster. The four strains nodulate also Astragalus gombiformis and A. armatus but did not nodulate A. boeticus, Vachellia gummifera, Prosopis chilensis, Cicer arietinum, Lens culinaris, Medicago truncatula, Lupinus luteus or Phaseolus vulgaris.<br><br>CONCLUSIONS: Based on similarities of the nodC symbiotic gene and differences in the host range, the strains isolated from S. spinosissima growing in soils of the Sidi Boubker mining site may form a different symbiovar within Mesorhizobium for which the name aridi is proposed.<br><br>In this work, we show that strains of M. camelthorni species nodulating S. spinosissima in the arid area of Eastern Morocco constitute a distinct phylogenetic clade of nodulation genes; we named symbiovar aridi, which encompasses also mesorhizobia from other Mediterranean desert legumes.}, }
@article {pmid32866142, year = {2020}, author = {Oundo, JW and Villinger, J and Jeneby, M and Ong'amo, G and Otiende, MY and Makhulu, EE and Musa, AA and Ouso, DO and Wambua, L}, title = {Pathogens, endosymbionts, and blood-meal sources of host-seeking ticks in the fast-changing Maasai Mara wildlife ecosystem.}, journal = {PloS one}, volume = {15}, number = {8}, pages = {e0228366}, pmid = {32866142}, issn = {1932-6203}, mesh = {Animals ; Animals, Wild ; Babesia ; Cattle ; Cattle Diseases/microbiology ; Coxiella ; Ecosystem ; Ehrlichia ; Humans ; Ixodidae/microbiology ; Kenya/epidemiology ; Rhipicephalus ; Rickettsia ; Sheep ; Theileria ; Tick Infestations/*epidemiology/veterinary ; Tick-Borne Diseases/*epidemiology/microbiology ; Ticks/parasitology/*pathogenicity ; Zoonoses ; }, abstract = {The role of questing ticks in the epidemiology of tick-borne diseases in Kenya's Maasai Mara National Reserve (MMNR), an ecosystem with intensified human-wildlife-livestock interactions, remains poorly understood. We surveyed the diversity of questing ticks, their blood-meal hosts, and tick-borne pathogens to understand potential effects on human and livestock health. By flagging and hand-picking from vegetation in 25 localities, we collected 1,465 host-seeking ticks, mostly Rhipicephalus and Amblyomma species identified by morphology and molecular analysis. We used PCR with high-resolution melting (HRM) analysis and sequencing to identify Anaplasma, Babesia, Coxiella, Ehrlichia, Rickettsia, and Theileria pathogens and blood-meal remnants in 231 tick pools. We detected blood-meals from humans, wildebeest, and African buffalo in Rh. appendiculatus, goat in Rh. evertsi, sheep in Am. gemma, and cattle in Am. variegatum. Rickettsia africae was detected in Am. gemma (MIR = 3.10) that had fed on sheep and in Am. variegatum (MIR = 250) that had fed on cattle. We found Rickettsia spp. in Am. gemma (MIR = 9.29) and Rh. evertsi (MIR = 200), Anaplasma ovis in Rh. appendiculatus (MIR = 0.89) and Rh. evertsi (MIR = 200), Anaplasma bovis in Rh. appendiculatus (MIR = 0.89), and Theileria parva in Rh. appendiculatus (MIR = 24). No Babesia, Ehrlichia, or Coxiella pathogens were detected. Unexpectedly, species-specific Coxiella sp. endosymbionts were detected in all tick genera (174/231 pools), which may affect tick physiology and vector competence. These findings show that ticks from the MMNR are infected with zoonotic R. africae and unclassified Rickettsia spp., demonstrating risk of African tick-bite fever and other spotted-fever group rickettsioses to locals and visitors. The protozoan pathogens identified may also pose risk to livestock production. The diverse vertebrate blood-meals of questing ticks in this ecosystem including humans, wildlife, and domestic animals, may amplify transmission of tick-borne zoonoses and livestock diseases.}, }
@article {pmid32859597, year = {2020}, author = {Li, L and Wang, M and Li, L and Du, Z and Sun, Y and Wang, X and Zhang, X and Li, C}, title = {Endosymbionts of Metazoans Dwelling in the PACManus Hydrothermal Vent: Diversity and Potential Adaptive Features Revealed by Genome Analysis.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {21}, pages = {}, pmid = {32859597}, issn = {1098-5336}, mesh = {*Adaptation, Biological ; Animals ; Bacteria/genetics ; *Bacterial Physiological Phenomena ; Gastropoda/*microbiology ; Genome, Bacterial ; Hydrothermal Vents/*microbiology ; Microbiota ; Mytilidae/*microbiology ; Pacific Ocean ; Papua New Guinea ; Polychaeta/*microbiology ; *Symbiosis ; }, abstract = {Deep-sea hydrothermal vent communities are dominated by invertebrates, namely, bathymodiolin mussels, siboglinid tubeworms, and provannid snails. Symbiosis is considered key to successful colonization by these sedentary species in such extreme environments. In the PACManus vent fields, snails, tubeworms, and mussels each colonized a niche with distinct geochemical characteristics. To better understand the metabolic potentials and genomic features contributing to host-environment adaptation, we compared the genomes of the symbionts of Bathymodiolus manusensis, Arcovestia ivanovi, and Alviniconcha boucheti sampled at PACManus, and we discuss their environmentally adaptive features. We found that B. manusensis and A. ivanovi are colonized by Gammaproteobacteria from distinct clades, whereas endosymbionts of B. manusensis feature high intraspecific heterogeneity with differing metabolic potentials. A. boucheti harbored three novel Epsilonproteobacteria symbionts, suggesting potential species-level diversity of snail symbionts. Genome comparisons revealed that the relative abundance of gene families related to low-pH homeostasis, metal resistance, oxidative stress resistance, environmental sensing/responses, and chemotaxis and motility was the highest in A. ivanovi's symbiont, followed by symbionts of the vent-mouth-dwelling snail A. boucheti, and was relatively low in the symbiont of the vent-periphery-dwelling mussel B. manusensis, which is consistent with their environmental adaptations and host-symbiont interactions. Gene families classified as encoding host interaction/attachment, virulence factors/toxins, and eukaryotic-like proteins were most abundant in symbionts of mussels and least abundant in those of snails, indicating that these symbionts may differ in their host colonization strategies. Comparison of Epsilonproteobacteria symbionts to nonsymbionts demonstrated that the expanded gene families in symbionts were related to vitamin B12 synthesis, toxin-antitoxin systems, methylation, and lipopolysaccharide biosynthesis, suggesting that these are vital to symbiont establishment and development in EpsilonproteobacteriaIMPORTANCE Deep-sea hydrothermal vents are dominated by several invertebrate species. The establishment of symbiosis has long been thought to be the key to successful colonization by these sedentary species in such harsh environments. However, the relationships between symbiotic bacteria and their hosts and their role in environmental adaptations generally remain unclear. In this paper, we show that the distribution of three host species showed characteristic niche partitioning in the Manus Basin, giving us the opportunity to understand how they adapt to their particular habitats. This study also revealed three novel genomes of symbionts from the snails of A. boucheti Combined with a data set on other ectosymbiont and free-living bacteria, genome comparisons for the snail endosymbionts pointed to several genetic traits that may have contributed to the lifestyle shift of Epsilonproteobacteria into the epithelial cells. These findings could increase our understanding of invertebrate-endosymbiont relationships in deep-sea ecosystems.}, }
@article {pmid32857636, year = {2020}, author = {Medini, H and Cohen, T and Mishmar, D}, title = {Mitochondria Are Fundamental for the Emergence of Metazoans: On Metabolism, Genomic Regulation, and the Birth of Complex Organisms.}, journal = {Annual review of genetics}, volume = {54}, number = {}, pages = {151-166}, doi = {10.1146/annurev-genet-021920-105545}, pmid = {32857636}, issn = {1545-2948}, mesh = {Animals ; Chromatin/genetics ; Embryonic Development/genetics ; Epigenesis, Genetic/genetics ; Genome/*genetics ; Humans ; Mitochondria/*genetics ; }, abstract = {Out of many intracellular bacteria, only the mitochondria and chloroplasts abandoned their independence billions of years ago and became endosymbionts within the host eukaryotic cell. Consequently, one cannot grow eukaryotic cells without their mitochondria, and the mitochondria cannot divide outside of the cell, thus reflecting interdependence. Here, we argue that such interdependence underlies the fundamental role of mitochondrial activities in the emergence of metazoans. Several lines of evidence support our hypothesis: (a) Differentiation and embryogenesis rely on mitochondrial function; (b) mitochondrial metabolites are primary precursors for epigenetic modifications (such as methyl and acetyl), which are critical for chromatin remodeling and gene expression, particularly during differentiation and embryogenesis; and (c) mitonuclear coregulation adapted to accommodate both housekeeping and tissue-dependent metabolic needs. We discuss the evolution of the unique mitochondrial genetic system, mitochondrial metabolites, mitonuclear coregulation, and their critical roles in the emergence of metazoans and in human disorders.}, }
@article {pmid32855244, year = {2020}, author = {Neupane, S and Bonilla, SI and Manalo, AM and Pelz-Stelinski, KS}, title = {Near-Complete Genome Sequences of a Wolbachia Strain Isolated from Diaphorina citri Kuwayama (Hemiptera: Liviidae).}, journal = {Microbiology resource announcements}, volume = {9}, number = {35}, pages = {}, pmid = {32855244}, issn = {2576-098X}, abstract = {Wolbachia strains are one of three endosymbionts associated with the insect vector of "Candidatus Liberibacter asiaticus," Diaphorina citri Kuwayama (Hemiptera: Liviidae). We report three near-complete genome sequences of samples of Wolbachia from D. citri (wDi), with sizes of 1,518,595, 1,542,468, and 1,538,523 bp.}, }
@article {pmid32854141, year = {2020}, author = {Altinli, M and Lequime, S and Atyame, C and Justy, F and Weill, M and Sicard, M}, title = {Wolbachia modulates prevalence and viral load of Culex pipiens densoviruses in natural populations.}, journal = {Molecular ecology}, volume = {29}, number = {20}, pages = {4000-4013}, doi = {10.1111/mec.15609}, pmid = {32854141}, issn = {1365-294X}, mesh = {Animals ; *Culex/genetics ; *Densovirus/genetics ; Phylogeny ; Prevalence ; Viral Load ; *Wolbachia/genetics ; }, abstract = {The inadequacy of standard mosquito control strategies calls for ecologically safe novel approaches, for example the use of biological agents such as the endosymbiotic α-proteobacteria Wolbachia or insect-specific viruses (ISVs). Understanding the ecological interactions between these "biocontrol endosymbionts" is thus a fundamental step. Wolbachia are transmitted vertically from mother to offspring and modify their hosts' phenotypes, including reproduction (e.g., cytoplasmic incompatibility) and survival (e.g., viral interference). In nature, Culex pipiens (sensu lato) mosquitoes are always found infected with genetically diverse Wolbachia called wPip that belong to five phylogenetic groups. In recent years, ISVs have also been discovered in these mosquito species, although their interactions with Wolbachia in nature are unknown. Here, we studied the interactions between a widely prevalent ISV, the Culex pipiens densovirus (CpDV, Densovirinae), and Wolbachia in northern Tunisian C. pipiens populations. We showed an influence of different Wolbachia groups on CpDV prevalence and a general positive correlation between Wolbachia and CpDV loads. By investigating the putative relationship between CpDV diversification and wPip groups in the different sites, we detected a signal linked to wPip groups in CpDV phylogeny in sites where all larvae were infected by the same wPip group. However, no such signal was detected where the wPip groups coexisted, suggesting CpDV horizontal transfer between hosts. Overall, our results provide good evidence for an ecological influence of Wolbachia on an ISV, CpDV, in natural populations and highlight the importance of integrating Wolbachia in our understanding of ISV ecology in nature.}, }
@article {pmid32849379, year = {2020}, author = {Lu, P and Sun, Q and Fu, P and Li, K and Liang, X and Xi, Z}, title = {Wolbachia Inhibits Binding of Dengue and Zika Viruses to Mosquito Cells.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1750}, pmid = {32849379}, issn = {1664-302X}, abstract = {As traditional approaches to the control of dengue and Zika are insufficient, significant efforts have been made to develop utilization of the endosymbiotic bacterium Wolbachia to reduce the ability of mosquitoes to transmit pathogens. Although Wolbachia is known to inhibit flaviviruses in mosquitoes, including dengue virus (DENV) and Zika virus (ZIKV), it remains unclear how the endosymbiont interferes with viral replication cycle. In this study, we have carried out viral binding assays to investigate the impact of the Wolbachia strain wAlbB on the attachment of DENV serotype 2 (DENV-2) and ZIKV to Aedes aegypti Aag-2 cells. RNA interference (RNAi) was used to silence a variety of putative mosquito receptors of DENV that were differentially regulated by wAlbB in Aag-2 cells, in order to identify host factors involved in the inhibition of viral binding. Our results showed that, in addition to suppression of viral replication, Wolbachia strongly inhibited binding of both DENV-2 and ZIKV to Aag-2 cells. Moreover, the expression of two putative mosquito DENV receptors - dystroglycan and tubulin - was downregulated by wAlbB, and their knock-down resulted in the inhibition of DENV-2 binding to Aag-2 cells. These results will aid in understanding the Wolbachia-DENV interactions in mosquito and the development of novel control strategies for mosquito-borne diseases.}, }
@article {pmid32848325, year = {2020}, author = {Elbir, H and Almathen, F and Elnahas, A}, title = {Low genetic diversity among Francisella-like endosymbionts within different genotypes of Hyalomma dromedarii ticks infesting camels in Saudi Arabia.}, journal = {Veterinary world}, volume = {13}, number = {7}, pages = {1462-1472}, pmid = {32848325}, issn = {0972-8988}, abstract = {BACKGROUND AND AIM: Hyalomma dromedarii ticks are vectors of disease agents and hosts of Francisella-like endosymbionts (FLEs). Knowledge about intraspecific genetic variation among H. dromedarii and its Francisella species is limited. The aims of this study were to investigate whether certain H. dromedarii genotypes are specialized in carrying specific Francisella species genotypes and scrutinize the population structure of H. dromedarii ticks in Saudi Arabia.<br><br>MATERIALS AND METHODS: We collected 151 H. dromedarii ticks from 33 camels from 13 locations in Saudi Arabia. The second internal transcribed spacer (ITS2), cytochrome c oxidase subunit-1(COI), and 16S rRNA genes were used for single- and multi-locus sequence typing and phylogenetic analyses. H. dromedarii-borne Francisella was screened using the tul4 gene and 16S rRNA Francisella-specific primers followed by amplicon Sanger sequencing.<br><br>RESULTS: Single-locus typing of ticks using ITS2, 16S rRNA, and COI genes yielded 1, 10, and 31 sequence types (ST), respectively, with pairwise sequence similarity of 100% for ITS2, 99.18-99.86% for COI, and 99.50-99.75% for 16S rRNA. COI sequence analysis indicated a lack of strict geographical structuration, as ST15 was found in both Saudi Arabia and Kenya. In contrast, multilocus sequence typing resolved 148 H. dromedarii ticks into 39 genotypes of ticks and three genotypes of FLEs. The ST2-FLE genotype was carried by the tick genotype ST35, while the ST1-FLE genotype and 41.89% of the ST3-FLE genotype were carried by the tick genotype ST32. Accordingly, there appeared to be no specialization of certain tick genotypes to harbor-specific FLE genotypes.<br><br>CONCLUSION: For the 1[st] time, we have provided an overview of the population structure of H. dromedarii ticks and FLE strains. We found a low level of genetic diversity among FLEs and non-specialized circulation of FLEs among H. dromedarii ticks.}, }
@article {pmid32841522, year = {2021}, author = {McGinley, LM and Willsey, MS and Kashlan, ON and Chen, KS and Hayes, JM and Bergin, IL and Mason, SN and Stebbins, AW and Kwentus, JF and Pacut, C and Kollmer, J and Sakowski, SA and Bell, CB and Chestek, CA and Murphy, GG and Patil, PG and Feldman, EL}, title = {Magnetic resonance imaging of human neural stem cells in rodent and primate brain.}, journal = {Stem cells translational medicine}, volume = {10}, number = {1}, pages = {83-97}, pmid = {32841522}, issn = {2157-6580}, support = {P30 CA046592/CA/NCI NIH HHS/United States ; T32 NS007222/NS/NINDS NIH HHS/United States ; R43 TR001202/TR/NCATS NIH HHS/United States ; R25 NS089450/NS/NINDS NIH HHS/United States ; P60 DK020572/DK/NIDDK NIH HHS/United States ; R01 AG052934/AG/NIA NIH HHS/United States ; U01 AG057562/AG/NIA NIH HHS/United States ; }, mesh = {Animals ; *Bacteria ; *Brain/diagnostic imaging ; Cell Tracking ; Contrast Media ; Humans ; *Magnetic Resonance Imaging ; *Magnetics ; Mice ; *Neural Stem Cells ; Primates ; Rodentia ; Stem Cell Transplantation ; }, abstract = {Stem cell transplantation therapies are currently under investigation for central nervous system disorders. Although preclinical models show benefit, clinical translation is somewhat limited by the absence of reliable noninvasive methods to confirm targeting and monitor transplanted cells in vivo. Here, we assess a novel magnetic resonance imaging (MRI) contrast agent derived from magnetotactic bacteria, magneto-endosymbionts (MEs), as a translatable methodology for in vivo tracking of stem cells after intracranial transplantation. We show that ME labeling provides robust MRI contrast without impairment of cell viability or other important therapeutic features. Labeled cells were visualized immediately post-transplantation and over time by serial MRI in nonhuman primate and mouse brain. Postmortem tissue analysis confirmed on-target grft location, and linear correlations were observed between MRI signal, cell engraftment, and tissue ME levels, suggesting that MEs may be useful for determining graft survival or rejection. Overall, these findings indicate that MEs are an effective tool for in vivo tracking and monitoring of cell transplantation therapies with potential relevance to many cellular therapy applications.}, }
@article {pmid32841233, year = {2020}, author = {Russell, SL and Pepper-Tunick, E and Svedberg, J and Byrne, A and Ruelas Castillo, J and Vollmers, C and Beinart, RA and Corbett-Detig, R}, title = {Horizontal transmission and recombination maintain forever young bacterial symbiont genomes.}, journal = {PLoS genetics}, volume = {16}, number = {8}, pages = {e1008935}, pmid = {32841233}, issn = {1553-7404}, support = {R25 GM058903/GM/NIGMS NIH HHS/United States ; R35 GM128932/GM/NIGMS NIH HHS/United States ; T32 HG008345/HG/NHGRI NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics/*pathogenicity ; Bivalvia/genetics/*microbiology ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genetic Variation ; *Genome, Bacterial ; *Recombination, Genetic ; Symbiosis/*genetics ; }, abstract = {Bacterial symbionts bring a wealth of functions to the associations they participate in, but by doing so, they endanger the genes and genomes underlying these abilities. When bacterial symbionts become obligately associated with their hosts, their genomes are thought to decay towards an organelle-like fate due to decreased homologous recombination and inefficient selection. However, numerous associations exist that counter these expectations, especially in marine environments, possibly due to ongoing horizontal gene flow. Despite extensive theoretical treatment, no empirical study thus far has connected these underlying population genetic processes with long-term evolutionary outcomes. By sampling marine chemosynthetic bacterial-bivalve endosymbioses that range from primarily vertical to strictly horizontal transmission, we tested this canonical theory. We found that transmission mode strongly predicts homologous recombination rates, and that exceedingly low recombination rates are associated with moderate genome degradation in the marine symbionts with nearly strict vertical transmission. Nonetheless, even the most degraded marine endosymbiont genomes are occasionally horizontally transmitted and are much larger than their terrestrial insect symbiont counterparts. Therefore, horizontal transmission and recombination enable efficient natural selection to maintain intermediate symbiont genome sizes and substantial functional genetic variation.}, }
@article {pmid32838795, year = {2020}, author = {Onyiche, TE and Răileanu, C and Tauchmann, O and Fischer, S and Vasić, A and Schäfer, M and Biu, AA and Ogo, NI and Thekisoe, O and Silaghi, C}, title = {Prevalence and molecular characterization of ticks and tick-borne pathogens of one-humped camels (Camelus dromedarius) in Nigeria.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {428}, pmid = {32838795}, issn = {1756-3305}, mesh = {Anaplasma/isolation &amp; purification ; Animals ; Babesia/isolation &amp; purification ; *Camelus/microbiology/parasitology ; Coxiella/isolation &amp; purification ; Humans ; *Ixodidae/microbiology/parasitology ; Nigeria/epidemiology ; Pathology, Molecular ; Prevalence ; Rickettsia/isolation &amp; purification ; Tick Infestations/*veterinary ; Tick-Borne Diseases/epidemiology/veterinary ; Zoonoses ; }, abstract = {BACKGROUND: Ticks are hematophagous arthropods responsible for maintenance and transmission of several pathogens of veterinary and medical importance. Current knowledge on species diversity and pathogens transmitted by ticks infesting camels in Nigeria is limited. Therefore, the aim of this study was to unravel the status of ticks and tick-borne pathogens of camels in Nigeria.<br><br>METHODS: Blood samples (n&#x2009;=&#x2009;176) and adult ticks (n&#x2009;=&#x2009;593) were collected from one-humped camels (Camelus dromedarius) of both sexes in three locations (Kano, Jigawa and Sokoto states) in north-western Nigeria and screened for the presence of Rickettsia spp., Babesia spp., Anaplasma marginale, Anaplasma spp. and Coxiella-like organisms using molecular techniques. All ticks were identified to species level using a combination of morphological and molecular methods.<br><br>RESULTS: Ticks comprised the three genera Hyalomma, Amblyomma and Rhipicephalus. Hyalomma dromedarii was the most frequently detected tick species (n&#x2009;=&#x2009;465; 78.4%) while Amblyomma variegatum (n&#x2009;=&#x2009;1; 0.2%) and Rhipicephalus evertsi evertsi (n&#x2009;=&#x2009;1; 0.2%) were less frequent. Other tick species included H. truncatum (n&#x2009;=&#x2009;87; 14.7%), H. rufipes (n&#x2009;=&#x2009;19; 3.2%), H. impeltatum (n&#x2009;=&#x2009;18; 3.0%) and H. impressum (n&#x2009;=&#x2009;2; 0.3%). The minimum infection rates of tick-borne pathogens in 231 tick pools included Rickettsia aeschlimannii (n&#x2009;=&#x2009;51; 8.6%); Babesia species, (n&#x2009;=&#x2009;4; 0.7%) comprising of B. occultans (n&#x2009;=&#x2009;2), B. caballi (n&#x2009;=&#x2009;1) and Babesia sp. (n&#x2009;=&#x2009;1); Coxiella burnetii (n&#x2009;=&#x2009;17; 2.9%); and endosymbionts in ticks (n&#x2009;=&#x2009;62; 10.5%). We detected DNA of "Candidatus Anaplasma camelli" in 40.3% of the blood samples of camels. Other tick-borne pathogens including Anaplasma marginale were not detected. Analysis of risk factors associated with both tick infestation and infection with Anaplasma spp. in the blood indicated that age and body condition scores of the camels were significant (P&#x2009;<&#x2009;0.05) risk factors while gender was not.<br><br>CONCLUSIONS: This study reports low to moderate prevalence rates of selected tick-borne pathogens associated with camels and their ticks in north-western Nigeria. The presence of zoonotic R. aeschlimannii emphasizes the need for a concerted tick control programme in Nigeria.}, }
@article {pmid32837530, year = {2021}, author = {Kumar, S and Gupta, S and Mohmad, A and Fular, A and Parthasarathi, BC and Chaubey, AK}, title = {Molecular tools-advances, opportunities and prospects for the control of parasites of veterinary importance.}, journal = {International journal of tropical insect science}, volume = {41}, number = {1}, pages = {33-42}, pmid = {32837530}, issn = {1742-7584}, abstract = {The recent advancement in genome sequencing facilities, proteomics, transcriptomics, and metabolomics of eukaryotes have opened door for employment of molecular diagnostic techniques for early detection of parasites and determining target molecules for formulating control strategies. It further leads to the introduction of several purified vaccines in the field of veterinary parasitology. Earlier, the conventional diagnostic methods was entirely based upon morphological taxonomy for diagnosis of parasites but nowadays improved molecular techniques help in phylogenetic study and open an another area of molecular taxonomy of parasites with high precision. Control measures based upon targeting endosymbionts in parasites like Dirofilaria immitis is also under exploration in veterinary parasitology. Metagenomics have added an inside story of parasites bionomics which have created havoc in human and animals population since centuries. Omics era is playing a key role in opening the new approaches on parasite biology. Various newer generations of safer vaccines like edible vaccines and subunit vaccines and diagnostic techniques based upon purified immunologically active epitopes have become commercially available against the parasites (helminths, protozoa and arthropod borne diseases). Nowadays, a transgenic and gene knock out studies using RNA interference and CRISPR are also helping in understanding the functions of genes and screening of target genes, which are not available before the advent of molecular tools. Molecular techniques had paramount impact on increasing the sensitivity of diagnostic tools, epidemiological studies and more importantly in controlling these diseases. This review is about the advancements in veterinary parasitology and their impact on the control of these pathogens.}, }
@article {pmid32831146, year = {2020}, author = {Wada, N and Yuasa, H and Kajitani, R and Gotoh, Y and Ogura, Y and Yoshimura, D and Toyoda, A and Tang, SL and Higashimura, Y and Sweatman, H and Forsman, Z and Bronstein, O and Eyal, G and Thongtham, N and Itoh, T and Hayashi, T and Yasuda, N}, title = {A ubiquitous subcuticular bacterial symbiont of a coral predator, the crown-of-thorns starfish, in the Indo-Pacific.}, journal = {Microbiome}, volume = {8}, number = {1}, pages = {123}, pmid = {32831146}, issn = {2049-2618}, mesh = {Animals ; *Anthozoa ; Bacteria/genetics/*isolation &amp; purification ; Coral Reefs ; Indian Ocean ; Male ; Pacific Ocean ; Phylogeny ; *Predatory Behavior ; RNA, Ribosomal, 16S/genetics ; Starfish/genetics/*microbiology/*physiology ; *Symbiosis ; }, abstract = {BACKGROUND: Population outbreaks of the crown-of-thorns starfish (Acanthaster planci sensu lato; COTS), a primary predator of reef-building corals in the Indo-Pacific Ocean, are a major threat to coral reefs. While biological and ecological knowledge of COTS has been accumulating since the 1960s, little is known about its associated bacteria. The aim of this study was to provide fundamental information on the dominant COTS-associated bacteria through a multifaceted molecular approach.<br><br>METHODS: A total of 205 COTS individuals from 17 locations throughout the Indo-Pacific Ocean were examined for the presence of COTS-associated bacteria. We conducted 16S rRNA metabarcoding of COTS to determine the bacterial profiles of different parts of the body and generated a full-length 16S rRNA gene sequence from a single dominant bacterium, which we designated COTS27. We performed phylogenetic analysis to determine the taxonomy, screening of COTS27 across the Indo-Pacific, FISH to visualize it within the COTS tissues, and reconstruction of the bacterial genome from the hologenome sequence data.<br><br>RESULTS: We discovered that a single bacterium exists at high densities in the subcuticular space in COTS forming a biofilm-like structure between the cuticle and the epidermis. COTS27 belongs to a clade that presumably represents a distinct order (so-called marine spirochetes) in the phylum Spirochaetes and is universally present in COTS throughout the Indo-Pacific Ocean. The reconstructed genome of COTS27 includes some genetic traits that are probably linked to adaptation to marine environments and evolution as an extracellular endosymbiont in subcuticular spaces.<br><br>CONCLUSIONS: COTS27 can be found in three allopatric COTS species, ranging from the northern Red Sea to the Pacific, implying that the symbiotic relationship arose before the speciation events (approximately 2 million years ago). The universal association of COTS27 with COTS and nearly mono-specific association at least with the Indo-Pacific COTS provides a useful model system for studying symbiont-host interactions in marine invertebrates and may have applications for coral reef conservation. Video Abstract.}, }
@article {pmid32816285, year = {2021}, author = {Militello, G and Bich, L and Moreno, A}, title = {Functional Integration and Individuality in Prokaryotic Collective Organisations.}, journal = {Acta biotheoretica}, volume = {69}, number = {3}, pages = {391-415}, pmid = {32816285}, issn = {1572-8358}, mesh = {*Biological Evolution ; Humans ; *Prokaryotic Cells ; Symbiosis ; }, abstract = {Both physiological and evolutionary criteria of biological individuality are underpinned by the idea that an individual is a functionally integrated whole. However, a precise account of functional integration has not been provided so far, and current notions are not developed in the details, especially in the case of composite systems. To address this issue, this paper focuses on the organisational dimension of two representative associations of prokaryotes: biofilms and the endosymbiosis between prokaryotes. Some critical voices have been raised against the thesis that biofilms are biological individuals. Nevertheless, it has not been investigated which structural and functional obstacles may prevent them from being fully integrated physiological or evolutionary units. By contrast, the endosymbiotic association of different species of prokaryotes has the potential for achieving a different type of physiological integration based on a common boundary and interlocked functions. This type of association had made it possible, under specific conditions, to evolve endosymbionts into fully integrated organelles. This paper therefore has three aims: first, to analyse the organisational conditions and the physiological mechanisms that enable integration in prokaryotic associations; second, to discuss the organisational differences between biofilms and prokaryotic endosymbiosis and the types of integration they achieve; finally, to provide a more precise account of functional integration based on these case studies.}, }
@article {pmid32813725, year = {2020}, author = {Shropshire, JD and Kalra, M and Bordenstein, SR}, title = {Evolution-guided mutagenesis of the cytoplasmic incompatibility proteins: Identifying CifA's complex functional repertoire and new essential regions in CifB.}, journal = {PLoS pathogens}, volume = {16}, number = {8}, pages = {e1008794}, pmid = {32813725}, issn = {1553-7374}, support = {R01 AI132581/AI/NIAID NIH HHS/United States ; R01 AI143725/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Animals, Genetically Modified/microbiology/physiology ; Bacterial Proteins/genetics/*metabolism ; *Biological Evolution ; Cytoplasm/*metabolism/microbiology ; Drosophila melanogaster/*microbiology/physiology ; Female ; Gram-Negative Bacterial Infections/*metabolism/microbiology/pathology ; Male ; *Mutation ; Wolbachia/*physiology ; }, abstract = {Wolbachia are the world's most common, maternally-inherited, arthropod endosymbionts. Their worldwide distribution is due, in part, to a selfish drive system termed cytoplasmic incompatibility (CI) that confers a relative fitness advantage to females that transmit Wolbachia to their offspring. CI results in embryonic death when infected males mate with uninfected females but not infected females. Under the Two-by-One genetic model of CI, males expressing the two phage WO proteins CifA and CifB cause CI, and females expressing CifA rescue CI. While each protein is predicted to harbor three functional domains, there is no knowledge on how sites across these Cif domains, rather than in any one particular domain, contribute to CI and rescue. Here, we use evolution-guided, substitution mutagenesis of conserved amino acids across the Cif proteins, coupled with transgenic expression in uninfected Drosophila melanogaster, to determine the functional impacts of conserved residues evolving mostly under purifying selection. We report that amino acids in CifA's N-terminal unannotated region and annotated catalase-related domain are important for both complete CI and rescue, whereas C-terminal residues in CifA's putative domain of unknown function are solely important for CI. Moreover, conserved CifB amino acids in the predicted nucleases, peptidase, and unannotated regions are essential for CI. Taken together, these findings indicate that (i) all CifA amino acids determined to be crucial in rescue are correspondingly crucial in CI, (ii) an additional set of CifA amino acids are uniquely important in CI, and (iii) CifB amino acids across the protein, rather than in one particular domain, are all crucial for CI. We discuss how these findings advance an expanded view of Cif protein evolution and function, inform the mechanistic and biochemical bases of Cif-induced CI/rescue, and continue to substantiate the Two-by-One genetic model of CI.}, }
@article {pmid32809186, year = {2020}, author = {Cotes-Perdomo, AP and Oviedo, &#xc1; and Castro, LR}, title = {Molecular detection of pathogens in ticks associated with domestic animals from the Colombian Caribbean region.}, journal = {Experimental &amp; applied acarology}, volume = {82}, number = {1}, pages = {137-150}, doi = {10.1007/s10493-020-00531-0}, pmid = {32809186}, issn = {1572-9702}, mesh = {Animals ; Animals, Domestic/*parasitology ; Caribbean Region ; Colombia/epidemiology ; Tick-Borne Diseases/epidemiology ; Ticks/*microbiology/*parasitology ; }, abstract = {Tick-borne diseases constitute a problem for livestock and public health. Given the socio-economic and environmental conditions of the Colombian Caribbean, ticks are particularly abundant, in turn exposing domestic animals and people in contact with them to such diseases. This study evaluates the presence of Babesia spp., Anaplasma spp., Coxiella spp. and Borrelia spp. in domestic animal ticks (Amblyomma mixtum, A. dissimile, Dermacentor nitens, Rhipicephalus sanguineus and R. microplus) by conventional PCR. Findings show a prevalence of 12.5% of Babesia, 0% of Borrelia, 39.4% of Anaplasma and 52.9% of Coxiella, whereas 6.2% of a total sample of 104 tick pools presented coinfections between Babesia and Anaplasma. Among the molecularly identified species are Ba. vogeli, Ba. bigemina and A. marginale, in addition to two Coxiella species-one being C. mudrowiae and the other similar to an undescribed endosymbiont of Rhipicephalus sp. It is necessary to evaluate the vector capacity of ticks such as A. mixtum, D. nitens and R. sanguineus in the transmission of A. marginale. Moreover, it is necessary to explore the role that bacteria of the genus Coxiella might have both in the health of humans and animals, and in the metabolism and reproduction of ticks. This is the first report on Babesia vogeli and B. bigemina in ticks from the Colombian Caribbean, representing a risk to animal and human health.}, }
@article {pmid32809024, year = {2020}, author = {Kucuk, RA}, title = {Gut Bacteria in the Holometabola: A Review of Obligate and Facultative Symbionts.}, journal = {Journal of insect science (Online)}, volume = {20}, number = {4}, pages = {}, pmid = {32809024}, issn = {1536-2442}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Bacterial Physiological Phenomena ; *Gastrointestinal Microbiome ; Holometabola/*microbiology ; Symbiosis/*physiology ; }, abstract = {The diversity and ecological variety of Holometabola foregrounds a wide array of dynamic symbiotic relationships with gut-dwelling bacteria. A review of the literature highlights that holometabolous insects rely on both obligate bacteria and facultative bacteria living in their guts to satisfy a number of physiological needs. The driving forces behind these differing relationships can be hypothesized through the scrutiny of bacterial associations with host gut morphology, and transmission of bacteria within a given host taxon. Our knowledge of the evolution of facultative or obligate symbiotic bacteria in holometabolan systems is further enhanced by an assessment of the various services the bacteria provide, including nutrition, immune system health, and development. The diversity of Holometabola can thus be examined through an assessment of known bacterial partnerships within the orders of Holometabola.}, }
@article {pmid32806647, year = {2020}, author = {Poquita-Du, RC and Goh, YL and Huang, D and Chou, LM and Todd, PA}, title = {Gene Expression and Photophysiological Changes in Pocillopora acuta Coral Holobiont Following Heat Stress and Recovery.}, journal = {Microorganisms}, volume = {8}, number = {8}, pages = {}, pmid = {32806647}, issn = {2076-2607}, abstract = {The ability of corals to withstand changes in their surroundings is a critical survival mechanism for coping with environmental stress. While many studies have examined responses of the coral holobiont to stressful conditions, its capacity to reverse responses and recover when the stressor is removed is not well-understood. In this study, we investigated among-colony responses of Pocillopora acuta from two sites with differing distance to the mainland (Kusu (closer to the mainland) and Raffles Lighthouse (further from the mainland)) to heat stress through differential expression analysis of target genes and quantification of photophysiological metrics. We then examined how these attributes were regulated after the stressor was removed to assess the recovery potential of P. acuta. The fragments that were subjected to heat stress (2 °C above ambient levels) generally exhibited significant reduction in their endosymbiont densities, but the extent of recovery following stress removal varied depending on natal site and colony. There were minimal changes in chl a concentration and maximum quantum yield (Fv/Fm, the proportion of variable fluorescence (Fv) to maximum fluorescence (Fm)) in heat-stressed corals, suggesting that the algal endosymbionts' Photosystem II was not severely compromised. Significant changes in gene expression levels of selected genes of interest (GOI) were observed following heat exposure and stress removal among sites and colonies, including Actin, calcium/calmodulin-dependent protein kinase type IV (Camk4), kinesin-like protein (KIF9), and small heat shock protein 16.1 (Hsp16.1). The most responsive GOIs were Actin, a major component of the cytoskeleton, and the adaptive immune-related Camk4 which both showed significant reduction following heat exposure and subsequent upregulation during the recovery phase. Our findings clearly demonstrate specific responses of P. acuta in both photophysiological attributes and gene expression levels, suggesting differential capacity of P. acuta corals to tolerate heat stress depending on the colony, so that certain colonies may be more resilient than others.}, }
@article {pmid32801211, year = {2020}, author = {Kaltenpoth, M}, title = {An endosymbiont's journey through metamorphosis of its insect host.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {35}, pages = {20994-20996}, pmid = {32801211}, issn = {1091-6490}, mesh = {Animals ; Insecta ; Metamorphosis, Biological ; *Symbiosis ; *Weevils ; }, }
@article {pmid32801177, year = {2020}, author = {Pilgrim, J and Siozios, S and Baylis, M and Hurst, GDD}, title = {Tissue Tropisms and Transstadial Transmission of a Rickettsia Endosymbiont in the Highland Midge, Culicoides impunctatus (Diptera: Ceratopogonidae).}, journal = {Applied and environmental microbiology}, volume = {86}, number = {20}, pages = {}, pmid = {32801177}, issn = {1098-5336}, support = {BBS/E/I/00001701/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/M011186/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/M012441/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Ceratopogonidae/*microbiology ; Female ; In Situ Hybridization, Fluorescence ; Insect Vectors/*microbiology ; Male ; Phylogeny ; Rickettsia/*physiology ; *Symbiosis ; Tropism ; }, abstract = {Rickettsia is a genus of intracellular bacteria which can manipulate host reproduction and alter sensitivity to natural enemy attack in a diverse range of arthropods. The maintenance of Rickettsia endosymbionts in insect populations can be achieved through both vertical and horizontal transmission routes. For example, the presence of the symbiont in the follicle cells and salivary glands of Bemisia whiteflies allows Belli group Rickettsia transmission via the germ line and plants, respectively. However, the transmission routes of other Rickettsia bacteria, such as those in the Torix group of the genus, remain underexplored. Through fluorescence in situ hybridization (FISH) and transmission electron microscopy (TEM) screening, this study describes the pattern of Torix Rickettsia tissue tropisms in the highland midge, Culicoides impunctatus (Diptera: Ceratopogonidae). Of note is the high intensity of infection of the ovarian suspensory ligament, suggestive of a novel germ line targeting strategy. Additionally, localization of the symbiont in tissues of several developmental stages suggests transstadial transmission is a major route for ensuring maintenance of Rickettsia within C. impunctatus populations. Aside from providing insights into transmission strategies, the presence of Rickettsia bacteria in the fat body of larvae indicates potential host fitness and vector capacity impacts to be investigated in the future.IMPORTANCE Microbial symbionts of disease vectors have garnered recent attention due to their ability to alter vectorial capacity. Their consideration as a means of arbovirus control depends on symbiont vertical transmission, which leads to spread of the bacteria through a population. Previous work has identified a Rickettsia symbiont present in several species of biting midges (Culicoides spp.), which transmit bluetongue and Schmallenberg arboviruses. However, symbiont transmission strategies and host effects remain underexplored. In this study, we describe the presence of Rickettsia in the ovarian suspensory ligament of Culicoides impunctatus Infection of this organ suggests the connective tissue surrounding developing eggs is important for ensuring vertical transmission of the symbiont in midges and possibly other insects. Additionally, our results indicate Rickettsia localization in the fat body of Culicoides impunctatus As the arboviruses spread by midges often replicate in the fat body, this location implies possible symbiont-virus interactions to be further investigated.}, }
@article {pmid32797213, year = {2021}, author = {Martinez, J and Klasson, L and Welch, JJ and Jiggins, FM}, title = {Life and Death of Selfish Genes: Comparative Genomics Reveals the Dynamic Evolution of Cytoplasmic Incompatibility.}, journal = {Molecular biology and evolution}, volume = {38}, number = {1}, pages = {2-15}, pmid = {32797213}, issn = {1537-1719}, support = {/WT_/Wellcome Trust/United Kingdom ; 281668/ERC_/European Research Council/International ; WT202888/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; WT094664MA/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Drosophila/microbiology/physiology ; *Evolution, Molecular ; Female ; *Genome, Bacterial ; Host-Pathogen Interactions/*genetics ; Male ; *Repetitive Sequences, Nucleic Acid ; Spermatozoa/physiology ; Wolbachia/*genetics ; }, abstract = {Cytoplasmic incompatibility is a selfish reproductive manipulation induced by the endosymbiont Wolbachia in arthropods. In males Wolbachia modifies sperm, leading to embryonic mortality in crosses with Wolbachia-free females. In females, Wolbachia rescues the cross and allows development to proceed normally. This provides a reproductive advantage to infected females, allowing the maternally transmitted symbiont to spread rapidly through host populations. We identified homologs of the genes underlying this phenotype, cifA and cifB, in 52 of 71 new and published Wolbachia genome sequences. They are strongly associated with cytoplasmic incompatibility. There are up to seven copies of the genes in each genome, and phylogenetic analysis shows that Wolbachia frequently acquires new copies due to pervasive horizontal transfer between strains. In many cases, the genes have subsequently acquired loss-of-function mutations to become pseudogenes. As predicted by theory, this tends to occur first in cifB, whose sole function is to modify sperm, and then in cifA, which is required to rescue the cross in females. Although cif genes recombine, recombination is largely restricted to closely related homologs. This is predicted under a model of coevolution between sperm modification and embryonic rescue, where recombination between distantly related pairs of genes would create a self-incompatible strain. Together, these patterns of gene gain, loss, and recombination support evolutionary models of cytoplasmic incompatibility.}, }
@article {pmid32789571, year = {2020}, author = {Pavlinec, &#x17d; and Zupičić, IG and Oraić, D and Petani, B and Mustać, B and Mihaljević, &#x17d; and Beck, R and Zrnčić, S}, title = {Assessment of predominant bacteria in noble pen shell (Pinna nobilis) collected in the Eastern Adriatic Sea.}, journal = {Environmental monitoring and assessment}, volume = {192}, number = {9}, pages = {581}, doi = {10.1007/s10661-020-08541-6}, pmid = {32789571}, issn = {1573-2959}, mesh = {Animals ; Bacteria ; *Bivalvia ; *Ecosystem ; Environmental Monitoring ; Mediterranean Sea ; Phylogeny ; RNA, Ribosomal, 16S ; Vibrio ; }, abstract = {Noble pen shell (Pinna nobilis) is an endemic species and the largest known bivalve in the Mediterranean Sea. By filtering large amounts of water, they maintain a high percentage of organic matter, hence playing an important role in the marine ecosystem. The ecological community of pen shells is impressive, and there are numerous microorganisms present in its soft tissues. Since this species is highly endangered due to recently described mass mortalities throughout the Mediterranean, this study was aimed at finding out more about its microbiome. In this study, we identified the predominant bacterial populations of specimens collected at three separate locations along the Eastern Adriatic coast. The predominant bacteria were isolated and 16S rRNA sequencing was performed to identify eight different bacterial genera: Aestuariibacter sp., Aliivibrio sp., Alteromonas sp., Marinobacter sp., Pseudoalteromonas sp., Rubritalea sp., Thalassospira sp. and the Vibrio splendidus clade. The identified genera are ubiquitous in the marine environment and have previously been described as both beneficial symbionts and potential pathogens in other molluscs. There was a clear difference in the predominant bacterial populations between northern and southern sampling sites, which could be linked to water temperature. These findings indicate the need for expanded sampling over a longer time period, since more exhaustive research would provide information vital to the conservation of this critically endangered species.}, }
@article {pmid32788982, year = {2020}, author = {N Miyata, M and Nomura, M and Kageyama, D}, title = {Wolbachia have made it twice: Hybrid introgression between two sister species of Eurema butterflies.}, journal = {Ecology and evolution}, volume = {10}, number = {15}, pages = {8323-8330}, pmid = {32788982}, issn = {2045-7758}, abstract = {Wolbachia, cytoplasmically inherited endosymbionts of arthropods, are known to hijack their host reproduction in various ways to increase their own vertical transmission. This may lead to the selective sweep of associated mitochondria, which can have a large impact on the evolution of mitochondrial lineages. In Japan, two different Wolbacahia strains (wCI and wFem) are found in two sister species of pierid butterflies, Eurema mandarina and Eurema hecabe. In both species, females infected with wCI (C females) produce offspring with a nearly 1:1 sex ratio, while females infected with both wCI and wFem (CF females) produce all-female offspring. Previous studies have suggested the historical occurrence of hybrid introgression in C individuals between the two species. Furthermore, hybrid introgression in CF individuals is suggested by the distinct mitochondrial lineages between C females and CF females of E. mandarina. In this study, we performed phylogenetic analyses based on nuclear DNA and mitochondrial DNA markers of E. hecabe with previously published data on E. mandarina. We found that the nuclear DNA of this species significantly diverged from that of E. mandarina. By contrast, mitochondrial DNA haplotypes comprised two clades, mostly reflecting Wolbachia infection status rather than the individual species. Collectively, our results support the previously suggested occurrence of two independent historical events wherein the cytoplasms of CF females and C females moved between E. hecabe and E. mandarina through hybrid introgression.}, }
@article {pmid32787974, year = {2020}, author = {Wong, ML and Liew, JWK and Wong, WK and Pramasivan, S and Mohamed Hassan, N and Wan Sulaiman, WY and Jeyaprakasam, NK and Leong, CS and Low, VL and Vythilingam, I}, title = {Natural Wolbachia infection in field-collected Anopheles and other mosquito species from Malaysia.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {414}, pmid = {32787974}, issn = {1756-3305}, mesh = {Aedes/microbiology ; Animals ; Anopheles/microbiology ; Bacterial Outer Membrane Proteins/genetics ; Culex/microbiology ; Culicidae/*microbiology ; Genes, Bacterial ; Insect Control ; Malaysia/epidemiology ; Malvaceae/microbiology ; Mosquito Vectors/microbiology ; Pathology, Molecular ; Phylogeny ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Vector Borne Diseases/prevention &amp; control ; *Wolbachia/genetics/isolation &amp; purification ; }, abstract = {BACKGROUND: The endosymbiont bacterium Wolbachia is maternally inherited and naturally infects some filarial nematodes and a diverse range of arthropods, including mosquito vectors responsible for disease transmission in humans. Previously, it has been found infecting most mosquito species but absent in Anopheles and Aedes aegypti. However, recently these two mosquito species were found to be naturally infected with Wolbachia. We report here the extent of Wolbachia infections in field-collected mosquitoes from Malaysia based on PCR amplification of the Wolbachia wsp and 16S rRNA genes.<br><br>METHODS: The prevalence of Wolbachia in Culicinae mosquitoes was assessed via PCR with wsp primers. For some of the mosquitoes, in which the wsp primers failed to amplify a product, Wolbachia screening was performed using nested PCR targeting the 16S rRNA gene. Wolbachia sequences were aligned using Geneious 9.1.6 software, analyzed with BLAST, and the most similar sequences were downloaded. Phylogenetic analyses were carried out with MEGA 7.0 software. Graphs were drawn with GraphPad Prism 8.0 software.<br><br>RESULTS: A total of 217 adult mosquitoes representing 26 mosquito species were screened. Of these, infections with Wolbachia were detected in 4 and 15 mosquito species using wsp and 16S rRNA primers, respectively. To our knowledge, this is the first time Wolbachia was detected using 16S rRNA gene amplification, in some Anopheles species (some infected with Plasmodium), Culex sinensis, Culex vishnui, Culex pseudovishnui, Mansonia bonneae and Mansonia annulifera. Phylogenetic analysis based on wsp revealed Wolbachia from most of the mosquitoes belonged to Wolbachia Supergroup B. Based on 16S rRNA phylogenetic analysis, the Wolbachia strain from Anopheles mosquitoes were more closely related to Wolbachia&#xa0;infecting Anopheles from Africa than from Myanmar.<br><br>CONCLUSIONS: Wolbachia was found infecting Anopheles and other important disease vectors such as Mansonia. Since Wolbachia can affect its host by reducing the life span and provide resistance to pathogen infection, several studies have suggested it as a potential innovative tool for vector/vector-borne disease control. Therefore, it is important to carry out further studies on natural Wolbachia infection in vector mosquitoes' populations as well as their long-term effects in new hosts and pathogen suppression.}, }
@article {pmid32779567, year = {2020}, author = {Curran, DM and Grote, A and Nursimulu, N and Geber, A and Voronin, D and Jones, DR and Ghedin, E and Parkinson, J}, title = {Modeling the metabolic interplay between a parasitic worm and its bacterial endosymbiont allows the identification of novel drug targets.}, journal = {eLife}, volume = {9}, number = {}, pages = {}, pmid = {32779567}, issn = {2050-084X}, support = {R21 AI126466/AI/NIAID NIH HHS/United States ; RGPIN-2014-06664//Natural Sciences and Engineering Research Council of Canada/International ; T32 AI007180/AI/NIAID NIH HHS/United States ; F31 AI131527/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/*drug effects/microbiology ; *Drug Evaluation, Preclinical ; Filariasis/*drug therapy ; Filaricides/*pharmacology ; Metabolic Networks and Pathways/drug effects ; Models, Biological ; *Symbiosis/drug effects ; Wolbachia/*drug effects ; }, abstract = {The filarial nematode Brugia malayi represents a leading cause of disability in the developing world, causing lymphatic filariasis in nearly 40 million people. Currently available drugs are not well-suited to mass drug administration efforts, so new treatments are urgently required. One potential vulnerability is the endosymbiotic bacteria Wolbachia-present in many filariae-which is vital to the worm. Genome scale metabolic networks have been used to study prokaryotes and protists and have proven valuable in identifying therapeutic targets, but have only been applied to multicellular eukaryotic organisms more recently. Here, we present iDC625, the first compartmentalized metabolic model of a parasitic worm. We used this model to show how metabolic pathway usage allows the worm to adapt to different environments, and predict a set of 102 reactions essential to the survival of B. malayi. We validated three of those reactions with drug tests and demonstrated novel antifilarial properties for all three compounds.}, }
@article {pmid32774328, year = {2020}, author = {Duan, R and Xu, H and Gao, S and Gao, Z and Wang, N}, title = {Effects of Different Hosts on Bacterial Communities of Parasitic Wasp Nasonia vitripennis.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1435}, pmid = {32774328}, issn = {1664-302X}, abstract = {Parasitism is a special interspecific relationship in insects. Unlike most other ectoparasites, Nasonia vitripennis spend most of its life cycle (egg, larvae, pupae, and early adult stage) inside the pupae of flies, which is covered with hard puparium. Microbes play important roles in host development and help insect hosts to adapt to various environments. How the microbes of parasitic wasp respond to different fly hosts living in such close relationships motivated this investigation. In this study, we used N. vitripennis and three different fly pupa hosts (Lucilia sericata, Sarcophaga marshalli, and Musca domestica) to address this question, as well as to illustrate the potential transfer of bacteria through the trophic food chains. We found that N. vitripennis from different fly pupa hosts showed distinct microbiota, which means that the different fly hosts could affect the bacterial communities of their parasitic wasps. Some bacteria showed potential horizontal transfer through the trophic food chains, from the food through the fly to the parasitic wasp. We also found that the heritable endosymbiont Wolbachia could transferred from the fly host to the parasite and correlated with the bacterial communities of the corresponding parasitic wasps. Our findings provide new insight to the microbial interactions between parasite and host.}, }
@article {pmid32770272, year = {2021}, author = {Thongprem, P and Davison, HR and Thompson, DJ and Lorenzo-Carballa, MO and Hurst, GDD}, title = {Incidence and Diversity of Torix Rickettsia-Odonata Symbioses.}, journal = {Microbial ecology}, volume = {81}, number = {1}, pages = {203-212}, pmid = {32770272}, issn = {1432-184X}, mesh = {Animals ; DNA Barcoding, Taxonomic ; Female ; Infectious Disease Transmission, Vertical ; Odonata/*microbiology ; Ovary/microbiology ; Rickettsia/classification/genetics/*physiology ; Rickettsia Infections/*transmission ; Symbiosis/*physiology ; }, abstract = {Heritable microbes are an important component of invertebrate biology, acting both as beneficial symbionts and reproductive parasites. Whilst most previous research has focussed on the 'Wolbachia pandemic', recent work has emphasised the importance of other microbial symbionts. In this study, we present a survey of odonates (dragonflies and damselflies) for torix group Rickettsia, following previous research indicating that this clade can be common in other aquatic insect groups. PCR assays were used to screen a broad range of odonates from two continents and revealed 8 of 76 species tested were infected with Rickettsia. We then conducted further deeper screening of UK representatives of the Coenagrionidae damselfly family, revealing 6 of 8 UK coenagrionid species to be positive for torix Rickettsia. Analysis of Rickettsia gene sequences supported multiple establishments of symbiosis in the group. Some strains were shared between UK coenagrionid species that shared mtDNA barcodes, indicating a likely route for mitochondrial introgression between sister species. There was also evidence of coinfecting Rickettsia strains in two species. FISH analysis indicated Rickettsia were observed in the ovarioles, consistent with heritable symbiosis. We conclude that torix Rickettsia represent an important associate of odonates, being found in a broad range of species from both Europe and South America. There is evidence that coinfection can occur, vertical transmission is likely, and that symbiont movement following hybridisation may underpin the lack of 'barcoding gap' between well-established species pairs in the genus. Future work should establish the biological significance of the symbioses observed.}, }
@article {pmid32765466, year = {2020}, author = {Liang, X and Liu, J and Bian, G and Xi, Z}, title = {Wolbachia Inter-Strain Competition and Inhibition of Expression of Cytoplasmic Incompatibility in Mosquito.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1638}, pmid = {32765466}, issn = {1664-302X}, abstract = {Successful field trials have been reported as part of the effort to develop the maternally transmitted endosymbiontic bacteria Wolbachia as an intervention agent for controlling mosquito vectors and their transmitted diseases. In order to further improve this novel intervention, artificially transinfected mosquitoes must be optimized to display maximum pathogen blocking, the desired cytoplasmic incompatibility (CI) pattern, and the lowest possible fitness cost. Achieving such optimization, however, requires a better understanding of the interactions between the host and various Wolbabachia strains and their combinations. Here, we transferred the Wolbachia wMel strain by embryonic microinjection into Aedes albopictus, resulting in the successful establishment of a transinfected line, HM (wAlbAwAlbBwMel), with a triple-strain infection comprising wMel, wAlbA, and wAlbB. Surprisingly, no CI was induced when the triply infected males were crossed with the wild-type GUA females or with another triply infected HC females carrying wPip, wAlbA, and wAlbB, but specific removal of wAlbA from the HM (wAlbAwAlbBwMel) line resulted in the expression of CI after crosses with lines infected by either one, two, or three strains of Wolbachia. The transinfected line showed perfect maternal transmission of the triple infection, with fluctuating egg hatch rates that improved to normal levels after repeated outcrosses with GUA line. Strain-specific qPCR assays showed that wMel and wAlbB were present at the highest densities in the ovaries and midguts, respectively, of the HM (wAlbAwAlbBwMel) mosquitoes. These finding suggest that introducing a novel strain of Wolbachia into a Wolbachia-infected host may result in complicated interactions between Wolbachia and the host and between the various Wolbachia strains, with competition likely to occur between strains in the same supergroup.}, }
@article {pmid32763167, year = {2020}, author = {Bourguignon, T and Kinjo, Y and Villa-Martín, P and Coleman, NV and Tang, Q and Arab, DA and Wang, Z and Tokuda, G and Hongoh, Y and Ohkuma, M and Ho, SYW and Pigolotti, S and Lo, N}, title = {Increased Mutation Rate Is Linked to Genome Reduction in Prokaryotes.}, journal = {Current biology : CB}, volume = {30}, number = {19}, pages = {3848-3855.e4}, doi = {10.1016/j.cub.2020.07.034}, pmid = {32763167}, issn = {1879-0445}, mesh = {Archaea/*genetics ; Bacteria/*genetics ; Evolution, Molecular ; Genetic Drift ; Genetic Variation/genetics ; Genome/genetics ; Genome, Bacterial/genetics ; Genomic Instability/*genetics ; Mutation ; Mutation Rate ; Phylogeny ; Population Density ; Prokaryotic Cells/metabolism ; Selection, Genetic/genetics ; }, abstract = {The evolutionary processes that drive variation in genome size across the tree of life remain unresolved. Effective population size (Ne) is thought to play an important role in shaping genome size [1-3]-a key example being the reduced genomes of insect endosymbionts, which undergo population bottlenecks during transmission [4]. However, the existence of reduced genomes in marine and terrestrial prokaryote species with large Ne indicate that genome reduction is influenced by multiple processes [3]. One candidate process is enhanced mutation rate, which can increase adaptive capacity but can also promote gene loss. To investigate evolutionary forces associated with prokaryotic genome reduction, we performed molecular evolutionary and phylogenomic analyses of nine lineages from five bacterial and archaeal phyla. We found that gene-loss rate strongly correlated with synonymous substitution rate (a proxy for mutation rate) in seven of the nine lineages. However, gene-loss rate showed weak or no correlation with the ratio of nonsynonymous/synonymous substitution rate (dN/dS). These results indicate that genome reduction is largely associated with increased mutation rate, while the association between gene loss and changes in Ne is less well defined. Lineages with relatively high dS and dN, as well as smaller genomes, lacked multiple DNA repair genes, providing a proximate cause for increased mutation rates. Our findings suggest that similar mechanisms drive genome reduction in both intracellular and free-living prokaryotes, with implications for developing a comprehensive theory of prokaryote genome size evolution.}, }
@article {pmid32760836, year = {2020}, author = {Papa, A and Tsioka, K and Daskou, MA and Minti, F and Papadopoulou, E and Melidou, A and Giadinis, N}, title = {Application of 16S rRNA next generation sequencing in ticks in Greece.}, journal = {Heliyon}, volume = {6}, number = {7}, pages = {e04542}, pmid = {32760836}, issn = {2405-8440}, abstract = {Tick-borne bacteria pose a significant threat to human and veterinary public health. Greece is a Mediterranean country with rich tick fauna and the most commonly detected tick-borne bacterial pathogens are members of the Rickettsia and Anaplasma species. The variable V2-V4 and V6-V9 regions of 16S rRNA gene of seven ticks belonging to four genera representative in Greece (Ixodes, Rhipicephalus, Dermacentor, Haemophyssalis) were analysed using multiple primer pairs by next generation sequencing (NGS). Nine bacterial phyla corresponding to 95 families, 116 genera and 172 species were identified. Proteobacteria was the predominant phylum in five of the seven ticks, followed by Actinobacteria, which predominated in two ticks. The tick-borne bacteria included Rickettsia and Anaplasma species, while "Candidatus Midichloria mitochondrii" were detected in high abundance in I. ricinus ticks and less in Rhipicephalus bursa; Coxiella-like endosymbionts were detected in Rh. sanguineus, H. parva, and less in Rh. bursa ticks. Co-infections with Rickettsia and Anaplasma were also observed. 16S rRNA NGS is a powerful tool to investigate the tick bacteriome and can improve the strategies for prevention and control of tick-borne diseases.}, }
@article {pmid32759662, year = {2020}, author = {Hu, FY and Tsai, CW}, title = {Nutritional Relationship between Bemisia tabaci and Its Primary Endosymbiont, Portiera aleyrodidarum, during Host Plant Acclimation.}, journal = {Insects}, volume = {11}, number = {8}, pages = {}, pmid = {32759662}, issn = {2075-4450}, abstract = {Plant sap-sucking insects commonly have established mutualistic relationships with endosymbiotic bacteria that can provide nutrients lacking in their diet. Bemisia tabaci harbors one primary endosymbiont, Portiera aleyrodidarum, and up to seven secondary endosymbionts, including Hamiltonella defensa and Rickettsia sp. Portiera aleyrodidarum is already known to play a critical role in providing necessary nutrients for B. tabaci. In the present study, the relationship among B. tabaci, its primary endosymbiont, and the host plant were examined through the effects of host plant shifting and acclimation. Bemisia tabaci was transferred from Chinese kale to four different host plants, and the effects on both its performance and the expression levels of nutrient-related genes of P. aleyrodidarum were analyzed. The results showed that host shifting from Chinese kale to cotton plants led to a decrease in the performance of B. tabaci in the first generation, which was restored after 10 generations of acclimation. Furthermore, the expression levels of essential amino acid biosynthesis genes of P. aleyrodidarum were found to be differentially regulated after B. tabaci had acclimated to the cotton plants. Host plant shifting and acclimation to cucumber, poinsettia, and tomato plants did not affect the fecundity of B. tabaci and the expression levels of most examined genes. We speculate that P. aleyrodidarum may help B. tabaci improve its performance and acclimate to new hosts and that P. aleyrodidarum has a close nutritional relationship with its host during host plant acclimation.}, }
@article {pmid32748037, year = {2020}, author = {Ashour, DS and Othman, AA}, title = {Parasite-bacteria interrelationship.}, journal = {Parasitology research}, volume = {119}, number = {10}, pages = {3145-3164}, pmid = {32748037}, issn = {1432-1955}, mesh = {Animals ; Anti-Bacterial Agents/therapeutic use ; Arthropods/microbiology ; Bacterial Infections/*complications ; Filarioidea/*microbiology ; Humans ; Parasites/microbiology ; Parasitic Diseases/*complications ; Probiotics/therapeutic use ; Schistosoma haematobium/*microbiology ; Symbiosis ; Urinary Bladder Neoplasms/microbiology/parasitology/pathology ; Wolbachia/*growth &amp; development ; }, abstract = {Parasites and bacteria have co-evolved with humankind, and they interact all the time in a myriad of ways. For example, some bacterial infections result from parasite-dwelling bacteria as in the case of Salmonella infection during schistosomiasis. Other bacteria synergize with parasites in the evolution of human disease as in the case of the interplay between Wolbachia endosymbiont bacteria and filarial nematodes as well as the interaction between Gram-negative bacteria and Schistosoma haematobium in the pathogenesis of urinary bladder cancer. Moreover, secondary bacterial infections may complicate several parasitic diseases such as visceral leishmaniasis and malaria, due to immunosuppression of the host during parasitic infections. Also, bacteria may colonize the parasitic lesions; for example, hydatid cysts and skin lesions of ectoparasites. Remarkably, some parasitic helminths and arthropods exhibit antibacterial activity usually by the release of specific antimicrobial products. Lastly, some parasite-bacteria interactions are induced as when using probiotic bacteria to modulate the outcome of a variety of parasitic infections. In sum, parasite-bacteria interactions involve intricate processes that never cease to intrigue the researchers. However, understanding and exploiting these interactions could have prophylactic and curative potential for infections by both types of pathogens.}, }
@article {pmid32737539, year = {2021}, author = {Takamatsu, T and Arai, H and Abe, N and Nakai, M and Kunimi, Y and Inoue, MN}, title = {Coexistence of Two Male-Killers and Their Impact on the Development of Oriental Tea Tortrix Homona magnanima.}, journal = {Microbial ecology}, volume = {81}, number = {1}, pages = {193-202}, pmid = {32737539}, issn = {1432-184X}, mesh = {Animals ; Female ; Male ; Moths/*microbiology ; RNA Virus Infections/*mortality ; RNA Viruses/*pathogenicity ; Reproduction/*physiology ; Spiroplasma/*physiology ; Wolbachia/metabolism ; }, abstract = {Male-killing, the death of male offspring induced by maternally transmitted microbes, is classified as early, or late, male-killing. The primary advantage afforded by early male-killing, which typically occurs during embryogenesis, is the reallocation of resources to females, that would have otherwise been consumed by males. Meanwhile, the key advantage of late male-killing, which typically occurs during late larval development, is the maximized potential for horizontal transmission. To date, no studies have reported on the associated developmental and physiological effects of host coinfection with early and late male-killers, which may have a significant impact on the population dynamics of the male-killers. Here we used a lepidopteran tea pest Homona magnanima as a model, which is a unique system wherein an early male-killer (a Spiroplasma bacterium) and a late male-killer (an RNA virus) can coexist in nature. An artificially established matriline, coinfected with both Spiroplasma and RNA virus, exhibited embryonic death (early male-killing) as seen in the host line singly infected with Spiroplasma. Moreover, the coinfected line also exhibited developmental retardation and low pupal weight similar to the host line singly infected with the RNA virus. A series of field surveys revealed that Spiroplasma-RNA virus coinfection occurs in nature at a low frequency. Hence, although the two male-killers are capable of coexisting within the H. magnanima population independently, high associated fitness cost appears to limit the prevalence of male-killer coinfection in the field host population.}, }
@article {pmid32736314, year = {2020}, author = {Bass, D and Del Campo, J}, title = {Microeukaryotes in animal and plant microbiomes: Ecologies of disease?.}, journal = {European journal of protistology}, volume = {76}, number = {}, pages = {125719}, doi = {10.1016/j.ejop.2020.125719}, pmid = {32736314}, issn = {1618-0429}, mesh = {Animals ; DNA Primers/genetics ; DNA, Protozoan/genetics ; Disease ; Eukaryota/*classification ; Host-Parasite Interactions/*physiology ; *Microbiota/genetics ; Plants/*parasitology ; *Symbiosis ; }, abstract = {Studies of animal and plant microbiomes are burgeoning, but the majority of these focus on bacteria and rarely include microeukaryotes other than fungi. However, there is growing evidence that microeukaryotes living on and in larger organisms (e.g. plants, animals, macroalgae) are diverse and in many cases abundant. We present here a new combination of 'anti-metazoan' primers: 574*f-UNonMet_DB that amplify a wide diversity of microeukaryotes including some groups that are difficult to amplify using other primer combinations. While many groups of microeukaryotic parasites are recognised, myriad other microeukaryotes are associated with hosts as previously unknown parasites (often genetically divergent so difficult to amplify using standard PCR primers), opportunistic parasites, commensals, and other ecto- and endo-symbionts, across the 'symbiotic continuum'. These fulfil a wide range of roles from pathogenesis to mutually beneficial symbioses, but mostly their roles are unknown and likely fall somewhere along this spectrum, with the potential to switch the nature of their interactions with the host under different conditions. The composition and dynamics of host-associated microbial communities are also increasingly recognised as important moderators of host health. This 'pathobiome' approach to understanding disease is beginning to supercede a one-pathogen-one-disease paradigm, which cannot sufficiently explain many disease scenarios.}, }
@article {pmid32733401, year = {2020}, author = {Pasqualetti, C and Szokoli, F and Rindi, L and Petroni, G and Schrallhammer, M}, title = {The Obligate Symbiont "Candidatus Megaira polyxenophila" Has Variable Effects on the Growth of Different Host Species.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1425}, pmid = {32733401}, issn = {1664-302X}, abstract = {"Candidatus Megaira polyxenophila" is a recently described member of Rickettsiaceae which comprises exclusively obligate intracellular bacteria. Interestingly, these bacteria can be found in a huge diversity of eukaryotic hosts (protist, green algae, metazoa) living in marine, brackish or freshwater habitats. Screening of amplicon datasets revealed a high frequency of these bacteria especially in freshwater environments, most likely associated to eukaryotic hosts. The relationship of "Ca. Megaira polyxenophila" with their hosts and their impact on host fitness have not been studied so far. Even less is known regarding the responses of these intracellular bacteria to potential stressors. In this study, we used two phylogenetically close species of the freshwater ciliate Paramecium, Paramecium primaurelia and Paramecium pentaurelia (Ciliophora, Oligohymenophorea) naturally infected by "Ca. Megaira polyxenophila". In order to analyze the effect of the symbiont on the fitness of these two species, we compared the growth performance of both infected and aposymbiotic paramecia at different salinity levels in the range of freshwater and oligohaline brackish water i.e., at 0, 2, and 4.5 ppt. For the elimination of "Ca. Megaira polyxenophila" we established an antibiotic treatment to obtain symbiont-free lines and confirmed its success by fluorescence in situ hybridization (FISH). The population and infection dynamics during the growth experiment were observed by cell density counts and FISH. Paramecia fitness was compared applying generalized additive mixed models. Surprisingly, both infected Paramecium species showed higher densities under all salinity concentrations. The tested salinity concentrations did not significantly affect the growth of any of the two species directly, but we observed the loss of the endosymbiont after prolonged exposure to higher salinity levels. This experimental data might explain the higher frequency of "Ca. M. polyxenophila" in freshwater habitats as observed from amplicon data.}, }
@article {pmid32732238, year = {2020}, author = {Sato, Y and Wippler, J and Wentrup, C and Woyke, T and Dubilier, N and Kleiner, M}, title = {High-Quality Draft Genome Sequences of the Uncultured Delta3 Endosymbiont (Deltaproteobacteria) Assembled from Metagenomes of the Gutless Marine Worm Olavius algarvensis.}, journal = {Microbiology resource announcements}, volume = {9}, number = {31}, pages = {}, pmid = {32732238}, issn = {2576-098X}, abstract = {Here, we present two high-quality, draft metagenome-assembled genomes of deltaproteobacterial OalgDelta3 endosymbionts from the gutless marine worm Olavius algarvensis Their 16S rRNA gene sequences share 98% identity with Delta3 endosymbionts of related host species Olavius ilvae (GenBank accession no. AJ620501) and Inanidrilus exumae (GenBank accession no. FM202060), for which no symbiont genomes are available.}, }
@article {pmid32732049, year = {2020}, author = {Satta, CT and Pulina, S and Reñé, A and Padedda, BM and Caddeo, T and Fois, N and Lugliè, A}, title = {Ecological, morphological and molecular characterization of Kryptoperidinium sp. (Dinophyceae) from two Mediterranean coastal shallow lagoons.}, journal = {Harmful algae}, volume = {97}, number = {}, pages = {101855}, doi = {10.1016/j.hal.2020.101855}, pmid = {32732049}, issn = {1878-1470}, mesh = {*Dinoflagellida/genetics ; *Ecosystem ; Italy ; Phylogeny ; Salinity ; }, abstract = {In this study, the field ecology of Kryptoperidinium sp. was examined in two Mediterranean shallow lagoons, Calich (CA) and Santa Giusta (SG) in Sardinia, Italy. Kryptoperidinium cell density and the environmental conditions were examined monthly from 2008 to 2015 in CA and from 2011 to 2016 in SG. Cell morphology was determined by observing specimens taken from the field and from cultures that were established by single-cell isolation from samples collected in the two lagoons. The molecular identity of strains from each lagoon was also ascertained. The growth rates of the strains were determined under three different temperature conditions and six salinity treatments. The two wild populations shared the same morphology and the cultured strains were morphologically and molecularly identical. The SSU and 5.8S phylogenies show the presence of two clusters within the available Kryptoperidinium sequences and the strains obtained in this study clustered with others from the Mediterranean and Baltic. The multiannual dynamics of Kryptoperidinium sp. in the field significantly differed in the two lagoons, showing much higher cell densities in CA than in SG. The presence of Kryptoperidinium sp. was detected throughout the year in CA, with recurrent blooms also affecting the adjacent coastal area. In contrast, Kryptoperidinium sp. was sporadically observed in SG. The variation in the environmental parameters was fairly wide during the presence and blooms of Kryptoperidinium sp., especially in CA. The application of Generalized Linear Models to the field data revealed a significant role of rainfall and dissolved inorganic nitrogen on the presence and blooms of the species. Although growth rates were similar between the two strains, significant differences were detected for the 10 and 40 salinity treatments. The results obtained in this study add to our knowledge about the ecology of a harmful species that is not well understood in transitional ecosystems such as Mediterranean lagoons.}, }
@article {pmid32731621, year = {2020}, author = {Garrido, C and Caspari, OD and Choquet, Y and Wollman, FA and Lafontaine, I}, title = {Evidence Supporting an Antimicrobial Origin of Targeting Peptides to Endosymbiotic Organelles.}, journal = {Cells}, volume = {9}, number = {8}, pages = {}, pmid = {32731621}, issn = {2073-4409}, mesh = {Anti-Infective Agents/*metabolism ; Humans ; Organelles/*metabolism ; Peptides/*metabolism ; Symbiosis/*genetics ; }, abstract = {Mitochondria and chloroplasts emerged from primary endosymbiosis. Most proteins of the endosymbiont were subsequently expressed in the nucleo-cytosol of the host and organelle-targeted via the acquisition of N-terminal presequences, whose evolutionary origin remains enigmatic. Using a quantitative assessment of their physico-chemical properties, we show that organelle targeting peptides, which are distinct from signal peptides targeting other subcellular compartments, group with a subset of antimicrobial peptides. We demonstrate that extant antimicrobial peptides target a fluorescent reporter to either the mitochondria or the chloroplast in the green alga Chlamydomonas reinhardtii and, conversely, that extant targeting peptides still display antimicrobial activity. Thus, we provide strong computational and functional evidence for an evolutionary link between organelle-targeting and antimicrobial peptides. Our results support the view that resistance of bacterial progenitors of organelles to the attack of host antimicrobial peptides has been instrumental in eukaryogenesis and in the emergence of photosynthetic eukaryotes.}, }
@article {pmid32727924, year = {2020}, author = {Tabima, JF and Trautman, IA and Chang, Y and Wang, Y and Mondo, S and Kuo, A and Salamov, A and Grigoriev, IV and Stajich, JE and Spatafora, JW}, title = {Phylogenomic Analyses of Non-Dikarya Fungi Supports Horizontal Gene Transfer Driving Diversification of Secondary Metabolism in the Amphibian Gastrointestinal Symbiont, Basidiobolus.}, journal = {G3 (Bethesda, Md.)}, volume = {10}, number = {9}, pages = {3417-3433}, pmid = {32727924}, issn = {2160-1836}, mesh = {Amphibians ; Animals ; *Entomophthorales ; Fungi ; *Gene Transfer, Horizontal ; Phylogeny ; Secondary Metabolism ; }, abstract = {Research into secondary metabolism (SM) production by fungi has resulted in the discovery of diverse, biologically active compounds with significant medicinal applications. The fungi rich in SM production are taxonomically concentrated in the subkingdom Dikarya, which comprises the phyla Ascomycota and Basidiomycota. Here, we explore the potential for SM production in Mucoromycota and Zoopagomycota, two phyla of nonflagellated fungi that are not members of Dikarya, by predicting and identifying core genes and gene clusters involved in SM. The majority of non-Dikarya have few genes and gene clusters involved in SM production except for the amphibian gut symbionts in the genus BasidiobolusBasidiobolus genomes exhibit an enrichment of SM genes involved in siderophore, surfactin-like, and terpene cyclase production, all these with evidence of constitutive gene expression. Gene expression and chemical assays also confirm that Basidiobolus has significant siderophore activity. The expansion of SMs in Basidiobolus are partially due to horizontal gene transfer from bacteria, likely as a consequence of its ecology as an amphibian gut endosymbiont.}, }
@article {pmid32726353, year = {2020}, author = {Fraser, JE and O'Donnell, TB and Duyvestyn, JM and O'Neill, SL and Simmons, CP and Flores, HA}, title = {Novel phenotype of Wolbachia strain wPip in Aedes aegypti challenges assumptions on mechanisms of Wolbachia-mediated dengue virus inhibition.}, journal = {PLoS pathogens}, volume = {16}, number = {7}, pages = {e1008410}, pmid = {32726353}, issn = {1553-7374}, support = {102591/Z/13/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/*microbiology ; Animals ; Dengue/prevention &amp; control/transmission ; *Dengue Virus ; Gram-Negative Bacterial Infections ; Microbial Interactions/*physiology ; Mosquito Vectors/*microbiology ; Pest Control, Biological/methods ; Phenotype ; *Wolbachia ; }, abstract = {The bacterial endosymbiont Wolbachia is a biocontrol tool that inhibits the ability of the Aedes aegypti mosquito to transmit positive-sense RNA viruses such as dengue and Zika. Growing evidence indicates that when Wolbachia strains wMel or wAlbB are introduced into local mosquito populations, human dengue incidence is reduced. Despite the success of this novel intervention, we still do not fully understand how Wolbachia protects mosquitoes from viral infection. Here, we demonstrate that the Wolbachia strain wPip does not inhibit virus infection in Ae. aegypti. We have leveraged this novel finding, and a panel of Ae. aegypti lines carrying virus-inhibitory (wMel and wAlbB) and non-inhibitory (wPip) strains in a common genetic background, to rigorously test a number of hypotheses about the mechanism of Wolbachia-mediated virus inhibition. We demonstrate that, contrary to previous suggestions, there is no association between a strain's ability to inhibit dengue infection in the mosquito and either its typical density in the midgut or salivary glands, or the degree to which it elevates innate immune response pathways in the mosquito. These findings, and the experimental platform provided by this panel of genetically comparable mosquito lines, clear the way for future investigations to define how Wolbachia prevents Ae. aegypti from transmitting viruses.}, }
@article {pmid32723830, year = {2020}, author = {Maire, J and Parisot, N and Galvao Ferrarini, M and Vallier, A and Gillet, B and Hughes, S and Balmand, S and Vincent-Monégat, C and Zaidman-Rémy, A and Heddi, A}, title = {Spatial and morphological reorganization of endosymbiosis during metamorphosis accommodates adult metabolic requirements in a weevil.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {32}, pages = {19347-19358}, pmid = {32723830}, issn = {1091-6490}, mesh = {Animals ; Bacterial Physiological Phenomena ; Biological Evolution ; Digestive System/microbiology ; Endophytes/genetics/isolation &amp; purification/physiology ; Enterobacteriaceae/genetics/isolation &amp; purification/*physiology ; Female ; Larva/growth &amp; development/microbiology/physiology ; Male ; Metamorphosis, Biological ; *Symbiosis ; Weevils/*growth &amp; development/*microbiology/physiology ; }, abstract = {Bacterial intracellular symbiosis (endosymbiosis) is widespread in nature and impacts many biological processes. In holometabolous symbiotic insects, metamorphosis entails a complete and abrupt internal reorganization that creates a constraint for endosymbiont transmission from larvae to adults. To assess how endosymbiosis copes-and potentially evolves-throughout this major host-tissue reorganization, we used the association between the cereal weevil Sitophilus oryzae and the bacterium Sodalis pierantonius as a model system. S. pierantonius are contained inside specialized host cells, the bacteriocytes, that group into an organ, the bacteriome. Cereal weevils require metabolic inputs from their endosymbiont, particularly during adult cuticle synthesis, when endosymbiont load increases dramatically. By combining dual RNA-sequencing analyses and cell imaging, we show that the larval bacteriome dissociates at the onset of metamorphosis and releases bacteriocytes that undergo endosymbiosis-dependent transcriptomic changes affecting cell motility, cell adhesion, and cytoskeleton organization. Remarkably, bacteriocytes turn into spindle cells and migrate along the midgut epithelium, thereby conveying endosymbionts to midgut sites where future mesenteric caeca will develop. Concomitantly, endosymbiont genes encoding a type III secretion system and a flagellum apparatus are transiently up-regulated while endosymbionts infect putative stem cells and enter their nuclei. Infected cells then turn into new differentiated bacteriocytes and form multiple new bacteriomes in adults. These findings show that endosymbiosis reorganization in a holometabolous insect relies on a synchronized host-symbiont molecular and cellular "choreography" and illustrates an adaptive feature that promotes bacteriome multiplication to match increased metabolic requirements in emerging adults.}, }
@article {pmid32723650, year = {2020}, author = {Rahal, M and Medkour, H and Diarra, AZ and Bitam, I and Parola, P and Mediannikov, O}, title = {Molecular identification and evaluation of Coxiella-like endosymbionts genetic diversity carried by cattle ticks in Algeria.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {5}, pages = {101493}, doi = {10.1016/j.ttbdis.2020.101493}, pmid = {32723650}, issn = {1877-9603}, mesh = {Algeria ; Animals ; Coxiella/classification/genetics/*isolation &amp; purification ; Genes, Bacterial ; Genes, rRNA ; *Genetic Variation ; Ixodidae/*microbiology ; Species Specificity ; *Symbiosis ; }, abstract = {Coxiella-like bacteria are a large group of yet-to-isolate and characterize bacteria phylogenetically close to the agent of Q fever, Coxiella burnetii, and often associated with ixodid ticks worldwide. This study was designed to assess the presence of Coxiella-like endosymbionts (CLE) in ticks and to describe their genetic diversity in different tick species infesting cattle in Algeria. A total of 765 ticks were collected from three locations. The screening of 20 % of sampled ticks (147/765) exhibited the presence of Coxiella-like in 51.7 % (76/147). The sequencing of partial 16S rRNA and the GroEl genes showed an identity higher than 98 % with different Coxiella-like endosymbionts. The phylogenetic analysis based on the 16S rRNA gene showed the positions of identified Coxiella bacteria. Eleven of the 13 sequences from Rhipicephalus, Dermacentor and Hyalomma ticks were grouped in a distinct clade, the other two each represent an independent clade. This study reported that CLE are prevalent in cattle ticks. Most of the identified Coxiella-like bacteria, from different species of ticks found on cattle, were identical. This may mean that, unlike the currently accepted paradigm, Coxiella-like bacteria are not only tick host-associated, but rather can be transmitted from one tick species to another via the vertebrate host.}, }
@article {pmid32722516, year = {2020}, author = {Chen, H and Zhang, M and Hochstrasser, M}, title = {The Biochemistry of Cytoplasmic Incompatibility Caused by Endosymbiotic Bacteria.}, journal = {Genes}, volume = {11}, number = {8}, pages = {}, pmid = {32722516}, issn = {2073-4425}, support = {R01 GM053756/GM/NIGMS NIH HHS/United States ; R35 GM136325/GM/NIGMS NIH HHS/United States ; GM046904 and GM053756/NH/NIH HHS/United States ; }, mesh = {Animals ; Cytoplasm/*microbiology/*pathology ; Drosophila melanogaster/*microbiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Many species of arthropods carry maternally inherited bacterial endosymbionts that can influence host sexual reproduction to benefit the bacterium. The most well-known of such reproductive parasites is Wolbachia pipientis. Wolbachia are obligate intracellular α-proteobacteria found in nearly half of all arthropod species. This success has been attributed in part to their ability to manipulate host reproduction to favor infected females. Cytoplasmic incompatibility (CI), a phenomenon wherein Wolbachia infection renders males sterile when they mate with uninfected females, but not infected females (the rescue mating), appears to be the most common. CI provides a reproductive advantage to infected females in the presence of a threshold level of infected males. The molecular mechanisms of CI and other reproductive manipulations, such as male killing, parthenogenesis, and feminization, have remained mysterious for many decades. It had been proposed by Werren more than two decades ago that CI is caused by a Wolbachia-mediated sperm modification and that rescue is achieved by a Wolbachia-encoded rescue factor in the infected egg. In the past few years, new research has highlighted a set of syntenic Wolbachia gene pairs encoding CI-inducing factors (Cifs) as the key players for the induction of CI and its rescue. Within each Cif pair, the protein encoded by the upstream gene is denoted A and the downstream gene B. To date, two types of Cifs have been characterized based on the enzymatic activity identified in the B protein of each protein pair; one type encodes a deubiquitylase (thus named CI-inducing deubiquitylase or cid), and a second type encodes a nuclease (named CI-inducing nuclease or cin). The CidA and CinA proteins bind tightly and specifically to their respective CidB and CinB partners. In transgenic Drosophila melanogaster, the expression of either the Cid or Cin protein pair in the male germline induces CI and the expression of the cognate A protein in females is sufficient for rescue. With the identity of the Wolbachia CI induction and rescue factors now known, research in the field has turned to directed studies on the molecular mechanisms of CI, which we review here.}, }
@article {pmid32719697, year = {2020}, author = {Izarra, ML and Panta, AL and Maza, CR and Zea, BC and Cruzado, J and Gutarra, LR and Rivera, CR and Ellis, D and Kreuze, JF}, title = {Identification and Control of Latent Bacteria in in vitro Cultures of Sweetpotato [Ipomoea batatas (L.) Lam].}, journal = {Frontiers in plant science}, volume = {11}, number = {}, pages = {903}, pmid = {32719697}, issn = {1664-462X}, abstract = {Bacterial microorganisms which are latent in in vitro cultures can limit the efficiency of in vitro methods for the conservation of genetic resources. In this study we screened 2,373 accessions from the in vitro sweetpotato germplasm collection of the International Potato Center in Lima, Peru for bacteria associated with plantlets in tissue culture through a combination of morphological methods and partial 16S rDNA sequencing. Bacteria were detected in 240 accessions (10% of the accessions screened) and we were able to isolate 184 different bacterial isolates from 177 different accessions. These corresponded to at least nineteen Operational Taxonomic Units (OTUs) of bacteria, belonging to the genera Sphingomonas, Bacillus, Paenibacillus, Methylobacterium, Brevibacterium, Acinetobacter, Microbacterium, Streptomyces, Staphylococcus, and Janibacter. Specific primers were developed for PCR based diagnostic tests that were able to rapidly detect these bacteria directly from tissue culture plants, without the need of microbial sub-culturing. Based on PCR screening the largest bacterial OTUs corresponded to a Paenibacillus sp. closely related to Paenibacillus taichungensis (41.67%), and Bacillus sp. closely related to Bacillus cereus (22.22%), and Bacillus pumilus (16.67%). Since in vitro plant genetic resources must be microbe-free for international distribution and use, any microbial presence is considered a contamination and therefore it is critical to clean all cultures of these latent-appearing bacteria. To accomplish this, plantlets from in vitro were transferred to soil, watered with Dimanin[®] (2 ml/l) weekly and then reintroduced into in vitro. Of the 191 accessions processed for bacterial elimination, 100% tested bacteria-free after treatment. It is suspected that these bacteria may be endosymbionts and some may be beneficial for the plants.}, }
@article {pmid32718933, year = {2020}, author = {Chung, M and Basting, PJ and Patkus, RS and Grote, A and Luck, AN and Ghedin, E and Slatko, BE and Michalski, M and Foster, JM and Bergman, CM and Hotopp, JCD}, title = {A Meta-Analysis of Wolbachia Transcriptomics Reveals a Stage-Specific Wolbachia Transcriptional Response Shared Across Different Hosts.}, journal = {G3 (Bethesda, Md.)}, volume = {10}, number = {9}, pages = {3243-3260}, pmid = {32718933}, issn = {2160-1836}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Filarioidea ; *Nematoda ; Symbiosis ; Transcriptome ; *Wolbachia/genetics ; }, abstract = {Wolbachia is a genus containing obligate, intracellular endosymbionts with arthropod and nematode hosts. Numerous studies have identified differentially expressed transcripts in Wolbachia endosymbionts that potentially inform the biological interplay between these endosymbionts and their hosts, albeit with discordant results. Here, we re-analyze previously published Wolbachia RNA-Seq transcriptomics data sets using a single workflow consisting of the most up-to-date algorithms and techniques, with the aim of identifying trends or patterns in the pan-Wolbachia transcriptional response. We find that data from one of the early studies in filarial nematodes did not allow for robust conclusions about Wolbachia differential expression with these methods, suggesting the original interpretations should be reconsidered. Across datasets analyzed with this unified workflow, there is a general lack of global gene regulation with the exception of a weak transcriptional response resulting in the upregulation of ribosomal proteins in early larval stages. This weak response is observed across diverse Wolbachia strains from both nematode and insect hosts suggesting a potential pan-Wolbachia transcriptional response during host development that diverged more than 700 million years ago.}, }
@article {pmid32708808, year = {2020}, author = {Lindsey, ARI}, title = {Sensing, Signaling, and Secretion: A Review and Analysis of Systems for Regulating Host Interaction in Wolbachia.}, journal = {Genes}, volume = {11}, number = {7}, pages = {}, pmid = {32708808}, issn = {2073-4425}, support = {R01AI144430//National Institute of Allergy and Infectious Diseases/International ; }, mesh = {Animals ; Arthropods/microbiology ; Female ; Gene Expression Regulation, Bacterial ; Genome, Bacterial/genetics ; Host-Pathogen Interactions/genetics ; Nematoda/microbiology ; Quorum Sensing/*genetics ; Secretory Pathway/*genetics ; Signal Transduction/genetics ; Symbiosis/*genetics ; Wolbachia/genetics/metabolism/*physiology ; }, abstract = {Wolbachia (Anaplasmataceae) is an endosymbiont of arthropods and nematodes that resides within host cells and is well known for manipulating host biology to facilitate transmission via the female germline. The effects Wolbachia has on host physiology, combined with reproductive manipulations, make this bacterium a promising candidate for use in biological- and vector-control. While it is becoming increasingly clear that Wolbachia's effects on host biology are numerous and vary according to the host and the environment, we know very little about the molecular mechanisms behind Wolbachia's interactions with its host. Here, I analyze 29 Wolbachia genomes for the presence of systems that are likely central to the ability of Wolbachia to respond to and interface with its host, including proteins for sensing, signaling, gene regulation, and secretion. Second, I review conditions under which Wolbachia alters gene expression in response to changes in its environment and discuss other instances where we might hypothesize Wolbachia to regulate gene expression. Findings will direct mechanistic investigations into gene regulation and host-interaction that will deepen our understanding of intracellular infections and enhance applied management efforts that leverage Wolbachia.}, }
@article {pmid32696581, year = {2021}, author = {Suhag, A and Yadav, H and Chaudhary, D and Subramanian, S and Jaiwal, R and Jaiwal, PK}, title = {Biotechnological interventions for the sustainable management of a global pest, whitefly (Bemisia tabaci).}, journal = {Insect science}, volume = {28}, number = {5}, pages = {1228-1252}, doi = {10.1111/1744-7917.12853}, pmid = {32696581}, issn = {1744-7917}, mesh = {Animals ; *Biotechnology ; Crops, Agricultural ; *Hemiptera/genetics ; Insect Control/*methods ; *Insecticides ; Plants, Genetically Modified ; RNA Interference ; RNA, Double-Stranded ; }, abstract = {Whiteflies (Bemisia tabaci) are polyphagous invasive hemipteran insects that cause serious losses of important crops by directly feeding on phloem sap and transmitting pathogenic viruses. These insects have emerged as a major threat to global agriculture and food security. Chemically synthesized insecticides are currently the only option to control whiteflies, but the ability of whiteflies to evolve resistance against insecticides has made the management of these insects very difficult. Natural host-plant resistance against whiteflies identified in some crop plants has not been exploited to a great extent. Genetic engineering approaches, such as transgenics and RNA interference (RNAi), are potentially useful for the control of whiteflies. Transgenic plants harboring insecticidal toxins/lectins developed via nuclear or chloroplast transformation are a promising vehicle for whitefly control. Double-stranded RNAs (dsRNAs) of several insect genes, delivered either through microinjection into the insect body cavity or orally via an artificial diet and transiently or stably expressed in transgenic plants, have controlled whiteflies in model plants and in some crops at the laboratory level, but not at the field level. In this review, we highlight the merits and demerits of each delivery method along with strategies for sustained delivery of dsRNAs via fungal entomopathogen/endosymbiont or nontransgenic RNAi approaches, foliar sprays, root absorption or nanocarriers as well as the factors affecting efficient RNAi and their biosafety issues. Genome sequencing and transcriptome studies of whitefly species are facilitating the selection of appropriate genes for RNAi and gene-editing technology for the efficient and resilient management of whiteflies and their transmitted viruses.}, }
@article {pmid32690191, year = {2020}, author = {Jorrin, B and Palacios, JM and Peix, &#xc1; and Imperial, J}, title = {Rhizobium ruizarguesonis sp. nov., isolated from nodules of Pisum sativum L.}, journal = {Systematic and applied microbiology}, volume = {43}, number = {4}, pages = {126090}, doi = {10.1016/j.syapm.2020.126090}, pmid = {32690191}, issn = {1618-0984}, mesh = {DNA, Bacterial/genetics ; Fatty Acids/analysis ; Genes, Bacterial/genetics ; Genome, Bacterial/genetics ; Genotype ; Nucleic Acid Hybridization ; Peas/*microbiology ; Phenotype ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizobium/chemistry/*classification/cytology/*physiology ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Soil/chemistry ; Soil Microbiology ; Symbiosis ; }, abstract = {Four strains, coded as UPM1132, UPM1133[T], UPM1134 and UPM1135, and isolated from nodules of Pisum sativum plants grown on Ni-rich soils were characterised through a polyphasic taxonomy approach. Their 16S rRNA gene sequences were identical and showed 100% similarity with their closest phylogenetic neighbors, the species included in the 'R. leguminosarum group': R. laguerreae FB206[T], R. leguminosarum USDA 2370[T], R. anhuiense CCBAU 23252[T], R. sophoreae CCBAU 03386[T], R. acidisoli FH13[T] and R. hidalgonense FH14[T], and 99.6% sequence similarity with R. esperanzae CNPSo 668[T]. The analysis of combined housekeeping genes recA, atpD and glnII sequences showed similarities of 92-95% with the closest relatives. Whole genome average nucleotide identity (ANI) values were 97.5-99.7% ANIb similarity among the four strains, and less than 92.4% with closely related species, while digital DNA-DNA hybridization average values (dDDH) were 82-85% within our strains and 34-52% with closely related species. Major fatty acids in strain UPM1133[T] were C18:1 ω7c / C18:1 ω6c in summed feature 8, C14:0 3OH/ C16:1 iso I in summed feature 2 and C18:0. Colonies were small to medium, pearl-white coloured in YMA at 28°C and growth was observed in the ranges 8-34°C, pH 5.5-7.5 and 0-0.7% (w/v) NaCl. The DNA G+C content was 60.8mol %. The combined genotypic, phenotypic and chemotaxonomic data support the classification of strains UPM1132, UPM1133[T], UPM1134 and UPM1135 into a novel species of Rhizobium, for which the name Rhizobium ruizarguesonis sp. nov. is proposed. The type strain is UPM1133[T] (=CECT 9542[T]=LMG 30526[T]).}, }
@article {pmid32690078, year = {2020}, author = {Huang, EYY and Wong, AYP and Lee, IHT and Qu, Z and Yip, HY and Leung, CW and Yin, SM and Hui, JHL}, title = {Infection patterns of dengue, Zika and endosymbiont Wolbachia in the mosquito Aedes albopictus in Hong Kong.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {361}, pmid = {32690078}, issn = {1756-3305}, mesh = {*Aedes/microbiology/virology ; Animals ; Dengue/transmission ; Dengue Virus/*isolation &amp; purification ; Hong Kong/epidemiology ; Mosquito Vectors/virology ; Pathology, Molecular ; Polymerase Chain Reaction ; *Prevalence ; Symbiosis ; Wolbachia/*isolation &amp; purification ; Zika Virus/*isolation &amp; purification ; Zika Virus Infection/transmission ; }, abstract = {BACKGROUND: The mosquito Aedes albopictus is a vector of dengue and Zika viruses. Insecticide-resistant mosquito populations have evolved in recent decades, suggesting that new control strategies are needed. Hong Kong has a monsoon-influenced humid subtropical climate, which favours the spread of mosquitoes. However, baseline information on the composition and dynamics of the occurrence of endosymbiont Wolbachia in local Ae. albopictus is lacking, hindering the development of scientifically-informed control measures. This study identifies the presence and absence of dengue and Zika viruses, and Wolbachia infection in Aedes albopictus in Hong Kong.<br><br>METHODS: Oviposition traps were set at 57 areas in Hong Kong, and both immature and adult mosquitoes were collected on a monthly basis between April 2018 and April 2019 as the study sample. Each individual mosquito in this sample was processed and screened for the presence of the dengue and Zika viruses and the endosymbionts Wolbachia wAlbA and wAlbB with PCR.<br><br>RESULTS: Totals of 967 and 984 mosquitoes were tested respectively for the presence of dengue and Zika viruses, and no trace of either infection was found in these samples. The presence of wAlbA and wAlbB was also tested in 1582 individuals. Over 80% of these individuals were found to be stably infected with Wolbachia throughout the thirteen-month collection period (~&#x2009;47% singly-infected; ~&#x2009;36.8% doubly infected with both wAlbA and wAlbB).<br><br>CONCLUSIONS: The high degree of Wolbachia wAlbA and wAlbB infection in Ae. albopictus mosquitoes in Hong Kong, coupled with the absence of any signs of infection by dengue and Zika viruses, contrasts significantly with the pattern of mosquito infection in other parts of Asia. Further studies of the infection pattern in local mosquitoes are warranted before mosquito control strategies used in other regions are implemented in Hong Kong.}, }
@article {pmid32689950, year = {2020}, author = {Morrow, JL and Om, N and Beattie, GAC and Chambers, GA and Donovan, NJ and Liefting, LW and Riegler, M and Holford, P}, title = {Characterization of the bacterial communities of psyllids associated with Rutaceae in Bhutan by high throughput sequencing.}, journal = {BMC microbiology}, volume = {20}, number = {1}, pages = {215}, pmid = {32689950}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; Bhutan ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Rutaceae/microbiology/*parasitology ; Sequence Analysis, DNA/*methods ; }, abstract = {BACKGROUND: Several plant-pathogenic bacteria are transmitted by insect vector species that often also act as hosts. In this interface, these bacteria encounter plant endophytic, insect endosymbiotic and other microbes. Here, we used high throughput sequencing to examine the bacterial communities of five different psyllids associated with citrus and related plants of Rutaceae in Bhutan: Diaphorina citri, Diaphorina communis, Cornopsylla rotundiconis, Cacopsylla heterogena and an unidentified Cacopsylla sp.<br><br>RESULTS: The microbiomes of the psyllids largely comprised their obligate P-endosymbiont 'Candidatus Carsonella ruddii', and one or two S-endosymbionts that are fixed and specific to each lineage. In addition, all contained Wolbachia strains; the Bhutanese accessions of D. citri were dominated by a Wolbachia strain first found in American isolates of D. citri, while D. communis accessions were dominated by the Wolbachia strain, wDi, first detected in D. citri from China. The S-endosymbionts from the five psyllids grouped with those from other psyllid taxa; all D. citri and D. communis individuals contained sequences matching 'Candidatus Profftella armatura' that has previously only been reported from other Diaphorina species, and the remaining psyllid species contained OTUs related to unclassified Enterobacteriaceae. The plant pathogenic 'Candidatus Liberibacter asiaticus' was found in D. citri but not in D. communis. Furthermore, an unidentified 'Candidatus Liberibacter sp.' occurred at low abundance in both Co. rotundiconis and the unidentified Cacopsylla sp. sampled from Zanthoxylum sp.; the status of this new liberibacter as a plant pathogen and its potential plant hosts are currently unknown. The bacterial communities of Co. rotundiconis also contained a range of OTUs with similarities to bacteria previously found in samples taken from various environmental sources.<br><br>CONCLUSIONS: The bacterial microbiota detected in these Bhutanese psyllids support the trends that have been seen in previous studies: psyllids have microbiomes largely comprising their obligate P-endosymbiont and one or two S-endosymbionts. In addition, the association with plant pathogens has been demonstrated, with the detection of liberibacters in a known host, D. citri, and identification of a putative new species of liberibacter in Co. rotundiconis and Cacopsylla sp.}, }
@article {pmid32676060, year = {2020}, author = {Gupta, A and Nair, S}, title = {Dynamics of Insect-Microbiome Interaction Influence Host and Microbial Symbiont.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1357}, pmid = {32676060}, issn = {1664-302X}, abstract = {Insects share an intimate relationship with their gut microflora and this symbiotic association has developed into an essential evolutionary outcome intended for their survival through extreme environmental conditions. While it has been clearly established that insects, with very few exceptions, associate with several microbes during their life cycle, information regarding several aspects of these associations is yet to be fully unraveled. Acquisition of bacteria by insects marks the onset of microbial symbiosis, which is followed by the adaptation of these bacterial species to the gut environment for prolonged sustenance and successful transmission across generations. Although several insect-microbiome associations have been reported and each with their distinctive features, diversifications and specializations, it is still unclear as to what led to these diversifications. Recent studies have indicated the involvement of various evolutionary processes operating within an insect body that govern the transition of a free-living microbe to an obligate or facultative symbiont and eventually leading to the establishment and diversification of these symbiotic relationships. Data from various studies, summarized in this review, indicate that the symbiotic partners, i.e., the bacteria and the insect undergo several genetic, biochemical and physiological changes that have profound influence on their life cycle and biology. An interesting outcome of the insect-microbe interaction is the compliance of the microbial partner to its eventual genome reduction. Endosymbionts possess a smaller genome as compared to their free-living forms, and thus raising the question what is leading to reductive evolution in the microbial partner. This review attempts to highlight the fate of microbes within an insect body and its implications for both the bacteria and its insect host. While discussion on each specific association would be too voluminous and outside the scope of this review, we present an overview of some recent studies that contribute to a better understanding of the evolutionary trajectory and dynamics of the insect-microbe association and speculate that, in the future, a better understanding of the nature of this interaction could pave the path to a sustainable and environmentally safe way for controlling economically important pests of crop plants.}, }
@article {pmid32675189, year = {2020}, author = {Park, J and Xi, H and Park, J and Nam, SJ and Lee, YD}, title = {Complete Genome Sequence of the Blochmannia Endosymbiont of Camponotus nipponensis.}, journal = {Microbiology resource announcements}, volume = {9}, number = {29}, pages = {}, pmid = {32675189}, issn = {2576-098X}, abstract = {Blochmannia endosymbionts, belonging to Gammaproteobacteria, live in bacteriocytes, which are specialized cells for these bacterial species in the Camponotus genus (carpenter ants). In this announcement, we describe the complete genome sequence of the Blochmannia endosymbiont of Camponotus nipponensis, which originated from a C. nipponensis colony collected in the Republic of Korea.}, }
@article {pmid32668699, year = {2020}, author = {Chandra, S and Šlapeta, J}, title = {Biotic Factors Influence Microbiota of Nymph Ticks from Vegetation in Sydney, Australia.}, journal = {Pathogens (Basel, Switzerland)}, volume = {9}, number = {7}, pages = {}, pmid = {32668699}, issn = {2076-0817}, abstract = {Ticks are haematophagous ectoparasites of medical and veterinary significance due to their excellent vector capacity. Modern sequencing techniques enabled the rapid sequencing of bacterial pathogens and symbionts. This study's aims were two-fold; to determine the nymph diversity in Sydney, and to determine whether external biotic factors affect the microbiota. Tick DNA was isolated, and the molecular identity was determined for nymphs at the cox1 level. The tick DNA was subjected to high throughput DNA sequencing to determine the bacterial profile and the impact of biotic factors on the microbiota. Four nymph tick species were recovered from Sydney, NSW: Haemaphysalis bancrofti, Ixodes holocyclus, Ixodes trichosuri and Ixodes tasmani. Biotic factors, notably tick species and geography, were found to have a significance influence on the microbiota. The microbial analyses revealed that Sydney ticks display a core microbiota. The dominating endosymbionts among all tick species were Candidatus Midichloria sp. Ixholo1 and Candidatus Midichloria sp. Ixholo2. A novel Candidatus Midichloria sp. OTU_2090 was only found in I. holocyclus ticks (nymph: 96.3%, adult: 75.6%). Candidatus Neoehrlichia australis and Candidatus Neoehrlichia arcana was recovered from I. holocyclus and one I. trichosuri nymph ticks. Borrelia spp. was absent from all ticks. This study has shown that nymph and adult ticks carry different bacteria, and a tick bite in Sydney, Australia will result in different bacterial transfer depending on tick life stage, tick species and geography.}, }
@article {pmid32661403, year = {2020}, author = {Fan, L and Wu, D and Goremykin, V and Xiao, J and Xu, Y and Garg, S and Zhang, C and Martin, WF and Zhu, R}, title = {Phylogenetic analyses with systematic taxon sampling show that mitochondria branch within Alphaproteobacteria.}, journal = {Nature ecology &amp; evolution}, volume = {4}, number = {9}, pages = {1213-1219}, pmid = {32661403}, issn = {2397-334X}, mesh = {*Alphaproteobacteria/genetics ; Mitochondria/genetics ; Phylogeny ; Reproducibility of Results ; }, abstract = {Though it is well accepted that mitochondria originated from an alphaproteobacteria-like ancestor, the phylogenetic relationship of the mitochondrial endosymbiont to extant Alphaproteobacteria is yet unresolved. The focus of much debate is whether the affinity between mitochondria and fast-evolving alphaproteobacterial lineages reflects true homology or artefacts. Approaches such as site exclusion have been claimed to mitigate compositional heterogeneity between taxa, but this comes at the cost of information loss, and the reliability of such methods is so far unproven. Here we demonstrate that site-exclusion methods produce erratic phylogenetic estimates of mitochondrial origin. Thus, previous phylogenetic hypotheses on the origin of mitochondria based on pretreated datasets should be re-evaluated. We applied alternative strategies to reduce phylogenetic noise by systematic taxon sampling while keeping site substitution information intact. Cross-validation based on a series of trees placed mitochondria robustly within Alphaproteobacteria, sharing an ancient common ancestor with Rickettsiales and currently unclassified marine lineages.}, }
@article {pmid32651207, year = {2020}, author = {Guo, Y and Takashima, Y and Sato, Y and Narisawa, K and Ohta, H and Nishizawa, T}, title = {Mycoavidus sp. Strain B2-EB: Comparative Genomics Reveals Minimal Genomic Features Required by a Cultivable Burkholderiaceae-Related Endofungal Bacterium.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {18}, pages = {}, pmid = {32651207}, issn = {1098-5336}, mesh = {Burkholderiaceae/*genetics ; *Genome, Bacterial ; Genomics ; Mortierella/*pathogenicity ; *Symbiosis ; }, abstract = {Obligate bacterial endosymbionts are critical to the existence of many eukaryotes. Such endobacteria are usually characterized by reduced genomes and metabolic dependence on the host, which may cause difficulty in isolating them in pure cultures. Family Burkholderiaceae-related endofungal bacteria affiliated with the Mycoavidus-Glomeribacter clade can be associated with the fungal subphyla Mortierellomycotina and Glomeromycotina. In this study, a cultivable endosymbiotic bacterium, Mycoavidus sp. strain B2-EB, present in the fungal host Mortierella parvispora was obtained successfully. The B2-EB genome (1.88 Mb) represents the smallest genome among the endofungal bacterium Mycoavidus cysteinexigens (2.64-2.80 Mb) of Mortierella elongata and the uncultured endosymbiont "Candidatus Glomeribacter gigasporarum" (1.37 to 2.36 Mb) of arbuscular mycorrhizal fungi. Despite a reduction in genome size, strain B2-EB displays a high genome completeness, suggesting a nondegenerative reduction in the B2-EB genome. Compared with a large proportion of transposable elements (TEs) in other known Mycoavidus genomes (7.2 to 11.5% of the total genome length), TEs accounted for only 2.4% of the B2-EB genome. This pattern, together with a high proportion of single-copy genes in the B2-EB genome, suggests that the B2-EB genome reached a state of relative evolutionary stability. These results represent the most streamlined structure among the cultivable endofungal bacteria and suggest the minimal genome features required by both an endofungal lifestyle and artificial culture. This study allows us to understand the genome evolution of Burkholderiaceae-related endosymbionts and to elucidate microbiological interactions.IMPORTANCE This study attempted the isolation of a novel endobacterium, Mycoavidus sp. B2-EB (JCM 33615), harbored in the fungal host Mortierella parvispora E1425 (JCM 39028). We report the complete genome sequence of this strain, which possesses a reduced genome size with relatively high genome completeness and a streamlined genome structure. The information indicates the minimal genomic features required by both the endofungal lifestyle and artificial cultivation, which furthers our understanding of genome reduction in fungal endosymbionts and extends the culture resources for biotechnological development on engineering synthetic microbiomes.}, }
@article {pmid32639986, year = {2020}, author = {Gunderson, EL and Vogel, I and Chappell, L and Bulman, CA and Lim, KC and Luo, M and Whitman, JD and Franklin, C and Choi, YJ and Lefoulon, E and Clark, T and Beerntsen, B and Slatko, B and Mitreva, M and Sullivan, W and Sakanari, JA}, title = {The endosymbiont Wolbachia rebounds following antibiotic treatment.}, journal = {PLoS pathogens}, volume = {16}, number = {7}, pages = {e1008623}, pmid = {32639986}, issn = {1553-7374}, mesh = {Animals ; Brugia pahangi/*microbiology ; Female ; Filariasis/*microbiology ; Filaricides/*pharmacology ; Gerbillinae ; Rifampin/*pharmacology ; Wolbachia/*drug effects ; }, abstract = {Antibiotic treatment has emerged as a promising strategy to sterilize and kill filarial nematodes due to their dependence on their endosymbiotic bacteria, Wolbachia. Several studies have shown that novel and FDA-approved antibiotics are efficacious at depleting the filarial nematodes of their endosymbiont, thus reducing female fecundity. However, it remains unclear if antibiotics can permanently deplete Wolbachia and cause sterility for the lifespan of the adult worms. Concerns about resistance arising from mass drug administration necessitate a careful exploration of potential Wolbachia recrudescence. In the present study, we investigated the long-term effects of the FDA-approved antibiotic, rifampicin, in the Brugia pahangi jird model of infection. Initially, rifampicin treatment depleted Wolbachia in adult worms and simultaneously impaired female worm fecundity. However, during an 8-month washout period, Wolbachia titers rebounded and embryogenesis returned to normal. Genome sequence analyses of Wolbachia revealed that despite the population bottleneck and recovery, no genetic changes occurred that could account for the rebound. Clusters of densely packed Wolbachia within the worm's ovarian tissues were observed by confocal microscopy and remained in worms treated with rifampicin, suggesting that they may serve as privileged sites that allow Wolbachia to persist in worms while treated with antibiotic. To our knowledge, these clusters have not been previously described and may be the source of the Wolbachia rebound.}, }
@article {pmid32635864, year = {2020}, author = {Rosenwald, LC and Sitvarin, MI and White, JA}, title = {Endosymbiotic Rickettsiella causes cytoplasmic incompatibility in a spider host.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1930}, pages = {20201107}, pmid = {32635864}, issn = {1471-2954}, mesh = {Animals ; Coxiellaceae/*physiology ; Cytoplasm/*microbiology ; Female ; Host-Pathogen Interactions ; Male ; Spiders/*microbiology ; Symbiosis ; }, abstract = {Many arthropod hosts are infected with bacterial endosymbionts that manipulate host reproduction, but few bacterial taxa have been shown to cause such manipulations. Here, we show that a bacterial strain in the genus Rickettsiella causes cytoplasmic incompatibility (CI) between infected and uninfected hosts. We first surveyed the bacterial community of the agricultural spider Mermessus fradeorum (Linyphiidae) using high throughput sequencing and found that individual spiders can be infected with up to five different strains of maternally inherited symbiont from the genera Wolbachia, Rickettsia, and Rickettsiella. The Rickettsiella strain was pervasive, found in all 23 tested spider matrilines. We used antibiotic curing to generate uninfected matrilines that we reciprocally crossed with individuals infected only with Rickettsiella. We found that only 13% of eggs hatched when uninfected females were mated with Rickettsiella-infected males; in contrast, at least 83% of eggs hatched in the other cross types. This is the first documentation of Rickettsiella, or any Gammaproteobacteria, causing CI. We speculate that induction of CI may be much more widespread among maternally inherited bacteria than previously appreciated. Further, our results reinforce the importance of thoroughly characterizing and assessing the inherited microbiome before attributing observed host phenotypes to well-characterized symbionts such as Wolbachia.}, }
@article {pmid32630209, year = {2020}, author = {Khoo, JJ and Kurtti, TJ and Husin, NA and Beliavskaia, A and Lim, FS and Zulkifli, MMS and Al-Khafaji, AM and Hartley, C and Darby, AC and Hughes, GL and AbuBakar, S and Makepeace, BL and Bell-Sakyi, L}, title = {Isolation and Propagation of Laboratory Strains and a Novel Flea-Derived Field Strain of Wolbachia in Tick Cell Lines.}, journal = {Microorganisms}, volume = {8}, number = {7}, pages = {}, pmid = {32630209}, issn = {2076-2607}, support = {R21 AI138074/AI/NIAID NIH HHS/United States ; R21 AI129507/AI/NIAID NIH HHS/United States ; BB/P024378/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/P024270/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/T001240/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, abstract = {Wolbachia are intracellular endosymbionts of several invertebrate taxa, including insects and nematodes. Although Wolbachia DNA has been detected in ticks, its presence is generally associated with parasitism by insects. To determine whether or not Wolbachia can infect and grow in tick cells, cell lines from three tick species, Ixodes scapularis, Ixodes ricinus and Rhipicephalus microplus, were inoculated with Wolbachia strains wStri and wAlbB isolated from mosquito cell lines. Homogenates prepared from fleas collected from cats in Malaysia were inoculated into an I. scapularis cell line. Bacterial growth and identity were monitored by microscopy and PCR amplification and sequencing of fragments of Wolbachia genes. The wStri strain infected Ixodes spp. cells and was maintained through 29 passages. The wAlbB strain successfully infected Ixodes spp. and R. microplus cells and was maintained through 2-5 passages. A novel strain of Wolbachia belonging to the supergroup F, designated wCfeF, was isolated in I. scapularis cells from a pool of Ctenocephalides sp. cat fleas and maintained in vitro through two passages over nine months. This is the first confirmed isolation of a Wolbachia strain from a flea and the first isolation of any Wolbachia strain outside the "pandemic" A and B supergroups. The study demonstrates that tick cells can host multiple Wolbachia strains, and can be added to panels of insect cell lines to improve success rates in isolation of field strains of Wolbachia.}, }
@article {pmid32625188, year = {2020}, author = {Lima, RM and Kylarová, S and Mergaert, P and Kondorosi, &#xc9;}, title = {Unexplored Arsenals of Legume Peptides With Potential for Their Applications in Medicine and Agriculture.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1307}, pmid = {32625188}, issn = {1664-302X}, abstract = {During endosymbiosis, bacteria live intracellularly in the symbiotic organ of their host. The host controls the proliferation of endosymbionts and prevents their spread to other tissues and organs. In Rhizobium-legume symbiosis the major host effectors are secreted nodule-specific cysteine-rich (NCR) peptides, produced exclusively in the symbiotic cells. NCRs have evolved in the Inverted Repeat Lacking Clade (IRLC) of the Leguminosae family. They are secreted peptides that mediate terminal differentiation of the endosymbionts, forming polyploid, non-cultivable cells with increased membrane permeability. NCRs form an extremely large family of peptides, which have four or six conserved cysteines but otherwise highly diverse amino acid sequences, resulting in a wide variety of anionic, neutral and cationic peptides. In vitro, many synthetic NCRs have strong antimicrobial activities against both Gram-negative and Gram-positive bacteria, including the ESKAPE strains and pathogenic fungi. The spectra and minimal bactericidal and anti-fungal concentrations of NCRs differ, indicating that, in addition to their charge, the amino acid composition and sequence also play important roles in their antimicrobial activity. NCRs attack the bacteria and fungi at the cell envelope and membrane as well as intracellularly, forming interactions with multiple essential cellular machineries. NCR-like peptides with similar symbiotic functions as the NCRs also exist in other branches of the Leguminosae family. Thus, legumes provide countless and so far unexplored sources of symbiotic peptides representing an enormous resource of pharmacologically interesting molecules.}, }
@article {pmid32623757, year = {2020}, author = {Chauhan, C and Das De, T and Kumari, S and Rani, J and Sharma, P and Tevatiya, S and Pandey, KC and Pande, V and Dixit, R}, title = {Hemocyte-specific FREP13 abrogates the exogenous bacterial population in the hemolymph and promotes midgut endosymbionts in Anopheles stephensi.}, journal = {Immunology and cell biology}, volume = {98}, number = {9}, pages = {757-769}, doi = {10.1111/imcb.12374}, pmid = {32623757}, issn = {1440-1711}, mesh = {Animals ; *Anopheles/immunology ; Bacteria ; *Gastrointestinal Microbiome ; Hemocytes/*parasitology ; Hemolymph/*microbiology ; Insect Proteins/*genetics ; Plasmodium vivax ; Sporozoites ; Symbiosis ; }, abstract = {The immune blood cells "hemocytes" of mosquitoes impart a highly selective immune response against various microorganisms/pathogens. Among several immune effectors, fibrinogen-related proteins (FREPs) have been recognized as key modulators of cellular immune responses; however, their physiological relevance has not been investigated in detail. Our ongoing comparative RNA-sequencing analysis identified a total of 13 FREPs originating from naïve sugar-fed, blood-fed, bacterial challenged and Plasmodium vivax-infected hemocytes in Anopheles stephensi. Transcriptional profiling of the selected seven FREP transcripts showed distinct responses against different pathophysiological conditions, where an exclusive induction of FREP12 after 10 days of P. vivax infection was observed. This represents a possible role of FREP12 in immunity against free circulating sporozoites and needs to be explored in the future. When challenged with live bacterial injection in the thorax, we observed a higher affinity of FREP13 and FREP65 toward Gram-negative and Gram-positive bacteria in the mosquito hemocytes, respectively. Furthermore, we observed increased bacterial survival and proliferation, which is likely compromised by the downregulation of TEP1, in FREP13 messenger RNA-depleted mosquito hemolymph. In contrast, after blood-feeding, we also noticed a significant delay of 24 h in the enrichment of gut endosymbionts in the FREP13-silenced mosquitoes. Taken together, we conclude that hemocyte-specific FREP13 carries the unique ability of tissue-specific regulation, having an antagonistic antibacterial role in the hemolymph, and an agonistic role against gut endosymbionts.}, }
@article {pmid32621939, year = {2020}, author = {Heryanto, C and Eleftherianos, I}, title = {Nematode endosymbiont competition: Fortune favors the fittest.}, journal = {Molecular and biochemical parasitology}, volume = {238}, number = {}, pages = {111298}, doi = {10.1016/j.molbiopara.2020.111298}, pmid = {32621939}, issn = {1872-9428}, mesh = {Animals ; Bacteria/growth &amp; development/*metabolism ; Biological Factors/*biosynthesis ; Catechol Oxidase/metabolism ; Enzyme Precursors/metabolism ; Helminth Proteins/metabolism ; Hemolymph/microbiology/parasitology ; Insecta/microbiology/*parasitology ; Nematoda/enzymology/*microbiology/pathogenicity ; Nematode Infections/microbiology/*parasitology ; Phospholipases A2/metabolism ; Symbiosis/*physiology ; }, abstract = {Endosymbiotic bacteria that obligately associate with entomopathogenic nematodes as a complex are a unique model system to study competition. These nematodes seek an insect host and provide entry for their endosymbionts. Through their natural products, the endosymbionts nurture their nematodes by eliminating secondary infection, providing nutrients through bioconversion of the insect cadaver, and facilitating reproduction. On one hand, they cooperatively colonize the insect host and neutralize other opportunistic biotic threats. On the other hand, inside the insect cadaver as a fighting pit, they fiercely compete for the fittest partnership that will grant them the reproductive dominance. Here, we review the protective and nurturing nature of endosymbiotic bacteria for their nematodes and how their selective preference shapes the superior nematode-endosymbiont pairs as we know today.}, }
@article {pmid32621601, year = {2020}, author = {Yu, L and Li, T and Li, L and Lin, X and Li, H and Liu, C and Guo, C and Lin, S}, title = {SAGER: a database of Symbiodiniaceae and Algal Genomic Resource.}, journal = {Database : the journal of biological databases and curation}, volume = {2020}, number = {}, pages = {}, pmid = {32621601}, issn = {1758-0463}, mesh = {Animals ; Anthozoa ; Chlorophyta/genetics ; Computational Biology ; *Databases, Genetic ; Dinoflagellida/*genetics ; Phaeophyta/genetics ; Rhodophyta/genetics ; *Symbiosis ; Transcriptome/*genetics ; }, abstract = {Symbiodiniaceae dinoflagellates are essential endosymbionts of reef building corals and some other invertebrates. Information of their genome structure and function is critical for understanding coral symbiosis and bleaching. With the rapid development of sequencing technology, genome draft assemblies of several Symbiodiniaceae species and diverse marine algal genomes have become publicly available but spread in multiple separate locations. Here, we present a Symbiodiniaceae and Algal Genomic Resource Database (SAGER), a user-friendly online repository for integrating existing genomic data of Symbiodiniaceae species and diverse marine algal gene sets from MMETSP and PhyloDB databases. Relevant algal data are included to facilitate comparative analyses. The database is freely accessible at http://sampgr.org.cn. It provides comprehensive tools for studying gene function, expression and comparative genomics, including search tools to identify gene information from Symbiodiniaceae species, and BLAST tool to find orthologs from marine algae and protists. Moreover, SAGER integrates transcriptome datasets derived from diverse culture conditions of corresponding Symbiodiniaceae species. SAGER was developed with the capacity to incorporate future Symbiodiniaceae and algal genome and transcriptome data, and will serve as an open-access and sustained platform providing genomic and molecular tools that can be conveniently used to study Symbiodiniaceae and other marine algae. Database URL: http://sampgr.org.cn.}, }
@article {pmid32616636, year = {2020}, author = {Lebov, JF and Mattick, J and Libro, S and Sparklin, BC and Chung, M and Bromley, RE and Nadendla, S and Zhao, X and Ott, S and Sadzewicz, L and Tallon, LJ and Michalski, ML and Foster, JM and Dunning Hotopp, JC}, title = {Complete Genome Sequence of wBp, the Wolbachia Endosymbiont of Brugia pahangi FR3.}, journal = {Microbiology resource announcements}, volume = {9}, number = {27}, pages = {}, pmid = {32616636}, issn = {2576-098X}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, abstract = {Lymphatic filariasis is a devastating disease caused by filarial nematode roundworms, which contain obligate Wolbachia endosymbionts. Here, we assembled the genome of wBp, the Wolbachia endosymbiont of the filarial nematode Brugia pahangi, from Illumina, Pacific Biosciences, and Oxford Nanopore data. The complete, circular genome is 1,072,967 bp.}, }
@article {pmid32616041, year = {2020}, author = {Duan, XZ and Sun, JT and Wang, LT and Shu, XH and Guo, Y and Keiichiro, M and Zhu, YX and Bing, XL and Hoffmann, AA and Hong, XY}, title = {Recent infection by Wolbachia alters microbial communities in wild Laodelphax striatellus populations.}, journal = {Microbiome}, volume = {8}, number = {1}, pages = {104}, pmid = {32616041}, issn = {2049-2618}, support = {31672035 and 31871976//National Natural Science Foundation of China/International ; }, mesh = {Animals ; China ; Hemiptera/*microbiology ; Japan ; *Microbiota/genetics ; RNA, Ribosomal, 16S/genetics ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: Host-associated microbial communities play an important role in the fitness of insect hosts. However, the factors shaping microbial communities in wild populations, including genetic background, ecological factors, and interactions among microbial species, remain largely unknown.<br><br>RESULTS: Here, we surveyed microbial communities of the small brown planthopper (SBPH, Laodelphax striatellus) across 17 geographical populations in China and Japan by using 16S rRNA amplicon sequencing. Using structural equation models (SEM) and Mantel analyses, we show that variation in microbial community structure is likely associated with longitude, annual mean precipitation (Bio12), and mitochondrial DNA variation. However, a Wolbachia infection, which is spreading to northern populations of SBPH, seems to have a relatively greater role than abiotic factors in shaping microbial community structure, leading to sharp decreases in bacterial taxon diversity and abundance in host-associated microbial communities. Comparative RNA-Seq analyses between Wolbachia-infected and -uninfected strains indicate that the Wolbachia do not seem to alter the immune reaction of SBPH, although Wolbachia affected expression of metabolism genes.<br><br>CONCLUSION: Together, our results identify potential factors and interactions among different microbial species in the microbial communities of SBPH, which can have effects on insect physiology, ecology, and evolution. Video Abstract.}, }
@article {pmid32609768, year = {2020}, author = {Segura, JA and Isaza, JP and Botero, LE and Alzate, JF and Gutiérrez, LA}, title = {Assessment of bacterial diversity of Rhipicephalus microplus ticks from two livestock agroecosystems in Antioquia, Colombia.}, journal = {PloS one}, volume = {15}, number = {7}, pages = {e0234005}, pmid = {32609768}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*classification/genetics ; Cattle ; Cattle Diseases/microbiology ; Colombia ; Gastrointestinal Microbiome/genetics ; Livestock/genetics ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus/*genetics/*microbiology ; Saliva/chemistry ; Tick Infestations/veterinary ; Tick-Borne Diseases/epidemiology ; }, abstract = {Rhipicephalus microplus is recognized as a tick species highly prevalent in cattle, with a wide pantropical distribution that seems to continue spreading geographically. However, its role as a biological vector has been scarcely studied in the livestock context. In this study, a 16S rRNA next-generation sequencing analysis was used to determine bacterial diversity in salivary glands and gut of R. microplus from two contrasting livestock agroecosystems in Antioquia, Colombia. Both the culture-independent approach (CI) and the culture-dependent (CD) approach were complementarily adopted in this study. A total of 341 unique OTUs were assigned, the richness showed to be higher in the Northern than in the Middle Magdalena region, and a high diversity was found at the phylum and genus levels in the samples obtained. With the CI approach, Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria were the most common phylum of bacteria regardless of the organ, or geographic origin of the specimens analyzed. While the relative abundance of bacteria at a phylum level with the CD approach varied between analyzed samples, the data obtained suggest that a high diversity of species of bacteria occurs in R. microplus from both livestock agroecosystems. Bacterial genera such as Anaplasma, Coxiella, and Ehrlichia, recognized for their implications in tick-borne diseases, were also detected, together with endosymbionts such as Lysinibacillus, previously reported as a potential tool for biological control. This information is useful to deepen the knowledge about microbial diversity regarding the relations between endosymbionts and pathogens and could facilitate the future development of epidemiological surveillance in livestock systems.}, }
@article {pmid32605521, year = {2020}, author = {Keaney, TA and Wong, HWS and Dowling, DK and Jones, TM and Holman, L}, title = {Sibling rivalry versus mother's curse: can kin competition facilitate a response to selection on male mitochondria?.}, journal = {Proceedings. Biological sciences}, volume = {287}, number = {1930}, pages = {20200575}, pmid = {32605521}, issn = {1471-2954}, mesh = {Animals ; Drosophila melanogaster ; Female ; Haplotypes ; Male ; Maternal Inheritance ; *Mitochondria ; *Selection, Genetic ; Siblings ; }, abstract = {Assuming that fathers never transmit mitochondrial DNA (mtDNA) to their offspring, mitochondrial mutations that affect male fitness are invisible to direct selection on males, leading to an accumulation of male-harming alleles in the mitochondrial genome (mother's curse). However, male phenotypes encoded by mtDNA can still undergo adaptation via kin selection provided that males interact with females carrying related mtDNA, such as their sisters. Here, using experiments with Drosophila melanogaster carrying standardized nuclear DNA but distinct mitochondrial DNA, we test whether the mitochondrial haplotype carried by interacting pairs of larvae affects survival to adulthood, as well as the fitness of the adults. Although mtDNA had no detectable direct or indirect genetic effect on larva-to-adult survival, the fitness of male and female adults was significantly affected by their own mtDNA and the mtDNA carried by their social partner in the larval stage. Thus, mtDNA mutations that alter the effect of male larvae on nearby female larvae (which often carry the same mutation, due to kinship) could theoretically respond to kin selection. We discuss the implications of our findings for the evolution of mitochondria and other maternally inherited endosymbionts.}, }
@article {pmid32599512, year = {2020}, author = {Ferreira, AG and Fairlie, S and Moreira, LA}, title = {Insect vectors endosymbionts as solutions against diseases.}, journal = {Current opinion in insect science}, volume = {40}, number = {}, pages = {56-61}, doi = {10.1016/j.cois.2020.05.014}, pmid = {32599512}, issn = {2214-5753}, mesh = {Animals ; Communicable Disease Control/*methods ; Disease Transmission, Infectious/*prevention &amp; control ; Humans ; Insect Vectors/*physiology ; Insecta/*physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Viral diseases transmitted by mosquitoes, known as arboviruses, pose a significant threat to human life and are a major burden on many health systems around the world. Currently, arbovirus control strategies rely on insecticides or vector source reduction and, in the absence of effective, accessible and affordable vaccines, mainly on symptomatic based, non-specific treatments. However, insecticides have the potential to interfere with non-target organisms, cause environmental toxicity and insecticide resistance reduces their effectiveness as a sustainable control method. Complementary and sustainable strategies are urgently needed. Wolbachia, an invertebrate endosymbiont, has been used as an alternative strategy for arboviral control, through suppression or modification of mosquito populations. Here we discuss the burden that arboviruses impose on human populations and how Wolbachia can be used as a sustainable strategy for control, in alignment with the United Nations- 2030 Agenda for Sustainable Development.}, }
@article {pmid32596816, year = {2020}, author = {Wang, Q and Yuan, E and Ling, X and Zhu-Salzman, K and Guo, H and Ge, F and Sun, Y}, title = {An aphid facultative symbiont suppresses plant defence by manipulating aphid gene expression in salivary glands.}, journal = {Plant, cell &amp; environment}, volume = {43}, number = {9}, pages = {2311-2322}, doi = {10.1111/pce.13836}, pmid = {32596816}, issn = {1365-3040}, mesh = {Animals ; Aphids/genetics/microbiology/*physiology ; Calcium/metabolism ; China ; Gene Expression ; Insect Proteins/genetics ; Medicago truncatula/*physiology ; Plants, Genetically Modified ; Reactive Oxygen Species/metabolism ; Salivary Glands/*physiology ; Serratia/*physiology ; Symbiosis ; }, abstract = {Aphids often carry facultative symbionts to achieve diverse advantages. Serratia symbiotica, one of facultative endosymbionts, increases aphid tolerance to heat. However, whether it benefits aphid colonization on host plants is yet to be determined. In the current study, we found that Acyrthosiphon pisum harbouring S. symbiotica had longer feeding duration on Medicago truncatula than Serratia-free aphids. Contrastingly, Serratia-free aphids triggered higher accumulation of reactive oxygen species (ROS), jasmonic acid and salicylic acid responsive genes and cytosolic Ca[2+] elevations than Serratia-infected aphids. Transcriptomic analysis of salivary glands indicated that a histidine-rich Ca[2+] -binding protein-like gene (ApHRC) was expressed more highly in the salivary gland of Serratia-infected aphids than that of Serratia-free aphids. Once ApHRC was silenced, Serratia-infected aphids also displayed shorter phloem-feeding duration and caused Ca[2+] elevation and ROS accumulation in plants. Our results suggest that ApHRC, a potential effector up-regulated by S. symbiotica in the salivary glands, impairs plant defence response by suppressing Ca[2+] elevation and ROS accumulation, allowing colonization of aphids. This study has provided an insight into how facultative symbionts facilitate aphid colonization and adaptation to host plants.}, }
@article {pmid32592285, year = {2020}, author = {Sproles, AE and Oakley, CA and Krueger, T and Grossman, AR and Weis, VM and Meibom, A and Davy, SK}, title = {Sub-cellular imaging shows reduced photosynthetic carbon and increased nitrogen assimilation by the non-native endosymbiont Durusdinium trenchii in the model cnidarian Aiptasia.}, journal = {Environmental microbiology}, volume = {22}, number = {9}, pages = {3741-3753}, doi = {10.1111/1462-2920.15142}, pmid = {32592285}, issn = {1462-2920}, support = {1202//Marsden Fund of the Royal Society Te Ap&#x101;rangi/International ; }, mesh = {Animals ; Carbon/metabolism ; Dinoflagellida/genetics/*metabolism ; Metabolome ; Nitrogen/metabolism ; Photosynthesis ; Proteome ; Sea Anemones/genetics/*metabolism/microbiology ; Symbiosis ; Transcriptome ; }, abstract = {Hosting different symbiont species can affect inter-partner nutritional fluxes within the cnidarian-dinoflagellate symbiosis. Using nanoscale secondary ion mass spectrometry (NanoSIMS), we measured the spatial incorporation of photosynthetically fixed [13] C and heterotrophically derived [15] N into host and symbiont cells of the model symbiotic cnidarian Aiptasia (Exaiptasia pallida) when colonized with its native symbiont Breviolum minutum or the non-native Durusdinium trenchii. Breviolum minutum exhibited high photosynthetic carbon assimilation per cell and translocation to host tissue throughout symbiosis establishment, whereas D. trenchii assimilated significantly less carbon, but obtained more host nitrogen. These findings suggest that D. trenchii has less potential to provide photosynthetically fixed carbon to the host despite obtaining considerable amounts of heterotrophically derived nitrogen. These sub-cellular events help explain previous observations that demonstrate differential effects of D. trenchii compared to B. minutum on the host transcriptome, proteome, metabolome and host growth and asexual reproduction. Together, these differential effects suggest that the non-native host-symbiont pairing is sub-optimal with respect to the host's nutritional benefits under normal environmental conditions. This contributes to our understanding of the ways in which metabolic integration impacts the benefits of a symbiotic association, and the potential evolution of novel host-symbiont pairings.}, }
@article {pmid32589643, year = {2020}, author = {Ajene, IJ and Khamis, FM and van Asch, B and Pietersen, G and Rasowo, BA and Ombura, FL and Wairimu, AW and Akutse, KS and Sétamou, M and Mohamed, S and Ekesi, S}, title = {Microbiome diversity in Diaphorina citri populations from Kenya and Tanzania shows links to China.}, journal = {PloS one}, volume = {15}, number = {6}, pages = {e0235348}, pmid = {32589643}, issn = {1932-6203}, mesh = {Animals ; *Biodiversity ; China ; Drug Resistance, Microbial/genetics ; Hemiptera/*microbiology ; Insect Vectors/microbiology ; Kenya ; *Microbiota/drug effects/genetics ; *Phylogeny ; Plant Diseases/microbiology ; Sequence Analysis ; Symbiosis ; Tanzania ; }, abstract = {The Asian citrus psyllid (Diaphorina citri) is a key pest of Citrus spp. worldwide, as it acts as a vector for "Candidatus Liberibacter asiaticus (Las)", the bacterial pathogen associated with the destructive Huanglongbing (HLB) disease. Recent detection of D. citri in Africa and reports of Las-associated HLB in Ethiopia suggest that the citrus industry on the continent is under imminent threat. Endosymbionts and gut bacteria play key roles in the biology of arthropods, especially with regards to vector-pathogen interactions and resistance to antibiotics. Thus, we aim to profile the bacterial genera and to identify antibiotic resistance genes within the microbiome of different populations worldwide of D. citri. The metagenome of D. citri was sequenced using the Oxford Nanopore full-length 16S metagenomics protocol, and the "What's in my pot" (WIMP) analysis pipeline. Microbial diversity within and between D. citri populations was assessed, and antibiotic resistance genes were identified using the WIMP-ARMA workflow. The most abundant genera were key endosymbionts of D. citri ("Candidatus Carsonella", "Candidatus Profftella", and Wolbachia). The Shannon diversity index showed that D. citri from Tanzania had the highest diversity of bacterial genera (1.92), and D. citri from China had the lowest (1.34). The Bray-Curtis dissimilarity showed that China and Kenya represented the most diverged populations, while the populations from Kenya and Tanzania were the least diverged. The WIMP-ARMA analyses generated 48 CARD genes from 13 bacterial species in each of the populations. Spectinomycin resistance genes were the most frequently found, with an average of 65.98% in all the populations. These findings add to the knowledge on the diversity of the African D. citri populations and the probable introduction source of the psyllid in these African countries.}, }
@article {pmid32582067, year = {2020}, author = {Mateos, M and Martinez Montoya, H and Lanzavecchia, SB and Conte, C and Guillén, K and Morán-Aceves, BM and Toledo, J and Liedo, P and Asimakis, ED and Doudoumis, V and Kyritsis, GA and Papadopoulos, NT and Augustinos, AA and Segura, DF and Tsiamis, G}, title = {Wolbachia pipientis Associated With Tephritid Fruit Fly Pests: From Basic Research to Applications.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {1080}, pmid = {32582067}, issn = {1664-302X}, abstract = {Members of the true fruit flies (family Tephritidae) are among the most serious agricultural pests worldwide, whose control and management demands large and costly international efforts. The need for cost-effective and environmentally friendly integrated pest management (IPM) has led to the development and implementation of autocidal control strategies. These approaches include the widely used sterile insect technique and the incompatible insect technique (IIT). IIT relies on maternally transmitted bacteria (namely Wolbachia) to cause a conditional sterility in crosses between released mass-reared Wolbachia-infected males and wild females, which are either uninfected or infected with a different Wolbachia strain (i.e., cytoplasmic incompatibility; CI). Herein, we review the current state of knowledge on Wolbachia-tephritid interactions including infection prevalence in wild populations, phenotypic consequences, and their impact on life history traits. Numerous pest tephritid species are reported to harbor Wolbachia infections, with a subset exhibiting high prevalence. The phenotypic effects of Wolbachia have been assessed in very few tephritid species, due in part to the difficulty of manipulating Wolbachia infection (removal or transinfection). Based on recent methodological advances (high-throughput DNA sequencing) and breakthroughs concerning the mechanistic basis of CI, we suggest research avenues that could accelerate generation of necessary knowledge for the potential use of Wolbachia-based IIT in area-wide integrated pest management (AW-IPM) strategies for the population control of tephritid pests.}, }
@article {pmid32581834, year = {2020}, author = {Mannella, CA}, title = {Consequences of Folding the Mitochondrial Inner Membrane.}, journal = {Frontiers in physiology}, volume = {11}, number = {}, pages = {536}, pmid = {32581834}, issn = {1664-042X}, support = {P41 RR001219/RR/NCRR NIH HHS/United States ; U01 HL116321/HL/NHLBI NIH HHS/United States ; }, abstract = {A fundamental first step in the evolution of eukaryotes was infolding of the chemiosmotic membrane of the endosymbiont. This allowed the proto-eukaryote to amplify ATP generation while constraining the volume dedicated to energy production. In mitochondria, folding of the inner membrane has evolved into a highly regulated process that creates specialized compartments (cristae) tuned to optimize function. Internalizing the inner membrane also presents complications in terms of generating the folds and maintaining mitochondrial integrity in response to stresses. This review describes mechanisms that have evolved to regulate inner membrane topology and either preserve or (when appropriate) rupture the outer membrane.}, }
@article {pmid32575747, year = {2020}, author = {Miller, JW and Bocke, CR and Tresslar, AR and Schniepp, EM and DiSalvo, S}, title = {Paraburkholderia Symbionts Display Variable Infection Patterns That Are Not Predictive of Amoeba Host Outcomes.}, journal = {Genes}, volume = {11}, number = {6}, pages = {}, pmid = {32575747}, issn = {2073-4425}, mesh = {Amoeba/genetics/microbiology ; Burkholderiaceae/*genetics/pathogenicity ; Dictyostelium/*genetics/microbiology ; Genotype ; Host Microbial Interactions/genetics ; Host-Parasite Interactions/*genetics ; Phenotype ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Symbiotic interactions exist within a parasitism to mutualism continuum that is influenced, among others, by genes and context. Dynamics of intracellular invasion, replication, and prevalence may underscore both host survivability and symbiont stability. More infectious symbionts might exert higher corresponding costs to hosts, which could ultimately disadvantage both partners. Here, we quantify infection patterns of diverse Paraburkholderia symbiont genotypes in their amoeba host Dictyostelium discoideum and probe the relationship between these patterns and host outcomes. We exposed D. discoideum to thirteen strains of Paraburkholderia each belonging to one of the three symbiont species found to naturally infect D. discoideum: Paraburkholderia agricolaris, Paraburkholderia hayleyella, and Paraburkholderia bonniea. We quantified the infection prevalence and intracellular density of fluorescently labeled symbionts along with the final host population size using flow cytometry and confocal microscopy. We find that infection phenotypes vary across symbiont strains. Symbionts belonging to the same species generally display similar infection patterns but are interestingly distinct when it comes to host outcomes. This results in final infection loads that do not strongly correlate to final host outcomes, suggesting other genetic factors that are not a direct cause or consequence of symbiont abundance impact host fitness.}, }
@article {pmid32573833, year = {2020}, author = {Lucek, K and Butlin, RK and Patsiou, T}, title = {Secondary contact zones of closely-related Erebia butterflies overlap with narrow phenotypic and parasitic clines.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {9}, pages = {1152-1163}, doi = {10.1111/jeb.13669}, pmid = {32573833}, issn = {1420-9101}, mesh = {Animals ; Butterflies/anatomy &amp; histology/*genetics/microbiology ; Ecosystem ; *Gene Flow ; Hybridization, Genetic ; Phenotype ; *Reproductive Isolation ; Switzerland ; Wings, Animal/anatomy &amp; histology ; Wolbachia/genetics ; }, abstract = {Zones of secondary contact between closely related taxa are a common legacy of the Quaternary ice ages. Despite their abundance, the factors that keep species apart and prevent hybridization are often unknown. Here, we study a very narrow contact zone between three closely related butterfly species of the Erebia tyndarus species complex. Using genomic data, we first determined whether gene flow occurs and then assessed whether it might be hampered by differences in chromosome number between some species. We found interspecific gene flow between sibling species that differ in karyotype by one chromosome. Conversely, only F1 hybrids occurred between two species that have the same karyotype, forming a steep genomic cline. In a second step, we fitted clines to phenotypic, ecological and parasitic data to identify the factors associated with the genetic cline. We found clines for phenotypic data and the prevalence of the endosymbiont parasite Wolbachia to overlap with the genetic cline, suggesting that they might be drivers for separating the two species. Overall, our results highlight that some gene flow is possible between closely related species despite different chromosome numbers, but that other barriers restrict such gene flow.}, }
@article {pmid32560686, year = {2020}, author = {Driscoll, TP and Verhoeve, VI and Gillespie, JJ and Johnston, JS and Guillotte, ML and Rennoll-Bankert, KE and Rahman, MS and Hagen, D and Elsik, CG and Macaluso, KR and Azad, AF}, title = {A chromosome-level assembly of the cat flea genome uncovers rampant gene duplication and genome size plasticity.}, journal = {BMC biology}, volume = {18}, number = {1}, pages = {70}, pmid = {32560686}, issn = {1741-7007}, support = {R01 AI126853/AI/NIAID NIH HHS/United States ; R01 AI017828/AI/NIAID NIH HHS/United States ; R21 AI146773/AI/NIAID NIH HHS/United States ; R01 AI122672/AI/NIAID NIH HHS/United States ; R21AI26108/NH/NIH HHS/United States ; T32 AI095190/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Chromosomes ; Ctenocephalides/*genetics ; *DNA Copy Number Variations ; Female ; *Gene Duplication ; *Genome Size ; Male ; }, abstract = {BACKGROUND: Fleas (Insecta: Siphonaptera) are small flightless parasites of birds and mammals; their blood-feeding can transmit many serious pathogens (i.e., the etiological agents of bubonic plague, endemic and murine typhus). The lack of flea genome assemblies has hindered research, especially comparisons to other disease vectors. Accordingly, we sequenced the genome of the cat flea, Ctenocephalides felis, an insect with substantial human health and veterinary importance across the globe.<br><br>RESULTS: By combining Illumina and PacBio sequencing of DNA derived from multiple inbred female fleas with Hi-C scaffolding techniques, we generated a chromosome-level genome assembly for C. felis. Unexpectedly, our assembly revealed extensive gene duplication across the entire genome, exemplified by ~&#x2009;38% of protein-coding genes with two or more copies and over 4000 tRNA genes. A broad range of genome size determinations (433-551&#x2009;Mb) for individual fleas sampled across different populations supports the widespread presence of fluctuating copy number variation (CNV) in C. felis. Similarly, broad genome sizes were also calculated for individuals of Xenopsylla cheopis (Oriental rat flea), indicating that this remarkable "genome-in-flux" phenomenon could be a siphonapteran-wide trait. Finally, from the C. felis sequence reads, we also generated closed genomes for two novel strains of Wolbachia, one parasitic and one symbiotic, found to co-infect individual fleas.<br><br>CONCLUSION: Rampant CNV in C. felis has dire implications for gene-targeting pest control measures and stands to complicate standard normalization procedures utilized in comparative transcriptomics analysis. Coupled with co-infection by novel Wolbachia endosymbionts-potential tools for blocking pathogen transmission-these oddities highlight a unique and underappreciated disease vector.}, }
@article {pmid32559249, year = {2020}, author = {Bagnaresi, P and Cattivelli, L}, title = {Ab initio GO-based mining for non-tandem-duplicated functional clusters in three model plant diploid genomes.}, journal = {PloS one}, volume = {15}, number = {6}, pages = {e0234782}, pmid = {32559249}, issn = {1932-6203}, mesh = {Arabidopsis/*genetics ; Databases, Genetic ; Diploidy ; Gene Duplication ; *Gene Ontology ; *Genome, Plant ; Multigene Family ; Oryza/*genetics ; Plant Proteins/genetics ; Signal Transduction ; Vitis/*genetics ; }, abstract = {A functional Non-Tandem Duplicated Cluster (FNTDC) is a group of non-tandem-duplicated genes that are located closer than expected by mere chance and have a role in the same biological function. The identification of secondary-compounds-related FNTDC has gained increased interest in recent years, but little ab-initio attempts aiming to the identification of FNTDCs covering all biological functions, including primary metabolism compounds, have been carried out. We report an extensive FNTDC dataset accompanied by a detailed assessment on parameters used for genome scanning and their impact on FNTDC detection. We propose 70% identity and 70% alignment coverage as intermediate settings to exclude tandem duplicated genes and a dynamic scanning window of 24 genes. These settings were applied to rice, arabidopsis and grapevine genomes to call for FNTDCs. Besides the best-known secondary metabolism clusters, we identified many FNTDCs associated to primary metabolism ranging from macromolecules synthesis/editing, TOR signalling, ubiquitination, proton and electron transfer complexes. Using the intermediate FNTDC setting parameters (at P-value 1e-6), 130, 70 and 140 candidate FNTDCs were called in rice, arabidopsis and grapevine, respectively, and 20 to 30% of GO tags associated to called FNTDC were common among the 3 genomes. The datasets developed along with this work provide a rich framework for pinpointing candidate FNTDCs reflecting all GO-BP tags covering both primary and secondary metabolism with large macromolecular complexes/metabolons as the most represented FNTDCs. Noteworthy, several FNTDCs are tagged with GOs referring to organelle-targeted multi-enzyme complex, a finding that suggest the migration of endosymbiont gene chunks towards nuclei could be at the basis of these class of candidate FNTDCs. Most FNTDC appear to have evolved prior of genome duplication events. More than one-third of genes interspersed/adjacent to called FNTDCs lacked any functional annotation; however, their co-localization may provide hints towards a candidate biological role.}, }
@article {pmid32555677, year = {2020}, author = {Bhattacharya, T and Newton, ILG and Hardy, RW}, title = {Viral RNA is a target for Wolbachia-mediated pathogen blocking.}, journal = {PLoS pathogens}, volume = {16}, number = {6}, pages = {e1008513}, pmid = {32555677}, issn = {1553-7374}, support = {R01 AI144430/AI/NIAID NIH HHS/United States ; R21 AI121849/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes ; Animals ; Cell Line ; Chlorocebus aethiops ; Cricetinae ; Drosophila melanogaster ; Flavivirus/genetics/*metabolism ; RNA, Viral/genetics/*metabolism ; Togaviridae/genetics/*metabolism ; Vero Cells ; Wolbachia/genetics/*metabolism ; }, abstract = {The ability of the endosymbiont Wolbachia pipientis to restrict RNA viruses is presently being leveraged to curb global transmission of arbovirus-induced diseases. Past studies have shown that virus replication is limited early in arthropod cells colonized by the bacterium, although it is unclear if this phenomenon is replicated in mosquito cells that first encounter viruses obtained through a vertebrate blood meal. Furthermore, these cellular events neither explain how Wolbachia limits dissemination of viruses between mosquito tissues, nor how it prevents transmission of infectious viruses from mosquitoes to vertebrate host. In this study, we try to address these issues using an array of mosquito cell culture models, with an additional goal being to identify a common viral target for pathogen blocking. Our results establish the viral RNA as a cellular target for Wolbachia-mediated inhibition, with the incoming viral RNA experiencing rapid turnover following internalization in cells. This early block in replication in mosquito cells initially infected by the virus thus consequently reduces the production of progeny viruses from these same cells. However, this is not the only contributor to pathogen blocking. We show that the presence of Wolbachia reduces the per-particle infectivity of progeny viruses on naïve mosquito and vertebrate cells, consequently limiting virus dissemination and transmission, respectively. Importantly, we demonstrate that this aspect of pathogen blocking is independent of any particular Wolbachia-host association and affects viruses belonging to Togaviridae and Flaviviridae families of RNA viruses. Finally, consistent with the idea of the viral RNA as a target, we find that the encapsidated virion RNA is less infectious for viruses produced from Wolbachia-colonized cells. Collectively, our findings present a common mechanism of pathogen blocking in mosquitoes that establish a link between virus inhibition in the cell to virus dissemination and transmission.}, }
@article {pmid32555454, year = {2020}, author = {Hu, M and Zheng, X and Fan, CM and Zheng, Y}, title = {Lineage dynamics of the endosymbiotic cell type in the soft coral Xenia.}, journal = {Nature}, volume = {582}, number = {7813}, pages = {534-538}, pmid = {32555454}, issn = {1476-4687}, support = {R01 AR060042/AR/NIAMS NIH HHS/United States ; R01 AR071976/AR/NIAMS NIH HHS/United States ; R01 GM106023/GM/NIGMS NIH HHS/United States ; R01 GM110151/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Anthozoa/*cytology/*genetics/immunology/metabolism ; Carbon/metabolism ; Cell Differentiation/genetics ; Cell Lineage/*genetics ; Coral Reefs ; Dinoflagellida/immunology/*metabolism/physiology ; Ecosystem ; Endocytosis ; Genome/genetics ; Phagocytosis ; Photosynthesis ; RNA-Seq ; Single-Cell Analysis ; Symbiosis/*genetics/immunology ; Transcriptome ; }, abstract = {Many corals harbour symbiotic dinoflagellate algae. The algae live inside coral cells in a specialized membrane compartment known as the symbiosome, which shares the photosynthetically fixed carbon with coral host cells while host cells provide inorganic carbon to the algae for photosynthesis[1]. This endosymbiosis-which is critical for the maintenance of coral reef ecosystems-is increasingly threatened by environmental stressors that lead to coral bleaching (that is, the disruption of endosymbiosis), which in turn leads to coral death and the degradation of marine ecosystems[2]. The molecular pathways that orchestrate the recognition, uptake and maintenance of algae in coral cells remain poorly understood. Here we report the chromosome-level genome assembly of a Xenia species of fast-growing soft coral[3], and use this species as a model to investigate coral-alga endosymbiosis. Single-cell RNA sequencing identified 16 cell clusters, including gastrodermal cells and cnidocytes, in Xenia sp. We identified the endosymbiotic cell type, which expresses a distinct set of genes that are implicated in the recognition, phagocytosis and/or endocytosis, and maintenance of algae, as well as in the immune modulation of host coral cells. By coupling Xenia sp. regeneration and single-cell RNA sequencing, we observed a dynamic lineage progression of the endosymbiotic cells. The conserved genes associated with endosymbiosis that are reported here may help to reveal common principles by which different corals take up or lose their endosymbionts.}, }
@article {pmid32547306, year = {2020}, author = {Valle, LG and Stoianova, D}, title = {First record of Harpellales, Orphellales (Kickxellomycotina) and Amoebidiales (Mesomycetozoea) from Bulgaria, including a new species of Glotzia.}, journal = {MycoKeys}, volume = {67}, number = {}, pages = {55-80}, pmid = {32547306}, issn = {1314-4049}, abstract = {This paper presents the results obtained from a short survey performed in Bulgaria, southeast Europe, where the trichomycetes (sensu lato), an ecological group of arthropod gut endosymbionts, were previously completely unknown. The present study initiates the comprehension of these cryptic organisms, members of the Kickxellomycotina (Harpellales, Orphellales) and the Mesomycetozoea (Amoebidiales), in this Balkan country. Eighteen new geographic records for Bulgaria are reported, including 10 species of Harpellales, three species of Orphellales and five species of Amoebidiales. Within the Harpellales, the species Glotzia balkanensis sp. nov. is described. This new species is most related to the rare species G. centroptili Gauthier ex Manier &amp; Lichtw. and G. stenospora White &amp; Lichtw., but is differentiated by spore and thallial characteristics. Photographs are provided and biogeographic implications of these records are discussed.}, }
@article {pmid32546745, year = {2020}, author = {Pirritano, M and Zaburannyi, N and Grosser, K and Gasparoni, G and Müller, R and Simon, M and Schrallhammer, M}, title = {Dual-Seq reveals genome and transcriptome of Caedibacter taeniospiralis, obligate endosymbiont of Paramecium.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {9727}, pmid = {32546745}, issn = {2045-2322}, mesh = {Animals ; Bacteria/genetics ; Evolution, Molecular ; Gammaproteobacteria/*genetics/pathogenicity ; Genome, Bacterial/genetics ; Paramecium/genetics/*microbiology ; Phenotype ; Phylogeny ; Symbiosis/*genetics/physiology ; Transcriptome ; }, abstract = {Interest in host-symbiont interactions is continuously increasing, not only due to the growing recognition of the importance of microbiomes. Starting with the detection and description of novel symbionts, attention moves to the molecular consequences and innovations of symbioses. However, molecular analysis requires genomic data which is difficult to obtain from obligate intracellular and uncultivated bacteria. We report the identification of the Caedibacter genome, an obligate symbiont of the ciliate Paramecium. The infection does not only confer the host with the ability to kill other cells but also renders them immune against this effect. We obtained the C. taeniospiralis genome and transcriptome by dual-Seq of DNA and RNA from infected paramecia. Comparison of codon usage and expression level indicates that genes necessary for a specific trait of this symbiosis, i.e. the delivery of an unknown toxin, result from horizontal gene transfer hinting to the relevance of DNA transfer for acquiring new characters. Prediction of secreted proteins of Caedibacter as major agents of contact with the host implies, next to several toxin candidates, a rather uncharacterized secretome which appears to be highly adapted to this symbiosis. Our data provides new insights into the molecular establishment and evolution of this obligate symbiosis and for the pathway characterization of toxicity and immunity.}, }
@article {pmid32544473, year = {2020}, author = {Ng, KT and Tay, HW and Namkabir, S and Kovilpillai, FJ}, title = {An Unwanted Kiss by Charlie Beetle: An Unusual Case Report.}, journal = {Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons}, volume = {78}, number = {10}, pages = {1766-1769}, doi = {10.1016/j.joms.2020.05.013}, pmid = {32544473}, issn = {1531-5053}, mesh = {Adult ; Animals ; Anti-Bacterial Agents ; Bacteria ; *Coleoptera ; Humans ; Male ; Skin ; *Toxins, Biological ; Young Adult ; }, abstract = {Pederin, a vesicant chemical and one of the most powerful animal toxins in the world, is produced by an endosymbiont bacteria (Pseudomonas spp) found on the beetle Paederus fuscipes. This small, red- and black-striped beetle is also commonly known as the Charlie or rove beetle. Accidental contact with skin causes Paederus dermatitis, with the clinical presentation ranging from mild dermatitis to more severe vesiculobullous lesions. We report a rare case of severe lip destruction caused by the Charlie beetle in a 24-year-old man. Treatment involved intravenous antibiotics in addition to local wound debridement. The thinner stratum corneum on the lips and close proximity to the oral cavity could have resulted in the severe tissue destruction encountered.}, }
@article {pmid32543366, year = {2020}, author = {Hall, RJ and Thorpe, S and Thomas, GH and Wood, AJ}, title = {Simulating the evolutionary trajectories of metabolic pathways for insect symbionts in the genus Sodalis.}, journal = {Microbial genomics}, volume = {6}, number = {7}, pages = {}, pmid = {32543366}, issn = {2057-5858}, support = {BB/M011151/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; WT095024MA/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Adaptation, Physiological ; Algorithms ; Animals ; Bacterial Proteins/genetics ; Computational Biology/*methods ; Enterobacteriaceae/*physiology ; Evolution, Molecular ; Metabolic Networks and Pathways ; Models, Theoretical ; Mutation ; Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Insect-bacterial symbioses are ubiquitous, but there is still much to uncover about how these relationships establish, persist and evolve. The tsetse endosymbiont Sodalis glossinidius displays intriguing metabolic adaptations to its microenvironment, but the process by which this relationship evolved remains to be elucidated. The recent chance discovery of the free-living species of the genus Sodalis, Sodalis praecaptivus, provides a serendipitous starting point from which to investigate the evolution of this symbiosis. Here, we present a flux balance model for S. praecaptivus and empirically verify its predictions. Metabolic modelling is used in combination with a multi-objective evolutionary algorithm to explore the trajectories that S. glossinidius may have undertaken from this starting point after becoming internalized. The order in which key genes are lost is shown to influence the evolved populations, providing possible targets for future in vitro genetic manipulation. This method provides a detailed perspective on possible evolutionary trajectories for S. glossinidius in this fundamental process of evolutionary and ecological change.}, }
@article {pmid32535971, year = {2020}, author = {Pierangelini, M and Thiry, M and Cardol, P}, title = {Different levels of energetic coupling between photosynthesis and respiration do not determine the occurrence of adaptive responses of Symbiodiniaceae to global warming.}, journal = {The New phytologist}, volume = {228}, number = {3}, pages = {855-868}, pmid = {32535971}, issn = {1469-8137}, mesh = {Animals ; *Anthozoa ; *Global Warming ; Oceans and Seas ; Photosynthesis ; Respiration ; Symbiosis ; Temperature ; }, abstract = {Disentangling the metabolic functioning of corals' endosymbionts (Symbiodiniaceae) is relevant to understanding the response of coral reefs to warming oceans. In this work, we first question whether there is an energetic coupling between photosynthesis and respiration in Symbiodiniaceae (Symbiodinium, Durusdinium and Effrenium), and second, how different levels of energetic coupling will affect their adaptive responses to global warming. Coupling between photosynthesis and respiration was established by determining the variation of metabolic rates during thermal response curves, and how inhibition of respiration affects photosynthesis. Adaptive (irreversible) responses were studied by exposing two Symbiodinium species with different levels of photosynthesis-respiration interaction to high temperature conditions (32°C) for 1 yr. We found that some Symbiodiniaceae have a high level of energetic coupling; that is, photosynthesis and respiration have the same temperature dependency, and photosynthesis is negatively affected when respiration is inhibited. Conversely, photosynthesis and respiration are not coupled in other species. In any case, prolonged exposure to high temperature caused adjustments in both photosynthesis and respiration, but these changes were fully reversible. We conclude that energetic coupling between photosynthesis and respiration exhibits wide variation amongst Symbiodiniaceae and does not determine the occurrence of adaptive responses in Symbiodiniaceae to temperature increase.}, }
@article {pmid32525589, year = {2020}, author = {Cornwell, BH}, title = {Gene flow in the anemone Anthopleura elegantissima limits signatures of local adaptation across an extensive geographic range.}, journal = {Molecular ecology}, volume = {29}, number = {14}, pages = {2550-2566}, doi = {10.1111/mec.15506}, pmid = {32525589}, issn = {1365-294X}, mesh = {*Adaptation, Physiological ; Animals ; Evolution, Molecular ; *Gene Flow ; *Genetics, Population ; North America ; Pacific Ocean ; *Sea Anemones/genetics ; Symbiosis ; }, abstract = {Species inhabiting marine environments face a wide range of environmental conditions that vary spatially across several orders of magnitude. The selective pressures that these conditions impose on marine organisms, in combination with potentially high rates of gene flow between distant populations, make it difficult to predict the extent to which these populations can locally adapt. Here, I identify how selection and gene flow influence the population genetic structure of the anemone Anthopleura elegantissima along the Pacific coast of North America. Isolation by distance is the dominant pattern across the range of this species, with a genetic break near Pt. Conception, CA. Furthermore, demographic modelling suggests that this species was historically confined to southerly latitudes before expanding northward. Outlier analyses identify 24 loci under selection (out of ~1,100), but the same analysis on simulated genetic data generated using the most likely demographic model erroneously identified the same number of loci under selection, if not more. Taken together, these results suggest that demographic processes are the dominant force shaping population genetic patterns in A. elegantissima along the Pacific coast of North America. I discuss these patterns in terms of the evolutionary history of A. elegantissima, the potential for local adaptation, and their consequences with respect to interactions with the endosymbiont Breviolum muscatinei across their geographic range.}, }
@article {pmid32523601, year = {2020}, author = {Ocampo-Alvarez, H and Meza-Canales, ID and Mateos-Salmón, C and Rios-Jara, E and Rodríguez-Zaragoza, FA and Robles-Murguía, C and Muñoz-Urias, A and Hernández-Herrera, RM and Choix-Ley, FJ and Becerril-Espinosa, A}, title = {Diving Into Reef Ecosystems for Land-Agriculture Solutions: Coral Microbiota Can Alleviate Salt Stress During Germination and Photosynthesis in Terrestrial Plants.}, journal = {Frontiers in plant science}, volume = {11}, number = {}, pages = {648}, pmid = {32523601}, issn = {1664-462X}, abstract = {From their chemical nature to their ecological interactions, coral reef ecosystems have a lot in common with highly productive terrestrial ecosystems. While plants are responsible for primary production in the terrestrial sphere, the photosynthetic endosymbionts of corals are the key producers in reef communities. As in plants, coral microbiota have been suggested to stimulate the growth and physiological performance of the photosynthetic endosymbionts that provide energy sources to the coral. Among them, actinobacteria are some of the most probable candidates. To explore the potential of coral actinobacteria as plant biostimulants, we have analyzed the activity of Salinispora strains isolated from the corals Porites lobata and Porites panamensis, which were identified as Salinispora arenicola by 16S rRNA sequencing. We evaluated the effects of this microorganism on the germination, plant growth, and photosynthetic response of wild tobacco (Nicotiana attenuata) under a saline regime. We identified protective activity of this actinobacteria on seed germination and photosynthetic performance under natural light conditions. Further insights into the possible mechanism showed an endophytic-like symbiosis between N. attenuata roots and S. arenicola and 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity by S. arenicola. We discuss these findings in the context of relevant ecological and physiological responses and biotechnological potential. Overall, our results will contribute to the development of novel biotechnologies to cope with plant growth under saline stress. Our study highlights the importance of understanding marine ecological interactions for the development of novel, strategic, and sustainable agricultural solutions.}, }
@article {pmid32523040, year = {2020}, author = {Oke, AO and Oladigbolu, AA and Kunta, M and Alabi, OJ and Sétamou, M}, title = {First report of the occurrence of Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae), an invasive species in Nigeria, West Africa.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {9418}, pmid = {32523040}, issn = {2045-2322}, mesh = {Africa, Eastern ; Africa, Western ; Animals ; Citrus/*parasitology ; Hemiptera/*genetics ; Insect Vectors/genetics ; *Introduced Species ; Nigeria ; Nymph/genetics ; Plant Diseases/*parasitology ; Real-Time Polymerase Chain Reaction/methods ; Rhizobiaceae/genetics ; }, abstract = {The Asian citrus psyllid (ACP; Diaphorina citri) is the vector of Candidatus Liberibacter asiaticus (CLas) that is associated with the devastating Huanglongbing (HLB; citrus greening disease). This pest of Asian origin has spread into the Americas and more recently into a few countries in East Africa. During recent surveys, suspect ACP adults and nymphs were recorded for the first time infesting citrus trees in southwest Nigeria. Morphological identification and DNA barcoding confirmed the samples to be D. citri. Analysis of the obtained sequences revealed that the ACP recorded in Nigeria clustered with other taxa in the previously identified B1 clade that consists of populations from different continents. The presence of the endosymbionts Ca. Carsonella ruddii and Ca. Profftella armatura in ACP from Nigeria was also confirmed by PCR and Sanger sequencing. The ACP individuals were assayed for the presence of CLaf, CLam and CLas by qPCR, but none of the insects tested positive for any of the Liberibacters. The prolific nature of ACP and the tropical climate prevailing in the citrus-producing areas of Nigeria and other West African countries may favor its rapid spread and population increase, thus posing a grave threat to the sustainability of citriculture in these countries.}, }
@article {pmid32522243, year = {2020}, author = {Madhav, M and Brown, G and Morgan, JAT and Asgari, S and McGraw, EA and James, P}, title = {Transinfection of buffalo flies (Haematobia irritans exigua) with Wolbachia and effect on host biology.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {296}, pmid = {32522243}, issn = {1756-3305}, mesh = {Animals ; Female ; Fertility ; Host Microbial Interactions ; Life Cycle Stages ; Longevity ; Male ; Microinjections ; Muscidae/*microbiology ; Pest Control, Biological/*methods ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: Buffalo flies (Haematobia irritans exigua) (BF) and closely related horn flies (Haematobia irritans irritans) (HF) are invasive haematophagous parasites with significant economic and welfare impacts on cattle production. Wolbachia are intracellular bacteria found widely in insects and currently of much interest for use in novel strategies for the area wide control of insect pests and insect-vectored diseases. In this paper, we report the transinfection of BF towards the development of area-wide controls.<br><br>METHODS: Three stages of BF; embryos, pupae and adult female flies, were injected with different Wolbachia strains (wAlbB, wMel and wMelPop). The success of transinfection and infection dynamics was compared by real-time PCR and FISH and fitness effects were assessed in transinfected flies.<br><br>RESULTS: BF eggs were not easily injected because of their tough outer chorion and embryos were frequently damaged with less than 1% hatch rate of microinjected eggs. No Wolbachia infection was recorded in flies successfully reared from injected eggs. Adult and pupal injection resulted in higher survival rates and somatic and germinal tissue infections, with transmission to the succeeding generations on some occasions. Investigations of infection dynamics in flies from injected pupae confirmed that Wolbachia were actively multiplying in somatic tissues. Ovarian infections were confirmed with wMel and wMelPop in a number of instances, though not with wAlbB. Measurement of fitness traits indicated reduced longevity, decreased and delayed adult emergence, and reduced fecundity in Wolbachia-infected flies compared to mock-injected flies. Effects varied with the Wolbachia strain injected with most marked changes seen in the wMelPop-injected flies and least severe effects seen with wAlbB.<br><br>CONCLUSIONS: Adult and pupal injection were the most suitable methods for transinfecting BF and all three strains of Wolbachia successfully replicated in somatic tissues. The Wolbachia-induced fitness effects seen in transinfected BF suggest potential for use of the wMel or wMelPop strains in Wolbachia-based biocontrol programmes for BF.}, }
@article {pmid32519794, year = {2021}, author = {Bigiotti, G and Sacchetti, P and Pastorelli, R and Lauzon, CR and Belcari, A}, title = {Bacterial symbiosis in Bactrocera oleae, an Achilles' heel for its pest control.}, journal = {Insect science}, volume = {28}, number = {4}, pages = {874-884}, doi = {10.1111/1744-7917.12835}, pmid = {32519794}, issn = {1744-7917}, mesh = {Animals ; *Bacteria/genetics/pathogenicity ; Crops, Agricultural ; Genes, Bacterial ; Host Microbial Interactions/genetics/physiology ; *Olea ; *Pest Control, Biological ; Symbiosis ; Tephritidae/*microbiology ; }, abstract = {Investigations on microbial symbioses in Tephritidae have increased over the past 30 years owing to the potential use of these relationships in developing new control strategies for economically important fruit flies. Bactrocera oleae (Rossi)-the olive fruit fly-is a monophagous species strictly associated with the olive tree, and among all the tephritids, its symbionts are the most investigated. The bacterium Candidatus Erwinia dacicola is the major persistent resident endosymbiont in wild B. oleae populations. Its relationship with B. oleae has been investigated since being identified in 2005. This endosymbiont is vertically transmitted through generations from the female to the egg. It exists at every developmental stage, although it is more abundant in larvae and ovipositing females, and is necessary for both larvae and adults. Studying B. oleae-Ca. E. dacicola, or other B. oleae-microbe interactions, will allow us to develop modern biological control systems for area-wide olive protection and set an example for similar programs in other important food crops. This review summarizes the information available on tephritid-microbe interactions and investigates relationships among fruit flies, bacteria and host plants; however, its focus is on B. oleae and its strict association with Ca. E. dacicola to promote environmentally friendly control strategies for area-wide pest management.}, }
@article {pmid32507278, year = {2020}, author = {Matsumoto, T and Awai, K}, title = {Adaptations in chloroplast membrane lipid synthesis from synthesis in ancestral cyanobacterial endosymbionts.}, journal = {Biochemical and biophysical research communications}, volume = {528}, number = {3}, pages = {473-477}, doi = {10.1016/j.bbrc.2020.05.175}, pmid = {32507278}, issn = {1090-2104}, mesh = {Arabidopsis/genetics/metabolism ; Biosynthetic Pathways ; Chloroplasts/genetics/*metabolism ; Endophytes/genetics/metabolism ; Escherichia coli/genetics/metabolism ; Evolution, Molecular ; Gene Knockout Techniques ; Genes, Bacterial ; Genes, Essential ; Glycerol-3-Phosphate O-Acyltransferase/genetics/metabolism ; Lysophospholipids/biosynthesis ; Membrane Lipids/*biosynthesis ; Symbiosis ; Synechocystis/genetics/*metabolism ; }, abstract = {Cyanobacteria and chloroplasts are believed to share a common ancestor, but synthetic pathways for membrane lipids are different. Lyso-phosphatidic acid (lyso-PA) is the precursor for the synthesis of all membrane lipids and synthesized by an acyl-ACP dependent glycerol-3-phosphate acyltransferase (GPAT) in chloroplasts. In cyanobacteria, GPAT genes are not found and, instead, genes coding for enzymes in the acyl-phosphate dependent lyso-PA synthetic pathway (plsX and plsY) are conserved. We report that the PlsX/Y dependent lyso-PA synthetic pathway is essential in cyanobacteria, but can be replaced by acyl-ACP dependent GPAT from Escherichia coli (plsB) and Arabidopsis thaliana (ATS1). Cyanobacteria thus display the capacity to accept enzymes from other organisms to synthesize essential components. This ability may have enabled them to evolve into current chloroplasts from their ancestral origins.}, }
@article {pmid32503277, year = {2020}, author = {Tal, O and Selvaraj, G and Medina, S and Ofaim, S and Freilich, S}, title = {NetMet: A Network-Based Tool for Predicting Metabolic Capacities of Microbial Species and their Interactions.}, journal = {Microorganisms}, volume = {8}, number = {6}, pages = {}, pmid = {32503277}, issn = {2076-2607}, abstract = {Metabolic conversions allow organisms to produce a set of essential metabolites from the available nutrients in an environment, frequently requiring metabolic exchanges among co-inhabiting organisms. Genomic-based metabolic simulations are being increasingly applied for exploring metabolic capacities, considering different environments and different combinations of microorganisms. NetMet is a web-based tool and a software package for predicting the metabolic performances of microorganisms and their corresponding combinations in user-defined environments. The algorithm takes, as input, lists of (i) species-specific enzymatic reactions (EC numbers), and (ii) relevant metabolic environments. The algorithm generates, as output, lists of (i) compounds that individual species can produce in each given environment, and (ii) compounds that are predicted to be produced through complementary interactions. The tool is demonstrated in two case studies. First, we compared the metabolic capacities of different haplotypes of the obligatory fruit and vegetable pathogen Candidatus Liberibacter solanacearum to those of their culturable taxonomic relative Liberibacter crescens. Second, we demonstrated the potential production of complementary metabolites by pairwise combinations of co-occurring endosymbionts of the plant phloem-feeding whitefly Bemisia tabaci. NetMet, a new web-based tool, is available at https://freilich-lab-tools.com/.}, }
@article {pmid32502919, year = {2020}, author = {Carretón, E and Morchón, R and Falcón-Cordón, Y and Falcón-Cordón, S and Matos, JI and Montoya-Alonso, JA}, title = {Evaluation of different dosages of doxycycline during the adulticide treatment of heartworm (Dirofilaria immitis) in dogs.}, journal = {Veterinary parasitology}, volume = {283}, number = {}, pages = {109141}, doi = {10.1016/j.vetpar.2020.109141}, pmid = {32502919}, issn = {1873-2550}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Antibodies, Bacterial/*blood ; Antinematodal Agents/administration &amp; dosage ; Dirofilariasis/drug therapy/parasitology ; Dog Diseases/drug therapy/parasitology ; Dogs ; Dose-Response Relationship, Drug ; Doxycycline/*pharmacology ; Wolbachia/drug effects/*physiology ; }, abstract = {The endosymbiont bacteria Wolbachia plays an important role in the pathogenesis and inflammatory immune response to heartworm (Dirofilaria immitis) infection in dogs. Doxycycline is used to reduce Wolbachia from all life stages of heartworm to avoid large releases of the bacteria during the death of the worms. However, the dose and duration currently recommended have been extrapolated from the treatment of other rickettsial infections. Therefore, the aim was to study the dynamics of Wolbachia IgG antibodies in heartworm-infected dogs under adulticide treatment using different dosages of doxycycline. Forty-nine heartworm-infected dogs were recruited. On day 0 (diagnosis), monthly ivermectin (6 μg/kg) was prescribed, as well as daily doxycycline for 30 days, at 10 mg/kg/12 h (n = 13), 5 mg/kg/12 h (n = 19), and 10 mg/kg/24 h (n = 17). Dogs underwent adulticide treatment and blood samples were collected on days 0, 30, 90, and 120. All dogs had antibodies against recombinant Wolbachia surface protein (rWSP), confirming the important role of the bacteria in heartworm. No significant differences were found in anti-rWSP response by presence/absence of microfilariae, or by parasite burden on day 0. In all treated groups, the anti-rWSP antibody response was not significantly different between days 0 and 30 but was significantly lower between days 0 and 120 (p < 0.05). The results of the present study suggest that the administration of a lower dose than currently recommended is sufficient to achieve a significant reduction of Wolbachia in dogs infected by D. immitis.}, }
@article {pmid32497084, year = {2020}, author = {McCabe, RA and Receveur, JP and Houtz, JL and Thomas, KL and Benbow, ME and Pechal, JL and Wallace, JR}, title = {Characterizing the microbiome of ectoparasitic louse flies feeding on migratory raptors.}, journal = {PloS one}, volume = {15}, number = {6}, pages = {e0234050}, pmid = {32497084}, issn = {1932-6203}, mesh = {*Animal Migration ; Animals ; Diptera/*microbiology/*physiology ; *Host-Parasite Interactions ; *Microbiota ; Raptors/*parasitology ; }, abstract = {Louse flies (Diptera: Hippoboscidae) are obligate ectoparasites that often cause behavioral, pathogenic, and evolutionary effects on their hosts. Interactions between ectoparasites and avian hosts, especially migrating taxa, may influence avian pathogen spread in tropical and temperate ecosystems and affect long-term survival, fitness and reproductive success. The purpose of this study was to characterize the vector-associated microbiome of ectoparasitic louse flies feeding on migrating raptors over the fall migration period. Surveys for louse flies occurred during fall migration (2015-2016) at a banding station in Pennsylvania, United States; flies were collected from seven species of migrating raptors, and we sequenced their microbial (bacteria and archaea) composition using high-throughput targeted amplicon sequencing of the 16S rRNA gene (V4 region). All louse flies collected belonged to the same species, Icosta americana. Our analysis revealed no difference in bacterial communities of louse flies retrieved from different avian host species. The louse fly microbiome was dominated by a primary endosymbiont, suggesting that louse flies maintain a core microbial structure despite receiving blood meals from different host species. Thus, our findings highlight the importance of characterizing both beneficial and potentially pathogenic endosymbionts when interpreting how vector-associated microbiomes may impact insect vectors and their avian hosts.}, }
@article {pmid32494722, year = {2020}, author = {Singh, KS and Troczka, BJ and Duarte, A and Balabanidou, V and Trissi, N and Carabajal Paladino, LZ and Nguyen, P and Zimmer, CT and Papapostolou, KM and Randall, E and Lueke, B and Marec, F and Mazzoni, E and Williamson, MS and Hayward, A and Nauen, R and Vontas, J and Bass, C}, title = {The genetic architecture of a host shift: An adaptive walk protected an aphid and its endosymbiont from plant chemical defenses.}, journal = {Science advances}, volume = {6}, number = {19}, pages = {eaba1070}, pmid = {32494722}, issn = {2375-2548}, abstract = {Host shifts can lead to ecological speciation and the emergence of new pests and pathogens. However, the mutational events that facilitate the exploitation of novel hosts are poorly understood. Here, we characterize an adaptive walk underpinning the host shift of the aphid Myzus persicae to tobacco, including evolution of mechanisms that overcame tobacco chemical defenses. A series of mutational events added as many as 1.5 million nucleotides to the genome of the tobacco-adapted subspecies, M. p. nicotianae, and yielded profound increases in expression of an enzyme that efficiently detoxifies nicotine, both in aphid gut tissue and in the bacteriocytes housing the obligate aphid symbiont Buchnera aphidicola. This dual evolutionary solution overcame the challenge of preserving fitness of a mutualistic symbiosis during adaptation to a toxic novel host. Our results reveal the intricate processes by which genetic novelty can arise and drive the evolution of key innovations required for ecological adaptation.}, }
@article {pmid32491177, year = {2020}, author = {Adams, M and McBroome, J and Maurer, N and Pepper-Tunick, E and Saremi, NF and Green, RE and Vollmers, C and Corbett-Detig, RB}, title = {One fly-one genome: chromosome-scale genome assembly of a single outbred Drosophila melanogaster.}, journal = {Nucleic acids research}, volume = {48}, number = {13}, pages = {e75}, pmid = {32491177}, issn = {1362-4962}, support = {R35 GM128932/GM/NIGMS NIH HHS/United States ; R35 GM133569/GM/NIGMS NIH HHS/United States ; T32 HG008345/HG/NHGRI NIH HHS/United States ; }, mesh = {Animals ; Chromosomes, Bacterial/*genetics ; Chromosomes, Insect/*genetics ; Drosophila melanogaster/*genetics ; Genome, Bacterial/*genetics ; Genome, Insect/*genetics ; Genomics/methods ; Wolbachia/*genetics ; }, abstract = {A high quality genome assembly is a vital first step for the study of an organism. Recent advances in technology have made the creation of high quality chromosome scale assemblies feasible and low cost. However, the amount of input DNA needed for an assembly project can be a limiting factor for small organisms or precious samples. Here we demonstrate the feasibility of creating a chromosome scale assembly using a hybrid method for a low input sample, a single outbred Drosophila melanogaster. Our approach combines an Illumina shotgun library, Oxford nanopore long reads, and chromosome conformation capture for long range scaffolding. This single fly genome assembly has a N50 of 26 Mb, a length that encompasses entire chromosome arms, contains 95% of expected single copy orthologs, and a nearly complete assembly of this individual's Wolbachia endosymbiont. The methods described here enable the accurate and complete assembly of genomes from small, field collected organisms as well as precious clinical samples.}, }
@article {pmid32490527, year = {2020}, author = {Luévano-Martínez, LA and Duncan, AL}, title = {Origin and diversification of the cardiolipin biosynthetic pathway in the Eukarya domain.}, journal = {Biochemical Society transactions}, volume = {48}, number = {3}, pages = {1035-1046}, doi = {10.1042/BST20190967}, pmid = {32490527}, issn = {1470-8752}, support = {BB/R00126X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Archaea/*enzymology ; Bacteria/*enzymology ; Binding Sites ; Biosynthetic Pathways ; Cardiolipins/*biosynthesis ; Catalysis ; Eukaryota/*enzymology ; Evolution, Molecular ; Gene Transfer, Horizontal ; Hydrolases/metabolism ; Mitochondria/metabolism ; Models, Molecular ; Phosphatidylglycerols/*metabolism ; Phospholipids/metabolism ; Phosphoric Monoester Hydrolases/metabolism ; Phylogeny ; }, abstract = {Cardiolipin (CL) and its precursor phosphatidylglycerol (PG) are important anionic phospholipids widely distributed throughout all domains of life. They have key roles in several cellular processes by shaping membranes and modulating the activity of the proteins inserted into those membranes. They are synthesized by two main pathways, the so-called eukaryotic pathway, exclusively found in mitochondria, and the prokaryotic pathway, present in most bacteria and archaea. In the prokaryotic pathway, the first and the third reactions are catalyzed by phosphatidylglycerol phosphate synthase (Pgps) belonging to the transferase family and cardiolipin synthase (Cls) belonging to the hydrolase family, while in the eukaryotic pathway, those same reactions are catalyzed by unrelated homonymous enzymes: Pgps of the hydrolase family and Cls of the transferase family. Because of the enzymatic arrangement found in both pathways, it seems that the eukaryotic pathway evolved by convergence to the prokaryotic pathway. However, since mitochondria evolved from a bacterial endosymbiont, it would suggest that the eukaryotic pathway arose from the prokaryotic pathway. In this review, it is proposed that the eukaryote pathway evolved directly from a prokaryotic pathway by the neofunctionalization of the bacterial enzymes. Moreover, after the eukaryotic radiation, this pathway was reshaped by horizontal gene transfers or subsequent endosymbiotic processes.}, }
@article {pmid32489617, year = {2020}, author = {Zélé, F and Altıntaş, M and Santos, I and Cakmak, I and Magalhães, S}, title = {Population-specific effect of Wolbachia on the cost of fungal infection in spider mites.}, journal = {Ecology and evolution}, volume = {10}, number = {9}, pages = {3868-3880}, pmid = {32489617}, issn = {2045-7758}, abstract = {Many studies have revealed the ability of the endosymbiotic bacterium Wolbachia to protect its arthropod hosts against diverse pathogens. However, as Wolbachia may also increase the susceptibility of its host to infection, predicting the outcome of a particular Wolbachia-host-pathogen interaction remains elusive. Yet, understanding such interactions and their eco-evolutionary consequences is crucial for disease and pest control strategies. Moreover, how natural Wolbachia infections affect artificially introduced pathogens for biocontrol has never been studied. Tetranychus urticae spider mites are herbivorous crop pests, causing severe damage on numerous economically important crops. Due to the rapid evolution of pesticide resistance, biological control strategies using entomopathogenic fungi are being developed. However, although spider mites are infected with various Wolbachia strains worldwide, whether this endosymbiont protects them from fungi is as yet unknown. Here, we compared the survival of two populations, treated with antibiotics or naturally harboring different Wolbachia strains, after exposure to the fungal biocontrol agents Metarhizium brunneum and Beauveria bassiana. To control for potential effects of the bacterial community of spider mites, we also compared the susceptibility of two populations naturally uninfected by Wolbachia, treated with antibiotics or not. In one population, Wolbachia-infected mites had a better survival than uninfected ones in absence of fungi but not in their presence, whereas in the other population Wolbachia increased the mortality induced by B. bassiana. In one naturally Wolbachia-uninfected population, the antibiotic treatment increased the susceptibility of spider mites to M. brunneum, but it had no effect in the other treatments. These results suggest that natural Wolbachia infections may not hamper and may even improve the success of biological control using entomopathogenic fungi. However, they also draw caution on the generalization of such effects, given the complexity of within-host-pathogens interaction and the potential eco-evolutionary consequences of the use of biocontrol agents for Wolbachia-host associations.}, }
@article {pmid32489610, year = {2020}, author = {Detcharoen, M and Arthofer, W and Jiggins, FM and Steiner, FM and Schlick-Steiner, BC}, title = {Wolbachia affect behavior and possibly reproductive compatibility but not thermoresistance, fecundity, and morphology in a novel transinfected host, Drosophila nigrosparsa.}, journal = {Ecology and evolution}, volume = {10}, number = {10}, pages = {4457-4470}, pmid = {32489610}, issn = {2045-7758}, abstract = {Wolbachia, intracellular endosymbionts, are estimated to infect about half of all arthropod species. These bacteria manipulate their hosts in various ways for their maximum benefits. The rising global temperature may accelerate species migration, and thus, horizontal transfer of Wolbachia may occur across species previously not in contact. We transinfected and then cured the alpine fly Drosophila nigrosparsa with Wolbachia strain wMel to study its effects on this species. We found low Wolbachia titer, possibly cytoplasmic incompatibility, and an increase in locomotion of both infected larvae and adults compared with cured ones. However, no change in fecundity, no impact on heat and cold tolerance, and no change in wing morphology were observed. Although Wolbachia increased locomotor activities in this species, we conclude that D. nigrosparsa may not benefit from the infection. Still, D. nigrosparsa can serve as a host for Wolbachia because vertical transmission is possible but may not be as high as in the native host of wMel, Drosophila melanogaster.}, }
@article {pmid32489376, year = {2020}, author = {Khanmohammadi, M and Akhlaghi, L and Razmjou, E and Falak, R and Zolfaghari Emameh, R and Mokhtarian, K and Arshadi, M and Tasbihi, M and Meamar, AR}, title = {Morphological Description, Phylogenetic and Molecular Analysis of Dirofilaria immitis Isolated from Dogs in the Northwest of Iran.}, journal = {Iranian journal of parasitology}, volume = {15}, number = {1}, pages = {57-66}, pmid = {32489376}, issn = {1735-7020}, abstract = {BACKGROUND: Dirofilariasis is a globally distributed arthropod-borne parasitic disease of mainly canids and felids. We evaluated to extend the knowledge of morpho-molecular characteristics and outer ultrastructure of Dirofilaria immitis isolated from Northwest of Iran.<br><br>METHODS: Overall, 67 filarial worms including 41 females and 26 males parasites were collected from the cardiovascular system of the 43 stray dogs in Meshkinshar, Ardebil Province, Northwest of Iran in 2017, and subjected to light and scanning electron microscopy (SEM) as well as carmine alum staining for morpho-molecular and identification. Molecular methods were used for confirmation of morphological findings by sequencing of Cyto-chrome c oxidase subunit I (cox1) gene.<br><br>RESULTS: The partial DNA sequencing of cox1 gene of adult parasites showed considerable homology and close proximity to the previously isolated from Kerman and Meshkinshahr, Iran. The lowest genetic variation and the highest intra-species variability was found in D. immitis and Dirofilaria repens, respectively. No similarity was identified between D. immitis nucleotide sequence and Wolbachia species as its endosymbiont bacteria.<br><br>CONCLUSION: The SEM technique is an excellent tool for differential recognition of the parasite surface morphology and molecular techniques could differentiate and identify Dirofilaria spp.}, }
@article {pmid32477411, year = {2020}, author = {Mazzucco, R and Nolte, V and Vijayan, T and Schlötterer, C}, title = {Long-Term Dynamics Among Wolbachia Strains During Thermal Adaptation of Their Drosophila melanogaster Hosts.}, journal = {Frontiers in genetics}, volume = {11}, number = {}, pages = {482}, pmid = {32477411}, issn = {1664-8021}, support = {P 27630/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Climate change is a major evolutionary force triggering thermal adaptation in a broad range of species. While the consequences of global warming are being studied for an increasing number of species, limited attention has been given to the evolutionary dynamics of endosymbionts in response to climate change. Here, we address this question by studying the dynamics of Wolbachia, a well-studied endosymbiont of Drosophila melanogaster. D. melanogaster populations infected with 13 different Wolbachia strains were exposed to novel hot and cold laboratory environments for up to 180 generations. The short-term dynamics suggested a temperature-related fitness difference resulting in the increase of clade V strains in the cold environment only. Our long-term analysis now uncovers that clade V dominates in all replicates after generation 60 irrespective of temperature treatment. We propose that adaptation of the Drosophila host to either temperature or Drosophila C virus (DCV) infection are the cause of the replicated, temporally non-concordant Wolbachia dynamics. Our study provides an interesting case demonstrating that even simple, well-controlled experiments can result in complex, but repeatable evolutionary dynamics, thus providing a cautionary note on too simple interpretations on the impact of climate change.}, }
@article {pmid32471448, year = {2020}, author = {Dennis, AB and Ballesteros, GI and Robin, S and Schrader, L and Bast, J and Berghöfer, J and Beukeboom, LW and Belghazi, M and Bretaudeau, A and Buellesbach, J and Cash, E and Colinet, D and Dumas, Z and Errbii, M and Falabella, P and Gatti, JL and Geuverink, E and Gibson, JD and Hertaeg, C and Hartmann, S and Jacquin-Joly, E and Lammers, M and Lavandero, BI and Lindenbaum, I and Massardier-Galata, L and Meslin, C and Montagné, N and Pak, N and Poirié, M and Salvia, R and Smith, CR and Tagu, D and Tares, S and Vogel, H and Schwander, T and Simon, JC and Figueroa, CC and Vorburger, C and Legeai, F and Gadau, J}, title = {Functional insights from the GC-poor genomes of two aphid parasitoids, Aphidius ervi and Lysiphlebus fabarum.}, journal = {BMC genomics}, volume = {21}, number = {1}, pages = {376}, pmid = {32471448}, issn = {1471-2164}, mesh = {Animals ; Aphids/*genetics/immunology ; DNA Methylation/genetics ; GC Rich Sequence ; *Genomics ; Insect Proteins/genetics ; Sex Determination Processes/genetics ; Venoms/genetics ; Wasps/*genetics/immunology ; }, abstract = {BACKGROUND: Parasitoid wasps have fascinating life cycles and play an important role in trophic networks, yet little is known about their genome content and function. Parasitoids that infect aphids are an important group with the potential for biological control. Their success depends on adapting to develop inside aphids and overcoming both host aphid defenses and their protective endosymbionts.<br><br>RESULTS: We present the de novo genome assemblies, detailed annotation, and comparative analysis of two closely related parasitoid wasps that target pest aphids: Aphidius ervi and Lysiphlebus fabarum (Hymenoptera: Braconidae: Aphidiinae). The genomes are small (139 and 141 Mbp) and the most AT-rich reported thus far for any arthropod (GC content: 25.8 and 23.8%). This nucleotide bias is accompanied by skewed codon usage and is stronger in genes with adult-biased expression. AT-richness may be the consequence of reduced genome size, a near absence of DNA methylation, and energy efficiency. We identify missing desaturase genes, whose absence may underlie mimicry in the cuticular hydrocarbon profile of L. fabarum. We highlight key gene groups including those underlying venom composition, chemosensory perception, and sex determination, as well as potential losses in immune pathway genes.<br><br>CONCLUSIONS: These findings are of fundamental interest for insect evolution and biological control applications. They provide a strong foundation for further functional studies into coevolution between parasitoids and their hosts. Both genomes are available at https://bipaa.genouest.org.}, }
@article {pmid32470630, year = {2020}, author = {Shah, SHJ and Malik, AH and Zhang, B and Bao, Y and Qazi, J}, title = {Metagenomic analysis of relative abundance and diversity of bacterial microbiota in Bemisia tabaci infesting cotton crop in Pakistan.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {84}, number = {}, pages = {104381}, doi = {10.1016/j.meegid.2020.104381}, pmid = {32470630}, issn = {1567-7257}, mesh = {Animals ; Bacteria/*genetics/*isolation &amp; purification ; Genetic Variation ; Genome, Bacterial ; Genomics/*methods ; Gossypium/*parasitology ; Hemiptera/*microbiology ; *Metagenome ; Pakistan ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; }, abstract = {B. tabaci species complex are among the world's most devastating agricultural pests causing economic losses by direct feeding and more importantly by transmitting plant viruses like cotton leaf curl disease (CLCuD) associated viruses to cultivated cotton in Pakistan. Taxonomic diversity of B. tabaci associated bacterial communities using NGS techniques so far is reported from insects grown on artificial diet under lab conditions. In this study 16S rDNA metagenome sequencing analysis was used to characterize bacterial compositions in wild adult B. tabaci infesting cultivated cotton in eight major cotton growing districts of southern Punjab, Pakistan. We have identified 50 known and 7 unknown genera of bacteria belonging to 10 phyla, 20 classes, 30 orders and 40 families. Beta diversity analysis of our data sets reveal that whiteflies infesting cotton in geographically distinct locations had similar bacterial diversity. These results for the first time provide insights into the microbiome diversity of wild type whiteflies infesting a cultivated crop.}, }
@article {pmid32457850, year = {2020}, author = {Guizzo, MG and Neupane, S and Kucera, M and Perner, J and Frantová, H and da Silva Vaz, I and de Oliveira, PL and Kopacek, P and Zurek, L}, title = {Poor Unstable Midgut Microbiome of Hard Ticks Contrasts With Abundant and Stable Monospecific Microbiome in Ovaries.}, journal = {Frontiers in cellular and infection microbiology}, volume = {10}, number = {}, pages = {211}, pmid = {32457850}, issn = {2235-2988}, mesh = {Animals ; Female ; Humans ; *Ixodes ; *Ixodidae ; *Microbiota ; Ovary ; *Rhipicephalus ; }, abstract = {Culture-independent metagenomic methodologies have enabled detection and identification of microorganisms in various biological systems and often revealed complex and unknown microbiomes. In many organisms, the microbiome outnumbers the host cells and greatly affects the host biology and fitness. Ticks are hematophagous ectoparasites with a wide host range. They vector a number of human and animal pathogens and also directly cause major economic losses in livestock. Although several reports on a tick midgut microbiota show a diverse bacterial community, in most cases the size of the bacterial population has not been determined. In this study, the microbiome was quantified in the midgut and ovaries of the ticks Ixodes ricinus and Rhipicephalus microplus before, during, and after blood feeding. Although the size of bacterial community in the midgut fluctuated with blood feeding, it was overall extremely low in comparison to that of other hematophagous arthropods. In addition, the tick ovarian microbiome of both tick species exceeded the midgut 16S rDNA copy numbers by several orders of magnitude. This indicates that the ratio of a tick midgut/ovary microbiome represents an exception to the general biology of other metazoans. In addition to the very low abundance, the tick midgut diversity in I. ricinus was variable and that is in contrast to that found in the tick ovary. The ovary of I. ricinus had a very low bacterial diversity and a very high and stable bacterial abundance with the dominant endosymbiont, Midichloria sp. The elucidation of this aspect of tick biology highlights a unique tissue-specific microbial-invertebrate host interaction.}, }
@article {pmid32455576, year = {2020}, author = {Laidoudi, Y and Marie, JL and Tahir, D and Watier-Grillot, S and Mediannikov, O and Davoust, B}, title = {Detection of Canine Vector-Borne Filariasis and Their Wolbachia Endosymbionts in French Guiana.}, journal = {Microorganisms}, volume = {8}, number = {5}, pages = {}, pmid = {32455576}, issn = {2076-2607}, abstract = {In French Guiana, canine heartworm disease is well known, but the diversity of filarial parasites of dogs remains largely unknown. A total of 98 canine blood samples from Cayenne and Kourou were assessed by a blood wet mount preparation, heartworm antigen test and molecular exploration of filarioid and Wolbachia DNAs, followed by a multiplex species-specific qPCR's identification and a subsequent sequencing analysis. Thereafter, a phylogeny based on maximum likelihood was carried out to facilitate specific identification. Five dogs were microfilaremic. Heartworm antigens were detected in 15 (15.3%) dogs. Of these, six (6.1%) were considered as occult infections as neither microfilariae nor Dirofilaria immitis DNA were detected. The 11 (11.2%) D. immitis isolates corresponded to a low virulent strain. Six of the D. immitis isolates were positive for Wolbachia endosymbionts of D. immitis belonging to the clade C DNA. Acanthocheilonema reconditum DNA was detected in 3 (3.1%) samples. Of these latter, one was found co-infected with the Brugia sp. genotype and the DNA of the clade D of the Wolbachia endosymbiont of Brugia species. This latter was also detected in two filarioid DNA-free samples. Finally, two samples were positive for Cercopithifilaria bainae genotype, which is distinct from those identified in Europe. The present study highlights the urgent need to implement chemoprophylaxis associated with anti-Wolbachia drugs to control these potential zoonoses.}, }
@article {pmid32448525, year = {2020}, author = {Li, J and Kelly, P and Guo, W and Zhang, J and Yang, Y and Liu, W and Wang, C}, title = {Molecular detection of Rickettsia, Hepatozoon, Ehrlichia and SFTSV in goat ticks.}, journal = {Veterinary parasitology, regional studies and reports}, volume = {20}, number = {}, pages = {100407}, doi = {10.1016/j.vprsr.2020.100407}, pmid = {32448525}, issn = {2405-9390}, mesh = {Animals ; China ; Ehrlichia/*isolation &amp; purification ; Eucoccidiida/*isolation &amp; purification ; Goats/parasitology ; Phlebovirus/*isolation &amp; purification ; Rickettsia/*isolation &amp; purification ; Species Specificity ; Ticks/*microbiology/*parasitology/virology ; }, abstract = {Ticks are vectors of various pathogens to people, livestock, companion animals and wildlife. We describe here the ticks found on goats in Anhui province of China and the results of molecular studies on six tick-borne pathogens they might harbor. Among 125 ticks collected (119 Haemaphysalis longicornis, n = 119; Rhipicephalus microplus, n = 6), we detected four of the six tick-borne agents for which we tested. In total, 16.8% of the H. longicornis were positive for Candidatus Rickettsia longicornii (18/119), Rickettsia endosymbiont of Leptocybe invasa (1/119) and Rickettsia sibirica (1/119). Hepatozoon canis was positive for 41.6% of the ticks (H. longicornis 42.0%, 50/119; R. microplus 12.5%, 2/6). Only 5.6% of the ticks were positive for Ehrlichia (H. longicornis 5.0%, 6/119; R. microplus 16.7%, 1/6). The Severe Fever with Thrombocytopenia Syndrome Virus was only identified in one H. longicornis. Such data is important in developing effective, integrated and strategic control measures for ticks and the pathogens they transmit.}, }
@article {pmid32444468, year = {2020}, author = {Masson, F and Schüpfer, F and Jollivet, C and Lemaitre, B}, title = {Transformation of the Drosophila Sex-Manipulative Endosymbiont Spiroplasma poulsonii and Persisting Hurdles for Functional Genetic Studies.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {14}, pages = {}, pmid = {32444468}, issn = {1098-5336}, mesh = {Animals ; Drosophila melanogaster/*microbiology/*physiology ; Female ; Male ; Reproduction ; Spiroplasma/*genetics ; *Symbiosis ; *Transformation, Bacterial ; }, abstract = {Insects are frequently infected by bacterial symbionts that greatly affect their physiology and ecology. Most of these endosymbionts are, however, barely tractable outside their native host, rendering functional genetics studies difficult or impossible. Spiroplasma poulsonii is a facultative bacterial endosymbiont of Drosophila melanogaster that manipulates the reproduction of its host by killing its male progeny at the embryonic stage. S. poulsonii, although a very fastidious bacterium, is closely related to pathogenic Spiroplasma species that are cultivable and genetically modifiable. In this work, we present the transformation of S. poulsonii with a plasmid bearing a fluorescence cassette, leveraging techniques adapted from those used to modify the pathogenic species Spiroplasma citri We demonstrate the feasibility of S. poulsonii transformation and discuss approaches for mutant selection and fly colonization, which are persisting hurdles that must be overcome to allow functional bacterial genetics studies of this endosymbiont in vivoIMPORTANCE Dozens of bacterial endosymbiont species have been described and estimated to infect about half of all insect species. However, only a few them are tractable in vitro, which hampers our understanding of the bacterial determinants of the host-symbiont interaction. Developing a transformation method for S. poulsonii is a major step toward genomic engineering of this symbiont, which will foster basic research on endosymbiosis. This could also open the way to practical uses of endosymbiont engineering through paratransgenesis of vector or pest insects.}, }
@article {pmid32443976, year = {2020}, author = {Manzano-Marín, A}, title = {No evidence for Wolbachia as a nutritional co-obligate endosymbiont in the aphid Pentalonia nigronervosa.}, journal = {Microbiome}, volume = {8}, number = {1}, pages = {72}, pmid = {32443976}, issn = {2049-2618}, mesh = {Animals ; *Aphids ; *Buchnera/genetics ; Hemolymph ; Symbiosis ; *Wolbachia ; }, abstract = {Obligate symbiotic associations are present in a wide variety of animals with a nutrient-restricted diet. Aphids (hemiptera: Aphididae) almost-universally host Buchnera aphidicola bacteria in specialised organs (called bacteriomes). These bacteria supply the aphid with essential nutrients lacking from their diet (i.e. essential amino acids and some B vitamins). Some aphid lineages, such as species from the Lacninae subfamily, have evolved co-obligate associations with secondary endosymbionts, deriving from a loss of biotin- and riboflavin-biosynthetic genes. In this study, I re-analyse previously published sequencing data from the banana aphid Pentalonia nigronervosa. I show that the metabolic inference results from De Clerck et al. (Microbiome 3:63, 2015) are incorrect and possibly arise from the use of inadequate methods. Additionally, I discuss how the seemingly biased interpretation of their antibiotic treatment analyses together with an incorrect genome-based metabolic inference resulted in the erroneous suggestion "that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid".}, }
@article {pmid32436345, year = {2020}, author = {Goñi, P and Benito, M and LaPlante, D and Fernández, MT and Sánchez, E and Chueca, P and Miguel, N and Mosteo, R and Ormad, MP and Rubio, E}, title = {Identification of free-living amoebas and amoeba-resistant bacteria accumulated in Dreissena polymorpha.}, journal = {Environmental microbiology}, volume = {22}, number = {8}, pages = {3315-3324}, doi = {10.1111/1462-2920.15093}, pmid = {32436345}, issn = {1462-2920}, support = {B43_20R//Gobierno de Arag&#xf3;n/International ; //Feder 2014-2020 'Building Europe from Arag&#xf3;n'/International ; }, mesh = {Amoeba/classification/*isolation &amp; purification ; Animals ; Bacteria/classification/*isolation &amp; purification ; Cryptosporidium/*isolation &amp; purification ; Dreissena/*microbiology/*parasitology ; Giardia/*isolation &amp; purification ; Rivers/microbiology/parasitology ; Spain ; }, abstract = {To identify the free-living amoeba (FLA) and amoeba-resistant bacteria (ARB) accumulated in zebra mussels and in the water in which they are found, mussels were collected at two locations in the Ebro river basin (North East Spain). FLAs and bacteria were isolated from mussel extracts and from natural water. PCR techniques were used to identify the FLAs and endosymbiont bacteria (Legionella, Mycobacterium, Pseudomonas and cyanobacteria), and to detect Giardia and Cryptosporidium. The most frequently found FLAs were Naegleria spp. The presence of Legionella, Mycobacterium and Pseudomonas inside the FLA was demonstrated, and in some cases both Legionella and Pseudomonas were found together. Differences between FLAs and ARB identified inside the mussels and in the water were detected. In addition, Escherichia coli, Clostridium perfringens, Salmonella spp. and Enterococcus spp. were accumulated in mussels in concentrations unconnected with those found in water. The results show the ability of the zebra mussel to act as a reservoir of potentially pathogenic FLAs, which are associated with potentially pathogenic ARB, although the lack of association between microorganisms inside the mussels and in the water suggests that they are not useful for monitoring microbiological contamination at a specific time.}, }
@article {pmid32428484, year = {2020}, author = {Lane, N}, title = {How energy flow shapes cell evolution.}, journal = {Current biology : CB}, volume = {30}, number = {10}, pages = {R471-R476}, doi = {10.1016/j.cub.2020.03.055}, pmid = {32428484}, issn = {1879-0445}, mesh = {Archaea/genetics/metabolism ; *Biological Evolution ; DNA, Mitochondrial/genetics ; Eukaryota/*genetics/*physiology ; Gene Deletion ; Mitochondria/genetics/*physiology ; }, abstract = {How mitochondria shaped the evolution of eukaryotic complexity has been controversial for decades. The discovery of the Asgard archaea, which harbor close phylogenetic ties to the eukaryotes, supports the idea that a critical endosymbiosis between an archaeal host and a bacterial endosymbiont transformed the selective constraints present at the origin of eukaryotes. Cultured Asgard archaea are typically prokaryotic in both size and internal morphology, albeit featuring extensive protrusions. The acquisition of the mitochondrial predecessor by an archaeal host cell fundamentally altered the topology of genes in relation to bioenergetic membranes. Mitochondria internalised not only the bioenergetic membranes but also the genetic machinery needed for local control of oxidative phosphorylation. Gene loss from mitochondria enabled expansion of the nuclear genome, giving rise to an extreme genomic asymmetry that is ancestral to all extant eukaryotes. This genomic restructuring gave eukaryotes thousands of fold more energy availability per gene. In principle, that difference can support more and larger genes, far more non-coding DNA, greater regulatory complexity, and thousands of fold more protein synthesis per gene. These changes released eukaryotes from the bioenergetic constraints on prokaryotes, facilitating the evolution of morphological complexity.}, }
@article {pmid32426508, year = {2020}, author = {Buerger, P and Alvarez-Roa, C and Coppin, CW and Pearce, SL and Chakravarti, LJ and Oakeshott, JG and Edwards, OR and van Oppen, MJH}, title = {Heat-evolved microalgal symbionts increase coral bleaching tolerance.}, journal = {Science advances}, volume = {6}, number = {20}, pages = {eaba2498}, pmid = {32426508}, issn = {2375-2548}, mesh = {Animals ; *Anthozoa/genetics/metabolism ; Coral Bleaching ; Coral Reefs ; *Dinoflagellida/genetics ; Hot Temperature ; *Microalgae ; Reactive Oxygen Species/metabolism ; Symbiosis/genetics ; }, abstract = {Coral reefs worldwide are suffering mass mortalities from marine heat waves. With the aim of enhancing coral bleaching tolerance, we evolved 10 clonal strains of a common coral microalgal endosymbiont at elevated temperatures (31°C) for 4 years in the laboratory. All 10 heat-evolved strains had expanded their thermal tolerance in vitro following laboratory evolution. After reintroduction into coral host larvae, 3 of the 10 heat-evolved endosymbionts also increased the holobionts' bleaching tolerance. Although lower levels of secreted reactive oxygen species (ROS) accompanied thermal tolerance of the heat-evolved algae, reduced ROS secretion alone did not predict thermal tolerance in symbiosis. The more tolerant symbiosis exhibited additional higher constitutive expression of algal carbon fixation genes and coral heat tolerance genes. These findings demonstrate that coral stock with enhanced climate resilience can be developed through ex hospite laboratory evolution of their microalgal endosymbionts.}, }
@article {pmid32417295, year = {2020}, author = {Bodnar, J and Fitch, S and Sanchez, J and Lesser, M and Baston, DS and Zhong, J}, title = {GTP cyclohydrolase I activity from Rickettsia monacensis strain Humboldt, a rickettsial endosymbiont of Ixodes pacificus.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {4}, pages = {101434}, pmid = {32417295}, issn = {1877-9603}, support = {R15 AI099902/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/genetics/*metabolism ; GTP Cyclohydrolase/genetics/*metabolism ; Ixodes/microbiology ; Rickettsia/*enzymology ; Sequence Alignment ; Symbiosis ; }, abstract = {The complete folate biosynthesis pathway exists in the genome of a rickettsial endosymbiont of Ixodes pacificus, Rickettsia monacensis strain Humboldt (formerly known as Rickettsia species phylotype G021). Recently, our lab demonstrated that the folA gene of strain Humboldt, the final gene in the folate biosynthesis pathway, encodes a functional dihydrofolate reductase enzyme. In this study, we report R. monacensis strain Humboldt has a functional GTP cyclohydrolase I (GCH1), an enzyme required for the hydrolysis of GTP to form 7,8-dihydroneopterin triphosphate in the folate biosynthesis pathway. The GCH1 gene of R. monacensis, folE, share homology with the folE gene of R. monacensis strain IrR/Munich, with a nucleotide sequence identity of 99%. Amino acid alignment and comparative protein structure modeling have shown that the FolE protein of R. monacensis has a conserved core subunit of GCH1 from the T-fold structural superfamily. All amino acid residues, including conserved GTP binding sites and zinc binding sites, are preserved in the FolE protein of R. monacensis. A recombinant GST-FolE protein from R. monacensis was overexpressed in Escherichia coli, purified by affinity chromatography, and assayed for enzyme activity in vitro. The in vitro enzymatic assay described in this study accorded the recombinant GCH1 enzyme of R. monacensis with a specific activity of 0.81 U/mg. Our data suggest folate genes of R. monacensis strain Humboldt have the potential to produce biochemically active enzymes for de novo folate synthesis, addressing the physioecological underpinnings behind tick-Rickettsia symbioses.}, }
@article {pmid32410239, year = {2020}, author = {Agtuca, BJ and Stopka, SA and Evans, S and Samarah, L and Liu, Y and Xu, D and Stacey, MG and Koppenaal, DW and Paša-Tolić, L and Anderton, CR and Vertes, A and Stacey, G}, title = {Metabolomic profiling of wild-type and mutant soybean root nodules using laser-ablation electrospray ionization mass spectrometry reveals altered metabolism.}, journal = {The Plant journal : for cell and molecular biology}, volume = {103}, number = {5}, pages = {1937-1958}, doi = {10.1111/tpj.14815}, pmid = {32410239}, issn = {1365-313X}, mesh = {Bradyrhizobium/*metabolism ; Carbon/metabolism ; Metabolomics/*methods ; Mutation/genetics ; Nitrogen/metabolism ; Nitrogen Fixation ; Root Nodules, Plant/metabolism/*microbiology ; Soybeans/metabolism/*microbiology ; Spectrometry, Mass, Electrospray Ionization ; Symbiosis ; }, abstract = {The establishment of the nitrogen-fixing symbiosis between soybean and Bradyrhizobium japonicum is a complex process. To document the changes in plant metabolism as a result of symbiosis, we utilized laser ablation electrospray ionization-mass spectrometry (LAESI-MS) for in situ metabolic profiling of wild-type nodules, nodules infected with a B. japonicum nifH mutant unable to fix nitrogen, nodules doubly infected by both strains, and nodules formed on plants mutated in the stearoyl-acyl carrier protein desaturase (sacpd-c) gene, which were previously shown to have an altered nodule ultrastructure. The results showed that the relative abundance of fatty acids, purines, and lipids was significantly changed in response to the symbiosis. The nifH mutant nodules had elevated levels of jasmonic acid, correlating with signs of nitrogen deprivation. Nodules resulting from the mixed inoculant displayed similar, overlapping metabolic distributions within the sectors of effective (fix[+]) and ineffective (nifH mutant, fix[-]) endosymbionts. These data are inconsistent with the notion that plant sanctioning is cell autonomous. Nodules lacking sacpd-c displayed an elevation of soyasaponins and organic acids in the central necrotic regions. The present study demonstrates the utility of LAESI-MS for high-throughput screening of plant phenotypes. Overall, nodules disrupted in the symbiosis were elevated in metabolites related to plant defense.}, }
@article {pmid32409535, year = {2020}, author = {Köstlbacher, S and Michels, S and Siegl, A and Schulz, F and Domman, D and Jongwutiwes, S and Putaporntip, C and Horn, M and Collingro, A}, title = {Draft Genome Sequences of Chlamydiales Bacterium STE3 and Neochlamydia sp. Strain AcF84, Endosymbionts of Acanthamoeba spp.}, journal = {Microbiology resource announcements}, volume = {9}, number = {20}, pages = {}, pmid = {32409535}, issn = {2576-098X}, abstract = {Chlamydiales bacterium STE3 and Neochlamydia sp. strain AcF84 are obligate intracellular symbionts of Acanthamoeba spp. isolated from the biofilm of a littoral cave wall and gills from striped tiger leaf fish, respectively. We report the draft genome sequences of these two environmental chlamydiae affiliated with the family Parachlamydiaceae.}, }
@article {pmid32402068, year = {2020}, author = {Sibbald, SJ and Archibald, JM}, title = {Genomic Insights into Plastid Evolution.}, journal = {Genome biology and evolution}, volume = {12}, number = {7}, pages = {978-990}, pmid = {32402068}, issn = {1759-6653}, mesh = {Amoeba ; *Biological Evolution ; Chromatophores ; Diatoms ; Genomics ; Photosynthesis ; *Plastids ; Symbiosis ; }, abstract = {The origin of plastids (chloroplasts) by endosymbiosis stands as one of the most important events in the history of eukaryotic life. The genetic, biochemical, and cell biological integration of a cyanobacterial endosymbiont into a heterotrophic host eukaryote approximately a billion years ago paved the way for the evolution of diverse algal groups in a wide range of aquatic and, eventually, terrestrial environments. Plastids have on multiple occasions also moved horizontally from eukaryote to eukaryote by secondary and tertiary endosymbiotic events. The overall picture of extant photosynthetic diversity can best be described as "patchy": Plastid-bearing lineages are spread far and wide across the eukaryotic tree of life, nested within heterotrophic groups. The algae do not constitute a monophyletic entity, and understanding how, and how often, plastids have moved from branch to branch on the eukaryotic tree remains one of the most fundamental unsolved problems in the field of cell evolution. In this review, we provide an overview of recent advances in our understanding of the origin and spread of plastids from the perspective of comparative genomics. Recent years have seen significant improvements in genomic sampling from photosynthetic and nonphotosynthetic lineages, both of which have added important pieces to the puzzle of plastid evolution. Comparative genomics has also allowed us to better understand how endosymbionts become organelles.}, }
@article {pmid32397333, year = {2020}, author = {Ghosh, S and Sela, N and Kontsedalov, S and Lebedev, G and Haines, LR and Ghanim, M}, title = {An Intranuclear Sodalis-Like Symbiont and Spiroplasma Coinfect the Carrot Psyllid, Bactericera trigonica (Hemiptera, Psylloidea).}, journal = {Microorganisms}, volume = {8}, number = {5}, pages = {}, pmid = {32397333}, issn = {2076-2607}, abstract = {Endosymbionts harbored inside insects play critical roles in the biology of their insect host and can influence the transmission of pathogens by insect vectors. Bactericera trigonica infests umbelliferous plants and transmits the bacterial plant pathogen Candidatus Liberibacter solanacearum (CLso), causing carrot yellows disease. To characterize the bacterial diversity of B. trigonica, as a first step, we used PCR-restriction fragment length polymorphism (PCR-RFLP) and denaturing gradient gel electrophoresis (DGGE) analyses of 16S rDNA to identify Sodalis and Spiroplasma endosymbionts. The prevalence of both symbionts in field-collected psyllid populations was determined: Sodalis was detected in 100% of field populations, while Spiroplasma was present in 82.5% of individuals. Phylogenetic analysis using 16S rDNA revealed that Sodalis infecting B. trigonica was more closely related to symbionts infecting weevils, stink bugs and tsetse flies than to those from psyllid species. Using fluorescent in situ hybridization and immunostaining, Sodalis was found to be localized inside the nuclei of the midgut cells and bacteriocytes. Spiroplasma was restricted to the cytoplasm of the midgut cells. We further show that a recently reported Bactericera trigonica densovirus (BtDNV), a densovirus infecting B. trigonica was detected in 100% of psyllids and has reduced titers inside CLso-infected psyllids by more than two-fold compared to CLso uninfected psyllids. The findings of this study will help to increase our understanding of psyllid-endosymbiont interactions.}, }
@article {pmid32391935, year = {2020}, author = {Kaur, R and Martinez, J and Rota-Stabelli, O and Jiggins, FM and Miller, WJ}, title = {Age, tissue, genotype and virus infection regulate Wolbachia levels in Drosophila.}, journal = {Molecular ecology}, volume = {29}, number = {11}, pages = {2063-2079}, doi = {10.1111/mec.15462}, pmid = {32391935}, issn = {1365-294X}, support = {P 28255/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {*Age Factors ; Animals ; *Drosophila/genetics/microbiology/virology ; Genotype ; *Symbiosis/genetics ; *Virus Diseases ; *Wolbachia ; }, abstract = {The bacterial symbiont Wolbachia can protect insects against viral pathogens, and the varying levels of antiviral protection are correlated with the endosymbiont load within the insects. To understand why Wolbachia strains differ in their antiviral effects, we investigated the factors controlling Wolbachia density in five closely related strains in their natural Drosophila hosts. We found that Wolbachia density varied greatly across different tissues and between flies of different ages, and these effects depended on the host-symbiont association. Some endosymbionts maintained largely stable densities as flies aged while others increased, and these effects in turn depended on the tissue being examined. Measuring Wolbachia rRNA levels in response to viral infection, we found that viral infection itself also altered Wolbachia levels, with Flock House virus causing substantial reductions in symbiont loads late in the infection. This effect, however, was virus-specific as Drosophila C virus had little impact on Wolbachia in all of the five host systems. Because viruses have strong tissue tropisms and antiviral protection is thought to be cell-autonomous, these effects are likely to affect the virus-blocking phenomenon. However, we were unable to find any evidence of a correlation between Wolbachia and viral titres within the same tissues. We conclude that Wolbachia levels within flies are regulated in a complex host-symbiont-virus-dependent manner and this trinity is likely to influence the antiviral effects of Wolbachia.}, }
@article {pmid32390951, year = {2020}, author = {Ben-Yosef, M and Rot, A and Mahagna, M and Kapri, E and Behar, A and Gottlieb, Y}, title = {Coxiella-Like Endosymbiont of Rhipicephalus sanguineus Is Required for Physiological Processes During Ontogeny.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {493}, pmid = {32390951}, issn = {1664-302X}, abstract = {Obligatory hematophagous arthropods such as lice, bugs, flies, and ticks harbor bacterial endosymbionts that are expected to complement missing essential nutrients in their diet. Genomic and some experimental evidence support this expectation. Hard ticks (Acari: Ixodidae) are associated with several lineages of bacterial symbionts, and very few were experimentally shown to be essential to some aspects of tick's fitness. In order to pinpoint the nature of interactions between hard ticks and their symbionts, we tested the effect of massive elimination of Coxiella-like endosymbionts (CLE) by antibiotics on the development and fitness of the brown dog tick (Rhipicephalus sanguineus). Administration of ofloxacin to engorged (blood fed) nymphs resulted in significant and acute reduction of their CLE loads - an effect that also persisted in subsequent life stages (aposymbiotic ticks). As a result, the post-feeding development of aposymbiotic female (but not male) nymphs was delayed. Additionally, aposymbiotic adult females needed a significantly prolonged feeding period in order to replete (detach from host), and had reduced engorgement weight and a lower capacity to produce eggs. Consequently, their fecundity and fertility were significantly reduced. Eggs produced by aposymbiotic females were free of CLE, and the resulting aposymbiotic larvae were unable to feed successfully. Our findings demonstrate that the observed fitness effects are due to CLE reduction and not due to antibiotic administration. Additionally, we suggest that the contribution of CLE is not mandatory for oocyte development and embryogenesis, but is required during feeding in females, when blood meal processing and tissue buildup are taking place. Presumably, under these extreme physiological demands, CLE contribute to R. sanguineus through supplementing essential micro- and macronutrients. Further nutrient complementary studies are required to support this hypothesis.}, }
@article {pmid32388920, year = {2020}, author = {Zhu, YX and Song, ZR and Song, YL and Hong, XY}, title = {Double infection of Wolbachia and Spiroplasma alters induced plant defense and spider mite fecundity.}, journal = {Pest management science}, volume = {76}, number = {9}, pages = {3273-3281}, doi = {10.1002/ps.5886}, pmid = {32388920}, issn = {1526-4998}, mesh = {Animals ; Fertility ; *Mites ; *Spiroplasma ; *Tetranychidae ; *Wolbachia ; }, abstract = {BACKGROUND: Herbivore-associated bacterial symbionts can change plant physiology and influence herbivore fitness. The spider mite Tetranychus truncatus is a notorious pest harboring various bacterial symbionts; however, the effect of bacterial symbionts on host plant physiology remains unclear. Here, we investigated whether infection with the endosymbionts Wolbachia and Spiroplasma altered spider mite performance on tomato plants and affected plant-induced defenses.<br><br>RESULTS: Wolbachia and Spiroplasma were mainly located in the gnathosoma and ovaries of their spider mite hosts. Wolbachia and Spiroplasma significantly improved spider mite reproductive performance in cultivated and wild-type tomato. However, in plants deficient in jasmonic acid (JA) and salicylic acid (SA), there were no significant differences in reproduction between spider mites infected with Wolbachia and Spiroplasma and uninfected mites. The results indicated that the reproduction benefits conferred by endosymbionts may relate to plant defenses. Both spider mites infected with Wolbachia and Spiroplasma and uninfected mites induced similar levels of JA and SA accumulation in tomato, whereas tomato plants damaged by spider mites infected with both Wolbachia and Spiroplasma showed lower expression levels of JA- and SA-responsive genes than those damaged by uninfected spider mites. In addition, mites infected with Wolbachia and Spiroplasma mites consumed more tomato amino acids compared to uninfected spider mites, which may have contributed to host fecundity.<br><br>CONCLUSIONS: Our results suggest that the reproduction benefits conferred by endosymbionts may be associated with changes in plant defense parameters and the concentrations of plant amino acids. The results highlight the importance of endosymbionts in interactions between spider mites and their host plants. &#xa9; 2020 Society of Chemical Industry.}, }
@article {pmid32386316, year = {2020}, author = {Rouïl, J and Jousselin, E and Coeur d'acier, A and Cruaud, C and Manzano-Marín, A}, title = {The Protector within: Comparative Genomics of APSE Phages across Aphids Reveals Rampant Recombination and Diverse Toxin Arsenals.}, journal = {Genome biology and evolution}, volume = {12}, number = {6}, pages = {878-889}, pmid = {32386316}, issn = {1759-6653}, mesh = {Animals ; Aphids/*microbiology ; Bacteriophages/*genetics ; Gammaproteobacteria/genetics/*virology ; Genome, Viral ; Phylogeny ; Symbiosis ; }, abstract = {Phages can fundamentally alter the physiology and metabolism of their hosts. Although these phages are ubiquitous in the bacterial world, they have seldom been described among endosymbiotic bacteria. One notable exception is the APSE phage that is found associated with the gammaproteobacterial Hamiltonella defensa, hosted by several insect species. This secondary facultative endosymbiont is not necessary for the survival of its hosts but can infect certain individuals or even whole populations. Its infection in aphids is often associated with protection against parasitoid wasps. This protective phenotype has actually been linked to the infection of the symbiont strain with an APSE, which carries a toxin cassette that varies among so-called "types." In the present work, we seek to expand our understanding of the diversity of APSE phages as well as the relations of their Hamiltonella hosts. For this, we assembled and annotated the full genomes of 16 APSE phages infecting Hamiltonella symbionts across ten insect species. Molecular and phylogenetic analyses suggest that recombination has occurred repeatedly among lineages. Comparative genomics of the phage genomes revealed two variable regions that are useful for phage typing. Additionally, we find that mobile elements could play a role in the acquisition of new genes in the toxin cassette. Altogether, we provide an unprecedented view of APSE diversity and their genome evolution across aphids. This genomic investigation will provide a valuable resource for the design and interpretation of experiments aiming at understanding the protective phenotype these phages confer to their insect hosts.}, }
@article {pmid32382991, year = {2020}, author = {Špitalská, E and Kraljik, J and Miklisová, D and Boldišová, E and Sparagano, OAE and Stanko, M}, title = {Circulation of Rickettsia species and rickettsial endosymbionts among small mammals and their ectoparasites in Eastern Slovakia.}, journal = {Parasitology research}, volume = {119}, number = {7}, pages = {2047-2057}, doi = {10.1007/s00436-020-06701-8}, pmid = {32382991}, issn = {1432-1955}, mesh = {Animals ; DNA, Bacterial/genetics ; Ectoparasitic Infestations/microbiology ; Mites/*microbiology ; Rickettsia/classification/genetics/physiology ; Rickettsia Infections/epidemiology/*transmission ; Rodentia/*parasitology ; Shrews/*parasitology ; Siphonaptera/*microbiology ; Slovakia/epidemiology ; Ticks/*microbiology ; Vector Borne Diseases/epidemiology/*microbiology/transmission ; }, abstract = {Bacteria belonging to the genus Rickettsia are known as causative agents of vector-borne zoonotic diseases, such as spotted fevers, epidemic typhus and endemic typhus. Different species of ticks, mites and fleas could act as reservoirs and arthropod vectors of different pathogenic Rickettsia species. The aim of this work was to establish active surveillance of Rickettsia spp. in mites, ticks and fleas collected from small mammals (rodents and shrews) in Eastern Slovakia. A total of 964 animal ear biopsies, 871 mites, 667 ticks and 743 fleas were collected from small mammals in the Košice region, Eastern Slovakia. All specimens were identified using specialized taxonomic keys, and were conserved in ethanol until DNA extraction was performed. After DNA extraction, identification of Rickettsia species was performed by PCR-based methods. The total prevalence of rickettsiae from ear biopsies was 4.6% (95% CI, 3.2-5.9), in tested mites 9.3% (95% CI, 7.4-11.2), 17.2% (95% CI, 14.3-20.1) in I. ricinus ticks and 3.5% (95% CI, 2.2-4.8) in fleas. Sequence analysis of the partial gltA gene and Rickettsia helvetica-, Rickettsia slovaca-, Rickettsia raoultii- species specific real-time PCR tests revealed the presence of R. helvetica, R. slovaca, unidentified Rickettsia and rickettsial endosymbionts. These pathogenic and symbiotic species were confirmed in the following ectoparasite species-Laelaps jettmari, Haemogamasus nidi, Laelaps agilis and Eulaelaps stabularis mites, Ixodes ricinus ticks, Ctenophthalmus solutus, C. assimilis and Megabothris turbidus fleas infesting host-Apodemus agrarius, A. flavicollis, Microtus arvalis and Myodes glareolus small mammals. These results confirm the circulation of R. helvetica, R. slovaca, unidentified Rickettsia and rickettsial endosymbionts in mites, ticks and fleas collected on small mammals in the Košice region, Eastern Slovakia.}, }
@article {pmid32358914, year = {2020}, author = {Sinno, M and Bézier, A and Vinale, F and Giron, D and Laudonia, S and Garonna, AP and Pennacchio, F}, title = {Symbiosis disruption in the olive fruit fly, Bactrocera oleae (Rossi), as a potential tool for sustainable control.}, journal = {Pest management science}, volume = {76}, number = {9}, pages = {3199-3207}, doi = {10.1002/ps.5875}, pmid = {32358914}, issn = {1526-4998}, mesh = {Animals ; Drosophila ; *Erwinia ; Female ; Fruit ; *Olea ; Symbiosis ; *Tephritidae ; }, abstract = {BACKGROUND: The olive fruit fly Bactrocera oleae (Rossi) (OLF) is a major agricultural pest, whose control primarily relies on the use of chemical insecticides. Therefore, development of sustainable control strategies is highly desirable. The primary endosymbiotic bacterium of OLF, 'Candidatus Erwinia dacicola', is essential for successful larval development in unripe olive fruits. Therefore, targeting this endosymbiont with antimicrobial compounds may result in OLF fitness reduction and may exert control on natural populations of OLF.<br><br>RESULTS: Here, we evaluate the impact of compounds with antimicrobial activity on the OLF endosymbiont. Copper oxychloride (CO) and the fungal metabolite viridiol (Vi), produced by Trichoderma spp., were used. Laboratory bioassays were carried out to assess the effect of oral administration of these compounds on OLF fitness and molecular analyses (quantitative polymerase chain reaction) were conducted to measure the load of OLF-associated microorganisms in treated flies. CO and Vi were both able to disrupt the symbiotic association between OLF and its symbiotic bacteria, determining a significant reduction in the endosymbiont and gut microbiota load as well as a decrease in OLF fitness. CO had a direct negative effect on OLF adults. Conversely, exposure to Vi significantly undermined larval development of the treated female's progeny but did not show any toxicity in OLF adults.<br><br>CONCLUSIONS: These results provide new insights into the symbiotic control of OLF and pave the way for the development of more sustainable strategies of pest control based on the use of natural compounds with antimicrobial activity. &#xa9; 2020 Society of Chemical Industry.}, }
@article {pmid32354088, year = {2020}, author = {Roberty, S and Béraud, E and Grover, R and Ferrier-Pagès, C}, title = {Coral Productivity Is Co-Limited by Bicarbonate and Ammonium Availability.}, journal = {Microorganisms}, volume = {8}, number = {5}, pages = {}, pmid = {32354088}, issn = {2076-2607}, abstract = {The nitrogen environment and nitrogen status of reef-building coral endosymbionts is one of the important factors determining the optimal assimilation of phototrophic carbon and hence the growth of the holobiont. However, the impact of inorganic nutrient availability on the photosynthesis and physiological state of the coral holobiont is partly understood. This study aimed to determine if photosynthesis of the endosymbionts associated with the coral Stylophora pistillata and the overall growth of the holobiont were limited by the availability of dissolved inorganic carbon and nitrogen in seawater. For this purpose, colonies were incubated in absence or presence of 4 µM ammonium and/or 6 mM bicarbonate. Photosynthetic performances, pigments content, endosymbionts density and growth rate of the coral colonies were monitored for 3 weeks. Positive effects were observed on coral physiology with the supplementation of one or the other nutrient, but the most important changes were observed when both nutrients were provided. The increased availability of DIC and NH4[+] significantly improved the photosynthetic efficiency and capacity of endosymbionts, in turn enhancing the host calcification rate. Overall, these results suggest that in hospite symbionts are co-limited by nitrogen and carbon availability for an optimal photosynthesis.}, }
@article {pmid32351785, year = {2020}, author = {Modeo, L and Salvetti, A and Rossi, L and Castelli, M and Szokoli, F and Krenek, S and Serra, V and Sabaneyeva, E and Di Giuseppe, G and Fokin, SI and Verni, F and Petroni, G}, title = {"Candidatus Trichorickettsia mobilis", a Rickettsiales bacterium, can be transiently transferred from the unicellular eukaryote Paramecium to the planarian Dugesia japonica.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e8977}, pmid = {32351785}, issn = {2167-8359}, abstract = {Most of the microorganisms responsible for vector-borne diseases (VBD) have hematophagous arthropods as vector/reservoir. Recently, many new species of microorganisms phylogenetically related to agents of VBD were found in a variety of aquatic eukaryotic hosts; in particular, numerous new bacterial species related to the genus Rickettsia (Alphaproteobacteria, Rickettsiales) were discovered in protist ciliates and other unicellular eukaryotes. Although their pathogenicity for humans and terrestrial animals is not known, several indirect indications exist that these bacteria might act as etiological agents of possible VBD of aquatic organisms, with protists as vectors. In the present study, a novel strain of the Rickettsia-Like Organism (RLO) endosymbiont "Candidatus (Ca.) Trichorickettsia mobilis" was identified in the macronucleus of the ciliate Paramecium multimicronucleatum. We performed transfection experiments of this RLO to planarians (Dugesia japonica) per os. Indeed, the latter is a widely used model system for studying bacteria pathogenic to humans and other Metazoa. In transfection experiments, homogenized paramecia were added to food of antibiotic-treated planarians. Treated and non-treated (i.e. control) planarians were investigated at day 1, 3, and 7 after feeding for endosymbiont presence by means of PCR and ultrastructural analyses. Obtained results were fully concordant and suggest that this RLO endosymbiont can be transiently transferred from ciliates to metazoans, being detected up to day 7 in treated planarians' enterocytes. Our findings might offer insights into the potential role of ciliates or other protists as putative vectors for diseases caused by Rickettsiales or other RLOs and occurring in fish farms or in the wild.}, }
@article {pmid32350156, year = {2020}, author = {Ganyukova, AI and Frolov, AO and Malysheva, MN and Spodareva, VV and Yurchenko, V and Kostygov, AY}, title = {A novel endosymbiont-containing trypanosomatid Phytomonas borealis sp. n. from the predatory bug Picromerus bidens (Heteroptera: Pentatomidae).}, journal = {Folia parasitologica}, volume = {67}, number = {}, pages = {}, doi = {10.14411/fp.2020.004}, pmid = {32350156}, issn = {1803-6465}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Heteroptera/growth &amp; development/*parasitology ; Nymph/growth &amp; development/parasitology ; Phylogeny ; RNA, Protozoan/analysis ; RNA, Ribosomal, 18S/analysis ; Russia ; *Symbiosis ; Trypanosomatina/*classification/microbiology ; }, abstract = {Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids.}, }
@article {pmid32349659, year = {2020}, author = {Ellis, JC}, title = {P finder: genomic and metagenomic annotation of RNase P RNA gene (rnpB).}, journal = {BMC genomics}, volume = {21}, number = {1}, pages = {334}, pmid = {32349659}, issn = {1471-2164}, mesh = {Algorithms ; Chloroflexi/enzymology/genetics ; Databases, Genetic ; *Genes, Microbial ; Genome, Microbial/genetics ; Genomics/*methods ; Metagenomics/methods ; Nucleic Acid Conformation ; Prokaryotic Cells/enzymology ; RNA, Catalytic/chemistry/classification/genetics ; Ribonuclease P/chemistry/classification/*genetics ; Software ; }, abstract = {BACKGROUND: The rnpB gene encodes for an essential catalytic RNA (RNase P). Like other essential RNAs, RNase P's sequence is highly variable. However, unlike other essential RNAs (i.e. tRNA, 16 S, 6 S,...) its structure is also variable with at least 5 distinct structure types observed in prokaryotes. This structural variability makes it labor intensive and challenging to create and maintain covariance models for the detection of RNase P RNA in genomic and metagenomic sequences. The lack of a facile and rapid annotation algorithm has led to the rnpB gene being the most grossly under annotated essential gene in completed prokaryotic genomes with only a 24% annotation rate. Here we describe the coupling of the largest RNase P RNA database with the local alignment scoring algorithm to create the most sensitive and rapid prokaryote rnpB gene identification and annotation algorithm to date.<br><br>RESULTS: Of the 2772 completed microbial genomes downloaded from GenBank only 665 genomes had an annotated rnpB gene. We applied P Finder to these genomes and were able to identify 2733 or nearly 99% of the 2772 microbial genomes examined. From these results four new rnpB genes that encode the minimal T-type P RNase P RNAs were identified computationally for the first time. In addition, only the second C-type RNase P RNA was identified in Sphaerobacter thermophilus. Of special note, no RNase P RNAs were detected in several obligate endosymbionts of sap sucking insects suggesting a novel evolutionary adaptation.<br><br>CONCLUSIONS: The coupling of the largest RNase P RNA database and associated structure class identification with the P Finder algorithm is both sensitive and rapid, yielding high quality results to aid researchers annotating either genomic or metagenomic data. It is the only algorithm to date that can identify challenging RNAse P classes such as C-type and the minimal T-type RNase P RNAs. P Finder is written in C# and has a user-friendly GUI that can run on multiple 64-bit windows platforms (Windows Vista/7/8/10). P Finder is free available for download at https://github.com/JChristopherEllis/P-Finder as well as a small sample RNase P RNA file for testing.}, }
@article {pmid32341569, year = {2020}, author = {López-García, P and Moreira, D}, title = {The Syntrophy hypothesis for the origin of eukaryotes revisited.}, journal = {Nature microbiology}, volume = {5}, number = {5}, pages = {655-667}, pmid = {32341569}, issn = {2058-5276}, mesh = {Archaea/genetics/*metabolism ; Bacteria/genetics ; *Biological Evolution ; Cell Nucleus ; Eukaryota/genetics/*metabolism ; Eukaryotic Cells/*metabolism ; Genome, Archaeal ; Hydrogen/metabolism ; Membranes/metabolism ; Mitochondria/metabolism ; Oxidation-Reduction ; *Phylogeny ; Sulfur/metabolism ; Symbiosis/physiology ; }, abstract = {The discovery of Asgard archaea, phylogenetically closer to eukaryotes than other archaea, together with improved knowledge of microbial ecology, impose new constraints on emerging models for the origin of the eukaryotic cell (eukaryogenesis). Long-held views are metamorphosing in favour of symbiogenetic models based on metabolic interactions between archaea and bacteria. These include the classical Searcy's and Hydrogen hypothesis, and the more recent Reverse Flow and Entangle-Engulf-Endogenize models. Two decades ago, we put forward the Syntrophy hypothesis for the origin of eukaryotes based on a tripartite metabolic symbiosis involving a methanogenic archaeon (future nucleus), a fermentative myxobacterial-like deltaproteobacterium (future eukaryotic cytoplasm) and a metabolically versatile methanotrophic alphaproteobacterium (future mitochondrion). A refined version later proposed the evolution of the endomembrane and nuclear membrane system by invagination of the deltaproteobacterial membrane. Here, we adapt the Syntrophy hypothesis to contemporary knowledge, shifting from the original hydrogen and methane-transfer-based symbiosis (HM Syntrophy) to a tripartite hydrogen and sulfur-transfer-based model (HS Syntrophy). We propose a sensible ecological scenario for eukaryogenesis in which eukaryotes originated in early Proterozoic microbial mats from the endosymbiosis of a hydrogen-producing Asgard archaeon within a complex sulfate-reducing deltaproteobacterium. Mitochondria evolved from versatile, facultatively aerobic, sulfide-oxidizing and, potentially, anoxygenic photosynthesizing alphaproteobacterial endosymbionts that recycled sulfur in the consortium. The HS Syntrophy hypothesis accounts for (endo)membrane, nucleus and metabolic evolution in a realistic ecological context. We compare and contrast the HS Syntrophy hypothesis to other models of eukaryogenesis, notably in terms of the mode and tempo of eukaryotic trait evolution, and discuss several model predictions and how these can be tested.}, }
@article {pmid32339445, year = {2021}, author = {Lv, N and Peng, J and Chen, XY and Guo, CF and Sang, W and Wang, XM and Ahmed, MZ and Xu, YY and Qiu, BL}, title = {Antagonistic interaction between male-killing and cytoplasmic incompatibility induced by Cardinium and Wolbachia in the whitefly, Bemisia tabaci.}, journal = {Insect science}, volume = {28}, number = {2}, pages = {330-346}, doi = {10.1111/1744-7917.12793}, pmid = {32339445}, issn = {1744-7917}, mesh = {Animals ; Bacteroidetes/*physiology ; Female ; Fertility ; Hemiptera/*microbiology/physiology ; Longevity ; Male ; Sex Ratio ; Wolbachia/*physiology ; }, abstract = {Cardinium and Wolbachia are maternally inherited bacterial symbionts of arthropods that can manipulate host reproduction by increasing the fitness of infected females. Here, we report that Cardinium and Wolbachia coinfection induced male-killing and cytoplasmic incompatibility (CI) when they coexisted in a cryptic species of whitefly, Bemisia tabaci Asia II7. Cardinium and Wolbachia symbionts were either singly or simultaneously localized in the bacteriocytes placed in the abdomen of B. tabaci nymphs and adults. Cardinium-Wolbachia coinfection induced male-killing and resulted in a higher female sex ratio in the intraspecific amphigenetic progeny of Asia II7 ICWH and ICWL lines; interestingly, male-killing induction was enhanced with increased Cardinium titer. Moreover, single infection of Wolbachia induced partial CI in the Asia II7 IW line and resulted in reduced fecundity, higher embryonic mortality, and lower female sex ratio. The uninfected Asia II7 IU line had significantly higher fecundity, lower embryonic and nymphal mortalities, and a lower level of CI than both the Wolbachia-infected Asia II7 IW line and the Cardinium-Wolbachia-coinfected Asia II7 ICWH line. Our findings indicate that Cardinium-Wolbachia coinfection induced male-killing, which may have had antagonistic effects on Wolbachia-induced CI in the Asia II7 whiteflies. For the first time, our study revealed that B. tabaci Asia II7 reproduction is co-manipulated by Cardinium and Wolbachia endosymbionts.}, }
@article {pmid32338395, year = {2020}, author = {Sass, K and Güllert, S and Streit, WR and Perner, M}, title = {A hydrogen-oxidizing bacterium enriched from the open ocean resembling a symbiont.}, journal = {Environmental microbiology reports}, volume = {12}, number = {4}, pages = {396-405}, doi = {10.1111/1758-2229.12847}, pmid = {32338395}, issn = {1758-2229}, support = {03G0253//Bundesministerium f&#xfc;r Bildung und Forschung/International ; }, mesh = {Animals ; Autotrophic Processes ; Bacteria/classification/genetics/isolation &amp; purification/*metabolism ; Ecosystem ; Hydrogen/*metabolism ; Hydrothermal Vents/microbiology ; Oxidation-Reduction ; Phylogeny ; Seawater/*microbiology ; Snails/*microbiology/physiology ; Symbiosis ; }, abstract = {A new autotrophic hydrogen-oxidizing Chromatiaceae bacterium, namely bacterium CTD079, was enriched from a water column sample at 1500 m water depth in the southern Pacific Ocean. Based on the phylogeny of 16S rRNA genes, it was closely related to a scaly snail endosymbiont (99.2% DNA sequence identity) whose host so far is only known to colonize hydrothermal vents along the Indian ridge. The average nucleotide identity between the genomes of CTD079 and the snail endosymbiont was 91%. The observed differences likely reflect adaptations to their specific habitats. For example, CTD079 encodes additional enzymes like the formate dehydrogenase increasing the organism's spectrum of energy generation pathways. Other additional physiological features of CTD079 included the increase of viral defence strategies, secretion systems and specific transporters for essential elements. These important genome characteristics suggest an adaptation to life in the open ocean.}, }
@article {pmid32329790, year = {2020}, author = {Coimbra-Dores, MJ and Jaarsma, RI and Carmo, AO and Maia-Silva, M and Fonville, M and da Costa, DFF and Brandão, RML and Azevedo, F and Casero, M and Oliveira, AC and Afonso, SMS and Sprong, H and Rosa, F and Dias, D}, title = {Mitochondrial sequences of Rhipicephalus and Coxiella endosymbiont reveal evidence of lineages co-cladogenesis.}, journal = {FEMS microbiology ecology}, volume = {96}, number = {6}, pages = {}, doi = {10.1093/femsec/fiaa072}, pmid = {32329790}, issn = {1574-6941}, mesh = {Animals ; Coxiella/genetics ; *Dog Diseases ; Dogs ; Genetic Speciation ; Phylogeny ; *Rhipicephalus ; *Rhipicephalus sanguineus ; *Rickettsia/genetics ; }, abstract = {Rhipicephalus ticks are competent vectors of several pathogens, such as Spotted Fever Group Rickettsiae (SFGR) and many Babesia species. Within this genus, different R. sanguineus s.l. lineages show an unequal vector competence and resistance regarding some pathogenic strains. Current literature supports that tick endosymbionts may play an essential role in the transmission ability of a vector. Indeed, the microbial community of Rhipicephalus seems to be dominated by Coxiella-like endosymbionts (CLE). Still, their co-evolutionary associations with the complicated phylogeny of Rhipicephalus lineages and their transmissible pathogens remain unclear. We performed a phylogenetic congruence analysis to address whether divergent R. sanguineus s.l. lineages had a different symbiont composition. For that, we applied a PCR based approach to screen part of the microbial community present in 279 Rhipicephalus ticks from the Iberian Peninsula and Africa. Our analyses detected several qPCR-positive signals for both SFGR and Babesia species, of which we suggest R. sanguineus-tropical lineage as a natural vector of Babesia vogeli and R. sanguineus-temperate lineage of SFGR. The acquisition of 190 CLE sequences allowed to evaluate co-phylogenetic associations between the tick and the symbiont. With this data, we observed a strong but incomplete co-cladogenesis between CLE strains and their Rhipicephalus tick lineages hosts.}, }
@article {pmid32322900, year = {2020}, author = {Osborne, CJ and Wakeman-Hill, AJ and Loa, SE and Crosbie, PR and Van Laar, TA}, title = {Rickettsia spp. in Five Tick Species Collected in Central California.}, journal = {Journal of medical entomology}, volume = {57}, number = {5}, pages = {1596-1603}, doi = {10.1093/jme/tjaa080}, pmid = {32322900}, issn = {1938-2928}, mesh = {Animals ; California ; Female ; Ixodidae/*microbiology ; Male ; Ornithodoros/*microbiology ; Phylogeny ; Rickettsia/genetics/*isolation &amp; purification ; }, abstract = {Tick-borne disease surveillance in North America has long focused on Lyme disease, though there is currently a significant shift towards comprehensive pathogen surveillance in ticks. Central California has often been overlooked in regular tick-borne pathogen surveillance despite the presence of numerous medically important tick species. The bacterial genus Rickettsia contains tick-borne species that are known pathogens, such as those in the spotted fever group; nonpathogenic endosymbionts; and many species with unknown pathogenic potential. Five common tick species (Ixodes pacificus Cooley and Kohls [Acari: Ixodidae], Dermacentor occidentalis Marx [Acari: Ixodidae], D. variabilis Say, Rhipicephalus sanguineus Latreille [Acari: Ixodidae], and Ornithodoros parkeri Cooley [Acari: Argasidae]) of California were collected by both traditional and modern techniques, and subsequently screened for Rickettsia spp. Many individuals from all five tick species were PCR positive for Rickettsia spp., and a combination of species-specific primers, a restriction fragment length polymorphism assay, and DNA sequencing was used to further characterize the species composition in these ticks. Probable Rickettsia philipii (Rickettsia 364D) was detected in one (1.56%) D. occidentalis collected in Fresno County; R. rhipicephali was detected in 23.4% of D. occidentalis from Fresno Co.; R. bellii was detected in 88.2% of D. variabilis, 7.8% of D. occidentalis, and in one R. rhipicephalus (1.1%) from Fresno Co.; R. monacensis str. Humboldt was detected in three (100%) of I. pacificus collected in both Fresno and Madera Co.; and an uncharacterized Rickettsia was detected in (26.4%) of O. parkeri collected in both Fresno and Madera Co. The findings in this study highlight the need for ongoing surveillance in this region of California.}, }
@article {pmid32317320, year = {2020}, author = {Koto, A and Nobu, MK and Miyazaki, R}, title = {Deep Sequencing Uncovers Caste-Associated Diversity of Symbionts in the Social Ant Camponotus japonicus.}, journal = {mBio}, volume = {11}, number = {2}, pages = {}, pmid = {32317320}, issn = {2150-7511}, mesh = {Animals ; Ants/classification/*microbiology/*physiology ; *Behavior, Animal ; Gastrointestinal Microbiome ; *High-Throughput Nucleotide Sequencing ; *Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Social Behavior ; *Symbiosis ; }, abstract = {Symbiotic microorganisms can have a profound impact on the host physiology and behavior, and novel relationships between symbionts and their hosts are continually discovered. A colony of social ants consists of various castes that exhibit distinct lifestyles and is, thus, a unique model for investigating how symbionts may be involved in host eusociality. Yet our knowledge of social ant-symbiont dynamics has remained rudimentary. Through 16S rRNA gene deep sequencing of the carpenter ant Camponotus japonicus symbiont community across various castes, we here report caste-dependent diversity of commensal gut microbiota and lineage divergence of "Candidatus Blochmannia," an obligate endosymbiont. While most prevalent gut-associated bacterial populations are found across all castes (Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and Cyanobacteria), we also discovered uncultured populations that are found only in males (belonging to Corynebacteriales, Alkanindiges, and Burkholderia). Most of those populations are not detected in laboratory-maintained queens and workers, suggesting that they are facultative gut symbionts introduced via environmental acquisition. Further inspection of "Ca. Blochmannia" endosymbionts reveals that two populations are dominant in all individuals across all castes but that males preferentially contain two different sublineages that are diversified from others. Clearly, each caste has distinct symbiont communities, suggesting an overlooked biological aspect of host-symbiont interaction in social insects.IMPORTANCE Social animals, such as primates and some insects, have been shown to exchange symbiotic microbes among individuals through sharing diet or habitats, resulting in increased consistency of microbiota among social partners. The ant is a representative of social insects exhibiting various castes within a colony; queens, males, and nonreproductive females (so-called workers) show distinct morphologies, physiologies, and behaviors but tightly interact with each other in the nest. However, how this social context affects their gut microbiota has remained unclear. In this study, we deeply sequenced the gut symbiont community across various castes of the carpenter ant Camponotus japonicus We report caste-dependent diversity of commensal gut microbial community and lineage divergence of the mutualistic endosymbiont "Candidatus Blochmannia." This report sheds light on the hidden diversity in microbial populations and community structure associated with guts of males in social ants.}, }
@article {pmid32314065, year = {2020}, author = {Shamseldin, A and Velázquez, E}, title = {The promiscuity of Phaseolus vulgaris L. (common bean) for nodulation with rhizobia: a review.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {36}, number = {5}, pages = {63}, pmid = {32314065}, issn = {1573-0972}, mesh = {Africa ; Asia ; Bradyrhizobium/isolation &amp; purification/metabolism ; Burkholderiaceae/isolation &amp; purification/metabolism ; Cupriavidus/isolation &amp; purification/metabolism ; Europe ; Phaseolus/*microbiology ; Phylogeny ; Phylogeography ; Rhizobium/*isolation &amp; purification/metabolism ; Root Nodules, Plant/*microbiology ; Seeds/microbiology ; Soil Microbiology ; *Symbiosis ; United States ; }, abstract = {Phaseolus vulgaris L. (common bean) is a legume indigenous to American countries currently cultivated in all continents, which is nodulated by different rhizobial species and symbiovars. Most of species able to nodulate this legume worldwide belong to the genus Rhizobium, followed by those belonging to the genera Ensifer (formerly Sinorhizobium) and Pararhizobium (formerly Rhizobium) and minority by species of the genus Bradyrhizobium. All these genera belong to the phylum alpha-Proteobacteria, but the nodulation of P. vulgaris has also been reported for some species belonging to Paraburkholderia and Cupriavidus from the beta-Proteobacteria. Several species nodulating P. vulgaris were originally isolated from nodules of this legume in American countries and are linked to the symbiovars phaseoli and tropici, which are currently present in other continents probably because they were spread in their soils together with the P. vulgaris seeds. In addition, this legume can be nodulated by species and symbiovars originally isolated from nodules of other legumes due its high promiscuity, a concept currently related with the ability of a legume to be nodulated by several symbiovars rather than by several species. In this article we review the species and symbiovars able to nodulate P. vulgaris in different countries and continents and the challenges on the study of the P. vulgaris endosymbionts diversity in those countries where they have not been studied yet, that will allow to select highly effective rhizobial strains in order to guarantee the success of P. vulgaris inoculation.}, }
@article {pmid32299882, year = {2020}, author = {Sato, Y and Wippler, J and Wentrup, C and Dubilier, N and Kleiner, M}, title = {High-Quality Draft Genome Sequences of Two Deltaproteobacterial Endosymbionts, Delta1a and Delta1b, from the Uncultured Sva0081 Clade, Assembled from Metagenomes of the Gutless Marine Worm Olavius algarvensis.}, journal = {Microbiology resource announcements}, volume = {9}, number = {16}, pages = {}, pmid = {32299882}, issn = {2576-098X}, abstract = {Here, we present high-quality metagenome-assembled genome sequences of two closely related deltaproteobacterial endosymbionts from the gutless marine worm Olavius algarvensis (Annelida). The first is an improved draft genome sequence of the previously described sulfate-reducing symbiont Delta1. The second is from a closely related, recently discovered symbiont of O. algarvensis.}, }
@article {pmid32295978, year = {2020}, author = {Takashima, Y and Degawa, Y and Nishizawa, T and Ohta, H and Narisawa, K}, title = {Aposymbiosis of a Burkholderiaceae-Related Endobacterium Impacts on Sexual Reproduction of Its Fungal Host.}, journal = {Microbes and environments}, volume = {35}, number = {2}, pages = {}, pmid = {32295978}, issn = {1347-4405}, mesh = {Biological Evolution ; Burkholderiaceae/drug effects/*physiology ; Ciprofloxacin/pharmacology ; Mortierella/*physiology ; Mycelium/physiology ; Reproduction ; Spores, Fungal/physiology ; Symbiosis ; }, abstract = {Bacterial endosymbionts inhabit diverse fungal lineages. Although the number of studies on bacteria is increasing, the mechanisms by which bacteria affect their fungal hosts remain unclear. We herein examined the homothallic isolate, Mortierella sugadairana YTM39, harboring a Burkholderiaceae-related endobacterium, which did not produce sexual spores. We successfully eliminated the bacterium from fungal isolates using ciprofloxacin treatment and asexual spore isolation for germinated asexual spores. Sexual spore formation by the fungus was restored by eliminating the bacterium from isolates. These results indicate that sexual reproduction by the fungus was inhibited by the bacterium. This is the first study on the sexual spore infertility of fungal hosts by endofungal bacteria.}, }
@article {pmid32289879, year = {2020}, author = {Gabr, A and Grossman, AR and Bhattacharya, D}, title = {Paulinella, a model for understanding plastid primary endosymbiosis.}, journal = {Journal of phycology}, volume = {56}, number = {4}, pages = {837-843}, pmid = {32289879}, issn = {1529-8817}, support = {80NSSC19K0462/ImNASA/Intramural NASA/United States ; 1756616//National Science Foundation/International ; 80NSSC19K0462/NASA/NASA/United States ; NJ01170//National Institute of Food and Agriculture/International ; }, mesh = {*Amoeba ; Biological Evolution ; *Chromatophores ; Phylogeny ; Plastids ; *Rhizaria ; Symbiosis ; }, abstract = {The uptake and conversion of a free-living cyanobacterium into a photosynthetic organelle by the single-celled Archaeplastida ancestor helped transform the biosphere from low to high oxygen. There are two documented, independent cases of plastid primary endosymbiosis. The first is the well-studied instance in Archaeplastida that occurred ca. 1.6 billion years ago, whereas the second occurred 90-140 million years ago, establishing a permanent photosynthetic compartment (the chromatophore) in amoebae in the genus Paulinella. Here, we briefly summarize knowledge about plastid origin in the Archaeplastida and then focus on Paulinella. In particular, we describe features of the Paulinella chromatophore that make it a model for examining earlier events in the evolution of photosynthetic organelles. Our review stresses recently gained insights into the evolution of chromatophore and nuclear encoded DNA sequences in Paulinella, metabolic connectivity between the endosymbiont and cytoplasm, and systems that target proteins into the chromatophore. We also describe future work with Paulinella, and the potential rewards and challenges associated with developing further this model system.}, }
@article {pmid32281227, year = {2020}, author = {Acuña-Rodríguez, IS and Newsham, KK and Gundel, PE and Torres-Díaz, C and Molina-Montenegro, MA}, title = {Functional roles of microbial symbionts in plant cold tolerance.}, journal = {Ecology letters}, volume = {23}, number = {6}, pages = {1034-1048}, doi = {10.1111/ele.13502}, pmid = {32281227}, issn = {1461-0248}, mesh = {Biomass ; *Mycorrhizae ; Plant Physiological Phenomena ; Plant Roots ; Plants ; Symbiosis ; }, abstract = {In this review, we examine the functional roles of microbial symbionts in plant tolerance to cold and freezing stresses. The impacts of symbionts on antioxidant activity, hormonal signaling and host osmotic balance are described, including the effects of the bacterial endosymbionts Burkholderia, Pseudomonas and Azospirillum on photosynthesis and the accumulation of carbohydrates such as trehalose and raffinose that improve cell osmotic regulation and plasma membrane integrity. The influence of root fungal endophytes and arbuscular mycorrhizal fungi on plant physiology at low temperatures, for example their effects on nutrient acquisition and the accumulation of indole-3-acetic acid and antioxidants in tissues, are also reviewed. Meta-analyses are presented showing that aspects of plant performance (shoot biomass, relative water content, sugar and proline concentrations and Fv /Fm) are enhanced in symbiotic plants at low (-1 to 15 °C), but not at high (20-26 °C), temperatures. We discuss the implications of microbial symbionts for plant performance at low and sub-zero temperatures in the natural environment and propose future directions for research into the effects of symbionts on the cold and freezing tolerances of plants, concluding that further studies should routinely incorporate symbiotic microbes in their experimental designs.}, }
@article {pmid32281201, year = {2020}, author = {Nieves-Morión, M and Flores, E and Foster, RA}, title = {Predicting substrate exchange in marine diatom-heterocystous cyanobacteria symbioses.}, journal = {Environmental microbiology}, volume = {22}, number = {6}, pages = {2027-2052}, doi = {10.1111/1462-2920.15013}, pmid = {32281201}, issn = {1462-2920}, support = {//Knut and Alice Wallenberg Foundation/International ; BFU2017-88202-P//Spanish Government and European Regional Development Fund/International ; 2018-04161//The Swedish Research Council/International ; }, mesh = {Biological Transport/*physiology ; Carrier Proteins/metabolism ; Cyanobacteria/genetics/*metabolism/physiology ; Diatoms/genetics/*microbiology ; Genome Size ; Nitrogen/metabolism ; Nitrogen Fixation ; Phytoplankton/*metabolism/physiology ; Symbiosis/physiology ; }, abstract = {In the open ocean, some phytoplankton establish symbiosis with cyanobacteria. Some partnerships involve diatoms as hosts and heterocystous cyanobacteria as symbionts. Heterocysts are specialized cells for nitrogen fixation, and a function of the symbiotic cyanobacteria is to provide the host with nitrogen. However, both partners are photosynthetic and capable of carbon fixation, and the possible metabolites exchanged and mechanisms of transfer are poorly understood. The symbiont cellular location varies from internal to partial to fully external, and this is reflected in the symbiont genome size and content. In order to identify the membrane transporters potentially involved in metabolite exchange, we compare the draft genomes of three differently located symbionts with known transporters mainly from model free-living heterocystous cyanobacteria. The types and numbers of transporters are directly related to the symbiont cellular location: restricted in the endosymbionts and wider in the external symbiont. Three proposed models of metabolite exchange are suggested which take into account the type of transporters in the symbionts and the influence of their cellular location on the available nutrient pools. These models provide a basis for several hypotheses that given the importance of these symbioses in global N and C budgets, warrant future testing.}, }
@article {pmid32276978, year = {2020}, author = {Huang, Z and Wang, D and Li, J and Wei, C and He, H}, title = {Transovarial Transmission of Bacteriome-Associated Symbionts in the Cicada Pycna repanda (Hemiptera: Cicadidae).}, journal = {Applied and environmental microbiology}, volume = {86}, number = {12}, pages = {}, pmid = {32276978}, issn = {1098-5336}, mesh = {Animals ; Bacterial Physiological Phenomena ; Female ; Hemiptera/*microbiology ; Male ; Ovary/microbiology ; Ovum/microbiology ; *Symbiosis ; }, abstract = {Although transovarial transmission of bacteriome-associated symbionts in hemipteran insects is extremely important for maintaining intimate host-symbiont associations, our knowledge of cellular mechanisms underlying the transmission process is quite limited. We investigated bacterial communities of salivary glands, bacteriomes, and digestive and reproductive organs and clarified the transovarial transmission of bacteriome-associated symbionts of the mountain-habitat specialist Pycna repanda using integrated methods. The bacterial communities among different gut tissues and those of bacteriomes of males and females both show similarity, whereas differences are exhibited among bacterial communities in testes and ovaries. The primary symbionts "Candidatus Sulcia muelleri" (hereafter "Ca Sulcia") and "Candidatus Hodgkinia cicadicola" (hereafter "Ca Hodgkinia") were not only restricted to but also dominant in the bacteriomes and ovaries. "Ca Hodgkinia" cells in the bacteriomes of both sexes exhibited different colors by histological and electron microscopy. Also considering the results of a restriction fragment length polymorphism (RFLP)-based cloning approach, we hypothesize that "Ca Hodgkinia" may have split into cytologically different cellular lineages within this cicada species. Regarding the dominant secondary symbionts, Rickettsia was detected in the salivary glands, digestive organs, and testes, whereas Arsenophonus was detected in the bacteriomes and ovaries. Our results show that Arsenophonus can coexist with "Ca Sulcia" and "Ca Hodgkinia" within bacteriomes and can be transovarially transmitted with these obligate symbionts together from mother to offspring in cicadas, but it is not harbored in the cytoplasm of "Ca Sulcia." The change in the shape of "Ca Sulcia" and "Ca Hodgkinia" during the transovarial transmission process is hypothesized to be related to the limited space and novel microenvironment.IMPORTANCE Cicadas establish an intimate symbiosis with microorganisms to obtain essential nutrients that are extremely deficient in host plant sap. Previous studies on bacterial communities of cicadas mainly focused on a few widely distributed species, but knowledge about mountain-habitat species is quite poor. We initially revealed the physical distribution of the primary symbionts "Ca Sulcia" and "Ca Hodgkinia" and the dominant secondary symbionts Rickettsia and Arsenophonus in the mountain-habitat specialist Pycna repanda and then clarified the transovarial transmission process of bacteriome-associated symbionts in this species. Our observations suggest that "Ca Hodgkinia" may have split into cytologically distinct lineages within this cicada species, and related cicadas might have developed complex mechanisms for the vertical transmission of the bacteriome-associated symbionts. We also revealed that Arsenophonus can be transovarially transmitted in auchenorrhynchan insects when it is not harbored in the cytoplasm of other endosymbionts. Our results highlight transovarial transmission mechanisms of bacteriome-associated symbionts in sap-feeding insects.}, }
@article {pmid32276327, year = {2020}, author = {Serteyn, L and Quaghebeur, C and Ongena, M and Cabrera, N and Barrera, A and Molina-Montenegro, MA and Francis, F and Ramírez, CC}, title = {Induced Systemic Resistance by a Plant Growth-Promoting Rhizobacterium Impacts Development and Feeding Behavior of Aphids.}, journal = {Insects}, volume = {11}, number = {4}, pages = {}, pmid = {32276327}, issn = {2075-4450}, abstract = {The effects of microorganisms on plant-insect interactions have usually been underestimated. While plant growth-promoting rhizobacteria (PGPR) are known to induce plant defenses, endosymbiotic bacteria hosted by herbivorous insects are often beneficial to the host. Here, we aimed to assess whether PGPR-induced defenses in broad bean plants impact the pea aphid, depending on its genotype and the presence of endosymbionts. We estimated aphid reproduction, quantified defense- and growth-related phytohormones by GC-MS, and measured different plant growth and physiology parameters, after PGPR treatment. In addition, we recorded the feeding behavior of aphids by electropenetrography. We found that the PGPR treatment of broad bean plants reduced the reproduction of one of the pea aphid clones. We highlighted a phenomenon of PGPR-induced plant defense priming, but no noticeable plant growth promotion. The main changes in aphid probing behavior were related to salivation events into phloem sieve elements. We suggest that the endosymbiont Hamiltonella defensa played a key role in plant-insect interactions, possibly helping aphids to counteract plant-induced resistance and allowing them to develop normally on PGPR-treated plants. Our results imply that plant- and aphid-associated microorganisms add greater complexity to the outcomes of aphid-plant interactions.}, }
@article {pmid32274814, year = {2020}, author = {Farré, EM}, title = {The brown clock: circadian rhythms in stramenopiles.}, journal = {Physiologia plantarum}, volume = {169}, number = {3}, pages = {430-441}, doi = {10.1111/ppl.13104}, pmid = {32274814}, issn = {1399-3054}, mesh = {Animals ; *Circadian Clocks ; Circadian Rhythm ; *Cyanobacteria ; Ecosystem ; *Stramenopiles ; }, abstract = {Circadian clocks allow organisms to anticipate environmental changes associated with the diurnal light/dark cycle. Circadian oscillators have been described in plants and green algae, cyanobacteria, animals and fungi, however, little is known about the circadian clocks of photosynthetic eukaryotes outside the green lineage. Stramenopiles are a diverse group of secondary endosymbionts whose plastid originated from a red alga. Photosynthetic stramenopiles, which include diatoms and brown algae, play key roles in biogeochemical cycles and are important components of marine ecosystems. Genome annotation efforts indicated the presence of a novel type of oscillator in these organisms and the first circadian clock component in a stramenopile has been recently discovered. This review summarizes the phenotypic characterization of circadian rhythms in stramenopiles and current efforts to determine the mechanisms of this 'brown clock'. The elucidation of this brown clock will enable a deeper understanding of the role of self-sustained oscillations in the adaptation to life in marine environments.}, }
@article {pmid32269557, year = {2020}, author = {Domínguez-Santos, R and Pérez-Cobas, AE and Artacho, A and Castro, JA and Talón, I and Moya, A and García-Ferris, C and Latorre, A}, title = {Unraveling Assemblage, Functions and Stability of the Gut Microbiota of Blattella germanica by Antibiotic Treatment.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {487}, pmid = {32269557}, issn = {1664-302X}, abstract = {Symbiosis between prokaryotes and eukaryotes is a widespread phenomenon that has contributed to the evolution of eukaryotes. In cockroaches, two types of symbionts coexist: an endosymbiont in the fat body (Blattabacterium), and a rich gut microbiota. The transmission mode of Blattabacterium is vertical, while the gut microbiota of a new generation is mainly formed by bacterial species present in feces. We have carried out a metagenomic analysis of Blattella germanica populations, treated and non-treated with two antibiotics (vancomycin and ampicillin) over two generations to (1) determine the core of bacterial communities and potential functions of the gut microbiota and (2) to gain insights into the mechanisms of resistance and resilience of the gut microbiota. Our results indicate that the composition and functions of the bacteria were affected by treatment, more severely in the case of vancomycin. Further results demonstrated that in an untreated second-generation population that comes from antibiotic-treated first-generation, the microbiota is not yet stabilized at nymphal stages but can fully recover in adults when feces of a control population were added to the diet. This signifies the existence of a stable core in either composition and functions in lab-reared populations. The high microbiota diversity as well as the observed functional redundancy point toward the microbiota of cockroach hindguts as a robust ecosystem that can recover from perturbations, with recovery being faster when feces are added to the diet.}, }
@article {pmid32244698, year = {2020}, author = {Xu, TT and Jiang, LY and Chen, J and Qiao, GX}, title = {Host Plants Influence the Symbiont Diversity of Eriosomatinae (Hemiptera: Aphididae).}, journal = {Insects}, volume = {11}, number = {4}, pages = {}, pmid = {32244698}, issn = {2075-4450}, abstract = {Eriosomatinae is a particular aphid group with typically heteroecious holocyclic life cycle, exhibiting strong primary host plant specialization and inducing galls on primary host plants. Aphids are frequently associated with bacterial symbionts, which can play fundamental roles in the ecology and evolution of their host aphids. However, the bacterial communities in Eriosomatinae are poorly known. In the present study, using high-throughput sequencing of the bacterial 16S ribosomal RNA gene, we surveyed the bacterial flora of eriosomatines and explored the associations between symbiont diversity and aphid relatedness, aphid host plant and geographical distribution. The microbiota of Eriosomatinae is dominated by the heritable primary endosymbiont Buchnera and several facultative symbionts. The primary endosymbiont Buchnera is expectedly the most abundant symbiont across all species. Six facultative symbionts were identified. Regiella was the most commonly identified facultative symbiont, and multiple infections of facultative symbionts were detected in the majority of the samples. Ordination analyses and statistical tests show that the symbiont community of aphids feeding on plants from the family Ulmaceae were distinguishable from aphids feeding on other host plants. Species in Eriosomatinae feeding on different plants are likely to carry different symbiont compositions. The symbiont distributions seem to be not related to taxonomic distance and geographical distance. Our findings suggest that host plants can affect symbiont maintenance, and will improve our understanding of the interactions between aphids, their symbionts and ecological conditions.}, }
@article {pmid32243856, year = {2020}, author = {Monnin, D and Jackson, R and Kiers, ET and Bunker, M and Ellers, J and Henry, LM}, title = {Parallel Evolution in the Integration of a Co-obligate Aphid Symbiosis.}, journal = {Current biology : CB}, volume = {30}, number = {10}, pages = {1949-1957.e6}, doi = {10.1016/j.cub.2020.03.011}, pmid = {32243856}, issn = {1879-0445}, mesh = {Animals ; Aphids/genetics/*microbiology ; Biological Evolution ; Genomics ; Host Microbial Interactions/genetics/physiology ; Serratia/genetics/*physiology ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Insects evolve dependence-often extreme-on microbes for nutrition. This includes cases in which insects harbor multiple endosymbionts that function collectively as a metabolic unit [1-5]. How do these dependences originate [6], and is there a predictable sequence of events leading to the integration of new symbionts? While co-obligate symbioses, in which hosts rely on multiple nutrient-provisioning symbionts, have evolved numerous times across sap-feeding insects, there is only one known case in aphids, involving Buchnera aphidicola and Serratia symbiotica in the Lachninae subfamily [7-9]. Here, we identify three additional independent transitions to the same co-obligate symbiosis in different aphids. Comparing recent and ancient associations allow us to investigate intermediate stages of metabolic and anatomical integration of Serratia. We find that these uniquely replicated evolutionary events support the idea that co-obligate associations initiate in a predictable manner-through parallel evolutionary processes. Specifically, we show how the repeated losses of the riboflavin and peptidoglycan pathways in Buchnera lead to dependence on Serratia. We then provide evidence of a stepwise process of symbiont integration, whereby dependence evolves first. Then, essential amino acid pathways are lost (at ∼30-60 mya), which coincides with the increased anatomical integration of the companion symbiont. Finally, we demonstrate that dependence can evolve ahead of specialized structures (e.g., bacteriocytes), and in one case with no direct nutritional basis. More generally, our results suggest the energetic costs of synthesizing nutrients may provide a unified explanation for the sequence of gene losses that occur during the evolution of co-obligate symbiosis.}, }
@article {pmid32240342, year = {2020}, author = {Guz, N and Arshad, M and Cagatay, NS and Dageri, A}, title = {High Prevalence of Pantoea in Diaphorina citri (Hemiptera: Liviidae): Vector of Citrus Huanglongbing Disease.}, journal = {Current microbiology}, volume = {77}, number = {8}, pages = {1525-1531}, pmid = {32240342}, issn = {1432-0991}, mesh = {Animals ; Bacterial Typing Techniques ; Citrus/*microbiology ; DNA, Bacterial/genetics ; Hemiptera/*microbiology ; Insect Vectors/*microbiology ; Nymph/microbiology ; Pantoea/*classification/isolation &amp; purification ; *Phylogeny ; Plant Diseases/microbiology/prevention &amp; control ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {As an important insect vector, Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae) transmits the pathogen 'Candidatus Liberibacter asiaticus' (CLas) that is associated with citrus greening also known as Huanglongbing (HLB) disease. The bacterial endosymbionts have a potential role in shaping the host range of insect herbivores and their performance on different host plants, which might affect the endosymbiont distribution in insect populations. Here, we detected and characterized Pantoea endosymbiont in nymph and adult ACP specimens collected from Citrus reticulata Blanco and Cordia myxa L. plants. The phylogenetic tree constructed using endosymbiotic bacteria 16S ribosomal RNA sequences indicated that Pantoea sp. was closely related to Mixta calida, sharing about 98% identity and was grouped with other Mixta and Pantoea endosymbionts. Our findings showed 100% and 92.3% infection of Pantoea in adults while 61.5% and 90% infection of Pantoea in nymphs collected from C. reticulata and C. myxa plants, respectively. Understanding the interaction of endosymbiotic bacteria with ACP associated with host plants could be useful for developing an effective management strategy for both ACP and HLB disease.}, }
@article {pmid32231650, year = {2020}, author = {Silvestri, A and Turina, M and Fiorilli, V and Miozzi, L and Venice, F and Bonfante, P and Lanfranco, L}, title = {Different Genetic Sources Contribute to the Small RNA Population in the Arbuscular Mycorrhizal Fungus Gigaspora margarita.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {395}, pmid = {32231650}, issn = {1664-302X}, abstract = {RNA interference (RNAi) is a key regulatory pathway of gene expression in almost all eukaryotes. This mechanism relies on short non-coding RNA molecules (sRNAs) to recognize in a sequence-specific manner DNA or RNA targets leading to transcriptional or post-transcriptional gene silencing. To date, the fundamental role of sRNAs in the regulation of development, stress responses, defense against viruses and mobile elements, and cross-kingdom interactions has been extensively studied in a number of biological systems. However, the knowledge of the "RNAi world" in arbuscular mycorrhizal fungi (AMF) is still limited. AMF are obligate mutualistic endosymbionts of plants, able to provide several benefits to their partners, from improved mineral nutrition to stress tolerance. Here we described the RNAi-related genes of the AMF Gigaspora margarita and characterized, through sRNA sequencing, its complex small RNAome, considering the possible genetic sources and targets of the sRNAs. G. margarita indeed is a mosaic of different genomes since it hosts endobacteria, RNA viruses, and non-integrated DNA fragments corresponding to mitovirus sequences. Our findings show that G. margarita is equipped with a complete set of RNAi-related genes characterized by the expansion of the Argonaute-like (AGO-like) gene family that seems a common trait of AMF. With regards to sRNAs, we detected populations of sRNA reads mapping to nuclear, mitochondrial, and viral genomes that share similar features (25-nt long and 5'-end uracil read enrichments), and that clearly differ from sRNAs of endobacterial origin. Furthermore, the annotation of nuclear loci producing sRNAs suggests the occurrence of different sRNA-generating processes. In silico analyses indicate that the most abundant G. margarita sRNAs, including those of viral origin, could target transcripts in the host plant, through a hypothetical cross-kingdom RNAi.}, }
@article {pmid32229918, year = {2019}, author = {Huston, DC}, title = {&lt;em&gt;Collastoma esotericum (Neodalyellida: Umagillidae), a new species of sipunculan-inhabiting rhabdocoel from Queensland, Australia.}, journal = {Zootaxa}, volume = {4701}, number = {6}, pages = {zootaxa.4701.6.5}, doi = {10.11646/zootaxa.4701.6.5}, pmid = {32229918}, issn = {1175-5334}, mesh = {Animals ; Australia ; Echinodermata ; Phylogeny ; *Platyhelminths ; Queensland ; }, abstract = {The Umagillidae Wahl, represent a group of endosymbiotic Platyhelminthes which inhabit two disparate invertebrate host groups, the echinoderms and sipunculans. Sipunculan-inhabiting umagillids are morphologically distinct from those inhabiting echinoderms and have traditionally been placed in a distinct genus and subfamily, Collastoma Dörler, and the Collastominae Wahl, respectively. Although molecular data are available for umagillid species inhabiting echinoids and holothurians, species inhabiting sipunculans have yet to be evaluated with molecular data. Collastoma esotericum n. sp. from the sipunculan Phascolosoma scolops (Selenka &amp; de Man) collected in Moreton Bay, southeast Queensland, Australia, is described. Phylogenetic analyses based on 18S rRNA gene sequences placed C. esotericum in a clade with species of the Umagillidae and the Provorticinae Luther, with strong support. However, within this clade the relationship of C. esotericum to the Umagillidae and Provorticinae was not resolved.}, }
@article {pmid32226612, year = {2020}, author = {Chen, CY and Mao, YB}, title = {Research advances in plant-insect molecular interaction.}, journal = {F1000Research}, volume = {9}, number = {}, pages = {}, pmid = {32226612}, issn = {2046-1402}, mesh = {Animals ; Herbivory ; *Insecta ; *Plants ; Signal Transduction ; }, abstract = {Acute and precise signal perception and transduction are essential for plant defense against insects. Insect elicitors-that is, the biologically active molecules from insects' oral secretion (which contains regurgitant and saliva), frass, ovipositional fluids, and the endosymbionts-are recognized by plants and subsequently induce a local or systematic defense response. On the other hand, insects secrete various types of effectors to interfere with plant defense at multiple levels for better adaptation. Jasmonate is a main regulator involved in plant defense against insects and integrates with multiple pathways to make up the intricate defense network. Jasmonate signaling is strictly regulated in plants to avoid the hypersensitive defense response and seems to be vulnerable to assault by insect effectors at the same time. Here, we summarize recently identified elicitors, effectors, and their target proteins in plants and discuss their underlying molecular mechanisms.}, }
@article {pmid34392954, year = {2020}, author = {Ciuca, L and Vismarra, A and Lebon, W and Beugnet, F and Morchon, R and Rinaldi, L and Cringoli, G and Kramer, L and Genchi, M}, title = {New insights into the biology, diagnosis and immune response to Dirofilaria repens in the canine host.}, journal = {Veterinary parasitology}, volume = {277S}, number = {}, pages = {100029}, doi = {10.1016/j.vpoa.2020.100029}, pmid = {34392954}, issn = {1873-2550}, abstract = {Dogs are the primary host for Dirofilaria repens, therefore it is mandatory to accurately diagnose the canine infection and to expand our current knowledge on parasite biology and the immune response of the infected host for a better prevention.Thus, the aim of the present study was to provide new insights from experimental infections of dogs with D. repens, focusing on the evaluation of: 1) the pre-patent period and 2) the antibody response against D. repens somatic antigens and against the Wolbachia endosymbiont. Briefly, on Day 0, twenty purpose-bred Beagle dogs were experimentally infected with 50 infective larvae (L3) of D. repens. Starting from Day 58 until the last day of the study (Day 281), blood samples were collected on a monthly basis for detection of antibodies against D. repens (Dr) and recombinant Wolbachia surface protein (rWSP) by non-commercial IgG-ELISAs. Additional samples were collected on Days 220, 245 and 281 for the detection of microfilariae (mff) using the modified Knott's test and biomolecular analysis, following two PCR protocols: Gioia et al. (2010; protocol A) and Rishniw et al. (2006- protocol B). The results were analysed by univariate statistical analyses using 2×2 contingency tables and K Cohen was calculated to assess the agreement among all the diagnostic techniques. Overall, the outcome of the study revealed that out of the 20 dogs experimentally infected with D. repens, 16 (80 %) were microfilaraemic, 17 (85 %) were positive at DNA detection in the blood, 18 (90 %) had D. repens antibodies and 16 (80 %) had Wolbachia antibodies on the last day of the study. The overall k agreement between Knott's and PCR protocol B was 0.442 (P=0.0001) and increased throughout the study, reaching 0.828 (P=0.0001) on Day 281. To the authors knowledge, this is only the second study reporting antibody response to D. repens somatic antigen in experimentally infected dogs. ELISA results showed that an antibody response develops before the onset of patency, and steadily increases with time. Results would suggest that the development of an immunological response to infection could lead to application in epidemiological studies, risk assessment and as an aid in the diagnostic approach in dogs, in particular for early infections without mff.}, }
@article {pmid33224472, year = {2018}, author = {Feranchuk, S and Belkova, N and Chernogor, L and Potapova, U and Belikov, S}, title = {The signs of adaptive mutations identified in the chloroplast genome of the algae endosymbiont of Baikal sponge.}, journal = {F1000Research}, volume = {7}, number = {}, pages = {1405}, pmid = {33224472}, issn = {2046-1402}, abstract = {BACKGROUND: Monitoring and investigating the ecosystem of the great lakes provide a thorough background when forecasting the ecosystem dynamics at a greater scale. Nowadays, changes in the Baikal lake biota require a deeper investigation of their molecular mechanisms. Understanding these mechanisms is especially important, as the endemic Baikal sponge disease may cause a degradation of the littoral ecosystem of the lake.<br><br>METHODS: The chloroplast genome fragment for the algae endosymbiont of the Baikal sponge was assembled from metagenomic sequencing data. The distributions of the polymorphic sites were obtained separately for the genome fragments from healthy, diseased and dead sponge tissues.<br><br>RESULTS: The distribution of polymorphic sites allows for the detection of the signs of extensive mutations in the chloroplasts isolated from the diseased sponge tissues. Additionally, the comparative analysis of chloroplast genome sequences suggests that the symbiotic algae from Baikal sponge is close to the Choricystis genus of unicellular algae.<br><br>CONCLUSIONS: Mutations observed in the chloroplast genome could be interpreted as signs of rapid adaptation processes in the symbiotic algae. The development of sponge disease is still expanding in Baikal, but an optimistic prognoses regarding a development of the disease is nevertheless considered.}, }
@article {pmid33474093, year = {2018}, author = {Sun, Y and Liang, Q and Sun, J and Yang, Y and Tao, J and Liang, J and Feng, D and Qiu, JW and Qian, PY}, title = {The mitochondrial genome of the deep-sea tubeworm Paraescarpia echinospica (Siboglinidae, Annelida) and its phylogenetic implications.}, journal = {Mitochondrial DNA. Part B, Resources}, volume = {3}, number = {1}, pages = {131-132}, pmid = {33474093}, issn = {2380-2359}, abstract = {Paraescarpia echinospica is a conspicuous annelid living in the cold seeps and hydrothermal vents of the Western Pacific region and relying on their endosymbiont bacteria as a source of energy and organic carbon. We report the complete mitochondrial genome of P. echinospica, which is 15,280 bp in length, containing 13 protein-coding genes, two ribosomal RNA genes, 22 tRNA genes and a putative control region. The overall base composition is AT-biased. The control region contains repeated nucleotide motifs. Phylogenetic analyses of the concatenated mitochondrial genes strongly support a sister relationship of P. echinospica with a clade containing Escarpia and Seepiophila.}, }
@article {pmid34595249, year = {2017}, author = {Kageyama, D}, title = {Quantification of Densities of Bacterial Endosymbionts of Insects by Real-time PCR.}, journal = {Bio-protocol}, volume = {7}, number = {19}, pages = {e2566}, pmid = {34595249}, issn = {2331-8325}, abstract = {Increased attention has been paid to the endosymbiotic bacteria of insects. Because most insect endosymbionts are uncultivable, quantitative PCR (qPCR) is a practical and convenient method to quantify endosymbiont titers. Here we report a protocol for real-time qPCR based on SYBR Green I fluorescence as well as some tips to prevent possible pitfalls.}, }
@article {pmid32669893, year = {2014}, author = {Higazi, TB and Geary, TG and Mackenzie, CD}, title = {Chemotherapy in the treatment, control, and elimination of human onchocerciasis.}, journal = {Research and reports in tropical medicine}, volume = {5}, number = {}, pages = {77-93}, pmid = {32669893}, issn = {1179-7282}, abstract = {Onchocerciasis treatment is one of the most positive stories in tropical medicine although major challenges remain to reaching the ultimate goal of disease elimination. Such challenges are to be expected when the therapeutic goal is to kill and safely remove a large multistage, efficient, metazoan infectious agent such as Onchocerca volvulus that has an exceptionally complicated relationship with its host. Successful control of onchocerciasis has often been hampered by host reactions following chemotherapy, that can sometimes cause significant tissue pathology. Presence of other filariae, particularly Loa loa, in endemic onchocerciasis-treatment areas also poses severe problems due to adverse reactions caused by drug-induced death of the coincident microfilariae of this usually clinically benign species. Although ivermectin has been very successful, there is a need to enhance the progress toward elimination of onchocerciasis; new drugs and their efficient use are keys to this. The permanent absence of Onchocerca microfilaridermia, defined as the lack of resurgence of skin microfilarial loads after treatment, is the ultimate characteristic of a useful new chemotherapeutic agent. Several drugs are under investigation to achieve this, including the reassessment of currently available and previously tested agents, such as the antibiotic, doxycycline, which targets the adult parasites through its anti-Wolbachia endosymbiont activity. Flubendazole, a benzimidazole derivative approved for treatment of human gastrointestinal nematodes, is also being considered for repurposing as a macrofilaricide to aid in the achievement of eradication. The managerial challenges existing at the population level also need to be addressed; these include drug-distribution fatigue, the need to include noncompliant people, civil unrest in endemic areas, political cross-border issues, restrictions of age and pregnancy, and complications due to integration with other treatment programs. It is likely that a panel of chemotherapeutic options, new and old, supported by strong and effective distribution systems will be the best way to address challenges of treatment and elimination of this infection. Future research should also address management of treatment and control, and consider how new treatment paradigms can be incorporated to meet time lines set for global elimination by 2025.}, }
@article {pmid34991281, year = {2005}, author = {Donner, SD and Skirving, WJ and Little, CM and Oppenheimer, M and Hoegh-Guldberg, O}, title = {Global assessment of coral bleaching and required rates of adaptation under climate change.}, journal = {Global change biology}, volume = {11}, number = {12}, pages = {2251-2265}, doi = {10.1111/j.1365-2486.2005.01073.x}, pmid = {34991281}, issn = {1365-2486}, abstract = {Elevated ocean temperatures can cause coral bleaching, the loss of colour from reef-building corals because of a breakdown of the symbiosis with the dinoflagellate Symbiodinium. Recent studies have warned that global climate change could increase the frequency of coral bleaching and threaten the long-term viability of coral reefs. These assertions are based on projecting the coarse output from atmosphere-ocean general circulation models (GCMs) to the local conditions around representative coral reefs. Here, we conduct the first comprehensive global assessment of coral bleaching under climate change by adapting the NOAA Coral Reef Watch bleaching prediction method to the output of a low- and high-climate sensitivity GCM. First, we develop and test algorithms for predicting mass coral bleaching with GCM-resolution sea surface temperatures for thousands of coral reefs, using a global coral reef map and 1985-2002 bleaching prediction data. We then use the algorithms to determine the frequency of coral bleaching and required thermal adaptation by corals and their endosymbionts under two different emissions scenarios. The results indicate that bleaching could become an annual or biannual event for the vast majority of the world's coral reefs in the next 30-50 years without an increase in thermal tolerance of 0.2-1.0°C per decade. The geographic variability in required thermal adaptation found in each model and emissions scenario suggests that coral reefs in some regions, like Micronesia and western Polynesia, may be particularly vulnerable to climate change. Advances in modelling and monitoring will refine the forecast for individual reefs, but this assessment concludes that the global prognosis is unlikely to change without an accelerated effort to stabilize atmospheric greenhouse gas concentrations.}, }
@article {pmid32213418, year = {2020}, author = {Chen, B and Yu, K and Qin, Z and Liang, J and Wang, G and Huang, X and Wu, Q and Jiang, L}, title = {Dispersal, genetic variation, and symbiont interaction network of heat-tolerant endosymbiont Durusdinium trenchii: Insights into the adaptive potential of coral to climate change.}, journal = {The Science of the total environment}, volume = {723}, number = {}, pages = {138026}, doi = {10.1016/j.scitotenv.2020.138026}, pmid = {32213418}, issn = {1879-1026}, mesh = {Animals ; *Anthozoa ; China ; Climate Change ; Coral Reefs ; Ecosystem ; Genetic Variation ; Hot Temperature ; }, abstract = {Global warming has degraded coral reef ecosystems worldwide. Some corals develop thermal tolerance by associating with heat-tolerant Symbiodiniaceae. Here, we studied the mechanisms surrounding the dispersal, genetic variation and symbionts interaction of heat-tolerant Durusdinium trenchii across 13° latitudes in the South China Sea (SCS), to explore the possible mechanisms underlying these changes. Our results showed that Durusdinium trenchii are widely distributed in the seawater from the SCS. Our analyses of microsatellite loci revealed that D. trenchii has a high genetic diversity in the SCS; STRUCTURE analysis indicated that D. trenchii can be divided into four populations within the SCS; There exist positive correlations between genetic variation and geographic isolation, average sea surface temperature (SST) and variations in SST. Network modelling inferences showed that D. trenchii is a key species in the Symbiodiniaceae communities in the tropical SCS and contributes the greatest number of co-exclusion relationships. These results indicated that D. trenchii can affect the rare Symbiodiniaceae community. The long lifespan and the monsoon-driven ocean currents have shaped the wide distribution of D. trenchii. But low SST limits the ability of D. trenchii to establish stable symbioses with coral in the subtropical habitats. Geographical isolation and SST have shaped significant genetic variation of D.trenchii around the SCS. Our data reveals the biogeography and genetic population characteristics of D. trenchii in the Indo-Pacific region, and suggests that heat-tolerance and high genetic diversity of D. trenchii aid the corals with their adaptation to climate change.}, }
@article {pmid32211166, year = {2020}, author = {Paredes-Montero, JR and Zia-Ur-Rehman, M and Hameed, U and Haider, MS and Herrmann, HW and Brown, JK}, title = {Genetic variability, community structure, and horizontal transfer of endosymbionts among three Asia II-Bemisia tabaci mitotypes in Pakistan.}, journal = {Ecology and evolution}, volume = {10}, number = {6}, pages = {2928-2943}, pmid = {32211166}, issn = {2045-7758}, abstract = {Endosymbionts associated with the whitefly Bemisia tabaci cryptic species are known to contribute to host fitness and environmental adaptation. The genetic diversity and population complexity were investigated for endosymbiont communities of B. tabaci occupying different micro-environments in Pakistan. Mitotypes of B. tabaci were identified by comparative sequence analysis of the mitochondria cytochrome oxidase I (mtCOI) gene sequence. Whitefly mitotypes belonged to the Asia II-1, -5, and -7 mitotypes of the Asia II major clade. The whitefly-endosymbiont communities were characterized based on 16S ribosomal RNA operational taxonomic unit (OTU) assignments, resulting in 43 OTUs. Most of the OTUs occurred in the Asia II-1 and II-7 mitotypes (r [2] = .9, p < .005), while the Asia II-5 microbiome was less complex. The microbiome OTU groups were mitotype-specific, clustering with a basis in phylogeographical distribution and the corresponding ecological niche of their whitefly host, suggesting mitotype-microbiome co-adaptation. The primary endosymbiont Portiera was represented by a single, highly homologous OTU (0%-0.67% divergence). Two of six Arsenophonus OTUs were uniquely associated with Asia II-5 and -7, and one occurred exclusively in Asia II-1, two only in Asia II-5, and one in both Asia II-1 and -7. Four other secondary endosymbionts, Cardinium, Hemipteriphilus, Rickettsia, and Wolbachia OTUs, were found at ≤29% frequencies. The most prevalent Arsenophonus OTU was found in all three Asia II mitotypes (55% frequency), whereas the same strain of Cardinium and Wolbachia was found in both Asia II-1 and -5, and a single Hemipteriphilus OTU occurred in Asia II-1 and -7. This pattern is indicative of horizontal transfer, suggestive of a proximity between mitotypes sufficient for gene flow at overlapping mitotype ecological niches.}, }
@article {pmid32209690, year = {2020}, author = {Frost, CL and Siozios, S and Nadal-Jimenez, P and Brockhurst, MA and King, KC and Darby, AC and Hurst, GDD}, title = {The Hypercomplex Genome of an Insect Reproductive Parasite Highlights the Importance of Lateral Gene Transfer in Symbiont Biology.}, journal = {mBio}, volume = {11}, number = {2}, pages = {}, pmid = {32209690}, issn = {2150-7511}, support = {BB/L024209/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacteriophages/genetics ; Gammaproteobacteria/*genetics ; *Gene Transfer, Horizontal ; *Genome, Bacterial ; Genomics ; *Interspersed Repetitive Sequences ; Phylogeny ; Repetitive Sequences, Nucleic Acid ; Symbiosis/*genetics ; Wasps/*microbiology ; }, abstract = {Mobile elements-plasmids and phages-are important components of microbial function and evolution via traits that they encode and their capacity to shuttle genetic material between species. We here report the unusually rich array of mobile elements within the genome of Arsenophonus nasoniae, the son-killer symbiont of the parasitic wasp Nasonia vitripennis This microbe's genome has the highest prophage complement reported to date, with over 50 genomic regions that represent either intact or degraded phage material. Moreover, the genome is predicted to include 17 extrachromosomal genetic elements, which carry many genes predicted to be important at the microbe-host interface, derived from a diverse assemblage of insect-associated gammaproteobacteria. In our system, this diversity was previously masked by repetitive mobile elements that broke the assembly derived from short reads. These findings suggest that other complex bacterial genomes will be revealed in the era of long-read sequencing.IMPORTANCE The biology of many bacteria is critically dependent on genes carried on plasmid and phage mobile elements. These elements shuttle between microbial species, thus providing an important source of biological innovation across taxa. It has recently been recognized that mobile elements are also important in symbiotic bacteria, which form long-lasting interactions with their host. In this study, we report a bacterial symbiont genome that carries a highly complex array of these elements. Arsenophonus nasoniae is the son-killer microbe of the parasitic wasp Nasonia vitripennis and exists with the wasp throughout its life cycle. We completed its genome with the aid of recently developed long-read technology. This assembly contained over 50 chromosomal regions of phage origin and 17 extrachromosomal elements within the genome, encoding many important traits at the host-microbe interface. Thus, the biology of this symbiont is enabled by a complex array of mobile elements.}, }
@article {pmid32207826, year = {2020}, author = {Guz, N and Arshad, M and Cagatay, NS and Dageri, A and Ullah, MI}, title = {Detection of Wolbachia (Rickettsiales: Anaplasmataceae) and Candidatus Liberibacter asiaticus (Rhizobiales: Rhizobiaceae) Associated With Diaphorina citri (Hemiptera: Liviidae) Collected From Citrus reticulata (Sapindales: Rutaceae) and Alternate Host, Cordia myxa (Boraginales: Boraginaceae).}, journal = {Journal of economic entomology}, volume = {113}, number = {3}, pages = {1486-1492}, doi = {10.1093/jee/toaa043}, pmid = {32207826}, issn = {1938-291X}, mesh = {*Anaplasmataceae ; Animals ; *Boraginaceae ; *Citrus ; *Cordia ; *Hemiptera ; Plant Diseases ; *Rhizobiaceae ; Rickettsiales ; *Rutaceae ; *Wolbachia ; }, abstract = {The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is an important insect pest of the citrus crop worldwide. It vectors the pathogen 'Candidatus Liberibacter asiaticus' (CLas) that causes a serious disease known as citrus greening. Here, we tested the infection frequency of Wolbachia and CLas from 100 D. citri individuals collected from two host plants belonging to families Rutaceae (Citrus reticulata Blanco) and Boraginaceae (Cordia myxa L.) using molecular methods. The following trend of endosymbionts infection in adult D. citri was found; 85.4% (35/41) by Wolbachia, and 19.5% (8/41) by CLas collected from C. reticulata plants and 65.4% (17/26) by Wolbachia, and 15.4% (4/26) by CLas in case of C. myxa plant. However, 61.5% (8/13) nymphs collected from C. reticulata and 20.0% (4/20) collected from C. myxa plants were infected by Wolbachia, while no nymph was infected by CLas collected from either host plants. Findings from this work represent the first report of CLas presence in D. citri feeding on C. myxa plants. By studying the presence of CLas with other endosymbiotic bacteria, future basic and applied research to develop control strategies can be prioritized.}, }
@article {pmid32191724, year = {2020}, author = {Dionysopoulou, NK and Papanastasiou, SA and Kyritsis, GA and Papadopoulos, NT}, title = {Effect of host fruit, temperature and Wolbachia infection on survival and development of Ceratitis capitata immature stages.}, journal = {PloS one}, volume = {15}, number = {3}, pages = {e0229727}, pmid = {32191724}, issn = {1932-6203}, mesh = {Animals ; Ceratitis capitata/*growth &amp; development/*microbiology ; Fruit/*parasitology ; Larva/growth &amp; development ; *Life Cycle Stages ; Proportional Hazards Models ; Pupa/growth &amp; development ; Survival Analysis ; *Temperature ; Wolbachia/*physiology ; }, abstract = {The Mediterranean fruit fly, Ceratitis capitata (Diptera: Tephritidae), holds an impressive record of successful invasions promoted by the growth and development of international fruit trade. Hence, survival of immatures within infested fruit that are subjected to various conditions during transportation seems to be a crucial feature that promotes invasion success. Wolbachia pipientis is a common endosymbiont of insects and other arthropods generating several biological effects on its hosts. Existing information report the influence of Wolbachia on the fitness traits of insect host species, including the Mediterranean fruit fly. However, little is known regarding effects of Wolbachia infection on immature development in different host fruits and temperatures. This study was conducted to determine the development and survival of immature stages of four different Mediterranean fruit fly populations, either infected or uninfected with Wolbachia, in two hosts (apples, bitter oranges) under three constant temperatures (15, 25 and 30°C), constant relative humidity (45-55 ± 5%), and a photoperiod of 14L:10D. Our findings demonstrate both differential response of two fruit fly lines to Wolbachia infection and differential effects of the two Wolbachia strains on the same Mediterranean fruit fly line. Larva-to-pupa and larva-to-adult survival followed similar patterns and varied a lot among the four medfly populations, the two host fruits and the different temperatures. Pupation rates and larval developmental time were higher for larvae implanted in apples compared to bitter oranges. The survival rates of wildish medflies were higher than those of the laboratory adapted ones, particularly in bitter oranges. The Wolbachia infected medflies, expressed lower survival rates and higher developmental times, especially the wCer4 infected line. High temperatures constrained immature development and were lethal for the Wolbachia infected wCer4 medfly line. Lower temperatures inferred longer developmental times to immature stages of all medfly populations tested, in both host fruits. Implications on the ecology and survival of the fly in nature are discussed.}, }
@article {pmid32188733, year = {2020}, author = {Mahar, JE and Shi, M and Hall, RN and Strive, T and Holmes, EC}, title = {Comparative Analysis of RNA Virome Composition in Rabbits and Associated Ectoparasites.}, journal = {Journal of virology}, volume = {94}, number = {11}, pages = {}, pmid = {32188733}, issn = {1098-5514}, mesh = {Animals ; *Astroviridae/classification/genetics ; *Genome, Viral ; *Hemorrhagic Disease Virus, Rabbit/classification/genetics ; *Myxoma virus/classification/genetics ; RNA, Viral/*genetics ; Rabbits ; Siphonaptera/*virology ; }, abstract = {Ectoparasites play an important role in virus transmission among vertebrates. Little, however, is known about the nature of those viruses that pass between invertebrates and vertebrates. In Australia, flies and fleas support the mechanical transmission of two viral biological controls against wild rabbits-rabbit hemorrhagic disease virus (RHDV) and myxoma virus. We compared virome compositions in rabbits and these ectoparasites, sequencing total RNA from multiple tissues and gut contents of wild rabbits, fleas collected from these rabbits, and flies trapped sympatrically. Meta-transcriptomic analyses identified 50 novel viruses from multiple RNA virus families. Rabbits and their ectoparasites were characterized by markedly different viromes, with virus abundance greatest in flies. Although viral contigs from six virus families/groups were found in both rabbits and ectoparasites, they clustered in distinct host-dependent lineages. A novel calicivirus and a picornavirus detected in rabbit cecal content were vertebrate specific; the newly detected calicivirus was distinct from known rabbit caliciviruses, while the picornavirus clustered with sapeloviruses. Several picobirnaviruses were also identified that fell in diverse phylogenetic positions, compatible with the idea that they are associated with bacteria. Further comparative analysis revealed that the remaining viruses found in rabbits, and all those from ectoparasites, were likely associated with invertebrates, plants, and coinfecting endosymbionts. While no full genomes of vertebrate-associated viruses were detected in ectoparasites, small numbers of reads from rabbit astrovirus, RHDV, and other lagoviruses were present in flies. This supports a role for flies in the mechanical transmission of RHDV, while their involvement in astrovirus transmission merits additional exploration.IMPORTANCE Ectoparasites play an important role in the transmission of many vertebrate-infecting viruses, including Zika and dengue viruses. Although it is becoming increasingly clear that invertebrate species harbor substantial virus diversity, it is unclear how many of the viruses carried by invertebrates have the potential to infect vertebrate species. We used the European rabbit (Oryctolagus cuniculus) as a model species to compare virome compositions in a vertebrate host and known associated ectoparasite mechanical vectors, in this case, fleas and blowflies. In particular, we aimed to infer the extent of viral transfer between these distinct types of host. Our analysis revealed that despite extensive viral diversity in both rabbits and associated ectoparasites, and the close interaction of these vertebrate and invertebrate species, biological viral transmission from ectoparasites to vertebrate species is rare. We did, however, find evidence to support the idea of a role of blowflies in transmitting viruses without active replication in the insect.}, }
@article {pmid32185832, year = {2020}, author = {García-Del Portillo, F}, title = {Building peptidoglycan inside eukaryotic cells: A view from symbiotic and pathogenic bacteria.}, journal = {Molecular microbiology}, volume = {113}, number = {3}, pages = {613-626}, pmid = {32185832}, issn = {1365-2958}, mesh = {Bacteria/metabolism ; Bacterial Infections/metabolism ; Bacterial Proteins/metabolism ; Cell Wall/metabolism ; Eukaryotic Cells/*microbiology ; Host-Pathogen Interactions/physiology ; Humans ; Peptidoglycan/*biosynthesis/*metabolism ; Symbiosis ; Virulence ; }, abstract = {The peptidoglycan (PG), as the exoskeleton of most prokaryotes, maintains a defined shape and ensures cell integrity against the high internal turgor pressure. These important roles have attracted researchers to target PG metabolism in order to control bacterial infections. Most studies, however, have been performed in bacteria grown under laboratory conditions, leading to only a partial view on how the PG is synthetized in natural environments. As a case in point, PG metabolism and its regulation remain poorly understood in symbiotic and pathogenic bacteria living inside eukaryotic cells. This review focuses on the PG metabolism of intracellular bacteria, emphasizing the necessity of more in vivo studies involving the analysis of enzymes produced in the intracellular niche and the isolation of PG from bacteria residing within eukaryotic cells. The review also points to persistent infections caused by some intracellular bacterial pathogens and the extent at which the PG could contribute to establish such physiological state. Based on recent evidences, I speculate on the idea that certain structural features of the PG may facilitate attenuation of intracellular growth. Lastly, I discuss recent findings in endosymbionts supporting a cooperation between host and bacterial enzymes to assemble a mature PG.}, }
@article {pmid32185527, year = {2020}, author = {Kuroiwa, T and Ohnuma, M and Imoto, Y and Yagisawa, F and Misumi, O and Nagata, N and Kuroiwa, H}, title = {Evolutionary significance of the ring-like plastid nucleus in the primitive red alga Cyanidioschyzon merolae as revealed by drying.}, journal = {Protoplasma}, volume = {257}, number = {4}, pages = {1069-1078}, doi = {10.1007/s00709-020-01496-y}, pmid = {32185527}, issn = {1615-6102}, mesh = {Biological Evolution ; Cell Nucleus/*genetics ; Plastids/*genetics ; Rhodophyta/*genetics ; }, abstract = {Primary plastids originated from a free-living cyanobacterial ancestor and possess their own genomes-probably a few DNA copies. These genomes, which are organized in centrally located plastid nuclei (CN-type pt-nuclei), are produced from preexisting plastids by binary division. Ancestral algae with a CN-type pt-nucleus diverged and evolved into two basal eukaryotic lineages: red algae with circular (CL-type) pt-nuclei and green algae with scattered small (SN-type) pt-nuclei. Although the molecular dynamics of pt-nuclei in green algae and plants are now being analyzed, the process of the conversion of the original algae with a CN-type pt-nucleus to red algae with a CL-type one has not been studied. Here, we show that the CN-type pt-nucleus in the primitive red alga Cyanidioschyzon merolae can be changed to the CL-type by application of drying to produce slight cell swelling. This result implies that CN-type pt-nuclei are produced by compact packing of CL-type ones, which suggests that a C. merolae-like alga was the original progenitor of the red algal lineage. We also observed that the CL-type pt-nucleus has a chain-linked bead-like structure. Each bead is most likely a small unit of DNA, similar to CL-type pt-nuclei in brown algae. Our results thus suggest a C. merolae-like alga as the candidate for the secondary endosymbiont of brown algae.}, }
@article {pmid32175575, year = {2020}, author = {Lavy, O and Gophna, U and Gefen, E and Ayali, A}, title = {Dynamics of bacterial composition in the locust reproductive tract are affected by the density-dependent phase.}, journal = {FEMS microbiology ecology}, volume = {96}, number = {4}, pages = {}, doi = {10.1093/femsec/fiaa044}, pmid = {32175575}, issn = {1574-6941}, mesh = {Animals ; Bacteria/genetics ; Female ; *Grasshoppers/genetics ; Population Density ; RNA, Ribosomal, 16S/genetics ; }, abstract = {The important role that locust gut bacteria play in their host biology is well accepted. Among other roles, gut bacteria are suggested to be involved in the locust swarming phenomenon. In addition, in many insect orders, the reproductive system is reported to serve as a vector for trans-generation bacterial inoculation. Knowledge of the bacterial composition of the locust reproductive tract is, however, practically absent. Here we characterized the reproductive system bacterial composition of gregarious and solitary females. We investigated its temporal dynamics and how it interacts with the locust phase, by comparative sampling and 16S rRNA amplicon sequencing. We revealed that the bacterial composition of the locust female reproductive tract is mostly constructed of three core genera: Micrococcus, Acinetobacter and Staphylococcus. While solitary females maintained a consistent bacterial composition, in the gregarious phase this consortium demonstrated large temporal shifts, mostly manifested by Brevibacterium blooms. These data are in accord with our previous report on the dynamics of locust hindgut bacterial microbiota, further indicating that locust endosymbionts are affected by their host population density. These newly understood dynamics may have implications beyond their contribution to our knowledge of locust ecology, as aggregation and mass migration are prevalent phenomena across many migrating animals.}, }
@article {pmid32174906, year = {2020}, author = {van den Bosch, TJM and Welte, CU}, title = {The Microbial Diversity of Cabbage Pest Delia radicum Across Multiple Life Stages.}, journal = {Frontiers in microbiology}, volume = {11}, number = {}, pages = {315}, pmid = {32174906}, issn = {1664-302X}, abstract = {The cabbage root fly Delia radicum is a worldwide pest that causes yield losses of many common cabbage crops. The bacteria associated with D. radicum are suggested to influence the pest status of their host. In this study, we characterized insect-associated bacteria of D. radicum across multiple life stages and of their diet plant (turnip, Brassica rapa subsp. rapa) by sequencing the V3-V4 region of 16S rRNA genes using the Illumina MiSeq platform. In total, over 1.2M paired-end reads were obtained, identifying 1006 bacterial amplicon sequence variants (ASVs) in samples obtained from the eggs, larvae, pupae and adults of D. radicum, as well as turnips that were either fresh or infested with D. radicum larvae. The microbial community in D. radicum was dominated by Wolbachia, a common endosymbiont of arthropods which we found in all of the investigated insect samples, with the pupal stage having the highest relative abundance. Moderate amounts of Firmicutes were found only in adult D. radicum flies, but not in previous life stages. Actinobacteria were mostly found on the eggs and on the skin of fresh plants on which the eggs were deposited. These plants also harbored a large amount of Pseudomonas. The bacterial diversity of the healthy turnip was low, whereas the microbial community of decaying turnips that were heavily infested by D. radicum larvae and showing symptoms of advanced soft rot was characterized by a high bacterial diversity. Taken together, this work provides insights into the bacterial communities associated with the cabbage pest D. radicum and its associated disease symptoms.}, }
@article {pmid32168905, year = {2020}, author = {Rossitto De Marchi, B and Smith, HA}, title = {Bacterial Endosymbiont Diversity Among Bemisia tabaci (Hemiptera: Aleyrodidae) Populations in Florida.}, journal = {Insects}, volume = {11}, number = {3}, pages = {}, pmid = {32168905}, issn = {2075-4450}, abstract = {The sweetpotato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is a pest of many economically important agricultural crops and a vector of plant viruses. Bemisia tabaci harbors facultative endosymbiont species that have been implicated in pest status, including tolerance to insecticides, virus transmission efficiency and tolerance to high-temperatures. The facultative endosymbionts reported in B. tabaci include Arsenophonus, Hamiltonella, Wolbachia, Cardinium, Fritschea and Rickettsia. We collected whitefly populations from weed and crop hosts in south Florida and identified the whitefly species as well as the facultative endosymbionts present in these populations by molecular analysis. In addition, a phylogenetic analysis of whiteflies and their endosymbionts was performed. The only facultative endosymbionts found among the B. tabaci populations collected in Florida were Hamiltonella and Rickettsia. The phylogenetic analysis revealed the low genetic diversity of whiteflies and their endosymbionts. Additionally, the phylogenetic tree clustered Rickettsia from Florida in the R1 genetic group. The results will aid to understand the role of the bacterial endosymbionts in the whitefly host.}, }
@article {pmid32161299, year = {2020}, author = {Claar, DC and Tietjen, KL and Cox, KD and Gates, RD and Baum, JK}, title = {Chronic disturbance modulates symbiont (Symbiodiniaceae) beta diversity on a coral reef.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {4492}, pmid = {32161299}, issn = {2045-2322}, mesh = {*Biodiversity ; *Coral Reefs ; *Dinoflagellida ; *Ecosystem ; Human Activities ; Humans ; *Symbiosis ; }, abstract = {Chronic disturbance can disrupt ecological interactions including the foundational symbiosis between reef-building corals and the dinoflagellate family Symbiodiniaceae. Symbiodiniaceae are photosynthetic endosymbionts necessary for coral survival, but many Symbiodiniaceae can also be found free-living in the environment. Since most coral species acquire new Symbiodiniaceae from the environment each generation, free-living Symbiodiniaceae represent important pools for coral symbiont acquisition. Yet, little is known about the diversity of, or impacts of disturbance on, free-living Symbiodiniaceae. To determine how chronic and pulse disturbances influence Symbiodiniaceae communities, we sampled three reef habitat compartments - sediment, water, and coral (Pocillopora grandis, Montipora aequituberculata, Porites lobata) - at sites exposed to different levels of chronic anthropogenic disturbance, before, during, and after a major storm. Almost no (4%) Symbiodiniaceae amplicon sequence variants (ASVs) were found in all three compartments, and over half were found uniquely in coral. Sites experiencing chronic disturbance were typically associated with higher symbiont beta diversity (i.e., variability and turnover) across reef habitat compartments. Pulse stress, from the storm, exhibited some influence on symbiont beta diversity but the effect was inconsistent. This suggests that in this ecosystem, the effects of chronic disturbance are more prominent than temporal variability during a pulse disturbance for shaping symbiont communities.}, }
@article {pmid32157725, year = {2020}, author = {Speijer, D}, title = {Debating Eukaryogenesis-Part 2: How Anachronistic Reasoning Can Lure Us into Inventing Intermediates.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {42}, number = {5}, pages = {e1900153}, doi = {10.1002/bies.201900153}, pmid = {32157725}, issn = {1521-1878}, mesh = {Archaea/genetics ; *Biological Evolution ; *Eukaryota ; Eukaryotic Cells ; Phylogeny ; Symbiosis ; }, abstract = {Eukaryotic origins are inextricably linked with the arrival of a pre-mitochondrion of alphaproteobacterial-like ancestry. However, the nature of the "host" cell and the mode of entry are subject to heavy debate. It is becoming clear that the mutual adaptation of a relatively simple, archaeal host and the endosymbiont has been the defining influence at the beginning of the eukaryotic lineage; however, many still resist such symbiogenic models. In part 1, it is posited that a symbiotic stage before uptake ("pre-symbiosis") seems essential to allow further metabolic integration of the two partners ending in endosymbiosis. Thus, the author argued against phagocytic mechanisms (in which the bacterium is prey or parasite) as the mode of entry. Such positions are still broadly unpopular. Here it is explained why. Evolutionary thinking, especially in the case of eukaryogenesis, is still dominated by anachronistic reasoning, in which highly derived protozoan organisms are seen as in some way representative of intermediate steps during eukaryotic evolution, hence poisoning the debate. This reasoning reflects a mind-set that ignores that Darwinian evolution is a fundamentally historic process. Numerous examples of this kind of erroneous reasoning are given, and some basic precautions against its use are formulated. Also see the video abstract here https://youtu.be/ekqtNleVJpU.}, }
@article {pmid32150959, year = {2020}, author = {Rincón-Tomás, B and González, FJ and Somoza, L and Sauter, K and Madureira, P and Medialdea, T and Carlsson, J and Reitner, J and Hoppert, M}, title = {Siboglinidae Tubes as an Additional Niche for Microbial Communities in the Gulf of Cádiz-A Microscopical Appraisal.}, journal = {Microorganisms}, volume = {8}, number = {3}, pages = {}, pmid = {32150959}, issn = {2076-2607}, abstract = {Siboglinids were sampled from four mud volcanoes in the Gulf of Cádiz (El Cid MV, Bonjardim MV, Al Gacel MV, and Anastasya MV). These invertebrates are characteristic to cold seeps and are known to host chemosynthetic endosymbionts in a dedicated trophosome organ. However, little is known about their tube as a potential niche for other microorganisms. Analyses by scanning and transmission electron microscopy showed dense biofilms on the tube in Al Gacel MV and Anastasya MV specimens by prokaryotic cells. Methanotrophic bacteria were the most abundant forming these biofilms as further supported by 16S rRNA sequence analysis. Furthermore, elemental analyses with electron microscopy and energy-dispersive X-ray spectroscopy point to the mineralization and silicification of the tube, most likely induced by the microbial metabolisms. Bacterial and archaeal 16S rRNA sequence libraries revealed abundant microorganisms related to these siboglinid specimens and certain variations in microbial communities among samples. Thus, the tube remarkably increases the microbial biomass related to the worms and provides an additional microbial niche in deep-sea ecosystems.}, }
@article {pmid32144639, year = {2020}, author = {Duan, DY and Liu, GH and Cheng, TY}, title = {Microbiome analysis of the saliva and midgut from partially or fully engorged female adult Dermacentor silvarum ticks in China.}, journal = {Experimental &amp; applied acarology}, volume = {80}, number = {4}, pages = {543-558}, pmid = {32144639}, issn = {1572-9702}, mesh = {Animals ; China ; Dermacentor/*microbiology ; Female ; Gastrointestinal Tract/*microbiology ; *Microbiota ; RNA, Ribosomal, 16S ; Saliva/*microbiology ; }, abstract = {Dermacentor silvarum is widely distributed in northern China and transmits several pathogens that cause diseases in humans and domestic animals. We analysed the comprehensive bacterial community of the saliva and midgut from partially and fully engorged female adult D. silvarum. Dermacentor silvarum samples were collected from Guyuan, China. Bacterial DNA was extracted from the saliva and midgut contents of partially or fully engorged female adult D. silvarum. Sequencing of the V3-V4 hypervariable regions of the 16S rRNA genes was performed using the IonS5[TM]XL platform. The bacterial diversity in saliva was higher than in the midgut. The bacterial diversity of saliva from fully engorged ticks was greater than in partially engorged tick saliva. The bacterial diversity in midguts from partially engorged ticks was greater than in fully engorged tick midguts. Proteobacteria was the most dominant bacterial phylum in all of the samples. Twenty-nine bacterial genera were detected in all of the samples. Rickettsia, Anaplasma, and Stenotrophomonas were the main genera. The symbionts Coxiella, Arsenophonus, and Wolbachia were also detected in all of the samples. Eight bacterial species were identified in all of the experimental samples. Anaplasma marginale was reported for the first time in D. silvarum.}, }
@article {pmid32140734, year = {2020}, author = {Ebrahimi, H and Siavoshi, F and Heydari, S and Sarrafnejad, A and Saniee, P}, title = {Yeast engineered translucent cell wall to provide its endosymbiont cyanobacteria with light.}, journal = {Archives of microbiology}, volume = {202}, number = {6}, pages = {1317-1325}, pmid = {32140734}, issn = {1432-072X}, mesh = {Candida tropicalis/*genetics/*ultrastructure ; Cell Wall/*genetics/*ultrastructure ; Cyanobacteria/*physiology ; Genes, Bacterial/genetics ; Microscopy, Electron, Transmission ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Vacuoles/*microbiology/ultrastructure ; }, abstract = {In this study, relationship between translucent property of yeast cell wall and occurrence of cyanobacteria inside the yeast vacuole was examined. Microscopic observations on fruit yeast Candida tropicalis showed occurrence of bacterium-like bodies inside the yeast vacuole. Appearance of vacuoles as distinct cavities indicated the perfect harvesting of light by the yeast's cell wall. Transmission electron microscopy observation showed electron-dense outer and electron-lucent inner layers in yeast cell wall. Cyanobacteria-specific 16S rRNA gene was amplified from total DNA of yeast. Cultivation of yeast in distilled water led to excision of intracellular bacteria which grew on cyanobacteria-specific medium. Examination of wet mount and Gram-stained preparations of excised bacteria showed typical bead-like trichomes. Amplification of cyanobacteria-specific genes, 16S rRNA, cnfR and dxcf, confirmed bacterial identity as Leptolyngbya boryana. These results showed that translucent cell wall of yeast has been engineered through evolution for receiving light for vital activities of cyanobacteria.}, }
@article {pmid32140238, year = {2020}, author = {Wang, X and Ding, J and Lin, S and Liu, D and Gu, T and Wu, H and Trigiano, RN and McAvoy, R and Huang, J and Li, Y}, title = {Evolution and roles of cytokinin genes in angiosperms 2: Do ancient CKXs play housekeeping roles while non-ancient CKXs play regulatory roles?.}, journal = {Horticulture research}, volume = {7}, number = {}, pages = {29}, pmid = {32140238}, issn = {2662-6810}, abstract = {Cytokinin oxidase/dehydrogenase (CKX) is a key enzyme responsible for the degradation of endogenous cytokinins. However, the origins and roles of CKX genes in angiosperm evolution remain unclear. Based on comprehensive bioinformatic and transgenic plant analyses, we demonstrate that the CKXs of land plants most likely originated from an ancient chlamydial endosymbiont during primary endosymbiosis. We refer to the CKXs retaining evolutionarily ancient characteristics as "ancient CKXs" and those that have expanded and functionally diverged in angiosperms as "non-ancient CKXs". We show that the expression of some non-ancient CKXs is rapidly inducible within 15 min upon the dehydration of Arabidopsis, while the ancient CKX (AtCKX7) is not drought responsive. Tobacco plants overexpressing a non-ancient CKX display improved oxidative and drought tolerance and root growth. Previous mutant studies have shown that non-ancient CKXs regulate organ development, particularly that of flowers. Furthermore, ancient CKXs preferentially degrade cis-zeatin (cZ)-type cytokinins, while non-ancient CKXs preferentially target N[6]-(Δ[2]-isopentenyl) adenines (iPs) and trans-zeatins (tZs). Based on the results of this work, an accompanying study (Wang et al. 10.1038/s41438-019-0211-x) and previous studies, we hypothesize that non-ancient CKXs and their preferred substrates of iP/tZ-type cytokinins regulate angiosperm organ development and environmental stress responses, while ancient CKXs and their preferred substrates of cZs play a housekeeping role, which echoes the conclusions and hypothesis described in the accompanying report (Wang, X. et al. Evolution and roles of cytokinin genes in angiosperms 1: Doancient IPTs play housekeeping while non-ancient IPTs play regulatory roles? Hortic Res7, (2020). 10.1038/s41438-019-0211-x).}, }
@article {pmid32138145, year = {2020}, author = {Bubici, G and Prigigallo, MI and Garganese, F and Nugnes, F and Jansen, M and Porcelli, F}, title = {First Report of Aleurocanthus spiniferus on Ailanthus altissima: Profiling of the Insect Microbiome and MicroRNAs.}, journal = {Insects}, volume = {11}, number = {3}, pages = {}, pmid = {32138145}, issn = {2075-4450}, abstract = {We report the first occurrence of the orange spiny whitefly (Aleurocanthus spiniferus; OSW) on the tree of heaven (Ailanthus altissima) in Bari, Apulia region, Italy. After our first observation in 2016, the infestation recurred regularly during the following years and expanded to the neighboring trees. Since then, we have also found the insect on numerous patches of the tree of heaven and other plant species in the Bari province. Nevertheless, the tree of heaven was not particularly threatened by the insect, so that a possible contribution by OSW for the control of such an invasive plant cannot be hypothesized hitherto. This work was also aimed at profiling the microbiome of OSW feeding on A. altissima. For this purpose, we used the denaturing gradient gel electrophoresis (DGGE) and the deep sequencing of small RNAs (sRNAs). Both techniques unveiled the presence of "Candidatus Portiera" (primary endosymbiont), Wolbachia sp. and Rickettsia sp., endosymbionts already reported for other Aleyrodidae. Deep sequencing data were analyzed by four computational pipelines in order to understand the reliability of the detection of fungi, bacteria, and viruses: Kraken, Kaiju, Velvet, and VelvetOptimiser. Some contigs assembled by Velvet or VelvetOptimiser were associated with insects, but not necessarily in the Aleurocanthus genus or Aleyrodidae family, suggesting the non-specificity of sRNAs or possible traces of parasitoids in the sample (e.g., Eretmocerus sp.). Finally, deep sequencing data were used to describe the microtranscriptome of OSW: 56 canonical and at least four high-confidence novel microRNAs (miRNAs) were identified. The overall miRNA abundance in OSW was in agreement with previous works on Bemisia tabaci, and bantam-3p, miR-276a-3p, miR-317-3p, miR-750-3p, and mir-8-3p were the most represented miRNAs.}, }
@article {pmid32128956, year = {2020}, author = {Li, Y and Liu, X and Wang, N and Zhang, Y and Hoffmann, AA and Guo, H}, title = {Background-dependent Wolbachia-mediated insecticide resistance in Laodelphax striatellus.}, journal = {Environmental microbiology}, volume = {22}, number = {7}, pages = {2653-2663}, doi = {10.1111/1462-2920.14974}, pmid = {32128956}, issn = {1462-2920}, support = {31672027//the National Natural Science Foundation of China/International ; 31972265//the National Natural Science Foundation of China/International ; //a Fellowship from the National Health and Medical Research Council/International ; cx(16)1001//the Independent Innovation Fund of Agricultural Science and Technology in Jiangsu province, China/International ; }, mesh = {Animals ; China ; Hemiptera/*drug effects/microbiology ; Insecticide Resistance/*physiology ; Insecticides/*pharmacology ; Thiadiazines/*pharmacology ; Wolbachia/*metabolism ; }, abstract = {Although facultative endosymbionts are now known to protect insect hosts against pathogens and parasitoids, the effects of endosymbionts on insecticide resistance are still unclear. Here we show that Wolbachia are associated with increased resistance to the commonly used insecticide, buprofezin, in the small brown planthopper (Laodelphax striatellus) in some genetic backgrounds while having no effect in other backgrounds. In three Wolbachia-infected lines from experimental buprofezin-resistant strains and one line from a buprofezin-susceptible line established from Chuxiong, Yunnan province, China, susceptibility to buprofezin increased after removal of Wolbachia. An increase in susceptibility was also evident in a Wolbachia-infected line established from a field population in Rugao, Jiangsu province. However, no increase was evident in two field populations from Nanjing and Fengxian, Jiangsu province, China. When Wolbachia was introgressed into different genetic backgrounds, followed by Wolbachia removal, the data pointed to Wolbachia effects that depend on the nuclear background as well as on the Wolbachia strain. However, there was no relationship between Wolbachia density and the component of buprofezin resistance associated with the symbiont. The results suggest that Wolbachia effects associated with chemical resistance are complex and unpredictable, but also that they can be substantial.}, }
@article {pmid32126342, year = {2020}, author = {Turner, JD and Marriott, AE and Hong, D and O' Neill, P and Ward, SA and Taylor, MJ}, title = {Novel anti-Wolbachia drugs, a new approach in the treatment and prevention of veterinary filariasis?.}, journal = {Veterinary parasitology}, volume = {279}, number = {}, pages = {109057}, doi = {10.1016/j.vetpar.2020.109057}, pmid = {32126342}, issn = {1873-2550}, support = {MC_PC_17167/MRC_/Medical Research Council/United Kingdom ; MC_PC_18055/MRC_/Medical Research Council/United Kingdom ; NC/S001131/1/NC3RS_/National Centre for the Replacement, Refinement and Reduction of Animals in Research/United Kingdom ; }, mesh = {Animals ; *Anti-Bacterial Agents ; Dirofilaria immitis/*drug effects ; Dirofilaria repens/*drug effects ; Dirofilariasis/*prevention &amp; control ; Doxycycline/*pharmacology ; Filaricides/*pharmacology ; Wolbachia ; }, abstract = {Filarial nematodes are tissue-dwelling parasitic worms that can cause a range of disfiguring pathologies in humans and potentially lethal infections of companion animals. The bacterial endosymbiont, Wolbachia, is present within most human and veterinary filarial pathogens, including the causative agent of heartworm disease, Dirofilaria immitis. Doxycycline-mediated drug targeting of Wolbachia leads to sterility, clearance of microfilariae and gradual death of adult filariae. This mode of action is attractive in the treatment of filariasis because it avoids severe host inflammatory adverse reactions invoked by rapid-killing anthelmintic agents. However, doxycycline needs to be taken for four weeks to exert curative activity. In this review, we discuss the evidence that Wolbachia drug targeting is efficacious in blocking filarial larval development as well as in the treatment of chronic filarial disease. We present the current portfolio of next-generation anti-Wolbachia candidates discovered through phenotypic screening of chemical libraries and validated in a range of in vitro and in vivo filarial infection models. Several novel chemotypes have been identified with selected narrow-spectrum anti-Wolbachia specificity and superior time-to-kill kinetics compared with doxycycline. We discuss the opportunities of developing these novel anti-Wolbachia agents as either cures, adjunct therapies or new preventatives for the treatment of veterinary filariasis.}, }
@article {pmid32125545, year = {2020}, author = {Hinkelman, J and Vršanská, L}, title = {A Myanmar amber cockroach with protruding feces contains pollen and a rich microcenosis.}, journal = {Die Naturwissenschaften}, volume = {107}, number = {2}, pages = {13}, pmid = {32125545}, issn = {1432-1904}, mesh = {*Amber ; Animals ; Cockroaches/*microbiology/*parasitology ; *Feces/cytology/microbiology ; *Fossils ; Myanmar ; *Pollen ; }, abstract = {Early endosymbiotic interactions are recorded only from a Cretaceous termite and a cockroach. Mesoblatta maxi Hinkelman, gen. et sp. nov. is the second representative of the dominant, cosmopolitan Mesozoic family Mesoblattinidae known from Cenomanian northern Myanmar amber, and the fourteenth from both amber and sedimentary rocks. Unique characters are rare (n = 19), symplesiomorphies are frequent (n = 140), and foremost is a standard maxillary palp, an irregular area between forewing veins radius and media, central ocellus, and multisegmented styli, suggesting an ancestral position with respect to Blattidae. Autapomorphies of this otherwise conservative taxon are only its large size and a short probasitarsus. Two nymphs with fecal pellets protruding from their body, Blattocoprolites mesoblattamaxi Hinkelman, ichogen. et ichnosp. nov., represent the first cockroaches with formalized coprolites (along with Blattocoprolites blattulidae Hinkelman, ichnosp. nov. established herein from Lebanese amber) and provide evidence of burial defecation. Subhomogenic consistency of coprolites with mucous components, "pseudoinclusions," leaf, trichia, wood debris, cycad pollen, endosymbiotic protists, and epibiotic bacteria directly document pollen transfer through the digestive tract and the earliest coevolution with protists and bacteria. Other post-burial fecal bacteria at the surface are documented for the first time in the Mesozoic, directly indicating structured dung processing. Reference samples (as well as almost all Myanmar amber samples) contain numerous "pseudoinclusions," probably representing damaged or dead cysts of Chlamydomonas hanublikanus Vršanská et Hinkelman, sp. nov. established on the basis of its reproductive stages (with an origin within the resin inside the tree). These are documented together with green algae, including Spirogyra Nees, 1820; flagellates; and flagellate amoebae, promoting massive future microbiota studies.}, }
@article {pmid32117618, year = {2020}, author = {Martins, C and Moreau, CS}, title = {Influence of host phylogeny, geographical location and seed harvesting diet on the bacterial community of globally distributed Pheidole ants.}, journal = {PeerJ}, volume = {8}, number = {}, pages = {e8492}, pmid = {32117618}, issn = {2167-8359}, abstract = {The presence of symbiotic relationships between organisms is a common phenomenon found across the tree of life. In particular, the association of bacterial symbionts with ants is an active area of study. This close relationship between ants and microbes can significantly impact host biology and is also considered one of the driving forces in ant evolution and diversification. Diet flexibility of ants may explain the evolutionary success of the group, which may be achieved by the presence of endosymbionts that aid in nutrition acquisition from a variety of food sources. With more than 1,140 species, ants from the genus Pheidole have a worldwide distribution and an important role in harvesting seeds; this behavior is believed to be a possible key innovation leading to the diversification of this group. This is the first study to investigate the bacterial community associated with Pheidole using next generation sequencing (NGS) to explore the influences of host phylogeny, geographic location and food preference in shaping the microbial community. In addition, we explore if there are any microbiota signatures related to granivory. We identified Proteobacteria and Firmicutes as the major phyla associated with these ants. The core microbiome in Pheidole (those found in >50% of all samples) was composed of 14 ASVs and the most prevalent are family Burkholderiaceae and the genera Acinetobacter, Streptococcus, Staphylococcus, Cloacibacterium and Ralstonia. We found that geographical location and food resource may influence the bacterial community of Pheidole ants. These results demonstrate that Pheidole has a relatively stable microbiota across species, which suggests the bacterial community may serve a generalized function in this group.}, }
@article {pmid32110116, year = {2020}, author = {Fazeli, B and Mirhosseini, A and Hashemi, Z and Taheri, H}, title = {Detection of Rickettsia Endosymbiont Bemisia Tabaci in the Amputated Limbs of Three Buerger's Disease Patients.}, journal = {International medical case reports journal}, volume = {13}, number = {}, pages = {33-40}, pmid = {32110116}, issn = {1179-142X}, abstract = {Until recently, the aetiology of Buerger's disease (BD) has been unknown. Although there is a close relationship between BD and smoking, it cannot explain the low prevalence of BD among smokers or the disease's geographical distribution. Infectious pathogens, such as Rickettsial infection, have also been suggested as the trigger of BD development, but this theory has neither been proven nor ruled out. The aim of this study was to evaluate the footprint of Rickettsial infection in tissue specimens obtained from amputees with Buerger's disease. Forty-nine tissue biopsies were obtained from three below-the-knee amputees who also had a diagnosis of BD according to Olin's criteria (between 14-21 biopsies for each patient). After extraction of DNA from the tissue samples, the existence of 16srRNA was evaluated using a PCR test. The sequence of PCR products was evaluated using Geneious 11.1.2 software and NCBI blast. The 16srRNA was found in 3 to 7 samples from each patient. The sequence of the PCR products had a 98% homology with Rickettsia Tabaci. The sequences of the three patients were aligned, and no difference was found in the sequence of 16srRNA amongst the patients. Rickettsia Tabaci is a pathogen that infects tobacco leaves. Thus, BD might be an infectious disease for which smoking could be the route of pathogen entry into the bloodstreams of the sufferers. However, further studies are highly recommended to confirm this hypothesis.}, }
@article {pmid32108180, year = {2020}, author = {Martin, SH and Singh, KS and Gordon, IJ and Omufwoko, KS and Collins, S and Warren, IA and Munby, H and Brattström, O and Traut, W and Martins, DJ and Smith, DAS and Jiggins, CD and Bass, C and Ffrench-Constant, RH}, title = {Whole-chromosome hitchhiking driven by a male-killing endosymbiont.}, journal = {PLoS biology}, volume = {18}, number = {2}, pages = {e3000610}, pmid = {32108180}, issn = {1545-7885}, support = {339873/ERC_/European Research Council/International ; }, mesh = {Animals ; Butterflies/*genetics/microbiology ; Chromosomes, Insect/*genetics ; Evolution, Molecular ; Female ; Genetic Linkage ; Genome/genetics ; Haplotypes ; Male ; Phenotype ; Sex Chromosomes/*genetics ; Spiroplasma/genetics ; }, abstract = {Neo-sex chromosomes are found in many taxa, but the forces driving their emergence and spread are poorly understood. The female-specific neo-W chromosome of the African monarch (or queen) butterfly Danaus chrysippus presents an intriguing case study because it is restricted to a single 'contact zone' population, involves a putative colour patterning supergene, and co-occurs with infection by the male-killing endosymbiont Spiroplasma. We investigated the origin and evolution of this system using whole genome sequencing. We first identify the 'BC supergene', a broad region of suppressed recombination across nearly half a chromosome, which links two colour patterning loci. Association analysis suggests that the genes yellow and arrow in this region control the forewing colour pattern differences between D. chrysippus subspecies. We then show that the same chromosome has recently formed a neo-W that has spread through the contact zone within approximately 2,200 years. We also assembled the genome of the male-killing Spiroplasma, and find that it shows perfect genealogical congruence with the neo-W, suggesting that the neo-W has hitchhiked to high frequency as the male-killer has spread through the population. The complete absence of female crossing-over in the Lepidoptera causes whole-chromosome hitchhiking of a single neo-W haplotype, carrying a single allele of the BC supergene and dragging multiple non-synonymous mutations to high frequency. This has created a population of infected females that all carry the same recessive colour patterning allele, making the phenotypes of each successive generation highly dependent on uninfected male immigrants. Our findings show how hitchhiking can occur between the physically unlinked genomes of host and endosymbiont, with dramatic consequences.}, }
@article {pmid32098825, year = {2020}, author = {Teymournejad, O and Lin, M and Bekebrede, H and Kamr, A and Toribio, RE and Arroyo, LG and Baird, JD and Rikihisa, Y}, title = {Isolation and Molecular Analysis of a Novel Neorickettsia Species That Causes Potomac Horse Fever.}, journal = {mBio}, volume = {11}, number = {1}, pages = {}, pmid = {32098825}, issn = {2150-7511}, mesh = {Anaplasmataceae Infections/diagnosis/*microbiology ; Animals ; Antigens, Bacterial/genetics ; Canada ; DNA, Bacterial/analysis ; Disease Models, Animal ; Female ; Horse Diseases/diagnosis/*microbiology ; Horses ; Male ; Neorickettsia/*classification/*genetics/*isolation &amp; purification/pathogenicity ; Neorickettsia risticii/genetics/isolation &amp; purification ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis ; Trematoda/microbiology ; Whole Genome Sequencing ; }, abstract = {Potomac horse fever (PHF), a severe and frequently fatal febrile diarrheal disease, has been known to be caused only by Neorickettsia risticii, an endosymbiont of digenean trematodes. Here, we report the cell culture isolation of a new Neorickettsia species found in two locations in eastern Ontario, Canada, in 2016 and 2017 (in addition to 10 variable strains of N. risticii) from N. risticii PCR-negative horses with clinical signs of PHF. Gene sequences of 16S rRNA and the major surface antigen P51 of this new Neorickettsia species were distinct from those of all previously characterized N. risticii strains and Neorickettsia species, except for those from an uncharacterized Neorickettsia species culture isolate from a horse with PHF in northern Ohio in 1991. The new Neorickettsia species nonetheless had the characteristic intramolecular repeats within strain-specific antigen 3 (Ssa3), which were found in all sequenced Ssa3s of N. risticii strains. Experimental inoculation of two naive ponies with the new Neorickettsia species produced severe and subclinical PHF, respectively, and the bacteria were reisolated from both of them, fulfilling Koch's postulates. Serological assay titers against the new Neorickettsia species were higher than those against N. risticii Whole-genome sequence analysis of the new Neorickettsia species revealed unique features of this bacterium compared with N. risticii We propose to classify this new bacterium as Neorickettsia finleia sp. nov. This finding will improve the laboratory diagnosis of and vaccine for PHF, environmental risk assessment of PHF, and understanding of PHF pathogenesis and Neorickettsia biology in general.IMPORTANCE Despite the detection of Neorickettsia species DNA sequences in various trematode species and their hosts, only three Neorickettsia species have been cell culture isolated and whole-genome sequenced and are known to infect mammals and/or cause disease. The molecular mechanisms that enable the obligatory intracellular bacterium Neorickettsia to colonize trematodes and to horizontally transmit from trematodes to mammals, as well as the virulence factors associated with specific mammalian hosts, are unknown. Potomac horse fever (PHF) is a severe and acute systemic infectious disease of horses, with clinical signs that include diarrhea. Neorickettsia risticii is the only known bacterial species that causes PHF. Ingestion of insects harboring N. risticii-infected trematodes by horses leads to PHF. Our discovery of a new Neorickettsia species that causes PHF and whole-genome sequence analysis of this bacterium will improve laboratory diagnosis and vaccine development for PHF and will contribute to our understanding of Neorickettsia ecology, pathogenesis, and biology.}, }
@article {pmid32096554, year = {2020}, author = {Preedy, KF and Chaplain, MAJ and Leybourne, DJ and Marion, G and Karley, AJ}, title = {Learning-induced switching costs in a parasitoid can maintain diversity of host aphid phenotypes although biocontrol is destabilized under abiotic stress.}, journal = {The Journal of animal ecology}, volume = {89}, number = {5}, pages = {1216-1229}, doi = {10.1111/1365-2656.13189}, pmid = {32096554}, issn = {1365-2656}, mesh = {Animals ; *Aphids ; Enterobacteriaceae ; Phenotype ; Stress, Physiological ; Symbiosis ; *Wasps ; }, abstract = {Aphid populations frequently include phenotypes that are resistant to parasitism by hymenopterous parasitoid wasps, which is often attributed to the presence of 'protective' facultative endosymbionts residing in aphid tissues, particularly Hamiltonella defensa. In field conditions, under parasitoid pressure, the observed coexistence of aphids with and without protective symbionts cannot be explained by their difference in fitness alone. Using the cereal aphid Rhopalosiphum padi as a model, we propose an alternative mechanism whereby parasitoids are more efficient at finding common phenotypes of aphid and experience a fitness cost when switching to the less common phenotype. We construct a model based on delay differential equations and parameterize and validate the model with values within the ranges obtained from experimental studies. We then use it to explore the possible effects on system dynamics under conditions of environmental stress, using our existing data on the effects of drought stress in crops as an example. We show the 'switching penalty' incurred by parasitoids leads to stable coexistence of aphids with and without H. defensa and provides a potential mechanism for maintaining phenotypic diversity among host organisms. We show that drought-induced reduction in aphid development time has little impact. However, greater reduction in fecundity on droughted plants of symbiont-protected aphids can cause insect population cycles when the system would be stable in the absence of drought stress. The stabilizing effect of the increased efficiency in dealing with more commonly encountered host phenotypes is applicable to a broad range of consumer-resource systems and could explain stable coexistence in competitive environments. The loss of stable coexistence when drought has different effects on the competing aphid phenotypes highlights the importance of scenario testing when considering biocontrol for pest management.}, }
@article {pmid32095829, year = {2020}, author = {Zou, M and Mu, Y and Chai, X and Ouyang, M and Yu, LJ and Zhang, L and Meurer, J and Chi, W}, title = {The critical function of the plastid rRNA methyltransferase, CMAL, in ribosome biogenesis and plant development.}, journal = {Nucleic acids research}, volume = {48}, number = {6}, pages = {3195-3210}, pmid = {32095829}, issn = {1362-4962}, mesh = {Arabidopsis/genetics/growth &amp; development ; Chloroplasts/genetics ; Gene Expression Regulation, Plant/genetics ; Methylation ; Methyltransferases/*genetics ; Plant Development/*genetics ; Plant Leaves/genetics/growth &amp; development ; Plastids/genetics ; RNA, Messenger/genetics ; RNA, Plant/genetics ; RNA, Ribosomal, 16S/*genetics ; Ribosomes/*genetics ; }, abstract = {Methylation of nucleotides in ribosomal RNAs (rRNAs) is a ubiquitous feature that occurs in all living organisms. The formation of methylated nucleotides is performed by a variety of RNA-methyltransferases. Chloroplasts of plant cells result from an endosymbiotic event and possess their own genome and ribosomes. However, enzymes responsible for rRNA methylation and the function of modified nucleotides in chloroplasts remain to be determined. Here, we identified an rRNA methyltransferase, CMAL (Chloroplast MraW-Like), in the Arabidopsis chloroplast and investigated its function. CMAL is the Arabidopsis ortholog of bacterial MraW/ RsmH proteins and accounts to the N4-methylation of C1352 in chloroplast 16S rRNA, indicating that CMAL orthologs and this methyl-modification nucleotide is conserved between bacteria and the endosymbiont-derived eukaryotic organelle. The knockout of CMAL in Arabidopsis impairs the chloroplast ribosome accumulation and accordingly reduced the efficiency of mRNA translation. Interestingly, the loss of CMAL leads not only to defects in chloroplast function, but also to abnormal leaf and root development and overall plant morphology. Further investigation showed that CMAL is involved in the plant development probably by modulating auxin derived signaling pathways. This study uncovered the important role of 16S rRNA methylation mediated by CMAL in chloroplast ribosome biogenesis and plant development.}, }
@article {pmid32094181, year = {2020}, author = {Sarai, C and Tanifuji, G and Nakayama, T and Kamikawa, R and Takahashi, K and Yazaki, E and Matsuo, E and Miyashita, H and Ishida, KI and Iwataki, M and Inagaki, Y}, title = {Dinoflagellates with relic endosymbiont nuclei as models for elucidating organellogenesis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {117}, number = {10}, pages = {5364-5375}, pmid = {32094181}, issn = {1091-6490}, mesh = {Cell Nucleus/genetics/physiology ; Cercozoa/classification/genetics/*ultrastructure ; Chlorophyta/classification/physiology/ultrastructure ; Cryptophyta/classification/genetics/*ultrastructure ; Dinoflagellida/classification/genetics/*ultrastructure ; *Evolution, Molecular ; *Genome, Plastid ; Models, Biological ; Phylogeny ; Plastids/genetics/*physiology ; *Symbiosis ; }, abstract = {Nucleomorphs are relic endosymbiont nuclei so far found only in two algal groups, cryptophytes and chlorarachniophytes, which have been studied to model the evolutionary process of integrating an endosymbiont alga into a host-governed plastid (organellogenesis). However, past studies suggest that DNA transfer from the endosymbiont to host nuclei had already ceased in both cryptophytes and chlorarachniophytes, implying that the organellogenesis at the genetic level has been completed in the two systems. Moreover, we have yet to pinpoint the closest free-living relative of the endosymbiotic alga engulfed by the ancestral chlorarachniophyte or cryptophyte, making it difficult to infer how organellogenesis altered the endosymbiont genome. To counter the above issues, we need novel nucleomorph-bearing algae, in which endosymbiont-to-host DNA transfer is on-going and for which endosymbiont/plastid origins can be inferred at a fine taxonomic scale. Here, we report two previously undescribed dinoflagellates, strains MGD and TGD, with green algal endosymbionts enclosing plastids as well as relic nuclei (nucleomorphs). We provide evidence for the presence of DNA in the two nucleomorphs and the transfer of endosymbiont genes to the host (dinoflagellate) genomes. Furthermore, DNA transfer between the host and endosymbiont nuclei was found to be in progress in both the MGD and TGD systems. Phylogenetic analyses successfully resolved the origins of the endosymbionts at the genus level. With the combined evidence, we conclude that the host-endosymbiont integration in MGD/TGD is less advanced than that in cryptophytes/chrorarachniophytes, and propose the two dinoflagellates as models for elucidating organellogenesis.}, }
@article {pmid32092972, year = {2020}, author = {Kaczmarczyk-Ziemba, A and Zagaja, M and Wagner, GK and Pietrykowska-Tudruj, E and Staniec, B}, title = {First Insight into Microbiome Profiles of Myrmecophilous Beetles and Their Host, Red Wood Ant Formica polyctena (Hymenoptera: Formicidae)-A Case Study.}, journal = {Insects}, volume = {11}, number = {2}, pages = {}, pmid = {32092972}, issn = {2075-4450}, abstract = {Formica polyctena belongs to the red wood ant species group. Its nests provide a stable, food rich, and temperature and humidity controlled environment, utilized by a wide range of species, called myrmecophiles. Here, we used the high-throughput sequencing of the 16S rRNA gene on the Illumina platform for identification of the microbiome profiles of six selected myrmecophilous beetles (Dendrophilus pygmaeus, Leptacinus formicetorum, Monotoma angusticollis, Myrmechixenus subterraneus, Ptenidium formicetorum and Thiasophila angulata) and their host F. polyctena. Analyzed bacterial communities consisted of a total of 23 phyla, among which Proteobacteria, Actinobacteria, and Firmicutes were the most abundant. Two known endosymbionts-Wolbachia and Rickettsia-were found in the analyzed microbiome profiles and Wolbachia was dominant in bacterial communities associated with F. polyctena, M. subterraneus, L. formicetorum and P. formicetorum (>90% of reads). In turn, M. angusticollis was co-infected with both Wolbachia and Rickettsia, while in the microbiome of T. angulata, the dominance of Rickettsia has been observed. The relationships among the microbiome profiles were complex, and no relative abundance pattern common to all myrmecophilous beetles tested was observed. However, some subtle, species-specific patterns have been observed for bacterial communities associated with D. pygmaeus, M. angusticollis, and T. angulata.}, }
@article {pmid32087072, year = {2019}, author = {Elbir, H and Almathen, F and Alhumam, NA}, title = {A glimpse of the bacteriome of Hyalomma dromedarii ticks infesting camels reveals human Helicobacter pylori pathogen.}, journal = {Journal of infection in developing countries}, volume = {13}, number = {11}, pages = {1001-1012}, doi = {10.3855/jidc.11604}, pmid = {32087072}, issn = {1972-2680}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Camelus/*parasitology ; Cross-Sectional Studies ; Helicobacter pylori/genetics/isolation &amp; purification/pathogenicity ; Humans ; Ixodidae/*microbiology/physiology ; Phylogeny ; RNA, Ribosomal, 16S ; Saudi Arabia ; }, abstract = {INTRODUCTION: The tick Hyalomma dromedarii is predominant in camels of Saudi Arabia and harbor multiple pathogens causing disease in humans and animals. Knowing the bacterial community of ticks is crucial for surveillance of known and newly emerging pathogens. Yet, the bacteriome of H. dromedarii remain unexplored to date.<br><br>METHODOLOGY: In a cross-sectional survey, we used V3-V4 region of 16S rRNA to characterize the bacteriome of 62 whole H. dromedarii tick samples collected from camels found in Hofuf city in Saudi Arabia.<br><br>RESULTS: Sequencing results yielded 217 species incorporated into 114 genera, which in turn belong to the dominant phylum Proteobacteria (98%) followed by Firmicutes (1.38%), Actinobacteria (0.36%), Bacteroidetes (0.17%), meanwhile the phyla Cyanobacteria, Verrucomicrobia and unclassified bacteria were rarely detected. Francisella endosymbiont dominated the bacteriome of H. dromedarii ticks with average abundance of 94.37% and together with Salincoccus sp. accounted for 94.51% of the average sequences. The remaining bacteriome consisted of low abundance of potential pathogens and environmental bacteria. Of these pathogens, we found Helicobacter pylori in the tick H. dromedarii for the first time. Notably, Anaplasma, Ehrlichia and Rickettsia pathogens known to be found in H. dromedarii ticks were not detected.<br><br>CONCLUSION: This first preliminary study advances our knowledge about the bacterial community of H. dromedarii ticks and provides a basis for pathogen surveillance and studying the influences of symbionts on vector competence. Presence of pathogens in ticks, raise concerns about potential transmission of these agents to humans or animals.}, }
@article {pmid32080867, year = {2020}, author = {Speijer, D}, title = {Debating Eukaryogenesis-Part 1: Does Eukaryogenesis Presuppose Symbiosis Before Uptake?.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {42}, number = {4}, pages = {e1900157}, doi = {10.1002/bies.201900157}, pmid = {32080867}, issn = {1521-1878}, mesh = {Adaptation, Physiological ; Archaea/*metabolism ; Bacteria/*metabolism ; Biological Evolution ; Eukaryota/*metabolism ; Eukaryotic Cells/*metabolism ; Mitochondria/metabolism ; Phagocytosis/physiology ; Phylogeny ; Reactive Oxygen Species/metabolism ; Signal Transduction/physiology ; Symbiosis/*physiology ; }, abstract = {Eukaryotic origins are heavily debated. The author as well as others have proposed that they are inextricably linked with the arrival of a pre-mitochondrion of alphaproteobacterial-like ancestry, in a so-called symbiogenic scenario. The ensuing mutual adaptation of archaeal host and endosymbiont seems to have been a defining influence during the processes leading to the last eukaryotic common ancestor. An unresolved question in this scenario deals with the means by which the bacterium ends up inside. Older hypotheses revolve around the application of known antagonistic interactions, the bacterium being prey or parasite. Here, in reviewing the field, the author argues that such models share flaws, hence making them less likely, and that a "pre-symbiotic stage" would have eased ongoing metabolic integration. Based on this the author will speculate about the nature of the (endo) symbiosis that started eukaryotic evolution-in the context of bacterial entry being a relatively "early" event-and stress the differences between this uptake and subsequent ones. He will also briefly discuss how the mutual adaptation following the merger progressed and how many eukaryotic hallmarks can be understood in light of coadaptation. Also see the video abstract here https://youtu.be/ekqtNleVJpU.}, }
@article {pmid32077495, year = {2020}, author = {Selim, KA and Ermilova, E and Forchhammer, K}, title = {From cyanobacteria to Archaeplastida: new evolutionary insights into PII signalling in the plant kingdom.}, journal = {The New phytologist}, volume = {227}, number = {3}, pages = {722-731}, doi = {10.1111/nph.16492}, pmid = {32077495}, issn = {1469-8137}, mesh = {Bacterial Proteins/metabolism ; *Cyanobacteria/genetics/metabolism ; Ketoglutaric Acids ; PII Nitrogen Regulatory Proteins/genetics/metabolism ; *Rhodophyta ; Signal Transduction ; }, abstract = {The PII superfamily consists of signal transduction proteins found in all domains of life. Canonical PII proteins sense the cellular energy state through the competitive binding of ATP and ADP, and carbon/nitrogen balance through 2-oxoglutarate binding. The ancestor of Archaeplastida inherited its PII signal transduction protein from an ancestral cyanobacterial endosymbiont. Over the course of evolution, plant PII proteins acquired a glutamine-sensing C-terminal extension, subsequently present in all Chloroplastida PII proteins. The PII proteins of various algal strains (red, green and nonphotosynthetic algae) have been systematically investigated with respect to their sensory and regulatory properties. Comparisons of the PII proteins from different phyla of oxygenic phototrophs (cyanobacteria, red algae, Chlorophyta and higher plants) have yielded insights into their evolutionary conservation vs adaptive properties. The highly conserved role of the controlling enzyme of arginine biosynthesis, N-acetyl-l-glutamate kinase (NAGK), as a main PII-interactor has been demonstrated across oxygenic phototrophs of cyanobacteria and Archaeplastida. In addition, the PII signalling system of red algae has been identified as an evolutionary intermediate between that of Cyanobacteria and Chloroplastida. In this review, we consider recent advances in understanding metabolic signalling by PII proteins of the plant kingdom.}, }
@article {pmid32076535, year = {2020}, author = {Ross, PA and Callahan, AG and Yang, Q and Jasper, M and Arif, MAK and Afizah, AN and Nazni, WA and Hoffmann, AA}, title = {An elusive endosymbiont: Does Wolbachia occur naturally in Aedes aegypti?.}, journal = {Ecology and evolution}, volume = {10}, number = {3}, pages = {1581-1591}, pmid = {32076535}, issn = {2045-7758}, abstract = {Wolbachia are maternally inherited endosymbiotic bacteria found within many insect species. Aedes mosquitoes experimentally infected with Wolbachia are being released into the field for Aedes-borne disease control. These Wolbachia infections induce cytoplasmic incompatibility which is used to suppress populations through incompatible matings or replace populations through the reproductive advantage provided by this mechanism. However, the presence of naturally occurring Wolbachia in target populations could interfere with both population replacement and suppression programs depending on the compatibility patterns between strains. Aedes aegypti were thought to not harbor Wolbachia naturally but several recent studies have detected Wolbachia in natural populations of this mosquito. We therefore review the evidence for natural Wolbachia infections in A. aegypti to date and discuss limitations of these studies. We draw on research from other mosquito species to outline the potential implications of natural Wolbachia infections in A. aegypti for disease control. To validate previous reports, we obtained a laboratory population of A. aegypti from New Mexico, USA, that harbors a natural Wolbachia infection, and we conducted field surveys in Kuala Lumpur, Malaysia, where a natural Wolbachia infection has also been reported. However, we were unable to detect Wolbachia in both the laboratory and field populations. Because the presence of naturally occurring Wolbachia in A. aegypti could have profound implications for Wolbachia-based disease control programs, it is important to continue to accurately assess the Wolbachia status of target Aedes populations.}, }
@article {pmid32072355, year = {2020}, author = {Erban, T and Klimov, P and Molva, V and Hubert, J}, title = {Whole genomic sequencing and sex-dependent abundance estimation of Cardinium sp., a common and hyperabundant bacterial endosymbiont of the American house dust mite, Dermatophagoides farinae.}, journal = {Experimental &amp; applied acarology}, volume = {80}, number = {3}, pages = {363-380}, pmid = {32072355}, issn = {1572-9702}, mesh = {Animals ; Bacteroidetes/*isolation &amp; purification ; China ; Dermatophagoides farinae/*microbiology ; Dermatophagoides pteronyssinus/microbiology ; Europe ; Female ; *Genome, Bacterial ; Male ; Microbiota ; Symbiosis ; United States ; Whole Genome Sequencing ; }, abstract = {The two common species of house dust mites (HDMs), Dermatophagoides farinae and D. pteronyssinus, are major sources of allergens in human dwellings worldwide. Many allergens from HDMs have been described, but their extracts vary in immunogens. Mite strains may differ in their microbiomes, which affect mite allergen expression and contents of bacterial endotoxins. Some bacteria, such as the intracellular symbiont Cardinium, can affect both the sex ratio and biochemical pathways of mites, resulting in abundance variations of mite allergens/immunogens. Here, we investigated the bacterial microbiomes of D. farinae and D. pteronyssinus males and females using barcode 16S rDNA sequencing, qPCR, and genomic data analysis. We found a single species of Cardinium associated with D. farinae strains from the USA, China and Europe. Cardinium had high abundance relative to other bacterial taxa and represented 99% of all bacterial DNA reads from female mites from the USA. Cardinium was also abundant with respect to the number of host cells-we estimated 10.4-11.8 cells of Cardinium per single female mite cell. In a European D. farinae strain, Cardinium was more prevalent in females than in males (representing 92 and 67% of all bacterial taxa in females and males, respectively). In contrast, D. pteronyssinus lacked any Cardinium species, and the microbiomes of male and female mites were similar. We produced a Cardinium genome assembly (1.48 Mb; GenBank: PRJNA555788, GCA_007559345.1) associated with D. farinae. The ascertained ubiquity and abundance of Cardinium strongly suggest that this intracellular bacterium plays an important biological role in D. farinae.}, }
@article {pmid32068830, year = {2020}, author = {Husnik, F and Hypsa, V and Darby, A}, title = {Insect-Symbiont Gene Expression in the Midgut Bacteriocytes of a Blood-Sucking Parasite.}, journal = {Genome biology and evolution}, volume = {12}, number = {4}, pages = {429-442}, pmid = {32068830}, issn = {1759-6653}, support = {BB/J017698/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Biological Evolution ; DNA, Bacterial/analysis/genetics ; Digestive System/*microbiology ; Diptera/*genetics/*microbiology ; Disease Vectors ; *Gastrointestinal Microbiome ; *Genes, Insect ; Host-Pathogen Interactions ; Phylogeny ; Sheep/*parasitology ; Symbiosis ; Transcriptome ; }, abstract = {Animals interact with a diverse array of both beneficial and detrimental microorganisms. In insects, these symbioses in many cases allow feeding on nutritionally unbalanced diets. It is, however, still not clear how are obligate symbioses maintained at the cellular level for up to several hundred million years. Exact mechanisms driving host-symbiont interactions are only understood for a handful of model species and data on blood-feeding hosts with intracellular bacteria are particularly scarce. Here, we analyzed interactions between an obligately blood-sucking parasite of sheep, the louse fly Melophagus ovinus, and its obligate endosymbiont, Arsenophonus melophagi. We assembled a reference transcriptome for the insect host and used dual RNA-Seq with five biological replicates to compare expression in the midgut cells specialized for housing symbiotic bacteria (bacteriocytes) to the rest of the gut (foregut-hindgut). We found strong evidence for the importance of zinc in the system likely caused by symbionts using zinc-dependent proteases when acquiring amino acids, and for different immunity mechanisms controlling the symbionts than in closely related tsetse flies. Our results show that cellular and nutritional interactions between this blood-sucking insect and its symbionts are less intimate than what was previously found in most plant-sap sucking insects. This finding is likely interconnected to several features observed in symbionts in blood-sucking arthropods, particularly their midgut intracellular localization, intracytoplasmic presence, less severe genome reduction, and relatively recent associations caused by frequent evolutionary losses and replacements.}, }
@article {pmid32067949, year = {2020}, author = {Eisen, L}, title = {Vector competence studies with hard ticks and Borrelia burgdorferi sensu lato spirochetes: A review.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {3}, pages = {101359}, pmid = {32067949}, issn = {1877-9603}, support = {CC999999/ImCDC/Intramural CDC HHS/United States ; }, mesh = {Animals ; Arachnid Vectors/*microbiology ; Borrelia burgdorferi Group/*physiology ; Ixodidae/*microbiology ; Lyme Disease/*transmission ; Species Specificity ; }, abstract = {Use of emerging technology allowing for identification of genetic material from pathogens and endosymbionts in ticks collected from humans, domestic animals, wildlife, or the environment has resulted in an avalanche of new data on tick-microorganism associations. This rapidly growing stream of new information is a tremendous resource but also presents challenges, including how detection of pathogen genetic material in ticks should best be interpreted. There is a tendency in the more recent published literature to incorrectly use the term "vector" based on detection of pathogen genetic material from tick species not experimentally confirmed to serve as vectors of the pathogen in question. To serve as a vector of a horizontally maintained pathogen, such as a Borrelia burgdorferi sensu lato (s.l.) Lyme borreliosis spirochete, the tick species in question must be capable of acquiring the pathogen while feeding in the larval or nymphal stage on an infectious host, maintaining it transstadially through the molt, and then transmitting the pathogen to a naïve host while feeding in the subsequent nymphal or adult stage. This review examines the experimental evidence for and against species of hard (ixodid) ticks from different genera to serve as vectors of B. burgdorferi s.l. spirochetes. Of the 18 Ixodes species ticks evaluated to date, 13 were experimentally confirmed as vectors of B. burgdorferi s.l. spirochetes. These studies focused primarily on the three major Lyme borreliosis agents: Borrelia burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii. In striking contrast, none of 8 tick species from other genera (1 Amblyomma species, 5 Dermacentor species, and 2 Haemaphysalis species) evaluated to date were unequivocally experimentally confirmed as vectors of B. burgdorferi s.l. spirochetes. The strength of the evidence for or against each tick species to serve as a vector of B. burgdorferi s.l. spirochetes is discussed together with key knowledge gaps and research challenges.}, }
@article {pmid32053248, year = {2020}, author = {Zhao, W and Li, M and Xiong, F and Zhang, D and Wu, S and Zou, H and Li, W and Wang, G}, title = {Identification of Intracellular Bacteria in the Ciliate Balantidium ctenopharyngodoni (Ciliophora, Litostomatea).}, journal = {The Journal of eukaryotic microbiology}, volume = {67}, number = {4}, pages = {417-426}, doi = {10.1111/jeu.12791}, pmid = {32053248}, issn = {1550-7408}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; Balantidium/*growth &amp; development/microbiology ; Carps/*parasitology ; Cytoplasm/microbiology/ultrastructure ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; In Situ Hybridization, Fluorescence ; Microbiological Techniques ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA/*methods ; }, abstract = {The ciliate Balantidium ctenopharyngodoni is the most prominent protist in the guts of grass carp, where it mainly inhabits the creamy luminal contents of the hindgut. Ciliates are generally colonized by microorganisms via phagotrophic feeding. In order to study the intracellular bacteria in this ciliate, we have successfully established it in in vitro culture. Herein, we investigated and compared the bacterial community structures of cultured and freshly collected B. ctenopharyngodoni. The results showed that these two groups exhibited different bacterial communities. The most abundant bacterial family in freshly collected samples was Enterobacteriaceae, while in cultured samples it was Fusobacteriaceae. In addition, a key intracellular bacterium, Cetobacterium somerae, was identified in the cytoplasm of cultured ciliates using fluorescence in situ hybridization (FISH). This study shows that ciliates can retain the intracellular bacteria acquired in the natural habitat for quite a long time, but the bacterial community structure of ciliates eventually changes after a long period of cultivation.}, }
@article {pmid32052099, year = {2020}, author = {Nakabachi, A and Malenovský, I and Gjonov, I and Hirose, Y}, title = {16S rRNA Sequencing Detected Profftella, Liberibacter, Wolbachia, and Diplorickettsia from Relatives of the Asian Citrus Psyllid.}, journal = {Microbial ecology}, volume = {80}, number = {2}, pages = {410-422}, doi = {10.1007/s00248-020-01491-z}, pmid = {32052099}, issn = {1432-184X}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Female ; France ; Hemiptera/*microbiology ; Male ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Symbiosis ; Wolbachia/isolation &amp; purification ; }, abstract = {The Asian citrus psyllid Diaphorina citri (Hemiptera: Psylloidea) is a serious pest of citrus species worldwide because it transmits Candidatus Liberibacter spp. (Alphaproteobacteria: Rhizobiales), the causative agents of the incurable citrus disease, huanglongbing or greening disease. Diaphorina citri possesses a specialized organ called a bacteriome, which harbors vertically transmitted intracellular mutualists, Ca. Carsonella ruddii (Gammaproteobacteria: Oceanospirillales) and Ca. Profftella armatura (Gammaproteobacteria: Betaproteobacteriales). Whereas Carsonella is a typical nutritional symbiont, Profftella is an unprecedented type of toxin-producing defensive symbiont, unusually sharing organelle-like features with nutritional symbionts. Additionally, many D. citri strains are infected with Wolbachia, which manipulate reproduction in various arthropod hosts. In the present study, in an effort to obtain insights into the evolution of symbioses between Diaphorina and bacteria, microbiomes of psyllids closely related to D. citri were investigated. Bacterial populations of Diaphorina cf. continua and Diaphorina lycii were analyzed using Illumina sequencing of 16S rRNA gene amplicons and compared with data obtained from D. citri. The analysis revealed that all three Diaphorina spp. harbor Profftella as well as Carsonella lineages, implying that Profftella is widespread within the genus Diaphorina. Moreover, the analysis identified Ca. Liberibacter europaeus and Diplorickettsia sp. (Gammaproteobacteria: Diplorickettsiales) in D. cf. continua, and a total of four Wolbachia (Alphaproteobacteria: Rickettsiales) lineages in the three psyllid species. These results provide deeper insights into the interactions among insects, bacteria, and plants, which would eventually help to better manage horticulture.}, }
@article {pmid32051527, year = {2020}, author = {Miyazaki, J and Ikuta, T and Watsuji, TO and Abe, M and Yamamoto, M and Nakagawa, S and Takaki, Y and Nakamura, K and Takai, K}, title = {Dual energy metabolism of the Campylobacterota endosymbiont in the chemosynthetic snail Alviniconcha marisindica.}, journal = {The ISME journal}, volume = {14}, number = {5}, pages = {1273-1289}, pmid = {32051527}, issn = {1751-7370}, mesh = {Animals ; Bacteria/genetics ; Campylobacter/*physiology ; Energy Metabolism ; Gills/microbiology ; In Situ Hybridization, Fluorescence ; Indian Ocean ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Snails/*microbiology/physiology ; *Symbiosis ; }, abstract = {Some deep-sea chemosynthetic invertebrates and their symbiotic bacteria can use molecular hydrogen (H2) as their energy source. However, how much the chemosynthetic holobiont (endosymbiont-host association) physiologically depends on H2 oxidation has not yet been determined. Here, we demonstrate that the Campylobacterota endosymbionts of the gastropod Alviniconcha marisindica in the Kairei and Edmond fields (kAlv and eAlv populations, respectively) of the Indian Ocean, utilize H2 in response to their physical and environmental H2 conditions, although the 16S rRNA gene sequence of both the endosymbionts shared 99.6% identity. A thermodynamic calculation using in situ H2 and hydrogen sulfide (H2S) concentrations indicated that chemosynthetic symbiosis could be supported by metabolic energy via H2 oxidation, particularly for the kAlv holobiont. Metabolic activity measurements showed that both the living individuals and the gill tissues consumed H2 and H2S at similar levels. Moreover, a combination of fluorescence in situ hybridization, quantitative transcript analyses, and enzymatic activity measurements showed that the kAlv endosymbiont expressed the genes and enzymes for both H2- and sulfur-oxidations. These results suggest that both H2 and H2S could serve as the primary energy sources for the kAlv holobiont. The eAlv holobiont had the ability to utilize H2, but the gene expression and enzyme activity for hydrogenases were much lower than for sulfur-oxidation enzymes. These results suggest that the energy acquisitions of A. marisindica holobionts are dependent on H2- and sulfur-oxidation in the H2-enriched Kairei field and that the mechanism of dual metabolism is controlled by the in situ H2 concentration.}, }
@article {pmid32048447, year = {2020}, author = {Howe-Kerr, LI and Bachelot, B and Wright, RM and Kenkel, CD and Bay, LK and Correa, AMS}, title = {Symbiont community diversity is more variable in corals that respond poorly to stress.}, journal = {Global change biology}, volume = {}, number = {}, pages = {}, doi = {10.1111/gcb.14999}, pmid = {32048447}, issn = {1365-2486}, abstract = {Coral reefs are declining globally as climate change and local water quality press environmental conditions beyond the physiological tolerances of holobionts-the collective of the host and its microbial symbionts. To assess the relationship between symbiont composition and holobiont stress tolerance, community diversity metrics were quantified for dinoflagellate endosymbionts (Family: Symbiodiniaceae) from eight Acropora millepora genets that thrived under or responded poorly to various stressors. These eight selected genets represent the upper and lower tails of the response distribution of 40 coral genets that were exposed to four stress treatments (and control conditions) in a 10-day experiment. Specifically, four 'best performer' coral genets were analyzed at the end of the experiment because they survived high temperature, high pCO2 , bacterial exposure, or combined stressors, whereas four 'worst performer' genets were characterized because they experienced substantial mortality under these stressors. At the end of the experiment, seven of eight coral genets mainly hosted Cladocopium symbionts, whereas the eighth genet was dominated by both Cladocopium and Durusdinium symbionts. Symbiodiniaceae alpha and beta diversity were higher in worst performing genets than in best performing genets. Symbiont communities in worst performers also differed more after stress exposure relative to their controls (based on normalized proportional differences in beta diversity), than did best performers. A generalized joint attribute model estimated the influence of host genet and treatment on Symbiodiniaceae community composition and identified strong associations among particular symbionts and host genet performance, as well as weaker associations with treatment. Although dominant symbiont physiology and function contribute to host performance, these findings emphasize the importance of symbiont community diversity and stochasticity as components of host performance. Our findings also suggest that symbiont community diversity metrics may function as indicators of resilience and have potential applications in diverse disciplines from climate change adaptation to agriculture and medicine.}, }
@article {pmid32047292, year = {2020}, author = {Zélé, F and Santos, I and Matos, M and Weill, M and Vavre, F and Magalhães, S}, title = {Endosymbiont diversity in natural populations of Tetranychus mites is rapidly lost under laboratory conditions.}, journal = {Heredity}, volume = {124}, number = {4}, pages = {603-617}, pmid = {32047292}, issn = {1365-2540}, mesh = {Animals ; *Bacteroidetes/genetics ; Female ; Laboratories ; *Rickettsia/genetics ; *Symbiosis ; *Tetranychidae/microbiology ; *Wolbachia/genetics ; }, abstract = {Although the diversity of bacterial endosymbionts in arthropods is well documented, whether and how such diversity is maintained remains an open question. We investigated the temporal changes occurring in the prevalence and composition of endosymbionts after transferring natural populations of Tetranychus spider mites from the field to the laboratory. These populations, belonging to three different Tetranychus species (T. urticae, T. ludeni and T. evansi) carried variable infection frequencies of Wolbachia, Cardinium, and Rickettsia. We report a rapid change of the infection status of these populations after only 6 months of laboratory rearing, with an apparent loss of Rickettsia and Cardinium, while Wolbachia apparently either reached fixation or was lost. We show that Wolbachia had variable effects on host longevity and fecundity, and induced variable levels of cytoplasmic incompatibility (CI) in each fully infected population, despite no sequence divergence in the markers used and full CI rescue between all populations. This suggests that such effects are largely dependent upon the host genotype. Subsequently, we used these data to parameterize a theoretical model for the invasion of CI-inducing symbionts in haplodiploids, which shows that symbiont effects are sufficient to explain their dynamics in the laboratory. This further suggests that symbiont diversity and prevalence in the field are likely maintained by environmental heterogeneity, which is reduced in the laboratory. Overall, this study highlights the lability of endosymbiont infections and draws attention to the limitations of laboratory studies to understand host-symbiont interactions in natural populations.}, }
@article {pmid32043447, year = {2020}, author = {Lechner, AM and Gastager, H and Kern, JM and Wagner, B and Tappe, D}, title = {Case Report: Successful Treatment of a Patient with Microfilaremic Dirofilariasis Using Doxycycline.}, journal = {The American journal of tropical medicine and hygiene}, volume = {102}, number = {4}, pages = {844-846}, pmid = {32043447}, issn = {1476-1645}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; *Dirofilaria repens ; Dirofilariasis/*diagnostic imaging/*therapy ; Doxycycline/*therapeutic use ; Female ; Humans ; Middle Aged ; }, abstract = {We report the case of a 56-year-old woman with microfilaremic dirofilariasis due to Dirofilaria repens, which is a very rare condition in humans. Of note, just one of six large-volume blood samples of this patient was positive for microfilariae. Polymerase chain reaction (PCR) and sequencing of the parasite gene determined the geographic origin of the causative helminth. The patient was treated successfully with doxycycline. This drug was chosen because of the patient's reluctance to the use of ivermectin and to provide an anthelmintic effect by targeting the bacterial endosymbiont Wolbachia present in most filarial species.}, }
@article {pmid32041638, year = {2020}, author = {Ekwudu, O and Devine, GJ and Aaskov, JG and Frentiu, FD}, title = {Wolbachia strain wAlbB blocks replication of flaviviruses and alphaviruses in mosquito cell culture.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {54}, pmid = {32041638}, issn = {1756-3305}, mesh = {Aedes/microbiology/virology ; Alphavirus/*growth &amp; development ; Alphavirus Infections/prevention &amp; control ; Animals ; Cell Line/microbiology/virology ; Dengue/prevention &amp; control ; Flavivirus/*growth &amp; development ; Humans ; Insect Vectors/microbiology/virology ; *Microbial Interactions ; Pest Control, Biological ; Virus Diseases/prevention &amp; control/transmission ; *Virus Replication ; West Nile Fever/prevention &amp; control ; *Wolbachia ; Zika Virus Infection/prevention &amp; control ; }, abstract = {BACKGROUND: Wolbachia pipientis are bacterial endosymbionts of arthropods currently being implemented as biocontrol agents to reduce the global burden of arboviral diseases. Some strains of Wolbachia, when introduced into Aedes aegypti mosquitoes, reduce or block the replication of RNA viruses pathogenic to humans. The wAlbB strain of Wolbachia was originally isolated from Aedes albopictus, and when transinfected into Ae. aegypti, persists in mosquitoes under high temperature conditions longer than other strains. The utility of wAlbB to block a broad spectrum of RNA viruses has received limited attention. Here we test the ability of wAlbB to reduce or block the replication of a range of Flavivirus and Alphavirus species in cell culture.<br><br>METHODS: The C6/36 mosquito cell line was stably infected with the wAlbB strain using the shell-vial technique. The replication of dengue, West Nile and three strains of Zika (genus Flavivirus), and Ross River, Barmah Forest and Sindbis (genus Alphavirus) viruses was compared in wAlbB-infected cells with Wolbachia-free controls. Infectious virus titres were determined using either immunofocus or plaque assays. A general linear model was used to test for significant differences in replication between flaviviruses and alphaviruses.<br><br>RESULTS: Titres of all viruses were significantly reduced in cell cultures infected with wAlbB versus Wolbachia-free controls. The magnitude of reduction in virus yields varied among virus species and, within species, also among the strains utilized.<br><br>CONCLUSION: Our results suggest that wAlbB infection of arthropods could be used to reduce transmission of a wide range of pathogenic RNA viruses.}, }
@article {pmid32035054, year = {2020}, author = {Adenyo, C and Ohya, K and Qiu, Y and Takashima, Y and Ogawa, H and Matsumoto, T and Thu, MJ and Sato, K and Kawabata, H and Katayama, Y and Omatsu, T and Mizutani, T and Fukushi, H and Katakura, K and Nonaka, N and Inoue-Murayama, M and Kayang, B and Nakao, R}, title = {Bacterial and protozoan pathogens/symbionts in ticks infecting wild grasscutters (Thryonomys swinderianus) in Ghana.}, journal = {Acta tropica}, volume = {205}, number = {}, pages = {105388}, doi = {10.1016/j.actatropica.2020.105388}, pmid = {32035054}, issn = {1873-6254}, mesh = {Animals ; Babesia/*isolation &amp; purification ; Bacteria/*isolation &amp; purification ; Female ; Ghana ; Humans ; Ixodes/*microbiology/*parasitology ; Male ; Rodentia/*parasitology ; Theileria/*isolation &amp; purification ; Tick-Borne Diseases/parasitology ; }, abstract = {Ticks and tick-borne pathogens constitute a great threat to livestock production and are a potential health hazard to humans. Grasscutters (Thryonomys swinderianus) are widely hunted for meat in Ghana and many other West and Central African countries. However, tick-borne zoonotic risks posed by wild grasscutters have not been assessed. The objective of this study was to investigate bacterial and protozoan pathogens in ticks infecting wild grasscutters. A total of 81 ticks were collected from three hunted grasscutters purchased from Kantamanto, the central bushmeat market in Accra. Ticks were identified as Ixodes aulacodi and Rhipicephalus sp. based on morphological keys, which were further confirmed by sequencing mitochondrial 16S ribosomal DNA (rDNA) and cytochrome oxidase I (COI) genes of specimens. Protozoan infections were tested by PCR amplifying 18S rDNA of Babesia/Theileria/Hepatozoon, while bacterial infections were evaluated by PCRs or real-time PCRs targeting Anaplasmataceae, Borrelia, spotted fever group rickettsiae, chlamydiae and Candidatus Midichloria mitochondrii. The results of PCR screening showed that 35.5% (27 out of 76) of I. aulacodi were positive for parasite infections. Sequencing analysis of the amplified products gave one identical sequence showing similarity with Babesia spp. reported from Africa. The Ca. M. mitochondrii endosymbiont was present in 85.5% (65 out of 76) of I. aulacodi but not in the five Rhipicephalus ticks. Two Anaplasmataceae bacteria genetically related to Ehrlichia muris and Anaplasma phagocytophilum were also detected in two I. aulacodi. None of the ticks were positive for Borrelia spp., spotted fever group rickettsiae and chlamydiae. Since I. aulacodi on wild grasscutters are potential carriers of tick-borne pathogens, some of which could be of zoonotic potential, rigorous tick control and pathogen analyses should be instituted especially when wild caught grasscutters are being used as foundation stock for breeding.}, }
@article {pmid32034827, year = {2020}, author = {Binetruy, F and Buysse, M and Lejarre, Q and Barosi, R and Villa, M and Rahola, N and Paupy, C and Ayala, D and Duron, O}, title = {Microbial community structure reveals instability of nutritional symbiosis during the evolutionary radiation of Amblyomma ticks.}, journal = {Molecular ecology}, volume = {29}, number = {5}, pages = {1016-1029}, doi = {10.1111/mec.15373}, pmid = {32034827}, issn = {1365-294X}, mesh = {Amblyomma/classification/*microbiology ; Animals ; Bacteria/classification ; *Biological Evolution ; Coxiella ; Francisella ; *Microbiota ; Phylogeny ; Rickettsia ; *Symbiosis ; }, abstract = {Mutualistic interactions with microbes have facilitated the adaptation of major eukaryotic lineages to restricted diet niches. Hence, ticks with their strictly blood-feeding lifestyle are associated with intracellular bacterial symbionts through an essential B vitamin supplementation. In this study, examination of bacterial diversity in 25 tick species of the genus Amblyomma showed that three intracellular bacteria, Coxiella-like endosymbionts (LE), Francisella-LE and Rickettsia, are remarkably common. No other bacterium is as uniformly present in Amblyomma ticks. Almost all Amblyomma species were found to harbour a nutritive obligate symbiont, Coxiella-LE or Francisella-LE, that is able to synthesize B vitamins. However, despite the co-evolved and obligate nature of these mutualistic interactions, the structure of microbiomes does not mirror the Amblyomma phylogeny, with a clear exclusion pattern between Coxiella-LE and Francisella-LE across tick species. Coxiella-LE, but not Francisella-LE, form evolutionarily stable associations with ticks, commonly leading to co-cladogenesis. We further found evidence for symbiont replacements during the radiation of Amblyomma, with recent, and probably ongoing, invasions by Francisella-LE and subsequent replacements of ancestral Coxiella-LE through transient co-infections. Nutritional symbiosis in Amblyomma ticks is thus not a stable evolutionary state, but instead arises from conflicting origins between unrelated but competing symbionts with similar metabolic capabilities.}, }
@article {pmid32030839, year = {2020}, author = {Hundertmark, A and Goodacre, SL and Brookfield, JFY}, title = {Alternative evolutionary outcomes following endosymbiont-mediated selection on male mating preference alleles.}, journal = {Journal of evolutionary biology}, volume = {33}, number = {5}, pages = {653-667}, pmid = {32030839}, issn = {1420-9101}, mesh = {Animals ; Arthropods/*microbiology ; Avoidance Learning ; *Biological Evolution ; Female ; Male ; *Mating Preference, Animal ; *Models, Biological ; Selection, Genetic ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {In many arthropods, intracellular bacteria, such as those of the genus Wolbachia, may spread through host populations as a result of cytoplasmic incompatibility (CI). Here, there is sterility or reduced fertility in crosses between infected males and uninfected females. As the bacterium is maternally inherited, the reduced fertility of uninfected females increases the frequency of the infection. If the transmission fidelity of the bacterium is less than 100%, the bacterium cannot invade from a low frequency, but if its frequency exceeds a threshold, it increases to a high, stable, equilibrium frequency. We explore the expected evolutionary dynamics of mutant alleles that cause their male bearers to avoid mating with uninfected females. For alleles which create this avoidance behaviour conditional upon the male being infected, there is a wide zone of parameter space that allows the preference allele to drive Wolbachia from the population when it would otherwise stably persist. There is also a wide zone of parameter space that allows a joint stable equilibrium for the Wolbachia and a polymorphism for the preference allele. When the male's avoidance of uninfected females is unconditional, the preference allele's effect on Wolbachia frequency is reduced, but there is a narrow range of values for the transmission rate and CI fertility that allow an unconditional preference allele to drive Wolbachia from the population, in a process driven by positive linkage disequilibrium between Wolbachia and the preference allele. The possibility of the evolution of preference could hamper attempts to manipulate wild populations through Wolbachia introductions.}, }
@article {pmid32028994, year = {2020}, author = {Uni, S and Mat Udin, AS and Agatsuma, T and Junker, K and Saijuntha, W and Bunchom, N and Fukuda, M and Martin, C and Lefoulon, E and Labat, A and Khan, FAA and Low, VL and Cheah, PL and Lim, YA and Ramli, R and Belabut, DM and Zainuri, NA and Matsubayashi, M and Omar, H and Bhassu, S and Uga, S and Hashim, R and Takaoka, H and Azirun, MS}, title = {Description, molecular characteristics and Wolbachia endosymbionts of Onchocerca borneensis Uni, Mat Udin &amp; Takaoka n. sp. (Nematoda: Filarioidea) from the Bornean bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae) of Sarawak, Malaysia.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {50}, pmid = {32028994}, issn = {1756-3305}, mesh = {Animals ; Biological Coevolution ; Classification ; Genes, Bacterial ; Genes, Helminth ; Humans ; *Onchocerca/anatomy &amp; histology/classification/microbiology ; Onchocerciasis/transmission/*veterinary ; Onchocerciasis, Ocular/parasitology/transmission ; Phylogeny ; Swine/*parasitology ; Swine Diseases ; Symbiosis ; *Wolbachia/classification/isolation &amp; purification ; Zoonoses/transmission ; }, abstract = {BACKGROUND: The genus Onchocerca Diesing, 1841 includes species of medical importance, such as O. volvulus (Leuckart, 1893), which causes river blindness in the tropics. Recently, zoonotic onchocercosis has been reported in humans worldwide. In Japan, O. dewittei japonica Uni, Bain &amp; Takaoka, 2001 from wild boars is a causative agent for this zoonosis. Many filarioid nematodes are infected with Wolbachia endosymbionts which exhibit various evolutionary relationships with their hosts. While investigating the filarial fauna of Borneo, we discovered an undescribed Onchocerca species in the bearded pig Sus barbatus Müller (Cetartiodactyla: Suidae).<br><br>METHODS: We isolated Onchocerca specimens from bearded pigs and examined their morphology. For comparative material, we collected fresh specimens of O. d. dewittei Bain, Ramachandran, Petter &amp; Mak, 1977 from banded pigs (S. scrofa vittatus Boie) in Peninsular Malaysia. Partial sequences of three different genes (two mitochondrial genes, cox1 and 12S rRNA, and one nuclear ITS region) of these filarioids were analysed. By multi-locus sequence analyses based on six genes (16S rDNA, ftsZ, dnaA, coxA, fbpA and gatB) of Wolbachia, we determined the supergroups in the specimens from bearded pigs and those of O. d. dewittei.<br><br>RESULTS: Onchocerca borneensis Uni, Mat Udin &amp; Takaoka n. sp. is described on the basis of morphological characteristics and its genetic divergence from congeners. Molecular characteristics of the new species revealed its close evolutionary relationship with O. d. dewittei. Calculated p-distance for the cox1 gene sequences between O. borneensis n. sp. and O. d. dewittei was 5.9%, while that between O. d. dewittei and O. d. japonica was 7.6%. No intraspecific genetic variation was found for the new species. Wolbachia strains identified in the new species and O. d. dewittei belonged to supergroup C and are closely related.<br><br>CONCLUSIONS: Our molecular analyses of filarioids from Asian suids indicate that the new species is sister to O. d. dewittei. On the basis of its morphological and molecular characteristics, we propose to elevate O. d. japonica to species level as O. japonica Uni, Bain &amp; Takaoka, 2001. Coevolutionary relationships exist between the Wolbachia strains and their filarial hosts in Borneo and Peninsular Malaysia.}, }
@article {pmid32027869, year = {2020}, author = {Fuess, LE and Butler, CC and Brandt, ME and Mydlarz, LD}, title = {Investigating the roles of transforming growth factor-beta in immune response of Orbicella faveolata, a scleractinian coral.}, journal = {Developmental and comparative immunology}, volume = {107}, number = {}, pages = {103639}, doi = {10.1016/j.dci.2020.103639}, pmid = {32027869}, issn = {1879-0089}, mesh = {Animals ; Anthozoa/*immunology ; Caribbean Region ; Cells, Cultured ; Coral Reefs ; Dinoflagellida ; Immunity ; Immunomodulation ; Signal Transduction ; Symbiosis ; Transcriptome ; Transforming Growth Factor beta/*metabolism ; }, abstract = {Symbiotic relationships range from parasitic to mutualistic, yet all endosymbionts face similar challenges, including evasion of host immunity. Many symbiotic organisms have evolved similar mechanisms to face these challenges, including manipulation of the host's transforming growth factor-beta (TGFβ) pathway. Here we investigate the TGFβ pathway in scelaractinian corals which are dependent on symbioses with dinoflagellates from the family Symbiodiniaceae. Using the Caribbean coral, Orbicella faveolata, we explore the effects of enhancement and inhibition of the TGFβ pathway on host gene expression. Following transcriptomic analyses, we demonstrated limited effects of pathway manipulation in absence of immune stimulation. However, manipulation of the TGFβ pathway significantly affects the subsequent ability of host corals to mount an immune response. Enhancement of the TGFβ pathway eliminates transcriptomic signatures of host coral immune response, while inhibition of the pathway maintains the response. This is, to our knowledge, the first evidence of an immunomodulatory role for TGFβ in a scelaractinian coral. These findings suggest variation in TGFβ signaling may have implications in the face of increasing disease prevelance. Our results suggest that the TGFβ pathway can modulate tradeoffs between symbiosis and immunity. Further study of links between symbiosis, TGFβ, and immunity is needed to better understand the ecological implications of these findings.}, }
@article {pmid32025311, year = {2020}, author = {Potts, R and Molina, I and Sheele, JM and Pietri, JE}, title = {Molecular detection of Rickettsia infection in field-collected bed bugs.}, journal = {New microbes and new infections}, volume = {34}, number = {}, pages = {100646}, pmid = {32025311}, issn = {2052-2975}, abstract = {Bed bugs are now one of the most prevalent human-associated, blood-feeding pests in the urban world, but few studies of their association with human pathogens have been conducted since their resurgence. Here, we used PCR to screen samples of field-collected bed bugs (Cimex spp.) for the presence of Rickettsia bacteria and we describe the first detection of an uncharacterized Rickettsia in Cimex lectularius in nature. Rickettsia was detected in 5/39 (12.8%) of the bed bug samples tested. In particular, three pools from the USA and two individual insects from the UK were positive for Rickettsia DNA. Sequencing and analysis of a fragment of the citrate synthase gene (gltA) from positive samples from each country revealed that the Rickettsia detected in both were identical and were closely related to a Rickettsia previously detected in the rat flea Nosopsyllus laeviceps. Additional experiments indicated that the Rickettsia localizes to multiple tissues in the bed bug and reaches high titres. Attempts were made to infect mammalian cells in culture but these efforts were inconclusive. Our findings suggest that Rickettsia are secondary endosymbionts of bed bugs and have potential implications for both bed bug control and public health. However, further investigation is required to determine the pathogenicity of this Rickettsia, its transmission mechanisms, and its contributions to bed bug physiology.}, }
@article {pmid32024068, year = {2020}, author = {de Jesus, CP and Dias, FBS and Villela, DMA and Maciel-de-Freitas, R}, title = {Ovitraps Provide a Reliable Estimate of Wolbachia Frequency during wMelBr Strain Deployment in a Geographically Isolated Aedes aegypti Population.}, journal = {Insects}, volume = {11}, number = {2}, pages = {}, pmid = {32024068}, issn = {2075-4450}, abstract = {Deployment of Aedes aegypti mosquitoes carrying the endosymbiont bacterium Wolbachia has been identified as a promising strategy to reduce dengue, chikungunya, and Zika transmission. We investigated whether sampling larvae from ovitraps can provide reliable estimates on Wolbachia frequency during releases, as compared to the expensive adult-based BG-Sentinel. We conducted pilot releases in a semi-field system (SFS) divided into six cages of 21 m[2], each with five ovitraps. Five treatments were chosen to represent different points of a hypothetical invasion curve: 10%, 25%, 50%, 75%, and 90% of Wolbachia frequency. Collected eggs were counted and hatched, and the individuals from a net sample of 27% of larvae per treatment were screened for Wolbachia presence by RT-qPCR. Ovitrap positioning had no effect on egg hatching rate. Treatment strongly affected the number of eggs collected and also the hatching rate, especially when Wolbachia was at a 10% frequency. A second observation was done during the release of Wolbachia in Rio under a population replacement approach when bacterium frequency was estimated using 30 BG-Sentinel traps and 45 ovitraps simultaneously. By individually screening 35% (N = 3904) of larvae collected by RT-qPCR, we were able to produce a similar invasion curve to the one observed when all adults were individually screened. If sampling is reduced to 20%, monitoring Wolbachia frequency with 45 ovitraps would be roughly half the cost of screening all adult mosquitoes captured by 30 BG-Sentinels. Our findings support the scale-up of Wolbachia releases, especially in areas with limited resources to afford massive trapping with BG-Sentinel traps.}, }
@article {pmid32008576, year = {2020}, author = {Osman, EO and Suggett, DJ and Voolstra, CR and Pettay, DT and Clark, DR and Pogoreutz, C and Sampayo, EM and Warner, ME and Smith, DJ}, title = {Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities.}, journal = {Microbiome}, volume = {8}, number = {1}, pages = {8}, pmid = {32008576}, issn = {2049-2618}, mesh = {Acclimatization ; Animals ; Anthozoa/*microbiology ; Bacteria/*classification ; Coral Reefs ; Dinoflagellida/classification/*physiology ; *Host Specificity ; Hot Temperature ; Indian Ocean ; *Microbiota ; *Symbiosis ; }, abstract = {BACKGROUND: The capacity of reef-building corals to tolerate (or adapt to) heat stress is a key factor determining their resilience to future climate change. Changes in coral microbiome composition (particularly for microalgal endosymbionts and bacteria) is a potential mechanism that may assist corals to thrive in warm waters. The northern Red Sea experiences extreme temperatures anomalies, yet corals in this area rarely bleach suggesting possible refugia to climate change. However, the coral microbiome composition, and how it relates to the capacity to thrive in warm waters in this region, is entirely unknown.<br><br>RESULTS: We investigated microbiomes for six coral species (Porites nodifera, Favia favus, Pocillopora damicornis, Seriatopora hystrix, Xenia umbellata, and Sarcophyton trocheliophorum) from five sites in the northern Red Sea spanning 4&#xb0; of latitude&#xa0;and summer mean temperature ranges from 26.6&#x2009;&#xb0;C to 29.3&#x2009;&#xb0;C. A total of 19 distinct dinoflagellate endosymbionts were identified as belonging to three genera in the family Symbiodiniaceae (Symbiodinium, Cladocopium, and Durusdinium). Of these, 86% belonged to the genus Cladocopium, with notably five novel types (19%). The endosymbiont community showed a high degree of host-specificity despite the latitudinal gradient. In contrast, the diversity and composition of bacterial communities of the surface mucus layer (SML)-a compartment particularly sensitive to environmental change-varied significantly between sites, however for any given coral was species-specific.<br><br>CONCLUSION: The conserved endosymbiotic community&#xa0;suggests high physiological plasticity to support holobiont productivity&#xa0;across the different latitudinal regimes. Further, the presence of five novel algal endosymbionts suggests selection of certain genotypes (or genetic adaptation) within the semi-isolated Red Sea. In contrast, the dynamic composition of bacteria associated&#xa0;with&#xa0;the SML across sites may contribute to&#xa0;holobiont&#xa0;function and broaden the ecological&#xa0;niche. In doing so, SML bacterial communities may aid holobiont local acclimatization (or adaptation) by readily responding to changes in the host environment. Our study provides novel insight about the selective and endemic nature of coral microbiomes along the northern Red Sea refugia.}, }
@article {pmid32008087, year = {2020}, author = {Zachar, I and Boza, G}, title = {Endosymbiosis before eukaryotes: mitochondrial establishment in protoeukaryotes.}, journal = {Cellular and molecular life sciences : CMLS}, volume = {77}, number = {18}, pages = {3503-3523}, pmid = {32008087}, issn = {1420-9071}, mesh = {Biological Evolution ; Eukaryotic Cells/metabolism ; Microbial Consortia ; Mitochondria/*metabolism ; Mitochondrial ADP, ATP Translocases/metabolism ; Plastids ; Prokaryotic Cells/*metabolism ; *Symbiosis ; }, abstract = {Endosymbiosis and organellogenesis are virtually unknown among prokaryotes. The single presumed example is the endosymbiogenetic origin of mitochondria, which is hidden behind the event horizon of the last eukaryotic common ancestor. While eukaryotes are monophyletic, it is unlikely that during billions of years, there were no other prokaryote-prokaryote endosymbioses as symbiosis is extremely common among prokaryotes, e.g., in biofilms. Therefore, it is even more precarious to draw conclusions about potentially existing (or once existing) prokaryotic endosymbioses based on a single example. It is yet unknown if the bacterial endosymbiont was captured by a prokaryote or by a (proto-)eukaryote, and if the process of internalization was parasitic infection, slow engulfment, or phagocytosis. In this review, we accordingly explore multiple mechanisms and processes that could drive the evolution of unicellular microbial symbioses with a special attention to prokaryote-prokaryote interactions and to the mitochondrion, possibly the single prokaryotic endosymbiosis that turned out to be a major evolutionary transition. We investigate the ecology and evolutionary stability of inter-species microbial interactions based on dependence, physical proximity, cost-benefit budget, and the types of benefits, investments, and controls. We identify challenges that had to be conquered for the mitochondrial host to establish a stable eukaryotic lineage. Any assumption about the initial interaction of the mitochondrial ancestor and its contemporary host based solely on their modern relationship is rather perilous. As a result, we warn against assuming an initial mutually beneficial interaction based on modern mitochondria-host cooperation. This assumption is twice fallacious: (i) endosymbioses are known to evolve from exploitative interactions and (ii) cooperativity does not necessarily lead to stable mutualism. We point out that the lack of evidence so far on the evolution of endosymbiosis from mutual syntrophy supports the idea that mitochondria emerged from an exploitative (parasitic or phagotrophic) interaction rather than from syntrophy.}, }
@article {pmid31997547, year = {2020}, author = {Wang, HL and Lei, T and Wang, XW and Maruthi, MN and Zhu, DT and Cameron, SL and Rao, Q and Shan, HW and Colvin, J and Liu, YQ and Liu, SS}, title = {A newly recorded Rickettsia of the Torix group is a recent intruder and an endosymbiont in the whitefly Bemisia tabaci.}, journal = {Environmental microbiology}, volume = {22}, number = {4}, pages = {1207-1221}, doi = {10.1111/1462-2920.14927}, pmid = {31997547}, issn = {1462-2920}, support = {517000-X91609//China Postdoctoral Science Special Foundation/International ; 517000-X91502//Chinese Postdoctoral Science Foundation/International ; OPP1058938/GATES/Bill &amp; Melinda Gates Foundation/United States ; }, mesh = {Animals ; Asia ; Female ; Hemiptera/*microbiology ; Male ; Phenotype ; Phylogeny ; Rickettsia/*classification/genetics/isolation &amp; purification/physiology ; *Symbiosis ; }, abstract = {The bacterium Rickettsia is found widely in phytophagous insects and often exerts profound effects on the phenotype and fitness of its hosts. Here, we decrypt a new, independent, phylogenetically ancient Torix Rickettsia endosymbiont found constantly in a laboratory line of an economically important insect Asia II 7, a putative species of the Bemisia tabaci whitefly complex (Hemiptera: Aleyrodidae), and occasionally in field whitefly populations. This new Rickettsia distributes throughout the body of its whitefly host. Genetically, compared to Rickettsia_bellii_MEAM1 found earlier in whiteflies, the new Rickettsia species has more gene families and pathways, which may be important factors in shaping specific symbiotic relationships. We propose the name 'Candidatus Rickettsia_Torix_Bemisia_tabaci (RiTBt)' for this new endosymbiont associated with whiteflies. Comparative genomic analyses indicate that RiTBi may be a relatively recent intruder in whiteflies given its low abundance in the field and relatively larger genome compared to Rickettsia_bellii_MEAM1.}, }
@article {pmid31997503, year = {2020}, author = {Camp, EF and Kahlke, T and Nitschke, MR and Varkey, D and Fisher, NL and Fujise, L and Goyen, S and Hughes, DJ and Lawson, CA and Ros, M and Woodcock, S and Xiao, K and Leggat, W and Suggett, DJ}, title = {Revealing changes in the microbiome of Symbiodiniaceae under thermal stress.}, journal = {Environmental microbiology}, volume = {22}, number = {4}, pages = {1294-1309}, doi = {10.1111/1462-2920.14935}, pmid = {31997503}, issn = {1462-2920}, mesh = {Animals ; Bacteria/genetics ; Dinoflagellida/genetics/*microbiology ; *Heat-Shock Response ; *Microbiota ; RNA, Ribosomal, 16S ; }, abstract = {Symbiodiniaceae are a diverse family of marine dinoflagellates, well known as coral endosymbionts. Isolation and in vitro culture of Symbiodiniaceae strains for physiological studies is a widely adopted tool, especially in the context of understanding how environmental stress perturbs Symbiodiniaceae cell functioning. While the bacterial microbiomes of corals often correlate with coral health, the bacterial communities co-cultured with Symbiodiniaceae isolates have been largely overlooked, despite the potential of bacteria to significantly influence the emergent physiological properties of Symbiodiniaceae cultures. We examined the physiological response to heat stress by Symbiodiniaceae isolates (spanning three genera) with well-described thermal tolerances, and combined these observations with matched changes in bacterial composition and abundance through 16S rRNA metabarcoding. Under thermal stress, there were Symbiodiniaceae strain-specific changes in maximum quantum yield of photosystem II (proxy for health) and growth rates that were accompanied by changes in the relative abundance of multiple Symbiodiniaceae-specific bacteria. However, there were no Symbiodiniaceae-independent signatures of bacterial community reorganisation under heat stress. Notably, the thermally tolerant Durusdinium trenchii (ITS2 major profile D1a) had the most stable bacterial community under heat stress. Ultimately, this study highlights the complexity of Symbiodiniaceae-bacteria interactions and provides a first step towards uncoupling their relative contributions towards Symbiodiniaceae physiological functioning.}, }
@article {pmid31993121, year = {2020}, author = {Maor-Landaw, K and van Oppen, MJH and McFadden, GI}, title = {Symbiotic lifestyle triggers drastic changes in the gene expression of the algal endosymbiont Breviolum minutum (Symbiodiniaceae).}, journal = {Ecology and evolution}, volume = {10}, number = {1}, pages = {451-466}, pmid = {31993121}, issn = {2045-7758}, abstract = {Coral-dinoflagellate symbiosis underpins the evolutionary success of corals reefs. Successful exchange of molecules between the cnidarian host and the Symbiodiniaceae algae enables the mutualistic partnership. The algae translocate photosynthate to their host in exchange for nutrients and shelter. The photosynthate must traverse multiple membranes, most likely facilitated by transporters. Here, we compared gene expression profiles of cultured, free-living Breviolum minutum with those of the homologous symbionts freshly isolated from the sea anemone Exaiptasia diaphana, a widely used model for coral hosts. Additionally, we assessed expression levels of a list of candidate host transporters of interest in anemones with and without symbionts. Our transcriptome analyses highlight the distinctive nature of the two algal life stages, with many gene expression level changes correlating to the different morphologies, cell cycles, and metabolisms adopted in hospite versus free-living. Morphogenesis-related genes that likely underpin the metamorphosis process observed when symbionts enter a host cell were up-regulated. Conversely, many down-regulated genes appear to be indicative of the protective and confined nature of the symbiosome. Our results emphasize the significance of transmembrane transport to the symbiosis, and in particular of ammonium and sugar transport. Further, we pinpoint and characterize candidate transporters-predicted to be localized variously to the algal plasma membrane, the host plasma membrane, and the symbiosome membrane-that likely serve pivotal roles in the interchange of material during symbiosis. Our study provides new insights that expand our understanding of the molecular exchanges that underpin the cnidarian-algal symbiotic relationship.}, }
@article {pmid31991915, year = {2020}, author = {Gondard, M and Temmam, S and Devillers, E and Pinarello, V and Bigot, T and Chrétien, D and Aprelon, R and Vayssier-Taussat, M and Albina, E and Eloit, M and Moutailler, S}, title = {RNA Viruses of Amblyomma variegatum and Rhipicephalus microplus and Cattle Susceptibility in the French Antilles.}, journal = {Viruses}, volume = {12}, number = {2}, pages = {}, pmid = {31991915}, issn = {1999-4915}, mesh = {Animals ; Antibodies, Viral/blood ; Cattle/immunology ; *Cattle Diseases/immunology/parasitology ; Disease Susceptibility ; Flaviviridae/genetics/immunology/*isolation &amp; purification ; Genome, Viral ; Ixodidae/*virology ; Martinique ; Phylogeny ; RNA Viruses/*classification/genetics/immunology/*isolation &amp; purification ; RNA, Viral/analysis/genetics ; Rhipicephalus/*virology ; Seroepidemiologic Studies ; Tick Infestations/immunology/*veterinary ; West Indies ; }, abstract = {Ticks transmit a wide variety of pathogens including bacteria, parasites and viruses. Over the last decade, numerous novel viruses have been described in arthropods, including ticks, and their characterization has provided new insights into RNA virus diversity and evolution. However, little is known about their ability to infect vertebrates. As very few studies have described the diversity of viruses present in ticks from the Caribbean, we implemented an RNA-sequencing approach on Amblyomma variegatum and Rhipicephalus microplus ticks collected from cattle in Guadeloupe and Martinique. Among the viral communities infecting Caribbean ticks, we selected four viruses belonging to the Chuviridae, Phenuiviridae and Flaviviridae families for further characterization and designing antibody screening tests. While viral prevalence in individual tick samples revealed high infection rates, suggesting a high level of exposure of Caribbean cattle to these viruses, no seropositive animals were detected. These results suggest that the Chuviridae- and Phenuiviridae-related viruses identified in the present study are more likely tick endosymbionts, raising the question of the epidemiological significance of their occurrence in ticks, especially regarding their possible impact on tick biology and vector capacity. The characterization of these viruses might open the door to new ways of preventing and controlling tick-borne diseases.}, }
@article {pmid31987066, year = {2020}, author = {Bello, VH and Watanabe, LFM and Fusco, LM and De Marchi, BR and da Silva, FB and Gorayeb, ES and Moura, MF and de Souza, IM and Muller, C and Salas, FJS and Yuki, VA and Bueno, RCOF and Pavan, MA and Krause-Sakate, R}, title = {Outbreaks of Bemisia tabaci Mediterranean species in vegetable crops in São Paulo and Paraná States, Brazil.}, journal = {Bulletin of entomological research}, volume = {110}, number = {4}, pages = {487-496}, doi = {10.1017/S0007485319000841}, pmid = {31987066}, issn = {1475-2670}, mesh = {Animals ; Begomovirus/isolation &amp; purification ; Brazil ; Crinivirus/isolation &amp; purification ; *Crops, Agricultural ; Disease Outbreaks ; Hemiptera/*classification/genetics/*virology ; Introduced Species ; Microsatellite Repeats ; Plant Diseases/virology ; Symbiosis ; Vegetables ; }, abstract = {The whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important agricultural pests and virus vectors worldwide. Bemisia tabaci is considered a complex of cryptic species with at least 44 species. Among them, the species Middle East-Asia Minor 1 (MEAM1, formerly B biotype) and Mediterranean (MED, formerly Q biotype) are the most important, and they have attained global status. In Brazil, MEAM1 was first reported in the 1990s and is currently the predominant species in the country, meanwhile, MED was recently reported in the South and Southeast regions and was found to be mainly associated with ornamental plants. Currently, an increasing problem in the management of whitefly infestations in greenhouses associated with bell pepper was observed in São Paulo State, Brazil. The whiteflies were collected and identified based on a microsatellite locus (primer pair BEM23F and BEM23R) and the mitochondrial cytochrome oxidase I gene followed by restriction fragment length polymorphism analysis and sequencing. We observed that MED was the predominant species collected on bell pepper, but it was also found on tomato, cucumber, eggplant, and weeds grown in greenhouses. In open field, we found MED on tomatoes, bell peppers, and eggplants. In addition, MED was identified in Goiás State in association with ornamental plants. The begomovirus Tomato severe rugose virus and the crinivirus Tomato chlorosis virus was detected on bell pepper and tomato, respectively. Only MED specimens were found associated with the virus-infected plants. Moreover, we also investigated the endosymbionts present in the MED whiteflies. The collected populations of B. tabaci MED harbored a diversity of secondary endosymbionts, with Hamiltonella (H) found predominantly in 89 specimens of the 129 tested. These results represent a new concern for Brazilian agriculture, especially for the management of the newly introduced whitefly MED species, which must be implemented to limit the spreading and establishment of this pest in different crops in this country.}, }
@article {pmid31986143, year = {2020}, author = {Ehrens, A and Lunde, CS and Jacobs, RT and Struever, D and Koschel, M and Frohberger, SJ and Lenz, F and Fendler, M and Turner, JD and Ward, SA and Taylor, MJ and Freund, YR and Stefanakis, R and Easom, E and Li, X and Plattner, JJ and Hoerauf, A and Hübner, MP}, title = {In vivo efficacy of the boron-pleuromutilin AN11251 against Wolbachia of the rodent filarial nematode Litomosoides sigmodontis.}, journal = {PLoS neglected tropical diseases}, volume = {14}, number = {1}, pages = {e0007957}, pmid = {31986143}, issn = {1935-2735}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Boron ; Diterpenes/*pharmacology ; Doxycycline/pharmacology ; Female ; Filariasis/*drug therapy/microbiology ; Filarioidea/*drug effects/microbiology ; Mice, Inbred BALB C ; Polycyclic Compounds/*pharmacology ; Rifampin/pharmacology ; Symbiosis ; Wolbachia/*drug effects ; }, abstract = {The elimination of filarial diseases such as onchocerciasis and lymphatic filariasis is hampered by the lack of a macrofilaricidal-adult worm killing-drug. In the present study, we tested the in vivo efficacy of AN11251, a boron-pleuromutilin that targets endosymbiotic Wolbachia bacteria from filarial nematodes and compared its efficacy to doxycycline and rifampicin. Doxycycline and rifampicin were previously shown to deplete Wolbachia endosymbionts leading to a permanent sterilization of the female adult filariae and adult worm death in human clinical studies. Twice-daily oral treatment of Litomosoides sigmodontis-infected mice with 200 mg/kg AN11251 for 10 days achieved a Wolbachia depletion > 99.9% in the adult worms, exceeding the Wolbachia reduction by 10-day treatments with bioequivalent human doses of doxycycline and a similar reduction as high-dose rifampicin (35 mg/kg). Wolbachia reductions of > 99% were also accomplished by 14 days of oral AN11251 at a lower twice-daily dose (50 mg/kg) or once-per-day 200 mg/kg AN11251 treatments. The combinations tested of AN11251 with doxycycline had no clear beneficial impact on Wolbachia depletion, achieving a > 97% Wolbachia reduction with 7 days of treatment. These results indicate that AN11251 is superior to doxycycline and comparable to high-dose rifampicin in the L. sigmodontis mouse model, allowing treatment regimens as short as 10-14 days. Therefore, AN11251 represents a promising pre-clinical candidate that was identified in the L. sigmodontis model, and could be further evaluated and developed as potential clinical candidate for human lymphatic filariasis and onchocerciasis.}, }
@article {pmid31978335, year = {2020}, author = {George, EE and Husnik, F and Tashyreva, D and Prokopchuk, G and Horák, A and Kwong, WK and Lukeš, J and Keeling, PJ}, title = {Highly Reduced Genomes of Protist Endosymbionts Show Evolutionary Convergence.}, journal = {Current biology : CB}, volume = {30}, number = {5}, pages = {925-933.e3}, doi = {10.1016/j.cub.2019.12.070}, pmid = {31978335}, issn = {1879-0445}, mesh = {Euglenozoa/microbiology ; *Evolution, Molecular ; *Genome, Bacterial ; Holosporaceae/*genetics ; Rickettsiaceae/*genetics ; Symbiosis ; }, abstract = {Genome evolution in bacterial endosymbionts is notoriously extreme: the combined effects of strong genetic drift and unique selective pressures result in highly reduced genomes with distinctive adaptations to hosts [1-4]. These processes are mostly known from animal endosymbionts, where nutritional endosymbioses represent the best-studied systems. However, eukaryotic microbes, or protists, also harbor diverse bacterial endosymbionts, but their genome reduction and functional relationships with their hosts are largely unexplored [5-7]. We sequenced the genomes of four bacterial endosymbionts from three species of diplonemids, poorly studied but abundant and diverse heterotrophic protists [8-12]. The endosymbionts come from two bacterial families, Rickettsiaceae and Holosporaceae, that have invaded two families of diplonemids, and their genomes have converged on an extremely small size (605-632 kilobase pairs [kbp]), similar gene content (e.g., metabolite transporters and secretion systems), and reduced metabolic potential (e.g., loss of energy metabolism). These characteristics are generally found in both families, but the diplonemid endosymbionts have evolved greater extremes in parallel. They possess modified type VI secretion systems that could function in manipulating host metabolism or other intracellular interactions. Finally, modified cellular machinery like the ATP synthase without oxidative phosphorylation, and the reduced flagellar apparatus present in some diplonemid endosymbionts and nutritional animal endosymbionts, indicates that intracellular mechanisms have converged in bacterial endosymbionts with various functions and from different eukaryotic hosts across the tree of life.}, }
@article {pmid31976829, year = {2020}, author = {Livengood, J and Hutchinson, ML and Thirumalapura, N and Tewari, D}, title = {Detection of Babesia, Borrelia, Anaplasma, and Rickettsia spp. in Adult Black-Legged Ticks (Ixodes scapularis) from Pennsylvania, United States, with a Luminex Multiplex Bead Assay.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {20}, number = {6}, pages = {406-411}, doi = {10.1089/vbz.2019.2551}, pmid = {31976829}, issn = {1557-7759}, mesh = {Anaplasma/classification/*isolation &amp; purification ; Animals ; Babesia/*isolation &amp; purification ; Borrelia/classification/*isolation &amp; purification ; DNA/genetics ; Ixodes/*microbiology ; Pennsylvania ; Polymerase Chain Reaction/*methods ; Rickettsia/classification/*isolation &amp; purification ; }, abstract = {Ixodes scapularis, the black-legged tick, harbors multiple organisms and transmits several pathogens to animals and humans. To determine the presence of tick-borne microorganisms carried by I. scapularis in Pennsylvania, 299 adult I. scapularis ticks were collected from across the state and tested with a multiplex bead panel targeting 20 microorganisms. The Luminex bead-based xMAP[®] MultiFLEX Mega Tick Panel detected microorganisms in these ticks, including Anaplasma spp. (1.7%), Borrelia spp. (45.8%), Babesia spp. (16.1%), and Rickettsia spp. (22.1%) at the genera level and identified Anaplasma phagocytophilum (1.7%), Babesia microti (0.7%), Borrelia burgdorferi sensu stricto (45.5%), Borrelia miyamotoi (0.3%), and Rickettsia parkeri (0.7%) at the species level. Babesia spp. reactivity was found to be due to Ba. odocoilei, and Rickettsia spp. reactivity was mainly due to rickettsial endosymbionts.}, }
@article {pmid31976537, year = {2020}, author = {Pérez-Alonso, MM and Guerrero-Galán, C and Scholz, SS and Kiba, T and Sakakibara, H and Ludwig-Müller, J and Krapp, A and Oelmüller, R and Vicente-Carbajosa, J and Pollmann, S}, title = {Harnessing symbiotic plant-fungus interactions to unleash hidden forces from extreme plant ecosystems.}, journal = {Journal of experimental botany}, volume = {71}, number = {13}, pages = {3865-3877}, pmid = {31976537}, issn = {1460-2431}, mesh = {Basidiomycota ; *Climate Change ; *Ecosystem ; Europe ; Fungi ; }, abstract = {Global climate change is arguably one of the biggest threats of modern times and has already led to a wide range of impacts on the environment, economy, and society. Owing to past emissions and climate system inertia, global climate change is predicted to continue for decades even if anthropogenic greenhouse gas emissions were to stop immediately. In many regions, such as central Europe and the Mediterranean region, the temperature is likely to rise by 2-5 °C and annual precipitation is predicted to decrease. Expected heat and drought periods followed by floods, and unpredictable growing seasons, are predicted to have detrimental effects on agricultural production systems, causing immense economic losses and food supply problems. To mitigate the risks of climate change, agricultural innovations counteracting these effects need to be embraced and accelerated. To achieve maximum improvement, the required agricultural innovations should not focus only on crops but rather pursue a holistic approach including the entire ecosystem. Over millions of years, plants have evolved in close association with other organisms, particularly soil microbes that have shaped their evolution and contemporary ecology. Many studies have already highlighted beneficial interactions among plants and the communities of microorganisms with which they coexist. Questions arising from these discoveries are whether it will be possible to decipher a common molecular pattern and the underlying biochemical framework of interspecies communication, and whether such knowledge can be used to improve agricultural performance under environmental stress conditions. In this review, we summarize the current knowledge of plant interactions with fungal endosymbionts found in extreme ecosystems. Special attention will be paid to the interaction of plants with the symbiotic root-colonizing endophytic fungus Serendipita indica, which has been developed as a model system for beneficial plant-fungus interactions.}, }
@article {pmid31973172, year = {2020}, author = {Seo, MG and Kwon, OD and Kwak, D}, title = {Molecular and Phylogenetic Analysis of Tick-Borne Pathogens in Ticks Parasitizing Native Korean Goats (Capra hircus coreanae) in South Korea.}, journal = {Pathogens (Basel, Switzerland)}, volume = {9}, number = {2}, pages = {}, pmid = {31973172}, issn = {2076-0817}, abstract = {Tick-borne pathogens (TBPs) are considered zoonotic re-emerging pathogens, with ticks playing important roles in their transmission and ecology. Previous studies in South Korea have examined TBPs residing in ticks; however, there is no phylogenetic information on TBPs in ticks parasitizing native Korean goat (NKG; Capra hircus coreanae). The present study assessed the prevalence, risk factors, and co-infectivity of TBPs in ticks parasitizing NKGs. In total, 107 hard ticks, including Haemaphysalis longicornis, Ixodes nipponensis, and Haemaphysalis flava, were obtained from NKGs in South Korea between 2016 and 2019. In 40 tested tick pools, genes for four TBPs, namely Coxiella-like endosymbiont (CLE, 5.0%), Candidatus Rickettsia longicornii (45.0%), Anaplasma bovis (2.5%), and Theileria luwenshuni (5.0%) were detected. Ehrlichia, Bartonella spp., and severe fever with thrombocytopenia syndrome virus were not detected. To our knowledge, this is the first study to report CLE and T. luwenshuni in H. flava ticks in South Korea. Considering the high prevalence of Candidatus R. longicornii in ticks parasitizing NKGs, there is a possibility of its transmission from ticks to animals and humans. NKG ticks might be maintenance hosts for TBPs, and we recommend evaluation of the potential public health threat posed by TBP-infected ticks.}, }
@article {pmid31971489, year = {2020}, author = {Pokutnaya, D and Molaei, G and Weinberger, DM and Vossbrinck, CR and Diaz, AJ}, title = {Prevalence of Infection and Co-Infection and Presence of Rickettsial Endosymbionts in Ixodes Scapularis (Acari: Ixodidae) in Connecticut, USA.}, journal = {The Journal of parasitology}, volume = {106}, number = {1}, pages = {30-37}, pmid = {31971489}, issn = {1937-2345}, support = {U01 CK000509/CK/NCEZID CDC HHS/United States ; }, mesh = {Anaplasma phagocytophilum/physiology ; Animals ; Arachnid Vectors/*microbiology ; Babesia/physiology ; Babesia microti/physiology ; Borrelia burgdorferi/physiology ; Connecticut/epidemiology ; Female ; Ixodes/*microbiology ; Nymph/parasitology ; Prevalence ; Rickettsia/*physiology ; *Symbiosis ; Tick-Borne Diseases/epidemiology/*transmission ; }, abstract = {Ixodes scapularis is currently known to transmit 7 pathogens responsible for Lyme disease, anaplasmosis, babesiosis, tick-borne relapsing fever, ehrlichiosis, and Powassan encephalitis. Ixodes scapularis can also be colonized by endosymbiotic bacteria including those in the genus of Rickettsia. We screened 459 I. scapularis ticks submitted to the Connecticut Agricultural Experiment Station Tick Testing Laboratory with the objectives to (1) examine differences in infection prevalence of Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, and Borrelia miyamotoi, (2) evaluate whether prevalence of co-infections occur at the same frequency that would be expected based on single infection, and (3) determine the presence of rickettsial endosymbionts in I. scapularis. The prevalence of infection in I. scapularis was highest with Bo. burgdorferi sensu lato (nymph = 45.8%; female = 47.0%), followed by A. phagocytophilum (nymph = 4.0%; female = 6.9%), Ba. microti (nymph = 5.7%; female = 4.7%), and Bo. miyamotoi (nymph = 0%; female = 7.3%). We also identified rickettsial endosymbionts in 93.3% of I. scapularis. Nymphs were significantly more likely to be infected with Bo. burgdorferi if they were infected with Ba. microti, whereas adult females were significantly more likely to be infected with Bo. burgdorferi if they were infected with A. phagocytophilum. Our study suggests that the infection prevalence of Bo. burgdorferi is not independent of other co-circulating pathogens and that there is a substantially higher infection of Bo. miyamotoi in I. scapularis females compared with nymphs in this study. High prevalence of infection and co-infection with multiple pathogens in I. scapularis highlights the public health consequences in Connecticut, a state endemic for Lyme and other tick-borne diseases.}, }
@article {pmid31964724, year = {2020}, author = {Motone, K and Takagi, T and Aburaya, S and Miura, N and Aoki, W and Ueda, M}, title = {A Zeaxanthin-Producing Bacterium Isolated from the Algal Phycosphere Protects Coral Endosymbionts from Environmental Stress.}, journal = {mBio}, volume = {11}, number = {1}, pages = {}, pmid = {31964724}, issn = {2150-7511}, mesh = {Animals ; Anthozoa/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification/*metabolism ; Microbiota ; Open Reading Frames ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Zeaxanthins/*biosynthesis ; }, abstract = {Reef-building corals form a complex consortium with photosynthetic algae in the family Symbiodiniaceae and bacteria, collectively termed the coral holobiont. These bacteria are hypothesized to be involved in the stress resistance of the coral holobiont, but their functional roles remain largely elusive. Here, we show that cultured Symbiodiniaceae algae isolated from the reef-building coral Galaxea fascicularis are associated with novel bacteria affiliated with the family Flavobacteriaceae Antibiotic treatment eliminated the bacteria from cultured Symbiodiniaceae, resulting in a decreased maximum quantum yield of PSII (variable fluorescence divided by maximum fluorescence [Fv/Fm]) and an increased production of reactive oxygen species (ROS) under thermal and light stresses. We then isolated this bacterial strain, named GF1. GF1 inoculation in the antibiotic-treated Symbiodiniaceae cultures restored the Fv/Fm and reduced the ROS production. Furthermore, we found that GF1 produces the carotenoid zeaxanthin, which possesses potent antioxidant activity. Zeaxanthin supplementation to cultured Symbiodiniaceae ameliorated the Fv/Fm and ROS production, suggesting that GF1 mitigates thermal and light stresses in cultured Symbiodiniaceae via zeaxanthin production. These findings could advance our understanding of the roles of bacteria in Symbiodiniaceae and the coral holobiont, thereby contributing to the development of novel approaches toward coral protection through the use of symbiotic bacteria and their metabolites.IMPORTANCE Occupying less than 1% of the seas, coral reefs are estimated to harbor ∼25% of all marine species. However, the destruction of coral reefs has intensified in the face of global climate changes, such as rising seawater temperatures, which induce the overproduction of reactive oxygen species harmful to corals. Although reef-building corals form complex consortia with bacteria and photosynthetic endosymbiotic algae of the family Symbiodiniaceae, the functional roles of coral-associated bacteria remain largely elusive. By manipulating the Symbiodiniaceae bacterial community, we demonstrated that a bacterium that produces an antioxidant carotenoid could mitigate thermal and light stresses in cultured Symbiodiniaceae isolated from a reef-building coral. Therefore, this study illuminates the unexplored roles of coral-associated bacteria under stressful conditions.}, }
@article {pmid31961929, year = {2020}, author = {Covey, H and Hall, RH and Krafsur, A and Matthews, ML and Shults, PT and Brelsfoard, CL}, title = {Cryptic Wolbachia (Rickettsiales: Rickettsiaceae) Detection and Prevalence in Culicoides (Diptera: Ceratopogonidae) Midge Populations in the United States.}, journal = {Journal of medical entomology}, volume = {57}, number = {4}, pages = {1262-1269}, doi = {10.1093/jme/tjaa003}, pmid = {31961929}, issn = {1938-2928}, mesh = {Animals ; Ceratopogonidae/*microbiology ; Female ; In Situ Hybridization, Fluorescence ; Male ; Real-Time Polymerase Chain Reaction ; United States ; Wolbachia/classification/*isolation &amp; purification ; }, abstract = {Culicoides midges vector numerous veterinary and human pathogens. Many of these diseases lack effective therapeutic treatments or vaccines to limit transmission. The only effective approach to limit disease transmission is vector control. However, current vector control for Culicoides midges is complicated by the biology of many Culicoides species and is not always effective at reducing midge populations and impacting disease transmission. The endosymbiont Wolbachia pipientis Hertig may offer an alternative control approach to limit disease transmission and affect Culicoides populations. Here the detection of Wolbachia infections in nine species of Culicoides midges is reported. Infections were detected at low densities using qPCR. Wolbachia infections were confirmed with the sequencing of a partial region of the 16S gene. Fluorescence in situ hybridization of Culicoides sonorensis Wirth and Jones adults and dissected ovaries confirm the presence of Wolbachia infections in an important vector of Bluetongue and Epizootic hemorrhagic disease viruses. The presence of Wolbachia in Culicoides populations in the United States suggests the need for further investigation of Wolbachia as a strategy to limit transmission of diseases vectored by Culicoides midges.}, }
@article {pmid31958374, year = {2020}, author = {Agany, DDM and Potts, R and Hernandez, JLG and Gnimpieba, EZ and Pietri, JE}, title = {Microbiome Differences Between Human Head and Body Lice Ecotypes Revealed by 16S RRNA Gene Amplicon Sequencing.}, journal = {The Journal of parasitology}, volume = {106}, number = {1}, pages = {14-24}, pmid = {31958374}, issn = {1937-2345}, mesh = {Animals ; Bacteria/*classification/genetics ; DNA/isolation &amp; purification ; *Ecotype ; Female ; Humans ; *Microbiota ; Pediculus/classification/*microbiology/physiology ; Principal Component Analysis ; RNA, Ribosomal, 16S/*chemistry ; Rabbits ; Sequence Analysis, RNA ; }, abstract = {Human head lice and body lice (Pediculus humanus) are neglected ectoparasites. Head lice continue to be prevalent in children worldwide, and insecticide resistance in these insects has complicated their treatment. Meanwhile, body lice, which are most common in the developing world, are resurging among marginalized populations in developed nations. Today, the microbiome is being increasingly recognized as a key mediator of insect physiology. However, the microbial communities that inhabit human lice have remained unknown beyond only a few species of bacteria. Knowledge of the microbiomes of head and body lice could improve our understanding of the observed physiological differences between the 2 ecotypes and potentially inform the development of novel interventions against lice infestations and louse-borne infectious diseases. Toward these goals, here we performed 16S rRNA gene amplicon sequencing to characterize the microbiomes of both head and body lice and identify patterns of interest among these communities. Our data reveal that head and body lice harbor limited but distinct communities of bacteria that include known intracellular endosymbionts ("Candidatus Riesia pediculicola"), extracellular bacteria that may be horizontally acquired from the host environment, and a number of taxa of known or potential public health significance. Notably, in body lice, the relative abundance of vertically transmitted endosymbionts is lower than in head lice, which is a significant driver of greater alpha diversity. Further, several differentially abundant non-endosymbiont taxa and differences in beta diversity were observed between head lice and body lice. These findings support the hypothesis that microbiome differences could contribute to the divergence between human louse ecotypes and underscore the need for future studies to better comprehend the acquisition and physiological roles of human lice microbiomes.}, }
@article {pmid31958110, year = {2020}, author = {Bing, XL and Zhao, DS and Sun, JT and Zhang, KJ and Hong, XY}, title = {Genomic Analysis of Wolbachia from Laodelphax striatellus (Delphacidae, Hemiptera) Reveals Insights into Its "Jekyll and Hyde" Mode of Infection Pattern.}, journal = {Genome biology and evolution}, volume = {12}, number = {2}, pages = {3818-3831}, pmid = {31958110}, issn = {1759-6653}, mesh = {Animals ; Bacterial Proteins/genetics ; Biotin/metabolism ; Genome, Bacterial/genetics ; Genomics/methods ; Hemiptera/*microbiology ; Phenotype ; Phylogeny ; Riboflavin/metabolism ; Wolbachia/*genetics ; }, abstract = {Wolbachia is a widely distributed intracellular bacterial endosymbiont among invertebrates. The wStriCN, the Wolbachia strain that naturally infects an agricultural pest Laodelphax striatellus, has a "Jekyll and Hyde" mode of infection pattern with positive and negative effects: It not only kills many offspring by inducing cytoplasmic incompatibility (CI) but also significantly increases host fecundity. In this study, we assembled the draft genome of wStriCN and compared it with other Wolbachia genomes to look for clues to its Jekyll and Hyde characteristics. The assembled wStriCN draft genome is 1.79 Mb in size, which is the largest Wolbachia genome in supergroup B. Phylogenomic analysis showed that wStriCN is closest to Wolbachia from Asian citrus psyllid Diaphorina citri. These strains formed a monophylogentic clade within supergroup B. Compared with other Wolbachia genomes, wStriCN contains the most diverse insertion sequence families, the largest amount of prophage sequences, and the most ankyrin domain protein coding genes. The wStriCN genome encodes components of multiple secretion systems, including Types I, II, IV, VI, Sec, and Tac. We detected three pairs of homologs for CI factors CifA and CifB. These proteins harbor the catalytic domains responsible for CI phenotypes but are phylogenetically and structurally distinct from all known Cif proteins. The genome retains pathways for synthesizing biotin and riboflavin, which may explain the beneficial roles of wStriCN in its host planthoppers, which feed on nutrient-poor plant sap. Altogether, the genomic sequencing of wStriCN provides insight into understanding the phylogeny and biology of Wolbachia.}, }
@article {pmid31957790, year = {2020}, author = {Jogawat, A and Meena, MK and Kundu, A and Varma, M and Vadassery, J}, title = {Calcium channel CNGC19 mediates basal defense signaling to regulate colonization by Piriformospora indica in Arabidopsis roots.}, journal = {Journal of experimental botany}, volume = {71}, number = {9}, pages = {2752-2768}, pmid = {31957790}, issn = {1460-2431}, mesh = {*Arabidopsis/genetics/metabolism/microbiology ; *Arabidopsis Proteins/genetics/metabolism ; Basidiomycota/*physiology ; *Calcium Channels ; Gene Expression Regulation, Plant ; Plant Roots/metabolism/microbiology ; Symbiosis ; }, abstract = {The activation of calcium signaling is a crucial event for perceiving environmental stress. Colonization by Piriformospora indica, a growth-promoting root endosymbiont, activates cytosolic Ca2+ in Arabidopsis roots. In this study, we examined the role and functional relevance of calcium channels responsible for Ca2+ fluxes. Expression profiling revealed that CYCLIC NUCLEOTIDE GATED CHANNEL 19 (CNGC19) is an early-activated gene, induced by unidentified components in P. indica cell-wall extract. Functional analysis showed that loss-of-function of CNGC19 resulted in growth inhibition by P.indica, due to increased colonization and loss of controlled fungal growth. The cngc19 mutant showed reduced elevation of cytosolic Ca2+ in response to P. indica cell-wall extract in comparison to the wild-type. Microbe-associated molecular pattern-triggered immunity was compromised in the cngc19 lines, as evidenced by unaltered callose deposition, reduced cis-(+)-12-oxo-phytodienoic acid, jasmonate, and jasmonoyl isoleucine levels, and down-regulation of jasmonate and other defense-related genes, which contributed to a shift towards a pathogenic response. Loss-of-function of CNGC19 resulted in an inability to modulate indole glucosinolate content during P. indica colonization. CNGC19-mediated basal immunity was dependent on the AtPep receptor, PEPR. CNGC19 was also crucial for P. indica-mediated suppression of AtPep-induced immunity. Our results thus demonstrate that Arabidopsis CNGC19 is an important Ca2+ channel that maintains a robust innate immunity and is crucial for growth-promotion signaling upon colonization by P. indica.}, }
@article {pmid31955109, year = {2020}, author = {Rocha, RJM and Rodrigues, ACM and Campos, D and Cícero, LH and Costa, APL and Silva, DAM and Oliveira, M and Soares, AMVM and Patrício Silva, AL}, title = {Do microplastics affect the zoanthid Zoanthus sociatus?.}, journal = {The Science of the total environment}, volume = {713}, number = {}, pages = {136659}, doi = {10.1016/j.scitotenv.2020.136659}, pmid = {31955109}, issn = {1879-1026}, mesh = {Animals ; *Anthozoa ; Coral Reefs ; Microplastics ; }, abstract = {Microplastics (1 μm-5 mm), a ubiquitous and persistent marine pollutant, pose a severe threat to coral reefs when recently associated with physiological distress and increased diseases on corals. Studies conducted so far have only reported effects on scleractinian species. Knowledge about its effects on other corals (e.g. Order Zoantharia) remains uncovered, and responses at biochemical levels remain poorly documented. This study aimed to assess the potential effects induced by the presence of microplastics (1 and 10 mg L[-1] low-density polyethylene, LDPE MP, or polyvinyl chloride, PVC MP) in the tropical and subtropical cosmopolitan species Zoanthus sociatus (order Zoantharia. Anthozoa: Hexacorallia), at organism level (survival and behaviour), endosymbionts (photosynthetic efficiency) and the cellular level (oxidative stress, detoxification capacity and energy metabolism). In a short-term exposure (96 h), this species was more sensitive to PVC MP. The presence of this polymer at a concentration of 10 mg L[-1] caused a ten-fold higher adhesion to the coral epidermis, increased photosynthetic efficiency, lipid peroxidation, and antioxidant defences; without, however, inducing energetic costs. Although the observed physiological and biochemical effects did not compromise Z. sociatus survival in the short term, it does not rule out potential long-term (cumulative) effects that could endanger this and other physiologically similar species that underlie coral reefs.}, }
@article {pmid31953633, year = {2020}, author = {Dergousoff, SJ and Anstead, CA and Chilton, NB}, title = {Identification of bacteria in the Rocky Mountain wood tick, Dermacentor andersoni, using single-strand conformation polymorphism (SSCP) and DNA sequencing.}, journal = {Experimental &amp; applied acarology}, volume = {80}, number = {2}, pages = {247-256}, pmid = {31953633}, issn = {1572-9702}, mesh = {Animals ; Canada ; DNA, Bacterial/genetics ; Dermacentor/*microbiology ; *Polymorphism, Single-Stranded Conformational ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification ; Sequence Analysis, DNA ; }, abstract = {PCR-based single-strand conformation polymorphism (SSCP) analyses combined with DNA sequencing of the prokaryotic 16S ribosomal (r) RNA gene encompassing the hypervariable V4 region was used to determine the bacterial composition of Rocky Mountain wood ticks (Dermacentor andersoni) attached to Richardson's ground squirrels (Urocitellus richardsonii) and questing on vegetation in southern Saskatchewan, Canada. The bacteria present in questing adult ticks from Saskatchewan Landing Provincial Park included Rickettsia peacockii, a Francisella-like endosymbiont (FLE) and an Arsenophonus-like endosymbiont. Bacteria in the adult and nymphal ticks attached to U. richardsonii collected from Beechy included R. peacockii, a FLE, and several other genera (e.g., Ralstonia, Sphingobium, Comamonas and Pseudomonas). The bacteria detected in D. andersoni in the present study are consistent with the findings of other studies that have characterized the microbiome of this tick species in the USA using next generation sequencing. This result demonstrates that the SSCP-based approach used in this study is cost- and time-effective for examining bacterial composition in ticks.}, }
@article {pmid31947801, year = {2020}, author = {Lüthi, MN and Vorburger, C and Dennis, AB}, title = {A Novel RNA Virus in the Parasitoid Wasp Lysiphlebus fabarum: Genomic Structure, Prevalence, and Transmission.}, journal = {Viruses}, volume = {12}, number = {1}, pages = {}, pmid = {31947801}, issn = {1999-4915}, support = {PP00P3_146341//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/International ; CRSII3_154396//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/International ; }, mesh = {Amino Acid Sequence ; Animals ; Aphids/parasitology ; Female ; Genetic Variation ; Genome, Viral/*genetics ; Haplotypes ; Insect Viruses/classification/genetics/*physiology ; Male ; Phylogeny ; Positive-Strand RNA Viruses/classification/genetics/*physiology ; Viral Load ; Viral Proteins/genetics ; Wasps/physiology/*virology ; }, abstract = {We report on a novel RNA virus infecting the wasp Lysiphlebus fabarum, a parasitoid of aphids. This virus, tentatively named "Lysiphlebus fabarum virus" (LysV), was discovered in transcriptome sequences of wasps from an experimental evolution study in which the parasitoids were allowed to adapt to aphid hosts (Aphis fabae) with or without resistance-conferring endosymbionts. Based on phylogenetic analyses of the viral RNA-dependent RNA polymerase (RdRp), LysV belongs to the Iflaviridae family in the order of the Picornavirales, with the closest known relatives all being parasitoid wasp-infecting viruses. We developed an endpoint PCR and a more sensitive qPCR assay to screen for LysV in field samples and laboratory lines. These screens verified the occurrence of LysV in wild parasitoids and identified the likely wild-source population for lab infections in Western Switzerland. Three viral haplotypes could be distinguished in wild populations, of which two were found in the laboratory. Both vertical and horizontal transmission of LysV were demonstrated experimentally, and repeated sampling of laboratory populations suggests that the virus can form persistent infections without obvious symptoms in infected wasps.}, }
@article {pmid31945519, year = {2020}, author = {Meenatchi, R and Thinesh, T and Brindangnanam, P and Hassan, S and Kiran, GS and Selvin, J}, title = {Revealing the impact of global mass bleaching on coral microbiome through 16S rRNA gene-based metagenomic analysis.}, journal = {Microbiological research}, volume = {233}, number = {}, pages = {126408}, doi = {10.1016/j.micres.2019.126408}, pmid = {31945519}, issn = {1618-0623}, mesh = {Animals ; Anthozoa/*microbiology/physiology ; Bacteria/*classification ; Coral Reefs ; *Heat-Shock Response ; High-Throughput Nucleotide Sequencing ; India ; *Metagenome ; *Microbiota ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Coral bleaching, a phenomenon by which the expulsion of corals' alveolate endosymbiont (zooxanthellae) occurs when experiencing thermal stress is the major cause for devastation of corals. However, apart from this obligate symbiont of Scleractinian corals, there are different kinds of microbes that exist as stable, transient or sporadic members of the holobiont which reside within various microhabitats in the coral structures. Thus, this study aims to profile the coral bacterial community composition among different coral genera (thermally-sensitive (Acropora digetifera and A. noblis) and thermally resistant (Favites abdita) coral genera analyzed by field monitoring surveys) and also in a particular coral genus (thermally sensitive coral-A. digetifera) at two different sampling times (March 2016 and January 2017). A total of about 608695 paired end reads were obtained through Illumina MiSeq Sequencing platform. The alpha diversity indices (ACE, Chao1 and Shannon) were found to be higher in A. nobilis, followed by A. digetifera and Favites abdita, and the corresponding Simpson values were also found to follow the same trend, indicating that the samples are both rich in species diversity and species evenness. Proteobacteria was found to be the most dominant phylum and Gammaproteobacteria was the predominant class present in all the coral genera studied as also during different sampling time periods. As Vibrionaceae was previously reported to increase its abundance during bleaching stress conditions, bacterial profiling among different coral genera showed the presence of 86 % Vibrionaceae in A. digetifera colonies, and it was 93 % in A. digetifera samples collected during March 2016 whereas, it was found to decrease significantly (7 %) in same tagged colonies collected during January 2017. Thus, profiling of microbiome is of prime importance while studying the holobiont organism like the corals. Stress levels experienced by Palk Bay are even depicted in this microbiome study showing high alpha diversity indices that should alarm reef managers to pay attention to this precious stress tolerant reef community.}, }
@article {pmid31942975, year = {2020}, author = {Zhu, YX and Song, ZR and Huo, SM and Yang, K and Hong, XY}, title = {Variation in the microbiome of the spider mite Tetranychus truncatus with sex, instar and endosymbiont infection.}, journal = {FEMS microbiology ecology}, volume = {96}, number = {2}, pages = {}, doi = {10.1093/femsec/fiaa004}, pmid = {31942975}, issn = {1574-6941}, mesh = {Animals ; Bacteria/genetics ; Female ; Fertility ; Male ; *Microbiota ; RNA, Ribosomal, 16S ; Spiroplasma/genetics ; *Symbiosis ; Tetranychidae/*microbiology ; Wolbachia/genetics ; }, abstract = {Most arthropod-associated bacterial communities play a crucial role in host functional traits, whose structure could be dominated by endosymbionts. The spider mite Tetranychus truncatus is a notorious agricultural pest harboring various endosymbionts, yet the effects of endosymbionts on spider mite microbiota remain largely unknown. Here, using deep sequencing of the 16S rRNA gene, we characterized the microbiota of male and female T. truncatus with different endosymbionts (Wolbachia and Spiroplasma) across different developmental stages. Although the spider mite microbiota composition varied across the different developmental stages, Proteobacteria were the most dominant bacteria harbored in all samples. Positive relationships among related operational taxonomic units dominated the significant coassociation networks among bacteria. Moreover, the spider mites coinfected with Wolbachia and Spiroplasma had a significantly higher daily fecundity and juvenile survival rate than the singly infected or uninfected spider mites. The possible function of spider-mite associated bacteria was discussed. Our results highlight the dynamics of spider mite microbiotas across different life stages, and the potential role of endosymbionts in shaping the microbiota of spider mites and improving host fitness.}, }
@article {pmid31941692, year = {2020}, author = {Larson, MA and Sayood, K and Bartling, AM and Meyer, JR and Starr, C and Baldwin, J and Dempsey, MP}, title = {Differentiation of Francisella tularensis Subspecies and Subtypes.}, journal = {Journal of clinical microbiology}, volume = {58}, number = {4}, pages = {}, pmid = {31941692}, issn = {1098-660X}, mesh = {*Francisella ; *Francisella tularensis/genetics ; Humans ; *Tularemia/diagnosis ; }, abstract = {The highly infectious and zoonotic pathogen Francisella tularensis is the etiologic agent of tularemia, a potentially fatal disease if untreated. Despite the high average nucleotide identity, which is >99.2% for the virulent subspecies and >98% for all four subspecies, including the opportunistic microbe Francisella tularensis subsp. novicida, there are considerable differences in genetic organization. These chromosomal disparities contribute to the substantial differences in virulence observed between the various F. tularensis subspecies and subtypes. The methods currently available to genotype F. tularensis cannot conclusively identify the associated subpopulation without using time-consuming testing or complex scoring matrices. To address this need, we developed both single and multiplex quantitative real-time PCR (qPCR) assays that can accurately detect and identify the hypervirulent F. tularensis subsp. tularensis subtype A.I, the virulent F. tularensis subsp. tularensis subtype A.II, F. tularensis subsp. holarctica (also referred to as type B), and F. tularensis subsp. mediasiatica, as well as opportunistic F. tularensis subsp. novicida from each other and near neighbors, such as Francisella philomiragia, Francisella persica, and Francisella-like endosymbionts found in ticks. These fluorescence-based singleplex and non-matrix scoring multiplex qPCR assays utilize a hydrolysis probe, providing sensitive and specific F. tularensis subspecies and subtype identification in a rapid manner. Furthermore, sequencing of the amplified F. tularensis targets provides clade confirmation and informative strain-specific details. Application of these qPCR- and sequencing-based detection assays will provide an improved capability for molecular typing and clinical diagnostics, as well as facilitate the accurate identification and differentiation of F. tularensis subpopulations during epidemiological investigations of tularemia source outbreaks.}, }
@article {pmid31940381, year = {2020}, author = {Breusing, C and Franke, M and Young, CR}, title = {Intra-host symbiont diversity in eastern Pacific cold seep tubeworms identified by the 16S-V6 region, but undetected by the 16S-V4 region.}, journal = {PloS one}, volume = {15}, number = {1}, pages = {e0227053}, pmid = {31940381}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*classification/genetics/metabolism ; Biodiversity ; Ecosystem ; Electron Transport Complex IV/genetics ; Geologic Sediments ; Pacific Ocean ; Polychaeta/*classification/genetics/metabolism/*microbiology ; RNA, Ribosomal, 16S/analysis ; Symbiosis ; }, abstract = {Vestimentiferan tubeworms are key taxa in deep-sea chemosynthetic habitats worldwide. As adults they obtain their nutrition through their sulfide-oxidizing bacterial endosymbionts, which are acquired from the environment. Although horizontal transmission should favor infections by various symbiotic microbes, the current paradigm holds that every tubeworm harbors only one endosymbiotic 16S rRNA phylotype. Although previous studies based on traditional Sanger sequencing have questioned these findings, population level high-throughput analyses of the symbiont 16S diversity are still missing. To get further insights into the symbiont genetic variation and uncover hitherto hidden diversity we applied state-of-the-art 16S-V4 amplicon sequencing to populations of the co-occurring tubeworm species Lamellibrachia barhami and Escarpia spicata that were collected during E/V Nautilus and R/V Western Flyer cruises to cold seeps in the eastern Pacific Ocean. In agreement with earlier work our sequence data indicated that L. barhami and E. spicata share one monomorphic symbiont phylotype. However, complementary CARD-FISH analyses targeting the 16S-V6 region implied the existence of an additional phylotype in L. barhami. Our results suggest that the V4 region might not be sufficiently variable to investigate diversity in the intra-host symbiont population at least in the analyzed sample set. This is an important finding given that this region has become the standard molecular marker for high-throughput microbiome analyses. Further metagenomic research will be necessary to solve these issues and to uncover symbiont diversity that is hidden below the 16S rRNA level.}, }
@article {pmid31937677, year = {2020}, author = {Perlmutter, JI and Meyers, JE and Bordenstein, SR}, title = {Transgenic Testing Does Not Support a Role for Additional Candidate Genes in Wolbachia Male Killing or Cytoplasmic Incompatibility.}, journal = {mSystems}, volume = {5}, number = {1}, pages = {}, pmid = {31937677}, issn = {2379-5077}, support = {F31 AI143152/AI/NIAID NIH HHS/United States ; P30 DK058404/DK/NIDDK NIH HHS/United States ; R21 AI133522/AI/NIAID NIH HHS/United States ; }, abstract = {Endosymbiotic bacteria in the genus Wolbachia remarkably infect nearly half of all arthropod species. They spread in part because of manipulations of host sexual reproduction that enhance the maternal transmission of the bacteria, including male killing (death of infected males) and unidirectional cytoplasmic incompatibility (CI; death of offspring from infected fathers and uninfected mothers). Recent discoveries identified several genes in prophage WO of Wolbachia (wmk, cifA, and cifB) that fully or partially recapitulate male killing or CI when transgenically expressed in Drosophila melanogaster However, it is not yet fully resolved if other gene candidates contribute to these phenotypes. Here, we transgenically tested 10 additional gene candidates for their involvement in male killing and/or CI. The results show that despite sequence and protein architecture similarities or comparative associations with reproductive parasitism, transgenic expression of the candidates does not recapitulate male killing or CI. Sequence analysis across Wmk and its closest relatives reveals amino acids that may be important to its function. In addition, evidence is presented to propose new hypotheses regarding the relationship between wmk transcript length and its ability to kill a given host, as well as copy number of wmk homologs within a bacterial strain, which may be predictive of host resistance. Together, these analyses continue to build the evidence for identification of wmk, cifA, and cifB as the major genes that have thus far been shown to cause reproductive parasitism in Wolbachia, and the transgenic resources provide a basis for further functional study of phage WO genes.IMPORTANCE Wolbachia are widespread bacterial endosymbionts that manipulate the reproduction of diverse arthropods to spread through a population and can substantially shape host evolution. Recently, reports identified three prophage WO genes (wmk, cifA, and cifB) that transgenically recapitulate many aspects of reproductive manipulation in Drosophila melanogaster Here, we transgenically tested 10 additional gene candidates for CI and/or male killing in flies. The results yield no evidence for the involvement of these gene candidates in reproductive parasitism, bolstering the evidence for identification of the cif and wmk genes as the major factors involved in their phenotypes. In addition, evidence supports new hypotheses for prediction of male-killing phenotypes or lack thereof based on wmk transcript length and copy number. These experiments inform efforts to understand the full basis of reproductive parasitism for basic and applied purposes and lay the foundation for future work on the function of an interesting group of Wolbachia and phage WO genes.}, }
@article {pmid31932140, year = {2020}, author = {Pettifor, BJ and Doonan, J and Denman, S and McDonald, JE}, title = {Survival of Brenneria goodwinii and Gibbsiella quercinecans, associated with acute oak decline, in rainwater and forest soil.}, journal = {Systematic and applied microbiology}, volume = {43}, number = {2}, pages = {126052}, doi = {10.1016/j.syapm.2019.126052}, pmid = {31932140}, issn = {1618-0984}, mesh = {Enterobacteriaceae/growth &amp; development/isolation &amp; purification/*physiology ; *Forests ; Gammaproteobacteria/growth &amp; development/isolation &amp; purification/*physiology ; Microbial Viability ; Plant Diseases/*microbiology ; Quercus/*microbiology ; Rain/*microbiology ; *Soil Microbiology ; Species Specificity ; }, abstract = {Acute oak decline (AOD) affects native UK oak species causing rapid decline and mortality in as little as five years. A major symptom of AOD is black weeping stem lesions associated with bacterial phytopathogens, Brenneria goodwinii and Gibbsiella quercinecans. However, there is limited knowledge on the ecological and environmental reservoirs of these phytopathogens. Rainwater and soils are common reservoirs of plant pathogens in a forest environment; therefore, the aim of this study was to investigate the survival of B. goodwinii and G. quercinecans in vitro when inoculated into rainwater and forest soil using a combination of agar-based colony counts and gyrB gene-targeted quantitative PCR (qPCR). Brenneria goodwinii lost viability on inoculation into soil and rainwater, but was detectable at low abundance in soil for 28 days using qPCR, suggesting a limited ability to persist outside of the host, potentially in a viable but non-culturable (VBNC) state. Conversely, Gibbsiella quercinecans, was re-isolated from rainwater for the entire duration of the experiment (84 days) and was re-isolated from forest soil after 28 days, with qPCR analysis corroborating these trends. These data demonstrate that B. goodwinii is unable to survive in forest soils and rainwater, suggesting that it may be an endosymbiont of oak trees, whereas G. quercinecans remains viable in soil and rainwater biomes, suggesting a broad ecological distribution. These data advance understanding of the potential epidemiology of AOD-associated bacteria and their ecological reservoirs, thus increasing the overall knowledge of the pathology of AOD, which assists the development of future management strategies.}, }
@article {pmid31927646, year = {2020}, author = {Bezerra-Santos, MA and Nogueira, BCF and Yamatogi, RS and Ramos, RAN and Galhardo, JA and Campos, AK}, title = {Ticks, fleas and endosymbionts in the ectoparasite fauna of the black-eared opossum Dipelphis aurita in Brazil.}, journal = {Experimental &amp; applied acarology}, volume = {80}, number = {3}, pages = {329-338}, pmid = {31927646}, issn = {1572-9702}, mesh = {Anaplasmataceae/isolation &amp; purification ; Animals ; Brazil ; Didelphis/*parasitology ; Flea Infestations/*veterinary ; Ixodidae/*microbiology ; Siphonaptera/*microbiology ; Tick Infestations/*veterinary ; Wolbachia/isolation &amp; purification ; }, abstract = {Ticks and fleas are essential vectors of pathogens that affect humans and animals, and among their hosts, synanthropic animals such as the black-eared opossum, Didelphis aurita, play a role in public health due to their ability to move between urban centers and forested areas in Brazil. This study aimed to assess the ectoparasite fauna of D. aurita, as well as the presence of pathogens and endosymbionts in ticks and fleas. Opossums (n = 58) captured in Tomahawk livetraps were examined for ectoparasites, and their blood sampled for further analysis. Additionally, spleen samples were collected in individuals found dead. Samples were PCR screened for Rickettsia spp., Borrelia spp., Anaplasmataceae, and Babesia spp. Two tick species were morphologically identified as Ixodes loricatus 24/58 (41.4%) and Amblyomma sculptum 1/58 (1.7%). For fleas, Ctenocephalides felis was detected in 60.3% (35/58) of the animals, and Xenopsylla cheopis in 5.2% (3/58). PCR analysis detected Anaplasmataceae DNA in 34% (16/47) of pooled samples of C. felis, and in 66.7% (2/3) pooled samples of X. cheopis. Sequence analysis revealed Wolbachia pipientis symbiont in all positive samples. Tick, blood and spleen samples were all negative for the microorganisms assessed. These findings suggest that these arthropods circulate among wildlife and urban environments, which may implicate in their participation in the cycle of zoonotic pathogens among opossums, humans and companion animals.}, }
@article {pmid31922467, year = {2020}, author = {Goodhead, I and Blow, F and Brownridge, P and Hughes, M and Kenny, J and Krishna, R and McLean, L and Pongchaikul, P and Beynon, R and Darby, AC}, title = {Large-scale and significant expression from pseudogenes in Sodalis glossinidius - a facultative bacterial endosymbiont.}, journal = {Microbial genomics}, volume = {6}, number = {1}, pages = {}, pmid = {31922467}, issn = {2057-5858}, support = {/WT_/Wellcome Trust/United Kingdom ; BB/L014777/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BBJ017698/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Enterobacteriaceae/*genetics ; *Genes, Bacterial ; Proteome ; *Pseudogenes ; Sequence Analysis, DNA ; Sequence Analysis, RNA ; Symbiosis ; Transcriptome ; Tsetse Flies/microbiology ; }, abstract = {The majority of bacterial genomes have high coding efficiencies, but there are some genomes of intracellular bacteria that have low gene density. The genome of the endosymbiont Sodalis glossinidius contains almost 50 % pseudogenes containing mutations that putatively silence them at the genomic level. We have applied multiple 'omic' strategies, combining Illumina and Pacific Biosciences Single-Molecule Real-Time DNA sequencing and annotation, stranded RNA sequencing and proteome analysis to better understand the transcriptional and translational landscape of Sodalis pseudogenes, and potential mechanisms for their control. Between 53 and 74 % of the Sodalis transcriptome remains active in cell-free culture. The mean sense transcription from coding domain sequences (CDSs) is four times greater than that from pseudogenes. Comparative genomic analysis of six Illumina-sequenced Sodalis isolates from different host Glossina species shows pseudogenes make up ~40 % of the 2729 genes in the core genome, suggesting that they are stable and/or that Sodalis is a recent introduction across the genus Glossina as a facultative symbiont. These data shed further light on the importance of transcriptional and translational control in deciphering host-microbe interactions. The combination of genomics, transcriptomics and proteomics gives a multidimensional perspective for studying prokaryotic genomes with a view to elucidating evolutionary adaptation to novel environmental niches.}, }
@article {pmid31919396, year = {2020}, author = {Garcia, GA and Hoffmann, AA and Maciel-de-Freitas, R and Villela, DAM}, title = {Aedes aegypti insecticide resistance underlies the success (and failure) of Wolbachia population replacement.}, journal = {Scientific reports}, volume = {10}, number = {1}, pages = {63}, pmid = {31919396}, issn = {2045-2322}, mesh = {Aedes/*microbiology ; Animals ; *Insecticide Resistance/drug effects ; Insecticides/toxicity ; Models, Biological ; Population Dynamics ; Pyrethrins/toxicity ; Symbiosis ; Wolbachia/drug effects/isolation &amp; purification/*physiology ; }, abstract = {Mosquitoes that carry Wolbachia endosymbionts may help control the spread of arboviral diseases, such as dengue, Zika and chikungunya. Wolbachia frequencies systematically increase only when the frequency-dependent advantage due to cytoplasmic incompatibility exceeds frequency-independent costs, which may be intrinsic to the Wolbachia and/or can be associated with the genetic background into which Wolbachia are introduced. Costs depend on field conditions such as the environmental pesticide load. Introduced mosquitoes need adequate protection against insecticides to ensure survival after release. We model how insecticide resistance of transinfected mosquitoes determines the success of local Wolbachia introductions and link our theoretical results to field data. Two Ae. aegypti laboratory strains carrying Wolbachia were released in an isolated district of Rio de Janeiro, Brazil: wMelBr (susceptible to pyrethroids) and wMelRio (resistant to pyrethroids). Our models elucidate why releases of the susceptible strain failed to result in Wolbachia establishment, while releases of the resistant strain led to Wolbachia transforming the native Ae. aegypti population. The results highlight the importance of matching insecticide resistance levels in release stocks to those in the target natural populations during Wolbachia deployment.}, }
@article {pmid31913264, year = {2020}, author = {Xiang, T and Lehnert, E and Jinkerson, RE and Clowez, S and Kim, RG and DeNofrio, JC and Pringle, JR and Grossman, AR}, title = {Symbiont population control by host-symbiont metabolic interaction in Symbiodiniaceae-cnidarian associations.}, journal = {Nature communications}, volume = {11}, number = {1}, pages = {108}, pmid = {31913264}, issn = {2041-1723}, mesh = {Animals ; Carbon/metabolism ; Dinoflagellida/genetics/growth &amp; development/*physiology ; Glutamate Synthase/genetics/metabolism ; Glutamate-Ammonia Ligase/genetics/metabolism ; Nitrogen/metabolism ; Sea Anemones/enzymology/genetics/*metabolism ; *Symbiosis ; }, abstract = {In cnidarian-Symbiodiniaceae symbioses, algal endosymbiont population control within the host is needed to sustain a symbiotic relationship. However, the molecular mechanisms that underlie such population control are unclear. Here we show that a cnidarian host uses nitrogen limitation as a primary mechanism to control endosymbiont populations. Nitrogen acquisition and assimilation transcripts become elevated in symbiotic Breviolum minutum algae as they reach high-densities within the sea anemone host Exaiptasia pallida. These same transcripts increase in free-living algae deprived of nitrogen. Symbiotic algae also have an elevated carbon-to-nitrogen ratio and shift metabolism towards scavenging nitrogen from purines relative to free-living algae. Exaiptasia glutamine synthetase and glutamate synthase transcripts concomitantly increase with the algal endosymbiont population, suggesting an increased ability of the host to assimilate ammonium. These results suggest algal growth and replication in hospite is controlled by access to nitrogen, which becomes limiting for the algae as their population within the host increases.}, }
@article {pmid31912942, year = {2020}, author = {Masson, F and Calderon-Copete, S and Schüpfer, F and Vigneron, A and Rommelaere, S and Garcia-Arraez, MG and Paredes, JC and Lemaitre, B}, title = {Blind killing of both male and female Drosophila embryos by a natural variant of the endosymbiotic bacterium Spiroplasma poulsonii.}, journal = {Cellular microbiology}, volume = {22}, number = {5}, pages = {e13156}, pmid = {31912942}, issn = {1462-5822}, mesh = {Animals ; Bacterial Proteins/genetics ; Drosophila/embryology/*microbiology ; Drosophila melanogaster ; Female ; Gene Expression Regulation, Bacterial ; Gram-Negative Bacterial Infections/*microbiology/*mortality/veterinary ; Male ; Phenotype ; Spiroplasma/*genetics/*metabolism ; Transcriptome ; }, abstract = {Spiroplasma poulsonii is a vertically transmitted endosymbiont of Drosophila melanogaster that causes male-killing, that is the death of infected male embryos during embryogenesis. Here, we report a natural variant of S. poulsonii that is efficiently vertically transmitted yet does not selectively kill males, but kills rather a subset of all embryos regardless of their sex, a phenotype we call 'blind-killing'. We show that the natural plasmid of S. poulsonii has an altered structure: Spaid, the gene coding for the male-killing toxin, is deleted in the blind-killing strain, confirming its function as a male-killing factor. Then we further investigate several hypotheses that could explain the sex-independent toxicity of this new strain on host embryos. As the second non-male-killing variant isolated from a male-killing original population, this new strain raises questions on how male-killing is maintained or lost in fly populations. As a natural knock-out of Spaid, which is unachievable yet by genetic engineering approaches, this variant also represents a valuable tool for further investigations on the male-killing mechanism.}, }
@article {pmid31910734, year = {2020}, author = {Arab, DA and Bourguignon, T and Wang, Z and Ho, SYW and Lo, N}, title = {Evolutionary rates are correlated between cockroach symbionts and mitochondrial genomes.}, journal = {Biology letters}, volume = {16}, number = {1}, pages = {20190702}, pmid = {31910734}, issn = {1744-957X}, mesh = {Animals ; *Cockroaches ; Evolution, Molecular ; Genome, Bacterial ; *Genome, Mitochondrial ; Phylogeny ; Symbiosis ; }, abstract = {Bacterial endosymbionts evolve under strong host-driven selection. Factors influencing host evolution might affect symbionts in similar ways, potentially leading to correlations between the molecular evolutionary rates of hosts and symbionts. Although there is evidence of rate correlations between mitochondrial and nuclear genes, similar investigations of hosts and symbionts are lacking. Here, we demonstrate a correlation in molecular rates between the genomes of an endosymbiont (Blattabacterium cuenoti) and the mitochondrial genomes of their hosts (cockroaches). We used partial genome data for multiple strains of B. cuenoti to compare phylogenetic relationships and evolutionary rates for 55 cockroach/symbiont pairs. The phylogenies inferred for B. cuenoti and the mitochondrial genomes of their hosts were largely congruent, as expected from their identical maternal and cytoplasmic mode of inheritance. We found a correlation between evolutionary rates of the two genomes, based on comparisons of root-to-tip distances and on comparisons of the branch lengths of phylogenetically independent species pairs. Our results underscore the profound effects that long-term symbiosis can have on the biology of each symbiotic partner.}, }
@article {pmid31904510, year = {2020}, author = {Kaczmarek, &#x141; and Roszkowska, M and Poprawa, I and Janelt, K and Kmita, H and Gawlak, M and Fiałkowska, E and Mioduchowska, M}, title = {Integrative description of bisexual Paramacrobiotus experimentalis sp. nov. (Macrobiotidae) from republic of Madagascar (Africa) with microbiome analysis.}, journal = {Molecular phylogenetics and evolution}, volume = {145}, number = {}, pages = {106730}, doi = {10.1016/j.ympev.2019.106730}, pmid = {31904510}, issn = {1095-9513}, mesh = {Animals ; Bacteroides/genetics/isolation &amp; purification ; DNA, Bacterial/chemistry/metabolism ; Electron Transport Complex IV/classification/genetics ; Female ; Madagascar ; Male ; *Microbiota ; Mitochondria/genetics ; Phylogeny ; Proteobacteria/genetics/isolation &amp; purification ; RNA, Ribosomal, 16S/chemistry/genetics ; RNA, Ribosomal, 18S/classification/genetics ; Symbiosis ; Tardigrada/*classification/genetics/microbiology ; }, abstract = {In a moss samples collected on Madagascar two populations of Paramacrobiotus experimentalis sp. nov. were found. Paramacrobiotus experimentalis sp. nov. with the presence of a microplacoid and areolatus type of eggs is similar to Pam. danielae, Pam. garynahi, Pam. hapukuensis, Pam. peteri, Pam. rioplatensis and Pam. savai, but it differs from them by some morphological and morphometric characters of the eggs. The p-distance between two COI haplotypes of Pam. experimentalis sp. nov. was 0.17%. In turn, the ranges of uncorrected genetic p-distances of all Paramacrobiotus species available in GenBank was from 18.27% (for Pam. lachowskae) to 25.26% (for Pam. arduus) with an average distance of 20.67%. We also found that Pam. experimentalis sp. nov. is bisexual. This observation was congruent on three levels: (i) morphological - specimen size dimorphism; (ii) structural (primary sexual characteristics) - females have an unpaired ovary while males have an unpaired testis and (iii) molecular - heterozygous and homozygous strains of the ITS-2 marker. Although symbiotic associations of hosts with bacteria (including endosymbiotic bacteria) are common in nature and these interactions exert various effects on the evolution, biology and reproductive ecology of hosts, there is still very little information on the bacterial community associated with tardigrades. To fill this gap and characterise the bacterial community of Pam. experimentalis sp. nov. populations and microbiome of its microhabitat, high throughput sequencing of the V3-V4 hypervariable regions in the bacterial 16S rRNA gene fragment was performed. The obtained 16S rRNA gene sequences ranged from 92,665 to 131,163. In total, 135 operational taxonomic units (OTUs) were identified across the rarefied dataset. Overall, both Pam. experimentalis sp. nov. populations were dominated by OTUs ascribed to the phylum Proteobacteria (89-92%) and Firmicutes (6-7%). In the case of samples from tardigrades' laboratory habitat, the most abundant bacterial phylum was Proteobacteria (51-90%) and Bacteroides (9-48%). In all compared microbiome profiles, only 16 of 137 OTUs were shared. We found also significant differences in beta diversity between the partly species-specific microbiome of Pam. experimentalis sp. nov. and its culturing environment. Two OTUs belonging to a putative bacterial endosymbiont were identified - Rickettsiales and Polynucleobacter. We also demonstrated that each bacterial community was rich in genes involved in membrane transport, amino acid metabolism, and carbohydrate metabolism.}, }
@article {pmid31900444, year = {2020}, author = {Wall, CB and Kaluhiokalani, M and Popp, BN and Donahue, MJ and Gates, RD}, title = {Divergent symbiont communities determine the physiology and nutrition of a reef coral across a light-availability gradient.}, journal = {The ISME journal}, volume = {14}, number = {4}, pages = {945-958}, pmid = {31900444}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*physiology ; Autotrophic Processes ; Carbon ; *Coral Reefs ; Dinoflagellida ; Heterotrophic Processes ; Photosynthesis ; Seasons ; Species Specificity ; *Sunlight ; Symbiosis/*physiology ; }, abstract = {Reef corals are mixotrophic organisms relying on symbiont-derived photoautotrophy and water column heterotrophy. Coral endosymbionts (Family: Symbiodiniaceae), while typically considered mutualists, display a range of species-specific and environmentally mediated opportunism in their interactions with coral hosts, potentially requiring corals to rely more on heterotrophy to avoid declines in performance. To test the influence of symbiont communities on coral physiology (tissue biomass, symbiont density, photopigmentation) and nutrition (δ[13]C, δ[15]N), we sampled Montipora capitata colonies dominated by a specialist symbiont Cladocopium spp. or a putative opportunist Durusdinium glynnii (hereafter, C- or D-colonies) from Kāne'ohe Bay, Hawai'i, across gradients in photosynthetically active radiation (PAR) during summer and winter. We report for the first time that isotope values of reef corals are influenced by Symbiodiniaceae communities, indicative of different autotrophic capacities among symbiont species. D-colonies had on average 56% higher symbiont densities, but lower photopigments per symbiont cell and consistently lower δ[13]C values in host and symbiont tissues; this pattern in isotope values is consistent with lower symbiont carbon assimilation and translocation to the host. Neither C- nor D-colonies showed signs of greater heterotrophy or nutritional plasticity; instead changes in δ[13]C values were driven by PAR availability and photoacclimation attributes that differed between symbiont communities. Together, these results reveal Symbiodiniaceae functional diversity produces distinct holobionts with different capacities for autotrophic nutrition, and energy tradeoffs from associating with opportunist symbionts are not met with increased heterotrophy.}, }
@article {pmid31900308, year = {2020}, author = {Madhav, M and Parry, R and Morgan, JAT and James, P and Asgari, S}, title = {Wolbachia Endosymbiont of the Horn Fly (Haematobia irritans irritans): a Supergroup A Strain with Multiple Horizontally Acquired Cytoplasmic Incompatibility Genes.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {6}, pages = {}, pmid = {31900308}, issn = {1098-5336}, mesh = {Animals ; Gene Transfer, Horizontal ; *Genes, Bacterial ; Muscidae/*microbiology ; *Symbiosis/genetics ; Wolbachia/genetics/*physiology ; }, abstract = {The horn fly, Haematobia irritansirritans, is a hematophagous parasite of livestock distributed throughout Europe, Africa, Asia, and the Americas. Welfare losses on livestock due to horn fly infestation are estimated to cost between $1 billion and $2.5 billion (U.S. dollars) annually in North America and Brazil. The endosymbiotic bacterium Wolbachia pipientis is a maternally inherited manipulator of reproductive biology in arthropods and naturally infects laboratory colonies of horn flies from Kerrville, TX, and Alberta, Canada, but it has also been identified in wild-caught samples from Canada, the United States, Mexico, and Hungary. Reassembly of PacBio long-read and Illumina genomic DNA libraries from the Kerrville H. i. irritans genome project allowed for a complete and circularized 1.3-Mb Wolbachia genome (wIrr). Annotation of wIrr yielded 1,249 coding genes, 34 tRNAs, 3 rRNAs, and 5 prophage regions. Comparative genomics and whole-genome Bayesian evolutionary analysis of wIrr compared to published Wolbachia genomes suggested that wIrr is most closely related to and diverged from Wolbachia supergroup A strains known to infect Drosophila spp. Whole-genome synteny analyses between wIrr and closely related genomes indicated that wIrr has undergone significant genome rearrangements while maintaining high nucleotide identity. Comparative analysis of the cytoplasmic incompatibility (CI) genes of wIrr suggested two phylogenetically distinct CI loci and acquisition of another cifB homolog from phylogenetically distant supergroup A Wolbachia strains, suggesting horizontal acquisition of these loci. The wIrr genome provides a resource for future examination of the impact Wolbachia may have in both biocontrol and potential insecticide resistance of horn flies.IMPORTANCE Horn flies, Haematobia irritans irritans, are obligate hematophagous parasites of cattle having significant effects on production and animal welfare. Control of horn flies mainly relies on the use of insecticides, but issues with resistance have increased interest in development of alternative means of control. Wolbachia pipientis is an endosymbiont bacterium known to have a range of effects on host reproduction, such as induction of cytoplasmic incompatibility, feminization, male killing, and also impacts vector transmission. These characteristics of Wolbachia have been exploited in biological control approaches for a range of insect pests. Here we report the assembly and annotation of the circular genome of the Wolbachia strain of the Kerrville, TX, horn fly (wIrr). Annotation of wIrr suggests its unique features, including the horizontal acquisition of additional transcriptionally active cytoplasmic incompatibility loci. This study provides the foundation for future studies of Wolbachia-induced biological effects for control of horn flies.}, }
@article {pmid31900233, year = {2020}, author = {Ghafar, A and Cabezas-Cruz, A and Galon, C and Obregon, D and Gasser, RB and Moutailler, S and Jabbar, A}, title = {Bovine ticks harbour a diverse array of microorganisms in Pakistan.}, journal = {Parasites &amp; vectors}, volume = {13}, number = {1}, pages = {1}, pmid = {31900233}, issn = {1756-3305}, mesh = {Animals ; Bacteria/classification/genetics/isolation &amp; purification ; Buffaloes/*parasitology ; Cattle/*parasitology ; Disease Reservoirs/microbiology/parasitology ; Pakistan ; Parasites/classification/genetics/*isolation &amp; purification ; Phylogeny ; Ticks/classification/*microbiology/*parasitology ; }, abstract = {BACKGROUND: Ticks and tick-borne pathogens (TTBP) are a major constraint to livestock production in Pakistan; despite a high prevalence of TTBPs, knowledge on the capacity of Pakistani ticks to carry pathogens and endosymbionts is limited. Furthermore, mixed infections with multiple microorganisms further complicate and limit the detection potential of traditional diagnostic methods. The present study investigated the tick-borne microorganisms in bovine ticks in Pakistan, employing a high-throughput microfluidic real-time PCR based technique.<br><br>METHODS: Ticks were collected from clinically healthy cattle (n&#xa0;=&#xa0;116) and water buffaloes (n&#xa0;=&#xa0;88) from 30 villages across six districts located in five agro-ecological zones (AEZs) of Pakistan from September to November 2017. The microfluidic real-time PCR was used to test the genomic DNA of individual ticks for the presence of 27 bacterial and eight parasitic microorganisms. Phylogenetic methods were used to assess the genetic relationship of DNA sequences determined herein.<br><br>RESULTS: PCR detected DNA of at least one microorganism in each of 221 ticks tested (94.4%, 221/234). DNA-based detection inferred that single pathogens/endosymbionts were the most common (43.4%, 96/221) followed by double (38.9%, 86/221), triple (14.5%, 32/221), quadruple (2.3%, 5/221) and quintuple (0.9%, 2/221) mixed infections. Piroplasms (Babesia/Theileria spp.) were the most prevalent (31.6%, 74/234), followed by Ehrlichia spp. (20%, 47/234) and Anaplasma marginale (7.7%, 18/234). Anaplasma phagocytophilum, A. ovis, A. centrale, Babesia ovis, Borrelia spp., Rickettsia spp., R. massiliae, Bartonella spp. and Hepatozoon spp. were also detected. Endosymbionts such as Francisella-like (91.5%, 214/234) and Coxiella-like (1.3%, 3/234) organisms were also detected in ticks. The highest diversity of microorganisms was detected in Hyalomma anatolicum ticks (test-positive for 14/14 microorganisms), followed by Rhipicephalus microplus (4/14), Hy. hussaini (3/14) and Rh. annulatus (2/14). Ticks collected from cattle carried significantly more frequently piroplasms (41.2%, 54/131; P&#xa0;<&#xa0;0.05) than those from buffaloes (19.4%, 20/103). However, the overall prevalence of microorganisms did not vary significantly among ticks from the two host species as well as across different AEZs.<br><br>CONCLUSIONS: To our knowledge, this is the first study to investigate a wide range of tick-borne microorganisms in bovine ticks using a high-throughput diagnostic method from different AEZs in Pakistan. These findings will aid in establishing the distribution patterns and the control of tick-borne pathogens of bovines in Pakistan.}, }
@article {pmid31879707, year = {2019}, author = {Ngamniyom, A and Sriyapai, T and Sriyapai, P and Panyarachun, B}, title = {Contributions to the knowledge of Pseudolevinseniella (Trematoda: Digenea) and temnocephalans from alien crayfish in natural freshwaters of Thailand.}, journal = {Heliyon}, volume = {5}, number = {12}, pages = {e02990}, pmid = {31879707}, issn = {2405-8440}, abstract = {Redclaw crayfish (Cherax quadricarinatus) is a decapod species originating from Australian freshwater. For more than two decades, these crayfish have been re-distributing to environments in many countries, including Thailand. Moreover, they can carry endosymbionts and/or ectosymbionts into new environments. The aim of this study was to introduce a morphological description of Pseudolevinseniella anenteron as a metacercaria of the endoparasites of redclaw crayfish collected from natural water sources in Thailand. The occurrence of two ectosymbiotic temnocephalans (Diceratocephala boschmai and Temnosewellia sp.) in C. quadricarinatus was also reported. The internal morphology of P. anenteron, D. boschmai and Temnosewellia were described and discussed. The surface ultrastructure of the multidentate spines on the body and the metacercarial cyst wall of P. anenteron was investigated by scanning electron microscopy (SEM). By performing a search of the GenBank nucleotide database of partial sequences of 18S, 28S rDNA and cytochrome c oxidase subunit I (cox1), P. anenteron was found to be related to Maritrema, and Temnosewellia was found to be related to T. fasciata. However, according to the cox1 gene, Temnosewellia was found to be similar to T. minor. These results reveal that redclaw crayfish that inhabit natural freshwaters in Thailand may harbour endoparasites and ecto- and endosymbionts. Furthermore, these findings may be able to monitor invasive or non-invasive species in an ecosystem.}, }
@article {pmid31878033, year = {2019}, author = {Van Etten, JL and Agarkova, IV and Dunigan, DD}, title = {Chloroviruses.}, journal = {Viruses}, volume = {12}, number = {1}, pages = {}, pmid = {31878033}, issn = {1999-4915}, support = {1/CX/CSRD VA/United States ; }, mesh = {Biotechnology ; Chlorella/*virology ; Gene Expression Regulation, Viral ; Genome, Viral ; Genomics/methods ; Life Cycle Stages ; Phycodnaviridae/*physiology/ultrastructure ; Structure-Activity Relationship ; Viral Proteins/chemistry/genetics/metabolism ; *Virus Physiological Phenomena ; Virus Replication ; }, abstract = {Chloroviruses are large dsDNA, plaque-forming viruses that infect certain chlorella-like green algae; the algae are normally mutualistic endosymbionts of protists and metazoans and are often referred to as zoochlorellae. The viruses are ubiquitous in inland aqueous environments throughout the world and occasionally single types reach titers of thousands of plaque-forming units per ml of native water. The viruses are icosahedral in shape with a spike structure located at one of the vertices. They contain an internal membrane that is required for infectivity. The viral genomes are 290 to 370 kb in size, which encode up to 16 tRNAs and 330 to ~415 proteins, including many not previously seen in viruses. Examples include genes encoding DNA restriction and modification enzymes, hyaluronan and chitin biosynthetic enzymes, polyamine biosynthetic enzymes, ion channel and transport proteins, and enzymes involved in the glycan synthesis of the virus major capsid glycoproteins. The proteins encoded by many of these viruses are often the smallest or among the smallest proteins of their class. Consequently, some of the viral proteins are the subject of intensive biochemical and structural investigation.}, }
@article {pmid31875152, year = {2019}, author = {Aivelo, T and Norberg, A and Tschirren, B}, title = {Bacterial microbiota composition of Ixodes ricinus ticks: the role of environmental variation, tick characteristics and microbial interactions.}, journal = {PeerJ}, volume = {7}, number = {}, pages = {e8217}, pmid = {31875152}, issn = {2167-8359}, abstract = {Ecological factors, host characteristics and/or interactions among microbes may all shape the occurrence of microbes and the structure of microbial communities within organisms. In the past, disentangling these factors and determining their relative importance in shaping within-host microbiota communities has been hampered by analytical limitations to account for (dis)similar environmental preferences ('environmental filtering'). Here we used a joint species distribution modelling (JSDM) approach to characterize the bacterial microbiota of one of the most important disease vectors in Europe, the sheep tick Ixodes ricinus, along ecological gradients in the Swiss Alps. Although our study captured extensive environmental variation along elevational clines, the explanatory power of such large-scale ecological factors was comparably weak, suggesting that tick-specific traits and behaviours, microhabitat and -climate experienced by ticks, and interactions among microbes play an important role in shaping tick microbial communities. Indeed, when accounting for shared environmental preferences, evidence for significant patterns of positive or negative co-occurrence among microbes was found, which is indicative of competition or facilitation processes. Signals of facilitation were observed primarily among human pathogens, leading to co-infection within ticks, whereas signals of competition were observed between the tick endosymbiont Spiroplasma and human pathogens. These findings highlight the important role of small-scale ecological variation and microbe-microbe interactions in shaping tick microbial communities and the dynamics of tick-borne disease.}, }
@article {pmid31870969, year = {2020}, author = {Kong, X and Li, Y and Zhang, H}, title = {Adaptation evolution and bioactivity of galectin from the deep sea Vesicomyidae clam Archivesica packardana.}, journal = {Fish &amp; shellfish immunology}, volume = {97}, number = {}, pages = {483-492}, doi = {10.1016/j.fsi.2019.12.064}, pmid = {31870969}, issn = {1095-9947}, mesh = {*Acclimatization ; Agglutination ; Animals ; Bacteria ; Bivalvia/*genetics/physiology ; Cold Temperature ; *Evolution, Molecular ; Fungi ; Galectins/*genetics/*metabolism ; Hydrothermal Vents ; Immunity, Innate ; Oceans and Seas ; Phylogeny ; }, abstract = {Hydrothermal vents and cold seep zones are two special habitats in the deep sea. These habitats are always dark, and have extreme temperatures (low or high), heavy metals and toxic substances (sulfide, methane). Vesicomyidae clams, which maintain endosymbionts in their gills, are common species in these two special zones and are thought to develop an efficacious immune system against unusual habitats. In the present study, a novel galectin (Apgalectin) was identified from the Vesicomyidae clam Archivesica packardana. The phylogenetic tree indicated that Apgalectin had two CRDs and was closely clustered with galectins from invertebrates, especially mollusks. A branch-site model showed that 9 positively selected sites (ω2 = 6.83950) were identified comparing to galectins from the Order Veneroida, implying a different function of Vesicomyidae galectins. A microbe binding assay showed that rApgalectin could bind to gram-positive bacteria, gram-negative bacteria and fungi. A PAMP binding assay indicated that Apgalectin could bind LPS, PGN, β-1,3-glucan, glucan from yeast and Poly I:C in dose-dependent manner. Apgalectin only agglutinated Micrococcus luteus and agglutination could be inhibited by galactose which demonstrated that Apgalectin might be involved in immune defense by recognizing and binding bacteria in a β-galactoside manner. Further experiments showed that Apgalectin might play an indirect effector role in the immune response because of its limited antibacterial spectrum. All analyses validated that Apgalectin from Archivesica packardana plays a variety of functions in immune responses and provided basal information for the immune study of deep-sea mollusks.}, }
@article {pmid31870298, year = {2019}, author = {Asimakis, ED and Doudoumis, V and Hadapad, AB and Hire, RS and Batargias, C and Niu, C and Khan, M and Bourtzis, K and Tsiamis, G}, title = {Detection and characterization of bacterial endosymbionts in Southeast Asian tephritid fruit fly populations.}, journal = {BMC microbiology}, volume = {19}, number = {Suppl 1}, pages = {290}, pmid = {31870298}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Gene Transfer, Horizontal ; Pest Control, Biological ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Symbiosis ; Tephritidae/*microbiology ; }, abstract = {BACKGROUND: Various endosymbiotic bacteria, including Wolbachia of the Alphaproteobacteria, infect a wide range of insects and are capable of inducing reproductive abnormalities to their hosts such as cytoplasmic incompatibility (CI), parthenogenesis, feminization and male-killing. These extended phenotypes can be potentially exploited in enhancing environmentally friendly methods, such as the sterile insect technique (SIT), for controlling natural populations of agricultural pests. The goal of the present study is to investigate the presence of Wolbachia, Spiroplasma, Arsenophonus and Cardinium among Bactrocera, Dacus and Zeugodacus flies of Southeast Asian populations, and to genotype any detected Wolbachia strains.<br><br>RESULTS: A specific 16S rRNA PCR assay was used to investigate the presence of reproductive parasites in natural populations of nine different tephritid species originating from three Asian countries, Bangladesh, China and India. Wolbachia infections were identified in Bactrocera dorsalis, B. correcta, B. scutellaris and B. zonata, with 12.2-42.9% occurrence, Entomoplasmatales in B. dorsalis, B. correcta, B. scutellaris, B. zonata, Zeugodacus cucurbitae and Z. tau (0.8-14.3%) and Cardinium in B. dorsalis and Z. tau (0.9-5.8%), while none of the species tested, harbored infections with Arsenophonus. Infected populations showed a medium (between 10 and 90%) or low (<&#x2009;10%) prevalence, ranging from 3 to 80% for Wolbachia, 2 to 33% for Entomoplasmatales and 5 to 45% for Cardinium. Wolbachia and Entomoplasmatales infections were found both in tropical and subtropical populations, the former mostly in India and the latter in various regions of India and Bangladesh. Cardinium infections were identified in both countries but only in subtropical populations. Phylogenetic analysis revealed the presence of Wolbachia with some strains belonging either to supergroup B or supergroup A. Sequence analysis revealed deletions of variable length and nucleotide variation in three Wolbachia genes. Spiroplasma strains were characterized as citri-chrysopicola-mirum and ixodetis strains while the remaining Entomoplasmatales to the Mycoides-Entomoplasmataceae clade. Cardinium strains were characterized as group A, similar to strains infecting Encarsia pergandiella.<br><br>CONCLUSIONS: Our results indicated that in the Southeast natural populations examined, supergroup A Wolbachia strain infections were the most common, followed by Entomoplasmatales and Cardinium. In terms of diversity, most strains of each bacterial genus detected clustered in a common group. Interestingly, the deletions detected in three Wolbachia genes were either new or similar to those of previously identified pseudogenes that were integrated in the host genome indicating putative horizontal gene transfer events in B. dorsalis, B. correcta and B. zonata.}, }
@article {pmid31870295, year = {2019}, author = {Hadapad, AB and Shettigar, SKG and Hire, RS}, title = {Bacterial communities in the gut of wild and mass-reared Zeugodacus cucurbitae and Bactrocera dorsalis revealed by metagenomic sequencing.}, journal = {BMC microbiology}, volume = {19}, number = {Suppl 1}, pages = {282}, pmid = {31870295}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; Cucurbitaceae/parasitology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Gastrointestinal Microbiome ; High-Throughput Nucleotide Sequencing/*methods ; Male ; Mangifera/parasitology ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, RNA ; Tephritidae/*microbiology ; }, abstract = {BACKGROUND: Insect pests belonging to genus Bactrocera sp. (Diptera: Tephritidae) pose major biotic stress on various fruits and vegetable crops around the world. Zeugodacus and Bactrocera sp. are associated with diverse bacterial communities which play an important role in the fitness of sterile insects. The wild populations of melon fly, Zeugodacus cucurbitae (Coquillett) and Oriental fruit fly, Bactrocera dorsalis (Hendel) were collected from pumpkin and mango fields, respectively. The laboratory populations of Z. cucurbitae and B. dorsalis were mass-reared on bottle gourd and sweet banana, respectively. Bacterial communities present in the gut of wild and mass-reared mature (~ 12 days old) and newly emerged (< 1 h after emergence) male and female adults of Z. cucurbitae and B. dorsalis were assessed. We used Illumina HiSeq next-generation sequencing of 16S rRNA gene to profile the gut bacterial communities of wild and mass-reared mature and newly emerged Z. cucurbitae and B. dorsalis adults.<br><br>RESULTS: We found diverse bacterial composition in the gut of wild and mass-reared Z. cucurbitae (ZC) and B. dorsalis (BD) with varied relative abundance. Few taxonomic groups were common to both the species. The most dominant phyla in all samples of Z. cucurbitae and B. dorsalis adults were Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. The phylum Proteobacteria occurred more in wild Z. cucurbitae (~&#x2009;87.72%) and B. dorsalis (~&#x2009;83.87%) as compared to mass-reared Z. cucurbitae (64.15%) and B. dorsalis (~&#x2009;80.96%). Higher relative abundance of Phylum Firmicutes was observed in mass-reared fruit fly than wild adults. Cyanobacteria/Chloroplast and Actinobacteria were also present with very low relative abundance in both wild as well as mass-reared melon fly and Oriental fruit fly. Enterobacteriaceae (61.21%) was dominant family in the gut of both wild and mass-reared adults. Providencia and Lactococcus were dominant genera with varied relative abundance in wild as well as in mass-reared mature and newly emerged fruit fly adults of both species. Some of the genera like Morganella and Serratia were only detected in mass-reared mature and newly emerged Z. cucurbitae and B. dorsalis adults. Principal Coordinate Analysis (PCoA) showed that fruit fly adult samples were grouped based on species and age of the adults while no grouping was observed on the basis of sex of the adult fruit fly.<br><br>CONCLUSIONS: The gut bacterial communities associated with wild and mass-reared mature and newly emerged adults of Z. cucurbitae and B. dorsalis showed variation that depends on species and age of the insects. Understanding the gut microbiota of wild and mass-reared Z. cucurbitae and B. dorsalis using high throughput technology will help to illustrate microbial diversity and this information could be used to develop efficient mass-rearing protocols for successful implementation of sterile insect technique (SIT).}, }
@article {pmid31870290, year = {2019}, author = {Conte, CA and Segura, DF and Milla, FH and Augustinos, A and Cladera, JL and Bourtzis, K and Lanzavecchia, SB}, title = {Wolbachia infection in Argentinean populations of Anastrepha fraterculus sp1: preliminary evidence of sex ratio distortion by one of two strains.}, journal = {BMC microbiology}, volume = {19}, number = {Suppl 1}, pages = {289}, pmid = {31870290}, issn = {1471-2180}, mesh = {Animals ; Bacterial Outer Membrane Proteins/*genetics ; Female ; Male ; Multilocus Sequence Typing ; Phylogeny ; Sex Ratio ; Sexual Behavior, Animal ; Tephritidae/*microbiology ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: Wolbachia, one of the most abundant taxa of intracellular Alphaproteobacteria, is widespread among arthropods and filarial nematodes. The presence of these maternally inherited bacteria is associated with modifications of host fitness, including a variety of reproductive abnormalities, such as cytoplasmic incompatibility, thelytokous parthenogenesis, host feminization and male-killing. Wolbachia has attracted much interest for its role in biological, ecological and evolutionary processes as well as for its potential use in novel and environmentally-friendly strategies for the control of insect pests and disease vectors including a major agricultural pest, the South American fruit fly, Anastrepha fraterculus Wiedemann (Diptera: Tephritidae).<br><br>RESULTS: We used wsp, 16S rRNA and a multilocus sequence typing (MLST) scheme including gatB, coxA, hcpA, fbpA, and ftsZ genes to detect and characterize the Wolbachia infection in laboratory strains and wild populations of A. fraterculus from Argentina. Wolbachia was found in all A. fraterculus individuals studied. Nucleotide sequences analysis of wsp gene allowed the identification of two Wolbachia nucleotide variants (named wAfraCast1_A and wAfraCast2_A). After the analysis of 76 individuals, a high prevalence of the wAfraCast2_A variant was found both, in laboratory (82%) and wild populations (95%). MLST analysis identified both Wolbachia genetic variants as sequence type 13. Phylogenetic analysis of concatenated MLST datasets clustered wAfraCast1/2_A in the supergroup A. Paired-crossing experiments among single infected laboratory strains showed a phenotype specifically associated to wAfraCast1_A that includes slight detrimental effects on larval survival, a female-biased sex ratio; suggesting the induction of male-killing phenomena, and a decreased proportion of females producing descendants that appears attributable to the lack of sperm in their spermathecae.<br><br>CONCLUSIONS: We detected and characterized at the molecular level two wsp gene sequence variants of Wolbachia both in laboratory and wild populations of A. fraterculus sp.1 from Argentina. Crossing experiments on singly-infected A. fraterculus strains showed evidence of a male killing-like mechanism potentially associated to the wAfraCast1_A - A. fraterculus interactions. Further mating experiments including antibiotic treatments and the analysis of early and late immature stages of descendants will contribute to our understanding of the phenotypes elicited by the Wolbachia variant wAfraCast1_A in A. fraterculus sp.1.}, }
@article {pmid31869759, year = {2020}, author = {Hübner, MP and Gunderson, E and Vogel, I and Bulman, CA and Lim, KC and Koschel, M and Ehrens, A and Frohberger, SJ and Fendler, M and Tricoche, N and Voronin, D and Steven, A and Chi, V and Bakowski, MA and Woods, AK and Petrassi, HM and McNamara, CW and Beerntsen, B and Chappell, L and Sullivan, W and Taylor, MJ and Turner, JD and Hoerauf, A and Lustigman, S and Sakanari, JA}, title = {Short-course quinazoline drug treatments are effective in the Litomosoides sigmodontis and Brugia pahangi jird models.}, journal = {International journal for parasitology. Drugs and drug resistance}, volume = {12}, number = {}, pages = {18-27}, pmid = {31869759}, issn = {2211-3207}, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage/*therapeutic use ; Brugia pahangi/drug effects ; Female ; Filariasis/*drug therapy/microbiology ; Filarioidea/drug effects ; Gerbillinae/microbiology/parasitology ; Microfilariae/drug effects ; Onchocerciasis/*drug therapy ; Quinazolines/administration &amp; dosage/*therapeutic use ; Symbiosis/drug effects ; Wolbachia/*drug effects ; }, abstract = {The quinazolines CBR417 and CBR490 were previously shown to be potent anti-wolbachials that deplete Wolbachia endosymbionts of filarial nematodes and present promising pre-clinical candidates for human filarial diseases such as onchocerciasis. In the present study we tested both candidates in two models of chronic filarial infection, namely the Litomosoides sigmodontis and Brugia pahangi jird model and assessed their long-term effect on Wolbachia depletion, microfilariae counts and filarial embryogenesis 16-18 weeks after treatment initiation (wpt). Once per day (QD) oral treatment with CBR417 (50 mg/kg) for 4 days or twice per day (BID) with CBR490 (25 mg/kg) for 7 days during patent L. sigmodontis infection reduced the Wolbachia load by >99% and completely cleared peripheral microfilaremia from 10-14 wpt. Similarly, 7 days of QD treatments (40 mg/kg) with CBR417 or CBR490 cleared >99% of Wolbachia from B. pahangi and reduced peritoneal microfilariae counts by 93% in the case of CBR417 treatment. Transmission electron microscopy analysis indicated intensive damage to the B. pahangi ovaries following CBR417 treatment and in accordance filarial embryogenesis was inhibited in both models after CBR417 or CBR490 treatment. Suboptimal treatment regimens of CBR417 or CBR490 did not lead to a maintained reduction of the microfilariae and Wolbachia load. In conclusion, CBR417 or CBR490 are pre-clinical candidates for filarial diseases, which achieve long-term clearance of Wolbachia endosymbionts of filarial nematodes, inhibit filarial embryogenesis and clear microfilaremia with treatments as short as 7 days.}, }
@article {pmid31862723, year = {2020}, author = {Weldon, SR and Russell, JA and Oliver, KM}, title = {More Is Not Always Better: Coinfections with Defensive Symbionts Generate Highly Variable Outcomes.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {5}, pages = {}, pmid = {31862723}, issn = {1098-5336}, mesh = {Animals ; Aphids/genetics/*microbiology/parasitology ; Enterobacteriaceae/*physiology ; Environment ; Genotype ; *Symbiosis ; }, abstract = {Animal-associated microbes are highly variable, contributing to a diverse set of symbiont-mediated phenotypes. Given that host and symbiont genotypes, and their interactions, can impact symbiont-based phenotypes across environments, there is potential for extensive variation in fitness outcomes. Pea aphids, Acyrthosiphon pisum, host a diverse assemblage of heritable facultative symbionts (HFS) with characterized roles in host defense. Protective phenotypes have been largely studied as single infections, but pea aphids often carry multiple HFS species, and particular combinations may be enriched or depleted compared to expectations based on chance. Here, we examined the consequences of single infection versus coinfection with two common HFS exhibiting variable enrichment, the antiparasitoid Hamiltonella defensa and the antipathogen Regiella insecticola, across three host genotypes and environments. As expected, single infections with either H. defensa or R. insecticola raised defenses against their respective targets. Single infections with protective H. defensa lowered aphid fitness in the absence of enemy challenge, while R. insecticola was comparatively benign. However, as a coinfection, R. insecticola ameliorated H. defensa infection costs. Coinfected aphids continued to receive antiparasitoid protection from H. defensa, but protection was weakened by R. insecticola in two clones. Notably, H. defensa eliminated survival benefits conferred after pathogen exposure by coinfecting R. insecticola Since pathogen sporulation was suppressed by R. insecticola in coinfected aphids, the poor performance likely stemmed from H. defensa-imposed costs rather than weakened defenses. Our results reveal a complex set of coinfection outcomes which may partially explain natural infection patterns and suggest that symbiont-based phenotypes may not be easily predicted based solely on infection status.IMPORTANCE The hyperdiverse arthropods often harbor maternally transmitted bacteria that protect against natural enemies. In many species, low-diversity communities of heritable symbionts are common, providing opportunities for cooperation and conflict among symbionts, which can impact the defensive services rendered. Using the pea aphid, a model for defensive symbiosis, we show that coinfections with two common defensive symbionts, the antipathogen Regiella and the antiparasite Hamiltonella, produce outcomes that are highly variable compared to single infections, which consistently protect against designated enemies. Compared to single infections, coinfections often reduced defensive services during enemy challenge yet improved aphid fitness in the absence of enemies. Thus, infection with multiple symbionts does not necessarily create generalist aphids with "Swiss army knife" defenses against numerous enemies. Instead, particular combinations of symbionts may be favored for a variety of reasons, including their abilities to lessen the costs of other defensive symbionts when enemies are not present.}, }
@article {pmid31861544, year = {2019}, author = {Sheffer, MM and Uhl, G and Prost, S and Lueders, T and Urich, T and Bengtsson, MM}, title = {Tissue- and Population-Level Microbiome Analysis of the Wasp Spider Argiope bruennichi Identified a Novel Dominant Bacterial Symbiont.}, journal = {Microorganisms}, volume = {8}, number = {1}, pages = {}, pmid = {31861544}, issn = {2076-2607}, abstract = {Many ecological and evolutionary processes in animals depend upon microbial symbioses. In spiders, the role of the microbiome in these processes remains mostly unknown. We compared the microbiome between populations, individuals, and tissue types of a range-expanding spider, using 16S rRNA gene sequencing. Our study is one of the first to go beyond targeting known endosymbionts in spiders and characterizes the total microbiome across different body compartments (leg, prosoma, hemolymph, book lungs, ovaries, silk glands, midgut, and fecal pellets). Overall, the microbiome differed significantly between populations and individuals, but not between tissue types. The microbiome of the wasp spider Argiope bruennichi features a novel dominant bacterial symbiont, which is abundant in every tissue type in spiders from geographically distinct populations and that is also present in offspring. The novel symbiont is affiliated with the Tenericutes, but has low sequence identity (<85%) to all previously named taxa, suggesting that the novel symbiont represents a new bacterial clade. Its presence in offspring implies that it is vertically transmitted. Our results shed light on the processes that shape microbiome differentiation in this species and raise several questions about the implications of the novel dominant bacterial symbiont on the biology and evolution of its host.}, }
@article {pmid31860434, year = {2020}, author = {Dietrich, EA and Kingry, LC and Kugeler, KJ and Levy, C and Yaglom, H and Young, JW and Mead, PS and Petersen, JM}, title = {Francisella opportunistica sp. nov., isolated from human blood and cerebrospinal fluid.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {70}, number = {2}, pages = {1145-1151}, pmid = {31860434}, issn = {1466-5034}, support = {CC999999/ImCDC/Intramural CDC HHS/United States ; }, mesh = {Bacterial Typing Techniques ; Base Composition ; Blood/*microbiology ; Cerebrospinal Fluid/*microbiology ; DNA, Bacterial/genetics ; Francisella/*classification/isolation &amp; purification ; Genes, Bacterial ; Humans ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; United States ; }, abstract = {Two isolates of a Gram-negative, non-spore-forming coccobacillus cultured from the blood and cerebrospinal fluid of immunocompromised patients in the United States were described previously. Biochemical and phylogenetic analyses revealed that they belong to a novel species within the Francisella genus. Here we describe a third isolate of this species, recovered from blood of a febrile patient with renal failure, and formally name the Francisella species. Whole genome comparisons indicated the three isolates display greater than 99.9 % average nucleotide identity (ANI) to each other and are most closely related to the tick endosymbiont F. persica, with only 88.6-88.8 % ANI to the type strain of F. persica. Based on biochemical, metabolic and genomic comparisons, we propose that these three isolates should be recognized as Francisella opportunistica sp. nov, with the type strain of the species, PA05-1188[T], available through the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSM 107100) and the American Type Culture Collection (ATCC BAA-2974).}, }
@article {pmid31848270, year = {2019}, author = {Hinzke, T and Kleiner, M and Breusing, C and Felbeck, H and Häsler, R and Sievert, SM and Schlüter, R and Rosenstiel, P and Reusch, TBH and Schweder, T and Markert, S}, title = {Host-Microbe Interactions in the Chemosynthetic Riftia pachyptila Symbiosis.}, journal = {mBio}, volume = {10}, number = {6}, pages = {}, pmid = {31848270}, issn = {2150-7511}, mesh = {Adaptation, Biological ; Animal Nutritional Physiological Phenomena ; Animals ; Aquatic Organisms ; Energy Metabolism ; Metabolic Networks and Pathways ; Metabolome ; *Microbiota ; Oxidation-Reduction ; Polychaeta/*metabolism/*microbiology/ultrastructure ; Proteome ; Proteomics/methods ; Seawater ; *Symbiosis ; }, abstract = {The deep-sea tubeworm Riftia pachyptila lacks a digestive system but completely relies on bacterial endosymbionts for nutrition. Although the symbiont has been studied in detail on the molecular level, such analyses were unavailable for the animal host, because sequence information was lacking. To identify host-symbiont interaction mechanisms, we therefore sequenced the Riftia transcriptome, which served as a basis for comparative metaproteomic analyses of symbiont-containing versus symbiont-free tissues, both under energy-rich and energy-limited conditions. Our results suggest that metabolic interactions include nutrient allocation from symbiont to host by symbiont digestion and substrate transfer to the symbiont by abundant host proteins. We furthermore propose that Riftia maintains its symbiont by protecting the bacteria from oxidative damage while also exerting symbiont population control. Eukaryote-like symbiont proteins might facilitate intracellular symbiont persistence. Energy limitation apparently leads to reduced symbiont biomass and increased symbiont digestion. Our study provides unprecedented insights into host-microbe interactions that shape this highly efficient symbiosis.IMPORTANCE All animals are associated with microorganisms; hence, host-microbe interactions are of fundamental importance for life on earth. However, we know little about the molecular basis of these interactions. Therefore, we studied the deep-sea Riftia pachyptila symbiosis, a model association in which the tubeworm host is associated with only one phylotype of endosymbiotic bacteria and completely depends on this sulfur-oxidizing symbiont for nutrition. Using a metaproteomics approach, we identified both metabolic interaction processes, such as substrate transfer between the two partners, and interactions that serve to maintain the symbiotic balance, e.g., host efforts to control the symbiont population or symbiont strategies to modulate these host efforts. We suggest that these interactions are essential principles of mutualistic animal-microbe associations.}, }
@article {pmid31847845, year = {2019}, author = {Bigiotti, G and Pastorelli, R and Guidi, R and Belcari, A and Sacchetti, P}, title = {Horizontal transfer and finalization of a reliable detection method for the olive fruit fly endosymbiont, Candidatus Erwinia dacicola.}, journal = {BMC biotechnology}, volume = {19}, number = {Suppl 2}, pages = {93}, pmid = {31847845}, issn = {1472-6750}, mesh = {Animals ; Animals, Laboratory/growth &amp; development/*microbiology ; DNA, Bacterial/genetics ; Erwinia/genetics/*isolation &amp; purification ; Female ; Insect Control ; Larva/growth &amp; development/microbiology ; Male ; Olea/*parasitology ; Sexual Behavior, Animal ; Symbiosis ; Tephritidae/growth &amp; development/microbiology/*physiology ; }, abstract = {BACKGROUND: The olive fly, Bactrocera oleae, is the most important insect pest in olive production, causing economic damage to olive crops worldwide. In addition to extensive research on B. oleae control methods, scientists have devoted much effort in the last century to understanding olive fly endosymbiosis with a bacterium eventually identified as Candidatus Erwinia dacicola. This bacterium plays a relevant role in olive fly fitness. It is vertically transmitted, and it benefits both larvae and adults in wild populations; however, the endosymbiont is not present in lab colonies, probably due to the antibiotics and preservatives required for the preparation of artificial diets. Endosymbiont transfer from wild B. oleae populations to laboratory-reared ones allows olive fly mass-rearing, thus producing more competitive flies for future Sterile Insect Technique (SIT) applications.<br><br>RESULTS: We tested the hypothesis that Ca. E. dacicola might be transmitted from wild, naturally symbiotic adults to laboratory-reared flies. Several trials have been performed with different contamination sources of Ca. E. dacicola, such as ripe olives and gelled water contaminated by wild flies, wax domes containing eggs laid by wild females, cages dirtied by faeces dropped by wild flies and matings between lab and wild adults. PCR-DGGE, performed with the primer set 63F-GC/518R, demonstrated that the transfer of the endosymbiont from wild flies to lab-reared ones occurred only in the case of cohabitation.<br><br>CONCLUSIONS: Cohabitation of symbiotic wild flies and non-symbiotic lab flies allows the transfer of Ca. E. dacicola through adults. Moreover, PCR-DGGE performed with the primer set 63F-GC/518R was shown to be a consistent method for screening Ca. E. dacicola, also showing the potential to distinguish between the two haplotypes (htA and htB). This study represents the first successful attempt at horizontal transfer of Ca. E. dacicola and the first step in acquiring a better understanding of the endosymbiont physiology and its relationship with the olive fly. Our research also represents a starting point for the development of a laboratory symbiotic olive fly colony, improving perspectives for future applications of the Sterile Insect Technique.}, }
@article {pmid31847764, year = {2019}, author = {Wedell, N and Price, TAR and Lindholm, AK}, title = {Gene drive: progress and prospects.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1917}, pages = {20192709}, pmid = {31847764}, issn = {1471-2954}, mesh = {Aedes ; Animals ; Biological Evolution ; Culicidae ; Dengue ; *Disease Vectors ; *Gene Drive Technology ; Mosquito Vectors ; Reproduction ; Wolbachia ; Zika Virus ; Zika Virus Infection ; }, abstract = {Gene drive is a naturally occurring phenomenon in which selfish genetic elements manipulate gametogenesis and reproduction to increase their own transmission to the next generation. Currently, there is great excitement about the potential of harnessing such systems to control major pest and vector populations. If synthetic gene drive systems can be constructed and applied to key species, they may be able to rapidly spread either modifying or eliminating the targeted populations. This approach has been lauded as a revolutionary and efficient mechanism to control insect-borne diseases and crop pests. Driving endosymbionts have already been deployed to combat the transmission of dengue and Zika virus in mosquitoes. However, there are a variety of barriers to successfully implementing gene drive techniques in wild populations. There is a risk that targeted organisms will rapidly evolve an ability to suppress the synthetic drive system, rendering it ineffective. There are also potential risks of synthetic gene drivers invading non-target species or populations. This Special Feature covers the current state of affairs regarding both natural and synthetic gene drive systems with the aim to identify knowledge gaps. By understanding how natural drive systems spread through populations, we may be able to better predict the outcomes of synthetic drive release.}, }
@article {pmid31843766, year = {2019}, author = {Gegner, HM and Rädecker, N and Ochsenkühn, M and Barreto, MM and Ziegler, M and Reichert, J and Schubert, P and Wilke, T and Voolstra, CR}, title = {High levels of floridoside at high salinity link osmoadaptation with bleaching susceptibility in the cnidarian-algal endosymbiosis.}, journal = {Biology open}, volume = {8}, number = {12}, pages = {}, pmid = {31843766}, issn = {2046-6390}, abstract = {Coral reefs are in global decline mainly due to increasing sea surface temperatures triggering coral bleaching. Recently, high salinity has been linked to increased thermotolerance and decreased bleaching in the sea anemone coral model Aiptasia. However, the underlying processes remain elusive. Using two Aiptasia host--endosymbiont pairings, we induced bleaching at different salinities and show reduced reactive oxygen species (ROS) release at high salinities, suggesting a role of osmoadaptation in increased thermotolerance. A subsequent screening of osmolytes revealed that this effect was only observed in algal endosymbionts that produce 2-O-glycerol-α-D-galactopyranoside (floridoside), an osmolyte capable of scavenging ROS. This result argues for a mechanistic link between osmoadaptation and thermotolerance, mediated by ROS-scavenging osmolytes (e.g., floridoside). This sheds new light on the putative mechanisms underlying the remarkable thermotolerance of corals from water bodies with high salinity such as the Red Sea or Persian/Arabian Gulf and holds implications for coral thermotolerance under climate change.This article has an associated First Person interview with the first author of the paper.}, }
@article {pmid31843539, year = {2020}, author = {Li, C and He, M and Yun, Y and Peng, Y}, title = {Co-infection with Wolbachia and Cardinium may promote the synthesis of fat and free amino acids in a small spider, Hylyphantes graminicola.}, journal = {Journal of invertebrate pathology}, volume = {169}, number = {}, pages = {107307}, doi = {10.1016/j.jip.2019.107307}, pmid = {31843539}, issn = {1096-0805}, mesh = {Amino Acids/*metabolism ; Animals ; Bacteroidetes/*physiology ; Fats/*metabolism ; Spiders/*metabolism/microbiology ; Symbiosis ; Transcriptome ; Wolbachia/*physiology ; }, abstract = {Associations between endosymbiotic bacteria and their hosts are widespread in nature and have been demonstrated extensively; however, only a few studies have examined how facultative symbionts affect host nutrition and metabolism. To gain insight into the associations between facultative symbionts and host nutrition and metabolic activity, we detected endosymbiotic infection in a small spider species, Hylyphantes graminicola, and established two infectious strains, i.e., W[-]C[+] (Wolbachia negative, Cardinium positive) and W[+]C[+] (Wolbachia positive, Cardinium positive). We then determined the content of fat and free amino acids in W[-]C[+] and W[+]C[+] spiders, respectively. We also detected the transcriptome of H. graminicola and the expression of genes involved in fat and amino acid metabolism at different host ages. Results showed that fat content in W[+]C[+] spiders was higher than that in W[-]C[+] spiders, and free amino acid content was higher in W[+]C[+] males than W[-]C[+] males, with no difference observed in females. Transcriptome analysis identified 144 (W[-]C[+] vs W[+]C[+]) differentially expressed genes (DEGs). Moreover, the expression of five genes involved in fat and amino acid metabolism were significantly up-regulated in the third, fourth, and fifth instar stages in W[+]C[+] spiders. This study indicated that Wolbachia and Cardinium co-infection had a pivotal effect on fat and amino acid synthesis in hosts. Moreover, our results provide strong evidence explaining the long-term coexistence of hosts and endosymbionts.}, }
@article {pmid31840419, year = {2021}, author = {Xu, TT and Chen, J and Jiang, LY and Qiao, GX}, title = {Diversity of bacteria associated with Hormaphidinae aphids (Hemiptera: Aphididae).}, journal = {Insect science}, volume = {28}, number = {1}, pages = {165-179}, pmid = {31840419}, issn = {1744-7917}, mesh = {*Animal Distribution ; Animals ; Aphids/*microbiology/physiology ; Bacteria/classification/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; High-Throughput Nucleotide Sequencing ; RNA, Bacterial/*analysis ; RNA, Ribosomal, 16S/*analysis ; *Symbiosis ; }, abstract = {Bacteria are ubiquitous inhabitants of animals. Hormaphidinae is a particular aphid group exhibiting very diverse life history traits. However, the microbiota in this group is poorly known. In the present study, using high-throughput sequencing of bacterial 16S ribosomal RNA gene amplicons, we surveyed the bacterial flora in hormaphidine aphids and explored whether the aphid tribe, host plant and geographical distribution are associated with the distribution of secondary symbionts. The most dominant bacteria detected in hormaphidine species are heritable symbionts. As expected, the primary endosymbiont Buchnera aphidicola is the most abundant symbiont across all species and has cospeciated with its host aphids. Six secondary symbionts were detected in Hormaphidinae. Arsenophonus is widespread in Hormaphidinae species, suggesting the possibility of ancient acquisition of this symbiont. Ordination analyses and statistical tests show that the symbiont composition does not seem to relate to any of the aphid tribes, host plants or geographical distributions, which indicate that horizontal transfers might occur for these symbionts in Hormaphidinae. Correlation analysis exhibits negative interference between Buchnera and coexisting secondary symbionts, while the interactions between different secondary symbionts are complicated. These findings display a comprehensive picture of the microbiota in Hormaphidinae and may be helpful in understanding the symbiont diversity within a group of aphids.}, }
@article {pmid31827855, year = {2019}, author = {Schausberger, P and Gotoh, T and Sato, Y}, title = {Spider mite mothers adjust reproduction and sons' alternative reproductive tactics to immigrating alien conspecifics.}, journal = {Royal Society open science}, volume = {6}, number = {11}, pages = {191201}, pmid = {31827855}, issn = {2054-5703}, abstract = {Maternal effects on environmentally induced alternative reproductive tactics (ARTs) are poorly understood but likely to be selected for if mothers can reliably predict offspring environments. We assessed maternal effects in two populations (Y and G) of herbivorous arrhenotokous spider mites Tetranychus urticae, where males conditionally express fighting and sneaking tactics in male-male combat and pre-copulatory guarding behaviour. We hypothesized that resident mothers should adjust their reproduction and sons' ARTs to immigrating alien conspecifics in dependence of alien conspecifics posing a fitness threat or advantage. To induce maternal effects, females were exposed to own or alien socio-environments and mated to own or alien males. Across maternal and sons' reproductive traits, the maternal socio-environment induced stronger effects than the maternal mate, and G-mothers responded more strongly to Y-influence than vice versa. G-socio-environments and Y-mates enhanced maternal egg production in both populations. Maternal exposure to G-socio-environments demoted, yet maternal Y-mates promoted, guarding occurrence and timing by sons. Sneakers guarded earlier than fighters in Y-environments, whereas the opposite happened in G-environments. The endosymbiont Cardinium, present in G, did not exert any classical effect but may have played a role via the shared plant. Our study highlights interpopulation variation in immediate and anticipatory maternal responses to immigrants.}, }
@article {pmid31827121, year = {2019}, author = {Thompson, MC and Feng, H and Wuchty, S and Wilson, ACC}, title = {The green peach aphid gut contains host plant microRNAs identified by comprehensive annotation of Brassica oleracea small RNA data.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {18904}, pmid = {31827121}, issn = {2045-2322}, mesh = {Animals ; Aphids/*physiology ; Brassica/genetics/*metabolism ; Buchnera/genetics ; *Gene Expression Regulation, Plant ; MicroRNAs/genetics/*metabolism ; Symbiosis ; }, abstract = {Like all organisms, aphids, plant sap-sucking insects that house a bacterial endosymbiont called Buchnera, are members of a species interaction network. Ecological interactions across such networks can result in phenotypic change in network members mediated by molecular signals, like microRNAs. Here, we interrogated small RNA data from the aphid, Myzus persicae, to determine the source of reads that did not map to the aphid or Buchnera genomes. Our analysis revealed that the pattern was largely explained by reads that mapped to the host plant, Brassica oleracea, and a facultative symbiont, Regiella. To start elucidating the function of plant small RNA in aphid gut, we annotated 213 unique B. oleracea miRNAs; 32/213 were present in aphid gut as mature and star miRNAs. Next, we predicted targets in the B. oleracea and M. persicae genomes for these 32 plant miRNAs. We found that plant targets were enriched for genes associated with transcription, while the distribution of targets in the aphid genome was similar to the functional distribution of all genes in the aphid genome. We discuss the potential of plant miRNAs to regulate aphid gene expression and the mechanisms involved in processing, export and uptake of plant miRNAs by aphids.}, }
@article {pmid31825546, year = {2020}, author = {Brumin, M and Lebedev, G and Kontsedalov, S and Ghanim, M}, title = {Levels of the endosymbiont Rickettsia in the whitefly Bemisia tabaci are influenced by the expression of vitellogenin.}, journal = {Insect molecular biology}, volume = {29}, number = {2}, pages = {241-255}, doi = {10.1111/imb.12629}, pmid = {31825546}, issn = {1365-2583}, mesh = {Animals ; Gene Expression ; Hemiptera/genetics/*microbiology ; Insect Proteins/*genetics/metabolism ; Rickettsia/*physiology ; *Symbiosis ; Vitellogenins/*genetics/metabolism ; }, abstract = {Bacterial endosymbionts play essential roles in the biology of their arthropod hosts by interacting with internal factors in the host. The whitefly Bemisia tabaci is a worldwide agricultural pest and a supervector for more than 100 plant viruses. Like many other arthropods, Be. tabaci harbours a primary endosymbiont, Porteira aleyrodidarum, and an array of secondary endosymbionts that coexist with Portiera inside bacteriocyte cells. Unlike all of the other secondary symbionts that infect Be. tabaci, Rickettsia has been shown to be an exception by infecting insect organs and not colocalizing with Portiera, and has been shown to significantly impact the insect biology and its interactions with the environment. Little is known about the molecular interactions that underlie insect-symbiont interactions in general, and particularly Be. tabaci-Rickettsia interactions. Here we performed transcriptomic analysis and identified vitellogenin as an important protein that influences the levels of Rickettsia in Be. tabaci. Vitellogenin expression levels were lower in whole insects, but higher in midguts of Rickettsia-infected insects. Immunocapture-PCR assay showed interaction between vitellogenin and Rickettsia, whereas silencing of vitellogenin resulted in nearly complete disappearance of Rickettsia from midguts. Altogether, these results suggest that vitellogenin plays an important role in influencing the levels of Rickettsia in Be. tabaci.}, }
@article {pmid31824764, year = {2019}, author = {Dellagnola, FA and Rodriguez, C and Castro-Vazquez, A and Vega, IA}, title = {A multiple comparative study of putative endosymbionts in three coexisting apple snail species.}, journal = {PeerJ}, volume = {7}, number = {}, pages = {e8125}, pmid = {31824764}, issn = {2167-8359}, abstract = {We here compare morphological and molecular characters of some putative endosymbiotic elements of the digestive gland of three ampullariid species (Pomacea canaliculata, Pomacea scalaris and Asolene platae) which coexist in Lake Regatas (Palermo, Buenos Aires). The putative endosymbionts were reported in these species and were identified as C and K corpuscles. The three species show tubuloacinar glands, each adenomere was constituted mainly by two distinct cell types (columnar and pyramidal). C and K corpuscles together occupied from one-fourth to one-fifth of the tissue area in the three host species, where C corpuscles were round and greenish-brown, were delimited by a distinct wall, stained positively with Alcian Blue and were associated with columnar cells. K corpuscles were oval, dark-brown multilamellar bodies and were associated with pyramidal cells. Under TEM, C corpuscles occurred within vacuoles of columnar cells and contained many electron-dense clumps and irregular membrane stacks and vesicles spread in an electron-lucent matrix. Sometimes a membrane appeared detached from the inner surface of the wall, suggesting the existence of a plasma membrane. In turn, K corpuscles were contained within vacuoles of pyramidal cells and were made of concentric lamellae, which were in turn made of an electron-dense fibrogranular material. No membranes were seen in them. Interspecifically, C corpuscles vary significantly in width and inner contents. K corpuscles were also variable in length and width. However, both C and K corpuscles in the three studied species hybridised with generalised cyanobacterial/chloroplast probes for 16S rRNA. Also, both corpuscle types (isolated from gland homogenates) were sensitive to lysozyme digestion, which indicates that bacterial peptidoglycans are an integral part of their covers. The reported data confirm and extend previous studies on P. canaliculata in which the endosymbiotic nature of C and K corpuscles were first proposed. We further propose that the endosymbiotic corpuscles are related to the Cyanobacteria/chloroplasts clade. Based on the known distribution of these corpuscles in the major clades of Ampullariidae, we hypothesise they may be universally distributed in this family, and that may constitute an interesting model for studying the co-evolution of endosymbionts and their gastropod hosts.}, }
@article {pmid31824759, year = {2019}, author = {Benítez-Malvido, J and Giménez, A and Graciá, E and Rodríguez-Caro, RC and De Ybáñez, RR and Siliceo-Cantero, HH and Traveset, A}, title = {Impact of habitat loss on the diversity and structure of ecological networks between oxyurid nematodes and spur-thighed tortoises (Testudo graeca L.).}, journal = {PeerJ}, volume = {7}, number = {}, pages = {e8076}, pmid = {31824759}, issn = {2167-8359}, abstract = {Habitat loss and fragmentation are recognized as affecting the nature of biotic interactions, although we still know little about such changes for reptilian herbivores and their hindgut nematodes, in which endosymbiont interactions could range from mutualistic to commensal and parasitic. We investigated the potential cost and benefit of endosymbiont interactions between the spur-thighed tortoise (Testudo graeca L.) and adult oxyurid nematodes (Pharyngodonidae order Oxyurida) in scrublands of southern Spain. For this, we assessed the association between richness and abundance of oxyurid species with tortoises' growth rates and body traits (weight and carapace length) across levels of habitat loss (low, intermediate and high). Furthermore, by using an intrapopulation ecological network approach, we evaluated the structure and diversity of tortoise-oxyurid interactions by focusing on oxyurid species infesting individual tortoises with different body traits and growth rates across habitats. Overall, tortoise body traits were not related to oxyurid infestation across habitats. Oxyurid richness and abundance however, showed contrasting relationships with growth rates across levels of habitat loss. At low habitat loss, oxyurid infestation was positively associated with growth rates (suggesting a mutualistic oxyurid-tortoise relationship), but the association became negative at high habitat loss (suggesting a parasitic relationship). Furthermore, no relationship was observed when habitat loss was intermediate (suggesting a commensal relationship). The network analysis showed that the oxyurid community was not randomly assembled but significantly nested, revealing a structured pattern for all levels of habitat loss. The diversity of interactions was lowest at low habitat loss. The intermediate level, however, showed the greatest specialization, which indicates that individuals were infested by fewer oxyurids in this landscape, whereas at high habitat loss individuals were the most generalized hosts. Related to the latter, connectance was greatest at high habitat loss, reflecting a more uniform spread of interactions among oxyurid species. At an individual level, heavier and larger tortoises tended to show a greater number of oxyurid species interactions. We conclude that there is an association between habitat loss and the tortoise-oxyurid interaction. Although we cannot infer causality in their association, we hypothesize that such oxyurids could have negative, neutral and positive consequences for tortoise growth rates. Ecological network analysis can help in the understanding of the nature of such changes in tortoise-oxyurid interactions by showing how generalized or specialized such interactions are under different environmental conditions and how vulnerable endosymbiont interactions might be to further habitat loss.}, }
@article {pmid31822714, year = {2019}, author = {Li, K and Stanojević, M and Stamenković, G and Ilić, B and Paunović, M and Lu, M and Pešić, B and Đurić Maslovara, I and Siljic, M and Cirkovic, V and Zhang, Y}, title = {Insight into diversity of bacteria belonging to the order Rickettsiales in 9 arthropods species collected in Serbia.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {18680}, pmid = {31822714}, issn = {2045-2322}, mesh = {Animals ; *Biodiversity ; Biological Evolution ; DNA, Bacterial/genetics ; *Genetic Variation ; Ixodes/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiales/*classification/isolation &amp; purification ; Seasons ; Serbia ; }, abstract = {Rickettsiales bacteria in arthropods play a significant role in both public health and arthropod ecology. However, the extensive genetic diversity of Rickettsiales endosymbionts of arthropods is still to be discovered. In 2016, 515 arthropods belonging to 9 species of four classes (Insecta, Chilopoda, Diplopoda and Arachnida) were collected in Serbia. The presence and genetic diversity of Rickettsiales bacteria were evaluated by characterizing the 16S rRNA (rrs), citrate synthase (gltA) and heat shock protein (groEL) genes. The presence of various Rickettsiales bacteria was identified in the majority of tested arthropod species. The results revealed co-circulation of five recognized Rickettsiales species including Rickettsia, Ehrlichia and Wolbachia, as well as four tentative novel species, including one tentative novel genus named Neowolbachia. These results suggest the remarkable genetic diversity of Rickettsiales bacteria in certain arthropod species in this region. Furthermore, the high prevalence of spotted fever group Rickettsia in Ixodes ricinus ticks highlights the potential public health risk of human Rickettsia infection.}, }
@article {pmid31822555, year = {2020}, author = {Leybourne, DJ and Valentine, TA and Bos, JIB and Karley, AJ}, title = {A fitness cost resulting from Hamiltonella defensa infection is associated with altered probing and feeding behaviour in Rhopalosiphum padi.}, journal = {The Journal of experimental biology}, volume = {223}, number = {Pt 1}, pages = {}, doi = {10.1242/jeb.207936}, pmid = {31822555}, issn = {1477-9145}, mesh = {Animals ; Aphids/genetics/growth &amp; development/*physiology ; Enterobacteriaceae/*physiology ; Feeding Behavior ; *Genetic Fitness ; Nymph/genetics/growth &amp; development/physiology ; *Symbiosis ; }, abstract = {Many herbivorous arthropods, including aphids, frequently associate with facultative endosymbiotic bacteria, which influence arthropod physiology and fitness. In aphids, endosymbionts can increase resistance against natural enemies, enhance aphid virulence and alter aphid fitness. Here, we used the electrical penetration graph technique to uncover physiological processes at the insect-plant interface affected by endosymbiont infection. We monitored the feeding and probing behaviour of four independent clonal lines of the cereal-feeding aphid Rhopalosiphum padi derived from the same multilocus genotype containing differential infection (+/-) with a common facultative endosymbiont, Hamiltonella defensa Aphid feeding was examined on a partially resistant wild relative of barley known to impair aphid fitness and a susceptible commercial barley cultivar. Compared with uninfected aphids, endosymbiont-infected aphids on both plant species exhibited a twofold increase in the number of plant cell punctures, a 50% reduction in the duration of each cellular puncture and a twofold higher probability of achieving sustained phloem ingestion. Feeding behaviour was also altered by host plant identity: endosymbiont-infected aphids spent less time probing plant tissue, required twice as many probes to reach the phloem and showed a 44% reduction in phloem ingestion when feeding on the wild barley relative compared with the susceptible commercial cultivar. Reduced feeding success could explain the 22% reduction in growth of H. defensa-infected aphids measured on the wild barley relative. This study provides the first demonstration of mechanisms at the aphid-plant interface contributing to physiological effects of endosymbiont infection on aphid fitness, through altered feeding processes on different quality host plants.}, }
@article {pmid31811433, year = {2020}, author = {Sato, N}, title = {Complex origins of chloroplast membranes with photosynthetic machineries: multiple transfers of genes from divergent organisms at different times or a single endosymbiotic event?.}, journal = {Journal of plant research}, volume = {133}, number = {1}, pages = {15-33}, pmid = {31811433}, issn = {1618-0860}, mesh = {Chloroplasts ; *Cyanobacteria ; *Photosynthesis ; Phylogeny ; Symbiosis ; }, abstract = {The paradigm "cyanobacterial origin of chloroplasts" is currently viewed as an established fact. However, we may have to re-consider the origin of chloroplast membranes, because membranes are not replicated by their own. It is the genes for lipid biosynthetic enzymes that are inherited. In the current understandings, these enzymes became encoded by the nuclear genome as a result of endosymbiotic gene transfer from the endosymbiont. However, we previously showed that many enzymes involved in the synthesis of chloroplast peptidoglycan and glycolipids did not originate from cyanobacteria. Here I present results of comprehensive phylogenetic analysis of chloroplast enzymes involved in fatty acid and lipid biosynthesis, as well as additional chloroplast components related to photosynthesis and gene expression. Four types of phylogenetic relationship between chloroplast enzymes (encoded by the chloroplast and nuclear genomes) and cyanobacterial counterparts were found: type 1, chloroplast enzymes diverged from inside of cyanobacterial clade; type 2, chloroplast and cyanobacterial enzymes are sister groups; type 3, chloroplast enzymes originated from homologs of bacteria other than cyanobacteria; type 4, chloroplast enzymes diverged from eukaryotic homologs. Estimation of evolutionary distances suggested that the acquisition times of chloroplast enzymes were diverse, indicating that multiple gene transfers accounted for the chloroplast enzymes analyzed. Based on the results, I try to relax the tight logic of the endosymbiotic origin of chloroplasts involving a single endosymbiotic event by proposing alternative hypotheses. The hypothesis of host-directed chloroplast formation proposes that glycolipid synthesis ability had been acquired by the eukaryotic host before the acquisition of chloroplast ribosomes. Chloroplast membrane system could have been provided by the host, whereas cyanobacteria contributed to the genes for the genetic and photosynthesis systems, at various times, either before or after the formation of chloroplast membranes. The origin(s) of chloroplasts seems to be more complicated than the single event of primary endosymbiosis.}, }
@article {pmid31811209, year = {2019}, author = {Uzuka, A and Kobayashi, Y and Onuma, R and Hirooka, S and Kanesaki, Y and Yoshikawa, H and Fujiwara, T and Miyagishima, SY}, title = {Responses of unicellular predators to cope with the phototoxicity of photosynthetic prey.}, journal = {Nature communications}, volume = {10}, number = {1}, pages = {5606}, pmid = {31811209}, issn = {2041-1723}, mesh = {Amoebozoa/physiology/radiation effects ; Animals ; Bacteria/metabolism ; Bacterial Physiological Phenomena ; Biological Evolution ; Chlorophyll ; Coculture Techniques ; Eukaryota ; Evolution, Molecular ; *Food Chain ; Light/adverse effects ; Naegleria/growth &amp; development/physiology ; Organelles/physiology ; Oxidative Stress ; Phagocytosis/physiology ; Photosynthesis/*physiology ; Predatory Behavior/*physiology/radiation effects ; Protein Domains ; Reactive Oxygen Species ; Symbiosis/*physiology/radiation effects ; Transcriptome ; }, abstract = {Feeding on unicellular photosynthetic organisms by unicellular eukaryotes is the base of the aquatic food chain and evolutionarily led to the establishment of photosynthetic endosymbionts/organelles. Photosynthesis generates reactive oxygen species and damages cells; thus, photosynthetic organisms possess several mechanisms to cope with the stress. Here, we demonstrate that photosynthetic prey also exposes unicellular amoebozoan and excavates predators to photosynthetic oxidative stress. Upon illumination, there is a commonality in transcriptomic changes among evolutionarily distant organisms feeding on photosynthetic prey. One of the genes commonly upregulated is a horizontally transferred homolog of algal and plant genes for chlorophyll degradation/detoxification. In addition, the predators reduce their phagocytic uptake while accelerating digestion of photosynthetic prey upon illumination, reducing the number of photosynthetic cells inside the predator cells, as this also occurs in facultative endosymbiotic associations upon certain stresses. Thus, some mechanisms in predators observed here probably have been necessary for evolution of endosymbiotic associations.}, }
@article {pmid31811033, year = {2020}, author = {Li, TP and Zhou, CY and Zha, SS and Gong, JT and Xi, Z and Hoffmann, AA and Hong, XY}, title = {Stable Establishment of Cardinium spp. in the Brown Planthopper Nilaparvata lugens despite Decreased Host Fitness.}, journal = {Applied and environmental microbiology}, volume = {86}, number = {4}, pages = {}, pmid = {31811033}, issn = {1098-5336}, mesh = {Animals ; Cytophagaceae/*physiology ; Female ; Genetic Fitness ; Hemiptera/growth &amp; development/*microbiology ; Male ; Nymph/growth &amp; development/microbiology ; *Symbiosis ; }, abstract = {The brown planthopper Nilaparvata lugens (Hemiptera) is a major pest of rice crops in Asia. Artificial transinfections of Wolbachia have recently been used for reducing host impacts, but transinfections have not yet been undertaken with another important endosymbiont, Cardinium This endosymbiont can manipulate the reproduction of hosts through phenotypes such as cytoplasmic incompatibility (CI), which is strong in the related white-backed planthopper, Sogatella furcifera (Hemiptera). Here, we stably infected N. lugens with Cardinium from S. furcifera and showed that it exhibits perfect maternal transmission in N. lugens The density of Cardinium varied across developmental stages and tissues of the transinfected host. Cardinium did not induce strong CI in N. lugens, likely due to its low density in testicles. The infection did decrease fecundity and hatching rate in the transinfected host, but a decrease in fecundity was not apparent when transinfected females mated with Wolbachia-infected males. The experiments show the feasibility of transferring Cardinium endosymbionts across hosts, but the deleterious effects of Cardinium on N. lugens limit its potential to spread in wild populations of N. lugens in the absence of strong CI.IMPORTANCE In this study we established a Cardinium-infected N. lugens line that possessed complete maternal transmission. Cardinium had a widespread distribution in tissues of N. lugens, and this infection decreased the fecundity and hatching rate of the host. Our findings emphasize the feasibility of transinfection of Cardinium in insects, which expands the range of endosymbionts that could be manipulated for pest control.}, }
@article {pmid31805300, year = {2020}, author = {Liu, Y and Fan, ZY and An, X and Shi, PQ and Ahmed, MZ and Qiu, BL}, title = {A single-pair method to screen Rickettsia-infected and uninfected whitefly Bemisia tabaci populations.}, journal = {Journal of microbiological methods}, volume = {168}, number = {}, pages = {105797}, doi = {10.1016/j.mimet.2019.105797}, pmid = {31805300}, issn = {1872-8359}, mesh = {Animals ; Female ; Hemiptera/*microbiology/physiology ; Male ; Microbiological Techniques/*methods ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*genetics/physiology ; Symbiosis/*genetics ; }, abstract = {Bacterial endosymbionts such as Rickettsia and Wolbachia play prominent roles in the development and behaviour of their insect hosts, such as whiteflies, aphids, psyllids and mealybugs. Accumulating studies have emphasized the importance of establishing experimental insect populations that are either lacking or bearing certain species of endosymbionts, because they are the basis in which to reveal the biological role of individual symbionts. In this study, using Rickettsia as an example, we explored a "single-pair screening" method to establish Rickettsia infected and uninfected populations of whitefly Bemisia tabaci MEAM1 for further experimental use. The original host population had a relatively low infection rate of Rickettsia (< 35%). When B. tabaci adults newly emerged, unmated males and females were randomly selected, and released into a leaf cage that covered a healthy plant leaf in order to oviposit F1 generation eggs. Following 6 days of oviposition, the parents were recaptured and used for PCR detection. The F1 progeny, for which parents were either Rickettsia positive or negative, were used to produce the F2 generation, and similarly in turn for the F3, F4 and F5 generations respectively; if the infection status of Rickettsia was consistent in the F1 to F5 generations, then the populations can be used as Rickettsia positive or negative lines for further experiments. In addition, our phylogenetic analyses revealed that Rickettsia has high fidelity during the maternal transmission in different generations.}, }
@article {pmid31800204, year = {2020}, author = {Bratovanov, EV and Ishida, K and Heinze, B and Pidot, SJ and Stinear, TP and Hegemann, JD and Marahiel, MA and Hertweck, C}, title = {Genome Mining and Heterologous Expression Reveal Two Distinct Families of Lasso Peptides Highly Conserved in Endofungal Bacteria.}, journal = {ACS chemical biology}, volume = {15}, number = {5}, pages = {1169-1176}, doi = {10.1021/acschembio.9b00805}, pmid = {31800204}, issn = {1554-8937}, mesh = {Biological Products/chemistry ; Burkholderiaceae/*chemistry/*genetics ; Gene Expression Regulation ; Gene Knockout Techniques ; Genome, Bacterial ; Genomics ; Humans ; Multigene Family ; Mutation ; Peptides/*chemistry/*genetics ; Protein Biosynthesis ; Protein Processing, Post-Translational ; Rhizopus/*chemistry/*genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Genome mining identified the fungal-bacterial endosymbiosis Rhizopus microsporus-Mycetohabitans (previously Burkholderia) rhizoxinica as a rich source of novel natural products. However, most of the predicted compounds have remained cryptic. In this study, we employed heterologous expression to isolate and characterize three ribosomally synthesized and post-translationally modified peptides with lariat topology (lasso peptides) from the endosymbiont M. rhizoxinica: burhizin-23, mycetohabin-16, and mycetohabin-15. Through coexpression experiments, it was shown that an orphan gene product results in mature mycetohabin-15, albeit encoded remotely from the core biosynthetic gene cluster. Comparative genomics revealed that mycetohabins are highly conserved among M. rhizoxinica and related endosymbiotic bacteria. Gene knockout and reinfection experiments indicated that the lasso peptides are not crucial for establishing symbiosis; instead, the peptides are exported into the environment during endosymbiosis. This is the first report on lasso peptides from endosymbiotic bacteria.}, }
@article {pmid31796568, year = {2019}, author = {Chung, M and Teigen, LE and Libro, S and Bromley, RE and Olley, D and Kumar, N and Sadzewicz, L and Tallon, LJ and Mahurkar, A and Foster, JM and Michalski, ML and Dunning Hotopp, JC}, title = {Drug Repurposing of Bromodomain Inhibitors as Potential Novel Therapeutic Leads for Lymphatic Filariasis Guided by Multispecies Transcriptomics.}, journal = {mSystems}, volume = {4}, number = {6}, pages = {}, pmid = {31796568}, issn = {2379-5077}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, abstract = {To better understand the transcriptomic interplay of organisms associated with lymphatic filariasis, we conducted multispecies transcriptome sequencing (RNA-Seq) on the filarial nematode Brugia malayi, its Wolbachia endosymbiont wBm, and its laboratory vector Aedes aegypti across the entire B. malayi life cycle. In wBm, transcription of the noncoding 6S RNA suggests that it may be a regulator of bacterial cell growth, as its transcript levels correlate with bacterial replication rates. For A. aegypti, the transcriptional response reflects the stress that B. malayi infection exerts on the mosquito with indicators of increased energy demand. In B. malayi, expression modules associated with adult female samples consistently contained an overrepresentation of genes involved in chromatin remodeling, such as the bromodomain-containing proteins. All bromodomain-containing proteins encoded by B. malayi were observed to be upregulated in the adult female, embryo, and microfilaria life stages, including 2 members of the bromodomain and extraterminal (BET) protein family. The BET inhibitor JQ1(+), originally developed as a cancer therapeutic, caused lethality of adult worms in vitro, suggesting that it may be a potential therapeutic that can be repurposed for treating lymphatic filariasis.IMPORTANCE The current treatment regimen for lymphatic filariasis is mostly microfilaricidal. In an effort to identify new drug candidates for lymphatic filariasis, we conducted a three-way transcriptomics/systems biology study of one of the causative agents of lymphatic filariasis, Brugia malayi, its Wolbachia endosymbiont wBm, and its vector host Aedes aegypti at 16 distinct B. malayi life stages. B. malayi upregulates the expression of bromodomain-containing proteins in the adult female, embryo, and microfilaria stages. In vitro, we find that the existing cancer therapeutic JQ1(+), which is a bromodomain and extraterminal protein inhibitor, has adulticidal activity in B. malayi.}, }
@article {pmid31790921, year = {2020}, author = {Macumber, AL and Blandenier, Q and Todorov, M and Duckert, C and Lara, E and Lahr, DJG and Mitchell, EAD and Roe, HM}, title = {Phylogenetic divergence within the Arcellinida (Amoebozoa) is congruent with test size and metabolism type.}, journal = {European journal of protistology}, volume = {72}, number = {}, pages = {125645}, doi = {10.1016/j.ejop.2019.125645}, pmid = {31790921}, issn = {1618-0429}, mesh = {Amoebozoa/*classification/*cytology/metabolism ; Energy Metabolism ; *Phylogeny ; Protozoan Infections/genetics ; Species Specificity ; }, abstract = {Arcellinida (lobose testate amoebae) are abundant and diverse in many ecosystems, especially in moist to aquatic environments. Molecular phylogeny has shown that overall test morphology (e.g., spherical or elongate) is generally conserved in Arcellinida lineages, but the taxonomic value of other traits (e.g., size, ornamentation, mixotrophy/heterotrophy metabolism type) has not been systematically evaluated. Morphological and physiological traits that correspond to genetic differences likely represent adaptive traits of ecological significance. We combined high-resolution phylogenetics (NAD9-NAD7 genes) and advanced morphometrics to assess the phylogenetic signal of morphological traits of a group of elongate Difflugia species (Arcellinida). The phylogenetic analyses revealed two clades which could be reliably separated by test size and the presence/absence of mixotrophy. Differences in test size may reflect trophic level, with smaller organisms occupying lower trophic levels. In addition to having larger tests, elongate mixotrophic Difflugia are characterised by wide, flat bases and an inflation of the lower two thirds of their test. These morphological traits may provide additional volume for endosymbionts and/or increased surface area to aid light transmission. Our results showcase greater diversity within the elongate Difflugia and highlight morphological traits of ecological and evolutionary significance.}, }
@article {pmid31790790, year = {2020}, author = {Hosseini-Chegeni, A and Kayedi, MH}, title = {Molecular detection of Coxiella (Gammaproteobacteria: Coxiellaceae) in Argas persicus and Alveonasus canestrinii (Acari: Argasidae) from Iran.}, journal = {Microbial pathogenesis}, volume = {139}, number = {}, pages = {103902}, doi = {10.1016/j.micpath.2019.103902}, pmid = {31790790}, issn = {1096-1208}, mesh = {Acari/*microbiology/physiology ; Animals ; Argas/*microbiology/physiology ; Coxiella/classification/*genetics/*isolation &amp; purification/physiology ; DNA Transposable Elements ; DNA, Bacterial/genetics ; Iran ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {BACKGROUND: Coxiella burnetii and non-C. burnetii bacteria or endosymbiotic Coxiella-like were reported in various tick species. We aimed to detect C. burnetii within soft tick species, Argas persicus and Alveonasus canestrinii.<br><br>METHODS: Argasid ticks were collected from different counties of Lorestan province, west of Iran. Partial fragments of 16S rRNA, IS1111 insertion sequence, com1, htpB, and icd genes related to Coxiella genus were sequenced.<br><br>RESULTS: A partial 16S rRNA and com1 gene fragment as well as IS1111 was detected in four Ar. persicus and twelve Al. canestrinii pools. Moreover, partial htpB and icd gene was only detected in one pool of Ar. persicus.<br><br>CONCLUSIONS: Detection of C. burnetii in tick samples was failed due to the occurrence of Coxiella-like endosymbionts and leads to misidentification. Thus, the house-keeping genes should be designated to distinguish C. burnetii within Coxiella-like endosymbionts.}, }
@article {pmid31788212, year = {2019}, author = {McIlroy, SE and Cunning, R and Baker, AC and Coffroth, MA}, title = {Competition and succession among coral endosymbionts.}, journal = {Ecology and evolution}, volume = {9}, number = {22}, pages = {12767-12778}, pmid = {31788212}, issn = {2045-7758}, abstract = {Host species often support a genetically diverse guild of symbionts, the identity and performance of which can determine holobiont fitness under particular environmental conditions. These symbiont communities are structured by a complex set of potential interactions, both positive and negative, between the host and symbionts and among symbionts. In reef-building corals, stable associations with specific symbiont species are common, and we hypothesize that this is partly due to ecological mechanisms, such as succession and competition, which drive patterns of symbiont winnowing in the initial colonization of new generations of coral recruits. We tested this hypothesis using the experimental framework of the de Wit replacement series and found that competitive interactions occurred among symbionts which were characterized by unique ecological strategies. Aposymbiotic octocoral recruits within high- and low-light environments were inoculated with one of three Symbiodiniaceae species as monocultures or with cross-paired mixtures, and we tracked symbiont uptake using quantitative genetic assays. Priority effects, in which early colonizers excluded competitive dominants, were evidenced under low light, but these early opportunistic species were later succeeded by competitive dominants. Under high light, a more consistent competitive hierarchy was established in which competitive dominants outgrew and limited the abundance of others. These findings provide insight into mechanisms of microbial community organization and symbiosis breakdown and recovery. Furthermore, transitions in competitive outcomes across spatial and temporal environmental variation may improve lifetime host fitness.}, }
@article {pmid31786411, year = {2020}, author = {Bastías, DA and Johnson, LJ and Card, SD}, title = {Symbiotic bacteria of plant-associated fungi: friends or foes?.}, journal = {Current opinion in plant biology}, volume = {56}, number = {}, pages = {1-8}, doi = {10.1016/j.pbi.2019.10.010}, pmid = {31786411}, issn = {1879-0356}, mesh = {Bacteria/genetics ; *Fungi ; Genotype ; *Symbiosis ; }, abstract = {Many bacteria form symbiotic associations with plant-associated fungi. The effects of these symbionts on host fitness usually depend on symbiont or host genotypes and environmental conditions. However, bacterial endosymbionts, that is those living within fungal cells, may positively regulate host performance as their survival is often heavily dependent on host fitness. Contrary to this, bacteria that establish ectosymbiotic associations with fungi, that is those located on the hyphal surface or in close vicinity to fungal mycelia, may not have an apparent net effect on fungal performance due to the low level of fitness dependency on their host. Our analysis supports the hypothesis that endosymbiotic bacteria of fungi are beneficial symbionts, and that effects of ectosymbiotic bacteria on fungal performance depends on the bacterial type involved in the interaction (e.g. helper versus pathogen of fungi). Ecological scenarios, where the presence of beneficial bacterial endosymbionts of fungi could be compromised, are also discussed.}, }
@article {pmid31786246, year = {2020}, author = {Hotterbeekx, A and Raimon, S and Abd-Elfarag, G and Carter, JY and Sebit, W and Suliman, A and Siewe Fodjo, JN and De Witte, P and Logora, MY and Colebunders, R and Kumar-Singh, S}, title = {Onchocerca volvulus is not detected in the cerebrospinal fluid of persons with onchocerciasis-associated epilepsy.}, journal = {International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases}, volume = {91}, number = {}, pages = {119-123}, pmid = {31786246}, issn = {1878-3511}, mesh = {Adult ; Animals ; DNA, Helminth/cerebrospinal fluid ; Epilepsy/*parasitology ; Female ; Humans ; Male ; Microfilariae/isolation &amp; purification ; Onchocerca volvulus/genetics/growth &amp; development/*isolation &amp; purification ; Onchocerciasis/cerebrospinal fluid/*complications/parasitology ; Real-Time Polymerase Chain Reaction ; Skin/parasitology ; Zebrafish ; }, abstract = {OBJECTIVES: Epidemiological evidence links onchocerciasis with the development of epilepsy. The aim of this study was to detect Onchocerca volvulus microfilariae or its bacterial endosymbiont, Wolbachia, in the cerebrospinal fluid (CSF) of persons with onchocerciasis-associated epilepsy (OAE).<br><br>METHODS: Thirteen persons with OAE and O. volvulus skin snip densities of >80 microfilariae were recruited in Maridi County (South Sudan) and their CSF obtained. Cytospin centrifuged preparations of CSF were examined by light microscopy for the presence of O. volvulus microfilariae. DNA was extracted from CSF to detect O. volvulus (O-150 repeat) by quantitative real-time PCR, and Wolbachia (FtsZ gene) by standard PCR. To further investigate whether CSF from onchocerciasis-infected participants could induce seizures, 3- and 7-day old zebrafish larvae were injected with the CSF intracardially and intraperitoneally, respectively. For other zebrafish larvae, CSF was added directly to the larval medium.<br><br>RESULTS: No microfilariae, parasite DNA, or Wolbachia DNA were detected in any of the CSF samples by light microscopy or PCR. All zebrafish survived the procedures and none developed seizures.<br><br>CONCLUSIONS: The absence of O. volvulus in the CSF suggests that OAE is likely not caused by direct parasite invasion into the central nervous system, but by another phenomenon triggered by O. volvulus infection.}, }
@article {pmid31780680, year = {2019}, author = {Vivero, RJ and Villegas-Plazas, M and Cadavid-Restrepo, GE and Herrera, CXM and Uribe, SI and Junca, H}, title = {Wild specimens of sand fly phlebotomine Lutzomyia evansi, vector of leishmaniasis, show high abundance of Methylobacterium and natural carriage of Wolbachia and Cardinium types in the midgut microbiome.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {17746}, pmid = {31780680}, issn = {2045-2322}, mesh = {Animals ; Bacteroidetes/genetics/*isolation &amp; purification ; Female ; Gastrointestinal Microbiome ; Humans ; Insect Vectors/*microbiology ; Leishmaniasis/*transmission ; Male ; Methylobacterium/genetics/*isolation &amp; purification ; Psychodidae/*microbiology ; RNA, Ribosomal, 16S/genetics ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Phlebotomine sand flies are remarkable vectors of several etiologic agents (virus, bacterial, trypanosomatid Leishmania), posing a heavy health burden for human populations mainly located at developing countries. Their intestinal microbiota is involved in a wide range of biological and physiological processes, and could exclude or facilitate such transmission of pathogens. In this study, we investigated the Eubacterial microbiome from digestive tracts of Lu. evansi adults structure using 16S rRNA gene sequence amplicon high throughput sequencing (Illumina MiSeq) obtained from digestive tracts of Lu. evansi adults. The samples were collected at two locations with high incidence of the disease in humans: peri-urban and forest ecosystems from the department of Sucre, Colombia. 289,068 quality-filtered reads of V4 region of 16S rRNA gene were obtained and clustered into 1,762 operational taxonomic units (OTUs) with 97% similarity. Regarding eubacterial diversity, 14 bacterial phyla and 2 new candidate phyla were found to be consistently associated with the gut microbiome content. Proteobacteria, Firmicutes, and Bacteroidetes were the most abundant phyla in all the samples and the core microbiome was particularly dominated by Methylobacterium genus. Methylobacterium species, are known to have mutualistic relationships with some plants and are involved in shaping the microbial community in the phyllosphere. As a remarkable feature, OTUs classified as Wolbachia spp. were found abundant on peri-urban ecosystem samples, in adult male (OTUs n = 776) and unfed female (OTUs n = 324). Furthermore, our results provide evidence of OTUs classified as Cardinium endosymbiont in relative abundance, notably higher with respect to Wolbachia. The variation in insect gut microbiota may be determined by the environment as also for the type of feeding. Our findings increase the richness of the microbiota associated with Lu. evansi. In this study, OTUs of Methylobacterium found in Lu. evansi was higher in engorged females, suggesting that there are interactions between microbes from plant sources, blood nutrients and the parasites they transmit during the blood intake.}, }
@article {pmid31775631, year = {2019}, author = {Stouthamer, CM and Kelly, SE and Mann, E and Schmitz-Esser, S and Hunter, MS}, title = {Development of a multi-locus sequence typing system helps reveal the evolution of Cardinium hertigii, a reproductive manipulator symbiont of insects.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {266}, pmid = {31775631}, issn = {1471-2180}, mesh = {Animals ; Bacterial Typing Techniques/methods ; Bacteroidetes/*classification ; DNA, Ribosomal/genetics ; *Evolution, Molecular ; Insecta/*microbiology/physiology ; Multilocus Sequence Typing/*methods ; Phenotype ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Reproduction ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: Cardinium is an intracellular bacterial symbiont in the phylum Bacteroidetes that is found in many different species of arthropods and some nematodes. This symbiont is known to be able to induce three reproductive manipulation phenotypes, including cytoplasmic incompatibility. Placing individual strains of Cardinium within a larger evolutionary context has been challenging because only two, relatively slowly evolving genes, 16S rRNA gene and Gyrase B, have been used to generate phylogenetic trees, and consequently, the relationship of different strains has been elucidated in only its roughest form.<br><br>RESULTS: We developed a Multi Locus Sequence Typing (MLST) system that provides researchers with three new genes in addition to Gyrase B for inferring phylogenies and delineating Cardinium strains. From our Cardinium phylogeny, we confirmed the presence of a new group D, a Cardinium clade that resides in the arachnid order harvestmen (Opiliones). Many Cardinium clades appear to display a high degree of host affinity, while some show evidence of host shifts to phylogenetically distant hosts, likely associated with ecological opportunity. Like the unrelated reproductive manipulator Wolbachia, the Cardinium phylogeny also shows no clear phylogenetic signal associated with particular reproductive manipulations.<br><br>CONCLUSIONS: The Cardinium phylogeny shows evidence of diversification within particular host lineages, and also of host shifts among trophic levels within parasitoid-host communities. Like Wolbachia, the relatedness of Cardinium strains does not necessarily predict their reproductive phenotypes. Lastly, the genetic tools proposed in this study may help future authors to characterize new strains and add to our understanding of Cardinium evolution.}, }
@article {pmid31772223, year = {2019}, author = {Kamm, K and Osigus, HJ and Stadler, PF and DeSalle, R and Schierwater, B}, title = {Genome analyses of a placozoan rickettsial endosymbiont show a combination of mutualistic and parasitic traits.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {17561}, pmid = {31772223}, issn = {2045-2322}, mesh = {Amino Acids/biosynthesis ; Animals ; Evolution, Molecular ; Genome/genetics ; Genome, Bacterial/genetics ; Metabolic Networks and Pathways/genetics ; Phylogeny ; Placozoa/*genetics/microbiology/physiology ; Rickettsia/*genetics/physiology ; Symbiosis/*genetics ; }, abstract = {Symbiotic relationships between eukaryotic hosts and bacteria range from parasitism to mutualism and may deeply influence both partners' fitness. The presence of intracellular bacteria in the metazoan phylum Placozoa has been reported several times, but without any knowledge about the nature of this relationship and possible implications for the placozoan holobiont. This information may be of crucial significance since little is known about placozoan ecology and how different species adapt to different environmental conditions, despite being almost invariable at the morphological level. We here report on the novel genome of the rickettsial endosymbiont of Trichoplax sp. H2 (strain "Panama"). The combination of eliminated and retained metabolic pathways of the bacterium indicates a potential for a mutualistic as well as for a parasitic relationship, whose outcome could depend on the environmental context. In particular we show that the endosymbiont is dependent on the host for growth and reproduction and that the latter could benefit from a supply with essential amino acids and important cofactors. These findings call for further studies to clarify the actual benefit for the placozoan host and to investigate a possible role of the endosymbiont for ecological separation between placozoan species.}, }
@article {pmid31763192, year = {2019}, author = {Lucchetti, C and Genchi, M and Venco, L and Bazzocchi, C and Kramer, LH and Vismarra, A}, title = {Optimized protocol for DNA/RNA co-extraction from adults of Dirofilaria immitis.}, journal = {MethodsX}, volume = {6}, number = {}, pages = {2601-2605}, pmid = {31763192}, issn = {2215-0161}, abstract = {Dirofilaria immitis, the etiologic agent of canine heartworm disease, like several other filarial nematodes, harbors the bacterial endosymbiont Wolbachia. To investigate metabolic and functional pathways of D. immitis and Wolbachia individually, along with their interactions, the use of both transcriptomic and genome analysis has becoming increasingly popular. Although several commercial kits are available for the single extraction of either DNA or RNA, no specific protocol has been described for simultaneous extraction of DNA and RNA from such a large organism like an adult D. immitis, where female worms generally reach ∼25 cm in length. More importantly, adult worms of D. immitis can only be obtained either through necropsy of experimentally infected dogs or by minimally-invasive surgical heartworm removal of naturally infected dogs. This makes each individual worm sample extremely important. Thus, in the context of a project aimed at the evaluation of both gene expression analysis and Wolbachia population assessment following different treatments, an optimized protocol for co-extraction of DNA and RNA from a single sample of adult D. immitis has been developed. •An optimized method for DNA/RNA co-extraction from large size nematodes using TRIzol® reagent.•Allows maximum exploitation of unique samples as adults of D. immitis.}, }
@article {pmid31761702, year = {2019}, author = {Nazni, WA and Hoffmann, AA and NoorAfizah, A and Cheong, YL and Mancini, MV and Golding, N and Kamarul, GMR and Arif, MAK and Thohir, H and NurSyamimi, H and ZatilAqmar, MZ and NurRuqqayah, M and NorSyazwani, A and Faiz, A and Irfan, FMN and Rubaaini, S and Nuradila, N and Nizam, NMN and Irwan, SM and Endersby-Harshman, NM and White, VL and Ant, TH and Herd, CS and Hasnor, AH and AbuBakar, R and Hapsah, DM and Khadijah, K and Kamilan, D and Lee, SC and Paid, YM and Fadzilah, K and Topek, O and Gill, BS and Lee, HL and Sinkins, SP}, title = {Establishment of Wolbachia Strain wAlbB in Malaysian Populations of Aedes aegypti for Dengue Control.}, journal = {Current biology : CB}, volume = {29}, number = {24}, pages = {4241-4248.e5}, pmid = {31761702}, issn = {1879-0445}, support = {202888/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; 202888/WT_/Wellcome Trust/United Kingdom ; 108508/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/genetics/metabolism/*microbiology ; Animals ; Dengue/*prevention &amp; control ; Dengue Virus/metabolism/pathogenicity ; Female ; Humans ; Insect Vectors ; Malaysia ; Male ; Mosquito Vectors ; Pest Control, Biological/*methods ; Wolbachia/genetics/*metabolism ; }, abstract = {Dengue has enormous health impacts globally. A novel approach to decrease dengue incidence involves the introduction of Wolbachia endosymbionts that block dengue virus transmission into populations of the primary vector mosquito, Aedes aegypti. The wMel Wolbachia strain has previously been trialed in open releases of Ae. aegypti; however, the wAlbB strain has been shown to maintain higher density than wMel at high larval rearing temperatures. Releases of Ae. aegypti mosquitoes carrying wAlbB were carried out in 6 diverse sites in greater Kuala Lumpur, Malaysia, with high endemic dengue transmission. The strain was successfully established and maintained at very high population frequency at some sites or persisted with additional releases following fluctuations at other sites. Based on passive case monitoring, reduced human dengue incidence was observed in the release sites when compared to control sites. The wAlbB strain of Wolbachia provides a promising option as a tool for dengue control, particularly in very hot climates.}, }
@article {pmid31760169, year = {2019}, author = {Brunoro, GVF and Menna-Barreto, RFS and Garcia-Gomes, AS and Boucinha, C and Lima, DB and Carvalho, PC and Teixeira-Ferreira, A and Trugilho, MRO and Perales, J and Schwämmle, V and Catanho, M and de Vasconcelos, ATR and Motta, MCM and d'Avila-Levy, CM and Valente, RH}, title = {Quantitative Proteomic Map of the Trypanosomatid Strigomonas culicis: The Biological Contribution of its Endosymbiotic Bacterium.}, journal = {Protist}, volume = {170}, number = {6}, pages = {125698}, doi = {10.1016/j.protis.2019.125698}, pmid = {31760169}, issn = {1618-0941}, mesh = {*Bacterial Physiological Phenomena ; Proteome/*genetics ; Symbiosis/*physiology ; Trypanosomatina/genetics/*microbiology ; }, abstract = {Strigomonas culicis is a kinetoplastid parasite of insects that maintains a mutualistic association with an intracellular symbiotic bacterium, which is highly integrated into the protist metabolism: it furnishes essential compounds and divides in synchrony with the eukaryotic nucleus. The protist, conversely, can be cured of the endosymbiont, producing an aposymbiotic cell line, which presents a diminished ability to colonize the insect host. This obligatory association can represent an intermediate step of the evolution towards the formation of an organelle, therefore representing an interesting model to understand the symbiogenesis theory. Here, we used shotgun proteomics to compare the S. culicis endosymbiont-containing and aposymbiotic strains, revealing a total of 11,305 peptides, and up to 2,213 proteins (2,029 and 1,452 for wild type and aposymbiotic, respectively). Gene ontology associated to comparative analysis between both strains revealed that the biological processes most affected by the elimination of the symbiont were the amino acid synthesis, as well as protein synthesis and folding. This large-scale comparison of the protein expression in S. culicis marks a step forward in the comprehension of the role of endosymbiotic bacteria in monoxenous trypanosomatid biology, particularly because trypanosomatids expression is mostly post-transcriptionally regulated.}, }
@article {pmid31760093, year = {2020}, author = {Bombaça, ACS and Brunoro, GVF and Dias-Lopes, G and Ennes-Vidal, V and Carvalho, PC and Perales, J and d'Avila-Levy, CM and Valente, RH and Menna-Barreto, RFS}, title = {Glycolytic profile shift and antioxidant triggering in symbiont-free and H2O2-resistant Strigomonas culicis.}, journal = {Free radical biology &amp; medicine}, volume = {146}, number = {}, pages = {392-401}, doi = {10.1016/j.freeradbiomed.2019.11.025}, pmid = {31760093}, issn = {1873-4596}, mesh = {Animals ; *Antioxidants ; Glycolysis ; Humans ; Hydrogen Peroxide ; Symbiosis ; *Trypanosomatina ; }, abstract = {During their life cycle, trypanosomatids are exposed to stress conditions and adapt their energy and antioxidant metabolism to colonize their hosts. Strigomonas culicis is a monoxenous protist found in invertebrates with an endosymbiotic bacterium that completes essential biosynthetic pathways for the trypanosomatid. Our research group previously generated a wild-type H2O2-resistant (WTR) strain that showed improved mitochondrial metabolism and antioxidant defenses, which led to higher rates of Aedes aegypti infection. Here, we assess the biological contribution of the S. culicis endosymbiont and reactive oxygen species (ROS) resistance to oxidative and energy metabolism processes. Using high-throughput proteomics, several proteins involved in glycolysis and gluconeogenesis, the pentose phosphate pathway and glutathione metabolism were identified. The results suggest that ROS resistance decreases glucose consumption and indicate that the metabolic products from gluconeogenesis are key to supplying the protist with high-energy and reducing intermediates. Our hypothesis was confirmed by biochemical assays showing opposite profiles for glucose uptake and hexokinase and pyruvate kinase activity levels in the WTR and aposymbiotic strains, while the enzyme glucose-6P 1-dehydrogenase was more active in both strains. Regarding the antioxidant system, ascorbate peroxidase has an important role in H2O2 resistance and may be responsible for the high infection rates previously described for A. aegypti. In conclusion, our data indicate that the energy-related and antioxidant metabolic processes of S. culicis are modulated in response to oxidative stress conditions, providing new perspectives on the biology of the trypanosomatid-insect interaction as well as on the possible impact of resistant parasites in accidental human infection.}, }
@article {pmid31758847, year = {2020}, author = {Missbah El Idrissi, M and Lamin, H and ElFaik, S and Tortosa, G and Peix, A and Bedmar, EJ and Abdelmoumen, H}, title = {Microvirga sp. symbiovar mediterranense nodulates Lupinus cosentinii grown wild in Morocco.}, journal = {Journal of applied microbiology}, volume = {128}, number = {4}, pages = {1109-1118}, doi = {10.1111/jam.14526}, pmid = {31758847}, issn = {1365-2672}, mesh = {DNA, Bacterial/genetics ; Genes, Essential/genetics ; Lupinus/classification/*microbiology ; Methylobacteriaceae/classification/genetics/isolation &amp; purification/*physiology ; Morocco ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Root Nodules, Plant/microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {AIM: To analyse the diversity of nodule-forming bacteria isolated from Lupinus cosentinii naturally grown in the Maamora cork oak forest (Rabat, Morocco).<br><br>METHODS AND RESULTS: Of the 31 bacterial strains, four were selected based on their REP-PCR fingerprinting that were studied by sequencing and phylogenetic analysis of their 16S rRNA, gyrB, dnaK, recA and rpoB housekeeping genes as well as the nodC symbiotic gene. The nearly complete 16S rRNA gene sequence of the four representative strains showed that they are related to Tunisian strains of genus Microvirga isolated from L. micranthus with nucleotide identity values ranging from 98&#xb7;67 to 97&#xb7;13%. The single and concatenated sequences of the 16S rRNA, gyrB, dnaK, recA and rpoB housekeeping genes indicated that the L. cosentinii-isolated strains had 99&#xb7;2-99&#xb7;9% similarities with the Tunisian L. micranthus microsymbionts. The nodC gene phylogeny revealed that the Moroccan strains clustered in the newly described mediterranense symbiovar, and nodulation tests showed that they nodulated not only L. cosentinii but also L. angustifolius, L. luteus and L. albus.<br><br>CONCLUSIONS: To the best of our knowledge, this is the first report concerning the isolation, molecular identification and phylogenetic diversity of L. cosentinii nodule-forming endosymbionts and of their description as members of the Microvirga genus.<br><br>In this work, we show that Microvirga sp. can be isolated from root nodules of wild-grown L. cosentinii in Northeast Africa, that selected strains also nodulate L. angustifolius, L. luteus and L. albus, and that they belong to symbiovar mediterranense. In addition, our data support that the ability of Microvirga to nodulate lupines could be related to the soil pH, its geographical distribution being more widespread than expected.}, }
@article {pmid31758593, year = {2020}, author = {Cabello-Vílchez, AM and Chura-Araujo, MA and Anicama Lima, WE and Vela, C and Asencio, AY and García, H and Del Carmen Garaycochea, M and Náquira, C and Rojas, E and Martínez, DY}, title = {Fatal granulomatous amoebic encephalitis due to free-living amoebae in two boys in two different hospitals in Lima, Perú.}, journal = {Neuropathology : official journal of the Japanese Society of Neuropathology}, volume = {40}, number = {2}, pages = {180-184}, doi = {10.1111/neup.12617}, pmid = {31758593}, issn = {1440-1789}, mesh = {Adolescent ; Amebiasis/*diagnosis/pathology ; Fatal Outcome ; Granuloma/etiology ; Humans ; Infectious Encephalitis/*diagnosis/*etiology/pathology ; Male ; Peru ; }, abstract = {Granulomatous amoebic encephalitis caused by free-living amoebae is a rare condition that is difficult to diagnose and hard to treat, generally being fatal. Anti-amoebic treatment is often delayed because clinical signs and symptoms may hide the probable causing agent misleading the appropriate diagnostic test. There are four genera of free-living amoeba associated with human infection, Naegleria, Acanthamoeba sp., Balamuthia and Sappinia. Two boys were admitted with diagnosis of acute encephalitis. The history of having been in contact with swimming pools and rivers, supports the suspicion of an infection due to free-living amoebae. In both cases a brain biopsy was done, the histology confirmed granulomatous amoebic encephalitis with the presence of amoebic trophozoites.}, }
@article {pmid31758008, year = {2019}, author = {Lawson, CA and Possell, M and Seymour, JR and Raina, JB and Suggett, DJ}, title = {Coral endosymbionts (Symbiodiniaceae) emit species-specific volatilomes that shift when exposed to thermal stress.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {17395}, pmid = {31758008}, issn = {2045-2322}, mesh = {Adaptation, Biological/physiology ; Animals ; Anthozoa/metabolism/*parasitology ; Coral Reefs ; Dinoflagellida/*metabolism ; Ecosystem ; Gas Chromatography-Mass Spectrometry ; Heat-Shock Response/*physiology ; Hot Temperature ; Species Specificity ; Symbiosis/*physiology ; Volatile Organic Compounds/*metabolism ; }, abstract = {Biogenic volatile organic compounds (BVOCs) influence organism fitness by promoting stress resistance and regulating trophic interactions. Studies examining BVOC emissions have predominantly focussed on terrestrial ecosystems and atmospheric chemistry - surprisingly, highly productive marine ecosystems remain largely overlooked. Here we examined the volatilome (total BVOCs) of the microalgal endosymbionts of reef invertebrates, Symbiodiniaceae. We used GC-MS to characterise five species (Symbiodinium linucheae, Breviolum psygmophilum, Durusdinium trenchii, Effrenium voratum, Fugacium kawagutii) under steady-state growth. A diverse range of 32 BVOCs were detected (from 12 in D. trenchii to 27 in S. linucheae) with halogenated hydrocarbons, alkanes and esters the most common chemical functional groups. A thermal stress experiment on thermally-sensitive Cladocopium goreaui and thermally-tolerant D. trenchii significantly affected the volatilomes of both species. More BVOCs were detected in D. trenchii following thermal stress (32 °C), while fewer BVOCs were recorded in stressed C. goreaui. The onset of stress caused dramatic increases of dimethyl-disulfide (98.52%) in C. goreaui and nonanoic acid (99.85%) in D. trenchii. This first volatilome analysis of Symbiodiniaceae reveals that both species-specificity and environmental factors govern the composition of BVOC emissions among the Symbiodiniaceae, which potentially have, as yet unexplored, physiological and ecological importance in shaping coral reef community functioning.}, }
@article {pmid31750894, year = {2019}, author = {López-Madrigal, S and Duarte, EH}, title = {Titer regulation in arthropod-Wolbachia symbioses.}, journal = {FEMS microbiology letters}, volume = {366}, number = {23}, pages = {}, doi = {10.1093/femsle/fnz232}, pmid = {31750894}, issn = {1574-6968}, mesh = {Animals ; Arthropods/*microbiology ; Bacterial Load ; Environment ; Symbiosis/*physiology ; Wolbachia/*physiology ; }, abstract = {Symbiosis between intracellular bacteria (endosymbionts) and animals are widespread. The alphaproteobacterium Wolbachia pipientis is known to maintain a variety of symbiotic associations, ranging from mutualism to parasitism, with a wide range of invertebrates. Wolbachia infection might deeply affect host fitness (e.g. reproductive manipulation and antiviral protection), which is thought to explain its high prevalence in nature. Bacterial loads significantly influence both the infection dynamics and the extent of bacteria-induced host phenotypes. Hence, fine regulation of bacterial titers is considered as a milestone in host-endosymbiont interplay. Here, we review both environmental and biological factors modulating Wolbachia titers in arthropods.}, }
@article {pmid31744432, year = {2019}, author = {Shan, HW and Luan, JB and Liu, YQ and Douglas, AE and Liu, SS}, title = {The inherited bacterial symbiont Hamiltonella influences the sex ratio of an insect host.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1915}, pages = {20191677}, pmid = {31744432}, issn = {1471-2954}, mesh = {Animals ; Enterobacteriaceae/*physiology ; Female ; Hemiptera/*microbiology/*physiology ; Male ; Reproduction ; *Sex Ratio ; *Symbiosis ; }, abstract = {In many intracellular symbioses, the microbial symbionts provide nutrients advantageous to the host. However, the function of Hamiltonella defensa, a symbiotic bacterium localized in specialized host cells (bacteriocytes) of a whitefly Bemisia tabaci, is uncertain. We eliminate this bacterium from its whitefly host by two alternative methods: heat treatment and antibiotics. The sex ratio of the host progeny and subsequent generations of Hamiltonella-free females was skewed from 1 : 1 (male : female) to an excess of males, often exceeding a ratio of 20 : 1. B. tabaci is haplodiploid, with diploid females derived from fertilized eggs and haploid males from unfertilized eggs. The Hamiltonella status of the insect did not affect copulation frequency or sperm reserve in the spermathecae, indicating that the male-biased sex ratio is unlikely due to the limitation of sperm but likely to be associated with events subsequent to sperm transfer to the female insects, such as failure in fertilization. The host reproductive response to Hamiltonella elimination is consistent with two alternative processes: adaptive shift in sex allocation by females and a constitutive compensatory response of the insect to Hamiltonella-mediated manipulation. Our findings suggest that a bacteriocyte symbiont influences the reproductive output of female progeny in a haplodiploid insect.}, }
@article {pmid31740601, year = {2019}, author = {Zhang, B and Leonard, SP and Li, Y and Moran, NA}, title = {Obligate bacterial endosymbionts limit thermal tolerance of insect host species.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {49}, pages = {24712-24718}, pmid = {31740601}, issn = {1091-6490}, mesh = {Animals ; Aphids/microbiology/*physiology ; Buchnera/isolation &amp; purification/*physiology ; Female ; Host Specificity/physiology ; Hot Temperature/adverse effects ; Symbiosis/*physiology ; Thermotolerance/*physiology ; }, abstract = {The thermal tolerance of an organism limits its ecological and geographic ranges and is potentially affected by dependence on temperature-sensitive symbiotic partners. Aphid species vary widely in heat sensitivity, but almost all aphids are dependent on the nutrient-provisioning intracellular bacterium Buchnera, which has evolved with aphids for 100 million years and which has a reduced genome potentially limiting heat tolerance. We addressed whether heat sensitivity of Buchnera underlies variation in thermal tolerance among 5 aphid species. We measured how heat exposure of juvenile aphids affects later survival, maturation time, and fecundity. At one extreme, heat exposure of Aphis gossypii enhanced fecundity and had no effect on the Buchnera titer. In contrast, heat suppressed Buchnera populations in Aphis fabae, which suffered elevated mortality, delayed development and reduced fecundity. Likewise, in Acyrthosiphon kondoi and Acyrthosiphon pisum, heat caused rapid declines in Buchnera numbers, as well as reduced survivorship, development rate, and fecundity. Fecundity following heat exposure is severely decreased by a Buchnera mutation that suppresses the transcriptional response of a gene encoding a small heat shock protein. Similarly, absence of this Buchnera heat shock gene may explain the heat sensitivity of Ap. fabae Fluorescent in situ hybridization revealed heat-induced deformation and shrinkage of bacteriocytes in heat-sensitive species but not in heat-tolerant species. Sensitive and tolerant species also differed in numbers and transcriptional responses of heat shock genes. These results show that shifts in Buchnera heat sensitivity contribute to host variation in heat tolerance.}, }
@article {pmid31739792, year = {2019}, author = {Li, Y and Tassia, MG and Waits, DS and Bogantes, VE and David, KT and Halanych, KM}, title = {Genomic adaptations to chemosymbiosis in the deep-sea seep-dwelling tubeworm Lamellibrachia luymesi.}, journal = {BMC biology}, volume = {17}, number = {1}, pages = {91}, pmid = {31739792}, issn = {1741-7007}, mesh = {Animals ; *Chemoautotrophic Growth ; Genome/*physiology ; Hydrothermal Vents ; Polychaeta/*genetics/*microbiology ; Symbiosis/*physiology ; }, abstract = {BACKGROUND: Symbiotic relationships between microbes and their hosts are widespread and diverse, often providing protection or nutrients, and may be either obligate or facultative. However, the genetic mechanisms allowing organisms to maintain host-symbiont associations at the molecular level are still mostly unknown, and in the case of bacterial-animal associations, most genetic studies have focused on adaptations and mechanisms of the bacterial partner. The gutless tubeworms (Siboglinidae, Annelida) are obligate hosts of chemoautotrophic endosymbionts (except for Osedax which houses heterotrophic Oceanospirillales), which rely on the sulfide-oxidizing symbionts for nutrition and growth. Whereas several siboglinid endosymbiont genomes have been characterized, genomes of hosts and their adaptations to this symbiosis remain unexplored.<br><br>RESULTS: Here, we present and characterize adaptations of the cold seep-dwelling tubeworm Lamellibrachia luymesi, one of the longest-lived solitary&#xa0;invertebrates. We sequenced the worm's ~&#x2009;688-Mb haploid genome with an overall completeness of ~&#x2009;95% and discovered that L. luymesi lacks many genes essential in amino acid biosynthesis, obligating them to products provided by symbionts. Interestingly, the host is known to carry hydrogen sulfide to thiotrophic endosymbionts using hemoglobin. We also found an expansion of hemoglobin B1 genes, many of which possess a free cysteine residue which is hypothesized to function in sulfide binding. Contrary to previous analyses, the sulfide binding mediated by zinc ions is not conserved across tubeworms. Thus, the sulfide-binding mechanisms in sibgolinids need to be further explored, and B1 globins might play a more important role than previously thought. Our comparative analyses also suggest the Toll-like receptor pathway may be essential for tolerance/sensitivity to symbionts and pathogens. Several genes related to the worm's unique life history which are known to play important roles in apoptosis, cell proliferation, and aging were also identified. Last, molecular clock analyses based on phylogenomic data suggest modern siboglinid diversity originated in 267&#xa0;mya (&#xb1;&#x2009;70&#xa0;my) support previous hypotheses indicating a Late Mesozoic or Cenozoic origins of approximately 50-126&#xa0;mya for vestimentiferans.<br><br>CONCLUSIONS: Here, we elucidate several specific adaptations along various molecular pathways that link phenome to genome to improve understanding of holobiont evolution. Our findings of adaptation in genomic mechanisms to reducing environments likely extend to other chemosynthetic symbiotic systems.}, }
@article {pmid31737016, year = {2019}, author = {Foo, E and Plett, JM and Lopez-Raez, JA and Reid, D}, title = {Editorial: The Role of Plant Hormones in Plant-Microbe Symbioses.}, journal = {Frontiers in plant science}, volume = {10}, number = {}, pages = {1391}, doi = {10.3389/fpls.2019.01391}, pmid = {31737016}, issn = {1664-462X}, }
@article {pmid31730153, year = {2020}, author = {Richardson, LGL and Schnell, DJ}, title = {Origins, function, and regulation of the TOC-TIC general protein import machinery of plastids.}, journal = {Journal of experimental botany}, volume = {71}, number = {4}, pages = {1226-1238}, pmid = {31730153}, issn = {1460-2431}, support = {R01 GM061893/GM/NIGMS NIH HHS/United States ; }, mesh = {Chloroplast Proteins/genetics/metabolism ; Chloroplasts/metabolism ; *Plant Proteins/genetics/metabolism ; *Plastids/metabolism ; Protein Transport ; }, abstract = {The evolution of chloroplasts from the original endosymbiont involved the transfer of thousands of genes from the ancestral bacterial genome to the host nucleus, thereby combining the two genetic systems to facilitate coordination of gene expression and achieve integration of host and organelle functions. A key element of successful endosymbiosis was the evolution of a unique protein import system to selectively and efficiently target nuclear-encoded proteins to their site of function within the chloroplast after synthesis in the cytoplasm. The chloroplast TOC-TIC (translocon at the outer chloroplast envelope-translocon at the inner chloroplast envelope) general protein import system is conserved across the plant kingdom, and is a system of hybrid origin, with core membrane transport components adapted from bacterial protein targeting systems, and additional components adapted from host genes to confer the specificity and directionality of import. In vascular plants, the TOC-TIC system has diversified to mediate the import of specific, functionally related classes of plastid proteins. This functional diversification occurred as the plastid family expanded to fulfill cell- and tissue-specific functions in terrestrial plants. In addition, there is growing evidence that direct regulation of TOC-TIC activities plays an essential role in the dynamic remodeling of the organelle proteome that is required to coordinate plastid biogenesis with developmental and physiological events.}, }
@article {pmid31722669, year = {2019}, author = {Sauvage, T and Schmidt, WE and Yoon, HS and Paul, VJ and Fredericq, S}, title = {Promising prospects of nanopore sequencing for algal hologenomics and structural variation discovery.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {850}, pmid = {31722669}, issn = {1471-2164}, mesh = {Caulerpa/*genetics ; Genome, Bacterial ; *Genome, Chloroplast ; Genome, Mitochondrial ; Genomics/methods ; Nanopore Sequencing/*methods ; Polymorphism, Genetic ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA/*methods ; }, abstract = {BACKGROUND: The MinION Access Program (MAP, 2014-2016) allowed selected users to test the prospects of long nanopore reads for diverse organisms and applications through the rapid development of improving chemistries. In 2014, faced with a fragmented Illumina assembly for the chloroplast genome of the green algal holobiont Caulerpa ashmeadii, we applied to the MAP to test the prospects of nanopore reads to investigate such intricacies, as well as further explore the hologenome of this species with native and hybrid approaches.<br><br>RESULTS: The chloroplast genome could only be resolved as a circular molecule in nanopore assemblies, which also revealed structural variants (i.e. chloroplast polymorphism or heteroplasmy). Signal and Illumina polishing of nanopore-assembled organelle genomes (chloroplast and mitochondrion) reflected the importance of coverage on final quality and current limitations. In hybrid assembly, our modest nanopore data sets showed encouraging results to improve assembly length, contiguity, repeat content, and binning of the larger nuclear and bacterial genomes. Profiling of the holobiont with nanopore or Illumina data unveiled a dominant Rhodospirillaceae (Alphaproteobacteria) species among six putative endosymbionts. While very fragmented, the cumulative hybrid assembly length of C. ashmeadii's nuclear genome reached 24.4 Mbp, including 2.1 Mbp in repeat, ranging closely with GenomeScope's estimate (>&#x2009;26.3 Mbp, including 4.8 Mbp in repeat).<br><br>CONCLUSION: Our findings relying on a very modest number of nanopore R9 reads as compared to current output with newer chemistries demonstrate the promising prospects of the technology for the assembly and profiling of an algal hologenome and resolution of structural variation. The discovery of polymorphic 'chlorotypes' in C. ashmeadii, most likely mediated by homing endonucleases and/or retrohoming by reverse transcriptases, represents the first report of chloroplast heteroplasmy in the siphonous green algae. Improving contiguity of C. ashmeadii's nuclear and bacterial genomes will require deeper nanopore sequencing to greatly increase the coverage of these larger genomic compartments.}, }
@article {pmid31720723, year = {2020}, author = {Wang, D and Wei, C}, title = {Bacterial communities in digestive and excretory organs of cicadas.}, journal = {Archives of microbiology}, volume = {202}, number = {3}, pages = {539-553}, doi = {10.1007/s00203-019-01763-4}, pmid = {31720723}, issn = {1432-072X}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; *Gastrointestinal Microbiome ; Gastrointestinal Tract/microbiology ; Hemiptera/*microbiology ; Phylogeny ; }, abstract = {Bacteriocyte-associated symbionts are essential for the health of many sap-sucking insects, such as cicadas, leafhoppers and treehoppers, etc., but little is known about the bacterial community in the gut and other related organs in these insects. We characterized the bacterial communities in the salivary glands, alimentary canal and the Malpighian tubules of two populations of the cicada Subpsaltria yangi occurring in different habitats and feeding on different hosts. A high degree of similarity of core microbiota was revealed between the two populations, both with the top three bacteria belonging to Meiothermus, Candidatus Sulcia and Halomonas. The bacterial communities in various organs clustered moderately by populations possibly reflect adaptive changes in the microbiota of related S. yangi populations, which provide a better understanding of the speciation and adaptive mechanism of this species to different diets and habitats. When compared with two phylogenetically distant cicada species, Hyalessa maculaticollis and Meimuna mongolica, the core microbiota in S. yangi was significantly different to that of these species. In addition, our results confirm that Ca. Sulcia distributes in the digestive and excretory organs besides the bacteriomes and gonads, which provide potential important information onto the trophic functions of this obligate endosymbiont to the host insects.}, }
@article {pmid31716328, year = {2019}, author = {Normark, BB and Okusu, A and Morse, GE and Peterson, DA and Itioka, T and Schneider, SA}, title = {Phylogeny and classification of armored scale insects (Hemiptera: Coccomorpha: Diaspididae).}, journal = {Zootaxa}, volume = {4616}, number = {1}, pages = {zootaxa.4616.1.1}, doi = {10.11646/zootaxa.4616.1.1}, pmid = {31716328}, issn = {1175-5334}, mesh = {Animals ; Bayes Theorem ; *Hemiptera ; Phylogeny ; }, abstract = {Armored scale insects (Hemiptera: Coccomorpha: Diaspididae) are major economic pests and are among the world's most invasive species. Here we describe a system of specimen and identification management that establishes a basis for well-vouchered molecular identification. We also present an expanded Bayesian phylogenetic analysis based on concatenated fragments of 4 genetic loci: the large ribosomal subunit (28S), elongation factor-1 alpha (EF-1α), cytochrome oxidase I and II (COI‒II), and the small ribosomal subunit (16S) of the primary endosymbiont, Uzinura diaspidicola (Bacteroidetes: Flavobacteriales). Our sample includes 1,389 individuals, representing 11 outgroup species and at least 311 described and 61 undescribed diaspidid species. The results broadly support Takagi's 2002 classification but indicate that some revisions are needed. We propose a revised classification recognizing 4 subfamilies: Ancepaspidinae Borchsenius, new rank, Furcaspidinae Balachowsky, new rank, Diaspidinae Targioni Tozzetti, and Aspidiotinae Westwood. Within Aspidiotinae, in addition to the existing tribes Aspidiotini Westwood, Parlatoriini Leonardi, Odonaspidini Ferris, Leucaspidini Atkinson, and Smilacicolini Takagi, we recognize as tribes Gymnaspidini Balachowsky, new rank, and Aonidiini Balachowsky, new rank. Within Diaspidinae we recognize the 2 tribes Lepidosaphidini Shimer and Diaspidini Targioni Tozzetti, and within Diaspidini we recognize three subtribes: Diaspidina Targioni Tozzetti, Fioriniina Leonardi, and Chionaspidina Brues Melander. We regard Kuwanaspidina Borchsenius as a junior synonym of Fioriniina, Thysanaspidini Takagi as a junior synonym of Leucaspidini, and Protodiaspidina Takagi and Ulucoccinae Takagi as junior synonyms of Chionaspidina. To clarify the composition of the higher taxa we describe 2 new genera for Australian species heretofore misplaced in the genus Ancepaspis Ferris: Brimblecombia Normark (Aonidiini) and Hendersonaspis Normark (Leucaspidini). We also propose many additional minor modifications to the taxonomy of Diaspididae, including the following new combinations, revived combinations, and replacement names: Aonidia edgerleyi (Mamet), new combination (from Bigymnaspis Balachowsky); Aonidomytilus espinosai Porter, revived combination (from Porterinaspis González); Aspidiotus badius (Brain), new combination (this and the next 5 Aspidiotus species all from Aonidia Targioni Tozzetti); Aspidiotus biafrae (Lindinger), new combination; Aspidiotus chaetachmeae (Brain), new combination; Aspidiotus laticornis (Balachowsky), new combination; Aspidiotus rhusae (Brain), new combination; Aspidiotus sclerosus (Munting), new combination; Brimblecombia asperata (Brimblecombe), new combination (this and the next 5 Brimblecombia species all from Ancepaspis); Brimblecombia longicauda (Brimblecombe), new combination; Brimblecombia magnicauda (Brimblecombe), new combination; Brimblecombia reticulata (Brimblecombe), new combination; Brimblecombia rotundicauda (Brimblecombe), new combination; Brimblecombia striata (Brimblecombe), new combination; Cooleyaspis pseudomorpha (Leonardi), new combination (from Dinaspis Leonardi); Cupidaspis wilkeyi (Howell Tippins), new combination (from Paracupidaspis Howell Tippins); Cupressaspis isfarensis Borchsenius, revived combination (this species, the next 2 species in Cupressaspis Borchsenius, revived genus, and the next 9 species in Diaspidiotus Cockerell all from Aonidia); Cupressaspis mediterranea (Lindinger), revived combination; Cupressaspis relicta (Balachowsky), new combination; Diaspidiotus atlanticus (Ferris), new combination; Diaspidiotus marginalis (Brain), new combination; Diaspidiotus maroccanus (Balachowsky), new combination; Diaspidiotus mesembryanthemae (Brain), new combination; Diaspidiotus opertus (De Lotto), new combination; Diaspidiotus shastae (Coleman), new combination; Diaspidiotus simplex (Leonardi), new combination; Diaspidiotus visci (Hall), new combination; Diaspidiotus yomae (Munting), new combination; Diaspis arundinariae (Tippins Howell), new combination (from Geodiaspis Tippins Howell); Duplachionaspis arecibo (Howell), new combination (this and the next 10 Duplachionaspis MacGillivray species all from Haliaspis Takagi); Duplachionaspis asymmetrica Ferris, revived combination; Duplachionaspis distichlii (Ferris), revived combination; Duplachionaspis litoralis Ferris, revived combination; Duplachionaspis mackenziei McDaniel, revived combination; Duplachionaspis milleri (Howell), new combination; Duplachionaspis nakaharai (Howell), new combination; Duplachionaspis peninsularis (Howell), new combination; Duplachionaspis spartinae (Comstock), revived combination; Duplachionaspis texana (Liu Howell) new combination; Duplachionaspis uniolae (Takagi), new combination; Duplachionaspis mutica (Williams) (from Aloaspis Williams), new combination; Epidiaspis doumtsopi (Schneider), new combination (from Diaspis Costa); Fiorinia ficicola (Takahashi), new combination (from Ichthyaspis Takagi); Fiorinia macroprocta (Leonardi), revived combination (this and the next 2 species of Fiorinia Targioni Tozzetti all from Trullifiorinia Leonardi); Fiorinia rubrolineata Leonardi, revived combination; Fiorinia scrobicularum Green, revived combination; Genaparlatoria pseudaspidiotus (Lindinger), revived combination (from Parlatoria); Greeniella acaciae (Froggatt), new combination (this and the next 4 Greeniella Cockerell species all from Gymnaspis Newstead); Greeniella cassida (Hall Williams), new combination; Greeniella grandis (Green), new combination; Greeniella perpusilla (Maskell), new combination; Greeniella serrata (Froggatt), new combination; Hendersonaspis anomala (Green), new combination (from Ancepaspis); Hulaspis bulba (Munting), new combination (this and the next Hulaspis Hall species both from Andaspis MacGillivray); Hulaspis formicarum (Ben-Dov), new combination; Lepidosaphes antidesmae (Rao in Rao Ferris), new combination (this and the next 19 species all from Andaspis); Lepidosaphes arcana (Matile-Ferrero), new combination; Lepidosaphes betulae (Borchsenius), new combination; Lepidosaphes citricola (Young Hu), new combination; Lepidosaphes conocarpi (Takagi), new combination; Lepidosaphes crawi (Cockerell), revived combination; Lepidosaphes erythrinae Rutherford, revived combination; Lepidosaphes incisor Green, revived combination; Lepidosaphes indica (Borchsenius), new combination; Lepidosaphes kashicola Takahashi, revived combination; Lepidosaphes kazimiae (Williams), new combination; Lepidosaphes laurentina (Almeida), new combination; Lepidosaphes maai (Williams Watson), new combination; Lepidosaphes mackieana McKenzie, revived combination; Lepidosaphes micropori (Borchsenius), new combination; Lepidosaphes punicae Laing, revived combination; Lepidosaphes quercicola (Borchsenius), new combination; Lepidosaphes recurrens (Takagi Kawai), new combination; Lepidosaphes viticis (Takagi), new combination; Lepidosaphes xishuanbannae (Young Hu), new combination; Lepidosaphes giffardi (Adachi Fullaway), new combination (from Carulaspis MacGillivray); Lepidosaphes garciniae (Young Hu), new combination (this and the next 2 species all from Ductofrontaspis Young Hu); Lepidosaphes huangyangensis (Young Hu), new combination; Lepidosaphes jingdongensis (Young Hu), new combination; Lepidosaphes recurvata (Froggatt), revived combination (from Metandaspis Williams); Lepidosaphes ficicola Takahashi, revived combination (this and the next 2 species all from Ungulaspis MacGillivray); Lepidosaphes pinicolous Chen, revived combination; Lepidosaphes ungulata Green, revived combination; Lepidosaphes serrulata (Ganguli), new combination (from Velataspis Ferris); Lepidosaphes huyoung Normark, replacement name for Andaspis ficicola Young Hu; Lepidosaphes tangi Normark, replacement name for Andaspis schimae Tang; Lepidosaphes yuanfeng Normark, replacement name for Andaspis keteleeriae Yuan Feng; Leucaspis ilicitana (Gómez-Menor), new combination (from Aonidia); Lopholeucaspis spinomarginata (Green), new combination (from Gymnaspis); Melanaspis campylanthi (Lindinger), new combination (from Aonidia); Mohelnaspis bidens (Green), new combination (from Fiorinia); Parlatoria affinis (Ramakrishna Ayyar), new combination (this and the next 4 Parlatoria species all from Gymnaspis); Parlatoria ficus (Ramakrishna Ayyar), new combination; Parlatoria mangiferae (Ramakrishna Ayyar), new combination; Parlatoria ramakrishnai (Green), new combination; Parlatoria sclerosa (Munting), new combination; Parlatoria bullata (Green), new combination (from Bigymnaspis); Parlatoria leucaspis (Lindinger), new combination (this and the next species both from Cryptoparlatorea Lindinger); Parlatoria pini (Takahashi), new combination; Parlatoria tangi Normark, replacement name for Parlatoria pini Tang; Pseudoparlatoria bennetti (Williams), new combination (from Parlagena McKenzie); Pseudoparlatoria chinchonae (McKenzie), new combination (from Protodiaspis Cockerell); Pseudoparlatoria larreae (Leonardi), revived combination (from Protargionia Leonardi); Quernaspis lepineyi (Balachowsky), new combination (from Chionaspis); Rhizaspidiotus nullispinus (Munting), new combination (from Aonidia); Rolaspis marginalis (Leonardi), new combination (from Lepidosaphes); Salicicola lepelleyi (De Lotto), new combination (from Anotaspis Ferris); Tecaspis giffardi (Leonardi), new combination (from Dinaspis); Trullifiorinia geijeriae (Froggatt), new combination (from Fiorinia); Trullifiorinia nigra (Lindinger), new combination (from Crypthemichionaspis Lindinger); and Voraspis olivina (Leonardi), new combination (from Lepidosaphes).}, }
@article {pmid31715700, year = {2019}, author = {Yin, X and Zhao, S and Yan, B and Tian, Y and Ba, T and Zhang, J and Wang, Y}, title = {Bartonella rochalimae, B. grahamii, B. elizabethae, and Wolbachia spp. in Fleas from Wild Rodents near the China-Kazakhstan Border.}, journal = {The Korean journal of parasitology}, volume = {57}, number = {5}, pages = {553-559}, pmid = {31715700}, issn = {1738-0006}, mesh = {Animals ; Animals, Wild/microbiology ; Bartonella/classification/genetics/*isolation &amp; purification ; Bartonella Infections/microbiology/*veterinary ; China ; Genotype ; Kazakhstan ; Phylogeny ; Rodent Diseases/*microbiology ; Rodentia/classification/*microbiology ; Siphonaptera/classification/*microbiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {The Alataw Pass, near the Ebinur Lake Wetland (northwest of China) and Taldykorgan (east of Kazakhstan), is a natural habitat for wild rodents. To date, little has been done on the surveillance of Bartonella spp. and Wolbachia spp. from fleas in the region. Here we molecularly detected Bartonella spp. and Wolbachia spp. in wild rodent fleas during January and October of 2016 along the Alataw Pass-Kazakhstan border. A total of 1,706 fleas belonging to 10 species were collected from 6 rodent species. Among the 10 flea species, 4 were found to be positive for Wolbachia, and 5 flea species were positive for Bartonella. Molecular analysis indicated that i) B. rochalimae was firstly identified in Xenopsylla gerbilli minax and X. conforms conforms, ii) B. grahamii was firstly identified in X. gerbilli minax, and iii) B. elizabethae was firstly detected in Coptopsylla lamellifer ardua, Paradoxopsyllus repandus, and Nosopsyllus laeviceps laeviceps. Additionally, 3 Wolbachia endosymbionts were firstly found in X. gerbilli minax, X. conforms conforms, P. repandus, and N. laeviceps laeviceps. BLASTn analysis indicated 3 Bartonella species showed genotypic variation. Phylogenetic analysis revealed 3 Wolbachia endosymbionts were clustered into the non-Siphonaptera Wolbachia group. These findings extend our knowledge of the geographical distribution and carriers of B. rochalimae, B. grahamii, B. elizabethae, and Wolbachia spp. In the future, there is a need for China-Kazakhstan cooperation to strengthen the surveillance of flea-borne pathogens in wildlife.}, }
@article {pmid31713895, year = {2020}, author = {Clanner-Engelshofen, BM and French, LE and Reinholz, M}, title = {Corynebacterium kroppenstedtii subsp. demodicis is the endobacterium of Demodex folliculorum.}, journal = {Journal of the European Academy of Dermatology and Venereology : JEADV}, volume = {34}, number = {5}, pages = {1043-1049}, doi = {10.1111/jdv.16069}, pmid = {31713895}, issn = {1468-3083}, mesh = {Animals ; *Bacillus ; Corynebacterium ; Humans ; *Mite Infestations ; *Mites ; }, abstract = {BACKGROUND: Demodex spp. mites are the most complex member of the human skin microbiome. Mostly they are commensals, although their pathophysiological role in inflammatory dermatoses is recognized. Demodex mites cannot be cultivated in vitro, so only little is known about their life cycle, biology and physiology. Different bacterial species have been suggested to be the endobacterium of Demodex mites, including Bacillus oleronius, B. simplex, B. cereus and B. pumilus.<br><br>OBJECTIVES: Our aim was to find the true endobacterium of human Demodex mites.<br><br>METHODS: The distinct genetic and phenotypic differences and similarities between the type strain and native isolates are described by DNA sequencing, PCR, MALDI-TOF, DNA-DNA hybridization, fatty and mycolic acid analyses, and antibiotic resistance testing.<br><br>RESULTS: We report the true endobacterium of Demodex folliculorum, independent of the sampling source of mites or life stage: Corynebacterium kroppenstedtii subsp. demodicis.<br><br>CONCLUSIONS: We anticipate our finding to be a starting point for more in-depth understanding of the tripartite microbe-host interaction between Demodex mites, its bacterial endosymbiont and the human host.}, }
@article {pmid31709681, year = {2020}, author = {Damjanovic, K and Menéndez, P and Blackall, LL and van Oppen, MJH}, title = {Mixed-mode bacterial transmission in the common brooding coral Pocillopora acuta.}, journal = {Environmental microbiology}, volume = {22}, number = {1}, pages = {397-412}, doi = {10.1111/1462-2920.14856}, pmid = {31709681}, issn = {1462-2920}, support = {DP160101468//Australian Research Council/International ; FL180100036//Australian Research Council/International ; Holsworth Wildlife Endowment//Ecological Society of Australia/International ; //Holsworth Wildlife Research Endowment/International ; //Australian Institute of Marine Science/International ; }, mesh = {Animals ; Anthozoa/*microbiology ; *Coral Reefs ; Dinoflagellida/*classification/genetics/isolation &amp; purification ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; Microbiota ; RNA, Ribosomal, 16S/genetics ; Rhodobacteraceae/*classification/genetics/isolation &amp; purification ; }, abstract = {Reef-building corals form associations with a huge diversity of microorganisms, which are essential for the survival and well-being of their host. While the acquisition patterns of Symbiodiniaceae microalgal endosymbionts are strongly linked to the coral's reproductive strategy, few studies have investigated the transmission mode of bacteria, especially in brooding species. Here, we relied on 16S rRNA gene and Internal Transcribed Spacer 2 marker metabarcoding in conjunction with fluorescence in situ hybridisation microscopy to describe the onset of microbial associations in the common brooding coral Pocillopora acuta. We analysed the bacterial and Symbiodiniaceae community composition in five adult colonies, their larvae, and 4-day old recruits. Larvae and recruits inherited Symbiodiniaceae, as well as a small number of bacterial strains, from their parents. Rhodobacteraceae and Endozoicomonas were among the most abundant taxa that were likely maternally transmitted to the offspring. The presence of bacterial aggregates in newly released larvae was observed with confocal microscopy, confirming the occurrence of vertical transmission of bacteria in P. acuta. We concluded that host factors, as well as the environmental bacterial pool influenced the microbiome of P. acuta.}, }
@article {pmid31705651, year = {2020}, author = {Igloi, GL}, title = {Molecular evidence for the evolution of the eukaryotic mitochondrial arginyl-tRNA synthetase from the prokaryotic suborder Cystobacterineae.}, journal = {FEBS letters}, volume = {594}, number = {5}, pages = {951-957}, doi = {10.1002/1873-3468.13665}, pmid = {31705651}, issn = {1873-3468}, mesh = {Amino Acid Sequence ; Arginine-tRNA Ligase/*genetics ; Bacterial Proteins/genetics ; Cloning, Molecular ; Data Mining ; Eukaryota/*enzymology/genetics ; Evolution, Molecular ; Mitochondria/*enzymology/genetics ; Myxococcales/*enzymology/genetics ; Phylogeny ; Sequence Alignment ; Sequence Homology, Amino Acid ; }, abstract = {The evolutionary origin of the family of eukaryotic aminoacyl-tRNA synthetases that are essential to all living organisms is a matter of debate. In order to shed molecular light on the ancient source of arginyl-tRNA synthetase, a total of 1347 eukaryotic arginyl-tRNA synthetase sequences were mined from databases and analyzed. Their multiple sequence alignment reveals a signature sequence that is characteristic of the nuclear-encoded enzyme, which is imported into mitochondria. Using this molecular beacon, the origins of this gene can be traced to modern prokaryotes. In this way, a previous phylogenetic analysis linking Myxococcus to the emergence of the eukaryotic mitochondrial arginyl-tRNA synthetase is supported by the unique existence of the molecular signature within the suborder Cystobacterineae that includes Myxococcus.}, }
@article {pmid31704208, year = {2020}, author = {Hodo, CL and Forgacs, D and Auckland, LD and Bass, K and Lindsay, C and Bingaman, M and Sani, T and Colwell, K and Hamer, GL and Hamer, SA}, title = {Presence of diverse Rickettsia spp. and absence of Borrelia burgdorferi sensu lato in ticks in an East Texas forest with reduced tick density associated with controlled burns.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {1}, pages = {101310}, doi = {10.1016/j.ttbdis.2019.101310}, pmid = {31704208}, issn = {1877-9603}, mesh = {Amblyomma/*microbiology ; Animals ; Borrelia burgdorferi Group/*isolation &amp; purification ; Fires/prevention &amp; control ; Forestry/*methods ; Forests ; Ixodes/*microbiology ; Population Density ; Rickettsia/*isolation &amp; purification ; Texas ; }, abstract = {As tick-borne diseases continue to emerge across the United States, there is need for a better understanding of the tick and pathogen communities in the southern states and of habitat features that influence transmission risk. We surveyed questing and on-host ticks in pine-dominated forests with various fire management regimes in the Sam Houston National Forest, a popular recreation area near Houston, Texas. Four linear transects were established- two with a history of controlled burns, and two unburned. Systematic drag sampling yielded 112 ticks from two species, Ixodes scapularis (n=73) and Amblyomma americanum (n=39), with an additional 106 questing ticks collected opportunistically from drag cloth operators. There was a significant difference in systematically-collected questing tick density between unburned (15 and 18 ticks/1000 m[2]) and burned (2 and 4 ticks/1000 m[2]) transects. We captured 106 rodents and found 74 ticks on the rodents, predominantly Dermacentor variabilis. One unburned transect had significantly more ticks per mammal than any of the other three transects. DNA of Rickettsia species was detected in 146/292 on and off-host ticks, including the 'Rickettsial endosymbiont of I. scapularis' and Rickettsia amblyommatis, which are of uncertain pathogenicity to humans. Borrelia lonestari was detected in one A. americanum, while Borrelia burgdorferi sensu stricto, the agent of Lyme disease, was not detected in any tick samples. Neither Borrelia nor Rickettsia spp. were detected in any of the mammal ear biopsies (n=64) or blood samples (n=100) tested via PCR. This study documents a high prevalence in ticks of Rickettsia spp. thought to be endosymbionts, a low prevalence of relapsing fever group Borrelia in ticks, and a lack of detection of Lyme disease-group Borrelia in both ticks and mammals in an east Texas forested recreation area. Additionally, we observed low questing tick density in areas with a history of controlled burns. These results expand knowledge of tick-borne disease ecology in east Texas which can aid in directing future investigative, modeling, and management efforts.}, }
@article {pmid31702774, year = {2020}, author = {Julca, I and Marcet-Houben, M and Cruz, F and Vargas-Chavez, C and Johnston, JS and Gómez-Garrido, J and Frias, L and Corvelo, A and Loska, D and Cámara, F and Gut, M and Alioto, T and Latorre, A and Gabaldón, T}, title = {Phylogenomics Identifies an Ancestral Burst of Gene Duplications Predating the Diversification of Aphidomorpha.}, journal = {Molecular biology and evolution}, volume = {37}, number = {3}, pages = {730-756}, pmid = {31702774}, issn = {1537-1719}, mesh = {Animals ; Aphids/*classification/*genetics ; Evolution, Molecular ; *Gene Duplication ; Gene Expression Profiling/*methods ; Gene Expression Regulation ; High-Throughput Nucleotide Sequencing ; Insect Proteins/genetics ; Phylogeny ; Species Specificity ; Synteny ; Whole Genome Sequencing/*methods ; }, abstract = {Aphids (Aphidoidea) are a diverse group of hemipteran insects that feed on plant phloem sap. A common finding in studies of aphid genomes is the presence of a large number of duplicated genes. However, when these duplications occurred remains unclear, partly due to the high relatedness of sequenced species. To better understand the origin of aphid duplications we sequenced and assembled the genome of Cinara cedri, an early branching lineage (Lachninae) of the Aphididae family. We performed a phylogenomic comparison of this genome with 20 other sequenced genomes, including the available genomes of five other aphids, along with the transcriptomes of two species belonging to Adelgidae (a closely related clade to the aphids) and Coccoidea. We found that gene duplication has been pervasive throughout the evolution of aphids, including many parallel waves of recent, species-specific duplications. Most notably, we identified a consistent set of very ancestral duplications, originating from a large-scale gene duplication predating the diversification of Aphidomorpha (comprising aphids, phylloxerids, and adelgids). Genes duplicated in this ancestral wave are enriched in functions related to traits shared by Aphidomorpha, such as association with endosymbionts, and adaptation to plant defenses and phloem-sap-based diet. The ancestral nature of this duplication wave (106-227 Ma) and the lack of sufficiently conserved synteny make it difficult to conclude whether it originated from a whole-genome duplication event or, alternatively, from a burst of large-scale segmental duplications. Genome sequencing of other aphid species belonging to different Aphidomorpha and related lineages may clarify these findings.}, }
@article {pmid31699757, year = {2019}, author = {Basting, PJ and Bergman, CM}, title = {Complete Genome Assemblies for Three Variants of the Wolbachia Endosymbiont of Drosophila melanogaster.}, journal = {Microbiology resource announcements}, volume = {8}, number = {45}, pages = {}, pmid = {31699757}, issn = {2576-098X}, abstract = {Here, we report genome assemblies for three strains of Wolbachia pipientis, assembled from unenriched, unfiltered long-read shotgun sequencing data of geographically distinct strains of Drosophila melanogaster Our simple methodology can be applied to long-read data sets of other Wolbachia-infected species with limited Wolbachia-host lateral gene transfers to produce complete assemblies for this important model symbiont.}, }
@article {pmid31699041, year = {2019}, author = {Yuen, B and Polzin, J and Petersen, JM}, title = {Organ transcriptomes of the lucinid clam Loripes orbiculatus (Poli, 1791) provide insights into their specialised roles in the biology of a chemosymbiotic bivalve.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {820}, pmid = {31699041}, issn = {1471-2164}, mesh = {Animals ; Apoptosis/genetics ; Bacterial Physiological Phenomena ; Bivalvia/cytology/*genetics/immunology/microbiology ; Environment ; Foot/physiology ; *Gene Expression Profiling ; Immunity, Innate/genetics ; Nutrients/metabolism ; *Symbiosis ; }, abstract = {BACKGROUND: The lucinid clam Loripes orbiculatus lives in a nutritional symbiosis with sulphur-oxidizing bacteria housed in its gills. Although our understanding of the lucinid endosymbiont physiology and metabolism has made significant progress, relatively little is known about how the host regulates the symbiosis at the genetic and molecular levels. We generated transcriptomes from four L. orbiculatus organs (gills, foot, visceral mass, and mantle) for differential expression analyses, to better understand this clam's physiological adaptations to a chemosymbiotic lifestyle, and how it regulates nutritional and immune interactions with its symbionts.<br><br>RESULTS: The transcriptome profile of the symbiont-housing gill suggests the regulation of apoptosis and innate immunity are important processes in this organ. We also identified many transcripts encoding ion transporters from the solute carrier family that possibly allow metabolite exchange between host and symbiont. Despite the clam holobiont's clear reliance on chemosynthesis, the clam's visceral mass, which contains the digestive tract, is characterised by enzymes involved in digestion, carbohydrate recognition and metabolism, suggesting that L. orbiculatus has a mixotrophic diet. The foot transcriptome is dominated by the biosynthesis of glycoproteins for the construction of mucus tubes, and receptors that mediate the detection of chemical cues in the environment.<br><br>CONCLUSIONS: The transcriptome profiles of gills, mantle, foot and visceral mass provide insights into the molecular basis underlying the functional specialisation of bivalve organs adapted to a chemosymbiotic lifestyle.}, }
@article {pmid31698114, year = {2020}, author = {Karut, K and Castle, SJ and Karut, &#x15e;T and Karaca, MM}, title = {Secondary endosymbiont diversity of Bemisia tabaci and its parasitoids.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {78}, number = {}, pages = {104104}, doi = {10.1016/j.meegid.2019.104104}, pmid = {31698114}, issn = {1567-7257}, mesh = {Animals ; Arizona ; Bacteria/*classification/genetics/isolation &amp; purification ; Gammaproteobacteria/genetics/isolation &amp; purification ; Genotyping Techniques/*methods ; Hemiptera/*classification/genetics/*microbiology ; Mediterranean Region ; Phylogeography ; Rickettsia/genetics/isolation &amp; purification ; Species Specificity ; Symbiosis ; Turkey ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {Cotton whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide. It is known as a species complex consisting of at least 40 cryptic species. Although there are substantial data regarding species composition, parasitoids and endosymbionts of B. tabaci, data on relationship between the pest, parasitoids and endosymbionts are very restricted. Therefore, in this study, secondary endosymbionts in populations of B. tabaci and their parasitoids collected from Turkey and the USA were determined by PCR-based DNA analysis. Whitefly populations in Turkey represented both Mediterranean (MED) and Middle East-Asia Minor1 (MEAM1) genotypes from single or mixed populations of both genotypes. Arsenophonus, Rickettsia and Wolbachia were found in MED, while Hamiltonella and Rickettsia in MEAM1. Whitefly populations collected from Arizona were all MEAM1 and dually infected with Hamiltonella and Rickettsia. The aphelinid parasitoids Encarsia lutea and Eretmocerus mundus predominated in all Turkish populations. While almost all En. lutea populations were infected with Wolbachia, no endosymbionts were detected in any Er. mundus. Parasitoid species and the pattern of secondary endosymbiont infection in Arizona populations were different with Rickettsia detected only from Encarsia sophia while both Rickettsia and Wolbachia were found in Eretmocerus species. As a result, four secondary endosymbionts, namely, Rickettsia, Hamiltonella, Arsenophonus and Wolbachia, were detected from B.tabaci and its parasitoids. Among them only Wolbachia and Rickettsia were found in both the pest and parasitoids. It is conclude that further studies should be pursued to determine effect of these endosymbionts on biology of the parasitoids and success in biological control of B. tabaci.}, }
@article {pmid31693775, year = {2019}, author = {Bellantuono, AJ and Dougan, KE and Granados-Cifuentes, C and Rodriguez-Lanetty, M}, title = {Free-living and symbiotic lifestyles of a thermotolerant coral endosymbiont display profoundly distinct transcriptomes under both stable and heat stress conditions.}, journal = {Molecular ecology}, volume = {28}, number = {24}, pages = {5265-5281}, doi = {10.1111/mec.15300}, pmid = {31693775}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*genetics/physiology ; Coral Reefs ; Dinoflagellida/genetics ; Gene Expression Profiling ; Heat-Shock Response/*genetics ; Hot Temperature ; Life Style ; Oceans and Seas ; Photosynthesis/genetics ; Symbiosis/*genetics ; Temperature ; Thermotolerance ; Transcriptome/*genetics ; }, abstract = {Reef-building corals depend upon a nutritional endosymbiosis with photosynthetic dinoflagellates of the family Symbiodiniaceae for the majority of their energetic needs. While this mutualistic relationship is impacted by numerous stressors, warming oceans are a predominant threat to coral reefs, placing the future of the world's reefs in peril. Some Symbiodiniaceae species exhibit tolerance to thermal stress, but the in hospite symbiont response to thermal stress is underexplored. To describe the underpinnings of symbiosis and heat stress response, we compared in hospite and free-living transcriptomes of Durusdinium trenchii, a pan-tropical heat-tolerant Symbiodiniaceae species, under stable temperature conditions and acute hyperthermal stress. We discovered that symbiotic state was a larger driver of the transcriptional landscape than heat stress. The majority of differentially expressed transcripts between in hospite and free-living cells were downregulated, suggesting the in hospite condition is associated with the shutdown of numerous processes uniquely required for a free-living lifestyle. In the free-living state, we identified enrichment for numerous cell signalling pathways and other functions related to detecting and responding to a changing environment, as well as transcripts relating to mitosis, meiosis, and motility. In contrast, in hospite cells exhibited enhanced transcriptional activity for photosynthesis and carbohydrate transport as well as chromatin modifications and a disrupted circadian clock. Hyperthermal stress induced drastic alteration of transcriptional activity in hospite, suggesting symbiotic engagement with the host elicited an exacerbated stress response when compared to free-living D. trenchii. Altogether, the dramatic differences in gene expression between in hospite and free-living D. trenchii indicate the importance of considering symbiotic state in investigations of symbiosis and hyperthermal stress in Symbiodiniaceae.}, }
@article {pmid31686336, year = {2019}, author = {Durden, L and Wang, D and Panaccione, D and Clay, K}, title = {Decreased Root-Knot Nematode Gall Formation in Roots of the Morning Glory Ipomoea tricolor Symbiotic with Ergot Alkaloid-Producing Fungal Periglandula Sp.}, journal = {Journal of chemical ecology}, volume = {45}, number = {10}, pages = {879-887}, pmid = {31686336}, issn = {1573-1561}, support = {R15 GM114774/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Biomass ; Chromatography, High Pressure Liquid ; Ergot Alkaloids/analysis/*chemistry ; Hypocreales/*metabolism ; Ipomoea/chemistry/metabolism/*parasitology ; Plant Roots/metabolism/parasitology ; Plant Tumors/parasitology ; Seeds/chemistry/metabolism ; Soil/parasitology ; Spectrometry, Mass, Electrospray Ionization ; Symbiosis ; Tylenchoidea/*physiology ; }, abstract = {Many species of morning glories (Convolvulaceae) form symbioses with seed-transmitted Periglandula fungal endosymbionts, which produce ergot alkaloids and may contribute to defensive mutualism. Allocation of seed-borne ergot alkaloids to various tissues of several Ipomoea species has been demonstrated, including roots of I. tricolor. The goal of this study was to determine if infection of I. tricolor by the Periglandula sp. endosymbiont affects Southern root-knot nematode (Meloidogyne incognita) gall formation and host plant biomass. We hypothesized that I. tricolor plants infected by Periglandula (E+) would develop fewer nematode-induced galls compared to non-symbiotic plants (E-). E+ or E- status of plant lines was confirmed by testing methanol extracts from individual seeds for endosymbiont-produced ergot alkaloids. To test the effects of Periglandula on nematode colonization, E+ and E- I. tricolor seedlings were grown in soil infested with high densities of M. incognita nematodes (N+) or no nematodes (N-) for four weeks in the greenhouse before harvesting. After harvest, nematode colonization of roots was visualized microscopically, and total gall number and plant biomass were quantified. Four ergot alkaloids were detected in roots of E+ plants, but no alkaloids were found in E- plants. Gall formation was reduced by 50% in E+ plants compared to E- plants, independent of root biomass. Both N+ plants and E+ plants had significantly reduced biomass compared to N- and E- plants, respectively. These results demonstrate Periglandula's defensive role against biotic enemies, albeit with a potential trade-off with host plant growth.}, }
@article {pmid31657869, year = {2020}, author = {Murik, O and Chandran, SA and Nevo-Dinur, K and Sultan, LD and Best, C and Stein, Y and Hazan, C and Ostersetzer-Biran, O}, title = {Topologies of N[6] -adenosine methylation (m[6] A) in land plant mitochondria and their putative effects on organellar gene expression.}, journal = {The Plant journal : for cell and molecular biology}, volume = {101}, number = {6}, pages = {1269-1286}, doi = {10.1111/tpj.14589}, pmid = {31657869}, issn = {1365-313X}, mesh = {Adenosine/*metabolism ; Arabidopsis/metabolism ; Brassica/metabolism ; *Gene Expression ; Gene Expression Regulation, Plant ; Methylation ; Mitochondria/*metabolism ; Organelles/*metabolism ; Plants/*metabolism ; }, abstract = {Mitochondria serve as major sites of ATP production and play key roles in many other metabolic processes that are critical to the cell. As relicts of an ancient bacterial endosymbiont, mitochondria contain their own hereditary material (i.e. mtDNA, or mitogenome) and a machinery for protein biosynthesis. The expression of the mtDNA in plants is complex, particularly at the post-transcriptional level. Following transcription, the polycistronic pre-RNAs undergo extensive modifications, including trimming, splicing and editing, before being translated by organellar ribosomes. Our study focuses on N[6] -methylation of adenosine ribonucleotides (m[6] A-RNA) in plant mitochondria. m[6] A is a prevalent modification in nuclear-encoded mRNAs. The biological significance of this dynamic modification is under investigation, but it is widely accepted that m[6] A mediates structural switches that affect RNA stability and/or activity. Using m[6] A-pulldown/RNA-seq (m[6] A-RIP-seq) assays of Arabidopsis and cauliflower mitochondria, we provide information on the m[6] A-RNA landscapes in Arabidopsis thaliana and Brassica oleracea mitochondria. The results show that m[6] A targets different types of mitochondrial transcripts, including known genes, mtORFs, as well as non-coding (transcribed intergenic) RNA species. While ncRNAs undergo multiple m[6] A modifications, N[6] -methylation of adenosine residues with mRNAs seem preferably positioned near start codons and may modulate their translatability.}, }
@article {pmid31657678, year = {2020}, author = {Chigurupati, S and Vijayabalan, S and Selvarajan, KK and Aldubayan, M and Alhowail, A and Mani, V and Das, S}, title = {Antimicrobial Exploration Between Counterpart Endosymbiont and Host Plant (Tamarindus indica Linn.).}, journal = {Current pharmaceutical biotechnology}, volume = {21}, number = {5}, pages = {384-389}, doi = {10.2174/1389201020666191028105325}, pmid = {31657678}, issn = {1873-4316}, mesh = {Anti-Bacterial Agents/isolation &amp; purification/*pharmacology ; Endophytes/*isolation &amp; purification ; Gram-Negative Bacteria/drug effects ; Gram-Positive Bacteria/drug effects ; Humans ; Microbial Sensitivity Tests ; Plant Extracts/isolation &amp; purification/*pharmacology ; Plant Leaves/chemistry/microbiology ; RNA, Ribosomal, 16S ; Tamarindus/*chemistry/*microbiology ; }, abstract = {BACKGROUND: Endophytic bacteria produce various bioactive secondary metabolites, which benefit human health. Tamarindus indica L. is well known for its medicinal value in human health care. Several studies have reported on its biological effects from various parts of T. indica, but only a few studies have been devoted to examining the biological activity of endophytes of T. indica.<br><br>OBJECTIVES: In the present study, an endophyte was isolated from the leaves of T. indica and screened for its antimicrobial potential.<br><br>METHODS: The selected endophyte was identified by 16s rRNA partial genome sequencing and investigated for their antimicrobial potency. The preliminary phytochemical tests were conducted for the affirmation of phytoconstituents in the endophytic crude ethyl acetate extract of T. indica (TIM) and total phenolic content was performed. The antimicrobial potential of TIM was evaluated against human pathogenic ATCC gram-positive and gram-negative bacterial strains.<br><br>RESULTS: TIM exhibited an appreciable amount of gallic acid equivalent phenolic content (21.6 &#xb1; 0.04 mg GAE/g of crude extract). TIM showed the Minimum Inhibitory Concentration (MIC) at 250 &#x3bc;g/mL and Minimum Bactericidal Concentration (MBC) at 500 &#x3bc;g/mL among the selected human pathogenic ATCC strains. At MIC of 500 &#x3bc;g/mL, TIM displayed a significant zone of inhibition against P. aeruginosa and N. gonorrhoeae.<br><br>CONCLUSION: The results from our study highlighted for the first time the antimicrobial potential of endophytic bacterial strain Bacillus velezensis in T. indica leaves and it could be further explored as a source of natural antimicrobial agents.}, }
@article {pmid31650337, year = {2019}, author = {Chisu, V and Foxi, C and Masala, G}, title = {First molecular detection of Francisella-like endosymbionts in Hyalomma and Rhipicephalus tick species collected from vertebrate hosts from Sardinia island, Italy.}, journal = {Experimental &amp; applied acarology}, volume = {79}, number = {2}, pages = {245-254}, pmid = {31650337}, issn = {1572-9702}, mesh = {Animals ; Female ; Francisella/*classification/*isolation &amp; purification ; Italy ; Ixodidae/*microbiology ; Male ; Mammals/parasitology ; Rhipicephalus/microbiology ; }, abstract = {Ticks are vectors of a wide variety of human and animal pathogens as well as non-pathogenic microorganisms acting as endosymbionts and whose role in ticks is still little known. Symbionts such as Francisella-like endosymbionts (FLEs) are members of Francisellaceae family with unknown pathogenicity, detected in both hard and soft ticks. A total of 236 ticks collected from several sites in Sardinia were screened for Francisella species by PCR using primers targeting a fragment of the 16S rRNA gene. DNA of Francisella was detected in 5.1% (12/236) of the ticks tested. Sequencing results revealed that seven Rhipicephalus sanguineus s.l., three Hyalomma marginatum, one Hy. lusitanicum, and one Rh. bursa ticks exhibited DNA with 99-100% similarity to Francisella-like endosymbionts isolated from different tick species all over the world. Further research is needed in order to better characterize FLE strains obtained in Sardinia and to better understand if their presence could be related to the infection with other zoonotic pathogens.}, }
@article {pmid31649084, year = {2019}, author = {Gasser, MT and Chung, M and Bromley, RE and Nadendla, S and Dunning Hotopp, JC}, title = {Complete Genome Sequence of wAna, the Wolbachia Endosymbiont of Drosophila ananassae.}, journal = {Microbiology resource announcements}, volume = {8}, number = {43}, pages = {}, pmid = {31649084}, issn = {2576-098X}, support = {R01 CA206188/CA/NCI NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, abstract = {Here, we present the complete genome sequence of the Wolbachia endosymbiont wAna, isolated from Drosophila ananassae and derived from Oxford Nanopore and Illumina sequencing. We anticipate that this will aid in Wolbachia comparative genomics and the assembly of D. ananassae specifically in regions containing extensive lateral gene transfer events.}, }
@article {pmid31635285, year = {2019}, author = {Chicana, B and Couper, LI and Kwan, JY and Tahiraj, E and Swei, A}, title = {Comparative Microbiome Profiles of Sympatric Tick Species from the Far-Western United States.}, journal = {Insects}, volume = {10}, number = {10}, pages = {}, pmid = {31635285}, issn = {2075-4450}, abstract = {Insight into the composition and function of the tick microbiome has expanded considerably in recent years. Thus far, tick microbiome studies have focused on species and life stages that are responsible for transmitting disease. In this study we conducted extensive field sampling of six tick species in the far-western United States to comparatively examine the microbial composition of sympatric tick species: Ixodes pacificus, Ixodes angustus, Dermacentor variabilis, Dermacentor occidentalis, Dermacentor albipictus, and Haemaphysalis leporispalustris. These species represent both common vectors of disease and species that rarely encounter humans, exhibiting a range of host preferences and natural history. We found significant differences in microbial species diversity and composition by tick species and life stage. The microbiome of most species examined were dominated by a few primary endosymbionts. Across all species, the relative abundance of these endosymbionts increased with life stage while species richness and diversity decreased with development. Only one species, I. angustus, did not show the presence of a single dominant microbial species indicating the unique physiology of this species or its interaction with the surrounding environment. Tick species that specialize in a small number of host species or habitat ranges exhibited lower microbiome diversity, suggesting that exposure to environmental conditions or host blood meal diversity can affect the tick microbiome which in turn may affect pathogen transmission. These findings reveal important associations between ticks and their microbial community and improve our understanding of the function of non-pathogenic microbiomes in tick physiology and pathogen transmission.}, }
@article {pmid31634977, year = {2020}, author = {Liu, C and Cheng, SH and Lin, S}, title = {Illuminating the dark depths inside coral.}, journal = {Cellular microbiology}, volume = {22}, number = {1}, pages = {e13122}, doi = {10.1111/cmi.13122}, pmid = {31634977}, issn = {1462-5822}, mesh = {Animals ; Anthozoa/*physiology ; *Coral Reefs ; Dinoflagellida/physiology ; Microscopy, Fluorescence/methods ; *Symbiosis ; }, abstract = {The ability to observe in situ 3D distribution and dynamics of endosymbionts in corals is crucial for gaining a mechanistic understanding of coral bleaching and reef degradation. Here, we report the development of a tissue clearing (TC) coupled with light sheet fluorescence microscopy (LSFM) method for 3D imaging of the coral holobiont at single-cell resolution. The initial applications have demonstrated the ability of this technique to provide high spatial resolution quantitative information of endosymbiont abundance and distribution within corals. With specific fluorescent probes or assays, TC-LSFM also revealed spatial distribution and dynamics of physiological conditions (such as cell proliferation, apoptosis, and hypoxia response) in both corals and their endosymbionts. This tool is highly promising for in situ and in-depth data acquisition to illuminate coral symbiosis and health conditions in the changing marine environment, providing fundamental information for coral reef conservation and restoration.}, }
@article {pmid31632650, year = {2019}, author = {König, K and Zundel, P and Krimmer, E and König, C and Pollmann, M and Gottlieb, Y and Steidle, JLM}, title = {Reproductive isolation due to prezygotic isolation and postzygotic cytoplasmic incompatibility in parasitoid wasps.}, journal = {Ecology and evolution}, volume = {9}, number = {18}, pages = {10694-10706}, pmid = {31632650}, issn = {2045-7758}, abstract = {The reproductive barriers that prevent gene flow between closely related species are a major topic in evolutionary research. Insect clades with parasitoid lifestyle are among the most species-rich insects and new species are constantly described, indicating that speciation occurs frequently in this group. However, there are only very few studies on speciation in parasitoids. We studied reproductive barriers in two lineages of Lariophagus distinguendus (Chalcidoidea: Hymenoptera), a parasitoid wasp of pest beetle larvae that occur in human environments. One of the two lineages occurs in households preferably attacking larvae of the drugstore beetle Stegobium paniceum ("DB-lineage"), the other in grain stores with larvae of the granary weevil Sitophilus granarius as main host ("GW-lineage"). Between two populations of the DB-lineage, we identified slight sexual isolation as intraspecific barrier. Between populations from both lineages, we found almost complete sexual isolation caused by female mate choice, and postzygotic isolation, which is partially caused by cytoplasmic incompatibility induced by so far undescribed endosymbionts which are not Wolbachia or Cardinium. Because separation between the two lineages is almost complete, they should be considered as separate species according to the biological species concept. This demonstrates that cryptic species within parasitoid Hymenoptera also occur in Central Europe in close contact to humans.}, }
@article {pmid31631529, year = {2020}, author = {Bi, J and Wang, YF}, title = {The effect of the endosymbiont Wolbachia on the behavior of insect hosts.}, journal = {Insect science}, volume = {27}, number = {5}, pages = {846-858}, pmid = {31631529}, issn = {1744-7917}, mesh = {Aggression ; Animals ; *Behavior, Animal ; Feeding Behavior ; Insecta/*microbiology/*physiology ; Learning ; Memory ; Sexual Behavior, Animal ; Sleep ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {As one of the most successful intracellular symbiotic bacteria, Wolbachia can infect many arthropods and nematodes. Wolbachia infection usually affects the reproduction of their hosts to promote their own proliferation and transmission. Currently, most of the studies focus on the mechanisms of Wolbachia interactions with host reproduction. However, in addition to distribution in the reproductive tissues, Wolbachia also infect various somatic tissues of their hosts, including the brain. This raises the potential that Wolbachia may influence some somatic processes, such as behaviors in their hosts. So far, information about the effects of Wolbachia infection on host behavior is still very limited. The present review presents the current literature on different aspects of the influence of Wolbachia on various behaviors, including sleep, learning and memory, mating, feeding and aggression in their insect hosts. We then highlight ongoing scientific efforts in the field that need addressing to advance this field, which can have significant implications for further developing Wolbachia as environmentally friendly biocontrol agents to control insect-borne diseases and agricultural pests.}, }
@article {pmid31626766, year = {2019}, author = {Radkov, AD and Chou, S}, title = {An Affair to Remember: How an Endosymbiont Partners with Its Host to Build a Cell Envelope.}, journal = {Cell}, volume = {179}, number = {3}, pages = {584-586}, doi = {10.1016/j.cell.2019.09.024}, pmid = {31626766}, issn = {1097-4172}, mesh = {Animals ; Cell Wall ; Insecta ; *Peptidoglycan ; Phylogeny ; *Symbiosis ; }, abstract = {Studying endosymbionts gives us insight into early cellular mechanisms that led to the emergence of eukaryotic organelles. In this issue of Cell, Bublitz et al. (2019) report on how a nested bacterial endosymbiont of mealybugs builds its cell wall peptidoglycan through a biosynthetic pathway that is dependent on transported host enzymes.}, }
@article {pmid31624345, year = {2020}, author = {Manzano-Marı N, A and Coeur d'acier, A and Clamens, AL and Orvain, C and Cruaud, C and Barbe, V and Jousselin, E}, title = {Serial horizontal transfer of vitamin-biosynthetic genes enables the establishment of new nutritional symbionts in aphids' di-symbiotic systems.}, journal = {The ISME journal}, volume = {14}, number = {1}, pages = {259-273}, pmid = {31624345}, issn = {1751-7370}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*genetics ; Erwinia/*genetics ; *Gene Transfer, Horizontal ; Symbiosis/*genetics ; Vitamins/biosynthesis ; }, abstract = {Many insects depend on obligate mutualistic bacteria to provide essential nutrients lacking from their diet. Most aphids, whose diet consists of phloem, rely on the bacterial endosymbiont Buchnera aphidicola to supply essential amino acids and B vitamins. However, in some aphid species, provision of these nutrients is partitioned between Buchnera and a younger bacterial partner, whose identity varies across aphid lineages. Little is known about the origin and the evolutionary stability of these di-symbiotic systems. It is also unclear whether the novel symbionts merely compensate for losses in Buchnera or carry new nutritional functions. Using whole-genome endosymbiont sequences of nine Cinara aphids that harbour an Erwinia-related symbiont to complement Buchnera, we show that the Erwinia association arose from a single event of symbiont lifestyle shift, from a free-living to an obligate intracellular one. This event resulted in drastic genome reduction, long-term genome stasis, and co-divergence with aphids. Fluorescence in situ hybridisation reveals that Erwinia inhabits its own bacteriocytes near Buchnera's. Altogether these results depict a scenario for the establishment of Erwinia as an obligate symbiont that mirrors Buchnera's. Additionally, we found that the Erwinia vitamin-biosynthetic genes not only compensate for Buchnera's deficiencies, but also provide a new nutritional function; whose genes have been horizontally acquired from a Sodalis-related bacterium. A subset of these genes have been subsequently transferred to a new Hamiltonella co-obligate symbiont in one specific Cinara lineage. These results show that the establishment and dynamics of multi-partner endosymbioses can be mediated by lateral gene transfers between co-ocurring symbionts.}, }
@article {pmid31622546, year = {2020}, author = {Galis, F and van Alphen, JJM}, title = {Parthenogenesis and developmental constraints.}, journal = {Evolution &amp; development}, volume = {22}, number = {1-2}, pages = {205-217}, doi = {10.1111/ede.12324}, pmid = {31622546}, issn = {1525-142X}, mesh = {Animals ; *Biological Evolution ; Invertebrates/*growth &amp; development ; *Parthenogenesis ; Vertebrates/*growth &amp; development ; }, abstract = {The absence of a paternal contribution in an unfertilized ovum presents two developmental constraints against the evolution of parthenogenesis. We discuss the constraint caused by the absence of a centrosome and the one caused by the missing set of chromosomes and how they have been broken in specific taxa. They are examples of only a few well-underpinned examples of developmental constraints acting at macro-evolutionary scales in animals. Breaking of the constraint of the missing chromosomes is the best understood and generally involves rare occasions of drastic changes of meiosis. These drastic changes can be best explained by having been induced, or at least facilitated, by sudden cytological events (e.g., repeated rounds of hybridization, endosymbiont infections, and contagious infections). Once the genetic and developmental machinery is in place for regular or obligate parthenogenesis, shifts to other types of parthenogenesis can apparently rather easily evolve, for example, from facultative to obligate parthenogenesis, or from pseudoarrhenotoky to haplodiploidy. We argue that the combination of the two developmental constraints forms a near-absolute barrier against the gradual evolution from sporadic to obligate or regular facultative parthenogenesis, which can probably explain why the occurrence of the highly advantageous mode of regular facultative parthenogenesis is so rare and entirely absent in vertebrates.}, }
@article {pmid31621296, year = {2019}, author = {Aoyagi, S and Kodama, Y and Passarelli, MK and Vorng, JL and Kawashima, T and Yoshikiyo, K and Yamamoto, T and Gilmore, IS}, title = {OrbiSIMS Imaging Identifies Molecular Constituents of the Perialgal Vacuole Membrane of Paramecium bursaria with Symbiotic Chlorella variabilis.}, journal = {Analytical chemistry}, volume = {91}, number = {22}, pages = {14545-14551}, doi = {10.1021/acs.analchem.9b03571}, pmid = {31621296}, issn = {1520-6882}, mesh = {Chlorella/*chemistry ; Intracellular Membranes/*chemistry ; Mass Spectrometry ; Oligosaccharides/analysis ; Paramecium/*chemistry ; Symbiosis/physiology ; Vacuoles/*chemistry ; }, abstract = {The protist (mostly single-celled organisms), Paramecium bursaria, forms an intracellular symbiotic relationship with the single-celled algae, Chlorella variabilis, where P. bursaria provides nutrients (i.e., Ca[2+], Mg[2+], and K[+]), carbon dioxide for photosynthesis and protection from viruses, while C. variabilis provides oxygen, carbon fixation, and nutrients. Key to this successful relationship is the perialgal vacuole (PV) membrane, which surrounds C. variabilis and protects it from digestion by P. bursaria. The membrane is fragile and difficult to analyze using conventional methods therefore very little is known about the molecular composition. We used the OrbiSIMS, a new high-resolution mass spectrometer with subcellular resolution imaging, to study the compartmentalization of endosymbionts and elucidate biomolecular interactions between the host and endosymbiont. Ions from the region of interest, close to C. variabilis, and specific to the target samples containing PVs were found based on the chemical mapping and masses of the ions. We show chemical localizations of oligosaccharides in close proximity of C. variabilis endosymbionts in P. bursaria. These oligosaccharides are detected in host-endosymbiont samples containing PV membrane-bound algae and absent in free-living algae and digestive vacuole (DV) membrane-bound algae in P. bursaria.}, }
@article {pmid31617302, year = {2020}, author = {Biwot, JC and Zhang, HB and Liu, C and Qiao, JX and Yu, XQ and Wang, YF}, title = {Wolbachia-induced expression of kenny gene in testes affects male fertility in Drosophila melanogaster.}, journal = {Insect science}, volume = {27}, number = {5}, pages = {869-882}, doi = {10.1111/1744-7917.12730}, pmid = {31617302}, issn = {1744-7917}, mesh = {Animals ; Drosophila Proteins/*genetics/metabolism ; Drosophila melanogaster/genetics/microbiology/*physiology ; Fertility/*genetics ; Gene Expression ; I-kappa B Kinase/*genetics/metabolism ; Male ; Testis/metabolism ; *Up-Regulation ; Wolbachia/*physiology ; }, abstract = {Wolbachia are Gram-negative endosymbionts that are known to cause embryonic lethality when infected male insects mate with uninfected females or with females carrying a different strain of Wolbachia, a situation characterized as cytoplasmic incompatibility (CI). However, the mechanism of CI is not yet fully understood, although recent studies on Drosophila melanogaster have achieved great progress. Here, we found that Wolbachia infection caused changes in the expressions of several immunity-related genes, including significant upregulation of kenny (key), in the testes of D. melanogaster. Overexpression of key in fly testes led to a significant decrease in egg hatch rates when these flies mate with wild-type females. Wolbachia-infected females could rescue this embryonic lethality. Furthermore, in key overexpressing testes terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling signal was significantly stronger than in the control testes, and the level of reactive oxygen species was significantly increased. Overexpression of key also resulted in alterations of some other immunity-related gene expressions, including the downregulation of Zn72D. Knockdown of Zn72D in fly testes also led to a significant decrease in egg hatch rates. These results suggest that Wolbachia might induce the defect in male host fertility by immunity-related pathways and thus cause an oxidative damage and cell death in male testes.}, }
@article {pmid31615544, year = {2019}, author = {Ghosh, A and Jasperson, D and Cohnstaedt, LW and Brelsfoard, CL}, title = {Transfection of Culicoides sonorensis biting midge cell lines with Wolbachia pipientis.}, journal = {Parasites &amp; vectors}, volume = {12}, number = {1}, pages = {483}, pmid = {31615544}, issn = {1756-3305}, mesh = {Aedes/cytology ; Animals ; Biological Control Agents ; Cell Line/microbiology ; Ceratopogonidae/immunology/*microbiology ; Immunity/genetics ; In Situ Hybridization, Fluorescence ; Insect Vectors/immunology/*microbiology ; Pest Control, Biological/methods ; Phenotype ; Polymerase Chain Reaction ; Real-Time Polymerase Chain Reaction ; Reproduction ; Transfection/*methods ; Wolbachia/genetics/immunology/*pathogenicity ; }, abstract = {BACKGROUND: Biting midges of the genus Culicoides vector multiple veterinary pathogens and are difficult to control. Endosymbionts particularly Wolbachia pipientis may offer an alternative to control populations of Culicoides and/or impact disease transmission in the form of population suppression or replacement strategies.<br><br>METHODS: Culicoides sonorensis cell lines were transfected with a Wolbachia infection using a modified shell vial technique. Infections were confirmed using PCR and cell localization using fluorescent in situ hybridization (FISH). The stability of Wolbachia infections and density was determined by qPCR. qPCR was also used to examine immune genes in the IMD, Toll and JACK/STAT pathways to determine if Wolbachia were associated with an immune response in infected cells.<br><br>RESULTS: Here we have transfected two Culicoides sonorensis cell lines (W3 and W8) with a Wolbachia infection (walbB) from donor Aedes albopictus Aa23 cells. PCR and FISH showed the presence of Wolbachia infections in both C. sonorensis cell lines. Infection densities were higher in the W8 cell lines when compared to W3. In stably infected cells, genes in the immune Toll, IMD and JAK/STAT pathways were upregulated, along with Attacin and an Attacin-like anti-microbial peptides.<br><br>CONCLUSIONS: The successful introduction of Wolbachia infections in C. sonorensis cell lines and the upregulation of immune genes, suggest the utility of using Wolbachia for a population replacement and/or population suppression approach to limit the transmission of C. sonorensis vectored diseases. Results support the further investigation of Wolbachia induced pathogen inhibitory effects in Wolbachia-infected C. sonorensis cell lines and the introduction of Wolbachia into C. sonorensis adults via embryonic microinjection to examine for reproductive phenotypes and host fitness effects of a novel Wolbachia infection.}, }
@article {pmid31615401, year = {2019}, author = {Liang, Z and Liu, F and Wang, W and Zhang, P and Sun, X and Wang, F and Kell, H}, title = {High-throughput sequencing revealed differences of microbial community structure and diversity between healthy and diseased Caulerpa lentillifera.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {225}, pmid = {31615401}, issn = {1471-2180}, mesh = {Bacteria/*classification/genetics/isolation &amp; purification ; Biodiversity ; Caulerpa/growth &amp; development/*microbiology/parasitology ; Chlorophyta/*classification/genetics ; DNA, Intergenic ; DNA, Ribosomal/genetics ; Diatoms/*classification/genetics/isolation &amp; purification ; High-Throughput Nucleotide Sequencing/*methods ; Japan ; Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Vietnam ; }, abstract = {BACKGROUND: Caulerpa lentillifera is one of the most important economic green macroalgae in the world. Increasing demand for consumption has led to the commercial cultivation of C. lentillifera in Japan and Vietnam in recent decades. Concomitant with the increase of C. lentillifera cultivation is a rise in disease. We hypothesise that epiphytes or other microorganisms outbreak at the C. lentillifera farm may be an important factor contributing to disease in C. lentillifera. The main aims are obtaining differences in the microbial community structure and diversity between healthy and diseased C. lentillifera and key epiphytes and other microorganisms affecting the differences through the results of high-throughput sequencing and bioinformatics analysis in the present study.<br><br>RESULTS: A total of 14,050, 2479, and 941 operational taxonomic units (OTUs) were obtained from all samples using 16S rDNA, 18S rDNA, and internal transcribed spacer (ITS) high-throughput sequencing, respectively. 16S rDNA sequencing and 18S rDNA sequencing showed that microbial community diversity was higher in diseased C. lentillifera than in healthy C. lentillifera. Both PCoA results and UPGMA results indicated that the healthy and diseased algae samples have characteristically different microbial communities. The predominant prokaryotic phyla were Proteobacteria, Planctomycetes, Bacteroidetes, Cyanobacteria, Acidobacteria, Acidobacteria and Parcubacteria in all sequences. Chlorophyta was the most abundant eukaryotic phylum followed by Bacillariophyta based on 18S rDNA sequencing. Ascomycota was the dominant fungal phylum detected in healthy C. lentillifera based on ITS sequencing, whereas fungi was rare in diseased C. lentillifera, suggesting that Ascomycota was probably fungal endosymbiont in healthy C. lentillifera. There was a significantly higher abundance of Bacteroidetes, Cyanobacteria, Bacillariophyta, Ulvales and Tetraselmis in diseased C. lentillifera than in healthy C. lentillifera. Disease outbreaks significantly change carbohydrate metabolism, environmental information processing and genetic information processing of prokaryotic communities in C. lentillifera through predicted functional analyses using the Tax4Fun tool.<br><br>CONCLUSIONS: Bacteroidetes, Cyanobacteria, Bacillariophyta, Ulvales and Tetraselmis outbreak at the C. lentillifera farm sites was an important factor contributing to disease in C. lentillifera.}, }
@article {pmid31608107, year = {2019}, author = {Chiodi, A and Comandatore, F and Sassera, D and Petroni, G and Bandi, C and Brilli, M}, title = {SeqDeχ: A Sequence Deconvolution Tool for Genome Separation of Endosymbionts From Mixed Sequencing Samples.}, journal = {Frontiers in genetics}, volume = {10}, number = {}, pages = {853}, pmid = {31608107}, issn = {1664-8021}, abstract = {In recent years, the advent of NGS technology has made genome sequencing much cheaper than in the past; the high parallelization capability and the possibility to sequence more than one organism at once have opened the door to processing whole symbiotic consortia. However, this approach needs the development of specific bioinformatics tools able to analyze these data. In this work, we describe SeqDex, a tool that starts from a preliminary assembly obtained from sequencing a mixture of DNA from different organisms, to identify the contigs coming from one organism of interest. SeqDex is a fully automated machine learning-based tool exploiting partial taxonomic affiliations and compositional analysis to predict the taxonomic affiliations of contigs in an assembly. In literature, there are few methods able to deconvolve host-symbiont datasets, and most of them heavily rely on user curation and are therefore time consuming. The problem has strong similarities with metagenomic studies, where mixed samples are sequenced and the bioinformatics challenge is trying to separate contigs on the basis of their source organism; however, in symbiotic systems, additional information can be exploited to improve the output. To assess the ability of SeqDex to deconvolve host-symbiont datasets, we compared it to state-of-the-art methods for metagenomic binning and for host-symbiont deconvolution on three study cases. The results point out the good performances of the presented tool that, in addition to the ease of use and customization potential, make SeqDex a useful tool for rapid identification of endosymbiont sequences.}, }
@article {pmid31608043, year = {2019}, author = {Gifford, I and Vance, S and Nguyen, G and Berry, AM}, title = {A Stable Genetic Transformation System and Implications of the Type IV Restriction System in the Nitrogen-Fixing Plant Endosymbiont Frankia alni ACN14a.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {2230}, pmid = {31608043}, issn = {1664-302X}, abstract = {Genus Frankia is comprised primarily of nitrogen-fixing actinobacteria that form root nodule symbioses with a group of hosts known as the actinorhizal plants. These plants are evolutionarily closely related to the legumes that are nodulated by the rhizobia. Both host groups utilize homologs of nodulation genes for root-nodule symbiosis, derived from common plant ancestors. The corresponding endosymbionts, Frankia and the rhizobia, however, are distantly related groups of bacteria, leading to questions about their symbiotic mechanisms and evolutionary history. To date, a stable system of electrotransformation has been lacking in Frankia despite numerous attempts by research groups worldwide. We have identified type IV methyl-directed restriction systems, highly-expressed in a range of actinobacteria, as a likely barrier to Frankia transformation. Here we report the successful electrotransformation of the model strain F. alni ACN14a with an unmethylated, broad host-range replicating plasmid, expressing chloramphenicol-resistance for selection and GFP as a marker of gene expression. This system circumvented the type IV restriction barrier and allowed the stable maintenance of the plasmid. During nitrogen limitation, Frankia differentiates into two cell types: the vegetative hyphae and nitrogen-fixing vesicles. When the expression of egfp under the control of the nif gene cluster promoter was localized using fluorescence imaging, the expression of nitrogen fixation in nitrogen-limited culture was localized in Frankia vesicles but not in hyphae. The ability to separate gene expression patterns between Frankia hyphae and vesicles will enable deeper comparisons of molecular signaling and metabolic exchange between Frankia-actinorhizal and rhizobia-legume symbioses to be made, and may broaden potential applications in agriculture. Further downstream applications are possible, including gene knock-outs and complementation, to open up a range of experiments in Frankia and its symbioses. Additionally, in the transcriptome of F. alni ACN14a, type IV restriction enzymes were highly expressed in nitrogen-replete culture but their expression strongly decreased during symbiosis. The down-regulation of type IV restriction enzymes in symbiosis suggests that horizontal gene transfer may occur more frequently inside the nodule, with possible new implications for the evolution of Frankia.}, }
@article {pmid31608037, year = {2019}, author = {Antoine, R and Rivera-Millot, A and Roy, G and Jacob-Dubuisson, F}, title = {Relationships Between Copper-Related Proteomes and Lifestyles in β Proteobacteria.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {2217}, pmid = {31608037}, issn = {1664-302X}, abstract = {Copper is an essential transition metal whose redox properties are used for a variety of enzymatic oxido-reductions and in electron transfer chains. It is also toxic to living beings, and therefore its cellular concentration must be strictly controlled. We have performed in silico analyses of the predicted proteomes of more than one hundred species of β proteobacteria to characterize their copper-related proteomes, including cuproproteins, i.e., proteins with active-site copper ions, copper chaperones, and copper-homeostasis systems. Copper-related proteomes represent between 0 and 1.48% of the total proteomes of β proteobacteria. The numbers of cuproproteins are globally proportional to the proteome sizes in all phylogenetic groups and strongly linked to aerobic respiration. In contrast, environmental bacteria have considerably larger proportions of copper-homeostasis systems than the other groups of bacteria, irrespective of their proteome sizes. Evolution toward commensalism, obligate, host-restricted pathogenesis or symbiosis is globally reflected in the loss of copper-homeostasis systems. In endosymbionts, defense systems and copper chaperones have disappeared, whereas residual cuproenzymes are electron transfer proteins for aerobic respiration. Lifestyle is thus a major determinant of the size and composition of the copper-related proteome, and it is particularly reflected in systems involved in copper homeostasis. Analyses of the copper-related proteomes of a number of species belonging to the Burkholderia, Bordetella, and Neisseria genera indicates that commensals are in the process of shedding their copper-homeostasis systems and chaperones to greater extents yet than pathogens.}, }
@article {pmid31603613, year = {2020}, author = {Caputo, B and Moretti, R and Manica, M and Serini, P and Lampazzi, E and Bonanni, M and Fabbri, G and Pichler, V and Della Torre, A and Calvitti, M}, title = {A bacterium against the tiger: preliminary evidence of fertility reduction after release of Aedes albopictus males with manipulated Wolbachia infection in an Italian urban area.}, journal = {Pest management science}, volume = {76}, number = {4}, pages = {1324-1332}, doi = {10.1002/ps.5643}, pmid = {31603613}, issn = {1526-4998}, mesh = {*Aedes ; Animals ; Female ; Fertility ; Italy ; Male ; Mosquito Control ; *Wolbachia ; }, abstract = {BACKGROUND: Novel tools are needed to reduce the nuisance and risk of exotic arbovirus transmission associated with the colonization of temperate regions by Aedes albopictus. The incompatible insect technique (IIT) is a population suppression approach based on cytoplasmic incompatibility between males with manipulated endosymbionts and wild females. Here, we present the results of the first field experiment in Europe to assess the capacity of an Ae. albopictus line (ARwP) deprived of its natural endosymbiont Wolbachia and transinfected with a Wolbachia strain from the mosquito Culex pipiens, to sterilize wild females.<br><br>RESULTS: We released &#x223c;&#x2009;4500 ARwP males weekly for 6&#x2009;weeks in a green area within urban Rome (Italy) and carried out egg (N&#xa0;=&#x2009;13&#x2009;442), female (N&#xa0;=&#x2009;128) and male (N&#xa0;=&#x2009;352) collections. Egg (N&#xa0;=&#x2009;13&#x2009;783) and female (N&#xa0;=&#x2009;48) collections were also carried out at two untreated control sites. The percentage of viable eggs during release was, on average, significantly lower in treated sites than in control sites, with the greatest difference (16%) seen after the fourth release. The ARwP to wild male ratio in the release spots between day&#xa0;3 after the first ARwP male release and day 7 after the last release was, on average, 7:10. Released males survived up to 2&#x2009;weeks. Approximately 30% of females collected in the release spots showed 100% sterility and 20% showed strongly reduced fertility compared with control sites.<br><br>CONCLUSIONS: Results support the potential of IIT as a tool contributing to Ae. albopictus control in the urban context, and stress the need for larger field trials to evaluate the cost-efficacy of the approach in suppressing wild populations. &#xa9; 2019 Society of Chemical Industry.}, }
@article {pmid31603571, year = {2020}, author = {Obert, T and Vďačný, P}, title = {Evolutionary Origin and Host Range of Plagiotoma lumbrici (Ciliophora, Hypotrichia), an Obligate Gut Symbiont of Lumbricid Earthworms.}, journal = {The Journal of eukaryotic microbiology}, volume = {67}, number = {2}, pages = {176-189}, doi = {10.1111/jeu.12768}, pmid = {31603571}, issn = {1550-7408}, mesh = {Animals ; Gastrointestinal Tract/parasitology ; Host Specificity ; Hypotrichida/*classification/genetics/physiology ; Oligochaeta/*parasitology ; Phylogeny ; RNA, Protozoan/analysis ; RNA, Ribosomal, 18S/analysis ; RNA, Ribosomal, 28S/analysis ; *Symbiosis ; }, abstract = {Four common earthworm species, the anecic Lumbricus terrestris, the endogeic Octolasion tyrteum as well as the epigeic Eisenia fetida and Dendrobaena veneta, were examined for the presence of the microbial gut symbiont Plagiotoma lumbrici. The evolutionary origin of this endobiotic microbe was reconstructed, using the 18S rRNA gene, the ITS1-5.8S-ITS2 region, and the first two domains of the 28S rRNA gene. Plagiotoma lumbrici was exclusively detected in the anecic Lumbricus terrestris. Multigene analyses and the ITS2 secondary structure robustly determined the phylogenetic home of Plagiotoma lumbrici populations within the oxytrichid Dorsomarginalia (Spirotrichea: Hypotrichia) as a sister taxon of the free-living Hemiurosomoida longa. This indicates that earthworms obtained their gut endosymbiont by ingesting soil/leaf litter containing oxytrichine ciliates that became adapted to the intestinal tract of earthworms. Interestingly, according to the literature data, Plagiotoma lumbrici was detected in multiple anecic and some epigeic but never in endogeic earthworms. These observations suggest that Plagiotoma lumbrici might be adapted to certain gut conditions and the lifestyle of anecic Lumbricidae, such as Lumbricus, Aporrectodea, and Scherotheca, as well as of some co-occurring epigeic Lumbricus species.}, }
@article {pmid31600190, year = {2019}, author = {Becking, T and Chebbi, MA and Giraud, I and Moumen, B and Laverré, T and Caubet, Y and Peccoud, J and Gilbert, C and Cordaux, R}, title = {Sex chromosomes control vertical transmission of feminizing Wolbachia symbionts in an isopod.}, journal = {PLoS biology}, volume = {17}, number = {10}, pages = {e3000438}, pmid = {31600190}, issn = {1545-7885}, mesh = {Alleles ; Animals ; Female ; Genotype ; Homozygote ; Isopoda/*genetics/microbiology ; Male ; Models, Genetic ; Quantitative Trait, Heritable ; *Sex Chromosomes ; *Sex Determination Processes ; Sex Ratio ; Symbiosis/*genetics ; Wolbachia/*physiology ; }, abstract = {Microbial endosymbiosis is widespread in animals, with major ecological and evolutionary implications. Successful symbiosis relies on efficient vertical transmission through host generations. However, when symbionts negatively affect host fitness, hosts are expected to evolve suppression of symbiont effects or transmission. Here, we show that sex chromosomes control vertical transmission of feminizing Wolbachia endosymbionts in the isopod Armadillidium nasatum. Theory predicts that the invasion of an XY/XX species by cytoplasmic sex ratio distorters is unlikely because it leads to fixation of the unusual (and often lethal or infertile) YY genotype. We demonstrate that A. nasatum X and Y sex chromosomes are genetically highly similar and that YY individuals are viable and fertile, thereby enabling Wolbachia spread in this XY-XX species. Nevertheless, we show that Wolbachia cannot drive fixation of YY individuals, because infected YY females do not transmit Wolbachia to their offspring, unlike XX and XY females. The genetic basis fits the model of a Y-linked recessive allele (associated with an X-linked dominant allele), in which the homozygous state suppresses Wolbachia transmission. Moreover, production of all-male progenies by infected YY females restores a balanced sex ratio at the host population level. This suggests that blocking of Wolbachia transmission by YY females may have evolved to suppress feminization, thereby offering a whole new perspective on the evolutionary interplay between microbial symbionts and host sex chromosomes.}, }
@article {pmid31600008, year = {2020}, author = {Bondarenko, N and Volkova, E and Masharsky, A and Kudryavtsev, A and Smirnov, A}, title = {A Comparative Characterization of the Mitochondrial Genomes of Paramoeba aparasomata and Neoparamoeba pemaquidensis (Amoebozoa, Paramoebidae).}, journal = {The Journal of eukaryotic microbiology}, volume = {67}, number = {2}, pages = {167-175}, doi = {10.1111/jeu.12767}, pmid = {31600008}, issn = {1550-7408}, mesh = {*Genome, Mitochondrial ; *Genome, Protozoan ; Lobosea/*genetics ; Protein Structure, Secondary ; Protozoan Proteins/chemistry ; }, abstract = {Marine amebae of the genus Paramoeba (Amoebozoa, Dactylopodida) normally contain a eukaryotic endosymbiont known as Perkinsela-like organism (PLO). This is one of the characters to distinguish the genera Neoparamoeba and Paramoeba from other Dactylopodida. It is known that the PLO may be lost, but PLO-free strains of paramoebians were never available for molecular studies. Recently, we have described the first species of the genus Paramoeba which has no parasome-Paramoeba aparasomata. In this study, we present a mitochondrial genome of this species, compare it with that of Neoparamoeba pemaquidensis, and analyze the evolutionary dynamics of gene sequences and gene order rearrangements between these species. The mitochondrial genome of P. aparasomata is 46,254 bp long and contains a set of 31 protein-coding genes, 19 tRNAs, two rRNA genes, and 7 open reading frames. Our results suggest that these two mitochondrial genomes within the genus Paramoeba have rather similar organization and gene order, base composition, codon usage, the composition and structure of noncoding, and overlapping regions.}, }
@article {pmid31596993, year = {2019}, author = {Walker, NS and Fernández, R and Sneed, JM and Paul, VJ and Giribet, G and Combosch, DJ}, title = {Differential gene expression during substrate probing in larvae of the Caribbean coral Porites astreoides.}, journal = {Molecular ecology}, volume = {28}, number = {22}, pages = {4899-4913}, pmid = {31596993}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*genetics ; Caribbean Region ; Coral Reefs ; Dinoflagellida/genetics ; Gene Expression/*genetics ; Larva/*genetics ; Symbiosis/genetics ; Transcriptome/genetics ; }, abstract = {The transition from larva to adult is a critical step in the life history strategy of most marine animals. However, the genetic basis of this life history change remains poorly understood in many taxa, including most coral species. Recent evidence suggests that coral planula larvae undergo significant changes at the physiological and molecular levels throughout the development. To investigate this, we characterized differential gene expression (DGE) during the transition from planula to adult polyp in the abundant Caribbean reef-building coral Porites astreoides, that is from nonprobing to actively substrate-probing larva, a stage required for colony initiation. This period is crucial for the coral, because it demonstrates preparedness to locate appropriate substrata for settlement based on vital environmental cues. Through RNA-Seq, we identified 860 differentially expressed holobiont genes between probing and nonprobing larvae (p ≤ .01), the majority of which were upregulated in probing larvae. Surprisingly, differentially expressed genes of endosymbiotic dinoflagellate origin greatly outnumbered coral genes, compared with a nearly 1:1 ratio of coral-to-dinoflagellate gene representation in the holobiont transcriptome. This unanticipated result suggests that dinoflagellate endosymbionts may play a significant role in the transition from nonprobing to probing behaviour in dinoflagellate-rich larvae. Putative holobiont genes were largely involved in protein and nucleotide binding, metabolism and transport. Genes were also linked to environmental sensing and response and integral signalling pathways. Our results thus provide detailed insight into molecular changes prior to larval settlement and highlight the complex physiological and biochemical changes that occur in early transition stages from pelagic to benthic stages in corals, and perhaps more importantly, in their endosymbionts.}, }
@article {pmid31596027, year = {2020}, author = {Bing, XL and Lu, YJ and Xia, CB and Xia, X and Hong, XY}, title = {Transcriptome of Tetranychus urticae embryos reveals insights into Wolbachia-induced cytoplasmic incompatibility.}, journal = {Insect molecular biology}, volume = {29}, number = {2}, pages = {193-204}, doi = {10.1111/imb.12620}, pmid = {31596027}, issn = {1365-2583}, mesh = {Animals ; Cytoplasm ; Embryo, Nonmammalian/microbiology/physiology ; Female ; Male ; Reproduction ; Tetranychidae/embryology/growth &amp; development/microbiology/*physiology ; *Transcriptome ; Wolbachia/*physiology ; }, abstract = {The endosymbiont Wolbachia is known for manipulating host reproduction in selfish ways. However, the molecular mechanisms have not yet been investigated in embryos. Here, we found that Wolbachia had no effect on the number of deposited eggs in Tetranychus urticae Koch (Acari: Tetranychidae) but caused two types of reproductive manipulation: killing uninfected female embryos via cytoplasmic incompatibility (CI) and increasing the hatching ratio of infected female embryos. RNA sequencing analyses showed that 145 genes were differentially expressed between Wolbachia-infected (WI) and Wolbachia-uninfected (WU) embryos. Wolbachia infection down-regulated messenger RNA (mRNA) expression of glutathione S-transferase that could buffer oxidative stress. In addition, 1613 and 294 genes were identified as CI-specific up-/down-regulated genes. Compared to WU and WI embryos, embryos of CI cross strongly expressed genes involved in transcription, translation, tissue morphogenesis, DNA damage and mRNA surveillance. In contrast, most of the genes associated with energy production and metabolism were down-regulated in the CI embryos compared to the WU and WI embryos, which provides some clues as to the cause of death of CI embryos. These results identify several genes that could be candidates for explaining Wolbachia-induced CI. Our data form a basis to help elucidate the molecular consequences of CI in embryos.}, }
@article {pmid31595051, year = {2020}, author = {Yang, Y and Sun, J and Sun, Y and Kwan, YH and Wong, WC and Zhang, Y and Xu, T and Feng, D and Zhang, Y and Qiu, JW and Qian, PY}, title = {Genomic, transcriptomic, and proteomic insights into the symbiosis of deep-sea tubeworm holobionts.}, journal = {The ISME journal}, volume = {14}, number = {1}, pages = {135-150}, pmid = {31595051}, issn = {1751-7370}, mesh = {Animals ; Bacteria/*genetics/*metabolism/pathogenicity ; Carbon Cycle ; Gene Expression Profiling ; Genomics ; Hydrothermal Vents/microbiology ; Immunity, Innate/genetics ; Polychaeta/genetics/immunology/metabolism/*microbiology ; Proteomics ; *Symbiosis/genetics ; }, abstract = {Deep-sea hydrothermal vents and methane seeps are often densely populated by animals that host chemosynthetic symbiotic bacteria, but the molecular mechanisms of such host-symbiont relationship remain largely unclear. We characterized the symbiont genome of the seep-living siboglinid Paraescarpia echinospica and compared seven siboglinid-symbiont genomes. Our comparative analyses indicate that seep-living siboglinid endosymbionts have more virulence traits for establishing infections and modulating host-bacterium interaction than the vent-dwelling species, and have a high potential to resist environmental hazards. Metatranscriptome and metaproteome analyses of the Paraescarpia holobiont reveal that the symbiont is highly versatile in its energy use and efficient in carbon fixation. There is close cooperation within the holobiont in production and supply of nutrients, and the symbiont may be able to obtain nutrients from host cells using virulence factors. Moreover, the symbiont is speculated to have evolved strategies to mediate host protective immunity, resulting in weak expression of host innate immunity genes in the trophosome. Overall, our results reveal the interdependence of the tubeworm holobiont through mutual nutrient supply, a pathogen-type regulatory mechanism, and host-symbiont cooperation in energy utilization and nutrient production, which is a key adaptation allowing the tubeworm to thrive in deep-sea chemosynthetic environments.}, }
@article {pmid31587897, year = {2019}, author = {Bublitz, DC and Chadwick, GL and Magyar, JS and Sandoz, KM and Brooks, DM and Mesnage, S and Ladinsky, MS and Garber, AI and Bjorkman, PJ and Orphan, VJ and McCutcheon, JP}, title = {Peptidoglycan Production by an Insect-Bacterial Mosaic.}, journal = {Cell}, volume = {179}, number = {3}, pages = {703-712.e7}, pmid = {31587897}, issn = {1097-4172}, support = {MR/S009272/1/MRC_/Medical Research Council/United Kingdom ; P20 GM103546/GM/NIGMS NIH HHS/United States ; S10 OD021806/OD/NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics/pathogenicity ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Hemiptera/*genetics/microbiology ; Host-Pathogen Interactions ; Insect Proteins/genetics/metabolism ; Peptidoglycan/*biosynthesis/genetics ; *Symbiosis ; }, abstract = {Peptidoglycan (PG) is a defining feature of bacteria, involved in cell division, shape, and integrity. We previously reported that several genes related to PG biosynthesis were horizontally transferred from bacteria to the nuclear genome of mealybugs. Mealybugs are notable for containing a nested bacteria-within-bacterium endosymbiotic structure in specialized insect cells, where one bacterium, Moranella, lives in the cytoplasm of another bacterium, Tremblaya. Here we show that horizontally transferred genes on the mealybug genome work together with genes retained on the Moranella genome to produce a PG layer exclusively at the Moranella cell periphery. Furthermore, we show that an insect protein encoded by a horizontally transferred gene of bacterial origin is transported into the Moranella cytoplasm. These results provide a striking parallel to the genetic and biochemical mosaicism found in organelles, and prove that multiple horizontally transferred genes can become integrated into a functional pathway distributed between animal and bacterial endosymbiont genomes.}, }
@article {pmid31587649, year = {2019}, author = {Galindo, LJ and Torruella, G and Moreira, D and Eglit, Y and Simpson, AGB and Völcker, E and Clauß, S and López-García, P}, title = {Combined cultivation and single-cell approaches to the phylogenomics of nucleariid amoebae, close relatives of fungi.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1786}, pages = {20190094}, pmid = {31587649}, issn = {1471-2970}, mesh = {Eukaryota/*classification ; *Phylogeny ; Single-Cell Analysis/*methods ; }, abstract = {Nucleariid amoebae (Opisthokonta) have been known since the nineteenth century but their diversity and evolutionary history remain poorly understood. To overcome this limitation, we have obtained genomic and transcriptomic data from three Nuclearia, two Pompholyxophrys and one Lithocolla species using traditional culturing and single-cell genome (SCG) and single-cell transcriptome amplification methods. The phylogeny of the complete 18S rRNA sequences of Pompholyxophrys and Lithocolla confirmed their suggested evolutionary relatedness to nucleariid amoebae, although with moderate support for internal splits. SCG amplification techniques also led to the identification of probable bacterial endosymbionts belonging to Chlamydiales and Rickettsiales in Pompholyxophrys. To improve the phylogenetic framework of nucleariids, we carried out phylogenomic analyses based on two datasets of, respectively, 264 conserved proteins and 74 single-copy protein domains. We obtained full support for the monophyly of the nucleariid amoebae, which comprise two major clades: (i) Parvularia-Fonticula and (ii) Nuclearia with the scaled genera Pompholyxophrys and Lithocolla. Based on these findings, the evolution of some traits of the earliest-diverging lineage of Holomycota can be inferred. Our results suggest that the last common ancestor of nucleariids was a freshwater, bacterivorous, non-flagellated filose and mucilaginous amoeba. From the ancestor, two groups evolved to reach smaller (Parvularia-Fonticula) and larger (Nuclearia and related scaled genera) cell sizes, leading to different ecological specialization. The Lithocolla + Pompholyxophrys clade developed exogenous or endogenous cell coverings from a Nuclearia-like ancestor. This article is part of a discussion meeting issue 'Single cell ecology'.}, }
@article {pmid31587647, year = {2019}, author = {Tyml, T and Date, SV and Woyke, T}, title = {A single-cell genome perspective on studying intracellular associations in unicellular eukaryotes.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1786}, pages = {20190082}, pmid = {31587647}, issn = {1471-2970}, mesh = {Eukaryotic Cells/*physiology ; *Genome ; Genomics/*methods ; Single-Cell Analysis/*methods ; }, abstract = {Single-cell genomics (SCG) methods provide a unique opportunity to analyse whole genome information at the resolution of an individual cell. While SCG has been extensively used to investigate bacterial and archaeal genomes, the technique has been rarely used to access the genetic makeup of uncultivated microbial eukaryotes. In this regard, the use of SCG can provide a wealth of information; not only do the methods allow exploration of the genome, they can also help elucidate the relationship between the cell and intracellular entities extant in nearly all eukaryotes. SCG enables the study of total eukaryotic cellular DNA, which in turn allows us to better understand the evolutionary history and diversity of life, and the physiological interactions that define complex organisms. This article is part of a discussion meeting issue 'Single cell ecology'.}, }
@article {pmid31585988, year = {2019}, author = {Takeshita, K and Yamada, T and Kawahara, Y and Narihiro, T and Ito, M and Kamagata, Y and Shinzato, N}, title = {Tripartite Symbiosis of an Anaerobic Scuticociliate with Two Hydrogenosome-Associated Endosymbionts, a Holospora-Related Alphaproteobacterium and a Methanogenic Archaeon.}, journal = {Applied and environmental microbiology}, volume = {85}, number = {24}, pages = {}, pmid = {31585988}, issn = {1098-5336}, mesh = {Alphaproteobacteria/classification/genetics/isolation &amp; purification/*metabolism ; Anaerobiosis/*physiology ; Ciliophora/*microbiology ; Culture Media/chemistry ; Euryarchaeota/classification/genetics/*metabolism ; Holosporaceae/classification/genetics/*physiology ; In Situ Hybridization, Fluorescence ; Organelles/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics/isolation &amp; purification ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {A number of anaerobic ciliates, unicellular eukaryotes, intracellularly possess methanogenic archaea and bacteria as symbiotic partners. Although this tripartite relationship is of interest in terms of the fact that each participant is from a different domain, the difficulty in culture and maintenance of those host species with symbiotic partners has disturbed both ecological and functional studies so far. In this study, we obtained a stable culture of a small anaerobic scuticociliate, strain GW7. By transmission electron microscopic observation and fluorescent in situ hybridization with domain-specific probes, we demonstrate that GW7 possesses both archaeal and bacterial endosymbionts in its cytoplasm. These endosymbionts are in dependently associated with hydrogenosomes, which are organelle producing hydrogen and ATP under anaerobic conditions. Clone library analyses targeting prokaryotic 16S rRNA genes, fluorescent in situ hybridization with endosymbiont-specific probes, and molecular phylogenetic analyses revealed the phylogenetic affiliations and intracellular localizations of these endosymbionts. The endosymbiotic archaeon is a methanogen belonging to the genus Methanoregula (order Methanomicrobiales); a member of this genus has previously been described as the endosymbiont of an anaerobic ciliate from the genus Metopus (class Armophorea), which is only distantly related to strain GW7 (class Oligohymenophorea). The endosymbiotic bacterium belongs to the family Holosporaceae of the class Alphaproteobacteria, which also comprises several endosymbionts of various aerobic ciliates. For this endosymbiotic bacterium, we propose a novel candidate genus and species, "Candidatus Hydrogenosomobacter endosymbioticus."IMPORTANCE Tripartite symbioses between anaerobic ciliated protists and their intracellular archaeal and bacterial symbionts are not uncommon, but most reports have been based mainly on microscopic observations. Deeper insights into the function, ecology, and evolution of these fascinating symbioses involving partners from all three domains of life have been hampered by the difficulties of culturing anaerobic ciliates in the laboratory and the frequent loss of their prokaryotic partners during long-term cultivation. In the present study, we report the isolation of an anaerobic scuticociliate, strain GW7, which has been stably maintained in our laboratory for more than 3 years without losing either of its endosymbionts. Unexpectedly, molecular characterization of the endosymbionts revealed that the bacterial partner of GW7 is phylogenetically related to intranuclear endosymbionts of aerobic ciliates. This strain will enable future genomic, transcriptomic, and proteomic analyses of the interactions in this tripartite symbiosis and a comparison with endosymbioses in aerobic ciliates.}, }
@article {pmid31578438, year = {2019}, author = {Spicer, GLC and Eid, A and Wangpraseurt, D and Swain, TD and Winkelmann, JA and Yi, J and Kühl, M and Marcelino, LA and Backman, V}, title = {Measuring light scattering and absorption in corals with Inverse Spectroscopic Optical Coherence Tomography (ISOCT): a new tool for non-invasive monitoring.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {14148}, pmid = {31578438}, issn = {2045-2322}, mesh = {Absorption, Radiation ; Animals ; Anthozoa/chemistry/*physiology ; Coral Reefs ; Dynamic Light Scattering/methods ; Environmental Monitoring/*methods ; Tomography, Optical Coherence/*methods ; }, abstract = {The success of reef-building corals for >200 million years has been dependent on the mutualistic interaction between the coral host and its photosynthetic endosymbiont dinoflagellates (family Symbiodiniaceae) that supply the coral host with nutrients and energy for growth and calcification. While multiple light scattering in coral tissue and skeleton significantly enhance the light microenvironment for Symbiodiniaceae, the mechanisms of light propagation in tissue and skeleton remain largely unknown due to a lack of technologies to measure the intrinsic optical properties of both compartments in live corals. Here we introduce ISOCT (inverse spectroscopic optical coherence tomography), a non-invasive approach to measure optical properties and three-dimensional morphology of living corals at micron- and nano-length scales, respectively, which are involved in the control of light propagation. ISOCT enables measurements of optical properties in the visible range and thus allows for characterization of the density of light harvesting pigments in coral. We used ISOCT to characterize the optical scattering coefficient (μs) of the coral skeleton and chlorophyll a concentration of live coral tissue. ISOCT further characterized the overall micro- and nano-morphology of live tissue by measuring differences in the sub-micron spatial mass density distribution (D) that vary throughout the tissue and skeleton and give rise to light scattering, and this enabled estimates of the spatial directionality of light scattering, i.e., the anisotropy coefficient, g. Thus, ISOCT enables imaging of coral nanoscale structures and allows for quantifying light scattering and pigment absorption in live corals. ISOCT could thus be developed into an important tool for rapid, non-invasive monitoring of coral health, growth and photophysiology with unprecedented spatial resolution.}, }
@article {pmid31573138, year = {2019}, author = {McLean, AHC and Godfray, HCJ and Ellers, J and Henry, LM}, title = {Host relatedness influences the composition of aphid microbiomes.}, journal = {Environmental microbiology reports}, volume = {11}, number = {6}, pages = {808-816}, pmid = {31573138}, issn = {1758-2229}, support = {NBAF708//Natural Environment Research Council/International ; NE/M018016/1//Natural Environment Research Council/International ; VICI 865.12.003//Nederlandse Organisatie voor Wetenschappelijk Onderzoek/International ; }, mesh = {Animals ; Aphids/classification/*microbiology ; Bacteria/classification/genetics ; *Host Microbial Interactions ; Metagenomics ; *Microbiota ; }, abstract = {Animals are host to a community of microbes, collectively referred to as their microbiome, that can play a key role in their hosts' biology. The bacterial endosymbionts of insects have a particularly strong influence on their hosts, but despite their importance we still know little about the factors that influence the composition of insect microbial communities. Here, we ask: what is the relative importance of host relatedness and host ecology in structuring symbiont communities of diverse aphid species? We used next-generation sequencing to compare the microbiomes of 46 aphid species with known host plant affiliations. We find that relatedness between aphid species is the key factor explaining the microbiome composition, with more closely related aphid species housing more similar bacterial communities. Endosymbionts dominate the microbial communities, and we find a novel bacterium in the genus Sphingopyxis that is associated with numerous aphid species feeding exclusively on trees. The influence of ecology was less pronounced than that of host relatedness. Our results suggest that co-adaptation between insect species and their facultative symbionts is a more important determinant of symbiont species presence in aphids than shared ecology of hosts.}, }
@article {pmid31568486, year = {2019}, author = {Voronin, D and Schnall, E and Grote, A and Jawahar, S and Ali, W and Unnasch, TR and Ghedin, E and Lustigman, S}, title = {Pyruvate produced by Brugia spp. via glycolysis is essential for maintaining the mutualistic association between the parasite and its endosymbiont, Wolbachia.}, journal = {PLoS pathogens}, volume = {15}, number = {9}, pages = {e1008085}, pmid = {31568486}, issn = {1553-7374}, support = {R56 AI118936/AI/NIAID NIH HHS/United States ; T32 AI007180/AI/NIAID NIH HHS/United States ; F31 AI131527/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia/genetics/*metabolism/*microbiology ; Brugia malayi/genetics/metabolism/microbiology ; Brugia pahangi/genetics/metabolism/microbiology ; Female ; Filariasis/metabolism/microbiology/parasitology ; Genes, Helminth ; Glycolysis ; Host Microbial Interactions ; Host-Parasite Interactions ; Humans ; Male ; Pyruvic Acid/*metabolism ; Symbiosis ; Wolbachia/genetics/*metabolism ; }, abstract = {Human parasitic nematodes are the causative agents of lymphatic filariasis (elephantiasis) and onchocerciasis (river blindness), diseases that are endemic to more than 80 countries and that consistently rank in the top ten for the highest number of years lived with disability. These filarial nematodes have evolved an obligate mutualistic association with an intracellular bacterium, Wolbachia, a symbiont that is essential for the successful development, reproduction, and survival of adult filarial worms. Elimination of the bacteria causes adult worms to die, making Wolbachia a primary target for developing new interventional tools to combat filariases. To further explore Wolbachia as a promising indirect macrofilaricidal drug target, the essential cellular processes that define the symbiotic Wolbachia-host interactions need to be identified. Genomic analyses revealed that while filarial nematodes encode all the enzymes necessary for glycolysis, Wolbachia does not encode the genes for three glycolytic enzymes: hexokinase, 6-phosphofructokinase, and pyruvate kinase. These enzymes are necessary for converting glucose into pyruvate. Wolbachia, however, has the full complement of genes required for gluconeogenesis starting with pyruvate, and for energy metabolism via the tricarboxylic acid cycle. Therefore, we hypothesized that Wolbachia might depend on host glycolysis to maintain a mutualistic association with their parasitic host. We did conditional experiments in vitro that confirmed that glycolysis and its end-product, pyruvate, sustain this symbiotic relationship. Analysis of alternative sources of pyruvate within the worm indicated that the filarial lactate dehydrogenase could also regulate the local intracellular concentration of pyruvate in proximity to Wolbachia and thus help control bacterial growth via molecular interactions with the bacteria. Lastly, we have shown that the parasite's pyruvate kinase, the enzyme that performs the last step in glycolysis, could be a potential novel anti-filarial drug target. Establishing that glycolysis is an essential component of symbiosis in filarial worms could have a broader impact on research focused on other intracellular bacteria-host interactions where the role of glycolysis in supporting intracellular survival of bacteria has been reported.}, }
@article {pmid31568480, year = {2019}, author = {Gawande, SJ and Anandhan, S and Ingle, A and Roylawar, P and Khandagale, K and Gawai, T and Jacobson, A and Asokan, R and Singh, M}, title = {Microbiome profiling of the onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae).}, journal = {PloS one}, volume = {14}, number = {9}, pages = {e0223281}, pmid = {31568480}, issn = {1932-6203}, mesh = {Actinobacteria/classification/*genetics/isolation &amp; purification ; Animals ; Bacterial Typing Techniques ; Bacteroidetes/classification/*genetics/isolation &amp; purification ; Cyanobacteria/classification/*genetics/isolation &amp; purification ; Firmicutes/classification/*genetics/isolation &amp; purification ; Gastrointestinal Microbiome/*genetics ; Genetic Variation ; India ; Phylogeny ; Proteobacteria/classification/*genetics/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Symbiosis/genetics ; Thysanoptera/*microbiology ; Tobacco/parasitology ; Wolbachia/classification/genetics/isolation &amp; purification ; }, abstract = {The gut microbial community structure of adult Thrips tabaci collected from 10 different agro-climatically diverse locations of India was characterized by using the Illumina MiSeq platform to amplify the V3 region of the 16S rRNA gene of bacteria present in the sampled insects. Analyses were performed to study the bacterial communities associated with Thrips tabaci in India. The complete bacterial metagenome of T. tabaci was comprised of 1662 OTUs of which 62.25% belong to known and 37.7% of unidentified/unknown bacteria. These OTUs constituted 21 bacterial phyla of 276 identified genera. Phylum Proteobacteria was predominant, followed by Actinobacteria, Firmicutes, Bacteroidetes and Cyanobacteria. Additionally, the occurrence of the reproductive endosymbiont, Wolbachia was detected at two locations (0.56%) of the total known OTUs. There is high variation in diversity and species richness among the different locations. Alpha-diversity metrics indicated the higher gut bacterial diversity at Bangalore and lowest at Rahuri whereas higher bacterial species richness at T. tabaci samples from Imphal and lowest at Jhalawar. Beta diversity analyses comparing bacterial communities between the samples showed distinct differences in bacterial community composition of T. tabaci samples from different locations. This paper also constitutes the first record of detailed bacterial communities associated with T. tabaci. The location-wise variation in microbial metagenome profile of T. tabaci suggests that bacterial diversity might be governed by its population genetic structure, environment and habitat.}, }
@article {pmid31566662, year = {2019}, author = {Detcharoen, M and Arthofer, W and Schlick-Steiner, BC and Steiner, FM}, title = {Wolbachia megadiversity: 99% of these microorganismic manipulators unknown.}, journal = {FEMS microbiology ecology}, volume = {95}, number = {11}, pages = {}, doi = {10.1093/femsec/fiz151}, pmid = {31566662}, issn = {1574-6941}, mesh = {Animals ; Arthropods/microbiology ; *Biodiversity ; Ecosystem ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {Wolbachia (Alphaproteobacteria) are the most widespread endosymbionts of arthropods, manipulating their hosts by various means to maximize the number of host individuals infected. Based on quantitative analyzes of the published literature from Web of Science® and of DNA sequences of arthropod-hosted Wolbachia from GenBank, we made plausible that less than 1% of the expected 100 000 strains of Wolbachia in arthropods is known. Our findings suggest that more and globally better coordinated efforts in screening arthropods are needed to explore the true Wolbachia diversity and to help us understand the ecology and evolution of these host-endosymbiont interactions.}, }
@article {pmid31565579, year = {2019}, author = {Leveque, S and Afiq-Rosli, L and Ip, YCA and Jain, SS and Huang, D}, title = {Searching for phylogenetic patterns of Symbiodiniaceae community structure among Indo-Pacific Merulinidae corals.}, journal = {PeerJ}, volume = {7}, number = {}, pages = {e7669}, pmid = {31565579}, issn = {2167-8359}, abstract = {Over half of all extant stony corals (Cnidaria: Anthozoa: Scleractinia) harbour endosymbiotic dinoflagellates of the family Symbiodiniaceae, forming the foundational species of modern shallow reefs. However, whether these associations are conserved on the coral phylogeny remains unknown. Here we aim to characterise Symbiodiniaceae communities in eight closely-related species in the genera Merulina, Goniastrea and Scapophyllia, and determine if the variation in endosymbiont community structure can be explained by the phylogenetic relatedness among hosts. We perform DNA metabarcoding of the nuclear internal transcribed spacer 2 using Symbiodiniaceae-specific primers on 30 coral colonies to recover three major endosymbiont clades represented by 23 distinct types. In agreement with previous studies on Southeast Asian corals, we find an abundance of Cladocopium and Durusdinium, but also detect Symbiodinium types in three of the eight coral host species. Interestingly, differences in endosymbiont community structure are dominated by host variation at the intraspecific level, rather than interspecific, intergeneric or among-clade levels, indicating a lack of phylogenetic constraint in the coral-endosymbiont association among host species. Furthermore, the limited geographic sampling of four localities spanning the Western and Central Indo-Pacific preliminarily hints at large-scale spatial structuring of Symbiodiniaceae communities. More extensive collections of corals from various regions and environments will help us better understand the specificity of the coral-endosymbiont relationship.}, }
@article {pmid31564642, year = {2020}, author = {Molaei, G and Little, EAH and Stafford, KC and Gaff, H}, title = {A seven-legged tick: Report of a morphological anomaly in Ixodes scapularis (Acari: Ixodidae) biting a human host from the Northeastern United States.}, journal = {Ticks and tick-borne diseases}, volume = {11}, number = {1}, pages = {101304}, doi = {10.1016/j.ttbdis.2019.101304}, pmid = {31564642}, issn = {1877-9603}, mesh = {Anaplasma phagocytophilum/*isolation &amp; purification ; Animals ; Borrelia burgdorferi Group/*isolation &amp; purification ; Connecticut ; Female ; Host-Parasite Interactions ; Humans ; Ixodes/*anatomy &amp; histology/genetics/ultrastructure ; Male ; Microscopy, Electron, Scanning ; Middle Aged ; Rickettsia/*isolation &amp; purification ; Sequence Analysis, DNA ; }, abstract = {Cases of morphological anomalies in the blacklegged tick, Ixodes scapularis (Acari: Ixodidae), have recently been reported from the Northeastern and upper Midwestern United States, potentially complicating identification of this important vector of human disease-causing pathogens. We hereby report a case of a morphological anomaly in I. scapularis, biting a human host residing in Norwich, Connecticut. Using a dichotomous morphological key, high-resolution and scanning electron microscopy images, as well as DNA sequencing, the tick was identified as an adult female I. scapularis with three legs on the left side of the abdomen versus four on the right side, which we believe is the first case of ectromely in an adult I. scapularis. Using diagnostic genes in polymerase chain reaction, the specimen tested positive for Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum, the causative agents for Lyme disease and anaplasmosis, respectively, and also showed evidence of a rickettsial endosymbiont. Here we discuss recent reports of morphological anomalies in I. scapularis, and emphasize the significance of additional studies of teratology in this important tick species and its potential implications.}, }
@article {pmid31564246, year = {2019}, author = {Feng, H and Park, JS and Zhai, RG and Wilson, ACC}, title = {microRNA-92a regulates the expression of aphid bacteriocyte-specific secreted protein 1.}, journal = {BMC research notes}, volume = {12}, number = {1}, pages = {638}, pmid = {31564246}, issn = {1756-0500}, support = {R56 NS095893/NS/NINDS NIH HHS/United States ; }, mesh = {Animals ; Aphids/*genetics/microbiology ; Base Pairing ; Base Sequence ; Buchnera/physiology ; *Gene Expression Regulation ; Genes, Reporter ; Insect Proteins/*genetics/metabolism ; Luciferases/genetics/metabolism ; Mice ; MicroRNAs/*genetics/metabolism ; NIH 3T3 Cells ; Recombinant Proteins/genetics/metabolism ; Symbiosis/*genetics ; }, abstract = {OBJECTIVE: Aphids harbor a nutritional obligate endosymbiont in specialized cells called bacteriocytes, which aggregate to form an organ known as the bacteriome. Aphid bacteriomes display distinct gene expression profiles that facilitate the symbiotic relationship. Currently, the mechanisms that regulate these patterns of gene expression are unknown. Recently using computational pipelines, we identified miRNAs that are conserved in expression in the bacteriomes of two aphid species and proposed that they function as important regulators of bacteriocyte gene expression. Here using a dual luciferase assay in mouse NIH/3T3 cell culture, we aimed to experimentally validate the computationally predicted interaction between Myzus persicae miR-92a and the predicted target region of M. persicae bacteriocyte-specific secreted protein 1 (SP1) mRNA.<br><br>RESULTS: In the dual luciferase assay, miR-92a interacted with the SP1 target region resulting in a significant downregulation of the luciferase signal. Our results demonstrate that miR-92a interacts with SP1 to alter expression in a heterologous expression system, thereby supporting our earlier assertion that miRNAs are regulators of the aphid/Buchnera symbiotic interaction.}, }
@article {pmid31562384, year = {2020}, author = {Assié, A and Leisch, N and Meier, DV and Gruber-Vodicka, H and Tegetmeyer, HE and Meyerdierks, A and Kleiner, M and Hinzke, T and Joye, S and Saxton, M and Dubilier, N and Petersen, JM}, title = {Horizontal acquisition of a patchwork Calvin cycle by symbiotic and free-living Campylobacterota (formerly Epsilonproteobacteria).}, journal = {The ISME journal}, volume = {14}, number = {1}, pages = {104-122}, pmid = {31562384}, issn = {1751-7370}, mesh = {Animals ; Bivalvia/microbiology ; Carbon Cycle ; Citric Acid Cycle ; Epsilonproteobacteria/classification/genetics/*metabolism ; Gammaproteobacteria/genetics ; *Photosynthesis ; Phylogeny ; Symbiosis ; }, abstract = {Most autotrophs use the Calvin-Benson-Bassham (CBB) cycle for carbon fixation. In contrast, all currently described autotrophs from the Campylobacterota (previously Epsilonproteobacteria) use the reductive tricarboxylic acid cycle (rTCA) instead. We discovered campylobacterotal epibionts ("Candidatus Thiobarba") of deep-sea mussels that have acquired a complete CBB cycle and may have lost most key genes of the rTCA cycle. Intriguingly, the phylogenies of campylobacterotal CBB cycle genes suggest they were acquired in multiple transfers from Gammaproteobacteria closely related to sulfur-oxidizing endosymbionts associated with the mussels, as well as from Betaproteobacteria. We hypothesize that "Ca. Thiobarba" switched from the rTCA cycle to a fully functional CBB cycle during its evolution, by acquiring genes from multiple sources, including co-occurring symbionts. We also found key CBB cycle genes in free-living Campylobacterota, suggesting that the CBB cycle may be more widespread in this phylum than previously known. Metatranscriptomics and metaproteomics confirmed high expression of CBB cycle genes in mussel-associated "Ca. Thiobarba". Direct stable isotope fingerprinting showed that "Ca. Thiobarba" has typical CBB signatures, suggesting that it uses this cycle for carbon fixation. Our discovery calls into question current assumptions about the distribution of carbon fixation pathways in microbial lineages, and the interpretation of stable isotope measurements in the environment.}, }
@article {pmid31551286, year = {2019}, author = {Cato, ML and Jester, HD and Lavertu, A and Lyman, A and Tallent, LM and Mitchell, GC}, title = {Genome-Wide Analysis of Cell Cycle-Regulating Genes in the Symbiotic Dinoflagellate Breviolum minutum.}, journal = {G3 (Bethesda, Md.)}, volume = {9}, number = {11}, pages = {3843-3853}, pmid = {31551286}, issn = {2160-1836}, support = {T32 LM012409/LM/NLM NIH HHS/United States ; }, mesh = {Animals ; Cell Cycle/*genetics ; Cyclin-Dependent Kinases/genetics ; Dinoflagellida/*genetics ; Genome ; Phylogeny ; Sea Anemones/microbiology ; Symbiosis ; }, abstract = {A delicate relationship exists between reef-building corals and their photosynthetic endosymbionts. Unfortunately, this relationship can be disrupted, with corals expelling these algae when temperatures rise even marginally above the average summer maximum. Interestingly, several studies indicate that failure of corals to regulate symbiont cell divisions at high temperatures may underlie this disruption; increased proliferation of symbionts may stress host cells by over-production of reactive oxygen species or by disrupting the flow of nutrients. This needs to be further investigated, so to begin deciphering the molecular mechanisms controlling the cell cycle in these organisms, we used a computational approach to identify putative cell cycle-regulating genes in the genome of the dinoflagellate Breviolum minutum This species is important as an endosymbiont of Aiptasia pallida-an anemone that is used as a model for studying coral biology. We then correlated expression of these putative cell cycle genes with cell cycle phase in diurnally growing B. minutum in culture. This approach allowed us to identify a cyclin/cyclin-dependent kinase pair that may function in the G1/S transition-a likely point for coral cells to exert control over algal cell divisions.}, }
@article {pmid31551054, year = {2019}, author = {Lucas, JM and Gora, E and Salzberg, A and Kaspari, M}, title = {Antibiotics as chemical warfare across multiple taxonomic domains and trophic levels in brown food webs.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1911}, pages = {20191536}, pmid = {31551054}, issn = {1471-2954}, mesh = {Animals ; Anti-Bacterial Agents/*metabolism ; Bacteria ; Ecosystem ; *Environmental Microbiology ; *Food Chain ; Invertebrates/physiology ; Predatory Behavior ; }, abstract = {Bacteria and fungi secrete antibiotics to suppress and kill other microbes, but can these compounds be agents of competition against macroorganisms? We explore how one competitive tactic, antibiotic production, can structure the composition and function of brown food webs. This aspect of warfare between microbes and invertebrates is particularly important today as antibiotics are introduced into ecosystems via anthropogenic activities, but the ecological implications of these introductions are largely unknown. We hypothesized that antimicrobial compounds act as agents of competition against invertebrate and microbial competitors. Using field-like mesocosms, we tested how antifungal and antibacterial compounds influence microbes, invertebrates, and decomposition in the brown food web. Both antibiotics changed prokaryotic microbial community composition, but only the antibacterial changed invertebrate composition. Antibacterials reduced the abundance of invertebrate detritivores by 34%. However, the addition of antimicrobials did not ramify up the food web as predator abundances were unaffected. Decomposition rates did not change. To test the mechanisms of antibiotic effects, we provided antibiotic-laden water to individual invertebrate detritivores in separate microcosm experiments. We found that the antibiotic compounds can directly harm invertebrate taxa, probably through a disruption of endosymbionts. Combined, our results show that antibiotic compounds could be an effective weapon for microbes to compete against both microbial and invertebrate competitors. In the context of human introductions, the detrimental effects of antibiotics on invertebrate communities indicates that the scope of this anthropogenic disturbance is much greater than previously expected.}, }
@article {pmid31550003, year = {2019}, author = {Avtzis, DN and Schebeck, M and Petsopoulos, D and Memtsas, GI and Stauffer, C and Kavallieratos, NG and Athanassiou, CG and Boukouvala, MC}, title = {New Data on the Range Expansion of the Thaumetopoea pityocampa (Lepidoptera: Notodontidae) 'ENA clade' in Greece: The Role of Bacterial Endosymbionts.}, journal = {Journal of economic entomology}, volume = {112}, number = {6}, pages = {2761-2766}, doi = {10.1093/jee/toz216}, pmid = {31550003}, issn = {1938-291X}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Greece ; Humans ; *Moths ; *Wolbachia ; }, abstract = {The pine processionary moth, Thaumetopoea pityocampa (Denis and Schiffermüller), is an important insect in the Mediterranean region, as it defoliates pines and its urticating hairs can cause allergic reactions in humans and animals. Moreover, this species exhibits an interesting genetic structure as recently a distinct East-North African mtDNA lineage ('ENA clade') has been described. This clade has been recently detected in Greek populations where it has currently expanded its range by replacing the 'endemic' T. pityocampa lineages. Here, we report new data on the rapid spread of 'ENA clade' in the Greek island Evoia in only a few years. As the underlying mechanisms of the 'ENA clade' range expansion has not been studied so far, we screened T. pityocampa for an infection with the heritable bacterial endosymbionts Wolbachia (Bacteria: Anaplasmataceae), Cardinium (Bacteria: Bacteroidaceae), Rickettsia (Bacteria: Rickettsiaceae) and Spiroplasma (Bacteria: Spiroplasmataceae). These bacteria can manipulate the reproduction of infected hosts, something that could potentially explain the rapid spread of 'ENA clade' lineage. Therefore, we screened 28 individuals that exhibited T. pityocampa 'ENA clade' and 'endemic' T. pityocampa haplotypes from nine populations scattered all over Greece. None of them was infected with any of the four endosymbionts, suggesting that these bacteria do not cause reproductive manipulations in T. pityocampa lineages and, thus, other factors should be explored in future research efforts.}, }
@article {pmid31549736, year = {2020}, author = {Ogawa, M and Takahashi, M and Matsutani, M and Takada, N and Noda, S and Saijo, M}, title = {Obligate intracellular bacteria diversity in unfed Leptotrombidium scutellare larvae highlights novel bacterial endosymbionts of mites.}, journal = {Microbiology and immunology}, volume = {64}, number = {1}, pages = {1-9}, doi = {10.1111/1348-0421.12745}, pmid = {31549736}, issn = {1348-0421}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; *Bacterial Physiological Phenomena ; *Biodiversity ; High-Throughput Nucleotide Sequencing ; Humans ; Larva/*microbiology ; Life Cycle Stages ; Mites/*microbiology ; Orientia tsutsugamushi ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/genetics ; Scrub Typhus/microbiology ; Sequence Analysis ; *Symbiosis ; Trombiculidae/*microbiology ; Wolbachia/classification ; }, abstract = {It is well known that the mite Leptotrombidium scutellare carries the pathogen of scrub typhus, Orientia tsutsugamushi. However, our understanding of other bacterial endosymbionts of mites is limited. This study investigated the diversity of the obligate intracellular bacteria carried by L. scutellare using 16S rRNA gene amplicon analysis with next-generation sequencing. The results showed that the detected bacteria were classified into the genera Rickettsia, Wolbachia, and Rickettsiella and an unknown genus of the order Rickettsiales. For further classification of the detected bacteria, a representative read that was most closely related to the assigned taxonomic classification was subjected to homology search and phylogenic analysis. The results showed that some bacteria of the genus Rickettsia were identical or very close to the human pathogens Rickettsia akari, Rickettsia aeschlimannii, Rickettsia felis, and Rickettsia australis. The genetic distance between the genus Wolbachia bacteria in the present study and in previous reports is highly indicative that the bacteria in the present study can be classified as a new taxon of Wolbachia. This study detected obligate intracellular bacteria from unfed mites; thus, the mites did not acquire bacteria from infected animals or any other infectious sources. Finally, the present study demonstrated that various and novel bacterial endosymbionts of mites, in addition to O. tsutsugamushi, might uniquely evolve with the host mites throughout overlapping generations of the mite life cycle. The roles of the bacteria in mites and their pathogenicity should be further examined in studies based on bacterial isolation.}, }
@article {pmid31544193, year = {2020}, author = {Saraiva, RG and Dimopoulos, G}, title = {Bacterial natural products in the fight against mosquito-transmitted tropical diseases.}, journal = {Natural product reports}, volume = {37}, number = {3}, pages = {338-354}, doi = {10.1039/c9np00042a}, pmid = {31544193}, issn = {1460-4752}, support = {R01 AI141532/AI/NIAID NIH HHS/United States ; R01 AI122743/AI/NIAID NIH HHS/United States ; }, mesh = {Alkaloids/chemistry/pharmacology ; Animals ; Antimalarials/chemistry/pharmacology ; Antiviral Agents/*pharmacology ; Bacteria/*chemistry/metabolism ; Biological Products/chemistry/*pharmacology ; Culicidae/*microbiology ; Gastrointestinal Microbiome/physiology ; Humans ; Tetracyclines/chemistry/pharmacology ; Tropical Medicine ; Vector Borne Diseases/*drug therapy ; }, abstract = {Covering: up to 2019 Secondary metabolites of microbial origin have long been acknowledged as medically relevant, but their full potential remains largely unexploited. Of the countless natural compounds discovered thus far, only 5-10% have been isolated from microorganisms. At the same time, while whole-genome sequencing has demonstrated that bacteria and fungi often encode natural products, only a few genera have yet been mined for new compounds. This review explores the contributions of bacterial natural products to combatting infection by malaria parasites, filarial worms, and arboviruses such as dengue, Zika, Chikungunya, and West Nile. It highlights how molecules isolated from microorganisms ranging from marine cyanobacteria to mosquito endosymbionts can be exploited as antimicrobials and antivirals. Pursuit of this mostly untapped source of chemical entities will potentially result in new interventions against these tropical diseases, which are urgently needed to combat the increase in the incidence of resistance.}, }
@article {pmid31543454, year = {2019}, author = {Schiessl, K and Lilley, JLS and Lee, T and Tamvakis, I and Kohlen, W and Bailey, PC and Thomas, A and Luptak, J and Ramakrishnan, K and Carpenter, MD and Mysore, KS and Wen, J and Ahnert, S and Grieneisen, VA and Oldroyd, GED}, title = {NODULE INCEPTION Recruits the Lateral Root Developmental Program for Symbiotic Nodule Organogenesis in Medicago truncatula.}, journal = {Current biology : CB}, volume = {29}, number = {21}, pages = {3657-3668.e5}, pmid = {31543454}, issn = {1879-0445}, support = {BB/K003712/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Medicago truncatula/*genetics/growth &amp; development/metabolism ; Organogenesis, Plant/*genetics ; Plant Proteins/*genetics/metabolism ; Plant Root Nodulation/*genetics ; Plant Roots/genetics/*growth &amp; development ; *Symbiosis ; Transcription Factors/*genetics/metabolism ; }, abstract = {To overcome nitrogen deficiencies in the soil, legumes enter symbioses with rhizobial bacteria that convert atmospheric nitrogen into ammonium. Rhizobia are accommodated as endosymbionts within lateral root organs called nodules that initiate from the inner layers of Medicago truncatula roots in response to rhizobial perception. In contrast, lateral roots emerge from predefined founder cells as an adaptive response to environmental stimuli, including water and nutrient availability. CYTOKININ RESPONSE 1 (CRE1)-mediated signaling in the pericycle and in the cortex is necessary and sufficient for nodulation, whereas cytokinin is antagonistic to lateral root development, with cre1 showing increased lateral root emergence and decreased nodulation. To better understand the relatedness between nodule and lateral root development, we undertook a comparative analysis of these two root developmental programs. Here, we demonstrate that despite differential induction, lateral roots and nodules share overlapping developmental programs, with mutants in LOB-DOMAIN PROTEIN 16 (LBD16) showing equivalent defects in nodule and lateral root initiation. The cytokinin-inducible transcription factor NODULE INCEPTION (NIN) allows induction of this program during nodulation through activation of LBD16 that promotes auxin biosynthesis via transcriptional induction of STYLISH (STY) and YUCCAs (YUC). We conclude that cytokinin facilitates local auxin accumulation through NIN promotion of LBD16, which activates a nodule developmental program overlapping with that induced during lateral root initiation.}, }
@article {pmid31540983, year = {2019}, author = {Tian, PP and Chang, CY and Miao, NH and Li, MY and Liu, XD}, title = {Infections with Arsenophonus Facultative Endosymbionts Alter Performance of Aphids (Aphis gossypii) on an Amino-Acid-Deficient Diet.}, journal = {Applied and environmental microbiology}, volume = {85}, number = {23}, pages = {}, pmid = {31540983}, issn = {1098-5336}, mesh = {Amino Acids/deficiency ; Animals ; Aphids/growth &amp; development/*microbiology ; Cucumis sativus ; *Food Chain ; Gammaproteobacteria/*physiology ; Gossypium ; Nymph/growth &amp; development/microbiology ; *Symbiosis ; }, abstract = {Genetic polymorphism and endosymbiont infection are ubiquitous in aphid populations. It has been known that the obligate symbiont Buchnera provides aphids with essential amino acids which cannot be ingested from plant sap. Buchnera often coexists with facultative endosymbionts in aphids. However, it is unclear whether the facultative endosymbionts affect the aphid's amino acid requirements from diet. In this study, we found that the facultative endosymbiont status in populations of the cotton-melon aphid Aphis gossypii was associated with aphid genotype or host plant. The infection frequency of Arsenophonus in aphids living on cotton was significantly higher than that in aphids on cucumber, and cucumber leaves contained higher titers of free amino acids than cotton leaves, especially amino acids Leu, Arg, Ile, Val, and Phe. The net reproductive rates of five aphid genotypes infected with Arsenophonus were not different on the complete-amino-acid diet, but the values were significantly different among seven Arsenophonus-free aphid genotypes. Moreover, the net reproductive rates of aphids on the amino-acid-deficient diet were significantly affected by Arsenophonus infection and aphid genotype. Arsenophonus infection decreased aphid performance on the Phe-free diet but improved performance on the Leu-free diet and did not affect the performance on the Ile-free or Val-free diet. Arsenophonus infections altered aphid requirements for amino acids that were significantly different in cotton and cucumber leaves, suggesting this endosymbiont would modulate the host specialization of this aphid.IMPORTANCE The facultative endosymbiont Arsenophonus plays an important role in regulating reproduction through son killing, enemy resistance, and the dietary breadth of its insect hosts. In this study, we found Arsenophonus could alter aphid performance on the amino-acid-deficient diets. Arsenophonus infection increased aphid requirements for the amino acid Phe, but decreased requirements for the Leu. Cotton and cucumber leaves contained drastically different titers of free amino acids Phe and Leu, and aphids living on these two plants were infected with different incidences of Arsenophonus We hypothesize that host specialization or the host plant range of aphids may be mediated by Arsenophonus.}, }
@article {pmid31540253, year = {2019}, author = {De Jesus, CE and Ganser, C and Kessler, WH and White, ZS and Bhosale, CR and Glass, GE and Wisely, SM}, title = {A Survey of Tick-Borne Bacterial Pathogens in Florida.}, journal = {Insects}, volume = {10}, number = {9}, pages = {}, pmid = {31540253}, issn = {2075-4450}, support = {U01 CK000510/CK/NCEZID CDC HHS/United States ; 1U01CK000510-01/CC/CDC HHS/United States ; }, abstract = {Within the past three decades, new bacterial etiological agents of tick-borne disease have been discovered in the southeastern U.S., and the number of reported tick-borne pathogen infections has increased. In Florida, few systematic studies have been conducted to determine the presence of tick-borne bacterial pathogens. This investigation examined the distribution and presence of tick-borne bacterial pathogens in Florida. Ticks were collected by flagging at 41 field sites, spanning the climatic regions of mainland Florida. DNA was extracted individually from 1608 ticks and screened for Anaplasma, Borrelia, Ehrlichia and Rickettsia using conventional PCR and primers that amplified multiple species for each genus. PCR positive samples were Sanger sequenced. Four species of ticks were collected: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. Within these ticks, six bacterial species were identified: Borrelia burgdorferi, Borrelia lonestari, Ehrlichia ewingii, Rickettsia amblyommatis, Rickettsia andeanae, Rickettsia parkeri, and Rickettsia endosymbionts. Pathogenic Borrelia, Ehrlichia, and Rickettsia species were all detected in the North and North-Central Florida counties; however, we found only moderate concordance between the distribution of ticks infected with pathogenic bacteria and human cases of tick-borne diseases in Florida. Given the diversity and numerous bacterial species detected in ticks in Florida, further investigations should be conducted to identify regional hotspots of tick-borne pathogens.}, }
@article {pmid31537670, year = {2019}, author = {Mead, ME and Raja, HA and Steenwyk, JL and Knowles, SL and Oberlies, NH and Rokas, A}, title = {Draft Genome Sequence of the Griseofulvin-Producing Fungus Xylaria flabelliformis Strain G536.}, journal = {Microbiology resource announcements}, volume = {8}, number = {38}, pages = {}, pmid = {31537670}, issn = {2576-098X}, support = {T32 AT008938/AT/NCCIH NIH HHS/United States ; }, abstract = {The draft genome of the ascomycete fungus Xylaria flabelliformis (previously known as Xylaria cubensis) was sequenced using Illumina paired-end technology. The assembled genome is 41.2 Mb long and contains 11,404 genes. This genome will contribute to our understanding of X. flabelliformis secondary metabolism and the organism's ability to live as a decomposer as well as an endosymbiont.}, }
@article {pmid31511895, year = {2020}, author = {Bellan, A and Bucci, F and Perin, G and Alboresi, A and Morosinotto, T}, title = {Photosynthesis Regulation in Response to Fluctuating Light in the Secondary Endosymbiont Alga Nannochloropsis gaditana.}, journal = {Plant &amp; cell physiology}, volume = {61}, number = {1}, pages = {41-52}, doi = {10.1093/pcp/pcz174}, pmid = {31511895}, issn = {1471-9053}, mesh = {Biodiversity ; Electron Transport/physiology ; *Light ; Oxidative Stress ; Photosynthesis/*physiology ; Photosystem I Protein Complex/metabolism/radiation effects ; Plants/metabolism ; Stramenopiles/growth &amp; development/*metabolism/radiation effects ; Symbiosis/*physiology ; }, abstract = {In nature, photosynthetic organisms are exposed to highly dynamic environmental conditions where the excitation energy and electron flow in the photosynthetic apparatus need to be continuously modulated. Fluctuations in incident light are particularly challenging because they drive oversaturation of photosynthesis with consequent oxidative stress and photoinhibition. Plants and algae have evolved several mechanisms to modulate their photosynthetic machinery to cope with light dynamics, such as thermal dissipation of excited chlorophyll states (non-photochemical quenching, NPQ) and regulation of electron transport. The regulatory mechanisms involved in the response to light dynamics have adapted during evolution, and exploring biodiversity is a valuable strategy for expanding our understanding of their biological roles. In this work, we investigated the response to fluctuating light in Nannochloropsis gaditana, a eukaryotic microalga of the phylum Heterokonta originating from a secondary endosymbiotic event. Nannochloropsis gaditana is negatively affected by light fluctuations, leading to large reductions in growth and photosynthetic electron transport. Exposure to light fluctuations specifically damages photosystem I, likely because of the ineffective regulation of electron transport in this species. The role of NPQ, also assessed using a mutant strain specifically depleted of this response, was instead found to be minor, especially in responding to the fastest light fluctuations.}, }
@article {pmid31507561, year = {2019}, author = {Meng, L and Li, X and Cheng, X and Zhang, H}, title = {16S rRNA Gene Sequencing Reveals a Shift in the Microbiota of Diaphorina citri During the Psyllid Life Cycle.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {1948}, pmid = {31507561}, issn = {1664-302X}, abstract = {The Asian citrus psyllid (Diaphorina citri) is a major pest of citrus trees as it transmits Candidatus Liberibacter asiaticus (CLas). The composition of a host's microbiota can affect the evolution and ecological distribution of the host. This study monitored the compositional shifts in the citrus psyllid microbiota through all the life stages (egg, nymph 1-5 stages, and adult) by next-generation sequencing (NGS) and quantitative real-time PCR. There were clear differences in both α- and β-diversity of microbiota through the psyllid life stages. Microbiota diversity was markedly higher in the nymph 2-5 stages than in the adult, egg, and nymph 1 stages. Proteobacteria were dominant in all the life stages of D. citri, representing >97.5% of the total bacterial community, and Candidatus Profftella armature was the dominant genus in all the life stages. Data from the qPCR analysis showed an exponential increase in the populations of three D. citri endosymbionts: Candidatus Profftella armature, Candidatus Carsonella ruddii, and Wolbachia. The gut bacterium Pantoea was present in all the life stages, but it was markedly higher in the nymph 2-5 stages. The microbiota composition substantially differed among the egg-nymph 1, nymphs 2-5, and adult stages. Therefore, we successfully characterized the microbiota dynamics and thus identified a microbiota shift during the life cycle of D. citri by 16S rRNA gene sequencing and quantitative PCR. Moreover, 16S rRNA gene sequencing suggested that D. citri acquired the ability to bear CLas in the nymph 1 stage. This study enhances our understanding of microbial establishment in the developing D. citri and provides a reference resource for the identification of potential biocontrol approaches against this pest.}, }
@article {pmid31505824, year = {2019}, author = {Smith, DAS and Traut, W and Martin, SH and Ireri, P and Omufwoko, KS and Ffrench-Constant, R and Gordon, IJ}, title = {Neo Sex Chromosomes, Colour Polymorphism and Male-Killing in the African Queen Butterfly, Danaus chrysippus (L.).}, journal = {Insects}, volume = {10}, number = {9}, pages = {}, pmid = {31505824}, issn = {2075-4450}, abstract = {Danaus chrysippus (L.), one of the world's commonest butterflies, has an extensive range throughout the Old-World tropics. In Africa it is divided into four geographical subspecies which overlap and hybridise freely in the East African Rift: Here alone a male-killing (MK) endosymbiont, Spiroplasma ixodetis, has invaded, causing female-biased populations to predominate. In ssp. chrysippus, inside the Rift only, an autosome carrying a colour locus has fused with the W chromosome to create a neo-W chromosome. A total of 40-100% of Rift females are neo-W and carry Spiroplasma, thus transmitting a linked, matrilineal neo-W, MK complex. As neo-W females have no sons, half the mother's genes are lost in each generation. Paradoxically, although neo-W females have no close male relatives and are thereby forced to outbreed, MK restricts gene flow between subspecies and may thus promote speciation. The neo-W chromosome originated in the Nairobi region around 2.2 k years ago and subsequently spread throughout the Rift contact zone in some 26 k generations, possibly assisted by not having any competing brothers. Our work on the neo-W chromosome, the spread of Spiroplasma and possible speciation is ongoing.}, }
@article {pmid31504075, year = {2019}, author = {Perlmutter, JI and Bordenstein, SR and Unckless, RL and LePage, DP and Metcalf, JA and Hill, T and Martinez, J and Jiggins, FM and Bordenstein, SR}, title = {The phage gene wmk is a candidate for male killing by a bacterial endosymbiont.}, journal = {PLoS pathogens}, volume = {15}, number = {9}, pages = {e1007936}, pmid = {31504075}, issn = {1553-7374}, support = {WT094664MA/WT_/Wellcome Trust/United Kingdom ; R21 HD086833/HD/NICHD NIH HHS/United States ; P30 DK058404/DK/NIDDK NIH HHS/United States ; S10 OD021630/OD/NIH HHS/United States ; R21 AI133522/AI/NIAID NIH HHS/United States ; P30 EY008126/EY/NEI NIH HHS/United States ; P30 CA068485/CA/NCI NIH HHS/United States ; R01 AI132581/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; U24 DK059637/DK/NIDDK NIH HHS/United States ; R01 AI139154/AI/NIAID NIH HHS/United States ; 281668/ERC_/European Research Council/International ; P30 DK020593/DK/NIDDK NIH HHS/United States ; R00 GM114714/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Animals, Genetically Modified ; DNA-Binding Proteins/genetics/physiology ; Drosophila/embryology/microbiology/virology ; Drosophila melanogaster/embryology/microbiology/virology ; Female ; Genes, Lethal ; Genes, Viral ; Host Microbial Interactions/genetics/physiology ; Male ; Prophages/*genetics/*pathogenicity/physiology ; Sex Ratio ; Symbiosis/genetics/physiology ; Viral Proteins/genetics/physiology ; Wolbachia/*pathogenicity/*virology ; }, abstract = {Wolbachia are the most widespread maternally-transmitted bacteria in the animal kingdom. Their global spread in arthropods and varied impacts on animal physiology, evolution, and vector control are in part due to parasitic drive systems that enhance the fitness of infected females, the transmitting sex of Wolbachia. Male killing is one common drive mechanism wherein the sons of infected females are selectively killed. Despite decades of research, the gene(s) underlying Wolbachia-induced male killing remain unknown. Here using comparative genomic, transgenic, and cytological approaches in fruit flies, we identify a candidate gene in the eukaryotic association module of Wolbachia prophage WO, termed WO-mediated killing (wmk), which transgenically causes male-specific lethality during early embryogenesis and cytological defects typical of the pathology of male killing. The discovery of wmk establishes new hypotheses for the potential role of phage genes in sex-specific lethality, including the control of arthropod pests and vectors.}, }
@article {pmid31500667, year = {2019}, author = {Fisher, ML and Levine, JF and Guy, JS and Mochizuki, H and Breen, M and Schal, C and Watson, DW}, title = {Lack of influence by endosymbiont Wolbachia on virus titer in the common bed bug, Cimex lectularius.}, journal = {Parasites &amp; vectors}, volume = {12}, number = {1}, pages = {436}, pmid = {31500667}, issn = {1756-3305}, mesh = {Animals ; Bedbugs/*microbiology/*virology ; Calicivirus, Feline/*growth &amp; development/*isolation &amp; purification ; *Microbial Interactions ; *Viral Load ; Wolbachia/*growth &amp; development ; }, abstract = {BACKGROUND: The common bed bug, Cimex lectularius, is an obligatory blood-feeding ectoparasite that requires a blood meal to molt and produce eggs. Their frequent biting to obtain blood meals and intimate association with humans increase the potential for disease transmission. However, despite more than 100 years of inquiry into bed bugs as potential disease vectors, they still have not been conclusively linked to any pathogen or disease. This ecological niche is extraordinarily rare, given that nearly every other blood-feeding arthropod is associated with some type of human or zoonotic disease. Bed bugs rely on the bacteria Wolbachia as an obligate endosymbiont to biosynthesize B vitamins, since they acquire a nutritionally deficient diet, but it is unknown if Wolbachia confers additional benefits to its bed bug host. In some insects, Wolbachia induces resistance to viruses such as Dengue, Chikungunya, West Nile, Drosophila C and Zika, and primes the insect immune system in other blood-feeding insects. Wolbachia might have evolved a similar role in its mutualistic association with the bed bug. In this study, we evaluated the influence of Wolbachia on virus replication within C. lectularius.<br><br>METHODS: We used feline calicivirus as a model pathogen. We fed 40 bed bugs from an established line of Wolbachia-cured and a line of Wolbachia-positive C. lectularius a virus-laden blood meal, and quantified the amount of virus over five time intervals post-feeding. The antibiotic rifampicin was used to cure bed bugs of Wolbachia.<br><br>RESULTS: There was a significant effect of time post-feeding, as the amount of virus declined by ~90% over 10 days in both groups, but no significant difference in virus titer was observed between the Wolbachia-positive and Wolbachia-cured groups.<br><br>CONCLUSIONS: These findings suggest that other mechanisms are involved in virus suppression within bed bugs, independent of the influence of Wolbachia, and our conclusions underscore the need for future research.}, }
@article {pmid31500535, year = {2019}, author = {Foster, RA and Zehr, JP}, title = {Diversity, Genomics, and Distribution of Phytoplankton-Cyanobacterium Single-Cell Symbiotic Associations.}, journal = {Annual review of microbiology}, volume = {73}, number = {}, pages = {435-456}, doi = {10.1146/annurev-micro-090817-062650}, pmid = {31500535}, issn = {1545-3251}, mesh = {*Biodiversity ; Cyanobacteria/*classification/*growth &amp; development ; Endophytes/classification/growth &amp; development ; Host Microbial Interactions ; Nitrogen Fixation ; Phototrophic Processes ; Phytoplankton/*microbiology/physiology ; *Symbiosis ; }, abstract = {Cyanobacteria are common in symbiotic relationships with diverse multicellular organisms (animals, plants, fungi) in terrestrial environments and with single-celled heterotrophic, mixotrophic, and autotrophic protists in aquatic environments. In the sunlit zones of aquatic environments, diverse cyanobacterial symbioses exist with autotrophic taxa in phytoplankton, including dinoflagellates, diatoms, and haptophytes (prymnesiophytes). Phototrophic unicellular cyanobacteria related to Synechococcus and Prochlorococcus are associated with a number of groups. N2-fixing cyanobacteria are symbiotic with diatoms and haptophytes. Extensive genome reduction is involved in the N2-fixing endosymbionts, most dramatically in the unicellular cyanobacteria associated with haptophytes, which have lost most of the photosynthetic apparatus, the ability to fix C, and the tricarboxylic acid cycle. The mechanisms involved in N2-fixing symbioses may involve more interactions beyond simple exchange of fixed C for N. N2-fixing cyanobacterial symbioses are widespread in the oceans, even more widely distributed than the best-known free-living N2-fixing cyanobacteria, suggesting they may be equally or more important in the global ocean biogeochemical cycle of N.Despite their ubiquitous nature and significance in biogeochemical cycles, cyanobacterium-phytoplankton symbioses remain understudied and poorly understood.}, }
@article {pmid31495588, year = {2019}, author = {Iwai, S and Fujita, K and Takanishi, Y and Fukushi, K}, title = {Photosynthetic Endosymbionts Benefit from Host's Phagotrophy, Including Predation on Potential Competitors.}, journal = {Current biology : CB}, volume = {29}, number = {18}, pages = {3114-3119.e3}, doi = {10.1016/j.cub.2019.07.074}, pmid = {31495588}, issn = {1879-0445}, mesh = {Animals ; Biological Evolution ; Chlamydomonas reinhardtii/metabolism ; Chlorella/*growth &amp; development/metabolism ; Ecosystem ; Light ; Paramecium/metabolism ; Phagocytosis/physiology ; Photosynthesis ; Predatory Behavior ; Symbiosis/*physiology ; }, abstract = {In many endosymbioses, hosts have been shown to benefit from symbiosis, but it remains unclear whether intracellular endosymbionts benefit from their association with hosts [1, 2]. This makes it difficult to determine evolutionary mechanisms underlying cooperative behaviors between hosts and intracellular endosymbionts, such as mutual exchange of vital resources. Here, we investigate the fitness effects of symbiosis on the ciliate host Paramecium bursaria and on the algal endosymbiont Chlorella [3, 4], using experimental microcosms that include the free-living alga Chlamydomonas reinhardtii to mimic ecologically realistic conditions. We demonstrate that both host ciliate and the endosymbiotic algae gain fitness benefits from the symbiosis when another alga C. reinhardtii is present in the system. Specifically, the endosymbiotic Chlorella can grow as the host ciliate feeds and grows on C. reinhardtii, whereas the growth of free-living Chlorella is reduced by its competitor, C. reinhardtii. Thus, we propose that the endosymbiotic algae benefit from the host's phagotrophy, which allows the endosymbiont to access particulate nutrient sources and to indirectly prey on the potential competitors competing with its free-living counterparts. Even though the ecological contexts in which each partner receives its benefits differ, both partners would gain net fitness benefits in an ecological timescale. Thus, the cooperative behaviors can evolve through fitness feedback (partner fidelity feedback) between the host and the endosymbiont, without need for special partner control mechanisms. The proposed ecological and evolutionary mechanisms provide a basis for understanding cooperative resource exchanges in endosymbioses, including many photosynthetic endosymbioses widespread in aquatic ecosystems.}, }
@article {pmid31491378, year = {2019}, author = {Zheng, Y and Shen, W and Bi, J and Chen, MY and Wang, RF and Ai, H and Wang, YF}, title = {Small RNA analysis provides new insights into cytoplasmic incompatibility in Drosophila melanogaster induced by Wolbachia.}, journal = {Journal of insect physiology}, volume = {118}, number = {}, pages = {103938}, doi = {10.1016/j.jinsphys.2019.103938}, pmid = {31491378}, issn = {1879-1611}, mesh = {3' Untranslated Regions ; Animals ; Cytoplasm/*genetics/pathology ; Drosophila melanogaster/embryology/genetics/metabolism/*microbiology ; Female ; *Gene Expression Regulation, Developmental ; Male ; MicroRNAs/genetics ; RNA, Small Untranslated ; Symbiosis ; Testis ; Wolbachia/*physiology ; }, abstract = {Wolbachia is a genus of endosymbiotic bacteria that induce a wide range of effects on their insect hosts. Cytoplasmic incompatibility (CI) is the most common phenotype mediated by Wolbachia and results in embryonic lethality when Wolbachia-infected males mate with uninfected females. Studies have revealed that bacteria can regulate many cellular processes in their hosts using small non-coding RNAs, so we investigated the involvement of small RNAs (sRNAs) in CI. Comparison of sRNA libraries between Wolbachia-infected and uninfected Drosophila melanogaster testes revealed 18 novel microRNAs (miRNAs), of which 12 were expressed specifically in Wolbachia-infected flies and one specifically in Wolbachia-uninfected flies. Furthermore, ten miRNAs showed differential expression, with four upregulated and six downregulated in Wolbachia-infected flies. Of the upregulated miRNAs, nov-miR-12 exhibited the highest upregulation in the testes of D. melanogaster. We then identified pipsqueak (psq) as the target gene of nov-miR-12 with the greatest complementarity in its 3' untranslated region (UTR). Wolbachia infection was correlated with reduced psq expression in D. melanogaster, and luciferase assays demonstrated that nov-miR-12 could downregulate psq through binding to its 3'UTR region. Knockdown of psq in Wolbachia-free fly testes significantly reduced egg hatching rate and mimicked the cellular abnormalities of Wolbachia-induced CI in embryos, including asynchronous nuclear division, chromatin bridging, and chromatin fragmentation. These results suggest that Wolbachia may induce CI in insect hosts by miRNA-mediated changes in host gene expression. Moreover, these findings reveal a potential molecular strategy for elucidating the complex interactions between endosymbionts and their insect hosts, such as Wolbachia-driven CI.}, }
@article {pmid31481951, year = {2019}, author = {Jiménez-Leiva, A and Cabrera, JJ and Bueno, E and Torres, MJ and Salazar, S and Bedmar, EJ and Delgado, MJ and Mesa, S}, title = {Expanding the Regulon of the Bradyrhizobium diazoefficiens NnrR Transcription Factor: New Insights Into the Denitrification Pathway.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {1926}, pmid = {31481951}, issn = {1664-302X}, abstract = {Denitrification in the soybean endosymbiont Bradyrhizobium diazoefficiens is controlled by a complex regulatory network composed of two hierarchical cascades, FixLJ-FixK2-NnrR and RegSR-NifA. In the former cascade, the CRP/FNR-type transcription factors FixK2 and NnrR exert disparate control on expression of core denitrifying systems encoded by napEDABC, nirK, norCBQD, and nosRZDFYLX genes in response to microoxia and nitrogen oxides, respectively. To identify additional genes controlled by NnrR and involved in the denitrification process in B. diazoefficiens, we compared the transcriptional profile of an nnrR mutant with that of the wild type, both grown under anoxic denitrifying conditions. This approach revealed more than 170 genes were simultaneously induced in the wild type and under the positive control of NnrR. Among them, we found the cycA gene which codes for the c 550 soluble cytochrome (CycA), previously identified as an intermediate electron donor between the bc 1 complex and the denitrifying nitrite reductase NirK. Here, we demonstrated that CycA is also required for nitrous oxide reductase activity. However, mutation in cycA neither affected nosZ gene expression nor NosZ protein steady-state levels. Furthermore, cycA, nnrR and its proximal divergently oriented nnrS gene, are direct targets for FixK2 as determined by in vitro transcription activation assays. The dependence of cycA expression on FixK2 and NnrR in anoxic denitrifying conditions was validated at transcriptional level, determined by quantitative reverse transcription PCR, and at the level of protein by performing heme c-staining of soluble cytochromes. Thus, this study expands the regulon of NnrR and demonstrates the role of CycA in the activity of the nitrous oxide reductase, the key enzyme for nitrous oxide mitigation.}, }
@article {pmid31481018, year = {2019}, author = {Christensen, S and Camacho, M and Sharmin, Z and Momtaz, AJMZ and Perez, L and Navarro, G and Triana, J and Samarah, H and Turelli, M and Serbus, LR}, title = {Quantitative methods for assessing local and bodywide contributions to Wolbachia titer in maternal germline cells of Drosophila.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {206}, pmid = {31481018}, issn = {1471-2180}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; }, mesh = {Animal Feed/analysis ; Animals ; Cytological Techniques/*methods ; Drosophila melanogaster/metabolism/*microbiology ; Female ; Ovary/growth &amp; development/microbiology ; Ovum/growth &amp; development/*microbiology ; Polymerase Chain Reaction/*methods ; Wolbachia/genetics/*growth &amp; development/isolation &amp; purification ; }, abstract = {BACKGROUND: Little is known about how bacterial endosymbionts colonize host tissues. Because many insect endosymbionts are maternally transmitted, egg colonization is critical for endosymbiont success. Wolbachia bacteria, carried by approximately half of all insect species, provide an excellent model for characterizing endosymbiont infection dynamics. To date, technical limitations have precluded stepwise analysis of germline colonization by Wolbachia. It is not clear to what extent titer-altering effects are primarily mediated by growth rates of Wolbachia within cell lineages or migration of Wolbachia between cells.<br><br>RESULTS: The objective of this work is to inform mechanisms of germline colonization through use of optimized methodology. The approaches are framed in terms of nutritional impacts on Wolbachia. Yeast-rich diets in particular have been shown to suppress Wolbachia titer in the Drosophila melanogaster germline. To determine the extent of Wolbachia sensitivity to diet, we optimized 3-dimensional, multi-stage quantification of Wolbachia titer in maternal germline cells. Technical and statistical validation confirmed the identity of Wolbachia in vivo, the reproducibility of Wolbachia quantification and the statistical power to detect these effects. The data from adult feeding experiments demonstrated that germline Wolbachia titer is distinctly sensitive to yeast-rich host diets in late oogenesis. To investigate the physiological basis for these nutritional impacts, we optimized methodology for absolute Wolbachia quantification by real-time qPCR. We found that yeast-rich diets exerted no significant effect on bodywide Wolbachia titer, although ovarian titers were significantly reduced. This suggests that host diets affects Wolbachia distribution between the soma and late stage germline cells. Notably, relative qPCR methods distorted apparent wsp abundance, due to altered host DNA copy number in yeast-rich conditions. This highlights the importance of absolute quantification data for testing mechanistic hypotheses.<br><br>CONCLUSIONS: We demonstrate that absolute quantification of Wolbachia, using well-controlled cytological and qPCR-based methods, creates new opportunities to determine how bacterial abundance within the germline relates to bacterial distribution within the body. This methodology can be applied to further test germline infection dynamics in response to chemical treatments, genetic conditions, new host/endosymbiont combinations, or potentially adapted to analyze other cell and tissue types.}, }
@article {pmid31471686, year = {2019}, author = {Li, Y and Liu, X and Guo, H}, title = {Population Dynamics of Wolbachia in Laodelphax striatellus (Fallén) Under Successive Stress of Antibiotics.}, journal = {Current microbiology}, volume = {76}, number = {11}, pages = {1306-1312}, pmid = {31471686}, issn = {1432-0991}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Biodiversity ; Female ; Hemiptera/*microbiology ; Male ; Tetracycline/*pharmacology ; Wolbachia/*drug effects/growth &amp; development ; }, abstract = {Wolbachia are the most common symbionts in arthropods; antibiotic treatment for eliminating the symbionts from their host is necessary to investigate the functions. Tetracycline antibiotics are widely used to remove endosymbiont Wolbachia from insect hosts. However, very little has been known on the effects of tetracycline on population size of Wolbachia in small brown planthopper (SBPH), Laodelphax striatellus (Fallén), an important insect pest of rice in Asia. Here, we investigated the dynamics of Wolbachia population density in females and males of L. striatellus by real-time fluorescent quantitative PCR method. The Wolbachia density in females and males of L. striatellus all declined sharply after treatment with 2 mg/mL tetracycline for one generation, and continued to decrease to a level which could not be detected by both qPCR and diagnostic PCR after treated for another generation, then maintained at 0 in the following three generations with continuous antibiotic treatment. Wolbachia infection did not recover in L. striatellus after stopping tetracycline treatment for ten generations. This is the first report to precisely monitor the population dynamics of Wolbachia in L. striatellus during successive tetracycline treatment and after that. The results provide a useful method for evaluating the efficiency of artificial operation of endosymbionts.}, }
@article {pmid31470668, year = {2019}, author = {Doellman, MM and Schuler, H and Jean, GS and Hood, GR and Egan, SP and Powell, THQ and Glover, MM and Bruzzese, DJ and Smith, JJ and Yee, WL and Goughnour, RB and Rull, J and Aluja, M and Feder, JL}, title = {Geographic and Ecological Dimensions of Host Plant-Associated Genetic Differentiation and Speciation in the Rhagoletis cingulata (Diptera: Tephritidae) Sibling Species Group.}, journal = {Insects}, volume = {10}, number = {9}, pages = {}, pmid = {31470668}, issn = {2075-4450}, abstract = {Ascertaining the causes of adaptive radiation is central to understanding how new species arise and come to vary with their resources. The ecological theory posits adaptive radiation via divergent natural selection associated with novel resource use; an alternative suggests character displacement following speciation in allopatry and then secondary contact of reproductively isolated but ecologically similar species. Discriminating between hypotheses, therefore, requires the establishment of a key role for ecological diversification in initiating speciation versus a secondary role in facilitating co-existence. Here, we characterize patterns of genetic variation and postzygotic reproductive isolation for tephritid fruit flies in the Rhagoletis cingulata sibling species group to assess the significance of ecology, geography, and non-adaptive processes for their divergence. Our results support the ecological theory: no evidence for intrinsic postzygotic reproductive isolation was found between two populations of allopatric species, while nuclear-encoded microsatellites implied strong ecologically based reproductive isolation among sympatric species infesting different host plants. Analysis of mitochondrial DNA suggested, however, that cytoplasmic-related reproductive isolation may also exist between two geographically isolated populations within R cingulata. Thus, ecology associated with sympatric host shifts and cytoplasmic effects possibly associated with an endosymbiont may be the key initial drivers of the radiation of the R. cingulata group.}, }
@article {pmid31470232, year = {2019}, author = {Husnik, F and Keeling, PJ}, title = {The fate of obligate endosymbionts: reduction, integration, or extinction.}, journal = {Current opinion in genetics &amp; development}, volume = {58-59}, number = {}, pages = {1-8}, doi = {10.1016/j.gde.2019.07.014}, pmid = {31470232}, issn = {1879-0380}, mesh = {Animals ; *Biological Evolution ; Extinction, Biological ; Mitochondria/*genetics/metabolism ; Phylogeny ; Plastids/genetics/metabolism ; Protein Transport ; Symbiosis/*genetics/physiology ; }, abstract = {Whether mitochondria and plastids originated by endosymbiosis is no longer questioned, but we still do not understand the actual process of integration. Other, younger endosymbiotic systems are, however, relatively common. Traditionally, it was not clear whether these systems could be directly and informatively compared to organelles because they appear sufficiently different. Surprisingly, new data from both organelles and endosymbiotic bacteria are changing this view. As more commonalities are described, the processes underlaying these associations appear to be not so different after all. New models for endosymbiotic associations emphasize the importance of transient stages, conflict more than cooperation, and population genetics forces that lead to genome reduction, which in turn restricts most endosymbionts to one of a few possible evolutionary pathways, commonly ending with extinction.}, }
@article {pmid31462919, year = {2019}, author = {Monticelli, LS and Nguyen, LTH and Amiens-Desneux, E and Luo, C and Lavoir, AV and Gatti, JL and Desneux, N}, title = {The preference-performance relationship as a means of classifying parasitoids according to their specialization degree.}, journal = {Evolutionary applications}, volume = {12}, number = {8}, pages = {1626-1640}, pmid = {31462919}, issn = {1752-4571}, abstract = {Host range in parasitoids could be described by the preference-performance hypothesis (PPH) where preference is defined as host acceptance and performance is defined as the sum of all species on which parasitoid offspring can complete their life cycle. The PPH predicts that highly suitable hosts will be preferred by ovipositing females. However, generalist parasitoids may not conform to this hypothesis if they attack a large range of hosts of varying suitability. Under laboratory conditions, we tested the PPH relationship of three aphid parasitoids currently considered as generalist species (Aphelinus abdominalis, Aphidius ervi, Diaeretiella rapae). As expected, the three parasitoids species showed low selectivity, i.e., females stung all aphid species encountered (at least in some extent). However, depending on the parasitoid species, only 42%-58% of aphid species enabled producing parasitoid offspring. We did not find a correlation between the extent of preference and the performance of three generalist aphid parasitoids. For A. ervi, host phylogeny is also important as females showed higher attack and developmental rates on hosts closely related to the most suitable one. In addition, traits such as (a) the presence of protective secondary endosymbionts, for example, Hamiltonella defensa detected in Aphis fabae and Metopolophium dirhodum and (b) the sequestration of plant toxins as defense mechanism against parasitism, for example, in Aphis nerii and Brevicoryne brassicae, were likely at play to some extent in narrowing parasitoid host range. The lack of PPH relationship involved a low selectivity leading to a high adaptability, as well as selection pressure; the combination of which enabled the production of offspring in a new host species or a new environment. Testing for PPH relationships in parasitoids may provide useful cues to classify parasitoids in terms of specialization degree.}, }
@article {pmid31462916, year = {2019}, author = {Ayala, D and Akone-Ella, O and Rahola, N and Kengne, P and Ngangue, MF and Mezeme, F and Makanga, BK and Nigg, M and Costantini, C and Simard, F and Prugnolle, F and Roche, B and Duron, O and Paupy, C}, title = {Natural Wolbachia infections are common in the major malaria vectors in Central Africa.}, journal = {Evolutionary applications}, volume = {12}, number = {8}, pages = {1583-1594}, pmid = {31462916}, issn = {1752-4571}, abstract = {During the last decade, the endosymbiont bacterium Wolbachia has emerged as a biological tool for vector disease control. However, for long time, it was believed that Wolbachia was absent in natural populations of Anopheles. The recent discovery that species within the Anopheles gambiae complex host Wolbachia in natural conditions has opened new opportunities for malaria control research in Africa. Here, we investigated the prevalence and diversity of Wolbachia infection in 25 African Anopheles species in Gabon (Central Africa). Our results revealed the presence of Wolbachia in 16 of these species, including the major malaria vectors in this area. The infection prevalence varied greatly among species, confirming that sample size is a key factor to detect the infection. Moreover, our sequencing and phylogenetic analyses showed the important diversity of Wolbachia strains that infect Anopheles. Co-evolutionary analysis unveiled patterns of Wolbachia transmission within some Anopheles species, suggesting that past independent acquisition events were followed by co-cladogenesis. The large diversity of Wolbachia strains that infect natural populations of Anopheles offers a promising opportunity to select suitable phenotypes for suppressing Plasmodium transmission and/or manipulating Anopheles reproduction, which in turn could be used to reduce the malaria burden in Africa.}, }
@article {pmid31455638, year = {2019}, author = {Lim, SJ and Alexander, L and Engel, AS and Paterson, AT and Anderson, LC and Campbell, BJ}, title = {Extensive Thioautotrophic Gill Endosymbiont Diversity within a Single Ctena orbiculata (Bivalvia: Lucinidae) Population and Implications for Defining Host-Symbiont Specificity and Species Recognition.}, journal = {mSystems}, volume = {4}, number = {4}, pages = {}, pmid = {31455638}, issn = {2379-5077}, abstract = {Seagrass-dwelling members of the bivalve family Lucinidae harbor environmentally acquired gill endosymbionts. According to previous studies, lucinid symbionts potentially represent multiple strains from a single thioautotrophic gammaproteobacterium species. This study utilized genomic- and transcriptomic-level data to resolve symbiont taxonomic, genetic, and functional diversity from Ctena orbiculata endosymbiont populations inhabiting carbonate-rich sediment at Sugarloaf Key, FL (USA). The sediment had mixed seagrass and calcareous green alga coverage and also was colonized by at least five other lucinid species. Four coexisting, thioautotrophic endosymbiont operational taxonomic units (OTUs), likely representing four strains from two different bacterial species, were identified from C. orbiculata Three of these OTUs also occurred at high relative abundances in the other sympatric lucinid species. Interspecies genetic differences averaged about 5% lower at both pairwise average nucleotide identity and amino acid identity than interstrain differences. Despite these genetic differences, C. orbiculata endosymbionts shared a high number of metabolic functions, including highly expressed thioautotrophy-related genes and a moderately to weakly expressed conserved one-carbon (C1) oxidation gene cluster previously undescribed in lucinid symbionts. Few symbiont- and host-related genes, including those encoding symbiotic sulfurtransferase, host respiratory functions, and host sulfide oxidation functions, were differentially expressed between seagrass- and alga-covered sediment locations. In contrast to previous studies, the identification of multiple endosymbiont taxa within and across C. orbiculata individuals, which were also shared with other sympatric lucinid species, suggests that neither host nor endosymbiont displays strict taxonomic specificity. This necessitates further investigations into the nature and extent of specificity of lucinid hosts and their symbionts.IMPORTANCE Symbiont diversity and host/symbiont functions have been comprehensively profiled for only a few lucinid species. In this work, unprecedented thioautotrophic gill endosymbiont taxonomic diversity was characterized within a Ctena orbiculata population associated with both seagrass- and alga-covered sediments. Endosymbiont metabolisms included known chemosynthetic functions and an additional conserved, previously uncharacterized C1 oxidation pathway. Lucinid-symbiont associations were not species specific because this C. orbiculata population hosted multiple endosymbiont strains and species, and other sympatric lucinid species shared overlapping symbiont 16S rRNA gene diversity profiles with C. orbiculata Our results suggest that lucinid-symbiont association patterns within some host species could be more taxonomically diverse than previously thought. As such, this study highlights the importance of holistic analyses, at the population, community, and even ecosystem levels, in understanding host-microbe association patterns.}, }
@article {pmid31448151, year = {2019}, author = {Yoder, JA and Rodell, BM and Klever, LA and Dobrotka, CJ and Pekins, PJ}, title = {Vertical transmission of the entomopathogenic soil fungus Scopulariopsis brevicaulis as a contaminant of eggs in the winter tick, Dermacentor albipictus, collected from calf moose (New Hampshire, USA).}, journal = {Mycology}, volume = {10}, number = {3}, pages = {174-181}, pmid = {31448151}, issn = {2150-1203}, abstract = {Moose naturally acquire soil fungi on their fur that are entomopathogenic to the winter tick, Dermacentor albipictus. Presumed to provide a measure of on-host tick control, it is unknown whether these soil fungi impact subsequent off-host stages of the tick. Eggs and resultant larvae originating from engorged, adult female winter ticks collected from dead calf moose (Alces alces) were used to investigate the presence and extent of fungal infection. Approximately 40% of eggs and larvae were infected, almost exclusively by the fungus Scopulariopsis brevicaulis (teleomorph Microascus brevicaulis: Microascaceae, Ascomycota). Eggs analysed on the day of oviposition and day of hatching had high frequency (40%) of S. brevicaulis, whereas the frequency in eggs harvested in utero was minimal (7%); therefore, exposure occurs pre-oviposition in the female's genital chamber, not by transovarial transmission. At hatching, larvae emerge containing S. brevicaulis indicating transstadial transmission. Artificial infection by topical application of eggs and larvae with a large inoculum of S. brevicaulis spores caused rapid dehydration, marked mortality; pathogenicity was confirmed by Koch's postulates. The high hatching success (>90%) and multi-month survival of larvae imply that S. brevicaulis is maintained as a natural pathobiont in winter ticks.}, }
@article {pmid31442887, year = {2019}, author = {Genchi, M and Vismarra, A and Lucchetti, C and Viglietti, A and Crosara, S and Gnudi, G and Quintavalla, C and Schaper, R and Kramer, L}, title = {Efficacy of imidacloprid 10%/moxidectin 2.5% spot on (Advocate®, Advantage Multi®) and doxycycline for the treatment of natural Dirofilaria immitis infections in dogs.}, journal = {Veterinary parasitology}, volume = {273}, number = {}, pages = {11-16}, doi = {10.1016/j.vetpar.2019.07.011}, pmid = {31442887}, issn = {1873-2550}, mesh = {Animals ; Antigens, Helminth/blood ; Arsenicals/therapeutic use ; Dirofilaria immitis ; Dirofilariasis/*drug therapy ; Dog Diseases/drug therapy ; Dogs ; Doxycycline/*therapeutic use ; Drug Therapy, Combination ; Female ; Filaricides/therapeutic use ; Macrolides/*therapeutic use ; Male ; Neonicotinoids/*therapeutic use ; Nitro Compounds/*therapeutic use ; Time Factors ; Treatment Outcome ; Triazines/therapeutic use ; }, abstract = {Heartworm infection (also known as dirofilariosis due to Dirofilaria immitis) in dogs causes chronic pulmonary disease that, if left untreated, can lead to right-side congestive heart failure. Currently, the only registered drug for adulticide therapy in dogs with heartworm disease (HWD) is melarsomine dihydrochloride. The recent targeting of the bacterial endosymbiont Wolbachia, through antibiotic therapy of the infected host, has offered an interesting alternative for the treatment of HWD. Recent reports of the adulticide activity of an ivermectin/doxycycline combination protocol has lead the American Heartworm Society (AHS) to include in its guidelines that, in cases where arsenical therapy is not possible or is contraindicated, a monthly heartworm preventive along with doxycycline for a 4-week period might be considered. In the present study, 20 dogs with confirmed natural D. immitis infection were included following owner consent. Fourteen dogs were treated with a topical formulation containing 10% w/v imidacloprid and 2.5% w/v moxidectin (Advocate®, Advantage Multi®, Bayer), monthly for nine months, associated to doxycycline (10 mg/kg/BID) for the first 30 days. Six dogs were treated with melarsomine (Immiticide®, Merial) (2.5 mg/kg) at enrollment, followed one month later by two injections 24 h apart. The presence of circulating antigens and the number of microfilariae (mf) were evaluated at the moment of enrollment and then at 1, 2, 3, 4, 5, 6, 7, 8, 12, 18, 24 months post enrollment. Echocardiogram and radiographs were performed at month 0, 6, 12, 18, 24. Monthly moxidectin combined with 30 days of doxycycline eliminated circulating microfilariae within one month, thus breaking the transmission cycle very quickly. Furthermore, dogs treated with the combination protocol started to become negative for circulating antigens at 4 months from the beginning of treatment and all except one were antigen negative at 9 months. All dogs treated with melarsomine were antigen negative by 5 months from the beginning of the treatment. No dogs showed worsening of pulmonary patterns or criteria indicative of pulmonary hypertension 12 to 24 months after. For the criteria mf concentration, antigen concentration, radiography and echocardiography at 12, 18 and 24 months the non-inferiority for the moxidectin group could be proven for a non-inferiority margin of 15% for the rate difference. Dogs treated with moxidectin and doxycycline became negative for microfilariae and antigens sooner when compared to melarsomine in the present study and to dogs treated with doxycycline combined with ivermectin in studies previously published.}, }
@article {pmid31438811, year = {2019}, author = {Hammer, TJ and Moran, NA}, title = {Links between metamorphosis and symbiosis in holometabolous insects.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {374}, number = {1783}, pages = {20190068}, pmid = {31438811}, issn = {1471-2970}, support = {R01 GM108477/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Insecta/growth &amp; development/microbiology/parasitology ; Larva/growth &amp; development/microbiology/parasitology ; *Metamorphosis, Biological ; *Microbiota ; *Symbiosis ; }, abstract = {Many animals depend on microbial symbionts to provide nutrition, defence or other services. Holometabolous insects, as well as other animals that undergo metamorphosis, face unique constraints on symbiont maintenance. Microbes present in larvae encounter a radical transformation of their habitat and may also need to withstand chemical and immunological challenges. Metamorphosis also provides an opportunity, in that symbiotic associations can be decoupled over development. For example, some holometabolous insects maintain the same symbiont as larvae and adults, but house it in different tissues; in other species, larvae and adults may harbour entirely different types or numbers of microbes, in accordance with shifts in host diet or habitat. Such flexibility may provide an advantage over hemimetabolous insects, in which selection on adult-stage microbial associations may be constrained by its negative effects on immature stages, and vice versa. Additionally, metamorphosis itself can be directly influenced by symbionts. Across disparate insect taxa, microbes protect hosts from pathogen infection, supply nutrients essential for rebuilding the adult body and provide cues regulating pupation. However, microbial associations remain completely unstudied for many families and even orders of Holometabola, and future research will undoubtedly reveal more links between metamorphosis and microbiota, two widespread features of animal life. This article is part of the theme issue 'The evolution of complete metamorphosis'.}, }
@article {pmid31432763, year = {2019}, author = {Charlesworth, J and Weinert, LA and Araujo, EV and Welch, JJ}, title = {Wolbachia, Cardinium and climate: an analysis of global data.}, journal = {Biology letters}, volume = {15}, number = {8}, pages = {20190273}, pmid = {31432763}, issn = {1744-957X}, support = {109385/Z/15/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Arthropods ; Bacteroidetes ; Insecta ; Symbiosis ; *Wolbachia ; }, abstract = {Bacterial endosymbionts are very common in terrestrial arthropods, but infection levels vary widely among populations. Experiments and within-species comparisons suggest that environmental temperature might be important in explaining this variation. To investigate the importance of temperature, at broad geographical and taxonomic scales, we extended a global database of terrestrial arthropods screened for Wolbachia and Cardinium. Our final dataset contained data from more than 117 000 arthropods (over 2500 species) screened for Wolbachia and more than 18 000 arthropods (over 800 species) screened for Cardinium, including samples from 137 different countries, with mean temperatures varying from -6.5 to 29.2°C. In insects and relatives, Cardinium infection showed a clear and consistent tendency to increase with temperature. For Wolbachia, a tendency to increase with temperature in temperate climates is counteracted by reduced prevalence in the tropics, resulting in a weak negative trend overall. We discuss the implications of these results for natural and introduced symbionts in regions affected by climate change.}, }
@article {pmid31430401, year = {2019}, author = {Mathé-Hubert, H and Kaech, H and Hertaeg, C and Jaenike, J and Vorburger, C}, title = {Nonrandom associations of maternally transmitted symbionts in insects: The roles of drift versus biased cotransmission and selection.}, journal = {Molecular ecology}, volume = {28}, number = {24}, pages = {5330-5346}, doi = {10.1111/mec.15206}, pmid = {31430401}, issn = {1365-294X}, mesh = {Animals ; Aphids/*genetics/microbiology ; Bayes Theorem ; Drosophila/genetics/microbiology ; Gene Transfer, Horizontal/genetics ; Maternal Inheritance/genetics ; Microbiota/genetics ; Phylogeny ; Spiroplasma/*genetics ; Symbiosis/*genetics ; Wolbachia/*genetics ; }, abstract = {Virtually all higher organisms form holobionts with associated microbiota. To understand the biology of holobionts we need to know how species assemble and interact. Controlled experiments are suited to study interactions between particular symbionts, but they only accommodate a tiny portion of the diversity within each species. Alternatively, interactions can be inferred by testing if associations among symbionts in the field are more or less frequent than expected under random assortment. However, random assortment may not be a valid null hypothesis for maternally transmitted symbionts since drift alone can result in associations. Here, we analyse a European field survey of endosymbionts in pea aphids (Acyrthosiphon pisum), confirming that symbiont associations are pervasive. To interpret them, we develop a model simulating the effect of drift on symbiont associations. We show that drift induces apparently nonrandom assortment, even though horizontal transmissions and maternal transmission failures tend to randomise symbiont associations. We also use this model in the approximate Bayesian computation framework to revisit the association between Spiroplasma and Wolbachia in Drosophila neotestacea. New field data reported here reveal that this association has disappeared in the investigated location, yet a significant interaction between Spiroplasma and Wolbachia can still be inferred. Our study confirms that negative and positive associations are pervasive and often induced by symbiont-symbiont interactions. Nevertheless, some associations are also likely to be driven by drift. This possibility needs to be considered when performing such analyses, and our model is helpful for this purpose.}, }
@article {pmid31427512, year = {2019}, author = {Hehenberger, E and Gast, RJ and Keeling, PJ}, title = {A kleptoplastidic dinoflagellate and the tipping point between transient and fully integrated plastid endosymbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {36}, pages = {17934-17942}, pmid = {31427512}, issn = {1091-6490}, mesh = {Dinoflagellida/*physiology ; Electron Transport ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; *Gene Transfer, Horizontal ; Models, Biological ; *Mutagenesis, Insertional ; Plastids/*genetics ; *Symbiosis ; }, abstract = {Plastid endosymbiosis has been a major force in the evolution of eukaryotic cellular complexity, but how endosymbionts are integrated is still poorly understood at a mechanistic level. Dinoflagellates, an ecologically important protist lineage, represent a unique model to study this process because dinoflagellate plastids have repeatedly been reduced, lost, and replaced by new plastids, leading to a spectrum of ages and integration levels. Here we describe deep-transcriptomic analyses of the Antarctic Ross Sea dinoflagellate (RSD), which harbors long-term but temporary kleptoplasts stolen from haptophyte prey, and is closely related to dinoflagellates with fully integrated plastids derived from different haptophytes. In some members of this lineage, called the Kareniaceae, their tertiary haptophyte plastids have crossed a tipping point to stable integration, but RSD has not, and may therefore reveal the order of events leading up to endosymbiotic integration. We show that RSD has retained its ancestral secondary plastid and has partitioned functions between this plastid and the kleptoplast. It has also obtained genes for kleptoplast-targeted proteins via horizontal gene transfer (HGT) that are not derived from the kleptoplast lineage. Importantly, many of these HGTs are also found in the related species with fully integrated plastids, which provides direct evidence that genetic integration preceded organelle fixation. Finally, we find that expression of kleptoplast-targeted genes is unaffected by environmental parameters, unlike prey-encoded homologs, suggesting that kleptoplast-targeted HGTs have adapted to posttranscriptional regulation mechanisms of the host.}, }
@article {pmid31422731, year = {2019}, author = {Wari, D and Alamgir, KM and Mujiono, K and Hojo, Y and Tani, A and Shinya, T and Nakatani, H and Galis, I}, title = {Brown planthopper honeydew-associated symbiotic microbes elicit momilactones in rice.}, journal = {Plant signaling &amp; behavior}, volume = {14}, number = {11}, pages = {1655335}, pmid = {31422731}, issn = {1559-2324}, mesh = {Animals ; Cucumis melo/*microbiology/*parasitology ; Diterpenes/*metabolism ; Hemiptera/*physiology ; Lactones/*metabolism ; Oryza/*microbiology/*parasitology ; Plant Leaves/metabolism ; *Symbiosis ; }, abstract = {Plants use many natural products to counter pests and diseases in nature. In rice, direct defense mechanisms include broad range of secondary metabolites, such as phenolamides (PA), diterpene phytoalexins, and flavonoid sakuranetin. Recently, accumulation of PAs in rice was shown to be under control of microbial symbionts in honeydew (HD), digestive waste from the rice brown planthopper (Nilaparvata lugens; BPH), but whether HD microbiota can also promote diterpene phytoalexins, momilactone A (MoA) and MoB, has not been reported. Here, we demonstrate that crude HD, but not a filtered one, induces MoA and MoB in rice, suggesting the involvement of BPH-HD endosymbionts. Consequently, microbial strains previously isolated from HD could promote MoA and MoB levels in wounded rice leaves, suggesting that rice indeed responds to BPH by cumulative chemical defense that involves both PA and diterpene phytoalexin pathways.}, }
@article {pmid31419116, year = {2019}, author = {Mehta, AP and Ko, Y and Supekova, L and Pestonjamasp, K and Li, J and Schultz, PG}, title = {Toward a Synthetic Yeast Endosymbiont with a Minimal Genome.}, journal = {Journal of the American Chemical Society}, volume = {141}, number = {35}, pages = {13799-13802}, pmid = {31419116}, issn = {1520-5126}, support = {R01 GM132071/GM/NIGMS NIH HHS/United States ; }, mesh = {Escherichia coli/genetics/*metabolism ; Mitochondria/metabolism ; Saccharomyces cerevisiae/genetics/*metabolism ; *Symbiosis/genetics ; }, abstract = {Based on the endosymbiotic theory, one of the key events that occurred during mitochondrial evolution was an extensive loss of nonessential genes from the protomitochondrial endosymbiont genome and transfer of some of the essential endosymbiont genes to the host nucleus. We have developed an approach to recapitulate various aspects of endosymbiont genome minimization using a synthetic system consisting of Escherichia coli endosymbionts within host yeast cells. As a first step, we identified a number of E. coli auxotrophs of central metabolites that can form viable endosymbionts within yeast cells. These studies provide a platform to identify nonessential biosynthetic pathways that can be deleted in the E. coli endosymbionts to investigate the evolutionary adaptations in the host and endosymbiont during the evolution of mitochondria.}, }
@article {pmid31417112, year = {2019}, author = {Lorenzo-Carballa, MO and Torres-Cambas, Y and Heaton, K and Hurst, GDD and Charlat, S and Sherratt, TN and Van Gossum, H and Cordero-Rivera, A and Beatty, CD}, title = {Widespread Wolbachia infection in an insular radiation of damselflies (Odonata, Coenagrionidae).}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {11933}, pmid = {31417112}, issn = {2045-2322}, mesh = {Alleles ; Animals ; Bayes Theorem ; *Biological Evolution ; Fiji ; Geography ; Gram-Negative Bacterial Infections/*microbiology ; Host-Pathogen Interactions ; Multilocus Sequence Typing ; Odonata/*microbiology ; Phylogeny ; Wolbachia/classification/*physiology ; }, abstract = {Wolbachia is one of the most common endosymbionts found infecting arthropods. Theory predicts symbionts like Wolbachia will be more common in species radiations, as host shift events occur with greatest frequency between closely related species. Further, the presence of Wolbachia itself may engender reproductive isolation, and promote speciation of their hosts. Here we screened 178 individuals belonging to 30 species of the damselfly genera Nesobasis and Melanesobasis - species radiations endemic to the Fiji archipelago in the South Pacific - for Wolbachia, using multilocus sequence typing to characterize bacterial strains. Incidence of Wolbachia was 71% in Nesobasis and 40% in Melanesobasis, and prevalence was also high, with an average of 88% in the Nesobasis species screened. We identified a total of 25 Wolbachia strains, belonging to supergroups A, B and F, with some epidemic strains present in multiple species. The occurrence of Wolbachia in both males and females, and the similar global prevalence found in both sexes rules out any strong effect of Wolbachia on the primary sex-ratio, but are compatible with the phenotype of cytoplasmic incompatibility. Nesobasis has higher species richness than most endemic island damselfly genera, and we discuss the potential for endosymbiont-mediated speciation within this group.}, }
@article {pmid31416937, year = {2019}, author = {Youle, RJ}, title = {Mitochondria-Striking a balance between host and endosymbiont.}, journal = {Science (New York, N.Y.)}, volume = {365}, number = {6454}, pages = {}, doi = {10.1126/science.aaw9855}, pmid = {31416937}, issn = {1095-9203}, mesh = {Animals ; DNA, Mitochondrial/immunology ; Host Microbial Interactions/*immunology ; Humans ; *Immunity, Innate ; Mitochondria/genetics/*immunology ; Mitophagy/immunology ; Symbiosis/*immunology ; }, abstract = {Mitochondria are organelles with their own genome that arose from α-proteobacteria living within single-celled Archaea more than a billion years ago. This step of endosymbiosis offered tremendous opportunities for energy production and metabolism and allowed the evolution of fungi, plants, and animals. However, less appreciated are the downsides of this endosymbiosis. Coordinating gene expression between the mitochondrial genomes and the nuclear genome is imprecise and can lead to proteotoxic stress. The clonal reproduction of mitochondrial DNA requires workarounds to avoid mutational meltdown. In metazoans that developed innate immune pathways to thwart bacterial and viral infections, mitochondrial components can cross-react with pathogen sensors and invoke inflammation. Here, I focus on the numerous and elegant quality control processes that compensate for or mitigate these challenges of endosymbiosis.}, }
@article {pmid31411007, year = {2020}, author = {Zhu, YX and Song, ZR and Song, YL and Zhao, DS and Hong, XY}, title = {The microbiota in spider mite feces potentially reflects intestinal bacterial communities in the host.}, journal = {Insect science}, volume = {27}, number = {5}, pages = {859-868}, doi = {10.1111/1744-7917.12716}, pmid = {31411007}, issn = {1744-7917}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Feces/microbiology ; Gastrointestinal Microbiome ; *Host Microbial Interactions ; Microbiota/*physiology ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; *Symbiosis ; Tetranychidae/*microbiology ; }, abstract = {Microorganisms provide many physiological functions to herbivorous hosts. Spider mites (genus Tetranychus) are important agricultural pests throughout the world; however, the composition of the spider mite microbial community, especially gut microbiome, remains unclear. Here, we investigated the bacterial community in five spider mite species and their associated feces by deep sequencing of the 16S rRNA gene. The composition of the bacterial community was significantly different among the five prevalent spider mite species, and some bacterial symbionts showed host-species specificity. Moreover, the abundance of the bacterial community in spider mite feces was significantly higher than that in the corresponding spider mite samples. However, Flavobacterium was detected in all samples, and represent a "core microbiome". Remarkably, the maternally inherited endosymbiont Wolbachia was detected in both spider mite and feces. Overall, these results offer insight into the complex community of symbionts in spider mites, and give a new direction for future studies.}, }
@article {pmid31409870, year = {2019}, author = {Swe, PM and Zakrzewski, M and Waddell, R and Sriprakash, KS and Fischer, K}, title = {High-throughput metagenome analysis of the Sarcoptes scabiei internal microbiota and in-situ identification of intestinal Streptomyces sp.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {11744}, pmid = {31409870}, issn = {2045-2322}, mesh = {Animals ; Feces/microbiology ; Female ; *Gastrointestinal Microbiome ; High-Throughput Nucleotide Sequencing ; In Situ Hybridization, Fluorescence ; *Metagenome ; *Metagenomics/methods ; *Microbiota ; Sarcoptes scabiei/*microbiology ; Sodium Hypochlorite/pharmacology ; Streptomyces/*genetics ; }, abstract = {Multiple parasitic arthropods of medical importance depend on symbiotic bacteria. While the link between scabies and secondary bacterial infections causing post infective complications of Group A streptococcal and staphylococcal pyoderma is increasingly recognized, very little is known about the microbiota of Sarcoptes scabiei. Here we analyze adult female mite and egg metagenome datasets. The majority of adult mite bacterial reads matched with Enterobacteriaceae (phylum Proteobacteria), followed by Corynebacteriaceae (phylum Actinobacteria). Klebsiella was the most dominant genus (78%) and Corynebacterium constituted 9% of the assigned sequences. Scabies mite eggs had a more diverse microbial composition with sequences from Proteobacteria being the most dominant (75%), while Actinobacteria, Bacteroidetes and Firmicutes accounted for 23% of the egg microbiome sequences. DNA sequences of a potential endosymbiont, namely Streptomyces, were identified in the metagenome sequence data of both life stages. The presence of Streptomyces was confirmed by conventional PCR. Digital droplet PCR indicated higher Streptomyces numbers in adult mites compared to eggs. Streptomyces were localized histologically in the scabies mite gut and faecal pellets by Fluorescent In Situ Hybridization (FISH). Streptomyces may have essential symbiotic roles in the scabies parasite intestinal system requiring further investigation.}, }
@article {pmid31409030, year = {2019}, author = {Meron, D and Maor-Landaw, K and Weizman, E and Waldman Ben-Asher, H and Eyal, G and Banin, E and Loya, Y and Levy, O}, title = {The Algal Symbiont Modifies the Transcriptome of the Scleractinian Coral Euphyllia paradivisa During Heat Stress.}, journal = {Microorganisms}, volume = {7}, number = {8}, pages = {}, pmid = {31409030}, issn = {2076-2607}, abstract = {The profound mutualistic symbiosis between corals and their endosymbiotic counterparts, Symbiodiniaceae algae, has been threatened by the increase in seawater temperatures, leading to breakdown of the symbiotic relationship-coral bleaching. To characterize the heat-stress response of the holobiont, we generated vital apo-symbiotic Euphylliaparadivisa corals that lacked the endosymbiotic algae. Using RNA sequencing, we analyzed the gene expression of these apo-symbionts vs. symbiotic ones, to test the effect of the algal presence on the tolerance of the coral. We utilized literature-derived lists of "symbiosis differentially expressed genes" and "coral heat-stress genes" in order to compare between the treatments. The symbiotic and apo-symbiotic samples were segregated into two separate groups with several different enriched gene ontologies. Our findings suggest that the presence of endosymbionts has a greater negative impact on the host than the environmental temperature conditions experienced by the holobiont. The peak of the stress reaction was identified as 28 °C, with the highest number of differentially expressed genes. We suggest that the algal symbionts increase coral holobiont susceptibility to elevated temperatures. Currently, we can only speculate whether coral species, such as E.paradivisa, with the plasticity to also flourish as apo-symbionts, may have a greater chance to withstand the upcoming global climate change challenge.}, }
@article {pmid31407021, year = {2020}, author = {Bockoven, AA and Bondy, EC and Flores, MJ and Kelly, SE and Ravenscraft, AM and Hunter, MS}, title = {What Goes Up Might Come Down: the Spectacular Spread of an Endosymbiont Is Followed by Its Decline a Decade Later.}, journal = {Microbial ecology}, volume = {79}, number = {2}, pages = {482-494}, pmid = {31407021}, issn = {1432-184X}, mesh = {Animals ; Arizona ; Genetic Fitness ; Hemiptera/genetics/*microbiology/*physiology ; *Microbiota ; Rickettsia/*physiology ; Sex Ratio ; *Symbiosis ; }, abstract = {Facultative, intracellular bacterial symbionts of arthropods may dramatically affect host biology and reproduction. The length of these symbiont-host associations may be thousands to millions of years, and while symbiont loss is predicted, there have been very few observations of a decline of symbiont infection rates. In a population of the sweet potato whitefly species (Bemisia tabaci MEAM1) in Arizona, USA, we documented the frequency decline of a strain of Rickettsia in the Rickettsia bellii clade from near-fixation in 2011 to 36% of whiteflies infected in 2017. In previous studies, Rickettsia had been shown to increase from 1 to 97% from 2000 to 2006 and remained at high frequency for at least five years. At that time, Rickettsia infection was associated with both fitness benefits and female bias. In the current study, we established matrilines of whiteflies from the field (2016, Rickettsia infection frequency = 58%) and studied (a) Rickettsia vertical transmission, (b) fitness and sex ratios associated with Rickettsia infection, (c) symbiont titer, and (d) bacterial communities within whiteflies. The vertical transmission rate was high, approximately 98%. Rickettsia infection in the matrilines was not associated with fitness benefits or sex ratio bias and appeared to be slightly costly, as more Rickettsia-infected individuals produced non-hatching eggs. Overall, the titer of Rickettsia in the matrilines was lower in 2016 than in the whiteflies collected in 2011, but the titer distribution appeared bimodal, with high- and low-titer lines, and constancy of the average titer within lines over three generations. We found neither association between Rickettsia titer and fitness benefits or sex ratio bias nor evidence that Rickettsia was replaced by another secondary symbiont. The change in the interaction between symbiont and host in 2016 whiteflies may explain the drop in symbiont frequency we observed.}, }
@article {pmid31397213, year = {2019}, author = {Serra, V and Krey, V and Daschkin, C and Cafiso, A and Sassera, D and Maxeiner, HG and Modeo, L and Nicolaus, C and Bandi, C and Bazzocchi, C}, title = {Seropositivity to Midichloria mitochondrii (order Rickettsiales) as a marker to determine the exposure of humans to tick bite.}, journal = {Pathogens and global health}, volume = {113}, number = {4}, pages = {167-172}, pmid = {31397213}, issn = {2047-7732}, mesh = {Animals ; Antibodies, Bacterial/*blood ; Bacterial Proteins/*immunology ; Enzyme-Linked Immunosorbent Assay ; Europe/epidemiology ; Feeding Behavior ; Female ; Humans ; Ixodes/microbiology/*physiology ; Male ; Rickettsiales/*immunology ; Seroepidemiologic Studies ; Tick Bites/*diagnosis/epidemiology ; }, abstract = {Ixodes ricinus is the most common tick species parasitizing humans in Europe, and the main vector of Borrelia burgdorferi sensu lato, the causative agent of Lyme disease in the continent. This tick species also harbors the endosymbiont Midichloria mitochondrii, and there is strong evidence that this bacterium is inoculated into the vertebrate host during the blood meal. A high proportion of tick bites remains unnoticed due to rarity of immediate symptoms, implying the risk of occult tick-borne infections in turn a potential risk factor for the onset of chronic-degenerative diseases. Since suitable tools to determine the previous exposure to I. ricinus bites are needed, this work investigated whether seropositivity toward a protein of M. mitochondrii (rFliD) could represent a marker for diagnosis of I. ricinus bite. We screened 274 sera collected from patients from several European countries, at different risk of tick bite, using an ELISA protocol. Our results show a clear trend indicating that positivity to rFliD is higher where the tick bite can be regarded as certain/almost certain, and lower where there is an uncertainty on the bite, with the highest positivity in Lyme patients (47.30%) and the lowest (2.00%) in negative controls. According to the obtained results, M. mitochondrii can be regarded as a useful source of antigens, with the potential to be used to assess the exposure to ticks harboring this bacterium. In prospect, additional antigens from M. mitochondrii and tick salivary glands should be investigated and incorporated in a multi-antigen test for tick bite diagnosis.}, }
@article {pmid31396178, year = {2019}, author = {Trappeniers, K and Matetovici, I and Van Den Abbeele, J and De Vooght, L}, title = {The Tsetse Fly Displays an Attenuated Immune Response to Its Secondary Symbiont, Sodalis glossinidius.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {1650}, pmid = {31396178}, issn = {1664-302X}, abstract = {Sodalis glossinidius, a vertically transmitted facultative symbiont of the tsetse fly, is a bacterium in the early/intermediate state of its transition toward symbiosis, representing an important model for investigating how the insect host immune defense response is regulated to allow endosymbionts to establish a chronic infection within their hosts without being eliminated. In this study, we report on the establishment of a tsetse fly line devoid of S. glossinidius only, allowing us to experimentally investigate (i) the complex immunological interactions between a single bacterial species and its host, (ii) how the symbiont population is kept under control, and (iii) the impact of the symbiont on the vector competence of the tsetse fly to transmit the sleeping sickness parasite. Comparative transcriptome analysis showed no difference in the expression of genes involved in innate immune processes between symbiont-harboring (Gmm [Sod+]) and S. glossinidius-free (Gmm [Sod-]) flies. Re-exposure of (Gmm [Sod-]) flies to the endosymbiotic bacterium resulted in a moderate immune response, whereas exposure to pathogenic E. coli or to a close non-insect associated relative of S. glossinidius, i.e., S. praecaptivus, resulted in full immune activation. We also showed that S. glossinidius densities are not affected by experimental activation or suppression of the host immune system, indicating that S. glossinidius is resistant to mounted immune attacks and that the host immune system does not play a major role in controlling S. glossinidius proliferation. Finally, we demonstrate that the absence or presence of S. glossinidius in the tsetse fly does not alter its capacity to mount an immune response to pathogens nor does it affect the fly's susceptibility toward trypanosome infection.}, }
@article {pmid31396100, year = {2019}, author = {Liu, L and Zhang, KJ and Rong, X and Li, YY and Liu, H}, title = {Identification of Wolbachia-Responsive miRNAs in the Small Brown Planthopper, Laodelphax striatellus.}, journal = {Frontiers in physiology}, volume = {10}, number = {}, pages = {928}, pmid = {31396100}, issn = {1664-042X}, abstract = {Laodelphax striatellus is naturally infected with the Wolbachia strain wStri, which induces strong cytoplasmic incompatibility of its host. MicroRNAs (miRNAs) are a class of endogenous non-coding small RNAs that play a critical role in the regulation of gene expression at post-transcriptional level in various biological processes. Despite various studies reporting that Wolbachia affects the miRNA expression of their hosts, the molecular mechanism underlying interactions between Wolbachia and their host miRNAs has not been well understood. In order to better understand the impact of Wolbachia infection on its host, we investigated the differentially expressed miRNAs between Wolbachia-infected and Wolbachia-uninfected strains of L. striatellus. Compared with uninfected strains, Wolbachia infection resulted in up-regulation of 18 miRNAs and down-regulation of 6 miRNAs in male, while 25 miRNAs were up-regulated and 15 miRNAs were down-regulated in female. The target genes of these differentially expressed miRNAs involved in immune response regulation, reproduction, redox homeostasis and ecdysteroidogenesis were also annotated in both sexes. We further verified the expression of several significantly differentially expressed miRNAs and their predicted target genes by qRT-PCR method. The results suggested that Wolbachia appears to reduce the expression of genes related to fertility in males and increase the expression of genes related to fecundity in females. At the same time, Wolbachia may enhance the expression of immune-related genes in both sexes. All of the results in this study may be helpful in further exploration of the molecular mechanisms by which Wolbachia affects on its hosts.}, }
@article {pmid31388025, year = {2019}, author = {Lanzoni, O and Plotnikov, A and Khlopko, Y and Munz, G and Petroni, G and Potekhin, A}, title = {The core microbiome of sessile ciliate Stentor coeruleus is not shaped by the environment.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {11356}, pmid = {31388025}, issn = {2045-2322}, mesh = {Bacteria/*isolation &amp; purification ; Ciliophora/*microbiology ; DNA Barcoding, Taxonomic ; *Environment ; *Microbiota ; RNA, Ribosomal, 16S ; Sewage/*microbiology ; }, abstract = {Microbiomes of multicellular organisms are one of the hottest topics in microbiology and physiology, while only few studies addressed bacterial communities associated with protists. Protists are widespread in all environments and can be colonized by plethora of different bacteria, including also human pathogens. The aim of this study was to characterize the prokaryotic community associated with the sessile ciliate Stentor coeruleus. 16S rRNA gene metabarcoding was performed on single cells of S. coeruleus and on their environment, water from the sewage stream. Our results showed that the prokaryotic community composition differed significantly between Stentor cells and their environment. The core microbiome common for all ciliate specimens analyzed could be defined, and it was composed mainly by representatives of bacterial genera which include also potential human pathogens and commensals, such as Neisseria, Streptococcus, Capnocytophaga, Porphyromonas. Numerous 16S rRNA gene contigs belonged to endosymbiont "Candidatus Megaira polyxenophila". Our data suggest that each ciliate cell can be considered as an ecological microniche harboring diverse prokaryotic organisms. Possible benefits for persistence and transmission in nature for bacteria associated with protists are discussed. Our results support the hypothesis that ciliates attract potentially pathogenic bacteria and play the role of natural reservoirs for them.}, }
@article {pmid31382604, year = {2019}, author = {Nobre, T}, title = {Symbiosis in Sustainable Agriculture: Can Olive Fruit Fly Bacterial Microbiome Be Useful in Pest Management?.}, journal = {Microorganisms}, volume = {7}, number = {8}, pages = {}, pmid = {31382604}, issn = {2076-2607}, abstract = {The applied importance of symbiosis has been gaining recognition. The relevance of symbiosis has been increasing in agriculture, in developing sustainable practices, including pest management. Insect symbiotic microorganisms' taxonomical and functional diversity is high, and so is the potential of manipulation of these microbial partners in suppressing pest populations. These strategies, which rely on functional organisms inhabiting the insect, are intrinsically less susceptible to external environmental variations and hence likely to overcome some of the challenges posed by climate change. Rates of climate change in the Mediterranean Basin are expected to exceed global trends for most variables, and this warming will also affect olive production and impact the interactions of olives and their main pest, the obligate olive fruit fly (Bactrocera oleae). This work summarizes the current knowledge on olive fly symbiotic bacteria towards the potential development of symbiosis-based strategies for olive fruit fly control. Particular emphasis is given to Candidatus Erwinia dacicola, an obligate, vertically transmitted endosymbiont that allows the insect to cope with the olive-plant produced defensive compound oleuropein, as a most promising target for a symbiosis disruption approach.}, }
@article {pmid31381563, year = {2019}, author = {Hübner, MP and Koschel, M and Struever, D and Nikolov, V and Frohberger, SJ and Ehrens, A and Fendler, M and Johannes, I and von Geldern, TW and Marsh, K and Turner, JD and Taylor, MJ and Ward, SA and Pfarr, K and Kempf, DJ and Hoerauf, A}, title = {In vivo kinetics of Wolbachia depletion by ABBV-4083 in L. sigmodontis adult worms and microfilariae.}, journal = {PLoS neglected tropical diseases}, volume = {13}, number = {8}, pages = {e0007636}, pmid = {31381563}, issn = {1935-2735}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Doxycycline/pharmacology ; Female ; Filariasis ; Filarioidea/drug effects/*microbiology ; Gerbillinae ; Kinetics ; Mice ; Mice, Inbred BALB C ; Microfilariae/drug effects/embryology/*microbiology ; Models, Animal ; Wolbachia/*drug effects/*physiology ; }, abstract = {Depletion of Wolbachia endosymbionts of human pathogenic filariae using 4-6 weeks of doxycycline treatment can lead to permanent sterilization and adult filarial death. We investigated the anti-Wolbachia drug candidate ABBV-4083 in the Litomosoides sigmodontis rodent model to determine Wolbachia depletion kinetics with different regimens. Wolbachia reduction occurred in mice as early as 3 days after the initiation of ABBV-4083 treatment and continued throughout a 10-day treatment period. Importantly, Wolbachia levels continued to decline after a 5-day-treatment from 91.5% to 99.9% during a 3-week washout period. In jirds, two weeks of ABBV-4083 treatment (100mg/kg once-per-day) caused a >99.9% Wolbachia depletion in female adult worms, and the kinetics of Wolbachia depletion were recapitulated in peripheral blood microfilariae. Similar to Wolbachia depletion, inhibition of embryogenesis was time-dependent in ABBV-4083-treated jirds, leading to a complete lack of late embryonic stages (stretched microfilariae) and lack of peripheral microfilariae in 5/6 ABBV-4083-treated jirds by 14 weeks after treatment. Twice daily treatment in comparison to once daily treatment with ABBV-4083 did not significantly improve Wolbachia depletion. Moreover, up to 4 nonconsecutive daily treatments within a 14-dose regimen did not significantly erode Wolbachia depletion. Within the limitations of an animal model that does not fully recapitulate human filarial disease, our studies suggest that Wolbachia depletion should be assessed clinically no earlier than 3-4 weeks after the end of treatment, and that Wolbachia depletion in microfilariae may be a viable surrogate marker for the depletion within adult worms. Furthermore, strict daily adherence to the dosing regimen with anti-Wolbachia candidates may not be required, provided that the full regimen is subsequently completed.}, }
@article {pmid31380084, year = {2019}, author = {Yoshida, K and Sanada-Morimura, S and Huang, SH and Tokuda, M}, title = {Influences of two coexisting endosymbionts, CI-inducing Wolbachia and male-killing Spiroplasma, on the performance of their host Laodelphax striatellus (Hemiptera: Delphacidae).}, journal = {Ecology and evolution}, volume = {9}, number = {14}, pages = {8214-8224}, pmid = {31380084}, issn = {2045-7758}, abstract = {The small brown planthopper Laodelphax striatellus (Hemiptera: Delphacidae) is reported to have the endosymbiont Wolbachia, which shows a strong cytoplasmic incompatibility (CI) between infected males and uninfected females. In the 2000s, female-biased L. striatellus populations were found in Taiwan, and this sex ratio distortion was the result of male-killing induced by the infection of another endosymbiont, Spiroplasma. Spiroplasma infection is considered to negatively affect both L. striatellus and Wolbachia because the male-killing halves the offspring of L. striatellus and hinders the spread of Wolbachia infection via CI. Spiroplasma could have traits that increase the fitness of infected L. striatellus and/or coexisting organisms because the coinfection rates of Wolbachia and Spiroplasma were rather high in some areas. In this study, we investigated the influences of the infection of these two endosymbionts on the development, reproduction, and insecticide resistance of L. striatellus in the laboratory. Our results show that the single-infection state of Spiroplasma had a negative influence on the fertility of L. striatellus, while the double-infection state had no significant influence. At late nymphal and adult stages, the abundance of Spiroplasma was lower in the double-infection state than in the single-infection state. In the double-infection state, the reduction of Spiroplasma density may be caused by competition between the two endosymbionts, and the negative influence of Spiroplasma on the fertility of host may be relieved. The resistance of L. striatellus to four insecticides was compared among different infection states of endosymbionts, but Spiroplasma infection did not contribute to increase insecticide resistance. Because positive influences of Spiroplasma infection were not found in terms of the development, reproduction, and insecticide resistance of L. striatellus, other factors improving the fitness of Spiroplasma-infected L. striatellus may be related to the high frequency of double infection in some L. striatellus populations.}, }
@article {pmid31380036, year = {2019}, author = {Su, Q and Wang, X and Ilyas, N and Zhang, F and Yun, Y and Jian, C and Peng, Y}, title = {Combined effects of elevated CO2 concentration and Wolbachia on Hylyphantes graminicola (Araneae: Linyphiidae).}, journal = {Ecology and evolution}, volume = {9}, number = {12}, pages = {7112-7121}, pmid = {31380036}, issn = {2045-7758}, abstract = {The increasing concentration of carbon dioxide in atmosphere is not only a major cause of global warming, but it also adversely affects the ecological diversity of invertebrates. This study was conducted to evaluate the effect of elevated CO2 concentration (ambient, 400 ppm and high, 800 ppm) and Wolbachia (Wolbachia-infected, W[+] and Wolbachia-uninfected, W[-]) on Hylyphantes graminicola. The total survival rate, developmental duration, carapace width and length, body weight, sex ratio, net reproductive rate, nutrition content, and enzyme activity in H. graminicola were examined under four treatments: W[-] 400 ppm, W[-] 800 ppm, W[+] 400 ppm, and W[+] 800 ppm. Results showed that Wolbachia-infected spiders had significantly decreased the total developmental duration. Different instars showed variations up to some extent, but no obvious effect was found under elevated CO2 concentration. Total survival rate, sex ratio, and net reproductive rate were not affected by elevated CO2 concentration or Wolbachia infection. The carapace width of Wolbachia-uninfected spiders decreased significantly under elevated CO2 concentration, while the width, length and weight were not significantly affected in Wolbachia-infected spiders reared at ambient CO2 concentration. The levels of protein, specific activities of peroxidase, and amylase were significantly increased under elevated CO2 concentration or Wolbachia-infected spiders, while the total amino content was only increased in Wolbachia-infected spiders. Thus, our current finding suggested that elevated CO2 concentration and Wolbachia enhance nutrient contents and enzyme activity of H. graminicola and decrease development duration hence explore the interactive effects of factors which were responsible for reproduction regulation, but it also gives a theoretical direction for spider's protection in such a dynamic environment. Increased activities of enzymes and nutrients caused by Wolbachia infection aids for better survival of H. graminicola under stress.}, }
@article {pmid31372337, year = {2019}, author = {Monnens, M and Frost, EJ and Clark, M and Sewell, MA and Vanhove, MPM and Artois, T}, title = {Description and ecophysiology of a new species of Syndesmis Silliman, 1881 (Rhabdocoela: Umagillidae) from the sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943 in New Zealand.}, journal = {International journal for parasitology. Parasites and wildlife}, volume = {10}, number = {}, pages = {71-82}, pmid = {31372337}, issn = {2213-2244}, abstract = {A new rhabdocoel of the genus Syndesmis Silliman, 1881 (Umagillidae) is described from the intestine of the New Zealand sea urchin Evechinus chloroticus (Valenciennes, 1846) Mortensen, 1943a. This new species, Syndesmis kurakaikina n. sp., is morphologically distinct and can easily be recognised by its very long (±1 mm) stylet and its bright-red colour. In addition to providing a formal description, we present some observations on reproduction and life history of this new species. Fecundity is comparable to that of other umagillids and the rate of egg production and development increases with temperature. Hatching in this species is induced by intestinal fluids of its host. Relevant to global warming, we assessed the effect of temperature on survival, fecundity, and development. The tests indicate that Syndesmis kurakaikina n. sp. is tolerant of a wide range of temperatures (11-25 °C) and that its temperature optimum lies between 18.0 and 21.5 °C. Egg viability is, however, significantly compromised at the higher end of this temperature range, with expelled egg capsules often being deformed and showing increasingly lower rates of hatching. Given this, a rise in global temperature might increase the risk of Syndesmis kurakaikina n. sp. infecting new hosts and would possibly facilitate the spread of these endosymbionts.}, }
@article {pmid31369548, year = {2019}, author = {Schneider, DI and Saarman, N and Onyango, MG and Hyseni, C and Opiro, R and Echodu, R and O'Neill, M and Bloch, D and Vigneron, A and Johnson, TJ and Dion, K and Weiss, BL and Opiyo, E and Caccone, A and Aksoy, S}, title = {Spatio-temporal distribution of Spiroplasma infections in the tsetse fly (Glossina fuscipes fuscipes) in northern Uganda.}, journal = {PLoS neglected tropical diseases}, volume = {13}, number = {8}, pages = {e0007340}, pmid = {31369548}, issn = {1935-2735}, support = {D43 TW007391/TW/FIC NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; R01 AI139525/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Coinfection ; DNA, Ribosomal/genetics ; Female ; Gram-Negative Bacterial Infections/*microbiology/*veterinary ; Insect Vectors/*microbiology/parasitology ; Male ; Prevalence ; Spiroplasma/genetics/*pathogenicity/physiology ; Symbiosis ; Trypanosoma ; Tsetse Flies/*microbiology/parasitology ; Uganda ; Wolbachia ; }, abstract = {Tsetse flies (Glossina spp.) are vectors of parasitic trypanosomes, which cause human (HAT) and animal African trypanosomiasis (AAT) in sub-Saharan Africa. In Uganda, Glossina fuscipes fuscipes (Gff) is the main vector of HAT, where it transmits Gambiense disease in the northwest and Rhodesiense disease in central, southeast and western regions. Endosymbionts can influence transmission efficiency of parasites through their insect vectors via conferring a protective effect against the parasite. It is known that the bacterium Spiroplasma is capable of protecting its Drosophila host from infection with a parasitic nematode. This endosymbiont can also impact its host's population structure via altering host reproductive traits. Here, we used field collections across 26 different Gff sampling sites in northern and western Uganda to investigate the association of Spiroplasma with geographic origin, seasonal conditions, Gff genetic background and sex, and trypanosome infection status. We also investigated the influence of Spiroplasma on Gff vector competence to trypanosome infections under laboratory conditions. Generalized linear models (GLM) showed that Spiroplasma probability was correlated with the geographic origin of Gff host and with the season of collection, with higher prevalence found in flies within the Albert Nile (0.42 vs 0.16) and Achwa River (0.36 vs 0.08) watersheds and with higher prevalence detected in flies collected in the intermediate than wet season. In contrast, there was no significant correlation of Spiroplasma prevalence with Gff host genetic background or sex once geographic origin was accounted for in generalized linear models. Additionally, we found a potential negative correlation of Spiroplasma with trypanosome infection, with only 2% of Spiroplasma infected flies harboring trypanosome co-infections. We also found that in a laboratory line of Gff, parasitic trypanosomes are less likely to colonize the midgut in individuals that harbor Spiroplasma infection. These results indicate that Spiroplasma infections in tsetse may be maintained by not only maternal but also via horizontal transmission routes, and Spiroplasma infections may also have important effects on trypanosome transmission efficiency of the host tsetse. Potential functional effects of Spiroplasma infection in Gff could have impacts on vector control approaches to reduce trypanosome infections.}, }
@article {pmid31362350, year = {2019}, author = {Satjawongvanit, H and Phumee, A and Tiawsirisup, S and Sungpradit, S and Brownell, N and Siriyasatien, P and Preativatanyou, K}, title = {Molecular Analysis of Canine Filaria and Its Wolbachia Endosymbionts in Domestic Dogs Collected from Two Animal University Hospitals in Bangkok Metropolitan Region, Thailand.}, journal = {Pathogens (Basel, Switzerland)}, volume = {8}, number = {3}, pages = {}, pmid = {31362350}, issn = {2076-0817}, abstract = {Canine filariasis is caused by several nematode species, such as Dirofilaria immitis, Dirofilaria repens, Brugia pahangi, Brugia malayi, and Acanthocheilonema reconditum. Zoonotic filariasis is one of the world's neglected tropical diseases. Since 2000, the World Health Organization (WHO) has promoted a global filarial eradication program to eliminate filariasis by 2020. Apart from vector control strategies, the infection control of reservoir hosts is necessary for more effective filariasis control. In addition, many studies have reported that Wolbachia is necessary for the development, reproduction, and survival of the filarial nematode. Consequently, the use of antibiotics to kill Wolbachia in nematodes has now become an alternative strategy to control filariasis. Previously, a case of subconjunctival dirofilariasis caused by Dirofilaria spp. has been reported in a woman who resides in the center of Bangkok, Thailand. Therefore, our study aimed to principally demonstrate the presence of filarial nematodes and Wolbachia bacteria in blood collected from domestic dogs from the Bangkok Metropolitan Region, Thailand. A total of 57 blood samples from dogs with suspected dirofilariasis who had visited veterinary clinics in Bangkok were collected. The investigations for the presence of microfilaria were carried out by using both microscopic and molecular examinations. PCR was used as the molecular detection method for the filarial nematodes based on the COI and ITS1 regions. The demonstration of Wolbachia was performed using PCR to amplify the FtsZ gene. All positive samples by PCR were then cloned and sequenced. The results showed that the filarial nematodes were detected in 16 samples (28.07%) using microscopic examinations. The molecular detection of filarial species using COI-PCR revealed that 50 samples (87.72%) were positive; these consisted of 33 (57.89%), 13 (22.81%), and 4 (7.02%) samples for D. immitis, B. pahangi, and B. malayi, respectively. While the ITS1-PCR showed that 41 samples (71.93%) were positive-30 samples (52.63%) were identified as containing D. immitis and 11 samples (19.30%) were identified to have B. pahangi, whereas B. malayi was not detected. Forty-seven samples (82.45%) were positive for Wolbachia DNA and the phylogenetic tree of all positive Wolbachia was classified into the supergroup C clade. This study has established fundamental data on filariasis associated with Wolbachia infection in domestic dogs in the Bangkok Metropolitan Region. An extensive survey of dog blood samples would provide valuable epidemiologic data on potential zoonotic filariasis in Thailand. In addition, this information could be used for the future development of more effective prevention and control strategies for canine filariasis in Thailand.}, }
@article {pmid31358202, year = {2019}, author = {Eilenberg, J and Saussure, S and Ben Fekih, I and Jensen, AB and Klingen, I}, title = {Factors driving susceptibility and resistance in aphids that share specialist fungal pathogens.}, journal = {Current opinion in insect science}, volume = {33}, number = {}, pages = {91-98}, doi = {10.1016/j.cois.2019.05.002}, pmid = {31358202}, issn = {2214-5753}, mesh = {Animals ; Aphids/*microbiology/physiology ; Entomophthorales/*pathogenicity ; Female ; Life Cycle Stages ; Poaceae ; Symbiosis ; }, abstract = {Pandora neoaphidis and Entomophthora planchoniana are widespread and important specialist fungal pathogens of aphids in cereals (Sitobion avenae and Rhopalosiphum padi). The two aphid species share these pathogens and we compare factors influencing susceptibility and resistance. Among factors that may influence susceptibility and resistance are aphid behavior, conspecific versus heterospecific host, aphid morph, life cycle, and presence of protective endosymbionts. It seems that the conspecific host is more susceptible (less resistant) than the heterospecific host, and alates are more susceptible than apterae. We conceptualize the findings in a diagram showing possible transmission in field situations and we pinpoint where there are knowledge gaps.}, }
@article {pmid31358201, year = {2019}, author = {Liu, XD and Guo, HF}, title = {Importance of endosymbionts Wolbachia and Rickettsia in insect resistance development.}, journal = {Current opinion in insect science}, volume = {33}, number = {}, pages = {84-90}, doi = {10.1016/j.cois.2019.05.003}, pmid = {31358201}, issn = {2214-5753}, mesh = {Animals ; Inactivation, Metabolic ; Insecta/*microbiology/physiology ; *Insecticide Resistance ; Insecticides/toxicity ; Rickettsia/*physiology ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Endosymbionts play important roles in protecting hosts from environmental stress, such as natural enemies, heat, and toxins. Many insects are infected with the facultative nonessential endosymbionts Wolbachia and Rickettsia, which are the crux in this review, although other relevant symbiont genera will also be treated. Insecticide resistance of hosts can be related to infections with Wolbachia and Rickettsia. These endosymbionts commonly increase host susceptibility to chemical insecticides, but cases of increased resistance also exist. The symbiont-mediated insecticide resistance/susceptibility varies with species of insect, species of symbiont, and chemical compound. Changes in insecticide resistance levels of insects can be associated with fluctuations in population density of endosymbionts. Effects of endosymbionts on host fitness, metabolism, immune system, and gene expression may determine how endosymbionts influence insecticide resistance. A clearer understanding of these interactions can improve our knowledge about drivers of decreasing insecticide resistance.}, }
@article {pmid31346538, year = {2019}, author = {Khanmohammadi, M and Falak, R and Meamar, AR and Arshadi, M and Akhlaghi, L and Razmjou, E}, title = {Molecular Detection and Phylogenetic Analysis of Endosymbiont Wolbachia pipientis (Rickettsiales: Anaplasmataceae) Isolated from Dirofilaria immitis in Northwest of Iran.}, journal = {Journal of arthropod-borne diseases}, volume = {13}, number = {1}, pages = {83-93}, pmid = {31346538}, issn = {2322-1984}, abstract = {BACKGROUND: The purpose of this study was molecular detection and phylogenetic analysis of Wolbachia species of Dirofilaria immitis.<br><br>METHODS: Adult filarial nematodes were collected from the cardiovascular and pulmonary arterial systems of naturally infected dogs, which caught in different geographical areas of Meshkin Shahr in Ardabil Province, Iran, during 2017. Dirofilaria immitis genomic DNA were extracted. Phylogenetic analysis for proofing of D. immitis was carried out using cytochrome oxidase I (COI) gene. Afterward, the purified DNA was used to determine the molecular pattern of the Wolbachia surface protein (WSP) gene sequence by PCR.<br><br>RESULTS: Phylogeny and homology studies showed high consistency of the COI gene with the previously-registered sequences for D. immitis. Comparison of DNA sequences revealed no nucleotide variation between them. PCR showed that all of the collected parasites were infected with W. pipientis. The sequence of the WSP gene in Wolbachia species from D. immitis was significantly different from other species of Dirofilaria as well as other filarial species. The maximum homology was observed with the Wolbachia isolated from D. immitis. The greatest distance between WSP nucleotides of Wolbachia species found between D. immitis and those isolated from Onchocerca lupi.<br><br>CONCLUSION: PCR could be a simple but suitable method for detection of Wolbachia species. There is a pattern of host specificity between Wolbachia and Dirofilaria that can be related to ancestral evolutions. The results of this phylogenetic analysis and molecular characterization may help us for better identification of Wolbachia species and understanding of their coevolution.}, }
@article {pmid31346439, year = {2019}, author = {Couper, LI and Kwan, JY and Ma, J and Swei, A}, title = {Drivers and patterns of microbial community assembly in a Lyme disease vector.}, journal = {Ecology and evolution}, volume = {9}, number = {13}, pages = {7768-7779}, pmid = {31346439}, issn = {2045-7758}, abstract = {Vector-borne diseases constitute a major global health burden and are increasing in geographic range and prevalence. Mounting evidence has demonstrated that the vector microbiome can impact pathogen dynamics, making the microbiome a focal point in vector-borne disease ecology. However, efforts to generalize preliminary findings across studies and systems and translate these findings into disease control strategies are hindered by a lack of fundamental understanding of the processes shaping the vector microbiome and the interactions therein. Here, we use 16S rRNA sequencing and apply a community ecology framework to analyze microbiome community assembly and interactions in Ixodes pacificus, the Lyme disease vector in the western United States. We find that vertical transmission routes drive population-level patterns in I. pacificus microbial diversity and composition, but that microbial function and overall abundance do not vary over time or between clutches. Further, we find that the I. pacificus microbiome is not strongly structured based on competition but assembles nonrandomly, potentially due to vector-specific filtering processes which largely eliminate all but the dominant endosymbiont, Rickettsia. At the scale of the individual I. pacificus, we find support for a highly limited internal microbial community, and hypothesize that the tick endosymbiont may be the most important component of the vector microbiome in influencing pathogen dynamics.}, }
@article {pmid31340757, year = {2019}, author = {He, Z and Zheng, Y and Yu, WJ and Fang, Y and Mao, B and Wang, YF}, title = {How do Wolbachia modify the Drosophila ovary? New evidences support the "titration-restitution" model for the mechanisms of Wolbachia-induced CI.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {608}, pmid = {31340757}, issn = {1471-2164}, mesh = {Animals ; Cytosol ; Drosophila melanogaster/*microbiology ; Female ; Gene Expression Regulation, Developmental ; Genes, Insect ; Male ; MicroRNAs/genetics ; Ovary/*microbiology ; RNA, Messenger/genetics ; RNA-Seq ; Testis/microbiology ; Transcriptome ; Up-Regulation ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Cytoplasmic incompatibility (CI) is the most common phenotype induced by endosymbiont Wolbachia and results in embryonic lethality when Wolbachia-modified sperm fertilize eggs without Wolbachia. However, eggs carrying the same strain of Wolbachia can rescue this embryonic death, thus producing viable Wolbachia-infected offspring. Hence Wolbachia can be transmitted mainly by hosts' eggs. One of the models explaining CI is "titration-restitution", which hypothesized that Wolbachia titrated-out some factors from the sperm and the Wolbachia in the egg would restitute the factors after fertilization. However, how infected eggs rescue CI and how hosts' eggs ensure the proliferation and transmission of Wolbachia are not well understood.<br><br>RESULTS: By RNA-seq analyses, we first compared the transcription profiles of Drosophila melanogaster adult ovaries with and without the wMel Wolbachia and identified 149 differentially expressed genes (DEGs), of which 116 genes were upregulated and 33 were downregulated by Wolbachia infection. To confirm the results obtained from RNA-seq and to screen genes potentially associated with reproduction, 15 DEGs were selected for quantitative RT-PCR (qRT-PCR). Thirteen genes showed the same changing trend as RNA-seq analyses. To test whether these genes are associated with CI, we also detected their expression levels in testes. Nine of them exhibited different changing trends in testes from those in ovaries. To investigate how these DEGs were regulated, sRNA sequencing was performed and identified seven microRNAs (miRNAs) that were all upregulated in fly ovaries by Wolbachia infection. Matching of miRNA and mRNA data showed that these seven miRNAs regulated 15 DEGs. Wolbachia-responsive genes in fly ovaries were involved in biological processes including metabolism, transportation, oxidation-reduction, immunity, and development.<br><br>CONCLUSIONS: Comparisons of mRNA and miRNA data from fly ovaries revealed 149 mRNAs and seven miRNAs that exhibit significant changes in expression due to Wolbachia infection. Notably, most of the DEGs showed variation in opposite directions in ovaries versus testes in the presence of Wolbachia, which generally supports the "titration-restitution" model for CI. Furthermore, genes related to metabolism were upregulated, which may benefit maximum proliferation and transmission of Wolbachia. This provides new insights into the molecular mechanisms of Wolbachia-induced CI and Wolbachia dependence on host ovaries.}, }
@article {pmid31335437, year = {2019}, author = {Barkati, S and Ndao, M and Libman, M}, title = {Cutaneous leishmaniasis in the 21st century: from the laboratory to the bedside.}, journal = {Current opinion in infectious diseases}, volume = {32}, number = {5}, pages = {419-425}, doi = {10.1097/QCO.0000000000000579}, pmid = {31335437}, issn = {1473-6527}, mesh = {Antiprotozoal Agents/therapeutic use ; Diagnostic Tests, Routine/methods ; Disease Management ; *Drug Resistance, Microbial ; Genotype ; Global Health ; Humans ; Leishmania/classification/*drug effects/genetics/*virology ; Leishmaniasis, Cutaneous/diagnosis/drug therapy/*epidemiology/parasitology ; Neglected Diseases/*epidemiology ; Prognosis ; RNA Viruses/*isolation &amp; purification ; }, abstract = {PURPOSE OF REVIEW: Despite modern advances in molecular diagnostic tools and a better understanding of its complex pathophysiology, cutaneous leishmaniasis, a neglected tropical disease, remains a major global health problem. Laboratory methods to inform prognosis and treatment are not widely available, the therapeutic options are limited and have significant adverse effects, and emergence of drug resistance is a further complication. New advances in the understanding of the role of Leishmania RNA virus (LRV) as a prognostic factor, speciation methods and antimicrobial resistance testing and their limitations will be discussed.<br><br>RECENT FINDINGS: LRV, an intracytoplasmic endosymbiont found mostly in Leishmania spp. associated with more severe disease, appears to play a role in modulating the host immune response and has been associated with treatment failure in some Viannia subgenus species. Proper speciation is an important guide to management. However, recent findings have demonstrated significant heterogeneity of results related to differences in genotyping methods.<br><br>SUMMARY: Recognition of the role of LRV in immune modulation and response to treatment along with more accessible tools for its detection to guide management at the bedside should allow a better individualized approach. Improving accessibility and standardization of speciation methods and antimicrobial susceptibility testing should be major goals to improve cutaneous leishmaniasis management in the 21st century.}, }
@article {pmid31334752, year = {2019}, author = {Rejili, M and Msaddak, A and Filali, I and Benabderrahim, MA and Mars, M and Marín, M}, title = {New chromosomal lineages within Microvirga and Bradyrhizobium genera nodulate Lupinus angustifolius growing on different Tunisian soils.}, journal = {FEMS microbiology ecology}, volume = {95}, number = {9}, pages = {}, doi = {10.1093/femsec/fiz118}, pmid = {31334752}, issn = {1574-6941}, mesh = {Bacterial Proteins/genetics/metabolism ; Bacterial Typing Techniques ; Bradyrhizobium/classification/*genetics/isolation &amp; purification/physiology ; Chromosomes, Bacterial/genetics ; DNA, Bacterial/genetics ; Lupinus/*microbiology ; Methylobacteriaceae/classification/*genetics/isolation &amp; purification/physiology ; Multilocus Sequence Typing ; Phylogeny ; *Plant Root Nodulation ; Root Nodules, Plant/microbiology ; Soil Microbiology ; Symbiosis ; Tunisia ; }, abstract = {Thirty-one rhizobial isolates nodulating native Lupinus angustifolius (blue lupine) plants growing in Northern Tunisian soils were isolated and analysed using different chromosomal and symbiotic gene markers. Phylogenetic analyses based on recA partial sequences grouped them into at least five groups: four of them within the genus Bradyrhizobium (26 isolates) and one into the genus Microvirga (5 isolates). Representative strains were analysed by multilocus sequence analysis of three housekeeping genes rrs-recA-glnII and rrs-gyrB-dnaK for Bradyrhizobium and Microvirga isolates, respectively. Based on this analysis, eight isolates clustered with the previously described strains Bradyrhizobium lupini USDA3051 and Bradyrhizobium canariense BTA-1. However, five of the isolates clustered separately and may constitute a new species within the Bradyrhizobium genus. The remaining five isolates were closely related to the strain Microvirga sp. LmiM8 and may constitute a new Microvirga species. The analysis of the nodC gene showed that all Bradyrhizobium strains nodulating blue lupine belong to the symbiovar genistearum, whereas the Microvirga isolates are associated with the symbiovar mediterranense. The results of this study support that the L. angustifolius root nodule symbionts isolated in Northern Tunisia belong mostly to the B. canariense/B. lupini lineages. However, new clades of Bradyrhizobium and Microvirga have been identified as L. angustifolius endosymbionts.}, }
@article {pmid31329312, year = {2019}, author = {Chan, WY and Peplow, LM and Menéndez, P and Hoffmann, AA and van Oppen, MJH}, title = {The roles of age, parentage and environment on bacterial and algal endosymbiont communities in Acropora corals.}, journal = {Molecular ecology}, volume = {28}, number = {16}, pages = {3830-3843}, doi = {10.1111/mec.15187}, pmid = {31329312}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*microbiology ; Australia ; Bacteria/*classification ; DNA Barcoding, Taxonomic ; Dinoflagellida/*classification ; Hybridization, Genetic ; Life Cycle Stages ; *Microbiota ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; *Symbiosis ; }, abstract = {The bacterial and microalgal endosymbiont (Symbiodiniaceae spp.) communities associated with corals have important roles in their health and resilience, yet little is known about the factors driving their succession during early coral life stages. Using 16S rRNA gene and ITS2 metabarcoding, we compared these communities in four Acropora coral species and their hybrids obtained from two laboratory crosses (Acropora tenuis × Acropora loripes and Acropora sarmentosa × Acropora florida) across the parental, recruit (7 months old) and juvenile (2 years old) life stages. We tested whether microbiomes differed between (a) life stages, (b) hybrids and purebreds, and (c) treatment conditions (ambient/elevated temperature and pCO2). Microbial communities of early life stage corals were highly diverse, lacked host specificity and were primarily determined by treatment conditions. Over time, a winnowing process occurred, and distinct microbial communities developed between the two species pair crosses by 2 years of age, irrespective of hybrid or purebred status. These findings suggest that the microbial communities of corals have a period of flexibility prior to adulthood, which can be valuable to future research aimed at the manipulation of coral microbial communities.}, }
@article {pmid31328784, year = {2019}, author = {Muñoz-Gómez, SA and Durnin, K and Eme, L and Paight, C and Lane, CE and Saffo, MB and Slamovits, CH}, title = {Nephromyces Represents a Diverse and Novel Lineage of the Apicomplexa That Has Retained Apicoplasts.}, journal = {Genome biology and evolution}, volume = {11}, number = {10}, pages = {2727-2740}, pmid = {31328784}, issn = {1759-6653}, support = {R03 AI124092/AI/NIAID NIH HHS/United States ; }, mesh = {Apicomplexa/classification/*genetics ; Apicoplasts/*genetics ; Cell Nucleus/genetics ; *Genome ; Metabolic Networks and Pathways/genetics ; Phylogeny ; }, abstract = {A most interesting exception within the parasitic Apicomplexa is Nephromyces, an extracellular, probably mutualistic, endosymbiont found living inside molgulid ascidian tunicates (i.e., sea squirts). Even though Nephromyces is now known to be an apicomplexan, many other questions about its nature remain unanswered. To gain further insights into the biology and evolutionary history of this unusual apicomplexan, we aimed to 1) find the precise phylogenetic position of Nephromyces within the Apicomplexa, 2) search for the apicoplast genome of Nephromyces, and 3) infer the major metabolic pathways in the apicoplast of Nephromyces. To do this, we sequenced a metagenome and a metatranscriptome from the molgulid renal sac, the specialized habitat where Nephromyces thrives. Our phylogenetic analyses of conserved nucleus-encoded genes robustly suggest that Nephromyces is a novel lineage sister to the Hematozoa, which comprises both the Haemosporidia (e.g., Plasmodium) and the Piroplasmida (e.g., Babesia and Theileria). Furthermore, a survey of the renal sac metagenome revealed 13 small contigs that closely resemble the genomes of the nonphotosynthetic reduced plastids, or apicoplasts, of other apicomplexans. We show that these apicoplast genomes correspond to a diverse set of most closely related but genetically divergent Nephromyces lineages that co-inhabit a single tunicate host. In addition, the apicoplast of Nephromyces appears to have retained all biosynthetic pathways inferred to have been ancestral to parasitic apicomplexans. Our results shed light on the evolutionary history of the only probably mutualistic apicomplexan known, Nephromyces, and provide context for a better understanding of its life style and intricate symbiosis.}, }
@article {pmid31328166, year = {2019}, author = {Van Steenkiste, NWL and Stephenson, I and Herranz, M and Husnik, F and Keeling, PJ and Leander, BS}, title = {A new case of kleptoplasty in animals: Marine flatworms steal functional plastids from diatoms.}, journal = {Science advances}, volume = {5}, number = {7}, pages = {eaaw4337}, pmid = {31328166}, issn = {2375-2548}, mesh = {Animals ; *Aquatic Organisms ; *Diatoms ; Gene Expression Profiling ; Photosynthesis ; Phylogeny ; Plastids/*genetics/ultrastructure ; Platyhelminths/classification/*physiology ; Transcriptome ; }, abstract = {To date, sea slugs have been considered the only animals known to sequester functional algal plastids into their own cells, via a process called "kleptoplasty." We report here, however, that endosymbionts in the marine flatworms Baicalellia solaris and Pogaina paranygulgus are isolated plastids stolen from diatoms. Ultrastructural data show that kleptoplasts are located within flatworm cells, while algal nuclei and other organelles are absent. Transcriptomic analysis and rbcL amplicons confirm the absence of algal nuclear mRNA and reveal that the plastids originate from different species of diatoms. Laboratory experiments demonstrated photosynthetic activity and short-term retention of kleptoplasts in starved worms. This lineage of flatworms represents the first known case of functional kleptoplasty involving diatoms and only the second known case of kleptoplasty across the entire tree of animals.}, }
@article {pmid31323841, year = {2019}, author = {Bakowski, MA and McNamara, CW}, title = {Advances in Antiwolbachial Drug Discovery for Treatment of Parasitic Filarial Worm Infections.}, journal = {Tropical medicine and infectious disease}, volume = {4}, number = {3}, pages = {}, pmid = {31323841}, issn = {2414-6366}, abstract = {The intracellular bacteria now known as Wolbachia were first described in filarial worms in the 1970s, but the idea of Wolbachia being used as a macrofilaricidal target did not gain wide attention until the early 2000s, with research in filariae suggesting the requirement of worms for the endosymbiont. This new-found interest prompted the eventual organization of the Anti-Wolbachia Consortium (A-WOL) at the Liverpool School of Tropical Medicine, who, among others have been active in the field of antiwolbachial drug discovery to treat filarial infections. Clinical proof of concept studies using doxycycline demonstrated the utility of the antiwolbachial therapy, but efficacious treatments were of long duration and not safe for all infected. With the advance of robotics, automation, and high-speed computing, the search for superior antiwolbachials shifted away from smaller studies with a select number of antibiotics to high-throughput screening approaches, centered largely around cell-based phenotypic screens due to the rather limited knowledge about, and tools available to manipulate, this bacterium. A concomitant effort was put towards developing validation approaches and in vivo models supporting drug discovery efforts. In this review, we summarize the strategies behind and outcomes of recent large phenotypic screens published within the last 5 years, hit compound validation approaches and promising candidates with profiles superior to doxycycline, including ones positioned to advance into clinical trials for treatment of filarial worm infections.}, }
@article {pmid31312027, year = {2019}, author = {Macher, JN and Speksnijder, A and Choo, LQ and van der Hoorn, B and Renema, W}, title = {Uncovering bacterial and functional diversity in macroinvertebrate mitochondrial-metagenomic datasets by differential centrifugation.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {10257}, pmid = {31312027}, issn = {2045-2322}, mesh = {Animals ; Bacteria/classification/genetics ; *Biodiversity ; Centrifugation/methods ; Databases, Genetic ; Invertebrates/genetics/*microbiology ; *Metagenome ; Metagenomics/methods ; Mitochondria/genetics ; }, abstract = {PCR-free techniques such as meta-mitogenomics (MMG) can recover taxonomic composition of macroinvertebrate communities, but suffer from low efficiency, as >90% of sequencing data is mostly uninformative due to the great abundance of nuclear DNA that cannot be identified with current reference databases. Current MMG studies do not routinely check data for information on macroinvertebrate-associated bacteria and gene functions. However, this could greatly increase the efficiency of MMG studies by revealing yet overlooked diversity within ecosystems and making currently unused data available for ecological studies. By analysing six 'mock' communities, each containing three macroinvertebrate taxa, we tested whether this additional data on bacterial taxa and functional potential of communities can be extracted from MMG datasets. Further, we tested whether differential centrifugation, which is known to greatly increase efficiency of macroinvertebrate MMG studies by enriching for mitochondria, impacts on the inferred bacterial community composition. Our results show that macroinvertebrate MMG datasets contain a high number of mostly endosymbiont bacterial taxa and associated gene functions. Centrifugation reduced both the absolute and relative abundance of highly abundant Gammaproteobacteria, thereby facilitating detection of rare taxa and functions. When analysing both taxa and gene functions, the number of features obtained from the MMG dataset increased 31-fold ('enriched') respectively 234-fold ('not enriched'). We conclude that analysing MMG datasets for bacteria and gene functions greatly increases the amount of information available and facilitates the use of shotgun metagenomic techniques for future studies on biodiversity.}, }
@article {pmid31311477, year = {2019}, author = {Boscaro, V and Husnik, F and Vannini, C and Keeling, PJ}, title = {Symbionts of the ciliate Euplotes: diversity, patterns and potential as models for bacteria-eukaryote endosymbioses.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1907}, pages = {20190693}, pmid = {31311477}, issn = {1471-2954}, mesh = {Burkholderiaceae/classification/genetics/*physiology ; Euplotes/*microbiology ; Microbiota ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; *Symbiosis ; }, abstract = {Endosymbioses between bacteria and eukaryotes are enormously important in ecology and evolution, and as such are intensely studied. Despite this, the range of investigated hosts is narrow in the context of the whole eukaryotic tree of life: most of the information pertains to animal hosts, while most of the diversity is found in unicellular protists. A prominent case study is the ciliate Euplotes, which has repeatedly taken up the bacterium Polynucleobacter from the environment, triggering its transformation into obligate endosymbiont. This multiple origin makes the relationship an excellent model to understand recent symbioses, but Euplotes may host bacteria other than Polynucleobacter, and a more detailed knowledge of these additional interactions is needed in order to correctly interpret the system. Here, we present the first systematic survey of Euplotes endosymbionts, adopting a classical as well as a metagenomic approach, and review the state of knowledge. The emerging picture is indeed quite complex, with some Euplotes harbouring rich, stable prokaryotic communities not unlike those of multicellular animals. We provide insights into the distribution, evolution and diversity of these symbionts (including the establishment of six novel bacterial taxa), and outline differences and similarities with the most well-understood group of eukaryotic hosts: insects.}, }
@article {pmid31306759, year = {2019}, author = {Chen, H and Wang, M and Zhang, H and Wang, H and Lv, Z and Zhou, L and Zhong, Z and Lian, C and Cao, L and Li, C}, title = {An LRR-domain containing protein identified in Bathymodiolus platifrons serves as intracellular recognition receptor for the endosymbiotic methane-oxidation bacteria.}, journal = {Fish &amp; shellfish immunology}, volume = {93}, number = {}, pages = {354-360}, doi = {10.1016/j.fsi.2019.07.032}, pmid = {31306759}, issn = {1095-9947}, mesh = {Amino Acid Sequence ; Animals ; Gene Expression Profiling ; Gene Expression Regulation/*immunology ; Immunity, Innate/*genetics ; Mytilidae/*genetics/*immunology ; Phylogeny ; Receptors, Pattern Recognition/chemistry/*genetics/*immunology ; Sequence Alignment ; }, abstract = {As domain species in seep and vent ecosystem, Bathymodioline mussels has been regarded as a model organism in investigating deep sea chemosymbiosis. However, mechanisms underlying their symbiosis with chemosynthetic bacteria, especially how the host recognizes symbionts, have remained largely unsolved. In the present study, a modified pull-down assay was conducted using enriched symbiotic methane-oxidation bacteria as bait and gill proteins of Bathymodiolus platifrons as a target to isolate pattern recognition receptors involved in the immune recognition of symbionts. As a result, a total of 47 proteins including BpLRR-1 were identified from the pull-down assay. It was found that complete cDNA sequence of BpLRR-1 contained an open reading frame of 1479 bp and could encode a protein of 492 amino acid residues with no signal peptide or transmembrane region but eight LRR motif and two EFh motif. The binding patterns of BpLRR-1 against microbial associated molecular patterns were subsequently investigated by surface plasmon resonance analysis and LPS pull-down assay. Consequently, BpLRR-1 was found with high binding affinity with LPS and suggested as a key molecule in recognizing symbionts. Besides, transcripts of BpLRR-1 were found decreased significantly during symbiont depletion assay yet increased rigorously during symbionts or nonsymbiotic Vibrio alginolyticus challenge, further demonstrating its participation in the chemosynthetic symbiosis. Collectively, these results suggest that BpLRR-1 could serve as an intracellular recognition receptor for the endosymbionts, providing new hints for understanding the immune recognition in symbiosis of B. platifrons.}, }
@article {pmid31303231, year = {2019}, author = {Koh, FX and Nurhidayah, MN and Tan, PE and Kho, KL and Tay, ST}, title = {Francisella spp. detected in Dermacentor ticks in Malaysian forest reserve areas.}, journal = {Veterinary parasitology, regional studies and reports}, volume = {17}, number = {}, pages = {100315}, doi = {10.1016/j.vprsr.2019.100315}, pmid = {31303231}, issn = {2405-9390}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Cattle ; Cattle Diseases/parasitology ; DNA/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry ; Dermacentor/*microbiology ; Female ; Forests ; Francisella/classification/genetics/*isolation &amp; purification ; Gram-Negative Bacterial Infections/microbiology/*transmission ; Malaysia ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus/microbiology ; Sheep ; Sheep Diseases/parasitology ; Tick Infestations/parasitology/veterinary ; Tick-Borne Diseases/microbiology/*transmission ; Tularemia/microbiology/transmission ; }, abstract = {Limited information is available on tropical ticks and tick-borne bacteria affecting the health of humans and animals in the Southeast Asia region. Francisella tularensis is a tick-borne bacterium which causes a potentially life-threatening disease known as tularemia. This study was conducted to determine the occurrence of Francisella spp. in questing ticks collected from Malaysian forest reserve areas. A total of 106 ticks (mainly Dermacentor and Haemaphysalis spp.) were examined for Francisella DNA using a Polymerase chain reaction (PCR) assay targeting the bacterial 16S rDNA. Francisella DNA was detected from 12 Dermacentor ticks. Sequence analysis of the amplified 16S rDNA sequences (1035 bp) show >99% identity with that of Francisella endosymbiont reported in a tick from Thailand. A dendrogram constructed based on the bacterial 16S rDNA shows that the Francisella spp. were distantly related to the pathogenic strains of F. tularensis. Three Francisella-positive ticks were identified as Dermacentor atrosignatus, based on sequence analysis of the tick mitochondrial 16S rRNA gene. Further screening of cattle and sheep ticks (Haemaphysalis bispinosa and Rhipicephalus microplus) and animal samples (cattle, sheep, and goats) did not yield any positive findings. Our findings provide the first molecular data on the occurrence of a Francisella strain with unknown pathogenicity in Dermacentor questing ticks in Malaysia.}, }
@article {pmid31300838, year = {2020}, author = {White, JA and Styer, A and Rosenwald, LC and Curry, MM and Welch, KD and Athey, KJ and Chapman, EG}, title = {Endosymbiotic Bacteria Are Prevalent and Diverse in Agricultural Spiders.}, journal = {Microbial ecology}, volume = {79}, number = {2}, pages = {472-481}, pmid = {31300838}, issn = {1432-184X}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Bacteriological Techniques/*methods ; Entomology/*methods ; Food Deprivation ; High-Throughput Nucleotide Sequencing ; Kentucky ; *Microbiota/genetics ; Polymerase Chain Reaction ; Spiders/*microbiology ; Symbiosis/*physiology ; }, abstract = {Maternally inherited bacterial endosymbionts are common in arthropods, but their distribution and prevalence are poorly characterized in many host taxa. Initial surveys have suggested that vertically transmitted symbionts may be particularly common in spiders (Araneae). Here, we used diagnostic PCR and high-throughput sequencing to evaluate symbiont infection in 267 individual spiders representing 14 species (3 families) of agricultural spiders. We found 27 operational taxonomic units (OTUs) that are likely endosymbiotic, including multiple strains of Wolbachia, Rickettsia, and Cardinium, which are all vertically transmitted and frequently associated with reproductive manipulation of arthropod hosts. Additional strains included Rickettsiella, Spiroplasma, Rhabdochlamydia, and a novel Rickettsiales, all of which could range from pathogenic to mutualistic in their effects upon their hosts. Seventy percent of spider species had individuals that tested positive for one or more endosymbiotic OTUs, and specimens frequently contained multiple symbiotic strain types. The most symbiont-rich species, Idionella rugosa, had eight endosymbiotic OTUs, with as many as five present in the same specimen. Individual specimens within infected spider species had a variety of symbiotypes, differing from one another in the presence or absence of symbiotic strains. Our sample included both starved and unstarved specimens, and dominant bacterial OTUs were consistent per host species, regardless of feeding status. We conclude that spiders contain a remarkably diverse symbiotic microbiota. Spiders would be an informative group for investigating endosymbiont population dynamics in time and space, and unstarved specimens collected for other purposes (e.g., food web studies) could be used, with caution, for such investigations.}, }
@article {pmid31288476, year = {2019}, author = {Oborník, M}, title = {Endosymbiotic Evolution of Algae, Secondary Heterotrophy and Parasitism.}, journal = {Biomolecules}, volume = {9}, number = {7}, pages = {}, pmid = {31288476}, issn = {2218-273X}, mesh = {*Chlorophyta/metabolism/microbiology ; Electron Transport ; Heterotrophic Processes ; *Symbiosis ; }, abstract = {Photosynthesis is a biochemical process essential for life, serving as the ultimate source of chemical energy for phototrophic and heterotrophic life forms. Since the machinery of the photosynthetic electron transport chain is quite complex and is unlikely to have evolved multiple independent times, it is believed that this machinery has been transferred to diverse eukaryotic organisms by endosymbiotic events involving a eukaryotic host and a phototrophic endosymbiont. Thus, photoautotrophy, as a benefit, is transmitted through the evolution of plastids. However, many eukaryotes became secondarily heterotrophic, reverting to hetero-osmotrophy, phagotrophy, or parasitism. Here, I briefly review the constructive evolution of plastid endosymbioses and the consequential switch to reductive evolution involving losses of photosynthesis and plastids and the evolution of parasitism from a photosynthetic ancestor.}, }
@article {pmid31283888, year = {2019}, author = {Harish, ER and ManiChellappan,  and MakeshKumar, T and Mathew, D and Ranjith, MT and Girija, D}, title = {Next-generation sequencing reveals endosymbiont variability in cassava whitefly, Bemisia tabaci, across the agro-ecological zones of Kerala, India.}, journal = {Genome}, volume = {62}, number = {9}, pages = {571-584}, doi = {10.1139/gen-2018-0050}, pmid = {31283888}, issn = {1480-3321}, mesh = {Animals ; Bacteria/*classification/isolation &amp; purification ; DNA, Bacterial ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing ; India ; Manihot/*parasitology ; Molecular Typing ; *Symbiosis ; }, abstract = {Silverleaf whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most notorious invasive insect pests, infesting more than 900 species of plants and spreading more than 200 viral diseases. This polyphagous agricultural pest harbours diverse bacterial communities in its gut, which perform multiple functions in whiteflies, including nutrient provisioning, amino acid biosynthesis, and virus transmission. The present exploratory study compares the bacterial communities associated with silverleaf whitefly infesting cassava, also known as cassava whitefly, collected from two different zones (zone P: plains; zone H: high ranges), from Kerala, India, using next-generation sequencing of 16S rDNA. The data sets for these two regions consisted of 1 321 906 and 690 661 high-quality paired-end sequences with mean length of 150 bp. Highly diverse bacterial communities were present in the sample, containing approximately 3513 operational taxonomic units (OTUs). Sequence analysis showed a marked difference in the relative abundance of bacteria in the populations. A total of 16 bacterial phyla, 27 classes, 56 orders, 91 families, 236 genera, and 409 species were identified from the P population, against 16, 31, 60, 88, 225, and 355, respectively, in the H population. Arsenophonus sp. (Enterobacteriaceae), which is important for virus transmission by whiteflies, was relatively abundant in the P population, whereas in the H population Bacillus sp. was the most dominant group. The association of whitefly biotypes and secondary symbionts suggests a possible contribution of these bacteria to host characteristics such as virus transmission, host range, insecticide resistance, and speciation.}, }
@article {pmid31283172, year = {2019}, author = {Niehs, SP and Dose, B and Scherlach, K and Pidot, SJ and Stinear, TP and Hertweck, C}, title = {Genome Mining Reveals Endopyrroles from a Nonribosomal Peptide Assembly Line Triggered in Fungal-Bacterial Symbiosis.}, journal = {ACS chemical biology}, volume = {14}, number = {8}, pages = {1811-1818}, doi = {10.1021/acschembio.9b00406}, pmid = {31283172}, issn = {1554-8937}, mesh = {Burkholderiaceae/genetics/metabolism ; Depsipeptides/*biosynthesis ; Genome, Bacterial/physiology ; Genomics/methods ; Multigene Family/physiology ; Proof of Concept Study ; Pyrroles/*metabolism ; Rhizopus/metabolism ; Symbiosis/*physiology ; }, abstract = {The bacterial endosymbiont (Burkholderia rhizoxinica) of the rice seedling blight fungus (Rhizopus microsporus) harbors a large number of cryptic biosynthesis gene clusters. Genome mining and sequence similarity networks based on an encoded nonribosomal peptide assembly line and the associated pyrrole-forming enzymes in the symbiont indicated that the encoded metabolites are unique among a large number of tentative pyrrole natural products in diverse and unrelated bacterial phyla. By performing comparative metabolic profiling using a mutant generated with an improved pheS Burkholderia counterselection marker, we found that the symbionts' biosynthetic pathway is mainly activated under salt stress and exclusively in symbiosis with the fungal host. The cryptic metabolites were fully characterized as novel pyrrole-substituted depsipeptides (endopyrroles). A broader survey showed that endopyrrole production is a hallmark of geographically distant endofungal bacteria, which produce the peptides solely under symbiotic conditions.}, }
@article {pmid31269657, year = {2019}, author = {van Oers, MM and Eilenberg, J}, title = {Mechanisms Underlying the Transmission of Insect Pathogens.}, journal = {Insects}, volume = {10}, number = {7}, pages = {}, pmid = {31269657}, issn = {2075-4450}, abstract = {In this special issue the focus is on the factors and (molecular) mechanisms that determine the transmission efficiency of a variety of insect pathogens in a number of insect hosts. In this editorial, we summarize the main findings of the twelve papers in this special issue and conclude that much more needs to be learned for an in-depth understanding of pathogen transmission in field and cultured insect populations. Analyses of mutual interactions between pathogens or between endosymbionts and pathogens, aspects rather under-represented in the scientific literature, are described in a number of contributions to this special issue.}, }
@article {pmid31265751, year = {2020}, author = {Yang, K and Xie, K and Zhu, YX and Huo, SM and Hoffmann, A and Hong, XY}, title = {Wolbachia dominate Spiroplasma in the co-infected spider mite Tetranychus truncatus.}, journal = {Insect molecular biology}, volume = {29}, number = {1}, pages = {19-37}, doi = {10.1111/imb.12607}, pmid = {31265751}, issn = {1365-2583}, mesh = {Animals ; Coinfection/microbiology ; Female ; Fertility ; Gene Expression Profiling ; Male ; Spiroplasma/*physiology ; Symbiosis ; Tetranychidae/genetics/metabolism/*microbiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia and Spiroplasma are both maternally inherited endosymbionts in arthropods, and they can co-infect the same species. However, how they interact with each other in the same host is not clear. Here we investigate a co-infected Tetranychus truncatus spider mite strain that shares the same genetic background with singly infected and uninfected strains to detect the impacts of the two symbionts on their host. We found that Wolbachia-infected and Spiroplasma-infected mites can suffer significant fitness costs involving decreased fecundity, although with no effect on lifespan or development. Wolbachia induced incomplete cytoplasmic incompatibility in T. truncatus both in singly infected and doubly infected strains, resulting in female killing. In both females and males of the co-infected spider mite strain, Wolbachia density was higher than Spiroplasma density. Transcriptome analysis of female adults showed that the most differentially expressed genes were found between the co-infected strain and both the singly infected Spiroplasma strain and uninfected strain. The Wolbachia strain had the fewest differentially expressed genes compared with the co-infected strain, consistent with the higher density of Wolbachia in the co-infected strain. Wolbachia, therefore, appears to have a competitive advantage in host mites over Spiroplasma and is likely maintained in populations by cytoplasmic incompatibility despite having deleterious fitness effects.}, }
@article {pmid31263246, year = {2019}, author = {van Oppen, MJH and Blackall, LL}, title = {Coral microbiome dynamics, functions and design in a changing world.}, journal = {Nature reviews. Microbiology}, volume = {17}, number = {9}, pages = {557-567}, doi = {10.1038/s41579-019-0223-4}, pmid = {31263246}, issn = {1740-1534}, mesh = {Adaptation, Physiological ; Animals ; Anthozoa/*microbiology ; Bacteria/classification/*growth &amp; development/isolation &amp; purification ; Global Warming ; *Host Microbial Interactions ; *Microbiota ; }, abstract = {Corals associate not only with dinoflagellates, which are their algal endosymbionts and which have been extensively studied over the past four decades, but also with a variety of other microorganisms. The coral microbiome includes dinoflagellates, viruses, fungi, archaea and bacteria, with knowledge of the latter growing rapidly. This Review focuses on the bacterial members of the coral microbiome and draws parallels with better-studied microbiomes in other biological systems. We synthesize current understanding of spatial, temporal and host-specific patterns in coral-associated bacterial communities, the drivers shaping these patterns, and the role of the microbiome in acclimatization and adaptation of the host to climate warming. We discuss how this knowledge can be harnessed to assist the future persistence of coral reefs and provide novel perspectives for the development of microbiome engineering and its implications for coral reef conservation and restoration.}, }
@article {pmid31251761, year = {2019}, author = {Carballo-Bolaños, R and Denis, V and Huang, YY and Keshavmurthy, S and Chen, CA}, title = {Temporal variation and photochemical efficiency of species in Symbiodinaceae associated with coral Leptoria phrygia (Scleractinia; Merulinidae) exposed to contrasting temperature regimes.}, journal = {PloS one}, volume = {14}, number = {6}, pages = {e0218801}, pmid = {31251761}, issn = {1932-6203}, mesh = {Acclimatization ; Alveolata/chemistry/*classification/isolation &amp; purification ; Animals ; Anthozoa/*parasitology ; Chlorophyll A/*metabolism ; DNA, Protozoan/genetics ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; Taiwan ; Temperature ; }, abstract = {The Symbiodinaceae are paradoxical in that they play a fundamental role in the success of scleractinian corals, but also in their dismissal when under stress. In the past decades, the discovery of the endosymbiont's genetic and functional diversity has led people to hope that some coral species can survive bleaching events by associating with a stress-resistant symbiont that can become dominant when seawater temperatures increase. The variety of individual responses encouraged us to scrutinize each species individually to gauge its resilience to future changes. Here, we analyse the temporal variation in the Symbiodinaceae community associated with Leptoria phrygia, a common scleractinian coral from the Indo-Pacific. Coral colonies were sampled from two distant reef sites located in southern Taiwan that differ in temperature regimes, exemplifying a 'variable site' (VS) and a 'steady site' (SS). We investigated changes in the relative abundance of the dominant symbiont and its physiology every 3-4 months from 2016-2017. At VS, 11 of the 12 colonies were dominated by the stress-resistant Durusdinium spp. (>90% dominance) and only one colony exhibited co-dominance between Durusdinium spp. and Cladocopium spp. Every colony displayed high photochemical efficiency across all sampling periods, while showing temporal differences in symbiont density and chlorophyll a concentration. At SS, seven colonies out of 13 were dominated by Cladocopium spp., five presented co-dominance between Durusdinium spp./Cladocopium spp. and only one was dominated by Durusdinium spp. Colonies showed temporal differences in photochemical efficiency and chlorophyll a concentration during the study period. Our results suggest that VS colonies responded physiologically better to high temperature variability by associating with Durusdinium spp., while in SS there is still inter-colonial variability, a feature that might be advantageous for coping with different environmental changes.}, }
@article {pmid31247412, year = {2019}, author = {Sicard, M and Bonneau, M and Weill, M}, title = {Wolbachia prevalence, diversity, and ability to induce cytoplasmic incompatibility in mosquitoes.}, journal = {Current opinion in insect science}, volume = {34}, number = {}, pages = {12-20}, doi = {10.1016/j.cois.2019.02.005}, pmid = {31247412}, issn = {2214-5753}, mesh = {Animals ; Culicidae/*microbiology ; Female ; Genes, Bacterial ; Male ; *Mosquito Control ; *Wolbachia ; }, abstract = {To protect humans and domestic animals from mosquito borne diseases, alternative methods to chemical insecticides have to be found. Pilot studies using the vertically transmitted bacterial endosymbiont Wolbachia were already launched in different parts of the world. Wolbachia can be used either in Incompatible Insect Technique (IIT), to decrease mosquito population, or to decrease the ability of mosquitoes to transmit pathogens. Not all mosquito species are naturally infected with Wolbachia: while in Culex pipiens and Aedes albopictus almost all individuals harbor Wolbachia, putative infections have to be further investigated in Anopheles species and in Aedes aegypti. All Wolbachia-based control methods rely on the ability of Wolbachia to induce cytoplasmic incompatibility (CI) resulting in embryonic death in incompatible crossings. Knowledge on CI diversity in mosquito is required to find the better Wolbachia-mosquito associations to optimize the success of both 'sterile insect' and 'pathogen blocking' Wolbachia-based methods.}, }
@article {pmid31242223, year = {2019}, author = {Mobasseri, M and Hutchinson, MC and Afshar, FJ and Pedram, M}, title = {New evidence of nematode-endosymbiont bacteria coevolution based on one new and one known dagger nematode species of Xiphinema americanum-group (Nematoda, Longidoridae).}, journal = {PloS one}, volume = {14}, number = {6}, pages = {e0217506}, pmid = {31242223}, issn = {1932-6203}, mesh = {Animals ; *Bacteria/classification/genetics ; *Nematoda/genetics/microbiology ; *Phylogeny ; Symbiosis/*physiology ; }, abstract = {Three populations of Xiphinema primum n. sp. and two populations of X. pachtaicum were recovered from natural forests and cultural regions of northern Iran. Both species belong to the X. americanum-group and were characterized by their morphological, morphometric and molecular data. The new species, which was recovered in three locations, belongs to the X. brevicolle-complex and is characterized by 2124-2981 μm long females with a widely rounded lip region separated from the rest of the body by a depression, 103-125 μm long odontostyle, two equally developed genital branches with endosymbiont bacteria inside the ovary, which are visible under light microscope (LM), vulva located at 51.8-58.0%, the tail is 26-37 μm long with a bluntly rounded end and four juvenile developmental stages. It was morphologically compared with nine similar species viz. X. brevicolle, X. diffusum, X. incognitum, X. himalayense, X. luci, X. parabrevicolle, X. paramonovi, X. parataylori and X. taylori. The second species, X. pachtaicum, was recovered in two geographically distant points close to city of Amol. Molecular phylogenetic studies of the new species were performed using partial sequences of the D2-D3 expansion segments of the large subunit ribosomal RNA gene (LSU rDNA D2-D3), the internal-transcribed spacer rDNA (ITS = ITS1+5.8S+ITS2), and the mitochondrial cytochrome c oxidase I gene (COI mtDNA) regions. The Iranian population of X. pachtaicum was also phylogenetically studied based upon its LSU rDNA D2-D3 sequences. Both species were also inspected for their putative endosymbiont bacteria. Candidatus Xiphinematobacter sp. was detected from two examined populations of the new species, whereas the second endosymbiont bacterium, detected from three examined isolates of X. pachtaicum, was related to the plant and fungal endosymbionts of the family Burkholderiaceae. The phylogenetic analyses of the two endosymbiont bacteria were performed using partial sequences of 16S rDNA. In cophylogenetic analyses, significant levels of cophylogenetic signal were observed using both LSU rDNA D2-D3 and COI mtDNA markers of the host nematodes and 16S rDNA marker of the endosymbiont bacteria.}, }
@article {pmid31234774, year = {2019}, author = {Thapa, S and Zhang, Y and Allen, MS}, title = {Bacterial microbiomes of Ixodes scapularis ticks collected from Massachusetts and Texas, USA.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {138}, pmid = {31234774}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; Dogs/microbiology ; Female ; High-Throughput Nucleotide Sequencing/*methods ; Ixodes/*microbiology ; Male ; Massachusetts ; Microbiota ; Phylogeny ; Phylogeography ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA/methods ; Sex Characteristics ; Texas ; }, abstract = {BACKGROUND: The blacklegged tick, Ixodes scapularis, is the primary vector of the Lyme disease spirochete Borrelia burgdorferi in North America. Though the tick is found across the eastern United States, Lyme disease is endemic to the northeast and upper midwest and rare or absent in the southern portion of the vector's range. In an effort to better understand the tick microbiome from diverse geographic and climatic regions, we analysed the bacterial community of 115 I. scapularis adults collected from vegetation in Texas and Massachusetts, representing extreme ends of the vector's range, by massively parallel sequencing of the 16S V4 rRNA gene. In addition, 7 female I. scapularis collected from dogs in Texas were included in the study.<br><br>RESULTS: Male I. scapularis ticks had a more diverse bacterial microbiome in comparison to the female ticks. Rickettsia spp. dominated the microbiomes of field-collected female I. scapularis from both regions, as well as half of the males from Texas. In addition, the male and female ticks captured from Massachusetts contained high proportions of the pathogens Anaplasma and Borrelia, as well as the arthropod endosymbiont Wolbachia. None of these were found in libraries generated from ticks collected in Texas. Pseudomonas, Acinetobacter and Mycobacterium were significantly differently abundant (p&#x2009;<&#xa0;0.05) between the male ticks from Massachusetts and Texas. Anaplasma and Borrelia were found in 15 and 63% of the 62 Massachusetts ticks, respectively, with a co-infection rate of 11%. Female ticks collected from Texas dogs were particularly diverse, and contained several genera including Rickettsia, Pseudomonas, Bradyrhizobium, Sediminibacterium, and Ralstonia.<br><br>CONCLUSIONS: Our results indicate that the bacterial microbiomes of I. scapularis ticks vary by sex and geography, with significantly more diversity in male microbiomes compared to females. We found that sex plays a larger role than geography in shaping the composition/diversity of the I. scapularis microbiome, but that geography affects what additional taxa are represented (beyond Rickettsia) and whether pathogens are found. Furthermore, recent feeding may have a role in shaping the tick microbiome, as evident from a more complex bacterial community in female ticks from dogs compared to the wild-caught questing females. These findings may provide further insight into the differences in the ability of the ticks to acquire, maintain and transmit pathogens. Future studies on possible causes and consequences of these differences will shed additional light on tick microbiome biology and vector competence.}, }
@article {pmid31232527, year = {2020}, author = {Headley, SA and Viana, NE and Michelazzo, MMZ and Xavier, AAC and Costa, CJS and de Pinho, FHO and Dos Santos, MD}, title = {Neorickettsia helminthoeca associated lymphoid, enteric, and pulmonary lesions in dogs from Southern Brazil: An immunohistochemical study.}, journal = {Transboundary and emerging diseases}, volume = {67 Suppl 2}, number = {}, pages = {49-59}, doi = {10.1111/tbed.13194}, pmid = {31232527}, issn = {1865-1682}, mesh = {Anaplasmataceae Infections/*veterinary ; Animals ; Antibodies, Bacterial/blood ; Antibodies, Viral/blood ; Antigens, Bacterial/immunology ; Brazil/epidemiology ; Cross Reactions ; Distemper Virus, Canine/immunology ; Dog Diseases/epidemiology/immunology/*microbiology ; Dogs ; Female ; Gastroenteritis/epidemiology/immunology/microbiology/*veterinary ; Immunohistochemistry ; Lung Diseases/epidemiology/immunology/microbiology/*veterinary ; Lymphatic Diseases/epidemiology/immunology/microbiology/*veterinary ; Male ; Neorickettsia/immunology/*isolation &amp; purification ; Parvovirus, Canine/immunology ; Symbiosis ; }, abstract = {Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish-eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH-induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus-2 (CPV-2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH-induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV-2.}, }
@article {pmid31232523, year = {2020}, author = {Zhao, DX and Zhang, ZC and Niu, HT and Guo, HF}, title = {Selective and stable elimination of endosymbionts from multiple-infected whitefly Bemisia tabaci by feeding on a cotton plant cultured in antibiotic solutions.}, journal = {Insect science}, volume = {27}, number = {5}, pages = {964-974}, doi = {10.1111/1744-7917.12703}, pmid = {31232523}, issn = {1744-7917}, mesh = {Ampicillin/pharmacology ; Animals ; Anti-Bacterial Agents/*pharmacology ; Bacteria/*drug effects/growth &amp; development ; China ; Female ; Gossypium/growth &amp; development ; Hemiptera/*microbiology ; Herbivory ; Rifampin/pharmacology ; *Symbiosis ; }, abstract = {The maternally heritable endosymbiont provides many ecosystem functions. Antibiotic elimination of a specific symbiont and establishment of experimental host lines lacking certain symbionts enable the roles of a given symbiont to be explored. The whitefly Bemisia tabaci (Gennadius) in China harbors obligate symbiont Portiera infecting each individual, as well as facultative symbionts, such as Hamiltonella, Rickettsia and Cardinium, with co-infections occurring relatively frequently. So far no studies have evaluated the selectivity and efficacy of a specific symbiont elimination using antibiotics in whiteflies co-infected with different symbionts. Furthermore, no success has been achieved in establishing certain symbiont-free B. tabaci lines. In this study, we treated Hamiltonella-infected B. tabaci line, Hamiltonella-Rickettsia-co-infected line and Hamiltonella-Cardinium co-infected line by feeding B. tabaci adults with cotton plants cultured in water containing rifampicin, ampicillin or a mixture of them, aiming to selectively curing symbiont infections and establishing stable symbiont-free lines. We found ampicillin selectively eliminated Cardinium without affecting Portiera, Hamiltonella and Rickettsia, although they coexisted in the same host body. Meanwhile, all of the symbionts considered in our study can be removed by rifampicin. The reduction of facultative symbionts occurred at a much quicker pace than obligate symbiont Portiera during rifampicin treatment. Also, we measured the stability of symbiont elimination in whitefly successive generations and established Rickettsia-infected and Cardinium-infected lines which are absent in natural populations. Our results provide new protocols for selective elimination of symbionts co-existing in a host and establishment of different symbiont-infected host lines.}, }
@article {pmid31231971, year = {2020}, author = {Hsi, TE and Hsiao, SW and Minahan, NT and Yen, TY and de Assunção Carvalho, AV and Raoult, D and Fournier, PE and Tsai, KH}, title = {Seroepidemiological and molecular investigation of spotted fever group rickettsiae and Coxiella burnetii in Sao Tome Island: A One Health approach.}, journal = {Transboundary and emerging diseases}, volume = {67 Suppl 2}, number = {}, pages = {36-43}, doi = {10.1111/tbed.13191}, pmid = {31231971}, issn = {1865-1682}, mesh = {Adolescent ; Adult ; Aged ; Animals ; Antibodies, Bacterial/blood ; Antigens, Bacterial/immunology ; Cattle ; Child ; Child, Preschool ; Coxiella burnetii/genetics/immunology/*isolation &amp; purification ; Cross-Sectional Studies ; DNA, Bacterial/genetics ; Female ; Fluorescent Antibody Technique, Indirect/veterinary ; Goats ; Humans ; Infant ; Infant, Newborn ; Islands ; Male ; Middle Aged ; Molecular Biology ; One Health ; Polymerase Chain Reaction ; Q Fever/*epidemiology/veterinary ; RNA, Ribosomal/genetics ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/immunology/*isolation &amp; purification ; Sao Tome and Principe/epidemiology ; Sequence Analysis, DNA/veterinary ; Seroepidemiologic Studies ; Spotted Fever Group Rickettsiosis/*epidemiology/veterinary ; Tick-Borne Diseases/*epidemiology/veterinary ; Ticks ; }, abstract = {Spotted fever group rickettsiae (SFGR) and Coxiella burnetii are intracellular bacteria that cause potentially life-threatening tick-borne rickettsioses and Q fever respectively. Sao Tome and Principe (STP), small islands located in the Gulf of Guinea, recently experienced a dramatic reduction in the incidence of malaria owing to international collaborative efforts. However, unexplained febrile illnesses persist. A One Health approach was adopted to investigate exposure to SFGR and C. burnetii in humans and examine the diversity of these bacteria in ticks parasitizing domestic ruminants. A cross-sectional human serological study was conducted in Agua Grande district in Sao Tome Island from January to March 2016, and ticks were collected from farmed domestic ruminants in 2012 and 2016. In total, 240 individuals varying in age were randomly screened for exposure to SFGR and C. burnetii by indirect immunofluorescence assay. Twenty of 240 individuals (8.3%) were seropositive for SFGR (4 for Rickettsia africae and 16 for R. conorii) and 16 (6.7%) were seropositive for C. burnetii. Amblyomma astrion were collected exclusively in 2012, as were A. variegatum in 2016 and Rickettsia spp. were detected in 22/42 (52.4%) and 49/60 (81.7%) respectively. Sequence analysis of multiple gene targets from Rickettsia spp. detected in ticks suggests the presence of a single divergent R. africae strain (Sao Tome). While no ticks were found positive for C. burnetii, Coxiella-like endosymbionts were detected in nearly all ticks. This is the first study in STP to provide serological evidence in humans of SFGR and C. burnetii and additional molecular evidence in ticks for SFGR, which may be responsible for some of the unexplained febrile illnesses that persist despite the control of malaria. Future epidemiological studies are needed to confirm the occurrence and risk factors associated with SFG rickettsioses and Q fever in both humans and animals.}, }
@article {pmid31222094, year = {2019}, author = {Mateos, M and Silva, NO and Ramirez, P and Higareda-Alvear, VM and Aramayo, R and Erickson, JW}, title = {Effect of heritable symbionts on maternally-derived embryo transcripts.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {8847}, pmid = {31222094}, issn = {2045-2322}, support = {R03 AI078348/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Drosophila melanogaster/*embryology/genetics/*microbiology ; Embryo, Nonmammalian/*microbiology ; Female ; Genes, Insect/genetics ; Host-Pathogen Interactions/genetics ; Male ; Phenotype ; RNA, Ribosomal ; Reproduction/genetics ; Ribosome Inactivating Proteins/genetics/physiology ; Sequence Analysis, RNA ; Spiroplasma/enzymology ; *Symbiosis ; Transcriptome/*genetics ; Wolbachia ; }, abstract = {Maternally-transmitted endosymbiotic bacteria are ubiquitous in insects. Among other influential phenotypes, many heritable symbionts of arthropods are notorious for manipulating host reproduction through one of four reproductive syndromes, which are generally exerted during early developmental stages of the host: male feminization; parthenogenesis induction; male killing; and cytoplasmic incompatibility (CI). Major advances have been achieved in understanding mechanisms and identifying symbiont factors involved in reproductive manipulation, particularly male killing and cytoplasmic incompatibility. Nonetheless, whether cytoplasmically-transmitted bacteria influence the maternally-loaded components of the egg or early embryo has not been examined. In the present study, we investigated whether heritable endosymbionts that cause different reproductive phenotypes in Drosophila melanogaster influence the mRNA transcriptome of early embryos. We used mRNA-seq to evaluate differential expression in Drosophila embryos lacking endosymbionts (control) to those harbouring the male-killing Spiroplasma poulsonii strain MSRO-Br, the CI-inducing Wolbachia strain wMel, or Spiroplasma poulsonii strain Hyd1; a strain that lacks a reproductive phenotype and is naturally associated with Drosophila hydei. We found no consistent evidence of influence of symbiont on mRNA composition of early embryos, suggesting that the reproductive manipulation mechanism does not involve alteration of maternally-loaded transcripts. In addition, we capitalized on several available mRNA-seq datasets derived from Spiroplasma-infected Drosophila melanogaster embryos, to search for signals of depurination of rRNA, consistent with the activity of Ribosome Inactivating Proteins (RIPs) encoded by Spiroplasma poulsonii. We found small but statistically significant signals of depurination of Drosophila rRNA in the Spiroplasma treatments (both strains), but not in the symbiont-free control or Wolbachia treatment, consistent with the action of RIPs. The depurination signal was slightly stronger in the treatment with the male-killing strain. This result supports a recent report that RIP-induced damage contributes to male embryo death.}, }
@article {pmid31217220, year = {2019}, author = {Day, PM and Inoue, K and Theg, SM}, title = {Chloroplast Outer Membrane β-Barrel Proteins Use Components of the General Import Apparatus.}, journal = {The Plant cell}, volume = {31}, number = {8}, pages = {1845-1855}, pmid = {31217220}, issn = {1532-298X}, mesh = {Arabidopsis/genetics/*metabolism ; Arabidopsis Proteins/genetics/*metabolism ; Chloroplast Proteins/genetics/*metabolism ; Chloroplasts/*metabolism ; Membrane Proteins/genetics/metabolism ; Plant Proteins/genetics/metabolism ; Protein Transport/genetics/physiology ; Tobacco/genetics/metabolism ; }, abstract = {Chloroplasts evolved from a cyanobacterial endosymbiont that resided within a eukaryotic cell. Due to their prokaryotic heritage, chloroplast outer membranes contain transmembrane β-barrel proteins. While most chloroplast proteins use N-terminal transit peptides to enter the chloroplasts through the translocons at the outer and inner chloroplast envelope membranes (TOC/TIC), only one β-barrel protein, Toc75, has been shown to use this pathway. The route other β-barrel proteins use has remained unresolved. Here we use in vitro pea (Pisum sativum) chloroplast import assays and transient expression in Nicotiana benthamiana to address this. We show that a paralog of Toc75, outer envelope protein 80 kD (OEP80), also uses a transit peptide but has a distinct envelope sorting signal. Our results additionally indicate that β-barrels that do not use transit peptides also enter the chloroplast using components of the general import pathway.}, }
@article {pmid31214820, year = {2019}, author = {Konecka, E and Olszanowski, Z}, title = {First Evidence of Intracellular Bacteria Cardinium in Thermophilic Mite Microzetorchestes emeryi (Acari: Oribatida): Molecular Screening of Bacterial Endosymbiont Species.}, journal = {Current microbiology}, volume = {76}, number = {9}, pages = {1038-1044}, pmid = {31214820}, issn = {1432-0991}, mesh = {Animals ; Bacteroidetes/classification/*genetics/*isolation &amp; purification/physiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Mites/*microbiology/physiology ; Phylogeny ; Poland ; Symbiosis ; }, abstract = {We undertook the issue of the distribution of intracellular bacteria among Oribatida (Acari). Six genera of bacteria were detected by PCR and Sanger DNA sequencing: Wolbachia, Cardinium, Rickettsia, Spiroplasma, Arsenophonus, and Hamiltonella. Our research, for the first time, revealed the presence of Cardinium in Microzetorchestes emeryi in two subpopulations separated from each other by 300 m. The percentages of infected animals were the same in both subpopulations-ca. 20%. The identity of 16S rDNA sequences of Cardinium between these two subpopulations of M. emeryi was 97%. Phylogenetic analysis showed that the Cardinium in M. emeryi was clustered into the group A. The occurrence of M. emeryi in Poland has not been reported before and our report is the first one. Cardinium maybe help the thermophilic M. emeryi to adapt to low temperatures in the Central Europe.}, }
@article {pmid31213566, year = {2019}, author = {Van Leuven, JT and Mao, M and Xing, DD and Bennett, GM and McCutcheon, JP}, title = {Cicada Endosymbionts Have tRNAs That Are Correctly Processed Despite Having Genomes That Do Not Encode All of the tRNA Processing Machinery.}, journal = {mBio}, volume = {10}, number = {3}, pages = {}, pmid = {31213566}, issn = {2150-7511}, support = {P20 GM104420/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics ; Evolution, Molecular ; Female ; *Genome, Bacterial ; Hemiptera/*microbiology ; Phylogeny ; Protein Modification, Translational ; RNA, Transfer/*genetics ; *Symbiosis ; }, abstract = {Gene loss and genome reduction are defining characteristics of endosymbiotic bacteria. The most highly reduced endosymbiont genomes have lost numerous essential genes related to core cellular processes such as replication, transcription, and translation. Computational gene predictions performed for the genomes of the two bacterial symbionts of the cicada Diceroprocta semicincta, "Candidatus Hodgkinia cicadicola" (Alphaproteobacteria) and "Ca Sulcia muelleri" (Bacteroidetes), have found only 26 and 16 tRNA genes and 15 and 10 aminoacyl tRNA synthetase genes, respectively. Furthermore, the original "Ca Hodgkinia cicadicola" genome annotation was missing several essential genes involved in tRNA processing, such as those encoding RNase P and CCA tRNA nucleotidyltransferase as well as several RNA editing enzymes required for tRNA maturation. How these cicada endosymbionts perform basic translation-related processes remains unknown. Here, by sequencing eukaryotic mRNAs and total small RNAs, we show that the limited tRNA set predicted by computational annotation of "Ca Sulcia muelleri" and "Ca Hodgkinia cicadicola" is likely correct. Furthermore, we show that despite the absence of genes encoding tRNA processing activities in the symbiont genomes, symbiont tRNAs have correctly processed 5' and 3' ends and seem to undergo nucleotide modification. Surprisingly, we found that most "Ca Hodgkinia cicadicola" and "Ca Sulcia muelleri" tRNAs exist as tRNA halves. We hypothesize that "Ca Sulcia muelleri" and "Ca Hodgkinia cicadicola" tRNAs function in bacterial translation but require host-encoded enzymes to do so.IMPORTANCE The smallest bacterial genomes, in the range of about 0.1 to 0.5 million base pairs, are commonly found in the nutritional endosymbionts of insects. These tiny genomes are missing genes that encode proteins and RNAs required for the translation of mRNAs, one of the most highly conserved and important cellular processes. In this study, we found that the bacterial endosymbionts of cicadas have genomes which encode incomplete tRNA sets and lack genes required for tRNA processing. Nevertheless, we found that endosymbiont tRNAs are correctly processed at their 5' and 3' ends and, surprisingly, that mostly exist as tRNA halves. We hypothesize that the cicada host must supply its symbionts with these missing tRNA processing activities.}, }
@article {pmid31208002, year = {2019}, author = {Schebeck, M and Feldkirchner, L and Stauffer, C and Schuler, H}, title = {Dynamics of an Ongoing Wolbachia Spread in the European Cherry Fruit Fly, Rhagoletis cerasi (Diptera: Tephritidae).}, journal = {Insects}, volume = {10}, number = {6}, pages = {}, pmid = {31208002}, issn = {2075-4450}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Numerous terrestrial arthropods are infected with the alphaproteobacterium Wolbachia. This endosymbiont is usually transmitted vertically from infected females to their offspring and can alter the reproduction of hosts through various manipulations, like cytoplasmic incompatibility (CI), enhancing its spread in new host populations. Studies on the spatial and temporal dynamics of Wolbachia under natural conditions are scarce. Here, we analyzed Wolbachia infection frequencies in populations of the European cherry fruit fly, Rhagoletis cerasi (L.), in central Germany-an area of an ongoing spread of the CI-inducing strain wCer2. In total, 295 individuals from 19 populations were PCR-screened for the presence of wCer2 and their mitochondrial haplotype. Results were compared with historic data to understand the infection dynamics of the ongoing wCer2 invasion. An overall wCer2 infection frequency of about 30% was found, ranging from 0% to 100% per population. In contrast to an expected smooth transition from wCer2-infected to completely wCer2-uninfected populations, a relatively scattered infection pattern across geography was observed. Moreover, a strong Wolbachia-haplotype association was detected, with only a few rare misassociations. Our results show a complex dynamic of an ongoing Wolbachia spread in natural field populations of R. cerasi.}, }
@article {pmid31194893, year = {2020}, author = {Ant, TH and Herd, C and Louis, F and Failloux, AB and Sinkins, SP}, title = {Wolbachia transinfections in Culex quinquefasciatus generate cytoplasmic incompatibility.}, journal = {Insect molecular biology}, volume = {29}, number = {1}, pages = {1-8}, pmid = {31194893}, issn = {1365-2583}, support = {202888/WT_/Wellcome Trust/United Kingdom ; 202888/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; 108508/WT_/Wellcome Trust/United Kingdom ; MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; BB/K004506/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Aedes/microbiology ; Animals ; Culex/*microbiology ; Female ; Male ; Mosquito Control/methods ; Mosquito Vectors/microbiology ; Pest Control, Biological/methods ; Salivary Glands/microbiology ; Symbiosis ; Wolbachia/classification/*physiology ; }, abstract = {Culex quinquefasciatus is an important mosquito vector of a number of viral and protozoan pathogens of humans and animals, and naturally carries the endosymbiont Wolbachia pipientis, strain wPip. Wolbachia are used in two distinct vector control strategies: firstly, population suppression caused by mating incompatibilities between mass-released transinfected males and wild females; and secondly, the spread of pathogen transmission-blocking strains through populations. Using embryonic microinjection, two novel Wolbachia transinfections were generated in C. quinquefasciatus using strains native to the mosquito Aedes albopictus: a wAlbB single infection, and a wPip plus wAlbA superinfection. The wAlbB infection showed full bidirectional cytoplasmic incompatibility (CI) with wild-type C. quinquefasciatus in reciprocal crosses. The wPipwAlbA superinfection showed complete unidirectional CI, and therefore population invasion potential. Whereas the wAlbB strain showed comparatively low overall densities, similar to the native wPip, the wPipwAlbA superinfection reached over 400-fold higher densities in the salivary glands compared to the native wPip, suggesting it may be a candidate for pathogen transmission blocking.}, }
@article {pmid31191980, year = {2019}, author = {Koh, C and Audsley, MD and Di Giallonardo, F and Kerton, EJ and Young, PR and Holmes, EC and McGraw, EA}, title = {Sustained Wolbachia-mediated blocking of dengue virus isolates following serial passage in Aedes aegypti cell culture.}, journal = {Virus evolution}, volume = {5}, number = {1}, pages = {vez012}, pmid = {31191980}, issn = {2057-1577}, abstract = {Wolbachia is an intracellular endosymbiont of insects that inhibits the replication of a range of pathogens in its arthropod hosts. The release of Wolbachia into wild populations of mosquitoes is an innovative biocontrol effort to suppress the transmission of arthropod-borne viruses (arboviruses) to humans, most notably dengue virus. The success of the Wolbachia-based approach hinges upon the stable persistence of the 'pathogen blocking' effect, whose mechanistic basis is poorly understood. Evidence suggests that Wolbachia may affect viral replication via a combination of competition for host resources and activation of host immunity. The evolution of resistance against Wolbachia and pathogen blocking in the mosquito or the virus could reduce the public health impact of the symbiont releases. Here, we investigate if dengue 3 virus (DENV-3) is capable of accumulating adaptive mutations that improve its replicative capacity during serial passage in Wolbachia wMel-infected cells. During the passaging regime, viral isolates in Wolbachia-infected cells exhibited greater variation in viral loads compared to controls. The viral loads of these isolates declined rapidly during passaging due to the blocking effects of Wolbachia carriage, with several being lost all together and the remainder recovering to low but stable levels. We attempted to sequence the genomes of the surviving passaged isolates but, given their low abundance, were unable to obtain sufficient depth of coverage for evolutionary analysis. In contrast, viral loads in Wolbachia-free control cells were consistently high during passaging. The surviving isolates passaged in the presence of Wolbachia exhibited a reduced ability to replicate even in Wolbachia-free cells. These experiments demonstrate the challenge for dengue in evolving resistance to Wolbachia-mediated blocking.}, }
@article {pmid31191462, year = {2019}, author = {Purahong, W and Mapook, A and Wu, YT and Chen, CT}, title = {Characterization of the Castanopsis carlesii Deadwood Mycobiome by Pacbio Sequencing of the Full-Length Fungal Nuclear Ribosomal Internal Transcribed Spacer (ITS).}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {983}, pmid = {31191462}, issn = {1664-302X}, abstract = {Short-read next generation sequencing (NGS) platforms can easily and quickly generate thousands to hundreds of thousands of sequences per sample. However, the limited length of these sequences can cause problems during fungal taxonomic identification. Here we validate the use of Pacbio sequencing, a long-read NGS method, for characterizing the fungal community (mycobiome) of Castanopsis carlesii deadwood. We report the successful use of Pacbio sequencing to generate long-read sequences of the full-length (500-780 bp) fungal ITS regions of the C. carlesii mycobiome. Our results show that the studied deadwood mycobiome is taxonomically and functionally diverse, with an average of 85 fungal OTUs representing five functional groups (animal endosymbionts, endophytes, mycoparasites, plant pathogens, and saprotrophs). Based on relative abundance data, Basidiomycota were the most frequently detected phyla (50% of total sequences), followed by unidentified phyla, and Ascomycota. However, based on presence/absence data, the most OTU-rich phyla were Ascomycota (58% of total OTUs, 72 OTUs) followed by Basidiomycota and unidentified phyla. The majority of fungal OTUs were identified as saprotrophs (70% of successfully function-assigned OTUs) followed by plant pathogens. Finally, we used phylogenetic analysis based on the full-length ITS sequences to confirm the species identification of 14/36 OTUs with high bootstrap support (99-100%). Based on the numbers of sequence reads obtained per sample, which ranged from 3,047 to 13,463, we conclude that Pacbio sequencing can be a powerful tool for characterizing moderate- and possibly high-complexity fungal communities.}, }
@article {pmid31186513, year = {2019}, author = {Gabay, Y and Parkinson, JE and Wilkinson, SP and Weis, VM and Davy, SK}, title = {Inter-partner specificity limits the acquisition of thermotolerant symbionts in a model cnidarian-dinoflagellate symbiosis.}, journal = {The ISME journal}, volume = {13}, number = {10}, pages = {2489-2499}, pmid = {31186513}, issn = {1751-7370}, mesh = {Acclimatization ; Animals ; Dinoflagellida/*physiology ; Hot Temperature ; Models, Biological ; Sea Anemones/*physiology ; Species Specificity ; Symbiosis ; }, abstract = {The ability of corals and other cnidarians to survive climate change depends partly on the composition of their endosymbiont communities. The dinoflagellate family Symbiodiniaceae is genetically and physiologically diverse, and one proposed mechanism for cnidarians to acclimate to rising temperatures is to acquire more thermally tolerant symbionts. However, cnidarian-dinoflagellate associations vary in their degree of specificity, which may limit their capacity to alter symbiont communities. Here, we inoculated symbiont-free polyps of the sea anemone Exaiptasia pallida (commonly referred to as 'Aiptasia'), a model system for the cnidarian-dinoflagellate symbiosis, with simultaneous or sequential mixtures of thermally tolerant and thermally sensitive species of Symbiodiniaceae. We then monitored symbiont success (relative proportional abundance) at normal and elevated temperatures across two to four weeks. All anemones showed signs of bleaching at high temperature. During simultaneous inoculations, the native, thermally sensitive Breviolum minutum colonized polyps most successfully regardless of temperature when paired against the non-native but more thermally tolerant Symbiodinium microadriaticum or Durusdinium trenchii. Furthermore, anemones initially colonized with B. minutum and subsequently exposed to S. microadriaticum failed to acquire the new symbiont. These results highlight how partner specificity may place strong limitations on the ability of certain cnidarians to acquire more thermally tolerant symbionts, and hence their adaptive potential under climate change.}, }
@article {pmid31186318, year = {2019}, author = {Chrostek, E and Gerth, M}, title = {Is Anopheles gambiae a Natural Host of Wolbachia?.}, journal = {mBio}, volume = {10}, number = {3}, pages = {}, pmid = {31186318}, issn = {2150-7511}, mesh = {Africa ; Animals ; Anopheles/*microbiology ; Female ; Genome, Bacterial ; Malaria/transmission ; Male ; Metagenomics ; Mosquito Vectors/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Wolbachia/*genetics/isolation &amp; purification ; }, abstract = {Wolbachia (Alphaproteobacteria, Rickettsiales) is an intraovarially transmitted symbiont of insects able to exert striking phenotypes, including reproductive manipulations and pathogen blocking. These phenotypes make Wolbachia a promising tool to combat mosquito-borne diseases. Although Wolbachia is present in the majority of terrestrial arthropods, including many disease vectors, it was considered absent from Anopheles gambiae mosquitos, the main vectors of malaria in sub-Saharan Africa. In 2014, Wolbachia sequences were detected in A. gambiae samples collected in Burkina Faso. Subsequently, similar evidence came from collections all over Africa, revealing a high Wolbachia 16S rRNA sequence diversity, low abundance, and a lack of congruence between host and symbiont phylogenies. Here, we reanalyze and discuss recent evidence on the presence of Wolbachia sequences in A. gambiae. We find that although detected at increasing frequencies, the unusual properties of these Wolbachia sequences render them insufficient to diagnose natural infections in A. gambiae Future studies should focus on uncovering the origin of Wolbachia sequence variants in Anopheles and seeking sequence-independent evidence for this new symbiosis. Understanding the ecology of Anopheles mosquitos and their interactions with Wolbachia will be key in designing successful, integrative approaches to limit malaria spread. Although the prospect of using Wolbachia to fight malaria is intriguing, the newly discovered strains do not bring it closer to realization.IMPORTANCEAnopheles gambiae mosquitos are the main vectors of malaria, threatening around half of the world's population. The bacterial symbiont Wolbachia can interfere with disease transmission by other important insect vectors, but until recently, it was thought to be absent from natural A. gambiae populations. Here, we critically analyze the genomic, metagenomic, PCR, imaging, and phenotypic data presented in support of the presence of natural Wolbachia infections in A. gambiae We find that they are insufficient to diagnose Wolbachia infections and argue for the need of obtaining robust data confirming basic Wolbachia characteristics in this system. Determining the Wolbachia infection status of Anopheles is critical due to its potential to influence Anopheles population structure and Plasmodium transmission.}, }
@article {pmid31177395, year = {2020}, author = {Liu, H and Wu, M and Liu, J and Qu, Y and Gao, Y and Ren, A}, title = {Tripartite Interactions Between Endophytic Fungi, Arbuscular Mycorrhizal Fungi, and Leymus chinensis.}, journal = {Microbial ecology}, volume = {79}, number = {1}, pages = {98-109}, pmid = {31177395}, issn = {1432-184X}, mesh = {Endophytes/*physiology ; Glomeromycota/*physiology ; Mycorrhizae/*physiology ; Plant Roots/growth &amp; development/microbiology ; Poaceae/growth &amp; development/*microbiology ; Symbiosis ; }, abstract = {Grasses often establish multiple simultaneous symbiotic associations with endophytic fungi and arbuscular mycorrhizal fungi (AMF). Many studies have examined pair-wise interactions between plants and endophytic fungi or between plants and AMF, overlooking the interplays among multiple endosymbionts and their combined impacts on hosts. Here, we examined both the way in which each symbiont affects the other symbionts and the tripartite interactions between leaf endophytic fungi, AMF, and Leymus chinensis. As for AMF, different species (Glomus etunicatum, GE; Glomus mosseae, GM; Glomus claroideum, GC; and Glomus intraradices, GI) and AMF richness (no AMF, single AMF taxa, double AMF mixtures, triple AMF mixtures, and all four together) were considered. Our results showed that significant interactions were observed between endophytes and AMF, with endophytes interacting antagonistically with GM but synergistically with GI. No definitive interactions were observed between the endophytes and GE or GC. Additionally, the concentration of endophytes in the leaf sheath was positively correlated with the concentration of AMF in the roots under low AMF richness. The shoot biomass of L. chinensis was positively related to both endophyte concentration and AMF concentration, with only endophytes contributing to shoot biomass more than AMF. Endophytes and AMF increased shoot growth by contributing to phosphorus uptake. The interactive effects of endophytes and AMF on host growth were affected by the identity of AMF species. The beneficial effect of the endophytes decreased in response to GM but increased in response to GI. However, no influences were observed with other GC and GE. In addition, endophyte presence can alter the response of host plants to AMF richness. When leaf endophytes were absent, shoot biomass increased with higher AMF richness, only the influence of AMF species identity outweighed that of AMF richness. However, when leaf endophytes were present, no significant association was observed between AMF richness and shoot biomass. AMF species identity rather than AMF richness promoted shoot growth. The results of this study demonstrate that the outcomes of interspecific symbiotic interactions are very complex and vary with partner identity such that the effects of simultaneous symbioses cannot be generalized and highlight the need for studies to evaluate fitness response of all three species, as the interactive effects may not be the same for each partner.}, }
@article {pmid31176662, year = {2019}, author = {Olivieri, E and Epis, S and Castelli, M and Varotto Boccazzi, I and Romeo, C and Desirò, A and Bazzocchi, C and Bandi, C and Sassera, D}, title = {Tissue tropism and metabolic pathways of Midichloria mitochondrii suggest tissue-specific functions in the symbiosis with Ixodes ricinus.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {5}, pages = {1070-1077}, doi = {10.1016/j.ttbdis.2019.05.019}, pmid = {31176662}, issn = {1877-9603}, mesh = {Animals ; Computer Simulation ; Female ; *Genome, Bacterial ; Italy ; Ixodes/*microbiology ; *Metabolic Networks and Pathways ; Rickettsiales/genetics/metabolism/*physiology ; *Symbiosis ; *Viral Tropism ; }, abstract = {A wide range of arthropod species harbour bacterial endosymbionts in various tissues, many of them playing important roles in the fitness and biology of their hosts. In several cases, many different symbionts have been reported to coexist simultaneously within the same host and synergistic or antagonistic interactions can occur between them. While the associations with endosymbiotic bacteria have been widely studied in many insect species, in ticks such interactions are less investigated. The females and immatures of Ixodes ricinus (Ixodidae), the most common hard tick in Europe, harbour the intracellular endosymbiont "Candidatus Midichloria mitochondrii" with a prevalence up to 100%, suggesting a mutualistic relationship. Considering that the tissue distribution of a symbiont might be indicative of its functional role in the physiology of the host, we investigated M. mitochondrii specific localization pattern and the corresponding abundance in selected organs of I. ricinus females. We paired these experiments with in silico analysis of the metabolic pathways of M. mitochondrii, inferred from the available genome sequence, and additionally compared the presence of these pathways in seven other symbionts commonly harboured by ticks to try to obtain a comparative understanding of their biological effects on the tick hosts. M. mitochondrii was found to be abundant in ovaries and tracheae of unfed I. ricinus, and in ovaries, Malpighian tubules and salivary glands of semi-engorged females. These results, together with the in silico metabolic reconstruction allow to hypothesize that the bacterium could play multiple tissue-specific roles in the host, both enhancing the host fitness (supplying essential nutrients, enhancing the reproductive fitness, helping in the anti-oxidative defence, in the energy production and in the maintenance of homeostasis and water balance) and/or for ensuring its presence in the host population (nutrients acquisition, vertical and horizontal transmission). The ability of M. mitochondrii to colonize different tissues allows to speculate that distinctive sub-populations may display different specializations in accordance with tissue tropism. Our hypotheses should be corroborated with future nutritional and physiological experiments for a better understanding of the mechanisms underlying this symbiotic interaction.}, }
@article {pmid31173475, year = {2020}, author = {Xie, K and Lu, YJ and Yang, K and Huo, SM and Hong, XY}, title = {Co-infection of Wolbachia and Spiroplasma in spider mite Tetranychus truncatus increases male fitness.}, journal = {Insect science}, volume = {27}, number = {5}, pages = {921-937}, pmid = {31173475}, issn = {1744-7917}, mesh = {Animals ; *Genetic Fitness ; Male ; Spiroplasma/*physiology ; *Symbiosis ; Tetranychidae/*genetics/microbiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia and Spiroplasma are intracellular bacteria that are of great interest to entomologists, because of their ability to alter insect host biology in multiple ways. In the spider mite Tetranychus truncatus, co-infection of Wolbachia and Spiroplasma can induce cytoplasmic incompatibility (CI) and fitness costs; however, little is known about the effect of co-infection at the genetic level and the molecular mechanisms underlying CI. In this study, we explored the influence of the two symbionts on male mite host fitness and used RNA sequencing to generate the transcriptomes of T. truncatus with four different types of infection. In total, we found symbiont-infected lines had a higher hatch proportion than the uninfected line, and the development time of the uninfected line was longer than that of the other lines. Co-infection changed the expression of many genes related to digestion detoxification, reproduction, immunity and oxidation reduction. Our results indicate that co-infection of Wolbachia and Spiroplasma confers multiple effects on their hosts, and helps illuminate the complex interactions between endosymbionts and arthropods.}, }
@article {pmid31167958, year = {2020}, author = {Wilson, JR and DeBlasio, SL and Alexander, MM and Heck, M}, title = {Looking Through the Lens of 'Omics Technologies: Insights Into the Transmission of Insect Vector-borne Plant Viruses.}, journal = {Current issues in molecular biology}, volume = {34}, number = {}, pages = {113-144}, doi = {10.21775/cimb.034.113}, pmid = {31167958}, issn = {1467-3045}, mesh = {Animals ; *Disease Transmission, Infectious ; Genome, Insect ; *Genomics/methods ; *Host-Pathogen Interactions ; Insect Proteins ; Insect Vectors/*virology ; Plant Diseases/*virology ; Plant Viruses/*physiology ; Proteomics/methods ; }, abstract = {Insects in the orders Hemiptera and Thysanoptera transmit viruses and other pathogens associated with the most serious diseases of plants. Plant viruses transmitted by these insects target similar tissues, genes, and proteins within the insect to facilitate plant-to-plant transmission with some degree of specificity at the molecular level. 'Omics experiments are becoming increasingly important and practical for vector biologists to use towards better understanding the molecular mechanisms and biochemistry underlying transmission of these insect-borne diseases. These discoveries are being used to develop novel means to obstruct virus transmission into and between plants. In this chapter, we summarize 'omics technologies commonly applied in vector biology and the important discoveries that have been made using these methods, including virus and insect proteins involved in transmission, as well as the tri-trophic interactions involved in host and vector manipulation. Finally, we critically examine the limitations and new horizons in this area of research, including the role of endosymbionts and insect viruses in virus-vector interactions, and the development of novel control strategies.}, }
@article {pmid31163164, year = {2019}, author = {Havird, JC and Forsythe, ES and Williams, AM and Werren, JH and Dowling, DK and Sloan, DB}, title = {Selfish Mitonuclear Conflict.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R496-R511}, pmid = {31163164}, issn = {1879-0445}, support = {F32 GM116361/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacterial Physiological Phenomena ; *Biological Evolution ; Eukaryota/physiology ; Genome, Mitochondrial/*physiology ; Plastids/physiology ; Symbiosis/physiology ; }, abstract = {Mitochondria, a nearly ubiquitous feature of eukaryotes, are derived from an ancient symbiosis. Despite billions of years of cooperative coevolution - in what is arguably the most important mutualism in the history of life - the persistence of mitochondrial genomes also creates conditions for genetic conflict with the nucleus. Because mitochondrial genomes are present in numerous copies per cell, they are subject to both within- and among-organism levels of selection. Accordingly, 'selfish' genotypes that increase their own proliferation can rise to high frequencies even if they decrease organismal fitness. It has been argued that uniparental (often maternal) inheritance of cytoplasmic genomes evolved to curtail such selfish replication by minimizing within-individual variation and, hence, within-individual selection. However, uniparental inheritance creates conditions for cytonuclear conflict over sex determination and sex ratio, as well as conditions for sexual antagonism when mitochondrial variants increase transmission by enhancing maternal fitness but have the side-effect of being harmful to males (i.e., 'mother's curse'). Here, we review recent advances in understanding selfish replication and sexual antagonism in the evolution of mitochondrial genomes and the mechanisms that suppress selfish interactions, drawing parallels and contrasts with other organelles (plastids) and bacterial endosymbionts that arose more recently. Although cytonuclear conflict is widespread across eukaryotes, it can be cryptic due to nuclear suppression, highly variable, and lineage-specific, reflecting the diverse biology of eukaryotes and the varying architectures of their cytoplasmic genomes.}, }
@article {pmid31163163, year = {2019}, author = {McCutcheon, JP and Boyd, BM and Dale, C}, title = {The Life of an Insect Endosymbiont from the Cradle to the Grave.}, journal = {Current biology : CB}, volume = {29}, number = {11}, pages = {R485-R495}, doi = {10.1016/j.cub.2019.03.032}, pmid = {31163163}, issn = {1879-0445}, support = {R01 AI095736/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Bacterial Physiological Phenomena ; Enterobacteriaceae/*physiology ; Fungi/*physiology ; Insecta/*microbiology ; Symbiosis/*physiology ; }, abstract = {Host-beneficial endosymbioses, which are formed when a microorganism takes up residence inside another cell and provides a fitness advantage to the host, have had a dramatic influence on the evolution of life. These intimate relationships have yielded the mitochondrion and the plastid (chloroplast) - the ancient organelles that in part define eukaryotic life - along with many more recent associations involving a wide variety of hosts and microbial partners. These relationships are often envisioned as stable associations that appear cooperative and persist for extremely long periods of time. But recent evidence suggests that this stable state is often born from turbulent and conflicting origins, and that the apparent stability of many beneficial endosymbiotic relationships - although certainly real in many cases - is not an inevitable outcome of these associations. Here we review how stable endosymbioses form, how they are maintained, and how they sometimes break down and are reborn. We focus on relationships formed by insects and their resident microorganisms because these symbioses have been the focus of significant empirical work over the last two decades. We review these relationships over five life stages: origin, birth, middle age, old age, and death.}, }
@article {pmid31159272, year = {2019}, author = {Gichuhi, J and Khamis, FM and Van den Berg, J and Ekesi, S and Herren, JK}, title = {Unexpected Diversity of Wolbachia Associated with Bactrocera dorsalis (Diptera: Tephritidae) in Africa.}, journal = {Insects}, volume = {10}, number = {6}, pages = {}, pmid = {31159272}, issn = {2075-4450}, abstract = {Bactrocera dorsalis (Hendel) is an important pest of fruit-bearing plants in many countries worldwide. In Africa, this pest has spread rapidly and has become widely established since the first invasion report in 2003. Wolbachia is a vertically transmitted endosymbiont that can significantly influence aspects of the biology and, in particular, the reproduction of its host. In this study, we screened B. dorsalis specimens collected from several locations in Africa between 2005 and 2017 for Wolbachia using a PCR-based assay to target the Wolbachia surface protein wsp. Of the 357 individuals tested, 10 were positive for Wolbachia using the wsp assay. We identified four strains of Wolbachia infecting two B. dorsalis mitochondrial haplotypes. We found no strict association between the infecting strain and host haplotype, with one strain being present in two different host haplotypes. All the detected strains belonged to Super Group B Wolbachia and did not match any strains reported previously in B. dorsalis in Asia. These findings indicate that diverse Wolbachia infections are present in invasive populations of B. dorsalis.}, }
@article {pmid31151922, year = {2019}, author = {Petersen, A and Rosenstierne, MW and Rasmussen, M and Fuursted, K and Nielsen, HV and O'Brien Andersen, L and Bødker, R and Fomsgaard, A}, title = {Field samplings of Ixodes ricinus ticks from a tick-borne encephalitis virus micro-focus in Northern Zealand, Denmark.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {5}, pages = {1028-1032}, doi = {10.1016/j.ttbdis.2019.05.005}, pmid = {31151922}, issn = {1877-9603}, mesh = {Animals ; Denmark ; Encephalitis Viruses, Tick-Borne/*isolation &amp; purification ; Female ; Ixodes/growth &amp; development/*virology ; Male ; Nymph/growth &amp; development/virology ; }, abstract = {In 2008-2009 a tick-borne encephalitis virus (TBEV) micro-focus was detected in Northern Zealand, Denmark. No new cases of TBE with an epidemiological link to Northern Zealand has been reported since. Here we undertook to investigate Ixodes ricinus ticks from this endemic micro-focus in 2016 and 2017. In addition to TBEV, I. ricinus ticks may host other pathogens that include Borrelia spp., Babesia spp., Rickettsia spp. and Neoehrlichia mikurensis, together with various endosymbiont microorganisms. To detect multiple organisms we used a metagenomics PanVirus microarray and next-generation sequencing to examine the persistence and evolution of other emerging viruses, bacteria and parasites. Here we report the rise and fall of the Danish TBEV micro-focus in Northern Zealand. However, we identify for the first time in Danish I. ricinus ticks the presence of Uukuniemi virus in addition to a tick-borne phlebovirus and a range of bacteria.}, }
@article {pmid31150542, year = {2019}, author = {Aguilar-Rodríguez, J and Fares, MA and Wagner, A}, title = {Chaperonin overproduction and metabolic erosion caused by mutation accumulation in Escherichia coli.}, journal = {FEMS microbiology letters}, volume = {366}, number = {10}, pages = {}, doi = {10.1093/femsle/fnz121}, pmid = {31150542}, issn = {1574-6968}, mesh = {Carbon/metabolism ; Chaperonin 60/*genetics/metabolism ; Directed Molecular Evolution ; Escherichia coli/*genetics/*metabolism ; Genome, Bacterial ; *Mutation Accumulation ; *Phenotype ; *Symbiosis ; }, abstract = {Bacterial cells adapting to a constant environment tend to accumulate mutations in portions of their genome that are not maintained by selection. This process has been observed in bacteria evolving under strong genetic drift, and especially in bacterial endosymbionts of insects. Here, we study this process in hypermutable Escherichia coli populations evolved through 250 single-cell bottlenecks on solid rich medium in a mutation accumulation experiment that emulates the evolution of bacterial endosymbionts. Using phenotype microarrays monitoring metabolic activity in 95 environments distinguished by their carbon sources, we observe how mutation accumulation has decreased the ability of cells to metabolize most carbon sources. We study if the chaperonin GroEL, which is naturally overproduced in bacterial endosymbionts, can ameliorate the process of metabolic erosion, because of its known ability to buffer destabilizing mutations in metabolic enzymes. Our results indicate that GroEL can slow down the negative phenotypic consequences of genome decay in some environments.}, }
@article {pmid31144269, year = {2019}, author = {de Alencar Menezes Júnior, I and Feitosa de Matos, G and Moura de Freitas, K and da Conceição Jesus, E and Rouws, LFM}, title = {Occurrence of diverse Bradyrhizobium spp. in roots and rhizospheres of two commercial Brazilian sugarcane cultivars.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {50}, number = {3}, pages = {759-767}, pmid = {31144269}, issn = {1678-4405}, mesh = {Bradyrhizobium/classification/genetics/*isolation &amp; purification ; Brazil ; DNA, Bacterial/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizosphere ; Root Nodules, Plant/*microbiology ; Saccharum/*microbiology ; Vigna/growth &amp; development/microbiology ; }, abstract = {The genus Bradyrhizobium harbors many endosymbionts of legumes, but recent research has shown their widespread presence in soils and in non-legumes, notably in roots of sugarcane. This study aimed to investigate the Bradyrhizobium sp. community density in the endosphere and the rhizosphere of two commercial sugarcane cultivars. Samples of the rhizosphere and root endosphere of two Brazilian sugarcane cultivars (RB867515 and IACSP95-5000) were collected, serially diluted, and inoculated on axenic cowpea (Vigna unguiculata) and the induction of nodules was evaluated. Based on the results, a density was estimated of at least 1.6 × 10[4] rhizobia g root[-1] in rhizosphere samples and up to 105 rhizobia g root [-1] in endosphere. BOX-PCR profiling of 93 Bradyrhizobium isolates revealed genetic variability, with some dominant (up to 18 representants) and less dominant genotypes. 16S rRNA and ITS sequence analyses confirmed nine phylotypes, six of which pertained to the B. elkanii clade and three to the B. japonicum clade. Five isolates were genetically similar to the recently described species B. sacchari. There was no effect of the factors "plant cultivar" and "root compartment" on Bradyrhizobium sp. community composition and the most abundant genotypes occurred both in rhizosphere and endosphere of both cultivars. Therefore, this study confirms the natural presence of diverse Bradyrhizobium spp. in sugarcane root systems (mainly the rhizosphere) and indicates that certain Bradyrhizobium phylotypes have a special affinity for sugarcane root colonization.}, }
@article {pmid31140970, year = {2019}, author = {Lynn-Bell, NL and Strand, MR and Oliver, KM}, title = {Bacteriophage acquisition restores protective mutualism.}, journal = {Microbiology (Reading, England)}, volume = {165}, number = {9}, pages = {985-989}, doi = {10.1099/mic.0.000816}, pmid = {31140970}, issn = {1465-2080}, mesh = {Animals ; Aphids/*microbiology ; *Bacteriophages ; DNA Transposable Elements ; Disease Transmission, Infectious ; Enterobacteriaceae/*virology ; Host-Parasite Interactions ; *Symbiosis ; Wasps ; }, abstract = {Insects are frequently infected with inherited facultative symbionts known to provide a range of conditionally beneficial services, including host protection. Pea aphids (Acyrthosiphon pisum) often harbour the bacterium Hamiltonella defensa, which together with its associated bacteriophage A. pisum secondary endosymbiont (APSE) confer protection against an important natural enemy, the parasitic wasp Aphidius ervi. Previous studies showed that spontaneous loss of phage APSE resulted in the complete loss of the protective phenotype. Here, we demonstrate that APSEs can be experimentally transferred into phage-free (i.e. non-protecting) Hamiltonella strains. Unexpectedly, trials using injections of phage particles alone failed, with successful transfer occurring only when APSE and Hamiltonella were simultaneously injected. After transfer, stable establishment of APSE fully restored anti-parasitoid defenses. Thus, phages associated with heritable bacterial symbionts can move horizontally among symbiont strains facilitating the rapid transfer of ecologically important traits although natural barriers may preclude regular exchange.}, }
@article {pmid31134764, year = {2019}, author = {Purahong, W and Pietsch, KA and Bruelheide, H and Wirth, C and Buscot, F and Wubet, T}, title = {Potential links between wood-inhabiting and soil fungal communities: Evidence from high-throughput sequencing.}, journal = {MicrobiologyOpen}, volume = {8}, number = {9}, pages = {e00856}, pmid = {31134764}, issn = {2045-8827}, mesh = {Animals ; China ; Forests ; Fungi/*classification/*genetics ; High-Throughput Nucleotide Sequencing ; Metagenomics ; *Mycobiome ; Pinus ; *Soil Microbiology ; Wood/*microbiology ; }, abstract = {Wood-inhabiting fungi (WIF) are pivotal to wood decomposition, which in turn strongly influences nutrient dynamics in forest soils. However, their dispersal mechanisms remain unclear. We hypothesized that the majority of WIF are soil-borne. For this reason, the presented research aimed to quantify the contribution of soil as a source and medium for the dispersal of WIF to deadwood using high-throughput sequencing. We tested effects of tree species (specifically Schima superba and Pinus massoniana) on the percentage of WIF shared between soil and deadwood in a Chinese subtropical forest ecosystem. We also assessed the taxonomic and ecological functional group affiliations of the fungal community shared between soil and deadwood. Our results indicate that soil is a major route for WIF colonization as 12%-15% (depending on the tree species) of soil fungi were simultaneously detected in deadwood. We also demonstrate that tree species (p < 0.01) significantly shapes the composition of the shared soil and deadwood fungal community. The pH of decomposing wood was shown to significantly correspond (p < 0.01) with the shared community of wood-inhabiting (of both studied tree species) and soil fungi. Furthermore, our data suggest that a wide range of fungal taxonomic (Rozellida, Zygomycota, Ascomycota, and Basidiomycota) and ecological functional groups (saprotrophs, ectomycorrhizal, mycoparasites, and plant pathogens) may use soil as a source and medium for transport to deadwood in subtropical forest ecosystem. While 12%-62% of saprotrophic, ectomycorrhizal, and mycoparasitic WIF may utilize soil to colonize deadwood, only 5% of the detected plant pathogens were detected in both soil and deadwood, implying that these fungi use other dispersal routes. Animal endosymbionts and lichenized WIF were not detected in the soil samples. Future studies should consider assessing the relative contributions of other possible dispersal mechanisms (e.g. wind, water splash, water dispersal, animal dispersal, and mycelial network) in the colonization of deadwood by soil fungi.}, }
@article {pmid31134014, year = {2019}, author = {Wasala, SK and Brown, AMV and Kang, J and Howe, DK and Peetz, AB and Zasada, IA and Denver, DR}, title = {Variable Abundance and Distribution of Wolbachia and Cardinium Endosymbionts in Plant-Parasitic Nematode Field Populations.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {964}, pmid = {31134014}, issn = {1664-302X}, abstract = {The bacterial endosymbiont Wolbachia interacts with different invertebrate hosts, engaging in diverse symbiotic relationships. Wolbachia is often a reproductive parasite in arthropods, but an obligate mutualist in filarial nematodes. Wolbachia was recently discovered in plant-parasitic nematodes, and, is thus far known in just two genera Pratylenchus and Radopholus, yet the symbiont's function remains unknown. The occurrence of Wolbachia in these economically important plant pests offers an unexplored biocontrol strategy. However, development of Wolbachia-based biocontrol requires an improved understanding of symbiont-host functional interactions and the symbiont's prevalence among nematode field populations. This study used a molecular-genetic approach to assess the prevalence of a Wolbachia lineage (wPpe) in 32 field populations of Pratylenchus penetrans. Populations were examined from eight different plant species in Washington, Oregon, and California. Nematodes were also screened for the endosymbiotic bacterium Cardinium (cPpe) that was recently shown to co-infect P. penetrans. Results identified wPpe in 9/32 and cPpe in 1/32 of P. penetrans field populations analyzed. No co-infection was observed in field populations. Wolbachia was detected in nematodes from 4/8 plant-hosts examined (raspberry, strawberry, clover, and lily), and in all three states surveyed. Cardinium was detected in nematodes from mint in Washington. In the wPpe-infected P. penetrans populations collected from raspberry, the prevalence of wPpe infection ranged from 11 to 58%. This pattern is unlike that in filarial nematodes where Wolbachia is an obligate mutualist and occurs in 100% of the host. Further analysis of wPpe-infected populations revealed female-skewed sex ratios (up to 96%), with the degree of skew positively correlating with wPpe prevalence. Uninfected nematode populations had approximately equal numbers of males and females. Comparisons of 54 wPpe 16S ribosomal RNA sequences revealed high similarity across the geographic isolates, with 45 of 54 isolates being identical at this locus. The complete absence of wPpe among some populations and low prevalence in others suggest that this endosymbiont is not an obligate mutualist of P. penetrans. The observed sex ratio bias in wPpe-infected nematode populations is similar to that observed in arthropods where Wolbachia acts as a reproductive manipulator, raising the question of a similar role in plant-parasitic nematodes.}, }
@article {pmid31134003, year = {2019}, author = {Fernández, N and Cabrera, JJ and Varadarajan, AR and Lutz, S and Ledermann, R and Roschitzki, B and Eberl, L and Bedmar, EJ and Fischer, HM and Pessi, G and Ahrens, CH and Mesa, S}, title = {An Integrated Systems Approach Unveils New Aspects of Microoxia-Mediated Regulation in Bradyrhizobium diazoefficiens.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {924}, pmid = {31134003}, issn = {1664-302X}, abstract = {The adaptation of rhizobia from the free-living state in soil to the endosymbiotic state comprises several physiological changes in order to cope with the extremely low oxygen availability (microoxia) within nodules. To uncover cellular functions required for bacterial adaptation to microoxia directly at the protein level, we applied a systems biology approach on the key rhizobial model and soybean endosymbiont Bradyrhizobium diazoefficiens USDA 110 (formerly B. japonicum USDA 110). As a first step, the complete genome of B. diazoefficiens 110spc4, the model strain used in most prior functional genomics studies, was sequenced revealing a deletion of a ~202 kb fragment harboring 223 genes and several additional differences, compared to strain USDA 110. Importantly, the deletion strain showed no significantly different phenotype during symbiosis with several host plants, reinforcing the value of previous OMICS studies. We next performed shotgun proteomics and detected 2,900 and 2,826 proteins in oxically and microoxically grown cells, respectively, largely expanding our knowledge about the inventory of rhizobial proteins expressed in microoxia. A set of 62 proteins was significantly induced under microoxic conditions, including the two nitrogenase subunits NifDK, the nitrogenase reductase NifH, and several subunits of the high-affinity terminal cbb 3 oxidase (FixNOQP) required for bacterial respiration inside nodules. Integration with the previously defined microoxia-induced transcriptome uncovered a set of 639 genes or proteins uniquely expressed in microoxia. Finally, besides providing proteogenomic evidence for novelties, we also identified proteins with a regulation similar to that of FixK2: transcript levels of these protein-coding genes were significantly induced, while the corresponding protein abundance remained unchanged or was down-regulated. This suggested that, apart from fixK 2, additional B. diazoefficiens genes might be under microoxia-specific post-transcriptional control. This hypothesis was indeed confirmed for several targets (HemA, HemB, and ClpA) by immunoblot analysis.}, }
@article {pmid31132110, year = {2019}, author = {Hammer, TJ and Sanders, JG and Fierer, N}, title = {Not all animals need a microbiome.}, journal = {FEMS microbiology letters}, volume = {366}, number = {10}, pages = {}, doi = {10.1093/femsle/fnz117}, pmid = {31132110}, issn = {1574-6968}, mesh = {Animals ; *Gastrointestinal Microbiome ; *Host Microbial Interactions ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {It is often taken for granted that all animals host and depend upon a microbiome, yet this has only been shown for a small proportion of species. We propose that animals span a continuum of reliance on microbial symbionts. At one end are the famously symbiont-dependent species such as aphids, humans, corals and cows, in which microbes are abundant and important to host fitness. In the middle are species that may tolerate some microbial colonization but are only minimally or facultatively dependent. At the other end are species that lack beneficial symbionts altogether. While their existence may seem improbable, animals are capable of limiting microbial growth in and on their bodies, and a microbially independent lifestyle may be favored by selection under some circumstances. There is already evidence for several 'microbiome-free' lineages that represent distantly related branches in the animal phylogeny. We discuss why these animals have received such little attention, highlighting the potential for contaminants, transients, and parasites to masquerade as beneficial symbionts. We also suggest ways to explore microbiomes that address the limitations of DNA sequencing. We call for further research on microbiome-free taxa to provide a more complete understanding of the ecology and evolution of macrobe-microbe interactions.}, }
@article {pmid31126748, year = {2019}, author = {Sánchez-Montes, S and Isaak-Delgado, AB and Guzmán-Cornejo, C and Rendón-Franco, E and Muñoz-García, CI and Bermúdez, S and Morales-Diaz, J and Cruz-Romero, A and Romero-Salas, D and Dzul-Rosado, K and Lugo-Caballero, C and Colunga-Salas, P and Becker, I}, title = {Rickettsia species in ticks that parasitize amphibians and reptiles: Novel report from Mexico and review of the worldwide record.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {5}, pages = {987-994}, doi = {10.1016/j.ttbdis.2019.04.013}, pmid = {31126748}, issn = {1877-9603}, mesh = {*Amphibians ; Animals ; *Host-Parasite Interactions ; Mexico/epidemiology ; *Reptiles ; Rickettsia/classification/*isolation &amp; purification/physiology ; Tick Infestations/epidemiology/parasitology/*veterinary ; Ticks/*microbiology ; }, abstract = {Ticks are obligate haematophagous ectoparasites that are associated with a wide range of vertebrate hosts, among them also reptiles and amphibians. They have dynamic ecological interactions with multiple microorganisms, ranging from endosymbionts to pathogens, such as the members of the genus Rickettsia. The aim of this work was to detect Rickettsia in ticks from amphibians and reptiles from southern Mexico by the amplification, sequencing and phylogenetic reconstruction of the gltA and ompA genes, and also to compile all the published records worldwide of Rickettsia associated with ticks attached to reptiles and amphibians, in order to elucidate the host-parasite relationships, and to identify the geographical distribution of each bacterial species. We record for the first time the presence of Rickettsia sp. strain Colombianensi and Rickettsia amblyommatis in ticks from several reptiles and amphibians collected in three new localities from the states of Guerrero and Veracruz, Mexico. Additionally, we here report 23 Rickettsia taxa associated with 18 tick species attached to 42 host taxa of amphibians and reptiles in 36 countries. Our findings increase the inventory of rickettsia reported in Mexico and summarizes the knowledge of these bacteria associated with ticks of this particular group of vertebrate host worldwide.}, }
@article {pmid31124562, year = {2019}, author = {Zauner, S and Heimerl, T and Moog, D and Maier, UG}, title = {The Known, the New, and a Possible Surprise: A Re-Evaluation of the Nucleomorph-Encoded Proteome of Cryptophytes.}, journal = {Genome biology and evolution}, volume = {11}, number = {6}, pages = {1618-1629}, pmid = {31124562}, issn = {1759-6653}, mesh = {Chromatin ; Chromosomes ; Cryptophyta/*cytology/*genetics ; Open Reading Frames ; Proteome/genetics ; }, abstract = {Nucleomorphs are small nuclei that evolved from the nucleus of former eukaryotic endosymbionts of cryptophytes and chlorarachniophytes. These enigmatic organelles reside in their complex plastids and harbor the smallest and most compacted eukaryotic genomes investigated so far. Although the coding capacity of the nucleomorph genomes is small, a significant percentage of the encoded proteins (predicted nucleomorph-encoded proteins, pNMPs) is still not functionally annotated. We have analyzed pNMPs with unknown functions via Phyre2, a bioinformatic tool for prediction and modeling of protein structure, resulting in a functional annotation of 215 pNMPs out of 826 uncharacterized open reading frames of cryptophytes. The newly annotated proteins are predicted to participate in nucleomorph-specific functions such as chromosome organization and expression, as well as in modification and degradation of nucleomorph-encoded proteins. Additionally, we have functionally assigned nucleomorph-encoded, putatively plastid-targeted proteins among the reinvestigated pNMPs. Hints for a putative function in the periplastid compartment, the cytoplasm surrounding the nucleomorphs, emerge from the identification of pNMPs that might be homologs of endomembrane system-related proteins. These proteins are discussed in respect to their putative functions.}, }
@article {pmid31124129, year = {2019}, author = {El-Deeb, O}, title = {Digest: Fitness costs of Spiroplasma infection in pea aphids.}, journal = {Evolution; international journal of organic evolution}, volume = {73}, number = {7}, pages = {1490-1491}, doi = {10.1111/evo.13763}, pmid = {31124129}, issn = {1558-5646}, mesh = {Animals ; *Aphids ; Cost-Benefit Analysis ; Peas ; *Spiroplasma ; Symbiosis ; }, abstract = {Endosymbionts sometimes help their hosts resist parasites, but does infection of pea aphids (Acyrthosiphon pisum) with different strains of the endosymbiont Spiroplasma confer fitness benefits that offset the costs? Mathé-Hubert et al. found that across four life-history traits, Spiroplasma infection induced negative effects on host fitness when compared to controls. Only two of 12 strains of Spiroplasma showed a marginal protective effect against host parasitism by Aphidius ervi, implying Spiroplasma infection is almost entirely detrimental to pea aphid host fitness.}, }
@article {pmid31120156, year = {2020}, author = {Chouin-Carneiro, T and Ant, TH and Herd, C and Louis, F and Failloux, AB and Sinkins, SP}, title = {Wolbachia strain wAlbA blocks Zika virus transmission in Aedes aegypti.}, journal = {Medical and veterinary entomology}, volume = {34}, number = {1}, pages = {116-119}, pmid = {31120156}, issn = {1365-2915}, support = {202888/WT_/Wellcome Trust/United Kingdom ; ZK/16-021/MRC_/Medical Research Council/United Kingdom ; 202888/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; 108508/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/*microbiology/*virology ; Animals ; Female ; Mosquito Vectors/microbiology/virology ; Wolbachia/*physiology ; Zika Virus/physiology ; Zika Virus Infection/*transmission ; }, abstract = {Transinfections of the maternally transmitted endosymbiont Wolbachia pipientis can reduce RNA virus replication and prevent transmission by Aedes aegypti, and also have the capacity to invade wild-type populations, potentially reaching and maintaining high infection frequencies. Levels of virus transmission blocking are positively correlated with Wolbachia intracellular density. Despite reaching high densities in Ae. aegypti, transinfections of wAlbA, a strain native to Aedes albopictus, showed no blocking of Semliki Forest Virus in previous intrathoracic injection challenges. To further characterize wAlbA blocking in Ae. aegypti, adult females were intrathoracically challenged with Zika (ZIKV) and dengue viruses, and then fed a ZIKV-containing bloodmeal. No blocking was observed with either virus when challenged by intrathoracic injection. However, when ZIKV was delivered orally, wAlbA-infected females showed a significant reduction in viral replication and dissemination compared with uninfected controls, as well as a complete absence of virus in saliva. Although other Wolbachia strains have been shown to cause more robust viral blocking in Ae. aegypti, these findings demonstrate that, in principle, wAlbA could be used to reduce virus transmission in this species. Moreover, the results highlight the potential for underestimation of the strength of virus-blocking when based on intrathoracic injection compared with more natural oral challenges.}, }
@article {pmid31115477, year = {2019}, author = {Gómez-Díaz, JS and Montoya-Lerma, J and Muñoz Valencia, V}, title = {Prevalence and Diversity of Endosymbionts in Cassava Whiteflies (Hemiptera: Aleyrodidae) From Colombia.}, journal = {Journal of insect science (Online)}, volume = {19}, number = {3}, pages = {}, pmid = {31115477}, issn = {1536-2442}, mesh = {Animals ; Hemiptera/genetics/*microbiology ; Manihot ; Nymph/microbiology ; Phylogeny ; Symbiosis ; }, abstract = {Whiteflies cause huge economic losses for cassava (Manihot esculenta Crantz) cultivation. Damage can be caused directly when the insects feed on the phloem and/or indirectly by the transmission of viruses. It has been found that whiteflies maintain a close relationship with some endosymbiotic bacteria and that this interaction produces different effects on host biology and can also facilitate viral transmission. This study aimed to characterize the diversity of secondary endosymbionts (SE) present in whiteflies associated with cassava. Whitefly adults and nymphs were collected from cassava crops at nine locations in Southwestern Colombia. Molecular identification of insects and endosymbionts was carried out using specific mtCOI, wsp, 23s rRNA, and 16s rRNA primers. Phylogenetic trees were constructed from these sequences, both for whitefly species and the endosymbionts found. In addition, morphological identification of whitefly species was made using last instar nymphs. Molecular and morphological evaluation revealed that the most abundant whitefly species was Trialeurodes variabilis (Quaintance) followed by Aleurotrachelus socialis Bondar and Bemisia tuberculata Bondar. One hundred percent of the individuals contained the primary endosymbiont Portiera. The SE Rickettsia, Hamiltonella, Wolbachia, and Fritschea were not detected in the samples tested. Prevalence of Cardinium and Arsenophonus were variable at each locality, Cardinium being most prevalent in A. socialis adults. This study is the first report on the presence of Cardinium and Arsenophonus in A. socialis and T. variabilis. It is also the first report of endosymbiotic diversity in whiteflies associated with cassava in Colombia.}, }
@article {pmid31113635, year = {2019}, author = {Monticelli, LS and Outreman, Y and Frago, E and Desneux, N}, title = {Impact of host endosymbionts on parasitoid host range - from mechanisms to communities.}, journal = {Current opinion in insect science}, volume = {32}, number = {}, pages = {77-82}, doi = {10.1016/j.cois.2018.11.005}, pmid = {31113635}, issn = {2214-5753}, mesh = {Animals ; Appetitive Behavior ; Bacteria ; Bacterial Physiological Phenomena ; Insecta/*microbiology/*parasitology/physiology ; Symbiosis ; }, abstract = {In insects, bacterial endosymbionts are known to influence the ecology of their hosts by modifying interactions with natural enemies such as parasitoids. Symbionts can modulate both parasitoid behavioral and/or physiological traits as well as host behaviors and life-history traits. Together these suggest that endosymbionts may impact the host range of parasitoids. For example, endosymbionts may narrow parasitoid host range through first, reducing parasitoid ability to locate hosts and/or larval survival, second, affecting fitness traits of the emerging adult parasitoid and/or third, modulating the outcome of interference and exploitative competition between parasitoid species. From both a fundamental and applied point of view, these symbiotic effects would influence the ecology and evolution of parasitoids and associated population-level processes and ecosystem services (e.g. biocontrol).}, }
@article {pmid31113630, year = {2019}, author = {McLean, AH}, title = {Cascading effects of defensive endosymbionts.}, journal = {Current opinion in insect science}, volume = {32}, number = {}, pages = {42-46}, doi = {10.1016/j.cois.2018.10.003}, pmid = {31113630}, issn = {2214-5753}, mesh = {Animals ; *Food Chain ; Insecta/*microbiology/parasitology ; Plants ; *Symbiosis ; }, abstract = {Defensive endosymbionts are now understood to be widespread among insects, targeting many different threats, including predators, parasites and disease. The effects on natural enemies can be significant, resulting in dramatic changes in the outcome of interactions between insects and their attackers. Evidence is now emerging from laboratory and field work that defensive symbionts can have important effects on the surrounding insect community, as well as on vulnerable enemy species; for example, by reducing prey available for the trophic level above the enemy. However, there is a need for more experimental work across a greater taxonomic range of species in order to understand the different ways in which defensive symbionts influence insect communities.}, }
@article {pmid31109677, year = {2019}, author = {Tvedte, ES and Logsdon, JM and Forbes, AA}, title = {Sex loss in insects: causes of asexuality and consequences for genomes.}, journal = {Current opinion in insect science}, volume = {31}, number = {}, pages = {77-83}, doi = {10.1016/j.cois.2018.11.007}, pmid = {31109677}, issn = {2214-5753}, mesh = {Animals ; Female ; Hybridization, Genetic ; Insecta/*genetics/*physiology ; Male ; Parthenogenesis ; Reproduction, Asexual/*genetics ; Symbiosis ; }, abstract = {Boasting a staggering diversity of reproductive strategies, insects provide attractive models for the comparative study of the causes and consequences of transitions to asexuality. We provide an overview of some contemporary studies of reproductive systems in insects and compile an initial database of asexual insect genome resources. Insect systems have already yielded some important insights into various mechanisms by which sex is lost, including genetic, endosymbiont-mediated, and hybridization. Studies of mutation and substitution after loss of sex provide the strongest empirical support for hypothesized effects of asexuality, whereas there is mixed evidence for ecological hypotheses such as increased parasite load and altered niche breadth in asexuals. Most hypotheses have been explored in a select few taxa (e.g. stick insects, aphids), such that much of the great taxonomic breadth of insects remain understudied. Given the variation in the proximate causes of asexuality in insects, we argue for expanding the taxonomic breadth of study systems. Despite some challenges for investigating sex in insects, the increasing cost-effectiveness of genomic sequencing makes data generation for closely-related asexual and sexual lineages increasingly feasible.}, }
@article {pmid31107632, year = {2019}, author = {Forester, NT and Lane, GA and McKenzie, CM and Lamont, IL and Johnson, LJ}, title = {The Role of SreA-Mediated Iron Regulation in Maintaining Epichloë festucae-Lolium perenne Symbioses.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {32}, number = {10}, pages = {1324-1335}, doi = {10.1094/MPMI-03-19-0060-R}, pmid = {31107632}, issn = {0894-0282}, mesh = {*Epichloe/genetics ; Fungal Proteins/genetics ; *GATA Transcription Factors/genetics/metabolism ; Iron/metabolism ; *Lolium/microbiology ; Mutation ; *Symbiosis/genetics ; }, abstract = {In ascomycetes and basidiomycetes, iron-responsive GATA-type transcriptional repressors are involved in regulating iron homeostasis, notably to prevent iron toxicity through control of iron uptake. To date, it has been unknown whether this iron regulator contributes toward mutualistic endosymbiosis of microbes with plants, a system where the endophyte must function within the constraints of an in-host existence, including a dependency on the host for nutrient acquisition. Functional characterization of one such protein, SreA from Epichloë festucae, a fungal endosymbiont of cool-season grasses, indicates that regulation of iron homeostasis processes is important for symbiotic maintenance. The deletion of the sreA gene (ΔsreA) led to iron-dependent aberrant hyphal growth and the gradual loss of endophyte hyphae from perennial ryegrass. SreA negatively regulates the siderophore biosynthesis and high-affinity iron uptake systems of E. festucae, similar to other fungi, resulting in iron accumulation in mutants. Our evidence suggests that SreA is involved in the processes that moderate Epichloë iron acquisition from the plant apoplast, because overharvesting of iron in ΔsreA mutants was detected as premature chlorosis of the host using a hydroponic plant growth assay. E. festucae appears to have a tightly regulated iron management system, involving SreA that balances endophyte growth with its survival and prevents overcompetition with the host for iron in the intercellular niche, thus promoting mutualistic associations. Mutations that interfere with Epichloë iron management negatively affect iron-dependent fungal growth and destabilize mutualistic Epichloë -ryegrass associations.}, }
@article {pmid31095639, year = {2019}, author = {Hosseinzadeh, S and Ramsey, J and Mann, M and Bennett, L and Hunter, WB and Shams-Bakhsh, M and Hall, DG and Heck, M}, title = {Color morphology of Diaphorina citri influences interactions with its bacterial endosymbionts and 'Candidatus Liberibacter asiaticus'.}, journal = {PloS one}, volume = {14}, number = {5}, pages = {e0216599}, pmid = {31095639}, issn = {1932-6203}, mesh = {Animals ; Citrus/*microbiology/parasitology ; Color ; Hemiptera/*microbiology/physiology ; Hemocyanins/metabolism ; *Host-Pathogen Interactions ; Insect Vectors/*microbiology/physiology ; Plant Diseases/*microbiology ; Rhizobiaceae/isolation &amp; purification/*physiology ; *Symbiosis ; }, abstract = {Diaphorina citri is a vector of 'Candidatus Liberibacter asiaticus,' (CLas), associated with Huanglongbing, (HLB, or citrus greening) disease in citrus. D. citri exhibits three different color morph variants, blue, gray and yellow. Blue morphs have a greater capacity for long-distance flight as compared to non-blue morphs, but little else is known about how color morphology influences vector characteristics. In this study, we show that the color morphology of the insect is derived from pigmented cells of the fat body. Blue morphs acquire a lower level of CLas in their bodies from infected trees as compared to their gray and yellow conspecifics, referred to in this paper collectively as non-blue morphs. Accordingly, CLas titer in citrus leaves inoculated by non-blue insects was 6-fold higher than in leaves inoculated by blue insects. Blue color morphs harbored lower titers of Wolbachia and 'Candidatus Profftella armatura,' two of the D. citri bacterial endosymbionts. Expression of hemocyanin, a copper-binding oxygen transport protein responsible for the blue coloration of hemolymph of other arthropods and mollusks, was previously correlated with blue color morphology and is highly up-regulated in insects continuously reared on CLas infected citrus trees. Based on our results, we hypothesized that a reduction of hemocyanin expression would reduce the D. citri immune response and an increase in the titer of CLas would be observed. Surprisingly, a specific 3-fold reduction of hemocyanin-1 transcript levels using RNA silencing in blue adult D. citri morphs had an approximately 2-fold reduction on the titer of CLas. These results suggest that hemocyanin signaling from the fat body may have multiple functions in the regulation of bacterial titers in D. citri, and that hemocyanin is one of multiple psyllid genes involved in regulating CLas titer.}, }
@article {pmid31095275, year = {2019}, author = {Karimi, S and Askari Seyahooei, M and Izadi, H and Bagheri, A and Khodaygan, P}, title = {Effect of Arsenophonus Endosymbiont Elimination on Fitness of the Date Palm Hopper, Ommatissus lybicus (Hemiptera: Tropiduchidae).}, journal = {Environmental entomology}, volume = {48}, number = {3}, pages = {614-622}, doi = {10.1093/ee/nvz047}, pmid = {31095275}, issn = {1938-2936}, mesh = {Animals ; Enterobacteriaceae ; *Hemiptera ; Insecta ; *Phoeniceae ; Phylogeny ; Symbiosis ; }, abstract = {The date palm hopper, Ommatissus lybicus de Bergevin, is one of the most important pests of the date palm in the Middle East and North Africa. This insect uses its needle-like sucking mouthparts to feed on phloem, which is devoid of most essential amino acids and many vitamins. The absence of essential nutrient in its diet is suggested to be ameliorated by endosymbionts in O. lybicus. Arsenophonus is one of the main bacterial endosymbionts widely prevalent in O. lybicus. In this study, we used antibiotics to eliminate Arsenophonus from O. lybicus originating from three populations (Fin, Qale'e Qazi, and Roodan) and studied the effects on the fitness of the pest. Our results revealed that the removal of Arsenophonus increased the developmental time of the immature stages and reduced the values of different life-history parameters including nymphal survival rate and adult longevity in the host. Furthermore, elimination of Arsenophonus completely obliterated offspring production in all O. lybicus populations investigated. These results confirm the dependency of O. lybicus on Arsenophonus for fitness and give a new insight regarding the possibility of symbiotic control of O. lybicus.}, }
@article {pmid31090497, year = {2019}, author = {Jain, M and Cai, L and Fleites, LA and Munoz-Bodnar, A and Davis, MJ and Gabriel, DW}, title = {Liberibacter crescens Is a Cultured Surrogate for Functional Genomics of Uncultured Pathogenic 'Candidatus Liberibacter' spp. and Is Naturally Competent for Transformation.}, journal = {Phytopathology}, volume = {109}, number = {10}, pages = {1811-1819}, doi = {10.1094/PHYTO-04-19-0129-R}, pmid = {31090497}, issn = {0031-949X}, mesh = {*Citrus/microbiology ; *DNA Transformation Competence ; *Genome, Fungal/genetics ; Genomics ; Plant Diseases/microbiology ; *Rhizobiaceae ; *Solanum tuberosum/microbiology ; }, abstract = {'Candidatus Liberibacter' spp. are uncultured insect endosymbionts and phloem-limited bacterial plant pathogens associated with diseases ranging from severe to nearly asymptomatic. 'Ca. L. asiaticus', causal agent of Huanglongbing or citrus "greening," and 'Ca. L. solanacearum', causal agent of potato zebra chip disease, respectively threaten citrus and potato production worldwide. Research on both pathogens has been stymied by the inability to culture these agents and to reinoculate into any host. Only a single isolate of a single species of Liberibacter, Liberibacter crescens, has been axenically cultured. L. crescens strain BT-1 is genetically tractable to standard molecular manipulation techniques and has been developed as a surrogate model for functional studies of genes, regulatory elements, promoters, and secreted effectors derived from the uncultured pathogenic Liberibacters. Detailed, step-by-step, and highly reproducible protocols for axenic culture, transformation, and targeted gene knockouts of L. crescens are described. In the course of developing these protocols, we found that L. crescens is also naturally competent for direct uptake and homology-guided chromosomal integration of both linear and circular plasmid DNA. The efficiency of natural transformation was about an order of magnitude higher using circular plasmid DNA compared with linearized fragments. Natural transformation using a replicative plasmid was obtained at a rate of approximately 900 transformants per microgram of plasmid, whereas electroporation using the same plasmid resulted in 6 × 10[4] transformants. Homology-guided marker interruptions using either natural uptake or electroporation of nonreplicative plasmids yielded 10 to 12 transformation events per microgram of DNA, whereas similar interruptions using linear fragments via natural uptake yielded up to 34 transformation events per microgram of DNA.}, }
@article {pmid31088922, year = {2019}, author = {König, L and Wentrup, C and Schulz, F and Wascher, F and Escola, S and Swanson, MS and Buchrieser, C and Horn, M}, title = {Symbiont-Mediated Defense against Legionella pneumophila in Amoebae.}, journal = {mBio}, volume = {10}, number = {3}, pages = {}, pmid = {31088922}, issn = {2150-7511}, mesh = {Acanthamoeba castellanii/*microbiology/physiology ; Chlamydiales/*physiology ; Gene Expression ; Humans ; Legionella pneumophila/*pathogenicity ; *Symbiosis ; Virulence ; }, abstract = {Legionella pneumophila is an important opportunistic pathogen for which environmental reservoirs are crucial for the infection of humans. In the environment, free-living amoebae represent key hosts providing nutrients and shelter for highly efficient intracellular proliferation of L. pneumophila, which eventually leads to lysis of the protist. However, the significance of other bacterial players for L. pneumophila ecology is poorly understood. In this study, we used a ubiquitous amoeba and bacterial endosymbiont to investigate the impact of this common association on L. pneumophila infection. We demonstrate that L. pneumophila proliferation was severely suppressed in Acanthamoeba castellanii harboring the chlamydial symbiont Protochlamydia amoebophila The amoebae survived the infection and were able to resume growth. Different environmental amoeba isolates containing the symbiont were equally well protected as different L. pneumophila isolates were diminished, suggesting ecological relevance of this symbiont-mediated defense. Furthermore, protection was not mediated by impaired L. pneumophila uptake. Instead, we observed reduced virulence of L. pneumophila released from symbiont-containing amoebae. Pronounced gene expression changes in the presence of the symbiont indicate that interference with the transition to the transmissive phase impedes the L. pneumophila infection. Finally, our data show that the defensive response of amoebae harboring P. amoebophila leaves the amoebae with superior fitness reminiscent of immunological memory. Given that mutualistic associations between bacteria and amoebae are widely distributed, P. amoebophila and potentially other amoeba endosymbionts could be key in shaping environmental survival, abundance, and virulence of this important pathogen, thereby affecting the frequency of human infection.IMPORTANCE Bacterial pathogens are generally investigated in the context of disease. To prevent outbreaks, it is essential to understand their lifestyle and interactions with other microbes in their natural environment. Legionella pneumophila is an important human respiratory pathogen that survives and multiplies in biofilms or intracellularly within protists, such as amoebae. Importantly, transmission to humans occurs from these environmental sources. Legionella infection generally leads to rapid host cell lysis. It was therefore surprising to observe that amoebae, including fresh environmental isolates, were well protected during Legionella infection when the bacterial symbiont Protochlamydia amoebophila was also present. Legionella was not prevented from invading amoebae but was impeded in its ability to develop fully virulent progeny and were ultimately cleared in the presence of the symbiont. This study highlights how ecology and virulence of an important human pathogen is affected by a defensive amoeba symbiont, with possibly major consequences for public health.}, }
@article {pmid31087693, year = {2019}, author = {Hofstatter, PG and Lahr, DJG}, title = {All Eukaryotes Are Sexual, unless Proven Otherwise: Many So-Called Asexuals Present Meiotic Machinery and Might Be Able to Have Sex.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {41}, number = {6}, pages = {e1800246}, doi = {10.1002/bies.201800246}, pmid = {31087693}, issn = {1521-1878}, mesh = {Biological Evolution ; Cell Cycle Proteins/genetics ; Chromosomes/genetics ; DNA Repair/genetics ; Eukaryota/*genetics ; Heredity/genetics ; Life Cycle Stages/genetics ; Meiosis/*genetics ; Phylogeny ; Ploidies ; Recombination, Genetic ; Reproduction/genetics ; Reproduction, Asexual/genetics ; *Sex ; }, abstract = {Here a wide distribution of meiotic machinery is shown, indicating the occurrence of sexual processes in all major eukaryotic groups, without exceptions, including the putative "asexuals." Meiotic machinery has evolved from archaeal DNA repair machinery by means of ancestral gene duplications. Sex is very conserved and widespread in eukaryotes, even though its evolutionary importance is still a matter of debate. The main processes in sex are plasmogamy, followed by karyogamy and meiosis. Meiosis is fundamentally a chromosomal process, which implies recombination and ploidy reduction. Several eukaryotic lineages are proposed to be asexual because their sexual processes are never observed, but presumed asexuality correlates with lack of study. The authors stress the complete lack of meiotic proteins in nucleomorphs and their almost complete loss in the fungus Malassezia. Inversely, complete sets of meiotic proteins are present in fungal groups Glomeromycotina, Trichophyton, and Cryptococcus. Endosymbiont Perkinsela and endoparasitic Microsporidia also present meiotic proteins.}, }
@article {pmid31086829, year = {2019}, author = {Burgsdorf, I and Handley, KM and Bar-Shalom, R and Erwin, PM and Steindler, L}, title = {Life at Home and on the Roam: Genomic Adaptions Reflect the Dual Lifestyle of an Intracellular, Facultative Symbiont.}, journal = {mSystems}, volume = {4}, number = {4}, pages = {}, pmid = {31086829}, issn = {2379-5077}, abstract = {"Candidatus Synechococcus feldmannii" is a facultative intracellular symbiont of the Atlanto-Mediterranean sponge Petrosia ficiformis. Genomic information of sponge-associated cyanobacteria derives thus far from the obligate and extracellular symbiont "Candidatus Synechococcus spongiarum." Here we utilized a differential methylation-based approach for bacterial DNA enrichment combined with metagenomics to obtain the first draft genomes of "Ca. Synechococcus feldmannii." By comparative genomics, we revealed that some genomic features (e.g., iron transport mediated by siderophores, eukaryotic-like proteins, and defense mechanisms, like CRISPR-Cas [clustered regularly interspaced short palindromic repeats-associated proteins]) are unique to both symbiont types and absent or rare in the genomes of taxonomically related free-living cyanobacteria. These genomic features likely enable life under the conditions found inside the sponge host. Interestingly, there are many genomic features that are shared by "Ca. Synechococcus feldmannii" and free-living cyanobacteria, while they are absent in the obligate symbiont "Ca. Synechococcus spongiarum." These include genes related to cell surface structures, genetic regulation, and responses to environmental stress, as well as the composition of photosynthetic genes and DNA metabolism. We speculate that the presence of these genes confers on "Ca. Synechococcus feldmannii" its facultative nature (i.e., the ability to respond to a less stable environment when free-living). Our comparative analysis revealed that distinct genomic features depend on the nature of the symbiotic interaction: facultative and intracellular versus obligate and extracellular. IMPORTANCE Given the evolutionary position of sponges as one of the earliest phyla to depart from the metazoan stem lineage, studies on their distinct and exceptionally diverse microbial communities should yield a better understanding of the origin of animal-bacterium interactions. While genomes of several extracellular sponge symbionts have been published, the intracellular symbionts have, so far, been elusive. Here we compare the genomes of two unicellular cyanobacterial sponge symbionts that share an ancestor but followed different evolutionary paths-one became intracellular and the other extracellular. Counterintuitively, the intracellular cyanobacteria are facultative, while the extracellular ones are obligate. By sequencing the genomes of the intracellular cyanobacteria and comparing them to the genomes of the extracellular symbionts and related free-living cyanobacteria, we show how three different cyanobacterial lifestyles are reflected by adaptive genomic features.}, }
@article {pmid31083952, year = {2019}, author = {Fabre, B and Korona, D and Lees, JG and Lazar, I and Livneh, I and Brunet, M and Orengo, CA and Russell, S and Lilley, KS}, title = {Comparison of Drosophila melanogaster Embryo and Adult Proteome by SWATH-MS Reveals Differential Regulation of Protein Synthesis, Degradation Machinery, and Metabolism Modules.}, journal = {Journal of proteome research}, volume = {18}, number = {6}, pages = {2525-2534}, doi = {10.1021/acs.jproteome.9b00076}, pmid = {31083952}, issn = {1535-3907}, support = {BB/L002817/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Drosophila melanogaster/*genetics/growth &amp; development/metabolism/microbiology ; Embryo, Nonmammalian/metabolism/microbiology ; Gene Expression Regulation, Developmental/genetics ; Protein Biosynthesis/*genetics ; Proteolysis ; Proteome/*genetics/metabolism ; Proteomics/methods ; Transcriptome/*genetics ; Wolbachia/pathogenicity ; }, abstract = {An important area of modern biology consists of understanding the relationship between genotype and phenotype. However, to understand this relationship it is essential to investigate one of the principal links between them: the proteome. With the development of recent mass-spectrometry approaches, it is now possible to quantify entire proteomes and thus relate them to different phenotypes. Here, we present a comparison of the proteome of two extreme developmental states in the well-established model organism Drosophila melanogaster: adult and embryo. Protein modules such as ribosome, proteasome, tricarboxylic acid cycle, glycolysis, or oxidative phosphorylation were found differentially expressed between the two developmental stages. Analysis of post-translation modifications of the proteins identified in this study indicates that they generally follow the same trend as their corresponding protein. Comparison between changes in the proteome and the transcriptome highlighted patterns of post-transcriptional regulation for the subunits of protein complexes such as the ribosome and the proteasome, whereas protein from modules such as TCA cycle, glycolysis, and oxidative phosphorylation seem to be coregulated at the transcriptional level. Finally, the impact of the endosymbiont Wolbachia pipientis on the proteome of both developmental states was also investigated.}, }
@article {pmid31079194, year = {2019}, author = {Sadali, NM and Sowden, RG and Ling, Q and Jarvis, RP}, title = {Differentiation of chromoplasts and other plastids in plants.}, journal = {Plant cell reports}, volume = {38}, number = {7}, pages = {803-818}, pmid = {31079194}, issn = {1432-203X}, support = {BB/M015165/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/R009333/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/R016984/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/R005591/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Chloroplast Proteins/genetics/metabolism ; Chloroplasts/genetics/*metabolism ; Organelles/metabolism ; Plant Proteins/genetics/metabolism ; Plasmids/genetics ; Plastids/genetics/*metabolism ; Protein Transport ; }, abstract = {Plant cells are characterized by a unique group of interconvertible organelles called plastids, which are descended from prokaryotic endosymbionts. The most studied plastid type is the chloroplast, which carries out the ancestral plastid function of photosynthesis. During the course of evolution, plastid activities were increasingly integrated with cellular metabolism and functions, and plant developmental processes, and this led to the creation of new types of non-photosynthetic plastids. These include the chromoplast, a carotenoid-rich organelle typically found in flowers and fruits. Here, we provide an introduction to non-photosynthetic plastids, and then review the structures and functions of chromoplasts in detail. The role of chromoplast differentiation in fruit ripening in particular is explored, and the factors that govern plastid development are examined, including hormonal regulation, gene expression, and plastid protein import. In the latter process, nucleus-encoded preproteins must pass through two successive protein translocons in the outer and inner envelope membranes of the plastid; these are known as TOC and TIC (translocon at the outer/inner chloroplast envelope), respectively. The discovery of SP1 (suppressor of ppi1 locus1), which encodes a RING-type ubiquitin E3 ligase localized in the plastid outer envelope membrane, revealed that plastid protein import is regulated through the selective targeting of TOC complexes for degradation by the ubiquitin-proteasome system. This suggests the possibility of engineering plastid protein import in novel crop improvement strategies.}, }
@article {pmid31074963, year = {2019}, author = {Xu, Z and Fang, SM and Bakowski, MA and Rateb, ME and Yang, D and Zhu, X and Huang, Y and Zhao, LX and Jiang, Y and Duan, Y and Hull, MV and McNamara, CW and Shen, B}, title = {Discovery of Kirromycins with Anti- Wolbachia Activity from Streptomyces sp. CB00686.}, journal = {ACS chemical biology}, volume = {14}, number = {6}, pages = {1174-1182}, doi = {10.1021/acschembio.9b00086}, pmid = {31074963}, issn = {1554-8937}, mesh = {Animals ; Anti-Bacterial Agents/*chemistry/*pharmacology ; Biological Products/chemistry/pharmacology ; Drosophila/microbiology ; *Drug Discovery ; HEK293 Cells ; Humans ; Pyridones/chemistry/pharmacology ; Streptomyces/*chemistry ; Wolbachia/*drug effects ; }, abstract = {Lymphatic filariasis and onchocerciasis diseases caused by filarial parasite infections can lead to profound disability and affect millions of people worldwide. Standard mass drug administration campaigns require repetitive delivery of anthelmintics for years to temporarily block parasite transmission but do not cure infection because long-lived adult worms survive the treatment. Depletion of the endosymbiont Wolbachia, present in most filarial nematode species, results in death of adult worms and therefore represents a promising target for the treatment of filariasis. Here, we used a high-content imaging assay to screen the pure compounds collection of the natural products library at The Scripps Research Institute for anti- Wolbachia activity, leading to the identification of kirromycin B (1) as a lead candidate. Two additional congeners, kirromycin (2) and kirromycin C (3), were isolated and characterized from the same producing strain Streptomyces sp. CB00686. All three kirromycin congeners depleted Wolbachia in LDW1 Drosophila cells in vitro with half-maximal inhibitory concentrations (IC50) in nanomolar range, while doxycycline, a registered drug with anti- Wolbachia activity, showed lower activity with an IC50 of 152 ± 55 nM. Furthermore, 1-3 eliminated the Wolbachia endosymbiont in Brugia pahangi ovaries ex vivo with higher efficiency (65%-90%) at 1 μM than that of doxycycline (50%). No cytotoxicity against HEK293T and HepG2 mammalian cells was observed with 1-3 at the highest concentration (40 μM) used in the assay. These results suggest kirromycin is an effective lead scaffold, further exploration of which could potentially lead to the development of novel treatments for filarial nematode infections.}, }
@article {pmid31072343, year = {2019}, author = {Chamberlain, NB and Mehari, YT and Hayes, BJ and Roden, CM and Kidane, DT and Swehla, AJ and Lorenzana-DeWitt, MA and Farone, AL and Gunderson, JH and Berk, SG and Farone, MB}, title = {Infection and nuclear interaction in mammalian cells by 'Candidatus Berkiella cookevillensis', a novel bacterium isolated from amoebae.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {91}, pmid = {31072343}, issn = {1471-2180}, mesh = {Amoeba/*microbiology ; Cell Nucleus/*microbiology ; Cytoplasm/microbiology ; Gammaproteobacteria/*physiology/ultrastructure ; HeLa Cells ; *Host Microbial Interactions ; Humans ; Microscopy, Electron, Transmission ; Monocytes/*microbiology/ultrastructure ; Symbiosis ; THP-1 Cells ; U937 Cells ; }, abstract = {BACKGROUND: 'Candidatus Berkiella cookevillensis' and 'Ca. Berkiella aquae' have previously been described as intranuclear bacteria of amoebae. Both bacteria were isolated from amoebae and were described as appearing within the nuclei of Acanthamoeba polyphaga and ultimately lysing their host cells within 4 days. Both bacteria are Gammaproteobacteria in the order Legionellales with the greatest similarity to Coxiella burnetii. Neither bacterium grows axenically in artificial culture media. In this study, we further characterized 'Ca. B. cookevillensis' by demonstrating association with nuclei of human phagocytic and nonphagocytic cell lines.<br><br>RESULTS: Transmission electron microscopy (TEM) and confocal microscopy were used to confirm nuclear co-localization of 'Ca. B. cookevillensis' in the amoeba host A. polyphaga with 100% of cells having bacteria co-localized with host nuclei by 48&#x2009;h. TEM and confocal microscopy demonstrated that the bacterium was also observed to be closely associated with nuclei of human U937 and THP-1 differentiated macrophage cell lines and nonphagocytic HeLa human epithelial-like cells. Immunofluorescent staining revealed that the bacteria-containing vacuole invaginates the nuclear membranes and appears to cross from the cytoplasm into the nucleus as an intact vacuole.<br><br>CONCLUSION: Results of this study indicate that a novel coccoid bacterium isolated from amoebae can infect human cell lines by associating with the host cell nuclei, either by crossing the nuclear membranes or by deeply invaginating the nuclear membranes. When associated with the nuclei, the bacteria appear to be bound within a vacuole and replicate to high numbers by 48&#x2009;h. We believe this is the first report of such a process involving bacteria and human cell lines.}, }
@article {pmid31068442, year = {2019}, author = {Bakowski, MA and Shiroodi, RK and Liu, R and Olejniczak, J and Yang, B and Gagaring, K and Guo, H and White, PM and Chappell, L and Debec, A and Landmann, F and Dubben, B and Lenz, F and Struever, D and Ehrens, A and Frohberger, SJ and Sjoberg, H and Pionnier, N and Murphy, E and Archer, J and Steven, A and Chunda, VC and Fombad, FF and Chounna, PW and Njouendou, AJ and Metuge, HM and Ndzeshang, BL and Gandjui, NV and Akumtoh, DN and Kwenti, TDB and Woods, AK and Joseph, SB and Hull, MV and Xiong, W and Kuhen, KL and Taylor, MJ and Wanji, S and Turner, JD and Hübner, MP and Hoerauf, A and Chatterjee, AK and Roland, J and Tremblay, MS and Schultz, PG and Sullivan, W and Chu, XJ and Petrassi, HM and McNamara, CW}, title = {Discovery of short-course antiwolbachial quinazolines for elimination of filarial worm infections.}, journal = {Science translational medicine}, volume = {11}, number = {491}, pages = {}, doi = {10.1126/scitranslmed.aav3523}, pmid = {31068442}, issn = {1946-6242}, mesh = {Animals ; Anti-Bacterial Agents/chemistry/pharmacology/*therapeutic use ; Disease Models, Animal ; *Drug Discovery ; Female ; Filariasis/*drug therapy/*parasitology ; Filarioidea/drug effects/microbiology/*physiology ; High-Throughput Screening Assays ; Mice ; Phenotype ; Quinazolines/chemistry/pharmacology/*therapeutic use ; Small Molecule Libraries ; Wolbachia/drug effects ; }, abstract = {Parasitic filarial nematodes cause debilitating infections in people in resource-limited countries. A clinically validated approach to eliminating worms uses a 4- to 6-week course of doxycycline that targets Wolbachia, a bacterial endosymbiont required for worm viability and reproduction. However, the prolonged length of therapy and contraindication in children and pregnant women have slowed adoption of this treatment. Here, we describe discovery and optimization of quinazolines CBR417 and CBR490 that, with a single dose, achieve >99% elimination of Wolbachia in the in vivo Litomosoides sigmodontis filarial infection model. The efficacious quinazoline series was identified by pairing a primary cell-based high-content imaging screen with an orthogonal ex vivo validation assay to rapidly quantify Wolbachia elimination in Brugia pahangi filarial ovaries. We screened 300,368 small molecules in the primary assay and identified 288 potent and selective hits. Of 134 primary hits tested, only 23.9% were active in the worm-based validation assay, 8 of which contained a quinazoline heterocycle core. Medicinal chemistry optimization generated quinazolines with excellent pharmacokinetic profiles in mice. Potent antiwolbachial activity was confirmed in L. sigmodontis, Brugia malayi, and Onchocerca ochengi in vivo preclinical models of filarial disease and in vitro selectivity against Loa loa (a safety concern in endemic areas). The favorable efficacy and in vitro safety profiles of CBR490 and CBR417 further support these as clinical candidates for treatment of filarial infections.}, }
@article {pmid31056486, year = {2019}, author = {Alowaysi, M and Chen, J and Stark, S and Teague, K and LaCourse, M and Proctor, J and Vigil, K and Corrigan, J and Harding, A and Li, J and Kurtti, T and Zhong, J}, title = {Isolation and characterization of a Rickettsia from the ovary of a Western black-legged tick, Ixodes pacificus.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {4}, pages = {918-923}, pmid = {31056486}, issn = {1877-9603}, support = {R15 AI099902/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Typing Techniques ; California ; DNA, Bacterial/*genetics ; DNA, Intergenic ; Female ; Ixodes/*microbiology ; Multilocus Sequence Typing ; Ovary/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/*isolation &amp; purification ; Sequence Analysis, DNA ; }, abstract = {A rickettsial isolate was obtained from a partially engorged Ixodes pacificus female, which was collected from Humboldt County, California. The isolate was provisionally named Rickettsia endosymbiont Ixodes pacificus (REIP). The REIP isolate displayed the highest nucleotide sequence identity to Rickettsia species phylotype G021 in I. pacificus (99%, 99%, and 100% for ompA, 16S rRNA, and gltA, respectively), a bacterium that was previously identified in I. pacifiucs by PCR. Analysis of sequences from complete opening frames of five genes, 16S rRNA, gltA, ompA, ompB, and sca4, provided inference to the bacteria's classification among other Rickettsia species. The REIP isolate displayed 99.8%, 99.4%, 99.2%, 99.5%, and 99.6% nucleotide sequence identity for 16S rRNA, gltA, ompA, ompB, and sca4 gene, respectively, with genes of 'R. monacensis' str. IrR/Munich, indicating the REIP isolate is closely related to 'R. monacensis'. Our suggestion was further supported by phylogenetic analysis using concatenated sequences of 16S rRNA, gltA, ompA, ompB, and sca4 genes, concatenated sequences of dksA-xerC, mppA-purC, and rpmE-tRNA[fMet] intergenic spacer regions. Both phylogenetic trees implied that the REIP isolate is most closely related to 'R. monacensis' str. IrR/Munich. We propose the bacterium be considered as 'Rickettsia monacensis' str. Humboldt for its closest phylogenetic relative (=DSM 103975 T = ATCC TSD-94 T).}, }
@article {pmid31052498, year = {2019}, author = {Cao, LJ and Jiang, W and Hoffmann, AA}, title = {Life History Effects Linked to an Advantage for wAu Wolbachia in Drosophila.}, journal = {Insects}, volume = {10}, number = {5}, pages = {}, pmid = {31052498}, issn = {2075-4450}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; }, abstract = {Wolbachia endosymbiont infections can persist and spread in insect populations without causing apparent effects on reproduction of their insect hosts, but the mechanisms involved are largely unknown. Here, we test for fitness effects of the wAu infection of Drosophila simulans by comparing multiple infected and uninfected polymorphic isofemale lines derived from nature. We show a fitness advantage (higher offspring number) for lines with the wAu Wolbachia infection when breeding on grapes, but only where there was Talaromyces and Penicillium fungal mycelial growth. When breeding on laboratory medium, the wAu infection extended the development time and resulted in larger females with higher fecundity, life history traits, which may increase fitness. A chemical associated with the fungi (ochratoxin A) did not specifically alter the fitness of wAu-infected larvae, which developed slower and emerged with a greater weight regardless of toxin levels. These findings suggest that the fitness benefits of Wolbachia in natural populations may reflect life history changes that are advantageous under particular circumstances, such as when breeding occurs in rotting fruit covered by abundant mycelial growth.}, }
@article {pmid31037804, year = {2019}, author = {Bañuelos-Vazquez, LA and Torres Tejerizo, G and Cervantes-De La Luz, L and Girard, L and Romero, D and Brom, S}, title = {Conjugative transfer between Rhizobium etli endosymbionts inside the root nodule.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.14645}, pmid = {31037804}, issn = {1462-2920}, abstract = {Since the discovery that biological nitrogen fixation ensues in nodules resulting from the interaction of rhizobia with legumes, nodules were thought to be exclusive for hosting nitrogen-fixing and plant growth promoting bacteria. In this work, we uncover a novel function of nodules, as a niche permissive to acquisition of plasmids via conjugative transfer. We used Rhizobium etli CFN42, which nodulates Phaseolus vulgaris. The genome of R. etli CFN42 contains a chromosome and six plasmids. pRet42a is a conjugative plasmid regulated by Quorum-Sensing (QS), and pRet42d is the symbiotic plasmid. Here, using confocal microscopy and flow cytometry, we show that pRet42a transfers on the root's surface, and unexpectedly, inside the nodules. Conjugation still took place inside nodules, even when it was restricted on the plant surface by placing the QS traI regulator under the promoter of the nitrogenase gene, which is only expressed inside the nodules, or by inhibiting the QS transcriptional induction of transfer genes with a traM antiactivator on an unstable vector maintained on the plant surface and lost inside the nodules. These results conclusively confirm the occurrence of conjugation in these structures, defining them as a protected environment for bacterial diversification.}, }
@article {pmid31034469, year = {2019}, author = {Dietel, AK and Merker, H and Kaltenpoth, M and Kost, C}, title = {Selective advantages favour high genomic AT-contents in intracellular elements.}, journal = {PLoS genetics}, volume = {15}, number = {4}, pages = {e1007778}, pmid = {31034469}, issn = {1553-7404}, mesh = {*Base Composition ; Extrachromosomal Inheritance ; Gene Dosage ; *Genetic Structures ; *Genome, Bacterial ; *Genomics/methods ; Plasmids ; Selection, Genetic ; }, abstract = {Extrachromosomal genetic elements such as bacterial endosymbionts and plasmids generally exhibit AT-contents that are increased relative to their hosts' DNA. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes such as a mutational bias towards increased A+T. Here we show experimentally that an increased AT-content of host-dependent elements can be selectively favoured. Manipulating the nucleotide composition of bacterial cells by introducing A+T-rich or G+C-rich plasmids, we demonstrate that cells containing GC-rich plasmids are less fit than cells containing AT-rich plasmids. Moreover, the cost of GC-rich elements could be compensated by providing precursors of G+C, but not of A+T, thus linking the observed fitness effects to the cytoplasmic availability of nucleotides. Accordingly, introducing AT-rich and GC-rich plasmids into other bacterial species with different genomic GC-contents revealed that the costs of G+C-rich plasmids decreased with an increasing GC-content of their host's genomic DNA. Taken together, our work identifies selection as a strong evolutionary force that drives the genomes of intracellular genetic elements toward higher A+T contents.}, }
@article {pmid31031440, year = {2019}, author = {Kaushik, S and Sharma, KK and Ramani, R and Lakhanpaul, S}, title = {Detection of Wolbachia Phage (WO) in Indian Lac Insect [Kerria lacca (Kerr.)] and Its Implications.}, journal = {Indian journal of microbiology}, volume = {59}, number = {2}, pages = {237-240}, pmid = {31031440}, issn = {0046-8991}, abstract = {Wolbachia, a maternally inherited bacterium induces reproductive alterations in its hosts such as feminization of males, male killing and parthenogenesis. It is the most diverse endosymbiont infecting more than 70% of the insects ranging from pests to pollinators. Kerria lacca-a hemipteran is a sedentary, oriental insect known to produce lac-the only resin of animal origin. The present study was conducted to screen the presence of Wolbachia and its associated phages in the two infrasubspecific forms (four insect lines) of K. lacca viz. kusmi and rengeeni differing from each other on the basis of host preference. Wolbachia and its associated phage were found to be prevalent in all the insect lines analyzed. We, hereby, report the presence of WO-phage (Wolbachia phage) for the first time in K. lacca. Further, phylogenetic data differentiated the kusmi and rengeeni infrasubspecific forms into two different groups on the basis of WO-phage sequences.}, }
@article {pmid31024030, year = {2019}, author = {Wang, HL and Lei, T and Xia, WQ and Cameron, SL and Liu, YQ and Zhang, Z and Gowda, MMN and De Barro, P and Navas-Castillo, J and Omongo, CA and Delatte, H and Lee, KY and Patel, MV and Krause-Sakate, R and Ng, J and Wu, SL and Fiallo-Olivé, E and Liu, SS and Colvin, J and Wang, XW}, title = {Insight into the microbial world of Bemisia tabaci cryptic species complex and its relationships with its host.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {6568}, pmid = {31024030}, issn = {2045-2322}, mesh = {Animals ; Bacteria/classification/genetics ; Enterobacteriaceae/classification/physiology ; Hemiptera/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/physiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The 37 currently recognized Bemisia tabaci cryptic species are economically important species and contain both primary and secondary endosymbionts, but their diversity has never been mapped systematically across the group. To achieve this, PacBio sequencing of full-length bacterial 16S rRNA gene amplicons was carried out on 21 globally collected species in the B. tabaci complex, and two samples from B. afer were used here as outgroups. The microbial diversity was first explored across the major lineages of the whole group and 15 new putative bacterial sequences were observed. Extensive comparison of our results with previous endosymbiont diversity surveys which used PCR or multiplex 454 pyrosequencing platforms showed that the bacterial diversity was underestimated. To validate these new putative bacteria, one of them (Halomonas) was first confirmed to be present in MED B. tabaci using Hiseq2500 and FISH technologies. These results confirmed PacBio is a reliable and informative venue to reveal the bacterial diversity of insects. In addition, many new secondary endosymbiotic strains of Rickettsia and Arsenophonus were found, increasing the known diversity in these groups. For the previously described primary endosymbionts, one Portiera Operational Taxonomic Units (OTU) was shared by all B. tabaci species. The congruence of the B. tabaci-host and Portiera phylogenetic trees provides strong support for the hypothesis that primary endosymbionts co-speciated with their hosts. Likewise, a comparison of bacterial alpha diversities, Principal Coordinate Analysis, indistinct endosymbiotic communities harbored by different species and the co-divergence analyses suggest a lack of association between overall microbial diversity with cryptic species, further indicate that the secondary endosymbiont-mediated speciation is unlikely to have occurred in the B. tabaci species group.}, }
@article {pmid31023629, year = {2019}, author = {Tokarz, R and Tagliafierro, T and Sameroff, S and Cucura, DM and Oleynik, A and Che, X and Jain, K and Lipkin, WI}, title = {Microbiome analysis of Ixodes scapularis ticks from New York and Connecticut.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {4}, pages = {894-900}, doi = {10.1016/j.ttbdis.2019.04.011}, pmid = {31023629}, issn = {1877-9603}, mesh = {Anaplasma phagocytophilum/genetics/isolation &amp; purification ; Animals ; Babesia microti/genetics/isolation &amp; purification ; Bacteria/*genetics/isolation &amp; purification ; Borrelia/genetics/isolation &amp; purification ; Connecticut ; Encephalitis Viruses, Tick-Borne/genetics/isolation &amp; purification ; Female ; High-Throughput Nucleotide Sequencing ; Ixodes/*microbiology/parasitology/virology ; Male ; Metagenomics ; *Microbiota ; Nematoda/genetics/isolation &amp; purification ; New York ; Nymph/microbiology/parasitology/virology ; Rickettsia/genetics/isolation &amp; purification ; Viruses/*genetics/isolation &amp; purification ; }, abstract = {We employed high throughput sequencing to survey the microbiomes of Ixodes scapularis collected in New York and Connecticut. We examined 197 individual I. scapularis adults and pools from 132 adults and 197 nymphs. We detected Borrelia burgdorferi sensu stricto in 56.3% of individual ticks, Anaplasma phagocytophilum in 10.6%, Borrelia miyamotoi in 5%, Babesia microti in 7.6%, and Powassan virus in 3.6%. We did not detect Borrelia mayonii, Ehrlichia muris eauclairensis, Bartonella spp. or pathogenic Babesia species other than B. microti. The most abundant bacterium (65%), and only rickettsial species identified, was the endosymbiont Rickettsia buchneri. A filarial nematode was found in 13.7% of adult ticks. Fourteen viruses were detected including South Bay virus (22%) and blacklegged tick phlebovirus 1 and 2 (73%). This study provides insight into the microbial diversity of I. scapularis in New York State and Connecticut.}, }
@article {pmid31017531, year = {2019}, author = {Rana, VS and Popli, S and Saurav, GK and Raina, HS and Jamwal, R and Chaubey, R and Ramamurthy, VV and Natarajan, K and Rajagopal, R}, title = {Implication of the Whitefly, Bemisia tabaci, Collagen Protein in Begomoviruses Acquisition and Transmission.}, journal = {Phytopathology}, volume = {109}, number = {8}, pages = {1481-1493}, doi = {10.1094/PHYTO-03-18-0082-R}, pmid = {31017531}, issn = {0031-949X}, mesh = {Animals ; *Begomovirus/pathogenicity ; Collagen ; *Hemiptera/virology ; India ; Plant Diseases/*virology ; }, abstract = {Begomoviruses are the largest group of plant viruses transmitted exclusively by the whitefly, Bemisia tabaci (Gennadius), in a persistent, circulative, and nonpropagative manner. Begomoviruses in association with B. tabaci cause enormous loss to world agricultural crops. Transmission, retention, and circulation of begomovirus in B. tabaci are facilitated by its interaction with several proteins of the insect and its endosymbionts. However, very few such proteins have been identified from B. tabaci that are involved in this specific interaction. Here, we have performed yeast two-hybrid assay between B. tabaci complementary DNA expression library and the coat protein (CP) of tomato leaf curl New Delhi virus (ToLCNDV) and cotton leaf curl Rajasthan virus (CLCuV). Collagen was the common protein found to be interacting with both of the viruses. The collagen protein was found to be localized in gut layers of B. tabaci. Additionally, pull-down and dot-blot assays confirmed the association of endogenous collagen with ToLCNDV CP. Immunolocalization analysis also showed colocalization of ToLCNDV particles and collagen within insect gut. Finally, B. tabaci fed on anticollagen antibody and exhibited ∼46% reduction in ToLCNDV transmission, suggesting a supportive role for collagen in virus transmission.}, }
@article {pmid31014872, year = {2018}, author = {Phoosangwalthong, P and Hii, SF and Kamyingkird, K and Kengradomkij, C and Pinyopanuwat, N and Chimnoi, W and Traub, RJ and Inpankaew, T}, title = {Cats as potential mammalian reservoirs for Rickettsia sp. genotype RF2125 in Bangkok, Thailand.}, journal = {Veterinary parasitology, regional studies and reports}, volume = {13}, number = {}, pages = {188-192}, doi = {10.1016/j.vprsr.2018.07.001}, pmid = {31014872}, issn = {2405-9390}, mesh = {Animals ; Animals, Wild/microbiology ; Cat Diseases/epidemiology/microbiology ; Cats/*microbiology ; Ctenocephalides/microbiology ; Disease Reservoirs/microbiology/*veterinary ; Female ; Genotype ; Male ; Prevalence ; Public Health ; Rickettsia/*classification/isolation &amp; purification ; Rickettsia Infections/epidemiology/*veterinary ; Rickettsia felis/genetics ; Risk Factors ; Sequence Analysis, DNA ; Thailand/epidemiology ; }, abstract = {Rickettsia felis is an obligate intracellular alpha-proteobacteria and the cause of flea-borne spotted fever (FBSF), an emerging zoonosis of global public health importance, for which dogs and cats have been implicated as potential mammalian reservoirs hosts. The purpose of this study was to determine the prevalence and associated risk factors for R. felis-like species in semi-domesticated cats and their fleas in aim of understanding public health risks posed by cats and their fleas in Bangkok, Thailand. Single whole blood samples (n = 432) and where observed, fleas (n = 234), were collected from cats from 53 temple communities in Bangkok. Fleas were morphologically and genetically identified to a species level. Cat blood and fleas were subjected to a spotted fever group (SFG)-specific PCR targeting the partial outer membrane protein B (ompB). Those that were positive, were further characterised using an R. felis-specific nested PCR targeting the partial citrate synthase A (gltA) gene. All fleas were identified as Ctenocephalides felis felis. In total SFG Rickettsiae were detected in the blood of 82/482 (17.01%) cats and 3/234 fleas (1.28%). DNA sequencing of the partial ompB characterised all positive amplicons from cat blood and their fleas as 100% identical to Rickettsia endosymbiont of Ctenocephalides felis orientis isolate (Rickettsia sp. genotype RF2125) and Rickettsia asemboensis (GenBank accession no. KP256362 and KY650699, respectively). The gltA gene targeting R. felis was successfully amplified from 12/82 PCR-positive cat blood samples and these clustered with 99% bootstrap support with isolates within the Rickettsia sp. genotype RF2125 clade. Cats that were permitted to roam freely inside monasteries were more likely to be infected with R. felis compared with cats confined indoors. The results suggest that cats in Thailand are potential mammalian reservoir hosts for Rickettsia sp. genotype RF2125.}, }
@article {pmid31006611, year = {2019}, author = {Vila, A and Estrada-Peña, A and Altet, L and Cusco, A and Dandreano, S and Francino, O and Halos, L and Roura, X}, title = {Endosymbionts carried by ticks feeding on dogs in Spain.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {4}, pages = {848-852}, doi = {10.1016/j.ttbdis.2019.04.003}, pmid = {31006611}, issn = {1877-9603}, mesh = {Animals ; Bacteria/genetics/isolation &amp; purification/*pathogenicity ; DNA, Bacterial/genetics ; Dermacentor/microbiology ; Dogs/*parasitology ; Feeding Behavior ; Female ; Ixodidae/microbiology ; Male ; Polymerase Chain Reaction ; Rhipicephalus sanguineus/microbiology ; Spain ; *Symbiosis ; Tick Infestations/microbiology/*veterinary ; Tick-Borne Diseases/microbiology/*veterinary ; Ticks/*microbiology ; }, abstract = {Studies on tick microbial communities historically focused on tick-borne pathogens. However, there is an increasing interest in capturing relationships among non-pathogenic endosymbionts and exploring their relevance for tick biology. The present study included a total of 1600 adult ticks collected from domestic dogs in 4 different biogeographical regions of Spain. Each pool formed by 1 to 10 halves of individuals representing one specific ticks species was examined by PCR for the presence of Coxiellaceae, Rickettsia spp., Rickettsiales, Wolbachia spp., and other bacterial DNA. Of the pools analyzed, 92% tested positive for endosymbiont-derived DNA. Coxiella spp. endosymbionts were the most prevalent microorganisms, being always present in Rhipicephalus sanguineus sensu lato (s.l.) pools. Rickettsia spp. DNA was detected in 60% of Dermacentor reticulatus pools and 40% of R. sanguineus s.l. pools, with a higher diversity of Rickettsia species in R. sanguineus s.l. pools. Our study reveals a negative relationship of Rickettsia massiliae with the presence of tick-borne pathogens in the same pool of ticks. An additional endosymbiont, 'Candidatus Rickettsiella isopodorum', was only detected in D. reticulatus pools. Data from this study indicate that dogs in Spain are exposed to several endosymbionts. Due to the importance of tick-borne pathogens, characterizing the role of endosymbionts for tick physiology and prevalence, may lead to novel control strategies.}, }
@article {pmid31001206, year = {2019}, author = {Chiellini, C and Pasqualetti, C and Lanzoni, O and Fagorzi, C and Bazzocchi, C and Fani, R and Petroni, G and Modeo, L}, title = {Harmful Effect of Rheinheimera sp. EpRS3 (Gammaproteobacteria) Against the Protist Euplotes aediculatus (Ciliophora, Spirotrichea): Insights Into the Ecological Role of Antimicrobial Compounds From Environmental Bacterial Strains.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {510}, pmid = {31001206}, issn = {1664-302X}, abstract = {Rheinheimera sp. strain EpRS3, isolated from the rhizosphere of Echinacea purpurea, is already known for its ability to produce antibacterial compounds. By use of culture experiments, we verified and demonstrated its harmful effect against the ciliated protist Euplotes aediculatus (strain EASCc1), which by FISH experiments resulted to harbor in its cytoplasm the obligate bacterial endosymbiont Polynucleobacter necessarius (Betaproteobacteria) and the secondary endosymbiont "Candidatus Nebulobacter yamunensis" (Gammaproteobacteria). In culture experiments, the number of ciliates treated both with liquid broth bacteria-free (Supernatant treatment) and bacteria plus medium (Tq treatment), decreases with respect to control cells, with complete disappearance of ciliates within 6 h after Tq treatment. Results suggest that Rheinheimera sp. EpRS3 produces and releases in liquid culture one or more bioactive molecules affecting E. aediculatus survival. TEM analysis of control (not treated) ciliates allowed to morphologically characterize both kind of E. aediculatus endosymbionts. In treated ciliates, collected soon after the arising of cell suffering leading to death, TEM observations revealed some ultrastructural damages, indicating that P. necessarius endosymbionts went into degradation and vacuolization after both Supernatant and Tq treatments. Additionally, TEM investigation showed that when the ciliate culture was inoculated with Tq treatment, both a notable decrease of P. necessarius number and an increase of damaged and degraded mitochondria occur. FISH experiments performed on treated ciliates confirmed TEM results and, by means of the specific probe herein designed, disclosed the presence of Rheinheimera sp. EpRS3 both inside phagosomes and free in cytoplasm in ciliates after Tq treatment. This finding suggests a putative ability of Rheinheimera sp. EpRS3 to reintroduce itself in the environment avoiding ciliate digestion.}, }
@article {pmid30999960, year = {2019}, author = {Sabūnas, V and Radzijevskaja, J and Sakalauskas, P and Petkevičius, S and Karvelienė, B and Žiliukienė, J and Lipatova, I and Paulauskas, A}, title = {Dirofilaria repens in dogs and humans in Lithuania.}, journal = {Parasites &amp; vectors}, volume = {12}, number = {1}, pages = {177}, pmid = {30999960}, issn = {1756-3305}, mesh = {Adult ; Aged ; Animals ; Child ; *Dirofilaria repens/microbiology ; Dirofilariasis/epidemiology/*parasitology ; Dog Diseases/epidemiology/*parasitology ; Dogs ; Eye Diseases/parasitology ; Female ; Humans ; Lithuania/epidemiology ; Male ; Middle Aged ; Phylogeny ; Polymerase Chain Reaction ; Prevalence ; Symbiosis ; Wolbachia/isolation &amp; purification ; }, abstract = {BACKGROUND: In Lithuania, the first case of canine subcutaneous dirofilariosis was recorded in 2010. Since then, an increasing number of cases of canine dirofilariosis have been documented in different veterinary clinics throughout the country. Human dirofilariosis was diagnosed in Lithuania for the first time in September 2011. However, to the authors' knowledge, there are no published data on the presence and prevalence of autochthonous dirofilariosis in dogs and humans in the country. The present study provides information about the predominant species and prevalence of Dirofilaria in dogs and describes the cases of human dirofilariosis in Lithuania. It also outlines PCR detection of the bacterial endosymbiont Wolbachia that contributes to the inflammatory features of filarioid infection.<br><br>RESULTS: A total of 2280 blood samples and six adult worms from pet and shelter dogs were collected in the central and eastern regions of Lithuania in 2013-2015. Based on their morphological appearance, morphometric measurements and molecular analysis, all the adult nematodes were identified as Dirofilaria repens. The diagnosis of microfilariae in blood samples was based on blood smear analysis and Knott's test. The PCR and sequence analysis of the ribosomal DNA ITS2 region and cox1 gene confirmed the presence of D. repens. Overall, 61 (2.7%) of the 2280 blood samples were found to be positive for the presence of D. repens. The infection rate of D. repens was significantly higher in shelter dogs (19.0%; 19/100) than in pet dogs (1.9%; 42/2180) (&#x3c7;[2]&#x2009;=&#x2009;100.039, df&#x2009;=&#x2009;1, P&#x2009;<&#x2009;0.0001). Forty-nine DNA samples of D. repens-infected dogs were tested for the presence of the bacterial endosymbiont Wolbachia and, of these, 40 samples (81.6%) were found to be positive. Three ocular and six subcutaneous cases of human dirofilariosis were diagnosed in Lithuania in the period 2011-2018.<br><br>CONCLUSIONS: To the authors' knowledge, this is the first report of autochthonous D. repens infection in dogs and humans in Lithuania. The present data demonstrate that D. repens is the main etiological agent of dirofilariosis in Lithuania. The DNA of the filarioid endosymbiotic bacterium Wolbachia was detected in the vast majority of dogs infected with D. repens.}, }
@article {pmid30992179, year = {2019}, author = {Muñoz-Leal, S and Macedo, C and Gonçalves, TC and Dias Barreira, J and Labruna, MB and de Lemos, ERS and Ogrzewalska, M}, title = {Detected microorganisms and new geographic records of Ornithodoros rietcorreai (Acari: Argasidae) from northern Brazil.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {4}, pages = {853-861}, doi = {10.1016/j.ttbdis.2019.04.004}, pmid = {30992179}, issn = {1877-9603}, mesh = {Anaplasmataceae/genetics/isolation &amp; purification ; Animals ; Babesia/genetics/isolation &amp; purification ; Bacteria/*genetics/isolation &amp; purification ; Borrelia/genetics/isolation &amp; purification ; Brazil ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Protozoan/genetics/isolation &amp; purification ; Female ; Geography ; Larva/microbiology ; Male ; Nymph/microbiology ; Ornithodoros/*microbiology/*parasitology ; *Phylogeny ; Rickettsia/genetics/isolation &amp; purification ; }, abstract = {Reliable data on distributional ranges of soft ticks (Argasidae) and assessments of putative tick-borne agents enhance the understanding on tick-associated microorganisms. A total of 96 ticks morphologicaly and molecularly identified as Ornithodoros rietcorreai were collected in Tocantins State, Brazil, using Noireau traps with living bait as CO2 source. Ninety-six ticks (54 nymphs, 32 males, 10 females) with different engorgement degrees were collected. Fourty-seven (48.9%) of them were individually screened by PCR for detecting bacteria of Anaplasmataceae family and genera Rickettsia, and Borrelia. The presence of protozoans of the genus Babesia was assessed as well. Fourty seven ticks were submitted to analysis. Nine ticks (19.1%) yielded sequences for gltA and htrA genes most identical with a series of endosymbiont rickettsiae and Rickettsia bellii, respectively. Upon two ticks (4.2%) we retrieved DNA of a potential new Wolbachia sp., and DNA of a putative novel Hepatozoon was characterized from three (6.4%) specimens. No DNA of Babesia or Borrelia was detected. Remarkably, amplicons of unidentified eukaryotic organisms, most closely related with apicomplexans but also with dinoflagellates (91% of identity after BLAST analyses), were recovered from two ticks (4.2%) using primers designed for Babesia 18S rRNA gene. Our records expand the distribution of O. rietcorreai into Brazilian Cerrado biome and introduce the occurrence of microorganisms in this tick species.}, }
@article {pmid30991952, year = {2019}, author = {Dhaygude, K and Nair, A and Johansson, H and Wurm, Y and Sundström, L}, title = {The first draft genomes of the ant Formica exsecta, and its Wolbachia endosymbiont reveal extensive gene transfer from endosymbiont to host.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {301}, pmid = {30991952}, issn = {1471-2164}, support = {BB/K004204/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Ants/*genetics/*microbiology ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genes, Insect/genetics ; *Genomics ; Symbiosis/*genetics ; Wolbachia/*genetics/*physiology ; }, abstract = {BACKGROUND: Adapting to changes in the environment is the foundation of species survival, and is usually thought to be a gradual process. However, transposable elements (TEs), epigenetic modifications, and/or genetic material acquired from other organisms by means of horizontal gene transfer (HGTs), can also lead to novel adaptive traits. Social insects form dense societies, which attract and maintain extra- and intracellular accessory inhabitants, which may facilitate gene transfer between species. The wood ant Formica exsecta (Formicidae; Hymenoptera), is a common ant species throughout the Palearctic region. The species is a well-established model for studies of ecological characteristics and evolutionary conflict.<br><br>RESULTS: In this study, we sequenced and assembled draft genomes for F. exsecta and its endosymbiont Wolbachia. The F. exsecta draft genome is 277.7&#x2009;Mb long; we identify 13,767 protein coding genes, for which we provide gene ontology and protein domain annotations. This is also the first report of a Wolbachia genome from ants, and provides insights into the phylogenetic position of this endosymbiont. We also identified multiple horizontal gene transfer events (HGTs) from Wolbachia to F. exsecta. Some of these HGTs have also occurred in parallel in multiple other insect genomes, highlighting the extent of HGTs in eukaryotes.<br><br>CONCLUSION: We present the first draft genome of ant F. exsecta, and its endosymbiont Wolbachia (wFex), and show considerable rates of gene transfer from the symbiont to the host. We expect that especially the F. exsecta genome will be valuable resource in further exploration of the molecular basis of the evolution of social organization.}, }
@article {pmid30990223, year = {2019}, author = {Mathé-Hubert, H and Kaech, H and Ganesanandamoorthy, P and Vorburger, C}, title = {Evolutionary costs and benefits of infection with diverse strains of Spiroplasma in pea aphids.}, journal = {Evolution; international journal of organic evolution}, volume = {73}, number = {7}, pages = {1466-1481}, doi = {10.1111/evo.13740}, pmid = {30990223}, issn = {1558-5646}, support = {CRSII3_154396//Schweizerischer Nationalfonds zur F&#xf6;rderung der Wissenschaftlichen Forschung/International ; }, mesh = {Animals ; Aphids/*microbiology/*parasitology ; *Biological Evolution ; Cost-Benefit Analysis ; Spiroplasma/genetics/*physiology ; *Symbiosis ; Wasps/*physiology ; }, abstract = {The heritable endosymbiont Spiroplasma infects many insects and has repeatedly evolved the ability to protect its hosts against different parasites. Defenses do not come for free to the host, and theory predicts that more costly symbionts need to provide stronger benefits to persist in host populations. We investigated the costs and benefits of Spiroplasma infections in pea aphids (Acyrthosiphon pisum), testing 12 bacterial strains from three different clades. Virtually all strains decreased aphid lifespan and reproduction, but only two had a (weak) protective effect against the parasitoid Aphidius ervi, an important natural enemy of pea aphids. Spiroplasma-induced fitness costs were variable, with strains from the most slowly evolving clade reaching higher titers and curtailing aphid lifespan more strongly than other strains. Some Spiroplasma strains shared their host with a second endosymbiont, Regiella insecticola. Although the result of an unfortunate handling error, these co-infections proved instructive, because they showed that the cost of infection with Spiroplasma may be attenuated in the presence of Regiella. These results suggest that mechanisms other than protection against A. ervi maintain pea aphid infections with diverse strains of Spiroplasma, and that studying them in isolation will not provide a complete picture of their effects on host fitness.}, }
@article {pmid30989224, year = {2019}, author = {Chong, RA and Park, H and Moran, NA}, title = {Genome Evolution of the Obligate Endosymbiont Buchnera aphidicola.}, journal = {Molecular biology and evolution}, volume = {36}, number = {7}, pages = {1481-1489}, doi = {10.1093/molbev/msz082}, pmid = {30989224}, issn = {1537-1719}, mesh = {Animals ; Aphids/microbiology ; Buchnera/*genetics ; *Evolution, Molecular ; Gene Rearrangement ; Genetic Variation ; *Genome, Bacterial ; Phylogeny ; *Selection, Genetic ; Symbiosis ; }, abstract = {An evolutionary consequence of uniparentally transmitted symbiosis is degradation of symbiont genomes. We use the system of aphids and their maternally inherited obligate endosymbiont, Buchnera aphidicola, to explore the evolutionary process of genome degradation. We compared complete genome sequences for 39 Buchnera strains, including 23 newly sequenced symbiont genomes from diverse aphid hosts. We reconstructed the genome of the most recent shared Buchnera ancestor, which contained 616 protein-coding genes, and 39 RNA genes. The extent of subsequent gene loss varied across lineages, resulting in modern genomes ranging from 412 to 646 kb and containing 354-587 protein-coding genes. Loss events were highly nonrandom across loci. Genes involved in replication, transcription, translation, and amino acid biosynthesis are largely retained, whereas genes underlying ornithine biosynthesis, stress responses, and transcriptional regulation were lost repeatedly. Aside from losses, gene order is almost completely stable. The main exceptions involve movement between plasmid and chromosome locations of genes underlying tryptophan and leucine biosynthesis and supporting nutrition of aphid hosts. This set of complete genomes enabled tests for signatures of positive diversifying selection. Of 371 Buchnera genes tested, 29 genes show strong support for ongoing positive selection. These include genes encoding outer membrane porins that are expected to be involved in direct interactions with hosts. Collectively, these results indicate that extensive genome reduction occurred in the ancestral Buchnera prior to aphid diversification and that reduction has continued since, with losses greater in some lineages and for some loci.}, }
@article {pmid30984153, year = {2019}, author = {Buckley, A and MacGregor, B and Teske, A}, title = {Identification, Expression and Activity of Candidate Nitrite Reductases From Orange Beggiatoaceae, Guaymas Basin.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {644}, pmid = {30984153}, issn = {1664-302X}, abstract = {Orange filamentous Beggiatoaceae form massive microbial mats on hydrothermal sediments in Guaymas Basin; these bacteria are considered to oxidize sulfide with nitrate and nitrite as electron acceptors. From a previously analyzed genome of an orange Beggiatoaceae filament, three candidate genes for enzymes with nitrite-reducing function - an orange octaheme cytochrome, a nirS nitrite reductase, and a nitrite/tetrathionate-reducing octaheme cytochrome - were cloned and expressed in Escherichia coli. The expressed and purified orange cytochrome showed reduced nitrite-reducing activity compared to the multifunctional native protein obtained from microbial mats. The nirS gene product showed in vitro but no in-gel nitrite-reducing activity; and the nitrite/tetrathionate-reducing octaheme cytochrome was capable of reducing both nitrite and tetrathionate in vitro. Phylogenetic analysis shows that the orange Beggiatoaceae nirS, in contrast to the other candidate nitrite reductases, does not form monophyletic lineages with its counterparts in other large sulfur-oxidizing bacteria, and most likely represents a recent acquisition by lateral gene transfer. The nitrite/tetrathionate-reducing enzyme of the orange Beggiatoaceae is related to nitrite- and tetrathionate reductases harbored predominantly by Gammaproteobacteria, including obligate endosymbionts of hydrothermal vent tubeworms. Thus, the orange Guaymas Basin Beggiatoaceae have a repertoire of at least three different functional enzymes for nitrite reduction. By demonstrating the unusual diversity of enzymes with a potential role in nitrite reduction, we show that bacteria in highly dynamic, sulfide-rich hydrothermal vent habitats adapt to these conditions that usually prohibit nitrate and nitrite reduction. In the case of the orange Guaymas Beggiatoaceae, classical denitrification appears to be replaced by different multifunctional enzymes for nitrite and tetrathionate reduction; the resulting ecophysiological flexibility provides a new key to the dominance of these Beggiatoaceae in hydrothermal hot spots.}, }
@article {pmid30963950, year = {2019}, author = {Uchiumi, Y and Ohtsuki, H and Sasaki, A}, title = {Evolution of self-limited cell division of symbionts.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1895}, pages = {20182238}, pmid = {30963950}, issn = {1471-2954}, mesh = {*Biological Coevolution ; Cell Division/*physiology ; Models, Biological ; Symbiosis/*physiology ; }, abstract = {In mutualism between unicellular hosts and their endosymbionts, symbiont's cell division is often synchronized with its host's, ensuring the permanent relationship between endosymbionts and their hosts. The evolution of synchronized cell division thus has been considered to be an essential step in the evolutionary transition from symbionts to organelles. However, if symbionts would accelerate their cell division without regard for the synchronization with the host, they would proliferate more efficiently. Thus, it is paradoxical that symbionts evolve to limit their own division for synchronized cell division. Here, we theoretically explore the condition for the evolution of self-limited cell division of symbionts, by assuming that symbionts control their division rate and that hosts control symbionts' death rate by intracellular digestion and nutrient supply. Our analysis shows that symbionts can evolve to limit their own cell division. Such evolution occurs if not only symbiont's but also host's benefit through symbiosis is large. Moreover, the coevolution of hosts and symbionts leads to either permanent symbiosis where symbionts proliferate to keep pace with their host, or the arms race between symbionts that behave as lytic parasites and hosts that resist them by rapid digestion.}, }
@article {pmid30963947, year = {2019}, author = {Evangelista, DA and Wipfler, B and Béthoux, O and Donath, A and Fujita, M and Kohli, MK and Legendre, F and Liu, S and Machida, R and Misof, B and Peters, RS and Podsiadlowski, L and Rust, J and Schuette, K and Tollenaar, W and Ware, JL and Wappler, T and Zhou, X and Meusemann, K and Simon, S}, title = {An integrative phylogenomic approach illuminates the evolutionary history of cockroaches and termites (Blattodea).}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1895}, pages = {20182076}, pmid = {30963947}, issn = {1471-2954}, mesh = {Animals ; Biological Evolution ; Cockroaches/*classification/genetics ; Isoptera/*classification/genetics ; *Phylogeny ; }, abstract = {Phylogenetic relationships among subgroups of cockroaches and termites are still matters of debate. Their divergence times and major phenotypic transitions during evolution are also not yet settled. We addressed these points by combining the first nuclear phylogenomic study of termites and cockroaches with a thorough approach to divergence time analysis, identification of endosymbionts, and reconstruction of ancestral morphological traits and behaviour. Analyses of the phylogenetic relationships within Blattodea robustly confirm previously uncertain hypotheses such as the sister-group relationship between Blaberoidea and remaining Blattodea, and Lamproblatta being the closest relative to the social and wood-feeding Cryptocercus and termites. Consequently, we propose new names for various clades in Blattodea: Cryptocercus + termites = Tutricablattae; Lamproblattidae + Tutricablattae = Kittrickea; and Blattoidea + Corydioidea = Solumblattodea. Our inferred divergence times contradict previous studies by showing that most subgroups of Blattodea evolved in the Cretaceous, reducing the gap between molecular estimates of divergence times and the fossil record. On a phenotypic level, the blattodean ground-plan is for egg packages to be laid directly in a hole while other forms of oviposition, including ovovivipary and vivipary, arose later. Finally, other changes in egg care strategy may have allowed for the adaptation of nest building and other novelties.}, }
@article {pmid30963934, year = {2019}, author = {Taubner, I and Hu, MY and Eisenhauer, A and Bleich, M}, title = {Electrophysiological evidence for light-activated cation transport in calcifying corals.}, journal = {Proceedings. Biological sciences}, volume = {286}, number = {1896}, pages = {20182444}, pmid = {30963934}, issn = {1471-2954}, mesh = {Animals ; Anthozoa/growth &amp; development/metabolism/*radiation effects ; Calcification, Physiologic ; Cations/*metabolism/radiation effects ; Electrophysiological Phenomena ; Ion Transport/*radiation effects ; *Light ; }, abstract = {Light has been demonstrated to enhance calcification rates in hermatypic coral species. To date, it remains unresolved whether calcifying epithelia change their ion transport activity during illumination, and whether such a process is mediated by the endosymbiotic algae or can be controlled by the coral host itself. Using a modified Ussing chamber in combination with H[+] sensitive microelectrode measurements, the present work demonstrates that light triggers the generation of a skeleton positive potential of up to 0.9 mV in the hermatypic coral Stylophora pistillata. This potential is generated by a net flux of cations towards the skeleton and reaches its maximum at blue (450 nm) light. The effects of pharmacological inhibitors targeting photosynthesis 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) and anion transport 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) were investigated by pH microelectrode measurements in coral tissues demonstrating a rapid decrease in tissue pH under illumination. However, these inhibitors showed no effect on the electrophysiological light response of the coral host. By contrast, metabolic inhibition by cyanide and deoxyglucose reversibly inhibited the light-induced cation flux towards the skeleton. These results suggest that ion transport across coral epithelia is directly triggered by blue light, independent of photosynthetic activity of algal endosymbionts. Measurements of this very specific and quantifiable physiological response can provide parameters to identify photoreception mechanisms and will help to broaden our understanding of the mechanistic link between light stimulation and epithelial ion transport, potentially relevant for calcification in hermatypic corals.}, }
@article {pmid30963267, year = {2019}, author = {Boevé, JL and Rozenberg, R}, title = {Berberis sawfly contains toxic peptides not only at larval stage.}, journal = {Die Naturwissenschaften}, volume = {106}, number = {5-6}, pages = {14}, pmid = {30963267}, issn = {1432-1904}, mesh = {Animals ; Chromatography, Liquid ; Feces/chemistry ; Hymenoptera/*chemistry ; Larva/chemistry ; Oligopeptides/analysis ; Peptides/*analysis ; Pupa/chemistry ; Tandem Mass Spectrometry ; Toxins, Biological/*analysis ; }, abstract = {Livestock can die from grazing in areas where larvae of certain Argidae or Pergidae species containing toxic peptides occur in mass. However, it remains unknown whether other stages also contain these compounds. Here, single specimens of larvae, prepupae, and adults of Arge berberidis, plus samples of its cocoons and larval feces, were analyzed by liquid chromatography-tandem mass spectrometry. The four peptides, pergidin (Perg), 4-valinepergidin (VPerg), dephosphorylated pergidin (dpPerg), and lophyrotomin (LGln), were detected in each of the three stages. Peptide concentrations, in percentage fresh weight, increased from larval up to adult stages, with mean values from 0.044 to 0.125% for Perg, 0.008 to 0.023% for VPerg, and 0.064 to 0.116% for LGln, whereas dpPerg never exceeded 0.001%. The concentrations of this latter peptide averaged 0.002% in the cocoon built by the prepupa, and nearly no peptides were detected in larval feces. Moreover, the concentrations of the three main peptides (Perg, LGln, and VPerg) tended to be correlated with each other in larvae and especially in adults. It is likely that peptide production, purportedly by an endosymbiont, stops at prepupal stage and that concentration of the peptides increases from prepupa to adult due to a decrease of body weight.}, }
@article {pmid30962510, year = {2019}, author = {Gallo-Franco, JJ and Duque-Gamboa, DN and Toro-Perea, N}, title = {Bacterial communities of Aphis gossypii and Myzus persicae (Hemiptera: Aphididae) from pepper crops (Capsicum sp.).}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {5766}, pmid = {30962510}, issn = {2045-2322}, mesh = {Animals ; Aphids/*microbiology/pathogenicity ; Bacteria/classification/genetics ; Capsicum/parasitology ; *Host Specificity ; *Microbiota ; Phylogeny ; }, abstract = {Insects harbor a wide variety of microorganisms that form complex and changing communities and play an important role in the biology and evolution of their hosts. Aphids have been used as model organisms to study microorganism-insect interactions. Almost all aphids are infected with the obligate endosymbiont Buchnera aphidicola and can host different bacteria that allow them to acquire traits of agronomic importance, such as resistance to high temperatures and/or defense against natural enemies. However, the bacterial communities of most aphid species remain poorly characterized. In this study, we used high-throughput DNA sequencing to characterize the bacterial communities of Aphis gossypii and Myzus persicae from two cultivable pepper species, Capsicum frutescens (Tabasco variety) and C. annuum (Cayenne variety), in four localities of southwestern Colombia. In addition, we evaluated the dynamics of A. gossypii-associated microorganisms on a seasonal basis. Our results show that the bacterial communities of A. gossypii and M. persicae are dominated by the primary endosymbiont B. aphidicola, while the presence of the facultative symbiont Arsenophonus sp. was only detected in one A. gossypii population from cayenne pepper. In addition to these two known symbionts, eight bacterial OTUs were identified that presented a frequency of 1% or more in at least one of the analyzed populations. The results show that the bacterial communities of aphids associated with pepper crops appears to be structured according to the host aphid species and the geographical location, while no differences were observed in the diversity of bacteria between host plants. Finally, the diversity and abundance of the A. gossypii bacterial community was variable among the four sampling points evaluated over the year and showed a relation with the aphid's population dynamics. This study represents the first approach to the knowledge of the bacterial community present in chili pepper aphids from Colombia. Nevertheless, more in-depth studies, including replicates, are required to confirm the patterns observed in the microbial communities of aphids from pepper crops.}, }
@article {pmid30962361, year = {2019}, author = {Jäckle, O and Seah, BKB and Tietjen, M and Leisch, N and Liebeke, M and Kleiner, M and Berg, JS and Gruber-Vodicka, HR}, title = {Chemosynthetic symbiont with a drastically reduced genome serves as primary energy storage in the marine flatworm Paracatenula.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {17}, pages = {8505-8514}, pmid = {30962361}, issn = {1091-6490}, mesh = {Animals ; Chemoautotrophic Growth/genetics/physiology ; Genome, Bacterial/*genetics ; Metabolic Networks and Pathways ; *Platyhelminths/metabolism/microbiology/physiology ; *Rhodospirillaceae/genetics/physiology ; *Symbiosis/genetics/physiology ; }, abstract = {Hosts of chemoautotrophic bacteria typically have much higher biomass than their symbionts and consume symbiont cells for nutrition. In contrast to this, chemoautotrophic Candidatus Riegeria symbionts in mouthless Paracatenula flatworms comprise up to half of the biomass of the consortium. Each species of Paracatenula harbors a specific Ca Riegeria, and the endosymbionts have been vertically transmitted for at least 500 million years. Such prolonged strict vertical transmission leads to streamlining of symbiont genomes, and the retained physiological capacities reveal the functions the symbionts provide to their hosts. Here, we studied a species of Paracatenula from Sant'Andrea, Elba, Italy, using genomics, gene expression, imaging analyses, as well as targeted and untargeted MS. We show that its symbiont, Ca R. santandreae has a drastically smaller genome (1.34 Mb) than the symbiont´s free-living relatives (4.29-4.97 Mb) but retains a versatile and energy-efficient metabolism. It encodes and expresses a complete intermediary carbon metabolism and enhanced carbon fixation through anaplerosis and accumulates massive intracellular inclusions such as sulfur, polyhydroxyalkanoates, and carbohydrates. Compared with symbiotic and free-living chemoautotrophs, Ca R. santandreae's versatility in energy storage is unparalleled in chemoautotrophs with such compact genomes. Transmission EM as well as host and symbiont expression data suggest that Ca R. santandreae largely provisions its host via outer-membrane vesicle secretion. With its high share of biomass in the symbiosis and large standing stocks of carbon and energy reserves, it has a unique role for bacterial symbionts-serving as the primary energy storage for its animal host.}, }
@article {pmid30953568, year = {2019}, author = {Chen, W and Shakir, S and Bigham, M and Richter, A and Fei, Z and Jander, G}, title = {Genome sequence of the corn leaf aphid (Rhopalosiphum maidis Fitch).}, journal = {GigaScience}, volume = {8}, number = {4}, pages = {}, pmid = {30953568}, issn = {2047-217X}, mesh = {Animals ; Aphids/classification/drug effects/*genetics/metabolism ; Computational Biology/methods ; Gene Expression Profiling ; Gene Transfer, Horizontal ; *Genome ; *Genomics/methods ; Inactivation, Metabolic ; Insecticide Resistance ; Molecular Sequence Annotation ; Phylogeny ; Sequence Analysis, DNA ; Transcriptome ; }, abstract = {BACKGROUND: The corn leaf aphid (Rhopalosiphum maidis Fitch) is the most economically damaging aphid pest on maize (Zea mays), one of the world's most important grain crops. In addition to causing direct damage by removing photoassimilates, R. maidis transmits several destructive maize viruses, including maize yellow dwarf virus, barley yellow dwarf virus, sugarcane mosaic virus, and cucumber mosaic virus.<br><br>FINDINGS: The genome of a parthenogenetically reproducing R. maidis clone was assembled with a combination of Pacific Biosciences (207-fold coverage) and Illumina (83-fold coverage) sequencing. The 689 assembled contigs, which have an N50 size of 9.0 megabases (Mb) and a low level of heterozygosity, were clustered using Phase Genomics Hi-C interaction maps. Consistent with the commonly observed 2n = 8 karyotype of R. maidis, most of the contigs (473 spanning 321 Mb) were successfully oriented into 4 scaffolds. The genome assembly captured the full length of 95.8% of the core eukaryotic genes, indicating that it is highly complete. Repetitive sequences accounted for 21.2% of the assembly, and a total of 17,629 protein-coding genes were predicted with integrated evidence from ab initio and homology-based gene predictions and transcriptome sequences generated with both Pacific Biosciences and Illumina. An analysis of likely horizontally transferred genes identified 2 from bacteria, 7 from fungi, 2 from protozoa, and 9 from algae. Repeat elements, transposons, and genes encoding likely detoxification enzymes (cytochrome P450s, glutathione S-transferases, carboxylesterases, uridine diphosphate-glucosyltransferases, and ABC transporters) were identified in the genome sequence. Other than Buchnera aphidicola (642,929 base pairs, 602 genes), no endosymbiont bacteria were found in R. maidis.<br><br>CONCLUSIONS: A high-quality R. maidis genome was assembled at the chromosome level. This genome sequence will enable further research related to ecological interactions, virus transmission, pesticide resistance, and other aspects of R. maidis biology. It also serves as a valuable resource for comparative investigation of other aphid species.}, }
@article {pmid30953430, year = {2019}, author = {Landmann, F}, title = {The Wolbachia Endosymbionts.}, journal = {Microbiology spectrum}, volume = {7}, number = {2}, pages = {}, doi = {10.1128/microbiolspec.BAI-0018-2019}, pmid = {30953430}, issn = {2165-0497}, mesh = {Animals ; Arthropods/microbiology ; Filarioidea/microbiology ; Host Microbial Interactions/*physiology ; Insecta/microbiology ; Symbiosis ; Wolbachia/classification/genetics/pathogenicity/*physiology ; }, abstract = {The Wolbachia endosymbionts encompass a large group of intracellular bacteria of biomedical and veterinary relevance, closely related to Anaplasma, Ehrlichia, and Rickettsia. This genus of Gram-negative members of the Alphaproteobacteria does not infect vertebrates but is instead restricted to ecdysozoan species, including terrestrial arthropods and a family of parasitic filarial nematodes, the Onchocercidae. The Wolbachia profoundly impact not only the ecology and evolution but also the reproductive biology of their hosts, through a wide range of symbiotic interactions. Because they are essential to the survival and reproduction of their filarial nematode hosts, they represent an attractive target to fight filariasis. Their abilities to spread through insect populations and to affect vector competence through pathogen protection have made Wolbachia a staple for controlling vector-borne diseases. Estimated to be present in up to 66% of insect species, the Wolbachia are probably the most abundant endosymbionts on earth. Their success resides in their unique capacity to infect and manipulate the host germ line to favor their vertical transmission through the maternal lineage. Because the Wolbachia resist genetic manipulation and growth in axenic culture, our understanding of their biology is still in its infancy. Despite these limitations, the "-omics" revolution combined with the use of well-established and emerging experimental host models is accelerating our comprehension of the host phenotypes caused by Wolbachia, and the identification of Wolbachia effectors is ongoing.}, }
@article {pmid30952366, year = {2019}, author = {Gosavi, SM and Verma, CR and Kharat, SS and Pise, M and Kumkar, P}, title = {Structural adequacy of the digestive tract supports dual feeding habit in catfish Pachypterus khavalchor (Siluriformes: Horabagridae).}, journal = {Acta histochemica}, volume = {121}, number = {4}, pages = {437-449}, doi = {10.1016/j.acthis.2019.03.006}, pmid = {30952366}, issn = {1618-0372}, mesh = {Animals ; Catfishes/*anatomy &amp; histology/metabolism/*physiology ; Chitin/metabolism ; Feeding Behavior/*physiology ; Female ; Gastric Mucins/metabolism ; Gastrointestinal Tract/*anatomy &amp; histology/*physiology ; Goblet Cells/cytology/physiology ; Male ; }, abstract = {Lepidophagy is comparatively rare amongst teleost fishes, yet our understanding of this specialization is lacking. Therefore we examined the digestive tract features of Pachypterus khavalchor using morphological, osteological, histological and histochemical techniques to comprehend and relate structural organization of digestive tract with scale eating habit. Morphologically, the alimentary canal is defined by a short and muscular esophagus, well-developed stomach and comparatively short intestine. Gut content analysis and intestinal coefficient value (0.53 ± 0.01) revealed that P. khavalchor exhibit both carnivory and lepidophagy. However, P. khavalchor primarily feeds on the scales (67.47%) and other chitin-rich material like aquatic insects (17.62%), aquatic larvae (8.66%) which affirms its solid association with chitinase producing endosymbionts in the gut. Lepidophagy is further supported by the osteological observations. The perfect segregation of the functions such as food capture, ingestion and processing amongst the different types of teeth located in the oral cavity and pharyngeal region thus could be taken as evolutionary adaptations in scale eaters to support lepidophagy. Specialized arrangement of the esophageal and stomach epithelial folds could be altogether taken as an adaptation with the end goal to frame the scale stacks and accordingly facilitate the handling and processing of chitin-rich bolus. The esophageal mucosa is simple squamous epithelium instead of stratified epithelium with numerous goblet cells to withstand the mechanical harm by hard-food stuff like scales. The cardiac and fundic regions exhibited large number tubular gastric glands with simple columnar epithelium. Surface cells of all three stomach regions stained positive for PAS staining. The intestine is without pyloric caeca and is divided into anterior and posterior region. Histologically it is characterized by simple columnar epithelium with brush border and numerous goblet cells throughout its length. Presence of large number microvilli on anterior and posterior intestine was noticeable. Intestinal goblet cells reacted positively to PAS, AB (pH 1) and AB (pH 2.5). Secretions of goblet cells are important for lubricating and protecting the epithelium. The results of present investigation improve the understanding of the digestive physiology of scale eaters in general and P. khavalchor in particular. Overall, our data indicates that though P. khavalchor predominantly feeds on scale, the digestive physiology is adapted to support dual feeding habit (lepidophagy and carnivory).}, }
@article {pmid30949677, year = {2019}, author = {Pillonel, T and Bertelli, C and Aeby, S and de Barsy, M and Jacquier, N and Kebbi-Beghdadi, C and Mueller, L and Vouga, M and Greub, G}, title = {Sequencing the Obligate Intracellular Rhabdochlamydia helvetica within Its Tick Host Ixodes ricinus to Investigate Their Symbiotic Relationship.}, journal = {Genome biology and evolution}, volume = {11}, number = {4}, pages = {1334-1344}, pmid = {30949677}, issn = {1759-6653}, mesh = {Animals ; Chlamydiales/*genetics/metabolism ; Female ; Gene Transfer, Horizontal ; *Genome, Bacterial ; *Host-Parasite Interactions ; Ixodes/*microbiology ; Symbiosis ; }, abstract = {The Rhabdochlamydiaceae family is one of the most widely distributed within the phylum Chlamydiae, but most of its members remain uncultivable. Rhabdochlamydia 16S rRNA was recently reported in more than 2% of 8,534 pools of ticks from Switzerland. Shotgun metagenomics was performed on a pool of five female Ixodes ricinus ticks presenting a high concentration of chlamydial DNA, allowing the assembly of a high-quality draft genome. About 60% of sequence reads originated from a single bacterial population that was named "Candidatus Rhabdochlamydia helvetica" whereas only few thousand reads mapped to the genome of "Candidatus Midichloria mitochondrii," a symbiont normally observed in all I. ricinus females. The 1.8 Mbp genome of R. helvetica is smaller than other Chlamydia-related bacteria. Comparative analyses with other chlamydial genomes identified transposases of the PD-(D/E)XK nuclease family that are unique to this new genome. These transposases show evidence of interphylum horizontal gene transfers between multiple arthropod endosymbionts, including Cardinium spp. (Bacteroidetes) and diverse proteobacteria such as Wolbachia, Rickettsia spp. (Rickettsiales), and Caedimonas varicaedens (Holosporales). Bacterial symbionts were previously suggested to provide B-vitamins to hematophagous hosts. However, incomplete metabolic capacities including for B-vitamin biosynthesis, high bacterial density and limited prevalence suggest that R. helvetica is parasitic rather than symbiotic to its host. The identification of novel Rhabdochlamydia strains in different hosts and their sequencing will help understanding if members of this genus have become highly specialized parasites with reduced genomes, like the Chlamydiaceae, or if they could be pathogenic to humans using ticks as a transmission vector.}, }
@article {pmid30941581, year = {2019}, author = {Han, W and Fan, X and Teng, L and Kaczurowski, MJS and Zhang, X and Xu, D and Yin, Y and Ye, N}, title = {Identification, classification, and evolution of putative xylosyltransferases from algae.}, journal = {Protoplasma}, volume = {256}, number = {4}, pages = {1119-1132}, pmid = {30941581}, issn = {1615-6102}, mesh = {Charophyceae/genetics ; Chlorophyta/*enzymology/genetics ; Embryophyta ; Gene Expression Regulation, Plant ; Pentosyltransferases/chemistry/*classification/*genetics/metabolism ; Phaeophyta/*enzymology/genetics ; Phylogeny ; Polysaccharides ; Protein Conformation ; Rhodophyta/*enzymology/genetics ; }, abstract = {Xylosyltransferases (XylTs) play key roles in the biosynthesis of many different polysaccharides. These enzymes transfer D-xylose from UDP-xylose to substrate acceptors. In this study, we identified 30 XylTs from primary endosymbionts (green algae, red algae, and glaucophytes) and secondary or higher endosymbionts (brown algae, diatoms, Eustigmatophyceae, Pelagophyceae, and Cryptophyta). We performed comparative phylogenetic studies on key XylT subfamilies, and investigated the functional divergence of genes using RNA-Seq. Of the 30 XylTs, one β-1,4-XylT IRX14-related, one β-1,4 XylT IRX10L-related, and one xyloglucan 6-XylT 1-related gene were identified in the Charophyta, showing strong similarities to their land plant descendants. This implied the ancient occurrence of xylan and xyloglucan biosynthetic machineries in Charophyta. The other 27 XylTs were identified as UDP-D-xylose: L-fucose-α-1,3-D-XylT (FucXylT) type that specifically transferred D-xylose to fucose. We propose that FucXylTs originated from the last eukaryotic common ancestor, rather than being plant specific, because they are also distributed in Choanoflagellatea and Echinodermata. Considering the evidence from many aspects, we hypothesize that the FucXylTs likely participated in fucoidan biosynthesis in brown algae. We provide the first insights into the evolutionary history and functional divergence of FucXylT in algal biology.}, }
@article {pmid30941110, year = {2019}, author = {Moelling, K and Broecker, F}, title = {Viruses and Evolution - Viruses First? A Personal Perspective.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {523}, pmid = {30941110}, issn = {1664-302X}, abstract = {The discovery of exoplanets within putative habitable zones revolutionized astrobiology in recent years. It stimulated interest in the question about the origin of life and its evolution. Here, we discuss what the roles of viruses might have been at the beginning of life and during evolution. Viruses are the most abundant biological entities on Earth. They are present everywhere, in our surrounding, the oceans, the soil and in every living being. Retroviruses contributed to about half of our genomic sequences and to the evolution of the mammalian placenta. Contemporary viruses reflect evolution ranging from the RNA world to the DNA-protein world. How far back can we trace their contribution? Earliest replicating and evolving entities are the ribozymes or viroids fulfilling several criteria of life. RNA can perform many aspects of life and influences our gene expression until today. The simplest structures with non-protein-coding information may represent models of life built on structural, not genetic information. Viruses today are obligatory parasites depending on host cells. Examples of how an independent lifestyle might have been lost include mitochondria, chloroplasts, Rickettsia and others, which used to be autonomous bacteria and became intracellular parasites or endosymbionts, thereby losing most of their genes. Even in vitro the loss of genes can be recapitulated all the way from coding to non-coding RNA. Furthermore, the giant viruses may indicate that there is no sharp border between living and non-living entities but an evolutionary continuum. Here, it is discussed how viruses can lose and gain genes, and that they are essential drivers of evolution. This discussion may stimulate the thinking about viruses as early possible forms of life. Apart from our view "viruses first", there are others such as "proteins first" and "metabolism first."}, }
@article {pmid30940213, year = {2019}, author = {Tsagmo Ngoune, JM and Reveillaud, J and Sempere, G and Njiokou, F and Melachio, TT and Abate, L and Tchioffo, MT and Geiger, A}, title = {The composition and abundance of bacterial communities residing in the gut of Glossina palpalis palpalis captured in two sites of southern Cameroon.}, journal = {Parasites &amp; vectors}, volume = {12}, number = {1}, pages = {151}, pmid = {30940213}, issn = {1756-3305}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Cameroon ; Gastrointestinal Microbiome ; Molecular Typing ; RNA, Bacterial ; RNA, Ribosomal, 16S ; Tsetse Flies/*microbiology ; }, abstract = {BACKGROUND: A number of reports have demonstrated the role of insect bacterial flora on their host's physiology and metabolism. The tsetse host and vector of trypanosomes responsible for human sleeping sickness (human African trypanosomiasis, HAT) and nagana in animals (African animal trypanosomiasis, AAT) carry bacteria that influence its diet and immune processes. However, the mechanisms involved in these processes remain poorly documented. This underscores the need for increased research into the bacterial flora composition and structure of tsetse flies. The aim of this study was to identify the diversity and relative abundance of bacterial genera in Glossina palpalis palpalis flies collected in two trypanosomiasis foci in Cameroon.<br><br>METHODS: Samples of G. p. palpalis which were either negative or naturally trypanosome-positive were collected in two foci located in southern Cameroon (Campo and Bipindi). Using the V3V4 and V4 variable regions of the small subunit of the 16S ribosomal RNA gene, we analyzed the respective bacteriome of the flies' midguts.<br><br>RESULTS: We identified ten bacterial genera. In addition, we observed that the relative abundance of the obligate endosymbiont Wigglesworthia was highly prominent (around 99%), regardless of the analyzed region. The remaining genera represented approximately 1% of the bacterial flora, and were composed of Salmonella, Spiroplasma, Sphingomonas, Methylobacterium, Acidibacter, Tsukamurella, Serratia, Kluyvera and an unidentified bacterium. The genus Sodalis was present but with a very low abundance. Globally, no statistically significant difference was found between the bacterial compositions of flies from the two foci, and between positive and trypanosome-negative flies. However, Salmonella and Serratia were only described in trypanosome-negative flies, suggesting a potential role for these two bacteria in fly refractoriness to trypanosome infection. In addition, our study showed the V4 region of the small subunit of the 16S ribosomal RNA gene was more efficient than the V3V4 region at describing the totality of the bacterial diversity.<br><br>CONCLUSIONS: A very large diversity of bacteria was identified with the discovering of species reported to secrete anti-parasitic compounds or to modulate vector competence in other insects. For future studies, the analyses should be enlarged with larger sampling including foci from several countries.}, }
@article {pmid30937430, year = {2019}, author = {Hill, GE}, title = {Reconciling the Mitonuclear Compatibility Species Concept with Rampant Mitochondrial Introgression.}, journal = {Integrative and comparative biology}, volume = {59}, number = {4}, pages = {912-924}, doi = {10.1093/icb/icz019}, pmid = {30937430}, issn = {1557-7023}, mesh = {*Biological Evolution ; Cell Nucleus/*genetics ; Eukaryota/*genetics ; Genetic Introgression ; Genome, Mitochondrial/*genetics ; Genotype ; }, abstract = {The mitonuclear compatibility species concept defines a species as a population that is genetically isolated from other populations by uniquely coadapted mitochondrial (mt) and nuclear genes. A key prediction of this hypothesis is that the mt genotype of each species will be functionally distinct and that introgression of mt genomes will be prevented by mitonuclear incompatibilities that arise when heterospecific mt and nuclear genes attempt to cofunction to enable aerobic respiration. It has been proposed, therefore, that the observation of rampant introgression of mt genotypes from one species to another constitutes a strong refutation of the mitonuclear speciation. The displacement of a mt genotype from a nuclear background with which it co-evolved to a foreign nuclear background will necessarily lead to fitness loss due to mitonuclear incompatibilities. Here I consider two potential benefits of mt introgression between species that may, in some cases, overcome fitness losses arising from mitonuclear incompatibilities. First, the introgressed mt genotype may be better adapted to the local environment than the native mt genotype such that higher fitness is achieved through improved adaptation via introgression. Second, if the mitochondria of the recipient taxa carry a high mutational load, then introgression of a foreign, less corrupt mt genome may enable the recipient taxa to escape its mutational load and gain a fitness advantage. Under both scenarios, fitness gains from novel mt genotypes could theoretically compensate for the fitness that is lost via mitonuclear incompatibility. I also consider the role of endosymbionts in non-adaptive rampant introgression of mt genomes. I conclude that rampant introgression is not necessarily evidence against the idea of tight mitonuclear coadaptation or the mitonuclear compatibility species concept. Rampant mt introgression will typically lead to erasure of species but in some cases could lead to hybrid speciation.}, }
@article {pmid30936488, year = {2019}, author = {Spang, A and Stairs, CW and Dombrowski, N and Eme, L and Lombard, J and Caceres, EF and Greening, C and Baker, BJ and Ettema, TJG}, title = {Proposal of the reverse flow model for the origin of the eukaryotic cell based on comparative analyses of Asgard archaeal metabolism.}, journal = {Nature microbiology}, volume = {4}, number = {7}, pages = {1138-1148}, pmid = {30936488}, issn = {2058-5276}, mesh = {Archaea/classification/*genetics/*metabolism ; Archaeal Proteins/genetics ; *Biological Evolution ; Eukaryotic Cells/metabolism/*physiology ; Genome, Archaeal/genetics ; Heterotrophic Processes ; Hydrogen/metabolism ; Metabolic Networks and Pathways ; *Models, Biological ; Oxidation-Reduction ; *Phylogeny ; Symbiosis ; }, abstract = {The origin of eukaryotes represents an unresolved puzzle in evolutionary biology. Current research suggests that eukaryotes evolved from a merger between a host of archaeal descent and an alphaproteobacterial endosymbiont. The discovery of the Asgard archaea, a proposed archaeal superphylum that includes Lokiarchaeota, Thorarchaeota, Odinarchaeota and Heimdallarchaeota suggested to comprise the closest archaeal relatives of eukaryotes, has helped to elucidate the identity of the putative archaeal host. Whereas Lokiarchaeota are assumed to employ a hydrogen-dependent metabolism, little is known about the metabolic potential of other members of the Asgard superphylum. We infer the central metabolic pathways of Asgard archaea using comparative genomics and phylogenetics to be able to refine current models for the origin of eukaryotes. Our analyses indicate that Thorarchaeota and Lokiarchaeota encode proteins necessary for carbon fixation via the Wood-Ljungdahl pathway and for obtaining reducing equivalents from organic substrates. By contrast, Heimdallarchaeum LC2 and LC3 genomes encode enzymes potentially enabling the oxidation of organic substrates using nitrate or oxygen as electron acceptors. The gene repertoire of Heimdallarchaeum AB125 and Odinarchaeum indicates that these organisms can ferment organic substrates and conserve energy by coupling ferredoxin reoxidation to respiratory proton reduction. Altogether, our genome analyses suggest that Asgard representatives are primarily organoheterotrophs with variable capacity for hydrogen consumption and production. On this basis, we propose the 'reverse flow model', an updated symbiogenetic model for the origin of eukaryotes that involves electron or hydrogen flow from an organoheterotrophic archaeal host to a bacterial symbiont.}, }
@article {pmid30930872, year = {2019}, author = {Ali, H and Muhammad, A and Sanda, NB and Huang, Y and Hou, Y}, title = {Pyrosequencing Uncovers a Shift in Bacterial Communities Across Life Stages of Octodonta nipae (Coleoptera: Chrysomelidae).}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {466}, pmid = {30930872}, issn = {1664-302X}, abstract = {Bacterial symbionts of insects affect a wide array of host traits including fitness and immunity. Octodonta nipae (Maulik), commonly known as hispid leaf beetle is a destructive palm pest around the world. Understanding the dynamics of microbiota is essential to unravel the complex interplay between O. nipae and its bacterial symbionts. In this study, bacterial 16S rRNA V3-V4 region was targeted to decipher the diversity and dynamics of bacterial symbionts across different life stages [eggs, larvae, pupae, and adult (male and female)] and reproductive organs (ovaries and testis) of O. nipae. Clustering analysis at ≥97% similarity threshold produced 3,959 operational taxonomic units (OTUs) that belonged to nine different phyla. Proteobacteria, Actinobacteria, and Firmicutes represented the bulk of taxa that underwent notable changes during metamorphosis. Enterobacteriaceae and Dermabacteraceae were the most abundant families in immature stages (eggs, larvae, and pupae), while Anaplasmataceae family was dominated in adults (male and female) and reproductive organs (ovaries and testis). The genus Serratia and Lactococcus were most abundant in eggs, whereas Pantoea and Brachybacterium represented the bulk of larvae and pupae microbiota. Interestingly the genus Wolbachia found positive to all tested samples and was recorded extremely high (>64%) in the adults and reproductive organs. The bacteria varied across the developmental stages and responsible for various metabolic activities. Selection choice exerted by the insect host as a result of its age or developmental stage could be the main reason to ascertain the shift in the bacteria populations. Maternally inherited Wolbachia was found to be an obligate endosymbiont infecting all tested life stages, body parts, and tissues. These outcomes foster our understanding of the intricate associations between bacteria and O. nipae and will incorporate in devising novel pest control strategies against this palm pest.}, }
@article {pmid30922601, year = {2019}, author = {Buysse, M and Plantard, O and McCoy, KD and Duron, O and Menard, C}, title = {Tissue localization of Coxiella-like endosymbionts in three European tick species through fluorescence in situ hybridization.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {4}, pages = {798-804}, doi = {10.1016/j.ttbdis.2019.03.014}, pmid = {30922601}, issn = {1877-9603}, mesh = {Animals ; Coxiella/*isolation &amp; purification/physiology ; DNA, Bacterial ; Dermacentor/anatomy &amp; histology/microbiology ; Europe ; Female ; In Situ Hybridization, Fluorescence ; Ixodidae/anatomy &amp; histology/microbiology ; Malpighian Tubules/microbiology ; Ovary/microbiology ; Phylogeny ; Salivary Glands/microbiology ; *Symbiosis ; Ticks/anatomy &amp; histology/*microbiology ; }, abstract = {Ticks are commonly infected by Coxiella-like endosymbionts (Coxiella-LE) which are thought to supply missing B vitamin nutrients required for blood digestion.While this nutritional symbiosis is essential for the survival and reproduction of infected tick species, our knowledge of where Coxiella-LE is localized in tick tissues is partial at best since previous studies have focused on a limited number of Asian or American tick species. To fill this gap, we investigated the tissue localization of Coxiella-LE in three European tick species, Ornithodoros maritimus, Dermacentor marginatus and Ixodes hexagonus, using a diagnostic fluorescence in situ hybridization (FISH) assay, combined with PCR-based detection. Specific fluorescent foci were observed in several tick tissues. We visualized a pronounced tissue tropism of Coxiella-LE for tick ovaries and Malpighian tubules, a pattern suggestive of a high degree of lifestyle specialization toward mutualism: infection of the ovaries is indicative of transovarial transmission, whereas infection of the Malpighian tubules suggests a nutritional function. We postulate that Malpighian tubules are key organs for the nutritional symbiosis, notably the synthesis of B vitamins by Coxiella-LE, whereas the infection of the ovaries ensures vertical transmission of the symbionts to future generations. We also detected occasional infections in other organs, such as salivary glands and the midgut. Finally, we discuss the potential significance of the different tissue tropism for tick biology.}, }
@article {pmid30917916, year = {2019}, author = {Hajialilo, E and Rezaeian, M and Niyyati, M and Pourmand, MR and Mohebali, M and Norouzi, M and Razavi Pashabeyg, K and Rezaie, S and Khodavaisy, S}, title = {Molecular characterization of bacterial, viral and fungal endosymbionts of Acanthamoeba isolates in keratitis patients of Iran.}, journal = {Experimental parasitology}, volume = {200}, number = {}, pages = {48-54}, doi = {10.1016/j.exppara.2019.03.013}, pmid = {30917916}, issn = {1090-2449}, mesh = {Acanthamoeba/isolation &amp; purification/microbiology/pathogenicity/*physiology ; Acanthamoeba Keratitis/*complications ; Adenoviruses, Human/genetics/*isolation &amp; purification/physiology ; Animals ; Bacteria/genetics/*isolation &amp; purification ; Chlorocebus aethiops ; Cloning, Molecular ; Communicable Diseases/microbiology/transmission ; Contact Lenses/parasitology ; Cornea/parasitology ; Disease Reservoirs ; Fungi/genetics/*isolation &amp; purification ; Humans ; Iran ; Polymerase Chain Reaction ; *Symbiosis ; Vero Cells ; Virulence ; }, abstract = {Free-living amoebae belong to the genus Acanthamoeba; can feed on microbial population by phagocytosis, and with the capability to act as a reservoir and a vehicle of microorganisms to susceptible host. Therefore, the role of endosymbiosis in the pathogenesis of Acanthamoeba is complex and not fully understood. The aim of the present study was to identify bacterial, fungal, and human adenovirus (HADV) endosymbionts as well as evaluating the endosymbionts role of such organisms in the pathogenesis of Acanthamoeba in keratitis patients living in Iran. Fifteen Acanthamoeba (T4 genotype) isolates were recovered from corneal scrapes and contact lenses of patients with keratitis. Cloning and purification was performed for all isolate. Gram staining was performed to identify bacterial endosymbionts. DNA extraction, PCR, and nested PCR was set up to identify endosymbiont of amoeba. Evaluation of pathogenicity was conducted by osmo-tolerance and thermo-tolerance assays and cell culture, and then CPE (cytopathic effect) was survey. Statistical analysis was used between Acanthamoeba associated endosymbionts and Acanthamoeba without endosymbiont at 24, 48, 72, and 96 h. A p value < 0.05 was considered as significant, statistically. A total of 9 (60%) Acanthamoeba (T4 genotypes) isolates were successfully cloned for detecting microorganism endosymbionts. The only isolate negative for the presence of endosymbiont was ICS9. ICS7 (Pseudomonas aeruginosa, Aspergillus sp., and human adenovirus endosymbionts) and ICS2 (Escherichia coli endosymbiont) isolates were considered as Acanthamoeba associated endosymbionts. ICS7 and ICS2 isolates were highly pathogen whereas ICS9 isolate showed low pathogenicity in pathogenicity evaluated. Positive CPE for ICS7 and ICS2 isolates and negative CPE for ICS9 isolate were observed in cell culture. The average number of cells, trophozoites, and cysts among ICS7, ICS2, and ICS9 isolates at 24, 48, 72, and 96 h was significant. This is the first survey on microbial endosymbionts of Acanthamoeba in keratitis patients of Iran, and also the first report of Aspergillus sp, Achromobacter sp., Microbacterium sp., Brevibacillus sp, Brevundimonas sp and Mastadenovirus sp in Acanthamoeba as endosymbionts. Our study demonstrated that microbial endosymbionts can affect the pathogenicity of Acanthamoeba; however, further research is required to clarify the exact pattern of symbiosis, in order to modify treatment protocol.}, }
@article {pmid30915518, year = {2019}, author = {Kolasa, M and Ścibior, R and Mazur, MA and Kubisz, D and Dudek, K and Kajtoch, &#x141;}, title = {How Hosts Taxonomy, Trophy, and Endosymbionts Shape Microbiome Diversity in Beetles.}, journal = {Microbial ecology}, volume = {78}, number = {4}, pages = {995-1013}, pmid = {30915518}, issn = {1432-184X}, mesh = {Animals ; Bacteria/*classification ; Bacterial Physiological Phenomena ; Coleoptera/classification/*microbiology/*physiology ; Feeding Behavior ; Microbiota/*physiology ; Phylogeny ; *Symbiosis ; }, abstract = {Bacterial communities play a crucial role in the biology, ecology, and evolution of multicellular organisms. In this research, the microbiome of 24 selected beetle species representing five families (Carabidae, Staphylinidae, Curculionidae, Chrysomelidae, Scarabaeidae) and three trophic guilds (carnivorous, herbivorous, detrivorous) was examined using 16S rDNA sequencing on the Illumina platform. The aim of the study was to compare diversity within and among species on various levels of organization, including evaluation of the impact of endosymbiotic bacteria. Collected data showed that beetles possess various bacterial communities and that microbiota of individuals of particular species hosts are intermixed. The most diverse microbiota were found in Carabidae and Scarabaeidae; the least diverse, in Staphylinidae. On higher organization levels, the diversity of bacteria was more dissimilar between families, while the most distinct with respect to their microbiomes were trophic guilds. Moreover, eight taxa of endosymbiotic bacteria were detected including common genera such as Wolbachia, Rickettsia, and Spiroplasma, as well as the rarely detected Cardinium, Arsenophonus, Buchnera, Sulcia, Regiella, and Serratia. There were no correlations among the abundance of the most common Wolbachia and Rickettsia; a finding that does not support the hypothesis that these bacteria occur interchangeably. The abundance of endosymbionts only weakly and negatively correlates with diversity of the whole microbiome in beetles. Overall, microbiome diversity was found to be more dependent on host phylogeny than on the abundance of endosymbionts. This is the first study in which bacteria diversity is compared between numerous species of beetles in a standardized manner.}, }
@article {pmid30914689, year = {2019}, author = {Naranjo, E and Merfa, MV and Ferreira, V and Jain, M and Davis, MJ and Bahar, O and Gabriel, DW and De La Fuente, L}, title = {Liberibacter crescens biofilm formation in vitro: establishment of a model system for pathogenic 'Candidatus Liberibacter spp.'.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {5150}, pmid = {30914689}, issn = {2045-2322}, mesh = {Biofilms/*growth &amp; development ; *Lab-On-A-Chip Devices ; Liberibacter ; *Microfluidic Analytical Techniques ; *Models, Biological ; *Rhizobiaceae/pathogenicity/physiology ; Serum Albumin, Bovine/chemistry ; }, abstract = {The Liberibacter genus comprises insect endosymbiont bacterial species that cause destructive plant diseases, including Huanglongbing in citrus and zebra chip in potato. To date, pathogenic 'Candidatus Liberibacter spp.' (CLs) remain uncultured, therefore the plant-associated Liberibacter crescens (Lcr), only cultured species of the genus, has been used as a biological model for in vitro studies. Biofilm formation by CLs has been observed on the outer midgut surface of insect vectors, but not in planta. However, the role of biofilm formation in the life cycle of these pathogens remains unclear. Here, a model system for studying CLs biofilms was developed using Lcr. By culture media modifications, bovine serum albumin (BSA) was identified as blocking initial cell-surface adhesion. Removal of BSA allowed for the first time observation of Lcr biofilms. After media optimization for biofilm formation, we demonstrated that Lcr attaches to surfaces, and form cell aggregates embedded in a polysaccharide matrix both in batch cultures and under flow conditions in microfluidic chambers. Biofilm structures may represent excellent adaptive advantages for CLs during insect vector colonization helping with host retention, immune system evasion, and transmission. Future studies using the Lcr model established here will help in the understanding of the biology of CLs.}, }
@article {pmid30914397, year = {2019}, author = {Konecka, E and Olszanowski, Z and Koczura, R}, title = {Wolbachia of phylogenetic supergroup E identified in oribatid mite Gustavia microcephala (Acari: Oribatida).}, journal = {Molecular phylogenetics and evolution}, volume = {135}, number = {}, pages = {230-235}, doi = {10.1016/j.ympev.2019.03.019}, pmid = {30914397}, issn = {1095-9513}, mesh = {Animals ; Base Sequence ; DNA, Ribosomal/genetics ; Likelihood Functions ; Mites/*microbiology ; *Phylogeny ; Wolbachia/*classification/genetics ; }, abstract = {Heritable endosymbionts have been observed in arthropod and nematode hosts. The most-known among them is Wolbachia. Although the bacterium was previously identified in oribatid mites (Acari: Oribatida), it was not assigned to any phylogenetic group. Endosymbionts have a profound influence on their hosts, playing various functions that affect invertebrate's biology such as changing the way of reproduction. Oribatida provide the very unique examples of groups in which even whole families appear to be thelytokous, so we considered that it is worth to investigate the occurrence of endosymbiotic microorganisms in oribatid mites, especially that the knowledge on the symbionts occurrence in this invertebrate group is negligible. We report for the first time Wolbachia in oribatid mite Gustavia microcephala. The sequences of 16S rDNA, gltA, and ftsZ genes of the endosymbiont from the mite showed the highest similarity to Wolbachia found in Collembola. Phylogenetic analysis based on single gene and concatenated alignments of three genes revealed that the bacteria from G. microcephala and Collembola were related and clustered together with supergroup E. Relatively close relationship of Wolbachia from oribatid and collembolan hosts might mean at the evolutionary scale that horizontal transfer of bacteria between these two groups of invertebrates may take place.}, }
@article {pmid30912316, year = {2019}, author = {Guo, J and Liu, X and Poncelet, N and He, K and Francis, F and Wang, Z}, title = {Detection and geographic distribution of seven facultative endosymbionts in two Rhopalosiphum aphid species.}, journal = {MicrobiologyOpen}, volume = {8}, number = {8}, pages = {e00817}, pmid = {30912316}, issn = {2045-8827}, mesh = {Animals ; Aphids/*microbiology ; China ; Europe ; Gammaproteobacteria/classification/*isolation &amp; purification ; *Phylogeography ; Rickettsiales/classification/*isolation &amp; purification ; Spiroplasma/classification/*isolation &amp; purification ; *Symbiosis ; }, abstract = {Study of the mutualistic associations between facultative symbionts and aphids are developed only in a few models. That survey on the situation and distribution of the symbionts in a certain area is helpful to obtain clues for the acquisition and spread of them as well as their roles played in host evolution. To understand the infection patterns of seven facultative symbionts (Serratia symbiotica, Hamiltonella defensa, Regiella insecticola, Rickettsia, Spiroplasma, Wolbachia, and Arsenophonus) in Rhopalosiphum padi (Linnaeus) and Rhopalosiphum maidis (Fitch), we collected 882 R. maidis samples (37 geographical populations) from China and 585 R. padi samples (32 geographical populations) from China and Europe. Results showed that both species were widely infected with various symbionts and totally 50.8% of R. maidis and 50.1% of R. padi were multi-infected with targeted symbionts. However, very few Rhopalosiphum aphids were infected with S. symbiotica. The infection frequencies of some symbionts were related to the latitude of collecting sites, suggesting the importance of environmental factors in shaping the geographic distribution of facultative symbionts. Also, R. maidis and R. padi were infected with different H. defensa strains based on phylogenetic analysis which may be determined by host ×symbiont genotype interactions. According to our results, the ubiquitous symbionts may play important roles in the evolution of their host aphid and their impacts on adaptation of R. padi and R. maidis were discussed as well.}, }
@article {pmid30905896, year = {2019}, author = {Uchi, N and Fukudome, M and Nozaki, N and Suzuki, M and Osuki, KI and Shigenobu, S and Uchiumi, T}, title = {Antimicrobial Activities of Cysteine-rich Peptides Specific to Bacteriocytes of the Pea Aphid Acyrthosiphon pisum.}, journal = {Microbes and environments}, volume = {34}, number = {2}, pages = {155-160}, pmid = {30905896}, issn = {1347-4405}, mesh = {Animals ; Anti-Infective Agents/chemical synthesis/chemistry/*pharmacology ; Aphids/*metabolism/microbiology ; Buchnera/physiology ; Cell Membrane Permeability/drug effects/genetics ; Cysteine/*chemistry ; Escherichia coli/cytology/drug effects/genetics ; Insect Proteins/chemical synthesis/chemistry/*pharmacology ; Mutation ; Peptides/chemical synthesis/chemistry/*pharmacology ; Sinorhizobium meliloti/drug effects/genetics ; Symbiosis ; }, abstract = {Aphids have a mutualistic relationship with the bacterial endosymbiont Buchnera aphidicola. We previously reported seven cysteine-rich peptides in the pea aphid Acyrthosiphon pisum and named them Bacteriocyte-specific Cysteine-Rich (BCR) peptides; these peptides are exclusively expressed in bacteriocytes, special aphid cells that harbor symbionts. Similar symbiotic organ-specific cysteine-rich peptides identified in the root nodules of leguminous plants are named Nodule-specific Cysteine-Rich (NCR) peptides. NCR peptides target rhizobia in the nodules and are essential for symbiotic nitrogen fixation. A BacA (membrane protein) mutant of Sinorhizobium is sensitive to NCR peptides and is unable to establish symbiosis. Based on the structural and expressional similarities between BCR peptides and NCR peptides, we hypothesized that aphid BCR peptides exhibit antimicrobial activity, similar to some NCR peptides. We herein synthesized BCR peptides and investigated their antimicrobial activities and effects on the bacterial membrane of Escherichia coli. The peptides BCR1, BCR3, BCR5, and BCR8 exhibited antimicrobial activities with increased membrane permeability. An sbmA mutant of E. coli, a homolog of bacA of S. meliloti, was more sensitive to BCR peptides than the wild type. Our results suggest that BCR peptides have properties that may be required to control the endosymbiont, similar to NCR peptides in legumes.}, }
@article {pmid30894837, year = {2019}, author = {Tolley, SJA and Nonacs, P and Sapountzis, P}, title = {Wolbachia Horizontal Transmission Events in Ants: What Do We Know and What Can We Learn?.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {296}, pmid = {30894837}, issn = {1664-302X}, abstract = {While strict vertical transmission insures the durability of intracellular symbioses, phylogenetic incongruences between hosts and endosymbionts suggest horizontal transmission must also occur. These horizontal acquisitions can have important implications for the biology of the host. Wolbachia is one of the most ecologically successful prokaryotes in arthropods, infecting an estimated 50-70% of all insect species. Much of this success is likely due to the fact that, in arthropods, Wolbachia is notorious for manipulating host reproduction to favor transmission through the female germline. However, its natural potential for horizontal transmission remains poorly understood. Here we evaluate the fundamental prerequisites for successful horizontal transfer, including necessary environmental conditions, genetic potential of bacterial strains, and means of mediating transfers. Furthermore, we revisit the relatedness of Wolbachia strains infecting the Panamanian leaf-cutting ant, Acromyrmex echinatior, and its inquiline social parasite, Acromyrmex insinuator, and compare our results to a study published more than 15 years ago by Van Borm et al. (2003). The results of this pilot study prompt us to reevaluate previous notions that obligate social parasitism reliably facilitates horizontal transfer and suggest that not all Wolbachia strains associated with ants have the same genetic potential for horizontal transmission.}, }
@article {pmid30893296, year = {2019}, author = {Fattouh, N and Cazevieille, C and Landmann, F}, title = {Wolbachia endosymbionts subvert the endoplasmic reticulum to acquire host membranes without triggering ER stress.}, journal = {PLoS neglected tropical diseases}, volume = {13}, number = {3}, pages = {e0007218}, pmid = {30893296}, issn = {1935-2735}, mesh = {Animals ; Cell Line ; Drosophila melanogaster/cytology/*microbiology ; Endoplasmic Reticulum/metabolism/*microbiology ; Gene Expression Profiling ; Golgi Apparatus/metabolism/microbiology ; Host-Pathogen Interactions ; Intracellular Membranes/metabolism/*microbiology ; Stress, Physiological/genetics/*physiology ; Symbiosis/genetics/*physiology ; Vacuoles/microbiology ; Wolbachia/pathogenicity/*physiology ; }, abstract = {The reproductive parasites Wolbachia are the most common endosymbionts on earth, present in a plethora of arthropod species. They have been introduced into mosquitos to successfully prevent the spread of vector-borne diseases, yet the strategies of host cell subversion underlying their obligate intracellular lifestyle remain to be explored in depth in order to gain insights into the mechanisms of pathogen-blocking. Like some other intracellular bacteria, Wolbachia reside in a host-derived vacuole in order to replicate and escape the immune surveillance. Using here the pathogen-blocking Wolbachia strain from Drosophila melanogaster, introduced into two different Drosophila cell lines, we show that Wolbachia subvert the endoplasmic reticulum to acquire their vacuolar membrane and colonize the host cell at high density. Wolbachia redistribute the endoplasmic reticulum, and time lapse experiments reveal tight coupled dynamics suggesting important signalling events or nutrient uptake. Wolbachia infection however does not affect the tubular or cisternal morphologies. A fraction of endoplasmic reticulum becomes clustered, allowing the endosymbionts to reside in between the endoplasmic reticulum and the Golgi apparatus, possibly modulating the traffic between these two organelles. Gene expression analyses and immunostaining studies suggest that Wolbachia achieve persistent infections at very high titers without triggering endoplasmic reticulum stress or enhanced ERAD-driven proteolysis, suggesting that amino acid salvage is achieved through modulation of other signalling pathways.}, }
@article {pmid30891514, year = {2019}, author = {Sprong, H and Fonville, M and Docters van Leeuwen, A and Devillers, E and Ibañez-Justicia, A and Stroo, A and Hansford, K and Cull, B and Medlock, J and Heyman, P and Cochez, C and Weis, L and Silaghi, C and Moutailler, S}, title = {Detection of pathogens in Dermacentor reticulatus in northwestern Europe: evaluation of a high-throughput array.}, journal = {Heliyon}, volume = {5}, number = {2}, pages = {e01270}, pmid = {30891514}, issn = {2405-8440}, abstract = {BACKGROUND: The geographic distribution of Dermacentor reticulatus is expanding in Europe. Surveillance of this tick species and its pathogens is desirable, as it transmits pathogens of public and veterinary importance. A high-throughput real-time PCR-based array was used to screen 1.741 D. reticulatus ticks from Belgium, Germany, The Netherlands, and Great Britain for the presence of 28 tick-borne bacteria and twelve protozoan parasites. The presence of pathogen DNA was confirmed by conventional PCR followed by sequencing.<br><br>RESULTS: The array detected the presence of DNA from Borrelia spp. (7%), B. afzelii (0.1%), B. garinii (0.1%), B. spielmanii (0.1%), B. miyamotoi (0.2%), Anaplasma marginale (0.1%), A. phagocytophilum (0.1%), Ehrlichia canis (2%), Rickettsia helvetica (0.2%), spotted fever group Rickettsia (9.6%), Francisella tularensis or Francisella-like endosymbionts (95%), Coxiella burnettii (0.1%), Babesia divergens (0.2%), B. canis (0.9%) B. vogeli (5.6%), and Theileria equi (0.1%). Only the presence of B. canis and spotted fever group Rickettsia could be confirmed by conventional PCR and sequencing. The spotted fever Rickettsia-positive samples were all identified as R. raoultii.<br><br>CONCLUSIONS: We successfully detected and determined the prevalence of B. canis and R. raoultii in D. reticulatus. An high-throughput array that allows fast and comprehensive testing of tick-borne pathogens is advantageous for surveillance and future epidemiological studies. The importance of thorough validation of real-time PCR-based assays and careful interpretation is evident.}, }
@article {pmid30889213, year = {2019}, author = {Kanakala, S and Ghanim, M}, title = {Global genetic diversity and geographical distribution of Bemisia tabaci and its bacterial endosymbionts.}, journal = {PloS one}, volume = {14}, number = {3}, pages = {e0213946}, pmid = {30889213}, issn = {1932-6203}, mesh = {Animals ; Bacteria/genetics ; Bayes Theorem ; Genetic Variation ; Hemiptera/classification/*genetics/*microbiology ; Host Microbial Interactions/genetics ; Insect Control ; Phylogeny ; Symbiosis/genetics ; }, abstract = {Bemisia tabaci is one of the most threatening pests in agriculture, causing significant losses to many important crops on a global scale. The dramatic increase and availability of sequence data for B. tabaci species complex and its bacterial endosymbionts is critical for developing emerging sustainable pest management strategies which are based on pinpointing the global diversity of this important pest and its bacterial endosymbionts. To unravel the global genetic diversity of B. tabaci species complex focusing on its associated endosymbionts, along with Israeli whitefly populations collected in this study, we combined available sequences in databases, resulting in a total of 4,253 mitochondrial cytochrome oxidase I (mtCOI) sequences from 82 countries and 1,226 16S/23S rRNA endosymbiont sequences from 32 countries that were analyzed. Using Bayesian phylogenetic analysis, we identified two new B. tabaci groups within the species complex and described the global distribution of endosymbionts within this complex. Our analyses revealed complex divergence of the different endosymbiont sequences within the species complex, with overall one Hamiltonella, two Porteria (P1 and P2), two Arsenophonus (A1 and A2), two Wolbachia (super-groups O and B), four Cardinium (C1-C4) and three Rickettsia (R1-R3) groups were identified. Our comprehensive analysis provides an updated important resource for this globally important pest and its secondary symbionts, which have been a major subject for research in last three decades.}, }
@article {pmid30879203, year = {2019}, author = {Kohlmeier, MG and White, CE and Fowler, JE and Finan, TM and Oresnik, IJ}, title = {Galactitol catabolism in Sinorhizobium meliloti is dependent on a chromosomally encoded sorbitol dehydrogenase and a pSymB-encoded operon necessary for tagatose catabolism.}, journal = {Molecular genetics and genomics : MGG}, volume = {294}, number = {3}, pages = {739-755}, pmid = {30879203}, issn = {1617-4623}, mesh = {ATP-Binding Cassette Transporters/genetics/metabolism ; Bacterial Proteins/classification/*genetics/metabolism ; Chromosomes, Bacterial/genetics ; Fructose-Bisphosphate Aldolase/classification/genetics/metabolism ; Galactitol/*metabolism ; Gene Expression Regulation, Bacterial ; Hexoses/*metabolism ; L-Iditol 2-Dehydrogenase/*genetics/metabolism ; Operon/*genetics ; Phylogeny ; Plasmids/genetics ; Sinorhizobium meliloti/classification/*genetics/metabolism ; }, abstract = {The legume endosymbiont Sinorhizobium meliloti can utilize a broad range of carbon compounds to support its growth. The linear, six-carbon polyol galactitol is abundant in vascular plants and is metabolized in S. meliloti by the contribution of two loci SMb21372-SMb21377 and SMc01495-SMc01503 which are found on pSymB and the chromosome, respectively. The data suggest that several transport systems, including the chromosomal ATP-binding cassette (ABC) transporter smoEFGK, contribute to the uptake of galactitol, while the adjacent gene smoS encodes a protein for oxidation of galactitol into tagatose. Subsequently, genes SMb21374 and SMb21373, encode proteins that phosphorylate and epimerize tagatose into fructose-6-phosphate, which is further metabolized by the enzymes of the Entner-Doudoroff pathway. Of note, it was found that SMb21373, which was annotated as a 1,6-bis-phospho-aldolase, is homologous to the E. coli gene gatZ, which is annotated as encoding the non-catalytic subunit of a tagatose-1,6-bisphosphate aldolase heterodimer. When either of these genes was introduced into an Agrobacterium tumefaciens strain that carries a tagatose-6-phosphate epimerase mutation, they are capable of complementing the galactitol growth deficiency associated with this mutation, strongly suggesting that these genes are both epimerases. Phylogenetic analysis of the protein family (IPR012062) to which these enzymes belong, suggests that this misannotation is systemic throughout the family. S. meliloti galactitol catabolic mutants do not exhibit symbiotic deficiencies or the inability to compete for nodule occupancy.}, }
@article {pmid30873148, year = {2019}, author = {Lockwood, S and Brayton, KA and Daily, JA and Broschat, SL}, title = {Whole Proteome Clustering of 2,307 Proteobacterial Genomes Reveals Conserved Proteins and Significant Annotation Issues.}, journal = {Frontiers in microbiology}, volume = {10}, number = {}, pages = {383}, pmid = {30873148}, issn = {1664-302X}, abstract = {We clustered 8.76 M protein sequences deduced from 2,307 completely sequenced Proteobacterial genomes resulting in 707,311 clusters of one or more sequences of which 224,442 ranged in size from 2 to 2,894 sequences. To our knowledge this is the first study of this scale. We were surprised to find that no single cluster contained a representative sequence from all the organisms in the study. Given the minimal genome concept, we expected to find a shared set of proteins. To determine why the clusters did not have universal representation we chose four essential proteins, the chaperonin GroEL, DNA dependent RNA polymerase subunits beta and beta' (RpoB/RpoB'), and DNA polymerase I (PolA), representing fundamental cellular functions, and examined their cluster distribution. We found these proteins to be remarkably conserved with certain caveats. Although the groEL gene was universally conserved in all the organisms in the study, the protein was not represented in all the deduced proteomes. The genes for RpoB and RpoB' were missing from two genomes and merged in 88, and the sequences were sufficiently divergent that they formed separate clusters for 18 RpoB proteins (seven clusters) and 14 RpoB' proteins (three clusters). For PolA, 52 organisms lacked an identifiable sequence, and seven sequences were sufficiently divergent that they formed five separate clusters. Interestingly, organisms lacking an identifiable PolA and those with divergent RpoB/RpoB' were predominantly endosymbionts. Furthermore, we present a range of examples of annotation issues that caused the deduced proteins to be incorrectly represented in the proteome. These annotation issues made our task of determining protein conservation more difficult than expected and also represent a significant obstacle for high-throughput analyses.}, }
@article {pmid30867321, year = {2019}, author = {Taylor, MJ and von Geldern, TW and Ford, L and Hübner, MP and Marsh, K and Johnston, KL and Sjoberg, HT and Specht, S and Pionnier, N and Tyrer, HE and Clare, RH and Cook, DAN and Murphy, E and Steven, A and Archer, J and Bloemker, D and Lenz, F and Koschel, M and Ehrens, A and Metuge, HM and Chunda, VC and Ndongmo Chounna, PW and Njouendou, AJ and Fombad, FF and Carr, R and Morton, HE and Aljayyoussi, G and Hoerauf, A and Wanji, S and Kempf, DJ and Turner, JD and Ward, SA}, title = {Preclinical development of an oral anti-Wolbachia macrolide drug for the treatment of lymphatic filariasis and onchocerciasis.}, journal = {Science translational medicine}, volume = {11}, number = {483}, pages = {}, doi = {10.1126/scitranslmed.aau2086}, pmid = {30867321}, issn = {1946-6242}, support = {MC_PC_16052/MRC_/Medical Research Council/United Kingdom ; MR/L018756/1/MRC_/Medical Research Council/United Kingdom ; MR/R025401/1/MRC_/Medical Research Council/United Kingdom ; NC/M00175X/1/NC3RS_/National Centre for the Replacement, Refinement and Reduction of Animals in Research/United Kingdom ; }, mesh = {Administration, Oral ; Animals ; Disease Models, Animal ; Elephantiasis, Filarial/blood/*drug therapy/*microbiology ; Female ; Macrolides/*administration &amp; dosage/adverse effects/*therapeutic use ; Male ; Mice, Inbred BALB C ; Mice, SCID ; Onchocerciasis/blood/*drug therapy/*microbiology ; Treatment Outcome ; Tylosin/blood/chemical synthesis/chemistry/therapeutic use ; Wolbachia/*physiology ; }, abstract = {There is an urgent global need for a safe macrofilaricide drug to accelerate elimination of the neglected tropical diseases onchocerciasis and lymphatic filariasis. From an anti-infective compound library, the macrolide veterinary antibiotic, tylosin A, was identified as a hit against Wolbachia This bacterial endosymbiont is required for filarial worm viability and fertility and is a validated target for macrofilaricidal drugs. Medicinal chemistry was undertaken to develop tylosin A analogs with improved oral bioavailability. Two analogs, A-1535469 and A-1574083, were selected. Their efficacy was tested against the gold-standard second-generation tetracycline antibiotics, doxycycline and minocycline, in mouse and gerbil infection models of lymphatic filariasis (Brugia malayi and Litomosoides sigmodontis) and onchocerciasis (Onchocerca ochengi). A 1- or 2-week course of oral A-1535469 or A-1574083 provided >90% Wolbachia depletion from nematodes in infected animals, resulting in a block in embryogenesis and depletion of microfilarial worm loads. The two analogs delivered comparative or superior efficacy compared to a 3- to 4-week course of doxycycline or minocycline. A-1574083 (now called ABBV-4083) was selected for further preclinical testing. Cardiovascular studies in dogs and toxicology studies in rats and dogs revealed no adverse effects at doses (50 mg/kg) that achieved plasma concentrations >10-fold above the efficacious concentration. A-1574083 (ABBV-4083) shows potential as an anti-Wolbachia macrolide with an efficacy, pharmacology, and safety profile that is compatible with a short-term oral drug course for treating lymphatic filariasis and onchocerciasis.}, }
@article {pmid30865445, year = {2019}, author = {Carter, AC and Petersen, CL and Wendt, KL and Helff, SK and Risinger, AL and Mooberry, SL and Cichewicz, RH}, title = {In Situ Ring Contraction and Transformation of the Rhizoxin Macrocycle through an Abiotic Pathway.}, journal = {Journal of natural products}, volume = {82}, number = {4}, pages = {886-894}, doi = {10.1021/acs.jnatprod.8b00974}, pmid = {30865445}, issn = {1520-6025}, mesh = {Burkholderia/chemistry ; Cell Line, Tumor ; Drug Screening Assays, Antitumor ; Humans ; Macrocyclic Compounds/*chemistry/*pharmacokinetics ; Macrolides/*chemistry/*pharmacokinetics ; Molecular Structure ; Rhizopus/chemistry ; Sarcoma, Ewing/pathology ; *Stress, Physiological ; Structure-Activity Relationship ; Symbiosis ; }, abstract = {A Rhizopus sp. culture containing an endosymbiont partner (Burkholderia sp.) was obtained through a citizen-science-based soil-collection program. An extract prepared from the pair of organisms exhibited strong inhibition of Ewing sarcoma cells and was selected for bioassay-guided fractionation. This led to the purification of rhizoxin (1), a potent antimitotic agent that inhibited microtubule polymerization, along with several new (2-5) and known (6) analogues of 1. The structures of 2-6 were established using a combination of NMR data analysis, while the configurations of the new stereocenters were determined using ROESY spectroscopy and comparison of GIAO-derived and experimental data for NMR chemical shift and [3] JHH coupling values. Whereas compound 1 showed modest selectivity for Ewing sarcoma cell lines carrying the EWSR1/ FLI1 fusion gene, the other compounds were determined to be inactive. Chemically, compound 2 stands out from other rhizoxin analogues because it is the first member of this class that is reported to contain a one-carbon-smaller 15-membered macrolactone system. Through a combination of experimental and computational tests, we determined that 2 is likely formed via an acid-catalyzed Meinwald rearrangement from 1 because of the mild acidic culture environment created by the Rhizopus sp. isolate and its symbiont.}, }
@article {pmid30862902, year = {2019}, author = {Savage, C}, title = {Seabird nutrients are assimilated by corals and enhance coral growth rates.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {4284}, pmid = {30862902}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/*growth &amp; development/*metabolism ; Birds/*metabolism ; Nitrogen/metabolism ; Seaweed/metabolism ; }, abstract = {Nutrient subsidies across ecotone boundaries can enhance productivity in the recipient ecosystem, especially if the nutrients are transferred from a nutrient rich to an oligotrophic ecosystem. This study demonstrates that seabird nutrients from islands are assimilated by endosymbionts in corals on fringing reefs and enhance growth of a dominant reef-building species, Acropora formosa. Nitrogen stable isotope ratios (δ[15]N) of zooxanthellae were enriched in corals near seabird colonies and decreased linearly with distance from land, suggesting that ornithogenic nutrients were assimilated in corals. In a one-year reciprocal transplant experiment, A. formosa fragments grew up to four times faster near the seabird site than conspecifics grown without the influence of seabird nutrients. The corals influenced by elevated ornithogenic nutrients were located within a marine protected area with abundant herbivorous fish populations, which kept nuisance macroalgae to negligible levels despite high nutrient concentrations. In this pristine setting, seabird nutrients provide a beneficial nutrient subsidy that increases growth of the ecologically important branching corals. The findings highlight the importance of catchment-to-reef management, not only for ameliorating negative impacts from land but also to maintain beneficial nutrient subsidies, in this case seabird guano.}, }
@article {pmid30859201, year = {2019}, author = {Grisdale, CJ and Smith, DR and Archibald, JM}, title = {Relative Mutation Rates in Nucleomorph-Bearing Algae.}, journal = {Genome biology and evolution}, volume = {11}, number = {4}, pages = {1045-1053}, pmid = {30859201}, issn = {1759-6653}, mesh = {Biological Evolution ; Cryptophyta/*genetics ; *Genome, Mitochondrial ; *Genome, Plastid ; *Mutation Rate ; Symbiosis ; }, abstract = {Chlorarachniophyte and cryptophyte algae are unique among plastid-containing species in that they have a nucleomorph genome: a compact, highly reduced nuclear genome from a photosynthetic eukaryotic endosymbiont. Despite their independent origins, the nucleomorph genomes of these two lineages have similar genomic architectures, but little is known about the evolutionary pressures impacting nucleomorph DNA, particularly how their rates of evolution compare to those of the neighboring genetic compartments (the mitochondrion, plastid, and nucleus). Here, we use synonymous substitution rates to estimate relative mutation rates in the four genomes of nucleomorph-bearing algae. We show that the relative mutation rates of the host versus endosymbiont nuclear genomes are similar in both chlorarachniophytes and cryptophytes, despite the fact that nucleomorph gene sequences are notoriously highly divergent. There is some evidence, however, for slightly elevated mutation rates in the nucleomorph DNA of chlorarachniophytes-a feature not observed in that of cryptophytes. For both lineages, relative mutation rates in the plastid appear to be lower than those in the nucleus and nucleomorph (and, in one case, the mitochondrion), which is consistent with studies of other plastid-bearing protists. Given the divergent nature of nucleomorph genes, our finding of relatively low evolutionary rates in these genomes suggests that for both lineages a burst of evolutionary change and/or decreased selection pressures likely occurred early in the integration of the secondary endosymbiont.}, }
@article {pmid30857919, year = {2019}, author = {Brinker, P and Fontaine, MC and Beukeboom, LW and Falcao Salles, J}, title = {Host, Symbionts, and the Microbiome: The Missing Tripartite Interaction.}, journal = {Trends in microbiology}, volume = {27}, number = {6}, pages = {480-488}, doi = {10.1016/j.tim.2019.02.002}, pmid = {30857919}, issn = {1878-4380}, mesh = {Animals ; Environment ; *Host-Pathogen Interactions ; Humans ; Microbial Interactions ; *Microbiota ; *Symbiosis ; }, abstract = {Symbiosis between microbial associates and a host is a ubiquitous feature of life on earth, modulating host phenotypes. In addition to endosymbionts, organisms harbour a collection of host-associated microbes, the microbiome that can impact important host traits. In this opinion article we argue that the mutual influences of the microbiome and endosymbionts, as well as their combined influence on the host, are still understudied. Focusing on the endosymbiont Wolbachia, we present growing evidence indicating that host phenotypic effects are exerted in interaction with the remainder microbiome and the host. We thus advocate that only through an integrated approach that considers multiple interacting partners and environmental influences will we be able to gain a better understanding of host-microbe associations.}, }
@article {pmid30850675, year = {2019}, author = {Liu, XD and Lei, HX and Chen, FF}, title = {Infection pattern and negative effects of a facultative endosymbiont on its insect host are environment-dependent.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {4013}, pmid = {30850675}, issn = {2045-2322}, mesh = {Animals ; Aphids/*microbiology ; Enterobacteriaceae/genetics ; Enterobacteriaceae Infections/*microbiology ; Genotype ; Rickettsia/genetics ; Rickettsia Infections/microbiology ; Symbiosis/*physiology ; Temperature ; }, abstract = {Regiella insecticola is a bacterial endosymbiont in insects that exhibits a negative effect on the fitness of hosts. Thus, it is not clear why this costly endosymbiont can persist in host populations. Here, we tested a hypothesis that the infection pattern and negative roles of the endosymbiont were not constant but environmentally dependent. The grain aphids Sitobion avenae, belonging to different genotypes and infected with Regiella or not, were used in this study. We found that S. avenae populations were infected with Regiella, Hamiltonella defensa, Serratia symbiotica and Rickettsia. The predominant endosymbionts in the aphid populations varied with season. Serratia and Rickettsia were predominant from December to February while Regiella predominated from March to May. The vertical transmission of Regiella was poorer at high temperature, but following conditioning for seven generations, the transmission rate improved. Regiella inhibited the production of winged aphids at 25 °C, but it did not affect winged morph production at the higher temperatures of 28 °C and 31 °C. Regiella infection decreased the intrinsic rate of increase (rm) of aphids at 25 °C and 28 °C. However, at 31 °C, the effect of Regiella on the rm varied depending on the aphid genotype and density. Thus, the negative effects of this endosymbiont on its host were environmentally dependent.}, }
@article {pmid30850430, year = {2019}, author = {Pons, I and Renoz, F and Noël, C and Hance, T}, title = {New Insights into the Nature of Symbiotic Associations in Aphids: Infection Process, Biological Effects, and Transmission Mode of Cultivable Serratia symbiotica Bacteria.}, journal = {Applied and environmental microbiology}, volume = {85}, number = {10}, pages = {}, pmid = {30850430}, issn = {1098-5336}, mesh = {Animals ; Aphids/*microbiology ; Phylogeny ; Serratia/genetics/*physiology ; *Symbiosis ; }, abstract = {Symbiotic microorganisms are widespread in nature and can play a major role in the ecology and evolution of animals. The aphid-Serratia symbiotica bacterium interaction provides a valuable model to study the mechanisms behind these symbiotic associations. The recent discovery of cultivable S. symbiotica strains with a free-living lifestyle allowed us to simulate their environmental acquisition by aphids to examine the mechanisms involved in this infection pathway. Here, after oral ingestion, we analyzed the infection dynamics of cultivable S. symbiotica during the host's lifetime using quantitative PCR and fluorescence techniques and determined the immediate fitness consequences of these bacteria on their new host. We further examined the transmission behavior and phylogenetic position of cultivable strains. Our study revealed that cultivable S. symbiotica bacteria are predisposed to establish a symbiotic association with a new aphid host, settling in its gut. We show that cultivable S. symbiotica bacteria colonize the entire aphid digestive tract following infection, after which the bacteria multiply exponentially during aphid development. Our results further reveal that gut colonization by the bacteria induces a fitness cost to their hosts. Nevertheless, it appeared that the bacteria also offer an immediate protection against parasitoids. Interestingly, cultivable S. symbiotica strains seem to be extracellularly transmitted, possibly through the honeydew, while S. symbiotica is generally considered a maternally transmitted bacterium living within the aphid body cavity and bringing some benefits to its hosts, despite its costs. These findings provide new insights into the nature of symbiosis in aphids and the mechanisms underpinning these interactions.IMPORTANCES. symbiotica is one of the most common symbionts among aphid populations and includes a wide variety of strains whose degree of interdependence on the host may vary considerably. S. symbiotica strains with a free-living capacity have recently been isolated from aphids. By using these strains, we established artificial associations by simulating new bacterial acquisitions involved in aphid gut infections to decipher their infection processes and biological effects on their new hosts. Our results showed the early stages involved in this route of infection. So far, S. symbiotica has been considered a maternally transmitted aphid endosymbiont. Nevertheless, we show that our cultivable S. symbiotica strains occupy and replicate in the aphid gut and seem to be transmitted over generations through an environmental transmission mechanism. Moreover, cultivable S. symbiotica bacteria are both parasites and mutualists given the context, as are many aphid endosymbionts. Our findings give new perception of the associations involved in bacterial mutualism in aphids.}, }
@article {pmid30847086, year = {2019}, author = {Lin, D and Zhang, L and Shao, W and Li, X and Liu, X and Wu, H and Rao, Q}, title = {Phylogenetic analyses and characteristics of the microbiomes from five mealybugs (Hemiptera: Pseudococcidae).}, journal = {Ecology and evolution}, volume = {9}, number = {4}, pages = {1972-1984}, pmid = {30847086}, issn = {2045-7758}, abstract = {Associations between Sternorrhyncha insects and intracellular bacteria are common in nature. Mealybugs are destructive pests that seriously threaten the production of agriculture and forestry. Mealybugs have evolved intimate endosymbiotic relationships with bacteria, which provide them with essential amino acids, vitamins, and other nutrients. In this study, the divergence of five mealybugs was analyzed based up the sequences of the mitochondrial cytochrome oxidase I (mtCOI). Meanwhile, the distinct regions of the 16S rRNA gene of primary symbionts in the mealybugs were sequenced. Finally, high-throughput sequencing (HTS) techniques were used to study the microbial abundance and diversity in mealybugs. Molecular phylogenetic analyses revealed that these five mealybugs were subdivided into two different clusters. One cluster of mealybugs (Dysmicoccus neobrevipes, Pseudococcus comstocki, and Planococcus minor) harbored the primary endosymbiont "Candidatus Tremblaya princeps," and another cluster (Phenacoccus solenopsis and Phenacoccus solani) harbored "Ca. Tremblaya phenacola." The mtCOI sequence divergence between the two clusters was similar to the 16S rRNA sequence divergence between T. princeps and T. phenacola. Thus, we concluded that the symbiont phylogeny was largely concordant with the host phylogeny. The HTS showed that the microbial abundance and diversity within P. solani and P. solenopsis were highly similar, and there was lower overall species richness compared to the other mealybugs. Among the five mealybugs, we also found significant differences in Shannon diversity and observed species. These results provide a theoretical basis for further research on the coevolution of mealybugs and their symbiotic microorganisms. These findings are also useful for research on the effect of symbiont diversity on the pest status of mealybugs in agricultural systems.}, }
@article {pmid30844054, year = {2019}, author = {Thairu, MW and Hansen, AK}, title = {It's a small, small world: unravelling the role and evolution of small RNAs in organelle and endosymbiont genomes.}, journal = {FEMS microbiology letters}, volume = {366}, number = {5}, pages = {}, doi = {10.1093/femsle/fnz049}, pmid = {30844054}, issn = {1574-6968}, mesh = {Bacteria/*genetics ; Evolution, Molecular ; Gene Expression Regulation ; Genome/genetics ; Organelles/*genetics ; RNA, Bacterial/genetics/metabolism ; RNA, Small Untranslated/genetics/metabolism/*physiology ; Symbiosis/*genetics ; }, abstract = {Organelles and host-restricted bacterial symbionts are characterized by having highly reduced genomes that lack many key regulatory genes and elements. Thus, it has been hypothesized that the eukaryotic nuclear genome is primarily responsible for regulating these symbioses. However, with the discovery of organelle- and symbiont-expressed small RNAs (sRNAs) there is emerging evidence that these sRNAs may play a role in gene regulation as well. Here, we compare the diversity of organelle and bacterial symbiont sRNAs recently identified using genome-enabled '-omic' technologies and discuss their potential role in gene regulation. We also discuss how the genome architecture of small genomes may influence the evolution of these sRNAs and their potential function. Additionally, these new studies suggest that some sRNAs are conserved within organelle and symbiont taxa and respond to changes in the environment and/or their hosts. In summary, these results suggest that organelle and symbiont sRNAs may play a role in gene regulation in addition to nuclear-encoded host mechanisms.}, }
@article {pmid30834847, year = {2019}, author = {Zhang, J and Dai, Y and Fan, S and Zhang, K and Shuai, C and Bian, X and Hui, L and Wu, Z and Zhang, J and Guo, Z and Deng, F and Guo, M}, title = {Association between extrauterine growth restriction and changes of intestinal flora in Chinese preterm infants.}, journal = {Journal of developmental origins of health and disease}, volume = {10}, number = {5}, pages = {513-521}, doi = {10.1017/S2040174419000084}, pmid = {30834847}, issn = {2040-1752}, mesh = {Bacteria/*classification/genetics ; Birth Weight ; Feces/*microbiology ; Female ; Fetal Growth Retardation/*physiopathology ; *Gastrointestinal Microbiome ; Gestational Age ; Humans ; Infant ; Infant, Newborn ; Infant, Premature/*growth &amp; development ; Infant, Very Low Birth Weight/*growth &amp; development ; Intestines/*microbiology/pathology ; RNA, Ribosomal, 16S/genetics ; Risk Factors ; }, abstract = {The aim of the study was to investigate any association between extrauterine growth restriction (EUGR) and intestinal flora of <30-week-old preterm infants. A total of 59 preterm infants were assigned to EUGR (n=23) and non-EUGR (n=36) groups. Intestinal bacteria were compared by using high-throughput sequencing of bacterial rRNA. The total abundance of bacteria in 344 genera (7568 v. 13,760; P<0.0001) and 456 species (10,032 v. 18,240; P<0.0001) was significantly decreased in the EUGR group compared with the non-EUGR group. After application of a multivariate logistic model and adjusting for potential confounding factors, as well as false-discovery rate corrections, we found four bacterial genera with higher and one bacterial genus with lower abundance in the EUGR group compared with the control group. In addition, the EUGR group showed significantly increased abundances of six species (Streptococcus parasanguinis, Bacterium RB5FF6, two Klebsiella species and Microbacterium), but decreased frequencies of three species (one Acinetobacter species, Endosymbiont_of_Sphenophorus_lev and one Enterobacter_species) compared with the non-EUGR group. Taken together, there were significant changes in the intestinal microflora of preterm infants with EUGR compared to preterm infants without EUGR.}, }
@article {pmid30830691, year = {2019}, author = {Mareš, J and Johansen, JR and Hauer, T and Zima, J and Ventura, S and Cuzman, O and Tiribilli, B and Kaštovský, J}, title = {Taxonomic resolution of the genus Cyanothece (Chroococcales, Cyanobacteria), with a treatment on Gloeothece and three new genera, Crocosphaera, Rippkaea, and Zehria.}, journal = {Journal of phycology}, volume = {55}, number = {3}, pages = {578-610}, doi = {10.1111/jpy.12853}, pmid = {30830691}, issn = {1529-8817}, support = {RVO 6795939//Institute of Botany, Czech Academy of Sciences/International ; 15-11912S//Grantov&#xe1; Agentura &#x10c;esk&#xe9; Republiky/International ; }, mesh = {*Cyanobacteria ; *Cyanothece ; Nitrogen Fixation ; Oceans and Seas ; Phylogeny ; RNA, Ribosomal, 16S ; }, abstract = {The systematics of single-celled cyanobacteria represents a major challenge due to morphological convergence and application of various taxonomic concepts. The genus Cyanothece is one of the most problematic cases, as the name has been applied to oval-shaped coccoid cyanobacteria lacking sheaths with little regard to their phylogenetic position and details of morphology and ultrastructure. Hereby we analyze an extensive set of complementary genetic and phenotypic evidence to disentangle the relationships among these cyanobacteria. We provide diagnostic characters to separate the known genera Cyanothece, Gloeothece, and Aphanothece, and provide a valid description for Crocosphaera gen. nov. We describe two new genera, Rippkaea and Zehria, to characterize two distinct phylogenetic lineages outside the previously known genera. We further describe 13 new species in total including Cyanothece svehlovae, Gloeothece aequatorialis, G. aurea, G. bryophila, G. citriformis, G. reniformis, Gloeothece tonkinensis, G. verrucosa, Crocosphaera watsonii, C. subtropica, C. chwakensis, Rippkaea orientalis, and Zehria floridana to recognize the intrageneric diversity as rendered by polyphasic analysis. We discuss the close relationship of free-living cyanobacteria from the Crocosphaera lineage to nitrogen-fixing endosymbionts of marine algae. The current study includes several experimental strains (Crocosphaera and "Cyanothece") important for the study of diazotrophy and the global oceanic nitrogen cycle, and provides evidence suggesting ancestral N2 -fixing capability in the chroococcalean lineage.}, }
@article {pmid30826731, year = {2019}, author = {Koehler, L and Flemming, FE and Schrallhammer, M}, title = {Towards an ecological understanding of the killer trait - A reproducible protocol for testing its impact on freshwater ciliates.}, journal = {European journal of protistology}, volume = {68}, number = {}, pages = {108-120}, doi = {10.1016/j.ejop.2019.02.002}, pmid = {30826731}, issn = {1618-0429}, mesh = {Bacteria/*metabolism ; *Bacterial Physiological Phenomena ; Ciliophora/*microbiology/*physiology ; Fresh Water ; Paramecium/microbiology/physiology ; *Water Microbiology ; }, abstract = {Paramecium strains with the ability to kill other paramecia often harbour intracellular bacteria belonging to the genera Caedibacter or Caedimonas. Central structures of this killer trait are refractile bodies (R-bodies) produced by the endosymbionts. Once ingested by a sensitive Paramecium, R-bodies presumably act as delivery system for an unidentified toxin which causes the death of endosymbiont-free paramecia while those infected gain resistance from their symbionts. The killer trait is therefore considered as competitive advantage for the hosts of R-body producers. While its effectiveness against paramecia is well documented, the effects on other aquatic ciliates are much less studied. In order to address the broadness of the killer trait, a reproducible killer test assay considering the effects on predatory ciliates (Climacostomum virens and Dileptus jonesi) as well as potential bacterivorous Paramecium competitors (Dexiostoma campyla, Euplotes aediculatus, Euplotes woodruffi, and Spirostomum teres) as possibly susceptible species was established. All used organisms were molecularly characterized to increase traceability and reproducibility. The absence of any lethal effects in both predators and competitors after exposure to killer paramecia strongly suggests a narrow action range for the killer trait. Thus, R-body producing bacteria provide their host with a complex, costly strategy to outcompete symbiont-free congeners only.}, }
@article {pmid30823538, year = {2019}, author = {Gil, R and Latorre, A}, title = {Unity Makes Strength: A Review on Mutualistic Symbiosis in Representative Insect Clades.}, journal = {Life (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, pmid = {30823538}, issn = {2075-1729}, abstract = {Settled on the foundations laid by zoologists and embryologists more than a century ago, the study of symbiosis between prokaryotes and eukaryotes is an expanding field. In this review, we present several models of insect[-]bacteria symbioses that allow for the detangling of most known features of this distinctive way of living, using a combination of very diverse screening approaches, including molecular, microscopic, and genomic techniques. With the increasing the amount of endosymbiotic bacteria genomes available, it has been possible to develop evolutionary models explaining the changes undergone by these bacteria in their adaptation to the intracellular host environment. The establishment of a given symbiotic system can be a root cause of substantial changes in the partners' way of life. Furthermore, symbiont replacement and/or the establishment of bacterial consortia are two ways in which the host can exploit its interaction with environmental bacteria for endosymbiotic reinvigoration. The detailed study of diverse and complex symbiotic systems has revealed a great variety of possible final genomic products, frequently below the limit considered compatible with cellular life, and sometimes with unanticipated genomic and population characteristics, raising new questions that need to be addressed in the near future through a wider exploration of new models and empirical observations.}, }
@article {pmid30820826, year = {2019}, author = {Onder, Z and Ciloglu, A and Duzlu, O and Yildirim, A and Okur, M and Yetismis, G and Inci, A}, title = {Molecular detection and identification of Wolbachia endosymbiont in fleas (Insecta: Siphonaptera).}, journal = {Folia microbiologica}, volume = {64}, number = {6}, pages = {789-796}, pmid = {30820826}, issn = {1874-9356}, mesh = {Animals ; DNA, Bacterial/genetics ; Female ; Flea Infestations/epidemiology/parasitology/*veterinary ; Genes, Bacterial/genetics ; Genetic Variation ; Genome, Bacterial/genetics ; Host Specificity ; Male ; Phylogeny ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Siphonaptera/*microbiology ; Symbiosis ; Turkey/epidemiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {The aim of this study was to determine the presence and prevalence of Wolbachia bacteria in natural population of fleas (Insecta: Siphonaptera) in Turkey, and to exhibit the molecular characterization and the phylogenetic reconstruction at the positive isolates with other species in GenBank, based on 16S rDNA sequences. One hundred twenty-four flea samples belonging to the species Ctenocephalides canis, C. felis, and Pulex irritans were collected from animal shelters in Kayseri between January and August 2017. All flea species were individually screened for the presence of Wolbachia spp. by polymerase chain reaction (PCR) targeting the 16S ribosomal RNA gene. According to PCR analyses, Wolbachia spp. were found prevalent in C. canis and P. irritans fleas, while it was not detected in the C. felis species. Totally, 20 isolates were purified from agarose gel and sequenced with the same primers for molecular characterization and phylogenetic analyses. The sequence analyses revealed 17 polymorphic sites and 2 genetically different Wolbachia isolates, representing two different haplotypes in two flea species. The distribution patterns, molecular characterization, and phylogenetic status of Wolbachia spp. of fleas in Turkey are presented for the first time with this study. Understanding of the role of Wolbachia in vector biology may provide information for developing Wolbachia-based biological control tools.}, }
@article {pmid30819893, year = {2019}, author = {Maire, J and Vincent-Monégat, C and Balmand, S and Vallier, A and Hervé, M and Masson, F and Parisot, N and Vigneron, A and Anselme, C and Perrin, J and Orlans, J and Rahioui, I and Da Silva, P and Fauvarque, MO and Mengin-Lecreulx, D and Zaidman-Rémy, A and Heddi, A}, title = {Weevil pgrp-lb prevents endosymbiont TCT dissemination and chronic host systemic immune activation.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {12}, pages = {5623-5632}, pmid = {30819893}, issn = {1091-6490}, mesh = {Animals ; Bacteria/immunology/metabolism ; Carrier Proteins/immunology/*physiology ; Cytotoxins ; Host Microbial Interactions/*immunology/physiology ; Insect Proteins/genetics ; Larva/metabolism ; Peptidoglycan/immunology/metabolism ; Protein Isoforms ; Symbiosis/*immunology ; Weevils/genetics/metabolism ; }, abstract = {Long-term intracellular symbiosis (or endosymbiosis) is widely distributed across invertebrates and is recognized as a major driving force in evolution. However, the maintenance of immune homeostasis in organisms chronically infected with mutualistic bacteria is a challenging task, and little is known about the molecular processes that limit endosymbiont immunogenicity and host inflammation. Here, we investigated peptidoglycan recognition protein (PGRP)-encoding genes in the cereal weevil Sitophilus zeamais's association with Sodalis pierantonius endosymbiont. We discovered that weevil pgrp-lb generates three transcripts via alternative splicing and differential regulation. A secreted isoform is expressed in insect tissues under pathogenic conditions through activation of the PGRP-LC receptor of the immune deficiency pathway. In addition, cytosolic and transmembrane isoforms are permanently produced within endosymbiont-bearing organ, the bacteriome, in a PGRP-LC-independent manner. Bacteriome isoforms specifically cleave the tracheal cytotoxin (TCT), a peptidoglycan monomer released by endosymbionts. pgrp-lb silencing by RNAi results in TCT escape from the bacteriome to other insect tissues, where it chronically activates the host systemic immunity through PGRP-LC. While such immune deregulations did not impact endosymbiont load, they did negatively affect host physiology, as attested by a diminished sexual maturation of adult weevils. Whereas pgrp-lb was first described in pathogenic interactions, this work shows that, in an endosymbiosis context, specific bacteriome isoforms have evolved, allowing endosymbiont TCT scavenging and preventing chronic endosymbiont-induced immune responses, thus promoting host homeostasis.}, }
@article {pmid30813886, year = {2019}, author = {Bykov, R&#x410; and Yudina, MA and Gruntenko, NE and Zakharov, IK and Voloshina, MA and Melashchenko, ES and Danilova, MV and Mazunin, IO and Ilinsky, YY}, title = {Prevalence and genetic diversity of Wolbachia endosymbiont and mtDNA in Palearctic populations of Drosophila melanogaster.}, journal = {BMC evolutionary biology}, volume = {19}, number = {Suppl 1}, pages = {48}, pmid = {30813886}, issn = {1471-2148}, support = {F32 MH010832/MH/NIMH NIH HHS/United States ; }, mesh = {Animals ; DNA, Mitochondrial/*genetics ; Drosophila melanogaster/*microbiology ; *Genetic Variation ; Genomics ; Geography ; Haplotypes ; Mitochondria/genetics ; Prevalence ; *Symbiosis ; Wolbachia/cytology/*genetics/*physiology ; }, abstract = {BACKGROUND: Maternally inherited Wolbachia symbionts infect D. melanogaster populations worldwide. Infection rates vary greatly. Genetic diversity of Wolbachia in D. melanogaster can be subdivided into several closely related genotypes coinherited with certain mtDNA lineages. mtDNA haplotypes have the following global distribution pattern: mtDNA clade I is mostly found in North America, II and IV in Africa, III in Europe and Africa, V in Eurasia, VI is global but very rare, and VIII is found in Asia. The wMel Wolbachia genotype is predominant in D. melanogaster populations. However, according to the hypothesis of global Wolbachia replacement, the wMelCS genotype was predominant before the XX century when it was replaced by the wMel genotype. Here we analyse over 1500 fly isolates from the Palearctic region to evaluate the prevalence, genetic diversity and distribution pattrern of the Wolbachia symbiont, occurrence of mtDNA variants, and finally to discuss the Wolbachia genotype global replacement hypothesis.<br><br>RESULTS: All studied Palearctic populations of D. melanogaster were infected with Wolbachia at a rate of 33-100%. We did not observe any significant correlation between infection rate and longitude or latitude. Five previously reported Wolbachia genotypes were found in Palearctic populations with a predominance of the wMel variant. The mtDNA haplotypes of the I_II_III clade and V clade were prevalent in Palearctic populations. To test the recent Wolbachia genotype replacement hypothesis, we examined three genomic regions of CS-like genotypes. Low genetic diversity was observed, only two haplotypes of the CS genotypes with a 'CCG' variant predominance were found.<br><br>CONCLUSION: The results of our survey of Wolbachia infection prevalence and genotype diversity in Palearctic D. melanogaster populations confirm previous studies. Wolbachia is ubiquitous in the Palearctic region. The wMel genotype is dominant with local occurrence of rare genotypes. Together with variants of the V mtDNA clade, the variants of the 'III+' clade are dominant in both infected and uninfected flies of Palearctic populations. Based on our data on Wolbachia and mtDNA in different years in some Palearctic localities, we can conclude that flies that survive the winter make the predominant symbiont contribution to the subsequent generation. A comprehensive overview of mtDNA and Wolbachia infection of D. melanogaster populations worldwide does not support the recent global Wolbachia genotype replacement hypothesis. However, we cannot exclude wMelCS genotype rate fluctuations in the past.}, }
@article {pmid30806054, year = {2019}, author = {Du, J and Jiang, S and Wei, J and Shen, Y and Ni, J}, title = {[Co-expression of lignocellulase from termite and their endosymbionts].}, journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology}, volume = {35}, number = {2}, pages = {244-253}, doi = {10.13345/j.cjb.180235}, pmid = {30806054}, issn = {1872-2075}, mesh = {Animals ; Cellulase ; Cellulose ; Hydrolysis ; *Isoptera ; Lignin ; Symbiosis ; beta-Glucosidase ; }, abstract = {Natural lignocellulosic materials contain cellulose, hemicellulose, and lignin. Cellulose hydrolysis to glucose requires a series of lignocellulases. Recently, the research on the synergistic effect of lignocellulases has become a new research focus. Here, four lignocellulase genes encoding β-glucosidase, endo-1,4-β-glucanase, xylanase and laccase from termite and their endosymbionts were cloned into pETDuet-1 and pRSFDuet-1 and expressed in Escherichia coli. After SDS-PAGE analysis, the corresponding protein bands consistent with the theoretical values were observed and all the proteins showed enzyme activities. We used phosphoric acid swollen cellulose (PASC) as substrate to measure the synergistic effect of crude extracts of co-expressing enzymes and the mixture of single enzyme. The co-expressed enzymes increased the degradation efficiency of PASC by 44% compared with the single enzyme mixture; while the degradation rate increased by 34% and 20%, respectively when using filter paper and corn cob pretreated with phosphoric acid as substrates. The degradation efficiency of the co-expressed enzymes was higher than the total efficiency of the single enzyme mixture.}, }
@article {pmid30805132, year = {2019}, author = {Gardner, SG and Camp, EF and Smith, DJ and Kahlke, T and Osman, EO and Gendron, G and Hume, BCC and Pogoreutz, C and Voolstra, CR and Suggett, DJ}, title = {Coral microbiome diversity reflects mass coral bleaching susceptibility during the 2016 El Niño heat wave.}, journal = {Ecology and evolution}, volume = {9}, number = {3}, pages = {938-956}, pmid = {30805132}, issn = {2045-7758}, abstract = {Repeat marine heat wave-induced mass coral bleaching has decimated reefs in Seychelles for 35 years, but how coral-associated microbial diversity (microalgal endosymbionts of the family Symbiodiniaceae and bacterial communities) potentially underpins broad-scale bleaching dynamics remains unknown. We assessed microbiome composition during the 2016 heat wave peak at two contrasting reef sites (clear vs. turbid) in Seychelles, for key coral species considered bleaching sensitive (Acropora muricata, Acropora gemmifera) or tolerant (Porites lutea, Coelastrea aspera). For all species and sites, we sampled bleached versus unbleached colonies to examine how microbiomes align with heat stress susceptibility. Over 30% of all corals bleached in 2016, half of which were from Acropora sp. and Pocillopora sp. mass bleaching that largely transitioned to mortality by 2017. Symbiodiniaceae ITS2-sequencing revealed that the two Acropora sp. and P. lutea generally associated with C3z/C3 and C15 types, respectively, whereas C. aspera exhibited a plastic association with multiple D types and two C3z types. 16S rRNA gene sequencing revealed that bacterial communities were coral host-specific, largely through differences in the most abundant families, Hahellaceae (comprising Endozoicomonas), Rhodospirillaceae, and Rhodobacteraceae. Both Acropora sp. exhibited lower bacterial diversity, species richness, and community evenness compared to more bleaching-resistant P. lutea and C. aspera. Different bleaching susceptibility among coral species was thus consistent with distinct microbiome community profiles. These profiles were conserved across bleached and unbleached colonies of all coral species. As this pattern could also reflect a parallel response of the microbiome to environmental changes, the detailed functional associations will need to be determined in future studies. Further understanding such microbiome-environmental interactions is likely critical to target more effective management within oceanically isolated reefs of Seychelles.}, }
@article {pmid30798391, year = {2019}, author = {Singhal, K and Mohanty, S}, title = {Genome organisation and comparative genomics of four novel Wolbachia genome assemblies from Indian Drosophila host.}, journal = {Functional &amp; integrative genomics}, volume = {19}, number = {4}, pages = {617-632}, pmid = {30798391}, issn = {1438-7948}, mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Drosophila/microbiology ; *Genome, Bacterial ; Host-Pathogen Interactions ; *Polymorphism, Genetic ; Symbiosis ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Wolbachia has long been known to share an endosymbiotic relationship with its host as an obligate intracellular organism. Wolbachia diversity as different supergroups is found to be host-specific in most cases except a few, where the host species is seen to accommodate multiple strains. Besides, the Wolbachia genome must have undergone several changes in response to the evolving host genome in order to adapt and establish a strong association with its host, thus making a distinctive Wolbachia-host alliance. The present study focusses on four novel genome assembly and genome-wide sequence variations of Indian Wolbachia strains, i.e. wMel and wRi isolated from two different Drosophila hosts. The genome assembly has an average size of ~ 1.1 Mb and contains ~ 1100 genes, which is comparable with the previously sequenced Wolbachia genomes. The comparative genomics analysis of these genomes and sequence-wide comparison of some functionally significant genes, i.e. ankyrin repeats, Wsp and T4SS, highlight their sequence similarities and dissimilarities, further supporting the strain-specific association of Wolbachia to its host. Interestingly, some of the sequence variations are also found to be restricted to only Indian Wolbachia strains. Further analysis of prophage and their flanking regions in the Wolbachia genome reveals the presence of several functional genes which may assist the phage to reside inside the bacterial host, thus providing a trade-off for the endosymbiont-host association. Understanding this endosymbiont genome in different eco-geographical conditions has become imperative for the recent use of Wolbachia in medical entomology as a vector-control agent.}, }
@article {pmid30796245, year = {2019}, author = {Lhee, D and Ha, JS and Kim, S and Park, MG and Bhattacharya, D and Yoon, HS}, title = {Evolutionary dynamics of the chromatophore genome in three photosynthetic Paulinella species.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {2560}, pmid = {30796245}, issn = {2045-2322}, mesh = {Amoeba/*genetics ; *Chromatophores ; *Evolution, Molecular ; *Genome, Protozoan ; Symbiosis/*genetics ; }, abstract = {The thecate amoeba Paulinella is a valuable model for understanding plastid organellogenesis because this lineage has independently gained plastids (termed chromatophores) of alpha-cyanobacterial provenance. Plastid primary endosymbiosis in Paulinella occurred relatively recently (90-140 million years ago, Mya), whereas the origin of the canonical Archaeplastida plastid occurred >1,500 Mya. Therefore, these two events provide independent perspectives on plastid formation on vastly different timescales. Here we generated the complete chromatophore genome sequence from P. longichromatophora (979,356 bp, GC-content = 38.8%, 915 predicted genes) and P. micropora NZ27 (977,190 bp, GC-content = 39.9%, 911 predicted genes) and compared these data to that from existing chromatophore genomes. Our analysis suggests that when a basal split occurred among photosynthetic Paulinella species ca. 60 Mya, only 35% of the ancestral orthologous gene families from the cyanobacterial endosymbiont remained in chromatophore DNA. Following major gene losses during the early stages of endosymbiosis, this process slowed down significantly, resulting in a conserved gene content across extant taxa. Chromatophore genes faced relaxed selection when compared to homologs in free-living alpha-cyanobacteria, likely reflecting the homogeneous intracellular environment of the Paulinella host. Comparison of nucleotide substitution and insertion/deletion events among different P. micropora strains demonstrates that increases in AT-content and genome reduction are ongoing and dynamic processes in chromatophore evolution.}, }
@article {pmid30792089, year = {2019}, author = {Morozov, AA and Galachyants, YP}, title = {Diatom genes originating from red and green algae: Implications for the secondary endosymbiosis models.}, journal = {Marine genomics}, volume = {45}, number = {}, pages = {72-78}, doi = {10.1016/j.margen.2019.02.003}, pmid = {30792089}, issn = {1876-7478}, mesh = {Algal Proteins/analysis ; Chlorophyta/*genetics ; Diatoms/*genetics ; *Evolution, Molecular ; *Genome ; Phylogeny ; Rhodophyta/*genetics ; Symbiosis/*genetics ; }, abstract = {Previous phylogenomic analyses of diatoms have discovered some plastid-targeted genes apparently coming from green algae. Number of these genes varied from less than a half of EGT-compatible genes to an overwhelming majority, and their presence was treated as an evidence of cryptic green plastid. We have performed such an analysis with a novel weighted approach on an extended dataset of diatom genomes and proteomes. Approximately equal evidence was found for red and green algal origins for diatoms genes. Considering that very similar results were obtained on other secondary photosynthetic groups whose endosymbioses were independent from that of the diatom ancestors, we consider the serial plastid replacements unparsimonious. A better explanation of these data can be provided by the shopping bag model, where a future host switches numerous endosymbionts and acquires some genes from each of them. Eventually the host loses the ability to replace endosymbionts (e.g. through the loss of phagotrophy) and whatever symbiont was present at the moment gets fixed and reduced to an organelle.}, }
@article {pmid30786854, year = {2019}, author = {Garcia-Arraez, MG and Masson, F and Escobar, JCP and Lemaitre, B}, title = {Functional analysis of RIP toxins from the Drosophila endosymbiont Spiroplasma poulsonii.}, journal = {BMC microbiology}, volume = {19}, number = {1}, pages = {46}, pmid = {30786854}, issn = {1471-2180}, support = {339970/ERC_/European Research Council/International ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Bacterial Toxins/*genetics/metabolism ; Drosophila melanogaster/*microbiology ; Embryo, Nonmammalian/microbiology ; Female ; Hemocytes ; Hemolymph/microbiology ; *Host Microbial Interactions ; Longevity ; Male ; Ribosome Inactivating Proteins/*genetics/metabolism ; Spiroplasma/*chemistry/metabolism ; *Symbiosis ; }, abstract = {BACKGROUND: Insects frequently live in close relationship with symbiotic bacteria that carry out beneficial functions for their host, like protection against parasites and viruses. However, in some cases, the mutualistic nature of such associations is put into question because of detrimental phenotypes caused by the symbiont. One example is the association between the vertically transmitted facultative endosymbiont Spiroplasma poulsonii and its natural host Drosophila melanogaster. Whereas S. poulsonii protects its host against parasitoid wasps and nematodes by the action of toxins from the family of Ribosome Inactivating Proteins (RIPs), the presence of S. poulsonii has been reported to reduce host's life span and to kill male embryos by a toxin called Spaid. In this work, we investigate the harmful effects of Spiroplasma RIPs on Drosophila in the absence of parasite infection.<br><br>RESULTS: We show that only two Spiroplasma RIPs (SpRIP1 and SpRIP2) among the five RIP genes encoded in the S. poulsonii genome are significantly expressed during the whole Drosophila life cycle. Heterologous expression of SpRIP1 and 2 in uninfected flies confirms their toxicity, as indicated by a reduction of Drosophila lifespan and hemocyte number. We also show that RIPs can cause the death of some embryos, including females.<br><br>CONCLUSION: Our results indicate that RIPs released by S. poulsonii contribute to the reduction of host lifespan and embryo mortality. This suggests that SpRIPs may impact the insect-symbiont homeostasis beyond their protective function against parasites.}, }
@article {pmid30779681, year = {2019}, author = {Thu, MJ and Qiu, Y and Kataoka-Nakamura, C and Sugimoto, C and Katakura, K and Isoda, N and Nakao, R}, title = {Isolation of Rickettsia, Rickettsiella, and Spiroplasma from Questing Ticks in Japan Using Arthropod Cells.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {19}, number = {7}, pages = {474-485}, doi = {10.1089/vbz.2018.2373}, pmid = {30779681}, issn = {1557-7759}, mesh = {Aedes ; Animals ; Cell Line ; Coxiellaceae/genetics/*isolation &amp; purification ; DNA, Bacterial ; Ixodes ; Japan ; Polymerase Chain Reaction ; Rickettsia/genetics/*isolation &amp; purification ; Spiroplasma/genetics/*isolation &amp; purification ; Symbiosis ; Ticks/*microbiology ; }, abstract = {Ticks are blood-sucking ectoparasites that transmit zoonotic pathogens to humans and animals. Ticks harbor not only pathogenic microorganisms but also endosymbionts. Although some tick endosymbionts are known to be essential for the survival of ticks, their roles in ticks remain poorly understood. The main aim of this study was to isolate and characterize tick-borne microorganisms from field-collected ticks using two arthropod cell lines derived from Ixodes scapularis embryos (ISE6) and Aedes albopictus larvae (C6/36). A total of 170 tick homogenates originating from 15 different tick species collected in Japan were inoculated into each cell line. Bacterial growth was confirmed by PCR amplification of 16S ribosomal DNA (rDNA) of eubacteria. During the 8-week observation period, bacterial isolation was confirmed in 14 and 4 samples using ISE6 and C6/36 cells, respectively. The sequencing analysis of the 16S rDNA PCR products indicated that they were previously known tick-borne pathogens/endosymbionts in three different genera: Rickettsia, Rickettsiella, and Spiroplasma. These included four previously validated rickettsial species namely Rickettsia asiatica (n = 2), Rickettsia helvetica (n = 3), Rickettsia monacensis (n = 2), and Rickettsia tamurae (n = 3) and one uncharacterized genotype Rickettsia sp. LON (n = 2). Four isolates of Spiroplasma had the highest similarity with previously reported Spiroplasma isolates: Spiroplasma ixodetis obtained from ticks in North America and Spiroplasma sp. Bratislava 1 obtained from Ixodes ricinus in Europe, while two isolates of Rickettsiella showed 100% identity with Rickettsiella sp. detected from Ixodes uriae at Grimsey Island in Iceland. To the best of our knowledge, this is the first report on successful isolation of Rickettsiella from ticks. The isolates obtained in this study can be further analyzed to evaluate their pathogenic potential in animals and their roles as symbionts in ticks.}, }
@article {pmid30765418, year = {2019}, author = {Yamashita, T and Rhoads, DD and Pummill, J}, title = {Genome Analyses of a New Mycoplasma Species from the Scorpion Centruroides vittatus.}, journal = {G3 (Bethesda, Md.)}, volume = {9}, number = {4}, pages = {993-997}, pmid = {30765418}, issn = {2160-1836}, support = {P20 GM103429/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Base Composition ; DNA, Bacterial/chemistry ; *Genome, Bacterial ; Mycoplasma/classification/*genetics ; Phylogeny ; Scorpions/*microbiology ; Symbiosis ; Whole Genome Sequencing ; }, abstract = {Arthropod Mycoplasma are little known endosymbionts in insects, primarily known as plant disease vectors. Mycoplasma in other arthropods such as arachnids are unknown. We report the first complete Mycoplasma genome sequenced, identified, and annotated from a scorpion, Centruroides vittatus, and designate it as Mycoplasma vittatus We find the genome is at least a 683,827 bp single circular chromosome with a GC content of 42.7% and with 987 protein-coding genes. The putative virulence determinants include 11 genes associated with the virulence operon associated with protein synthesis or DNA transcription and ten genes with antibiotic and toxic compound resistance. Comparative analysis revealed that the M. vittatus genome is smaller than other Mycoplasma genomes and exhibits a higher GC content. Phylogenetic analysis shows M. vittatus as part of the Hominis group of Mycoplasma As arthropod genomes accumulate, further novel Mycoplasma genomes may be identified and characterized.}, }
@article {pmid30762095, year = {2019}, author = {Martínez-Rodríguez, P and Rolán-Alvarez, E and Del Mar Pérez-Ruiz, M and Arroyo-Yebras, F and Carpena-Catoira, C and Carvajal-Rodríguez, A and Bella, JL}, title = {Geographic and Temporal Variation of Distinct Intracellular Endosymbiont Strains of Wolbachia sp. in the Grasshopper Chorthippus parallelus: a Frequency-Dependent Mechanism?.}, journal = {Microbial ecology}, volume = {77}, number = {4}, pages = {1036-1047}, pmid = {30762095}, issn = {1432-184X}, mesh = {Animals ; Biological Coevolution ; Computer Simulation ; Geography ; Grasshoppers/*microbiology ; Linear Models ; *Polymorphism, Genetic ; Seasons ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia is an intracellular endosymbiont that can produce a range of effects on host fitness, but the temporal dynamics of Wolbachia strains have rarely been experimentally evaluated. We compare interannual strain frequencies along a geographical region for understanding the forces that shape Wolbachia strain frequency in natural populations of its host, Chorthippus parallelus (Orthoptera, Acrididae). General linear models show that strain frequency changes significantly across geographical and temporal scales. Computer simulation allows to reject the compatibility of the observed patterns with either genetic drift or sampling errors. We use consecutive years to estimate total Wolbachia strain fitness. Our estimation of Wolbachia fitness is significant in most cases, within locality and between consecutive years, following a negatively frequency-dependent trend. Wolbachia spp. B and F strains show a temporal pattern of variation that is compatible with a negative frequency-dependent natural selection mechanism. Our results suggest that such a mechanism should be at least considered in future experimental and theoretical research strategies that attempt to understand Wolbachia biodiversity.}, }
@article {pmid30744948, year = {2019}, author = {Binetruy, F and Bailly, X and Chevillon, C and Martin, OY and Bernasconi, MV and Duron, O}, title = {Phylogenetics of the Spiroplasma ixodetis endosymbiont reveals past transfers between ticks and other arthropods.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {3}, pages = {575-584}, doi = {10.1016/j.ttbdis.2019.02.001}, pmid = {30744948}, issn = {1877-9603}, mesh = {Animals ; Arthropods/*microbiology ; Bacterial Typing Techniques ; Disease Transmission, Infectious ; Female ; Genetic Variation ; Gram-Negative Bacterial Infections/*transmission ; Infectious Disease Transmission, Vertical ; Male ; Multilocus Sequence Typing ; *Phylogeny ; Spiroplasma/classification/*genetics ; *Symbiosis ; Ticks/*microbiology ; }, abstract = {The bacterium Spiroplasma ixodetis is a maternally inherited endosymbiont primarily described from ticks but also found widespread across other arthropods. While it has been identified as a male-killing agent in some insect species, the consequences of infection with S. ixodetis in ticks are entirely unknown, and it is unclear how this endosymbiont spreads across tick species. Here, we have investigated this aspect through the examination of the diversity and evolutionary history of S. ixodetis infections in 12 tick species and 12 other arthropod species. Using a multi-locus typing approach, we identified that ticks harbor a substantial diversity of divergent S. ixodetis strains. Phylogenetic investigations revealed that these S. ixodetis strains do not cluster within a tick-specific subclade but rather exhibit distinct evolutionary origins. In their past, these strains have undergone repeated horizontal transfers between ticks and other arthropods, including aphids and flies. This diversity pattern strongly suggests that maternal inheritance and horizontal transfers are key drivers of S. ixodetis spread, dictating global incidence of infections across tick communities. We do not, however, detect evidence of S. ixodetis-based male-killing since we observed that infections were widely present in both males and females across populations of the African blue tick Rhipicephalus decoloratus.}, }
@article {pmid30744707, year = {2019}, author = {Augustinos, AA and Moraiti, CA and Drosopoulou, E and Kounatidis, I and Mavragani-Tsipidou, P and Bourtzis, K and Papadopoulos, NT}, title = {Old residents and new arrivals of Rhagoletis species in Europe.}, journal = {Bulletin of entomological research}, volume = {109}, number = {6}, pages = {701-712}, doi = {10.1017/S0007485319000063}, pmid = {30744707}, issn = {1475-2670}, mesh = {Animals ; Europe ; Insect Control/methods ; Introduced Species ; Population Dynamics ; Tephritidae/*classification/genetics/microbiology ; Wolbachia/physiology ; }, abstract = {The genus Rhagoletis (Diptera: Tephritidae) comprises more than 65 species distributed throughout Europe, Asia and America, including many species of high economic importance. Currently, there are three Rhagoletis species that infest fruits and nuts in Europe. The European cherry fruit fly, Rhagoletis cerasi (may have invaded Europe a long time ago from the Caucasian area of West Asia), and two invasive species (recently introduced from North America): the eastern American cherry fruit fly, R. cingulata, and the walnut husk fly, R. completa. The presence of different Rhagoletis species may enhance population dynamics and establish an unpredictable economic risk for several fruit and nut crops in Europe. Despite their excessive economic importance, little is known on population dynamics, genetics and symbiotic associations for making sound pest control decisions in terms of species-specific, environmental friendly pest control methods. To this end, the current paper (a) summarizes recently accumulated genetic and population data for the European Rhagoletis species and their association with the endosymbiont Wolbachia pipientis, and (b) explores the possibility of using the current knowledge for implementing the innovative biological control methods of sterile insect technique and incompatible insect technique.}, }
@article {pmid30740457, year = {2019}, author = {Gruber, A}, title = {What's in a name? How organelles of endosymbiotic origin can be distinguished from endosymbionts.}, journal = {Microbial cell (Graz, Austria)}, volume = {6}, number = {2}, pages = {123-133}, pmid = {30740457}, issn = {2311-2638}, abstract = {Mitochondria and plastids evolved from free-living bacteria, but are now considered integral parts of the eukaryotic species in which they live. Therefore, they are implicitly called by the same eukaryotic species name. Historically, mitochondria and plastids were known as "organelles", even before their bacterial origin became fully established. However, since organelle evolution by endosymbiosis has become an established theory in biology, more and more endosymbiotic systems have been discovered that show various levels of host/symbiont integration. In this context, the distinction between "host/symbiont" and "eukaryote/organelle" systems is currently unclear. The criteria that are commonly considered are genetic integration (via gene transfer from the endosymbiont to the nucleus), cellular integration (synchronization of the cell cycles), and metabolic integration (the mutual dependency of the metabolisms). Here, I suggest that these criteria should be evaluated according to the resulting coupling of genetic recombination between individuals and congruence of effective population sizes, which determines if independent speciation is possible for either of the partners. I would like to call this aspect of integration "sexual symbiont integration". If the partners lose their independence in speciation, I think that they should be considered one species. The partner who maintains its genetic recombination mechanisms and life cycle should then be the name giving "host"; the other one would be the organelle. Distinguishing between organelles and symbionts according to their sexual symbiont integration is independent of any particular mechanism or structural property of the endosymbiont/host system under investigation.}, }
@article {pmid30733451, year = {2019}, author = {Vujanovic, V and Kim, SH and Lahlali, R and Karunakaran, C}, title = {Spectroscopy and SEM imaging reveal endosymbiont-dependent components changes in germinating kernel through direct and indirect coleorhiza-fungus interactions under stress.}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {1665}, pmid = {30733451}, issn = {2045-2322}, support = {//CIHR/Canada ; }, mesh = {Disease Resistance ; Fungi/*physiology ; Germination ; Host-Pathogen Interactions/*immunology ; Microscopy, Electron, Scanning/methods ; Plant Diseases/*immunology/microbiology ; Seeds/*anatomy &amp; histology/growth &amp; development/microbiology ; Spectroscopy, Fourier Transform Infrared/methods ; *Stress, Physiological ; *Symbiosis ; Triticum/*anatomy &amp; histology/growth &amp; development/microbiology ; }, abstract = {In the present study, FTIR spectroscopy and hyperspectral imaging was introduced as a non-destructive, sensitive-reliable tool for assessing the tripartite kernel-fungal endophyte environment interaction. Composition of coleorhizae of Triticum durum was studied under ambient and drought stress conditions. The OH-stretch IR absorption spectrum suggests that the water-deficit was possibly improved or moderated by kernel's endophytic partner. The OH-stretch frequency pattern coincides with other (growth and stress) related molecular changes. Analysis of lipid (3100-2800 cm[-1]) and protein (1700-1550 cm[-1]) regions seems to demonstrate that drought has a positive impact on lipids. The fungal endosymbiont direct contact with kernel during germination had highest effect on both lipid and protein (Amide I and II) groups, indicating an increased stress resistance in inoculated kernel. Compared to the indirect kernel-fungus interaction and to non-treated kernels (control), direct interaction produced highest effect on lipids. Among treatments, the fingerprint region (1800-800 cm[-1]) and SEM images indicated an important shift in glucose oligosaccharides, possibly linked to coleorhiza-polymer layer disappearance. Acquired differentiation in coleorhiza composition of T. durum, between ambient and drought conditions, suggests that FTIR spectroscopy could be a promising tool for studying endosymbiont-plant interactions within a changing environment.}, }
@article {pmid30727958, year = {2019}, author = {Kampfraath, AA and Klasson, L and Anvar, SY and Vossen, RHAM and Roelofs, D and Kraaijeveld, K and Ellers, J}, title = {Genome expansion of an obligate parthenogenesis-associated Wolbachia poses an exception to the symbiont reduction model.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {106}, pmid = {30727958}, issn = {1471-2164}, mesh = {Animals ; Arthropods/*microbiology/physiology ; DNA Repair ; Evolution, Molecular ; *Gene Transfer, Horizontal ; *Genome, Bacterial ; *Parthenogenesis ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*genetics/physiology ; }, abstract = {BACKGROUND: Theory predicts that dependency within host-endosymbiont interactions results in endosymbiont genome size reduction. Unexpectedly, the largest Wolbachia genome was found in the obligate, parthenogenesis-associated wFol. In this study, we investigate possible processes underlying this genome expansion by comparing a re-annotated wFol genome to other Wolbachia genomes. In addition, we also search for candidate genes related to parthenogenesis induction (PI).<br><br>RESULTS: Within wFol, we found five phage WO regions representing 25.4% of the complete genome, few pseudogenized genes, and an expansion of DNA-repair genes in comparison to other Wolbachia. These signs of genome conservation were mirrored in the wFol host, the springtail F. candida, which also had an expanded DNA-repair gene family and many horizontally transferred genes. Across all Wolbachia genomes, there was a strong correlation between gene numbers of Wolbachia strains and their hosts. In order to identify genes with a potential link to PI, we assembled the genome of an additional PI strain, wLcla. Comparisons between four PI Wolbachia, including wFol and wLcla, and fourteen non-PI Wolbachia yielded a small set of potential candidate genes for further investigation.<br><br>CONCLUSIONS: The strong similarities in genome content of wFol and its host, as well as the correlation between host and Wolbachia gene numbers suggest that there may be some form of convergent evolution between endosymbiont and host genomes. If such convergent evolution would be strong enough to overcome the evolutionary forces causing genome reduction, it would enable expanded genomes within long-term obligate endosymbionts.}, }
@article {pmid30727955, year = {2019}, author = {Détrée, C and Haddad, I and Demey-Thomas, E and Vinh, J and Lallier, FH and Tanguy, A and Mary, J}, title = {Global host molecular perturbations upon in situ loss of bacterial endosymbionts in the deep-sea mussel Bathymodiolus azoricus assessed using proteomics and transcriptomics.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {109}, pmid = {30727955}, issn = {1471-2164}, mesh = {Animals ; Bacteria/*metabolism ; *Chemoautotrophic Growth ; Gene Expression Profiling ; *Gene Expression Regulation ; Gills/microbiology ; Hydrothermal Vents ; Microbiota ; Mytilidae/genetics/*microbiology ; Proteomics ; *Symbiosis ; }, abstract = {BACKGROUND: Colonization of deep-sea hydrothermal vents by most invertebrates was made efficient through their adaptation to a symbiotic lifestyle with chemosynthetic bacteria, the primary producers in these ecosystems. Anatomical adaptations such as the establishment of specialized cells or organs have been evidenced in numerous deep-sea invertebrates. However, very few studies detailed global inter-dependencies between host and symbionts in these ecosystems. In this study, we proposed to describe, using a proteo-transcriptomic approach, the effects of symbionts loss on the deep-sea mussel Bathymodiolus azoricus' molecular biology. We induced an in situ depletion of symbionts and compared the proteo-transcriptome of the gills of mussels in three conditions: symbiotic mussels (natural population), symbiont-depleted mussels and aposymbiotic mussels.<br><br>RESULTS: Global proteomic and transcriptomic results evidenced a global disruption of host machinery in aposymbiotic organisms. We observed that the total number of proteins identified decreased from 1118 in symbiotic mussels to 790 in partially depleted mussels and 761 in aposymbiotic mussels. Using microarrays we identified 4300 transcripts differentially expressed between symbiont-depleted and symbiotic mussels. Among these transcripts, 799 were found differentially expressed in aposymbiotic mussels and almost twice as many in symbiont-depleted mussels as compared to symbiotic mussels. Regarding apoptotic and immune system processes - known to be largely involved in symbiotic interactions - an overall up-regulation of associated proteins and transcripts was observed in symbiont-depleted mussels.<br><br>CONCLUSION: Overall, our study showed a global impairment of host machinery and an activation of both the immune and apoptotic system following symbiont-depletion. One of the main assumptions is the involvement of symbiotic bacteria in the inhibition and regulation of immune and apoptotic systems. As such, symbiotic bacteria may increase their lifespan in gill cells while managing the defense of the holobiont against putative pathogens.}, }
@article {pmid30718604, year = {2019}, author = {Lanzoni, O and Sabaneyeva, E and Modeo, L and Castelli, M and Lebedeva, N and Verni, F and Schrallhammer, M and Potekhin, A and Petroni, G}, title = {Diversity and environmental distribution of the cosmopolitan endosymbiont "Candidatus Megaira".}, journal = {Scientific reports}, volume = {9}, number = {1}, pages = {1179}, pmid = {30718604}, issn = {2045-2322}, mesh = {Aquatic Organisms/microbiology ; Ciliophora/*microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; *Genetic Variation ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae/*classification/genetics/*isolation &amp; purification/physiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Members of the order Rickettsiales are often found in association with ciliated protists. An interesting case is the bacterial endosymbiont "Candidatus Megaira", which is phylogenetically closely related to the pathogen Rickettsia. "Candidatus Megaira" was first described as an intracellular bacterium in several ciliate species. Since then it has been found in association with diverse evolutionary distantly-related hosts, among them other unicellular eukaryotes, and also algae, and metazoa, such as cnidarians. We provide the characterization of several new strains of the type species "Candidatus Megaira polyxenophila", and the multidisciplinary description of a novel species, "Candidatus Megaira venefica", presenting peculiar features, which highlight the diversity and variability of these widespread bacterial endosymbionts. Screening of the 16S rRNA gene short amplicon database and phylogenetic analysis of 16S rRNA gene hypervariable regions revealed the presence of further hidden lineages, and provided hints on the possibility that these bacteria may be horizontally transmitted among aquatic protists and metazoa. The phylogenetic reconstruction supports the existence of at least five different separate species-level clades of "Candidatus Megaira", and we designed a set of specific probes allowing easy recognition of the four major clades of the genus.}, }
@article {pmid30716462, year = {2019}, author = {Odeniran, PO and Macleod, ET and Ademola, IO and Welburn, SC}, title = {Endosymbionts interaction with trypanosomes in Palpalis group of Glossina captured in southwest Nigeria.}, journal = {Parasitology international}, volume = {70}, number = {}, pages = {64-69}, doi = {10.1016/j.parint.2019.01.011}, pmid = {30716462}, issn = {1873-0329}, mesh = {Animals ; Enterobacteriaceae/*isolation &amp; purification/physiology ; Insect Vectors/microbiology/parasitology ; Nigeria ; Polymerase Chain Reaction ; Prevalence ; *Symbiosis ; Trypanosoma/microbiology/*physiology ; Tsetse Flies/*microbiology/*parasitology ; Wolbachia ; }, abstract = {Glossina species epidemiological studies were conducted in "fly-belt" endemic zone of southwest Nigeria. Two major study areas were identified and four Nzi traps were set in each site for tsetse collection. This study was conducted to determine the prevalence of endosymbionts (Wigglesworthia glossinidia, Sodalis glossinidius and Wolbachia) in natural field-trapped populations of G. p. palpalis and G. tachinoides and investigate the corresponding interactions with African trypanosomes. A total of 64 tsetse flies were collected, these included G. p. palpalis (n = 28) and G. tachinoides (n = 36). Trypanosome infection and endosymbionts of these flies were determined using polymerase chain reaction (PCR) amplification. The infection rates of W. glossinidia was 100.0% in both species, no flies were positive for Wolbachia. Sodalis glossinidius prevalence was similar between the two-tsetse species, with G. p. palpalis and G. tachinoides showing prevalence of 35.7% (95%CI: 20.7-54.2) and 27.8% (95%CI: 15.9-44.0) respectively. No relationship was found between the endosymbionts and trypanosomes in trapped tsetse flies. More studies are needed to enhance the potential control interventions mediated by endosymbionts to reduce parasitic infections.}, }
@article {pmid30716127, year = {2019}, author = {Piquet, B and Shillito, B and Lallier, FH and Duperron, S and Andersen, AC}, title = {High rates of apoptosis visualized in the symbiont-bearing gills of deep-sea Bathymodiolus mussels.}, journal = {PloS one}, volume = {14}, number = {2}, pages = {e0211499}, pmid = {30716127}, issn = {1932-6203}, mesh = {Animals ; *Apoptosis ; Bivalvia/*cytology/*physiology ; Gills/*cytology ; Hydrothermal Vents ; Species Specificity ; *Symbiosis ; }, abstract = {Symbiosis between Bathymodiolus and Gammaproteobacteria allows these deep-sea mussels to live in toxic environments such as hydrothermal vents and cold seeps. The quantity of endosymbionts within the gill-bacteriocytes appears to vary according to the hosts environment; however, the mechanisms of endosymbiont population size regulation remain obscure. We investigated the possibility of a control of endosymbiont density by apoptosis, a programmed cell death, in three mussel species. Fluorometric TUNEL and active Caspase-3-targeting antibodies were used to visualize and quantify apoptotic cells in mussel gills. To control for potential artefacts due to depressurization upon specimen recovery from the deep-sea, the apoptotic rates between mussels recovered unpressurised, versus mussels recovered in a pressure-maintaining device, were compared in two species from hydrothermal vents on the Mid-Atlantic Ridge: Bathymodiolus azoricus and B. puteoserpentis. Results show that pressurized recovery had no significant effect on the apoptotic rate in the gill filaments. Apoptotic levels were highest in the ciliated zone and in the circulating hemocytes, compared to the bacteriocyte zone. Apoptotic gill-cells in B. aff. boomerang from cold seeps off the Gulf of Guinea show similar distribution patterns. Deep-sea symbiotic mussels have much higher rates of apoptosis in their gills than the coastal mussel Mytilus edulis, which lacks chemolithoautotrophic symbionts. We discuss how apoptosis might be one of the mechanisms that contribute to the adaptation of deep-sea mussels to toxic environments and/or to symbiosis.}, }
@article {pmid30715337, year = {2019}, author = {Sinha, A and Li, Z and Sun, L and Carlow, CKS}, title = {Complete Genome Sequence of the Wolbachia wAlbB Endosymbiont of Aedes albopictus.}, journal = {Genome biology and evolution}, volume = {11}, number = {3}, pages = {706-720}, pmid = {30715337}, issn = {1759-6653}, mesh = {Aedes/*microbiology ; Animals ; Ankyrins/genetics ; Cell Line ; DNA Transposable Elements ; Genome Size ; *Genome, Bacterial ; Prophages/genetics ; Proteome ; Type IV Secretion Systems ; Wolbachia/*genetics ; }, abstract = {Wolbachia, an alpha-proteobacterium closely related to Rickettsia, is a maternally transmitted, intracellular symbiont of arthropods and nematodes. Aedes albopictus mosquitoes are naturally infected with Wolbachia strains wAlbA and wAlbB. Cell line Aa23 established from Ae. albopictus embryos retains only wAlbB and is a key model to study host-endosymbiont interactions. We have assembled the complete circular genome of wAlbB from the Aa23 cell line using long-read PacBio sequencing at 500× median coverage. The assembled circular chromosome is 1.48 megabases in size, an increase of more than 300 kb over the published draft wAlbB genome. The annotation of the genome identified 1,205 protein coding genes, 34 tRNA, 3 rRNA, 1 tmRNA, and 3 other ncRNA loci. The long reads enabled sequencing over complex repeat regions which are difficult to resolve with short-read sequencing. Thirteen percent of the genome comprised insertion sequence elements distributed throughout the genome, some of which cause pseudogenization. Prophage WO genes encoding some essential components of phage particle assembly are missing, while the remainder are found in five prophage regions/WO-like islands or scattered around the genome. Orthology analysis identified a core proteome of 535 orthogroups across all completed Wolbachia genomes. The majority of proteins could be annotated using Pfam and eggNOG analyses, including ankyrins and components of the Type IV secretion system. KEGG analysis revealed the absence of five genes in wAlbB which are present in other Wolbachia. The availability of a complete circular chromosome from wAlbB will enable further biochemical, molecular, and genetic analyses on this strain and related Wolbachia.}, }
@article {pmid30714238, year = {2019}, author = {Fromont, C and Adair, KL and Douglas, AE}, title = {Correlation and causation between the microbiome, Wolbachia and host functional traits in natural populations of drosophilid flies.}, journal = {Molecular ecology}, volume = {28}, number = {7}, pages = {1826-1841}, doi = {10.1111/mec.15041}, pmid = {30714238}, issn = {1365-294X}, support = {BIO 1241099//National Science Foundation/International ; }, mesh = {Animals ; Bacteria/*classification ; Drosophila/classification/*microbiology ; *Microbiota ; RNA, Ribosomal, 16S/genetics ; Spiroplasma/genetics ; Symbiosis ; Sympatry ; Transcriptome ; Wolbachia/*genetics ; }, abstract = {Resident microorganisms are known to influence the fitness and traits of animals under controlled laboratory conditions, but the relevance of these findings to wild animals is uncertain. This study investigated the host functional correlates of microbiota composition in a wild community of three sympatric species of mycophagous drosophilid flies, Drosophila falleni, Drosophila neotestacea and Drosophila putrida. Specifically, we quantified bacterial communities and host transcriptomes by parallel 16S rRNA gene amplicon sequencing and RNA-Seq of individual flies. Among-fly variation in microbiota composition did not partition strongly by sex or species, and included multiple modules, that is, sets of bacterial taxa whose abundance varied in concert across different flies. The abundance of bacteria in several modules varied significantly with multiple host transcripts, especially in females, but the identity of the correlated host transcriptional functions differed with host species, including epithelial barrier function in D. falleni, muscle function in D. putrida, and insect growth and development in D. neotestacea. In D. neotestacea, which harbours the endosymbionts Wolbachia and Spiroplasma, Wolbachia promotes the abundance of Spiroplasma, and is positively correlated with abundance of Lactobacillales and Bacteroidales. Furthermore, most correlations between host gene expression and relative abundance of bacterial modules were co-correlated with abundance of Wolbachia (but not Spiroplasma), indicative of an interdependence between host functional traits, microbiota composition and Wolbachia abundance in this species. These data suggest that, in these natural populations of drosophilid flies, different host species interact with microbial communities in functionally different ways that can vary with the abundance of endosymbionts.}, }
@article {pmid30713526, year = {2018}, author = {Lavy, O and Gophna, U and Gefen, E and Ayali, A}, title = {The Effect of Density-Dependent Phase on the Locust Gut Bacterial Composition.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {3020}, pmid = {30713526}, issn = {1664-302X}, abstract = {The desert locust demonstrates density-dependent phase polyphenism: For extended periods it appears in a non-aggregating, non-migrating phenotype, known as the solitary phase. When circumstances change, solitary individuals may aggregate and transform to the gregarious phenotype, which have a strong propensity for generating large swarms. Previous reports have suggested a role for gut-bacteria derived volatiles in the swarming phenomenon, and suggested that locusts are capable of manipulating their gut microbiome according to their density-dependent phases. Here, we directly tested this hypothesis for the first time. Using locusts of both phases from well-controlled laboratory cultures as well as gregarious field-collected individuals; and high-throughput sequencing. We characterized the hindgut bacterial community composition in the two phases of the desert locust. Our findings demonstrate that laboratory-reared gregarious and solitary locusts maintain a stable core of Enterobacter. However, while different generations of gregarious locust experience shifts in their Enterobacter's relative abundance; the solitary locusts maintain a stable gut microbiome, highly similar to that of the field-collected locusts. Tentative phase differences in wild populations' microbiome may thus be an indirect effect of environmental or other factors that push the swarming individuals to homogenous gut bacteria. We therefore conclude that there are phase-related differences in the population dynamics of the locust hindgut bacterial composition, but there is no intrinsic density-dependent mechanism directly affecting the gut microbiome.}, }
@article {pmid30708135, year = {2019}, author = {Konecka, E and Olszanowski, Z}, title = {Phylogenetic analysis based on the 16S rDNA, gltA, gatB, and hcpA gene sequences of Wolbachia from the novel host Ceratozetes thienemanni (Acari: Oribatida).}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {70}, number = {}, pages = {175-181}, doi = {10.1016/j.meegid.2019.01.032}, pmid = {30708135}, issn = {1567-7257}, mesh = {Animals ; Bacterial Proteins/genetics ; DNA, Ribosomal/genetics ; Host Microbial Interactions ; Mites/microbiology ; Phylogeny ; Symbiosis/*genetics ; Wolbachia/*classification/genetics ; }, abstract = {We determined the occurrence of intracellular endosymbionts (Wolbachia, Cardinium, Arsenophonus, Rickettsia, Spiroplasma, Hamiltonella, flavobacteria, and microsporidia) in oribatid mites (Acari: Oribatida) with the use of PCR technique. For the first time we looked for and detected Wolbachia in parthenogenetic oribatid mite Ceratozetes thienemanni Willmann, 1943. The 16S rDNA, gatB, hcpA, and gltA sequences of Wolbachia in C. thienemanni showed the highest similarity (≥ 90%) to the genes of Wolbachia from springtails (Collembola) and oribatid mite Gustavia microcephala. We found the unique sequence 5'-GGGGTAATGGCC-3' in 16S rDNA of Wolbachia from C. thienemanni and collembolan representing group E. The phylogeny of Wolbachia based on the analysis of single genes as well as concatenated alignments of four bacterial loci showed that the bacteria from C. thienemanni belonged to Wolbachia group E, like the endosymbionts from springtail hosts and G. microcephala. Considering coexisting of representatives of Oribatida and Collembola in the same soil habitat and similar food, it is possible that the source of Wolbachia infection was the same. Residues of dead invertebrates could be in organic matter of their soil food, so the scenario of infection transferred by eating of remains of soil cohabitates is also possible. It could explain the similarity and relationship of the Wolbachia in these two arthropod groups. Oribatid mite C. thienemanni is a parthenogenetic mite which is a unique feature in the genus Ceratozetes. Moreover, this species, within the entire genus Ceratozetes, is characterized by the most northerly distribution. It is difficult to determine either it is parthenogenesis or the presence of endosymbionts that are in some way responsible for this kind of evolutionary success. Maybe we are dealing here with a kind of synergy of both factors?}, }
@article {pmid30705413, year = {2019}, author = {Epstein, HE and Torda, G and Munday, PL and van Oppen, MJH}, title = {Parental and early life stage environments drive establishment of bacterial and dinoflagellate communities in a common coral.}, journal = {The ISME journal}, volume = {13}, number = {6}, pages = {1635-1638}, pmid = {30705413}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*growth &amp; development/*microbiology/parasitology/physiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Dinoflagellida/classification/genetics/*isolation &amp; purification ; Microbiota ; Symbiosis ; }, abstract = {The establishment of coral microbial communities in early developmental stages is fundamental to coral fitness, but its drivers are largely unknown, particularly for bacteria. Using an in situ reciprocal transplant experiment, we examined the influence of parental, planulation and early recruit environments on the microbiome of brooded offspring in the coral Pocillopora damicornis. 16S rRNA and ITS2 rDNA gene metabarcoding showed that bacterial and microalgal endosymbiont communities varied according to parental and planulation environments, but not with early recruit environment. Only a small number of bacterial strains were shared between offspring and their respective parents, revealing bacterial establishment as largely environmentally driven in very early life stages. Conversely, microalgal communities of recruits were highly similar to those of their respective parents, but also contained additional low abundance strains, suggesting both vertical transmission and novel ('horizontal') acquisition. Altogether, recruits harboured more variable microbiomes compared to their parents, indicating winnowing occurs as corals mature.}, }
@article {pmid30670614, year = {2019}, author = {González-Torres, P and Rodríguez-Mateos, F and Antón, J and Gabaldón, T}, title = {Impact of Homologous Recombination on the Evolution of Prokaryotic Core Genomes.}, journal = {mBio}, volume = {10}, number = {1}, pages = {}, pmid = {30670614}, issn = {2150-7511}, mesh = {*Adaptation, Biological ; Archaea/*genetics ; Bacteria/*genetics ; Computational Biology ; *Evolution, Molecular ; *Genome, Archaeal ; *Genome, Bacterial ; *Homologous Recombination ; }, abstract = {Homologous recombination (HR) enables the exchange of genetic material between and within species. Recent studies suggest that this process plays a major role in the microevolution of microbial genomes, contributing to core genome homogenization and to the maintenance of cohesive population structures. However, we still have a very poor understanding of the possible adaptive roles of intraspecific HR and of the factors that determine its differential impact across clades and lifestyles. Here we used a unified methodological framework to assess HR in 338 complete genomes from 54 phylogenetically diverse and representative prokaryotic species, encompassing different lifestyles and a broad phylogenetic distribution. Our results indicate that lifestyle and presence of restriction-modification (RM) machineries are among the main factors shaping HR patterns, with symbionts and intracellular pathogens having the lowest HR levels. Similarly, the size of exchanged genomic fragments correlated with the presence of RM and competence machineries. Finally, genes exchanged by HR showed functional enrichments which could be related to adaptations to different environments and ecological strategies. Taken together, our results clarify the factors underlying HR impact and suggest important adaptive roles of genes exchanged through this mechanism. Our results also revealed that the extent of genetic exchange correlated with lifestyle and some genomic features. Moreover, the genes in exchanged regions were enriched for functions that reflected specific adaptations, supporting identification of HR as one of the main evolutionary mechanisms shaping prokaryotic core genomes.IMPORTANCE Microbial populations exchange genetic material through a process called homologous recombination. Although this process has been studied in particular organisms, we lack an understanding of its differential impact over the genome and across microbes with different life-styles. We used a common analytical framework to assess this process in a representative set of microorganisms. Our results uncovered important trends. First, microbes with different lifestyles are differentially impacted, with endosymbionts and obligate pathogens being those less prone to undergo this process. Second, certain genetic elements such as restriction-modification systems seem to be associated with higher rates of recombination. Most importantly, recombined genomes show the footprints of natural selection in which recombined regions preferentially contain genes that can be related to specific ecological adaptations. Taken together, our results clarify the relative contributions of factors modulating homologous recombination and show evidence for a clear a role of this process in shaping microbial genomes and driving ecological adaptations.}, }
@article {pmid30668787, year = {2019}, author = {Chebbi, MA and Becking, T and Moumen, B and Giraud, I and Gilbert, C and Peccoud, J and Cordaux, R}, title = {The Genome of Armadillidium vulgare (Crustacea, Isopoda) Provides Insights into Sex Chromosome Evolution in the Context of Cytoplasmic Sex Determination.}, journal = {Molecular biology and evolution}, volume = {36}, number = {4}, pages = {727-741}, doi = {10.1093/molbev/msz010}, pmid = {30668787}, issn = {1537-1719}, mesh = {Animals ; *Biological Evolution ; Female ; *Genome ; Isopoda/*genetics ; Male ; *Sex Chromosomes ; *Sex Determination Processes ; Wolbachia/genetics ; }, abstract = {The terrestrial isopod Armadillidium vulgare is an original model to study the evolution of sex determination and symbiosis in animals. Its sex can be determined by ZW sex chromosomes, or by feminizing Wolbachia bacterial endosymbionts. Here, we report the sequence and analysis of the ZW female genome of A. vulgare. A distinguishing feature of the 1.72 gigabase assembly is the abundance of repeats (68% of the genome). We show that the Z and W sex chromosomes are essentially undifferentiated at the molecular level and the W-specific region is extremely small (at most several hundreds of kilobases). Our results suggest that recombination suppression has not spread very far from the sex-determining locus, if at all. This is consistent with A. vulgare possessing evolutionarily young sex chromosomes. We characterized multiple Wolbachia nuclear inserts in the A. vulgare genome, none of which is associated with the W-specific region. We also identified several candidate genes that may be involved in the sex determination or sexual differentiation pathways. The A. vulgare genome serves as a resource for studying the biology and evolution of crustaceans, one of the most speciose and emblematic metazoan groups.}, }
@article {pmid30668658, year = {2019}, author = {Moreira, M and Aguiar, AMF and Bourtzis, K and Latorre, A and Khadem, M}, title = {Wolbachia (Alphaproteobacteria: Rickettsiales) Infections in Isolated Aphid Populations from Oceanic Islands of the Azores Archipelago: Revisiting the Supergroups M and N.}, journal = {Environmental entomology}, volume = {48}, number = {2}, pages = {326-334}, doi = {10.1093/ee/nvy189}, pmid = {30668658}, issn = {1938-2936}, mesh = {Animals ; Aphids/genetics/*microbiology ; Azores ; Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Aphids (Hemiptera: Aphididae) have provided a suitable model to study endosymbionts, their community, and dynamics since the discovery of the obligate endosymbiont Buchnera aphidicola in these organisms. In previous studies, Wolbachia was found in some aphid species. In the present study, we report the prevalence of Wolbachia in aphids sampled from a geographically isolated region (Azores Islands), aiming at a better understanding and characterization of the two newly reported supergroups, M and N. The description of the supergroup M was based on 16S rRNA as well as some protein-coding genes. However, the assignment of the supergroup N was according to 16S rRNA gene sequences of a very few samples. We collected aphid samples and performed phylogenetic analysis of 16S rRNA gene as well as four protein-coding genes (gatB, ftsZ, coxA, and hcpA). The results demonstrate that the 16S rRNA gene data can unambiguously assign the strain supergroup and that the two supergroups, N and M, are equally prevalent in Azorean aphids. The available sequence data for the protein-coding markers can identify supergroup M but the status of supergroup N is inconclusive, requiring further studies. The data suggest that horizontal transmission of Wolbachia (Hertig and Wolbach) between two phylogenetically distant aphid species cohabiting the same plant host.}, }
@article {pmid30663253, year = {2020}, author = {Tang, XT and Ibanez, F and Tamborindeguy, C}, title = {Quenching autofluorescence in the alimentary canal tissues of Bactericera cockerelli (Hemiptera: Triozidae) for immunofluorescence labeling.}, journal = {Insect science}, volume = {27}, number = {3}, pages = {475-486}, doi = {10.1111/1744-7917.12660}, pmid = {30663253}, issn = {1744-7917}, mesh = {Animals ; *Azo Compounds ; Fluorescent Antibody Technique/*methods ; Gastrointestinal Tract/*microbiology ; Hemiptera/*anatomy &amp; histology/microbiology ; *Naphthalenes ; Optical Imaging/methods ; Rhizobiaceae/isolation &amp; purification ; Staining and Labeling/*methods ; }, abstract = {Immunofluorescence has been widely used to localize microbes or specific molecules in insect tissues or cells. However, significant autofluorescence is frequently observed in tissues which can interfere with the fluorescent identification of target antigens, leading to inaccurate or even false positive fluorescent labeling. The alimentary canal of the potato psyllid, Bactericera cockerelli Šulc, exhibits intense autofluorescence, hindering the application of immunolocalization for the detection and localization of the economically important pathogen transmitted by this insect, "Candidatus Liberibacter solanacearum" (Lso). In the present study, we tested the use of irradiation, hydrogen peroxide (H2 O2) and Sudan black B (SBB) treatments to reduce the autofluorescence in the B. cockerelli alimentary canal tissues. Furthermore, we assessed the compatibility of the above-mentioned treatments with Lso immunolocalization and actin staining using phalloidin. Our results showed that the autofluorescence in the alimentary canal was reduced by irradiation, H2 O2 , or SBB treatments. The compatibility assays indicated that irradiation and H2 O2 treatment both greatly reduced the fluorescent signal associated with Lso and actin. However, the SBB incubation preserved those target signals, while efficiently eliminating autofluorescence in the psyllid alimentary canal. Therefore, herein we propose a robust method for reducing the autofluorescence in the B. cockerelli alimentary canal with SBB treatment, which may improve the use of immunofluorescence labeling in this organism. This method may also have a wide range of uses by reducing the autofluorescence in other arthropod species.}, }
@article {pmid30657252, year = {2019}, author = {Adhav, A and Harne, S and Bhide, A and Giri, A and Gayathri, P and Joshi, R}, title = {Mechanistic insights into enzymatic catalysis by trehalase from the insect gut endosymbiont Enterobacter cloacae.}, journal = {The FEBS journal}, volume = {286}, number = {9}, pages = {1700-1716}, doi = {10.1111/febs.14760}, pmid = {30657252}, issn = {1742-4658}, mesh = {Animals ; Bacterial Proteins/antagonists &amp; inhibitors/chemistry/*metabolism ; Biocatalysis ; Catalytic Domain ; Crystallography, X-Ray ; Enterobacter cloacae/*enzymology ; Inositol/analogs &amp; derivatives/pharmacology ; Kinetics ; Ligands ; Models, Molecular ; Moths/microbiology ; Protein Binding ; Protein Conformation ; Recombinant Proteins/chemistry/metabolism ; Symbiosis ; Trehalase/antagonists &amp; inhibitors/chemistry/*metabolism ; Tryptophan/chemistry ; }, abstract = {Energy metabolism in the diamondback moth Plutella xylostella is facilitated by trehalase, an enzyme which assists in trehalose hydrolysis, from the predominant gut bacterium Enterobacter cloacae. We report the biochemical and structural characterization of recombinant trehalase from E. cloacae (Px_EclTre). Px_EclTre showed KM of 1.47 (±0.05) mm, kcat of 6254.72 min[-1] and Vmax 0.2 (±0.002) mm·min[-1] at 55 °C and acidic pH. Crystal structures of Px_EclTre were determined in the ligand-free form and bound to the inhibitor Validoxylamine A. The crystal structure of the ligand-free form, unavailable until now for any other bacterial trehalases, enabled us to delineate the conformational changes accompanying ligand binding in trehalases. Multiple salt bridges were identified that potentially facilitated closure of a hood over the substrate-binding site. A cluster of five tryptophans lined the -1 substrate-binding subsite, interacted with crucial active site residues and contributed to both trehalase activity and stability. The importance of these residues in enzyme activity was further validated by mutagenesis studies. Many of these identified residues form part of signature motifs and other conserved sequences in trehalases. The structure analysis thus led to the assignment of the functional role to these conserved residues. This information can be further explored for the design of effective inhibitors against trehalases.}, }
@article {pmid30640905, year = {2019}, author = {Ravi, A and Ereqat, S and Al-Jawabreh, A and Abdeen, Z and Abu Shamma, O and Hall, H and Pallen, MJ and Nasereddin, A}, title = {Metagenomic profiling of ticks: Identification of novel rickettsial genomes and detection of tick-borne canine parvovirus.}, journal = {PLoS neglected tropical diseases}, volume = {13}, number = {1}, pages = {e0006805}, pmid = {30640905}, issn = {1935-2735}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Anaplasma ovis/genetics/isolation &amp; purification ; Animals ; Camelus ; Coxiella/classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Dogs ; Francisella/classification/genetics/isolation &amp; purification ; Genome, Bacterial/*genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Insect Vectors/genetics/microbiology/virology ; Israel/epidemiology ; Ixodes/*microbiology/*virology ; Parvovirus, Canine/genetics/*isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/genetics/*isolation &amp; purification ; Sheep ; Tick-Borne Diseases/epidemiology ; }, abstract = {BACKGROUND: Across the world, ticks act as vectors of human and animal pathogens. Ticks rely on bacterial endosymbionts, which often share close and complex evolutionary links with tick-borne pathogens. As the prevalence, diversity and virulence potential of tick-borne agents remain poorly understood, there is a pressing need for microbial surveillance of ticks as potential disease vectors.<br><br>We developed a two-stage protocol that includes 16S-amplicon screening of pooled samples of hard ticks collected from dogs, sheep and camels in Palestine, followed by shotgun metagenomics on individual ticks to detect and characterise tick-borne pathogens and endosymbionts. Two ticks isolated from sheep yielded an abundance of reads from the genus Rickettsia, which were assembled into draft genomes. One of the resulting genomes was highly similar to Rickettsia massiliae strain MTU5. Analysis of signature genes showed that the other represents the first genome sequence of the potential pathogen Candidatus Rickettsia barbariae. Ticks from a dog and a sheep yielded draft genome sequences of Coxiella strains. A sheep tick yielded sequences from the sheep pathogen Anaplasma ovis, while Hyalomma ticks from camels yielded sequences belonging to Francisella-like endosymbionts. From the metagenome of a dog tick from Jericho, we generated a genome sequence of a canine parvovirus.<br><br>SIGNIFICANCE: Here, we have shown how a cost-effective two-stage protocol can be used to detect and characterise tick-borne pathogens and endosymbionts. In recovering genome sequences from an unexpected pathogen (canine parvovirus) and a previously unsequenced pathogen (Candidatus Rickettsia barbariae), we demonstrate the open-ended nature of metagenomics. We also provide evidence that ticks can carry canine parvovirus, raising the possibility that ticks might contribute to the spread of this troublesome virus.}, }
@article {pmid30635006, year = {2019}, author = {Brinkmann, A and Hekimoğlu, O and Dinçer, E and Hagedorn, P and Nitsche, A and Ergünay, K}, title = {A cross-sectional screening by next-generation sequencing reveals Rickettsia, Coxiella, Francisella, Borrelia, Babesia, Theileria and Hemolivia species in ticks from Anatolia.}, journal = {Parasites &amp; vectors}, volume = {12}, number = {1}, pages = {26}, pmid = {30635006}, issn = {1756-3305}, mesh = {Animals ; Arthropod Vectors/microbiology ; Arthropods ; Babesia/genetics/isolation &amp; purification ; Bacteria/*isolation &amp; purification ; Borrelia/genetics/isolation &amp; purification ; Coxiella/genetics/isolation &amp; purification ; Cross-Sectional Studies ; Francisella/genetics/isolation &amp; purification ; Humans ; Nucleic Acid Amplification Techniques/*methods ; Rickettsia/genetics/isolation &amp; purification ; Species Specificity ; Theileria/genetics/isolation &amp; purification ; Ticks/*microbiology ; Turkey ; }, abstract = {BACKGROUND: Ticks participate as arthropod vectors in the transmission of pathogenic microorganisms to humans. Several tick-borne infections have reemerged, along with newly described agents of unexplored pathogenicity. In an attempt to expand current information on tick-associated bacteria and protozoans, we performed a cross-sectional screening of ticks, using next-generation sequencing. Ticks seeking hosts and infesting domestic animals were collected in four provinces across the Aegean, Mediterranean and Central Anatolia regions of Turkey and analyzed by commonly used procedures and platforms.<br><br>RESULTS: Two hundred and eighty ticks comprising 10 species were evaluated in 40 pools. Contigs from tick-associated microorganisms were detected in 22 (55%) questing and 4 feeding (10%) tick pools, with multiple microorganisms identified in 12 pools. Rickettsia 16S ribosomal RNA gene, gltA, sca1 and ompA sequences were present in 7 pools (17.5%), comprising feeding Haemaphysalis parva and questing/hunting Rhipicephalus bursa, Rhipicephalus sanguineus (sensu lato) and Hyalomma marginatum specimens. A near-complete genome and conjugative plasmid of a Rickettsia hoogstraalii strain could be characterized in questing Ha. parva. Coxiella-like endosymbionts were identified in pools of questing (12/40) as well as feeding (4/40) ticks of the genera Rhipicephalus, Haemaphysalis and Hyalomma. Francisella-like endosymbionts were also detected in 22.5% (9/40) of the pools that comprise hunting Hyalomma ticks in 8 pools. Coxiella-like and Francisella-like endosymbionts formed phylogenetically distinct clusters associated with their tick hosts. Borrelia turcica was characterized in 5% (2/40) of the pools, comprising hunting Hyalomma aegyptium ticks. Co-infection of Coxiella-like endosymbiont and Babesia was noted in a questing R. sanguineus (s.l.) specimen. Furthermore, protozoan 18S rRNA gene sequences were detected in 4 pools of questing/hunting ticks (10%) and identified as Babesia ovis, Hemolivia mauritanica, Babesia and Theileria spp.<br><br>CONCLUSIONS: Our metagenomic approach enabled identification of diverse pathogenic and non-pathogenic microorganisms in questing and feeding ticks in Anatolia.}, }
@article {pmid30629162, year = {2019}, author = {Ševcíková, T and Yurchenko, T and Fawley, KP and Amaral, R and Strnad, H and Santos, LMA and Fawley, MW and Eliáš, M}, title = {Plastid Genomes and Proteins Illuminate the Evolution of Eustigmatophyte Algae and Their Bacterial Endosymbionts.}, journal = {Genome biology and evolution}, volume = {11}, number = {2}, pages = {362-379}, pmid = {30629162}, issn = {1759-6653}, support = {P20 GM103429/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; *Biological Evolution ; *Genome, Plastid ; *Operon ; Rickettsiaceae/*genetics ; Stramenopiles/*genetics/microbiology ; Symbiosis ; }, abstract = {Eustigmatophytes, a class of stramenopile algae (ochrophytes), include not only the extensively studied biotechnologically important genus Nannochloropsis but also a rapidly expanding diversity of lineages with much less well characterized biology. Recent discoveries have led to exciting additions to our knowledge about eustigmatophytes. Some proved to harbor bacterial endosymbionts representing a novel genus, Candidatus Phycorickettsia, and an operon of unclear function (ebo) obtained by horizontal gene transfer from the endosymbiont lineage was found in the plastid genomes of still other eustigmatophytes. To shed more light on the latter event, as well as to generally improve our understanding of the eustigmatophyte evolutionary history, we sequenced plastid genomes of seven phylogenetically diverse representatives (including new isolates representing undescribed taxa). A phylogenomic analysis of plastid genome-encoded proteins resolved the phylogenetic relationships among the main eustigmatophyte lineages and provided a framework for the interpretation of plastid gene gains and losses in the group. The ebo operon gain was inferred to have probably occurred within the order Eustigmatales, after the divergence of the two basalmost lineages (a newly discovered hitherto undescribed strain and the Pseudellipsoidion group). When looking for nuclear genes potentially compensating for plastid gene losses, we noticed a gene for a plastid-targeted acyl carrier protein that was apparently acquired by horizontal gene transfer from Phycorickettsia. The presence of this gene in all eustigmatophytes studied, including representatives of both principal clades (Eustigmatales and Goniochloridales), is a genetic footprint indicating that the eustigmatophyte-Phycorickettsia partnership started no later than in the last eustigmatophyte common ancestor.}, }
@article {pmid30629155, year = {2019}, author = {Sazama, EJ and Ouellette, SP and Wesner, JS}, title = {Bacterial Endosymbionts Are Common Among, but not Necessarily Within, Insect Species.}, journal = {Environmental entomology}, volume = {48}, number = {1}, pages = {127-133}, doi = {10.1093/ee/nvy188}, pmid = {30629155}, issn = {1938-2936}, mesh = {Animals ; Insecta/*microbiology ; Linear Models ; Rickettsiales ; *Symbiosis ; Wolbachia ; }, abstract = {Bacterial endosymbionts, particularly Wolbachia (Rickettsiales: Rickettsiaceae), Rickettsia (Rickettsiales: Rickettsiaceae), and Cardinium (Bacteroidales: Bacteroidaceae), are commonly found in several arthropod groups, including insects. Most estimates of the global infection rate of Wolbachia (52% [95% credible intervals: 44-60]) show that these bacteria infect more than half of all insect species. Other endosymbionts, such as Rickettsia (24% [confidence intervals [CIs] 20-42]) and Cardinium (13% [CIs 13-55]), infect a smaller but still substantial proportion of insect species. In spite of these observations, it is unclear what proportion of individuals within those species are infected. Here, we used published databases to estimate the proportion of individuals that are infected with either Wolbachia, Rickettsia, or Cardinium. We found that the majority (69%) of Wolbachia-infected species have less than half of their individuals infected with Wolbachia, indicating that although the bacterium may be common among species, it is not common within species. The same was true for Rickettsia (81%) and Cardinium (87%). This discrepancy was consistent across orders, in which less than 10% of individuals were typically infected, even though more than 50% of species within orders were infected. For example, according to our model, nearly 50% of beetle (Coleoptera) species are infected with Wolbachia (i.e., contain at least one individual that has tested positive for Wolbachia), but less than 5% of all individuals are infected. These results add to the growing knowledge base about endosymbionts in insects and should guide future sampling efforts and investigations on the role that these bacteria play in populations.}, }
@article {pmid30627761, year = {2019}, author = {Fokin, SI and Serra, V and Ferrantini, F and Modeo, L and Petroni, G}, title = {"Candidatus Hafkinia simulans" gen. nov., sp. nov., a Novel Holospora-Like Bacterium from the Macronucleus of the Rare Brackish Water Ciliate Frontonia salmastra (Oligohymenophorea, Ciliophora): Multidisciplinary Characterization of the New Endosymbiont and Its Host.}, journal = {Microbial ecology}, volume = {77}, number = {4}, pages = {1092-1106}, pmid = {30627761}, issn = {1432-184X}, mesh = {Holosporaceae/classification/genetics/*physiology/ultrastructure ; Italy ; Macronucleus/microbiology ; Microscopy, Electron, Transmission ; Peniculina/*microbiology/physiology ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; RNA, Ribosomal, 18S/analysis ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {We characterized a novel Holospora-like bacterium (HLB) (Alphaproteobacteria, Holosporales) living in the macronucleus of the brackish water ciliate Frontonia salmastra. This bacterium was morphologically and ultrastructurally investigated, and its life cycle and infection capabilities were described. We also obtained its 16S rRNA gene sequence and performed in situ hybridization experiments with a specifically-designed probe. A new taxon, "Candidatus Hafkinia simulans", was established for this HLB. The phylogeny of the family Holosporaceae based on 16S rRNA gene sequences was inferred, adding to the already available data both the sequence of the novel bacterium and those of other Holospora and HLB species recently characterized. Our phylogenetic analysis provided molecular support for the monophyly of HLBs and placed the new endosymbiont as the sister genus of Holospora. Additionally, the host ciliate F. salmastra, recorded in Europe for the first time, was concurrently described through a multidisciplinary study. Frontonia salmastra's phylogenetic position in the subclass Peniculia and the genus Frontonia was assessed according to 18S rRNA gene sequencing. Comments on the biodiversity of this genus were added according to past and recent literature.}, }
@article {pmid30626679, year = {2019}, author = {Dunigan, DD and Al-Sammak, M and Al-Ameeli, Z and Agarkova, IV and DeLong, JP and Van Etten, JL}, title = {Chloroviruses Lure Hosts through Long-Distance Chemical Signaling.}, journal = {Journal of virology}, volume = {93}, number = {7}, pages = {}, pmid = {30626679}, issn = {1098-5514}, mesh = {DNA Viruses/*genetics ; Host Microbial Interactions/*genetics ; Phycodnaviridae/*genetics ; Population Dynamics ; }, abstract = {Chloroviruses exist in aquatic systems around the planet and they infect certain eukaryotic green algae that are mutualistic endosymbionts in a variety of protists and metazoans. Natural chlorovirus populations are seasonally dynamic, but the precise temporal changes in these populations and the mechanisms that underlie them have heretofore been unclear. We recently reported the novel concept that predator/prey-mediated virus activation regulates chlorovirus population dynamics, and in the current study, we demonstrate virus-packaged chemotactic modulation of prey behavior.IMPORTANCE Viruses have not previously been reported to act as chemotactic/chemoattractive agents. Rather, viruses as extracellular entities are generally viewed as non-metabolically active spore-like agents that await further infection events upon collision with appropriate host cells. That a virus might actively contribute to its fate via chemotaxis and change the behavior of an organism independent of infection is unprecedented.}, }
@article {pmid30620733, year = {2019}, author = {Garcia, GA and Sylvestre, G and Aguiar, R and da Costa, GB and Martins, AJ and Lima, JBP and Petersen, MT and Lourenço-de-Oliveira, R and Shadbolt, MF and Rašić, G and Hoffmann, AA and Villela, DAM and Dias, FBS and Dong, Y and O'Neill, SL and Moreira, LA and Maciel-de-Freitas, R}, title = {Matching the genetics of released and local Aedes aegypti populations is critical to assure Wolbachia invasion.}, journal = {PLoS neglected tropical diseases}, volume = {13}, number = {1}, pages = {e0007023}, pmid = {30620733}, issn = {1935-2735}, mesh = {Aedes/*drug effects/genetics/*virology ; Animals ; Arboviruses/*growth &amp; development ; Biological Control Agents ; Brazil ; DNA, Mitochondrial/genetics ; Female ; Insecticide Resistance/*genetics ; Male ; Mosquito Vectors/virology ; Pest Control, Biological/*methods ; Pyrethrins/pharmacology ; Wolbachia/*growth &amp; development ; }, abstract = {BACKGROUND: Traditional vector control approaches such as source reduction and insecticide spraying have limited effect on reducing Aedes aegypti population. The endosymbiont Wolbachia is pointed as a promising tool to mitigate arbovirus transmission and has been deployed worldwide. Models predict a rapid increase on the frequency of Wolbachia-positive Ae. aegypti mosquitoes in local settings, supported by cytoplasmic incompatibility (CI) and high maternal transmission rate associated with the wMelBr strain.<br><br>Wolbachia wMelBr strain was released for 20 consecutive weeks after receiving >87% approval of householders of the isolated community of Tubiacanga, Rio de Janeiro. wMelBr frequency plateued~40% during weeks 7-19, peaked 65% but dropped as releases stopped. A high (97.56%) maternal transmission was observed. Doubling releases and deploying mosquitoes with large wing length and low laboratory mortality produced no detectable effects on invasion trend. By investigating the lab colony maintenance procedures backwardly, pyrethroid resistant genotypes in wMelBr decreased from 68% to 3.5% after 17 generations. Therefore, we initially released susceptible mosquitoes in a local population highly resistant to pyrethroids which, associated with the over use of insecticides by householders, ended jeopardizing Wolbachia invasion. A new strain (wMelRio) was produced after backcrossing wMelBr females with males from field to introduce mostly pyrethroid resistance alleles. The new strain increased mosquito survival but produced relevant negative effects on Ae. aegypti fecundity traits, reducing egg clutche size and egg hatch. Despite the cost on fitness, wMelRio successful established where wMelBr failed, revealing that matching the local population genetics, especially insecticide resistance background, is critical to achieve invasion.<br><br>CONCLUSIONS/SIGNIFICANCE: Local householders support was constantly high, reaching 90% backing on the second release (wMelRio strain). Notwithstanding the drought summer, the harsh temperature recorded (daily average above 30&#xb0;C) did not seem to affect the expression of maternal transmission of wMel on a Brazilian background. Wolbachia deployment should match the insecticide resistance profile of the wild population to achieve invasion. Considering pyrethroid-resistance is a widely distributed phenotype in natural Ae. aegypti populations, future Wolbachia deployments must pay special attention in maintaining insecticide resistance in lab colonies for releases.}, }
@article {pmid30619600, year = {2018}, author = {Li, S and Liu, D and Zhang, R and Zhai, Y and Huang, X and Wang, D and Shi, X}, title = {Effects of a presumably protective endosymbiont on life-history characters and their plasticity for its host aphid on three plants.}, journal = {Ecology and evolution}, volume = {8}, number = {24}, pages = {13004-13013}, pmid = {30619600}, issn = {2045-7758}, abstract = {Hamiltonella defensa is well known for its protective roles against parasitoids for its aphid hosts, but its functional roles in insect-plant interactions are less understood. Thus, the impact of H. defensa infections on life-history characters and the underlying genetic variation for the grain aphid, Sitobion avenae (Fabricius), was explored on three plants (i.e., wheat, oat, and rye). Compared to cured lines, H. defensa infected lines of S. avenae had lower fecundity on wheat and oat, but not on rye, suggesting an infection cost for the aphid on susceptible host plants. However, when tested on rye, the infected lines showed a shorter developmental time for the nymphal stage than corresponding cured lines, showing some benefit for S. avenae carrying the endosymbiont on resistant host plants. The infection of H. defensa altered genetic variation underlying its host S. avenea's life-history characters, which was shown by differences in heritabilities and genetic correlations of life-history characters between S. avenae lines infected and cured of the endosymbiont. This was further substantiated by disparity in G-matrices of their life-history characters for the two types of aphid lines. The G-matrices for life-history characters of aphid lines infected with and cured of H. defensa were significantly different from each other on rye, but not on oat, suggesting strong plant-dependent effects. The developmental durations of infected S. avenae lines showed a lower plasticity compared with those of corresponding cured lines, and this could mean higher adaptability for the infected lines.Overall, our results showed novel functional roles of a common secondary endosymbiont (i.e., H. defensa) in plant-insect interactions, and its infections could have significant consequences for the evolutionary ecology of its host insect populations in nature.}, }
@article {pmid30619179, year = {2018}, author = {Regier, Y and Komma, K and Weigel, M and Pulliainen, AT and Göttig, S and Hain, T and Kempf, VAJ}, title = {Microbiome Analysis Reveals the Presence of Bartonella spp. and Acinetobacter spp. in Deer Keds (Lipoptena cervi).}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {3100}, pmid = {30619179}, issn = {1664-302X}, abstract = {The deer ked (Lipoptena cervi) is distributed in Europe, North America, and Siberia and mainly infests cervids as roe deer, fallow deer, and moose. From a one health perspective, deer keds occasionally bite other animals or humans and are a potential vector for Bartonella schoenbuchensis. This bacterium belongs to a lineage of ruminant-associated Bartonella spp. and is suspected to cause dermatitis and febrile diseases in humans. In this study, we analyzed the microbiome from 130 deer keds collected from roe deer, fallow deer and humans in the federal states of Hesse, Baden-Wuerttemberg, and Brandenburg, Germany. Endosymbiontic Arsenophonus spp. and Bartonella spp. represented the biggest portion (~90%) of the microbiome. Most Bartonella spp. (n = 93) were confirmed to represent B. schoenbuchensis. In deer keds collected from humans, no Bartonella spp. were detected. Furthermore, Acinetobacter spp. were present in four samples, one of those was confirmed to represent A. baumannii. These data suggest that deer keds harbor only a very narrow spectrum of bacteria which are potentially pathogenic for animals of humans.}, }
@article {pmid30617214, year = {2019}, author = {Brenner, WG and Mader, M and Müller, NA and Hoenicka, H and Schroeder, H and Zorn, I and Fladung, M and Kersten, B}, title = {High Level of Conservation of Mitochondrial RNA Editing Sites Among Four Populus Species.}, journal = {G3 (Bethesda, Md.)}, volume = {9}, number = {3}, pages = {709-717}, pmid = {30617214}, issn = {2160-1836}, mesh = {Gene Expression Profiling ; Mitochondria/genetics/metabolism ; Phylogeny ; *Polymorphism, Single Nucleotide ; Populus/*genetics/metabolism ; *RNA Editing ; RNA, Mitochondrial/*metabolism ; RNA, Plant/metabolism ; Sequence Analysis, RNA ; }, abstract = {RNA editing occurs in the endosymbiont organelles of higher plants as C-to-U conversions of defined nucleotides. The availability of large quantities of RNA sequencing data makes it possible to identify RNA editing sites and to quantify their editing extent. We have investigated RNA editing in 34 protein-coding mitochondrial transcripts of four Populus species, a genus noteworthy for its remarkably small number of RNA editing sites compared to other angiosperms. 27 of these transcripts were subject to RNA editing in at least one species. In total, 355 RNA editing sites were identified with high confidence, their editing extents ranging from 10 to 100%. The most heavily edited transcripts were ccmB with the highest density of RNA editing sites (53.7 sites / kb) and ccmFn with the highest number of sites (39 sites). Most of the editing events are at position 1 or 2 of the codons, usually altering the encoded amino acid, and are highly conserved among the species, also with regard to their editing extent. However, one SNP was found in the newly sequenced and annotated mitochondrial genome of P. alba resulting in the loss of an RNA editing site compared to P. tremula and P. davidiana This SNP causes a C-to-T transition and an amino acid exchange from Ser to Phe, highlighting the widely discussed role of RNA editing in compensating mutations.}, }
@article {pmid30617067, year = {2019}, author = {Hong, WD and Benayoud, F and Nixon, GL and Ford, L and Johnston, KL and Clare, RH and Cassidy, A and Cook, DAN and Siu, A and Shiotani, M and Webborn, PJH and Kavanagh, S and Aljayyoussi, G and Murphy, E and Steven, A and Archer, J and Struever, D and Frohberger, SJ and Ehrens, A and Hübner, MP and Hoerauf, A and Roberts, AP and Hubbard, ATM and Tate, EW and Serwa, RA and Leung, SC and Qie, L and Berry, NG and Gusovsky, F and Hemingway, J and Turner, JD and Taylor, MJ and Ward, SA and O'Neill, PM}, title = {AWZ1066S, a highly specific anti-Wolbachia drug candidate for a short-course treatment of filariasis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {116}, number = {4}, pages = {1414-1419}, pmid = {30617067}, issn = {1091-6490}, support = {MC_PC_16052/MRC_/Medical Research Council/United Kingdom ; MC_PC_17167/MRC_/Medical Research Council/United Kingdom ; MR/R025401/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Elephantiasis, Filarial/drug therapy/microbiology ; Female ; Male ; Mice ; Mice, SCID ; Onchocerciasis/drug therapy/microbiology ; Pyrimidines/pharmacology ; Quinazolines/pharmacology ; Wolbachia/*drug effects ; }, abstract = {Onchocerciasis and lymphatic filariasis are two neglected tropical diseases that together affect ∼157 million people and inflict severe disability. Both diseases are caused by parasitic filarial nematodes with elimination efforts constrained by the lack of a safe drug that can kill the adult filaria (macrofilaricide). Previous proof-of-concept human trials have demonstrated that depleting >90% of the essential nematode endosymbiont bacterium, Wolbachia, using antibiotics, can lead to permanent sterilization of adult female parasites and a safe macrofilaricidal outcome. AWZ1066S is a highly specific anti-Wolbachia candidate selected through a lead optimization program focused on balancing efficacy, safety and drug metabolism/pharmacokinetic (DMPK) features of a thienopyrimidine/quinazoline scaffold derived from phenotypic screening. AWZ1066S shows superior efficacy to existing anti-Wolbachia therapies in validated preclinical models of infection and has DMPK characteristics that are compatible with a short therapeutic regimen of 7 days or less. This candidate molecule is well-positioned for onward development and has the potential to make a significant impact on communities affected by filariasis.}, }
@article {pmid30615101, year = {2019}, author = {Sen, D and Paul, K and Saha, C and Mukherjee, G and Nag, M and Ghosh, S and Das, A and Seal, A and Tripathy, S}, title = {A unique life-strategy of an endophytic yeast Rhodotorula mucilaginosa JGTA-S1-a comparative genomics viewpoint.}, journal = {DNA research : an international journal for rapid publication of reports on genes and genomes}, volume = {26}, number = {2}, pages = {131-146}, pmid = {30615101}, issn = {1756-1663}, mesh = {Bacteria/metabolism ; *Endophytes ; *Genome, Fungal ; Genomics ; *Metabolic Networks and Pathways ; Nitrogen/metabolism ; Pseudomonas stutzeri/metabolism ; Rhodotorula/*genetics/metabolism/physiology ; Sequence Analysis, DNA ; *Symbiosis ; Typhaceae ; }, abstract = {Endophytic yeasts of genus Rhodotorula are gaining importance for their ability to improve plant growth. The nature of their interaction with plants, however, remains unknown. Rhodotorula mucilaginosa JGTA-S1 was isolated as an endophyte of Typha angustifolia and promoted growth in the host. To investigate the life-strategy of the yeast from a genomics perspective, we used Illumina and Oxford Nanopore reads to generate a high-quality annotated draft assembly of JGTA-S1 and compared its genome to three other Rhodotorula yeasts and the close relative Rhodosporidium toruloides. JGTA-S1 is a haploid yeast possessing several genes potentially facilitating its endophytic lifestyle such as those responsible for solubilizing phosphate and producing phytohormones. An intact mating-locus in JGTA-S1 raised the possibility of a yet unknown sexual reproductive cycle in Rhodotorula yeasts. Additionally, JGTA-S1 had functional anti-freezing genes and was also unique in lacking a functional nitrate-assimilation pathway-a feature that is associated with obligate biotrophs. Nitrogen-fixing endobacteria were found within JGTA-S1 that may circumvent this defective N-metabolism. JGTA-S1 genome data coupled with experimental evidence give us an insight into the nature of its beneficial interaction with plants.}, }
@article {pmid30613848, year = {2019}, author = {Ye, S and Bhattacharjee, M and Siemann, E}, title = {Thermal Tolerance in Green Hydra: Identifying the Roles of Algal Endosymbionts and Hosts in a Freshwater Holobiont Under Stress.}, journal = {Microbial ecology}, volume = {77}, number = {2}, pages = {537-545}, pmid = {30613848}, issn = {1432-184X}, mesh = {Animals ; Chlorophyta/*physiology ; Fresh Water/chemistry/parasitology ; Hot Temperature ; Hydra/*parasitology/physiology ; Stress, Physiological ; *Symbiosis ; }, abstract = {It has been proposed that holobionts (host-symbiont units) could swap endosymbionts, rapidly alter the hologenome (host plus symbiont genome), and increase their stress tolerance. However, experimental tests of individual and combined contributions of hosts and endosymbionts to holobiont stress tolerance are needed to test this hypothesis. Here, we used six green hydra (Hydra viridissima) strains to tease apart host (hydra) and symbiont (algae) contributions to thermal tolerance. Heat shock experiments with (1) hydra with their original symbionts, (2) aposymbiotic hydra (algae removed), (3) novel associations (a single hydra strain hosting different algae individually), and (4) control hydra (aposymbiotic hydra re-associated with their original algae) showed high variation in thermal tolerance in each group. Relative tolerances of strains were the same within original, aposymbiotic, and control treatments, but reversed in the novel associations group. Aposymbiotic hydra had similar or higher thermal tolerance than hydra with algal symbionts. Selection on the holobiont appears to be stronger than on either partner alone, suggesting endosymbiosis could become an evolutionary trap under climate change. Our results suggest that green hydra thermal tolerance is strongly determined by the host, with a smaller, non-positive role for the algal symbiont. Once temperatures exceed host tolerance limits, swapping symbionts is unlikely to allow these holobionts to persist. Rather, increases in host tolerance through in situ adaptation or migration of pre-adapted host strains appear more likely to increase local thermal tolerance. Overall, our results indicate green hydra is a valuable system for studying aquatic endosymbiosis under changing environmental conditions, and demonstrate how the host and the endosymbiont contribute to holobiont stress tolerance.}, }
@article {pmid30611207, year = {2019}, author = {Kamm, K and Schierwater, B and DeSalle, R}, title = {Innate immunity in the simplest animals - placozoans.}, journal = {BMC genomics}, volume = {20}, number = {1}, pages = {5}, pmid = {30611207}, issn = {1471-2164}, mesh = {Animals ; Genome/*immunology ; Immunity, Innate/*genetics ; Invertebrates/genetics/immunology ; *Phylogeny ; Placozoa/genetics/*immunology ; Symbiosis/genetics/immunology ; }, abstract = {BACKGROUND: Innate immunity provides the core recognition system in animals for preventing infection, but also plays an important role in managing the relationship between an animal host and its symbiont. Most of our knowledge about innate immunity stems from a few animal model systems, but substantial variation between metazoan phyla has been revealed by comparative genomic studies. The exploration of more taxa is still needed to better understand the evolution of immunity related mechanisms. Placozoans are morphologically the simplest organized metazoans and the association between these enigmatic animals and their rickettsial endosymbionts has recently been elucidated. Our analyses of the novel placozoan nuclear genome of Trichoplax sp. H2 and its associated rickettsial endosymbiont genome clearly pointed to a mutualistic and co-evolutionary relationship. This discovery raises the question of how the placozoan holobiont manages symbiosis and, conversely, how it defends against harmful microorganisms. In this study, we examined the annotated genome of Trichoplax sp. H2 for the presence of genes involved in innate immune recognition and downstream signaling.<br><br>RESULTS: A rich repertoire of genes belonging to the Toll-like and NOD-like receptor pathways, to scavenger receptors and to secreted fibrinogen-related domain genes was identified in the genome of Trichoplax sp. H2. Nevertheless, the innate immunity related pathways in placozoans deviate in several instances from well investigated vertebrates and invertebrates. While true Toll- and NOD-like receptors are absent, the presence of many genes of the downstream signaling cascade suggests at least primordial Toll-like receptor signaling in Placozoa. An abundance of scavenger receptors, fibrinogen-related domain genes and Apaf-1 genes clearly constitutes an expansion of the immunity related gene repertoire specific to Placozoa.<br><br>CONCLUSIONS: The found wealth of immunity related genes present in Placozoa is surprising and quite striking in light of the extremely simple placozoan body plan and their sparse cell type makeup. Research is warranted to reveal how Placozoa utilize this immune repertoire to manage and maintain their associated microbiota as well as to fend-off pathogens.}, }
@article {pmid30609847, year = {2019}, author = {Bustamante-Brito, R and Vera-Ponce de León, A and Rosenblueth, M and Martínez-Romero, JC and Martínez-Romero, E}, title = {Metatranscriptomic Analysis of the Bacterial Symbiont Dactylopiibacterium carminicum from the Carmine Cochineal Dactylopius coccus (Hemiptera: Coccoidea: Dactylopiidae).}, journal = {Life (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, pmid = {30609847}, issn = {2075-1729}, abstract = {The scale insect Dactylopius coccus produces high amounts of carminic acid, which has historically been used as a pigment by pre-Hispanic American cultures. Nowadays carmine is found in food, cosmetics, and textiles. Metagenomic approaches revealed that Dactylopius spp. cochineals contain two Wolbachia strains, a betaproteobacterium named Candidatus Dactylopiibacterium carminicum and Spiroplasma, in addition to different fungi. We describe here a transcriptomic analysis indicating that Dactylopiibacterium is metabolically active inside the insect host, and estimate that there are over twice as many Dactylopiibacterium cells in the hemolymph than in the gut, with even fewer in the ovary. Albeit scarce, the transcripts in the ovaries support the presence of Dactylopiibacterium in this tissue and a vertical mode of transmission. In the cochineal, Dactylopiibacterium may catabolize plant polysaccharides, and be active in carbon and nitrogen provisioning through its degradative activity and by fixing nitrogen. In most insects, nitrogen-fixing bacteria are found in the gut, but in this study they are shown to occur in the hemolymph, probably delivering essential amino acids and riboflavin to the host from nitrogen substrates derived from nitrogen fixation.}, }
@article {pmid30608924, year = {2019}, author = {Makki, A and Rada, P and Žárský, V and Kereïche, S and Kováčik, L and Novotný, M and Jores, T and Rapaport, D and Tachezy, J}, title = {Triplet-pore structure of a highly divergent TOM complex of hydrogenosomes in Trichomonas vaginalis.}, journal = {PLoS biology}, volume = {17}, number = {1}, pages = {e3000098}, pmid = {30608924}, issn = {1545-7885}, mesh = {Carrier Proteins/genetics/*metabolism/physiology ; Membrane Proteins/metabolism ; Membrane Transport Proteins/metabolism ; Mitochondria/metabolism ; Mitochondrial Membrane Transport Proteins/*metabolism ; Mitochondrial Precursor Protein Import Complex Proteins ; Organelles ; Phylogeny ; Protein Transport/physiology ; Trichomonas vaginalis/*metabolism/pathogenicity/physiology ; }, abstract = {Mitochondria originated from proteobacterial endosymbionts, and their transition to organelles was tightly linked to establishment of the protein import pathways. The initial import of most proteins is mediated by the translocase of the outer membrane (TOM). Although TOM is common to all forms of mitochondria, an unexpected diversity of subunits between eukaryotic lineages has been predicted. However, experimental knowledge is limited to a few organisms, and so far, it remains unsettled whether the triplet-pore or the twin-pore structure is the generic form of TOM complex. Here, we analysed the TOM complex in hydrogenosomes, a metabolically specialised anaerobic form of mitochondria found in the excavate Trichomonas vaginalis. We demonstrate that the highly divergent β-barrel T. vaginalis TOM (TvTom)40-2 forms a translocation channel to conduct hydrogenosomal protein import. TvTom40-2 is present in high molecular weight complexes, and their analysis revealed the presence of four tail-anchored (TA) proteins. Two of them, Tom36 and Tom46, with heat shock protein (Hsp)20 and tetratricopeptide repeat (TPR) domains, can bind hydrogenosomal preproteins and most likely function as receptors. A third subunit, Tom22-like protein, has a short cis domain and a conserved Tom22 transmembrane segment but lacks a trans domain. The fourth protein, hydrogenosomal outer membrane protein 19 (Homp19) has no known homology. Furthermore, our data indicate that TvTOM is associated with sorting and assembly machinery (Sam)50 that is involved in β-barrel assembly. Visualisation of TvTOM by electron microscopy revealed that it forms three pores and has an unconventional skull-like shape. Although TvTOM seems to lack Tom7, our phylogenetic profiling predicted Tom7 in free-living excavates. Collectively, our results suggest that the triplet-pore TOM complex, composed of three conserved subunits, was present in the last common eukaryotic ancestor (LECA), while receptors responsible for substrate binding evolved independently in different eukaryotic lineages.}, }
@article {pmid30603945, year = {2018}, author = {Pavlova, LV}, title = {First Finding of Representatives of the Eccrinida Order in the Digestive Tract of King Crab Specie from the Barents Sea.}, journal = {Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections}, volume = {483}, number = {1}, pages = {231-234}, pmid = {30603945}, issn = {1608-3105}, mesh = {Animals ; Anomura/*anatomy &amp; histology ; Gastrointestinal Tract/*anatomy &amp; histology ; *Symbiosis ; }, abstract = {This is the first report on the finding of large intra-intestinal symbionts belonging to the order Eccrinida in crab-like decapod crustaceans of the family Lithodidae, Paralithodes camtschaticus and Lithodes maja, inhabiting the Barents Sea. Studies have been regularly conducted since the early 2000s in Kola Bay and in one of the inlets of the Eastern Murman Coast. Since 2005, Eccrinida representatives (presumably, a new species of the genus Arundinula) have been found in the guts of the red king crab. A brief description of the endosymbionts and data on their frequency of occurrence are presented. The possible reasons for the distribution of eccrinids in the crab-like decapod crustaceans of the Barents Sea are discussed.}, }
@article {pmid30602718, year = {2019}, author = {Clare, RH and Bardelle, C and Harper, P and Hong, WD and Börjesson, U and Johnston, KL and Collier, M and Myhill, L and Cassidy, A and Plant, D and Plant, H and Clark, R and Cook, DAN and Steven, A and Archer, J and McGillan, P and Charoensutthivarakul, S and Bibby, J and Sharma, R and Nixon, GL and Slatko, BE and Cantin, L and Wu, B and Turner, J and Ford, L and Rich, K and Wigglesworth, M and Berry, NG and O'Neill, PM and Taylor, MJ and Ward, SA}, title = {Industrial scale high-throughput screening delivers multiple fast acting macrofilaricides.}, journal = {Nature communications}, volume = {10}, number = {1}, pages = {11}, pmid = {30602718}, issn = {2041-1723}, support = {MC_PC_17167/MRC_/Medical Research Council/United Kingdom ; MR/R025401/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Aedes ; Animals ; Cell Line ; *Drug Discovery ; Filaricides/*analysis ; *High-Throughput Screening Assays ; Wolbachia ; }, abstract = {Nematodes causing lymphatic filariasis and onchocerciasis rely on their bacterial endosymbiont, Wolbachia, for survival and fecundity, making Wolbachia a promising therapeutic target. Here we perform a high-throughput screen of AstraZeneca's 1.3 million in-house compound library and identify 5 novel chemotypes with faster in vitro kill rates (<2 days) than existing anti-Wolbachia drugs that cure onchocerciasis and lymphatic filariasis. This industrial scale anthelmintic neglected tropical disease (NTD) screening campaign is the result of a partnership between the Anti-Wolbachia consortium (A∙WOL) and AstraZeneca. The campaign was informed throughout by rational prioritisation and triage of compounds using cheminformatics to balance chemical diversity and drug like properties reducing the chance of attrition from the outset. Ongoing development of these multiple chemotypes, all with superior time-kill kinetics than registered antibiotics with anti-Wolbachia activity, has the potential to improve upon the current therapeutic options and deliver improved, safer and more selective macrofilaricidal drugs.}, }
@article {pmid30602581, year = {2019}, author = {Hall, RJ and Flanagan, LA and Bottery, MJ and Springthorpe, V and Thorpe, S and Darby, AC and Wood, AJ and Thomas, GH}, title = {A Tale of Three Species: Adaptation of Sodalis glossinidius to Tsetse Biology, Wigglesworthia Metabolism, and Host Diet.}, journal = {mBio}, volume = {10}, number = {1}, pages = {}, pmid = {30602581}, issn = {2150-7511}, support = {//Wellcome Trust/United Kingdom ; BB/M011151/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/N010426/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/J017698/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; WT095024MA//Wellcome Trust/United Kingdom ; }, mesh = {*Adaptation, Physiological ; Animals ; Carbon/metabolism ; Culture Media/chemistry ; Disease Vectors ; Energy Metabolism ; Enterobacteriaceae/*growth &amp; development/*metabolism ; *Feeding Behavior ; Glucose/metabolism ; Glutamates/metabolism ; Nitrogen/metabolism ; *Symbiosis ; Thiamine/metabolism ; Tsetse Flies/*microbiology/*physiology ; }, abstract = {The tsetse fly is the insect vector for the Trypanosoma brucei parasite, the causative agent of human African trypanosomiasis. The colonization and spread of the trypanosome correlate positively with the presence of a secondary symbiotic bacterium, Sodalis glossinidius The metabolic requirements and interactions of the bacterium with its host are poorly understood, and herein we describe a metabolic model of S. glossinidius metabolism. The model enabled the design and experimental verification of a defined medium that supports S. glossinidius growth ex vivo This has been used subsequently to analyze in vitro aspects of S. glossinidius metabolism, revealing multiple unique adaptations of the symbiont to its environment. Continued dependence on a sugar, and the importance of the chitin monomer N-acetyl-d-glucosamine as a carbon and energy source, suggests adaptation to host-derived molecules. Adaptation to the amino acid-rich blood diet is revealed by a strong dependence on l-glutamate as a source of carbon and nitrogen and by the ability to rescue a predicted l-arginine auxotrophy. Finally, the selective loss of thiamine biosynthesis, a vitamin provided to the host by the primary symbiont Wigglesworthia glossinidia, reveals an intersymbiont dependence. The reductive evolution of S. glossinidius to exploit environmentally derived metabolites has resulted in multiple weaknesses in the metabolic network. These weaknesses may become targets for reagents that inhibit S. glossinidius growth and aid the reduction of trypanosomal transmission.IMPORTANCE Human African trypanosomiasis is caused by the Trypanosoma brucei parasite. The tsetse fly vector is of interest for its potential to prevent disease spread, as it is essential for T. brucei life cycle progression and transmission. The tsetse's mutualistic endosymbiont Sodalis glossinidius has a link to trypanosome establishment, providing a disease control target. Here, we describe a new, experimentally verified model of S. glossinidius metabolism. This model has enabled the development of a defined growth medium that was used successfully to test aspects of S. glossinidius metabolism. We present S. glossinidius as uniquely adapted to life in the tsetse, through its reliance on the blood diet and host-derived sugars. Additionally, S. glossinidius has adapted to the tsetse's obligate symbiont Wigglesworthia glossinidia by scavenging a vitamin it produces for the insect. This work highlights the use of metabolic modeling to design defined growth media for symbiotic bacteria and may provide novel inhibitory targets to block trypanosome transmission.}, }
@article {pmid30598000, year = {2018}, author = {Mannaa, M and Park, I and Seo, YS}, title = {Genomic Features and Insights into the Taxonomy, Virulence, and Benevolence of Plant-Associated Burkholderia Species.}, journal = {International journal of molecular sciences}, volume = {20}, number = {1}, pages = {}, pmid = {30598000}, issn = {1422-0067}, mesh = {Burkholderia/classification/*genetics/pathogenicity ; Crops, Agricultural/*microbiology ; *Genome, Bacterial ; *Host-Pathogen Interactions ; Phylogeny ; Symbiosis ; }, abstract = {The members of the Burkholderia genus are characterized by high versatility and adaptability to various ecological niches. With the availability of the genome sequences of numerous species of Burkholderia, many studies have been conducted to elucidate the unique features of this exceptional group of bacteria. Genomic and metabolic plasticity are common among Burkholderia species, as evidenced by their relatively large multi-replicon genomes that are rich in insertion sequences and genomic islands and contain a high proportion of coding regions. Such unique features could explain their adaptability to various habitats and their versatile lifestyles, which are reflected in a multiplicity of species including free-living rhizospheric bacteria, plant endosymbionts, legume nodulators, and plant pathogens. The phytopathogenic Burkholderia group encompasses several pathogens representing threats to important agriculture crops such as rice. Contrarily, plant-beneficial Burkholderia have also been reported, which have symbiotic and growth-promoting roles. In this review, the taxonomy of Burkholderia is discussed emphasizing the recent updates and the contributions of genomic studies to precise taxonomic positioning. Moreover, genomic and functional studies on Burkholderia are reviewed and insights are provided into the mechanisms underlying the virulence and benevolence of phytopathogenic and plant-beneficial Burkholderia, respectively, on the basis of cutting-edge knowledge.}, }
@article {pmid30595344, year = {2019}, author = {Gangwar, M and Jha, R and Goyal, M and Srivastava, M}, title = {Immunogenicity and protective efficacy of Recombinase A from Wolbachia endosymbiont of filarial nematode Brugia malayi (wBmRecA).}, journal = {Vaccine}, volume = {37}, number = {4}, pages = {571-580}, doi = {10.1016/j.vaccine.2018.12.015}, pmid = {30595344}, issn = {1873-2518}, mesh = {Animals ; Antibodies, Helminth/blood ; B-Lymphocytes/immunology ; Brugia malayi/*microbiology ; CD4-Positive T-Lymphocytes/immunology ; CD8-Positive T-Lymphocytes/immunology ; Cloning, Molecular ; Cytokines/immunology ; Elephantiasis, Filarial/immunology/prevention &amp; control ; Female ; *Immunogenicity, Vaccine ; Immunoglobulin G/blood ; Mice ; Rec A Recombinases/genetics/*immunology ; Spleen/immunology ; Wolbachia/*enzymology ; }, abstract = {Lymphatic filariasis causes global morbidity. Wolbachia, an endo-symbiotic intracellular bacterium of the filarial nematode helps in their growth and development, regulates fecundity in female worms and contributes to the immunopathogenesis of the disease. However, genes and proteins of Wolbachia that may act as putative vaccine candidates are not known. In this study, we cloned recombinase-A protein of Wolbachia from Brugia malayi (wBmRecA) and carried out its detailed biochemical and immunological characterization. Bioinformatics analysis, circular dichroism and fluorescence spectral studies showed significant sequence and structural similarities between wBmRecA and RecA of other alpha-proteo- bacterial species. wBmRecA was ubiquitously expressed in all the three major life stages of B. malayi, including excretory-secretory products of the adult worm. In silico studies suggested immunogenic potential of wBmRecA, and mice immunized with wBmRecA exhibited elevated levels of immunoglobulins IgG1, IgG2a, IgG2b and IgG3 in their serum along with increased percentages of CD4[+], CD8[+] T cells and CD19[+] B cells in their spleens. Notably, splenocytes from immunized mice showed increased m-RNA expression of T-bet, elevated proinflammatory cytokines IFN-γ and IL-12, while peritoneal MФs exhibited increased levels of iNOS, downregulated Arg-1 and secreted copious amounts of nitric oxide which contributed to severely impaired development of the infective larvae (Bm-L3). Interestingly, sera from immunized mice promoted significant cellular adherence and cytotoxicity against microfilariae and Bm-L3. Importantly, wBmRecA demonstrated strong immuno-reactivity with bancroftian sera from endemic normal individuals. These results suggest that wBmRecA is highly immunogenic, and should be explored further as a putative vaccine candidate against lymphatic filariasis.}, }
@article {pmid30581663, year = {2018}, author = {Mioduchowska, M and Czyż, MJ and Gołdyn, B and Kilikowska, A and Namiotko, T and Pinceel, T and Łaciak, M and Sell, J}, title = {Detection of bacterial endosymbionts in freshwater crustaceans: the applicability of non-degenerate primers to amplify the bacterial 16S rRNA gene.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e6039}, pmid = {30581663}, issn = {2167-8359}, abstract = {Bacterial endosymbionts of aquatic invertebrates remain poorly studied. This is at least partly due to a lack of suitable techniques and primers for their identification. We designed a pair of non-degenerate primers which enabled us to amplify a fragment of ca. 500 bp of the 16S rRNA gene from various known bacterial endosymbiont species. By using this approach, we identified four bacterial endosymbionts, two endoparasites and one uncultured bacterium in seven, taxonomically diverse, freshwater crustacean hosts from temporary waters across a wide geographical area. The overall efficiency of our new WOLBSL and WOLBSR primers for amplification of the bacterial 16S rRNA gene was 100%. However, if different bacterial species from one sample were amplified simultaneously, sequences were illegible, despite a good quality of PCR products. Therefore, we suggest using our primers at the first stage of bacterial endosymbiont identification. Subsequently, genus specific primers are recommended. Overall, in the era of next-generation sequencing our method can be used as a first simple and low-cost approach to identify potential microbial symbionts associated with freshwater crustaceans using simple Sanger sequencing. The potential to detected bacterial symbionts in various invertebrate hosts in such a way will facilitate studies on host-symbiont interactions and coevolution.}, }
@article {pmid30560551, year = {2018}, author = {Maleki-Ravasan, N and Akhavan, N and Raz, A and Jafari, M and Zakeri, S and Dinparast Djadid, N}, title = {Co-occurrence of pederin-producing and Wolbachia endobacteria in Paederus fuscipes Curtis, 1840 (Coleoptera: Staphilinidae) and its evolutionary consequences.}, journal = {MicrobiologyOpen}, volume = {8}, number = {7}, pages = {e777}, pmid = {30560551}, issn = {2045-8827}, abstract = {The dual occurrence of Pseudomonas-like and Wolbachia endobacteria has not been investigated in the Pederus beetles yet. We investigated pederin-producing bacteria (PPB) infection in Paederus fuscipes specimens from the southern margins of the Caspian Sea by designed genus-specific (OprF) and species-specific (16S rRNA) primers. Wolbachia infection was studied through a nested-PCR assay of Wolbachia surface protein (wsp) gene. Of the 125 analyzed beetles, 42 females (82.35%) and 15 males (20.27%) were positive to PPB infection; this is the first study reporting male P. fuscipes infection to PPB. Wolbachia infection was found in 45 female (88.23%) and 50 male (67.57%) analyzed beetles. Surprisingly, a number of 36 females (70.59%) and 13 males (17.57%) were found to be infected with both PPB and Wolbachia endosymbionts. In general, population infection rates to PPB and Wolbachia were determined to be 45.6% and 76%, respectively. The infection rates of female beetles to PPB and PPB-Wolbachia were significantly higher than males. In Paederus species, only female beetles shelter PPB and the discovery of this bacterium in adult males may reflect their cannibalistic behavior on the contaminated stages. Phylogenetic analysis showed that the sequences of OprF gene were unique among Pseudomonas spp.; however, sequences of 16S rRNA gene were related to the PPB of Pederus species. The co-occurrence and random distribution of these endobacteria may imply putative tripartite interactions among PPB, Wolbachia, and Paederus. In order to elucidate these possible tripartite interactions, further studies are required even at gender level.}, }
@article {pmid30557379, year = {2018}, author = {Wang, X and Li, C and Wang, M and Zheng, P}, title = {Stable isotope signatures and nutritional sources of some dominant species from the PACManus hydrothermal area and the Desmos caldera.}, journal = {PloS one}, volume = {13}, number = {12}, pages = {e0208887}, pmid = {30557379}, issn = {1932-6203}, mesh = {Animals ; Carbon Isotopes/*analysis ; *Crustacea ; *Ecosystem ; Geologic Sediments ; *Hydrothermal Vents ; Nitrogen Isotopes/*analysis ; }, abstract = {Deep-sea hydrothermal vents in the western Pacific are increasingly explored for potential mineral extraction. The study of the composition of the food web plays an important guiding role in the ecological protection and restoration of potential mining areas. The general picture of the nutritional sources of species should be established to assess the potential impacts of future mining activities on the biological composition and food sources. To provide basic information, we analyzed the carbon and nitrogen stable isotope ratios of the dominant macrofauna (mussels, commensal scale worms, crustaceans, gastropods, and vestimentiferans) at three different sites in the PACManus hydrothermal area and the Desmos caldera. The δ13C ratio was significantly different between species: mussels and commensal scale worms showed lighter δ13C ratios, whereas crustaceans showed heavier ratios. In terms of δ15N, mussels had the lowest values and the crustaceans had the highest values. By taking into account these stable isotope signatures, we were able to develop inferences of the food sources for vent community organisms. We found that the food web was based on various species of chemoautotrophic bacteria. Mussels appeared to rely primarily on sulfur-based endosymbionts, which use the Calvin-Benson-Bassham (CBB) cycle and RuBisCO form I as the CO2-fixing enzyme. Commensal polychaetes mostly obtained their nutrition from their hosts. Crustacean species were omnivorous, feeding on chemosynthetic bacteria, sedimentary debris, or even animals according to the local environment. In contrast, gastropods relied mainly on symbiotic bacteria with some supplementary consumption of detritus. Vestimentiferans obtained food from symbiotic bacteria using the RuBisCO form II enzyme in the CBB cycle and may have several symbionts using different fixation pathways. Although most macrofauna relied on symbiotic chemoautotrophic bacteria, our study suggested a closer trophic relationship between animals. Therefore, to evaluate the potential impacts of deep sea mining, it is necessary to study the cascade effects on the food web of the whole ecosystem. Before exploiting deep-sea resources, further systematic investigations concerning the protection of deep-sea ecosystems are necessary.}, }
@article {pmid30552831, year = {2019}, author = {Manzello, DP and Matz, MV and Enochs, IC and Valentino, L and Carlton, RD and Kolodziej, G and Serrano, X and Towle, EK and Jankulak, M}, title = {Role of host genetics and heat-tolerant algal symbionts in sustaining populations of the endangered coral Orbicella faveolata in the Florida Keys with ocean warming.}, journal = {Global change biology}, volume = {25}, number = {3}, pages = {1016-1031}, doi = {10.1111/gcb.14545}, pmid = {30552831}, issn = {1365-2486}, mesh = {Alveolata/genetics/*physiology ; Animals ; Anthozoa/genetics/*parasitology/*physiology ; Coral Reefs ; Florida ; Genetic Variation ; *Hot Temperature ; Oceans and Seas ; *Symbiosis ; Thermotolerance/genetics/*physiology ; }, abstract = {Identifying which factors lead to coral bleaching resistance is a priority given the global decline of coral reefs with ocean warming. During the second year of back-to-back bleaching events in the Florida Keys in 2014 and 2015, we characterized key environmental and biological factors associated with bleaching resilience in the threatened reef-building coral Orbicella faveolata. Ten reefs (five inshore, five offshore, 179 corals total) were sampled during bleaching (September 2015) and recovery (May 2016). Corals were genotyped with 2bRAD and profiled for algal symbiont abundance and type. O. faveolata at the inshore sites, despite higher temperatures, demonstrated significantly higher bleaching resistance and better recovery compared to offshore. The thermotolerant Durusdinium trenchii (formerly Symbiondinium trenchii) was the dominant endosymbiont type region-wide during initial (78.0% of corals sampled) and final (77.2%) sampling; >90% of the nonbleached corals were dominated by D. trenchii. 2bRAD host genotyping found no genetic structure among reefs, but inshore sites showed a high level of clonality. While none of the measured environmental parameters were correlated with bleaching, 71% of variation in bleaching resistance and 73% of variation in the proportion of D. trenchii was attributable to differences between genets, highlighting the leading role of genetics in shaping natural bleaching patterns. Notably, D. trenchii was rarely dominant in O. faveolata from the Florida Keys in previous studies, even during bleaching. The region-wide high abundance of D. trenchii was likely driven by repeated bleaching associated with the two warmest years on record for the Florida Keys (2014 and 2015). On inshore reefs in the Upper Florida Keys, O. faveolata was most abundant, had the highest bleaching resistance, and contained the most corals dominated by D. trenchii, illustrating a causal link between heat tolerance and ecosystem resilience with global change.}, }
@article {pmid30552191, year = {2019}, author = {Asselin, AK and Villegas-Ospina, S and Hoffmann, AA and Brownlie, JC and Johnson, KN}, title = {Contrasting Patterns of Virus Protection and Functional Incompatibility Genes in Two Conspecific Wolbachia Strains from Drosophila pandora.}, journal = {Applied and environmental microbiology}, volume = {85}, number = {5}, pages = {}, pmid = {30552191}, issn = {1098-5336}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; }, mesh = {Animal Diseases/microbiology ; Animals ; Bacterial Proteins/genetics/metabolism ; Base Sequence ; Cytoplasm/physiology ; DNA, Bacterial/genetics/isolation &amp; purification ; Dicistroviridae/genetics/metabolism/pathogenicity ; Drosophila/*microbiology/*virology ; Female ; Genes, Bacterial/genetics ; Genes, Viral ; Host-Pathogen Interactions ; Male ; Phenotype ; *Reproduction ; Symbiosis ; Wolbachia/genetics/*physiology/*virology ; }, abstract = {Wolbachia infections can present different phenotypes in hosts, including different forms of reproductive manipulation and antiviral protection, which may influence infection dynamics within host populations. In populations of Drosophila pandora two distinct Wolbachia strains coexist, each manipulating host reproduction: strain wPanCI causes cytoplasmic incompatibility (CI), whereas strain wPanMK causes male killing (MK). CI occurs when a Wolbachia-infected male mates with a female not infected with a compatible type of Wolbachia, leading to nonviable offspring. wPanMK can rescue wPanCI-induced CI but is unable to induce CI. The antiviral protection phenotypes provided by the wPanCI and wPanMK infections were characterized; the strains showed differential protection phenotypes, whereby cricket paralysis virus (CrPV)-induced mortality was delayed in flies infected with wPanMK but enhanced in flies infected with wPanCI compared to their respective Wolbachia-cured counterparts. Homologs of the cifA and cifB genes involved in CI identified in wPanMK and wPanCI showed a high degree of conservation; however, the CifB protein in wPanMK is truncated and is likely nonfunctional. The presence of a likely functional CifA in wPanMK and wPanMK's ability to rescue wPanCI-induced CI are consistent with the recent confirmation of CifA's involvement in CI rescue, and the absence of a functional CifB protein further supports its involvement as a CI modification factor. Taken together, these findings indicate that wPanCI and wPanMK have different relationships with their hosts in terms of their protective and CI phenotypes. It is therefore likely that different factors influence the prevalence and dynamics of these coinfections in natural Drosophila pandora hosts.IMPORTANCEWolbachia strains are common endosymbionts in insects, with multiple strains often coexisting in the same species. The coexistence of multiple strains is poorly understood but may rely on Wolbachia organisms having diverse phenotypic effects on their hosts. As Wolbachia is increasingly being developed as a tool to control disease transmission and suppress pest populations, it is important to understand the ways in which multiple Wolbachia strains persist in natural populations and how these might then be manipulated. We have therefore investigated viral protection and the molecular basis of cytoplasmic incompatibility in two coexisting Wolbachia strains with contrasting effects on host reproduction.}, }
@article {pmid30545384, year = {2018}, author = {Baldini, F and Rougé, J and Kreppel, K and Mkandawile, G and Mapua, SA and Sikulu-Lord, M and Ferguson, HM and Govella, N and Okumu, FO}, title = {First report of natural Wolbachia infection in the malaria mosquito Anopheles arabiensis in Tanzania.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {635}, pmid = {30545384}, issn = {1756-3305}, support = {//Wellcome Trust/United Kingdom ; WT102350/Z/13//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Anopheles/classification/*microbiology ; Cluster Analysis ; DNA, Bacterial/genetics ; Female ; Genetic Variation ; Malaria/*transmission ; Mosquito Vectors/classification/*microbiology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Tanzania ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {BACKGROUND: Natural infections of the endosymbiont bacteria Wolbachia have recently been discovered in populations of the malaria mosquito Anopheles gambiae (s.l.) in Burkina Faso and Mali, West Africa. This Anopheles specific strain wAnga limits the malaria parasite Plasmodium falciparum infections in the mosquito, thus it offers novel opportunities for malaria control.<br><br>RESULTS: We investigated Wolbachia presence in Anopheles arabiensis and Anopheles funestus, which are the two main malaria vectors in the Kilombero Valley, a malaria endemic region in south-eastern Tanzania. We found 3.1% (n = 65) and 7.5% (n = 147) wAnga infection prevalence in An. arabiensis in mosquitoes collected in 2014 and 2016, respectively, while no infection was detected in An. funestus (n = 41). Phylogenetic analysis suggests that at least two distinct strains of wAnga were detected, both belonging to Wolbachia supergroup A and B.<br><br>CONCLUSIONS: To our knowledge, this is the first confirmation of natural Wolbachia in malaria vectors in Tanzania, which opens novel questions on the ecological and genetic basis of its persistence and pathogen transmission in the vector hosts. Understanding the basis of interactions between Wolbachia, Anopheles mosquitoes and malaria parasites is crucial for investigation of its potential application as a biocontrol strategy to reduce malaria transmission, and assessment of how natural wAnga infections influence pathogen transmission in different ecological settings.}, }
@article {pmid30545379, year = {2018}, author = {Song, S and Chen, C and Yang, M and Zhao, S and Wang, B and Hornok, S and Makhatov, B and Rizabek, K and Wang, Y}, title = {Diversity of Rickettsia species in border regions of northwestern China.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {634}, pmid = {30545379}, issn = {1756-3305}, mesh = {Animals ; Biodiversity ; China ; DNA, Bacterial/genetics ; Disease Vectors/classification ; Genes, Bacterial/genetics ; *Genetic Variation ; Geography ; Ixodidae/classification/*microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/*genetics/isolation &amp; purification ; Rickettsia Infections/*microbiology ; Siphonaptera/classification/*microbiology ; }, abstract = {BACKGROUND: Rickettsia species belonging to the spotted fever group (SFG) cause infections in humans, domestic animals and wildlife. At least ten SFG Rickettsia species are known to occur in China. However, the distribution of rickettsiae in ticks and fleas in the border region of northwestern China have not been systematically studied to date.<br><br>RESULTS: A total of 982 ticks (Rhipicephalus turanicus, Dermacentor marginatus, D. nuttalli and Haemaphysalis punctata) and 5052 fleas (18 flea species from 14 species of wild mammals) were collected in ten and five counties, respectively, of Xinjiang Uygur Autonomous Region (northwestern China). Tick and flea species were identified according to morphological and molecular characteristics. Seven sets of primers for amplifying the 17-kDa antigen gene (17-kDa), citrate synthase gene (gltA), 16S rRNA gene (rrs), outer membrane protein A and B genes (ompA, ompB), surface cell antigen 1 gene (sca1) and PS120-protein encoding gene (gene D) were used to identify the species of rickettsiae. Nine Rickettsia species have been detected, seven of them in ticks: R. aeschlimannii, R. conorii, R. raoultii, Rickettsia sibirica, R. slovaca, R. massiliae and "Candidatus R. barbariae". In addition, R. bellii and two genotypes of a rickettsia endosymbiont (phylogenetically in an ancestral position to R. bellii) have been detected from flea pools.<br><br>CONCLUSIONS: This study provides molecular evidence for the occurrence of several SFG rickettsiae in Rhipicephalus turanicus, Dermacentor nuttalli and D. marginatus. Furthermore, R. bellii and two ancestral rickettsia endosymbionts are present in fleas infesting wild rodents in the border regions of northwestern China. These data extend our knowledge on the diversity of rickettsiae in Central Asia.}, }
@article {pmid30540238, year = {2019}, author = {Altamia, MA and Shipway, JR and Concepcion, GP and Haygood, MG and Distel, DL}, title = {Thiosocius teredinicola gen. nov., sp. nov., a sulfur-oxidizing chemolithoautotrophic endosymbiont cultivated from the gills of the giant shipworm, Kuphus polythalamius.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {69}, number = {3}, pages = {638-644}, pmid = {30540238}, issn = {1466-5034}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacterial Typing Techniques ; Base Composition ; Bivalvia/*microbiology ; Chemoautotrophic Growth ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Gammaproteobacteria/*classification/isolation &amp; purification ; Geologic Sediments/microbiology ; Gills/*microbiology ; Oxidation-Reduction ; Philippines ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sulfur/metabolism ; Thiosulfates ; }, abstract = {A chemolithoautotrophic sulfur-oxidizing, diazotrophic, facultatively heterotrophic, endosymbiotic bacterium, designated as strain 2141T, was isolated from the gills of the giant shipworm Kuphus polythalamius (Teredinidae: Bivalvia). Based on its 16S rRNA sequence, the endosymbiont falls within a clade that includes the as-yet-uncultivated thioautotrophic symbionts of a marine ciliate and hydrothermal vent gastropods, uncultivated marine sediment bacteria, and a free-living sulfur-oxidizing bacterium ODIII6, all of which belong to the Gammaproteobacteria. The endosymbiont is Gram-negative, rod-shaped and has a single polar flagellum when grown in culture. This bacterium can be grown chemolithoautotrophically on a chemically defined medium supplemented with either hydrogen sulfide, thiosulfate, tetrathionate or elemental sulfur. The closed-circular genome has a DNA G+C content of 60.1 mol% and is 4.79 Mbp in size with a large nitrogenase cluster spanning nearly 40 kbp. The diazotrophic capability was confirmed by growing the strain on chemolithoautotrophic thiosulfate-based medium without a combined source of fixed nitrogen. The bacterium is also capable of heterotrophic growth on organic acids such as acetate and propionate. The pH, temperature and salinity optima for chemolithoautotrophic growth on thiosulfate were found to be 8.5, 34 °C and 0.2 M NaCl, respectively. To our knowledge, this is the first report of pure culture of a thioautotrophic animal symbiont. The type strain of Thiosocius teredinicola is PMS-2141T.STBD.0c.01a[T] (=DSM 108030[T]).}, }
@article {pmid30483601, year = {2018}, author = {Jeffries, CL and Lawrence, GG and Golovko, G and Kristan, M and Orsborne, J and Spence, K and Hurn, E and Bandibabone, J and Tantely, LM and Raharimalala, FN and Keita, K and Camara, D and Barry, Y and Wat'senga, F and Manzambi, EZ and Afrane, YA and Mohammed, AR and Abeku, TA and Hedge, S and Khanipov, K and Pimenova, M and Fofanov, Y and Boyer, S and Irish, SR and Hughes, GL and Walker, T}, title = {Novel Wolbachia strains in Anopheles malaria vectors from Sub-Saharan Africa.}, journal = {Wellcome open research}, volume = {3}, number = {}, pages = {113}, pmid = {30483601}, issn = {2398-502X}, support = {U01CK000512/ACL/ACL HHS/United States ; R21 AI124452/AI/NIAID NIH HHS/United States ; R21 AI138074/AI/NIAID NIH HHS/United States ; R21 AI129507/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; R01 AI123074/AI/NIAID NIH HHS/United States ; }, abstract = {Background: Wolbachia, a common insect endosymbiotic bacterium that can influence pathogen transmission and manipulate host reproduction, has historically been considered absent from the Anopheles (An.) genera, but has recently been found in An. gambiae s.l. populations in West Africa. As there are numerous Anopheles species that have the capacity to transmit malaria, we analysed a range of species across five malaria endemic countries to determine Wolbachia prevalence rates, characterise novel Wolbachia strains and determine any correlation between the presence of Plasmodium, Wolbachia and the competing bacterium Asaia. Methods: Anopheles adult mosquitoes were collected from five malaria-endemic countries: Guinea, Democratic Republic of the Congo (DRC), Ghana, Uganda and Madagascar, between 2013 and 2017. Molecular analysis was undertaken using quantitative PCR, Sanger sequencing, Wolbachia multilocus sequence typing (MLST) and high-throughput amplicon sequencing of the bacterial 16S rRNA gene. Results: Novel Wolbachia strains were discovered in five species: An. coluzzii, An. gambiae s.s., An. arabiensis, An. moucheti and An. species A, increasing the number of Anopheles species known to be naturally infected. Variable prevalence rates in different locations were observed and novel strains were phylogenetically diverse, clustering with Wolbachia supergroup B strains. We also provide evidence for resident strain variants within An. species A. Wolbachia is the dominant member of the microbiome in An. moucheti and An. species A but present at lower densities in An. coluzzii. Interestingly, no evidence of Wolbachia/Asaia co-infections was seen and Asaia infection densities were shown to be variable and location dependent. Conclusions: The important discovery of novel Wolbachia strains in Anopheles provides greater insight into the prevalence of resident Wolbachia strains in diverse malaria vectors. Novel Wolbachia strains (particularly high-density strains) are ideal candidate strains for transinfection to create stable infections in other Anopheles mosquito species, which could be used for population replacement or suppression control strategies.}, }
@article {pmid30536677, year = {2019}, author = {Crowell, RM and Nienow, JA and Cahoon, AB}, title = {The complete chloroplast and mitochondrial genomes of the diatom Nitzschia palea (Bacillariophyceae) demonstrate high sequence similarity to the endosymbiont organelles of the dinotom Durinskia baltica.}, journal = {Journal of phycology}, volume = {55}, number = {2}, pages = {352-364}, doi = {10.1111/jpy.12824}, pmid = {30536677}, issn = {1529-8817}, mesh = {Chloroplasts ; *Diatoms ; *Dinoflagellida ; *Genome, Chloroplast ; *Genome, Mitochondrial ; Phylogeny ; Sequence Analysis, DNA ; }, abstract = {Nitzschia palea is a common freshwater diatom used as a bioindicator because of its tolerance of polluted waterways. There is also evidence it may be the tertiary endosymbiont within the "dinotom" dinoflagellate Durinskia baltica. A putative strain of N. palea was collected from a pond on the University of Virginia's College at Wise campus and cultured. For initial identification, three markers were sequenced-nuclear 18S rDNA, the chloroplast 23S rDNA, and rbcL. Morphological characteristics were determined using light and scanning electron microscopy; based on these observations the cells were identified as N. palea and named strain "Wise." DNA from N. palea was deep sequenced and the chloroplast and mitochondrial genomes assembled. Single gene phylogenies grouped N. palea-Wise within a clearly defined N. palea clade and showed it was most closely related to the strain "SpainA3." The chloroplast genome of N. palea is 119,447 bp with a quadripartite structure, 135 protein-coding, 28 tRNA, and 3 rRNA genes. The mitochondrial genome is 37,754 bp with a single repeat region as found in other diatom chondriomes, 37 protein-coding, 23 tRNA, and 2 rRNA genes. The chloroplast genomes of N. palea and D. baltica have identical gene content, synteny, and a 92.7% pair-wise sequence similarity with most differences occurring in intergenic regions. The N. palea mitochondrial genome and D. baltica's endosymbiont mitochondrial genome also have identical gene content and order with a sequence similarity of 90.7%. Genome-based phylogenies demonstrated that D. baltica is more similar to N. palea than any other diatom sequence currently available. These data provide the genome sequences of two organelles for a widespread diatom and show they are very similar to those of Durinskia baltica's endosymbiont.}, }
@article {pmid30535231, year = {2019}, author = {Qi, LD and Sun, JT and Hong, XY and Li, YX}, title = {Diversity and Phylogenetic Analyses Reveal Horizontal Transmission of Endosymbionts Between Whiteflies and Their Parasitoids.}, journal = {Journal of economic entomology}, volume = {112}, number = {2}, pages = {894-905}, doi = {10.1093/jee/toy367}, pmid = {30535231}, issn = {1938-291X}, mesh = {Animals ; China ; *Hemiptera ; Phylogeny ; Symbiosis ; *Wolbachia ; }, abstract = {Endosymbionts are widely distributed among insects via intraspecific vertical transmission and interspecific horizontal transmission. Parasitoids have attracted considerable interest due to their possible role in the horizontal transmission of endosymbionts. Horizontal transmission of endosymbionts between whiteflies via parasitoids has been revealed in the laboratory. However, whether this occurs under field conditions remains unknown. Here, the diversity and phylogenetic relationships of endosymbionts in 1,350 whiteflies and 36 parasitoids that emerged from whitefly nymphs collected from three locations in Jiangsu Province of China were investigated. Only Rickettsia and Wolbachia were identified in both whiteflies and parasitoids, with an overall infection frequency of 22.67% in whiteflies and 16.67% in parasitoids for Wolbachia and of 12.15% in whiteflies and 25% in parasitoids for Rickettsia. Despite the distant relationship between whiteflies and their parasitoids, phylogenetic analyses revealed that the Rickettsia and Wolbachia individuals collected from the two types of organisms were grouped together. Furthermore, shared haplotypes were also identified, which was consistent with the horizontal transmission of endosymbionts between parasitoids and whiteflies. In addition, a parasitoid resistance-related symbiont, Hamiltonella, was detected in whiteflies at a 100% infection frequency, probably accounting for the relatively low parasitism of the whiteflies in the field. The factors affecting the infection frequency of the four secondary endosymbionts in whiteflies were also examined.}, }
@article {pmid30533936, year = {2018}, author = {Estes, AM and Hearn, DJ and Nadendla, S and Pierson, EA and Dunning Hotopp, JC}, title = {Draft Genome Sequence of Enterobacter sp. Strain OLF, a Colonizer of Olive Flies.}, journal = {Microbiology resource announcements}, volume = {7}, number = {9}, pages = {}, pmid = {30533936}, issn = {2576-098X}, abstract = {Enterobacter sp. strain OLF colonizes laboratory-reared and wild individuals of the olive fruit fly Bactrocera oleae. The 5.07-kbp genome sequence of Enterobacter sp. strain OLF encodes metabolic pathways that allow the bacterium to partially supplement the diet of the olive fly when its dominant endosymbiont, Erwinia dacicola, is absent.}, }
@article {pmid30533772, year = {2018}, author = {Chung, M and Teigen, L and Libro, S and Bromley, RE and Kumar, N and Sadzewicz, L and Tallon, LJ and Foster, JM and Michalski, ML and Dunning Hotopp, JC}, title = {Multispecies Transcriptomics Data Set of Brugia malayi, Its Wolbachia Endosymbiont wBm, and Aedes aegypti across the B. malayi Life Cycle.}, journal = {Microbiology resource announcements}, volume = {7}, number = {18}, pages = {}, pmid = {30533772}, issn = {2576-098X}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, abstract = {Here, we present a comprehensive transcriptomics data set of Brugia malayi, its Wolbachia endosymbiont wBm, and its vector host. This study samples from 16 stages across the entire B. malayi life cycle, including stage 1 through 4 larvae, adult males and females, embryos, immature microfilariae, and mature microfilariae.}, }
@article {pmid30533624, year = {2018}, author = {Estes, AM and Hearn, DJ and Nadendla, S and Pierson, EA and Dunning Hotopp, JC}, title = {Draft Genome Sequence of Erwinia dacicola, a Dominant Endosymbiont of Olive Flies.}, journal = {Microbiology resource announcements}, volume = {7}, number = {10}, pages = {}, pmid = {30533624}, issn = {2576-098X}, abstract = {Erwinia dacicola is a dominant endosymbiont of the pestiferous olive fly. Its genome is similar in size and GC content to those of free-living Erwinia species, including the plant pathogen Erwinia amylovora. The E. dacicola genome encodes the metabolic capability to supplement and detoxify the olive fly's diet in larval and adult stages.}, }
@article {pmid30519408, year = {2018}, author = {Burmester, EM and Breef-Pilz, A and Lawrence, NF and Kaufman, L and Finnerty, JR and Rotjan, RD}, title = {The impact of autotrophic versus heterotrophic nutritional pathways on colony health and wound recovery in corals.}, journal = {Ecology and evolution}, volume = {8}, number = {22}, pages = {10805-10816}, pmid = {30519408}, issn = {2045-7758}, abstract = {For animals that harbor photosynthetic symbionts within their tissues, such as corals, the different relative contributions of autotrophy versus heterotrophy to organismal energetic requirements have direct impacts on fitness. This is especially true for facultatively symbiotic corals, where the balance between host-caught and symbiont-produced energy can be altered substantially to meet the variable demands of a shifting environment. In this study, we utilized a temperate coral-algal system (the northern star coral, Astrangia poculata, and its photosynthetic endosymbiont, Symbiodinium psygmophilum) to explore the impacts of nutritional sourcing on the host's health and ability to regenerate experimentally excised polyps. For fed and starved colonies, wound healing and total colony tissue cover were differentially impacted by heterotrophy versus autotrophy. There was an additive impact of positive nutritional and symbiotic states on a coral's ability to initiate healing, but a greater influence of symbiont state on the recovery of lost tissue at the lesion site and complete polyp regeneration. On the other hand, regardless of symbiont state, fed corals maintained a higher overall colony tissue cover, which also enabled more active host behavior (polyp extension) and endosymbiont behavior (photosynthetic ability of Symbiondinium). Overall, we determined that the impact of nutritional state and symbiotic state varied between biological functions, suggesting a diversity in energetic sourcing for each of these processes.}, }
@article {pmid30518817, year = {2019}, author = {Lim, SJ and Davis, BG and Gill, DE and Walton, J and Nachman, E and Engel, AS and Anderson, LC and Campbell, BJ}, title = {Taxonomic and functional heterogeneity of the gill microbiome in a symbiotic coastal mangrove lucinid species.}, journal = {The ISME journal}, volume = {13}, number = {4}, pages = {902-920}, pmid = {30518817}, issn = {1751-7370}, mesh = {Animals ; Bacteria/*classification/genetics ; Bivalvia/*microbiology ; Gills/microbiology ; Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sulfides/metabolism ; Symbiosis ; Wetlands ; }, abstract = {Lucinidae clams harbor gammaproteobacterial thioautotrophic gill endosymbionts that are environmentally acquired. Thioautotrophic lucinid symbionts are related to metabolically similar symbionts associated with diverse marine host taxa and fall into three distinct phylogenetic clades. Most studies on the lucinid-bacteria chemosymbiosis have been done with seagrass-dwelling hosts, whose symbionts belong to the largest phylogenetic clade. In this study, we examined the taxonomy and functional repertoire of bacterial endosymbionts at an unprecedented resolution from Phacoides pectinatus retrieved from mangrove-lined coastal sediments, which are underrepresented in chemosymbiosis studies. The P. pectinatus thioautotrophic endosymbiont expressed metabolic gene variants for thioautotrophy, respiration, and nitrogen assimilation distinct from previously characterized lucinid thioautotrophic symbionts and other marine symbionts. At least two other bacterial species with different metabolisms were also consistently identified in the P. pectinatus gill microbiome, including a Kistimonas-like species and a Spirochaeta-like species. Bacterial transcripts involved in adhesion, growth, and virulence and mixotrophy were highly expressed, as were host-related hemoglobin and lysozyme transcripts indicative of sulfide/oxygen/CO2 transport and bactericidal activity. This study suggests the potential roles of P. pectinatus and its gill microbiome species in mangrove sediment biogeochemistry and offers insights into host and microbe metabolisms in the habitat.}, }
@article {pmid30506836, year = {2019}, author = {Hartmann, AC and Marhaver, KL and Klueter, A and Lovci, MT and Closek, CJ and Diaz, E and Chamberland, VF and Archer, FI and Deheyn, DD and Vermeij, MJA and Medina, M}, title = {Acquisition of obligate mutualist symbionts during the larval stage is not beneficial for a coral host.}, journal = {Molecular ecology}, volume = {28}, number = {1}, pages = {141-155}, doi = {10.1111/mec.14967}, pmid = {30506836}, issn = {1365-294X}, support = {//PADI Foundation/International ; //CARMABI Foundation/International ; Graduate Office//Scripps Institution of Oceanography Graduate Office/International ; GK-12 Fellowship//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; Graduate Research Fellowship//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; IOS-1146880//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; OCE-0926822//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; OCE-1442206//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; OCE-1642311//National Science Foundation (NSF) GK-12 Fellowship, NSF Graduate Research Fellowship/International ; }, mesh = {Animals ; Anthozoa/genetics/*physiology ; *Biological Evolution ; Caribbean Region ; Coral Reefs ; Dinoflagellida/genetics/growth &amp; development ; *Ecology ; Larva/genetics ; Photosynthesis/genetics ; Symbiosis/*genetics ; }, abstract = {Theory suggests that the direct transmission of beneficial endosymbionts (mutualists) from parents to offspring (vertical transmission) in animal hosts is advantageous and evolutionarily stable, yet many host species instead acquire their symbionts from the environment (horizontal acquisition). An outstanding question in marine biology is why some scleractinian corals do not provision their eggs and larvae with the endosymbiotic dinoflagellates that are necessary for a juvenile's ultimate survival. We tested whether the acquisition of photosynthetic endosymbionts (family Symbiodiniaceae) during the planktonic larval stage was advantageous, as is widely assumed, in the ecologically important and threatened Caribbean reef-building coral Orbicella faveolata. Following larval acquisition, similar changes occurred in host energetic lipid use and gene expression regardless of whether their symbionts were photosynthesizing, suggesting the symbionts did not provide the energetic benefit characteristic of the mutualism in adults. Larvae that acquired photosymbionts isolated from conspecific adults on their natal reef exhibited a reduction in swimming, which may interfere with their ability to find suitable settlement substrate, and also a decrease in survival. Larvae exposed to two cultured algal species did not exhibit differences in survival, but decreased their swimming activity in response to one species. We conclude that acquiring photosymbionts during the larval stage confers no advantages and can in fact be disadvantageous to this coral host. The timing of symbiont acquisition appears to be a critical component of a host's life history strategy and overall reproductive fitness, and this timing itself appears to be under selective pressure.}, }
@article {pmid30503908, year = {2019}, author = {McLean, BJ and Dainty, KR and Flores, HA and O'Neill, SL}, title = {Differential suppression of persistent insect specific viruses in trans-infected wMel and wMelPop-CLA Aedes-derived mosquito lines.}, journal = {Virology}, volume = {527}, number = {}, pages = {141-145}, pmid = {30503908}, issn = {1096-0341}, support = {/WT_/Wellcome Trust/United Kingdom ; 102591/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/*microbiology/*virology ; Animals ; Cell Line ; Coinfection ; Flavivirus/*physiology ; Microbial Interactions ; Mosquito Vectors/microbiology/virology ; Orthobunyavirus/*physiology ; RNA, Viral/genetics/metabolism ; Species Specificity ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {Wolbachia suppresses the replication of +ssRNA viruses such as dengue and Zika viruses in Aedes aegypti mosquitoes. However, the range of viruses affected by this endosymbiont is yet to be explored. Recently, novel insect-specific viruses (ISVs) have been described from numerous mosquito species and mosquito-derived cell lines. Cell-fusing agent virus (Flaviviridae) and Phasi Charoen-like virus (Bunyaviridae) persistently infect the Ae. aegypti cell line Aag2 which has been used for experimental studies with both the wMel and wMelPop-CLA strains. Wolbachia was found to restrict the replication of CFAV but not the PCLV infection in these lines. Furthermore, an additional Ae. albopictus cell line (RML-12) which contained either wMel or wMelPop-CLA was assessed. While no infectious +ssRNA or dsRNA viruses were detected, a PCLV infection was identified. These observations provide additional evidence to support that insect-specific, +ssRNA viruses can be suppressed in cell culture by Wolbachia but -ssRNA viruses may not.}, }
@article {pmid30498482, year = {2018}, author = {Khare, E and Mishra, J and Arora, NK}, title = {Multifaceted Interactions Between Endophytes and Plant: Developments and Prospects.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {2732}, pmid = {30498482}, issn = {1664-302X}, abstract = {Microbial endophytes are present in all known plant species. The ability to enter and thrive in the plant tissues makes endophytes unique, showing multidimensional interactions within the host plant. Several vital activities of the host plant are known to be influenced by the presence of endophytes. They can promote plant growth, elicit defense response against pathogen attack, and can act as remediators of abiotic stresses. To date, most of the research has been done assuming that the interaction of endophytes with the host plant is similar to the plant growth-promoting (PGP) microbes present in the rhizosphere. However, a new appreciation of the difference of the rhizosphere environment from that of internal plant tissues is gaining attention. It would be interesting to explore the impact of endosymbionts on the host's gene expression, metabolism, and other physiological aspects essential in conferring resistance against biotic and abiotic stresses. A more intriguing and inexplicable issue with many endophytes that has to be critically evaluated is their ability to produce host metabolites, which can be harnessed on a large scale for potential use in diverse areas. In this review, we discuss the concept of endophytism, looking into the latest insights related to the multifarious interactions beneficial for the host plant and exploring the importance of these associations in agriculture and the environment and in other vital aspects such as human health.}, }
@article {pmid30496431, year = {2019}, author = {Sakamoto, H and Suzuki, R and Nishizawa, N and Matsuda, T and Gotoh, T}, title = {Effects of Wolbachia/Cardinium Infection on the Mitochondrial Phylogeny of Oligonychus castaneae (Acari: Tetranychidae).}, journal = {Journal of economic entomology}, volume = {112}, number = {2}, pages = {883-893}, doi = {10.1093/jee/toy354}, pmid = {30496431}, issn = {1938-291X}, mesh = {Animals ; Bacteroidetes ; DNA, Mitochondrial ; Japan ; Male ; Phylogeny ; Symbiosis ; *Tetranychidae ; *Wolbachia ; }, abstract = {A wide range of invertebrates harbor intracellular endosymbiotic bacteria. Within these endosymbionts, Wolbachia and Cardinium, have been attracting particular attention because these bacteria frequently affect the genetic structure and genetic diversity of their hosts. They cause various reproductive alterations such as cytoplasmic incompatibility, parthenogenesis induction, male-killing, and feminization. Through these alterations, they also affect the maternally inherited organelles of their hosts. Mitochondrial DNA (mtDNA) can be used for molecular phylogenetic analysis of invertebrates. However, in Wolbachia- or Cardinium-infected invertebrates, phylogenetic trees based on mtDNA are often inconsistent with those based on nuclear DNA. In the present study, we determined the Wolbachia/Cardinium infection status of 45 populations of the mite, Oligonychus castaneae Ehara &amp; Gotoh (Acari: Tetranychidae), collected throughout Japan. Then, we compared phylogenetic trees of O. castaneae based on both the cytochrome c oxidase subunit I (COI) gene of mtDNA and the 28S rRNA gene of nuclear DNA to clarify the effects of Wolbachia and/or Cardinium infection. We found 106 Wolbachia-infected individuals and 250 Cardinium-infected individuals in a total of 450 individuals, indicating an infection rate of 79%. No double-infected individuals were observed. In the 28S tree, almost all populations formed a single group. In the COI tree, O. castaneae formed four separate groups that more closely followed Wolbachia/Cardinium infection than geographic distribution. These results strongly suggest that the endosymbionts affected mitochondrial variation of O. castaneae.}, }
@article {pmid30484903, year = {2019}, author = {Grover, S and Jindal, V and Banta, G and Taning, CNT and Smagghe, G and Christiaens, O}, title = {Potential of RNA interference in the study and management of the whitefly, Bemisia tabaci.}, journal = {Archives of insect biochemistry and physiology}, volume = {100}, number = {2}, pages = {e21522}, doi = {10.1002/arch.21522}, pmid = {30484903}, issn = {1520-6327}, mesh = {Animals ; Hemiptera/*genetics/physiology ; Insect Control ; *RNA Interference ; }, abstract = {Whiteflies cause considerable losses to crops, directly by feeding, and indirectly by transmission of viruses. The current control methods consist of a combination of different control tactics, mainly still relying on unsafe and non-ecofriendly chemical control. RNA interference (RNAi) is a post-transcriptional gene-silencing strategy in which double-stranded RNA (dsRNA), corresponding specifically to a target gene, is introduced in a target organism. Research on RNAi in the previous decade has shown its success as a potential insect control strategy, which can be highly species-specific and environment friendly. In whiteflies, the success of dsRNA delivery through the oral route opened possibilities for its management through plant-mediated RNAi. To date, several genes have been targeted in whiteflies through RNAi and these assays demonstrated its potential to manage whiteflies at lab level. However, further research and investments are needed to move toward an application at field level. In this review, for the first time, we collected the literature on genes targeted for silencing via RNAi in whiteflies and discuss the potential of RNAi in whitefly pest control. We also discuss likely delivery methods, including transgenic in planta delivery and symbiont-mediated delivery, and its potential for studying and interfering with insecticide resistance mechanisms and virus transmission by whiteflies.}, }
@article {pmid30482201, year = {2018}, author = {Cenci, U and Sibbald, SJ and Curtis, BA and Kamikawa, R and Eme, L and Moog, D and Henrissat, B and Maréchal, E and Chabi, M and Djemiel, C and Roger, AJ and Kim, E and Archibald, JM}, title = {Nuclear genome sequence of the plastid-lacking cryptomonad Goniomonas avonlea provides insights into the evolution of secondary plastids.}, journal = {BMC biology}, volume = {16}, number = {1}, pages = {137}, pmid = {30482201}, issn = {1741-7007}, mesh = {Algal Proteins/analysis ; Cell Nucleus/genetics ; Cryptophyta/cytology/*genetics ; *Evolution, Molecular ; *Genome ; Phylogeny ; Plastids/*genetics ; Tryptophan-tRNA Ligase/analysis ; }, abstract = {BACKGROUND: The evolution of photosynthesis has been a major driver in eukaryotic diversification. Eukaryotes have acquired plastids (chloroplasts) either directly via the engulfment and integration of a photosynthetic cyanobacterium (primary endosymbiosis) or indirectly by engulfing a photosynthetic eukaryote (secondary or tertiary endosymbiosis). The timing and frequency of secondary endosymbiosis during eukaryotic evolution is currently unclear but may be resolved in part by studying cryptomonads, a group of single-celled eukaryotes comprised of both photosynthetic and non-photosynthetic species. While cryptomonads such as Guillardia theta harbor a red algal-derived plastid of secondary endosymbiotic origin, members of the sister group Goniomonadea lack plastids. Here, we present the genome of Goniomonas avonlea-the first for any goniomonad-to address whether Goniomonadea are ancestrally non-photosynthetic or whether they lost a plastid secondarily.<br><br>RESULTS: We sequenced the nuclear and mitochondrial genomes of Goniomonas avonlea and carried out a comparative analysis of Go. avonlea, Gu. theta, and other cryptomonads. The Go. avonlea genome assembly is ~&#x2009;92 Mbp in size, with 33,470 predicted protein-coding genes. Interestingly, some metabolic pathways (e.g., fatty acid biosynthesis) predicted to occur in the plastid and periplastidal compartment of Gu. theta appear to operate in the cytoplasm of Go. avonlea, suggesting that metabolic redundancies were generated during the course of secondary plastid integration. Other cytosolic pathways found in Go. avonlea are not found in Gu. theta, suggesting secondary loss in Gu. theta and other plastid-bearing cryptomonads. Phylogenetic analyses revealed no evidence for algal endosymbiont-derived genes in the Go. avonlea genome. Phylogenomic analyses point to a specific relationship between Cryptista (to which cryptomonads belong) and Archaeplastida.<br><br>CONCLUSION: We found no convincing genomic or phylogenomic evidence that Go. avonlea evolved from a secondary red algal plastid-bearing ancestor, consistent with goniomonads being ancestrally non-photosynthetic eukaryotes. The Go. avonlea genome sheds light on the physiology of heterotrophic cryptomonads and serves as an important reference point for studying the metabolic "rewiring" that took place during secondary plastid integration in the ancestor of modern-day Cryptophyceae.}, }
@article {pmid30474731, year = {2019}, author = {Hosseinzadeh, S and Shams-Bakhsh, M and Mann, M and Fattah-Hosseini, S and Bagheri, A and Mehrabadi, M and Heck, M}, title = {Distribution and Variation of Bacterial Endosymbiont and "Candidatus Liberibacter asiaticus" Titer in the Huanglongbing Insect Vector, Diaphorina citri Kuwayama.}, journal = {Microbial ecology}, volume = {78}, number = {1}, pages = {206-222}, pmid = {30474731}, issn = {1432-184X}, mesh = {Animals ; Citrus/*microbiology/parasitology ; Endophytes/genetics/isolation &amp; purification/*physiology ; Female ; Hemiptera/*microbiology/physiology ; Insect Vectors/microbiology/physiology ; Male ; Plant Diseases/*microbiology ; Rhizobiaceae/genetics/isolation &amp; purification/*physiology ; *Symbiosis ; Wolbachia/genetics/isolation &amp; purification/physiology ; }, abstract = {The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is an economic insect pest in most citrus-growing regions and the vector of 'Candidatus Liberibacter asiaticus' (CLas), one of at least three known bacteria associated with Huanglongbing (HLB or citrus greening disease). D. citri harbors bacterial endosymbionts, including Wolbachia pipientis (strain Wolbachia wDi), 'Candidatus Carsonella ruddii,' and 'Candidatus Profftella armatura.' Many important functions of these bacteria can be inferred from their genome sequences, but their interactions with each other, CLas, and their D. citri host are poorly understood. In the present study, the titers of the endosymbionts in different tissues, in each sex, and in insects reared on healthy citrus (referred to as unexposed) and CLas-infected citrus (referred to as CLas-exposed) D. citri were investigated using real-time, quantitative PCR (qPCR) using two different quantitative approaches. Wolbachia and CLas were detected in all insect tissues. The titer of Wolbachia was higher in heads of CLas-exposed males as compared to unexposed males. In males and females, Wolbachia titer was highest in the Malpighian tubules. The highest titer of CLas was observed in the gut. Profftella and Carsonella titers were significantly reduced in the bacteriome of CLas-exposed males compared with that of unexposed males, but this effect was not observed in females. In ovaries of CLas-exposed females, the Profftella and Carsonella titers were increased as compared to non-exposed females. CLas appeared to influence the overall levels of the symbionts but did not drastically perturb the overall microbial community structure. In all the assessed tissues, CLas titer in males was significantly higher than that of females using absolute quantification. These data provide a better understanding of multi-trophic interactions regulating symbiont dynamics in the HLB pathosystem.}, }
@article {pmid30472481, year = {2019}, author = {Marangoni, LFB and Pinto, MMAN and Marques, JA and Bianchini, A}, title = {Copper exposure and seawater acidification interaction: Antagonistic effects on biomarkers in the zooxanthellate scleractinian coral Mussismilia harttii.}, journal = {Aquatic toxicology (Amsterdam, Netherlands)}, volume = {206}, number = {}, pages = {123-133}, doi = {10.1016/j.aquatox.2018.11.005}, pmid = {30472481}, issn = {1879-1514}, mesh = {Animals ; Anthozoa/*drug effects ; Biomarkers/*metabolism ; Chlorophyll A/analysis ; Copper/*toxicity ; Hydrogen-Ion Concentration ; Photosynthesis/drug effects ; Seawater/*chemistry ; Water Pollutants, Chemical/toxicity ; }, abstract = {Coral reefs are threatened by global and local impacts, such as ocean acidification (OA) and metal contamination. Toxicity of metals, such as copper (Cu), is expected to be enhanced with OA. However, the interaction between these environmental stressors is still poorly evaluated. In the present study, the interactive effects of seawater acidification and increasing Cu concentrations were evaluated in a zooxanthellate scleractinian coral (Mussismilia harttii), using biochemical biomarkers involved in the coral calcification process and the photosynthetic metabolism of endosymbionts. Corals were kept under control conditions (no seawater acidification and no Cu addition in seawater) or exposed to combined treatments of reduced seawater pH (8.1, 7.8, 7.5 and 7.2) and environmentally relevant concentrations of dissolved Cu (measured: 1.0, 1.6, 2.3 and 3.2 μg/L) in a mesocosm system. After 15- and 35-days exposure, corals were analyzed for photochemical efficiency (Fv/Fm), chlorophyll a content, Ca-ATPase and carbonic anhydrase (CA) activity. Results showed that 76% of the interactions between reduced seawater pH and increasing Cu concentrations were antagonistic. Only 24% of these interactions were additive or synergistic. In general, the combination of stressors had no significant deleterious effects in the photosynthetic metabolism of endosymbionts or Ca-ATPase activity. In fact, the lowest dissolved Cu concentration tested had a consistent positive effect on Ca-ATPase activity in corals facing any of the reduced seawater pH conditions tested. In turn, potentially deleterious effects on acid-base balance in M. harttii, associated with changes in CA activity, were intensified by the combination of stressors. Findings reported here indicate that Cu toxicity in future OA scenarios can be less severe than previously suggested in this coral holobiont.}, }
@article {pmid30470198, year = {2018}, author = {Scolari, F and Attardo, GM and Aksoy, E and Weiss, B and Savini, G and Takac, P and Abd-Alla, A and Parker, AG and Aksoy, S and Malacrida, AR}, title = {Symbiotic microbes affect the expression of male reproductive genes in Glossina m. morsitans.}, journal = {BMC microbiology}, volume = {18}, number = {Suppl 1}, pages = {169}, pmid = {30470198}, issn = {1471-2180}, support = {R21 AI109263/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Female ; Insect Control ; Male ; *Microbiota ; Reproduction/genetics ; Sex Factors ; *Symbiosis ; Testis ; Transcriptome ; Tsetse Flies/*genetics/*microbiology ; }, abstract = {BACKGROUND: Tsetse flies (Diptera, Glossinidae) display unique reproductive biology traits. Females reproduce through adenotrophic viviparity, nourishing the growing larva into their modified uterus until parturition. Males transfer their sperm and seminal fluid, produced by both testes and male accessory glands, in a spermatophore capsule transiently formed within the female reproductive tract upon mating. Both sexes are obligate blood feeders and have evolved tight relationships with endosymbionts, already shown to provide essential nutrients lacking in their diet. However, the partnership between tsetse and its symbionts has so far been investigated, at the molecular, genomic and metabolomics level, only in females, whereas the roles of microbiota in male reproduction are still unexplored.<br><br>RESULTS: Here we begin unravelling the impact of microbiota on Glossina m. morsitans (G. morsitans) male reproductive biology by generating transcriptomes from the reproductive tissues of males deprived of their endosymbionts (aposymbiotic) via maternal antibiotic treatment and dietary supplementation. We then compared the transcriptional profiles of genes expressed in the male reproductive tract of normal and these aposymbiotic flies. We showed that microbiota removal impacts several male reproductive genes by depressing the activity of genes in the male accessory glands (MAGs), including sequences encoding seminal fluid proteins, and increasing expression of genes in the testes. In the MAGs, in particular, the expression of genes related to mating, immunity and seminal fluid components' synthesis is reduced. In the testes, the absence of symbionts activates genes involved in the metabolic apparatus at the basis of male reproduction, including sperm production, motility and function.<br><br>CONCLUSIONS: Our findings mirrored the complementary roles male accessory glands and testes play in supporting male reproduction and open new avenues for disentangling the interplay between male insects and endosymbionts. From an applied perspective, unravelling the metabolic and functional relationships between tsetse symbionts and male reproductive physiology will provide fundamental information useful to understanding the biology underlying improved male reproductive success in tsetse. This information is of particular importance in the context of tsetse population control via Sterile Insect Technique (SIT) and its impact on trypanosomiasis transmission.}, }
@article {pmid30470188, year = {2018}, author = {Engl, T and Michalkova, V and Weiss, BL and Uzel, GD and Takac, P and Miller, WJ and Abd-Alla, AMM and Aksoy, S and Kaltenpoth, M}, title = {Effect of antibiotic treatment and gamma-irradiation on cuticular hydrocarbon profiles and mate choice in tsetse flies (Glossina m. morsitans).}, journal = {BMC microbiology}, volume = {18}, number = {Suppl 1}, pages = {145}, pmid = {30470188}, issn = {1471-2180}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; P 28255/FWF_/Austrian Science Fund FWF/Austria ; R01 AI051584/AI/NIAID NIH HHS/United States ; }, mesh = {Ampicillin/pharmacology ; Animals ; Anti-Bacterial Agents/*pharmacology ; Female ; Hydrocarbons/*analysis ; Insect Proteins/*chemistry/radiation effects ; Male ; Microbiota/*drug effects ; *Sexual Behavior, Animal/drug effects/radiation effects ; Symbiosis/drug effects ; Tetracycline/pharmacology ; Tsetse Flies/*physiology/radiation effects ; }, abstract = {BACKGROUND: Symbiotic microbes represent a driving force of evolutionary innovation by conferring novel ecological traits to their hosts. Many insects are associated with microbial symbionts that contribute to their host's nutrition, digestion, detoxification, reproduction, immune homeostasis, and defense. In addition, recent studies suggest a microbial involvement in chemical communication and mating behavior, which can ultimately impact reproductive isolation and, hence, speciation. Here we investigated whether a disruption of the microbiota through antibiotic treatment or irradiation affects cuticular hydrocarbon profiles, and possibly mate choice behavior in the tsetse fly, Glossina morsitans morsitans. Four independent experiments that differentially knock down the multiple bacterial symbionts of tsetse flies were conducted by subjecting tsetse flies to ampicillin, tetracycline, or gamma-irradiation and analyzing their cuticular hydrocarbon profiles in comparison to untreated controls by gas chromatography - mass spectrometry. In two of the antibiotic experiments, flies were mass-reared, while individual rearing was done for the third experiment to avoid possible chemical cross-contamination between individual flies.<br><br>RESULTS: All three antibiotic experiments yielded significant effects of antibiotic treatment (particularly tetracycline) on cuticular hydrocarbon profiles in both female and male G. m. morsitans, while irradiation itself had no effect on the CHC profiles. Importantly, tetracycline&#xa0;treatment reduced relative amounts of 15,19,23-trimethyl-heptatriacontane, a known compound of the female contact sex pheromone, in two of the three experiments, suggesting a possible implication of microbiota disturbance on mate choice decisions. Concordantly, both female and male flies preferred non-treated over tetracycline-treated flies in direct choice assays.<br><br>CONCLUSIONS: While we cannot exclude the possibility that antibiotic treatment had a directly detrimental effect on fly vigor as we are unable&#xa0;to recolonize antibiotic treated flies with individual symbiont taxa, our results are consistent with an effect of the microbiota, particularly the obligate nutritional endosymbiont Wigglesworthia, on CHC profiles and mate choice behavior. These findings highlight the importance of considering host-microbiota interactions when studying chemical communication and mate choice in insects.}, }
@article {pmid30470184, year = {2018}, author = {Channumsin, M and Ciosi, M and Masiga, D and Turner, CMR and Mable, BK}, title = {Sodalis glossinidius presence in wild tsetse is only associated with presence of trypanosomes in complex interactions with other tsetse-specific factors.}, journal = {BMC microbiology}, volume = {18}, number = {Suppl 1}, pages = {163}, pmid = {30470184}, issn = {1471-2180}, support = {//Wellcome Trust/United Kingdom ; 093692//Wellcome Trust/United Kingdom ; }, mesh = {Age Factors ; Animals ; Enterobacteriaceae/*physiology ; Environment ; Female ; Geography ; Kenya ; Male ; Sex Factors ; *Symbiosis ; Tsetse Flies/*microbiology/*parasitology ; }, abstract = {BACKGROUND: Susceptibility of tsetse flies (Glossina spp.) to trypanosomes of both humans and animals has been associated with the presence of the endosymbiont Sodalis glossinidius. However, intrinsic biological characteristics of the flies and environmental factors can influence the presence of both S. glossinidius and the parasites. It thus remains unclear whether it is the S. glossinidius or other attributes of the flies that explains the apparent association. The objective of this study was to test whether the presence of Trypanosoma vivax, T. congolense and T. brucei are related to the presence of S. glossinidius in tsetse flies when other factors are accounted for: geographic location, species of Glossina, sex or age of the host flies.<br><br>RESULTS: Flies (n&#x2009;=&#x2009;1090) were trapped from four sites in the Shimba Hills and Nguruman regions in Kenya. Sex and species of tsetse (G. austeni, G. brevipalpis, G. longipennis and G. pallidipes) were determined based on external morphological characters and age was estimated by a wing fray score method. The presence of trypanosomes and S. glossinidius was detected using PCR targeting the internal transcribed spacer region 1 and the haemolysin gene, respectively. Sequencing was used to confirm species identification. Generalised Linear Models (GLMs) and Multiple Correspondence Analysis (MCA) were applied to investigate multivariable associations. The overall prevalence of trypanosomes was 42.1%, but GLMs revealed complex patterns of associations: the presence of S. glossinidius was associated with trypanosome presence but only in interactions with other factors and only in some species of trypanosomes. The strongest association was found for T. congolense, and no association was found for T. vivax. The MCA also suggested only a weak association between the presence of trypanosomes and S. glossinidius. Trypanosome-positive status showed strong associations with sex and age while S. glossinidius-positive status showed a strong association with geographic location and species of fly.<br><br>CONCLUSIONS: We suggest that previous conclusions about the presence of endosymbionts increasing probability of trypanosome presence in tsetse flies may have been confounded by other factors, such as community composition of the tsetse flies and the specific trypanosomes found in different regions.}, }
@article {pmid30470178, year = {2018}, author = {Griffith, BC and Weiss, BL and Aksoy, E and Mireji, PO and Auma, JE and Wamwiri, FN and Echodu, R and Murilla, G and Aksoy, S}, title = {Analysis of the gut-specific microbiome from field-captured tsetse flies, and its potential relevance to host trypanosome vector competence.}, journal = {BMC microbiology}, volume = {18}, number = {Suppl 1}, pages = {146}, pmid = {30470178}, issn = {1471-2180}, support = {D43 TW007391/TW/FIC NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; U01 AI115648/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification ; *Gastrointestinal Microbiome ; Geography ; High-Throughput Nucleotide Sequencing ; Insect Vectors/*microbiology/parasitology ; Kenya ; Symbiosis ; Trypanosoma/*physiology ; Tsetse Flies/*microbiology/parasitology ; Uganda ; }, abstract = {BACKGROUND: The tsetse fly (Glossina sp.) midgut is colonized by maternally transmitted and environmentally acquired bacteria. Additionally, the midgut serves as a niche in which pathogenic African trypanosomes reside within infected flies. Tsetse's bacterial microbiota impacts many aspects of the fly's physiology. However, little is known about the structure of tsetse's midgut-associated bacterial communities as they relate to geographically distinct fly habitats in east Africa and their contributions to parasite infection outcomes. We utilized culture dependent and independent methods to characterize the taxonomic structure and density of bacterial communities that reside within the midgut of tsetse flies collected at geographically distinct locations in Kenya and Uganda.<br><br>RESULTS: Using culture dependent methods, we isolated 34 strains of bacteria from four different tsetse species (G. pallidipes, G. brevipalpis, G. fuscipes and G. fuscipleuris) captured at three distinct locations in Kenya. To increase the depth of this study, we deep sequenced midguts from individual uninfected and trypanosome infected G. pallidipes captured at two distinct locations in Kenya and one in Uganda. We found that tsetse's obligate endosymbiont, Wigglesworthia, was the most abundant bacterium present in the midgut of G. pallidipes, and the density of this bacterium remained largely consistent regardless of whether or not its tsetse host was infected with trypanosomes. These fly populations also housed the commensal symbiont Sodalis, which was found at significantly higher densities in trypanosome infected compared to uninfected flies. Finally, midguts of field-captured G. pallidipes were colonized with distinct, low density communities of environmentally acquired microbes that differed in taxonomic structure depending on parasite infection status and the geographic location from which the flies were collected.<br><br>CONCLUSIONS: The results of this study will enhance our understanding of the tripartite relationship between tsetse, its microbiota and trypanosome vector competence. This information may be useful for developing novel disease control strategies or enhancing the efficacy of those already in use.}, }
@article {pmid30470176, year = {2018}, author = {Zaidman-Rémy, A and Vigneron, A and Weiss, BL and Heddi, A}, title = {What can a weevil teach a fly, and reciprocally? Interaction of host immune systems with endosymbionts in Glossina and Sitophilus.}, journal = {BMC microbiology}, volume = {18}, number = {Suppl 1}, pages = {150}, pmid = {30470176}, issn = {1471-2180}, support = {R01 AI051584/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Biological Evolution ; Enterobacteriaceae/immunology ; Host Microbial Interactions/*immunology ; Pest Control ; Symbiosis/*immunology ; Tsetse Flies/immunology/*microbiology ; Weevils/immunology/*microbiology ; Wigglesworthia/immunology ; Wolbachia/immunology ; }, abstract = {The tsetse fly (Glossina genus) is the main vector of African trypanosomes, which are protozoan parasites that cause human and animal African trypanosomiases in Sub-Saharan Africa. In the frame of the IAEA/FAO program 'Enhancing Vector Refractoriness to Trypanosome Infection', in addition to the tsetse, the cereal weevil Sitophilus has been introduced as a comparative system with regards to immune interactions with endosymbionts. The cereal weevil is an agricultural pest that destroys a significant proportion of cereal stocks worldwide. Tsetse flies are associated with three symbiotic bacteria, the multifunctional obligate Wigglesworthia glossinidia, the facultative commensal Sodalis glossinidius and the parasitic Wolbachia. Cereal weevils house an obligatory nutritional symbiosis with the bacterium Sodalis pierantonius, and occasionally Wolbachia. Studying insect host-symbiont interactions is highly relevant both for understanding the evolution of symbiosis and for envisioning novel pest control strategies. In both insects, the long co-evolution between host and endosymbiont has led to a stringent integration of the host-bacteria partnership. These associations were facilitated by the development of specialized host traits, including symbiont-housing cells called bacteriocytes and specific immune features that enable both tolerance and control of the bacteria. In this review, we compare the tsetse and weevil model systems and compile the latest research findings regarding their biological and ecological similarities, how the immune system controls endosymbiont load and location, and how host-symbiont interactions impact developmental features including cuticle synthesis and immune system maturation. We focus mainly on the interactions between the obligate symbionts and their host's immune systems, a central theme in both model systems. Finally, we highlight how parallel studies on cereal weevils and tsetse flies led to mutual discoveries and stimulated research on each model, creating a pivotal example of scientific improvement through comparison between relatively distant models.}, }
@article {pmid30468769, year = {2019}, author = {Bi, J and Zheng, Y and Wang, RF and Ai, H and Haynes, PR and Brownlie, JC and Yu, XQ and Wang, YF}, title = {Wolbachia infection may improve learning and memory capacity of Drosophila by altering host gene expression through microRNA.}, journal = {Insect biochemistry and molecular biology}, volume = {106}, number = {}, pages = {47-54}, doi = {10.1016/j.ibmb.2018.11.007}, pmid = {30468769}, issn = {1879-0240}, mesh = {Animals ; Drosophila melanogaster/microbiology/*physiology ; Drosophila simulans/microbiology/*physiology ; *Gene Expression Regulation ; Learning ; Memory ; MicroRNAs/*genetics/metabolism ; Wolbachia/*physiology ; }, abstract = {Wolbachia are endosymbiotic bacteria present in a wide range of invertebrates. Although their dramatic effects on host reproductive biology have been well studied, little is known about the effects of Wolbachia on the learning and memory capacity (LMC) of hosts, despite their distribution in the host nervous system, including brain. In this study, we found that Wolbachia infection significantly enhanced LMC in both Drosophila melanogaster and D. simulans. Expression of LMC-related genes was significantly increased in the head of D. melanogaster infected with the wMel strain, and among these genes, crebA was up-regulated the most. Knockdown of crebA in Wolbachia-infected flies significantly decreased LMC, while overexpression of crebA in Wolbachia-free flies significantly enhanced the LMC of flies. More importantly, a microRNA (miRNA), dme-miR-92b, was identified to be complementary to the 3'UTR of crebA. Wolbachia infection was correlated with reduced expression of dme-miR-92b in D. melanogaster, and dme-miR-92b negatively regulated crebA through binding to its 3'UTR region. Overexpression of dme-miR-92b in Wolbachia-infected flies by microinjection of agomirs caused a significant decrease in crebA expression and LMC, while inhibition of dme-miR-92b in Wolbachia-free flies by microinjection of antagomirs resulted in a significant increase in crebA expression and LMC. These results suggest that Wolbachia may improve LMC in Drosophila by altering host gene expression through a miRNA-target pathway. Our findings help better understand the host-endosymbiont interactions and, in particular, the impact of Wolbachia on cognitive processes in invertebrate hosts.}, }
@article {pmid30464337, year = {2018}, author = {Chen, YL and Chen, LJ and Chu, CC and Huang, PK and Wen, JR and Li, HM}, title = {TIC236 links the outer and inner membrane translocons of the chloroplast.}, journal = {Nature}, volume = {564}, number = {7734}, pages = {125-129}, doi = {10.1038/s41586-018-0713-y}, pmid = {30464337}, issn = {1476-4687}, mesh = {Arabidopsis/*cytology/metabolism ; Arabidopsis Proteins/genetics/*metabolism ; Bacterial Outer Membrane Proteins/metabolism ; Chloroplast Proteins/genetics/*metabolism ; Chloroplasts/genetics/*metabolism ; Escherichia coli Proteins/metabolism ; Evolution, Molecular ; Intracellular Membranes/*metabolism ; Membrane Proteins/genetics/*metabolism ; Membrane Transport Proteins/genetics/*metabolism ; Multiprotein Complexes/genetics/metabolism ; Mutation ; Peas/cytology ; Protein Binding ; Protein Precursors/metabolism ; Protein Transport ; }, abstract = {The two-membrane envelope is a defining feature of chloroplasts. Chloroplasts evolved from a Gram-negative cyanobacterial endosymbiont. During evolution, genes of the endosymbiont have been transferred to the host nuclear genome. Most chloroplast proteins are synthesized in the cytosol as higher-molecular-mass preproteins with an N-terminal transit peptide. Preproteins are transported into chloroplasts by the TOC and TIC (translocons at the outer- and inner-envelope membranes of chloroplasts, respectively) machineries[1,2], but how TOC and TIC are assembled together is unknown. Here we report the identification of the TIC component TIC236; TIC236 is an integral inner-membrane protein that projects a 230-kDa domain into the intermembrane space, which binds directly to the outer-membrane channel TOC75. The knockout mutation of TIC236 is embryonically lethal. In TIC236-knockdown mutants, a smaller amount of the inner-membrane channel TIC20 was associated with TOC75; the amount of TOC-TIC supercomplexes was also reduced. This resulted in a reduced import rate into the stroma, though outer-membrane protein insertion was unaffected. The size and the essential nature of TIC236 indicate that-unlike in mitochondria, in which the outer- and inner-membrane translocons exist as separate complexes and a supercomplex is only transiently assembled during preprotein translocation[3,4]-a long and stable protein bridge in the intermembrane space is required for protein translocation into chloroplasts. Furthermore, TIC236 and TOC75 are homologues of bacterial inner-membrane TamB[5] and outer-membrane BamA, respectively. Our evolutionary analyses show that, similar to TOC75, TIC236 is preserved only in plants and has co-evolved with TOC75 throughout the plant lineage. This suggests that the backbone of the chloroplast protein-import machinery evolved from the bacterial TamB-BamA protein-secretion system.}, }
@article {pmid30459726, year = {2018}, author = {Brown, AMV and Wasala, SK and Howe, DK and Peetz, AB and Zasada, IA and Denver, DR}, title = {Comparative Genomics of Wolbachia-Cardinium Dual Endosymbiosis in a Plant-Parasitic Nematode.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {2482}, pmid = {30459726}, issn = {1664-302X}, abstract = {Wolbachia and Cardinium are among the most important and widespread of all endosymbionts, occurring in nematodes and more than half of insect and arachnid species, sometimes as coinfections. These symbionts are of significant interest as potential biocontrol agents due to their abilities to cause major effects on host biology and reproduction through cytoplasmic incompatibility, sex ratio distortion, or obligate mutualism. The ecological and metabolic effects of coinfections are not well understood. This study examined a Wolbachia-Cardinium coinfection in the plant-parasitic nematode (PPN), Pratylenchus penetrans, producing the first detailed study of such a coinfection using fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and comparative genomic analysis. Results from FISH and single-nematode PCR showed 123/127 individuals in a focal population carried Cardinium (denoted strain cPpe), and 48% were coinfected with Wolbachia strain wPpe. Both endosymbionts showed dispersed tissue distribution with highest densities in the anterior intestinal walls and gonads. Phylogenomic analyses confirmed an early place of cPpe and long distance from a sister strain in another PPN, Heterodera glycines, supporting a long history of both Cardinium and Wolbachia in PPNs. The genome of cPpe was 1.36 Mbp with 35.8% GC content, 1,131 predicted genes, 41% having no known function, and missing biotin and lipoate synthetic capacity and a plasmid present in other strains, despite having a slightly larger genome compared to other sequenced Cardinium. The larger genome revealed expansions of gene families likely involved in host-cellular interactions. More than 2% of the genes of cPpe and wPpe were identified as candidate horizontally transferred genes, with some of these from eukaryotes, including nematodes. A model of the possible Wolbachia-Cardinium interaction is proposed with possible complementation in function for pathways such as methionine and fatty acid biosynthesis and biotin transport.}, }
@article {pmid30458311, year = {2019}, author = {Yu, J and Wang, M and Liu, B and Yue, X and Li, C}, title = {Gill symbionts of the cold-seep mussel Bathymodiolus platifrons: Composition, environmental dependency and immune control.}, journal = {Fish &amp; shellfish immunology}, volume = {86}, number = {}, pages = {246-252}, doi = {10.1016/j.fsi.2018.11.041}, pmid = {30458311}, issn = {1095-9947}, mesh = {Animals ; Bacteria/classification/metabolism ; Gene Expression ; Gills/metabolism/*microbiology ; Methane/metabolism ; Mytilidae/immunology/metabolism/*microbiology ; R-SNARE Proteins/genetics/metabolism ; RNA, Messenger ; RNA, Ribosomal, 16S ; Symbiosis/*physiology ; }, abstract = {Deep-sea Bathymodiolus mussels depend on the organic carbon supplied by symbionts inside their gills. In this study, optimized methods of quantitative real-time PCR and fluorescence in situ hybridization targeted to both mRNA and 16S rRNA were used to investigate the gill symbionts of the cold-seep mussel Bathymodiolus platifrons, including species composition, environmental dependency and immune control by the host. Our results showed that methanotrophs were the major symbiotic bacteria in the gills of B. platifrons, while thiotrophs were scarce. In the mussels freshly collected from the deep sea, methanotrophs were housed in bacteriocytes in a unique circular pattern, and a lysosome-related gene (VAMP) encoding a vesicle-associated membrane protein was expressed at a high level and presented exactly where the methanotrophs occurred. After the mussels were reared for three months in aquaria without methane supply, the abundance of methanotrophs decreased significantly and their circle-shaped distribution pattern disappeared; in addition, the expression of VAMP decreased significantly. These results suggest that the symbiosis between B. platifrons and methanotrophs is influenced by the environment and that the lysosomal system plays an important immune role in controlling the abundance of endosymbionts in host. This study provides a reliable method for investigating symbionts in deep-sea mussels and enriches the knowledge about symbionts in B. platifrons.}, }
@article {pmid30456532, year = {2019}, author = {Schneider, DI and Ehrman, L and Engl, T and Kaltenpoth, M and Hua-Van, A and Le Rouzic, A and Miller, WJ}, title = {Symbiont-Driven Male Mating Success in the Neotropical Drosophila paulistorum Superspecies.}, journal = {Behavior genetics}, volume = {49}, number = {1}, pages = {83-98}, pmid = {30456532}, issn = {1573-3297}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; P 28255/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Behavior, Animal ; Biological Evolution ; Drosophila/*microbiology ; Drosophila Proteins/metabolism ; Female ; Male ; Reproduction/*physiology ; Reproductive Isolation ; Sex Attractants/metabolism/physiology ; Sexual Behavior, Animal/physiology ; Species Specificity ; Symbiosis/*genetics ; Wolbachia/physiology ; }, abstract = {Microbial symbionts are ubiquitous associates of living organisms but their role in mediating reproductive isolation (RI) remains controversial. We addressed this knowledge gap by employing the Drosophila paulistorum-Wolbachia model system. Semispecies in the D. paulistorum species complex exhibit strong RI between each other and knockdown of obligate mutualistic Wolbachia bacteria in female D. paulistorum flies triggers loss of assortative mating behavior against males carrying incompatible Wolbachia strains. Here we set out to determine whether de novo RI can be introduced by Wolbachia-knockdown in D. paulistorum males. We show that Wolbachia-knockdown D. paulistorum males (i) are rejected as mates by wild type females, (ii) express altered sexual pheromone profiles, and (iii) are devoid of the endosymbiont in pheromone producing cells. Our findings suggest that changes in Wolbachia titer and tissue tropism can induce de novo premating isolation by directly or indirectly modulating sexual behavior of their native D. paulistorum hosts.}, }
@article {pmid30455292, year = {2018}, author = {Melnikov, SV and van den Elzen, A and Stevens, DL and Thoreen, CC and Söll, D}, title = {Loss of protein synthesis quality control in host-restricted organisms.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {49}, pages = {E11505-E11512}, pmid = {30455292}, issn = {1091-6490}, support = {R01 GM125955/GM/NIGMS NIH HHS/United States ; R35 GM122560/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Amino Acids ; Bacteria/*genetics/*metabolism ; Conserved Sequence ; Gene Expression Regulation, Bacterial/physiology ; Protein Biosynthesis ; Protein Domains ; RNA Editing ; }, abstract = {Intracellular organisms, such as obligate parasites and endosymbionts, typically possess small genomes due to continuous genome decay caused by an environment with alleviated natural selection. Previously, a few species with highly reduced genomes, including the intracellular pathogens Mycoplasma and Microsporidia, have been shown to carry degenerated editing domains in aminoacyl-tRNA synthetases. These defects in the protein synthesis machinery cause inaccurate translation of the genetic code, resulting in significant statistical errors in protein sequences that are thought to help parasites to escape immune response of a host. In this study we analyzed 10,423 complete bacterial genomes to assess conservation of the editing domains in tRNA synthetases, including LeuRS, IleRS, ValRS, ThrRS, AlaRS, and PheRS. We found that, while the editing domains remain intact in free-living species, they are degenerated in the overwhelming majority of host-restricted bacteria. Our work illustrates that massive genome erosion triggered by an intracellular lifestyle eradicates one of the most fundamental components of a living cell: the system responsible for proofreading of amino acid selection for protein synthesis. This finding suggests that inaccurate translation of the genetic code might be a general phenomenon among intercellular organisms with reduced genomes.}, }
@article {pmid30454555, year = {2018}, author = {Sapountzis, P and Zhukova, M and Shik, JZ and Schiott, M and Boomsma, JJ}, title = {Reconstructing the functions of endosymbiotic Mollicutes in fungus-growing ants.}, journal = {eLife}, volume = {7}, number = {}, pages = {}, pmid = {30454555}, issn = {2050-084X}, support = {323085/ERC_/European Research Council/International ; ERC Advanced Grant 323085/ERC_/European Research Council/International ; }, mesh = {Acetates/metabolism ; Animals ; Ants/*microbiology ; Arginine/metabolism ; Biotransformation ; Citrates/metabolism ; Glucose/metabolism ; Intestines/microbiology ; *Symbiosis ; Tenericutes/*physiology ; }, abstract = {Mollicutes, a widespread class of bacteria associated with animals and plants, were recently identified as abundant abdominal endosymbionts in healthy workers of attine fungus-farming leaf-cutting ants. We obtained draft genomes of the two most common strains harbored by Panamanian fungus-growing ants. Reconstructions of their functional significance showed that they are independently acquired symbionts, most likely to decompose excess arginine consistent with the farmed fungal cultivars providing this nitrogen-rich amino-acid in variable quantities. Across the attine lineages, the relative abundances of the two Mollicutes strains are associated with the substrate types that foraging workers offer to fungus gardens. One of the symbionts is specific to the leaf-cutting ants and has special genomic machinery to catabolize citrate/glucose into acetate, which appears to deliver direct metabolic energy to the ant workers. Unlike other Mollicutes associated with insect hosts, both attine ant strains have complete phage-defense systems, underlining that they are actively maintained as mutualistic symbionts.}, }
@article {pmid30448382, year = {2019}, author = {Herran, B and Cerveau, N and Houdelet, C and Bernier, C and Debenest, C and Delaunay, C and Raimond, M and Bertaux, J and Grève, P}, title = {IGFBP-rP1, a strongly conserved member of the androgenic hormone signalling pathway in Isopoda.}, journal = {General and comparative endocrinology}, volume = {272}, number = {}, pages = {9-19}, doi = {10.1016/j.ygcen.2018.11.006}, pmid = {30448382}, issn = {1095-6840}, mesh = {Androgens ; Animals ; Female ; Insulin-Like Growth Factor Binding Proteins/*genetics/*metabolism ; Isopoda/*metabolism ; Male ; Signal Transduction ; }, abstract = {The first protein which has been described to interact with the malacostracan Androgenic Gland Hormone (AGH) is a binding protein called IGFBP-rP1. It has been identified and studied in several species of decapods, in which its interaction with the masculinizing hormone and its expression patterns have been established in several ways. However, this protein remains uncharacterised to date in the other malacostracan orders, like Amphipoda and Isopoda, although they were historically the first ones in which the androgenic gland and the corresponding hormone were respectively described. In this article, we identified the IGFBP-rP1 of isopods and established its implication in the pathway of the AGH with a silencing approach in the model species Armadillidium vulgare. We also showed that this gene is expressed in all the tissues of males and females, with a similar pattern in animals infected with Wolbachia, a feminizing endosymbiont of several isopod species. The expression pattern did not differ during the development of uninfected and infected animals either. We finally studied the evolution of the IGFBP-rP1 in 68 isopod species, looking for conserved motifs and evidence of natural selection. Altogether, our results showed that this gene is constitutively expressed and strongly conserved in isopods, in which it likely constitutes a key element of the insulin/IGF signalling pathway. However, we also illustrated that IGFBP-rP1 is not sufficient on its own to explain the different developmental paths taken by the males and the females or feminized genetic males.}, }
@article {pmid30447617, year = {2018}, author = {Hines, HN and Onsbring, H and Ettema, TJG and Esteban, GF}, title = {Molecular Investigation of the Ciliate Spirostomum semivirescens, with First Transcriptome and New Geographical Records.}, journal = {Protist}, volume = {169}, number = {6}, pages = {875-886}, doi = {10.1016/j.protis.2018.08.001}, pmid = {30447617}, issn = {1618-0941}, mesh = {Chlorella/classification/genetics/isolation &amp; purification ; Ciliophora/*classification/genetics/*isolation &amp; purification/microbiology ; Codon, Terminator ; Endophytes/classification/genetics/isolation &amp; purification ; *Gene Expression Profiling ; *Phylogeography ; Protein Biosynthesis ; Sequence Analysis, RNA ; Sweden ; United Kingdom ; }, abstract = {The ciliate Spirostomum semivirescens is a large freshwater protist densely packed with endosymbiotic algae and capable of building a protective coating from surrounding particles. The species has been rarely recorded and it lacks any molecular investigations. We obtained such data from S. semivirescens isolated in the UK and Sweden. Using single-cell RNA sequencing of isolates from both countries, the transcriptome of S. semivirescens was generated. A phylogenetic analysis identified S. semivirescens as a close relative to S. minus. Additionally, rRNA sequence analysis of the green algal endosymbiont revealed that it is closely related to Chlorella vulgaris. Along with the molecular species identification, an analysis of the ciliates' stop codons was carried out, which revealed a relationship where TGA stop codon frequency decreased with increasing gene expression levels. The observed codon bias suggests that S. semivirescens could be in an early stage of reassigning the TGA stop codon. Analysis of the transcriptome indicates that S. semivirescens potentially uses rhodoquinol-dependent fumarate reduction to respire in the oxygen-depleted habitats where it lives. The data also shows that despite large geographical distances (over 1,600km) between the sampling sites investigated, a morphologically-identical species can share an exact molecular signature, suggesting that some ciliate species, even those over 1mm in size, could have a global biogeographical distribution.}, }
@article {pmid30426159, year = {2019}, author = {Mohanty, I and Rath, A and Swain, SP and Pradhan, N and Hazra, RK}, title = {Wolbachia Population in Vectors and Non-vectors: A Sustainable Approach Towards Dengue Control.}, journal = {Current microbiology}, volume = {76}, number = {2}, pages = {133-143}, pmid = {30426159}, issn = {1432-0991}, mesh = {Aedes/microbiology ; Animals ; Biological Control Agents ; Communicable Disease Control/*methods ; Dengue/*prevention &amp; control/transmission ; Female ; India ; Male ; Mosquito Vectors/classification/*microbiology ; Ovary/microbiology ; Polymerase Chain Reaction ; Prevalence ; Salivary Glands/microbiology ; Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia is gram negative obligate endosymbiont known for reproductive manipulation in the host. It is important to study the presence of natural Wolbachia in mosquitoes which can later help in understanding the effect of transfected strain on indigenous strain. With this view, the present study is undertaken to focus on the prevalence, diversity, infection frequencies, phylogeny and density of indigenous Wolbachia strains in wild mosquito species of Odisha. Our study confirms Wolbachia presence in Ae. albopictus, Cx. quinquefasciatus, Cx. vishnui, Cx. gelidus, Ar. subalbatus, Mn. uniformis, and Mn. indiana. Wolbachia in the above mosquitoes were separated into two supergroups (A and B). Ae. albopictus, the major vector of dengue and chikungungunya had both super-infection and mono-infection. The ovaries of Ae. albopictus were highest in density of Wolbachia as compared to midguts or salivary glands. wAlBA and wAlbB density were variable in mosquitoes of F1 generation for both the sex and at different age. We also found that Wolbachia super-infection in females tends to increase whereas wAlbA density reduced completely as compared to wAlbB in males when they grew old. Giemsa stained squashed ovaries revealed pink pleomorphic Wolbachia cells with different shapes and forms. This study is unique in its kind covering the major aspects of the endosymbiont Wolbachia and focusing on its potential as a biocontrol agent in arboviral outbreaks. Knowledge on potential of the indigenous strain and interactions between Wolbachia and viruses can be utilized further to reduce the global burden of vector borne diseases.}, }
@article {pmid30425149, year = {2018}, author = {Campbell, MA and Łukasik, P and Meyer, MC and Buckner, M and Simon, C and Veloso, C and Michalik, A and McCutcheon, JP}, title = {Changes in Endosymbiont Complexity Drive Host-Level Compensatory Adaptations in Cicadas.}, journal = {mBio}, volume = {9}, number = {6}, pages = {}, pmid = {30425149}, issn = {2150-7511}, support = {P20 GM103546/GM/NIGMS NIH HHS/United States ; }, mesh = {Alphaproteobacteria/genetics ; Animals ; Evolution, Molecular ; Female ; Genome, Bacterial ; Hemiptera/*microbiology/*physiology ; *Host Microbial Interactions ; Ovum/microbiology ; Phylogeny ; *Symbiosis ; }, abstract = {For insects that depend on one or more bacterial endosymbionts for survival, it is critical that these bacteria are faithfully transmitted between insect generations. Cicadas harbor two essential bacterial endosymbionts, "Candidatus Sulcia muelleri" and "Candidatus Hodgkinia cicadicola." In some cicada species, Hodgkinia has fragmented into multiple distinct but interdependent cellular and genomic lineages that can differ in abundance by more than two orders of magnitude. This complexity presents a potential problem for the host cicada, because low-abundance but essential Hodgkinia lineages risk being lost during the symbiont transmission bottleneck from mother to egg. Here we show that all cicada eggs seem to receive the full complement of Hodgkinia lineages, and that in cicadas with more complex Hodgkinia this outcome is achieved by increasing the number of Hodgkinia cells transmitted by up to 6-fold. We further show that cicada species with varying Hodgkinia complexity do not visibly alter their transmission mechanism at the resolution of cell biological structures. Together these data suggest that a major cicada adaptation to changes in endosymbiont complexity is an increase in the number of Hodgkinia cells transmitted to each egg. We hypothesize that the requirement to increase the symbiont titer is one of the costs associated with Hodgkinia fragmentation.IMPORTANCE Sap-feeding insects critically rely on one or more bacteria or fungi to provide essential nutrients that are not available at sufficient levels in their diets. These microbes are passed between insect generations when the mother places a small packet of microbes into each of her eggs before it is laid. We have previously described an unusual lineage fragmentation process in a nutritional endosymbiotic bacterium of cicadas called Hodgkinia In some cicadas, a single Hodgkinia lineage has split into numerous related lineages, each performing a subset of original function and therefore each required for normal host function. Here we test how this splitting process affects symbiont transmission to eggs. We find that cicadas dramatically increase the titer of Hodgkinia cells passed to each egg in response to lineage fragmentation, and we hypothesize that this increase in bacterial cell count is one of the major costs associated with endosymbiont fragmentation.}, }
@article {pmid30423824, year = {2018}, author = {Lv, N and Wang, L and Sang, W and Liu, CZ and Qiu, BL}, title = {Effects of Endosymbiont Disruption on the Nutritional Dynamics of the Pea Aphid Acyrthosiphon pisum.}, journal = {Insects}, volume = {9}, number = {4}, pages = {}, pmid = {30423824}, issn = {2075-4450}, abstract = {Pea aphid (Acyrthosiphon pisum) is a worldwide pest that feeds exclusively on the phloem sap of numerous host plants. It harbours a well-known primary endosymbiont Buchnera aphidicola that helps to overcome the nutritional deficiency of a plant-based diet. However, how the Buchnera contributes to the nutritional and energy metabolism of its aphid host is unclear to date. In the current study, the function of Buchnera in relation to nutritional synthesis of pea aphid was investigated by disrupting the primary endosymbiont with an antibiotic rifampicin. Our findings revealed that the disruption of Buchnera led to infertility and higher loss in body mass of aphid hosts. Body length and width were also decreased significantly compared to healthy aphids. The detection of nutrition indicated that the quantity of proteins, soluble sugars, and glycogen in aposymbiotic pea aphids increased slowly with the growth of the aphid host. In comparison, the quantities of all the nutritional factors were significantly lower than those of symbiotic pea aphids, while the quantity of total lipid and neutral fat in aposymbiotic pea aphids were distinctly higher than those of symbiotic ones. Thus, we concluded that the significant reduction of the total amount of proteins, soluble sugars, and glycogen and the significant increase of neutral fats in aposymbiotic pea aphids were due to the disruption of Buchnera, which confirmed that the function of Buchnera is irreplaceable in the pea aphid.}, }
@article {pmid30415881, year = {2019}, author = {Flores-Félix, JD and Sánchez-Juanes, F and García-Fraile, P and Valverde, A and Mateos, PF and Gónzalez-Buitrago, JM and Velázquez, E and Rivas, R}, title = {Phaseolus vulgaris is nodulated by the symbiovar viciae of several genospecies of Rhizobium laguerreae complex in a Spanish region where Lens culinaris is the traditionally cultivated legume.}, journal = {Systematic and applied microbiology}, volume = {42}, number = {2}, pages = {240-247}, doi = {10.1016/j.syapm.2018.10.009}, pmid = {30415881}, issn = {1618-0984}, mesh = {Bacterial Typing Techniques ; DNA, Bacterial/genetics ; Genes, Bacterial ; Phaseolus/*microbiology ; *Phylogeny ; Rhizobium/*classification/isolation &amp; purification ; Root Nodules, Plant/microbiology ; Sequence Analysis, DNA ; Soil Microbiology ; Spain ; }, abstract = {Phaseolus vulgaris and Lens culinaris are two legumes with different distribution centers that were introduced in Spain at different times, but in some regions L. culinaris has been traditionally cultivated and P. vulgaris did not. Here we analysed the rhizobia isolated from nodules of these two legumes in one of these regions. MALDI-TOF MS analysis showed that all isolated strains matched with Rhizobium laguerreae and the phylogenetic analysis of rrs, atpD and recA genes confirmed these results. The phylogenetic analysis of these core genes allowed the differentiation of several groups within R. laguerreae and unexpectedly, strains with housekeeping genes identical to that of the type strain of R. laguerreae presented some differences in the rrs gene. In some strains this gene contains an intervening sequence (IVS) identical to that found in Rhizobium strains nodulating several legumes in different geographical locations. The atpD, recA and nodC genes of all isolated strains clustered with those of strains nodulating L. culinaris in its distribution centers, but not with those nodulating P. vulgaris in theirs. Therefore, all these strains belong to the symbiovar viciae, including those isolated from P. vulgaris, which in the studied region established effective symbiosis with the common endosymbiont of L. culinaris, instead to with its common endosymbiont, the symbiovar phaseoli. These results are particularly interesting for biogeography studies, because they showed that, due its high promiscuity degree, P. vulgaris is able to establish symbiosis with local symbiovars well established in the soil after centuries of cultivation with other legumes.}, }
@article {pmid30414119, year = {2019}, author = {Schuler, H and Lopez, JA and Doellman, MM and Hood, GR and Egan, SP and Feder, JL}, title = {Target-Enriched Endosymbiont Sequencing (TEEseq): A New High-Throughput Sequencing Approach Applied to the Comprehensive Characterization of Endosymbionts.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {1858}, number = {}, pages = {195-212}, doi = {10.1007/978-1-4939-8775-7_14}, pmid = {30414119}, issn = {1940-6029}, mesh = {Animals ; Bacterial Proteins/genetics ; Computational Biology/*methods ; DNA, Bacterial/analysis/genetics ; *Genome, Bacterial ; High-Throughput Nucleotide Sequencing/*methods ; Insecta/*microbiology ; Sequence Analysis, DNA/methods ; *Symbiosis ; Wolbachia/*genetics/isolation &amp; purification/physiology ; }, abstract = {Intracellular bacteria are ubiquitous in the insect world, with perhaps the best-studied example being the alphaproteobacterium, Wolbachia. Like most endosymbionts, Wolbachia cannot be cultivated outside of its host cells, hindering traditional microbial characterization techniques. Furthermore, multiple Wolbachia strains can be present within a single host, and certain strains can be present in densities below the detection limit of current methods. To date, Wolbachia has most commonly been studied using polymerase chain reaction (PCR) amplification and Sanger DNA sequencing by targeting specific genes in the bacterium's genome. PCR amplification and Sanger sequencing of multiple Wolbachia strains requires analysis of individually cloned sequences, which is resource and labor intensive. To help mitigate these difficulties, we present a modified double digest restriction site associated DNA sequencing (ddRADseq) approach to target and sequence in parallel multiple genes by adding restriction enzyme recognition sites to gene-specific PCR primers. Adopting this strategy allows us to uniquely tag and sequence amplicons from multiple hosts simultaneously on an Illumina MiSeq platform. Our approach represents an efficient and cost-effective method to characterize multiple target genes in population surveys.}, }
@article {pmid30410449, year = {2018}, author = {Colella, S and Parisot, N and Simonet, P and Gaget, K and Duport, G and Baa-Puyoulet, P and Rahbé, Y and Charles, H and Febvay, G and Callaerts, P and Calevro, F}, title = {Bacteriocyte Reprogramming to Cope With Nutritional Stress in a Phloem Sap Feeding Hemipteran, the Pea Aphid Acyrthosiphon pisum.}, journal = {Frontiers in physiology}, volume = {9}, number = {}, pages = {1498}, pmid = {30410449}, issn = {1664-042X}, abstract = {Nutritional symbioses play a central role in the ability of insects to thrive on unbalanced diets and in ensuring their evolutionary success. A genomic model for nutritional symbiosis comprises the hemipteran Acyrthosiphon pisum, and the gamma-3-proteobacterium, Buchnera aphidicola, with genomes encoding highly integrated metabolic pathways. A. pisum feeds exclusively on plant phloem sap, a nutritionally unbalanced diet highly variable in composition, thus raising the question of how this symbiotic system responds to nutritional stress. We addressed this by combining transcriptomic, phenotypic and life history trait analyses to determine the organismal impact of deprivation of tyrosine and phenylalanine. These two aromatic amino acids are essential for aphid development, are synthesized in a metabolic pathway for which the aphid host and the endosymbiont are interdependent, and their concentration can be highly variable in plant phloem sap. We found that this nutritional challenge does not have major phenotypic effects on the pea aphid, except for a limited weight reduction and a 2-day delay in onset of nymph laying. Transcriptomic analyses through aphid development showed a prominent response in bacteriocytes (the core symbiotic tissue which houses the symbionts), but not in gut, thus highlighting the role of bacteriocytes as major modulators of this homeostasis. This response does not involve a direct regulation of tyrosine and phenylalanine biosynthetic pathway and transporter genes. Instead, we observed an extensive transcriptional reprogramming of the bacteriocyte with a rapid down-regulation of genes encoding sugar transporters and genes required for sugar metabolism. Consistently, we observed continued overexpression of the A. pisum homolog of RRAD, a small GTPase implicated in repressing aerobic glycolysis. In addition, we found increased transcription of genes involved in proliferation, cell size control and signaling. We experimentally confirmed the significance of these gene expression changes detecting an increase in bacteriocyte number and cell size in vivo under tyrosine and phenylalanine depletion. Our results support a central role of bacteriocytes in the aphid response to amino acid deprivation: their transcriptional and cellular responses fine-tune host physiology providing the host insect with an effective way to cope with the challenges posed by the variability in composition of phloem sap.}, }
@article {pmid30405656, year = {2018}, author = {Cissoko, M and Hocher, V and Gherbi, H and Gully, D and Carré-Mlouka, A and Sane, S and Pignoly, S and Champion, A and Ngom, M and Pujic, P and Fournier, P and Gtari, M and Swanson, E and Pesce, C and Tisa, LS and Sy, MO and Svistoonoff, S}, title = {Actinorhizal Signaling Molecules: Frankia Root Hair Deforming Factor Shares Properties With NIN Inducing Factor.}, journal = {Frontiers in plant science}, volume = {9}, number = {}, pages = {1494}, pmid = {30405656}, issn = {1664-462X}, abstract = {Actinorhizal plants are able to establish a symbiotic relationship with Frankia bacteria leading to the formation of root nodules. The symbiotic interaction starts with the exchange of symbiotic signals in the soil between the plant and the bacteria. This molecular dialog involves signaling molecules that are responsible for the specific recognition of the plant host and its endosymbiont. Here we studied two factors potentially involved in signaling between Frankia casuarinae and its actinorhizal host Casuarina glauca: (1) the Root Hair Deforming Factor (CgRHDF) detected using a test based on the characteristic deformation of C. glauca root hairs inoculated with F. casuarinae and (2) a NIN activating factor (CgNINA) which is able to activate the expression of CgNIN, a symbiotic gene expressed during preinfection stages of root hair development. We showed that CgRHDF and CgNINA corresponded to small thermoresistant molecules. Both factors were also hydrophilic and resistant to a chitinase digestion indicating structural differences from rhizobial Nod factors (NFs) or mycorrhizal Myc-LCOs. We also investigated the presence of CgNINA and CgRHDF in 16 Frankia strains representative of Frankia diversity. High levels of root hair deformation (RHD) and activation of ProCgNIN were detected for Casuarina-infective strains from clade Ic and closely related strains from clade Ia unable to nodulate C. glauca. Lower levels were present for distantly related strains belonging to clade III. No CgRHDF or CgNINA could be detected for Frankia coriariae (Clade II) or for uninfective strains from clade IV.}, }
@article {pmid30398619, year = {2018}, author = {Hagen, R and Verhoeve, VI and Gillespie, JJ and Driscoll, TP}, title = {Conjugative Transposons and Their Cargo Genes Vary across Natural Populations of Rickettsia buchneri Infecting the Tick Ixodes scapularis.}, journal = {Genome biology and evolution}, volume = {10}, number = {12}, pages = {3218-3229}, pmid = {30398619}, issn = {1759-6653}, support = {R01 AI017828/AI/NIAID NIH HHS/United States ; R01 AI126853/AI/NIAID NIH HHS/United States ; R21 AI126108/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Female ; *Gene Amplification ; Genetic Variation ; Genome, Bacterial ; *Interspersed Repetitive Sequences ; Ixodes/*microbiology ; Male ; Rickettsia/*genetics ; Species Specificity ; }, abstract = {Rickettsia buchneri (formerly Rickettsia endosymbiont of Ixodes scapularis, or REIS) is an obligate intracellular endoparasite of the black-legged tick, the primary vector of Lyme disease in North America. It is noteworthy among the rickettsiae for its relatively large genome (1.8 Mb) and extraordinary proliferation of mobile genetic elements (MGEs), which comprise nearly 35% of its genome. Previous analysis of the R. buchneri genome identified several integrative conjugative elements named Rickettsiales amplified genomic elements (RAGEs); the composition of these RAGEs suggests that continued genomic invasions by MGEs facilitated the proliferation of rickettsial genes related to an intracellular lifestyle. In this study, we compare the genomic diversity at RAGE loci among sequenced rickettsiae that infect three related Ixodes spp., including two strains of R. buchneri and Rickettsia endosymbiont of Ixodes pacificus strain Humboldt, as well as a closely related species R. tamurae infecting Amblyomma testudinarium ticks. We further develop a novel multiplex droplet digital PCR assay and use it to quantify copy number ratios of chromosomal R. buchneri RAGE-A and RAGE-B to the single-copy gene gltA within natural populations of I. scapularis. Our results reveal substantial diversity among R. buchneri at these loci, both within individual ticks as well as in the I. scapularis population at large, demonstrating that genomic rearrangement of MGEs is an active process in these intracellular bacteria.}, }
@article {pmid30391314, year = {2019}, author = {Konecka, E and Olszanowski, Z}, title = {A new Cardinium group of bacteria found in Achipteria coleoptrata (Acari: Oribatida).}, journal = {Molecular phylogenetics and evolution}, volume = {131}, number = {}, pages = {64-71}, doi = {10.1016/j.ympev.2018.10.043}, pmid = {30391314}, issn = {1095-9513}, mesh = {Animals ; Bacteroidetes/*physiology ; Base Sequence ; DNA, Ribosomal/genetics ; Likelihood Functions ; Mites/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {The understanding of the biology of arthropods requires an understanding of their bacterial associates. We determined the distribution of bacteria Wolbachia sp., Rickettsia sp., Cardinium sp., Spiroplasma sp., Arsenophonus sp., Hamiltonella sp., and Flavobacterium in oribatid mites (Acari: Oribatida). We identified Cardinium sp. in Achipteria coleoptrata. This is the first report of this bacterium in A. coleoptrata. Approximately 30% of the mite population was infected by Cardinium sp. The Cardinium 16S rDNA was examined for the presence of two sequences unique for this microorganism. One of them was noted in Cardinium sp. of A. coleoptrata. In the second sequence, we found nucleotide substitution in the 7th position: A instead of T. In our opinion, this demonstrated the unique nature of Cardinium sp. of A. coleoptrata. We also determined phylogenetic relationship between Cardinium sp., including the strain found in A. coleoptrata by studying the 16S rRNA and gyrB gene sequences. It revealed that Cardinium from A. coleoptrata did not cluster together with strains from groups A, B, C or D, and constituted a separate clade E. These observations make A. coleoptrata a unique Cardinium host in terms of the distinction of the strain.}, }
@article {pmid30384840, year = {2018}, author = {Ying, H and Cooke, I and Sprungala, S and Wang, W and Hayward, DC and Tang, Y and Huttley, G and Ball, EE and Forêt, S and Miller, DJ}, title = {Comparative genomics reveals the distinct evolutionary trajectories of the robust and complex coral lineages.}, journal = {Genome biology}, volume = {19}, number = {1}, pages = {175}, pmid = {30384840}, issn = {1474-760X}, mesh = {Animals ; Anthozoa/*classification/*genetics ; *Biological Evolution ; Genome ; Genome, Mitochondrial ; Genomics/*methods ; Phylogeny ; }, abstract = {BACKGROUND: Despite the biological and economic significance of scleractinian reef-building corals, the lack of large molecular datasets for a representative range of species limits understanding of many aspects of their biology. Within the Scleractinia, based on molecular evidence, it is generally recognised that there are two major clades, Complexa and Robusta, but the genomic bases of significant differences between them remain unclear.<br><br>RESULTS: Draft genome assemblies and annotations were generated for three coral species: Galaxea fascicularis (Complexa), Fungia sp., and Goniastrea aspera (Robusta). Whilst phylogenetic analyses strongly support a deep split between Complexa and Robusta, synteny analyses reveal a high level of gene order conservation between all corals, but not between corals and sea anemones or between sea anemones. HOX-related gene clusters are, however, well preserved across all of these combinations. Differences between species are apparent in the distribution and numbers of protein domains and an apparent correlation between number of HSP20 proteins and stress tolerance. Uniquely amongst animals, a complete histidine biosynthesis pathway is present in robust corals but not in complex corals or sea anemones. This pathway appears to be ancestral, and its retention in the robust coral lineage has important implications for coral nutrition and symbiosis.<br><br>CONCLUSIONS: The availability of three new coral genomes enabled&#xa0;recognition of a de novo histidine biosynthesis pathway in robust corals which is only the second identified biosynthetic difference between corals. These datasets provide a platform for understanding many aspects of coral biology, particularly the interactions of corals with their endosymbionts.}, }
@article {pmid30374735, year = {2019}, author = {Hashmi, TR and Devi, SR and Ahmad, A and Meshram, NM and Prasad, R}, title = {Genetic Status and Endosymbionts Diversity of Bemisia tabaci (Gennadius) on Hosts Belonging to Family Malvaceae in India.}, journal = {Neotropical entomology}, volume = {48}, number = {2}, pages = {207-218}, pmid = {30374735}, issn = {1678-8052}, mesh = {Abelmoschus ; Animals ; Bacteria/*classification ; DNA Primers ; Gossypium ; Hemiptera/*microbiology ; India ; *Malvaceae ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {A study was instigated to examine the genetic status and distribution of known endosymbionts namely Portiera, Rickettsia, Wolbachia, Cardinium, and Arsenophonus in the populations of Bemisia tabaci (Gennadius) from three host plants: cotton (Gossypium herbaceum), okra (Abelmoschus esculentus L.), and China rose (Hibiscus rosa-sinensis) belonging to the family Malvaceae. The presence of four secondary endosymbionts Rickettsia, Wolbachia, Cardinium, and Arsenophonus was checked in Bemisia tabaci populations. Phylogenetic analyses grounded on the mitochondrial cytochrome oxidase I gene (mtCO1) unveiled the presence of Asia 1, Asia II 1, and Asia II 7 genetic groups for Bemisia tabaci on abovementioned crops. Individuals were examined for symbiotic bacterial infection with specific primers amplifying the 16S rRNA gene for Portiera, Rickettsia, Cardinium, and Wolbachia, and the 23S rRNA gene for Arsenophonus. The results show that Portiera was present in all the Bemisia tabaci samples. However, variations were noted in the circulation frequencies of secondary endosymbionts among the Bemisia tabaci populations. A significant difference was noticed in the distribution frequency of Rickettsia between cotton and China rose or okra with their p values as 0.016 and 0.033 respectively. The uneven incidence of secondary endosymbionts ropes the assumption that each endosymbiotic bacterium not only has a role in the endurance but may contribute to the polyphagous nature of Bemisia tabaci. It also brings an uncomplicated evidence for progressive studies on control measures of this notorious insect pest.}, }
@article {pmid30374192, year = {2018}, author = {Estes, AM and Hearn, DJ and Agrawal, S and Pierson, EA and Dunning Hotopp, JC}, title = {Comparative genomics of the Erwinia and Enterobacter olive fly endosymbionts.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {15936}, pmid = {30374192}, issn = {2045-2322}, mesh = {Base Composition ; Enterobacter/*genetics ; Erwinia/*genetics ; *Genome, Bacterial ; Genomics/*methods ; Nitrogen/metabolism ; Olea/microbiology ; RNA, Ribosomal, 16S/chemistry/genetics/metabolism ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The pestivorous tephritid olive fly has long been known as a frequent host of the obligately host-associated bacterial endosymbiont, Erwinia dacicola, as well as other facultative endosymbionts. The genomes of Erwinia dacicola and Enterobacter sp. OLF, isolated from a California olive fly, encode the ability to supplement amino acids and vitamins missing from the olive fruit on which the larvae feed. The Enterobacter sp. OLF genome encodes both uricase and ureases, and the Er. dacicola genome encodes an allantoate transport pathway, suggesting that bird feces or recycling the fly's waste products may be important sources of nitrogen. No homologs to known nitrogenases were identified in either bacterial genome, despite suggestions of their presence from experiments with antibiotic-treated flies. Comparisons between the olive fly endosymbionts and their free-living relatives revealed similar GC composition and genome size. The Er. dacicola genome has fewer genes for amino acid metabolism, cell motility, and carbohydrate transport and metabolism than free-living Erwinia spp. while having more genes for cell division, nucleotide metabolism and replication as well as mobile elements. A 6,696 bp potential lateral gene transfer composed primarily of amino acid synthesis and transport genes was identified that is also observed in Pseudomonas savastanoii pv savastanoii, the causative agent of olive knot disease.}, }
@article {pmid30373839, year = {2018}, author = {Mehta, AP and Supekova, L and Chen, JH and Pestonjamasp, K and Webster, P and Ko, Y and Henderson, SC and McDermott, G and Supek, F and Schultz, PG}, title = {Engineering yeast endosymbionts as a step toward the evolution of mitochondria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {46}, pages = {11796-11801}, pmid = {30373839}, issn = {1091-6490}, support = {P41 GM103445/GM/NIGMS NIH HHS/United States ; }, mesh = {Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Bioengineering/*methods ; Biological Evolution ; Escherichia coli/genetics/metabolism ; Mitochondria/*genetics/metabolism ; Models, Biological ; Saccharomyces cerevisiae/genetics/metabolism ; Symbiosis/*genetics ; Thiamine/metabolism ; }, abstract = {It has been hypothesized that mitochondria evolved from a bacterial ancestor that initially became established in an archaeal host cell as an endosymbiont. Here we model this first stage of mitochondrial evolution by engineering endosymbiosis between Escherichia coli and Saccharomyces cerevisiae An ADP/ATP translocase-expressing E. coli provided ATP to a respiration-deficient cox2 yeast mutant and enabled growth of a yeast-E. coli chimera on a nonfermentable carbon source. In a reciprocal fashion, yeast provided thiamin to an endosymbiotic E. coli thiamin auxotroph. Expression of several SNARE-like proteins in E. coli was also required, likely to block lysosomal degradation of intracellular bacteria. This chimeric system was stable for more than 40 doublings, and GFP-expressing E. coli endosymbionts could be observed in the yeast by fluorescence microscopy and X-ray tomography. This readily manipulated system should allow experimental delineation of host-endosymbiont adaptations that occurred during evolution of the current, highly reduced mitochondrial genome.}, }
@article {pmid30368822, year = {2019}, author = {Sun, X and Chen, W and Ivanov, S and MacLean, AM and Wight, H and Ramaraj, T and Mudge, J and Harrison, MJ and Fei, Z}, title = {Genome and evolution of the arbuscular mycorrhizal fungus Diversispora epigaea (formerly Glomus versiforme) and its bacterial endosymbionts.}, journal = {The New phytologist}, volume = {221}, number = {3}, pages = {1556-1573}, doi = {10.1111/nph.15472}, pmid = {30368822}, issn = {1469-8137}, support = {1237993//US National Science Foundation, Plant Genome Research program/International ; DE-SC0012460//Office of Science, Office of Biological and Environmental Research/International ; 2014-67013-21571//National Institute of Food and Agriculture/International ; }, mesh = {*Biological Evolution ; Gene Duplication ; Gene Transfer, Horizontal/genetics ; Genes, Fungal ; *Genome, Fungal ; Glomeromycota/*genetics/metabolism ; Multigene Family ; Mycoplasma/*physiology ; Mycorrhizae/*genetics ; Phylogeny ; Spores, Fungal/physiology ; Symbiosis/*genetics ; Tenericutes/*physiology ; }, abstract = {Arbuscular mycorrhizal (AM) fungi form endosymbioses with most plants, and they themselves are hosts for Mollicutes/Mycoplasma-related endobacteria (MRE). Despite their significance, genomic information for AM fungi and their MRE are relatively sparse, which hinders our understanding of their biology and evolution. We assembled the genomes of the AM fungus Diversispora epigaea (formerly Glomus versiforme) and its MRE and performed comparative genomics and evolutionary analyses. The D. epigaea genome showed a pattern of substantial gene duplication and differential evolution of gene families, including glycosyltransferase family 25, whose activities are exclusively lipopolysaccharide biosynthesis. Genes acquired by horizontal transfer from bacteria possibly function in defense against foreign DNA or viruses. The MRE population was diverse, with multiple genomes displaying characteristics of differential evolution and encoding many MRE-specific genes as well as genes of AM fungal origin. Gene family expansion in D. epigaea may enhance adaptation to both external and internal environments, such as expansion of kinases for signal transduction upon external stimuli and expansion of nucleoside salvage pathway genes potentially for competition with MRE, whose genomes lack purine and pyrimidine biosynthetic pathways. Collectively, this metagenome provides high-quality references and begins to reveal the diversity within AM fungi and their MRE.}, }
@article {pmid30358445, year = {2018}, author = {Sigwart, JD and Chen, C}, title = {Comparative Oxygen Consumption of Gastropod Holobionts from Deep-Sea Hydrothermal Vents in the Indian Ocean.}, journal = {The Biological bulletin}, volume = {235}, number = {2}, pages = {102-112}, doi = {10.1086/699326}, pmid = {30358445}, issn = {1939-8697}, mesh = {Animals ; Gastropoda/*metabolism ; *Hydrothermal Vents ; Indian Ocean ; Oxygen Consumption/*physiology ; Symbiosis/*physiology ; Temperature ; }, abstract = {Physiological traits are the foundation of an organism's success in a dynamic environment, yet basic measurements are unavailable for many taxa and even ecosystems. We measured routine metabolism in two hydrothermal vent gastropods, Alviniconcha marisindica (n = 40) and the scaly-foot gastropod Chrysomallon squamiferum (n = 18), from Kairei and Edmond vent fields on the Central Indian Ridge (23-25°S, about 3000 meter depth). No previous studies have measured metabolism in any Indian Ocean vent animals. After recovering healthy animals to the surface, we performed shipboard closed-chamber respirometry experiments to compare oxygen uptake at different temperatures (10, 16, and 25 °C) at surface pressure (1 atm). The physiology of these species is driven by the demands of their chemoautotrophic symbionts. Chrysomallon has very enlarged respiratory and circulatory systems, and endosymbionts are housed in its trophosome-like internal esophageal gland. By contrast, Alviniconcha has chemoautotrophic bacteria within the gill and less extensive associated anatomical adaptations. Thus, we predicted that routine oxygen consumption of Chrysomallon might be higher than that of Alviniconcha. However, oxygen consumption of Chrysomallon was not higher than that of Alviniconcha, and, further, Chrysomallon maintained a steady metabolic demand in two widely separated experimental temperatures, while Alviniconcha did not. We interpret that these findings indicate that (1) the "trophosome" does not fundamentally increase oxygen requirement compared to other gastropod holobionts, and (2) cold temperatures (10 °C) induce a stress response in Alviniconcha, resulting in aberrantly high uptake. While these two large gastropod species co-occur, differences in oxygen consumption may reflect the separate niches they occupy in the vent ecosystem.}, }
@article {pmid30358065, year = {2018}, author = {Paris, Z and Alfonzo, JD}, title = {How the intracellular partitioning of tRNA and tRNA modification enzymes affects mitochondrial function.}, journal = {IUBMB life}, volume = {70}, number = {12}, pages = {1207-1213}, pmid = {30358065}, issn = {1521-6551}, support = {R01 GM084065/GM/NIGMS NIH HHS/United States ; R56 AI131248/AI/NIAID NIH HHS/United States ; U01 AI131348/AI/NIAID NIH HHS/United States ; }, mesh = {Cytoplasm/genetics ; Genome, Mitochondrial/*genetics ; Intracellular Membranes ; Mitochondria/*genetics ; Mitochondrial Membranes/metabolism ; Protein Biosynthesis/*genetics ; RNA Processing, Post-Transcriptional/genetics ; RNA, Transfer/*genetics ; Symbiosis/genetics ; }, abstract = {Organisms have evolved different strategies to seclude certain molecules to specific locations of the cell. This is most pronounced in eukaryotes with their extensive intracellular membrane systems. Intracellular compartmentalization is particularly critical in genome containing organelles, which because of their bacterial evolutionary ancestry still maintain protein-synthesis machinery that resembles more their evolutionary origin than the extant eukaryotic cell they once joined as an endosymbiont. Despite this, it is clear that genome-containing organelles such as the mitochondria are not in isolation and many molecules make it across the mitochondrial membranes from the cytoplasm. In this realm the import of tRNAs and the enzymes that modify them prove most consequential. In this review, we discuss two recent examples of how modifications typically found in cytoplasmic tRNAs affect mitochondrial translation in organisms that forcibly import all their tRNAs from the cytoplasm. In our view, the combination of tRNA import and the compartmentalization of modification enzymes must have played a critical role in the evolution of the organelle. © 2018 IUBMB Life, 70(12):1207-1213, 2018.}, }
@article {pmid30356282, year = {2018}, author = {Chan, LL and Mak, JW and Ambu, S and Chong, PY}, title = {Identification and ultrastructural characterization of Acanthamoeba bacterial endocytobionts belonging to the Alphaproteobacteria class.}, journal = {PloS one}, volume = {13}, number = {10}, pages = {e0204732}, pmid = {30356282}, issn = {1932-6203}, mesh = {Acanthamoeba/*genetics ; Alphaproteobacteria/*genetics ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Genome, Bacterial/genetics ; Host-Pathogen Interactions/genetics ; Microscopy, Electron, Transmission/methods ; RNA, Ribosomal, 16S/genetics ; }, abstract = {The detection and identification of two endocytobiotic bacterial strains, one affiliated to the "Candidatus Caedibacter acanthamoebae"/"Ca. Paracaedimonas acanthamoeba", and another to the endosymbiont of Acanthamoeba UWC8 and "Ca. Jidaibacter acanthamoeba" are described. For endocytobiont screening, we developed a PCR method with a set of broad-range bacterial 16S rRNA primers to substitute the commonly used but technically demanding fluorescent in situ hybridization technique. Our PCR test alone without sequencing failed to discriminate the endocytobiont-containing and endocytobiont-free Acanthamoeba sp. due to the presence of mismatched primers to host mitochondrial DNA. We highlighted the need to perform bacterial primer checking against the Acanthamoeba genome to avoid false positive detection in PCR. Although the genetic aspect of "Ca. Caedibacter acanthamoebae"/"Ca. Paracaedimonas acanthamoeba" and the endosymbiont of Acanthamoeba UWC8/"Ca. Jidaibacter acanthamoeba" are well studied, knowledge pertaining to their morphologies are quite vague. Hence, we used transmission electron microscopy to examine our endocytobionts which are affiliated to previously described intracellular bacteria of Acanthamoeba sp. We used good-quality TEM images for the localization and the fate of the current endocytobionts inside different life stages of the hosts. Furthermore, to the best of our knowledge, our TEM findings are the first to provide morphological evidence for the clearance of defective Acanthamoeba endocytobionts via an autophagic-like process.}, }
@article {pmid30337547, year = {2018}, author = {Morioka, E and Oida, M and Tsuchida, T and Ikeda, M}, title = {Nighttime activities and peripheral clock oscillations depend on Wolbachia endosymbionts in flies.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {15432}, pmid = {30337547}, issn = {2045-2322}, support = {JP16H04651//Japan Society for the Promotion of Science (JSPS)/International ; JP16H04651//Japan Society for the Promotion of Science (JSPS)/International ; }, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Circadian Clocks/genetics/*physiology ; Circadian Rhythm/genetics/*physiology ; Crosses, Genetic ; Drosophila Proteins/genetics ; Drosophila melanogaster/*microbiology/physiology ; Female ; Genes, Reporter ; *Host Microbial Interactions ; Locomotion/*physiology/radiation effects ; Male ; Period Circadian Proteins/genetics ; Photic Stimulation ; Symbiosis/physiology ; Tetracycline/pharmacology ; Wolbachia/drug effects/*physiology ; }, abstract = {Wolbachia are ubiquitous bacterial endosymbionts of arthropods and affect host gene expression. Although Wolbachia infections were suggested to modulate sleep in flies, their influence on the circadian clock remained obscure. Here, we screened bacterial symbionts in a laboratory Drosophila melanogaster colony, and observed widespread infections of wMel strain Wolbachia. We established a Wolbachia-free strain from a clock gene reporter strain, period-luciferase (per-luc). Temperature (19-29 °C)-compensated free-running periods were detected regardless of infections which may reflect the lack of wMel infections in central circadian pacemaker neurons. However, locomotor activity levels during the night or subjective night were significantly amplified in uninfected flies. Moreover, the behavioral phenotype of F1 offspring of an uninfected female and infected male resembled that of uninfected flies. This trait is consistent with maternal transmission of Wolbachia infection. Interestingly, per-luc activities in headless bodies, as an index of peripheral circadian oscillators, were severely damped in uninfected flies. Additionally, circadian amplitudes of PER immunoreactivities in Malpighian tubules were reduced in uninfected flies. These results demonstrate that Wolbachia boost fly peripheral clock oscillations and diurnal behavioral patterns. Genetic mechanisms underlying behavioral rhythms have been widely analyzed using mutant flies whereas screening of Wolbachia will be necessary for future studies.}, }
@article {pmid30323231, year = {2018}, author = {Cenci, U and Qiu, H and Pillonel, T and Cardol, P and Remacle, C and Colleoni, C and Kadouche, D and Chabi, M and Greub, G and Bhattacharya, D and Ball, SG}, title = {Host-pathogen biotic interactions shaped vitamin K metabolism in Archaeplastida.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {15243}, pmid = {30323231}, issn = {2045-2322}, mesh = {Archaea/genetics/metabolism ; Cyanobacteria/classification/*genetics/*metabolism ; Eukaryotic Cells/metabolism ; Evolution, Molecular ; Gene Transfer, Horizontal ; Genome, Plastid ; Host-Pathogen Interactions/*genetics ; Metabolic Networks and Pathways/genetics ; Phylogeny ; Plastids/*genetics ; Rhodophyta/genetics/metabolism ; Symbiosis/physiology ; Vitamin K/*metabolism ; }, abstract = {Menaquinone (vitamin K2) shuttles electrons between membrane-bound respiratory complexes under microaerophilic conditions. In photosynthetic eukaryotes and cyanobacteria, phylloquinone (vitamin K1) participates in photosystem I function. Here we elucidate the evolutionary history of vitamin K metabolism in algae and plants. We show that Chlamydiales intracellular pathogens made major genetic contributions to the synthesis of the naphthoyl ring core and the isoprenoid side-chain of these quinones. Production of the core in extremophilic red algae is under control of a menaquinone (Men) gene cluster consisting of 7 genes that putatively originated via lateral gene transfer (LGT) from a chlamydial donor to the plastid genome. In other green and red algae, functionally related nuclear genes also originated via LGT from a non-cyanobacterial, albeit unidentified source. In addition, we show that 3-4 of the 9 required steps for synthesis of the isoprenoid side chains are under control of genes of chlamydial origin. These results are discussed in the light of the hypoxic response experienced by the cyanobacterial endosymbiont when it gained access to the eukaryotic cytosol.}, }
@article {pmid30319574, year = {2018}, author = {Santos-Garcia, D and Juravel, K and Freilich, S and Zchori-Fein, E and Latorre, A and Moya, A and Morin, S and Silva, FJ}, title = {To B or Not to B: Comparative Genomics Suggests Arsenophonus as a Source of B Vitamins in Whiteflies.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {2254}, pmid = {30319574}, issn = {1664-302X}, abstract = {Insect lineages feeding on nutritionally restricted diets such as phloem sap, xylem sap, or blood, were able to diversify by acquiring bacterial species that complement lacking nutrients. These bacteria, considered obligate/primary endosymbionts, share a long evolutionary history with their hosts. In some cases, however, these endosymbionts are not able to fulfill all of their host's nutritional requirements, driving the acquisition of additional symbiotic species. Phloem-feeding members of the insect family Aleyrodidae (whiteflies) established an obligate relationship with Candidatus Portiera aleyrodidarum, which provides its hots with essential amino acids and carotenoids. In addition, many whitefly species harbor additional endosymbionts which may potentially further supplement their host's diet. To test this hypothesis, genomes of several endosymbionts of the whiteflies Aleurodicus dispersus, Aleurodicus floccissimus and Trialeurodes vaporariorum were analyzed. In addition to Portiera, all three species were found to harbor one Arsenophonus and one Wolbachia endosymbiont. A comparative analysis of Arsenophonus genomes revealed that although all three are capable of synthesizing B vitamins and cofactors, such as pyridoxal, riboflavin, or folate, their genomes and phylogenetic relationship vary greatly. Arsenophonus of A. floccissimus and T. vaporariorum belong to the same clade, and display characteristics of facultative endosymbionts, such as large genomes (3 Mb) with thousands of genes and pseudogenes, intermediate GC content, and mobile genetic elements. In contrast, Arsenophonus of A. dispersus belongs to a different lineage and displays the characteristics of a primary endosymbiont-a reduced genome (670 kb) with ~400 genes, 32% GC content, and no mobile genetic elements. However, the presence of 274 pseudogenes suggests that this symbiotic association is more recent than other reported primary endosymbionts of hemipterans. The gene repertoire of Arsenophonus of A. dispersus is completely integrated in the symbiotic consortia, and the biosynthesis of most vitamins occurs in shared pathways with its host. In addition, Wolbachia endosymbionts have also retained the ability to produce riboflavin, flavin adenine dinucleotide, and folate, and may make a nutritional contribution. Taken together, our results show that Arsenophonus hold a pivotal place in whitefly nutrition by their ability to produce B vitamins.}, }
@article {pmid30313172, year = {2018}, author = {GÜrellİ, G and Mohamed, ARA}, title = {Ciliated Protozoan Fauna in the Forestomach of Dromedary Camels (Camelus dromedarius) in Libya.}, journal = {Zootaxa}, volume = {4434}, number = {3}, pages = {429-440}, doi = {10.11646/zootaxa.4434.3.2}, pmid = {30313172}, issn = {1175-5334}, mesh = {Animals ; *Camelus ; Ciliophora ; Libya ; Myxozoa ; Rumen ; }, abstract = {Species composition and distribution of ciliated protozoa obtained from the forestomach of 20 dromedary camels living in Zawiya, Libya were examined. Nineteen species and 10 morphotypes belonging to eight genera were identified. The mean number of ciliates was 54.2 ± 32.9 × 104 cells ml-1 in the forestomach contents, and the mean number of ciliate species per host was 6.5 ± 2.9. Entodinium and Epidinium were the main genera, as these ciliates were found consistently at higher proportions than those of the other genera. In contrast, Ophryoscolex and Polyplastron were only observed at low frequencies. Diplodinium rangiferi, Entodinium ellipsoideum, E. simulans, and Polyplastron multivesiculatum were new endosymbionts recorded from camels.}, }
@article {pmid30311675, year = {2018}, author = {Leftwich, PT and Hutchings, MI and Chapman, T}, title = {Diet, Gut Microbes and Host Mate Choice: Understanding the significance of microbiome effects on host mate choice requires a case by case evaluation.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {40}, number = {12}, pages = {e1800053}, doi = {10.1002/bies.201800053}, pmid = {30311675}, issn = {1521-1878}, support = {BB/K000489/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Alleles ; Animals ; Biological Evolution ; *Diet ; Drosophila melanogaster/physiology ; Female ; Gastrointestinal Microbiome/*physiology ; Male ; Mating Preference, Animal/*physiology ; Symbiosis ; Wolbachia/physiology ; }, abstract = {All organisms live in close association with microbes. However, not all such associations are meaningful in an evolutionary context. Current debate concerns whether hosts and microbes are best described as communities of individuals or as holobionts (selective units of hosts plus their microbes). Recent reports that assortative mating of hosts by diet can be mediated by commensal gut microbes have attracted interest as a potential route to host reproductive isolation (RI). Here, the authors discuss logical problems with this line of argument. The authors briefly review how microbes can affect host mating preferences and evaluate recent findings from fruitflies. Endosymbionts can potentially influence host RI given stable and recurrent co-association of hosts and microbes over evolutionary time. However, observations of co-occurrence of microbes and hosts are ripe for misinterpretation and such associations will rarely represent a meaningful holobiont. A framework in which hosts and their microbes are independent evolutionary units provides the only satisfactory explanation for the observed range of effects and associations.}, }
@article {pmid30311439, year = {2019}, author = {Zhu, YX and Song, YL and Hoffmann, AA and Jin, PY and Huo, SM and Hong, XY}, title = {A change in the bacterial community of spider mites decreases fecundity on multiple host plants.}, journal = {MicrobiologyOpen}, volume = {8}, number = {6}, pages = {e00743}, pmid = {30311439}, issn = {2045-8827}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Female ; Fertility ; Host Specificity ; Male ; *Microbiota ; Plants/parasitology ; Spiroplasma/classification/genetics/isolation &amp; purification ; Tetranychidae/*microbiology/*physiology ; Wolbachia/classification/genetics/isolation &amp; purification ; }, abstract = {Bacterial symbionts may influence the fitness of their herbivore hosts, but such effects have been poorly studied across most invertebrate groups. The spider mite, Tetranychus truncatus, is a polyphagous agricultural pest harboring various bacterial symbionts whose function is largely unknown. Here, by using a high-throughput 16S rRNA amplicon sequencing approach, we characterized the bacterial diversity and community composition of spider mites fed on five host plants after communities were modified following tetracycline exposure. We demonstrated that spider mite bacterial diversity and community composition were significantly affected by host plants and antibiotics. In particular, the abundance of the maternally inherited endosymbionts Wolbachia and Spiroplasma significantly differed among spider mites that were reared on different plant species and were completely removed by antibiotics. There was an overall tendency for daily fecundity to be lower in the mites with reduced bacterial diversity following the antibiotic treatment. Our data suggest that host plants and antibiotics can shape spider mite bacterial communities and that bacterial symbionts improve mite performance.}, }
@article {pmid30309901, year = {2018}, author = {Kikuchi, S and Asakura, Y and Imai, M and Nakahira, Y and Kotani, Y and Hashiguchi, Y and Nakai, Y and Takafuji, K and Bédard, J and Hirabayashi-Ishioka, Y and Mori, H and Shiina, T and Nakai, M}, title = {A Ycf2-FtsHi Heteromeric AAA-ATPase Complex Is Required for Chloroplast Protein Import.}, journal = {The Plant cell}, volume = {30}, number = {11}, pages = {2677-2703}, pmid = {30309901}, issn = {1532-298X}, mesh = {Adenosine Triphosphate/metabolism ; Chloroplast Proteins/*metabolism ; Chloroplasts/metabolism ; Malate Dehydrogenase/metabolism ; Plant Proteins/*metabolism ; Protein Transport ; }, abstract = {Chloroplasts import thousands of nucleus-encoded preproteins synthesized in the cytosol through the TOC and TIC translocons on the outer and inner envelope membranes, respectively. Preprotein translocation across the inner membrane requires ATP; however, the import motor has remained unclear. Here, we report that a 2-MD heteromeric AAA-ATPase complex associates with the TIC complex and functions as the import motor, directly interacting with various translocating preproteins. This 2-MD complex consists of a protein encoded by the previously enigmatic chloroplast gene ycf2 and five related nuclear-encoded FtsH-like proteins, namely, FtsHi1, FtsHi2, FtsHi4, FtsHi5, and FtsH12. These components are each essential for plant viability and retain the AAA-type ATPase domain, but only FtsH12 contains the zinc binding active site generally conserved among FtsH-type metalloproteases. Furthermore, even the FtsH12 zinc binding site is dispensable for its essential function. Phylogenetic analyses suggest that all AAA-type members of the Ycf2/FtsHi complex including Ycf2 evolved from the chloroplast-encoded membrane-bound AAA-protease FtsH of the ancestral endosymbiont. The Ycf2/FtsHi complex also contains an NAD-malate dehydrogenase, a proposed key enzyme for ATP production in chloroplasts in darkness or in nonphotosynthetic plastids. These findings advance our understanding of this ATP-driven protein translocation system that is unique to the green lineage of photosynthetic eukaryotes.}, }
@article {pmid30294317, year = {2018}, author = {Bellec, L and Cambon-Bonavita, MA and Cueff-Gauchard, V and Durand, L and Gayet, N and Zeppilli, D}, title = {A Nematode of the Mid-Atlantic Ridge Hydrothermal Vents Harbors a Possible Symbiotic Relationship.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {2246}, pmid = {30294317}, issn = {1664-302X}, abstract = {Deep-sea hydrothermal vent meiofauna have been the focus of recent research and the discovery of an abundant well-adapted free-living marine nematode on the Mid-Atlantic Ridge offers new perspectives on adaptations to the vent environment. Indeed, knowledge concerning biological interactions of microbes and meiofauna in marine extreme environments is scarce, especially for nematodes. In this study, we used microscopic observations [fluorescence in situ hybridization (FISH) and scanning electron microscopy (SEM)] and metabarcoding of 16S rRNA to characterize the bacterial community of the nematode species Oncholaimus dyvae, an overlooked but ecologically important vent organism. Detection of bacteria in the buccal cavity and on the cuticle (SEM) and epibionts in its intestine (FISH) suggests that O. dyvae harbors its own bacterial community. Molecular results and phylogenetic analysis show that bacteria associated with this species are related to symbiotic lineages typical of hydrothermal vent fauna, such as sulfur-oxidizing bacteria related to Epsilonproteobacteria and Gammaproteobacteria. This multi-approach study suggests a potential symbiotic role of bacteria with its nematode host and opens new research perspectives on vent meiofauna.}, }
@article {pmid30291507, year = {2018}, author = {Day, PM and Theg, SM}, title = {Evolution of protein transport to the chloroplast envelope membranes.}, journal = {Photosynthesis research}, volume = {138}, number = {3}, pages = {315-326}, pmid = {30291507}, issn = {1573-5079}, mesh = {*Biological Evolution ; Chloroplasts/*metabolism ; Intracellular Membranes/*metabolism ; Models, Biological ; Protein Transport ; }, abstract = {Chloroplasts are descendants of an ancient endosymbiotic cyanobacterium that lived inside a eukaryotic cell. They inherited the prokaryotic double membrane envelope from cyanobacteria. This envelope contains prokaryotic protein sorting machineries including a Sec translocase and relatives of the central component of the bacterial outer membrane β-barrel assembly module. As the endosymbiont was integrated with the rest of the cell, the synthesis of most of its proteins shifted from the stroma to the host cytosol. This included nearly all the envelope proteins identified so far. Consequently, the overall biogenesis of the chloroplast envelope must be distinct from cyanobacteria. Envelope proteins initially approach their functional locations from the exterior rather than the interior. In many cases, they have been shown to use components of the general import pathway that also serves the stroma and thylakoids. If the ancient prokaryotic protein sorting machineries are still used for chloroplast envelope proteins, their activities must have been modified or combined with the general import pathway. In this review, we analyze the current knowledge pertaining to chloroplast envelope biogenesis and compare this to bacteria.}, }
@article {pmid30283652, year = {2017}, author = {Kageyama, D and Ohno, M and Sasaki, T and Yoshido, A and Konagaya, T and Jouraku, A and Kuwazaki, S and Kanamori, H and Katayose, Y and Narita, S and Miyata, M and Riegler, M and Sahara, K}, title = {Feminizing Wolbachia endosymbiont disrupts maternal sex chromosome inheritance in a butterfly species.}, journal = {Evolution letters}, volume = {1}, number = {5}, pages = {232-244}, pmid = {30283652}, issn = {2056-3744}, abstract = {Wolbachia is a maternally inherited ubiquitous endosymbiotic bacterium of arthropods that displays a diverse repertoire of host reproductive manipulations. For the first time, we demonstrate that Wolbachia manipulates sex chromosome inheritance in a sexually reproducing insect. Eurema mandarina butterfly females on Tanegashima Island, Japan, are infected with the wFem Wolbachia strain and produce all-female offspring, while antibiotic treatment results in male offspring. Fluorescence in situ hybridization (FISH) revealed that wFem-positive and wFem-negative females have Z0 and WZ sex chromosome sets, respectively, demonstrating the predicted absence of the W chromosome in wFem-infected lineages. Genomic quantitative polymerase chain reaction (qPCR) analysis showed that wFem-positive females lay only Z0 eggs that carry a paternal Z, whereas females from lineages that are naturally wFem-negative lay both WZ and ZZ eggs. In contrast, antibiotic treatment of adult wFem females resulted in the production of Z0 and ZZ eggs, suggesting that this Wolbachia strain can disrupt the maternal inheritance of Z chromosomes. Moreover, most male offspring produced by antibiotic-treated wFem females had a ZZ karyotype, implying reduced survival of Z0 individuals in the absence of feminizing effects of Wolbachia. Antibiotic treatment of wFem-infected larvae induced male-specific splicing of the doublesex (dsx) gene transcript, causing an intersex phenotype. Thus, the absence of the female-determining W chromosome in Z0 individuals is functionally compensated by Wolbachia-mediated conversion of sex determination. We discuss how Wolbachia may manipulate the host chromosome inheritance and that Wolbachia may have acquired this coordinated dual mode of reproductive manipulation first by the evolution of female-determining function and then cytoplasmically induced disruption of sex chromosome inheritance.}, }
@article {pmid30279438, year = {2018}, author = {Quintanilla, E and Ramírez-Portilla, C and Adu-Oppong, B and Walljasper, G and Glaeser, SP and Wilke, T and Muñoz, AR and Sánchez, JA}, title = {Local confinement of disease-related microbiome facilitates recovery of gorgonian sea fans from necrotic-patch disease.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {14636}, pmid = {30279438}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/*microbiology ; Bacteria/*classification/*genetics ; Microbiota/*genetics ; Pacific Ocean ; Phylogeny ; RNA, Bacterial ; RNA, Ribosomal, 16S ; Symbiosis ; }, abstract = {Microbiome disruptions triggering disease outbreaks are increasingly threatening corals worldwide. In the Tropical Eastern Pacific, a necrotic-patch disease affecting gorgonian corals (sea fans, Pacifigorgia spp.) has been observed in recent years. However, the composition of the microbiome and its disease-related disruptions remain unknown in these gorgonian corals. Therefore, we analysed 16S rRNA gene amplicons from tissues of healthy colonies (n = 19) and from symptomatic-asymptomatic tissues of diseased colonies (n = 19) of Pacifigorgia cairnsi (Gorgoniidae: Octocorallia) in order to test for disease-related changes in the bacterial microbiome. We found that potential endosymbionts (mostly Endozoicomonas spp.) dominate the core microbiome in healthy colonies. Moreover, healthy tissues differed in community composition and functional profile from those of the symptomatic tissues but did not show differences to asymptomatic tissues of the diseased colonies. A more diverse set of bacteria was observed in symptomatic tissues, together with the decline in abundance of the potential endosymbionts from the healthy core microbiome. Furthermore, according to a comparative taxonomy-based functional profiling, these symptomatic tissues were characterized by the increase in heterotrophic, ammonia oxidizer and dehalogenating bacteria and by the depletion of nitrite and sulphate reducers. Overall, our results suggest that the bacterial microbiome associated with the disease behaves opportunistically and is likely in a state of microbial dysbiosis. We also conclude that the confinement of the disease-related consortium to symptomatic tissues may facilitate colony recovery.}, }
@article {pmid30279399, year = {2018}, author = {Montes-Rodríguez, IM and Rodríguez-Pou, Y and González-Méndez, RR and Lopez-Garriga, J and Ropelewski, AJ and Cadilla, CL}, title = {Characterization of Histone Genes from the Bivalve Lucina Pectinata.}, journal = {International journal of environmental research and public health}, volume = {15}, number = {10}, pages = {}, pmid = {30279399}, issn = {1660-4601}, support = {U54 MD007600/MD/NIMHD NIH HHS/United States ; T36 GM095335/GM/NIGMS NIH HHS/United States ; P20 GM103475/GM/NIGMS NIH HHS/United States ; T36 GM008789/GM/NIGMS NIH HHS/United States ; U54 MD007587/MD/NIMHD NIH HHS/United States ; G12 MD007600/MD/NIMHD NIH HHS/United States ; P20 RR016470/RR/NCRR NIH HHS/United States ; R25 GM088023/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Bivalvia/*genetics ; Conserved Sequence ; *Evolution, Molecular ; Exons ; Extreme Environments ; Histones/*genetics ; Phylogeny ; Puerto Rico ; RNA, Messenger/genetics ; Sequence Analysis, DNA ; Wetlands ; }, abstract = {Lucina pectinata is a clam that lives in sulfide-rich environments and houses intracellular sulfide-oxidizing endosymbionts. To identify new Lucina pectinata proteins, we produced libraries for genome and transcriptome sequencing and assembled them de novo. We searched for histone-like sequences using the Lucina pectinata histone H3 partial nucleotide sequence against our previously described genome assembly to obtain the complete coding region and identify H3 coding sequences from mollusk sequences in Genbank. Solen marginatus histone nucleotide sequences were used as query sequences using the genome and transcriptome assemblies to identify the Lucina pectinata H1, H2A, H2B and H4 genes and mRNAs and obtained the complete coding regions of the five histone genes by RT-PCR combined with automated Sanger DNA sequencing. The amino acid sequence conservation between the Lucina pectinata and Solen marginatus histones was: 77%, 93%, 83%, 96% and 97% for H1, H2A, H2B, H3 and H4, respectively. As expected, the H3 and H4 proteins were the most conserved and the H1 proteins were most similar to H1's from aquatic organisms like Crassostrea gigas, Aplysia californica, Mytilus trossulus and Biomphalaria glabrata. The Lucina pectinata draft genome and transcriptome assemblies, obtained by semiconductor sequencing, were adequate for identification of conserved proteins as evidenced by our results for the histone genes.}, }
@article {pmid30277756, year = {2018}, author = {Farfan, GA and Apprill, A and Webb, SM and Hansel, CM}, title = {Coupled X-ray Fluorescence and X-ray Absorption Spectroscopy for Microscale Imaging and Identification of Sulfur Species within Tissues and Skeletons of Scleractinian Corals.}, journal = {Analytical chemistry}, volume = {90}, number = {21}, pages = {12559-12566}, doi = {10.1021/acs.analchem.8b02638}, pmid = {30277756}, issn = {1520-6882}, mesh = {Animals ; Anthozoa/*chemistry ; Chondroitin Sulfates/analysis ; Cysteine/*analysis ; Glutathione Disulfide/*analysis ; Spectrometry, X-Ray Emission ; Sulfates/*analysis ; X-Ray Absorption Spectroscopy ; }, abstract = {Identifying and mapping the wide range of sulfur species within complex matrices presents a challenge for understanding the distribution of these important biomolecules within environmental and biological systems. Here, we present a coupled micro X-ray fluorescence (μXRF) and X-ray absorption near-edge structure (XANES) spectroscopy method for determining the presence of specific sulfur species in coral tissues and skeletons at high spatial resolution. By using multiple energy stacks and principal component analysis of a large spectral database, we were able to more accurately identify sulfur species components and distinguish different species and distributions of sulfur formerly unresolved by previous studies. Specifically, coral tissues were dominated by more reduced sulfur species, such as glutathione disulfide, cysteine, and sulfoxide, as well as organic sulfate as represented by chondroitin sulfate. Sulfoxide distributions were visually correlated with the presence of zooxanthellae endosymbionts. Coral skeletons were composed primarily of carbonate-associated sulfate (CAS) along with minor contributions from organic sulfate and a separate inorganic sulfate likely in the form of adsorbed sulfate. This coupled XRF-XANES approach allows for a more accurate and informative view of sulfur within biological systems in situ and holds great promise for pairing with other techniques to allow for a more encompassing understanding of elemental distributions within the environment.}, }
@article {pmid30275487, year = {2018}, author = {de Moraes, LA and Muller, C and Bueno, RCOF and Santos, A and Bello, VH and De Marchi, BR and Watanabe, LFM and Marubayashi, JM and Santos, BR and Yuki, VA and Takada, HM and de Barros, DR and Neves, CG and da Silva, FN and Gonçalves, MJ and Ghanim, M and Boykin, L and Pavan, MA and Krause-Sakate, R}, title = {Distribution and phylogenetics of whiteflies and their endosymbiont relationships after the Mediterranean species invasion in Brazil.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {14589}, pmid = {30275487}, issn = {2045-2322}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification ; Animals ; Brazil ; Electron Transport Complex IV/genetics ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification ; Genetic Variation ; Hemiptera/*classification/genetics/*growth &amp; development/microbiology ; *Introduced Species ; *Phylogeography ; *Symbiosis ; }, abstract = {The Bemisia tabaci is a polyphagous insect and a successful vector of plant viruses. B. tabaci is a species complex and in Brazil native species from the New World (NW) group, as well as the invasive species, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) were reported. For better understanding the distribution of the different species four years after the Mediterranean species invasion in Brazil, whiteflies were collected from 237 locations throughout the country between the years of 2013 and 2017, species were identified and the facultative endosymbionts detected. The survey revealed that MEAM1 was the prevalent species found on major crops across Brazil. It is the only species present in North, Northwestern and Central Brazil and was associated with virus-infected plants. MED was found in five States from Southeast to South regions, infesting mainly ornamental plants and was not associated with virus-infected plants. The prevalent endosymbionts identified in MEAM1 were Hamiltonella and Rickettsia; and the mtCOI analysis revealed low genetic diversity for MEAM1. In contrast, several different endosymbionts were identified in MED including Hamiltonella, Rickettsia, Wolbachia and Arsenophonus; and two distinct genetic groups were found based on the mtCOI analysis. Monitoring the distribution of the whiteflies species in Brazil is essential for proper management of this pest.}, }
@article {pmid30273387, year = {2018}, author = {Ruocco, N and Mutalipassi, M and Pollio, A and Costantini, S and Costantini, M and Zupo, V}, title = {First evidence of Halomicronema metazoicum (Cyanobacteria) free-living on Posidonia oceanica leaves.}, journal = {PloS one}, volume = {13}, number = {10}, pages = {e0204954}, pmid = {30273387}, issn = {1932-6203}, mesh = {Alismatales/*microbiology ; Base Sequence ; Cyanobacteria/classification/genetics/*isolation &amp; purification ; Plant Leaves/microbiology ; RNA, Ribosomal, 16S/chemistry/isolation &amp; purification/metabolism ; Seawater/microbiology ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Cyanobacteria contribute to the ecology of various marine environments, also for their symbioses, since some of them are common hosts of sponges and ascidians. They are also emerging as an important source of novel bioactive secondary metabolites in pharmacological (as anticancer drugs) and biotechnological applications. In the present work we isolated a cyanobacteria in a free-living state from leaves of the seagrass Posidonia oceanica leaves. This newly collected strain was then cultivated under two laboratory conditions, and then characterized by combining morphological observation and molecular studies based on 16S rRNA gene sequences analysis. The strain showed 99% pairwise sequence identity with Halomicronema metazoicum ITAC101, never isolated before as a free-living organisms, but firstly described as an endosymbiont of the Mediterranean marine spongae Petrosia ficiformis, under the form of a filamentous strain. Further studies will investigate the actual role of this cyanobacterium in the leaf stratum of P. oceanica leaves, given its demonstrated ability to influence the vitality and the life cycle of other organisms. In fact, its newly demonstrated free-living stage, described in this study, indicate that Phormidium-like cyanobacteria could play important roles in the ecology of benthic and planktonic communities.}, }
@article {pmid30271976, year = {2018}, author = {Liu, H and Stephens, TG and González-Pech, RA and Beltran, VH and Lapeyre, B and Bongaerts, P and Cooke, I and Aranda, M and Bourne, DG and Forêt, S and Miller, DJ and van Oppen, MJH and Voolstra, CR and Ragan, MA and Chan, CX}, title = {Symbiodinium genomes reveal adaptive evolution of functions related to coral-dinoflagellate symbiosis.}, journal = {Communications biology}, volume = {1}, number = {}, pages = {95}, pmid = {30271976}, issn = {2399-3642}, abstract = {Symbiosis between dinoflagellates of the genus Symbiodinium and reef-building corals forms the trophic foundation of the world's coral reef ecosystems. Here we present the first draft genome of Symbiodinium goreaui (Clade C, type C1: 1.03 Gbp), one of the most ubiquitous endosymbionts associated with corals, and an improved draft genome of Symbiodinium kawagutii (Clade F, strain CS-156: 1.05 Gbp) to further elucidate genomic signatures of this symbiosis. Comparative analysis of four available Symbiodinium genomes against other dinoflagellate genomes led to the identification of 2460 nuclear gene families (containing 5% of Symbiodinium genes) that show evidence of positive selection, including genes involved in photosynthesis, transmembrane ion transport, synthesis and modification of amino acids and glycoproteins, and stress response. Further, we identify extensive sets of genes for meiosis and response to light stress. These draft genomes provide a foundational resource for advancing our understanding of Symbiodinium biology and the coral-algal symbiosis.}, }
@article {pmid30266174, year = {2018}, author = {Wintermantel, WM}, title = {Integration of Omics Approaches toward Understanding Whitefly Transmission of Viruses.}, journal = {Advances in virus research}, volume = {102}, number = {}, pages = {199-223}, doi = {10.1016/bs.aivir.2018.06.005}, pmid = {30266174}, issn = {1557-8399}, mesh = {Animals ; Bacteria/growth &amp; development/metabolism ; Begomovirus/genetics/metabolism ; Biological Coevolution ; Crinivirus/genetics/metabolism ; Gene Expression Regulation ; Hemiptera/*virology ; Host-Pathogen Interactions/*genetics ; Insect Control/methods ; Insect Proteins/classification/*genetics/metabolism ; Insect Vectors/*virology ; Metabolomics/*methods ; Plant Diseases/virology ; Plants/*virology ; Symbiosis/genetics ; Transcriptome ; }, abstract = {Viruses transmitted by whiteflies are predominantly classified as having either persistent circulative or semipersistent transmission, and the majority of studies have addressed transmission of viruses in the genera Begomovirus (family Geminiviridae) and Crinivirus (family Closteroviridae), respectively. Early studies on vector transmission primarily addressed individual aspects of transmission; however, with the breadth of new technology now available, an increasingly greater number of studies involve coordinated research that is beginning to assemble a more complete picture of how whiteflies and viruses have coevolved to facilitate transmission. In particular the integration of gene expression and metabolomic studies into broader research topics is providing knowledge of changes within the whitefly vector in response to the presence of viruses that would have been impossible to identify previously. Examples include comparative studies on the response of Bemisia tabaci to begomovirus and crinivirus infection of common host plants, evolution of whitefly endosymbiont relationships, and opportunities to evaluate responses to specific transmission-related events. Integration of metabolomics, as well as the application of electrical penetration graphing, can lead to an ability to monitor the changes that occur in vector insects associated with specific aspects of virus transmission. Through gaining more complete knowledge of the mechanisms behind whitefly transmission of viruses new control strategies will undoubtedly emerge for control of whiteflies and the viruses they transmit.}, }
@article {pmid30261054, year = {2018}, author = {Carpinone, EM and Li, Z and Mills, MK and Foltz, C and Brannon, ER and Carlow, CKS and Starai, VJ}, title = {Identification of putative effectors of the Type IV secretion system from the Wolbachia endosymbiont of Brugia malayi.}, journal = {PloS one}, volume = {13}, number = {9}, pages = {e0204736}, pmid = {30261054}, issn = {1932-6203}, support = {R01 AI100913/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Bacterial Proteins/biosynthesis/genetics ; Brugia malayi/*microbiology ; Gene Expression Regulation, Bacterial/*physiology ; Saccharomyces cerevisiae/genetics/metabolism ; *Symbiosis ; *Type IV Secretion Systems/genetics/metabolism ; *Wolbachia/genetics/metabolism ; }, abstract = {Wolbachia is an unculturable, intracellular bacterium that persists within an extremely broad range of arthropod and parasitic nematode hosts, where it is transmitted maternally to offspring via vertical transmission. In the filarial nematode Brugia malayi, a causative agent of human lymphatic filariasis, Wolbachia is an endosymbiont, and its presence is essential for proper nematode development, survival, and pathogenesis. While the elucidation of Wolbachia:nematode interactions that promote the bacterium's intracellular persistence is of great importance, research has been hampered due to the fact that Wolbachia cannot be cultured in the absence of host cells. The Wolbachia endosymbiont of B. malayi (wBm) has an active Type IV secretion system (T4SS). Here, we have screened 47 putative T4SS effector proteins of wBm for their ability to modulate growth or the cell biology of a typical eukaryotic cell, Saccharomyces cerevisiae. Five candidates strongly inhibited yeast growth upon expression, and 6 additional proteins showed toxicity in the presence of zinc and caffeine. Studies on the uptake of an endocytic vacuole-specific fluorescent marker, FM4-64, identified 4 proteins (wBm0076 wBm00114, wBm0447 and wBm0152) involved in vacuole membrane dynamics. The WAS(p)-family protein, wBm0076, was found to colocalize with yeast cortical actin patches and disrupted actin cytoskeleton dynamics upon expression. Deletion of the Arp2/3-activating protein, Abp1p, provided resistance to wBm0076 expression, suggesting a role for wBm0076 in regulating eukaryotic actin dynamics and cortical actin patch formation. Furthermore, wBm0152 was found to strongly disrupt endosome:vacuole cargo trafficking in yeast. This study provides molecular insight into the potential role of the T4SS in the Wolbachia endosymbiont:nematode relationship.}, }
@article {pmid30254612, year = {2018}, author = {Schmidt, C and Morard, R and Romero, O and Kucera, M}, title = {Diverse Internal Symbiont Community in the Endosymbiotic Foraminifera Pararotalia calcariformata: Implications for Symbiont Shuffling Under Thermal Stress.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {2018}, pmid = {30254612}, issn = {1664-302X}, abstract = {Many shallow-water tropical and subtropical foraminifera engage in photosymbiosis with eukaryotic microalgae. Some of these foraminifera appear to harbor a diverse consortium of endosymbiotic algae within a single host. Such apparent ability to contain different symbionts could facilitate change in symbiont community composition (symbiont shuffling) and mediate the ecological success of the group in a changing environment. However, the discovery of the intra-individual symbiont diversity was thus far based on symbiont culturing, which provides strong constraints on the vitality of the identified algae but provides poor constraints on their initial abundance and thus functional relevance to the host. Here we analyze the algal symbiont diversity in Pararotalia calcariformata, a benthic foraminifera sampled at four stations, inside and outside of a thermal plume in the eastern Mediterranean coast of Israel. This species has recently invaded the Mediterranean, is unusually thermally tolerant and was described previously to host at least one different diatom symbiont than other symbiont-bearing foraminifera. Our results using genotyping and isolation of algae in culture medium, confirm multiple associations with different diatom species within the same individual. Both methods revealed spatially consistent symbiont associations and identified the most common symbiont as a pelagic diatom Minutocellus polymorphus. In one case, an alternative dominant symbiont, the diatom Navicula sp., was detected by genotyping. This diatom was the third most abundant species identified using standard algae culturing method. This method further revealed a spatially consistent pattern in symbiont diversity of a total of seventeen identified diatom species, across the studied localities. Collectively, these results indicate that P. calcariformata hosts a diverse consortium of diatom endosymbionts, where different members can become numerically dominant and thus functionally relevant in a changing environment.}, }
@article {pmid30247558, year = {2018}, author = {Mix, AK and Cenci, U and Heimerl, T and Marter, P and Wirkner, ML and Moog, D}, title = {Identification and Localization of Peroxisomal Biogenesis Proteins Indicates the Presence of Peroxisomes in the Cryptophyte Guillardia theta and Other "Chromalveolates".}, journal = {Genome biology and evolution}, volume = {10}, number = {10}, pages = {2834-2852}, pmid = {30247558}, issn = {1759-6653}, mesh = {Amino Acid Sequence ; Conserved Sequence ; Cryptophyta/genetics/*metabolism ; *Organelle Biogenesis ; Peroxins/genetics/*metabolism ; Peroxisomes/*metabolism ; Phylogeny ; Protein Domains ; }, abstract = {Peroxisomes are single-membrane-bound organelles with a huge metabolic versatility, including the degradation of fatty acids (β-oxidation) and the detoxification of reactive oxygen species as most conserved functions. Although peroxisomes seem to be present in the majority of investigated eukaryotes, where they are responsible for many eclectic and important spatially separated metabolic reactions, knowledge about their existence in the plethora of protists (eukaryotic microorganisms) is scarce. Here, we investigated genomic data of organisms containing complex plastids with red algal ancestry (so-called "chromalveolates") for the presence of genes encoding peroxins-factors specific for the biogenesis, maintenance, and division of peroxisomes in eukaryotic cells. Our focus was on the cryptophyte Guillardia theta, a marine microalga, which possesses two phylogenetically different nuclei of host and endosymbiont origin, respectively, thus being of enormous evolutionary significance. Besides the identification of a complete set of peroxins in G. theta, we heterologously localized selected factors as GFP fusion proteins via confocal and electron microscopy in the model diatom Phaeodactylum tricornutum. Furthermore, we show that peroxins, and thus most likely peroxisomes, are present in haptophytes as well as eustigmatophytes, brown algae, and alveolates including dinoflagellates, chromerids, and noncoccidian apicomplexans. Our results indicate that diatoms are not the only "chromalveolate" group devoid of the PTS2 receptor Pex7, and thus a PTS2-dependent peroxisomal import pathway, which seems to be absent in haptophytes (Emiliania huxleyi) as well. Moreover, important aspects of peroxisomal biosynthesis and protein import in "chromalveolates"are highlighted.}, }
@article {pmid30244151, year = {2019}, author = {Schön, I and Kamiya, T and Van den Berghe, T and Van den Broecke, L and Martens, K}, title = {Novel Cardinium strains in non-marine ostracod (Crustacea) hosts from natural populations.}, journal = {Molecular phylogenetics and evolution}, volume = {130}, number = {}, pages = {406-415}, doi = {10.1016/j.ympev.2018.09.008}, pmid = {30244151}, issn = {1095-9513}, mesh = {Animals ; Aquatic Organisms/*microbiology ; Bacteroidetes/genetics/*physiology ; Base Sequence ; Crustacea/genetics/*microbiology ; Diptera/genetics ; Electron Transport Complex IV/genetics ; Genetic Variation ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; }, abstract = {Endosymbiotic bacteria are known from many metazoan taxa, where they manipulate host biology and reproduction. Here, we used classic PCR amplification and direct DNA sequencing with universal primers for four different endosymbionts to test for their presence in more than 300 specimens of three recent non-marine ostracod superfamilies from different geographic areas and aquatic habitats. We verified these results with "high throughput" amplicon sequencing of 16S of nine selected specimens and evolutionary placement algorithms. The phylogenetic position of endosymbionts detected in ostracod hosts was compared to known endosymbionts from other metazoans. While Wolbachia, Spiroplasma and Rickettsia are absent, we find evidence for the general presence of Cardinium bacteria in natural populations of various non-marine ostracod species. Phylogenetic reconstructions based on Cardinium 16S data and estimates of genetic distances both indicate that Cardinium from ostracods are distantly related to Cardinium from Diptera and Nematoda but represent novel strains with a monophyletic origin. Cardinium bacteria from different ostracod hosts have genetic distances of up to 3.8%, providing evidence against recent and frequent horizontal transmissions amongst the three ostracod superfamilies. High throughput sequencing reveals more than 400 different 16S amplicon sequence variants in the investigated ostracods as well as the presence of different Cardinium strains within individual Eucypris virens and Heterocypris hosts. These results call for future, more in-depth investigations. Mapping Cardinium infections on COI trees of non-marine ostracod hosts shows that the occurrence of these endosymbionts is not linked to genetic species identity or phylogenetic host groups and, except for one ostracod morphospecies, prevalence never reaches 100%.}, }
@article {pmid30243102, year = {2018}, author = {Jacobson, AL and Duffy, S and Sseruwagi, P}, title = {Whitefly-transmitted viruses threatening cassava production in Africa.}, journal = {Current opinion in virology}, volume = {33}, number = {}, pages = {167-176}, doi = {10.1016/j.coviro.2018.08.016}, pmid = {30243102}, issn = {1879-6265}, mesh = {Africa ; Animals ; Begomovirus/*growth &amp; development/isolation &amp; purification ; Developing Countries ; Hemiptera/*virology ; Insect Vectors/*virology ; Manihot/*growth &amp; development ; Plant Diseases/*virology ; Potyviridae/*growth &amp; development/isolation &amp; purification ; }, abstract = {Emerging plant viruses are one of the greatest problems facing crop production worldwide, and have severe consequences in the developing world where subsistence farming is a major source of food production, and knowledge and resources for management are limited. In Africa, evolution of two viral disease complexes, cassava mosaic begomoviruses (CMBs) (Geminiviridae) and cassava brown streak viruses (CBSVs) (Potyviridae), have resulted in severe pandemics that continue to spread and threaten cassava production. Identification of genetically diverse and rapidly evolving CMBs and CBSVs, extensive genetic variation in the vector, Bemisia tabaci (Hemiptera: Aleyrodidae), and numerous secondary endosymbiont profiles that influence vector phenotypes suggest that complex local and regional vector-virus-plant-environment interactions may be driving the evolution and epidemiology of these viruses.}, }
@article {pmid30231855, year = {2018}, author = {Zeng, Z and Fu, Y and Guo, D and Wu, Y and Ajayi, OE and Wu, Q}, title = {Bacterial endosymbiont Cardinium cSfur genome sequence provides insights for understanding the symbiotic relationship in Sogatella furcifera host.}, journal = {BMC genomics}, volume = {19}, number = {1}, pages = {688}, pmid = {30231855}, issn = {1471-2164}, mesh = {Animals ; Bacterial Proteins/*genetics ; Cytophagaceae/*physiology ; *Genome, Bacterial ; Genomics ; Hemiptera/*genetics/growth &amp; development/*microbiology ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {BACKGROUND: Sogatella furcifera is a migratory pest that damages rice plants and causes severe economic losses. Due to its ability to annually migrate long distances, S. furcifera has emerged as a major pest of rice in several Asian countries. Symbiotic relationships of inherited bacteria with terrestrial arthropods have significant implications. The genus Cardinium is present in many types of arthropods, where it influences some host characteristics. We present a report of a newly identified strain of the bacterial endosymbiont Cardinium cSfur in S. furcifera.<br><br>RESULT: From the whole genome of S. furcifera previously sequenced by our laboratory, we assembled the whole genome sequence of Cardinium cSfur. The sequence comprised 1,103,593&#xa0;bp with a GC content of 39.2%. The phylogenetic tree of the Bacteroides phylum to which Cardinium cSfur belongs suggests that Cardinium cSfur is closely related to the other strains (Cardinium cBtQ1 and cEper1) that are members of the Amoebophilaceae family. Genome comparison between the host-dependent endosymbiont including Cardinium cSfur and free-living bacteria revealed that the endosymbiont has a smaller genome size and lower GC content, and has lost some genes related to metabolism because of its special environment, which is similar to the genome pattern observed in other insect symbionts. Cardinium cSfur has limited metabolic capability, which makes it less contributive to metabolic and biosynthetic processes in its host. From our findings, we inferred that, to compensate for its limited metabolic capability, Cardinium cSfur harbors a relatively high proportion of transport proteins, which might act as the hub between it and its host. With its acquisition of the whole operon related to biotin synthesis and glycolysis related genes through HGT event, Cardinium cSfur seems to be undergoing changes while establishing a symbiotic relationship with its host.<br><br>CONCLUSION: A novel bacterial endosymbiont strain (Cardinium cSfur) has been discovered. A genomic analysis of the endosymbiont in S. furcifera suggests that its genome has undergone certain changes to facilitate its settlement in the host. The envisaged potential reproduction manipulative ability of the new endosymbiont strain in its S. furcifera host has vital implications in designing eco-friendly approaches to combat the insect pest.}, }
@article {pmid30223906, year = {2018}, author = {Bredon, M and Dittmer, J and Noël, C and Moumen, B and Bouchon, D}, title = {Lignocellulose degradation at the holobiont level: teamwork in a keystone soil invertebrate.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {162}, pmid = {30223906}, issn = {2049-2618}, mesh = {Animals ; Bacteria/enzymology/genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Bacterial Proteins/genetics/metabolism ; Gastrointestinal Microbiome ; Isopoda/*metabolism/*microbiology/physiology ; Lignin/*metabolism ; Phylogeny ; Soil/parasitology ; *Symbiosis ; }, abstract = {BACKGROUND: Woodlice are recognized as keystone species in terrestrial ecosystems due to their role in the decomposition of organic matter. Thus, they contribute to lignocellulose degradation and nutrient cycling in the environment together with other macroarthropods. Lignocellulose is the main component of plants and is composed of cellulose, lignin and hemicellulose. Its digestion requires the action of multiple Carbohydrate-Active enZymes (called CAZymes), typically acting together as a cocktail with complementary, synergistic activities and modes of action. Some invertebrates express a few endogenous lignocellulose-degrading enzymes but in most species, an efficient degradation and digestion of lignocellulose can only be achieved through mutualistic associations with endosymbionts. Similar to termites, it has been suspected that several bacterial symbionts may be involved in lignocellulose degradation in terrestrial isopods, by completing the CAZyme repertoire of their hosts.<br><br>RESULTS: To test this hypothesis, host transcriptomic and microbiome shotgun metagenomic datasets were obtained and investigated from the pill bug Armadillidium vulgare. Many genes of bacterial and archaeal origin coding for CAZymes were identified in the metagenomes of several host tissues and the gut content of specimens from both laboratory lineages and a natural population of A. vulgare. Some of them may be involved in the degradation of cellulose, hemicellulose, and lignin. Reconstructing a lignocellulose-degrading microbial community based on the prokaryotic taxa contributing relevant CAZymes revealed two taxonomically distinct but functionally redundant microbial communities depending on host origin. In parallel, endogenous CAZymes were identified from the transcriptome of the host and their expression in digestive tissues was demonstrated by RT-qPCR, demonstrating a complementary enzyme repertoire for lignocellulose degradation from both the host and the microbiome in A. vulgare.<br><br>CONCLUSIONS: Our results provide new insights into the role of the microbiome in the evolution of terrestrial isopods and their adaptive radiation in terrestrial habitats.}, }
@article {pmid30219893, year = {2018}, author = {Zélé, F and Santos, JL and Godinho, DP and Magalhães, S}, title = {Wolbachia both aids and hampers the performance of spider mites on different host plants.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {12}, pages = {}, doi = {10.1093/femsec/fiy187}, pmid = {30219893}, issn = {1574-6941}, mesh = {Animals ; Bacteroidetes/metabolism ; Fabaceae/microbiology/parasitology ; Female ; Host Specificity ; Ipomoea nil/*microbiology/*parasitology ; Lycopersicon esculentum/*microbiology/*parasitology ; Rickettsia/metabolism ; Solanum melongena/*microbiology/*parasitology ; Symbiosis/physiology ; Tetranychidae/metabolism/*microbiology ; Wolbachia/*metabolism ; }, abstract = {In the last few decades, many studies have revealed the potential role of arthropod bacterial endosymbionts in shaping the host range of generalist herbivores and their performance on different host plants, which, in turn, might affect endosymbiont distribution in herbivore populations. We tested this by measuring the prevalence of endosymbionts in natural populations of the generalist spider mite Tetranychus urticae on different host plants. Focusing on Wolbachia, we then analysed how symbionts affected mite life-history traits on the same host plants in the laboratory. Overall, the prevalences of Cardinium and Rickettsia were low, whereas that of Wolbachia was high, with the highest values on bean and eggplant and the lowest on morning glory, tomato and zuchini. Although most mite life-history traits were affected by the plant species only, Wolbachia infection was detrimental for the egg-hatching rate on morning glory and zucchini, and led to a more female-biased sex ratio on morning glory and eggplant. These results suggest that endosymbionts may affect the host range of polyphagous herbivores, both by aiding and hampering their performance, depending on the host plant and on the life-history trait that affects performance the most. Conversely, endosymbiont spread may be facilitated or hindered by the plants on which infected herbivores occur.}, }
@article {pmid30209475, year = {2018}, author = {Niehs, SP and Scherlach, K and Hertweck, C}, title = {Genomics-driven discovery of a linear lipopeptide promoting host colonization by endofungal bacteria.}, journal = {Organic &amp; biomolecular chemistry}, volume = {16}, number = {37}, pages = {8345-8352}, doi = {10.1039/c8ob01515e}, pmid = {30209475}, issn = {1477-0539}, mesh = {Burkholderia/*genetics/*physiology ; Conserved Sequence ; *Genomics ; Lipopeptides/*metabolism ; Multigene Family/genetics ; Rhizopus/*physiology ; *Symbiosis ; }, abstract = {The rice seedling blight fungus Rhizopus microsporus weakens or kills plants by means of a potent toxin produced by endobacteria (Burkholderia rhizoxinica) that live within the fungal hyphae. The success of the highly attuned microbial interaction is partly based on the bacteria's ability to roam and re-colonize the fungal host. Yet, apart from the toxin, chemical mediators of the symbiosis have remained elusive. By genome mining and comparison we identified a cryptic NRPS gene cluster that is conserved among all sequenced Rhizopus endosymbionts. Metabolic profiling and targeted gene inactivation led to the discovery of a novel linear lipopeptide, holrhizin A, which was fully characterized. Through in vitro and in vivo assays we found that holrhizin acts (A) as a biosurfactant to reduce surface tension, (B) influences the formation of mature biofilms and thus cell motility behavior that ultimately supports the bacterial cells to (C) colonize and invade the fungal host, consequently supporting the re-establishment of the exceptional Burkholderia-Rhizopus symbiosis. We not only unveil structure and function of an linear lipopeptide from endofungal bacteria but also provide a functional link between the symbiont's orphan NRPS genes and a chemical mediator that promotes bacterial invasion into the fungal host.}, }
@article {pmid30208057, year = {2018}, author = {Humphreys, AF and Halfar, J and Ingle, JC and Manzello, D and Reymond, CE and Westphal, H and Riegl, B}, title = {Effect of seawater temperature, pH, and nutrients on the distribution and character of low abundance shallow water benthic foraminifera in the Galápagos.}, journal = {PloS one}, volume = {13}, number = {9}, pages = {e0202746}, pmid = {30208057}, issn = {1932-6203}, mesh = {Chlorophyll A/analysis ; Cluster Analysis ; Coral Reefs ; Ecuador ; El Nino-Southern Oscillation ; Foraminifera/*growth &amp; development ; Geologic Sediments/chemistry ; Hydrogen-Ion Concentration ; Models, Statistical ; Nutrients/*chemistry ; Seawater/*chemistry ; Temperature ; }, abstract = {In order to help predict the effects of anthropogenic stressors on shallow water carbonate environments, it is important to focus research on regions containing natural oceanographic gradients, particularly with respect to interactions between oceanography and ecologically sensitive carbonate producers. The Galápagos Archipelago, an island chain in the eastern equatorial Pacific, spans a natural nutrient, pH, and temperature gradient due to the interaction of several major ocean currents. Further, the region is heavily impacted by the El Niño-Southern Oscillation (ENSO) and the Galápagos exhibited widespread coral bleaching and degradation following the strong ENSO events of 1982-1983 and 1997-1998. These findings are coupled with reports of unusually low abundances of time-averaged benthic foraminiferal assemblages throughout the region. Foraminifera, shelled single-celled protists, are sensitive to environmental change and rapidly respond to alterations to their surrounding environment, making them ideal indicator species for the study of reef water quality and health. Here, statistical models and analyses were used to compare modern shallow water benthic foraminiferal assemblages from 19 samples spanning the Galápagos Archipelago to predominant oceanographic parameters at each collection site. Fisher α diversity indices, Ternary diagrams, Canonical Correspondence Analysis, regression tree analysis and FORAM-Index (FI; a single metric index for evaluating water quality associated with reef development) implied a combined impact from ENSO and upwelling from Equatorial Undercurrent (EUC) waters to primarily impact foraminiferal abundances and drive assemblage patterns throughout the archipelago. For instance, repeated ENSO temperature anomalies might be responsible for low foraminiferal density, while chronically high nutrients and low aragonite saturation and low pH-induced by EUC upwelling and La Niña anomalies-likely inhibited post-ENSO recovery, and caused foraminiferal assemblages to exhibit a heterotrophic dominance in the southern archipelago. What resulted are low FI values in the southern collection sites, indicating environments not conducive to endosymbiont development and/or recovery.}, }
@article {pmid30202647, year = {2018}, author = {Pascar, J and Chandler, CH}, title = {A bioinformatics approach to identifying Wolbachia infections in arthropods.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5486}, pmid = {30202647}, issn = {2167-8359}, abstract = {Wolbachia is the most widespread endosymbiont, infecting >20% of arthropod species, and capable of drastically manipulating the host's reproductive mechanisms. Conventionally, diagnosis has relied on PCR amplification; however, PCR is not always a reliable diagnostic technique due to primer specificity, strain diversity, degree of infection and/or tissue sampled. Here, we look for evidence of Wolbachia infection across a wide array of arthropod species using a bioinformatic approach to detect the Wolbachia genes ftsZ, wsp, and the groE operon in next-generation sequencing samples available through the NCBI Sequence Read Archive. For samples showing signs of infection, we attempted to assemble entire Wolbachia genomes, and in order to better understand the relationships between hosts and symbionts, phylogenies were constructed using the assembled gene sequences. Out of the 34 species with positively identified infections, eight species of arthropod had not previously been recorded to harbor Wolbachia infection. All putative infections cluster with known representative strains belonging to supergroup A or B, which are known to only infect arthropods. This study presents an efficient bioinformatic approach for post-sequencing diagnosis and analysis of Wolbachia infection in arthropods.}, }
@article {pmid30201781, year = {2018}, author = {Compton, KK and Hildreth, SB and Helm, RF and Scharf, BE}, title = {Sinorhizobium meliloti Chemoreceptor McpV Senses Short-Chain Carboxylates via Direct Binding.}, journal = {Journal of bacteriology}, volume = {200}, number = {23}, pages = {}, pmid = {30201781}, issn = {1098-5530}, mesh = {Amino Acids/metabolism ; Bacterial Proteins/genetics/*metabolism ; Calcium Channels ; Calorimetry ; Carboxylic Acids/*metabolism ; Chemotactic Factors/*metabolism ; *Chemotaxis ; Fluorometry ; Ligands ; Medicago sativa/*microbiology ; Models, Molecular ; Periplasm/metabolism ; Plant Exudates ; Protein Domains ; Sinorhizobium meliloti/genetics/*physiology ; Symbiosis ; }, abstract = {Sinorhizobium meliloti is a soil-dwelling endosymbiont of alfalfa that has eight chemoreceptors to sense environmental stimuli during its free-living state. The functions of two receptors have been characterized, with McpU and McpX serving as general amino acid and quaternary ammonium compound sensors, respectively. Both receptors use a dual Cache (calcium channels and chemotaxis receptors) domain for ligand binding. We identified that the ligand-binding periplasmic region (PR) of McpV contains a single Cache domain. Homology modeling revealed that McpV[PR] is structurally similar to a sensor domain of a chemoreceptor with unknown function from Anaeromyxobacter dehalogenans, which crystallized with acetate in its binding pocket. We therefore assayed McpV for carboxylate binding and S. meliloti for carboxylate sensing. Differential scanning fluorimetry identified 10 potential ligands for McpV[PR] Nine of these are monocarboxylates with chain lengths between two and four carbons. We selected seven compounds for capillary assay analysis, which established positive chemotaxis of the S. meliloti wild type, with concentrations of peak attraction at 1 mM for acetate, propionate, pyruvate, and glycolate, and at 100 mM for formate and acetoacetate. Deletion of mcpV or mutation of residues essential for ligand coordination abolished positive chemotaxis to carboxylates. Using microcalorimetry, we determined that dissociation constants of the seven ligands with McpV[PR] were in the micromolar range. An McpV[PR] variant with a mutation in the ligand coordination site displayed no binding to isobutyrate or propionate. Of all the carboxylates tested as attractants, only glycolate was detected in alfalfa seed exudates. This work examines the relevance of carboxylates and their sensor to the rhizobium-legume interaction.IMPORTANCE Legumes share a unique association with certain soil-dwelling bacteria known broadly as rhizobia. Through concerted interorganismal communication, a legume allows intracellular infection by its cognate rhizobial species. The plant then forms an organ, the root nodule, dedicated to housing and supplying fixed carbon and nutrients to the bacteria. In return, the engulfed rhizobia, differentiated into bacteroids, fix atmospheric N2 into ammonium for the plant host. This interplay is of great benefit to the cultivation of legumes, such as alfalfa and soybeans, and is initiated by chemotaxis to the host plant. This study on carboxylate chemotaxis contributes to the understanding of rhizobial survival and competition in the rhizosphere and aids the development of commercial inoculants.}, }
@article {pmid30197044, year = {2018}, author = {Lin, Z and Wang, L and Chen, M and Chen, J}, title = {The acute transcriptomic response of coral-algae interactions to pH fluctuation.}, journal = {Marine genomics}, volume = {42}, number = {}, pages = {32-40}, doi = {10.1016/j.margen.2018.08.006}, pmid = {30197044}, issn = {1876-7478}, mesh = {Animals ; Anthozoa/genetics/*physiology ; China ; Dinoflagellida/genetics/*physiology ; Hydrogen-Ion Concentration ; *Symbiosis ; *Transcriptome ; }, abstract = {Little is known about how the coral host and its endosymbiont interactions change when they are exposed to a sudden nonlinear environmental transformation, yet this is crucial to coral survival in extreme events. Here, we present a study that investigates the transcriptomic response of corals and their endosymbionts to an abrupt change in pH (pH 7.60 and 8.35). The transcriptome indicates that the endosymbiont demonstrates a synchronized downregulation in carbon acquisition and fixation processes and may result in photosynthetic dysfunction in endosymbiotic Symbiodinium, suggesting that the mutualistic continuum of coral-algae interactions is compromised in response to high-CO2 exposure. Transcriptomic data also shows that corals are still capable of calcifying in response to the low pH but could experience a series of negative effects on their energy dynamics, which including protein damage, DNA repair, ion transport, cellular apoptosis, calcification acclimation and maintenance of intracellular pH homeostasis and stress tolerance to pH swing. This suggests enhanced energy costs for coral metabolic adaptation. This study provides a deeper understanding of the biological basis related to the symbiotic corals in response to extreme future climate change and environmental variability.}, }
@article {pmid30194350, year = {2018}, author = {Alleman, A and Hertweck, KL and Kambhampati, S}, title = {Random Genetic Drift and Selective Pressures Shaping the Blattabacterium Genome.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {13427}, pmid = {30194350}, issn = {2045-2322}, mesh = {Animals ; Cockroaches/microbiology ; *Evolution, Molecular ; Flavobacteriaceae/*genetics ; *Genetic Drift ; *Genome, Bacterial ; Symbiosis ; }, abstract = {Estimates suggest that at least half of all extant insect genera harbor obligate bacterial mutualists. Whereas an endosymbiotic relationship imparts many benefits upon host and symbiont alike, the intracellular lifestyle has profound effects on the bacterial genome. The obligate endosymbiont genome is a product of opposing forces: genes important to host survival are maintained through physiological constraint, contrasted by the fixation of deleterious mutations and genome erosion through random genetic drift. The obligate cockroach endosymbiont, Blattabacterium - providing nutritional augmentation to its host in the form of amino acid synthesis - displays radical genome alterations when compared to its most recent free-living relative Flavobacterium. To date, eight Blattabacterium genomes have been published, affording an unparalleled opportunity to examine the direction and magnitude of selective forces acting upon this group of symbionts. Here, we find that the Blattabacterium genome is experiencing a 10-fold increase in selection rate compared to Flavobacteria. Additionally, the proportion of selection events is largely negative in direction, with only a handful of loci exhibiting signatures of positive selection. These findings suggest that the Blattabacterium genome will continue to erode, potentially resulting in an endosymbiont with an even further reduced genome, as seen in other insect groups such as Hemiptera.}, }
@article {pmid30190541, year = {2018}, author = {Chung, M and Teigen, L and Liu, H and Libro, S and Shetty, A and Kumar, N and Zhao, X and Bromley, RE and Tallon, LJ and Sadzewicz, L and Fraser, CM and Rasko, DA and Filler, SG and Foster, JM and Michalski, ML and Bruno, VM and Dunning Hotopp, JC}, title = {Targeted enrichment outperforms other enrichment techniques and enables more multi-species RNA-Seq analyses.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {13377}, pmid = {30190541}, issn = {2045-2322}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Aspergillus fumigatus/*genetics ; Brugia malayi/*genetics ; *RNA, Bacterial/chemistry/genetics/isolation &amp; purification ; *RNA, Fungal/chemistry/genetics/isolation &amp; purification ; *RNA, Helminth/chemistry/genetics/isolation &amp; purification ; *RNA, Messenger/chemistry/genetics/isolation &amp; purification ; Sequence Analysis, RNA/*methods ; Wolbachia/*genetics ; }, abstract = {Enrichment methodologies enable the analysis of minor members in multi-species transcriptomic data. We compared the standard enrichment of bacterial and eukaryotic mRNA to a targeted enrichment using an Agilent SureSelect (AgSS) capture for Brugia malayi, Aspergillus fumigatus, and the Wolbachia endosymbiont of B. malayi (wBm). Without introducing significant systematic bias, the AgSS quantitatively enriched samples, resulting in more reads mapping to the target organism. The AgSS-enriched libraries consistently had a positive linear correlation with their unenriched counterparts (r[2] = 0.559-0.867). Up to a 2,242-fold enrichment of RNA from the target organism was obtained following a power law (r[2] = 0.90), with the greatest fold enrichment achieved in samples with the largest ratio difference between the major and minor members. While using a single total library for prokaryote and eukaryote enrichment from a single RNA sample could be beneficial for samples where RNA is limiting, we observed a decrease in reads mapping to protein coding genes and an increase in multi-mapping reads to rRNAs in AgSS enrichments from eukaryotic total RNA libraries compared to eukaryotic poly(A)-enriched libraries. Our results support a recommendation of using AgSS targeted enrichment on poly(A)-enriched libraries for eukaryotic captures, and total RNA libraries for prokaryotic captures, to increase the robustness of multi-species transcriptomic studies.}, }
@article {pmid30186690, year = {2018}, author = {Tang, XT and Cai, L and Shen, Y and Du, YZ}, title = {Diversity and evolution of the endosymbionts of Bemisia tabaci in China.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5516}, pmid = {30186690}, issn = {2167-8359}, abstract = {The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex, including members that are pests of global importance. This study presents a screening of B. tabaci species in China for infection by the primary endosymbiont, Portiera aleyrodidarum, and two secondary endosymbionts, Arsenophonus and Cardinium. The results showed that P. aleyrodidarum was detected in all B. tabaci individuals, while Arsenophonus was abundant in indigenous species of B. tabaci Asia II 1, Asia II 3, and China 1 but absent in the invasive species, Middle East-Asia Minor 1 (MEAM1); Cardinium presented in the Mediterranean (MED), Asia II 1 and Asia II 3 species but was rarely detected in the MEAM1 and China 1 species. Moreover, phylogenetic analyses revealed that the P. aleyrodidarum and mitochondrial cytochrome oxidase 1 (mtCO1) phylograms were similar and corresponding with the five distinct cryptic species clades to some extent, probably indicating an ancient infection followed by vertical transmission and subsequent co-evolutionary diversification. In contrast, the phylogenetic trees of Arsenophonus and Cardinium were incongruent with the mtCO1 phylogram, potentially indicating horizontal transmission in B. tabaci cryptic species complex. Taken together, our study showed the distinct infection status of endosymbionts in invasive and indigenous whiteflies; we also most likely indicated the co-evolution of primary endosymbiont and its host as well as the potential horizontal transfer of secondary endosymbionts.}, }
@article {pmid30186672, year = {2018}, author = {Ross, BJ and Hallock, P}, title = {Challenges in using CellTracker Green on foraminifers that host algal endosymbionts.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5304}, pmid = {30186672}, issn = {2167-8359}, abstract = {The uses of fluorescent microscopy and fluorescent probes, such as the metabolically activated probe CellTracker™ Green CMFDA (CTG), have become common in studies of living Foraminifera. This metabolic requirement, as well as the relatively quick production of the fluorescent reaction products, makes CTG a prime candidate for determining mortality in bioassay and other laboratory experiments. Previous work with the foraminifer Amphistegina gibbosa, which hosts diatom endosymbionts, has shown that the species is capable of surviving both acute chemical exposure and extended periods of total darkness by entering a low-activity dormant state. This paper explores the use of CTG and fluorescent microscopy to determine mortality in such experiments, as well as to explore the physiology of dormant foraminifers. The application of CTG was found to be complicated by the autofluorescence of the diatom symbionts, which masks the signal of the CTG, as well as by interactions between CTG and propylene glycol, a chemical of interest known to cause dormancy. These complications necessitated adapting methods from earlier studies using CTG. Here we present observations on CTG fluorescence and autofluorescence in A. gibbosa following both chemical exposure and periods of total darkness. While CTG can indicate vital activity in dormant foraminifers, complications include underestimates of total survival and recovery, and falsely indicating dead individuals as live due to rapid microbial colonization. Nonetheless, the brightness of the CTG signal in dormant individuals exposed to propylene glycol supports previously published results of survival patterns in A. gibbosa. Observations of CTG fluorescence in individuals kept for extended periods in aphotic conditions indicate uptake of CTG may begin within 30 min of exposure to light, suggesting darkness-induced dormancy and subsequent recovery can occur on short time scales. These results suggest that CTG accurately reflects changes associated with dormancy, and can be useful in laboratory experiments utilizing symbiont-bearing foraminifers.}, }
@article {pmid30172712, year = {2018}, author = {Lai, JH and Luo, SF and Ho, LJ}, title = {Operation of mitochondrial machinery in viral infection-induced immune responses.}, journal = {Biochemical pharmacology}, volume = {156}, number = {}, pages = {348-356}, pmid = {30172712}, issn = {1873-2968}, mesh = {Animals ; Antiviral Agents/*pharmacology ; Humans ; Immunity, Innate/*physiology ; Mitochondria/*immunology ; Mitochondrial Dynamics ; Virus Diseases/drug therapy/*immunology ; }, abstract = {Mitochondria have been recognized as ancient bacteria that contain evolutionary endosymbionts. Metabolic pathways and inflammatory signals interact within mitochondria in response to different stresses, such as viral infections. In this commentary, we address several interesting questions, including (1) how do mitochondrial machineries participate in immune responses; (2) how do mitochondria mediate antiviral immunity; (3) what mechanisms involved in mitochondrial machinery, including the downregulation of mitochondrial DNA (mtDNA), disturbances of mitochondrial dynamics, and the induction of mitophagy and regulation of apoptosis, have been adopted by viruses to evade antiviral immunity; (4) what mechanisms involve the regulation of mitochondrial machineries in antiviral therapeutics; and (5) what are the potential challenges and perspectives in developing mitochondria-targeting antiviral treatments? This commentary provides a comprehensive review of the roles and mechanisms of mitochondrial machineries in immunity, viral infections and related antiviral therapeutics.}, }
@article {pmid30165658, year = {2018}, author = {Cevidanes, A and Di Cataldo, S and Vera, F and Lillo, P and Millán, J}, title = {Molecular Detection of Vector-Borne Pathogens in Rural Dogs and Associated Ctenocephalides felis Fleas (Siphonaptera: Pulicidae) in Easter Island (Chile).}, journal = {Journal of medical entomology}, volume = {55}, number = {6}, pages = {1659-1663}, doi = {10.1093/jme/tjy141}, pmid = {30165658}, issn = {1938-2928}, mesh = {Animals ; Ctenocephalides/*microbiology ; Dogs/*parasitology ; Female ; Insect Vectors/*microbiology ; Male ; Polynesia ; }, abstract = {The presence of vector-borne pathogens of veterinary and public health interest have received little attention in Chile. In Easter Island, in particular, a Chilean territory in the southeastern Pacific Ocean, no information is available. To fill this gap, 153 rural dogs were inspected for ectoparasites during a sterilization campaign carried out in 2016. Fleas were observed in 46% of the dogs, and Ctenocephalides felis (Bouché, 1835) was the only species present. Morphological identification of fleas was genetically confirmed using conventional polymerase chain reaction targeting the cox2 gene. No tick was observed in any dog. The presence of DNA of Rickettsia sp. (gltA and ompA fragment genes), Anaplasmataceae (16S rRNA), and Bartonella sp. (16S-23S ribosomal RNA intergenic spacer) was investigated in blood samples of 70 of the dogs and in 126 fleas analyzed in 68 pools that included 1-5 fleas. Rickettsial DNA was detected in 97% (n = 66) of the flea pools. Of these, 57 showed between 99 and 100% identity for both genes with published sequences of Candidatus Rickettsia asemboensis (CRa), six with Rickettsia felis, and one with Candidatus Rickettsia senegalensis. For two pools, gltA amplicons were identical to CRa but ompB amplicions showed 99-100% identity with R. felis. Anaplasmataceae DNA was detected in 16% (n = 11) pools. Sequenced amplicons showed highest identity with the endosymbiont Wolbachia pipientis. Bartonella DNA, showing 99% identity to Bartonella clarridgeiae, was detected in one pool (1.4%). No positive reaction was observed for any dog. This is the first detection of members of the 'R. felis-like' group other than R. felis in Chile.}, }
@article {pmid30160099, year = {2018}, author = {Dose, B and Niehs, SP and Scherlach, K and Flórez, LV and Kaltenpoth, M and Hertweck, C}, title = {Unexpected Bacterial Origin of the Antibiotic Icosalide: Two-Tailed Depsipeptide Assembly in Multifarious Burkholderia Symbionts.}, journal = {ACS chemical biology}, volume = {13}, number = {9}, pages = {2414-2420}, doi = {10.1021/acschembio.8b00600}, pmid = {30160099}, issn = {1554-8937}, mesh = {Animals ; Anti-Bacterial Agents/*metabolism ; Burkholderia/enzymology/genetics/*physiology ; Coleoptera/*microbiology ; Genes, Bacterial ; Peptide Synthases/genetics/metabolism ; Peptides, Cyclic/genetics/*metabolism ; *Symbiosis ; }, abstract = {Icosalide is an unusual two-tailed lipocyclopeptide antibiotic that was originally isolated from a fungal culture. Yet, its biosynthesis and ecological function have remained enigmatic. By genome mining and metabolic profiling of a bacterial endosymbiont (Burkholderia gladioli) of the pest beetle Lagria villosa, we unveiled a bacterial origin of icosalide. Functional analysis of the biosynthetic gene locus revealed an unprecedented nonribosomal peptide synthetase (NRPS) that incorporates two β-hydroxy acids by means of two starter condensation domains in different modules. This unusual assembly line, which may inspire new synthetic biology approaches, is widespread among many symbiotic Burkholderia species from diverse habitats. Biological assays showed that icosalide is active against entomopathogenic bacteria, thus adding to the chemical armory protecting beetle offspring. By creating a null mutant, we found that icosalide is a swarming inhibitor, which may play a role in symbiotic interactions and bears the potential for therapeutic applications.}, }
@article {pmid30154059, year = {2019}, author = {Cafiso, A and Sassera, D and Romeo, C and Serra, V and Hervet, C and Bandi, C and Plantard, O and Bazzocchi, C}, title = {Midichloria mitochondrii, endosymbiont of Ixodes ricinus: evidence for the transmission to the vertebrate host during the tick blood meal.}, journal = {Ticks and tick-borne diseases}, volume = {10}, number = {1}, pages = {5-12}, doi = {10.1016/j.ttbdis.2018.08.008}, pmid = {30154059}, issn = {1877-9603}, mesh = {Animals ; Antibodies, Bacterial/*blood ; Bacterial Infections/microbiology/*transmission ; Bacterial Proteins/*blood ; DNA, Bacterial/*blood ; Disease Models, Animal ; Female ; Ixodes/growth &amp; development/*microbiology/*physiology ; Kinetics ; Male ; Nymph/growth &amp; development/microbiology/physiology ; Rabbits ; Rickettsiales/*physiology ; Symbiosis ; }, abstract = {Ticks are important vectors of a variety of pathogens affecting humans and other animals, but they also harbor numerous microorganisms whose role is still limitedly investigated. Ixodes ricinus harbors the endosymbiont Midichloria mitochondrii, which is localized in ovaries and in salivary glands. The bacterium is vertically transmitted and is present in 100% of wild adult females, while prevalence values drop after some generations under laboratory conditions. Molecular and serological evidences showed that M. mitochondrii molecules are transmitted to the vertebrate hosts by I. ricinus during the blood meal. Our work was focused on monitoring M. mitochondrii antigens and DNA in a vertebrate model after infestation with I. ricinus for a time-span of four months. Two groups of rabbits were infested with I. ricinus females, respectively from the wild (naturally infected with the symbiont) and laboratory strain (lab; considered devoid of M. mitochondrii after quantitative PCR investigations) and screened using molecular and serological assays at nine time points. M. mitochondrii presence was detected in rabbits infested with wild I. ricinus ticks, but surprisingly also in those infested with lab ticks, albeit at later time points. This result prompted a more sensitive molecular screening of lab ticks, which were found to harbor very low symbiont loads. Our results indicate that transmission of the bacterium occurs even at low bacterial loads, and that antibody response against M. mitochondrii antigens begins within one week post-infestation with wild I. ricinus. Circulating DNA was detected in the blood of rabbits belonging to both groups up to the end of the experiment, suggesting a replication of the symbiont inside the vertebrate host.}, }
@article {pmid30149795, year = {2018}, author = {Brown, AMV}, title = {Endosymbionts of Plant-Parasitic Nematodes.}, journal = {Annual review of phytopathology}, volume = {56}, number = {}, pages = {225-242}, doi = {10.1146/annurev-phyto-080417-045824}, pmid = {30149795}, issn = {1545-2107}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Host-Parasite Interactions ; Nematoda/*microbiology ; Plant Diseases/parasitology/*prevention &amp; control ; Plants/*parasitology ; *Symbiosis ; }, abstract = {Some of the most agriculturally important plant-parasitic nematodes (PPNs) harbor endosymbionts. Extensive work in other systems has shown that endosymbionts can have major effects on host virulence and biology. This review highlights the discovery, development, and diversity of PPN endosymbionts, incorporating inferences from genomic data. Cardinium, reported from five PPN hosts to date, is characterized by its presence in the esophageal glands and other tissues, with a discontinuous distribution across populations, and genomic data suggestive of horizontal gene exchange. Xiphinematobacter occurs in at least 27 species of dagger nematode in the ovaries and gut epithelial cells, where genomic data suggest it may serve in nutritional supplementation. Wolbachia, reported in just three PPNs, appears to have an ancient history in the Pratylenchidae and displays broad tissue distribution and genomic features intermediate between parasitic and reproductive groups. Finally, a model is described that integrates these insights to explain patterns of endosymbiont replacement.}, }
@article {pmid30149793, year = {2018}, author = {Pawlowska, TE and Gaspar, ML and Lastovetsky, OA and Mondo, SJ and Real-Ramirez, I and Shakya, E and Bonfante, P}, title = {Biology of Fungi and Their Bacterial Endosymbionts.}, journal = {Annual review of phytopathology}, volume = {56}, number = {}, pages = {289-309}, doi = {10.1146/annurev-phyto-080417-045914}, pmid = {30149793}, issn = {1545-2107}, mesh = {*Bacterial Physiological Phenomena/genetics ; Evolution, Molecular ; Fungi/genetics/*physiology ; *Symbiosis/genetics ; }, abstract = {Heritable symbioses, in which endosymbiotic bacteria (EB) are transmitted vertically between host generations, are an important source of evolutionary novelties. A primary example of such symbioses is the eukaryotic cell with its EB-derived organelles. Recent discoveries suggest that endosymbiosis-related innovations can be also found in associations formed by early divergent fungi in the phylum Mucoromycota with heritable EB from two classes, Betaproteobacteria and Mollicutes. These symbioses exemplify novel types of host-symbiont interactions. Studies of these partnerships fuel theoretical models describing mechanisms that stabilize heritable symbioses, control the rate of molecular evolution, and enable the establishment of mutualisms. Lastly, by altering host phenotypes and metabolism, these associations represent an important instrument for probing the basic biology of the Mucoromycota hosts, which remain one of the least explored filamentous fungi.}, }
@article {pmid30148833, year = {2018}, author = {Cerutti, F and Modesto, P and Rizzo, F and Cravero, A and Jurman, I and Costa, S and Giammarino, M and Mandola, ML and Goria, M and Radovic, S and Cattonaro, F and Acutis, PL and Peletto, S}, title = {The microbiota of hematophagous ectoparasites collected from migratory birds.}, journal = {PloS one}, volume = {13}, number = {8}, pages = {e0202270}, pmid = {30148833}, issn = {1932-6203}, mesh = {Animal Migration ; Animals ; Arthropods/*microbiology ; Bacteria/*isolation &amp; purification ; Bird Diseases/*parasitology ; Birds/parasitology ; Computational Biology ; Ectoparasitic Infestations/parasitology/*veterinary ; Italy ; *Microbiota ; Molecular Typing ; Parasites/*microbiology ; RNA, Ribosomal, 16S ; Ticks/microbiology ; }, abstract = {Arthropod vectors are responsible for the transmission of human pathogens worldwide. Several arthropod species are bird ectoparasites, however, no study to date has characterized their microbiota as a whole. We sampled hematophagous ectoparasites that feed on migratory birds and performed 16S rRNA gene metabarcoding to characterize their microbial community. A total of 194 ectoparasites were collected from 115 avian hosts and classified into three groups: a) Hippoboscidae diptera; b) ticks; c) other arthropods. Metabarcoding showed that endosymbionts were the most abundant genera of the microbial community, including Wolbachia for Hippoboscidae diptera, Candidatus Midichloria for ticks, Wolbachia and Arsenophonus for the other arthropod group. Genera including pathogenic species were: Rickettsia, Borrelia, Coxiella, Francisella, Bartonella, Anaplasma. Co-infection with Borrelia-Rickettsia and Anaplasma-Rickettsia was also observed. A global overview of the microbiota of ectoparasites sampled from migratory birds was obtained with the use of 16S rRNA gene metabarcoding. A novel finding is the first identification of Rickettsia in the common swift louse fly, Crataerina pallida. Given their possible interaction with pathogenic viruses and bacteria, the presence of endosymbionts in arthropods merits attention. Finally, molecular characterization of genera, including both pathogenic and symbiont species, plays a pivotal role in the design of targeted molecular diagnostics.}, }
@article {pmid30147222, year = {2018}, author = {Takagi, H and Kimoto, K and Fujiki, T and Moriya, K}, title = {Effect of nutritional condition on photosymbiotic consortium of cultured Globigerinoides sacculifer (Rhizaria, Foraminifera).}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {76}, number = {1}, pages = {25-39}, pmid = {30147222}, issn = {0334-5114}, abstract = {Several foraminifers found in warm and low-nutrient ocean surface water have photosynthetic algae as endosymbionts (photosymbiosis). To understand the trophic interactions, we studied Globigerinoides sacculifer, a spinose planktic foraminifer that has a dinoflagellate endosymbiont. We controlled two nutritional factors, feeding and inorganic nutrients in the seawater. The growth of the host and the symbionts and the photophysiological parameters were monitored under four experimental conditions. The results demonstrated that the holobionts primarily relied on phagotrophy for growth. The foraminifers grew considerably, and the chlorophyll a content per foraminifer, which is an indicator of the symbiont population, increased in the fed groups, but not in the unfed groups. The nutrient-rich seawater used for some of the cultures made no difference in either the growth or photophysiology of the holobionts. These observations indicated that the symbionts mainly utilized metabolites from the hosts for photosynthesis rather than inorganic nutrients in the seawater. Additionally, we observed that the symbionts in the starved hosts maintained their photosynthetic capability for at least 12 days, and that the hosts maintained at least some symbionts until gametogenesis was achieved. This suggests that the hosts have to retain the symbionts as an energy source for reproduction. The symbionts may also play an indispensable role in the metabolic activities of the hosts including waste transport or essential compound synthesis. Overall, our results revealed a novel mode of photosymbiosis in planktic foraminifers which contrasts with that found in benthic photosymbiotic foraminifers and corals.}, }
@article {pmid30139962, year = {2019}, author = {Richardson, KM and Griffin, PC and Lee, SF and Ross, PA and Endersby-Harshman, NM and Schiffer, M and Hoffmann, AA}, title = {A Wolbachia infection from Drosophila that causes cytoplasmic incompatibility despite low prevalence and densities in males.}, journal = {Heredity}, volume = {122}, number = {4}, pages = {428-440}, pmid = {30139962}, issn = {1365-2540}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Biological Evolution ; Cytoplasm/*microbiology ; Drosophila/*genetics/*microbiology ; Female ; Fertility/genetics ; Male ; Phylogeny ; Reproduction ; Symbiosis/genetics ; Wolbachia/classification/genetics/*physiology ; }, abstract = {Wolbachia bacteria are common insect endosymbionts transmitted maternally and capable of spreading through insect populations by cytoplasmic incompatibility (CI) when infected males cause embryo death after mating with uninfected females. Selection in the Wolbachia endosymbiont occurs on female hosts and is expected to favour strong maternal transmission to female offspring, even at the cost of reduced CI. With maternal leakage, nuclear genes are expected to be selected to suppress cytoplasmic incompatibility caused by males while also reducing any deleterious effects associated with the infection. Here we describe a new type of Wolbachia strain from Drosophila pseudotakahashii likely to have arisen from evolutionary processes on host and/or Wolbachia genomes. This strain is often absent from adult male offspring, but always transmitted to females. It leads to males with low or non-detectable Wolbachia that nevertheless show CI. When detected in adult males, the infection has a low density relative to that in females, a phenomenon not previously seen in Wolbachia infections of Drosophila. This Wolbachia strain is common in natural populations, and shows reduced CI when older (infected) males are crossed. These patterns highlight that endosymbionts can have strong sex-specific effects and that high frequency Wolbachia strains persist through effects on female reproduction. Female-limited Wolbachia infections may be of applied interest if the low level of Wolbachia in males reduces deleterious fitness effects on the host.}, }
@article {pmid30137308, year = {2018}, author = {Shi, PQ and Wang, L and Liu, Y and An, X and Chen, XS and Ahmed, MZ and Qiu, BL and Sang, W}, title = {Infection dynamics of endosymbionts reveal three novel localization patterns of Rickettsia during the development of whitefly Bemisia tabaci.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {11}, pages = {}, doi = {10.1093/femsec/fiy165}, pmid = {30137308}, issn = {1574-6941}, mesh = {Animals ; Enterobacteriaceae/isolation &amp; purification ; Female ; Halomonadaceae/isolation &amp; purification ; Hemiptera/growth &amp; development/*microbiology ; In Situ Hybridization, Fluorescence ; Rickettsia/isolation &amp; purification ; *Symbiosis ; }, abstract = {The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a severe agricultural pest that harbors at least seven endosymbionts. Many important aspects of the symbiosis mechanism between these bacterial endosymbionts and their hosts are poorly understood, such as endosymbiont proliferation dynamics, spatial distribution and titer regulation during host development. In this study, infection by bacterial endosymbionts in the whitefly B. tabaci Middle East-Asia Minor-1 (MEAM1, formerly B biotype) South China population, their infection titers in various stages of whitefly host development and their spatial localization were investigated. Results revealed that the MEAM1 B. tabaci harbors the primary symbiont Portiera and secondary symbionts Rickettsia and Hamiltonella. The titers of these three endosymbionts increased with the development of their B. tabaci host. Significant proliferation of Portiera and Hamiltonella mainly occurred during the second to fourth instar nymphal stages, while Rickettsia proliferated mainly during adult eclosion. Fluorescence in situ hybridization analysis of B. tabaci adults revealed three novel infection patterns of Rickettsia: assemblage in the bacteriocytes that scattered through the entire abdomen of the female host, localization in wax glands and localization in the colleterial gland. These novel infection patterns may help to uncover the function of Rickettsia in its insect hosts.}, }
@article {pmid30128208, year = {2018}, author = {Van Duyl, FC and Mueller, B and Meesters, EH}, title = {Spatio-temporal variation in stable isotope signatures (δ[13]C and δ[15]N) of sponges on the Saba Bank.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5460}, pmid = {30128208}, issn = {2167-8359}, abstract = {Sponges are ubiquitous on coral reefs, mostly long lived and therefore adaptive to changing environmental conditions. They feed on organic matter withdrawn from the passing water and they may harbor microorganisms (endosymbionts), which contribute to their nutrition. Their diets and stable isotope (SI) fractionation determine the SI signature of the sponge holobiont. Little is known of spatio-temporal variations in SI signatures of δ[13]C and δ[15]N in tropical sponges and whether they reflect variations in the environment. We investigated the SI signatures of seven common sponge species with different functional traits and their potential food sources between 15 and 32 m depth along the S-SE and E-NE side of the Saba Bank, Eastern Caribbean, in October 2011 and October 2013. SI signatures differed significantly between most sponge species, both in mean values and in variation, indicating different food preferences and/or fractionation, inferring sponge species-specific isotopic niche spaces. In 2011, all sponge species at the S-SE side were enriched in d[13]C compared to the E-NE side. In 2013, SI signatures of sponges did not differ between the two sides and were overall lighter in δ[13]C and δ[15]N than in 2011. Observed spatio-temporal changes in SI in sponges could not be attributed to changes in the SI signatures of their potential food sources, which remained stable with different SI signatures of pelagic (particulate organic matter (POM): δ[13]C -24.9‰, δ[15]N +4.3‰) and benthic-derived food (macroalgae: δ[13]C -15.4‰, δ[15]N +0.8‰). Enriched δ[13]C signatures in sponges at the S-SE side in 2011 are proposed to be attributed to predominantly feeding on benthic-derived C. This interpretation was supported by significant differences in water mass constituents between sides in October 2011. Elevated NO3 and dissolved organic matter concentrations point toward a stronger reef signal in reef overlying water at the S-SE than N-NE side of the Bank in 2011. The depletions of δ[13]C and δ[15]N in sponges in October 2013 compared to October 2011 concurred with significantly elevated POM concentrations. The contemporaneous decrease in δ[15]N suggests that sponges obtain their N mostly from benthic-derived food with a lower δ[15]N than pelagic food. Average proportional feeding on available sources varied between sponge species and ranged from 20% to 50% for benthic and 50% to 80% for pelagic-derived food, assuming trophic enrichment factors of 0.5‰ ± sd 0.5 for δ[13]C and 3‰ ± sd 0.5 for δ[15]N for sponges. We suggest that observed variation of SI in sponges between sides and years were the result of shifts in the proportion of ingested benthic- and pelagic-derived organic matter driven by environmental changes. We show that sponge SI signatures reflect environmental variability in space and time on the Saba Bank and that SI of sponges irrespective of their species-specific traits move in a similar direction in response to these environmental changes.}, }
@article {pmid30128189, year = {2018}, author = {Anderson, EE and Wilson, C and Knap, AH and Villareal, TA}, title = {Summer diatom blooms in the eastern North Pacific gyre investigated with a long-endurance autonomous surface vehicle.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5387}, pmid = {30128189}, issn = {2167-8359}, abstract = {Satellite chlorophyll a (chl a) observations have repeatedly noted summertime phytoplankton blooms in the North Pacific subtropical gyre (NPSG), a region of open ocean that is far removed from any land-derived or Ekman upwelling nutrient sources. These blooms are dominated by N2-fixing diatom-cyanobacteria associations of the diatom genera Rhizosolenia Brightwell and Hemiaulus Ehrenberg. Their nitrogen fixing endosymbiont, Richelia intracellularis J.A. Schmidt, is hypothesized to be critical to the development of blooms in this nitrogen limited region. However, due to the remote location and unpredictable duration of the summer blooms, prolonged in situ observations are rare outside of the Station ALOHA time-series off of Hawai'i. In summer, 2015, a proof-of-concept mission using the autonomous vehicle, Honey Badger (Wave Glider SV2; Liquid Robotics, a Boeing company, Sunnyvale, CA, USA), collected near-surface (<20 m) observations in the NPSG using hydrographic, meteorological, optical, and imaging sensors designed to focus on phytoplankton abundance, distribution, and physiology of this bloom-forming region. Hemiaulus and Rhizosolenia cell abundance was determined using digital holography for the entire June-November mission. Honey Badger was not able to reach the 30°N subtropical front region where most of the satellite chl a blooms have been observed, but near-real time navigational control allowed it to transect two blooms near 25°N. The two taxa did not co-occur in large numbers, rather the blooms were dominated by either Hemiaulus or Rhizosolenia. The August 2-4, 2015 bloom was comprised of 96% Hemiaulus and the second bloom, August 15-17, 2015, was dominated by Rhizosolenia (75%). The holograms also imaged undisturbed, fragile Hemiaulus aggregates throughout the sampled area at ∼10 L[-1]. Aggregated Hemiaulus represented the entire observed population at times and had a widespread distribution independent of the summer export pulse, a dominant annual event suggested to be mediated by aggregate fluxes. Aggregate occurrence was not consistent with a density dependent formation mechanism and may represent a natural growth form in undisturbed conditions. The photosynthetic potential index (Fv:Fm) increased from ∼0.4 to ∼0.6 during both blooms indicating a robust, active phytoplankton community in the blooms. The diel pattern of Fv:Fm (nocturnal maximum; diurnal minimum) was consistent with macronutrient limitation throughout the mission with no evidence of Fe-limitation despite the presence of nitrogen fixing diatom-diazotroph assemblages. During the 5-month mission, Honey Badger covered ∼5,690 km (3,070 nautical miles), acquired 9,336 holograms, and reliably transmitted data onshore in near real-time. Software issues developed with the active fluorescence sensor that terminated measurements in early September. Although images were still useful at the end of the mission, fouling of the LISST-Holo optics was considerable, and appeared to be the most significant issue facing deployments of this duration.}, }
@article {pmid30110980, year = {2018}, author = {Mallo, N and Fellows, J and Johnson, C and Sheiner, L}, title = {Protein Import into the Endosymbiotic Organelles of Apicomplexan Parasites.}, journal = {Genes}, volume = {9}, number = {8}, pages = {}, pmid = {30110980}, issn = {2073-4425}, support = {MC_PC_17190/MRC_/Medical Research Council/United Kingdom ; }, abstract = {: The organelles of endosymbiotic origin, plastids, and mitochondria, evolved through the serial acquisition of endosymbionts by a host cell. These events were accompanied by gene transfer from the symbionts to the host, resulting in most of the organellar proteins being encoded in the cell nuclear genome and trafficked into the organelle via a series of translocation complexes. Much of what is known about organelle protein translocation mechanisms is based on studies performed in common model organisms; e.g., yeast and humans or Arabidopsis. However, studies performed in divergent organisms are gradually accumulating. These studies provide insights into universally conserved traits, while discovering traits that are specific to organisms or clades. Apicomplexan parasites feature two organelles of endosymbiotic origin: a secondary plastid named the apicoplast and a mitochondrion. In the context of the diseases caused by apicomplexan parasites, the essential roles and divergent features of both organelles make them prime targets for drug discovery. This potential and the amenability of the apicomplexan Toxoplasma gondii to genetic manipulation motivated research about the mechanisms controlling both organelles' biogenesis. Here we provide an overview of what is known about apicomplexan organelle protein import. We focus on work done mainly in T. gondii and provide a comparison to model organisms.}, }
@article {pmid30107579, year = {2018}, author = {Flatau, R and Segoli, M and Khokhlova, I and Hawlena, H}, title = {Wolbachia's role in mediating its flea's reproductive success differs according to flea origin.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {10}, pages = {}, doi = {10.1093/femsec/fiy157}, pmid = {30107579}, issn = {1574-6941}, mesh = {Animals ; Host Specificity ; Models, Biological ; Reproduction ; Rodentia/parasitology ; Selection, Genetic ; Siphonaptera/growth &amp; development/*microbiology/*physiology ; Symbiosis ; Wolbachia/growth &amp; development/*physiology ; }, abstract = {Endosymbionts-microbes that live within and engage in prolonged and intimate associations with their hosts-are gaining recognition for their direct impact on plant and animal reproduction. Here we used the overlooked Wolbachia-flea system to explore the possibility that endosymbionts may also play a role as mediators in shaping the reproductive success of their hosts. We simultaneously quantified the Wolbachia density in field- and laboratory-originated fleas that fed and mated on rodents for either 5 or 10 days and assessed their body size and current reproductive success. By combining multigroup analysis and model selection approaches, we teased apart the contribution of the direct effects of the flea's physiological age and body size and the mediation effect of its Wolbachia endosymbionts on flea reproductive success, and we showed that the latter was stronger than the former. However, interestingly, the mediation effect was manifested only in laboratory-originated fleas, for which the increase in Wolbachia with age translated into lower reproductive success. These results suggest that some well-supported phenomena, such as aging effects, may be driven by endosymbionts and show once again that the role of endosymbionts in shaping the reproductive success of their host depends on their selective environment.}, }
@article {pmid30106668, year = {2018}, author = {Wang, Y and Mao, L and Sun, Y and Wang, Z and Zhang, J and Zhang, J and Peng, Y and Xia, L}, title = {A Novel Francisella-Like Endosymbiont in Haemaphysalis longicornis and Hyalomma asiaticum, China.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {18}, number = {12}, pages = {669-676}, doi = {10.1089/vbz.2017.2252}, pmid = {30106668}, issn = {1557-7759}, mesh = {Animal Distribution ; Animals ; China ; Francisella/*genetics/*isolation &amp; purification ; Ixodidae/*microbiology ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Francisella tularensis causes a highly infectious zoonotic disease tularemia. Both Haemaphysalis longicornis and Hyalomma asiaticum are widely distributed in China, but the presence of Francisella and Francisella-like endosymbionts (FLEs) in the two tick species is poorly understood. Therefore, a total of 627 H. longicornis (471 adults and 156 nymphs) and 88 Hy. asiaticum ticks (adults) were collected, of which 88 were from Bole of Xinjiang, 236 from Liaoyang, and 176 from Shenyang of Liaoning, and 215 from Wuhan of Hubei. Notably, five H. longicornis pools from Liaoyang of Liaoning province might have harbored F. tularensis, showing a minimum prevalence of 2.12% (5/236). This study should alert the health department and veterinarians working within the region to prevent and control the emergence of tularemia. After the screening of 16S rRNA and tul4 genes, the results revealed that FLEs were detected in Hy. asiaticum ticks in Bole and in H. longicornis ticks in Liaoyang and Shenyang. Their infection rate was 100% (88/88), 3.39% (8/236 is a minimum), and 8.52% (15/176), respectively. Phylogenetic analyses indicated that the sequence named bole in Hy. Asiaticum from Bole, the sequence named liaoyang1 in H. longicornis from Liaoyang, and the sequence named shanyang1 in H. longicornis from Shenyang shared consistent 16S rRNA sequence, and the difference between Chinese FLEs and the known FLEs was obvious. These findings suggest that this FLE species might be a potentially novel FLE circulating in H. longicornis and Hy. asiaticum from China.}, }
@article {pmid30106293, year = {2018}, author = {Kruse, A and Ramsey, JS and Johnson, R and Hall, DG and MacCoss, MJ and Heck, M}, title = {Candidatus Liberibacter asiaticus Minimally Alters Expression of Immunity and Metabolism Proteins in Hemolymph of Diaphorina citri, the Insect Vector of Huanglongbing.}, journal = {Journal of proteome research}, volume = {17}, number = {9}, pages = {2995-3011}, doi = {10.1021/acs.jproteome.8b00183}, pmid = {30106293}, issn = {1535-3907}, mesh = {Acetylation ; Animals ; Bacterial Proteins/classification/genetics/*metabolism ; Citrus/parasitology ; Energy Metabolism ; Fatty Acids ; Gene Ontology ; Hemiptera/genetics/immunology/*metabolism/microbiology ; Hemolymph/*chemistry/immunology/metabolism/microbiology ; Host-Pathogen Interactions/genetics/immunology ; Insect Proteins/classification/genetics/immunology/*metabolism ; Insect Vectors/genetics/immunology/metabolism/microbiology ; Lipid Metabolism ; Molecular Chaperones/genetics/metabolism ; Molecular Sequence Annotation ; Phosphorylation ; Plant Diseases/parasitology ; *Protein Processing, Post-Translational ; Proteome/classification/genetics/immunology/*metabolism ; Proteomics/methods ; Rhizobiaceae/genetics/*metabolism ; Symbiosis/genetics/immunology ; Vitellogenins ; Wolbachia/genetics/metabolism ; }, abstract = {Huanglongbing (HLB), also known as citrus greening disease, is the most serious disease of citrus plants. It is associated with the Gram-negative bacterium ' Candidatus Liberibacter asiaticus' (CLas), which is transmitted between host plants by the hemipteran insect vector Diaphorina citri in a circulative, propagative manner involving specific interactions with various insect tissues including the hemolymph, fluid that occupies the body cavity akin to insect blood. High resolution quantitative mass spectrometry was performed to investigate the effect of CLas exposure on D. citri hemolymph at the proteome level. In contrast to the broad proteome effects on hundreds of proteins and a diverse array of metabolic pathways previously reported in gut and whole insect proteome analyses, the effect of CLas on the hemolymph was observed to be highly specific, restricted to key immunity and metabolism pathways, and lower in magnitude than that previously observed in the whole insect body and gut. Vitellogenins were abundantly expressed and CLas-responsive. Gene-specific RNA expression analysis suggests that these proteins are expressed in both male and female insects and may have roles outside of reproductive vitellogenesis. Proteins for fatty acid synthesis were found to be up-regulated, along with metabolic proteins associated with energy production, supported at the organismal level by the previously published observation that D. citri individuals experience a higher level of hunger when reared on CLas-infected plants. Prediction of post-translational modifications identified hemolymph proteins with phosphorylation and acetylation upon CLas exposure. Proteins derived from the three most prominent bacterial endosymbionts of the psyllid were also detected in the hemolymph, and several of these have predicted secretion signals. A DNAK protein, the bacterial HSP70, detected in the hemolymph expressed from Wolbachia pipientis was predicted to encode a eukaryotic nuclear localization signal. Taken together, these data show specific changes to immunity and metabolism in D. citri hemolymph involving host and endosymbiont proteins. These data provide a novel context for proteomic changes seen in other D. citri tissues in response to CLas and align with organismal data on the effects of CLas on D. citri metabolism and reproduction.}, }
@article {pmid30105044, year = {2018}, author = {Schausberger, P}, title = {Herbivore-Associated Bacteria as Potential Mediators and Modifiers of Induced Plant Defense Against Spider Mites and Thrips.}, journal = {Frontiers in plant science}, volume = {9}, number = {}, pages = {1107}, pmid = {30105044}, issn = {1664-462X}, abstract = {Induced plant defense, comprising contact with exogenous stimuli, production of endogenous signals alerting the plant, associated biochemical cascades, and local and/or systemic expression of the defense mechanisms, critically depends on the nature of the inducing agents. At large, bio-trophic pathogenic microorganisms and viruses usually trigger the salicylate (SA)-mediated pathway, whereas necro-trophic pathogens and herbivores usually trigger the jasmonate (JA)-mediated pathway in plants. The SA- and JA-mediated pathways do not operate independently but commonly interfere with each other. Several recent studies revealed abnormal plant responses upon herbivore attack in diverse plant-herbivore systems. Observed abnormalities range from suppression of the common JA-pathway, induction of the SA-pathway to no response, yet the underlying proximate causes and ultimate consequences of these variations are elusive. Strikingly, some studies provide compelling evidence that anti-herbivore plant responses may decisively depend on bacteria associated with the herbivore attacking the plant (HAB for herbivore-associated bacteria). HAB may influence herbivore recognition by the plant and alter the biochemical cascades inside plants. Here, I report cases in point of HAB manipulating induced anti-herbivore plant responses, suggest spatial and temporal categorization of HAB, and point at proximate and ultimate aspects of plant defense manipulation by HAB. Following, I overview the diversity of HAB of spider mites and herbivorous thrips, argue that, considering recently reported phenomena of abnormal plant responses upon spider mite attack, some of these HAB could represent important, but hitherto largely neglected, mediators/modifiers of induced plant defense against spider mites and thrips, and conclude with suggestions for future research.}, }
@article {pmid30104608, year = {2018}, author = {Mukherjee, S and Joardar, N and Mondal, S and Schiefer, A and Hoerauf, A and Pfarr, K and Babu, SPS}, title = {Quinolone-fused cyclic sulfonamide as a novel benign antifilarial agent.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {12073}, pmid = {30104608}, issn = {2045-2322}, mesh = {Aedes ; Animals ; Apoptosis/drug effects ; Cattle ; Disease Models, Animal ; Elephantiasis, Filarial/*drug therapy/parasitology ; Female ; Filaricides/chemistry/*pharmacology/therapeutic use ; Humans ; Male ; Mice ; Oxidative Stress/drug effects ; Parasitic Sensitivity Tests ; Quinolones/chemistry/*pharmacology/therapeutic use ; RAW 264.7 Cells ; Rats ; Reactive Oxygen Species/metabolism ; Setaria Nematode/*drug effects/metabolism ; Sulfonamides/chemistry/*pharmacology/therapeutic use ; Wolbachia/drug effects/metabolism ; }, abstract = {Search of potent antifilarial drugs has been a major thrust area in tropical medicine research over the decades. Herein, we report 4,7-dimethyl-3,4,7,8-tetrahydro-3λ[6]-[1,2]thiazino[4,3-f]quinoline-3,3,8-trione (8l) as a new class of antifilarial agent which is extremely potent, with lethality against all the developmental stages (oocyte, microfilaria and adult) of the filarial parasite Setaria cervi. Molecular investigation on its mode of action revealed that 8l is a typical inducer of reactive oxygen species that triggers oxidative stress inside the filarid and further signals induction of apoptosis by activating both intrinsic and extrinsic pathways. Moreover, 8l is also active against Wolbachia, the essential endosymbiont of several human infectious filarids. Selective toxicity against filarial parasites and non-toxic nature in rat model were found as unique traits of 8l to be a future medicine. Taken en masse, this maiden report on a novel quinolone fused cyclic sulfonamide presents a promising therapeutic lead for lymphatic filariasis in future.}, }
@article {pmid30103809, year = {2018}, author = {Budachetri, K and Kumar, D and Crispell, G and Beck, C and Dasch, G and Karim, S}, title = {The tick endosymbiont Candidatus Midichloria mitochondrii and selenoproteins are essential for the growth of Rickettsia parkeri in the Gulf Coast tick vector.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {141}, pmid = {30103809}, issn = {2049-2618}, support = {P20 GM103476/GM/NIGMS NIH HHS/United States ; P20 RR016476/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Arachnid Vectors/genetics/metabolism/microbiology ; Arthropod Proteins/genetics/metabolism ; Female ; Gene Expression Regulation, Bacterial ; Gene Silencing ; Gulf of Mexico ; Male ; Oxidative Stress ; Rickettsia/*growth &amp; development ; Rickettsiaceae/*physiology ; Selenoproteins/*genetics/metabolism ; Symbiosis ; Ticks/genetics/metabolism/*microbiology ; Up-Regulation ; }, abstract = {BACKGROUND: Pathogen colonization inside tick tissues is a significant aspect of the overall competence of a vector. Amblyomma maculatum is a competent vector of the spotted fever group rickettsiae, Rickettsia parkeri. When R. parkeri colonizes its tick host, it has the opportunity to dynamically interact with not just its host but with the endosymbionts living within it, and this enables it to modulate the tick's defenses by regulating tick gene expression. The microbiome in A. maculatum is dominated by two endosymbiont microbes: a Francisella-like endosymbiont (FLE) and Candidatus Midichloria mitochondrii (CMM). A range of selenium-containing proteins (selenoproteins) in A. maculatum ticks protects them from oxidative stress during blood feeding and pathogen infections. Here, we investigated rickettsial multiplication in the presence of tick endosymbionts and characterized the functional significance of selenoproteins during R. parkeri replication in the tick.<br><br>RESULTS: FLE and CMM were quantified throughout the tick life stages by quantitative PCR in R. parkeri-infected and uninfected ticks. R. parkeri infection was found to decrease the FLE numbers but CMM thrived across the tick life cycle. Our qRT-PCR analysis indicated that the transcripts of genes with functions related to redox (selenogenes) were upregulated in ticks infected with R. parkeri. Three differentially expressed proteins, selenoprotein M, selenoprotein O, and selenoprotein S were silenced to examine their functional significance during rickettsial replication within the tick tissues. Gene silencing of the target genes was found to impair R. parkeri colonization in the tick vector. Knockdown of the selenogenes triggered a compensatory response from other selenogenes, as observed by changes in gene expression, but oxidative stress levels and endoplasmic reticulum stress inside the ticks were also found to have heightened.<br><br>CONCLUSIONS: This study illustrates the potential of this new research model for augmenting our understanding of the pathogen interactions occurring within tick hosts and the important roles that symbionts and various tick factors play in regulating pathogen growth.}, }
@article {pmid30102395, year = {2018}, author = {Manzano-Marín, A and Coeur d'acier, A and Clamens, AL and Orvain, C and Cruaud, C and Barbe, V and Jousselin, E}, title = {A Freeloader? The Highly Eroded Yet Large Genome of the Serratia symbiotica Symbiont of Cinara strobi.}, journal = {Genome biology and evolution}, volume = {10}, number = {9}, pages = {2178-2189}, pmid = {30102395}, issn = {1759-6653}, mesh = {Animals ; Aphids/*microbiology/physiology ; Biological Evolution ; Buchnera/*genetics/isolation &amp; purification/physiology ; Enterobacteriaceae/*genetics/isolation &amp; purification/physiology ; *Genome, Bacterial ; Metabolic Networks and Pathways ; Serratia/*genetics/isolation &amp; purification/physiology ; *Symbiosis ; }, abstract = {Genome reduction is pervasive among maternally inherited bacterial endosymbionts. This genome reduction can eventually lead to serious deterioration of essential metabolic pathways, thus rendering an obligate endosymbiont unable to provide essential nutrients to its host. This loss of essential pathways can lead to either symbiont complementation (sharing of the nutrient production with a novel co-obligate symbiont) or symbiont replacement (complete takeover of nutrient production by the novel symbiont). However, the process by which these two evolutionary events happen remains somewhat enigmatic by the lack of examples of intermediate stages of this process. Cinara aphids (Hemiptera: Aphididae) typically harbor two obligate bacterial symbionts: Buchnera and Serratia symbiotica. However, the latter has been replaced by different bacterial taxa in specific lineages, and thus species within this aphid lineage could provide important clues into the process of symbiont replacement. In the present study, using 16S rRNA high-throughput amplicon sequencing, we determined that the aphid Cinara strobi harbors not two, but three fixed bacterial symbionts: Buchnera aphidicola, a Sodalis sp., and S. symbiotica. Through genome assembly and genome-based metabolic inference, we have found that only the first two symbionts (Buchnera and Sodalis) actually contribute to the hosts' supply of essential nutrients while S. symbiotica has become unable to contribute towards this task. We found that S. symbiotica has a rather large and highly eroded genome which codes only for a few proteins and displays extensive pseudogenization. Thus, we propose an ongoing symbiont replacement within C. strobi, in which a once "competent" S. symbiotica does no longer contribute towards the beneficial association. These results suggest that in dual symbiotic systems, when a substitute cosymbiont is available, genome deterioration can precede genome reduction and a symbiont can be maintained despite the apparent lack of benefit to its host.}, }
@article {pmid30100341, year = {2018}, author = {LaJeunesse, TC and Parkinson, JE and Gabrielson, PW and Jeong, HJ and Reimer, JD and Voolstra, CR and Santos, SR}, title = {Systematic Revision of Symbiodiniaceae Highlights the Antiquity and Diversity of Coral Endosymbionts.}, journal = {Current biology : CB}, volume = {28}, number = {16}, pages = {2570-2580.e6}, doi = {10.1016/j.cub.2018.07.008}, pmid = {30100341}, issn = {1879-0445}, mesh = {Animals ; Anthozoa/*physiology ; Biological Evolution ; Coral Reefs ; Dinoflagellida/*classification/*physiology ; *Symbiosis ; }, abstract = {The advent of molecular data has transformed the science of organizing and studying life on Earth. Genetics-based evidence provides fundamental insights into the diversity, ecology, and origins of many biological systems, including the mutualisms between metazoan hosts and their micro-algal partners. A well-known example is the dinoflagellate endosymbionts ("zooxanthellae") that power the growth of stony corals and coral reef ecosystems. Once assumed to encompass a single panmictic species, genetic evidence has revealed a divergent and rich diversity within the zooxanthella genus Symbiodinium. Despite decades of reporting on the significance of this diversity, the formal systematics of these eukaryotic microbes have not kept pace, and a major revision is long overdue. With the consideration of molecular, morphological, physiological, and ecological data, we propose that evolutionarily divergent Symbiodinium "clades" are equivalent to genera in the family Symbiodiniaceae, and we provide formal descriptions for seven of them. Additionally, we recalibrate the molecular clock for the group and amend the date for the earliest diversification of this family to the middle of the Mesozoic Era (∼160 mya). This timing corresponds with the adaptive radiation of analogs to modern shallow-water stony corals during the Jurassic Period and connects the rise of these symbiotic dinoflagellates with the emergence and evolutionary success of reef-building corals. This improved framework acknowledges the Symbiodiniaceae's long evolutionary history while filling a pronounced taxonomic gap. Its adoption will facilitate scientific dialog and future research on the physiology, ecology, and evolution of these important micro-algae.}, }
@article {pmid30097664, year = {2018}, author = {Lastovetsky, OA and Ahn, E and Mondo, SJ and Toomer, KH and Zhang, A and Johnson, LM and Pawlowska, TE}, title = {Distribution and population structure of endobacteria in arbuscular mycorrhizal fungi at North Atlantic dunes.}, journal = {The ISME journal}, volume = {12}, number = {12}, pages = {3001-3013}, pmid = {30097664}, issn = {1751-7370}, mesh = {Burkholderiaceae/genetics/*physiology ; Glomeromycota/genetics/*physiology ; Massachusetts ; Mycorrhizae/genetics/*physiology ; Phylogeny ; Plant Roots/microbiology ; Plants/*microbiology ; Soil Microbiology ; *Symbiosis ; }, abstract = {Arbuscular mycorrhizal fungi (AMF, Glomeromycotina), in addition to forming symbioses with the majority of land plants, harbor vertically transmitted endosymbiotic bacteria 'Candidatus Glomeribacter gigasporarum' (CaGg) and 'Candidatus Moeniiplasma glomeromycotorum' (CaMg). CaGg is a nonessential mutualist of AMF, whereas the lifestyle of CaMg is unknown. To start unraveling the interactions between AMF and their endosymbionts in nature, we examined diversity and distribution of AMF-associated endobacteria in North Atlantic dunes at Cape Cod. Of nearly 500 foredune AMF isolates successfully genotyped during a systematic study, 94% were classified as Gigasporaceae. Two percent of all AMF spores harbored CaGg, and 88% contained CaMg. CaGg was found only in the Gigasporaceae, whereas CaMg was present in Gigasporaceae, Acaulosporaceae, and Diversisporaceae. Incidence of CaGg across AMF was not affected by any of the environmental parameters measured, whereas distribution of CaMg in one of the fungal hosts was impacted by plant density. CaMg populations associated with AMF individuals displayed high levels of genetic diversity but no evidence of gene flow, suggesting that host physical proximity is not sufficient to facilitate horizontal transmission of CaMg. Finally, in addition to a novel lineage of CaGg, we discovered that AMF likely harbor Burkholderia-related bacteria with close phylogenetic affinity to free-living Burkholderia and endobacteria of other Mucoromycota fungi.}, }
@article {pmid30092356, year = {2018}, author = {Jiang, W and Zhu, J and Wu, Y and Li, L and Li, Y and Ge, C and Wang, Y and Endersby, NM and Hoffmann, AA and Yu, W}, title = {Influence of Wolbachia infection on mitochondrial DNA variation in the genus Polytremis (Lepidoptera: Hesperiidae).}, journal = {Molecular phylogenetics and evolution}, volume = {129}, number = {}, pages = {158-170}, doi = {10.1016/j.ympev.2018.08.001}, pmid = {30092356}, issn = {1095-9513}, mesh = {Animals ; Cell Nucleus/genetics ; China ; DNA, Mitochondrial/*genetics ; Female ; *Genetic Variation ; Geography ; Haplotypes/genetics ; Lepidoptera/*genetics/*microbiology ; Likelihood Functions ; Male ; Multilocus Sequence Typing ; Phylogeny ; Population Density ; Time Factors ; Wolbachia/*physiology ; }, abstract = {The maternally inherited obligate bacteria Wolbachia is known for infecting the reproductive tissues of a wide range of arthropods and can contribute to phylogenetically discordant patterns between mtDNA and nDNA. In this study, we tested for an association between mito-nuclear discordance in Polytremis and Wolbachia infection. Six of the 17 species of Polytremis were found to be infected with Wolbachia. Overall, 34% (70/204) of Polytremis specimens were Wolbachia positive and three strains of Wolbachia identified using a wsp marker were further characterized as six strains based on MLST markers. Wolbachia acquisition in Polytremis appears to occur mainly through horizontal transmission rather than codivergence based on comparison of the divergence times of Wolbachia and Polytremis species. At the intraspecific level, one of the Wolbachia infections (wNas1) is associated with reduced mtDNA polymorphism in the infected Polytremis population. At the interspecific level, there is one case of mito-nuclear discordance likely caused by introgression of P. fukia mtDNA into P. nascens driven by another Wolbachia strain (wNas3). Based on an absence of infected males, we suspect that one Wolbachia strain (wNas2) affects sex ratio, but the phenotypic effects of the other strains are unclear. These data reveal a dynamic interaction between Polytremis and Wolbachia endosymbionts affecting patterns of mtDNA variation.}, }
@article {pmid30086814, year = {2018}, author = {Yurchenko, V and Lukeš, J}, title = {Parasites and their (endo)symbiotic microbes.}, journal = {Parasitology}, volume = {145}, number = {10}, pages = {1261-1264}, doi = {10.1017/S0031182018001257}, pmid = {30086814}, issn = {1469-8161}, mesh = {Animals ; Biological Evolution ; Organelles ; Parasites/*microbiology ; *Symbiosis ; }, abstract = {Thanks to modern molecular biology methods, our understanding of the impact of (endo)symbiotic bacteria on parasitic protists and helminths is growing fast. In this issue, 9 papers have been brought together that describe various facets of the relationships between these microorganisms, reveal their range and high frequency, as well as their capacity to create novel biological complexity. Comparative analyses of these host-endosymbiont interactions indicate that there may be no discrete types of relationships but rather a continuum ranging from a dispensable endosymbiont minimally integrated within the host cell to organelles, such as mitochondria and plastids that evolved into an indispensable, deeply integrated components of the cell. We hope that this series of studies on parasites and (endo)symbiotic bacteria will increase awareness about these relationships and their representation in microbial ecology models.}, }
@article {pmid30085216, year = {2018}, author = {Dubie, TR and Turner, J and Noden, BH}, title = {Questing Behavior and Analysis of Tick-Borne Bacteria in Ixodes scapularis (Acari: Ixodidae) in Oklahoma.}, journal = {Journal of medical entomology}, volume = {55}, number = {6}, pages = {1569-1574}, doi = {10.1093/jme/tjy133}, pmid = {30085216}, issn = {1938-2928}, mesh = {Animals ; *Behavior, Animal ; Female ; Ixodes/*microbiology ; Male ; Oklahoma ; }, abstract = {The blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae), is an economically important tick that affects veterinary and public health, but it can be difficult to collect in Oklahoma. The primary goal of this research was to examine the diel activity of each species to help improve collection methods for future field research and test field-collected I. scapularis for endemic and nonendemic tick-borne bacterial genera in the southern Great Plains region. Questing behavior was observed using caged bioassays over 24-h periods throughout fall and spring, and field collections were conducted throughout the afternoon and evening in different locations across Oklahoma. Blacklegged ticks were found to be more active during late afternoon and evening hours, and more ticks were recovered in pastures in the evening. None of the pools of adult I. scapularis tested positive for Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) or Anaplasma phagocytophilum (Rickettsiales: Anaplasmataceae) DNA. Of the 46 pools of I. scapularis tested, 27 (58.7%) were positive for Rickettsia sp. with ticks collected from the same location infected with the same species of rickettsial endosymbionts. Results suggest that sampling times later in the day may benefit off-host recovery of I. scapularis in Oklahoma ecosystems.}, }
@article {pmid30085124, year = {2018}, author = {Grosche, C and Diehl, A and Rensing, SA and Maier, UG}, title = {Iron-Sulfur Cluster Biosynthesis in Algae with Complex Plastids.}, journal = {Genome biology and evolution}, volume = {10}, number = {8}, pages = {2061-2071}, pmid = {30085124}, issn = {1759-6653}, mesh = {Cell Compartmentation ; Cryptophyta/genetics/*metabolism ; Cytosol/metabolism ; Diatoms/genetics ; Genome ; Iron-Sulfur Proteins/*biosynthesis ; Models, Biological ; Phylogeny ; Plastids/*metabolism ; }, abstract = {Plastids surrounded by four membranes harbor a special compartment between the outer and inner plastid membrane pair, the so-called periplastidal compartment (PPC). This cellular structure is usually presumed to be the reduced cytoplasm of a eukaryotic phototrophic endosymbiont, which was integrated into a host cell and streamlined into a plastid with a complex membrane structure. Up to date, no mitochondrion or mitochondrion-related organelle has been identified in the PPC of any representative. However, two prominent groups, the cryptophytes and the chlorarachniophytes, still harbor a reduced cell nucleus of symbiont origin, the nucleomorph, in their PPCs. Generally, many cytoplasmic and nucleus-located eukaryotic proteins need an iron-sulfur cofactor for their functionality. Beside some exceptions, their synthesis is depending on a so-called iron-sulfur complex (ISC) assembly machinery located in the mitochondrion. This machinery provides the cytoplasm with a still unknown sulfur component, which is then converted into iron-sulfur clusters via a cytosolic iron-sulfur protein assembly (CIA) machinery. Here, we investigated if a CIA machinery is present in mitochondrion-lacking PPCs. By using bioinformatic screens and in vivo-localizations of candidate proteins, we show that the presence of a PPC-specific CIA machinery correlates with the presence of a nucleomorph. Phylogenetic analyses of PPC- and host specific CIA components additionally indicate a complex evolution of the CIA machineries in organisms having plastids surrounded by four membranes.}, }
@article {pmid30083465, year = {2018}, author = {Matsuo, E and Inagaki, Y}, title = {Patterns in evolutionary origins of heme, chlorophyll a and isopentenyl diphosphate biosynthetic pathways suggest non-photosynthetic periods prior to plastid replacements in dinoflagellates.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e5345}, pmid = {30083465}, issn = {2167-8359}, abstract = {BACKGROUND: The ancestral dinoflagellate most likely established a peridinin-containing plastid, which have been inherited in the extant photosynthetic descendants. However, kareniacean dinoflagellates and Lepidodinium species were known to bear "non-canonical" plastids lacking peridinin, which were established through haptophyte and green algal endosymbioses, respectively. For plastid function and maintenance, the aforementioned dinoflagellates were known to use nucleus-encoded proteins vertically inherited from the ancestral dinoflagellates (vertically inherited- or VI-type), and those acquired from non-dinoflagellate organisms (including the endosymbiont). These observations indicated that the proteomes of the non-canonical plastids derived from a haptophyte and a green alga were modified by "exogenous" genes acquired from non-dinoflagellate organisms. However, there was no systematic evaluation addressing how "exogenous" genes reshaped individual metabolic pathways localized in a non-canonical plastid.<br><br>RESULTS: In this study, we surveyed transcriptomic data from two kareniacean species (Karenia brevis and Karlodinium veneficum) and Lepidodinium chlorophorum, and identified proteins involved in three plastid metabolic pathways synthesizing chlorophyll a (Chl a), heme and isoprene. The origins of the individual proteins of our interest were investigated, and we assessed how the three pathways were modified before and after the algal endosymbioses, which gave rise to the current non-canonical plastids. We observed a clear difference in the contribution of VI-type proteins across the three pathways. In both Karenia/Karlodinium and Lepidodinium, we observed a substantial contribution of VI-type proteins to the isoprene and heme biosynthesises. In sharp contrast, VI-type protein was barely detected in the Chl a biosynthesis in the three dinoflagellates.<br><br>DISCUSSION: Pioneering works hypothesized that the ancestral kareniacean species had lost the photosynthetic activity prior to haptophyte endosymbiosis. The absence of VI-type proteins in the Chl a biosynthetic pathway in Karenia or Karlodinium is in good agreement with the putative non-photosynthetic nature proposed for their ancestor. The dominance of proteins with haptophyte origin in the Karenia/Karlodinium pathway suggests that their ancestor rebuilt the particular pathway by genes acquired from the endosymbiont. Likewise, we here propose that the ancestral Lepidodinium likely experienced a non-photosynthetic period and discarded the entire Chl a biosynthetic pathway prior to the green algal endosymbiosis. Nevertheless, Lepidodinium rebuilt the pathway by genes transferred from phylogenetically diverse organisms, rather than the green algal endosymbiont. We explore the reasons why green algal genes were barely utilized to reconstruct the Lepidodinium pathway.}, }
@article {pmid30065740, year = {2018}, author = {Kereszt, A and Mergaert, P and Montiel, J and Endre, G and Kondorosi, &#xc9;}, title = {Impact of Plant Peptides on Symbiotic Nodule Development and Functioning.}, journal = {Frontiers in plant science}, volume = {9}, number = {}, pages = {1026}, pmid = {30065740}, issn = {1664-462X}, abstract = {Ribosomally synthesized peptides have wide ranges of functions in plants being, for example, signal molecules, transporters, alkaloids, or antimicrobial agents. Legumes are an unprecedented rich source of peptides, which are used to control the symbiosis of these plants with the nitrogen-fixing Rhizobium bacteria. Here, we discuss the function and the evolution of these peptides playing an important role in the formation or functioning of the symbiotic organs, the root nodules. We distinguish peptides that can be either cell-autonomous or secreted short-range or long-range signals, carrying messages in or between plant cells or that can act as effectors interacting with the symbiotic bacteria. Peptides are further classified according to the stage of the symbiotic process where they act. Several peptide classes, including RALF, DLV, ENOD40, and others, control Rhizobium infection and the initiation of cell divisions and the formation of nodule primordia. CLE and CEP peptides are implicated in systemic and local control of nodule initiation during autoregulation of nodulation and in response to the nutritional demands of the plant. Still other peptides act at later stages of the symbiosis. The PSK peptide is thought to be involved in the suppression of immunity in nodules and the nodule-specific cysteine-rich, GRP, and SNARP (LEED..PEED) peptide families are essential in the functioning of the nitrogen fixing root nodules. The NCRs and possibly also the GRP and SNARPs are targeted to the endosymbionts and play essential roles in the terminal differentiation of these bacteria.}, }
@article {pmid30061694, year = {2018}, author = {Fisher, ML and Watson, DW and Osborne, JA and Mochizuki, H and Breen, M and Schal, C}, title = {Growth kinetics of endosymbiont Wolbachia in the common bed bug, Cimex lectularius.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {11444}, pmid = {30061694}, issn = {2045-2322}, support = {P30 ES025128/ES/NIEHS NIH HHS/United States ; NCHHU0017-13//U.S. Department of Housing and Urban Development (HUD)/International ; 2013-5-35 MBE//Alfred P. Sloan Foundation/International ; }, mesh = {Animals ; Bedbugs/*microbiology ; DNA/genetics ; Female ; Kinetics ; Larva/microbiology ; *Symbiosis ; Wolbachia/*growth &amp; development ; }, abstract = {The common bed bug, Cimex lectularius harbors the endosymbiotic microorganism, Wolbachia (wCle), in a gonad-associated bacteriome as an obligate nutritional mutualist. The obligatory nature of this association suggests that all individuals in C. lectularius populations would be infected with wCle. However, studies spanning the past several decades have reported variation in both infection frequency and relative abundance of wCle in field-collected samples of bed bugs. Since the growth kinetics of wCle is poorly understood, the objective of this study was to quantify wCle over the life cycle of two strains of C. lectularius. Our results highlight that wCle is dynamic during bed bug development, changing relative to life stage, intermolt stage, and blood-fed status. These results suggest new hypotheses about the coordination of Wolbachia growth and regression with its host's physiology and endocrine events. The observed quantitative modulation of wCle during the bed bug life cycle and during periods of starvation may explain the disparities in wCle infections reported in field-collected C. lectularius.}, }
@article {pmid30060189, year = {2018}, author = {Río Bártulos, C and Rogers, MB and Williams, TA and Gentekaki, E and Brinkmann, H and Cerff, R and Liaud, MF and Hehl, AB and Yarlett, NR and Gruber, A and Kroth, PG and van der Giezen, M}, title = {Mitochondrial Glycolysis in a Major Lineage of Eukaryotes.}, journal = {Genome biology and evolution}, volume = {10}, number = {9}, pages = {2310-2325}, pmid = {30060189}, issn = {1759-6653}, support = {//Wellcome Trust/United Kingdom ; 078566/A/05/Z//Wellcome Trust/United Kingdom ; }, mesh = {Biological Evolution ; Blastocystis/cytology/enzymology/genetics/*metabolism ; Diatoms/cytology/enzymology/genetics/*metabolism ; Energy Metabolism ; Genome, Mitochondrial ; *Glycolysis ; Mitochondria/genetics/*metabolism ; Symbiosis ; Transformation, Genetic ; }, abstract = {The establishment of the mitochondrion is seen as a transformational step in the origin of eukaryotes. With the mitochondrion came bioenergetic freedom to explore novel evolutionary space leading to the eukaryotic radiation known today. The tight integration of the bacterial endosymbiont with its archaeal host was accompanied by a massive endosymbiotic gene transfer resulting in a small mitochondrial genome which is just a ghost of the original incoming bacterial genome. This endosymbiotic gene transfer resulted in the loss of many genes, both from the bacterial symbiont as well the archaeal host. Loss of genes encoding redundant functions resulted in a replacement of the bulk of the host's metabolism for those originating from the endosymbiont. Glycolysis is one such metabolic pathway in which the original archaeal enzymes have been replaced by bacterial enzymes from the endosymbiont. Glycolysis is a major catabolic pathway that provides cellular energy from the breakdown of glucose. The glycolytic pathway of eukaryotes appears to be bacterial in origin, and in well-studied model eukaryotes it takes place in the cytosol. In contrast, here we demonstrate that the latter stages of glycolysis take place in the mitochondria of stramenopiles, a diverse and ecologically important lineage of eukaryotes. Although our work is based on a limited sample of stramenopiles, it leaves open the possibility that the mitochondrial targeting of glycolytic enzymes in stramenopiles might represent the ancestral state for eukaryotes.}, }
@article {pmid30056075, year = {2018}, author = {Ciuca, L and Simòn, F and Rinaldi, L and Kramer, L and Genchi, M and Cringoli, G and Acatrinei, D and Miron, L and Morchon, R}, title = {Seroepidemiological survey of human exposure to Dirofilaria spp. in Romania and Moldova.}, journal = {Acta tropica}, volume = {187}, number = {}, pages = {169-174}, doi = {10.1016/j.actatropica.2018.07.012}, pmid = {30056075}, issn = {1873-6254}, mesh = {Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Antibodies, Helminth/*immunology ; Antigens, Helminth/*immunology ; Child ; Dirofilaria/*immunology ; Dirofilaria immitis/immunology ; Dirofilaria repens/immunology ; Dirofilariasis/*epidemiology/immunology ; Dog Diseases/epidemiology ; Dogs ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Moldova/epidemiology ; Prevalence ; Romania/epidemiology ; Seroepidemiologic Studies ; Surveys and Questionnaires ; Wolbachia/immunology ; Young Adult ; }, abstract = {The present study aimed to evaluate the extent of Dirofilaria immitis and D. repens exposure in humans from eastern and southern areas of Romania and central Moldova by serological methods. The serological screening was performed on a total of 450 serum samples (187 from Romania and 263 from Moldova). The sera were collected using a convenience sampling with the help of physicians from the hospitals of the study areas. All samples were analysed by a non-commercial ELISA test for the detection of IgG antibodies against adult somatic antigens of D. immitis and D. repens. The results showed a total of 49 (10.9%; 95% CI = 8.3-14.1%) individuals from Romania and Moldova with a positive response to IgG antibodies against both adult somatic antigens of D. immitis and D. repens. Specifically, 48 (10.7%; 95% CI = 8.0-14.0%) patients were positive for IgG-antibodies against adult somatic antigens of D. immitis, one (0.2%; 95% CI = 0.4-1.2%) against D. repens antigens, and four (0.9%; 95% CI = 0.4-3.3%). were positive for antigens of both parasites. At country level, out of 187 samples from Romania, 13 (6.9%; 95% CI = 4.1-11.5%) were positive for anti-D. immitis IgG with high exposure in the southern part of the country (Bucharest). Of the 263 people from Moldova, 36 (13.7%; 95% CI = 10.0-18.4%) were positive for D. immitis antigens from which three (1.1%, 95% CI = 0.4-3.3%) were positive for the antibodies against antigens of both parasites. Only one sample was found positive for anti-D. repens IgG. Positive IgG-ELISA results were confirmed by Western blot analysis. In addition, for further confirmation, a complementary ELISA was performed for anti-WSP IgG antibodies against Wolbachia endosymbionts. Our findings showed a noticeable exposure of humans from Romania and Moldova to Dirofilaria parasites. Serology can be useful for indicating exposure to Dirofilaria spp. in a healthy population in order to obtain useful data on the epidemiological scenario of human dirofilariosis in Eastern Europe.}, }
@article {pmid30055063, year = {2019}, author = {Rangsrikitphoti, P and Durnford, DG}, title = {Transcriptome Profiling of Bigelowiella natans in Response to Light Stress.}, journal = {The Journal of eukaryotic microbiology}, volume = {66}, number = {2}, pages = {316-333}, doi = {10.1111/jeu.12672}, pmid = {30055063}, issn = {1550-7408}, mesh = {Cercozoa/*genetics/physiology/radiation effects ; Gene Expression Profiling ; RNA-Seq ; Stress, Physiological/genetics ; Sunlight ; *Transcriptome/radiation effects ; }, abstract = {Bigelowiella natans is a marine chlorarachniophyte whose plastid was acquired secondarily via endosymbiosis with a green alga. During plastid evolution, the photosynthetic endosymbiont would have integrated with the host metabolic pathways. This would require the evolution and coordination of strategies to cope with changes in light intensity that includes changes in the expression of both endosymbiont and host-derived genes. To investigate the transcriptional response to light intensity in chlorarachniophytes, we conducted an RNA-seq experiment to identify differentially expressed genes following a 4-h shift to high or very-low light. A shift to high light altered the expression of over 2,000 genes, many involved with photosynthesis, PSII assembly, primary metabolism, and reactive-oxygen scavenging. These changes are an attempt to optimize photosynthesis and increase energy sinks for excess reductant, while minimizing photooxidative stress. A transfer to very-low light resulted in a lower photosynthetic performance and metabolic alteration, reflecting an energy-limited state. Genes located on the nucleomorph, the vestigial nucleus in the plastid, had few changes in expression in either light treatment, indicating this organelle has relinquished most transcriptional control to the nucleus. Overall, during plastid origin, both host and transferred endosymbiont genes evolved a harmonized transcriptional network to respond to a classic photosynthetic stress.}, }
@article {pmid30052670, year = {2018}, author = {Rossitto De Marchi, B and Kinene, T and Mbora Wainaina, J and Krause-Sakate, R and Boykin, L}, title = {Comparative transcriptome analysis reveals genetic diversity in the endosymbiont Hamiltonella between native and exotic populations of Bemisia tabaci from Brazil.}, journal = {PloS one}, volume = {13}, number = {7}, pages = {e0201411}, pmid = {30052670}, issn = {1932-6203}, mesh = {Animals ; *Enterobacteriaceae/classification/genetics/metabolism ; *Gene Expression Profiling ; *Genetic Variation ; Hemiptera/*microbiology ; *Phylogeny ; Symbiosis/*physiology ; }, abstract = {The whitefly, Bemisia tabaci, is a species complex of more than 40 cryptic species and a major agricultural pest. It causes extensive damage to plants mainly by transmitting plant viruses. There is still a lack of genomic data available for the different whitefly species found in Brazil and their bacterial endosymbionts. Understanding the genetic and transcriptomic composition of these insect pests, the viruses they transmit and the microbiota is crucial to sustainable solutions for farmers to control whiteflies. Illumina RNA-Seq was used to obtain the transcriptome of individual whiteflies from 10 different populations from Brazil including Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED) and New World 2 (NW2). Raw reads were assembled using CLC Genomics Workbench and subsequently mapped to reference genomes. We obtained whitefly complete mitochondrial genomes and draft genomes from the facultative bacterial endosymbiont Hamiltonella for further phylogenetic analyses. In addition, nucleotide sequences of the GroEL chaperonin gene from Hamiltonella from different populations were obtained and analysed. There was concordance in the species clustering using the whitefly complete mitogenome and the mtCOI gene tree. On the other hand, the phylogenetic analysis using the 12 ORF's of Hamiltonella clustered the native species NW2 apart from the exotics MEAM1 and MED. In addition, the amino acid analysis of GroEL chaperonin revealed a deletion only in Hamiltonella infecting NW2 among whiteflies populations analysed which was further confirmed by PCR and Sanger sequencing. The genomic data obtained in this study will aid understanding the functions that Hamiltonella may have in whitefly biology and serve as a reference for further studies regarding whiteflies in Brazil.}, }
@article {pmid30049880, year = {2018}, author = {Dinh, C and Farinholt, T and Hirose, S and Zhuchenko, O and Kuspa, A}, title = {Lectins modulate the microbiota of social amoebae.}, journal = {Science (New York, N.Y.)}, volume = {361}, number = {6400}, pages = {402-406}, doi = {10.1126/science.aat2058}, pmid = {30049880}, issn = {1095-9203}, mesh = {Biological Transport ; DNA, Bacterial/metabolism ; Dictyostelium/*metabolism/*microbiology ; Discoidins/*metabolism ; Klebsiella pneumoniae/metabolism/*physiology ; Microbiota/*physiology ; Symbiosis ; }, abstract = {The social amoeba Dictyostelium discoideum maintains a microbiome during multicellular development; bacteria are carried in migrating slugs and as endosymbionts within amoebae and spores. Bacterial carriage and endosymbiosis are induced by the secreted lectin discoidin I that binds bacteria, protects them from extracellular killing, and alters their retention within amoebae. This altered handling of bacteria also occurs with bacteria coated by plant lectins and leads to DNA transfer from bacteria to amoebae. Thus, lectins alter the cellular response of D. discoideum to bacteria to establish the amoebae's microbiome. Mammalian cells can also maintain intracellular bacteria when presented with bacteria coated with lectins, so heterologous lectins may induce endosymbiosis in animals. Our results suggest that endogenous or environmental lectins may influence microbiome homeostasis across eukaryotic phylogeny.}, }
@article {pmid30049746, year = {2018}, author = {James, EB and Feng, H and Wilson, ACC}, title = {mTOR Complex 1 Implicated in Aphid/Buchnera Host/Symbiont Integration.}, journal = {G3 (Bethesda, Md.)}, volume = {8}, number = {9}, pages = {3083-3091}, pmid = {30049746}, issn = {2160-1836}, mesh = {Animals ; *Aphids/genetics/growth &amp; development/microbiology ; Buchnera/*physiology ; Gene Duplication ; *Insect Proteins/genetics/metabolism ; *Mechanistic Target of Rapamycin Complex 1/genetics/metabolism ; Signal Transduction/*physiology ; Symbiosis/*physiology ; }, abstract = {Obligate nutritional endosymbioses are arguably the most intimate of all interspecific associations. While many insect nutritional endosymbioses are well studied, a full picture of how two disparate organisms, a bacterial endosymbiont and a eukaryotic host, are integrated is still lacking. The mTOR pathway is known to integrate nutritional conditions with cell growth and survival in eukaryotes. Characterization and localization of amino acid transporters in aphids suggest the mTOR pathway as a point of integration between an aphid host and its amino acid-provisioning endosymbiont Buchnera aphidicola The mTOR pathway is unannotated in aphids and unstudied in any nutritional endosymbiosis. We annotated mTOR pathway genes in two aphid species, Acyrthosiphon pisum and Myzus persicae, using both BLASTp searches and Hidden Markov Models. Using previously collected RNAseq data we constructed new reference transcriptomes for bacteriocyte, gut, and whole insect tissue for three lines of M. persicae Annotation of the mTOR pathway identified homologs of all known invertebrate mTOR genes in both aphid species with some duplications. Differential expression analysis showed that genes specific to the amino acid-sensitive mTOR Complex 1 were more highly expressed in bacteriocytes than genes specific to the amino acid-insensitive mTOR Complex 2. Almost all mTOR genes involved in sensing amino acids showed higher expression in bacteriocytes than in whole insect tissue. When compared to gut, the putative glutamine/arginine sensing transporter ACYPI000333, an ortholog of SLC38A9, showed 6.5 times higher expression in bacteriocytes. Our results suggest that the mTOR pathway may be functionally important in mediating integration of Buchnera into aphid growth and reproduction.}, }
@article {pmid30045904, year = {2018}, author = {Tabata, J and Teshiba, M}, title = {Sexual attractiveness and reproductive performance in ageing females of a coccoid insect.}, journal = {Biology letters}, volume = {14}, number = {7}, pages = {}, pmid = {30045904}, issn = {1744-957X}, mesh = {Aging ; Animals ; Female ; Fertility/physiology ; Male ; *Mating Preference, Animal ; Planococcus Insect/microbiology/*physiology ; Reproduction/physiology ; Sex Attractants/*metabolism ; Symbiosis ; }, abstract = {Female age strongly influences reproductive success in various animals. Males are, therefore, expected to show preferential responses to sexual signals released from females of ages suitable for reproduction. Here, however, we report an unexpected and contradictory effect of ageing on sexual attractiveness and reproductive performance in a coccoid insect: the pheromone-based attractiveness of females increased with ageing, though their reproductive performance was in rapid decline. Surprisingly, senescent females continued releasing relatively high amounts of pheromone and maintained their sexual attractiveness, even at ages when they had almost completely lost fertility, with reduced densities of endosymbionts to support their physiology. Our dataset suggests a potential sexual conflict within a pheromone communication system, where females benefit at males' expense through deceptive signals of fertility.}, }
@article {pmid30045585, year = {2018}, author = {Wei, Z and Liu, Y and Feng, K and Li, S and Wang, S and Jin, D and Zhang, Y and Chen, H and Yin, H and Xu, M and Deng, Y}, title = {The divergence between fungal and bacterial communities in seasonal and spatial variations of wastewater treatment plants.}, journal = {The Science of the total environment}, volume = {628-629}, number = {}, pages = {969-978}, doi = {10.1016/j.scitotenv.2018.02.003}, pmid = {30045585}, issn = {1879-1026}, mesh = {Bacteria/*classification ; Biodiversity ; Fungi/*classification ; Seasons ; *Waste Disposal, Fluid ; Waste Water/*microbiology ; }, abstract = {In this study, quantitative PCR (qPCR) and high-throughput sequencing were used to simultaneously examine both bacteria and fungi across temporal and spatial scales in activated sludge from wastewater treatment plants (WWTPs). The ratio of fungi to bacteria was 0.43% on average after accounting for the multicopies in 16S rRNA gene (54.63%), indicating the number of fungi was far lower than bacteria in active sludge. The Miseq sequencing results revealed obvious seasonal and spatial variations in bacterial and fungal distribution patterns in WWTPs. Compared to bacteria, fungi showed a lower divergence in alpha and beta diversity, and exhibited less taxonomic diversity in both abundant and rare subcommunities at the class level, suggesting that the fungal community was less variable in this artificial ecosystem. Such variation of microbial communities was significantly correlated with geographical distance, DO, temperature, HRT, SRT, COD, TN and TP. In activated sludge, the main function of bacteria was chemoheterotrophy, fermentation, and nitrogen cycling processes, while the dominant functional guilds of fungi were saprotroph, animal pathogen, and animal endosymbiont. Moreover, both bacteria and fungi could play important roles in the degradation of toxicants, like hydrocarbon and aromatic compounds.}, }
@article {pmid30039630, year = {2018}, author = {Sun, ZJ and Li, ZX}, title = {The terpenoid backbone biosynthesis pathway directly affects the biosynthesis of alarm pheromone in the aphid.}, journal = {Insect molecular biology}, volume = {27}, number = {6}, pages = {824-834}, doi = {10.1111/imb.12521}, pmid = {30039630}, issn = {1365-2583}, mesh = {Animals ; Aphids/genetics/*metabolism ; Body Size ; Fertility ; Gene Expression Regulation ; Mortality ; Pheromones/*biosynthesis ; RNA Interference ; Sesquiterpenes/*metabolism ; }, abstract = {The terpenoid backbone biosynthesis pathway is responsible for the synthesis of different backbones for terpenoids; (E)-β-farnesene (EβF), a sesquiterpene, is the major component of aphid alarm pheromone. Our previous studies eliminated the possibility of host plants and endosymbionts as the sources of EβF, and we thus speculate that the terpenoid pathway might affect the biosynthesis of EβF in aphids. First, the transcriptional responses of four genes encoding farnesyl diphosphate synthase (FPPS), geranylgeranyl diphosphate synthase (GGPPS) and decaprenyl diphosphate synthase in the cotton aphid Aphis gossypii to simulated stimulation were analysed using quantitative real-time PCR, showing an immediate decrease in the transcript abundances of the four genes. Next, RNA-interference-mediated gene knockdown was performed, indicating that fpps knockdown caused a significant cost in terms of body size and fecundity. Finally, an association analysis of gene knockdown with the amount of EβF was conducted, revealing that the concentration of EβF per milligram of aphid was drastically decreased in response to fpps knockdown, whereas ggpps knockdown significantly raised the concentration of EβF. Our data support a peculiar mode of biosynthesis and storage of the aphid alarm pheromone that relies directly on the terpenoid backbone biosynthesis pathway in the aphid.}, }
@article {pmid30038485, year = {2018}, author = {Karimi, K and Wuitchik, DM and Oldach, MJ and Vize, PD}, title = {Distinguishing Species Using GC Contents in Mixed DNA or RNA Sequences.}, journal = {Evolutionary bioinformatics online}, volume = {14}, number = {}, pages = {1176934318788866}, pmid = {30038485}, issn = {1176-9343}, support = {P41 HD064556/HD/NICHD NIH HHS/United States ; }, abstract = {With the advent of whole transcriptome and genome analysis methods, classifying samples containing multiple origins has become a significant task. Nucleotide sequences can be allocated to a genome or transcriptome by aligning sequences to multiple target sequence sets, but this approach requires extensive computational resources and also depends on target sequence sets lacking contaminants, which is often not the case. Here, we demonstrate that raw sequences can be rapidly sorted into groups, in practice corresponding to genera, by exploiting differences in nucleotide GC content. To do so, we introduce GCSpeciesSorter, which uses classification, specifically Support Vector Machines (SVM) and the C4.5 decision tree generator, to differentiate sequences. It also implements a secondary BLAST feature to identify known outliers. In the test case presented, a hermatypic coral holobiont, the cnidarian host includes various endosymbionts. The best characterized and most common of these symbionts are zooxanthellae of the genus Symbiodinium. GCSpeciesSorter separates cnidarian from Symbiodinium sequences with a high degree of accuracy. We show that if the GC contents of the species differ enough, this method can be used to accurately distinguish the sequences of different species when using high-throughput sequencing technologies.}, }
@article {pmid30022157, year = {2018}, author = {Li, Y and Liles, MR and Halanych, KM}, title = {Endosymbiont genomes yield clues of tubeworm success.}, journal = {The ISME journal}, volume = {12}, number = {11}, pages = {2785-2795}, pmid = {30022157}, issn = {1751-7370}, mesh = {Animals ; Bacteria/genetics/metabolism ; Carbon Cycle ; Chemoautotrophic Growth ; Ecosystem ; Hydrogen/metabolism ; Hydrothermal Vents ; Photosynthesis ; Polychaeta/*microbiology ; *Symbiosis ; }, abstract = {Forty years after discovery of chemosynthetic symbiosis in the tubeworm Riftia pachyptila, how organisms maintain their unique host-symbiont associations at the cellular level is still largely unknown. Previous studies primarily focus on symbionts associated with host lineages living in hydrothermal vents. To understand physiological adaptations and evolution in these holobiont systems in markedly different habitats, we characterized four novel siboglinid-symbiont genomes spanning deep-sea seep and sedimented environments. Our comparative analyses suggest that all sampled siboglinid chemoautotrophic symbionts, except for frenulate symbionts, can use both rTCA and Calvin cycle for carbon fixation. We hypothesize that over evolutionary time siboglinids have been able to utilize different bacterial lineages allowing greater metabolic flexibility of carbon fixation (e.g., rTCA) enabling tubeworms to thrive in more reducing habitats, such as vents and seeps. Moreover, we show that sulfur metabolism and molecular mechanisms related to initial infection are remarkably conserved across chemoautotrophic symbionts in different habitats. Unexpectedly, we find that the ability to use hydrogen, as an additional energy source, is potentially more widespread than previously recognized. Our comparative genomic results help elucidate potential mechanisms used to allow chemosynthetically dependent holobionts adapt to, and evolve in, different environments.}, }
@article {pmid30020933, year = {2018}, author = {Moretti, R and Yen, PS and Houé, V and Lampazzi, E and Desiderio, A and Failloux, AB and Calvitti, M}, title = {Combining Wolbachia-induced sterility and virus protection to fight Aedes albopictus-borne viruses.}, journal = {PLoS neglected tropical diseases}, volume = {12}, number = {7}, pages = {e0006626}, pmid = {30020933}, issn = {1935-2735}, mesh = {Aedes/genetics/*microbiology/*physiology ; Animals ; Breeding ; Chikungunya Fever/transmission/virology ; Chikungunya virus/physiology ; Dengue/transmission/virology ; Dengue Virus/physiology ; Female ; Humans ; Infertility ; Male ; Mosquito Control/*methods ; Mosquito Vectors/genetics/*microbiology/*physiology ; Wolbachia/*physiology ; Zika Virus/physiology ; Zika Virus Infection/transmission/virology ; }, abstract = {Among the strategies targeting vector control, the exploitation of the endosymbiont Wolbachia to produce sterile males and/or invasive females with reduced vector competence seems to be promising. A new Aedes albopictus transinfection (ARwP-M) was generated by introducing wMel Wolbachia in the ARwP line which had been established previously by replacing wAlbA and wAlbB Wolbachia with the wPip strain. Various infection and fitness parameters were studied by comparing ARwP-M, ARwP and wild-type (SANG population) Ae. albopictus sharing the same genetic background. Moreover, the vector competence of ARwP-M related to chikungunya, dengue and zika viruses was evaluated in comparison with ARwP. ARwP-M showed a 100% rate of maternal inheritance of wMel and wPip Wolbachia. Survival, female fecundity and egg fertility did not show to differ between the three Ae. albopictus lines. Crosses between ARwP-M males and SANG females were fully unfertile regardless of male age while egg hatch in reverse crosses increased from 0 to about 17% with SANG males aging from 3 to 17 days. When competing with SANG males for SANG females, ARwP-M males induced a level of sterility significantly higher than that expected for an equal mating competitiveness (mean Fried index of 1.71 instead of 1). The overall Wolbachia density in ARwP-M females was about 15 fold higher than in ARwP, mostly due to the wMel infection. This feature corresponded to a strongly reduced vector competence for chikungunya and dengue viruses (in both cases, 5 and 0% rates of transmission at 14 and 21 days post infection) with respect to ARwP females. Results regarding Zika virus did not highlight significant differences between ARwP-M and ARwP. However, none of the tested ARwP-M females was capable at transmitting ZIKV. These findings are expected to promote the exploitation of Wolbachia to suppress the wild-type Ae. albopictus populations.}, }
@article {pmid30017075, year = {2018}, author = {Kamani, J and Harrus, S and Nachum-Biala, Y and Salant, H and Mumcuoglu, KY and Baneth, G}, title = {Pathogenic and endosymbiont apicomplexans in Ctenocephalides felis (Siphonaptera: Pulicidae) from cats in Jerusalem, Israel.}, journal = {Comparative immunology, microbiology and infectious diseases}, volume = {57}, number = {}, pages = {29-33}, doi = {10.1016/j.cimid.2018.03.002}, pmid = {30017075}, issn = {1878-1667}, mesh = {Animals ; Apicomplexa/classification/genetics/*isolation &amp; purification ; Babesia/classification/genetics/*isolation &amp; purification ; Cat Diseases/*epidemiology/parasitology ; Cats ; Ctenocephalides/parasitology/physiology ; Eucoccidiida/classification/genetics/*isolation &amp; purification ; Female ; Flea Infestations/epidemiology/parasitology/*veterinary ; Israel/epidemiology ; Male ; Prevalence ; Seasons ; *Symbiosis ; }, abstract = {This study was conducted to determine the prevalence of pathogenic and endosymbiont apicomplexans in the cat flea, Ctenocephalides felis (Bouché) infesting 185 stray cats in Jerusalem, Israel using PCR assay and sequencing approach. Two pathogens, Hepatozoon felis and Babesia vogeli and an endosymbiont Steinina ctenocephali were detected in 1.9%, 0.2% and 5.8% of 685 C. felis evaluated respectively. There was a significant association (p < 0.05) between the prevalence of H. felis and the sex of cats hosting the fleas as well as the season of sampling but not for age or health status of the cats or sex of the fleas tested. Prevalence of S. ctenocephali was significantly (p < 0.001) associated with season, being higher in the warm season. This report represents the first molecular detection of S. ctenocephali in C. felis. Further studies to determine the potential role of C. felis in the epidemiology of H. felis and B. vogeli are warranted.}, }
@article {pmid30013530, year = {2018}, author = {Li, LH and Zhang, Y and Zhu, D and Zhou, XN}, title = {Endosymbionts Alter Larva-to-Nymph Transstadial Transmission of Babesia microti in Rhipicephalus haemaphysaloides Ticks.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {1415}, pmid = {30013530}, issn = {1664-302X}, abstract = {Maternally inherited endosymbionts inhabit a variety of arthropods. Some of them can protect the arthropod host against a wide range of pathogens. However, very little is known about the association between endosymbionts and pathogen susceptibility in ticks. The present study investigated the effect of endosymbionts on larva-to-nymph transstadial transmission of Babesia microti by Rhipicephalus haemaphysaloides ticks. Engorged female ticks were injected with PBS, ciprofloxacin or kanamycin. The offspring larvae were used to infest B. microti-positive mice. Prevalence of B. microti among the nymphs in different treatment groups and its association with endosymbiont density in the larvae were analyzed. The results showed that the prevalence of B. microti in the kanamycin-treated group (63.9%, 95% confidence interval (CI): 52.8-75.0%) was higher than that in the PBS (23.6%, 95% CI: 13.8-33.4%) or ciprofloxacin-treated (25.0%, 95% CI: 15.0-35.0%) groups. This increased prevalence was associated with reduced density of Coxiella-like endosymbiont but was not related to the density of Rickettsia-like endosymbiont. No direct evidence has previously been reported about the impact of Coxiella-like endosymbiont on pathogen susceptibility in ticks. This study reveals that endosymbionts are potentially important defensive symbionts of R. haemaphysaloides which may influence the colonization or susceptibility of B. microti in the tick host.}, }
@article {pmid29991760, year = {2018}, author = {Lind, AE and Lewis, WH and Spang, A and Guy, L and Embley, TM and Ettema, TJG}, title = {Genomes of two archaeal endosymbionts show convergent adaptations to an intracellular lifestyle.}, journal = {The ISME journal}, volume = {12}, number = {11}, pages = {2655-2667}, pmid = {29991760}, issn = {1751-7370}, mesh = {Ciliophora/*microbiology ; Euryarchaeota/*genetics ; Evolution, Molecular ; *Genome, Archaeal ; Genomics ; Symbiosis/*genetics ; }, abstract = {Endosymbiosis is a widespread phenomenon in the microbial world and can be based on diverse interactions between endosymbiont and host cell. The vast majority of the known endosymbiotic interactions involve bacteria that have invaded eukaryotic host cells. However, methanogenic archaea have been found to thrive in anaerobic, hydrogenosome-containing protists and it was suggested that this symbiosis is based on the transfer of hydrogen. Here, we used culture-independent genomics approaches to sequence the genomes of two distantly related methanogenic endosymbionts that have been acquired in two independent events by closely related anaerobic ciliate hosts Nyctotherus ovalis and Metopus contortus, respectively. The sequences obtained were then validated as originating from the ciliate endosymbionts by in situ probing experiments. Comparative analyses of these genomes and their closest free-living counterparts reveal that the genomes of both endosymbionts are in an early stage of adaptation towards endosymbiosis as evidenced by the large number of genes undergoing pseudogenization. For instance, the observed loss of genes involved in amino acid biosynthesis in both endosymbiont genomes indicates that the endosymbionts rely on their hosts for obtaining several essential nutrients. Furthermore, the endosymbionts appear to have gained significant amounts of genes of potentially secreted proteins, providing targets for future studies aiming to elucidate possible mechanisms underpinning host-interactions. Altogether, our results provide the first genomic insights into prokaryotic endosymbioses from the archaeal domain of life.}, }
@article {pmid29990378, year = {2018}, author = {Vicente, CSL and Mondal, SI and Akter, A and Ozawa, S and Kikuchi, T and Hasegawa, K}, title = {Genome analysis of new Blattabacterium spp., obligatory endosymbionts of Periplaneta fuliginosa and P. japonica.}, journal = {PloS one}, volume = {13}, number = {7}, pages = {e0200512}, pmid = {29990378}, issn = {1932-6203}, mesh = {Ammonia/chemistry ; Animals ; Bacteroidetes/*genetics ; Blattellidae/*microbiology ; DNA, Bacterial/genetics ; *Genome, Bacterial ; Male ; Nitrogen/chemistry ; Periplaneta/*microbiology ; Phylogeny ; Symbiosis ; Urea/chemistry ; Uric Acid/chemistry ; }, abstract = {The successful adaptation of cockroaches is, in part, dependent of the activity of their obligatory endosymbionts, Blattabacterium spp., which are involved in uric acid degradation, nitrogen assimilation and nutrient provisioning. Their strategic localization, within bacteriocytes in the proximities of uric acid storage cells (urocytes), highlights their importance in the recycling of nitrogen from urea and ammonia, end-products not secreted by their host insects. In this study, we present the complete genome sequence of two new Blattabacterium spp. from Periplaneta fuliginosa (BPfu) and P. japonica (BPja), and detailed comparison with other Blattabacterium strains from different cockroach species. The genomes of BPfu and BPja show a high degree of stability as showed with for other Blattabacterium representatives, only presenting a 19-kb fragment inversion between BPja and BPfu. In fact, the phylogenomics showed BPja as an ancestor species of BPfu, BPLAN (P. americana) and BBor (Blatta orientalis), in congruence with their host cockroach phylogeny. Their functional profile is similar and closest to the omnivorous strain BBge (Blattella germanica). Interesting, BPja possesses the complete set of enzymes involved sulfate assimilatory pathway only found in BBge and BMda (Mastotermes darwiniensis). The newly sequenced genomes of BPja and BPfu emphasise the remarkable stability of Blattabacterium genomes supported by their long-term coevolution and obligatory lifestyle in their host insect.}, }
@article {pmid29989657, year = {2018}, author = {Guo, Y and Hoffmann, AA and Xu, XQ and Zhang, X and Huang, HJ and Ju, JF and Gong, JT and Hong, XY}, title = {Wolbachia-induced apoptosis associated with increased fecundity in Laodelphax striatellus (Hemiptera: Delphacidae).}, journal = {Insect molecular biology}, volume = {27}, number = {6}, pages = {796-807}, doi = {10.1111/imb.12518}, pmid = {29989657}, issn = {1365-2583}, support = {//Medical Research Council/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; *Apoptosis ; Caspases/genetics/*metabolism ; Female ; Fertility ; Genetic Fitness ; Hemiptera/microbiology/*physiology ; Ovary/microbiology/physiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia influence the fitness of their invertebrate hosts. They have effects on reproductive incompatibility and egg production. Although the former are well characterized, the mechanistic basis of the latter is unclear. Here, we investigate whether apoptosis, which has been implicated in fecundity in model insects, influences the interaction between fecundity and Wolbachia in the planthopper Laodelphax striatellus. Wolbachia-infected females produced about 30% more eggs than uninfected females. We used the terminal deoxyribonucleotidyl transferase (TDT)-mediated dUTP-digoxigenin nick end labeling staining to visualize apoptosis. Microscopic observations indicated that the Wolbachia strain wStri increased the number of ovarioles that contained apoptotic nurse cells in both young and aged adult females. The frequency of apoptosis was much higher in the infected females. The increased fecundity appeared to be a result of apoptosis of nurse cells, which provide nutrients to the growing oocytes. In addition, cell apoptosis inhibition by caspase messenger RNA interference in Wolbachia-infected L. striatellus markedly decreased egg numbers. Together, these data suggest that wStri might enhance fecundity by increasing the number of apoptotic cells in the ovaries in a caspase-dependent manner. Our findings establish a link between Wolbachia-induced apoptosis and egg production effects mediated by Wolbachia, although the way in which the endosymbiont influences caspase levels remains to be determined.}, }
@article {pmid29988277, year = {2018}, author = {Rana, G}, title = {Inhibition efficiency of a newly isolated flavonoid compound from Vitex negundo L. leaves against cattle-endosymbiont Setaria cervi: Phytomedicine for lymphatic filariasis.}, journal = {Parasite epidemiology and control}, volume = {3}, number = {2}, pages = {88-95}, pmid = {29988277}, issn = {2405-6731}, abstract = {Experimental studies has been carried out to isolate and identify an active antifilarial compound from Vitex negundo L. plant as it has been used for treatment against filariasis in Indian traditional system of medicine. In vitro antifilarial assay has been carried out against adult filarial parasite Setaria cervi worms by both worm motility and MTT reduction assays. Levels of oxidative stress parameters MDA, carbonyl content and nitric oxide levels have been detected. The isolated compound exhibited significant antifilarial activity in dose dependent manner. The active compound has been chemically characterized and identified as 4,5-diethyl-3'-ethoxy-pyro-flavone.}, }
@article {pmid29987712, year = {2018}, author = {Füssy, Z and Oborník, M}, title = {Complex Endosymbioses I: From Primary to Complex Plastids, Multiple Independent Events.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {1829}, number = {}, pages = {17-35}, doi = {10.1007/978-1-4939-8654-5_2}, pmid = {29987712}, issn = {1940-6029}, mesh = {Biological Evolution ; Eukaryota/classification/genetics/metabolism ; Photosynthesis ; Plastids/*genetics/*metabolism ; *Symbiosis ; }, abstract = {A substantial portion of eukaryote diversity consists of algae with complex plastids, i.e., plastids originating from eukaryote-to-eukaryote endosymbioses. These plastids are characteristic by a deviating number of envelope membranes (higher than two), and sometimes a remnant nucleus of the endosymbiont alga, termed the nucleomorph, is present. Complex plastid-bearing algae are therefore much like living matryoshka dolls, eukaryotes within eukaryotes. In comparison, primary plastids of Archaeplastida (plants, green algae, red algae, and glaucophytes) arose upon a single endosymbiosis event with a cyanobacterium and are surrounded by two membranes. Complex plastids were acquired several times by unrelated groups nested within eukaryotic heterotrophs, suggesting complex plastids are somewhat easier to obtain than primary plastids. This is consistent with the existence of higher-order and serial endosymbioses, i.e., engulfment of complex plastid-bearing algae by (tertiary) eukaryotic hosts and functional plastid replacements, respectively. Plastid endosymbiosis is typical by a massive transfer of genetic material from the endosymbiont to the host nucleus and metabolic rearrangements related to the trophic switch to phototrophy; this is necessary to establish metabolic integration of the plastid and control over its division. Although photosynthesis is the main advantage of plastid acquisition, algae that lost photosynthesis often maintain complex plastids, suggesting their roles beyond photosynthesis. This chapter summarizes basic knowledge on acquisition and functions of complex plastid.}, }
@article {pmid29982531, year = {2018}, author = {Bisch, G and Neuvonen, MM and Pierce, NE and Russell, JA and Koga, R and Sanders, JG and Lukasik, P and Andersson, SGE}, title = {Genome Evolution of Bartonellaceae Symbionts of Ants at the Opposite Ends of the Trophic Scale.}, journal = {Genome biology and evolution}, volume = {10}, number = {7}, pages = {1687-1704}, pmid = {29982531}, issn = {1759-6653}, mesh = {Animal Nutritional Physiological Phenomena ; Animals ; Ants/anatomy &amp; histology/*microbiology/physiology/ultrastructure ; Bartonellaceae/*genetics/physiology ; *Evolution, Molecular ; Gastrointestinal Microbiome ; Genome Size ; *Genome, Bacterial ; Phylogeny ; Symbiosis ; }, abstract = {Many insects rely on bacterial symbionts to supply essential amino acids and vitamins that are deficient in their diets, but metabolic comparisons of closely related gut bacteria in insects with different dietary preferences have not been performed. Here, we demonstrate that herbivorous ants of the genus Dolichoderus from the Peruvian Amazon host bacteria of the family Bartonellaceae, known for establishing chronic or pathogenic infections in mammals. We detected these bacteria in all studied Dolichoderus species, and found that they reside in the midgut wall, that is, the same location as many previously described nutritional endosymbionts of insects. The genomic analysis of four divergent strains infecting different Dolichoderus species revealed genes encoding pathways for nitrogen recycling and biosynthesis of several vitamins and all essential amino acids. In contrast, several biosynthetic pathways have been lost, whereas genes for the import and conversion of histidine and arginine to glutamine have been retained in the genome of a closely related gut bacterium of the carnivorous ant Harpegnathos saltator. The broad biosynthetic repertoire in Bartonellaceae of herbivorous ants resembled that of gut bacteria of honeybees that likewise feed on carbohydrate-rich diets. Taken together, the broad distribution of Bartonellaceae across Dolichoderus ants, their small genome sizes, the specific location within hosts, and the broad biosynthetic capability suggest that these bacteria are nutritional symbionts in herbivorous ants. The results highlight the important role of the host nutritional biology for the genomic evolution of the gut microbiota-and conversely, the importance of the microbiota for the nutrition of hosts.}, }
@article {pmid29971900, year = {2018}, author = {Truitt, AM and Kapun, M and Kaur, R and Miller, WJ}, title = {Wolbachia modifies thermal preference in Drosophila melanogaster.}, journal = {Environmental microbiology}, volume = {21}, number = {9}, pages = {3259-3268}, pmid = {29971900}, issn = {1462-2920}, support = {P 28255/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Environmental variation can have profound and direct effects on fitness, fecundity, and host-symbiont interactions. Replication rates of microbes within arthropod hosts, for example, are correlated with incubation temperature but less is known about the influence of host-symbiont dynamics on environmental preference. Hence, we conducted thermal preference (Tp) assays and tested if infection status and genetic variation in endosymbiont bacterium Wolbachia affected temperature choice of Drosophila melanogaster. We demonstrate that isogenic flies infected with Wolbachia preferred lower temperatures compared with uninfected Drosophila. Moreover, Tp varied with respect to three investigated Wolbachia variants (wMel, wMelCS, and wMelPop). While uninfected individuals preferred 24.4°C, we found significant shifts of -1.2°C in wMel- and -4°C in flies infected either with wMelCS or wMelPop. We, therefore, postulate that Wolbachia-associated Tp variation within a host species might represent a behavioural accommodation to host-symbiont interactions and trigger behavioural self-medication and bacterial titre regulation by the host.}, }
@article {pmid29954916, year = {2018}, author = {Showmaker, KC and Walden, KKO and Fields, CJ and Lambert, KN and Hudson, ME}, title = {Genome Sequence of the Soybean Cyst Nematode (Heterodera glycines) Endosymbiont "Candidatus Cardinium hertigii" Strain cHgTN10.}, journal = {Genome announcements}, volume = {6}, number = {26}, pages = {}, pmid = {29954916}, issn = {2169-8287}, abstract = {In this study, we present the genome sequence of the "Candidatus Cardinium hertigii" strain cHgTN10, an endosymbiotic bacterium of the plant-parasitic nematode Heterodera glycines This is the first genome assembly reported for an endosymbiont directly sequenced from a tylenchid nematode.}, }
@article {pmid29954410, year = {2018}, author = {Radzijevskaja, J and Kaminskienė, E and Lipatova, I and Mardosaitė-Busaitienė, D and Balčiauskas, L and Stanko, M and Paulauskas, A}, title = {Prevalence and diversity of Rickettsia species in ectoparasites collected from small rodents in Lithuania.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {375}, pmid = {29954410}, issn = {1756-3305}, mesh = {Animals ; DNA, Bacterial/genetics ; Ectoparasitic Infestations/*epidemiology ; *Genetic Variation ; Ixodes/*microbiology ; Lithuania/epidemiology ; Mites/*microbiology ; Prevalence ; Rickettsia/*genetics/isolation &amp; purification/pathogenicity ; Rickettsia Infections/epidemiology/microbiology/transmission ; Rodentia/microbiology ; Siphonaptera/*microbiology ; }, abstract = {BACKGROUND: Rickettsiae are emerging pathogens causing public health problems in many countries around the world. Rickettsia spp. are found in association with a wide range of arthropods which feed on different species of animals. However, the distribution and natural cycle of Rickettsia species and their association with different arthropod vectors are not fully established. The aim of this study was to investigate the presence and prevalence of Rickettsia spp. in ticks, mites and fleas parasitizing different species of small mammals in Lithuania and to molecularly characterize the Rickettsia spp. obtained from different ectoparasites.<br><br>RESULTS: A total of 1261 ectoparasites (596 Ixodes ricinus ticks, 550 mites of five species and 115 fleas of eight species) collected from 238 rodents in Lithuania during 2013-2014 were investigated for the presence of Rickettsia pathogens. Infection rates were calculated as the maximum likelihood estimation (MLE) with 95% confidence intervals (CI). The infection rate varied among ectoparasites and was found highest in fleas 43.5%, followed by I. ricinus ticks (MLE = 26.5%; 95% CI: 22.2-31.3%) and then mites (MLE = 9.3%; 95% CI: 7.0-12.2%). Sequence analysis of partial gltA and 17kDa genes revealed the presence of Rickettsia helvetica, R. felis, R. monacensis, Rickettsia sp. and rickettsial endosymbionts. Four Rickettsia spp. were identified in fleas, while three Rickettsia spp. were identified in Laelapidae mites and only one (R. helvetica) in I. ricinus ticks.<br><br>CONCLUSIONS: To our knowledge, this is the first report of the occurrence and molecular characterization of Rickettsia spp. in 11 species of ectoparasites of small rodents in Lithuania. The present data extend the knowledge on the distribution of Rickettsia spp. and their association with different arthropod vectors. Prior to our study, R. felis had never been identified in Lithuania. To our knowledge, this is also the first report of R. felis in L. agilis and H. microti mites and in Ct. agyrtes and H. talpae fleas, as well as the first detection of R. monacensis in Ct. agyrtes fleas.}, }
@article {pmid29947761, year = {2018}, author = {Faria, VG and Martins, NE and Schlötterer, C and Sucena, &#xc9;}, title = {Readapting to DCV Infection without Wolbachia: Frequency Changes of Drosophila Antiviral Alleles Can Replace Endosymbiont Protection.}, journal = {Genome biology and evolution}, volume = {10}, number = {7}, pages = {1783-1791}, pmid = {29947761}, issn = {1759-6653}, support = {P 27630/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Adaptation, Physiological ; Alleles ; Animals ; Drosophila melanogaster/genetics/*microbiology/physiology/*virology ; Genome, Insect ; Host-Pathogen Interactions ; Insect Viruses/*physiology ; Polymorphism, Genetic ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {There is now ample evidence that endosymbionts can contribute to host adaptation to environmental challenges. However, how endosymbiont presence affects the adaptive trajectory and outcome of the host is yet largely unexplored. In Drosophila, Wolbachia confers protection to RNA virus infection, an effect that differs between Wolbachia strains and can be targeted by selection. Adaptation to RNA virus infections is mediated by both Wolbachia and the host, raising the question of whether adaptive genetic changes in the host vary with the presence/absence of the endosymbiont. Here, we address this question using a polymorphic D. melanogaster population previously adapted to DCV infection for 35 generations in the presence of Wolbachia, from which we removed the endosymbiont and followed survival over the subsequent 20 generations of infection. After an initial severe drop, survival frequencies upon DCV selection increased significantly, as seen before in the presence of Wolbachia. Whole-genome sequencing, revealed that the major genes involved in the first selection experiment, pastrel and Ubc-E2H, continued to be selected in Wolbachia-free D. melanogaster, with the frequencies of protective alleles being closer to fixation in the absence of Wolbachia. Our results suggest that heterogeneity in Wolbachia infection status may be sufficient to maintain polymorphisms even in the absence of costs.}, }
@article {pmid29946243, year = {2018}, author = {Münger, E and Montiel-Castro, AJ and Langhans, W and Pacheco-López, G}, title = {Reciprocal Interactions Between Gut Microbiota and Host Social Behavior.}, journal = {Frontiers in integrative neuroscience}, volume = {12}, number = {}, pages = {21}, pmid = {29946243}, issn = {1662-5145}, abstract = {Animals harbor an extensive, dynamic microbial ecosystem in their gut. Gut microbiota (GM) supposedly modulate various host functions including fecundity, metabolism, immunity, cognition and behavior. Starting by analyzing the concept of the holobiont as a unit of selection, we highlight recent findings suggesting an intimate link between GM and animal social behavior. We consider two reciprocal emerging themes: (i) that GM influence host social behavior; and (ii) that social behavior and social structure shape the composition of the GM across individuals. We propose that, throughout a long history of coevolution, GM may have become involved in the modulation of their host's sociality to foster their own transmission, while in turn social organization may have fine-tuned the transmission of beneficial endosymbionts and prevented pathogen infection. We suggest that investigating these reciprocal interactions can advance our understanding of sociality, from healthy and impaired social cognition to the evolution of specific social behaviors and societal structure.}, }
@article {pmid29946195, year = {2018}, author = {Ross, BD and Hayes, B and Radey, MC and Lee, X and Josek, T and Bjork, J and Neitzel, D and Paskewitz, S and Chou, S and Mougous, JD}, title = {Ixodes scapularis does not harbor a stable midgut microbiome.}, journal = {The ISME journal}, volume = {12}, number = {11}, pages = {2596-2607}, pmid = {29946195}, issn = {1751-7370}, support = {R21 AI114923/AI/NIAID NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Borrelia/genetics ; Dermacentor/microbiology ; *Gastrointestinal Microbiome ; Ixodes/*microbiology ; Ixodidae/microbiology ; }, abstract = {Hard ticks of the order Ixodidae serve as vectors for numerous human pathogens, including the causative agent of Lyme Disease Borrelia burgdorferi. Tick-associated microbes can influence pathogen colonization, offering the potential to inhibit disease transmission through engineering of the tick microbiota. Here, we investigate whether B. burgdorferi encounters abundant bacteria within the midgut of wild adult Ixodes scapularis, its primary vector. Through the use of controlled sequencing methods and confocal microscopy, we find that the majority of field-collected adult I. scapularis harbor limited internal microbial communities that are dominated by endosymbionts. A minority of I. scapularis ticks harbor abundant midgut bacteria and lack B. burgdorferi. We find that the lack of a stable resident midgut microbiota is not restricted to I. scapularis since extension of our studies to I. pacificus, Amblyomma maculatum, and Dermacentor spp showed similar patterns. Finally, bioinformatic examination of the B. burgdorferi genome revealed the absence of genes encoding known interbacterial interaction pathways, a feature unique to the Borrelia genus within the phylum Spirochaetes. Our results suggest that reduced selective pressure from limited microbial populations within ticks may have facilitated the evolutionary loss of genes encoding interbacterial competition pathways from Borrelia.}, }
@article {pmid29946049, year = {2018}, author = {Lehman, SS and Noriea, NF and Aistleitner, K and Clark, TR and Dooley, CA and Nair, V and Kaur, SJ and Rahman, MS and Gillespie, JJ and Azad, AF and Hackstadt, T}, title = {The Rickettsial Ankyrin Repeat Protein 2 Is a Type IV Secreted Effector That Associates with the Endoplasmic Reticulum.}, journal = {mBio}, volume = {9}, number = {3}, pages = {}, pmid = {29946049}, issn = {2150-7511}, support = {R01 AI017828/AI/NIAID NIH HHS/United States ; R01 AI126853/AI/NIAID NIH HHS/United States ; R21 AI126108/AI/NIAID NIH HHS/United States ; T32 AI007540/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/chemistry/genetics/*metabolism ; Endoplasmic Reticulum/genetics/*metabolism ; Female ; Guinea Pigs ; Humans ; Protein Transport ; Rickettsia rickettsii/chemistry/genetics/*metabolism/pathogenicity ; Rocky Mountain Spotted Fever/microbiology ; Type IV Secretion Systems/chemistry/genetics/*metabolism ; Virulence ; }, abstract = {Strains of Rickettsia rickettsii, the tick-borne agent of Rocky Mountain spotted fever, vary considerably in virulence. Genomic comparisons of R. rickettsii strains have identified a relatively small number of genes divergent in an avirulent strain. Among these is one annotated as Rickettsia ankyrin repeat protein 2 (RARP-2). Homologs of RARP-2 are present in all strains of R. rickettsii, but the protein in the avirulent strain Iowa contains a large internal deletion relative to the virulent Sheila Smith strain. RARP-2 is secreted in a type IV secretion system-dependent manner and exposed to the host cell cytosol. RARP-2 of Sheila Smith colocalizes with multilamellar membranous structures bearing markers of the endoplasmic reticulum (ER), whereas the Iowa protein shows no colocalization with host cell organelles and evidence of proteolytic degradation is detected. Overexpression of Sheila Smith RARP-2 in R. rickettsii Iowa converts this avirulent strain's typically nonlytic or opaque plaque type to a lytic plaque phenotype similar to that of the virulent Sheila Smith strain. Mutation of a predicted proteolytic active site of Sheila Smith RARP-2 abolished the lytic plaque phenotype but did not eliminate association with host membrane. RARP-2 is thus a type IV secreted effector and released from the rickettsiae into the host cytosol to modulate host processes during infection. Overexpression of Sheila Smith RARP-2 did not, however, restore the virulence of the Iowa strain in a guinea pig model, likely due to the multifactorial nature of rickettsial virulence.IMPORTANCE Members of the genus Rickettsia are obligate intracellular bacteria that exhibit a range of virulence from harmless endosymbionts of arthropods to the etiologic agents of severe disease. Despite the growing number of available genomes, little is known regarding virulence determinants of rickettsiae. Here, we have characterized an ankyrin repeat-containing protein, RARP-2, which differs between a highly virulent and an avirulent strain of R. rickettsii, the agent of Rocky Mountain spotted fever. RARP-2 is secreted by a type IV secretion system into the cytosol of the host cell, where it interacts with and manipulates the structure of the endoplasmic reticulum. RARP-2 from the avirulent strain is truncated by the loss of seven of 10 ankyrin repeat units but, although secreted, fails to alter ER structure. Recognition of those rickettsial factors associated with virulence will facilitate understanding of regional and strain-specific variation in severity of disease.}, }
@article {pmid29931159, year = {2018}, author = {Leobold, M and Bézier, A and Pichon, A and Herniou, EA and Volkoff, AN and Drezen, JM}, title = {The Domestication of a Large DNA Virus by the Wasp Venturia canescens Involves Targeted Genome Reduction through Pseudogenization.}, journal = {Genome biology and evolution}, volume = {10}, number = {7}, pages = {1745-1764}, pmid = {29931159}, issn = {1759-6653}, mesh = {Animals ; DNA, Viral/genetics ; Evolution, Molecular ; Gene Deletion ; Gene Dosage ; Genes, Viral ; Genome, Insect ; Genome, Viral ; Polydnaviridae/*genetics ; *Pseudogenes ; Virion/genetics ; Wasps/*genetics/*virology ; }, abstract = {Polydnaviruses (PDVs) are compelling examples of viral domestication, in which wasps express a large set of genes originating from a chromosomally integrated virus to produce particles necessary for their reproductive success. Parasitoid wasps generally use PDVs as a virulence gene delivery system allowing the protection of their progeny in the body of parasitized host. However, in the wasp Venturia canescens an independent viral domestication process led to an alternative strategy as the wasp incorporates virulence proteins in viral liposomes named virus-like particles (VLPs), instead of DNA molecules. Proteomic analysis of purified VLPs and transcriptome sequencing revealed the loss of some viral functions. In particular, the genes coding for capsid components are no longer expressed, which explains why VLPs do not incorporate DNA. Here a thorough examination of V. canescens genome revealed the presence of the pseudogenes corresponding to most of the genes involved in lost functions. This strongly suggests that an accumulation of mutations that leads to gene specific pseudogenization precedes the loss of viral genes observed during virus domestication. No evidence was found for block loss of collinear genes, although extensive gene order reshuffling of the viral genome was identified from comparisons between endogenous and exogenous viruses. These results provide the first insights on the early stages of large DNA virus domestication implicating massive genome reduction through gene-specific pseudogenization, a process which differs from the large deletions described for bacterial endosymbionts.}, }
@article {pmid29928757, year = {2018}, author = {Ye, Z and Vollhardt, IMG and Parth, N and Rubbmark, O and Traugott, M}, title = {Facultative bacterial endosymbionts shape parasitoid food webs in natural host populations: A correlative analysis.}, journal = {The Journal of animal ecology}, volume = {87}, number = {5}, pages = {1440-1451}, pmid = {29928757}, issn = {1365-2656}, mesh = {Animals ; *Aphids ; Female ; Food Chain ; Germany ; Host-Parasite Interactions ; Oviposition ; Symbiosis ; *Wasps ; }, abstract = {Facultative bacterial endosymbionts can protect their aphid hosts from natural enemies such as hymenopteran parasitoids. As such, they have the capability to modulate interactions between aphids, parasitoids and hyperparasitoids. However, the magnitude of these effects in natural aphid populations and their associated parasitoid communities is currently unknown. Moreover, environmental factors such as plant fertilization and landscape complexity are known to affect aphid-parasitoid interactions but it remains unclear how such environmental factors affect the interplay between aphids, parasitoids and endosymbionts. Here, we tested whether facultative endosymbionts confer protection to parasitoids in natural populations of the English grain aphid, Sitobion avenae, and if this is affected by plant fertilization and landscape complexity. Furthermore, we examined whether the effects of facultative endosymbionts can cascade up to the hyperparasitoid level and increase primary-hyperparasitoid food web specialization. Living aphids and mummies were collected in fertilized and unfertilized plots within 13 wheat fields in Central Germany. We assessed the occurrence of primary parasitoid, hyperparasitoid and endosymbiont species in aphids and mummies using a newly established molecular approach. Facultative endosymbiont infection rates were high across fields (~80%), independent of whether aphids were parasitized or unparasitized. Aphid mummies exhibited a significantly lower share of facultative endosymbiont infection (~38%). These findings suggest that facultative endosymbionts do not affect parasitoid oviposition behaviour, but decrease parasitoid survival in the host. Facultative endosymbiont infection rates were lower in mummies collected from fertilized compared to unfertilized plants, indicating that plant fertilization boosts the facultative endosymbiont protective effect. Furthermore, we found strong evidence for species-specific and negative cascading effects of facultative endosymbionts on primary and hyperparasitoids, respectively. Facultative endosymbionts impacted parasitoid assemblages and increased the specialization of primary-hyperparasitoid food webs: these effects were independent from and much stronger than other environmental factors. The current findings strongly suggest that facultative endosymbionts act as a driving force in aphid-parasitoid-hyperparasitoid networks: they shape insect community composition at different trophic levels and modulate, directly and indirectly, the interactions between aphids, parasitoids and their environment.}, }
@article {pmid29924337, year = {2018}, author = {Ponce-Toledo, RI and Moreira, D and López-García, P and Deschamps, P}, title = {Secondary Plastids of Euglenids and Chlorarachniophytes Function with a Mix of Genes of Red and Green Algal Ancestry.}, journal = {Molecular biology and evolution}, volume = {35}, number = {9}, pages = {2198-2204}, pmid = {29924337}, issn = {1537-1719}, support = {322669/ERC_/European Research Council/International ; }, mesh = {Chlorophyta/*genetics ; Euglenida/*genetics ; Plastids/*genetics ; Rhodophyta/*genetics ; *Symbiosis ; }, abstract = {Endosymbiosis has been common all along eukaryotic evolution, providing opportunities for genomic and organellar innovation. Plastids are a prominent example. After the primary endosymbiosis of the cyanobacterial plastid ancestor, photosynthesis spread in many eukaryotic lineages via secondary endosymbioses involving red or green algal endosymbionts and diverse heterotrophic hosts. However, the number of secondary endosymbioses and how they occurred remain poorly understood. In particular, contrasting patterns of endosymbiotic gene transfer have been detected and subjected to various interpretations. In this context, accurate detection of endosymbiotic gene transfers is essential to avoid wrong evolutionary conclusions. We have assembled a strictly selected set of markers that provides robust phylogenomic evidence suggesting that nuclear genes involved in the function and maintenance of green secondary plastids in chlorarachniophytes and euglenids have unexpected mixed red and green algal origins. This mixed ancestry contrasts with the clear red algal origin of most nuclear genes carrying similar functions in secondary algae with red plastids.}, }
@article {pmid29912912, year = {2018}, author = {Cantanhêde, LM and Fernandes, FG and Ferreira, GEM and Porrozzi, R and Ferreira, RGM and Cupolillo, E}, title = {New insights into the genetic diversity of Leishmania RNA Virus 1 and its species-specific relationship with Leishmania parasites.}, journal = {PloS one}, volume = {13}, number = {6}, pages = {e0198727}, pmid = {29912912}, issn = {1932-6203}, mesh = {Biological Coevolution/genetics ; Genetic Variation/genetics ; Genome, Viral/genetics ; Leishmania/*virology ; Leishmania braziliensis/virology ; Leishmania guyanensis/virology ; Leishmaniasis/parasitology ; Leishmaniavirus/*genetics ; Phylogeny ; Sequence Analysis, DNA ; South America ; Species Specificity ; }, abstract = {Cutaneous leishmaniasis is a neglected parasitic disease that manifests in infected individuals under different phenotypes, with a range of factors contributing to its broad clinical spectrum. One factor, Leishmania RNA Virus 1 (LRV1), has been described as an endosymbiont present in different species of Leishmania. LRV1 significantly worsens the lesion, exacerbating the immune response in both experimentally infected animals and infected individuals. Little is known about the composition and genetic diversity of these viruses. Here, we investigated the relationship between the genetic composition of LRV1 detected in strains of Leishmania (Viannia) braziliensis and L. (V.) guyanensis and the interaction between the endosymbiont and the parasitic species, analyzing an approximately 850 base pair region of the viral genome. We also included one LRV1 sequence detected in L. (V.) shawi, representing the first report of LRV1 in a species other than L. braziliensis and L. guyanensis. The results illustrate the genetic diversity of the LRV1 strains analyzed here, with smaller divergences detected among viral sequences from the same parasite species. Phylogenetic analyses showed that the LRV1 sequences are grouped according to the parasite species and possibly according to the population of the parasite in which the virus was detected, corroborating the hypothesis of joint evolution of the viruses with the speciation of Leishmania parasites.}, }
@article {pmid29901734, year = {2018}, author = {Gloria-Soria, A and Chiodo, TG and Powell, JR}, title = {Lack of Evidence for Natural Wolbachia Infections in Aedes aegypti (Diptera: Culicidae).}, journal = {Journal of medical entomology}, volume = {55}, number = {5}, pages = {1354-1356}, pmid = {29901734}, issn = {1938-2928}, support = {R01 AI101112/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*microbiology ; Animals ; *Wolbachia ; }, abstract = {Wolbachia is a genus of endosymbiotic bacteria that infects 66% of all insect species. Its major impact on insects is in reproduction: sterility, production of one sex, and/or parthenogenesis. Another effect was discovered when the disease-transmitting mosquito, Aedes aegypti Linnaeus (Diptera: Culicidae), was infected with Wolbachia isolated from Drosophila: infected female mosquitoes became less capable of transmitting diseases such as dengue fever and chikungunya. This has led to releases of Ae. aegypti carrying Wolbachia in an attempt to control disease. An open question is whether there are natural Wolbachia infections of this mosquito. We assayed DNA from 2,663 Ae. aegypti from 27 countries on six continents, 230 from laboratory strains, and 72 Aedes mascarensis MacGregor (Diptera: Culicidae) for presence of Wolbachia DNA. Within the limits of our polymerase chain reaction-based assay, we found no evidence of Wolbachia, suggesting that natural infections of this endosymbiont are unlikely to occur throughout the worldwide distribution of Ae. aegypti.}, }
@article {pmid29895637, year = {2018}, author = {Nikoh, N and Tsuchida, T and Maeda, T and Yamaguchi, K and Shigenobu, S and Koga, R and Fukatsu, T}, title = {Genomic Insight into Symbiosis-Induced Insect Color Change by a Facultative Bacterial Endosymbiont, "Candidatus Rickettsiella viridis".}, journal = {mBio}, volume = {9}, number = {3}, pages = {}, pmid = {29895637}, issn = {2150-7511}, mesh = {Animals ; Aphids/*chemistry/*microbiology ; Bacterial Proteins/genetics/metabolism ; Color ; Coxiellaceae/classification/genetics/*isolation &amp; purification/physiology ; Genome, Bacterial ; Genomics ; Phylogeny ; *Symbiosis ; }, abstract = {Members of the genus Rickettsiella are bacterial pathogens of insects and other arthropods. Recently, a novel facultative endosymbiont, "Candidatus Rickettsiella viridis," was described in the pea aphid Acyrthosiphon pisum, whose infection causes a striking host phenotype: red and green genetic color morphs exist in aphid populations, and upon infection with the symbiont, red aphids become green due to increased production of green polycyclic quinone pigments. Here we determined the complete genome sequence of the symbiont. The 1.6-Mb circular genome, harboring some 1,400 protein-coding genes, was similar to the genome of entomopathogenic Rickettsiella grylli (1.6 Mb) but was smaller than the genomes of phylogenetically allied human pathogens Coxiella burnetii (2.0 Mb) and Legionella pneumophila (3.4 Mb). The symbiont's metabolic pathways exhibited little complementarity to those of the coexisting primary symbiont Buchnera aphidicola, reflecting the facultative nature of the symbiont. The symbiont genome harbored neither polyketide synthase genes nor the evolutionarily allied fatty acid synthase genes that are suspected to catalyze the polycyclic quinone synthesis, indicating that the green pigments are produced not by the symbiont but by the host aphid. The symbiont genome retained many type IV secretion system genes and presumable effector protein genes, whose homologues in L. pneumophila were reported to modulate a variety of the host's cellular processes for facilitating infection and virulence. These results suggest the possibility that the symbiont is involved in the green pigment production by affecting the host's metabolism using the secretion machineries for delivering the effector molecules into the host cells.IMPORTANCE Insect body color is relevant to a variety of biological aspects such as species recognition, sexual selection, mimicry, aposematism, and crypsis. Hence, the bacterial endosymbiont "Candidatus Rickettsiella viridis," which alters aphid body color from red to green, is of ecological interest, given that different predators preferentially exploit either red- or green-colored aphids. Here we determined the complete 1.6-Mb genome of the symbiont and uncovered that, although the red-green color transition was ascribed to upregulated production of green polycyclic quinone pigments, the symbiont genome harbored few genes involved in the polycyclic quinone biosynthesis. Meanwhile, the symbiont genome contained type IV secretion system genes and presumable effector protein genes, whose homologues modulate eukaryotic cellular processes for facilitating infection and virulence in the pathogen Legionella pneumophila We propose the hypothesis that the symbiont may upregulate the host's production of polycyclic quinone pigments via cooption of secretion machineries and effector molecules for pathogenicity.}, }
@article {pmid29895336, year = {2018}, author = {Harmer, J and Yurchenko, V and Nenarokova, A and Lukeš, J and Ginger, ML}, title = {Farming, slaving and enslavement: histories of endosymbioses during kinetoplastid evolution.}, journal = {Parasitology}, volume = {145}, number = {10}, pages = {1311-1323}, doi = {10.1017/S0031182018000781}, pmid = {29895336}, issn = {1469-8161}, mesh = {Biodiversity ; *Biological Evolution ; Evolution, Molecular ; Genome, Protozoan ; Kinetoplastida/*genetics ; Leishmania/genetics/physiology ; *Symbiosis ; Trypanosoma/genetics/physiology ; Trypanosomatina/*genetics ; }, abstract = {Parasitic trypanosomatids diverged from free-living kinetoplastid ancestors several hundred million years ago. These parasites are relatively well known, due in part to several unusual cell biological and molecular traits and in part to the significance of a few - pathogenic Leishmania and Trypanosoma species - as aetiological agents of serious neglected tropical diseases. However, the majority of trypanosomatid biodiversity is represented by osmotrophic monoxenous parasites of insects. In two lineages, novymonads and strigomonads, osmotrophic lifestyles are supported by cytoplasmic endosymbionts, providing hosts with macromolecular precursors and vitamins. Here we discuss the two independent origins of endosymbiosis within trypanosomatids and subsequently different evolutionary trajectories that see entrainment vs tolerance of symbiont cell divisions cycles within those of the host. With the potential to inform on the transition to obligate parasitism in the trypanosomatids, interest in the biology and ecology of free-living, phagotrophic kinetoplastids is beginning to enjoy a renaissance. Thus, we take the opportunity to additionally consider the wider relevance of endosymbiosis during kinetoplastid evolution, including the indulged lifestyle and reductive evolution of basal kinetoplastid Perkinsela.}, }
@article {pmid29893631, year = {2018}, author = {Vasconcelos, EJR and Billeter, SA and Jett, LA and Meinersmann, RJ and Barr, MC and Diniz, PPVP and Oakley, BB}, title = {Assessing Cat Flea Microbiomes in Northern and Southern California by 16S rRNA Next-Generation Sequencing.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {18}, number = {9}, pages = {491-499}, doi = {10.1089/vbz.2018.2282}, pmid = {29893631}, issn = {1557-7759}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; California/epidemiology ; Cat Diseases/epidemiology/parasitology ; Cats ; Ctenocephalides/*microbiology ; DNA, Bacterial/genetics ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/*genetics ; }, abstract = {Flea-borne diseases (FBDs) impact both human and animal health worldwide. Because adult fleas are obligately hematophagous and can harbor potential pathogens, fleas act as ectoparasites of vertebrates, as well as zoonotic disease vectors. Cat fleas (Ctenocephalides felis) are important vectors of two zoonotic bacterial genera listed as priority pathogens by the National Institute of Allergy and Infectious Diseases (NIAID-USA): Bartonella spp. and Rickettsia spp., causative agents of bartonelloses and rickettsioses, respectively. In this study, we introduce the first microbiome analysis of C. felis samples from California, determining the presence and abundance of relevant pathogenic genera by characterizing the cat flea microbiome through 16S rRNA next-generation sequencing (16S-NGS). Samples from both northern (NoCal) and southern (SoCal) California were assessed to expand current knowledge regarding FBDs in the state. We identified Rickettsia and Bartonella, as well as the endosymbiont Wolbachia, as the most abundant genera, followed by less abundant taxa. In comparison to our previous study screening Californian cat fleas for rickettsiae using PCR/digestion/sequencing of the ompB gene, the 16S-NGS approach applied herein showed a 95% level of agreement in detecting Rickettsia spp. There was no overall difference in microbiome diversity between NoCal and SoCal samples. Bacterial taxa identified by 16S-NGS in this study may help to improve epidemiological investigations, pathogen surveillance efforts, and clinical diagnostics of FBDs in California and elsewhere.}, }
@article {pmid29892272, year = {2018}, author = {Frommlet, JC and Wangpraseurt, D and Sousa, ML and Guimarães, B and Medeiros da Silva, M and Kühl, M and Serôdio, J}, title = {Symbiodinium-Induced Formation of Microbialites: Mechanistic Insights From in Vitro Experiments and the Prospect of Its Occurrence in Nature.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {998}, pmid = {29892272}, issn = {1664-302X}, abstract = {Dinoflagellates in the genus Symbiodinium exhibit a variety of life styles, ranging from mutualistic endosymbioses with animal and protist hosts to free-living life styles. In culture, Symbiodinium spp. and naturally associated bacteria are known to form calcifying biofilms that produce so-called symbiolites, i.e., aragonitic microbialites that incorporate Symbiodinium as endolithic cells. In this study, we investigated (i) how algal growth and the combined physiological activity of these bacterial-algal associations affect the physicochemical macroenvironment in culture and the microenvironment within bacterial-algal biofilms, and (ii) how these interactions induce the formation of symbiolites. In batch culture, calcification typically commenced when Symbiodinium spp. growth approached stationary phase and when photosynthetic activity and its influence on pH and the carbonate system of the culture medium had already subsided, indicating that symbiolite formation is not simply a function of photosynthetic activity in the bulk medium. Physical disturbance of bacteria-algal biofilms, via repeated detaching and dispersing of the developing biofilm, generally impeded symbiolite formation, suggesting that the structural integrity of biofilms plays an important role in generating conditions conducive to calcification. Microsensor measurements of pH and O2 revealed a biofilm microenvironment characterized by high photosynthetic rates and by dynamic changes in photosynthesis and respiration with light intensity and culture age. Ca[2+] microsensor measurements confirmed the significance of the biofilm microenvironment in inducing calcification, as photosynthesis within the biofilm induced calcification without the influence of batch culture medium and under environmentally relevant flow conditions. Furthermore, first quantitative data on calcification from 26 calcifying cultures enabled a first broad comparison of Symbiodinium-induced bacterial-algal calcification with other calcification processes. Our findings support the idea that symbiolite formation is a typical, photosynthesis-induced, bacterial-algal calcification process that is likely to occur under natural conditions.}, }
@article {pmid29891919, year = {2018}, author = {Balvín, O and Roth, S and Talbot, B and Reinhardt, K}, title = {Co-speciation in bedbug Wolbachia parallel the pattern in nematode hosts.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {8797}, pmid = {29891919}, issn = {2045-2322}, mesh = {Animals ; Bedbugs/*microbiology ; Biosynthetic Pathways/genetics ; Biotin/biosynthesis ; *Genetic Speciation ; *Symbiosis ; Wolbachia/*classification/genetics/*isolation &amp; purification/metabolism ; }, abstract = {Wolbachia bacteria, vertically transmitted intracellular endosymbionts, are associated with two major host taxa in which they show strikingly different symbiotic modes. In some taxa of filarial nematodes, where Wolbachia are strictly obligately beneficial to the host, they show complete within- and among-species prevalence as well as co-phylogeny with their hosts. In arthropods, Wolbachia usually are parasitic; if beneficial effects occurs, they can be facultative or obligate, related to host reproduction. In arthropods, the prevalence of Wolbachia varies within and among taxa, and no co-speciation events are known. However, one arthropod species, the common bedbug Cimex lectularius was recently found to be dependent on the provision of biotin and riboflavin by Wolbachia, representing a unique case of Wolbachia providing nutritional and obligate benefits to an arthropod host, perhaps even in a mutualistic manner. Using the presence of presumably functional biotin gene copies, our study demonstrates that the obligate relationship is maintained at least in 10 out of 15 species of the genera Cimex and Paracimex. The remaining five species harboured Wolbachia as well, demonstrating the first known case of 100% prevalence of Wolbachia among higher arthropod taxa. Moreover, we show the predicted co-cladogenesis between Wolbachia and their bedbug hosts, also as the first described case of Wolbachia co-speciation in arthropods.}, }
@article {pmid29890648, year = {2018}, author = {Badawi, M and Moumen, B and Giraud, I and Grève, P and Cordaux, R}, title = {Investigating the Molecular Genetic Basis of Cytoplasmic Sex Determination Caused by Wolbachia Endosymbionts in Terrestrial Isopods.}, journal = {Genes}, volume = {9}, number = {6}, pages = {}, pmid = {29890648}, issn = {2073-4425}, abstract = {In animals, sexual differences between males and females are usually determined by sex chromosomes. Alternatively, sex may also be determined by vertically transmitted intracellular microbial endosymbionts. The best known cytoplasmic sex manipulative endosymbiont is Wolbachia which can, for instance, feminize genetic males into phenotypic females in the terrestrial isopod Armadillidium vulgare. However, the molecular genetic basis of cytoplasmic sex determination is unknown. To identify candidate genes of feminization induced by Wolbachia strain wVulC from A. vulgare, we sequenced the genome of Wolbachia strain wCon from Cylisticus convexus, the most closely related known Wolbachia strain to wVulC that does not induce feminization, and compared it to the wVulC genome. Then, we performed gene expression profiling of the 216 resulting wVulC candidate genes throughout host developmental stages in A. vulgare and the heterologous host C. convexus. We identified a set of 35 feminization candidate genes showing differential expression during host sexual development. Interestingly, 27 of the 35 genes are present in the f element, which is a piece of a feminizing Wolbachia genome horizontally transferred into the nuclear genome of A. vulgare and involved in female sex determination. Assuming that the molecular genetic basis of feminization by Wolbachia and the f element is the same, the 27 genes are candidates for acting as master sex determination genes in A. vulgare females carrying the f element.}, }
@article {pmid29880910, year = {2018}, author = {Yurchenko, T and Ševčíková, T and Přibyl, P and El Karkouri, K and Klimeš, V and Amaral, R and Zbránková, V and Kim, E and Raoult, D and Santos, LMA and Eliáš, M}, title = {A gene transfer event suggests a long-term partnership between eustigmatophyte algae and a novel lineage of endosymbiotic bacteria.}, journal = {The ISME journal}, volume = {12}, number = {9}, pages = {2163-2175}, pmid = {29880910}, issn = {1751-7370}, mesh = {*Gene Transfer, Horizontal ; Genomics ; Operon ; Rickettsiaceae/*genetics ; Stramenopiles/*microbiology ; Symbiosis ; }, abstract = {Rickettsiales are obligate intracellular bacteria originally found in metazoans, but more recently recognized as widespread endosymbionts of various protists. One genus was detected also in several green algae, but reports on rickettsialean endosymbionts in other algal groups are lacking. Here we show that several distantly related eustigmatophytes (coccoid algae belonging to Ochrophyta, Stramenopiles) are infected by Candidatus Phycorickettsia gen. nov., a new member of the family Rickettsiaceae. The genome sequence of Ca. Phycorickettsia trachydisci sp. nov., an endosymbiont of Trachydiscus minutus CCALA 838, revealed genomic features (size, GC content, number of genes) typical for other Rickettsiales, but some unusual aspects of the gene content were noted. Specifically, Phycorickettsia lacks genes for several components of the respiration chain, haem biosynthesis pathway, or c-di-GMP-based signalling. On the other hand, it uniquely harbours a six-gene operon of enigmatic function that we recently reported from plastid genomes of two distantly related eustigmatophytes and from various non-rickettsialean bacteria. Strikingly, the eustigmatophyte operon is closely related to the one from Phycorickettsia, suggesting a gene transfer event between the endosymbiont and host lineages in early eustigmatophyte evolution. We hypothesize an important role of the operon in the physiology of Phycorickettsia infection and a long-term eustigmatophyte-Phycorickettsia coexistence.}, }
@article {pmid29876068, year = {2018}, author = {Zhang, L and Yun, Y and Hu, G and Peng, Y}, title = {Insights into the bacterial symbiont diversity in spiders.}, journal = {Ecology and evolution}, volume = {8}, number = {10}, pages = {4899-4906}, pmid = {29876068}, issn = {2045-7758}, abstract = {Most spiders are natural enemies of pests, and it is beneficial for the biological control of pests to learn the relationships between symbionts and their spider hosts. Research on the bacterial communities of insects has been conducted recently, but only a few studies have addressed the bacterial communities of spiders. To obtain a complete overview of the microbial communities of spiders, we examined eight species of spider (Pirata subpiraticus, Agelena difficilis, Artema atlanta, Nurscia albofasciata, Agelena labyrinthica, Ummeliata insecticeps, Dictis striatipes, and Hylyphantes graminicola) with high-throughput sequencing based on the V3 and V4 regions of the 16S rRNA gene. The bacterial communities of the spider samples were dominated by five types of endosymbionts, Wolbachia, Cardinium, Rickettsia, Spiroplasma, and Rickettsiella. The dominant OTUs (operational taxonomic units) from each of the five endosymbionts were analyzed, and the results showed that different spider species were usually dominated by special OTUs. In addition to endosymbionts, Pseudomonas, Sphingomonas, Acinetobacter, Novosphingobium, Aquabacterium, Methylobacterium, Brevundimonas, Rhizobium, Bradyrhizobium, Citrobacter, Arthrobacter, Pseudonocardia, Microbacterium, Lactobacillus, and Lactococcus were detected in spider samples in our study. Moreover, the abundance of Sphingomonas, Methylobacterium, Brevundimonas, and Rhizobium in the spider D. striatipes was significantly higher (p < .05) than the bacterial abundance of these species in seven other spider species. These findings suggest that same as in insects, co-infection of multiple types of endosymbionts is common in the hosts of the Araneae order, and other bacterial taxa also exist in spiders besides the endosymbionts.}, }
@article {pmid29873141, year = {2019}, author = {Vďačný, P and Rajter, &#x13d; and Stoeck, T and Foissner, W}, title = {A Proposed Timescale for the Evolution of Armophorean Ciliates: Clevelandellids Diversify More Rapidly Than Metopids.}, journal = {The Journal of eukaryotic microbiology}, volume = {66}, number = {1}, pages = {167-181}, doi = {10.1111/jeu.12641}, pmid = {29873141}, issn = {1550-7408}, mesh = {*Biological Evolution ; Ciliophora/*classification/physiology ; Phylogeny ; *Symbiosis ; }, abstract = {Members of the class Armophorea occur in microaerophilic and anaerobic habitats, including the digestive tract of invertebrates and vertebrates. Phylogenetic kinships of metopid and clevelandellid armophoreans conflict with traditional morphology-based classifications. To reconcile their relationships and understand their morphological evolution and diversification, we utilized the molecular clock theory as well as information contained in the estimated time trees and morphology of extant taxa. The radiation of the last common ancestor of metopids and clevelandellids very likely occurred during the Paleozoic and crown diversification of the endosymbiotic clevelandellids dates back to the Mesozoic. According to diversification analyses, endosymbiotic clevelandellids have higher net diversification rates than predominantly free-living metopids. Their cladogenic success was very likely associated with sharply isolated ecological niches constituted by their hosts. Conflicts between traditional classifications and molecular phylogenies of metopids and clevelandellids very likely come from processes, leading to further diversification without extinction of ancestral lineages as well as from morphological plesiomorphies incorrectly classified as apomorphies. Our study thus suggests that diversification processes and reconstruction of ancestral morphologies improve the understanding of paraphyly which occurs in groups of organisms with an apparently long evolutionary history and when speciation prevails over extinction.}, }
@article {pmid29871803, year = {2018}, author = {Heddi, A and Zaidman-Rémy, A}, title = {Endosymbiosis as a source of immune innovation.}, journal = {Comptes rendus biologies}, volume = {341}, number = {5}, pages = {290-296}, doi = {10.1016/j.crvi.2018.03.005}, pmid = {29871803}, issn = {1768-3238}, mesh = {Animals ; *Biological Evolution ; Insecta/*physiology ; Symbiosis/*immunology ; }, abstract = {Some years ago, Lynn Margulis proposed to envision symbiosis as a source of evolutionary innovation. Here we revisit this concept in the context of insect nutritional endosymbiosis, and discuss recent data suggesting that host-endosymbiont coevolution has led to the selection of innovative strategies towards endosymbiont maintenance and control by the host immune system.}, }
@article {pmid29868291, year = {2018}, author = {Li, J and Wang, N and Liu, Y and Qiu, S}, title = {Proteomics of Nasonia vitripennis and the effects of native Wolbachia infection on N. vitripennis.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4905}, pmid = {29868291}, issn = {2167-8359}, abstract = {BACKGROUND: Nasonia vitripennis, a parasitic wasp, is a good model organism to study developmental and evolutionary genetics and to evaluate the interactions between insect hosts and their symbionts. Wolbachia may be the most prevalent endosymbiont among insect species due to their special ability to improve the fitness of the infected hosts. Transinfection of bacteria or fungi could substantially alter the expression of host immune system components. However, few studies have focused on the effects of native Wolbachia infection. Accordingly, in this study, we evaluated the proteomics of N. vitripennis following Wolbachia infection.<br><br>METHODS: We studied the proteomics of N. vitripennis following native Wolbachia infection and in antibiotic-treated Wolbachia-free samples using isobaric tags for relative and absolute quantification-liquid chromatography tandem mass spectrometry, accompanying with some ecological experiments.<br><br>RESULTS: In total, 3,096 proteins were found to be associated with a wide range of biological processes, molecular functions, and cellular components. Interestingly, there were few significant changes in immune or reproductive proteins between samples with and without Wolbachia infection. Differentially expressed proteins were involved in the binding process, catalytic activity, and the metabolic process, as confirmed by quantitative reverse transcription polymerase chain reaction.<br><br>DISCUSSION: Invasion of any pathogen or bacterium within a short time can cause an immunoreaction in the host. Our results implied that during the long process of coexistence, the immune system of the host was not as sensitive as when the symbiont initially infected the host, implying that the organisms had gradually adjusted to cohabitation.}, }
@article {pmid29860608, year = {2018}, author = {Dearth, SP and Castro, HF and Venice, F and Tague, ED and Novero, M and Bonfante, P and Campagna, SR}, title = {Metabolome changes are induced in the arbuscular mycorrhizal fungus Gigaspora margarita by germination and by its bacterial endosymbiont.}, journal = {Mycorrhiza}, volume = {28}, number = {5-6}, pages = {421-433}, pmid = {29860608}, issn = {1432-1890}, mesh = {Bacteria/*growth &amp; development ; Chromatography, High Pressure Liquid ; Mass Spectrometry ; Metabolic Networks and Pathways ; Metabolome ; Metabolomics/*methods ; Mycorrhizae/metabolism/*physiology ; Spores, Fungal/metabolism/physiology ; Symbiosis ; }, abstract = {Metabolomic profiling is becoming an increasingly important technique in the larger field of systems biology by allowing the simultaneous measurement of thousands of small molecules participating in and resulting from cellular reactions. In this way, metabolomics presents an opportunity to observe the physiological state of a system, which may provide the ability to monitor the whole of cellular metabolism as the technology progresses. The arbuscular mycorrhizal fungus Gigaspora margarita has not previously been explored with regard to metabolite composition. To develop a better understanding of G. margarita and the influences of its endosymbiont Candidatus Glomeribacter gigasporarum, a metabolomic analysis was applied to quiescent and germinated spores with and without endobacteria. Over 100 metabolites were identified and greater than 2600 unique unidentified spectral features were observed. Multivariate analysis of the metabolomes was performed, and a differentiation between all metabolic states of spores and spores hosting the endobacteria was observed. The known metabolites were recruited to many biochemical pathways, with many being involved in maintenance of the antioxidant potential, tyrosine metabolism, and melanin production. Each of the pathways had higher metabolite abundances in the presence of the endosymbiont. These metabolomics data also agree with previously reported transcriptomics results demonstrating the capability of this technique to confirm hypotheses and showing the feasibility of multi-omic approaches for the study of arbuscular mycorrhizal fungi and their endobacterial communities. Challenges still exist in metabolomic analysis, e.g., the identification of compounds is demanding due to incomplete libraries. A metabolomics technique to probe the effects of bacterial endosymbionts on fungal physiology is presented herein, and this method is useful for hypothesis generation as well as testing as noted above.}, }
@article {pmid29860351, year = {2018}, author = {Wong, DK and Grisdale, CJ and Fast, NM}, title = {Evolution and Diversity of Pre-mRNA Splicing in Highly Reduced Nucleomorph Genomes.}, journal = {Genome biology and evolution}, volume = {10}, number = {6}, pages = {1573-1583}, pmid = {29860351}, issn = {1759-6653}, mesh = {Cell Nucleus/*genetics ; Cercozoa/genetics ; Chlorophyta/genetics ; Cryptophyta/genetics ; Eukaryota/genetics ; Evolution, Molecular ; Gene Regulatory Networks/genetics ; Genetic Variation/*genetics ; Genome/*genetics ; Introns/genetics ; Plastids/genetics ; RNA Precursors/*genetics ; RNA Splicing/*genetics ; RNA, Antisense/genetics ; Transcription, Genetic/genetics ; Transcriptome/genetics ; }, abstract = {Eukaryotic genes are interrupted by introns that are removed in a conserved process known as pre-mRNA splicing. Though well-studied in select model organisms, we are only beginning to understand the variation and diversity of this process across the tree of eukaryotes. We explored pre-mRNA splicing and other features of transcription in nucleomorphs, the highly reduced remnant nuclei of secondary endosymbionts. Strand-specific transcriptomes were sequenced from the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans, whose plastids are derived from red and green algae, respectively. Both organisms exhibited elevated nucleomorph antisense transcription and gene expression relative to their respective nuclei, suggesting unique properties of gene regulation and transcriptional control in nucleomorphs. Marked differences in splicing were observed between the two nucleomorphs: the few introns of the G. theta nucleomorph were largely retained in mature transcripts, whereas the many short introns of the B. natans nucleomorph are spliced at typical eukaryotic levels (>90%). These differences in splicing levels could be reflecting the ancestries of the respective plastids, the different intron densities due to independent genome reduction events, or a combination of both. In addition to extending our understanding of the diversity of pre-mRNA splicing across eukaryotes, our study also indicates potential links between splicing, antisense transcription, and gene regulation in reduced genomes.}, }
@article {pmid29860278, year = {2018}, author = {Kinjo, Y and Bourguignon, T and Tong, KJ and Kuwahara, H and Lim, SJ and Yoon, KB and Shigenobu, S and Park, YC and Nalepa, CA and Hongoh, Y and Ohkuma, M and Lo, N and Tokuda, G}, title = {Parallel and Gradual Genome Erosion in the Blattabacterium Endosymbionts of Mastotermes darwiniensis and Cryptocercus Wood Roaches.}, journal = {Genome biology and evolution}, volume = {10}, number = {6}, pages = {1622-1630}, pmid = {29860278}, issn = {1759-6653}, mesh = {Animals ; Cockroaches/*genetics ; Flavobacteriaceae/*genetics ; Genome, Bacterial/*genetics ; Isoptera/*microbiology ; Phylogeny ; Symbiosis/*genetics ; Wood/*microbiology ; }, abstract = {Almost all examined cockroaches harbor an obligate intracellular endosymbiont, Blattabacterium cuenoti. On the basis of genome content, Blattabacterium has been inferred to recycle nitrogen wastes and provide amino acids and cofactors for its hosts. Most Blattabacterium strains sequenced to date harbor a genome of ∼630 kbp, with the exception of the termite Mastotermes darwiniensis (∼590 kbp) and Cryptocercus punctulatus (∼614 kbp), a representative of the sister group of termites. Such genome reduction may have led to the ultimate loss of Blattabacterium in all termites other than Mastotermes. In this study, we sequenced 11 new Blattabacterium genomes from three species of Cryptocercus in order to shed light on the genomic evolution of Blattabacterium in termites and Cryptocercus. All genomes of Cryptocercus-derived Blattabacterium genomes were reduced (∼614 kbp), except for that associated with Cryptocercus kyebangensis, which comprised 637 kbp. Phylogenetic analysis of these genomes and their content indicates that Blattabacterium experienced parallel genome reduction in Mastotermes and Cryptocercus, possibly due to similar selective forces. We found evidence of ongoing genome reduction in Blattabacterium from three lineages of the C. punctulatus species complex, which independently lost one cysteine biosynthetic gene. We also sequenced the genome of the Blattabacterium associated with Salganea taiwanensis, a subsocial xylophagous cockroach that does not vertically transmit gut symbionts via proctodeal trophallaxis. This genome was 632 kbp, typical of that of nonsubsocial cockroaches. Overall, our results show that genome reduction occurred on multiple occasions in Blattabacterium, and is still ongoing, possibly because of new associations with gut symbionts in some lineages.}, }
@article {pmid29858203, year = {2018}, author = {Almeida, C and Silva Pereira, C and Gonzalez-Menendez, V and Bills, G and Pascual, J and Sánchez-Hidalgo, M and Kehraus, S and Genilloud, O}, title = {Unveiling Concealed Functions of Endosymbiotic Bacteria Harbored in the Ascomycete Stachylidium bicolor.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {15}, pages = {}, pmid = {29858203}, issn = {1098-5336}, mesh = {Ascomycota/chemistry/growth &amp; development/*physiology ; Burkholderia/genetics/isolation &amp; purification/*physiology ; Mycelium/chemistry/physiology ; Peptides, Cyclic/metabolism ; Sphingomonas/genetics/isolation &amp; purification/*physiology ; Spores, Fungal/growth &amp; development/physiology ; *Symbiosis ; }, abstract = {Among the plethora of unusual secondary metabolites isolated from Stachylidium bicolor are the tetrapeptidic endolides A and B. Both tetrapeptides contain 3-(3-furyl)-alanine residues, previously proposed to originate from bacterial metabolism. Inspired by this observation, we aimed to identify the presence of endosymbiotic bacteria in S. bicolor and to discover the true producer of the endolides. The endobacterium Burkholderia contaminans was initially detected by 16S rRNA gene amplicon sequencing from the fungal metagenome and was subsequently isolated. It was confirmed that the tetrapeptides were produced by the axenic B. contaminans only when in latency. Fungal colonies unable to produce conidia and the tetrapeptides were isolated and confirmed to be free of B. contaminans A second endosymbiont identified as related to Sphingomonas leidyi was also isolated. In situ imaging of the mycelium supported an endosymbiotic relationship between S. bicolor and the two endobacteria. Besides the technical novelty, our in situ analyses revealed that the two endobacteria are compartmentalized in defined fungal cells, prevailing mostly in latency when in symbiosis. Within the emerging field of intracellular bacterial symbioses, fungi are the least studied eukaryotic hosts. Our study further supports the Fungi as a valuable model for understanding endobacterial symbioses in eukaryotes.IMPORTANCE The discovery of two bacterial endosymbionts harbored in Stachylidium bicolor mycelium, Burkholderia contaminans and Sphingomonas leidyi, is described here. Production of tetrapeptides inside the mycelium is ensured by B. contaminans, and fungal sporulation is influenced by the endosymbionts. Here, we illustrate the bacterial endosymbiotic origin of secondary metabolites in an Ascomycota host.}, }
@article {pmid29857577, year = {2018}, author = {Sinotte, VM and Freedman, SN and Ugelvig, LV and Seid, MA}, title = {Camponotusfloridanus Ants Incur a Trade-Off between Phenotypic Development and Pathogen Susceptibility from Their Mutualistic Endosymbiont Blochmannia.}, journal = {Insects}, volume = {9}, number = {2}, pages = {}, pmid = {29857577}, issn = {2075-4450}, abstract = {Various insects engage in microbial mutualisms in which the reciprocal benefits exceed the costs. Ants of the genus Camponotus benefit from nutrient supplementation by their mutualistic endosymbiotic bacteria, Blochmannia, but suffer a cost in tolerating and regulating the symbiont. This cost suggests that the ants face secondary consequences such as susceptibility to pathogenic infection and transmission. In order to elucidate the symbiont's effects on development and disease defence, Blochmannia floridanus was reduced in colonies of Camponotus floridanus using antibiotics. Colonies with reduced symbiont levels exhibited workers of smaller body size, smaller colony size, and a lower major-to-minor worker caste ratio, indicating the symbiont's crucial role in development. Moreover, these ants had decreased cuticular melanisation, yet higher resistance to the entomopathogen Metarhizium brunneum, suggesting that the symbiont reduces the ants' ability to fight infection, despite the availability of melanin to aid in mounting an immune response. While the benefits of improved growth and development likely drive the mutualism, the symbiont imposes a critical trade-off. The ants' increased susceptibility to infection exacerbates the danger of pathogen transmission, a significant risk given ants' social lifestyle. Thus, the results warrant research into potential adaptations of the ants and pathogens that remedy and exploit the described disease vulnerability.}, }
@article {pmid29851312, year = {2018}, author = {Dahmani, M and Tahir, D and Cabre, O and Raoult, D and Fenollar, F and Davoust, B and Mediannikov, O}, title = {Prevalence of Anaplasmataceae and Filariidae species in unowned and military dogs in New Caledonia.}, journal = {Veterinary medicine and science}, volume = {4}, number = {2}, pages = {140-149}, pmid = {29851312}, issn = {2053-1095}, mesh = {Anaplasmataceae/physiology ; Anaplasmataceae Infections/epidemiology/parasitology/*veterinary ; Animals ; Dog Diseases/*epidemiology/parasitology ; Dogs ; Female ; Filariasis/epidemiology/parasitology/*veterinary ; Filarioidea/physiology ; Male ; Military Personnel ; New Caledonia/epidemiology ; Ownership ; Prevalence ; }, abstract = {Dogs are competent reservoir hosts of several zoonotic agents, including Filariidae nematodes and Anaplasmataceae family bacteria. The latter family unites human and veterinary pathogens (Anaplasma, Ehrlichia and Neorickettsia bacteria) with Wolbachia, some of which are obligatory endosymbionts of pathogenic filarial nematodes. The epidemiology of Anaplasmataceae and Filariidae species infecting dogs living in kennels in New Caledonia was studied. 64 EDTA blood samples were screened for the presence of Anaplasmataceae and filarial nematodes. Molecular study was conducted using primers and probe targeting the of 23S rRNA long fragment of Anaplasmataceae species. Next, all blood sample was screened for the presence of Filariidae species targeting the primers and probe targeting the COI gene, as well as primers targeting the COI and 5S rRNA genes of all filarial worms. Anaplasma platys was identified in 8/64 (12.5, 95% confidence interval [CI]: 4.4-20.6%) and Wolbachia endosymbiont of Dirofilaria immitis in 8/64 (12.5%, CI: 4.4-20.6%). Filariidae species investigation was performed and showed that 11/64 (17.2%, CI: 7.9-26.4%) dogs were infected with D. immitis, whereas, 2/64 (3.1%, CI: 0.0-7.3%) were infected with Acanthocheilonema reconditum. Finally, we checked the occurrence of co-infection between Anaplasmataceae and Filariidae species. Co-occurrence with Wolbachia endosymbiont of D. immitis was observed in seven dogs, one dog was co-infected with A. platys and A. reconditum and another was co-infected with Wolbachia endosymbiont of D. immitis and A. reconditum. These results are the first report of Anaplasmataceae and Filariidae occurring in dogs in New Caledonia.}, }
@article {pmid29851149, year = {2018}, author = {Ote, M and Yamamoto, D}, title = {The Wolbachia protein TomO interacts with a host RNA to induce polarization defects in Drosophila oocytes.}, journal = {Archives of insect biochemistry and physiology}, volume = {99}, number = {1}, pages = {e21475}, doi = {10.1002/arch.21475}, pmid = {29851149}, issn = {1520-6327}, mesh = {Animals ; Bacterial Proteins/*genetics/metabolism ; Body Patterning ; Drosophila simulans/*embryology/*microbiology ; Embryo, Nonmammalian/microbiology ; Embryonic Development ; Oocytes/growth &amp; development ; RNA/metabolism ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia is an endosymbiont prevalent in arthropods. To maximize its transmission thorough the female germline, Wolbachia induces in infected hosts male-to-female transformation, male killing, parthenogenesis, and cytoplasmic incompatibility, depending on the host species and Wolbachia strain involved. However, the molecular mechanisms underlying these host manipulations by Wolbachia remain largely unknown. The Wolbachia strain wMel, an inhabitant of Drosophila melanogaster, impairs host oogenesis only when transplanted into a heterologous host, for example, Drosophila simulans. We found that egg polarity defects induced by wMel infection in D. simulans can be recapitulated in the natural host D. melanogaster by transgenic overexpression of a variant of the Wolbachia protein Toxic manipulator of oogenesis (TomO), TomOwMel[∆HS] , in the female germline. RNA immunoprecipitation assays demonstrated that TomO physically associates with orb mRNA, which, as a result, fails to interact with the translation repressor Cup. This leads to precocious translation of Orb, a posterior determinant, and thereby to the misspecification of oocytes and accompanying polarity defects. We propose that the ability of TomO to bind to orb mRNA might provide a means for Wolbachia to enter the oocyte located at the posterior end of the egg chamber, thereby accomplishing secure maternal transmission thorough the female germline.}, }
@article {pmid29845544, year = {2018}, author = {O'Neill, SL}, title = {The Use of Wolbachia by the World Mosquito Program to Interrupt Transmission of Aedes aegypti Transmitted Viruses.}, journal = {Advances in experimental medicine and biology}, volume = {1062}, number = {}, pages = {355-360}, doi = {10.1007/978-981-10-8727-1_24}, pmid = {29845544}, issn = {0065-2598}, mesh = {Aedes/*microbiology/virology ; Animals ; Australia ; Humans ; Mosquito Control ; Mosquito Vectors/*microbiology/virology ; Virus Diseases/transmission/virology ; *Virus Physiological Phenomena ; Viruses/genetics ; Wolbachia/*physiology ; }, abstract = {The biological control of mosquito transmission by the use of the naturally occurring insect-specific bacterial endosymbiont Wolbachia has been successfully tested in small field trials. The approach has been translated successfully to larger field sites in Townsville, Australia and expanded to more than 10 countries through the Eliminate Dengue Program. The broader application of the program beyond limiting the transmission of dengue and including other Aedes aegypti borne mosquitoes has seen the program growing into a global not-for-profit initiative to be known as the World Mosquito Program.}, }
@article {pmid29844969, year = {2018}, author = {Hume, BCC and Ziegler, M and Poulain, J and Pochon, X and Romac, S and Boissin, E and de Vargas, C and Planes, S and Wincker, P and Voolstra, CR}, title = {An improved primer set and amplification protocol with increased specificity and sensitivity targeting the Symbiodinium ITS2 region.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4816}, pmid = {29844969}, issn = {2167-8359}, abstract = {The Internal Transcribed Spacer 2 (ITS2) rRNA gene is a commonly targeted genetic marker to assess diversity of Symbiodinium, a dinoflagellate genus of algal endosymbionts that is pervasively associated with marine invertebrates, and notably reef-building corals. Here we tested three commonly used ITS2 primer pairs (SYM_VAR_5.8S2/SYM_VAR_REV, ITSintfor2/ITSReverse, and ITS-DINO/ITS2Rev2) with regard to amplification specificity and sensitivity towards Symbiodinium, as well as sub-genera taxonomic bias. We tested these primers over a range of sample types including three coral species, coral surrounding water, reef surface water, and open ocean water to assess their suitability for use in large-scale next generation sequencing projects and to develop a standardised PCR protocol. We found the SYM_VAR_5.8S2/SYM_VAR_REV primers to perform superior to the other tested ITS2 primers. We therefore used this primer pair to develop a standardised PCR protocol. To do this, we tested the effect of PCR-to-PCR variation, annealing temperature, cycle number, and different polymerase systems on the PCR efficacy. The Symbiodinium ITS2 PCR protocol developed here delivers improved specificity and sensitivity towards Symbiodinium with apparent minimal sub-genera taxonomic bias across all sample types. In particular, the protocol's ability to amplify Symbiodinium from a range of environmental sources will facilitate the study of Symbiodinium populations across biomes.}, }
@article {pmid29807401, year = {2018}, author = {Ali, H and Muhammad, A and Hou, Y}, title = {Infection Density Dynamics and Phylogeny of Wolbachia Associated with Coconut Hispine Beetle, Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), by Multilocus Sequence Type (MLST) Genotyping.}, journal = {Journal of microbiology and biotechnology}, volume = {28}, number = {5}, pages = {796-808}, doi = {10.4014/jmb.1712.12019}, pmid = {29807401}, issn = {1738-8872}, mesh = {Animals ; Bacterial Load/*genetics ; Coleoptera/*microbiology ; DNA, Bacterial/analysis/genetics ; Female ; Genotype ; Life Cycle Stages ; Male ; Multilocus Sequence Typing ; Real-Time Polymerase Chain Reaction ; *Rickettsiaceae Infections/microbiology/veterinary ; Symbiosis/*genetics ; *Wolbachia/genetics/physiology ; }, abstract = {The intracellular bacterium Wolbachia pipientis is widespread in arthropods. Recently, possibilities of novel Wolbachia-mediated hosts, their distribution, and natural rate have been anticipated, and the coconut leaf beetle Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae), which has garnered attention as a serious pest of palms, was subjected to this interrogation. By adopting Wolbachia surface protein (wsp) and multilocus sequence type (MLST) genotypic systems, we determined the Wolbachia infection density within host developmental stages, body parts, and tissues, and the results revealed that all the tested samples of B. longissima were infected with the same Wolbachia strain (wLog), suggesting complete vertical transmission. The MLST profile elucidated two new alleles (ftsZ-234 and coxA-266) that define a new sequence type (ST-483), which indicates the particular genotypic association of B. longissima and Wolbachia. The quantitative real-time PCR analysis revealed a higher infection density in the eggs and adult stage, followed by the abdomen and reproductive tissues, respectively. However, no significant differences were observed in the infection density between sexes. Moreover, the wsp and concatenated MLST alignment analysis of this study with other known Wolbachia-mediated arthropods revealed similar clustering with distinct monophyletic supergroup B. This is the first comprehensive report on the prevalence, infection dynamics, and phylogeny of the Wolbachia endosymbiont in B. longissima, which demonstrated that Wolbachia is ubiquitous across all developmental stages and distributed in the entire body of B. longissima. Understanding the Wolbachia infection dynamics would provide useful insight to build a framework for future investigations, understand its impacts on host physiology, and exploit it as a potential biocontrol agent.}, }
@article {pmid29803476, year = {2018}, author = {González-Escobar, JL and Grajales-Lagunes, A and Smoliński, A and Chagolla-López, A and De Léon-Rodríguez, A and Barba de la Rosa, AP}, title = {Microbiota of edible Liometopum apiculatum ant larvae reveals potential functions related to their nutritional value.}, journal = {Food research international (Ottawa, Ont.)}, volume = {109}, number = {}, pages = {497-505}, doi = {10.1016/j.foodres.2018.04.049}, pmid = {29803476}, issn = {1873-7145}, mesh = {Animals ; Ants/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Female ; Food Analysis/methods ; Host-Pathogen Interactions ; Larva/microbiology ; Male ; Metagenomics ; *Microbiota ; *Nutritive Value ; Ribotyping ; Symbiosis ; }, abstract = {Edible insects, due to their high nutritive value, are currently considered as a potential renewable source for food and feed production. Liometopum apiculatum ants are widely distributed in arid and semi-arid ecosystems and their larvae (escamoles) are considered as a delicacy, however the microbial importance in L. apiculatum nutritional ecology is unknown. The aim of this research was to characterize the microorganisms associated with both L. apiculatum larvae and the reproductive adult ants using the 16S rRNA gene sequencing and culturomics approaches. The obligate endosymbionts were also investigated through microscopic analysis. The most abundant Phylum identified by sequencing in the larvae was Firmicutes while in adult ants was Proteobacteria. Interestingly, the culturomics results showed 15 genera corresponding to the bacteria identified by sequencing analysis. Particularly, it was observed a large population of nitrogen-fixing bacteria, which could be linked with the high protein content in escamoles. Endosymbionts were detected in bacteoriocytes, these bacteria are related with vitamins and essential amino acids biosynthesis, and both compounds contributing to the high nutritional value of escamoles. This is the first report of the microorganisms present in the escamolera ant ensuring their safety as food and opening new areas of nutritional ecological and food processing.}, }
@article {pmid29802479, year = {2018}, author = {Boucias, DG and Zhou, Y and Huang, S and Keyhani, NO}, title = {Microbiota in insect fungal pathology.}, journal = {Applied microbiology and biotechnology}, volume = {102}, number = {14}, pages = {5873-5888}, doi = {10.1007/s00253-018-9089-z}, pmid = {29802479}, issn = {1432-0614}, mesh = {Animals ; Antibiosis/physiology ; Ascomycota/*physiology ; Host-Pathogen Interactions ; Insecta/*microbiology ; Microbiota/physiology ; }, abstract = {Significant progress has been made in the biochemical and genetic characterization of the host-pathogen interaction mediated by insect pathogenic fungi, with the most widely studied being the Ascomycetes (Hypocrealean) fungi, Metarhizium robertsii and Beauveria bassiana. However, few studies have examined the consequences and effects of host (insect) microbes, whether compatible or antagonistic, on the development and survival of entomopathogenic fungi. Host microbes can act on the insect cuticular surface, within the gut, in specialized insect microbe hosting structures, and within cells, and they include a wide array of facultative and/or obligate exosymbionts and endosymbionts. The insect microbiome differs across developmental stages and in response to nutrition (e.g., different plant hosts for herbivores) and environmental conditions, including exposure to chemical insecticides. Here, we review recent advances indicating that insect-pathogenic fungi have evolved a spectrum of strategies for exploiting or suppressing host microbes, including the production of antimicrobial compounds that are expressed at discrete stages of the infection process. Conversely, there is increasing evidence that some insects have acquired microbes that may be specialized in the production of antifungal compounds to combat infection by (entomopathogenic) fungi. Consideration of the insect microbiome in fungal insect pathology represents a new frontier that can help explain previously obscure ecological and pathological aspects of the biology of entomopathogenic fungi. Such information may lead to novel approaches to improving the efficacy of these organisms in pest control efforts.}, }
@article {pmid29802195, year = {2018}, author = {Mertens, J and Aliyu, H and Cowan, DA}, title = {LEA Proteins and the Evolution of the WHy Domain.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {15}, pages = {}, pmid = {29802195}, issn = {1098-5336}, mesh = {Bacteria/chemistry/classification/genetics/*metabolism ; Bacterial Proteins/*chemistry/genetics/metabolism ; *Evolution, Molecular ; Phylogeny ; Plant Proteins/chemistry/genetics/*metabolism ; Plants/chemistry/classification/genetics/*metabolism ; Protein Domains ; }, abstract = {The late embryogenesis abundant (LEA) family is composed of a diverse collection of multidomain and multifunctional proteins found in all three domains of the tree of life, but they are particularly common in plants. Most members of the family are known to play an important role in abiotic stress response and stress tolerance in plants but are also part of the plant hypersensitive response to pathogen infection. The mechanistic basis for LEA protein functionality is still poorly understood. The group of LEA 2 proteins harbor one or more copies of a unique domain, the water stress and hypersensitive response (WHy) domain. This domain sequence has recently been identified as a unique open reading frame (ORF) in some bacterial genomes (mostly in the phylum Firmicutes), and the recombinant bacterial WHy protein has been shown to exhibit a stress tolerance phenotype in Escherichia coli and an in vitro protein denaturation protective function. Multidomain phylogenetic analyses suggest that the WHy protein gene sequence may have ancestral origins in the domain Archaea, with subsequent acquisition in Bacteria and eukaryotes via endosymbiont or horizontal gene transfer mechanisms. Here, we review the structure, function, and nomenclature of LEA proteins, with a focus on the WHy domain as an integral component of the LEA constructs and as an independent protein.}, }
@article {pmid29802189, year = {2018}, author = {Zolfaghari Emameh, R and Barker, HR and Hytönen, VP and Parkkila, S}, title = {Involvement of β-Carbonic Anhydrase Genes in Bacterial Genomic Islands and Their Horizontal Transfer to Protists.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {15}, pages = {}, pmid = {29802189}, issn = {1098-5336}, mesh = {Amino Acid Sequence ; Bacteria/chemistry/classification/*enzymology/*genetics ; Bacterial Proteins/chemistry/*genetics/metabolism ; Carbonic Anhydrases/chemistry/*genetics/metabolism ; Chromosomes, Bacterial/genetics/metabolism ; Eukaryota/classification/enzymology/*genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; *Genomic Islands ; Phylogeny ; Plasmids/genetics/metabolism ; Sequence Alignment ; }, abstract = {Genomic islands (GIs) are a type of mobile genetic element (MGE) that are present in bacterial chromosomes. They consist of a cluster of genes that produce proteins that contribute to a variety of functions, including, but not limited to, the regulation of cell metabolism, antimicrobial resistance, pathogenicity, virulence, and resistance to heavy metals. The genes carried in MGEs can be used as a trait reservoir in times of adversity. Transfer of genes using MGEs, occurring outside reproduction, is called horizontal gene transfer (HGT). Previous data have shown that numerous HGT events have occurred through endosymbiosis between prokaryotes and eukaryotes. β-Carbonic anhydrase (β-CA) enzymes play a critical role in the biochemical pathways of many prokaryotes and eukaryotes. We previously suggested the horizontal transfer of β-CA genes from plasmids of some prokaryotic endosymbionts to their protozoan hosts. In this study, we set out to identify β-CA genes that might have been transferred between prokaryotic and protist species through HGT in GIs. Therefore, we investigated prokaryotic chromosomes containing β-CA-encoding GIs and utilized multiple bioinformatics tools to reveal the distinct movements of β-CA genes among a wide variety of organisms. Our results identify the presence of β-CA genes in GIs of several medically and industrially relevant bacterial species, and phylogenetic analyses reveal multiple cases of likely horizontal transfer of β-CA genes from GIs of ancestral prokaryotes to protists.IMPORTANCE The evolutionary process is mediated by mobile genetic elements (MGEs), such as genomic islands (GIs). A gene or set of genes in the GIs is exchanged between and within various species through horizontal gene transfer (HGT). Based on the crucial role that GIs can play in bacterial survival and proliferation, they were introduced as environment- and pathogen-associated factors. Carbonic anhydrases (CAs) are involved in many critical biochemical pathways, such as the regulation of pH homeostasis and electrolyte transfer. Among the six evolutionary families of CAs, β-CA gene sequences are present in many bacterial species, which can be horizontally transferred to protists during evolution. This study shows the involvement of bacterial β-CA gene sequences in the GIs and suggests their horizontal transfer to protists during evolution.}, }
@article {pmid29797769, year = {2018}, author = {Beinart, RA and Rotterová, J and Čepička, I and Gast, RJ and Edgcomb, VP}, title = {The genome of an endosymbiotic methanogen is very similar to those of its free-living relatives.}, journal = {Environmental microbiology}, volume = {20}, number = {7}, pages = {2538-2551}, doi = {10.1111/1462-2920.14279}, pmid = {29797769}, issn = {1462-2920}, mesh = {Animals ; Base Composition ; Ciliophora/*microbiology ; Euryarchaeota/*genetics ; *Genome, Bacterial ; Phylogeny ; Symbiosis ; }, abstract = {The methanogenic endosymbionts of anaerobic protists represent the only known intracellular archaea, yet, almost nothing is known about genome structure and content in these lineages. Here, an almost complete genome of an intracellular Methanobacterium species was assembled from a metagenome derived from its host ciliate, a Heterometopus species. Phylogenomic analysis showed that the endosymbiont was closely related to free-living Methanobacterium isolates, and when compared with the genomes of free-living Methanobacterium, the endosymbiont did not show significant reduction in genome size or GC content. Additionally, the Methanobacterium endosymbiont genome shared the majority of its genes with its closest relative, though it did also contain unique genes possibly involved in interactions with the host via membrane-associated proteins, the removal of toxic by-products from host metabolism and the production of small signalling molecules. Though anaerobic ciliates have been shown to transmit their endosymbionts to daughter cells during division, the results presented here could suggest that the endosymbiotic Methanobacterium did not experience significant genetic isolation or drift and/or that this lineage was only recently acquired. Altogether, comparative genomic analysis identified genes potentially involved in the establishment and maintenance of the symbiosis, as well provided insight into the genomic consequences for an intracellular archaeum.}, }
@article {pmid29797656, year = {2020}, author = {Leybourne, DJ and Bos, JIB and Valentine, TA and Karley, AJ}, title = {The price of protection: a defensive endosymbiont impairs nymph growth in the bird cherry-oat aphid, Rhopalosiphum padi.}, journal = {Insect science}, volume = {27}, number = {1}, pages = {69-85}, pmid = {29797656}, issn = {1744-7917}, mesh = {Animals ; Aphids/genetics/growth &amp; development/*microbiology ; Enterobacteriaceae/*physiology ; Genotype ; Nymph/genetics/growth &amp; development/microbiology ; Scotland ; *Symbiosis ; }, abstract = {Bacterial endosymbionts have enabled aphids to adapt to a range of stressors, but their effects in many aphid species remain to be established. The bird cherry-oat aphid, Rhopalosiphum padi (Linnaeus), is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria, although the resulting aphid phenotype has not been described. This study presents the first report of R. padi infection with the facultative bacterial endosymbiont Hamiltonella defensa. Individuals of R. padi were sampled from populations in Eastern Scotland, UK, and shown to represent seven R. padi genotypes based on the size of polymorphic microsatellite markers; two of these genotypes harbored H. defensa. In parasitism assays, survival of H. defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani (Viereck) was 5 fold higher than for uninfected nymphs. Aphid genotype was a major determinant of aphid performance on two Hordeum species, a modern cultivar of barley H. vulgare and a wild relative H. spontaneum, although aphids infected with H. defensa showed 16% lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals. These findings suggest that deploying resistance traits in barley will favor the fittest R. padi genotypes, but symbiont-infected individuals will be favored when parasitoids are abundant, although these aphids will not achieve optimal performance on a poor quality host plant.}, }
@article {pmid29794009, year = {2018}, author = {Bakovic, V and Schebeck, M and Telschow, A and Stauffer, C and Schuler, H}, title = {Spatial spread of Wolbachia in Rhagoletis cerasi populations.}, journal = {Biology letters}, volume = {14}, number = {5}, pages = {}, pmid = {29794009}, issn = {1744-957X}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Czech Republic ; Hungary ; *Spatial Analysis ; Tephritidae/*microbiology ; Wolbachia/*physiology ; }, abstract = {The bacterial endosymbiont Wolbachia has been used to control insect pests owing to its ability to manipulate their life history and suppress infectious diseases. Therefore, knowledge on Wolbachia dynamics in natural populations is fundamental. The European cherry fruit fly, Rhagoletis cerasi, is infected with the Wolbachia strain wCer2, mainly present in southern and central European populations, and is currently spreading into wCer2-uninfected populations driven by high unidirectional cytoplasmic incompatibility. Here, we describe the distribution of wCer2 along two transition zones where the infection is spreading into wCer2-uninfected R. cerasi populations. Fine-scale sampling of 19 populations in the Czech Republic showed a smooth decrease of wCer2 frequency from south to north within a distance of less than 20 km. Sampling of 12 Hungarian populations, however, showed a sharp decline of wCer2 infection frequency within a few kilometres. We fitted a standard wave equation to our empirical data and estimated a Wolbachia wave speed of 1.9 km yr[-1] in the Czech Republic and 1.0 km yr[-1] in Hungary. Considering the univoltine life cycle and limited dispersal ability of R. cerasi, our study highlights a rapid Wolbachia spread in natural host populations.}, }
@article {pmid29779872, year = {2018}, author = {Funkhouser-Jones, LJ and van Opstal, EJ and Sharma, A and Bordenstein, SR}, title = {The Maternal Effect Gene Wds Controls Wolbachia Titer in Nasonia.}, journal = {Current biology : CB}, volume = {28}, number = {11}, pages = {1692-1702.e6}, pmid = {29779872}, issn = {1879-0445}, support = {R21 HD086833/HD/NICHD NIH HHS/United States ; P30 DK058404/DK/NIDDK NIH HHS/United States ; S10 OD021630/OD/NIH HHS/United States ; P30 EY008126/EY/NEI NIH HHS/United States ; P30 DK020593/DK/NIDDK NIH HHS/United States ; R01 AI132581/AI/NIAID NIH HHS/United States ; U24 DK059637/DK/NIDDK NIH HHS/United States ; P30 CA068485/CA/NCI NIH HHS/United States ; T32 GM008554/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Biological Evolution ; Insect Proteins/*genetics/metabolism ; Maternal Inheritance ; Quantitative Trait Loci/genetics ; Selection, Genetic ; Sequence Alignment ; Species Specificity ; Symbiosis/*genetics ; Wasps/*genetics/*microbiology ; Wolbachia/*physiology ; }, abstract = {Maternal transmission of intracellular microbes is pivotal in establishing long-term, intimate symbioses. For germline microbes that exert negative reproductive effects on their hosts, selection can theoretically favor the spread of host genes that counteract the microbe's harmful effects. Here, we leverage a major difference in bacterial (Wolbachia pipientis) titers between closely related wasp species with forward genetic, transcriptomic, and cytological approaches to map two quantitative trait loci that suppress bacterial titers via a maternal effect. Fine mapping and knockdown experiments identify the gene Wolbachia density suppressor (Wds), which dominantly suppresses bacterial transmission from mother to embryo. Wds evolved by lineage-specific non-synonymous changes driven by positive selection. Collectively, our findings demonstrate that a genetically simple change arose by positive Darwinian selection in less than a million years to regulate maternally transmitted bacteria via a dominant, maternal effect gene.}, }
@article {pmid29779502, year = {2018}, author = {Buysse, M and Duron, O}, title = {Multi-locus phylogenetics of the Midichloria endosymbionts reveals variable specificity of association with ticks.}, journal = {Parasitology}, volume = {145}, number = {14}, pages = {1969-1978}, doi = {10.1017/S0031182018000793}, pmid = {29779502}, issn = {1469-8161}, mesh = {Alphaproteobacteria/*classification ; Animals ; Bacterial Typing Techniques ; DNA, Bacterial/genetics ; Female ; Genetic Variation ; Host Specificity ; Ixodes/*microbiology ; Male ; Multilocus Sequence Typing ; *Phylogeny ; *Symbiosis ; }, abstract = {Candidatus Midichloria mitochondrii is a maternally inherited bacterium of ticks with a unique intra-mitochondrial lifestyle. Here, we investigate on the evolutionary history of these associations and the degree of Midichloria-tick specificity. While previous surveys used the 16S rRNA gene as an exclusive molecular marker, we rather developed a multi-locus typing method based on four more variable housekeeping genes (groEL, rpoB, dnaK and ftsZ) and on one flagellum gene (fliC) present in Midichloria genomes. Using this method, multi-locus phylogenetic analyses revealed the structuring of a wide Midichloria genetic diversity into three distinct lineages associated with ticks. Overall, two distinct evolutionary strategies are obvious depending on lineage: two Midichloria lineages are generalists with infections acquired through horizontal transfers between distantly related tick species but one other Midichloria lineage rather show a high specificity degree to the Ixodes tick genus. This pattern suggests a capacity of certain Midichloria strains to maintain infections in only limited range of related tick species. These different infection strategies of Midichloria highlight an unexpected variability in their dependency to their tick hosts. We further conjecture that this pattern is also likely to indicate variability in their effects on ticks.}, }
@article {pmid29779088, year = {2018}, author = {Thal, B and Braun, HP and Eubel, H}, title = {Proteomic analysis dissects the impact of nodulation and biological nitrogen fixation on Vicia faba root nodule physiology.}, journal = {Plant molecular biology}, volume = {97}, number = {3}, pages = {233-251}, pmid = {29779088}, issn = {1573-5028}, mesh = {Chromatography, Liquid/methods ; Nitrogen Fixation/*physiology ; Plant Proteins/isolation &amp; purification/metabolism/physiology ; Plant Root Nodulation/*physiology ; Plant Roots/metabolism/physiology ; Proteome ; Proteomics ; Rhizobium leguminosarum ; Root Nodules, Plant/metabolism/*physiology ; Symbiosis/physiology ; Tandem Mass Spectrometry/methods ; Vicia faba/metabolism/*physiology ; }, abstract = {Symbiotic nitrogen fixation in root nodules of legumes is a highly important biological process which is only poorly understood. Root nodule metabolism differs from that of roots. Differences in root and nodule metabolism are expressed by altered protein abundances and amenable to quantitative proteome analyses. Differences in the proteomes may either be tissue specific and related to the presence of temporary endosymbionts (the bacteroids) or related to nitrogen fixation activity. An experimental setup including WT bacterial strains and strains not able to conduct symbiotic nitrogen fixation as well as root controls enables identification of tissue and nitrogen fixation specific proteins. Root nodules are specialized plant organs housing and regulating the mutual symbiosis of legumes with nitrogen fixing rhizobia. As such, these organs fulfill unique functions in plant metabolism. Identifying the proteins required for the metabolic reactions of nitrogen fixation and those merely involved in sustaining the rhizobia:plant symbiosis, is a challenging task and requires an experimental setup which allows to differentiate between these two physiological processes. Here, quantitative proteome analyses of nitrogen fixing and non-nitrogen fixing nodules as well as fertilized and non-fertilized roots were performed using Vicia faba and Rhizobium leguminosarum. Pairwise comparisons revealed altered enzyme abundance between active and inactive nodules. Similarly, general differences between nodules and root tissue were observed. Together, these results allow distinguishing the proteins directly involved in nitrogen fixation from those related to nodulation. Further observations relate to the control of nodulation by hormones and provide supportive evidence for the previously reported correlation of nitrogen and sulfur fixation in these plant organs. Additionally, data on altered protein abundance relating to alanine metabolism imply that this amino acid may be exported from the symbiosomes of V. faba root nodules in addition to ammonia. Data are available via ProteomeXchange with identifier PXD008548.}, }
@article {pmid29776375, year = {2018}, author = {Kaufman, EL and Stone, NE and Scoles, GA and Hepp, CM and Busch, JD and Wagner, DM}, title = {Range-wide genetic analysis of Dermacentor variabilis and its Francisella-like endosymbionts demonstrates phylogeographic concordance between both taxa.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {306}, pmid = {29776375}, issn = {1756-3305}, support = {2010-65104-20386//National Institute of Food and Agriculture/International ; }, mesh = {Animals ; Arachnid Vectors/microbiology ; Canada ; Coxiella burnetii/genetics/pathogenicity ; DNA, Bacterial/genetics ; Dermacentor/classification/*genetics/*microbiology ; Disease Vectors ; Francisella/classification/*genetics/pathogenicity ; Genes, Mitochondrial/genetics ; Humans ; *Phylogeny ; Phylogeography ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/pathogenicity ; Sequence Analysis, DNA/methods ; Symbiosis/genetics ; United States ; }, abstract = {BACKGROUND: The American dog tick, Dermacentor variabilis, is an important vector of pathogens to humans, wildlife and domestic animals in North America. Although this tick species is widely distributed in the USA and Canada, knowledge of its range-wide phylogeographic patterns remains incomplete.<br><br>METHODS: We carried out a phylogenetic analysis of D. variabilis using samples collected from 26 USA states and five Canadian provinces. Tick samples (n = 1053 in total) originated from two main sources: existing archives (2000-2011), and new collections made from 2012 to 2013. We sequenced a 691 bp fragment of the cox1 gene from a subset (n = 332) of geographically diverse D. variabilis. DNA extracted from individual ticks (n = 1053) was also screened for a Francisella-like endosymbiont, using a targeted 16S rRNA sequencing approach, and important pathogens (Rickettsia spp. and Coxiella burnetii), using species-specific quantitative PCR assays.<br><br>RESULTS: Maximum parsimony analysis of cox1 sequences revealed two major groups within D. variabilis with distinct geographical distributions: one from the eastern USA/Canada (Group 1) and one from the west coast states of the USA (California and Washington; Group 2). However, genetic subdivisions within both of these two major groups were weak to moderate and not tightly correlated with geography. We found molecular signatures consistent with Francisella-like endosymbionts in 257 of the DNA extracts from the 1053 individual ticks, as well as Rickettsia spp. and Coxiella burnetii in a small number of ticks (n = 29 and 2, respectively). Phylogenetic patterns for Francisella-like endosymbionts, constructed using sequence data from the bacterial 16S rRNA locus, were similar to those for D. variabilis, with two major groups that had a nearly perfect one-to-one correlation with the two major groups within D. variabilis.<br><br>CONCLUSIONS: Our findings reveal a distinct phylogenetic split between the two major D. variabilis populations. However, high levels of genetic mixture among widely separated geographical localities occur within each of these two major groups. Furthermore, our phylogenetic analyses provide evidence of long-term tick-symbiont co-evolution. This work has implications for understanding the dispersal and evolutionary ecology of D. variabilis and associated vector-borne diseases.}, }
@article {pmid29771340, year = {2018}, author = {Schebeck, M and Feldkirchner, L and Marín, B and Krumböck, S and Schuler, H and Stauffer, C}, title = {Reproductive Manipulators in the Bark Beetle Pityogenes chalcographus (Coleoptera: Curculionidae)-The Role of Cardinium, Rickettsia, Spiroplasma, and Wolbachia.}, journal = {Journal of insect science (Online)}, volume = {18}, number = {3}, pages = {}, pmid = {29771340}, issn = {1536-2442}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Female ; Male ; Polymerase Chain Reaction ; Reproduction ; Rickettsia/*isolation &amp; purification ; Spiroplasma/*isolation &amp; purification ; *Symbiosis ; Weevils/*microbiology ; Wolbachia/*isolation &amp; purification ; }, abstract = {Heritable bacterial endosymbionts can alter the biology of numerous arthropods. They can influence the reproductive outcome of infected hosts, thus affecting the ecology and evolution of various arthropod species. The spruce bark beetle Pityogenes chalcographus (L.) (Coleoptera: Curculionidae: Scolytinae) was reported to express partial, unidirectional crossing incompatibilities among certain European populations. Knowledge on the background of these findings is lacking; however, bacterial endosymbionts have been assumed to manipulate the reproduction of this beetle. Previous work reported low-density and low-frequency Wolbachia infections of P. chalcographus but found it unlikely that this infection results in reproductive alterations. The aim of this study was to test the hypothesis of an endosymbiont-driven incompatibility, other than Wolbachia, reflected by an infection pattern on a wide geographic scale. We performed a polymerase chain reaction (PCR) screening of 226 individuals from 18 European populations for the presence of the endosymbionts Cardinium, Rickettsia, and Spiroplasma, and additionally screened these individuals for Wolbachia. Positive PCR products were sequenced to characterize these bacteria. Our study shows a low prevalence of these four endosymbionts in P. chalcographus. We detected a yet undescribed Spiroplasma strain in a single individual from Greece. This is the first time that this endosymbiont has been found in a bark beetle. Further, Wolbachia was detected in three beetles from two Scandinavian populations and two new Wolbachia strains were described. None of the individuals analyzed were infected with Cardinium and Rickettsia. The low prevalence of bacteria found here does not support the hypothesis of an endosymbiont-driven reproductive incompatibility in P. chalcographus.}, }
@article {pmid29769291, year = {2018}, author = {Kim, D and Minhas, BF and Li-Byarlay, H and Hansen, AK}, title = {Key Transport and Ammonia Recycling Genes Involved in Aphid Symbiosis Respond to Host-Plant Specialization.}, journal = {G3 (Bethesda, Md.)}, volume = {8}, number = {7}, pages = {2433-2443}, pmid = {29769291}, issn = {2160-1836}, mesh = {Ammonia/metabolism ; Animals ; Aphids/*genetics/metabolism ; Biological Transport ; Buchnera ; CpG Islands ; DNA Methylation ; Gene Expression Regulation ; Metabolic Networks and Pathways ; Symbiosis/*genetics ; }, abstract = {Microbes are known to influence insect-plant interactions; however, it is unclear if host-plant diet influences the regulation of nutritional insect symbioses. The pea aphid, Acyrthosiphon pisum, requires its nutritional endosymbiont, Buchnera, for the production of essential amino acids. We hypothesize that key aphid genes that regulate the nutritional symbioses respond to host-plant diet when aphids feed on a specialized (alfalfa) compared to a universal host-plant diet (fava), which vary in amino acid profiles. Using RNA-Seq and whole genome bisulfite sequencing, we measured gene expression and DNA methylation profiles for such genes when aphids fed on either their specialized or universal host-plant diets. Our results reveal that when aphids feed on their specialized host-plant they significantly up-regulate and/or hypo-methylate key aphid genes in bacteriocytes related to the amino acid metabolism, including glutamine synthetase in the GOGAT cycle that recycles ammonia into glutamine and the glutamine transporter ApGLNT1 Moreover, regardless of what host-plant aphids feed on we observed significant up-regulation and differential methylation of key genes involved in the amino acid metabolism and the glycine/serine metabolism, a metabolic program observed in proliferating cancer cells potentially to combat oxidative stress. Based on our results, we suggest that this regulatory response of key symbiosis genes in bacteriocytes allows aphids to feed on a suboptimal host-plant that they specialize on.}, }
@article {pmid29766491, year = {2018}, author = {Kriesner, P and Hoffmann, AA}, title = {Rapid spread of a Wolbachia infection that does not affect host reproduction in Drosophila simulans cage populations.}, journal = {Evolution; international journal of organic evolution}, volume = {}, number = {}, pages = {}, doi = {10.1111/evo.13506}, pmid = {29766491}, issn = {1558-5646}, abstract = {Wolbachia endosymbionts that are maternally inherited can spread rapidly in host populations through inducing sterility in uninfected females, but some Wolbachia infections do not influence host reproduction yet still persist. These infections are particularly interesting because they likely represent mutualistic endosymbionts, spreading by increasing host fitness. Here, we document such a spread in the wAu infection of Drosophila simulans. By establishing multiple replicate cage populations, we show that wAu consistently increased from an intermediate frequency to near fixation, representing an estimated fitness advantage of around 20% for infected females. The effective population size in the cages was estimated from SNP markers to be around a few thousand individuals, precluding large effects of genetic drift in the populations. The exact reasons for the fitness advantage are unclear but viral protection and nutritional benefits are two possibilities.}, }
@article {pmid29765742, year = {2018}, author = {Szebenyi, DM and Kriksunov, I and Howe, KJ and Ramsey, JS and Hall, DG and Heck, ML and Krasnoff, SB}, title = {Crystal structure of diaphorin methanol monosolvate isolated from Diaphorina citri Kuwayama, the insect vector of citrus greening disease.}, journal = {Acta crystallographica. Section E, Crystallographic communications}, volume = {74}, number = {Pt 4}, pages = {445-449}, pmid = {29765742}, issn = {2056-9890}, support = {P41 GM103485/GM/NIGMS NIH HHS/United States ; }, abstract = {The title compound C22H39NO9·CH3OH [systematic name: (S)-N-((S)-{(2S,4R,6R)-6-[(S)-2,3-di-hydroxy-prop-yl]-4-hy-droxy-5,5-di-methyl-tetra-hydro-2H-pyran-2-yl}(hy-droxy)meth-yl)-2-hy-droxy-2-[(2R,5R,6R)-2-meth-oxy-5,6-dimeth-yl-4-methyl-ene-tetra-hydro-2H-pyran-2-yl]acetamide methanol monosolvate], was isolated from the Asian citrus psyllid, Diaphorina citri Kuwayama, and crystallizes in the space group P21. 'Candidatus Profftella armatura' a bacterial endosymbiont of D. citri, biosynthesizes diaphorin, which is a hybrid polyketide-nonribosomal peptide comprising two highly substituted tetra-hydro-pyran rings joined by an N-acyl aminal bridge [Nakabachi et al. (2013 ▸). Curr. Biol.23, 1478-1484]. The crystal structure of the title compound establishes the complete relative configuration of diaphorin, which agrees at all nine chiral centers with the structure of the methanol monosolvate of the di-p-bromo-benzoate derivative of pederin, a biogenically related compound whose crystal structure was reported previously [Furusaki et al. (1968 ▸). Tetra-hedron Lett.9, 6301-6304]. Thus, the absolute configuration of diaphorin is proposed by analogy to that of pederin.}, }
@article {pmid29765368, year = {2018}, author = {Hu, W and Kuang, F and Lu, Z and Zhang, N and Chen, T}, title = {Killing Effects of an Isolated Serratia marcescens KH-001 on Diaphorina citri via Lowering the Endosymbiont Numbers.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {860}, pmid = {29765368}, issn = {1664-302X}, abstract = {Huanglongbing (HLB) is the most devastating citrus disease worldwide, and suppression of the Asian citrus psyllid (Diaphorina citri) is regarded as an effective method to inhibit the spread of HLB. In this study, we isolated a strain named as Serratia marcescens KH-001 from D. citri nymphs suffering from disease, and evaluated its killing effect on D. citri via toxicity test and effect on microbial community in D. citri using high-throughput sequencing. Our results indicated that S. marcescens KH-001 could effectively kill 83% of D. citri nymphs, while the fermentation products of S. marcescens KH-001 only killed 40% of the D. citrinymphs. High-throughput sequencing results indicated that the S. marcescens KH-001 increased the OTU numbers from 62.5 (PBS buffer) to 81.5, while significantly lowered the Shannon index compared with Escherichia coli DH5α (group E) (p < 0.05). OTU analysis showed that the S. marcescens KH-001 had significantly reduced the relative abundance of endosymbionts Wolbachia, Profftella, and Carsonella in group S compared with that in other groups (p < 0.05). Therefore, the direct killing effect of the fermentation products of S. marcescens KH-001 and the indirect effect via reducing the numbers of endosymbionts (Wolbachia, Profftella, and Carsonella) of D. citri endow S. marcescens KH-001 a sound killing effect on D. citri. Further work need to do before this strain is used as a sound biological control agents.}, }
@article {pmid29765363, year = {2018}, author = {Parkinson, JE and Tivey, TR and Mandelare, PE and Adpressa, DA and Loesgen, S and Weis, VM}, title = {Subtle Differences in Symbiont Cell Surface Glycan Profiles Do Not Explain Species-Specific Colonization Rates in a Model Cnidarian-Algal Symbiosis.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {842}, pmid = {29765363}, issn = {1664-302X}, abstract = {Mutualisms between cnidarian hosts and dinoflagellate endosymbionts are foundational to coral reef ecosystems. These symbioses are often re-established every generation with high specificity, but gaps remain in our understanding of the cellular mechanisms that control symbiont recognition and uptake dynamics. Here, we tested whether differences in glycan profiles among different symbiont species account for the different rates at which they initially colonize aposymbiotic polyps of the model sea anemone Aiptasia (Exaiptasia pallida). First, we used a lectin array to characterize the glycan profiles of colonizing Symbiodinium minutum (ITS2 type B1) and noncolonizing Symbiodinium pilosum (ITS2 type A2), finding subtle differences in the binding of lectins Euonymus europaeus lectin (EEL) and Urtica dioica agglutinin lectin (UDA) that distinguish between high-mannoside and hybrid-type protein linked glycans. Next, we enzymatically cleaved glycans from the surfaces of S. minutum cultures and followed their recovery using flow cytometry, establishing a 48-72 h glycan turnover rate for this species. Finally, we exposed aposymbiotic host polyps to cultured S. minutum cells masked by EEL or UDA lectins for 48 h, then measured cell densities the following day. We found no effect of glycan masking on symbiont density, providing further support to the hypothesis that glycan-lectin interactions are more important for post-phagocytic persistence of specific symbionts than they are for initial uptake. We also identified several methodological and biological factors that may limit the utility of studying glycan masking in the Aiptasia system.}, }
@article {pmid29764946, year = {2018}, author = {Wang, Y and Stata, M and Wang, W and Stajich, JE and White, MM and Moncalvo, JM}, title = {Comparative Genomics Reveals the Core Gene Toolbox for the Fungus-Insect Symbiosis.}, journal = {mBio}, volume = {9}, number = {3}, pages = {}, pmid = {29764946}, issn = {2150-7511}, mesh = {Animals ; Fungal Proteins/genetics/metabolism ; Fungi/classification/*genetics/isolation &amp; purification/physiology ; *Genome, Fungal ; Genomics ; Host-Pathogen Interactions ; Insecta/genetics/*microbiology/physiology ; Phylogeny ; *Symbiosis ; }, abstract = {Modern genomics has shed light on many entomopathogenic fungi and expanded our knowledge widely; however, little is known about the genomic features of the insect-commensal fungi. Harpellales are obligate commensals living in the digestive tracts of disease-bearing insects (black flies, midges, and mosquitoes). In this study, we produced and annotated whole-genome sequences of nine Harpellales taxa and conducted the first comparative analyses to infer the genomic diversity within the members of the Harpellales. The genomes of the insect gut fungi feature low (26% to 37%) GC content and large genome size variations (25 to 102 Mb). Further comparisons with insect-pathogenic fungi (from both Ascomycota and Zoopagomycota), as well as with free-living relatives (as negative controls), helped to identify a gene toolbox that is essential to the fungus-insect symbiosis. The results not only narrow the genomic scope of fungus-insect interactions from several thousands to eight core players but also distinguish host invasion strategies employed by insect pathogens and commensals. The genomic content suggests that insect commensal fungi rely mostly on adhesion protein anchors that target digestive system, while entomopathogenic fungi have higher numbers of transmembrane helices, signal peptides, and pathogen-host interaction (PHI) genes across the whole genome and enrich genes as well as functional domains to inactivate the host inflammation system and suppress the host defense. Phylogenomic analyses have revealed that genome sizes of Harpellales fungi vary among lineages with an integer-multiple pattern, which implies that ancient genome duplications may have occurred within the gut of insects.IMPORTANCE Insect guts harbor various microbes that are important for host digestion, immune response, and disease dispersal in certain cases. Bacteria, which are among the primary endosymbionts, have been studied extensively. However, fungi, which are also frequently encountered, are poorly known with respect to their biology within the insect guts. To understand the genomic features and related biology, we produced the whole-genome sequences of nine gut commensal fungi from disease-bearing insects (black flies, midges, and mosquitoes). The results show that insect gut fungi tend to have low GC content across their genomes. By comparing these commensals with entomopathogenic and free-living fungi that have available genome sequences, we found a universal core gene toolbox that is unique and thus potentially important for the insect-fungus symbiosis. This comparative work also uncovered different host invasion strategies employed by insect pathogens and commensals, as well as a model system to study ancient fungal genome duplication within the gut of insects.}, }
@article {pmid29761046, year = {2018}, author = {Zepeda-Paulo, F and Ortiz-Martínez, S and Silva, AX and Lavandero, B}, title = {Low bacterial community diversity in two introduced aphid pests revealed with 16S rRNA amplicon sequencing.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4725}, pmid = {29761046}, issn = {2167-8359}, abstract = {Bacterial endosymbionts that produce important phenotypic effects on their hosts are common among plant sap-sucking insects. Aphids have become a model system of insect-symbiont interactions. However, endosymbiont research has focused on a few aphid species, making it necessary to make greater efforts to other aphid species through different regions, in order to have a better understanding of the role of endosymbionts in aphids as a group. Aphid endosymbionts have frequently been studied by PCR-based techniques, using species-specific primers, nevertheless this approach may omit other non-target bacteria cohabiting a particular host species. Advances in high-throughput sequencing technologies are complementing our knowledge of microbial communities by allowing us the study of whole microbiome of different organisms. We used a 16S rRNA amplicon sequencing approach to study the microbiome of aphids in order to describe the bacterial community diversity in introduced populations of the cereal aphids, Sitobion avenae and Rhopalosiphum padi in Chile (South America). An absence of secondary endosymbionts and two common secondary endosymbionts of aphids were found in the aphids R. padi and S. avenae, respectively. Of those endosymbionts, Regiella insecticola was the dominant secondary endosymbiont among the aphid samples. In addition, the presence of a previously unidentified bacterial species closely related to a phytopathogenic Pseudomonad species was detected. We discuss these results in relation to the bacterial endosymbiont diversity found in other regions of the native and introduced range of S. avenae and R. padi. A similar endosymbiont diversity has been reported for both aphid species in their native range. However, variation in the secondary endosymbiont infection could be observed among the introduced and native populations of the aphid S. avenae, indicating that aphid-endosymbiont associations can vary across the geographic range of an aphid species. In addition, we discuss the potential role of aphids as vectors and/or alternative hosts of phytopathogenic bacteria.}, }
@article {pmid29761037, year = {2018}, author = {Duplouy, A and Hornett, EA}, title = {Uncovering the hidden players in Lepidoptera biology: the heritable microbial endosymbionts.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4629}, pmid = {29761037}, issn = {2167-8359}, abstract = {The Lepidoptera is one of the most widespread and recognisable insect orders. Due to their remarkable diversity, economic and ecological importance, moths and butterflies have been studied extensively over the last 200 years. More recently, the relationship between Lepidoptera and their heritable microbial endosymbionts has received increasing attention. Heritable endosymbionts reside within the host's body and are often, but not exclusively, inherited through the female line. Advancements in molecular genetics have revealed that host-associated microbes are both extremely prevalent among arthropods and highly diverse. Furthermore, heritable endosymbionts have been repeatedly demonstrated to play an integral role in many aspects of host biology, particularly host reproduction. Here, we review the major findings of research of heritable microbial endosymbionts of butterflies and moths. We promote the Lepidoptera as important models in the study of reproductive manipulations employed by heritable endosymbionts, with the mechanisms underlying male-killing and feminisation currently being elucidated in moths and butterflies. We also reveal that the vast majority of research undertaken of Lepidopteran endosymbionts concerns Wolbachia. While this highly prevalent bacterium is undoubtedly important, studies should move towards investigating the presence of other, and interacting endosymbionts, and we discuss the merits of examining the microbiome of Lepidoptera to this end. We finally consider the importance of understanding the influence of endosymbionts under global environmental change and when planning conservation management of endangered Lepidoptera species.}, }
@article {pmid29754986, year = {2018}, author = {Lado, P and Qurollo, B and Williams, C and Junge, R and Klompen, H}, title = {The microbiome of Haemaphysalis lemuris (Acari: Ixodidae), a possible vector of pathogens of endangered lemur species in Madagascar.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {5}, pages = {1252-1260}, doi = {10.1016/j.ttbdis.2018.05.003}, pmid = {29754986}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Babesia/genetics/isolation &amp; purification ; Bartonella/genetics/isolation &amp; purification ; Borrelia/genetics/isolation &amp; purification/pathogenicity ; Endangered Species ; Ixodidae/*microbiology ; Lemur/*parasitology ; *Microbiota ; Polymerase Chain Reaction ; Rickettsia/genetics/isolation &amp; purification/pathogenicity ; Tick Infestations/epidemiology/parasitology/*veterinary ; Tick-Borne Diseases/epidemiology/microbiology/*veterinary ; }, abstract = {Lemurs are primate species that are endemic to Madagascar. At present, about 90% of lemur species are endangered, and 5 species are among the 25 most endangered primates worldwide. Health status is a major factor impacting the viability of wild populations of many endangered species including lemurs. Given this context, we analyzed the microbiome of 24 specimens of Haemaphysalis lemuris, the most common tick parasitizing lemurs in their native habitats. Ticks were collected from 6 lemur species and microbiomes analyzed using next-generation sequencing. Our results show that the H. lemuris microbiome is highly diverse, including over 500 taxa, 267 of which were identified to genus level. Analysis of the microbiome also shows that there is a distinct "host" (lemur species) component when explaining the differences among and between microbial communities of H. lemuris. This "host" component seems to overwhelm any "locality" (geographic origin of the sample) component. In addition to the microbiome data, targeted PCR was used to test for the presence of three pathogens recently detected in the blood of wild lemurs: Borrelia sp., Candidatus Neoehrlichia sp., and Babesia sp. Overall, the presence of DNA of Rickettsia spp., Bartonella spp., Francisella spp., and a Babesia sp., in H. lemuris, is consistent with the hypothesis that these ectoparasites may act as vector for these pathogens. Further studies assessing vector competence are needed to confirm this hypothesis.}, }
@article {pmid29753223, year = {2018}, author = {Syed, B and Nagendra Prasad, MN and Mohan Kumar, K and Satish, S}, title = {Bioconjugated nano-bactericidal complex for potent activity against human and phytopathogens with concern of global drug resistant crisis.}, journal = {The Science of the total environment}, volume = {637-638}, number = {}, pages = {274-281}, doi = {10.1016/j.scitotenv.2018.04.405}, pmid = {29753223}, issn = {1879-1026}, mesh = {Anti-Bacterial Agents/*toxicity ; Anti-Infective Agents ; Humans ; Metal Nanoparticles/*toxicity ; Silver ; Silver Nitrate ; Spectroscopy, Fourier Transform Infrared ; }, abstract = {The present study emphasizes the need for novel antimicrobial agents to combat the global drug resistant crisis. The development of novel nanomaterials is reported to be of the alternative tool to combat drug resistant pathogens. In present investigation, bioconjugated nano-complex was developed from secondary metabolite secreted from endosymbiont. The endosymbiont capable of secreting antimicrobial metabolite was subjected to fermentation and the culture supernatant was assessed for purification of antimicrobial metabolite via bio-assay guided fraction techniques such as thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and column chromatography. The metabolite was characterized as 2,4-Diacetylphloroglucinol (2,4 DAPG) which was used to develop bioconjugated nano-complex by treating with 1 mM silver nitrate under optimized conditions. The purified metabolite 2,4 DAPG reduced silver nitrate to form bioconjugated nano-complex to form association with silver nanoparticles. The oxidized form of DAPG consists of four hard ligands that can conjugate on to the surface of silver nanoparticles cluster. The bioconjugation was confirmed with UV-visible spectroscopy which displayed the shift and shoulder peak in the absorbance spectra. This biomolecular interaction was further determined by the Fourier-transform spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses which displayed different signals ascertaining the molecular binding of 2,4,DAPG with silver nanoparticles. The transmission electron microscopy (TEM) analysis revealed the cluster formation due to bioconjugation. The XRD analysis revealed the crystalline nature of nano-complex with the characteristic peaks indexed to Bragg's reflection occurring at 2θ angle which indicated the (111), (200), (220) and (311) planes. The activity of bioconjugated nano-complex was tested against 12 significant human and phytopathogens. Among all the test pathogens, Shigella flexneri (MTCC 1457) was the most sensitive organisms with 38.33 ± 0.33 zone of inhibition. The results obtained in the present investigation attribute development of nano-complex as one of the effective tools against multi-drug resistant infections across the globe.}, }
@article {pmid29749703, year = {2020}, author = {Ayoubi, A and Talebi, AA and Fathipour, Y and Mehrabadi, M}, title = {Coinfection of the secondary symbionts, Hamiltonella defensa and Arsenophonus sp. contribute to the performance of the major aphid pest, Aphis gossypii (Hemiptera: Aphididae).}, journal = {Insect science}, volume = {27}, number = {1}, pages = {86-98}, doi = {10.1111/1744-7917.12603}, pmid = {29749703}, issn = {1744-7917}, mesh = {Animals ; Aphids/growth &amp; development/*microbiology/*physiology ; Buchnera/*physiology ; Enterobacteriaceae/*physiology ; Iran ; Nymph/growth &amp; development/microbiology ; Reproduction ; Species Specificity ; *Symbiosis ; }, abstract = {Bacterial endosymbionts play important roles in ecological traits of aphids. In this study, we characterize the bacterial endosymbionts of A. gossypii collected in Karaj, Iran and their role in the performance of the aphid. Our results indicated that beside Buchnera aphidicola, A. gossypii, also harbors both Hamiltonella defensa and Arsenophonus sp. Quantitative PCR (qPCR) results revealed that the populations of the endosymbionts increased throughout nymphal development up to adult emergence; thereafter, populations of Buchnera and Arsenophonus were diminished while the density of H. defensa constantly increased. Buchnera reduction caused prolonged development and no progeny production. Furthermore, secondary symbiont reduction led to reduction of the total life span and intrinsic rate of natural increase as well as appearance of the deformed dead offspring in comparison with the control insects. Reduction of the secondary symbionts did not affect parasitism rate of the aphid by the parasitic wasp Aphidius matricariae. Together these findings showed that H. defensa and Arsenophonus contributed to the fitness of A. gossypii by enhancing its performance, but not through parasitoid resistance.}, }
@article {pmid29748120, year = {2018}, author = {Špitalská, E and Sparagano, O and Stanko, M and Schwarzová, K and Špitalský, Z and Škultéty, &#x13d; and Havlíková, SF}, title = {Diversity of Coxiella-like and Francisella-like endosymbionts, and Rickettsia spp., Coxiella burnetii as pathogens in the tick populations of Slovakia, Central Europe.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {5}, pages = {1207-1211}, doi = {10.1016/j.ttbdis.2018.05.002}, pmid = {29748120}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Infections/epidemiology/transmission ; Coxiella/cytology/genetics/isolation &amp; purification/pathogenicity ; Coxiella burnetii/genetics/*isolation &amp; purification/pathogenicity ; DNA, Bacterial/genetics ; Dermacentor/microbiology ; Female ; Francisella/classification/genetics/*isolation &amp; purification/pathogenicity ; Ixodes/microbiology ; Ixodidae/*microbiology ; Male ; Phylogeny ; Public Health ; Rickettsia/genetics/*isolation &amp; purification/pathogenicity ; Slovakia/epidemiology ; Symbiosis ; }, abstract = {Ticks are important vectors of pathogens affecting humans and animals worldwide. They do not only carry pathogens but diverse commensal and symbiotic microorganisms are also present in ticks. A molecular screening for tick-borne pathogens and endosymbionts was carried out in Ixodes ricinus, Dermacentor reticulatus and Haemaphysalis inermis questing ticks collected in Slovakia. The presence of Rickettsia spp., Coxiella burnetii, Coxiella-like and Francisella-like microorganisms was evaluated by PCR in 605 individuals and by randomly sequencing 66 samples. Four species of rickettsiae (R. raoultii, R. slovaca, R. helvetica and R. monacensis) were identified and reported with an overall prevalence range between 0.4 and 50.3% (±8.0) depending on tick species, sex and locality. Partial sequencing of the gltA gene of 5 chosen samples in H. inermis showed 99% identity with Candidatus Rickettsia hungarica. The total prevalence of C. burnetii in ticks was 2.2 ± 1.7%; bacteria were confirmed in I. ricinus and D. reticulatus ticks. The sequences from 2 D. reticulatus males and 1 I. ricinus female ticks were compared to GenBank submissions and a 99.8% match was obtained with the pathogenic C. burnetii. Coxiella-like endosymbionts were registered in all three species of ticks from all studied sites with an average prevalence of 32.7 ± 3.7%. A phylogenetic analysis of this Coxiella sp. showed that it does not group with the pathogenic C. burnetii. The prevalence of Francisella-like microorganisms in questing ticks was 47.9 ± 3.9%, however H. inermis (n = 108) were not infested. Obtained sequences were 98% identical with previously identified Francisella-like endosymbionts in D. reticulatus and I. ricinus. Coxiella-like and Francisella-like microorganisms were identified for the first time in Slovakia, they might be considered as a non-pathogenic endosymbiont of I. ricinus, D. reticulatus and H. inermis, and future investigations could aim to assess their role in these ticks. However, this work provided further data and broadened our knowledge on bacterial pathogens and endosymbionts present in ticks in Slovakia to help understanding co-infestations, combined treatments and public health issues linked to tick bites.}, }
@article {pmid29739445, year = {2018}, author = {Sorek, M and Schnytzer, Y and Waldman Ben-Asher, H and Caspi, VC and Chen, CS and Miller, DJ and Levy, O}, title = {Setting the pace: host rhythmic behaviour and gene expression patterns in the facultatively symbiotic cnidarian Aiptasia are determined largely by Symbiodinium.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {83}, pmid = {29739445}, issn = {2049-2618}, support = {1294//Taiwan-Israel cooperative program/International ; }, mesh = {Animals ; Biological Clocks/*physiology ; Circadian Rhythm/genetics/*physiology ; Dinoflagellida/*metabolism ; Gene Expression Regulation/*genetics ; Oxygen/metabolism ; Sea Anemones/*genetics/parasitology ; Symbiosis/physiology ; }, abstract = {BACKGROUND: All organisms employ biological clocks to anticipate physical changes in the environment; however, the integration of biological clocks in symbiotic systems has received limited attention. In corals, the interpretation of rhythmic behaviours is complicated by the daily oscillations in tissue oxygen tension resulting from the photosynthetic and respiratory activities of the associated algal endosymbiont Symbiodinium. In order to better understand the integration of biological clocks in cnidarian hosts of Symbiodinium, daily rhythms of behaviour and gene expression were studied in symbiotic and aposymbiotic morphs of the sea-anemone Aiptasia diaphana.<br><br>RESULTS: The results showed that whereas circatidal (approx. 12-h) cycles of activity and gene expression predominated in aposymbiotic morphs, circadian (approx. 24-h) patterns were the more common in symbiotic morphs, where the expression of a significant number of genes shifted from a 12- to 24-h rhythm. The behavioural experiments on symbiotic A. diaphana displayed diel (24-h) rhythmicity in body and tentacle contraction under the light/dark cycles, whereas aposymbiotic morphs showed approximately 12-h (circatidal) rhythmicity. Reinfection experiments represent an important step in understanding the hierarchy of endogenous clocks in symbiotic associations, where the aposymbiotic Aiptasia morphs returned to a 24-h behavioural rhythm after repopulation with algae.<br><br>CONCLUSION: Whilst some modification of host metabolism is to be expected, the extent to which the presence of the algae modified host endogenous behavioural and transcriptional rhythms implies that it is the symbionts that influence the pace. Our results clearly demonstrate the importance of the endosymbiotic algae in determining the timing and the duration of the extension and contraction of the body and tentacles and temporal gene expression.}, }
@article {pmid29732657, year = {2018}, author = {Zheng, Y and Bi, J and Hou, MY and Shen, W and Zhang, W and Ai, H and Yu, XQ and Wang, YF}, title = {Ocnus is essential for male germ cell development in Drosophila melanogaster.}, journal = {Insect molecular biology}, volume = {27}, number = {5}, pages = {545-555}, doi = {10.1111/imb.12393}, pmid = {29732657}, issn = {1365-2583}, mesh = {Animals ; Drosophila Proteins/*physiology ; Drosophila melanogaster/*physiology ; Fertility ; *Gene Expression Regulation ; Male ; Phosphoric Monoester Hydrolases/*physiology ; *Spermatogenesis ; Testis/growth &amp; development ; Transcriptome ; }, abstract = {The ocnus (ocn) gene encodes a protein abundant in the testes, implying its role in testis development. When Drosophila melanogaster is infected with the endosymbiont wMel Wolbachia, which affects the spermatogenesis of its hosts, ocn is downregulated in the third-instar larval testes, suggesting a role of ocn in spermatogenesis. In this study, we knocked down ocn in the testes and found that the hatch rates of embryos derived from ocn-knockdown males were significantly decreased, and 84.38% of the testes were much smaller in comparison to controls. Analysis of the smaller testes showed no germ cells but they had an extended hub. Using RNA-sequencing (RNA-Seq), we identified 69 genes with at least a twofold change (q-value < 5%) in their expression after ocn knockdown; of these, eight testes-specific and three reproduction-related genes were verified to be significantly downregulated using quantitative reverse transcription-PCR. Three genes (orientation disruptor, p24-2 and CG13541) were also significantly downregulated in the presence of Wolbachia. Furthermore, 98 genes were not expressed when ocn was knocked down in testes. These results suggest that ocn plays a crucial role in male germ cell development in Drosophila, possibly by regulating the expression of multiple spermatogenesis-related genes. Our data provide important information to help understand the molecular regulatory mechanisms underlying spermatogenesis.}, }
@article {pmid29725059, year = {2018}, author = {Dittmer, J and Bouchon, D}, title = {Feminizing Wolbachia influence microbiota composition in the terrestrial isopod Armadillidium vulgare.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {6998}, pmid = {29725059}, issn = {2045-2322}, mesh = {Animal Structures/*microbiology ; Animals ; Bacteria/classification/genetics ; Isopoda/*microbiology ; Metagenomics ; Microbial Interactions ; *Microbiota ; Wolbachia/*growth &amp; development ; }, abstract = {Wolbachia are widespread heritable endosymbionts of arthropods notorious for their profound effects on host fitness as well as for providing protection against viruses and eukaryotic parasites, indicating that they can interact with other microorganisms sharing the same host environment. Using the terrestrial isopod crustacean Armadillidium vulgare, its highly diverse microbiota (>200 bacterial genera) and its three feminizing Wolbachia strains (wVulC, wVulM, wVulP) as a model system, the present study demonstrates that Wolbachia can even influence the composition of a diverse bacterial community under both laboratory and natural conditions. While host origin is the major determinant of the taxonomic composition of the microbiota in A. vulgare, Wolbachia infection affected both the presence and, more importantly, the abundance of many bacterial taxa within each host population, possibly due to competitive interactions. Moreover, different Wolbachia strains had different impacts on microbiota composition. As such, infection with wVulC affected a higher number of taxa than infection with wVulM, possibly due to intrinsic differences in virulence and titer between these two strains. In conclusion, this study shows that heritable endosymbionts such as Wolbachia can act as biotic factors shaping the microbiota of arthropods, with as yet unknown consequences on host fitness.}, }
@article {pmid29724860, year = {2018}, author = {Garg, SG and Martin, WF}, title = {Asking endosymbionts to do an enzyme's job.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {20}, pages = {E4543-E4544}, pmid = {29724860}, issn = {1091-6490}, mesh = {*Biological Evolution ; Enzymes/*metabolism ; Mitochondria ; *Symbiosis ; }, }
@article {pmid29720714, year = {2018}, author = {Pereira, TN and Rocha, MN and Sucupira, PHF and Carvalho, FD and Moreira, LA}, title = {Wolbachia significantly impacts the vector competence of Aedes aegypti for Mayaro virus.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {6889}, pmid = {29720714}, issn = {2045-2322}, mesh = {Aedes/microbiology/*virology ; Animals ; Cell Line ; Cells, Cultured ; Female ; Humans ; Mosquito Vectors/microbiology/*virology ; Symbiosis ; Togaviridae/pathogenicity/*physiology ; Togaviridae Infections/transmission ; *Virus Replication ; Wolbachia/*pathogenicity ; }, abstract = {Wolbachia, an intracellular endosymbiont present in up to 70% of all insect species, has been suggested as a sustainable strategy for the control of arboviruses such as Dengue, Zika and Chikungunya. As Mayaro virus outbreaks have also been reported in Latin American countries, the objective of this study was to evaluate the vector competence of Brazilian field-collected Ae. aegypti and the impact of Wolbachia (wMel strain) upon this virus. Our in vitro studies with Aag2 cells showed that Mayaro virus can rapidly multiply, whereas in wMel-infected Aag2 cells, viral growth was significantly impaired. In addition, C6/36 cells seem to have alterations when infected by Mayaro virus. In vivo experiments showed that field-collected Ae. aegypti mosquitoes are highly permissive to Mayaro virus infection, and high viral prevalence was observed in the saliva. On the other hand, Wolbachia-harboring mosquitoes showed significantly impaired capability to transmit Mayaro virus. Our results suggest that the use of Wolbachia-harboring mosquitoes may represent an effective mechanism for the reduction of Mayaro virus transmission throughout Latin America.}, }
@article {pmid29713316, year = {2018}, author = {Garushyants, SK and Beliavskaia, AY and Malko, DB and Logacheva, MD and Rautian, MS and Gelfand, MS}, title = {Comparative Genomic Analysis of Holospora spp., Intranuclear Symbionts of Paramecia.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {738}, pmid = {29713316}, issn = {1664-302X}, abstract = {While most endosymbiotic bacteria are transmitted only vertically, Holospora spp., an alphaproteobacterium from the Rickettsiales order, can desert its host and invade a new one. All bacteria from the genus Holospora are intranuclear symbionts of ciliates Paramecium spp. with strict species and nuclear specificity. Comparative metabolic reconstruction based on the newly sequenced genome of Holospora curviuscula, a macronuclear symbiont of Paramecium bursaria, and known genomes of other Holospora species shows that even though all Holospora spp. can persist outside the host, they cannot synthesize most of the essential small molecules, such as amino acids, and lack some central energy metabolic pathways, including glycolysis and the citric acid cycle. As the main energy source, Holospora spp. likely rely on nucleotides pirated from the host. Holospora-specific genes absent from other Rickettsiales are possibly involved in the lifestyle switch from the infectious to the reproductive form and in cell invasion.}, }
@article {pmid29709692, year = {2018}, author = {Steiner, FM and Csősz, S and Markó, B and Gamisch, A and Rinnhofer, L and Folterbauer, C and Hammerle, S and Stauffer, C and Arthofer, W and Schlick-Steiner, BC}, title = {Turning one into five: Integrative taxonomy uncovers complex evolution of cryptic species in the harvester ant Messor "structor".}, journal = {Molecular phylogenetics and evolution}, volume = {127}, number = {}, pages = {387-404}, doi = {10.1016/j.ympev.2018.04.005}, pmid = {29709692}, issn = {1095-9513}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Amplified Fragment Length Polymorphism Analysis ; Animals ; Ants/anatomy &amp; histology/*classification/genetics/microbiology ; *Biological Evolution ; DNA, Mitochondrial/genetics ; Discriminant Analysis ; Ecosystem ; Female ; Male ; Models, Theoretical ; Phylogeny ; Principal Component Analysis ; Species Specificity ; Terminology as Topic ; Wolbachia/physiology ; }, abstract = {Seed harvesting ants are ecosystem engineers that shape vegetation, nutrient cycles, and microclimate. Progress in ecological research is, however, slowed down by poor species delimitation. For example, it has not been resolved to date, how many species the European harvester ant Messor "structor" (Latreille, 1798) represents. Since its first description, splitting into additional taxa was often proposed but not accepted later on due to inconsistent support from morphology and ecology. Here, we took an iterative integrative-taxonomy approach - comparing multiple, independent data sets of the same sample - and used traditional morphometrics, Wolbachia symbionts, mitochondrial DNA, amplified fragment length polymorphism, and ecological niche modelling. Using the complementarity of the data sets applied, we resolved multiple, strong disagreements over the number of species, ranging from four to ten, and the allocation of individuals to species. We consider most plausible a five-species hypothesis and conclude the taxonomic odyssey by redescribing Messor structor, M. ibericus Santschi, 1925, and M. muticus (Nylander, 1849) stat.rev., and by describing two new species, M. ponticus sp.n. and M. mcarthuri sp.n. The evolutionary explanations invoked in resolving the various data conflicts include pronounced morphological crypsis, incomplete lineage-sorting or ongoing cospeciation of endosymbionts, and peripatric speciation - these ants' significance to evolutionary biology parallels that to ecology. The successful solution of this particular problem illustrates the usefulness of the integrative approach to other systematic problems of comparable complexity and the importance of understanding evolution to drawing correct conclusions on species' attributes, including their ecology and biogeography.}, }
@article {pmid29702243, year = {2018}, author = {Lv, ZH and Wei, XY and Tao, YL and Chu, D}, title = {Differential susceptibility of whitefly-associated bacteria to antibiotic as revealed by metagenomics analysis.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {63}, number = {}, pages = {24-29}, doi = {10.1016/j.meegid.2018.04.024}, pmid = {29702243}, issn = {1567-7257}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Bacteria/*drug effects/genetics/*isolation &amp; purification ; *Drug Resistance, Bacterial ; Genome, Bacterial ; Hemiptera/*microbiology ; *Metagenomics ; }, abstract = {BACKGROUND: Recent reports have suggested that different symbionts of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) have differential susceptibility to antibiotic treatment. Changes in the community structure of B. tabaci-associated bacterial microbiota (BABM) following antibiotic treatment, however, remain poorly understood, although increasing numbers of B. tabaci-associated bacteria have been reported in recent years.<br><br>METHODOLOGY AND RESULTS: The BABM of male or female B. tabaci Q (also known as B. tabaci MED species) were analyzed after being fed on artificial diet containing the antibiotic rifampicin and compared with untreated controls. The bacterial 16S rDNA gene amplicon metagenomic sequencing method was used in the analyses. The results showed that the BABM in male and female adults have different characteristics, and that the community structure of the BABM changes drastically following antibiotic treatment. Further analysis of the endosymbionts in B. tabaci showed that the relative abundance of the primary endosymbiont, Portiera, increased in females but was unchanged in male whiteflies, while that of the secondary endosymbiont, Hamiltonella, significantly decreased in both male and female whiteflies. The secondary endosymbionts, Cardinium and Rickettsia, were apparently not affected in either male or female whiteflies.<br><br>CONCLUSIONS: The community structure of BABM can be drastically altered following treatment with the antibiotic, rifampicin. This may be due to different antibiotic susceptibilities among the bacterial species. These results provide valuable insights into the innate differences in the BABM of male and female whiteflies, as well as structural changes that occur in the BABM in response to exposure to an antibiotic.}, }
@article {pmid29700820, year = {2018}, author = {Kremer, JMM and Nooten, SS and Cook, JM and Ryalls, JMW and Barton, CVM and Johnson, SN}, title = {Elevated atmospheric carbon dioxide concentrations promote ant tending of aphids.}, journal = {The Journal of animal ecology}, volume = {87}, number = {5}, pages = {1475-1483}, doi = {10.1111/1365-2656.12842}, pmid = {29700820}, issn = {1365-2656}, mesh = {Animals ; *Ants ; *Aphids ; Carbon Dioxide ; Plants ; Symbiosis ; }, abstract = {Animal mutualisms, which involve beneficial interactions between individuals of different species, are common in nature. Insect-insect mutualism, for example, is widely regarded as a keystone ecological interaction. Some mutualisms are anticipated to be modified by climate change, but the focus has largely been on plant-microbe and plant-animal mutualisms rather than those between animals. Ant-aphid mutualisms, whereby ants tend aphids to harvest their honeydew excretions and, in return, provide protection for the aphids, are widespread. The mutualism is heavily influenced by the quality and quantity of honeydew produced by aphids, which is directly affected by host plant quality. As predicted increases in concentrations of atmospheric carbon dioxide (eCO2) are widely reported to affect plant nutritional chemistry, this may also alter honeydew quality and hence the nature of ant-aphid mutualisms. Using glasshouse chambers and field-based open-top chambers, we determined the effect of eCO2 on the growth and nutritional quality (foliar amino acids) of lucerne (Medicago sativa). We determined how cowpea aphid (Aphis craccivora) populations and honeydew production were impacted when feeding on such plants and how this affected the tending behaviour of ants (Iridomyrmex sp.). eCO2 stimulated plant growth but decreased concentrations of foliar amino acids by 29% and 14% on aphid-infested plants and aphid-free plants, respectively. Despite the deterioration in host plant quality under eCO2 , aphids maintained performance and populations were unchanged by eCO2 . Aphids induced higher concentrations of amino acids (glutamine, asparagine, glutamic acid and aspartic acid) important for endosymbiont-mediated synthesis of essential amino acids. Aphids feeding under eCO2 also produced over three times more honeydew than aphids feeding under ambient CO2 , suggesting they were imbibing more phloem sap at eCO2 . The frequency of ant tending of aphids more than doubled in response to eCO2 . To our knowledge, this is the first study to demonstrate the effects of atmospheric change on an ant-aphid mutualism. In particular, these results highlight how impending changes to concentrations of atmospheric CO2 may alter mutualistic behaviour between animals. These could include positive impacts, as reported here, shifts from mutualism to antagonism, partner switches and mutualism abandonment.}, }
@article {pmid29690900, year = {2018}, author = {Tomassone, L and Portillo, A and Nováková, M and de Sousa, R and Oteo, JA}, title = {Neglected aspects of tick-borne rickettsioses.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {263}, pmid = {29690900}, issn = {1756-3305}, mesh = {Animals ; Disease Reservoirs ; Humans ; Neglected Diseases/*epidemiology ; Rickettsia Infections/*epidemiology ; Tick-Borne Diseases/*epidemiology ; Ticks/growth &amp; development/microbiology ; }, abstract = {Rickettsioses are among the oldest known infectious diseases. In spite of this, and of the extensive research carried out, many aspects of the biology and epidemiology of tick-borne rickettsiae are far from being completely understood. Their association with arthropod vectors, the importance of vertebrates as reservoirs, the rarity of clinical signs in animals, or the interactions of pathogenic species with rickettsial endosymbionts and with the host intracellular environment, are only some examples. Moreover, new rickettsiae are continuously being discovered. In this review, we focus on the 'neglected' aspects of tick-borne rickettsioses and on the gaps in knowledge, which could help to explain why these infections are still emerging and re-emerging threats worldwide.}, }
@article {pmid29689195, year = {2018}, author = {Foray, V and Pérez-Jiménez, MM and Fattouh, N and Landmann, F}, title = {Wolbachia Control Stem Cell Behavior and Stimulate Germline Proliferation in Filarial Nematodes.}, journal = {Developmental cell}, volume = {45}, number = {2}, pages = {198-211.e3}, doi = {10.1016/j.devcel.2018.03.017}, pmid = {29689195}, issn = {1878-1551}, mesh = {Animals ; Brugia malayi/*growth &amp; development/microbiology ; Cell Proliferation ; Female ; Filariasis/metabolism/parasitology/*pathology ; Germ Cells/*cytology/microbiology/physiology ; Helminth Proteins/genetics/*metabolism ; Male ; Stem Cells/cytology/microbiology/*physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Although symbiotic interactions are ubiquitous in the living world, examples of developmental symbioses are still scarce. We show here the crucial role of Wolbachia in the oogenesis of filarial nematodes, a class of parasites of biomedical and veterinary relevance. We applied newly developed techniques to demonstrate the earliest requirements of Wolbachia in the parasite germline preceding the production of faulty embryos in Wolbachia-depleted nematodes. We show that Wolbachia stimulate germline proliferation in a cell-autonomous manner, and not through nucleotide supplementation as previously hypothesized. We also found Wolbachia to maintain the quiescence of a pool of germline stem cells to ensure a constant delivery of about 1,400 eggs per day for many years. The loss of quiescence upon Wolbachia depletion as well as the disorganization of the distal germline suggest that Wolbachia are required to execute the proper germline stem cell developmental program in order to produce viable eggs and embryos.}, }
@article {pmid29684214, year = {2018}, author = {Nakai, M}, title = {New Perspectives on Chloroplast Protein Import.}, journal = {Plant &amp; cell physiology}, volume = {59}, number = {6}, pages = {1111-1119}, doi = {10.1093/pcp/pcy083}, pmid = {29684214}, issn = {1471-9053}, mesh = {Chloroplast Proteins/*metabolism ; Chloroplasts/metabolism ; Photosynthesis ; Plants/*metabolism ; *Protein Transport ; }, abstract = {Virtually all chloroplasts in extant photosynthetic eukaryotes derive from a single endosymbiotic event that probably occurred more than a billion years ago between a host eukaryotic cell and a cyanobacterium-like ancestor. Many endosymbiont genes were subsequently transferred to the host nuclear genome, concomitant with the establishment of a system for protein transport through the chloroplast double-membrane envelope. Presently, 2,000-3,000 different nucleus-encoded chloroplast proteins must be imported into the chloroplast following their synthesis in the cytosol. The TOC (translocon at the outer envelope membrane of chloroplasts) and TIC (translocon at the inner envelope membrane of chloroplasts) complexes are protein translocation machineries at the outer and inner envelope membranes, respectively, that facilitate this chloroplast protein import with the aid of a TIC-associated ATP-driven import motor. All the essential components of this protein import system seemed to have been identified through biochemical analyses and subsequent genetic studies that initiated in the late 1990s. However, in 2013, the Nakai group reported a novel inner envelope membrane TIC complex, for which a novel ATP-driven import motor associated with this TIC complex is likely to exist. In this mini review, I will summarize these recent discoveries together with new, or reanalyzed, data presented by other groups in recent years. Whereas the precise concurrent view of chloroplast protein import is still a matter of some debate, it is anticipated that the entire TOC/TIC/ATP motor system, including any novel components, will be conclusively established in the next decade. Such findings may lead to an extensively revised view of the evolution and molecular mechanisms of chloroplast protein import.}, }
@article {pmid29680900, year = {2018}, author = {Duzs, &#xc1; and Tóth, A and Németh, B and Balogh, T and Kós, PB and Rákhely, G}, title = {A novel enzyme of type VI sulfide:quinone oxidoreductases in purple sulfur photosynthetic bacteria.}, journal = {Applied microbiology and biotechnology}, volume = {102}, number = {12}, pages = {5133-5147}, doi = {10.1007/s00253-018-8973-x}, pmid = {29680900}, issn = {1432-0614}, mesh = {Bacteroides/classification/*enzymology ; Gene Expression Regulation, Bacterial ; Oxidation-Reduction ; Phylogeny ; Quinone Reductases/*metabolism ; Recombinant Proteins/genetics/metabolism ; Sulfides/metabolism ; }, abstract = {Sulfide detoxification can be catalyzed by ancient membrane-bound flavoproteins, sulfide:quinone oxidoreductases (Sqr), which have important roles in sulfide homeostasis and sulfide-dependent energy conservation processes by transferring electrons from sulfide to respiratory or photosynthetic membrane electron flow. Sqr enzymes have been categorized into six groups. Several members of the groups I, II, III, and V are well-known, but type IV and VI Sqrs are, as yet, uncharacterized or hardly characterized at all. Here, we report detailed characterization of a type VI sulfide:quinone oxidoreductase (TrSqrF) from a purple sulfur bacterium, Thiocapsa roseopersicina. Phylogenetic analysis classified this enzyme in a special group composed of SqrFs of endosymbionts, while a weaker relationship could be observed with SqrF of Chlorobaculum tepidum which is the only type VI enzyme characterized so far. Directed mutagenesis experiments showed that TrSqrF contributed substantially to the sulfide:quinone oxidoreductase activity of the membranes. Expression of the sqrF gene could be induced by sulfide. Homologous recombinant TrSqrF protein was expressed and purified from the membranes of a SqrF-deleted T. roseopersicina strain. The purified protein contains redox-active covalently bound FAD cofactor. The recombinant TrSqrF enzyme catalyzes sulfur-dependent quinone reduction and prefers ubiquinone-type quinone compounds. Kinetic parameters of TrSqrF show that the affinity of the enzyme is similar to duroquinone and decylubiquinone, but the reaction has substantially lower activation energy with decylubiquinone, indicating that the quinone structure has an effect on the catalytic process. TrSqrF enzyme affinity for sulfide is low, therefore, in agreement with the gene expressional analyis, SqrF could play a role in energy-conserving sulfide oxidation at high sulfide concentrations. TrSqrF is a good model enzyme for the subgroup of type VI Sqrs of endosymbionts and its characterization might provide deeper insight into the molecular details of the ancient, anoxic, energy-gaining processes using sulfide as an electron donor.}, }
@article {pmid29680541, year = {2018}, author = {Baliarsingh, SK and Lotliker, AA and Sudheesh, V and Samanta, A and Das, S and Vijayan, AK}, title = {Response of phytoplankton community and size classes to green Noctiluca bloom in the northern Arabian Sea.}, journal = {Marine pollution bulletin}, volume = {129}, number = {1}, pages = {222-230}, doi = {10.1016/j.marpolbul.2018.02.031}, pmid = {29680541}, issn = {1879-3363}, mesh = {Animals ; Biomass ; Copepoda/growth &amp; development ; Diatoms/*growth &amp; development/physiology ; Dinoflagellida/*growth &amp; development/physiology ; Environmental Monitoring/*methods ; Eutrophication ; Indian Ocean ; Nitrogen/analysis ; Phosphorus/analysis ; Photosynthesis/physiology ; Phytoplankton/*growth &amp; development/physiology ; Satellite Imagery ; Seasons ; }, abstract = {A comprehensive analysis on the phytoplankton ecology with special reference to different phytoplankton size classes was carried out at green Noctiluca scintillans (hereafter Noctiluca) bloom and non-bloom locations in offshore waters of the northern Arabian Sea. At the bloom locations, green Noctiluca represented a dense mono-specific proliferation with average cell density of 10.16 ± 5.806 × 10[4] cells-L[-1] and relative abundance share of 98.63%. Active photosynthesis through prasinophytic endosymbiont was depicted from net community production magnitude reaching 85.26 mgC/m[3]/Day under low prey abundance. Parallel swarming of Porpita porpita, a voracious copepod feeder signified the competitive advantage of Noctiluca to have the phytoplankton prey. Average concentration of picophytoplankton biomass was eleven times lower in surface waters of non-bloom stations in comparison to bloom. Higher N:P ratio in subsurface waters of non-bloom stations signified non-utilization of nitrogenous nutrients. Green Noctiluca bloom onset subsequent to diatom rich conditions was evident from spatio-temporal ocean colour satellite imageries.}, }
@article {pmid29678149, year = {2018}, author = {Kim, JI and Yoon, HS and Yi, G and Shin, W and Archibald, JM}, title = {Comparative mitochondrial genomics of cryptophyte algae: gene shuffling and dynamic mobile genetic elements.}, journal = {BMC genomics}, volume = {19}, number = {1}, pages = {275}, pmid = {29678149}, issn = {1471-2164}, mesh = {Cryptophyta/*genetics ; Gene Rearrangement ; Genome, Mitochondrial/*genetics ; *Genomics ; Interspersed Repetitive Sequences/*genetics ; Phylogeny ; }, abstract = {BACKGROUND: Cryptophytes are an ecologically important group of algae comprised of phototrophic, heterotrophic and osmotrophic species. This lineage is of great interest to evolutionary biologists because their plastids are of red algal secondary endosymbiotic origin. Cryptophytes have a clear phylogenetic affinity to heterotrophic eukaryotes and possess four genomes: host-derived nuclear and mitochondrial genomes, and plastid and nucleomorph genomes of endosymbiotic origin.<br><br>RESULTS: To gain insight into cryptophyte mitochondrial genome evolution, we sequenced the mitochondrial DNAs of five species and performed a comparative analysis of seven genomes from the following cryptophyte genera: Chroomonas, Cryptomonas, Hemiselmis, Proteomonas, Rhodomonas, Storeatula and Teleaulax. The mitochondrial genomes were similar in terms of their general architecture, gene content and presence of a large repeat region. However, gene order was poorly conserved. Characteristic features of cryptophyte mtDNAs included large syntenic clusters resembling &#x3b1;-proteobacterial operons that encode bacteria-like rRNAs, tRNAs, and ribosomal protein genes. The cryptophyte mitochondrial genomes retain almost all genes found in many other eukaryotes including the nad, sdh, cox, cob, and atp genes, with the exception of sdh2 and atp3. In addition, gene cluster analysis showed that cryptophytes possess a gene order closely resembling the jakobid flagellates Jakoba and Reclinomonas. Interestingly, the cox1 gene of R. salina, T. amphioxeia, and Storeatula species was found to contain group II introns encoding a reverse transcriptase protein, as did the cob gene of Storeatula species CCMP1868.<br><br>CONCLUSIONS: These newly sequenced genomes increase the breadth of data available from algae and will aid in the identification of general trends in mitochondrial genome evolution. While most of the genomes were highly conserved, extensive gene arrangements have shuffled gene order, perhaps due to genome rearrangements associated with hairpin-containing mobile genetic elements, tRNAs with palindromic sequences, and tandem repeat sequences. The cox1 and cob gene sequences suggest that introns have recently been acquired during cryptophyte evolution. Comparison of phylogenetic trees based on plastid and mitochondrial genome data sets underscore the different evolutionary histories of the host and endosymbiont components of present-day cryptophytes.}, }
@article {pmid29676724, year = {2018}, author = {Monsanto-Hearne, V and Johnson, KN}, title = {Wolbachia-mediated protection of Drosophila melanogaster against systemic infection with its natural viral pathogen Drosophila C virus does not involve changes in levels of highly abundant miRNAs.}, journal = {The Journal of general virology}, volume = {99}, number = {6}, pages = {827-831}, doi = {10.1099/jgv.0.001064}, pmid = {29676724}, issn = {1465-2099}, mesh = {Animals ; Dicistroviridae/*pathogenicity ; Drosophila melanogaster/*genetics/microbiology/virology ; Host-Pathogen Interactions/*genetics ; MicroRNAs/*genetics ; Real-Time Polymerase Chain Reaction ; Symbiosis ; Virus Diseases/microbiology ; Wolbachia/*physiology ; }, abstract = {The presence of Wolbachia confers virus protection to insects. The molecular mechanism underlying Wolbachia-mediated protection in this tripartite host-endosymbiont-virus interaction is not yet fully understood. In the bipartite association between Drosophila melanogaster and Drosophila C virus (DCV), changes in the expression of microRNAs (miRNAs) influence the outcome of viral pathogenesis. Here we examined whether changes in miRNA expression are similarly involved in the Drosophila-Wolbachia-DCV association. The levels of highly abundant miRNAs in D. melanogaster, Wolbachia-mono-infected D. melanogaster, and DCV- and Wolbachia-bi-infected D. melanogaster were quantified using RT-qPCR and compared. The results show that the abundance of the 17 tested D. melanogaster miRNAs is not affected by Wolbachia endosymbiosis or by bi-infection of Wolbachia and DCV. These results suggest that the in vivo protection conferred by Wolbachia to its native host against D. melanogaster's natural pathogen DCV is not likely to be dependent on or associated with changes in the levels of highly expressed miRNAs.}, }
@article {pmid29674178, year = {2018}, author = {Rataj, M and Vďačný, P}, title = {Dawn of astome ciliates in light of morphology and time-calibrated phylogeny of Haptophrya planariarum, an obligate endosymbiont of freshwater turbellarians.}, journal = {European journal of protistology}, volume = {64}, number = {}, pages = {54-71}, doi = {10.1016/j.ejop.2018.03.004}, pmid = {29674178}, issn = {1618-0429}, mesh = {Animals ; Biological Evolution ; DNA, Protozoan/genetics ; Fresh Water ; Oligohymenophorea/*classification/cytology/genetics/*physiology ; *Phylogeny ; RNA, Ribosomal, 18S/genetics ; Species Specificity ; Symbiosis ; Turbellaria/*parasitology ; }, abstract = {Morphology, systematic position and time-calibrated phylogeny of Haptophrya planariarum were investigated. This endosymbiont of freshwater turbellarians is characterized by: (i) a length of about 200-900 μm; (ii) a campanulate to truncate claviform body carrying an anterior adhesive sucker; (iii) an ellipsoidal macronucleus localized in the rear body end; (iv) a contractile canal extending along the dorsal margin; and (v) usually more than 150 meridional ciliary rows, a horseshoe-shaped suture line along the sucker, and two inconspicuous secant systems at lateral ends of the suture line. In 18S rRNA gene phylogenies, astomes were depicted as a non-monophyletic group within the scuticociliate clade, whereby H. planariarum clustered with the loxocephalid genus Dexiotricha. After considering morphological evidence, statistical tree topology tests and evolutionary distances, we find astomes as a distinct group that evolved from a free-living scuticociliate ancestor in the early Paleozoic. Molecular clock analyses indicated that astomes living in annelids diverged from those inhabiting turbellarians within about 50 Ma during the Late Cambrian and the Upper Ordovician. This comparatively short time span might have not sufficed for fixation of molecular synapomorphies in the 18S rRNA gene and/or they might have been erased by substitutions during the almost 500 Ma-long evolutionary history of astomes.}, }
@article {pmid29670598, year = {2018}, author = {Toro, N and Martínez-Abarca, F and Molina-Sánchez, MD and García-Rodríguez, FM and Nisa-Martínez, R}, title = {Contribution of Mobile Group II Introns to Sinorhizobium meliloti Genome Evolution.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {627}, pmid = {29670598}, issn = {1664-302X}, abstract = {Mobile group II introns are ribozymes and retroelements that probably originate from bacteria. Sinorhizobium meliloti, the nitrogen-fixing endosymbiont of legumes of genus Medicago, harbors a large number of these retroelements. One of these elements, RmInt1, has been particularly successful at colonizing this multipartite genome. Many studies have improved our understanding of RmInt1 and phylogenetically related group II introns, their mobility mechanisms, spread and dynamics within S. meliloti and closely related species. Although RmInt1 conserves the ancient retroelement behavior, its evolutionary history suggests that this group II intron has played a role in the short- and long-term evolution of the S. meliloti genome. We will discuss its proposed role in genome evolution by controlling the spread and coexistence of potentially harmful mobile genetic elements, by ectopic transposition to different genetic loci as a source of early genomic variation and by generating sequence variation after a very slow degradation process, through intron remnants that may have continued to evolve, contributing to bacterial speciation.}, }
@article {pmid29669904, year = {2018}, author = {Hayashi, M and Nomura, M and Kageyama, D}, title = {Rapid comeback of males: evolution of male-killer suppression in a green lacewing population.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1877}, pages = {}, pmid = {29669904}, issn = {1471-2954}, mesh = {Animals ; *Biological Evolution ; Cell Nucleus/genetics ; Female ; *Genetic Variation ; Insecta/genetics/*microbiology/*physiology ; Japan ; Male ; *Sex Ratio ; Spiroplasma/*physiology ; Symbiosis ; }, abstract = {Evolutionary theory predicts that the spread of cytoplasmic sex ratio distorters leads to the evolution of host nuclear suppressors, although there are extremely few empirical observations of this phenomenon. Here, we demonstrate that a nuclear suppressor of a cytoplasmic male killer has spread rapidly in a population of the green lacewing Mallada desjardinsi An M. desjardinsi population, which was strongly female-biased in 2011 because of a high prevalence of the male-killing Spiroplasma endosymbiont, had a sex ratio near parity in 2016, despite a consistent Spiroplasma prevalence. Most of the offspring derived from individuals collected in 2016 had 1 : 1 sex ratios in subsequent generations. Contrastingly, all-female or female-biased broods appeared frequently from crossings of these female offspring with males derived from a laboratory line founded by individuals collected in 2011. These results suggest near-fixation of a nuclear suppressor against male killing in 2016 and reject the notion that a non-male-killing Spiroplasma variant has spread in the population. Consistently, no significant difference was detected in mitochondrial haplotype variation between 2011 and 2016. These findings, and earlier findings in the butterfly Hypolimnas bolina in Samoa, suggest that these quick events of male recovery occur more commonly than is generally appreciated.}, }
@article {pmid29659807, year = {2018}, author = {Floriano, AM and Castelli, M and Krenek, S and Berendonk, TU and Bazzocchi, C and Petroni, G and Sassera, D}, title = {The Genome Sequence of "Candidatus Fokinia solitaria": Insights on Reductive Evolution in Rickettsiales.}, journal = {Genome biology and evolution}, volume = {10}, number = {4}, pages = {1120-1126}, pmid = {29659807}, issn = {1759-6653}, mesh = {Animals ; Chromosome Mapping ; Citric Acid Cycle/genetics ; Cytoplasm/genetics ; *Evolution, Molecular ; Genome, Bacterial/genetics ; Paramecium/*genetics/microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsieae/*genetics ; Symbiosis/genetics ; }, abstract = {"Candidatus Fokinia solitaria" is an obligate intracellular endosymbiont of a unicellular eukaryote, a ciliate of the genus Paramecium. Here, we present the genome sequence of this bacterium and subsequent analysis. Phylogenomic analysis confirmed the previously reported positioning of the symbiont within the "Candidatus Midichloriaceae" family (order Rickettsiales), as well as its high sequence divergence from other members of the family, indicative of fast sequence evolution. Consistently with this high evolutionary rate, a comparative genomic analysis revealed that the genome of this symbiont is the smallest of the Rickettsiales to date. The reduced genome does not present flagellar genes, nor the pathway for the biosynthesis of lipopolysaccharides (present in all the other so far sequenced members of the family "Candidatus Midichloriaceae") or genes for the Krebs cycle (present, although not always complete, in Rickettsiales). These results indicate an evolutionary trend toward a stronger dependence on the host, in comparison with other members of the family. Two alternative scenarios are compatible with our results; "Candidatus Fokinia solitaria" could be either a recently evolved, vertically transmitted mutualist, or a parasite with a high host-specificity.}, }
@article {pmid29657018, year = {2018}, author = {Kramer, L and Crosara, S and Gnudi, G and Genchi, M and Mangia, C and Viglietti, A and Quintavalla, C}, title = {Wolbachia, doxycycline and macrocyclic lactones: New prospects in the treatment of canine heartworm disease.}, journal = {Veterinary parasitology}, volume = {254}, number = {}, pages = {95-97}, doi = {10.1016/j.vetpar.2018.03.005}, pmid = {29657018}, issn = {1873-2550}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Dirofilaria immitis/drug effects ; Dirofilariasis/*drug therapy/parasitology ; Dog Diseases/*drug therapy/parasitology ; Dogs ; Doxycycline/*therapeutic use ; Drug Combinations ; Filaricides/*therapeutic use ; Lactones/*therapeutic use ; Macrocyclic Compounds/therapeutic use ; Wolbachia/*drug effects ; }, abstract = {Melarsomine dihydrochloride (Immiticide®, Merial) is the only approved adulticidal drug for the treatment of canine heartworm disease (HWD). However, in cases where arsenical therapy is not possible or is contraindicated, a monthly heartworm preventive along with doxycycline for a 4-week period, which targets the bacterial endosymbiont Wolbachia, might be considered. There are published reports on the efficacy of ivermectin and doxycycline in both experimentally and naturally infected dogs, but no data on the use of other macrocyclic lactones (MLs) with a similar treatment regime. Preliminary results of studies in dogs show that a topical formulation of moxidectin, the only ML currently registered as a microfilaricide, is also adulticidal when combined with doxycycline. It is not yet known if the efficacy of these combination therapies is due to pharmacokinetic synergism. A recent study showed that serum levels of doxycycline in dogs treated with the combination protocol were not statistically different compared to dogs treated with doxycycline alone. However, lungs from dogs treated with the combination therapy showed a marked reduction in T regulatory cells, indicating that treatment efficacy may be due to a heightened immune response against the parasite. Further studies are necessary to evaluate the long-term clinical outcome of combination protocols and to establish the most efficient treatment for HWD in dogs.}, }
@article {pmid29653599, year = {2018}, author = {Li, LH and Zhang, Y and Zhu, D}, title = {Effects of antibiotic treatment on the fecundity of Rhipicephalus haemaphysaloides ticks.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {242}, pmid = {29653599}, issn = {1756-3305}, support = {2016YFC1202001 and No.2016YFC1200500//National Key Research and Development Program of China/International ; No. GWIV-29//the fourth round of Three-Year Public Health Action Plan 2015-2017/International ; No.201202019//the Special Fund for Health Research in the Public Interest China/International ; 2017BSQD52//the Scientific Research Foundation for Doctors of Weifang Medical College/International ; }, mesh = {Animals ; Anti-Bacterial Agents/*administration &amp; dosage/adverse effects/therapeutic use ; Coxiella/genetics ; DNA, Ribosomal/genetics ; Female ; Fertility/drug effects ; Male ; Microbial Consortia/drug effects/*genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus/*drug effects/genetics/microbiology/*physiology ; Rickettsia/genetics ; Sequence Analysis, DNA ; Symbiosis/drug effects ; }, abstract = {BACKGROUND: Endosymbiotic bacteria inhabit a variety of arthropods including ticks and may have multiple effects on the host's survival, reproduction or pathogen acquisition and transmission. Rhipicephalus haemaphysaloides is one of the most widely distributed tick species in China. The symbiotic bacteria composition and their impacts to R. haemaphysaloides ticks have not been studied. The present study investigated the composition of microbial community in R. haemaphysaloides ticks and then assessed the effects of endosymbionts on the host's fecundity by antibiotic treatment experiments.<br><br>METHODS: The microbial population of female and male R. haemaphysaloides ticks was analyzed using Illumina Miseq sequencing of 16S rRNA gene. Thirty engorged female ticks were then randomly divided into five groups and injected with ampicillin, ciprofloxacin, kanamycin, tetracycline, or phosphate-buffered solution (PBS), respectively. Effects of antibiotic treatments on maternal oviposition, egg hatching and density of endosymbionts were evaluated.<br><br>RESULTS: Illumina Miseq sequencing showed that Coxiella and Rickettsia were the predominant bacterial genera inhabiting R. haemaphysaloides ticks. Antibiotic treatment experiments found that kanamycin reduced the density of Coxiella-like endosymbiont (Coxiella-LE hereafter) in eggs, ciprofloxacin reduced the density of Rickettsia-like endosymbiont (Rickettsia-LE), and tetracycline had effect on both endosymbionts, while ampicillin affected neither. Meanwhile hatching rates of eggs were observed to decrease greatly in the kanamycin or tetracycline-treated group but maintained in the ampicillin or ciprofloxacin-treated group. Furthermore, the reduced hatching rates were found to be associated with density of Coxiella-LE in eggs.<br><br>CONCLUSIONS: The findings indicate that Coxiella-LE is essential for the reproduction of R. haemaphysaloides ticks, and that kanamycin can be used to study the role of Coxiella-LE on ticks.}, }
@article {pmid29652934, year = {2018}, author = {Ammar, ED and Hall, DG and Hosseinzadeh, S and Heck, M}, title = {The quest for a non-vector psyllid: Natural variation in acquisition and transmission of the huanglongbing pathogen 'Candidatus Liberibacter asiaticus' by Asian citrus psyllid isofemale lines.}, journal = {PloS one}, volume = {13}, number = {4}, pages = {e0195804}, pmid = {29652934}, issn = {1932-6203}, mesh = {Animals ; Citrus/*microbiology ; Female ; Hemiptera/*microbiology/*physiology ; Insect Vectors/*microbiology ; Male ; Plant Diseases/*microbiology ; *Rhizobiaceae ; Symbiosis ; }, abstract = {Genetic variability in insect vectors is valuable to study vector competence determinants and to select non-vector populations that may help reduce the spread of vector-borne pathogens. We collected and tested vector competency of 15 isofemale lines of Asian citrus psyllid, Diaphorina citri, vector of 'Candidatus Liberibacter asiaticus' (CLas). CLas is associated with huanglongbing (citrus greening), the most serious citrus disease worldwide. D. citri adults were collected from orange jasmine (Murraya paniculata) hedges in Florida, and individual pairs (females and males) were caged on healthy Murraya plants for egg laying. The progeny from each pair that tested CLas-negative by qPCR were maintained on Murraya plants and considered an isofemale line. Six acquisition tests on D. citri adults that were reared as nymphs on CLas-infected citrus, from various generations of each line, were conducted to assess their acquisition rates (percentage of qPCR-positive adults). Three lines with mean acquisition rates of 28 to 32%, were classified as 'good' acquirers and three other lines were classified as 'poor' acquirers, with only 5 to 8% acquisition rates. All lines were further tested for their ability to inoculate CLas by confining CLas-exposed psyllids for one week onto healthy citrus leaves (6-10 adults/leaf/week), and testing the leaves for CLas by qPCR. Mean inoculation rates were 19 to 28% for the three good acquirer lines and 0 to 3% for the three poor acquirer lines. Statistical analyses indicated positive correlations between CLas acquisition and inoculation rates, as well as between CLas titer in the psyllids and CLas acquisition or inoculation rates. Phenotypic and molecular characterization of one of the good and one of the poor acquirer lines revealed differences between them in color morphs and hemocyanin expression, but not the composition of bacterial endosymbionts. Understanding the genetic architecture of CLas transmission will enable the development of new tools for combating this devastating citrus disease.}, }
@article {pmid29650391, year = {2018}, author = {Dietel, AK and Kaltenpoth, M and Kost, C}, title = {Convergent Evolution in Intracellular Elements: Plasmids as Model Endosymbionts.}, journal = {Trends in microbiology}, volume = {26}, number = {9}, pages = {755-768}, doi = {10.1016/j.tim.2018.03.004}, pmid = {29650391}, issn = {1878-4380}, mesh = {*Bacteria/genetics/metabolism ; Chromosome Segregation ; Cytoplasm ; DNA Transposable Elements ; Eukaryota ; Evolution, Molecular ; Gene Transfer, Horizontal ; Host Microbial Interactions/genetics/physiology ; Mutation ; *Plasmids/genetics/metabolism ; *Symbiosis/genetics/physiology ; }, abstract = {Endosymbionts are organisms that live inside the cells of other species. This lifestyle is ubiquitous across the tree of life and is featured by unicellular eukaryotes, prokaryotes, and by extrachromosomal genetic elements such as plasmids. Given that all of these elements dwell in the cytoplasm of their host cell, they should be subject to similar selection pressures. Here we show that strikingly similar features have evolved in both bacterial endosymbionts and plasmids. Since host and endosymbiont are often metabolically tightly intertwined, they are difficult to disentangle experimentally. We propose that using plasmids as tractable model systems can help to solve this problem, thus allowing fundamental questions to be experimentally addressed about the ecology and evolution of endosymbiotic interactions.}, }
@article {pmid29642956, year = {2018}, author = {Silva, FM and Kostygov, AY and Spodareva, VV and Butenko, A and Tossou, R and Lukeš, J and Yurchenko, V and Alves, JMP}, title = {The reduced genome of Candidatus Kinetoplastibacterium sorsogonicusi, the endosymbiont of Kentomonas sorsogonicus (Trypanosomatidae): loss of the haem-synthesis pathway.}, journal = {Parasitology}, volume = {145}, number = {10}, pages = {1287-1293}, doi = {10.1017/S003118201800046X}, pmid = {29642956}, issn = {1469-8161}, mesh = {Betaproteobacteria/drug effects/*genetics/growth &amp; development ; Biosynthetic Pathways ; *Genome, Bacterial ; Heme/*metabolism/pharmacology ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; Trypanosomatina/*microbiology ; }, abstract = {Trypanosomatids of the genera Angomonas and Strigomonas (subfamily Strigomonadinae) have long been known to contain intracellular beta-proteobacteria, which provide them with many important nutrients such as haem, essential amino acids and vitamins. Recently, Kentomonas sorsogonicus, a divergent member of Strigomonadinae, has been described. Herein, we characterize the genome of its endosymbiont, Candidatus Kinetoplastibacterium sorsogonicusi. This genome is completely syntenic with those of other known Ca. Kinetoplastibacterium spp., but more reduced in size (~742 kb, compared with 810-833 kb, respectively). Gene losses are not concentrated in any hot-spots but are instead distributed throughout the genome. The most conspicuous loss is that of the haem-synthesis pathway. For long, removing haemin from the culture medium has been a standard procedure in cultivating trypanosomatids isolated from insects; continued growth was considered as an evidence of endosymbiont presence. However, we demonstrate that, despite bearing the endosymbiont, K. sorsogonicus cannot grow in culture without haem. Thus, the traditional test cannot be taken as a reliable criterion for the absence or presence of endosymbionts in trypanosomatid flagellates. It remains unclear why the ability to synthesize such an essential compound was lost in Ca. K. sorsogonicusi, whereas all other known bacterial endosymbionts of trypanosomatids retain them.}, }
@article {pmid29641562, year = {2018}, author = {Asad, S and Hussain, M and Hugo, L and Osei-Amo, S and Zhang, G and Watterson, D and Asgari, S}, title = {Suppression of the pelo protein by Wolbachia and its effect on dengue virus in Aedes aegypti.}, journal = {PLoS neglected tropical diseases}, volume = {12}, number = {4}, pages = {e0006405}, pmid = {29641562}, issn = {1935-2735}, mesh = {Aedes/genetics/metabolism/*microbiology/*virology ; Animals ; Dengue Virus/*physiology ; Down-Regulation ; Female ; Insect Proteins/*genetics/metabolism ; Insect Vectors/*microbiology/*virology ; MicroRNAs/genetics/metabolism ; Nuclear Proteins/*genetics/metabolism ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {The endosymbiont Wolbachia is known to block replication of several important arboviruses, including dengue virus (DENV), in the mosquito vector Aedes aegypti. So far, the exact mechanism of this viral inhibition is not fully understood. A recent study in Drosophila melanogaster has demonstrated an interaction between the pelo gene and Drosophila C virus. In this study, we explored the possible involvement of the pelo protein, that is involved in protein translation, in Wolbachia-mediated antiviral response and mosquito-DENV interaction. We found that pelo is upregulated during DENV replication and its silencing leads to reduced DENV virion production suggesting that it facilities DENV replication. However, in the presence of Wolbachia, specifically in female mosquitoes, the pelo protein is downregulated and its subcellular localization is altered, which could contribute to reduction in DENV replication in Ae. aegypti. In addition, we show that the microRNA aae-miR-2940-5p, whose abundance is highly enriched in Wolbachia-infected mosquitoes, might mediate regulation of pelo. Our data reveals identification of pelo as a host factor that is positively involved in DENV replication, and its suppression in the presence of Wolbachia may contribute to virus blocking exhibited by the endosymbiont.}, }
@article {pmid29637886, year = {2018}, author = {Llop, P and Latorre, A and Moya, A}, title = {Experimental Epidemiology of Antibiotic Resistance: Looking for an Appropriate Animal Model System.}, journal = {Microbiology spectrum}, volume = {6}, number = {1}, pages = {}, doi = {10.1128/microbiolspec.MTBP-0007-2016}, pmid = {29637886}, issn = {2165-0497}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Cell Membrane/metabolism ; Cockroaches/*microbiology ; *Computer Simulation ; Drug Resistance, Multiple, Bacterial/*genetics ; Gastrointestinal Microbiome/*drug effects/genetics ; Gastrointestinal Tract/*microbiology ; Genes, Bacterial/genetics ; Humans ; *Models, Animal ; Plasmids/genetics ; }, abstract = {Antibiotic resistance is recognized as one of the major challenges in public health. The global spread of antibiotic resistance is the consequence of a constant flow of information across multi-hierarchical interactions, involving cellular (clones), subcellular (resistance genes located in plasmids, transposons, and integrons), and supracellular (clonal complexes, genetic exchange communities, and microbiotic ensembles) levels. In order to study such multilevel complexity, we propose to establish an experimental epidemiology model for the transmission of antibiotic resistance with the cockroach Blatella germanica. This paper reports the results of five types of preliminary experiments with B. germanica populations that allow us to conclude that this animal is an appropriate model for experimental epidemiology: (i) the composition, transmission, and acquisition of gut microbiota and endosymbionts; (ii) the effect of different diets on gut microbiota; (iii) the effect of antibiotics on host fitness; (iv) the evaluation of the presence of antibiotic resistance genes in natural- and lab-reared populations; and (v) the preparation of plasmids harboring specific antibiotic resistance genes. The basic idea is to have populations with higher and lower antibiotic exposure, simulating the hospital and the community, respectively, and with a certain migration rate of insects between populations. In parallel, we present a computational model based on P-membrane computing that will mimic the experimental system of antibiotic resistance transmission. The proposal serves as a proof of concept for the development of more-complex population dynamics of antibiotic resistance transmission that are of interest in public health, which can help us evaluate procedures and design appropriate interventions in epidemiology.}, }
@article {pmid29636736, year = {2018}, author = {Paniagua Voirol, LR and Frago, E and Kaltenpoth, M and Hilker, M and Fatouros, NE}, title = {Bacterial Symbionts in Lepidoptera: Their Diversity, Transmission, and Impact on the Host.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {556}, pmid = {29636736}, issn = {1664-302X}, abstract = {The insect's microbiota is well acknowledged as a "hidden" player influencing essential insect traits. The gut microbiome of butterflies and moths (Lepidoptera) has been shown to be highly variable between and within species, resulting in a controversy on the functional relevance of gut microbes in this insect order. Here, we aim to (i) review current knowledge on the composition of gut microbial communities across Lepidoptera and (ii) elucidate the drivers of the variability in the lepidopteran gut microbiome and provide an overview on (iii) routes of transfer and (iv) the putative functions of microbes in Lepidoptera. To find out whether Lepidopterans possess a core gut microbiome, we compared studies of the microbiome from 30 lepidopteran species. Gut bacteria of the Enterobacteriaceae, Bacillaceae, and Pseudomonadaceae families were the most widespread across species, with Pseudomonas, Bacillus, Staphylococcus, Enterobacter, and Enterococcus being the most common genera. Several studies indicate that habitat, food plant, and age of the host insect can greatly impact the gut microbiome, which contributes to digestion, detoxification, or defense against natural enemies. We mainly focus on the gut microbiome, but we also include some examples of intracellular endosymbionts. These symbionts are present across a broad range of insect taxa and are known to exert different effects on their host, mostly including nutrition and reproductive manipulation. Only two intracellular bacteria genera (Wolbachia and Spiroplasma) have been reported to colonize reproductive tissues of Lepidoptera, affecting their host's reproduction. We explore routes of transmission of both gut microbiota and intracellular symbionts and have found that these microbes may be horizontally transmitted through the host plant, but also vertically via the egg stage. More detailed knowledge about the functions and plasticity of the microbiome in Lepidoptera may provide novel leads for the control of lepidopteran pest species.}, }
@article {pmid29632192, year = {2018}, author = {Hu, H and Nemecz, &#xc1; and Van Renterghem, C and Fourati, Z and Sauguet, L and Corringer, PJ and Delarue, M}, title = {Crystal structures of a pentameric ion channel gated by alkaline pH show a widely open pore and identify a cavity for modulation.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {17}, pages = {E3959-E3968}, pmid = {29632192}, issn = {1091-6490}, mesh = {Allosteric Regulation ; Bacterial Proteins/antagonists &amp; inhibitors/*chemistry ; Crystallography, X-Ray ; Gammaproteobacteria/*enzymology ; Hydrogen-Ion Concentration ; Ligand-Gated Ion Channels/antagonists &amp; inhibitors/*chemistry ; Quaternary Ammonium Compounds/chemistry ; }, abstract = {Pentameric ligand-gated ion channels (pLGICs) constitute a widespread class of ion channels, present in archaea, bacteria, and eukaryotes. Upon binding of their agonists in the extracellular domain, the transmembrane pore opens, allowing ions to go through, via a gating mechanism that can be modulated by a number of drugs. Even though high-resolution structural information on pLGICs has increased in a spectacular way in recent years, both in bacterial and in eukaryotic systems, the structure of the open channel conformation of some intensively studied receptors whose structures are known in a nonactive (closed) form, such as Erwinia chrysanthemi pLGIC (ELIC), is still lacking. Here we describe a gammaproteobacterial pLGIC from an endo-symbiont of Tevnia jerichonana (sTeLIC), whose sequence is closely related to the pLGIC from ELIC with 28% identity. We provide an X-ray crystallographic structure at 2.3 Å in an active conformation, where the pore is found to be more open than any current conformation found for pLGICs. In addition, two charged restriction rings are present in the vestibule. Functional characterization shows sTeLIC to be a cationic channel activated at alkaline pH. It is inhibited by divalent cations, but not by quaternary ammonium ions, such as tetramethylammonium. Additionally, we found that sTeLIC is allosterically potentiated by aromatic amino acids Phe and Trp, as well as their derivatives, such as 4-bromo-cinnamate, whose cocrystal structure reveals a vestibular binding site equivalent to, but more deeply buried than, the one already described for benzodiazepines in ELIC.}, }
@article {pmid29629417, year = {2018}, author = {Heck, M}, title = {Insect Transmission of Plant Pathogens: a Systems Biology Perspective.}, journal = {mSystems}, volume = {3}, number = {2}, pages = {}, pmid = {29629417}, issn = {2379-5077}, abstract = {Insect-vectored pathogens pose one of the greatest threats to plant and animal, including human, health on a global scale. Few effective control strategies have been developed to thwart the transmission of any insect-transmitted pathogen. Most have negative impacts on the environment and human health and are unsustainable. Plant pathogen transmission by insect vectors involves a combination of coevolving biological players: plant hosts, insect vectors, plant pathogens, and bacterial endosymbionts harbored by the insect. Our ability to help growers to control vector-borne disease depends on our ability to generate pathogen- and/or disease-resistant crops by traditional or synthetic approaches and to block pathogen transmission by the insect vector. Systems biology studies have led to the reexamination of existing paradigms on how pathogens interact with insect vectors, including the bacterial symbionts, and have identified vector-pathogen interactions at the molecular and cellular levels for the development of novel transmission interdiction strategies.}, }
@article {pmid29618379, year = {2018}, author = {Guo, Y and Song, Z and Luo, L and Wang, Q and Zhou, G and Yang, D and Zhong, D and Zheng, X}, title = {Molecular evidence for new sympatric cryptic species of Aedes albopictus (Diptera: Culicidae) in China: A new threat from Aedes albopictus subgroup?.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {228}, pmid = {29618379}, issn = {1756-3305}, support = {31630011//National Natural Science Foundation of China (CN)/International ; 2013B021800042//Science and Technology Plan Project of Guangdong Province (CN)/International ; 2015A030313784//Natural Science Foundation of Guangdong Province (CN)/International ; }, mesh = {Aedes/*classification/genetics/*growth &amp; development/microbiology ; Animals ; China ; Cluster Analysis ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Electron Transport Complex IV/genetics ; *Genetic Variation ; *Genotype ; Mosquito Vectors/*classification/genetics/*growth &amp; development ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {BACKGROUND: Aedes (Stegomyia) albopictus (Skuse) is an indigenous species and the predominant vector of dengue fever in China. Understanding of genetic diversity and structure of the mosquito would facilitate dengue prevention and vector control. Sympatric cryptic species have been identified in the Ae. albopictus subgroup in Southeast Asia; however, little is known about the presence and distribution of cryptic species in China. This study aimed to examine the genetic diversity, evaluate potential new cryptic sibling species, and assess the prevalence of Wolbachia infections in field populations.<br><br>METHODS: Aedes adult female specimens were collected from five provinces in southern and central China during 2015-2016. Morphological identification was performed under dissection microscope. The mitochondrial DNA cytochrome c oxidase subunit 1 (cox1, DNA barcoding) locus and the ribosomal DNA internal transcribed spacer region 2 (ITS2) marker were used to examine the genetic variation, evaluate cryptic sibling species, and population structure in the field populations. Screening for the presence of Wolbachia was performed using multiplex PCR.<br><br>RESULTS: A total of 140 individual specimens with morphological characteristics similar to Ae. albopictus were sequenced for DNA barcoding. Among these, 129 specimens (92.1%) were confirmed and identified as Ae. albopictus. The remaining 11 specimens, from 2 provinces, were identified as 2 distinct sequence groups, which were confirmed by ITS2 marker sequencing, suggesting the existence of potential cryptic species of Ae. albopictus. In Ae. albopictus, we found significant genetic differentiation and population structure between populations collected from different climate zones. Medium to high frequencies of Wolbachia infections were observed in natural Ae. albopictus populations, whereas Wolbachia was infrequent or absent in cryptic species populations.<br><br>CONCLUSIONS: Our findings highlight the population differentiation by climate zone and the presence of novel, cryptic Aedes species in China. The low prevalence of Wolbachia infections in cryptic species populations could reflect either a recent invasion of Wolbachia in Ae. albopictus or different host immune responses to this symbiont in the cryptic species. The study provides useful information for vector control and host-symbiont coevolution. Further study is needed to investigate the potential for arbovirus infection and disease transmission in the emerged cryptic species.}, }
@article {pmid29611898, year = {2018}, author = {Okubo, T and Matsushita, M and Nakamura, S and Matsuo, J and Nagai, H and Yamaguchi, H}, title = {Acanthamoeba S13WT relies on its bacterial endosymbiont to backpack human pathogenic bacteria and resist Legionella infection on solid media.}, journal = {Environmental microbiology reports}, volume = {10}, number = {3}, pages = {344-354}, doi = {10.1111/1758-2229.12645}, pmid = {29611898}, issn = {1758-2229}, mesh = {Acanthamoeba/*microbiology ; Humans ; Legionella pneumophila/*growth &amp; development ; *Symbiosis ; }, abstract = {Soil-borne amoeba Acanthamoeba S13WT has an endosymbiotic relationship with an environmental Neochlamydia bacterial strain. However, regardless of extensive experiments in liquid media, the biological advantage of the symbiosis remained elusive. We therefore explored the role of the endosymbiont in predator-prey interactions on solid media. A mixed culture of the symbiotic or aposymbiotic amoebae and GFP-expressing Escherichia coli or Salmonella Enteritidis was spotted onto the centre of a LB or B-CYE agar plate preinoculated with a ring of mCherry-expressing Legionella pneumophila (Legionella 'wall'). The spread of the amoebae on the plate was assessed using a fluorescence imaging system or scanning electron microscopy. As a result, in contrast to the aposymbiotic amoebae, the symbiotic amoebae backpacked these GFP-expressing bacteria and formed flower-like fluorescence patterns in an anticlockwise direction. Other bacteria (Pseudomonas aeruginosa and Stenotrophomonas maltophilia), but not Staphylococcus aureus, were also backpacked by the symbiotic amoebae on LB agar, although lacked the movement to anticlockwise direction. Furthermore, in contrast to the aposymbiotic amoebae, the symbiotic amoebae backpacking the E. coli broke through the Legionella 'wall' on B-CYE agar plates. Thus, we concluded that Acanthamoeba S13WT required the Neochlamydia endosymbiont to backpack human pathogenic bacteria and resist Legionella infection on solid agar.}, }
@article {pmid29610046, year = {2018}, author = {Nooroong, P and Trinachartvanit, W and Baimai, V and Ahantarig, A}, title = {Phylogenetic studies of bacteria (Rickettsia, Coxiella, and Anaplasma) in Amblyomma and Dermacentor ticks in Thailand and their co-infection.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {4}, pages = {963-971}, doi = {10.1016/j.ttbdis.2018.03.027}, pmid = {29610046}, issn = {1877-9603}, mesh = {Anaplasma/*genetics/isolation &amp; purification ; Anaplasmosis/epidemiology/microbiology ; Animals ; Coinfection/epidemiology/*microbiology ; Coxiella/*genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Dermacentor/microbiology ; Female ; Gram-Negative Bacterial Infections/epidemiology/microbiology ; Humans ; Ixodidae/*microbiology ; Male ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*genetics/isolation &amp; purification ; Rickettsia Infections/epidemiology/microbiology ; Spotted Fever Group Rickettsiosis/epidemiology/microbiology ; Thailand/epidemiology ; }, abstract = {In this study, we attempted to detect Rickettsia, Coxiella and Anaplasma bacteria in one hundred and fourteen-Dermacentor and thirty three-Amblyomma unfed adult ticks that were collected from under leaves along animal trails at different places across Thailand. PCR amplification was used to identify bacterial infection with general conserved sequences of bacteria. The results revealed single infection in Amblyomma testudinarium ticks with Rickettsia (24%) and Coxiella (6%). Anaplasma bacteria were often detected in Dermacentor auratus ticks (32%). Coxiella spp. were detected in Dermacentor atrosignatus (6%) and D. auratus ticks (3%) in this study. Moreover, we found co-infection by Coxiella and Rickettsia bacteria (39%) in Am. testudinarium. In contrast, D. atrosignatus ticks were co-infected with Coxiella and Anaplasma bacteria (3%) and Dermacentor compactus ticks were co-infected with Rickettsia and Anaplasma spp. (25%). Interestingly, Am. testudinarium ticks (12%) were found for the first time to exhibit triple infection by these three bacteria. Phylogenetic studies showed the rickettsiae from ticks causing both single and multiple infections had sequence similarity with spotted fever group rickettsial strains, including Rickettsia massilliae, R. raoultii and R. tamurae. In addition, the phylogenetic analysis of the 16S rRNA gene of Coxiella bacteria showed that they were closely grouped with Coxiella endosymbionts in both Dermacentor and Amblyomma. Moreover, the Anaplasma identified in a D. auratus tick was grouped in the same clade with the pathogenic bacterium Anaplasma phagocytophilum. Bacterial co-infections in Dermacentor and Amblyomma ticks may cause co-transmission of some tick-borne microorganisms (pathogen and endosymbiont, whether enhance or reduce) in humans and animals and they could affect medical and veterinary health.}, }
@article {pmid29608732, year = {2018}, author = {Hönigschmid, P and Bykova, N and Schneider, R and Ivankov, D and Frishman, D}, title = {Evolutionary Interplay between Symbiotic Relationships and Patterns of Signal Peptide Gain and Loss.}, journal = {Genome biology and evolution}, volume = {10}, number = {3}, pages = {928-938}, pmid = {29608732}, issn = {1759-6653}, mesh = {Enterobacteriaceae/genetics ; *Evolution, Molecular ; Genome, Bacterial/genetics ; *Phylogeny ; Protein Sorting Signals/*genetics ; Symbiosis/*genetics ; }, abstract = {Can orthologous proteins differ in terms of their ability to be secreted? To answer this question, we investigated the distribution of signal peptides within the orthologous groups of Enterobacterales. Parsimony analysis and sequence comparisons revealed a large number of signal peptide gain and loss events, in which signal peptides emerge or disappear in the course of evolution. Signal peptide losses prevail over gains, an effect which is especially pronounced in the transition from the free-living or commensal to the endosymbiotic lifestyle. The disproportionate decline in the number of signal peptide-containing proteins in endosymbionts cannot be explained by the overall reduction of their genomes. Signal peptides can be gained and lost either by acquisition/elimination of the corresponding N-terminal regions or by gradual accumulation of mutations. The evolutionary dynamics of signal peptides in bacterial proteins represents a powerful mechanism of functional diversification.}, }
@article {pmid29606099, year = {2018}, author = {Qiu, H and Rossoni, AW and Weber, APM and Yoon, HS and Bhattacharya, D}, title = {Unexpected conservation of the RNA splicing apparatus in the highly streamlined genome of Galdieria sulphuraria.}, journal = {BMC evolutionary biology}, volume = {18}, number = {1}, pages = {41}, pmid = {29606099}, issn = {1471-2148}, support = {PJT200620//Ministry of Oceans and Fisheries of Korea/International ; EF1416785//National Science Foundation/International ; }, mesh = {Amino Acid Sequence ; Conserved Sequence/*genetics ; Eukaryota/genetics ; Evolution, Molecular ; *Genome ; Introns/genetics ; RNA Splicing/*genetics ; RNA, Messenger/genetics/metabolism ; Rhodophyta/*genetics ; Spliceosomes/metabolism ; }, abstract = {BACKGROUND: Genome reduction in intracellular pathogens and endosymbionts is usually compensated by reliance on the host for energy and nutrients. Free-living taxa with reduced genomes must however evolve strategies for generating functional diversity to support their independent lifestyles. An emerging model for the latter case is the Rhodophyta (red algae) that comprises an ecologically widely distributed, species-rich phylum. Red algae have undergone multiple phases of significant genome reduction, including extremophilic unicellular taxa with limited nuclear gene inventories that must cope with hot, highly acidic environments.<br><br>RESULTS: Using genomic data from eight red algal lineages, we identified 155 spliceosomal machinery (SM)-associated genes that were putatively present in the red algal common ancestor. This core SM gene set is most highly conserved in Galdieria species (150 SM genes) and underwent differing levels of gene loss in other examined red algae (53-145 SM genes). Surprisingly, the high SM conservation in Galdieria sulphuraria coincides with the enrichment of spliceosomal introns in this species (2 introns/gene) in comparison to other red algae (<&#x2009;0.34 introns/gene). Spliceosomal introns in G. sulphuraria undergo alternatively splicing, including many that are differentially spliced upon changes in culture temperature.<br><br>CONCLUSIONS: Our work reveals the unique nature of G. sulphuraria among red algae with respect to the conservation of the spliceosomal machinery and introns. We discuss the possible implications of these findings in the highly streamlined genome of this free-living eukaryote.}, }
@article {pmid29603499, year = {2018}, author = {Mariño, YA and Ospina, OE and Verle Rodrigues, JC and Bayman, P}, title = {High diversity and variability in the bacterial microbiota of the coffee berry borer (Coleoptera: Curculionidae), with emphasis on Wolbachia.}, journal = {Journal of applied microbiology}, volume = {125}, number = {2}, pages = {528-543}, doi = {10.1111/jam.13768}, pmid = {29603499}, issn = {1365-2672}, mesh = {Animals ; Coffea/*parasitology ; DNA, Bacterial/analysis/genetics ; Microbiota/*genetics ; Weevils/*microbiology ; Wolbachia/*genetics ; }, abstract = {AIMS: Variation in microbiota of the coffee berry borer (CBB) Hypothenemus hampei was studied. Diversity, structure and function of bacterial communities were compared between eggs vs adults, CBBs from shade coffee vs sun coffee, CBBs from the field vs raised in the laboratory, and CBBs with and without the antibiotic tetracycline.<br><br>METHODS AND RESULTS: We sequenced the region V4 of the gene 16 S rRNA. Pseudomonadaceae and Enterobacteriaceae, particularly Pseudomonas and Pantoea, dominated microbiotas of the CBB. Comparative functional inferences with PICRUSt suggested that samples from the field were enriched for genes involved in carbohydrate and protein digestion and absorption, while laboratory-reared samples were higher in genes for melanization and caffeine metabolism.<br><br>CONCLUSIONS: Microbiotas of the CBB were diverse and dominated by the genus Pseudomonas, several species of which have been previously associated with caffeine degradation in this insect. Wolbachia was the only endosymbiont detected with known ability to manipulate host reproduction.<br><br>This study demonstrates that stage of development and origin of samples affected the structure and function of the CBB's bacterial communities. This is the first attempt to predict functional significance of the CBB microbiota in nutrition, reproduction and defence.}, }
@article {pmid29599150, year = {2018}, author = {Ramaiah, A and Dasch, GA}, title = {Genome Sequence of Coxiella-Like Endosymbiont Strain CLE-RmD, a Bacterial Agent in the Cattle Tick (Rhipicephalus microplus) Deutsch Strain.}, journal = {Genome announcements}, volume = {6}, number = {13}, pages = {}, pmid = {29599150}, issn = {2169-8287}, abstract = {We report a partial genome sequence for the Coxiella-like endosymbiont strain CLE-RmD, assembled from metagenomics data obtained from the southern cattle tick (Rhipicephalus microplus) Deutsch strain.}, }
@article {pmid29596449, year = {2018}, author = {Teixeira, MA and Sela, N and Atamian, HS and Bao, E and Chaudhary, R and MacWilliams, J and He, J and Mantelin, S and Girke, T and Kaloshian, I}, title = {Sequence analysis of the potato aphid Macrosiphum euphorbiae transcriptome identified two new viruses.}, journal = {PloS one}, volume = {13}, number = {3}, pages = {e0193239}, pmid = {29596449}, issn = {1932-6203}, support = {S10 OD016290/OD/NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/*virology ; *Gene Expression Profiling ; Gene Ontology ; Molecular Sequence Annotation ; Plant Viruses/*genetics/*isolation &amp; purification/physiology ; *Sequence Analysis ; Viral Proteins/chemistry/genetics ; }, abstract = {The potato aphid, Macrosiphum euphorbiae, is an important agricultural pest that causes economic losses to potato and tomato production. To establish the transcriptome for this aphid, RNA-Seq libraries constructed from aphids maintained on tomato plants were used in Illumina sequencing generating 52.6 million 75-105 bp paired-end reads. The reads were assembled using Velvet/Oases software with SEED preprocessing resulting in 22,137 contigs with an N50 value of 2,003bp. After removal of contigs from tomato host origin, 20,254 contigs were annotated using BLASTx searches against the non-redundant protein database from the National Center for Biotechnology Information (NCBI) as well as IntereProScan. This identified matches for 74% of the potato aphid contigs. The highest ranking hits for over 12,700 contigs were against the related pea aphid, Acyrthosiphon pisum. Gene Ontology (GO) was used to classify the identified M. euphorbiae contigs into biological process, cellular component and molecular function. Among the contigs, sequences of microbial origin were identified. Sixty five contigs were from the aphid bacterial obligate endosymbiont Buchnera aphidicola origin and two contigs had amino acid similarities to viruses. The latter two were named Macrosiphum euphorbiae virus 2 (MeV-2) and Macrosiphum euphorbiae virus 3 (MeV-3). The highest sequence identity to MeV-2 had the Dysaphis plantaginea densovirus, while to MeV-3 is the Hubei sobemo-like virus 49. Characterization of MeV-2 and MeV-3 indicated that both are transmitted vertically from adult aphids to nymphs. MeV-2 peptides were detected in the aphid saliva and only MeV-2 and not MeV-3 nucleic acids were detected inside tomato leaves exposed to virus-infected aphids. However, MeV-2 nucleic acids did not persist in tomato leaf tissues, after clearing the plants from aphids, indicating that MeV-2 is likely an aphid virus.}, }
@article {pmid29587626, year = {2018}, author = {Schuler, H and Egan, SP and Hood, GR and Busbee, RW and Driscoe, AL and Ott, JR}, title = {Diversity and distribution of Wolbachia in relation to geography, host plant affiliation and life cycle of a heterogonic gall wasp.}, journal = {BMC evolutionary biology}, volume = {18}, number = {1}, pages = {37}, pmid = {29587626}, issn = {1471-2148}, support = {J-3527-B22//Austrian Science Fund/International ; }, mesh = {Animals ; Bayes Theorem ; DNA, Mitochondrial/genetics ; Electron Transport Complex IV/genetics ; Female ; *Genetic Variation ; Genetics, Population ; *Geography ; Haplotypes/genetics ; *Life Cycle Stages ; Male ; Phylogeny ; Quercus/*parasitology ; United States ; Wasps/*genetics/*microbiology ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {BACKGROUND: The maternally inherited endosymbiont Wolbachia is widespread in arthropods and nematodes and can play an important role in the ecology and evolution of its host through reproductive manipulation. Here, we survey Wolbachia in Belonocnema treatae, a widely distributed North American cynipid gall forming wasp that exhibits regional host specialization on three species of oaks and alternation of sexually and asexually reproducing generations. We investigated whether patterns of Wolbachia infection and diversity in B. treatae are associated with the insect's geographic distribution, host plant association, life cycle, and mitochondrial evolutionary history.<br><br>RESULTS: Screening of 463 individuals from 23 populations including sexual and asexual generations from all three host plants across the southern U.S. showed an average infection rate of 56% with three common Wolbachia strains: wTre1-3 and an additional rare variant wTre4. Phylogenetic analysis based on wsp showed that these strains are unrelated and likely independently inherited. We found no difference in Wolbachia infection frequency among host plant associated populations or between the asexual and sexual generations, or between males and females of the sexual generation. Partially incomplete Wolbachia transmission rates might explain the occurrence of uninfected individuals. A parallel analysis of the mitochondrial cytochrome oxidase I gene in B. treatae showed high mtDNA haplotype diversity in both infected and uninfected populations suggesting an ancestral infection by Wolbachia as well as a clear split between eastern and western B. treatae mtDNA clades with a sequence divergence of >&#x2009;6%. The strain wTre1 was present almost exclusively in the western clade while wTre2 and wTre3 occur almost exclusively in eastern populations. In contrast, the same strains co-occur as double-infections in Georgia and triple-infections in two populations in central Florida.<br><br>CONCLUSIONS: The diversity of Wolbachia across geographically and genetically distinct populations of B. treatae and the co-occurrence of the same strains within three populations highlights the complex infection dynamics in this system. Moreover, the association of distinct Wolbachia strains with mitochondrial haplotypes of its host in populations infected by different Wolbachia strains suggests a potential role of the endosymbiont in reproductive isolation in B. treatae.}, }
@article {pmid29575777, year = {2018}, author = {Wang, Y and Lu, J and Beattie, GA and Islam, MR and Om, N and Dao, HT and Van Nguyen, L and Zaka, SM and Guo, J and Tian, M and Deng, X and Tan, S and Holford, P and He, Y and Cen, Y}, title = {Phylogeography of Diaphorina citri (Hemiptera: Liviidae) and its primary endosymbiont, 'Candidatus Carsonella ruddii': an evolutionary approach to host-endosymbiont interaction.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.4917}, pmid = {29575777}, issn = {1526-4998}, abstract = {BACKGROUND: In insects, little is known about the co-evolution between their primary endosymbionts and hosts at the intraspecific level. This study examined co-diversification between the notorious agricultural pest Diaphorina citri and its primary endosymbionts (P-endosymbiont), 'Candidatus Carsonella ruddii' at the population level.<br><br>RESULTS: Maximum likelihood, haplotype network, principal components and Bayesian clustering identified three lineages for D. citri and its P-endosymbiont: a Western clade containing individuals from Pakistan, Bhutan (Phuentsholing), Vietnam (Son La), USA, Myanmar and China (Ruili, Yunnan); a Central clade, with accessions originating from Southwest China, Bhutan (Tsirang) and Bangladesh; and an Eastern clade containing individuals from Southeast Asia, and East and South China. A more diverse genetic structure was apparent in the host mitochondrial DNA than their P-endosymbionts; however, the two sets of data were strongly congruent.<br><br>CONCLUSION: This study provides evidence for the co-diversification of D. citri and its P-endosymbiont during the migration from South Asia to East and Southeast Asia. We also suggest that the P-endosymbiont may facilitate investigations into the genealogy and migration history of the host. The biogeography of D. citri and its P-endosymbiont indicated that D. citri colonized and underwent a secondary dispersal from South Asia to East and Southeast Asia. &#xa9; 2018 Society of Chemical Industry.}, }
@article {pmid29575448, year = {2018}, author = {Tsementzi, D and Castro Gordillo, J and Mahagna, M and Gottlieb, Y and Konstantinidis, KT}, title = {Comparison of closely related, uncultivated Coxiella tick endosymbiont population genomes reveals clues about the mechanisms of symbiosis.}, journal = {Environmental microbiology}, volume = {20}, number = {5}, pages = {1751-1764}, doi = {10.1111/1462-2920.14104}, pmid = {29575448}, issn = {1462-2920}, mesh = {Animals ; Base Sequence ; Coxiella/*genetics/*physiology ; *Genome, Bacterial ; Metagenomics ; *Phylogeny ; Symbiosis/*physiology ; Ticks/*microbiology ; }, abstract = {Understanding the symbiotic interaction between Coxiella-like endosymbionts (CLE) and their tick hosts is challenging due to lack of isolates and difficulties in tick functional assays. Here we sequenced the metagenome of a CLE population from wild Rhipicephalus sanguineus ticks (CRs) and compared it to the previously published genome of its close relative, CLE of R. turanicus (CRt). The tick hosts are closely related sympatric species, and their two endosymbiont genomes are highly similar with only minor differences in gene content. Both genomes encode numerous pseudogenes, consistent with an ongoing genome reduction process. In silico flux balance metabolic analysis (FBA) revealed the excess production of L-proline for both genomes, indicating a possible proline transport from Coxiella to the tick. Additionally, both CR genomes encode multiple copies of the proline/betaine transporter, proP gene. Modelling additional Coxiellaceae members including other tick CLE, did not identify proline as an excreted metabolite. Although both CRs and CRt genomes encode intact B vitamin synthesis pathway genes, which are presumed to underlay the mechanism of CLE-tick symbiosis, the FBA analysis indicated no changes for their products. Therefore, this study provides new testable hypotheses for the symbiosis mechanism and a better understanding of CLE genome evolution and diversity.}, }
@article {pmid29575366, year = {2018}, author = {Ivanov, V and Lee, KM and Mutanen, M}, title = {Mitonuclear discordance in wolf spiders: Genomic evidence for species integrity and introgression.}, journal = {Molecular ecology}, volume = {27}, number = {7}, pages = {1681-1695}, doi = {10.1111/mec.14564}, pmid = {29575366}, issn = {1365-294X}, mesh = {Animals ; Cell Nucleus/*genetics ; Electron Transport Complex IV/genetics ; Genetic Loci ; *Genome, Mitochondrial ; *Genomics ; Likelihood Functions ; Mitochondria/genetics ; Phylogeny ; Species Specificity ; Spiders/*genetics ; }, abstract = {Systematists and taxonomists have benefited greatly from the emergence of molecular methods. Species identification has become straightforward through DNA barcoding and the rapid build-up of massive DNA barcode reference libraries. In animals, mitonuclear discordance can significantly complicate the process of species identification and delimitation. The causes of mitonuclear discordance are either biological (e.g., introgression, incomplete lineage sorting, horizontal gene transfer androgenesis) or induced by operational factors (e.g., human error with specimen misidentification or incorrect species delimitation). Moreover, endosymbionts may play an important role in promoting fixation of mitochondrial genomes. Here, we study the mitonuclear discordance of wolf spiders species (Lycosidae) (independent cases from Alopecosa aculeata and Pardosa pullata groups) that share identical COI DNA barcodes. We approached the case utilizing double-digest restriction site-associated DNA sequencing (ddRADseq) to obtain and analyse genomic-scale data. Our results suggest that the observed cases of mitonuclear discordance are not due to operational reasons but result from biological processes. Further analysis indicated introgression and that incomplete lineage sorting is unlikely to have been responsible for the observed discrepancy. Additional survey of endosymbionts provided ideas on further research and their role in shaping mitochondrial DNA distribution patterns. Thus, ddRADseq grants an efficient way to study the taxonomy of problematic groups with insight into underlying evolutionary processes.}, }
@article {pmid29573202, year = {2018}, author = {Ren, SL and Li, YH and Ou, D and Guo, YJ and Qureshi, JA and Stansly, PA and Qiu, BL}, title = {Localization and dynamics of Wolbachia infection in Asian citrus psyllid Diaphorina citri, the insect vector of the causal pathogens of Huanglongbing.}, journal = {MicrobiologyOpen}, volume = {7}, number = {3}, pages = {e00561}, pmid = {29573202}, issn = {2045-8827}, mesh = {Animal Structures/microbiology ; Animals ; Asia ; Bacterial Load ; Female ; Hemiptera/*growth &amp; development/*microbiology ; In Situ Hybridization, Fluorescence ; Insect Vectors/*microbiology ; Male ; Nymphaea/microbiology ; Wolbachia/*isolation &amp; purification ; Zygote/microbiology ; }, abstract = {Wolbachia is a group of intracellular bacteria that infect a wide range of arthropods including the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. This insect is the vector of Candidatus Liberibacter asiaticus (CLas), the causal pathogen of Huanglongbing or citrus greening disease. Here, we investigated the localization pattern and infection dynamics of Wolbachia in different developmental stages of ACP. Results revealed that all developmental stages of ACP including egg, 1st-5th instar nymphs, and adults of both gender were infected with Wolbachia. FISH visualization of an ACP egg showed that Wolbachia moved from the egg stalk of newly laid eggs to a randomly distributed pattern throughout the egg prior to hatching. The infection rate varied between nymphal instars. The titers of Wolbachia in fourth and fifth instar nymphs were significantly higher than those in the first and second instar nymphs. Wolbachia were scattered in all nymphal stages, but with highest intensity in the U-shaped bacteriome located in the abdomen of the nymph. Wolbachia was confined to two symmetrical organizations in the abdomen of newly emerged female and male adults. The potential mechanisms of Wolbachia infection dynamics are discussed.}, }
@article {pmid29569277, year = {2018}, author = {Dincă, V and Bálint, Z and Vodă, R and Dapporto, L and Hebert, PDN and Vila, R}, title = {Use of genetic, climatic, and microbiological data to inform reintroduction of a regionally extinct butterfly.}, journal = {Conservation biology : the journal of the Society for Conservation Biology}, volume = {32}, number = {4}, pages = {828-837}, doi = {10.1111/cobi.13111}, pmid = {29569277}, issn = {1523-1739}, mesh = {Animals ; *Butterflies ; Conservation of Natural Resources ; DNA, Mitochondrial ; France ; Genetic Variation ; Haplotypes ; Phylogeny ; }, abstract = {Species reintroductions are increasingly used as means of mitigating biodiversity loss. Besides habitat quality at the site targeted for reintroduction, the choice of source population can be critical for success. The butterfly Melanargia russiae (Esper´s marbled white) was extirpated from Hungary over 100 years ago, and a reintroduction program has recently been approved. We used museum specimens of this butterfly, mitochondrial DNA data (mtDNA), endosymbiont screening, and climatic-similarity analyses to determine which extant populations should be used for its reintroduction. The species displayed 2 main mtDNA lineages across its range: 1 restricted to Iberia and southern France (Iberian lineage) and another found throughout the rest of its range (Eurasian lineage). These 2 lineages possessed highly divergent wsp alleles of the bacterial endosymbiont Wolbachia. The century-old Hungarian specimens represented an endemic haplotype belonging to the Eurasian lineage, differing by one mutation from the Balkan and eastern European populations. The Hungarian populations of M. russiae occurred in areas with a colder and drier climate relative to most sites with extant known populations. Our results suggest the populations used for reintroduction to Hungary should belong to the Eurasian lineage, preferably from eastern Ukraine (genetically close and living in areas with the highest climatic similarity). Materials stored in museum collections can provide unique opportunities to document historical genetic diversity and help direct conservation.}, }
@article {pmid29569154, year = {2018}, author = {Li, Y and Liu, X and Guo, H}, title = {Variations in Endosymbiont Infection Between Buprofezin-Resistant and Susceptible Strains of Laodelphax striatellus (Fallén).}, journal = {Current microbiology}, volume = {75}, number = {6}, pages = {709-715}, pmid = {29569154}, issn = {1432-0991}, mesh = {Serratia/drug effects/metabolism/*physiology ; Thiadiazines/*pharmacology ; Wolbachia/drug effects/metabolism/*physiology ; }, abstract = {The endosymbionts Wolbachia and Rickettsia have been shown to be correlated with the insecticide resistance of mosquito and whitefly. The small brown planthopper (SBPH), Laodelphax striatellus, harbours many species of endosymbionts, and has developed a high resistance to buprofezin in China. In this study, we examined the species and the infection incidences of endosymbionts in a buprofezin-resistant (BR) strain, a buprofezin-susceptible (BS) strain, and the BR strain after exposure to buprofezin, and we also investigated the change in buprofezin susceptibility after removal of Wolbachia from the BR strain. The results showed that Wolbachia infection incidences were 100% in both the BR and BS strains, but the Wolbachia density in the BR strain was significantly higher than that in the BS strain. There were no significant differences in Arsenophonus infection incidence between the two strains. However, the infection incidence of Serratia and double infection incidence of Serratia + Wolbachia in the BR strain were significantly higher than that in the BS strain. After the BR strain was exposed to 1200 mg/L buprofezin, the infection incidence of Arsenophonus in the surviving individuals increased, and the infection rate of Serratia did not differ, but the double infection incidence of Serratia + Wolbachia decreased. And when a Wolbachia-infected line originating from the BR strain was cleared of Wolbachia, its susceptibility to buprofezin increased. The results suggest that Serratia and Wolbachia infection might improve the buprofezin resistance of SBPH.}, }
@article {pmid29568706, year = {2018}, author = {Kajtoch, &#x141; and Kotásková, N}, title = {Current state of knowledge on Wolbachia infection among Coleoptera: a systematic review.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4471}, pmid = {29568706}, issn = {2167-8359}, abstract = {BACKGROUND: Despite great progress in studies on Wolbachia infection in insects, the knowledge about its relations with beetle species, populations and individuals, and the effects of bacteria on these hosts, is still unsatisfactory. In this review we summarize the current state of knowledge about Wolbachia occurrence and interactions with Coleopteran hosts.<br><br>METHODS: An intensive search of the available literature resulted in the selection of 86 publications that describe the relevant details about Wolbachia presence among beetles. These publications were then examined with respect to the distribution and taxonomy of infected hosts and diversity of Wolbachia found in beetles. Sequences of Wolbachia genes (16S rDNA, ftsZ) were used for the phylogenetic analyses.<br><br>RESULTS: The collected publications revealed that Wolbachia has been confirmed in 204 beetle species and that the estimated average prevalence of this bacteria across beetle species is 38.3% and varies greatly across families and genera (0-88% infected members) and is much lower (c. 13%) in geographic studies. The majority of the examined and infected beetles were from Europe and East Asia. The most intensively studied have been two groups of herbivorous beetles: Curculionidae and Chrysomelidae. Coleoptera harbor Wolbachia belonging to three supergroups: F found in only three species, and A and B found in similar numbers of beetles (including some doubly infected); however the latter two were most prevalent in different families. A total of 59% of species with precise data were found to be totally infected. Single infections were found in 69% of species and others were doubly- or multiply-infected. Wolbachia caused numerous effects on its beetle hosts, including selective sweep with host mtDNA (found in 3% of species), cytoplasmic incompatibility (detected in c. 6% of beetles) and other effects related to reproduction or development (like male-killing, possible parthenogenesis or haplodiploidy induction, and egg development). Phylogenetic reconstructions for Wolbachia genes rejected cospeciation between these bacteria and Coleoptera, with minor exceptions found in some Hydraenidae, Curculionidae and Chrysomelidae. In contrast, horizontal transmission of bacteria has been suspected or proven in numerous cases (e.g., among beetles sharing habitats and/or host plants).<br><br>DISCUSSION: The present knowledge about Wolbachia infection across beetle species and populations is very uneven. Even the basic data about infection status in species and frequency of infected species across genera and families is very superficial, as only c. 0.15% of all beetle species have been tested so far. Future studies on Wolbachia diversity in Coleoptera should still be based on the Multi-locus Sequence Typing system, and next-generation sequencing technologies will be important for uncovering Wolbachia relations with host evolution and ecology, as well as with other, co-occurring endosymbiotic bacteria.}, }
@article {pmid29566306, year = {2018}, author = {Gioia, GV and Vinueza, RL and Marsot, M and Devillers, E and Cruz, M and Petit, E and Boulouis, HJ and Moutailler, S and Monroy, F and Coello, MA and Gondard, M and Bournez, L and Haddad, N and Zanella, G}, title = {Bovine anaplasmosis and tick-borne pathogens in cattle of the Galapagos Islands.}, journal = {Transboundary and emerging diseases}, volume = {65}, number = {5}, pages = {1262-1271}, doi = {10.1111/tbed.12866}, pmid = {29566306}, issn = {1865-1682}, mesh = {Anaplasma marginale/genetics/*isolation &amp; purification ; Anaplasmosis/*epidemiology ; Animals ; Babesia/genetics/isolation &amp; purification ; Cattle ; Cattle Diseases/*epidemiology ; Cross-Sectional Studies ; Ecuador/epidemiology ; Endemic Diseases/*veterinary ; Enzyme-Linked Immunosorbent Assay/veterinary ; Polymerase Chain Reaction/veterinary ; Rhipicephalus/genetics ; Tick-Borne Diseases/*epidemiology/*veterinary ; }, abstract = {A cross-sectional study was conducted to determine the species of Anaplasma spp. and estimate its prevalence in cattle of the three main cattle-producing Galapagos Islands (Santa Cruz, San Cristóbal and Isabela) using indirect PCR assays, genetic sequencing and ELISA. Ticks were also collected from cattle and scanned for 47 tick-borne pathogens in a 48 × 48 real-time PCR chip. A mixed effects logistic regression was performed to identify potential risk factors explaining Anaplasma infection in cattle. A. phagocytophilum was not detected in any of the tested animals. Genetic sequencing allowed detection of A. platys-like strains in 11 (36.7%) of the 30 Anaplasma spp.-positive samples analysed. A. marginale was widespread in the three islands with a global between-herd prevalence of 100% [89; 100]95% CI and a median within-herd prevalence of 93%. A significant association was found between A. marginale infection and age with higher odds of being positive for adults (OR = 3.3 [1.2; 9.9]95% Bootstrap CI). All collected ticks were identified as Rhipicephalus microplus. A. marginale, Babesia bigemina, Borrelia theileri and Francisella-like endosymbiont were detected in tick pools. These results show that the Galapagos Islands are endemic for A. marginale.}, }
@article {pmid29563266, year = {2018}, author = {Vanthournout, B and Busck, MM and Bechsgaard, J and Hendrickx, F and Schramm, A and Bilde, T}, title = {Male spiders control offspring sex ratio through greater production of female-determining sperm.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1875}, pages = {}, pmid = {29563266}, issn = {1471-2954}, support = {282163/ERC_/European Research Council/International ; }, mesh = {Animals ; Cell Nucleus/chemistry ; Chromosomes, Insect/genetics ; Female ; Fluorescent Dyes/chemistry ; Linear Models ; Male ; Microbiota/genetics ; Propidium/chemistry ; RNA, Ribosomal, 16S/genetics ; *Sex Determination Processes ; *Sex Ratio ; Spermatozoa/*metabolism ; Spiders/*genetics/microbiology/*physiology ; }, abstract = {Sex allocation theory predicts that when sons and daughters have different reproductive values, parents should adjust offspring sex ratio towards the sex with the higher fitness return. Haplo-diploid species directly control offspring sex ratio, but species with chromosomal sex determination (CSD) were presumed to be constrained by Mendelian segregation. There is now increasing evidence that CSD species can adjust sex ratio strategically, but the underlying mechanism is not well understood. One hypothesis states that adaptive control is more likely to evolve in the heterogametic sex through a bias in gamete production. We investigated this hypothesis in males as the heterogametic sex in two social spider species that consistently show adaptive female-biased sex ratio and in one subsocial species that is characterized by equal sex ratio. We quantified the production of male (0) and female (X) determining sperm cells using flow cytometry, and show that males of social species produce significantly more X-carrying sperm than 0-sperm, on average 70%. This is consistent with the production of more daughters. Males of the subsocial species produced a significantly lower bias of 54% X-carrying sperm. We also investigated whether inter-genomic conflict between hosts and their endosymbionts may explain female bias. Next generation sequencing showed that five common genera of bacterial endosymbionts known to affect sex ratio are largely absent, ruling out that endosymbiont bacteria bias sex ratio in social spiders. Our study provides evidence for paternal control over sex allocation through biased gamete production as a mechanism by which the heterogametic sex in CSD species adaptively adjust offspring sex ratio.}, }
@article {pmid29561780, year = {2018}, author = {Lindsey, ARI and Bhattacharya, T and Newton, ILG and Hardy, RW}, title = {Conflict in the Intracellular Lives of Endosymbionts and Viruses: A Mechanistic Look at Wolbachia-Mediated Pathogen-blocking.}, journal = {Viruses}, volume = {10}, number = {4}, pages = {}, pmid = {29561780}, issn = {1999-4915}, support = {R21 AI121849/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antibiosis ; Biological Transport ; *Coinfection ; Disease Resistance/genetics/immunology ; Genotype ; *Host-Pathogen Interactions ; Humans ; Insecta/microbiology/virology ; Intracellular Space/microbiology/virology ; Protein Biosynthesis ; RNA Interference ; Rickettsiaceae Infections/*microbiology ; Stress, Physiological ; *Symbiosis ; Virulence ; Virus Assembly ; Virus Diseases/*virology ; Virus Internalization ; *Virus Physiological Phenomena ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {At the forefront of vector control efforts are strategies that leverage host-microbe associations to reduce vectorial capacity. The most promising of these efforts employs Wolbachia, a maternally transmitted endosymbiotic bacterium naturally found in 40% of insects. Wolbachia can spread through a population of insects while simultaneously inhibiting the replication of viruses within its host. Despite successes in using Wolbachia-transfected mosquitoes to limit dengue, Zika, and chikungunya transmission, the mechanisms behind pathogen-blocking have not been fully characterized. Firstly, we discuss how Wolbachia and viruses both require specific host-derived structures, compounds, and processes to initiate and maintain infection. There is significant overlap in these requirements, and infection with either microbe often manifests as cellular stress, which may be a key component of Wolbachia's anti-viral effect. Secondly, we discuss the current understanding of pathogen-blocking through this lens of cellular stress and develop a comprehensive view of how the lives of Wolbachia and viruses are fundamentally in conflict with each other. A thorough understanding of the genetic and cellular determinants of pathogen-blocking will significantly enhance the ability of vector control programs to deploy and maintain effective Wolbachia-mediated control measures.}, }
@article {pmid29559567, year = {2018}, author = {Masson, F and Calderon Copete, S and Schüpfer, F and Garcia-Arraez, G and Lemaitre, B}, title = {In Vitro Culture of the Insect Endosymbiont Spiroplasma poulsonii Highlights Bacterial Genes Involved in Host-Symbiont Interaction.}, journal = {mBio}, volume = {9}, number = {2}, pages = {}, pmid = {29559567}, issn = {2150-7511}, support = {339970/ERC_/European Research Council/International ; }, mesh = {Animals ; Bacterial Proteins/genetics/*metabolism/physiology ; Drosophila/*microbiology ; Spiroplasma/genetics/*metabolism/*physiology ; Symbiosis/genetics/physiology ; }, abstract = {Endosymbiotic bacteria associated with eukaryotic hosts are omnipresent in nature, particularly in insects. Studying the bacterial side of host-symbiont interactions is, however, often limited by the unculturability and genetic intractability of the symbionts. Spiroplasma poulsonii is a maternally transmitted bacterial endosymbiont that is naturally associated with several Drosophila species. S. poulsonii strongly affects its host's physiology, for example by causing male killing or by protecting it against various parasites. Despite intense work on this model since the 1950s, attempts to cultivate endosymbiotic Spiroplasma in vitro have failed so far. Here, we developed a method to sustain the in vitro culture of S. poulsonii by optimizing a commercially accessible medium. We also provide a complete genome assembly, including the first sequence of a natural plasmid of an endosymbiotic Spiroplasma species. Last, by comparing the transcriptome of the in vitro culture to the transcriptome of bacteria extracted from the host, we identified genes putatively involved in host-symbiont interactions. This work provides new opportunities to study the physiology of endosymbiotic Spiroplasma and paves the way to dissect insect-endosymbiont interactions with two genetically tractable partners.IMPORTANCE The discovery of insect bacterial endosymbionts (maternally transmitted bacteria) has revolutionized the study of insects, suggesting novel strategies for their control. Most endosymbionts are strongly dependent on their host to survive, making them uncultivable in artificial systems and genetically intractable. Spiroplasma poulsonii is an endosymbiont of Drosophila that affects host metabolism, reproduction, and defense against parasites. By providing the first reliable culture medium that allows a long-lasting in vitro culture of Spiroplasma and by elucidating its complete genome, this work lays the foundation for the development of genetic engineering tools to dissect endosymbiosis with two partners amenable to molecular study. Furthermore, the optimization method that we describe can be used on other yet uncultivable symbionts, opening new technical opportunities in the field of host-microbes interactions.}, }
@article {pmid29558464, year = {2018}, author = {Souto-Maior, C and Sylvestre, G and Braga Stehling Dias, F and Gomes, MGM and Maciel-de-Freitas, R}, title = {Model-based inference from multiple dose, time course data reveals Wolbachia effects on infection profiles of type 1 dengue virus in Aedes aegypti.}, journal = {PLoS neglected tropical diseases}, volume = {12}, number = {3}, pages = {e0006339}, pmid = {29558464}, issn = {1935-2735}, mesh = {Aedes/*microbiology/*virology ; Animals ; Dengue/prevention &amp; control/transmission ; Dengue Virus/*physiology ; Host-Pathogen Interactions ; *Models, Biological ; Mosquito Vectors/*microbiology/*virology ; Symbiosis ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {Infection is a complex and dynamic process involving a population of invading microbes, the host and its responses, aimed at controlling the situation. Depending on the purpose and level of organization, infection at the organism level can be described by a process as simple as a coin toss, or as complex as a multi-factorial dynamic model; the former, for instance, may be adequate as a component of a population model, while the latter is necessary for a thorough description of the process beginning with a challenge with an infectious inoculum up to establishment or elimination of the pathogen. Experimental readouts in the laboratory are often static, snapshots of the process, assayed under some convenient experimental condition, and therefore cannot comprehensively describe the system. Different from the discrete treatment of infection in population models, or the descriptive summarized accounts of typical lab experiments, in this manuscript, infection is treated as a dynamic process dependent on the initial conditions of the infectious challenge, viral growth, and the host response along time. Here, experimental data is generated for multiple doses of type 1 dengue virus, and pathogen levels are recorded at different points in time for two populations of mosquitoes: either carrying endosymbiont bacteria Wolbachia or not. A dynamic microbe/host-response mathematical model is used to describe pathogen growth in the face of a host response like the immune system, and to infer model parameters for the two populations of insects, revealing a slight-but potentially important-protection conferred by the symbiont.}, }
@article {pmid31294213, year = {2018}, author = {Barros, I and Froufe, H and Marnellos, G and Egas, C and Delaney, J and Clamp, M and Santos, RS and Bettencourt, R}, title = {Metatranscriptomics profile of the gill microbial community during Bathymodiolus azoricus aquarium acclimatization at atmospheric pressure.}, journal = {AIMS microbiology}, volume = {4}, number = {2}, pages = {240-260}, pmid = {31294213}, issn = {2471-1888}, abstract = {BACKGROUND: The deep-sea mussels Bathymodiolus azoricus (Bivalvia: Mytilidae) are the dominant macrofauna subsisting at the hydrothermal vents site Menez Gwen in the Mid-Atlantic Ridge (MAR). Their adaptive success in such challenging environments is largely due to their gill symbiotic association with chemosynthetic bacteria. We examined the response of vent mussels as they adapt to sea-level environmental conditions, through an assessment of the relative abundance of host-symbiont related RNA transcripts to better understand how the gill microbiome may drive host-symbiont interactions in vent mussels during hypothetical venting inactivity.<br><br>RESULTS: The metatranscriptome of B. azoricus was sequenced from gill tissues sampled at different time-points during a five-week acclimatization experiment, using Next-Generation-Sequencing. After Illumina sequencing, a total of 181,985,262 paired-end reads of 150 bp were generated with an average of 16,544,115 read per sample. Metatranscriptome analysis confirmed that experimental acclimatization in aquaria accounted for global gill transcript variation. Additionally, the analysis of 16S and 18S rRNA sequences data allowed for a comprehensive characterization of host-symbiont interactions, which included the gradual loss of gill endosymbionts and signaling pathways, associated with stress responses and energy metabolism, under experimental acclimatization. Dominant active transcripts were assigned to the following KEGG categories: "Ribosome", "Oxidative phosphorylation" and "Chaperones and folding catalysts" suggesting specific metabolic responses to physiological adaptations in aquarium environment.<br><br>CONCLUSIONS: Gill metagenomics analyses highlighted microbial diversity shifts and a clear pattern of varying mRNA transcript abundancies and expression during acclimatization to aquarium conditions which indicate change in bacterial community activity. This approach holds potential for the discovery of new host-symbiont associations, evidencing new functional transcripts and a clearer picture of methane metabolism during loss of endosymbionts. Towards the end of acclimatization, we observed trends in three major functional subsystems, as evidenced by an increment of transcripts related to genetic information processes; the decrease of chaperone and folding catalysts and oxidative phosphorylation transcripts; but no change in transcripts of gluconeogenesis and co-factors-vitamins.}, }
@article {pmid29549429, year = {2018}, author = {Nikas, I and Hapfelmeier, A and Mollenhauer, M and Angermeier, D and Bettstetter, M and Götz, R and Schmidmayr, M and Seifert-Klauss, V and Muckenhuber, A and Schenck, U and Weirich, G}, title = {Integrated morphologic and molecular analysis of Trichomonas vaginalis, Mycoplasma hominis, and human papillomavirus using cytologic smear preparations.}, journal = {Parasitology research}, volume = {117}, number = {5}, pages = {1443-1451}, pmid = {29549429}, issn = {1432-1955}, mesh = {Adolescent ; Adult ; Coinfection ; DNA, Bacterial/analysis ; DNA, Protozoan/analysis ; DNA, Viral/analysis ; Female ; Humans ; Multiplex Polymerase Chain Reaction/methods ; Mycoplasma Infections/*diagnosis/microbiology ; Mycoplasma hominis/*genetics/isolation &amp; purification ; Papanicolaou Test/methods ; Papillomaviridae/*genetics/isolation &amp; purification ; Papillomavirus Infections/*diagnosis/virology ; Trichomonas Vaginitis/*diagnosis/parasitology ; Trichomonas vaginalis/*genetics/isolation &amp; purification ; Uterine Cervical Neoplasms/etiology ; Vaginal Smears/methods ; }, abstract = {Pathogenic microbes may colonize the female genital tract via sexual transmission and cause health issues like inflammation or malignancy, summarized as sexually transmitted disease (STD). A major representative of such pathogens is Trichomonas vaginalis (T.v.), whose role in the etiology of cervical cancer remains elusive. Traditional morphologic screening of cervical smears is able to detect T.v., although its identification may be complicated by look-alikes such as degenerated granulocytes and basal cells. In addition, the parasite's endosymbiont Mycoplasma hominis (M.h.) cannot be detected in the Pap test. This investigation was aimed at designing a PCR-based method to detect specific pathogenic germs by using cervical cytology slides to overcome morphologic uncertainty and increase diagnostic accuracy. To test our molecular screening method on T.v., M.h., and HPV in archival smears, we elaborated a multiplex PCR approach based on microdissection. This assay was applied to a minute quantity of starting material which harbored or was suspected to harbor T.v.; the resulting isolated DNA was used for subsequent molecular analyses of T.v., M.h., and HPV. We clarified the diagnosis of genital T.v. infection in 88 and 1.8% of morphologically suspicious and T.v.-negative cases, respectively. We also revealed a tendency of M.h. co-infection in high-risk HPV cases. In conclusion, a microdissection-based approach to detect pathogenic microbes such as T.v., HPV, and M.h. is a molecular tool easy to implement and may help to better understand the interactivity of these germs with respect to pathogenesis.}, }
@article {pmid29540638, year = {2018}, author = {Sharmin, D and Guo, Y and Nishizawa, T and Ohshima, S and Sato, Y and Takashima, Y and Narisawa, K and Ohta, H}, title = {Comparative Genomic Insights into Endofungal Lifestyles of Two Bacterial Endosymbionts, Mycoavidus cysteinexigens and Burkholderia rhizoxinica.}, journal = {Microbes and environments}, volume = {33}, number = {1}, pages = {66-76}, pmid = {29540638}, issn = {1347-4405}, mesh = {Burkholderia/*genetics/physiology ; Burkholderiaceae/*genetics/physiology ; Comparative Genomic Hybridization ; Fungi/*physiology ; Genome, Bacterial ; Metagenome ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Endohyphal bacteria (EHB), dwelling within fungal hyphae, markedly affect the growth and metabolic potential of their hosts. To date, two EHB belonging to the family Burkholderiaceae have been isolated and characterized as new taxa, Burkholderia rhizoxinica (HKI 454[T]) and Mycoavidus cysteinexigens (B1-EB[T]), in Japan. Metagenome sequencing was recently reported for Mortierella elongata AG77 together with its endosymbiont M. cysteinexigens (Mc-AG77) from a soil/litter sample in the USA. In the present study, we elucidated the complete genome sequence of B1-EB[T] and compared it with those of Mc-AG77 and HKI 454[T]. The genomes of B1-EB[T] and Mc-AG77 contained a higher level of prophage sequences and were markedly smaller than that of HKI 454[T]. Although the B1-EB[T] and Mc-AG77 genomes lacked the chitinolytic enzyme genes responsible for invasion into fungal cells, they contained several predicted toxin-antitoxin systems including an insecticidal toxin complex and PIN domain imposing an addiction-like mechanism essential for endohyphal growth control during host colonization. Despite the different host fungi, the alignment of amino acid sequences showed that the HKI 454[T] genome consisted of 1,265 (32.6%) and 1,221 (31.5%) orthologous coding sequences (CDSs) with those of B1-EB[T] and Mc-AG77, respectively. This comparative study of three phylogenetically associated endosymbionts has provided insights into their origin and evolution, and suggests the later bacterial invasion and adaptation of B1-EB[T] to its host metabolism.}, }
@article {pmid29530790, year = {2018}, author = {Zhang, X and Tang, S and Liu, Q and Cheke, RA and Zhu, H}, title = {Models to assess the effects of non-identical sex ratio augmentations of Wolbachia-carrying mosquitoes on the control of dengue disease.}, journal = {Mathematical biosciences}, volume = {299}, number = {}, pages = {58-72}, doi = {10.1016/j.mbs.2018.03.003}, pmid = {29530790}, issn = {1879-3134}, support = {//CIHR/Canada ; }, mesh = {Aedes/*microbiology ; Animals ; Dengue/*prevention &amp; control ; Female ; Male ; *Models, Theoretical ; Mosquito Vectors/*microbiology ; Pest Control, Biological/*methods ; *Sex Ratio ; Wolbachia/*pathogenicity ; }, abstract = {The introduction of endosymbiont Wolbachia into laboratory-reared mosquito populations, which are then released to mix with natural populations to prevent the mosquito vectors from reproducing and thus break the transmission cycle of dengue disease, is an innovative new technology. Field trials of Wolbachia-carrying mosquitoes have now been implemented in many countries where there have been the outbreaks of dengue disease. A mathematical model is proposed to investigate the effects of non-identical sex ratio releases of Wolbachia-carrying mosquitoes on the control of dengue transmission. Firstly, we analyzed the existence and stability of equilibria for the system and proved the existence of forward and backward bifurcations. Secondly, bifurcation diagrams, the basins of attraction of the equilibria and the effects of mosquito augmentation for the system with imperfect and perfect transmission rates were obtained. Thirdly, three possible results for mosquito augmentation were summarized for different parameter regions. Further we explored an uncertainty and sensitivity analysis of solutions to estimate the effects of different parameter values on the success or failure of population replacement. Based on the above analysis, we considered a series of relevant issues such as (a) whether or not mosquito augmentation can ensure the success of population replacement? (b) If not, what are the parameter regions for the success or possible success of population replacement? (c) How does the initial density of natural mosquitoes and the quantity of mosquito augmentations affect the success of population replacement? (d) Whether all population replacements are effective for reducing the spread of dengue virus in the end? The results of this study will be helpful for public health authorities in designing proper strategies of mosquito augmentations for the control of dengue disease.}, }
@article {pmid29530467, year = {2018}, author = {Varela-Stokes, AS and Park, SH and Stokes, JV and Gavron, NA and Lee, SI and Moraru, GM and Ricke, SC}, title = {Tick microbial communities within enriched extracts of Amblyomma maculatum.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {4}, pages = {798-805}, pmid = {29530467}, issn = {1877-9603}, support = {P20 GM103646/GM/NIGMS NIH HHS/United States ; T35 OD010432/OD/NIH HHS/United States ; }, mesh = {Actinobacteria/genetics/isolation &amp; purification ; Animals ; DNA, Bacterial/genetics/isolation &amp; purification ; Francisella/genetics/isolation &amp; purification ; High-Throughput Nucleotide Sequencing ; Ixodidae/*microbiology ; Microbiota/*genetics ; Mississippi/epidemiology ; Phylogeny ; Proteobacteria/genetics/isolation &amp; purification ; Rickettsia/genetics ; Tick Infestations/epidemiology ; Tissue Extracts ; }, abstract = {Our objective of this study was to explore the bacterial microbiome in fresh or fresh-frozen adult Amblyomma maculatum (Gulf Coast ticks) using extracts enriched for microbial DNA. We collected 100 questing adult A. maculatum, surface disinfected them, and extracted DNA from individual ticks collected the same day or after storage at -80 °C. Because only extracts with microbial DNA concentrations above 2 ng/μL were considered suitable for individual analysis, we expected fewer samples to meet these requirements. Of individual ticks extracted, 48 extracts met this minimum concentration. We pooled 20 additional extracts that had lower concentrations to obtain seven additional pools that met the minimum DNA concentration. Libraries created from these 55 samples were sequenced using an Illumina MiSeq platform, and data sets were analyzed using QIIME to identify relative abundance of microorganisms by phylum down to genus levels. Proteobacteria were in greatest abundance, followed by Actinobacteria, Firmicutes, and Bacteroidetes, at levels between 1.9% and 6.4% average relative abundance. Consistent with the Francisella-like endosymbiont known to be present in A. maculatum, the genus Francisella was detected at highest relative abundance (72.9%; SE 0.02%) for all samples. Among the top ten genera identified (relative abundance ≥ 0.5%) were potential extraction kit contaminants, Sphingomonas and Methylobacterium, the soil bacterium Actinomycetospora, and the known A. maculatum-associated genus, Rickettsia. Four samples had Rickettsia at greater than 1% relative abundance, while nine additional samples had Rickettsia at low (0.01-0.04%) relative abundance. In this study, we used the entire microbe-enriched DNA extract for whole ticks for microbiome analysis. A direct comparison of the microbiome in microbe-enriched DNA and total genomic DNA extracts from halves of the same tick would be useful to determine the utility of this extraction method in this system. We anticipate that future tick microbiome studies will be valuable to explore the influence of microbial diversity on pathogen maintenance and transmission, and to evaluate niche-specific microbiomes within individual tick tissues.}, }
@article {pmid29526588, year = {2018}, author = {Turelli, M and Cooper, BS and Richardson, KM and Ginsberg, PS and Peckenpaugh, B and Antelope, CX and Kim, KJ and May, MR and Abrieux, A and Wilson, DA and Bronski, MJ and Moore, BR and Gao, JJ and Eisen, MB and Chiu, JC and Conner, WR and Hoffmann, AA}, title = {Rapid Global Spread of wRi-like Wolbachia across Multiple Drosophila.}, journal = {Current biology : CB}, volume = {28}, number = {6}, pages = {963-971.e8}, pmid = {29526588}, issn = {1879-0445}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; R35 GM124701/GM/NIGMS NIH HHS/United States ; S10 RR027303/RR/NCRR NIH HHS/United States ; S10 RR029668/RR/NCRR NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Biological Evolution ; DNA, Mitochondrial/analysis/genetics ; Disease Transmission, Infectious/veterinary ; Drosophila/*genetics/microbiology ; Evolution, Molecular ; Genome/genetics ; Infectious Disease Transmission, Vertical/veterinary ; Introduced Species ; Phylogeny ; Symbiosis/genetics ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Maternally transmitted Wolbachia, Spiroplasma, and Cardinium bacteria are common in insects [1], but their interspecific spread is poorly understood. Endosymbionts can spread rapidly within host species by manipulating host reproduction, as typified by the global spread of wRi Wolbachia observed in Drosophila simulans [2, 3]. However, because Wolbachia cannot survive outside host cells, spread between distantly related host species requires horizontal transfers that are presumably rare [4-7]. Here, we document spread of wRi-like Wolbachia among eight highly diverged Drosophila hosts (10-50 million years) over only about 14,000 years (5,000-27,000). Comparing 110 wRi-like genomes, we find ≤0.02% divergence from the wRi variant that spread rapidly through California populations of D. simulans. The hosts include both globally invasive species (D. simulans, D. suzukii, and D. ananassae) and narrowly distributed Australian endemics (D. anomalata and D. pandora) [8]. Phylogenetic analyses that include mtDNA genomes indicate introgressive transfer of wRi-like Wolbachia between closely related species D. ananassae, D. anomalata, and D. pandora but no horizontal transmission within species. Our analyses suggest D. ananassae as the Wolbachia source for the recent wRi invasion of D. simulans and D. suzukii as the source of Wolbachia in its sister species D. subpulchrella. Although six of these wRi-like variants cause strong cytoplasmic incompatibility, two cause no detectable reproductive effects, indicating that pervasive mutualistic effects [9, 10] complement the reproductive manipulations for which Wolbachia are best known. "Super spreader" variants like wRi may be particularly useful for controlling insect pests and vector-borne diseases with Wolbachia transinfections [11].}, }
@article {pmid29520067, year = {2018}, author = {Woodford, L and Bianco, G and Ivanova, Y and Dale, M and Elmer, K and Rae, F and Larcombe, SD and Helm, B and Ferguson, HM and Baldini, F}, title = {Vector species-specific association between natural Wolbachia infections and avian malaria in black fly populations.}, journal = {Scientific reports}, volume = {8}, number = {1}, pages = {4188}, pmid = {29520067}, issn = {2045-2322}, mesh = {Animals ; Birds ; Haemosporida/*physiology ; *Insect Vectors/microbiology/parasitology ; *Malaria, Avian/epidemiology/microbiology/parasitology/transmission ; *Rickettsiaceae Infections/epidemiology/parasitology/transmission ; *Simuliidae/microbiology/parasitology ; Species Specificity ; Wolbachia/*physiology ; }, abstract = {Artificial infection of mosquitoes with the endosymbiont bacteria Wolbachia can interfere with malaria parasite development. Therefore, the release of Wolbachia-infected mosquitoes has been proposed as a malaria control strategy. However, Wolbachia effects on vector competence are only partly understood, as indicated by inconsistent effects on malaria infection reported under laboratory conditions. Studies of naturally-occurring Wolbachia infections in wild vector populations could be useful to identify the ecological and evolutionary conditions under which these endosymbionts can block malaria transmission. Here we demonstrate the occurrence of natural Wolbachia infections in three species of black fly (genus Simulium), which is a main vector of the avian malaria parasite Leucocytozoon. Prevalence of Leucocytozoon was high (25%), but the nature and magnitude of its association with Wolbachia differed between black fly species. Wolbachia infection was positively associated with avian malaria infection in S. cryophilum, negatively associated in S. aureum, and unrelated in S. vernum. These differences suggest that Wolbachia interacts with the parasite in a vector host species-specific manner. This provides a useful model system for further study of how Wolbachia influences vector competence. Such knowledge, including the possibility of undesirable positive association, is required to guide endosymbiont based control methods.}, }
@article {pmid29515525, year = {2018}, author = {Lewis, WH and Sendra, KM and Embley, TM and Esteban, GF}, title = {Morphology and Phylogeny of a New Species of Anaerobic Ciliate, Trimyema finlayi n. sp., with Endosymbiotic Methanogens.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {140}, pmid = {29515525}, issn = {1664-302X}, support = {268701/ERC_/European Research Council/International ; }, abstract = {Many anaerobic ciliated protozoa contain organelles of mitochondrial ancestry called hydrogenosomes. These organelles generate molecular hydrogen that is consumed by methanogenic Archaea, living in endosymbiosis within many of these ciliates. Here we describe a new species of anaerobic ciliate, Trimyema finlayi n. sp., by using silver impregnation and microscopy to conduct a detailed morphometric analysis. Comparisons with previously published morphological data for this species, as well as the closely related species, Trimyema compressum, demonstrated that despite them being similar, both the mean cell size and the mean number of somatic kineties are lower for T. finlayi than for T. compressum, which suggests that they are distinct species. This was also supported by analysis of the 18S rRNA genes from these ciliates, the sequences of which are 97.5% identical (6 substitutions, 1479 compared bases), and in phylogenetic analyses these sequences grouped with other 18S rRNA genes sequenced from previous isolates of the same respective species. Together these data provide strong evidence that T. finlayi is a novel species of Trimyema, within the class Plagiopylea. Various microscopic techniques demonstrated that T. finlayi n. sp. contains polymorphic endosymbiotic methanogens, and analysis of the endosymbionts' 16S rRNA gene showed that they belong to the genus Methanocorpusculum, which was confirmed using fluorescence in situ hybridization with specific probes. Despite the degree of similarity and close relationship between these ciliates, T. compressum contains endosymbiotic methanogens from a different genus, Methanobrevibacter. In phylogenetic analyses of 16S rRNA genes, the Methanocorpusculum endosymbiont of T. finlayi n. sp. grouped with sequences from Methanomicrobia, including the endosymbiont of an earlier isolate of the same species, 'Trimyema sp.,' which was sampled approximately 22 years earlier, at a distant (∼400 km) geographical location. Identification of the same endosymbiont species in the two separate isolates of T. finlayi n. sp. provides evidence for spatial and temporal stability of the Methanocorpusculum-T. finlayi n. sp. endosymbiosis. T. finlayi n. sp. and T. compressum provide an example of two closely related anaerobic ciliates that have endosymbionts from different methanogen genera, suggesting that the endosymbionts have not co-speciated with their hosts.}, }
@article {pmid29515524, year = {2018}, author = {Pillonel, T and Bertelli, C and Greub, G}, title = {Environmental Metagenomic Assemblies Reveal Seven New Highly Divergent Chlamydial Lineages and Hallmarks of a Conserved Intracellular Lifestyle.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {79}, pmid = {29515524}, issn = {1664-302X}, abstract = {The Chlamydiae phylum exclusively encompasses bacteria sharing a similar obligate intracellular life cycle. Existing 16S rDNA data support a high diversity within the phylum, however genomic data remain scarce owing to the difficulty in isolating strains using culture systems with eukaryotic cells. Yet, Chlamydiae genome data extracted from large scale metagenomic studies might help fill this gap. This work compares 33 cultured and 27 environmental, uncultured chlamydial genomes, in order to clarify the phylogenetic relatedness of the new chlamydial clades and to investigate the genetic diversity of the Chlamydiae phylum. The analysis of published chlamydial genomes from metagenomics bins and single cell sequencing allowed the identification of seven new deeply branching chlamydial clades sharing genetic hallmarks of parasitic Chlamydiae. Comparative genomics suggests important biological differences between those clades, including loss of many proteins involved in cell division in the genus Similichlamydia, and loss of respiratory chain and tricarboxylic acid cycle in several species. Comparative analyses of chlamydial genomes with two proteobacterial orders, the Rhizobiales and the Rickettsiales showed that genomes of different Rhizobiales families are much more similar than genomes of different Rickettsiales families. On the other hand, the chlamydial 16S rRNAs exhibit a higher sequence conservation than their Rickettsiales counterparts, while chlamydial proteins exhibit increased sequence divergence. Studying the diversity and genome plasticity of the entire Chlamydiae phylum is of major interest to better understand the emergence and evolution of this ubiquitous and ancient clade of obligate intracellular bacteria.}, }
@article {pmid29608200, year = {2017}, author = {Sseruwagi, P and Wainaina, J and Ndunguru, J and Tumuhimbise, R and Tairo, F and Guo, JY and Vrielink, A and Blythe, A and Kinene, T and De Marchi, B and Kehoe, MA and Tanz, S and Boykin, LM}, title = {The first transcriptomes from field-collected individual whiteflies (Bemisia tabaci, Hemiptera: Aleyrodidae): a case study of the endosymbiont composition.}, journal = {Gates open research}, volume = {1}, number = {}, pages = {16}, pmid = {29608200}, issn = {2572-4754}, abstract = {Background: Bemisia tabaci species (B. tabaci), or whiteflies, are the world's most devastating insect pests. They cause billions of dollars (US) of damage each year, and are leaving farmers in the developing world food insecure. Currently, all publically available transcriptome data for B. tabaci are generated from pooled samples, which can lead to high heterozygosity and skewed representation of the genetic diversity. The ability to extract enough RNA from a single whitefly has remained elusive due to their small size and technological limitations. Methods: In this study, we optimised a single whitefly RNA extraction procedure, and sequenced the transcriptome of four individual adult Sub-Saharan Africa 1 (SSA1) B. tabaci. Transcriptome sequencing resulted in 39-42 million raw reads. De novo assembly of trimmed reads yielded between 65,000-162,000 Contigs across B. tabaci transcriptomes. Results: Bayesian phylogenetic analysis of mitochondrion cytochrome I oxidase (mtCOI) grouped the four whiteflies within the SSA1 clade. BLASTn searches on the four transcriptomes identified five endosymbionts; the primary endosymbiont Portiera aleyrodidarum and four secondary endosymbionts: Arsenophonus, Wolbachia, Rickettsia, and Cardinium spp. that were predominant across all four SSA1 B. tabaci samples with prevalence levels of between 54.1 to 75%. Amino acid alignments of the NusG gene of P. aleyrodidarum for the SSA1 B. tabaci transcriptomes of samples WF2 and WF2b revealed an eleven amino acid residue deletion that was absent in samples WF1 and WF2a. Comparison of the protein structure of the NusG protein from P. aleyrodidarum in SSA1 with known NusG structures showed the deletion resulted in a shorter D loop. Conclusions: The use of field-collected specimens means time and money will be saved in future studies using single whitefly transcriptomes in monitoring vector and viral interactions. Our method is applicable to any small organism where RNA quantity has limited transcriptome studies.}, }
@article {pmid29511084, year = {2018}, author = {Tashyreva, D and Prokopchuk, G and Votýpka, J and Yabuki, A and Horák, A and Lukeš, J}, title = {Life Cycle, Ultrastructure, and Phylogeny of New Diplonemids and Their Endosymbiotic Bacteria.}, journal = {mBio}, volume = {9}, number = {2}, pages = {}, pmid = {29511084}, issn = {2150-7511}, mesh = {Bacteria/genetics ; Life Cycle Stages/physiology ; Meiotic Prophase I/*physiology ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; Symbiosis/*physiology ; }, abstract = {Diplonemids represent a hyperdiverse and abundant yet poorly studied group of marine protists. Here we describe two new members of the genus Diplonema (Diplonemea, Euglenozoa), Diplonema japonicum sp. nov. and Diplonema aggregatum sp. nov., based on life cycle, morphology, and 18S rRNA gene sequences. Along with euglenozoan apomorphies, they contain several unique features. Their life cycle is complex, consisting of a trophic stage that is, following the depletion of nutrients, transformed into a sessile stage and subsequently into a swimming stage. The latter two stages are characterized by the presence of tubular extrusomes and the emergence of a paraflagellar rod, the supportive structure of the flagellum, which is prominently lacking in the trophic stage. These two stages also differ dramatically in motility and flagellar size. Both diplonemid species host endosymbiotic bacteria that are closely related to each other and constitute a novel branch within Holosporales, for which a new genus, "Candidatus Cytomitobacter" gen. nov., has been established. Remarkably, the number of endosymbionts in the cytoplasm varies significantly, as does their localization within the cell, where they seem to penetrate the mitochondrion, a rare occurrence.IMPORTANCE We describe the morphology, behavior, and life cycle of two new Diplonema species that established a relationship with two Holospora-like bacteria in the first report of an endosymbiosis in diplonemids. Both endosymbionts reside in the cytoplasm and the mitochondrion, which establishes an extremely rare case. Within their life cycle, the diplonemids undergo transformation from a trophic to a sessile and eventually a highly motile swimming stage. These stages differ in several features, such as the presence or absence of tubular extrusomes and a paraflagellar rod, along with the length of the flagella. These morphological and behavioral interstage differences possibly reflect distinct functions in dispersion and invasion of the host and/or prey and may provide novel insight into the virtually unknown function of diplonemids in the oceanic ecosystem.}, }
@article {pmid29507840, year = {2018}, author = {Brüwer, JD and Voolstra, CR}, title = {First insight into the viral community of the cnidarian model metaorganism Aiptasia using RNA-Seq data.}, journal = {PeerJ}, volume = {6}, number = {}, pages = {e4449}, pmid = {29507840}, issn = {2167-8359}, abstract = {Current research posits that all multicellular organisms live in symbioses with associated microorganisms and form so-called metaorganisms or holobionts. Cnidarian metaorganisms are of specific interest given that stony corals provide the foundation of the globally threatened coral reef ecosystems. To gain first insight into viruses associated with the coral model system Aiptasia (sensu Exaiptasia pallida), we analyzed an existing RNA-Seq dataset of aposymbiotic, partially populated, and fully symbiotic Aiptasia CC7 anemones with Symbiodinium. Our approach included the selective removal of anemone host and algal endosymbiont sequences and subsequent microbial sequence annotation. Of a total of 297 million raw sequence reads, 8.6 million (∼3%) remained after host and endosymbiont sequence removal. Of these, 3,293 sequences could be assigned as of viral origin. Taxonomic annotation of these sequences suggests that Aiptasia is associated with a diverse viral community, comprising 116 viral taxa covering 40 families. The viral assemblage was dominated by viruses from the families Herpesviridae (12.00%), Partitiviridae (9.93%), and Picornaviridae (9.87%). Despite an overall stable viral assemblage, we found that some viral taxa exhibited significant changes in their relative abundance when Aiptasia engaged in a symbiotic relationship with Symbiodinium. Elucidation of viral taxa consistently present across all conditions revealed a core virome of 15 viral taxa from 11 viral families, encompassing many viruses previously reported as members of coral viromes. Despite the non-random selection of viral genetic material due to the nature of the sequencing data analyzed, our study provides a first insight into the viral community associated with Aiptasia. Similarities of the Aiptasia viral community with those of corals corroborate the application of Aiptasia as a model system to study coral holobionts. Further, the change in abundance of certain viral taxa across different symbiotic states suggests a role of viruses in the algal endosymbiosis, but the functional significance of this remains to be determined.}, }
@article {pmid29506121, year = {2018}, author = {Zouari, S and Ben Halima, MK and Reyes-Prieto, M and Latorre, A and Gil, R}, title = {Natural Occurrence of Secondary Bacterial Symbionts in Aphids from Tunisia, with a Focus on Genus Hyalopterus.}, journal = {Environmental entomology}, volume = {47}, number = {2}, pages = {325-333}, doi = {10.1093/ee/nvy005}, pmid = {29506121}, issn = {1938-2936}, mesh = {Animals ; Aphids/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; *Symbiosis ; Tunisia ; }, abstract = {Aphids (Hemiptera: Aphididae) can harbor two types of bacterial symbionts. In addition to the obligate endosymbiont Buchnera aphidicola Munson, Baumann and Kinsey 1991 (Enterobacteriales: Enterobacteriaceae), several facultative symbiotic bacteria, called secondary (S) symbionts, have been identified among many important pest aphid species. To determine interpopulational diversity of S-symbionts, we carried out a survey in a total of 18 populations of six aphid species collected from six localities in Tunisia, by performing a diagnostic polymerase chain reaction analysis of partial 16S-23S rRNA operon sequences. While 61.7% of individuals contained only Buchnera, three S-symbionts were found at different frequencies. Arsenophonus sp. Gherna et al. 1991 (Enterobacteriales: Enterobacteriaceae) was found in all species under study except for Acyrtosiphon pisum (Harris 1776) (Aphidinae: Macrosiphini); Serratia symbiotica Moran et al. 2005 (Enterobacteriales: Enterobacteriaceae) was present in all analyzed individuals of A. pisum but only sporadically in Aphis spiraecola (Patch 1914) (Aphidinae: Aphidini) and Hyalopterus amygdali (Blanchard 1840) (Aphidinae: Aphidini), while Hamiltonella defensa Moran et al. 2005 (Enterobacteriales: Enterobacteriaceae) was found in all analyzed individuals of one population of Aphis gossypii (Glover 1877) (Aphidinae: Aphidini) and sporadically in two populations of Hyalopterus. The lysogenic bacteriophage APSE-1 (A. pisum secondary endosymbiont, type 1) was detected in the three populations infected with H. defensa. This bacteriophage has been associated with moderate protection against braconid parasitoids in pea aphids. The high prevalence of Arsenophonus sp. in our samples is in accordance with previous studies indicating that, among gammaproteobacteria, this genus is one of the most widespread insect facultative symbionts.}, }
@article {pmid29499213, year = {2018}, author = {Bi, J and Sehgal, A and Williams, JA and Wang, YF}, title = {Wolbachia affects sleep behavior in Drosophila melanogaster.}, journal = {Journal of insect physiology}, volume = {107}, number = {}, pages = {81-88}, doi = {10.1016/j.jinsphys.2018.02.011}, pmid = {29499213}, issn = {1879-1611}, mesh = {Animals ; Arousal ; Circadian Rhythm ; Drosophila melanogaster/*microbiology/*physiology ; Female ; Insect Proteins ; Male ; *Sleep ; Symbiosis ; Up-Regulation ; Wolbachia/*physiology ; }, abstract = {Wolbachia are endosymbiotic bacteria present in a wide range of insects. Although their dramatic effects on host reproductive biology have been well studied, the effects of Wolbachia on sleep behavior of insect hosts are not well documented. In this study, we report that Wolbachia infection caused an increase of total sleep time in both male and female Drosophila melanogaster. The increase in sleep was associated with an increase in the number of nighttime sleep bouts or episodes, but not in sleep bout duration. Correspondingly, Wolbachia infection also reduced the arousal threshold of their fly hosts. However, neither circadian rhythm nor sleep rebound following deprivation was influenced by Wolbachia infection. Transcriptional analysis of the dopamine biosynthesis pathway revealed that two essential genes, Pale and Ddc, were significantly upregulated in Wolbachia-infected flies. Together, these results indicate that Wolbachia mediates the expression of dopamine related genes, and decreases the sleep quality of their insect hosts. Our findings help better understand the host-endosymbiont interactions and in particular the Wolbachia's impact on behaviors, and thus on ecology and evolution in insect hosts.}, }
@article {pmid29497475, year = {2018}, author = {Hashmi, TR and Devi, SR and Meshram, NM and Prasad, R}, title = {Assessment of bacterial endosymbionts and the host, Bemisia tabaci (Hemiptera: Aleyrodidae), using rRNA and mitochondrial cytochrome oxidase I gene sequences.}, journal = {Communicative &amp; integrative biology}, volume = {11}, number = {1}, pages = {e1433442}, pmid = {29497475}, issn = {1942-0889}, abstract = {Endosymbionts are vital factor for arthropod ecology. The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a cryptic species complex composed of more than 34 putative species. Moreover to the primary endosymbiont Portiera aleyrodidarum, six secondary endosymbionts Cardinium, Arsenophonus, Rickettsia, Wolbachia, Hamiltonella and Fritschea are known in B. tabaci. Here, we tested four of the six secondary endosymbiont lineages (excluding Fritschea and Hamiltonella) from 180 whitely individuals collected from six host plants belonging to families Solanaceae (Brinjal, Tomato and Potato) and Fabaceae (Soyabean, Mungbean and Subabool). Phylogenetic studies grounded on the mitochondrial cytochrome I gene revealed the presence of Asia 1, Asia II 1 and Asia II 7 genetic groups for B. tabaci. Specific primers targeting 16S rRNA and 23S rRNA gene were used for estimating the bacterial endosymbionts. As a primary endosymbiont Portiera aleyrodidarum was present in all the studied samples; whereas, an uneven distribution of secondary endosymbionts were recorded. Overall our finding exposes the variation and diversity of endosymbionts within the B. tabaci collected from different host plants and outlines the genetic groups of the insect pest. The study delivers a significant information concerning the circulation of secondary endosymbionts with host preferences of B. tabaci and provides suggestion for progressive studies on targeting the specific endosymbionts with respect to host for the control measures.}, }
@article {pmid29494599, year = {2018}, author = {Kumlert, R and Chaisiri, K and Anantatat, T and Stekolnikov, AA and Morand, S and Prasartvit, A and Makepeace, BL and Sungvornyothin, S and Paris, DH}, title = {Autofluorescence microscopy for paired-matched morphological and molecular identification of individual chigger mites (Acari: Trombiculidae), the vectors of scrub typhus.}, journal = {PloS one}, volume = {13}, number = {3}, pages = {e0193163}, pmid = {29494599}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; DNA/genetics ; Genotype ; Microscopy, Fluorescence/*methods ; Optical Imaging/*methods ; *Phylogeny ; Trombiculidae/anatomy &amp; histology/classification/*genetics/*ultrastructure ; }, abstract = {BACKGROUND: Conventional gold standard characterization of chigger mites involves chemical preparation procedures (i.e. specimen clearing) for visualization of morphological features, which however contributes to destruction of the arthropod host DNA and any endosymbiont or pathogen DNA harbored within the specimen.<br><br>In this study, a novel work flow based on autofluorescence microscopy was developed to enable identification of trombiculid mites to the species level on the basis of morphological traits without any special preparation, while preserving the mite DNA for subsequent genotyping. A panel of 16 specifically selected fluorescence microscopy images of mite features from available identification keys served for complete chigger morphological identification to the species level, and was paired with corresponding genotype data. We evaluated and validated this method for paired chigger morphological and genotypic ID using the mitochondrial cytochrome c oxidase subunit I gene (coi) in 113 chigger specimens representing 12 species and 7 genera (Leptotrombidium, Ascoschoengastia, Gahrliepia, Walchia, Blankaartia, Schoengastia and Schoutedenichia) from the Lao People's Democratic Republic (Lao PDR) to the species level (complete characterization), and 153 chiggers from 5 genera (Leptotrombidium, Ascoschoengastia, Helenicula, Schoengastiella and Walchia) from Thailand, Cambodia and Lao PDR to the genus level. A phylogenetic tree constructed from 77 coi gene sequences (approximately 640 bp length, n = 52 new coi sequences and n = 25 downloaded from GenBank), demonstrated clear grouping of assigned morphotypes at the genus levels, although evidence of both genetic polymorphism and morphological plasticity was found.<br><br>CONCLUSIONS/SIGNIFICANCE: With this new methodology, we provided the largest collection of characterized coi gene sequences for trombiculid mites to date, and almost doubled the number of available characterized coi gene sequences with a single study. The ability to provide paired phenotypic-genotypic data is of central importance for future characterization of mites and dissecting the molecular epidemiology of mites transmitting diseases like scrub typhus.}, }
@article {pmid29492770, year = {2018}, author = {Hornok, S and Szőke, K and Estók, P and Krawczyk, A and Haarsma, AJ and Kováts, D and Boldogh, SA and Morandini, P and Szekeres, S and Takács, N and Kontschán, J and Meli, ML and Fernández de Mera, IG and de la Fuente, J and Gyuranecz, M and Sulyok, KM and Weibel, B and Gönczi, E and de Bruin, A and Sprong, H and Hofmann-Lehmann, R}, title = {Assessing bat droppings and predatory bird pellets for vector-borne bacteria: molecular evidence of bat-associated Neorickettsia sp. in Europe.}, journal = {Antonie van Leeuwenhoek}, volume = {111}, number = {9}, pages = {1707-1717}, doi = {10.1007/s10482-018-1043-7}, pmid = {29492770}, issn = {1572-9699}, mesh = {Anaplasma phagocytophilum/genetics ; Anaplasmataceae Infections/microbiology ; Animals ; Birds/*microbiology ; Chiroptera/*microbiology ; DNA, Bacterial/genetics ; Europe ; Feces/*microbiology ; Neorickettsia/classification/*genetics/isolation &amp; purification ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Strigiformes ; }, abstract = {In Europe, several species of bats, owls and kestrels exemplify highly urbanised, flying vertebrates, which may get close to humans or domestic animals. Bat droppings and bird pellets may have epidemiological, as well as diagnostic significance from the point of view of pathogens. In this work 221 bat faecal and 118 bird pellet samples were screened for a broad range of vector-borne bacteria using PCR-based methods. Rickettsia DNA was detected in 13 bat faecal DNA extracts, including the sequence of a rickettsial insect endosymbiont, a novel Rickettsia genotype and Rickettsia helvetica. Faecal samples of the pond bat (Myotis dasycneme) were positive for a Neorickettsia sp. and for haemoplasmas of the haemofelis group. In addition, two bird pellets (collected from a Long-eared Owl, Asio otus, and from a Common Kestrel, Falco tinnunculus) contained the DNA of a Rickettsia sp. and Anaplasma phagocytophilum, respectively. In both of these bird pellets the bones of Microtus arvalis were identified. All samples were negative for Borrelia burgdorferi s.l., Francisella tularensis, Coxiella burnetii and Chlamydiales. In conclusion, bats were shown to pass rickettsia and haemoplasma DNA in their faeces. Molecular evidence is provided for the presence of Neorickettsia sp. in bat faeces in Europe. In the evaluated regions bat faeces and owl/kestrel pellets do not appear to pose epidemiological risk from the point of view of F. tularensis, C. burnetii and Chlamydiales. Testing of bird pellets may provide an alternative approach to trapping for assessing the local occurrence of vector-borne bacteria in small mammals.}, }
@article {pmid29489396, year = {2018}, author = {Nowack, ECM and Weber, APM}, title = {Genomics-Informed Insights into Endosymbiotic Organelle Evolution in Photosynthetic Eukaryotes.}, journal = {Annual review of plant biology}, volume = {69}, number = {}, pages = {51-84}, doi = {10.1146/annurev-arplant-042817-040209}, pmid = {29489396}, issn = {1545-2123}, mesh = {*Biological Evolution ; Eukaryota/*genetics ; *Genomics ; Organelles/*metabolism ; *Photosynthesis ; Symbiosis/*genetics ; }, abstract = {The conversion of free-living cyanobacteria to photosynthetic organelles of eukaryotic cells through endosymbiosis transformed the biosphere and eventually provided the basis for life on land. Despite the presumable advantage conferred by the acquisition of photoautotrophy through endosymbiosis, only two independent cases of primary endosymbiosis have been documented: one that gave rise to the Archaeplastida, and the other to photosynthetic species of the thecate, filose amoeba Paulinella. Here, we review recent genomics-informed insights into the primary endosymbiotic origins of cyanobacteria-derived organelles. Furthermore, we discuss the preconditions for the evolution of nitrogen-fixing organelles. Recent genomic data on previously undersampled cyanobacterial and protist taxa provide new clues to the origins of the host cell and endosymbiont, and proteomic approaches allow insights into the rearrangement of the endosymbiont proteome during organellogenesis. We conclude that in addition to endosymbiotic gene transfers, horizontal gene acquisitions from a broad variety of prokaryotic taxa were crucial to organelle evolution.}, }
@article {pmid29478272, year = {2018}, author = {Kamikawa, R and Yazaki, E and Tahara, M and Sakura, T and Matsuo, E and Nagamune, K and Hashimoto, T and Inagaki, Y}, title = {Fates of Evolutionarily Distinct, Plastid-type Glyceraldehyde 3-phosphate Dehydrogenase Genes in Kareniacean Dinoflagellates.}, journal = {The Journal of eukaryotic microbiology}, volume = {65}, number = {5}, pages = {669-678}, doi = {10.1111/jeu.12512}, pmid = {29478272}, issn = {1550-7408}, mesh = {Dinoflagellida/classification/enzymology/*genetics ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Phylogeny ; Plastids/*enzymology/genetics ; Protozoan Proteins/*genetics ; }, abstract = {The ancestral kareniacean dinoflagellate has undergone tertiary endosymbiosis, in which the original plastid is replaced by a haptophyte endosymbiont. During this plastid replacement, the endosymbiont genes were most likely flowed into the host dinoflagellate genome (endosymbiotic gene transfer or EGT). Such EGT may have generated the redundancy of functionally homologous genes in the host genome-one has resided in the host genome prior to the haptophyte endosymbiosis, while the other transferred from the endosymbiont genome. However, it remains to be well understood how evolutionarily distinct but functionally homologous genes were dealt in the dinoflagellate genomes bearing haptophyte-derived plastids. To model the gene evolution after EGT in plastid replacement, we here compared the characteristics of the two evolutionally distinct genes encoding plastid-type glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in Karenia brevis and K. mikimotoi bearing haptophyte-derived tertiary plastids: "gapC1h" acquired from the haptophyte endosymbiont and "gapC1p" inherited from the ancestral dinoflagellate. Our experiments consistently and clearly demonstrated that, in the two species examined, the principal plastid-type GAPDH is encoded by gapC1h rather than gapC1p. We here propose an evolutionary scheme resolving the EGT-derived redundancy of genes involved in plastid function and maintenance in the nuclear genomes of dinoflagellates that have undergone plastid replacements. Although K. brevis and K. mikimotoi are closely related to each other, the statuses of the two evolutionarily distinct gapC1 genes in the two Karenia species correspond to different steps in the proposed scheme.}, }
@article {pmid29477059, year = {2018}, author = {Gerrity, D and Arnold, M and Dickenson, E and Moser, D and Sackett, JD and Wert, EC}, title = {Microbial community characterization of ozone-biofiltration systems in drinking water and potable reuse applications.}, journal = {Water research}, volume = {135}, number = {}, pages = {207-219}, doi = {10.1016/j.watres.2018.02.023}, pmid = {29477059}, issn = {1879-2448}, mesh = {Bacteria/classification/genetics/*isolation &amp; purification/metabolism ; Biodiversity ; Charcoal/chemistry ; Drinking Water/chemistry/*microbiology ; Filtration/methods ; Ozone/*chemistry ; Waste Water/chemistry/microbiology ; Water Purification/methods ; Water Quality ; }, abstract = {Microbial community structure in the ozone-biofiltration systems of two drinking water and two wastewater treatment facilities was characterized using 16S rRNA gene sequencing. Collectively, these datasets enabled comparisons by facility, water type (drinking water, wastewater), pre-oxidation (ozonation, chlorination), media type (anthracite, activated carbon), media depth, and backwash dynamics. Proteobacteria was the most abundant phylum in drinking water filters, whereas Bacteroidetes, Chloroflexi, Firmicutes, and Planctomycetes were differentially abundant in wastewater filters. A positive correlation was observed between media depth and relative abundance of Cyanobacteria in drinking water filters, but there was only a slight increase in one alpha diversity metric with depth in the wastewater filters. Media type had a significant effect on beta but not alpha diversity in drinking water and wastewater filters. Pre-ozonation caused a significant decrease in alpha diversity in the wastewater filters, but the effect on beta diversity was not statistically significant. An evaluation of backwash dynamics resulted in two notable observations: (1) endosymbionts such as Neochlamydia and Legionella increased in relative abundance following backwashing and (2) nitrogen-fixing Bradyrhizobium dominated the microbial community in wastewater filters operated with infrequent backwashing. Bradyrhizobium is known to generate extracellular polymeric substances (EPS), which may adversely impact biofilter performance and effluent water quality. These findings have important implications for public health and the operation and resiliency of biofiltration systems.}, }
@article {pmid29476142, year = {2018}, author = {Desirò, A and Hao, Z and Liber, JA and Benucci, GMN and Lowry, D and Roberson, R and Bonito, G}, title = {Mycoplasma-related endobacteria within Mortierellomycotina fungi: diversity, distribution and functional insights into their lifestyle.}, journal = {The ISME journal}, volume = {12}, number = {7}, pages = {1743-1757}, pmid = {29476142}, issn = {1751-7370}, mesh = {Biodiversity ; Burkholderia/classification/genetics/isolation &amp; purification/*physiology ; Fungi/chemistry/*physiology ; Mycoplasma/classification/genetics/isolation &amp; purification/*physiology ; Phylogeny ; *Symbiosis ; }, abstract = {Bacterial interactions with animals and plants have been examined for over a century; by contrast, the study of bacterial-fungal interactions has received less attention. Bacteria interact with fungi in diverse ways, and endobacteria that reside inside fungal cells represent the most intimate interaction. The most significant bacterial endosymbionts that have been studied are associated with Mucoromycota and include two main groups: Burkholderia-related and Mycoplasma-related endobacteria (MRE). Examples of Burkholderia-related endobacteria have been reported in the three Mucoromycota subphyla. By contrast, MRE have only been identified in Glomeromycotina and Mucoromycotina. This study aims to understand whether MRE dwell in Mortierellomycotina and, if so, to determine their impact on the fungal host. We carried out a large-scale screening of 394 Mortierellomycotina strains and employed a combination of microscopy, molecular phylogeny, next-generation sequencing and qPCR. We detected MRE in 12 strains. These endosymbionts represent novel bacterial phylotypes and show evidence of recombination. Their presence in Mortierellomycotina demonstrates that MRE occur within fungi across Mucoromycota and they may have lived in their common ancestor. We cured the fungus of its endosymbionts with antibiotics and observed improved biomass production in isogenic lines lacking MRE, demonstrating that these endobacteria impose some fitness costs to their fungal host. Here we provided the first functional insights into the lifestyle of MRE. Our findings indicate that MRE may be antagonistic to their fungal hosts, and adapted to a non-lethal parasitic lifestyle in the mycelium of Mucoromycota. However, context-dependent adaptive benefits to their host at minimal cost cannot not be excluded. Finally, we conclude that Mortierellomycotina represent attractive model organisms for exploring interactions between MRE and fungi.}, }
@article {pmid29472284, year = {2018}, author = {Raina, JB and Eme, L and Pollock, FJ and Spang, A and Archibald, JM and Williams, TA}, title = {Symbiosis in the microbial world: from ecology to genome evolution.}, journal = {Biology open}, volume = {7}, number = {2}, pages = {}, pmid = {29472284}, issn = {2046-6390}, abstract = {The concept of symbiosis - defined in 1879 by de Bary as 'the living together of unlike organisms' - has a rich and convoluted history in biology. In part, because it questioned the concept of the individual, symbiosis fell largely outside mainstream science and has traditionally received less attention than other research disciplines. This is gradually changing. In nature organisms do not live in isolation but rather interact with, and are impacted by, diverse beings throughout their life histories. Symbiosis is now recognized as a central driver of evolution across the entire tree of life, including, for example, bacterial endosymbionts that provide insects with vital nutrients and the mitochondria that power our own cells. Symbioses between microbes and their multicellular hosts also underpin the ecological success of some of the most productive ecosystems on the planet, including hydrothermal vents and coral reefs. In November 2017, scientists working in fields spanning the life sciences came together at a Company of Biologists' workshop to discuss the origin, maintenance, and long-term implications of symbiosis from the complementary perspectives of cell biology, ecology, evolution and genomics, taking into account both model and non-model organisms. Here, we provide a brief synthesis of the fruitful discussions that transpired.}, }
@article {pmid29471857, year = {2018}, author = {Di Lecce, I and Bazzocchi, C and Cecere, JG and Epis, S and Sassera, D and Villani, BM and Bazzi, G and Negri, A and Saino, N and Spina, F and Bandi, C and Rubolini, D}, title = {Patterns of Midichloria infection in avian-borne African ticks and their trans-Saharan migratory hosts.}, journal = {Parasites &amp; vectors}, volume = {11}, number = {1}, pages = {106}, pmid = {29471857}, issn = {1756-3305}, mesh = {Africa, Northern ; Alphaproteobacteria/classification/genetics/*isolation &amp; purification ; *Animal Migration ; Animals ; Bird Diseases/blood/*microbiology/*parasitology ; DNA, Bacterial/genetics ; Disease Transmission, Infectious/statistics &amp; numerical data/*veterinary ; Europe ; Ixodidae/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Songbirds/blood/microbiology/parasitology/physiology ; Species Specificity ; Tick Infestations/blood/microbiology/parasitology/*veterinary ; }, abstract = {BACKGROUND: Ticks are obligate haematophagous ectoparasites of vertebrates and frequently parasitize avian species that can carry them across continents during their long-distance migrations. Ticks may have detrimental effects on the health state of their avian hosts, which can be either directly caused by blood-draining or mediated by microbial pathogens transmitted during the blood meal. Indeed, ticks host complex microbial communities, including bacterial pathogens and symbionts. Midichloria bacteria (Rickettsiales) are widespread tick endosymbionts that can be transmitted to vertebrate hosts during the tick bite, inducing an antibody response. Their actual role as infectious/pathogenic agents is, however, unclear.<br><br>METHODS: We screened for Midichloria DNA African ticks and blood samples collected from trans-Saharan migratory songbirds at their arrival in Europe during spring migration.<br><br>RESULTS: Tick infestation rate was 5.7%, with most ticks belonging to the Hyalomma marginatum species complex. Over 90% of Hyalomma ticks harboured DNA of Midichloria bacteria belonging to the monophylum associated with ticks. Midichloria DNA was detected in 43% of blood samples of avian hosts. Tick-infested adult birds were significantly more likely to test positive to the presence of Midichloria DNA than non-infested adults and second-year individuals, suggesting a long-term persistence of these bacteria within avian hosts. Tick parasitism was associated with a significantly delayed timing of spring migration of avian hosts but had no significant effects on body condition, whereas blood Midichloria DNA presence negatively affected fat deposits of tick-infested avian hosts.<br><br>CONCLUSIONS: Our results show that ticks effectively transfer Midichloria bacteria to avian hosts, supporting the hypothesis that they are infectious to vertebrates. Bird infection likely enhances the horizontal spread of these bacteria across haematophagous ectoparasite populations. Moreover, we showed that Midichloria and tick parasitism have detrimental non-independent effects on avian host health during migration, highlighting the complexity of interactions involving ticks, their vertebrate hosts, and tick-borne bacteria.}, }
@article {pmid29468305, year = {2018}, author = {Ramalho, MO and Vieira, AS and Pereira, MC and Moreau, CS and Bueno, OC}, title = {Transovarian Transmission of Blochmannia and Wolbachia Endosymbionts in the Neotropical Weaver Ant Camponotus textor (Hymenoptera, Formicidae).}, journal = {Current microbiology}, volume = {75}, number = {7}, pages = {866-873}, pmid = {29468305}, issn = {1432-0991}, mesh = {Animals ; Ants/growth &amp; development/*microbiology ; Enterobacteriaceae/classification/genetics/*isolation &amp; purification/physiology ; Female ; In Situ Hybridization, Fluorescence ; Ovary/growth &amp; development/microbiology ; Ovum/growth &amp; development/microbiology ; *Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Camponotus is a hyper-diverse ant genus that is associated with the obligate endosymbiont Blochmannia, and often also with Wolbachia, but morphological studies on the location of these bacteria in the queen's ovaries during oogenesis remain limited. In the present study, we used the Neotropical weaver ant Camponotus textor to characterize the ovary using histology (HE) techniques, and to document the location of Blochmannia and Wolbachia during oogenesis through fluorescence in situ hybridization (FISH). This is the first morphological report of these two bacteria in the same host with polytrophic meroistic ovaries and reveals that Blochmannia is found inside late-stage oocytes and Wolbachia is associated with the nuclei of the nurse cells. Our results provide insights into the developmental sequence of when these bacteria reach the egg, with Blochmannia establishing itself in the egg first, and Wolbachia only reaching the egg shortly before completing egg development. Studies such as this provide understanding about the mechanisms and timing of the establishment of these endosymbionts in the host.}, }
@article {pmid29468040, year = {2018}, author = {Pogoreutz, C and Rädecker, N and Cárdenas, A and Gärdes, A and Wild, C and Voolstra, CR}, title = {Dominance of Endozoicomonas bacteria throughout coral bleaching and mortality suggests structural inflexibility of the Pocillopora verrucosa microbiome.}, journal = {Ecology and evolution}, volume = {8}, number = {4}, pages = {2240-2252}, pmid = {29468040}, issn = {2045-7758}, abstract = {The importance of Symbiodinium algal endosymbionts and a diverse suite of bacteria for coral holobiont health and functioning are widely acknowledged. Yet, we know surprisingly little about microbial community dynamics and the stability of host-microbe associations under adverse environmental conditions. To gain insight into the stability of coral host-microbe associations and holobiont structure, we assessed changes in the community structure of Symbiodinium and bacteria associated with the coral Pocillopora verrucosa under excess organic nutrient conditions. Pocillopora-associated microbial communities were monitored over 14 days in two independent experiments. We assessed the effect of excess dissolved organic nitrogen (DON) and excess dissolved organic carbon (DOC). Exposure to excess nutrients rapidly affected coral health, resulting in two distinct stress phenotypes: coral bleaching under excess DOC and severe tissue sloughing (>90% tissue loss resulting in host mortality) under excess DON. These phenotypes were accompanied by structural changes in the Symbiodinium community. In contrast, the associated bacterial community remained remarkably stable and was dominated by two Endozoicomonas phylotypes, comprising on average 90% of 16S rRNA gene sequences. This dominance of Endozoicomonas even under conditions of coral bleaching and mortality suggests the bacterial community of P. verrucosa may be rather inflexible and thereby unable to respond or acclimatize to rapid changes in the environment, contrary to what was previously observed in other corals. In this light, our results suggest that coral holobionts might occupy structural landscapes ranging from a highly flexible to a rather inflexible composition with consequences for their ability to respond to environmental change.}, }
@article {pmid29467748, year = {2018}, author = {Rodriguez, IB and Ho, TY}, title = {Trace Metal Requirements and Interactions in Symbiodinium kawagutii.}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {142}, pmid = {29467748}, issn = {1664-302X}, abstract = {Photosynthetic organisms need trace metals for various biological processes and different groups of microalgae have distinctive obligate necessities due to their respective biochemical requirements and ecological niches. We have previously shown that the dinoflagellate Symbiodinium kawagutii requires high concentrations of bioavailable Fe to achieve optimum growth. Here, we further explored the trace metal requirements of S. kawagutii with intensive focus on the effect of individual metal and its interaction with other divalent metals. We found that low Zn availability significantly decreases growth rates and results in elevated intracellular Mn, Co, Ni, and Fe quotas in the dinoflagellate. The results highlight the complex interaction among trace metals in S. kawagutii and suggest either metal replacement strategy to counter low Zn availability or enhanced uptake of other metals by non-specific divalent metal transporters. In this work, we also examined the Fe requirement of S. kawagutii using continuous cultures. We validated that 500 pM of Fe' was sufficient to support maximum cell density during steady state growth period either at 26 or 28°C. This study shows that growth of S. kawagutii was limited by metal availability in the following order, Fe > Zn > Mn > Cu > Ni > Co. The fundamental information obtained for the free-living Symbiodinium shall provide insights into how trace metal availability, either from ambient seawater or hosts, affects growth and proliferation of symbiotic dinoflagellates and the interaction between symbiont and their hosts.}, }
@article {pmid29467742, year = {2018}, author = {Borghesan, TC and Campaner, M and Matsumoto, TE and Espinosa, OA and Razafindranaivo, V and Paiva, F and Carranza, JC and Añez, N and Neves, L and Teixeira, MMG and Camargo, EP}, title = {Genetic Diversity and Phylogenetic Relationships of Coevolving Symbiont-Harboring Insect Trypanosomatids, and Their Neotropical Dispersal by Invader African Blowflies (Calliphoridae).}, journal = {Frontiers in microbiology}, volume = {9}, number = {}, pages = {131}, pmid = {29467742}, issn = {1664-302X}, abstract = {This study is about the inter- and intra-specific genetic diversity of trypanosomatids of the genus Angomonas, and their association with Calliphoridae (blowflies) in Neotropical and Afrotropical regions. Microscopic examination of 3,900 flies of various families, mostly Calliphoridae, revealed that 31% of them harbored trypanosomatids. Small subunit rRNA (SSU rRNA) barcoding showed that Angomonas predominated (46%) over the other common trypanosomatids of blowflies of genera Herpetomonas and Wallacemonas. Among Angomonas spp., A. deanei was much more common than the two-other species, A. desouzai and A. ambiguus. Phylogenetic analyses based on SSU rRNA, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) and internal transcribed spacer rDNA (ITS rDNA) sequences revealed a marked genetic diversity within A. deanei, which comprised four infraspecific genotypes (Dea1-Dea4), and four corresponding symbiont genotypes (Kcr1-Kcr4). Host and symbiont phylogenies were highly congruent corroborating their co-divergence, consistent with host-symbiont interdependent metabolism and symbiont reduced genomes shaped by a long coevolutionary history. We compared the diversity of Angomonas/symbionts from three genera of blowflies, Lucilia, Chrysomya and Cochliomyia. A. deanei, A. desouzai, and A. ambiguus were found in the three genera of blowflies in South America. In Africa, A. deanei and A. ambiguus were identified in Chrysomya. The absence of A. desouzai in Africa and its presence in Neotropical Cochliomyia and Lucilia suggests parasite spillback of A. desouzai into Chrysomya, which was most likely introduced four decades ago from Africa into the Neotropic. The absence of correlation between parasite diversity and geographic and genetic distances, with identical genotypes of A. deanei found in the Neotropic and Afrotropic, is consistent with disjunct distribution due to the recent human-mediated transoceanic dispersal of Angomonas by Chrysomya. This study provides the most comprehensive data gathered so far on the genetic repertoires of a genus of trypanosomatids found in flies from a wide geographical range.}, }
@article {pmid29467241, year = {2018}, author = {Kamath, AD and Deehan, MA and Frydman, HM}, title = {Polar cell fate stimulates Wolbachia intracellular growth.}, journal = {Development (Cambridge, England)}, volume = {145}, number = {6}, pages = {}, pmid = {29467241}, issn = {1477-9129}, support = {R56 AI097589/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Drosophila/*microbiology ; Female ; Fluorescent Antibody Technique ; In Situ Hybridization, Fluorescence ; Oogenesis/physiology ; Ovary/cytology/microbiology ; Polar Bodies/*microbiology ; Symbiosis/*physiology ; Viral Tropism/*physiology ; Wolbachia/*pathogenicity ; }, abstract = {Bacteria are crucial partners in the development and evolution of vertebrates and invertebrates. A large fraction of insects harbor Wolbachia, bacterial endosymbionts that manipulate host reproduction to favor their spreading. Because they are maternally inherited, Wolbachia are under selective pressure to reach the female germline and infect the offspring. However, Wolbachia infection is not limited to the germline. Somatic cell types, including stem cell niches, have higher Wolbachia loads compared with the surrounding tissue. Here, we show a novel Wolbachia tropism to polar cells (PCs), specialized somatic cells in the Drosophila ovary. During oogenesis, all stages of PC development are easily visualized, facilitating the investigation of the kinetics of Wolbachia intracellular growth. Wolbachia accumulation is triggered by particular events of PC morphogenesis, including differentiation from progenitors and between stages 8 and 9 of oogenesis. Moreover, induction of ectopic PC fate is sufficient to promote Wolbachia accumulation. We found that Wolbachia PC tropism is evolutionarily conserved across most Drosophila species, but not in Culex mosquitos. These findings highlight the coordination of endosymbiont tropism with host development and cell differentiation.}, }
@article {pmid29466376, year = {2018}, author = {Yadav, S and Frazer, J and Banga, A and Pruitt, K and Harsh, S and Jaenike, J and Eleftherianos, I}, title = {Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.}, journal = {PloS one}, volume = {13}, number = {2}, pages = {e0192183}, pmid = {29466376}, issn = {1932-6203}, mesh = {Animals ; Drosophila melanogaster/*immunology/microbiology/parasitology ; Host-Parasite Interactions ; Nematoda/*physiology ; *Symbiosis ; Wolbachia/isolation &amp; purification ; }, abstract = {Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.}, }
@article {pmid29463894, year = {2018}, author = {Nielsen, DA and Petrou, K and Gates, RD}, title = {Coral bleaching from a single cell perspective.}, journal = {The ISME journal}, volume = {12}, number = {6}, pages = {1558-1567}, pmid = {29463894}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*physiology ; *Coral Reefs ; Dinoflagellida/*physiology ; Fluorescent Dyes/chemistry ; Glutathione/metabolism ; Hawaii ; Lipid Peroxidation ; Microscopy, Confocal ; Oxidative Stress ; Reactive Oxygen Species/metabolism ; Stress, Physiological ; Symbiosis/*physiology ; Temperature ; }, abstract = {Ocean warming is resulting in increased occurrence of mass coral bleaching; a response in which the intracellular algal endosymbionts (Symbiodinium sp.) are expelled from the coral host due to physiological stress. This detrimental process is often attributed to overproduction of reactive oxygen species (ROS) that leak out of the endosymbionts and causes damage to the host cell, though direct evidence validating this link is limited. Here, for the first time, we used confocal microscopy and fluorescent dyes to investigate if endosymbiont ROS production significantly and predictably affects physiological parameters in its host cell. Heat treatment resulted in a 60% reduction in coral symbiont density, a ~70% increase in median endosymbiont ROS and a small reduction in photosystem efficiency (FV/FM, 11%), indicating absence of severe light stress. Notably, no other physiological parameters were affected in either endosymbionts or host cells, including reduced glutathione and ROS-induced lipid peroxidation. Taken together, the increase in endosymbiont ROS could not be linked to physiological damage in either partner, suggesting that oxidative stress is unlikely to have been the driver for symbiont expulsion in this study.}, }
@article {pmid29463295, year = {2018}, author = {Brener-Raffalli, K and Clerissi, C and Vidal-Dupiol, J and Adjeroud, M and Bonhomme, F and Pratlong, M and Aurelle, D and Mitta, G and Toulza, E}, title = {Thermal regime and host clade, rather than geography, drive Symbiodinium and bacterial assemblages in the scleractinian coral Pocillopora damicornis sensu lato.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {39}, pmid = {29463295}, issn = {2049-2618}, support = {ANR-12-ADAP-0016//Agence Nationale de la Recherche/International ; }, mesh = {Acinetobacter/genetics/*isolation &amp; purification ; Animals ; Anthozoa/*microbiology/*parasitology ; Arcobacter/genetics/*isolation &amp; purification ; DNA, Intergenic/genetics ; Dinoflagellida/genetics/*isolation &amp; purification ; High-Throughput Nucleotide Sequencing ; Microbiota/genetics ; Oceanospirillaceae/genetics/*isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Symbiosis/physiology ; }, abstract = {BACKGROUND: Although the term holobiont has been popularized in corals with the advent of the hologenome theory of evolution, the underlying concepts are still a matter of debate. Indeed, the relative contribution of host and environment and especially thermal regime in shaping the microbial communities should be examined carefully to evaluate the potential role of symbionts for holobiont adaptation in the context of global changes. We used the sessile, long-lived, symbiotic and environmentally sensitive reef-building coral Pocillopora damicornis to address these issues.<br><br>RESULTS: We sampled Pocillopora damicornis colonies corresponding to two different mitochondrial lineages in different geographic areas displaying different thermal regimes: Djibouti, French Polynesia, New Caledonia, and Taiwan. The community composition of bacteria and the algal endosymbiont Symbiodinium were characterized using high-throughput sequencing of 16S rRNA gene and internal transcribed spacer, ITS2, respectively. Bacterial microbiota was very diverse with high prevalence of Endozoicomonas, Arcobacter, and Acinetobacter in all samples. While Symbiodinium sub-clade C1 was dominant in Taiwan and New Caledonia, D1 was dominant in Djibouti and French Polynesia. Moreover, we also identified a high background diversity (i.e., with proportions <&#x2009;1%) of A1, C3, C15, and G Symbiodinum sub-clades. Using redundancy analyses, we found that the effect of geography was very low for both communities and that host genotypes and temperatures differently influenced Symbiodinium and bacterial microbiota. Indeed, while the constraint of host haplotype was higher than temperatures on bacterial composition, we showed for the first time a strong relationship between the composition of Symbiodinium communities and minimal sea surface temperatures.<br><br>CONCLUSION: Because Symbiodinium assemblages are more constrained by the thermal regime than bacterial communities, we propose that their contribution to adaptive capacities of the holobiont to temperature changes might be higher than the influence of bacterial microbiota. Moreover, the link between Symbiodinium community composition and minimal temperatures suggests low relative fitness of clade D at lower temperatures. This observation is particularly relevant in the context of climate change, since corals will face increasing temperatures as well as much frequent abnormal cold episodes in some areas of the world.}, }
@article {pmid29462313, year = {2018}, author = {Torres, MJ and Avila, S and Bedmar, EJ and Delgado, MJ}, title = {Overexpression of the periplasmic nitrate reductase supports anaerobic growth by Ensifer meliloti.}, journal = {FEMS microbiology letters}, volume = {365}, number = {7}, pages = {}, doi = {10.1093/femsle/fny041}, pmid = {29462313}, issn = {1574-6968}, mesh = {Anaerobiosis ; Bacterial Proteins/*genetics/metabolism ; Nitrate Reductase/*genetics/metabolism ; Nitrates/metabolism ; Nitric Oxide/metabolism ; Nitrites/metabolism ; Periplasm/*enzymology/genetics ; Sinorhizobium meliloti/*enzymology/genetics/*growth &amp; development/metabolism ; }, abstract = {The alfalfa endosymbiont Ensifer meliloti strain1021 is known to be an incomplete denitrifier due to its inability to grow anoxically using nitrate as respiratory substrate to produce ATP and grow under anoxic conditions. Although this bacterium contains and expresses the complete set of denitrification genes napEFDABC, nirK, norECBQD and nosRZDFYLX encoding the periplasmic nitrate reductase (Nap), Cu-containing nitrite reductase (NirK), c-type nitric oxide (cNor) and nitrous oxide reductase (Nos), respectively, the reasons of its inability to grow under anoxic conditions are still very poorly understood. In the present study, we have constructed an E. meliloti strain overexpressing napEFDABC genes (Nap+) and demonstrated that this strain is able to grow through anaerobic nitrate respiration. Furthermore, Nap+ showed increased NapC levels as well as Nap, Nir and cNor activities and higher capacity to produce NO and N2O compared to wild-type cells. These results suggest that the inability of E. meliloti to grow under anaerobic conditions using nitrate as electron acceptor is attributable to a limitation in the expression of the periplasmic nitrate reductase.}, }
@article {pmid29452844, year = {2018}, author = {Shen, Q and Liu, Y and Naqvi, NI}, title = {Fungal effectors at the crossroads of phytohormone signaling.}, journal = {Current opinion in microbiology}, volume = {46}, number = {}, pages = {1-6}, doi = {10.1016/j.mib.2018.01.006}, pmid = {29452844}, issn = {1879-0364}, mesh = {Fungal Proteins/genetics/*metabolism ; Fungi/genetics/*metabolism ; Host-Pathogen Interactions ; Plant Diseases/*microbiology ; Plant Growth Regulators/*metabolism ; Plants/metabolism/*microbiology ; Signal Transduction ; }, abstract = {Phytohormone networks are crucial for maintaining the delicate balance between growth and biotic stress responses in plants. Jasmonic acid, salicylic acid, ethylene, and the associated signaling crosstalk are important for pathogen defense; whereas gibberellin and cytokinin function in growth and development in plants. Plant pathogenic fungi have evolved remarkable strategies to manipulate and/or hijack such phytohormone signaling cascades for their own benefit, thus leading to susceptibility and disease in host plants. Interestingly, these hormones are also targeted by fungal endosymbionts and mutualists during beneficial interactions with plants. We highlight current advances in our understanding of the role of fungal effectors in such antagonistic manipulation of phytohormones during pathogenic as well as symbiotic association with plant hosts. In addition to the aforementioned effector-based control, certain phytohormone mimics have recently emerged as a powerful molecular language in fungal manipulation of defense responses and innate immunity in plants.}, }
@article {pmid29436502, year = {2018}, author = {Hörandl, E and Speijer, D}, title = {How oxygen gave rise to eukaryotic sex.}, journal = {Proceedings. Biological sciences}, volume = {285}, number = {1872}, pages = {}, pmid = {29436502}, issn = {1471-2954}, mesh = {*Biological Evolution ; Eukaryota/*physiology ; Oxygen/*metabolism ; Reactive Oxygen Species/metabolism ; *Sex ; Symbiosis/physiology ; }, abstract = {How did full meiotic eukaryotic sex evolve and what was the immediate advantage allowing it to develop? We propose that the crucial determinant can be found in internal reactive oxygen species (ROS) formation at the start of eukaryotic evolution approximately 2 × 10[9] years ago. The large amount of ROS coming from a bacterial endosymbiont gave rise to DNA damage and vast increases in host genome mutation rates. Eukaryogenesis and chromosome evolution represent adaptations to oxidative stress. The host, an archaeon, most probably already had repair mechanisms based on DNA pairing and recombination, and possibly some kind of primitive cell fusion mechanism. The detrimental effects of internal ROS formation on host genome integrity set the stage allowing evolution of meiotic sex from these humble beginnings. Basic meiotic mechanisms thus probably evolved in response to endogenous ROS production by the 'pre-mitochondrion'. This alternative to mitosis is crucial under novel, ROS-producing stress situations, like extensive motility or phagotrophy in heterotrophs and endosymbiontic photosynthesis in autotrophs. In multicellular eukaryotes with a germline-soma differentiation, meiotic sex with diploid-haploid cycles improved efficient purging of deleterious mutations. Constant pressure of endogenous ROS explains the ubiquitous maintenance of meiotic sex in practically all eukaryotic kingdoms. Here, we discuss the relevant observations underpinning this model.}, }
@article {pmid29435771, year = {2018}, author = {Zélé, F and Weill, M and Magalhães, S}, title = {Identification of spider-mite species and their endosymbionts using multiplex PCR.}, journal = {Experimental &amp; applied acarology}, volume = {74}, number = {2}, pages = {123-138}, pmid = {29435771}, issn = {1572-9702}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Female ; Male ; *Microbiota ; Multiplex Polymerase Chain Reaction/economics/*methods ; Portugal ; Spain ; *Symbiosis ; Tetranychidae/*classification/genetics/microbiology ; }, abstract = {Spider mites of the genus Tetranychidae are severe crop pests. In the Mediterranean a few species coexist, but they are difficult to identify based on morphological characters. Additionally, spider mites often harbour several species of endosymbiotic bacteria, which may affect the biology of their hosts. Here, we propose novel, cost-effective, multiplex diagnostic methods allowing a quick identification of spider-mite species as well as of the endosymbionts they carry. First, we developed, and successfully multiplexed in a single PCR, primers to identify Tetranychus urticae, T. evansi and T. ludeni, some of the most common tetranychids found in southwest Europe. Moreover, we demonstrated that this method allows detecting multiple species in a single pool, even at low frequencies (up to 1/100), and can be used on entire mites without DNA extraction. Second, we developed another set of primers to detect spider-mite endosymbionts, namely Wolbachia, Cardinium and Rickettsia in a multiplex PCR, along with a generalist spider-mite primer to control for potential failure of DNA amplification in each PCR. Overall, our method represents a simple, cost-effective and reliable method to identify spider-mite species and their symbionts in natural field populations, as well as to detect contaminations in laboratory rearings. This method may easily be extended to other species.}, }
@article {pmid29435238, year = {2018}, author = {Zhang, YK and Yang, K and Zhu, YX and Hong, XY}, title = {Symbiont-conferred reproduction and fitness benefits can favour their host occurrence.}, journal = {Ecology and evolution}, volume = {8}, number = {3}, pages = {1626-1633}, pmid = {29435238}, issn = {2045-7758}, abstract = {Double infections of Wolbachia and Spiroplasma are frequent in natural populations of Tetranychus truncatus, a polyphagous mite species that has been a dominant species in China since 2009. However, little is known about the causes and ecological importance of such coexistences. In this study, we established T. truncatus strains with different infection types and then inferred the impact of the two endosymbionts on host reproduction and fitness. Double infection induced cytoplasmic incompatibility, which was demonstrated by reduction in egg hatchability of incompatible crosses. However, doubly infected females produced more eggs relative to other strains. Wolbachia and Spiroplasma did not affect host survival, whereas doubly infected females and males developed faster than other strains. Such reproduction and fitness benefits provided by double infections may be associated with the lower densities of each symbiont, and the quantitative results also confirmed competition between Wolbachia and Spiroplasma in doubly infected females. These symbiont-conferred beneficial effects maintain stable prevalence of the symbionts and also help drive T. truncatus outbreaks in combination with other environmental factors.}, }
@article {pmid29432146, year = {2018}, author = {Simonet, P and Gaget, K and Balmand, S and Ribeiro Lopes, M and Parisot, N and Buhler, K and Duport, G and Vulsteke, V and Febvay, G and Heddi, A and Charles, H and Callaerts, P and Calevro, F}, title = {Bacteriocyte cell death in the pea aphid/Buchnera symbiotic system.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {8}, pages = {E1819-E1828}, pmid = {29432146}, issn = {1091-6490}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*physiology ; Cell Death ; Lysosomes ; Symbiosis/*physiology ; }, abstract = {Symbiotic associations play a pivotal role in multicellular life by facilitating acquisition of new traits and expanding the ecological capabilities of organisms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells (bacteriocytes) or organs (bacteriomes) have evolved for harboring beneficial microbial partners. The processes regulating the cellular life cycle of these endosymbiont-bearing cells, such as the cell-death mechanisms controlling their fate and elimination in response to host physiology, are fundamental questions in the biology of symbiosis. Here we report the discovery of a cell-death process involved in the degeneration of bacteriocytes in the hemipteran insect Acyrthosiphon pisum This process is activated progressively throughout aphid adulthood and exhibits morphological features distinct from known cell-death pathways. By combining electron microscopy, immunohistochemistry, and molecular analyses, we demonstrated that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of nonautophagic vacuoles, followed by a sequence of cellular stress responses including the formation of autophagosomes in intervacuolar spaces, activation of reactive oxygen species, and Buchnera endosymbiont degradation by the lysosomal system. We showed that this multistep cell-death process originates from the endoplasmic reticulum, an organelle exhibiting a unique reticular network organization spread throughout the entire cytoplasm and surrounding Buchnera aphidicola endosymbionts. Our findings provide insights into the cellular and molecular processes that coordinate eukaryotic host and endosymbiont homeostasis and death in a symbiotic system and shed light on previously unknown aspects of bacteriocyte biological functioning.}, }
@article {pmid29426636, year = {2018}, author = {Schrallhammer, M and Castelli, M and Petroni, G}, title = {Phylogenetic relationships among endosymbiotic R-body producer: Bacteria providing their host the killer trait.}, journal = {Systematic and applied microbiology}, volume = {41}, number = {3}, pages = {213-220}, doi = {10.1016/j.syapm.2018.01.005}, pmid = {29426636}, issn = {1618-0984}, mesh = {Alphaproteobacteria/*classification/genetics ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; Paramecium/*microbiology/physiology ; Phenotype ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {R-body producing bacterial endosymbionts of Paramecium spp. transform their hosts into "killer" paramecia and provide them a selective advantage. This killer trait is connected to the presence of R-bodies, which are peculiar, tightly coiled protein ribbons capable of rapid unrolling. Based mainly on those two characteristics the respective obligate intracellular bacteria have been comprised in the genus Caedibacter and additional traits such as host species, subcellular localization, and R-body dimensions and mode of unrolling were used for species discrimination. Previous studies applying the full-cycle rRNA approach demonstrated the polyphyly of this assemblage. Following this approach, we obtained new sequences and in situ hybridizations for five strains of Caedibacter taeniospiralis and four strains associated to Caedibacter varicaedens and Caedibacter caryophilus. Detailed phylogenetic reconstructions confirm the association of C. taeniospiralis to Fastidiosibacteraceae and to Holosporales in case of the others. Therefore, we critically revise the taxonomy of the latter group. The high 16S rRNA gene sequence similarity among the type strains of Caedibacter varicaedens and C. caryophilus indicate that they should be classified within a single species for which we propose Caedimonas varicaedens comb. nov. owing to the priority of Caedibacter varicaedens. Moreover, we propose to establish the new family Caedimonadaceae fam. nov. to encompass Caedimonas varicaedens, "Ca. Paracaedimonas acanthamoebae" comb. nov. and "Ca. Nucleicultrix amoebiphila" within the order Holosporales.}, }
@article {pmid29426479, year = {2018}, author = {Otranto, D}, title = {Arthropod-borne pathogens of dogs and cats: From pathways and times of transmission to disease control.}, journal = {Veterinary parasitology}, volume = {251}, number = {}, pages = {68-77}, doi = {10.1016/j.vetpar.2017.12.021}, pmid = {29426479}, issn = {1873-2550}, mesh = {Animals ; Arthropod Vectors/*parasitology/*physiology ; Cat Diseases/drug therapy/parasitology/prevention &amp; control/transmission ; Cats/microbiology/parasitology ; Communicable Diseases, Emerging/drug therapy/prevention &amp; control/transmission/*veterinary ; *Disease Vectors ; Dog Diseases/drug therapy/epidemiology/prevention &amp; control/transmission ; Dogs/microbiology/parasitology ; Feeding Behavior ; Humans ; Isoxazoles/administration &amp; dosage/therapeutic use ; Parasitic Diseases, Animal/drug therapy/prevention &amp; control/transmission ; Pyrethrins/administration &amp; dosage/therapeutic use ; Zoonoses/drug therapy/parasitology/prevention &amp; control/*transmission ; }, abstract = {Vector-borne pathogens have developed a close relationship with blood feeding arthropod ectoparasites (e.g., mosquitoes, ticks, phlebotomine sand flies, black flies, fleas, kissing bugs, lice) and exploited a huge variety of vector transmission routes. Therefore, the life cycles of these pathogens result in a long evolved balance with the respective arthropod biology, ecology and blood feeding habits, instrumentally to the infection of several animal species, including humans. Amongst the many parasite transmission modes, such as ingestion of the arthropod, with its faeces or secretions, blood feeding represents the main focus for this article, as it is a central event to the life of almost all arthropod vectors. The time frame in which pathogens are transmitted to any animal host is governed by a large number of biological variables related to the vector, the pathogen, the host and environmental factors. Scientific data available on transmission times for each pathogen are discussed relative to their impact for the success of vector-borne disease control strategies. Blocking pathogen transmission, and thus preventing the infection of dogs and cats, may be achievable by the use of chemical compounds if they are characterised by a fast onset of killing activity or repellence against arthropods. The fast speed of kill exerted by systemic isoxazoline, as well as the repellent effect of pyrethroids have renewed the interest of the scientific community and pharmaceutical companies towards reducing the burden of vector-borne diseases under field conditions. However, endosymbionts and vaccines targeting arthropods or pathogen antigens should be further investigated as alternative strategies towards the goal of achieving an effective integrated control of vector-borne diseases.}, }
@article {pmid29425401, year = {2019}, author = {Zhang, JH and Yu, N and Xu, XX and Liu, ZW}, title = {Community structure, dispersal ability and functional profiling of microbiome existing in fat body and ovary of the brown planthopper, Nilaparvata lugens.}, journal = {Insect science}, volume = {26}, number = {4}, pages = {683-694}, doi = {10.1111/1744-7917.12575}, pmid = {29425401}, issn = {1744-7917}, mesh = {Animals ; Fat Body/*microbiology ; Female ; Hemiptera/*microbiology ; Metabolic Networks and Pathways ; Microbiota ; Ovary/microbiology ; }, abstract = {The endosymbionts play vital roles in growth, development and reproduction in insects. Yeast-like endosymbionts (YLSs) have been well studied in Nilaparvata lugens (N. lugens), but little is known about the tissue-specific bacterial microbiomes, especially on the microbial intersection among internal tissues. Here, the correlation of microbial composition, structure, dispersal ability and functional profiling were illuminated in two tissues, the fat body and ovary in N. lugens. A total of 11 phyla and 105 genera were captured from all samples; Firmicutes and Proteobacteria were the most predominant and accounted for more than 99% in all samples. However, the relative abundance of Firmicutes and Proteobacteria was significantly different in ovary and fat body through Fisher's Least Significant Difference test. Microbial diversity but not the richness index in the two tissues exhibited significant difference. Furthermore, the microbial community structure of the ovary and fat body were primarily determined by tissue quality. Firmicutes showed strong dispersal ability between ovary and fat body based on the quantitative null model assessing, indicating the frequent interaction of these microbiomes in the two tissues. In addition, the Kyoto Encyclopedia of Genes and Genomes pathways of microbial participation were delineated. The ten most abundant pathways counted for over 46% of the annotation and were shared between the two tissues, mainly containing Energy Metabolism and Amino Acid Metabolism/Biosynthesis. The results will provide insights into the correlation of microbial community structure between ovary and fat body of N. lugens.}, }
@article {pmid29423772, year = {2018}, author = {Cavaleiro, FI and Frade, DG and Rangel, LF and Santos, MJ}, title = {Syndesmis François, 1886 (Rhabdocoela: Umagillidae): a revisitation, with a synopsis and an identification key to species, and new molecular evidence for ascertaining the phylogeny of the group.}, journal = {Systematic parasitology}, volume = {95}, number = {2-3}, pages = {147-171}, doi = {10.1007/s11230-018-9781-5}, pmid = {29423772}, issn = {1573-5192}, support = {INSEAFOOD/BI/M3/2016-005//This work was partially supported by the Structured Program of R&amp;D&amp;I INNOVMAR - Innovation and Sustainability in the Management and Exploitation of Marine Resources, reference NORTE-01-0145-FEDER-000035, namely within the Research Line INSEAFOOD Innovation and valorization of seafood products: meeting local challenges and opportunities, within the R&amp;D Institution CIIMAR (Interdisciplinary Centre of Marine and Environmental Research), supported by the Northern Regional Operational Programme (NORTE2020), through the European Regional Development Fund (ERDF)./International ; }, mesh = {Animals ; *Phylogeny ; Platyhelminths/*classification/*genetics ; Sea Urchins/parasitology ; Species Specificity ; }, abstract = {Syndesmis François, 1886 is a genus of umagillid turbellarians comprising species which are typically endosymbionts of echinoids, i.e. sea urchins. This group is likely key in addressing the issue of transition between a free-living and a parasitic mode of life in the Platyhelminthes. Accordingly, its phylogeny should be considered for detailed analysis, namely by addressing molecular evidence for its different species. At the present time, a revisitation of Syndesmis is required and fully justified by the following lines of argument: (i) the body of knowledge on Syndesmis is large, but the information is scattered through many different works in the literature; (ii) for about 60 years, it was a common practice to assign the umagillids isolated from sea urchins as a single species, i.e. the type-species, Syndesmis echinorum François, 1886, which was later split into several species on morphological grounds; and (iii) the type-species - for which no molecular information is available - was redescribed and new species were described in recent years but the generic diagnosis of Syndesmis was not emended accordingly. The present state of art additionally justifies the necessity of (i) an updated synopsis of species and (ii) an identification key to the 26 species described from different hosts and geographical locations. All these aspects define the aims of the present study. It is proposed that S. antillarum is attributed to Stunkard &amp; Corliss (1951) and not to Powers (1936).}, }
@article {pmid29422444, year = {2018}, author = {Nowak, BF and Archibald, JM}, title = {Opportunistic but Lethal: The Mystery of Paramoebae.}, journal = {Trends in parasitology}, volume = {34}, number = {5}, pages = {404-419}, doi = {10.1016/j.pt.2018.01.004}, pmid = {29422444}, issn = {1471-5007}, support = {//CIHR/Canada ; }, mesh = {Amoebozoa/*parasitology/pathogenicity ; Animals ; Eukaryota/*physiology ; Parasitic Diseases, Animal/parasitology ; Research/trends ; *Symbiosis ; }, abstract = {Paramoebae are enigmatic single-celled eukaryotes that can be opportunistic pathogens of marine animals. For example, amoebic gill disease ravages farmed salmonids worldwide, causing tens of millions of dollars in losses annually. Although paramoebae can be found associated with animals ranging from fish and lobster to molluscs and sea urchins, how and how often they actually cause disease is unknown. Here we review recent progress towards understanding the biology and ecology of paramoebid species and the eukaryotic endosymbionts that live inside them. Genomic and transcriptomic sequence data serve as a platform upon which future research on paramoebiasis can build.}, }
@article {pmid29421139, year = {2018}, author = {Deschaseaux, E and Hardefeldt, J and Jones, G and Reichelt-Brushett, A}, title = {High zinc exposure leads to reduced dimethylsulfoniopropionate (DMSP) levels in both the host and endosymbionts of the reef-building coral Acropora aspera.}, journal = {Marine pollution bulletin}, volume = {126}, number = {}, pages = {93-100}, doi = {10.1016/j.marpolbul.2017.10.070}, pmid = {29421139}, issn = {1879-3363}, mesh = {Animals ; Anthozoa/*drug effects/metabolism/microbiology ; Coral Reefs ; Dinoflagellida/*drug effects/metabolism ; Sulfonium Compounds/*metabolism ; Symbiosis ; Zinc/metabolism/*toxicity ; }, abstract = {Dimethylsulfoniopropionate (DMSP) is a biogenic compound that could be involved in metal detoxification in both the host and endosymbionts of symbiotic corals. Acropora aspera, a common reef-building coral of the Great Barrier Reef, was exposed to zinc doses from 10 to 1000μg/L over 96h, with zinc being a low-toxic trace metal commonly used in the shipping industry. Over time, significantly lower DMSP concentrations relative to the control were found in both the host and symbionts in the highest zinc treatment where zinc uptake by both partners of the symbiosis was the highest. This clearly indicates that DMSP was consumed or stopped being produced under high and extended zinc exposure. This drop in DMSP was first observed in the host tissue, suggesting that the coral host was the first to respond to metal contamination. Such decrease in DMSP concentrations could influence the long-term health of corals under zinc exposure.}, }
@article {pmid29420776, year = {2018}, author = {Otero-Bravo, A and Goffredi, S and Sabree, ZL}, title = {Cladogenesis and Genomic Streamlining in Extracellular Endosymbionts of Tropical Stink Bugs.}, journal = {Genome biology and evolution}, volume = {10}, number = {2}, pages = {680-693}, pmid = {29420776}, issn = {1759-6653}, mesh = {Animals ; Citric Acid Cycle ; *Genetic Speciation ; *Genome, Bacterial ; Heteroptera/*microbiology ; Pantoea/*genetics/metabolism ; Symbiosis ; Terminology as Topic ; }, abstract = {Phytophagous stink bugs are globally distributed and many harbor vertically inherited bacterial symbionts that are extracellular, yet little is known about how the symbiont's genomes have evolved under this transmission strategy. Genome reduction is common in insect intracellular symbionts but limited genome sampling of the extracellular symbionts of distantly related stink bugs has precluded inferring patterns of extracellular symbiont genome evolution. To address this knowledge gap, we completely sequenced the genomes of the uncultivable bacterial symbionts of four neotropical stink bugs of the Edessa genus. Phylogenetic and comparative analyses indicated that the symbionts form a clade within the Pantoea genus and their genomes are highly reduced (∼0.8 Mb). Furthermore, genome synteny analysis and a jackknife approach for phylogenetic reconstruction, which corrected for long branch attraction artifacts, indicated that the Edessa symbionts were the result of a single symbiotic event that was distinct from the symbiosis event giving rise to Candidatus "Pantoea carbekii," the extracellular symbiont of the invasive pentatomid stink bug, Halyomorpha halys. Metabolic functions inferred from the Edessa symbiont genomes suggests a shift in genomic composition characteristic of its lifestyle in that they retained many host-supportive functions while undergoing dramatic gene loss and establishing a stable relationship with their host insects. Given the undersampled nature of extracellular insect symbionts, this study is the first comparative analysis of these symbiont genomes from four distinct Edessa stink bug species. Finally, we propose the candidate name "Candidatus Pantoea edessiphila" for the species of these symbionts with strain designations according to their host species.}, }
@article {pmid29420571, year = {2018}, author = {Sinnathamby, G and Henderson, G and Umair, S and Janssen, P and Bland, R and Simpson, H}, title = {The bacterial community associated with the sheep gastrointestinal nematode parasite Haemonchus contortus.}, journal = {PloS one}, volume = {13}, number = {2}, pages = {e0192164}, pmid = {29420571}, issn = {1932-6203}, mesh = {Animals ; Female ; Gastrointestinal Tract/microbiology/*parasitology ; Haemonchus/*isolation &amp; purification ; Intestinal Diseases, Parasitic/microbiology/parasitology/veterinary ; Lactococcus/genetics/isolation &amp; purification ; Microscopy, Electron, Transmission ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sheep/microbiology/*parasitology ; Sheep Diseases/microbiology/parasitology ; Streptococcus/genetics/isolation &amp; purification ; }, abstract = {Culture-independent methods were used to study the microbiota of adult worms, third-stage larvae and eggs, both in faeces and laid in vitro, of Haemonchus contortus, a nematode parasite of the abomasa of ruminants which is a major cause of production losses and ill-health. Bacteria were identified in eggs, the female reproductive tract and the gut of adult and third-stage larvae (L3). PCR amplification of 16S rRNA sequences, denaturing gradient gel electrophoresis (DGGE) and clone libraries were used to compare the composition of the microbial communities of the different life-cycle stages of the parasites, as well as parasites and their natural environments. The microbiomes of adult worms and L3 were different from those in the abomasum or faeces respectively. The H. contortus microbiota was mainly comprised of members of the phyla Proteobacteria, Firmicutes and Bacteroidetes. Bacteria were localised in the gut, inside eggs and within the uterus of adult female worms using the universal FISH Eub338 probe, which targets most bacteria, and were also seen in these tissues by light and transmission electron microscopy. Streptococcus/Lactococcus sp. were identified within the distal uterus with the probe Strc493. Sequences from the genera Weissella and Leuconostoc were found in all life-cycle stages, except eggs collected from faeces, in which most sequences belonged to Clostridium sp. Bacteria affiliated with Weissella/Leuconostoc were identified in both PCR-DGGE short sequences and clone libraries of nearly full length 16S rRNA bacterial sequences in all life-cycle stages and subsequently visualised in eggs by fluorescent in situ hybridisation (FISH) with group-specific probes. This strongly suggests they are vertically transmitted endosymbionts. As this study was carried out on a parasite strain which has been maintained in the laboratory, other field isolates will need to be examined to establish whether these bacteria are more widely dispersed and have potential as targets to control H. contortus infections.}, }
@article {pmid29415256, year = {2018}, author = {Senra, MVX and Sung, W and Ackerman, M and Miller, SF and Lynch, M and Soares, CAG}, title = {An Unbiased Genome-Wide View of the Mutation Rate and Spectrum of the Endosymbiotic Bacterium Teredinibacter turnerae.}, journal = {Genome biology and evolution}, volume = {10}, number = {3}, pages = {723-730}, pmid = {29415256}, issn = {1759-6653}, support = {R01 GM036827/GM/NIGMS NIH HHS/United States ; R35 GM122566/GM/NIGMS NIH HHS/United States ; }, mesh = {*Evolution, Molecular ; Gammaproteobacteria/*genetics ; Genetic Variation ; Genome, Bacterial ; Mutation ; Mutation Rate ; *Selection, Genetic ; Symbiosis/genetics ; }, abstract = {Mutations contribute to genetic variation in all living systems. Thus, precise estimates of mutation rates and spectra across a diversity of organisms are required for a full comprehension of evolution. Here, a mutation-accumulation (MA) assay was carried out on the endosymbiotic bacterium Teredinibacter turnerae. After ∼3,025 generations, base-pair substitutions (BPSs) and insertion-deletion (indel) events were characterized by whole-genome sequencing analysis of 47 independent MA lines, yielding a BPS rate of 1.14 × 10-9 per site per generation and indel rate of 1.55 × 10-10 events per site per generation, which are among the highest within free-living and facultative intracellular bacteria. As in other endosymbionts, a significant bias of BPSs toward A/T and an excess of deletion mutations over insertion mutations are observed for these MA lines. However, even with a deletion bias, the genome remains relatively large (∼5.2 Mb) for an endosymbiotic bacterium. The estimate of the effective population size (Ne) in T. turnerae is quite high and comparable to free-living bacteria (∼4.5 × 107), suggesting that the heavy bottlenecking associated with many endosymbiotic relationships is not prevalent during the life of this endosymbiont. The efficiency of selection scales with increasing Ne and such strong selection may have been operating against the deletion bias, preventing genome erosion. The observed mutation rate in this endosymbiont is of the same order of magnitude of those with similar Ne, consistent with the idea that population size is a primary determinant of mutation-rate evolution within endosymbionts, and that not all endosymbionts have low Ne.}, }
@article {pmid29411455, year = {2018}, author = {Ivens, ABF and Gadau, A and Kiers, ET and Kronauer, DJC}, title = {Can social partnerships influence the microbiome? Insights from ant farmers and their trophobiont mutualists.}, journal = {Molecular ecology}, volume = {27}, number = {8}, pages = {1898-1914}, pmid = {29411455}, issn = {1365-294X}, support = {335542/ERC_/European Research Council/International ; UL1 TR000043/TR/NCATS NIH HHS/United States ; }, mesh = {Acetobacteraceae/genetics/physiology ; Animals ; Ants/genetics/*microbiology ; Aphids/genetics/*microbiology ; Behavior, Animal ; Buchnera/genetics ; Microbiota/*genetics ; Phylogeny ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Mutualistic interactions with microbes have played a crucial role in the evolution and ecology of animal hosts. However, it is unclear what factors are most important in influencing particular host-microbe associations. While closely related animal species may have more similar microbiota than distantly related species due to phylogenetic contingencies, social partnerships with other organisms, such as those in which one animal farms another, may also influence an organism's symbiotic microbiome. We studied a mutualistic network of Brachymyrmex and Lasius ants farming several honeydew-producing Prociphilus aphids and Rhizoecus mealybugs to test whether the mutualistic microbiomes of these interacting insects are primarily correlated with their phylogeny or with their shared social partnerships. Our results confirm a phylogenetic signal in the microbiomes of aphid and mealybug trophobionts, with each species harbouring species-specific endosymbiont strains of Buchnera (aphids), Tremblaya and Sodalis (mealybugs), and Serratia (both mealybugs and aphids) despite being farmed by the same ants. This is likely explained by strict vertical transmission of trophobiont endosymbionts between generations. In contrast, our results show the ants' microbiome is possibly shaped by their social partnerships, with ants that farm the same trophobionts also sharing strains of sugar-processing Acetobacteraceae bacteria, known from other honeydew-feeding ants and which likely reside extracellularly in the ants' guts. These ant-microbe associations are arguably more "open" and subject to horizontal transmission or social transmission within ant colonies. These findings suggest that the role of social partnerships in shaping a host's symbiotic microbiome can be variable and is likely dependent on how the microbes are transmitted across generations.}, }
@article {pmid29393944, year = {2018}, author = {Mergaert, P}, title = {Role of antimicrobial peptides in controlling symbiotic bacterial populations.}, journal = {Natural product reports}, volume = {35}, number = {4}, pages = {336-356}, doi = {10.1039/c7np00056a}, pmid = {29393944}, issn = {1460-4752}, mesh = {Animals ; Antimicrobial Cationic Peptides/genetics/immunology/*metabolism ; Bacterial Proteins/genetics/immunology/*metabolism ; Gastrointestinal Microbiome ; Gene Expression Regulation, Bacterial ; Hydra/microbiology ; Immunity, Innate ; Insecta/microbiology ; Mammals/microbiology ; Rhizobium/metabolism ; Root Nodules, Plant/microbiology ; Symbiosis/*physiology ; }, abstract = {Covering: up to 2018 Antimicrobial peptides (AMPs) have been known for well over three decades as crucial mediators of the innate immune response in animals and plants, where they are involved in the killing of infecting microbes. However, AMPs have now also been found to be produced by eukaryotic hosts during symbiotic interactions with bacteria. These symbiotic AMPs target the symbionts and therefore have a more subtle biological role: not eliminating the microbial symbiont population but rather keeping it in check. The arsenal of AMPs and the symbionts' adaptations to resist them are in a careful balance, which contributes to the establishment of the host-microbe homeostasis. Although in many cases the biological roles of symbiotic AMPs remain elusive, for a number of symbiotic interactions, precise functions have been assigned or proposed to the AMPs, which are discussed here. The microbiota living on epithelia in animals, from the most primitive ones to the mammals, are challenged by a cocktail of AMPs that determine the specific composition of the bacterial community as well as its spatial organization. In the symbiosis of legume plants with nitrogen-fixing rhizobium bacteria, the host deploys an extremely large panel of AMPs - called nodule-specific cysteine-rich (NCR) peptides - that drive the bacteria into a terminally differentiated state and manipulate the symbiont physiology to maximize the benefit for the host. The NCR peptides are used as tools to enslave the bacterial symbionts, limiting their reproduction but keeping them metabolically active for nitrogen fixation. In the nutritional symbiotic interactions of insects and protists that have vertically transmitted bacterial symbionts with reduced genomes, symbiotic AMPs could facilitate the integration of the endosymbiont and host metabolism by favouring the flow of metabolites across the symbiont membrane through membrane permeabilization.}, }
@article {pmid29390142, year = {2018}, author = {Zélé, F and Santos, I and Olivieri, I and Weill, M and Duron, O and Magalhães, S}, title = {Endosymbiont diversity and prevalence in herbivorous spider mite populations in South-Western Europe.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {4}, pages = {}, doi = {10.1093/femsec/fiy015}, pmid = {29390142}, issn = {1574-6941}, mesh = {Animals ; Bacteroidetes/classification/genetics/*isolation &amp; purification ; Biological Evolution ; Europe ; Herbivory ; Microbiota/genetics ; Phylogeny ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/genetics/*isolation &amp; purification ; Symbiosis ; Tetranychidae/*microbiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Bacterial endosymbionts are known as important players of the evolutionary ecology of their hosts. However, their distribution, prevalence and diversity are still largely unexplored. To this aim, we investigated infections by the most common bacterial reproductive manipulators in herbivorous spider mites of South-Western Europe. Across 16 populations belonging to three Tetranychus species, Wolbachia was the most prevalent (ca. 61%), followed by Cardinium (12%-15%), while only few individuals were infected by Rickettsia (0.9%-3%), and none carried Arsenophonus or Spiroplasma. These endosymbionts are here reported for the first time in Tetranychus evansi and Tetranychus ludeni, and showed variable infection frequencies between and within species, with several cases of coinfections. Moreover, Cardinium was more prevalent in Wolbachia-infected individuals, which suggests facilitation between these symbionts. Finally, sequence comparisons revealed no variation of the Wolbachia wsp and Rickettsia gtlA genes, but some diversity of the Cardinium 16S rRNA, both between and within populations of the three mite species. Some of the Cardinium sequences identified belonged to distantly-related clades, and the lack of association between these sequences and spider mite mitotypes suggests repeated host switching of Cardinium. Overall, our results reveal a complex community of symbionts in this system, opening the path for future studies.}, }
@article {pmid29390087, year = {2018}, author = {Grosser, K and Ramasamy, P and Amirabad, AD and Schulz, MH and Gasparoni, G and Simon, M and Schrallhammer, M}, title = {More than the "Killer Trait": Infection with the Bacterial Endosymbiont Caedibacter taeniospiralis Causes Transcriptomic Modulation in Paramecium Host.}, journal = {Genome biology and evolution}, volume = {10}, number = {2}, pages = {646-656}, pmid = {29390087}, issn = {1759-6653}, mesh = {Gammaproteobacteria/*physiology ; Gene Expression Regulation ; Metabolic Networks and Pathways ; Paramecium/*genetics/*microbiology/physiology ; Phenotype ; Sequence Analysis, RNA ; *Symbiosis ; *Transcriptome ; }, abstract = {Endosymbiosis is a widespread phenomenon and hosts of bacterial endosymbionts can be found all-over the eukaryotic tree of life. Likely, this evolutionary success is connected to the altered phenotype arising from a symbiotic association. The potential variety of symbiont's contributions to new characteristics or abilities of host organisms are largely unstudied. Addressing this aspect, we focused on an obligate bacterial endosymbiont that confers an intraspecific killer phenotype to its host. The symbiosis between Paramecium tetraurelia and Caedibacter taeniospiralis, living in the host's cytoplasm, enables the infected paramecia to release Caedibacter symbionts, which can simultaneously produce a peculiar protein structure and a toxin. The ingestion of bacteria that harbor both components leads to the death of symbiont-free congeners. Thus, the symbiosis provides Caedibacter-infected cells a competitive advantage, the "killer trait." We characterized the adaptive gene expression patterns in symbiont-harboring Paramecium as a second symbiosis-derived aspect next to the killer phenotype. Comparative transcriptomics of infected P. tetraurelia and genetically identical symbiont-free cells confirmed altered gene expression in the symbiont-bearing line. Our results show up-regulation of specific metabolic and heat shock genes whereas down-regulated genes were involved in signaling pathways and cell cycle regulation. Functional analyses to validate the transcriptomics results demonstrated that the symbiont increases host density hence providing a fitness advantage. Comparative transcriptomics shows gene expression modulation of a ciliate caused by its bacterial endosymbiont thus revealing new adaptive advantages of the symbiosis. Caedibacter taeniospiralis apparently increases its host fitness via manipulation of metabolic pathways and cell cycle control.}, }
@article {pmid29387157, year = {2018}, author = {Käch, H and Mathé-Hubert, H and Dennis, AB and Vorburger, C}, title = {Rapid evolution of symbiont-mediated resistance compromises biological control of aphids by parasitoids.}, journal = {Evolutionary applications}, volume = {11}, number = {2}, pages = {220-230}, pmid = {29387157}, issn = {1752-4571}, abstract = {There is growing interest in biological control as a sustainable and environmentally friendly way to control pest insects. Aphids are among the most detrimental agricultural pests worldwide, and parasitoid wasps are frequently employed for their control. The use of asexual parasitoids may improve the effectiveness of biological control because only females kill hosts and because asexual populations have a higher growth rate than sexuals. However, asexuals may have a reduced capacity to track evolutionary change in their host populations. We used a factorial experiment to compare the ability of sexual and asexual populations of the parasitoid Lysiphlebus fabarum to control caged populations of black bean aphids (Aphis fabae) of high and low clonal diversity. The aphids came from a natural population, and one-third of the aphid clones harbored Hamiltonella defensa, a heritable bacterial endosymbiont that increases resistance to parasitoids. We followed aphid and parasitoid population dynamics for 3 months but found no evidence that the reproductive mode of parasitoids affected their effectiveness as biocontrol agents, independent of host clonal diversity. Parasitoids failed to control aphids in most cases, because their introduction resulted in strong selection for clones protected by H. defensa. The increasingly resistant aphid populations escaped control by parasitoids, and we even observed parasitoid extinctions in many cages. The rapid evolution of symbiont-conferred resistance in turn imposed selection on parasitoids. In cages where asexual parasitoids persisted until the end of the experiment, they became dominated by a single genotype able to overcome the protection provided by H. defensa. Thus, there was evidence for parasitoid counteradaptation, but it was generally too slow for parasitoids to regain control over aphid populations. It appears that when pest aphids possess defensive symbionts, the presence of parasitoid genotypes able to overcome symbiont-conferred resistance is more important for biocontrol success than their reproductive mode.}, }
@article {pmid29385445, year = {2018}, author = {Gerhart, JG and Auguste Dutcher, H and Brenner, AE and Moses, AS and Grubhoffer, L and Raghavan, R}, title = {Multiple Acquisitions of Pathogen-Derived Francisella Endosymbionts in Soft Ticks.}, journal = {Genome biology and evolution}, volume = {10}, number = {2}, pages = {607-615}, pmid = {29385445}, issn = {1759-6653}, mesh = {Animals ; Argasidae/*microbiology/physiology ; Biological Evolution ; Francisella/*genetics/isolation &amp; purification/*physiology ; Genes, Bacterial ; Gram-Negative Bacterial Infections/microbiology ; Humans ; Phylogeny ; *Symbiosis ; Virulence Factors/genetics ; }, abstract = {Bacterial endosymbionts of ticks are of interest due to their close evolutionary relationships with tick-vectored pathogens. For instance, whereas many ticks contain Francisella-like endosymbionts (FLEs), others transmit the mammalian pathogen Francisella tularensis. We recently sequenced the genome of an FLE present in the hard tick Amblyomma maculatum (FLE-Am) and showed that it likely evolved from a pathogenic ancestor. In order to expand our understanding of FLEs, in the current study we sequenced the genome of an FLE in the soft tick Ornithodoros moubata and compared it to the genomes of FLE-Am, Francisella persica-an FLE in the soft tick Argus (Persicargas) arboreus, Francisella sp. MA067296-a clinical isolate responsible for an opportunistic human infection, and F. tularensis, the established human pathogen. We determined that FLEs and MA067296 belonged to a sister taxon of mammalian pathogens, and contained inactivated versions of virulence genes present in F. tularensis, indicating that the most recent common ancestor shared by FLEs and F. tularensis was a potential mammalian pathogen. Our analyses also revealed that the two soft ticks (O. moubata and A. arboreus) probably acquired their FLEs separately, suggesting that the virulence attenuation observed in FLEs are not the consequence of a single acquisition event followed by speciation, but probably due to independent transitions of pathogenic francisellae into nonpathogenic FLEs within separate tick lineages. Additionally, we show that FLEs encode intact pathways for the production of several B vitamins and cofactors, denoting that they could function as nutrient-provisioning endosymbionts in ticks.}, }
@article {pmid29384253, year = {2018}, author = {Gao, J and Guo, H and Sun, Y and Ge, F}, title = {Differential accumulation of leucine and methionine in red and green pea aphids leads to different fecundity in response to nitrogen fertilization.}, journal = {Pest management science}, volume = {74}, number = {8}, pages = {1779-1789}, doi = {10.1002/ps.4875}, pmid = {29384253}, issn = {1526-4998}, mesh = {Animals ; Aphids/microbiology/*physiology ; Buchnera/*physiology ; Color ; Female ; Fertility ; Fertilizers/analysis ; Herbivory ; Leucine/biosynthesis/*metabolism ; Medicago truncatula/*chemistry ; Methionine/biosynthesis/*metabolism ; Nitrogen/metabolism/pharmacology ; Pigmentation/drug effects ; *Signal Transduction ; Symbiosis ; }, abstract = {BACKGROUND: Nitrogen fertilization affects plants directly and herbivorous insects indirectly. Although insect species and even genotypes are known to differ in their responses to nitrogen fertilization, the physiological and molecular mechanisms remain unclear. This study assessed the fecundity and related regulatory signaling pathways in the green and red morphs of pea aphid (Acyrthosiphon pisum) feeding on Medicago truncatula with and without nitrogen fertilization.<br><br>RESULTS: Nitrogen fertilization significantly increased foliar amino acid concentrations and consequently increased the concentrations of several individual essential amino acids in body tissue of the green morph. The increased concentration of Leu, Ile, Met and Val was consistent with enhanced biosynthesis of these amino acids in the endosymbiont Buchnera. Under nitrogen fertilization, Leu and Met accumulated in the green morph enhanced the target of rapamycin (TOR) signaling pathway, which consequently increased fecundity by promoting vitellogenin synthesis. In the red morph, however, nitrogen fertilization did not change the concentration of essential amino acids, TOR signaling or fecundity.<br><br>CONCLUSION: Specific amino acids accumulation and the nutrient transduction pathway in pea aphids are responsible for genotype-specific fecundity in response to nitrogen fertilization, which could be used as potential target for pest control. &#xa9; 2018 Society of Chemical Industry.}, }
@article {pmid29379215, year = {2018}, author = {Poole, P and Ramachandran, V and Terpolilli, J}, title = {Rhizobia: from saprophytes to endosymbionts.}, journal = {Nature reviews. Microbiology}, volume = {16}, number = {5}, pages = {291-303}, pmid = {29379215}, issn = {1740-1534}, support = {BB/F004753/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/F013159/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Fabaceae/*microbiology ; Nitrogen Fixation/physiology ; Plant Roots/microbiology ; Rhizobium/*physiology ; Symbiosis/*physiology ; }, abstract = {Rhizobia are some of the best-studied plant microbiota. These oligotrophic Alphaproteobacteria or Betaproteobacteria form symbioses with their legume hosts. Rhizobia must exist in soil and compete with other members of the microbiota before infecting legumes and forming N2-fixing bacteroids. These dramatic lifestyle and developmental changes are underpinned by large genomes and even more complex pan-genomes, which encompass the whole population and are subject to rapid genetic exchange. The ability to respond to plant signals and chemoattractants and to colonize nutrient-rich roots are crucial for the competitive success of these bacteria. The availability of a large body of genomic, physiological, biochemical and ecological studies makes rhizobia unique models for investigating community interactions and plant colonization.}, }
@article {pmid29377516, year = {2018}, author = {Siegmund, L and Schweikert, M and Fischer, MS and Wöstemeyer, J}, title = {Bacterial Surface Traits Influence Digestion by Tetrahymena pyriformis and Alter Opportunity to Escape from Food Vacuoles.}, journal = {The Journal of eukaryotic microbiology}, volume = {65}, number = {5}, pages = {600-611}, doi = {10.1111/jeu.12504}, pmid = {29377516}, issn = {1550-7408}, mesh = {Escherichia coli/*chemistry/ultrastructure ; Microscopy, Electron, Transmission ; Phagosomes/microbiology ; Surface Properties ; Symbiosis ; Tetrahymena pyriformis/microbiology/*physiology/ultrastructure ; Vacuoles/*microbiology/ultrastructure ; }, abstract = {Endosymbiotic interactions are frequently found in nature, especially in the group of protists. Even though many endosymbioses have been studied in detail, little is known about the mechanistic origins and physiological prerequisites of endosymbiont establishment. A logical step towards the development of endocytobiotic associations is evading digestion and escaping from the host's food vacuoles. Surface properties of bacteria are probably involved in these processes. Therefore, we chemically modified the surface of a transformant strain of Escherichia coli prior to feeding to Tetrahymena pyriformis. N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide allows any substance carrying amino- or carboxyl groups to be bound covalently to the bacterial surface by forming a peptide bond, thus, altering its properties biochemically and biophysically in a predictable manner. The effect of different traits on digestion of T. pyriformis was examined by fluorescence and transmission electron microscopy. The efficiency of digestion differs considerably depending on the coupled substances. Alkaline substances inhibit digestion partially, resulting in incomplete digestion and slightly enhanced escape rates. Increasing hydrophobicity leads to much higher escape frequencies. Both results point to possible mechanisms employed by pathogenic bacteria or potential endosymbionts in evading digestion and transmission to the host's cytoplasm.}, }
@article {pmid29375803, year = {2018}, author = {Thongsripong, P and Chandler, JA and Green, AB and Kittayapong, P and Wilcox, BA and Kapan, DD and Bennett, SN}, title = {Mosquito vector-associated microbiota: Metabarcoding bacteria and eukaryotic symbionts across habitat types in Thailand endemic for dengue and other arthropod-borne diseases.}, journal = {Ecology and evolution}, volume = {8}, number = {2}, pages = {1352-1368}, pmid = {29375803}, issn = {2045-7758}, support = {P20 RR018727/RR/NCRR NIH HHS/United States ; U54 AI065359/AI/NIAID NIH HHS/United States ; }, abstract = {Vector-borne diseases are a major health burden, yet factors affecting their spread are only partially understood. For example, microbial symbionts can impact mosquito reproduction, survival, and vectorial capacity, and hence affect disease transmission. Nonetheless, current knowledge of mosquito-associated microbial communities is limited. To characterize the bacterial and eukaryotic microbial communities of multiple vector species collected from different habitat types in disease endemic areas, we employed next-generation 454 pyrosequencing of 16S and 18S rRNA amplicon libraries, also known as metabarcoding. We investigated pooled whole adult mosquitoes of three medically important vectors, Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus, collected from different habitats across central Thailand where we previously characterized mosquito diversity. Our results indicate that diversity within the mosquito microbiota is low, with the majority of microbes assigned to one or a few taxa. Two of the most common eukaryotic and bacterial genera recovered (Ascogregarina and Wolbachia, respectively) are known mosquito endosymbionts with potentially parasitic and long evolutionary relationships with their hosts. Patterns of microbial composition and diversity appeared to differ by both vector species and habitat for a given species, although high variability between samples suggests a strong stochastic element to microbiota assembly. In general, our findings suggest that multiple factors, such as habitat condition and mosquito species identity, may influence overall microbial community composition, and thus provide a basis for further investigations into the interactions between vectors, their microbial communities, and human-impacted landscapes that may ultimately affect vector-borne disease risk.}, }
@article {pmid29374496, year = {2018}, author = {Reveillaud, J and Anderson, R and Reves-Sohn, S and Cavanaugh, C and Huber, JA}, title = {Metagenomic investigation of vestimentiferan tubeworm endosymbionts from Mid-Cayman Rise reveals new insights into metabolism and diversity.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {19}, pmid = {29374496}, issn = {2049-2618}, support = {grant NNX-32709AB75G/NASA/NASA/United States ; C-DEBI//National Science Foundation/International ; }, mesh = {Animals ; Autotrophic Processes ; Bacteria/*classification/genetics/isolation &amp; purification ; Genes, Bacterial ; Hydrothermal Vents ; Metagenomics/*methods ; Phylogeny ; Polychaeta/*microbiology ; RNA, Ribosomal, 16S/*genetics ; Symbiosis ; }, abstract = {BACKGROUND: The microbial endosymbionts of two species of vestimentiferan tubeworms (Escarpia sp. and Lamellibrachia sp.2) collected from an area of low-temperature hydrothermal diffuse vent flow at the Mid-Cayman Rise (MCR) in the Caribbean Sea were characterized using microscopy, phylogenetic analyses, and a metagenomic approach.<br><br>RESULTS: Bacteria, with a typical Gram negative cell envelope contained within membrane-bound vacuoles, were observed within the trophosome of both tubeworm species. Phylogenetic analysis of the 16S rRNA gene and ITS region suggested MCR individuals harbored highly similar endosymbionts that were >&#x2009;98% identical, with the exception of two symbionts that showed a 60&#xa0;bp insertion within the ITS region. All sequences from MCR endosymbionts formed a separate well-supported clade that diverged from those of symbionts of seep and vent vestimentiferans from the Pacific, Gulf of Mexico, and Mediterranean Sea. The metagenomes of the symbionts of two specimens of each tubeworm species were sequenced, and two distinct Gammaproteobacteria metagenome-assembled genomes (MAGs) of more than 4 Mbp assembled. An Average Nucleotide Identity (ANI) of 86.5% between these MAGs, together with distinct 16S rRNA gene and ITS sequences, indicate the presence of multiple endosymbiont phylotypes at the MCR, with one MAG shared between one Escarpia and two Lamellibrachia individuals, indicating these endosymbionts are not specific to either host species. Genes for sulfur and hydrogen oxidation, nitrate reduction (assimilatory and dissimilatory), glycolysis and the Krebs cycle, peptide, sugar, and lipid transporters, and both rTCA and CBB carbon fixation cycles were detected in the MAGs, highlighting key and shared functions with symbiont metagenomes of the vestimentiferans Riftia, Tevnia, and Ridgeia from the Pacific. The potential for a second hydrogen oxidation pathway (via a bidirectional hydrogenase), formate dehydrogenase, a catalase, and several additional peptide transporters were found exclusively in the MCR endosymbiont MAGs.<br><br>CONCLUSIONS: The present study adds new evidence that tubeworm endosymbionts can potentially switch from autotrophic to heterotrophic metabolism, or may be mixotrophic, presumably while free-living, and also suggests their versatile metabolic potential may enable both the host and symbionts to exploit a wide range of environmental conditions. Together, the marked gene content and sequence dissimilarity at the rRNA operon and whole genome level between vent and seep symbionts suggest these newly described endosymbionts from the MCR belong to a novel tubeworm endosymbiont genera, introduced as Candidatus Vondammii.}, }
@article {pmid29367840, year = {2018}, author = {Ghosh, S and Bouvaine, S and Richardson, SCW and Ghanim, M and Maruthi, MN}, title = {Fitness costs associated with infections of secondary endosymbionts in the cassava whitefly species Bemisia tabaci.}, journal = {Journal of pest science}, volume = {91}, number = {1}, pages = {17-28}, pmid = {29367840}, issn = {1612-4758}, abstract = {We investigated the dual effects of bacterial infections and diseased cassava plants on the fitness and biology of the Bemisia tabaci infesting cassava in Africa. Isofemale B. tabaci colonies of sub-Saharan Africa 1-subgroup 3 (SSA1-SG3), infected with two secondary endosymbiotic bacteria Arsenophonus and Rickettsia (AR+) and those free of AR infections (AR-), were compared for fitness parameters on healthy and East African cassava mosaic virus-Uganda variant (EACMV-UG)-infected cassava plants. The whitefly fecundity and nymph development was not affected by bacterial infections or the infection of cassava by the virus. However, emergence of adults from nymphs was 50 and 17% higher by AR- on healthy and virus-infected plants, respectively, than AR+ flies. Development time of adults also was 10 days longer in AR+ than AR-. The whiteflies were further compared for acquisition and retention of EACMV-UG. Higher proportion of AR- acquired (91.8%) and retained (87.6%) the virus than AR+ (71.8, 61.2%, respectively). Similarly, the AR- flies retained higher quantities of virus (~ninefold more) than AR+. These results indicated that bacteria-free whiteflies were superior and better transmitters of EACMV-UG, as they had higher adult emergence, quicker life cycle and better virus retention abilities than those infected with bacteria.}, }
@article {pmid29367472, year = {2018}, author = {Noda, S and Shimizu, D and Yuki, M and Kitade, O and Ohkuma, M}, title = {Host-Symbiont Cospeciation of Termite-Gut Cellulolytic Protists of the Genera Teranympha and Eucomonympha and their Treponema Endosymbionts.}, journal = {Microbes and environments}, volume = {33}, number = {1}, pages = {26-33}, pmid = {29367472}, issn = {1347-4405}, mesh = {Animals ; DNA, Bacterial/genetics ; Evolution, Molecular ; *Gastrointestinal Microbiome ; Isoptera/genetics/*microbiology ; Parabasalidea/genetics/*physiology ; Phylogeny ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; *Symbiosis ; Treponema/genetics/*physiology ; }, abstract = {Cellulolytic flagellated protists inhabit the hindgut of termites. They are unique and essential to termites and related wood-feeding cockroaches, enabling host feeding on cellulosic matter. Protists of two genera in the family Teranymphidae (phylum Parabasalia), Eucomonympha and Teranympha, are phylogenetically closely related and harbor intracellular endosymbiotic bacteria from the genus Treponema. In order to obtain a clearer understanding of the evolutionary history of this triplex symbiotic relationship, the molecular phylogenies of the three symbiotic partners, the Teranymphidae protists, their Treponema endosymbionts, and their host termites, were inferred and compared. Strong congruence was observed in the tree topologies of all interacting partners, implying their cospeciating relationships. In contrast, the coevolutionary relationship between the Eucomonympha protists and their endosymbionts was more complex, and evidence of incongruence against cospeciating relationships suggested frequent host switches of the endosymbionts, possibly because multiple Eucomonympha species are present in the same gut community. Similarities in the 16S rRNA and gyrB gene sequences of the endosymbionts were higher among Teranympha spp. (>99.25% and >97.2%, respectively), whereas those between Teranympha and Eucomonympha were lower (<97.1% and <91.9%, respectively). In addition, the endosymbionts of Teranympha spp. formed a phylogenetic clade distinct from those of Eucomonympha spp. Therefore, the endosymbiont species of Teranympha spp., designated here as "Candidatus Treponema teratonymphae", needs to be classified as a species distinct from the endosymbiont species of Eucomonympha spp.}, }
@article {pmid29364862, year = {2018}, author = {Sánchez-Cañizares, C and Jorrín, B and Durán, D and Nadendla, S and Albareda, M and Rubio-Sanz, L and Lanza, M and González-Guerrero, M and Prieto, RI and Brito, B and Giglio, MG and Rey, L and Ruiz-Argüeso, T and Palacios, JM and Imperial, J}, title = {Genomic Diversity in the Endosymbiotic Bacterium Rhizobium leguminosarum.}, journal = {Genes}, volume = {9}, number = {2}, pages = {}, pmid = {29364862}, issn = {2073-4425}, support = {R01 GM080227/GM/NIGMS NIH HHS/United States ; }, abstract = {Rhizobium leguminosarum bv. viciae is a soil α-proteobacterium that establishes a diazotrophic symbiosis with different legumes of the Fabeae tribe. The number of genome sequences from rhizobial strains available in public databases is constantly increasing, although complete, fully annotated genome structures from rhizobial genomes are scarce. In this work, we report and analyse the complete genome of R. leguminosarum bv. viciae UPM791. Whole genome sequencing can provide new insights into the genetic features contributing to symbiotically relevant processes such as bacterial adaptation to the rhizosphere, mechanisms for efficient competition with other bacteria, and the ability to establish a complex signalling dialogue with legumes, to enter the root without triggering plant defenses, and, ultimately, to fix nitrogen within the host. Comparison of the complete genome sequences of two strains of R. leguminosarum bv. viciae, 3841 and UPM791, highlights the existence of different symbiotic plasmids and a common core chromosome. Specific genomic traits, such as plasmid content or a distinctive regulation, define differential physiological capabilities of these endosymbionts. Among them, strain UPM791 presents unique adaptations for recycling the hydrogen generated in the nitrogen fixation process.}, }
@article {pmid29362506, year = {2018}, author = {Chong, RA and Moran, NA}, title = {Evolutionary loss and replacement of Buchnera, the obligate endosymbiont of aphids.}, journal = {The ISME journal}, volume = {12}, number = {3}, pages = {898-908}, pmid = {29362506}, issn = {1751-7370}, mesh = {Animals ; Aphids/*microbiology ; *Biological Evolution ; Buchnera/*genetics ; DNA, Bacterial/genetics ; Gammaproteobacteria/*genetics/metabolism ; Genetic Drift ; Insecta ; Metabolic Networks and Pathways/genetics ; RNA, Ribosomal, 16S/analysis ; Symbiosis/*genetics ; }, abstract = {Symbiotic interactions between organisms create new ecological niches. For example, many insects survive on plant-sap with the aid of maternally transmitted bacterial symbionts that provision essential nutrients lacking in this diet. Symbiotic partners often enter a long-term relationship in which the co-evolutionary fate of lineages is interdependent. Obligate symbionts that are strictly maternally transmitted experience genetic drift and genome degradation, compromising symbiont function and reducing host fitness unless hosts can compensate for these deficits. One evolutionary solution is the acquisition of a novel symbiont with a functionally intact genome. Whereas almost all aphids host the anciently acquired bacterial endosymbiont Buchnera aphidicola (Gammaproteobacteria), Geopemphigus species have lost Buchnera and instead contain a maternally transmitted symbiont closely related to several known insect symbionts from the bacterial phylum Bacteroidetes. A complete genome sequence shows the symbiont has lost many ancestral genes, resulting in a genome size intermediate between that of free-living and symbiotic Bacteroidetes. The Geopemphigus symbiont retains biosynthetic pathways for amino acids and vitamins, as in Buchnera and other insect symbionts. This case of evolutionary replacement of Buchnera provides an opportunity to further understand the evolution and functional genomics of symbiosis.}, }
@article {pmid29357812, year = {2018}, author = {Xie, W and Yang, X and Chen, C and Yang, Z and Guo, L and Wang, D and Huang, J and Zhang, H and Wen, Y and Zhao, J and Wu, Q and Wang, S and Coates, BS and Zhou, X and Zhang, Y}, title = {The invasive MED/Q Bemisia tabaci genome: a tale of gene loss and gene gain.}, journal = {BMC genomics}, volume = {19}, number = {1}, pages = {68}, pmid = {29357812}, issn = {1471-2164}, mesh = {Animals ; Crops, Agricultural/parasitology ; Cytochrome P-450 Enzyme System/genetics ; *Genome, Insect ; Glucuronosyltransferase/genetics ; Hemiptera/*classification/*genetics ; Host Specificity ; Insect Proteins/*genetics ; *Insecticide Resistance ; Multigene Family ; Phylogeny ; Symbiosis ; Transcriptome ; }, abstract = {BACKGROUND: Sweetpotato whitefly, Bemisia tabaci MED/Q and MEAM1/B, are two economically important invasive species that cause considerable damages to agriculture crops through direct feeding and indirect vectoring of plant pathogens. Recently, a draft genome of B. tabaci MED/Q has been assembled. In this study, we focus on the genomic comparison between MED/Q and MEAM1/B, with a special interest in MED/Q's genomic signatures that may contribute to the highly invasive nature of this emerging insect pest.<br><br>RESULTS: The genomes of both species share similarity in syntenic blocks, but have significant divergence in the gene coding sequence. Expansion of cytochrome P450 monooxygenases and UDP glycosyltransferases in MED/Q and MEAM1/B genome is functionally validated for mediating insecticide resistance in MED/Q using in vivo RNAi. The amino acid biosynthesis pathways in MED/Q genome are partitioned among the host and endosymbiont genomes in a manner distinct from other hemipterans. Evidence of horizontal gene transfer to the host genome may explain their obligate relationship. Putative loss-of-function in the immune deficiency-signaling pathway due to the gene loss is a shared ancestral trait among hemipteran insects.<br><br>CONCLUSIONS: The expansion of detoxification genes families, such as P450s, may contribute to the development of insecticide resistance traits and a broad host range in MED/Q and MEAM1/B, and facilitate species' invasions into intensively managed cropping systems. Numerical and compositional changes in multiple gene families (gene loss and gene gain) in the MED/Q genome sets a foundation for future hypothesis testing that will advance our understanding of adaptation, viral transmission, symbiosis, and plant-insect-pathogen tritrophic interactions.}, }
@article {pmid29354098, year = {2017}, author = {Tikhe, CV and Husseneder, C}, title = {Metavirome Sequencing of the Termite Gut Reveals the Presence of an Unexplored Bacteriophage Community.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {2548}, pmid = {29354098}, issn = {1664-302X}, abstract = {The Formosan subterranean termite; Coptotermes formosanus is nutritionally dependent on the complex and diverse community of bacteria and protozoa in their gut. Although, there have been many studies to decipher the taxonomic and functional diversity of bacterial communities in the guts of termites, their bacteriophages remain unstudied. We sequenced the metavirome of the guts of Formosan subterranean termite workers to study the diversity of bacteriophages and other associated viruses. Results showed that the termites harbor a virome in their gut comprised of varied and previously unknown bacteriophages. Between 87-90% of the predicted dsDNA virus genes by Metavir showed similarity to the tailed bacteriophages (Caudovirales). Many predicted genes from the virome matched to bacterial prophage regions. These data are suggestive of a virome dominated by temperate bacteriophages. We predicted the genomes of seven novel Caudovirales bacteriophages from the termite gut. Three of these predicted bacteriophage genomes were found in high proportions in all the three termite colonies tested. Two bacteriophages are predicted to infect endosymbiotic bacteria of the gut protozoa. The presence of these putative bacteriophages infecting endosymbionts of the gut protozoa, suggests a quadripartite relationship between the termites their symbiotic protozoa, endosymbiotic bacteria of the protozoa and their bacteriophages. Other than Caudovirales, ss-DNA virus related genes were also present in the termite gut. We predicted the genomes of 12 novel Microviridae phages from the termite gut and seven of those possibly represent a new proposed subfamily. Circovirus like genomes were also assembled from the termite gut at lower relative abundance. We predicted 10 novel circovirus genomes in this study. Whether these circoviruses infect the termites remains elusive at the moment. The functional and taxonomical annotations suggest that the termites may harbor a core virome comprised of the bacteriophages infecting endosymbionts of the gut protozoa.}, }
@article {pmid29351633, year = {2018}, author = {Lindsey, ARI and Rice, DW and Bordenstein, SR and Brooks, AW and Bordenstein, SR and Newton, ILG}, title = {Evolutionary Genetics of Cytoplasmic Incompatibility Genes cifA and cifB in Prophage WO of Wolbachia.}, journal = {Genome biology and evolution}, volume = {10}, number = {2}, pages = {434-451}, pmid = {29351633}, issn = {1759-6653}, support = {P30 DK058404/DK/NIDDK NIH HHS/United States ; R01 AI132581/AI/NIAID NIH HHS/United States ; R21 HD086833/HD/NICHD NIH HHS/United States ; T32 GM080178/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Arthropods/*microbiology/physiology ; Evolution, Molecular ; *Genes, Viral ; Male ; Prophages/*genetics ; Reproduction ; Symbiosis ; Transcriptome ; Wolbachia/genetics/physiology/*virology ; }, abstract = {The bacterial endosymbiont Wolbachia manipulates arthropod reproduction to facilitate its maternal spread through host populations. The most common manipulation is cytoplasmic incompatibility (CI): Wolbachia-infected males produce modified sperm that cause embryonic mortality, unless rescued by embryos harboring the same Wolbachia. The genes underlying CI, cifA and cifB, were recently identified in the eukaryotic association module of Wolbachia's prophage WO. Here, we use transcriptomic and genomic approaches to address three important evolutionary facets of the cif genes. First, we assess whether or not cifA and cifB comprise a classic toxin-antitoxin operon in wMel and show that the two genes exhibit striking, transcriptional differences across host development. They can produce a bicistronic message despite a predicted hairpin termination element in their intergenic region. Second, cifA and cifB strongly coevolve across the diversity of phage WO. Third, we provide new domain and functional predictions across homologs within Wolbachia, and show that amino acid sequences vary substantially across the genus. Finally, we investigate conservation of cifA and cifB and find frequent degradation and loss of the genes in strains that no longer induce CI. Taken together, we demonstrate that cifA and cifB exhibit complex transcriptional regulation in wMel, provide functional annotations that broaden the potential mechanisms of CI induction, and report recurrent erosion of cifA and cifB in non-CI strains, thus expanding our understanding of the most widespread form of reproductive parasitism.}, }
@article {pmid29348333, year = {2018}, author = {Zaburannyi, N and Grosser, K and Gasparoni, G and Müller, R and Schrallhammer, M and Simon, M}, title = {Draft Genome Sequence and Annotation of the Obligate Bacterial Endosymbiont Caedibacter taeniospiralis, Causative Agent of the Killer Phenotype in Paramecium tetraurelia.}, journal = {Genome announcements}, volume = {6}, number = {3}, pages = {}, pmid = {29348333}, issn = {2169-8287}, abstract = {Caedibacter taeniospiralis is an obligate endosymbiont living in the cytoplasm of Paramecium tetraureliaC. taeniospiralis causes the so-called killer trait, eliminating intraspecific competitors of its host when released into the medium by the concerted action of the unusual protein structure R-body (refractile body) in addition to an as-yet-unknown toxin.}, }
@article {pmid29346623, year = {2018}, author = {Fakhour, S and Ambroise, J and Renoz, F and Foray, V and Gala, JL and Hance, T}, title = {A large-scale field study of bacterial communities in cereal aphid populations across Morocco.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {3}, pages = {}, doi = {10.1093/femsec/fiy003}, pmid = {29346623}, issn = {1574-6941}, mesh = {Animals ; Aphids/classification/*microbiology/physiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Biological Evolution ; Edible Grain/parasitology ; Host Specificity ; *Microbiota ; Morocco ; Symbiosis ; }, abstract = {Insects are frequently associated with bacteria that can have significant ecological and evolutionary impacts on their hosts. To date, few studies have examined the influence of environmental factors to microbiome composition of aphids. The current work assessed the diversity of bacterial communities of five cereal aphid species (Sitobion avenae, Rhopalosiphum padi, R. maidis, Sipha maydis and Diuraphis noxia) collected across Morocco, covering a wide range of environmental conditions. We aimed to test whether symbiont combinations are host or environment specific. Deep 16S rRNA sequencing enabled us to identify 17 bacterial operational taxonomic units (OTUs). The obligate symbiont Buchnera aphidicola was represented by five OTUs with multiple haplotypes in many single samples. Facultative endosymbionts were presented by a high prevalence of Regiella insecticola and Serratia symbiotica in S. avenae and Si. maydis, respectively. In addition to these symbiotic partners, Pseudomonas, Acinetobacter, Pantoea, Erwinia and Staphyloccocus were also identified in aphids, suggesting that the aphid microbiome is not limited to the presence of endosymbiotic bacteria. Beside a significant association between host species and bacterial communities, an inverse correlation was also found between altitude and α-diversity. Overall, our results support that symbiont combinations are mainly host specific.}, }
@article {pmid29346449, year = {2018}, author = {Chrostek, E and Teixeira, L}, title = {Within host selection for faster replicating bacterial symbionts.}, journal = {PloS one}, volume = {13}, number = {1}, pages = {e0191530}, pmid = {29346449}, issn = {1932-6203}, mesh = {Animals ; Drosophila melanogaster/*microbiology ; Genes, Bacterial ; *Host-Pathogen Interactions ; *Symbiosis ; Virulence/genetics ; Wolbachia/genetics/*growth &amp; development/pathogenicity ; }, abstract = {Wolbachia is a widespread, intracellular symbiont of arthropods, able to induce reproductive distortions and antiviral protection in insects. Wolbachia can also be pathogenic, as is the case with wMelPop, a virulent variant of the endosymbiont of Drosophila melanogaster. An extensive genomic amplification of the 20kb region encompassing eight Wolbachia genes, called Octomom, is responsible for wMelPop virulence. The Octomom copy number in wMelPop can be highly variable between individual D. melanogaster flies, even when comparing siblings arising from a single female. Moreover, Octomom copy number can change rapidly between generations. These data suggest an intra-host variability in Octomom copy number between Wolbachia cells. Since wMelPop Wolbachia with different Octomom copy numbers grow at different rates, we hypothesized that selection could act on this intra-host variability. Here we tested if total Octomom copy number changes during the lifespan of individual Drosophila hosts, revealing selection for different Wolbachia populations. We performed a time course analysis of Octomom amplification in flies whose mothers were controlled for Octomom copy number. We show that despite the Octomom copy number being relatively stable it increases slightly throughout D. melanogaster adult life. This indicates that there is selection acting on the intra-host variation in the Octomom copy number over the lifespan of individual hosts. This within host selection for faster replicating bacterial symbionts may be in conflict with between host selection against highly pathogenic Wolbachia.}, }
@article {pmid29342876, year = {2018}, author = {Zhang, Q and Gao, X and Ren, Y and Ding, X and Qiu, J and Li, N and Zeng, F and Chu, Z}, title = {Improvement of Verticillium Wilt Resistance by Applying Arbuscular Mycorrhizal Fungi to a Cotton Variety with High Symbiotic Efficiency under Field Conditions.}, journal = {International journal of molecular sciences}, volume = {19}, number = {1}, pages = {}, pmid = {29342876}, issn = {1422-0067}, mesh = {Antifungal Agents/metabolism ; *Disease Resistance/genetics ; Gene Expression Regulation, Plant ; Genes, Plant ; Gossypium/genetics/growth &amp; development/*immunology/*microbiology ; Mycorrhizae/*physiology ; Plant Diseases/genetics/*immunology/*microbiology ; *Symbiosis ; Verticillium/*physiology ; }, abstract = {Arbuscular mycorrhizal fungi (AMF) play an important role in nutrient cycling processes and plant stress resistance. To evaluate the effect of Rhizophagus irregularis CD1 on plant growth promotion (PGP) and Verticillium wilt disease, the symbiotic efficiency of AMF (SEA) was first investigated over a range of 3% to 94% in 17 cotton varieties. The high-SEA subgroup had significant PGP effects in a greenhouse. From these results, the highest-SEA variety of Lumian 1 was selected for a two-year field assay. Consistent with the performance from the greenhouse, the AMF-mediated PGP of Lumian 1 also produced significant results, including an increased plant height, stem diameter, number of petioles, and phosphorus content. Compared with the mock treatment, AMF colonization obviously inhibited the symptom development of Verticillium dahliae and more strongly elevated the expression of pathogenesis-related genes and lignin synthesis-related genes. These results suggest that AMF colonization could lead to the mycorrhiza-induced resistance (MIR) of Lumian 1 to V. dahliae. Interestingly, our results indicated that the AMF endosymbiont could directly inhibit the growth of phytopathogenic fungi including V. dahliae by releasing undefined volatiles. In summary, our results suggest that stronger effects of AMF application result from the high-SEA.}, }
@article {pmid29338021, year = {2018}, author = {Grottoli, AG and Dalcin Martins, P and Wilkins, MJ and Johnston, MD and Warner, ME and Cai, WJ and Melman, TF and Hoadley, KD and Pettay, DT and Levas, S and Schoepf, V}, title = {Coral physiology and microbiome dynamics under combined warming and ocean acidification.}, journal = {PloS one}, volume = {13}, number = {1}, pages = {e0191156}, pmid = {29338021}, issn = {1932-6203}, mesh = {Acids/*chemistry ; Animals ; Anthozoa/*physiology ; *Global Warming ; *Hydrogen-Ion Concentration ; *Microbiota ; *Oceans and Seas ; Seawater ; Species Specificity ; }, abstract = {Rising seawater temperature and ocean acidification threaten the survival of coral reefs. The relationship between coral physiology and its microbiome may reveal why some corals are more resilient to these global change conditions. Here, we conducted the first experiment to simultaneously investigate changes in the coral microbiome and coral physiology in response to the dual stress of elevated seawater temperature and ocean acidification expected by the end of this century. Two species of corals, Acropora millepora containing the thermally sensitive endosymbiont C21a and Turbinaria reniformis containing the thermally tolerant endosymbiont Symbiodinium trenchi, were exposed to control (26.5°C and pCO2 of 364 μatm) and treatment (29.0°C and pCO2 of 750 μatm) conditions for 24 days, after which we measured the microbial community composition. These microbial findings were interpreted within the context of previously published physiological measurements from the exact same corals in this study (calcification, organic carbon flux, ratio of photosynthesis to respiration, photosystem II maximal efficiency, total lipids, soluble animal protein, soluble animal carbohydrates, soluble algal protein, soluble algal carbohydrate, biomass, endosymbiotic algal density, and chlorophyll a). Overall, dually stressed A. millepora had reduced microbial diversity, experienced large changes in microbial community composition, and experienced dramatic physiological declines in calcification, photosystem II maximal efficiency, and algal carbohydrates. In contrast, the dually stressed coral T. reniformis experienced a stable and more diverse microbiome community with minimal physiological decline, coupled with very high total energy reserves and particulate organic carbon release rates. Thus, the microbiome changed and microbial diversity decreased in the physiologically sensitive coral with the thermally sensitive endosymbiotic algae but not in the physiologically tolerant coral with the thermally tolerant endosymbiont. Our results confirm recent findings that temperature-stress tolerant corals have a more stable microbiome, and demonstrate for the first time that this is also the case under the dual stresses of ocean warming and acidification. We propose that coral with a stable microbiome are also more physiologically resilient and thus more likely to persist in the future, and shape the coral species diversity of future reef ecosystems.}, }
@article {pmid29334340, year = {2019}, author = {Amala, M and Rajamanikandan, S and Prabhu, D and Surekha, K and Jeyakanthan, J}, title = {Identification of anti-filarial leads against aspartate semialdehyde dehydrogenase of Wolbachia endosymbiont of Brugia malayi: combined molecular docking and molecular dynamics approaches.}, journal = {Journal of biomolecular structure &amp; dynamics}, volume = {37}, number = {2}, pages = {394-410}, doi = {10.1080/07391102.2018.1427633}, pmid = {29334340}, issn = {1538-0254}, mesh = {Amino Acid Sequence ; Animals ; Anthelmintics/*chemistry/pharmacology ; Aspartate-Semialdehyde Dehydrogenase/antagonists &amp; inhibitors/*chemistry ; Binding Sites ; Brugia malayi/*enzymology ; Catalytic Domain ; Chemical Phenomena ; Drug Discovery/methods ; Enzyme Inhibitors/*chemistry/pharmacology ; Humans ; Hydrogen Bonding ; Hydrophobic and Hydrophilic Interactions ; *Molecular Docking Simulation ; *Molecular Dynamics Simulation ; Protein Binding ; }, abstract = {Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents. In this present study, molecular modeling combined with molecular dynamics simulations and structure-based virtual screening were performed to identify potent lead molecules against ASDase. Based on Glide score, toxicity profile, binding affinity and mode of interactions with the ASDase, five potent lead molecules were selected. The molecular docking and dynamics results revealed that the amino acid residues Arg103, Asn133, Cys134, Gln161, Ser164, Lys218, Arg239, His246, and Asn321 plays a crucial role in effective binding of Top leads into the active site of ASDase. The stability of the ASDase-lead complexes was confirmed by running the 30 ns molecular dynamics simulations. The pharmacokinetic properties of the identified lead molecules are in the acceptable range. Furthermore, density functional theory and binding free energy calculations were performed to rank the lead molecules. Thus, the identified lead molecules can be used for the development of anti-filarial agents to combat the pathogenecity of Brugia malayi.}, }
@article {pmid29333583, year = {2018}, author = {Vecchi, M and Newton, ILG and Cesari, M and Rebecchi, L and Guidetti, R}, title = {The Microbial Community of Tardigrades: Environmental Influence and Species Specificity of Microbiome Structure and Composition.}, journal = {Microbial ecology}, volume = {76}, number = {2}, pages = {467-481}, pmid = {29333583}, issn = {1432-184X}, mesh = {Animals ; Bacteria/*classification/genetics ; Bacterial Physiological Phenomena ; Bacteroidetes/classification/genetics ; Biodiversity ; DNA, Bacterial/genetics ; Host Microbial Interactions ; Microbiota/genetics/*physiology ; *Phylogeny ; Proteobacteria/classification/genetics ; RNA, Ribosomal, 16S/genetics ; Rickettsiales/classification/genetics ; Species Specificity ; *Symbiosis ; Tardigrada/*microbiology ; }, abstract = {Symbiotic associations of metazoans with bacteria strongly influence animal biology since bacteria are ubiquitous and virtually no animal is completely free from them. Tardigrades are micrometazoans famous for their ability to undergo ametabolic states (cryptobiosis) but very little information is available on potential microbial associations. We characterized the microbiomes of six limnoterrestrial tardigrade species belonging to several phylogenetic lines in tandem with the microbiomes of their respective substrates. The experimental design enabled us to determine the effects of both the environment and the host genetic background on the tardigrade microbiome; we were able to define the microbial community of the same species sampled from different environments, and the communities of different species from the same environment. Our 16S rRNA gene amplicon approach indicated that the tardigrade microbiome is species-specific and well differentiated from the environment. Tardigrade species showed a much lower microbial diversity compared to their substrates, with only one significant exception. Forty-nine common OTUs (operational taxonomic units) were classified into six bacterial phyla, while four common OTUs were unclassified and probably represent novel bacterial taxa. Specifically, the tardigrade microbiome appears dominated by Proteobacteria and Bacteroidetes. Some OTUs were shared between different species from geographically distant samples, suggesting the associated bacteria may be widespread. Putative endosymbionts of tardigrades from the order Rickettsiales were identified. Our results indicated that like all other animals, tardigrades have their own microbiota that is different among species, and its assembly is determined by host genotype and environmental influences.}, }
@article {pmid29330535, year = {2018}, author = {Tanaka, Y and Suzuki, A and Sakai, K}, title = {The stoichiometry of coral-dinoflagellate symbiosis: carbon and nitrogen cycles are balanced in the recycling and double translocation system.}, journal = {The ISME journal}, volume = {12}, number = {3}, pages = {860-868}, pmid = {29330535}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*metabolism ; Autotrophic Processes/physiology ; Carbon/*metabolism ; *Coral Reefs ; Dinoflagellida/*metabolism ; Microalgae/metabolism ; Nitrogen/metabolism ; Nitrogen Cycle/*physiology ; Symbiosis/*physiology ; }, abstract = {Symbioses between microalgae and animal hosts have the advantage of acquiring and sharing autotrophically produced organic carbon (C) as their energy source. However, the stoichiometry and turnover rates of biological elements in symbioses are not fully understood because of complicated metabolic interactions. We report the first comprehensive and simultaneous measurement of C and nitrogen (N) flows through coral-dinoflagellate symbiosis by using the unique approach of dual-isotope labeling with [13]C and [15]N, in situ chasing, and isotope-mixing models. The coral autotrophy occurred with much lower C:N ratios than previously thought, and the autotrophically produced N-rich organic matter was efficiently transferred to the animal host through two different pathways. In contrast to the dynamic N cycles within the symbiosis, the N uptake from the ambient seawater was extremely limited, which enabled the coral symbiosis to sustain N with a long turnover time (1 year). These findings suggest that coral endosymbionts are not under N limitation but are actively producing organic N and driving microscale N cycles in the reef ecosystem. The present techniques could be applied to further quantify the C and N cycles in other symbiotic interactions and reveal their ecological advantages.}, }
@article {pmid29330187, year = {2018}, author = {Bergin, C and Wentrup, C and Brewig, N and Blazejak, A and Erséus, C and Giere, O and Schmid, M and De Wit, P and Dubilier, N}, title = {Acquisition of a Novel Sulfur-Oxidizing Symbiont in the Gutless Marine Worm Inanidrilus exumae.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {7}, pages = {}, pmid = {29330187}, issn = {1098-5336}, mesh = {Animals ; Chromatiaceae/classification/genetics/*physiology ; Genes, Bacterial ; In Situ Hybridization, Fluorescence ; Oligochaeta/*microbiology ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Sequence Analysis, RNA ; *Symbiosis ; }, abstract = {Gutless phallodrilines are marine annelid worms without a mouth or gut, which live in an obligate association with multiple bacterial endosymbionts that supply them with nutrition. In this study, we discovered an unusual symbiont community in the gutless phallodriline Inanidrilus exumae that differs markedly from the microbiomes of all 22 of the other host species examined. Comparative 16S rRNA gene sequence analysis and fluorescence in situ hybridization revealed that I. exumae harbors cooccurring gamma-, alpha-, and deltaproteobacterial symbionts, while all other known host species harbor gamma- and either alpha- or deltaproteobacterial symbionts. Surprisingly, the primary chemoautotrophic sulfur oxidizer "Candidatus Thiosymbion" that occurs in all other gutless phallodriline hosts does not appear to be present in I. exumae Instead, I. exumae harbors a bacterial endosymbiont that resembles "Ca Thiosymbion" morphologically and metabolically but originates from a novel lineage within the class Gammaproteobacteria This endosymbiont, named Gamma 4 symbiont here, had a 16S rRNA gene sequence that differed by at least 7% from those of other free-living and symbiotic bacteria and by 10% from that of "Ca Thiosymbion." Sulfur globules in the Gamma 4 symbiont cells, as well as the presence of genes characteristic for autotrophy (cbbL) and sulfur oxidation (aprA), indicate that this symbiont is a chemoautotrophic sulfur oxidizer. Our results suggest that a novel lineage of free-living bacteria was able to establish a stable and specific association with I. exumae and appears to have displaced the "Ca Thiosymbion" symbionts originally associated with these hosts.IMPORTANCE All 22 gutless marine phallodriline species examined to date live in a highly specific association with endosymbiotic, chemoautotrophic sulfur oxidizers called "Ca Thiosymbion." These symbionts evolved from a single common ancestor and represent the ancestral trait for this host group. They are transmitted vertically and assumed to be in transition to becoming obligate endosymbionts. It is therefore surprising that despite this ancient, evolutionary relationship between phallodriline hosts and "Ca Thiosymbion," these symbionts are apparently no longer present in Inanidrilus exumae They appear to have been displaced by a novel lineage of sulfur-oxidizing bacteria only very distantly related to "Ca Thiosymbion." Thus, this study highlights the remarkable plasticity of both animals and bacteria in establishing beneficial associations: the phallodriline hosts were able to acquire and maintain symbionts from two very different lineages of bacteria, while sulfur-oxidizing bacteria from two very distantly related lineages were able to independently establish symbiotic relationships with phallodriline hosts.}, }
@article {pmid29330177, year = {2018}, author = {Zhu, YX and Song, YL and Zhang, YK and Hoffmann, AA and Zhou, JC and Sun, JT and Hong, XY}, title = {Incidence of Facultative Bacterial Endosymbionts in Spider Mites Associated with Local Environments and Host Plants.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {6}, pages = {}, pmid = {29330177}, issn = {1098-5336}, mesh = {Animals ; Bacteroidetes/*physiology ; China ; Environment ; Lycopersicon esculentum/growth &amp; development ; Soybeans/growth &amp; development ; Spiroplasma/*physiology ; *Symbiosis ; Tetranychidae/*microbiology/physiology ; Wolbachia/*physiology ; Zea mays/growth &amp; development ; }, abstract = {Spider mites are frequently associated with multiple endosymbionts whose infection patterns often exhibit spatial and temporal variation. However, the association between endosymbiont prevalence and environmental factors remains unclear. Here, we surveyed endosymbionts in natural populations of the spider mite, Tetranychus truncatus, in China, screening 935 spider mites from 21 localities and 12 host plant species. Three facultative endosymbiont lineages, Wolbachia, Cardinium, and Spiroplasma, were detected at different infection frequencies (52.5%, 26.3%, and 8.6%, respectively). Multiple endosymbiont infections were observed in most local populations, and the incidence of individuals with the Wolbachia-Spiroplasma coinfection was higher than expected from the frequency of each infection within a population. Endosymbiont infection frequencies exhibited associations with environmental factors: Wolbachia infection rates increased at localities with higher annual mean temperatures, while Cardinium and Spiroplasma infection rates increased at localities from higher altitudes. Wolbachia was more common in mites from Lycopersicon esculentum and Glycine max compared to those from Zea mays This study highlights that host-endosymbiont interactions may be associated with environmental factors, including climate and other geographically linked factors, as well as the host's food plant.IMPORTANCE The aim of this study was to examine the incidence of endosymbiont distribution and the infection patterns in spider mites. The main findings are that multiple endosymbiont infections were more common than expected and that endosymbiont infection frequencies were associated with environmental factors. This work highlights that host-endosymbiont interactions need to be studied within an environmental and geographic context.}, }
@article {pmid29327963, year = {2017}, author = {Flanders, AJ and Rosenberg, JF and Bercier, M and Leissinger, MK and Black, LJ and Giglio, RF and Craft, SLM and Zoll, WM and Childress, AL and Wellehan, JFX}, title = {Antemortem Diagnosis of Coxiellosis in a Blue and Gold Macaw (Ara ararauna).}, journal = {Journal of avian medicine and surgery}, volume = {31}, number = {4}, pages = {364-372}, doi = {10.1647/2016-224}, pmid = {29327963}, issn = {1082-6742}, mesh = {Animals ; Bird Diseases/diagnosis/*microbiology ; Coxiella/classification/*isolation &amp; purification ; Fatal Outcome ; Female ; Gram-Negative Bacterial Infections/diagnosis/microbiology/*veterinary ; *Parrots ; }, abstract = {A 15-year-old female blue and gold macaw (Ara ararauna) was presented for evaluation after being found laterally recumbent, reluctant to move, and lethargic. Results of a complete blood count showed an increased number of immature heterophils with increased cytoplasmic basophilia and degranulation and the presence of a left shift. Radiographs and a computed tomography scan were performed and revealed a markedly enlarged spleen. An ultrasound-guided fine-needle aspirate of the spleen was submitted for cytologic examination and aerobic bacterial culture. While the culture revealed no growth, cytologic examination identified mononuclear phagocytes with cytoplasmic vacuoles containing structures consistent with bacteria. Pan-bacterial 16S rRNA polymerase chain reaction of the splenic sample followed by direct sequencing identified a Coxiella-like agent identical to one previously isolated in the liver of a golden-mantled rosella (Platycercus eximius). Phylogenetic analysis shows that avian coxiellosis agents and Coxiella burnetii, the agent of Q fever, represent 2 independent events of development of vertebrate pathogenicity in this group of tick endosymbionts. This report suggests diagnostic and treatment directions for coxiellosis in avian patients and indicates where further study is needed.}, }
@article {pmid29325007, year = {2018}, author = {Rosas, T and García-Ferris, C and Domínguez-Santos, R and Llop, P and Latorre, A and Moya, A}, title = {Rifampicin treatment of Blattella germanica evidences a fecal transmission route of their gut microbiota.}, journal = {FEMS microbiology ecology}, volume = {94}, number = {2}, pages = {}, doi = {10.1093/femsec/fiy002}, pmid = {29325007}, issn = {1574-6941}, mesh = {Adult ; Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Typing Techniques ; Blattellidae/*microbiology ; Feces/microbiology ; Flavobacteriaceae/*drug effects/*isolation &amp; purification ; Gastrointestinal Microbiome/*drug effects ; Humans ; Male ; Phylogeny ; Rifampin/*pharmacology ; Symbiosis ; }, abstract = {Eukaryotes have established symbiotic relationship with microorganisms, which enables them to accomplish functions that they cannot perform alone. In the German cockroach, Blattella germanica, the obligate endosymbiont Blattabacterium coexists with a rich gut microbiota. The transmission of Blattabacterium is vertical, but little is known about how the gut microbiota colonizes newborn individuals. In this study, we treated B. germanica populations with rifampicin, a broad-spectrum antibiotic, during two generations and analyzed gut bacterial composition and the Blattabacterium load in control and rifampicin-treated populations. Rifampicin exerted a drastic effect on gut microbiota composition, which recovered in the second generation in the case where the antibiotic was not added to the diet. Furthermore, we observed that bacterial species present in the diet, and particularly in the feces, contribute significantly to establishing the gut microbiota. Finally, the Blattabacterium population remained unaffected by the antibiotic treatment of adults during the first generation but was strongly reduced in the second generation, suggesting that this intracellular symbiont is sensitive to rifampicin only during the infection of the mature oocytes, when it is in an extracellular stage.}, }
@article {pmid29317310, year = {2018}, author = {Maita, C and Matsushita, M and Miyoshi, M and Okubo, T and Nakamura, S and Matsuo, J and Takemura, M and Miyake, M and Nagai, H and Yamaguchi, H}, title = {Amoebal endosymbiont Neochlamydia protects host amoebae against Legionella pneumophila infection by preventing Legionella entry.}, journal = {Microbes and infection}, volume = {20}, number = {4}, pages = {236-244}, doi = {10.1016/j.micinf.2017.12.012}, pmid = {29317310}, issn = {1769-714X}, mesh = {Acanthamoeba/cytology/metabolism/*microbiology ; Actins/metabolism ; Chlamydiales/*physiology ; Legionella/*physiology ; Phagocytosis ; *Symbiosis ; }, abstract = {Acanthamoeba isolated from environmental soil harbors the obligate intracellular symbiont Neochlamydia, which has a critical role in host amoebal defense against Legionella pneumophila infection. Here, by using morphological analysis with confocal laser scanning fluorescence microscopy and transmission electron microscopy, proteome analyses with two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and liquid chromatography-mass spectrometry (LC/MS), and transcriptome analysis with DNA microarray, we explored the mechanism by which the Neochlamydia affected this defense. We observed that when rare uptake did occur, the symbiotic amoebae allowed Legionella to grow normally. However, the symbiotic amoebae had severely reduced uptake of Legionella when compared with the aposymbiotic amoebae. Also, in contrast to amoebae carrying the endosymbiont, the actin cytoskeleton was significantly disrupted by Legionella infection in aposymbiotic amoebae. Furthermore, despite Legionella exposure, there was little change in Neochlamydia gene expression. Taken together, we concluded that the endosymbiont, Neochlamydia prevents Legionella entry to the host amoeba, resulting in the host defense against Legionella infection.}, }
@article {pmid29311247, year = {2018}, author = {Mann, M and Fattah-Hosseini, S and Ammar, ED and Stange, R and Warrick, E and Sturgeon, K and Shatters, R and Heck, M}, title = {Diaphorina citri Nymphs Are Resistant to Morphological Changes Induced by "Candidatus Liberibacter asiaticus" in Midgut Epithelial Cells.}, journal = {Infection and immunity}, volume = {86}, number = {4}, pages = {}, pmid = {29311247}, issn = {1098-5522}, mesh = {Animals ; Epithelial Cells/*microbiology ; Female ; Gastrointestinal Microbiome ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Male ; Microscopy, Confocal ; Nymph/*microbiology ; Oxidative Stress ; Phenotype ; Rhizobiaceae/*physiology ; }, abstract = {"Candidatus Liberibacter asiaticus" is the causative bacterium associated with citrus greening disease. "Ca Liberibacter asiaticus" is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri insects reared on healthy or "Ca Liberibacter asiaticus"-infected citrus trees using quantitative PCR, confocal microscopy, and mitochondrial superoxide staining for evidence of oxidative stress. Consistent with its classification as propagative, "Ca Liberibacter asiaticus" titers were higher in adults than in nymphs. Our previous work showed that adult D. citri insects have basal levels of karyorrhexis (fragmentation of the nucleus) in midgut epithelial cells, which is increased in severity and frequency in response to "Ca Liberibacter asiaticus." Here, we show that nymphs exhibit lower levels of early-stage karyorrhexis than adults and are refractory to the induction of advanced karyorrhexis by "Ca Liberibacter asiaticus" in the midgut epithelium. MitoSox Red staining showed that guts of infected adults, particularly males, experienced oxidative stress in response to "Ca Liberibacter asiaticus." A positive correlation between the titers of "Ca Liberibacter asiaticus" and the Wolbachia endosymbiont was observed in adult and nymph midguts, suggesting an interplay between these bacteria during development. We hypothesize that the resistance of the nymph midgut to late-stage karyorrhexis through as yet unknown molecular mechanisms benefits "Ca Liberibacter asiaticus" for efficient invasion of midgut epithelial cells, which may be a factor explaining the developmental dependency of "Ca Liberibacter asiaticus" acquisition by the vector.}, }
@article {pmid29310713, year = {2018}, author = {Maire, J and Vincent-Monégat, C and Masson, F and Zaidman-Rémy, A and Heddi, A}, title = {An IMD-like pathway mediates both endosymbiont control and host immunity in the cereal weevil Sitophilus spp.}, journal = {Microbiome}, volume = {6}, number = {1}, pages = {6}, pmid = {29310713}, issn = {2049-2618}, support = {ANR-13-BSV7-0016-01//ANR/International ; }, mesh = {Animals ; Antimicrobial Cationic Peptides/*metabolism ; Bacterial Proteins/metabolism ; Cytotoxins/adverse effects ; Edible Grain/*parasitology ; Enterobacteriaceae/*metabolism ; Gene Expression Regulation ; Host Specificity ; Host-Pathogen Interactions ; Immunity, Innate ; Insect Proteins/*genetics/metabolism ; Symbiosis ; Transcription Factors/genetics/metabolism ; Weevils/*genetics/immunology/microbiology ; }, abstract = {Many insects developing on nutritionally unbalanced diets have evolved symbiotic associations with vertically transmitted intracellular bacteria (endosymbionts) that provide them with metabolic components, thereby improving the host's abilities to thrive on such poor ecological niches. While host-endosymbiont coevolutionary constraints are known to entail massive genomic changes in the microbial partner, host's genomic evolution remains elusive, particularly with regard to the immune system. In the cereal weevil Sitophilus spp., which houses Sodalis pierantonius, endosymbionts are secluded in specialized host cells, the bacteriocytes that group together as an organ, the bacteriome. We previously reported that at standard conditions, the bacteriome highly expresses the coleoptericin A (colA) antimicrobial peptide (AMP), which was shown to prevent endosymbiont escape from the bacteriocytes. However, following the insect systemic infection by pathogens, the bacteriome upregulates a cocktail of AMP encoding genes, including colA. The regulations that allow these contrasted immune responses remain unknown. In this short report, we provide evidence that an IMD-like pathway is conserved in two sibling species of cereal weevils, Sitophilus oryzae and Sitophilus zeamais. RNA interference (RNAi) experiments showed that imd and relish genes are essential for (i) colA expression in the bacteriome under standard conditions, (ii) AMP up-regulation in the bacteriome following a systemic immune challenge, and (iii) AMP systemic induction following an immune challenge. Histological analyses also showed that relish inhibition by RNAi resulted in endosymbiont escape from the bacteriome, strengthening the involvement of an IMD-like pathway in endosymbiont control. We conclude that Sitophilus' IMD-like pathway mediates both the bacteriome immune program involved in endosymbiont seclusion within the bacteriocytes and the systemic and local immune responses to exogenous challenges. This work provides a striking example of how a conserved immune pathway, initially described as essential in pathogen clearance, also functions in the control of mutualistic associations.}, }
@article {pmid29304142, year = {2018}, author = {Kamennaya, NA and Kennaway, G and Fuchs, BM and Zubkov, MV}, title = {"Pomacytosis"-Semi-extracellular phagocytosis of cyanobacteria by the smallest marine algae.}, journal = {PLoS biology}, volume = {16}, number = {1}, pages = {e2003502}, pmid = {29304142}, issn = {1545-7885}, mesh = {Aquatic Organisms/physiology ; Cell Membrane ; Cell Nucleus ; Chloroplasts ; Cyanobacteria/*metabolism/*physiology ; Mitochondria ; Phagocytosis/*physiology ; Prochlorococcus/physiology ; }, abstract = {The smallest algae, less than 3 μm in diameter, are the most abundant eukaryotes of the World Ocean. Their feeding on planktonic bacteria of similar size is globally important but physically enigmatic. Tiny algal cells tightly packed with the voluminous chloroplasts, nucleus, and mitochondria appear to have insufficient organelle-free space for prey internalization. Here, we present the first direct observations of how the 1.3-μm algae, which are only 1.6 times bigger in diameter than their prey, hold individual Prochlorococcus cells in their open hemispheric cytostomes. We explain this semi-extracellular phagocytosis by the cell size limitation of the predatory alga, identified as the Braarudosphaera haptophyte with a nitrogen (N2)-fixing endosymbiont. Because the observed semi-extracellular phagocytosis differs from all other types of protistan phagocytosis, we propose to name it "pomacytosis" (from the Greek πώμα for "plug").}, }
@article {pmid29301977, year = {2018}, author = {Dunning Hotopp, JC and Klasson, L}, title = {The Complexities and Nuances of Analyzing the Genome of Drosophila ananassae and Its Wolbachia Endosymbiont.}, journal = {G3 (Bethesda, Md.)}, volume = {8}, number = {1}, pages = {373-374}, pmid = {29301977}, issn = {2160-1836}, support = {R01 CA206188/CA/NCI NIH HHS/United States ; }, mesh = {Animals ; Drosophila/genetics ; Drosophila melanogaster ; Genome ; Retroelements ; Wolbachia/*genetics ; }, abstract = {In "Retrotransposons Are the Major Contributors to the Expansion of the Drosophila ananassae Muller F Element," Leung et al. (2017) improved contigs attributed to the Muller F element from the original CAF1 assembly, and used them to conclude that most of the sequence expansion of the fourth chromosome of D. ananassae is due to a higher transposon load than previously thought, but is not due to Wolbachia DNA integrations. While we do not disagree with the first conclusion, the authors base their second conclusion on the lack of homology detected between their improved CAF1 genome assembly attributed to D. ananassae and reference Wolbachia genomes. While the consensus CAF1 genome assembly lacks any sequence similarity to the reference genome of the Wolbachia endosymbiont of Drosophila melanogaster (wMel), numerous studies from multiple laboratories provide experimental support for a large lateral/horizontal gene transfer (LGT) of a Wolbachia genome into this D. ananassae line. As such, we strongly suspect that the original whole genome assembly was either constructed after the removal of all Wolbachia reads, or that Wolbachia sequences were directly removed from the contigs in the CAF1 assembly. Hence, Leung et al. (2017) could not have identified the Wolbachia LGT using the CAF1 assembly. This manuscript by Leung et al. (2017) highlights that an assembly of the Wolbachia sequence reads and their mate pairs was erroneously attributed solely to the Wolbachia endosymbiont, albeit before we understood the extent of LGT in D. ananassae As such, we recommend that the sequences deposited at the National Center for Biotechnology Information (NCBI) under PRJNA13365 should not be attributed to Wolbachia endosymbiont of D. ananassae, but should have their taxonomy reclassified by NCBI as "Unclassified sequences." As our knowledge about genome biology improves, we need to reconsider and reanalyze earlier genomes removing the prejudice introduced from now defunct paradigms.}, }
@article {pmid29290582, year = {2018}, author = {Stańczak, J and Biernat, B and Racewicz, M and Zalewska, M and Matyjasek, A}, title = {Prevalence of different Rickettsia spp. in Ixodes ricinus and Dermacentor reticulatus ticks (Acari: Ixodidae) in north-eastern Poland.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {2}, pages = {427-434}, doi = {10.1016/j.ttbdis.2017.12.010}, pmid = {29290582}, issn = {1877-9603}, mesh = {Animals ; Dermacentor/growth &amp; development/*microbiology ; Female ; Ixodes/growth &amp; development/*microbiology ; Male ; Nymph/growth &amp; development/microbiology ; Phylogeny ; Poland ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Rickettsia/*isolation &amp; purification ; }, abstract = {In two surveys conducted in April and May 2013, a total of 1148 unfed ticks belonging to two species, Ixodes ricinus and Dermacentor reticulatus, were collected by flagging lower vegetation in 15 different localities throughout the Białowieża Primeval Forest (Podlaskie voivodship; north-eastern Poland) and in its buffer zone. In order to establish their infection rate with Rickettsia spp. individual adult ticks and pooled nymphs were tested by real-time PCR targeting the gltA gene. For the further identification of rickettsial species, positive samples were subjected for nested and semi-nested PCR targeting ompA and 16S rRNA genes, respectively, followed by sequencing analysis. Rickettsial DNA was detected in at least 279 ticks (minimum infection rate [MIR], 23.9%), including 52 nymphal and adult I. ricinus (MIR 8.6%) and 222 adult D. reticulatus (41%). Three species of SFG rickettsiae were identified: Rickettsia helvetica and 'Candidatus R. mendelii' in I. ricinus and R. raoultii in D. reticulatus and I. ricinus. Moreover, unidentified Rickettsia spp. which showed 99.4% identity, among others, with the uncultured Rickettsia sp. isolated from Cicadella viridis leafhopper, Rickettsia endosymbiont of Lasioglossum semilucens bee and R. bellii, were detected in I. ricinus, while Rickettsia sp. 98.3-98.4% homologous to Rickettsia secondary endosymbionts of Curculio spp. weevils was found in D. reticulatus. These results confirm the diversity of rickettsiae occurring in Poland. Further studies are needed to expand the knowledge on the species spectrum, prevalence and epidemiology of SFG rickettsiae in the country.}, }
@article {pmid31089666, year = {2018}, author = {Cazzolla Gatti, R}, title = {endogenosymbiosis: from hypothesis to empirical evidence towards a Unified Symbiogenetic Theory (UST).}, journal = {Theoretical biology forum}, volume = {111}, number = {1-2}, pages = {13-26}, doi = {10.19272/201811402002}, pmid = {31089666}, issn = {2282-2593}, mesh = {*Biological Evolution ; *Eukaryota ; Eukaryotic Cells ; Phylogeny ; Plastids ; *Symbiosis ; }, abstract = {In 1967 Lynn (Sagan) Margulis proposed that mitochondria, photosynthetic plastids and cilia were acquired prokaryotes and evolved symbiotically to form anaerobic bacteria, photosynthetic bacteria and eventually algae. Although most of this theory is well-accepted now, the hypothesis that endosymbiotic spirochaetes developed into eukaryotic flagella and cilia, and the following proposals of an endosymbiotic origin of other eukaryotic organelles such as peroxisomes, glyoxysomes, etc. have not received much acceptance, since evidence suggests they lack a genome and do not show ultrastructural similarities to bacteria or archaea. Nevertheless, the idea that over millennia mitochondria, plastids, prokaryotic and eukaryotic cells and even flagella and peroxisomes, as either primary or secondary endosymbionts, transferred some or all of their own DNA to the host cell’s nucleus through a process called «endogenosymbiosis» (i.e. a symbiotic gene transfer, such as the internalisation of the endosymbiont’s DNA with lateral transfer) has been recently suggested. This endogenosymbiosis could take place during the evolutionary transition from the symbiotic interacting community, invoked by Margulis, to a fully-integrated (either prokaryotic or eukaryotic) cell. This process could explain the missing evidence of the presence of DNA in flagella and peroxisomes whose ancestor endosymbionts, during the long endogenosymbiotic evolution, could have transferred their whole genome to the host cell that subsequently integrated it in its own genome, directly controlling its expression. Furthermore, the endogenosymbiosis hypothesis could be the explanation of the transition between an RNA to a DNA world and of some cases of true sympatric evolution of species, apparently inexplicable by the canonical speciation processes. Here, after an introduction to the theoretical basis of endogenosymbiosis and a discussion of the empirical confirming evidence, I show a graphical summary of the integration between this and the former endosymbiosis theories. The Serial Endosymbiosis Theory and the Secondary Endosymbiosis are merged with the Endogenosymbiosis Theory in a Unified Symbiogenetic Theory (UST).}, }
@article {pmid29290035, year = {2018}, author = {Angelella, G and Nalam, V and Nachappa, P and White, J and Kaplan, I}, title = {Endosymbionts Differentially Alter Exploratory Probing Behavior of a Nonpersistent Plant Virus Vector.}, journal = {Microbial ecology}, volume = {76}, number = {2}, pages = {453-458}, pmid = {29290035}, issn = {1432-184X}, mesh = {Animals ; Aphids/*microbiology/physiology ; Bacteriophages ; Enterobacteriaceae/physiology/*virology ; Host-Pathogen Interactions ; Insect Vectors/physiology/*virology ; Medicago sativa/virology ; Plant Diseases/virology ; Plant Viruses/pathogenicity/*physiology ; Potyvirus/pathogenicity/physiology ; Robinia/virology ; *Symbiosis ; }, abstract = {Insect endosymbionts (hereafter, symbionts) can modify plant virus epidemiology by changing the physiology or behavior of vectors, but their role in nonpersistent virus pathosystems remains uninvestigated. Unlike propagative and circulative viruses, nonpersistent plant virus transmission occurs via transient contamination of mouthparts, making direct interaction between symbiont and virus unlikely. Nonpersistent virus transmission occurs during exploratory intracellular punctures with styletiform mouthparts when vectors assess potential host-plant quality prior to phloem feeding. Therefore, we used an electrical penetration graph (EPG) to evaluate plant probing of the cowpea aphid, Aphis craccivora Koch, an important vector of cucurbit viruses, in the presence and absence of two facultative, intracellular symbionts. We tested four isolines of A. craccivora: two isolines were from a clone from black locust (Robinia pseudoacacia L.), one infected with Arsenophonus sp. and one cured, and two derived from a clone from alfalfa (Medicago sativa L.), one infected with Hamiltonella defensa and one cured. We quantified exploratory intracellular punctures, indicated by a waveform potential drop recorded by the EPG, initiation speed and frequency within the initial 15 min on healthy and watermelon mosaic virus-infected pumpkins. Symbiont associations differentially modified exploratory intracellular puncture frequency by aphids, with H. defensa-infected aphids exhibiting depressed probing, and Arsenophonus-infected aphids an increased frequency of probing. Further, there was greater overall aphid probing on virus-infected plants, suggesting that viruses manipulate their vectors to enhance acquisition-transmission rates, independent of symbiont infection. These results suggest facultative symbionts differentially affect plant-host exploration behaviors and potentially nonpersistent virus transmission by vectors.}, }
@article {pmid29287245, year = {2018}, author = {Sabaneyeva, E and Castelli, M and Szokoli, F and Benken, K and Lebedeva, N and Salvetti, A and Schweikert, M and Fokin, S and Petroni, G}, title = {Host and symbiont intraspecific variability: The case of Paramecium calkinsi and "Candidatus Trichorickettsia mobilis".}, journal = {European journal of protistology}, volume = {62}, number = {}, pages = {79-94}, doi = {10.1016/j.ejop.2017.12.002}, pmid = {29287245}, issn = {1618-0429}, mesh = {Alphaproteobacteria/*physiology ; *Host-Parasite Interactions ; Paramecium/*microbiology ; }, abstract = {Newly isolated strains of the ciliate Paramecium calkinsi and their cytoplasmic bacterial endosymbionts were characterized by a multidisciplinary approach, including live observation, ultrastructural investigation, and molecular analysis. Despite morphological resemblance, the characterized P. calkinsi strains showed a significant molecular divergence compared to conspecifics, possibly hinting for a cryptic speciation. The endosymbionts were clearly found to be affiliated to the species "Candidatus Trichorickettsia mobilis" (Rickettsiales, Rickettsiaceae), currently encompassing only bacteria retrieved in an obligate intracellular association with other ciliates. However, a relatively high degree of intraspecific divergence was observed as well, thus it was possible to split "Candidatus Trichorickettsia" into three subspecies, one of which represented so far only by the newly characterized endosymbionts of P. calkinsi. Other features distinguished the members of each different subspecies. In particular, the endosymbionts of P. calkinsi resided in the cytoplasm and possessed numerous peritrichous flagella, although no motility was evidenced, whereas their conspecifics in other hosts were either cytoplasmic and devoid of flagella, or macronuclear, displaying flagellar-driven motility. Moreover, contrarily to previously analyzed "Candidatus Trichorickettsia" hosts, infected P. calkinsi cells frequently became amicronucleate and demonstrated abnormal cell division, eventually leading to decline of the laboratory culture.}, }
@article {pmid29286204, year = {2019}, author = {Chu, CC and Hoffmann, M and Braswell, WE and Pelz-Stelinski, KS}, title = {Genetic variation and potential coinfection of Wolbachia among widespread Asian citrus psyllid (Diaphorina citri Kuwayama) populations.}, journal = {Insect science}, volume = {26}, number = {4}, pages = {671-682}, pmid = {29286204}, issn = {1744-7917}, mesh = {Animals ; Coinfection ; Genes, Bacterial ; Genes, Insect ; Genes, Mitochondrial ; Genetic Variation ; Geography ; Hemiptera/*microbiology ; Wolbachia/*genetics ; }, abstract = {Wolbachia can profoundly influence the survival, reproduction, and defenses of insect hosts. These interactions could potentially be harnessed for managing pests or insect-transmitted diseases. Diaphorina citri Kuwayama is a phloem-feeding pest capable of transmitting the putative causal agent of citrus greening, Candidatus Liberibacter asiaticus (CLas). Like many insects, D. citri is also infected with Wolbachia (wDi). Recent studies indicate that the relative abundance of wDi could be associated with the abundance of CLas, and that wDi may contribute to regulating expression of phage lytic cycle genes in CLas, suggesting the need for better understanding of wDi biology in general. This study investigated the genetic diversity of wDi among D. citri in populations spanning eleven countries and two U.S. territories. Six Wolbachia genes, wsp, coxA, fbpA, ftsZ, gatB, and hcpA, were sequenced and compared across samples. Two prevalent wDi strains were identified across the samples, and screening of clone libraries revealed possible coinfection of wDi strains in specific populations. D. citri mitochondrial cytochrome oxidase subunit I gene (mtCOI) were more divergent between D. citri populations that were infected with different wDi strains or had different infection statuses (single infection vs. coinfection). While we could not eliminate the possibility that maternal transmission may contribute to such patterns, it is also possible that wDi may induce cytoplasmic incompatibility in their host. These findings should contribute to the understanding of wDi population ecology, which may facilitate manipulation of this endosymbiont for management of citrus greening disease worldwide.}, }
@article {pmid29284564, year = {2018}, author = {Bodnar, JL and Fitch, S and Rosati, A and Zhong, J}, title = {The folA gene from the Rickettsia endosymbiont of Ixodes pacificus encodes a functional dihydrofolate reductase enzyme.}, journal = {Ticks and tick-borne diseases}, volume = {9}, number = {3}, pages = {443-449}, pmid = {29284564}, issn = {1877-9603}, support = {R15 AI099902/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/*genetics ; Biosynthetic Pathways/genetics ; Computational Biology ; Escherichia coli/genetics ; Ixodes/*microbiology ; Polymerase Chain Reaction ; Recombinant Proteins/genetics ; Rickettsia/*genetics ; Symbiosis ; Tetrahydrofolate Dehydrogenase/*genetics ; }, abstract = {Although nonpathogenic bacterial endosymbionts have been shown to contribute to their arthropod host's fitness by supplying them with essential vitamins and amino acids, little is known about the nutritional basis for the symbiotic relationship of endosymbionts in ticks. Our lab has previously reported that Rickettsia species phylotype G021 in Ixodes pacificus carries all five genes for de novo folate synthesis, and that these genes are monophyletic with homologs from other Rickettsia species. In this study, the rickettsial folate synthesis folA gene, coding for dihydrofolate reductase, was PCR amplified, cloned into an expression vector, and overexpressed in E. coli. Bioinformatic analysis identified that the FolA protein of phylotype G021 has the conserved DHFR domain, NADP binding sites, and substrate binding sites of bacterial dihydrofolate reductase. SDS-PAGE results showed that recombinant rickettsial FolA protein was overexpressed in BL21(DE3) E. coli in its soluble form. Affinity chromatography was used to purify the protein, and in vitro enzyme assays were performed to assess the biochemical activity of dihydrofolate reductase. The specific activity of recombinant FolA from phylotype G021 was determined to be 16.1 U/mg. This study has revealed that Rickettsia species phylotype G021 of I. pacificus is capable of producing a functional enzyme of the folate biosynthesis pathway, addressing the nutritional interactions behind the symbiosis between Rickettsia species phylotype G021 and its host.}, }
@article {pmid29281973, year = {2017}, author = {Chong, RA and Mueller, RL}, title = {Polymorphic duplicate genes and persistent non-coding sequences reveal heterogeneous patterns of mitochondrial DNA loss in salamanders.}, journal = {BMC genomics}, volume = {18}, number = {1}, pages = {992}, pmid = {29281973}, issn = {1471-2164}, support = {1210900//Division of Environmental Biology/International ; 1021489//Division of Environmental Biology/International ; }, mesh = {Animals ; Cell Nucleus/genetics ; DNA, Intergenic/chemistry ; DNA, Mitochondrial/*chemistry ; *Evolution, Molecular ; Gene Duplication ; *Gene Order ; *Genes, Duplicate ; *Genes, Mitochondrial ; Genes, rRNA ; Genetic Variation ; Mitochondrial Proteins/genetics ; Phylogeny ; RNA, Transfer/genetics ; Urodela/classification/*genetics ; }, abstract = {BACKGROUND: Mitochondria are the site of the citric acid cycle and oxidative phosphorylation (OXPHOS). In metazoans, the mitochondrial genome is a small, circular molecule averaging 16.5 kb in length. Despite evolutionarily conserved gene content, metazoan mitochondrial genomes show a diversity of gene orders most commonly explained by the duplication-random loss (DRL) model. In the DRL model, (1) a sequence of genes is duplicated in tandem, (2) one paralog sustains a loss-of-function mutation, resulting in selection to retain the other copy, and (3) the non-functional paralog is eventually deleted from the genome. Despite its apparent role in generating mitochondrial gene order diversity, little is known about the tempo and mode of random gene loss after duplication events. Here, we determine mitochondrial gene order across the salamander genus Aneides, which was previously shown to include at least two DRL-mediated rearrangement events. We then analyze these gene orders in a phylogenetic context to reveal patterns of DNA loss after mitochondrial gene duplication.<br><br>RESULTS: We identified two separate duplication events that resulted in mitochondrial gene rearrangements in Aneides; one occurred at the base of the clade tens of millions of years ago, while the other occurred much more recently (i.e. within a single species), resulting in gene order polymorphism and paralogs that are readily identifiable. We demonstrate that near-complete removal of duplicate rRNA genes has occurred since the recent duplication event, whereas duplicate protein-coding genes persist as pseudogenes and duplicate tRNAs persist as functionally intact paralogs. In addition, we show that non-coding DNA duplicated at the base of the clade has persisted across species for tens of millions of years.<br><br>CONCLUSIONS: The evolutionary history of the mitochondrial genome, from its inception as a bacterial endosymbiont, includes massive genomic reduction. Consistent with this overall trend, selection for efficiency of mitochondrial replication and transcription has been hypothesized to favor elimination of extra sequence. Our results, however, suggest that there may be no strong disadvantage to extraneous sequences in salamander mitochondrial genomes, although duplicate rRNA genes may be deleterious.}, }
@article {pmid29279407, year = {2018}, author = {Łukasik, P and Nazario, K and Van Leuven, JT and Campbell, MA and Meyer, M and Michalik, A and Pessacq, P and Simon, C and Veloso, C and McCutcheon, JP}, title = {Multiple origins of interdependent endosymbiotic complexes in a genus of cicadas.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {115}, number = {2}, pages = {E226-E235}, pmid = {29279407}, issn = {1091-6490}, mesh = {Animals ; Bacteria/*classification/*genetics ; Bacterial Physiological Phenomena/*genetics ; Biological Evolution ; Chile ; Genetic Variation ; Genome, Bacterial ; Hemiptera/*microbiology ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {Bacterial endosymbionts that provide nutrients to hosts often have genomes that are extremely stable in structure and gene content. In contrast, the genome of the endosymbiont Hodgkinia cicadicola has fractured into multiple distinct lineages in some species of the cicada genus Tettigades To better understand the frequency, timing, and outcomes of Hodgkinia lineage splitting throughout this cicada genus, we sampled cicadas over three field seasons in Chile and performed genomics and microscopy on representative samples. We found that a single ancestral Hodgkinia lineage has split at least six independent times in Tettigades over the last 4 million years, resulting in complexes of between two and six distinct Hodgkinia lineages per host. Individual genomes in these symbiotic complexes differ dramatically in relative abundance, genome size, organization, and gene content. Each Hodgkinia lineage retains a small set of core genes involved in genetic information processing, but the high level of gene loss experienced by all genomes suggests that extensive sharing of gene products among symbiont cells must occur. In total, Hodgkinia complexes that consist of multiple lineages encode nearly complete sets of genes present on the ancestral single lineage and presumably perform the same functions as symbionts that have not undergone splitting. However, differences in the timing of the splits, along with dissimilar gene loss patterns on the resulting genomes, have led to very different outcomes of lineage splitting in extant cicadas.}, }
@article {pmid29271121, year = {2018}, author = {Feng, H and Wang, L and Wuchty, S and Wilson, ACC}, title = {microRNA regulation in an ancient obligate endosymbiosis.}, journal = {Molecular ecology}, volume = {27}, number = {8}, pages = {1777-1793}, doi = {10.1111/mec.14464}, pmid = {29271121}, issn = {1365-294X}, mesh = {Animals ; Aphids/*genetics/microbiology ; Buchnera/genetics ; Genome, Bacterial/genetics ; Host-Pathogen Interactions/*genetics ; MicroRNAs/*genetics ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Although many insects are associated with obligate bacterial endosymbionts, the mechanisms by which these host/endosymbiont associations are regulated remain mysterious. While microRNAs (miRNAs) have been recently identified as regulators of host/microbe interactions, including host/pathogen and host/facultative endosymbiont interactions, the role miRNAs may play in mediating host/obligate endosymbiont interactions is virtually unknown. Here, we identified conserved miRNAs that potentially mediate symbiotic interactions between aphids and their obligate endosymbiont, Buchnera aphidicola. Using small RNA sequence data from Myzus persicae and Acyrthosiphon pisum, we annotated 93 M. persicae and 89 A. pisum miRNAs, among which 69 were shared. We found 14 miRNAs that were either highly expressed in aphid bacteriome, the Buchnera-housing tissue, or differentially expressed in bacteriome vs. gut, a non-Buchnera-housing tissue. Strikingly, 10 of these 14 miRNAs have been implicated previously in other host/microbe interaction studies. Investigating the interaction networks of these miRNAs using a custom computational pipeline, we identified 103 miRNA::mRNA interactions shared between M. persicae and A. pisum. Functional annotation of the shared mRNA targets revealed only two over-represented cluster of orthologous group categories: amino acid transport and metabolism, and signal transduction mechanisms. Our work supports a role for miRNAs in mediating host/symbiont interactions between aphids and their obligate endosymbiont Buchnera. In addition, our results highlight the probable importance of signal transduction mechanisms to host/endosymbiont coevolution.}, }
@article {pmid29250466, year = {2017}, author = {Šochová, E and Husník, F and Nováková, E and Halajian, A and Hypša, V}, title = {Arsenophonus and Sodalis replacements shape evolution of symbiosis in louse flies.}, journal = {PeerJ}, volume = {5}, number = {}, pages = {e4099}, pmid = {29250466}, issn = {2167-8359}, abstract = {Symbiotic interactions between insects and bacteria are ubiquitous and form a continuum from loose facultative symbiosis to greatly intimate and stable obligate symbiosis. In blood-sucking insects living exclusively on vertebrate blood, obligate endosymbionts are essential for hosts and hypothesized to supplement B-vitamins and cofactors missing from their blood diet. The role and distribution of facultative endosymbionts and their evolutionary significance as seeds of obligate symbioses are much less understood. Here, using phylogenetic approaches, we focus on the Hippoboscidae phylogeny as well as the stability and dynamics of obligate symbioses within this bloodsucking group. In particular, we demonstrate a new potentially obligate lineage of Sodalis co-evolving with the Olfersini subclade of Hippoboscidae. We also show several likely facultative Sodalis lineages closely related to Sodalis praecaptivus (HS strain) and suggest repeated acquisition of novel symbionts from the environment. Similar to Sodalis, Arsenophonus endosymbionts also form both obligate endosymbiotic lineages co-evolving with their hosts (Ornithomyini and Ornithoica groups) as well as possibly facultative infections incongruent with the Hippoboscidae phylogeny. Finally, we reveal substantial diversity of Wolbachia strains detected in Hippoboscidae samples falling into three supergroups: A, B, and the most common F. Altogether, our results prove the associations between Hippoboscoidea and their symbiotic bacteria to undergo surprisingly dynamic, yet selective, evolutionary processes strongly shaped by repeated endosymbiont replacements. Interestingly, obligate symbionts only originate from two endosymbiont genera, Arsenophonus and Sodalis, suggesting that the host is either highly selective about its future obligate symbionts or that these two lineages are the most competitive when establishing symbioses in louse flies.}, }
@article {pmid29243069, year = {2018}, author = {Zhang, XG and Liu, JW and Tang, P and Liu, ZY and Guo, GJ and Sun, QY and Yin, JJ}, title = {Identification of a New Uncompetitive Inhibitor of Adenosine Deaminase from Endophyte Aspergillus niger sp.}, journal = {Current microbiology}, volume = {75}, number = {5}, pages = {565-573}, pmid = {29243069}, issn = {1432-0991}, mesh = {Adenosine Deaminase/chemistry/metabolism ; Adenosine Deaminase Inhibitors/*chemistry/metabolism ; Aspergillus niger/*chemistry/genetics/isolation &amp; purification/metabolism ; Cell Line ; Endophytes/*chemistry/genetics/isolation &amp; purification/metabolism ; Humans ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Plants/*microbiology ; }, abstract = {Adenosine deaminase (ADA) is an enzyme widely distributed from bacteria to humans. ADA is known as a potential therapeutic target for the treatment of lymphoproliferative disorders and cancer. Endophytes are endosymbionts, often bacteria or fungi, which live within plant tissues and internal organs or intercellular space. Endophytes have a broad variety of bioactive metabolites that are used for the identification of novel natural compounds. Here, 54 morphologically distinct endophyte strains were isolated from six plants such as Peganum harmala Linn., Rheum officinale Baill., Gentiana macrophylla Pall., Radix stephaniae tetrandrae, Myrrha, and Equisetum hyemale Linn. The isolated strains were used for the search of ADA inhibitors that resulted in the identification of the strain with the highest inhibition activity, Aspergillus niger sp. Four compounds were isolated from this strain using three-step chromatography procedure, and compound 2 was determined as the compound with the highest inhibition activity of ADA. Based on the results of [1]H and [13]C NMR spectroscopies, compound 2 was identified as 3-(4-nitrophenyl)-5-phenyl isoxazole. We showed that compound 2 was a new uncompetitive inhibitor of ADA with high cytotoxic effect on HepG2 and SMCC-7721 cells (the IC50 values were 0.347 and 0.380 mM, respectively). These results suggest that endophyte strains serve as promising sources for the identification of ADA inhibitors, and compound 2 could be an effective drug in the cancer treatment.}, }
@article {pmid29242567, year = {2017}, author = {Guizzo, MG and Parizi, LF and Nunes, RD and Schama, R and Albano, RM and Tirloni, L and Oldiges, DP and Vieira, RP and Oliveira, WHC and Leite, MS and Gonzales, SA and Farber, M and Martins, O and Vaz, IDS and Oliveira, PL}, title = {A Coxiella mutualist symbiont is essential to the development of Rhipicephalus microplus.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {17554}, pmid = {29242567}, issn = {2045-2322}, mesh = {Animals ; Coxiella/drug effects/genetics/*physiology ; Female ; Genome, Bacterial/genetics ; Larva/drug effects/growth &amp; development/microbiology ; Nymph/drug effects/growth &amp; development/microbiology ; Ovum/drug effects/growth &amp; development/microbiology ; Rhipicephalus/growth &amp; development/*microbiology ; *Symbiosis/drug effects ; Tetracycline/pharmacology ; }, abstract = {The cattle tick Rhipicephalus microplus is a hematophagous ectoparasite that causes important economic losses in livestock. Different species of ticks harbor a symbiont bacterium of the genus Coxiella. It was showed that a Coxiella endosymbiont from R. microplus (CERM) is a vertically transmitted mutualist symbiont, comprising 98% of the 16S rRNA sequences in both eggs and larvae. Sequencing of the bacterial genome revealed genes for biosynthetic pathways for several vitamins and key metabolic cofactors that may provide a nutritional complement to the tick host. The CERM was abundant in ovary and Malpighian tubule of fully engorged female. Tetracycline treatment of either the tick or the vertebrate host reduced levels of bacteria in progeny in 74% for eggs and 90% for larvae without major impact neither on the reproductive fitness of the adult female or on embryo development. However, CERM proved to be essential for the tick to reach the adult life stage, as under antibiotic treatment no tick was able to progress beyond the metanymph stage. Data presented here suggest that interference in the symbiotic CERM-R. microplus relationship may be useful to the development of alternative control methods, highlighting the interdependence between ticks and their endosymbionts.}, }
@article {pmid29234308, year = {2017}, author = {Chrostek, E and Pelz-Stelinski, K and Hurst, GDD and Hughes, GL}, title = {Horizontal Transmission of Intracellular Insect Symbionts via Plants.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {2237}, pmid = {29234308}, issn = {1664-302X}, support = {R21 AI124452/AI/NIAID NIH HHS/United States ; R21 AI129507/AI/NIAID NIH HHS/United States ; U01 CK000512/CK/NCEZID CDC HHS/United States ; }, abstract = {Experimental evidence is accumulating that endosymbionts of phytophagous insects may transmit horizontally via plants. Intracellular symbionts known for manipulating insect reproduction and altering fitness (Rickettsia, Cardinium, Wolbachia, and bacterial parasite of the leafhopper Euscelidius variegatus) have been found to travel from infected insects into plants. Other insects, either of the same or different species can acquire the symbiont from the plant through feeding, and in some cases transfer it to their progeny. These reports prompt many questions regarding how intracellular insect symbionts are delivered to plants and how they affect them. Are symbionts passively transported along the insect-plant-insect path, or do they actively participate in the process? How widespread are these interactions? How does symbiont presence influence the plant? And what conditions are required for the new infection to establish in an insect? From an ecological, evolutionary, and applied perspective, this mode of horizontal transmission could have profound implications if occurring frequently enough or if new stable symbiont infections are established. Transmission of symbionts through plants likely represents an underappreciated means of infection, both in terms of symbiont epidemiology and the movement of symbionts to new host species.}, }
@article {pmid29218749, year = {2018}, author = {Baumgarten, S and Cziesielski, MJ and Thomas, L and Michell, CT and Esherick, LY and Pringle, JR and Aranda, M and Voolstra, CR}, title = {Evidence for miRNA-mediated modulation of the host transcriptome in cnidarian-dinoflagellate symbiosis.}, journal = {Molecular ecology}, volume = {27}, number = {2}, pages = {403-418}, doi = {10.1111/mec.14452}, pmid = {29218749}, issn = {1365-294X}, mesh = {Animals ; Cnidaria/genetics/physiology ; Coral Reefs ; Dinoflagellida/genetics/physiology ; Genome/*genetics ; MicroRNAs/*genetics ; Photosynthesis ; Sea Anemones/genetics/physiology ; Symbiosis/genetics ; Transcriptome/*genetics ; }, abstract = {Reef-building corals and other cnidarians living in symbiotic relationships with intracellular, photosynthetic dinoflagellates in the genus Symbiodinium undergo transcriptomic changes during infection with the algae and maintenance of the endosymbiont population. However, the precise regulatory mechanisms modulating the host transcriptome are unknown. Here, we report apparent post-transcriptional gene regulation by miRNAs in the sea anemone Aiptasia, a model system for cnidarian-dinoflagellate endosymbiosis. Aiptasia encodes mainly species-specific miRNAs, and there appears to have been recent differentiation within the Aiptasia genome of miRNAs that are commonly conserved among anthozoan cnidarians. Analysis of miRNA expression showed that both conserved and species-specific miRNAs are differentially expressed in response to endosymbiont infection. Using cross-linking immunoprecipitation of Argonaute, the central protein of the miRNA-induced silencing complex, we identified miRNA binding sites on a transcriptome-wide scale and found that the targets of the miRNAs regulated in response to symbiosis include genes previously implicated in biological processes related to Symbiodinium infection. Our study shows that cnidarian miRNAs recognize their mRNA targets via high-complementarity target binding and suggests that miRNA-mediated modulations of genes and pathways are important during the onset and maintenance of cnidarian-dinoflagellate endosymbiosis.}, }
@article {pmid29217594, year = {2018}, author = {Xiang, T and Jinkerson, RE and Clowez, S and Tran, C and Krediet, CJ and Onishi, M and Cleves, PA and Pringle, JR and Grossman, AR}, title = {Glucose-Induced Trophic Shift in an Endosymbiont Dinoflagellate with Physiological and Molecular Consequences.}, journal = {Plant physiology}, volume = {176}, number = {2}, pages = {1793-1807}, pmid = {29217594}, issn = {1532-2548}, mesh = {Animals ; Dinoflagellida/drug effects/genetics/*physiology ; Gene Expression Profiling ; Gene Expression Regulation ; Glucose/*pharmacology ; Heterotrophic Processes ; Photosynthesis ; Sea Anemones/*parasitology ; Symbiosis ; *Transcriptome ; }, abstract = {Interactions between the dinoflagellate endosymbiont Symbiodinium and its cnidarian hosts (e.g. corals, sea anemones) are the foundation of coral-reef ecosystems. Carbon flow between the partners is a hallmark of this mutualism, but the mechanisms governing this flow and its impact on symbiosis remain poorly understood. We showed previously that although Symbiodinium strain SSB01 can grow photoautotrophically, it can grow mixotrophically or heterotrophically when supplied with Glc, a metabolite normally transferred from the alga to its host. Here we show that Glc supplementation of SSB01 cultures causes a loss of pigmentation and photosynthetic activity, disorganization of thylakoid membranes, accumulation of lipid bodies, and alterations of cell-surface morphology. We used global transcriptome analyses to determine if these physiological changes were correlated with changes in gene expression. Glc-supplemented cells exhibited a marked reduction in levels of plastid transcripts encoding photosynthetic proteins, although most nuclear-encoded transcripts (including those for proteins involved in lipid synthesis and formation of the extracellular matrix) exhibited little change in their abundances. However, the altered carbon metabolism in Glc-supplemented cells was correlated with modest alterations (approximately 2x) in the levels of some nuclear-encoded transcripts for sugar transporters. Finally, Glc-bleached SSB01 cells appeared unable to efficiently populate anemone larvae. Together, these results suggest links between energy metabolism and cellular physiology, morphology, and symbiotic interactions. However, the results also show that in contrast to many other organisms, Symbiodinium can undergo dramatic physiological changes that are not reflected by major changes in the abundances of nuclear-encoded transcripts and thus presumably reflect posttranscriptional regulatory processes.}, }
@article {pmid29215202, year = {2018}, author = {Rock, DI and Smith, AH and Joffe, J and Albertus, A and Wong, N and O'Connor, M and Oliver, KM and Russell, JA}, title = {Context-dependent vertical transmission shapes strong endosymbiont community structure in the pea aphid, Acyrthosiphon pisum.}, journal = {Molecular ecology}, volume = {27}, number = {8}, pages = {2039-2056}, doi = {10.1111/mec.14449}, pmid = {29215202}, issn = {1365-294X}, mesh = {Animals ; Aphids/genetics/*microbiology ; Coinfection/genetics/*microbiology ; Coxiellaceae/genetics/pathogenicity ; *Ecology ; Host Specificity/genetics ; Microbiota/genetics ; Peas/parasitology ; Serratia/genetics/pathogenicity ; Symbiosis/*genetics ; }, abstract = {Animal-associated microbiomes are often comprised of structured, multispecies communities, with particular microbes showing trends of co-occurrence or exclusion. Such structure suggests variable community stability, or variable costs and benefits-possibilities with implications for symbiont-driven host adaptation. In this study, we performed systematic screening for maternally transmitted, facultative endosymbionts of the pea aphid, Acyrthosiphon pisum. Sampling across six locales, with up to 5 years of collection in each, netted significant and consistent trends of community structure. Co-infections between Serratia symbiotica and Rickettsiella viridis were more common than expected, while Rickettsia and X-type symbionts colonized aphids with Hamiltonella defensa more often than expected. Spiroplasma co-infected with other endosymbionts quite rarely, showing tendencies to colonize as a single species monoculture. Field estimates of maternal transmission rates help to explain our findings: while Serratia and Rickettsiella improved each other's transmission, Spiroplasma reduced transmission rates of co-infecting endosymbionts. In summary, our findings show that North American pea aphids harbour recurring combinations of facultative endosymbionts. Common symbiont partners play distinct roles in pea aphid biology, suggesting the creation of "generalist" aphids receiving symbiont-based defence against multiple ecological stressors. Multimodal selection, at the host level, may thus partially explain our results. But more conclusively, our findings show that within-host microbe interactions, and their resulting impacts on transmission rates, are an important determinant of community structure. Widespread distributions of heritable symbionts across plants and invertebrates hint at the far-reaching implications for these findings, and our work further shows the benefits of symbiosis research within a natural context.}, }
@article {pmid29214346, year = {2018}, author = {Singhal, K and Mohanty, S}, title = {Comparative genomics reveals the presence of putative toxin-antitoxin system in Wolbachia genomes.}, journal = {Molecular genetics and genomics : MGG}, volume = {293}, number = {2}, pages = {525-540}, pmid = {29214346}, issn = {1617-4623}, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/classification/genetics ; Drosophila/microbiology ; Drosophila melanogaster/microbiology ; Genes, Bacterial/genetics ; Genetic Variation ; Genome, Bacterial/*genetics ; Genomics/*methods ; Host-Pathogen Interactions ; Phylogeny ; Sequence Homology, Amino Acid ; Toxin-Antitoxin Systems/*genetics ; Wolbachia/*genetics/isolation &amp; purification/physiology ; }, abstract = {Multiple toxin-antitoxin (TA) systems are housed in different locations within the bacterial genome and are known to be associated with various cellular processes and stress-related adaptation. In endosymbionts, although, the TA system has scarce occurrence but studies have highlighted its presence in enhancing host-symbiont interactions. Wolbachia, an obligate endosymbiont, has recently been proposed as a biocontrol agent which may be helpful in controlling vector-borne diseases. There are reports suggesting the role of TA system in inducing cytoplasmic incompatibility in case of Wolbachia, however, the underlying mechanism is still not known. The present study, therefore, aims at exploring the diversity of TA system in four novel (sourced from India) and three reference genomes (NCBI) of Wolbachia strains. Interestingly, we found several putative toxins and antitoxins of RelEB family of Type II TA system in these Wolbachia genomes. The results show wMel genome possessed more number of putative TA loci than wRi genome. In addition, searching through the other sequenced Wolbachia genomes in NCBI, a complete absence of TA system was observed in Wolbachia-infected nematodes. The sequence-wide analysis of all the putative RelEB proteins present amongst the Wolbachia endosymbiont and within the free-living bacterial genomes reveal strain-specific similarities and conserved sequences. However, large amount of sequence diversity was observed between Wolbachia and free-living bacteria. Understanding this sequence variation may help shed light on the differences between these two forms of bacteria and could also explain their niche preferences.}, }
@article {pmid29213256, year = {2017}, author = {Ponce-de-Leon, M and Tamarit, D and Calle-Espinosa, J and Mori, M and Latorre, A and Montero, F and Pereto, J}, title = {Determinism and Contingency Shape Metabolic Complementation in an Endosymbiotic Consortium.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {2290}, pmid = {29213256}, issn = {1664-302X}, abstract = {Bacterial endosymbionts and their insect hosts establish an intimate metabolic relationship. Bacteria offer a variety of essential nutrients to their hosts, whereas insect cells provide the necessary sources of matter and energy to their tiny metabolic allies. These nutritional complementations sustain themselves on a diversity of metabolite exchanges between the cell host and the reduced yet highly specialized bacterial metabolism-which, for instance, overproduces a small set of essential amino acids and vitamins. A well-known case of metabolic complementation is provided by the cedar aphid Cinara cedri that harbors two co-primary endosymbionts, Buchnera aphidicola BCc and Ca. Serratia symbiotica SCc, and in which some metabolic pathways are partitioned between different partners. Here we present a genome-scale metabolic network (GEM) for the bacterial consortium from the cedar aphid iBSCc. The analysis of this GEM allows us the confirmation of cases of metabolic complementation previously described by genome analysis (i.e., tryptophan and biotin biosynthesis) and the redefinition of an event of metabolic pathway sharing between the two endosymbionts, namely the biosynthesis of tetrahydrofolate. In silico knock-out experiments with iBSCc showed that the consortium metabolism is a highly integrated yet fragile network. We also have explored the evolutionary pathways leading to the emergence of metabolic complementation between reduced metabolisms starting from individual, complete networks. Our results suggest that, during the establishment of metabolic complementation in endosymbionts, adaptive evolution is significant in the case of tryptophan biosynthesis, whereas vitamin production pathways seem to adopt suboptimal solutions.}, }
@article {pmid29204318, year = {2017}, author = {Akhter, S and Aziz, RK and Kashef, MT and Ibrahim, ES and Bailey, B and Edwards, RA}, title = {Kullback Leibler divergence in complete bacterial and phage genomes.}, journal = {PeerJ}, volume = {5}, number = {}, pages = {e4026}, pmid = {29204318}, issn = {2167-8359}, abstract = {The amino acid content of the proteins encoded by a genome may predict the coding potential of that genome and may reflect lifestyle restrictions of the organism. Here, we calculated the Kullback-Leibler divergence from the mean amino acid content as a metric to compare the amino acid composition for a large set of bacterial and phage genome sequences. Using these data, we demonstrate that (i) there is a significant difference between amino acid utilization in different phylogenetic groups of bacteria and phages; (ii) many of the bacteria with the most skewed amino acid utilization profiles, or the bacteria that host phages with the most skewed profiles, are endosymbionts or parasites; (iii) the skews in the distribution are not restricted to certain metabolic processes but are common across all bacterial genomic subsystems; (iv) amino acid utilization profiles strongly correlate with GC content in bacterial genomes but very weakly correlate with the G+C percent in phage genomes. These findings might be exploited to distinguish coding from non-coding sequences in large data sets, such as metagenomic sequence libraries, to help in prioritizing subsequent analyses.}, }
@article {pmid29204150, year = {2017}, author = {Ranjbar Sistani, N and Kaul, HP and Desalegn, G and Wienkoop, S}, title = {Rhizobium Impacts on Seed Productivity, Quality, and Protection of Pisum sativum upon Disease Stress Caused by Didymella pinodes: Phenotypic, Proteomic, and Metabolomic Traits.}, journal = {Frontiers in plant science}, volume = {8}, number = {}, pages = {1961}, pmid = {29204150}, issn = {1664-462X}, support = {P 24870/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {In field peas, ascochyta blight is one of the most common fungal diseases caused by Didymella pinodes. Despite the high diversity of pea cultivars, only little resistance has been developed until to date, still leading to significant losses in grain yield. Rhizobia as plant growth promoting endosymbionts are the main partners for establishment of symbiosis with pea plants. The key role of Rhizobium as an effective nitrogen source for legumes seed quality and quantity improvement is in line with sustainable agriculture and food security programs. Besides these growth promoting effects, Rhizobium symbiosis has been shown to have a priming impact on the plants immune system that enhances resistance against environmental perturbations. This is the first integrative study that investigates the effect of Rhizobium leguminosarum bv. viceae (Rlv) on phenotypic seed quality, quantity and fungal disease in pot grown pea (Pisum sativum) cultivars with two different resistance levels against D. pinodes through metabolomics and proteomics analyses. In addition, the pathogen effects on seed quantity components and quality are assessed at morphological and molecular level. Rhizobium inoculation decreased disease severity by significant reduction of seed infection level. Rhizobium symbiont enhanced yield through increased seed fresh and dry weights based on better seed filling. Rhizobium inoculation also induced changes in seed proteome and metabolome involved in enhanced P. sativum resistance level against D. pinodes. Besides increased redox and cell wall adjustments light is shed on the role of late embryogenesis abundant proteins and metabolites such as the seed triterpenoid Soyasapogenol. The results of this study open new insights into the significance of symbiotic Rhizobium interactions for crop yield, health and seed quality enhancement and reveal new metabolite candidates involved in pathogen resistance.}, }
@article {pmid29197022, year = {2017}, author = {Zhang, CM and Li, NX and Zhang, TT and Qiu, ZX and Li, Y and Li, LW and Liu, JZ}, title = {Endosymbiont CLS-HI plays a role in reproduction and development of Haemaphysalis longicornis.}, journal = {Experimental &amp; applied acarology}, volume = {73}, number = {3-4}, pages = {429-438}, pmid = {29197022}, issn = {1572-9702}, mesh = {Animals ; Coxiella/*physiology ; Feeding Behavior ; Female ; Ixodidae/growth &amp; development/*microbiology/*physiology ; Malpighian Tubules/microbiology ; Ovary/microbiology ; *Oviposition ; Reproduction ; *Symbiosis ; }, abstract = {Coxiella-like endosymbiont (CLS-Hl) is a primary endosymbiont of Haemaphysalis longicornis. CLS-Hl infects tick special tissues and its prevalence is 100% in ovaries and Malpighian tubules. Tetracycline was injected into females, which then fed on rabbits also treated with tetracycline. The densities of CLS-Hl were measured by semi-quantitative PCR. CLS-Hl densities in ovaries and Malpighian tubes of H. longicornis had significant effects on engorged weight, feeding time, number of eggs, oviposition period, and hatching period. These findings suggested that CLS-Hl plays a role in the reproduction and development of H. longicornis.}, }
@article {pmid29194875, year = {2018}, author = {Crüsemann, M and Reher, R and Schamari, I and Brachmann, AO and Ohbayashi, T and Kuschak, M and Malfacini, D and Seidinger, A and Pinto-Carbó, M and Richarz, R and Reuter, T and Kehraus, S and Hallab, A and Attwood, M and Schiöth, HB and Mergaert, P and Kikuchi, Y and Schäberle, TF and Kostenis, E and Wenzel, D and Müller, CE and Piel, J and Carlier, A and Eberl, L and König, GM}, title = {Heterologous Expression, Biosynthetic Studies, and Ecological Function of the Selective Gq-Signaling Inhibitor FR900359.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {57}, number = {3}, pages = {836-840}, doi = {10.1002/anie.201707996}, pmid = {29194875}, issn = {1521-3773}, mesh = {Animals ; Bombyx/metabolism ; Chromosomes, Artificial, Bacterial ; Computational Biology ; Depsipeptides/*biosynthesis/metabolism/*pharmacology ; Escherichia coli/genetics ; GTP-Binding Protein alpha Subunits, Gq-G11/*metabolism ; Gene Transfer Techniques ; HEK293 Cells ; Humans ; Insect Proteins/*metabolism ; Multigene Family ; Peptide Synthases/genetics ; Primulaceae/chemistry ; Sf9 Cells ; Signal Transduction/*drug effects ; Tandem Mass Spectrometry ; }, abstract = {The cyclic depsipeptide FR900359 (FR), isolated from the tropical plant Ardisia crenata, is a strong and selective inhibitor of Gq proteins, making it an indispensable pharmacological tool to study Gq-related processes, as well as a promising drug candidate. Gq inhibition is a novel mode of action for defense chemicals and crucial for the ecological function of FR, as shown by in vivo experiments in mice, its affinity to insect Gq proteins, and insect toxicity studies. The uncultured endosymbiont of A. crenata was sequenced, revealing the FR nonribosomal peptide synthetase (frs) gene cluster. We here provide a detailed model of FR biosynthesis, supported by in vitro enzymatic and bioinformatic studies, and the novel analogue AC-1, which demonstrates the flexibility of the FR starter condensation domains. Finally, expression of the frs genes in E. coli led to heterologous FR production in a cultivable, bacterial host for the first time.}, }
@article {pmid29194776, year = {2018}, author = {Kubiak, K and Sielawa, H and Chen, W and Dzika, E}, title = {Endosymbiosis and its significance in dermatology.}, journal = {Journal of the European Academy of Dermatology and Venereology : JEADV}, volume = {32}, number = {3}, pages = {347-354}, doi = {10.1111/jdv.14721}, pmid = {29194776}, issn = {1468-3083}, mesh = {Animals ; *Host-Pathogen Interactions ; Humans ; Insecta/microbiology ; Skin/*microbiology/*parasitology/virology ; Skin Diseases/*microbiology/*parasitology/virology ; *Symbiosis ; Wolbachia/physiology ; }, abstract = {Proposed at the beginning of the twentieth century to explain the origin of eukaryotic organelles from prokaryotes, endosymbiosis is now medically defined by various interaction patterns between microorganisms and their residing hosts, best exemplified by the bacterial endosymbiont Wolbachia identified in arthropods and filarial nematodes, which can influence normal development, reproduction, survival and transmission of the hosts. Based on the transmission modes, vertical or horizontal, and the function of the endosymbionts, the host-symbiont dependence can be divided into primary or secondary. In dermatology, the role of endosymbionts in skin ectoparasitosis has aroused great interests in the past years. Riesia pediculicola is a primary bacterial endosymbiont in body lice Pediculus humanus, and supplement their hosts with vitamin B, especially pantothenic acid. In cimicosis, the Gram-negative Wolbachia can synthesize biotin and riboflavin, which are crucial for the growth and reproduction of the bedbug Cimex lectularius. In human demodicosis and rosacea, further study is required to prove the pathogenic role of the Gram-negative bacteria Bacillus oleronius or the Gram-positive bacteria Bacillus cereus demonstrated in the Demodex mites. The high infection rate of adult female ticks Ixodes ricinus with the Gram-negative bacteria Midichloria mitochondrii present in the mitochondria in diverse ovarian cells, with the high seroprevalence rate in tick-exposed subjects, raises the possibility that this non-pathogenic endosymbiont may play a role in immune response and successful transmission of the tick-borne pathogen. The anaerobic protozoan Trichomonas vaginalis and bacteria Mycoplasma hominis are two obligate parasites in the urogenital epithelium, with partially overlapping symptoms. Intracellular localization of Mycoplasma hominis can avoid host immune response and penetration of antibiotics, while Trichomonas vaginalis infected with Mycoplasma hominis seems to have a higher cytopathic activity and amoeboid transformation rate. Further study on the biology and pathogenesis of different endosymbionts in dermatological parasitosis will help for the development of new treatment modalities.}, }
@article {pmid29192219, year = {2017}, author = {Frago, E and Mala, M and Weldegergis, BT and Yang, C and McLean, A and Godfray, HCJ and Gols, R and Dicke, M}, title = {Symbionts protect aphids from parasitic wasps by attenuating herbivore-induced plant volatiles.}, journal = {Nature communications}, volume = {8}, number = {1}, pages = {1860}, pmid = {29192219}, issn = {2041-1723}, mesh = {Animals ; Aphids/*microbiology/*parasitology ; Enterobacteriaceae/physiology ; *Herbivory ; Host-Parasite Interactions/*physiology ; Symbiosis/*physiology ; Vicia faba/metabolism/physiology ; Volatile Organic Compounds/metabolism ; Wasps/*physiology ; }, abstract = {Plants respond to insect attack by releasing blends of volatile chemicals that attract their herbivores' specific natural enemies, while insect herbivores may carry endosymbiotic microorganisms that directly improve herbivore survival after natural enemy attack. Here we demonstrate that the two phenomena can be linked. Plants fed upon by pea aphids release volatiles that attract parasitic wasps, and the pea aphid can carry facultative endosymbiotic bacteria that prevent the development of the parasitic wasp larva and thus markedly improve aphid survival after wasp attack. We show that these endosymbionts also attenuate the systemic release of volatiles by plants after aphid attack, reducing parasitic wasp recruitment and increasing aphid fitness. Our results reveal a novel mechanism through which symbionts can benefit their hosts and emphasise the importance of considering the microbiome in understanding insect ecological interactions.}, }
@article {pmid29191622, year = {2018}, author = {Gosavi, SM and Kharat, SS and Kumkar, P and Navarange, SS}, title = {Interplay between behavior, morphology and physiology supports lepidophagy in the catfish Pachypterus khavalchor (Siluriformes: Horabagridae).}, journal = {Zoology (Jena, Germany)}, volume = {126}, number = {}, pages = {185-191}, doi = {10.1016/j.zool.2017.07.003}, pmid = {29191622}, issn = {1873-2720}, mesh = {Animals ; Catfishes/*anatomy &amp; histology/physiology ; Chitinases/metabolism ; Digestion/physiology ; *Eating/physiology ; Female ; Gastrointestinal Microbiome ; *Lepidoptera ; *Predatory Behavior/physiology ; Symbiosis/physiology ; }, abstract = {The present study demonstrates the scale-eating behavior of a siluroid catfish, Pachypterus khavalchor, and the role of its oral structure and bacterial endosymbionts in shaping this lepidophagous habit. Scale-eating behavior in P. khavalchor was studied using a series of behavioral experiments. P. khavalchor was found to feed only on the scales of live fish and never of dead fish, even after 72h of starvation. It was nocturnal in habit and attacked all species that were used as prey. Attacking behavior showed extensive chasing of prey species followed by a powerful random strike at the flank or close to the caudal region in posterior oblique position. After a strike, P. khavalchor was found to immediately turn back and pick up the falling dislodged scales. SEM analysis of oral structures of P. khavalchor revealed three different types of teeth arranged in specific order on the upper jaw, lower jaw and pharyngeal region that could facilitate their lepidophagous habit. Teeth of upper and lower jaws are likely to help in dislodging the scales and pharyngeal teeth may help to engulf the scales. Gut microflora analysis and enzyme assay revealed two isolates, namely Bacillus pumilus and Bacillus licheniformis, which were positive for chitinase production. These two isolates were found to be capable of producing chitinase indicating that they are likely to be involved in the digestion of chitin-rich scales in the host fish gut. An in vitro scale degradation assay further strengthens the results since both isolates were found to be efficient in chitinase production and degradation of scales.}, }
@article {pmid29188381, year = {2017}, author = {Rahimi-Kaldeh, S and Ashouri, A and Bandani, A and Tomioka, K}, title = {The effect of Wolbachia on diapause, fecundity, and clock gene expression in Trichogramma brassicae (Hymenoptera: Trichogrammatidae).}, journal = {Development genes and evolution}, volume = {227}, number = {6}, pages = {401-410}, pmid = {29188381}, issn = {1432-041X}, mesh = {Animals ; CLOCK Proteins/*genetics ; *Diapause ; Female ; Gene Expression ; Insect Proteins/*genetics ; Photoperiod ; RNA, Messenger ; Wasps/*genetics/*physiology ; Wolbachia/*physiology ; }, abstract = {The short day lengths of late summer in moderate regions are used to induce diapause in various insects. Many studies have shown the maternal effect of photoperiod on diapause induction of Trichogramma wasps, but there is no study to show the relationship between photoperiodic regimes and clock genes in these useful biological control agents. Here, we investigated the role of photoperiods on diapause, fecundity, and clock gene expression (clk, cyc, cry2, per, and timeout) in asexual and sexual Trichogramma brassicae as a model insect to find any differences between two strains. Asexual strain was infected by Wolbachia, an endosymbiont bacterium. The diapause percentage was significantly higher under short days (8 h in sexual and 12 h in the asexual T. brassicae), although the diapause percentage of the sexual strain was significantly higher than the asexual one in all the photoperiods. The ANOVA revealed no significant changes between different photoperiods in the clock gene expression in the sexual strain but significant photoperiodic changes in clk, cyc, and timeout in the asexual strain. Our results showed that the mRNA levels of clock genes of asexual T. brassicae were significantly lower than those of sexual strain. The fecundity was significantly higher in the asexual strain. These results suggest that Wolbachia infection makes disturbance on the clock gene expression which consequently reduces the percentage of diapause but increases the fecundity in asexual T. brassicae.}, }
@article {pmid29187976, year = {2017}, author = {Conner, WR and Blaxter, ML and Anfora, G and Ometto, L and Rota-Stabelli, O and Turelli, M}, title = {Genome comparisons indicate recent transfer of wRi-like Wolbachia between sister species Drosophila suzukii and D. subpulchrella.}, journal = {Ecology and evolution}, volume = {7}, number = {22}, pages = {9391-9404}, pmid = {29187976}, issn = {2045-7758}, support = {R01 GM104325/GM/NIGMS NIH HHS/United States ; }, abstract = {Wolbachia endosymbionts may be acquired by horizontal transfer, by introgression through hybridization between closely related species, or by cladogenic retention during speciation. All three modes of acquisition have been demonstrated, but their relative frequency is largely unknown. Drosophila suzukii and its sister species D. subpulchrella harbor Wolbachia, denoted wSuz and wSpc, very closely related to wRi, identified in California populations of D. simulans. However, these variants differ in their induced phenotypes: wRi causes significant cytoplasmic incompatibility (CI) in D. simulans, but CI has not been detected in D. suzukii or D. subpulchrella. Our draft genomes of wSuz and wSpc contain full-length copies of 703 of the 734 single-copy genes found in wRi. Over these coding sequences, wSuz and wSpc differ by only 0.004% (i.e., 28 of 704,883 bp); they are sisters relative to wRi, from which each differs by 0.014%-0.015%. Using published data from D. melanogaster, Nasonia wasps and Nomada bees to calibrate relative rates of Wolbachia versus host nuclear divergence, we conclude that wSuz and wSpc are too similar-by at least a factor of 100-to be plausible candidates for cladogenic transmission. These three wRi-like Wolbachia, which differ in CI phenotype in their native hosts, have different numbers of orthologs of genes postulated to contribute to CI; and the CI loci differ at several nucleotides that may account for the CI difference. We discuss the general problem of distinguishing alternative modes of Wolbachia acquisition, focusing on the difficulties posed by limited knowledge of variation in absolute and relative rates of molecular evolution for host nuclear genomes, mitochondria, and Wolbachia.}, }
@article {pmid29186143, year = {2017}, author = {Klueter, A and Trapani, J and Archer, FI and McIlroy, SE and Coffroth, MA}, title = {Comparative growth rates of cultured marine dinoflagellates in the genus Symbiodinium and the effects of temperature and light.}, journal = {PloS one}, volume = {12}, number = {11}, pages = {e0187707}, pmid = {29186143}, issn = {1932-6203}, mesh = {Dinoflagellida/*growth &amp; development ; *Light ; *Marine Biology ; *Temperature ; }, abstract = {Many dinoflagellate microalgae of the genus Symbiodinium form successful symbioses with a large group of metazoans and selected protists. Yet knowledge of growth kinetics of these endosymbionts and their ecological and evolutionary implications is limited. We used a Bayesian biphasic generalized logistic model to estimate key parameters of the growth of five strains of cultured Symbiodinium, S. microadriaticum (cp-type A194; strain 04-503), S. microadriaticum (cp-type A194; strain CassKB8), S. minutum (cp-type B184; strain Mf 1.05b.01.SCI.01), S. psygmophilum (cp-type B224; strain Mf 11.05b.01) and S. trenchii (cp-type D206; strain Mf 2.2b), grown in four different combinations of temperature and light. Growth kinetics varied among Symbiodinium strains and across treatments. Biphasic growth was especially evident for S. minutum and S. psygmophilum across all treatments. Monophasic growth was more common when final asymptotic densities were relatively low (~ 200 million cells ml-1). All species tended to grow faster and / or reached a higher asymptote at 26°C than at 18°C. The fastest growth was exhibited by S. minutum, with an approximate four-fold increase in estimated cell density after 60 days. The strongest effect of light was seen in S. trenchii, in which increasing light levels resulted in a decrease in initial growth rate, and an increase in asymptotic density, time when growth rate was at its maximum, final growth rate, and maximum growth rate. Results suggest that Symbiodinium species have different photokinetic and thermal optima, which may affect their growth-related nutritional physiology and allow them to modify their response to environmental changes.}, }
@article {pmid29184190, year = {2017}, author = {Mondo, SJ and Lastovetsky, OA and Gaspar, ML and Schwardt, NH and Barber, CC and Riley, R and Sun, H and Grigoriev, IV and Pawlowska, TE}, title = {Bacterial endosymbionts influence host sexuality and reveal reproductive genes of early divergent fungi.}, journal = {Nature communications}, volume = {8}, number = {1}, pages = {1843}, pmid = {29184190}, issn = {2041-1723}, support = {R01 GM019629/GM/NIGMS NIH HHS/United States ; }, mesh = {Burkholderia/*physiology ; Fungal Proteins/*genetics ; *Gene Expression Regulation, Fungal ; Gene Regulatory Networks ; Mycorrhizae/genetics ; Phylogeny ; Reproduction, Asexual/genetics/physiology ; Rhizopus/genetics/*physiology ; Spores, Fungal/physiology ; Symbiosis/*genetics ; }, abstract = {Many heritable mutualisms, in which beneficial symbionts are transmitted vertically between host generations, originate as antagonisms with parasite dispersal constrained by the host. Only after the parasite gains control over its transmission is the symbiosis expected to transition from antagonism to mutualism. Here, we explore this prediction in the mutualism between the fungus Rhizopus microsporus (Rm, Mucoromycotina) and a beta-proteobacterium Burkholderia, which controls host asexual reproduction. We show that reproductive addiction of Rm to endobacteria extends to mating, and is mediated by the symbiont gaining transcriptional control of the fungal ras2 gene, which encodes a GTPase central to fungal reproductive development. We also discover candidate G-protein-coupled receptors for the perception of trisporic acids, mating pheromones unique to Mucoromycotina. Our results demonstrate that regulating host asexual proliferation and modifying its sexual reproduction are sufficient for the symbiont's control of its own transmission, needed for antagonism-to-mutualism transition in heritable symbioses. These properties establish the Rm-Burkholderia symbiosis as a powerful system for identifying reproductive genes in Mucoromycotina.}, }
@article {pmid29181449, year = {2017}, author = {Mann, E and Stouthamer, CM and Kelly, SE and Dzieciol, M and Hunter, MS and Schmitz-Esser, S}, title = {Transcriptome Sequencing Reveals Novel Candidate Genes for Cardinium hertigii-Caused Cytoplasmic Incompatibility and Host-Cell Interaction.}, journal = {mSystems}, volume = {2}, number = {6}, pages = {}, pmid = {29181449}, issn = {2379-5077}, abstract = {Cytoplasmic incompatibility (CI) is an intriguing, widespread, symbiont-induced reproductive failure that decreases offspring production of arthropods through crossing incompatibility of infected males with uninfected females or with females infected with a distinct symbiont genotype. For years, the molecular mechanism of CI remained unknown. Recent genomic, proteomic, biochemical, and cell biological studies have contributed to understanding of CI in the alphaproteobacterium Wolbachia and implicate genes associated with the WO prophage. Besides a recently discovered additional lineage of alphaproteobacterial symbionts only moderately related to Wolbachia, Cardinium (Bacteroidetes) is the only other symbiont known to cause CI, and genomic evidence suggests that it has very little homology with Wolbachia and evolved this phenotype independently. Here, we present the first transcriptomic study of the CI Cardinium strain cEper1, in its natural host, Encarsia suzannae, to detect important CI candidates and genes involved in the insect-Cardinium symbiosis. Highly expressed transcripts included genes involved in manipulating ubiquitination, apoptosis, and host DNA. Female-biased genes encoding ribosomal proteins suggest an increase in general translational activity of Cardinium in female wasps. The results confirm previous genomic analyses that indicated that Wolbachia and Cardinium utilize different genes to induce CI, and transcriptome patterns further highlight expression of some common pathways that these bacteria use to interact with the host and potentially cause this enigmatic and fundamental manipulation of host reproduction. IMPORTANCE The majority of insects carry maternally inherited intracellular bacteria that are important in their hosts' biology, ecology, and evolution. Some of these bacterial symbionts cause a reproductive failure known as cytoplasmic incompatibility (CI). In CI, the mating of symbiont-infected males and uninfected females produces few or no daughters. The CI symbiont then spreads and can have a significant impact on the insect host population. Cardinium, a bacterial endosymbiont of the parasitoid wasp Encarsia in the Bacteroidetes, is the only bacterial lineage known to cause CI outside the Alphaproteobacteria, where Wolbachia and another recently discovered CI symbiont reside. Here, we sought insight into the gene expression of a CI-inducing Cardinium strain in its natural host, Encarsia suzannae. Our study provides the first insights into the Cardinium transcriptome and provides support for the hypothesis that Wolbachia and Cardinium target similar host pathways with distinct and largely unrelated sets of genes.}, }
@article {pmid29178531, year = {2017}, author = {Kwan, JY and Griggs, R and Chicana, B and Miller, C and Swei, A}, title = {Vertical vs. horizontal transmission of the microbiome in a key disease vector, Ixodes pacificus.}, journal = {Molecular ecology}, volume = {26}, number = {23}, pages = {6578-6589}, doi = {10.1111/mec.14391}, pmid = {29178531}, issn = {1365-294X}, mesh = {Animals ; Biodiversity ; Borrelia/classification ; California ; Disease Vectors ; Female ; Ixodes/*microbiology ; Larva/microbiology ; Male ; *Microbiota ; Nymph/microbiology ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification ; Symbiosis ; }, abstract = {Vector-borne pathogens are increasingly found to interact with the vector's microbiome, influencing disease transmission dynamics. However, the processes that regulate the formation and development of the microbiome are largely unexplored for most tick species, an emerging group of disease vectors. It is not known how much of the tick microbiome is acquired through vertical transmission vs. horizontally from the environment or interactions with bloodmeal sources. Using 16S rRNA sequencing, we examined the microbiome of Ixodes pacificus, the vector of Lyme disease in the western USA, across life stages and infection status. We also characterized microbiome diversity in field and laboratory-collected nymphal ticks to determine how the surrounding environment affects microbiome diversity. We found a decrease in both species richness and evenness as the tick matures from larva to adult. When the dominant Rickettsial endosymbiont was computationally removed from the tick microbial community, we found that infected nymphs had lower species evenness than uninfected ticks, suggesting that lower microbiome diversity is associated with pathogen transmission in wild-type ticks. Furthermore, laboratory-reared nymph microbiome diversity was found to be compositionally distinct and significantly depauperate relative to field-collected nymphs. These results highlight unique patterns in the microbial community of I. pacificus that is distinct from other tick species. We provide strong evidence that ticks acquire a significant portion of their microbiome through exposure to their environment despite a loss of overall diversity through life stages. We provide evidence that loss of microbial diversity is at least in part due to elimination of microbial diversity with bloodmeal feeding but other factors may also play a role.}, }
@article {pmid29177480, year = {2017}, author = {Wang, Z and Wu, M}, title = {Comparative Genomic Analysis of Acanthamoeba Endosymbionts Highlights the Role of Amoebae as a "Melting Pot" Shaping the Rickettsiales Evolution.}, journal = {Genome biology and evolution}, volume = {9}, number = {11}, pages = {3214-3224}, pmid = {29177480}, issn = {1759-6653}, mesh = {Acanthamoeba/*microbiology/physiology ; Alphaproteobacteria/classification/*genetics/physiology ; Biological Evolution ; Gene Transfer, Horizontal ; Phylogeny ; Symbiosis ; }, abstract = {Amoebae have been considered as a genetic "melting pot" for its symbionts, facilitating genetic exchanges of the bacteria that co-inhabit the same host. To test the "melting pot" hypothesis, we analyzed six genomes of amoeba endosymbionts within Rickettsiales, four of which belong to Holosporaceae family and two to Candidatus Midichloriaceae. For the first time, we identified plasmids in obligate amoeba endosymbionts, which suggests conjugation as a potential mechanism for lateral gene transfers (LGTs) that underpin the "melting pot" hypothesis. We found strong evidence of recent LGTs between the Rickettsiales amoeba endosymbionts, suggesting that the LGTs are continuous and ongoing. In addition, comparative genomic and phylogenomic analyses revealed pervasive and recurrent LGTs between Rickettsiales and distantly related amoeba-associated bacteria throughout the Rickettsiales evolution. Many of these exchanged genes are important for amoeba-symbiont interactions, including genes in transport system, antibiotic resistance, stress response, and bacterial virulence, suggesting that LGTs have played important roles in the adaptation of endosymbionts to their intracellular habitats. Surprisingly, we found little evidence of LGTs between amoebae and their bacterial endosymbionts. Our study strongly supports the "melting pot" hypothesis and highlights the role of amoebae in shaping the Rickettsiales evolution.}, }
@article {pmid29175860, year = {2017}, author = {Gegner, HM and Ziegler, M and Rädecker, N and Buitrago-López, C and Aranda, M and Voolstra, CR}, title = {High salinity conveys thermotolerance in the coral model Aiptasia.}, journal = {Biology open}, volume = {6}, number = {12}, pages = {1943-1948}, pmid = {29175860}, issn = {2046-6390}, abstract = {The endosymbiosis between dinoflagellate algae of the genus Symbiodinium and stony corals provides the foundation of coral reef ecosystems. Coral bleaching, the expulsion of endosymbionts from the coral host tissue as a consequence of heat or light stress, poses a threat to reef ecosystem functioning on a global scale. Hence, a better understanding of the factors contributing to heat stress susceptibility and tolerance is needed. In this regard, some of the most thermotolerant corals live in particularly saline habitats, but possible effects of high salinity on thermotolerance in corals are anecdotal. Here we test the hypothesis that high salinity may lead to increased thermotolerance. We conducted a heat stress experiment at low, intermediate, and high salinities using a set of host-endosymbiont combinations of the coral model Aiptasia. As expected, all host-endosymbiont combinations showed reduced photosynthetic efficiency and endosymbiont loss during heat stress, but the severity of bleaching was significantly reduced with increasing salinities for one of the host-endosymbiont combinations. Our results show that higher salinities can convey increased thermotolerance in Aiptasia, although this effect seems to be dependent on the particular host strain and/or associated symbiont type. This finding may help explain the extraordinarily high thermotolerance of corals in high salinity environments, such as the Red Sea and the Persian/Arabian Gulf, and provides novel insight regarding factors that contribute to thermotolerance. Since our results are based on a salinity effect in symbiotic sea anemones, it remains to be determined whether this salinity effect can also be observed in stony corals.}, }
@article {pmid29174886, year = {2017}, author = {Janouškovec, J and Tikhonenkov, DV and Burki, F and Howe, AT and Rohwer, FL and Mylnikov, AP and Keeling, PJ}, title = {A New Lineage of Eukaryotes Illuminates Early Mitochondrial Genome Reduction.}, journal = {Current biology : CB}, volume = {27}, number = {23}, pages = {3717-3724.e5}, doi = {10.1016/j.cub.2017.10.051}, pmid = {29174886}, issn = {1879-0445}, mesh = {Alveolata/classification/*genetics ; *Evolution, Molecular ; *Genome, Mitochondrial ; Phylogeny ; }, abstract = {The origin of eukaryotic cells represents a key transition in cellular evolution and is closely tied to outstanding questions about mitochondrial endosymbiosis [1, 2]. For example, gene-rich mitochondrial genomes are thought to be indicative of an ancient divergence, but this relies on unexamined assumptions about endosymbiont-to-host gene transfer [3-5]. Here, we characterize Ancoracysta twista, a new predatory flagellate that is not closely related to any known lineage in 201-protein phylogenomic trees and has a unique morphology, including a novel type of extrusome (ancoracyst). The Ancoracysta mitochondrion has a gene-rich genome with a coding capacity exceeding that of all other eukaryotes except the distantly related jakobids and Diphylleia, and it uniquely possesses heterologous, nucleus-, and mitochondrion-encoded cytochrome c maturase systems. To comprehensively examine mitochondrial genome reduction, we also assembled mitochondrial genomes from picozoans and colponemids and re-annotated existing mitochondrial genomes using hidden Markov model gene profiles. This revealed over a dozen previously overlooked mitochondrial genes at the level of eukaryotic supergroups. Analysis of trends over evolutionary time demonstrates that gene transfer to the nucleus was non-linear, that it occurred in waves of exponential decrease, and that much of it took place comparatively early, massively independently, and with lineage-specific rates. This process has led to differential gene retention, suggesting that gene-rich mitochondrial genomes are not a product of their early divergence. Parallel transfer of mitochondrial genes and their functional replacement by new nuclear factors are important in models for the origin of eukaryotes, especially as major gaps in our knowledge of eukaryotic diversity at the deepest level remain unfilled.}, }
@article {pmid29169377, year = {2017}, author = {Pagès, N and Muñoz-Muñoz, F and Verdún, M and Pujol, N and Talavera, S}, title = {First detection of Wolbachia-infected Culicoides (Diptera: Ceratopogonidae) in Europe: Wolbachia and Cardinium infection across Culicoides communities revealed in Spain.}, journal = {Parasites &amp; vectors}, volume = {10}, number = {1}, pages = {582}, pmid = {29169377}, issn = {1756-3305}, mesh = {Animals ; Bacterial Infections/*epidemiology/microbiology ; Bacteroidetes/genetics/*isolation &amp; purification ; Bluetongue/transmission ; Ceratopogonidae/classification/*microbiology ; Disease Vectors ; Europe/epidemiology ; Gram-Negative Bacterial Infections/epidemiology/microbiology ; Insect Control ; Insect Vectors/*microbiology ; Prevalence ; Spain/epidemiology ; Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {BACKGROUND: Biting midges of the genus Culicoides (Diptera: Ceratopogonidae) transmit pathogens that cause important diseases. No effective technique has been found to properly control either Culicoides spp. abundance or their likelihood to transmit pathogens. Endosymbionts, particularly Wolbachia, represent powerful alternatives to control arthropods of health interest. In arthropods, Wolbachia can reduce vector fitness and vector's pathogen transmission capacity, thus being a potential target for population reduction and replacement strategies.<br><br>RESULTS: The presence of Wolbachia and Cardinium endosymbionts was screened in Spanish Culicoides spp. populations at livestock premises and natural habitats. The first detection of Wolbachia-infected Culicoides spp. in Europe is reported. The putative Palaearctic vectors for bluetongue and Schmallenberg diseases, C. imicola, C. obsoletus (s.s.) and C. pulicaris (s.l.), were infected with Wolbachia. Four genetic clusters of closely-related Wolbachia strains from A and B supergroups were detected infecting Culicoides. Cardinium strain of the C-group was detected in C. obsoletus (s.l.). Both endosymbionts, Wolbachia and Cardinium, were detected in Culicoides species of minor epidemiological relevance as well. Higher prevalence of Wolbachia infection was detected in natural habitats, while livestock premises lead to higher prevalence of Cardinium. Significant differences in the prevalence of Wolbachia, but not Cardinium, were also detected between some Culicoides species and between locations.<br><br>CONCLUSIONS: The presence of Wolbachia and Cardinium endosymbionts in Culicoides is expected to trigger new research towards the control of Culicoides-transmitted diseases. The results of the present study could have an impact beyond the Culicoides arena because successful Wolbachia transfection is possible even across genus and species barriers.}, }
@article {pmid29165845, year = {2018}, author = {Audsley, MD and Seleznev, A and Joubert, DA and Woolfit, M and O'Neill, SL and McGraw, EA}, title = {Wolbachia infection alters the relative abundance of resident bacteria in adult Aedes aegypti mosquitoes, but not larvae.}, journal = {Molecular ecology}, volume = {27}, number = {1}, pages = {297-309}, doi = {10.1111/mec.14436}, pmid = {29165845}, issn = {1365-294X}, mesh = {Aedes/*microbiology ; Animals ; Australia ; Biodiversity ; Female ; Genes, Bacterial ; High-Throughput Nucleotide Sequencing ; Larva/microbiology ; Microbiota/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Wolbachia/classification/*physiology ; }, abstract = {Insect-symbiont interactions are known to play key roles in host functions and fitness. The common insect endosymbiont Wolbachia can reduce the ability of several human pathogens, including arboviruses and the malaria parasite, to replicate in insect hosts. Wolbachia does not naturally infect Aedes aegypti, the primary vector of dengue virus, but transinfected Ae. aegypti have antidengue virus properties and are currently being trialled as a dengue biocontrol strategy. Here, we assess the impact of Wolbachia infection of Ae. aegypti on the microbiome of wild mosquito populations (adults and larvae) collected from release sites in Cairns, Australia, by profiling the 16S rRNA gene using next-generation sequencing. Our data indicate that Wolbachia reduces the relative abundance of a large proportion of bacterial taxa in Ae. aegypti adults, that is in accordance with the known pathogen-blocking effects of Wolbachia on a variety of bacteria and viruses. In adults, several of the most abundant bacterial genera were found to undergo significant shifts in relative abundance. However, the genera showing the greatest changes in relative abundance in Wolbachia-infected adults represented a low proportion of the total microbiome. In addition, there was little effect of Wolbachia infection on the relative abundance of bacterial taxa in larvae, or on species diversity (accounting for species richness and evenness together) detected in adults or larvae. These results offer insight into the effects of Wolbachia on the Ae. aegypti microbiome in a native setting, an important consideration for field releases of Wolbachia into the population.}, }
@article {pmid29163404, year = {2017}, author = {Malik, SS and Azem-E-Zahra, S and Kim, KM and Caetano-Anollés, G and Nasir, A}, title = {Do Viruses Exchange Genes across Superkingdoms of Life?.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {2110}, pmid = {29163404}, issn = {1664-302X}, abstract = {Viruses can be classified into archaeoviruses, bacterioviruses, and eukaryoviruses according to the taxonomy of the infected host. The host-constrained perception of viruses implies preference of genetic exchange between viruses and cellular organisms of their host superkingdoms and viral origins from host cells either via escape or reduction. However, viruses frequently establish non-lytic interactions with organisms and endogenize into the genomes of bacterial endosymbionts that reside in eukaryotic cells. Such interactions create opportunities for genetic exchange between viruses and organisms of non-host superkingdoms. Here, we take an atypical approach to revisit virus-cell interactions by first identifying protein fold structures in the proteomes of archaeoviruses, bacterioviruses, and eukaryoviruses and second by tracing their spread in the proteomes of superkingdoms Archaea, Bacteria, and Eukarya. The exercise quantified protein structural homologies between viruses and organisms of their host and non-host superkingdoms and revealed likely candidates for virus-to-cell and cell-to-virus gene transfers. Unexpected lifestyle-driven genetic affiliations between bacterioviruses and Eukarya and eukaryoviruses and Bacteria were also predicted in addition to a large cohort of protein folds that were universally shared by viral and cellular proteomes and virus-specific protein folds not detected in cellular proteomes. These protein folds provide unique insights into viral origins and evolution that are generally difficult to recover with traditional sequence alignment-dependent evolutionary analyses owing to the fast mutation rates of viral gene sequences.}, }
@article {pmid29160361, year = {2018}, author = {Almeida, RP and Stouthamer, R}, title = {Phylogeny of the Trichogramma endosymbiont Wolbachia, an alpha-proteobacteria (Rickettsiae).}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {78}, number = {3}, pages = {421-428}, doi = {10.1590/1519-6984.166671}, pmid = {29160361}, issn = {1678-4375}, mesh = {Alphaproteobacteria/*metabolism ; Animals ; Bacterial Outer Membrane Proteins/*metabolism ; DNA Primers/*genetics ; Female ; Genes, Bacterial/*genetics ; Phylogeny ; Reproduction ; Species Specificity ; Symbiosis ; Wasps/genetics/*microbiology ; Wolbachia/*genetics ; }, abstract = {Wolbachia (Hertig) endosymbionts are extensively studied in a wide range of organisms and are known to be transmitted through the egg cytoplasm to the offsping. Wolbachia may cause several types of reproductive modifications in arthropods. In Trichogramma species, parthenogenesis-inducing Wolbachia bacteria allow females wasps to produce daughters from unfertilized eggs and these bacteria are present in at least 9% of all Trichogramma species. Phylogenetic studies have led to the subdivision of the Wolbachia clade in five supergroups (A, B, C, D and E) and Wolbachia from Trichogramma belong to supergroup B. Here, using the wsp gene, four groups of Wolbachia that infect Trichogramma species were distinguished and the addition of a new group "Ato" was suggested due to the addition of Wolbachia from Trichogramma atopovirilia (Oatman and Platner). Specific primers were designed and tested for the "Ato" group. Seventy-five percent of all evaluated Wolbachia strains from Trichogramma fell within "Sib" group.}, }
@article {pmid29155472, year = {2018}, author = {Wang, D and Gu, J and David, R and Wang, Z and Yang, S and Searle, IR and Zhu, JK and Timmis, JN}, title = {Experimental reconstruction of double-stranded break repair-mediated plastid DNA insertion into the tobacco nucleus.}, journal = {The Plant journal : for cell and molecular biology}, volume = {93}, number = {2}, pages = {227-234}, doi = {10.1111/tpj.13769}, pmid = {29155472}, issn = {1365-313X}, mesh = {Cell Nucleus/genetics ; *DNA Breaks, Double-Stranded ; *DNA Repair ; DNA, Chloroplast/genetics ; Genome, Plant/*genetics ; Plastids/genetics ; Symbiosis ; Tobacco/*genetics ; }, abstract = {The mitochondria and plastids of eukaryotic cells evolved from endosymbiotic prokaryotes. DNA from the endosymbionts has bombarded nuclei since the ancestral prokaryotes were engulfed by a precursor of the nucleated eukaryotic host. An experimental confirmation regarding the molecular mechanisms responsible for organelle DNA incorporation into nuclei has not been performed until the present analysis. Here we introduced double-stranded DNA breaks into the nuclear genome of tobacco through inducible expression of I-SceI, and showed experimentally that tobacco chloroplast DNAs insert into nuclear genomes through double-stranded DNA break repair. Microhomology-mediated linking of disparate segments of chloroplast DNA occurs frequently during healing of induced nuclear double-stranded breaks (DSB) but the resulting nuclear integrants are often immediately unstable. Non-Mendelian inheritance of a selectable marker (neo), used to identify plastid DNA transfer, was observed in the progeny of about 50% of lines emerging from the screen. The instability of these de novo nuclear insertions of plastid DNA (nupts) was shown to be associated with deletion not only of the nupt itself but also of flanking nuclear DNA within one generation of transfer. This deletion of pre-existing nuclear DNA suggests that the genetic impact of organellar DNA transfer to the nucleus is potentially far greater than previously thought.}, }
@article {pmid29154755, year = {2017}, author = {Schavemaker, PE and Śmigiel, WM and Poolman, B}, title = {Ribosome surface properties may impose limits on the nature of the cytoplasmic proteome.}, journal = {eLife}, volume = {6}, number = {}, pages = {}, pmid = {29154755}, issn = {2050-084X}, mesh = {Cytoplasm/*metabolism ; Cytosol/metabolism ; Diffusion ; Escherichia coli/*metabolism ; Fluorescent Antibody Technique ; Green Fluorescent Proteins/metabolism ; Haloferax volcanii/*metabolism ; Lactococcus lactis/*metabolism ; Protein Biosynthesis ; Proteome/*metabolism ; Ribosomes/chemistry/genetics/*metabolism ; Surface Properties ; }, abstract = {Much of the molecular motion in the cytoplasm is diffusive, which possibly limits the tempo of processes. We studied the dependence of protein mobility on protein surface properties and ionic strength. We used surface-modified fluorescent proteins (FPs) and determined their translational diffusion coefficients (D) in the cytoplasm of Escherichia coli, Lactococcus lactis and Haloferax volcanii. We find that in E. coli D depends on the net charge and its distribution over the protein, with positive proteins diffusing up to 100-fold slower than negative ones. This effect is weaker in L. lactis and Hfx. volcanii due to electrostatic screening. The decrease in mobility is probably caused by interaction of positive FPs with ribosomes as shown in in vivo diffusion measurements and confirmed in vitro with purified ribosomes. Ribosome surface properties may thus limit the composition of the cytoplasmic proteome. This finding lays bare a paradox in the functioning of prokaryotic (endo)symbionts.}, }
@article {pmid29153324, year = {2017}, author = {Hartmann, AC and Baird, AH and Knowlton, N and Huang, D}, title = {The Paradox of Environmental Symbiont Acquisition in Obligate Mutualisms.}, journal = {Current biology : CB}, volume = {27}, number = {23}, pages = {3711-3716.e3}, doi = {10.1016/j.cub.2017.10.036}, pmid = {29153324}, issn = {1879-0445}, mesh = {Animals ; Anthozoa/*physiology ; Biological Evolution ; Dinoflagellida/*physiology ; *Symbiosis ; }, abstract = {Mutually beneficial interactions between species (mutualisms) shaped the evolution of eukaryotes and remain critical to the survival of species globally [1, 2]. Theory predicts that hosts should pass mutualist symbionts to their offspring (vertical transmission) [3-8]. However, offspring acquire symbionts from the environment in a surprising number of species (horizontal acquisition) [9-12]. A classic example of this paradox is the reef-building corals, in which 71% of species horizontally acquire algal endosymbionts [9]. An untested hypothesis explaining this paradox suggests that horizontal acquisition allows offspring to avoid symbiont-induced harm early in life. We reconstructed the evolution of symbiont transmission across 252 coral species and detected evolutionary transitions consistent with costs of vertical transmission among broadcast spawners, whose eggs tend to be positively buoyant and aggregate at the sea surface. Broadcasters with vertical transmission produce eggs with traits that favor reduced buoyancy (less wax ester lipid) and rapid development to the swimming stage (small egg size), both of which decrease the amount of time offspring spend at the sea surface. Wax ester provisioning decreased after vertically transmitting species evolved brooding from broadcasting, indicating that reduced buoyancy evolves only when offspring bear symbionts. We conclude that horizontal acquisition protects offspring from damage caused by high light and temperatures near the sea surface while providing benefits from enhanced fertilization and outcrossing. These findings help explain why modes of symbiont transmission and reproduction are strongly associated in corals and highlight benefits of delaying mutualist partnerships, offering an additional hypothesis for the pervasiveness of this theoretically paradoxical strategy.}, }
@article {pmid29150386, year = {2018}, author = {Eleftherianos, I and Yadav, S and Kenney, E and Cooper, D and Ozakman, Y and Patrnogic, J}, title = {Role of Endosymbionts in Insect-Parasitic Nematode Interactions.}, journal = {Trends in parasitology}, volume = {34}, number = {5}, pages = {430-444}, doi = {10.1016/j.pt.2017.10.004}, pmid = {29150386}, issn = {1471-5007}, mesh = {Animals ; Host-Parasite Interactions/*physiology ; Insecta/immunology/*parasitology ; Nematoda/*physiology ; *Symbiosis ; }, abstract = {Endosymbiotic bacteria exist in many animals where they develop relationships that affect certain physiological processes in the host. Insects and their nematode parasites form great models for understanding the genetic and molecular basis of immune and parasitic processes. Both organisms contain endosymbionts that possess the ability to interfere with certain mechanisms of immune function and pathogenicity. This review summarizes recent information on the involvement of insect endosymbionts in the response to parasitic nematode infections, and the influence of nematode endosymbionts on specific aspects of the insect immune system. Analyzing this information will be particularly useful for devising endosymbiont-based strategies to intervene in insect immunity or nematode parasitism for the efficient management of noxious insects in the field.}, }
@article {pmid29145606, year = {2017}, author = {Sato, N and Awai, K}, title = {"Prokaryotic Pathway" Is Not Prokaryotic: Noncyanobacterial Origin of the Chloroplast Lipid Biosynthetic Pathway Revealed by Comprehensive Phylogenomic Analysis.}, journal = {Genome biology and evolution}, volume = {9}, number = {11}, pages = {3162-3178}, pmid = {29145606}, issn = {1759-6653}, mesh = {Acyltransferases/genetics ; *Biosynthetic Pathways ; Chloroplasts/genetics/metabolism ; Cyanobacteria/cytology/genetics ; Endoplasmic Reticulum/metabolism ; Eukaryota/classification/cytology/genetics/metabolism ; Lipids/*biosynthesis ; Photosynthesis ; Phylogeny ; Prokaryotic Cells/*metabolism ; }, abstract = {Lipid biosynthesis within the chloroplast, or more generally plastids, was conventionally called "prokaryotic pathway," which produces glycerolipids bearing C18 acids at the sn-1 position and C16 acids at the sn-2 position, as in cyanobacteria such as Anabaena and Synechocystis. This positional specificity is determined during the synthesis of phosphatidate, which is a precursor to diacylglycerol, the acceptor of galactose for the synthesis of galactolipids. The first acylation at sn-1 is catalyzed by glycerol-3-phosphate acyltransferase (GPAT or GPT), whereas the second acylation at sn-2 is performed by lysophosphatidate acyltransferase (LPAAT, AGPAT, or PlsC). Here we present comprehensive phylogenomic analysis of the origins of various acyltransferases involved in the synthesis of phosphatidate, as well as phosphatidate phosphatases in the chloroplasts. The results showed that the enzymes involved in the two steps of acylation in cyanobacteria and chloroplasts are entirely phylogenetically unrelated despite a previous report stating that the chloroplast LPAAT (ATS2) and cyanobacterial PlsC were sister groups. Phosphatidate phosphatases were separated into eukaryotic and prokaryotic clades, and the chloroplast enzymes were not of cyanobacterial origin, in contrast with another previous report. These results indicate that the lipid biosynthetic pathway in the chloroplasts or plastids did not originate from the cyanobacterial endosymbiont and is not "prokaryotic" in the context of endosymbiotic theory of plastid origin. This is another line of evidence for the discontinuity of plastids and cyanobacteria, which has been suggested in the glycolipid biosynthesis.}, }
@article {pmid29143657, year = {2017}, author = {Nelson, CT and Myrick, ES and Nelson, TA}, title = {Clinical benefits of incorporating doxycycline into a canine heartworm treatment protocol.}, journal = {Parasites &amp; vectors}, volume = {10}, number = {Suppl 2}, pages = {515}, pmid = {29143657}, issn = {1756-3305}, mesh = {Animals ; Anti-Bacterial Agents/*administration &amp; dosage ; Clinical Protocols ; Dirofilaria immitis/drug effects/physiology ; Dirofilariasis/*drug therapy/parasitology ; Dog Diseases/*drug therapy/parasitology ; Dogs ; Female ; Filaricides/*administration &amp; dosage ; Ivermectin/administration &amp; dosage ; Male ; Wolbachia/*drug effects/physiology ; }, abstract = {BACKGROUND: The objective of heartworm treatment is to improve the clinical condition of the patient and to eliminate pre-cardiac, juvenile, and adult worm stages with minimal complications. Pulmonary thromboembolisms are an inevitable consequence of worm death and can result in severe pulmonary reactions and even death of the patient. To minimize these reactions, various treatment protocols involving melarsomine, the only adulticidal drug approved by the US Food and Drug Administrations (FDA), in conjunction with macrocyclic lactone heartworm preventives and glucocorticosteroids have been advocated. The discovery of the bacterial endosymbiont Wolbachia in Dirofilaria immitis has led to several experimental studies examining the effects of administering doxycycline to reduce or eliminate Wolbachia organism. These studies have shown a decrease in gross and microscopic pathology of pulmonary parenchyma in experimental heartworm infections pretreated with doxycycline before melarsomine administration.<br><br>METHODS: Electronic medical records from a large veterinary practice in northeast Alabama were searched to identify dogs treated for heartworms with melarsomine from January 2005 through December 2012. The search was refined further to select for dogs that met the following criteria: 1) received two or three doses of ivermectin heartworm preventive prior to melarsomine injections, 2) received one injection of melarsomine followed by two injections 4 to 8&#xa0;weeks later, and 3) were treated with prednisone following melarsomine injections. The dogs were then divided into those that also were treated with doxycycline 10&#xa0;mg/kg BID for 4&#xa0;weeks (Group A, n&#xa0;=&#xa0;47) and those that did not receive doxycycline (Group B, n&#xa0;=&#xa0;47). The medical notes of all 94 cases were then reviewed for comments concerning coughing, dyspnea, or hemoptysis in the history, physical exam template, or from telephone conversations with clients the week following each visit. Any dog that died within one year of treatment from either cardiovascular or pulmonary problems was noted.<br><br>RESULTS: Dogs from Group A receiving doxycycline had fewer respiratory complications (6.52%) and heartworm disease-related deaths (0%) than Group B (19.14% and 4.25%, respectively).<br><br>CONCLUSIONS: Although there are not enough cases to indicate statistical significance, the results strongly suggest that including doxycycline into canine heartworm treatment protocols decreases post-treatment complications and mortality in naturally infected clinical cases.}, }
@article {pmid29141766, year = {2018}, author = {Sarwar, MS and Jahan, N and Shahbaz, F}, title = {Molecular Detection and Characterization of Wolbachia pipientis from Culex quinquefasciatus Collected from Lahore, Pakistan.}, journal = {The American journal of tropical medicine and hygiene}, volume = {98}, number = {1}, pages = {154-161}, pmid = {29141766}, issn = {1476-1645}, mesh = {Animals ; Culex/*microbiology ; DNA, Bacterial/genetics ; Electrophoresis, Agar Gel ; Female ; Male ; Ovary/microbiology ; Pakistan ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Wolbachia/*genetics ; }, abstract = {The gram-negative, pleomorphic endosymbiont Wolbachia is known to infect a large number of insects and other arthropods naturally. This bacterium modifies the host biology, mainly causing reproductive alterations including feminization, death of male, parthenogenesis, and importantly cytoplasmic incompatibility. Wolbachia-induced cytoplasmic incompatibility results in nonviable offspring and vector population suppression. In addition, this bacterium rapidly spreads and propagates within the host population. This study is the first report on Wolbachia detection and characterization from Culex quinquefasciatus collected from Lahore, Pakistan. For this purpose, mosquito adults were collected from different localities of Lahore and identified at the species level. A total of 145 pairs of ovaries were individually subjected to DNA isolation, and polymerase chain reaction amplification of three (wsp, 16S rRNA, and ftsZ) genes were investigated. In all, 128 females were found positive, representing 82.3% infection rate. The phylogenetic analysis indicated that the detected endosymbiont had 100% homology with Wolbachia pipientis wPip strain and supergroup B. The detection of the local strain of Wolbachia (wPip) will be useful in investigating its potential for the control of dengue vector (Aedes aegypti) and reducing dengue transmission in Pakistan.}, }
@article {pmid29134727, year = {2018}, author = {Thairu, MW and Cheng, S and Hansen, AK}, title = {A sRNA in a reduced mutualistic symbiont genome regulates its own gene expression.}, journal = {Molecular ecology}, volume = {27}, number = {8}, pages = {1766-1776}, doi = {10.1111/mec.14424}, pmid = {29134727}, issn = {1365-294X}, mesh = {Animals ; Aphids/genetics/microbiology ; Buchnera/*genetics ; *Evolution, Molecular ; Gene Expression Regulation/genetics ; Genome, Bacterial/genetics ; *Proteomics ; RNA/genetics ; RNA, Messenger/genetics ; Symbiosis/*genetics ; }, abstract = {Similar to other nutritional endosymbionts that are obligate for host survival, the mutualistic aphid endosymbiont, Buchnera, has a highly reduced genome with few regulatory elements. Until recently, it was thought that aphid hosts were primarily responsible for regulating their symbiotic relationship. However, we recently revealed that Buchnera displays differential protein regulation, but not mRNA expression. We also identified a number of conserved small RNAs (sRNAs) that are expressed among Buchnera taxa. In this study, we investigate whether differential protein regulation in Buchnera is the result of post-transcriptional gene regulation via sRNAs. We characterize the sRNA profile of two Buchnera life stages: (i) when Buchnera is transitioning from an extracellular proliferating state in aphid embryos and (ii) when Buchnera is in an intracellular nonproliferating state in aphid bacteriocytes (specialized symbiont cells). Overall, we identified 90 differentially expressed sRNAs, 97% of which were upregulated in aphid embryos. Of these sRNAs, the majority were predicted to be involved in the regulation of various metabolic processes, including arginine biosynthesis. Using a heterologous dual expression vector, we reveal for the first time that a Buchnera antisense sRNA can post-transcriptionally interact with its cognate Buchnera coding sequence, carB, a gene involved in arginine biosynthesis. These results corroborate our in vivo RNAseq and proteomic data, where the candidate antisense sRNA carB and the protein CarB are significantly upregulated in aphid embryos. Overall, we demonstrate that Buchnera may regulate gene expression independently from its host by utilizing sRNAs.}, }
@article {pmid29129532, year = {2017}, author = {Campbell, MA and Łukasik, P and Simon, C and McCutcheon, JP}, title = {Idiosyncratic Genome Degradation in a Bacterial Endosymbiont of Periodical Cicadas.}, journal = {Current biology : CB}, volume = {27}, number = {22}, pages = {3568-3575.e3}, pmid = {29129532}, issn = {1879-0445}, support = {NNA17BB05A/ImNASA/Intramural NASA/United States ; }, mesh = {Animals ; Bacteria/genetics ; Biological Evolution ; DNA, Circular/genetics ; Genome, Bacterial ; Genomics ; Hemiptera/*genetics/*microbiology ; Phylogeny ; Sequence Analysis, DNA/methods ; Symbiosis/*genetics ; }, abstract = {When a free-living bacterium transitions to a host-beneficial endosymbiotic lifestyle, it almost invariably loses a large fraction of its genome [1, 2]. The resulting small genomes often become stable in size, structure, and coding capacity [3-5], as exemplified by Sulcia muelleri, a nutritional endosymbiont of cicadas. Sulcia's partner endosymbiont, Hodgkinia cicadicola, similarly remains co-linear in some cicadas diverged by millions of years [6, 7]. But in the long-lived periodical cicada Magicicada tredecim, the Hodgkinia genome has split into dozens of tiny, gene-sparse circles that sometimes reside in distinct Hodgkinia cells [8]. Previous data suggested that all other Magicicada species harbor complex Hodgkinia populations, but the timing, number of origins, and outcomes of the splitting process were unknown. Here, by sequencing Hodgkinia metagenomes from the remaining six Magicicada and two sister species, we show that each Magicicada species harbors Hodgkinia populations of at least 20 genomic circles. We find little synteny among the 256 Hodgkinia circles analyzed except between the most closely related cicada species. Gene phylogenies show multiple Hodgkinia lineages in the common ancestor of Magicicada and its closest known relatives but that most splitting has occurred within Magicicada and has given rise to highly variable Hodgkinia gene dosages among species. These data show that Hodgkinia genome degradation has proceeded down different paths in different Magicicada species and support a model of genomic degradation that is stochastic in outcome and nonadaptive for the host. These patterns mirror the genomic instability seen in some mitochondria.}, }
@article {pmid29122865, year = {2017}, author = {Fisch, KM and Silva Pereira, C and Genilloud, O and Almeida, C and Schäberle, TF}, title = {Draft Genome Sequence of Burkholderia contaminans 293K04B, an Endosymbiont of the Sponge-Derived Fungus Stachylidium bicolor.}, journal = {Genome announcements}, volume = {5}, number = {45}, pages = {}, pmid = {29122865}, issn = {2169-8287}, abstract = {Here, we present the draft genome of the endofungal symbiotic bacterium Burkholderia contaminans 293K04B, isolated from Stachylidium bicolor 293K04 (Ascomycota). The fungus was originally isolated from the sponge Callyspongia cf. C. flammeaS. bicolor 293K04 produces the endolides A-B, bioactive cyclic peptides possibly biosynthesized by its endobacterium B. contaminans 293K04B.}, }
@article {pmid29119316, year = {2018}, author = {Grigorescu, AS and Renoz, F and Sabri, A and Foray, V and Hance, T and Thonart, P}, title = {Accessing the Hidden Microbial Diversity of Aphids: an Illustration of How Culture-Dependent Methods Can Be Used to Decipher the Insect Microbiota.}, journal = {Microbial ecology}, volume = {75}, number = {4}, pages = {1035-1048}, pmid = {29119316}, issn = {1432-184X}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/classification/genetics/growth &amp; development/*isolation &amp; purification ; *Biodiversity ; Culture Techniques/*methods ; DNA/isolation &amp; purification ; Fungi/classification/genetics/growth &amp; development/*isolation &amp; purification ; Genes, Bacterial/genetics ; Genes, Fungal/genetics ; High-Throughput Nucleotide Sequencing ; Microbiota/genetics/*physiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Serratia/classification/isolation &amp; purification/physiology ; Symbiosis ; }, abstract = {Microorganism communities that live inside insects can play critical roles in host development, nutrition, immunity, physiology, and behavior. Over the past decade, high-throughput sequencing reveals the extraordinary microbial diversity associated with various insect species and provides information independent of our ability to culture these microbes. However, their cultivation in the laboratory remains crucial for a deep understanding of their physiology and the roles they play in host insects. Aphids are insects that received specific attention because of their ability to form symbiotic associations with a wide range of endosymbionts that are considered as the core microbiome of these sap-feeding insects. But, if the functional diversity of obligate and facultative endosymbionts has been extensively studied in aphids, the diversity of gut symbionts and other associated microorganisms received limited consideration. Herein, we present a culture-dependent method that allowed us to successfully isolate microorganisms from several aphid species. The isolated microorganisms were assigned to 24 bacterial genera from the Actinobacteria, Firmicutes, and Proteobacteria phyla and three fungal genera from the Ascomycota and Basidiomycota phyla. In our study, we succeeded in isolating already described bacteria found associated to aphids (e.g., the facultative symbiont Serratia symbiotica), as well as microorganisms that have never been described in aphids before. By unraveling a microbial community that so far has been ignored, our study expands our current knowledge on the microbial diversity associated with aphids and illustrates how fast and simple culture-dependent approaches can be applied to insects in order to capture their diverse microbiota members.}, }
@article {pmid29114401, year = {2017}, author = {Robinson, KM and Hawkins, AS and Santana-Cruz, I and Adkins, RS and Shetty, AC and Nagaraj, S and Sadzewicz, L and Tallon, LJ and Rasko, DA and Fraser, CM and Mahurkar, A and Silva, JC and Dunning Hotopp, JC}, title = {Aligner optimization increases accuracy and decreases compute times in multi-species sequence data.}, journal = {Microbial genomics}, volume = {3}, number = {9}, pages = {e000122}, pmid = {29114401}, issn = {2057-5858}, support = {R01 CA206188/CA/NCI NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/genetics ; Chromosome Mapping ; Data Accuracy ; Databases, Genetic ; Datasets as Topic ; Genome, Human ; High-Throughput Nucleotide Sequencing ; Humans ; Metagenomics ; Plasmodium falciparum/genetics ; Sequence Alignment/*methods ; *Sequence Analysis, DNA ; *Software ; Time Factors ; Wolbachia/genetics ; }, abstract = {As sequencing technologies have evolved, the tools to analyze these sequences have made similar advances. However, for multi-species samples, we observed important and adverse differences in alignment specificity and computation time for bwa- mem (Burrows-Wheeler aligner-maximum exact matches) relative to bwa-aln. Therefore, we sought to optimize bwa-mem for alignment of data from multi-species samples in order to reduce alignment time and increase the specificity of alignments. In the multi-species cases examined, there was one majority member (i.e. Plasmodium falciparum or Brugia malayi) and one minority member (i.e. human or the Wolbachia endosymbiont wBm) of the sequence data. Increasing bwa-mem seed length from the default value reduced the number of read pairs from the majority sequence member that incorrectly aligned to the reference genome of the minority sequence member. Combining both source genomes into a single reference genome increased the specificity of mapping, while also reducing the central processing unit (CPU) time. In Plasmodium, at a seed length of 18 nt, 24.1 % of reads mapped to the human genome using 1.7±0.1 CPU hours, while 83.6 % of reads mapped to the Plasmodium genome using 0.2±0.0 CPU hours (total: 107.7 % reads mapping; in 1.9±0.1 CPU hours). In contrast, 97.1 % of the reads mapped to a combined Plasmodium-human reference in only 0.7±0.0 CPU hours. Overall, the results suggest that combining all references into a single reference database and using a 23 nt seed length reduces the computational time, while maximizing specificity. Similar results were found for simulated sequence reads from a mock metagenomic data set. We found similar improvements to computation time in a publicly available human-only data set.}, }
@article {pmid29112874, year = {2017}, author = {Roger, AJ and Muñoz-Gómez, SA and Kamikawa, R}, title = {The Origin and Diversification of Mitochondria.}, journal = {Current biology : CB}, volume = {27}, number = {21}, pages = {R1177-R1192}, doi = {10.1016/j.cub.2017.09.015}, pmid = {29112874}, issn = {1879-0445}, mesh = {Adenosine Triphosphate/biosynthesis/metabolism ; Alphaproteobacteria/*genetics/growth &amp; development ; *Biological Evolution ; Eukaryotic Cells/*metabolism ; Genome, Mitochondrial/genetics ; Membrane Transport Proteins/genetics ; *Mitochondria/genetics/metabolism/physiology ; Protein Transport/genetics/physiology ; Symbiosis/genetics/physiology ; }, abstract = {Mitochondria are best known for their role in the generation of ATP by aerobic respiration. Yet, research in the past half century has shown that they perform a much larger suite of functions and that these functions can vary substantially among diverse eukaryotic lineages. Despite this diversity, all mitochondria derive from a common ancestral organelle that originated from the integration of an endosymbiotic alphaproteobacterium into a host cell related to Asgard Archaea. The transition from endosymbiotic bacterium to permanent organelle entailed a massive number of evolutionary changes including the origins of hundreds of new genes and a protein import system, insertion of membrane transporters, integration of metabolism and reproduction, genome reduction, endosymbiotic gene transfer, lateral gene transfer and the retargeting of proteins. These changes occurred incrementally as the endosymbiont and the host became integrated. Although many insights into this transition have been gained, controversy persists regarding the nature of the original endosymbiont, its initial interactions with the host and the timing of its integration relative to the origin of other features of eukaryote cells. Since the establishment of the organelle, proteins have been gained, lost, transferred and retargeted as mitochondria have specialized into the spectrum of functional types seen across the eukaryotic tree of life.}, }
@article {pmid29110156, year = {2018}, author = {Medina-Silva, R and Oliveira, RR and Trindade, FJ and Borges, LGA and Lopes Simão, TL and Augustin, AH and Valdez, FP and Constant, MJ and Simundi, CL and Eizirik, E and Groposo, C and Miller, DJ and da Silva, PR and Viana, AR and Ketzer, JMM and Giongo, A}, title = {Microbiota associated with tubes of Escarpia sp. from cold seeps in the southwestern Atlantic Ocean constitutes a community distinct from that of surrounding marine sediment and water.}, journal = {Antonie van Leeuwenhoek}, volume = {111}, number = {4}, pages = {533-550}, doi = {10.1007/s10482-017-0975-7}, pmid = {29110156}, issn = {1572-9699}, mesh = {Animals ; Atlantic Ocean ; Bacteria/*classification ; *Biodiversity ; Chemoautotrophic Growth ; DNA Barcoding, Taxonomic ; Ecosystem ; Geologic Sediments/*microbiology ; Metagenome/genetics ; Microbiota/*physiology ; Planctomycetales ; Polychaeta/*microbiology/ultrastructure ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; }, abstract = {As the depth increases and the light fades in oceanic cold seeps, a variety of chemosynthetic-based benthic communities arise. Previous assessments reported polychaete annelids belonging to the family Siboglinidae as part of the fauna at cold seeps, with the 'Vestimentifera' clade containing specialists that depend on microbial chemosynthetic endosymbionts for nutrition. Little information exists concerning the microbiota of the external portion of the vestimentiferan trunk wall. We employed 16S rDNA-based metabarcoding to describe the external microbiota of the chitin tubes from the vestimentiferan Escarpia collected from a chemosynthetic community in a cold seep area at the southwestern Atlantic Ocean. The most abundant operational taxonomic unit (OTU) belonged to the family Pirellulaceae (phylum Planctomycetes), and the second most abundant OTU belonged to the order Methylococcales (phylum Proteobacteria), composing an average of 21.1 and 15.4% of the total reads on tubes, respectively. These frequencies contrasted with those from the surrounding environment (sediment and water), where they represent no more than 0.1% of the total reads each. Moreover, some taxa with lower abundances were detected only in Escarpia tube walls. These data constitute on the first report of an epibiont microbial community found in close association with external surface of a cold-seep metazoan, Escarpia sp., from a chemosynthetic community in the southwestern Atlantic Ocean.}, }
@article {pmid29104867, year = {2017}, author = {Varela-Stokes, AS and Park, SH and Kim, SA and Ricke, SC}, title = {Microbial Communities in North American Ixodid Ticks of Veterinary and Medical Importance.}, journal = {Frontiers in veterinary science}, volume = {4}, number = {}, pages = {179}, pmid = {29104867}, issn = {2297-1769}, support = {P20 GM103646/GM/NIGMS NIH HHS/United States ; }, abstract = {Interest in microbial communities, or microbiota, of blood-feeding arthropods such as ticks (order Parasitiformes, suborder Ixodida) is increasing. Studies on tick microorganisms historically emphasized pathogens of high medical or veterinary importance. Current techniques allow for simultaneous detection of pathogens of interest, non-pathogenic symbionts, like Coxiella-LE and Francisella-LE, and microorganisms of unknown pathogenic potential. While each generation of ticks begins with a maternally acquired repertoire of microorganisms, microhabitats off and on vertebrate hosts can alter the microbiome during the life cycle. Further, blood-feeding may allow for horizontal exchange of various pathogenic microbiota that may or may not also be capable of vertical transmission. Thus, the tick microbiome may be in constant flux. The geographical spread of tick vector populations has resulted in a broader appreciation of tick-borne diseases and tick-associated microorganisms. Over the last decade, next-generation sequencing technology targeting the 16S rRNA gene led to documented snapshots of bacterial communities among life stages of laboratory and field-collected ticks, ticks in various feeding states, and tick tissues. Characterizing tick bacterial communities at population and individual tissue levels may lead to identification of markers for pathogen maintenance, and thus, indicators of disease "potential" rather than disease state. Defining the role of microbiota within the tick may lead to novel control measures targeting tick-bacterial interactions. Here, we review our current understanding of microbial communities for some vectors in the family Ixodidae (hard ticks) in North America, and interpret published findings for audiences in veterinary and medical fields with an appreciation of tick-borne disease.}, }
@article {pmid29099918, year = {2017}, author = {Chung, M and Small, ST and Serre, D and Zimmerman, PA and Dunning Hotopp, JC}, title = {Draft genome sequence of the Wolbachia endosymbiont of Wuchereria bancrofti wWb.}, journal = {Pathogens and disease}, volume = {75}, number = {9}, pages = {}, pmid = {29099918}, issn = {2049-632X}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; T32 AI007024/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cluster Analysis ; Genes, rRNA ; *Genome, Bacterial ; Open Reading Frames ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; RNA, Ribosomal, 5S/genetics ; *Sequence Analysis, DNA ; Wolbachia/*genetics/isolation &amp; purification ; Wuchereria bancrofti/*microbiology ; }, abstract = {The draft genome assembly of the Wolbachia endosymbiont of Wuchereria bancrofti (wWb) consists of 1060 850 bp in 100 contigs and contains 961 ORFs, with a single copy of the 5S rRNA, 16S rRNA and 23S rRNA and each of the 34 tRNA genes. Phylogenetic core genome analyses show wWb to cluster with other strains in supergroup D of the Wolbachia phylogeny, while being most closely related to the Wolbachia endosymbiont of Brugia malayi strain TRS (wBm). The wWb and wBm genomes share 779 orthologous clusters with wWb having 101 unclustered genes and wBm having 23 unclustered genes. The higher number of unclustered genes in the wWb genome likely reflects the fragmentation of the draft genome.}, }
@article {pmid29093227, year = {2017}, author = {Brandt, JW and Chevignon, G and Oliver, KM and Strand, MR}, title = {Culture of an aphid heritable symbiont demonstrates its direct role in defence against parasitoids.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1866}, pages = {}, pmid = {29093227}, issn = {1471-2954}, mesh = {Animals ; Aphids/*microbiology/*parasitology/virology ; Bacteriophages/physiology ; Enterobacteriaceae/*physiology/virology ; *Host-Parasite Interactions ; Symbiosis ; Wasps/*physiology ; }, abstract = {Heritable symbionts are common in insects with many contributing to host defence. Hamiltonella defensa is a facultative, bacterial symbiont of the pea aphid, Acyrthosiphon pisum that provides protection against the endoparasitoid wasp Aphidius ervi Protection levels vary among strains of H. defensa that are differentially infected by bacteriophages named APSEs. By contrast, little is known about mechanism(s) of resistance owing to the intractability of host-restricted microbes for functional study. Here, we developed methods for culturing strains of H. defensa that varied in the presence and type of APSE. Most H. defensa strains proliferated at 27°C in co-cultures with the TN5 cell line or as pure cultures with no insect cells. The strain infected by APSE3, which provides high levels of protection in vivo, produced a soluble factor(s) that disabled development of A. ervi embryos independent of any aphid factors. Experimental transfer of APSE3 also conferred the ability to disable A. ervi development to a phage-free strain of H. defensa Altogether, these results provide a critical foundation for characterizing symbiont-derived factor(s) involved in host protection and other functions. Our results also demonstrate that phage-mediated transfer of traits provides a mechanism for innovation in host restricted symbionts.}, }
@article {pmid29085996, year = {2018}, author = {Zhang, Y and Su, X and Harris, AJ and Caraballo-Ortiz, MA and Ren, Z and Zhong, Y}, title = {Genetic Structure of the Bacterial Endosymbiont Buchnera aphidicola from Its Host Aphid Schlechtendalia chinensis and Evolutionary Implications.}, journal = {Current microbiology}, volume = {75}, number = {3}, pages = {309-315}, pmid = {29085996}, issn = {1432-0991}, mesh = {Animals ; Aphids/*microbiology/physiology ; Buchnera/classification/*genetics/*isolation &amp; purification/physiology ; China ; DNA, Bacterial/genetics ; *Evolution, Molecular ; Genetic Variation ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Buchnera aphidicola is a primary symbiotic bacterium which provides essential amino acids to aphids. In this study, we sequenced nuclear 16s rDNA and atpAGD genes for 156 individuals of B. aphidicola from eight geographically distant populations to investigate the genetic diversity and structure of B. aphidicola associated to the sumac gall aphid Schlechtendalia chinensis in central and southern China. Our analyses of the combined sequences showed that B. aphidicola from S. chinensis had high haplotype and nucleotide diversity (h = 0.893; π = 0.00164). One of the 16 haplotypes detected had a wide geographic distribution across the central and southern China and was probably the ancestral haplotype of B. aphidicola from S. chinensis. A network and phylogenetic analysis revealed a geographic structure in which the 16 haplotypes of B. aphidicola were divided into the northern and southern clades separated by the Yangtze River. The two clades diverged from each other at 22.1 ± 3.7 Mya according to our divergence time estimations. Therefore, the modern genetic structure in B. aphidicola from S. chinensis has been probably impacted by historical geological events. Combined with the data from GenBank, we also reconstructed the phylogenetic relationships of three aphid subfamilies and their symbiont bacteria. The results indicated significant topological correlations between the aphid and bacterial phylogenies at interspecific levels.}, }
@article {pmid29080766, year = {2017}, author = {Diosdado, A and Gómez, PJ and Morchón, R and Simón, F and González-Miguel, J}, title = {Interaction between Wolbachia and the fibrinolytic system as a possible pathological mechanism in cardiopulmonary dirofilariosis.}, journal = {Veterinary parasitology}, volume = {247}, number = {}, pages = {64-69}, doi = {10.1016/j.vetpar.2017.10.001}, pmid = {29080766}, issn = {1873-2550}, mesh = {Amino Acid Sequence ; Animals ; Dirofilaria immitis/*microbiology ; Dirofilariasis/*parasitology ; Dog Diseases/*parasitology ; Dogs ; Fibrinolysin/metabolism ; Fibrinolysis ; Host-Parasite Interactions ; Humans ; Membrane Proteins/genetics/*metabolism ; Models, Molecular ; Recombinant Proteins ; Sequence Alignment/veterinary ; Symbiosis ; Tissue Plasminogen Activator/*metabolism ; Wolbachia/*physiology ; }, abstract = {Dirofilaria immitis is a mosquito-borne parasite that produces an inflammatory process in the wall of the blood vessels of its definitive host during cardiopulmonary dirofilariosis, known as proliferative endarteritis. Parasite antigens participate in the appearance of this inflammatory event, among other mechanisms through the over-activation of the host fibrinolytic system. Since Wolbachia, endosymbiont bacteria of filarial nematodes, is released into the vertebrate host when worms die, the aim of this work was to analyse the interaction between this bacteria and the host fibrinolytic system to complete the study of this part of the host-parasite relationships. For that purpose, the recombinant form of the major Wolbachia surface protein (rWSP) was cloned, sequenced and expressed and then, its ability to bind plasminogen and enhance the generation of plasmin was assessed. We demonstrated that rWSP is a conserved antigen within the family Onchocercidae with ability to bind plasminogen and stimulate plasmin generation in a tissue-plasminogen activator (t-PA) and lysine residues of the rWSP-dependent manner. These results indicate that the recruitment of plasminogen by Wolbachia and the possible excess of plasmin generated could contribute to exacerbate the pathological events occurred at the vascular level during cardiopulmonary dirofilariosis, as well as in other diseases caused by filarial nematodes that harbour Wolbachia, when the bacteria is released after the death of the worms.}, }
@article {pmid29078351, year = {2017}, author = {Turner, JD and Sharma, R and Al Jayoussi, G and Tyrer, HE and Gamble, J and Hayward, L and Priestley, RS and Murphy, EA and Davies, J and Waterhouse, D and Cook, DAN and Clare, RH and Cassidy, A and Steven, A and Johnston, KL and McCall, J and Ford, L and Hemingway, J and Ward, SA and Taylor, MJ}, title = {Albendazole and antibiotics synergize to deliver short-course anti-Wolbachia curative treatments in preclinical models of filariasis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {45}, pages = {E9712-E9721}, pmid = {29078351}, issn = {1091-6490}, support = {MR/L018756/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Albendazole/*pharmacology ; Animals ; Anti-Bacterial Agents/*pharmacology ; Benzimidazoles/pharmacology ; Brugia malayi/microbiology ; Drug Synergism ; Female ; Filariasis/*drug therapy ; Male ; Mice ; Mice, Inbred BALB C ; Minocycline/pharmacology ; Rifampin/pharmacology ; Wolbachia/*drug effects ; }, abstract = {Elimination of filariasis requires a macrofilaricide treatment that can be delivered within a 7-day period. Here we have identified a synergy between the anthelmintic albendazole (ABZ) and drugs depleting the filarial endosymbiont Wolbachia, a proven macrofilaricide target, which reduces treatment from several weeks to 7 days in preclinical models. ABZ had negligible effects on Wolbachia but synergized with minocycline or rifampicin (RIF) to deplete symbionts, block embryogenesis, and stop microfilariae production. Greater than 99% Wolbachia depletion following 7-day combination of RIF+ABZ also led to accelerated macrofilaricidal activity. Thus, we provide preclinical proof-of-concept of treatment shortening using antibiotic+ABZ combinations to deliver anti-Wolbachia sterilizing and macrofilaricidal effects. Our data are of immediate public health importance as RIF+ABZ are registered drugs and thus immediately implementable to deliver a 1-wk macrofilaricide. They also suggest that novel, more potent anti-Wolbachia drugs under development may be capable of delivering further treatment shortening, to days rather than weeks, if combined with benzimidazoles.}, }
@article {pmid29076805, year = {2018}, author = {Lourenço-de-Oliveira, R and Marques, JT and Sreenu, VB and Atyame Nten, C and Aguiar, ERGR and Varjak, M and Kohl, A and Failloux, AB}, title = {Culex quinquefasciatus mosquitoes do not support replication of Zika virus.}, journal = {The Journal of general virology}, volume = {99}, number = {2}, pages = {258-264}, pmid = {29076805}, issn = {1465-2099}, support = {G0801822/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/12/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; U01 AI115595/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Culex/*virology ; Female ; Mosquito Vectors/*virology ; Phenotype ; *Virus Replication ; Wolbachia/*physiology ; Zika Virus/*physiology ; Zika Virus Infection/*transmission/virology ; }, abstract = {The rapid spread of Zika virus (ZIKV) in the Americas raised many questions about the role of Culex quinquefasciatus mosquitoes in transmission, in addition to the key role played by the vector Aedes aegypti. Here we analysed the competence of Cx. quinquefasciatus (with or without Wolbachia endosymbionts) for a ZIKV isolate. We also examined the induction of RNA interference pathways after viral challenge and the production of small virus-derived RNAs. We did not observe any infection nor such small virus-derived RNAs, regardless of the presence or absence of Wolbachia. Thus, Cx. quinquefasciatus does not support ZIKV replication and Wolbachia is not involved in producing this phenotype. In short, these mosquitoes are very unlikely to play a role in transmission of ZIKV.}, }
@article {pmid29074653, year = {2017}, author = {Ward, CM and Baxter, SW}, title = {Draft Genome Assembly of a Wolbachia Endosymbiont of Plutella australiana.}, journal = {Genome announcements}, volume = {5}, number = {43}, pages = {}, pmid = {29074653}, issn = {2169-8287}, abstract = {Wolbachia spp. are endosymbiotic bacteria that infect around 50% of arthropods and cause a broad range of effects, including manipulating host reproduction. Here, we present the annotated draft genome assembly of Wolbachia strain wAus, which infects Plutella australiana, a cryptic ally of the major Brassica pest Plutella xylostella (diamondback moth).}, }
@article {pmid29071168, year = {2017}, author = {Zhang, L and Zhang, G and Yun, Y and Peng, Y}, title = {Bacterial community of a spider, Marpiss magister (Salticidae).}, journal = {3 Biotech}, volume = {7}, number = {6}, pages = {371}, pmid = {29071168}, issn = {2190-572X}, abstract = {Arthropods are associated with various microorganisms which confer benefits to their hosts. Recently, research has been conducted on bacterial communities of insects to provide an insight into the potential interactions of the symbiotic bacteria and their hosts. Spiders are interesting to study as they are perceived to be natural enemies of pests. The effect of endosymbionts on spiders has been reported, but little is known about the overall bacterial communities present in spiders. Here, we report on the characterization of bacterial communities present in the whole body of the spider Marpiss magister using Illumina sequencing of 16S rRNA amplicons. Our study shows that the most abundant phyla of bacteria included Proteobacteria, Tenericutes, Bacteroidetes and Actinobacteria. At the genus level, the most abundant genera included Rickettsia, Wolbachia, Spiroplasma, and Cardinium. Besides these dominant endosymbionts, our study also showed the existence of bacteria in the genera Arthrobacter, Novosphingobium, Acinetobacter, Pseudomonas, Aquabacterium and Sphingomonas at an abundance ranging from 0.65 to 0.84%, and the existence of bacterial in genera Lactobacillus, Sphingobium, Methylobacterium, Bradyrhizobium, Propionibacterium, Brevundimonas, Achromobacter, Microbacterium, Corynebacterium, and Flavobacterium at a slightly lower abundance ranging from 0.1 to 0.5%. Therefore, our finding indicates that endosymbionts are not the only microbiota present in the spider M. magister, and other bacterial taxa also exist in its bacterial community.}, }
@article {pmid29069333, year = {2017}, author = {Li, YH and Ahmed, MZ and Li, SJ and Lv, N and Shi, PQ and Chen, XS and Qiu, BL}, title = {Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.}, journal = {FEMS microbiology ecology}, volume = {93}, number = {12}, pages = {}, doi = {10.1093/femsec/fix138}, pmid = {29069333}, issn = {1574-6941}, mesh = {Animals ; Female ; Gossypium/*microbiology ; Hemiptera/*microbiology/physiology ; Introduced Species ; Phylogeny ; Plant Leaves/microbiology ; Rickettsia/genetics/isolation &amp; purification/*physiology ; *Symbiosis ; }, abstract = {A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species.}, }
@article {pmid29068466, year = {2017}, author = {Martin, WF}, title = {Too Much Eukaryote LGT.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {39}, number = {12}, pages = {}, doi = {10.1002/bies.201700115}, pmid = {29068466}, issn = {1521-1878}, mesh = {Animals ; Eukaryota/classification/*genetics ; Eukaryotic Cells/cytology/metabolism ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; *Genome ; Mitochondria/genetics ; Phylogeny ; Plants/classification/genetics ; Plastids/genetics ; Prokaryotic Cells/cytology/metabolism ; Symbiosis/*genetics ; }, abstract = {The realization that prokaryotes naturally and frequently disperse genes across steep taxonomic boundaries via lateral gene transfer (LGT) gave wings to the idea that eukaryotes might do the same. Eukaryotes do acquire genes from mitochondria and plastids and they do transfer genes during the process of secondary endosymbiosis, the spread of plastids via eukaryotic algal endosymbionts. From those observations it, however, does not follow that eukaryotes transfer genes either in the same ways as prokaryotes do, or to a quantitatively similar degree. An important illustration of the difference is that eukaryotes do not exhibit pangenomes, though prokaryotes do. Eukaryotes reveal no detectable cumulative effects of LGT, though prokaryotes do. A critical analysis suggests that something is deeply amiss with eukaryote LGT theories.}, }
@article {pmid29066288, year = {2018}, author = {Kretschmann, J and Žerdoner Čalasan, A and Gottschling, M}, title = {Molecular phylogenetics of dinophytes harboring diatoms as endosymbionts (Kryptoperidiniaceae, Peridiniales), with evolutionary interpretations and a focus on the identity of Durinskia oculata from Prague.}, journal = {Molecular phylogenetics and evolution}, volume = {118}, number = {}, pages = {392-402}, doi = {10.1016/j.ympev.2017.10.011}, pmid = {29066288}, issn = {1095-9513}, mesh = {Czech Republic ; Diatoms/*cytology/genetics ; Likelihood Functions ; Phylogeny ; RNA, Ribosomal/chemistry/genetics ; Sequence Analysis, DNA ; }, abstract = {Peridinialean dinophytes include a unique evolutionary group of algae harboring a diatom as an endosymbiont (Kryptoperidiniaceae), whose phylogenetic origin and internal relationships are not fully resolved at present. Several interpretations of the thecal plate pattern present in Durinskia oculata currently compete and lead to considerable taxonomic confusion. Moreover, it is unclear at present whether the species is restricted to freshwater habitats, or occurs in the marine environment as well. We collected material at the type locality of D. oculata in the Czech Republic and established monoclonal strains. Dinophyte cells were studied using light and electron microscopy, and we also determined DNA sequences of several rRNA regions (including the Internal Transcribed Spacers) for molecular characterization and phylogenetics. The morphology of strain GeoM∗662 indicated a plate formula of Po, X, 4', 2a, 6″, 5c, 5s, 5‴, 2⁗, which was sustained also in form of a microscopic slide serving as an epitype. In the molecular DNA tree based on a matrix composed of concatenated rRNA sequences, strain GeoM∗662 showed a close relationship to other species of Durinskia, and the freshwater species clearly differs from the marine members. Two independent colonization events from the marine into the freshwater environment can be inferred within the Kryptoperidiniaceae. We provide a summarizing cladogram of dinophytes harboring a diatom as endosymbiont with evolutionary novelties indicated as well as a morphological key to the 6 species of Durinskia that are currently accepted.}, }
@article {pmid29065795, year = {2017}, author = {Al-Abd, NM and Nor, ZM and Junaid, QO and Mansor, M and Hasan, MS and Kassim, M}, title = {Antifilarial activity of caffeic acid phenethyl ester on Brugia pahangi in vitro and in vivo.}, journal = {Pathogens and global health}, volume = {111}, number = {7}, pages = {388-394}, pmid = {29065795}, issn = {2047-7732}, mesh = {Animals ; Brugia pahangi/*drug effects ; Caffeic Acids/administration &amp; dosage/*therapeutic use ; Dose-Response Relationship, Drug ; Filariasis/*drug therapy/parasitology ; Gerbillinae ; Humans ; Male ; Phenylethyl Alcohol/administration &amp; dosage/*analogs &amp; derivatives/therapeutic use ; Wolbachia/drug effects ; }, abstract = {Lymphatic filariasis (LF) is a vector borne disease caused by parasitic worms such as Wuchereria bancrofti, Brugia malayi and B. timori, which are transmitted by mosquitoes. Current therapeutics to treat LF are mainly microfilarcidal, and lack activity against adult worms. This set back, poses a challenge for the control and elimination of filariasis. Thus, in this study the activities of caffeic acid phenethyl ester (CAPE) against the filarial worm B. pahangi and its bacterial endosymbiont, Wolbachia were evaluated. Different concentrations (2, 5, 10, 15, 20 μg/ml) of CAPE were used to assess its effects on motility, viability and microfilarial (mf) production of B. pahangi in vitro. Anti-Wolbachial activity of CAPE was measured in worms by quantification of Wolbachial wsp gene copy number using real-time polymerase chain reaction. Our findings show that CAPE was found to significantly reduce adult worm motility, viability, and mf release both in vitro and in vivo. 20 μg/ml of CAPE halts the release of mf in vitro by day 6 of post treatment. Also, the number of adult worms recovered in vivo were reduced significantly during and after treatment with 50 mg/kg of CAPE relative to control drugs, diethylcarbamazine and doxycycline. Real time PCR based on the Wolbachia ftsZ gene revealed a significant reduction in Wolbachia copy number upon treatment. Anti-Wolbachia and antifilarial properties of CAPE require further investigation as an alternative strategy to treat LF.}, }
@article {pmid29063344, year = {2018}, author = {Hornok, S and Ágh, N and Takács, N and Kontschán, J and Hofmann-Lehmann, R}, title = {Haematospirillum and insect Wolbachia DNA in avian blood.}, journal = {Antonie van Leeuwenhoek}, volume = {111}, number = {3}, pages = {479-483}, doi = {10.1007/s10482-017-0961-0}, pmid = {29063344}, issn = {1572-9699}, mesh = {Alphaproteobacteria/*genetics ; Animals ; Birds/*blood ; *DNA, Bacterial ; Female ; *Genes, Insect ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Wolbachia/*genetics ; }, abstract = {In this study, blood samples of 259 Acrocephalus sp. warblers were molecularly analysed for Anaplasmataceae and Rhodospirillaceae based on PCR amplification of 16S rRNA gene fragments. One bird blood sample (from Reed Warbler, Acrocephalus scirpaceus) yielded a sequence with 99.8% identity to Haematospirillum jordaniae. This is the first molecular evidence for the occurrence of this species in the blood of any vertebrate other than human. Another bird blood sample (from Marsh Warbler: Acrocephalus palustris) yielded a Wolbachia sequence, closely related to a moth endosymbiont with 99.8% identity. A nematode origin of Wolbachia DNA detected here in avian blood can be excluded, because results of phylogenetic analysis showed its closest alignment with insect wolbachiae. This is the first finding of insect Wolbachia DNA in the circulatory system of birds, which can be explained either by the inoculation of wolbachiae by blood-sucking vectors, or passing of Wolbachia DNA from the gut into the blood of this insectivorous bird species.}, }
@article {pmid29056742, year = {2016}, author = {Kurtti, TJ and Burkhardt, NY and Heu, CC and Munderloh, UG}, title = {Fluorescent Protein Expressing Rickettsia buchneri and Rickettsia peacockii for Tracking Symbiont-Tick Cell Interactions.}, journal = {Veterinary sciences}, volume = {3}, number = {4}, pages = {}, pmid = {29056742}, issn = {2306-7381}, support = {R01 AI042792/AI/NIAID NIH HHS/United States ; R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI081690/AI/NIAID NIH HHS/United States ; }, abstract = {Rickettsiae of indeterminate pathogenicity are widely associated with ticks. The presence of these endosymbionts can confound a One Health approach to combatting tick-borne diseases. Genomic analyses of symbiotic rickettsiae have revealed that they harbor mutations in gene coding for proteins involved in rickettsial pathogenicity and motility. We have isolated and characterized two rickettsial symbionts-Rickettsia peacockii and R. buchneri-both from ticks using tick cell cultures. To better track these enigmatic rickettsiae in ticks and at the tick-mammal interface we transformed the rickettsiae to express fluorescent proteins using shuttle vectors based on rickettsial plasmids or a transposition system driving insertional mutagenesis. Fluorescent protein expressing R. buchneri and R. peacockii will enable us to elucidate their interactions with tick and mammalian cells, and track their location and movement within individual cells, vector ticks, and host animals.}, }
@article {pmid29046673, year = {2017}, author = {Kostygov, AY and Butenko, A and Nenarokova, A and Tashyreva, D and Flegontov, P and Lukeš, J and Yurchenko, V}, title = {Genome of Ca. Pandoraea novymonadis, an Endosymbiotic Bacterium of the Trypanosomatid Novymonas esmeraldas.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {1940}, pmid = {29046673}, issn = {1664-302X}, abstract = {We have sequenced, annotated, and analyzed the genome of Ca. Pandoraea novymonadis, a recently described bacterial endosymbiont of the trypanosomatid Novymonas esmeraldas. When compared with genomes of its free-living relatives, it has all the hallmarks of the endosymbionts' genomes, such as significantly reduced size, extensive gene loss, low GC content, numerous gene rearrangements, and low codon usage bias. In addition, Ca. P. novymonadis lacks mobile elements, has a strikingly low number of pseudogenes, and almost all genes are single copied. This suggests that it already passed the intensive period of host adaptation, which still can be observed in the genome of Polynucleobacter necessarius, a certainly recent endosymbiont. Phylogenetically, Ca. P. novymonadis is more related to P. necessarius, an intracytoplasmic bacterium of free-living ciliates, than to Ca. Kinetoplastibacterium spp., the only other known endosymbionts of trypanosomatid flagellates. As judged by the extent of the overall genome reduction and the loss of particular metabolic abilities correlating with the increasing dependence of the symbiont on its host, Ca. P. novymonadis occupies an intermediate position P. necessarius and Ca. Kinetoplastibacterium spp. We conclude that the relationships between Ca. P. novymonadis and N. esmeraldas are well-established, although not as fine-tuned as in the case of Strigomonadinae and their endosymbionts.}, }
@article {pmid29046583, year = {2017}, author = {Boscaro, V and Kolisko, M and Felletti, M and Vannini, C and Lynn, DH and Keeling, PJ}, title = {Parallel genome reduction in symbionts descended from closely related free-living bacteria.}, journal = {Nature ecology &amp; evolution}, volume = {1}, number = {8}, pages = {1160-1167}, doi = {10.1038/s41559-017-0237-0}, pmid = {29046583}, issn = {2397-334X}, mesh = {Biological Evolution ; Burkholderiaceae/*genetics/physiology ; Euplotes/*microbiology ; *Evolution, Molecular ; *Genome, Bacterial ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Endosymbiosis plays an important role in ecology and evolution, but fundamental aspects of the origin of intracellular symbionts remain unclear. The extreme age of many symbiotic relationships, lack of data on free-living ancestors and uniqueness of each event hinder investigations. Here, we describe multiple strains of the bacterium Polynucleobacter that evolved independently and under similar conditions from closely related, free-living ancestors to become obligate endosymbionts of closely related ciliate hosts. As these genomes reduced in parallel from similar starting states, they provide unique glimpses into the mechanisms underlying genome reduction in symbionts. We found that gene loss is contingently lineage-specific, with no evidence for ordered streamlining. However, some genes in otherwise disrupted pathways are retained, possibly reflecting cryptic genetic network complexity. We also measured substitution rates between many endosymbiotic and free-living pairs for hundreds of genes, which showed that genetic drift, and not mutation pressure, is the main non-selective factor driving molecular evolution in endosymbionts.}, }
@article {pmid29042606, year = {2017}, author = {Signor, S}, title = {Population genomics of Wolbachia and mtDNA in Drosophila simulans from California.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {13369}, pmid = {29042606}, issn = {2045-2322}, mesh = {California ; DNA, Mitochondrial/*genetics ; Drosophila simulans/*microbiology ; Evolution, Molecular ; Gene Dosage ; *Genetics, Population ; *Genomics/methods ; Linkage Disequilibrium ; Phylogeny ; Polymorphism, Single Nucleotide ; Wolbachia/classification/*genetics ; }, abstract = {Wolbachia pipientis is an intracellular endosymbiont infecting many arthropods and filarial nematodes. Little is known about the short-term evolution of Wolbachia or its interaction with its host. Wolbachia is maternally inherited, resulting in co-inheritance of mitochondrial organelles such as mtDNA. Here I explore the evolution of Wolbachia, and the relationship between Wolbachia and mtDNA, using a large inbred panel of Drosophila simulans. I compare this to the only other large population genomic Wolbachia dataset from D. melanogaster. I find reduced diversity relative to expectation in both Wolbachia and mtDNA, but only mtDNA shows evidence of a recent selective sweep or population bottleneck. I estimate Wolbachia and mtDNA titre in each genotype, and I find considerable variation in both phenotypes, despite low genetic diversity in Wolbachia and mtDNA. A phylogeny of Wolbachia and of mtDNA suggest a recent origin of the infection derived from a single origin. Using Wolbachia and mtDNA titre as a phenotype, I perform the first association analysis using this phenotype with the nuclear genome and find several implicated regions, including one which contains four CAAX-box protein processing genes. CAAX-box protein processing can be an important part of host-pathogen interactions in other systems, suggesting interesting directions for future research.}, }
@article {pmid29036401, year = {2017}, author = {Santos-Garcia, D and Silva, FJ and Morin, S and Dettner, K and Kuechler, SM}, title = {The All-Rounder Sodalis: A New Bacteriome-Associated Endosymbiont of the Lygaeoid Bug Henestaris halophilus (Heteroptera: Henestarinae) and a Critical Examination of Its Evolution.}, journal = {Genome biology and evolution}, volume = {9}, number = {10}, pages = {2893-2910}, pmid = {29036401}, issn = {1759-6653}, mesh = {Animals ; DNA, Bacterial ; Databases, Factual ; Enterobacteriaceae/*classification/genetics/*physiology/ultrastructure ; *Evolution, Molecular ; Genome Size ; Genome, Bacterial ; Heteroptera/*microbiology ; Metabolic Networks and Pathways ; *Phylogeny ; Pseudogenes ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Hemipteran insects are well-known in their ability to establish symbiotic relationships with bacteria. Among them, heteropteran insects present an array of symbiotic systems, ranging from the most common gut crypt symbiosis to the more restricted bacteriome-associated endosymbiosis, which have only been detected in members of the superfamily Lygaeoidea and the family Cimicidae so far. Genomic data of heteropteran endosymbionts are scarce and have merely been analyzed from the Wolbachia endosymbiont in bed bug and a few gut crypt-associated symbionts in pentatomoid bugs. In this study, we present the first detailed genomic analysis of a bacteriome-associated endosymbiont of a phytophagous heteropteran, present in the seed bug Henestaris halophilus (Hemiptera: Heteroptera: Lygaeoidea). Using phylogenomics and genomics approaches, we have assigned the newly characterized endosymbiont to the Sodalis genus, named as Candidatus Sodalis baculum sp. nov. strain kilmister. In addition, our findings support the reunification of the Sodalis genus, currently divided into six different genera. We have also conducted comparative analyses between 15 Sodalis species that present different genome sizes and symbiotic relationships. These analyses suggest that Ca. Sodalis baculum is a mutualistic endosymbiont capable of supplying the amino acids tyrosine, lysine, and some cofactors to its host. It has a small genome with pseudogenes but no mobile elements, which indicates middle-stage reductive evolution. Most of the genes in Ca. Sodalis baculum are likely to be evolving under purifying selection with several signals pointing to the retention of the lysine/tyrosine biosynthetic pathways compared with other Sodalis.}, }
@article {pmid29027651, year = {2017}, author = {Cavaleiro, FI and Rangel, LF and Frade, DG and Santos, MJ}, title = {Syndesmis aethopharynx Westervelt &amp; Kozloff, 1990 (Rhabdocoela: Umagillidae): a revisitation supported by scanning electron microscopy and molecular analyses.}, journal = {Systematic parasitology}, volume = {94}, number = {9}, pages = {1007-1017}, pmid = {29027651}, issn = {1573-5192}, mesh = {Animals ; Echinodermata/parasitology ; Microscopy, Electron, Scanning ; *Phylogeny ; Species Specificity ; Turbellaria/*classification/*ultrastructure ; }, abstract = {Species of Syndesmis Francois, 1886 are rhabdocoel platyhelminths typically found in echinoids. Our knowledge of this group is based on old and insufficient studies, generally representing light microscopy-based species descriptions. Syndesmis aethopharynx Westervelt &amp; Kozloff, 1990 is an understudied endosymbiont of Paracentrotus lividus (Lamarck), which is likely to have been confused with the type-species, i.e. Syndesmis echinorum François, 1886, in the literature. In this work, S. aethopharynx is revisited based on new data on surface morphology and phylogeny and basic ecological data are provided. Scanning electron microscopy analysis revealed that the whole ventral region of the worm is equipped with cilia, which supports the assumption that the unciliated epidermal area reported for some species of umagillids, likewise endosymbiotic in echinoderms, is an apomorphy. Following the results of the molecular phylogenetic analysis, species of Syndesmis are closely-related to symbionts of other echinoderms, i.e. holothurians, and like them, may have evolved from some free-living or symbiotic Provorticidae ancestor. Syndesmis spp. may stand for a key group in studying the evolution of feeding strategies in rhabdocoels, as their phylogenetic position is between intestinal and coelomic symbionts, and since both the digestive tube and perivisceral fluid were recorded as sites of infection. The infection levels were low, likely reflecting the aggregated distribution of the host and the fragile nature of the symbiont.}, }
@article {pmid29026213, year = {2017}, author = {Nakayama, T and Inagaki, Y}, title = {Genomic divergence within non-photosynthetic cyanobacterial endosymbionts in rhopalodiacean diatoms.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {13075}, pmid = {29026213}, issn = {2045-2322}, mesh = {Cyanobacteria/classification/*genetics/*physiology ; Diatoms/*microbiology ; Evolution, Molecular ; Genomics ; Phylogeny ; Symbiosis/genetics/*physiology ; }, abstract = {Organelle acquisitions via endosymbioses with prokaryotes were milestones in the evolution of eukaryotes. Still, quite a few uncertainties have remained for the evolution in the early stage of organellogenesis. In this respect, rhopalodiacean diatoms and their obligate cyanobacterial endosymbionts, called spheroid bodies, are emerging as new models for the study of organellogenesis. The genome for the spheroid body of Epithemia turgida, a rhopalodiacean diatom, has unveiled its unique metabolic nature lacking the photosynthetic ability. Nevertheless, the genome sequence of a spheroid body from a single lineage may not be sufficient to depict the evolution of these cyanobacterium-derived intracellular structures as a whole. Here, we report on the complete genome for the spheroid body of Rhopalodia gibberula, a lineage distinct from E. turgida, of which genome has been fully determined. Overall, features in genome structure and metabolic capacity, including a lack of photosynthetic ability, were highly conserved between the two spheroid bodies. However, our comparative genomic analyses revealed that the genome of the R. gibberula spheroid body exhibits a lower non-synonymous substitution rate and a slower progression of pseudogenisation than those of E. turgida, suggesting that a certain degree of diversity exists amongst the genomes of obligate endosymbionts in unicellular eukaryotes.}, }
@article {pmid29022553, year = {2017}, author = {Hahn, MW and Koll, U and Karbon, G and Schmidt, J and Lang, E}, title = {Polynucleobacter aenigmaticus sp. nov. isolated from the permanently anoxic monimolimnion of a temperate meromictic lake.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {67}, number = {11}, pages = {4646-4654}, pmid = {29022553}, issn = {1466-5034}, support = {I 482/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Austria ; Bacterial Typing Techniques ; Burkholderiaceae/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Genes, Bacterial ; Lakes/*microbiology ; Multilocus Sequence Typing ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {The bacterial strain MWH-K35W1[T] was isolated from a permanently anoxic water layer of a meromictic lake located in the Austrian Salzkammergut area. The basically chemo-organoheterotrophic strain was isolated and maintained under aerobic conditions. Phylogenetic analyses of the 16S rRNA gene and the glutamine synthetase gene (glnA) of the strain suggested an affiliation to the genus Polynucleobacter and the cryptic species complex PnecC. Strain MWH-K35W1[T] shares with the type strains of the six free-living species of the genus Polynucleobacter affiliated with this species complex 16S rRNA gene sequence similarities of 99.6-99.9 %, while the type material of the obligate endosymbiont Polynucleobacternecessarius, which is also affiliated with this species complex, shares a gene sequence similarity of 99.1 %. Genome sequencing resulted in a genome size of 2.14 Mbp and a DNA G+C content of 45.98 mol%. Major fatty acids were C16 : 1ω7c, C18 : 1ω7c and C16 : 0. This strain is the first strain of the genus Polynucleobacter found to encode a proteorhodopsin-like protein but, in contrast to some other strains affiliated to this genus, it does not encode a putative anoxygenic photosynthesis system. Multilocus sequence analysis based on partial sequences of eight housekeeping genes, as well as average nucleotide identity (ANI) analyses, did not suggest that strain MWH-K35W1[T] belongs to a previously described species. We propose the name Polynucleobacter aenigmaticus for a novel species with strain MWH-K35W1[T] (=DSM 24006[T]=LMG 29706[T]) as the type strain.}, }
@article {pmid29021316, year = {2017}, author = {Kageyama, D and Yoshimura, K and Sugimoto, TN and Katoh, TK and Watada, M}, title = {Maternally transmitted non-bacterial male killer in Drosophila biauraria.}, journal = {Biology letters}, volume = {13}, number = {10}, pages = {}, pmid = {29021316}, issn = {1744-957X}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Drosophila/*physiology ; Female ; Japan ; Male ; Maternal Inheritance ; Phenotype ; Polymerase Chain Reaction ; Sex Ratio ; Symbiosis ; Tetracycline/pharmacology ; }, abstract = {A maternally inherited, all-female trait is widely found among arthropods, which is caused by bacterial endosymbionts such as Wolbachia, Rickettsia, Spiroplasma and Cardinium We discovered a single female of Drosophila biauraria, collected from Tomakomai, Hokkaido, Japan, that produced all-female offspring. This all-female trait was maternally inherited in the iso-female line (SP12F) by backcrossing with males of a normal line (SP11-20) with a 1 : 1 sex ratio derived from the same population. The all-female trait was not affected by tetracycline treatment performed for two consecutive generations. However, the microinjection of filter-sterilized homogenate of SP12F females into SP11-20 females established all-female matrilines. Our data suggest the role of transmissible agents, most likely viruses, but not bacteria or protists, as the possible cause of the all-female phenotype, which is likely to be achieved by killing of male embryos because egg hatch rates of SP12F were nearly half those of SP11-20. This is the first report in Diptera to demonstrate a maternally inherited virus-like element as the cause of the male-killing phenotype in D. biauraria.}, }
@article {pmid29018596, year = {2017}, author = {Noda, H and Parkinson, JE and Yang, SY and Reimer, JD}, title = {A preliminary survey of zoantharian endosymbionts shows high genetic variation over small geographic scales on Okinawa-jima Island, Japan.}, journal = {PeerJ}, volume = {5}, number = {}, pages = {e3740}, pmid = {29018596}, issn = {2167-8359}, abstract = {Symbiotic dinoflagellates (genus Symbiodinium) shape the responses of their host reef organisms to environmental variability and climate change. To date, the biogeography of Symbiodinium has been investigated primarily through phylogenetic analyses of the ribosomal internal transcribed spacer 2 region. Although the marker can approximate species-level diversity, recent work has demonstrated that faster-evolving genes can resolve otherwise hidden species and population lineages, and that this diversity is often distributed over much finer geographical and environmental scales than previously recognized. Here, we use the noncoding region of the chloroplast psbA gene (psbA[ncr]) to examine genetic diversity among clade C Symbiodinium associating with the common reef zoantharian Palythoa tuberculosa on Okinawa-jima Island, Japan. We identify four closely related Symbiodinium psbA[ncr] lineages including one common generalist and two potential specialists that appear to be associated with particular microhabitats. The sea surface temperature differences that distinguish these habitats are smaller than those usually investigated, suggesting that future biogeographic surveys of Symbiodinium should incorporate fine scale environmental information as well as fine scale molecular data to accurately determine species diversity and their distributions.}, }
@article {pmid28983672, year = {2018}, author = {Wang, D and Huang, Z and He, H and Wei, C}, title = {Comparative analysis of microbial communities associated with bacteriomes, reproductive organs and eggs of the cicada Subpsaltria yangi.}, journal = {Archives of microbiology}, volume = {200}, number = {2}, pages = {227-235}, doi = {10.1007/s00203-017-1432-8}, pmid = {28983672}, issn = {1432-072X}, mesh = {Animals ; China ; DNA, Ribosomal/genetics ; Female ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing ; In Situ Hybridization, Fluorescence ; Male ; Microbiota/*genetics ; Ovary/*microbiology ; Ovum/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizobiaceae/*classification/genetics/isolation &amp; purification ; Symbiosis/genetics ; Testis/*microbiology ; }, abstract = {Plant sap-feeding insects of Hemiptera often form intimate symbioses with microbes to obtain nutrients. The cicada Subpsaltria yangi is the only species of the subfamily Tettigadinae known from China. Using high-throughput sequencing combined with fluorescence in situ hybridization analysis, we characterize the bacterial composition of the bacteriomes, testes, ovaries and eggs of two representative populations of this species which occur in different habitats and feed on different plant hosts. In both populations, the bacterial community diversity in the testes was significantly higher than that in other tissues. The obligate endosymbiont Candidatus Sulcia muelleri was observed in all samples and was dominant in the bacteriomes, ovaries and eggs. The usual co-resident endosymbiont Candidatus Hodgkinia cicadicola found in some other cicadas was not detected. Instead, a novel Rhizobiales bacterium which shows a ~ 81% 16S rDNA similarity to Ca. Hodgkinia cicadicola was detected. Given that the genome of Ca. Hodgkinia cicadicola exhibits rapid evolution, it is possible that this novel Rhizobiales bacterium is a related endosymbiont with beneficial trophic functions similar to that of Ca. Hodgkinia cicadicola hosted by several certain other cicadas. The presence of the novel Rhizobiales species in other cicadas and its involvement with the adaptive evolution of related cicada hosts require further investigation. Discrepancy of bacterial communities associated with testes between the two populations may be closely related to the geographic isolation and divergence of habitats and host plants. Our results are informative for further studies of evolutionary divergence of related endosymbionts hosted in cicadas.}, }
@article {pmid28981693, year = {2017}, author = {Polsomboon, S and Hoel, DF and Murphy, JR and Linton, YM and Motoki, M and Robbins, RG and Bautista, K and Bricen O, I and Achee, NL and Grieco, JP and Ching, WM and Chao, CC}, title = {Molecular Detection and Identification of Rickettsia Species in Ticks (Acari: Ixodidae) Collected From Belize, Central America.}, journal = {Journal of medical entomology}, volume = {54}, number = {6}, pages = {1718-1726}, doi = {10.1093/jme/tjx141}, pmid = {28981693}, issn = {1938-2928}, mesh = {Animals ; Arthropod Vectors/*microbiology ; Belize ; Female ; Ixodidae/*microbiology ; Male ; Rickettsia/*classification/genetics/*isolation &amp; purification ; }, abstract = {Little is known about tick-borne rickettsial pathogens in Belize, Central America. We tested ixodid ticks for the presence of Rickettsia species in three of the six northern and western Belizean districts. Ticks were collected from domestic animals and tick drags over vegetation in 23 different villages in November 2014, February 2015, and May 2015. A total of 2,506 collected ticks were identified to the following species: Dermacentor nitens Neumann (46.69%), Rhipicephalus sanguineus (Latreille) (19.55%), Rhipicephalus microplus (Canestrini) (19.47%), Amblyomma cajennense complex (9.74%), Amblyomma maculatum Koch (3.47%), Amblyomma ovale Koch (0.68%), Ixodes nr affinis (0.16%), Amblyomma nr maculatum (0.12%), and Amblyomma nr oblongoguttatum (0.12%). Ticks were pooled according to species, life stage (larva, nymph, or adult), and location (n = 509) for DNA extraction and screened for genus Rickettsia by quantitative real-time polymerase chain reaction (qPCR). All 42 positive pools were found to be positive for spotted fever group (SFG) Rickettsia in pools of A. cajennense complex (n = 33), A. maculatum (n = 4), A. nr maculatum (n = 1), A. ovale (n = 1), R. sanguineus (n = 1), and I. nr affinis (n = 2). Rickettsia amblyommatis was identified from A. cajennense complex and A. nr maculatum. Rickettsia parkeri was found in A. maculatum, and Rickettsia sp. endosymbiont was detected in I. nr affinis. The presence of infected ticks suggests a risk of tick-borne rickettsioses to humans and animals in Belize. This knowledge can contribute to an effective tick management and disease control program benefiting residents and travelers.}, }
@article {pmid28981682, year = {2017}, author = {Takhampunya, R and Kim, HC and Chong, ST and Korkusol, A and Tippayachai, B and Davidson, SA and Petersen, JM and Klein, TA}, title = {Francisella-Like Endosymbiont Detected in Haemaphysalis Ticks (Acari: Ixodidae) From the Republic of Korea.}, journal = {Journal of medical entomology}, volume = {54}, number = {6}, pages = {1735-1742}, doi = {10.1093/jme/tjx123}, pmid = {28981682}, issn = {1938-2928}, mesh = {Animals ; Female ; Francisella tularensis/*isolation &amp; purification ; Ixodidae/*microbiology ; Male ; Republic of Korea ; Symbiosis ; }, abstract = {A total of 6,255 ticks belonging to three genera and six species (Haemaphysalis flava Neumann, Haemaphysalis longicornis Neumann, Haemaphysalis phasiana Saito, Ixodes nipponensis Kitaoka &amp; Saito, Ixodes persulcatus Schulze, and Amblyomma testudinarium Koch) collected from May-August, 2013, at four southwestern provinces in the Republic of Korea (ROK) were submitted to the Armed Forces Research Institute of Medical Sciences and assayed for selected tick-borne pathogens. One pool each of H. flava and H. phasiana was positive by PCR and sequencing for a Francisella-like endosymbiont, while all pools were negative for Francisella tularensis, the causative agent of tularemia.}, }
@article {pmid28978338, year = {2017}, author = {Gall, CA and Scoles, GA and Magori, K and Mason, KL and Brayton, KA}, title = {Laboratory colonization stabilizes the naturally dynamic microbiome composition of field collected Dermacentor andersoni ticks.}, journal = {Microbiome}, volume = {5}, number = {1}, pages = {133}, pmid = {28978338}, issn = {2049-2618}, support = {R01 AI044005/AI/NIAID NIH HHS/United States ; R37 AI044005/AI/NIAID NIH HHS/United States ; T32 GM008336/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Dermacentor/*microbiology ; Gastrointestinal Microbiome/genetics ; Microbiota/*genetics ; RNA, Ribosomal, 16S/genetics ; Salivary Glands/microbiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {BACKGROUND: Nearly a quarter of emerging infectious diseases identified in the last century are arthropod-borne. Although ticks and insects can carry pathogenic microorganisms, non-pathogenic microbes make up the majority of their microbial communities. The majority of tick microbiome research has had a focus on discovery and description; very few studies have analyzed the ecological context and functional responses of the bacterial microbiome of ticks. The goal of this analysis was to characterize the stability of the bacterial microbiome of Dermacentor andersoni ticks between generations and two populations within a species.<br><br>METHODS: The bacterial microbiome of D. andersoni midguts and salivary glands was analyzed from populations collected at two different ecologically distinct sites by comparing field (F1) and lab-reared populations (F1-F3) over three generations. The microbiome composition of pooled and individual samples was analyzed by sequencing nearly full-length 16S rRNA gene amplicons using a Pacific Biosciences CCS platform that allows identification of bacteria to the species level.<br><br>FINDINGS: In this study, we found that the D. andersoni microbiome was distinct in different geographic populations and was tissue specific, differing between the midgut and the salivary gland, over multiple generations. Additionally, our study showed that the microbiomes of laboratory-reared populations were not necessarily representative of their respective field populations. Furthermore, we demonstrated that the microbiome of a few individual ticks does not represent the microbiome composition at the population level.<br><br>CONCLUSIONS: We demonstrated that the bacterial microbiome of D. andersoni was complex over three generations and specific to tick tissue (midgut vs. salivary glands) as well as geographic location (Burns, Oregon vs. Lake Como, Montana vs. laboratory setting). These results provide evidence that habitat of the tick population is a vital component of the complexity of the bacterial microbiome of ticks, and that the microbiome of lab colonies may not allow for comparative analyses with field populations. A broader understanding of microbiome variation will be required if we are to employ manipulation of the microbiome as a method for interfering with acquisition and transmission of tick-borne pathogens.}, }
@article {pmid28973893, year = {2017}, author = {van Gestel, J and Tarnita, CE}, title = {On the origin of biological construction, with a focus on multicellularity.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {42}, pages = {11018-11026}, pmid = {28973893}, issn = {1091-6490}, mesh = {*Biological Evolution ; Life Cycle Stages ; *Morphogenesis ; Selection, Genetic ; }, abstract = {Biology is marked by a hierarchical organization: all life consists of cells; in some cases, these cells assemble into groups, such as endosymbionts or multicellular organisms; in turn, multicellular organisms sometimes assemble into yet other groups, such as primate societies or ant colonies. The construction of new organizational layers results from hierarchical evolutionary transitions, in which biological units (e.g., cells) form groups that evolve into new units of biological organization (e.g., multicellular organisms). Despite considerable advances, there is no bottom-up, dynamical account of how, starting from the solitary ancestor, the first groups originate and subsequently evolve the organizing principles that qualify them as new units. Guided by six central questions, we propose an integrative bottom-up approach for studying the dynamics underlying hierarchical evolutionary transitions, which builds on and synthesizes existing knowledge. This approach highlights the crucial role of the ecology and development of the solitary ancestor in the emergence and subsequent evolution of groups, and it stresses the paramount importance of the life cycle: only by evaluating groups in the context of their life cycle can we unravel the evolutionary trajectory of hierarchical transitions. These insights also provide a starting point for understanding the types of subsequent organizational complexity. The central research questions outlined here naturally link existing research programs on biological construction (e.g., on cooperation, multilevel selection, self-organization, and development) and thereby help integrate knowledge stemming from diverse fields of biology.}, }
@article {pmid28973572, year = {2017}, author = {Grau, T and Brandt, A and DeLeon, S and Meixner, MD and Strauß, JF and Joop, G and Telschow, A}, title = {A Comparison of Wolbachia Infection Frequencies in Varroa With Prevalence of Deformed Wing Virus.}, journal = {Journal of insect science (Online)}, volume = {17}, number = {3}, pages = {}, pmid = {28973572}, issn = {1536-2442}, mesh = {Animals ; Insect Viruses/*isolation &amp; purification ; Varroidae/*virology ; Wolbachia/*isolation &amp; purification ; }, abstract = {Wolbachia are widely distributed bacterial endosymbionts of arthropods and filarial nematodes. These bacteria can affect host fitness in a variety of ways, such as protecting hosts against viruses and other pathogens. Here, we investigate the possible role of Wolbachia in the prevalence of the deformed wing virus (DWV), a highly virulent pathogen of honey bees (Apis mellifera) that is transmitted by parasitic Varroa mites (Varroa destructor). About 180 Varroa mites from 18 beehives were tested for infection with Wolbachia and DWV. We first screened for Wolbachia using two standard primers (wsp and 16S rDNA), and found 26% of the mites to be positive for Wolbachia using the wsp primer and 64% of the mites to be positive using the 16S rDNA primer. Using these intermediate Wolbachia frequencies, we then tested for statistical correlations with virus infection frequencies. The analysis revealed a significant positive correlation between DWV and Wolbachia using the wsp primer, but no significant association between DWV and Wolbachia using the 16S rDNA primer. In conclusion, there is no evidence for an anti-pathogenic effect of Wolbachia in V. destructor, but weak evidence for a pro-pathogenic effect. These results encourage further examination of Wolbachia-virus interactions in Varroa mites since an increased vector competence of the mites may significantly impact disease outbreaks in honey bees.}, }
@article {pmid28969836, year = {2017}, author = {Khowawisetsut, L and Sarasombath, PT and Thammapalo, S and Loymek, S and Korbarsa, T and Nochote, H and Phuakrod, A and Choochote, W and Wongkamchai, S}, title = {Therapeutic trial of doxycyclin plus ivermectin for the treatment of Brugia malayi naturally infected cats.}, journal = {Veterinary parasitology}, volume = {245}, number = {}, pages = {42-47}, doi = {10.1016/j.vetpar.2017.08.009}, pmid = {28969836}, issn = {1873-2550}, mesh = {Animals ; *Brugia malayi ; Cat Diseases/drug therapy/*parasitology ; Cats ; Doxycycline/administration &amp; dosage/*therapeutic use ; Drug Therapy, Combination ; Filariasis/drug therapy/parasitology/*veterinary ; Ivermectin/administration &amp; dosage/*therapeutic use ; }, abstract = {Lymphatic filariasis (LF) is one of the neglected tropical diseases which causes permanent and long term disability worldwide. LF is caused by filarial nematode parasites, i.e. Wuchereria bancrofti, Brugia malayi, and B. timori. All available antifilarial drugs currently being used have shown a limited adulticidal activity. Discoveries of endosymbiont rickettsia-like bacterium, Wolbachia in filarial nematodes provided a novel approach for antibiotic use in eradication of filarial diseases. The earlier studies revealed the macrofilaricidal efficacy of doxycycline against filarial nematodes. Chemotherapeutic efficiency of doxycycline has been studied against many filarial parasites, but there are still no therapeutic trials of the drug regimens for B. malayi treatment in naturally infected cats. Thus, this study would be the first attempt to study the efficiency of doxycycline (DOXY) alone or in combination with ivermectin (IVM) for treatment of B. malayi in naturally infected cats. A total of 26 B. malayi-infected cats in the endemic areas were recruited and divided into 3 groups, receiving different treatment regimens; a single dose of ivermectin only (IVM), doxycycline only (DOXY) and a combination of ivermectin and doxycycline (DOXY-IVM). The efficacy of each therapatic regimen was evaluated by detecting the presence of microfilaria using parasitological and molecular techniques monthly up to 2 years after starting the treatment. The IVM treated group had a significant rapid reduction of microfilariae in the first month; however, recurrence of microfilaraemia was observed in some cats. By contrast, the DOXY and DOXY-IVM groups showed a better result with a gradual decrease in microfilariae with no recurrence. These 2 groups were not only virtually deprived of infection but also sustained the sterility of infection through the course of study. These results revealed the advantages of using in B. malayi treatment in cats. Doxycycline showed to have both microfilaricidal and adulticidal effects on lymphatic filariae which maintained the long-term response to control of B. malayi infection in cats.}, }
@article {pmid28961177, year = {2017}, author = {López-Madrigal, S and Gil, R}, title = {Et tu, Brute? Not Even Intracellular Mutualistic Symbionts Escape Horizontal Gene Transfer.}, journal = {Genes}, volume = {8}, number = {10}, pages = {}, pmid = {28961177}, issn = {2073-4425}, abstract = {Many insect species maintain mutualistic relationships with endosymbiotic bacteria. In contrast to their free-living relatives, horizontal gene transfer (HGT) has traditionally been considered rare in long-term endosymbionts. Nevertheless, meta-omics exploration of certain symbiotic models has unveiled an increasing number of bacteria-bacteria and bacteria-host genetic transfers. The abundance and function of transferred loci suggest that HGT might play a major role in the evolution of the corresponding consortia, enhancing their adaptive value or buffering detrimental effects derived from the reductive evolution of endosymbionts' genomes. Here, we comprehensively review the HGT cases recorded to date in insect-bacteria mutualistic consortia, and discuss their impact on the evolutionary success of these associations.}, }
@article {pmid28959730, year = {2017}, author = {Johnston, KL and Cook, DAN and Berry, NG and David Hong, W and Clare, RH and Goddard, M and Ford, L and Nixon, GL and O'Neill, PM and Ward, SA and Taylor, MJ}, title = {Identification and prioritization of novel anti-Wolbachia chemotypes from screening a 10,000-compound diversity library.}, journal = {Science advances}, volume = {3}, number = {9}, pages = {eaao1551}, pmid = {28959730}, issn = {2375-2548}, mesh = {Anti-Bacterial Agents/*chemistry/*pharmacology ; Cluster Analysis ; Computational Biology/methods ; Drug Discovery/methods ; Drug Evaluation, Preclinical/*methods ; Humans ; Reproducibility of Results ; *Small Molecule Libraries ; Wolbachia/*drug effects ; Workflow ; }, abstract = {Lymphatic filariasis and onchocerciasis are two important neglected tropical diseases (NTDs) that cause severe disability. Control efforts are hindered by the lack of a safe macrofilaricidal drug. Targeting the Wolbachia bacterial endosymbionts in these parasites with doxycycline leads to a macrofilaricidal outcome, but protracted treatment regimens and contraindications restrict its widespread implementation. The Anti-Wolbachia consortium aims to develop improved anti-Wolbachia drugs to overcome these barriers. We describe the first screening of a large, diverse compound library against Wolbachia. This whole-organism screen, streamlined to reduce bottlenecks, produced a hit rate of 0.5%. Chemoinformatic analysis of the top 50 hits led to the identification of six structurally diverse chemotypes, the disclosure of which could offer interesting avenues of investigation to other researchers active in this field. An example of hit-to-lead optimization is described to further demonstrate the potential of developing these high-quality hit series as safe, efficacious, and selective anti-Wolbachia macrofilaricides.}, }
@article {pmid28951480, year = {2017}, author = {Hirota, B and Okude, G and Anbutsu, H and Futahashi, R and Moriyama, M and Meng, XY and Nikoh, N and Koga, R and Fukatsu, T}, title = {A Novel, Extremely Elongated, and Endocellular Bacterial Symbiont Supports Cuticle Formation of a Grain Pest Beetle.}, journal = {mBio}, volume = {8}, number = {5}, pages = {}, pmid = {28951480}, issn = {2150-7511}, mesh = {Animals ; Bacteroidetes/genetics/*isolation &amp; purification/metabolism ; Coleoptera/growth &amp; development/*metabolism/*microbiology ; Evolution, Molecular ; Genome, Bacterial ; Larva ; Phylogeny ; Surface Properties ; *Symbiosis ; }, abstract = {The saw-toothed grain beetle, Oryzaephilus surinamensis (Silvanidae), is a cosmopolitan stored-product pest. Early studies on O. surinamensis in the 1930s described the presence of peculiar bacteriomes harboring endosymbiotic bacteria in the abdomen. Since then, however, the microbiological nature of the symbiont has been elusive. Here we investigated the endosymbiotic system of O. surinamensis in detail. In the abdomen of adults, pupae, and larvae, four oval bacteriomes were consistently identified, whose cytoplasm was full of extremely elongated tubular bacterial cells several micrometers wide and several hundred micrometers long. Molecular phylogenetic analysis identified the symbiont as a member of the Bacteroidetes, in which the symbiont was the most closely related to the endosymbiont of a grain pest beetle, Rhyzopertha dominica (Bostrichidae). The symbiont was detected in developing embryos, corroborating vertical symbiont transmission through host generations. The symbiont gene showed AT-biased nucleotide composition and accelerated molecular evolution, plausibly reflecting degenerative evolution of the symbiont genome. When the symbiont infection was experimentally removed, the aposymbiotic insects grew and reproduced normally, but exhibited a slightly but significantly more reddish cuticle and lighter body mass. These results indicate that the symbiont of O. surinamensis is not essential for the host's growth and reproduction but contributes to the host's cuticle formation. Symbiont genome sequencing and detailed comparison of fitness parameters between symbiotic and aposymbiotic insects under various environmental conditions will provide further insights into the symbiont's biological roles for the stored-product pest.IMPORTANCE Some beetles notorious as stored-product pests possess well-developed symbiotic organs called bacteriomes for harboring specific symbiotic bacteria, although their biological roles have been poorly understood. Here we report a peculiar endosymbiotic system of a grain pest beetle, Oryzaephilus surinamensis, in which four oval bacteriomes in the abdomen are full of extremely elongated tubular bacterial cells. Experimental symbiont elimination did not hinder the host's growth and reproduction, but resulted in emergence of reddish beetles, uncovering the symbiont's involvement in host's cuticle formation. We speculate that the extremely elongated symbiont cell morphology might be due to the degenerative symbiont genome deficient in bacterial cell division and/or cell wall formation, which highlights an evolutionary consequence of intimate host-symbiont coevolution.}, }
@article {pmid28949044, year = {2017}, author = {Dautermann, O and Lohr, M}, title = {A functional zeaxanthin epoxidase from red algae shedding light on the evolution of light-harvesting carotenoids and the xanthophyll cycle in photosynthetic eukaryotes.}, journal = {The Plant journal : for cell and molecular biology}, volume = {92}, number = {5}, pages = {879-891}, doi = {10.1111/tpj.13725}, pmid = {28949044}, issn = {1365-313X}, mesh = {Biological Evolution ; Genes, Plant ; Metabolic Networks and Pathways ; Oxidoreductases/genetics/*metabolism ; Photosynthesis ; Phylogeny ; Rhodophyta/genetics/*metabolism ; Xanthophylls/*metabolism ; }, abstract = {The epoxy-xanthophylls antheraxanthin and violaxanthin are key precursors of light-harvesting carotenoids and participate in the photoprotective xanthophyll cycle. Thus, the invention of zeaxanthin epoxidase (ZEP) catalyzing their formation from zeaxanthin has been a fundamental step in the evolution of photosynthetic eukaryotes. ZEP genes have only been found in Viridiplantae and chromalveolate algae with secondary plastids of red algal ancestry, suggesting that ZEP evolved in the Viridiplantae and spread to chromalveolates by lateral gene transfer. By searching publicly available sequence data from 11 red algae covering all currently recognized red algal classes we identified ZEP candidates in three species. Phylogenetic analyses showed that the red algal ZEP is most closely related to ZEP proteins from photosynthetic chromalveolates possessing secondary plastids of red algal origin. Its enzymatic activity was assessed by high performance liquid chromatography (HPLC) analyses of red algal pigment extracts and by cloning and functional expression of the ZEP gene from Madagascaria erythrocladioides in leaves of the ZEP-deficient aba2 mutant of Nicotiana plumbaginifolia. Unlike other ZEP enzymes examined so far, the red algal ZEP introduces only a single epoxy group into zeaxanthin, yielding antheraxanthin instead of violaxanthin. The results indicate that ZEP evolved before the split of Rhodophyta and Viridiplantae and that chromalveolates acquired ZEP from the red algal endosymbiont and not by lateral gene transfer. Moreover, the red algal ZEP enables engineering of transgenic plants incorporating antheraxanthin instead of violaxanthin in their photosynthetic machinery.}, }
@article {pmid28947798, year = {2017}, author = {Bouquet, J and Melgar, M and Swei, A and Delwart, E and Lane, RS and Chiu, CY}, title = {Metagenomic-based Surveillance of Pacific Coast tick Dermacentor occidentalis Identifies Two Novel Bunyaviruses and an Emerging Human Ricksettsial Pathogen.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {12234}, pmid = {28947798}, issn = {2045-2322}, support = {R01 HL105704/HL/NHLBI NIH HHS/United States ; T32 AI060537/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; California ; Dermacentor/*microbiology/*virology ; Epidemiological Monitoring ; High-Throughput Nucleotide Sequencing ; *Metagenomics ; Nairovirus/classification/genetics/*isolation &amp; purification ; Phlebovirus/classification/genetics/*isolation &amp; purification ; Prevalence ; Rickettsia/classification/genetics/*isolation &amp; purification ; }, abstract = {An increasing number of emerging tick-borne diseases has been reported in the United States since the 1970s. Using metagenomic next generation sequencing, we detected nucleic acid sequences from 2 novel viruses in the family Bunyaviridae and an emerging human rickettsial pathogen, Rickettsia philipii, in a population of the Pacific Coast tick, Dermacentor occidentalis in Mendocino County sampled annually from 2011 to 2014. A total of 250 adults of this human-biting, generalist tick were collected from contiguous chaparral and grassland habitats, and RNA from each individually extracted tick was deep sequenced to an average depth of 7.3 million reads. We detected a Francisella endosymbiont in 174 ticks (70%), and Rickettsia spp. in 19 ticks (8%); Rickettsia-infected ticks contained R. rhipicephali (16 of 250, 6.4%) or R. philipii (3 of 250,1.2%), the agent of eschar-associated febrile illness in humans. The genomes of 2 novel bunyaviruses (>99% complete) in the genera Nairovirus and Phlebovirus were also identified and found to be present in 20-91% of ticks, depending on the year of collection. The high prevalence of these bunyaviruses in sampled Dermacentor ticks suggests that they may be viral endosymbionts, although further studies are needed to determine whether they are infectious for vertebrate hosts, especially humans, and their potential role in tick ecology.}, }
@article {pmid28939611, year = {2017}, author = {Jain, M and Munoz-Bodnar, A and Gabriel, DW}, title = {Concomitant Loss of the Glyoxalase System and Glycolysis Makes the Uncultured Pathogen "Candidatus Liberibacter asiaticus" an Energy Scavenger.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {23}, pages = {}, pmid = {28939611}, issn = {1098-5336}, mesh = {Bacterial Proteins/*genetics/metabolism ; *Energy Metabolism ; *Glycolysis ; Rhizobiaceae/enzymology/*genetics/metabolism ; }, abstract = {Methylglyoxal (MG) is a cytotoxic, nonenzymatic by-product of glycolysis that readily glycates proteins and DNA, resulting in carbonyl stress. Glyoxalase I and II (GloA and GloB) sequentially convert MG into d-lactic acid using glutathione (GSH) as a cofactor. The glyoxalase system is essential for the mitigation of MG-induced carbonyl stress, preventing subsequent cell death, and recycling GSH for maintenance of cellular redox poise. All pathogenic liberibacters identified to date are uncultured, including "Candidatus Liberibacter asiaticus," a psyllid endosymbiont and causal agent of the severely damaging citrus disease "huanglongbing." In silico analysis revealed the absence of gloA in "Ca Liberibacter asiaticus" and all other pathogenic liberibacters. Both gloA and gloB are present in Liberibacter crescens, the only liberibacter that has been cultured. L. crescens GloA was functional in a heterologous host. Marker interruption of gloA in L. crescens appeared to be lethal. Key glycolytic enzymes were either missing or significantly downregulated in "Ca Liberibacter asiaticus" compared to (cultured) L. crescens Marker interruption of sut, a sucrose transporter gene in L. crescens, decreased its ability to take up exogenously supplied sucrose in culture. "Ca Liberibacter asiaticus" lacks a homologous sugar transporter but has a functional ATP/ADP translocase, enabling it to thrive both in psyllids and in the sugar-rich citrus phloem by (i) avoiding sucrose uptake, (ii) avoiding MG generation via glycolysis, and (iii) directly importing ATP from the host cell. MG detoxification enzymes appear to be predictive of "Candidatus" status for many uncultured pathogenic and environmental bacteria.IMPORTANCE Discovered more than 100 years ago, the glyoxalase system is thought to be present across all domains of life and fundamental to cellular growth and viability. The glyoxalase system protects against carbonyl stress caused by methylglyoxal (MG), a highly reactive, mutagenic and cytotoxic compound that is nonenzymatically formed as a by-product of glycolysis. The uncultured alphaproteobacterium "Ca Liberibacter asiaticus" is a well-adapted endosymbiont of the Asian citrus psyllid, which transmits the severely damaging citrus disease "huanglongbing." "Ca Liberibacter asiaticus" lacks a functional glyoxalase pathway. We report here that the bacterium is able to thrive both in psyllids and in the sugar-rich citrus phloem by (i) avoiding sucrose uptake, (ii) avoiding (significant) MG generation via glycolysis, and (iii) directly importing ATP from the host cell. We hypothesize that failure to culture "Ca Liberibacter asiaticus" is at least partly due to its dependence on host cells for both ATP and MG detoxification.}, }
@article {pmid28939559, year = {2017}, author = {Krams, IA and Kecko, S and Jõers, P and Trakimas, G and Elferts, D and Krams, R and Luoto, S and Rantala, MJ and Inashkina, I and Gudrā, D and Fridmanis, D and Contreras-Garduño, J and Grantiņa-Ieviņa, L and Krama, T}, title = {Microbiome symbionts and diet diversity incur costs on the immune system of insect larvae.}, journal = {The Journal of experimental biology}, volume = {220}, number = {Pt 22}, pages = {4204-4212}, doi = {10.1242/jeb.169227}, pmid = {28939559}, issn = {1477-9145}, mesh = {Animals ; Bacteria/genetics ; DNA, Bacterial/analysis ; Gastrointestinal Microbiome/*physiology ; *Herbivory ; *Immunity, Innate ; Larva/growth &amp; development/immunology/microbiology ; Moths/growth &amp; development/*immunology/*microbiology ; RNA, Ribosomal, 16S/analysis ; }, abstract = {Communities of symbiotic microorganisms that colonize the gastrointestinal tract play an important role in food digestion and protection against opportunistic microbes. Diet diversity increases the number of symbionts in the intestines, a benefit that is considered to impose no cost for the host organism. However, less is known about the possible immunological investments that hosts have to make in order to control the infections caused by symbiont populations that increase because of diet diversity. Using taxonomical composition analysis of the 16S rRNA V3 region, we show that enterococci are the dominating group of bacteria in the midgut of the larvae of the greater wax moth (Galleria mellonella). We found that the number of colony-forming units of enterococci and expressions of certain immunity-related antimicrobial peptide (AMP) genes such as Gallerimycin, Gloverin, 6-tox, Cecropin-D and Galiomicin increased in response to a more diverse diet, which in turn decreased the encapsulation response of the larvae. Treatment with antibiotics significantly lowered the expression of all AMP genes. Diet and antibiotic treatment interaction did not affect the expression of Gloverin and Galiomicin AMP genes, but significantly influenced the expression of Gallerimycin, 6-tox and Cecropin-D Taken together, our results suggest that diet diversity influences microbiome diversity and AMP gene expression, ultimately affecting an organism's capacity to mount an immune response. Elevated basal levels of immunity-related genes (Gloverin and Galiomicin) might act as a prophylactic against opportunistic infections and as a mechanism that controls the gut symbionts. This would indicate that a diverse diet imposes higher immunity costs on organisms.}, }
@article {pmid28936944, year = {2017}, author = {Araldi-Brondolo, SJ and Spraker, J and Shaffer, JP and Woytenko, EH and Baltrus, DA and Gallery, RE and Arnold, AE}, title = {Bacterial Endosymbionts: Master Modulators of Fungal Phenotypes.}, journal = {Microbiology spectrum}, volume = {5}, number = {5}, pages = {}, doi = {10.1128/microbiolspec.FUNK-0056-2016}, pmid = {28936944}, issn = {2165-0497}, mesh = {Bacteria/classification/genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Fungi/genetics/*physiology ; Phylogeny ; *Symbiosis ; }, abstract = {The ecological modes of fungi are shaped not only by their intrinsic features and the environment in which they occur, but also by their interactions with diverse microbes. Here we explore the ecological and genomic features of diverse bacterial endosymbionts-endohyphal bacteria-that together are emerging as major determinants of fungal phenotypes and plant-fungi interactions. We first provide a historical perspective on the study of endohyphal bacteria. We then propose a functional classification of three main groups, providing an overview of their genomic, phylogenetic, and ecological traits. Last, we explore frontiers in the study of endohyphal bacteria, with special attention to those facultative and horizontally transmitted bacteria that associate with some of the most diverse lineages of fungi. Overall, our aim is to synthesize the rich literature from nearly 50 years of studies on endohyphal bacteria as a means to highlight potential applications and new research directions.}, }
@article {pmid28935950, year = {2017}, author = {Xia, WQ and Wang, XR and Liang, Y and Liu, SS and Wang, XW}, title = {Transcriptome analyses suggest a novel hypothesis for whitefly adaptation to tobacco.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {12102}, pmid = {28935950}, issn = {2045-2322}, mesh = {Adaptation, Physiological/*genetics ; Animals ; Body Weight/genetics ; Fertility/genetics ; *Gene Expression Profiling ; Gene Ontology ; Hemiptera/*genetics/physiology ; High-Throughput Nucleotide Sequencing ; Host-Parasite Interactions ; Insect Proteins/*genetics ; Mediterranean Region ; Muscle Proteins/genetics ; Tobacco/parasitology ; Trichomes/parasitology ; }, abstract = {The adaptation of herbivorous insects to various host plants facilitates the spread and outbreak of many important invasive pests, however, the molecular mechanisms that underneath this process are poorly understood. In the past three decades, two species of the whitefly Bemisia tabaci complex, Middle East-Asia Minor 1 and Mediterranean, have invaded many countries. Their rapid and widespread invasions are partially due to their ability to infest a wide range of host plants. In this study, we determined the transcriptome and phenotypic changes of one Mediterranean whitefly population during its adaptation to tobacco, an unsuitable host plant. After several generations on tobacco, whiteflies showed increased survival and fecundity. High-throughput RNA sequencing showed that genes involved in muscle contraction and carbohydrate metabolism were significantly up-regulated after adaptation. Whiteflies reared on tobacco were further found to have increased body volume and muscle content and be trapped by tobacco trichomes in a lower frequency. On the other hand, gene expression in endosymbionts of whitefly did not change significantly after adaptation, which is consistent with the lack of cis-regulatory element on endosymbiont genomes. Over all, our data suggested that higher body volume and strengthened muscle might help whiteflies overcome physical barriers and survive on tobacco.}, }
@article {pmid28934627, year = {2017}, author = {Wernegreen, JJ}, title = {In it for the long haul: evolutionary consequences of persistent endosymbiosis.}, journal = {Current opinion in genetics &amp; development}, volume = {47}, number = {}, pages = {83-90}, doi = {10.1016/j.gde.2017.08.006}, pmid = {28934627}, issn = {1879-0380}, support = {S10 OD018164/OD/NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics/pathogenicity ; *Evolution, Molecular ; Genome, Bacterial ; Insecta/*genetics/microbiology ; Phylogeny ; Selection, Genetic ; Symbiosis/*genetics ; }, abstract = {Phylogenetically independent bacterial lineages have undergone a profound lifestyle shift: from a free-living to obligately host-associated existence. Among these lineages, intracellular bacterial mutualists of insects are among the most intimate, constrained symbioses known. These obligate endosymbionts exhibit severe gene loss and apparent genome deterioration. Evolutionary theory provides a basis to link their unusual genomic features with shifts in fundamental mechanisms - selection, genetic drift, mutation, and recombination. This mini-review highlights recent comparative and experimental research of processes shaping ongoing diversification within these ancient associations. Recent work supports clear contributions of stochastic processes, including genetic drift and exceptionally strong mutational pressure, toward degenerative evolution. Despite possible compensatory mechanisms, genome degradation may constrain how persistent endosymbionts (and their hosts) respond to environmental fluctuations.}, }
@article {pmid28932814, year = {2017}, author = {Simhadri, RK and Fast, EM and Guo, R and Schultz, MJ and Vaisman, N and Ortiz, L and Bybee, J and Slatko, BE and Frydman, HM}, title = {The Gut Commensal Microbiome of Drosophila melanogaster Is Modified by the Endosymbiont Wolbachia.}, journal = {mSphere}, volume = {2}, number = {5}, pages = {}, pmid = {28932814}, issn = {2379-5042}, abstract = {Endosymbiotic Wolbachia bacteria and the gut microbiome have independently been shown to affect several aspects of insect biology, including reproduction, development, life span, stem cell activity, and resistance to human pathogens, in insect vectors. This work shows that Wolbachia bacteria, which reside mainly in the fly germline, affect the microbial species present in the fly gut in a lab-reared strain. Drosophila melanogaster hosts two main genera of commensal bacteria-Acetobacter and Lactobacillus. Wolbachia-infected flies have significantly reduced titers of Acetobacter. Sampling of the microbiome of axenic flies fed with equal proportions of both bacteria shows that the presence of Wolbachia bacteria is a significant determinant of the composition of the microbiome throughout fly development. However, this effect is host genotype dependent. To investigate the mechanism of microbiome modulation, the effect of Wolbachia bacteria on Imd and reactive oxygen species pathways, the main regulators of immune response in the fly gut, was measured. The presence of Wolbachia bacteria does not induce significant changes in the expression of the genes for the effector molecules in either pathway. Furthermore, microbiome modulation is not due to direct interaction between Wolbachia bacteria and gut microbes. Confocal analysis shows that Wolbachia bacteria are absent from the gut lumen. These results indicate that the mechanistic basis of the modulation of composition of the microbiome by Wolbachia bacteria is more complex than a direct bacterial interaction or the effect of Wolbachia bacteria on fly immunity. The findings reported here highlight the importance of considering the composition of the gut microbiome and host genetic background during Wolbachia-induced phenotypic studies and when formulating microbe-based disease vector control strategies. IMPORTANCEWolbachia bacteria are intracellular bacteria present in the microbiome of a large fraction of insects and parasitic nematodes. They can block mosquitos' ability to transmit several infectious disease-causing pathogens, including Zika, dengue, chikungunya, and West Nile viruses and malaria parasites. Certain extracellular bacteria present in the gut lumen of these insects can also block pathogen transmission. However, our understanding of interactions between Wolbachia and gut bacteria and how they influence each other is limited. Here we show that the presence of Wolbachia strain wMel changes the composition of gut commensal bacteria in the fruit fly. Our findings implicate interactions between bacterial species as a key factor in determining the overall composition of the microbiome and thus reveal new paradigms to consider in the development of disease control strategies.}, }
@article {pmid28932232, year = {2017}, author = {Wang, Q and Sun, H and Huang, J}, title = {Re-analyses of "Algal" Genes Suggest a Complex Evolutionary History of Oomycetes.}, journal = {Frontiers in plant science}, volume = {8}, number = {}, pages = {1540}, pmid = {28932232}, issn = {1664-462X}, abstract = {The spread of photosynthesis is one of the most important but constantly debated topics in eukaryotic evolution. Various hypotheses have been proposed to explain the plastid distribution in extant eukaryotes. Notably, the chromalveolate hypothesis suggested that multiple eukaryotic lineages were derived from a photosynthetic ancestor that had a red algal endosymbiont. As such, genes of plastid/algal origin in aplastidic chromalveolates, such as oomycetes, were considered to be important supporting evidence. Although the chromalveolate hypothesis has been seriously challenged, some of its supporting evidence has not been carefully investigated. In this study, we re-evaluate the "algal" genes from oomycetes with a larger sampling and careful phylogenetic analyses. Our data provide no conclusive support for a common photosynthetic ancestry of stramenopiles, but show that the initial estimate of "algal" genes in oomycetes was drastically inflated due to limited genome data available then for certain eukaryotic lineages. These findings also suggest that the evolutionary histories of these "algal" genes might be attributed to complex scenarios such as differential gene loss, serial endosymbioses, or horizontal gene transfer.}, }
@article {pmid28931949, year = {2017}, author = {Bell, JB and Woulds, C and Oevelen, DV}, title = {Hydrothermal activity, functional diversity and chemoautotrophy are major drivers of seafloor carbon cycling.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {12025}, pmid = {28931949}, issn = {2045-2322}, abstract = {Hydrothermal vents are highly dynamic ecosystems and are unusually energy rich in the deep-sea. In situ hydrothermal-based productivity combined with sinking photosynthetic organic matter in a soft-sediment setting creates geochemically diverse environments, which remain poorly studied. Here, we use comprehensive set of new and existing field observations to develop a quantitative ecosystem model of a deep-sea chemosynthetic ecosystem from the most southerly hydrothermal vent system known. We find evidence of chemosynthetic production supplementing the metazoan food web both at vent sites and elsewhere in the Bransfield Strait. Endosymbiont-bearing fauna were very important in supporting the transfer of chemosynthetic carbon into the food web, particularly to higher trophic levels. Chemosynthetic production occurred at all sites to varying degrees but was generally only a small component of the total organic matter inputs to the food web, even in the most hydrothermally active areas, owing in part to a low and patchy density of vent-endemic fauna. Differences between relative abundance of faunal functional groups, resulting from environmental variability, were clear drivers of differences in biogeochemical cycling and resulted in substantially different carbon processing patterns between habitats.}, }
@article {pmid28930616, year = {2018}, author = {Eren, RO and Kopelyanskiy, D and Moreau, D and Chapalay, JB and Chambon, M and Turcatti, G and Lye, LF and Beverley, SM and Fasel, N}, title = {Development of a semi-automated image-based high-throughput drug screening system.}, journal = {Frontiers in bioscience (Elite edition)}, volume = {10}, number = {2}, pages = {242-253}, pmid = {28930616}, issn = {1945-0508}, support = {R01 AI029646/AI/NIAID NIH HHS/United States ; R56 AI099364/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antiprotozoal Agents/pharmacology ; *Automation ; Drug Evaluation, Preclinical/*methods ; *High-Throughput Screening Assays ; Leishmania/drug effects ; Macrophages/parasitology ; Mice ; Mice, Inbred C57BL ; }, abstract = {We previously reported that the innate sensing of the endosymbiont Leishmania RNA virus 1 (LRV1) within Leishmania (Viannia) guyanensis through Toll-like receptor 3, worsens the pathogenesis of parasite infection in mice. The presence of LRV1 has been associated with the failure of first-line treatment in patients infected with LRV1 containing -L. guyanensis and -L. braziliensis parasites. Here, we established a semi-automated image-based high-throughput drug screening (HTDS) protocol to measure parasiticidal activity of the Prestwick chemical library in primary murine macrophages infected with LRV1-containing L. guyanensis. The two-independent screens generated 14 hit compounds with over sixty-nine percent reduction in parasite growth compared to control, at a single dose in both screens. Our screening strategy offers great potential in the search for new drugs and accelerates the discovery rate in the field of drug repurposing against Leishmania. Moreover, this technique allows the concomitant assessment of the effect of drug toxicity on host cell number.}, }
@article {pmid28923972, year = {2017}, author = {Anbutsu, H and Moriyama, M and Nikoh, N and Hosokawa, T and Futahashi, R and Tanahashi, M and Meng, XY and Kuriwada, T and Mori, N and Oshima, K and Hattori, M and Fujie, M and Satoh, N and Maeda, T and Shigenobu, S and Koga, R and Fukatsu, T}, title = {Small genome symbiont underlies cuticle hardness in beetles.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {40}, pages = {E8382-E8391}, pmid = {28923972}, issn = {1091-6490}, mesh = {Animals ; Bacteria/*pathogenicity ; Bacterial Physiological Phenomena ; Evolution, Molecular ; Gene Expression Profiling ; *Genome, Bacterial ; High-Throughput Nucleotide Sequencing ; Host-Pathogen Interactions ; Integumentary System/*physiology ; *Symbiosis ; Transaminases/*metabolism ; Tyrosine/*metabolism ; Weevils/*genetics/microbiology ; }, abstract = {Beetles, representing the majority of the insect species diversity, are characterized by thick and hard cuticle, which plays important roles for their environmental adaptation and underpins their inordinate diversity and prosperity. Here, we report a bacterial endosymbiont extremely specialized for sustaining beetle's cuticle formation. Many weevils are associated with a γ-proteobacterial endosymbiont lineage Nardonella, whose evolutionary origin is estimated as older than 100 million years, but its functional aspect has been elusive. Sequencing of Nardonella genomes from diverse weevils unveiled drastic size reduction to 0.2 Mb, in which minimal complete gene sets for bacterial replication, transcription, and translation were present but almost all of the other metabolic pathway genes were missing. Notably, the only metabolic pathway retained in the Nardonella genomes was the tyrosine synthesis pathway, identifying tyrosine provisioning as Nardonella's sole biological role. Weevils are armored with hard cuticle, tyrosine is the principal precursor for cuticle formation, and experimental suppression of Nardonella resulted in emergence of reddish and soft weevils with low tyrosine titer, confirming the importance of Nardonella-mediated tyrosine production for host's cuticle formation and hardening. Notably, Nardonella's tyrosine synthesis pathway was incomplete, lacking the final step transaminase gene. RNA sequencing identified host's aminotransferase genes up-regulated in the bacteriome. RNA interference targeting the aminotransferase genes induced reddish and soft weevils with low tyrosine titer, verifying host's final step regulation of the tyrosine synthesis pathway. Our finding highlights an impressively intimate and focused aspect of the host-symbiont metabolic integrity via streamlined evolution for a single biological function of ecological relevance.}, }
@article {pmid28917710, year = {2017}, author = {Milanez, GD and Masangkay, FR and Thomas, RC and Ordona, MOGO and Bernales, GQ and Corpuz, VCM and Fortes, HSV and Garcia, CMS and Nicolas, LC and Nissapatorn, V}, title = {Molecular identification of Vermamoeba vermiformis from freshwater fish in lake Taal, Philippines.}, journal = {Experimental parasitology}, volume = {183}, number = {}, pages = {201-206}, doi = {10.1016/j.exppara.2017.09.009}, pmid = {28917710}, issn = {1090-2449}, mesh = {Amebiasis/parasitology/*veterinary ; Animals ; Cichlids/*parasitology ; DNA, Protozoan/chemistry/isolation &amp; purification ; Fish Diseases/*parasitology ; Fisheries ; Fresh Water ; Gills/parasitology ; Intestines/parasitology ; Lakes ; Philippines ; Phylogeny ; Sequence Alignment ; Trophozoites/isolation &amp; purification/physiology/ultrastructure ; Tubulina/classification/genetics/*isolation &amp; purification ; }, abstract = {Free Living Amoebae (FLA) are considered ubiquitous. FLAs may infect various biological organisms which act as reservoir hosts. Infected freshwater fishes can pose a public health concern due to possible human consumption. This study aims to identify possible pathogenic FLAs present in freshwater fishes. Seventy five (75) Oreochromis niloticus were studied for the presence of FLAs. Fish organs were suspended in physiologic saline pelleted and cultured in non-nutrient agar (NNA) lawned with Escherichia coli and were incubated in 33 °C for 14 days. Eighteen (18) fish gills and nineteen (19) fish intestine samples presented with positive growth. Trophozoites and cystic stages of FLAs were subcultured until homogenous growth was achieved. Cells were harvested from cultured plates and DNA was extracted using Chelex resin. DNA was subjected to polymerase chain reaction using universal forward primer EukA and reverse primer EukB targeting the 18s RNA. Of the 37 plates that presented with positive amoebic growth, 9 samples showed the presence of DNAs and were sent for further purification and sequencing. Basic Local Alignment Search Tool (BLAST) results showed that protists isolated from fish organs in Lake Taal include: Eocercomonas (HM536152), Colpoda steinii (KJ607915) and Vermamoeba vermiformis (KC161965). The results showed that fresh-water fishes can harbour FLAs in the gut. It is proposed that freshwater reservoirs utilized for aquaculture be monitored for the presence of FLAs and extensive study be conducted on the pathogenicity of bacterial endosymbionts and infecting viruses to its mammalian and non-mammalian host.}, }
@article {pmid28916841, year = {2017}, author = {Dunn, CD}, title = {Some Liked It Hot: A Hypothesis Regarding Establishment of the Proto-Mitochondrial Endosymbiont During Eukaryogenesis.}, journal = {Journal of molecular evolution}, volume = {85}, number = {3-4}, pages = {99-106}, pmid = {28916841}, issn = {1432-1432}, support = {637649/ERC_/European Research Council/International ; }, mesh = {Archaea/*genetics/metabolism ; Bacteria/genetics ; *Biological Evolution ; Energy Metabolism ; Eukaryota/*genetics/metabolism ; *Hot Temperature ; Mitochondria/genetics/*metabolism/physiology ; *Symbiosis ; }, abstract = {Eukaryotic cells are characterized by a considerable increase in subcellular compartmentalization when compared to prokaryotes. Most evidence suggests that the earliest eukaryotes consisted of mitochondria derived from an α-proteobacterial ancestor enclosed within an archaeal host cell. However, what benefits the archaeal host and the proto-mitochondrial endosymbiont might have obtained at the beginning of this endosymbiotic relationship remains unclear. In this work, I argue that heat generated by the proto-mitochondrion initially permitted an archaeon living at high temperatures to colonize a cooler environment, thereby removing apparent limitations on cellular complexity. Furthermore, heat generation by the endosymbiont would have provided phenotypic flexibility not available through fixed alleles selected for fitness at specific temperatures. Finally, a role for heat production by the proto-mitochondrion bridges a conceptual gap between initial endosymbiont entry to the archaeal host and a later role for mitochondrial ATP production in permitting increased cellular complexity.}, }
@article {pmid28916813, year = {2017}, author = {Tanifuji, G and Cenci, U and Moog, D and Dean, S and Nakayama, T and David, V and Fiala, I and Curtis, BA and Sibbald, SJ and Onodera, NT and Colp, M and Flegontov, P and Johnson-MacKinnon, J and McPhee, M and Inagaki, Y and Hashimoto, T and Kelly, S and Gull, K and Lukeš, J and Archibald, JM}, title = {Genome sequencing reveals metabolic and cellular interdependence in an amoeba-kinetoplastid symbiosis.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {11688}, pmid = {28916813}, issn = {2045-2322}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Amoebozoa/genetics/*growth &amp; development/*metabolism ; Genome, Protozoan ; Kinetoplastida/genetics/*growth &amp; development/*metabolism ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Endosymbiotic relationships between eukaryotic and prokaryotic cells are common in nature. Endosymbioses between two eukaryotes are also known; cyanobacterium-derived plastids have spread horizontally when one eukaryote assimilated another. A unique instance of a non-photosynthetic, eukaryotic endosymbiont involves members of the genus Paramoeba, amoebozoans that infect marine animals such as farmed fish and sea urchins. Paramoeba species harbor endosymbionts belonging to the Kinetoplastea, a diverse group of flagellate protists including some that cause devastating diseases. To elucidate the nature of this eukaryote-eukaryote association, we sequenced the genomes and transcriptomes of Paramoeba pemaquidensis and its endosymbiont Perkinsela sp. The endosymbiont nuclear genome is ~9.5 Mbp in size, the smallest of a kinetoplastid thus far discovered. Genomic analyses show that Perkinsela sp. has lost the ability to make a flagellum but retains hallmark features of kinetoplastid biology, including polycistronic transcription, trans-splicing, and a glycosome-like organelle. Mosaic biochemical pathways suggest extensive 'cross-talk' between the two organisms, and electron microscopy shows that the endosymbiont ingests amoeba cytoplasm, a novel form of endosymbiont-host communication. Our data reveal the cell biological and biochemical basis of the obligate relationship between Perkinsela sp. and its amoeba host, and provide a foundation for understanding pathogenicity determinants in economically important Paramoeba.}, }
@article {pmid28916561, year = {2018}, author = {Mitsch, MJ and diCenzo, GC and Cowie, A and Finan, TM}, title = {Succinate Transport Is Not Essential for Symbiotic Nitrogen Fixation by Sinorhizobium meliloti or Rhizobium leguminosarum.}, journal = {Applied and environmental microbiology}, volume = {84}, number = {1}, pages = {}, pmid = {28916561}, issn = {1098-5336}, mesh = {Bacterial Proteins/genetics/metabolism ; Biological Transport ; Malates/metabolism ; *Nitrogen Fixation ; Rhizobium leguminosarum/*metabolism ; Sinorhizobium meliloti/*metabolism ; Succinic Acid/*metabolism ; *Symbiosis ; Systems Biology ; }, abstract = {Symbiotic nitrogen fixation (SNF) is an energetically expensive process performed by bacteria during endosymbiotic relationships with plants. The bacteria require the plant to provide a carbon source for the generation of reductant to power SNF. While C4-dicarboxylates (succinate, fumarate, and malate) appear to be the primary, if not sole, carbon source provided to the bacteria, the contribution of each C4-dicarboxylate is not known. We address this issue using genetic and systems-level analyses. Expression of a malate-specific transporter (MaeP) in Sinorhizobium meliloti Rm1021 dct mutants unable to transport C4-dicarboxylates resulted in malate import rates of up to 30% that of the wild type. This was sufficient to support SNF with Medicago sativa, with acetylene reduction rates of up to 50% those of plants inoculated with wild-type S. melilotiRhizobium leguminosarum bv. viciae 3841 dct mutants unable to transport C4-dicarboxylates but expressing the maeP transporter had strong symbiotic properties, with Pisum sativum plants inoculated with these strains appearing similar to plants inoculated with wild-type R. leguminosarum This was despite malate transport rates by the mutant bacteroids being 10% those of the wild type. An RNA-sequencing analysis of the combined P. sativum-R. leguminosarum nodule transcriptome was performed to identify systems-level adaptations in response to the inability of the bacteria to import succinate or fumarate. Few transcriptional changes, with no obvious pattern, were detected. Overall, these data illustrated that succinate and fumarate are not essential for SNF and that, at least in specific symbioses, l-malate is likely the primary C4-dicarboxylate provided to the bacterium.IMPORTANCE Symbiotic nitrogen fixation (SNF) is an economically and ecologically important biological process that allows plants to grow in nitrogen-poor soils without the need to apply nitrogen-based fertilizers. Much research has been dedicated to this topic to understand this process and to eventually manipulate it for agricultural gains. The work presented in this article provides new insights into the metabolic integration of the plant and bacterial partners. It is shown that malate is the only carbon source that needs to be available to the bacterium to support SNF and that, at least in some symbioses, malate, and not other C4-dicarboxylates, is likely the primary carbon provided to the bacterium. This work extends our knowledge of the minimal metabolic capabilities the bacterium requires to successfully perform SNF and may be useful in further studies aiming to optimize this process through synthetic biology approaches. The work describes an engineering approach to investigate a metabolic process that occurs between a eukaryotic host and its prokaryotic endosymbiont.}, }
@article {pmid28914880, year = {2018}, author = {Gil, R and Vargas-Chavez, C and López-Madrigal, S and Santos-García, D and Latorre, A and Moya, A}, title = {Tremblaya phenacola PPER: an evolutionary beta-gammaproteobacterium collage.}, journal = {The ISME journal}, volume = {12}, number = {1}, pages = {124-135}, pmid = {28914880}, issn = {1751-7370}, mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Betaproteobacteria/classification/*genetics/isolation &amp; purification/physiology ; Biological Evolution ; Gene Transfer, Horizontal ; Genome, Bacterial ; Hemiptera/*microbiology/physiology ; Phylogeny ; Symbiosis ; }, abstract = {Many insects rely on bacterial endosymbionts to obtain nutrients that are scarce in their highly specialized diets. The most surprising example corresponds to the endosymbiotic system found in mealybugs from subfamily Pseudococcinae in which two bacteria, the betaproteobacterium 'Candidatus Tremblaya princeps' and a gammaproteobacterium, maintain a nested endosymbiotic consortium. In the sister subfamily Phenacoccinae, however, a single beta-endosymbiont, 'Candidatus Tremblaya phenacola', has been described. In a previous study, we detected a trpB gene of gammaproteobacterial origin in 'Ca. Tremblaya phenacola' from two Phenacoccus species, apparently indicating an unusual case of horizontal gene transfer (HGT) in a bacterial endosymbiont. What we found by sequencing the genome of 'Ca. Tremblaya phenacola' PPER, single endosymbiont of Phenacoccus peruvianus, goes beyond a HGT phenomenon. It rather represents a genome fusion between a beta and a gammaproteobacterium, followed by massive rearrangements and loss of redundant genes, leading to an unprecedented evolutionary collage. Mediated by the presence of several repeated sequences, there are many possible genome arrangements, and different subgenomic sequences might coexist within the same population.}, }
@article {pmid28912756, year = {2017}, author = {Torres, MJ and Bueno, E and Jiménez-Leiva, A and Cabrera, JJ and Bedmar, EJ and Mesa, S and Delgado, MJ}, title = {FixK2 Is the Main Transcriptional Activator of Bradyrhizobium diazoefficiens nosRZDYFLX Genes in Response to Low Oxygen.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {1621}, pmid = {28912756}, issn = {1664-302X}, abstract = {The powerful greenhouse gas, nitrous oxide (N2O) has a strong potential to drive climate change. Soils are the major source of N2O and microbial nitrification and denitrification the main processes involved. The soybean endosymbiont Bradyrhizobium diazoefficiens is considered a model to study rhizobial denitrification, which depends on the napEDABC, nirK, norCBQD, and nosRZDYFLX genes. In this bacterium, the role of the regulatory cascade FixLJ-FixK2-NnrR in the expression of napEDABC, nirK, and norCBQD genes involved in N2O synthesis has been previously unraveled. However, much remains to be discovered regarding the regulation of the respiratory N2O reductase (N2OR), the key enzyme that mitigates N2O emissions. In this work, we have demonstrated that nosRZDYFLX genes constitute an operon which is transcribed from a major promoter located upstream of the nosR gene. Low oxygen was shown to be the main inducer of expression of nosRZDYFLX genes and N2OR activity, FixK2 being the regulatory protein involved in such control. Further, by using an in vitro transcription assay with purified FixK2 protein and B. diazoefficiens RNA polymerase we were able to show that the nosRZDYFLX genes are direct targets of FixK2.}, }
@article {pmid28905230, year = {2017}, author = {Huber, D and Reil, I and Duvnjak, S and Jurković, D and Lukačević, D and Pilat, M and Beck, A and Mihaljević, &#x17d; and Vojta, L and Polkinghorne, A and Beck, R}, title = {Molecular detection of Anaplasma platys, Anaplasma phagocytophilum and Wolbachia sp. but not Ehrlichia canis in Croatian dogs.}, journal = {Parasitology research}, volume = {116}, number = {11}, pages = {3019-3026}, pmid = {28905230}, issn = {1432-1955}, mesh = {Anaplasma/classification/*isolation &amp; purification ; Anaplasma phagocytophilum/genetics/*isolation &amp; purification ; Anaplasmosis/epidemiology/*microbiology ; Animals ; Base Sequence ; Croatia/epidemiology ; Dog Diseases/epidemiology/*microbiology ; Dogs ; Ehrlichia canis/*isolation &amp; purification ; Ehrlichiosis/veterinary ; Phylogeny ; Polymerase Chain Reaction/veterinary ; RNA, Bacterial ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus sanguineus/microbiology ; Rickettsiaceae Infections/epidemiology/microbiology/*veterinary ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {The bacteria Anaplasma platys, Anaplasma phagocytophilum and Ehrlichia canis are tick-borne agents that cause canine vector-borne disease. The prevalence of these pathogens in South Eastern Europe is unknown with the exception of an isolated case of A. platys detected in a dog imported into Germany from Croatia. To gain a better insight into their presence and prevalence, PCR-based screening for these bacterial pathogens was performed on domesticated dogs from different regions of Croatia. Blood samples from 1080 apparently healthy dogs from coastal and continental parts of Croatia as well as tissue samples collected from 63 deceased dogs with a history of anaemia and thrombocytopenia were collected for molecular screening by an Anaplasmataceae-specific 16S rRNA conventional PCR. Positive samples were confirmed using a second Anaplasmataceae-specific PCR assay with the PCR product sequenced for the purpose of bacterial species identification. All sequenced isolates were georeferenced and a kernel intensity estimator was used to identify clusters of greater case intensity. 42/1080 (3.8%; CI 2.7-5.0) of the healthy dogs were PCR positive for bacteria in the Anaplasmataceae. Sequencing of the 16S rRNA gene amplified from these positive samples revealed the presence of A. platys in 2.5% (CI 1.6-3.4%, 27 dogs), A. phagocytophilum in 0.3% (CI 0-0.6%, 3 dogs) and a Wolbachia endosymbiont in 1.1% (CI 0.4-1.6%, 12 dogs) of dogs screened in this study. Necropsied dogs were free from infection. Notably, no evidence of E. canis infection was found in any animal. This survey represents a rare molecular study of Anaplasmataceae in dogs in South Eastern Europe, confirming the presence of A. platys and A. phagocytophilum but not E. canis. The absence of E. canis was surprising given it has been described in all other Mediterranean countries surveyed and raises questions over the regional vector capacity of the Rhipicephalus sanguineus tick.}, }
@article {pmid28904857, year = {2017}, author = {Tang, VH and Stewart, GA and Chang, BJ}, title = {Dermatophagoides pteronyssinus lytFM encoding an NlpC/P60 endopeptidase is also present in mite-associated bacteria that express LytFM variants.}, journal = {FEBS open bio}, volume = {7}, number = {9}, pages = {1267-1280}, pmid = {28904857}, issn = {2211-5463}, abstract = {The bodies and faecal pellets of the house dust mite (HDM), Dermatophagoides pteronyssinus, are the source of many allergenic and nonallergenic proteins. One of these, the 14-kDa bacteriolytic enzyme LytFM, originally isolated from the spent HDM growth medium, may contribute to bacteriolytic activity previously detected by zymography at 14 kDa in the culture supernatants of some bacterial species isolated from surface-sterilised HDM. Based on previously reported findings of lateral gene transfer between microbes and their eukaryotic hosts, we investigated the presence of lytFM in the genomes of nine Gram-positive bacteria from surface-sterilised HDM, and the expression by these isolates of LytFM and its variants LytFM1/LytFM2. The lytFM gene was detected by PCR in the genomes of three of the isolates: Bacillus licheniformis strain 1, B. licheniformis strain 2 and Staphylococcus aureus. Expression of the variant LytFM1 was detected in culture supernatants of these bacteria by mass spectrometry (MS) and ELISA, and the bacterial LytFM proteins were shown by zymography to be able to hydrolyse peptidoglycan. Our previous reports of LytFM homologues in other mite species and their phylogenetic analysis had suggested that they originated from a common mite ancestor. The phylogenetic analysis reported herein and the detection of other D. pteronyssinus proteins by MS in the culture supernatants of the three isolates that secreted LytFM1 further support the hypothesis of lateral gene transfer to the bacterial endosymbionts from their HDM host. The complete sequence homology observed between the genes amplified from the microbes and those in their eukaryotic host indicated that the lateral gene transfer was an event that occurred recently.}, }
@article {pmid28904788, year = {2017}, author = {Beatty, CD and Sánchez Herrera, M and Skevington, JH and Rashed, A and Van Gossum, H and Kelso, S and Sherratt, TN}, title = {Biogeography and systematics of endemic island damselflies: The Nesobasis and Melanesobasis (Odonata: Zygoptera) of Fiji.}, journal = {Ecology and evolution}, volume = {7}, number = {17}, pages = {7117-7129}, pmid = {28904788}, issn = {2045-7758}, abstract = {The study of island fauna has greatly informed our understanding of the evolution of diversity. We here examine the phylogenetics, biogeography, and diversification of the damselfly genera Nesobasis and Melanesobasis, endemic to the Fiji Islands, to explore mechanisms of speciation in these highly speciose groups. Using mitochondrial (COI, 12S) and nuclear (ITS) replicons, we recovered garli-part maximum likelihood and mrbayes Bayesian phylogenetic hypotheses for 26 species of Nesobasis and eight species/subspecies of Melanesobasis. Biogeographical patterns were explored using lagrange and bayes-lagrange and interpreted through beast relaxed clock dating analyses. We found that Nesobasis and Melanesobasis have radiated throughout Fiji, but are not sister groups. For Nesobasis, while the two largest islands of the archipelago-Viti Levu and Vanua Levu-currently host two distinct species assemblages, they do not represent phylogenetic clades; of the three major groupings each contains some Viti Levu and some Vanua Levu species, suggesting independent colonization events across the archipelago. Our beast analysis suggests a high level of species diversification around 2-6 Ma. Our ancestral area reconstruction (rasp-lagrange) suggests that both dispersal and vicariance events contributed to the evolution of diversity. We thus conclude that the evolutionary history of Nesobasis and Melanesobasis is complex; while inter-island dispersal followed by speciation (i.e., peripatry) has contributed to diversity, speciation within islands appears to have taken place a number of times as well. This speciation has taken place relatively recently and appears to be driven more by reproductive isolation than by ecological differentiation: while species in Nesobasis are morphologically distinct from one another, they are ecologically very similar, and currently are found to exist sympatrically throughout the islands on which they are distributed. We consider the potential for allopatric speciation within islands, as well as the influence of parasitic endosymbionts, to explain the high rates of speciation in these damselflies.}, }
@article {pmid28902188, year = {2017}, author = {Gebiola, M and Kelly, SE and Velten, L and Zug, R and Hammerstein, P and Giorgini, M and Hunter, MS}, title = {Reproductive interference and fecundity affect competitive interactions of sibling species with low mating barriers: experimental and theoretical evidence.}, journal = {Heredity}, volume = {119}, number = {6}, pages = {438-446}, pmid = {28902188}, issn = {1365-2540}, mesh = {Animals ; Bacteroidetes ; Female ; *Fertility ; Hybridization, Genetic ; Male ; Models, Theoretical ; Population Dynamics ; *Reproductive Isolation ; Symbiosis ; *Sympatry ; Wasps/*genetics/microbiology ; }, abstract = {When allopatric species with incomplete prezygotic isolation come into secondary contact, the outcome of their interaction is not easily predicted. The parasitoid wasp Encarsia suzannae (iES), infected by Cardinium inducing cytoplasmic incompatibility (CI), and its sibling species E. gennaroi (EG), not infected by bacterial endosymbionts, may have diverged because of the complementary action of CI and asymmetric hybrid incompatibilities. Whereas postzygotic isolation is now complete because of sterility of F1 hybrid progeny, prezygotic isolation is still incipient. We set up laboratory population cage experiments to evaluate the outcome of the interaction between ES and EG in two pairwise combinations: iES vs EG and cured ES (cES, where Cardinium was removed with antibiotics) vs EG. We also built a theoretical model aimed at exploring the role of life-history differences and asymmetric mating on competitive outcomes. In three of four cages in each treatment, ES dominated the interaction. We found evidence for reproductive interference, driven by asymmetric mating preferences, that gave a competitive edge to ES, the species that better discriminated against heterospecifics. However, we did not find the fecundity cost previously shown to be associated with Cardinium infection in iES. The model largely supported the experimental results. The finding of only a slight competitive edge of ES over EG in population cages suggests that in a more heterogeneous environment the species could coexist. This is supported by evidence that the two species coexist in sympatry, where preliminary data suggest reproductive character displacement may have reinforced postzygotic isolation.}, }
@article {pmid28889978, year = {2017}, author = {Singer, A and Poschmann, G and Mühlich, C and Valadez-Cano, C and Hänsch, S and Hüren, V and Rensing, SA and Stühler, K and Nowack, ECM}, title = {Massive Protein Import into the Early-Evolutionary-Stage Photosynthetic Organelle of the Amoeba Paulinella chromatophora.}, journal = {Current biology : CB}, volume = {27}, number = {18}, pages = {2763-2773.e5}, doi = {10.1016/j.cub.2017.08.010}, pmid = {28889978}, issn = {1879-0445}, mesh = {Cercozoa/*physiology ; Chromatophores/*physiology ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Mass Spectrometry ; Metabolic Networks and Pathways ; Proteome/*analysis ; Protozoan Proteins/*analysis ; Sequence Analysis, Protein ; Symbiosis ; }, abstract = {The endosymbiotic acquisition of mitochondria and plastids more than 1 Ga ago profoundly impacted eukaryote evolution. At the heart of understanding organelle evolution is the re-arrangement of the endosymbiont proteome into a host-controlled organellar proteome. However, early stages in this process as well as the timing of events that underlie organelle integration remain poorly understood. The amoeba Paulinella chromatophora contains cyanobacterium-derived photosynthetic organelles, termed "chromatophores," that were acquired more recently (around 100 Ma ago). To explore the re-arrangement of an organellar proteome during its integration into a eukaryotic host cell, here we characterized the chromatophore proteome by protein mass spectrometry. Apparently, genetic control over the chromatophore has shifted substantially to the nucleus. Two classes of nuclear-encoded proteins-which differ in protein length-are imported into the chromatophore, most likely through independent pathways. Long imported proteins carry a putative, conserved N-terminal targeting signal, and many specifically fill gaps in chromatophore-encoded metabolic pathways or processes. Surprisingly, upon heterologous expression in a plant cell, the putative chromatophore targeting signal conferred chloroplast localization. This finding suggests common features in the protein import pathways of chromatophores and plastids, two organelles that evolved independently and more than 1 Ga apart from each other. By combining experimental data with in silico predictions, we provide a comprehensive catalog of almost 450 nuclear-encoded, chromatophore-targeted proteins. Interestingly, most imported proteins seem to derive from ancestral host genes, suggesting that the re-targeting of nuclear-encoded proteins that resulted from endosymbiotic gene transfers plays only a minor role at the onset of chromatophore integration.}, }
@article {pmid28889012, year = {2017}, author = {Gajbhiye, DS and Khandeparker, L}, title = {Effect of pea crab Pinnotheres vicajii (Chhapgar, 1957) on immunocompetence of bivalve Paphia malabarica (Chemnitz, 1782).}, journal = {Fish &amp; shellfish immunology}, volume = {70}, number = {}, pages = {319-326}, doi = {10.1016/j.fsi.2017.08.044}, pmid = {28889012}, issn = {1095-9947}, mesh = {Animals ; Bivalvia/immunology/*physiology ; Brachyura/*physiology ; Hemocytes/immunology ; *Immunocompetence ; India ; *Symbiosis ; }, abstract = {The endosymbiont-host relationship between a pea crab and its bivalve host has been studied previously using bivalve's multi-physiological parameters. The present study is first of its kind that uses hemocyte's immune functionality to evaluate the symbiotic relationship between bivalve Paphia malabarica and its symbiont crab, Pinnotheres vicajii. The sampling was carried out at two stations (differed in nutrient concentration, productivity, and bacterial abundance) located along the southwest coast of India. The results showed lower immunocompetence in the case of bivalves infested with pea crabs. The lowering of hemocyte population was the most prominent and perhaps the initial reaction in response to focal inflammation or wound inflicted by the pea crabs. A significant lowering of phagocytosis, lysozyme, and esterase activity was also observed, indicating the detrimental impact of crab infestation. Interestingly, no significant correlation was found between parasitism and condition index despite the lower immunocompetence, validating the effectiveness of using hematological parameters in comparison to other life-history traits. This indicates that the immune parameters being directly related to the organism's metabolic state can elucidate the early effect of stressors, therefore, proving to be a better proxy for understanding a host-pathogen relationship. Disparity found in bivalve's immunocompetence between the sampling sites could be linked to either variation in environmental parameters, the size of the symbiont or the infection level. Our preliminary results provide a direction towards examining immunodepression in parasitized bivalves by considering ex-situ controlled parasitism induction along with varying environmental conditions. In view of this, efforts must be directed towards minimizing pea crab's outbreaks, especially in cultivated shellfish farms. Future studies should elucidate molecular mechanisms involved in the immunocompetence of P. malabarica, hosting the parasitic pea crabs.}, }
@article {pmid28888836, year = {2018}, author = {Macrander, JC and Dimond, JL and Bingham, BL and Reitzel, AM}, title = {Transcriptome sequencing and characterization of Symbiodinium muscatinei and Elliptochloris marina, symbionts found within the aggregating sea anemone Anthopleura elegantissima.}, journal = {Marine genomics}, volume = {37}, number = {}, pages = {82-91}, doi = {10.1016/j.margen.2017.08.010}, pmid = {28888836}, issn = {1876-7478}, mesh = {Animals ; Chlorophyta/*genetics ; Dinoflagellida/*genetics ; *Genetic Variation ; Phylogeny ; Sea Anemones/physiology ; *Symbiosis ; *Transcriptome ; }, abstract = {There is a growing body of literature using transcriptomic data to study how tropical cnidarians and their photosynthetic endosymbionts respond to environmental stressors and participate in metabolic exchange. Despite these efforts, our understanding of how essential genes function to facilitate symbiosis establishment and maintenance remains limited. The inclusion of taxonomically and ecologically diverse endosymbionts will enhance our understanding of these interactions. Here we characterize the transcriptomes of two very different symbionts found within the temperate sea anemone Anthopleura elegantissima: the chlorophyte Elliptochloris marina and the dinoflagellate Symbiodinium muscatinei. We use a multi-level approach to assess the diversity of genes found across S. muscatinei and E. marina transcriptomes, and compare their overall protein domains with other dinoflagellates and chlorophytes. Our analysis identified several genes that are potentially involved in mitigating stress response (e.g., heat shock proteins pathways for mediating reactive oxygen species) and metabolic exchange (e.g., ion transporters). Finally, we show that S. muscatinei and other Symbiodinium strains are equipped with a high salt peridinin-chl-protein (HSPCP) gene previously identified only in free-living dinoflagellates. The addition of these transcriptomes to the cnidarian-symbiont molecular toolkit will aid in understanding how these vitally important symbiotic relationships are established and maintained across a variety of environmental conditions.}, }
@article {pmid28878861, year = {2017}, author = {Ponnudurai, R and Sayavedra, L and Kleiner, M and Heiden, SE and Thürmer, A and Felbeck, H and Schlüter, R and Sievert, SM and Daniel, R and Schweder, T and Markert, S}, title = {Genome sequence of the sulfur-oxidizing Bathymodiolus thermophilus gill endosymbiont.}, journal = {Standards in genomic sciences}, volume = {12}, number = {}, pages = {50}, pmid = {28878861}, issn = {1944-3277}, abstract = {Bathymodiolus thermophilus, a mytilid mussel inhabiting the deep-sea hydrothermal vents of the East Pacific Rise, lives in symbiosis with chemosynthetic Gammaproteobacteria within its gills. The intracellular symbiont population synthesizes nutrients for the bivalve host using the reduced sulfur compounds emanating from the vents as energy source. As the symbiont is uncultured, comprehensive and detailed insights into its metabolism and its interactions with the host can only be obtained from culture-independent approaches such as genomics and proteomics. In this study, we report the first draft genome sequence of the sulfur-oxidizing symbiont of B. thermophilus, here tentatively named Candidatus Thioglobus thermophilus. The draft genome (3.1 Mb) harbors 3045 protein-coding genes. It revealed pathways for the use of sulfide and thiosulfate as energy sources and encodes the Calvin-Benson-Bassham cycle for CO2 fixation. Enzymes required for the synthesis of the tricarboxylic acid cycle intermediates oxaloacetate and succinate were absent, suggesting that these intermediates may be substituted by metabolites from external sources. We also detected a repertoire of genes associated with cell surface adhesion, bacteriotoxicity and phage immunity, which may perform symbiosis-specific roles in the B. thermophilus symbiosis.}, }
@article {pmid28878066, year = {2017}, author = {Gebiola, M and Giorgini, M and Kelly, SE and Doremus, MR and Ferree, PM and Hunter, MS}, title = {Cytological analysis of cytoplasmic incompatibility induced by Cardinium suggests convergent evolution with its distant cousin Wolbachia.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1862}, pages = {}, pmid = {28878066}, issn = {1471-2954}, mesh = {Aneuploidy ; Animals ; *Cytophagaceae ; Cytoplasm/*microbiology ; Female ; Male ; Mitosis ; Reproduction ; Symbiosis ; Wasps/*microbiology ; Wolbachia ; }, abstract = {Cytoplasmic incompatibility (CI) is a conditional sterility in numerous arthropods that is caused by inherited, intracellular bacteria such as Wolbachia Matings between males carrying CI-inducing Wolbachia and uninfected females, or between males and females infected with different Wolbachia strains, result in progeny that die during very early embryogenesis. Multiple studies in diploid (Drosophila) and haplodiploid (Nasonia) insects have shown that CI-Wolbachia cause a failure of the paternally derived chromatin from resolving into distinct chromosomes. This leads to the formation of chromatin bridges and other mitotic defects as early as the first mitotic division, and to early mitotic arrest. It is currently unknown if CI-inducing symbionts other than Wolbachia affect similar cellular processes. Here, we investigated CI caused by an unrelated bacterium, Cardinium, which naturally infects a parasitic wasp, Encarsia suzannae CI crosses in this host-symbiont system resulted in early mitotic defects including asynchrony of paternal and maternal chromosome sets as they enter mitosis, chromatin bridges and improper chromosome segregation that spanned across multiple mitotic divisions, triggering embryonic death through accumulated aneuploidy. We highlight small differences with CI-Wolbachia, which could be due to the underlying CI mechanism or host-specific effects. Our results suggest a convergence of CI-related cellular phenotypes between these two unrelated symbionts.}, }
@article {pmid28870618, year = {2017}, author = {Sato, N}, title = {Revisiting the theoretical basis of the endosymbiotic origin of plastids in the original context of Lynn Margulis on the origin of mitosing, eukaryotic cells.}, journal = {Journal of theoretical biology}, volume = {434}, number = {}, pages = {104-113}, doi = {10.1016/j.jtbi.2017.08.028}, pmid = {28870618}, issn = {1095-8541}, mesh = {Chromosomes ; DNA Replication ; History, 20th Century ; Mitosis/*genetics ; *Models, Theoretical ; Plastids ; *Symbiosis ; }, abstract = {Fifty years ago, Lynn Margulis proposed a comprehensive hypothesis on the origin of eukaryotic cells with an emphasis on the origin of mitosis. This hypothesis postulated that the eukaryotic cell is a composite of different parts as a result of the symbiosis of various different bacteria. In this hypothesis, she integrated previously proposed ideas that mitochondria and chloroplasts were descendants of endosymbionts that originated from aerobic bacteria and blue-green algae (now cyanobacteria), respectively. However, the major part of her hypothesis, which she believed to be original, was the origin of mitosis. The core of her postulate involved a chromosome partition mechanism dependent on DNA-microtubule binding, which originated from a hypothetical centriole-DNA complex, with an ability to replicate. Surprisingly, her complete lack of real experimental works in the cytoskeleton, cell motility, or paleontology did not prevent this 29-year-old junior scientist from assembling archival knowledge and constructing a narrative on the evolution of all organisms. Whether the centriole-DNA complex originated from a spirochete or not was a minor anecdote in this initial postulate. Unfortunately, this hypothesis on the origin of mitosis, which she believed to be a holistic unity, testable by experiments, was entirely refuted. Despite falsification of her original narrative as a whole, her success as a founder of endosymbiotic theory on the origin of mitochondria and chloroplasts is undoubted. We will discuss the reasons for her success in terms of the historical situation in the latter half of the 20th century.}, }
@article {pmid28864236, year = {2018}, author = {Haferkamp, I}, title = {Crossing the border - Solute entry into the chlamydial inclusion.}, journal = {International journal of medical microbiology : IJMM}, volume = {308}, number = {1}, pages = {41-48}, doi = {10.1016/j.ijmm.2017.08.006}, pmid = {28864236}, issn = {1618-0607}, mesh = {Animals ; Biological Transport ; Carrier Proteins/metabolism ; Chlamydiales/growth &amp; development/metabolism/*physiology ; Gram-Negative Bacterial Infections/*metabolism/microbiology ; Host-Pathogen Interactions ; Humans ; Inclusion Bodies/*metabolism/microbiology ; Nutrients/metabolism ; Vacuoles/metabolism ; }, abstract = {Chlamydiales comprise important human and animal pathogens as well as endosymbionts of amoebae. Generally, these obligate intracellular living bacteria are characterized by a biphasic developmental cycle, a reduced genome and a restricted metabolic capacity. Because of their metabolic impairment, Chlamydiales essentially rely on the uptake of diverse metabolites from their hosts. Chlamydiales thrive in a special compartment, the inclusion, and hence are surrounded by an additional membrane. Solutes might enter the inclusion through pores and open channels or by redirection of host vesicles, which fuse with the inclusion membrane and release their internal cargo. Recent investigations shed new light on the chlamydia-host interaction and identified an additional way for nutrient uptake into the inclusion. Proteome studies and targeting analyses identified chlamydial and host solute carriers in inclusions of Chlamydia trachomatis infected cells. These transporters are involved in the provision of UDP-glucose and biotin, and probably deliver further metabolites to the inclusion. By the controlled recruitment of specific solute carriers to the inclusion, the chlamydial resident thus can actively manipulate the metabolite availability and composition in the inclusion. This review summarizes recent findings and new ideas on carrier mediated solute uptake into the chlamydial inclusion in the context of the bacterial and host metabolism.}, }
@article {pmid30605507, year = {2017}, author = {Vera-Ponce de León, A and Ormeño-Orrillo, E and Ramírez-Puebla, ST and Rosenblueth, M and Degli Esposti, M and Martínez-Romero, J and Martínez-Romero, E}, title = {Candidatus Dactylopiibacterium carminicum, a Nitrogen-Fixing Symbiont of Dactylopius Cochineal Insects (Hemiptera: Coccoidea: Dactylopiidae).}, journal = {Genome biology and evolution}, volume = {9}, number = {9}, pages = {2237-2250}, pmid = {30605507}, issn = {1759-6653}, mesh = {Animals ; Female ; Genome, Bacterial ; Hemiptera/*microbiology ; *Nitrogen Fixation ; Ovary/microbiology ; Phylogeny ; Rhodocyclaceae/*classification/isolation &amp; purification ; *Symbiosis ; }, abstract = {The domesticated carmine cochineal Dactylopius coccus (scale insect) has commercial value and has been used for more than 500 years for natural red pigment production. Besides the domesticated cochineal, other wild Dactylopius species such as Dactylopius opuntiae are found in the Americas, all feeding on nutrient poor sap from native cacti. To compensate nutritional deficiencies, many insects harbor symbiotic bacteria which provide essential amino acids or vitamins to their hosts. Here, we characterized a symbiont from the carmine cochineal insects, Candidatus Dactylopiibacterium carminicum (betaproteobacterium, Rhodocyclaceae family) and found it in D. coccus and in D. opuntiae ovaries by fluorescent in situ hybridization, suggesting maternal inheritance. Bacterial genomes recovered from metagenomic data derived from whole insects or tissues both from D. coccus and from D. opuntiae were around 3.6 Mb in size. Phylogenomics showed that dactylopiibacteria constituted a closely related clade neighbor to nitrogen fixing bacteria from soil or from various plants including rice and other grass endophytes. Metabolic capabilities were inferred from genomic analyses, showing a complete operon for nitrogen fixation, biosynthesis of amino acids and vitamins and putative traits of anaerobic or microoxic metabolism as well as genes for plant interaction. Dactylopiibacterium nif gene expression and acetylene reduction activity detecting nitrogen fixation were evidenced in D. coccus hemolymph and ovaries, in congruence with the endosymbiont fluorescent in situ hybridization location. Dactylopiibacterium symbionts may compensate for the nitrogen deficiency in the cochineal diet. In addition, this symbiont may provide essential amino acids, recycle uric acid, and increase the cochineal life span.}, }
@article {pmid28855622, year = {2017}, author = {Fan, W and Guo, W and Van Etten, JL and Mower, JP}, title = {Multiple origins of endosymbionts in Chlorellaceae with no reductive effects on the plastid or mitochondrial genomes.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {10101}, pmid = {28855622}, issn = {2045-2322}, support = {P30 GM103509/GM/NIGMS NIH HHS/United States ; }, mesh = {Chlorella/genetics ; Chlorophyta/*genetics ; Evolution, Molecular ; *Genome, Mitochondrial ; *Genome, Plastid ; Introns ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Ancient endosymbiotic relationships have led to extreme genomic reduction in many bacterial and eukaryotic algal endosymbionts. Endosymbionts in more recent and/or facultative relationships can also experience genomic reduction to a lesser extent, but little is known about the effects of the endosymbiotic transition on the organellar genomes of eukaryotes. To understand how the endosymbiotic lifestyle has affected the organellar genomes of photosynthetic green algae, we generated the complete plastid genome (plastome) and mitochondrial genome (mitogenome) sequences from three green algal endosymbionts (Chlorella heliozoae, Chlorella variabilis and Micractinium conductrix). The mitogenomes and plastomes of the three newly sequenced endosymbionts have a standard set of genes compared with free-living trebouxiophytes, providing no evidence for functional genomic reduction. Instead, their organellar genomes are generally larger and more intron rich. Intron content is highly variable among the members of Chlorella, suggesting very high rates of gain and/or loss of introns during evolution. Phylogenetic analysis of plastid and mitochondrial genes demonstrated that the three endosymbionts do not form a monophyletic group, indicating that the endosymbiotic lifestyle has evolved multiple times in Chlorellaceae. In addition, M. conductrix is deeply nested within the Chlorella clade, suggesting that taxonomic revision is needed for one or both genera.}, }
@article {pmid28855333, year = {2017}, author = {MacLean, AM and Bravo, A and Harrison, MJ}, title = {Plant Signaling and Metabolic Pathways Enabling Arbuscular Mycorrhizal Symbiosis.}, journal = {The Plant cell}, volume = {29}, number = {10}, pages = {2319-2335}, pmid = {28855333}, issn = {1532-298X}, mesh = {Gene Expression Regulation, Plant ; Mycorrhizae/*physiology ; Plant Proteins/metabolism ; Plant Roots/metabolism/microbiology ; Plants/metabolism/microbiology ; Signal Transduction ; Symbiosis/*physiology ; }, abstract = {Plants have lived in close association with arbuscular mycorrhizal (AM) fungi for over 400 million years. Today, this endosymbiosis occurs broadly in the plant kingdom where it has a pronounced impact on plant mineral nutrition. The symbiosis develops deep within the root cortex with minimal alterations in the external appearance of the colonized root; however, the absence of macroscopic alterations belies the extensive signaling, cellular remodeling, and metabolic alterations that occur to enable accommodation of the fungal endosymbiont. Recent research has revealed the involvement of a novel N-acetyl glucosamine transporter and an alpha/beta-fold hydrolase receptor at the earliest stages of AM symbiosis. Calcium channels required for symbiosis signaling have been identified, and connections between the symbiosis signaling pathway and key transcriptional regulators that direct AM-specific gene expression have been established. Phylogenomics has revealed the existence of genes conserved for AM symbiosis, providing clues as to how plant cells fine-tune their biology to enable symbiosis, and an exciting coalescence of genome mining, lipid profiling, and tracer studies collectively has led to the conclusion that AM fungi are fatty acid auxotrophs and that plants provide their fungal endosymbionts with fatty acids. Here, we provide an overview of the molecular program for AM symbiosis and discuss these recent advances.}, }
@article {pmid28855327, year = {2017}, author = {Sullivan, W}, title = {Wolbachia, bottled water, and the dark side of symbiosis.}, journal = {Molecular biology of the cell}, volume = {28}, number = {18}, pages = {2343-2346}, pmid = {28855327}, issn = {1939-4586}, mesh = {Animals ; Humans ; Symbiosis/*physiology ; }, abstract = {Obligate endosymbiosis is operationally defined when loss or removal of the endosymbiont from the host results in the death of both. Whereas these relationships are typically viewed as mutualistic, molecular and cellular analysis reveals numerous instances in which these symbiotic relationships are established by alternative, nonmutualistic strategies. The endosymbiont usurps or integrates into core host processes, creating a need where none previously existed. Here I discuss examples of these addictive symbiotic relationships and how they are a likely outcome of all complex evolving systems.}, }
@article {pmid28854679, year = {2017}, author = {Gualtieri, L and Nugnes, F and Nappo, AG and Gebiola, M and Bernardo, U}, title = {Life inside a gall: closeness does not favour horizontal transmission of Rickettsia between a gall wasp and its parasitoid.}, journal = {FEMS microbiology ecology}, volume = {93}, number = {7}, pages = {}, doi = {10.1093/femsec/fix087}, pmid = {28854679}, issn = {1574-6941}, mesh = {Animals ; Parthenogenesis/physiology ; Phylogeny ; Rickettsia/*classification/isolation &amp; purification ; Symbiosis/*physiology ; Wasps/*microbiology ; }, abstract = {The incidence of horizontal transmission as a route for spreading symbiont infections is still being debated, but a common view is that horizontal transfers require intimate between-species relationships. Here we study a system that meets ideal requirements for horizontal transmission: the gall wasp Leptocybe invasa and its parasitoid Quadrastichus mendeli (Hymenoptera: Eulophidae). These wasps belong to the same subfamily, spend most of their lives inside the same minute gall and are both infected by Rickettsia, a maternally inherited endosymbiotic bacteria that infects several arthropods, sometimes manipulating their reproduction, like inducing thelytokous parthenogenesis in L. invasa. Despite intimate contact, close phylogenetic relationship and the parasitoid's host specificity, we show that host and parasitoid do not share the same Rickettsia. We provide indirect evidence that Rickettsia infecting Q. mendeli may be inducing thelytokous parthenogenesis, as the symbiont is densely present in the reproductive apparatus and is vertically transmitted. Phylogenetic analyses based on 16S and gltA placed this symbiont in the leech group. The confirmed and presumed parthenogenesis-inducing Rickettsia discovered so far only infect eulophid wasps, and belong to three different groups, suggesting multiple independent evolution of the parthenogenesis inducing phenotype. We also show some degree of cospeciation between Rickettsia and their eulophid hosts.}, }
@article {pmid28846455, year = {2017}, author = {Bock, R}, title = {Witnessing Genome Evolution: Experimental Reconstruction of Endosymbiotic and Horizontal Gene Transfer.}, journal = {Annual review of genetics}, volume = {51}, number = {}, pages = {1-22}, doi = {10.1146/annurev-genet-120215-035329}, pmid = {28846455}, issn = {1545-2948}, mesh = {Cell Nucleus/genetics/metabolism ; Chloroplasts/genetics/metabolism ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Genetic Speciation ; *Genome, Plant ; Genomics/methods ; Mitochondria/genetics/metabolism ; Plant Cells/metabolism ; Plants/*genetics ; Symbiosis/*genetics ; }, abstract = {Present day mitochondria and plastids (chloroplasts) evolved from formerly free-living bacteria that were acquired through endosymbiosis more than a billion years ago. Conversion of the bacterial endosymbionts into cell organelles involved the massive translocation of genetic material from the organellar genomes to the nucleus. The development of transformation technologies for organellar genomes has made it possible to reconstruct this endosymbiotic gene transfer in laboratory experiments and study the mechanisms involved. Recently, the horizontal transfer of genetic information between organisms has also become amenable to experimental investigation. It led to the discovery of horizontal genome transfer as an asexual process generating new species and new combinations of nuclear and organellar genomes. This review describes experimental approaches towards studying endosymbiotic and horizontal gene transfer processes, discusses the new knowledge gained from these approaches about both the evolutionary significance of gene transfer and the underlying molecular mechanisms, and highlights exciting possibilities to exploit gene and genome transfer in biotechnology and synthetic biology.}, }
@article {pmid28843439, year = {2017}, author = {Suggett, DJ and Warner, ME and Leggat, W}, title = {Symbiotic Dinoflagellate Functional Diversity Mediates Coral Survival under Ecological Crisis.}, journal = {Trends in ecology &amp; evolution}, volume = {32}, number = {10}, pages = {735-745}, doi = {10.1016/j.tree.2017.07.013}, pmid = {28843439}, issn = {1872-8383}, mesh = {Animals ; *Anthozoa ; *Climate Change ; *Coral Reefs ; *Dinoflagellida ; Phylogeny ; Symbiosis ; }, abstract = {Coral reefs have entered an era of 'ecological crisis' as climate change drives catastrophic reef loss worldwide. Coral growth and stress susceptibility are regulated by their endosymbiotic dinoflagellates (genus Symbiodinium). The phylogenetic diversity of Symbiodinium frequently corresponds to patterns of coral health and survival, but knowledge of functional diversity is ultimately necessary to reconcile broader ecological success over space and time. We explore here functional traits underpinning the complex biology of Symbiodinium that spans free-living algae to coral endosymbionts. In doing so we propose a mechanistic framework integrating the primary traits of resource acquisition and utilisation as a means to explain Symbiodinium functional diversity and to resolve the role of Symbiodinium in driving the stability of coral reefs under an uncertain future.}, }
@article {pmid28842472, year = {2017}, author = {Kraus, F and Ryan, MT}, title = {The constriction and scission machineries involved in mitochondrial fission.}, journal = {Journal of cell science}, volume = {130}, number = {18}, pages = {2953-2960}, doi = {10.1242/jcs.199562}, pmid = {28842472}, issn = {1477-9137}, mesh = {Actins/metabolism ; Animals ; Endoplasmic Reticulum/metabolism ; Humans ; Lipids/chemistry ; *Mitochondrial Dynamics ; Mitochondrial Proteins/metabolism ; Models, Biological ; }, abstract = {A key event in the evolution of eukaryotic cells was the engulfment of an aerobic bacterium by a larger anaerobic archaebacterium, leading to a close relationship between the host and the newly formed endosymbiont. Mitochondria, originating from this event, have evolved to be the main place of cellular ATP production. Maintaining elements of their independence, mitochondria undergo growth and division in the cell, thereby ensuring that new daughter cells inherit a mitochondrial complement. Mitochondrial division is also important for other processes, including quality control, mitochondrial (mt)DNA inheritance, transport and cell death. However, unlike bacterial fission, which uses a dynamin-related protein to constrict the membrane at its inner face, mitochondria use dynamin and dynamin-related proteins to constrict the outer membrane from the cytosolic face. In this Review, we summarize the role of proteins from the dynamin superfamily in mitochondrial division. This includes recent findings highlighting that dynamin-2 (Dnm2) is involved in mitochondrial scission, which led to the reappraisal of the role of dynamin-related protein 1 (Drp1; also known as Dnm1l) and its outer membrane adaptors as components of the mitochondrial constriction machinery along with ER components and actin.}, }
@article {pmid28841917, year = {2017}, author = {Almeida, F and Suesdek, L}, title = {Effects of Wolbachia on ovarian apoptosis in Culex quinquefasciatus (Say, 1823) during the previtellogenic and vitellogenic periods.}, journal = {Parasites &amp; vectors}, volume = {10}, number = {1}, pages = {398}, pmid = {28841917}, issn = {1756-3305}, mesh = {Animals ; *Apoptosis ; Culex/*microbiology/*physiology ; Female ; Microscopy, Confocal ; Oocytes/microbiology/pathology ; Oogenesis ; Ovary/cytology/microbiology/ultrastructure ; Vitellogenesis ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Apoptosis is programmed cell death that ordinarily occurs in ovarian follicular cells in various organisms. In the best-studied holometabolous insect, Drosophila, this kind of cell death occurs in all three cell types found in the follicles, sometimes leading to follicular atresia and egg degeneration. On the other hand, egg development, quantity and viability in the mosquito Culex quinquefasciatus are disturbed by the infection with the endosymbiont Wolbachia. Considering that Wolbachia alters reproductive traits, we hypothesised that such infection would also alter the apoptosis in the ovarian cells of this mosquito. The goal of this study was to comparatively describe the occurrence of apoptosis in Wolbachia-infected and uninfected ovaries of Cx. quinquefasciatus during oogenesis and vitellogenesis. For this, we recorded under confocal microscopy the occurrence of apoptosis in all three cell types of the ovarian follicle. In the first five days of adult life we observed oogenesis and, after a blood meal, the initiation step of vitellogenesis.<br><br>RESULTS: Apoptoses in follicular cells were found at all observation times during both oogenesis and vitellogenesis, and less commonly in nurse cells and the oocyte, as well as in atretic follicles. Our results suggested that apoptosis in follicular cells occurred in greater numbers in infected mosquitoes than in uninfected ones during the second and third days of adult life and at the initiation step of vitellogenesis.<br><br>CONCLUSIONS: The presence of Wolbachia leads to an increase of apoptosis occurrence in the ovaries of Cx. quinquefasciatus. Future studies should investigate if this augmented apoptosis frequency is the cause of the reduction in the number of eggs laid by Wolbachia-infected females. Follicular atresia is first reported in the previtellogenic period of oogenesis. Our findings may have implications for the use of Wolbachia as a mosquito and pathogens control strategy.}, }
@article {pmid28841224, year = {2017}, author = {Dennis, AB and Patel, V and Oliver, KM and Vorburger, C}, title = {Parasitoid gene expression changes after adaptation to symbiont-protected hosts.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {11}, pages = {2599-2617}, doi = {10.1111/evo.13333}, pmid = {28841224}, issn = {1558-5646}, mesh = {*Adaptation, Physiological ; Animals ; Aphids/genetics/microbiology/*parasitology ; Enterobacteriaceae/genetics/pathogenicity ; *Evolution, Molecular ; Female ; *Genes, Insect ; Host-Parasite Interactions/*genetics ; Life History Traits ; Oviposition ; *Symbiosis ; Transcriptome ; Wasps/*genetics/pathogenicity ; }, abstract = {Reciprocal selection between aphids, their protective endosymbionts, and the parasitoid wasps that prey upon them offers an opportunity to study the basis of their coevolution. We investigated adaptation to symbiont-conferred defense by rearing the parasitoid wasp Lysiphlebus fabarum on aphids (Aphis fabae) possessing different defensive symbiont strains (Hamiltonella defensa). After ten generations of experimental evolution, wasps showed increased abilities to parasitize aphids possessing the H. defensa strain they evolved with, but not aphids possessing the other strain. We show that the two symbiont strains encode different toxins, potentially creating different targets for counter-adaptation. Phenotypic and behavioral comparisons suggest that neither life-history traits nor oviposition behavior differed among evolved parasitoid lineages. In contrast, comparative transcriptomics of adult female wasps identified a suite of differentially expressed genes among lineages, even when reared in a common, symbiont-free, aphid host. In concurrence with the specificity of each parasitoid lineages' infectivity, most differentially expressed parasitoid transcripts were also lineage-specific. These transcripts are enriched with putative venom toxins and contain highly expressed, potentially defensive viral particles. Together, these results suggest that wild populations of L. fabarum employ a complicated offensive arsenal with sufficient genetic variation for wasps to adapt rapidly and specifically to their hosts' microbial defenses.}, }
@article {pmid28840787, year = {2018}, author = {Basu, S and Varsani, S and Louis, J}, title = {Altering Plant Defenses: Herbivore-Associated Molecular Patterns and Effector Arsenal of Chewing Herbivores.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {31}, number = {1}, pages = {13-21}, doi = {10.1094/MPMI-07-17-0183-FI}, pmid = {28840787}, issn = {0894-0282}, mesh = {Animals ; Herbivory/*physiology ; Insecta/physiology ; Mastication/*physiology ; Pathogen-Associated Molecular Pattern Molecules/*metabolism ; Plants/*immunology/*parasitology ; Symbiosis ; }, abstract = {Chewing herbivores, such as caterpillars and beetles, while feeding on the host plant, cause extensive tissue damage and release a wide array of cues to alter plant defenses. Consequently, the cues can have both beneficial and detrimental impacts on the chewing herbivores. Herbivore-associated molecular patterns (HAMPs) are molecules produced by herbivorous insects that aid them to elicit plant defenses leading to impairment of insect growth, while effectors suppress plant defenses and contribute to increased susceptibility to subsequent feeding by chewing herbivores. Besides secretions that originate from glands (e.g., saliva) and fore- and midgut regions (e.g., oral secretions) of chewing herbivores, recent studies have shown that insect frass and herbivore-associated endosymbionts also play a critical role in modulating plant defenses. In this review, we provide an update on a growing body of literature that discusses the chewing insect HAMPs and effectors and the mechanisms by which they modulate host defenses. Novel "omic" approaches and availability of new tools will help researchers to move forward this discipline by identifying and characterizing novel insect HAMPs and effectors and how these herbivore-associated cues are perceived by host plant receptors.}, }
@article {pmid28839179, year = {2017}, author = {Razzak, MA and Lee, DW and Yoo, YJ and Hwang, I}, title = {Evolution of rubisco complex small subunit transit peptides from algae to plants.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {9279}, pmid = {28839179}, issn = {2045-2322}, mesh = {Amino Acid Motifs ; Amino Acid Sequence ; Arabidopsis/genetics ; Chlorophyta/*genetics ; Chloroplast Proteins/chemistry/*genetics ; *Evolution, Molecular ; Peptides/chemistry/*genetics ; Plants/*genetics ; Ribulose-Bisphosphate Carboxylase/chemistry/*genetics ; }, abstract = {Chloroplasts evolved from a free-living cyanobacterium acquired by the ancestor of all photosynthetic eukaryotes, including algae and plants, through a single endosymbiotic event. During endosymbiotic conversion, the majority of genes in the endosymbiont were transferred to the host nucleus and many of the proteins encoded by these genes must therefore be transported into the chloroplast after translation in the cytosol. Chloroplast-targeted proteins contain a targeting signal, named the transit peptide (TP), at the N-terminus. However, the evolution of TPs is not well understood. In this study, TPs from RbcS (rubisco small subunit) were compared between lower and higher eukaryotes. Chlamydomonas reinhardtii RbcS (CrRbcS) TP was non-functional in Arabidopsis. However, inclusion of a critical sequence motif, FP-RK, from Arabidopsis thaliana RbcS (AtRbcS) TP allowed CrRbcS TP to deliver proteins into plant chloroplasts. The position of the FP-RK motif in CrRbcS TP was critical for function. The QMMVW sequence motif in CrRbcS TP was crucial for its transport activity in plants. CrRbcS TPs containing additional plant motifs remained functional in C. reinhardtii. These results suggest that TPs evolved by acquiring additional sequence motifs to support protein targeting to chloroplasts during evolution of land plants from algae.}, }
@article {pmid28837612, year = {2017}, author = {Challacombe, JF and Pillai, S and Kuske, CR}, title = {Shared features of cryptic plasmids from environmental and pathogenic Francisella species.}, journal = {PloS one}, volume = {12}, number = {8}, pages = {e0183554}, pmid = {28837612}, issn = {1932-6203}, mesh = {Animals ; Francisella/classification/*genetics ; Humans ; Phylogeny ; *Plasmids ; }, abstract = {The Francisella genus includes several recognized species, additional potential species, and other representatives that inhabit a range of incredibly diverse ecological niches, but are not closely related to the named species. Francisella species have been obtained from a wide variety of clinical and environmental sources; documented species include highly virulent human and animal pathogens, fish pathogens, opportunistic human pathogens, tick endosymbionts, and free-living isolates inhabiting brackish water. While more than 120 Francisella genomes have been sequenced to date, only a few contain plasmids, and most of these appear to be cryptic, with unknown benefit to the host cell. We have identified several putative cryptic plasmids in the sequenced genomes of three Francisella novicida and F. novicida-like strains (TX07-6608, AZ06-7470, DPG_3A-IS) and two new Francisella species (F. frigiditurris CA97-1460 and F. opportunistica MA06-7296). These plasmids were compared to each other and to previously identified plasmids from other Francisella species. Some of the plasmids encoded functions potentially involved in replication, conjugal transfer and partitioning, environmental survival (transcriptional regulation, signaling, metabolism), and hypothetical proteins with no assignable functions. Genomic and phylogenetic comparisons of these new plasmids to the other known Francisella plasmids revealed some similarities that add to our understanding of the evolutionary relationships among the diverse Francisella species.}, }
@article {pmid28836704, year = {2017}, author = {Afanador, GA and Guerra, AJ and Swift, RP and Rodriguez, RE and Bartee, D and Matthews, KA and Schön, A and Freire, E and Freel Meyers, CL and Prigge, ST}, title = {A novel lipoate attachment enzyme is shared by Plasmodium and Chlamydia species.}, journal = {Molecular microbiology}, volume = {106}, number = {3}, pages = {439-451}, pmid = {28836704}, issn = {1365-2958}, support = {R56 AI065853/AI/NIAID NIH HHS/United States ; T32 GM008403/GM/NIGMS NIH HHS/United States ; R21 AI099704/AI/NIAID NIH HHS/United States ; P01 GM056550/GM/NIGMS NIH HHS/United States ; R01 GM084998/GM/NIGMS NIH HHS/United States ; F32 AI110028/AI/NIAID NIH HHS/United States ; R01 AI125534/AI/NIAID NIH HHS/United States ; }, mesh = {Chlamydia/metabolism ; Lipoylation/*genetics/*physiology ; Mitochondria/metabolism ; Mitochondrial Proteins/metabolism ; Nucleotidyltransferases ; Oxidation-Reduction ; Peptide Synthases/genetics ; Plasmodium/metabolism ; Plasmodium falciparum/genetics ; Protozoan Proteins/metabolism ; Sequence Alignment ; }, abstract = {Lipoate is an essential cofactor for enzymes that are important for central metabolism and other processes. In malaria parasites, scavenged lipoate from the human host is required for survival. The Plasmodium falciparum mitochondrion contains two enzymes (PfLipL1 and PfLipL2) that are responsible for activating mitochondrial proteins through the covalent attachment of lipoate (lipoylation). Lipoylation occurs via a novel redox-gated mechanism that remains poorly understood. We show that PfLipL1 functions as a redox switch that determines which downstream proteins will be activated. Based on the lipoate redox state, PfLipL1 either functions as a canonical lipoate ligase or as a lipoate activating enzyme which works in conjunction with PfLipL2. We demonstrate that PfLipL2 is a lipoyltransferase and is a member of a novel clade of lipoate attachment enzymes. We show that a LipL2 enzyme from Chlamydia trachomatis has similar activity, demonstrating conservation between intracellular pathogens from different phylogenetic kingdoms and supporting the hypothesis that an early ancestor of malaria parasites once contained a chlamydial endosymbiont. Redox-dependent lipoylation may regulate processes such as central metabolism and oxidative defense pathways.}, }
@article {pmid28835914, year = {2017}, author = {Ochsenkühn, MA and Röthig, T and D'Angelo, C and Wiedenmann, J and Voolstra, CR}, title = {The role of floridoside in osmoadaptation of coral-associated algal endosymbionts to high-salinity conditions.}, journal = {Science advances}, volume = {3}, number = {8}, pages = {e1602047}, pmid = {28835914}, issn = {2375-2548}, support = {311179/ERC_/European Research Council/International ; }, mesh = {Adaptation, Physiological/*drug effects ; Animals ; Anthozoa/*physiology ; Carbohydrates/analysis ; Chromatography, Gas ; Coral Reefs ; Dinoflagellida/*physiology ; Glycerol/*analogs &amp; derivatives/pharmacology ; Metabolomics/methods ; *Osmolar Concentration ; *Salinity ; *Symbiosis ; }, abstract = {The endosymbiosis between Symbiodinium dinoflagellates and stony corals provides the foundation of coral reef ecosystems. The survival of these ecosystems is under threat at a global scale, and better knowledge is needed to conceive strategies for mitigating future reef loss. Environmental disturbance imposing temperature, salinity, and nutrient stress can lead to the loss of the Symbiodinium partner, causing so-called coral bleaching. Some of the most thermotolerant coral-Symbiodinium associations occur in the Persian/Arabian Gulf and the Red Sea, which also represent the most saline coral habitats. We studied whether Symbiodinium alter their metabolite content in response to high-salinity environments. We found that Symbiodinium cells exposed to high salinity produced high levels of the osmolyte 2-O-glycerol-α-d-galactopyranoside (floridoside), both in vitro and in their coral host animals, thereby increasing their capacity and, putatively, the capacity of the holobiont to cope with the effects of osmotic stress in extreme environments. Given that floridoside has been previously shown to also act as an antioxidant, this osmolyte may serve a dual function: first, to serve as a compatible organic osmolyte accumulated by Symbiodinium in response to elevated salinities and, second, to counter reactive oxygen species produced as a consequence of potential salinity and heat stress.}, }
@article {pmid28833928, year = {2017}, author = {Gomez-Polo, P and Ballinger, MJ and Lalzar, M and Malik, A and Ben-Dov, Y and Mozes-Daube, N and Perlman, SJ and Iasur-Kruh, L and Chiel, E}, title = {An exceptional family: Ophiocordyceps-allied fungus dominates the microbiome of soft scale insects (Hemiptera: Sternorrhyncha: Coccidae).}, journal = {Molecular ecology}, volume = {26}, number = {20}, pages = {5855-5868}, doi = {10.1111/mec.14332}, pmid = {28833928}, issn = {1365-294X}, mesh = {Animals ; Cyprus ; DNA, Fungal/genetics ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing ; Hypocreales/*classification/isolation &amp; purification ; Israel ; *Microbiota ; Phylogeny ; Ribosomes/genetics ; Sequence Analysis, DNA ; Spain ; Symbiosis ; }, abstract = {Hemipteran insects of the suborder Sternorrhyncha are plant sap feeders, where each family is obligately associated with a specific bacterial endosymbiont that produces essential nutrients lacking in the sap. Coccidae (soft scale insects) is the only major sternorrhynchan family in which obligate symbiont(s) have not been identified. We studied the microbiota in seven species from this family from Israel, Spain and Cyprus, by high-throughput sequencing of ribosomal genes, and found that no specific bacterium was prevalent and abundant in all the tested species. In contrast, an Ophiocordyceps-allied fungus sp.-a lineage widely known as entomopathogenic-was highly prevalent. All individuals of all the tested species carried this fungus. Phylogenetic analyses showed that the Ophiocordyceps-allied fungus from the coccids is closely related to fungi described from other hemipterans, and they appear to be monophyletic, although the phylogenies of the Ophiocordyceps-allied fungi and their hosts do not appear to be congruent. Microscopic observations show that the fungal cells are lemon-shaped, are distributed throughout the host's body and are present in the eggs, suggesting vertical transmission. Taken together, the results suggest that the Ophiocordyceps-allied fungus may be a primary symbiont of Coccidae-a major evolutionary shift from bacteria to fungi in the Sternorrhyncha, and an important example of fungal evolutionary lifestyle switch.}, }
@article {pmid28828570, year = {2017}, author = {McFadden, GI}, title = {The cryptomonad nucleomorph.}, journal = {Protoplasma}, volume = {254}, number = {5}, pages = {1903-1907}, pmid = {28828570}, issn = {1615-6102}, mesh = {Cell Nucleus/metabolism ; Cryptophyta/*metabolism ; Plastids/metabolism ; Rhodophyta/metabolism ; Symbiosis/physiology ; }, abstract = {The cryptomonad nucleomorph is a vestigial nucleus of a eukaryotic red alga engulfed by a phagotrophic protist and retained as a photosynthetic endosymbiont. This review recounts the initial discovery and subsequent characterisation of the cryptomonad nucleomorph focusing on the key role of Peter Sitte and his protégés in our understanding of secondary endosymbiosis to create complex plastids, one of the major transition events in the evolution of life on Earth.}, }
@article {pmid28828234, year = {2017}, author = {Sun, Y and Wang, M and Li, L and Zhou, L and Wang, X and Zheng, P and Yu, H and Li, C and Sun, S}, title = {Molecular identification of methane monooxygenase and quantitative analysis of methanotrophic endosymbionts under laboratory maintenance in Bathymodiolus platifrons from the South China Sea.}, journal = {PeerJ}, volume = {5}, number = {}, pages = {e3565}, pmid = {28828234}, issn = {2167-8359}, abstract = {Deep-sea mussels of the genus Bathymodiolus are numerically dominant macrofauna in many cold seep and hydrothermal vent ecosystems worldwide, and they depend on organic carbon produced by symbionts present in the epithelial cells of the gills. Although Bathymodiolus platifrons represents typical methanotrophic endosymbiosis, our understanding of molecular mechanisms of methane oxidization and carbon fixation is still in its infancy. Moreover, the laboratory maintenance of B. platifrons and the symbiont abundance dynamics during maintenance has not been reported. In the present study, we report the first systematic identification and phylogenetic analysis of three subunits of methane monooxygenase (pmoA, pmoB, and pmoC) obtained from the endosymbiotic bacteria found in B. platifrons. The coding sequences (CDS) of the three genes in the B. platifrons endosymbiont were 750, 1,245, and 753 bp, encoding 249, 414, and 250 amino acids, respectively. Sequence alignment and phylogenetic analysis revealed that the symbiont of B. platifrons belongs to the type I methanotrophs. In order to clarify the impact of environmental methane on symbiont abundance, a 34-day laboratory maintenance experiment was conducted in which B. platifrons individuals were acclimatized to methane-present and methane-absent environments. Symbiont abundance was evaluated by calculating the relative DNA content of the methane monooxygenase gene using quantitative real-time PCR. We found that symbiont quantity immediately decreased from its initial level, then continued to gradually decline during maintenance. At 24 and 34 days of maintenance, symbiont abundance in the methane-absent environment had significantly decreased compared to that in the methane-present environment, indicating that the maintenance of symbionts relies on a continuous supply of methane. Our electron microscopy results validated the qPCR analysis. This study enriches our knowledge of the molecular basis and the dynamic changes of the methanotrophic endosymbiosis in B. platifrons, and provides a feasible model biosystem for further investigation of methane oxidization, the carbon fixation process, and environmental adaptations of deep-sea mussels.}, }
@article {pmid28828177, year = {2017}, author = {Okude, G and Koga, R and Hayashi, T and Nishide, Y and Meng, XY and Nikoh, N and Miyanoshita, A and Fukatsu, T}, title = {Novel bacteriocyte-associated pleomorphic symbiont of the grain pest beetle Rhyzopertha dominica (Coleoptera: Bostrichidae).}, journal = {Zoological letters}, volume = {3}, number = {}, pages = {13}, pmid = {28828177}, issn = {2056-306X}, abstract = {BACKGROUND: The lesser grain borer Rhyzopertha dominica (Coleoptera: Bostrichidae) is a stored-product pest beetle. Early histological studies dating back to 1930s have reported that R. dominica and other bostrichid species possess a pair of oval symbiotic organs, called the bacteriomes, in which the cytoplasm is densely populated by pleomorphic symbiotic bacteria of peculiar rosette-like shape. However, the microbiological nature of the symbiont has remained elusive.<br><br>RESULTS: Here we investigated the bacterial symbiont of R. dominica using modern molecular, histological, and microscopic techniques. Whole-mount fluorescence in situ hybridization specifically targeting symbiotic bacteria consistently detected paired bacteriomes, in which the cytoplasm was full of pleomorphic bacterial cells, in the abdomen of adults, pupae and larvae, confirming previous histological descriptions. Molecular phylogenetic analysis identified the symbiont as a member of the Bacteroidetes, in which the symbiont constituted a distinct bacterial lineage allied to a variety of insect-associated endosymbiont clades, including Uzinura of diaspidid scales, Walczuchella of giant scales, Brownia of root mealybugs, Sulcia of diverse hemipterans, and Blattabacterium of roaches. The symbiont gene exhibited markedly AT-biased nucleotide composition and significantly accelerated molecular evolution, suggesting degenerative evolution of the symbiont genome. The symbiotic bacteria were detected in oocytes and embryos, confirming continuous host-symbiont association and vertical symbiont transmission in the host life cycle.<br><br>CONCLUSIONS: We demonstrate that the symbiont of R. dominica constitutes a novel bacterial lineage in the Bacteroidetes. We propose that reductive evolution of the symbiont genome may be relevant to the amorphous morphology of the bacterial cells via disruption of genes involved in cell wall synthesis and cell division. Genomic and functional aspects of the host-symbiont relationship deserve future studies.}, }
@article {pmid28826970, year = {2017}, author = {Aanen, DK and Eggleton, P}, title = {Symbiogenesis: Beyond the endosymbiosis theory?.}, journal = {Journal of theoretical biology}, volume = {434}, number = {}, pages = {99-103}, doi = {10.1016/j.jtbi.2017.08.001}, pmid = {28826970}, issn = {1095-8541}, mesh = {Animals ; *Biological Evolution ; Gastrointestinal Tract/anatomy &amp; histology ; Isoptera/anatomy &amp; histology ; *Phylogeny ; *Symbiosis ; }, abstract = {Symbiogenesis, literally 'becoming by living together', refers to the crucial role of symbiosis in major evolutionary innovations. The term usually is reserved for the major transition to eukaryotes and to photosynthesising eukaryotic algae and plants by endosymbiosis. However, in some eukaryote lineages endosymbionts have been lost secondarily, showing that symbiosis can trigger a major evolutionary innovation, even if symbionts were lost secondarily. This leads to the intriguing possibility that symbiosis has played a role in other major evolutionary innovations as well, even if not all extant representatives of such groups still have the symbiotic association. We evaluate this hypothesis for two innovations in termites (Termitoidae, also known informally as "Isoptera"): i) the role of flagellate gut protist symbionts in the transition to eusociality from cockroach-like ancestors, and ii) the role of non-gut associated symbionts in the transition to 'higher' termites, characterized by the absence of flagellate gut protists. In both cases we identify a crucial role for symbionts, even though in both cases, subsequently, symbionts were lost again in some lineages. We also briefly discuss additional possible examples of symbiogenesis. We conclude that symbiogenesis is more broadly applicable than just for the endosymbiotic origin of eukaryotes and photosynthetic eukaryotes, and may be a useful concept to acknowledge the important role of symbiosis for evolutionary innovation. However, we do not accept Lynn Margulis's view that symbiogenesis will lead to a paradigm shift from neoDarwinism, as the role of symbiosis in evolutionary change can be integrated with existing theory perfectly.}, }
@article {pmid28824885, year = {2017}, author = {Wilmes, M and Meier, K and Schiefer, A and Josten, M and Otten, CF and Klöckner, A and Henrichfreise, B and Vollmer, W and Hoerauf, A and Pfarr, K}, title = {AmiD Is a Novel Peptidoglycan Amidase in Wolbachia Endosymbionts of Drosophila melanogaster.}, journal = {Frontiers in cellular and infection microbiology}, volume = {7}, number = {}, pages = {353}, pmid = {28824885}, issn = {2235-2988}, support = {MR/N501840/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Amidohydrolases/genetics/immunology/*metabolism ; Amino Acid Sequence ; Animals ; Arthropods/microbiology ; Cell Wall/metabolism ; Drosophila melanogaster/*microbiology ; Genetic Vectors ; Mutagenesis, Site-Directed ; Nematoda/microbiology ; Peptidoglycan/*biosynthesis/immunology ; Sequence Analysis, Protein ; Symbiosis ; Uridine Diphosphate N-Acetylmuramic Acid/analogs &amp; derivatives/metabolism ; Wolbachia/*enzymology/genetics ; }, abstract = {Wolbachia endobacteria are obligate intracellular bacteria with a highly reduced genome infecting many arthropod and filarial species, in which they manipulate arthropod reproduction to increase their transmission and are essential for nematode development and survival. The Wolbachia genome encodes all enzymes required for the synthesis of the cell wall building block lipid II, although a peptidoglycan-like structure has not been detected. Despite the ability to synthesize lipid II, Wolbachia from arthropods and nematodes have only a subset of genes encoding enzymes involved in the periplasmic processing of lipid II and peptidoglycan recycling, with arthropods having two more than nematodes. We functionally analyzed the activity of the putative cell wall hydrolase AmiD from the Wolbachia endosymbiont of Drosophila melanogaster, an enzyme not encoded by the nematode endobacteria. Wolbachia AmiD has Zn[2+]-dependent amidase activity and cleaves intact peptidoglycan, monomeric lipid II and anhydromuropeptides, substrates that are generated during bacterial growth. AmiD may have been maintained in arthropod Wolbachia to avoid host immune recognition by degrading cell wall fragments in the periplasm. This is the first description of a wolbachial lipid II processing enzyme putatively expressed in the periplasm.}, }
@article {pmid28824050, year = {2017}, author = {Wang, R and Dong, L and Chen, Y and Qu, L and Wang, Q and Zhang, Y}, title = {Esteya Vermicola, a Nematophagous Fungus Attacking the Pine Wood Nematode, Harbors a Bacterial Endosymbiont Affiliated with Gammaproteobacteria.}, journal = {Microbes and environments}, volume = {32}, number = {3}, pages = {201-209}, pmid = {28824050}, issn = {1347-4405}, mesh = {Animals ; Gammaproteobacteria/classification/*isolation &amp; purification ; In Situ Hybridization, Fluorescence ; Nematoda/*microbiology ; Ophiostomatales/*pathogenicity ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Symbioses have played pivotal roles in biological, ecological, and evolutionary diversification. Symbiotic bacteria affect the biology of hosts in a number of ways. Esteya vermicola, an endoparasitic nematophagous fungus, has high infectivity in the pine wood nematode (PWN), which causes devastating ecological damage and economic losses in Asia and Europe. An integration of molecular, phylogenetic, and morphological analyses revealed that surface-sterilized E. vermicola with septate hyphae from different geographic locations harbor bacterial endosymbionts. 16S rRNA gene sequences from four fungal strains all clustered in a well-supported monophyletic clade that was the most closely related to Pseudomonas stutzeri and affiliated with Gammaproteobacteria. The existence and intracellular location of endobacteria was revealed by fluorescent in situ hybridization (FISH). Our results showed that endobacteria were coccoid, vertically inherited, as yet uncultured, and essential symbionts. Ultrastructural observations indicated that young and old endobacteria differed in cell size, cell wall thickness, and the degree of reproduction. The results of the present study provide a fundamental understanding of the endobacteria inside E. vermicola and raise questions regarding the impact of endobacteria on the biology, ecology, and evolution of their fungal host.}, }
@article {pmid28818037, year = {2017}, author = {Brüwer, JD and Agrawal, S and Liew, YJ and Aranda, M and Voolstra, CR}, title = {Association of coral algal symbionts with a diverse viral community responsive to heat shock.}, journal = {BMC microbiology}, volume = {17}, number = {1}, pages = {174}, pmid = {28818037}, issn = {1471-2180}, mesh = {Animals ; Anthozoa/*physiology/*virology ; Climate Change ; Cold Temperature ; Coral Reefs ; Darkness ; Dinoflagellida/physiology/virology ; Ecosystem ; Gene Expression Regulation, Viral ; Genes, Viral ; Hot Temperature ; Phylogeny ; Sequence Analysis, RNA ; *Symbiosis ; Viral Proteins/genetics/metabolism ; *Virus Physiological Phenomena ; Viruses/*classification/genetics ; }, abstract = {BACKGROUND: Stony corals provide the structural foundation of coral reef ecosystems and are termed holobionts given they engage in symbioses, in particular with photosynthetic dinoflagellates of the genus Symbiodinium. Besides Symbiodinium, corals also engage with bacteria affecting metabolism, immunity, and resilience of the coral holobiont, but the role of associated viruses is largely unknown. In this regard, the increase of studies using RNA sequencing (RNA-Seq) to assess gene expression provides an opportunity to elucidate viral signatures encompassed within the data via careful delineation of sequence reads and their source of origin.<br><br>RESULTS: Here, we re-analyzed an RNA-Seq dataset from a cultured coral symbiont (Symbiodinium microadriaticum, Clade A1) across four experimental treatments (control, cold shock, heat shock, dark shock) to characterize associated viral diversity, abundance, and gene expression. Our approach comprised the filtering and removal of host sequence reads, subsequent phylogenetic assignment of sequence reads of putative viral origin, and the assembly and analysis of differentially expressed viral genes. About 15.46% (123 million) of all sequence reads were non-host-related, of which <1% could be classified as archaea, bacteria, or virus. Of these, 18.78% were annotated as virus and comprised a diverse community consistent across experimental treatments. Further, non-host related sequence reads assembled into 56,064 contigs, including 4856 contigs of putative viral origin that featured 43 differentially expressed genes during heat shock. The differentially expressed genes included viral kinases, ubiquitin, and ankyrin repeat proteins (amongst others), which are suggested to help the virus proliferate and inhibit the algal host's antiviral response.<br><br>CONCLUSION: Our results suggest that a diverse viral community is associated with coral algal endosymbionts of the genus Symbiodinium, which prompts further research on their ecological role in coral health and resilience.}, }
@article {pmid28815055, year = {2017}, author = {Gerth, M and Wolf, R and Bleidorn, C and Richter, J and Sontowski, R and Unrein, J and Schlegel, M and Gruppe, A}, title = {Green lacewings (Neuroptera: Chrysopidae) are commonly associated with a diversity of rickettsial endosymbionts.}, journal = {Zoological letters}, volume = {3}, number = {}, pages = {12}, pmid = {28815055}, issn = {2056-306X}, abstract = {BACKGROUND: Bacterial symbionts transmitted from mothers to offspring are found in the majority of arthropods. Numerous studies have illustrated their wide impact on host biology, such as reproduction, behavior, and physiology One of the most common inherited symbionts is Rickettsia spp. (Alphaproteobacteria, Rickettsiales), which are found in about one-quarter of terrestrial arthropods, as well as in other invertebrates. In insect populations, Rickettsia spp. have been reported to cause reproductive modifications and fecundity-enhancing effects. Here, we investigated the incidence and genetic diversity of Rickettsia symbionts in green lacewings (Neuroptera, Chrysopidae), which are best known for their use as biological control agents against crop pests.<br><br>RESULTS: We screened 18 species of green lacewings and allies for Rickettsia and found the symbiont in 10 species, infecting 20-100% of sampled individuals. Strain characterization based on multiple bacterial loci revealed an unprecedented diversity of Rickettsia associated with lacewings, suggesting multiple independent acquisitions. Further, the detected Rickettsia lineages are restricted to a specific lineage (i.e., species or genus) of investigated lacewings, and these associations are stable across multiple sampled locations and points in time.<br><br>CONCLUSIONS: We conclude that Rickettsia-lacewing symbioses are common and evolutionarily stable. The role of these symbionts remains to be identified, but is potentially important to optimizing their use in biological pest control.}, }
@article {pmid28812709, year = {2017}, author = {Sun, J and Zhang, Y and Xu, T and Zhang, Y and Mu, H and Zhang, Y and Lan, Y and Fields, CJ and Hui, JHL and Zhang, W and Li, R and Nong, W and Cheung, FKM and Qiu, JW and Qian, PY}, title = {Adaptation to deep-sea chemosynthetic environments as revealed by mussel genomes.}, journal = {Nature ecology &amp; evolution}, volume = {1}, number = {5}, pages = {121}, doi = {10.1038/s41559-017-0121}, pmid = {28812709}, issn = {2397-334X}, abstract = {Hydrothermal vents and methane seeps are extreme deep-sea ecosystems that support dense populations of specialized macro-benthos such as mussels. But the lack of genome information hinders the understanding of the adaptation of these animals to such inhospitable environments. Here we report the genomes of a deep-sea vent/seep mussel (Bathymodiolus platifrons) and a shallow-water mussel (Modiolus philippinarum). Phylogenetic analysis shows that these mussel species diverged approximately 110.4 million years ago. Many gene families, especially those for stabilizing protein structures and removing toxic substances from cells, are highly expanded in B. platifrons, indicating adaptation to extreme environmental conditions. The innate immune system of B. platifrons is considerably more complex than that of other lophotrochozoan species, including M. philippinarum, with substantial expansion and high expression levels of gene families that are related to immune recognition, endocytosis and caspase-mediated apoptosis in the gill, revealing presumed genetic adaptation of the deep-sea mussel to the presence of its chemoautotrophic endosymbionts. A follow-up metaproteomic analysis of the gill of B. platifrons shows methanotrophy, assimilatory sulfate reduction and ammonia metabolic pathways in the symbionts, providing energy and nutrients, which allow the host to thrive. Our study of the genomic composition allowing symbiosis in extremophile molluscs gives wider insights into the mechanisms of symbiosis in other organisms such as deep-sea tubeworms and giant clams.}, }
@article {pmid28808007, year = {2017}, author = {Sánchez-Baracaldo, P and Raven, JA and Pisani, D and Knoll, AH}, title = {Early photosynthetic eukaryotes inhabited low-salinity habitats.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {37}, pages = {E7737-E7745}, pmid = {28808007}, issn = {1091-6490}, mesh = {Bayes Theorem ; Biological Evolution ; Chlorophyta/genetics ; Chloroplasts/*metabolism/*physiology ; Cyanobacteria/*genetics/*metabolism ; Ecosystem ; Eukaryota/metabolism ; Evolution, Molecular ; Genome, Chloroplast/genetics ; Origin of Life ; Photosynthesis/physiology ; Phylogeny ; Phytoplankton/genetics ; Plastids/genetics ; Rhodophyta/genetics ; Salinity ; Symbiosis/genetics ; }, abstract = {The early evolutionary history of the chloroplast lineage remains an open question. It is widely accepted that the endosymbiosis that established the chloroplast lineage in eukaryotes can be traced back to a single event, in which a cyanobacterium was incorporated into a protistan host. It is still unclear, however, which Cyanobacteria are most closely related to the chloroplast, when the plastid lineage first evolved, and in what habitats this endosymbiotic event occurred. We present phylogenomic and molecular clock analyses, including data from cyanobacterial and chloroplast genomes using a Bayesian approach, with the aim of estimating the age for the primary endosymbiotic event, the ages of crown groups for photosynthetic eukaryotes, and the independent incorporation of a cyanobacterial endosymbiont by Paulinella Our analyses include both broad taxon sampling (119 taxa) and 18 fossil calibrations across all Cyanobacteria and photosynthetic eukaryotes. Phylogenomic analyses support the hypothesis that the chloroplast lineage diverged from its closet relative Gloeomargarita, a basal cyanobacterial lineage, ∼2.1 billion y ago (Bya). Our analyses suggest that the Archaeplastida, consisting of glaucophytes, red algae, green algae, and land plants, share a common ancestor that lived ∼1.9 Bya. Whereas crown group Rhodophyta evolved in the Mesoproterozoic Era (1,600-1,000 Mya), crown groups Chlorophyta and Streptophyta began to radiate early in the Neoproterozoic (1,000-542 Mya). Stochastic mapping analyses indicate that the first endosymbiotic event occurred in low-salinity environments. Both red and green algae colonized marine environments early in their histories, with prasinophyte green phytoplankton diversifying 850-650 Mya.}, }
@article {pmid28807085, year = {2018}, author = {Karimi, S and Izadi, H and Askari Seyahooei, M and Bagheri, A and Khodaygan, P}, title = {Variation in bacterial endosymbionts associated with the date palm hopper, Ommatissus lybicus populations.}, journal = {Bulletin of entomological research}, volume = {108}, number = {2}, pages = {271-281}, doi = {10.1017/S0007485317000633}, pmid = {28807085}, issn = {1475-2670}, mesh = {Animals ; Hemiptera/*microbiology ; Phylogeny ; Symbiosis ; }, abstract = {The date palm hopper, Ommatissus lybicus, is a key pest of the date palm, which is expected to be comprised of many allopatric populations. The current study was carried out to determine bacterial endosymbiont diversity in the different populations of this pest. Ten date palm hopper populations were collected from the main date palm growing regions in Iran and an additional four samples from Pakistan, Oman, Egypt and Tunisia for detection of primary and secondary endosymbionts using polymerase chain reaction (PCR) assay with their specific primers. The PCR products were directly sequenced and edited using SeqMan software. The consensus sequences were subjected to a BLAST similarity search. The results revealed the presence of 'Candidatus Sulcia muelleri' (primary endosymbiont) and Wolbachia, Arsenophonus and Enterobacter (secondary endosymbionts) in all populations. This assay failed to detect 'Candidatus Nasuia deltocephalinicola' and Serratia in these populations. 'Ca. S. muelleri' exhibited a 100% infection frequency in populations and Wolbachia, Arsenophonus and Enterobacter demonstrated 100, 93.04 and 97.39% infection frequencies, respectively. The infection rate of Arsenophonus and Enterobacter ranged from 75 to 100% and 62.5 to 100%, respectively, in different populations of the insect. The results demonstrated multiple infections by 'Ca. Sulcia muelleri', Wolbachia, Arsenophonus and Enterobacter in the populations and may suggest significant roles for these endosymbionts on date palm hopper population fitness. This study provides an insight to endosymbiont variation in the date palm hopper populations; however, further investigation is needed to examine how these endosymbionts may affect host fitness.}, }
@article {pmid28806979, year = {2017}, author = {Zachar, I and Szathmáry, E}, title = {Breath-giving cooperation: critical review of origin of mitochondria hypotheses : Major unanswered questions point to the importance of early ecology.}, journal = {Biology direct}, volume = {12}, number = {1}, pages = {19}, pmid = {28806979}, issn = {1745-6150}, mesh = {*Biological Evolution ; Energy Metabolism ; Genome, Mitochondrial ; *Mitochondria ; *Models, Biological ; Phagocytosis ; Phylogeny ; }, abstract = {UNLABELLED: The origin of mitochondria is a unique and hard evolutionary problem, embedded within the origin of eukaryotes. The puzzle is challenging due to the egalitarian nature of the transition where lower-level units took over energy metabolism. Contending theories widely disagree on ancestral partners, initial conditions and unfolding of events. There are many open questions but there is no comparative examination of hypotheses. We have specified twelve questions about the observable facts and hidden processes leading to the establishment of the endosymbiont that a valid hypothesis must address. We have objectively compared contending hypotheses under these questions to find the most plausible course of events and to draw insight on missing pieces of the puzzle. Since endosymbiosis borders evolution and ecology, and since a realistic theory has to comply with both domains' constraints, the conclusion is that the most important aspect to clarify is the initial ecological relationship of partners. Metabolic benefits are largely irrelevant at this initial phase, where ecological costs could be more disruptive. There is no single theory capable of answering all questions indicating a severe lack of ecological considerations. A new theory, compliant with recent phylogenomic results, should adhere to these criteria.<br><br>REVIEWERS: This article was reviewed by Michael W. Gray, William F. Martin and Purificaci&#xf3;n L&#xf3;pez-Garc&#xed;a.}, }
@article {pmid28805544, year = {2017}, author = {Jiménez-Zurdo, JI and Robledo, M}, title = {RNA silencing in plant symbiotic bacteria: Insights from a protein-centric view.}, journal = {RNA biology}, volume = {14}, number = {12}, pages = {1672-1677}, pmid = {28805544}, issn = {1555-8584}, mesh = {Bacteria/*genetics ; *Bacterial Physiological Phenomena ; Catalysis ; Endoribonucleases/genetics/metabolism ; Gene Expression Regulation, Bacterial ; *Gene Silencing ; Metals/metabolism ; Plants/*microbiology ; *RNA Interference ; RNA, Bacterial/genetics ; *Symbiosis ; }, abstract = {Extensive work in model enterobacteria has evidenced that the RNA chaperone Hfq and several endoribonucleases, such as RNase E or RNase III, serve pivotal roles in small RNA-mediated post-transcriptional silencing of gene expression. Characterization of these protein hubs commonly provide global functional and mechanistic insights into complex sRNA regulatory networks. The legume endosymbiont Sinorhizobium meliloti is a non-classical model bacterium with a very complex lifestyle in which riboregulation is expected to play important adaptive functions. Here, we discuss current knowledge about RNA silencing in S. meliloti from the perspective of the activity of Hfq and a recently discovered endoribonuclease (YbeY) exhibiting unprecedented catalytic versatility for the cleavage of single- and double-stranded RNA molecules.}, }
@article {pmid28805302, year = {2017}, author = {Pilgrim, J and Ander, M and Garros, C and Baylis, M and Hurst, GDD and Siozios, S}, title = {Torix group Rickettsia are widespread in Culicoides biting midges (Diptera: Ceratopogonidae), reach high frequency and carry unique genomic features.}, journal = {Environmental microbiology}, volume = {19}, number = {10}, pages = {4238-4255}, pmid = {28805302}, issn = {1462-2920}, support = {BBS/E/I/00001701/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BBS/E/I/00007036/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BBS/E/I/00007039/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Base Sequence ; Cell Wall/metabolism ; Ceratopogonidae/*microbiology ; Female ; Genome, Bacterial/*genetics ; Genomics ; Insect Vectors/*microbiology ; Lipopolysaccharides/genetics ; Pentose Phosphate Pathway/genetics ; Phylogeny ; Rickettsia/*classification/*genetics/isolation &amp; purification ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {There is increasing interest in the heritable bacteria of invertebrate vectors of disease as they present novel targets for control initiatives. Previous studies on biting midges (Culicoides spp.), known to transmit several RNA viruses of veterinary importance, have revealed infections with the endosymbiotic bacteria, Wolbachia and Cardinium. However, rickettsial symbionts in these vectors are underexplored. Here, we present the genome of a previously uncharacterized Rickettsia endosymbiont from Culicoides newsteadi (RiCNE). This genome presents unique features potentially associated with host invasion and adaptation, including genes for the complete non-oxidative phase of the pentose phosphate pathway, and others predicted to mediate lipopolysaccharides and cell wall modification. Screening of 414 Culicoides individuals from 29 Palearctic or Afrotropical species revealed that Rickettsia represent a widespread but previously overlooked association, reaching high frequencies in midge populations and present in 38% of the species tested. Sequence typing clusters the Rickettsia within the Torix group of the genus, a group known to infect several aquatic and hematophagous taxa. FISH analysis indicated the presence of Rickettsia bacteria in ovary tissue, indicating their maternal inheritance. Given the importance of biting midges as vectors, a key area of future research is to establish the impact of this endosymbiont on vector competence.}, }
@article {pmid28799248, year = {2018}, author = {DA Rocha, NO and Lambert, SM and Dias-Lima, AG and Julião, FS and Souza, BMPS}, title = {Molecular detection of Wolbachia pipientis in natural populations of sandfly vectors of Leishmania infantum in endemic areas: first detection in Lutzomyia longipalpis.}, journal = {Medical and veterinary entomology}, volume = {32}, number = {1}, pages = {111-114}, doi = {10.1111/mve.12255}, pmid = {28799248}, issn = {1365-2915}, mesh = {Animals ; Brazil ; Communicable Disease Control/methods ; Female ; Haplotypes ; Insect Vectors/*microbiology ; Leishmania infantum/physiology ; Leishmaniasis, Visceral/transmission ; Male ; Polymerase Chain Reaction ; Psychodidae/*microbiology ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, RNA ; Wolbachia/*isolation &amp; purification ; }, abstract = {A polymerase chain reaction-based method was used to screen sandflies for infection with Wolbachia (Rickettsiales: Rickettsiaceae), an intracellular bacterial endosymbiont found in many arthropods and filarial hosts. Positive results were obtained in five of 200 field-collected sandflies and were confirmed by sequencing. All sandflies were Lutzomyia longipalpis (Diptera: Psychodidae) captured in a region endemic for visceral leishmaniasis in Brazil. This is the first study to identify Wolbachia infection in this Lutzomyia species, which is the main vector of leishmaniasis in the study area. The low infection rate found in this study (2.5%), together with the lack of detection of Wolbachia in previous studies and the diversity found in the sequences analysed, suggests horizontal transmission to these sandflies.}, }
@article {pmid28791805, year = {2019}, author = {Mech, AM and Harper, SJ and Havill, NP and von Dohlen, CD and Burke, GR}, title = {Ecological factors influencing the beneficial endosymbionts of the hemlock woolly adelgid (Hemiptera: Adelgidae).}, journal = {Insect science}, volume = {26}, number = {1}, pages = {97-107}, doi = {10.1111/1744-7917.12514}, pmid = {28791805}, issn = {1744-7917}, mesh = {Animals ; Hemiptera/*microbiology ; Hot Temperature ; Pseudomonas/physiology ; Serratia/physiology ; Stress, Physiological ; Symbiosis ; Tsuga ; }, abstract = {Bacterial endosymbionts of sap-sucking insects provide their host with a number of beneficial qualities, including the supply of nutrition, defense against parasitoids, and protection from heat stress. Damage to these bacterial associates can therefore have a negative impact on the fitness of their insect host. We evaluated observational and experimental factors regarding the nonnative hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae) to help understand the roles of its three recently identified symbionts, including under heat stress conditions. The prevalence of A. tsugae's facultative symbiont (Serratia symbiotica) was examined at different spatial scales to determine how variable infection rates are for this symbiont. There was no significant difference found in infection rates between adelgids on a tree, within a plot, or within a state. However, significantly more adelgids in Georgia (95%) had S. symbiotica compared to those in New York (68%). Microsatellite genotyping of the adelgids found that this difference was most likely not the result of a second introduction of A. tsugae into eastern North America. Comparison of S. symbiotica proportions between first and fourth instars showed that symbiont absence did not affect the ability of A. tsugae to survive aestivation. Evaluations of symbiont densities within each adelgid found that when S. symbiotica was absent, the density of obligate symbionts was significantly higher. Exposure to heat stress (32.5 °C) was not consistently correlated with changes in symbiont densities over a 4-d period. Overall, we have shown that symbiont prevalence and densities vary within the broad population of A. tsugae in eastern North America, with potentially significant effects upon the ecology of this important pest.}, }
@article {pmid28789611, year = {2017}, author = {Rich, MK and Courty, PE and Roux, C and Reinhardt, D}, title = {Role of the GRAS transcription factor ATA/RAM1 in the transcriptional reprogramming of arbuscular mycorrhiza in Petunia hybrida.}, journal = {BMC genomics}, volume = {18}, number = {1}, pages = {589}, pmid = {28789611}, issn = {1471-2164}, mesh = {Gene Ontology ; Mutation ; Mycorrhizae/*genetics/*metabolism ; Petunia/*genetics/*metabolism ; Plant Proteins/*metabolism ; RNA, Messenger/genetics ; Transcription Factors/*metabolism ; *Transcription, Genetic ; }, abstract = {BACKGROUND: Development of arbuscular mycorrhiza (AM) requires a fundamental reprogramming of root cells for symbiosis. This involves the induction of hundreds of genes in the host. A recently identified GRAS-type transcription factor in Petunia hybrida, ATA/RAM1, is required for the induction of host genes during AM, and for morphogenesis of the fungal endosymbiont. To better understand the role of RAM1 in symbiosis, we set out to identify all genes that depend on activation by RAM1 in mycorrhizal roots.<br><br>RESULTS: We have carried out a transcript profiling experiment by RNAseq of mycorrhizal plants vs. non-mycorrhizal controls in wild type and ram1 mutants. The results show that the expression of early genes required for AM, such as the strigolactone biosynthetic genes and the common symbiosis signalling genes, is independent of RAM1. In contrast, genes that are involved at later stages of symbiosis, for example for nutrient exchange in cortex cells, require RAM1 for induction. RAM1 itself is highly induced in mycorrhizal roots together with many other transcription factors, in particular GRAS proteins.<br><br>CONCLUSION: Since RAM1 has previously been shown to be directly activated by the common symbiosis signalling pathway through CYCLOPS, we conclude that it acts as an early transcriptional switch that induces many AM-related genes, among them genes that are essential for the development of arbuscules, such as STR, STR2, RAM2, and PT4, besides hundreds of additional RAM1-dependent genes the role of which in symbiosis remains to be explored. Taken together, these results indicate that the defect in the morphogenesis of the fungal arbuscules in ram1 mutants may be an indirect consequence of functional defects in the host, which interfere with nutrient exchange and possibly other functions on which the fungus depends.}, }
@article {pmid28782202, year = {2017}, author = {Speijer, D}, title = {Evolution of peroxisomes illustrates symbiogenesis.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {39}, number = {9}, pages = {}, doi = {10.1002/bies.201700050}, pmid = {28782202}, issn = {1521-1878}, mesh = {Adaptation, Biological/physiology ; Animals ; Biological Evolution ; Eukaryotic Cells/metabolism/physiology ; Humans ; Mitochondria/metabolism/physiology ; Oxidation-Reduction ; Peroxisomes/*metabolism/*physiology ; Reactive Oxygen Species/metabolism ; Saccharomyces cerevisiae/physiology ; }, abstract = {Recently, the group of McBride reported a stunning observation regarding peroxisome biogenesis: newly born peroxisomes are hybrids of mitochondrial and ER-derived pre-peroxisomes. What was stunning? Studies performed with the yeast Saccharomyces cerevisiae had convincingly shown that peroxisomes are ER-derived, without indications for mitochondrial involvement. However, the recent finding using fibroblasts dovetails nicely with a mechanism inferred to be driving the eukaryotic invention of peroxisomes: reduction of mitochondrial reactive oxygen species (ROS) generation associated with fatty acid (FA) oxidation. This not only explains the mitochondrial involvement, but also its apparent absence in yeast. The latest results allow a reconstruction of the evolution of the yeast's highly derived metabolism and its limitations as a model organism in this instance. As I review here, peroxisomes are eukaryotic inventions reflecting mutual host endosymbiont adaptations: this is predicted by symbiogenetic theory, which states that the defining eukaryotic characteristics evolved as a result of mutual adaptations of two merging prokaryotes.}, }
@article {pmid28768886, year = {2017}, author = {Leles, SG and Mitra, A and Flynn, KJ and Stoecker, DK and Hansen, PJ and Calbet, A and McManus, GB and Sanders, RW and Caron, DA and Not, F and Hallegraeff, GM and Pitta, P and Raven, JA and Johnson, MD and Glibert, PM and Våge, S}, title = {Oceanic protists with different forms of acquired phototrophy display contrasting biogeographies and abundance.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1860}, pages = {}, pmid = {28768886}, issn = {1471-2954}, mesh = {Chloroplasts/physiology ; Eukaryota ; *Food Chain ; Oceans and Seas ; *Phototrophic Processes ; Plankton/*physiology ; Spatio-Temporal Analysis ; Symbiosis ; }, abstract = {This first comprehensive analysis of the global biogeography of marine protistan plankton with acquired phototrophy shows these mixotrophic organisms to be ubiquitous and abundant; however, their biogeography differs markedly between different functional groups. These mixotrophs, lacking a constitutive capacity for photosynthesis (i.e. non-constitutive mixotrophs, NCMs), acquire their phototrophic potential through either integration of prey-plastids or through endosymbiotic associations with photosynthetic microbes. Analysis of field data reveals that 40-60% of plankton traditionally labelled as (non-phototrophic) microzooplankton are actually NCMs, employing acquired phototrophy in addition to phagotrophy. Specialist NCMs acquire chloroplasts or endosymbionts from specific prey, while generalist NCMs obtain chloroplasts from a variety of prey. These contrasting functional types of NCMs exhibit distinct seasonal and spatial global distribution patterns. Mixotrophs reliant on 'stolen' chloroplasts, controlled by prey diversity and abundance, dominate in high-biomass areas. Mixotrophs harbouring intact symbionts are present in all waters and dominate particularly in oligotrophic open ocean systems. The contrasting temporal and spatial patterns of distribution of different mixotroph functional types across the oceanic provinces, as revealed in this study, challenges traditional interpretations of marine food web structures. Mixotrophs with acquired phototrophy (NCMs) warrant greater recognition in marine research.}, }
@article {pmid28755578, year = {2017}, author = {Gutiérrez, G and Chistyakova, LV and Villalobo, E and Kostygov, AY and Frolov, AO}, title = {Identification of Pelomyxa palustris Endosymbionts.}, journal = {Protist}, volume = {168}, number = {4}, pages = {408-424}, doi = {10.1016/j.protis.2017.06.001}, pmid = {28755578}, issn = {1618-0941}, mesh = {Archamoebae/*microbiology/physiology ; Deltaproteobacteria/classification/genetics/isolation &amp; purification/*physiology ; Methanosarcinales/classification/genetics/isolation &amp; purification/*physiology ; Phylogeny ; RNA, Archaeal/genetics ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rhodococcus/classification/genetics/isolation &amp; purification/*physiology ; Sequence Analysis, RNA ; *Symbiosis ; }, abstract = {Pelomyxa palustris is a giant anaerobic/microaerobic amoeba, characterized by a number of exceptional cytological and physiological features, among them the presumed absence of energy producing organelles and the presence of endosymbiotic bacteria. These endosymbionts have been previously distinguished as: a large rectangular-shaped Gram-variable rod with a central cleft; a slender Gram-negative rod; and a slender Gram-positive rod. Using DNA extracted from P. palustris cysts, we have obtained three SSU rRNA gene sequences. We have determined that these sequences are affiliated to three different prokaryotic genera: Methanosaeta (a methanogenic archaea), Syntrophorhabdus (a syntrophic Gram-negative bacteria) and Rhodococcus (an aerobic chemoorganotrophic Gram-positive bacteria). To our knowledge, it is the first time that Syntrophorhabdus has been described as an endosymbiont in association with a methanogen. Strikingly, no traces of Methanobacterium formicicum could be detected, despite this methanogen had allegedly been isolated from trophozoites of P. palustris. It seems that the host and the endosymbionts have established a multipartite syntrophic consortium resembling to some extent those found in sewage treatment plants.}, }
@article {pmid28753988, year = {2017}, author = {Cordaux, R and Gilbert, C}, title = {Evolutionary Significance of Wolbachia-to-Animal Horizontal Gene Transfer: Female Sex Determination and the f Element in the Isopod Armadillidium vulgare.}, journal = {Genes}, volume = {8}, number = {7}, pages = {}, pmid = {28753988}, issn = {2073-4425}, abstract = {An increasing number of horizontal gene transfer (HGT) events from bacteria to animals have been reported in the past years, many of which involve Wolbachia bacterial endosymbionts and their invertebrate hosts. Most transferred Wolbachia genes are neutrally-evolving fossils embedded in host genomes. A remarkable case of Wolbachia HGT for which a clear evolutionary significance has been demonstrated is the "f element", a nuclear Wolbachia insert involved in female sex determination in the terrestrial isopod Armadillidium vulgare. The f element represents an instance of bacteria-to-animal HGT that has occurred so recently that it was possible to infer the donor (feminizing Wolbachia closely related to the wVulC Wolbachia strain of A. vulgare) and the mechanism of integration (a nearly complete genome inserted by micro-homology-mediated recombination). In this review, we summarize our current knowledge of the f element and discuss arising perspectives regarding female sex determination, unstable inheritance, population dynamics and the molecular evolution of the f element. Overall, the f element unifies three major areas in evolutionary biology: symbiosis, HGT and sex determination. Its characterization highlights the tremendous impact sex ratio distorters can have on the evolution of sex determination mechanisms and sex chromosomes in animals and plants.}, }
@article {pmid28743814, year = {2017}, author = {Matsuoka, JI and Ishizuna, F and Kurumisawa, K and Morohashi, K and Ogawa, T and Hidaka, M and Saito, K and Ezawa, T and Aono, T}, title = {Stringent Expression Control of Pathogenic R-body Production in Legume Symbiont Azorhizobium caulinodans.}, journal = {mBio}, volume = {8}, number = {4}, pages = {}, pmid = {28743814}, issn = {2150-7511}, mesh = {Azorhizobium caulinodans/*genetics/*pathogenicity/ultrastructure ; Bacterial Proteins/*genetics/metabolism ; Cold Temperature ; Fabaceae/microbiology ; Gene Deletion ; *Gene Expression Regulation, Bacterial ; Inclusion Bodies/*metabolism/ultrastructure ; Ketoglutaric Acids/pharmacology ; Operon ; Paramecium/microbiology ; Promoter Regions, Genetic ; *Symbiosis ; }, abstract = {R bodies are insoluble large polymers consisting of small proteins encoded by reb genes and are coiled into cylindrical structures in bacterial cells. They were first discovered in Caedibacter species, which are obligate endosymbionts of paramecia. Caedibacter confers a killer trait on the host paramecia. R-body-producing symbionts are released from their host paramecia and kill symbiont-free paramecia after ingestion. The roles of R bodies have not been explained in bacteria other than CaedibacterAzorhizobium caulinodans ORS571, a microsymbiont of the legume Sesbania rostrata, carries a reb operon containing four reb genes that are regulated by the repressor PraR. Herein, deletion of the praR gene resulted in R-body formation and death of host plant cells. The rebR gene in the reb operon encodes an activator. Three PraR binding sites and a RebR binding site are present in the promoter region of the reb operon. Expression analyses using strains with mutations within the PraR binding site and/or the RebR binding site revealed that PraR and RebR directly control the expression of the reb operon and that PraR dominantly represses reb expression. Furthermore, we found that the reb operon is highly expressed at low temperatures and that 2-oxoglutarate induces the expression of the reb operon by inhibiting PraR binding to the reb promoter. We conclude that R bodies are toxic not only in paramecium symbiosis but also in relationships between other bacteria and eukaryotic cells and that R-body formation is controlled by environmental factors.IMPORTANCECaedibacter species, which are obligate endosymbiotic bacteria of paramecia, produce R bodies, and R-body-producing endosymbionts that are released from their hosts are pathogenic to symbiont-free paramecia. Besides Caedibacter species, R bodies have also been observed in a few free-living bacteria, but the significance of R-body production in these bacteria is still unknown. Recent advances in genome sequencing technologies revealed that many Gram-negative bacteria possess reb genes encoding R-body components, and interestingly, many of them are animal and plant pathogens. Azorhizobium caulinodans, a microsymbiont of the tropical legume Sesbania rostrata, also possesses reb genes. In this study, we demonstrate that A. caulinodans has ability to kill the host plant cells by producing R bodies, suggesting that pathogenicity conferred by an R body might be universal in bacteria possessing reb genes. Furthermore, we provide the first insight into the molecular mechanism underlying the expression of R-body production in response to environmental factors, such as temperature and 2-oxoglutarate.}, }
@article {pmid28738827, year = {2017}, author = {Lutfullahoğlu-Bal, G and Keskin, A and Seferoğlu, AB and Dunn, CD}, title = {Bacterial tail anchors can target to the mitochondrial outer membrane.}, journal = {Biology direct}, volume = {12}, number = {1}, pages = {16}, pmid = {28738827}, issn = {1745-6150}, support = {637649/ERC_/European Research Council/International ; }, mesh = {Escherichia coli Proteins/chemistry/*metabolism ; Eukaryotic Cells/metabolism/ultrastructure ; Mitochondria/metabolism ; Mitochondrial Membranes/*metabolism ; Organelle Biogenesis ; Protein Sorting Signals/physiology ; Protein Transport ; Saccharomyces cerevisiae/*metabolism/ultrastructure ; }, abstract = {BACKGROUND: During the generation and evolution of the eukaryotic cell, a proteobacterial endosymbiont was re-fashioned into the mitochondrion, an organelle that appears to have been present in the ancestor of all present-day eukaryotes. Mitochondria harbor proteomes derived from coding information located both inside and outside the organelle, and the rate-limiting step toward the formation of eukaryotic cells may have been development of an import apparatus allowing protein entry to mitochondria. Currently, a widely conserved translocon allows proteins to pass from the cytosol into mitochondria, but how proteins encoded outside of mitochondria were first directed to these organelles at the dawn of eukaryogenesis is not clear. Because several proteins targeted by a carboxyl-terminal tail anchor (TA) appear to have the ability to insert spontaneously into the mitochondrial outer membrane (OM), it is possible that self-inserting, tail-anchored polypeptides obtained from bacteria might have formed the first gate allowing proteins to access mitochondria from the cytosol.<br><br>RESULTS: Here, we tested whether bacterial TAs are capable of targeting to mitochondria. In a survey of proteins encoded by the proteobacterium Escherichia coli, predicted TA sequences were directed to specific subcellular locations within the yeast Saccharomyces cerevisiae. Importantly, TAs obtained from DUF883 family members ElaB and YqjD were abundantly localized to and inserted at the mitochondrial OM.<br><br>CONCLUSIONS: Our results support the notion that eukaryotic cells are able to utilize membrane-targeting signals present in bacterial proteins obtained by lateral gene transfer, and our findings make plausible a model in which mitochondrial protein translocation was first driven by tail-anchored proteins.<br><br>REVIEWERS: This article was reviewed by Michael Ryan and Thomas Simmen.}, }
@article {pmid28732048, year = {2017}, author = {Silva, JBL and Magalhães Alves, D and Bottino-Rojas, V and Pereira, TN and Sorgine, MHF and Caragata, EP and Moreira, LA}, title = {Wolbachia and dengue virus infection in the mosquito Aedes fluviatilis (Diptera: Culicidae).}, journal = {PloS one}, volume = {12}, number = {7}, pages = {e0181678}, pmid = {28732048}, issn = {1932-6203}, mesh = {Aedes/*microbiology/*virology ; Animals ; Brazil ; Culicidae/*microbiology/*virology ; Dengue/virology ; Dengue Virus/*pathogenicity ; Gram-Negative Bacterial Infections/microbiology ; Insect Vectors/microbiology/virology ; Pest Control, Biological/methods ; Saliva/microbiology/virology ; Symbiosis/physiology ; Viral Load/physiology ; Virus Replication/physiology ; Wolbachia/*pathogenicity ; }, abstract = {Dengue represents a serious threat to human health, with billions of people living at risk of the disease. Wolbachia pipientis is a bacterial endosymbiont common to many insect species. Wolbachia transinfections in mosquito disease vectors have great value for disease control given the bacterium's ability to spread into wild mosquito populations, and to interfere with infections of pathogens, such as dengue virus. Aedes fluviatilis is a mosquito with a widespread distribution in Latin America, but its status as a dengue vector has not been clarified. Ae. fluviatilis is also naturally infected by the wFlu Wolbachia strain, which has been demonstrated to enhance infection with the avian malarial parasite Plasmodium gallinaceum. We performed experimental infections of Ae. fluviatilis with DENV-2 and DENV-3 isolates from Brazil via injection or oral feeding to provide insight into its competence for the virus. We also examined the effect of the native Wolbachia infection on the virus using a mosquito line where the wFlu infection had been cleared by antibiotic treatment. Through RT-qPCR, we observed that Ae. fluviatilis could become infected with both viruses via either method of infection, although at a lower rate than Aedes aegypti, the primary dengue vector. We then detected DENV-2 and DENV-3 in the saliva of injected mosquitoes, and observed that injection of DENV-3-infected saliva produced subsequent infections in naïve Ae. aegypti. However, across our data we observed no difference in prevalence of infection and viral load between Wolbachia-infected and -uninfected mosquitoes, suggesting that there is no effect of wFlu on dengue virus. Our results highlight that Ae. fluviatilis could potentially serve as a dengue vector under the right circumstances, although further testing is required to determine if this occurs in the field.}, }
@article {pmid28729739, year = {2017}, author = {Sun, ZJ and Li, ZX}, title = {Host plants and obligate endosymbionts are not the sources for biosynthesis of the aphid alarm pheromone.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {6041}, pmid = {28729739}, issn = {2045-2322}, mesh = {Animals ; Aphids/*metabolism ; Buchnera ; Gas Chromatography-Mass Spectrometry ; *Host-Parasite Interactions ; Pheromones/analysis/*biosynthesis ; Plant Diseases/parasitology ; Plants/*microbiology/*parasitology ; *Symbiosis ; Volatile Organic Compounds/analysis ; }, abstract = {(E)-β-farnesene (EβF) is the major component of the alarm pheromone of many aphid species, but where EβF is synthesized in aphids is only partly understood. There are at least three most possible sources for the alarm pheromone: host plants, aphid obligate endosymbiont and aphids themselves. Here we eliminated the possibility of host plants and the obligate endosymbiont Buchnera aphidicola as the sources for EβF released by aphids. We excluded the possible effects of host plants on EβF biosynthesis by rearing aphids on non-plant diets. Both the diet-reared aphids, including the cotton aphid Aphis gossypii and the green peach aphid Myzus persicae, could still release EβF based on solid-phase micro-extraction combined with gas chromatography-mass spectrometer analysis. Meanwhile, we treated host aphids with antibiotics to fully eliminate Buchnera bacteria. Though the treatment seriously affected the development and fecundity of host aphids, the treated aphids could still release EβF, and there was no significant difference in the EβF concentration as per the aphid weight under different rearing conditions. Taken together, our experimental results suggest that host plants and obligate endosymbionts are not the sources for EβF released by aphids, indicating that it is most probably the aphid itself synthesizes the alarm pheromone.}, }
@article {pmid28724736, year = {2017}, author = {Le Clec'h, W and Dittmer, J and Raimond, M and Bouchon, D and Sicard, M}, title = {Phenotypic shift in Wolbachia virulence towards its native host across serial horizontal passages.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1859}, pages = {}, pmid = {28724736}, issn = {1471-2954}, mesh = {Animals ; Disease Transmission, Infectious ; Isopoda/*microbiology ; Phenotype ; *Symbiosis ; Virulence ; Wolbachia/genetics/*pathogenicity ; }, abstract = {Vertical transmission mode is predicted to decrease the virulence of symbionts. However, Wolbachia, a widespread vertically transmitted endosymbiont, exhibits both negative and beneficial effects on arthropod fitness. This 'Jekyll and Hyde' behaviour, as well as its ability to live transiently outside host cells and to establish new infections via horizontal transmission, may reflect the capacity of Wolbachia to exhibit various phenotypes depending on the prevailing environmental constraints. To study the ability of Wolbachia to readily cope with new constraints, we forced this endosymbiont to spread only via horizontal transmission. To achieve this, we performed serial horizontal transfers of haemolymph from Wolbachia-infected to naive individuals of the isopod Armadillidium vulgare. Across passages, we observed phenotypic changes in the symbiotic relationship: (i) The Wolbachia titre increased in both haemolymph and nerve cord but remained stable in ovaries; (ii) Wolbachia infection was benign at the beginning of the experiment, but highly virulent, killing most hosts after only a few passages. Such a phenotypic shift after recurrent horizontal passages demonstrates that Wolbachia can rapidly change its virulence when facing new environmental constraints. We thoroughly discuss the potential mechanism(s) underlying this phenotypic change, which are likely to be crucial for the ongoing radiation of Wolbachia in arthropods.}, }
@article {pmid28721658, year = {2017}, author = {Vieira, AS and Ramalho, MO and Martins, C and Martins, VG and Bueno, OC}, title = {Microbial Communities in Different Tissues of Atta sexdens rubropilosa Leaf-cutting Ants.}, journal = {Current microbiology}, volume = {74}, number = {10}, pages = {1216-1225}, pmid = {28721658}, issn = {1432-0991}, mesh = {Animals ; Ants/*microbiology ; Biodiversity ; Metagenome ; Metagenomics ; *Microbiota ; Organ Specificity ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Bacterial endosymbionts are common in all insects, and symbiosis has played an integral role in ant evolution. Atta sexdens rubropilosa leaf-cutting ants cultivate their symbiotic fungus using fresh leaves. They need to defend themselves and their brood against diseases, but they also need to defend their obligate fungus gardens, their primary food source, from infection, parasitism, and usurpation by competitors. This study aimed to characterize the microbial communities in whole workers and different tissues of A. sexdens rubropilosa queens using Ion Torrent NGS. Our results showed that the microbial community in the midgut differs in abundance and diversity from the communities in the postpharyngeal gland of the queen and in whole workers. The main microbial orders in whole workers were Lactobacillales, Clostridiales, Enterobacteriales, Actinomycetales, Burkholderiales, and Bacillales. In the tissues of the queens, the main orders were Burkholderiales, Clostridiales, Syntrophobacterales, Lactobacillales, Bacillales, and Actinomycetales (midgut) and Entomoplasmatales, unclassified γ-proteobacteria, and Actinomycetales (postpharyngeal glands). The high abundance of Entomoplasmatales in the postpharyngeal glands (77%) of the queens was an unprecedented finding. We discuss the role of microbial communities in different tissues and castes. Bacteria are likely to play a role in nutrition and immune defense as well as helping antimicrobial defense in this ant species.}, }
@article {pmid28721523, year = {2017}, author = {Messika, I and Garrido, M and Kedem, H and China, V and Gavish, Y and Dong, Q and Fuqua, C and Clay, K and Hawlena, H}, title = {From endosymbionts to host communities: factors determining the reproductive success of arthropod vectors.}, journal = {Oecologia}, volume = {184}, number = {4}, pages = {859-871}, pmid = {28721523}, issn = {1432-1939}, support = {2012063//United States - Israel Binational Science Foundation/International ; FP7-293713//Marie Curie Career Integration Grant/International ; 1391/15//Israel Science Foundation/International ; }, mesh = {Animals ; *Arthropod Vectors ; Female ; *Flea Infestations ; *Reproduction ; Rodentia ; Selection, Genetic ; Siphonaptera ; Symbiosis ; }, abstract = {Elucidating the factors determining reproductive success has challenged scientists since Darwin, but the exact pathways that shape the evolution of life history traits by connecting extrinsic (e.g., landscape structure) and intrinsic (e.g., female's age and endosymbionts) factors and reproductive success have rarely been studied. Here we collected female fleas from wild rodents in plots differing in their densities and proportions of the most dominant rodent species. We then combined path analysis and model selection approaches to explore the network of effects, ranging from micro to macroscales, determining the reproductive success of these fleas. Our results suggest that female reproductive success is directly and positively associated with their infection by Mycoplasma bacteria and their own body mass, and with the rodent species size and total density. In addition, we found evidence for indirect effects of rodent sex and rodent community diversity on female reproductive success. These results highlight the importance of exploring interrelated factors across organization scales while studying the reproductive success of wild organisms, and they have implications for the control of vector-borne diseases.}, }
@article {pmid28715422, year = {2017}, author = {Tirera, S and Ginouves, M and Donato, D and Caballero, IS and Bouchier, C and Lavergne, A and Bourreau, E and Mosnier, E and Vantilcke, V and Couppié, P and Prevot, G and Lacoste, V}, title = {Unraveling the genetic diversity and phylogeny of Leishmania RNA virus 1 strains of infected Leishmania isolates circulating in French Guiana.}, journal = {PLoS neglected tropical diseases}, volume = {11}, number = {7}, pages = {e0005764}, pmid = {28715422}, issn = {1935-2735}, mesh = {Adult ; Aged ; Cluster Analysis ; Female ; French Guiana ; *Genetic Variation ; Genome, Viral ; Humans ; Leishmania/isolation &amp; purification/*virology ; Leishmaniasis/parasitology ; Leishmaniavirus/*classification/genetics/*isolation &amp; purification ; Male ; Middle Aged ; *Phylogeny ; RNA, Viral/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Young Adult ; }, abstract = {INTRODUCTION: Leishmania RNA virus type 1 (LRV1) is an endosymbiont of some Leishmania (Vianna) species in South America. Presence of LRV1 in parasites exacerbates disease severity in animal models and humans, related to a disproportioned innate immune response, and is correlated with drug treatment failures in humans. Although the virus was identified decades ago, its genomic diversity has been overlooked until now.<br><br>We subjected LRV1 strains from 19 L. (V.) guyanensis and one L. (V.) braziliensis isolates obtained from cutaneous leishmaniasis samples identified throughout French Guiana with next-generation sequencing and de novo sequence assembly. We generated and analyzed 24 unique LRV1 sequences over their full-length coding regions. Multiple alignment of these new sequences revealed variability (0.5%-23.5%) across the entire sequence except for highly conserved motifs within the 5' untranslated region. Phylogenetic analyses showed that viral genomes of L. (V.) guyanensis grouped into five distinct clusters. They further showed a species-dependent clustering between viral genomes of L. (V.) guyanensis and L. (V.) braziliensis, confirming a long-term co-evolutionary history. Noteworthy, we identified cases of multiple LRV1 infections in three of the 20 Leishmania isolates.<br><br>CONCLUSIONS/SIGNIFICANCE: Here, we present the first-ever estimate of LRV1 genomic diversity that exists in Leishmania (V.) guyanensis parasites. Genetic characterization and phylogenetic analyses of these viruses has shed light on their evolutionary relationships. To our knowledge, this study is also the first to report cases of multiple LRV1 infections in some parasites. Finally, this work has made it possible to develop molecular tools for adequate identification and genotyping of LRV1 strains for diagnostic purposes. Given the suspected worsening role of LRV1 infection in the pathogenesis of human leishmaniasis, these data have a major impact from a clinical viewpoint and for the management of Leishmania-infected patients.}, }
@article {pmid28710265, year = {2017}, author = {Azagi, T and Klement, E and Perlman, G and Lustig, Y and Mumcuoglu, KY and Apanaskevich, DA and Gottlieb, Y}, title = {Francisella-Like Endosymbionts and Rickettsia Species in Local and Imported Hyalomma Ticks.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {18}, pages = {}, pmid = {28710265}, issn = {1098-5336}, mesh = {Animal Migration ; Animals ; Arachnid Vectors/*microbiology/physiology ; Birds/*parasitology/physiology ; Francisella/*physiology ; Gram-Negative Bacterial Infections/microbiology/transmission ; Humans ; Ixodidae/*microbiology/physiology ; Phylogeny ; Rickettsia/*physiology ; Rickettsia Infections/microbiology/transmission ; *Symbiosis ; Zoonoses/microbiology/*transmission ; }, abstract = {Hyalomma ticks (Acari: Ixodidae) are hosts for Francisella-like endosymbionts (FLE) and may serve as vectors of zoonotic disease agents. This study aimed to provide an initial characterization of the interaction between Hyalomma and FLE and to determine the prevalence of pathogenic Rickettsia in these ticks. Hyalomma marginatum, Hyalomma rufipes, Hyalommadromedarii, Hyalommaaegyptium, and Hyalommaexcavatum ticks, identified morphologically and molecularly, were collected from different hosts and locations representing the distribution of the genus Hyalomma in Israel, as well as from migratory birds. A high prevalence of FLE was found in all Hyalomma species (90.6%), as well as efficient maternal transmission of FLE (91.8%), and the localization of FLE in Malpighian tubules, ovaries, and salivary glands in H. marginatum Furthermore, we demonstrated strong cophylogeny between FLE and their host species. Contrary to FLE, the prevalence of Rickettsia ranged from 2.4% to 81.3% and was significantly different between Hyalomma species, with a higher prevalence in ticks collected from migratory birds. Using ompA gene sequences, most of the Rickettsia spp. were similar to Rickettsiaaeschlimannii, while a few were similar to Rickettsiaafricae of the spotted fever group (SFG). Given their zoonotic importance, 249 ticks were tested for Crimean Congo hemorrhagic fever virus infection, and all were negative. The results imply that Hyalomma and FLE have obligatory symbiotic interactions, indicating a potential SFG Rickettsia zoonosis risk. A further understanding of the possible influence of FLE on Hyalomma development, as well as on its infection with Rickettsia pathogens, may lead to novel ways to control tick-borne zoonoses.IMPORTANCE This study shows that Francisella-like endosymbionts were ubiquitous in Hyalomma, were maternally transmitted, and cospeciated with their hosts. These findings imply that the interaction between FLE and Hyalomma is of an obligatory nature. It provides an example of an integrative taxonomy approach to simply differentiate among species infesting the same host and to identify nymphal and larval stages to be used in further studies. In addition, it shows the potential of imported Hyalomma ticks to serve as a vector for spotted fever group rickettsiae. The information gathered in this study can be further implemented in the development of symbiont-based disease control strategies for the benefit of human health.}, }
@article {pmid28702705, year = {2018}, author = {Duplouy, A and Brattström, O}, title = {Wolbachia in the Genus Bicyclus: a Forgotten Player.}, journal = {Microbial ecology}, volume = {75}, number = {1}, pages = {255-263}, pmid = {28702705}, issn = {1432-184X}, mesh = {Animals ; Biological Evolution ; Butterflies/growth &amp; development/*microbiology/physiology ; Phylogeny ; Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Bicyclus butterflies are key species for studies of wing pattern development, phenotypic plasticity, speciation and the genetics of Lepidoptera. One of the key endosymbionts in butterflies, the alpha-Proteobacterium Wolbachia pipientis, is affecting many of these biological processes; however, Bicyclus butterflies have not been investigated systematically as hosts to Wolbachia. In this study, we screen for Wolbachia infection in several Bicyclus species from natural populations across Africa as well as two laboratory populations. Out of the 24 species tested, 19 were found to be infected, and no double infection was found, but both A- and B-supergroup strains colonise this butterfly group. We also show that many of the Wolbachia strains identified in Bicyclus butterflies belong to the ST19 clonal complex. We discuss the importance of our results in regard to routinely screening for Wolbachia when using Bicyclus butterflies as the study organism of research in eco-evolutionary biology.}, }
@article {pmid28702014, year = {2017}, author = {Ioannidis, A and Papaioannou, P and Magiorkinis, E and Magana, M and Ioannidou, V and Tzanetou, K and Burriel, AR and Tsironi, M and Chatzipanagiotou, S}, title = {Detecting the Diversity of Mycoplasma and Ureaplasma Endosymbionts Hosted by Trichomonas vaginalis Isolates.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {1188}, pmid = {28702014}, issn = {1664-302X}, abstract = {Objectives: The symbiosis of Trichomonas vaginalis and Mycoplasma hominis is the first described association between two obligate human parasites. Trichomonas is the niche and the vector for the transmission of M. hominis infection. This clinically significant symbiosis may affect T. vaginalis virulence and susceptibility to treatment. The aims of this study were to investigate the intracellularly present Mycoplasma and Ureaplasma species in T. vaginalis strains isolated from the vaginal discharge of infected women as well as to trace the diversity pattern among the species detected in the isolated strains. Methods: Hundred pure T. vaginalis cultures were isolated from ~7,500 patient specimens presented with clinical purulent vaginitis. PCR and sequencing for Mycoplasma/Ureaplasma spp. were performed in DNA extracted from the pure cultures. In addition, vaginal discharge samples were cultured for the presence of M. hominis and U. urealyticum. Phylogenetic analysis assisted the identification of interspecies relationships between the Mycoplasma and Ureaplasma isolates. Results: Fifty four percentage of T. vaginalis isolates were harboring Mycoplasma spp. Phylogenetic analysis revealed three distinct clusters, two with already characterized M. hominis and Ureaplasma spp. (37% of total Mycoplasma spp.), whereas one group formed a distinct cluster matched with the newly identified species Candidatus Mycoplasma girerdii (59.3%) and one or more unknown Mycoplasma spp. (3.7%). Conclusions:T. vaginalis strains associated with vaginal infection might host intracellular mycoplasmas or ureaplasmas. Intracellular Mollicutes that remain undetected in the extracellular environment when conventional diagnostic methods are implemented may comprise either novel species, such as Candidatus M. giredii, or unknown species with yet unexplored clinical significance.}, }
@article {pmid28683118, year = {2017}, author = {Stuhr, M and Reymond, CE and Rieder, V and Hallock, P and Rahnenführer, J and Westphal, H and Kucera, M}, title = {Reef calcifiers are adapted to episodic heat stress but vulnerable to sustained warming.}, journal = {PloS one}, volume = {12}, number = {7}, pages = {e0179753}, pmid = {28683118}, issn = {1932-6203}, mesh = {*Adaptation, Physiological ; Animals ; Anthozoa/*physiology ; Antioxidants/metabolism ; Chlorophyll/biosynthesis ; Chlorophyll A ; Chlorophyta/*physiology ; Climate Change ; Coral Reefs ; Ecosystem ; Hot Temperature ; *Models, Statistical ; *Stress, Physiological ; Symbiosis/physiology ; }, abstract = {Shallow marine ecosystems naturally experience fluctuating physicochemical conditions across spatial and temporal scales. Widespread coral-bleaching events, induced by prolonged heat stress, highlight the importance of how the duration and frequency of thermal stress influence the adaptive physiology of photosymbiotic calcifiers. Large benthic foraminifera harboring algal endosymbionts are major tropical carbonate producers and bioindicators of ecosystem health. Like corals, they are sensitive to thermal stress and bleach at temperatures temporarily occurring in their natural habitat and projected to happen more frequently. However, their thermal tolerance has been studied so far only by chronic exposure, so how they respond under more realistic episodic heat-event scenarios remains unknown. Here, we determined the physiological responses of Amphistegina gibbosa, an abundant western Atlantic foraminifera, to four different treatments--control, single, episodic, and chronic exposure to the same thermal stress (32°C)--in controlled laboratory cultures. Exposure to chronic thermal stress reduced motility and growth, while antioxidant capacity was elevated, and photosymbiont variables (coloration, oxygen-production rates, chlorophyll a concentration) indicated extensive bleaching. In contrast, single- and episodic-stress treatments were associated with higher motility and growth, while photosymbiont variables remained stable. The effects of single and episodic heat events were similar, except for the presumable occurrence of reproduction, which seemed to be suppressed by both episodic and chronic stress. The otherwise different responses between treatments with thermal fluctuations and chronic stress indicate adaptation to thermal peaks, but not to chronic exposure expected to ensue when baseline temperatures are elevated by climate change. This firstly implies that marine habitats with a history of fluctuating thermal stress potentially support resilient physiological mechanisms among photosymbiotic organisms. Secondly, there seem to be temporal constraints related to heat events among coral reef environments and reinforces the importance of temporal fluctuations in stress exposure in global-change studies and projections.}, }
@article {pmid28680117, year = {2017}, author = {Doudoumis, V and Blow, F and Saridaki, A and Augustinos, A and Dyer, NA and Goodhead, I and Solano, P and Rayaisse, JB and Takac, P and Mekonnen, S and Parker, AG and Abd-Alla, AMM and Darby, A and Bourtzis, K and Tsiamis, G}, title = {Challenging the Wigglesworthia, Sodalis, Wolbachia symbiosis dogma in tsetse flies: Spiroplasma is present in both laboratory and natural populations.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {4699}, pmid = {28680117}, issn = {2045-2322}, support = {BB/J017698/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/K501773/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Animals, Wild/microbiology/parasitology ; Enterobacteriaceae/classification/genetics/*isolation &amp; purification/physiology ; Female ; High-Throughput Nucleotide Sequencing ; Male ; Multilocus Sequence Typing ; Ovary/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, RNA ; Species Specificity ; Spiroplasma/classification/genetics/*isolation &amp; purification/physiology ; Symbiosis ; Testis/microbiology ; Tissue Distribution ; Tsetse Flies/classification/growth &amp; development/*microbiology/*parasitology ; Wigglesworthia/classification/genetics/*isolation &amp; purification/physiology ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Profiling of wild and laboratory tsetse populations using 16S rRNA gene amplicon sequencing allowed us to examine whether the "Wigglesworthia-Sodalis-Wolbachia dogma" operates across species and populations. The most abundant taxa, in wild and laboratory populations, were Wigglesworthia (the primary endosymbiont), Sodalis and Wolbachia as previously characterized. The species richness of the microbiota was greater in wild than laboratory populations. Spiroplasma was identified as a new symbiont exclusively in Glossina fuscipes fuscipes and G. tachinoides, members of the palpalis sub-group, and the infection prevalence in several laboratory and natural populations was surveyed. Multi locus sequencing typing (MLST) analysis identified two strains of tsetse-associated Spiroplasma, present in G. f. fuscipes and G. tachinoides. Spiroplasma density in G. f. fuscipes larva guts was significantly higher than in guts from teneral and 15-day old male and female adults. In gonads of teneral and 15-day old insects, Spiroplasma density was higher in testes than ovaries, and was significantly higher density in live versus prematurely deceased females indicating a potentially mutualistic association. Higher Spiroplasma density in testes than in ovaries was also detected by fluorescent in situ hybridization in G. f. fuscipes.}, }
@article {pmid28677262, year = {2017}, author = {Mikaelyan, A and Thompson, CL and Meuser, K and Zheng, H and Rani, P and Plarre, R and Brune, A}, title = {High-resolution phylogenetic analysis of Endomicrobia reveals multiple acquisitions of endosymbiotic lineages by termite gut flagellates.}, journal = {Environmental microbiology reports}, volume = {9}, number = {5}, pages = {477-483}, doi = {10.1111/1758-2229.12565}, pmid = {28677262}, issn = {1758-2229}, mesh = {Animals ; Bacteria/classification/genetics ; DNA, Intergenic ; *Gastrointestinal Microbiome ; Insecta/microbiology ; *Metagenome ; *Metagenomics/methods ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; *Symbiosis ; }, abstract = {Bacteria of the class Endomicrobia form a deep-branching clade in the Elusimicrobia phylum. They are found almost exclusively in the intestinal tract of animals and are particularly abundant in many termites, where they reside as intracellular symbionts in the cellulolytic gut flagellates. Although small populations of putatively free-living lineages have been detected in faunated and flagellate-free hosts, the evolutionary origin of the endosymbionts is obscured by the limited amount of phylogenetic information provided by the 16S rRNA gene fragment amplified with Endomicrobia-specific primers. Here, we present a robust phylogenetic framework based on the near-full-length 16S-23S rRNA gene region of a diverse set of Endomicrobia from termites and cockroaches, which also allowed us to classify the shorter reads from previous studies. Our data revealed that endosymbionts arose independently at least four times from different free-living lineages, which were already present in ancestral cockroaches but became associated with their respective hosts long after the digestive symbiosis between termites and flagellates had been established. Pyrotag sequencing revealed that the proportion of putatively free-living lineages increased, when all flagellates and their symbionts were removed from the gut of lower termites by starvation, starch feeding or hyperbaric oxygen, but results varied between different methods.}, }
@article {pmid28673455, year = {2017}, author = {Cicuttin, GL and De Salvo, MN and La Rosa, I and Dohmen, FEG}, title = {Neorickettsia risticii, Rickettsia sp. and Bartonella sp. in Tadarida brasiliensis bats from Buenos Aires, Argentina.}, journal = {Comparative immunology, microbiology and infectious diseases}, volume = {52}, number = {}, pages = {1-5}, doi = {10.1016/j.cimid.2017.04.004}, pmid = {28673455}, issn = {1878-1667}, mesh = {Anaplasmataceae Infections/epidemiology/veterinary ; Animals ; Argentina/epidemiology ; Bacterial Proteins/genetics ; Bartonella/genetics/*isolation &amp; purification ; Bartonella Infections/epidemiology/veterinary ; Chiroptera/*microbiology ; Citrate (si)-Synthase/genetics ; *Disease Reservoirs ; Neorickettsia risticii/genetics/*isolation &amp; purification ; Phylogeny ; Polymerase Chain Reaction ; Rickettsia/genetics/*isolation &amp; purification ; Rickettsia Infections/epidemiology/veterinary ; Sequence Analysis, DNA ; }, abstract = {Bats are potential reservoirs of many vector-borne bacterial pathogens. The aim of the present study was to detect species of Anaplasma, Ehrlichia, Neorickettsia, Rickettsia, Borrelia and Bartonella in Brazilian free-tailed bats (Tadarida brasiliensis, Molossidae) from Buenos Aires city, Argentina. Between 2012 and 2013, 61 T. brasiliensis from urban areas of Buenos Aires city were studied. The samples were molecularly screened by PCR and sequencing. Five bats (8.2%) were positive to Neorickettsia risticii, one (1.6%) was positive to Rickettsia sp. and three bats (4.9%) to Bartonella sp. For molecular characterization, the positive samples were subjected to amplification and sequencing of a fragment of p51 gene for N. risticii, a fragment of citrate synthase gene (gltA) for Rickettsia genus and a fragment of gltA for Bartonella genus. Phylogenetic tree was constructed using the maximum-likelihood method. Phylogenetic analysis of N. risticii detect in our study revealed that it relates to findings in the USA West Coast; Rickettsia sp. detected is phylogenetically within R. bellii group, which also includes many other Rickettsia endosymbionts of insects; and Bartonella sp. found is related to various Bartonella spp. described in Vespertilionidae bats, which are phylogenetically related to Molossidae. Our results are in accordance to previous findings, which demonstrate that insectivorous bats could be infected with vector-borne bacteria representing a potential risk to public health. Future research is necessary to clarify the circulation of these pathogens in bats from Buenos Aires.}, }
@article {pmid28659491, year = {2017}, author = {Agostoni, M and Hangasky, JA and Marletta, MA}, title = {Physiological and Molecular Understanding of Bacterial Polysaccharide Monooxygenases.}, journal = {Microbiology and molecular biology reviews : MMBR}, volume = {81}, number = {3}, pages = {}, pmid = {28659491}, issn = {1098-5557}, mesh = {Animals ; Bacteria/*enzymology/genetics/metabolism/pathogenicity ; Bacterial Infections/microbiology ; Cellulose/metabolism ; Chitin/metabolism ; Glycoside Hydrolases/chemistry/genetics/metabolism ; Host-Pathogen Interactions ; Humans ; Listeria monocytogenes/enzymology/genetics ; Mixed Function Oxygenases/chemistry/*genetics/*metabolism ; Polysaccharides, Bacterial/*chemistry/*metabolism ; Pseudomonas/enzymology/genetics ; Substrate Specificity ; Virulence Factors ; }, abstract = {Bacteria have long been known to secrete enzymes that degrade cellulose and chitin. The degradation of these two polymers predominantly involves two enzyme families that work synergistically with one another: glycoside hydrolases (GHs) and polysaccharide monooxygenases (PMOs). Although bacterial PMOs are a relatively recent addition to the known biopolymer degradation machinery, there is an extensive amount of literature implicating PMO in numerous physiological roles. This review focuses on these diverse and physiological aspects of bacterial PMOs, including facilitating endosymbiosis, conferring a nutritional advantage, and enhancing virulence in pathogenic organisms. We also discuss the correlation between the presence of PMOs and bacterial lifestyle and speculate on the advantages conferred by PMOs under these conditions. In addition, the molecular aspects of bacterial PMOs, as well as the mechanisms regulating PMO expression and the function of additional domains associated with PMOs, are described. We anticipate that increasing research efforts in this field will continue to expand our understanding of the molecular and physiological roles of bacterial PMOs.}, }
@article {pmid28659447, year = {2017}, author = {Bing, X and Attardo, GM and Vigneron, A and Aksoy, E and Scolari, F and Malacrida, A and Weiss, BL and Aksoy, S}, title = {Unravelling the relationship between the tsetse fly and its obligate symbiont Wigglesworthia: transcriptomic and metabolomic landscapes reveal highly integrated physiological networks.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1857}, pages = {}, pmid = {28659447}, issn = {1471-2954}, support = {R01 AI081774/AI/NIAID NIH HHS/United States ; R21 AI109263/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acids/metabolism ; Animals ; Carbohydrate Metabolism ; Chaperonin 60/metabolism ; Female ; *Metabolome ; Sequence Analysis, RNA ; *Symbiosis ; *Transcriptome ; Tsetse Flies/metabolism/*microbiology ; Vitamin B Complex/biosynthesis ; Wigglesworthia/*metabolism ; }, abstract = {Insects with restricted diets rely on obligate microbes to fulfil nutritional requirements essential for biological function. Tsetse flies, vectors of African trypanosome parasites, feed exclusively on vertebrate blood and harbour the obligate endosymbiont Wigglesworthia glossinidia. Without Wigglesworthia, tsetse are unable to reproduce. These symbionts are sheltered within specialized cells (bacteriocytes) that form the midgut-associated bacteriome organ. To decipher the core functions of this symbiosis essential for tsetse's survival, we performed dual-RNA-seq analysis of the bacteriome, coupled with metabolomic analysis of bacteriome and haemolymph collected from normal and symbiont-cured (sterile) females. Bacteriocytes produce immune regulatory peptidoglycan recognition protein (pgrp-lb) that protects Wigglesworthia, and a multivitamin transporter (smvt) that can aid in nutrient dissemination. Wigglesworthia overexpress a molecular chaperone (GroEL) to augment their translational/transport machinery and biosynthesize an abundance of B vitamins (specifically B1-, B2-, B3- and B6-associated metabolites) to supplement the host's nutritionally deficient diet. The absence of Wigglesworthia's contributions disrupts multiple metabolic pathways impacting carbohydrate and amino acid metabolism. These disruptions affect the dependent downstream processes of nucleotide biosynthesis and metabolism and biosynthesis of S-adenosyl methionine (SAM), an essential cofactor. This holistic fundamental knowledge of the symbiotic dialogue highlights new biological targets for the development of innovative vector control methods.}, }
@article {pmid28659179, year = {2017}, author = {Faddeeva-Vakhrusheva, A and Kraaijeveld, K and Derks, MFL and Anvar, SY and Agamennone, V and Suring, W and Kampfraath, AA and Ellers, J and Le Ngoc, G and van Gestel, CAM and Mariën, J and Smit, S and van Straalen, NM and Roelofs, D}, title = {Coping with living in the soil: the genome of the parthenogenetic springtail Folsomia candida.}, journal = {BMC genomics}, volume = {18}, number = {1}, pages = {493}, pmid = {28659179}, issn = {1471-2164}, mesh = {Animals ; Anti-Bacterial Agents/biosynthesis ; Arthropods/*genetics/metabolism/*physiology ; Gene Rearrangement ; Gene Transfer, Horizontal ; *Genomics ; Multigene Family/genetics ; Phylogeny ; *Soil ; }, abstract = {BACKGROUND: Folsomia candida is a model in soil biology, belonging to the family of Isotomidae, subclass Collembola. It reproduces parthenogenetically in the presence of Wolbachia, and exhibits remarkable physiological adaptations to stress. To better understand these features and adaptations to life in the soil, we studied its genome in the context of its parthenogenetic lifestyle.<br><br>RESULTS: We applied Pacific Bioscience sequencing and assembly to generate a reference genome for F. candida of 221.7 Mbp, comprising only 162 scaffolds. The complete genome of its endosymbiont Wolbachia, was also assembled and turned out to be the largest strain identified so far. Substantial gene family expansions and lineage-specific gene clusters were linked to stress response. A large number of genes (809) were acquired by horizontal gene transfer. A substantial fraction of these genes are involved in lignocellulose degradation. Also, the presence of genes involved in antibiotic biosynthesis was confirmed. Intra-genomic rearrangements of collinear gene clusters were observed, of which 11 were organized as palindromes. The Hox gene cluster of F. candida showed major rearrangements compared to arthropod consensus cluster, resulting in a disorganized cluster.<br><br>CONCLUSIONS: The expansion of stress response gene families suggests that stress defense was important to facilitate colonization of soils. The large number of HGT genes related to lignocellulose degradation could be beneficial to unlock carbohydrate sources in soil, especially those contained in decaying plant and fungal organic matter. Intra- as well as inter-scaffold duplications of gene clusters may be a consequence of its parthenogenetic lifestyle. This high quality genome will be instrumental for evolutionary biologists investigating deep phylogenetic lineages among arthropods and will provide the basis for a more mechanistic understanding in soil ecology and ecotoxicology.}, }
@article {pmid28655825, year = {2017}, author = {Fellows, JD and Cipriano, MJ and Agrawal, S and Striepen, B}, title = {A Plastid Protein That Evolved from Ubiquitin and Is Required for Apicoplast Protein Import in Toxoplasma gondii.}, journal = {mBio}, volume = {8}, number = {3}, pages = {}, pmid = {28655825}, issn = {2150-7511}, support = {R01 AI064671/AI/NIAID NIH HHS/United States ; }, mesh = {Apicoplasts/*metabolism ; Cell Survival ; Chloroplast Proteins/genetics/*metabolism ; Gene Knockout Techniques ; Phylogeny ; Protein Transport ; Sequence Homology, Amino Acid ; Toxoplasma/genetics/*metabolism ; Ubiquitins/genetics/*metabolism ; }, abstract = {Apicomplexan parasites cause a variety of important infectious diseases, including malaria, toxoplasma encephalitis, and severe diarrhea due to Cryptosporidium Most apicomplexans depend on an organelle called the apicoplast which is derived from a red algal endosymbiont. The apicoplast is essential for the parasite as the compartment of fatty acid, heme, and isoprenoid biosynthesis. The majority of the approximate 500 apicoplast proteins are nucleus encoded and have to be imported across the four membranes that surround the apicoplast. Import across the second outermost membrane of the apicoplast, the periplastid membrane, depends on an apicoplast-specific endoplasmic reticulum-associated protein degradation (ERAD) complex and on enzymes of the associated ubiquitination cascade. However, identification of an apicoplast ubiquitin associated with this machinery has long been elusive. Here we identify a plastid ubiquitin-like protein (PUBL), an apicoplast protein that is derived from a ubiquitin ancestor but that has significantly changed in its primary sequence. PUBL is distinct from known ubiquitin-like proteins, and phylogenomic analyses suggest a clade specific to apicomplexans. We demonstrate that PUBL and the AAA ATPase CDC48AP both act to translocate apicoplast proteins across the periplastid membrane during protein import. Conditional null mutants and genetic complementation show that both proteins are critical for this process and for parasite survival. PUBL residues homologous to those that are required for ubiquitin conjugation onto target proteins are essential for this function, while those required for polyubiquitination and preprotein processing are dispensable. Our experiments provide a mechanistic understanding of the molecular machinery that drives protein import across the membranes of the apicoplast.IMPORTANCE Apicomplexan parasites are responsible for important human diseases. There are no effective vaccines for use in humans, and drug treatment faces multiple challenges, including emerging resistance, lack of efficacy across the lifecycle, and adverse drug effects. The apicoplast is a promising target for novel treatments: this chloroplast-like organelle is derived from an algal symbiont, is absent from the host, and is essential for parasite growth and pathogenesis. We use Toxoplasma gondii as a model to study the apicoplast due to its strong genetic tools and established functional assays. We identify a plastid ubiquitin-like protein (PUBL) which is a novel ubiquitin-like protein and demonstrate its importance and that of the motor protein CDC48AP for apicoplast protein import. These findings broaden our understanding of the evolution and mechanistic workings of a unique parasite organelle and may lead to new opportunities for treatments against important human pathogens.}, }
@article {pmid28655293, year = {2017}, author = {Zhao, C and Nabity, PD}, title = {Plant manipulation through gall formation constrains amino acid transporter evolution in sap-feeding insects.}, journal = {BMC evolutionary biology}, volume = {17}, number = {1}, pages = {153}, pmid = {28655293}, issn = {1471-2148}, mesh = {Amino Acid Transport Systems/*genetics ; Animals ; Aphids/classification/*genetics/physiology ; *Evolution, Molecular ; Gene Expression Profiling ; *Herbivory ; Insect Proteins/*genetics ; Phylogeny ; Plant Physiological Phenomena ; Plant Tumors ; Symbiosis ; }, abstract = {BACKGROUND: The herbivore lifestyle leads to encounters with plant toxins and requires mechanisms to overcome suboptimal nutrient availability in plant tissues. Although the evolution of bacterial endosymbiosis alleviated many of these challenges, the ability to manipulate plant nutrient status has evolved in lineages with and without nutritional symbionts. Whether and how these alternative nutrient acquisition strategies interact or constrain insect evolution is unknown. We studied the transcriptomes of galling and free-living aphidomorphs to characterize how amino acid transporter evolution is influenced by the ability to manipulate plant resource availability.<br><br>RESULTS: Using a comparative approach we found phylloxerids retain nearly all amino acid transporters as other aphidomorphs, despite loss of nutritional endosymbiosis. Free living species show more transporters than galling species within the same genus, family, or infraorder, indicating plant hosts influence the maintenance and evolution of nutrient transport within herbivores. Transcript profiles also show lineage specificity and suggest some genes may facilitate life without endosymbionts or the galling lifestyle.<br><br>CONCLUSIONS: The transcript abundance profiles we document across fluid feeding herbivores support plant host constraint on insect amino acid transporter evolution. Given amino acid uptake, transport, and catabolism underlie the success of herbivory as a life history strategy, this suggests that plant host nutrient quality, whether constitutive or induced, alters the selective environment surrounding the evolution and maintenance of endosymbiosis.}, }
@article {pmid28654044, year = {2017}, author = {Zhu, DT and Wang, XR and Ban, FX and Zou, C and Liu, SS and Wang, XW}, title = {Methods for the Extraction of Endosymbionts from the Whitefly Bemisia tabaci.}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {124}, pages = {}, pmid = {28654044}, issn = {1940-087X}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics ; Hemiptera/genetics/*microbiology ; In Situ Hybridization, Fluorescence ; Metagenome/genetics ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Bacterial symbionts form an intimate relationship with their hosts and confer advantages to the hosts in most cases. Genomic information is critical to study the functions and evolution of bacterial symbionts in their host. As most symbionts cannot be cultured in vitro, methods to isolate an adequate quantity of bacteria for genome sequencing are very important. In the whitefly Bemisia tabaci, a number of endosymbionts have been identified and are predicted to be of importance in the development and reproduction of the pests through multiple approaches. However, the mechanism underpinning the associations remains largely unknown. The obstacle partially comes from the fact that the endosymbionts in whitefly, mostly restrained in bacteriocytes, are hard to separate from the host cells. Here we report a step-by-step protocol for the identification, extraction and purification of endosymbionts from the whitefly B. tabaci mainly by dissection and filtration. Endosymbiont samples prepared by this method, although still a mixture of different endosymbiont species, are suitable for subsequent genome sequencing and analysis of the possible roles of endosymbionts in B. tabaci. This method may also be used to isolate endosymbionts from other insects.}, }
@article {pmid28646115, year = {2017}, author = {Zheng, H and Dietrich, C and Brune, A}, title = {Genome Analysis of Endomicrobium proavitum Suggests Loss and Gain of Relevant Functions during the Evolution of Intracellular Symbionts.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {17}, pages = {}, pmid = {28646115}, issn = {1098-5336}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Eukaryota/physiology ; Evolution, Molecular ; *Genome, Bacterial ; Genomics ; Isoptera/microbiology ; Phylogeny ; *Symbiosis ; }, abstract = {Bacterial endosymbionts of eukaryotes show progressive genome erosion, but detailed investigations of the evolutionary processes involved in the transition to an intracellular lifestyle are generally hampered by the lack of extant free-living lineages. Here, we characterize the genome of the recently isolated, free-living Endomicrobium proavitum, the second member of the Elusimicrobia phylum brought into pure culture, and compare it to the closely related "Candidatus Endomicrobium trichonymphae" strain Rs-D17, a previously described but uncultured endosymbiont of termite gut flagellates. A reconstruction of the metabolic pathways of Endomicrobium proavitum matched the fermentation products formed in pure culture and underscored its restriction to glucose as the substrate. However, several pathways present in the free-living strain, e.g., for the uptake and activation of glucose and its subsequent fermentation, ammonium assimilation, and outer membrane biogenesis, were absent or disrupted in the endosymbiont, probably lost during the massive genome rearrangements that occurred during symbiogenesis. While the majority of the genes in strain Rs-D17 have orthologs in Endomicrobium proavitum, the endosymbiont also possesses a number of functions that are absent from the free-living strain and may represent adaptations to the intracellular lifestyle. Phylogenetic analysis revealed that the genes encoding glucose 6-phosphate and amino acid transporters, acetaldehyde/alcohol dehydrogenase, and the pathways of glucuronic acid catabolism and thiamine pyrophosphate biosynthesis were either acquired by horizontal gene transfer or may represent ancestral traits that were lost in the free-living strain. The polyphyletic origin of Endomicrobia in different flagellate hosts makes them excellent models for future studies of convergent and parallel evolution during symbiogenesis.IMPORTANCE The isolation of a free-living relative of intracellular symbionts provides the rare opportunity to identify the evolutionary processes that occur in the course of symbiogenesis. Our study documents that the genome of "Candidatus Endomicrobium trichonymphae," which represents a clade of endosymbionts that have coevolved with termite gut flagellates for more than 40 million years, is not simply a subset of the genes present in Endomicrobium proavitum, a member of the ancestral, free-living lineage. Rather, comparative genomics revealed that the endosymbionts possess several relevant functions that were either prerequisites for colonization of the intracellular habitat or might have served to compensate for genes losses that occurred during genome erosion. Some gene sets found only in the endosymbiont were apparently acquired by horizontal transfer from other gut bacteria, which suggests that the intracellular bacteria of flagellates are not entirely cut off from gene flow.}, }
@article {pmid28640457, year = {2017}, author = {Ferla, MP and Brewster, JL and Hall, KR and Evans, GB and Patrick, WM}, title = {Primordial-like enzymes from bacteria with reduced genomes.}, journal = {Molecular microbiology}, volume = {105}, number = {4}, pages = {508-524}, doi = {10.1111/mmi.13737}, pmid = {28640457}, issn = {1365-2958}, mesh = {Alanine/metabolism ; Amino Acid Sequence ; Catalytic Domain ; Enzymes/*genetics ; Escherichia coli/genetics ; Genome/genetics ; Genome, Bacterial/genetics ; Lyases/*genetics/metabolism ; Metabolic Networks and Pathways ; Thermotoga maritima/genetics ; Wolbachia/genetics ; }, abstract = {The first cells probably possessed rudimentary metabolic networks, built using a handful of multifunctional enzymes. The promiscuous activities of modern enzymes are often assumed to be relics of this primordial era; however, by definition these activities are no longer physiological. There are many fewer examples of enzymes using a single active site to catalyze multiple physiologically-relevant reactions. Previously, we characterized the promiscuous alanine racemase (ALR) activity of Escherichia coli cystathionine β-lyase (CBL). Now we have discovered that several bacteria with reduced genomes lack alr, but contain metC (encoding CBL). We characterized the CBL enzymes from three of these: Pelagibacter ubique, the Wolbachia endosymbiont of Drosophila melanogaster (wMel) and Thermotoga maritima. Each is a multifunctional CBL/ALR. However, we also show that CBL activity is no longer required in these bacteria. Instead, the wMel and T. maritima enzymes are physiologically bi-functional alanine/glutamate racemases. They are not highly active, but they are clearly sufficient. Given the abundance of the microorganisms using them, we suggest that much of the planet's biochemistry is carried out by enzymes that are quite different from the highly-active exemplars usually found in textbooks. Instead, primordial-like enzymes may be an essential part of the adaptive strategy associated with streamlining.}, }
@article {pmid28631141, year = {2018}, author = {Lee, KR and Wakeel, A and Chakraborty, P and Foote, CS and Kajiura, L and Barrozo, JC and Chan, AC and Bazarov, AV and Spitler, R and Kutny, PM and Denegre, JM and Taft, RA and Seemann, J and Rice, BW and Contag, CH and Rutt, BK and Bell, CB}, title = {Cell Labeling with Magneto-Endosymbionts and the Dissection of the Subcellular Location, Fate, and Host Cell Interactions.}, journal = {Molecular imaging and biology}, volume = {20}, number = {1}, pages = {55-64}, pmid = {28631141}, issn = {1860-2002}, support = {T32 CA009695/CA/NCI NIH HHS/United States ; R43 EB019239/EB/NIBIB NIH HHS/United States ; T32 CA 009695/CA/NCI NIH HHS/United States ; R44 EB019239/EB/NIBIB NIH HHS/United States ; R43EB019239/EB/NIBIB NIH HHS/United States ; R43 TR001202/TR/NCATS NIH HHS/United States ; R01 EB019458/EB/NIBIB NIH HHS/United States ; S10 RR026351/RR/NCRR NIH HHS/United States ; R43TR001202/TR/NCATS NIH HHS/United States ; R01 GM096070/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Autophagy ; *Cell Communication ; Cell Line, Tumor ; *Cell Tracking ; Contrast Media/chemistry ; Ferrozine/metabolism ; Humans ; Iron/metabolism ; Magnetite Nanoparticles/*chemistry/ultrastructure ; Mice, Inbred BALB C ; Rats ; Reproducibility of Results ; *Staining and Labeling ; Subcellular Fractions/metabolism ; *Symbiosis ; }, abstract = {PURPOSE: The purposes of this study are to characterize magneto-endosymbiont (ME) labeling of mammalian cells and to discern the subcellular fate of these living contrast agents. MEs are novel magnetic resonance imaging (MRI) contrast agents that are being used for cell tracking studies. Understanding the fate of MEs in host cells is valuable for designing in vivo cell tracking experiments.<br><br>PROCEDURES: The ME's surface epitopes, contrast-producing paramagnetic magnetosomal iron, and genome were studied using immunocytochemistry (ICC), Fe and MRI contrast measurements, and quantitative polymerase chain reaction (qPCR), respectively. These assays, coupled with other common assays, enabled validation of ME cell labeling and dissection of ME subcellular processing.<br><br>RESULTS: The assays mentioned above provide qualitative and quantitative assessments of cell labeling, the subcellular localization and the fate of MEs. ICC results, with an ME-specific antibody, qualitatively shows homogenous labeling with MEs. The ferrozine assay shows that MEs have an average of 7&#xa0;fg Fe/ME, &#x223c;30&#xa0;% of which contributes to MRI contrast and ME-labeled MDA-MB-231 (MDA-231) cells generally have 2.4&#xa0;pg Fe/cell, implying &#x223c;350 MEs/cell. Adjusting the concentration of Fe in the ME growth media reduces the concentration of non-MRI contrast-producing Fe. Results from the qPCR assay, which quantifies ME genomes in labeled cells, shows that processing of MEs begins within 24&#xa0;h in MDA-231 cells. ICC results suggest this intracellular digestion of MEs occurs by the lysosomal degradation pathway. MEs coated with listeriolysin O (LLO) are able to escape the primary phagosome, but subsequently co-localize with LC3, an autophagy-associated molecule, and are processed for digestion. In embryos, where autophagy is transiently suppressed, MEs show an increased capacity for survival and even replication. Finally, transmission electron microscopy (TEM) of ME-labeled MDA-231 cells confirms that the magnetosomes (the MRI contrast-producing particles) remain intact and enable in vivo cell tracking.<br><br>CONCLUSIONS: MEs are used to label mammalian cells for the purpose of cell tracking in vivo, with MRI. Various assays described herein (ICC, ferrozine, and qPCR) allow qualitative and quantitative assessments of labeling efficiency and provide a detailed understanding of subcellular processing of MEs. In some cell types, MEs are digested, but the MRI-producing particles remain. Coating with LLO allows MEs to escape the primary phagosome, enhances retention slightly, and confirms that MEs are ultimately processed by autophagy. Numerous intracellular bacteria and all endosymbiotically derived organelles have evolved molecular mechanisms to avoid intracellular clearance, and identification of the specific processes involved in ME clearance provides a framework on which to develop MEs with enhanced retention in mammalian cells.}, }
@article {pmid28624393, year = {2017}, author = {Keeling, PJ and McCutcheon, JP}, title = {Endosymbiosis: The feeling is not mutual.}, journal = {Journal of theoretical biology}, volume = {434}, number = {}, pages = {75-79}, pmid = {28624393}, issn = {1095-8541}, support = {NNA17BB05A//Intramural NASA/United States ; }, mesh = {*Biological Evolution ; Eukaryota/genetics ; Genome/*genetics ; Organelles/genetics ; *Symbiosis ; }, abstract = {Endosymbiosis is an idea that provided a remarkable amount of explanatory power about the origins of eukaryotic organelles. But it also promoted a number of assumptions that have also been influential, but are less well-examined. Here we look at two of these to see whether or not they fit current evidence. The assumption we first address is that endosymbiotic relationships such as nutritional symbioses and eukaryotic organelles are mutualisms. We argue instead that they are more one-sided associations that can be regarded as context-dependent power struggles like any other ecological interaction. The second assumption is that during endosymbiotic interactions (such as the origin of organelles), the host genomes will acquire a great many genes from endosymbionts that assume functions in host systems (as opposed to the well-documented genes whose products are simply targeted back to the endosymbiont or organelle). The idea that these genes exist in large numbers has been influential in a number of hypotheses about organelle evolution and distribution, but in the most carefully-examined systems no such mass migration of genes is evident. Overall, we argue that both the nature and impact of endosymbiosis need to be constantly re-evaluated to fully understand what roles it really plays in both cell biology and evolution.}, }
@article {pmid28619535, year = {2017}, author = {A D Neilson, J and Rangsrikitphoti, P and Durnford, DG}, title = {Evolution and regulation of Bigelowiella natans light-harvesting antenna system.}, journal = {Journal of plant physiology}, volume = {217}, number = {}, pages = {68-76}, doi = {10.1016/j.jplph.2017.05.019}, pmid = {28619535}, issn = {1618-1328}, mesh = {Acclimatization ; Biological Evolution ; Fluorescence ; Gene Expression Regulation ; Light-Harvesting Protein Complexes/*metabolism/physiology ; Molecular Structure ; Photosystem I Protein Complex/genetics/metabolism ; Photosystem II Protein Complex/genetics/metabolism ; Phylogeny ; Rhizaria/genetics/*metabolism/physiology ; Sequence Analysis, DNA ; Sequence Homology ; }, abstract = {Bigelowiella natans is a mixotrophic flagellate and member of the chlorarachniophytes (Rhizaria), whose plastid is derived from a green algal endosymbiont. With the completion of the B. natans nuclear genome we are able to begin the analysis of the structure, function and evolution of the photosynthetic apparatus. B. natans has undergone substantial changes in photosystem structure during the evolution of the plastid from a green alga. While Photosystem II (PSII) composition is well conserved, Photosystem I (PSI) composition has undergone a dramatic reduction in accessory protein subunits. Coinciding with these changes, there was a loss of green algal LHCI orthologs while the PSII-like antenna system has the expected green algal-like proteins (encoded by genes Lhcbm1-8, Lhcb4). There are also a collection of LHCX-like proteins, which are commonly associated with stramenopiles and other eukaryotes with red-algal derived plastids, along with two other unique classes of LHCs- LHCY and LHCZ- whose function remains cryptic. To understand the regulation of the LHC gene family as an initial probe of function, we conducted an RNA-seq experiment under a short-term, high-light (HL) and low-light stress. The most abundant LHCII transcript (Lhcbm6) plus two other LHCBM types (Lhcbm1, 2) were down regulated under HL and up-regulated following a shift to very-low light (VL), as is common in antenna specializing in light harvesting. Many of the other LHCII and LHCY genes had a small, but significant increase in HL and most were only moderately affected under VL. The LHCX and LHCZ genes, however, had a strong up-regulation under HL-stress and most declined under VL, suggesting that they primarily have a role in photoprotection. This contrasts to the LHCY family that is only moderately responsive to light and a much higher basal level of expression, despite being within the LHCSR/LHCX clade. The expression of LHCX/Z proteins under HL-stress may be related to the induction of long-term, non-photochemical quenching mechanisms.}, }
@article {pmid28618183, year = {2017}, author = {Hussain, M and Akutse, KS and Ravindran, K and Lin, Y and Bamisile, BS and Qasim, M and Dash, CK and Wang, L}, title = {Effects of different temperature regimes on survival of Diaphorina citri and its endosymbiotic bacterial communities.}, journal = {Environmental microbiology}, volume = {19}, number = {9}, pages = {3439-3449}, doi = {10.1111/1462-2920.13821}, pmid = {28618183}, issn = {1462-2920}, mesh = {Animals ; China ; Citrus/*parasitology ; Halomonadaceae/genetics/*growth &amp; development ; Hemiptera/*microbiology ; Hot Temperature ; Real-Time Polymerase Chain Reaction ; Symbiosis/*physiology ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {The Asian citrus psyllid, Diaphorina citri, is a major pest of citrus and vector of citrus greening (huanglongbing) in Asian. In our field-collected psyllid samples, we discovered that Fuzhou (China) and Faisalabad (Pakistan), populations harbored an obligate primary endosymbiont Candidatus Carsonella (gen. nov.) with a single species, Candidatus Carsonella ruddii (sp. nov.) and a secondary endosymbiont, Wolbachia surface proteins (WSP) which are intracellular endosymbionts residing in the bacteriomes. Responses of these symbionts to different temperatures were examined and their host survival assessed. Diagnostic PCR assays showed that the endosymbionts infection rates were not significantly reduced in both D. citri populations after 24 h exposure to cold or heat treatments. Although quantitative PCR assays showed significant reduction of WSP relative densities at 40°C for 24 h, a substantial decrease occurred as the exposure duration increased beyond 3 days. Under the same temperature regimes, Ca. C. ruddii density was initially less affected during the first exposure day, but rapidly reduced at 3-5 days compared to WSP. However, the mortality of the psyllids increased rapidly as exposure time to heat treatment increased. The responses of the two symbionts to unfavorable temperature regimes highlight the complex host-symbionts interactions between D. citri and its associated endosymbionts.}, }
@article {pmid28617844, year = {2017}, author = {Bhattacharya, T and Newton, ILG and Hardy, RW}, title = {Wolbachia elevates host methyltransferase expression to block an RNA virus early during infection.}, journal = {PLoS pathogens}, volume = {13}, number = {6}, pages = {e1006427}, pmid = {28617844}, issn = {1553-7374}, support = {R21 AI121849/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA (Cytosine-5-)-Methyltransferases/genetics/*metabolism ; Drosophila Proteins/genetics/*metabolism ; Drosophila melanogaster/*enzymology/microbiology/physiology/*virology ; Host-Pathogen Interactions ; Sindbis Virus/*physiology ; Symbiosis ; Virus Replication ; Wolbachia/*physiology ; }, abstract = {Wolbachia pipientis is an intracellular endosymbiont known to confer host resistance against RNA viruses in insects. However, the causal mechanism underlying this antiviral defense remains poorly understood. To this end, we have established a robust arthropod model system to study the tripartite interaction involving Sindbis virus and Wolbachia strain wMel within its native host, Drosophila melanogaster. By leveraging the power of Drosophila genetics and a parallel, highly tractable D. melanogaster derived JW18 cell culture system, we determined that in addition to reducing infectious virus production, Wolbachia negatively influences Sindbis virus particle infectivity. This is further accompanied by reductions in viral transcript and protein levels. Interestingly, unchanged ratio of proteins to viral RNA copies suggest that Wolbachia likely does not influence the translational efficiency of viral transcripts. Additionally, expression analyses of candidate host genes revealed D. melanogaster methyltransferase gene Mt2 as an induced host factor in the presence of Wolbachia. Further characterization of viral resistance in Wolbachia-infected flies lacking functional Mt2 revealed partial recovery of virus titer relative to wild-type, accompanied by complete restoration of viral RNA and protein levels, suggesting that Mt2 acts at the stage of viral genome replication. Finally, knockdown of Mt2 in Wolbachia uninfected JW18 cells resulted in increased virus infectivity, thus demonstrating its previously unknown role as an antiviral factor against Sindbis virus. In conclusion, our findings provide evidence supporting the role of Wolbachia-modulated host factors towards RNA virus resistance in arthropods, alongside establishing Mt2's novel antiviral function against Sindbis virus in D. melanogaster.}, }
@article {pmid28616842, year = {2018}, author = {Brewer, KD and Spitler, R and Lee, KR and Chan, AC and Barrozo, JC and Wakeel, A and Foote, CS and Machtaler, S and Rioux, J and Willmann, JK and Chakraborty, P and Rice, BW and Contag, CH and Bell, CB and Rutt, BK}, title = {Characterization of Magneto-Endosymbionts as MRI Cell Labeling and Tracking Agents.}, journal = {Molecular imaging and biology}, volume = {20}, number = {1}, pages = {65-73}, pmid = {28616842}, issn = {1860-2002}, support = {T32 CA009695/CA/NCI NIH HHS/United States ; RT2-02018//California Institute for Regenerative Medicine/International ; 1R43TR001202-01/NH/NIH HHS/United States ; T32 CA 009695/CA/NCI NIH HHS/United States ; R43 TR001202/TR/NCATS NIH HHS/United States ; S10 RR026351/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Cell Line, Tumor ; Cell Survival ; *Cell Tracking ; Female ; Humans ; *Magnetic Resonance Imaging ; Magnetite Nanoparticles/*chemistry ; Mice, Nude ; *Symbiosis ; }, abstract = {PURPOSE: Magneto-endosymbionts (MEs) show promise as living magnetic resonance imaging (MRI) contrast agents for in vivo cell tracking. Here we characterize the biomedical imaging properties of ME contrast agents, in vitro and in vivo.<br><br>PROCEDURES: By adapting and engineering magnetotactic bacteria to the intracellular niche, we are creating magneto-endosymbionts (MEs) that offer advantages relative to passive iron-based contrast agents (superparamagnetic iron oxides, SPIOs) for cell tracking. This work presents a biomedical imaging characterization of MEs including: MRI transverse relaxivity (r 2) for MEs and ME-labeled cells (compared to a commercially available iron oxide nanoparticle); microscopic validation of labeling efficiency and subcellular locations; and in vivo imaging of a MDA-MB-231BR (231BR) human breast cancer cells in a mouse brain.<br><br>RESULTS: At 7T, r 2 relaxivity of bare MEs was higher (250&#xa0;s[-1]&#xa0;mM[-1]) than that of conventional SPIO (178&#xa0;s[-1]&#xa0;mM[-1]). Optimized in vitro loading of MEs into 231BR cells yielded 1-4&#xa0;pg iron/cell (compared to 5-10&#xa0;pg iron/cell for conventional SPIO). r 2 relaxivity dropped by a factor of ~3 upon loading into cells, and was on the same order of magnitude for ME-loaded cells compared to SPIO-loaded cells. In vivo, ME-labeled cells exhibited strong MR contrast, allowing as few as 100 cells to be detected in mice using an optimized 3D SPGR gradient-echo sequence.<br><br>CONCLUSIONS: Our results demonstrate the potential of magneto-endosymbionts as living MR contrast agents. They have r 2 relaxivity values comparable to traditional iron oxide nanoparticle contrast agents, and provide strong MR contrast when loaded into cells and implanted in tissue.}, }
@article {pmid28612849, year = {2017}, author = {Hansen, AK and Skidmore, IH}, title = {Psyllids, It's What's on the Inside That Counts: Community Cross Talk Facilitates Prophage Interactions.}, journal = {mSphere}, volume = {2}, number = {3}, pages = {}, pmid = {28612849}, issn = {2379-5042}, abstract = {Despite the availability of massive microbial community data sets (e.g., metagenomes), there is still a lack of knowledge on what molecular mechanisms facilitate cross talk between microbes and prophage within a community context. A study published in mSphere by Jain and colleagues (M. Jain, L. A. Fleites, and D. W. Gabriel, mSphere 2:e00171-17, 2017, https://doi.org/10.1128/mSphereDirect.00171-17) reports on an intriguing new twist of how a prophage of the bacterium "Candidatus Liberibacter asiaticus" may have its lytic cycle suppressed partly because of a protein that is expressed by a cooccurring bacterium, Wolbachia. Both of these microbes coexist along with other microbial tenants inside their sap-feeding insect host, a psyllid. Although these results are still preliminary and alternative hypotheses need to be tested, these results suggest an interesting new dimension on how regulation of microbial genomes occurs in a community context.}, }
@article {pmid28611430, year = {2017}, author = {Tsao, HF and Scheikl, U and Volland, JM and Köhsler, M and Bright, M and Walochnik, J and Horn, M}, title = {'Candidatus Cochliophilus cryoturris' (Coxiellaceae), a symbiont of the testate amoeba Cochliopodium minus.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {3394}, pmid = {28611430}, issn = {2045-2322}, support = {I 1628/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Amebiasis/*microbiology ; Amoebida/*classification/isolation &amp; purification ; Coxiellaceae/*physiology ; *Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S ; *Symbiosis ; }, abstract = {Free-living amoebae are well known for their role in controlling microbial community composition through grazing, but some groups, namely Acanthamoeba species, also frequently serve as hosts for bacterial symbionts. Here we report the first identification of a bacterial symbiont in the testate amoeba Cochliopodium. The amoeba was isolated from a cooling tower water sample and identified as C. minus. Fluorescence in situ hybridization and transmission electron microscopy revealed intracellular symbionts located in vacuoles. 16S rRNA-based phylogenetic analysis identified the endosymbiont as member of a monophyletic group within the family Coxiellaceae (Gammaprotebacteria; Legionellales), only moderately related to known amoeba symbionts. We propose to tentatively classify these bacteria as 'Candidatus Cochliophilus cryoturris'. Our findings add both, a novel group of amoeba and a novel group of symbionts, to the growing list of bacteria-amoeba relationships.}, }
@article {pmid28609446, year = {2017}, author = {Murray, RL and Herridge, EJ and Ness, RW and Bussière, LF}, title = {Are sex ratio distorting endosymbionts responsible for mating system variation among dance flies (Diptera: Empidinae)?.}, journal = {PloS one}, volume = {12}, number = {6}, pages = {e0178364}, pmid = {28609446}, issn = {1932-6203}, mesh = {Animals ; Biological Evolution ; Diptera/classification/*microbiology ; Female ; Host-Pathogen Interactions ; Linear Models ; Male ; Reproduction ; Rickettsia/*physiology ; Sex Ratio ; Species Specificity ; Spiroplasma/*physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Maternally inherited bacterial endosymbionts are common in many arthropod species. Some endosymbionts cause female-biased sex ratio distortion in their hosts that can result in profound changes to a host's mating behaviour and reproductive biology. Dance flies (Diptera: Empidinae) are well known for their unusual reproductive biology, including species with female-specific ornamentation and female-biased lek-like swarming behaviour. The cause of the repeated evolution of female ornaments in these flies remains unknown, but is probably associated with female-biased sex ratios in individual species. In this study we assessed whether dance flies harbour sex ratio distorting endosymbionts that might have driven these mating system evolutionary changes. We measured the incidence and prevalence of infection by three endosymbionts that are known to cause female-biased sex ratios in other insect hosts (Wolbachia, Rickettsia and Spiroplasma) across 20 species of dance flies. We found evidence of widespread infection by all three symbionts and variation in sex-specific prevalence across the taxa sampled. However, there was no relationship between infection prevalence and adult sex ratio measures and no evidence that female ornaments are associated with high prevalences of sex-biased symbiont infections. We conclude that the current distribution of endosymbiont infections is unlikely to explain the diversity in mating systems among dance fly species.}, }
@article {pmid28608866, year = {2017}, author = {Jain, M and Fleites, LA and Gabriel, DW}, title = {A Small Wolbachia Protein Directly Represses Phage Lytic Cycle Genes in "Candidatus Liberibacter asiaticus" within Psyllids.}, journal = {mSphere}, volume = {2}, number = {3}, pages = {}, pmid = {28608866}, issn = {2379-5042}, abstract = {Huanglongbing (HLB) is a severe disease of citrus caused by an uncultured alphaproteobacterium "Candidatus Liberibacter asiaticus" and transmitted by Asian citrus psyllids (Diaphorina citri). Two prophage genomes, SC1 and SC2, integrated in "Ca. Liberibacter asiaticus" strain UF506 were described previously, and very similar prophages are found resident in the majority of "Ca. Liberibacter asiaticus" strains described worldwide. The SC1 lytic cycle is marked by upregulation of prophage late genes, including a functional holin (SC1_gp110); these late genes are activated when "Ca. Liberibacter asiaticus" is in planta, but not when infecting the psyllid host. We previously reported that the holin promoter is strongly and constitutively active in Liberibacter crescens (a cultured proxy for uncultured "Ca. Liberibacter asiaticus") but is suppressed in a dose-dependent manner by crude aqueous extracts from D. citri applied exogenously. Here we report that the suppressor activity of the crude psyllid extract was heat labile and abolished by proteinase K treatment, indicating a proteinaceous repressor and of a size smaller than 30 kDa. The repressor was affinity captured from D. citri aqueous extracts using biotinylated holin promoter DNA immobilized on magnetic beads and subjected to liquid chromatography-tandem mass spectrometry (LC-MS/MS). Protein database interrogation was used to identify a small DNA-binding protein encoded by a gene carried by Wolbachia strain wDi, a resident endosymbiont of D. citri as the repressor. The in vitro-translated Wolbachia repressor protein was able to penetrate L. crescens cells, bind to "Ca. Liberibacter asiaticus" promoter DNA, and partially suppress holin promoter-driven β-glucuronidase (GUS) activity, indicating potential involvement of an additional interacting partner(s) or posttranslational modification(s) for complete suppression. Expression of the Wolbachia repressor protein appeared to be constitutive irrespective of "Ca. Liberibacter asiaticus" infection status of the insect host. IMPORTANCE Host acquisition of a new microbial species can readily perturb the dynamics of preexisting microbial associations. Molecular cross talk between microbial associates may be necessary for efficient resource allocation and enhanced survival. Classic examples involve quorum sensing (QS), which detects population densities and is both used and coopted to control expression of bacterial genes, including host adaptation factors. We report that a 56-amino-acid repressor protein made by the resident psyllid endosymbiont Wolbachia can enter cells of Liberibacter crescens, a cultured proxy for the uncultured psyllid endosymbiont "Ca. Liberibacter asiaticus" and repress "Ca. Liberibacter asiaticus" phage lytic cycle genes. Such repression in "Ca. Liberibacter asiaticus" may be critical to survival of both endosymbionts, since phage-mediated lysis would likely breach the immunogenic threshold of the psyllid, invoking a systemic and nonspecific innate immune reaction.}, }
@article {pmid28607056, year = {2017}, author = {Yang, S and Wang, Q and Fedorova, E and Liu, J and Qin, Q and Zheng, Q and Price, PA and Pan, H and Wang, D and Griffitts, JS and Bisseling, T and Zhu, H}, title = {Microsymbiont discrimination mediated by a host-secreted peptide in Medicago truncatula.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {26}, pages = {6848-6853}, pmid = {28607056}, issn = {1091-6490}, mesh = {*Medicago truncatula/genetics/metabolism/microbiology ; Nitrogen Fixation/*physiology ; *Plant Proteins/genetics/metabolism ; *Rhizome/genetics/metabolism/microbiology ; *Root Nodules, Plant/genetics/metabolism/microbiology ; Sinorhizobium meliloti/*metabolism ; Symbiosis/*physiology ; *Transaminases/genetics/metabolism ; }, abstract = {The legume-rhizobial symbiosis results in the formation of root nodules that provide an ecological niche for nitrogen-fixing bacteria. However, plant-bacteria genotypic interactions can lead to wide variation in nitrogen fixation efficiency, and it is not uncommon that a bacterial strain forms functional (Fix[+]) nodules on one plant genotype but nonfunctional (Fix[-]) nodules on another. Host genetic control of this specificity is unknown. We herein report the cloning of the Medicago truncatula NFS1 gene that regulates the fixation-level incompatibility with the microsymbiont Sinorhizobium meliloti Rm41. We show that NFS1 encodes a nodule-specific cysteine-rich (NCR) peptide. In contrast to the known role of NCR peptides as effectors of endosymbionts' differentiation to nitrogen-fixing bacteroids, we demonstrate that specific NCRs control discrimination against incompatible microsymbionts. NFS1 provokes bacterial cell death and early nodule senescence in an allele-specific and rhizobial strain-specific manner, and its function is dependent on host genetic background.}, }
@article {pmid28600542, year = {2017}, author = {Ye, Z and Vollhardt, IMG and Girtler, S and Wallinger, C and Tomanovic, Z and Traugott, M}, title = {An effective molecular approach for assessing cereal aphid-parasitoid-endosymbiont networks.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {3138}, pmid = {28600542}, issn = {2045-2322}, mesh = {Animals ; Aphids/classification/genetics/*parasitology ; Edible Grain/*parasitology ; Europe ; Host-Parasite Interactions ; Multiplex Polymerase Chain Reaction/*methods ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, RNA ; Symbiosis ; }, abstract = {Molecular approaches are increasingly being used to analyse host-parasitoid food webs as they overcome several hurdles inherent to conventional approaches. However, such studies have focused primarily on the detection and identification of aphids and their aphidiid primary parasitoids, largely ignoring primary parasitoid-hyperparasitoid interactions or limiting these to a few common species within a small geographical area. Furthermore, the detection of bacterial secondary endosymbionts has not been considered in such assays despite the fact that endosymbionts may alter aphid-parasitoid interactions, as they can confer protection against parasitoids. Here we present a novel two-step multiplex PCR (MP-PCR) protocol to assess cereal aphid-primary parasitoid-hyperparasitoid-endosymbiont interactions. The first step of the assay allows detection of parasitoid DNA at a general level (24 primary and 16 hyperparasitoid species) as well as the species-specific detection of endosymbionts (3 species) and cereal aphids (3 species). The second step of the MP-PCR assay targets seven primary and six hyperparasitoid species that commonly occur in Central Europe. Additional parasitoid species not covered by the second-step of the assay can be identified via sequencing 16S rRNA amplicons generated in the first step of the assay. The approach presented here provides an efficient, highly sensitive, and cost-effective (~consumable costs of 1.3 € per sample) tool for assessing cereal aphid-parasitoid-endosymbiont interactions.}, }
@article {pmid28599659, year = {2017}, author = {Duchemin, JB and Mee, PT and Lynch, SE and Vedururu, R and Trinidad, L and Paradkar, P}, title = {Zika vector transmission risk in temperate Australia: a vector competence study.}, journal = {Virology journal}, volume = {14}, number = {1}, pages = {108}, pmid = {28599659}, issn = {1743-422X}, mesh = {Animals ; Australia ; Climate ; Disease Transmission, Infectious ; Gastrointestinal Tract/*virology ; Humans ; Mosquito Vectors/*virology ; RNA, Viral/*analysis/genetics ; Real-Time Polymerase Chain Reaction ; Risk Assessment ; Saliva/*virology ; Zika Virus/genetics/*isolation &amp; purification ; Zika Virus Infection/transmission ; }, abstract = {BACKGROUND: Zika virus is an emerging pathogen of global importance. It has been responsible for recent outbreaks in the Americas and in the Pacific region. This study assessed five different mosquito species from the temperate climatic zone in Australia and included Aedes albopictus as a potentially invasive species.<br><br>METHODS: Mosquitoes were orally challenged by membrane feeding with Zika virus strain of Cambodia 2010 origin, belonging to the Asian clade. Virus infection and dissemination were assessed by quantitative PCR on midgut and carcass after dissection. Transmission was assessed by determination of cytopathogenic effect of saliva (CPE) on Vero cells, followed by determination of 50% tissue culture infectious dose (TCID50) for CPE positive samples. Additionally, the presence of Wolbachia endosymbiont infection was assessed by qPCR and standard PCR.<br><br>RESULTS: Culex mosquitoes were found unable to present Zika virus in saliva, as demonstrated by molecular as well as virological methods. Aedes aegypti, was used as a positive control for Zika infection and showed a high level of virus infection, dissemination and transmission. Local Aedes species, Ae. notoscriptus and, to a lesser degree, Ae. camptorhynchus were found to expel virus in their saliva and contained viral nucleic acid within the midgut. Molecular assessment identified low or no dissemination for these species, possibly due to low virus loads. Ae. albopictus from Torres Strait islands origin was shown as an efficient vector. Cx quinquefasciatus was shown to harbour Wolbachia endosymbionts at high prevalence, whilst no Wolbachia was found in Cx annulirostris. The Australian Ae. albopictus population was shown to harbour Wolbachia at high frequency.<br><br>CONCLUSIONS: The risk of local Aedes species triggering large Zika epidemics in the southern parts of Australia is low. The potentially invasive Ae. albopictus showed high prevalence of virus in the saliva and constitutes a potential threat if this mosquito species becomes established in mainland Australia. Complete risk analysis of Zika transmission in the temperate zone would require an assessment of the impact of temperature on Zika virus replication within local and invasive mosquito species.}, }
@article {pmid28596296, year = {2017}, author = {Camacho, M and Oliva, M and Serbus, LR}, title = {Dietary saccharides and sweet tastants have differential effects on colonization of Drosophila oocytes by Wolbachia endosymbionts.}, journal = {Biology open}, volume = {6}, number = {7}, pages = {1074-1083}, pmid = {28596296}, issn = {2046-6390}, support = {R25 GM061347/GM/NIGMS NIH HHS/United States ; }, abstract = {Wolbachia bacteria are widespread, maternally transmitted endosymbionts of insects. Maintenance of sufficient Wolbachia titer in maternal germline cells is required for transmission efficacy. The mechanisms that regulate Wolbachia titer are not well understood; however, dietary sucrose was reported to elevate oocyte Wolbachia titer in Drosophila melanogaster whereas dietary yeast decreased oocyte titer. To further investigate how oocyte Wolbachia titer is controlled, this study analyzed the response of wMel Wolbachia to diets enriched in an array of natural sugars and other sweet tastants. Confocal imaging of D. melanogaster oocytes showed that food enriched in dietary galactose, lactose, maltose and trehalose elevated Wolbachia titer. However, oocyte Wolbachia titers were unaffected by exposure to the sweet tastants lactulose, erythritol, xylitol, aspartame and saccharin as compared to the control. Oocyte size was generally non-responsive to the nutrient-altered diets. Ovary size, however, was consistently smaller in response to all sugar- and sweetener-enriched diets. Furthermore, most dietary sugars administered in tandem with dietary yeast conferred complete rescue of oocyte titer suppression by yeast. All diets dually enriched in yeast and sugar also rescued yeast-associated ovary volume changes. This indicates oocyte colonization by Wolbachia to be a nutritionally sensitive process regulated by multiple mechanistic inputs.}, }
@article {pmid28591835, year = {2017}, author = {Miura, T and Moriya, H and Iwai, S}, title = {Assessing phagotrophy in the mixotrophic ciliate Paramecium bursaria using GFP-expressing yeast cells.}, journal = {FEMS microbiology letters}, volume = {364}, number = {12}, pages = {}, doi = {10.1093/femsle/fnx117}, pmid = {28591835}, issn = {1574-6968}, mesh = {Chlorella vulgaris/physiology ; Green Fluorescent Proteins/*genetics ; Paramecium/*genetics/growth &amp; development/*physiology ; *Phagocytosis ; Photosynthesis ; Saccharomyces cerevisiae/*genetics ; Symbiosis ; Vacuoles ; }, abstract = {We used cells of the yeast Saccharomyces cerevisiae expressing green fluorescent protein (GFP) as fluorescently labelled prey to assess the phagocytic activities of the mixotrophic ciliate Paramecium bursaria, which harbours symbiotic Chlorella-like algae. Because of different fluorescence spectra of GFP and algal chlorophyll, ingested GFP-expressing yeast cells can be distinguished from endosymbiotic algal cells and directly counted in individual P. bursaria cells using fluorescence microscopy. By using GFP-expressing yeast cells, we found that P. bursaria altered ingestion activities under different physiological conditions, such as different growth phases or the presence/absence of endosymbionts. Use of GFP-expressing yeast cells allowed us to estimate the digestion rates of live prey of the ciliate. In contrast to the ingestion activities, the digestion rate within food vacuoles was not affected by the presence of endosymbionts, consistent with previous findings that food and perialgal vacuoles are spatially and functionally separated in P. bursaria. Thus, GFP-expressing yeast may provide a valuable tool to assess both ingestion and digestion activities of ciliates that feed on eukaryotic organisms.}, }
@article {pmid28587661, year = {2017}, author = {Morrow, JL and Hall, AAG and Riegler, M}, title = {Symbionts in waiting: the dynamics of incipient endosymbiont complementation and replacement in minimal bacterial communities of psyllids.}, journal = {Microbiome}, volume = {5}, number = {1}, pages = {58}, pmid = {28587661}, issn = {2049-2618}, mesh = {Alphaproteobacteria/classification/isolation &amp; purification ; Animals ; Bacteria/*classification/isolation &amp; purification ; Gammaproteobacteria/classification/isolation &amp; purification ; Hemiptera/classification/*growth &amp; development/microbiology ; High-Throughput Nucleotide Sequencing/*methods ; Host Specificity ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA/*methods ; Symbiosis ; }, abstract = {BACKGROUND: Obligate bacterial primary (P-) endosymbionts that are maternally inherited and codiverge with hosts are widespread across insect lineages with nutritionally restricted diets. Secondary (S-) endosymbionts are mostly facultative, but in some hosts, they complement P-endosymbiont function and therefore become obligate. Phylogenetic evidence exists for host switching and replacement of S-endosymbionts. The community dynamics that precede endosymbiont replacement and complementation have been little studied across host species, yet they are fundamental to the evolution of endosymbiosis.<br><br>RESULTS: We performed bacterial 16S rRNA gene amplicon sequencing of 25 psyllid species (Hemiptera, Psylloidea) across different developmental stages and ecological niches by focusing on the characterisation of the bacteria other than the universally present P-endosymbiont Carsonella (Gammaproteobacteria). Most species harboured only one dominant representative of diverse gammaproteobacterial S-endosymbionts that was consistently detected across all host individuals and populations (Arsenophonus in eight species, Sodalis or Sodalis-like bacteria in four species, unclassified Enterobacteriaceae in eight species). The identity of this dominant obligate S-endosymbiont varied across closely related host species. Unexpectedly, five psyllid species had two or three co-occurring endosymbiont species other than Carsonella within all host individuals, including a Rickettsiella-like bacterium (Gammaproteobacteria) in one psyllid species. Based on standard and quantitative PCR, all psyllids carried Carsonella, at higher titres than their dominant S-endosymbionts. Some psyllids also had Alphaproteobacteria (Lariskella, Rickettsia, Wolbachia) at varying prevalence. Incidence of other bacteria, including known plant pathogens, was low. Ecological niche of gall-forming, lerp-forming and free-living psyllid species did not impact endosymbiont communities. Two flush-feeding psyllid species had population-specific differences, and this was attributable to the higher endosymbiont diversity in native ranges and the absence of some endosymbionts in invasive ranges.<br><br>CONCLUSIONS: Our data support the hypothesis of strict vertical transmission of minimal core communities of bacteria in psyllids. We also found evidence for S-endosymbiont replacement across closely related psyllid species. Multiple dominant S-endosymbionts present in some host species, including at low titre, constitute potential examples of incipient endosymbiont complementation or replacement. Our multiple comparisons of deep-sequenced minimal insect bacterial communities exposed the dynamics involved in shaping insect endosymbiosis.}, }
@article {pmid28585301, year = {2017}, author = {Lin, M and Bachman, K and Cheng, Z and Daugherty, SC and Nagaraj, S and Sengamalay, N and Ott, S and Godinez, A and Tallon, LJ and Sadzewicz, L and Fraser, C and Dunning Hotopp, JC and Rikihisa, Y}, title = {Analysis of complete genome sequence and major surface antigens of Neorickettsia helminthoeca, causative agent of salmon poisoning disease.}, journal = {Microbial biotechnology}, volume = {10}, number = {4}, pages = {933-957}, pmid = {28585301}, issn = {1751-7915}, support = {U19 AI110820/AI/NIAID NIH HHS/United States ; R01 AI047885/AI/NIAID NIH HHS/United States ; HHSN272200900009C/AI/NIAID NIH HHS/United States ; }, mesh = {Anaplasmataceae Infections/microbiology/*veterinary ; Animals ; Antibodies, Bacterial/blood ; Antigens, Bacterial/*genetics ; Antigens, Surface/*genetics ; Blotting, Western ; Dog Diseases/*microbiology ; Dogs ; *Genome, Bacterial ; Metabolic Networks and Pathways/genetics ; Neorickettsia/*genetics/isolation &amp; purification ; *Whole Genome Sequencing ; }, abstract = {Neorickettsia helminthoeca, a type species of the genus Neorickettsia, is an endosymbiont of digenetic trematodes of veterinary importance. Upon ingestion of salmonid fish parasitized with infected trematodes, canids develop salmon poisoning disease (SPD), an acute febrile illness that is particularly severe and often fatal in dogs without adequate treatment. We determined and analysed the complete genome sequence of N. helminthoeca: a single small circular chromosome of 884 232 bp encoding 774 potential proteins. N. helminthoeca is unable to synthesize lipopolysaccharides and most amino acids, but is capable of synthesizing vitamins, cofactors, nucleotides and bacterioferritin. N. helminthoeca is, however, distinct from majority of the family Anaplasmataceae to which it belongs, as it encodes nearly all enzymes required for peptidoglycan biosynthesis, suggesting its structural hardiness and inflammatory potential. Using sera from dogs that were experimentally infected by feeding with parasitized fish or naturally infected in southern California, Western blot analysis revealed that among five predicted N. helminthoeca outer membrane proteins, P51 and strain-variable surface antigen were uniformly recognized. Our finding will help understanding pathogenesis, prevalence of N. helminthoeca infection among trematodes, canids and potentially other animals in nature to develop effective SPD diagnostic and preventive measures. Recent progresses in large-scale genome sequencing have been uncovering broad distribution of Neorickettsia spp., the comparative genomics will facilitate understanding of biology and the natural history of these elusive environmental bacteria.}, }
@article {pmid28566542, year = {2017}, author = {Miyata, M and Konagaya, T and Yukuhiro, K and Nomura, M and Kageyama, D}, title = {Wolbachia-induced meiotic drive and feminization is associated with an independent occurrence of selective mitochondrial sweep in a butterfly.}, journal = {Biology letters}, volume = {13}, number = {5}, pages = {}, pmid = {28566542}, issn = {1744-957X}, mesh = {Animals ; Butterflies ; DNA, Mitochondrial ; Female ; Feminization ; Male ; Mitochondria ; Sex Ratio ; *Wolbachia ; }, abstract = {Maternally inherited Wolbachia endosymbionts manipulate arthropod reproduction in various ways. In the butterfly Eurema mandarina, a cytoplasmic incompatibility-inducing Wolbachia strain wCI and the associated mtDNA haplotypes are known to originate from the sister species Eurema hecabe, which offered a good case study for microbe-mediated hybrid introgression. Besides wCI, some females with the Z0 karyotype harbour a distinct Wolbachia strain wFem, which causes all-female production by meiotic drive and feminization. We report that a considerable proportion of E. mandarina females (65.7%) were infected with both wCI and wFem (CF) on Tanegashima Island. While females singly infected with wCI (C) produced offspring at a 1 : 1 sex ratio, CF females produced only females. Although Z-linked sequence polymorphism showed no signs of divergence between C and CF females, mtDNA split into two discrete clades; one consisted of C females and the other CF females, both of which formed a clade with E. hecabe but not with uninfected E. mandarina This suggests that CF matrilines also, but independently, experienced a selective sweep after hybrid introgression from E. hecabe Distinct evolutionary forces were suggested to have caused C and CF matrilines to diverge, which would be irreversible because of the particular phenotype of wFem.}, }
@article {pmid28566541, year = {2017}, author = {Parker, BJ and McLean, AHC and Hrček, J and Gerardo, NM and Godfray, HCJ}, title = {Establishment and maintenance of aphid endosymbionts after horizontal transfer is dependent on host genotype.}, journal = {Biology letters}, volume = {13}, number = {5}, pages = {}, pmid = {28566541}, issn = {1744-957X}, mesh = {Animals ; Aphids ; Gene Transfer, Horizontal ; Genotype ; *Symbiosis ; }, abstract = {Animal-associated microbial communities have important effects on host phenotypes. Individuals within and among species differ in the strains and species of microbes that they harbour, but how natural selection shapes the distribution and abundance of symbionts in natural populations is not well understood. Symbionts can be beneficial in certain environments but also impose costs on their hosts. Consequently, individuals that can or cannot associate with symbionts will be favoured under different ecological circumstances. As a result, we predict that individuals within a species vary in terms of how well they accept and maintain symbionts. In pea aphids, the frequency of endosymbionts varies among host-plant-associated populations ('biotypes'). We show that aphid genotypes from different biotypes vary in how well they accept and maintain symbionts after horizontal transfer. We find that aphids from biotypes that frequently harbour symbionts are better able to associate with novel symbionts than those from biotypes that less frequently harbour symbionts. Intraspecific variation in the ability of hosts to interact with symbionts is an understudied factor explaining patterns of host-symbiont association.}, }
@article {pmid28561954, year = {2017}, author = {Medrano, EG and Grauke, LJ and Stanford, RL and Thompson, TE}, title = {Evidence for the presence of a bacterial endosymbiont in the pecan scab pathogen Venturia effusa (basyonym: Fusicladium effusum).}, journal = {Journal of applied microbiology}, volume = {123}, number = {2}, pages = {491-497}, doi = {10.1111/jam.13503}, pmid = {28561954}, issn = {1365-2672}, mesh = {Ascomycota/genetics/isolation &amp; purification/*physiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Carya/*microbiology ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; In Situ Hybridization, Fluorescence ; Plant Diseases/*microbiology ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {AIMS: To determine whether Venturia effusa, the causative fungal agent of pecan scab, harbours a bacterial symbiont.<br><br>METHODS AND RESULTS: Venturia effusa isolates were maintained on potato dextrose agar amended with antibiotics (chloramphenicol (100&#xa0;&#x3bc;g&#xa0;ml[-1]) and tetracycline 100&#xa0;(&#x3bc;g&#xa0;ml[-1])). Genomic DNA extracted from mycelia was used to target eubacterial 16S rDNA. A 1&#xb7;4-kbp PCR amplified product using 16S rDNA degenerate primers was cloned, sequenced and found to have 99% identities with Actinobacteria representatives. Attempts to culture the detected bacteria apart from the fungus following agitation and fungal cell lysis were unsuccessful using standard bacteriological media under either aerobic or anaerobic conditions. Fungal structures were visualized using scanning electron microscopy and putative bacterial formations associated with the fungal mycelia were observed. Fluorescence in&#xa0;situ hybridization using 16S rDNA oligonucleotides illuminated spores and portions of the hyphae.<br><br>CONCLUSIONS: This is the first report to provide both molecular microbiological and microscopic evidence in support of the hypothesis that V.&#xa0;effusa harbours endosymbiotic bacteria.<br><br>Findings from this research contribute fundamental information regarding the biology of the fungus that may ultimately lead to identifying a target of the pathogen for use in management and/or avoidance strategies.}, }
@article {pmid28559331, year = {2017}, author = {O'Neil, PK and Richardson, LGL and Paila, YD and Piszczek, G and Chakravarthy, S and Noinaj, N and Schnell, D}, title = {The POTRA domains of Toc75 exhibit chaperone-like function to facilitate import into chloroplasts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {24}, pages = {E4868-E4876}, pmid = {28559331}, issn = {1091-6490}, support = {K22 AI113078/AI/NIAID NIH HHS/United States ; P41 GM103622/GM/NIGMS NIH HHS/United States ; R01 GM061893/GM/NIGMS NIH HHS/United States ; S10 OD018090/OD/NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Arabidopsis/genetics/metabolism ; Arabidopsis Proteins/*chemistry/genetics/*metabolism ; Binding Sites ; Chloroplasts/*metabolism ; Crystallography, X-Ray ; Membrane Proteins/*chemistry/genetics/*metabolism ; Models, Biological ; Models, Molecular ; Molecular Chaperones/chemistry/genetics/metabolism ; Protein Domains ; Protein Precursors/*chemistry/genetics/*metabolism ; Protein Transport ; Static Electricity ; }, abstract = {Protein trafficking across membranes is an essential function in cells; however, the exact mechanism for how this occurs is not well understood. In the endosymbionts, mitochondria and chloroplasts, the vast majority of proteins are synthesized in the cytoplasm as preproteins and then imported into the organelles via specialized machineries. In chloroplasts, protein import is accomplished by the TOC (translocon on the outer chloroplast membrane) and TIC (translocon on the inner chloroplast membrane) machineries in the outer and inner envelope membranes, respectively. TOC mediates initial recognition of preproteins at the outer membrane and includes a core membrane channel, Toc75, and two receptor proteins, Toc33/34 and Toc159, each containing GTPase domains that control preprotein binding and translocation. Toc75 is predicted to have a β-barrel fold consisting of an N-terminal intermembrane space (IMS) domain and a C-terminal 16-stranded β-barrel domain. Here we report the crystal structure of the N-terminal IMS domain of Toc75 from Arabidopsis thaliana, revealing three tandem polypeptide transport-associated (POTRA) domains, with POTRA2 containing an additional elongated helix not observed previously in other POTRA domains. Functional studies show an interaction with the preprotein, preSSU, which is mediated through POTRA2-3. POTRA2-3 also was found to have chaperone-like activity in an insulin aggregation assay, which we propose facilitates preprotein import. Our data suggest a model in which the POTRA domains serve as a binding site for the preprotein as it emerges from the Toc75 channel and provide a chaperone-like activity to prevent misfolding or aggregation as the preprotein traverses the intermembrane space.}, }
@article {pmid28558648, year = {2017}, author = {Ho, PT and Park, E and Hong, SG and Kim, EH and Kim, K and Jang, SJ and Vrijenhoek, RC and Won, YJ}, title = {Geographical structure of endosymbiotic bacteria hosted by Bathymodiolus mussels at eastern Pacific hydrothermal vents.}, journal = {BMC evolutionary biology}, volume = {17}, number = {1}, pages = {121}, pmid = {28558648}, issn = {1471-2148}, mesh = {Animals ; Antarctic Regions ; Bacteria/*classification/genetics ; Biological Evolution ; Genetics, Population ; Hybridization, Genetic ; *Hydrothermal Vents ; Mytilidae/classification/genetics/*microbiology/physiology ; Pacific Ocean ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {BACKGROUND: Chemolithoautotrophic primary production sustains dense invertebrate communities at deep-sea hydrothermal vents and hydrocarbon seeps. Symbiotic bacteria that oxidize dissolved sulfur, methane, and hydrogen gases nourish bathymodiolin mussels that thrive in these environments worldwide. The mussel symbionts are newly acquired in each generation via infection by free-living forms. This study examined geographical subdivision of the thiotrophic endosymbionts hosted by Bathymodiolus mussels living along the eastern Pacific hydrothermal vents. High-throughput sequencing data of 16S ribosomal RNA encoding gene and fragments of six protein-coding genes of symbionts were examined in the samples collected from nine vent localities at the East Pacific Rise, Galápagos Rift, and Pacific-Antarctic Ridge.<br><br>RESULTS: Both of the parapatric sister-species, B. thermophilus and B. antarcticus, hosted the same numerically dominant phylotype of thiotrophic Gammaproteobacteria. However, sequences from six protein-coding genes revealed highly divergent symbiont lineages living north and south of the Easter Microplate and hosted by these two Bathymodiolus mussel species. High heterogeneity of symbiont haplotypes among host individuals sampled from the same location suggested that stochasticity associated with initial infections was amplified as symbionts proliferated within the host individuals. The mussel species presently contact one another and hybridize along the Easter Microplate, but the northern and southern symbionts appear to be completely isolated. Vicariance associated with orogeny of the Easter Microplate region, 2.5-5.3 million years ago, may have initiated isolation of the symbiont and host populations. Estimates of synonymous substitution rates for the protein-coding bacterial genes examined in this study were 0.77-1.62%/nucleotide/million years.<br><br>CONCLUSIONS: Our present study reports the most comprehensive population genetic analyses of the chemosynthetic endosymbiotic bacteria based on high-throughput genetic data and extensive geographical sampling to date, and demonstrates the role of the geographical features, the Easter Microplate and geographical distance, in the intraspecific divergence of this bacterial species along the mid-ocean ridge axes in the eastern Pacific. Altogether, our results provide insights into extrinsic and intrinsic factors affecting the dispersal and evolution of chemosynthetic symbiotic partners in the hydrothermal vents along the eastern Pacific Ocean.}, }
@article {pmid28556617, year = {2017}, author = {Izawa, K and Kuwahara, H and Sugaya, K and Lo, N and Ohkuma, M and Hongoh, Y}, title = {Discovery of ectosymbiotic Endomicrobium lineages associated with protists in the gut of stolotermitid termites.}, journal = {Environmental microbiology reports}, volume = {9}, number = {4}, pages = {411-418}, doi = {10.1111/1758-2229.12549}, pmid = {28556617}, issn = {1758-2229}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Eukaryota/*physiology ; Gastrointestinal Tract/microbiology ; Isoptera/microbiology/*parasitology/physiology ; Phylogeny ; *Symbiosis ; }, abstract = {The genus Endomicrobium is a dominant bacterial group in the gut of lower termites, and most phylotypes are intracellular symbionts of gut protists. Here we report the discovery of Endomicrobium ectosymbionts of termite gut protists. We found that bristle-like Endomicrobium cells attached to the surface of spirotrichosomid protist cells inhabiting the termite Stolotermes victoriensis. Transmission electron microscopy revealed that a putative Endomicrobium cell likely attached to the protist surface via a protrusion from the tip of the bacterium. A phylotype, sharing 98.9% 16S rRNA sequence identity with the Endomicrobium ectosymbionts of the spirotrichosomid protists, was also found on the cell surface of the protist Trichonympha magna in the gut of the termite Porotermes adamsoni. We propose the novel species 'Candidatus Endomicrobium superficiale' for these bacteria. T. magna simultaneously harboured another Endomicrobium ectosymbiont that shared 93.5-94.2% 16S rRNA sequence identities with 'Ca. Endomicrobium superficiale'. Furthermore, Spirotrichonympha-like protists in P. adamsoni guts were associated with an Endomicrobium phylotype that possibly attached to the host flagella. A phylogenetic analysis suggested that these ectosymbiotic lineages have evolved multiple times from free-living Endomicrobium lineages and are relatively distant from the endosymbionts. Our results provide novel insights into the ecology and evolution of the Endomicrobium.}, }
@article {pmid28549825, year = {2017}, author = {Mergaert, P and Kikuchi, Y and Shigenobu, S and Nowack, ECM}, title = {Metabolic Integration of Bacterial Endosymbionts through Antimicrobial Peptides.}, journal = {Trends in microbiology}, volume = {25}, number = {9}, pages = {703-712}, doi = {10.1016/j.tim.2017.04.007}, pmid = {28549825}, issn = {1878-4380}, mesh = {Anti-Infective Agents/*metabolism ; Bacteria/genetics/*metabolism ; *Bacterial Physiological Phenomena ; Genome, Bacterial ; Phylogeny ; *Symbiosis ; }, abstract = {Antimicrobial peptides (AMPs) are massively produced by eukaryotic hosts during symbiotic interactions with bacteria. Among other roles, these symbiotic AMPs have the capacity to permeabilize symbiont membranes and facilitate metabolite flow across the host-symbiont interface. We propose that an ancestral role of these peptides is to facilitate metabolic exchange between the symbiotic partners through membrane permeabilization. This function may be particularly critical for integration of endosymbiont and host metabolism in interactions involving bacteria with strongly reduced genomes lacking most small metabolite transporters. Moreover, AMPs could have acted in a similar way at the onset of plastid and mitochondrion evolution, after a host cell took up a bacterium and needed to extract nutrients from it in the absence of dedicated solute transporters.}, }
@article {pmid28545568, year = {2017}, author = {Wang, R and Li, N and Liu, J and Li, T and Liu, M and Yu, Z and Liu, J}, title = {Symbiont dynamics of the Tibetan tick Haemaphysalis tibetensis (Acari: Ixodidae).}, journal = {Parasites &amp; vectors}, volume = {10}, number = {1}, pages = {259}, pmid = {28545568}, issn = {1756-3305}, mesh = {Animals ; Coxiella/genetics/isolation &amp; purification/*physiology ; Female ; Ixodidae/*microbiology/physiology ; Male ; Nymph/microbiology ; Phylogeny ; Rickettsia/genetics/isolation &amp; purification/*physiology ; Salivary Glands/microbiology ; *Symbiosis ; Tibet ; }, abstract = {BACKGROUND: Characterization of the microbial diversity and symbiont dynamics of ticks may help to understand the development of ticks and reveal new strategies to control tick-transmitted pathogens, which has not yet been explored in the Tibetan tick Haemaphysalis tibetensis. This tick species is widely distributed in the Tibetan Plateau, and is recognized as one of the primary parasites affecting domestic and wild animals.<br><br>METHODS: In the present study, the endosymbionts of H. tibetensis were characterized using diagnostic polymerase chain reaction (diagnostic PCR), and further evaluated for tissue distribution and population dynamics at each developmental stage of ticks and in tissues at different reproductive statuses by real-time quantitative polymerase chain reaction (RT-qPCR).<br><br>RESULTS: Two symbionts were found in H. tibetensis, and named as CLS-Ht (Coxiella-like symbiont in H. tibetensis) and RLS-Ht (Rickettsia-like symbiont in H. tibetensis). They showed 100% infection rate in both females and males of H. tibetensis. CLS-Ht and RLS-Ht can be observed within eggs, larvae, nymphs and adults, which indicates vertical transmission in H. tibetensis. CLS-Ht was specifically distributed in the female ovaries and Malpighian tubules, whereas RLS-Ht was detected within ovaries, Malpighian tubules, salivary glands and midguts of the ticks. Real-time qPCR suggested that adult ticks carried the largest amount of CLS-Ht and RLS-Ht with CLS-Ht having a significantly higher presence in females than in males (P&#x2009;<&#x2009;0.05), whereas the presence of RLS-Ht showed no significant differences between sexes. In the ovaries, CLS-Ht distribution reached a peak at one day post-engorgement, and then gradually declined to a lower level, whereas no change was observed in RLS-Ht. In Malpighian tubules, the amount of both symbionts displayed an increasing trend with time post-engorgement. In midguts and salivary glands, the amount of RLS-Ht showed no significant differences.<br><br>CONCLUSION: Two novel endosymbionts (CLS-Ht and RLS-Ht) were characterized in H. tibetensis both showing a high prevalence and stable vertical transmission. The described tissue distribution and population dynamics might imply the important functions of these symbionts during the development and reproduction of ticks.}, }
@article {pmid28544184, year = {2018}, author = {Bodył, A}, title = {Did some red alga-derived plastids evolve via kleptoplastidy? A hypothesis.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {93}, number = {1}, pages = {201-222}, doi = {10.1111/brv.12340}, pmid = {28544184}, issn = {1469-185X}, mesh = {*Biological Evolution ; Dinoflagellida/genetics/physiology ; Models, Biological ; Plastids/*genetics/physiology ; Rhodophyta/*genetics/*physiology ; }, abstract = {The evolution of plastids has a complex and still unresolved history. These organelles originated from a cyanobacterium via primary endosymbiosis, resulting in three eukaryotic lineages: glaucophytes, red algae, and green plants. The red and green algal plastids then spread via eukaryote-eukaryote endosymbioses, known as secondary and tertiary symbioses, to numerous heterotrophic protist lineages. The number of these horizontal plastid transfers, especially in the case of red alga-derived plastids, remains controversial. Some authors argue that the number of plastid origins should be minimal due to perceived difficulties in the transformation of a eukaryotic algal endosymbiont into a multimembrane plastid, but increasingly the available data contradict this argument. I suggest that obstacles in solving this dilemma result from the acceptance of a single evolutionary scenario for the endosymbiont-to-plastid transformation formulated by Cavalier-Smith &amp; Lee (1985). Herein I discuss data that challenge this evolutionary scenario. Moreover, I propose a new model for the origin of multimembrane plastids belonging to the red lineage and apply it to the dinoflagellate peridinin plastid. The new model has several general and practical implications, such as the requirement for a new definition of cell organelles and in the construction of chimeric organisms.}, }
@article {pmid28542621, year = {2017}, author = {Tamura, M and Kageyama, D and Honda, N and Fujimoto, H and Kato, A}, title = {Enzymatic activity necessary to restore the lethality due to Escherichia coli RNase E deficiency is distributed among bacteria lacking RNase E homologues.}, journal = {PloS one}, volume = {12}, number = {5}, pages = {e0177915}, pmid = {28542621}, issn = {1932-6203}, mesh = {Animals ; Computer Simulation ; Endoribonucleases/chemistry/deficiency/genetics/*metabolism ; Escherichia coli/enzymology/*genetics ; Female ; *Genetic Engineering ; Mutation ; Phenotype ; *Sequence Homology, Amino Acid ; Symbiosis ; Wolbachia/enzymology ; }, abstract = {Escherichia coli RNase E (Eco-RNase E), encoded by rne (Eco-rne), is considered the global RNA decay initiator. Although Eco-RNase E is an essential gene product in E. coli, some bacterial species, such as Bacillus subtilis, do not possess Eco-RNase E sequence homologues. B. subtilis instead possesses RNase J1/J2 (Bsu-RNase J1/J2) and RNase Y (Bsu-RNase Y) to execute RNA decay. Here we found that E. coli lacking the Eco-rne gene (Δrne E. coli) was viable conditional on M9 minimal media by introducing Bsu-RNase J1/J2 or Bsu-RNase Y. We also cloned an extremely short Eco-RNase E homologue (Wpi-RNase E) and a canonical sized Bsu-RNase J1/J2 homologue (Wpi-RNase J) from Wolbachia pipientis, an α-proteobacterial endosymbiont of arthropods. We found that Wpi-RNase J restored the colony-forming ability (CFA) of Δrne E. coli, whereas Wpi-RNase E did not. Unexpectedly, Wpi-RNase E restored defective CFA due to lack of Eco-RNase G, a paralogue of Eco-RNase E. Our results indicate that bacterial species that lack Eco-RNase E homologues or bacterial species that possess Eco-RNase E homologues which lack Eco-RNase E-like activities have a modest Eco-RNase E-like function using RNase J and/or RNase Y. These results suggest that Eco-RNase E-like activities might distribute among a wide array of bacteria and that functions of RNases may have changed dynamically during evolutionary divergence of bacterial lineages.}, }
@article {pmid28539635, year = {2017}, author = {Onuma, R and Mishra, N and Miyagishima, SY}, title = {Regulation of chloroplast and nucleomorph replication by the cell cycle in the cryptophyte Guillardia theta.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {2345}, pmid = {28539635}, issn = {2045-2322}, mesh = {Algal Proteins/genetics/metabolism ; Amino Acid Sequence ; *Cell Cycle ; Cell Division ; Cell Nucleus/genetics/*metabolism ; Chloroplasts/genetics/*metabolism ; Cryptophyta/classification/genetics/*metabolism ; *DNA Replication ; Gene Expression ; Histones/genetics/metabolism ; Phylogeny ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; Time Factors ; }, abstract = {The chloroplasts of cryptophytes arose through a secondary endosymbiotic event in which a red algal endosymbiont was integrated into a previously nonphotosynthetic eukaryote. The cryptophytes retain a remnant of the endosymbiont nucleus (nucleomorph) that is replicated once in the cell cycle along with the chloroplast. To understand how the chloroplast, nucleomorph and host cell divide in a coordinated manner, we examined the expression of genes/proteins that are related to nucleomorph replication and chloroplast division as well as the timing of nuclear and nucleomorph DNA synthesis in the cryptophyte Guillardia theta. Nucleus-encoded nucleomorph HISTONE H2A mRNA specifically accumulated during the nuclear S phase. In contrast, nucleomorph-encoded genes/proteins that are related to nucleomorph replication and chloroplast division (FtsZ) are constantly expressed throughout the cell cycle. The results of this study and previous studies on chlorarachniophytes suggest that there was a common evolutionary pattern in which an endosymbiont lost its replication cycle-dependent transcription while cell-cycle-dependent transcriptional regulation of host nuclear genes came to restrict the timing of nucleomorph replication and chloroplast division.}, }
@article {pmid28533374, year = {2017}, author = {Takano, SI and Tuda, M and Takasu, K and Furuya, N and Imamura, Y and Kim, S and Tashiro, K and Iiyama, K and Tavares, M and Amaral, AC}, title = {Unique clade of alphaproteobacterial endosymbionts induces complete cytoplasmic incompatibility in the coconut beetle.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {23}, pages = {6110-6115}, pmid = {28533374}, issn = {1091-6490}, mesh = {Alphaproteobacteria/genetics/metabolism/*pathogenicity ; Animals ; Arthropods/genetics ; Bacteroidetes/genetics ; Biological Control Agents ; Coleoptera/metabolism/*microbiology ; Cytoplasm/microbiology ; Extrachromosomal Inheritance ; Genetic Speciation ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Reproduction ; Reproductive Isolation ; Symbiosis/physiology ; Wolbachia/metabolism ; }, abstract = {Maternally inherited bacterial endosymbionts in arthropods manipulate host reproduction to increase the fitness of infected females. Cytoplasmic incompatibility (CI) is one such manipulation, in which uninfected females produce few or no offspring when they mate with infected males. To date, two bacterial endosymbionts, Wolbachia and Cardinium, have been reported as CI inducers. Only Wolbachia induces complete CI, which causes 100% offspring mortality in incompatible crosses. Here we report a third CI inducer that belongs to a unique clade of Alphaproteobacteria detected within the coconut beetle, Brontispa longissima This beetle comprises two cryptic species, the Asian clade and the Pacific clade, which show incompatibility in hybrid crosses. Different bacterial endosymbionts, a unique clade of Alphaproteobacteria in the Pacific clade and Wolbachia in the Asian clade, induced bidirectional CI between hosts. The former induced complete CI (100% mortality), whereas the latter induced partial CI (70% mortality). Illumina MiSeq sequencing and denaturing gradient gel electrophoresis patterns showed that the predominant bacterium detected in the Pacific clade of B. longissima was this unique clade of Alphaproteobacteria alone, indicating that this endosymbiont was responsible for the complete CI. Sex distortion did not occur in any of the tested crosses. The 1,160 bp of 16S rRNA gene sequence obtained for this endosymbiont had only 89.3% identity with that of Wolbachia, indicating that it can be recognized as a distinct species. We discuss the potential use of this bacterium as a biological control agent.}, }
@article {pmid28526749, year = {2017}, author = {Pasquali, CC and Islam, Z and Adamoski, D and Ferreira, IM and Righeto, RD and Bettini, J and Portugal, RV and Yue, WW and Gonzalez, A and Dias, SMG and Ambrosio, ALB}, title = {The origin and evolution of human glutaminases and their atypical C-terminal ankyrin repeats.}, journal = {The Journal of biological chemistry}, volume = {292}, number = {27}, pages = {11572-11585}, pmid = {28526749}, issn = {1083-351X}, support = {P41 GM103393/GM/NIGMS NIH HHS/United States ; }, mesh = {Ankyrin Repeat ; Crystallography, X-Ray ; *Evolution, Molecular ; *Glutaminase/chemistry/genetics ; Humans ; Isoenzymes/chemistry/genetics ; *Models, Genetic ; *Models, Molecular ; Protein Domains ; Protein Structure, Quaternary ; }, abstract = {On the basis of tissue-specific enzyme activity and inhibition by catalytic products, Hans Krebs first demonstrated the existence of multiple glutaminases in mammals. Currently, two human genes are known to encode at least four glutaminase isoforms. However, the phylogeny of these medically relevant enzymes remains unclear, prompting us to investigate their origin and evolution. Using prokaryotic and eukaryotic glutaminase sequences, we built a phylogenetic tree whose topology suggested that the multidomain architecture was inherited from bacterial ancestors, probably simultaneously with the hosting of the proto-mitochondrion endosymbiont. We propose an evolutionary model wherein the appearance of the most active enzyme isoform, glutaminase C (GAC), which is expressed in many cancers, was a late retrotransposition event that occurred in fishes from the Chondrichthyes class. The ankyrin (ANK) repeats in the glutaminases were acquired early in their evolution. To obtain information on ANK folding, we solved two high-resolution structures of the ANK repeat-containing C termini of both kidney-type glutaminase (KGA) and GLS2 isoforms (glutaminase B and liver-type glutaminase). We found that the glutaminase ANK repeats form unique intramolecular contacts through two highly conserved motifs; curiously, this arrangement occludes a region usually involved in ANK-mediated protein-protein interactions. We also solved the crystal structure of full-length KGA and present a small-angle X-ray scattering model for full-length GLS2. These structures explain these proteins' compromised ability to assemble into catalytically active supra-tetrameric filaments, as previously shown for GAC. Collectively, these results provide information about glutaminases that may aid in the design of isoform-specific glutaminase inhibitors.}, }
@article {pmid28512149, year = {2017}, author = {VanHook, AM}, title = {Quorum sensing to repress virulence.}, journal = {Science signaling}, volume = {10}, number = {479}, pages = {}, doi = {10.1126/scisignal.aan6287}, pmid = {28512149}, issn = {1937-9145}, abstract = {A quorum-sensing system of an insect endosymbiont enables the bacterium to establish persistent infection by inhibiting the expression of virulence genes.}, }
@article {pmid28505340, year = {2017}, author = {Msaddak, A and Rejili, M and Durán, D and Rey, L and Imperial, J and Palacios, JM and Ruiz-Argüeso, T and Mars, M}, title = {Members of Microvirga and Bradyrhizobium genera are native endosymbiotic bacteria nodulating Lupinus luteus in Northern Tunisian soils.}, journal = {FEMS microbiology ecology}, volume = {93}, number = {6}, pages = {}, doi = {10.1093/femsec/fix068}, pmid = {28505340}, issn = {1574-6941}, mesh = {Bacterial Proteins/genetics ; Bradyrhizobium/classification/*genetics/isolation &amp; purification ; DNA Gyrase/genetics ; DNA, Bacterial/genetics ; Genes, Essential/genetics ; Lupinus/*microbiology ; Methylobacteriaceae/classification/*genetics/isolation &amp; purification ; Multilocus Sequence Typing ; Phylogeny ; Rec A Recombinases/genetics ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Soil ; Soil Microbiology ; Symbiosis/genetics/*physiology ; Tunisia ; }, abstract = {The genetic diversity of bacterial populations nodulating Lupinus luteus (yellow lupine) in Northern Tunisia was examined. Phylogenetic analyses of 43 isolates based on recA and gyrB partial sequences grouped them in three clusters, two of which belong to genus Bradyrhizobium (41 isolates) and one, remarkably, to Microvirga (2 isolates), a genus never previously described as microsymbiont of this lupine species. Representatives of the three clusters were analysed in-depth by multilocus sequence analysis of five housekeeping genes (rrs, recA, glnII, gyrB and dnaK). Surprisingly, the Bradyrhizobium cluster with the two isolates LluI4 and LluTb2 may constitute a new species defined by a separate position between Bradyrhizobium manausense and B. denitrificans. A nodC-based phylogeny identified only two groups: one formed by Bradyrhizobium strains included in the symbiovar genistearum and the other by the Microvirga strains. Symbiotic behaviour of representative isolates was tested, and among the seven legumes inoculated only a difference was observed i.e. the Bradyrhizobium strains nodulated Ornithopus compressus unlike the two strains of Microvirga. On the basis of these data, we conclude that L. luteus root nodule symbionts in Northern Tunisia are mostly strains within the B. canariense/B. lupini lineages, and the remaining strains belong to two groups not previously identified as L. luteus endosymbionts: one corresponding to a new clade of Bradyrhizobium and the other to the genus Microvirga.}, }
@article {pmid28505238, year = {2017}, author = {Karut, K and Mete Karaca, M and Döker, I and Kazak, C}, title = {Analysis of Species, Subgroups, and Endosymbionts of Bemisia tabaci (Hemiptera: Aleyrodidae) From Southwestern Cotton Fields in Turkey.}, journal = {Environmental entomology}, volume = {46}, number = {4}, pages = {1035-1040}, doi = {10.1093/ee/nvx093}, pmid = {28505238}, issn = {1938-2936}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Female ; Gossypium/growth &amp; development ; Hemiptera/*classification/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; *Symbiosis ; Turkey ; }, abstract = {Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide including Turkey. Although there are substantial data regarding species composition of Turkish B. tabaci populations, the situation is still not clear and further investigations are needed. Therefore, in this study, species and subgroups of B. tabaci collected from cotton fields in southwestern part of Turkey (Antalya, Aydın, Denizli, and Muğla) were determined using microsatellite analysis, AluI-based mtCOI polymerase chain reaction-random length polymorphism, and sequencing. Secondary endosymbionts were also determined using diagnostic species-specific PCR. Middle East Asia Minor 1 (MEAM1), Mediterranean (MED) Q1, and MED Q2 were the species and subgroups found in this study. The MED species (85.3%) were found to be more dominant than MEAM1. Species status of B. tabaci varied depending on the location. Although all samples collected from Aydın were found to be Q1, three species and subgroups were found in Muğla. Secondary endosymbionts varied according to species and subgroups. Arsenophonus was found only from Q2, while Hamiltonella was detected in MEAM1 and Q1. In addition, high Rickettsia and low Wolbachia infections were detected in MEAM1 and Q1 populations, respectively. In conclusion, for the first time, we report the presence and symbiotic communities of Q1 from Turkey. We also found that the symbiont complement of the Q1 is more congruent with Q1 from Greece than other regions of the world, which may have some interesting implications for movement of this invasive subgroup.}, }
@article {pmid28503372, year = {2017}, author = {Gurfield, N and Grewal, S and Cua, LS and Torres, PJ and Kelley, ST}, title = {Endosymbiont interference and microbial diversity of the Pacific coast tick, Dermacentor occidentalis, in San Diego County, California.}, journal = {PeerJ}, volume = {5}, number = {}, pages = {e3202}, pmid = {28503372}, issn = {2167-8359}, abstract = {The Pacific coast tick, Dermacentor occidentalis Marx, is found throughout California and can harbor agents that cause human diseases such as anaplasmosis, ehrlichiosis, tularemia, Rocky Mountain spotted fever and rickettsiosis 364D. Previous studies have demonstrated that nonpathogenic endosymbiotic bacteria can interfere with Rickettsia co-infections in other tick species. We hypothesized that within D. occidentalis ticks, interference may exist between different nonpathogenic endosymbiotic or nonendosymbiotic bacteria and Spotted Fever group Rickettsia (SFGR). Using PCR amplification and sequencing of the rompA gene and intergenic region we identified a cohort of SFGR-infected and non-infected D. occidentalis ticks collected from San Diego County. We then amplified a partial segment of the 16S rRNA gene and used next-generation sequencing to elucidate the microbiomes and levels of co-infection in the ticks. The SFGR R. philipii str. 364D and R. rhipicephali were detected in 2.3% and 8.2% of the ticks, respectively, via rompA sequencing. Interestingly, next generation sequencing revealed an inverse relationship between the number of Francisella-like endosymbiont (FLE) 16S rRNA sequences and Rickettsia 16S rRNA sequences within individual ticks that is consistent with partial interference between FLE and SFGR infecting ticks. After excluding the Rickettsia and FLE endosymbionts from the analysis, there was a small but significant difference in microbial community diversity and a pattern of geographic isolation by distance between collection locales. In addition, male ticks had a greater diversity of bacteria than female ticks and ticks that weren't infected with SFGR had similar microbiomes to canine skin microbiomes. Although experimental studies are required for confirmation, our findings are consistent with the hypothesis that FLEs and, to a lesser extent, other bacteria, interfere with the ability of D. occidentalis to be infected with certain SFGR. The results also raise interesting possibilities about the effects of putative vertebrate hosts on the tick microbiome.}, }
@article {pmid28498102, year = {2017}, author = {Dorrell, RG and Gile, G and McCallum, G and Méheust, R and Bapteste, EP and Klinger, CM and Brillet-Guéguen, L and Freeman, KD and Richter, DJ and Bowler, C}, title = {Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome.}, journal = {eLife}, volume = {6}, number = {}, pages = {}, pmid = {28498102}, issn = {2050-084X}, mesh = {Chloroplast Proteins/*genetics ; *Evolution, Molecular ; Haptophyta/*classification/*genetics ; Stramenopiles/*classification/*genetics ; }, abstract = {Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid-targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid-targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.}, }
@article {pmid28495966, year = {2017}, author = {Gray, MW}, title = {Lynn Margulis and the endosymbiont hypothesis: 50 years later.}, journal = {Molecular biology of the cell}, volume = {28}, number = {10}, pages = {1285-1287}, pmid = {28495966}, issn = {1939-4586}, mesh = {Bacteria ; *Biological Evolution ; Cilia ; Eukaryotic Cells ; Mitochondria ; Phylogeny ; Plastids ; *Symbiosis ; }, abstract = {The 1967 article "On the Origin of Mitosing Cells" in the Journal of Theoretical Biology by Lynn Margulis (then Lynn Sagan) is widely regarded as stimulating renewed interest in the long-dormant endosymbiont hypothesis of organelle origins. In her article, not only did Margulis champion an endosymbiotic origin of mitochondria and plastids from bacterial ancestors, but she also posited that the eukaryotic flagellum (undulipodium in her usage) and mitotic apparatus originated from an endosymbiotic, spirochete-like organism. In essence, she presented a comprehensive symbiotic view of eukaryotic cell evolution (eukaryogenesis). Not all of the ideas in her article have been accepted, for want of compelling evidence, but her vigorous promotion of the role of symbiosis in cell evolution unquestionably had a major influence on how subsequent investigators have viewed the origin and evolution of mitochondria and plastids and the eukaryotic cell per se.}, }
@article {pmid28494358, year = {2017}, author = {Rowen, DJ and Templeman, MA and Kingsford, MJ}, title = {Herbicide effects on the growth and photosynthetic efficiency of Cassiopea maremetens.}, journal = {Chemosphere}, volume = {182}, number = {}, pages = {143-148}, doi = {10.1016/j.chemosphere.2017.05.001}, pmid = {28494358}, issn = {1879-1298}, mesh = {Animals ; Diuron/pharmacology ; Herbicides/*pharmacology ; Photosynthesis/drug effects ; Photosystem II Protein Complex/drug effects ; Rhizophoraceae/*drug effects/growth &amp; development/physiology ; Scyphozoa/*drug effects ; Triazines/pharmacology ; Water Pollutants, Chemical/pharmacology ; }, abstract = {Herbicides from agricultural run-off have been measured in coastal systems of the Great Barrier Reef over many years. Non-target herbicide exposure, especially photosystem II herbicides has the potential to affect seagrasses and other marine species. The symbiotic benthic jellyfish Cassiopea maremetens is present in tropical/sub-tropical estuarine and marine environments. Jellyfish (n = 8 per treatment) were exposed to four separate concentrations of agricultural formulations of diuron or hexazinone to determine their sensitivity and potential for recovery to pulsed herbicide exposure. Jellyfish growth, symbiont photosynthetic activity and zooxanthellae density were analysed for herbicide-induced changes for 7 days followed by a 7 day recovery period. Both the jellyfish and endosymbiont were more sensitive to diuron than hexazinone. The 7-day EC50 for jellyfish growth was 0.35 μg L[-1] for Diuron and 17.5 μg L[-1] for Hexazinone respectively. Diuron exposure caused a significant decrease (p < 0.05) in jellyfish growth at 0.1 μg L[-1], a level that is below the regional Great Barrier Reef guideline value. Jellyfish recovery was rapid with growth rates similar to control animals following removal from herbicide exposure. Both diuron and hexazinone caused significant decreases in photosynthetic efficiency (effective quantum yield) in all treatment concentrations (0.1 μg L[-1] and above) and this effect continued in the post-exposure period. As this species is frequently found in near-shore environments, they may be particularly vulnerable to herbicide run-off.}, }
@article {pmid28486424, year = {2017}, author = {Fenner, J and Seltzer, J and Peyton, S and Sullivan, H and Tolson, P and Walsh, RP and Hill, J and Counterman, BA}, title = {Demographic Variation of Wolbachia Infection in the Endangered Mitchell's Satyr Butterfly.}, journal = {Insects}, volume = {8}, number = {2}, pages = {}, pmid = {28486424}, issn = {2075-4450}, abstract = {The Mitchell's satyr, Neonympha mitchellii, is an endangered species that is limited to highly isolated habitats in the northern and southern United States. Conservation strategies for isolated endangered species often implement captive breeding and translocation programs for repopulation. However, these programs risk increasing the spread of harmful pathogens, such as the bacterial endosymbiont Wolbachia. Wolbachia can manipulate the host's reproduction leading to incompatibilities between infected and uninfected hosts. This study uses molecular methods to screen for Wolbachia presence across the distribution of the Mitchell's satyr and its subspecies, St. Francis satyr, which are both federally listed as endangered and are considered two of the rarest butterflies in North America. The screens confirmed the presence of Wolbachia in the northern and newly discovered southern populations of the Mitchell's satyr, but not in the St. Francis satyr population. These results combined with previous reports of Wolbachia in N. mitchellii, highlight that Wolbachia infection varies both geographically and temporally in satyr populations. The temporal variance shows the importance of continued monitoring of Wolbachia infection during conservation programs. To reduce the risk of reproductive incompatibilities, it is advised that all individuals collected for conservation purposes be screened for Wolbachia and recommended to avoid the use of infected individuals for captive breeding and translocation programs.}, }
@article {pmid28471518, year = {2017}, author = {Li, S and Zhou, C and Chen, G and Zhou, Y}, title = {Bacterial microbiota in small brown planthopper populations with different rice viruses.}, journal = {Journal of basic microbiology}, volume = {57}, number = {7}, pages = {590-596}, doi = {10.1002/jobm.201700004}, pmid = {28471518}, issn = {1521-4028}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Hemiptera/*microbiology/virology ; High-Throughput Nucleotide Sequencing ; Insect Vectors/*microbiology/virology ; *Microbiota/genetics ; Oryza ; Plant Viruses/isolation &amp; purification/physiology ; RNA, Ribosomal, 16S ; *Symbiosis ; Tenuivirus/isolation &amp; purification/physiology ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {The small brown planthopper (SBPH) is an important virus vector, transmitting Rice stripe virus (RSV), and Rice black-streaked dwarf virus (RBSDV). Insect symbionts play an essential role in the insect fitness, however, it is still unclear about their contributions to viral transmission by SBPH. Here, we investigated endosymbiont communities in non-viruliferous, RSV-infected, and RBSDV-infected SBPH populations using Illumina 16S rRNA gene MiSeq sequencing. In total, 281,803 effective sequences of the 16S rRNA gene were generated from different samples. Sequence analysis revealed the percentages of these bacterial groups in different SBPH populations on several taxonomic levels ranging from phyla to genera. The extremely consistent bacterial diversity and abundance indicated that RSV or RBSDV infection did not affect the composition and abundance of symbionts in SBPH. It was notable that Wolbachia was dominant in all populations. The symbiosis between Wolbachia and SBPH might be potentially studied and utilized to control pest SBPH in the future.}, }
@article {pmid28462779, year = {2017}, author = {Burns, JA and Zhang, H and Hill, E and Kim, E and Kerney, R}, title = {Transcriptome analysis illuminates the nature of the intracellular interaction in a vertebrate-algal symbiosis.}, journal = {eLife}, volume = {6}, number = {}, pages = {}, pmid = {28462779}, issn = {2050-084X}, mesh = {Ambystoma/genetics/*physiology ; Animals ; Gene Expression Profiling ; Glutamine/metabolism ; Immunity, Innate ; Metabolic Networks and Pathways/genetics ; *Symbiosis ; Volvocida/genetics/*physiology ; }, abstract = {During embryonic development, cells of the green alga Oophila amblystomatis enter cells of the salamander Ambystoma maculatum forming an endosymbiosis. Here, using de novo dual-RNA seq, we compared the host salamander cells that harbored intracellular algae to those without algae and the algae inside the animal cells to those in the egg capsule. This two-by-two-way analysis revealed that intracellular algae exhibit hallmarks of cellular stress and undergo a striking metabolic shift from oxidative metabolism to fermentation. Culturing experiments with the alga showed that host glutamine may be utilized by the algal endosymbiont as a primary nitrogen source. Transcriptional changes in salamander cells suggest an innate immune response to the alga, with potential attenuation of NF-κB, and metabolic alterations indicative of modulation of insulin sensitivity. In stark contrast to its algal endosymbiont, the salamander cells did not exhibit major stress responses, suggesting that the host cell experience is neutral or beneficial.}, }
@article {pmid28455417, year = {2017}, author = {Serbus, LR and Rodriguez, BG and Sharmin, Z and Momtaz, AJMZ and Christensen, S}, title = {Predictive Genomic Analyses Inform the Basis for Vitamin Metabolism and Provisioning in Bacteria-Arthropod Endosymbioses.}, journal = {G3 (Bethesda, Md.)}, volume = {7}, number = {6}, pages = {1887-1898}, pmid = {28455417}, issn = {2160-1836}, mesh = {Animals ; Arthropods/*genetics/*metabolism/microbiology ; Bacteria/*genetics/*metabolism ; Computational Biology/methods ; Databases, Genetic ; Genetic Association Studies ; *Genomics/methods ; Metabolic Networks and Pathways ; Open Reading Frames ; Symbiosis/*genetics ; Vitamins/*metabolism ; }, abstract = {The requirement of vitamins for core metabolic processes creates a unique set of pressures for arthropods subsisting on nutrient-limited diets. While endosymbiotic bacteria carried by arthropods have been widely implicated in vitamin provisioning, the underlying molecular mechanisms are not well understood. To address this issue, standardized predictive assessment of vitamin metabolism was performed in 50 endosymbionts of insects and arachnids. The results predicted that arthropod endosymbionts overall have little capacity for complete de novo biosynthesis of conventional or active vitamin forms. Partial biosynthesis pathways were commonly predicted, suggesting a substantial role in vitamin provisioning. Neither taxonomic relationships between host and symbiont, nor the mode of host-symbiont interaction were clear predictors of endosymbiont vitamin pathway capacity. Endosymbiont genome size and the synthetic capacity of nonsymbiont taxonomic relatives were more reliable predictors. We developed a new software application that also predicted that last-step conversion of intermediates into active vitamin forms may contribute further to vitamin biosynthesis by endosymbionts. Most instances of predicted vitamin conversion were paralleled by predictions of vitamin use. This is consistent with achievement of provisioning in some cases through upregulation of pathways that were retained for endosymbiont benefit. The predicted absence of other enzyme classes further suggests a baseline of vitamin requirement by the majority of endosymbionts, as well as some instances of putative mutualism. Adaptation of this workflow to analysis of other organisms and metabolic pathways will provide new routes for considering the molecular basis for symbiosis on a comprehensive scale.}, }
@article {pmid28454877, year = {2017}, author = {Wernegreen, JJ}, title = {Ancient bacterial endosymbionts of insects: Genomes as sources of insight and springboards for inquiry.}, journal = {Experimental cell research}, volume = {358}, number = {2}, pages = {427-432}, doi = {10.1016/j.yexcr.2017.04.028}, pmid = {28454877}, issn = {1090-2422}, support = {S10 OD018164/OD/NIH HHS/United States ; }, mesh = {Animals ; Base Sequence/*genetics ; *Evolution, Molecular ; Genome/*genetics ; *Genomics ; Humans ; Insecta/*genetics ; Phylogeny ; }, abstract = {Ancient associations between insects and bacteria provide models to study intimate host-microbe interactions. Currently, a wealth of genome sequence data for long-term, obligately intracellular (primary) endosymbionts of insects reveals profound genomic consequences of this specialized bacterial lifestyle. Those consequences include severe genome reduction and extreme base compositions. This minireview highlights the utility of genome sequence data to understand how, and why, endosymbionts have been pushed to such extremes, and to illuminate the functional consequences of such extensive genome change. While the static snapshots provided by individual endosymbiont genomes are valuable, comparative analyses of multiple genomes have shed light on evolutionary mechanisms. Namely, genome comparisons have told us that selection is important in fine-tuning gene content, but at the same time, mutational pressure and genetic drift contribute to genome degradation. Examples from Blochmannia, the primary endosymbiont of the ant tribe Camponotini, illustrate the value and constraints of genome sequence data, and exemplify how genomes can serve as a springboard for further comparative and experimental inquiry.}, }
@article {pmid28453654, year = {2017}, author = {Takishita, K and Takaki, Y and Chikaraishi, Y and Ikuta, T and Ozawa, G and Yoshida, T and Ohkouchi, N and Fujikura, K}, title = {Genomic Evidence that Methanotrophic Endosymbionts Likely Provide Deep-Sea Bathymodiolus Mussels with a Sterol Intermediate in Cholesterol Biosynthesis.}, journal = {Genome biology and evolution}, volume = {9}, number = {5}, pages = {1148-1160}, pmid = {28453654}, issn = {1759-6653}, mesh = {Animals ; Bacteria/*genetics/*metabolism ; Bivalvia/chemistry/cytology/metabolism/*microbiology ; Cell Membrane/chemistry ; Cholesterol/*biosynthesis ; Gene Expression Profiling ; Phylogeny ; Sterols/biosynthesis ; Symbiosis ; }, abstract = {Sterols are key cyclic triterpenoid lipid components of eukaryotic cellular membranes, which are synthesized through complex multi-enzyme pathways. Similar to most animals, Bathymodiolus mussels, which inhabit deep-sea chemosynthetic ecosystems and harbor methanotrophic and/or thiotrophic bacterial endosymbionts, possess cholesterol as their main sterol. Based on the stable carbon isotope analyses, it has been suggested that host Bathymodiolus mussels synthesize cholesterol using a sterol intermediate derived from the methanotrophic endosymbionts. To test this hypothesis, we sequenced the genome of the methanotrophic endosymbiont in Bathymodiolus platifrons. The genome sequence data demonstrated that the endosymbiont potentially generates up to 4,4-dimethyl-cholesta-8,14,24-trienol, a sterol intermediate in cholesterol biosynthesis, from methane. In addition, transcripts for a subset of the enzymes of the biosynthetic pathway to cholesterol downstream from a sterol intermediate derived from methanotroph endosymbionts were detected in our transcriptome data for B. platifrons. These findings suggest that this mussel can de novo synthesize cholesterol from methane in cooperation with the symbionts. By in situ hybridization analyses, we showed that genes associated with cholesterol biosynthesis from both host and endosymbionts were expressed exclusively in the gill epithelial bacteriocytes containing endosymbionts. Thus, cholesterol production is probably localized within these specialized cells of the gill. Considering that the host mussel cannot de novo synthesize cholesterol and depends largely on endosymbionts for nutrition, the capacity of endosymbionts to synthesize sterols may be important in establishing symbiont-host relationships in these chemosynthetic mussels.}, }
@article {pmid28451055, year = {2017}, author = {Sumiya, N and Miyagishima, SY}, title = {Hierarchal order in the formation of chloroplast division machinery in the red alga Cyanidioschyzon merolae.}, journal = {Communicative &amp; integrative biology}, volume = {10}, number = {2}, pages = {e1294298}, pmid = {28451055}, issn = {1942-0889}, abstract = {Chloroplasts have evolved from a cyanobacterial endosymbiont and multiply by dividing. Chloroplast division is performed by constriction of the ring-like protein complex (the PD machinery), which forms at the division site. The PD machinery is composed of cyanobacteria-descended components such as FtsZ and eukaryote-derived proteins such as the dynamin-related protein, DRP5B. In the red alga Cyanidioschyzon merolae, FtsZ ring formation on the stromal side precedes PDR1 and DRP5B ring formation on the cytosolic side. In this study, we impaired FtsZ ring formation in C. merolae by overexpressing FtsZ just before FtsZ ring formation. As a result, PDR1 and DRP5B failed to localize at the chloroplast division site, suggesting that FtsZ ring formation is required for the PDR1 and DRP5B rings. We further found, by expressing a dominant negative form of DRP5B, that DRP5B ring formation begins on the nuclear side of the chloroplast division site. These findings provide insight into how the PD machinery forms in red algae.}, }
@article {pmid28450512, year = {2017}, author = {Riley, AB and Kim, D and Hansen, AK}, title = {Genome Sequence of "Candidatus Carsonella ruddii" Strain BC, a Nutritional Endosymbiont of Bactericera cockerelli.}, journal = {Genome announcements}, volume = {5}, number = {17}, pages = {}, pmid = {28450512}, issn = {2169-8287}, abstract = {Here, we report the genome of "Candidatus Carsonella ruddii" strain BC, a nutritional endosymbiont of the tomato psyllid Bactericera cockerelli The 173,802-bp genome contains 198 protein-coding genes, with a G+C content of 14.8%.}, }
@article {pmid28446677, year = {2017}, author = {Schultz, MJ and Isern, S and Michael, SF and Corley, RB and Connor, JH and Frydman, HM}, title = {Variable Inhibition of Zika Virus Replication by Different Wolbachia Strains in Mosquito Cell Cultures.}, journal = {Journal of virology}, volume = {91}, number = {14}, pages = {}, pmid = {28446677}, issn = {1098-5514}, support = {R01 AI099210/AI/NIAID NIH HHS/United States ; R21 NS101151/NS/NINDS NIH HHS/United States ; R56 AI097589/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes ; Animals ; *Antibiosis ; Cell Line ; Protein Biosynthesis ; RNA, Viral/biosynthesis ; Transcription, Genetic ; Viral Nonstructural Proteins/biosynthesis ; *Virus Replication ; Wolbachia/*physiology ; Zika Virus/*physiology ; }, abstract = {Mosquito-borne arboviruses are a major source of human disease. One strategy to reduce arbovirus disease is to reduce the mosquito's ability to transmit virus. Mosquito infection with the bacterial endosymbiont Wolbachia pipientis wMel is a novel strategy to reduce Aedes mosquito competency for flavivirus infection. However, experiments investigating cyclic environmental temperatures have shown a reduction in maternal transmission of wMel, potentially weakening the integration of this strain into a mosquito population relative to that of other Wolbachia strains. Consequently, it is important to investigate additional Wolbachia strains. All Zika virus (ZIKV) suppression studies are limited to the wMel Wolbachia strain. Here we show ZIKV inhibition by two different Wolbachia strains: wAlbB (isolated from Aedes albopictus mosquitoes) and wStri (isolated from the planthopper Laodelphax striatellus) in mosquito cells. Wolbachia strain wStri inhibited ZIKV most effectively. Single-cycle infection experiments showed that ZIKV RNA replication and nonstructural protein 5 translation were reduced below the limits of detection in wStri-containing cells, demonstrating early inhibition of virus replication. ZIKV replication was rescued when Wolbachia was inhibited with a bacteriostatic antibiotic. We observed a partial rescue of ZIKV growth when Wolbachia-infected cells were supplemented with cholesterol-lipid concentrate, suggesting competition for nutrients as one of the possible mechanisms of Wolbachia inhibition of ZIKV. Our data show that wAlbB and wStri infection causes inhibition of ZIKV, making them attractive candidates for further in vitro mechanistic and in vivo studies and future vector-centered approaches to limit ZIKV infection and spread.IMPORTANCE Zika virus (ZIKV) has swiftly spread throughout most of the Western Hemisphere. This is due in large part to its replication in and spread by a mosquito vector host. There is an urgent need for approaches that limit ZIKV replication in mosquitoes. One exciting approach for this is to use a bacterial endosymbiont called Wolbachia that can populate mosquito cells and inhibit ZIKV replication. Here we show that two different strains of Wolbachia, wAlbB and wStri, are effective at repressing ZIKV in mosquito cell lines. Repression of virus growth is through the inhibition of an early stage of infection and requires actively replicating Wolbachia Our findings further the understanding of Wolbachia viral inhibition and provide novel tools that can be used in an effort to limit ZIKV replication in the mosquito vector, thereby interrupting the transmission and spread of the virus.}, }
@article {pmid28445780, year = {2017}, author = {Kim, HJ and Maiti, P and Barrientos, A}, title = {Mitochondrial ribosomes in cancer.}, journal = {Seminars in cancer biology}, volume = {47}, number = {}, pages = {67-81}, pmid = {28445780}, issn = {1096-3650}, support = {R01 GM071775/GM/NIGMS NIH HHS/United States ; R01 GM105781/GM/NIGMS NIH HHS/United States ; R01 GM112179/GM/NIGMS NIH HHS/United States ; R35 GM118141/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Apoptosis ; Biomarkers ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; Mitochondria/drug effects/genetics/*metabolism ; Mitochondrial Ribosomes/*metabolism ; Molecular Targeted Therapy ; Neoplasms/drug therapy/genetics/*metabolism ; Oxidative Phosphorylation ; Protein Biosynthesis/drug effects ; Ribosomal Proteins/metabolism ; Signal Transduction/drug effects ; }, abstract = {Mitochondria play fundamental roles in the regulation of life and death of eukaryotic cells. They mediate aerobic energy conversion through the oxidative phosphorylation (OXPHOS) system, and harbor and control the intrinsic pathway of apoptosis. As a descendant of a bacterial endosymbiont, mitochondria retain a vestige of their original genome (mtDNA), and its corresponding full gene expression machinery. Proteins encoded in the mtDNA, all components of the multimeric OXPHOS enzymes, are synthesized in specialized mitochondrial ribosomes (mitoribosomes). Mitoribosomes are therefore essential in the regulation of cellular respiration. Additionally, an increasing body of literature has been reporting an alternative role for several mitochondrial ribosomal proteins as apoptosis-inducing factors. No surprisingly, the expression of genes encoding for mitoribosomal proteins, mitoribosome assembly factors and mitochondrial translation factors is modified in numerous cancers, a trait that has been linked to tumorigenesis and metastasis. In this article, we will review the current knowledge regarding the dual function of mitoribosome components in protein synthesis and apoptosis and their association with cancer susceptibility and development. We will also highlight recent developments in targeting mitochondrial ribosomes for the treatment of cancer.}, }
@article {pmid28441108, year = {2017}, author = {Burroughs, AM and Kaur, G and Zhang, D and Aravind, L}, title = {Novel clades of the HU/IHF superfamily point to unexpected roles in the eukaryotic centrosome, chromosome partitioning, and biologic conflicts.}, journal = {Cell cycle (Georgetown, Tex.)}, volume = {16}, number = {11}, pages = {1093-1103}, pmid = {28441108}, issn = {1551-4005}, mesh = {Amino Acid Sequence ; Bacterial Proteins/chemistry/*metabolism ; Cell Membrane/metabolism ; Centrosome/*metabolism ; Chromosomes/*metabolism ; Entropy ; Eukaryota/*metabolism ; *Multigene Family ; *Phylogeny ; Protein Domains ; Protein Transport ; }, abstract = {The HU superfamily of proteins, with a unique DNA-binding mode, has been extensively studied as the primary chromosome-packaging protein of the bacterial superkingdom. Representatives also play a role in DNA-structuring during recombination events and in eukaryotic organellar genome maintenance. However, beyond these well-studied roles, little is understood of the functional diversification of this large superfamily. Using sensitive sequence and structure analysis methods we identify multiple novel clades of the HU superfamily. We present evidence that a novel eukaryotic clade prototyped by the human CCDC81 protein acquired roles beyond DNA-binding, likely in protein-protein interaction in centrosome organization and as a potential cargo-binding protein in conjunction with Dynein-VII. We also show that these eukaryotic versions were acquired via an early lateral transfer from bacteroidetes, where we predict a role in chromosome partition. This likely happened before the last eukaryotic common ancestor, pointing to potential endosymbiont contributions beyond that of the mitochondrial progenitor. Further, we show that the dramatic lineage-specific expansion of this domain in the bacteroidetes lineage primarily is linked to a functional shift related to potential recognition and preemption of genome invasive entities such as mobile elements. Remarkably, the CCDC81 clade has undergone a similar massive lineage-specific expansion within the archosaurian lineage in birds, suggesting a possible use of the HU superfamily in a similar capacity in recognition of non-self molecules even in this case.}, }
@article {pmid28439127, year = {2017}, author = {Becking, T and Giraud, I and Raimond, M and Moumen, B and Chandler, C and Cordaux, R and Gilbert, C}, title = {Diversity and evolution of sex determination systems in terrestrial isopods.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {1084}, pmid = {28439127}, issn = {2045-2322}, mesh = {Animals ; *Evolution, Molecular ; Gene Expression Profiling ; *Genetic Variation ; Isopoda/classification/*genetics ; Phylogeny ; *Sex Characteristics ; }, abstract = {Sex determination systems are highly variable in many taxa, sometimes even between closely related species. Yet the number and direction of transitions between these systems have seldom been characterized, and the underlying mechanisms are still poorly understood. Here we generated transcriptomes for 19 species of terrestrial isopod crustaceans, many of which are infected by Wolbachia bacterial endosymbionts. Using 88 single-copy orthologous genes, we reconstructed a fully resolved and dated phylogeny of terrestrial isopods. An original approach involving crossings of sex-reversed individuals allowed us to characterize the heterogametic systems of five species (one XY/XX and four ZW/ZZ). Mapping of these and previously known heterogametic systems onto the terrestrial isopod phylogeny revealed between 3 and 13 transitions of sex determination systems during the evolution of these taxa, most frequently from female to male heterogamety. Our results support that WW individuals are viable in many species, suggesting sex chromosomes are at an incipient stage of their evolution. Together, these data are consistent with the hypothesis that nucleo-cytoplasmic conflicts generated by Wolbachia endosymbionts triggered recurrent turnovers of sex determination systems in terrestrial isopods. They further establish terrestrial isopods as a model to study evolutionary transitions in sex determination systems and pave the way to molecularly characterize these systems.}, }
@article {pmid28438996, year = {2017}, author = {Montiel, J and Downie, JA and Farkas, A and Bihari, P and Herczeg, R and Bálint, B and Mergaert, P and Kereszt, A and Kondorosi, &#xc9;}, title = {Morphotype of bacteroids in different legumes correlates with the number and type of symbiotic NCR peptides.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {19}, pages = {5041-5046}, pmid = {28438996}, issn = {1091-6490}, mesh = {Bacterial Proteins/genetics/*metabolism ; Medicago truncatula/*microbiology ; Peptides/genetics/*metabolism ; Rhizobiaceae/genetics/*metabolism ; Rhizome/*microbiology ; Symbiosis/*physiology ; }, abstract = {In legume nodules, rhizobia differentiate into nitrogen-fixing forms called bacteroids, which are enclosed by a plant membrane in an organelle-like structure called the symbiosome. In the Inverted Repeat-Lacking Clade (IRLC) of legumes, this differentiation is terminal due to irreversible loss of cell division ability and is associated with genome amplification and different morphologies of the bacteroids that can be swollen, elongated, spherical, and elongated-branched, depending on the host plant. In Medicago truncatula, this process is orchestrated by nodule-specific cysteine-rich peptides (NCRs) delivered into developing bacteroids. Here, we identified the predicted NCR proteins in 10 legumes representing different subclades of the IRLC with distinct bacteroid morphotypes. Analysis of their expression and predicted sequences establishes correlations between the composition of the NCR family and the morphotypes of bacteroids. Although NCRs have a single origin, their evolution has followed different routes in individual lineages, and enrichment and diversification of cationic peptides has resulted in the ability to impose major morphological changes on the endosymbionts. The wide range of effects provoked by NCRs such as cell enlargement, membrane alterations and permeabilization, and biofilm and vesicle formation is dependent on the amino acid composition and charge of the peptides. These effects are strongly influenced by the rhizobial surface polysaccharides that affect NCR-induced differentiation and survival of rhizobia in nodule cells.}, }
@article {pmid28437427, year = {2017}, author = {Zheng, Z and Wang, D and He, H and Wei, C}, title = {Bacterial diversity of bacteriomes and organs of reproductive, digestive and excretory systems in two cicada species (Hemiptera: Cicadidae).}, journal = {PloS one}, volume = {12}, number = {4}, pages = {e0175903}, pmid = {28437427}, issn = {1932-6203}, mesh = {Alphaproteobacteria/*isolation &amp; purification ; Animals ; Evolution, Molecular ; Female ; Gastrointestinal Tract/*microbiology ; Hemiptera/*microbiology ; Male ; Ovary/*microbiology ; Phylogeny ; *Symbiosis ; Testis/*microbiology ; }, abstract = {Cicadas form intimate symbioses with bacteria to obtain nutrients that are scarce in the xylem fluid they feed on. The obligate symbionts in cicadas are purportedly confined to specialized bacteriomes, but knowledge of bacterial communities associated with cicadas is limited. Bacterial communities in the bacteriomes and organs of reproductive, digestive and excretory systems of two cicada species (Platypleura kaempferi and Meimuna mongolica) were investigated using different methods, and the bacterial diversity and distribution patterns of dominant bacteria in different tissues were compared. Within each species, the bacterial communities of testes are significantly different from those of bacteriomes and ovaries. The dominant endosymbiont Candidatus Sulcia muelleri is found not only in the bacteriomes and reproductive organs, but also in the "filter chamber + conical segment" of both species. The transmission mode of this endosymbiont in the alimentary canal and its effect on physiological processes merits further study. A novel bacterium of Rhizobiales, showing ~80% similarity to Candidatus Hodgkinia cicadicola, is dominant in the bacteriomes and ovaries of P. kaempferi. Given that the genome of H. cicadicola exhibits rapid sequence evolution, it is possible that this novel bacterium is a related endosymbiont with beneficial trophic functions similar to that of H. cicadicola in some other cicadas. Failure to detect H. cicadicola in M. mongolica suggests that it has been subsequently replaced by another bacterium, a yeast or gut microbiota which compensates for the loss of H. cicadicola. The distribution of this novel Rhizobiales species in other cicadas and its identification require further investigation to help establish the definition of the bacterial genus Candidatus Hodgkinia and to provide more information on sequence divergence of related endosymbionts of cicadas. Our results highlight the complex bacterial communities of cicadas, and are informative for further studies of the interactions and co-evolution of insect-microbial symbioses in Cicadoidea.}, }
@article {pmid28431082, year = {2017}, author = {Ayayee, PA and Keeney, G and Sabree, ZL and Muñoz-Garcia, A}, title = {Compositional differences among female-associated and embryo-associated microbiota of the viviparous Pacific Beetle cockroach, Diploptera punctata.}, journal = {FEMS microbiology ecology}, volume = {93}, number = {6}, pages = {}, doi = {10.1093/femsec/fix052}, pmid = {28431082}, issn = {1574-6941}, mesh = {Animals ; Bacterial Infections/*transmission ; Bacteroidetes/*genetics/isolation &amp; purification ; Cockroaches/*microbiology ; Female ; Gastrointestinal Microbiome/*genetics ; Halomonadaceae/genetics/isolation &amp; purification ; High-Throughput Nucleotide Sequencing ; RNA, Ribosomal, 16S/genetics ; Shewanella/genetics/isolation &amp; purification ; }, abstract = {All cockroach species, except one, harbor the endosymbiont Blattabacterium, transmitted from females to embryos. Adult cockroaches acquire non-Blattabacterium bacteria as part of their gut microbiota over time, but our knowledge of the possible transmission of these non-Blattabacterium bacteria from females to embryos is rudimentary. We characterized the gut microbiota of gravid viviparous Diploptera punctata females and the non-Blattabacterium microbiota of associated developing embryos, as well as the gut microbiota of non-gravid females, and the microbiota of orphan embryos (females not included), following high-throughput sequencing of the 16S rRNA gene to assess bacterial transference. We determined significant differences in community composition between gravid females and associated embryos and overall greater similarity in community composition among embryos than adult females. Results suggest various routes of transference of bacteria from females or the environment to embryos. The bacterial families Halomonadaceae and Shewanellaceae were more abundant in embryos than in gravid females. The functional relevance of these families remains to be elucidated, but provisioning of amino acids deficient in the brood sac secretion is a possibility. Overall, our results highlight the need for further studies investigating the uptake and selective screening of microbes by D. punctata embryos, as well as their functions.}, }
@article {pmid28429489, year = {2017}, author = {Sánchez-Arreguin, JA and Hernandez-Oñate, MA and León-Ramirez, CG and Ruiz-Herrera, J}, title = {Transcriptional analysis of the adaptation of Ustilago maydis during growth under nitrogen fixation conditions.}, journal = {Journal of basic microbiology}, volume = {57}, number = {7}, pages = {597-604}, doi = {10.1002/jobm.201600660}, pmid = {28429489}, issn = {1521-4028}, mesh = {Actins/genetics ; Adaptation, Physiological/*genetics ; Down-Regulation ; *Gene Expression Profiling ; Gene Expression Regulation, Fungal ; High-Throughput Nucleotide Sequencing ; Nitrates/pharmacology ; Nitrogen/metabolism ; *Nitrogen Fixation ; Peroxisomes/genetics ; Secondary Metabolism/genetics ; Ustilago/drug effects/*genetics/growth &amp; development/metabolism ; }, abstract = {Regulation of genes involved in nitrogen metabolism likely plays a role in the ability of fungi to exploit and survive under different environmental situations. To learn about the mechanism of adaptation of the biotrophic fungus Ustilago maydis from a medium containing a source of fixed nitrogen, to a medium depending on the ability to fix N2 by its bacterial endosymbiont, we explored gene expression profiles using RNA-Seq analyses under these two conditions. The differentially expressed (DE) fungal genes were analyzed, identifying 90 genes that were regulated 24 h after shifting the fungus to media lacking ammonium nitrate as a nitrogen source. From these, mRNA levels were increased for 49 genes, whereas 41 were down-regulated. The functional description associated to the regulated genes revealed that nine key pathways were represented, including, secondary metabolism, the metabolism of nitrogen, amino acid, fatty acid, amino sugar and nucleotide sugar, purine, peroxisome, and the regulation of actin cytoskeleton. These results suggest that the interplay of U. maydis with its N2 fixing bacterial endosymbiont is a flexible process that may be active during the adaptation of the fungus to the different nitrogen sources.}, }
@article {pmid28429323, year = {2017}, author = {Durnford, DG and Schwartzbach, SD}, title = {Protein Targeting to the Plastid of Euglena.}, journal = {Advances in experimental medicine and biology}, volume = {979}, number = {}, pages = {183-205}, doi = {10.1007/978-3-319-54910-1_10}, pmid = {28429323}, issn = {0065-2598}, mesh = {Euglena/*physiology/ultrastructure ; Golgi Apparatus/*physiology/ultrastructure ; Intracellular Membranes/*physiology/ultrastructure ; Protein Transport/physiology ; Protozoan Proteins/genetics/*metabolism ; Thylakoids/*physiology/ultrastructure ; }, abstract = {The lateral transfer of photosynthesis between kingdoms through endosymbiosis is among the most spectacular examples of evolutionary innovation. Euglena, which acquired a chloroplast indirectly through an endosymbiosis with a green alga, represents such an example. As with other endosymbiont-derived plastids from eukaryotes, there are additional membranes that surround the organelle, of which Euglena has three. Thus, photosynthetic genes that were transferred from the endosymbiont to the host nucleus and whose proteins are required in the new plastid, are now faced with targeting and plastid import challenges. Early immunoelectron microscopy data suggested that the light-harvesting complexes, photosynthetic proteins in the thylakoid membrane, are post-translationally targeted to the plastid via the Golgi apparatus, an unexpected discovery at the time. Proteins targeted to the Euglena plastid have complex, bipartite presequences that direct them into the endomembrane system, through the Golgi apparatus and ultimately on to the plastid, presumably via transport vesicles. From transcriptome sequencing, dozens of plastid-targeted proteins were identified, leading to the identification of two different presequence structures. Both have an amino terminal signal peptide followed by a transit peptide for plastid import, but only one of the two classes of presequences has a third domain-the stop transfer sequence. This discovery implied two different transport mechanisms; one where the protein was fully inserted into the lumen of the ER and another where the protein remains attached to, but effectively outside, the endomembrane system. In this review, we will discuss the biochemical and bioinformatic evidence for plastid targeting, discuss the evolution of the targeting system, and ultimately provide a working model for the targeting and import of proteins into the plastid of Euglena.}, }
@article {pmid28426794, year = {2017}, author = {Monnin, D and Kremer, N and Desouhant, E and Vavre, F}, title = {Impact of Wolbachia on oxidative stress sensitivity in the parasitic wasp Asobara japonica.}, journal = {PloS one}, volume = {12}, number = {4}, pages = {e0175974}, pmid = {28426794}, issn = {1932-6203}, mesh = {Animals ; Host-Pathogen Interactions ; *Oxidative Stress ; Symbiosis ; Wasps/*microbiology ; Wolbachia/*physiology ; }, abstract = {The oxidative homeostasis is the balance between reactive oxygen species and antioxidant molecules. In addition to be considered as a key factor underlying life-history traits evolution, the oxidative homeostasis has been shown to be involved in many host-symbiont associations. Previous studies suggest an interaction between the bacterial endosymbiont Wolbachia and the oxidative homeostasis of some insect hosts. This interaction is likely to exert a strong influence on the host evolution, as it has been proposed in the wasp Asobara tabida, whose dependence upon Wolbachia is due to the evolutionary loss of its ability to regulate the oxidative homeostasis in the absence of the symbiont. Although such cases of complete dependence are rare, cases of insects having lost only a part of their autonomy over the control of the oxidative homeostasis might be more common. If so, one can expect that insects having coevolved with Wolbachia will be more sensitive to oxidative stress when cured of their symbionts. We tested this hypothesis by studying the effects of an experimentally-induced oxidative stress on various life-history traits of Asobara japonica, a species closely related to A. tabida. For most of the life-history traits studied, the sensitivity of the wasps to oxidative stress did not correlate with their infection status. The only exception was the parasitic success. However, contrarily to our expectation, the sensitivity to oxidative stress was increased, rather than decreased, when Wolbachia was present. This result suggests that Wolbachia does not participate to mitigate oxidative stress in A. japonica, and that on the contrary its presence might still be costly in stressful environments.}, }
@article {pmid28419279, year = {2017}, author = {Boyd, BM and Allen, JM and Nguyen, NP and Vachaspati, P and Quicksall, ZS and Warnow, T and Mugisha, L and Johnson, KP and Reed, DL}, title = {Primates, Lice and Bacteria: Speciation and Genome Evolution in the Symbionts of Hominid Lice.}, journal = {Molecular biology and evolution}, volume = {34}, number = {7}, pages = {1743-1757}, pmid = {28419279}, issn = {1537-1719}, mesh = {Animals ; Anoplura/*genetics ; Bacteria/genetics ; Biological Evolution ; Evolution, Molecular ; Genome, Bacterial ; Genomics/methods ; Hominidae/genetics ; Humans ; Pan troglodytes/genetics ; Pediculus/*genetics ; Phylogeny ; Plasmids/genetics ; Primates/genetics ; Sequence Analysis, DNA/methods ; Symbiosis/*genetics ; }, abstract = {Insects with restricted diets rely on symbiotic bacteria to provide essential metabolites missing in their diet. The blood-sucking lice are obligate, host-specific parasites of mammals and are themselves host to symbiotic bacteria. In human lice, these bacterial symbionts supply the lice with B-vitamins. Here, we sequenced the genomes of symbiotic and heritable bacterial of human, chimpanzee, gorilla, and monkey lice and used phylogenomics to investigate their evolutionary relationships. We find that these symbionts have a phylogenetic history reflecting the louse phylogeny, a finding contrary to previous reports of symbiont replacement. Examination of the highly reduced symbiont genomes (0.53-0.57 Mb) reveals much of the genomes are dedicated to vitamin synthesis. This is unchanged in the smallest symbiont genome and one that appears to have been reorganized. Specifically, symbionts from human lice, chimpanzee lice, and gorilla lice carry a small plasmid that encodes synthesis of vitamin B5, a vitamin critical to the bacteria-louse symbiosis. This plasmid is absent in an old world monkey louse symbiont, where this pathway is on its primary chromosome. This suggests the unique genomic configuration brought about by the plasmid is not essential for symbiosis, but once obtained, it has persisted for up to 25 My. We also find evidence that human, chimpanzee, and gorilla louse endosymbionts have lost a pathway for synthesis of vitamin B1, whereas the monkey louse symbiont has retained this pathway. It is unclear whether these changes are adaptive, but they may point to evolutionary responses of louse symbionts to shifts in primate biology.}, }
@article {pmid28416684, year = {2017}, author = {Distel, DL and Altamia, MA and Lin, Z and Shipway, JR and Han, A and Forteza, I and Antemano, R and Limbaco, MGJP and Tebo, AG and Dechavez, R and Albano, J and Rosenberg, G and Concepcion, GP and Schmidt, EW and Haygood, MG}, title = {Discovery of chemoautotrophic symbiosis in the giant shipworm Kuphus polythalamia (Bivalvia: Teredinidae) extends wooden-steps theory.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {114}, number = {18}, pages = {E3652-E3658}, pmid = {28416684}, issn = {1091-6490}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*metabolism ; Bivalvia/*microbiology ; Chemoautotrophic Growth/*physiology ; Symbiosis/*physiology ; Wood/*metabolism/microbiology ; }, abstract = {The "wooden-steps" hypothesis [Distel DL, et al. (2000) Nature 403:725-726] proposed that large chemosynthetic mussels found at deep-sea hydrothermal vents descend from much smaller species associated with sunken wood and other organic deposits, and that the endosymbionts of these progenitors made use of hydrogen sulfide from biogenic sources (e.g., decaying wood) rather than from vent fluids. Here, we show that wood has served not only as a stepping stone between habitats but also as a bridge between heterotrophic and chemoautotrophic symbiosis for the giant mud-boring bivalve Kuphus polythalamia This rare and enigmatic species, which achieves the greatest length of any extant bivalve, is the only described member of the wood-boring bivalve family Teredinidae (shipworms) that burrows in marine sediments rather than wood. We show that K. polythalamia harbors sulfur-oxidizing chemoautotrophic (thioautotrophic) bacteria instead of the cellulolytic symbionts that allow other shipworm species to consume wood as food. The characteristics of its symbionts, its phylogenetic position within Teredinidae, the reduction of its digestive system by comparison with other family members, and the loss of morphological features associated with wood digestion indicate that K. polythalamia is a chemoautotrophic bivalve descended from wood-feeding (xylotrophic) ancestors. This is an example in which a chemoautotrophic endosymbiosis arose by displacement of an ancestral heterotrophic symbiosis and a report of pure culture of a thioautotrophic endosymbiont.}, }
@article {pmid28414941, year = {2017}, author = {Syed, B and M N, NP and K, MK and B L, D and Satish, S}, title = {Endo-symbiont mediated synthesis of gold nanobactericides and their activity against human pathogenic bacteria.}, journal = {Environmental toxicology and pharmacology}, volume = {52}, number = {}, pages = {143-149}, doi = {10.1016/j.etap.2017.03.016}, pmid = {28414941}, issn = {1872-7077}, mesh = {*Anti-Bacterial Agents/biosynthesis/pharmacology ; Bacillales/*metabolism ; Bacteria/drug effects/growth &amp; development ; DNA Damage ; *Gold/metabolism/pharmacology ; *Metal Nanoparticles ; }, abstract = {Synthesis of gold nanobactericides (AuNBs) were achieved by treating 1mM chloroaurate with cell free supernatant of Aneurinibacillus migulanus. Formation of AuNBs was initially was monitored with change in colour to ruby red. Further confirmation was assessed with UV-visible spectra with maximum absorption occurring at 510nm. Transmission electron microscopy (TEM) analysis revealed the polydispersity of AuNBs with size distribution ranging from 10 to 60nm with an average size of 30nm. Crystalline nature was studied using X-ray diffraction which exhibited characteristic peaks indexed to Bragg's reflection at 2θ angle which confers (111), (200), (220), and (311) planes suggesting AuNBs were face-centred cubic. Fourier transform infrared spectroscopy (FTIR) analysis revealed absorption peaks occurring at 3341cm[-1], 1635cm[-1] and 670cm[-1] which corresponds to functional groups attributing to synthesis. The antibacterial efficacy of AuNBs was tested against selective human pathogenic bacteria and activity was measured as zone of inhibition by using disc and well diffusion. Bactericidal activity was interpreted with standard antibiotics gentamicin and kanamycin. Micro broth dilution assay expressed the minimal concentration of AuNBs to inhibit the growth of test pathogens. Highest activity was observed against Pseudomonas aeruginosa (MTCC 7903) with 21.00±0.57mm compared to other pathogens. The possible mode of action of AuNBs on DNA was carried out with in vitro assay as preliminary test against pathogenic DNA isolated from P. aeruginosa. Further studies will be interesting enough to reveal the exact interactive mechanism of AuNBs with DNA. Overall study contributes towards biogenic synthesis of AuNBs as one of the alternative in combating drug resistant pathogens.}, }
@article {pmid28412513, year = {2017}, author = {Ju, JF and Hoffmann, AA and Zhang, YK and Duan, XZ and Guo, Y and Gong, JT and Zhu, WC and Hong, XY}, title = {Wolbachia-induced loss of male fertility is likely related to branch chain amino acid biosynthesis and iLvE in Laodelphax striatellus.}, journal = {Insect biochemistry and molecular biology}, volume = {85}, number = {}, pages = {11-20}, doi = {10.1016/j.ibmb.2017.04.002}, pmid = {28412513}, issn = {1879-0240}, mesh = {Amino Acids/*biosynthesis ; Animals ; Copulation ; Female ; Fertility ; Hemiptera/metabolism/*microbiology ; *Host-Pathogen Interactions ; Insect Proteins/metabolism ; Male ; Oligonucleotide Array Sequence Analysis ; Testis/metabolism ; Transcriptome ; Wolbachia/*physiology ; }, abstract = {Wolbachia are endosymbionts that infect many species of arthropods and nematodes. Wolbachia-induced cytoplasmic incompatibility (CI) is the most common phenotype in affected hosts, involving embryonic lethality in crosses between Wolbachia-infected males and uninfected females. The molecular mechanisms underlying this phenomenon are currently unclear. Here we examine the molecular correlates of the Wolbachia infection in Laodelphax striatellus (Fallén), an important rice pest, where embryonic lethality is strong and almost complete. We compared the gene expression of 4-day-old Wolbachia-infected and uninfected L. striatellus testes to identify candidate genes for paternal-effect embryonic lethality induction. Based on microarray analysis, iLvE was the most down-regulated gene; this gene mediates branched-chain amino acid (BCAA) biosynthesis and participates in many processes related to reproductive performance. After knocking down iLvE by RNAi in uninfected male L. striatellus, male fertility was reduced, leading to a decrease in embryo hatching rates, but fertility was rescued in crosses between these males and Wolbachia-infected females. Removal of BCAA in chemically-defined diets of uninfected males also led to a loss of male fertility. Low amino acid nutrition may enhance exposure time of sperm to Wolbachia in the testes to affect adult reproduction in L. striatellus by reducing the number of sperm transferred per mating by males. These results indicate that Wolbachia may decrease male fertility in L. striatellus by acting on iLvE, a key factor of BCAA biosynthesis, and delaying sperm maturation.}, }
@article {pmid28410570, year = {2017}, author = {Valadez-Cano, C and Olivares-Hernández, R and Resendis-Antonio, O and DeLuna, A and Delaye, L}, title = {Natural selection drove metabolic specialization of the chromatophore in Paulinella chromatophora.}, journal = {BMC evolutionary biology}, volume = {17}, number = {1}, pages = {99}, pmid = {28410570}, issn = {1471-2148}, mesh = {Biological Evolution ; Cercozoa/*cytology/genetics/*physiology ; Computer Simulation ; Cyanobacteria/genetics/*physiology ; Hexoses/metabolism ; Selection, Genetic ; Symbiosis ; Synechococcus/cytology/metabolism ; }, abstract = {BACKGROUND: Genome degradation of host-restricted mutualistic endosymbionts has been attributed to inactivating mutations and genetic drift while genes coding for host-relevant functions are conserved by purifying selection. Unlike their free-living relatives, the metabolism of mutualistic endosymbionts and endosymbiont-originated organelles is specialized in the production of metabolites which are released to the host. This specialization suggests that natural selection crafted these metabolic adaptations. In this work, we analyzed the evolution of the metabolism of the chromatophore of Paulinella chromatophora by in silico modeling. We asked whether genome reduction is driven by metabolic engineering strategies resulted from the interaction with the host. As its widely known, the loss of enzyme coding genes leads to metabolic network restructuring sometimes improving the production rates. In this case, the production rate of reduced-carbon in the metabolism of the chromatophore.<br><br>RESULTS: We reconstructed the metabolic networks of the chromatophore of P. chromatophora CCAC 0185 and a close free-living relative, the cyanobacterium Synechococcus sp. WH 5701. We found that the evolution of free-living to host-restricted lifestyle rendered a fragile metabolic network where >80% of genes in the chromatophore are essential for metabolic functionality. Despite the lack of experimental information, the metabolic reconstruction of the chromatophore suggests that the host provides several metabolites to the endosymbiont. By using these metabolites as intracellular conditions, in silico simulations of genome evolution by gene lose recover with 77% accuracy the actual metabolic gene content of the chromatophore. Also, the metabolic model of the chromatophore allowed us to predict by flux balance analysis a maximum rate of reduced-carbon released by the endosymbiont to the host. By inspecting the central metabolism of the chromatophore and the free-living cyanobacteria we found that by improvements in the gluconeogenic pathway the metabolism of the endosymbiont uses more efficiently the carbon source for reduced-carbon production. In addition, our in silico simulations of the evolutionary process leading to the reduced metabolic network of the chromatophore showed that the predicted rate of released reduced-carbon is obtained in less than 5% of the times under a process guided by random gene deletion and genetic drift. We interpret previous findings as evidence that natural selection at holobiont level shaped the rate at which reduced-carbon is exported to the host. Finally, our model also predicts that the ABC phosphate transporter (pstSACB) which is conserved in the genome of the chromatophore of P. chromatophora strain CCAC 0185 is a necessary component to release reduced-carbon molecules to the host.<br><br>CONCLUSION: Our evolutionary analysis suggests that in the case of Paulinella chromatophora natural selection at the holobiont level played a prominent role in shaping the metabolic specialization of the chromatophore. We propose that natural selection acted as a "metabolic engineer" by favoring metabolic restructurings that led to an increased release of reduced-carbon to the host.}, }
@article {pmid28408315, year = {2017}, author = {Allen, JF}, title = {The CoRR hypothesis for genes in organelles.}, journal = {Journal of theoretical biology}, volume = {434}, number = {}, pages = {50-57}, doi = {10.1016/j.jtbi.2017.04.008}, pmid = {28408315}, issn = {1095-8541}, mesh = {*Cell Compartmentation ; Enzymes/genetics ; Organelles/*genetics ; Oxidation-Reduction ; Prokaryotic Cells/*metabolism/ultrastructure ; Symbiosis ; }, abstract = {Chloroplasts and mitochondria perform energy transduction in photosynthesis and respiration. These processes can be described in physico-chemical terms with no obvious requirement for co-located genetic systems, separat from those of the rest of the cell. Accordingly, biochemists once tended to regard endosymbiosis as untestable evolutionary speculation. Lynn Sagan's seminal 1967 paper "On the Origin of Mitosing Cells" outlined the evolution of eukaryotic cells by endosymbiosis of prokaryotes. The endosymbiont hypothesis is consistent with presence of DNA in chloroplasts and mitochondria, but does not assign it a function. Biochemistry and molecular biology now show that Sagan's proposal has an explanatory reach far beyond that originally envisaged. Prokaryotic origins of photosynthetic and respiratory mechanisms are apparent in protein structural insights into energy coupling. Genome sequencing confirms the underlying, prokaryotic architecture of chloroplasts and mitochondria and illustrates the profound influence of the original mergers of their ancestors' genes and proteins with those of their host cells. Peter Mitchell's 1961 chemiosmotic hypothesis applied the concept of vectorial catalysis that underlies biological energy transduction and cell structure, function, and origins. Continuity of electrical charge separation and membrane sidedness requires compartments within compartments, together with intricate mechanisms for transport within and between them. I suggest that the reason for the persistence of distinct genetic systems within bioenergetic organelles is the selective advantage of subcellular co-location of specific genes with their gene products. Co-location for Redox Regulation - CoRR - provides for a dialogue between chemical reduction-oxidation and the action of genes encoding its protein catalysts. These genes and their protein products are in intimate contact, and cannot be isolated from each other without loss of an essential mechanism of adaptation of electron transport to change in the external environment.}, }
@article {pmid28405268, year = {2017}, author = {Ma, Y and Chen, WJ and Li, ZH and Zhang, F and Gao, Y and Luan, YX}, title = {Revisiting the phylogeny of Wolbachia in Collembola.}, journal = {Ecology and evolution}, volume = {7}, number = {7}, pages = {2009-2017}, pmid = {28405268}, issn = {2045-7758}, abstract = {The endosymbiont Wolbachia has been detected in a few parthenogenetic collembolans sampled in Europe and America, including three species of Poduromorpha, two species of Entomobryomorpha, and two species of Neelipleona. Based on 16S rRNA and ftsZ gene sequences, most of the Wolbachia infecting parthenogenetic collembolans were characterized as members of supergroup E and showed concordant phylogeny with their hosts. However, the two neelipleonan symbionts form another unique group, indicating that Wolbachia has infected parthenogenetic collembolans multiple times. In this study, five parthenogenetic collembolan species were identified as hosts of Wolbachia, and four new Wolbachia strains were reported for four collembolan species sampled in China, respectively, including a neelipleonan strain from Megalothorax incertus (wMinc). Our results demonstrated that the Wolbachia multilocus sequence typing (MLST) system is superior to the 16S rRNA + ftsZ approach for phylogenetic analyses of collembolan Wolbachia. The MLST system assigned these Wolbachia of parthenogenetic collembolans to supergroup E as a unique clade, which included wMinc, supporting the monophyletic origin of Wolbachia in parthenogenetic collembolan species. Moreover, our data suggested supergroup E as one of the most divergent lineages in Wolbachia and revealed the discrepancy between the phylogenies of Wolbachia from parthenogenetic collembolans and their hosts, which may result from the high level of genetic divergence between collembolan Wolbachia, in association with the geographic differentiation of their hosts, or the possible horizontal transmission of Wolbachia between different collembolan species.}, }
@article {pmid28405008, year = {2017}, author = {Dunning Hotopp, JC and Slatko, BE and Foster, JM}, title = {Targeted Enrichment and Sequencing of Recent Endosymbiont-Host Lateral Gene Transfers.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {857}, pmid = {28405008}, issn = {2045-2322}, support = {DP2 OD007372/OD/NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Genome, Helminth ; Nematoda/genetics/microbiology ; *Symbiosis ; Wolbachia/genetics/pathogenicity ; }, abstract = {Lateral gene transfer (LGT) from microbial symbionts to invertebrate animals is described at an increasing rate, particularly between Wolbachia endosymbionts and their diverse invertebrate hosts. We sought to assess the use of a capture system to cost-effectively sequence such LGT from the host genome. The sequencing depth of Illumina paired end data obtained with a Wolbachia capture system correlated well with that for an Illumina paired end data set used to detect LGT in Wolbachia-depleted B. malayi (p-value: <2e-16). Using a sequencing depth threshold of two or three standard deviations above the mean, 96.9% or 96.7% of positions, respectively, are predicted in the same manner between the two datasets, with 24.7% or 42.5% of the known 49.0 kbp of LGT sequence predicted correctly, respectively. Prior qPCR results for nuwts showed similar correlations for both datasets supporting our conclusion that oligonucleotide-based capture methods can be used to obtain sequences from Wolbachia-host LGT. However, at least 121 positions had a minority of the reads supporting the endosymbiont reference base call using the capture data, illustrating that sequence reads from endosymbiont-host LGTs can confound endosymbiont genome projects, erroneously altering the called consensus genome, a problem that is irrespective to the sequencing technology or platform.}, }
@article {pmid28402703, year = {2017}, author = {Ghoneim, NH and Abdel-Moein, KA and Zaher, HM}, title = {Molecular Detection of Francisella spp. Among Ticks Attached to Camels in Egypt.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {17}, number = {6}, pages = {384-387}, doi = {10.1089/vbz.2016.2100}, pmid = {28402703}, issn = {1557-7759}, mesh = {Animals ; Camelus/*parasitology ; Egypt/epidemiology ; Francisella/*isolation &amp; purification ; Ixodidae/*microbiology ; Phylogeny ; RNA, Bacterial/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Tick Infestations/epidemiology/*veterinary ; }, abstract = {This study was conducted to investigate the possible role of camels and attached ticks in the epidemiology of Francisella spp. including Francisella tularensis. For this purpose, a total of 319 ticks (248 Hyalomma dromedarii and 71 Amblyomma spp.) as well as 100 blood and 50 fecal samples collected from camels were screened for the presence of Francisella spp. by PCR through amplification of Francisella 16S rRNA gene. Positive samples were then tested for F. tularensis by PCR. In addition, serum samples from 75 camel abattoir workers were examined for the presence of IgG antibodies against F. tularensis using enzyme-linked immunosorbent assay (ELISA). Of the examined ticks, 15 were positive for Francisella spp. with prevalence of 4.7%, all positive results were recorded in Hyalomma dromedarii (6%). Neither blood nor fecal samples from camels yielded Francisella spp. even camels which carried Francisella spp. positive ticks. Moreover, F. tularensis could not be detected among Francisella-positive ticks. Phylogenetic analysis of some Francisella 16S rRNA gene sequences obtained in this study points out that these sequences are closely related to Francisella-like endosymbionts. In contrast, seroprevalence of F. tularensis antibodies among examined abattoir workers was 9.3% with significantly high prevalence among workers frequently exposed to tick bites (20.7%) rather than occasionally exposed workers (2.2%). In conclusion, however, F. tularensis could not be detected in this study; the high seroprevalence among camel abattoir workers especially those frequently exposed to tick bites underlines the possible role of ticks attached to camels in transmission of tularemia to humans.}, }
@article {pmid30549849, year = {2017}, author = {Maddah, FE and Nazir, M and König, GM}, title = {The Rare Amino Acid Building Block 3-(3-furyl)-Alanine in the Formation of Non-ribosomal Peptides.}, journal = {Natural product communications}, volume = {12}, number = {1}, pages = {147-150}, pmid = {30549849}, issn = {1934-578X}, mesh = {Burkholderia/metabolism ; Peptide Synthases/*metabolism ; Peptides/*chemistry ; Rhizopus/metabolism ; }, abstract = {Microorganisms have made considerable contributions to the production of peptide secondary metabolites, many of them with therapeutic potential eg, the fungus-derived immunosuppressant cyclosporine A and the antibiotic daptomycin originating from Streptomyces. Most of the medically used peptides are the :product of non-ribosomal peptide synthetases (NRPS), incorporating apart from proteinogenic also unique, non-proteinogenic amino acids into the peptides. An extremely rare such amino acid is 3-(3-furyl)-alanine. So far, only few peptides have been found that contain this residue, including the rhizonins, bingchamide B and endolides. The producer of the rhizonins was proven to be the bacterial endosymbiont Burkholderia endofungorum inside the fungus Rhizopus microsporus. The microbial origin, chemistry and bioactivity of the 3-(3-furyl)-alanine containing peptides are the focus of this review.}, }
@article {pmid29369556, year = {2016}, author = {Afanas’ev, MV and Balakhonov, SV and Tokmakova, EG and Polovinkina, VS and Sidorova, EA and Sinkov, VV}, title = {[Analysis of complete sequence of cryptic plasmid pTP33 from Yersinia pestis isolated in Tuva natural focus of plague].}, journal = {Genetika}, volume = {52}, number = {9}, pages = {1012-1020}, pmid = {29369556}, issn = {0016-6758}, mesh = {Bacterial Proteins/*genetics ; Plague/*genetics ; Plasmids/*genetics ; Siberia ; Yersinia pestis/*genetics/isolation &amp; purification ; }, abstract = {This paper studies a full nucleotide sequence of cryptic plasmid pTP33, which was isolated from the typical plague strain of the Tuvinian natural focus, Yersinia pestis I-2638. Sequencing was carried out using the 454 GS Junior platform (Roche). In analysis using the software package GS De Novo Assembler v. 2.7 (Roche) and the algorithm Newbler v. 2.7, 1855 nucleotide reads, which contained 1101246 nucleotides, were assembled to a contig of 33 978 bp. The GC content of the obtained nucleotide sequence was 50.25%. During annotation, we found 56 open reading frames. Homologs of the predicted reading frames were sought in the BLAST databases. We detected 22 reading frames coding hypothetical proteins, 23 frames coding phagerelated proteins, and 11 frames coding proteins with known functions, including toxin–antitoxin system YefM-YoeB, nucleic acids and polysaccharides metabolism proteins (exopolysaccharide production protein ExoZ, exodeoxyribonuclease VIII), and replication proteins (ParA). Some predicted pTP33 proteins were found to be homologs (from 45 to 75%) with sequences of phage-related proteins of certain microorganisms—endosymbionts of insects (Sodalis glossinidius) and endosymbionts of entomopathogenic nematodes (Photorhabdus luminescens, P. asymbiotica, Xenorhabdus bovienii).}, }
@article {pmid31766793, year = {2008}, author = {Fabricius, KE and De'ath, G}, title = {PHOTOSYNTHETIC SYMBIONTS AND ENERGY SUPPLY DETERMINE OCTOCORAL BIODIVERSITY IN CORAL REEFS.}, journal = {Ecology}, volume = {89}, number = {11}, pages = {3163-3173}, doi = {10.1890/08-0005.1}, pmid = {31766793}, issn = {1939-9170}, abstract = {Many coral reef organisms live in symbiotic relationships with photosynthetic microalgae. This symbiosis extends the energy resources available to reef organisms, thereby potentially influencing biodiversity. In octocorals, about one-half of the taxa contain photosynthetic symbionts while the rest do not, and thus octocorals are an ideal model to assess the relationships between biodiversity, spatial and environmental factors, and photosynthetic symbionts. Data collected from 1106 sites on the Great Barrier Reef, Australia, between 12° and 24° S showed that taxa with photosynthetic symbionts (phototrophs) had higher abundances, wider ranges, and a wider spread of locations than taxa without symbionts (heterotrophs). In phototrophic assemblages, spatial turnover comprised both exchange and loss of taxa, and their richness was high across a broad range of environmental conditions. In contrast, heterotrophs were uncommon, had short ranges, and were located where energy supply was highest and disturbance lowest. Turnover between heterotrophic assemblages comprised taxonomic loss rather than exchange of taxa. The biodiversity patterns and differences between phototrophic and heterotrophic octocorals are similar to those recorded in more spatially limited studies of phototrophic sponges and hard corals, and heterotrophic sponges. This study therefore suggests that the association, or not, with photosynthetic symbionts, and spatial and environmental factors related to energy supply and disturbance are principal drivers of biodiversity, community composition, and ranges of coral reef benthos.}, }
@article {pmid29592135, year = {2000}, author = {Rispe, C and Moran, NA}, title = {Accumulation of Deleterious Mutations in Endosymbionts: Muller's Ratchet with Two Levels of Selection.}, journal = {The American naturalist}, volume = {156}, number = {4}, pages = {425-441}, doi = {10.1086/303396}, pmid = {29592135}, issn = {1537-5323}, abstract = {Many eukaryotes host mutualistic, maternally transmitted prokaryotic symbionts. Two kinds of evolution within symbiont genomes threaten to erode the benefits of these associations. First, because symbionts reproduce asexually, are sequestered within hosts, and undergo bottlenecks at infection, they are subject to the long-term accumulation of deleterious mutations through Muller's ratchet. Second, "selfish" mutations, benefiting symbionts at host expense, could cause the ultimate decline of both host and symbionts. We performed simulations to assess how the fate of each mutation type is affected by host population size, numbers of symbionts transmitted to progeny, selection within and between hosts, and mutation rate. Fixation rate always increases with decreasing host population size. However, fixation rates for uniformly deleterious and selfish mutations are oppositely affected by varying transmission numbers, with increased numbers slowing accumulation of strictly deleterious mutations, especially for effects concentrated within hosts, but speeding fixation of "selfish" mutations. In aphid symbionts, most genes underlie basic cellular processes and are probably selected at both levels, but a substantial minority of genes contribute only to host fitness. No inoculum size is optimal for minimizing deleterious evolution for both categories of gene.}, }
@article {pmid29227702, year = {1996}, author = {Lee, RW and Childress, JJ}, title = {Inorganic N Assimilation and Ammonium Pools in a Deep-Sea Mussel Containing Methanotrophic Endosymbionts.}, journal = {The Biological bulletin}, volume = {190}, number = {3}, pages = {373-384}, doi = {10.2307/1543030}, pmid = {29227702}, issn = {1939-8697}, abstract = {Undescribed mussels (seep mytilid 1a) harboring methanotrophic endosymbionts exhibit high biomass around hydrocarbon seeps on the Louisiana Slope of the Gulf of Mexico. These mussels assimilate ammonium and nitrate present at high concentrations in their environment. Pathways of assimilation were investigated by enzyme activity measurements and 15N tracer experiments. Glutamine synthetase was detected in all freshly collected mussels tested. Nitrate reductase activity was not always observed. Exposure to 15NH3 resulted in the appearance of millimolar concentrations of 15NH3 within the symbiont-containing tissues. The concentration of internal 15NH3 was several times higher than in the medium and correlated with 15NH3 assimilation rate. These results indicate that exogenous 15NH3 was taken up into a large internal pool before it was assimilated. Our results do not indicate the extent to which ammonium pools were within the host or symbiont or whether ammonium assimilation was facilitated by either partner exclusively. The observation of elevated internal ammonium concentrations is inconsistent with the "depletion-diffusion" mechanism of nutrient uptake proposed for algal-invertebrate symbioses and is suggestive of active ammonium uptake mechanisms across the host surface. Exposure to 15NO3- also resulted in the appearance of 15NH3, with internal 15NH3 concentration correlated with 15NO3- assimilation rate. This result indicates that 15NO3- was reduced more rapidly than it was assimilated and that 15NH3 derived from 15NO3- may also enter an internal ammonium pool. Assimilation of nitrate in the presence of millimolar concentrations of internal ammonium and reduction of 15NO3- in excess of assimilation is consistent with the functioning of dissimilatory nitrate reduction pathways with ammonium as a major endproduct. Such a mechanism may operate in other chemosynthetic symbioses that exhibit dissimilatory nitrate reduction.}, }
@article {pmid28564863, year = {1995}, author = {Blackstone, NW}, title = {PERSPECTIVE A UNITS-OF-EVOLUTION PERSPECTIVE ON THE ENDOSYMBIONT THEORY OF THE ORIGIN OF THE MITOCHONDRION.}, journal = {Evolution; international journal of organic evolution}, volume = {49}, number = {5}, pages = {785-796}, doi = {10.1111/j.1558-5646.1995.tb02315.x}, pmid = {28564863}, issn = {1558-5646}, abstract = {Discussions of mitochondria and their hosts often conceptualize this relationship in a more or less modern form, focusing on the metabolic benefits of mitochondria to the host cell or on the possibility of intragenomic conflict. A more inclusive units-of-evolution perspective recognizes that both costs and benefits must be viewed from the level of the cells that initiated this interaction, the protomitochondrion and the primitive host cell. From this perspective, ecological and physiological considerations become central to the characterization of initial and subsequent host-mitochondria associations. Foremost among these considerations is the generation of superoxide radicals by modern mitochondria and the deleterious effects of these endogenous oxidants on modern eukaryotic cells. Because of their photosynthetic and aerobic ecologies, protomitochondria likely were relatively tolerant of such oxidants; anaerobic, heterotrophic, primitive host cells, on the other hand, likely were not. In the initial association of host and symbiont, the latter may have manipulated the former's life history by means of both endogenous oxidants and a superabundance of ATP. A resolution of this units-of-evolution conflict was necessary to continue this association, and this resolution, in a ritualized form, may have shaped the evolution of many features of modern eukaryotic cells and mitochondria, for example, the messenger functions of calcium ions, the regulatory role of phosphorylation cascades in cell-division cycles, the absence from the mitochondrial genome of replication factors, transcription factors, and adenine nucleotide carrier genes. The initial host-mitochondria interaction may have further channeled the evolution of multicellular eukaryotes, particularly animals, resulting in the association of mitochondria and the germinal plasm and in the use of extracellular ATP and endogenous oxidants as developmental signals. Evolutionary explanations for "free-radical" theories of development and aging are thus suggested.}, }
@article {pmid28564045, year = {1991}, author = {Ebbert, MA}, title = {THE INTERACTION PHENOTYPE IN THE DROSOPHILA WILLISTONI-SPIROPLASMA SYMBIOSIS.}, journal = {Evolution; international journal of organic evolution}, volume = {45}, number = {4}, pages = {971-988}, doi = {10.1111/j.1558-5646.1991.tb04364.x}, pmid = {28564045}, issn = {1558-5646}, abstract = {Both the population and coevolutionary dynamics of hereditary male-lethal endosymbionts, found in a wide range of insect species, depend on host fitness and endosymbiont transmission rates. This paper reports on fitness effects and transmission rates in three lines of Drosophila willistoni infected with either male-lethal spiroplasmas or a spontaneous nonmale-lethal mutant. Overall fitness measures were reduced or unaffected by the infection; however, some infected females produced more offspring in early broods. Maternal transmission rates were high, but imperfect, and varied with a female's age, host line, and spiroplasma type. No evidence for paternal or horizontal transmission was found. If an altered temporal pattern of reproduction is not a factor in countering the loss of spiroplasma hosts through imperfect maternal transmission, persistence of this endoparasitism remains unexplained. Tolerance of the infection and ability to transmit bacteria varied with both host and spiroplasma line. Analysis of the interaction between the spontaneous nonmale-lethal mutant and its host suggests this symbiosis has undergone coevolution under laboratory culture.}, }
@article {pmid28568551, year = {1989}, author = {Wren, HN and Johnson, JL and Cochran, DG}, title = {EVOLUTIONARY INFERENCES FROM A COMPARISON OF COCKROACH NUCLEAR DNA AND DNA FROM THEIR FAT-BODY AND EGG ENDOSYMBIONTS.}, journal = {Evolution; international journal of organic evolution}, volume = {43}, number = {2}, pages = {276-281}, doi = {10.1111/j.1558-5646.1989.tb04227.x}, pmid = {28568551}, issn = {1558-5646}, abstract = {DNA was isolated from muscle tissue and from concentrations of the egg and fat-body endosymbionts of the cockroaches Periplaneta americana, Blatta orientalis, Blaberus giganteus, Gromphadorhina portentosa, Leucophaea maderae, Cryptocercus punctulatus, and Nyctibora lutzi. Denatured DNA from each was immobilized on nitrocellulose membranes and reassociated with labeled probe DNAs from egg endosymbionts and muscle nuclei of B. orientalis. The DNAs were compared by extent of binding and by the thermal melting profiles of the DNA duplexes. The DNAs from the endosymbionts in the eggs and fat body in both P. americana and B. orientalis were shown to be virtually identical, confirming that transovarial transmission of the bacteria does take place. The thermal stabilities of the heteroduplexes formed with the probe DNA from egg endosymbionts of B. orientalis differed from the homologous duplexes by only 1°-11°C, indicating a close relationship among the endosymbiont strains. The heteroduplexes of the nuclear DNAs differ from the homologous duplexes by 2°-7°C. Compared with known systems in bacterial and Drosophila species, these results indicate similar base-pair mismatches for host and endosymbiont DNAs. From these correlations, we deduce that the endosymbionts have probably been associated with their host cockroaches since before the latter speciated.}, }
@article {pmid29320241, year = {1984}, author = {Fisher, MR and Hand, SC}, title = {CHEMOAUTOTROPHIC SYMBIONTS IN THE BIVALVE LUCINA FLORIDANA FROM SEAGRASS BEDS.}, journal = {The Biological bulletin}, volume = {167}, number = {2}, pages = {445-459}, doi = {10.2307/1541289}, pmid = {29320241}, issn = {1939-8697}, abstract = {Enzymatic and histological evidence suggest that the eulamellibranch bivalve Lucina fioridana possesses bacterial endosymbionts capable of a chemoautotrophic metabolism. Dense populations of L. floridana (83 ± 11 per m[2]; 95% CI, n = 33) are found closely associated with the O2-releasing root systems of seagrasses in sulfiderich sediments; the sandy sediments of both Thalassia and Ruppia beds contain 1.67 ± 0.3 1 mM (95% CI, n = 13) and 2.49 ± 0.55 mM (95% CI, n = 13) sulfide, respectively. Both transmission electron microscopy of gill tissue and scanning electron microscopy of freeze-fractured gills reveal numerous rod-shaped procaryotic inclusions in vacuoles of large, eucaryotic cells ("bacteriocytes") located deeply within demibranch cross sections; no such inclusions are seen in the ciliated gill epitheium which is rich in mitochondria. Activities of ribulose 1,5-bisphosphate carboxylase (RuBPCase), phosphoribulokinase, APS reductase, ATP sulfurylase, and nitrite reductase have been measured and partially characterized in homogenates of fresh gill tissue. Light microscopy reveals numerous aggregations of pigmented granules localized to the interior of the gill in association with the bacteriocytes. Histochemical staining demonstrates the presence of iron in these granules, consistent with the idea that their composition, in part, may be respiratory pigment and/or iron-containing cytochromes. Energy dispersive X-ray analysis reveals sulfur as a dominant inorganic element in the gill tissue. Based on abundance data of L. fioridana and in vitro levels of RuBPCase (half-maximal velocity) this bivalve could potentially contribute 336 ± 96 g C/m[2]/year (95% CI) to the gross carbon fixation of seagrass beds.}, }
@article {pmid28399204, year = {2017}, author = {Huang, Y and Zhao, L and Zhang, Z and Liu, M and Xue, Z and Ma, D and Sun, X and Sun, Y and Zhou, C and Qin, X and Zhu, Y and Li, W and Yu, H and Yu, XJ}, title = {Detection of a Novel Rickettsia From Leptotrombidium scutellare Mites (Acari: Trombiculidae) From Shandong of China.}, journal = {Journal of medical entomology}, volume = {54}, number = {3}, pages = {544-549}, doi = {10.1093/jme/tjw234}, pmid = {28399204}, issn = {1938-2928}, mesh = {Animals ; Bacterial Proteins/genetics ; China/epidemiology ; Mite Infestations/epidemiology/parasitology/veterinary ; Murinae ; Phylogeny ; Prevalence ; RNA, Bacterial/genetics ; Rickettsia/*classification/genetics/isolation &amp; purification ; Rickettsia Infections/epidemiology/microbiology/*veterinary ; Rodent Diseases/*epidemiology/microbiology ; *Rodentia ; Sequence Analysis, DNA/veterinary ; *Shrews ; Trombiculidae/*microbiology/virology ; }, abstract = {Leptotrombidium scutellare mites, the vector of Orientia tsutsugamushi, have rarely been reported to associate with Rickettsia species. Three hundred nineteen chiggers were collected from the ears of 32 rodents captured in Huangdao District of Qingdao City, China, in October 2015. The chigger samples were tested for Rickettsia, severe fever with thrombocytopenia syndrome virus, and hantavirus by PCR or RT-PCR amplification. All mites were classified morphologically and molecularly as L. scutellare chiggers. Rickettsial DNA sequences were amplified for four genes including 16S rRNA, ompB, gltA, and 17 kD protein genes. The minimum infection rate (MIR; number of positive pools/total specimens tested) of the Rickettsia species in the chiggers were 2.8% (9/319). Phylogenetic analysis indicated that individual genes were closely related to different Rickettsia species including R. felis (with 16S rRNA gene), R. australis (with gltA gene), an unnamed Rickettsia sp. TwKM02 (with ompB gene), and Rickettsia endosymbiont of soft tick Ornithodoros erraticus (with 17 kD protein gene). Phylogenic analysis of the concatenated sequence of 16S rRNA, gltA, ompB, and 17 kD protein genes indicated that the Rickettsia species from L. scutellare chigger was most closely related to R. australis and R. akari. These results indicated that the Rickettsia species in chiggers was unique; it was named Candidatus Rickettsia leptotrombidium. Severe fever with thrombocytopenia syndrome virus and hantavirus were not amplified from the chiggers, suggesting lack of infection of these pathogens in the chiggers. A unique Rickettsia species was detected in L. scutellare, which expanded the knowledge on the vector distribution of Rickettsia.}, }
@article {pmid28394446, year = {2017}, author = {Stopka, SA and Agtuca, BJ and Koppenaal, DW and Paša-Tolić, L and Stacey, G and Vertes, A and Anderton, CR}, title = {Laser-ablation electrospray ionization mass spectrometry with ion mobility separation reveals metabolites in the symbiotic interactions of soybean roots and rhizobia.}, journal = {The Plant journal : for cell and molecular biology}, volume = {91}, number = {2}, pages = {340-354}, doi = {10.1111/tpj.13569}, pmid = {28394446}, issn = {1365-313X}, mesh = {Bradyrhizobium/*physiology ; Equipment Design ; Lasers ; Plant Roots/metabolism/*microbiology ; Root Nodules, Plant/microbiology ; Soybeans/*metabolism/*microbiology ; Spectrometry, Mass, Electrospray Ionization/instrumentation/methods ; Symbiosis ; }, abstract = {Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen-fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule) where the exchange of nutrients between host and endosymbiont occurs. Laser-ablation electrospray ionization mass spectrometry (LAESI-MS) is a method that can be performed under ambient conditions requiring minimal sample preparation. Here, we employed LAESI-MS to explore the well characterized symbiosis between soybean (Glycine max L. Merr.) and its compatible symbiont, Bradyrhizobium japonicum. The utilization of ion mobility separation (IMS) improved the molecular coverage, selectivity, and identification of the detected biomolecules. Specifically, incorporation of IMS resulted in an increase of 153 differentially abundant spectral features in the nodule samples. The data presented demonstrate the advantages of using LAESI-IMS-MS for the rapid analysis of intact root nodules, uninfected root segments, and free-living rhizobia. Untargeted pathway analysis revealed several metabolic processes within the nodule (e.g., zeatin, riboflavin, and purine synthesis). Compounds specific to the uninfected root and bacteria were also detected. Lastly, we performed depth profiling of intact nodules to reveal the location of metabolites to the cortex and inside the infected region, and lateral profiling of sectioned nodules confirmed these molecular distributions. Our results established the feasibility of LAESI-IMS-MS for the analysis and spatial mapping of plant tissues, with its specific demonstration to improve our understanding of the soybean-rhizobial symbiosis.}, }
@article {pmid28391089, year = {2017}, author = {Prudent, J and McBride, HM}, title = {The mitochondria-endoplasmic reticulum contact sites: a signalling platform for cell death.}, journal = {Current opinion in cell biology}, volume = {47}, number = {}, pages = {52-63}, doi = {10.1016/j.ceb.2017.03.007}, pmid = {28391089}, issn = {1879-0410}, support = {MC_UU_00015/7/MRC_/Medical Research Council/United Kingdom ; PT-71405//CIHR/Canada ; MC_UP_1601/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; *Apoptosis ; Calcium/metabolism ; Cytosol/metabolism ; Endoplasmic Reticulum/*metabolism ; Humans ; Mitochondria/*metabolism ; Mitochondrial Dynamics ; Mitochondrial Membranes/metabolism ; }, abstract = {Mitochondria evolved as an endosymbiont providing the cell with a dizzying array of catabolic and anabolic processes essential for life. However, mitochondria have retained the ability to kill from within, and are widely considered the final executioners of programmed cell death. The groundbreaking discovery over 25 years ago that mitochondrial cytochrome c is released into the cytosol shone new and unexpected light onto this old organelle, revitalizing the field. The Bcl-2 family of proteins plays a central role in the maintenance of mitochondrial membrane integrity, but other factors are also involved in the cell death program. Indeed, contacts with the endoplasmic reticulum (ER), mitochondrial division and inner membrane cristae remodeling have emerged as key regulators of cytochrome c release. This review will focus on recent progress to define the functional contribution of the apoptotic ER/mitochondrial interface, which couples mitochondrial fission and cristae remodeling to calcium and lipid fluxes.}, }
@article {pmid28390081, year = {2017}, author = {Klein, SG and Pitt, KA and Nitschke, MR and Goyen, S and Welsh, DT and Suggett, DJ and Carroll, AR}, title = {Symbiodinium mitigate the combined effects of hypoxia and acidification on a noncalcifying cnidarian.}, journal = {Global change biology}, volume = {23}, number = {9}, pages = {3690-3703}, doi = {10.1111/gcb.13718}, pmid = {28390081}, issn = {1365-2486}, mesh = {Animals ; *Cnidaria ; *Dinoflagellida ; Hydrogen-Ion Concentration ; *Hypoxia ; Photosynthesis ; *Symbiosis ; }, abstract = {Anthropogenic nutrient inputs enhance microbial respiration within many coastal ecosystems, driving concurrent hypoxia and acidification. During photosynthesis, Symbiodinium spp., the microalgal endosymbionts of cnidarians and other marine phyla, produce O2 and assimilate CO2 and thus potentially mitigate the exposure of the host to these stresses. However, such a role for Symbiodinium remains untested for noncalcifying cnidarians. We therefore contrasted the fitness of symbiotic and aposymbiotic polyps of a model host jellyfish (Cassiopea sp.) under reduced O2 (~2.09 mg/L) and pH (~ 7.63) scenarios in a full-factorial experiment. Host fitness was characterized as asexual reproduction and their ability to regulate internal pH and Symbiodinium performance characterized by maximum photochemical efficiency, chla content and cell density. Acidification alone resulted in 58% more asexual reproduction of symbiotic polyps than aposymbiotic polyps (and enhanced Symbiodinium cell density) suggesting Cassiopea sp. fitness was enhanced by CO2 -stimulated Symbiodinium photosynthetic activity. Indeed, greater CO2 drawdown (elevated pH) was observed within host tissues of symbiotic polyps under acidification regardless of O2 conditions. Hypoxia alone produced 22% fewer polyps than ambient conditions regardless of acidification and symbiont status, suggesting Symbiodinium photosynthetic activity did not mitigate its effects. Combined hypoxia and acidification, however, produced similar numbers of symbiotic polyps compared with aposymbiotic kept under ambient conditions, demonstrating that the presence of Symbiodinium was key for mitigating the combined effects of hypoxia and acidification on asexual reproduction. We hypothesize that this mitigation occurred because of reduced photorespiration under elevated CO2 conditions where increased net O2 production ameliorates oxygen debt. We show that Symbiodinium play an important role in facilitating enhanced fitness of Cassiopea sp. polyps, and perhaps also other noncalcifying cnidarian hosts, to the ubiquitous effects of ocean acidification. Importantly we highlight that symbiotic, noncalcifying cnidarians may be particularly advantaged in productive coastal waters that are subject to simultaneous hypoxia and acidification.}, }
@article {pmid28387771, year = {2017}, author = {Bonfante, P and Desirò, A}, title = {Who lives in a fungus? The diversity, origins and functions of fungal endobacteria living in Mucoromycota.}, journal = {The ISME journal}, volume = {11}, number = {8}, pages = {1727-1735}, pmid = {28387771}, issn = {1751-7370}, mesh = {Bacteria/*genetics ; Biological Evolution ; Fungi/*classification/*physiology ; *Symbiosis ; Tenericutes/*genetics/physiology ; }, abstract = {Bacterial interactions with plants and animals have been examined for many years; differently, only with the new millennium the study of bacterial-fungal interactions blossomed, becoming a new field of microbiology with relevance to microbial ecology, human health and biotechnology. Bacteria and fungi interact at different levels and bacterial endosymbionts, which dwell inside fungal cells, provide the most intimate example. Bacterial endosymbionts mostly occur in fungi of the phylum Mucoromycota and include Betaproteobacteria (Burkhoderia-related) and Mollicutes (Mycoplasma-related). Based on phylogenomics and estimations of divergence time, we hypothesized two different scenarios for the origin of these interactions (early vs late bacterial invasion). Sequencing of the genomes of fungal endobacteria revealed a significant reduction in genome size, particularly in endosymbionts of Glomeromycotina, as expected by their uncultivability and host dependency. Similar to endobacteria of insects, the endobacteria of fungi show a range of behaviours from mutualism to antagonism. Emerging results suggest that some benefits given by the endobacteria to their plant-associated fungal host may propagate to the interacting plant, giving rise to a three-level inter-domain interaction.}, }
@article {pmid28386769, year = {2017}, author = {Fromont, C and Riegler, M and Cook, JM}, title = {Relative Abundance and Strain Diversity in the Bacterial Endosymbiont Community of a Sap-Feeding Insect Across Its Native and Introduced Geographic Range.}, journal = {Microbial ecology}, volume = {74}, number = {3}, pages = {722-734}, pmid = {28386769}, issn = {1432-184X}, mesh = {Animals ; Australia ; Bacteria/*classification/genetics ; *Bacterial Physiological Phenomena ; Female ; Ficus/growth &amp; development ; Hemiptera/growth &amp; development/*microbiology ; Herbivory ; High-Throughput Nucleotide Sequencing ; Male ; *Microbiota ; New Zealand ; Nymph/growth &amp; development/microbiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Most insects are associated with bacterial symbionts. The bacterial diversity and community composition within hosts may play an important role in shaping insect population biology, ecology and evolution. We focussed on the bacterial microbiome of the Australian fig homotomid Mycopsylla fici (Hemiptera: Psylloidea), which can cause defoliation of its only host tree, Ficus macrophylla. This sap-feeding insect is native to mainland Australia and Lord Howe Island (LHI) but also occurs where its host has been planted, notably in New Zealand. By using a high-throughput 16S rDNA amplicon sequencing approach, we compared the bacterial diversity and community composition in individual adult males of four host populations, Sydney, Brisbane, LHI and Auckland. We also compared males, females and nymphs of the Sydney population. The microbiome of M. fici was simple and consisted mostly of the following three maternally inherited endosymbiont species: the primary endosymbiont Carsonella, a secondary (S-) endosymbiont and Wolbachia. However, the relative abundance of their sequence reads varied between host populations, except for similarities between Sydney and Auckland. In addition, insects from Sydney and Auckland had identical bacterial strains supporting the hypothesis that Sydney is the source population for Auckland. In contrast, mainland and LHI populations harboured the same S-endosymbiont, co-diverged Carsonella but different Wolbachia strains. Besides detecting endosymbiont-specific patterns of either co-evolution or horizontal acquisition, our study highlights that relative abundance of maternally inherited endosymbionts should also be taken into account when studying bacterial communities across host populations, as variations in bacterial density may impact host biology and ecology.}, }
@article {pmid28386418, year = {2017}, author = {Ramsey, JS and Chavez, JD and Johnson, R and Hosseinzadeh, S and Mahoney, JE and Mohr, JP and Robison, F and Zhong, X and Hall, DG and MacCoss, M and Bruce, J and Cilia, M}, title = {Protein interaction networks at the host-microbe interface in Diaphorina citri, the insect vector of the citrus greening pathogen.}, journal = {Royal Society open science}, volume = {4}, number = {2}, pages = {160545}, pmid = {28386418}, issn = {2054-5703}, abstract = {The Asian citrus psyllid (Diaphorina citri) is the insect vector responsible for the worldwide spread of 'Candidatus Liberibacter asiaticus' (CLas), the bacterial pathogen associated with citrus greening disease. Developmental changes in the insect vector impact pathogen transmission, such that D. citri transmission of CLas is more efficient when bacteria are acquired by nymphs when compared with adults. We hypothesize that expression changes in the D. citri immune system and commensal microbiota occur during development and regulate vector competency. In support of this hypothesis, more proteins, with greater fold changes, were differentially expressed in response to CLas in adults when compared with nymphs, including insect proteins involved in bacterial adhesion and immunity. Compared with nymphs, adult insects had a higher titre of CLas and the bacterial endosymbionts Wolbachia, Profftella and Carsonella. All Wolbachia and Profftella proteins differentially expressed between nymphs and adults are upregulated in adults, while most differentially expressed Carsonella proteins are upregulated in nymphs. Discovery of protein interaction networks has broad applicability to the study of host-microbe relationships. Using protein interaction reporter technology, a D. citri haemocyanin protein highly upregulated in response to CLas was found to physically interact with the CLas coenzyme A (CoA) biosynthesis enzyme phosphopantothenoylcysteine synthetase/decarboxylase. CLas pantothenate kinase, which catalyses the rate-limiting step of CoA biosynthesis, was found to interact with a D. citri myosin protein. Two Carsonella enzymes involved in histidine and tryptophan biosynthesis were found to physically interact with D. citri proteins. These co-evolved protein interaction networks at the host-microbe interface are highly specific targets for controlling the insect vector responsible for the spread of citrus greening.}, }
@article {pmid28382021, year = {2017}, author = {Shaffer, JP and U'Ren, JM and Gallery, RE and Baltrus, DA and Arnold, AE}, title = {An Endohyphal Bacterium (Chitinophaga, Bacteroidetes) Alters Carbon Source Use by Fusarium keratoplasticum (F. solani Species Complex, Nectriaceae).}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {350}, pmid = {28382021}, issn = {1664-302X}, abstract = {Bacterial endosymbionts occur in diverse fungi, including members of many lineages of Ascomycota that inhabit living plants. These endosymbiotic bacteria (endohyphal bacteria, EHB) often can be removed from living fungi by antibiotic treatment, providing an opportunity to assess their effects on functional traits of their fungal hosts. We examined the effects of an endohyphal bacterium (Chitinophaga sp., Bacteroidetes) on substrate use by its host, a seed-associated strain of the fungus Fusarium keratoplasticum, by comparing growth between naturally infected and cured fungal strains across 95 carbon sources with a Biolog® phenotypic microarray. Across the majority of substrates (62%), the strain harboring the bacterium significantly outperformed the cured strain as measured by respiration and hyphal density. These substrates included many that are important for plant- and seed-fungus interactions, such as D-trehalose, myo-inositol, and sucrose, highlighting the potential influence of EHB on the breadth and efficiency of substrate use by an important Fusarium species. Cases in which the cured strain outperformed the strain harboring the bacterium were observed in only 5% of substrates. We propose that additive or synergistic substrate use by the fungus-bacterium pair enhances fungal growth in this association. More generally, alteration of the breadth or efficiency of substrate use by dispensable EHB may change fungal niches in short timeframes, potentially shaping fungal ecology and the outcomes of fungal-host interactions.}, }
@article {pmid28374537, year = {2017}, author = {Wang, Y and Xu, C and Tian, M and Deng, X and Cen, Y and He, Y}, title = {Genetic diversity of Diaphorina citri and its endosymbionts across east and south-east Asia.}, journal = {Pest management science}, volume = {73}, number = {10}, pages = {2090-2099}, doi = {10.1002/ps.4582}, pmid = {28374537}, issn = {1526-4998}, mesh = {Animals ; Asia, Southeastern ; Bacterial Proteins/genetics ; Betaproteobacteria/*genetics/physiology ; China ; Electron Transport Complex IV/genetics ; Florida ; *Genetic Variation ; Halomonadaceae/*genetics/physiology ; Hemiptera/*genetics/microbiology ; Insect Proteins/genetics ; Mitochondrial Proteins/genetics ; Pakistan ; *Symbiosis ; }, abstract = {BACKGROUND: Diaphorina citri is the vector of 'Candidatus Liberibacter asiaticus', the most widespread pathogen associated huanglongbing, the most serious disease of citrus. To enhance our understanding of the distribution and origin of the psyllid, we investigated the genetic diversity and population structures of 24 populations in Asia and one from Florida based on the mtCOI gene. Simultaneously, genetic diversity and population structures of the primary endosymbiont (P-endosymbiont) 'Candidatus Carsonella ruddii' and secondary endosymbiont (S-endosymbiont) 'Candidatus Profftella armatura' of D. citri were determined with the housekeeping genes.<br><br>RESULT: AMOVA analysis indicated that populations of D. citri and its endosymbionts in east and south-east Asia were genetically distinct from populations in Pakistan and Florida. Furthermore, P-endosymbiont populations displayed a strong geographical structure across east and south-east Asia, while low genetic diversity indicated the absence of genetic structure among the populations of D. citri and its S-endosymbiont across these regions.<br><br>CONCLUSION: The 'Ca. C. ruddii' is more diverse and structured than the D. citri and the 'Ca. P. armatura' across east and south-east Asia. Multiple introductions of the psyllid have occurred in China. Management application for controlling the pest is proposed based on the genetic information of D. citri and its endosymbionts. &#xa9; 2017 Society of Chemical Industry.}, }
@article {pmid28371652, year = {2017}, author = {Loyola-Machado, AC and Azevedo-Martins, AC and Catta-Preta, CMC and de Souza, W and Galina, A and Motta, MCM}, title = {The Symbiotic Bacterium Fuels the Energy Metabolism of the Host Trypanosomatid Strigomonas culicis.}, journal = {Protist}, volume = {168}, number = {2}, pages = {253-269}, doi = {10.1016/j.protis.2017.02.001}, pmid = {28371652}, issn = {1618-0941}, mesh = {*Bacterial Physiological Phenomena ; Energy Metabolism ; *Symbiosis ; Trypanosomatina/*microbiology ; }, abstract = {The mutualistic relationship between trypanosomatids and their respective endosymbiotic bacteria represents an excellent model for studying metabolic co-evolution since the symbiont completes essential biosynthetic routes of the host cell. In this work, we investigated the influence of the endosymbiont on the energy metabolism of Strigomonas culicis by comparing the wild strain with aposymbiotic protists. The bacterium maintains a frequent and close association with glycosomes, which are distributed around the prokaryote. Furthermore, 3D reconstructions revealed that the shape and distribution of glycosomes are different in symbiont-bearing protists compared to symbiont-free cells. Results of bioenergetic assays showed that the presence of the symbiont enhances the O2 consumption of the host cell. When the quantity of intracellular or released glycerol was evaluated, the aposymbiotic strain presented higher values when compared to symbiont-containing cells. Furthermore, inhibition of oxidative phosphorylation by potassium cyanide increased the rate of glycerol release and slightly diminished the ATP content in cells without the symbiont, indicating that the host trypanosomatid enhances its fermentative activity when the bacterium is lost.}, }
@article {pmid28371395, year = {2017}, author = {Skidmore, IH and Hansen, AK}, title = {The evolutionary development of plant-feeding insects and their nutritional endosymbionts.}, journal = {Insect science}, volume = {24}, number = {6}, pages = {910-928}, doi = {10.1111/1744-7917.12463}, pmid = {28371395}, issn = {1744-7917}, mesh = {Animals ; *Biological Evolution ; Gene Expression Regulation ; Genes, Insect ; *Herbivory ; Insecta/*microbiology/physiology ; *Symbiosis ; }, abstract = {Herbivorous insects have evolved diverse mechanisms enabling them to feed on plants with suboptimal nutrient availability. Low nutrient availability negatively impacts insect herbivore development and fitness. To overcome this obstacle numerous insect lineages have evolved intimate associations with nutritional endosymbionts. This is especially true for insects that specialize on nitrogen-poor substrates, as these insects are highly dependent on intracellular symbionts to provide nitrogen lacking in their insect host's diet. Emerging evidence in these systems suggest that the symbiont's and/or the insect's biosynthetic pathways are dynamically regulated throughout the insect's development to potentially cope with the insect's changing nutritional demands. In this review, we evaluate the evolutionary development of symbiotic insect cells (bacteriocytes) by comparing and contrasting genes and mechanisms involved in maintaining and regulating the nutritional symbiosis throughout insect development in a diversity of insect herbivore-endosymbiont associations. With new advances in genome sequencing and functional genomics, we evaluate to what extent nutritional symbioses are shaped by (i) the regulation of symbiont titer, (ii) the regulation of insect symbiosis genes, and (iii) the regulation of symbiont genes. We discuss how important these mechanisms are for the biosynthesis of essential amino acids and vitamins across insect life stages in divergent insect-symbiont systems. We conclude by suggesting future directions of research to further elucidate the evolutionary development of bacteriocytes and the impact of these nutritional symbioses on insect-plant interactions.}, }
@article {pmid28369561, year = {2017}, author = {Théry, T and Brockerhoff, EG and Carnegie, AJ and Chen, R and Elms, SR and Hullé, M and Glatz, R and Ortego, J and Qiao, GX and Turpeau, &#xc9; and Favret, C}, title = {EF-1α DNA Sequences Indicate Multiple Origins of Introduced Populations of Essigella californica (Hemiptera: Aphididae).}, journal = {Journal of economic entomology}, volume = {110}, number = {3}, pages = {1269-1274}, doi = {10.1093/jee/tox026}, pmid = {28369561}, issn = {1938-291X}, mesh = {Animals ; Aphids/*genetics ; Bacterial Proteins/*genetics ; Buchnera/*genetics ; Cell Nucleus/genetics ; *Genetic Variation ; Insect Proteins/*genetics ; Introduced Species ; Mitochondrial Proteins/genetics ; Peptide Elongation Factor 1/*genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Aphids in the pine-feeding Nearctic genus Essigella (Sternorrhyncha, Aphididae, Lachninae) have been introduced in Europe, North Africa, Oceania, and South America. Mitochondrial, nuclear, and endosymbiont DNA sequences of 12 introduced populations from three continents confirm they all belong to Essigella californica (Essig, 1909). Intron sequence variation of the nuclear gene EF-1α has revealed the existence of four distinct groups. Group I gathers one population from China, where the species is newly reported, and several from Europe (France and Italy); Group II is represented by one population from Argentina; Group III includes two populations from Southern Australia with one from New Zealand; and Group IV corresponds to five populations from Eastern and South-Eastern Australia. These results indicate that introduced populations of E. californica have at least four source populations. They also show that intron variation of EF-1α can be a method to discriminate populations of asexually reproducing aphids.}, }
@article {pmid28368313, year = {2017}, author = {Balczun, C and Scheid, PL}, title = {Free-Living Amoebae as Hosts for and Vectors of Intracellular Microorganisms with Public Health Significance.}, journal = {Viruses}, volume = {9}, number = {4}, pages = {}, pmid = {28368313}, issn = {1999-4915}, mesh = {Amoeba/*microbiology/parasitology/*virology ; Animals ; *Disease Transmission, Infectious ; *Disease Vectors ; Humans ; }, abstract = {Free-living amoebae (FLA) are parasites within both humans and animals causing a wide range of symptoms and act as hosts of, and vehicles for phylogenetically diverse microorganisms, called endocytobionts. The interaction of the FLA with sympatric microorganisms leads to an exceptional diversity within FLA. Some of these bacteria, viruses, and even eukaryotes, can live and replicate intracellularly within the FLA. This relationship provides protection to the microorganisms from external interventions and a dispersal mechanism across various habitats. Among those intracellularly-replicating or -residing organisms there are obligate and facultative pathogenic microorganisms affecting the health of humans or animals and are therefore of interest to Public Health Authorities. Mimiviruses, Pandoraviruses, and Pithoviruses are examples for interesting viral endocytobionts within FLA. Future research is expected to reveal further endocytobionts within free-living amoebae and other protozoa through co-cultivation studies, genomic, transcriptomic, and proteomic analyses.}, }
@article {pmid28366838, year = {2017}, author = {Fichorova, R and Fraga, J and Rappelli, P and Fiori, PL}, title = {Trichomonas vaginalis infection in symbiosis with Trichomonasvirus and Mycoplasma.}, journal = {Research in microbiology}, volume = {168}, number = {9-10}, pages = {882-891}, pmid = {28366838}, issn = {1769-7123}, support = {R01 AI079085/AI/NIAID NIH HHS/United States ; R56 AI091889/AI/NIAID NIH HHS/United States ; P30 HD018655/HD/NICHD NIH HHS/United States ; R21 HD054451/HD/NICHD NIH HHS/United States ; RC1 AI086788/AI/NIAID NIH HHS/United States ; }, mesh = {Female ; Humans ; Mycoplasma/*isolation &amp; purification ; Totiviridae/*isolation &amp; purification ; Trichomonas/virology ; Trichomonas Vaginitis/parasitology ; Trichomonas vaginalis/*isolation &amp; purification ; Vagina/*microbiology/*parasitology ; Vaginitis/*microbiology/*parasitology ; }, abstract = {Trichomonas vaginalis is a protozoan with an extracellular obligatory parasitic lifestyle exclusively adapted to the human urogenital tract and responsible for nearly a quarter billion sexually transmitted infections worldwide each year. This review focuses on symbiotic Trichomonasvirus and mycoplasmas carried by the protozoan, their molecular features and their role in altering the human vaginal microbiome and the immunopathogenicity of the parasite. Improved diagnostics and larger clinical interventional studies are needed to confirm the causative role of protozoan symbionts in the variable clinical presentation of trichomoniasis and its morbid sequelae, including adverse reproductive outcome, susceptibility to viral infections and cancer.}, }
@article {pmid28358880, year = {2017}, author = {Grote, A and Voronin, D and Ding, T and Twaddle, A and Unnasch, TR and Lustigman, S and Ghedin, E}, title = {Defining Brugia malayi and Wolbachia symbiosis by stage-specific dual RNA-seq.}, journal = {PLoS neglected tropical diseases}, volume = {11}, number = {3}, pages = {e0005357}, pmid = {28358880}, issn = {1935-2735}, support = {R56 AI101372/AI/NIAID NIH HHS/United States ; R56 AI118936/AI/NIAID NIH HHS/United States ; T32 AI007180/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/*growth &amp; development/*microbiology ; Female ; *Gene Expression Profiling ; Sequence Analysis, RNA ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Filarial nematodes currently infect up to 54 million people worldwide, with millions more at risk for infection, representing the leading cause of disability in the developing world. Brugia malayi is one of the causative agents of lymphatic filariasis and remains the only human filarial parasite that can be maintained in small laboratory animals. Many filarial nematode species, including B. malayi, carry an obligate endosymbiont, the alpha-proteobacteria Wolbachia, which can be eliminated through antibiotic treatment. Elimination of the endosymbiont interferes with development, reproduction, and survival of the worms within the mamalian host, a clear indicator that the Wolbachia are crucial for survival of the parasite. Little is understood about the mechanism underlying this symbiosis.<br><br>To better understand the molecular interplay between these two organisms we profiled the transcriptomes of B. malayi and Wolbachia by dual RNA-seq across the life cycle of the parasite. This helped identify functional pathways involved in this essential symbiotic relationship provided by the co-expression of nematode and bacterial genes. We have identified significant stage-specific and gender-specific differential expression in Wolbachia during the nematode's development. For example, during female worm development we find that Wolbachia upregulate genes involved in ATP production and purine biosynthesis, as well as genes involved in the oxidative stress response.<br><br>CONCLUSIONS/ SIGNIFICANCE: This global transcriptional analysis has highlighted specific pathways to which both Wolbachia and B. malayi contribute concurrently over the life cycle of the parasite, paving the way for the development of novel intervention strategies.}, }
@article {pmid28357366, year = {2016}, author = {Caragata, EP and Dutra, HL and Moreira, LA}, title = {Inhibition of Zika virus by Wolbachia in Aedes aegypti.}, journal = {Microbial cell (Graz, Austria)}, volume = {3}, number = {7}, pages = {293-295}, doi = {10.15698/mic2016.07.513}, pmid = {28357366}, issn = {2311-2638}, abstract = {Through association with cases of microcephaly in 2015, Zika virus (ZIKV) has transitioned from a relatively unknown mosquito-transmitted pathogen to a global health emergency, emphasizing the need to improve existing mosquito control programs to prevent future disease outbreaks. The response to Zika must involve a paradigm shift from traditional to novel methods of mosquito control, and according to the World Health Organization should incorporate the release of mosquitoes infected with the bacterial endosymbiont Wolbachiapipientis. In our recent paper [Dutra, HLC et al., Cell Host &amp; Microbe 2016] we investigated the potential of Wolbachia infections in Aedes aegypti to restrict infection and transmission of Zika virus recently isolated in Brazil. Wolbachia is now well known for its ability to block or reduce infection with a variety of pathogens in different mosquito species including the dengue (DENV), yellow fever, and chikungunya viruses, and malaria-causing Plasmodium, and consequently has great potential to control mosquito-transmitted diseases across the globe. Our results demonstrated that the wMel Wolbachia strain in Brazilian Ae. aegypti is a strong inhibitor of ZIKV infection, and furthermore appears to prevent transmission of infectious viral particles in mosquito saliva, which highlights the bacterium's suitability for more widespread use in Zika control.}, }
@article {pmid28348879, year = {2017}, author = {Baltrus, DA and Dougherty, K and Arendt, KR and Huntemann, M and Clum, A and Pillay, M and Palaniappan, K and Varghese, N and Mikhailova, N and Stamatis, D and Reddy, TBK and Ngan, CY and Daum, C and Shapiro, N and Markowitz, V and Ivanova, N and Kyrpides, N and Woyke, T and Arnold, AE}, title = {Absence of genome reduction in diverse, facultative endohyphal bacteria.}, journal = {Microbial genomics}, volume = {3}, number = {2}, pages = {e000101}, pmid = {28348879}, issn = {2057-5858}, mesh = {Ascomycota/*physiology ; Bacteria/classification/*genetics/isolation &amp; purification ; Cupressaceae/microbiology ; Gene Transfer, Horizontal ; Genetic Variation ; *Genome, Bacterial ; Host Microbial Interactions/*genetics ; Hyphae/*physiology ; Plant Leaves/microbiology ; *Symbiosis ; Whole Genome Sequencing ; }, abstract = {Fungi interact closely with bacteria, both on the surfaces of the hyphae and within their living tissues (i.e. endohyphal bacteria, EHB). These EHB can be obligate or facultative symbionts and can mediate diverse phenotypic traits in their hosts. Although EHB have been observed in many lineages of fungi, it remains unclear how widespread and general these associations are, and whether there are unifying ecological and genomic features can be found across EHB strains as a whole. We cultured 11 bacterial strains after they emerged from the hyphae of diverse Ascomycota that were isolated as foliar endophytes of cupressaceous trees, and generated nearly complete genome sequences for all. Unlike the genomes of largely obligate EHB, the genomes of these facultative EHB resembled those of closely related strains isolated from environmental sources. Although all analysed genomes encoded structures that could be used to interact with eukaryotic hosts, pathways previously implicated in maintenance and establishment of EHB symbiosis were not universally present across all strains. Independent isolation of two nearly identical pairs of strains from different classes of fungi, coupled with recent experimental evidence, suggests horizontal transfer of EHB across endophytic hosts. Given the potential for EHB to influence fungal phenotypes, these genomes could shed light on the mechanisms of plant growth promotion or stress mitigation by fungal endophytes during the symbiotic phase, as well as degradation of plant material during the saprotrophic phase. As such, these findings contribute to the illumination of a new dimension of functional biodiversity in fungi.}, }
@article {pmid28348369, year = {2017}, author = {Tay, WT and Elfekih, S and Polaszek, A and Court, LN and Evans, GA and Gordon, KH and De Barro, PJ}, title = {Novel molecular approach to define pest species status and tritrophic interactions from historical Bemisia specimens.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {429}, pmid = {28348369}, issn = {2045-2322}, mesh = {Animals ; Asia ; Bacteria/genetics ; DNA, Mitochondrial/*chemistry/*genetics ; Electron Transport Complex IV/genetics ; *Fossils ; Hemiptera/*genetics ; High-Throughput Nucleotide Sequencing ; Hymenoptera/genetics ; Metagenomics ; Sequence Analysis, DNA ; Sequence Homology ; }, abstract = {Museum specimens represent valuable genomic resources for understanding host-endosymbiont/parasitoid evolutionary relationships, resolving species complexes and nomenclatural problems. However, museum collections suffer DNA degradation, making them challenging for molecular-based studies. Here, the mitogenomes of a single 1912 Sri Lankan Bemisia emiliae cotype puparium, and of a 1942 Japanese Bemisia puparium are characterised using a Next-Generation Sequencing approach. Whiteflies are small sap-sucking insects including B. tabaci pest species complex. Bemisia emiliae's draft mitogenome showed a high degree of homology with published B. tabaci mitogenomes, and exhibited 98-100% partial mitochondrial DNA Cytochrome Oxidase I (mtCOI) gene identity with the B. tabaci species known as Asia II-7. The partial mtCOI gene of the Japanese specimen shared 99% sequence identity with the Bemisia 'JpL' genetic group. Metagenomic analysis identified bacterial sequences in both Bemisia specimens, while hymenopteran sequences were also identified in the Japanese Bemisia puparium, including complete mtCOI and rRNA genes, and various partial mtDNA genes. At 88-90% mtCOI sequence identity to Aphelinidae wasps, we concluded that the 1942 Bemisia nymph was parasitized by an Eretmocerus parasitoid wasp. Our approach enables the characterisation of genomes and associated metagenomic communities of museum specimens using 1.5 ng gDNA, and to infer historical tritrophic relationships in Bemisia whiteflies.}, }
@article {pmid28345060, year = {2017}, author = {Tian, RM and Zhang, W and Cai, L and Wong, YH and Ding, W and Qian, PY}, title = {Genome Reduction and Microbe-Host Interactions Drive Adaptation of a Sulfur-Oxidizing Bacterium Associated with a Cold Seep Sponge.}, journal = {mSystems}, volume = {2}, number = {2}, pages = {}, pmid = {28345060}, issn = {2379-5077}, abstract = {As the most ancient metazoan, sponges have established close relationships with particular microbial symbionts. However, the characteristics and physiology of thioautotrophic symbionts in deep-sea sponges are largely unknown. Using a tailored "differential coverage binning" method on 22-Gb metagenomic sequences, we recovered the nearly complete genome of a sulfur-oxidizing bacterium (SOB) that dominates the microbiota of the cold seep sponge Suberites sp. Phylogenetic analyses suggested that this bacterium (an unclassified gammaproteobacterium termed "Gsub") may represent a new deep-sea SOB group. Microscopic observations suggest that Gsub is probably an extracellular symbiont. Gsub has complete sulfide oxidation and carbon fixation pathways, suggesting a chemoautotrophic lifestyle. Comparative genomics with other sponge-associated SOB and free-living SOB revealed significant genome reduction in Gsub, characterized by the loss of genes for carbohydrate metabolism, motility, DNA repair, and osmotic stress response. Intriguingly, this scenario of genome reduction is highly similar to those of the endosymbionts in deep-sea clams. However, Gsub has retained genes for phage defense and protein secretion, with the latter potentially playing a role in interactions with the sponge host. In addition, we recovered the genome of an ammonia-oxidizing archaeon (AOA), which may carry out ammonia oxidation and carbon fixation within the sponge body. IMPORTANCE Sponges and their symbionts are important players in the biogeochemical cycles of marine environments. As a unique habitat within marine ecosystems, cold seeps have received considerable interest in recent years. This study explores the lifestyle of a new symbiotic SOB in a cold seep sponge. The results demonstrate that both this sponge symbiont and endosymbionts in deep-sea clams employ similar strategies of genome reduction. However, this bacterium has retained unique functions for immunity and defense. Thus, the functional features are determined by both the symbiotic relationship and host type. Moreover, analyses of the genome of an AOA suggest that microbes play different roles in biochemical cycles in the sponge body. Our findings provide new insights into invertebrate-associated bacteria in cold seep environments.}, }
@article {pmid28345029, year = {2017}, author = {Ruiz-Jones, LJ and Palumbi, SR}, title = {Tidal heat pulses on a reef trigger a fine-tuned transcriptional response in corals to maintain homeostasis.}, journal = {Science advances}, volume = {3}, number = {3}, pages = {e1601298}, pmid = {28345029}, issn = {2375-2548}, mesh = {Animals ; Anthozoa/*metabolism ; *Gene Expression Profiling ; *Gene Expression Regulation ; *Hot Temperature ; Hydrogen-Ion Concentration ; Oxygen/metabolism ; *Stress, Physiological ; *Transcription, Genetic ; *Unfolded Protein Response ; }, abstract = {For reef-building corals, extreme stress exposure can result in loss of endosymbionts, leaving colonies bleached. However, corals in some habitats are commonly exposed to natural cycles of sub-bleaching stress, often leading to higher stress tolerance. We monitored transcription in the tabletop coral Acropora hyacinthus daily for 17 days over a strong tidal cycle that included extreme temperature spikes, and show that increases in temperature above 30.5°C triggered a strong transcriptional response. The transcriptomic time series data allowed us to identify a set of genes with coordinated expression that were activated only on days with strong tides, high temperature, and large diel pH and oxygen changes. The responsive genes are enriched for gene products essential to the unfolded protein response, an ancient cellular response to endoplasmic reticulum stress. After the temporary heat pulses passed, expression of these genes immediately decreased, suggesting that homeostasis was restored to the endoplasmic reticulum. In a laboratory temperature stress experiment, we found that the expression of these environmentally responsive genes increased as corals bleached, showing that the unfolded protein response becomes more intense during more severe stress. Our results point to the unfolded protein response as a first line of defense that acroporid corals use when coping with environmental stress on the reef, thus enhancing our understanding of coral stress physiology during a time of major concern for reefs.}, }
@article {pmid28344097, year = {2017}, author = {Lefoulon, E and Giannelli, A and Makepeace, BL and Mutafchiev, Y and Townson, S and Uni, S and Verocai, GG and Otranto, D and Martin, C}, title = {Whence river blindness? The domestication of mammals and host-parasite co-evolution in the nematode genus Onchocerca.}, journal = {International journal for parasitology}, volume = {47}, number = {8}, pages = {457-470}, doi = {10.1016/j.ijpara.2016.12.009}, pmid = {28344097}, issn = {1879-0135}, mesh = {Animals ; Animals, Domestic/genetics/*parasitology ; *Biological Coevolution ; Electron Transport Complex IV/genetics/metabolism ; Gene Expression Regulation, Enzymologic ; Humans ; Mammals/*parasitology ; Onchocerca/*genetics/*physiology ; }, abstract = {The genus Onchocerca includes 34 described species and represents one of the largest genera of the filarial nematodes within the family Onchocercidae. Representative members of this genus are mainly parasites of ungulates, with some exceptions such as Onchocerca lupi and Onchocerca volvulus, infecting carnivores and/or humans. For a long time, the evolutionary relationships amongst onchocercids remained poorly studied, as the systematics of this genus was impaired by the high morphological variability of species included in the taxon. Although some molecular phylogenies were developed, these studies were mainly focused on bovine Onchocerca spp. and O. volvulus, including assessments of Wolbachia endosymbionts. In the present study, we analysed 13 Onchocerca spp. from a larger host spectrum using a panel of seven different genes. Analysis of the coxI marker supports its usefulness for the identification of species within the genus. The evolutionary history of the genus has been herein revised by multi-gene phylogenies, presenting three strongly supported clades of Onchocerca spp. Analyses of co-evolutionary scenarios between Onchocerca and their vertebrate hosts underline the effect of domestication on Onchocerca speciation. Our study indicates that a host switch event occurred between Bovidae, Canidae and humans. Cophylogenetic analyses between Onchocerca and the endosymbiotic bacterium Wolbachia indicate the strongest co-evolutionary pattern ever registered within the filarial nematodes. Finally, this dataset indicates that the clade composed by O. lupi, Onchocerca gutturosa, Onchocerca lienalis, Onchocerca ochengi and O. volvulus derived from recent speciation.}, }
@article {pmid28337184, year = {2017}, author = {Joshi, D and Pan, X and McFadden, MJ and Bevins, D and Liang, X and Lu, P and Thiem, S and Xi, Z}, title = {The Maternally Inheritable Wolbachia wAlbB Induces Refractoriness to Plasmodium berghei in Anopheles stephensi.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {366}, pmid = {28337184}, issn = {1664-302X}, support = {R01 AI080597/AI/NIAID NIH HHS/United States ; }, abstract = {The endosymbiont Wolbachia wAlbB induces refractoriness to Plasmodium falciparum in Anopheles stephensi, the primary mosquito vector of human malaria in the Middle East and South Asia. However, it remains unknown whether such refractoriness can be extended to other malaria species. In particular, it was reported that under very specific conditions, wAlbB can enhance Plasmodium infection in some hosts. Here, we measured the impact of wAlbB on the rodent malaria parasite Plasmodium berghei in A. stephensi by comparing the load of oocysts and sporozoites in midguts and salivary glands, respectively, between wAlbB-infected and -uninfected mosquitoes. To investigate whether wAlbB modulated mosquito immune defense against parasites, we compared the expression of the immune genes, which were previously reported to involve in antimalarial response, in both midguts and the remaining carcass tissues of mosquitoes. The stable association of wAlbB with A. stephensi resulted in reduction of parasites by more than half at the oocyst stage, and up to 91.8% at the sporzoite stage. The anti-plasmodium immune genes, including TEP1, LRIM1, Toll pathway gene Rel1 and the effector Defensin 1, were induced by wAlbB in different mosquito body tissues. These findings suggest that immune priming is a potential cause of wAlbB-mediated antimalarial response in A. stephensi. More importantly, no evidence was found for any enhancement of Plasmodium infection in A. stephensi stably infected with wAlbB. We discuss these findings with possible implementations of Wolbachia for malaria control in disease endemic areas.}, }
@article {pmid28335814, year = {2017}, author = {Prazeres, M and Ainsworth, T and Roberts, TE and Pandolfi, JM and Leggat, W}, title = {Symbiosis and microbiome flexibility in calcifying benthic foraminifera of the Great Barrier Reef.}, journal = {Microbiome}, volume = {5}, number = {1}, pages = {38}, pmid = {28335814}, issn = {2049-2618}, mesh = {Actinobacteria/classification/genetics/*isolation &amp; purification ; Bacteroidetes/classification/genetics/*isolation &amp; purification ; Base Sequence ; Coral Reefs ; Firmicutes/classification/genetics/*isolation &amp; purification ; Foraminifera/genetics/*physiology ; High-Throughput Nucleotide Sequencing ; Microbiota/genetics/*physiology ; Proteobacteria/classification/genetics/*isolation &amp; purification ; RNA, Chloroplast/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {BACKGROUND: Symbiosis is a phenomenon that allows organisms to colonise a wide range of environments and occupy a variety of ecological niches in marine environments. Large benthic foraminifera (LBF) are crucial marine calcifiers that rely on photo-endosymbionts for growth and calcification, yet the influence of environmental conditions in shaping their interactions with prokaryotic and eukaryotic associates is poorly known.<br><br>RESULTS: Here, we used next-generation sequencing to identify eukaryotic photosynthesizing and prokaryotic microbes associated with the common LBF Amphistegina lobifera across a physio-chemical gradient on the Great Barrier Reef (GBR). We collected samples from three reef sites located in the inner-, mid- and outer-shelf regions of the northern section of the GBR. Results showed the consistent presence of Bacillaryophyta as the main eukaryotic taxa associated with A. lobifera across all reef sites analysed; however, the abundance and the diversity of prokaryotic organisms varied among reef sites. Inner-shelf specimens showed the highest diversity of prokaryote associates, with a total of 231 genotypes in their core microbiome. A total of 30 taxa were identified in the core microbiome across all reef sites. Within these taxa, Proteobacteria was the most abundant bacteria present. The presence of groups such as Actinobacteria was significantly correlated with inner-shelf populations, whereas the abundance of Bacteroidetes and Firmicutes was associated with A. lobifera collected from mid- and outer-shelf reef sites.<br><br>CONCLUSIONS: We found that benthic foraminifera form stable and persistent symbiosis with eukaryotic partners, but flexible and site-specific associations with prokaryotic microbes that likely influence the ecological success of these crucial calcifying organisms on the GBR.}, }
@article {pmid28334388, year = {2017}, author = {Cooper, WR and Garczynski, SF and Horton, DR and Unruh, TR and Beers, EH and Peter, WS and Hilton, RJ}, title = {Bacterial Endosymbionts of the Psyllid Cacopsylla pyricola (Hemiptera: Psyllidae) in the Pacific Northwestern United States.}, journal = {Environmental entomology}, volume = {46}, number = {2}, pages = {393-402}, doi = {10.1093/ee/nvx031}, pmid = {28334388}, issn = {1938-2936}, mesh = {Animals ; Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Female ; Hemiptera/*microbiology ; Male ; Oregon ; Pyrus/growth &amp; development ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Seasons ; Sequence Analysis, RNA ; *Symbiosis ; Washington ; }, abstract = {Insects often have facultative associations with bacterial endosymbionts, which can alter the insects' susceptibility to parasitism, pathogens, plant defenses, and certain classes of insecticides. We collected pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), from pear orchards in Washington and Oregon, and surveyed them for the presence of bacterial endosymbionts. Adult psyllids were collected on multiple dates to allow us to assay specimens of both the summer ("summerform") and the overwintering ("winterform") morphotypes. Two endosymbionts, Arsenophonus and Phytoplasma pyri, were detected in psyllids of both morphotypes in both states. A separate survey revealed similar associations present in psyllids collected in 1987. Arsenophonus was present in 80-100% of psyllids in all growing regions. A slightly lower proportion of summerform than winterform psyllids harbored the bacterium. Arsenophonus was present in the bacteriomes and developing oocytes of most psyllids, indicating that this endosymbiont is transovarially transmitted. This bacterium was also observed in the salivary glands and midguts of some psyllids. Phytoplasma pyri was present in a greater proportion of pear psylla from orchards near Yakima, WA, than from other regions, and was present in a higher proportion of winterforms than summerforms. We did not detect Wolbachia, Profftella, or Liberibacter europaeus, which are associated with other psyllid pests, including other species of Cacopsylla. Our study is the first to survey North American populations of C. pyricola for endosymbionts, and provides a foundation for further research on how bacterial associations may influence the ecology and management of this pest.}, }
@article {pmid28333196, year = {2017}, author = {Yamada, N and Sym, SD and Horiguchi, T}, title = {Identification of Highly Divergent Diatom-Derived Chloroplasts in Dinoflagellates, Including a Description of Durinskia kwazulunatalensis sp. nov. (Peridiniales, Dinophyceae).}, journal = {Molecular biology and evolution}, volume = {34}, number = {6}, pages = {1335-1351}, doi = {10.1093/molbev/msx054}, pmid = {28333196}, issn = {1537-1719}, mesh = {Chloroplasts/*genetics/metabolism/physiology ; Diatoms/*genetics/metabolism ; Dinoflagellida/*genetics/metabolism ; Phylogeny ; Symbiosis ; }, abstract = {Dinoflagellates are known to possess chloroplasts of multiple origins derived from a red alga, a green alga, haptophytes, or diatoms. The monophyletic "dinotoms" harbor a chloroplast of diatom origin, but their chloroplasts are polyphyletic belonging to one of four genera: Chaetoceros, Cyclotella, Discostella, or Nitzschia. It has been speculated that serial replacement of diatom-derived chloroplasts by other diatoms has caused this diversity of chloroplasts. Although previous work suggested that the endosymbionts of Nitzschia origin might not be monophyletic, this has not been seriously investigated. To infer the number of replacements of diatom-derived chloroplasts in dinotoms, we analyzed the phylogenetic affinities of 14 species of dinotoms based on the endosymbiotic rbcL gene and SSU rDNA, and the host SSU rDNA. Resultant phylogenetic trees revealed that six species of Nitzschia were taken up by eight marine dinoflagellate species. Our phylogenies also indicate that four separate diatom species belonging to three genera were incorporated into the five freshwater dinotoms. Particular attention was paid to two crucially closely related species, Durinskia capensis and a novel species, D. kwazulunatalensis, because they possess distantly related Nitzschia species. This study clarified that any of a total of at least 11 diatom species in five genera are employed as an endosymbiont by 14 dinotoms, which infers a more frequent replacement of endosymbionts in the world of dinotoms than previously envisaged.}, }
@article {pmid28332822, year = {2017}, author = {Khoshmanesh, A and Christensen, D and Perez-Guaita, D and Iturbe-Ormaetxe, I and O'Neill, SL and McNaughton, D and Wood, BR}, title = {Screening of Wolbachia Endosymbiont Infection in Aedes aegypti Mosquitoes Using Attenuated Total Reflection Mid-Infrared Spectroscopy.}, journal = {Analytical chemistry}, volume = {89}, number = {10}, pages = {5285-5293}, doi = {10.1021/acs.analchem.6b04827}, pmid = {28332822}, issn = {1520-6882}, mesh = {Aedes/chemistry/*microbiology ; Aging ; Animals ; Discriminant Analysis ; Female ; Least-Squares Analysis ; Male ; Sex Factors ; Spectroscopy, Fourier Transform Infrared/*methods ; Symbiosis ; Wolbachia/*pathogenicity/physiology ; }, abstract = {Dengue fever is the most common mosquito transmitted viral infection afflicting humans, estimated to generate around 390 million infections each year in over 100 countries. The introduction of the endosymbiotic bacterium Wolbachia into Aedes aegypti mosquitoes has the potential to greatly reduce the public health burden of the disease. This approach requires extensive polymerase chain reaction (PCR) testing of the Wolbachia-infection status of mosquitoes in areas where Wolbachia-A. aegypti are released. Here, we report the first example of small organism mid-infrared spectroscopy where we have applied attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy and multivariate modeling methods to determine sex, age, and the presence of Wolbachia (wMel strain) in laboratory mosquitoes and sex and age in field mosquitoes. The prediction errors using partial least squares discriminant analysis (PLS-DA) discrimination models for laboratory studies on independent test sets ranged from 0 to 3% for age and sex grading and 3% to 5% for Wolbachia infection diagnosis using dry mosquito abdomens while field study results using an artificial neural network yielded a 10% error. The application of FT-IR analysis is inexpensive, easy to use, and portable and shows significant potential to replace the reliance on more expensive and laborious PCR assays.}, }
@article {pmid28331401, year = {2017}, author = {Zhu, XC and Chen, J and Chen, R and Jiang, LY and Qiao, GX}, title = {DNA barcoding and species delimitation of Chaitophorinae (Hemiptera, Aphididae).}, journal = {ZooKeys}, volume = {}, number = {656}, pages = {25-50}, pmid = {28331401}, issn = {1313-2989}, abstract = {Chaitophorinae aphids are widespread across Eurasia and North America, and include some important agricultural and horticultural pests. So, accurate rapid species identification is very important. Here, we used three mitochondrial genes and one endosymbiont gene to calculate and analyze the genetic distances within different datasets. For species delimitation, two distance-based methods were employed, threshold with NJ (neighbor-joining) and ABGD (Automatic Barcode Gap Discovery), and two tree-based approaches, GMYC (General Mixed Yule Coalescent) and PTP (Poisson Tree Process). The genetic interspecific divergence was clearly larger than the intraspecific divergence for four molecular markers. COI and COII genes were found to be more suitable for Chaitophorinae DNA barcoding. For species delimitation, at least one distance-based method combined with one tree-based method would be preferable. Based on the data for Chaitophorus saliniger and Laingia psammae, DNA barcoding may also reveal geographical variation.}, }
@article {pmid28326078, year = {2017}, author = {Nicks, T and Rahn-Lee, L}, title = {Inside Out: Archaeal Ectosymbionts Suggest a Second Model of Reduced-Genome Evolution.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {384}, pmid = {28326078}, issn = {1664-302X}, abstract = {Reduced-genome symbionts and their organelle counterparts, which have even smaller genomes, are essential to the lives of many organisms. But how and why have these genomes become so small? Endosymbiotic genome reduction is a product of isolation within the host, followed by massive pseudogenization and gene loss often including DNA repair mechanisms. This phenomenon can be observed in insect endosymbionts such as the bacteria Carsonella ruddii and Buchnera aphidicola. Yet endosymbionts are not the only organisms with reduced genomes. Thermophilic microorganisms experience selective pressures that cause their genomes to become more compact and efficient. Nanoarchaea are thermophilic archaeal ectosymbionts that live on the surface of archaeal hosts. Their genomes, a full order of magnitude smaller than the Escherichia coli genome, are very small and efficient. How have the genomes of nanoarchaea and late-stage insect endosymbionts, which live in drastically different environments, come to mirror each other in both genome size and efficiency? Because of their growth at extreme temperatures and their exterior association with their host, nanoarchaea appear to have experienced genome reduction differently than mesophilic insect endosymbionts. We suggest that habitat-specific mechanisms of genome reduction result in fundamentally different pathways for these two groups of organisms. With this assertion, we propose two pathways of symbiosis-driven genome reduction; isolation-symbiosis experienced by insect endosymbionts and thermal-symbiosis experienced by nanoarchaea.}, }
@article {pmid28321010, year = {2017}, author = {Pramono, AK and Kuwahara, H and Itoh, T and Toyoda, A and Yamada, A and Hongoh, Y}, title = {Discovery and Complete Genome Sequence of a Bacteriophage from an Obligate Intracellular Symbiont of a Cellulolytic Protist in the Termite Gut.}, journal = {Microbes and environments}, volume = {32}, number = {2}, pages = {112-117}, pmid = {28321010}, issn = {1347-4405}, mesh = {Animals ; Bacteriophages/*genetics/isolation &amp; purification ; Eukaryota/*virology ; Genome, Viral ; Isoptera/*microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Termites depend nutritionally on their gut microbes, and protistan, bacterial, and archaeal gut communities have been extensively studied. However, limited information is available on viruses in the termite gut. We herein report the complete genome sequence (99,517 bp) of a phage obtained during a genome analysis of "Candidatus Azobacteroides pseudotrichonymphae" phylotype ProJPt-1, which is an obligate intracellular symbiont of the cellulolytic protist Pseudotrichonympha sp. in the gut of the termite Prorhinotermes japonicus. The genome of the phage, designated ProJPt-Bp1, was circular or circularly permuted, and was not integrated into the two circular chromosomes or five circular plasmids composing the host ProJPt-1 genome. The phage was putatively affiliated with the order Caudovirales based on sequence similarities with several phage-related genes; however, most of the 52 protein-coding sequences had no significant homology to sequences in the databases. The phage genome contained a tRNA-Gln (CAG) gene, which showed the highest sequence similarity to the tRNA-Gln (CAA) gene of the host "Ca. A. pseudotrichonymphae" phylotype ProJPt-1. Since the host genome lacked a tRNA-Gln (CAG) gene, the phage tRNA gene may compensate for differences in codon usage bias between the phage and host genomes. The phage genome also contained a non-coding region with high nucleotide sequence similarity to a region in one of the host plasmids. No other phage-related sequences were found in the host ProJPt-1 genome. To the best of our knowledge, this is the first report of a phage from an obligate, mutualistic endosymbiont permanently associated with eukaryotic cells.}, }
@article {pmid28319100, year = {2017}, author = {Agarwal, V and Blanton, JM and Podell, S and Taton, A and Schorn, MA and Busch, J and Lin, Z and Schmidt, EW and Jensen, PR and Paul, VJ and Biggs, JS and Golden, JW and Allen, EE and Moore, BS}, title = {Metagenomic discovery of polybrominated diphenyl ether biosynthesis by marine sponges.}, journal = {Nature chemical biology}, volume = {13}, number = {5}, pages = {537-543}, pmid = {28319100}, issn = {1552-4469}, support = {R00 ES026620/ES/NIEHS NIH HHS/United States ; S10 OD010640/OD/NIH HHS/United States ; R01 GM107557/GM/NIGMS NIH HHS/United States ; P01 ES021921/ES/NIEHS NIH HHS/United States ; R01 CA172310/CA/NCI NIH HHS/United States ; K99 ES026620/ES/NIEHS NIH HHS/United States ; }, mesh = {Animals ; Biological Products/chemistry/*metabolism ; Bone Morphogenetic Proteins/*genetics/*metabolism ; Halogenated Diphenyl Ethers/chemistry/*metabolism ; *Metagenomics ; Molecular Structure ; Porifera/*metabolism ; }, abstract = {Naturally produced polybrominated diphenyl ethers (PBDEs) pervade the marine environment and structurally resemble toxic man-made brominated flame retardants. PBDEs bioaccumulate in marine animals and are likely transferred to the human food chain. However, the biogenic basis for PBDE production in one of their most prolific sources, marine sponges of the order Dysideidae, remains unidentified. Here, we report the discovery of PBDE biosynthetic gene clusters within sponge-microbiome-associated cyanobacterial endosymbionts through the use of an unbiased metagenome-mining approach. Using expression of PBDE biosynthetic genes in heterologous cyanobacterial hosts, we correlate the structural diversity of naturally produced PBDEs to modifications within PBDE biosynthetic gene clusters in multiple sponge holobionts. Our results establish the genetic and molecular foundation for the production of PBDEs in one of the most abundant natural sources of these molecules, further setting the stage for a metagenomic-based inventory of other PBDE sources in the marine environment.}, }
@article {pmid28314780, year = {2017}, author = {Vendramin, R and Marine, JC and Leucci, E}, title = {Non-coding RNAs: the dark side of nuclear-mitochondrial communication.}, journal = {The EMBO journal}, volume = {36}, number = {9}, pages = {1123-1133}, pmid = {28314780}, issn = {1460-2075}, mesh = {Cell Nucleus/*metabolism ; *Gene Expression Regulation ; Mitochondria/*metabolism ; RNA, Untranslated/*metabolism ; }, abstract = {Mitochondria are critical hubs for the integration of several key metabolic processes implicated in cell growth and survival. They originated from bacterial ancestors through endosymbiosis, following the transfer of more than 90% of their endosymbiont genome to the host cell nucleus. Over time, a mutually beneficial symbiotic relationship has been established, which relies on continuous and elaborate signaling mechanisms between this life-essential organelle and its host. The ability of mitochondria to signal their functional state and trigger compensatory and adaptive cellular responses has long been recognized, but the underlying molecular mechanisms involved have remained poorly understood. Recent evidence indicates that non-coding RNAs (ncRNAs) may contribute to the synchronization of a series of essential cellular and mitochondrial biological processes, acting as "messengers" between the nucleus and the mitochondria. Here, we discuss the emerging putative roles of ncRNAs in various bidirectional signaling pathways established between the host cell and its mitochondria, and how the dysregulation of these pathways may lead to aging-related diseases, including cancer, and offer new promising therapeutic avenues.}, }
@article {pmid28304358, year = {2017}, author = {Flaviani, F and Schroeder, DC and Balestreri, C and Schroeder, JL and Moore, K and Paszkiewicz, K and Pfaff, MC and Rybicki, EP}, title = {A Pelagic Microbiome (Viruses to Protists) from a Small Cup of Seawater.}, journal = {Viruses}, volume = {9}, number = {3}, pages = {}, pmid = {28304358}, issn = {1999-4915}, mesh = {Bacteria/*classification/genetics ; Eukaryota/*classification/genetics ; *Microbiota ; Seawater/*microbiology ; Viruses/*classification/genetics ; }, abstract = {The aquatic microbiome is composed of a multi-phylotype community of microbes, ranging from the numerically dominant viruses to the phylogenetically diverse unicellular phytoplankton. They influence key biogeochemical processes and form the base of marine food webs, becoming food for secondary consumers. Due to recent advances in next-generation sequencing, this previously overlooked component of our hydrosphere is starting to reveal its true diversity and biological complexity. We report here that 250 mL of seawater is sufficient to provide a comprehensive description of the microbial diversity in an oceanic environment. We found that there was a dominance of the order Caudovirales (59%), with the family Myoviridae being the most prevalent. The families Phycodnaviridae and Mimiviridae made up the remainder of pelagic double-stranded DNA (dsDNA) virome. Consistent with this analysis, the Cyanobacteria dominate (52%) the prokaryotic diversity. While the dinoflagellates and their endosymbionts, the superphylum Alveolata dominates (92%) the microbial eukaryotic diversity. A total of 834 prokaryotic, 346 eukaryotic and 254 unique virus phylotypes were recorded in this relatively small sample of water. We also provide evidence, through a metagenomic-barcoding comparative analysis, that viruses are the likely source of microbial environmental DNA (meDNA). This study opens the door to a more integrated approach to oceanographic sampling and data analysis.}, }
@article {pmid28303186, year = {2017}, author = {Sazama, EJ and Bosch, MJ and Shouldis, CS and Ouellette, SP and Wesner, JS}, title = {Incidence of Wolbachia in aquatic insects.}, journal = {Ecology and evolution}, volume = {7}, number = {4}, pages = {1165-1169}, pmid = {28303186}, issn = {2045-7758}, abstract = {Wolbachia is a genus of intracellular bacteria typically found within the reproductive systems of insects that manipulates those systems of their hosts. While current estimates of Wolbachia incidence suggest that it infects approximately half of all arthropod species, these estimates are based almost entirely on terrestrial insects. No systematic survey of Wolbachia in aquatic insects has been performed. To estimate Wolbachia incidence among aquatic insect species, we combined field-collected samples from the Missouri River (251 samples from 58 species) with a global database from previously published surveys. The final database contained 5,598 samples of 2,687 total species (228 aquatic and 2,459 terrestrial). We estimate that 52% (95% CrIs: 44%-60%) of aquatic insect species carry Wolbachia, compared to 60% (58%-63%) of terrestrial insects. Among aquatic insects, infected orders included Odonata, Coleoptera, Trichoptera, Ephemeroptera, Diptera, Hemiptera, and Plecoptera. Incidence was highest within aquatic Diptera and Hemiptera (69%), Odonata (50%), and Coleoptera (53%), and was lowest within Ephemeroptera (13%). These results indicate that Wolbachia is common among aquatic insects, but incidence varies widely across orders and is especially uncertain in those orders with low sample sizes such as Ephemeroptera, Plecoptera, and Trichoptera.}, }
@article {pmid28303006, year = {2017}, author = {Aljayyoussi, G and Tyrer, HE and Ford, L and Sjoberg, H and Pionnier, N and Waterhouse, D and Davies, J and Gamble, J and Metuge, H and Cook, DAN and Steven, A and Sharma, R and Guimaraes, AF and Clare, RH and Cassidy, A and Johnston, KL and Myhill, L and Hayward, L and Wanji, S and Turner, JD and Taylor, MJ and Ward, SA}, title = {Short-Course, High-Dose Rifampicin Achieves Wolbachia Depletion Predictive of Curative Outcomes in Preclinical Models of Lymphatic Filariasis and Onchocerciasis.}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {210}, pmid = {28303006}, issn = {2045-2322}, support = {MR/L018756/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Administration, Oral ; Animals ; Anti-Bacterial Agents/*administration &amp; dosage/pharmacology ; Brugia malayi/drug effects/microbiology/physiology ; DNA, Bacterial/drug effects ; Disease Models, Animal ; Elephantiasis, Filarial/*drug therapy/parasitology ; Embryonic Development/drug effects ; Filarioidea/drug effects/*microbiology/physiology ; Humans ; Mice ; Onchocerca volvulus/drug effects/microbiology/physiology ; Onchocerciasis/*drug therapy/parasitology ; Rifampin/*administration &amp; dosage/pharmacology ; Treatment Outcome ; Wolbachia/*drug effects/genetics ; Wuchereria bancrofti/drug effects/microbiology/physiology ; }, abstract = {Lymphatic filariasis (LF) and onchocerciasis are priority neglected tropical diseases targeted for elimination. The only safe drug treatment with substantial curative activity against the filarial nematodes responsible for LF (Brugia malayi, Wuchereria bancrofti) or onchocerciasis (Onchocerca volvulus) is doxycycline. The target of doxycycline is the essential endosymbiont, Wolbachia. Four to six weeks doxycycline therapy achieves >90% depletion of Wolbachia in worm tissues leading to blockade of embryogenesis, adult sterility and premature death 18-24 months post-treatment. Long treatment length and contraindications in children and pregnancy are obstacles to implementing doxycycline as a public health strategy. Here we determine, via preclinical infection models of Brugia malayi or Onchocerca ochengi that elevated exposures of orally-administered rifampicin can lead to Wolbachia depletions from filariae more rapidly than those achieved by doxycycline. Dose escalation of rifampicin achieves >90% Wolbachia depletion in time periods of 7 days in B. malayi and 14 days in O. ochengi. Using pharmacokinetic-pharmacodynamic modelling and mouse-human bridging analysis, we conclude that clinically relevant dose elevations of rifampicin, which have recently been determined as safe in humans, could be administered as short courses to filariasis target populations with potential to reduce anti-Wolbachia curative therapy times to between one and two weeks.}, }
@article {pmid28299861, year = {2017}, author = {Ma, WJ and Schwander, T}, title = {Patterns and mechanisms in instances of endosymbiont-induced parthenogenesis.}, journal = {Journal of evolutionary biology}, volume = {30}, number = {5}, pages = {868-888}, doi = {10.1111/jeb.13069}, pmid = {28299861}, issn = {1420-9101}, mesh = {Animals ; Diploidy ; Female ; Hymenoptera ; *Parthenogenesis ; *Symbiosis ; *Wolbachia/genetics/physiology ; }, abstract = {Female-producing parthenogenesis can be induced by endosymbionts that increase their transmission by manipulating host reproduction. Our literature survey indicates that such endosymbiont-induced parthenogenesis is known or suspected in 124 host species from seven different arthropod taxa, with Wolbachia as the most frequent endosymbiont (in 56-75% of host species). Most host species (81%, 100 out of 124) are characterized by haplo-diploid sex determination, but a strong ascertainment bias likely underestimates the frequency of endosymbiont-induced parthenogenesis in hosts with other sex determination systems. In at least one taxon, hymenopterans, endosymbionts are a significant driver of transitions from sexual to parthenogenetic reproduction, with one-third of lineages being parthenogenetic as a consequence of endosymbiont infection. Endosymbiont-induced parthenogenesis appears to facilitate the maintenance of reproductive polymorphism: at least 50% of species comprise both sexual (uninfected) and parthenogenetic (infected) strains. These strains feature distribution differences similar to the ones documented for lineages with genetically determined parthenogenesis, with endosymbiont-induced parthenogens occurring at higher latitudes than their sexual relatives. Finally, although gamete duplication is often considered as the main mechanism for endosymbiont-induced parthenogenesis, it underlies parthenogenesis in only half of the host species studied thus far. We point out caveats in the methods used to test for endosymbiont-induced parthenogenesis and suggest specific approaches that allow for firm conclusions about the involvement of endosymbionts in the origin of parthenogenesis.}, }
@article {pmid28298352, year = {2017}, author = {Chomicki, G and Renner, SS}, title = {The interactions of ants with their biotic environment.}, journal = {Proceedings. Biological sciences}, volume = {284}, number = {1850}, pages = {}, pmid = {28298352}, issn = {1471-2954}, mesh = {Animals ; *Ants ; Biological Coevolution ; *Fungi ; Hemiptera ; Phylogeny ; *Plants ; *Symbiosis ; }, abstract = {This special feature results from the symposium 'Ants 2016: ant interactions with their biotic environments' held in Munich in May 2016 and deals with the interactions between ants and other insects, plants, microbes and fungi, studied at micro- and macroevolutionary levels with a wide range of approaches, from field ecology to next-generation sequencing, chemical ecology and molecular genetics. In this paper, we review key aspects of these biotic interactions to provide background information for the papers of this special feature After listing the major types of biotic interactions that ants engage in, we present a brief overview of ant/ant communication, ant/plant interactions, ant/fungus symbioses, and recent insights about ants and their endosymbionts. Using a large molecular clock-dated Formicidae phylogeny, we map the evolutionary origins of different ant clades' interactions with plants, fungi and hemiptera. Ants' biotic interactions provide ideal systems to address fundamental ecological and evolutionary questions about mutualism, coevolution, adaptation and animal communication.}, }
@article {pmid28296889, year = {2017}, author = {Cowart, DA and Durand, L and Cambon-Bonavita, MA and Arnaud-Haond, S}, title = {Investigation of bacterial communities within the digestive organs of the hydrothermal vent shrimp Rimicaris exoculata provide insights into holobiont geographic clustering.}, journal = {PloS one}, volume = {12}, number = {3}, pages = {e0172543}, pmid = {28296889}, issn = {1932-6203}, mesh = {Animals ; Crustacea/*microbiology ; Gastrointestinal Tract/*microbiology ; *Geography ; }, abstract = {Prokaryotic communities forming symbiotic relationships with the vent shrimp, Rimicaris exoculata, are well studied components of hydrothermal ecosystems at the Mid-Atlantic Ridge (MAR). Despite the tight link between host and symbiont, the observed lack of spatial genetic structure seen in R. exoculata contrasts with the geographic differentiation detected in specific bacterial ectosymbionts. The geographic clustering of bacterial lineages within a seemingly panmictic host suggests either the presence of finer scale restriction to gene flow not yet detected in the host, horizontal transmission (environmental selection) of its endosymbionts as a consequence of unique vent geochemistry, or vertically transmitted endosymbionts that exhibit genetic differentiation. To identify which hypothesis best fits, we tested whether bacterial assemblages exhibit differentiation across sites or host populations by performing a 16S rRNA metabarcoding survey on R. exoculata digestive prokaryote samples (n = 31) taken from three geochemically distinct vents across MAR: Rainbow, Trans-Atlantic Geotraverse (TAG) and Logatchev. Analysis of communities across two organs (digestive tract, stomach), three molt colors (white, red, black) and three life stages (eggs, juveniles, adults) also provided insights into symbiont transmission mode. Examining both whole communities and operational taxonomic units (OTUs) confirmed the presence of three main epibionts: Epsilonproteobacteria, Mollicutes and Deferribacteres. With these findings, we identified a clear pattern of geographic segregation by vent in OTUs assigned to Epsilonproteobacteria. Additionally, we detected evidence for differentiation among all communities associated to vents and life stages. Overall, results suggest a combination of environmental selection and vertical inheritance of some of the symbiotic lineages.}, }
@article {pmid28291780, year = {2017}, author = {Luck, AN and Slatko, BE and Foster, JM}, title = {Removing the needle from the haystack: Enrichment of Wolbachia endosymbiont transcripts from host nematode RNA by Cappable-seq™.}, journal = {PloS one}, volume = {12}, number = {3}, pages = {e0173186}, pmid = {28291780}, issn = {1932-6203}, mesh = {Animals ; Nematoda/*genetics/*microbiology ; RNA, Messenger/genetics ; RNA, Transfer/genetics ; Sequence Analysis, RNA/*methods ; *Symbiosis ; Wolbachia/*genetics ; }, abstract = {Efficient transcriptomic sequencing of microbial mRNA derived from host-microbe associations is often compromised by the much lower relative abundance of microbial RNA in the mixed total RNA sample. One solution to this problem is to perform extensive sequencing until an acceptable level of transcriptome coverage is obtained. More cost-effective methods include use of prokaryotic and/or eukaryotic rRNA depletion strategies, sometimes in conjunction with depletion of polyadenylated eukaryotic mRNA. Here, we report use of Cappable-seq™ to specifically enrich, in a single step, Wolbachia endobacterial mRNA transcripts from total RNA prepared from the parasitic filarial nematode, Brugia malayi. The obligate Wolbachia endosymbiont is a proven drug target for many human filarial infections, yet the precise nature of its symbiosis with the nematode host is poorly understood. Insightful analysis of the expression levels of Wolbachia genes predicted to underpin the mutualistic association and of known drug target genes at different life cycle stages or in response to drug treatments is typically challenged by low transcriptomic coverage. Cappable-seq resulted in up to ~ 5-fold increase in the number of reads mapping to Wolbachia. On average, coverage of Wolbachia transcripts from B. malayi microfilariae was enriched ~40-fold by Cappable-seq. Additionally, this method has an additional benefit of selectively removing abundant prokaryotic ribosomal RNAs.The deeper microbial transcriptome sequencing afforded by Cappable-seq facilitates more detailed characterization of gene expression levels of pathogens and symbionts present in animal tissues.}, }
@article {pmid28274808, year = {2017}, author = {Stephenson, N and Blaney, A and Clifford, D and Gabriel, M and Wengert, G and Foley, P and Brown, RN and Higley, M and Buckenberger-Mantovani, S and Foley, J}, title = {Diversity of rickettsiae in a rural community in northern California.}, journal = {Ticks and tick-borne diseases}, volume = {8}, number = {4}, pages = {526-531}, doi = {10.1016/j.ttbdis.2017.02.014}, pmid = {28274808}, issn = {1877-9603}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Base Sequence ; California/epidemiology ; *Carnivora ; Cat Diseases/*epidemiology/microbiology ; Cats ; Dog Diseases/*epidemiology/microbiology ; Dogs ; Humans ; Ixodidae/classification ; Prevalence ; Rickettsia/genetics/*isolation &amp; purification ; Rickettsia Infections/*epidemiology/microbiology/*veterinary ; Sequence Alignment/veterinary ; Seroepidemiologic Studies ; }, abstract = {Far northern California forests are highly biodiverse in wildlife reservoirs and arthropod vectors that may propagate rickettsial pathogens in nature. The proximity of small rural communities to these forests puts people and domestic animals at risk of vector-borne infection due to spillover from wildlife. The current study was conducted to document exposure to rickettsial pathogens in people and domestic animals in a rural community, and identify which rickettsiae are present in sylvatic and peri-domestic environments near this community. Blood samples from people, domestic animals (dogs, cats, and horses) and wild carnivores were tested for Rickettsia spp. antibodies and DNA (people and domestic animals only) by serology and real time (RT)-PCR, respectively. Ectoparasites were collected from dogs, wild carnivores and from vegetation by flagging, and tested for Rickettsia spp. DNA by RT-PCR. DNA sequencing of the rickettsial 17kDa protein gene or the ompA gene was used for species identification. Despite a seroprevalence of 3% in people, 42% in dogs, 79% in cats, 33% in gray foxes, and 83% in bobcats, RT-PCR on blood was consistently negative, likely because the sensitivity of this test is low, as Rickettsia spp. do not often circulate in high numbers in the blood. Rickettsia spp. DNA was found in four flea species collected from bobcats and Ctenocephalides felis collected from domestic dogs. All amplicons sequenced from fleas were R. felis. Ixodes pacificus collected by flagging were commonly infected with a Rickettsia sp. endosymbiont. Rickettsia rhipicephali DNA was found in Dermacentor variabilis from dogs, black bears, a gray fox, and a D. occidentalis collected by flagging. Dermacentor variabilis from dogs and black bears also contained R. montanensis DNA. Multiple Rickettsia spp. (including species with zoonotic and pathogenic potential) were found among human biting arthropod vectors of both wild and domestic carnivores and on flags. Knowledge of the diversity of Rickettsia spp. that are present within arthropod vectors to which people and domestic animals are exposed is an essential first step is making an accurate diagnosis and in better understanding the epidemiology of these potential pathogens. Within-host and vector interaction among these species may play a role in spillover into human and domestic animals.}, }
@article {pmid28267749, year = {2017}, author = {Audsley, MD and Ye, YH and McGraw, EA}, title = {The microbiome composition of Aedes aegypti is not critical for Wolbachia-mediated inhibition of dengue virus.}, journal = {PLoS neglected tropical diseases}, volume = {11}, number = {3}, pages = {e0005426}, pmid = {28267749}, issn = {1935-2735}, mesh = {Aedes/*microbiology/*virology ; Animals ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Dengue Virus/*growth &amp; development ; *Gastrointestinal Microbiome ; *Microbial Interactions ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Wolbachia/*growth &amp; development ; }, abstract = {BACKGROUND: Dengue virus (DENV) is primarily vectored by the mosquito Aedes aegypti, and is estimated to cause 390 million human infections annually. A novel method for DENV control involves stable transinfection of Ae. aegypti with the common insect endosymbiont Wolbachia, which mediates an antiviral effect. However, the mechanism by which Wolbachia reduces the susceptibility of Ae. aegypti to DENV is not fully understood. In this study we assessed the potential of resident microbiota, which can play important roles in insect physiology and immune responses, to affect Wolbachia-mediated DENV blocking.<br><br>METHODOLOGY/FINDINGS: The microbiome of Ae. aegypti stably infected with Wolbachia strain wMel was compared to that of Ae. aegypti without Wolbachia, using 16s rDNA profiling. Our results indicate that although Wolbachia affected the relative abundance of several genera, the microbiome of both the Wolbachia-infected and uninfected mosquitoes was dominated by Elizabethkingia and unclassified Enterobacteriaceae. To assess the potential of the resident microbiota to affect the Wolbachia-mediated antiviral effect, we used antibiotic treatment before infection with DENV by blood-meal. In spite of a significant shift in the microbiome composition in response to the antibiotics, we detected no effect of antibiotic treatment on DENV infection rates, or on the DENV load of infected mosquitoes.<br><br>CONCLUSIONS/SIGNIFICANCE: Our findings indicate that stable infection with Wolbachia strain wMel produces few effects on the microbiome of laboratory-reared Ae. aegypti. Moreover, our findings suggest that the microbiome can be significantly altered without affecting the fundamental DENV blocking phenotype in these mosquitoes. Since Ae. aegypti are likely to encounter diverse microbiota in the field, this is a particularly important result in the context of using Wolbachia as a method for DENV control.}, }
@article {pmid28266601, year = {2017}, author = {Wang, XX and Qi, LD and Jiang, R and Du, YZ and Li, YX}, title = {Incomplete removal of Wolbachia with tetracycline has two-edged reproductive effects in the thelytokous wasp Encarsia formosa (Hymenoptera: Aphelinidae).}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {44014}, pmid = {28266601}, issn = {2045-2322}, mesh = {Animals ; Anti-Bacterial Agents/*administration &amp; dosage ; Female ; Fertility/drug effects ; Gene Expression ; Male ; Oocytes/drug effects ; Reproduction ; Tetracycline/*administration &amp; dosage ; Vitellogenins/genetics ; Wasps/*drug effects/*physiology ; Wolbachia/*drug effects/isolation &amp; purification/pathogenicity ; }, abstract = {Wolbachia pipientis are intracellular endosymbionts that induce parthenogenesis in the parasitoid Encarsia formosa. Previous studies that focused on effects of Wolbachia on the wasp usually used tetracycline to remove Wolbachia without concern for the joint influences of tetracycline and Wolbachia. Here we treated the wasps (F0 lines) with tetracycline to produce offspring (F1 lines) which were not fed tetracycline to avoid antibiotic influence. The quantitative data and fluorescence in situ hybridization showed that Wolbachia titers were reduced but not totally removed. The Wolbachia that infected the male offspring were unpredictably detected. Low dose tetracycline enhanced the fertility of 2-day-old F0 wasps after 24 h of treatment; however, compared with controls, the oocyte load of 3- to 6-day-old tetracycline-treated wasps decreased day by day, and tetracycline reduced the longevity of the wasps. The fecundity of controls was significantly higher than that of the treated F1-10 and F1-20 generations. Gene expression of vitellogenin reflected the same trend as that of wasp fecundities in both F0 and F1 lines. Moreover, female offspring proportions of F0 and F1 lines were related to the titer of infected Wolbachia, demonstrating that Wolbachia titer affected the sex determination of E. formosa.}, }
@article {pmid28262718, year = {2017}, author = {Terradas, G and Joubert, DA and McGraw, EA}, title = {The RNAi pathway plays a small part in Wolbachia-mediated blocking of dengue virus in mosquito cells.}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {43847}, pmid = {28262718}, issn = {2045-2322}, mesh = {Aedes/immunology/microbiology/virology ; Animals ; Antibiosis/genetics/immunology ; Cell Line ; Dengue Virus/genetics/*immunology/physiology ; Gene Expression/immunology ; Host-Pathogen Interactions/genetics/immunology ; Mosquito Vectors/*immunology/microbiology/virology ; RNA Interference/*immunology ; Virus Replication/genetics/immunology ; Wolbachia/genetics/*immunology/physiology ; }, abstract = {Wolbachia pipientis is an insect endosymbiont known to limit the replication of viruses including dengue and Zika in their primary mosquito vector, Aedes aegypti. Wolbachia is being released into mosquito populations globally in a bid to control the diseases caused by these viruses. It is theorized that Wolbachia's priming of the insect immune system may confer protection against subsequent viral infection. Other hypotheses posit a role for competition between Wolbachia and viruses for host cellular resources. Using an A. aegypti cell line infected with Wolbachia, we tested the effects of targeting siRNAs against the major innate immune pathways on dengue virus loads. We show that while Wolbachia infection induces genes in the Toll, JAK/STAT and RNAi pathways, only reduced expression of RNAi leads to a rebound of dengue virus loads in Wolbachia-infected cells. The magnitude of the effect explained less than 10% of the total DENV load, demonstrating that blocking must be dependent on other factors in addition to the expression of RNAi. The findings bode well for the long-term stability of blocking given that immunity gene expression would likely be highly plastic and susceptible to rapid evolution.}, }
@article {pmid28261755, year = {2017}, author = {Ramalho, MO and Martins, C and Silva, LM and Martins, VG and Bueno, OC}, title = {Intracellular Symbiotic Bacteria of Camponotus textor, Forel (Hymenoptera, Formicidae).}, journal = {Current microbiology}, volume = {74}, number = {5}, pages = {589-597}, pmid = {28261755}, issn = {1432-0991}, mesh = {Animals ; Ants/*microbiology ; *Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Multilocus Sequence Typing ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Wolbachia/classification/genetics ; }, abstract = {This study focuses on the weaver ant, Camponotus textor, Forel which occurs in some areas of the Brazilian Cerrado and Atlantic Forest, and its symbionts: Blochmannia, an obligate symbiont of Camponotus, and Wolbachia, known for causing reproductive alterations in their hosts. The main goal of this study was to investigate the presence, frequency of occurrence, and diversity of Wolbachia and Blochmannia strains in C. textor colonies. We found high infection rates (100%) and the occurrence of at least two distinct strains of Blochmannia (H_1 or H_7) in the same species. The observed haplotype variation within a single species may result from the high mutation rate of the symbiont. Similarly, the Wolbachia was found in all colonies with different rates of infections and a new strain (supergroup A) was deposited in the MLST database. The diversity found in the present study shows that there is still much to explore to understand about these symbiotic interactions.}, }
@article {pmid28261457, year = {2017}, author = {Soghigian, J and Valsdottir, LR and Livdahl, TP}, title = {A parasite's modification of host behavior reduces predation on its host.}, journal = {Ecology and evolution}, volume = {7}, number = {5}, pages = {1453-1461}, pmid = {28261457}, issn = {2045-7758}, support = {R15 AI092577/AI/NIAID NIH HHS/United States ; }, abstract = {Parasite modification of host behavior is common, and the literature is dominated by demonstrations of enhanced predation on parasitized prey resulting in transmission of parasites to their next host. We present a case in which predation on parasitized prey is reduced. Despite theoretical modeling suggesting that this phenomenon should be common, it has been reported in only a few host-parasite-predator systems. Using a system of gregarine endosymbionts in host mosquitoes, we designed experiments to compare the vulnerability of parasitized and unparasitized mosquito larvae to predation by obligate predatory mosquito larvae and then compared behavioral features known to change in the presence of predatory cues. We exposed Aedes triseriatus larvae to the parasite Ascogregarina barretti and the predator Toxohrynchites rutilus and assessed larval mortality rate under each treatment condition. Further, we assessed behavioral differences in larvae due to infection and predation stimuli by recording larvae and scoring behaviors and positions within microcosms. Infection with gregarines reduced cohort mortality in the presence of the predator, but the parasite did not affect mortality alone. Further, infection by parasites altered behavior such that infected hosts thrashed less frequently than uninfected hosts and were found more frequently on or in a refuge within the microcosm. By reducing predation on their host, gregarines may be acting as mutualists in the presence of predation on their hosts. These results illustrate a higher-order interaction, in which a relationship between a species pair (host-endosymbiont or predator-prey) is altered by the presence of a third species.}, }
@article {pmid28252804, year = {2017}, author = {Parker, BJ and Hrček, J and McLean, AHC and Godfray, HCJ}, title = {Genotype specificity among hosts, pathogens, and beneficial microbes influences the strength of symbiont-mediated protection.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {5}, pages = {1222-1231}, pmid = {28252804}, issn = {1558-5646}, mesh = {Animals ; Aphids/*parasitology ; Fungi/*pathogenicity ; Genetic Variation ; *Genotype ; Phylogeny ; *Symbiosis ; }, abstract = {The microbial symbionts of eukaryotes influence disease resistance in many host-parasite systems. Symbionts show substantial variation in both genotype and phenotype, but it is unclear how natural selection maintains this variation. It is also unknown whether variable symbiont genotypes show specificity with the genotypes of hosts or parasites in natural populations. Genotype by genotype interactions are a necessary condition for coevolution between interacting species. Uncovering the patterns of genetic specificity among hosts, symbionts, and parasites is therefore critical for determining the role that symbionts play in host-parasite coevolution. Here, we show that the strength of protection conferred against a fungal pathogen by a vertically transmitted symbiont of an aphid is influenced by both host-symbiont and symbiont-pathogen genotype by genotype interactions. Further, we show that certain symbiont phylogenetic clades have evolved to provide stronger protection against particular pathogen genotypes. However, we found no evidence of reciprocal adaptation of co-occurring host and symbiont lineages. Our results suggest that genetic variation among symbiont strains may be maintained by antagonistic coevolution with their host and/or their host's parasites.}, }
@article {pmid28250108, year = {2017}, author = {Kitchen, SA and Weis, VM}, title = {The sphingosine rheostat is involved in the cnidarian heat stress response but not necessarily in bleaching.}, journal = {The Journal of experimental biology}, volume = {220}, number = {Pt 9}, pages = {1709-1720}, doi = {10.1242/jeb.153858}, pmid = {28250108}, issn = {1477-9145}, mesh = {Animals ; Dinoflagellida/genetics/physiology ; Dysbiosis/metabolism ; Gene Expression Regulation ; Heat-Shock Response ; *Hot Temperature ; Sea Anemones/enzymology/genetics/*physiology ; Sphingolipids/pharmacology ; Sphingosine/*metabolism ; Symbiosis ; }, abstract = {Sphingolipids play important roles in mitigating cellular heat and oxidative stress by altering membrane fluidity, receptor clustering and gene expression. Accumulation of signaling sphingolipids that comprise the sphingosine rheostat, pro-apoptotic sphingosine (Sph) and pro-survival sphingosine-1-phosphate (S1P) is key to determining cell fate. Reef-building corals and other symbiotic cnidarians living in shallow tropical waters can experience elevated seawater temperature and high UV irradiance, two stressors that are increasing in frequency and severity with climate change. In symbiotic cnidarians, these stressors disrupt the photosynthetic machinery of the endosymbiont and ultimately result in the collapse of the partnership (dysbiosis), known as cnidarian bleaching. In a previous study, exogenously applied sphingolipids altered heat-induced bleaching in the symbiotic anemone Aiptasia pallida, but endogenous regulation of these lipids is unknown. Here, we characterized the role of the rheostat in the cnidarian heat stress response (HSR) and in dysbiosis. Gene expression of rheostat enzymes sphingosine kinase (AP-SPHK) and S1P phosphatase (AP-SGPP), and concentrations of sphingolipids were quantified from anemones incubated at elevated temperatures. We observed a biphasic HSR in A. pallida. At early exposure, rheostat gene expression and lipid levels were suppressed while gene expression of a heat stress biomarker increased and 40% of symbionts were lost. After longer incubations at the highest temperature, AP-SGPP and then Sph levels both increased. These results indicate that the sphingosine rheostat in A. pallida does not participate in initiation of dysbiosis, but instead functions in the chronic response to prolonged heat stress that promotes host survival.}, }
@article {pmid28249568, year = {2017}, author = {Chen, C and Uematsu, K and Linse, K and Sigwart, JD}, title = {By more ways than one: Rapid convergence at hydrothermal vents shown by 3D anatomical reconstruction of Gigantopelta (Mollusca: Neomphalina).}, journal = {BMC evolutionary biology}, volume = {17}, number = {1}, pages = {62}, pmid = {28249568}, issn = {1471-2148}, mesh = {Acclimatization ; Animals ; Bacteria/isolation &amp; purification/ultrastructure ; Ecosystem ; Gastropoda/*anatomy &amp; histology/*classification/genetics/microbiology ; Gills/microbiology ; *Hydrothermal Vents ; Indian Ocean ; Phylogeny ; Symbiosis ; }, abstract = {BACKGROUND: Extreme environments prompt the evolution of characteristic adaptations. Yet questions remain about whether radiations in extreme environments originate from a single lineage that masters a key adaptive pathway, or if the same features can arise in parallel through convergence. Species endemic to deep-sea hydrothermal vents must accommodate high temperature and low pH. The most successful vent species share a constrained pathway to successful energy exploitation: hosting symbionts. The vent-endemic gastropod genus Gigantopelta, from the Southern and Indian Oceans, shares unusual features with a co-occurring peltospirid, the 'scaly-foot gastropod' Chrysomallon squamiferum. Both are unusually large for the clade and share other adaptive features such as a prominent enlarged trophosome-like oesophageal gland, not found in any other vent molluscs.<br><br>RESULTS: Transmission electron microscopy confirmed endosymbiont bacteria in the oesophageal gland of Gigantopelta, as also seen in Chrysomallon. They are the only known members of their phylum in vent ecosystems hosting internal endosymbionts; other vent molluscs host endosymbionts in or on their gills, or in the mantle cavity. A five-gene phylogenetic reconstruction demonstrated that Gigantopelta and Chrysomallon are not phylogenetically sister-taxa, despite their superficial similarity. Both genera have specialist adaptations to accommodate internalised endosymbionts, but with anatomical differences that indicate separate evolutionary origins. Hosting endosymbionts in an internal organ within the host means that all resources required by the bacteria must be supplied by the animal, rather than directly by the vent fluid. Unlike Chrysomallon, which has an enlarged oesophageal gland throughout post-settlement life, the oesophageal gland in Gigantopelta is proportionally much smaller in juveniles and the animals likely undergo a trophic shift during ontogeny. The circulatory system is hypertrophied in both but the overall size is smaller in Gigantopelta. In contrast with Chrysomallon, Gigantopelta possesses true ganglia and is gonochoristic.<br><br>CONCLUSIONS: Key anatomical differences between Gigantopelta and Chrysomallon demonstrate these two genera acquired a similar way of life through independent and convergent adaptive pathways. What appear to be the holobiont's adaptations to an extreme environment, are driven by optimising bacteria's access to vent nutrients. By comparing Gigantopelta and Chrysomallon, we show that metazoans are capable of rapidly and repeatedly evolving equivalent anatomical adaptations and close-knit relationships with chemoautotrophic bacteria, achieving the same end-product through parallel evolutionary trajectories.}, }
@article {pmid28246645, year = {2017}, author = {Bongaerts, P and Riginos, C and Brunner, R and Englebert, N and Smith, SR and Hoegh-Guldberg, O}, title = {Deep reefs are not universal refuges: Reseeding potential varies among coral species.}, journal = {Science advances}, volume = {3}, number = {2}, pages = {e1602373}, pmid = {28246645}, issn = {2375-2548}, mesh = {Animals ; *Anthozoa/classification/physiology ; *Coral Reefs ; *Models, Biological ; }, abstract = {Deep coral reefs (that is, mesophotic coral ecosystems) can act as refuges against major disturbances affecting shallow reefs. It has been proposed that, through the provision of coral propagules, such deep refuges may aid in shallow reef recovery; however, this "reseeding" hypothesis remains largely untested. We conducted a genome-wide assessment of two scleractinian coral species with contrasting reproductive modes, to assess the potential for connectivity between mesophotic (40 m) and shallow (12 m) depths on an isolated reef system in the Western Atlantic (Bermuda). To overcome the pervasive issue of endosymbiont contamination associated with de novo sequencing of corals, we used a novel subtraction reference approach. We have demonstrated that strong depth-associated selection has led to genome-wide divergence in the brooding species Agaricia fragilis (with divergence by depth exceeding divergence by location). Despite introgression from shallow into deep populations, a lack of first-generation migrants indicates that effective connectivity over ecological time scales is extremely limited for this species and thus precludes reseeding of shallow reefs from deep refuges. In contrast, no genetic structuring between depths (or locations) was observed for the broadcasting species Stephanocoenia intersepta, indicating substantial potential for vertical connectivity. Our findings demonstrate that vertical connectivity within the same reef system can differ greatly between species and that the reseeding potential of deep reefs in Bermuda may apply to only a small number of scleractinian species. Overall, we argue that the "deep reef refuge hypothesis" holds for individual coral species during episodic disturbances but should not be assumed as a broader ecosystem-wide phenomenon.}, }
@article {pmid28245269, year = {2017}, author = {Yashavantha Rao, HC and Rakshith, D and Harini, BP and Gurudatt, DM and Satish, S}, title = {Chemogenomics driven discovery of endogenous polyketide anti-infective compounds from endosymbiotic Emericella variecolor CLB38 and their RNA secondary structure analysis.}, journal = {PloS one}, volume = {12}, number = {2}, pages = {e0172848}, pmid = {28245269}, issn = {1932-6203}, mesh = {Anti-Infective Agents/chemistry/pharmacology ; Combretaceae/*microbiology ; DNA, Ribosomal/genetics ; Emericella/*chemistry/genetics/*physiology ; Isoindoles/chemistry/pharmacology ; Microbial Sensitivity Tests ; Polyketides/chemistry/pharmacology ; RNA, Fungal/genetics ; Symbiosis ; }, abstract = {In the postgenomic era, a new strategy for chemical dereplication of polyketide anti-infective drugs requires novel genomics and chromatographic strategies. An endosymbiotic fungal strain CLB38 was isolated from the root tissue of Combretum latifolium Blume (Combretaceae) which was collected from the Western Ghats of India. The isolate CLB38 was then identified as Emericella variecolor by its characteristic stellate ascospores culture morphology and molecular analysis of ITS nuclear rDNA and intervening 5.8S rRNA gene sequence. ITS2 RNA secondary structure modeling clearly distinguished fungal endosymbiont E. variecolor CLB38 with other lifestyles in the same monophyletic clade. Ethyl acetate fraction of CLB38 explored a broad spectrum of antimicrobial activity against multidrug resistant pathogens. Biosynthetic PKS type-I gene and chromatographic approach afford two polyketide antimicrobial compounds which identified as evariquinone and isoindolones derivative emerimidine A. MIC of purified compounds against test microorganisms ranged between 3.12 μg/ml and 12.5 μg/ml. This research highlights the utility of E. variecolor CLB38 as an anticipate source for anti-infective polyketide metabolites evariquinone and emerimidine A to combat multidrug resistant microorganisms. Here we demonstrates a chemogenomics strategy via the feasibility of PKS type-I gene and chromatographic approach as a proficient method for the rapid prediction and discovery of new polyketides compounds from fungal endosymbionts.}, }
@article {pmid28235879, year = {2017}, author = {Erban, T and Ledvinka, O and Nesvorna, M and Hubert, J}, title = {Experimental Manipulation Shows a Greater Influence of Population than Dietary Perturbation on the Microbiome of Tyrophagus putrescentiae.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {9}, pages = {}, pmid = {28235879}, issn = {1098-5336}, mesh = {Acaridae/*microbiology ; Animals ; Bacteria/*classification/*genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Diet/*methods ; Feeding Behavior ; *Gastrointestinal Microbiome ; RNA, Ribosomal, 16S/genetics ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; }, abstract = {Tyrophagus putrescentiae is inhabited by bacteria that differ among mite populations (strains) and diets. Here, we investigated how the microbiome and fitness of Tputrescentiae are altered by dietary perturbations and mite populations. Four T. putrescentiae populations, referred to as dog, Koppert, laboratory, and Phillips, underwent a perturbation, i.e., a dietary switch from a rearing diet to two experimental diets. The microbiome was investigated by sequencing the V1-V3 portion of the 16S rRNA gene, and selected bacterial taxa were quantified by quantitative PCR (qPCR) using group/taxon-specific primers. The parameters observed were the changes in mite population growth and nutritional status, i.e., the total glycogen, lipid, saccharide, and protein contents in mites. The effect of diet perturbation on the variability of the microbiome composition and population growth was lower than the effect induced by mite population. In contrast, the diet perturbation showed a greater effect on nutritional status of mites than the mite population. The endosymbionts exhibited high variations among T. putrescentiae populations, including Cardinium in the laboratory population, Blattabacterium-like bacteria in the dog population, and Wolbachia in the dog and Phillips populations. Solitalea-like and Bartonella-like bacteria were present in the dog, Koppert, and Phillips populations in different proportions. The T. putrescentiae microbiome is dynamic and varies based on both the mite population and perturbation; however, the mites remain characterized by robust bacterial communities. Bacterial endosymbionts were found in all populations but represented a dominant portion of the microbiome in only some populations.IMPORTANCE We addressed the question of whether population origin or perturbation exerts a more significant influence on the bacterial community of the stored product mite Tyrophagus putrescentiae The microbiomes of four populations of T. putrescentiae insects subjected to diet perturbation were compared. Based on our results, the bacterial community was more affected by the mite population than by diet perturbation. This result can be interpreted as indicating high stability of the putative intracellular symbionts in response to dietary perturbation. The changes in the absolute and relative numbers of Wolbachia, Blattabacterium-like, Solitalea-like, and Cardinium bacteria in the T. putrescentiae populations can also be caused by neutral processes other than perturbation. When nutritional status is considered, the effect of population appeared less important than the perturbation. We hypothesize that differences in the proportions of the endosymbiotic bacteria result in changes in mite population growth.}, }
@article {pmid28219758, year = {2017}, author = {Reynolds, NK and Smith, ME and Tretter, ED and Gause, J and Heeney, D and Cafaro, MJ and Smith, JF and Novak, SJ and Bourland, WA and White, MM}, title = {Resolving relationships at the animal-fungal divergence: A molecular phylogenetic study of the protist trichomycetes (Ichthyosporea, Eccrinida).}, journal = {Molecular phylogenetics and evolution}, volume = {109}, number = {}, pages = {447-464}, doi = {10.1016/j.ympev.2017.02.007}, pmid = {28219758}, issn = {1095-9513}, mesh = {Animals ; Bayes Theorem ; *Biological Evolution ; DNA, Ribosomal ; Evolution, Molecular ; Fungi/*classification/genetics ; Mesomycetozoea/*classification/genetics ; Phylogeny ; }, abstract = {Trichomycetes is a group of microorganisms that was considered a class of fungi comprising four orders of commensal, gut-dwelling endosymbionts obligately associated with arthropods. Since molecular phylogenies revealed two of those orders (Amoebidiales and Eccrinales="protist trichos") to be closely related to members of the protist class Ichthyosporea (=Mesomycetozoea), trichomycetes have been considered an ecological association of both early-diverging fungi and protists. Understanding of the taxonomy, evolution, and diversity of the protist trichos is lacking largely due to the difficulties inherent in species collection that have contributed to undersampling and understudy. The most recent classification divides the protist trichos between two families, Amoebidiidae and Eccrinidae (suborder Trichomycina, order Eccrinida). However, there is no comprehensive molecular phylogeny available for this group and major questions about the systematics of protist trichos remain unanswered. Therefore, we generated 18S and 28S rDNA sequences for 106 protist tricho samples and combined them with publicly available Eccrinida sequences for phylogenetic analyses. We also sequenced a conserved protein-coding gene (heat-shock 70 protein) to obtain a multigene data set. We conducted ancestral state reconstruction (ASR) and Bayesian tip-association significance test (BaTS) analyses by mapping six morphological and ecological characters onto the resulting phylogenetic trees. Our results demonstrate: (1) several ecological and morphological character states (habitat, host type, host stage at time of infestation, location within host, spore production, and growth form) are significantly correlated with the phylogeny, and (2) two additional protist tricho families should be incorporated into the taxonomy to reflect phylogenetic relationships. Our data suggest that an integrated strategy that combines morphological, ecological, and molecular characters is needed to further resolve and clarify the systematics of the Eccrinida.}, }
@article {pmid28218694, year = {2017}, author = {Matobole, RM and van Zyl, LJ and Parker-Nance, S and Davies-Coleman, MT and Trindade, M}, title = {Antibacterial Activities of Bacteria Isolated from the Marine Sponges Isodictya compressa and Higginsia bidentifera Collected from Algoa Bay, South Africa.}, journal = {Marine drugs}, volume = {15}, number = {2}, pages = {}, pmid = {28218694}, issn = {1660-3397}, mesh = {Animals ; Anti-Bacterial Agents/isolation &amp; purification/*pharmacology ; Bacteria/*chemistry/genetics/isolation &amp; purification ; Base Sequence ; Bays ; Biodiversity ; Biological Products/isolation &amp; purification/*pharmacology ; Drug Resistance, Multiple, Bacterial/drug effects ; Escherichia coli/*drug effects ; Porifera/*microbiology ; South Africa ; Symbiosis ; }, abstract = {Due to the rise in multi-drug resistant pathogens and other diseases, there is renewed interest in marine sponge endosymbionts as a rich source of natural products (NPs). The South African marine environment is rich in marine biota that remains largely unexplored and may represent an important source for the discovery of novel NPs. We first investigated the bacterial diversity associated with five South African marine sponges, whose microbial populations had not previously been investigated, and select the two sponges (Isodictya compressa and Higginsia bidentifera) with highest species richness to culture bacteria. By employing 33 different growth conditions 415 sponge-associated bacterial isolates were cultured and screened for antibacterial activity. Thirty-five isolates showed antibacterial activity, twelve of which exhibited activity against the multi-drug resistant Escherichia coli 1699, implying that some of the bioactive compounds could be novel. Genome sequencing of two of these isolates confirmed that they harbour uncharacterized biosynthetic pathways that may encode novel chemical structures.}, }
@article {pmid28216337, year = {2017}, author = {Détrée, C and Lallier, FH and Tanguy, A and Mary, J}, title = {Identification and gene expression of multiple peptidoglycan recognition proteins (PGRPs) in the deep-sea mussel Bathymodiolus azoricus, involvement in symbiosis?.}, journal = {Comparative biochemistry and physiology. Part B, Biochemistry &amp; molecular biology}, volume = {207}, number = {}, pages = {1-8}, doi = {10.1016/j.cbpb.2017.02.002}, pmid = {28216337}, issn = {1879-1107}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/chemistry/growth &amp; development ; Bivalvia/classification/*genetics/immunology/microbiology ; Carrier Proteins/*genetics/immunology ; Cell Wall/chemistry/physiology ; Gene Expression ; Gills/immunology/microbiology ; Hydrothermal Vents ; Immunity, Innate ; Peptidoglycan/chemistry/*immunology ; *Phylogeny ; Protein Isoforms/genetics/immunology ; Protein Sorting Signals/genetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; *Symbiosis ; }, abstract = {The relationship between the deep-sea mussel Bathymodiolus azoricus and its thiotrophic (SOX) and methanotrophic (MOX) symbionts has been ecologically and functionally well studied. Endosymbiosis is common in deep-sea hydrothermal vent fauna, yet little is known about the molecular mechanisms underlying the regulation of interactions between host and symbionts. In this study we focused on a group of pattern recognition receptors (PRR), called PGRPs that are able to recognize the peptidoglycan of bacterial cell wall. We first characterised the different PGRPs isoforms in B. azoricus gills and identified five paralogs. Among them two displayed a signal peptide. Then, specific probes designed for each paralog were used to perform real-time PCR quantification in gills of individuals showing various bacterial content as a result of in situ experimental procedures. Overall we found a decrease of PGRPs expression when symbionts amount decreases, suggesting an implication of PGRPs in the regulation of symbionts in B. azoricus gills. We therefore hypothesize that secreted proteins could act as cooperation signals to induce colonisation of symbiotic tissue while non-secreted proteins may regulate the density of endosymbionts within the gill tissue.}, }
@article {pmid28209133, year = {2017}, author = {Gendreau, KL and Haney, RA and Schwager, EE and Wierschin, T and Stanke, M and Richards, S and Garb, JE}, title = {House spider genome uncovers evolutionary shifts in the diversity and expression of black widow venom proteins associated with extreme toxicity.}, journal = {BMC genomics}, volume = {18}, number = {1}, pages = {178}, pmid = {28209133}, issn = {1471-2164}, support = {R15 GM097714/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Black Widow Spider ; Coxiellaceae/physiology ; *Evolution, Molecular ; Female ; *Gene Expression Profiling ; *Genetic Variation ; *Genomics ; Insect Proteins/chemistry/genetics/metabolism/*toxicity ; Male ; Protein Domains ; Sex Characteristics ; Spider Venoms/*genetics ; Symbiosis ; }, abstract = {BACKGROUND: Black widow spiders are infamous for their neurotoxic venom, which can cause extreme and long-lasting pain. This unusual venom is dominated by latrotoxins and latrodectins, two protein families virtually unknown outside of the black widow genus Latrodectus, that are difficult to study given the paucity of spider genomes. Using tissue-, sex- and stage-specific expression data, we analyzed the recently sequenced genome of the house spider (Parasteatoda tepidariorum), a close relative of black widows, to investigate latrotoxin and latrodectin diversity, expression and evolution.<br><br>RESULTS: We discovered at least 47 latrotoxin genes in the house spider genome, many of which are tandem-arrayed. Latrotoxins vary extensively in predicted structural domains and expression, implying their significant functional diversification. Phylogenetic analyses show latrotoxins have substantially duplicated after the Latrodectus/Parasteatoda split and that they are also related to proteins found in endosymbiotic bacteria. Latrodectin genes are less numerous than latrotoxins, but analyses show their recruitment for venom function from neuropeptide hormone genes following duplication, inversion and domain truncation. While latrodectins and other peptides are highly expressed in house spider and black widow venom glands, latrotoxins account for a far smaller percentage of house spider venom gland expression.<br><br>CONCLUSIONS: The house spider genome sequence provides novel insights into the evolution of venom toxins once considered unique to black widows. Our results greatly expand the size of the latrotoxin gene family, reinforce its narrow phylogenetic distribution, and provide additional evidence for the lateral transfer of latrotoxins between spiders and bacterial endosymbionts. Moreover, we strengthen the evidence for the evolution of latrodectin venom genes from the ecdysozoan Ion Transport Peptide (ITP)/Crustacean Hyperglycemic Hormone (CHH) neuropeptide superfamily. The lower expression of latrotoxins in house spiders relative to black widows, along with the absence of a vertebrate-targeting &#x3b1;-latrotoxin gene in the house spider genome, may account for the extreme potency of black widow venom.}, }
@article {pmid28198810, year = {2017}, author = {Wan, PJ and Tang, YH and Yuan, SY and He, JC and Wang, WX and Lai, FX and Fu, Q}, title = {Reference genes for quantitative real-time PCR analysis in symbiont Entomomyces delphacidicola of Nilaparvata lugens (Stål).}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {42206}, pmid = {28198810}, issn = {2045-2322}, mesh = {Amino Acids/metabolism ; Animals ; Ascomycota/*genetics/metabolism ; Cloning, Molecular ; Fungal Proteins/antagonists &amp; inhibitors/*genetics/metabolism ; *Gene Expression Regulation, Fungal ; Genes, Essential ; *Genes, Fungal ; Hemiptera/growth &amp; development/metabolism/*microbiology/pathogenicity ; Life Cycle Stages/*physiology ; Oryza/parasitology ; Polymerase Chain Reaction/standards ; RNA, Small Interfering/genetics/metabolism ; Symbiosis/genetics ; }, abstract = {Nilaparvata lugens (Stål) (Hemiptera: Delphacidae) is a major rice pest that harbors an endosymbiont ascomycete fungus, Entomomyces delphacidicola str. NLU (also known as yeast-like symbiont, YLS). Driving by demand of novel population management tactics (e.g. RNAi), the importance of YLS has been studied and revealed, which greatly boosts the interest of molecular level studies related to YLS. The current study focuses on reference genes for RT-qPCR studies related to YLS. Eight previously unreported YLS genes were cloned, and their expressions were evaluated for N. lugens samples of different developmental stages and sexes, and under different nutritional conditions and temperatures. Expression stabilities were analyzed by BestKeeper, geNorm, NormFinder, ΔCt method and RefFinder. Furthermore, the selected reference genes for RT-qPCR of YLS genes were validated using targeted YLS genes that respond to different nutritional conditions (amino acid deprivation) and RNAi. The results suggest that ylsRPS15p/ylsACT are the most suitable reference genes for temporal gene expression profiling, while ylsTUB/ylsACT and ylsRPS15e/ylsGADPH are the most suitable reference gene choices for evaluating nutrition and temperature effects. Validation studies demonstrated the advantage of using endogenous YLS reference genes for YLS studies.}, }
@article {pmid28189637, year = {2017}, author = {Sieber, KB and Bromley, RE and Dunning Hotopp, JC}, title = {Lateral gene transfer between prokaryotes and eukaryotes.}, journal = {Experimental cell research}, volume = {358}, number = {2}, pages = {421-426}, pmid = {28189637}, issn = {1090-2422}, support = {DP2 OD007372/OD/NIH HHS/United States ; R01 CA206188/CA/NCI NIH HHS/United States ; T32 DK067872/DK/NIDDK NIH HHS/United States ; 1-R01-CA206188/CA/NCI NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics ; Eukaryota/*genetics ; *Evolution, Molecular ; Gene Transfer, Horizontal/*genetics/physiology ; Humans ; Mitochondria/metabolism ; Prokaryotic Cells/*cytology ; }, abstract = {Lateral gene transfer (LGT) is an all-encompassing term for the movement of DNA between diverse organisms. LGT is synonymous with horizontal gene transfer, and the terms are used interchangeably throughout the scientific literature. While LGT has been recognized within the bacteria domain of life for decades, inter-domain LGTs are being increasingly described. LGTs between bacteria and complex multicellular organisms are of interest because they challenge the long-held dogma that such transfers could only occur in closely-related, single-celled organisms. Scientists will continue to challenge our understanding of LGT as we sequence more, diverse organisms, as we sequence more endosymbiont-colonized arthropods, and as we continue to appreciate LGT events, both young and old.}, }
@article {pmid28188662, year = {2017}, author = {Thornhill, DJ and Howells, EJ and Wham, DC and Steury, TD and Santos, SR}, title = {Population genetics of reef coral endosymbionts (Symbiodinium, Dinophyceae).}, journal = {Molecular ecology}, volume = {26}, number = {10}, pages = {2640-2659}, doi = {10.1111/mec.14055}, pmid = {28188662}, issn = {1365-294X}, mesh = {Animals ; *Anthozoa ; Climate Change ; Coral Reefs ; Dinoflagellida/*growth &amp; development ; *Genetics, Population ; *Phylogeny ; *Symbiosis ; }, abstract = {Symbiodinium is a diverse genus of unicellular dinoflagellate symbionts associating with various marine protists and invertebrates. Although the broadscale diversity and phylogenetics of the Symbiodinium complex is well established, there have been surprisingly few data on fine-scale population structure and biogeography of these dinoflagellates. Yet population-level processes contribute strongly to the biology of Symbiodinium, including how anthropogenic-driven global climate change impacts these symbionts and their host associations. Here, we present a synthesis of population-level characteristics for Symbiodinium, with an emphasis on how phylogenetic affinities, dynamics within and among host individuals, and a propensity towards clonality shape patterns on and across reefs. Major inferences include the following: (i) Symbiodinium populations within individual hosts are comprised mainly of cells belonging to a single or few genetic clones. (ii) Symbiont populations exhibit a mixed mode of reproduction, wherein at least one sexual recombination event occurs in the genealogy between most genotypes, but clonal propagation predominates overall. (iii) Mutualistic Symbiodinium do not perpetually persist outside their hosts, instead undergoing turnover and replacement via the continuous shedding of viable clonal cells from host individuals. (iv) Symbiont populations living in the same host, but on different reefs, are often genetically subdivided, suggesting low connectivity, adaptation to local conditions, or prolific asexual reproduction and low effective population sizes leading to disproportionate success within and among hosts. Overall, this synthesis forms a basis for future investigations of coral symbiosis ecology and evolution as well as delimitation of species boundaries in Symbiodinium and other eukaryotic microorganisms.}, }
@article {pmid28181581, year = {2017}, author = {Lin, Z and Chen, M and Dong, X and Zheng, X and Huang, H and Xu, X and Chen, J}, title = {Transcriptome profiling of Galaxea fascicularis and its endosymbiont Symbiodinium reveals chronic eutrophication tolerance pathways and metabolic mutualism between partners.}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {42100}, pmid = {28181581}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/genetics/*growth &amp; development/*parasitology ; Aquatic Organisms/genetics/growth &amp; development/parasitology ; China ; Dinoflagellida/genetics/*growth &amp; development ; *Eutrophication ; *Gene Expression Profiling ; *Metabolic Networks and Pathways ; Stress, Physiological ; *Symbiosis ; }, abstract = {In the South China Sea, coastal eutrophication in the Beibu Gulf has seriously threatened reef habitats by subjecting corals to chronic physiological stress. To determine how coral holobionts may tolerate such conditions, we examined the transcriptomes of healthy colonies of the galaxy coral Galaxea fascicularis and its endosymbiont Symbiodinium from two reef sites experiencing pristine or eutrophied nutrient regimes. We identified 236 and 205 genes that were differentially expressed in eutrophied hosts and symbionts, respectively. Both gene sets included pathways related to stress responses and metabolic interactions. An analysis of genes originating from each partner revealed striking metabolic integration with respect to vitamins, cofactors, amino acids, fatty acids, and secondary metabolite biosynthesis. The expression levels of these genes supported the existence of a continuum of mutualism in this coral-algal symbiosis. Additionally, large sets of transcription factors, cell signal transduction molecules, biomineralization components, and galaxin-related proteins were expanded in G. fascicularis relative to other coral species.}, }
@article {pmid28181227, year = {2017}, author = {Nguyen, DT and Morrow, JL and Spooner-Hart, RN and Riegler, M}, title = {Independent cytoplasmic incompatibility induced by Cardinium and Wolbachia maintains endosymbiont coinfections in haplodiploid thrips populations.}, journal = {Evolution; international journal of organic evolution}, volume = {71}, number = {4}, pages = {995-1008}, doi = {10.1111/evo.13197}, pmid = {28181227}, issn = {1558-5646}, mesh = {Animals ; Bacteroidetes/*physiology ; Reproduction ; *Symbiosis ; Thysanoptera/*microbiology ; Wolbachia/*physiology ; }, abstract = {Cardinium and Wolbachia are common maternally inherited reproductive parasites that can coinfect arthropods, yet interactions between both bacterial endosymbionts are rarely studied. For the first time, we report their independent expression of complete cytoplasmic incompatibility (CI) in a coinfected host, and CI in a species of the haplodiploid insect order Thysanoptera. In Pezothrips kellyanus, Cardinium-induced CI resulted in a combination of male development (MD) and embryonic female mortality (FM) of fertilized eggs. In contrast, Wolbachia-induced CI resulted in FM together with postembryonic mortality not previously reported as a CI outcome. Both endosymbionts appeared to not influence fecundity but virgins produced more offspring than mated females. In coinfected individuals, Wolbachia density was higher than Cardinium. Wolbachia removal did not impact Cardinium density, suggesting a lack of competition within hosts. Maternal transmission was complete for Wolbachia and high for Cardinium. Our data support theoretical predictions and empirical detection of high endosymbiont prevalence in field populations of the native range of this pest thrips. However, previous findings of more frequent loss of Wolbachia than Cardinium, particularly in field populations of the host's invasive range, suggest that genetic diversity or varying environmental factors between field populations also play a role in shaping host-endosymbiont dynamics.}, }
@article {pmid28175279, year = {2017}, author = {Salomaki, ED and Lane, CE}, title = {Red Algal Mitochondrial Genomes Are More Complete than Previously Reported.}, journal = {Genome biology and evolution}, volume = {9}, number = {1}, pages = {48-63}, pmid = {28175279}, issn = {1759-6653}, mesh = {Evolution, Molecular ; Genes, Mitochondrial ; *Genome, Mitochondrial ; Molecular Sequence Annotation ; Rhodophyta/*classification/cytology/*genetics ; }, abstract = {The enslavement of an alpha-proteobacterial endosymbiont by the last common eukaryotic ancestor resulted in large-scale gene transfer of endosymbiont genes to the host nucleus as the endosymbiont transitioned into the mitochondrion. Mitochondrial genomes have experienced widespread gene loss and genome reduction within eukaryotes and DNA sequencing has revealed that most of these gene losses occurred early in eukaryotic lineage diversification. On a broad scale, more recent modifications to organelle genomes appear to be conserved and phylogenetically informative. The first red algal mitochondrial genome was sequenced more than 20 years ago, and an additional 29 Florideophyceae mitochondria have been added over the past decade. A total of 32 genes have been described to have been missing or considered non-functional pseudogenes from these Florideophyceae mitochondria. These losses have been attributed to endosymbiotic gene transfer or the evolution of a parasitic life strategy. Here we sequenced the mitochondrial genomes from the red algal parasite Choreocolax polysiphoniae and its host Vertebrata lanosa and found them to be complete and conserved in structure with other Florideophyceae mitochondria. This result led us to resequence the previously published parasite Gracilariophila oryzoides and its host Gracilariopsis andersonii, as well as reevaluate reported gene losses from published Florideophyceae mitochondria. Multiple independent losses of rpl20 and a single loss of rps11 can be verified. However by reannotating published data and resequencing specimens when possible, we were able to identify the majority of genes that have been reported as lost or pseudogenes from Florideophyceae mitochondria.}, }
@article {pmid28174567, year = {2017}, author = {Wangpraseurt, D and Holm, JB and Larkum, AW and Pernice, M and Ralph, PJ and Suggett, DJ and Kühl, M}, title = {In vivo Microscale Measurements of Light and Photosynthesis during Coral Bleaching: Evidence for the Optical Feedback Loop?.}, journal = {Frontiers in microbiology}, volume = {8}, number = {}, pages = {59}, pmid = {28174567}, issn = {1664-302X}, abstract = {Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment. We created tissue areas with different densities of Symbiodinium cells in order to understand the optical properties and light microenvironment of corals during bleaching. Our results showed that in bleached Pocillopora damicornis corals, Symbiodinium light exposure was up to fivefold enhanced relative to healthy corals, and the relationship between symbiont loss and light enhancement was well-described by a power-law function. Cell-specific rates of Symbiodinium gross photosynthesis and light respiration were enhanced in bleached P. damicornis compared to healthy corals, while areal rates of net photosynthesis decreased. Symbiodinium light exposure in Favites sp. revealed the presence of low light microniches in bleached coral tissues, suggesting that light scattering in thick coral tissues can enable photoprotection of cryptic symbionts. Our study provides evidence for the acceleration of in vivo light exposure during coral bleaching but this optical feedback mechanism differs between coral hosts. Enhanced photosynthesis in relation to accelerating light exposure shows that coral microscale optics exerts a key role on coral photophysiology and the subsequent degree of radiative stress during coral bleaching.}, }
@article {pmid28150358, year = {2017}, author = {Sibbald, SJ and Cenci, U and Colp, M and Eglit, Y and O'Kelly, CJ and Archibald, JM}, title = {Diversity and Evolution of Paramoeba spp. and their Kinetoplastid Endosymbionts.}, journal = {The Journal of eukaryotic microbiology}, volume = {64}, number = {5}, pages = {598-607}, doi = {10.1111/jeu.12394}, pmid = {28150358}, issn = {1550-7408}, support = {MOP&#x2010;115141//CIHR/Canada ; }, mesh = {Amoebozoa/*classification/isolation &amp; purification/parasitology ; Animals ; DNA, Protozoan/genetics ; DNA, Ribosomal/genetics ; Evolution, Molecular ; Kinetoplastida/*classification/genetics/isolation &amp; purification ; Phylogeny ; RNA, Ribosomal, 18S/*genetics ; Sea Urchins/*parasitology ; Sequence Analysis, DNA/methods ; Symbiosis ; }, abstract = {Members of the genus Paramoeba (including Neoparamoeba) (Amoebozoa) are single-celled eukaryotes of economic and ecological importance because of their association with disease in a variety of marine animals including fish, sea urchins, and lobster. Interestingly, they harbor a eukaryotic endosymbiont of kinetoplastid ancestry, Perkinsela sp. To investigate the complex relationship between Paramoeba spp. and Perkinsela sp., as well as the relationships between different Paramoeba species, molecular data was obtained for four novel isolates. We also acquired new data from the urchin pathogen P. invadens. Comprehensive molecular phylogenetic analyses were carried out using 33 newly obtained 18S rDNA sequences from the host amoebae and 16 new 18S rDNA sequences from their corresponding Perkinsela sp., together with all publicly available 18S molecular data. Intra-isolate 18S rDNA nucleotide diversity was found to be surprisingly high within the various species of Paramoeba, but relatively low within their Perkinsela sp. endosymbionts. 18S rDNA phylogenies and ParaFit co-evolution analysis revealed a high degree of congruence between the Paramoeba and Perkinsela sp. tree topologies, strongly suggesting that a single endosymbiotic event occurred in the common ancestor of known Paramoeba species, and that the endosymbionts have been inherited vertically ever since.}, }
@article {pmid28134067, year = {2017}, author = {Ma, R and Fan, X and Yin, F and Ni, B and Gu, F}, title = {Ultrastructural features of the tomont of Cryptocaryon irritans (Ciliophora: Prostomatea), a parasitic ciliate of marine fishes.}, journal = {Parasitology}, volume = {144}, number = {6}, pages = {720-729}, doi = {10.1017/S0031182016002651}, pmid = {28134067}, issn = {1469-8161}, mesh = {Animals ; China ; Cilia/ultrastructure ; Ciliophora/growth &amp; development/*ultrastructure ; Ciliophora Infections/parasitology/*veterinary ; Fish Diseases/*parasitology ; Fisheries ; Fishes ; Microscopy, Electron, Scanning/veterinary ; Microscopy, Electron, Transmission/veterinary ; Symbiosis ; }, abstract = {Numerous studies have been conducted on the cellular morphology of Cryptocaryon irritans. However, details regarding the tomont stage of its life cycle remain lacking. In this study, we investigated the morphology of the tomont stage throughout encystment and cell division using light and electron microscopy. Results showed that there was no secretion of encystation-specific secretory vesicles or extrusomes during formation of the cyst wall. Instead, the synthesis and construction of the C. irritans cyst wall materials may involve molecular events at the pellicle. The somatic cilia and the cytostome were present during encystment and covered by the newly formed cyst wall. New somatic cilia were continuously created between old cilia and showed various lengths during cell division, a process that was similar to morphogenesis in many free-living ciliates. During cell division inside the tomont, dividing daughter cells formed temporary cell chains with no oral primordia before separating from each other into dissociative tomite precursors. The process of cell division may not be accompanied by stomatogenesis, and new oral primordia in offspring cells likely formed before the dividing cell chains split into dissociative spherical tomites. Mitochondrial autophagy was observed in encysting C. irritans cells. Numerous endosymbionts and Golgi structures were observed in the tomont cytoplasm. Cellular metabolic activity in the C. irritans tomont was quite high, with large amounts of materials or cellular organelles potentially being synthesized and prepared for the following infective theront stage.}, }
@article {pmid28127053, year = {2017}, author = {Pekas, A and Palevsky, E and Sumner, JC and Perotti, MA and Nesvorna, M and Hubert, J}, title = {Comparison of bacterial microbiota of the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae) and its factitious prey Tyrophagus putrescentiae (Acari: Acaridae).}, journal = {Scientific reports}, volume = {7}, number = {1}, pages = {2}, pmid = {28127053}, issn = {2045-2322}, mesh = {Acari/*microbiology ; Animals ; Bacteria/*classification/*genetics ; Metagenomics ; *Microbiota ; Symbiosis ; }, abstract = {Neoseiulus cucumeris is a predatory mite used for biological control of arthropod pests. Mass-reared predators are fed with factitious prey mites such as Tyrophagus putrescentiae. Although some information on certain endosymbionts of N. cucumeris and T. putrescentiae exists, it is unclear whether both species share bacterial communities. The bacterial communities in populations of predator and prey mites, as well as the occurence of potential acaropathogenic bacteria were analyzed. The comparisons were based on the following groups: (i) N. cucumeris mass-production; (ii) N. cucumeris laboratory population with disease symptoms; (iii) T. putrescentiae pure populations and; (iv) T. putrescentiae from rearing units of N. cucumeris. Only 15% of OTUs were present in all samples from predatory and prey mite populations (core OTUs): the intracellular symbionts Wolbachia, Cardinium, plus other Blattabacterium-like, Solitalea-like, and Bartonella-like symbionts. Environmental bacteria were more abundant in predatory mites, while symbiotic bacteria prevailed in prey mites. Relative numbers of certain bacterial taxa were significantly different between the microbiota of prey mites reared with and without N. cucumeris. No significant differences were found in the bacterial communities of healthy N. cucumeris compared to N. cucumeris showing disease symptoms. We did not identify any confirmed acaropathogenic bacteria among microbiota.}, }
@article {pmid28118850, year = {2017}, author = {Jha, R and Gangwar, M and Chahar, D and Setty Balakrishnan, A and Negi, MP and Misra-Bhattacharya, S}, title = {Humans from Wuchereria bancrofti endemic area elicit substantial immune response to proteins of the filarial parasite Brugia malayi and its endosymbiont Wolbachia.}, journal = {Parasites &amp; vectors}, volume = {10}, number = {1}, pages = {40}, pmid = {28118850}, issn = {1756-3305}, mesh = {Animals ; Antibodies, Bacterial/analysis/immunology ; Antibodies, Helminth/analysis/immunology ; Bacterial Proteins/analysis/*immunology ; Brugia malayi/genetics/*immunology/*microbiology ; Elephantiasis, Filarial/*immunology/parasitology ; Enzyme-Linked Immunosorbent Assay ; Female ; Filariasis/*immunology/parasitology ; Helminth Proteins/analysis/*immunology ; Humans ; Immunity, Humoral ; Immunoblotting ; Leukocytes, Mononuclear/immunology/parasitology ; Symbiosis ; Wolbachia/*immunology/physiology ; Wuchereria bancrofti/genetics/*immunology ; }, abstract = {BACKGROUND: In the past, immune responses to several Brugia malayi immunodominant antigens have been characterized in filaria-infected populations; however, little is known regarding Wolbachia proteins. We earlier cloned and characterized few B. malayi (trehalose-6-phosphate phosphatase, Bm-TPP and heavy chain myosin, BmAF-Myo) and Wolbachia (translation initiation factor-1, Wol Tl IF-1 and NAD[+]-dependent DNA ligase, wBm-LigA) proteins and investigated the immune responses, which they triggered in animal models. The current study emphasizes on immunological characteristics of these proteins in three major categories of filarial endemic zones: endemic normal (EN, asymptomatic, amicrofilaraemic; putatively immune), microfilariae carriers (MF, asymptomatic but microfilaraemic), and chronic filarial patients (CP, symptomatic and mostly amicrofilaraemic).<br><br>METHODS: Immunoblotting and ELISA were carried out to measure IgG and isotype antibodies against these recombinant proteins in various clinical categories. Involvement of serum antibodies in infective larvae killing was assessed by antibody-dependent cellular adhesion and cytotoxicity assay. Cellular immune response was investigated by in vitro proliferation of peripheral blood mononuclear cells (PBMCs) and reactive oxygen species (ROS) generation in these cells after stimulation.<br><br>RESULTS: Immune responses of EN and CP displayed almost similar level of IgG to Wol Tl IF-1 while other three proteins had higher serum IgG in EN individuals only. Specific IgA, IgG1, IgG3 and IgM to Bm-TPP were high in EN subjects, while BmAF-Myo additionally showed elevated IgG2. Enhanced IgA and IgG3 were detected in both EN and CP individuals in response to Wol Tl IF-1 antigen, but IgG1 and IgM were high only in EN individuals. wBm-LigA and BmAF-Myo exhibited almost similar pattern of antibody responses. PBMC isolated from EN subjects exhibited higher proliferation and ROS generation when stimulated with all three proteins except for Wol Tl IF-1.<br><br>CONCLUSIONS: Overall, these findings display high immunogenicity of all four proteins in human subjects and revealed that the EN population was exposed to both B. malayi and Wolbachia proteins simultaneously. In addition, immune responses to Wol Tl IF-1 suggest possible role of this factor in Wolbachia-induced pathological responses while immune responses to other three proteins suggest that these can be explored further as vaccine candidates.}, }
@article {pmid28117596, year = {2017}, author = {Cheke, RA}, title = {Factors affecting onchocerciasis transmission: lessons for infection control.}, journal = {Expert review of anti-infective therapy}, volume = {15}, number = {4}, pages = {377-386}, doi = {10.1080/14787210.2017.1286980}, pmid = {28117596}, issn = {1744-8336}, mesh = {Africa/epidemiology ; Albendazole/*therapeutic use ; Animals ; Anthelmintics/*therapeutic use ; Central America/epidemiology ; Doxycycline ; Humans ; Insect Vectors/*parasitology ; Insecticides ; Ivermectin ; Macrolides ; Onchocerca volvulus/drug effects/growth &amp; development/pathogenicity ; Onchocerciasis/drug therapy/epidemiology/parasitology/*transmission ; Simuliidae/*parasitology ; South America/epidemiology ; }, abstract = {Onchocerca volvulus infects in excess of 15 million people. The vectors are Simulium blackflies, varieties of which differ in their ecologies, behavior and vectorial abilities. Control of the vectors and mass administrations of ivermectin have succeeded in reducing prevalences with elimination achieved in some foci, particularly in Central and southern America. In Africa, progress towards elimination has been less successful. Areas covered: Even with community directed treatment with ivermectin (CDTI), control has been difficult in African areas with initial prevalences in excess of 55%, especially if only annual treatments are dispensed. This is partly attributable to insufficient coverage, but the appearance of incipiently resistant non-responding parasites and lack of attention to vector biology in modeling and planning outcomes of intervention programmes have also played their parts, with recrudescence now appearing in some treated areas. Expert commentary: The biology of onchocerciasis is complex involving different vectors with differing abilities to transmit parasites, diverse pathologies related to geographical and parasite variations and endosymbionts in both parasite and vector. Modeling to predict epidemiological and control outcomes is addressing this complexity but more attention needs to be given to the vectors' roles to further understanding of where and when control measures will succeed.}, }
@article {pmid28117504, year = {2017}, author = {Pieczynska, MD and Korona, R and De Visser, JA}, title = {Experimental tests of host-virus coevolution in natural killer yeast strains.}, journal = {Journal of evolutionary biology}, volume = {30}, number = {4}, pages = {773-781}, doi = {10.1111/jeb.13044}, pmid = {28117504}, issn = {1420-9101}, mesh = {Saccharomyces ; Saccharomyces cerevisiae/*genetics/*virology ; *Symbiosis ; Virus Physiological Phenomena ; Viruses ; }, abstract = {Fungi may carry cytoplasmic viruses that encode anticompetitor toxins. These so-called killer viruses may provide competitive benefits to their host, but also incur metabolic costs associated with viral replication, toxin production and immunity. Mechanisms responsible for the stable maintenance of these endosymbionts are insufficiently understood. Here, we test whether co-adaptation of host and killer virus underlies their stable maintenance in seven natural and one laboratory strain of the genus Saccharomyces. We employ cross-transfection of killer viruses, all encoding the K1-type toxin, to test predictions from host-virus co-adaptation. These tests support local adaptation of hosts and/or their killer viruses. First, new host-virus combinations have strongly reduced killing ability against a standard sensitive strain when compared with re-constructed native combinations. Second, viruses are more likely to be lost from new than from original hosts upon repeated bottlenecking or the application of stressful conditions. Third, host fitness is increased after the re-introduction of native viruses, but decreased after the introduction of new viruses. Finally, rather than a trade-off, original combinations show a positive correlation between killing ability and fitness. Together, these results suggest that natural yeast killer strains and their viruses have co-adapted, allowing the transition from a parasitic to a mutualistic symbiosis.}, }
@article {pmid28099431, year = {2017}, author = {Castiglioni, P and Hartley, MA and Rossi, M and Prevel, F and Desponds, C and Utzschneider, DT and Eren, RO and Zangger, H and Brunner, L and Collin, N and Zehn, D and Kuhlmann, FM and Beverley, SM and Fasel, N and Ronet, C}, title = {Exacerbated Leishmaniasis Caused by a Viral Endosymbiont can be Prevented by Immunization with Its Viral Capsid.}, journal = {PLoS neglected tropical diseases}, volume = {11}, number = {1}, pages = {e0005240}, pmid = {28099431}, issn = {1935-2735}, support = {R01 AI029646/AI/NIAID NIH HHS/United States ; R56 AI099364/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Capsid Proteins/administration &amp; dosage/genetics/*immunology ; Female ; Humans ; Immunity, Cellular ; Leishmania guyanensis/genetics/immunology/physiology/*virology ; Leishmaniasis/immunology/parasitology/*prevention &amp; control ; Leishmaniavirus/genetics/*immunology/physiology ; Mice ; Mice, Inbred C57BL ; Symbiosis ; T-Lymphocytes/immunology ; Vaccination ; }, abstract = {Recent studies have shown that a cytoplasmic virus called Leishmaniavirus (LRV) is present in some Leishmania species and acts as a potent innate immunogen, aggravating lesional inflammation and development in mice. In humans, the presence of LRV in Leishmania guyanensis and in L. braziliensis was significantly correlated with poor treatment response and symptomatic relapse. So far, no clinical effort has used LRV for prophylactic purposes. In this context, we designed an original vaccine strategy that targeted LRV nested in Leishmania parasites to prevent virus-related complications. To this end, C57BL/6 mice were immunized with a recombinant LRV1 Leishmania guyanensis viral capsid polypeptide formulated with a T helper 1-polarizing adjuvant. LRV1-vaccinated mice had significant reduction in lesion size and parasite load when subsequently challenged with LRV1+ Leishmania guyanensis parasites. The protection conferred by this immunization could be reproduced in naïve mice via T-cell transfer from vaccinated mice but not by serum transfer. The induction of LRV1 specific T cells secreting IFN-γ was confirmed in vaccinated mice and provided strong evidence that LRV1-specific protection arose via a cell mediated immune response against the LRV1 capsid. Our studies suggest that immunization with LRV1 capsid could be of a preventive benefit in mitigating the elevated pathology associated with LRV1 bearing Leishmania infections and possibly avoiding symptomatic relapses after an initial treatment. This novel anti-endosymbiotic vaccine strategy could be exploited to control other infectious diseases, as similar viral infections are largely prevalent across pathogenic pathogens and could consequently open new vaccine opportunities.}, }
@article {pmid28094341, year = {2017}, author = {Luo, C and Luo, K and Meng, L and Wan, B and Zhao, H and Hu, Z}, title = {Ecological impact of a secondary bacterial symbiont on the clones of Sitobion avenae (Fabricius) (Hemiptera: Aphididae).}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {40754}, pmid = {28094341}, issn = {2045-2322}, mesh = {Animals ; Aphids/genetics/*microbiology ; *Bacteria ; Genotype ; Longevity ; *Symbiosis ; }, abstract = {Many insects harbor heritable endosymbionts, whether obligatory or facultative, and the role of facultative endosymbionts in shaping the phenotype of these species has become increasingly important. However, little is known about whether micro-injected endosymbionts can have any effects on aphid clones, which was measured using various ecological parameters. We examined the effects between symbiotic treatments and the vital life history traits generated by Regiella insecticola on the life table parameters of Sitobion avenae. The results showed that R. insecticola can decrease the intrinsic rate of increase (r), the finite rate of increase (λ) and birth rate and can increase the mean generation times (T) of S. avenae clones, suggesting that R. insecticola may decelerate the normal development of the hosts. No significant differences of these parameters were observed between the examined Sitobion avenae clones, and the symbiont treatment by genotype interaction affected only the net reproduction rate R0, pre-adult duration and total longevity but not the other parameters. Additionally, a population projection showed that R. insecticola decelerated the growth of the S. avenae clones. The evocable effects of R. insecticola on the S. avenae clones may have significant ramifications for the control of S. avenae populations under field/natural conditions.}, }
@article {pmid28091705, year = {2017}, author = {Mukhacheva, TA and Kovalev, SY}, title = {Bacteria of the Family 'Candidatus Midichloriaceae' in Sympatric Zones of Ixodes Ticks: Genetic Evidence for Vertical Transmission.}, journal = {Microbial ecology}, volume = {74}, number = {1}, pages = {185-193}, pmid = {28091705}, issn = {1432-184X}, mesh = {Alphaproteobacteria/*genetics ; Animals ; Estonia ; Genetic Variation ; Ixodes/classification/*microbiology ; *Symbiosis ; Sympatry ; }, abstract = {Ixodes ticks transmit infectious agents and also harbor their own parasites and symbionts. The presumptive endosymbiont of Ixodes ricinus, 'Candidatus Midichloria mitochondrii', has a unique ability to invade mitochondria within tick ovarian cells and is transovarially transmitted with 100% efficiency. A closely related bacterium, provisionally named Montezuma (now 'Candidatus Lariskella arthropodarum'), was isolated from the Ixodes persulcatus ticks and human blood in 2004 as well as from Ixodes pavlovskyi in 2015. These microorganisms belong to the family 'Candidatus Midichloriaceae fam. nov.' and were detected not only in tick salivary glands, but also in animal blood. Nevertheless, the relative importance of vertical and horizontal routes for their transmission or maintenance in natural tick populations remains unclear. We analyzed the prevalence of L. arthropodarum and M. mitochondrii in two sympatric zones, where I. persulcatus/I. ricinus and I. persulcatus/I. pavlovskyi cohabit and produce interspecific hybrids. A specificity of the associations of L. arthropodarum with I. persulcatus (100%) and M. mitochondrii with I. ricinus (96.2%) was observed in the sympatric zone in Estonia, possibly showing poor contribution of the horizontal route to the overall prevalence of endosymbionts. L. arthropodarum was observed probably multiplying in I. pavlovskyi and also subjected to transovarial transmission, but much less efficiently compared to I. persulcatus. We revealed two new genetic variants of the rrl-rrf intergenic spacer of L. arthropodarum isolated from I. pavlovskyi ticks that possibly could indicate an ongoing process of adaptation of the microorganism to a new host species.}, }
@article {pmid28089380, year = {2017}, author = {Cenci, U and Bhattacharya, D and Weber, APM and Colleoni, C and Subtil, A and Ball, SG}, title = {Biotic Host-Pathogen Interactions As Major Drivers of Plastid Endosymbiosis.}, journal = {Trends in plant science}, volume = {22}, number = {4}, pages = {316-328}, doi = {10.1016/j.tplants.2016.12.007}, pmid = {28089380}, issn = {1878-4372}, mesh = {Biological Evolution ; Chlamydia/metabolism/physiology ; Glycogen/metabolism ; Host-Pathogen Interactions ; Plastids/*metabolism ; Symbiosis/genetics/*physiology ; }, abstract = {The plastid originated 1.5 billion years ago through a primary endosymbiosis involving a heterotrophic eukaryote and an ancient cyanobacterium. Phylogenetic and biochemical evidence suggests that the incipient endosymbiont interacted with an obligate intracellular chlamydial pathogen that housed it in an inclusion. This aspect of the ménage-à-trois hypothesis (MATH) posits that Chlamydiales provided critical novel transporters and enzymes secreted by the pathogens in the host cytosol. This initiated the efflux of photosynthate to both the inclusion lumen and host cytosol. Here we review the experimental evidence supporting the MATH and focus on chlamydial genes that replaced existing cyanobacterial functions. The picture emerging from these studies underlines the importance of chlamydial host-pathogen interactions in the metabolic integration of the primary plastid.}, }
@article {pmid28087534, year = {2017}, author = {White, PM and Pietri, JE and Debec, A and Russell, S and Patel, B and Sullivan, W}, title = {Mechanisms of Horizontal Cell-to-Cell Transfer of Wolbachia spp. in Drosophila melanogaster.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {7}, pages = {}, pmid = {28087534}, issn = {1098-5336}, support = {R01 GM104486/GM/NIGMS NIH HHS/United States ; R25 GM056765/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Clathrin/metabolism ; Drosophila melanogaster/*cytology/*microbiology/physiology ; Dynamins/metabolism ; Germ Cells/microbiology ; In Situ Hybridization, Fluorescence ; Wolbachia/cytology/*physiology ; }, abstract = {Wolbachia is an intracellular endosymbiont present in most arthropod and filarial nematode species. Transmission between hosts is primarily vertical, taking place exclusively through the female germ line, although horizontal transmission has also been documented. The results of several studies indicate that Wolbachia spp. can undergo transfer between somatic and germ line cells during nematode development and in adult flies. However, the mechanisms underlying horizontal cell-to-cell transfer remain largely unexplored. Here, we establish a tractable system for probing horizontal transfer of Wolbachia cells between Drosophila melanogaster cells in culture using fluorescence in situ hybridization (FISH). First, we show that horizontal transfer is independent of cell-to-cell contact and can efficiently take place through the culture medium within hours. Further, we demonstrate that efficient transfer utilizes host cell phagocytic and clathrin/dynamin-dependent endocytic machinery. Lastly, we provide evidence that this process is conserved between species, showing that horizontal transfer from mosquito to Drosophila cells takes place in a similar fashion. Altogether, our results indicate that Wolbachia utilizes host internalization machinery during infection, and this mechanism is conserved across insect species.IMPORTANCE Our work has broad implications for the control and treatment of tropical diseases. Wolbachia can confer resistance against a variety of human pathogens in mosquito vectors. Elucidating the mechanisms of horizontal transfer will be useful for efforts to more efficiently infect nonnatural insect hosts with Wolbachia as a biological control agent. Further, as Wolbachia is essential for the survival of filarial nematodes, understanding horizontal transfer might provide new approaches to treating human infections by targeting Wolbachia Finally, this work provides a key first step toward the genetic manipulation of Wolbachia.}, }
@article {pmid28087421, year = {2017}, author = {Martin, WF}, title = {Physiology, anaerobes, and the origin of mitosing cells 50 years on.}, journal = {Journal of theoretical biology}, volume = {434}, number = {}, pages = {2-10}, doi = {10.1016/j.jtbi.2017.01.004}, pmid = {28087421}, issn = {1095-8541}, mesh = {*Biological Evolution ; Eukaryotic Cells/*cytology/ultrastructure ; Flagella ; Mitochondria ; *Origin of Life ; Prokaryotic Cells ; *Symbiosis ; }, abstract = {Endosymbiotic theory posits that some organelles or structures of eukaryotic cells stem from free-living prokaryotes that became endosymbionts within a host cell. Endosymbiosis has a long and turbulent history of controversy and debate going back over 100 years. The 1967 paper by Lynn Sagan (later Lynn Margulis) forced a reluctant field to take endosymbiotic theory seriously and to incorporate it into the fabric of evolutionary thinking. Margulis envisaged three cellular partners associating in series at eukaryotic origin: the host (an engulfing bacterium), the mitochondrion (a respiring bacterium), and the flagellum (a spirochaete), with lineages descended from that flagellated eukaryote subsequently acquiring plastids from cyanobacteria, but on multiple different occasions in her 1967 account. Today, the endosymbiotic origin of mitochondria and plastids (each single events, the data now say) is uncontested textbook knowledge. The host has been more elusive, recent findings identifying it as a member of the archaea, not as a sister group of the archaea. Margulis's proposal for a spirochaete origin of flagellae was abandoned by everyone except her, because no data ever came around to support the idea. Her 1967 proposal that mitochondria and plastids arose from different endosymbionts was novel. The paper presented an appealing narrative that linked the origin of mitochondria with oxygen in Earth history: cyanobacteria make oxygen, oxygen starts accumulating in the atmosphere about 2.4 billion years ago, oxygen begets oxygen-respiring bacteria that become mitochondria via symbiosis, followed by later (numerous) multiple, independent symbioses involving cyanobacteria that brought photosynthesis to eukaryotes. With the focus on oxygen, Margulis's account of eukaryote origin was however unprepared to accommodate the discovery of mitochondria in eukaryotic anaerobes. Today's oxygen narrative has it that the oceans were anoxic up until about 580 million years ago, while the atmosphere attained modern oxygen levels only about 400 million years ago. Since eukaryotes are roughly 1.6 billion years old, much of eukaryotic evolution took place in low oxygen environments, readily explaining the persistence across eukaryotic supergroups of eukaryotic anaerobes and anaerobic mitochondria at the focus of endosymbiotic theories that came after the 1967 paper.}, }
@article {pmid28081923, year = {2017}, author = {Villadas, PJ and Lasa, AV and Martínez-Hidalgo, P and Flores-Félix, JD and Martínez-Molina, E and Toro, N and Velázquez, E and Fernández-López, M}, title = {Analysis of rhizobial endosymbionts of Vicia, Lathyrus and Trifolium species used to maintain mountain firewalls in Sierra Nevada National Park (South Spain).}, journal = {Systematic and applied microbiology}, volume = {40}, number = {2}, pages = {92-101}, doi = {10.1016/j.syapm.2016.11.008}, pmid = {28081923}, issn = {1618-0984}, mesh = {Bacterial Proteins/genetics ; *Biota ; Cluster Analysis ; Lathyrus/*microbiology ; Parks, Recreational ; *Phylogeny ; Root Nodules, Plant/*microbiology ; Sequence Homology ; Spain ; Trifolium/*microbiology ; Vicia/microbiology ; }, abstract = {Forest fires lead to the annual disappearance of many natural formations that require the creation of firewall areas. They can be maintained by enriching their pastures with attractive plants for grazing livestock, mainly legumes, which have a high protein content and low dependence on N fertilizers due to their ability to establish nitrogen-fixing symbiosis with rhizobia. In this study, the rhizobia isolated from the nodules of six legumes from the genera Vicia, Lathyrus and Trifolium were analysed in a firewall zone established in Lanjarón (Granada) close to the Sierra Nevada National Park (Spain). The results showed a high genetic diversity of the isolated strains that had 3, 16, 14 and 13 different types of rrs, recA, atpD and glnII genes, respectively. All strains were phylogenetically close to the species from the Rhizobium leguminosarum group, although they were not identified as any of them. The isolated strains belonged to the symbiovars viciae and trifolii but high phylogenetic diversity was found within both symbiovars, since there were 16 and 14 nodC gene types, respectively. Some of these strains clustered with strains isolated in other countries and continents, but others formed atpD, recA, glnII and nodC clusters and lineages only found to date in this study.}, }
@article {pmid28077874, year = {2017}, author = {Zaremba-Niedzwiedzka, K and Caceres, EF and Saw, JH and Bäckström, D and Juzokaite, L and Vancaester, E and Seitz, KW and Anantharaman, K and Starnawski, P and Kjeldsen, KU and Stott, MB and Nunoura, T and Banfield, JF and Schramm, A and Baker, BJ and Spang, A and Ettema, TJ}, title = {Asgard archaea illuminate the origin of eukaryotic cellular complexity.}, journal = {Nature}, volume = {541}, number = {7637}, pages = {353-358}, pmid = {28077874}, issn = {1476-4687}, mesh = {Archaea/classification/*cytology/*genetics ; Archaeal Proteins/genetics/metabolism ; Biological Transport/genetics ; COP-Coated Vesicles/metabolism ; Eukaryota/classification/*cytology/genetics ; Eukaryotic Cells/classification/*cytology/metabolism ; *Evolution, Molecular ; Genome, Archaeal/*genetics ; Metagenomics ; *Models, Biological ; *Phylogeny ; }, abstract = {The origin and cellular complexity of eukaryotes represent a major enigma in biology. Current data support scenarios in which an archaeal host cell and an alphaproteobacterial (mitochondrial) endosymbiont merged together, resulting in the first eukaryotic cell. The host cell is related to Lokiarchaeota, an archaeal phylum with many eukaryotic features. The emergence of the structural complexity that characterizes eukaryotic cells remains unclear. Here we describe the 'Asgard' superphylum, a group of uncultivated archaea that, as well as Lokiarchaeota, includes Thor-, Odin- and Heimdallarchaeota. Asgard archaea affiliate with eukaryotes in phylogenomic analyses, and their genomes are enriched for proteins formerly considered specific to eukaryotes. Notably, thorarchaeal genomes encode several homologues of eukaryotic membrane-trafficking machinery components, including Sec23/24 and TRAPP domains. Furthermore, we identify thorarchaeal proteins with similar features to eukaryotic coat proteins involved in vesicle biogenesis. Our results expand the known repertoire of 'eukaryote-specific' proteins in Archaea, indicating that the archaeal host cell already contained many key components that govern eukaryotic cellular complexity.}, }
@article {pmid28076891, year = {2017}, author = {Uehling, J and Gryganskyi, A and Hameed, K and Tschaplinski, T and Misztal, PK and Wu, S and Desirò, A and Vande Pol, N and Du, Z and Zienkiewicz, A and Zienkiewicz, K and Morin, E and Tisserant, E and Splivallo, R and Hainaut, M and Henrissat, B and Ohm, R and Kuo, A and Yan, J and Lipzen, A and Nolan, M and LaButti, K and Barry, K and Goldstein, AH and Labbé, J and Schadt, C and Tuskan, G and Grigoriev, I and Martin, F and Vilgalys, R and Bonito, G}, title = {Comparative genomics of Mortierella elongata and its bacterial endosymbiont Mycoavidus cysteinexigens.}, journal = {Environmental microbiology}, volume = {19}, number = {8}, pages = {2964-2983}, doi = {10.1111/1462-2920.13669}, pmid = {28076891}, issn = {1462-2920}, mesh = {Animals ; Base Sequence ; Burkholderiaceae/*genetics/metabolism/physiology ; Carbohydrate Metabolism/*genetics ; Evolution, Molecular ; Genome, Bacterial/*genetics ; Genome, Fungal/*genetics ; Lipid Metabolism/*genetics ; Metabolic Networks and Pathways/genetics ; Metagenome/genetics ; Mortierella/*genetics/isolation &amp; purification/physiology ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Endosymbiosis of bacteria by eukaryotes is a defining feature of cellular evolution. In addition to well-known bacterial origins for mitochondria and chloroplasts, multiple origins of bacterial endosymbiosis are known within the cells of diverse animals, plants and fungi. Early-diverging lineages of terrestrial fungi harbor endosymbiotic bacteria belonging to the Burkholderiaceae. We sequenced the metagenome of the soil-inhabiting fungus Mortierella elongata and assembled the complete circular chromosome of its endosymbiont, Mycoavidus cysteinexigens, which we place within a lineage of endofungal symbionts that are sister clade to Burkholderia. The genome of M. elongata strain AG77 features a core set of primary metabolic pathways for degradation of simple carbohydrates and lipid biosynthesis, while the M. cysteinexigens (AG77) genome is reduced in size and function. Experiments using antibiotics to cure the endobacterium from the host demonstrate that the fungal host metabolism is highly modulated by presence/absence of M. cysteinexigens. Independent comparative phylogenomic analyses of fungal and bacterial genomes are consistent with an ancient origin for M. elongata - M. cysteinexigens symbiosis, most likely over 350 million years ago and concomitant with the terrestrialization of Earth and diversification of land fungi and plants.}, }
@article {pmid28074287, year = {2017}, author = {Minaeva, E and Ermilova, E}, title = {Responses triggered in chloroplast of Chlorella variabilis NC64A by long-term association with Paramecium bursaria.}, journal = {Protoplasma}, volume = {254}, number = {4}, pages = {1769-1776}, pmid = {28074287}, issn = {1615-6102}, mesh = {Arginine/metabolism ; Chlorella/*physiology ; Chlorophyll/metabolism ; Chloroplasts/*physiology ; Paramecium/physiology/*ultrastructure ; Plant Proteins/metabolism ; Symbiosis ; }, abstract = {The unicellular green alga Chlorella variabilis NC64A is an endosymbiont of the ciliate Paramecium bursaria. The host's control, including the transfer of biochemical substrates from P. bursaria to C. variabilis, is involved in symbiotic relationships. C. variabilis NC64A that had been re-infected to P. bursaria for more than 1 year and isolated from the host showed higher chlorophyll levels compared to those in free-living cells. Unlike the host, the expression of C. variabilis NC64A heat shock 70 kDa protein was independent of establishment of endosymbiosis. In symbiotic cells, the levels of PII signal transduction protein (CvPII) that coordinate the central C/N anabolic metabolism were slightly higher than those in free-living cells. Furthermore, the environmental cues (light and host food bacteria availability) affected the abundance of CvPII, suggesting that synthesis of the protein was influenced by the host. Moreover, arginine concentrations in the symbiotic algae of P. bursaria were also controlled by the host's nutritional conditions. Together, our results imply that signal substrates and/or products of metabolism in host cells might act as messengers mediating the regulation of key events in symbiont cells.}, }
@article {pmid28067273, year = {2017}, author = {Chong, G and Kuo, FW and Tsai, S and Lin, C}, title = {Validation of reference genes for cryopreservation studies with the gorgonian coral endosymbiont Symbiodinium.}, journal = {Scientific reports}, volume = {7}, number = {}, pages = {39396}, pmid = {28067273}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/*parasitology ; Cryopreservation/*methods ; Dinoflagellida/*genetics/*physiology ; Genes, Essential ; Real-Time Polymerase Chain Reaction/*methods/*standards ; *Reference Standards ; Symbiosis ; }, abstract = {Quantification by real-time RT-PCR requires a stable internal reference known as a housekeeping gene (HKG) for normalising the mRNA levels of target genes. The present study identified and validated stably expressed HKGs in post-thaw Symbiodinium clade G. Six potential HKGs, namely, pcna, gapdh, 18S rRNA, hsp90, rbcl, and ps1, were analysed using three different algorithms, namely, GeNorm, NormFinder, and BestKeeper. The GeNorm algorithm ranked the candidate genes as follows in the order of decreasing stability: pcna and gapdh > ps1 > 18S rRNA > hsp90 > rbcl. Results obtained using the NormFinder algorithm also showed that pcna was the most stable HKG and ps1 was the second most stable HKG. We found that the candidate HKGs examined in this study showed variable stability with respect to the three algorithms. These results indicated that both pcna and ps1 were suitable for normalising target gene expression determined by performing real-time RT-PCR in cryopreservation studies on Symbiodinium clade G. The results of the present study would help future studies to elucidate the effect of cryopreservation on gene expression in dinoflagellates.}, }
@article {pmid28066397, year = {2016}, author = {Bella, C and Koehler, L and Grosser, K and Berendonk, TU and Petroni, G and Schrallhammer, M}, title = {Fitness Impact of Obligate Intranuclear Bacterial Symbionts Depends on Host Growth Phase.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {2084}, pmid = {28066397}, issn = {1664-302X}, abstract = {According to text book definition, parasites reduce the fitness of their hosts whereas mutualists provide benefits. But biotic and abiotic factors influence symbiotic interactions, thus under certain circumstances parasites can provide benefits and mutualists can harm their host. Here we addressed the question which intrinsic biotic factors shape a symbiosis and are crucial for the outcome of the interaction between the obligate intranuclear bacterium Holospora caryophila (Alphaproteobacteria; Rickettsiales) and its unicellular eukaryotic host Paramecium biaurelia (Alveolata; Ciliophora). The virulence of H. caryophila, i.e., the negative fitness effect on host division and cell number, was determined by growth assays of several P. biaurelia strains. The performances of genetically identical lines either infected with H. caryophila or symbiont-free were compared. Following factors were considered as potentially influencing the outcome of the interaction: (1) host strain, (2) parasite strain, and (3) growth phases of the host. All three factors revealed a strong effect on the symbiosis. In presence of H. caryophila, the Paramecium density in the stationary growth phase decreased. Conversely, a positive effect of the bacteria during the exponential phase was observed for several host × parasite combinations resulting in an increased growth rate of infected P. biaurelia. Furthermore, the fitness impact of the tested endosymbionts on different P. biaurelia lines was not only dependent on one of the two involved strains but distinct for the specific combination. Depending on the current host growth phase, the presence of H. caryophila can be harmful or advantageous for P. biaurelia. Thus, under the tested experimental conditions, the symbionts can switch from the provision of benefits to the exploitation of host resources within the same host population and a time-span of less than 6 days.}, }
@article {pmid28066124, year = {2017}, author = {Gagat, P and Mackiewicz, P}, title = {Cymbomonas tetramitiformis - a peculiar prasinophyte with a taste for bacteria sheds light on plastid evolution.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {71}, number = {1}, pages = {1-7}, pmid = {28066124}, issn = {0334-5114}, abstract = {Cymbomonas tetramitiformis is a peculiar green alga that unites in one cell the abilities of photosynthesis and phagocytosis, which makes it a very useful model for the study of the evolution of plastid endosymbiosis. We have pondered over this issue and propose an evolutionary scenario of trophic strategies in eukaryotes, including primary and secondary plastid endosymbioses. C. tetramitiformis is a prototroph, just like the common ancestor of Archaeplastida was, and can synthesize most small organic molecules contrary to other eukaryotic phagotrophs, e.g. some metazoans, amoebozoans, and ciliates, which have not evolved tight endosymbiotic relationships. In order to establish a permanent photosynthetic endosymbiont they do not have to become prototrophs, but have to acquire the genes necessary for plastid retention via horizontal (including endosymbiotic) gene transfer. Such processes occurred successfully in the ancestors of eukaryotes with permanent secondary plastids and thus led to their great diversification. The preservation of phagocytosis in Cymbomonas (and some other prasinophytes as well) seems to result from nutrient deficiency in their oligotrophic habitats. This forces them to supplement their diet with phagocytized prey, in contrasts to the thecate amoeba Paulinella chromatophora, which also successfully transformed cyanobacteria into permanent organelles. Although Paulinella endosymbionts were acquired very recently in comparison to primary plastids, Paulinella has lost the ability to phagocytose, most probably due to the fact that it inhabits nutrient-rich environments, which renders the phagotrophy nonessential.}, }
@article {pmid28064061, year = {2017}, author = {Hess, S}, title = {Description of Hyalodiscus flabellus sp. nov. (Vampyrellida, Rhizaria) and Identification of its Bacterial Endosymbiont, "Candidatus Megaira polyxenophila" (Rickettsiales, Alphaproteobacteria).}, journal = {Protist}, volume = {168}, number = {1}, pages = {109-133}, doi = {10.1016/j.protis.2016.11.003}, pmid = {28064061}, issn = {1618-0941}, mesh = {Alphaproteobacteria/*physiology/ultrastructure ; Cercozoa/*classification/*microbiology/ultrastructure ; Microscopy, Electron, Transmission ; Phylogeny ; RNA, Protozoan/genetics ; Sequence Analysis, RNA ; Symbiosis ; }, abstract = {The genus Hyalodiscus Hertwig and Lesser, 1874 comprises naked freshwater amoebae with a unique set of characters, namely a vibrant orange-red colour, a discoid or fan-shaped morphology, and a characteristic rolling locomotion. Some species feed on the chloroplasts of green algae and were regarded as relatives of Vampyrella Cienkowski, 1865. However, because of striking morphological differences and the lack of molecular data, the exact relationship of Hyalodiscus to vampyrellids is still obscure. Here, I describe Hyalodiscus flabellus sp. nov., a bright orange, fan-shaped amoeba feeding on Oedogonium (Chlorophyceae), which likely is a close relative of the type species H. rubicundus Hertwig and Lesser, 1874. Sequence comparisons of the SSU rRNA gene revealed that H. flabellus belongs to a deep-branching, so far uncharacterised lineage of the order Vampyrellida (Rhizaria), here defined as family Hyalodiscidae POCHE, 1913. Based on these results, the systematic position of the genus Hyalodiscus could be finally clarified, accompanied by the revision of relevant diagnoses and a taxonomic summary. Furthermore, the work reports on endosymbiotic bacteria inhabiting the cytoplasm of H. flabellus, which were identified as "Candidatus Megaira polyxenophila" (Rickettsiales, Alphaproteobacteria) using the full cycle rRNA approach with newly designed FISH probes for this widespread endosymbiotic bacterium.}, }
@article {pmid28062461, year = {2017}, author = {Msaddak, A and Durán, D and Rejili, M and Mars, M and Ruiz-Argüeso, T and Imperial, J and Palacios, J and Rey, L}, title = {Diverse Bacteria Affiliated with the Genera Microvirga, Phyllobacterium, and Bradyrhizobium Nodulate Lupinus micranthus Growing in Soils of Northern Tunisia.}, journal = {Applied and environmental microbiology}, volume = {83}, number = {6}, pages = {}, pmid = {28062461}, issn = {1098-5336}, mesh = {Biodiversity ; Bradyrhizobium/classification/genetics/*isolation &amp; purification ; DNA Gyrase/genetics ; DNA, Bacterial/genetics ; Genes, Essential/genetics ; Lupinus/*microbiology ; Methylobacteriaceae/classification/genetics/*isolation &amp; purification ; Phyllobacteriaceae/classification/genetics/*isolation &amp; purification ; Phylogeny ; Plant Root Nodulation/physiology ; RNA, Ribosomal, 16S/genetics ; Rec A Recombinases/genetics ; Root Nodules, Plant/*microbiology ; Soil Microbiology ; Symbiosis/physiology ; Tunisia ; }, abstract = {The genetic diversity of bacterial populations nodulating Lupinus micranthus in five geographical sites from northern Tunisia was examined. Phylogenetic analyses of 50 isolates based on partial sequences of recA and gyrB grouped strains into seven clusters, five of which belong to the genus Bradyrhizobium (28 isolates), one to Phyllobacterium (2 isolates), and one, remarkably, to Microvirga (20 isolates). The largest Bradyrhizobium cluster (17 isolates) grouped with the B. lupini species, and the other five clusters were close to different recently defined Bradyrhizobium species. Isolates close to Microvirga were obtained from nodules of plants from four of the five sites sampled. We carried out an in-depth phylogenetic study with representatives of the seven clusters using sequences from housekeeping genes (rrs, recA, glnII, gyrB, and dnaK) and obtained consistent results. A phylogeny based on the sequence of the symbiotic gene nodC identified four groups, three formed by Bradyrhizobium isolates and one by the Microvirga and Phyllobacterium isolates. Symbiotic behaviors of the representative strains were tested, and some congruence between symbiovars and symbiotic performance was observed. These data indicate a remarkable diversity of L. micranthus root nodule symbionts in northern Tunisia, including strains from the Bradyrhizobiaceae, Methylobacteriaceae, and Phyllobacteriaceae families, in contrast with those of the rhizobial populations nodulating lupines in the Old World, including L. micranthus from other Mediterranean areas, which are nodulated mostly by Bradyrhizobium strains.IMPORTANCELupinus micranthus is a legume broadly distributed in the Mediterranean region and plays an important role in soil fertility and vegetation coverage by fixing nitrogen and solubilizing phosphate in semiarid areas. Direct sowing to extend the distribution of this indigenous legume can contribute to the prevention of soil erosion in pre-Saharan lands of Tunisia. However, rhizobial populations associated with L. micranthus are poorly understood. In this context, the diversity of endosymbionts of this legume was investigated. Most Lupinus species are nodulated by Bradyrhizobium strains. This work showed that about half of the isolates from northern Tunisian soils were in fact Bradyrhizobium symbionts, but the other half were found unexpectedly to be bacteria within the genera Microvirga and Phyllobacterium These unusual endosymbionts may have a great ecological relevance. Inoculation with the appropriate selected symbiotic bacterial partners will increase L. micranthus survival with consequent advantages for the environment in semiarid areas of Tunisia.}, }
@article {pmid28055138, year = {2017}, author = {Vorburger, C and Herzog, J and Rouchet, R}, title = {Aphid specialization on different summer hosts is associated with strong genetic differentiation and unequal symbiont communities despite a common mating habitat.}, journal = {Journal of evolutionary biology}, volume = {30}, number = {4}, pages = {762-772}, doi = {10.1111/jeb.13040}, pmid = {28055138}, issn = {1420-9101}, mesh = {Animals ; Aphids/*genetics ; Ecosystem ; France ; Genotype ; *Reproductive Isolation ; Seasons ; Switzerland ; *Symbiosis ; }, abstract = {Specialization on different host plants can promote evolutionary diversification of herbivorous insects. Work on pea aphids (Acyrthosiphon pisum) has contributed significantly to the understanding of this process, demonstrating that populations associated with different host plants exhibit performance trade-offs across hosts, show adaptive host choice and genetic differentiation and possess different communities of bacterial endosymbionts. Populations specialized on different secondary host plants during the parthenogenetic summer generations are also described for the black bean aphid (Aphis fabae complex) and are usually treated as different (morphologically cryptic) subspecies. In contrast to pea aphids, however, host choice and mate choice are decoupled in black bean aphids, because populations from different summer hosts return to the same primary host plant to mate and lay overwintering eggs. This could counteract evolutionary divergence, and it is currently unknown to what extent black bean aphids using different summer hosts are indeed differentiated. We addressed this question by microsatellite genotyping and endosymbiont screening of black bean aphids collected in summer from the goosefoot Chenopodium album (subspecies A. f. fabae) and from thistles of the genus Cirsium (subspecies A. f. cirsiiacanthoides) across numerous sites in Switzerland and France. Our results show clearly that aphids from Cirsium and Chenopodium exhibit strong and geographically consistent genetic differentiation and that they differ in their frequencies of infection with particular endosymbionts. The dependence on a joint winter host has thus not prevented the evolutionary divergence into summer host-adapted populations that appear to have evolved mechanisms of reproductive isolation within a common mating habitat.}, }
@article {pmid28049478, year = {2017}, author = {Caragata, EP and Pais, FS and Baton, LA and Silva, JB and Sorgine, MH and Moreira, LA}, title = {The transcriptome of the mosquito Aedes fluviatilis (Diptera: Culicidae), and transcriptional changes associated with its native Wolbachia infection.}, journal = {BMC genomics}, volume = {18}, number = {1}, pages = {6}, pmid = {28049478}, issn = {1471-2164}, mesh = {Aedes/*genetics/*microbiology ; Animals ; Computational Biology/methods ; Contig Mapping ; *Gene Expression Profiling ; Gene Expression Regulation ; Gene Ontology ; High-Throughput Nucleotide Sequencing ; Host-Pathogen Interactions/*genetics ; Molecular Sequence Annotation ; *Transcriptome ; *Wolbachia ; }, abstract = {BACKGROUND: Wolbachia is a bacterial endosymbiont that naturally infects a wide range of insect species, and causes drastic changes to host biology. Stable infections of Wolbachia in mosquitoes can inhibit infection with medically important pathogens such as dengue virus and malaria-causing Plasmodium parasites. However, some native Wolbachia strains can enhance infection with certain pathogens, as is the case for the mosquito Aedes fluviatilis, where infection with Plasmodium gallinaceum is enhanced by the native wFlu Wolbachia strain. To better understand the biological interactions between mosquitoes and native Wolbachia infections, and to investigate the process of pathogen enhancement, we used RNA-Seq to generate the transcriptome of Ae. fluviatilis with and without Wolbachia infection.<br><br>RESULTS: In total, we generated 22,280,160 Illumina paired-end reads from Wolbachia-infected and uninfected mosquitoes, and used these to make a de novo transcriptome assembly, resulting in 58,013 contigs with a median sequence length of 443 bp and an N50 of 2454 bp. Contigs were annotated through local alignments using BlastX, and associated with both gene ontology and KEGG orthology terms. Through baySeq, we identified 159 contigs that were significantly upregulated due to Wolbachia infection, and 98 that were downregulated. Critically, we saw no changes to Toll or IMD immune gene transcription, but did see evidence that wFlu infection altered the expression of several bacterial recognition genes, and immune-related genes that could influence Plasmodium infection. wFlu infection also had a widespread effect on a number of host physiological processes including protein, carbohydrate and lipid metabolism, and oxidative stress. We then compared our data set with transcriptomic data for other Wolbachia infections in Aedes aegypti, and identified a core set of 15 gene groups associated with Wolbachia infection in mosquitoes.<br><br>CONCLUSIONS: While the scale of transcriptional changes associated with wFlu infection might be small, the scope is rather large, which confirms that native Wolbachia infections maintain intricate molecular relationships with their mosquito hosts even after lengthy periods of co-evolution. We have also identified several potential means through which wFlu infection might influence Plasmodium infection in Ae. fluviatilis, and these genes should form the basis of future investigation into the enhancement of Plasmodium by Wolbachia.}, }
@article {pmid28040856, year = {2017}, author = {López, MF and Cabrera, JJ and Salas, A and Delgado, MJ and López-García, SL}, title = {Dissecting the role of NtrC and RpoN in the expression of assimilatory nitrate and nitrite reductases in Bradyrhizobium diazoefficiens.}, journal = {Antonie van Leeuwenhoek}, volume = {110}, number = {4}, pages = {531-542}, doi = {10.1007/s10482-016-0821-3}, pmid = {28040856}, issn = {1572-9699}, mesh = {Bacterial Proteins/*genetics/metabolism ; Bradyrhizobium/genetics/growth &amp; development/*metabolism ; Denitrification/physiology ; Nitrate Reductase/genetics/*metabolism ; Nitrite Reductases/genetics/*metabolism ; Sigma Factor/*genetics ; Soybeans/microbiology ; }, abstract = {Bradyrhizobium diazoefficiens, a nitrogen-fixing endosymbiont of soybeans, is a model strain for studying rhizobial denitrification. This bacterium can also use nitrate as the sole nitrogen (N) source during aerobic growth by inducing an assimilatory nitrate reductase encoded by nasC located within the narK-bjgb-flp-nasC operon along with a nitrite reductase encoded by nirA at a different chromosomal locus. The global nitrogen two-component regulatory system NtrBC has been reported to coordinate the expression of key enzymes in nitrogen metabolism in several bacteria. In this study, we demonstrate that disruption of ntrC caused a growth defect in B. diazoefficiens cells in the presence of nitrate or nitrite as the sole N source and a decreased activity of the nitrate and nitrite reductase enzymes. Furthermore, the expression of narK-lacZ or nirA-lacZ transcriptional fusions was significantly reduced in the ntrC mutant after incubation under nitrate assimilation conditions. A B. diazoefficiens rpoN 1/2 mutant, lacking both copies of the gene encoding the alternative sigma factor σ[54], was also defective in aerobic growth with nitrate as the N source as well as in nitrate and nitrite reductase expression. These results demonstrate that the NtrC regulator is required for expression of the B. diazoefficiens nasC and nirA genes and that the sigma factor RpoN is also involved in this regulation.}, }
@article {pmid28035670, year = {2017}, author = {García-Portela, M and Riobó, P and Rodríguez, F}, title = {Morphological and molecular study of the cyanobiont-bearing dinoflagellate Sinophysis canaliculata from the Canary Islands (eastern central Atlantic).}, journal = {Journal of phycology}, volume = {53}, number = {2}, pages = {446-450}, doi = {10.1111/jpy.12508}, pmid = {28035670}, issn = {1529-8817}, mesh = {Atlantic Islands ; Cyanobacteria/genetics/metabolism ; DNA, Ribosomal/genetics ; Dinoflagellida/genetics/*metabolism ; Genetic Variation/genetics ; Phylogeny ; Symbiosis/genetics/physiology ; }, abstract = {The presence of the benthic dinophysoid dinoflagellate Sinophysis canaliculata has been reported in the Canary Islands (eastern central Atlantic) in live field observations and on fixed macroalgal samples from intertidal ponds (26 sampling sites from El Hierro, Tenerife, Gran Canaria, Fuerteventura and Lanzarote islands). In vivo Sinophysis cells were typically pale pink colored. Light microscopy and scanning electron microscopy micrographs showed a small characteristic narrow hypothecal cut that matched the original description of S. canaliculata. SSU rRNA gene (rDNA) nuclear phylogeny showed that S. canaliculata is closely related to S. microcephalus. Sinophysis specimens displayed cyanobacterial endosymbionts with orange autofluorescence from phycoerythrins. SSU rDNA analyses of the cyanobionts nearly matched a former sequence obtained from S. canaliculata in the Pacific Ocean (Japan). S. canaliculata survived up to 5 months in the original seawater samples. During that period cyanobionts were always present and maintained their orange autofluorescence, although the pink color gradually vanished (<1 month) in most individuals. Molecular similarity of Sinophysis cyanobionts from the Canary Islands and Japanese waters suggest a deterministic relationship, likely a temporary maintenance inside their host via some specific grazing system.}, }
@article {pmid28025277, year = {2017}, author = {Christie, JR and Beekman, M}, title = {Uniparental Inheritance Promotes Adaptive Evolution in Cytoplasmic Genomes.}, journal = {Molecular biology and evolution}, volume = {34}, number = {3}, pages = {677-691}, pmid = {28025277}, issn = {1537-1719}, mesh = {Adaptation, Biological/*genetics ; Biological Evolution ; Computer Simulation ; DNA, Mitochondrial/*genetics ; Eukaryota/genetics ; Evolution, Molecular ; Genome ; Mitochondria/genetics ; *Models, Genetic ; Mutation ; *Mutation Rate ; Plastids/genetics ; Reproduction/genetics ; }, abstract = {Eukaryotes carry numerous asexual cytoplasmic genomes (mitochondria and plastids). Lacking recombination, asexual genomes should theoretically suffer from impaired adaptive evolution. Yet, empirical evidence indicates that cytoplasmic genomes experience higher levels of adaptive evolution than predicted by theory. In this study, we use a computational model to show that the unique biology of cytoplasmic genomes-specifically their organization into host cells and their uniparental (maternal) inheritance-enable them to undergo effective adaptive evolution. Uniparental inheritance of cytoplasmic genomes decreases competition between different beneficial substitutions (clonal interference), promoting the accumulation of beneficial substitutions. Uniparental inheritance also facilitates selection against deleterious cytoplasmic substitutions, slowing Muller's ratchet. In addition, uniparental inheritance generally reduces genetic hitchhiking of deleterious substitutions during selective sweeps. Overall, uniparental inheritance promotes adaptive evolution by increasing the level of beneficial substitutions relative to deleterious substitutions. When we assume that cytoplasmic genome inheritance is biparental, decreasing the number of genomes transmitted during gametogenesis (bottleneck) aids adaptive evolution. Nevertheless, adaptive evolution is always more efficient when inheritance is uniparental. Our findings explain empirical observations that cytoplasmic genomes-despite their asexual mode of reproduction-can readily undergo adaptive evolution.}, }
@article {pmid28017611, year = {2017}, author = {Ribeiro, CW and Baldacci-Cresp, F and Pierre, O and Larousse, M and Benyamina, S and Lambert, A and Hopkins, J and Castella, C and Cazareth, J and Alloing, G and Boncompagni, E and Couturier, J and Mergaert, P and Gamas, P and Rouhier, N and Montrichard, F and Frendo, P}, title = {Regulation of Differentiation of Nitrogen-Fixing Bacteria by Microsymbiont Targeting of Plant Thioredoxin s1.}, journal = {Current biology : CB}, volume = {27}, number = {2}, pages = {250-256}, doi = {10.1016/j.cub.2016.11.013}, pmid = {28017611}, issn = {1879-0445}, mesh = {Cysteine/chemistry/genetics/metabolism ; Gene Expression Regulation, Plant ; Medicago truncatula/*growth &amp; development/microbiology ; Nitrogen-Fixing Bacteria/drug effects/*growth &amp; development ; Peptide Fragments/metabolism ; Root Nodules, Plant/*growth &amp; development/microbiology ; Signal Transduction ; Sinorhizobium meliloti/drug effects/*growth &amp; development ; Symbiosis ; Thioredoxins/*antagonists &amp; inhibitors ; }, abstract = {Legumes associate with rhizobia to form nitrogen (N2)-fixing nodules, which is important for plant fitness [1, 2]. Medicago truncatula controls the terminal differentiation of Sinorhizobium meliloti into N2-fixing bacteroids by producing defensin-like nodule-specific cysteine-rich peptides (NCRs) [3, 4]. The redox state of NCRs influences some biological activities in free-living bacteria, but the relevance of redox regulation of NCRs in planta is unknown [5, 6], although redox regulation plays a crucial role in symbiotic nitrogen fixation [7, 8]. Two thioredoxins (Trx), Trx s1 and s2, define a new type of Trx and are expressed principally in nodules [9]. Here, we show that there are four Trx s genes, two of which, Trx s1 and s3, are induced in the nodule infection zone where bacterial differentiation occurs. Trx s1 is targeted to the symbiosomes, the N2-fixing organelles. Trx s1 interacted with NCR247 and NCR335 and increased the cytotoxic effect of NCR335 in S. meliloti. We show that Trx s silencing impairs bacteroid growth and endoreduplication, two features of terminal bacteroid differentiation, and that the ectopic expression of Trx s1 in S. meliloti partially complements the silencing phenotype. Thus, our findings show that Trx s1 is targeted to the bacterial endosymbiont, where it controls NCR activity and bacteroid terminal differentiation. Similarly, Trxs are critical for the activation of defensins produced against infectious microbes in mammalian hosts. Therefore, our results suggest the Trx-mediated regulation of host peptides as a conserved mechanism among symbiotic and pathogenic interactions.}, }
@article {pmid28011783, year = {2017}, author = {Lafond-Lapalme, J and Duceppe, MO and Wang, S and Moffett, P and Mimee, B}, title = {A new method for decontamination of de novo transcriptomes using a hierarchical clustering algorithm.}, journal = {Bioinformatics (Oxford, England)}, volume = {33}, number = {9}, pages = {1293-1300}, doi = {10.1093/bioinformatics/btw793}, pmid = {28011783}, issn = {1367-4811}, mesh = {Algorithms ; Animals ; Cluster Analysis ; Gene Expression Profiling/methods ; Sequence Analysis, RNA/*methods ; *Software ; *Transcriptome ; Tylenchida/genetics ; Weevils/genetics/parasitology ; }, abstract = {MOTIVATION: The identification of contaminating sequences in a de novo assembly is challenging because of the absence of information on the target species. For sample types where the target organism is impossible to isolate from its matrix, such as endoparasites, endosymbionts and soil-harvested samples, contamination is unavoidable. A few post-assembly decontamination methods are currently available but are based only on alignments to databases, which can lead to poor decontamination.<br><br>RESULTS: We present a new decontamination method based on a hierarchical clustering algorithm called MCSC. This method uses frequent patterns found in sequences to create clusters. These clusters are then linked to the target species or tagged as contaminants using classic alignment tools. The main advantage of this decontamination method is that it allows sequences to be tagged correctly even if they are unknown or misaligned to a database.<br><br>Scripts and documentation about the MCSC decontamination method are available at https://github.com/Lafond-LapalmeJ/MCSC_Decontamination .<br><br>CONTACT: : benjamin.mimee@agr.gc.ca.<br><br>SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.}, }
@article {pmid28009488, year = {2017}, author = {Godkin, A and Smith, KA}, title = {Chronic infections with viruses or parasites: breaking bad to make good.}, journal = {Immunology}, volume = {150}, number = {4}, pages = {389-396}, pmid = {28009488}, issn = {1365-2567}, mesh = {Animals ; Chronic Disease ; Communicable Diseases/*immunology ; Homeostasis ; *Host-Parasite Interactions ; Humans ; *Immunity, Mucosal ; Parasitic Diseases/*immunology ; Symbiosis ; Virus Diseases/*immunology ; }, abstract = {Eukaryotic forms of life have been continually invaded by microbes and larger multicellular parasites, such as helminths. Over a billion years ago bacterial endosymbionts permanently colonized eukaryotic cells leading to recognized organelles with a distinct genetic lineage, such as mitochondria and chloroplasts. Colonization of our skin and mucosal surfaces with bacterial commensals is now known to be important for host health. However, the contribution of chronic virus and parasitic infections to immune homeostasis is being increasingly questioned. Persistent infection does not necessarily equate to exhibiting a chronic illness: healthy hosts (e.g. humans) have chronic viral and parasitic infections with no evidence of disease. Indeed, there are now examples of complex interactions between these microbes and hosts that seem to confer an advantage to the host at a particular time, suggesting that the relationship has progressed along an axis from parasitic to commensal to one of a mutualistic symbiosis. This concept is explored using examples from viruses and parasites, considering how the relationships may be not only detrimental but also beneficial to the human host.}, }
@article {pmid28004835, year = {2016}, author = {Aranda, M and Li, Y and Liew, YJ and Baumgarten, S and Simakov, O and Wilson, MC and Piel, J and Ashoor, H and Bougouffa, S and Bajic, VB and Ryu, T and Ravasi, T and Bayer, T and Micklem, G and Kim, H and Bhak, J and LaJeunesse, TC and Voolstra, CR}, title = {Genomes of coral dinoflagellate symbionts highlight evolutionary adaptations conducive to a symbiotic lifestyle.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {39734}, pmid = {28004835}, issn = {2045-2322}, mesh = {Adaptation, Biological/*physiology ; Animals ; Anthozoa/*physiology ; Dinoflagellida/classification/*genetics ; *Evolution, Molecular ; *Genome ; Symbiosis/*physiology ; }, abstract = {Despite half a century of research, the biology of dinoflagellates remains enigmatic: they defy many functional and genetic traits attributed to typical eukaryotic cells. Genomic approaches to study dinoflagellates are often stymied due to their large, multi-gigabase genomes. Members of the genus Symbiodinium are photosynthetic endosymbionts of stony corals that provide the foundation of coral reef ecosystems. Their smaller genome sizes provide an opportunity to interrogate evolution and functionality of dinoflagellate genomes and endosymbiosis. We sequenced the genome of the ancestral Symbiodinium microadriaticum and compared it to the genomes of the more derived Symbiodinium minutum and Symbiodinium kawagutii and eukaryote model systems as well as transcriptomes from other dinoflagellates. Comparative analyses of genome and transcriptome protein sets show that all dinoflagellates, not only Symbiodinium, possess significantly more transmembrane transporters involved in the exchange of amino acids, lipids, and glycerol than other eukaryotes. Importantly, we find that only Symbiodinium harbor an extensive transporter repertoire associated with the provisioning of carbon and nitrogen. Analyses of these transporters show species-specific expansions, which provides a genomic basis to explain differential compatibilities to an array of hosts and environments, and highlights the putative importance of gene duplications as an evolutionary mechanism in dinoflagellates and Symbiodinium.}, }
@article {pmid27999386, year = {2016}, author = {Ospina, OE and Massey, SE and Verle Rodrigues, JC}, title = {Reduced Diversity in the Bacteriome of the Phytophagous Mite Brevipalpus yothersi (Acari: Tenuipalpidae).}, journal = {Insects}, volume = {7}, number = {4}, pages = {}, pmid = {27999386}, issn = {2075-4450}, abstract = {Tenuipalpidae comprises mites that transmit viruses to agriculturally important plants. Several tenuipalpid species present parthenogenesis, and in Brevipalpus yothersi, the endosymbiont Cardinium has been associated with female-only colonies. It is unclear what the bacterial composition of B. yothersi is, and how common Cardinium is in those microbiomes. We performed a comparative analysis of the bacteriomes in three populations of B. yothersi and three additional Tetranychoidea species using sequences from V4-fragment of 16S DNA. The bacteriomes were dominated by Bacteroidetes (especially Cardinium) and Proteobacteria, showing a remarkably low alpha diversity. Cardinium was present in about 22% of all sequences; however, it was not present in R. indica and T. evansi. In B. yothersi, the proportion of Cardinium was higher in adults than eggs, suggesting that proliferation of the bacteria could be the result of selective pressures from the host. This hypothesis was further supported because colonies of B. yothersi from different populations showed different bacterial assemblages, and bacteriomes from different mite species showed similar abundances of Cardinium. A phylogenetic analysis of Cardinium revealed that not only specialization but horizontal transmission has been important for this symbiosis. Together, these results represent a glimpse into the evolution of the Tetranychoidea and Cardinium.}, }
@article {pmid27996008, year = {2016}, author = {Zehr, JP and Shilova, IN and Farnelid, HM and Muñoz-Marín, MD and Turk-Kubo, KA}, title = {Unusual marine unicellular symbiosis with the nitrogen-fixing cyanobacterium UCYN-A.}, journal = {Nature microbiology}, volume = {2}, number = {}, pages = {16214}, doi = {10.1038/nmicrobiol.2016.214}, pmid = {27996008}, issn = {2058-5276}, abstract = {Nitrogen fixation - the reduction of dinitrogen (N2) gas to biologically available nitrogen (N) - is an important source of N for terrestrial and aquatic ecosystems. In terrestrial environments, N2-fixing symbioses involve multicellular plants, but in the marine environment these symbioses occur with unicellular planktonic algae. An unusual symbiosis between an uncultivated unicellular cyanobacterium (UCYN-A) and a haptophyte picoplankton alga was recently discovered in oligotrophic oceans. UCYN-A has a highly reduced genome, and exchanges fixed N for fixed carbon with its host. This symbiosis bears some resemblance to symbioses found in freshwater ecosystems. UCYN-A shares many core genes with the 'spheroid bodies' of Epithemia turgida and the endosymbionts of the amoeba Paulinella chromatophora. UCYN-A is widely distributed, and has diversified into a number of sublineages that could be ecotypes. Many questions remain regarding the physical and genetic mechanisms of the association, but UCYN-A is an intriguing model for contemplating the evolution of N2-fixing organelles.}, }
@article {pmid27992463, year = {2016}, author = {Lanzoni, O and Fokin, SI and Lebedeva, N and Migunova, A and Petroni, G and Potekhin, A}, title = {Rare Freshwater Ciliate Paramecium chlorelligerum Kahl, 1935 and Its Macronuclear Symbiotic Bacterium "Candidatus Holospora parva".}, journal = {PloS one}, volume = {11}, number = {12}, pages = {e0167928}, pmid = {27992463}, issn = {1932-6203}, mesh = {Chlorella/*classification/genetics/isolation &amp; purification ; Cytoplasm/chemistry ; DNA, Ribosomal/analysis ; Fresh Water/*parasitology ; Holosporaceae/*classification/genetics/isolation &amp; purification ; Macronucleus/genetics ; Paramecium/*classification/genetics/isolation &amp; purification/microbiology ; Phylogeny ; RNA, Ribosomal/analysis ; Symbiosis ; }, abstract = {Ciliated protists often form symbioses with many diverse microorganisms. In particular, symbiotic associations between ciliates and green algae, as well as between ciliates and intracellular bacteria, are rather wide-spread in nature. In this study, we describe the complex symbiotic system between a very rare ciliate, Paramecium chlorelligerum, unicellular algae inhabiting its cytoplasm, and novel bacteria colonizing the host macronucleus. Paramecium chlorelligerum, previously found only twice in Germany, was retrieved from a novel location in vicinity of St. Petersburg in Russia. Species identification was based on both classical morphological methods and analysis of the small subunit rDNA. Numerous algae occupying the cytoplasm of this ciliate were identified with ultrastructural and molecular methods as representatives of the Meyerella genus, which before was not considered among symbiotic algae. In the same locality at least fifteen other species of "green" ciliates were found, thus it is indeed a biodiversity hot-spot for such protists. A novel species of bacterial symbionts living in the macronucleus of Paramecium chlorelligerum cells was morphologically and ultrastructurally investigated in detail with the description of its life cycle and infection capabilities. The new endosymbiont was molecularly characterized following the full-cycle rRNA approach. Furthermore, phylogenetic analysis confirmed that the novel bacterium is a member of Holospora genus branching basally but sharing all characteristics of the genus except inducing connecting piece formation during the infected host nucleus division. We propose the name "Candidatus Holospora parva" for this newly described species. The described complex system raises new questions on how these microorganisms evolve and interact in symbiosis.}, }
@article {pmid27990558, year = {2017}, author = {Gill, TA and Chu, C and Pelz-Stelinski, KS}, title = {Comparative proteomic analysis of hemolymph from uninfected and Candidatus Liberibacter asiaticus-infected Diaphorina citri.}, journal = {Amino acids}, volume = {49}, number = {2}, pages = {389-406}, doi = {10.1007/s00726-016-2373-2}, pmid = {27990558}, issn = {1438-2199}, mesh = {Animals ; Hemiptera/*microbiology ; Hemolymph/*metabolism/microbiology ; Host-Pathogen Interactions ; Insect Proteins/*analysis/metabolism ; Proteomics/*methods ; Rhizobiaceae/*pathogenicity ; Symbiosis ; Wolbachia/metabolism ; }, abstract = {Hemolymph was characterized from Diaphorina citri adults infected with the phytopathogen, Candidatus Liberibacter asiaticus (CLas), and compared with that from uninfected psyllids. This study identified 5531 and 3220 peptides within infected and uninfected hemolymph using nano-LC-MS/MS. A reduced number of proteins were detected for D. citri and all known endosymbionts within infected hemolymph as compared to uninfected hemolymph. A large number of immune defense proteins were absent from D. citri hemolymph; however, a single recognition protein (PGRP), two serine protease inhibitors, three prophenoloxidase (proPO) enzymes, and a single serine protease in an uninfected D. citri were detected. The hemolymph is nearly devoid of nutrient storage proteins. This is the first proteomic analysis of D. citri hemolymph that also analyses the components contributed by all the endosymbionts. By comparing the contribution of each endosymbiont (CCR, CPA, and WB) in the presence and absence of CLas infection, this study offers initial insights regarding the hemolymph response to microbial community shifts associated with D. citri infection status. Our data also present potential protein targets for analysis and disruption of CLas transmission that may facilitate management of huanglongbing (HLB) caused by CLas in citrus.}, }
@article {pmid27988830, year = {2017}, author = {Espinosa, MS and Virla, EG and Cuozzo, S}, title = {Wolbachia Infections Responsible for Thelytoky in Dryinid Wasps. The Case of Gonatopus bonaerensis Virla (Hymenoptera: Dryinidae).}, journal = {Neotropical entomology}, volume = {46}, number = {4}, pages = {409-413}, pmid = {27988830}, issn = {1678-8052}, mesh = {Animals ; Female ; Male ; *Parthenogenesis ; Reproduction ; Wasps/*microbiology ; *Wolbachia/genetics/pathogenicity ; }, abstract = {We studied the occurrence of Wolbachia in the parasitoid Gonatopus bonaerensis Virla (Hymenoptera: Dryinidae). In order to verify the existence of natural infections in the parasitoid, a field survey was conducted. Identification of Wolbachia was performed on the basis of 16S rDNA, wsp_F1, and wsp_R1-sequences. After the detection of the bacteria, infected specimens of G. bonaerensis were treated with a solution of tetracycline. In Tucumán, parasitoids hold Wolbachia endosymbiont, which seems to control the wasp's reproduction in the nature turning it into thelytokous. The symbiont was identified as the Wolbachia sp. wRi strain. The cure of infected unfertilized females determined the normal arrhenotokous parthenogenesis and the production of male offspring. As a consequence of this procedure, the male of G. bonaerensis is described for the first time.}, }
@article {pmid27973604, year = {2016}, author = {Chaplinska, M and Gerritsma, S and Dini-Andreote, F and Falcao Salles, J and Wertheim, B}, title = {Bacterial Communities Differ among Drosophila melanogaster Populations and Affect Host Resistance against Parasitoids.}, journal = {PloS one}, volume = {11}, number = {12}, pages = {e0167726}, pmid = {27973604}, issn = {1932-6203}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacteria/*classification ; Disease Resistance/*genetics ; Drosophila melanogaster/*microbiology/*parasitology ; Feeding Behavior ; Female ; Founder Effect ; Genetics, Population ; Genotype ; Geography ; Host-Parasite Interactions ; Larva/parasitology ; Microbial Consortia ; *Microbiota ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; Wasps/physiology ; Wolbachia ; }, abstract = {In Drosophila, diet is considered a prominent factor shaping the associated bacterial community. However, the host population background (e.g. genotype, geographical origin and founder effects) is a factor that may also exert a significant influence and is often overlooked. To test for population background effects, we characterized the bacterial communities in larvae of six genetically differentiated and geographically distant D. melanogaster lines collected from natural populations across Europe. The diet for these six lines had been identical for ca. 50 generations, thus any differences in the composition of the microbiome originates from the host populations. We also investigated whether induced shifts in the microbiome-in this case by controlled antibiotic administration-alters the hosts' resistance to parasitism. Our data revealed a clear signature of population background on the diversity and composition of D. melanogaster microbiome that differed across lines, even after hosts had been maintained at the same diet and laboratory conditions for over 4 years. In particular, the number of bacterial OTUs per line ranged from 8 to 39 OTUs. Each line harboured 2 to 28 unique OTUs, and OTUs that were highly abundant in some lines were entirely missing in others. Moreover, we found that the response to antibiotic treatment differed among the lines and significantly altered the host resistance to the parasitoid Asobara tabida in one of the six lines. Wolbachia, a widespread intracellular endosymbiont associated with parasitoid resistance, was lacking in this line, suggesting that other components of the Drosophila microbiome caused a change in host resistance. Collectively, our results revealed that lines that originate from different population backgrounds show significant differences in the established Drosophila microbiome, outpacing the long-term effect of diet. Perturbations on these naturally assembled microbiomes to some degree influenced the hosts' resistance against natural parasites.}, }
@article {pmid27965647, year = {2016}, author = {Whitaker, MR and Salzman, S and Sanders, J and Kaltenpoth, M and Pierce, NE}, title = {Microbial Communities of Lycaenid Butterflies Do Not Correlate with Larval Diet.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1920}, pmid = {27965647}, issn = {1664-302X}, abstract = {Herbivores possess many counteradaptations to plant defenses, and a growing body of research describes the role of symbiotic gut bacteria in mediating herbivorous diets among insects. However, persistent bacterial symbioses have not been found in Lepidoptera, despite the fact that perhaps 99% of the species in this order are herbivorous. We surveyed bacterial communities in the guts of larvae from 31 species of lycaenid butterflies whose caterpillars had diets ranging from obligate carnivory to strict herbivory. Contrary to our expectations, we found that the bacterial communities of carnivorous and herbivorous caterpillars do not differ in richness, diversity, or composition. Many of the observed bacterial genera are commonly found in soil and plant surfaces, and we detected known homopteran endosymbionts in the guts of homopterophagous species, suggesting that larvae acquire gut bacteria from their food and environment. These results indicate that lycaenid butterflies do not rely on specific bacterial symbioses to mediate their diverse diets, and provide further evidence of taxonomically depauperate bacterial communities among Lepidoptera.}, }
@article {pmid27965627, year = {2016}, author = {Wang, GH and Sun, BF and Xiong, TL and Wang, YK and Murfin, KE and Xiao, JH and Huang, DW}, title = {Bacteriophage WO Can Mediate Horizontal Gene Transfer in Endosymbiotic Wolbachia Genomes.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1867}, pmid = {27965627}, issn = {1664-302X}, support = {T32 HL007974/HL/NHLBI NIH HHS/United States ; }, abstract = {Phage-mediated horizontal gene transfer (HGT) is common in free-living bacteria, and many transferred genes can play a significant role in their new bacterial hosts. However, there are few reports concerning phage-mediated HGT in endosymbionts (obligate intracellular bacteria within animal or plant hosts), such as Wolbachia. The Wolbachia-infecting temperate phage WO can actively shift among Wolbachia genomes and has the potential to mediate HGT between Wolbachia strains. In the present study, we extend previous findings by validating that the phage WO can mediate transfer of non-phage genes. To do so, we utilized bioinformatic, phylogenetic, and molecular analyses based on all sequenced Wolbachia and phage WO genomes. Our results show that the phage WO can mediate HGT between Wolbachia strains, regardless of whether the transferred genes originate from Wolbachia or other unrelated bacteria.}, }
@article {pmid27965582, year = {2016}, author = {Arp, AP and Hunter, WB and Pelz-Stelinski, KS}, title = {Annotation of the Asian Citrus Psyllid Genome Reveals a Reduced Innate Immune System.}, journal = {Frontiers in physiology}, volume = {7}, number = {}, pages = {570}, pmid = {27965582}, issn = {1664-042X}, abstract = {Citrus production worldwide is currently facing significant losses due to citrus greening disease, also known as Huanglongbing. The citrus greening bacteria, Candidatus Liberibacter asiaticus (CLas), is a persistent propagative pathogen transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Hemipterans characterized to date lack a number of insect immune genes, including those associated with the Imd pathway targeting Gram-negative bacteria. The D. citri draft genome was used to characterize the immune defense genes present in D. citri. Predicted mRNAs identified by screening the published D. citri annotated draft genome were manually searched using a custom database of immune genes from previously annotated insect genomes. Toll and JAK/STAT pathways, general defense genes Dual oxidase, Nitric oxide synthase, prophenoloxidase, and cellular immune defense genes were present in D. citri. In contrast, D. citri lacked genes for the Imd pathway, most antimicrobial peptides, 1,3-β-glucan recognition proteins (GNBPs), and complete peptidoglycan recognition proteins. These data suggest that D. citri has a reduced immune capability similar to that observed in A. pisum, P. humanus, and R. prolixus. The absence of immune system genes from the D. citri genome may facilitate CLas infections, and is possibly compensated for by their relationship with their microbial endosymbionts.}, }
@article {pmid27965151, year = {2017}, author = {Takeshita, K and Kikuchi, Y}, title = {Riptortus pedestris and Burkholderia symbiont: an ideal model system for insect-microbe symbiotic associations.}, journal = {Research in microbiology}, volume = {168}, number = {3}, pages = {175-187}, doi = {10.1016/j.resmic.2016.11.005}, pmid = {27965151}, issn = {1769-7123}, mesh = {Animals ; Biological Evolution ; Burkholderia/growth &amp; development/*physiology ; Heteroptera/anatomy &amp; histology/*microbiology/physiology ; Intestines/*microbiology ; Microbiota ; *Symbiosis ; }, abstract = {A number of insects establish symbiotic associations with beneficial microorganisms in various manners. The bean bug Riptortus pedestris and allied stink bugs possess an environmentally acquired Burkholderia symbiont in their midgut crypts. Unlike other insect endosymbionts, the Burkholderia symbiont is easily culturable and genetically manipulatable outside the host. In conjunction with the experimental advantages of the host insect, the Riptortus-Burkholderia symbiosis is an ideal model system for elucidating the molecular bases underpinning insect-microbe symbioses, which opens a new window in the research field of insect symbiosis. This review summarizes current knowledge of this system and discusses future perspectives.}, }
@article {pmid27955622, year = {2016}, author = {Vorburger, C and Rouchet, R}, title = {Are aphid parasitoids locally adapted to the prevalence of defensive symbionts in their hosts?.}, journal = {BMC evolutionary biology}, volume = {16}, number = {1}, pages = {271}, pmid = {27955622}, issn = {1471-2148}, mesh = {*Adaptation, Physiological ; Animals ; Aphids/genetics/*microbiology/*parasitology/physiology ; Bacterial Physiological Phenomena ; Enterobacteriaceae/*physiology ; Female ; France ; Switzerland ; *Symbiosis ; Wasps/*physiology ; }, abstract = {BACKGROUND: Insect parasitoids are under strong selection to overcome their hosts' defences. In aphids, resistance to parasitoids is largely determined by the presence or absence of protective endosymbionts such as Hamiltonella defensa. Hence, parasitoids may become locally adapted to the prevalence of this endosymbiont in their host populations. To address this, we collected isofemale lines of the aphid parasitoid Lysiphlebus fabarum from 17 sites in Switzerland and France, at which we also estimated the frequency of infection with H. defensa as well as other bacterial endosymbionts in five important aphid host species. The parasitoids' ability to overcome H. defensa-mediated resistance was then quantified by estimating their parasitism success on a single aphid clone (Aphis fabae fabae) that was either uninfected or experimentally infected with one of three different isolates of H. defensa.<br><br>RESULTS: The five aphid species (Aphis fabae fabae, A. f. cirsiiacanthoides, A. hederae, A. ruborum, A. urticata) differed strongly in the relative frequencies of infection with different bacterial endosymbionts, but there was also geographic variation in symbiont prevalence. Specifically, the frequency of infection with H. defensa ranged from 22 to 47&#xa0;% when averaged across species. Parasitoids from sites with a high prevalence of H. defensa tended to be more infective on aphids possessing H. defensa, but this relationship was not significant, thus providing no conclusive evidence that L. fabarum is locally adapted to the occurrence of H. defensa. On the other hand, we observed a strong interaction between parasitoid line and H. defensa isolate on parasitism success, indicative of a high specificity of symbiont-conferred resistance.<br><br>CONCLUSIONS: This study is the first, to our knowledge, to test for local adaptation of parasitoids to the frequency of defensive symbionts in their hosts. While it yielded useful information on the occurrence of facultative endosymbionts in several important host species of L. fabarum, it provided no clear evidence that parasitoids from sites with a high prevalence of H. defensa are better able to overcome H. defensa-conferred resistance. The strong genetic specificity in their interaction suggests that it may be more important for parasitoids to adapt to the particular strains of H. defensa in their host populations than to the general prevalence of this symbiont, and it highlights the important role symbionts can play in mediating host-parasitoid coevolution.}, }
@article {pmid27935594, year = {2017}, author = {Li, SJ and Ahmed, MZ and Lv, N and Shi, PQ and Wang, XM and Huang, JL and Qiu, BL}, title = {Plantmediated horizontal transmission of Wolbachia between whiteflies.}, journal = {The ISME journal}, volume = {11}, number = {4}, pages = {1019-1028}, pmid = {27935594}, issn = {1751-7370}, mesh = {Animals ; Cucumis sativus/microbiology ; Hemiptera/*microbiology ; Host-Pathogen Interactions ; Multilocus Sequence Typing ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Vigna/microbiology ; Wolbachia/genetics/*physiology ; }, abstract = {Maternal transmission is the main transmission pathway of facultative bacterial endosymbionts, but phylogenetically distant insect hosts harbor closely related endosymbionts, suggesting that horizontal transmission occurs in nature. Here we report the first case of plant-mediated horizontal transmission of Wolbachia between infected and uninfected Bemisia tabaci AsiaII7 whiteflies. After infected whiteflies fed on cotton leaves, Wolbachia was visualized, both in the phloem vessels and in some novel 'reservoir' spherules along the phloem by fluorescence in situ hybridization using Wolbachia-specific 16S rRNA probes and transmission electron microscopy. Wolbachia persisted in the plant leaves for at least 50 days. When the Wolbachia-free whiteflies fed on the infected plant leaves, the majority of them became infected with the symbiont and vertically transmitted it to their progeny. Multilocus sequence typing and sequencing of the wsp (Wolbachia surface protein) gene confirmed that the sequence type of Wolbachia in the donor whiteflies, cotton phloem and the recipient whiteflies are all identical (sequence type 388). These results were replicated using cowpea and cucumber plants, suggesting that horizontal transmission is also possible through other plant species. Our findings may help explain why Wolbachia bacteria are so abundant in arthropods, and suggest that in some species, Wolbachia may be maintained in populations by horizontal transmission.}, }
@article {pmid27930295, year = {2016}, author = {Leclercq, S and Thézé, J and Chebbi, MA and Giraud, I and Moumen, B and Ernenwein, L and Grève, P and Gilbert, C and Cordaux, R}, title = {Birth of a W sex chromosome by horizontal transfer of Wolbachia bacterial symbiont genome.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {52}, pages = {15036-15041}, pmid = {27930295}, issn = {1091-6490}, mesh = {Animals ; Biological Evolution ; Crosses, Genetic ; Cytoplasm/metabolism ; Female ; *Gene Transfer, Horizontal ; *Genome, Bacterial ; Genotype ; Isopoda/microbiology ; Male ; Microscopy, Electron, Transmission ; Phylogeny ; *Sex Chromosomes ; Sex Determination Processes ; Sex Ratio ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {Sex determination is a fundamental developmental pathway governing male and female differentiation, with profound implications for morphology, reproductive strategies, and behavior. In animals, sex differences between males and females are generally determined by genetic factors carried by sex chromosomes. Sex chromosomes are remarkably variable in origin and can differ even between closely related species, indicating that transitions occur frequently and independently in different groups of organisms. The evolutionary causes underlying sex chromosome turnover are poorly understood, however. Here we provide evidence indicating that Wolbachia bacterial endosymbionts triggered the evolution of new sex chromosomes in the common pillbug Armadillidium vulgare We identified a 3-Mb insert of a feminizing Wolbachia genome that was recently transferred into the pillbug nuclear genome. The Wolbachia insert shows perfect linkage to the female sex, occurs in a male genetic background (i.e., lacking the ancestral W female sex chromosome), and is hemizygous. Our results support the conclusion that the Wolbachia insert is now acting as a female sex-determining region in pillbugs, and that the chromosome carrying the insert is a new W sex chromosome. Thus, bacteria-to-animal horizontal genome transfer represents a remarkable mechanism underpinning the birth of sex chromosomes. We conclude that sex ratio distorters, such as Wolbachia endosymbionts, can be powerful agents of evolutionary transitions in sex determination systems in animals.}, }
@article {pmid27929353, year = {2017}, author = {Buse, HY and Schaefer, FW and Rice, EW}, title = {Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae.}, journal = {Acta microbiologica et immunologica Hungarica}, volume = {64}, number = {1}, pages = {17-36}, pmid = {27929353}, issn = {1217-8950}, support = {EPA999999/ImEPA/Intramural EPA/United States ; }, mesh = {Amoeba/*growth &amp; development/physiology ; Francisella/*growth &amp; development ; Fresh Water/*microbiology/*parasitology ; Legionella pneumophila/growth &amp; development ; Microbial Viability ; Temperature ; }, abstract = {Transmission of Francisella tularensis, the etiologic agent of tularemia, has been associated with various water sources. Survival of many waterborne pathogens within free-living amoeba (FLA) is well documented; however, the role of amoebae in the environmental persistence of F. tularensis is unclear. In this study, axenic FLA cultures of Acanthamoeba castellanii, Acanthamoeba polyphaga, and Vermamoeba vermiformis were each inoculated with virulent strains of F. tularensis (Types A and B), the attenuated live vaccine strain, and Francisella novicida. Experimental parameters included low and high multiplicity of infection and incubation temperatures of 25 and 30 °C for 0-10 days. Francisella spp. survival was enhanced by the presence of FLA; however, bacterial growth and protozoa infectivity were not observed. In contrast, co-infections of A. polyphaga and Legionella pneumophila, used as an amoeba pathogen control, resulted in bacterial proliferation, cytopathic effects, and amoebal lysis. Collectively, even though short-term incubation with FLA was beneficial, the long-term effects on Francisella survival are unknown, especially given the expenditure of available amoebal derived nutrients and the fastidious nature of Francisella spp. These factors have clear implications for the role of FLA in Francisella environmental persistence.}, }
@article {pmid27902872, year = {2017}, author = {Manzano-Marín, A and Szabó, G and Simon, JC and Horn, M and Latorre, A}, title = {Happens in the best of subfamilies: establishment and repeated replacements of co-obligate secondary endosymbionts within Lachninae aphids.}, journal = {Environmental microbiology}, volume = {19}, number = {1}, pages = {393-408}, doi = {10.1111/1462-2920.13633}, pmid = {27902872}, issn = {1462-2920}, mesh = {Animals ; Aphids/*microbiology/physiology ; Buchnera/classification/genetics/*isolation &amp; purification/physiology ; Phylogeny ; Serratia/classification/genetics/*isolation &amp; purification/physiology ; *Symbiosis ; }, abstract = {Virtually all aphids maintain an obligate mutualistic symbiosis with bacteria from the Buchnera genus, which produce essential nutrients for their aphid hosts. Most aphids from the Lachninae subfamily have been consistently found to house additional endosymbionts, mainly Serratia symbiotica. This apparent dependence on secondary endosymbionts was proposed to have been triggered by the loss of the riboflavin biosynthetic capability by Buchnera in the Lachninae last common ancestor. However, an integral large-scale analysis of secondary endosymbionts in the Lachninae is still missing, hampering the interpretation of the evolutionary and genomic analyses of these endosymbionts. Here, we analysed the endosymbionts of selected representatives from seven different Lachninae genera and nineteen species, spanning four tribes, both by FISH (exploring the symbionts' morphology and tissue tropism) and 16S rRNA gene sequencing. We demonstrate that all analysed aphids possess dual symbiotic systems, and while most harbour S. symbiotica, some have undergone symbiont replacement by other phylogenetically-distinct bacterial taxa. We found that these secondary associates display contrasting cell shapes and tissue tropism, and some appear to be lineage-specific. We propose a scenario for symbiont establishment in the Lachninae, followed by changes in the symbiont's tissue tropism and symbiont replacement events, thereby highlighting the extraordinary versatility of host-symbiont interactions.}, }
@article {pmid27902358, year = {2016}, author = {Zhang, G and Etebari, K and Asgari, S}, title = {Wolbachia suppresses cell fusing agent virus in mosquito cells.}, journal = {The Journal of general virology}, volume = {97}, number = {12}, pages = {3427-3432}, doi = {10.1099/jgv.0.000653}, pmid = {27902358}, issn = {1465-2099}, mesh = {Aedes/*microbiology/physiology/*virology ; Animals ; Cell Fusion ; Cell Line ; Flavivirus/*physiology ; *Virus Replication ; Wolbachia/*physiology ; }, abstract = {The genus Flavivirus contains a large number of positive-sense ssRNA viruses. While some are transmitted by mosquitoes or other arthropods and are pathogenic to humans and animals (e.g. dengue and Zika viruses), some are insect-specific and do not replicate in vertebrate cells. These are known as insect-specific flaviviruses (ISFs). Cell fusing agent virus (CFAV) was the first described ISF, which was detected in an Aedes aegypti cell line, Aag2. Here, we investigated the effect of Wolbachia, a widespread endosymbiont of many insect species, that is known to block replication of several pathogenic flaviviruses, on CFAV. Our results demonstrated that, in mosquito cells, Wolbachia vastly suppresses replication of CFAV, with significantly less CFAV viral interfering small RNAs produced in the cells. However, removal of Wolbachia with tetracycline led to increased CFAV replication. These results suggest that Wolbachia is also able to suppress an ISF.}, }
@article {pmid27895889, year = {2016}, author = {Lu, HL and Chang, CC and Wilson, AC}, title = {Amino acid transporters implicated in endocytosis of Buchnera during symbiont transmission in the pea aphid.}, journal = {EvoDevo}, volume = {7}, number = {}, pages = {24}, pmid = {27895889}, issn = {2041-9139}, abstract = {BACKGROUND: Many insects host their obligate, maternally transmitted symbiotic bacteria in specialized cells called bacteriocytes. One of the best-studied insect nutritional endosymbioses is that of the aphid and its endosymbiont, Buchnera aphidicola. Aphids and Buchnera are metabolically and developmentally integrated, but the molecular mechanisms underlying Buchnera transmission and coordination with aphid development remain largely unknown. Previous work using electron microscopy to study aphid asexual embryogenesis has revealed that Buchnera transmission involves exocytosis from a maternal bacteriocyte followed by endocytotic uptake by a blastula. While the importance of exo- and endocytic cellular processes for symbiont transmission is clear, the molecular mechanisms that regulate these processes are not known. Here, we shed light on the molecular mechanisms that regulate Buchnera transmission and developmental integration.<br><br>RESULTS: We present the developmental atlas of ACYPI000536 and ACYPI008904 mRNAs during asexual embryogenesis in the pea aphid, Acyrthosiphon pisum. Immediately before Buchnera invasion, transcripts of both genes were detected by whole-mount in situ hybridization in the posterior syncytial nuclei of late blastula embryos. Following Buchnera invasion, expression of both genes was identified in the region occupied by Buchnera throughout embryogenesis. Notably during Buchnera migration, expression of both genes was not concomitant with the entirety of the bacterial mass but rather expression colocalized with Buchnera in the anterior region of the bacterial mass. In addition, we found that ACYPI000536 was expressed in nuclei at the leading edge of the bacterial mass, joining the bacterial mass in subsequent developmental stages. Finally, quantitative reverse transcription real-time PCR suggested that early in development both transcripts were maternally provisioned to embryos.<br><br>CONCLUSIONS: We venture that ACYPI000536 and ACYPI008904 function as nutrient sensors at the site of symbiont invasion to facilitate TOR-pathway-mediated endocytosis of Buchnera by the aphid blastula. Our data support earlier reports of bacteriocyte determination involving a two-step recruitment process but suggest that the second wave of recruitment occurs earlier than previously described. Finally, our work highlights that bacteriocyte-enriched amino acid transporter paralogs have additionally been retained to play novel developmental roles in both symbiont recruitment and bacteriome development.}, }
@article {pmid27895657, year = {2016}, author = {Kanakala, S and Ghanim, M}, title = {Implication of the Whitefly Bemisia tabaci Cyclophilin B Protein in the Transmission of Tomato yellow leaf curl virus.}, journal = {Frontiers in plant science}, volume = {7}, number = {}, pages = {1702}, pmid = {27895657}, issn = {1664-462X}, abstract = {Tomato yellow leaf curl virus (TYLCV) is a single-stranded (ssDNA) begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention, and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB) in the transmission of TYLCV protein was investigated. Cyclophilins are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs, and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV-infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci.}, }
@article {pmid27894847, year = {2017}, author = {Santos-Silva, MM and Melo, P and Santos, N and Antunes, S and Duarte, LR and Ferrolho, J and Milhano, N and Santos, PT and Domingos, A and Santos, AS}, title = {PCR screening of tick-borne agents in sensitive conservation areas, Southeast Portugal.}, journal = {Molecular and cellular probes}, volume = {31}, number = {}, pages = {42-45}, doi = {10.1016/j.mcp.2016.11.005}, pmid = {27894847}, issn = {1096-1194}, mesh = {Animals ; Geography ; Lynx/parasitology ; Polymerase Chain Reaction/*methods ; Portugal ; Ticks/*genetics ; }, abstract = {The Southeast region of Portugal, particularly the Guadiana valley, is currently the reintroduction territory of Lynx pardinus (Iberian lynx), one of the most endangered felids in the world that is only found in the Iberian Peninsula. Over the last century, populations have declined, placing L. pardinus at extremely high risk of extinction in the wild and relying on reintroduction projects. Among the aspects taken into account in the establishment of new populations is the sanitary status of the selected habitats, especially concerning infectious diseases, including tick-borne pathogens (TBPs). This study presents the results of TBPs survey on ticks collected at sensitive conservation areas of Southeast Portugal. From 2012 to 2014, 231 ticks obtained from vegetation, sympatric domestic and wild animals were submitted for analysis. The presence of Babesia spp., Cytauxzoon spp., Theileria spp., Hepatozoon spp., Anaplasma spp., Ehrlichia spp., Candidatus Neoehrlichia mikurensis, among other Anaplasmataceae, and Coxiella burnetii were investigated by PCR. Six tick species were recorded, Dermacentor marginatus (n = 13/5.6%), Hyalomma lusitanicum (n = 175/75.8%), Ixodes ricinus (n = 4/1.7%), Rhipicephalus bursa (n = 7/3.0%), R. pusillus (n = 21/9.1%) and R. sanguineus sensu lato (n = 11/4.8%). The molecular screening confirmed the presence of two tick-borne pathogens, C. burnetii (N = 34) and Anaplasma platys (N = 1), and one tick-endosymbiont, Candidatus Midichloria mitochondrii (N = 45). The results obtained provide new information on the circulation of ticks and TBPs with potential veterinary importance in Iberian lynx habitat.}, }
@article {pmid27881553, year = {2016}, author = {Bennuru, S and Cotton, JA and Ribeiro, JM and Grote, A and Harsha, B and Holroyd, N and Mhashilkar, A and Molina, DM and Randall, AZ and Shandling, AD and Unnasch, TR and Ghedin, E and Berriman, M and Lustigman, S and Nutman, TB}, title = {Stage-Specific Transcriptome and Proteome Analyses of the Filarial Parasite Onchocerca volvulus and Its Wolbachia Endosymbiont.}, journal = {mBio}, volume = {7}, number = {6}, pages = {}, pmid = {27881553}, issn = {2150-7511}, support = {ZIA AI000512/AI/NIAID NIH HHS/United States ; R21 AI126466/AI/NIAID NIH HHS/United States ; R24 AG042328/AG/NIA NIH HHS/United States ; T32 AI007180/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; 098051/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Onchocerca volvulus/chemistry/*genetics/*growth &amp; development ; *Proteome ; *Symbiosis ; *Transcriptome ; Wolbachia/chemistry/*genetics/*growth &amp; development ; }, abstract = {UNLABELLED: Onchocerciasis (river blindness) is a neglected tropical disease that has been successfully targeted by mass drug treatment programs in the Americas and small parts of Africa. Achieving the long-term goal of elimination of onchocerciasis, however, requires additional tools, including drugs, vaccines, and biomarkers of infection. Here, we describe the transcriptome and proteome profiles of the major vector and the human host stages (L1, L2, L3, molting L3, L4, adult male, and adult female) of Onchocerca volvulus along with the proteome of each parasitic stage and of its Wolbachia endosymbiont (wOv). In so doing, we have identified stage-specific pathways important to the parasite's adaptation to its human host during its early development. Further, we generated a protein array that, when screened with well-characterized human samples, identified novel diagnostic biomarkers of O. volvulus infection and new potential vaccine candidates. This immunomic approach not only demonstrates the power of this postgenomic discovery platform but also provides additional tools for onchocerciasis control programs.<br><br>IMPORTANCE: The global onchocerciasis (river blindness) elimination program will have to rely on the development of new tools (drugs, vaccines, biomarkers) to achieve its goals by 2025. As an adjunct to the completed genomic sequencing of O.&#xa0;volvulus, we used a comprehensive proteomic and transcriptomic profiling strategy to gain a comprehensive understanding of both the vector-derived and human host-derived parasite stages. In so doing, we have identified proteins and pathways that enable novel drug targeting studies and the discovery of novel vaccine candidates, as well as useful biomarkers of active infection.}, }
@article {pmid27872949, year = {2017}, author = {Guidolin, AS and Cônsoli, FL}, title = {Symbiont Diversity of Aphis (Toxoptera) citricidus (Hemiptera: Aphididae) as Influenced by Host Plants.}, journal = {Microbial ecology}, volume = {73}, number = {1}, pages = {201-210}, pmid = {27872949}, issn = {1432-184X}, mesh = {Animals ; Aphids/*microbiology ; Biodiversity ; Buchnera/genetics/*isolation &amp; purification ; Enterobacteriaceae/genetics/*isolation &amp; purification ; Proteobacteria/genetics/*isolation &amp; purification ; Symbiosis ; }, abstract = {Aphids are well known for their association with endosymbiont bacteria. Almost all aphids harbor Buchnera aphidicola as an obligate symbiont and several other bacteria as facultative symbionts. Associations of facultative symbionts and aphids are quite variable in terms of diversity and prevalence across aphid species. Facultative symbionts can have a major impact on aphid bioecological traits. A number of factors shape the outcome of the facultative symbiont-aphid association, including aphid clone, bacterial genotype, geography, and host plant association. The effects of host plant on aphid-facultative symbiont associations are the least understood. We performed deep sequencing of the bacterial community associated with field populations of the oligophagous aphid Aphis (Toxoptera) citricidus collected from different host plants. We demonstrate that (i) A. citricidus has low symbiont diversity, (ii) symbiont diversity is affected by host plant, and (iii) host plants affect the relative abundance of the obligate symbiont Buchnera and an unknown genus of Enterobacteriaceae.}, }
@article {pmid27869792, year = {2016}, author = {Choi, YJ and Tyagi, R and McNulty, SN and Rosa, BA and Ozersky, P and Martin, J and Hallsworth-Pepin, K and Unnasch, TR and Norice, CT and Nutman, TB and Weil, GJ and Fischer, PU and Mitreva, M}, title = {Genomic diversity in Onchocerca volvulus and its Wolbachia endosymbiont.}, journal = {Nature microbiology}, volume = {2}, number = {}, pages = {16207}, pmid = {27869792}, issn = {2058-5276}, support = {//Wellcome Trust/United Kingdom ; R01 AI081803/AI/NIAID NIH HHS/United States ; R01 GM097435/GM/NIGMS NIH HHS/United States ; U54 HG003079/HG/NHGRI NIH HHS/United States ; }, mesh = {Africa, Western ; Animals ; Ecuador ; Gene Flow ; *Genetic Variation ; Genotype ; Onchocerca volvulus/*classification/*genetics/isolation &amp; purification/microbiology ; Phylogeography ; Uganda ; Wolbachia/*classification/*genetics ; }, abstract = {Ongoing elimination efforts have altered the global distribution of Onchocerca volvulus, the agent of river blindness, and further population restructuring is expected as efforts continue. Therefore, a better understanding of population genetic processes and their effect on biogeography is needed to support elimination goals. We describe O. volvulus genome variation in 27 isolates from the early 1990s (before widespread mass treatment) from four distinct locales: Ecuador, Uganda, the West African forest and the West African savanna. We observed genetic substructuring between Ecuador and West Africa and between the West African forest and savanna bioclimes, with evidence of unidirectional gene flow from savanna to forest strains. We identified forest:savanna-discriminatory genomic regions and report a set of ancestry informative loci that can be used to differentiate between forest, savanna and admixed isolates, which has not previously been possible. We observed mito-nuclear discordance possibly stemming from incomplete lineage sorting. The catalogue of the nuclear, mitochondrial and endosymbiont DNA variants generated in this study will support future basic and translational onchocerciasis research, with particular relevance for ongoing control programmes, and boost efforts to characterize drug, vaccine and diagnostic targets.}, }
@article {pmid27869790, year = {2016}, author = {Cotton, JA and Bennuru, S and Grote, A and Harsha, B and Tracey, A and Beech, R and Doyle, SR and Dunn, M and Hotopp, JC and Holroyd, N and Kikuchi, T and Lambert, O and Mhashilkar, A and Mutowo, P and Nursimulu, N and Ribeiro, JM and Rogers, MB and Stanley, E and Swapna, LS and Tsai, IJ and Unnasch, TR and Voronin, D and Parkinson, J and Nutman, TB and Ghedin, E and Berriman, M and Lustigman, S}, title = {The genome of Onchocerca volvulus, agent of river blindness.}, journal = {Nature microbiology}, volume = {2}, number = {}, pages = {16216}, pmid = {27869790}, issn = {2058-5276}, support = {DP2 OD007372/OD/NIH HHS/United States ; R01 AI078314/AI/NIAID NIH HHS/United States ; T32 AI007180/AI/NIAID NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Genome, Bacterial ; *Genome, Helminth ; Onchocerca volvulus/*genetics ; Onchocerciasis, Ocular/*parasitology ; Wolbachia/genetics ; }, abstract = {Human onchocerciasis is a serious neglected tropical disease caused by the filarial nematode Onchocerca volvulus that can lead to blindness and chronic disability. Control of the disease relies largely on mass administration of a single drug, and the development of new drugs and vaccines depends on a better knowledge of parasite biology. Here, we describe the chromosomes of O. volvulus and its Wolbachia endosymbiont. We provide the highest-quality sequence assembly for any parasitic nematode to date, giving a glimpse into the evolution of filarial parasite chromosomes and proteomes. This resource was used to investigate gene families with key functions that could be potentially exploited as targets for future drugs. Using metabolic reconstruction of the nematode and its endosymbiont, we identified enzymes that are likely to be essential for O. volvulus viability. In addition, we have generated a list of proteins that could be targeted by Federal-Drug-Agency-approved but repurposed drugs, providing starting points for anti-onchocerciasis drug development.}, }
@article {pmid27867371, year = {2016}, author = {Serra, V and Fokin, SI and Castelli, M and Basuri, CK and Nitla, V and Verni, F and Sandeep, BV and Kalavati, C and Petroni, G}, title = {"Candidatus Gortzia shahrazadis", a Novel Endosymbiont of Paramecium multimicronucleatum and a Revision of the Biogeographical Distribution of Holospora-Like Bacteria.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1704}, pmid = {27867371}, issn = {1664-302X}, abstract = {Holospora spp. and "Candidatus Gortzia infectiva", known as Holospora-like bacteria (HLB), are commonly found as nuclear endosymbionts of ciliates, especially the Paramecium genus. HLB are related by phylogenetic relationships, morphological features, and life-cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF). In this paper we describe a novel species belonging to the "Ca. Gortzia" genus, detected in P. multimicronucleatum, a ciliate for which infection by an HLB has not been reported, discovered in India. This novel endosymbiont shows unusual and surprising features with respect to other HLB, such as large variations in IF morphology and the occasional ability to reproduce in the host cytoplasm. We propose the name of "Candidatus Gortzia shahrazadis" for this novel HLB. Moreover, we report two additional species of HLB from Indian Paramecium populations: "Ca. Gortzia infectiva" (from P. jenningsi), and H. obtusa (from P. caudatum); the latter is the first record of Holospora from a tropical country. Although tropical, we retrieved H. obtusa at an elevation of 706 m corresponding to a moderate climate not unlike conditions where Holospora are normally found, suggesting the genus Holospora does exist in tropical countries, but restricted to higher elevations.}, }
@article {pmid27866607, year = {2016}, author = {Syed, B and M N, NP and B L, D and K, MK and S, Y and S, S}, title = {Synthesis of silver nanoparticles by endosymbiont Pseudomonas fluorescens CA 417 and their bactericidal activity.}, journal = {Enzyme and microbial technology}, volume = {95}, number = {}, pages = {128-136}, doi = {10.1016/j.enzmictec.2016.10.004}, pmid = {27866607}, issn = {1879-0909}, mesh = {Anti-Bacterial Agents/*metabolism/*pharmacology ; Biotechnology ; Coffea/microbiology ; Endophytes/classification/metabolism ; Green Chemistry Technology ; Humans ; Metal Nanoparticles/*chemistry/ultrastructure ; Microbial Sensitivity Tests ; Nanotechnology ; Pseudomonas fluorescens/classification/*metabolism ; Silver/*chemistry/*pharmacology ; }, abstract = {The present study emphasizes on biogenic synthesis of silver nanoparticles and their bactericidal activity against human and phytopathogens. Nanoparticle synthesis was performed using endosymbiont Pseudomonas fluorescens CA 417 inhabiting Coffea arabica L. Synthesized nanoparticles were characterized using hyphenated spectroscopic techniques such as UV-vis spectroscopy which revealed maximum absorption 425nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the possible functional groups mediating and stabilizing silver nanoparticles with predominant peaks occurring at 3346 corresponding to hydroxyl group, 1635 corresponding carbonyl group and 680 to aromatic group. X-ray diffraction (XRD) analysis revealed the Bragg's diffraction pattern with distinct peaks at 38° 44°, 64° and 78° revealing the face-centered cubic (fcc) metallic crystal corresponding to the (111), (200), (220) and (311) facets of the crystal planes at 2θ angle. The energy dispersive X-ray spectroscopy (EDS) analysis revealed presence of high intense absorption peak at 3keV is a typical characteristic of nano-crystalline silver which confirmed the presence of elemental silver. TEM analysis revealed the size of the nanoparticles to be in the range 5-50nm with polydisperse nature of synthesized nanoparticles bearing myriad shapes. The particle size determined by Dynamic light scattering (DLS) method revealed average size to be 20.66nm. The synthesized silver nanoparticles exhibited significant antibacterial activity against panel of test pathogens. The results showed Klebsiella pneumoniae (MTCC 7407) and Xanthomonas campestris to be more sensitive among the test human pathogen and phyto-pathogen respectively. The study also reports synergistic effect of silver nanoparticles in combination with kanamycin which displayed increased fold activity up to 58.3% against Klebsiella pneumoniae (MTCC 7407). The results of the present investigation are promising enough and attribute towards growing scientific knowledge on development of new antimicrobial agents to combat drug resistant microorganisms. The study provides insight on emerging role of endophytes towards reduction of metal salts to synthesize nanoparticles.}, }
@article {pmid27862998, year = {2017}, author = {Adam, N and Erler, T and Kallenbach, M and Kaltenpoth, M and Kunert, G and Baldwin, IT and Schuman, MC}, title = {Sex ratio of mirid populations shifts in response to hostplant co-infestation or altered cytokinin signaling .}, journal = {Journal of integrative plant biology}, volume = {59}, number = {1}, pages = {44-59}, pmid = {27862998}, issn = {1744-7909}, support = {293926/ERC_/European Research Council/International ; }, mesh = {Animals ; Cytokinins/*metabolism ; Female ; Hemiptera/microbiology/*physiology ; Host-Parasite Interactions ; Male ; Nutritional Physiological Phenomena ; Oviposition ; Plant Diseases/*parasitology ; Population Dynamics ; Reproduction ; *Sex Ratio ; *Signal Transduction ; Symbiosis ; Tobacco/*parasitology ; Wolbachia/physiology ; }, abstract = {Herbivore species sharing a host plant often compete. In this study, we show that host plant-mediated interaction between two insect herbivores - a generalist and a specialist - results in a sex ratio shift of the specialist's offspring. We studied demographic parameters of the specialist Tupiocoris notatus (Hemiptera: Miridae) when co-infesting the host plant Nicotiana attenuata (Solanaceae) with the generalist leafhopper Empoasca sp. (Hemiptera: Cicadellidae). We show that the usually female-biased sex ratio of T. notatus shifts toward a higher male proportion in the offspring on plants co-infested by Empoasca sp. This sex ratio change did not occur after oviposition, nor is it due differential mortality of female and male nymphs. Based on pyrosequencing and PCR of bacterial 16S rRNA amplicons, we concluded that sex ratio shifts were unlikely to be due to infection with Wolbachia or other known sex ratio-distorting endosymbionts. Finally, we used transgenic lines of N. attenuata to evaluate if the sex ratio shift could be mediated by changes in general or specialized host plant metabolites. We found that the sex ratio shift occurred on plants deficient in two cytokinin receptors (irCHK2/3). Thus, cytokinin-regulated traits can alter the offspring sex ratio of the specialist T. notatus.}, }
@article {pmid27862540, year = {2017}, author = {Meseguer, AS and Manzano-Marín, A and Coeur d'Acier, A and Clamens, AL and Godefroid, M and Jousselin, E}, title = {Buchnera has changed flatmate but the repeated replacement of co-obligate symbionts is not associated with the ecological expansions of their aphid hosts.}, journal = {Molecular ecology}, volume = {26}, number = {8}, pages = {2363-2378}, doi = {10.1111/mec.13910}, pmid = {27862540}, issn = {1365-294X}, mesh = {Animals ; Aphids/*microbiology ; *Biological Evolution ; Buchnera/*genetics ; Genome, Bacterial ; High-Throughput Nucleotide Sequencing ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Serratia/*genetics ; Species Specificity ; *Symbiosis ; }, abstract = {Symbiotic associations with bacteria have facilitated important evolutionary transitions in insects and resulted in long-term obligate interactions. Recent evidence suggests that these associations are not always evolutionarily stable and that symbiont replacement, and/or supplementation of an obligate symbiosis by an additional bacterium, has occurred during the history of many insect groups. Yet, the factors favouring one symbiont over another in this evolutionary dynamic are not well understood; progress has been hindered by our incomplete understanding of the distribution of symbionts across phylogenetic and ecological contexts. While many aphids are engaged into an obligate symbiosis with a single Gammaproteobacterium, Buchnera aphidicola, in species of the Lachninae subfamily, this relationship has evolved into a 'ménage à trois', in which Buchnera is complemented by a cosymbiont, usually Serratia symbiotica. Using deep sequencing of 16S rRNA bacterial genes from 128 species of Cinara (the most diverse Lachninae genus), we reveal a highly dynamic dual symbiotic system in this aphid lineage. Most species host both Serratia and Buchnera but, in several clades, endosymbionts related to Sodalis, Erwinia or an unnamed member of the Enterobacteriaceae have replaced Serratia. Endosymbiont genome sequences from four aphid species confirm that these coresident symbionts fulfil essential metabolic functions not ensured by Buchnera. We further demonstrate through comparative phylogenetic analyses that cosymbiont replacement is not associated with the adaptation of aphids to new ecological conditions. We propose that symbiont succession was driven by factors intrinsic to the phenomenon of endosymbiosis, such as rapid genome deterioration or competitive interactions between bacteria with similar metabolic capabilities.}, }
@article {pmid27861576, year = {2016}, author = {Cihlář, J and Füssy, Z and Horák, A and Oborník, M}, title = {Evolution of the Tetrapyrrole Biosynthetic Pathway in Secondary Algae: Conservation, Redundancy and Replacement.}, journal = {PloS one}, volume = {11}, number = {11}, pages = {e0166338}, pmid = {27861576}, issn = {1932-6203}, mesh = {*Biological Evolution ; *Biosynthetic Pathways/genetics ; Cryptophyta/classification/genetics/*metabolism ; Diatoms/classification/genetics/*metabolism ; Dinoflagellida/classification/genetics/*metabolism ; Gene Expression Profiling ; Heme/metabolism ; Phylogeny ; Porphobilinogen Synthase/genetics/metabolism ; Tetrapyrroles/*metabolism ; }, abstract = {Tetrapyrroles such as chlorophyll and heme are indispensable for life because they are involved in energy fixation and consumption, i.e. photosynthesis and oxidative phosphorylation. In eukaryotes, the tetrapyrrole biosynthetic pathway is shaped by past endosymbioses. We investigated the origins and predicted locations of the enzymes of the heme pathway in the chlorarachniophyte Bigelowiella natans, the cryptophyte Guillardia theta, the "green" dinoflagellate Lepidodinium chlorophorum, and three dinoflagellates with diatom endosymbionts ("dinotoms"): Durinskia baltica, Glenodinium foliaceum and Kryptoperidinium foliaceum. Bigelowiella natans appears to contain two separate heme pathways analogous to those found in Euglena gracilis; one is predicted to be mitochondrial-cytosolic, while the second is predicted to be plastid-located. In the remaining algae, only plastid-type tetrapyrrole synthesis is present, with a single remnant of the mitochondrial-cytosolic pathway, a ferrochelatase of G. theta putatively located in the mitochondrion. The green dinoflagellate contains a single pathway composed of mostly rhodophyte-origin enzymes, and the dinotoms hold two heme pathways of apparently plastidal origin. We suggest that heme pathway enzymes in B. natans and L. chlorophorum share a predominantly rhodophytic origin. This implies the ancient presence of a rhodophyte-derived plastid in the chlorarachniophyte alga, analogous to the green dinoflagellate, or an exceptionally massive horizontal gene transfer.}, }
@article {pmid27859964, year = {2017}, author = {Pontieri, L and Schmidt, AM and Singh, R and Pedersen, JS and Linksvayer, TA}, title = {Artificial selection on ant female caste ratio uncovers a link between female-biased sex ratios and infection by Wolbachia endosymbionts.}, journal = {Journal of evolutionary biology}, volume = {30}, number = {2}, pages = {225-234}, doi = {10.1111/jeb.13012}, pmid = {27859964}, issn = {1420-9101}, mesh = {Animals ; Female ; *Ants/parasitology ; *Sex Ratio ; *Symbiosis ; *Wolbachia/pathogenicity ; }, abstract = {Social insect sex and caste ratios are well-studied targets of evolutionary conflicts, but the heritable factors affecting these traits remain unknown. To elucidate these factors, we carried out a short-term artificial selection study on female caste ratio in the ant Monomorium pharaonis. Across three generations of bidirectional selection, we observed no response for caste ratio, but sex ratios rapidly became more female-biased in the two replicate high selection lines and less female-biased in the two replicate low selection lines. We hypothesized that this rapid divergence for sex ratio was caused by changes in the frequency of infection by the heritable bacterial endosymbiont Wolbachia, because the initial breeding stock varied for Wolbachia infection, and Wolbachia is known to cause female-biased sex ratios in other insects. Consistent with this hypothesis, the proportions of Wolbachia-infected colonies in the selection lines changed rapidly, mirroring the sex ratio changes. Moreover, the estimated effect of Wolbachia on sex ratio (~13% female bias) was similar in colonies before and during artificial selection, indicating that this Wolbachia effect is likely independent of the effects of artificial selection on other heritable factors. Our study provides evidence for the first case of endosymbiont sex ratio manipulation in a social insect.}, }
@article {pmid27859175, year = {2016}, author = {Rothacher, L and Ferrer-Suay, M and Vorburger, C}, title = {Bacterial endosymbionts protect aphids in the field and alter parasitoid community composition.}, journal = {Ecology}, volume = {97}, number = {7}, pages = {1712-1723}, doi = {10.1890/15-2022.1}, pmid = {27859175}, issn = {0012-9658}, mesh = {Animals ; Aphids/*microbiology/physiology ; Enterobacteriaceae/*physiology ; Genotype ; *Symbiosis ; Wasps/*physiology ; }, abstract = {It has become increasingly evident that many organisms rely on microbial symbionts for defense against natural enemies, but the ecological importance of defensive symbionts for natural communities still needs to be investigated. A well-known example is Hamiltonella defensa, a heritable endosymbiotic bacterium commonly found in aphids. Laboratory experiments have shown that H. defensa strongly protects aphids against parasitic wasps (parasitoids), although this protection is not equally effective against different species of parasitoids, or even different genotypes of the same species. These results suggest that H. defensa plays an important role in reducing aphid mortality by parasitoids and presumably affects the community composition of parasitoids relying on aphids as a resource. However, there is little evidence that this is indeed the case under natural conditions. We tested this in a field experiment with black bean aphids (Aphis fabae) by setting up replicated field plots with genetically identical aphids that did or did not harbor H. defensa and following their colonization by natural enemies over a growing season. We observed a clear reduction in parasitism of symbiont-protected aphids, particularly by the parasitoids posing the highest risk. However, protected aphids did not develop larger populations than unprotected ones, possibly reflecting the balancing effect of costs associated with harboring H. defensa. We also observed shifts in the parasitoid species composition on aphids protected by H. defensa, showing that defensive symbionts have the potential to alter the diversity and structure of food webs, with likely consequences for their function and stability.}, }
@article {pmid27858182, year = {2017}, author = {Qiu, L and Li, Q and Zhang, J and Chen, Y and Lin, X and Sun, C and Wang, W and Liu, H and Zhang, B}, title = {Migration of endophytic diazotroph Azorhizobium caulinodans ORS571 inside wheat (Triticum aestivum L) and its effect on microRNAs.}, journal = {Functional &amp; integrative genomics}, volume = {17}, number = {2-3}, pages = {311-319}, pmid = {27858182}, issn = {1438-7948}, mesh = {Azorhizobium caulinodans/*physiology ; MicroRNAs/*physiology ; Triticum/*physiology ; }, abstract = {Azorhizobium caulinodans ORS571, a novel rhizobium, forms endosymbionts with its nature host Sesbania rostrata, a semi-aquatic leguminous tree. Recent studies showed that A. caulinodans ORS571, as endophytic rhizobium, disseminated and colonized inside of cereal plants. However, how this rhizobium infects monocot plants and the regulatory mechanism remains unknown. MicroRNAs (miRNAs) are small, endogenous RNAs that regulate gene expression at the post-transcriptional levels. In this study, we employed laser scanning confocal microscope to monitor the pathway that rhizobium invade wheat; we also investigated the potential role of miRNAs during A. caulinodans ORS571 infecting wheat. Our results showed that gfp-labeled A. caulinodans ORS571 infected wheat root hairs and emerged lateral roots, then disseminated and colonized within roots and migrated to other plant tissues, such as stems and leaves. Endophytic rhizobium induced the aberrant expression of miRNAs in wheat with a tissue- and time-dependent manner with a peak at 12-24 h after rhizobium infection. Some miRNAs, such as miR167 and miR393 responded more in roots than that in shoots. In contrast, miR171 responded higher in shoots than that in roots. These results suggested that miRNAs could be responsive to A. caulinodans ORS571 infection and played important role in plant growth, nutrient metabolisms, and wheat-rhizobium interactions.}, }
@article {pmid27853562, year = {2016}, author = {Quigley, KM and Willis, BL and Bay, LK}, title = {Maternal effects and Symbiodinium community composition drive differential patterns in juvenile survival in the coral Acropora tenuis.}, journal = {Royal Society open science}, volume = {3}, number = {10}, pages = {160471}, pmid = {27853562}, issn = {2054-5703}, abstract = {Coral endosymbionts in the dinoflagellate genus Symbiodinium are known to impact host physiology and have led to the evolution of reef-building, but less is known about how symbiotic communities in early life-history stages and their interactions with host parental identity shape the structure of coral communities on reefs. Differentiating the roles of environmental and biological factors driving variation in population demographic processes, particularly larval settlement, early juvenile survival and the onset of symbiosis is key to understanding how coral communities are structured and to predicting how they are likely to respond to climate change. We show that maternal effects (that here include genetic and/or effects related to the maternal environment) can explain nearly 24% of variation in larval settlement success and 5-17% of variation in juvenile survival in an experimental study of the reef-building scleractinian coral, Acropora tenuis. After 25 days on the reef, Symbiodinium communities associated with juvenile corals differed significantly between high mortality and low mortality families based on estimates of taxonomic richness, composition and relative abundance of taxa. Our results highlight that maternal and familial effects significantly explain variation in juvenile survival and symbiont communities in a broadcast-spawning coral, with Symbiodinium type A3 possibly a critical symbiotic partner during this early life stage.}, }
@article {pmid27840574, year = {2016}, author = {Beltrame-Botelho, IT and Talavera-López, C and Andersson, B and Grisard, EC and Stoco, PH}, title = {A Comparative In Silico Study of the Antioxidant Defense Gene Repertoire of Distinct Lifestyle Trypanosomatid Species.}, journal = {Evolutionary bioinformatics online}, volume = {12}, number = {}, pages = {263-275}, pmid = {27840574}, issn = {1176-9343}, abstract = {Kinetoplastids are an ancestral group of protists that contains free-living species and parasites with distinct mechanisms in response to stress. Here, we compared genes involved in antioxidant defense (AD), proposing an evolution model among trypanosomatids. All genes were identified in Bodo saltans, suggesting that AD mechanisms have evolved prior to adaptation for parasitic lifestyles. While most of the monoxenous and dixenous parasites revealed minor differences from B. saltans, the endosymbiont-bearing species have an increased number of genes. The absence of these genes was mainly observed in the extracellular parasites of the genera Phytomonas and Trypanosoma. In trypanosomes, a distinction was observed between stercorarian and salivarian parasites, except for Trypanosoma rangeli. Our analyses indicate that the variability of AD among trypanosomatids at the genomic level is not solely due to the geographical isolation, being mainly related to specific adaptations of their distinct biological cycles within insect vectors and to a parasitism of a wide range of hosts.}, }
@article {pmid27837024, year = {2016}, author = {Sumiya, N and Fujiwara, T and Era, A and Miyagishima, SY}, title = {Chloroplast division checkpoint in eukaryotic algae.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {47}, pages = {E7629-E7638}, pmid = {27837024}, issn = {1091-6490}, mesh = {Cell Cycle ; Cell Nucleus/genetics/metabolism ; Chloroplasts/*physiology ; Plant Proteins/genetics/*metabolism ; Rhodophyta/*physiology ; Up-Regulation ; }, abstract = {Chloroplasts evolved from a cyanobacterial endosymbiont. It is believed that the synchronization of endosymbiotic and host cell division, as is commonly seen in existing algae, was a critical step in establishing the permanent organelle. Algal cells typically contain one or only a small number of chloroplasts that divide once per host cell cycle. This division is based partly on the S-phase-specific expression of nucleus-encoded proteins that constitute the chloroplast-division machinery. In this study, using the red alga Cyanidioschyzon merolae, we show that cell-cycle progression is arrested at the prophase when chloroplast division is blocked before the formation of the chloroplast-division machinery by the overexpression of Filamenting temperature-sensitive (Fts) Z2-1 (Fts72-1), but the cell cycle progresses when chloroplast division is blocked during division-site constriction by the overexpression of either FtsZ2-1 or a dominant-negative form of dynamin-related protein 5B (DRP5B). In the cells arrested in the prophase, the increase in the cyclin B level and the migration of cyclin-dependent kinase B (CDKB) were blocked. These results suggest that chloroplast division restricts host cell-cycle progression so that the cell cycle progresses to the metaphase only when chloroplast division has commenced. Thus, chloroplast division and host cell-cycle progression are synchronized by an interactive restriction that takes place between the nucleus and the chloroplast. In addition, we observed a similar pattern of cell-cycle arrest upon the blockage of chloroplast division in the glaucophyte alga Cyanophora paradoxa, raising the possibility that the chloroplast division checkpoint contributed to the establishment of the permanent organelle.}, }
@article {pmid27835948, year = {2016}, author = {Morales, J and Kokkori, S and Weidauer, D and Chapman, J and Goltsman, E and Rokhsar, D and Grossman, AR and Nowack, EC}, title = {Development of a toolbox to dissect host-endosymbiont interactions and protein trafficking in the trypanosomatid Angomonas deanei.}, journal = {BMC evolutionary biology}, volume = {16}, number = {1}, pages = {247}, pmid = {27835948}, issn = {1471-2148}, mesh = {Animals ; Base Sequence ; Betaproteobacteria/drug effects/metabolism ; Cinnamates/pharmacology ; Genetic Vectors/metabolism ; Genome, Protozoan ; Genomics/*methods ; Gentamicins/pharmacology ; Green Fluorescent Proteins/metabolism ; Homologous Recombination/drug effects/genetics ; Hygromycin B/analogs &amp; derivatives/pharmacology ; Mutagenesis, Insertional/genetics ; Protein Transport/drug effects ; Protozoan Proteins/metabolism ; Reproducibility of Results ; Sequence Analysis, DNA ; Subcellular Fractions/drug effects/metabolism ; *Symbiosis/drug effects/genetics ; Transcriptome/drug effects/genetics ; Trypanosomatina/drug effects/*genetics/*microbiology ; }, abstract = {BACKGROUND: Bacterial endosymbionts are found across the eukaryotic kingdom and profoundly impacted eukaryote evolution. In many endosymbiotic associations with vertically inherited symbionts, highly complementary metabolic functions encoded by host and endosymbiont genomes indicate integration of metabolic processes between the partner organisms. While endosymbionts were initially expected to exchange only metabolites with their hosts, recent evidence has demonstrated that also host-encoded proteins can be targeted to the bacterial symbionts in various endosymbiotic systems. These proteins seem to participate in regulating symbiont growth and physiology. However, mechanisms required for protein targeting and the specific endosymbiont targets of these trafficked proteins are currently unexplored owing to a lack of molecular tools that enable functional studies of endosymbiotic systems.<br><br>RESULTS: Here we show that the trypanosomatid Angomonas deanei, which harbors a &#x3b2;-proteobacterial endosymbiont, is readily amenable to genetic manipulation. Its rapid growth, availability of full genome and transcriptome sequences, ease of transfection, and high frequency of homologous recombination have allowed us to stably integrate transgenes into the A. deanei nuclear genome, efficiently generate null mutants, and elucidate protein localization by heterologous expression of a fluorescent protein fused to various putative targeting signals. Combining these novel tools with proteomic analysis was key for demonstrating the routing of a host-encoded protein to the endosymbiont, suggesting the existence of a specific endosymbiont-sorting machinery in A. deanei.<br><br>CONCLUSIONS: After previous reports from plants, insects, and a cercozoan amoeba we found here that also in A. deanei, i.e. a member of a fourth eukaryotic supergroup, host-encoded proteins can be routed to the bacterial endosymbiont. This finding adds further evidence to our view that the targeting of host proteins is a general strategy of eukaryotes to gain control over and interact with a bacterial endosymbiont. The molecular resources reported here establish A. deanei as a time and cost efficient reference system that allows for a rigorous dissection of host-symbiont interactions that have been, and are still being shaped over evolutionary time. We expect this system to greatly enhance our understanding of the biology of endosymbiosis.}, }
@article {pmid27834740, year = {2016}, author = {Speijer, D}, title = {Being right on Q: shaping eukaryotic evolution.}, journal = {The Biochemical journal}, volume = {473}, number = {22}, pages = {4103-4127}, pmid = {27834740}, issn = {1470-8728}, mesh = {Animals ; Biological Evolution ; Electron Transport Complex I/metabolism ; Eukaryota/*metabolism ; Mitochondria/metabolism ; Peroxisomes/metabolism ; Reactive Oxygen Species/metabolism ; }, abstract = {Reactive oxygen species (ROS) formation by mitochondria is an incompletely understood eukaryotic process. I proposed a kinetic model [BioEssays (2011) 33: , 88-94] in which the ratio between electrons entering the respiratory chain via FADH2 or NADH (the F/N ratio) is a crucial determinant of ROS formation. During glucose breakdown, the ratio is low, while during fatty acid breakdown, the ratio is high (the longer the fatty acid, the higher is the ratio), leading to higher ROS levels. Thus, breakdown of (very-long-chain) fatty acids should occur without generating extra FADH2 in mitochondria. This explains peroxisome evolution. A potential ROS increase could also explain the absence of fatty acid oxidation in long-lived cells (neurons) as well as other eukaryotic adaptations, such as dynamic supercomplex formation. Effective combinations of metabolic pathways from the host and the endosymbiont (mitochondrion) allowed larger varieties of substrates (with different F/N ratios) to be oxidized, but high F/N ratios increase ROS formation. This might have led to carnitine shuttles, uncoupling proteins, and multiple antioxidant mechanisms, especially linked to fatty acid oxidation [BioEssays (2014) 36: , 634-643]. Recent data regarding peroxisome evolution and their relationships with mitochondria, ROS formation by Complex I during ischaemia/reperfusion injury, and supercomplex formation adjustment to F/N ratios strongly support the model. I will further discuss the model in the light of experimental findings regarding mitochondrial ROS formation.}, }
@article {pmid27830372, year = {2017}, author = {Corsaro, D and Wylezich, C and Walochnik, J and Venditti, D and Michel, R}, title = {Molecular identification of bacterial endosymbionts of Sappinia strains.}, journal = {Parasitology research}, volume = {116}, number = {2}, pages = {549-558}, pmid = {27830372}, issn = {1432-1955}, mesh = {Amoebozoa/*microbiology/physiology ; Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {The genus Sappinia comprises free-living amoebae occurring worldwide in a variety of habitats such as soils, plant matter and freshwater ponds, but also animal faeces, and includes at present three species, S. pedata, S. diploidea and S. platani. The genus is potentially pathogenic, as indicated by the identification of S. pedata in a case of human amoebic encephalitis. Electron microscopy studies on some strains already revealed intracellular bacteria in Sappinia. In the current study, we performed 16S ribosomal RNA gene (rDNA) analysis of these bacterial endosymbionts. We first inferred relationships among Sappinia strains on the basis of 18S rDNA, demonstrating that S. pedata emerged as sister to a larger clade including S. diploidea, S. platani and a few 'S. diploidea-like' strains. Thus, bacterial 16S rDNA was searched for in representative strains of each Sappinia species/subgroup. We found that Sappinia strains were associated to distinct species of Flavobacterium or Pedobacter (phylum Bacteroidetes). These appear to be distributed following the amoebal host subgroups, and are not directly related to other Bacteroidetes species known as interacting with free-living amoebae. While all the endosymbionts' close relatives are known to grow on agar, bacteriological media inoculated with amoebal extracts remained negative. Overall, results indicate that the recovered bacteria are likely specific obligate endosymbionts of Sappinia species. Further studies, including additional amoebal strains and deep morphological and molecular analyses, will be necessary to confirm this hypothesis.}, }
@article {pmid27824282, year = {2017}, author = {Sathiyanarayanan, G and Saibaba, G and Kiran, GS and Yang, YH and Selvin, J}, title = {Marine sponge-associated bacteria as a potential source for polyhydroxyalkanoates.}, journal = {Critical reviews in microbiology}, volume = {43}, number = {3}, pages = {294-312}, doi = {10.1080/1040841X.2016.1206060}, pmid = {27824282}, issn = {1549-7828}, mesh = {Animals ; Bacteria/*metabolism ; Biotechnology/methods ; Polyhydroxyalkanoates/chemistry/*metabolism ; Porifera/*microbiology ; }, abstract = {Marine sponges are filter feeding porous animals and usually harbor a remarkable array of microorganisms in their mesohyl tissues as transient and resident endosymbionts. The marine sponge-microbial interactions are highly complex and, in some cases, the relationships are thought to be truly symbiotic or mutualistic rather than temporary associations resulting from sponge filter-feeding activity. The marine sponge-associated bacteria are fascinating source for various biomolecules that are of potential interest to several biotechnological industries. In recent times, a particular attention has been devoted to bacterial biopolymer (polyesters) such as intracellular polyhydroxyalkanoates (PHAs) produced by sponge-associated bacteria. Bacterial PHAs act as an internal reserve for carbon and energy and also are a tremendous alternative for fossil fuel-based polymers mainly due to their eco-friendliness. In addition, PHAs are produced when the microorganisms are under stressful conditions and this biopolymer synthesis might be exhibited as one of the survival mechanisms of sponge-associated or endosymbiotic bacteria which exist in a highly competitive and stressful sponge-mesohyl microenvironment. In this review, we have emphasized the industrial prospects of marine bacteria for the commercial production of PHAs and special importance has been given to marine sponge-associated bacteria as a potential resource for PHAs.}, }
@article {pmid27822559, year = {2016}, author = {Apprill, A and Weber, LG and Santoro, AE}, title = {Distinguishing between Microbial Habitats Unravels Ecological Complexity in Coral Microbiomes.}, journal = {mSystems}, volume = {1}, number = {5}, pages = {}, pmid = {27822559}, issn = {2379-5077}, abstract = {The diverse prokaryotic communities associated with reef-building corals may provide important ecological advantages to their threatened hosts. The consistency of relationships between corals and specific prokaryotes, however, is debated, and the locations where microbially mediated processes occur in the host are not resolved. Here, we examined how the prokaryotic associates of five common Caribbean corals with different evolutionary and ecological traits differ across mucus and tissue habitats. We used physical and chemical separation of coral mucus and tissue and sequencing of partial small-subunit rRNA genes of bacteria and archaea from these samples to demonstrate that coral tissue and mucus harbor unique reservoirs of prokaryotes, with 23 to 49% and 31 to 56% of sequences exclusive to the tissue and mucus habitats, respectively. Across all coral species, we found that 46 tissue- and 22 mucus-specific microbial members consistently associated with the different habitats. Sequences classifying as "Candidatus Amoebophilus," Bacteroidetes-affiliated intracellular symbionts of amoebae, emerged as previously unrecognized tissue associates of three coral species. This study demonstrates how coral habitat differentiation enables highly resolved examination of ecological interactions between corals and their associated microorganisms and identifies previously unrecognized tissue and mucus associates of Caribbean corals for future targeted study. IMPORTANCE This study demonstrates that coral tissue or mucus habitats structure the microbiome of corals and that separation of these habitats facilitates identification of consistent microbial associates. Using this approach, we demonstrated that sequences related to "Candidatus Amoebophilus," recognized intracellular symbionts of amoebae, were highly associated with the tissues of Caribbean corals and possibly endosymbionts of a protistan host within corals, adding a further degree of intricacy to coral holobiont symbioses. Examining specific habitats within complex hosts such as corals is useful for targeting important microbial associations that may otherwise be masked by the sheer microbial diversity associated with all host habitats.}, }
@article {pmid27821770, year = {2016}, author = {DeLong, JP and Al-Ameeli, Z and Duncan, G and Van Etten, JL and Dunigan, DD}, title = {Predators catalyze an increase in chloroviruses by foraging on the symbiotic hosts of zoochlorellae.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {48}, pages = {13780-13784}, pmid = {27821770}, issn = {1091-6490}, support = {K23 RR015535/RR/NCRR NIH HHS/United States ; P20 GM103427/GM/NIGMS NIH HHS/United States ; P30 GM103509/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aquatic Organisms/genetics ; Chlorella/*genetics/growth &amp; development/virology ; Copepoda/virology ; Food Chain ; Host-Pathogen Interactions/*genetics ; Phycodnaviridae/*genetics/physiology ; *Predatory Behavior ; Symbiosis/genetics ; }, abstract = {Virus population growth depends on contacts between viruses and their hosts. It is often unclear how sufficient contacts are made between viruses and their specific hosts to generate spikes in viral abundance. Here, we show that copepods, acting as predators, can bring aquatic viruses and their algal hosts into contact. Specifically, predation of the protist Paramecium bursaria by copepods resulted in a >100-fold increase in the number of chloroviruses in 1 d. Copepod predation can be seen as an ecological "catalyst" by increasing contacts between chloroviruses and their hosts, zoochlorellae (endosymbiotic algae that live within paramecia), thereby facilitating viral population growth. When feeding, copepods passed P. bursaria through their digestive tract only partially digested, releasing endosymbiotic algae that still supported viral reproduction and resulting in a virus population spike. A simple predator-prey model parameterized for copepods consuming protists generates cycle periods for viruses consistent with those observed in natural ponds. Food webs are replete with similar symbiotic organisms, and we suspect the predator catalyst mechanism is capable of generating blooms for other endosymbiont-targeting viruses.}, }
@article {pmid27819272, year = {2016}, author = {Li, K and Chen, H and Jiang, J and Li, X and Xu, J and Ma, Y}, title = {Diversity of bacteriome associated with Phlebotomus chinensis (Diptera: Psychodidae) sand flies in two wild populations from China.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {36406}, pmid = {27819272}, issn = {2045-2322}, support = {SC1 AI112786/AI/NIAID NIH HHS/United States ; SC1 GM109326/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Biodiversity ; Ecosystem ; Enterobacteriaceae/classification/genetics/isolation &amp; purification ; *Microbiota ; Phylogeny ; Principal Component Analysis ; Pseudomonas/classification/genetics/isolation &amp; purification ; Psychodidae/*microbiology ; RNA, Ribosomal, 16S/isolation &amp; purification/metabolism ; Rickettsia/classification/genetics/isolation &amp; purification ; Sequence Analysis, DNA ; Wolbachia/classification/genetics/isolation &amp; purification ; }, abstract = {Sand fly Phlebotomus chinensis is a primary vector of transmission of visceral leishmaniasis in China. The sand flies have adapted to various ecological niches in distinct ecosystems. Characterization of the microbial structure and function will greatly facilitate the understanding of the sand fly ecology, which would provide critical information for developing intervention strategy for sand fly control. In this study we compared the bacterial composition between two populations of Ph. chinensis from Henan and Sichuan, China. The phylotypes were taxonomically assigned to 29 genera of 19 families in 9 classes of 5 phyla. The core bacteria include Pseudomonas and enterobacteria, both are shared in the sand flies in the two regions. Interestingly, the endosymbionts Wolbachia and Rickettsia were detected only in Henan, while the Rickettsiella and Diplorickettsia only in Sichuan. The intracellular bacteria Rickettsia, Rickettsiella and Diplorickettsia were reported for the first time in sand flies. The influence of sex and feeding status on the microbial structure was also detected in the two populations. The findings suggest that the ecological diversity of sand fly in Sichuan and Henan may contribute to shaping the structure of associated microbiota. The structural classification paves the way to function characterization of the sand fly associated microbiome.}, }
@article {pmid27816636, year = {2017}, author = {Quispe, CF and Esmael, A and Sonderman, O and McQuinn, M and Agarkova, I and Battah, M and Duncan, GA and Dunigan, DD and Smith, TPL and De Castro, C and Speciale, I and Ma, F and Van Etten, JL}, title = {Characterization of a new chlorovirus type with permissive and non-permissive features on phylogenetically related algal strains.}, journal = {Virology}, volume = {500}, number = {}, pages = {103-113}, pmid = {27816636}, issn = {1096-0341}, support = {K23 RR015535/RR/NCRR NIH HHS/United States ; P20 GM103427/GM/NIGMS NIH HHS/United States ; P20 RR016469/RR/NCRR NIH HHS/United States ; P30 GM103509/GM/NIGMS NIH HHS/United States ; }, mesh = {Base Sequence ; Chlorella/*virology ; Genome, Viral ; Molecular Sequence Data ; Phycodnaviridae/classification/*genetics/isolation &amp; purification/physiology ; *Phylogeny ; RNA, Viral/chemistry/genetics ; Viral Proteins/genetics/metabolism ; Virus Replication ; }, abstract = {A previous report indicated that prototype chlorovirus PBCV-1 replicated in two Chlorella variabilis algal strains, NC64A and Syngen 2-3, that are ex-endosymbionts isolated from the protozoan Paramecium bursaria. Surprisingly, plaque-forming viruses on Syngen 2-3 lawns were often higher than on NC64A lawns from indigenous water samples. These differences led to the discovery of viruses that exclusively replicate in Syngen 2-3 cells, named Only Syngen (OSy) viruses. OSy-NE5, the prototype virus for the proposed new species, had a linear dsDNA genome of 327kb with 44-nucleotide-long, incompletely base-paired, covalently closed hairpin ends. Each hairpin structure was followed by an identical 2612 base-paired inverted sequence after which the DNA sequence diverged. OSy-NE5 encoded 357 predicted CDSs and 13 tRNAs. Interestingly, OSy-NE5 attached to and initiated infection in NC64A cells but infectious progeny viruses were not produced; thus OSy-NE5 replication in NC64A is blocked at some later stage of replication.}, }
@article {pmid27814642, year = {2017}, author = {Degli Esposti, M}, title = {The long story of mitochondrial DNA and respiratory complex I.}, journal = {Frontiers in bioscience (Landmark edition)}, volume = {22}, number = {4}, pages = {722-731}, doi = {10.2741/4512}, pmid = {27814642}, issn = {2768-6698}, mesh = {Animals ; DNA, Mitochondrial/*genetics/*metabolism ; Electron Transport Complex I/chemistry/*genetics/*metabolism ; Evolution, Molecular ; Genes, Mitochondrial ; Humans ; Mitochondrial Proteins/chemistry/genetics/metabolism ; Phylogeny ; Protein Subunits ; }, abstract = {This article examines the long story of the relationship between mitochondrial DNA (mtDNA) and respiratory complex I, NADH:Ubiquinone Oxidoreductase, from its beginning in the genome of the bacterial endosymbiont which then evolved into the mitochondria of our cells. The story begins with the evolution of ancient forms of bacterial complex I into the Nuo14 complex I that was present in the alpha proteobacterial ancestor of mitochondria. The story then becomes complicated in the diversity of eukaryotic organisms that are currently recognized. Therefore, it does not have a clear end, because currently available information shows different situations of metabolic adaptation and gene loss, indicating cases of de-evolution of the original protonmotive complex into a system that may fundamentally assist [FeFe]-hydrogenases in re-oxidising metabolically produced NADH under anaerobic conditions. The history of complex I is thus a never ending story of molecular and physiological evolution producing new perspectives for studying the enzyme complex that occupies the largest proportion of mitochondrial DNA.}, }
@article {pmid27813204, year = {2016}, author = {Palomares-Rius, JE and Archidona-Yuste, A and Cantalapiedra-Navarrete, C and Prieto, P and Castillo, P}, title = {Molecular diversity of bacterial endosymbionts associated with dagger nematodes of the genus Xiphinema (Nematoda: Longidoridae) reveals a high degree of phylogenetic congruence with their host.}, journal = {Molecular ecology}, volume = {25}, number = {24}, pages = {6225-6247}, doi = {10.1111/mec.13904}, pmid = {27813204}, issn = {1365-294X}, mesh = {Animals ; Burkholderiaceae/*classification ; In Situ Hybridization, Fluorescence ; Nematoda/*microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Verrucomicrobia/*classification ; }, abstract = {Bacterial endosymbionts have been detected in some groups of plant-parasitic nematodes, but few cases have been reported compared to other groups in the phylum Nematoda, such as animal-parasitic or free-living nematodes. This study was performed on a wide variety of plant-parasitic nematode families and species from different host plants and nematode populations. A total of 124 nematode populations (previously identified morphologically and molecularly) were screened for the presence of potential bacterial endosymbionts using the partial 16S rRNA gene and fluorescence in situ hybridization (FISH) and confocal microscopy. Potential bacterial endosymbionts were only detected in nematode species belonging to the genus Xiphinema and specifically in the X. americanum group. Fifty-seven partial 16S rRNA sequences were obtained from bacterial endosymbionts in this study. One group of sequences was closely related to the genus 'Candidatus Xiphinematobacter' (19 bacterial endosymbiont sequences were associated with seven nematode host species, including two that have already been described and three unknown bacterial endosymbionts). The second bacterial endosymbiont group (38 bacterial endosymbiont sequences associated with six nematode species) was related to the family Burkholderiaceae, which includes fungal and soil-plant bacterial endosymbionts. These endosymbionts were reported for the first time in the phylum Nematoda. Our findings suggest that there is a highly specific symbiotic relationship between nematode host and bacterial endosymbionts. Overall, these results were corroborated by a phylogeny of nematode host and bacterial endosymbionts that suggested that there was a high degree of phylogenetic congruence and long-term evolutionary persistence between hosts and endosymbionts.}, }
@article {pmid27807263, year = {2016}, author = {Kennedy, EV and Tonk, L and Foster, NL and Chollett, I and Ortiz, JC and Dove, S and Hoegh-Guldberg, O and Mumby, PJ and Stevens, JR}, title = {Symbiodinium biogeography tracks environmental patterns rather than host genetics in a key Caribbean reef-builder, Orbicella annularis.}, journal = {Proceedings. Biological sciences}, volume = {283}, number = {1842}, pages = {}, pmid = {27807263}, issn = {1471-2954}, mesh = {Animals ; Anthozoa/genetics/*microbiology ; Caribbean Region ; DNA, Ribosomal Spacer/genetics ; Dinoflagellida/genetics/*physiology ; Genotype ; Stress, Physiological ; *Symbiosis ; *Temperature ; }, abstract = {The physiological performance of a reef-building coral is a combined outcome of both the coral host and its algal endosymbionts, Symbiodinium While Orbicella annularis-a dominant reef-building coral in the Wider Caribbean-is known to be a flexible host in terms of the diversity of Symbiodinium types it can associate with, it is uncertain how this diversity varies across the Caribbean, and whether spatial variability in the symbiont community is related to either O. annularis genotype or environment. Here, we target the Symbiodinium-ITS2 gene to characterize and map dominant Symbiodinium hosted by O. annularis at an unprecedented spatial scale. We reveal northwest-southeast partitioning across the Caribbean, both in terms of the dominant symbiont taxa hosted and in assemblage diversity. Multivariate regression analyses incorporating a suite of environmental and genetic factors reveal that observed spatial patterns are predominantly explained by chronic thermal stress (summer temperatures) and are unrelated to host genotype. Furthermore, we were able to associate the presence of specific Symbiodinium types with local environmental drivers (for example, Symbiodinium C7 with areas experiencing cooler summers, B1j with nutrient loading and B17 with turbidity), associations that have not previously been described.}, }
@article {pmid27805069, year = {2016}, author = {Sampayo, EM and Ridgway, T and Franceschinis, L and Roff, G and Hoegh-Guldberg, O and Dove, S}, title = {Coral symbioses under prolonged environmental change: living near tolerance range limits.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {36271}, pmid = {27805069}, issn = {2045-2322}, mesh = {Adaptation, Physiological/physiology ; Animals ; Anthozoa/classification/parasitology/*physiology ; *Climate Change ; *Coral Reefs ; Dinoflagellida/physiology ; Ecosystem ; Host Specificity ; Light ; Species Specificity ; *Symbiosis ; Temperature ; }, abstract = {As climate change progresses, understanding the long-term response of corals and their endosymbionts (Symbiodinium) to prolonged environmental change is of immediate importance. Here, a total of 1152 fragments from 72 colonies of three common coral species (Stylophora pistillata, Pocillopora damicornis, Seriatopora hystrix) underwent a 32-month reciprocal depth transplantation. Genetic analysis showed that while S. hystrix maintained its generalist symbiont, some S. pistillata and P. damicornis underwent temporary changes in resident symbionts immediately after stress (transplantation; natural bleaching). These temporary changes were phylogenetically constrained to 'host-compatible' symbionts only and reversion to original symbionts occurred within 7 to 12 months, indicating long-term fidelity and stability of adult symbioses. Measurements of symbiont photo-physiology (dark adapted yield, pressure over photosystem II) and coral health (host protein, bleaching status, mortality) indicated a broad acclimatory capacity. However, this came at an apparent energetic expense as disproportionate mortality amongst symbioses that persisted outside their distribution range was observed following a natural bleaching event. As environmental changes due to climate change become more continuous in nature, sub-lethal effects linked to the existence near tolerance range limits coupled with the inability of adult coral colonies to change resident symbionts makes corals particularly susceptible to additional environmental fluctuations or stress events and reduces the resilience of coral populations.}, }
@article {pmid27804213, year = {2017}, author = {Wang, ZZ and Bing, XL and Liu, SS and Chen, XX}, title = {RNA interference of an antimicrobial peptide, Btdef, reduces Tomato yellow leaf curl China virus accumulation in the whitefly Bemisia tabaci.}, journal = {Pest management science}, volume = {73}, number = {7}, pages = {1421-1427}, doi = {10.1002/ps.4472}, pmid = {27804213}, issn = {1526-4998}, mesh = {Animals ; Begomovirus/genetics/*physiology ; Defensins/genetics/*metabolism ; Hemiptera/*immunology/microbiology/virology ; Insect Proteins/genetics/*metabolism ; Insect Vectors/virology ; Peptides/genetics/*metabolism ; Plant Diseases/*virology ; Plant Viruses/physiology ; *RNA Interference ; Rickettsia/physiology ; Symbiosis ; Tobacco/virology ; Transcription, Genetic ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored.<br><br>RESULTS: To explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies.<br><br>CONCLUSION: Our data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus-whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. &#xa9; 2016 Society of Chemical Industry.}, }
@article {pmid27795568, year = {2016}, author = {Douglas, AE}, title = {How multi-partner endosymbioses function.}, journal = {Nature reviews. Microbiology}, volume = {14}, number = {12}, pages = {731-743}, pmid = {27795568}, issn = {1740-1534}, mesh = {Amino Acids, Essential/biosynthesis/*metabolism ; Animals ; *Bacterial Physiological Phenomena ; Biological Evolution ; Biosynthetic Pathways ; Hemiptera/genetics/*microbiology/*physiology ; Phenotype ; Phylogeny ; Plants/chemistry ; *Symbiosis/genetics ; }, abstract = {Various animals are associated with specific endosymbiotic microorganisms that provide the host with essential nutrients or confer protection against natural enemies. Genomic analyses of the many endosymbioses that are found in plant sap-feeding hemipteran insects have revealed independent acquisitions - and occasional replacements - of endosymbionts, such that many of these endosymbioses involve two or more microbial partners. In this Review, I discuss how partitioning of the genetic capacity for metabolic function between different endosymbionts has sustained nutritional function in multi-partner endosymbioses, and how the phenotypic traits of these endosymbionts can be shaped by co-evolutionary interactions with both co-occurring microbial taxa and the host, which often operate over long evolutionary timescales.}, }
@article {pmid27748755, year = {2016}, author = {Marx, H and Minogue, CE and Jayaraman, D and Richards, AL and Kwiecien, NW and Siahpirani, AF and Rajasekar, S and Maeda, J and Garcia, K and Del Valle-Echevarria, AR and Volkening, JD and Westphall, MS and Roy, S and Sussman, MR and Ané, JM and Coon, JJ}, title = {A proteomic atlas of the legume Medicago truncatula and its nitrogen-fixing endosymbiont Sinorhizobium meliloti.}, journal = {Nature biotechnology}, volume = {34}, number = {11}, pages = {1198-1205}, pmid = {27748755}, issn = {1546-1696}, support = {T15 LM007359/LM/NLM NIH HHS/United States ; T32 HG002760/HG/NHGRI NIH HHS/United States ; }, mesh = {Bacterial Proteins/*metabolism ; Databases, Protein ; Medicago truncatula/*metabolism/*microbiology ; Nitrogen Fixation/*physiology ; Plant Proteins/*metabolism ; Proteome/metabolism ; Proteomics ; Sinorhizobium meliloti/*physiology ; Symbiosis/*physiology ; }, abstract = {Legumes are essential components of agricultural systems because they enrich the soil in nitrogen and require little environmentally deleterious fertilizers. A complex symbiotic association between legumes and nitrogen-fixing soil bacteria called rhizobia culminates in the development of root nodules, where rhizobia fix atmospheric nitrogen and transfer it to their plant host. Here we describe a quantitative proteomic atlas of the model legume Medicago truncatula and its rhizobial symbiont Sinorhizobium meliloti, which includes more than 23,000 proteins, 20,000 phosphorylation sites, and 700 lysine acetylation sites. Our analysis provides insight into mechanisms regulating symbiosis. We identify a calmodulin-binding protein as a key regulator in the host and assign putative roles and targets to host factors (bioactive peptides) that control gene expression in the symbiont. Further mining of this proteomic resource may enable engineering of crops and their microbial partners to increase agricultural productivity and sustainability.}, }
@article {pmid27742680, year = {2016}, author = {Szokoli, F and Castelli, M and Sabaneyeva, E and Schrallhammer, M and Krenek, S and Doak, TG and Berendonk, TU and Petroni, G}, title = {Disentangling the Taxonomy of Rickettsiales and Description of Two Novel Symbionts ("Candidatus Bealeia paramacronuclearis" and "Candidatus Fokinia cryptica") Sharing the Cytoplasm of the Ciliate Protist Paramecium biaurelia.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {24}, pages = {7236-7247}, pmid = {27742680}, issn = {1098-5336}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification/physiology ; Cytoplasm/*microbiology ; Paramecium/*microbiology/physiology ; Phylogeny ; Rickettsiaceae/classification/genetics/*isolation &amp; purification/physiology ; Symbiosis ; }, abstract = {In the past 10 years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, IN. Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium "Candidatus Bealeia paramacronuclearis" occurs in clumps and is frequently associated with the host macronucleus. With its electron-dense cytoplasm and a distinct halo surrounding the cell, it is easily distinguishable from the second smaller symbiont, "Candidatus Fokinia cryptica," whose cytoplasm is electron lucid, lacks a halo, and is always surrounded by a symbiontophorous vacuole. For molecular characterization, the small-subunit rRNA genes were sequenced and used for taxonomic assignment as well as the design of species-specific oligonucleotide probes. Phylogenetic analyses revealed that "Candidatus Bealeia paramacronuclearis" clusters with the so-called "basal" Rickettsiales, and "Candidatus Fokinia cryptica" belongs to "Candidatus Midichloriaceae." We obtained tree topologies showing a separation of Rickettsiales into at least two groups: one represented by the families Rickettsiaceae, Anaplasmataceae, and "Candidatus Midichloriaceae" (RAM clade), and the other represented by "basal Rickettsiales," including "Candidatus Bealeia paramacronuclearis." Therefore, and in accordance with recent publications, we propose to limit the order Rickettsiales to the RAM clade and to raise "basal Rickettsiales" to an independent order, Holosporales ord. nov., inside Alphaproteobacteria, which presently includes four family-level clades. Additionally, we define the family "Candidatus Hepatincolaceae" and redefine the family Holosporaceae IMPORTANCE: In this paper, we provide the characterization of two novel bacterial symbionts inhabiting the same Paramecium host (Ciliophora, Alveolata). Both symbionts belong to "traditional" Rickettsiales, one representing a new species of the genus "Candidatus Fokinia" ("Candidatus Midichloriaceae"), and the other representing a new genus of a "basal" Rickettsiales According to newly characterized sequences and to a critical revision of recent literature, we propose a taxonomic reorganization of "traditional" Rickettsiales that we split into two orders: Rickettsiales sensu stricto and Holosporales ord. nov. This work represents a critical revision, including new records of a group of symbionts frequently occurring in protists and whose biodiversity is still largely underestimated.}, }
@article {pmid27792764, year = {2016}, author = {Seo, MG and Lee, SH and Ouh, IO and Lee, GH and Goo, YK and Kim, S and Kwon, OD and Kwak, D}, title = {Molecular Detection and Genotyping of Coxiella-Like Endosymbionts in Ticks that Infest Horses in South Korea.}, journal = {PloS one}, volume = {11}, number = {10}, pages = {e0165784}, pmid = {27792764}, issn = {1932-6203}, mesh = {Animals ; Coxiella/classification/*genetics/*physiology ; *Genotyping Techniques ; Horses/*microbiology ; Phylogeny ; Republic of Korea ; Sequence Analysis, DNA ; *Symbiosis ; Ticks/*physiology ; }, abstract = {Members of the genus Coxiella can be transmitted from ticks to humans during contact with animals; Coxiella may thus spread from the infected horses or ticks to humans. In this study, the presence of Coxiella burnetii and Coxiella-like endosymbionts (CLE) in ticks found on infested horses was determined using PCR and genotyping. A total of 213 ticks were randomly collected from 51 horses (4-5 ticks per horse) raised on Jeju Island, Korea, between 2009 and 2013. All ticks were morphologically identified as adult Haemaphysalis longicornis, a predominant tick species widespread in Korea. Based on the results of nested PCR and 16S rRNA sequencing, CLE were detected in 121 (52.4%, 95% CI: 45.9-58.8) ticks. CLE 16S rRNA sequences from 9 randomly selected ticks were 100% identical. Phylogenetic analysis showed that these 9 sequences were highly similar (97.9-100%) to the sequences of clade B species, like the CLE previously described to be found in Haemaphysalis spp. This study showed that CLE are prevalent in ticks that infest horses reared on Jeju Island, and this is, to the best of our knowledge, the first study to describe CLE occurrence in ticks infesting animals reared in Korea. Because of the high prevalence of CLE in ticks found on horses, CLE transmission from ticks to other animals and humans remains a possibility. This warrants a detailed study of other hosts and regions. Considering the zoonotic potential of Coxiella, further strategic surveillance of Coxiella transmission is necessary.}, }
@article {pmid27791006, year = {2016}, author = {Qiu, D and Huang, L and Lin, S}, title = {Cryptophyte farming by symbiotic ciliate host detected in situ.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {43}, pages = {12208-12213}, pmid = {27791006}, issn = {1091-6490}, mesh = {Agriculture ; Ammonium Compounds/metabolism ; Chloroplasts/*genetics ; Ciliophora/*genetics/growth &amp; development ; Cryptophyta/*genetics/growth &amp; development ; Gene Expression Regulation ; Harmful Algal Bloom/physiology ; Membrane Transport Proteins/genetics ; Photosynthesis/genetics ; Plastids/genetics ; RNA Transport/genetics ; Symbiosis/*genetics ; }, abstract = {Protist-alga symbiosis is widespread in the ocean, but its characteristics and function in situ remain largely unexplored. Here we report the symbiosis of the ciliate Mesodinium rubrum with cryptophyte cells during a red-tide bloom in Long Island Sound. In contrast to the current notion that Mesodinium retains cryptophyte chloroplasts or organelles, our multiapproach analyses reveal that in this bloom the endosymbiotic Teleaulax amphioxeia cells were intact and expressing genes of membrane transporters, nucleus-to-cytoplasm RNA transporters, and all major metabolic pathways. Among the most highly expressed were ammonium transporters in both organisms, indicating cooperative acquisition of ammonium as a major N nutrient, and genes for photosynthesis and cell division in the cryptophyte, showing active population proliferation of the endosymbiont. We posit this as a "Mesodinium-farming-Teleaulax" relationship, a model of protist-alga symbiosis worth further investigation by metatranscriptomic technology.}, }
@article {pmid27790981, year = {2016}, author = {Brettmann, EA and Shaik, JS and Zangger, H and Lye, LF and Kuhlmann, FM and Akopyants, NS and Oschwald, DM and Owens, KL and Hickerson, SM and Ronet, C and Fasel, N and Beverley, SM}, title = {Tilting the balance between RNA interference and replication eradicates Leishmania RNA virus 1 and mitigates the inflammatory response.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {43}, pages = {11998-12005}, pmid = {27790981}, issn = {1091-6490}, support = {P30 CA091842/CA/NCI NIH HHS/United States ; R01 AI029646/AI/NIAID NIH HHS/United States ; R56 AI099364/AI/NIAID NIH HHS/United States ; UL1 TR000448/TR/NCATS NIH HHS/United States ; }, mesh = {Animals ; Antiprotozoal Agents/chemistry/metabolism/*pharmacology ; Gene Expression ; Inverted Repeat Sequences ; Leishmania braziliensis/pathogenicity/virology ; Leishmania guyanensis/pathogenicity/virology ; Leishmaniasis, Mucocutaneous/*drug therapy/parasitology/virology ; Leishmaniavirus/*drug effects/genetics/metabolism ; Macrophages/parasitology/virology ; Mice ; Oligoribonucleotides, Antisense/genetics/metabolism/*pharmacology ; RNA Interference/drug effects ; RNA, Double-Stranded/*antagonists &amp; inhibitors/genetics/metabolism ; RNA, Viral/*antagonists &amp; inhibitors/genetics/metabolism ; Symbiosis/genetics ; Toll-Like Receptor 3/genetics/metabolism ; Virus Replication/drug effects ; }, abstract = {Many Leishmania (Viannia) parasites harbor the double-stranded RNA virus Leishmania RNA virus 1 (LRV1), which has been associated with increased disease severity in animal models and humans and with drug treatment failures in humans. Remarkably, LRV1 survives in the presence of an active RNAi pathway, which in many organisms controls RNA viruses. We found significant levels (0.4 to 2.5%) of small RNAs derived from LRV1 in both Leishmania braziliensis and Leishmania guyanensis, mapping across both strands and with properties consistent with Dicer-mediated cleavage of the dsRNA genome. LRV1 lacks cis- or trans-acting RNAi inhibitory activities, suggesting that virus retention must be maintained by a balance between RNAi activity and LRV1 replication. To tilt this balance toward elimination, we targeted LRV1 using long-hairpin/stem-loop constructs similar to those effective against chromosomal genes. LRV1 was completely eliminated, at high efficiency, accompanied by a massive overproduction of LRV1-specific siRNAs, representing as much as 87% of the total. For both L. braziliensis and L. guyanensis, RNAi-derived LRV1-negative lines were no longer able to induce a Toll-like receptor 3-dependent hyperinflammatory cytokine response in infected macrophages. We demonstrate in vitro a role for LRV1 in virulence of L. braziliensis, the Leishmania species responsible for the vast majority of mucocutaneous leishmaniasis cases. These findings establish a targeted method for elimination of LRV1, and potentially of other Leishmania viruses, which will facilitate mechanistic dissection of the role of LRV1-mediated virulence. Moreover, our data establish a third paradigm for RNAi-viral relationships in evolution: one of balance rather than elimination.}, }
@article {pmid27788413, year = {2016}, author = {Zhang, J and Pan, Y and Zheng, C and Gao, X and Wei, X and Xi, J and Peng, T and Shang, Q}, title = {Rapid evolution of symbiotic bacteria populations in spirotetramat-resistant Aphis gossypii glover revealed by pyrosequencing.}, journal = {Comparative biochemistry and physiology. Part D, Genomics &amp; proteomics}, volume = {20}, number = {}, pages = {151-158}, doi = {10.1016/j.cbd.2016.10.001}, pmid = {27788413}, issn = {1878-0407}, mesh = {Animals ; Aphids/drug effects/*genetics/microbiology ; Aza Compounds/*pharmacology ; Bacteria/classification/drug effects/*genetics ; *Biological Evolution ; Computational Biology ; DNA, Ribosomal/genetics ; Gene Expression Regulation/drug effects ; High-Throughput Nucleotide Sequencing/methods ; Insect Proteins/*genetics ; Insecticide Resistance/*genetics ; Insecticides/pharmacology ; Metagenome ; Phylogeny ; Spiro Compounds/*pharmacology ; Symbiosis/*genetics ; }, abstract = {Aphis gossypii is one of the most economically important insect pests for agriculture worldwide. Aphids have developed symbiotic associations with bacterial species, which has led to morphological and molecular differences, such as body color and insecticide resistance. Adults and 3rd instar nymphs of a laboratory-selected spirotetramat-resistant strain of cotton aphid presented 579-fold and 15-fold higher resistance to spirotetramat, respectively, than a susceptible strain (Pan et al., 2015; Peng et al., 2016). In this study, we found that antibiotics, especially ampicillin and tetracycline, increased spirotetramat toxicity in resistant aphids. We also characterized all of the bacterial endosymbionts in these two clones by sequencing the 16S rRNA genes of the endosymbiont. The total reads could be clustered into 3534 operational taxonomic units (OTUs) that showed 97% similarity and belonged to six abundant phyla. Proteobacteria and Firmicutes dominated in the two strains, and the most abundant families were Enterobacteriaceae, Lactobacillaceae and Rhodobiaceae. The genera Arsenophonus, Anderseniella, Buchnera and Lactobacillus were most abundant in the susceptible strain, whereas a significant decrease in abundance of Anderseniella and a great increase in abundance of Arsenophonus and Lactobacillus were observed in the resistant strain. Certain identified species had low sequence similarity to the reported species, which indicates the possibility of novel taxa. The type and abundance of different bacterial groups varied significantly between the two strains. The insecticide selection pressure could be the reason for the observed shift in the bacteria groups. These results increase our understanding of the symbiotic relationships between bacteria and their hosts under insecticide stress and provide clues for the development of potential control techniques against this cotton aphid.}, }
@article {pmid27194398, year = {2016}, author = {Catta-Preta, CM and Dos Santos Pascoalino, B and de Souza, W and Mottram, JC and Motta, MC and Schenkman, S}, title = {Reduction of Tubulin Expression in Angomonas deanei by RNAi Modifies the Ultrastructure of the Trypanosomatid Protozoan and Impairs Division of Its Endosymbiotic Bacterium.}, journal = {The Journal of eukaryotic microbiology}, volume = {63}, number = {6}, pages = {794-803}, doi = {10.1111/jeu.12326}, pmid = {27194398}, issn = {1550-7408}, support = {MR/K019384/1/MRC_/Medical Research Council/United Kingdom ; MR/K019384/2/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Bacteria/*cytology/genetics ; Cell Division ; Protozoan Proteins/*genetics/metabolism ; RNA Interference ; *Symbiosis ; Trypanosomatina/genetics/metabolism/*microbiology/ultrastructure ; Tubulin/genetics/metabolism ; }, abstract = {In the last two decades, RNA interference pathways have been employed as a useful tool for reverse genetics in trypanosomatids. Angomonas deanei is a nonpathogenic trypanosomatid that maintains an obligatory endosymbiosis with a bacterium related to the Alcaligenaceae family. Studies of this symbiosis can help us to understand the origin of eukaryotic organelles. The recent elucidation of both the A. deanei and the bacterium symbiont genomes revealed that the host protozoan codes for the enzymes necessary for RNAi activity in trypanosomatids. Here, we tested the functionality of the RNAi machinery by transfecting cells with dsRNA to a reporter gene (green fluorescent protein), which had been previously expressed in the parasite and to α-tubulin, an endogenous gene. In both cases, protein expression was reduced by the presence of specific dsRNA, inducing, respectively, a decreased GFP fluorescence and the formation of enlarged cells with modified arrangement of subpellicular microtubules. Furthermore, symbiont division was impaired. These results indicate that the RNAi system is active in A. deanei and can be used to further explore gene function in symbiont-containing trypanosomatids and to clarify important aspects of symbiosis and cell evolution.}, }
@article {pmid27093048, year = {2016}, author = {Boulotte, NM and Dalton, SJ and Carroll, AG and Harrison, PL and Putnam, HM and Peplow, LM and van Oppen, MJ}, title = {Exploring the Symbiodinium rare biosphere provides evidence for symbiont switching in reef-building corals.}, journal = {The ISME journal}, volume = {10}, number = {11}, pages = {2693-2701}, pmid = {27093048}, issn = {1751-7370}, mesh = {Acclimatization ; Adaptation, Physiological ; Animals ; Anthozoa/genetics/*parasitology/physiology ; Coral Reefs ; Dinoflagellida/classification/genetics/*isolation &amp; purification/physiology ; Polymerase Chain Reaction ; Seawater/*parasitology ; Symbiosis ; }, abstract = {Reef-building corals possess a range of acclimatisation and adaptation mechanisms to respond to seawater temperature increases. In some corals, thermal tolerance increases through community composition changes of their dinoflagellate endosymbionts (Symbiodinium spp.), but this mechanism is believed to be limited to the Symbiodinium types already present in the coral tissue acquired during early life stages. Compelling evidence for symbiont switching, that is, the acquisition of novel Symbiodinium types from the environment, by adult coral colonies, is currently lacking. Using deep sequencing analysis of Symbiodinium rDNA internal transcribed spacer 2 (ITS2) PCR amplicons from two pocilloporid coral species, we show evidence consistent with de novo acquisition of Symbiodinium types from the environment by adult corals following two consecutive bleaching events. Most of these newly detected symbionts remained in the rare biosphere (background types occurring below 1% relative abundance), but one novel type reached a relative abundance of ~33%. Two de novo acquired Symbiodinium types belong to the thermally resistant clade D, suggesting that this switching may have been driven by consecutive thermal bleaching events. Our results are particularly important given the maternal mode of Symbiodinium transmission in the study species, which generally results in high symbiont specificity. These findings will cause a paradigm shift in our understanding of coral-Symbiodinium symbiosis flexibility and mechanisms of environmental acclimatisation in corals.}, }
@article {pmid27775698, year = {2016}, author = {König, S and Gros, O and Heiden, SE and Hinzke, T and Thürmer, A and Poehlein, A and Meyer, S and Vatin, M and Mbéguié-A-Mbéguié, D and Tocny, J and Ponnudurai, R and Daniel, R and Becher, D and Schweder, T and Markert, S}, title = {Nitrogen fixation in a chemoautotrophic lucinid symbiosis.}, journal = {Nature microbiology}, volume = {2}, number = {}, pages = {16193}, doi = {10.1038/nmicrobiol.2016.193}, pmid = {27775698}, issn = {2058-5276}, mesh = {Animals ; Bivalvia/*microbiology ; *Chemoautotrophic Growth ; Gammaproteobacteria/chemistry/genetics/metabolism/*physiology ; Gills/microbiology ; Metabolic Networks and Pathways/genetics ; *Nitrogen Fixation ; Nitrogenase/metabolism ; Oxidoreductases/genetics ; Phylogeny ; Proteome/analysis ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The shallow water bivalve Codakia orbicularis lives in symbiotic association with a sulfur-oxidizing bacterium in its gills. The endosymbiont fixes CO2 and thus generates organic carbon compounds, which support the host's growth. To investigate the uncultured symbiont's metabolism and symbiont-host interactions in detail we conducted a proteogenomic analysis of purified bacteria. Unexpectedly, our results reveal a hitherto completely unrecognized feature of the C. orbicularis symbiont's physiology: the symbiont's genome encodes all proteins necessary for biological nitrogen fixation (diazotrophy). Expression of the respective genes under standard ambient conditions was confirmed by proteomics. Nitrogenase activity in the symbiont was also verified by enzyme activity assays. Phylogenetic analysis of the bacterial nitrogenase reductase NifH revealed the symbiont's close relationship to free-living nitrogen-fixing Proteobacteria from the seagrass sediment. The C. orbicularis symbiont, here tentatively named 'Candidatus Thiodiazotropha endolucinida', may thus not only sustain the bivalve's carbon demands. C. orbicularis may also benefit from a steady supply of fixed nitrogen from its symbiont-a scenario that is unprecedented in comparable chemoautotrophic symbioses.}, }
@article {pmid27774085, year = {2016}, author = {Mori, M and Ponce-de-León, M and Peretó, J and Montero, F}, title = {Metabolic Complementation in Bacterial Communities: Necessary Conditions and Optimality.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1553}, pmid = {27774085}, issn = {1664-302X}, abstract = {Bacterial communities may display metabolic complementation, in which different members of the association partially contribute to the same biosynthetic pathway. In this way, the end product of the pathway is synthesized by the community as a whole. However, the emergence and the benefits of such complementation are poorly understood. Herein, we present a simple model to analyze the metabolic interactions among bacteria, including the host in the case of endosymbiotic bacteria. The model considers two cell populations, with both cell types encoding for the same linear biosynthetic pathway. We have found that, for metabolic complementation to emerge as an optimal strategy, both product inhibition and large permeabilities are needed. In the light of these results, we then consider the patterns found in the case of tryptophan biosynthesis in the endosymbiont consortium hosted by the aphid Cinara cedri. Using in-silico computed physicochemical properties of metabolites of this and other biosynthetic pathways, we verified that the splitting point of the pathway corresponds to the most permeable intermediate.}, }
@article {pmid27742260, year = {2016}, author = {Billiard, S and Collet, P and Ferrière, R and Méléard, S and Tran, VC}, title = {The effect of competition and horizontal trait inheritance on invasion, fixation, and polymorphism.}, journal = {Journal of theoretical biology}, volume = {411}, number = {}, pages = {48-58}, doi = {10.1016/j.jtbi.2016.10.003}, pmid = {27742260}, issn = {1095-8541}, mesh = {Adaptation, Physiological/genetics ; *Algorithms ; Animals ; Competitive Behavior ; Ecosystem ; Evolution, Molecular ; Gene Transfer, Horizontal/*genetics ; Genetics, Population ; *Models, Genetic ; Phenotype ; Polymorphism, Genetic/*genetics ; Population Density ; Population Dynamics ; Probability ; Stochastic Processes ; Time Factors ; }, abstract = {Horizontal transfer (HT) of heritable information or 'traits' (carried by genetic elements, plasmids, endosymbionts, or culture) is widespread among living organisms. Yet current ecological and evolutionary theory addressing HT is scant. We present a modeling framework for the dynamics of two populations that compete for resources and horizontally exchange (transfer) an otherwise vertically inherited trait. Competition influences individual demographics, thereby affecting population size, which feeds back on the dynamics of transfer. This feedback is captured in a stochastic individual-based model, from which we derive a general model for the contact rate, with frequency-dependent (FD) and density-dependent (DD) rates as special cases. Taking a large-population limit on the stochastic individual-level model yields a deterministic Lotka-Volterra competition system with additional terms accounting for HT. The stability analysis of this system shows that HT can revert the direction of selection: HT can drive invasion of a deleterious trait, or prevent invasion of an advantageous trait. Due to HT, invasion does not necessarily imply fixation. Two trait values may coexist in a stable polymorphism even if their invasion fitnesses have opposite signs, or both are negative. Addressing the question of how the stochasticity of individual processes influences population fluctuations, we identify conditions on competition and mode of transfer (FD versus DD) under which the stochasticity of transfer events overwhelms demographic stochasticity. Assuming that one trait is initially rare, we derive invasion and fixation probabilities and time. In the case of costly plasmids, which are transfered unilaterally, invasion is always possible if the transfer rate is large enough; under DD and for intermediate values of the transfer rate, maintenance of the plasmid in a polymorphic population is possible. In conclusion, HT interacts with ecology (competition) in non-trivial ways. Our model provides a basis to model the influence of HT on evolutionary adaptation.}, }
@article {pmid27770459, year = {2017}, author = {Marchetti, M and Clerissi, C and Yousfi, Y and Gris, C and Bouchez, O and Rocha, E and Cruveiller, S and Jauneau, A and Capela, D and Masson-Boivin, C}, title = {Experimental evolution of rhizobia may lead to either extra- or intracellular symbiotic adaptation depending on the selection regime.}, journal = {Molecular ecology}, volume = {26}, number = {7}, pages = {1818-1831}, doi = {10.1111/mec.13895}, pmid = {27770459}, issn = {1365-294X}, support = {281605/ERC_/European Research Council/International ; }, mesh = {Adaptation, Physiological/genetics ; *Biological Evolution ; Cupriavidus/*genetics ; Mimosa/*microbiology ; Plant Root Nodulation ; Plant Roots/microbiology ; Plasmids/genetics ; Ralstonia solanacearum/*genetics/physiology ; Symbiosis/*genetics ; }, abstract = {Experimental evolution is a powerful approach to study the process of adaptation to new environments, including the colonization of eukaryotic hosts. Facultative endosymbionts, including pathogens and mutualists, face changing and spatially structured environments during the symbiotic process, which impose diverse selection pressures. Here, we provide evidence that different selection regimes, involving different times spent in the plant environment, can result in either intra- or extracellular symbiotic adaptations. In previous work, we introduced the symbiotic plasmid of Cupriavidus taiwanensis, the rhizobial symbiont of Mimosa pudica, into the phytopathogen Ralstonia solanacearum and selected three variants able to form root nodules on M. pudica, two (CBM212 and CBM349) being able to rudimentarily infect nodule cells and the third one (CBM356) only capable of extracellular infection of nodules. Each nodulating ancestor was further challenged to evolve using serial ex planta-in planta cycles of either 21 (three short-cycle lineages) or 42 days (three long-cycle lineages). In this study, we compared the phenotype of the 18 final evolved clones. Evolution through short and long cycles resulted in similar adaptive paths on lineages deriving from the two intracellularly infectious ancestors, CBM212 and CBM349. In contrast, only short cycles allowed a stable acquisition of intracellular infection in lineages deriving from the extracellularly infecting ancestor, CBM356. Long cycles, instead, favoured improvement of extracellular infection. Our work highlights the importance of the selection regime in shaping desired traits during host-mediated selection experiments.}, }
@article {pmid27769655, year = {2017}, author = {Blanco, CM and Teixeira, BR and da Silva, AG and de Oliveira, RC and Strecht, L and Ogrzewalska, M and de Lemos, ERS}, title = {Microorganisms in ticks (Acari: Ixodidae) collected on marsupials and rodents from Santa Catarina, Paraná and Mato Grosso do Sul states, Brazil.}, journal = {Ticks and tick-borne diseases}, volume = {8}, number = {1}, pages = {90-98}, doi = {10.1016/j.ttbdis.2016.10.003}, pmid = {27769655}, issn = {1877-9603}, mesh = {Animals ; Babesia/genetics/*isolation &amp; purification ; Babesiosis/epidemiology/parasitology ; Bacteria/genetics/*isolation &amp; purification ; Brazil/epidemiology ; Ixodidae/classification/*microbiology ; Marsupialia/*parasitology ; Nymph/classification ; Phylogeny ; Rodentia/*parasitology ; Tick Infestations/epidemiology/parasitology/*veterinary ; }, abstract = {Information about tick fauna and monitoring of pathogen prevalences in ticks (Acari: Ixodidae) in various habitat types can enhance knowledge about the epidemiology of tick-borne pathogens in Brazil. This work shows the results of a study of tick parasitism of wild rodents and marsupials collected in seven localities in the southern part of Brazil, within Atlantic Forest and Cerrado biomes. A total of 61 ticks were collected from small mammals, and after identification to the species level, the ticks were individually tested for the presence of bacteria of the genera Rickettsia, Borrelia, family Anaplasmataceae, and protozoa of the genus Babesia. The following species of ticks were found: Amblyomma ovale Koch, 1844, Amblyomma dubitatum Neumann, 1899, Amblyomma fuscum Neumann, 1907, Ixodes aragaoi Fonseca, 1935, Ixodes fuscipes Koch, 1844, Ixodes loricatus Neumann, 1899, and Ixodes schulzei Aragão and Fonseca, 1951. Among tested ticks, no DNA of Borrelia, Babesia or Anaplasmataceae was detected. Two nymphs of A. ovale were found infected with Rickettsia bellii and four nymphs of I. aragaoi with Rickettsia sp., genetically close to Rickettsia monacensis, Rickettsia tamurae and the endosymbiont Rickettsia spp., previously found in various Ixodidae. In one nymph of A. fuscum, DNA of a novel Hepatozoon sp. was found. Additionally we provide novel tick-host associations.}, }
@article {pmid27702765, year = {2016}, author = {Fromont, C and Riegler, M and Cook, JM}, title = {Phylogeographic analyses of bacterial endosymbionts in fig homotomids (Hemiptera: Psylloidea) reveal codiversification of both primary and secondary endosymbionts.}, journal = {FEMS microbiology ecology}, volume = {92}, number = {12}, pages = {}, doi = {10.1093/femsec/fiw205}, pmid = {27702765}, issn = {1574-6941}, mesh = {Animals ; Base Composition/genetics ; Biological Evolution ; DNA, Mitochondrial/genetics ; Enterobacteriaceae/classification/genetics/isolation &amp; purification ; Evolution, Molecular ; Ficus ; Halomonadaceae/genetics/*isolation &amp; purification ; Hemiptera/*microbiology ; Phylogeny ; Phylogeography ; Symbiosis/*genetics ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {While obligate primary (P-) endosymbionts usually cospeciate with their insect hosts, less is known about codiversification of secondary (S-) endosymbionts that are generally considered facultative. Typically, insects of the superfamily Psylloidea harbour one P- (Carsonella) and at least one S-endosymbiont, thought to compensate for Carsonella genome reduction. Most codiversification studies have used phylogenies of psyllids and their endosymbionts across and within host families or genera, but few have explored patterns within species. We focussed on P- and S-endosymbionts of three Mycopsylla (Homotomidae) species to explore whether they have congruent phylogenies and within-species geographic structures. The P-endosymbiont Carsonella, a S-endosymbiont and Wolbachia all had 100% prevalence, while Arsenophonus was only found in one species at low prevalence. Congruent phylogenies of Mycopsylla and P-endosymbionts across populations and species support strict cospeciation. S-endosymbiont phylogenies were also congruent across host species but low genetic variation in the S-endosymbiont was not correlated with host phylogeography, possibly due to a shorter evolutionary association. Between species, Wolbachia and Mycopsylla phylogenies were incongruent, probably due to horizontal transmission events. Our study is the first to explore endosymbionts of Mycopsylla and further supports the codivergence of Psylloidea hosts and P-endosymbionts, with obligate host interactions for both P- and S-endosymbionts.}, }
@article {pmid27664781, year = {2016}, author = {Kupper, M and Stigloher, C and Feldhaar, H and Gross, R}, title = {Distribution of the obligate endosymbiont Blochmannia floridanus and expression analysis of putative immune genes in ovaries of the carpenter ant Camponotus floridanus.}, journal = {Arthropod structure &amp; development}, volume = {45}, number = {5}, pages = {475-487}, doi = {10.1016/j.asd.2016.09.004}, pmid = {27664781}, issn = {1873-5495}, mesh = {Animals ; Ants/genetics/*microbiology/ultrastructure ; Enterobacteriaceae/genetics/*physiology ; Female ; Gene Expression Regulation ; In Situ Hybridization, Fluorescence ; Microscopy, Electron, Transmission ; Oocytes/microbiology/ultrastructure ; Ovary/metabolism/*microbiology/ultrastructure ; }, abstract = {The bacterial endosymbiont Blochmannia floridanus of the carpenter ant Camponotus floridanus contributes to its hosts' ontogeny via nutritional upgrading during metamorphosis. This primary endosymbiosis is essential for both partners and vertical transmission of the endosymbionts is guaranteed by bacterial infestation of oocytes. Here we present a detailed analysis of the presence and localisation of B. floridanus in the ants' ovaries obtained by FISH and TEM analyses. The most apical part of the germarium harbouring germ-line stem cells (GSCs) is not infected by the bacteria. The bacteria are detectable for the first time in lower parts of the germarium when cystocytes undergo the 4th and 5th division and B. floridanus infects somatic cells lying under the basal lamina surrounding the ovarioles. With the beginning of cystocyte differentiation, the endosymbionts are exclusively transported from follicle cells into the growing oocytes. This infestation of the oocytes by bacteria very likely involves exocytosis-endocytosis processes between follicle cells and the oocytes. Nurse cells were never found to harbour the endosymbionts. Furthermore we present first gene expression data in C. floridanus ovaries. These data indicate a modulation of immune gene expression which may facilitate tolerance towards the endosymbionts and thus may contribute to their transovarial transmission.}, }
@article {pmid27763821, year = {2016}, author = {Khoo, JJ and Lim, FS and Chen, F and Phoon, WH and Khor, CS and Pike, BL and Chang, LY and AbuBakar, S}, title = {Coxiella Detection in Ticks from Wildlife and Livestock in Malaysia.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {16}, number = {12}, pages = {744-751}, pmid = {27763821}, issn = {1557-7759}, mesh = {Animals ; Animals, Wild/*parasitology ; Bacterial Proteins/genetics ; Coxiella/*isolation &amp; purification ; DNA, Bacterial/genetics ; Female ; Goat Diseases/epidemiology/parasitology ; Goats ; Livestock/*parasitology ; Malaysia/epidemiology ; Male ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Tick Infestations/epidemiology/*veterinary ; Ticks/*microbiology ; }, abstract = {Recent studies have shown that ticks harbor Coxiella-like bacteria, which are potentially tick-specific endosymbionts. We recently described the detection of Coxiella-like bacteria and possibly Coxiella burnetii in ticks found from rural areas in Malaysia. In the present study, we collected ticks, including Haemaphysalis bispinosa, Haemaphysalis hystricis, Dermacentor compactus, Dermacentor steini, and Amblyomma sp. from wildlife and domesticated goats from four different locations in Malaysia. Coxiella 16s rRNA genomic sequences were detected by PCR in 89% of ticks tested. Similarity analysis and phylogenetic analyses of the 16s rRNA and rpoB partial sequences were performed for 10 representative samples selected based on the tick species, sex, and location. The findings here suggested the presence of C. burnetii in two samples, each from D. steini and H. hystricis. The sequences of both samples clustered with published C. burnetii sequences. The remaining eight tick samples were shown to harbor 16s rRNA sequences of Coxiella-like bacteria, which clustered phylogenetically according to the respective tick host species. The findings presented here added to the growing evidence of the association between Coxiella-like bacteria and ticks across species and geographical boundaries. The importance of C. burnetii found in ticks in Malaysia warrants further investigation.}, }
@article {pmid27752109, year = {2016}, author = {Tamarozzi, F and Turner, JD and Pionnier, N and Midgley, A and Guimaraes, AF and Johnston, KL and Edwards, SW and Taylor, MJ}, title = {Wolbachia endosymbionts induce neutrophil extracellular trap formation in human onchocerciasis.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {35559}, pmid = {27752109}, issn = {2045-2322}, support = {MR/L018756/1/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Cell-Derived Microparticles/metabolism ; Doxycycline/pharmacology/therapeutic use ; Extracellular Traps/drug effects/*metabolism ; Female ; Fluorescent Antibody Technique ; Humans ; Lipopeptides/metabolism ; Mice ; Mice, Inbred C57BL ; Microspheres ; Neutrophil Infiltration/drug effects ; Neutrophils/drug effects/*metabolism ; Onchocerciasis/drug therapy/*microbiology/pathology ; *Symbiosis/drug effects ; Toll-Like Receptor 6/metabolism ; Wolbachia/drug effects/*physiology ; }, abstract = {The endosymbiotic bacteria, Wolbachia, induce neutrophilic responses to the human helminth pathogen Onchocerca volvulus. The formation of Neutrophil Extracellular Traps (NETs), has been implicated in anti-microbial defence, but has not been identified in human helminth infection. Here, we demonstrate NETs formation in human onchocerciasis. Extracellular NETs and neutrophils were visualised around O. volvulus in nodules excised from untreated patients but not in nodules from patients treated with the anti-Wolbachia drug, doxycycline. Whole Wolbachia or microspheres coated with a synthetic Wolbachia lipopeptide (WoLP) of the major nematode Wolbachia TLR2/6 ligand, peptidoglycan associated lipoprotein, induced NETosis in human neutrophils in vitro. TLR6 dependency of Wolbachia and WoLP NETosis was demonstrated using purified neutrophils from TLR6 deficient mice. Thus, we demonstrate for the first time that NETosis occurs during natural human helminth infection and demonstrate a mechanism of NETosis induction via Wolbachia endobacteria and direct ligation of Wolbachia lipoprotein by neutrophil TLR2/6.}, }
@article {pmid27734894, year = {2016}, author = {Brown, AM and Wasala, SK and Howe, DK and Peetz, AB and Zasada, IA and Denver, DR}, title = {Genomic evidence for plant-parasitic nematodes as the earliest Wolbachia hosts.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {34955}, pmid = {27734894}, issn = {2045-2322}, mesh = {Animals ; Biological Evolution ; DNA, Bacterial/genetics ; Female ; Gene Library ; *Genome, Bacterial ; Genomics ; Homeostasis ; In Situ Hybridization, Fluorescence ; Iron/metabolism ; Likelihood Functions ; Male ; Nematoda/*microbiology ; Phenotype ; Phylogeny ; Plants/*parasitology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia, one of the most widespread endosymbionts, is a target for biological control of mosquito-borne diseases (malaria and dengue virus), and antibiotic elimination of infectious filarial nematodes. We sequenced and analyzed the genome of a new Wolbachia strain (wPpe) in the plant-parasitic nematode Pratylenchus penetrans. Phylogenomic analyses placed wPpe as the earliest diverging Wolbachia, suggesting two evolutionary invasions into nematodes. The next branches comprised strains in sap-feeding insects, suggesting Wolbachia may have first evolved as a nutritional mutualist. Genome size, protein content, %GC, and repetitive DNA allied wPpe with mutualistic Wolbachia, whereas gene repertoire analyses placed it between parasite (A, B) and mutualist (C, D, F) groups. Conservation of iron metabolism genes across Wolbachia suggests iron homeostasis as a potential factor in its success. This study enhances our understanding of this globally pandemic endosymbiont, highlighting genetic patterns associated with host changes. Combined with future work on this strain, these genomic data could help provide potential new targets for plant-parasitic nematode control.}, }
@article {pmid27731377, year = {2016}, author = {Liu, JN and Yu, ZJ and Liu, LM and Li, NX and Wang, RR and Zhang, CM and Liu, JZ}, title = {Identification, Distribution and Population Dynamics of Francisella-like Endosymbiont in Haemaphysalis doenitzi (Acari: Ixodidae).}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {35178}, pmid = {27731377}, issn = {2045-2322}, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Francisella/*classification/genetics/physiology ; Genes, Bacterial ; Ixodidae/growth &amp; development/*microbiology/physiology ; Male ; Microscopy, Electron, Transmission ; Phylogeny ; Symbiosis ; }, abstract = {Francisella-like endosymbionts (FLEs) with significant homology to Francisella tularensis (γ-proteobacteria) have been characterized in several tick species, whereas knowledge on their distribution and population dynamics in ticks remains meager. Hence, in the current study, we identified a novel Francisella-like endosymbiont (FLEs-Hd) from the tick Haemaphysalis doenitzi and evaluated the putative functions of this symbiont. Results indicated that FLEs-Hd had 100% infection rate and a perfect vertical transmission in H. doenitzi, and that it is distributed in ovaries, malpighian tubules, salivary glands and midguts of the ticks, suggesting that FLEs-Hd presumably is a crucial symbiont of the host without specific tissue tropism. To further explore the function of the symbiont, the population dynamics of FLEs-Hd at each developmental stage of ticks and in tissues at different reproductive statuses were determined by real-time quantitative polymerase chain reaction (real-time qPCR). Results showed that the high density and regular population dynamics of FLEs-Hd appeared in female ovaries, suggesting that the symbiont may provide necessary nutrients or regulators to ensure normal ovary development of ticks.}, }
@article {pmid27731327, year = {2017}, author = {Kemp, DJ and Thomson, FE and Edwards, W and Iturbe-Ormaetxe, I}, title = {Incomplete offspring sex bias in Australian populations of the butterfly Eurema hecabe.}, journal = {Heredity}, volume = {118}, number = {3}, pages = {284-292}, pmid = {27731327}, issn = {1365-2540}, mesh = {Animals ; Australia ; Butterflies/*genetics/microbiology ; Female ; Male ; Pedigree ; *Sex Ratio ; Wolbachia ; }, abstract = {Theory predicts unified sex ratios for most organisms, yet biases may be engendered by selfish genetic elements such as endosymbionts that kill or feminize individuals with male genotypes. Although rare, feminization is established for Wolbachia-infected Eurema butterflies. This paradigm is presently confined to islands in the southern Japanese archipelago, where feminized phenotypes produce viable all-daughter broods. Here, we characterize sex bias for E. hecabe in continental Australia. Starting with 186 wild-caught females, we reared >6000 F1-F3 progeny in pedigree designs that incorporated selective antibiotic treatments. F1 generations expressed a consistent bias across 2 years and populations that was driven by an ~5% incidence of broods comprising ⩾80% daughters. Females from biased lineages continued to overproduce daughters over two generations of outcrossing to wild males. Treatment with antibiotics of differential strength influenced sex ratio only in biased lineages by inducing an equivalent incomplete degree of son overproduction. Brood sex ratios were nevertheless highly variable within lineages and across generations. Intriguingly, the cytogenetic signature of female karyotype was uniformly absent, even among phenotypic females in unbiased lineages. Molecular evidence supported the existence of a single Wolbachia strain at high prevalence, yet this was not clearly linked to brood sex bias. In sum, we establish an inherited, experimentally reversible tendency for incomplete offspring bias. Key features of our findings clearly depart from the Japanese feminization paradigm and highlight the potential for more subtle degrees of sex distortion in arthropods.}, }
@article {pmid27730310, year = {2017}, author = {Brentassi, ME and Franco, E and Balatti, P and Medina, R and Bernabei, F and Marino de Remes Lenicov, AM}, title = {Bacteriomes of the corn leafhopper, Dalbulus maidis (DeLong &amp; Wolcott, 1923) (Insecta, Hemiptera, Cicadellidae: Deltocephalinae) harbor Sulcia symbiont: molecular characterization, ultrastructure, and transovarial transmission.}, journal = {Protoplasma}, volume = {254}, number = {3}, pages = {1421-1429}, pmid = {27730310}, issn = {1615-6102}, mesh = {Animals ; *Bacteroidetes/classification/genetics/isolation &amp; purification ; Base Sequence ; DNA, Bacterial/genetics ; Female ; Hemiptera/*microbiology ; Microbiota/*genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {In this study, we surveyed the bacteriome-associated microbiota of the corn leafhopper Dalbulus maidis by means of histological, ultrastructural, and molecular analyses. Amplification and sequencing of 16S rDNA genes revealed that the endosymbiont "Candidatus Sulcia muelleri" (Phylum Bacteroidetes) resides in bacteriomes of D. maidis. Phylogenetic analysis showed that the sequence was closely allied to others found in representatives of the subfamily Deltocephalinae. We failed to amplify other sequences as "Candidatus Nasuia deltocephalinicola," a co-primary symbiont frequently associated to deltocephaline leafhoppers. In addition, a metagenetic analysis carried out in order to investigate the presence of other bacteriome-associated bacteria of D. maidis showed that the sequence of Sulcia accounted for 98.56 % of all the sequences. Histological and ultrastructural observations showed that microorganisms harbored in bacteriomes (central syncytium and cytoplasm of uninucleate bacteriocytes) look like others Sulcia described in hemipteran species and they were transovarially transmitted from mother to offspring which is typical of obligate endosymbionts. The only presence of Sulcia in the bacteriomes of D. maidis was discussed.}, }
@article {pmid27723934, year = {2017}, author = {Latorre, A and Manzano-Marín, A}, title = {Dissecting genome reduction and trait loss in insect endosymbionts.}, journal = {Annals of the New York Academy of Sciences}, volume = {1389}, number = {1}, pages = {52-75}, doi = {10.1111/nyas.13222}, pmid = {27723934}, issn = {1749-6632}, mesh = {Animals ; Bacteria/*genetics ; Contig Mapping ; Evolution, Molecular ; Genetic Complementation Test ; *Genome, Bacterial ; Genomics ; Insecta/*microbiology ; Phylogeny ; *Symbiosis ; }, abstract = {Symbiosis has played a major role in eukaryotic evolution beyond the origin of the eukaryotic cell. Thus, organisms across the tree of life are associated with diverse microbial partners, conferring to the host new adaptive traits that enable it to explore new niches. This is the case for insects thriving on unbalanced diets, which harbor mutualistic intracellular microorganisms, mostly bacteria that supply them with the required nutrients. As a consequence of the lifestyle change, from free-living to host-associated mutualist, a bacterium undergoes many structural and metabolic changes, of which genome shrinkage is the most dramatic. The trend toward genome size reduction in endosymbiotic bacteria is associated with large-scale gene loss, reflecting the lack of an effective selection mechanism to maintain genes that are rendered superfluous by the constant and rich environment provided by the host. This genome-reduction syndrome is so strong that it has generated the smallest bacterial genomes found to date, whose gene contents are so limited that their status as cellular entities is questionable. The recent availability of data on several endosymbiotic bacteria is enabling us to form a comprehensive picture of the genome-reduction process and the phenotypic consequences for the dwindling symbiont.}, }
@article {pmid27721807, year = {2016}, author = {Dittmer, J and van Opstal, EJ and Shropshire, JD and Bordenstein, SR and Hurst, GD and Brucker, RM}, title = {Disentangling a Holobiont - Recent Advances and Perspectives in Nasonia Wasps.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1478}, pmid = {27721807}, issn = {1664-302X}, abstract = {The parasitoid wasp genus Nasonia (Hymenoptera: Chalcidoidea) is a well-established model organism for insect development, evolutionary genetics, speciation, and symbiosis. The host-microbiota assemblage which constitutes the Nasonia holobiont (a host together with all of its associated microbes) consists of viruses, two heritable bacterial symbionts and a bacterial community dominated in abundance by a few taxa in the gut. In the wild, all four Nasonia species are systematically infected with the obligate intracellular bacterium Wolbachia and can additionally be co-infected with Arsenophonus nasoniae. These two reproductive parasites have different transmission modes and host manipulations (cytoplasmic incompatibility vs. male-killing, respectively). Pioneering studies on Wolbachia in Nasonia demonstrated that closely related Nasonia species harbor multiple and mutually incompatible Wolbachia strains, resulting in strong symbiont-mediated reproductive barriers that evolved early in the speciation process. Moreover, research on host-symbiont interactions and speciation has recently broadened from its historical focus on heritable symbionts to the entire microbial community. In this context, each Nasonia species hosts a distinguishable community of gut bacteria that experiences a temporal succession during host development and members of this bacterial community cause strong hybrid lethality during larval development. In this review, we present the Nasonia species complex as a model system to experimentally investigate questions regarding: (i) the impact of different microbes, including (but not limited to) heritable endosymbionts, on the extended phenotype of the holobiont, (ii) the establishment and regulation of a species-specific microbiota, (iii) the role of the microbiota in speciation, and (iv) the resilience and adaptability of the microbiota in wild populations subjected to different environmental pressures. We discuss the potential for easy microbiota manipulations in Nasonia as a promising experimental approach to address these fundamental aspects.}, }
@article {pmid27721806, year = {2016}, author = {Bouchon, D and Zimmer, M and Dittmer, J}, title = {The Terrestrial Isopod Microbiome: An All-in-One Toolbox for Animal-Microbe Interactions of Ecological Relevance.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1472}, pmid = {27721806}, issn = {1664-302X}, abstract = {Bacterial symbionts represent essential drivers of arthropod ecology and evolution, influencing host traits such as nutrition, reproduction, immunity, and speciation. However, the majority of work on arthropod microbiota has been conducted in insects and more studies in non-model species across different ecological niches will be needed to complete our understanding of host-microbiota interactions. In this review, we present terrestrial isopod crustaceans as an emerging model organism to investigate symbiotic associations with potential relevance to ecosystem functioning. Terrestrial isopods comprise a group of crustaceans that have evolved a terrestrial lifestyle and represent keystone species in terrestrial ecosystems, contributing to the decomposition of organic matter and regulating the microbial food web. Since their nutrition is based on plant detritus, it has long been suspected that bacterial symbionts located in the digestive tissues might play an important role in host nutrition via the provisioning of digestive enzymes, thereby enabling the utilization of recalcitrant food compounds (e.g., cellulose or lignins). If this were the case, then (i) the acquisition of these bacteria might have been an important evolutionary prerequisite for the colonization of land by isopods, and (ii) these bacterial symbionts would directly mediate the role of their hosts in ecosystem functioning. Several bacterial symbionts have indeed been discovered in the midgut caeca of terrestrial isopods and some of them might be specific to this group of animals (i.e., Candidatus Hepatoplasma crinochetorum, Candidatus Hepatincola porcellionum, and Rhabdochlamydia porcellionis), while others are well-known intracellular pathogens (Rickettsiella spp.) or reproductive parasites (Wolbachia sp.). Moreover, a recent investigation of the microbiota in Armadillidium vulgare has revealed that this species harbors a highly diverse bacterial community which varies between host populations, suggesting an important share of environmental microbes in the host-associated microbiota. In this review, we synthesize our current knowledge on the terrestrial isopod microbiome and identify future directions to (i) fully understand the functional roles of particular bacteria (both intracellular or intestinal symbionts and environmental gut passengers), and (ii) whether and how the host-associated microbiota could influence the performance of terrestrial isopods as keystone species in soil ecosystems.}, }
@article {pmid27720077, year = {2016}, author = {Tsuchida, T}, title = {Molecular basis and ecological relevance of aphid body colors.}, journal = {Current opinion in insect science}, volume = {17}, number = {}, pages = {74-80}, doi = {10.1016/j.cois.2016.07.005}, pmid = {27720077}, issn = {2214-5753}, mesh = {Animals ; Aphids/genetics/*physiology ; Ecosystem ; Pigmentation/genetics/*physiology ; }, abstract = {Aphids are small phloem sap-feeding insects, and show color polymorphism even within the same species. Crossing experiments have revealed the inheritance pattern of the body color. Coloration of aphids is determined by mainly three pigments, melanin, carotenoid, and aphin, and is influenced by both abiotic and biotic environmental factors. Aphid body colors also seem to correspond with specific biological functions under various environments. Partly due to the presence of natural enemies in the environment, a variety of physiological and behavioral responses have evolved in each color form. Thus, predation is one of the most significant external factors for maintaining body color polymorphisms. In addition, endosymbiont infections also influence aphid body color and prey-predator interactions. However, many unsolved questions remain regarding the molecular basis for and biological functions of aphid body colors. Further work, including the development of molecular techniques for comprehensive functional analysis, is needed in these areas.}, }
@article {pmid27715418, year = {2016}, author = {Tanaka, H and Yasuhara, M}, title = {A New Deep-Sea Hydrothermal Vent Species of Ostracoda (Crustacea) from the Western Pacific: Implications for Adaptation, Endemism, and Dispersal of Ostracodes in Chemosynthetic Systems.}, journal = {Zoological science}, volume = {33}, number = {5}, pages = {555-565}, doi = {10.2108/zs160079}, pmid = {27715418}, issn = {0289-0003}, mesh = {*Adaptation, Physiological ; Animal Distribution/*physiology ; Animals ; Crustacea/anatomy &amp; histology/*classification/genetics ; *Hydrothermal Vents ; Pacific Ocean ; Species Specificity ; }, abstract = {Deep-sea hydrothermal vent fields are among the most extreme habitats on Earth. Major research interests in these ecosystems have focused on the anomalous macrofauna, which are nourished by chemoautotrophic bacterial endosymbionts. In contrast, the meiofauna is largely overlooked in this chemosynthetic environment. The present study describes a new species, Thomontocypris shimanagai sp. nov. (Crustacea: Ostracoda), which was collected from the surface of colonies of neoverrucid barnacles and paralvinellid worms on the chimneys at the Myojin-sho submarine caldera. This is the first discovery of an ostracode from deep-sea hydrothermal vent environments in the western Pacific region. In addition to the species description, we discuss three aspects: 1) adaptation, 2) endemism, and 3) dispersal strategy of the hydrothermal vent ostracodes. Regarding these aspects, we conclude the following: 1) the new species may feed on sloughed-off tissues, mucus secretions, or fecal pellets of sessile organisms, rather than depend on chemoautotrophic bacteria as symbionts for energy; 2) as has been pointed out by other studies, Thomontocypris does not likely represent a vent-specific genus; however, this new species is considered to be endemic at the species level, as it has not been found outside of the type locality; and 3) this new species may have migrated from adjacent deep-sea chemosynthesis-based habitats, such as hydrothermal vents, with wood falls potentially having acted as stepping stones.}, }
@article {pmid27713733, year = {2016}, author = {Weiss, B and Kaltenpoth, M}, title = {Bacteriome-Localized Intracellular Symbionts in Pollen-Feeding Beetles of the Genus Dasytes (Coleoptera, Dasytidae).}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1486}, pmid = {27713733}, issn = {1664-302X}, abstract = {Several insect taxa are associated with intracellular symbionts that provision limiting nutrients to their hosts. Such tightly integrated symbioses are especially common in insects feeding on nutritionally challenging diets like phloem sap or vertebrate blood, but also occur in seed-eating and omnivorous taxa. Here, we characterize an intracellular symbiosis in pollen-feeding beetles of the genus Dasytes (Coleoptera, Dasytidae). High-throughput tag-encoded 16S amplicon pyrosequencing of adult D. plumbeus and D. virens revealed a single gamma-proteobacterial symbiont ('Candidatus Dasytiphilus stammeri') that amounts to 52.4-98.7% of the adult beetles' entire microbial community. Almost complete 16S rRNA sequences phylogenetically placed the symbiont into a clade comprising Buchnera and other insect endosymbionts, but sequence similarities to these closest relatives were surprisingly low (83.4-87.4%). Using histological examination, three-dimensional reconstructions, and fluorescence in situ hybridization, we localized the symbionts in three mulberry-shaped bacteriomes that are associated with the mid- to hind-gut transition in adult male and female beetles. Given the specialized pollen-feeding habits of the adults that contrasts with the larvae's carnivorous lifestyle, the symbionts may provision limiting essential amino acids or vitamins as in other intracellular symbioses, or they might produce digestive enzymes that break up the fastidious pollen walls and thereby contribute to the host's nutrition. In either case, the presence of gamma-proteobacterial symbionts in pollen-feeding beetles indicates that intracellular mutualists are more widely distributed across insects with diverse feeding habits than previously recognized.}, }
@article {pmid27713560, year = {2016}, author = {Kumar, N and Lin, M and Zhao, X and Ott, S and Santana-Cruz, I and Daugherty, S and Rikihisa, Y and Sadzewicz, L and Tallon, LJ and Fraser, CM and Dunning Hotopp, JC}, title = {Efficient Enrichment of Bacterial mRNA from Host-Bacteria Total RNA Samples.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {34850}, pmid = {27713560}, issn = {2045-2322}, support = {DP2 OD007372/OD/NIH HHS/United States ; HHSN272200900009C/AI/NIAID NIH HHS/United States ; R01 AI047885/AI/NIAID NIH HHS/United States ; U19 AI110820/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/microbiology ; Drosophila/microbiology ; Ehrlichia chaffeensis/genetics ; *Genetic Techniques ; High-Throughput Nucleotide Sequencing/methods ; Host-Pathogen Interactions/*genetics ; Microfluidic Analytical Techniques ; Poly A/chemistry ; RNA, Bacterial/chemistry/*isolation &amp; purification ; RNA, Messenger/chemistry/*isolation &amp; purification ; RNA, Ribosomal/chemistry ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Symbiosis ; Wolbachia/genetics/pathogenicity ; Wolves/microbiology ; }, abstract = {Despite numerous advances in genomics and bioinformatics, technological hurdles remain to examine host-microbe transcriptomics. Sometimes the transcriptome of either or both can be ascertained merely by generating more sequencing reads. However, many cases exist where bacterial mRNA needs to be enriched further to enable cost-effective sequencing of the pathogen or endosymbiont. While a suitable method is commercially available for mammalian samples of this type, development of such methods has languished for invertebrate samples. Furthermore, a common method across multiple taxa would facilitate comparisons between bacteria in invertebrate vectors and their vertebrate hosts. Here, a method is described to concurrently remove polyadenylated transcripts, prokaryotic rRNA, and eukaryotic rRNA, including those with low amounts of starting material (e.g. 100 ng). In a Wolbachia-Drosophila system, this bacterial mRNA enrichment yielded a 3-fold increase in Wolbachia mRNA abundance and a concomitant 3.3-fold increase in the percentage of transcripts detected. More specifically, 70% of the genome could be recovered by transcriptome sequencing compared to 21% in the total RNA. Sequencing of similar bacterial mRNA-enriched samples generated from Ehrlichia-infected canine cells covers 93% of the Ehrlichia genome, suggesting ubiquitous transcription across the entire Ehrlichia chaffeensis genome. This technique can potentially be used to enrich bacterial mRNA in many studies of host-microbe interactions.}, }
@article {pmid27693536, year = {2016}, author = {Kuesel, AC}, title = {Research for new drugs for elimination of onchocerciasis in Africa.}, journal = {International journal for parasitology. Drugs and drug resistance}, volume = {6}, number = {3}, pages = {272-286}, pmid = {27693536}, issn = {2211-3207}, support = {001/WHO_/World Health Organization/International ; }, mesh = {Africa/epidemiology ; Animals ; *Disease Eradication ; Drug Approval ; Drug Discovery/*trends ; Drug Therapy/*methods ; Filaricides/*isolation &amp; purification/*therapeutic use ; Onchocerciasis/*epidemiology/*prevention &amp; control ; }, abstract = {Onchocerciasis is a parasitic, vector borne disease caused by the filarial nematode Onchocerca volvulus. More than 99% of the population at risk of infection live in Africa. Onchocerciasis control was initiated in West Africa in 1974 with vector control, later complemented by ivermectin mass drug administration and in the other African endemic countries in 1995 with annual community directed treatment with ivermectin (CDTI.) This has significantly reduced infection prevalence. Together with proof-of-concept for onchocerciasis elimination with annual CDTI from foci in Senegal and Mali, this has resulted in targeting onchocerciasis elimination in selected African countries by 2020 and in 80% of African countries by 2025. The challenges for meeting these targets include the number of endemic countries where conflict has delayed or interrupted control programmes, cross-border foci, potential emergence of parasite strains with low susceptibility to ivermectin and co-endemicity of loiasis, another parasitic vector borne disease, which slows down or prohibits CDTI implementation. Some of these challenges could be addressed with new drugs or drug combinations with a higher effect on Onchocerca volvulus than ivermectin. This paper reviews the path from discovery of new compounds to their qualification for large scale use and the support regulatory authorities provide for development of drugs for neglected tropical diseases. The status of research for new drugs or treatment regimens for onchocerciasis along the path to regulatory approval and qualification for large scale use is reviewed. This research includes new regimens and combinations of ivermectin and albendazole, antibiotics targeting the O. volvulus endosymbiont Wolbachia, flubendazole, moxidectin and emodepside and discovery of new compounds.}, }
@article {pmid27692043, year = {2016}, author = {Schnettler, E and Sreenu, VB and Mottram, T and McFarlane, M}, title = {Wolbachia restricts insect-specific flavivirus infection in Aedes aegypti cells.}, journal = {The Journal of general virology}, volume = {97}, number = {11}, pages = {3024-3029}, pmid = {27692043}, issn = {1465-2099}, support = {MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/1/MRC_/Medical Research Council/United Kingdom ; G0801822/MRC_/Medical Research Council/United Kingdom ; MC_UP_A550_1031/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/12/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Aedes/*microbiology/*virology ; Animals ; Drosophila/microbiology ; Flavivirus/*physiology ; Insect Vectors/microbiology/virology ; Species Specificity ; Wolbachia/*physiology ; }, abstract = {Mosquito-borne viruses are known to cause disease in humans and livestock and are often difficult to control due to the lack of specific antivirals and vaccines. The Wolbachia endosymbiont has been widely studied for its ability to restrict positive-strand RNA virus infection in mosquitoes, although little is known about the precise antiviral mechanism. In recent years, a variety of insect-specific viruses have been discovered in mosquitoes and an interaction with mosquito-borne viruses has been reported for some of them; however, nothing is known about the effect of Wolbachia on insect-specific virus infection in mosquitoes. Here, we show that transinfection of the Drosophila-derived wMelPop Wolbachia strain into Aedes aegypti-derived cells resulted in inhibition and even clearance of the persistent cell-fusing agent flavivirus infection in these cells. This broadens the antiviral activity of Wolbachia from acute infections to persistent infections and from arboviruses to mosquito-specific viruses. In contrast, no effect on the Phasi Charoen-like bunyavirus persistent infection in these cells was observed, suggesting a difference in Wolbachia inhibition between positive- and negative-strand RNA viruses.}, }
@article {pmid27690269, year = {2016}, author = {McIlroy, SE and Gillette, P and Cunning, R and Klueter, A and Capo, T and Baker, AC and Coffroth, MA}, title = {The effects of Symbiodinium (Pyrrhophyta) identity on growth, survivorship, and thermal tolerance of newly settled coral recruits.}, journal = {Journal of phycology}, volume = {52}, number = {6}, pages = {1114-1124}, doi = {10.1111/jpy.12471}, pmid = {27690269}, issn = {1529-8817}, mesh = {Animals ; Anthozoa/growth &amp; development/*physiology ; Dinoflagellida/*physiology ; Florida ; Species Specificity ; *Symbiosis ; *Thermotolerance ; }, abstract = {For many coral species, the obligate association with phylogenetically diverse algal endosymbiont species is dynamic in time and space. Here, we used controlled laboratory inoculations of newly settled, aposymbiotic corals (Orbicella faveolata) with two cultured species of algal symbiont (Symbiodinium microadriaticum and S. minutum) to examine the role of symbiont identity on growth, survivorship, and thermal tolerance of the coral holobiont. We evaluated these data in the context of Symbiodinium photophysiology for 9 months post-settlement and also during a 5-d period of elevated temperatures Our data show that recruits that were inoculated with S. minutum grew significantly slower than those inoculated with S. microadriaticum (occasionally co-occurring with S. minutum), but that there was no difference in survivorship of O. faveolata polyps infected with Symbiodinium. However, photophysiological metrics (∆Fv/F'm, the efficiency with which available light is used to drive photosynthesis and α, the maximum light utilization coefficient) were higher in those slower growing recruits containing S. minutum. These findings suggest that light use (i.e., photophysiology) and carbon acquisition by the coral host (i.e., host growth) are decoupled, but did not distinguish the source of this difference. Neither Symbiodinium treatment demonstrated a significant negative effect of a 5-d exposure to temperatures as high as 32°C under low light conditions similar to those measured at settlement habitats.}, }
@article {pmid27686386, year = {2017}, author = {Papa, A and Tsioka, K and Kontana, A and Papadopoulos, C and Giadinis, N}, title = {Bacterial pathogens and endosymbionts in ticks.}, journal = {Ticks and tick-borne diseases}, volume = {8}, number = {1}, pages = {31-35}, doi = {10.1016/j.ttbdis.2016.09.011}, pmid = {27686386}, issn = {1877-9603}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Female ; Goat Diseases/epidemiology/parasitology ; Goats ; Greece/epidemiology ; Ixodidae/*microbiology ; Male ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Ticks collected from goats in northern Greece were tested for the presence of tick-borne bacteria. Among adult ticks, 37 (57.8%) were Rhipicephalus bursa, 11 (17.2%) Dermacentor marginatus, 10 (15.6%) Ixodes ricinus, 3 (4.7%) Rhipicephalus sanguineus sensu lato and 2 (3.1%) Haemaphysalis parva; one (1.6%) Rhipicephalus spp. tick was nymph. Rickettsia monacensis, Rickettsia massilae, Anaplasma phagocytophilum and Anaplasma platys were detected in I. ricinus and Rh. bursa ticks. A variety of Coxiella-like endosymbionts were detected in all tick genera tested, forming distinct clades from Coxiella burnetii in the phylogenetic tree based on the 16S rRNA gene. An additional endosymbiont, Candidatus Midichloria mitochondrii, was detected in most of the I. ricinus ticks. Surveillance for human pathogens in ticks provides knowledge helpful for the public health, while further studies are needed to determine the role of endosymbionts in tick physiology, vector competence and probably in public health.}, }
@article {pmid27684942, year = {2016}, author = {Faria, VG and Martins, NE and Magalhães, S and Paulo, TF and Nolte, V and Schlötterer, C and Sucena, &#xc9; and Teixeira, L}, title = {Drosophila Adaptation to Viral Infection through Defensive Symbiont Evolution.}, journal = {PLoS genetics}, volume = {12}, number = {9}, pages = {e1006297}, pmid = {27684942}, issn = {1553-7404}, support = {P 27630/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Microbial symbionts can modulate host interactions with biotic and abiotic factors. Such interactions may affect the evolutionary trajectories of both host and symbiont. Wolbachia protects Drosophila melanogaster against several viral infections and the strength of the protection varies between variants of this endosymbiont. Since Wolbachia is maternally transmitted, its fitness depends on the fitness of its host. Therefore, Wolbachia populations may be under selection when Drosophila is subjected to viral infection. Here we show that in D. melanogaster populations selected for increased survival upon infection with Drosophila C virus there is a strong selection coefficient for specific Wolbachia variants, leading to their fixation. Flies carrying these selected Wolbachia variants have higher survival and fertility upon viral infection when compared to flies with the other variants. These findings demonstrate how the interaction of a host with pathogens shapes the genetic composition of symbiont populations. Furthermore, host adaptation can result from the evolution of its symbionts, with host and symbiont functioning as a single evolutionary unit.}, }
@article {pmid27681542, year = {2016}, author = {Mohanty, I and Rath, A and Mahapatra, N and Hazra, RK}, title = {Wolbachia: A biological control strategy against arboviral diseases.}, journal = {Journal of vector borne diseases}, volume = {53}, number = {3}, pages = {199-207}, pmid = {27681542}, issn = {0972-9062}, mesh = {Animals ; Antibiosis ; Arbovirus Infections/epidemiology/*prevention &amp; control ; Arboviruses/*growth &amp; development ; Culicidae/*microbiology ; Disease Transmission, Infectious/*prevention &amp; control ; Humans ; Mosquito Control/*methods ; Wolbachia/*growth &amp; development ; }, abstract = {Vector-borne diseases particularly those transmitted by mosquitoes like Dengue are among the leading causes of mortality and morbidity in human population. There are no effective vaccines or treatment against dengue fever till date and the control methods are limited. So, new approaches are urgently in need to reverse these trends. Vector control is currently the primary intervention tool. Strategies that reduce or block pathogen transmission by mosquitoes have been proposed as a means of augmenting current control measures to reduce the growing burden of vector-borne diseases. Wolbachia an endosymbiont of arthropod vectors is being explored as a novel ecofriendly control strategy. Studies in Drosophila have shown that Wolbachia can confer resistance to diverse RNA viruses and protect flies from virus-induced mortality. This review was focused on biology of the Wolbachia and its implication as a control measure for arboviral diseases mainly Dengue and Chikungunya.}, }
@article {pmid27664751, year = {2016}, author = {Liu, N and Ning, GA and Liu, XH and Feng, XX and Lu, JP and Mao, LJ and Su, ZZ and Wang, Y and Zhang, CL and Lin, FC}, title = {An autophagy gene, HoATG5, is involved in sporulation, cell wall integrity and infection of wounded barley leaves.}, journal = {Microbiological research}, volume = {192}, number = {}, pages = {326-335}, doi = {10.1016/j.micres.2016.08.008}, pmid = {27664751}, issn = {1618-0623}, mesh = {Ascomycota/*physiology ; Autophagy/*genetics ; Autophagy-Related Protein 5/*genetics ; Base Sequence ; Cell Wall/*genetics/*metabolism ; Cloning, Molecular ; Fungal Proteins/genetics/metabolism ; Hordeum/*microbiology ; Mutation ; Phenotype ; Plant Diseases/microbiology ; Plant Leaves/*microbiology ; Protein Binding ; Sequence Analysis, DNA ; Sequence Deletion ; *Spores, Fungal ; }, abstract = {The endophytic fungus Harpophora oryzae is a beneficial endosymbiont isolated from wild rice. H. oryzae can not only promote rice growth and biomass accumulation but also protect rice roots from invasion by its close relative Magnaporthe oryzae. Autophagy is a highly evolutionary conserved process from lower to higher eukaryotic organisms, and is involved in the maintenance of normal cell differentiation and development. In this study, we isolated a gene (HoATG5) which encodes an essential protein required for autophagy from the beneficial endophyte fungus H. oryzae. Using targeted gene replacement, a ΔHoATG5 mutant was generated and used to investigate the biological functions of autophagy in H. oryzae. We found that the autophagic process was blocked in the HoATG5 deletion mutant. The mutant showed increased vegetative growth and sporulation, and was sensitive to nutrient starvation. The ΔHoATG5 mutant lost its ability to penetrate and infect the wounded barley leaves. These results provide new knowledge to elaborate the molecular machinery of autophagy in endophytic fungi.}, }
@article {pmid27648768, year = {2016}, author = {Mascarenhas, RO and Prezotto, LF and Perondini, AL and Marino, CL and Selivon, D}, title = {Wolbachia in guilds of Anastrepha fruit flies (Tephritidae) and parasitoid wasps (Braconidae).}, journal = {Genetics and molecular biology}, volume = {39}, number = {4}, pages = {600-610}, pmid = {27648768}, issn = {1415-4757}, abstract = {The endosymbiont Wolbachia is efficiently transmitted from females to their progenies, but horizontal transmission between different taxa is also known to occur. Aiming to determine if horizontal transmission might have occurred between Anastrepha fruit flies and associated braconid wasps, infection by Wolbachia was screened by amplification of a fragment of the wsp gene. Eight species of the genus Anastrepha were analyzed, from which six species of associated parasitoid wasps were recovered. The endosymbiont was found in seven Anastrepha species and in five species of braconids. The WSP Typing methodology detected eight wsp alleles belonging to Wolbachia supergroup A. Three were already known and five were new ones, among which four were found to be putative recombinant haplotypes. Two samples of Anastrepha obliqua and one sample of Doryctobracon brasiliensis showed multiple infection. Single infection by Wolbachia was found in the majority of samples. The distribution of Wolbachia harboring distinct alleles differed significantly between fruit flies and wasps. However, in nine samples of fruit flies and associated wasps, Wolbachia harbored the same wsp allele. These congruences suggest that horizontal transfer of Wolbachia might have occurred in the communities of fruit flies and their braconid parasitoids.}, }
@article {pmid27645766, year = {2016}, author = {Gerhart, JG and Moses, AS and Raghavan, R}, title = {A Francisella-like endosymbiont in the Gulf Coast tick evolved from a mammalian pathogen.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {33670}, pmid = {27645766}, issn = {2045-2322}, mesh = {Animals ; *Biological Evolution ; Evolution, Molecular ; Francisella/classification/*physiology ; Genes, Bacterial ; Genome, Bacterial ; Genomics/methods ; *Host-Pathogen Interactions ; Humans ; Mammals ; Metabolic Networks and Pathways ; Phylogeny ; *Symbiosis ; Ticks/*microbiology ; Virulence/genetics ; }, abstract = {Ticks (order Ixodida) vector pathogenic bacteria that cause diseases in humans and other mammals. They also contain bacteria that are closely related to pathogens but function as endosymbionts that provide nutrients that are missing from mammalian blood-their sole food source. For instance, mammalian pathogens such as Coxiella burnetii and Francisella tularensis, as well as Coxiella-like and Francisella-like endosymbionts (CLEs and FLEs, respectively) occur in ticks worldwide. However, it is not clear whether the pathogens evolved from symbionts or symbionts from pathogens. Recent studies have indicated that C. burnetii likely originated from a tick-associated ancestor, but the origins of FLEs are not clear. In this study, we sequenced the genome of an FLE, termed FLE-Am, present in the Gulf Coast tick, Amblyomma maculatum. We show that FLE-Am likely evolved from a pathogenic strain of Francisella, indicating that tick endosymbionts can evolve from mammalian pathogens. Although the genome of FLE-Am is almost the same size as the genomes of pathogenic Francisella strains, about one-third of its protein-coding genes contain inactivating mutations. The relatively low coding capacity and extensive metabolic capabilities indicate that FLE-Am transitioned recently to its current endosymbiotic lifestyle and likely replaced an ancient endosymbiont with degraded functionality.}, }
@article {pmid27635050, year = {2016}, author = {Izawa, K and Kuwahara, H and Kihara, K and Yuki, M and Lo, N and Itoh, T and Ohkuma, M and Hongoh, Y}, title = {Comparison of Intracellular "Ca. Endomicrobium Trichonymphae" Genomovars Illuminates the Requirement and Decay of Defense Systems against Foreign DNA.}, journal = {Genome biology and evolution}, volume = {8}, number = {10}, pages = {3099-3107}, pmid = {27635050}, issn = {1759-6653}, mesh = {Animals ; Bacteria/*genetics/pathogenicity ; *CRISPR-Cas Systems ; *DNA Restriction-Modification Enzymes ; *Genome, Bacterial ; Hypermastigia/*microbiology/pathogenicity ; Isoptera/parasitology ; Open Reading Frames ; Pseudogenes ; Selection, Genetic ; Symbiosis/*genetics ; Virulence/genetics ; }, abstract = {"Candidatus Endomicrobium trichonymphae" (Bacteria; Elusimicrobia) is an obligate intracellular symbiont of the cellulolytic protist genus Trichonympha in the termite gut. A previous genome analysis of "Ca Endomicrobium trichonymphae" phylotype Rs-D17 (genomovar Ri2008), obtained from a Trichonympha agilis cell in the gut of the termite Reticulitermes speratus, revealed that its genome is small (1.1 Mb) and contains many pseudogenes; it is in the course of reductive genome evolution. Here we report the complete genome sequence of another Rs-D17 genomovar, Ti2015, obtained from a different T. agilis cell present in an R. speratus gut. These two genomovars share most intact protein-coding genes and pseudogenes, showing 98.6% chromosome sequence similarity. However, characteristic differences were found in their defense systems, which comprised restriction-modification and CRISPR/Cas systems. The repertoire of intact restriction-modification systems differed between the genomovars, and two of the three CRISPR/Cas loci in genomovar Ri2008 are pseudogenized or missing in genomovar Ti2015. These results suggest relaxed selection pressure for maintaining these defense systems. Nevertheless, the remaining CRISPR/Cas system in each genomovar appears to be active; none of the "spacer" sequences (112 in Ri2008 and 128 in Ti2015) were shared whereas the "repeat" sequences were identical. Furthermore, we obtained draft genomes of three additional endosymbiotic Endomicrobium phylotypes from different host protist species, and discovered multiple, intact CRISPR/Cas systems in each genome. Collectively, unlike bacteriome endosymbionts in insects, the Endomicrobium endosymbionts of termite-gut protists appear to require defense against foreign DNA, although the required level of defense has likely been reduced during their intracellular lives.}, }
@article {pmid27631277, year = {2016}, author = {Shibata, A and Takahashi, F and Kasahara, M and Imamura, N}, title = {Induction of Maltose Release by Light in the Endosymbiont Chlorella variabilis of Paramecium bursaria.}, journal = {Protist}, volume = {167}, number = {5}, pages = {468-478}, doi = {10.1016/j.protis.2016.08.007}, pmid = {27631277}, issn = {1618-0941}, mesh = {Carbon/metabolism ; Chlorella/*physiology/radiation effects ; Japan ; *Light ; Maltose/*metabolism ; Paramecium/*physiology ; Photosynthesis ; *Symbiosis ; }, abstract = {The endosymbiotic green algae of Paramecium bursaria are known to release a photosynthate to the host cells. The endosymbiont Chlorella variabilis F36-ZK isolated in Japan releases maltose under acidic conditions, and such release requires both light and low pH. However, whether photosynthate release is due to light sensing by photoreceptors or is merely a consequence of active photosynthesis is unclear. Herein, we studied the effect of light on maltose release from C. variabilis F36-ZK; we measured maltose release using a combination of 1-phenyl-3-methyl-5-pyrazolone derivative and [14]C-tracer methods. Blue (450nm) or red (around 600nm) light was most effective to stimulate maltose release. This suggests that the photosynthetic pathway probably participates in maltose release, because the effective wavelength corresponds to the absorption spectrum of chlorophyll. Furthermore, maltose release was slightly affected by addition of a photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but was abolished by another inhibitor of photosynthesis, 2,5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, suggesting that electron flow through photosystem I may be more involved in maltose release. Interestingly, starving F36-ZK cells cultured under prolonged dark conditions did not release maltose but retained their photosynthetic capacity. Our results thus show that maltose release is regulated by light and cellular conditions in endosymbiotic Chlorella.}, }
@article {pmid27622976, year = {2016}, author = {Michelet, L and Joncour, G and Devillers, E and Torina, A and Vayssier-Taussat, M and Bonnet, SI and Moutailler, S}, title = {Tick species, tick-borne pathogens and symbionts in an insular environment off the coast of Western France.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {6}, pages = {1109-1115}, doi = {10.1016/j.ttbdis.2016.08.014}, pmid = {27622976}, issn = {1877-9603}, mesh = {Animal Distribution ; Animals ; Bacteria/*isolation &amp; purification ; DNA, Bacterial/genetics ; Female ; France/epidemiology ; Islands/*epidemiology ; Ixodidae/microbiology ; Male ; Tick-Borne Diseases/epidemiology/*microbiology/*parasitology ; Ticks/*classification ; }, abstract = {Insular environments provide ideal natural conditions to study disease ecology, especially emerging diseases, due to clear differentiation between local and long-distance transmission. Such environments are of particular interest regarding tick-borne pathogens (TBP), since animal exchange with the mainland (along with any ticks they carry) is limited, and because such locations could lie on migratory routes for birds carrying ticks. Therefore both tick species and TBP may display different prevalence than those observed on the continent. As such, an epidemiological survey was performed on Belle-Ile-en-Mer, an island off the coast of Western France, in order to estimate the prevalence of tick species and the microorganisms they carried. Three tick species, Dermacentor marginatus, D. reticulatus, and Haemaphysalis punctata were collected at five different sites in 2010 and 2011. All ticks were tested for pathogen's and symbiont's DNA by (i) PCR for Anaplasma spp., Borrelia spp., Rickettsia spp.; (ii) real-time PCR for Francisella tularensis, Francisella-like endosymbionts (FLE) and Coxiella spp. and (iii) PCR-RLB for Babesia-Theileria spp. Pathogen DNA detected in D. marginatus including Borrelia spp. (18%), Rickettsia spp. (13%) which was identified as R. slovaca, Babesia spp. (8%), and Theileria spp. (1%). Pathogens detected in D. reticulatus including Rickettsia spp. (31%) identified as R. raoulti, Francisella-like endosymbiont (86%), and Babesia spp (21%). Pathogens detected in H. punctata including Rickettsia spp. (1%) identified as R. aeschlimannii, FLE (0.4%), Babesia spp. (18%), and Theileria spp. (7%). Anaplasma spp., F. tularensis, or Coxiella spp. were not detected in any of the collected ticks. This study represents the first epidemiological survey of the insular Belle-Ile-en-Mer environment. It demonstrated the presence of expected pathogens, consistent with reports from island veterinarians or physicians, as well as unexpected pathogens, raising questions about their potential introduction through infected animals and/or their dispersion by migratory birds.}, }
@article {pmid27620972, year = {2017}, author = {Alboresi, A and Le Quiniou, C and Yadav, SK and Scholz, M and Meneghesso, A and Gerotto, C and Simionato, D and Hippler, M and Boekema, EJ and Croce, R and Morosinotto, T}, title = {Conservation of core complex subunits shaped the structure and function of photosystem I in the secondary endosymbiont alga Nannochloropsis gaditana.}, journal = {The New phytologist}, volume = {213}, number = {2}, pages = {714-726}, pmid = {27620972}, issn = {1469-8137}, support = {281341/ERC_/European Research Council/International ; 309485/ERC_/European Research Council/International ; }, mesh = {Amino Acid Sequence ; *Conserved Sequence ; Light-Harvesting Protein Complexes/chemistry/metabolism/ultrastructure ; Models, Biological ; Photosystem I Protein Complex/*chemistry/*metabolism/ultrastructure ; Pigments, Biological/metabolism ; Protein Subunits/chemistry/*metabolism ; Spectrometry, Fluorescence ; Stramenopiles/*metabolism ; *Symbiosis ; Thylakoids/metabolism ; }, abstract = {Photosystem I (PSI) is a pigment protein complex catalyzing the light-driven electron transport from plastocyanin to ferredoxin in oxygenic photosynthetic organisms. Several PSI subunits are highly conserved in cyanobacteria, algae and plants, whereas others are distributed differentially in the various organisms. Here we characterized the structural and functional properties of PSI purified from the heterokont alga Nannochloropsis gaditana, showing that it is organized as a supercomplex including a core complex and an outer antenna, as in plants and other eukaryotic algae. Differently from all known organisms, the N. gaditana PSI supercomplex contains five peripheral antenna proteins, identified by proteome analysis as type-R light-harvesting complexes (LHCr4-8). Two antenna subunits are bound in a conserved position, as in PSI in plants, whereas three additional antennae are associated with the core on the other side. This peculiar antenna association correlates with the presence of PsaF/J and the absence of PsaH, G and K in the N. gaditana genome and proteome. Excitation energy transfer in the supercomplex is highly efficient, leading to a very high trapping efficiency as observed in all other PSI eukaryotes, showing that although the supramolecular organization of PSI changed during evolution, fundamental functional properties such as trapping efficiency were maintained.}, }
@article {pmid27619694, year = {2016}, author = {Speijer, D}, title = {What can we infer about the origin of sex in early eukaryotes?.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {371}, number = {1706}, pages = {}, pmid = {27619694}, issn = {1471-2970}, mesh = {*Biological Evolution ; Eukaryota/*physiology ; *Sex ; }, abstract = {Current analysis shows that the last eukaryotic common ancestor (LECA) was capable of full meiotic sex. The original eukaryotic life cycle can probably be described as clonal, interrupted by episodic sex triggered by external or internal stressors. The cycle could have started in a highly flexible form, with the interruption of either diploid or haploid clonal growth determined by stress signals only. Eukaryotic sex most likely evolved in response to a high mutation rate, arising from the uptake of the endosymbiont, as this (proto) mitochondrion generated internal reactive oxygen species. This is consistent with the likely development of full meiotic sex from a diverse set of existing archaeal (the host of the endosymbiont) repair and signalling mechanisms. Meiotic sex could thus have been one of the fruits of symbiogenesis at the basis of eukaryotic origins: a product of the merger by which eukaryotic cells arose. Symbiogenesis also explains the large-scale migration of organellar DNA to the nucleus. I also discuss aspects of uniparental mitochondrial inheritance and mitonuclear interactions in the light of the previous analysis.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.}, }
@article {pmid27618991, year = {2016}, author = {Vivero, RJ and Jaramillo, NG and Cadavid-Restrepo, G and Soto, SI and Herrera, CX}, title = {Structural differences in gut bacteria communities in developmental stages of natural populations of Lutzomyia evansi from Colombia's Caribbean coast.}, journal = {Parasites &amp; vectors}, volume = {9}, number = {1}, pages = {496}, pmid = {27618991}, issn = {1756-3305}, mesh = {Animal Distribution ; Animals ; Bacteria/*classification/*isolation &amp; purification ; Colombia ; Female ; Gastrointestinal Tract/*microbiology ; Life Cycle Stages ; Male ; Psychodidae/*microbiology ; }, abstract = {BACKGROUND: Lutzomyia evansi, a phlebotomine insect endemic to Colombia's Caribbean coast, is considered to be the main vector of visceral and cutaneous leishmaniasis in the region. Although insects of this species can harbor pathogenic and non-pathogenic microorganisms in their intestinal microbiota, there is little information available about the diversity of gut bacteria present in Lutzomyia evansi. In this study, conventional microbiological methods and molecular tools were used to assess the composition of bacterial communities associated with Lutzomyia evansi guts in immature and adult stages of natural populations from the department of Sucre (Caribbean coast of Colombia).<br><br>METHODS: Sand flies were collected from two locations (peri-urban and jungle biotype) in the Department of Sucre (Caribbean coast of Colombia). A total of 752 Lutzomyia evansi intestines were dissected. In this study, 125 bacterial strains were isolated from different culture media (LB Agar, MacConkey Agar). Different methods were used for bacterial identification, including ribosomal intergenic spacer analysis (RISA) and analysis of the 16S rRNA and gyrB gene sequences. The genetic profiles of the bacterial populations were generated and temporal temperature gradient gel electrophoresis (TTGE) was used to compare them with total gut DNA. We also used PCR and DNA sequence analysis to determine the presence of Wolbachia endosymbiont bacteria and Leishmania parasites.<br><br>RESULTS: The culture-dependent technique showed that the dominant intestinal bacteria isolated belong to Acinetobacter, Enterobacter, Pseudomonas, Ochrobactrum, Shinella and Paenibacillus in the larval stage; Lysobacter, Microbacterium, Streptomyces, Bacillus and Rummeliibacillus in the pupal stage; and Staphylococcus, Streptomyces, Brevibacterium, Acinetobacter, Enterobacter and Pantoea in the adult stage. Statistical analysis revealed significant differences between the fingerprint patterns of the PCR-TTGE bands in bacterial communities from immature and adult stages. Additionally, differences were found in bacterial community structure in fed females, unfed females, males and larvae. The intestinal bacteria detected by PCR-TTGE were Enterobacter cloacae and Bacillus thuringiensis, which were present in different life stages of Lu. evansi, and Burkholderia cenocepacia and Bacillus gibsonii, which were detected only in the larval stage. Wolbachia and Leishmania were not detected in gut samples of Lutzomyia evansi.<br><br>CONCLUSIONS: The analyses conducted using microbiological and molecular approaches indicated significant variations in the bacterial communities associated with the gut of Lu. evansi, depending on the developmental stage and food source. We propose that these elements affect microbial diversity in L. evansi guts and may in turn influence pathogen transmission to humans bitten by this insect.}, }
@article {pmid27608806, year = {2016}, author = {Pancsa, R and Tompa, P}, title = {Essential functions linked with structural disorder in organisms of minimal genome.}, journal = {Biology direct}, volume = {11}, number = {1}, pages = {45}, pmid = {27608806}, issn = {1745-6150}, mesh = {Amino Acid Sequence ; Bacteria/*genetics ; Bacterial Proteins/*genetics ; *Genome, Bacterial ; *Proteome ; }, abstract = {UNLABELLED: Intrinsically disordered regions (IDRs) of proteins fulfill important regulatory roles in most organisms. However, the proteins of certain endosymbiont and intracellular pathogenic bacteria with extremely reduced genomes contain disproportionately small amounts of IDRs, consisting almost entirely of folded domains. As their genomes co-evolving with their hosts have been reduced in unrelated lineages, the proteomes of these bacteria represent independently evolved minimal protein sets. We systematically analyzed structural disorder in a representative set of such minimal organisms to see which types of functionally relevant longer IDRs are invariably retained in them. We found that a few characteristic functions are consistently linked with conformational disorder: ribosomal proteins, key components of the protein production machinery, a central coordinator of DNA metabolism and certain housekeeping chaperones seem to strictly rely on structural disorder even in genome-reduced organisms. We propose that these functions correspond to the most essential and probably also the most ancient ones fulfilled by structural disorder in cellular organisms.<br><br>REVIEWERS: This article was reviewed by Michael Gromiha, Zoltan Gaspari and Sandor Pongor.}, }
@article {pmid27599759, year = {2016}, author = {Manzano-Marín, A and Latorre, A}, title = {Snapshots of a shrinking partner: Genome reduction in Serratia symbiotica.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {32590}, pmid = {27599759}, issn = {2045-2322}, mesh = {Amino Acids/biosynthesis ; Biosynthetic Pathways/genetics ; Cluster Analysis ; Gene Expression Regulation, Bacterial ; Gene Rearrangement ; Genes, Bacterial ; *Genome, Bacterial ; RNA Stability/genetics ; RNA, Bacterial/genetics ; RNA, Transfer/genetics ; Serratia/*genetics ; }, abstract = {Genome reduction is pervasive among maternally-inherited endosymbiotic organisms, from bacteriocyte- to gut-associated ones. This genome erosion is a step-wise process in which once free-living organisms evolve to become obligate associates, thereby losing non-essential or redundant genes/functions. Serratia symbiotica (Gammaproteobacteria), a secondary endosymbiont present in many aphids (Hemiptera: Aphididae), displays various characteristics that make it a good model organism for studying genome reduction. While some strains are of facultative nature, others have established co-obligate associations with their respective aphid host and its primary endosymbiont (Buchnera). Furthermore, the different strains hold genomes of contrasting sizes and features, and have strikingly disparate cell shapes, sizes, and tissue tropism. Finally, genomes from closely related free-living Serratia marcescens are also available. In this study, we describe in detail the genome reduction process (from free-living to reduced obligate endosymbiont) undergone by S. symbiotica, and relate it to the stages of integration to the symbiotic system the different strains find themselves in. We establish that the genome reduction patterns observed in S. symbiotica follow those from other dwindling genomes, thus proving to be a good model for the study of the genome reduction process within a single bacterial taxon evolving in a similar biological niche (aphid-Buchnera).}, }
@article {pmid27595990, year = {2016}, author = {Machado-Ferreira, E and Vizzoni, VF and Balsemão-Pires, E and Moerbeck, L and Gazeta, GS and Piesman, J and Voloch, CM and Soares, CA}, title = {Coxiella symbionts are widespread into hard ticks.}, journal = {Parasitology research}, volume = {115}, number = {12}, pages = {4691-4699}, pmid = {27595990}, issn = {1432-1955}, mesh = {Animals ; Brazil ; China ; Coxiella/classification/*isolation &amp; purification ; DNA, Ribosomal/genetics ; Ixodidae/*microbiology ; Kenya ; Molecular Typing ; Phylogeny ; *Symbiosis ; }, abstract = {Ticks are blood-feeding arthropods and can harbor several bacteria, including the worldwide zoonotic disease Q-fever agent Coxiella burnetii. Recent studies have reported a distinct group of Coxiella mostly associated with Ixodidae ticks, including the primary endosymbionts of Amblyomma americanum. In the present work, a screening for Coxiella infection was performed by 16S ribosomal DNA (rDNA) gene analyses in 293 tick samples of 15 different species sampled worldwide, including Brazil, Colombia, Kenya, and China. Different Coxiella phylotypes were identified, and these putative symbiotic bacteria were detected in ten different Amblyomma tick species. Approximately 61 % of Rhipicephalus sanguineus and ∼37 % of Rhipicephalus microplus DNA samples were positive for Coxiella. Sequence analysis and phylogenetic reconstruction grouped all the detected Coxiella with Coxiella-like symbionts from different Ixodidae ticks. This well-defined clade clearly excludes known phylotypes of C. burnetii pathogens and other Coxiella spp. detected in different environmental samples and other invertebrate hosts.}, }
@article {pmid27593513, year = {2016}, author = {Eren, RO and Reverte, M and Rossi, M and Hartley, MA and Castiglioni, P and Prevel, F and Martin, R and Desponds, C and Lye, LF and Drexler, SK and Reith, W and Beverley, SM and Ronet, C and Fasel, N}, title = {Mammalian Innate Immune Response to a Leishmania-Resident RNA Virus Increases Macrophage Survival to Promote Parasite Persistence.}, journal = {Cell host &amp; microbe}, volume = {20}, number = {3}, pages = {318-328}, pmid = {27593513}, issn = {1934-6069}, support = {R01 AI029646/AI/NIAID NIH HHS/United States ; R56 AI099364/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cell Survival ; Disease Models, Animal ; *Immunity, Innate ; Leishmania guyanensis/pathogenicity/physiology/*virology ; Leishmaniasis, Mucocutaneous/parasitology/pathology ; Leishmaniavirus/*immunology ; Macrophages/immunology/*parasitology ; Mice ; Mice, Knockout ; MicroRNAs/*metabolism ; Proto-Oncogene Proteins c-akt/*metabolism ; Toll-Like Receptor 3/*metabolism ; }, abstract = {Some strains of the protozoan parasite Leishmania guyanensis (L.g) harbor a viral endosymbiont called Leishmania RNA virus 1 (LRV1). LRV1 recognition by TLR-3 increases parasite burden and lesion swelling in vivo. However, the mechanisms by which anti-viral innate immune responses affect parasitic infection are largely unknown. Upon investigating the mammalian host's response to LRV1, we found that miR-155 was singularly and strongly upregulated in macrophages infected with LRV1+ L.g when compared to LRV1- L.g. LRV1-driven miR-155 expression was dependent on TLR-3/TRIF signaling. Furthermore, LRV1-induced TLR-3 activation promoted parasite persistence by enhancing macrophage survival through Akt activation in a manner partially dependent on miR-155. Pharmacological inhibition of Akt resulted in a decrease in LRV1-mediated macrophage survival and consequently decreased parasite persistence. Consistent with these data, miR-155-deficient mice showed a drastic decrease in LRV1-induced disease severity, and lesional macrophages from these mice displayed reduced levels of Akt phosphorylation.}, }
@article {pmid27588381, year = {2016}, author = {Zolnik, CP and Prill, RJ and Falco, RC and Daniels, TJ and Kolokotronis, SO}, title = {Microbiome changes through ontogeny of a tick pathogen vector.}, journal = {Molecular ecology}, volume = {25}, number = {19}, pages = {4963-4977}, doi = {10.1111/mec.13832}, pmid = {27588381}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification ; Female ; Ixodes/*microbiology ; Larva/microbiology ; *Microbiota ; New York ; Nymph/microbiology ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/isolation &amp; purification ; }, abstract = {Blacklegged ticks (Ixodes scapularis) are one of the most important pathogen vectors in the United States, responsible for transmitting Lyme disease and other tick-borne diseases. The structure of a host's microbial community has the potential to affect the ecology and evolution of the host. We employed high-throughput sequencing of the 16S rRNA gene V3-V4 hypervariable regions in the first study to investigate the tick microbiome across all developmental stages (larvae, nymphs, adults). In addition to field-collected life stages, newly hatched laboratory-reared larvae were studied to determine the baseline microbial community structure and to assess transovarial transmission. We also targeted midguts and salivary glands due to their importance in pathogen maintenance and transmission. Over 100 000 sequences were produced per life stage replicate. Rickettsia was the most abundant bacterial genus across all sample types matching mostly the Ixodes rickettsial endosymbionts, and its proportion decreased as developmental stage progressed, with the exception of adult females that harboured a mean relative abundance of 97.9%. Laboratory-reared larvae displayed the lowest bacterial diversity, containing almost exclusively Rickettsia. Many of the remaining bacteria included genera associated with soil, water and plants, suggesting environmental acquisition while off-host. Female organs exhibited significantly different β-diversity than the whole tick from which they were derived. Our results demonstrate clear differences in both α- and β-diversity among tick developmental stages and between tick organs and the tick as a whole. Furthermore, field-acquired bacteria appear to be very important to the overall internal bacterial community of this tick species, with influence from the host bloodmeal appearing limited.}, }
@article {pmid27580393, year = {2016}, author = {Flores, FS and Costa, FB and Nava, S and Diaz, LA and Labruna, MB}, title = {Rickettsial infection in ticks infesting wild birds from two eco-regions of Argentina.}, journal = {Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria}, volume = {25}, number = {3}, pages = {378-382}, doi = {10.1590/S1984-29612016045}, pmid = {27580393}, issn = {1984-2961}, mesh = {Animals ; Argentina ; Birds/*parasitology ; Humans ; Rickettsia/*isolation &amp; purification ; Ticks/*microbiology ; }, abstract = {Several tick-borne Rickettsia species are recognized human pathogens in Argentina. Here we evaluated rickettsial infection in ticks collected on passerine birds during 2011-2012 in two eco-regions of Argentina. The ticks were processed by molecular analysis through polymerase chain reaction (PCR) detection and DNA sequencing of fragments of two rickettsial genes, gltA and ompA. A total of 594 tick specimens (532 larvae and 62 nymphs), representing at least 4 species (Amblyomma tigrinum, Ixodes pararicinus, Haemaphysalis juxtakochi, Haemaphysalis leporispalustris), were evaluated. At least one A. tigrinum larva, collected on Coryphospingus cucullatus in Chaco Seco, was infected with Rickettsia parkeri, whereas at least 12 larvae and 1 nymph of I. pararicinus, collected from Troglodytes aedon, Turdus amaurochalinus, Turdus rufiventris, C. cucullatus and Zonotrichia capensis, were infected with an undescribed Rickettsia agent, genetically related to several rickettsial endosymbionts of ticks of the Ixodes ricinus complex. R. parkeri is a recognized human pathogen in several American countries including Argentina, where a recent study incriminated A. tigrinum as the potential vector of R. parkeri to humans. Birds could play an important role in dispersing R. parkeri-infected A. tigrinum ticks. Additionally, we report for the first time a rickettsial agent infecting I. pararicinus ticks.}, }
@article {pmid27578848, year = {2017}, author = {Purssell, A and Lau, R and Boggild, AK}, title = {Azithromycin and Doxycycline Attenuation of Acanthamoeba Virulence in a Human Corneal Tissue Model.}, journal = {The Journal of infectious diseases}, volume = {215}, number = {8}, pages = {1303-1311}, doi = {10.1093/infdis/jiw410}, pmid = {27578848}, issn = {1537-6613}, mesh = {Acanthamoeba/*pathogenicity ; Amebiasis/drug therapy ; Azithromycin/*pharmacology ; Biomarkers/analysis ; Cells, Cultured ; Chlamydiaceae/*drug effects/genetics ; Cornea/*parasitology/pathology ; Cytokines/metabolism ; Doxycycline/*pharmacology ; Humans ; Keratitis/*parasitology ; RNA, Ribosomal, 16S/genetics ; Symbiosis/drug effects ; Virulence/drug effects ; }, abstract = {BACKGROUND: Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection.<br><br>METHODS: Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA. Each Acanthamoeba isolate was used to infect EpiCorneal cells, a 3-dimensional human corneal tissue model. EpiCorneal cells were then treated with azithromycin, doxycycline, or control medium to determine whether antibiotics targeting common classes of bacterial endosymbionts attenuated Acanthamoeba virulence, as indicated by decreased observed cytopathic effect and inflammatory biomarker production.<br><br>RESULTS: A novel endosymbiont closely related to Mycobacterium spp. was identified in Acanthamoeba polyphaga 50495. Infection of EpiCorneal cells with Acanthamoeba castellanii 50493 and A. polyphaga 50372 led to increased production of inflammatory cytokines and cytopathic effects visible under microscopy. These increases were attenuated by azithromycin and doxycycline.<br><br>CONCLUSIONS: Our findings suggest that azithromycin and doxycycline may be effective adjuvants to standard antiacanthamoebal chemotherapy by potentially abrogating virulence-enhancing properties of bacterial endosymbionts.}, }
@article {pmid27577790, year = {2016}, author = {Estrada-Navarrete, G and Cruz-Mireles, N and Lascano, R and Alvarado-Affantranger, X and Hernández-Barrera, A and Barraza, A and Olivares, JE and Arthikala, MK and Cárdenas, L and Quinto, C and Sanchez, F}, title = {An Autophagy-Related Kinase Is Essential for the Symbiotic Relationship between Phaseolus vulgaris and Both Rhizobia and Arbuscular Mycorrhizal Fungi.}, journal = {The Plant cell}, volume = {28}, number = {9}, pages = {2326-2341}, pmid = {27577790}, issn = {1532-298X}, abstract = {Eukaryotes contain three types of lipid kinases that belong to the phosphatidylinositol 3-kinase (PI3K) family. In plants and Saccharomyces cerevisiae, only PI3K class III family members have been identified. These enzymes regulate the innate immune response, intracellular trafficking, autophagy, and senescence. Here, we report that RNAi-mediated downregulation of common bean (Phaseolus vulgaris) PI3K severely impaired symbiosis in composite P. vulgaris plants with endosymbionts such as Rhizobium tropici and Rhizophagus irregularis Downregulation of Pv-PI3K was associated with a marked decrease in root hair growth and curling. Additionally, infection thread growth, root-nodule number, and symbiosome formation in root nodule cells were severely affected. Interestingly, root colonization by AM fungi and the formation of arbuscules were also abolished in PI3K loss-of-function plants. Furthermore, the transcript accumulation of genes encoding proteins known to interact with PI3K to form protein complexes involved in autophagy was drastically reduced in these transgenic roots. RNAi-mediated downregulation of one of these genes, Beclin1/Atg6, resulted in a similar phenotype as observed for transgenic roots in which Pv-PI3K had been downregulated. Our findings show that an autophagy-related process is crucial for the mutualistic interactions of P. vulgaris with beneficial microorganisms.}, }
@article {pmid27573819, year = {2016}, author = {Husnik, F and McCutcheon, JP}, title = {Repeated replacement of an intrabacterial symbiont in the tripartite nested mealybug symbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {37}, pages = {E5416-24}, pmid = {27573819}, issn = {1091-6490}, mesh = {Animals ; Betaproteobacteria/*genetics/growth &amp; development ; Gammaproteobacteria/*genetics/growth &amp; development ; Gene Transfer, Horizontal/genetics ; Genome, Bacterial ; Phylogeny ; Planococcus Insect/genetics/*microbiology ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Stable endosymbiosis of a bacterium into a host cell promotes cellular and genomic complexity. The mealybug Planococcus citri has two bacterial endosymbionts with an unusual nested arrangement: the γ-proteobacterium Moranella endobia lives in the cytoplasm of the β-proteobacterium Tremblaya princeps These two bacteria, along with genes horizontally transferred from other bacteria to the P. citri genome, encode gene sets that form an interdependent metabolic patchwork. Here, we test the stability of this three-way symbiosis by sequencing host and symbiont genomes for five diverse mealybug species and find marked fluidity over evolutionary time. Although Tremblaya is the result of a single infection in the ancestor of mealybugs, the γ-proteobacterial symbionts result from multiple replacements of inferred different ages from related but distinct bacterial lineages. Our data show that symbiont replacement can happen even in the most intricate symbiotic arrangements and that preexisting horizontally transferred genes can remain stable on genomes in the face of extensive symbiont turnover.}, }
@article {pmid27565956, year = {2016}, author = {Novakova, M and Costa, FB and Krause, F and Literak, I and Labruna, MB}, title = {Rickettsia vini n. sp. (Rickettsiaceae) infecting the tick Ixodes arboricola (Acari: Ixodidae).}, journal = {Parasites &amp; vectors}, volume = {9}, number = {1}, pages = {469}, pmid = {27565956}, issn = {1756-3305}, mesh = {Animals ; Chickens ; Chlorocebus aethiops ; Czech Republic ; Genotype ; Guinea Pigs ; Host-Pathogen Interactions ; Ixodes/*microbiology ; Male ; Phylogeny ; Poultry Diseases/microbiology ; Rickettsia/*genetics/*isolation &amp; purification ; Rickettsia Infections/microbiology/veterinary ; Vero Cells ; }, abstract = {BACKGROUND: Recently, a new rickettsia named 'Candidatus Rickettsia vini' belonging to the spotted fever group has been molecularly detected in Ixodes arboricola ticks in Spain, the Czech Republic, Slovakia and Turkey, with prevalence reaching up to 100 %. The aim of this study was to isolate this rickettsia in pure culture, and to describe it as a new Rickettsia species.<br><br>METHODS: A total of 148 ornitophilic nidicolous ticks Ixodes arboricola were collected in a forest near Breclav (Czech Republic) and examined for rickettsiae. Shell vial technique was applied to isolate rickettsiae in Vero cells. Rickettsial isolation was confirmed by optical microscopy and sequencing of partial sequences of the rickettsial genes gltA, ompA, ompB, and htrA. Laboratory guinea pigs and chickens were used for experimental infestations and infections. Animal blood sera were tested by immunofluorescence assay employing crude antigens of various rickettsiae.<br><br>RESULTS: Rickettsia vini n. sp. was successfully isolated from three males of I. arboricola. Phylogenetic analysis of fragments of 1092, 590, 800, and 497 nucleotides of the gltA, ompA, ompB, and htrA genes, respectively, showed closest proximity of R. vini n. sp. to Rickettsia japonica and Rickettsia heilongjiangensis belonging to the spotted fever group. Experimental infection of guinea pigs and chickens with R. vini led to various levels of cross-reactions of R. vini-homologous antibodies with Rickettsia rickettsii, Rickettsia parkeri, 'Candidatus Rickettsia amblyommii', Rickettsia rhipicephali, Rickettsia bellii, and Rickettsia felis. Laboratory infestations by R. vini-infected I. arboricola larvae on chickens led to no seroconversion to R. vini n. sp., nor cross-reactions with R. rickettsii, R. parkeri, 'Ca. R. amblyommii', R. rhipicephali, R. bellii or R. felis.<br><br>CONCLUSIONS: Our results suggest that R. vini n. sp. is possibly a tick endosymbiont, not pathogenic for guinea pigs and chickens. Regarding specific phenotypic characters and significant differences of DNA sequences in comparison to the most closely related species (R. japonica and R. heilongjiangensis), we propose to classify the isolate as a new species, Rickettsia vini.}, }
@article {pmid27547523, year = {2016}, author = {Allen, JM and Burleigh, JG and Light, JE and Reed, DL}, title = {Effects of 16S rDNA sampling on estimates of the number of endosymbiont lineages in sucking lice.}, journal = {PeerJ}, volume = {4}, number = {}, pages = {e2187}, pmid = {27547523}, issn = {2167-8359}, abstract = {Phylogenetic trees can reveal the origins of endosymbiotic lineages of bacteria and detect patterns of co-evolution with their hosts. Although taxon sampling can greatly affect phylogenetic and co-evolutionary inference, most hypotheses of endosymbiont relationships are based on few available bacterial sequences. Here we examined how different sampling strategies of Gammaproteobacteria sequences affect estimates of the number of endosymbiont lineages in parasitic sucking lice (Insecta: Phthirapatera: Anoplura). We estimated the number of louse endosymbiont lineages using both newly obtained and previously sequenced 16S rDNA bacterial sequences and more than 42,000 16S rDNA sequences from other Gammaproteobacteria. We also performed parametric and nonparametric bootstrapping experiments to examine the effects of phylogenetic error and uncertainty on these estimates. Sampling of 16S rDNA sequences affects the estimates of endosymbiont diversity in sucking lice until we reach a threshold of genetic diversity, the size of which depends on the sampling strategy. Sampling by maximizing the diversity of 16S rDNA sequences is more efficient than randomly sampling available 16S rDNA sequences. Although simulation results validate estimates of multiple endosymbiont lineages in sucking lice, the bootstrap results suggest that the precise number of endosymbiont origins is still uncertain.}, }
@article {pmid27547307, year = {2016}, author = {Bunning, H and Bassett, L and Clowser, C and Rapkin, J and Jensen, K and House, CM and Archer, CR and Hunt, J}, title = {Dietary choice for a balanced nutrient intake increases the mean and reduces the variance in the reproductive performance of male and female cockroaches.}, journal = {Ecology and evolution}, volume = {6}, number = {14}, pages = {4711-4730}, pmid = {27547307}, issn = {2045-7758}, abstract = {Sexual selection may cause dietary requirements for reproduction to diverge across the sexes and promote the evolution of different foraging strategies in males and females. However, our understanding of how the sexes regulate their nutrition and the effects that this has on sex-specific fitness is limited. We quantified how protein (P) and carbohydrate (C) intakes affect reproductive traits in male (pheromone expression) and female (clutch size and gestation time) cockroaches (Nauphoeta cinerea). We then determined how the sexes regulate their intake of nutrients when restricted to a single diet and when given dietary choice and how this affected expression of these important reproductive traits. Pheromone levels that improve male attractiveness, female clutch size and gestation time all peaked at a high daily intake of P:C in a 1:8 ratio. This is surprising because female insects typically require more P than males to maximize reproduction. The relatively low P requirement of females may reflect the action of cockroach endosymbionts that help recycle stored nitrogen for protein synthesis. When constrained to a single diet, both sexes prioritized regulating their daily intake of P over C, although this prioritization was stronger in females than males. When given the choice between diets, both sexes actively regulated their intake of nutrients at a 1:4.8 P:C ratio. The P:C ratio did not overlap exactly with the intake of nutrients that optimized reproductive trait expression. Despite this, cockroaches of both sexes that were given dietary choice generally improved the mean and reduced the variance in all reproductive traits we measured relative to animals fed a single diet from the diet choice pair. This pattern was not as strong when compared to the single best diet in our geometric array, suggesting that the relationship between nutrient balancing and reproduction is complex in this species.}, }
@article {pmid27543297, year = {2016}, author = {Ramírez-Puebla, ST and Ormeño-Orrillo, E and Vera-Ponce de León, A and Lozano, L and Sanchez-Flores, A and Rosenblueth, M and Martínez-Romero, E}, title = {Genomes of Candidatus Wolbachia bourtzisii wDacA and Candidatus Wolbachia pipientis wDacB from the Cochineal Insect Dactylopius coccus (Hemiptera: Dactylopiidae).}, journal = {G3 (Bethesda, Md.)}, volume = {6}, number = {10}, pages = {3343-3349}, pmid = {27543297}, issn = {2160-1836}, mesh = {Animals ; Bacterial Secretion Systems/genetics/metabolism ; Biological Transport ; Energy Metabolism ; Female ; Genetic Variation ; *Genome, Bacterial ; *Genomics/methods ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing ; RNA, Bacterial ; RNA, Ribosomal, 16S ; Stress, Physiological/genetics ; Symbiosis ; Virulence Factors ; Wolbachia/classification/*genetics/isolation &amp; purification/metabolism ; }, abstract = {Dactylopius species, known as cochineal insects, are the source of the carminic acid dye used worldwide. The presence of two Wolbachia strains in Dactylopius coccus from Mexico was revealed by PCR amplification of wsp and sequencing of 16S rRNA genes. A metagenome analysis recovered the genome sequences of Candidatus Wolbachia bourtzisii wDacA (supergroup A) and Candidatus Wolbachia pipientis wDacB (supergroup B). Genome read coverage, as well as 16S rRNA clone sequencing, revealed that wDacB was more abundant than wDacA. The strains shared similar predicted metabolic capabilities that are common to Wolbachia, including riboflavin, ubiquinone, and heme biosynthesis, but lacked other vitamin and cofactor biosynthesis as well as glycolysis, the oxidative pentose phosphate pathway, and sugar uptake systems. A complete tricarboxylic acid cycle and gluconeogenesis were predicted as well as limited amino acid biosynthesis. Uptake and catabolism of proline were evidenced in Dactylopius Wolbachia strains. Both strains possessed WO-like phage regions and type I and type IV secretion systems. Several efflux systems found suggested the existence of metal toxicity within their host. Besides already described putative virulence factors like ankyrin domain proteins, VlrC homologs, and patatin-like proteins, putative novel virulence factors related to those found in intracellular pathogens like Legionella and Mycobacterium are highlighted for the first time in Wolbachia Candidate genes identified in other Wolbachia that are likely involved in cytoplasmic incompatibility were found in wDacB but not in wDacA.}, }
@article {pmid27531180, year = {2016}, author = {Takahashi, T}, title = {Simultaneous Evaluation of Life Cycle Dynamics between a Host Paramecium and the Endosymbionts of Paramecium bursaria Using Capillary Flow Cytometry.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {31638}, pmid = {27531180}, issn = {2045-2322}, mesh = {Animals ; Biological Evolution ; Cell Cycle ; Chlorella/cytology/*physiology ; Flow Cytometry/methods ; Life Cycle Stages/physiology ; Multivariate Analysis ; Paramecium/growth &amp; development/*microbiology/*physiology ; Symbiosis/*physiology ; }, abstract = {Endosymbioses are driving forces underlying cell evolution. The endosymbiosis exhibited by Paramecium bursaria is an excellent model with which to study symbiosis. A single-cell microscopic analysis of P. bursaria reveals that endosymbiont numbers double when the host is in the division phase. Consequently, endosymbionts must arrange their cell cycle schedule if the culture-condition-dependent change delays the generation time of P. bursaria. However, it remains poorly understood whether endosymbionts keep pace with the culture-condition-dependent behaviors of P. bursaria, or not. Using microscopy and flow cytometry, this study investigated the life cycle behaviors occurring between endosymbionts and the host. To establish a connection between the host cell cycle and endosymbionts comprehensively, multivariate analysis was applied. The multivariate analysis revealed important information related to regulation between the host and endosymbionts. Results show that dividing endosymbionts underwent transition smoothly from the division phase to interphase, when the host was in the logarithmic phase. In contrast, endosymbiont division stagnated when the host was in the stationary phase. This paper explains that endosymbionts fine-tune their cell cycle pace with their host and that a synchronous life cycle between the endosymbionts and the host is guaranteed in the symbiosis of P. bursaria.}, }
@article {pmid27524990, year = {2016}, author = {González-Guerrero, M and Escudero, V and Saéz, &#xc1; and Tejada-Jiménez, M}, title = {Transition Metal Transport in Plants and Associated Endosymbionts: Arbuscular Mycorrhizal Fungi and Rhizobia.}, journal = {Frontiers in plant science}, volume = {7}, number = {}, pages = {1088}, pmid = {27524990}, issn = {1664-462X}, abstract = {Transition metals such as iron, copper, zinc, or molybdenum are essential nutrients for plants. These elements are involved in almost every biological process, including photosynthesis, tolerance to biotic and abiotic stress, or symbiotic nitrogen fixation. However, plants often grow in soils with limiting metallic oligonutrient bioavailability. Consequently, to ensure the proper metal levels, plants have developed a complex metal uptake and distribution system, that not only involves the plant itself, but also its associated microorganisms. These microorganisms can simply increase metal solubility in soils and making them more accessible to the host plant, as well as induce the plant metal deficiency response, or directly deliver transition elements to cortical cells. Other, instead of providing metals, can act as metal sinks, such as endosymbiotic rhizobia in legume nodules that requires relatively large amounts to carry out nitrogen fixation. In this review, we propose to do an overview of metal transport mechanisms in the plant-microbe system, emphasizing the role of arbuscular mycorrhizal fungi and endosymbiotic rhizobia.}, }
@article {pmid27518440, year = {2016}, author = {Strassert, JFH and Mikaelyan, A and Woyke, T and Brune, A}, title = {Genome analysis of 'Candidatus Ancillula trichonymphae', first representative of a deep-branching clade of Bifidobacteriales, strengthens evidence for convergent evolution in flagellate endosymbionts.}, journal = {Environmental microbiology reports}, volume = {8}, number = {5}, pages = {865-873}, doi = {10.1111/1758-2229.12451}, pmid = {27518440}, issn = {1758-2229}, abstract = {The flagellate protists in the hindgut of lower termites play an essential role in the digestion of lignocellulose. Most flagellate species are associated with host-specific symbionts from various bacterial lineages, which typically lack cultured representatives. In this study, we analyzed the genome of 'Candidatus Ancillula trichonymphae', an endosymbiont of Trichonympha flagellates from dry-wood termites, which represents a novel, family-level lineage of uncultured Actinobacteria encountered so far only in termite guts. The draft genome of 'Ca. A. trichonymphae' (ca. 1.48 Mbp; 95% complete) revealed a purely fermentative metabolism that is probably fueled by xylose, N-acetyl-glucosamine and glycerol 3-phosphate acquired from the flagellate host. The absence of fructose bisphosphate aldolase and the presence of a complete gene set encoding the phosphoketolase pathway underscore the sister position of the new lineage to Bifidobacteriaceae. The preservation of the pathways for the assimilation of ammonia and the synthesis of 18 amino acids and several cofactors and vitamins suggests that 'Ca. A. trichonymphae' - like other endosymbionts of termite gut flagellates - provides essential amino acids and vitamins to its host. Our findings corroborate the emerging concept that numerous lineages of unrelated flagellate endosymbionts have convergently evolved to fill similar ecological niches.}, }
@article {pmid27510768, year = {2017}, author = {Greiman, SE and Vaughan, JA and Elmahy, R and Adisakwattana, P and Van Ha, N and Fayton, TJ and Khalil, AI and Tkach, VV}, title = {Real-time PCR detection and phylogenetic relationships of Neorickettsia spp. in digeneans from Egypt, Philippines, Thailand, Vietnam and the United States.}, journal = {Parasitology international}, volume = {66}, number = {1}, pages = {1003-1007}, pmid = {27510768}, issn = {1873-0329}, support = {R15 AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cestode Infections/parasitology/veterinary ; Chaperonin 60/genetics ; Chiroptera/microbiology/parasitology ; Egypt ; Fishes/microbiology/parasitology ; Genotype ; Host-Parasite Interactions ; Humans ; Neorickettsia/*classification/genetics/*isolation &amp; purification ; Philippines ; Phylogeny ; Platyhelminths/*microbiology ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; Thailand/epidemiology ; Trematode Infections/parasitology/veterinary ; United States/epidemiology ; Vietnam/epidemiology ; }, abstract = {Neorickettsia (Rickettsiales, Anaplasmataceae) is a genus of obligate intracellular bacterial endosymbionts of digeneans (Platyhelminthes, Digenea). Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of domestic animals, wildlife, and humans. In this study we report the results of screening digenean samples for Neorickettsia collected from bats in Egypt and Mindoro Island, Philippines, snails and fishes from Thailand, and fishes from Vietnam and the USA. Neorickettsia were detected using a real-time PCR protocol targeting a 152bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1853bp long region of the GroESL operon and a 1371bp long region of 16S rRNA. Eight unique genotypes of Neorickettsia were obtained from digenean samples. Neorickettsia sp. 8 obtained from Lecithodendrium sp. from Egypt; Neorickettsia sp. 9 and 10 obtained from two species of Paralecithodendrium from Mindoro, Philippines; Neorickettsia sp. 11 from Lecithodendrium sp. and Neorickettsia sp. 4 (previously identified from Saccocoelioides lizae, from China) from Thailand; Neorickettsia sp. 12 from Dicrogaster sp. Florida, USA; Neorickettsia sp. 13 and SF agent from Vietnam. Sequence comparison and phylogenetic analysis demonstrated that the forms, provisionally named Neorickettsia sp. 8-13, represent new genotypes. We have for the first time detected Neorickettsia in a digenean from Egypt (and the African continent as a whole), the Philippines, Thailand and Vietnam based on PCR and sequencing evidence. Our findings suggest that further surveys from the African continent, SE Asia, and island countries are likely to reveal new Neorickettsia lineages as well as new digenean host associations.}, }
@article {pmid27503292, year = {2016}, author = {Suzuki, S and Ishida, K and Hirakawa, Y}, title = {Diurnal Transcriptional Regulation of Endosymbiotically Derived Genes in the Chlorarachniophyte Bigelowiella natans.}, journal = {Genome biology and evolution}, volume = {8}, number = {9}, pages = {2672-2682}, pmid = {27503292}, issn = {1759-6653}, mesh = {*Circadian Rhythm ; *Gene Expression Regulation, Plant ; Nuclear Proteins/genetics/metabolism ; Plant Proteins/*genetics/metabolism ; Rhizaria/*genetics/metabolism ; *Transcriptome ; }, abstract = {Chlorarachniophyte algae possess complex plastids acquired by the secondary endosymbiosis of a green alga, and the plastids harbor a relict nucleus of the endosymbiont, the so-called nucleomorph. Due to massive gene transfer from the endosymbiont to the host, many proteins involved in plastid and nucleomorph are encoded by the nuclear genome. Genome sequences have provided a blueprint for the fate of endosymbiotically derived genes; however, transcriptional regulation of these genes remains poorly understood. To gain insight into the evolution of endosymbiotic genes, we performed genome-wide transcript profiling along the cell cycle of the chlorarachniophyte Bigelowiella natans, synchronized by light and dark cycles. Our comparative analyses demonstrated that transcript levels of 7,751 nuclear genes (35.7% of 21,706 genes) significantly oscillated along the diurnal/cell cycles, and those included 780 and 147 genes for putative plastid and nucleomorph-targeted proteins, respectively. Clustering analysis of those genes revealed the existence of transcriptional networks related to specific biological processes such as photosynthesis, carbon metabolism, translation, and DNA replication. Interestingly, transcripts of many plastid-targeted proteins in B. natans were induced before dawn, unlike other photosynthetic organisms. In contrast to nuclear genes, 99% nucleomorph genes were found to be constitutively expressed during the cycles. We also found that the nucleomorph DNA replication would be controlled by a nucleus-encoded viral-like DNA polymerase. The results of this study suggest that nucleomorph genes have lost transcriptional regulation along the diurnal cycles, and nuclear genes exert control over the complex plastid including the nucleomorph.}, }
@article {pmid27493203, year = {2016}, author = {Yuyama, I and Higuchi, T and Takei, Y}, title = {Sulfur utilization of corals is enhanced by endosymbiotic algae.}, journal = {Biology open}, volume = {5}, number = {9}, pages = {1299-1304}, pmid = {27493203}, issn = {2046-6390}, abstract = {Sulfur-containing compounds are important components of all organisms, but few studies have explored sulfate utilization in corals. Our previous study found that the expression of a sulfur transporter (SLC26A11) was upregulated in the presence of Symbiodinium cells in juveniles of the reef-building coral Acropora tenuis In this study, we performed autoradiography using (35)S-labeled sulfate ions ((35)SO4 (2-)) to examine the localization and amount of incorporated radioactive sulfate in the coral tissues and symbiotic algae. Incorporated (35)SO4 (2-) was detected in symbiotic algal cells, nematocysts, ectodermal cells and calicoblast cells. The combined results of (35)S autoradiography and Alcian Blue staining showed that incorporated (35)S accumulated as sulfated glycosaminoglycans (GAGs) in the ectodermal cell layer. We also compared the relative incorporation of (35)SO4 (2-) into coral tissues and endosymbiotic algae, and their chemical fractions in dark versus light (photosynthetic) conditions. The amount of sulfur compounds, such as GAGs and lipids, generated from (35)SO4 (2-) was higher under photosynthetic conditions. Together with the upregulation of sulfate transporters by symbiosis, our results suggest that photosynthesis of algal endosymbionts contributes to the synthesis and utilization of sulfur compounds in corals.}, }
@article {pmid27489552, year = {2016}, author = {Eleftheriadis, T and Pissas, G and Liakopoulos, V and Stefanidis, I}, title = {Cytochrome c as a Potentially Clinical Useful Marker of Mitochondrial and Cellular Damage.}, journal = {Frontiers in immunology}, volume = {7}, number = {}, pages = {279}, pmid = {27489552}, issn = {1664-3224}, abstract = {Mitochondria are evolutionary endosymbionts derived from bacteria. Thus, they bear molecules, such as mitochondrial DNA (mtDNA) that contains CpG DNA repeats and N-formyl peptides (FPs), found in bacteria. Upon cell necrosis or apoptosis, these molecules are released into the interstitial space and the circulation and recognized by the immune cells through the same receptors that recognize pathogen-associated molecular patterns, leading to inflammation. Other mitochondrial molecules are not of bacterial origin, but they may serve as danger-associated molecular patterns (DAMPs) when due to cell injury are translocated into inappropriate compartments. There they are recognized by pattern recognition receptors of the immune cells. Cytochrome c is such a molecule. In this review, experimental and clinical data are presented that confirms cytochrome c release into the extracellular space in pathological conditions characterized by cell death. This indicates that serum cytochrome c, which can be easily measured, may be a clinically useful marker for diagnosing and assessing the severity of such pathological entities. Reasonably, detection of high cytochrome c level into the circulation means release of various other molecules that serves as DAMPs when found extracellularly, the mtDNA and FPs included. Finally, because the release of this universally found compound into the extracellular space makes cytochrome c an ideal molecule to play the role of a DAMP per se, the available experimental and clinical data that support such a role are provided.}, }
@article {pmid27486438, year = {2016}, author = {Seston, SL and Beinart, RA and Sarode, N and Shockey, AC and Ranjan, P and Ganesh, S and Girguis, PR and Stewart, FJ}, title = {Metatranscriptional Response of Chemoautotrophic Ifremeria nautilei Endosymbionts to Differing Sulfur Regimes.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {1074}, pmid = {27486438}, issn = {1664-302X}, abstract = {Endosymbioses between animals and chemoautotrophic bacteria are ubiquitous at hydrothermal vents. These environments are distinguished by high physico-chemical variability, yet we know little about how these symbioses respond to environmental fluctuations. We therefore examined how the γ-proteobacterial symbionts of the vent snail Ifremeria nautilei respond to changes in sulfur geochemistry. Via shipboard high-pressure incubations, we subjected snails to 105 μM hydrogen sulfide (LS), 350 μM hydrogen sulfide (HS), 300 μM thiosulfate (TS) and seawater without any added inorganic electron donor (ND). While transcript levels of sulfur oxidation genes were largely consistent across treatments, HS and TS treatments stimulated genes for denitrification, nitrogen assimilation, and CO2 fixation, coincident with previously reported enhanced rates of inorganic carbon incorporation and sulfur oxidation in these treatments. Transcripts for genes mediating oxidative damage were enriched in the ND and LS treatments, potentially due to a reduction in O2 scavenging when electron donors were scarce. Oxidative TCA cycle gene transcripts were also more abundant in ND and LS treatments, suggesting that I. nautilei symbionts may be mixotrophic when inorganic electron donors are limiting. These data reveal the extent to which I. nautilei symbionts respond to changes in sulfur concentration and species, and, interpreted alongside coupled biochemical metabolic rates, identify gene targets whose expression patterns may be predictive of holobiont physiology in environmental samples.}, }
@article {pmid27483121, year = {2017}, author = {Stoecker, DK and Hansen, PJ and Caron, DA and Mitra, A}, title = {Mixotrophy in the Marine Plankton.}, journal = {Annual review of marine science}, volume = {9}, number = {}, pages = {311-335}, doi = {10.1146/annurev-marine-010816-060617}, pmid = {27483121}, issn = {1941-0611}, mesh = {Animals ; *Ecosystem ; Oceans and Seas ; Photosynthesis ; *Phytoplankton ; Plankton ; *Zooplankton ; }, abstract = {Mixotrophs are important components of the bacterioplankton, phytoplankton, microzooplankton, and (sometimes) zooplankton in coastal and oceanic waters. Bacterivory among the phytoplankton may be important for alleviating inorganic nutrient stress and may increase primary production in oligotrophic waters. Mixotrophic phytoflagellates and dinoflagellates are often dominant components of the plankton during seasonal stratification. Many of the microzooplankton grazers, including ciliates and Rhizaria, are mixotrophic owing to their retention of functional algal organelles or maintenance of algal endosymbionts. Phototrophy among the microzooplankton may increase gross growth efficiency and carbon transfer through the microzooplankton to higher trophic levels. Characteristic assemblages of mixotrophs are associated with warm, temperate, and cold seas and with stratification, fronts, and upwelling zones. Modeling has indicated that mixotrophy has a profound impact on marine planktonic ecosystems and may enhance primary production, biomass transfer to higher trophic levels, and the functioning of the biological carbon pump.}, }
@article {pmid27481779, year = {2016}, author = {McLean, AH and Parker, BJ and Hrček, J and Henry, LM and Godfray, HC}, title = {Insect symbionts in food webs.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {371}, number = {1702}, pages = {}, pmid = {27481779}, issn = {1471-2970}, mesh = {Animals ; Aphids/*microbiology/*physiology ; Bacteria/genetics ; *Bacterial Physiological Phenomena ; *Food Chain ; *Symbiosis ; }, abstract = {Recent research has shown that the bacterial endosymbionts of insects are abundant and diverse, and that they have numerous different effects on their hosts' biology. Here we explore how insect endosymbionts might affect the structure and dynamics of insect communities. Using the obligate and facultative symbionts of aphids as an example, we find that there are multiple ways that symbiont presence might affect food web structure. Many symbionts are now known to help their hosts escape or resist natural enemy attack, and others can allow their hosts to withstand abiotic stress or affect host plant use. In addition to the direct effect of symbionts on aphid phenotypes there may be indirect effects mediated through trophic and non-trophic community interactions. We believe that by using data from barcoding studies to identify bacterial symbionts, this extra, microbial dimension to insect food webs can be better elucidated.This article is part of the themed issue 'From DNA barcodes to biomes'.}, }
@article {pmid27479050, year = {2016}, author = {Garcia, Gde A and Dos Santos, LM and Villela, DA and Maciel-de-Freitas, R}, title = {Using Wolbachia Releases to Estimate Aedes aegypti (Diptera: Culicidae) Population Size and Survival.}, journal = {PloS one}, volume = {11}, number = {8}, pages = {e0160196}, pmid = {27479050}, issn = {1932-6203}, mesh = {Aedes/*microbiology ; Animals ; Brazil ; Female ; *Models, Theoretical ; Pest Control, Biological ; Population Density ; Wolbachia/*physiology ; }, abstract = {Mosquitoes carrying the endosymbiont bacterium Wolbachia have been deployed in field trials as a biological control intervention due to Wolbachia effects on reducing transmission of arboviruses. We performed mark, release and recapture (MRR) experiments using Wolbachia as an internal marker with daily collections with BG-Traps during the first two weeks of releases in Rio de Janeiro, Brazil. The MRR design allowed us to investigate two critical parameters that determine whether Wolbachia would successful invade a field population: the probability of daily survival (PDS) of Wolbachia-infected Aedes aegypti females, and the wild population density during releases. Released females had a PDS of 0.82 and 0.89 in the first and second weeks, respectively, immediately after releases, which is well within the range of previous estimates of survivorship of wild mosquitoes in Rio de Janeiro. Abundance estimation of wild population varied up to 10-fold higher depending on the estimation method used (634-3565 females on the average-difference model to 6365-16188 females according to Lincoln-Petersen). Wolbachia-released mosquitoes were lower than the density estimation of their wild counterparts, irrespectively of the model used. Individually screening mosquitoes for the presence of Wolbachia reduced uncertainty on abundance estimations due to fluctuation in capturing per week. A successful invasion into local population requires Ae. aegypti fitness is unaffected by Wolbachia presence, but also reliable estimates on the population size of wild mosquitoes.}, }
@article {pmid27473768, year = {2016}, author = {Calle-Espinosa, J and Ponce-de-Leon, M and Santos-Garcia, D and Silva, FJ and Montero, F and Peretó, J}, title = {Nature lessons: The whitefly bacterial endosymbiont is a minimal amino acid factory with unusual energetics.}, journal = {Journal of theoretical biology}, volume = {407}, number = {}, pages = {303-317}, doi = {10.1016/j.jtbi.2016.07.024}, pmid = {27473768}, issn = {1095-8541}, mesh = {Amino Acids/*metabolism ; Animals ; *Energy Metabolism ; Genome, Bacterial ; Halomonadaceae/genetics/*metabolism ; Hemiptera/*microbiology ; Metabolic Flux Analysis ; Metabolic Networks and Pathways ; Models, Biological ; *Symbiosis ; beta Carotene/metabolism ; }, abstract = {Reductive genome evolution is a universal phenomenon observed in endosymbiotic bacteria in insects. As the genome reduces its size and irreversibly losses coding genes, the functionalities of the cell system, including the energetics processes, are more restricted. Several energetic pathways can also be lost. How do these reduced metabolic networks sustain the energy needs of the system? Among the bacteria with reduced genomes Candidatus Portiera aleyrodidarum, obligate endosymbiont of whiteflies, represents an extreme case since lacks several key mechanisms for ATP generation. Thus, to analyze the cell energetics in this system, a genome-scale metabolic model of this endosymbiont was constructed, and its energy production capabilities dissected using stoichiometric analysis. Our results suggest that energy generation is coupled to the synthesis of essential amino acids and carotenoids, crucial metabolites in the symbiotic association. A deeper insight showed that ATP production via carotenoid synthesis is also connected with amino acid production. This unusual association of energy production with anabolism suggests that, although minimized, endosymbiont metabolic networks maintain a remarkable biosynthetic potential.}, }
@article {pmid27461737, year = {2016}, author = {Pietri, JE and DeBruhl, H and Sullivan, W}, title = {The rich somatic life of Wolbachia.}, journal = {MicrobiologyOpen}, volume = {5}, number = {6}, pages = {923-936}, pmid = {27461737}, issn = {2045-8827}, support = {R01 GM104486/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Arthropods/*microbiology ; *Disease Transmission, Infectious ; Host-Pathogen Interactions/*physiology ; Nematoda/*microbiology ; Wolbachia/*pathogenicity ; }, abstract = {Wolbachia is an intracellular endosymbiont infecting most arthropod and some filarial nematode species that is vertically transmitted through the maternal lineage. Due to this primary mechanism of transmission, most studies have focused on Wolbachia interactions with the host germline. However, over the last decade many studies have emerged highlighting the prominence of Wolbachia in somatic tissues, implicating somatic tissue tropism as an important aspect of the life history of this endosymbiont. Here, we review our current understanding of Wolbachia-host interactions at both the cellular and organismal level, with a focus on Wolbachia in somatic tissues.}, }
@article {pmid27461113, year = {2016}, author = {Lawrence, SA and Poulin, R}, title = {Detection of the bacterial endosymbiont Neorickettsia in a New Zealand digenean.}, journal = {Parasitology research}, volume = {115}, number = {11}, pages = {4275-4279}, pmid = {27461113}, issn = {1432-1955}, mesh = {Animals ; Asia ; Neorickettsia/genetics/*isolation &amp; purification ; New Zealand ; North America ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Snails/*parasitology ; Trematoda/*microbiology ; }, abstract = {Neorickettsia are endosymbiotic bacteria that infect digeneans (Trematoda). These bacteria are of interest worldwide because of their ability to move from the parasite to its host, where they can cause serious diseases of humans and animals. While several disease-forming species of Neorickettsia have been well studied, and numerous Neorickettsia types have been identified in regions such as North America and parts of Asia, records from other locations are sparse. To date, there have been no reports of Neorickettsia from New Zealand. We screened ten species of digeneans infecting seven native gastropod species (both marine and freshwater) found near Dunedin, New Zealand, for the presence of neorickettsial infections. A >1300 bp long section of 16S rRNA belonging to a Neorickettsia bacterium was isolated from opecoelid digeneans of two individuals of the mudflat topshell snail Diloma subrostrata. These sequences represent the first evidence of neorickettsial infection in native New Zealand animals and are also the first Neorickettsia found in digeneans of the family Opecoelidae.}, }
@article {pmid27460902, year = {2016}, author = {Budachetri, K and Gaillard, D and Williams, J and Mukherjee, N and Karim, S}, title = {A snapshot of the microbiome of Amblyomma tuberculatum ticks infesting the gopher tortoise, an endangered species.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {6}, pages = {1225-1229}, pmid = {27460902}, issn = {1877-9603}, support = {P20 GM103476/GM/NIGMS NIH HHS/United States ; R15 AI099910/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Endangered Species ; Female ; *Gastrointestinal Microbiome ; Gastrointestinal Tract ; Ixodidae/*microbiology ; Tick Infestations/parasitology/*veterinary ; Turtles/*parasitology ; }, abstract = {The gopher tortoise tick, Amblyomma tuberculatum, has a unique relationship with the gopher tortoise, Gopherus polyphemus, found in sandy habitats across the southeastern United States. We aimed to understand the overall bacterial community associated with A. tuberculatum while also focusing on spotted fever group Rickettsia. These tortoises in the Southern Mississippi region are a federally threatened species; therefore, we have carefully trapped the tortoises and removed the species-specific ticks attached to them. Genomic DNA was extracted from individual ticks and used to explore overall bacterial load using pyrosequencing of bacterial 16S rRNA on 454-sequencing platform. The spotted fever group of Rickettsia was explored by amplifying rickettsial outer membrane protein A (rompA) gene by nested PCR. Sequencing results revealed 330 bacterial operational taxonomic units (OTUs) after all the necessary curation of sequences. Four whole A. tuberculatum ticks showed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes as the most dominant phyla with a total of 74 different bacterial genera detected. Together Rickettsiae and Francisella showed >85% abundance, thus dominating the bacterial community structure. Partial sequences obtained from ompA amplicons revealed the presence of an uncharacterized Rickettsia similar to the Rickettsial endosymbiont of A. tuberculatum. This is the first preliminary profile of a complete bacterial community from gopher tortoise ticks and warrants further investigation regarding the functional role of Rickettsial and Francisella-like endosymbionts in tick physiology.}, }
@article {pmid27460796, year = {2016}, author = {Ramond, E and Maclachlan, C and Clerc-Rosset, S and Knott, GW and Lemaitre, B}, title = {Cell Division by Longitudinal Scission in the Insect Endosymbiont Spiroplasma poulsonii.}, journal = {mBio}, volume = {7}, number = {4}, pages = {}, pmid = {27460796}, issn = {2150-7511}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/analysis ; *Cell Division ; Cytoskeletal Proteins/analysis ; Drosophila melanogaster/*microbiology ; Hemolymph/*microbiology ; Microscopy, Electron ; Spiroplasma/chemistry/*cytology/drug effects/*growth &amp; development ; *Symbiosis ; }, abstract = {UNLABELLED: Spiroplasma bacteria are highly motile bacteria with no cell wall and a helical morphology. This clade includes many vertically transmitted insect endosymbionts, including Spiroplasma poulsonii, a natural endosymbiont of Drosophila melanogaster S. poulsonii bacteria are mainly found in the hemolymph of infected female flies and exhibit efficient vertical transmission from mother to offspring. As is the case for many facultative endosymbionts, S. poulsonii can manipulate the reproduction of its host; in particular, S. poulsonii induces male killing in Drosophila melanogaster Here, we analyze the morphology of S. poulsonii obtained from the hemolymph of infected Drosophila This endosymbiont was not only found as long helical filaments, as previously described, but was also found in a Y-shaped form. The use of electron microscopy, immunogold staining of the FtsZ protein, and antibiotic treatment unambiguously linked the Y shape of S. poulsonii to cell division. Observation of the Y shape in another Spiroplasma, S. citri, and anecdotic observations from the literature suggest that cell division by longitudinal scission might be prevalent in the Spiroplasma clade. Our study is the first to report the Y-shape mode of cell division in an endosymbiotic bacterium and adds Spiroplasma to the so far limited group of bacteria known to utilize this cell division mode.<br><br>IMPORTANCE: Most bacteria rely on binary fission, which involves elongation of the bacteria and DNA replication, followed by splitting into two parts. Examples of bacteria with a Y-shape longitudinal scission remain scarce. Here, we report that Spiroplasma poulsonii, an endosymbiotic bacterium living inside the fruit fly Drosophila melanogaster, divide with the longitudinal mode of cell division. Observations of the Y shape in another Spiroplasma, S. citri, suggest that this mode of scission might be prevalent in the Spiroplasma clade. Spiroplasma bacteria are wall-less bacteria with a distinctive helical shape, and these bacteria are always associated with arthropods, notably insects. Our study raises the hypothesis that this mode of cell division by longitudinal scission could be linked to the symbiotic mode of life of these bacteria.}, }
@article {pmid27446181, year = {2016}, author = {Kaul, S and Sharma, T and K Dhar, M}, title = {"Omics" Tools for Better Understanding the Plant-Endophyte Interactions.}, journal = {Frontiers in plant science}, volume = {7}, number = {}, pages = {955}, pmid = {27446181}, issn = {1664-462X}, abstract = {Endophytes, which mostly include bacteria, fungi and actinomycetes, are the endosymbionts that reside asymptomatically in plants for at least a part of their life cycle. They have emerged as a valuable source of novel metabolites, industrially important enzymes and as stress relievers of host plant, but still many aspects of endophytic biology are unknown. Functions of individual endophytes are the result of their continuous and complex interactions with the host plant as well as other members of the host microbiome. Understanding plant microbiomes as a system allows analysis and integration of these complex interactions. Modern genomic studies involving metaomics and comparative studies can prove to be helpful in unraveling the gray areas of endophytism. A deeper knowledge of the mechanism of host infestation and role of endophytes could be exploited to improve the agricultural management in terms of plant growth promotion, biocontrol and bioremediation. Genome sequencing, comparative genomics, microarray, next gen sequencing, metagenomics, metatranscriptomics are some of the techniques that are being used or can be used to unravel plant-endophyte relationship. The modern techniques and approaches need to be explored to study endophytes and their putative role in host plant ecology. This review highlights "omics" tools that can be explored for understanding the role of endophytes in the plant microbiome.}, }
@article {pmid27437708, year = {2016}, author = {Rao, HC and Satish, S}, title = {Intra-specific differentiation of fungal endosymbiont Alternaria longissima CLB44 using RNA secondary structure analysis and their anti-infective potential.}, journal = {Die Naturwissenschaften}, volume = {103}, number = {7-8}, pages = {69}, pmid = {27437708}, issn = {1432-1904}, mesh = {Alternaria/*chemistry/classification/*genetics/isolation &amp; purification ; Anti-Infective Agents/pharmacology ; Bacteria/drug effects ; Combretaceae/microbiology ; Complex Mixtures/pharmacology ; DNA, Ribosomal Spacer/genetics ; RNA, Fungal/chemistry ; }, abstract = {New antimicrobial agents derived from endosymbio-tic fungi with unique and targeted mode of action are crucially rudimentary to combat multidrug-resistant infections. Most of the fungi isolated as endosymbionts show close morphological feature resemblance to plant pathogenic or free-living forms, and it is difficult to differentiate these different lifestyles. A fungal endosymbiont strain CLB44 was isolated from Combretum latifolium Blume (Combretaceae). CLB44 was then identified as Alternaria longissima based on morphological and internal transcribed spacer (ITS) intervening 5.8S rRNA gene sequence analysis. ITS2 RNA secondary structure analysis was carried out using mfold server with temperature 37 °C, and anti-infective potential was determined by MIC and disk diffusion methods. ITS2 RNA secondary structure analysis clearly distinguished endosymbiotic A. longissima CLB44 from free-living and pathogenic A. longissima members in the same monophyletic clade. Secondary metabolites produced effectively inhibited Pseudomonas aeruginosa (25 μg/ml), Escherichia coli (25 μg/ml), methicillin-resistant Staphylococcus aureus (50 μg/ml), Candida albicans (100 μg/ml), and other human pathogens. This study emerges as an innovative finding that explores newly revealed ITS2 RNAs that may be an insight as new markers for refining phylogenetic relations and to distinguish fungal endosymbionts with other free-living or pathogenic forms. A. longissima CLB44, in the emerging field of endosymbionts, will pave the way to a novel avenue in drug discovery to combat multidrug-resistant infections. The sequence data of this fungus is deposited in GenBank under the accession no. KU310611.}, }
@article {pmid27436554, year = {2016}, author = {Poelchau, MF and Coates, BS and Childers, CP and Peréz de León, AA and Evans, JD and Hackett, K and Shoemaker, D}, title = {Agricultural applications of insect ecological genomics.}, journal = {Current opinion in insect science}, volume = {13}, number = {}, pages = {61-69}, doi = {10.1016/j.cois.2015.12.002}, pmid = {27436554}, issn = {2214-5753}, mesh = {Agriculture/*methods/trends ; Animals ; Genome, Insect/*genetics ; Genome-Wide Association Study ; *Genomics/trends ; Insect Control/*methods ; Insecta/genetics ; }, abstract = {Agricultural entomology is poised to benefit from the application of ecological genomics, particularly the fields of biofuels generation and pest control. Metagenomic methods can characterize microbial communities of termites, wood-boring beetles and livestock pests, and transcriptomic approaches reveal molecular bases behind wood-digesting capabilities of these insects, leading to potential mechanisms for biofuel generation. Genome sequences are being exploited to develop new pest control methods, identify candidate antigens to vaccinate livestock, and discover RNAi target sequences and potential non-target effects in other insects. Gene content analyses of pest genome sequences and their endosymbionts suggest metabolic interdependencies between organisms, exposing potential gene targets for insect control. Finally, genome-wide association studies and genotyping by high-throughput sequencing promise to improve management of pesticide resistance.}, }
@article {pmid27428292, year = {2016}, author = {Assié, A and Borowski, C and van der Heijden, K and Raggi, L and Geier, B and Leisch, N and Schimak, MP and Dubilier, N and Petersen, JM}, title = {A specific and widespread association between deep-sea Bathymodiolus mussels and a novel family of Epsilonproteobacteria.}, journal = {Environmental microbiology reports}, volume = {8}, number = {5}, pages = {805-813}, doi = {10.1111/1758-2229.12442}, pmid = {27428292}, issn = {1758-2229}, abstract = {Bathymodiolus mussels dominate animal communities at many hydrothermal vents and cold seeps. Essential to the mussels' ecological and evolutionary success is their association with symbiotic methane- and sulfur-oxidizing gammaproteobacteria, which provide them with nutrition. In addition to these well-known gammaproteobacterial endosymbionts, we found epsilonproteobacterial sequences in metatranscriptomes, metagenomes and 16S rRNA clone libraries as well as by polymerase chain reaction screening of Bathymodiolus species sampled from vents and seeps around the world. These epsilonproteobacterial sequences were closely related, indicating that the association is highly specific. The Bathymodiolus-associated epsilonproteobacterial 16S rRNA sequences were at most 87.6% identical to the closest cultured relative, and 91.2% identical to the closest sequences in public databases. This clade therefore represents a novel family within the Epsilonproteobacteria. Fluorescence in situ hybridization and transmission electron microscopy showed that the bacteria are filamentous epibionts associated with the gill epithelia in two Bathymodiolus species. In animals that host highly specific symbioses with one or a few types of endosymbionts, other less-abundant members of the microbiota can be easily overlooked. Our work highlights how widespread and specific associations with less-abundant microbes can be. Possibly, these microbes play an important role in the survival and health of their animal hosts.}, }
@article {pmid27417081, year = {2016}, author = {Al-Abd, NM and Nor, ZM and Mansor, M and Hasan, MS and Kassim, M}, title = {Antifilarial and Antibiotic Activities of Methanolic Extracts of Melaleuca cajuputi Flowers.}, journal = {The Korean journal of parasitology}, volume = {54}, number = {3}, pages = {273-280}, pmid = {27417081}, issn = {1738-0006}, mesh = {Aedes ; Animals ; Anti-Bacterial Agents/isolation &amp; purification/*pharmacology ; Biological Assay ; Brugia pahangi/*drug effects ; Cell Line ; Female ; Filaricides/isolation &amp; purification/*pharmacology ; Flowers/*chemistry ; Locomotion/drug effects ; Male ; Melaleuca/*chemistry ; Methanol ; Microscopy, Electron ; Plant Extracts/isolation &amp; purification/*pharmacology ; Polymerase Chain Reaction ; Solvents ; Symbiosis/drug effects ; Wolbachia/*drug effects ; }, abstract = {We evaluated the activity of methanolic extracts of Melaleuca cajuputi flowers against the filarial worm Brugia pahangi and its bacterial endosymbiont Wolbachia. Anti-Wolbachia activity was measured in worms and in Aedes albopictus Aa23 cells by PCR, electron microscopy, and other biological assays. In particular, microfilarial release, worm motility, and viability were determined. M. cajuputi flower extracts were found to significantly reduce Wolbachia endosymbionts in Aa23 cells, Wolbachia surface protein, and microfilarial release, as well as the viability and motility of adult worms. Anti-Wolbachia activity was further confirmed by observation of degraded and phagocytized Wolbachia in worms treated with the flower extracts. The data provided in vitro and in vivo evidence that M. cajuputi flower extracts inhibit Wolbachia, an activity that may be exploited as an alternative strategy to treat human lymphatic filariasis.}, }
@article {pmid27416728, year = {2016}, author = {Stephenson, N and Wong, J and Foley, J}, title = {Host, habitat and climate preferences of Ixodes angustus (Acari: Ixodidae) and infection with Borrelia burgdorferi and Anaplasma phagocytophilum in California, USA.}, journal = {Experimental &amp; applied acarology}, volume = {70}, number = {2}, pages = {239-252}, pmid = {27416728}, issn = {1572-9702}, mesh = {Anaplasma phagocytophilum/*isolation &amp; purification ; Animals ; Bacterial Proteins/genetics ; Borrelia burgdorferi/*isolation &amp; purification ; California ; *Climate ; *Ecosystem ; *Host Specificity ; Ixodes/*microbiology/*physiology ; Population Density ; Sequence Analysis, DNA ; }, abstract = {The Holarctic tick Ixodes angustus is a competent vector for Borrelia burgdorferi, the etiologic agent of Lyme disease, and possibly Anaplasma phagocytophilum, the etiologic agent of granulocytic anaplasmosis, as well. From 2005 to 2013, we collected host-feeding I. angustus individuals from live-trapped small mammals and by flagging vegetation from 12 study sites in northern and central California, and tested for B. burgdorferi sensu lato, A. phagocytophilum, and Rickettsia spp. DNA by real-time PCR. Among 261 I. angustus collected (259 from hosts and two by flagging), the most common hosts were tree squirrels (20 % of ticks) and chipmunks (37 %). The PCR-prevalence for A. phagocytophilum and B. burgdorferi in ticks was 2 % and zero, respectively. The minimum infection prevalence on pooled DNA samples was 10 % for Rickettsia spp. DNA sequencing of the ompA gene identified this rickettsia as Candidatus Rickettsia angustus, a putative endosymbiont. A zero-inflated negative binomial mixed effects model was used to evaluate geographical and climatological predictors of I. angustus burden. When host species within study site and season within year were included in the model as nested random effects, all significant variables revealed that I. angustus burden increased as temperature decreased. Together with published data, these findings suggest that I. angustus is a host generalist, has a broad geographic distribution, is more abundant in areas with lower temperature within it's range, and is rarely infected with the pathogens A. phagocytophilum and B. burgdorferi.}, }
@article {pmid27406568, year = {2016}, author = {Paredes, JC and Herren, JK and Schüpfer, F and Lemaitre, B}, title = {The Role of Lipid Competition for Endosymbiont-Mediated Protection against Parasitoid Wasps in Drosophila.}, journal = {mBio}, volume = {7}, number = {4}, pages = {}, pmid = {27406568}, issn = {2150-7511}, mesh = {Animals ; Drosophila melanogaster/metabolism/*microbiology/*parasitology ; Hemolymph/chemistry ; Host-Parasite Interactions ; Hymenoptera/*growth &amp; development/*metabolism ; *Lipid Metabolism ; Lipids/analysis ; Spiroplasma/*growth &amp; development/*metabolism ; Symbiosis ; }, abstract = {UNLABELLED: Insects commonly harbor facultative bacterial endosymbionts, such as Wolbachia and Spiroplasma species, that are vertically transmitted from mothers to their offspring. These endosymbiontic bacteria increase their propagation by manipulating host reproduction or by protecting their hosts against natural enemies. While an increasing number of studies have reported endosymbiont-mediated protection, little is known about the mechanisms underlying this protection. Here, we analyze the mechanisms underlying protection from parasitoid wasps in Drosophila melanogaster mediated by its facultative endosymbiont Spiroplasma poulsonii Our results indicate that S. poulsonii exerts protection against two distantly related wasp species, Leptopilina boulardi and Asobara tabida S. poulsonii-mediated protection against parasitoid wasps takes place at the pupal stage and is not associated with an increased cellular immune response. In this work, we provide three important observations that support the notion that S. poulsonii bacteria and wasp larvae compete for host lipids and that this competition underlies symbiont-mediated protection. First, lipid quantification shows that both S. poulsonii and parasitoid wasps deplete D. melanogaster hemolymph lipids. Second, the depletion of hemolymphatic lipids using the Lpp RNA interference (Lpp RNAi) construct reduces wasp success in larvae that are not infected with S. poulsonii and blocks S. poulsonii growth. Third, we show that the growth of S. poulsonii bacteria is not affected by the presence of the wasps, indicating that when S. poulsonii is present, larval wasps will develop in a lipid-depleted environment. We propose that competition for host lipids may be relevant to endosymbiont-mediated protection in other systems and could explain the broad spectrum of protection provided.<br><br>IMPORTANCE: Virtually all insects, including crop pests and disease vectors, harbor facultative bacterial endosymbionts. They are vertically transmitted from mothers to their offspring, and some protect their host against pathogens. Here, we studied the mechanism of protection against parasitoid wasps mediated by the Drosophila melanogaster endosymbiont Spiroplasma poulsonii Using genetic manipulation of the host, we provide strong evidence supporting the hypothesis that competition for host lipids underlies S. poulsonii-mediated protection against parasitoid wasps. We propose that lipid competition-based protection may not be restricted to Spiroplasma bacteria but could also apply other endosymbionts, notably Wolbachia bacteria, which can suppress human disease-causing viruses in insect hosts.}, }
@article {pmid27393994, year = {2016}, author = {Wang, W and Zhai, Y and Cao, L and Tan, H and Zhang, R}, title = {Illumina-based analysis of core actinobacteriome in roots, stems, and grains of rice.}, journal = {Microbiological research}, volume = {190}, number = {}, pages = {12-18}, doi = {10.1016/j.micres.2016.05.003}, pmid = {27393994}, issn = {1618-0623}, mesh = {Actinobacteria/*classification/*genetics ; *Biodiversity ; Endophytes/classification/genetics ; High-Throughput Nucleotide Sequencing ; Oryza/*microbiology ; Plant Roots/microbiology ; Plant Stems/microbiology ; Seeds/microbiology ; }, abstract = {Seed-borne microbiota can transmit vertically from generation to generation and be a favour mutualism between the endosymbionts and hosts. The aim of this study was to investigate the rice-associated actinobacterial taxa in roots, stems, and grains and explore vertically transmitted core actinobacteriome of rice plants. Illumina sequencing analyses of samples of rice grains, stems, and roots showed that the roots contained the most diverse actinobacteria among the tissues. The grains contained 78 actinobacterial operational taxonomic units (OTUs), among which 44 were shared with those in the stems, 30 shared with those in the roots. The coexisted OTUs in the three types of samples mainly belong to genera of Pseudonocardia, Dietzia, Nocardioides, Streptomyces, Mycobacterium, Corynebacterium, Citricoccus, Salinibacterium, and Agrococcus, and other unclassified taxa. The dominant actinobacterial genera Pseudonocardia and Dietzia in the stems and roots were still detected in relatively high abundance in the grains. The Streptomyces isolated from surface sterilized grains could improve nitrogen use efficiency of rice seedlings and the resistance to rice blast fungus. The results suggested that the rice grains contained diverse actinobacterial taxa deriving from stems and roots and showed intimate correlation with the host plants.}, }
@article {pmid27392086, year = {2017}, author = {Neave, MJ and Rachmawati, R and Xun, L and Michell, CT and Bourne, DG and Apprill, A and Voolstra, CR}, title = {Differential specificity between closely related corals and abundant Endozoicomonas endosymbionts across global scales.}, journal = {The ISME journal}, volume = {11}, number = {1}, pages = {186-200}, pmid = {27392086}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/classification/*microbiology ; Coral Reefs ; Gammaproteobacteria/classification/genetics/isolation &amp; purification/*physiology ; Genotype ; In Situ Hybridization, Fluorescence ; *Symbiosis ; }, abstract = {Reef-building corals are well regarded not only for their obligate association with endosymbiotic algae, but also with prokaryotic symbionts, the specificity of which remains elusive. To identify the central microbial symbionts of corals, their specificity across species and conservation over geographic regions, we sequenced partial SSU ribosomal RNA genes of Bacteria and Archaea from the common corals Stylophora pistillata and Pocillopora verrucosa across 28 reefs within seven major geographical regions. We demonstrate that both corals harbor Endozoicomonas bacteria as their prevalent symbiont. Importantly, catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH) with Endozoicomonas-specific probes confirmed their residence as large aggregations deep within coral tissues. Using fine-scale genotyping techniques and single-cell genomics, we demonstrate that P. verrucosa harbors the same Endozoicomonas, whereas S. pistillata associates with geographically distinct genotypes. This specificity may be shaped by the different reproductive strategies of the hosts, potentially uncovering a pattern of symbiont selection that is linked to life history. Spawning corals such as P. verrucosa acquire prokaryotes from the environment. In contrast, brooding corals such as S. pistillata release symbiont-packed planula larvae, which may explain a strong regional signature in their microbiome. Our work contributes to the factors underlying microbiome specificity and adds detail to coral holobiont functioning.}, }
@article {pmid27377729, year = {2016}, author = {Plattner, H and Verkhratsky, A}, title = {Inseparable tandem: evolution chooses ATP and Ca2+ to control life, death and cellular signalling.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {371}, number = {1700}, pages = {}, pmid = {27377729}, issn = {1471-2970}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Adenosine Triphosphate/*metabolism ; Calcium/*metabolism ; Calcium Signaling ; Cell Communication ; Eukaryotic Cells/*physiology ; *Evolution, Molecular ; *Signal Transduction ; }, abstract = {From the very dawn of biological evolution, ATP was selected as a multipurpose energy-storing molecule. Metabolism of ATP required intracellular free Ca(2+) to be set at exceedingly low concentrations, which in turn provided the background for the role of Ca(2+) as a universal signalling molecule. The early-eukaryote life forms also evolved functional compartmentalization and vesicle trafficking, which used Ca(2+) as a universal signalling ion; similarly, Ca(2+) is needed for regulation of ciliary and flagellar beat, amoeboid movement, intracellular transport, as well as of numerous metabolic processes. Thus, during evolution, exploitation of atmospheric oxygen and increasingly efficient ATP production via oxidative phosphorylation by bacterial endosymbionts were a first step for the emergence of complex eukaryotic cells. Simultaneously, Ca(2+) started to be exploited for short-range signalling, despite restrictions by the preset phosphate-based energy metabolism, when both phosphates and Ca(2+) interfere with each other because of the low solubility of calcium phosphates. The need to keep cytosolic Ca(2+) low forced cells to restrict Ca(2+) signals in space and time and to develop energetically favourable Ca(2+) signalling and Ca(2+) microdomains. These steps in tandem dominated further evolution. The ATP molecule (often released by Ca(2+)-regulated exocytosis) rapidly grew to be the universal chemical messenger for intercellular communication; ATP effects are mediated by an extended family of purinoceptors often linked to Ca(2+) signalling. Similar to atmospheric oxygen, Ca(2+) must have been reverted from a deleterious agent to a most useful (intra- and extracellular) signalling molecule. Invention of intracellular trafficking further increased the role for Ca(2+) homeostasis that became critical for regulation of cell survival and cell death. Several mutually interdependent effects of Ca(2+) and ATP have been exploited in evolution, thus turning an originally unholy alliance into a fascinating success story.This article is part of the themed issue 'Evolution brings Ca(2+) and ATP together to control life and death'.}, }
@article {pmid27373707, year = {2016}, author = {Brune, A}, title = {Co-evolution of marine worms and their chemoautotrophic bacterial symbionts: unexpected host switches explained by ecological fitting?.}, journal = {Molecular ecology}, volume = {25}, number = {13}, pages = {2964-2966}, doi = {10.1111/mec.13688}, pmid = {27373707}, issn = {1365-294X}, mesh = {Animals ; Ecology ; Gammaproteobacteria/*classification ; Nematoda/microbiology ; *Phylogeny ; Symbiosis ; }, abstract = {Mutualistic associations of bacteria and invertebrates are widespread and encompass an enormous diversity on the side of both partners. The advantages gained from the symbiosis favour reciprocal adaptations that increase the stability of the association and can lead to codiversification of symbiont and host. While numerous examples of a strictly vertical transfer of the symbionts from parent to offspring among intracellular associations abound, little is known about the fidelity of the partners in extracellular associations, where symbionts colonize the surface or body cavity of their host. In this issue of Molecular Ecology, Zimmermann et al. () investigated the evolutionary history of the symbiotic association between a monophyletic clade of sulphur-oxidizing Gammaproteobacteria and two distantly related lineages of marine worms (nematodes and annelids). The study supports the surprising conclusion that partner fidelity does not necessarily increase with the intimacy of the association. Ectosymbionts on the cuticle of the nematodes seem to be cospeciating with their hosts, whereas endosymbionts housed in the body cavity of the annelids must have originated multiple times, probably by host switching, from ectosymbionts of sympatric nematodes. This excellent case study on the evolutionary history of invertebrate-microbe interactions supports the emerging concept that the co-evolutionary processes shaping such mutualistic symbioses include both codiversification and ecological fitting.}, }
@article {pmid27344110, year = {2016}, author = {Müller, A and Walochnik, J and Wagner, M and Schmitz-Esser, S}, title = {A clinical Acanthamoeba isolate harboring two distinct bacterial endosymbionts.}, journal = {European journal of protistology}, volume = {56}, number = {}, pages = {21-25}, doi = {10.1016/j.ejop.2016.04.002}, pmid = {27344110}, issn = {1618-0429}, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology/ultrastructure ; Alphaproteobacteria/classification/genetics/*physiology/ultrastructure ; Amebiasis/*parasitology ; Chlamydiales/classification/genetics/*physiology/ultrastructure ; Humans ; In Situ Hybridization, Fluorescence ; Keratitis/*parasitology ; Microscopy, Electron, Transmission ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Acanthamoebae feed on bacteria but are also frequent hosts of bacterial symbionts. Here, we describe the stable co-occurrence of two symbionts, one affiliated to the genus Parachlamydia and the other to the candidate genus Paracaedibacter (Alphaproteobacteria), within a clinical isolate of Acanthamoeba hatchetti genotype T4. We performed fluorescence in situ hybridization (FISH) and transmission electron microscopy (TEM) to describe this symbiosis. Our study adds to other reports of simultaneous co-occurrence of two symbionts within one Acanthamoeba cell.}, }
@article {pmid27342560, year = {2016}, author = {Christensen, S and Pérez Dulzaides, R and Hedrick, VE and Momtaz, AJ and Nakayasu, ES and Paul, LN and Serbus, LR}, title = {Wolbachia Endosymbionts Modify Drosophila Ovary Protein Levels in a Context-Dependent Manner.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {17}, pages = {5354-5363}, pmid = {27342560}, issn = {1098-5336}, support = {T34 GM083688/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila Proteins/genetics/*metabolism ; Drosophila melanogaster/genetics/*microbiology/*physiology ; Female ; Host-Pathogen Interactions ; Ovary/metabolism/microbiology ; Proteomics ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {UNLABELLED: Endosymbiosis is a unique form of interaction between organisms, with one organism dwelling inside the other. One of the most widespread endosymbionts is Wolbachia pipientis, a maternally transmitted bacterium carried by insects, crustaceans, mites, and filarial nematodes. Although candidate proteins that contribute to maternal transmission have been identified, the molecular basis for maternal Wolbachia transmission remains largely unknown. To investigate transmission-related processes in response to Wolbachia infection, ovarian proteomes were analyzed from Wolbachia-infected Drosophila melanogaster and D. simulans. Endogenous and variant host-strain combinations were investigated. Significant and differentially abundant ovarian proteins were detected, indicating substantial regulatory changes in response to Wolbachia Variant Wolbachia strains were associated with a broader impact on the ovary proteome than endogenous Wolbachia strains. The D. melanogaster ovarian environment also exhibited a higher level of diversity of proteomic responses to Wolbachia than D. simulans. Overall, many Wolbachia-responsive ovarian proteins detected in this study were consistent with expectations from the experimental literature. This suggests that context-specific changes in protein abundance contribute to Wolbachia manipulation of transmission-related mechanisms in oogenesis.<br><br>IMPORTANCE: Millions of insect species naturally carry bacterial endosymbionts called Wolbachia. Wolbachia bacteria are transmitted by females to their offspring through a robust egg-loading mechanism. The molecular basis for Wolbachia transmission remains poorly understood at this time, however. This proteomic study identified specific fruit fly ovarian proteins as being upregulated or downregulated in response to Wolbachia infection. The majority of these protein responses correlated specifically with the type of host and Wolbachia strain involved. This work corroborates previously identified factors and mechanisms while also framing the broader context of ovarian manipulation by Wolbachia.}, }
@article {pmid27318438, year = {2016}, author = {Wood, H and Dillon, L and Patel, SN and Ralevski, F}, title = {Prevalence of Rickettsia species in Dermacentor variabilis ticks from Ontario, Canada.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {5}, pages = {1044-1046}, doi = {10.1016/j.ttbdis.2016.06.001}, pmid = {27318438}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; Coxiella burnetii/genetics/isolation &amp; purification ; Dermacentor/*microbiology ; Francisella tularensis/genetics/isolation &amp; purification ; Ontario/epidemiology ; Polymerase Chain Reaction ; Prevalence ; Rickettsia/classification/genetics/*isolation &amp; purification/pathogenicity ; Rickettsia rickettsii/genetics/isolation &amp; purification ; }, abstract = {Relatively little is known about the prevalence of rickettsial species in Dermacentor ticks in eastern Canada. In this study, Dermacentor ticks from the province of Ontario, Canada, were tested for the presence of spotted fever group rickettsial (SFGR) species, Coxiella burnetii and Francisella tularensis. Rickettsia rickettsii was not detected in any ticks tested, but R. montanensis was detected at a prevalence of 2.2% in D. variabilis (17/778). Two other SFGR species, R. parkeri and Candidatus R. andeanae, were detected individually in 2 Amblyomma maculatum ticks. Rickettsia peacockii, a non-pathogenic endosymbiont, was detected in two D. andersonii ticks. Given the highly abundant nature of D. variabilis, surveillance for human pathogens in this species of tick has important public health implications, but the lack of detection of known human pathogens indicates a low risk of infection via this tick species in Ontario. However, the detection of R. parkeri in an adventive A. maculatum tick indicates that health care providers should be aware of the possibility of spotted fever rickettsioses in individuals with a history of travel outside of Ontario and symptoms compatible with a spotted fever rickettsiosis. Coxiella burnetii and Francisella tularensis, human pathogens also potentially transmitted by D. variabilis, were not detected in a subset of the ticks.}, }
@article {pmid27308293, year = {2016}, author = {Karami, M and Moosa-Kazemi, SH and Oshaghi, MA and Vatandoost, H and Sedaghat, MM and Rajabnia, R and Hosseini, M and Maleki-Ravasan, N and Yahyapour, Y and Ferdosi-Shahandashti, E}, title = {Wolbachia Endobacteria in Natural Populations of Culex pipiens of Iran and Its Phylogenetic Congruence.}, journal = {Journal of arthropod-borne diseases}, volume = {10}, number = {3}, pages = {347-363}, pmid = {27308293}, issn = {2322-1984}, abstract = {BACKGROUND: Wolbachia are common intracellular bacteria that infect different groups of arthropods including mosquitoes. These bacteria modify host biology and may induce feminization, parthenogenesis, male killing and cytoplasmic incompatibility (CI). Recently Wolbachia is being nominated as a bio-agent and paratransgenic candidate to control mosquito borne diseases.<br><br>METHODS: Here we report the results of a survey for presence, frequency, and phylogenetic congruence of these endosymbiont bacteria in Culex pipiens populations in Northern, Central, and Southern parts of Iran using nested-PCR amplification of wsp gene.<br><br>RESULTS: Wolbachia DNA were found in 227 (87.3%) out of 260 wild-caught mosquitoes. The rate of infection in adult females ranged from 61.5% to 100%, while in males were from 80% to 100%. The Blast search and phylogenetic analysis of the wsp gene sequence revealed that the Wolbachia strain from Iranian Cx. pipiens was identical to the Wolbachia strains of supergroup B previously reported in members of the Cx. pipiens complex. They had also identical sequence homology with the Wolbachia strains from a group of distinct arthropods including lepidopteran, wasps, flies, damselfly, thrips, and mites from remote geographical areas of the world.<br><br>CONCLUSION: It is suggested that Wolbachia strains horizontally transfer between unrelated host organisms over evolutionary time. Also results of this study indicates that Wolbachia infections were highly prevalent infecting all Cx. pipiens populations throughout the country, however further study needs to define Wolbachia inter-population reproductive incompatibility pattern and its usefulness as a bio-agent control measure.}, }
@article {pmid27297891, year = {2016}, author = {Martínez-Díaz, V and Latorre, A and Gil, R}, title = {Seasonal Changes in the Endosymbiotic Consortia of Aphids from the Genus Cinara.}, journal = {Microbes and environments}, volume = {31}, number = {2}, pages = {137-144}, pmid = {27297891}, issn = {1347-4405}, mesh = {Animals ; Aphids/*microbiology/radiation effects ; Buchnera/*isolation &amp; purification/*physiology ; Hot Temperature ; *Microbial Consortia ; Serratia/*isolation &amp; purification/*physiology ; *Symbiosis ; }, abstract = {Buchnera aphidicola is the primary endosymbiont of aphids with which it maintains an obligate mutualistic symbiotic relationship. Insects also maintain facultative symbiotic relationships with secondary symbionts, and Serratia symbiotica is the most common in aphids. The presence of both symbionts in aphids of the subfamily Lachninae has been widely studied by our group. We examined two closely related aphids, Cinara tujafilina and C. cedri in the present study. Even though both B. aphidicola strains have similar genome sizes and gene contents, the genomes of the two S. symbiotica strains were markedly different. The SCc strain has the smallest genome known for this species, while SCt possesses a larger genome in an intermediate stage between the facultative S. symbiotica of Acyrthosiphon pisum (SAp) and the co-obligate S. symbiotica SCc.Aphids are vulnerable to high temperatures. Previous studies indicated that S. symbiotica SAp confers resistance to heat-shock stress. In order to clarify whether S. symbiotica strains from genus Cinara also play a role in heat stress protection, we performed a quantitative determination of the consortium Buchnera/Serratia from two geographically close populations, each of which belonged to the Cinara species examined, over two years in natural environments. We found no variation in the consortium from our C. cedri population, but a positive correlation between both endosymbiont densities and average daily temperatures in the C. tujafilina population. Even though S. symbiotica SCt may retain some protective role against heat stress, this does not appear to be due to the release of protective metabolites by cell lysis.}, }
@article {pmid27297471, year = {2016}, author = {Hehenberger, E and Burki, F and Kolisko, M and Keeling, PJ}, title = {Functional Relationship between a Dinoflagellate Host and Its Diatom Endosymbiont.}, journal = {Molecular biology and evolution}, volume = {33}, number = {9}, pages = {2376-2390}, doi = {10.1093/molbev/msw109}, pmid = {27297471}, issn = {1537-1719}, mesh = {Biological Evolution ; Diatoms/genetics/microbiology ; Dinoflagellida/genetics/metabolism/*physiology ; High-Throughput Nucleotide Sequencing ; Phylogeny ; Plastids/genetics ; Structure-Activity Relationship ; Symbiosis/physiology ; }, abstract = {While we know much about the evolutionary patterns of endosymbiotic organelle origins, we know less about how the actual process unfolded within each system. This is partly due to the massive changes endosymbiosis appears to trigger, and partly because most organelles evolved in the distant past. The dinotoms are dinoflagellates with diatom endosymbionts, and they represent a relatively recent but nevertheless obligate endosymbiotic association. We have carried out deep sequencing of both the host and endosymbiont transcriptomes from two dinotoms, Durinskia baltica and Glenodinium foliaceum, to examine how the nucleocytosolic compartments have functionally integrated. This analysis showed little or no functional reduction in either the endosymbiont or host, and no evidence for genetic integration. Rather, host and endosymbiont seem to be bound to each other via metabolites, such as photosynthate exported from the endosymbiont to the host as indicated by the presence of plastidic phosphate translocators in the host transcriptome. The host is able to synthesize starch, using plant-specific starch synthases, as a way to store imported photosynthate.}, }
@article {pmid27291078, year = {2016}, author = {Zhang, YK and Chen, YT and Yang, K and Qiao, GX and Hong, XY}, title = {Screening of spider mites (Acari: Tetranychidae) for reproductive endosymbionts reveals links between co-infection and evolutionary history.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {27900}, pmid = {27291078}, issn = {2045-2322}, mesh = {Animals ; Bacteroidetes/classification/genetics/*physiology ; Biological Evolution ; Coinfection ; Electron Transport Complex IV/chemistry/genetics ; Host Specificity ; Phylogeny ; RNA, Ribosomal, 18S/chemistry/genetics ; RNA, Ribosomal, 28S/chemistry/genetics ; Reproduction ; Rickettsia/classification/genetics/*physiology ; Sequence Analysis, DNA ; Spiroplasma/classification/genetics/*physiology ; Symbiosis ; Tetranychidae/classification/genetics/*microbiology ; Wolbachia/classification/genetics/*physiology ; }, abstract = {Reproductive endosymbionts have been shown to have wide-ranging effects on many aspects of their hosts' biology. A first step to understanding how these endosymbionts interact with their hosts is to determine their incidences. Here, we screened for four reproductive endosymbionts (Wolbachia, Cardinium, Spiroplasma and Rickettsia) in 28 populations of spider mites (Acari: Tetranychidae) representing 12 species. Each of the four endosymbionts were identified in at least some of the tested specimens, and their infection patterns showed variations at the species-level and population-level, suggesting their distributions can be correlated with both the phylogeny and ecology of the hosts. Co-infections of unrelated bacteria, especially double infections of Wolbachia and Cardinium within the same individuals were common. Spiroplasma and Rickettsia infections were specific to particular host species, respectively. Further, the evolutionary histories of these endosymbionts were inferred by comparing the phylogenies of them and their hosts. These findings can help to clarify the interactions between endosymbionts and arthropods.}, }
@article {pmid27288365, year = {2016}, author = {Nishimura, K and Kato, Y and Sakamoto, W}, title = {Chloroplast Proteases: Updates on Proteolysis within and across Suborganellar Compartments.}, journal = {Plant physiology}, volume = {171}, number = {4}, pages = {2280-2293}, pmid = {27288365}, issn = {1532-2548}, mesh = {Arabidopsis/cytology/*enzymology/genetics ; Arabidopsis Proteins/genetics/metabolism ; Cell Nucleus/enzymology ; Chloroplasts/*enzymology ; Endopeptidases/genetics/metabolism ; Homeostasis ; Metalloendopeptidases/genetics/metabolism ; Models, Molecular ; Peptide Hydrolases/genetics/*metabolism ; Plant Proteins/genetics/metabolism ; Protein Transport ; *Proteolysis ; Proteome ; Thylakoids/enzymology ; }, abstract = {Chloroplasts originated from the endosymbiosis of ancestral cyanobacteria and maintain transcription and translation machineries for around 100 proteins. Most endosymbiont genes, however, have been transferred to the host nucleus, and the majority of the chloroplast proteome is composed of nucleus-encoded proteins that are biosynthesized in the cytosol and then imported into chloroplasts. How chloroplasts and the nucleus communicate to control the plastid proteome remains an important question. Protein-degrading machineries play key roles in chloroplast proteome biogenesis, remodeling, and maintenance. Research in the past few decades has revealed more than 20 chloroplast proteases, which are localized to specific suborganellar locations. In particular, two energy-dependent processive proteases of bacterial origin, Clp and FtsH, are central to protein homeostasis. Processing endopeptidases such as stromal processing peptidase and thylakoidal processing peptidase are involved in the maturation of precursor proteins imported into chloroplasts by cleaving off the amino-terminal transit peptides. Presequence peptidases and organellar oligopeptidase subsequently degrade the cleaved targeting peptides. Recent findings have indicated that not only intraplastidic but also extraplastidic processive protein-degrading systems participate in the regulation and quality control of protein translocation across the envelopes. In this review, we summarize current knowledge of the major chloroplast proteases in terms of type, suborganellar localization, and diversification. We present details of these degradation processes as case studies according to suborganellar compartment (envelope, stroma, and thylakoids). Key questions and future directions in this field are discussed.}, }
@article {pmid27283855, year = {2016}, author = {Kosoy, M and Bai, Y and Enscore, R and Rizzo, MR and Bender, S and Popov, V and Albayrak, L and Fofanov, Y and Chomel, B}, title = {Bartonella melophagi in blood of domestic sheep (Ovis aries) and sheep keds (Melophagus ovinus) from the southwestern US: Cultures, genetic characterization, and ecological connections.}, journal = {Veterinary microbiology}, volume = {190}, number = {}, pages = {43-49}, doi = {10.1016/j.vetmic.2016.05.009}, pmid = {27283855}, issn = {1873-2542}, mesh = {Animals ; Bartonella/*classification/genetics/isolation &amp; purification/*physiology ; Bartonella Infections/microbiology/transmission/*veterinary ; Blood/*microbiology ; Diptera/*microbiology ; Disease Reservoirs/microbiology/*veterinary ; Genes, Bacterial/genetics ; Genetic Markers/genetics ; Genome, Bacterial/genetics ; Insect Vectors/microbiology ; Phylogeny ; Sheep ; Sheep Diseases/*microbiology/transmission ; Southwestern United States ; Species Specificity ; }, abstract = {Bartonella melophagi sp. nov. was isolated from domestic sheep blood and from sheep keds (Melophagus ovinus) from the southwestern United States. The sequence analyses of the reference strain performed by six molecular markers consistently demonstrated that B. melophagi relates to but differ from other Bartonella species isolated from domestic and wild ruminants. Presence of 183 genes specific for B. melophagi, being absent in genomes of other Bartonella species associated with ruminants also supports the separation of this bacterial species from species of other ruminants. Bartonella DNA was detected in all investigated sheep keds; however, culturing of these bacteria from sheep blood rejects a speculation that B. melophagi is an obligatory endosymbiont. Instead, the results support the hypothesis that the domestic sheep is a natural host reservoir for B. melophagi and the sheep ked its main vector. This bacterium was not isolated from the blood of bighorn sheep and domestic goats belonging to the same subfamily Caprinae. B. melophagi has also been shown to be zoonotic and needs to be investigated further.}, }
@article {pmid27282315, year = {2016}, author = {Sanders, D and Kehoe, R and van Veen, FF and McLean, A and Godfray, HC and Dicke, M and Gols, R and Frago, E}, title = {Defensive insect symbiont leads to cascading extinctions and community collapse.}, journal = {Ecology letters}, volume = {19}, number = {7}, pages = {789-799}, pmid = {27282315}, issn = {1461-0248}, mesh = {Animals ; Aphids/*microbiology ; *Ecosystem ; Enterobacteriaceae ; *Extinction, Biological ; Population Dynamics ; *Symbiosis ; *Wasps ; }, abstract = {Animals often engage in mutualistic associations with microorganisms that protect them from predation, parasitism or pathogen infection. Studies of these interactions in insects have mostly focussed on the direct effects of symbiont infection on natural enemies without studying community-wide effects. Here, we explore the effect of a defensive symbiont on population dynamics and species extinctions in an experimental community composed of three aphid species and their associated specialist parasitoids. We found that introducing a bacterial symbiont with a protective (but not a non-protective) phenotype into one aphid species led to it being able to escape from its natural enemy and increase in density. This changed the relative density of the three aphid species which resulted in the extinction of the two other parasitoid species. Our results show that defensive symbionts can cause extinction cascades in experimental communities and so may play a significant role in the stability of consumer-herbivore communities in the field.}, }
@article {pmid27279628, year = {2016}, author = {Yañez, O and Gauthier, L and Chantawannakul, P and Neumann, P}, title = {Endosymbiotic bacteria in honey bees: Arsenophonus spp. are not transmitted transovarially.}, journal = {FEMS microbiology letters}, volume = {363}, number = {14}, pages = {}, pmid = {27279628}, issn = {1574-6968}, mesh = {Animal Diseases/microbiology/transmission ; Animals ; *Bacteria/classification/genetics ; Bees/*microbiology ; Enterobacteriaceae/classification/genetics ; Phylogeny ; RNA, Bacterial ; RNA, Ribosomal, 16S ; *Symbiosis ; }, abstract = {Intracellular endosymbiotic bacteria are common and can play a crucial role for insect pathology. Therefore, such bacteria could be a potential key to our understanding of major losses of Western honey bees (Apis mellifera) colonies. However, the transmission and potential effects of endosymbiotic bacteria in A. mellifera and other Apis spp. are poorly understood. Here, we explore the prevalence and transmission of the genera Arsenophonus, Wolbachia, Spiroplasma and Rickettsia in Apis spp. Colonies of A. mellifera (N = 33, with 20 eggs from worker brood cells and 100 adult workers each) as well as mated honey bee queens of A. cerana, A. dorsata and A. florea (N = 12 each) were screened using PCR. While Wolbachia, Spiroplasma and Rickettsia were not detected, Arsenophonus spp. were found in 24.2% of A. mellifera colonies and respective queens as well as in queens of A. dorsata (8.3%) and A. florea (8.3%), but not in A. cerana The absence of Arsenophonus spp. from reproductive organs of A. mellifera queens and surface-sterilized eggs does not support transovarial vertical transmission. Instead, horizontal transmission is most likely.}, }
@article {pmid27279553, year = {2016}, author = {DE Pinho Mixão, V and Mendes, AM and Maurício, IL and Calado, MM and Novo, MT and Belo, S and Almeida, AP}, title = {Molecular detection of Wolbachia pipientis in natural populations of mosquito vectors of Dirofilaria immitis from continental Portugal: first detection in Culex theileri.}, journal = {Medical and veterinary entomology}, volume = {30}, number = {3}, pages = {301-309}, doi = {10.1111/mve.12179}, pmid = {27279553}, issn = {1365-2915}, mesh = {Animals ; Culex/*microbiology/parasitology ; DNA, Bacterial/*genetics ; Dirofilaria immitis/isolation &amp; purification ; Dirofilariasis/parasitology/transmission ; Haplotypes ; Mosquito Vectors/*microbiology/parasitology ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Portugal ; RNA, Ribosomal, 16S/*genetics ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia pipientis (Rickettsiales: Rickettsiaceae) protects mosquitoes from infections with arboviruses and parasites. However, the effect of its co-infection on vector competence for Dirofilaria immitis (Spirurida: Onchocercidae) in the wild has not been investigated. This study aimed to screen vectors of D. immitis for wPip, to characterize these, and to investigate a possible association between the occurrence of W. pipientis and that of the nematode. The presence of W. pipientis was assessed in the five mosquito potential vectors of D. immitis in Portugal. Polymerase chain reaction (PCR) products were sequenced, and wPip haplotypes were determined by PCR-restricted fragment length polymorphism (RFLP). Results showed that wPip was detected in 61.5% of Culex pipiens (Diptera: Culicidae) pools and 6.3% of Culex theileri pools. wPip 16s rRNA sequences found in Cx. theileri exactly match those from Cx. pipiens, confirming a mosquito origin, rather than a nematode origin, as some specimens were infected with D. immitis. Only wPip haplotype I was found. No association was found between the presence of wPip and D. immitis in mosquitoes and hence a role for this endosymbiont in influencing vectorial competence is yet to be identified. This study contributes to understanding of wPip distribution in mosquito populations and, to the best of the authors' knowledge, is the first report of natural infections by wPip in Cx. theileri.}, }
@article {pmid27273750, year = {2016}, author = {Zhu, DT and Xia, WQ and Rao, Q and Liu, SS and Ghanim, M and Wang, XW}, title = {Sequencing and comparison of the Rickettsia genomes from the whitefly Bemisia tabaci Middle East Asia Minor I.}, journal = {Insect science}, volume = {23}, number = {4}, pages = {531-542}, doi = {10.1111/1744-7917.12367}, pmid = {27273750}, issn = {1744-7917}, mesh = {Animals ; China ; DNA, Bacterial/genetics ; *Genome, Bacterial ; Hemiptera/*microbiology ; Israel ; Phylogeny ; Rickettsia/*genetics ; Species Specificity ; Symbiosis ; Virulence/genetics ; }, abstract = {The whitefly, Bemisia tabaci, harbors the primary symbiont 'Candidatus Portiera aleyrodidarum' and a variety of secondary symbionts. Among these secondary symbionts, Rickettsia is the only one that can be detected both inside and outside the bacteriomes. Infection with Rickettsia has been reported to influence several aspects of the whitefly biology, such as fitness, sex ratio, virus transmission and resistance to pesticides. However, mechanisms underlying these differences remain unclear, largely due to the lack of genomic information of Rickettsia. In this study, we sequenced the genome of two Rickettsia strains isolated from the Middle East Asia Minor 1 (MEAM1) species of the B. tabaci complex in China and Israel. Both Rickettsia genomes were of high coding density and AT-rich, containing more than 1000 coding sequences, much larger than that of the coexisted primary symbiont, Portiera. Moreover, the two Rickettsia strains isolated from China and Israel shared most of the genes with 100% identity and only nine genes showed sequence differences. The phylogenetic analysis using orthologs shared in the genus, inferred the proximity of Rickettsia in MEAM1 and Rickettsia bellii. Functional analysis revealed that Rickettsia was unable to synthesize amino acids required for complementing the whitefly nutrition. Besides, a type IV secretion system and a number of virulence-related genes were detected in the Rickettsia genome. The presence of virulence-related genes might benefit the symbiotic life of the bacteria, and hint on potential effects of Rickettsia on whiteflies. The genome sequences of Rickettsia provided a basis for further understanding the function of Rickettsia in whiteflies.}, }
@article {pmid27270667, year = {2016}, author = {Perotti, MA and Young, DK and Braig, HR}, title = {The ghost sex-life of the paedogenetic beetle Micromalthus debilis.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {27364}, pmid = {27270667}, issn = {2045-2322}, support = {BB/N001443/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Coleoptera/*physiology/*radiation effects ; *Hot Temperature ; Parthenogenesis/radiation effects ; Rickettsia/growth &amp; development ; Wolbachia/growth &amp; development ; }, abstract = {Genetic and sexual systems can be evolutionarily dynamic within and among clades. However, identifying the processes responsible for switches between, for instance, sexual and asexual reproduction, or cyclic and non-cyclic life histories remains challenging. When animals evolve parthenogenetic reproduction, information about the sexual mating system becomes lost. Here we report an extraordinary case where we have been able to resurrect sexual adults in a species of beetle that reproduces by parthenogenetic paedogenesis, without the production of adults. Via heat treatment, we were able to artificially induce adult beetles of Micromalthus debilis in order to describe its pre-paedogenetic mating system. Adults showed a highly female biased sex ratio, out-breeding behaviour, and sex-role reversal. Paedogenetic larvae of Micromalthus are infected with the endosymbiotic bacteria Rickettsia and Wolbachia. Clear signs of vestigialization in adults are concurrent with the loss of adults. Our data suggest an ancient female sex ratio bias that predates the loss of adults, perhaps associated with endosymbionts. We propose a model for the transition from a haplodiploid cyclical parthenogenetic life history to parthenogenetic paedogenesis. Paedogenetic development induces a new mechanism of sex ratio bias in midges, wasps and beetles.}, }
@article {pmid27267617, year = {2016}, author = {McCutcheon, JP}, title = {From microbiology to cell biology: when an intracellular bacterium becomes part of its host cell.}, journal = {Current opinion in cell biology}, volume = {41}, number = {}, pages = {132-136}, pmid = {27267617}, issn = {1879-0410}, support = {NNA17BB05A//Intramural NASA/United States ; }, mesh = {Animals ; Bacteria/*metabolism ; Biological Evolution ; Eukaryotic Cells/*microbiology ; Intracellular Space/*microbiology ; Organelles/microbiology ; Symbiosis ; }, abstract = {Mitochondria and chloroplasts are now called organelles, but they used to be bacteria. As they transitioned from endosymbionts to organelles, they became more and more integrated into the biochemistry and cell biology of their hosts. Work over the last 15 years has shown that other symbioses show striking similarities to mitochondria and chloroplasts. In particular, many sap-feeding insects house intracellular bacteria that have genomes that overlap mitochondria and chloroplasts in terms of size and coding capacity. The massive levels of gene loss in some of these bacteria suggest that they, too, are becoming highly integrated with their host cells. Understanding these bacteria will require inspiration from eukaryotic cell biology, because a traditional microbiological framework is insufficient for understanding how they work.}, }
@article {pmid27264636, year = {2016}, author = {Mahmoudi, M and Tachibana, A and Goldstone, AB and Woo, YJ and Chakraborty, P and Lee, KR and Foote, CS and Piecewicz, S and Barrozo, JC and Wakeel, A and Rice, BW and Bell Iii, CB and Yang, PC}, title = {Novel MRI Contrast Agent from Magnetotactic Bacteria Enables In Vivo Tracking of iPSC-derived Cardiomyocytes.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {26960}, pmid = {27264636}, issn = {2045-2322}, support = {K24 HL130553/HL/NHLBI NIH HHS/United States ; R43 EB019239/EB/NIBIB NIH HHS/United States ; T32 HL098049/HL/NHLBI NIH HHS/United States ; UM1 HL113456/HL/NHLBI NIH HHS/United States ; R01 EB019458/EB/NIBIB NIH HHS/United States ; }, mesh = {Animals ; Bacteria ; Cell Tracking ; Contrast Media/*administration &amp; dosage ; Heart/*diagnostic imaging ; Humans ; Induced Pluripotent Stem Cells/physiology ; Magnetite Nanoparticles/*administration &amp; dosage ; Male ; Mice, SCID ; Myocardium/pathology ; Myocytes, Cardiac/*physiology/transplantation ; Rats ; Symbiosis ; }, abstract = {Therapeutic delivery of human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMs) represents a novel clinical approach to regenerate the injured myocardium. However, methods for robust and accurate in vivo monitoring of the iCMs are still lacking. Although superparamagnetic iron oxide nanoparticles (SPIOs) are recognized as a promising tool for in vivo tracking of stem cells using magnetic resonance imaging (MRI), their signal persists in the heart even weeks after the disappearance of the injected cells. This limitation highlights the inability of SPIOs to distinguish stem cell viability. In order to overcome this shortcoming, we demonstrate the use of a living contrast agent, magneto-endosymbionts (MEs) derived from magnetotactic bacteria for the labeling of iCMs. The ME-labeled iCMs were injected into the infarcted area of murine heart and probed by MRI and bioluminescence imaging (BLI). Our findings demonstrate that the MEs are robust and effective biological contrast agents to track iCMs in an in vivo murine model. We show that the MEs clear within one week of cell death whereas the SPIOs remain over 2 weeks after cell death. These findings will accelerate the clinical translation of in vivo MRI monitoring of transplanted stem cell at high spatial resolution and sensitivity.}, }
@article {pmid27244963, year = {2016}, author = {Rakthong, P and Ruang-Areerate, T and Baimai, V and Trinachartvanit, W and Ahantarig, A}, title = {FRANCISELLA-LIKE ENDOSYMBIONT IN A TICK COLLECTED FROM A CHICKEN IN SOUTHERN THAILAND.}, journal = {The Southeast Asian journal of tropical medicine and public health}, volume = {47}, number = {2}, pages = {245-249}, pmid = {27244963}, issn = {0125-1562}, mesh = {Animals ; Chickens/*parasitology ; DNA, Ribosomal/genetics ; Francisella/*isolation &amp; purification ; Humans ; Ixodidae/genetics/*microbiology ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; Thailand ; }, abstract = {Francisella is a genus of bacterial pathogens potentially lethal to humans. We report here for the first time a novel Francisella-like endosymbiont discovered in a hard-tick (Rhipicephalus sanguineus s.l.) obtained from a chicken (Gallus domesticus) in Thailand. The phylogenetic results indicate the 16S rDNA sequences of this Francisella bacterium form a unique clade with the Francisella-like endosymbiont of the tick species, Amblyomma varanense and Amblyomma helvolum, that have previously been found on snakes in Thailand. This species of Francisella is in a different group from the other Francisella-like endosymbionts previously reported from other countries. No Francisella was detected in Haemaphysalis wellingtoni ticks obtained from chickens in this study.}, }
@article {pmid27244561, year = {2016}, author = {Lee, SH and Kim, KT and Kwon, OD and Ock, Y and Kim, T and Choi, D and Kwak, D}, title = {Novel Detection of Coxiella spp., Theileria luwenshuni, and T. ovis Endosymbionts in Deer Keds (Lipoptena fortisetosa).}, journal = {PloS one}, volume = {11}, number = {5}, pages = {e0156727}, pmid = {27244561}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; Coxiella/classification/*isolation &amp; purification ; DNA, Bacterial/genetics ; DNA, Protozoan/genetics ; Deer ; Diptera/*microbiology/*parasitology ; Gram-Negative Bacterial Infections/microbiology/*transmission/*veterinary ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Theileria/classification/genetics/*isolation &amp; purification ; Theileriasis/parasitology/*transmission ; }, abstract = {We describe for the first time the detection of Coxiella-like bacteria (CLB), Theileria luwenshuni, and T. ovis endosymbionts in blood-sucking deer keds. Eight deer keds attached to a Korean water deer were identified as Lipoptena fortisetosa (Diptera: Hippoboscidae) by morphological and genetic analyses. Among the endosymbionts assessed, CLB, Theileria luwenshuni, and T. ovis were identified in L. fortisetosa by PCR and nucleotide sequencing. Based on phylogeny, CLB 16S rRNA sequences were classified into clade B, sharing 99.4% identity with CLB from Haemaphysalis longicornis in South Korea. Although the virulence of CLB to vertebrates is still controversial, several studies have reported clinical symptoms in birds due to CLB infections. The 18S rRNA sequences of T. luwenshuni and T. ovis in this study were 98.8-100% identical to those in GenBank, and all of the obtained sequences of T. ovis and T. luwenshuni in this study were 100% identical to each other, respectively. Although further studies are required to positively confirm L. fortisetosa as a biological vector of these pathogens, strong genetic relationships among sequences from this and previous studies suggest potential transmission among mammalian hosts by ticks and keds.}, }
@article {pmid27243367, year = {2016}, author = {Shaw, WR and Marcenac, P and Childs, LM and Buckee, CO and Baldini, F and Sawadogo, SP and Dabiré, RK and Diabaté, A and Catteruccia, F}, title = {Wolbachia infections in natural Anopheles populations affect egg laying and negatively correlate with Plasmodium development.}, journal = {Nature communications}, volume = {7}, number = {}, pages = {11772}, pmid = {27243367}, issn = {2041-1723}, support = {R21 AI117313/AI/NIAID NIH HHS/United States ; U54 GM088558/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Anopheles/microbiology/parasitology/*physiology ; Burkina Faso/epidemiology ; DNA, Bacterial/isolation &amp; purification ; Disease Transmission, Infectious/prevention &amp; control ; Female ; Host-Pathogen Interactions ; Larva/growth &amp; development ; Malaria/epidemiology/*transmission ; Male ; Maternal Inheritance ; Models, Biological ; Mosquito Vectors/microbiology/parasitology/*physiology ; Oviposition/*physiology ; Plasmodium/*growth &amp; development/pathogenicity ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Symbiosis/physiology ; Wolbachia/isolation &amp; purification/*physiology ; }, abstract = {The maternally inherited alpha-proteobacterium Wolbachia has been proposed as a tool to block transmission of devastating mosquito-borne infectious diseases like dengue and malaria. Here we study the reproductive manipulations induced by a recently identified Wolbachia strain that stably infects natural mosquito populations of a major malaria vector, Anopheles coluzzii, in Burkina Faso. We determine that these infections significantly accelerate egg laying but do not induce cytoplasmic incompatibility or sex-ratio distortion, two parasitic reproductive phenotypes that facilitate the spread of other Wolbachia strains within insect hosts. Analysis of 221 blood-fed A. coluzzii females collected from houses shows a negative correlation between the presence of Plasmodium parasites and Wolbachia infection. A mathematical model incorporating these results predicts that infection with these endosymbionts may reduce malaria prevalence in human populations. These data suggest that Wolbachia may be an important player in malaria transmission dynamics in Sub-Saharan Africa.}, }
@article {pmid27242732, year = {2016}, author = {Bukovská, P and Gryndler, M and Gryndlerová, H and Püschel, D and Jansa, J}, title = {Organic Nitrogen-Driven Stimulation of Arbuscular Mycorrhizal Fungal Hyphae Correlates with Abundance of Ammonia Oxidizers.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {711}, pmid = {27242732}, issn = {1664-302X}, abstract = {Large fraction of mineral nutrients in natural soil environments is recycled from complex and heterogeneously distributed organic sources. These sources are explored by both roots and associated mycorrhizal fungi. However, the mechanisms behind the responses of arbuscular mycorrhizal (AM) hyphal networks to soil organic patches of different qualities remain little understood. Therefore, we conducted a multiple-choice experiment examining hyphal responses to different soil patches within the root-free zone by two AM fungal species (Rhizophagus irregularis and Claroideoglomus claroideum) associated with Medicago truncatula, a legume forming nitrogen-fixing root nodules. Hyphal colonization of the patches was assessed microscopically and by quantitative real-time PCR (qPCR) using AM taxon-specific markers, and the prokaryotic and fungal communities in the patches (pooled per organic amendment treatment) were profiled by 454-amplicon sequencing. Specific qPCR markers were then designed and used to quantify the abundance of prokaryotic taxa showing the strongest correlation with the pattern of AM hyphal proliferation in the organic patches as per the 454-sequencing. The hyphal density of both AM fungi increased due to nitrogen (N)-containing organic amendments (i.e., chitin, DNA, albumin, and clover biomass), while no responses as compared to the non-amended soil patch were recorded for cellulose, phytate, or inorganic phosphate amendments. Abundances of several prokaryotes, including Nitrosospira sp. (an ammonium oxidizer) and an unknown prokaryote with affiliation to Acanthamoeba endosymbiont, which were frequently recorded in the 454-sequencing profiles, correlated positively with the hyphal responses of R. irregularis to the soil amendments. Strong correlation between abundance of these two prokaryotes and the hyphal responses to organic soil amendments by both AM fungi was then confirmed by qPCR analyses using all individual replicate patch samples. Further research is warranted to ascertain the causality of these correlations and particularly which direct roles (if any) do these prokaryotes play in the observed AM hyphal responses to organic N amendment, organic N utilization by the AM fungus and its (N-unlimited) host plant. Further, possible trophic dependencies between the different players in the AM hyphosphere needs to be elucidated upon decomposing the organic N sources.}, }
@article {pmid27240350, year = {2016}, author = {Lardi, M and Murset, V and Fischer, HM and Mesa, S and Ahrens, CH and Zamboni, N and Pessi, G}, title = {Metabolomic Profiling of Bradyrhizobium diazoefficiens-Induced Root Nodules Reveals Both Host Plant-Specific and Developmental Signatures.}, journal = {International journal of molecular sciences}, volume = {17}, number = {6}, pages = {}, pmid = {27240350}, issn = {1422-0067}, mesh = {Bacterial Proteins/*genetics ; Bradyrhizobium/*genetics/pathogenicity ; Host Specificity ; Host-Pathogen Interactions ; Mass Spectrometry ; Metabolomics/*methods ; Mutation ; Nitrogen Fixation ; Principal Component Analysis ; Root Nodules, Plant/chemistry/*growth &amp; development/microbiology ; Soybeans/chemistry/growth &amp; development/*microbiology ; Symbiosis ; Vigna/chemistry/growth &amp; development/microbiology ; }, abstract = {Bradyrhizobium diazoefficiens is a nitrogen-fixing endosymbiont, which can grow inside root-nodule cells of the agriculturally important soybean and other host plants. Our previous studies described B. diazoefficiens host-specific global expression changes occurring during legume infection at the transcript and protein level. In order to further characterize nodule metabolism, we here determine by flow injection-time-of-flight mass spectrometry analysis the metabolome of (i) nodules and roots from four different B. diazoefficiens host plants; (ii) soybean nodules harvested at different time points during nodule development; and (iii) soybean nodules infected by two strains mutated in key genes for nitrogen fixation, respectively. Ribose (soybean), tartaric acid (mungbean), hydroxybutanoyloxybutanoate (siratro) and catechol (cowpea) were among the metabolites found to be specifically elevated in one of the respective host plants. While the level of C4-dicarboxylic acids decreased during soybean nodule development, we observed an accumulation of trehalose-phosphate at 21 days post infection (dpi). Moreover, nodules from non-nitrogen-fixing bacteroids (nifA and nifH mutants) showed specific metabolic alterations; these were also supported by independent transcriptomics data. The alterations included signs of nitrogen limitation in both mutants, and an increased level of a phytoalexin in nodules induced by the nifA mutant, suggesting that the tissue of these nodules exhibits defense and stress reactions.}, }
@article {pmid27237947, year = {2016}, author = {Gerth, M}, title = {Classification of Wolbachia (Alphaproteobacteria, Rickettsiales): No evidence for a distinct supergroup in cave spiders.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {43}, number = {}, pages = {378-380}, doi = {10.1016/j.meegid.2016.05.034}, pmid = {27237947}, issn = {1567-7257}, mesh = {Animals ; Caves/*microbiology ; Genes, Bacterial ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Spiders/*microbiology ; Wolbachia/*classification/genetics/isolation &amp; purification ; }, }
@article {pmid27235430, year = {2016}, author = {Tai, V and Carpenter, KJ and Weber, PK and Nalepa, CA and Perlman, SJ and Keeling, PJ}, title = {Genome Evolution and Nitrogen Fixation in Bacterial Ectosymbionts of a Protist Inhabiting Wood-Feeding Cockroaches.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {15}, pages = {4682-4695}, pmid = {27235430}, issn = {1098-5336}, mesh = {Animals ; Bacteroidetes/classification/genetics/isolation &amp; purification/*physiology ; Cockroaches/*parasitology/physiology ; *Evolution, Molecular ; Feeding Behavior ; *Genome, Bacterial ; *Nitrogen Fixation ; Parabasalidea/*microbiology/physiology ; Phylogeny ; *Symbiosis ; Wood/metabolism/parasitology ; }, abstract = {UNLABELLED: By combining genomics and isotope imaging analysis using high-resolution secondary ion mass spectrometry (NanoSIMS), we examined the function and evolution of Bacteroidales ectosymbionts of the protist Barbulanympha from the hindguts of the wood-eating cockroach Cryptocercus punctulatus In particular, we investigated the structure of ectosymbiont genomes, which, in contrast to those of endosymbionts, has been little studied to date, and tested the hypothesis that these ectosymbionts fix nitrogen. Unlike with most obligate endosymbionts, genome reduction has not played a major role in the evolution of the Barbulanympha ectosymbionts. Instead, interaction with the external environment has remained important for this symbiont as genes for synthesis of transporters, outer membrane proteins, lipopolysaccharides, and lipoproteins have been retained. The ectosymbiont genome carried two complete operons for nitrogen fixation, a urea transporter, and a urease, indicating the availability of nitrogen as a driving force behind the symbiosis. NanoSIMS analysis of C. punctulatus hindgut symbionts exposed in vivo to (15)N2 supports the hypothesis that Barbulanympha ectosymbionts are capable of nitrogen fixation. This genomic and in vivo functional investigation of protist ectosymbionts highlights the diversity of evolutionary forces and trajectories that shape symbiotic interactions.<br><br>IMPORTANCE: The ecological and evolutionary importance of symbioses is increasingly clear, but the overall diversity of symbiotic interactions remains poorly explored. In this study, we investigated the evolution and nitrogen fixation capabilities of ectosymbionts attached to the protist Barbulanympha from the hindgut of the wood-eating cockroach Cryptocercus punctulatus In addressing genome evolution of protist ectosymbionts, our data suggest that the ecological pressures influencing the evolution of extracellular symbionts clearly differ from intracellular symbionts and organelles. Using NanoSIMS analysis, we also obtained direct imaging evidence of a specific hindgut microbe playing a role in nitrogen fixation. These results demonstrate the power of combining NanoSIMS and genomics tools for investigating the biology of uncultivable microbes. This investigation paves the way for a more precise understanding of microbial interactions in the hindguts of wood-eating insects and further exploration of the diversity and ecological significance of symbiosis between microbes.}, }
@article {pmid27231663, year = {2016}, author = {Ayayee, PA and Larsen, T and Sabree, Z}, title = {Symbiotic essential amino acids provisioning in the American cockroach, Periplaneta americana (Linnaeus) under various dietary conditions.}, journal = {PeerJ}, volume = {4}, number = {}, pages = {e2046}, pmid = {27231663}, issn = {2167-8359}, abstract = {Insect gut microbes have been shown to provide nutrients such as essential amino acids (EAAs) to their hosts. How this symbiotic nutrient provisioning tracks with the host's demand is not well understood. In this study, we investigated microbial essential amino acid (EAA) provisioning in omnivorous American cockroaches (Periplaneta americana), fed low-quality (LQD) and comparatively higher-quality dog food (DF) diets using carbon stable isotope ratios of EAAs (δ (13)CEAA). We assessed non-dietary EAA input, quantified as isotopic offsets (Δ(13)C) between cockroach (δ (13)CCockroach EAA) and dietary (δ (13)CDietary EAA) EAAs, and subsequently determined biosynthetic origins of non-dietary EAAs in cockroaches using (13)C-fingerprinting with dietary and representative bacterial and fungal δ (13)CEAA. Investigation of biosynthetic origins of de novo non-dietary EAAs indicated bacterial origins of EAA in cockroach appendage samples, and a mixture of fungal and bacterial EAA origins in gut filtrate samples for both LQD and DF-fed groups. We attribute the bacteria-derived EAAs in cockroach appendages to provisioning by the fat body residing obligate endosymbiont, Blattabacterium and gut-residing bacteria. The mixed signatures of gut filtrate samples are attributed to the presence of unassimilated dietary, as well as gut microbial (bacterial and fungal) EAAs. This study highlights the potential impacts of dietary quality on symbiotic EAA provisioning and the need for further studies investigating the interplay between host EAA demands, host dietary quality and symbiotic EAA provisioning in response to dietary sufficiency or deficiency.}, }
@article {pmid27230747, year = {2016}, author = {Maistrenko, OM and Serga, SV and Vaiserman, AM and Kozeretska, IA}, title = {Longevity-modulating effects of symbiosis: insights from Drosophila-Wolbachia interaction.}, journal = {Biogerontology}, volume = {17}, number = {5-6}, pages = {785-803}, doi = {10.1007/s10522-016-9653-9}, pmid = {27230747}, issn = {1573-6768}, mesh = {Aging/*physiology ; Animals ; Bacterial Proteins/metabolism ; Drosophila/*microbiology/*physiology ; Drosophila Proteins/metabolism ; Longevity/*physiology ; Models, Biological ; Symbiosis/*physiology ; Wolbachia/*physiology ; }, abstract = {Microbial communities are known to significantly affect various fitness components and survival of their insect hosts, including Drosophila. The composition of symbiotic microbiota has been shown to change with the host's aging. It is unclear whether these changes are caused by the aging process or, vice versa, they affect the host's aging and longevity. Recent findings indicate that fitness and lifespan of Drosophila are affected by endosymbiotic bacteria Wolbachia. These effects, however, are inconsistent and have been reported both to extend and shorten longevity. The main molecular pathways underlying the lifespan-modulating effects of Wolbachia remain unclear, however insulin/insulin-like growth factor, immune deficiency, ecdysteroid synthesis and signaling and c-Jun N-terminal kinase pathways as well as heat shock protein synthesis and autophagy have been proposed to play a role. Here we revise the current evidence that elucidates the impact of Wolbachia endosymbionts on the aging processes in Drosophila.}, }
@article {pmid27215567, year = {2016}, author = {Qiu, H and Cai, G and Luo, J and Bhattacharya, D and Zhang, N}, title = {Extensive horizontal gene transfers between plant pathogenic fungi.}, journal = {BMC biology}, volume = {14}, number = {}, pages = {41}, pmid = {27215567}, issn = {1741-7007}, mesh = {Ascomycota/*genetics ; Colletotrichum/*genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genetic Markers ; *Genome, Fungal ; Host-Pathogen Interactions ; Phylogeny ; Plant Diseases/microbiology ; Plants/*microbiology ; Symbiosis ; }, abstract = {BACKGROUND: Horizontal gene transfer (HGT) plays an important role in the adaptation of lineages to changing environments. The extent of this process in eukaryotes, however, remains controversial. The most well-known and dramatic form of HGT represents intracellular gene transfer from endosymbionts to the host nuclear genome. Such episodes of transfer typically involve hundreds of genes and are thought to be possible only in the case of endosymbiosis.<br><br>RESULTS: Using a conservative phylogenomic approach, we analyzed genomic data from the fungal pathogen Magnaporthiopsis incrustans in the order Magnaporthales and identified two instances of exclusive sharing of HGT-derived gene markers between Magnaporthales and another lineage of plant-pathogenic fungi in the genus Colletotrichum. Surprisingly, inspection of these data demonstrated that HGT is far more widespread than anticipated, with more than 90 genes (including 33 highly supported candidates) being putatively transferred between Magnaporthales and Colletotrichum. These gene transfers are often physically linked in the genome and show more than two-fold functional enrichment in carbohydrate activating enzymes associated with plant cell wall degradation.<br><br>CONCLUSIONS: Our work provides a novel perspective on the scale of HGT between eukaryotes. These results challenge the notion that recognized HGT plays a minor role in the evolution of fungal lineages, and in the case we describe, is likely implicated in the evolution of plant pathogenesis. More generally, we suggest that the expanding database of closely related eukaryotic genomes and the application of novel analytic methods will further underline the significant impact of foreign gene acquisition across the tree of life. Major lifestyle transitions such as those accompanying the origin of extremophily or pathogenesis are expected to be ideal candidates for studying the mode and tempo of HGT.}, }
@article {pmid27199347, year = {2016}, author = {Dirren, S and Posch, T}, title = {Promiscuous and specific bacterial symbiont acquisition in the amoeboid genus Nuclearia (Opisthokonta).}, journal = {FEMS microbiology ecology}, volume = {92}, number = {8}, pages = {}, doi = {10.1093/femsec/fiw105}, pmid = {27199347}, issn = {1574-6941}, mesh = {Amoeba/*physiology ; Animals ; Bacteria/genetics ; Host Specificity ; Lakes ; Phylogeny ; *Symbiosis ; }, abstract = {We isolated 17 strains of the amoeboid genus Nuclearia (Opisthokonta) from five Swiss lakes. Eight of these nucleariid isolates were associated with bacterial endosymbionts and/or ectosymbionts. Amoebae were characterized morphologically and by their 18S rRNA genes. Phylogeny based on molecular data resulted in four established monophyletic branches and two new clusters. A heterogeneous picture emerged by highlighting nucleariids with associated bacteria. Apart from one cluster which consisted of only isolates with and three groups of amoebae without symbionts, we also found mixed clusters. The picture got even more 'blurred' by regarding the phylogeny of symbiotic bacteria. Although seven different bacterial strains could be identified, it seems that we still are only scratching the surface of symbionts' diversity. Furthermore, types of symbioses might be different depending on host species. Strains of Nuclearia thermophila harboured the same endosymbiont even when isolated from different lakes. This pointed to a specific and obligate interaction. However, two isolates of N. delicatula were associated with different endosymbiotic bacteria. Here the symbiont acquisition seemed to be rather promiscuous. This behaviour regarding symbiotic associations is especially remarkable considering the phylogenetic position of these basal opisthokonts.}, }
@article {pmid27198860, year = {2016}, author = {Kawasaki, Y and Schuler, H and Stauffer, C and Lakatos, F and Kajimura, H}, title = {Wolbachia endosymbionts in haplodiploid and diploid scolytine beetles (Coleoptera: Curculionidae: Scolytinae).}, journal = {Environmental microbiology reports}, volume = {8}, number = {5}, pages = {680-688}, doi = {10.1111/1758-2229.12425}, pmid = {27198860}, issn = {1758-2229}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; J 3527/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Haplodiploidy is a sex determination system in which fertilized diploid eggs develop into females and unfertilized haploid eggs develop into males. The evolutionary explanations for this phenomenon include the possibility that haplodiploidy can be reinforced by infection with endosymbiotic bacteria, such as Wolbachia. The subfamily Scolytinae contains species with haplodiploid and diploid sex determination systems. Thus, we studied the association with Wolbachia in 12 diploid and 11 haplodiploid scolytine beetles by analyzing wsp and multilocus sequence typing (MLST) of five loci in this endosymbiont. Wolbachia genotypes were compared with mitochondrial (COI) and nuclear (EF) genotypes in the scolytines. Eight of the 23 scolytine species were infected with Wolbachia, with haplodiploids at significantly higher rates than diploid species. Cloning and sequencing detected multiple infections with up to six Wolbachia strains in individual species. Phylogenetic analyses of wsp and five MLST genes revealed different Wolbachia strains in scolytines. Comparisons between the beetle and Wolbachia phylogenies revealed that closely related beetles were infected with genetically different Wolbachia strains. These results suggest the horizontal transmission of multiple Wolbachia strains between scolytines. We discuss these results in terms of the evolution of different sex determination systems in scolytine beetles.}, }
@article {pmid27196606, year = {2016}, author = {Suzuki, H and Morton, BR}, title = {Codon Adaptation of Plastid Genes.}, journal = {PloS one}, volume = {11}, number = {5}, pages = {e0154306}, pmid = {27196606}, issn = {1932-6203}, mesh = {Adaptation, Physiological ; Alveolata/genetics ; Chlorophyta/genetics ; Chloroplasts/genetics ; Cluster Analysis ; *Codon ; Cryptophyta/genetics ; Embryophyta/genetics ; Genome, Bacterial ; *Genome, Plastid ; Plastids/*genetics ; RNA, Transfer/metabolism ; Reproducibility of Results ; Rhizaria/genetics ; Rhodophyta/genetics ; Stramenopiles/genetics ; Viridiplantae/genetics ; }, abstract = {Codon adaptation is codon usage bias that results from selective pressure to increase the translation efficiency of a gene. Codon adaptation has been studied across a wide range of genomes and some early analyses of plastids have shown evidence for codon adaptation in a limited set of highly expressed plastid genes. Here we study codon usage bias across all fully sequenced plastid genomes which includes representatives of the Rhodophyta, Alveolata, Cryptophyta, Euglenozoa, Glaucocystophyceae, Rhizaria, Stramenopiles and numerous lineages within the Viridiplantae, including Chlorophyta and Embryophyta. We show evidence that codon adaptation occurs in all genomes except for two, Theileria parva and Heicosporidium sp., both of which have highly reduced gene contents and no photosynthesis genes. We also show evidence that selection for codon adaptation increases the representation of the same set of codons, which we refer to as the adaptive codons, across this wide range of taxa, which is probably due to common features descended from the initial endosymbiont. We use various measures to estimate the relative strength of selection in the different lineages and show that it appears to be fairly strong in certain Stramenopiles and Chlorophyta lineages but relatively weak in many members of the Rhodophyta, Euglenozoa and Embryophyta. Given these results we propose that codon adaptation in plastids is widespread and displays the same general features as adaptation in eubacterial genomes.}, }
@article {pmid27194695, year = {2016}, author = {Lecointe, A and Domart-Coulon, I and Paris, A and Meibom, A}, title = {Cell proliferation and migration during early development of a symbiotic scleractinian coral.}, journal = {Proceedings. Biological sciences}, volume = {283}, number = {1831}, pages = {}, pmid = {27194695}, issn = {1471-2954}, mesh = {Animals ; Anthozoa/*physiology ; Cell Movement ; Cell Proliferation ; Dinoflagellida/*physiology ; *Symbiosis ; }, abstract = {In scleractinian reef-building corals, patterns of cell self-renewal, migration and death remain virtually unknown, limiting our understanding of cellular mechanisms underlying initiation of calcification, and ontogenesis of the endosymbiotic dinoflagellate relationship. In this study, we pulse-labelled the coral Stylophora pistillata for 24 h with BrdU at four life stages (planula, early metamorphosis, primary polyp and adult colony) to investigate coral and endosymbiont cell proliferation during development, while simultaneously recording TUNEL-positive (i.e. apoptotic) nuclei. In the primary polyp, the fate of BrdU-labelled cells was tracked during a 3-day chase. The pharynx and gastrodermis were identified as the most proliferative tissues in the developing polyp, and BrdU-labelled cells accumulated in the surface pseudostratified epithelium and the skeletogenic calicodermis during the chase, revealing cell migration to these epithelia. Surprisingly, the lowest cell turnover was recorded in the calicodermis at all stages, despite active, ongoing skeletal deposition. In dinoflagellate symbionts, DNA synthesis was systematically higher than coral host gastrodermis, especially in planula and early metamorphosis. The symbiont to host cell ratio remained constant, however, indicating successive post-mitotic control mechanisms by the host of its dinoflagellate density in early life stages, increasingly shifting to apoptosis in the growing primary polyp.}, }
@article {pmid27193376, year = {2016}, author = {Cenci, U and Moog, D and Curtis, BA and Tanifuji, G and Eme, L and Lukeš, J and Archibald, JM}, title = {Heme pathway evolution in kinetoplastid protists.}, journal = {BMC evolutionary biology}, volume = {16}, number = {1}, pages = {109}, pmid = {27193376}, issn = {1471-2148}, support = {MOP-115141//CIHR/Canada ; }, mesh = {Animals ; Biological Evolution ; Eukaryota/classification/*physiology ; Gene Transfer, Horizontal ; Heme/*metabolism ; Kinetoplastida/classification/*genetics/*physiology ; Phylogeny ; Symbiosis ; }, abstract = {BACKGROUND: Kinetoplastea is a diverse protist lineage composed of several of the most successful parasites on Earth, organisms whose metabolisms have coevolved with those of the organisms they infect. Parasitic kinetoplastids have emerged from free-living, non-pathogenic ancestors on multiple occasions during the evolutionary history of the group. Interestingly, in both parasitic and free-living kinetoplastids, the heme pathway-a core metabolic pathway in a wide range of organisms-is incomplete or entirely absent. Indeed, Kinetoplastea investigated thus far seem to bypass the need for heme biosynthesis by acquiring heme or intermediate metabolites directly from their environment.<br><br>RESULTS: Here we report the existence of a near-complete heme biosynthetic pathway in Perkinsela spp., kinetoplastids that live as obligate endosymbionts inside amoebozoans belonging to the genus Paramoeba/Neoparamoeba. We also use phylogenetic analysis to infer the evolution of the heme pathway in Kinetoplastea.<br><br>CONCLUSION: We show that Perkinsela spp. is a deep-branching kinetoplastid lineage, and that lateral gene transfer has played a role in the evolution of heme biosynthesis in Perkinsela spp. and other Kinetoplastea. We also discuss the significance of the presence of seven of eight heme pathway genes in the Perkinsela genome as it relates to its endosymbiotic relationship with Paramoeba.}, }
@article {pmid27192713, year = {2016}, author = {Blazier, JC and Jansen, RK and Mower, JP and Govindu, M and Zhang, J and Weng, ML and Ruhlman, TA}, title = {Variable presence of the inverted repeat and plastome stability in Erodium.}, journal = {Annals of botany}, volume = {117}, number = {7}, pages = {1209-1220}, pmid = {27192713}, issn = {1095-8290}, mesh = {Base Composition ; Biological Evolution ; Genes, Plant ; Genome, Plant ; Genome, Plastid ; Geraniaceae/*genetics ; Introns ; *Inverted Repeat Sequences ; Phylogeny ; }, abstract = {BACKGROUND AND AIMS: Several unrelated lineages such as plastids, viruses and plasmids, have converged on quadripartite genomes of similar size with large and small single copy regions and a large inverted repeat (IR). Except for Erodium (Geraniaceae), saguaro cactus and some legumes, the plastomes of all photosynthetic angiosperms display this structure. The functional significance of the IR is not understood and Erodium provides a system to examine the role of the IR in the long-term stability of these genomes. We compared the degree of genomic rearrangement in plastomes of Erodium that differ in the presence and absence of the IR.<br><br>METHODS: We sequenced 17 new Erodium plastomes. Using 454, Illumina, PacBio and Sanger sequences, 16 genomes were assembled and categorized along with one incomplete and two previously published Erodium plastomes. We conducted phylogenetic analyses among these species using a dataset of 19 protein-coding genes and determined if significantly higher evolutionary rates had caused the long branch seen previously in phylogenetic reconstructions within the genus. Bioinformatic comparisons were also performed to evaluate plastome evolution across the genus.<br><br>KEY RESULTS: Erodium plastomes fell into four types (Type 1-4) that differ in their substitution rates, short dispersed repeat content and degree of genomic rearrangement, gene and intron content and GC content. Type 4 plastomes had significantly higher rates of synonymous substitutions (dS) for all genes and for 14 of the 19 genes non-synonymous substitutions (dN) were significantly accelerated. We evaluated the evidence for a single IR loss in Erodium and in doing so discovered that Type 4 plastomes contain a novel IR.<br><br>CONCLUSIONS: The presence or absence of the IR does not affect plastome stability in Erodium. Rather, the overall repeat content shows a negative correlation with genome stability, a pattern in agreement with other angiosperm groups and recent findings on genome stability in bacterial endosymbionts.}, }
@article {pmid27190007, year = {2016}, author = {Manzano-Marín, A and Simon, JC and Latorre, A}, title = {Reinventing the Wheel and Making It Round Again: Evolutionary Convergence in Buchnera-Serratia Symbiotic Consortia between the Distantly Related Lachninae Aphids Tuberolachnus salignus and Cinara cedri.}, journal = {Genome biology and evolution}, volume = {8}, number = {5}, pages = {1440-1458}, pmid = {27190007}, issn = {1759-6653}, mesh = {Animals ; Aphids/*genetics/microbiology ; Buchnera/*genetics ; *Evolution, Molecular ; Genome, Bacterial ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Serratia/genetics ; Symbiosis/*genetics ; }, abstract = {Virtually all aphids (Aphididae) harbor Buchnera aphidicola as an obligate endosymbiont to compensate nutritional deficiencies arising from their phloem diet. Many species within the Lachninae subfamily seem to be consistently associated also with Serratia symbiotica We have previously shown that both Cinara (Cinara) cedri and Cinara (Cupressobium) tujafilina (Lachninae: Eulachnini tribe) have indeed established co-obligate associations with both Buchnera and S. symbiotica However, while Buchnera genomes of both Cinara species are similar, genome degradation differs greatly between the two S. symbiotica strains. To gain insight into the essentiality and degree of integration of S. symbiotica within the Lachninae, we sequenced the genome of both Buchnera and S. symbiotica endosymbionts from the distantly related aphid Tuberolachnus salignus (Lachninae: Tuberolachnini tribe). We found a striking level of similarity between the endosymbiotic system of this aphid and that of C. cedri In both aphid hosts, S. symbiotica possesses a highly reduced genome and is found exclusively intracellularly inside bacteriocytes. Interestingly, T. salignus' endosymbionts present the same tryptophan biosynthetic metabolic complementation as C. cedri's, which is not present in C. tujafilina's. Moreover, we corroborate the riboflavin-biosynthetic-role take-over/rescue by S. symbiotica in T. salignus, and therefore, provide further evidence for the previously proposed establishment of a secondary co-obligate endosymbiont in the common ancestor of the Lachninae aphids. Finally, we propose that the putative convergent split of the tryptophan biosynthetic role between Buchnera and S. symbiotica could be behind the establishment of S. symbiotica as an obligate intracellular symbiont and the triggering of further genome degradation.}, }
@article {pmid27189996, year = {2016}, author = {Newton, IL and Clark, ME and Kent, BN and Bordenstein, SR and Qu, J and Richards, S and Kelkar, YD and Werren, JH}, title = {Comparative Genomics of Two Closely Related Wolbachia with Different Reproductive Effects on Hosts.}, journal = {Genome biology and evolution}, volume = {8}, number = {5}, pages = {1526-1542}, pmid = {27189996}, issn = {1759-6653}, support = {R21 HD086833/HD/NICHD NIH HHS/United States ; }, mesh = {Animals ; Arthropods/genetics/microbiology/parasitology ; Cytoplasm/genetics ; Drosophila/*genetics/microbiology/parasitology ; Genome, Bacterial ; Genomics ; Host Specificity/*genetics ; Male ; Mutation ; Phylogeny ; Reproduction/genetics ; Selection, Genetic/*genetics ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Wolbachia pipientis are obligate intracellular bacteria commonly found in many arthropods. They can induce various reproductive alterations in hosts, including cytoplasmic incompatibility, male-killing, feminization, and parthenogenetic development, and can provide host protection against some viruses and other pathogens. Wolbachia differ from many other primary endosymbionts in arthropods because they undergo frequent horizontal transmission between hosts and are well known for an abundance of mobile elements and relatively high recombination rates. Here, we compare the genomes of two closely related Wolbachia (with 0.57% genome-wide synonymous divergence) that differ in their reproductive effects on hosts. wVitA induces a sperm-egg incompatibility (also known as cytoplasmic incompatibility) in the parasitoid insect Nasonia vitripennis, whereas wUni causes parthenogenetic development in a different parasitoid, Muscidifurax uniraptor Although these bacteria are closely related, the genomic comparison reveals rampant rearrangements, protein truncations (particularly in proteins predicted to be secreted), and elevated substitution rates. These changes occur predominantly in the wUni lineage, and may be due in part to adaptations by wUni to a new host environment, or its phenotypic shift to parthenogenesis induction. However, we conclude that the approximately 8-fold elevated synonymous substitution rate in wUni is due to a either an elevated mutation rate or a greater number of generations per year in wUni, which occurs in semitropical host species. We identify a set of genes whose loss or pseudogenization in the wUni lineage implicates them in the phenotypic shift from cytoplasmic incompatibility to parthenogenesis induction. Finally, comparison of these closely related strains allows us to determine the fine-scale mutation patterns in Wolbachia Although Wolbachia are AT rich, mutation probabilities estimated from 4-fold degenerate sites are not AT biased, and predict an equilibrium AT content much less biased than observed (57-50% AT predicted vs. 76% current content at degenerate sites genome wide). The contrast suggests selection for increased AT content within Wolbachia genomes.}, }
@article {pmid27189571, year = {2016}, author = {Mondo, SJ and Salvioli, A and Bonfante, P and Morton, JB and Pawlowska, TE}, title = {Nondegenerative Evolution in Ancient Heritable Bacterial Endosymbionts of Fungi.}, journal = {Molecular biology and evolution}, volume = {33}, number = {9}, pages = {2216-2231}, doi = {10.1093/molbev/msw086}, pmid = {27189571}, issn = {1537-1719}, mesh = {Bacteria/*genetics/metabolism ; *Biological Evolution ; Evolution, Molecular ; Genetic Drift ; Genome ; Glomeromycota/*genetics/metabolism ; Mutation Rate ; Phylogeny ; Selection, Genetic ; Symbiosis ; }, abstract = {Bacterial endosymbionts are critical to the existence of many eukaryotes. Among them, vertically transmitted endobacteria are uniquely typified by reduced genomes and molecular evolution rate acceleration relative to free-living taxa. These patterns are attributable to genetic drift-dominated degenerative processes associated with reproductive dependence on the host. The degenerative evolution scenario is well supported in endobacteria with strict vertical transmission, such as essential mutualists of insects. In contrast, heritable endosymbionts that are nonessential to their hosts and engage occasionally in horizontal transmission are expected to display deviations from the degenerative evolution model. To explore evolution patterns in such nonessential endobacteria, we focused on Candidatus Glomeribacter gigasporarum ancient heritable mutualists of fungi. Using a collection of genomes, we estimated in Glomeribacter mutation rate at 2.03 × 10(-9) substitutions per site per year and effective population size at 1.44 × 10(8) Both fall within the range of values observed in free-living bacteria. To assess the ability of Glomeribacter to purge slightly deleterious mutations, we examined genome-wide dN/dS values and distribution patterns. We found that these dN/dS profiles cluster Glomeribacter with free-living bacteria as well as with other nonessential endosymbionts, while distinguishing it from essential heritable mutualists of insects. Finally, our evolutionary simulations revealed that the molecular evolution rate acceleration in Glomeribacter is caused by limited recombination in a largely clonal population rather than by increased fixation of slightly deleterious mutations. Based on these patterns, we propose that genome evolution in Glomeribacter is nondegenerative and exemplifies a departure from the model of degenerative evolution in heritable endosymbionts.}, }
@article {pmid27189544, year = {2016}, author = {Clayton, AL and Jackson, DG and Weiss, RB and Dale, C}, title = {Adaptation by Deletogenic Replication Slippage in a Nascent Symbiont.}, journal = {Molecular biology and evolution}, volume = {33}, number = {8}, pages = {1957-1966}, pmid = {27189544}, issn = {1537-1719}, support = {R01 AI095736/AI/NIAID NIH HHS/United States ; T32 GM007464/GM/NIGMS NIH HHS/United States ; }, mesh = {Acclimatization/genetics ; Adaptation, Physiological/*genetics ; Bacteria/genetics ; DNA Replication ; DNA, Bacterial/genetics ; Enterobacteriaceae/*genetics ; Evolution, Molecular ; Genome, Bacterial ; INDEL Mutation ; Phenotype ; Phylogeny ; Sequence Analysis, DNA/methods ; Symbiosis/genetics ; }, abstract = {As a consequence of population level constraints in the obligate, host-associated lifestyle, intracellular symbiotic bacteria typically exhibit high rates of molecular sequence evolution and extensive genome degeneration over the course of their host association. While the rationale for genome degeneration is well understood, little is known about the molecular mechanisms driving this change. To understand these mechanisms we compared the genome of Sodalis praecaptivus, a nonhost associated bacterium that is closely related to members of the Sodalis-allied clade of insect endosymbionts, with the very recently derived insect symbiont Candidatus Sodalis pierantonius. The characterization of indel mutations in the genome of Ca Sodalis pierantonius shows that the replication system in this organism is highly prone to deletions resulting from polymerase slippage events in regions encoding G+C-rich repetitive sequences. This slippage-prone phenotype is mechanistically associated with the loss of certain components of the bacterial DNA recombination machinery at an early stage in symbiotic life and is expected to facilitate rapid adaptation to the novel host environment. This is analogous to the emergence of mutator strains in both natural and laboratory populations of bacteria, which tend to reach high frequencies in clonal populations due to linkage between the mutator allele and the resulting adaptive mutations.}, }
@article {pmid27172712, year = {2016}, author = {Zagata, P and Greczek-Stachura, M and Tarcz, S and Rautian, M}, title = {The Evolutionary Relationships between Endosymbiotic Green Algae of Paramecium bursaria Syngens Originating from Different Geographical Locations.}, journal = {Folia biologica}, volume = {64}, number = {1}, pages = {47-54}, doi = {10.3409/fb64_1.47}, pmid = {27172712}, issn = {0015-5497}, mesh = {*Biological Evolution ; Chlorophyta/*genetics/*physiology ; DNA, Plant/genetics ; DNA, Ribosomal/genetics ; Demography ; Gene Expression Regulation, Plant/physiology ; Paramecium/*physiology ; Symbiosis/genetics/*physiology ; }, abstract = {Paramecium bursaria (Ehrenberg 1831), a freshwater ciliate, typically harbors hundreds of green algal symbionts inside the cell. The aim of present study was the molecular identification of newly analyzed P. bursaria symbionts. The second aspect of the present survey was testing a hypothesis whether endosymbionts prefer the specified syngen of the host, and the specified geographical distribution. Ten strains of endosymbionts isolated from strains of P. bursaria originating from different geographical locations were studied. We analyzed for the first time, both the fragment of plastid genome containing 3'rpl36-5' infA genes and a fragment of a nuclear gene encoding large subunit ribosomal RNA (LSU rDNA). The analysis of the LSU rDNA sequences showed the existence of 3 haplotypes and the haplotype diversity of 0.733, and 8 haplotypes for the 3'rpl36-5' infA gene fragment and haplotype diversity of 0.956. The endosymbionts isolated from P. bursaria strains were identified as Chlorella vulgaris, Ch. variabilis and Micractinium conductrix. There was no correlation between the syngen of P. bursaria and the species of endosymbiont.}, }
@article {pmid27160600, year = {2016}, author = {Masson, F and Zaidman-Rémy, A and Heddi, A}, title = {Antimicrobial peptides and cell processes tracking endosymbiont dynamics.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {371}, number = {1695}, pages = {}, pmid = {27160600}, issn = {1471-2970}, mesh = {Animals ; Antimicrobial Cationic Peptides/genetics/metabolism ; Apoptosis ; Autophagy ; *Bacterial Physiological Phenomena ; Insect Proteins/genetics/metabolism ; *Symbiosis ; Weevils/genetics/immunology/*microbiology/*physiology ; }, abstract = {Many insects sustain long-term relationships with intracellular symbiotic bacteria that provide them with essential nutrients. Such endosymbiotic relationships likely emerged from ancestral infections of the host by free-living bacteria, the genomes of which experience drastic gene losses and rearrangements during the host-symbiont coevolution. While it is well documented that endosymbiont genome shrinkage results in the loss of bacterial virulence genes, whether and how the host immune system evolves towards the tolerance and control of bacterial partners remains elusive. Remarkably, many insects rely on a 'compartmentalization strategy' that consists in secluding endosymbionts within specialized host cells, the bacteriocytes, thus preventing direct symbiont contact with the host systemic immune system. In this review, we compile recent advances in the understanding of the bacteriocyte immune and cellular regulators involved in endosymbiont maintenance and control. We focus on the cereal weevils Sitophilus spp., in which bacteriocytes form bacteriome organs that strikingly evolve in structure and number according to insect development and physiological needs. We discuss how weevils track endosymbiont dynamics through at least two mechanisms: (i) a bacteriome local antimicrobial peptide synthesis that regulates endosymbiont cell cytokinesis and helps to maintain a homeostatic state within bacteriocytes and (ii) some cellular processes such as apoptosis and autophagy which adjust endosymbiont load to the host developmental requirements, hence ensuring a fine-tuned integration of symbiosis costs and benefits.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.}, }
@article {pmid27160085, year = {2016}, author = {Maia, C and Altet, L and Serrano, L and Cristóvão, JM and Tabar, MD and Francino, O and Cardoso, L and Campino, L and Roura, X}, title = {Molecular detection of Leishmania infantum, filariae and Wolbachia spp. in dogs from southern Portugal.}, journal = {Parasites &amp; vectors}, volume = {9}, number = {1}, pages = {170}, pmid = {27160085}, issn = {1756-3305}, mesh = {Animals ; Dirofilaria immitis/genetics/isolation &amp; purification ; Dirofilariasis/epidemiology ; Dog Diseases/*epidemiology/microbiology/parasitology ; Dogs ; Female ; Filariasis/epidemiology/parasitology/*veterinary ; Filarioidea/genetics/isolation &amp; purification/microbiology ; Humans ; Leishmania infantum/genetics/*isolation &amp; purification ; Leishmaniasis, Visceral/epidemiology/parasitology/*veterinary ; Male ; Portugal/epidemiology ; Rickettsiaceae Infections/epidemiology/microbiology/*veterinary ; Wolbachia/genetics/*isolation &amp; purification ; Zoonoses ; }, abstract = {BACKGROUND: Leishmaniosis caused by the protozoan Leishmania infantum and dirofilariosis caused by the nematodes Dirofilaria immitis or Dirofilaria repens are vector-borne zoonoses widely present in the Mediterranean basin. In addition, some studies reported that the endosymbiont Wolbachia spp. play a role in the biology and pathogenesis of filarial parasites. The aim of this work was to evaluate the frequency of mono- and co-infections by L. infantum, filariae and Wolbachia spp. and their association with clinical signs in dogs from the south of Portugal. Leishmanial, filarial and Wolbachia spp. DNA were evaluated by specific real-time polymerase chain reaction (qPCR) assays in blood samples from 230 dogs.<br><br>FINDINGS: One hundred and thirty-nine (60.4&#xa0;%) dogs were qPCR-positive for L. infantum and 26 (11.3&#xa0;%) for filariae (24 for D. immitis only, one D. immitis and for Acanthocheilonema dracunculoides and another one for Acanthocheilonema reconditum only). Wolbachia spp.&#xa0;DNA was amplified from 16 (64.0&#xa0;%) out of the 25 D. immitis-positive dogs. Nineteen (8.3&#xa0;%) dogs were co-infected with L. infantum and D. immitis, including the one (0.4&#xa0;%) A. drancunculoides-positive animal. In dogs without clinical signs consistent with leishmaniosis and/or dirofilariosis, L. infantum prevalence was 69&#xa0;%, whereas in those dogs with at least one clinical manifestation compatible with any of the two parasitoses prevalence was 42.7&#xa0;%. Leishmania prevalence was significantly higher in apparently healthy mongrels (77.2&#xa0;%) and pets (76.9&#xa0;%) than in defined-breed dogs (including crosses; 58.8&#xa0;%) and in dogs with an aptitude other than pet (i.e. farm, guard, hunting, shepherd or stray), respectively, whereas in those dogs with at least one clinical sign, the detection of L. infantum DNA was higher in males (53.3&#xa0;%) and in those dogs not receiving insect repellents (52.8&#xa0;%).<br><br>CONCLUSIONS: The molecular detection of canine vector-borne disease (CVBD) agents, some of which are zoonotic, reinforces the need to implement efficient prophylactic measures, such as insect repellents and macrocyclic lactones (including compliance to administration), in the geographical areas where these agents are distributed, with the view to prevent infection and disease among mammalian hosts including humans.}, }
@article {pmid27159727, year = {2017}, author = {Gaikwad, S and Warudkar, A and Shouche, Y}, title = {Efficacy of DNA barcoding for the species identification of spiders from Western Ghats of India.}, journal = {Mitochondrial DNA. Part A, DNA mapping, sequencing, and analysis}, volume = {28}, number = {5}, pages = {638-644}, doi = {10.3109/24701394.2016.1166219}, pmid = {27159727}, issn = {2470-1408}, mesh = {Animals ; DNA Barcoding, Taxonomic/*methods ; Electron Transport Complex IV/genetics ; Genetic Variation ; India ; Phylogeny ; Sequence Analysis, DNA/*methods ; Species Specificity ; Spiders/*classification/enzymology/genetics ; }, abstract = {DNA barcoding has emerged as an additional tool for taxonomy and as an aid to taxonomic impediments. Due to their extensive morphological variation, spiders are taxonomically challenging. Therefore, all over the world, attempts are being made to DNA barcode species of spiders. Till now no attempts were made to DNA barcode Indian spiders despite their rich diversity. We have generated DNA barcodes for 60 species (n = 112) of spiders for the first time from India. Although only 17 species were correctly identified at the species level, DNA barcoding correctly discriminated 99% of the species studied here. We have also found high intraspecies nucleotide divergence in Plexippus paykulli suggesting cryptic diversity that needs to be studied in detail. Our study also showed non-specific amplification of the Cytochrome Oxidase I (COI) gene of endosymbiont bacteria Wolbachia. However, these cases are very rare and could be resolved by the use of modified or group specific primers.}, }
@article {pmid27159401, year = {2016}, author = {, }, title = {Correction: Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways.}, journal = {PLoS pathogens}, volume = {12}, number = {5}, pages = {e1005639}, pmid = {27159401}, issn = {1553-7374}, abstract = {[This corrects the article DOI: 10.1371/journal.ppat.1005536.].}, }
@article {pmid27156023, year = {2016}, author = {Dutra, HL and Rocha, MN and Dias, FB and Mansur, SB and Caragata, EP and Moreira, LA}, title = {Wolbachia Blocks Currently Circulating Zika Virus Isolates in Brazilian Aedes aegypti Mosquitoes.}, journal = {Cell host &amp; microbe}, volume = {19}, number = {6}, pages = {771-774}, pmid = {27156023}, issn = {1934-6069}, mesh = {Aedes/*microbiology/*virology ; Animals ; Antibiosis ; Brazil ; Disease Transmission, Infectious/prevention &amp; control ; Female ; Insect Vectors/microbiology/virology ; Male ; Saliva/microbiology/virology ; Symbiosis ; Wolbachia/*physiology ; Zika Virus/isolation &amp; purification/*physiology ; Zika Virus Infection/microbiology/prevention &amp; control/transmission/virology ; }, abstract = {The recent association of Zika virus with cases of microcephaly has sparked a global health crisis and highlighted the need for mechanisms to combat the Zika vector, Aedes aegypti mosquitoes. Wolbachia pipientis, a bacterial endosymbiont of insect, has recently garnered attention as a mechanism for arbovirus control. Here we report that Aedes aegypti harboring Wolbachia are highly resistant to infection with two currently circulating Zika virus isolates from the recent Brazilian epidemic. Wolbachia-harboring mosquitoes displayed lower viral prevalence and intensity and decreased disseminated infection and, critically, did not carry infectious virus in the saliva, suggesting that viral transmission was blocked. Our data indicate that the use of Wolbachia-harboring mosquitoes could represent an effective mechanism to reduce Zika virus transmission and should be included as part of Zika control strategies.}, }
@article {pmid27154505, year = {2016}, author = {Rao, HC and Rakshith, D and Gurudatt, DM and Satish, S}, title = {Implication of PKS type I gene and chromatographic strategy for the biodiscovery of antimicrobial polyketide metabolites from endosymbiotic Nocardiopsis prasina CLA68.}, journal = {Die Naturwissenschaften}, volume = {103}, number = {5-6}, pages = {45}, pmid = {27154505}, issn = {1432-1904}, mesh = {Actinobacteria/*enzymology/metabolism ; Anti-Infective Agents/analysis/isolation &amp; purification/metabolism ; Bacteria/drug effects ; *Chromatography ; Drug Discovery ; Methicillin-Resistant Staphylococcus aureus/drug effects ; Microbial Sensitivity Tests ; Molecular Sequence Data ; Polyketide Synthases/*genetics ; Polyketides/*isolation &amp; purification/pharmacology ; }, abstract = {Advanced approach in probing for polyketide antimicrobials requires novel genomics and chromatographic strategies. An endophytic strain CLA68 was isolated from the root of Combretum latifolium Blume (Combretaceae) collected from the Western Ghats of Southern India. Strain CLA68 was then identified as Nocardiopsis prasina by its characteristic culture morphology and analysis of 16S rRNA gene sequence. Biosynthetic polyketide synthase genes were investigated using two pairs of degenerate primers. Ethyl acetate extract of CLA68 exhibited broad spectrum activity against a panel of test human pathogens. PKS type-I gene detection and chromatographic strategy yielded a robust polyketide antimicrobial compound which identified as nocapyrone E. Minimum inhibitory concentration of the purified compound against MRSA and other human pathogens ranged between 25 and 100 μg/ml. The present work highlights the utility of N. prasina CLA68 as potential source for antimicrobial polyketide nocapyrone E which could help to combat multidrug-resistant pathogens. This study demonstrates feasibility of PKS type-I gene-based molecular approach and chemical investigation by chromatographic approach is the best method for prediction and rapid discovery of novel polyketides from endosymbiotic actinomycetes. The sequence data of this endosymbiotic actinomycete is deposited in GenBank under the accession no. KP269077.}, }
@article {pmid27154318, year = {2016}, author = {Jouffroy, SJ and Schlueter, AH and Bildfell, RJ and Rockey, DD}, title = {Rhabdochlamydia spp. in an Oregon raptor.}, journal = {Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc}, volume = {28}, number = {4}, pages = {473-476}, doi = {10.1177/1040638716646408}, pmid = {27154318}, issn = {1943-4936}, mesh = {Animals ; Base Sequence ; Bird Diseases/*diagnosis/microbiology ; Chlamydiales/classification/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics ; Gram-Negative Bacterial Infections/diagnosis/microbiology/*veterinary ; *Hawks ; Oregon ; Phylogeny ; Polymerase Chain Reaction/veterinary ; RNA, Ribosomal, 16S/genetics ; }, abstract = {PCR-based approach was used to examine the rate of Chlamydia positivity in raptors from wild bird rehabilitation centers in Oregon. Three of 82 birds were identified as positive for Chlamydia with this PCR. Sequence analysis of 16S ribosomal DNA from 2 of these birds confirmed the presence of DNA from phylum Chlamydiae. One bird was positive for Chlamydia psittaci in both choanal and cloacal swabs. The second bird, a louse-infested red-tailed hawk, had evidence of choanal colonization by "Candidatus Rhabdochlamydia" spp. Our study describes evidence of this Chlamydia-like organism in the United States. This survey also suggests that the carriage rate of C. psittaci is low in raptors in Oregon wild bird rehabilitation centers, and that care must be taken in the design of PCR primers for phylum Chlamydiae such that colonization by insect endosymbionts is not mistaken for an infection by known chlamydial pathogens.}, }
@article {pmid27132518, year = {2016}, author = {Khoo, JJ and Chen, F and Kho, KL and Ahmad Shanizza, AI and Lim, FS and Tan, KK and Chang, LY and AbuBakar, S}, title = {Bacterial community in Haemaphysalis ticks of domesticated animals from the Orang Asli communities in Malaysia.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {5}, pages = {929-937}, doi = {10.1016/j.ttbdis.2016.04.013}, pmid = {27132518}, issn = {1877-9603}, mesh = {Anaplasma/genetics/isolation &amp; purification ; Animals ; *Animals, Domestic ; Bacillus/genetics/isolation &amp; purification ; Bacteria/*isolation &amp; purification ; Cats/parasitology ; Chickens/parasitology ; Coxiella/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Dogs/parasitology ; Ehrlichia/genetics/isolation &amp; purification ; Ixodidae/*microbiology ; Malaysia/epidemiology ; *Microbiota ; Mycobacterium/genetics/isolation &amp; purification ; Phylogeny ; Polymerase Chain Reaction ; Pseudomonas/genetics/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/isolation &amp; purification ; Sphingomonas/genetics/isolation &amp; purification ; Tick Infestations/epidemiology/*veterinary ; }, abstract = {Ticks are vectors in the transmission of many important infectious diseases in human and animals. Ticks can be readily found in the semi-forested areas such as the settlements of the indigenous people in Malaysia, the Orang Asli. There is still minimal information available on the bacterial agents associated with ticks found in Malaysia. We performed a survey of the bacterial communities associated with ticks collected from domestic animals found in two Orang Asli villages in Malaysia. We collected 62 ticks, microscopically and molecularly identified as related to Haemaphysalis wellingtoni, Haemaphysalis hystricis and Haemaphysalis bispinosa. Bacterial 16s rRNA hypervariable region (V6) amplicon libraries prepared from the tick samples were sequenced on the Ion Torrent PGM platform. We detected a total of 392 possible bacterial genera after pooling and sequencing 20 samples, indicating a diverse bacterial community profile. Dominant taxa include the potential tick endosymbiont, Coxiella. Other dominant taxa include the tick-associated pathogen, Rickettsia, and environmental bacteria such as Bacillus, Mycobacterium, Sphingomonas and Pseudomonas. Other known tick-associated bacteria were also detected, including Anaplasma, Ehrlichia, Rickettsiella and Wolbachia, albeit at very low abundance. Specific PCR was performed on selected samples to identify Rickettsia and Coxiella. Sequence of Rickettsia felis, which causes spotted fever in human and cats, was identified in one sample. Coxiella endosymbionts were detected in three samples. This study provides the baseline knowledge of the microbiome of ticks in Malaysia, focusing on tick-associated bacteria affecting the Orang Asli communities. The role of the herein found Coxiella and Rickettsia in tick physiology or disease transmission merits further investigation.}, }
@article {pmid27132173, year = {2016}, author = {He, D and Sierra, R and Pawlowski, J and Baldauf, SL}, title = {Reducing long-branch effects in multi-protein data uncovers a close relationship between Alveolata and Rhizaria.}, journal = {Molecular phylogenetics and evolution}, volume = {101}, number = {}, pages = {1-7}, doi = {10.1016/j.ympev.2016.04.033}, pmid = {27132173}, issn = {1095-9513}, mesh = {Alveolata/*classification/genetics/*metabolism ; *Databases, Protein ; Genomics ; *Phylogeny ; Rhizaria/*classification/genetics/*metabolism ; Selection, Genetic ; }, abstract = {Rhizaria is a major eukaryotic group of tremendous diversity, including amoebae with spectacular skeletons or tests (Radiolaria and Foraminifera), plasmodial parasites (Plasmodiophorida) and secondary endosymbionts (Chlorarachniophyta). Current phylogeny places Rhizaria in an unresolved trichotomy with Stramenopila and Alveolata (supergroup "SAR"). We assembled a 147-protein data set with extensive rhizarian coverage (M147), including the first transcriptomic data for a euglyphid amoeba. Phylogenetic pre-screening of individual proteins indicated potential problems with radically misplaced sequences due either to contamination of rhizarian sequences amplified from wild collected material and/or extremely long branches (xLBs). Therefore, two data subsets were extracted containing either all proteins consistently recovering rhizarian monophyly (M34) or excluding all proteins with ⩾3 xLBs (defined as ⩾2× the average terminal branch length for the tree). Phylogenetic analyses of M147 give conflicting results depending on the outgroup and method of analysis but strongly support an exclusive Rhizaria+Alveolata (R+A) clade with both data subsets (M34 and M37) regardless of phylogenetic method used. Support for an R+A clade is most consistent when a close outgroup is used and decreases with more distant outgroups, suggesting that support for alternative SAR topologies may reflect a long-branch attraction artifact. A survey of xLB distribution among taxa and protein functional category indicates that small "informational" proteins in particular have highly variable evolutionary rates with no consistent pattern among taxa.}, }
@article {pmid27125254, year = {2016}, author = {El-Azaz, J and de la Torre, F and Ávila, C and Cánovas, FM}, title = {Identification of a small protein domain present in all plant lineages that confers high prephenate dehydratase activity.}, journal = {The Plant journal : for cell and molecular biology}, volume = {87}, number = {2}, pages = {215-229}, doi = {10.1111/tpj.13195}, pmid = {27125254}, issn = {1365-313X}, mesh = {Amino Acids, Dicarboxylic/metabolism ; Cyclohexenes/metabolism ; Genes, Plant/physiology ; Metabolic Networks and Pathways/physiology ; Phenylalanine/metabolism ; Phenylpyruvic Acids/metabolism ; Phylogeny ; Pinus/enzymology/*genetics/metabolism ; Plants ; Prephenate Dehydratase/*genetics/metabolism ; Tyrosine/analogs &amp; derivatives/metabolism ; }, abstract = {l-Phenylalanine serves as a building block for the biosynthesis of proteins, but also as a precursor for a wide range of plant-derived compounds essential for plants and animals. Plants can synthesize Phe within the plastids using arogenate as a precursor; however, an alternative pathway using phenylpyruvate as an intermediate, described for most microorganisms, has recently been proposed. The functionality of this pathway requires the existence of enzymes with prephenate dehydratase (PDT) activity (EC 4.2.1.51) in plants. Using phylogenetic studies, functional complementation assays in yeast and biochemical analysis, we have identified the enzymes displaying PDT activity in Pinus pinaster. Through sequence alignment comparisons and site-directed mutagenesis we have identified a 22-amino acid region conferring PDT activity (PAC domain) and a single Ala314 residue critical to trigger this activity. Our results demonstrate that all plant clades include PAC domain-containing ADTs, suggesting that the PDT activity, and thus the ability to synthesize Phe using phenylpyruvate as an intermediate, has been preserved throughout the evolution of plants. Moreover, this pathway together with the arogenate pathway gives plants a broad and versatile capacity to synthesize Phe and its derived compounds. PAC domain-containing enzymes are also present in green and red algae, and glaucophytes, the three emerging clades following the primary endosymbiont event resulting in the acquisition of plastids in eukaryotes. The evolutionary prokaryotic origin of this domain is discussed.}, }
@article {pmid27122555, year = {2016}, author = {Levy, O and Karako-Lampert, S and Waldman Ben-Asher, H and Zoccola, D and Pagès, G and Ferrier-Pagès, C}, title = {Molecular assessment of the effect of light and heterotrophy in the scleractinian coral Stylophora pistillata.}, journal = {Proceedings. Biological sciences}, volume = {283}, number = {1829}, pages = {}, pmid = {27122555}, issn = {1471-2954}, mesh = {Animals ; Anthozoa/genetics/*physiology ; Coral Reefs ; Heterotrophic Processes ; Light ; Oxidative Stress ; Photosynthesis ; Symbiosis ; Transcriptome ; Zooplankton/physiology ; }, abstract = {Corals acquire nutrients via the transfer of photosynthates by their endosymbionts (autotrophy), or via zooplankton predation by the animal (heterotrophy). During stress events, corals lose their endosymbionts, and undergo starvation, unless they increase their heterotrophic capacities. Molecular mechanisms by which heterotrophy sustains metabolism in stressed corals remain elusive. Here for the first time, to the best of our knowledge, we identified specific genes expressed in heterotrophically fed and unfed colonies of the scleractinian coral Stylophora pistillata, maintained under normal and light-stress conditions. Physiological parameters and gene expression profiling demonstrated that fed corals better resisted stress than unfed ones by exhibiting less oxidative damage and protein degradation. Processes affected in light-stressed unfed corals (HLU), were related to energy and metabolite supply, carbohydrate biosynthesis, ion and nutrient transport, oxidative stress, Ca(2+) homeostasis, metabolism and calcification (carbonic anhydrases, calcium-transporting ATPase, bone morphogenetic proteins). Two genes (cp2u1 and cp1a2), which belong to the cytochrome P450 superfamily, were also upregulated 249 and 10 times, respectively, in HLU corals. In contrast, few of these processes were affected in light-stressed fed corals (HLF) because feeding supplied antioxidants and energetic molecules, which help repair oxidative damage. Altogether, these results show that heterotrophy helps prevent the cascade of metabolic problems downstream of oxidative stress.}, }
@article {pmid27122079, year = {2016}, author = {Wallau, GL and da Rosa, MT and De Ré, FC and Loreto, EL}, title = {Wolbachia from Drosophila incompta: just a hitchhiker shared by Drosophila in the New and Old World?.}, journal = {Insect molecular biology}, volume = {25}, number = {4}, pages = {487-499}, doi = {10.1111/imb.12237}, pmid = {27122079}, issn = {1365-2583}, mesh = {Animals ; Brazil ; Drosophila/*microbiology ; *Evolution, Molecular ; *Genome, Bacterial ; Phylogeny ; Wolbachia/*genetics/physiology ; }, abstract = {Wolbachia are intracellular endosymbionts that infect arthropods and filarial nematodes, occasionally causing a wide variety of modifications in host biology, such as male-killing and cytoplasmic incompatibility (CI), amongst others. This study assembled draft genomes for Wolbachia infecting Drosophila incompta, a species that uses flowers as exclusive breeding and feeding sites, in two distinct Brazilian populations. The absence of four genes involved in CI from this genome, together with literature reports of low frequencies of infected flies in wild populations that contain high mitogenome polymorphism, suggests that this bacterium does not induce CI in D. incompta. Phylogenomic analysis placed Wolbachia infecting D. incompta as closely related to the wMel strain which received such name since it was originally detected in Drosophila melanogaster. In addition, phylogenetic analysis using the Wolbachia surface protein gene and five genes used for multilocus sequence typing of Wolbachia found infecting Drosophila and other arthropod species of Old and New World displayed a complex evolutionary scenario involving recent horizontal transfer bursts in all major clades of Wolbachia pipens belonging to the supergroup A in both geographical regions.}, }
@article {pmid27114607, year = {2016}, author = {Li, YY and Fields, PG and Pang, BP and Floate, KD}, title = {Effects of Tetracycline and Rifampicin Treatments on the Fecundity of the Wolbachia -Infected Host, Tribolium confusum (Coleoptera: Tenebrionidae).}, journal = {Journal of economic entomology}, volume = {109}, number = {3}, pages = {1458-1464}, doi = {10.1093/jee/tow067}, pmid = {27114607}, issn = {1938-291X}, abstract = {We examined the effects of Wolbachia bacteria on the reproduction of the flour beetle Tribolium confusum (Coleoptera: Tenebrionidae) using different antibiotics and across generations. We first removed infections by rearing insects on a diet with tetracycline (T; 1.0, 2.0, 3.0, 5.0, 10.0 mg/g) or rifampicin (R; 0.1, 0.2, 0.3, 0.5, 1.0 mg/g). We then performed experimental crosses using adults two generations (G2) and four generations (G4) removed from antibiotic treatments. Results showed that use of rifampicin more readily cured infections. Egg hatch from crosses of uninfected females and infected males was 0, but averaged 84 to 91% for eggs from all other crosses. Elevated fecundity was observed for T-G2 females, but not for T-G4, R-G2, or R-G4 females. Cross type had little or no effect on the sex of F 1 offspring, which averaged 52% female. These collective results support previous findings that show that Wolbachia in T. confusum causes 100% cytoplasmic incompatibility and emphasize that the antibiotic treatment used to remove infections may have additional consequences (e.g., elevated fecundity) that may not be apparent in subsequent generations.}, }
@article {pmid27114069, year = {2016}, author = {Hall, AA and Morrow, JL and Fromont, C and Steinbauer, MJ and Taylor, GS and Johnson, SN and Cook, JM and Riegler, M}, title = {Codivergence of the primary bacterial endosymbiont of psyllids versus host switches and replacement of their secondary bacterial endosymbionts.}, journal = {Environmental microbiology}, volume = {18}, number = {8}, pages = {2591-2603}, doi = {10.1111/1462-2920.13351}, pmid = {27114069}, issn = {1462-2920}, mesh = {Animals ; Biological Evolution ; Enterobacteriaceae/*genetics/*growth &amp; development ; Hemiptera/*microbiology ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Coevolution between insects and bacterial endosymbionts contributes to the success of many insect lineages. For the first time, we tested for phylogenetic codivergence across multiple taxonomic scales, from within genera to superfamily between 36 psyllid species of seven recognised families (Hemiptera: Psylloidea), their exclusive primary endosymbiont Carsonella and more diverse secondary endosymbionts (S-endosymbionts). Within Aphalaridae, we found that Carsonella and S-endosymbionts were fixed in one Glycaspis and 12 Cardiaspina populations. The dominant S-endosymbiont was Arsenophonus, while Sodalis was detected in one Cardiaspina species. We demonstrated vertical transmission for Carsonella and Arsenophonus in three Cardiaspina species. We found strong support for strict cospeciation and validated the informative content of Carsonella as extended host genome for inference of psyllid relationships. However, S-endosymbiont and host phylogenies were incongruent, and displayed signs of host switching and endosymbiont replacement. The high incidence of Arsenophonus in psyllids and other plant sap-feeding Hemiptera may be due to repeated host switching within this group. In two psyllid lineages, Arsenophonus and Sodalis genes exhibited accelerated evolutionary rates and AT-biases characteristic of long-term host associations. Together with strict vertical transmission and 100% prevalence within host populations, our results suggest an obligate, and not facultative, symbiosis between psyllids and some S-endosymbionts.}, }
@article {pmid27113731, year = {2016}, author = {Dietersdorfer, E and Cervero-Aragó, S and Sommer, R and Kirschner, AK and Walochnik, J}, title = {Optimized methods for Legionella pneumophila release from its Acanthamoeba hosts.}, journal = {BMC microbiology}, volume = {16}, number = {}, pages = {74}, pmid = {27113731}, issn = {1471-2180}, mesh = {Acanthamoeba/growth &amp; development/*microbiology ; Bacterial Load ; Bacteriological Techniques/*methods ; Coculture Techniques ; Legionella pneumophila/*growth &amp; development/isolation &amp; purification ; Symbiosis ; Water Microbiology ; }, abstract = {BACKGROUND: Free-living amoebae (FLA) and particularly acanthamoebae serve as vehicles and hosts for Legionella pneumophila, among other pathogenic microorganisms. Within the amoebae, L. pneumophila activates a complex regulatory pathway that enables the bacteria to resist amoebal digestion and to replicate. Moreover, the amoebae provide the bacteria protection against harsh environmental conditions and disinfectants commonly used in engineered water systems. To study this ecological relationship, co-culture and infection models have been used. However, there is a lack of data regarding the effectiveness of the different methods used to release intracellular bacteria from their amoebal hosts. The aim of this study was to evaluate the impact of the methods used to release intracellular L. pneumophila cells on the culturability of the bacteria. Furthermore, the standard method ISO 11731:1998 for the recovery and enumeration of Legionella from water samples was evaluated for its suitability to quantify intracellular bacteria.<br><br>RESULTS: The effectiveness of the eight release treatments applied to L. pneumophila and Acanthamoeba strains in a free-living state varied between bacterial strains. Moreover, the current study provides numerical data on the state of co-culture suspensions at different time points. The release treatments enhanced survival of both microorganisms in co-cultures of L. pneumophila and Acanthamoeba. Passage through a needle (21G, 27G) and centrifugation at 10,000 &#xd7; g showed the highest bacterial counts when releasing the bacteria from the intracellular state. Regarding the ISO 11731:1998 method, one of the tested strains showed no differences between the recovery rates of associated and free-living L. pneumophila. However, a reduced bacterial recovery rate was observed for the second L. pneumophila strain used, and this difference is likely linked to the survival of the amoebae.<br><br>CONCLUSIONS: Mechanical release treatments were the most effective methods for providing bacterial release without the use of chemicals that could compromise further study of the intracellular bacteria. The current results demonstrated that the recovery of L. pneumophila from water systems may be underestimated if protozoal membranes are not disrupted.}, }
@article {pmid27110057, year = {2016}, author = {Libro, S and Slatko, BE and Foster, JM}, title = {Characterization of innate immunity genes in the parasitic nematode Brugia malayi.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {68}, number = {}, pages = {145-155}, pmid = {27110057}, issn = {0334-5114}, abstract = {The filarial nematode Brugia malayi is one of the causative agents of lymphatic filariasis, a neglected tropical disease that affects 120 million people worldwide. The limited effectiveness of available anthelmintics and the absence of a vaccine have prompted extensive research on the interaction between Brugia and its obligate bacterial endosymbiont, Wolbachia. Recent studies suggest that Wolbachia is able to manipulate its nematode host immunity but relatively little is known about the immune system of filarial nematodes. Therefore, elucidation of the mechanisms underlying the immune system of B. malayi may be useful for understanding how the symbiotic relationship is maintained and help in the identification of new drug targets. In order to characterize the main genetic pathways involved in B. malayi immunity, we exposed adult female worms to two bacterial lysates (Escherichia coli and Bacillus amyloliquefaciens), dsRNA and dsDNA. We performed transcriptome sequencing of worms exposed to each immune elicitor at two different timepoints. Gene expression analysis of untreated and immune-challenged worms was performed to characterize gene expression patterns associated with each type of immune stimulation. Our results indicate that different immune elicitors produced distinct expression patterns in B. malayi, with changes in the expression of orthologs of well-characterized C. elegans immune pathways such as insulin, TGF-β, and p38 MAPK pathways, as well as C-type lectins and several stress-response genes.}, }
@article {pmid27102878, year = {2016}, author = {Guha, S and Sarkar, M and Ganguly, P and Uddin, MR and Mandal, S and DasGupta, M}, title = {Segregation of nod-containing and nod-deficient bradyrhizobia as endosymbionts of Arachis hypogaea and as endophytes of Oryza sativa in intercropped fields of Bengal Basin, India.}, journal = {Environmental microbiology}, volume = {18}, number = {8}, pages = {2575-2590}, doi = {10.1111/1462-2920.13348}, pmid = {27102878}, issn = {1462-2920}, mesh = {Acyltransferases/genetics ; Arachis/*microbiology ; Bradyrhizobium/*genetics/*growth &amp; development/isolation &amp; purification ; Endophytes/*physiology ; India ; Oryza/*microbiology ; Phenotype ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rec A Recombinases/genetics ; Symbiosis/*physiology ; }, abstract = {Bradyrhizobial invasion in dalbergoid legumes like Arachis hypogaea and endophytic bacterial invasions in non-legumes like Oryza sativa occur through epidermal cracks. Here, we show that there is no overlap between the bradyrhizobial consortia that endosymbiotically and endophytically colonise these plants. To minimise contrast due to phylogeographic isolation, strains were collected from Arachis/Oryza intercropped fields and a total of 17 bradyrhizobia from Arachis (WBAH) and 13 from Oryza (WBOS) were investigated. 16SrRNA and concatenated dnaK-glnII-recA phylogeny clustered the nodABC-positive WBAH and nodABC-deficient WBOS strains in two distinct clades. The in-field segregation is reproducible under controlled conditions which limits the factors that influence their competitive exclusion. While WBAH renodulated Arachis successfully, WBOS nodulated in an inefficient manner. Thus, Arachis, like other Aeschynomene legumes support nod-independent symbiosis that was ineffectual in natural fields. In Oryza, WBOS recolonised endophytically and promoted its growth. WBAH however caused severe chlorosis that was completely overcome when coinfected with WBOS. This explains the exclusive recovery of WBOS in Oryza in natural fields and suggests Nod-factors to have a role in counterselection of WBAH. Finally, canonical soxY1 and thiosulphate oxidation could only be detected in WBOS indicating loss of metabolic traits in WBAH with adaptation of symbiotic lifestyle.}, }
@article {pmid27100359, year = {2016}, author = {Waits, DS and Santos, SR and Thornhill, DJ and Li, Y and Halanych, KM}, title = {Evolution of Sulfur Binding by Hemoglobin in Siboglinidae (Annelida) with Special Reference to Bone-Eating Worms, Osedax.}, journal = {Journal of molecular evolution}, volume = {82}, number = {4-5}, pages = {219-229}, pmid = {27100359}, issn = {1432-1432}, mesh = {Animals ; Annelida/genetics ; Bacteria/genetics ; Biological Evolution ; Bone and Bones ; Cysteine/genetics ; Ecosystem ; Hemoglobins/*genetics/metabolism ; High-Throughput Nucleotide Sequencing ; Phylogeny ; Polychaeta/*genetics/metabolism ; Sulfur/metabolism ; Symbiosis ; Transcriptome ; }, abstract = {Most members of Siboglinidae (Annelida) harbor endosymbiotic bacteria that allow them to thrive in extreme environments such as hydrothermal vents, methane seeps, and whale bones. These symbioses are enabled by specialized hemoglobins (Hbs) that are able to bind hydrogen sulfide for transportation to their chemosynthetic endosymbionts. Sulfur-binding capabilities are hypothesized to be due to cysteine residues at key positions in both vascular and coelomic Hbs, especially in the A2 and B2 chains. Members of the genus Osedax, which live on whale bones, do not have chemosynthetic endosymbionts, but instead harbor heterotrophic bacteria capable of breaking down complex organic compounds. Although sulfur-binding capabilities are important in other siboglinids, we questioned whether Osedax retained these cysteine residues and the potential ability to bind hydrogen sulfide. To answer these questions, we used high-throughput DNA sequencing to isolate and analyze Hb sequences from 8 siboglinid lineages. For Osedax mucofloris, we recovered three (A1, A2, and B1) Hb chains, but the B2 chain was not identified. Hb sequences from gene subfamilies A2 and B2 were translated and aligned to determine conservation of cysteine residues at previously identified key positions. Hb linker sequences were also compared to determine similarity between Osedax and siboglinids/sulfur-tolerant annelids. For O. mucofloris, our results found conserved cysteines within the Hb A2 chain. This finding suggests that Hb in O. mucofloris has retained some capacity to bind hydrogen sulfide, likely due to the need to detoxify this chemical compound that is abundantly produced within whale bones.}, }
@article {pmid27099709, year = {2016}, author = {Parkinson, JF and Gobin, B and Hughes, WO}, title = {Heritability of symbiont density reveals distinct regulatory mechanisms in a tripartite symbiosis.}, journal = {Ecology and evolution}, volume = {6}, number = {7}, pages = {2053-2060}, pmid = {27099709}, issn = {2045-7758}, abstract = {Beneficial eukaryotic-bacterial partnerships are integral to animal and plant evolution. Understanding the density regulation mechanisms behind bacterial symbiosis is essential to elucidating the functional balance between hosts and symbionts. Citrus mealybugs, Planococcus citri (Risso), present an excellent model system for investigating the mechanisms of symbiont density regulation. They contain two obligate nutritional symbionts, Moranella endobia, which resides inside Tremblaya princeps, which has been maternally transmitted for 100-200 million years. We investigate whether host genotype may influence symbiont density by crossing mealybugs from two inbred laboratory-reared populations that differ substantially in their symbiont density to create hybrids. The density of the M. endobia symbiont in the hybrid hosts matched that of the maternal parent population, in keeping with density being determined either by the symbiont or the maternal genotype. However, the density of the T. princeps symbiont was influenced by the paternal host genotype. The greater dependency of T. princeps on its host may be due to its highly reduced genome. The decoupling of T. princeps and M. endobia densities, in spite of their intimate association, suggests that distinct regulatory mechanisms can be at work in symbiotic partnerships, even when they are obligate and mutualistic.}, }
@article {pmid27094992, year = {2016}, author = {Mohamed, AR and Cumbo, V and Harii, S and Shinzato, C and Chan, CX and Ragan, MA and Bourne, DG and Willis, BL and Ball, EE and Satoh, N and Miller, DJ}, title = {The transcriptomic response of the coral Acropora digitifera to a competent Symbiodinium strain: the symbiosome as an arrested early phagosome.}, journal = {Molecular ecology}, volume = {25}, number = {13}, pages = {3127-3141}, doi = {10.1111/mec.13659}, pmid = {27094992}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*genetics ; Dinoflagellida/*physiology ; High-Throughput Nucleotide Sequencing ; Phagosomes/*genetics ; Sequence Analysis, RNA ; Symbiosis/*genetics ; *Transcriptome ; }, abstract = {Despite the ecological significance of the relationship between reef-building corals and intracellular photosynthetic dinoflagellates of the genus Symbiodinium, very little is known about the molecular mechanisms involved in its establishment. Indeed, microarray-based analyses point to the conclusion that host gene expression is largely or completely unresponsive during the establishment of symbiosis with a competent strain of Symbiodinium. In this study, the use of Illumina RNA-Seq technology allowed detection of a transient period of differential expression involving a small number of genes (1073 transcripts; <3% of the transcriptome) 4 h after the exposure of Acropora digitifera planulae to a competent strain of Symbiodinium (a clade B strain). This phenomenon has not previously been detected as a consequence of both the lower sensitivity of the microarray approaches used and the sampling times used. The results indicate that complex changes occur, including transient suppression of mitochondrial metabolism and protein synthesis, but are also consistent with the hypothesis that the symbiosome is a phagosome that has undergone early arrest, raising the possibility of common mechanisms in the symbiotic interactions of corals and symbiotic sea anemones with their endosymbionts.}, }
@article {pmid27094934, year = {2016}, author = {Liu, YH and Kang, ZW and Guo, Y and Zhu, GS and Shah, MM and Song, Y and Fan, YL and Jing, X and Liu, TX}, title = {Nitrogen hurdle of host alternation for a polyphagous aphid and the associated changes of endosymbionts.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {24781}, pmid = {27094934}, issn = {2045-2322}, mesh = {Amino Acids/chemistry ; Animals ; Aphids/*physiology ; Brassica ; *Host-Parasite Interactions ; Nitrogen/*metabolism ; Phloem/metabolism ; Plant Proteins/chemistry/metabolism ; Plants/*metabolism/*parasitology ; *Symbiosis ; }, abstract = {Low proportion of essential amino acids (EAAs) is one of the barriers for animals to use phloem as a diet. Endosymbionts with EAAs synthesis functions are considered crucial for ameliorating the lack of EAAs in insects' diets. In this study, we transferred the insects from a cabbage-reared Myzus persicae population onto 3 new plant species including eggplant, tobacco and spinach. The performance on these plants was evaluated and the dynamics of endosymbionts in relation to this host alternation were recorded. We found that the EAAs ratio in phloem was largely determined by the concentrations of non-essential amino acids and the higher proportion of EAAs seemed to favor the population establishment on new plant species and the growth of primary endosymbionts inside insects, which indicated that nitrogen quality was an important factor for aphids to infest and spread on new plant hosts.}, }
@article {pmid27089431, year = {2016}, author = {Rainey, SM and Martinez, J and McFarlane, M and Juneja, P and Sarkies, P and Lulla, A and Schnettler, E and Varjak, M and Merits, A and Miska, EA and Jiggins, FM and Kohl, A}, title = {Wolbachia Blocks Viral Genome Replication Early in Infection without a Transcriptional Response by the Endosymbiont or Host Small RNA Pathways.}, journal = {PLoS pathogens}, volume = {12}, number = {4}, pages = {e1005536}, pmid = {27089431}, issn = {1553-7374}, support = {094664MA/WT_/Wellcome Trust/United Kingdom ; MC_UU_12014/MRC_/Medical Research Council/United Kingdom ; MC_UP_1102/13/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; /WT_/Wellcome Trust/United Kingdom ; MC_UP_A550_1031/MRC_/Medical Research Council/United Kingdom ; /CRUK_/Cancer Research UK/United Kingdom ; }, mesh = {Animals ; Cell Line ; Drosophila melanogaster/*genetics ; *Genome, Viral/genetics ; Humans ; MicroRNAs/genetics ; RNA, Small Interfering/genetics ; RNA, Viral/*genetics ; Semliki forest virus ; Symbiosis ; Transcription, Genetic ; Virus Replication/*physiology ; Wolbachia/*metabolism ; }, abstract = {The intracellular endosymbiotic bacterium Wolbachia can protect insects against viral infection, and is being introduced into mosquito populations in the wild to block the transmission of arboviruses that infect humans and are a major public health concern. To investigate the mechanisms underlying this antiviral protection, we have developed a new model system combining Wolbachia-infected Drosophila melanogaster cell culture with the model mosquito-borne Semliki Forest virus (SFV; Togaviridae, Alphavirus). Wolbachia provides strong antiviral protection rapidly after infection, suggesting that an early stage post-infection is being blocked. Wolbachia does appear to have major effects on events distinct from entry, assembly or exit as it inhibits the replication of an SFV replicon transfected into the cells. Furthermore, it causes a far greater reduction in the expression of proteins from the 3' open reading frame than the 5' non-structural protein open reading frame, indicating that it is blocking the replication of viral RNA. Further to this separation of the replicase proteins and viral RNA in transreplication assays shows that uncoupling of viral RNA and replicase proteins does not overcome Wolbachia's antiviral activity. This further suggests that replicative processes are disrupted, such as translation or replication, by Wolbachia infection. This may occur by Wolbachia mounting an active antiviral response, but the virus did not cause any transcriptional response by the bacterium, suggesting that this is not the case. Host microRNAs (miRNAs) have been implicated in protection, but again we found that host cell miRNA expression was unaffected by the bacterium and neither do our findings suggest any involvement of the antiviral siRNA pathway. We conclude that Wolbachia may directly interfere with early events in virus replication such as translation of incoming viral RNA or RNA transcription, and this likely involves an intrinsic (as opposed to an induced) mechanism.}, }
@article {pmid27080728, year = {2016}, author = {Elgart, M and Stern, S and Salton, O and Gnainsky, Y and Heifetz, Y and Soen, Y}, title = {Impact of gut microbiota on the fly's germ line.}, journal = {Nature communications}, volume = {7}, number = {}, pages = {11280}, pmid = {27080728}, issn = {2041-1723}, mesh = {Aldehyde Dehydrogenase/genetics ; Animals ; Animals, Genetically Modified ; Bacteria/classification/genetics ; Drosophila Proteins/genetics ; Drosophila melanogaster/embryology/*genetics/microbiology ; Embryo, Nonmammalian/embryology/*metabolism/microbiology ; Female ; Gastrointestinal Microbiome/*genetics/physiology ; Gene Expression Regulation, Developmental ; Male ; Oocytes/*metabolism ; Oogenesis/genetics ; RNA, Ribosomal, 16S/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; }, abstract = {Unlike vertically transmitted endosymbionts, which have broad effects on their host's germ line, the extracellular gut microbiota is transmitted horizontally and is not known to influence the germ line. Here we provide evidence supporting the influence of these gut bacteria on the germ line of Drosophila melanogaster. Removal of the gut bacteria represses oogenesis, expedites maternal-to-zygotic-transition in the offspring and unmasks hidden phenotypic variation in mutants. We further show that the main impact on oogenesis is linked to the lack of gut Acetobacter species, and we identify the Drosophila Aldehyde dehydrogenase (Aldh) gene as an apparent mediator of repressed oogenesis in Acetobacter-depleted flies. The finding of interactions between the gut microbiota and the germ line has implications for reproduction, developmental robustness and adaptation.}, }
@article {pmid27079679, year = {2016}, author = {Zhao, Y and Zhang, S and Luo, JY and Wang, CY and Lv, LM and Cui, JJ}, title = {Bacterial communities of the cotton aphid Aphis gossypii associated with Bt cotton in northern China.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {22958}, pmid = {27079679}, issn = {2045-2322}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*classification/genetics ; Biodiversity ; China ; Cluster Analysis ; Gossypium/parasitology ; *Microbiota ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Aphids are infected with a wide variety of endosymbionts that can confer ecologically relevant traits. However, the bacterial communities of most aphid species are still poorly characterized. This study investigated the bacterial diversity of the cotton aphid Aphis gossypii associated with Bt cotton in northern China by targeting the V4 region of the 16S rDNA using the Illumina MiSeq platform. Our sequencing data revealed that bacterial communities of A. gossypii were generally dominated by the primary symbiont Buchnera, together with the facultative symbionts Arsenophonus and Hamiltonella. To our knowledge, this is the first report documenting the facultative symbiont Hamiltonella in A. gossypii. Moreover, the bacterial community structure was similar within aphids from the same province, but distinct among those from different provinces. The taxonomic diversity of the bacterial community is greater in Hebei Province compared with in samples from Henan and Shandong Provinces. The selection pressure exerted by the different geographical locations could explain the differences found among the various provinces. These findings broaden our understanding of the interactions among aphids, endosymbionts and their environments, and provide clues to develop potential biocontrol techniques against this cotton aphid.}, }
@article {pmid27066304, year = {2016}, author = {Naito, M and Pawlowska, TE}, title = {The role of mobile genetic elements in evolutionary longevity of heritable endobacteria.}, journal = {Mobile genetic elements}, volume = {6}, number = {1}, pages = {e1136375}, pmid = {27066304}, issn = {2159-2543}, abstract = {The movement of mobile genetic elements (MGEs), including bacteriophages, insertion sequence (IS) elements, and integrative and conjugative elements (ICEs) can have profound effects on bacterial evolution by introducing novel genes, or disrupting the existing ones. Obligate endobacteria are a distinctive group of bacteria that reside within the intracellular compartments of their eukaryotic hosts. Many obligate endobacteria are reproductively dependent on their hosts. Vertical transmission, in addition to degenerative genome contraction and loss of MGEs, makes heritable endobacteria vulnerable to Muller's ratchet, a process that jeopardizes evolutionary longevity of small populations. Mycoplasma-related endobacteria (MRE) are ancient heritable endosymbionts of arbuscular mycorrhizal fungi. Their genomes harbour numerous MGEs. To explore the significance of MGEs in the evolution of MRE and other obligate endobacteria, we analyze the impact of transmission mode, recombination, and evolutionary age on the maintenance of MGEs. Furthermore, we discuss the ability of MGEs to act as sites of gene conversion and recombination in endobacterial genomes. We propose that MGEs are important instruments of genome shuffling, contributing to population heterogeneity and evolutionary longevity in heritable obligate endobacteria.}, }
@article {pmid27066241, year = {2016}, author = {Mateos, M and Winter, L and Winter, C and Higareda-Alvear, VM and Martinez-Romero, E and Xie, J}, title = {Independent origins of resistance or susceptibility of parasitic wasps to a defensive symbiont.}, journal = {Ecology and evolution}, volume = {6}, number = {9}, pages = {2679-2687}, pmid = {27066241}, issn = {2045-7758}, abstract = {Insect microbe associations are diverse, widespread, and influential. Among the fitness effects of microbes on their hosts, defense against natural enemies is increasingly recognized as ubiquitous, particularly among those associations involving heritable, yet facultative, bacteria. Protective mutualisms generate complex ecological and coevolutionary dynamics that are only beginning to be elucidated. These depend in part on the degree to which symbiont-mediated protection exhibits specificity to one or more members of the natural enemy community. Recent findings in a well-studied defensive mutualism system (i.e., aphids, bacteria, parasitoid wasps) reveal repeated instances of evolution of susceptibility or resistance to defensive bacteria by parasitoids. This study searched for similar patterns in an emerging model system for defensive mutualisms: the interaction of Drosophila, bacteria in the genus Spiroplasma, and wasps that parasitize larval stages of Drosophila. Previous work indicated that three divergent species of parasitic wasps are strongly inhibited by the presence of Spiroplasma in three divergent species of Drosophila, including D. melanogaster. The results of this study uncovered two additional wasp species that are susceptible to Spiroplasma and two that are unaffected by Spiroplasma, implying at least two instances of loss or gain of susceptibility to Spiroplasma among larval parasitoids of Drosophila.}, }
@article {pmid27066182, year = {2016}, author = {Waller, RF and Gornik, SG and Koreny, L and Pain, A}, title = {Metabolic pathway redundancy within the apicomplexan-dinoflagellate radiation argues against an ancient chromalveolate plastid.}, journal = {Communicative &amp; integrative biology}, volume = {9}, number = {1}, pages = {e1116653}, pmid = {27066182}, issn = {1942-0889}, support = {MR/M011690/1/MRC_/Medical Research Council/United Kingdom ; }, abstract = {The chromalveolate hypothesis presents an attractively simple explanation for the presence of red algal-derived secondary plastids in 5 major eukaryotic lineages: "chromista" phyla, cryptophytes, haptophytes and ochrophytes; and alveolate phyla, dinoflagellates and apicomplexans. It posits that a single secondary endosymbiotic event occurred in a common ancestor of these diverse groups, and that this ancient plastid has since been maintained by vertical inheritance only. Substantial testing of this hypothesis by molecular phylogenies has, however, consistently failed to provide support for the predicted monophyly of the host organisms that harbour these plastids-the "chromalveolates." This lack of support does not disprove the chromalveolate hypothesis per se, but rather drives the proposed endosymbiosis deeper into the eukaryotic tree, and requires multiple plastid losses to have occurred within intervening aplastidic lineages. An alternative perspective on plastid evolution is offered by considering the metabolic partnership between the endosymbiont and its host cell. A recent analysis of metabolic pathways in a deep-branching dinoflagellate indicates a high level of pathway redundancy in the common ancestor of apicomplexans and dinoflagellates, and differential losses of these pathways soon after radiation of the major extant lineages. This suggests that vertical inheritance of an ancient plastid in alveolates is highly unlikely as it would necessitate maintenance of redundant pathways over very long evolutionary timescales.}, }
@article {pmid27064460, year = {2016}, author = {Hahn, MW and Schmidt, J and Pitt, A and Taipale, SJ and Lang, E}, title = {Reclassification of four Polynucleobacter necessarius strains as representatives of Polynucleobacter asymbioticus comb. nov., Polynucleobacter duraquae sp. nov., Polynucleobacter yangtzensis sp. nov. and Polynucleobacter sinensis sp. nov., and emended description of Polynucleobacter necessarius.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {66}, number = {8}, pages = {2883-2892}, pmid = {27064460}, issn = {1466-5034}, support = {I 482/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Bacterial Typing Techniques ; Base Composition ; Burkholderiaceae/*classification ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Multilocus Sequence Typing ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; }, abstract = {Genome comparisons based on average nucleotide identity (ANI) values of four strains currently classified as Polynucleobacter necessarius subsp. asymbioticus resulted in ANI values of 75.7-78.4 %, suggesting that each of those strains represents a separate species. The species P. necessarius was proposed by Heckmann and Schmidt in 1987 to accommodate obligate endosymbionts of ciliates affiliated with the genus Euplotes. The required revision of this species is, however, hampered by the fact, that this species is based only on a description and lacks a type strain available as pure culture. Furthermore, the ciliate culture Euplotes aediculatus ATCC 30859, on which the description of the species was based, is no longer available. We found another Euplotes aediculatus culture (Ammermann) sharing the same origin with ATCC 30859 and proved the identity of the endosymbionts contained in the two cultures. A multilocus sequence comparison approach was used to estimate if the four strains currently classified as Polynucleobacternecessarius subsp. asymbioticus share ANI values with the endosymbiont in the Ammermann culture above or below the threshold for species demarcation. A significant correlation (R2 0.98, P<0.0001) between multilocus sequence similarity and ANI values of genome-sequenced strains enabled the prediction that it is highly unlikely that these four strains belong to the species P. necessarius. We propose reclassification of strains QLW-P1DMWA-1T (=DSM 18221T=CIP 109841T), MWH-MoK4T (=DSM 21495T=CIP 110977T), MWH-JaK3T (=DSM 21493T=CIP 110976T) and MWH-HuW1T (=DSM 21492T=CIP 110978T) as Polynucleobacter asymbioticus comb. nov., Polynucleobacter duraquae sp. nov., Polynucleobacter yangtzensis sp. nov. and Polynucleobacter sinensis sp. nov., respectively.}, }
@article {pmid27055293, year = {2015}, author = {Goryacheva, II and Gorelova, TV and Andrianov, BV}, title = {[Drosophila melanogaster Cell Culture as an Experimental Model to Study Recombination in Wolbachia pipientis].}, journal = {Genetika}, volume = {51}, number = {12}, pages = {1345-1350}, pmid = {27055293}, issn = {0016-6758}, mesh = {Animals ; Cell Culture Techniques/*methods ; Cells, Cultured ; Drosophila melanogaster ; *Recombination, Genetic ; Wolbachia/*genetics/*growth &amp; development ; }, abstract = {Wolbachiapipientis is an obligate intracellular endosymbiont that commonly infects arthropods. Comparative genomic studies of Wolbachia reveal traces of numerous events of intergenic and intragenic recombination. The molecular mechanisms of recombination in Wolbachia are not currently known. We conducted experimental verification of the possibility of recombination of two strains of Wolbachia: wMel and wRi, after using these strains for double infection of the Dm2008Wb1 (D. melanogaster) cell culture clone permissive to Wolbachia. We obtained cell culture subclones with double Wolbachia infection and subclones infected only by strain wMel. Dual infection with the Wolbachia strains wMel and wRi has been stably maintained in the subclones for two years. Multilocus sequence typing (MLST) of the obtained subclones revealed the presence of dual infection for all five Wolbachia genes used for MLST Cloning and nucleotide sequence analysis of individual forms of the fbpA gene of Wolbachia from cell clones with dual infection showed intragenic recombination events between strains wMel and wRi, which occurred in the permanent D. melanogaster culture cell culture. The fact that putative recombination sites contain no insertions of nucleotide sequences of phages or IS elements, as well as the asymmetrical character of recombinants, favors the hypothesis that gene conversion is the most probable molecular mechanism of recombination in Wolbachia.}, }
@article {pmid27048461, year = {2016}, author = {Marinov, GK and Lynch, M}, title = {Conservation and divergence of the histone code in nucleomorphs.}, journal = {Biology direct}, volume = {11}, number = {1}, pages = {18}, pmid = {27048461}, issn = {1745-6150}, mesh = {Chromatin/*genetics ; Cyanobacteria/genetics ; Histone Code/*genetics ; Histones/*metabolism ; }, abstract = {BACKGROUND: Nucleomorphs, the remnant nuclei of photosynthetic algae that have become endosymbionts to other eukaryotes, represent a unique example of convergent reductive genome evolution in eukaryotes, having evolved independently on two separate occasions in chlorarachniophytes and cryptophytes. The nucleomorphs of the two groups have evolved in a remarkably convergent manner, with numerous very similar features. Chief among them is the extreme reduction and compaction of nucleomorph genomes, with very small chromosomes and extremely short or even completely absent intergenic spaces. These characteristics pose a number of intriguing questions regarding the mechanisms of transcription and gene regulation in such a crowded genomic context, in particular in terms of the functioning of the histone code, which is common to almost all eukaryotes and plays a central role in chromatin biology.<br><br>RESULTS: This study examines the sequences of nucleomorph histone proteins in order to address these issues. Remarkably, all classical transcription- and repression-related components of the histone code seem to be missing from chlorarachniophyte nucleomorphs. Cryptophyte nucleomorph histones are generally more similar to the conventional eukaryotic state; however, they also display significant deviations from the typical histone code. Based on the analysis of specific components of the code, we discuss the state of chromatin and the transcriptional machinery in these nuclei.<br><br>CONCLUSIONS: The results presented here shed new light on the mechanisms of nucleomorph transcription and gene regulation and provide a foundation for future studies of nucleomorph chromatin and transcriptional biology.}, }
@article {pmid27041341, year = {2016}, author = {Greiman, SE and Tkach, VV}, title = {The numbers game: quantitative analysis of Neorickettsia sp. propagation through complex life cycle of its digenean host using real-time qPCR.}, journal = {Parasitology research}, volume = {115}, number = {7}, pages = {2779-2788}, pmid = {27041341}, issn = {1432-1955}, mesh = {Animals ; Life Cycle Stages ; Lymnaea/*parasitology ; Mesocricetus ; Neorickettsia/*physiology ; Real-Time Polymerase Chain Reaction ; Trematoda/genetics/growth &amp; development/*microbiology ; }, abstract = {Bacteria of the genus Neorickettsia are obligate intracellular endosymbionts of parasitic flukes (Digenea) and are passed through the entire complex life cycle of the parasite by vertical transmission. Several species of Neorickettsia are known to cause diseases in domestic animals, wildlife, and humans. Quantitative data on the transmission of the bacteria through the digenean life cycle is almost completely lacking. This study quantified for the first time the abundance of Neorickettsia within multiple stages of the life cycle of the digenean Plagiorchis elegans. Snails Lymnaea stagnalis collected from a pond in North Dakota were screened for the presence of digenean cercariae, which were subsequently tested for the presence of Neorickettsia. Three L. stagnalis were found shedding P. elegans cercariae infected with Neorickettsia. These snails were used to initiate three separate laboratory life cycles and obtain all life cycle stages for bacterial quantification. A quantitative real-time PCR assay targeting the GroEL gene was developed to enumerate Neorickettsia sp. within different stages of the digenean life cycle. The number of bacteria significantly increased throughout all stages, from eggs to adults. The two largest increases in number of bacteria occurred during the period from eggs to cercariae and from 6-day metacercariae to 48-h juvenile worms. These two periods seem to be the most important for Neorickettsia propagation through the complex digenean life cycle and maturation in the definitive host.}, }
@article {pmid27041060, year = {2016}, author = {Beran, F and Gershenzon, J}, title = {Microbes matter: herbivore gut endosymbionts play a role in breakdown of host plant toxins.}, journal = {Environmental microbiology}, volume = {18}, number = {5}, pages = {1306-1307}, doi = {10.1111/1462-2920.13258}, pmid = {27041060}, issn = {1462-2920}, mesh = {*Herbivory ; *Toxins, Biological ; }, }
@article {pmid27037587, year = {2016}, author = {Yang, A and Narechania, A and Kim, E}, title = {Rickettsial endosymbiont in the "early-diverging" streptophyte green alga Mesostigma viride.}, journal = {Journal of phycology}, volume = {52}, number = {2}, pages = {219-229}, doi = {10.1111/jpy.12385}, pmid = {27037587}, issn = {1529-8817}, mesh = {Chlorophyta/genetics/*microbiology/ultrastructure ; In Situ Hybridization, Fluorescence ; Likelihood Functions ; Microscopy, Fluorescence ; Molecular Sequence Annotation ; Phylogeny ; RNA, Messenger/genetics/metabolism ; RNA, Ribosomal, 16S/genetics ; Ribosome Subunits, Small ; Rickettsia/*physiology ; Streptophyta/*microbiology/ultrastructure ; *Symbiosis ; Transcriptome/genetics ; }, abstract = {A bacterial endosymbiont was unexpectedly found in the "axenic" culture strain of the streptophyte green alga Mesostigma viride (NIES-995). Phylogenetic analyses based on 16S rRNA gene sequences showed that the symbiont belongs to the order Rickettsiales, specifically to the recently designated clade "Candidatus Megaira," which is closely related to the well-known Rickettsia clade. Rickettsiales bacteria of the "Ca. Megaira" clade are found in a taxonomically diverse array of eukaryotic hosts, including chlorophycean green algae, several ciliate species, and invertebrates such as Hydra. Transmission electron microscopy, fluorescence in situ hybridi-zation, and SYBR Green I staining experiments revealed that the endosymbiont of M. viride NIES-995 is rod shaped, typically occurs in clusters, and is surrounded by a halo-like structure, presumably formed by secretory substances from the bacterium. Two additional M. viride strains (NIES-296 and NIES-475), but not SAG50-1, were found to house the rickettsial endosymbiont. Analyses of strain NIES-995 transcriptome data indicated the presence of at least 91 transcriptionally active genes of symbiont origins. These include genes for surface proteins (e.g., rOmpB) that are known to play key roles in bacterial attachment onto host eukaryotes in related Rickettsia species. The assembled M. viride transcriptome includes transcripts that code for a suite of predicted algal-derived proteins, such as Ku70, WASH, SCAR, and CDC42, which may be important in the formation of the algal-rickettsial association.}, }
@article {pmid27033730, year = {2016}, author = {Wang, L and Lin, X and Goes, JI and Lin, S}, title = {Phylogenetic Analyses of Three Genes of Pedinomonas noctilucae, the Green Endosymbiont of the Marine Dinoflagellate Noctiluca scintillans, Reveal its Affiliation to the Order Marsupiomonadales (Chlorophyta, Pedinophyceae) under the Reinstated Name Protoeuglena noctilucae.}, journal = {Protist}, volume = {167}, number = {2}, pages = {205-216}, doi = {10.1016/j.protis.2016.02.005}, pmid = {27033730}, issn = {1618-0941}, mesh = {Base Sequence ; Chlorophyta/*classification/*genetics/metabolism ; DNA, Ribosomal/genetics ; Dinoflagellida/*physiology ; Eutrophication/*physiology ; Photosynthesis ; Phylogeny ; Phytoplankton/*classification ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {In the last decade, field studies in the northern Arabian Sea showed a drastic shift from diatom-dominated phytoplankton blooms to thick and widespread blooms of the green dinoflagellate, Noctiluca scintillans. Unlike the exclusively heterotrophic red form, which occurs widely in tropical to temperate coastal waters, the green Noctiluca contains a large number of endosymbiotic algal cells that can perform photosynthesis. These symbiotic microalgae were first described under the genus Protoeuglena Subrahmanyan and further transferred to Pedinomonas as P. noctilucae Sweeney. In this study, we used the 18S rDNA, rbcL and chloroplast 16S rDNA as gene markers, in combination with the previously reported morphological features, to re-examine the phylogenetic position of this endosymbiotic algal species. Phylogenetic trees inferred from these genes consistently indicated that P. noctilucae is distantly related to the type species of Pedinomonas. The sequences formed a monophyletic clade sister to the clade of Marsupiomonas necessitating the placement of the algal symbionts as an independent genus within the family Marsupiomonadaceae. Based on the phylogenetic affiliation and ecological characteristics of this alga as well as the priority rule of nomenclature, we reinstate the genus Protoeuglena and reclassify the endosymbiont as Protoeuglena noctilucae.}, }
@article {pmid27029936, year = {2016}, author = {van Baren, MJ and Bachy, C and Reistetter, EN and Purvine, SO and Grimwood, J and Sudek, S and Yu, H and Poirier, C and Deerinck, TJ and Kuo, A and Grigoriev, IV and Wong, CH and Smith, RD and Callister, SJ and Wei, CL and Schmutz, J and Worden, AZ}, title = {Evidence-based green algal genomics reveals marine diversity and ancestral characteristics of land plants.}, journal = {BMC genomics}, volume = {17}, number = {}, pages = {267}, pmid = {27029936}, issn = {1471-2164}, support = {P41 GM103412/GM/NIGMS NIH HHS/United States ; }, mesh = {*Biological Evolution ; Chlorophyta/*genetics ; Embryophyta/genetics ; *Genome, Plant ; Genomics/methods ; Introns ; Models, Genetic ; Multigene Family ; Phylogeny ; Proteome/genetics ; RNA, Algal/genetics ; Sequence Analysis, RNA ; Transcriptome ; }, abstract = {BACKGROUND: Prasinophytes are widespread marine green algae that are related to plants. Cellular abundance of the prasinophyte Micromonas has reportedly increased in the Arctic due to climate-induced changes. Thus, studies of these unicellular eukaryotes are important for marine ecology and for understanding Viridiplantae evolution and diversification.<br><br>RESULTS: We generated evidence-based Micromonas gene models using proteomics and RNA-Seq to improve prasinophyte genomic resources. First, sequences of four chromosomes in the 22 Mb Micromonas pusilla (CCMP1545) genome were finished. Comparison with the finished 21 Mb genome of Micromonas commoda (RCC299; named herein) shows they share &#x2264;8,141 of ~10,000 protein-encoding genes, depending on the analysis method. Unlike RCC299 and other sequenced eukaryotes, CCMP1545 has two abundant repetitive intron types and a high percent (26 %) GC splice donors. Micromonas has more genus-specific protein families (19 %) than other genome sequenced prasinophytes (11 %). Comparative analyses using predicted proteomes from other prasinophytes reveal proteins likely related to scale formation and ancestral photosynthesis. Our studies also indicate that peptidoglycan (PG) biosynthesis enzymes have been lost in multiple independent events in select prasinophytes and plants. However, CCMP1545, polar Micromonas CCMP2099 and prasinophytes from other classes retain the entire PG pathway, like moss and glaucophyte algae. Surprisingly, multiple vascular plants also have the PG pathway, except the Penicillin-Binding Protein, and share a unique bi-domain protein potentially associated with the pathway. Alongside Micromonas experiments using antibiotics that halt bacterial PG biosynthesis, the findings highlight unrecognized phylogenetic complexity in PG-pathway retention and implicate a role in chloroplast structure or division in several extant Viridiplantae lineages.<br><br>CONCLUSIONS: Extensive differences in gene loss and architecture between related prasinophytes underscore their divergence. PG biosynthesis genes from the cyanobacterial endosymbiont that became the plastid, have been selectively retained in multiple plants and algae, implying a biological function. Our studies provide robust genomic resources for emerging model algae, advancing knowledge of marine phytoplankton and plant evolution.}, }
@article {pmid27016694, year = {2016}, author = {Scheid, P}, title = {A strange endocytobiont revealed as largest virus.}, journal = {Current opinion in microbiology}, volume = {31}, number = {}, pages = {58-62}, doi = {10.1016/j.mib.2016.02.005}, pmid = {27016694}, issn = {1879-0364}, mesh = {A549 Cells ; Acanthamoeba/*virology ; Animals ; Cell Line ; Chlorocebus aethiops ; Dogs ; Genome, Viral/genetics ; Giant Viruses/*classification/genetics/*isolation &amp; purification ; Humans ; Keratitis/*virology ; Lens, Crystalline/*virology ; Madin Darby Canine Kidney Cells ; Symbiosis/physiology ; Vero Cells ; }, abstract = {A lot of endocytobionts (or endosymbionts) have been discovered within free-living amoebae in recent years. In this article the results of a long lasting effort to derive valuable data about an extraordinary spore-like infectious microorganism (endocytobiont, endosymbiont) within host amoebae (Acanthamoeba sp.) recently isolated from the contact lens case of a patient with keratitis, are presented. It took some time until this endocytobiont could be attributed to the genus Pandoravirus following a publication of two other pandoraviruses isolated from aquatic environments. Consequently the molecular biological investigation led to the taxonomic affiliation of the endocytobiont with the genus Pandoravirus and to the description of a new Pandoravirus species, Pandoravirus inopinatum after whole-genome sequencing in 2015. The fact that it was isolated from a contact lens container of a keratitis patient gives another dimension to these findings showing paradigmatically, how readily these 'new' giant viruses get to humans.}, }
@article {pmid27014194, year = {2016}, author = {Ding, JY and Shiu, JH and Chen, WM and Chiang, YR and Tang, SL}, title = {Genomic Insight into the Host-Endosymbiont Relationship of Endozoicomonas montiporae CL-33(T) with its Coral Host.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {251}, pmid = {27014194}, issn = {1664-302X}, abstract = {The bacterial genus Endozoicomonas was commonly detected in healthy corals in many coral-associated bacteria studies in the past decade. Although, it is likely to be a core member of coral microbiota, little is known about its ecological roles. To decipher potential interactions between bacteria and their coral hosts, we sequenced and investigated the first culturable endozoicomonal bacterium from coral, the E. montiporae CL-33(T). Its genome had potential sign of ongoing genome erosion and gene exchange with its host. Testosterone degradation and type III secretion system are commonly present in Endozoicomonas and may have roles to recognize and deliver effectors to their hosts. Moreover, genes of eukaryotic ephrin ligand B2 are present in its genome; presumably, this bacterium could move into coral cells via endocytosis after binding to coral's Eph receptors. In addition, 7,8-dihydro-8-oxoguanine triphosphatase and isocitrate lyase are possible type III secretion effectors that might help coral to prevent mitochondrial dysfunction and promote gluconeogenesis, especially under stress conditions. Based on all these findings, we inferred that E. montiporae was a facultative endosymbiont that can recognize, translocate, communicate and modulate its coral host.}, }
@article {pmid27012719, year = {2016}, author = {Wiwatanaratanabutr, I and Zhang, C}, title = {Wolbachia infections in mosquitoes and their predators inhabiting rice field communities in Thailand and China.}, journal = {Acta tropica}, volume = {159}, number = {}, pages = {153-160}, doi = {10.1016/j.actatropica.2016.03.026}, pmid = {27012719}, issn = {1873-6254}, mesh = {Agriculture ; Animals ; China ; Culicidae/*genetics/*microbiology ; DNA, Bacterial/*genetics ; Odonata/*genetics/*microbiology ; Oryza ; Thailand ; Wolbachia/*genetics/*isolation &amp; purification ; }, abstract = {Wolbachia are inherited, endocytoplasmic bacteria that infect a wide range of arthropods. Here is the first systematic report on the study of Wolbachia infection in mosquitoes and their predators from both Thailand and China. In Thailand, 632 mosquito specimens (20 spp.) and 424 insect predators (23 spp.) were collected from the rice agroecosystem, mostly from the Central region, followed by the Northeast, the North and the South and were inhabiting rice fields, wetlands and ditches. In China, 928 mosquitoes (15 spp.) and 149 insect predators (16 spp.) were collected from rice fields along the Weishan Lake in Shandong province. Specimens were classified in the orders Diptera, Coleoptera, Odonata and Hemiptera. Using wsp, ftsZ, 16S rRNA and groE gene amplifications, Wolbachia were detected in 12 mosquito spp. and 6 predator spp. from Thailand and 11 mosquito spp. and 5 predator spp. from China. The relative Wolbachia densities of these species were determined using quantitative real-time PCR. The mosquito, Aedes albopictus, and the predator, Agriocnemis femina, had the highest bacterial densities. These results imply that Wolbachia of supergroup B are distributed throughout these insects, probably via horizontal transmission in rice agroecosystems.}, }
@article {pmid27011222, year = {2016}, author = {Hoshina, R and Kusuoka, Y}, title = {DNA Analysis of Algal Endosymbionts of Ciliates Reveals the State of Algal Integration and the Surprising Specificity of the Symbiosis.}, journal = {Protist}, volume = {167}, number = {2}, pages = {174-184}, doi = {10.1016/j.protis.2016.02.004}, pmid = {27011222}, issn = {1618-0941}, mesh = {Base Sequence ; Chlorophyta/*genetics ; Ciliophora/*genetics ; DNA, Algal/*genetics ; DNA, Ribosomal/genetics ; DNA, Ribosomal Spacer/genetics ; Lakes ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Many freshwater protists harbor unicellular green algae within their cells, but little is known of their degree of integration and specificity. Using algae-targeted PCR of whole ciliate cells collected at irregular intervals over 15 months from Lake Biwa, Japan, we explored the SSU-ITS rDNA of the endosymbiotic algae and its changes over time, obtaining sequences of algal rDNA fragments from four ciliate species. A high proportion of clonal algae was evident within the ciliate cells. The differences observed in those sequences from the SSU through to the ITS region were less than 1%. The name 'Chlorb' is proposed for these algae, with the implication that they represent a single 'species.' The sequences of the algal DNA fragments were identical for any given host species throughout the collection period, thus we conclude that these four ciliates stably retain their algae over long term. In contrast, algal DNA fragments obtained from Didinium sp. were variable within each sample, which indicates that this ciliate only temporarily holds its algal cells. The ITS1 sequences of Chlorb populations are close (at intraspecific level) to those of algae isolated from ciliates in Austria, which raises the possibility that Chlorb algae are universally shared as symbionts among various ciliates.}, }
@article {pmid27001604, year = {2016}, author = {Cavalier-Smith, T and Chao, EE and Lewis, R}, title = {187-gene phylogeny of protozoan phylum Amoebozoa reveals a new class (Cutosea) of deep-branching, ultrastructurally unique, enveloped marine Lobosa and clarifies amoeba evolution.}, journal = {Molecular phylogenetics and evolution}, volume = {99}, number = {}, pages = {275-296}, doi = {10.1016/j.ympev.2016.03.023}, pmid = {27001604}, issn = {1095-9513}, mesh = {Amoebozoa/*classification/genetics ; Biological Evolution ; DNA, Protozoan/isolation &amp; purification/metabolism ; Phylogeny ; Protozoan Proteins/classification/genetics ; RNA, Ribosomal, 18S/classification/genetics ; }, abstract = {Monophyly of protozoan phylum Amoebozoa, and subdivision into subphyla Conosa and Lobosa each with different cytoskeletons, are well established. However early diversification of non-ciliate lobose amoebae (Lobosa) is poorly understood. To clarify it we used recently available transcriptomes to construct a 187-gene amoebozoan tree for 30 species, the most comprehensive yet. This robustly places new genus Atrichosa (formerly lumped with Trichosphaerium) within lobosan class Tubulinea, not Discosea as previously supposed. We identified an earliest diverging lobosan clade comprising marine amoebae armoured by porose scaliform cell-envelopes, here made a novel class Cutosea with two pseudopodially distinct new families. Cutosea comprise Sapocribrum, ATCC PRA-29 misidentified as 'Pessonella', plus from other evidence Squamamoeba. We confirm that Acanthamoeba and ATCC 50982 misidentified as Stereomyxa ramosa are closely related. Discosea have a strongly supported major subclade comprising Thecamoebida plus Glycostylida (suborders Dactylopodina, Stygamoebina; Vannellina) phylogenetically distinct from Centramoebida. Stygamoeba is sister to Dactylopodina. Himatismenida are either sister to Centramoebida or deeper branching. Discosea usually appear holophyletic (rarely paraphyletic). Paramoeba transcriptomes include prokinetoplastid Perkinsela-like endosymbiont sequences. Cunea, misidentified as Mayorella, is closer to Paramoeba than Vexillifera within holophyletic Dactylopodina. Taxon-rich site-heterogeneous rDNA trees confirm cutosan distinctiveness, allow improved conosan taxonomy, and reveal previous dictyostelid tree misrooting.}, }
@article {pmid26999164, year = {2016}, author = {Hayashi, A and Crombie, A and Lacey, E and Richardson, AJ and Vuong, D and Piggott, AM and Hallegraeff, G}, title = {Aspergillus Sydowii Marine Fungal Bloom in Australian Coastal Waters, Its Metabolites and Potential Impact on Symbiodinium Dinoflagellates.}, journal = {Marine drugs}, volume = {14}, number = {3}, pages = {}, pmid = {26999164}, issn = {1660-3397}, mesh = {Animals ; Aspergillus/*isolation &amp; purification/metabolism ; Australia ; *Coral Reefs ; Dinoflagellida/*microbiology ; Dust ; Fungi/isolation &amp; purification ; Secondary Metabolism ; Spores, Fungal/*isolation &amp; purification ; }, abstract = {Dust has been widely recognised as an important source of nutrients in the marine environment and as a vector for transporting pathogenic microorganisms. Disturbingly, in the wake of a dust storm event along the eastern Australian coast line in 2009, the Continuous Plankton Recorder collected masses of fungal spores and mycelia (~150,000 spores/m[3]) forming a floating raft that covered a coastal area equivalent to 25 times the surface of England. Cultured A. sydowii strains exhibited varying metabolite profiles, but all produced sydonic acid, a chemotaxonomic marker for A. sydowii. The Australian marine fungal strains share major metabolites and display comparable metabolic diversity to Australian terrestrial strains and to strains pathogenic to Caribbean coral. Secondary colonisation of the rafts by other fungi, including strains of Cladosporium, Penicillium and other Aspergillus species with distinct secondary metabolite profiles, was also encountered. Our bioassays revealed that the dust-derived marine fungal extracts and known A. sydowii metabolites such as sydowic acid, sydowinol and sydowinin A adversely affect photophysiological performance (Fv/Fm) of the coral reef dinoflagellate endosymbiont Symbiodinium. Different Symbiodinium clades exhibited varying sensitivities, mimicking sensitivity to coral bleaching phenomena. The detection of such large amounts of A. sydowii following this dust storm event has potential implications for the health of coral environments such as the Great Barrier Reef.}, }
@article {pmid26997548, year = {2016}, author = {Wang, GH and Jia, LY and Xiao, JH and Huang, DW}, title = {Discovery of a new Wolbachia supergroup in cave spider species and the lateral transfer of phage WO among distant hosts.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {41}, number = {}, pages = {1-7}, doi = {10.1016/j.meegid.2016.03.015}, pmid = {26997548}, issn = {1567-7257}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Bacteriophages/classification/*genetics ; Caves ; Chaperonin 60/genetics ; China ; Cytoskeletal Proteins/genetics ; Electron Transport Complex IV/genetics ; Gene Expression ; Gene Transfer, Horizontal ; Host Specificity ; *Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Spiders/*microbiology ; Symbiosis/physiology ; Wolbachia/classification/*genetics/virology ; }, abstract = {Wolbachia are widespread intracellular bacteria infecting the major classes of arthropods and some filarial nematodes. In arthropods, Wolbachia have evolved various intriguing reproductive manipulations, including cytoplasmic incompatibility, parthenogenesis, feminization, and male killing. Sixteen supergroups of Wolbachia have been identified, named A-Q (except G). Though Wolbachia present great diversity in arthropods, spiders, especially cave spiders, are still a poorly surveyed group of Wolbachia hosts. Here, we report a novel Wolbachia supergroup from nine Telema cave spiders (Araneae: Telemidae) based on five molecular markers (16S rRNA, ftsZ, gltA, groEL, and coxA). In addition, phage WO, which was previously reported only in Wolbachia supergroups A, B, and F, infects this new Wolbachia supergroup. We detected a 100% infection rate for phage WO and Wolbachia in Telema species. The phylogenetic trees of phage WO and Wolbachia are not congruent, which suggests that horizontal transfer of phage WO has occurred in these secluded species. Additionally, these data indicate Telema-Wolbachia-phage WO may be a good model for exploring the horizontal transfer history of WO among different host species.}, }
@article {pmid26996016, year = {2016}, author = {Vidkjær, NH and Jensen, KM and Gislum, R and Fomsgaard, IS}, title = {Profiling and Metabolism of Sterols in the Weaver Ant Genus Oecophylla.}, journal = {Natural product communications}, volume = {11}, number = {1}, pages = {39-43}, pmid = {26996016}, issn = {1934-578X}, mesh = {Animals ; Ants/*classification/*metabolism ; Gas Chromatography-Mass Spectrometry ; Molecular Structure ; Sterols/chemistry/*metabolism ; }, abstract = {Sterols are essential to insects because they are vital for many biochemical processes, nevertheless insects cannot synthesize sterols but have to acquire them through their diet. Studies of sterols in ants are sparse and here the sterols of the weaver ant genus Oecophylla are identified for the first time. The sterol profile and the dietary sterols provided to a laboratory Oecophylla longinoda colony were analyzed. Most sterols originated from the diet, except one, which was probably formed via dealkylation in the ants and two sterols of fungal origin, which likely originate from hitherto unidentified endosymbionts responsible for supplying these two compounds. The sterol profile of a wild Oecophylla smaragdina colony was also investigated. Remarkable qualitative similarities were established between the two species despite the differences in diet, species, and origin. This may reflect a common sterol need/aversion in the weaver ants. Additionally, each individual caste of both species displayed unique sterol profiles.}, }
@article {pmid26995349, year = {2016}, author = {Vanthournout, B and Hendrickx, F}, title = {Hidden suppression of sex ratio distortion suggests Red queen dynamics between Wolbachia and its dwarf spider host.}, journal = {Journal of evolutionary biology}, volume = {29}, number = {8}, pages = {1488-1494}, doi = {10.1111/jeb.12861}, pmid = {26995349}, issn = {1420-9101}, mesh = {Animals ; Female ; Reproduction ; *Sex Ratio ; *Spiders ; *Symbiosis ; *Wolbachia ; }, abstract = {Genetic conflict theory predicts strong selection for host nuclear factors suppressing endosymbiont effects on reproduction; however, evidence of these suppressors is currently scarce. This can either be caused by a low suppressor evolution rate, or if suppressors originate frequently, by rapid spread and concurrent masking of their activity by silencing the endosymbiont effect. To explore this, we use two populations of a dwarf spider with a similar female bias, caused by a Wolbachia infection. Using inter- and intrapopulation crosses, we determine that one of these populations demonstrates a higher suppressing capability towards Wolbachia despite having a similar population sex ratio. This suggests that spider and endosymbiont are locked in so-called red queen dynamics where, despite continuous coevolution, average fitness remains the same, hence hiding the presence of the suppressor. Finding different suppressor activity in populations that even lack phenotypic differentiation (i.e. similar sex ratio) further supports the hypothesis that suppressors originate often, but are often hidden by their own mode of action by countering endosymbiont effects.}, }
@article {pmid26994086, year = {2016}, author = {Boyd, BM and Allen, JM and Koga, R and Fukatsu, T and Sweet, AD and Johnson, KP and Reed, DL}, title = {Two Bacterial Genera, Sodalis and Rickettsia, Associated with the Seal Louse Proechinophthirus fluctus (Phthiraptera: Anoplura).}, journal = {Applied and environmental microbiology}, volume = {82}, number = {11}, pages = {3185-3197}, pmid = {26994086}, issn = {1098-5336}, mesh = {Animals ; Anoplura/*microbiology ; Enterobacteriaceae/genetics/*isolation &amp; purification/*physiology ; Fur Seals/parasitology ; Genome, Bacterial ; Rickettsia/*isolation &amp; purification ; *Symbiosis ; }, abstract = {UNLABELLED: Roughly 10% to 15% of insect species host heritable symbiotic bacteria known as endosymbionts. The lice parasitizing mammals rely on endosymbionts to provide essential vitamins absent in their blood meals. Here, we describe two bacterial associates from a louse, Proechinophthirus fluctus, which is an obligate ectoparasite of a marine mammal. One of these is a heritable endosymbiont that is not closely related to endosymbionts of other mammalian lice. Rather, it is more closely related to endosymbionts of the genus Sodalis associated with spittlebugs and feather-chewing bird lice. Localization and vertical transmission of this endosymbiont are also more similar to those of bird lice than to those of other mammalian lice. The endosymbiont genome appears to be degrading in symbiosis; however, it is considerably larger than the genomes of other mammalian louse endosymbionts. These patterns suggest the possibility that this Sodalis endosymbiont might be recently acquired, replacing a now-extinct, ancient endosymbiont. From the same lice, we also identified an abundant bacterium belonging to the genus Rickettsia that is closely related to Rickettsia ricketsii, a human pathogen vectored by ticks. No obvious masses of the Rickettsia bacterium were observed in louse tissues, nor did we find any evidence of vertical transmission, so the nature of its association remains unclear.<br><br>IMPORTANCE: Many insects are host to heritable symbiotic bacteria. These heritable bacteria have been identified from numerous species of parasitic lice. It appears that novel symbioses have formed between lice and bacteria many times, with new bacterial symbionts potentially replacing existing ones. However, little was known about the symbionts of lice parasitizing marine mammals. Here, we identified a heritable bacterial symbiont in lice parasitizing northern fur seals. This bacterial symbiont appears to have been recently acquired by the lice. The findings reported here provide insights into how new symbioses form and how this lifestyle is shaping the symbiont genome.}, }
@article {pmid26994075, year = {2016}, author = {Molloy, JC and Sommer, U and Viant, MR and Sinkins, SP}, title = {Wolbachia Modulates Lipid Metabolism in Aedes albopictus Mosquito Cells.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {10}, pages = {3109-3120}, pmid = {26994075}, issn = {1098-5336}, support = {MC_UU_12014/8/MRC_/Medical Research Council/United Kingdom ; BB/H016511/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; WT095121/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/*microbiology ; Animals ; Cell Line ; *Lipid Metabolism ; Lipids/analysis ; Mass Spectrometry ; *Symbiosis ; Wolbachia/growth &amp; development/metabolism/*physiology ; }, abstract = {UNLABELLED: Certain strains of the intracellular endosymbiont Wolbachia can strongly inhibit or block the transmission of viruses such as dengue virus (DENV) by Aedes mosquitoes, and the mechanisms responsible are still not well understood. Direct infusion and liquid chromatography-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry-based lipidomics analyses were conducted using Aedes albopictus Aa23 cells that were infected with the wMel and wMelPop strains of Wolbachia in comparison to uninfected Aa23-T cells. Substantial shifts in the cellular lipid profile were apparent in the presence of Wolbachia Most significantly, almost all sphingolipid classes were depleted, and some reductions in diacylglycerols and phosphatidylcholines were also observed. These lipid classes have previously been shown to be selectively enriched in DENV-infected mosquito cells, suggesting that Wolbachia may produce a cellular lipid environment that is antagonistic to viral replication. The data improve our understanding of the intracellular interactions between Wolbachia and mosquitoes.<br><br>IMPORTANCE: Mosquitoes transmit a variety of important viruses to humans, such as dengue virus and Zika virus. Certain strains of the intracellular bacterial genus called Wolbachia found in or introduced into mosquitoes can block the transmission of viruses, including dengue virus, but the mechanisms responsible are not well understood. We found substantial shifts in the cellular lipid profiles in the presence of these bacteria. Some lipid classes previously shown to be enriched in dengue virus-infected mosquito cells were depleted in the presence of Wolbachia, suggesting that Wolbachia may produce a cellular lipid environment that inhibits mosquito-borne viruses.}, }
@article {pmid26991800, year = {2016}, author = {Zhang, F and Li, Q and Chen, X and Huo, Y and Guo, H and Song, Z and Cui, F and Zhang, L and Fang, R}, title = {Roles of the Laodelphax striatellus Down syndrome cell adhesion molecule in Rice stripe virus infection of its insect vector.}, journal = {Insect molecular biology}, volume = {25}, number = {4}, pages = {413-421}, doi = {10.1111/imb.12226}, pmid = {26991800}, issn = {1365-2583}, mesh = {Amino Acid Sequence ; Animals ; Cloning, Molecular ; DNA, Complementary/genetics/metabolism ; Hemiptera/genetics/growth &amp; development/*microbiology/*physiology ; Insect Proteins/chemistry/*genetics/metabolism ; Insect Vectors/genetics/growth &amp; development/microbiology/physiology ; Neural Cell Adhesion Molecules/chemistry/*genetics/metabolism ; Nymph/genetics/growth &amp; development/microbiology/physiology ; Oryza/*virology ; Plant Diseases/*virology ; RNA, Messenger/genetics/metabolism ; Sequence Alignment ; Symbiosis ; Tenuivirus/*physiology ; Wolbachia/physiology ; }, abstract = {The arthropod Down syndrome cell adhesion molecule (Dscam) mediates pathogen-specific recognition via an extensive protein isoform repertoire produced by alternative splicing. To date, most studies have focused on the subsequent pathogen-specific immune response, and few have investigated the entry into cells of viruses or endosymbionts. In the present study, we cloned and characterized the cDNA of Laodelphax striatellus Dscam (LsDscam) and investigated the function of LsDscam in rice stripe virus (RSV) infection and the influence on the endosymbiont Wolbachia. LsDscam displayed a typical Dscam domain architecture, including 10 immunoglobulin (Ig) domains, six fibronectin type III domains, one transmembrane domain and a cytoplasmic tail. Alternative splicing occurred at the N-termini of the Ig2 and Ig3 domains, the complete Ig7 domain, the transmembrane domain and the C-terminus, comprising 10, 51, 35, two and two variable exons, respectively. Potentially LsDscam could encode at least 71 400 unique isoforms and 17 850 types of extracellular regions. LsDscam was expressed in various L. striatellus tissues. Knockdown of LsDscam mRNA via RNA interference decreased the titres of both RSV and Wolbachia, but did not change the numbers of the extracellular symbiotic bacterium Acinetobacter rhizosphaerae. Specific Dscam isoforms may play roles in enhancing the infection of vector-borne viruses or endosymbionts.}, }
@article {pmid26986533, year = {2015}, author = {Darienko, T and Pröschold, T}, title = {Genetic variability and taxonomic revision of the genus Auxenochlorella (Shihira et Krauss) Kalina et Puncocharova (Trebouxiophyceae, Chlorophyta).}, journal = {Journal of phycology}, volume = {51}, number = {2}, pages = {394-400}, doi = {10.1111/jpy.12279}, pmid = {26986533}, issn = {1529-8817}, abstract = {The monotypic genus Auxenochlorella with its type species A. protothecoides is so far only known from specific habitats such as the sap of several tree species. Several varieties were described according to physiological performances in culture on different organic substrates. However, two strains designated as Auxenochlorella were isolated from other habitats (an endosymbiont of Hydra viridis and an aquatic strain from an acidic volcano stream). We studied those isolates and compared them with six strains of Auxenochlorella belonging to different varieties. The integrative approach used in this study revealed that all strains showed similar morphology but differed in their SSU and ITS rDNA sequences. The Hydra endosymbiont formed a sister taxon to A. protothecoides, which included the varieties protothecoides, galactophila, and communis. The variety acidicola is not closely related to Auxenochlorella and represented its own lineage within the Trebouxiophyceae. In view of these results, we propose a new species of Auxenochlorella, A. symbiontica, for the Hydra symbiont, and a new genus Pumiliosphaera, with its type species, P. acidophila, for acidophilic strain. These results are supported by several compensatory base changes in the conserved region of ITS-2 and ITS-2 DNA barcodes.}, }
@article {pmid26983858, year = {2016}, author = {Zolfaghari Emameh, R and Barker, HR and Tolvanen, ME and Parkkila, S and Hytönen, VP}, title = {Horizontal transfer of β-carbonic anhydrase genes from prokaryotes to protozoans, insects, and nematodes.}, journal = {Parasites &amp; vectors}, volume = {9}, number = {}, pages = {152}, pmid = {26983858}, issn = {1756-3305}, mesh = {Animals ; Bacteria/*enzymology ; Carbonic Anhydrases/chemistry/*genetics ; Eukaryota/*enzymology ; *Gene Transfer, Horizontal ; *Interspersed Repetitive Sequences ; Models, Molecular ; Sequence Homology ; }, abstract = {BACKGROUND: Horizontal gene transfer (HGT) is a movement of genetic information occurring outside of normal mating activities. It is especially common between prokaryotic endosymbionts and their protozoan, insect, and nematode hosts. Although beta carbonic anhydrase (β-CA) plays a crucial role in metabolic functions of many living organisms, the origin of β-CA genes in eukaryotic species remains unclear.<br><br>METHODS: This study was conducted using phylogenetics, prediction of subcellular localization, and identification of &#x3b2;-CA, transposase, integrase, and resolvase genes on the MGEs of bacteria. We also structurally analyzed &#x3b2;-CAs from protozoans, insects, and nematodes and their putative prokaryotic common ancestors, by homology modelling.<br><br>RESULTS: Our investigations of a number of target genomes revealed that genes coding for transposase, integrase, resolvase, and conjugation complex proteins have been integrated with &#x3b2;-CA gene sequences on mobile genetic elements (MGEs) which have facilitated the mobility of &#x3b2;-CA genes from bacteria to protozoan, insect, and nematode species. The prokaryotic origin of protozoan, insect, and nematode &#x3b2;-CA enzymes is supported by phylogenetic analyses, prediction of subcellular localization, and homology modelling.<br><br>CONCLUSION: MGEs form a complete set of enzymatic tools, which are relevant to HGT of &#x3b2;-CA gene sequences from prokaryotes to protozoans, insects, and nematodes.}, }
@article {pmid26979151, year = {2016}, author = {Da Wang,  and Shi, X and Dai, P and Liu, D and Dai, X and Shang, Z and Ge, Z and Meng, X}, title = {Comparison of fitness traits and their plasticity on multiple plants for Sitobion avenae infected and cured of a secondary endosymbiont.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {23177}, pmid = {26979151}, issn = {2045-2322}, mesh = {Animals ; Aphids/microbiology/*physiology ; Avena/parasitology ; Enterobacteriaceae/*physiology ; Fertility ; Genes, Insect ; Genetic Fitness ; Larva/microbiology/physiology ; Plant Diseases/parasitology ; Secale/parasitology ; Symbiosis ; Triticum/parasitology ; }, abstract = {Regiella insecticola has been found to enhance the performance of host aphids on certain plants, but its functional role in adaptation of host aphids to plants is still controversial. Here we evaluate the impacts of R. insecticola infections on vital life-history traits of Sitobion avenae (Fabricius), and their underlying genetic variation and phenotypic plasticity on three plants. It was shown that effects of R. insecticola on S. avenae's fitness (i.e., developmental time and fecundity) were neutral on oat or wheat, but negative on rye. Infections of R. insecticola modified genetic variation that underlies S. avenae's life-history traits. This was demonstrated by comparing life-history trait heritabilities between aphid lines with and without R. insecticola. Moreover, there were enhanced negative genetic correlations between developmental time and fecundity for R. insecticola infected lines, and structural differences in G-matrices of life-history traits for the two types of aphid lines. In R. insecticola-infected aphid lines, there were increases in plasticities for developmental times of first and second instar nymphs and for fecundity, showing novel functional roles of bacterial symbionts in plant-insect interactions. The identified effects of R. insecticola infections could have significant implications for the ecology and evolution of its host populations in natural conditions.}, }
@article {pmid26976593, year = {2016}, author = {Méheust, R and Zelzion, E and Bhattacharya, D and Lopez, P and Bapteste, E}, title = {Protein networks identify novel symbiogenetic genes resulting from plastid endosymbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {13}, pages = {3579-3584}, pmid = {26976593}, issn = {1091-6490}, mesh = {Eukaryota/genetics ; *Evolution, Molecular ; Gene Fusion ; Genome, Plant ; Models, Genetic ; Multigene Family ; Oxidation-Reduction ; Photosynthesis/genetics ; Phylogeny ; Plants/genetics ; Plastids/*genetics ; Proteins/*genetics ; Sequence Homology, Amino Acid ; Symbiosis/*genetics ; }, abstract = {The integration of foreign genetic information is central to the evolution of eukaryotes, as has been demonstrated for the origin of the Calvin cycle and of the heme and carotenoid biosynthesis pathways in algae and plants. For photosynthetic lineages, this coordination involved three genomes of divergent phylogenetic origins (the nucleus, plastid, and mitochondrion). Major hurdles overcome by the ancestor of these lineages were harnessing the oxygen-evolving organelle, optimizing the use of light, and stabilizing the partnership between the plastid endosymbiont and host through retargeting of proteins to the nascent organelle. Here we used protein similarity networks that can disentangle reticulate gene histories to explore how these significant challenges were met. We discovered a previously hidden component of algal and plant nuclear genomes that originated from the plastid endosymbiont: symbiogenetic genes (S genes). These composite proteins, exclusive to photosynthetic eukaryotes, encode a cyanobacterium-derived domain fused to one of cyanobacterial or another prokaryotic origin and have emerged multiple, independent times during evolution. Transcriptome data demonstrate the existence and expression of S genes across a wide swath of algae and plants, and functional data indicate their involvement in tolerance to oxidative stress, phototropism, and adaptation to nitrogen limitation. Our research demonstrates the "recycling" of genetic information by photosynthetic eukaryotes to generate novel composite genes, many of which function in plastid maintenance.}, }
@article {pmid26969435, year = {2016}, author = {Shentu, XP and Li, DT and Xu, JF and She, L and Yu, XP}, title = {Effects of fungicides on the yeast-like symbiotes and their host, Nilaparvata lugens Stål (Hemiptera: Delphacidae).}, journal = {Pesticide biochemistry and physiology}, volume = {128}, number = {}, pages = {16-21}, doi = {10.1016/j.pestbp.2015.10.010}, pmid = {26969435}, issn = {1095-9939}, mesh = {Animals ; Fungicides, Industrial/*pharmacology ; Hemiptera/*drug effects/microbiology ; *Symbiosis ; }, abstract = {Yeast-like symbiotes (YLS) are endosymbionts that are closely related to the growth, development and reproduction of their host, the brown planthopper (BPH), Nilaparvata lugens Stål (Hemiptera: Delphacidae). In order to understand the relationship between the population of YLS in BPH cells and the survival rate of BPH, eight different fungicides were applied to rice plants infested by BPH, and the number of YLS and mortality of BPH were determined. Three of the fungicides, 27% toyocamycin &amp; tetramycin P &amp; tetrin B &amp; tetramycin A, 0.01% trichodermin, and 75% trifloxystrobin &amp; tebuconazole WG, were found to significantly reduce the number of YLS in BPH, subsequently causing a high mortality of BPH. The three fungicides were each mixed with a commonly used insecticide-imidacloprid, and the fungicide/insecticide mixtures could cause a marked reduction in YLS number in BPH, resulting in a significantly higher mortality of BPH than did the imidacloprid alone. The mixture of 27% toyocamycin &amp; tetramycin P &amp; tetrin B &amp; tetramycin A with imidacloprid showed the best inhibitory effect on BPH population. Our study demonstrated a high dependence of the BPH survival rate on the number of YLS harbored in BPH fat-body cells. It implies that using specific fungicides as an additive to imidacloprid for controlling BPH could be a novel way to enhance the efficacy of insecticide, minimizing the use of imidacloprid in paddy fields.}, }
@article {pmid26968115, year = {2016}, author = {Sorokan, AV and Ben'kovskaya, GV and Maksimov, IV}, title = {The influence of potato endophytes on Leptinotarsa decemlineata endosymbionts promotes mortality of the pest.}, journal = {Journal of invertebrate pathology}, volume = {136}, number = {}, pages = {65-67}, doi = {10.1016/j.jip.2016.03.006}, pmid = {26968115}, issn = {1096-0805}, mesh = {Animals ; Bacillus subtilis ; Coleoptera/*microbiology ; *Endophytes ; Host-Parasite Interactions/*physiology ; Pest Control, Biological ; Solanum tuberosum/*microbiology ; }, abstract = {Plants are exposed to pervasive attack by diverse attackers, such as pathogens and pests. But plants have their own endophytic microflora as well as the attacking insects. These microbiomes contact face to face in the nature. It has been found that the endophytic strain Bacillus subtilis 26D increases mortality of Colorado potato beetles, disturbing the development of insect microsymbionts Enterobacter ssp. and Acinetobacter ssp.}, }
@article {pmid26959231, year = {2016}, author = {Conaco, C and Tsoulfas, P and Sakarya, O and Dolan, A and Werren, J and Kosik, KS}, title = {Detection of Prokaryotic Genes in the Amphimedon queenslandica Genome.}, journal = {PloS one}, volume = {11}, number = {3}, pages = {e0151092}, pmid = {26959231}, issn = {1932-6203}, mesh = {Animals ; Evolution, Molecular ; Gene Transfer, Horizontal/genetics ; Genome/*genetics ; Phylogeny ; Porifera/*genetics ; }, abstract = {Horizontal gene transfer (HGT) is common between prokaryotes and phagotrophic eukaryotes. In metazoans, the scale and significance of HGT remains largely unexplored but is usually linked to a close association with parasites and endosymbionts. Marine sponges (Porifera), which host many microorganisms in their tissues and lack an isolated germ line, are potential carriers of genes transferred from prokaryotes. In this study, we identified a number of potential horizontally transferred genes within the genome of the sponge, Amphimedon queenslandica. We further identified homologs of some of these genes in other sponges. The transferred genes, most of which possess catalytic activity for carbohydrate or protein metabolism, have assimilated host genome characteristics and are actively expressed. The diversity of functions contributed by the horizontally transferred genes is likely an important factor in the adaptation and evolution of A. queenslandica. These findings highlight the potential importance of HGT on the success of sponges in diverse ecological niches.}, }
@article {pmid26943350, year = {2016}, author = {Michaud, C and Chupeau, C and Bech, N and Thierry, M and Sicard, M and Greve, P and Beltran-Bech, S}, title = {Isolation, characterization and PCR multiplexing of microsatellite loci for two sub-species of terrestrial isopod Porcellio dilatatus (Crustacea, Oniscidea).}, journal = {Genetica}, volume = {144}, number = {2}, pages = {223-228}, pmid = {26943350}, issn = {1573-6857}, mesh = {Animals ; Female ; Genetic Markers ; *Genetic Variation ; Genotype ; Isopoda/*genetics/microbiology ; Male ; *Microsatellite Repeats ; Phylogeny ; *Wolbachia ; }, abstract = {Several microsatellite markers have already been developed for different terrestrial isopod species such as Armadillidium vulgare, A. nasatum and Porcellionides pruinosus. In all these species, the endosymbiont Wolbachia has a feminizing effect that generates a female bias in sex ratio and reduces the number of reproductive males. Thus this can potentially decrease the genetic diversity of host populations. However, in some other isopod species, Wolbachia induces cytoplasmic incompatibility (CI); the most commonly described effect of Wolbachia in arthropods. The CI by rendering some crossings incompatible can reduce the gene flow and strengthen genetic differentiation between isopod populations. To date, the influence of Wolbachia inducing CI on population structure of terrestrial isopods has never been investigated. In this study, we developed 10 polymorphic microsatellite markers shared by two sub-species of Porcellio dilatatus. Crossings between the two sub-species are partially incompatible due to two CI-inducing Wolbachia strains. These new microsatellite markers will allow us to investigate the effect of CI on host genetic differentiation in this species complex.}, }
@article {pmid26941712, year = {2016}, author = {Correa, AM and Ainsworth, TD and Rosales, SM and Thurber, AR and Butler, CR and Vega Thurber, RL}, title = {Viral Outbreak in Corals Associated with an In Situ Bleaching Event: Atypical Herpes-Like Viruses and a New Megavirus Infecting Symbiodinium.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {127}, pmid = {26941712}, issn = {1664-302X}, abstract = {Previous studies of coral viruses have employed either microscopy or metagenomics, but few have attempted to comprehensively link the presence of a virus-like particle (VLP) to a genomic sequence. We conducted transmission electron microscopy imaging and virome analysis in tandem to characterize the most conspicuous viral types found within the dominant Pacific reef-building coral genus Acropora. Collections for this study inadvertently captured what we interpret as a natural outbreak of viral infection driven by aerial exposure of the reef flat coincident with heavy rainfall and concomitant mass bleaching. All experimental corals in this study had high titers of viral particles. Three of the dominant VLPs identified were observed in all tissue layers and budding out from the epidermis, including viruses that were ∼70, ∼120, and ∼150 nm in diameter; these VLPs all contained electron dense cores. These morphological traits are reminiscent of retroviruses, herpesviruses, and nucleocytoplasmic large DNA viruses (NCLDVs), respectively. Some 300-500 nm megavirus-like VLPs also were observed within and associated with dinoflagellate algal endosymbiont (Symbiodinium) cells. Abundant sequence similarities to a gammaretrovirus, herpesviruses, and members of the NCLDVs, based on a virome generated from five Acropora aspera colonies, corroborated these morphology-based identifications. Additionally sequence similarities to two diagnostic genes, a MutS and (based on re-annotation of sequences from another study) a DNA polymerase B gene, most closely resembled Pyramimonas orientalis virus, demonstrating the association of a cosmopolitan megavirus with Symbiodinium. We also identified several other virus-like particles in host tissues, along with sequences phylogenetically similar to circoviruses, phages, and filamentous viruses. This study suggests that viral outbreaks may be a common but previously undocumented component of natural bleaching events, particularly following repeated episodes of multiple environmental stressors.}, }
@article {pmid26934997, year = {2016}, author = {Sumrandee, C and Baimai, V and Trinachartvanit, W and Ahantarig, A}, title = {Molecular detection of Rickettsia, Anaplasma, Coxiella and Francisella bacteria in ticks collected from Artiodactyla in Thailand.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {5}, pages = {678-689}, doi = {10.1016/j.ttbdis.2016.02.015}, pmid = {26934997}, issn = {1877-9603}, mesh = {Anaplasma/genetics/*isolation &amp; purification ; Animals ; Artiodactyla/*parasitology ; Cluster Analysis ; Coxiella/genetics/*isolation &amp; purification ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Francisella/genetics/*isolation &amp; purification ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/*isolation &amp; purification ; Sequence Analysis, DNA ; Thailand ; Ticks/*microbiology ; }, abstract = {A total of 79 ticks collected from Sambar deer (Cervus unicolor), Barking deer (Muntiacus muntjak) and Wild boar (Sus scrofa) were examined by PCR for the presence of Rickettsia, Anaplasma, Coxiella, and Francisella bacteria. Of the 79 ticks, 13% tested positive for Rickettsia, 15% tested positive for Anaplasma, 4% tested positive for Coxiella, and 3% tested positive for Francisella. Interestingly, triple infection with Anaplasma, Rickettsia and Francisella was determined in a Dermacentor auratus tick. Moreover, another triple infection with Rickettsia, Anaplasma, and Coxiella was found in a Haemaphysalis lagrangei tick. Double infection of Rickettsia with Coxiella was also detected in another H. lagrangei tick. From the phylogenetic analyses, we found a Rickettsia sp. with a close evolutionary relationship to Rickettsia bellii in the H. lagrangei tick. We also found the first evidence of a Rickettsia sp. that is closely related to Rickettsia tamurae in Rhipicephalus (Boophilus) microplus ticks from Thailand. H. lagrangei and Haemaphysalis obesa ticks collected from Sambar deer tested positive for Anaplasma species form the same clade with Anaplasma bovis. In contrast, other H. lagrangei ticks collected from Sambar deer and D. auratus ticks collected from Wild boar were also reported for the first time to be infected with an Anaplasma species that is closely related to Anaplasma platys. The phylogenetic analysis of the 16S rRNA gene of Coxiella bacteria revealed that Coxiella symbionts from H. lagrangei formed a distinctly different lineage from Coxiella burnetii (a human pathogen). Additionally, Francisella bacteria identified in D. auratus ticks were found to be distantly related to a group of pathogenic Francisella species. The identification of these bacteria in several feeding ticks suggests the risk of various emerging tick-borne diseases and endosymbionts in humans, wildlife, and domestic animals in Thailand.}, }
@article {pmid26920842, year = {2016}, author = {Suzuki, S and Hirakawa, Y and Kofuji, R and Sugita, M and Ishida, KI}, title = {Plastid genome sequences of Gymnochlora stellata, Lotharella vacuolata, and Partenskyella glossopodia reveal remarkable structural conservation among chlorarachniophyte species.}, journal = {Journal of plant research}, volume = {129}, number = {4}, pages = {581-590}, pmid = {26920842}, issn = {1618-0860}, mesh = {Base Sequence ; Chlorophyta/*genetics ; Conserved Sequence/*genetics ; *Genome, Plastid ; Introns/genetics ; Likelihood Functions ; Phylogeny ; Species Specificity ; }, abstract = {Chlorarachniophyte algae have complex plastids acquired by the uptake of a green algal endosymbiont, and this event is called secondary endosymbiosis. Interestingly, the plastids possess a relict endosymbiont nucleus, referred to as the nucleomorph, in the intermembrane space, and the nucleomorphs contain an extremely reduced and compacted genome in comparison with green algal nuclear genomes. Therefore, chlorarachniophyte plastids consist of two endosymbiotically derived genomes, i.e., the plastid and nucleomorph genomes. To date, complete nucleomorph genomes have been sequenced in four different species, whereas plastid genomes have been reported in only two species in chlorarachniophytes. To gain further insight into the evolution of endosymbiotic genomes in chlorarachniophytes, we newly sequenced the plastid genomes of three species, Gymnochlora stellata, Lotharella vacuolata, and Partenskyella glossopodia. Our findings reveal that chlorarachniophyte plastid genomes are highly conserved in size, gene content, and gene order among species, but their nucleomorph genomes are divergent in such features. Accordingly, the current architecture of the plastid genomes of chlorarachniophytes evolved in a common ancestor, and changed very little during their subsequent diversification. Furthermore, our phylogenetic analyses using multiple plastid genes suggest that chlorarachniophyte plastids are derived from a green algal lineage that is closely related to Bryopsidales in the Ulvophyceae group.}, }
@article {pmid26920389, year = {2016}, author = {Ohshima, S and Sato, Y and Fujimura, R and Takashima, Y and Hamada, M and Nishizawa, T and Narisawa, K and Ohta, H}, title = {Mycoavidus cysteinexigens gen. nov., sp. nov., an endohyphal bacterium isolated from a soil isolate of the fungus Mortierella elongata.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {66}, number = {5}, pages = {2052-2057}, doi = {10.1099/ijsem.0.000990}, pmid = {26920389}, issn = {1466-5034}, mesh = {Bacterial Typing Techniques ; Base Composition ; Burkholderiaceae/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Japan ; *Mortierella ; Phospholipids/chemistry ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Soil Microbiology ; Ubiquinone/chemistry ; }, abstract = {An endohyphal bacterium (strain B1-EBT) living in association with the fungus Mortierella elongata FMR23-6 I-B1 was isolated from a fungal cell homogenate and studied for its taxonomic allocation. Cells were Gram-stain-negative, rod-shaped, non-spore-forming, non-motile, and negative for oxidase and catalase. Strain B1-EBT required cysteine for growth and grew at temperatures between 4 and 35 °C. A comparative analysis of 16S rRNA gene sequences revealed that strain B1-EBT forms a distinct clade in the family Burkholderiaceae, encompassing a group of endosymbionts associated with several soil isolates of M. elongata. The most closely related genus is 'Candidatus Glomeribacter gigasporarum', an endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. The major cellular fatty acids of strain B1-EBT were C16 : 0, summed feature 3 (C16 : 1ω7c and C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c or C18 : 1ω6c). Ubiquinone Q-8 was the only quinone detected. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unknown aminophospholipid and two unknown aminolipids. The DNA G+C content was 49.8 mol%. On the basis of phenotypic, chemotaxonomic, and phylogenetic characteristics, strain B1-EBT represents a novel genus and novel species in the family Burkholderiaceae, for which the name Mycoavidus cysteinexigens gen. nov., sp. nov. is proposed. The type strain is B1-EBT (= JCM 30646T = LMG 28693T = NBRC 110909T).}, }
@article {pmid26914459, year = {2016}, author = {Ikeda-Ohtsubo, W and Strassert, JF and Köhler, T and Mikaelyan, A and Gregor, I and McHardy, AC and Tringe, SG and Hugenholtz, P and Radek, R and Brune, A}, title = {'Candidatus Adiutrix intracellularis', an endosymbiont of termite gut flagellates, is the first representative of a deep-branching clade of Deltaproteobacteria and a putative homoacetogen.}, journal = {Environmental microbiology}, volume = {18}, number = {8}, pages = {2548-2564}, doi = {10.1111/1462-2920.13234}, pmid = {26914459}, issn = {1462-2920}, mesh = {Animals ; Deltaproteobacteria/*classification/genetics/*isolation &amp; purification ; Desulfovibrio/genetics ; Formate Dehydrogenases/genetics ; Gene Transfer, Horizontal/genetics ; Hypermastigia/*microbiology ; In Situ Hybridization, Fluorescence ; Intestines/*microbiology ; Isoptera/*parasitology ; Nitrogen Fixation/genetics ; Phylogeny ; Symbiosis ; }, abstract = {Termite gut flagellates are typically colonized by specific bacterial symbionts. Here we describe the phylogeny, ultrastructure and subcellular location of 'Candidatus Adiutrix intracellularis', an intracellular symbiont of Trichonympha collaris in the termite Zootermopsis nevadensis. It represents a novel, deep-branching clade of uncultured Deltaproteobacteria widely distributed in intestinal tracts of termites and cockroaches. Fluorescence in situ hybridization and transmission electron microscopy localized the endosymbiont near hydrogenosomes in the posterior part and near the ectosymbiont 'Candidatus Desulfovibrio trichonymphae' in the anterior part of the host cell. The draft genome of 'Ca. Adiutrix intracellularis' obtained from a metagenomic library revealed the presence of a complete gene set encoding the Wood-Ljungdahl pathway, including two homologs of fdhF encoding hydrogenase-linked formate dehydrogenases (FDHH) and all other components of the recently described hydrogen-dependent carbon dioxide reductase (HDCR) complex, which substantiates previous claims that the symbiont is capable of reductive acetogenesis from CO2 and H2 . The close phylogenetic relationship between the HDCR components and their homologs in homoacetogenic Firmicutes and Spirochaetes suggests that the deltaproteobacterium acquired the capacity for homoacetogenesis via lateral gene transfer. The presence of genes for nitrogen fixation and the biosynthesis of amino acids and cofactors indicate the nutritional nature of the symbiosis.}, }
@article {pmid26912763, year = {2016}, author = {Marks, LR and Dodd, H and Russo, TA and Berenson, CS}, title = {Burkholderia ginsengisoli bacteraemia: emergence of a novel pathogen.}, journal = {BMJ case reports}, volume = {2016}, number = {}, pages = {}, pmid = {26912763}, issn = {1757-790X}, mesh = {Adult ; Anti-Bacterial Agents/therapeutic use ; Bacteremia/*drug therapy/microbiology ; Burkholderia/genetics/*isolation &amp; purification ; Burkholderia Infections/*diagnosis/drug therapy ; Crohn Disease/*microbiology ; DNA, Bacterial/genetics ; Food Microbiology ; Humans ; Male ; Sequence Analysis, DNA ; Treatment Outcome ; }, abstract = {Burkholderia ginsengisoli is a non-pathogenic Gram-negative bacterium that ordinarily serves as a plant endosymbiont. We report the first case of human infection with B. ginsengisoli presenting as bacteraemia in a young man with severe Crohn's disease. Definitive identification of the pathogen could not be accomplished with conventional techniques and required DNA sequencing. The bacteraemia may have been related to ingestion of organic vegetables and compromised gastrointestinal mucosa, coupled with treatment with tumour necrosis factor α inhibitors. Although there are no standard antibiotics to treat this pathogen, we devised a successful treatment regimen.}, }
@article {pmid26912375, year = {2016}, author = {Pennington, MJ and Prager, SM and Walton, WE and Trumble, JT}, title = {Culex quinquefasciatus larval microbiomes vary with instar and exposure to common wastewater contaminants.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {21969}, pmid = {26912375}, issn = {2045-2322}, mesh = {Acetaminophen/pharmacology ; Animals ; Anti-Bacterial Agents/pharmacology ; Bacteria/drug effects/genetics/*isolation &amp; purification ; Caffeine/pharmacology ; Culex/growth &amp; development/*microbiology ; DNA, Bacterial/chemistry/genetics/metabolism ; Hormones/pharmacology ; Larva/drug effects/microbiology ; *Microbiota ; Polymerase Chain Reaction ; Principal Component Analysis ; Sequence Analysis, DNA ; Waste Water/*chemistry ; Water Pollutants, Chemical/pharmacology ; }, abstract = {Like many insects, mosquitoes, rely on endosymbionts to grow and develop. These can be acquired from the environment. We used next generation 454 pyrosequencing to discern the whole-body microbiome of the mosquito species Culex quinquefasciatus in various larval stadia and following exposure to common pharmaceutical and personal care products (PPCPs) found in wastewater. PPCP treatments included environmentally-relevant concentrations; 1) a combination of common antibiotics, 2) a combination of mammalian hormones, 3) a mixture of the antibiotic and hormone treatments plus acetaminophen and caffeine and, 4) an untreated control. Within control groups, the predominant families of bacterial symbionts change with each larval instar despite consistent diets and rearing conditions. This trend was also seen in hormone treatments but not in the antibiotic or the mixture treatments. Richness and evenness were reduced in both antibiotic and mixture treatments, suggesting that antibiotics remove certain bacteria or inhibit them from increasing to proportions seen in the control treatment. Interestingly, the mixture treatments had greater richness and evenness compared to antibiotic alone treatments, possibly due to the other contaminants facilitating growth of different bacteria. These findings illuminate the complexity of the microbiome of C. quinquefasciatus and may have implications for more effective control strategies.}, }
@article {pmid26903964, year = {2016}, author = {Rodriguez, IB and Lin, S and Ho, J and Ho, TY}, title = {Effects of Trace Metal Concentrations on the Growth of the Coral Endosymbiont Symbiodinium kawagutii.}, journal = {Frontiers in microbiology}, volume = {7}, number = {}, pages = {82}, pmid = {26903964}, issn = {1664-302X}, abstract = {Symbiodinium is an indispensable endosymbiont in corals and the most important primary producer in coral reef ecosystems. During the past decades, coral bleaching attributed to the disruption of the symbiosis has frequently occurred resulting in reduction of coral reef coverage globally. Growth and proliferation of corals require some specific trace metals that are essential components of pertinent biochemical processes, such as in photosynthetic systems and electron transport chains. In addition, trace metals are vital in the survival of corals against oxidative stress because these metals serve as enzymatic cofactors in antioxidative defense mechanisms. The basic knowledge about trace metal requirements of Symbiodinium is lacking. Here we show that the requirement of Symbiodinium kawagutii for antioxidant-associated trace metals exhibits the following order: Fe >> Cu/Zn/Mn >> Ni. In growth media with Cu, Zn, Mn, and varying Fe concentrations, we observed that Cu, Zn, and Mn cellular quotas were inversely related to Fe concentrations. In the absence of Cu, Zn, and Mn, growth rates increased with increasing inorganic Fe concentrations up to 1250 pM, indicating the relatively high Fe requirement for Symbiodinium growth and potential functional complementarity of these metals. These results demonstrate the relative importance of trace metals to sustain Symbiodinium growth and a potential metal inter replacement strategy in Symbiodinium to ensure survival of coral reefs in an oligotrophic and stressful environment.}, }
@article {pmid26902077, year = {2016}, author = {Whitman, WB}, title = {Modest proposals to expand the type material for naming of prokaryotes.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {66}, number = {5}, pages = {2108-2112}, doi = {10.1099/ijsem.0.000980}, pmid = {26902077}, issn = {1466-5034}, mesh = {Bacteria/classification ; Classification/*methods ; *Terminology as Topic ; }, abstract = {Gene sequences are herein proposed to be suitable type material for the description of prokaryotic species. This proposal follows from the principles described in the International Code of Nomenclature of Prokaryotes. This simple change in the Code will allow for the stability of naming of Candidatus taxa, endosymbionts and uncultivated prokaryotes and will meet an important need within microbiology. In addition, modern molecular techniques allow the identification of genera even when the species remain obscure. The Code should be modified to allow gene sequences to serve as the type material for genera in the absence of described species. This simple change will unite the nomenclature of the cultured and uncultured prokaryotes into a single, robust system.}, }
@article {pmid26901622, year = {2016}, author = {Bohacsova, M and Mediannikov, O and Kazimirova, M and Raoult, D and Sekeyova, Z}, title = {Arsenophonus nasoniae and Rickettsiae Infection of Ixodes ricinus Due to Parasitic Wasp Ixodiphagus hookeri.}, journal = {PloS one}, volume = {11}, number = {2}, pages = {e0149950}, pmid = {26901622}, issn = {1932-6203}, mesh = {Animals ; Ixodes/*microbiology ; Ixodidae/microbiology ; Male ; Nymph/microbiology ; Rickettsia/*physiology ; Wasps/*microbiology ; }, abstract = {Arsenophonus nasoniae, a male-killing endosymbiont of chalcid wasps, was recently detected in several hard tick species. Following the hypothesis that its presence in ticks may not be linked to the direct occurrence of bacteria in tick's organs, we identified A. nasoniae in wasps emerging from parasitised nymphs. We confirmed that 28.1% of Ixodiphagus hookeri wasps parasitizing Ixodes ricinus ticks were infected by A. nasoniae. Moreover, in examined I. ricinus nymphs, A. nasoniae was detected only in those, which were parasitized by the wasp. However, in part of the adult wasps as well as in some ticks that contained wasp's DNA, we did not confirm A. nasoniae. We also found, that in spite of reported male-killing, some newly emerged adult wasp males were also infected by A. nasoniae. Additionally, we amplified the DNA of Rickettsia helvetica and Rickettsia monacensis (known to be Ixodes ricinus-associated bacteria) in adult parasitoid wasps. This may be related either with the digested bacterial DNA in wasp body lumen or with a role of wasps in circulation of rickettsiae among tick vectors.}, }
@article {pmid26896674, year = {2016}, author = {Wu, LH and Hoffmann, AA and Thomson, LJ}, title = {Taiwanese Trichogramma of Asian Corn Borer: Morphology, ITS-2 rDNA Characterization, and Natural Wolbachia Infection.}, journal = {Journal of insect science (Online)}, volume = {16}, number = {1}, pages = {}, pmid = {26896674}, issn = {1536-2442}, mesh = {Animals ; Base Sequence ; DNA, Ribosomal Spacer/*genetics ; Moths/*parasitology ; Pest Control, Biological ; Phylogeny ; Taiwan ; Wasps/anatomy &amp; histology/genetics/*microbiology ; Wolbachia/genetics/*physiology ; }, abstract = {Egg parasitoids of the genus Trichogramma are natural enemies of many lepidopteran borers in agricultural areas around the world. It is important to identify the correct species and ideally focus on endemic Trichogramma for pest control in particular crops. In this study, Trichogramma wasps were collected from parasitized eggs of Asian corn borer in Southwestern Taiwan. Three Trichogramma species, Trichogramma ostriniae Pang and Chen, Trichogramma chilonis Ishii, and T. sp. y, were identified based on morphology and the nucleotide sequence of the internal transcribed spacer 2 (ITS-2) region of rDNA. Although T. ostriniae and T. sp. y appear to be morphologically similar, ITS-2 identity between these two taxa is only 89%. Surprisingly, a commercially released Trichogramma colony thought to be T. chilonis possessed 99% identity (ITS-2) with the field T. sp. y individuals. This suggests past contamination leading to subsitution of the laboratory-reared T. chilonis colony by T. sp. y. Natural populations of all three Trichogramma species were found to be infected by a single Wolbachia strain which was identified using a wsp gene sequence.}, }
@article {pmid26895868, year = {2016}, author = {Dolatabadi, S and Scherlach, K and Figge, M and Hertweck, C and Dijksterhuis, J and Menken, SB and de Hoog, GS}, title = {Food preparation with mucoralean fungi: A potential biosafety issue?.}, journal = {Fungal biology}, volume = {120}, number = {3}, pages = {393-401}, doi = {10.1016/j.funbio.2015.12.001}, pmid = {26895868}, issn = {1878-6146}, mesh = {Burkholderiaceae/classification/genetics/*isolation &amp; purification ; Chromatography, High Pressure Liquid ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Food Handling/*methods ; Food Microbiology ; *Food Safety ; Microscopy ; Mucorales/isolation &amp; purification/*metabolism ; Mucormycosis/microbiology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Soil Microbiology ; *Symbiosis ; }, abstract = {Mucorales have been used for production of fermented food in Asia and Africa since time immemorial. Particularly Rhizopus species are rapidly growing, active producers of lipases and proteases and occur naturally during the first stages of soybean fermentation. Two biosafety issues have been raised in recent literature: (1) pathogenicity, Rhizopus species being prevalent opportunists causing erosive infections in severely compromised patients, and (2) toxicity, strains harbouring endosymbiotic Burkholderia producing toxic secondary metabolites. At the molecular level, based on different gene markers, species identity was found between strains used for food processing and clinical strains. In this study, we screened for bacterial symbionts in 64 Rhizopus strains by light microscopy, 16S rRNA sequencing, and HPLC. Seven strains (11 %) carried bacteria identified as Burkholderia rhizoxinica and Burkholderia endofungorum, and an unknown Burkholderia species. The Burkholderia isolates proved to be able to produce toxic rhizoxins. Strains with endosymbionts originated from food, soil, and a clinical source, and thus their presence could not be linked to particular habitats. The presence of Burkholderia in Rhizopus producing toxins could not be excluded as a potential risk for human health. In contrast, given the type of diseases caused by Rhizopus species, we regard the practical risk of infection via the food industry as negligible.}, }
@article {pmid26894821, year = {2016}, author = {Castelli, M and Lanzoni, O and Rossi, L and Potekhin, A and Schrallhammer, M and Petroni, G}, title = {Evaluation of Enrichment Protocols for Bacterial Endosymbionts of Ciliates by Real-Time PCR.}, journal = {Current microbiology}, volume = {72}, number = {6}, pages = {723-732}, pmid = {26894821}, issn = {1432-0991}, mesh = {Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Bacterial Typing Techniques/*methods ; Biodiversity ; Ciliophora/*microbiology/physiology ; DNA, Bacterial/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Real-Time Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {Large-scale studies on obligate bacterial endosymbionts may frequently require preliminary purification and enrichment protocols, which are often elaborate to set up and to evaluate, especially if the host organism is a protist. The purpose of this study was to develop a real-time PCR-based strategy and employ it for assessing two of such enrichment protocols for Holospora caryophila, hosted by the ciliate Paramecium. Four SSU rRNA gene-targeted real-time PCR assays were designed, which allowed to compare the amount of H. caryophila to other organisms, namely the host, its food bacterium (Raoultella planticola), and free-living bacteria present in the culture medium. By the use of the real-time PCR assays in combination, it was possible to conclude that the "cell fractionation" protocol was quite successful in the enrichment of the symbiont, while the "Percoll gradient" protocol will need further refinements to be fully repeatable. The proposed approach has the potential to facilitate and encourage future studies on the yet underexplored field of bacterial endosymbionts of ciliates and other protists. It can also find valuable applications for experimental questions other than those tested, such as fast and precise assessment of symbiont abundance in natural populations and comparison among multiple coexisting symbionts.}, }
@article {pmid26893424, year = {2016}, author = {Mehari, YT and Arivett, BA and Farone, AL and Gunderson, JH and Farone, MB}, title = {Draft Genome Sequences of Two Novel Amoeba-Resistant Intranuclear Bacteria, "Candidatus Berkiella cookevillensis" and "Candidatus Berkiella aquae".}, journal = {Genome announcements}, volume = {4}, number = {1}, pages = {}, pmid = {26893424}, issn = {2169-8287}, abstract = {"Candidatus Berkiella cookevillensis" and "Candidatus Berkiella aquae" are obligate intranuclear endosymbionts of freshwater amoebae. Here, we present the draft genome sequences of these two bacteria, with total sizes of 2,990,361 bp and 3,626,027 bp, respectively.}, }
@article {pmid26888293, year = {2016}, author = {Tanifuji, G and Archibald, JM and Hashimoto, T}, title = {Comparative genomics of mitochondria in chlorarachniophyte algae: endosymbiotic gene transfer and organellar genome dynamics.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {21016}, pmid = {26888293}, issn = {2045-2322}, support = {MOP-115141//Canadian Institutes of Health Research/Canada ; }, mesh = {Cercozoa/*genetics ; DNA, Mitochondrial/*genetics ; DNA, Protozoan/*genetics ; *Gene Transfer, Horizontal ; *Genome, Mitochondrial ; *Genome, Protozoan ; Species Specificity ; *Symbiosis ; }, abstract = {Chlorarachniophyte algae possess four DNA-containing compartments per cell, the nucleus, mitochondrion, plastid and nucleomorph, the latter being a relic nucleus derived from a secondary endosymbiont. While the evolutionary dynamics of plastid and nucleomorph genomes have been investigated, a comparative investigation of mitochondrial genomes (mtDNAs) has not been carried out. We have sequenced the complete mtDNA of Lotharella oceanica and compared it to that of another chlorarachniophyte, Bigelowiella natans. The linear mtDNA of L. oceanica is 36.7 kbp in size and contains 35 protein genes, three rRNAs and 24 tRNAs. The codons GUG and UUG appear to be capable of acting as initiation codons in the chlorarachniophyte mtDNAs, in addition to AUG. Rpl16, rps4 and atp8 genes are missing in L.oceanica mtDNA, despite being present in B. natans mtDNA. We searched for, and found, mitochondrial rpl16 and rps4 genes with spliceosomal introns in the L. oceanica nuclear genome, indicating that mitochondrion-to-host-nucleus gene transfer occurred after the divergence of these two genera. Despite being of similar size and coding capacity, the level of synteny between L. oceanica and B. natans mtDNA is low, suggesting frequent rearrangements. Overall, our results suggest that chlorarachniophyte mtDNAs are more evolutionarily dynamic than their plastid counterparts.}, }
@article {pmid26885833, year = {2016}, author = {Wu, W and Tran, W and Taatjes, CA and Alonso-Gutierrez, J and Lee, TS and Gladden, JM}, title = {Rapid Discovery and Functional Characterization of Terpene Synthases from Four Endophytic Xylariaceae.}, journal = {PloS one}, volume = {11}, number = {2}, pages = {e0146983}, pmid = {26885833}, issn = {1932-6203}, mesh = {Alkyl and Aryl Transferases/chemistry/*genetics ; Amino Acid Sequence ; Endophytes/*enzymology/*genetics ; Escherichia coli/metabolism ; Genes, Fungal ; Molecular Sequence Data ; Multigene Family ; Phylogeny ; Sequence Alignment ; Terminology as Topic ; Terpenes/chemistry/metabolism ; Xylariales/*enzymology/*genetics ; }, abstract = {Endophytic fungi are ubiquitous plant endosymbionts that establish complex and poorly understood relationships with their host organisms. Many endophytic fungi are known to produce a wide spectrum of volatile organic compounds (VOCs) with potential energy applications, which have been described as "mycodiesel". Many of these mycodiesel hydrocarbons are terpenes, a chemically diverse class of compounds produced by many plants, fungi, and bacteria. Due to their high energy densities, terpenes, such as pinene and bisabolene, are actively being investigated as potential "drop-in" biofuels for replacing diesel and aviation fuel. In this study, we rapidly discovered and characterized 26 terpene synthases (TPSs) derived from four endophytic fungi known to produce mycodiesel hydrocarbons. The TPS genes were expressed in an E. coli strain harboring a heterologous mevalonate pathway designed to enhance terpene production, and their product profiles were determined using Solid Phase Micro-Extraction (SPME) and GC-MS. Out of the 26 TPS's profiled, 12 TPS's were functional, with the majority of them exhibiting both monoterpene and sesquiterpene synthase activity.}, }
@article {pmid26884158, year = {2016}, author = {Traverse, CC and Ochman, H}, title = {Conserved rates and patterns of transcription errors across bacterial growth states and lifestyles.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {12}, pages = {3311-3316}, pmid = {26884158}, issn = {1091-6490}, support = {R01 GM108657/GM/NIGMS NIH HHS/United States ; R35 GM118038/GM/NIGMS NIH HHS/United States ; R01GM108657/GM/NIGMS NIH HHS/United States ; }, mesh = {Escherichia coli/*genetics/*growth &amp; development ; Escherichia coli Proteins/chemistry ; Genes, Bacterial ; Symbiosis ; *Transcription, Genetic ; }, abstract = {Errors that occur during transcription have received much less attention than the mutations that occur in DNA because transcription errors are not heritable and usually result in a very limited number of altered proteins. However, transcription error rates are typically several orders of magnitude higher than the mutation rate. Also, individual transcripts can be translated multiple times, so a single error can have substantial effects on the pool of proteins. Transcription errors can also contribute to cellular noise, thereby influencing cell survival under stressful conditions, such as starvation or antibiotic stress. Implementing a method that captures transcription errors genome-wide, we measured the rates and spectra of transcription errors in Escherichia coli and in endosymbionts for which mutation and/or substitution rates are greatly elevated over those of E. coli Under all tested conditions, across all species, and even for different categories of RNA sequences (mRNA and rRNAs), there were no significant differences in rates of transcription errors, which ranged from 2.3 × 10(-5) per nucleotide in mRNA of the endosymbiont Buchnera aphidicola to 5.2 × 10(-5) per nucleotide in rRNA of the endosymbiont Carsonella ruddii The similarity of transcription error rates in these bacterial endosymbionts to that in E. coli (4.63 × 10(-5) per nucleotide) is all the more surprising given that genomic erosion has resulted in the loss of transcription fidelity factors in both Buchnera and Carsonella.}, }
@article {pmid26882265, year = {2016}, author = {Gall, CA and Reif, KE and Scoles, GA and Mason, KL and Mousel, M and Noh, SM and Brayton, KA}, title = {The bacterial microbiome of Dermacentor andersoni ticks influences pathogen susceptibility.}, journal = {The ISME journal}, volume = {10}, number = {8}, pages = {1846-1855}, pmid = {26882265}, issn = {1751-7370}, support = {T32 GM008336/GM/NIGMS NIH HHS/United States ; T32 AI007025/AI/NIAID NIH HHS/United States ; R21 AI093524/AI/NIAID NIH HHS/United States ; R01 AI044005/AI/NIAID NIH HHS/United States ; R37 AI044005/AI/NIAID NIH HHS/United States ; }, mesh = {Anaplasma marginale/*pathogenicity ; Animals ; Dermacentor/*microbiology/physiology ; Francisella/*pathogenicity ; Humans ; *Microbiota ; Rickettsia/*growth &amp; development ; Symbiosis ; }, abstract = {Ticks are of medical importance owing to their ability to transmit pathogens to humans and animals. The Rocky Mountain wood tick, Dermacentor andersoni, is a vector of a number of pathogens, including Anaplasma marginale, which is the most widespread tick-borne pathogen of livestock. Although ticks host pathogenic bacteria, they also harbor bacterial endosymbionts that have a role in tick physiology, survival, as well as pathogen acquisition and transmission. The goal of this study was to characterize the bacterial microbiome and examine the impact of microbiome disruption on pathogen susceptibility. The bacterial microbiome of two populations of D. andersoni with historically different susceptibilities to A. marginale was characterized. In this study, the microbiome was disrupted and then ticks were exposed to A. marginale or Francisella novicida to determine whether the microbiome correlated with pathogen susceptibility. Our study showed that an increase in proportion and quantity of Rickettsia bellii in the microbiome was negatively correlated to A. marginale levels in ticks. Furthermore, a decrease in Francisella endosymbionts was associated with lower F. novicida infection levels, demonstrating a positive pathogen-endosymbiont relationship. We demonstrate that endosymbionts and pathogens have varying interactions, and suggest that microbiome manipulation may provide a possible method for biocontrol by decreasing pathogen susceptibility of ticks.}, }
@article {pmid26882089, year = {2016}, author = {Detree, C and Chabenat, A and Lallier, FH and Satoh, N and Shoguchi, E and Tanguy, A and Mary, J}, title = {Multiple I-Type Lysozymes in the Hydrothermal Vent Mussel Bathymodiolus azoricus and Their Role in Symbiotic Plasticity.}, journal = {PloS one}, volume = {11}, number = {2}, pages = {e0148988}, pmid = {26882089}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/biosynthesis/genetics/*metabolism ; Bivalvia/microbiology/*physiology ; Chlorobi/classification/enzymology/genetics/*physiology ; Ecosystem ; Gene Expression Regulation, Bacterial ; Gills/microbiology/physiology ; Gram-Negative Bacteria/classification/enzymology/genetics/*physiology ; Hydrothermal Vents ; Isoenzymes/biosynthesis/genetics/metabolism ; Methylococcaceae/classification/enzymology/genetics/*physiology ; Molecular Sequence Data ; Muramidase/biosynthesis/genetics/*metabolism ; Phylogeny ; Sequence Alignment ; Symbiosis/genetics ; }, abstract = {The aim of this study was first to identify lysozymes paralogs in the deep sea mussel Bathymodiolus azoricus then to measure their relative expression or activity in different tissue or conditions. B. azoricus is a bivalve that lives close to hydrothermal chimney in the Mid-Atlantic Ridge (MAR). They harbour in specialized gill cells two types of endosymbiont (gram-bacteria): sulphide oxidizing bacteria (SOX) and methanotrophic bacteria (MOX). This association is thought to be ruled by specific mechanism or actors of regulation to deal with the presence of symbiont but these mechanisms are still poorly understood. Here, we focused on the implication of lysozyme, a bactericidal enzyme, in this endosymbiosis. The relative expression of Ba-lysozymes paralogs and the global anti-microbial activity, were measured in natural population (Lucky Strike--1700 m, Mid-Atlantic Ridge), and in in situ experimental conditions. B. azoricus individuals were moved away from the hydrothermal fluid to induce a loss of symbiont. Then after 6 days some mussels were brought back to the mussel bed to induce a re-acquisition of symbiotic bacteria. Results show the presence of 6 paralogs in B. azoricus. In absence of symbionts, 3 paralogs are up-regulated while others are not differentially expressed. Moreover the global activity of lysozyme is increasing with the loss of symbiont. All together these results suggest that lysozyme may play a crucial role in symbiont regulation.}, }
@article {pmid26878871, year = {2016}, author = {Duncan, RP and Feng, H and Nguyen, DM and Wilson, AC}, title = {Gene Family Expansions in Aphids Maintained by Endosymbiotic and Nonsymbiotic Traits.}, journal = {Genome biology and evolution}, volume = {8}, number = {3}, pages = {753-764}, pmid = {26878871}, issn = {1759-6653}, mesh = {Amino Acid Transport Systems/biosynthesis/*genetics ; Animals ; Aphids/*genetics/microbiology ; Bacteria/*genetics ; Evolution, Molecular ; Gene Expression Regulation ; Phylogeny ; Symbiosis/*genetics ; Transcriptome/genetics ; }, abstract = {Facilitating the evolution of new gene functions, gene duplication is a major mechanism driving evolutionary innovation. Gene family expansions relevant to host/symbiont interactions are increasingly being discovered in eukaryotes that host endosymbiotic microbes. Such discoveries entice speculation that gene duplication facilitates the evolution of novel, endosymbiotic relationships. Here, using a comparative transcriptomic approach combined with differential gene expression analysis, we investigate the importance of endosymbiosis in retention of amino acid transporter paralogs in aphid genomes. To pinpoint the timing of amino acid transporter duplications we inferred gene phylogenies for five aphid species and three outgroups. We found that while some duplications arose in the aphid common ancestor concurrent with endosymbiont acquisition, others predate aphid divergence from related insects without intracellular symbionts, and still others appeared during aphid diversification. Interestingly, several aphid-specific paralogs have conserved enriched expression in bacteriocytes, the insect cells that host primary symbionts. Conserved bacteriocyte enrichment suggests that the transporters were recruited to the aphid/endosymbiont interface in the aphid common ancestor, consistent with a role for gene duplication in facilitating the evolution of endosymbiosis in aphids. In contrast, the temporal variability of amino acid transporter duplication indicates that endosymbiosis is not the only trait driving selection for retention of amino acid transporter paralogs in sap-feeding insects. This study cautions against simplistic interpretations of the role of gene family expansion in the evolution of novel host/symbiont interactions by further highlighting that multiple complex factors maintain gene family paralogs in the genomes of eukaryotes that host endosymbiotic microbes.}, }
@article {pmid26876638, year = {2016}, author = {Che, Y and Wang, D and Shi, Y and Du, X and Zhao, Y and Lo, N and Wang, Z}, title = {A global molecular phylogeny and timescale of evolution for Cryptocercus woodroaches.}, journal = {Molecular phylogenetics and evolution}, volume = {98}, number = {}, pages = {201-209}, doi = {10.1016/j.ympev.2016.02.005}, pmid = {26876638}, issn = {1095-9513}, mesh = {Animals ; Asia ; Cockroaches/*classification/*genetics ; *Evolution, Molecular ; Fossils ; Isoptera/genetics ; Male ; North America ; *Phylogeny ; Phylogeography ; RNA, Ribosomal/genetics ; Time Factors ; }, abstract = {Cryptocercus is a genus of sub-social wood-feeding cockroaches that represents the sister group to the eusocial termites. We generated mitochondrial (12S+16S rRNA, COII), nuclear (28S rRNA) and Blattbacterium endosymbiont (16S+23S rRNA) sequence data for 8 new Chinese species, and combined these with previously available data to undertake the most extensive analysis of phylogenetic relationships within the genus to date. As expected, phylogenetic relationships among Blattabacterium strains were found to be congruent with those of their hosts. Three major clades were found to exist in Asian populations, one representing taxa from the Hengduan mountains in Southwestern China, a second including taxa from Russia, Korea, Northeastern China, and Yunnan in the Hengduan Mountains, and a third including taxa from the Qinling Mountains and Daba Mountains in Central China. A molecular dating analysis using 7 termite fossils to calibrate the molecular clock indicated that the divergence of American and Asian Cryptocercus occurred 55.09Ma (41.55-72.28Ma 95% CI), and that the radiations of American and Asian taxa occurred 28.48Ma (20.83-37.95Ma 95% CI) and 20.97Ma (15.78-27.21Ma 95% CI) respectively. Reconstruction of ancestral geographic distributions using S-DIVA suggested Cryptocercus was originally distributed across both continents, as opposed to ancestral migration of Cryptocercus from one continent to the other. The last common ancestor of Asian Cryptocercus was inferred to have existed in Central China. An examination of male chromosome numbers in Asian Cryptocercus showed that diploid numbers vary from 2n=15 to 2n=41, and indicates the presence of eight new species. Our study represents the most comprehensive phylogenetic and biogeographic study yet performed for this important group of cockroaches.}, }
@article {pmid26873314, year = {2016}, author = {Greiman, SE and Rikihisa, Y and Cain, J and Vaughan, JA and Tkach, VV}, title = {Germs within Worms: Localization of Neorickettsia sp. within Life Cycle Stages of the Digenean Plagiorchis elegans.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {8}, pages = {2356-2362}, pmid = {26873314}, issn = {1098-5336}, support = {R15 AI092622/AI/NIAID NIH HHS/United States ; R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animal Structures/microbiology ; Animals ; Helminths/growth &amp; development/*microbiology ; Life Cycle Stages ; Microscopy, Fluorescence ; Neorickettsia/*isolation &amp; purification/*physiology ; *Symbiosis ; Trematoda/growth &amp; development/*microbiology ; }, abstract = {Neorickettsia spp. are bacterial endosymbionts of parasitic flukes (Digenea) that also have the potential to infect and cause disease (e.g., Sennetsu fever) in the vertebrate hosts of the fluke. One of the largest gaps in our knowledge of Neorickettsia biology is the very limited information available regarding the localization of the bacterial endosymbiont within its digenean host. In this study, we used indirect immunofluorescence microscopy to visualize Neorickettsia sp. within several life cycle stages of the digenean Plagiorchis elegans Individual sporocysts, cercariae, metacercariae, and adults of P. elegans naturally infected with Neorickettsia sp. were obtained from our laboratory-maintained life cycle, embedded, sectioned, and prepared for indirect immunofluorescence microscopy using anti-Neorickettsia risticiihorse serum as the primary antibody. Neorickettsiasp. was found within the tegument of sporocysts, throughout cercarial embryos (germ balls) and fully formed cercariae (within the sporocysts), throughout metacercariae, and within the tegument, parenchyma, vitellaria, uteri, testes, cirrus sacs, and eggs of adults. Interestingly, Neorickettsia sp. was not found within the ovarian tissue. This suggests that vertical transmission of Neorickettsia within adult digeneans occurs via the incorporation of infected vitelline cells into the egg rather than direct infection of the ooplasm of the oocyte, as has been described for other bacterial endosymbionts of invertebrates (e.g.,Rickettsia and Wolbachia).}, }
@article {pmid26865969, year = {2016}, author = {Enders, LS and Miller, NJ}, title = {Stress-induced changes in abundance differ among obligate and facultative endosymbionts of the soybean aphid.}, journal = {Ecology and evolution}, volume = {6}, number = {3}, pages = {818-829}, pmid = {26865969}, issn = {2045-7758}, abstract = {Bacterial endosymbionts can drive evolutionary novelty by conferring adaptive benefits under adverse environmental conditions. Among aphid species there is growing evidence that symbionts influence tolerance to various forms of stress. However, the extent to which stress inflicted on the aphid host has cascading effects on symbiont community dynamics remains poorly understood. Here we simultaneously quantified the effect of host-plant induced and xenobiotic stress on soybean aphid (Aphis glycines) fitness and relative abundance of its three bacterial symbionts. Exposure to soybean defensive stress (Rag1 gene) and a neurotoxic insecticide (thiamethoxam) substantially reduced aphid composite fitness (survival × reproduction) by 74 ± 10% and 92 ± 2%, respectively, which in turn induced distinctive changes in the endosymbiont microbiota. When challenged by host-plant defenses a 1.4-fold reduction in abundance of the obligate symbiont Buchnera was observed across four aphid clonal lines. Among facultative symbionts of Rag1-stressed aphids, Wolbachia abundance increased twofold and Arsenophonus decreased 1.5-fold. A similar pattern was observed under xenobiotic stress, with Buchnera and Arsenophonus titers decreasing (1.3-fold) and Wolbachia increasing (1.5-fold). Furthermore, variation in aphid virulence to Rag1 was positively correlated with changes in Arsenophonus titers, but not Wolbachia or Buchnera. A single Arsenophonus multi-locus genotype was found among aphid clonal lines, indicating strain diversity is not primarily responsible for correlated host-symbiont stress levels. Overall, our results demonstrate the nature of aphid symbioses can significantly affect the outcome of interactions under stress and suggests general changes in the microbiome can occur across multiple stress types.}, }
@article {pmid26862076, year = {2016}, author = {Shokal, U and Yadav, S and Atri, J and Accetta, J and Kenney, E and Banks, K and Katakam, A and Jaenike, J and Eleftherianos, I}, title = {Effects of co-occurring Wolbachia and Spiroplasma endosymbionts on the Drosophila immune response against insect pathogenic and non-pathogenic bacteria.}, journal = {BMC microbiology}, volume = {16}, number = {}, pages = {16}, pmid = {26862076}, issn = {1471-2180}, mesh = {Animals ; Drosophila Proteins/genetics/immunology ; Drosophila melanogaster/*immunology/*microbiology/physiology ; Female ; Male ; Spiroplasma/*physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Symbiotic interactions between microbes and animals are common in nature. Symbiotic organisms are particularly common in insects and, in some cases, they may protect their hosts from pathogenic infections. Wolbachia and Spiroplasma endosymbionts naturally inhabit various insects including Drosophila melanogaster fruit flies. Therefore, this symbiotic association is considered an excellent model to investigate whether endosymbiotic bacteria participate in host immune processes against certain pathogens. Here we have investigated whether the presence of Wolbachia alone or together with Spiroplasma endosymbionts in D. melanogaster adult flies affects the immune response against the virulent insect pathogen Photorhabdus luminescens and against non-pathogenic Escherichia coli bacteria.<br><br>RESULTS: We found that D. melanogaster flies carrying no endosymbionts, those carrying both Wolbachia and Spiroplasma, and those containing Wolbachia only had similar survival rates after infection with P. luminescens or Escherichia coli bacteria. However, flies carrying both endosymbionts or Wolbachia only contained higher numbers of E. coli cells at early time-points post infection than flies without endosymbiotic bacteria. Interestingly, flies containing Wolbachia only had lower titers of this endosymbiont upon infection with the pathogen P. luminescens than uninfected flies of the same strain. We further found that the presence of Wolbachia and Spiroplasma in D. melanogaster up-regulated certain immune-related genes upon infection with P. luminescens or E. coli bacteria, but it failed to alter the phagocytic ability of the flies toward E. coli inactive bioparticles.<br><br>CONCLUSION: Our results suggest that the presence of Wolbachia and Spiroplasma in D. melanogaster can modulate immune signaling against infection by certain insect pathogenic and non-pathogenic bacteria. Results from such studies are important for understanding the molecular basis of the interactions between endosymbiotic bacteria of insects and exogenous microbes.}, }
@article {pmid26859724, year = {2016}, author = {Keroack, CD and Wurster, JI and Decker, CG and Williams, KM and Slatko, BE and Foster, JM and Williams, SA}, title = {Absence of the Filarial Endosymbiont Wolbachia in Seal Heartworm (Acanthocheilonema spirocauda) but Evidence of Ancient Lateral Gene Transfer.}, journal = {The Journal of parasitology}, volume = {102}, number = {3}, pages = {312-318}, doi = {10.1645/15-872}, pmid = {26859724}, issn = {1937-2345}, mesh = {Acanthocheilonema/genetics/*microbiology ; Acanthocheilonemiasis/microbiology/parasitology/*veterinary ; Animals ; Biological Evolution ; Blotting, Western ; DNA Barcoding, Taxonomic ; DNA, Helminth/chemistry/isolation &amp; purification ; Female ; *Gene Transfer, Horizontal/physiology ; Hydroxymethylbilane Synthase/genetics ; Phoca/*parasitology ; Phylogeny ; Polymerase Chain Reaction/methods ; Pseudogenes ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*genetics/immunology/physiology ; }, abstract = {The symbiotic relationship of Wolbachia spp. was first observed in insects and subsequently in many parasitic filarial nematodes. This bacterium is believed to provide metabolic and developmental assistance to filarial parasitic nematodes, although the exact nature of this relationship remains to be fully elucidated. While Wolbachia is present in most filarial nematodes in the family Onchocercidae, it is absent in several disparate species such as the human parasite Loa loa . All tested members of the genus Acanthocheilonema, such as Acanthocheilonema viteae, have been shown to lack Wolbachia. Consistent with this, we show that Wolbachia is absent from the seal heartworm (Acanthocheilonema spirocauda), but lateral gene transfer (LGT) of DNA sequences between Wolbachia and A. spirocauda has occurred, indicating a past evolutionary association. Seal heartworm is an important pathogen of phocid seals and understanding its basic biology is essential for conservation of the host. The findings presented here may allow for the development of future treatments or diagnostics for the disease and also aid in clarification of the complicated nematode-Wolbachia relationship.}, }
@article {pmid26851594, year = {2016}, author = {Rana, AK and Kushwaha, S and Singh, PK and Misra-Bhattacharya, S}, title = {Immunological evaluation of an rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi.}, journal = {Comparative immunology, microbiology and infectious diseases}, volume = {44}, number = {}, pages = {41-47}, doi = {10.1016/j.cimid.2015.12.001}, pmid = {26851594}, issn = {1878-1667}, mesh = {Animals ; Brugia malayi/physiology ; Cytokines/genetics ; Filariasis/prevention &amp; control ; Immunity, Cellular ; Immunity, Humoral ; Interferon-gamma/genetics ; Interleukin-10/genetics ; Interleukin-4/genetics ; Methyltransferases/genetics/*immunology/isolation &amp; purification ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins/immunology/isolation &amp; purification ; Symbiosis ; Wolbachia/*enzymology/*immunology ; }, abstract = {Wolbachia is a wonderful anti-filarial target with many of its enzymes and surface proteins (WSPs) representing potential drug targets and vaccine candidates. Here we report on the immunologic response of a drug target, rsmD-like rRNA methyltransferase from Wolbachia endosymbiont of Brugia malayi. The recombinant protein generated both humoral and cell-mediated response in BALB/c mice but compromised its immunity. The humoral response was transient and endured barely for six months in mice with or without B. Malayi challenge. In splenocytes of mice, the key humoral immunity mediating cytokine IL4 was lowered (IL4↓) while IFNγ, the major cytokine mediating cellular immunity was decreased along with upregulation of IL10 cytokine (IFNγ↓, IL10↑). The finding here indicates that the enzyme has low immunogenicity and triggers lowering of cytokine level in BALB/c mice. Interestingly the overall immune profile can be summed up with equivalent response generated by WSP or whole Wolbachia.}, }
@article {pmid26850304, year = {2016}, author = {Zhang, YC and Cao, WJ and Zhong, LR and Godfray, HCJ and Liu, XD}, title = {Host Plant Determines the Population Size of an Obligate Symbiont (Buchnera aphidicola) in Aphids.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {8}, pages = {2336-2346}, pmid = {26850304}, issn = {1098-5336}, mesh = {Animals ; Aphids/*microbiology ; *Bacterial Load ; Buchnera/*growth &amp; development ; Plants/*parasitology ; *Population Density ; Real-Time Polymerase Chain Reaction ; }, abstract = {Buchnera aphidicolais an obligate endosymbiont that provides aphids with several essential nutrients. Though much is known about aphid-Buchnera interactions, the effect of the host plant on Buchnera population size remains unclear. Here we used quantitative PCR (qPCR) techniques to explore the effects of the host plant on Buchnera densities in the cotton-melon aphid, Aphis gossypii Buchneratiters were significantly higher in populations that had been reared on cucumber for over 10 years than in populations maintained on cotton for a similar length of time. Aphids collected in the wild from hibiscus and zucchini harbored more Buchnera symbionts than those collected from cucumber and cotton. The effect of aphid genotype on the population size of Buchnera depended on the host plant upon which they fed. When aphids from populations maintained on cucumber or cotton were transferred to novel host plants, host survival and Buchnera population size fluctuated markedly for the first two generations before becoming relatively stable in the third and later generations. Host plant extracts from cucumber, pumpkin, zucchini, and cowpea added to artificial diets led to a significant increase in Buchnera titers in the aphids from the population reared on cotton, while plant extracts from cotton and zucchini led to a decrease in Buchnera titers in the aphids reared on cucumber. Gossypol, a secondary metabolite from cotton, suppressed Buchnera populations in populations from both cotton and cucumber, while cucurbitacin from cucurbit plants led to higher densities. Together, the results suggest that host plants influence Buchnera population processes and that this may provide phenotypic plasticity in host plant use for clonal aphids.}, }
@article {pmid26848744, year = {2016}, author = {Han, T and Lee, W and Lee, S and Park, IG and Park, H}, title = {Reassessment of Species Diversity of the Subfamily Denticollinae (Coleoptera: Elateridae) through DNA Barcoding.}, journal = {PloS one}, volume = {11}, number = {2}, pages = {e0148602}, pmid = {26848744}, issn = {1932-6203}, mesh = {Animals ; Coleoptera/anatomy &amp; histology/*genetics ; *DNA Barcoding, Taxonomic ; Electron Transport Complex IV/chemistry/genetics ; Gene Library ; *Genetic Variation ; Likelihood Functions ; Species Specificity ; }, abstract = {The subfamily Denticollinae is a taxonomically diverse group in the family Elateridae. Denticollinae includes many morphologically similar species and crop pests, as well as many undescribed species at each local fauna. To construct a rapid and reliable identification system for this subfamily, the effectiveness of molecular species identification was assessed based on 421 cytochrome c oxidase subunit I (COI) sequences of 84 morphologically identified species. Among the 84 morphospecies, molecular species identification of 60 species (71.4%) was consistent with their morphological identifications. Six cryptic and/or pseudocryptic species with large genetic divergence (>5%) were confirmed by their sympatric or allopatric distributions. However, 18 species, including a subspecies, had ambiguous genetic distances and shared overlapping intra- and interspecific genetic distances (range: 2.12%-3.67%) suggesting incomplete lineage sorting, introgression of mitochondrial genome, or affection by endosymbionts, such as Wolbachia infection, between species and simple genetic variation within species. In this study, we propose a conservative threshold of 3.6% for convenient molecular operational taxonomic unit (MOTU) identification in the subfamily Denticollinae based on the results of pairwise genetic distances analyses using neighbor-joining, mothur, Automatic Barcode Gap Discovery analysis, and tree-based species delimitation by Poisson Tree Processes analysis. Using the 3.6% threshold, we identified 87 MOTUs and found 8 MOTUs in the interval between 2.5% to 3.5%. Evaluation of MOTUs identified in this range requires integrative species delimitation, including review of morphological and ecological differences as well as sensitive genetic markers. From this study, we confirmed that COI sequence is useful for reassessing species diversity for polymorphic and polytypic species occurring in sympatric and allopatric distributions, and for a single species having an extensively large habitat.}, }
@article {pmid26846713, year = {2016}, author = {Schuler, H and Köppler, K and Daxböck-Horvath, S and Rasool, B and Krumböck, S and Schwarz, D and Hoffmeister, TS and Schlick-Steiner, BC and Steiner, FM and Telschow, A and Stauffer, C and Arthofer, W and Riegler, M}, title = {The hitchhiker's guide to Europe: the infection dynamics of an ongoing Wolbachia invasion and mitochondrial selective sweep in Rhagoletis cerasi.}, journal = {Molecular ecology}, volume = {25}, number = {7}, pages = {1595-1609}, pmid = {26846713}, issn = {1365-294X}, support = {I 2604/FWF_/Austrian Science Fund FWF/Austria ; J 3527/FWF_/Austrian Science Fund FWF/Austria ; P 26749/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Bayes Theorem ; DNA, Mitochondrial/*genetics ; Disease Transmission, Infectious ; Europe ; *Evolution, Molecular ; Gene Frequency ; *Genetics, Population ; Genome, Insect ; Genotype ; Germany ; Haplotypes ; Microsatellite Repeats ; Models, Genetic ; Selection, Genetic ; Sequence Analysis, DNA ; Spatio-Temporal Analysis ; Tephritidae/*genetics/*microbiology ; Wolbachia/*genetics ; }, abstract = {Wolbachia is a maternally inherited and ubiquitous endosymbiont of insects. It can hijack host reproduction by manipulations such as cytoplasmic incompatibility (CI) to enhance vertical transmission. Horizontal transmission of Wolbachia can also result in the colonization of new mitochondrial lineages. In this study, we present a 15-year-long survey of Wolbachia in the cherry fruit fly Rhagoletis cerasi across Europe and the spatiotemporal distribution of two prevalent strains, wCer1 and wCer2, and associated mitochondrial haplotypes in Germany. Across most of Europe, populations consisted of either 100% singly (wCer1) infected individuals with haplotype HT1, or 100% doubly (wCer1&amp;2) infected individuals with haplotype HT2, differentiated only by a single nucleotide polymorphism. In central Germany, singly infected populations were surrounded by transitional populations, consisting of both singly and doubly infected individuals, sandwiched between populations fixed for wCer1&amp;2. Populations with fixed infection status showed perfect association of infection and mitochondria, suggesting a recent CI-driven selective sweep of wCer2 linked with HT2. Spatial analysis revealed a range expansion for wCer2 and a large transition zone in which wCer2 splashes appeared to coalesce into doubly infected populations. Unexpectedly, the transition zone contained a large proportion (22%) of wCer1&amp;2 individuals with HT1, suggesting frequent intraspecific horizontal transmission. However, this horizontal transmission did not break the strict association between infection types and haplotypes in populations outside the transition zone, suggesting that this horizontally acquired Wolbachia infection may be transient. Our study provides new insights into the rarely studied Wolbachia invasion dynamics in field populations.}, }
@article {pmid26846216, year = {2016}, author = {Chu, CC and Gill, TA and Hoffmann, M and Pelz-Stelinski, KS}, title = {Inter-Population Variability of Endosymbiont Densities in the Asian Citrus Psyllid (Diaphorina citri Kuwayama).}, journal = {Microbial ecology}, volume = {71}, number = {4}, pages = {999-1007}, pmid = {26846216}, issn = {1432-184X}, mesh = {Alphaproteobacteria/*classification/genetics ; Animals ; Bacterial Load ; Citrus/microbiology ; Female ; Florida ; Helicobacter/classification/genetics ; Hemiptera/*microbiology ; Male ; North America ; Real-Time Polymerase Chain Reaction ; Symbiosis ; Wolbachia/*classification/genetics ; }, abstract = {The Asian citrus psyllid (Diaphorina citri Kuwayama) is an insect pest capable of transmitting Candidatus Liberibacter asiaticus (CLas), the causal agent of citrus greening in North America. D. citri also harbors three endosymbionts, Wolbachia, Candidatus Carsonella ruddii, and Candidatus Profftella armatura, which may influence D. citri physiology and fitness. Although genomic researches on these bacteria have been conducted, much remains unclear regarding their ecology and inter-population variability in D. citri. The present work examined the densities of each endosymbiont in adult D. citri sampled from different populations using quantitative PCR. Under field conditions, the densities of all three endosymbionts positively correlated with each other, and they are associated with D. citri gender and locality. In addition, the infection density of CLas also varied across populations. Although an analysis pooling D. citri from different populations showed that CLas-infected individuals tended to have lower endosymbiont densities compared to uninfected individuals, the difference was not significant when the population was included as a factor in the analysis, suggesting that other population-specific factors may have stronger effects on endosymbiont densities. To determine whether there is a genetic basis to the density differences, endosymbiont densities between aged CLas-negative females of two D. citri populations reared under standardized laboratory conditions were compared. Results suggested that inter-population variability in Wolbachia infection density is associated with the genotypes of the endosymbiont or the host. Findings from this work could facilitate understanding of D. citri-bacterial associations that may benefit the development of approaches for managing citrus greening, such as prevention of CLas transmission.}, }
@article {pmid26840490, year = {2016}, author = {Pittis, AA and Gabaldón, T}, title = {Late acquisition of mitochondria by a host with chimaeric prokaryotic ancestry.}, journal = {Nature}, volume = {531}, number = {7592}, pages = {101-104}, pmid = {26840490}, issn = {1476-4687}, support = {310325/ERC_/European Research Council/International ; }, mesh = {Eukaryotic Cells/*cytology/metabolism ; Genes, Bacterial/*genetics ; Genes, Mitochondrial/*genetics ; Genomics ; Mitochondria/*genetics/metabolism ; Mitochondrial Proteins/genetics/metabolism ; Models, Biological ; *Phylogeny ; Prokaryotic Cells/*cytology/metabolism ; Symbiosis/*genetics ; }, abstract = {The origin of eukaryotes stands as a major conundrum in biology. Current evidence indicates that the last eukaryotic common ancestor already possessed many eukaryotic hallmarks, including a complex subcellular organization. In addition, the lack of evolutionary intermediates challenges the elucidation of the relative order of emergence of eukaryotic traits. Mitochondria are ubiquitous organelles derived from an alphaproteobacterial endosymbiont. Different hypotheses disagree on whether mitochondria were acquired early or late during eukaryogenesis. Similarly, the nature and complexity of the receiving host are debated, with models ranging from a simple prokaryotic host to an already complex proto-eukaryote. Most competing scenarios can be roughly grouped into either mito-early, which consider the driving force of eukaryogenesis to be mitochondrial endosymbiosis into a simple host, or mito-late, which postulate that a significant complexity predated mitochondrial endosymbiosis. Here we provide evidence for late mitochondrial endosymbiosis. We use phylogenomics to directly test whether proto-mitochondrial proteins were acquired earlier or later than other proteins of the last eukaryotic common ancestor. We find that last eukaryotic common ancestor protein families of alphaproteobacterial ancestry and of mitochondrial localization show the shortest phylogenetic distances to their closest prokaryotic relatives, compared with proteins of different prokaryotic origin or cellular localization. Altogether, our results shed new light on a long-standing question and provide compelling support for the late acquisition of mitochondria into a host that already had a proteome of chimaeric phylogenetic origin. We argue that mitochondrial endosymbiosis was one of the ultimate steps in eukaryogenesis and that it provided the definitive selective advantage to mitochondria-bearing eukaryotes over less complex forms.}, }
@article {pmid26836631, year = {2016}, author = {Rosenfeld, JA and Reeves, D and Brugler, MR and Narechania, A and Simon, S and Durrett, R and Foox, J and Shianna, K and Schatz, MC and Gandara, J and Afshinnekoo, E and Lam, ET and Hastie, AR and Chan, S and Cao, H and Saghbini, M and Kentsis, A and Planet, PJ and Kholodovych, V and Tessler, M and Baker, R and DeSalle, R and Sorkin, LN and Kolokotronis, SO and Siddall, ME and Amato, G and Mason, CE}, title = {Genome assembly and geospatial phylogenomics of the bed bug Cimex lectularius.}, journal = {Nature communications}, volume = {7}, number = {}, pages = {10164}, pmid = {26836631}, issn = {2041-1723}, support = {F31 GM111053/GM/NIGMS NIH HHS/United States ; R01NS076465/NS/NINDS NIH HHS/United States ; P30 CA008748/CA/NCI NIH HHS/United States ; T32 GM083937/GM/NIGMS NIH HHS/United States ; F31GM111053/GM/NIGMS NIH HHS/United States ; R01 GM092706/GM/NIGMS NIH HHS/United States ; R01 NS076465/NS/NINDS NIH HHS/United States ; 1T32GM083937/GM/NIGMS NIH HHS/United States ; R01GM092706/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bedbugs/*genetics ; Blood ; Chromosome Mapping ; Eating ; Female ; Gene Expression Profiling ; *Gene Expression Regulation, Developmental ; Humans ; Life Cycle Stages/*genetics ; Male ; Models, Molecular ; Phylogeny ; Sequence Analysis, RNA ; }, abstract = {The common bed bug (Cimex lectularius) has been a persistent pest of humans for thousands of years, yet the genetic basis of the bed bug's basic biology and adaptation to dense human environments is largely unknown. Here we report the assembly, annotation and phylogenetic mapping of the 697.9-Mb Cimex lectularius genome, with an N50 of 971 kb, using both long and short read technologies. A RNA-seq time course across all five developmental stages and male and female adults generated 36,985 coding and noncoding gene models. The most pronounced change in gene expression during the life cycle occurs after feeding on human blood and included genes from the Wolbachia endosymbiont, which shows a simultaneous and coordinated host/commensal response to haematophagous activity. These data provide a rich genetic resource for mapping activity and density of C. lectularius across human hosts and cities, which can help track, manage and control bed bug infestations.}, }
@article {pmid26833622, year = {2016}, author = {Moeller, HV and Peltomaa, E and Johnson, MD and Neubert, MG}, title = {Acquired phototrophy stabilises coexistence and shapes intrinsic dynamics of an intraguild predator and its prey.}, journal = {Ecology letters}, volume = {19}, number = {4}, pages = {393-402}, doi = {10.1111/ele.12572}, pmid = {26833622}, issn = {1461-0248}, mesh = {Animals ; Aquatic Organisms/*physiology ; Ciliophora/*physiology ; Cryptophyta/*physiology ; *Ecosystem ; Food Chain ; Light ; *Models, Biological ; Phototrophic Processes/*physiology ; Phytoplankton/*physiology ; }, abstract = {In marine ecosystems, acquired phototrophs - organisms that obtain their photosynthetic ability by hosting endosymbionts or stealing plastids from their prey - are omnipresent. Such taxa function as intraguild predators yet depend on their prey to periodically obtain chloroplasts. We present a new theory for the effects of acquired phototrophy on community dynamics by analysing a mathematical model of this predator-prey interaction and experimentally verifying its predictions with a laboratory model system. We show that acquired phototrophy stabilises coexistence, but that the nature of this coexistence exhibits a 'paradox of enrichment': as light increases, the coexistence between the acquired phototroph and its prey transitions from a stable equilibrium to boom-bust cycles whose amplitude increases with light availability. In contrast, heterotrophs and mixotrophic acquired phototrophs (that obtain < 30% of their carbon from photosynthesis) do not exhibit such cycles. This prediction matches field observations, in which only strict (> 95% of carbon from photosynthesis) acquired phototrophs form blooms.}, }
@article {pmid26832644, year = {2016}, author = {Rouhrazi, K and Khodakaramian, G and Velázquez, E}, title = {Phylogenetic diversity of rhizobial species and symbiovars nodulating Phaseolus vulgaris in Iran.}, journal = {FEMS microbiology letters}, volume = {363}, number = {5}, pages = {fnw024}, doi = {10.1093/femsle/fnw024}, pmid = {26832644}, issn = {1574-6968}, mesh = {Bacterial Proteins/genetics ; Base Sequence ; DNA, Bacterial/genetics ; Iran ; Membrane Proteins/genetics ; N-Acetylglucosaminyltransferases/genetics ; Phaseolus/*microbiology ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Rec A Recombinases/genetics ; Rhizobium leguminosarum/*classification/*genetics/growth &amp; development ; Rhizobium tropici/classification/*genetics/growth &amp; development ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Soil Microbiology ; Symbiosis ; }, abstract = {The phylogenetic diversity of 29 rhizobial strains nodulating Phaseolus vulgaris in Iran was analysed on the basis of their core and symbiotic genes. These strains displayed five 16S rRNA-RFLP patterns and belong to eight ERIC-PCR clusters. The phylogenetic analyses of 16S rRNA, recA and atpD core genes allowed the identification of several strains as Rhizobium sophoriradicis, R. leguminosarum, R. tropici and Pararhizobium giardinii, whereas other strains represented a new phylogenetic lineage related to R. vallis. These strains and those identified as R. sophoriradicis and R. leguminosarum belong to the symbiovar phaseoli carrying the γ nodC allele distributed in P. vulgaris endosymbionts in America, Europe, Africa and Asia. The strain identified as R. tropici belongs to the symbiovar tropici carried by strains of R. tropici, R. leucaenae, R. lusitanum and R. freirei nodulating P. vulgaris in America, Africa and Asia. The strain identified as P. giardinii belongs to the symbiovar giardinii together with the type strain of this species nodulating P. vulgaris in France. It is remarkable that the recently described species R. sophoriradicis is worldwide distributed in P. vulgaris nodules carrying the γ nodC allele of symbiovar phaseoli harboured by rhizobia isolated in the American distribution centers of this legume.}, }
@article {pmid26831147, year = {2016}, author = {Lopes, MG and May Junior, J and Foster, RJ and Harmsen, BJ and Sanchez, E and Martins, TF and Quigley, H and Marcili, A and Labruna, MB}, title = {Ticks and rickettsiae from wildlife in Belize, Central America.}, journal = {Parasites &amp; vectors}, volume = {9}, number = {}, pages = {62}, pmid = {26831147}, issn = {1756-3305}, mesh = {Animals ; Animals, Wild ; Bacterial Proteins/genetics ; Belize/epidemiology ; Cluster Analysis ; DNA, Mitochondrial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/genetics/*isolation &amp; purification ; Rickettsia rickettsii ; Sequence Analysis, DNA ; Tick Infestations/*epidemiology/*parasitology ; Ticks/anatomy &amp; histology/*classification/genetics/*microbiology ; }, abstract = {BACKGROUND: The agents of spotted fevers in Latin America are Rickettsia rickettsii, R. parkeri, Rickettsia sp. strain Atlantic rainforest, and R. massiliae. In Continental Central America, R. rickettsii remains the only known pathogenic tick-borne rickettsia. In the present study, ticks were collected from wild mammals in natural areas of Belize. Besides providing new data of ticks from Belize, we investigated rickettsial infection in some of these ticks. Our results provide ticks harboring rickettsial agents for the first time in Central America.<br><br>METHODS: Between 2010 and 2015, wild mammals were lived-trapped in the tropical broadleaf moist forests of central and southern Belize. Ticks were collected from the animals and identified to species by morphological and molecular analysis (DNA sequence of the tick mitochondrial 16S RNA gene). Some of the ticks were tested for rickettsial infection by molecular methods (DNA sequences of the rickettsial gltA and ompA genes).<br><br>RESULTS: A total of 84 ticks were collected from 8 individual hosts, as follows: Amblyomma pacae from 3 Cuniculus paca; Amblyomma ovale and Amblyomma coelebs from a Nasua narica; A. ovale from an Eira Barbara; A. ovale, Amblyomma cf. oblongoguttatum, and Ixodes affinis from a Puma concolor; and A. ovale, A. coelebs, A. cf. oblongoguttatum, and I. affinis from two Panthera onca. Three rickettsial agents were detected: Rickettsia amblyommii in A. pacae, Rickettsia sp. strain Atlantic rainforest in A. ovale, and Rickettsia sp. endosymbiont in Ixodes affinis.<br><br>CONCLUSIONS: The present study provides unprecedented records of ticks harboring rickettsial agents in the New World. An emerging rickettsial pathogen of South America, Rickettsia sp. strain Atlantic rainforest, is reported for the first time in Central America. Besides expanding the distribution of 3 rickettsial agents in Central America, our results highlight the possible occurrence of Rickettsia sp. strain Atlantic rainforest-caused spotted fever human cases in Belize, since its possible vector, A. ovale, is recognized as one of the most important human-biting ticks in the Neotropical region.}, }
@article {pmid26826802, year = {2016}, author = {Guo, JY and Wan, FH and Ye, GY}, title = {Oogenesis in the Bemisia tabaci MEAM1 species complex.}, journal = {Micron (Oxford, England : 1993)}, volume = {83}, number = {}, pages = {1-10}, doi = {10.1016/j.micron.2016.01.003}, pmid = {26826802}, issn = {1878-4291}, mesh = {Animals ; Cell Differentiation ; *Hemiptera/cytology/ultrastructure ; Oocytes/cytology/ultrastructure ; *Oogenesis ; }, abstract = {The whitefly Bemisia tabaci MEAM1 species complex has invaded several parts of the world in the past 30 years and replaced native whitefly populations in the invaded regions, including certain areas of China. One of the possible reasons for the invasion is that MEAM1 whiteflies are more fecund than native species. However, the factors that affect the reproduction of the B. tabaci cryptic species are not clearly known. The regulation of oogenesis is thought to be one of the essential processes for egg formation and ovary development and could affect its population dynamics. In this study, the ovariole structure and oogenesis of the MEAM1 species complex was examined using light and transmission electron microscopy. Telotrophic ovarioles were observed in the MEAM1 species complex. Each ovariole had two well defined regions: the tropharium and the vitellarium. The tropharium always had more than ten trophocytes. The development of a single oocyte in the vitellarium has four phases: oocyte formation, previtellogenesis, vitellogenesis and choriogenesis. Two arrested oocytes, follicular cells and uncompleted oocytes were separated from the tropharium by microtubule and microfilaments. Early previtellogenesis oocytes absorbed nutrients and endosymbiont bacteria through a nutritive cord. However, the vitellogenesis of oocytes transmitted Vg through both the nutritive cord and the space between follicular cells. Each mature oocyte with deposited yolk proteins had only one bacteriocyte and was surrounded by a single layer of follicular cells. The oogenesis in the B. tabaci MEAM1 species complex concluded with the differentiation of oocytes, the transport of yolk and endosymbionts as well as the development and maturation of oocytes. This result provides important information that further defines the regulation of oogenesis in the B. tabaci complex.}, }
@article {pmid26826340, year = {2016}, author = {Zimmermann, J and Wentrup, C and Sadowski, M and Blazejak, A and Gruber-Vodicka, HR and Kleiner, M and Ott, JA and Cronholm, B and De Wit, P and Erséus, C and Dubilier, N}, title = {Closely coupled evolutionary history of ecto- and endosymbionts from two distantly related animal phyla.}, journal = {Molecular ecology}, volume = {25}, number = {13}, pages = {3203-3223}, doi = {10.1111/mec.13554}, pmid = {26826340}, issn = {1365-294X}, mesh = {Animals ; Annelida/*microbiology ; *Biological Evolution ; DNA, Bacterial/genetics ; Gammaproteobacteria/*genetics ; Genetic Markers ; Nematoda/*microbiology ; Oceans and Seas ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The level of integration between associated partners can range from ectosymbioses to extracellular and intracellular endosymbioses, and this range has been assumed to reflect a continuum from less intimate to evolutionarily highly stable associations. In this study, we examined the specificity and evolutionary history of marine symbioses in a group of closely related sulphur-oxidizing bacteria, called Candidatus Thiosymbion, that have established ecto- and endosymbioses with two distantly related animal phyla, Nematoda and Annelida. Intriguingly, in the ectosymbiotic associations of stilbonematine nematodes, we observed a high degree of congruence between symbiont and host phylogenies, based on their ribosomal RNA (rRNA) genes. In contrast, for the endosymbioses of gutless phallodriline annelids (oligochaetes), we found only a weak congruence between symbiont and host phylogenies, based on analyses of symbiont 16S rRNA genes and six host genetic markers. The much higher degree of congruence between nematodes and their ectosymbionts compared to those of annelids and their endosymbionts was confirmed by cophylogenetic analyses. These revealed 15 significant codivergence events between stilbonematine nematodes and their ectosymbionts, but only one event between gutless phallodrilines and their endosymbionts. Phylogenetic analyses of 16S rRNA gene sequences from 50 Cand. Thiosymbion species revealed seven well-supported clades that contained both stilbonematine ectosymbionts and phallodriline endosymbionts. This closely coupled evolutionary history of marine ecto- and endosymbionts suggests that switches between symbiotic lifestyles and between the two host phyla occurred multiple times during the evolution of the Cand. Thiosymbion clade, and highlights the remarkable flexibility of these symbiotic bacteria.}, }
@article {pmid26822159, year = {2016}, author = {Simonet, P and Duport, G and Gaget, K and Weiss-Gayet, M and Colella, S and Febvay, G and Charles, H and Viñuelas, J and Heddi, A and Calevro, F}, title = {Direct flow cytometry measurements reveal a fine-tuning of symbiotic cell dynamics according to the host developmental needs in aphid symbiosis.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {19967}, pmid = {26822159}, issn = {2045-2322}, mesh = {Animals ; Aphids/*microbiology ; Bacterial Load ; Buchnera/physiology ; Flow Cytometry ; *Symbiosis ; }, abstract = {Endosymbiotic associations constitute a driving force in the ecological and evolutionary diversification of metazoan organisms. Little is known about whether and how symbiotic cells are coordinated according to host physiology. Here, we use the nutritional symbiosis between the insect pest, Acyrthosiphon pisum, and its obligate symbiont, Buchnera aphidicola, as a model system. We have developed a novel approach for unculturable bacteria, based on flow cytometry, and used this method to estimate the absolute numbers of symbionts at key stages of aphid life. The endosymbiont population increases exponentially throughout nymphal development, showing a growing rate which has never been characterized by indirect molecular techniques. Using histology and imaging techniques, we have shown that the endosymbiont-bearing cells (bacteriocytes) increase significantly in number and size during the nymphal development, and clustering in the insect abdomen. Once adulthood is reached and the laying period has begun, the dynamics of symbiont and host cells is reversed: the number of endosymbionts decreases progressively and the bacteriocyte structure degenerates during insect aging. In summary, these results show a coordination of the cellular dynamics between bacteriocytes and primary symbionts and reveal a fine-tuning of aphid symbiotic cells to the nutritional demand imposed by the host physiology throughout development.}, }
@article {pmid26814170, year = {2016}, author = {Polka, JK and Silver, PA}, title = {A Tunable Protein Piston That Breaks Membranes to Release Encapsulated Cargo.}, journal = {ACS synthetic biology}, volume = {5}, number = {4}, pages = {303-311}, doi = {10.1021/acssynbio.5b00237}, pmid = {26814170}, issn = {2161-5063}, mesh = {Amino Acid Sequence ; Bacterial Proteins/chemistry/genetics/*metabolism ; Cell Wall/*metabolism ; Circular Dichroism ; Escherichia coli/*metabolism ; Genetic Vectors/genetics/metabolism ; Hydrogen-Ion Concentration ; Inclusion Bodies/chemistry/metabolism ; Microscopy, Electron ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Osmolar Concentration ; Recombinant Proteins/biosynthesis/chemistry/isolation &amp; purification ; Sequence Alignment ; Spectrophotometry ; }, abstract = {Movement of molecules across membranes in response to a stimulus is a key component of cellular programming. Here, we characterize and manipulate the response of a protein-based piston capable of puncturing membranes in a pH-dependent manner. Our protein actuator consists of modified R bodies found in a bacterial endosymbiont of paramecium. We express and purify R bodies from in E. coli; these pistons undergo multiple rounds of rapid extension and retraction. We developed a high throughput screen for mutants with altered pH sensitivity for tuning of the extension process. We show that the R bodies are capable of acting as synthetic pH-dependent pistons that can puncture E. coli membranes to release the trapped content. As such, these protein machines present a novel way to selectively rupture membrane compartments and will be important for programming cellular compartmentalization.}, }
@article {pmid26806463, year = {2016}, author = {Sharma, OP and Kumar, MS}, title = {Essential proteins and possible therapeutic targets of Wolbachia endosymbiont and development of FiloBase--a comprehensive drug target database for Lymphatic filariasis.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {19842}, pmid = {26806463}, issn = {2045-2322}, mesh = {Animals ; Bacterial Proteins/*biosynthesis/genetics ; Brugia malayi/microbiology/pathogenicity ; Databases, Genetic ; Elephantiasis, Filarial/drug therapy/*genetics/parasitology ; *Expressed Sequence Tags ; Gene Expression Regulation/genetics ; Genome, Bacterial ; Host-Pathogen Interactions/genetics ; Humans ; Proteome/drug effects/genetics ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Lymphatic filariasis (Lf) is one of the oldest and most debilitating tropical diseases. Millions of people are suffering from this prevalent disease. It is estimated to infect over 120 million people in at least 80 nations of the world through the tropical and subtropical regions. More than one billion people are in danger of getting affected with this life-threatening disease. Several studies were suggested its emerging limitations and resistance towards the available drugs and therapeutic targets for Lf. Therefore, better medicine and drug targets are in demand. We took an initiative to identify the essential proteins of Wolbachia endosymbiont of Brugia malayi, which are indispensable for their survival and non-homologous to human host proteins. In this current study, we have used proteome subtractive approach to screen the possible therapeutic targets for wBm. In addition, numerous literatures were mined in the hunt for potential drug targets, drugs, epitopes, crystal structures, and expressed sequence tag (EST) sequences for filarial causing nematodes. Data obtained from our study were presented in a user friendly database named FiloBase. We hope that information stored in this database may be used for further research and drug development process against filariasis. URL: http://filobase.bicpu.edu.in.}, }
@article {pmid26792263, year = {2016}, author = {Fan, HW and Lu, JB and Ye, YX and Yu, XP and Zhang, CX}, title = {Characteristics of the draft genome of "Candidatus Arsenophonus nilaparvatae", a facultative endosymbiont of Nilaparvata lugens.}, journal = {Insect science}, volume = {23}, number = {3}, pages = {478-486}, doi = {10.1111/1744-7917.12318}, pmid = {26792263}, issn = {1744-7917}, mesh = {Animals ; Bacterial Proteins/metabolism ; Enterobacteriaceae/*genetics ; *Genome, Bacterial ; Hemiptera/*microbiology/physiology ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; Vitamin B Complex/biosynthesis ; }, abstract = {There exists a kind of symbiotic bacterium named "Candidatus Arsenophonus nilaparvatae" in the brown planthopper (BPH), Nilaparvata lugens. After being filtered and assembled from the BPH genome sequencing project, the genome sequence of this bacterial symbiont was obtained. After initial analysis based on the genome, we have found its potential role to synthesize B vitamins for the host. In order to better understand the lifestyle and the genomic changes of this symbiotic bacterium after the symbiotic relationship was established, we further report the characteristics of this draft genome. Compared with several other related bacteria, "Candidatus Arsenophonus nilaparvatae" has proven to be a facultative endosymbiont at the genomic level. Concurrently, the presence of fimbriae and flagella formation related genes indicates this maternally transmitted endosymbiont is most likely to retain the capacity to invade new hosts. Through further analysis of annotated gene sets, we also find evidence of genome reduction in its secretion system and metabolic pathways. These findings reflect its evolutionary trend to be an obligate one and enable a deeper study of microbe-insect interactions.}, }
@article {pmid26790096, year = {2016}, author = {Martins, I and Romão, CV and Goulart, J and Cerqueira, T and Santos, RS and Bettencourt, R}, title = {Activity of antioxidant enzymes in response to atmospheric pressure induced physiological stress in deep-sea hydrothermal vent mussel Bathymodiolus azoricus.}, journal = {Marine environmental research}, volume = {114}, number = {}, pages = {65-73}, doi = {10.1016/j.marenvres.2016.01.003}, pmid = {26790096}, issn = {1879-0291}, mesh = {Animals ; Antioxidants/*metabolism ; *Atmospheric Pressure ; Azores ; Bacterial Physiological Phenomena ; Hydrothermal Vents ; Methane/metabolism ; Mytilidae/enzymology/microbiology/*physiology ; Oxidoreductases/metabolism ; Seawater/chemistry/*microbiology ; *Stress, Physiological ; Sulfides/metabolism ; Symbiosis ; }, abstract = {Deep sea hydrothermal Bathymodiolus azoricus mussels from Portuguese EEZ Menez Gwen hydrothermal field possess the remarkable ability to overcome decompression and survive successfully at atmospheric pressure conditions. We investigated the potential use of antioxidant defense enzymes in mussel B. azoricus as biomarkers of oxidative stress induced by long term acclimatization to atmospheric pressure conditions. Mussels collected at Menez Gwen hydrothermal field were acclimatized for two weeks in three distinct conditions suitable of promoting physiological stress, (i) in plain seawater for concomitant endosymbiont bacteria loss, (ii) in plain seawater under metal iron exposure, (iii) constant bubbling methane and pumped sulfide for endosymbiont bacteria survival. The enzymatic activities of superoxide dismutase (SOD), catalase (CAT), and iron storage proteins in addition to electrophoretic profiles were examined in vent mussel gills and digestive gland. Gills showed approximately 3 times more SOD specific activity than digestive glands. On the other hand, digestive glands showed approximately 6 times more CAT specific activity than gills. Iron storage proteins were identified in gill extracts from all experimental conditions mussels. However, in digestive gland extracts only fresh collected mussels and after 2 weeks in FeSO4 showed the presence of iron storage proteins. The differences between SOD, CAT specific activities and the presence of iron storage proteins in the examined tissues reflect dissimilar metabolic and antioxidant activities, as a result of tissue specificities and acclimatization conditions influences on the organism.}, }
@article {pmid26783021, year = {2017}, author = {Silvestre-Ferreira, AC and Vieira, L and Vilhena, H and Cerón, JJ and Tvarijonaviciute, A and Montoya-Alonso, JA and Carretón, E and Pastor, J}, title = {Serum acute phase proteins in Dirofilaria immitis and Wolbachia seropositive cats.}, journal = {Journal of feline medicine and surgery}, volume = {19}, number = {6}, pages = {693-696}, doi = {10.1177/1098612X15625435}, pmid = {26783021}, issn = {1532-2750}, mesh = {Acute-Phase Proteins/*analysis ; Animals ; Antibodies, Bacterial/*blood ; Cat Diseases/blood/*diagnosis ; Cats ; Dirofilaria immitis/*immunology ; Dirofilariasis/blood/*diagnosis ; Female ; Male ; Predictive Value of Tests ; Serologic Tests/veterinary ; Wolbachia/*immunology ; }, abstract = {Objectives The aim of this study was to characterise the response of acute phase proteins (APPs) in cats seropositive for Dirofilaria immitis and to its endosymbiont bacterium Wolbachia. Methods The APPs serum amyloid A (SAA), haptoglobin (Hp) and ceruloplasmin (Cp) were measured in 25 seropositive cats and in 16 healthy seronegative cats. Results SAA and Cp concentrations were significantly higher in animals with D immitis seropositivity that exhibited clinical signs related to the disease, and Hp was elevated in all D immitis-seropositive animals. There was no significant correlation between APPs and D immitis or Wolbachia species antibody titres. Conclusions and relevance An association between feline seropositivity to D immitis and APP response was demonstrated. Increases in serum SAA and Cp concentrations were related to D immitis-associated clinical signs, whereas Hp increased in all seropositive animals.}, }
@article {pmid26782934, year = {2016}, author = {Matelska, D and Kurkowska, M and Purta, E and Bujnicki, JM and Dunin-Horkawicz, S}, title = {Loss of Conserved Noncoding RNAs in Genomes of Bacterial Endosymbionts.}, journal = {Genome biology and evolution}, volume = {8}, number = {2}, pages = {426-438}, pmid = {26782934}, issn = {1759-6653}, mesh = {Base Composition ; Buchnera/*genetics ; Conserved Sequence ; *Genome, Bacterial ; Mycoplasma/*genetics ; Open Reading Frames ; RNA, Long Noncoding/*genetics ; Rickettsia/*genetics ; *Sequence Deletion ; Symbiosis ; }, abstract = {The genomes of intracellular symbiotic or pathogenic bacteria, such as of Buchnera, Mycoplasma, and Rickettsia, are typically smaller compared with their free-living counterparts. Here we showed that noncoding RNA (ncRNA) families, which are conserved in free-living bacteria, frequently could not be detected by computational methods in the small genomes. Statistical tests demonstrated that their absence is not an artifact of low GC content or small deletions in these small genomes, and thus it was indicative of an independent loss of ncRNAs in different endosymbiotic lineages. By analyzing the synteny (conservation of gene order) between the reduced and nonreduced genomes, we revealed instances of protein-coding genes that were preserved in the reduced genomes but lost cis-regulatory elements. We found that the loss of cis-regulatory ncRNA sequences, which regulate the expression of cognate protein-coding genes, is characterized by the reduction of secondary structure formation propensity, GC content, and length of the corresponding genomic regions.}, }
@article {pmid26773849, year = {2017}, author = {Sepúlveda, DA and Zepeda-Paulo, F and Ramírez, CC and Lavandero, B and Figueroa, CC}, title = {Diversity, frequency, and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests.}, journal = {Insect science}, volume = {24}, number = {3}, pages = {511-521}, doi = {10.1111/1744-7917.12313}, pmid = {26773849}, issn = {1744-7917}, mesh = {Animals ; Aphids/*microbiology ; Enterobacteriaceae/*isolation &amp; purification ; Rickettsia/isolation &amp; purification ; Spiroplasma/isolation &amp; purification ; *Symbiosis ; }, abstract = {Facultative bacterial endosymbionts in insects have been under intense study during the last years. Endosymbionts can modify the insect's phenotype, conferring adaptive advantages under environmental stress. This seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness-related traits, including host plant use, protection against natural enemies and heat tolerance. Aimed to understand the role of facultative endosymbionts on the success of introduced aphid pests, the distribution and abundance of 5 facultative endosymbionts (Hamiltonella defensa, Regiella insecticola, Serratia symbiotica, Rickettsia and Spiroplasma) were studied and compared in 4 cereal aphids (Sitobion avenae, Diuraphis noxia, Metopolophium dirhodum and Schizaphis graminium) and in the pea aphid Acyrthosiphon pisum complex from 2 agroclimatic zones in Chile. Overall, infections with facultative endosymbionts exhibited a highly variable and characteristic pattern depending on the aphid species/host race and geographic zone, which could explain the success of aphid pest populations after their introduction. While S. symbiotica and H. defensa were the most frequent endosymbionts carried by the A. pisum pea-race and A. pisum alfalfa-race aphids, respectively, the most frequent facultative endosymbiont carried by all cereal aphids was R. insecticola. Interestingly, a highly variable composition of endosymbionts carried by S. avenae was also observed between agroclimatic zones, suggesting that endosymbionts are responding differentially to abiotic variables (temperature and precipitations). In addition, our findings constitute the first report of bacterial endosymbionts in cereal aphid species not screened before, and also the first report of aphid endosymbionts in Chile.}, }
@article {pmid26754353, year = {2016}, author = {Chong, G and Tsai, S and Wang, LH and Huang, CY and Lin, C}, title = {Cryopreservation of the gorgonian endosymbiont Symbiodinium.}, journal = {Scientific reports}, volume = {6}, number = {}, pages = {18816}, pmid = {26754353}, issn = {2045-2322}, mesh = {Adenosine Triphosphate/metabolism ; Cell Count ; *Cryopreservation ; Cryoprotective Agents ; *Dinoflagellida/physiology ; Freezing ; Sucrose ; Symbiosis ; }, abstract = {The study focused on finding a suitable cryoprotectant (CPA) and an optimum freezing protocol for the cryopreservation of the endosymbiotic dinoflagellates (Symbiodinium, clade G) of Junceella fragilis wherein the success of experiments is crucial to both scientific and ecology studies. A two-step freezing technique was developed. The viability of the thawed dinoflagellates was assayed using the adenosine triphosphate (ATP) bioassay for the first time and was further confirmed through the culturing of dinoflagellates in vitro. The results suggested that 30 min was the most suitable holding time for the dinoflagellates, and the samples produced highest viability when suspended at 5 cm from the surface of LN2. Results also showed that 1 M methanol with 0.4 M sucrose was the most effective CPA, yielding the highest viability (56.93%). Although cell densities of both cryopreserved and control group suffered an initial decline of culture, the cell densities were maintained throughout the remaining duration. In the present study, the cryopreservation of clade G endosymbiont algae was studied for the first time and the method described here could be applied for future studies on symbiotic algae cryopreservation.}, }
@article {pmid26751816, year = {2016}, author = {Trout Fryxell, RT and DeBruyn, JM}, title = {The Microbiome of Ehrlichia-Infected and Uninfected Lone Star Ticks (Amblyomma americanum).}, journal = {PloS one}, volume = {11}, number = {1}, pages = {e0146651}, pmid = {26751816}, issn = {1932-6203}, mesh = {*Anaplasma ; Animals ; DNA, Bacterial/analysis ; Ecosystem ; *Ehrlichia ; Female ; Male ; *Microbiota ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; Tick-Borne Diseases/*microbiology ; Ticks/*microbiology ; }, abstract = {The Lone Star tick, Amblyomma americanum, transmits several bacterial pathogens including species of Anaplasma and Ehrlichia. Amblyomma americanum also hosts a number of non-pathogenic bacterial endosymbionts. Recent studies of other arthropod and insect vectors have documented that commensal microflora can influence transmission of vector-borne pathogens; however, little is known about tick microbiomes and their possible influence on tick-borne diseases. Our objective was to compare bacterial communities associated with A. americanum, comparing Anaplasma/Ehrlichia -infected and uninfected ticks. Field-collected questing specimens (n = 50) were used in the analyses, of which 17 were identified as Anaplasma/Ehrlichia infected based on PCR amplification and sequencing of groEL genes. Bacterial communities from each specimen were characterized using Illumina sequencing of 16S rRNA gene amplicon libraries. There was a broad range in diversity between samples, with inverse Simpson's Diversity indices ranging from 1.28-89.5. There were no statistical differences in the overall microbial community structure between PCR diagnosed Anaplasma/Ehrlichia-positive and negative ticks, but there were differences based on collection method (P < 0.05), collection site (P < 0.05), and sex (P < 0.1) suggesting that environmental factors may structure A. americanum microbiomes. Interestingly, there was not always agreement between Illumina sequencing and PCR diagnostics: Ehrlichia was identified in 16S rRNA gene libraries from three PCR-negative specimens; conversely, Ehrlichia was not found in libraries of six PCR-positive ticks. Illumina sequencing also helped identify co-infections, for example, one specimen had both Ehrlichia and Anaplasma. Other taxa of interest in these specimens included Coxiella, Borrelia, and Rickettsia. Identification of bacterial community differences between specimens of a single tick species from a single geographical site indicates that intra-species differences in microbiomes were not due solely to pathogen presence/absence, but may be also driven by vector life history factors, including environment, life stage, population structure, and host choice.}, }
@article {pmid26748854, year = {2016}, author = {Lowe, CD and Minter, EJ and Cameron, DD and Brockhurst, MA}, title = {Shining a Light on Exploitative Host Control in a Photosynthetic Endosymbiosis.}, journal = {Current biology : CB}, volume = {26}, number = {2}, pages = {207-211}, doi = {10.1016/j.cub.2015.11.052}, pmid = {26748854}, issn = {1879-0445}, mesh = {Biological Evolution ; Chlorella/*physiology ; Light ; Paramecium/*physiology ; Photosynthesis/*physiology ; Symbiosis/*physiology ; }, abstract = {Endosymbiosis allows hosts to acquire new functional traits such that the combined host and endosymbiont can exploit vacant ecological niches and occupy novel environments [1, 2]; consequently, endosymbiosis affects the structure and function of ecosystems [3, 4]. However, for many endosymbioses, it is unknown whether their evolutionary basis is mutualism or exploitation [5-9]. We estimated the fitness consequences of symbiosis using the interaction between the protist host Paramecium bursaria and the algal symbiont Chlorella sp. [10]. Host fitness was strongly context dependent: whereas hosts benefited from symbiosis at high light intensity, carrying endosymbionts was costly to hosts in the dark and conferred no benefit over growing autonomously at intermediate light levels. Autonomous Chlorella densities increased monotonically with light intensity, whereas per-host symbiont load and symbiont abundance peaked at intermediate light levels and were lowest at high light intensity. This suggests that hosts controlled the costs of symbiosis by manipulating symbiont load according to light intensity. Photosynthetic efficiency was consistently lower for symbiotic compared to autonomous algae, suggesting nutritional constraints upon algae in symbiosis. At intermediate light levels, we observed the establishment of small populations of free-living algae alongside the hosts with endosymbionts, suggesting that symbionts could escape symbiosis, but only under conditions where hosts didn't benefit from symbiosis. Together, these data suggest that hosts exerted strong control over endosymbionts and that there were no conditions where this nutritional symbiosis was mutually beneficial. Our findings support theoretical predictions (e.g., [5, 9]) that controlled exploitation is an important evolutionary pathway toward stable endosymbiosis.}, }
@article {pmid26746715, year = {2016}, author = {Wilkinson, DA and Duron, O and Cordonin, C and Gomard, Y and Ramasindrazana, B and Mavingui, P and Goodman, SM and Tortosa, P}, title = {The Bacteriome of Bat Flies (Nycteribiidae) from the Malagasy Region: a Community Shaped by Host Ecology, Bacterial Transmission Mode, and Host-Vector Specificity.}, journal = {Applied and environmental microbiology}, volume = {82}, number = {6}, pages = {1778-1788}, pmid = {26746715}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; Chiroptera/parasitology ; Diptera/*microbiology ; Madagascar ; *Microbiota ; }, abstract = {The Nycteribiidae are obligate blood-sucking Diptera (Hippoboscoidea) flies that parasitize bats. Depending on species, these wingless flies exhibit either high specialism or generalism toward their hosts, which may in turn have important consequences in terms of their associated microbial community structure. Bats have been hypothesized to be reservoirs of numerous infectious agents, some of which have recently emerged in human populations. Thus, bat flies may be important in the epidemiology and transmission of some of these bat-borne infectious diseases, acting either directly as arthropod vectors or indirectly by shaping pathogen communities among bat populations. In addition, bat flies commonly have associations with heritable bacterial endosymbionts that inhabit insect cells and depend on maternal transmission through egg cytoplasm to ensure their transmission. Some of these heritable bacteria are likely obligate mutualists required to support bat fly development, but others are facultative symbionts with unknown effects. Here, we present bacterial community profiles that were obtained from seven bat fly species, representing five genera, parasitizing bats from the Malagasy region. The observed bacterial diversity includes Rickettsia, Wolbachia, and several Arsenophonus-like organisms, as well as other members of the Enterobacteriales and a widespread association of Bartonella bacteria from bat flies of all five genera. Using the well-described host specificity of these flies and data on community structure from selected bacterial taxa with either vertical or horizontal transmission, we show that host/vector specificity and transmission mode are important drivers of bacterial community structure.}, }
@article {pmid26741324, year = {2016}, author = {Duzlu, O and Yildirim, A and Inci, A and Gumussoy, KS and Ciloglu, A and Onder, Z}, title = {Molecular Investigation of Francisella-Like Endosymbiont in Ticks and Francisella tularensis in Ixodid Ticks and Mosquitoes in Turkey.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {16}, number = {1}, pages = {26-32}, doi = {10.1089/vbz.2015.1818}, pmid = {26741324}, issn = {1557-7759}, mesh = {Animals ; Culicidae/*microbiology ; DNA, Bacterial/genetics/isolation &amp; purification ; Francisella tularensis/*isolation &amp; purification ; Ixodidae/*microbiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Real-Time Polymerase Chain Reaction ; Turkey ; }, abstract = {This study was carried out to investigate the molecular prevalence of Francisella-like endosymbionts (FLEs) and Francisella tularensis in ticks (Acari: Ixodidae) and mosquitoes in Turkey. Genomic DNA pools were constructed from a total of 1477 adult hard ticks of Rhipicephalus (Rh.) annulatus, Rh. turanicus, Rh. sanguineus, Rh. bursa, Haemaphysalis (Hae.) parva, Hae. sulcata, Hyalomma marginatum marginatum, H. anatolicum anatolicum, H. anatolicum excavatum, H. detritum detritum, H. dromedarii, Dermacentor marginatus, and Ixodes ricinus species, which were collected from several barns, cattle, and people. Genomic DNA was also extracted from pools consisting of 6203 adult female mosquito species belonging to Aedes vexans, Culex (Cx.) pipiens, Cx. hortensis, Cx. theileri, Culiseta annulata, and Anopheles maculipennis species. Conventional PCR and TaqMan probe-based real- time PCR targeting the 16S rRNA gene for FLEs and the lpnA gene for F. tularensis, respectively, were performed on the DNA isolates obtained. FLEs and F. tularensis were not found in any genomic DNA pools constructed from ixodid ticks and mosquitos. This study represents the first investigation of F. tularensis and FLEs in potential vector ticks and mosquitoes by molecular methods in Turkey. The present study provides useful insights into the molecular epidemiology of F. tularensis and FLEs. One of the major conclusions of the study is that tularemia outbreaks may be essentially due to direct transmission from the environment (especially from water) in Turkey and not to vector-borne transmission.}, }
@article {pmid26733969, year = {2015}, author = {Braquart-Varnier, C and Raimond, M and Mappa, G and Chevalier, FD and Le Clec'h, W and Sicard, M}, title = {The Hematopoietic Organ: A Cornerstone for Wolbachia Propagation Between and Within Hosts.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {1424}, pmid = {26733969}, issn = {1664-302X}, abstract = {Wolbachia is an intracellular α-proteobacterium which is transmitted vertically from mother to offspring but also frequently switches horizontally from one host to another. Our hypothesis is based on the role of immune cells and the organs that produce them, the hematopoietic organs (HOs), as primordial niches for the propagation of Wolbachia via hemocytes both (i) within hosts: to initiate and maintain the systemic infection and (ii) between hosts: to promote both vertical and horizontal transmission of Wolbachia. Therefore, we review some fundamental ideas underlying this hypothesis and go further with new empirical data that lead to a first close-up analysis of the potential role of HOs in Wolbachia propagation. The monitoring of the first steps of Wolbachia infection in horizontally infected host organs by transmission electron microscopy and qPCR suggests that (i) HOs are colonized early and extensively as soon as they are in contact with Wolbachia which find in these cells a favorable niche to multiply and (ii) infected HOs which expel hemocytes all lifelong can generate and maintain a systemic infection that could contribute to increase both vertical and horizontal propagation of these symbionts.}, }
@article {pmid26733946, year = {2015}, author = {Braquart-Varnier, C and Altinli, M and Pigeault, R and Chevalier, FD and Grève, P and Bouchon, D and Sicard, M}, title = {The Mutualistic Side of Wolbachia-Isopod Interactions: Wolbachia Mediated Protection Against Pathogenic Intracellular Bacteria.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {1388}, pmid = {26733946}, issn = {1664-302X}, abstract = {Wolbachia is a vertically transmitted endosymbiont whose radiative success is mainly related to various host reproductive manipulations that led to consider this symbiont as a conflictual reproductive parasite. However, lately, some Wolbachia have been shown to act as beneficial symbionts by protecting hosts against a broad range of parasites. Still, this protection has been mostly demonstrated in artificial Wolbachia-host associations between partners that did not co-evolved together. Here, we tested in two terrestrial isopod species Armadillidium vulgare and Porcellio dilatatus whether resident Wolbachia (native or non-native) could confer protection during infections with Listeria ivanovii and Salmonella typhimurium and also during a transinfection with a Wolbachia strain that kills the recipient host (i.e., wVulC in P. dilatatus). Survival analyses showed that (i) A. vulgare lines hosting their native Wolbachia (wVulC) always exhibited higher survival than asymbiotic ones when infected with pathogenic bacteria (ii) P. dilatatus lines hosting their native wDil Wolbachia strain survived the S. typhimurium infection better, while lines hosting non-native wCon Wolbachia strain survived the L. ivanovii and also the transinfection with wVulC from A. vulgare better. By studying L. ivanovii and S. typhimurium loads in the hemolymph of the different host-Wolbachia systems, we showed that (i) the difference in survival between lines after L. ivanovii infections were not linked to the difference between their pathogenic bacterial loads, and (ii) the difference in survival after S. typhimurium infections corresponds to lower loads of pathogenic bacteria. Overall, our results demonstrate a beneficial effect of Wolbachia on survival of terrestrial isopods when infected with pathogenic intracellular bacteria. This protective effect may rely on different mechanisms depending on the resident symbiont and the invasive bacteria interacting together within the hosts.}, }
@article {pmid26731731, year = {2016}, author = {Szokoli, F and Sabaneyeva, E and Castelli, M and Krenek, S and Schrallhammer, M and Soares, CA and da Silva-Neto, ID and Berendonk, TU and Petroni, G}, title = {"Candidatus Fokinia solitaria", a Novel "Stand-Alone" Symbiotic Lineage of Midichloriaceae (Rickettsiales).}, journal = {PloS one}, volume = {11}, number = {1}, pages = {e0145743}, pmid = {26731731}, issn = {1932-6203}, mesh = {Alphaproteobacteria/classification/genetics/*physiology ; Evolution, Molecular ; Host-Pathogen Interactions ; In Situ Hybridization, Fluorescence ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Paramecium/classification/*microbiology ; Phylogeny ; RNA, Bacterial/chemistry/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Waste Water/*parasitology ; }, abstract = {Recently, the family Midichloriaceae has been described within the bacterial order Rickettsiales. It includes a variety of bacterial endosymbionts detected in different metazoan host species belonging to Placozoa, Cnidaria, Arthropoda and Vertebrata. Representatives of Midichloriaceae are also considered possible etiological agents of certain animal diseases. Midichloriaceae have been found also in protists like ciliates and amoebae. The present work describes a new bacterial endosymbiont, "Candidatus Fokinia solitaria", retrieved from three different strains of a novel Paramecium species isolated from a wastewater treatment plant in Rio de Janeiro (Brazil). Symbionts were characterized through the full-cycle rRNA approach: SSU rRNA gene sequencing and fluorescence in situ hybridization (FISH) with three species-specific oligonucleotide probes. In electron micrographs, the tiny rod-shaped endosymbionts (1.2 x 0.25-0.35 μm in size) were not surrounded by a symbiontophorous vacuole and were located in the peripheral host cytoplasm, stratified in the host cortex in between the trichocysts or just below them. Frequently, they occurred inside autolysosomes. Phylogenetic analyses of Midichloriaceae apparently show different evolutionary pathways within the family. Some genera, such as "Ca. Midichloria" and "Ca. Lariskella", have been retrieved frequently and independently in different hosts and environmental surveys. On the contrary, others, such as Lyticum, "Ca. Anadelfobacter", "Ca. Defluviella" and the presently described "Ca. Fokinia solitaria", have been found only occasionally and associated to specific host species. These last are the only representatives in their own branches thus far. Present data do not allow to infer whether these genera, which we named "stand-alone lineages", are an indication of poorly sampled organisms, thus underrepresented in GenBank, or represent fast evolving, highly adapted evolutionary lineages.}, }
@article {pmid26721865, year = {2016}, author = {Skelton, E and Rancès, E and Frentiu, FD and Kusmintarsih, ES and Iturbe-Ormaetxe, I and Caragata, EP and Woolfit, M and O'Neill, SL}, title = {A Native Wolbachia Endosymbiont Does Not Limit Dengue Virus Infection in the Mosquito Aedes notoscriptus (Diptera: Culicidae).}, journal = {Journal of medical entomology}, volume = {53}, number = {2}, pages = {401-408}, pmid = {26721865}, issn = {0022-2585}, mesh = {Animals ; Culicidae/*virology ; Dengue Virus/*physiology ; Female ; Ovary/microbiology ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {The endosymbiotic bacterium Wolbachia pipientis infects many species of insects and has been transinfected into the mosquito Aedes aegypti (L.), the primary vector of dengue virus (DENV). Recently, it has been shown that Wolbachia blocks the replication and transmission of RNA viruses, such as DENV, in a number of mosquito species including Ae. aegypti and Aedes albopictus (Skuse), which is naturally infected with Wolbachia and considered a secondary vector for DENV. The mosquito species Aedes notoscriptus (Skuse) is highly prevalent in Australia, including in areas where DENV outbreaks have been recorded. The mosquito has been implicated in the transmission of Ross River and Barmah Forest viruses, but not DENV. We investigated whether Wolbachia naturally infects this mosquito species and whether it has an impact on the ability of Ae. notoscriptus to transmit DENV. We show, for the first time, that Ae. notoscriptus is naturally infected with a strain of Wolbachia that belongs to supergroup B and is localized only in the ovaries. However, Wolbachia infection in Ae. notoscriptus did not induce resistance to DENV and had no effect on overall DENV infection rate or titer. The presence of a native Wolbachia in Ae. notoscriptus cannot explain why this mosquito is an ineffective vector of DENV.}, }
@article {pmid26713350, year = {2016}, author = {Montiel, J and Szűcs, A and Boboescu, IZ and Gherman, VD and Kondorosi, &#xc9; and Kereszt, A}, title = {Terminal Bacteroid Differentiation Is Associated With Variable Morphological Changes in Legume Species Belonging to the Inverted Repeat-Lacking Clade.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {29}, number = {3}, pages = {210-219}, doi = {10.1094/MPMI-09-15-0213-R}, pmid = {26713350}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Bacteria/*classification/ultrastructure ; Fabaceae/*genetics/metabolism ; Gene Expression Regulation, Plant/physiology ; Inverted Repeat Sequences/*genetics ; *Phylogeny ; Plant Proteins ; }, abstract = {Medicago and closely related legume species from the inverted repeat-lacking clade (IRLC) impose terminal differentiation onto their bacterial endosymbionts, manifested in genome endoreduplication, cell enlargement, and loss of cell-division capacity. Nodule-specific cysteine-rich (NCR) secreted host peptides are plant effectors of this process. As bacteroids in other IRLC legumes, such as Cicer arietinum and Glycyrrhiza lepidota, were reported not to display features of terminal differentiation, we investigated the fate of bacteroids in species from these genera as well as in four other species representing distinct genera of the phylogenetic tree for this clade. Bacteroids in all tested legumes proved to be larger in size and DNA content than cultured cells; however, the degree of cell elongation was rather variable in the different species. In addition, the reproductive ability of the bacteroids isolated from these legumes was remarkably reduced. In all IRLC species with available sequence data, the existence of NCR genes was found. These results indicate that IRLC legumes provoke terminal differentiation of their endosymbionts with different morphotypes, probably with the help of NCR peptides.}, }
@article {pmid26712000, year = {2016}, author = {Hamilton, PT and Peng, F and Boulanger, MJ and Perlman, SJ}, title = {A ribosome-inactivating protein in a Drosophila defensive symbiont.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {113}, number = {2}, pages = {350-355}, pmid = {26712000}, issn = {1091-6490}, mesh = {Animals ; Drosophila/*metabolism/*microbiology ; Endoribonucleases/chemistry ; Fungal Proteins/chemistry ; Polymerase Chain Reaction ; RNA, Ribosomal, 28S/metabolism ; Rabbits ; Recombinant Proteins/isolation &amp; purification ; Ribosome Inactivating Proteins/*metabolism ; Ribosomes/metabolism ; Ricin/chemistry ; Sequence Analysis, RNA ; Spiroplasma/*physiology ; *Symbiosis ; }, abstract = {Vertically transmitted symbionts that protect their hosts against parasites and pathogens are well known from insects, yet the underlying mechanisms of symbiont-mediated defense are largely unclear. A striking example of an ecologically important defensive symbiosis involves the woodland fly Drosophila neotestacea, which is protected by the bacterial endosymbiont Spiroplasma when parasitized by the nematode Howardula aoronymphium. The benefit of this defense strategy has led to the rapid spread of Spiroplasma throughout the range of D. neotestacea, although the molecular basis for this protection has been unresolved. Here, we show that Spiroplasma encodes a ribosome-inactivating protein (RIP) related to Shiga-like toxins from enterohemorrhagic Escherichia coli and that Howardula ribosomal RNA (rRNA) is depurinated during Spiroplasma-mediated protection of D. neotestacea. First, we show that recombinant Spiroplasma RIP catalyzes depurination of 28S rRNAs in a cell-free assay, as well as Howardula rRNA in vitro at the canonical RIP target site within the α-sarcin/ricin loop (SRL) of 28S rRNA. We then show that Howardula parasites in Spiroplasma-infected flies show a strong signal of rRNA depurination consistent with RIP-dependent modification and large decreases in the proportion of 28S rRNA intact at the α-sarcin/ricin loop. Notably, host 28S rRNA is largely unaffected, suggesting targeted specificity. Collectively, our study identifies a novel RIP in an insect defensive symbiont and suggests an underlying RIP-dependent mechanism in Spiroplasma-mediated defense.}, }
@article {pmid26711515, year = {2016}, author = {Axford, JK and Ross, PA and Yeap, HL and Callahan, AG and Hoffmann, AA}, title = {Fitness of wAlbB Wolbachia Infection in Aedes aegypti: Parameter Estimates in an Outcrossed Background and Potential for Population Invasion.}, journal = {The American journal of tropical medicine and hygiene}, volume = {94}, number = {3}, pages = {507-516}, pmid = {26711515}, issn = {1476-1645}, mesh = {Aedes/*microbiology ; Animals ; Bacterial Load ; Cell Survival ; Female ; Fertility ; *Genetic Fitness ; Host-Pathogen Interactions ; Male ; Ovum/microbiology/physiology ; Wolbachia/classification/genetics/*physiology ; }, abstract = {Wolbachia endosymbionts are potentially useful tools for suppressing disease transmission by Aedes aegypti mosquitoes because Wolbachia can interfere with the transmission of dengue and other viruses as well as causing deleterious effects on their mosquito hosts. Most recent research has focused on the wMel infection, but other infections also influence viral transmission and may spread in natural populations. Here, we focus on the wAlbB infection in an Australian outbred background and show that this infection has many features that facilitate its invasion into natural populations including strong cytoplasmic incompatibility, a lack of effect on larval development, an equivalent mating success to uninfected males and perfect maternal transmission fidelity. On the other hand, the infection has deleterious effects when eggs are held in a dried state, falling between wMel and the more virulent wMelPop Wolbachia strains. The impact of this infection on lifespan also appears to be intermediate, consistent with the observation that this infection has a titer in adults between wMel and wMelPop. Population cage experiments indicate that the wAlbB infection establishes in cages when introduced at a frequency of 22%, suggesting that this strain could be successfully introduced into populations and subsequently persist and spread.}, }
@article {pmid26699661, year = {2016}, author = {Laughton, AM and Garcia, JR and Gerardo, NM}, title = {Condition-dependent alteration of cellular immunity by secondary symbionts in the pea aphid, Acyrthosiphon pisum.}, journal = {Journal of insect physiology}, volume = {86}, number = {}, pages = {17-24}, doi = {10.1016/j.jinsphys.2015.12.005}, pmid = {26699661}, issn = {1879-1611}, mesh = {Animals ; Aphids/enzymology/*immunology/*microbiology ; Female ; *Immunity, Cellular ; Monophenol Monooxygenase/metabolism ; Serratia/*physiology ; Symbiosis ; }, abstract = {Endosymbionts can fundamentally alter host physiology. Whether such changes are beneficial or detrimental to one or both partners may depend on the dynamics of the symbiotic relationship. Here we investigate the relationship between facultative symbionts and host immune responses. The pea aphid, Acyrthosiphon pisum, maintains an obligate primary symbiont, but may also harbour one or more facultative, secondary symbionts. Given their more transient nature and relatively recent adoption of a symbiotic lifestyle compared to primary symbionts, secondary symbionts may present a challenge for the host immune system. We assessed the response of several key components of the cellular immune system (phenoloxidase activity, encapsulation, immune cell counts) in the presence of alternative secondary symbionts, investigating the role of host and secondary symbiont genotype in specific responses. There was no effect of secondary symbiont presence on the phenoloxidase response, but we found variation in the encapsulation response and in immune cell counts based largely on the secondary symbiont. Host genotype was less influential in determining immunity outcomes. Our results highlight the importance of secondary symbionts in shaping host immunity. Understanding the complex physiological responses that can be propagated by host-symbiont associations has important consequences for host ecology, including symbiont and pathogen transmission dynamics.}, }
@article {pmid26693682, year = {2016}, author = {Gazis, R and Kuo, A and Riley, R and LaButti, K and Lipzen, A and Lin, J and Amirebrahimi, M and Hesse, CN and Spatafora, JW and Henrissat, B and Hainaut, M and Grigoriev, IV and Hibbett, DS}, title = {The genome of Xylona heveae provides a window into fungal endophytism.}, journal = {Fungal biology}, volume = {120}, number = {1}, pages = {26-42}, doi = {10.1016/j.funbio.2015.10.002}, pmid = {26693682}, issn = {1878-6146}, mesh = {Ascomycota/classification/*genetics/physiology ; DNA, Fungal/genetics ; DNA, Ribosomal Spacer/genetics ; Endophytes/classification/*genetics/isolation &amp; purification/physiology ; *Genome, Fungal ; Hevea/*microbiology ; Molecular Sequence Data ; Phylogeny ; }, abstract = {Xylona heveae has only been isolated as an endophyte of rubber trees. In an effort to understand the genetic basis of endophytism, we compared the genome contents of X. heveae and 36 other Ascomycota with diverse lifestyles and nutritional modes. We focused on genes that are known to be important in the host-fungus interaction interface and that presumably have a role in determining the lifestyle of a fungus. We used phylogenomic data to infer the higher-level phylogenetic position of the Xylonomycetes, and mined ITS sequences to explore its taxonomic and ecological diversity. The X. heveae genome contains a low number of enzymes needed for plant cell wall degradation, suggesting that Xylona is a highly adapted specialist and likely dependent on its host for survival. The reduced repertoire of carbohydrate active enzymes could reflect an adaptation to intercellulary growth and to the avoidance of the host's immune system, suggesting that Xylona has a strictly endophytic lifestyle. Phylogenomic data resolved the position of Xylonomycetes as sister to Lecanoromycetes and Eurotiomycetes and placed the beetle-endosymbiont Symbiotaphrina as a member of this class. ITS data revealed that Trinosporium is also part of the Xylonomycetes, extending the taxonomic and ecological diversity of this group.}, }
@article {pmid26687455, year = {2016}, author = {Dürichen, H and Siegmund, L and Burmester, A and Fischer, MS and Wöstemeyer, J}, title = {Ingestion and digestion studies in Tetrahymena pyriformis based on chemically modified microparticles.}, journal = {European journal of protistology}, volume = {52}, number = {}, pages = {45-57}, doi = {10.1016/j.ejop.2015.11.004}, pmid = {26687455}, issn = {1618-0429}, mesh = {Animals ; Cell-Derived Microparticles/metabolism ; Escherichia coli/metabolism ; Ligands ; Phagocytosis/physiology ; Protein Binding ; Symbiosis/physiology ; Tetrahymena pyriformis/*metabolism ; }, abstract = {Recognition of food and, in consequence, ingestion of digestible particles is a prerequisite for energy metabolism in Tetrahymena pyriformis. Understanding why some particles are ingested and digested, whereas others are not, is important for many fields of research, e.g. survival of pathogens in single-celled organisms or establishment of endosymbiotic relationships. We offered T. pyriformis synthetical bovine-serum-albumin (BSA)-methacrylate microparticles of approximately 5.5 μm diameter and studied the ciliates' ingestion and digestion behaviour. Different staining techniques as well as co-feeding with a transformant strain of Escherichia coli revealed that T. pyriformis considers these particles as natural food source and shows no feeding preference. Further, they are ingested at normal rates and may serve as sole food source. A pivotal advantage of these particles is the convenient modification of their surface by binding different ligands resulting in defined surface properties. Ingestion rate of modified microparticles either increased (additional BSA, enzymes) or decreased (amino acids). Furthermore, we investigated glycosylation patterns by lectin binding. By binding different substances to the surface in combination with various staining techniques, we provide a versatile experimental tool for elucidating details on food recognition and digestion that may allow to study evading digestion by pathogens or potential endosymbionts, too.}, }
@article {pmid26686612, year = {2016}, author = {Liu, N and Chen, GQ and Ning, GA and Shi, HB and Zhang, CL and Lu, JP and Mao, LJ and Feng, XX and Liu, XH and Su, ZZ and Lin, FC}, title = {Agrobacterium tumefaciens-mediated transformation: An efficient tool for insertional mutagenesis and targeted gene disruption in Harpophora oryzae.}, journal = {Microbiological research}, volume = {182}, number = {}, pages = {40-48}, doi = {10.1016/j.micres.2015.09.008}, pmid = {26686612}, issn = {1618-0623}, mesh = {Agrobacterium tumefaciens/*genetics/metabolism ; Ascomycota/*genetics/physiology ; Gene Silencing ; Genetic Vectors/genetics/metabolism ; Mutagenesis, Insertional/*methods ; Oryza/microbiology ; Plant Diseases/microbiology ; *Transformation, Genetic ; }, abstract = {The endophytic filamentous fungus Harpophora oryzae is a beneficial endosymbiont isolated from the wild rice. H. oryzae could not only effectively improve growth rate and biomass yield of rice crops, but also induce systemic resistance against the rice blast fungus, Magnaporthe oryzae. In this study, Agrobacterium tumefaciens-mediated transformation (ATMT) was employed and optimized to modify the H. oryzae genes by either random DNA fragment integration or targeted gene replacement. Our results showed that co-cultivation of H. oryzae conidia with A. tumefaciens in the presence of acetosyringone for 48 h at 22 °C could lead to a relatively highest frequency of transformation, and 200 μM acetosyringone (AS) pre-cultivation of A. tumefaciens is also suggested. ATMT-mediated knockout mutagenesis was accomplished with the gene-deletion cassettes using a yeast homologous recombination method with a yeast-Escherichia-Agrobacterium shuttle vector pKOHo. Using the ATMT-mediated knockout mutagenesis, we successfully deleted three genes of H. oryzae (HoATG5, HoATG7, and HoATG8), and then got the null mutants ΔHoatg5, ΔHoatg7, and ΔHoatg8. These results suggest that ATMT is an efficient tool for gene modification including randomly insertional mutagenesis and gene deletion mutagenesis in H. oryzae.}, }
@article {pmid26684730, year = {2016}, author = {Mordret, S and Romac, S and Henry, N and Colin, S and Carmichael, M and Berney, C and Audic, S and Richter, DJ and Pochon, X and de Vargas, C and Decelle, J}, title = {The symbiotic life of Symbiodinium in the open ocean within a new species of calcifying ciliate (Tiarina sp.).}, journal = {The ISME journal}, volume = {10}, number = {6}, pages = {1424-1436}, pmid = {26684730}, issn = {1751-7370}, mesh = {Animals ; *Biodiversity ; Biological Evolution ; Ciliophora/*genetics/physiology ; DNA Barcoding, Taxonomic ; DNA, Ribosomal/chemistry/genetics ; Dinoflagellida/*genetics/physiology ; Ecology ; Ecosystem ; Genotype ; Geography ; Haplotypes ; Metagenomics ; Oceans and Seas ; Phylogeny ; *Symbiosis ; }, abstract = {Symbiotic partnerships between heterotrophic hosts and intracellular microalgae are common in tropical and subtropical oligotrophic waters of benthic and pelagic marine habitats. The iconic example is the photosynthetic dinoflagellate genus Symbiodinium that establishes mutualistic symbioses with a wide diversity of benthic hosts, sustaining highly biodiverse reef ecosystems worldwide. Paradoxically, although various species of photosynthetic dinoflagellates are prevalent eukaryotic symbionts in pelagic waters, Symbiodinium has not yet been reported in symbiosis within oceanic plankton, despite its high propensity for the symbiotic lifestyle. Here we report a new pelagic photosymbiosis between a calcifying ciliate host and the microalga Symbiodinium in surface ocean waters. Confocal and scanning electron microscopy, together with an 18S rDNA-based phylogeny, showed that the host is a new ciliate species closely related to Tiarina fusus (Colepidae). Phylogenetic analyses of the endosymbionts based on the 28S rDNA gene revealed multiple novel closely related Symbiodinium clade A genotypes. A haplotype network using the high-resolution internal transcribed spacer-2 marker showed that these genotypes form eight divergent, biogeographically structured, subclade types that do not seem to associate with any benthic hosts. Ecological analyses using the Tara Oceans metabarcoding data set (V9 region of the 18S rDNA) and contextual oceanographic parameters showed a global distribution of the symbiotic partnership in nutrient-poor surface waters. The discovery of the symbiotic life of Symbiodinium in the open ocean provides new insights into the ecology and evolution of this pivotal microalga and raises new hypotheses about coastal pelagic connectivity.}, }
@article {pmid26675213, year = {2015}, author = {Templé, N and Richard, FJ}, title = {Intra-cellular bacterial infections affect learning and memory capacities of an invertebrate.}, journal = {Frontiers in zoology}, volume = {12}, number = {}, pages = {36}, pmid = {26675213}, issn = {1742-9994}, abstract = {BACKGROUND: How host manipulation by parasites evolves is fascinating but challenging evolutionary question remains. Many parasites share the capacity to manipulate host behavior increasing their transmission success. However, little is known about the learning and memory impact of parasites on their host. Wolbachia are widespread endosymbionts and infect most insect species. These bacteria are maternally transmitted and mainly alter the reproduction of hosts with weak virulence. We tested the impact of parasites (Wolbachia) on their host learning and memory capacities. To address this question we trained individuals to one direction with positive reinforcement. We compared performances between individual Wolbachia-free, Wolbachia naturally and Wolbachia artificially infected individuals.<br><br>RESULTS: We report that in the host parasite interaction (Armadillidium vulgare/Wolbachia) naturally infected individuals Wolbachia or transinfected adult with Wolbachia are less likely to learn and memorize the correct direction with social reinforcement compared to Wolbachia-free individuals.<br><br>CONCLUSIONS: Our results imply that Wolbachia impact in the central nervous system of their host altering the memory formation and maintenance. We conclude that host manipulation can affect cognitive processes decreasing host adaptation capacities.}, }
@article {pmid26667400, year = {2015}, author = {De Clerck, C and Fujiwara, A and Joncour, P and Léonard, S and Félix, ML and Francis, F and Jijakli, MH and Tsuchida, T and Massart, S}, title = {A metagenomic approach from aphid's hemolymph sheds light on the potential roles of co-existing endosymbionts.}, journal = {Microbiome}, volume = {3}, number = {}, pages = {63}, pmid = {26667400}, issn = {2049-2618}, mesh = {Animals ; Aphids/*microbiology/*physiology ; Babuvirus ; Buchnera/genetics/*physiology ; Genes, Bacterial ; Hemolymph/*microbiology/physiology ; High-Throughput Nucleotide Sequencing ; Metagenome ; *Metagenomics ; Musa ; Riboflavin/metabolism ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: Aphids are known to live in symbiosis with specific bacteria, called endosymbionts which can be classified as obligate or accessory. Buchnera aphidicola is generally the only obligatory symbiont present in aphids, supplying essential nutrients that are missing in the plants phloem to its host. Pentalonia nigronervosa is the main vector of the banana bunchy top virus, one of the most damageable viruses in banana. This aphid is carrying two symbionts: B. aphidicola (BPn) and Wolbachia sp. (wPn). The high occurrence of Wolbachia in the banana aphid raises questions about the role it plays in this insect. The goal of this study was to go further in the understanding of the role played by the two symbionts in P. nigronervosa. To do so, microinjection tests were made to see the effect of wPn elimination on the host, and then, high-throughput sequencing of the haemolymph was used to analyze the gene content of the symbionts.<br><br>RESULTS: We observed that the elimination of wPn systematically led to the death of aphids, suggesting that the bacterium could play a mutualistic role. In addition, we identify and annotate 587 and 250 genes for wPn and BPn, respectively, through high-throughput sequencing. Analysis of these genes suggests that the two bacteria are working together for the production of several essential nutrients. The most striking cases are for lysin and riboflavin which are usually provided by B. aphidicola alone to the host. In the banana aphid, the genes involved in the production pathways of these metabolites are shared between the two bacteria making them both essential for the survival of the aphid host.<br><br>CONCLUSIONS: Our results suggest that a co-obligatory symbiosis between B. aphidicola and Wolbachia occurs in the banana aphid, the two bacteria acting together to supply essential nutrients to the host. This is, to our knowledge, the first time Wolbachia is reported to play an essential role in aphids.}, }
@article {pmid26664683, year = {2015}, author = {Sontowski, R and Bernhard, D and Bleidorn, C and Schlegel, M and Gerth, M}, title = {Wolbachia distribution in selected beetle taxa characterized by PCR screens and MLST data.}, journal = {Ecology and evolution}, volume = {5}, number = {19}, pages = {4345-4353}, pmid = {26664683}, issn = {2045-7758}, abstract = {Wolbachia (Alphaproteobacteria) is an inherited endosymbiont of arthropods and filarial nematodes and was reported to be widespread across insect taxa. While Wolbachia's effects on host biology are not understood from most of these hosts, known Wolbachia-induced phenotypes cover a spectrum from obligate beneficial mutualism to reproductive manipulations and pathogenicity. Interestingly, data on Wolbachia within the most species-rich order of arthropods, the Coleoptera (beetles), are scarce. Therefore, we screened 128 species from seven beetle families (Buprestidae, Hydraenidae, Dytiscidae, Hydrophilidae, Gyrinidae, Haliplidae, and Noteridae) for the presence of Wolbachia. Our data show that, contrary to previous estimations, Wolbachia frequencies in beetles (31% overall) are comparable to the ones in other insects. In addition, we used Wolbachia MLST data and host phylogeny to explore the evolutionary history of Wolbachia strains from Hydraenidae, an aquatic lineage of beetles. Our data suggest that Wolbachia from Hydraenidae might be largely host genus specific and that Wolbachia strain phylogeny is not independent to that of its hosts. As this contrasts with most terrestrial Wolbachia-arthropod systems, one potential conclusion is that aquatic lifestyle of hosts may result in Wolbachia distribution patterns distinct from those of terrestrial hosts. Our data thus provide both insights into Wolbachia distribution among beetles in general and a first glimpse of Wolbachia distribution patterns among aquatic host lineages.}, }
@article {pmid26653035, year = {2015}, author = {Clayton, KA and Gall, CA and Mason, KL and Scoles, GA and Brayton, KA}, title = {The characterization and manipulation of the bacterial microbiome of the Rocky Mountain wood tick, Dermacentor andersoni.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {632}, pmid = {26653035}, issn = {1756-3305}, support = {T32 GM008336/GM/NIGMS NIH HHS/United States ; AI4405/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage ; Arachnid Vectors ; Bacteria/*classification/drug effects/*growth &amp; development ; Dermacentor/*microbiology/physiology ; Gastrointestinal Tract/microbiology ; High-Throughput Nucleotide Sequencing ; *Microbiota ; North America ; Reproduction ; Salivary Glands/microbiology ; Symbiosis ; Wood/parasitology ; }, abstract = {BACKGROUND: In North America, ticks are the most economically impactful vectors of human and animal pathogens. The Rocky Mountain wood tick, Dermacentor andersoni (Acari: Ixodidae), transmits Rickettsia rickettsii and Anaplasma marginale to humans and cattle, respectively. In recent years, studies have shown that symbiotic organisms are involved in a number of biochemical and physiological functions. Characterizing the bacterial microbiome of D. andersoni is a pivotal step towards understanding symbiont-host interactions.<br><br>FINDINGS: In this study, we have shown by high-throughput sequence analysis that the composition of endosymbionts in the midgut and salivary glands in adult ticks is dynamic over three generations. Four Proteobacteria genera, Rickettsia, Francisella, Arsenophonus, and Acinetobacter, were identified as predominant symbionts in these two tissues. Exposure to therapeutic doses of the broad-spectrum antibiotic, oxytetracycline, affected both proportions of predominant genera and significantly reduced reproductive fitness. Additionally, Acinetobacter, a free-living ubiquitous microbe, invaded the bacterial microbiome at different proportions based on antibiotic treatment status suggesting that microbiome composition may have a role in susceptibility to environmental contaminants.<br><br>CONCLUSIONS: This study characterized the bacterial microbiome in D. andersoni and determined the generational variability within this tick. Furthermore, this study confirmed that microbiome manipulation is associated with tick fitness and may be a potential method for biocontrol.}, }
@article {pmid26650541, year = {2015}, author = {Hunter, DJ and Torkelson, JL and Bodnar, J and Mortazavi, B and Laurent, T and Deason, J and Thephavongsa, K and Zhong, J}, title = {The Rickettsia Endosymbiont of Ixodes pacificus Contains All the Genes of De Novo Folate Biosynthesis.}, journal = {PloS one}, volume = {10}, number = {12}, pages = {e0144552}, pmid = {26650541}, issn = {1932-6203}, support = {R15 AI099902/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Computational Biology ; Folic Acid/*biosynthesis ; Ixodes/genetics/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; Rickettsia/*genetics ; Rickettsia Infections/*genetics/microbiology ; Symbiosis/*genetics ; Tick Infestations/*genetics/microbiology ; }, abstract = {Ticks and other arthropods often are hosts to nutrient providing bacterial endosymbionts, which contribute to their host's fitness by supplying nutrients such as vitamins and amino acids. It has been detected, in our lab, that Ixodes pacificus is host to Rickettsia species phylotype G021. This endosymbiont is predominantly present, and 100% maternally transmitted in I. pacificus. To study roles of phylotype G021 in I. pacificus, bioinformatic and molecular approaches were carried out. MUMmer genome alignments of whole genome sequence of I. scapularis, a close relative to I. pacificus, against completely sequenced genomes of R. bellii OSU85-389, R. conorii, and R. felis, identified 8,190 unique sequences that are homologous to Rickettsia sequences in the NCBI Trace Archive. MetaCyc metabolic reconstructions revealed that all folate gene orthologues (folA, folC, folE, folKP, ptpS) required for de novo folate biosynthesis are present in the genome of Rickettsia buchneri in I. scapularis. To examine the metabolic capability of phylotype G021 in I. pacificus, genes of the folate biosynthesis pathway of the bacterium were PCR amplified using degenerate primers. BLAST searches identified that nucleotide sequences of the folA, folC, folE, folKP, and ptpS genes possess 98.6%, 98.8%, 98.9%, 98.5% and 99.0% identity respectively to the corresponding genes of Rickettsia buchneri. Phylogenetic tree constructions show that the folate genes of phylotype G021 and homologous genes from various Rickettsia species are monophyletic. This study has shown that all folate genes exist in the genome of Rickettsia species phylotype G021 and that this bacterium has the genetic capability for de novo folate synthesis.}, }
@article {pmid26639580, year = {2015}, author = {Hirakata, Y and Oshiki, M and Kuroda, K and Hatamoto, M and Kubota, K and Yamaguchi, T and Harada, H and Araki, N}, title = {Identification and Detection of Prokaryotic Symbionts in the Ciliate Metopus from Anaerobic Granular Sludge.}, journal = {Microbes and environments}, volume = {30}, number = {4}, pages = {335-338}, pmid = {26639580}, issn = {1347-4405}, mesh = {*Biota ; Ciliophora/*microbiology ; Clostridium/classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Archaeal/chemistry/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; In Situ Hybridization, Fluorescence ; Methanomicrobiales/classification/genetics/*isolation &amp; purification ; Microbial Consortia ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sewage/*microbiology ; *Symbiosis ; }, abstract = {The aim of the present study was to investigate the prokaryotic community structure of the anaerobic ciliate, Metopus sp. using rRNA sequencing, fluorescence in situ hybridization (FISH), and transmission electron microscopy (TEM). Metopus sp. was physically separated from anaerobic granular sludge in a domestic wastewater treatment plant and anoxically cultivated for 7 d. 16S rRNA gene sequences from the prokaryotes Methanoregula boonei and Clostridium aminobutyricum were abundantly detected in Metopus ciliates. The FISH analysis using the oligonucleotide probes Mg1200b and Cla568 demonstrated that these prokaryotes were localized within Metopus cells. These results identify M. boonei- and C. aminobutyricum-like prokaryotes as novel endosymbionts of Metopus ciliates.}, }
@article {pmid26632455, year = {2015}, author = {Haribal, M and Jander, G}, title = {Stable isotope studies reveal pathways for the incorporation of non-essential amino acids in Acyrthosiphon pisum (pea aphids).}, journal = {The Journal of experimental biology}, volume = {218}, number = {Pt 23}, pages = {3797-3806}, doi = {10.1242/jeb.129189}, pmid = {26632455}, issn = {1477-9145}, mesh = {Amino Acids/*metabolism ; Animals ; Aphids/*metabolism ; Asparagine/metabolism ; Aspartic Acid/metabolism ; Buchnera/metabolism ; Carbon Isotopes ; Glutamic Acid/metabolism ; Glutamine/metabolism ; Nitrogen/metabolism ; Nitrogen Isotopes ; Symbiosis ; }, abstract = {Plant roots incorporate inorganic nitrogen into the amino acids glutamine, glutamic acid, asparagine and aspartic acid, which together serve as the primary metabolites of nitrogen transport to other tissues. Given the preponderance of these four amino acids, phloem sap is a nutritionally unbalanced diet for phloem-feeding insects. Therefore, aphids and other phloem feeders typically rely on microbial symbionts for the synthesis of essential amino acids. To investigate the metabolism of the four main transport amino acids by the pea aphid (Acyrthosiphon pisum), and its Buchnera aphidicola endosymbionts, aphids were fed defined diets with stable isotope-labeled glutamine, glutamic acid, asparagine or aspartic acid (U-(13)C, U-(15)N; U-(15)N; α-(15)N; or γ-(15)N). The metabolic fate of the dietary (15)N and (13)C was traced using gas chromatography-mass spectrometry (GC-MS). Nitrogen was the major contributor to the observed amino acid isotopomers with one additional unit mass (M+1). However, there was differential incorporation, with the amine nitrogen of asparagine being incorporated into other amino acids more efficiently than the amide nitrogen. Higher isotopomers (M+2, M+3 and M+4) indicated the incorporation of varying numbers of (13)C atoms into essential amino acids. GC-MS assays also showed that, even with an excess of dietary labeled glutamine, glutamic acid, asparagine or aspartic acid, the overall content of these amino acids in aphid bodies was mostly the product of catabolism of dietary amino acids and subsequent re-synthesis within the aphids. Thus, these predominant dietary amino acids are not passed directly to Buchnera endosymbionts for synthesis of essential amino acids, but are rather are produced de novo, most likely by endogenous aphid enzymes.}, }
@article {pmid26631376, year = {2015}, author = {Comandatore, F and Cordaux, R and Bandi, C and Blaxter, M and Darby, A and Makepeace, BL and Montagna, M and Sassera, D}, title = {Supergroup C Wolbachia, mutualist symbionts of filarial nematodes, have a distinct genome structure.}, journal = {Open biology}, volume = {5}, number = {12}, pages = {150099}, pmid = {26631376}, issn = {2046-2441}, support = {095831//Wellcome Trust/United Kingdom ; G0900740/MRC_/Medical Research Council/United Kingdom ; MR/K001744/1/MRC_/Medical Research Council/United Kingdom ; //Cancer Research UK/United Kingdom ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Filarioidea/*microbiology ; Genomics ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {Wolbachia pipientis is possibly the most widespread endosymbiont of arthropods and nematodes. While all Wolbachia strains have historically been defined as a single species, 16 monophyletic clusters of diversity (called supergroups) have been described. Different supergroups have distinct host ranges and symbiotic relationships, ranging from mutualism to reproductive manipulation. In filarial nematodes, which include parasites responsible for major diseases of humans (such as Onchocerca volvulus, agent of river blindness) and companion animals (Dirofilaria immitis, the dog heartworm), Wolbachia has an obligate mutualist role and is the target of new treatment regimens. Here, we compare the genomes of eight Wolbachia strains, spanning the diversity of the major supergroups (A-F), analysing synteny, transposable element content, GC skew and gene loss or gain. We detected genomic features that differ between Wolbachia supergroups, most notably in the C and D clades from filarial nematodes. In particular, strains from supergroup C (symbionts of O. volvulus and D. immitis) present a pattern of GC skew, conserved synteny and lack of transposable elements, unique in the Wolbachia genus. These features could be the consequence of a distinct symbiotic relationship between C Wolbachia strains and their hosts, highlighting underappreciated differences between the mutualistic supergroups found within filarial nematodes.}, }
@article {pmid26628723, year = {2015}, author = {David, V and Flegontov, P and Gerasimov, E and Tanifuji, G and Hashimi, H and Logacheva, MD and Maruyama, S and Onodera, NT and Gray, MW and Archibald, JM and Lukeš, J}, title = {Gene Loss and Error-Prone RNA Editing in the Mitochondrion of Perkinsela, an Endosymbiotic Kinetoplastid.}, journal = {mBio}, volume = {6}, number = {6}, pages = {e01498-15}, pmid = {26628723}, issn = {2150-7511}, mesh = {Amoebozoa/parasitology ; Computational Biology ; DNA, Mitochondrial/chemistry/genetics ; *Gene Deletion ; High-Throughput Nucleotide Sequencing ; Kinetoplastida/*genetics/growth &amp; development ; Mitochondria/*genetics ; *RNA Editing ; Sequence Analysis, DNA ; }, abstract = {UNLABELLED: Perkinsela is an enigmatic early-branching kinetoplastid protist that lives as an obligate endosymbiont inside Paramoeba (Amoebozoa). We have sequenced the highly reduced mitochondrial genome of Perkinsela, which possesses only six protein-coding genes (cox1, cox2, cox3, cob, atp6, and rps12), despite the fact that the organelle itself contains more DNA than is present in either the host or endosymbiont nuclear genomes. An in silico analysis of two Perkinsela strains showed that mitochondrial RNA editing and processing machineries typical of kinetoplastid flagellates are generally conserved, and all mitochondrial transcripts undergo U-insertion/deletion editing. Canonical kinetoplastid mitochondrial ribosomes are also present. We have developed software tools for accurate and exhaustive mapping of transcriptome sequencing (RNA-seq) reads with extensive U-insertions/deletions, which allows detailed investigation of RNA editing via deep sequencing. With these methods, we show that up to 50% of reads for a given edited region contain errors of the editing system or, less likely, correspond to alternatively edited transcripts.<br><br>IMPORTANCE: Uridine insertion/deletion-type RNA editing, which occurs in the mitochondrion of kinetoplastid protists, has been well-studied in the model parasite genera Trypanosoma, Leishmania, and Crithidia. Perkinsela provides a unique opportunity to broaden our knowledge of RNA editing machinery from an evolutionary perspective, as it represents the earliest kinetoplastid branch and is an obligatory endosymbiont with extensive reductive trends. Interestingly, up to 50% of mitochondrial transcripts in Perkinsela contain errors. Our study was complemented by use of newly developed software designed for accurate mapping of extensively edited RNA-seq reads obtained by deep sequencing.}, }
@article {pmid26625979, year = {2016}, author = {Iwai, S and Fujiwara, K and Tamura, T}, title = {Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.}, journal = {Environmental microbiology}, volume = {18}, number = {8}, pages = {2435-2445}, doi = {10.1111/1462-2920.13140}, pmid = {26625979}, issn = {1462-2920}, mesh = {Cell Division/physiology ; Chlorella/cytology/*growth &amp; development ; Light ; *Models, Theoretical ; Paramecium/*parasitology/physiology ; Phototrophic Processes/*physiology ; Population Density ; Population Dynamics ; Symbiosis/*physiology ; }, abstract = {Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts.}, }
@article {pmid26617602, year = {2015}, author = {Silva, FJ and Santos-Garcia, D}, title = {Slow and Fast Evolving Endosymbiont Lineages: Positive Correlation between the Rates of Synonymous and Non-Synonymous Substitution.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {1279}, pmid = {26617602}, issn = {1664-302X}, abstract = {The availability of complete genome sequences of bacterial endosymbionts with strict vertical transmission to the host progeny opens the possibility to estimate molecular evolutionary rates in different lineages and understand the main biological mechanisms influencing these rates. We have compared the rates of evolution for non-synonymous and synonymous substitutions in nine bacterial endosymbiont lineages, belonging to four clades (Baumannia, Blochmannia, Portiera, and Sulcia). The main results are the observation of a positive correlation between both rates with differences among lineages of up to three orders of magnitude and that the substitution rates decrease over long endosymbioses. To explain these results we propose three mechanisms. The first, variations in the efficiencies of DNA replication and DNA repair systems, is unable to explain most of the observed differences. The second, variations in the generation time among bacterial lineages, would be based on the accumulation of fewer DNA replication errors per unit time in organisms with longer generation times. The third, a potential control of the endosymbiont DNA replication and repair systems through the transfer of nuclear-encoded proteins, could explain the lower rates in long-term obligate endosymbionts. Because the preservation of the genomic integrity of the harbored obligate endosymbiont would be advantageous for the insect host, biological mechanisms producing a general reduction in the rates of nucleotide substitution per unit of time would be a target for natural selection.}, }
@article {pmid26609691, year = {2015}, author = {Elsa, J and Duron, O and Séverine, B and González-Acuña, D and Sidi-Boumedine, K}, title = {Molecular methods routinely used to detect Coxiella burnetii in ticks cross-react with Coxiella-like bacteria.}, journal = {Infection ecology &amp; epidemiology}, volume = {5}, number = {}, pages = {29230}, pmid = {26609691}, issn = {2000-8686}, abstract = {BACKGROUND: Q fever is a widespread zoonotic disease caused by Coxiella burnetii. Ticks may act as vectors, and many epidemiological studies aim to assess C. burnetii prevalence in ticks. Because ticks may also be infected with Coxiella-like bacteria, screening tools that differentiate between C. burnetii and Coxiella-like bacteria are essential.<br><br>METHODS: In this study, we screened tick specimens from 10 species (Ornithodoros rostratus, O. peruvianus, O. capensis, Ixodes ricinus, Rhipicephalus annulatus, R. decoloratus, R. geigy, O. sonrai, O. occidentalis, and Amblyomma cajennense) known to harbor specific Coxiella-like bacteria, by using quantitative PCR primers usually considered to be specific for C. burnetii and targeting, respectively, the IS1111, icd, scvA, p1, and GroEL/htpB genes.<br><br>RESULTS: We found that some Coxiella-like bacteria, belonging to clades A and C, yield positive PCR results when screened with primers initially believed to be C. burnetii-specific.<br><br>CONCLUSIONS: These results suggest that PCR-based surveys that aim to detect C. burnetii in ticks by using currently available methods must be interpreted with caution if the amplified products cannot be sequenced. Future molecular methods that aim at detecting C. burnetii need to take into account the possibility that cross-reactions may exist with Coxiella-like bacteria.}, }
@article {pmid26608058, year = {2015}, author = {Kobayashi, Y and Takusagawa, M and Harada, N and Fukao, Y and Yamaoka, S and Kohchi, T and Hori, K and Ohta, H and Shikanai, T and Nishimura, Y}, title = {Eukaryotic Components Remodeled Chloroplast Nucleoid Organization during the Green Plant Evolution.}, journal = {Genome biology and evolution}, volume = {8}, number = {1}, pages = {1-16}, pmid = {26608058}, issn = {1759-6653}, mesh = {Chlamydomonas reinhardtii/genetics ; Chloroplast Proteins/genetics/metabolism ; *Evolution, Molecular ; *Genome, Chloroplast ; Marchantia/genetics ; }, abstract = {Chloroplast (cp) DNA is thought to originate from the ancestral endosymbiont genome and is compacted to form nucleoprotein complexes, cp nucleoids. The structure of cp nucleoids is ubiquitously observed in diverse plants from unicellular algae to flowering plants and is believed to be a multifunctional platform for various processes, including cpDNA replication, repair/recombination, transcription, and inheritance. Despite its fundamental functions, the protein composition for cp nucleoids in flowering plants was suggested to be divergent from those of bacteria and algae, but the evolutionary process remains elusive. In this research, we aimed to reveal the evolutionary history of cp nucleoid organization by analyzing the key organisms representing the three evolutionary stages of eukaryotic phototrophs: the chlorophyte alga Chlamydomonas reinhardtii, the charophyte alga Klebsormidium flaccidum, and the most basal land plant Marchantia polymorpha. To clarify the core cp nucleoid proteins in C. reinhardtii, we performed an LC-MS/MS analysis using highly purified cp nucleoid fractions and identified a novel SAP domain-containing protein with a eukaryotic origin as a constitutive core component. Then, homologous genes for cp nucleoid proteins were searched for in C. reinhardtii, K. flaccidum, and M. polymorpha using the genome databases, and their intracellular localizations and DNA binding activities were investigated by cell biological/biochemical analyses. Based on these results, we propose a model that recurrent modification of cp nucleoid organization by eukaryotic factors originally related to chromatin organization might have been the driving force for the diversification of cp nucleoids since the early stage of green plant evolution.}, }
@article {pmid26605067, year = {2015}, author = {Nakano, H}, title = {What is Xenoturbella?.}, journal = {Zoological letters}, volume = {1}, number = {}, pages = {22}, pmid = {26605067}, issn = {2056-306X}, abstract = {Xenoturbella is a strange marine worm that can be collected regularly only off the west coast of Sweden. Due to its simple morphology, which lacks a centralized nervous system, coelom, anus, or reproductive organs, its phylogenetic position has long remained obscure. Recent phylogenomic analyses suggest it forms a new phylum, Xenacoelomorpha, together with the Acoelomorpha, but the position of the phylum remains undecided, either as a deuterostome or an early branching bilaterian. Developmental stages exhibit many phylogenetically decisive characters in various animal species, but have remained a mystery for Xenoturbella until recently. Observations of its development showed it has direct development with a very short and simple swimming stage, and that it lacks a feeding larva. Asexual reproduction has never been reported. It has been suggested that Xenoturbella feeds specifically on bivalves, but it still remains unknown whether it feeds on sperm, eggs, larvae, juveniles, carcass, mucus, or feces of bivalves, and direct observations of Xenoturbella feeding on bivalves have not been reported. Endosymbiont bacteria have been found, and their functions are being investigated. The evolutionary scenario of this taxon remains the subject of debate, and our understanding will depend largely on determining its phylogeny. Thus, although recent studies have uncovered many new and crucial facts regarding Xenoturbella, some fundamental biological information, such as phylogeny, complete life cycle, and genome, remain unsolved. Further research on the well-studied Swedish Xenoturbella bocki, as well as the discovery of new species elsewhere, are necessary if we are to more fully understand the nature of Xenoturbella.}, }
@article {pmid26603858, year = {2016}, author = {Zytynska, SE and Meyer, ST and Sturm, S and Ullmann, W and Mehrparvar, M and Weisser, WW}, title = {Secondary bacterial symbiont community in aphids responds to plant diversity.}, journal = {Oecologia}, volume = {180}, number = {3}, pages = {735-747}, pmid = {26603858}, issn = {1432-1939}, mesh = {Animals ; Aphids/*microbiology/*physiology ; *Biodiversity ; Plants/microbiology/*parasitology ; Species Specificity ; Symbiosis ; }, abstract = {Biodiversity is important for ecosystem functioning and biotic interactions. In experimental grasslands, increasing plant species richness is known to increase the diversity of associated herbivores and their predators. If these interactions can also involve endosymbionts that reside within a plant or animal host is currently unknown. In plant-feeding aphids, secondary bacterial symbionts can have strong fitness effects on the host, e.g. resistance to natural enemies or fungal pathogens. We examined the secondary symbiont community in three species of aphid, each feeding on a unique host plant across experimental plots that varied in plant species richness. Aphids were collected in May and June, and the symbiont community identified using species-specific PCR assays. Aphis fabae aphids were found to host six different symbiont species with individual aphids co-hosting up to four symbionts. Uroleucon jaceae and Macrosiphum rosae hosted two and three symbiont species, respectively. We found that, at the aphid population level, increasing plant species richness increased the diversity of the aphid symbiont community, whereas at the individual aphid level, the opposite was found. These effects are potentially driven by varying selective pressures across different plant communities of varying diversities, mediated by defensive protection responses and a changing cost-benefit trade-off to the aphid for hosting multiple secondary symbionts. Our work extends documented effects of plant diversity beyond visible biotic interactions to changes in endosymbiont communities, with potentially far-reaching consequences to related ecosystem processes.}, }
@article {pmid26581105, year = {2015}, author = {Taboada, S and Riesgo, A and Bas, M and Arnedo, MA and Cristobo, J and Rouse, GW and Avila, C}, title = {Bone-Eating Worms Spread: Insights into Shallow-Water Osedax (Annelida, Siboglinidae) from Antarctic, Subantarctic, and Mediterranean Waters.}, journal = {PloS one}, volume = {10}, number = {11}, pages = {e0140341}, pmid = {26581105}, issn = {1932-6203}, mesh = {Animals ; Annelida/classification/*genetics/microbiology ; Aquatic Organisms ; Bayes Theorem ; *Biological Evolution ; Bone and Bones/chemistry ; Ecosystem ; Electron Transport Complex IV/genetics ; Female ; Gammaproteobacteria/physiology ; Histones/genetics ; Male ; Oceans and Seas ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; RNA, Ribosomal, 28S/genetics ; Symbiosis ; Vertebrates ; }, abstract = {Osedax, commonly known as bone-eating worms, are unusual marine annelids belonging to Siboglinidae and represent a remarkable example of evolutionary adaptation to a specialized habitat, namely sunken vertebrate bones. Usually, females of these animals live anchored inside bone owing to a ramified root system from an ovisac, and obtain nutrition via symbiosis with Oceanospirillales gamma-proteobacteria. Since their discovery, 26 Osedax operational taxonomic units (OTUs) have been reported from a wide bathymetric range in the Pacific, the North Atlantic, and the Southern Ocean. Using experimentally deployed and naturally occurring bones we report here the presence of Osedax deceptionensis at very shallow-waters in Deception Island (type locality; Antarctica) and at moderate depths near South Georgia Island (Subantarctic). We present molecular evidence in a new phylogenetic analysis based on five concatenated genes (28S rDNA, Histone H3, 18S rDNA, 16S rDNA, and cytochrome c oxidase I-COI-), using Maximum Likelihood and Bayesian inference, supporting the placement of O. deceptionensis as a separate lineage (Clade VI) although its position still remains uncertain. This phylogenetic analysis includes a new unnamed species (O. 'mediterranea') recently discovered in the shallow-water Mediterranean Sea belonging to Osedax Clade I. A timeframe of the diversification of Osedax inferred using a Bayesian framework further suggests that Osedax diverged from other siboglinids during the Middle Cretaceous (ca. 108 Ma) and also indicates that the most recent common ancestor of Osedax extant lineages dates to the Late Cretaceous (ca. 74.8 Ma) concomitantly with large marine reptiles and teleost fishes. We also provide a phylogenetic framework that assigns newly-sequenced Osedax endosymbionts of O. deceptionensis and O. 'mediterranea' to ribospecies Rs1. Molecular analysis for O. deceptionensis also includes a COI-based haplotype network indicating that individuals from Deception Island and the South Georgia Island (ca. 1,600 km apart) are clearly the same species, confirming the well-developed dispersal capabilities reported in other congeneric taxa. In addition, we include a complete description of living features and morphological characters (including scanning and transmission electron microscopy) of O. deceptionensis, a species originally described from a single mature female, and compare it to information available for other congeneric OTUs.}, }
@article {pmid26580079, year = {2015}, author = {Ramsey, JS and Johnson, RS and Hoki, JS and Kruse, A and Mahoney, J and Hilf, ME and Hunter, WB and Hall, DG and Schroeder, FC and MacCoss, MJ and Cilia, M}, title = {Metabolic Interplay between the Asian Citrus Psyllid and Its Profftella Symbiont: An Achilles' Heel of the Citrus Greening Insect Vector.}, journal = {PloS one}, volume = {10}, number = {11}, pages = {e0140826}, pmid = {26580079}, issn = {1932-6203}, mesh = {Animals ; Bacterial Proteins/*genetics/metabolism ; Citrus/*microbiology ; Gene Expression Regulation ; Hemiptera/genetics/immunology/*microbiology ; Insect Proteins/*genetics/metabolism ; Metabolic Networks and Pathways ; Molecular Sequence Annotation ; Plant Diseases/microbiology ; Polyketides/*metabolism ; Proteome/*genetics/metabolism ; Rhizobiaceae/physiology ; Symbiosis ; }, abstract = {'Candidatus Liberibacter asiaticus' (CLas), the bacterial pathogen associated with citrus greening disease, is transmitted by Diaphorina citri, the Asian citrus psyllid. Interactions among D. citri and its microbial endosymbionts, including 'Candidatus Profftella armatura', are likely to impact transmission of CLas. We used quantitative mass spectrometry to compare the proteomes of CLas(+) and CLas(-) populations of D. citri, and found that proteins involved in polyketide biosynthesis by the endosymbiont Profftella were up-regulated in CLas(+) insects. Mass spectrometry analysis of the Profftella polyketide diaphorin in D. citri metabolite extracts revealed the presence of a novel diaphorin-related polyketide and the ratio of these two polyketides was changed in CLas(+) insects. Insect proteins differentially expressed between CLas(+) and CLas(-) D. citri included defense and immunity proteins, proteins involved in energy storage and utilization, and proteins involved in endocytosis, cellular adhesion, and cytoskeletal remodeling which are associated with microbial invasion of host cells. Insight into the metabolic interdependence between the insect vector, its endosymbionts, and the citrus greening pathogen reveals novel opportunities for control of this disease, which is currently having a devastating impact on citrus production worldwide.}, }
@article {pmid26579107, year = {2015}, author = {Zug, R and Hammerstein, P}, title = {Wolbachia and the insect immune system: what reactive oxygen species can tell us about the mechanisms of Wolbachia-host interactions.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {1201}, pmid = {26579107}, issn = {1664-302X}, abstract = {Wolbachia are intracellular bacteria that infect a vast range of arthropod species, making them one of the most prevalent endosymbionts in the world. Wolbachia's stunning evolutionary success is mostly due to their reproductive parasitism but also to mutualistic effects such as increased host fecundity or protection against pathogens. However, the mechanisms underlying Wolbachia phenotypes, both parasitic and mutualistic, are only poorly understood. Moreover, it is unclear how the insect immune system is involved in these phenotypes and why it is not more successful in eliminating the bacteria. Here we argue that reactive oxygen species (ROS) are likely to be key in elucidating these issues. ROS are essential players in the insect immune system, and Wolbachia infection can affect ROS levels in the host. Based on recent findings, we elaborate a hypothesis that considers the different effects of Wolbachia on the oxidative environment in novel vs. native hosts. We propose that newly introduced Wolbachia trigger an immune response and cause oxidative stress, whereas in coevolved symbioses, infection is not associated with oxidative stress, but rather with restored redox homeostasis. Redox homeostasis can be restored in different ways, depending on whether Wolbachia or the host is in charge. This hypothesis offers a mechanistic explanation for several of the observed Wolbachia phenotypes.}, }
@article {pmid26577075, year = {2015}, author = {Speijer, D}, title = {Birth of the eukaryotes by a set of reactive innovations: New insights force us to relinquish gradual models.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {37}, number = {12}, pages = {1268-1276}, doi = {10.1002/bies.201500107}, pmid = {26577075}, issn = {1521-1878}, mesh = {Adenosine Triphosphate/metabolism ; Archaea/metabolism ; Eukaryota/*metabolism/*physiology ; Mitochondria/metabolism ; Proteome/metabolism ; Reactive Oxygen Species/metabolism ; }, abstract = {Of two contending models for eukaryotic evolution the "archezoan" has an amitochondriate eukaryote take up an endosymbiont, while "symbiogenesis" states that an Archaeon became a eukaryote as the result of this uptake. If so, organelle formation resulting from new engulfments is simplified by the primordial symbiogenesis, and less informative regarding the bacterium-to-mitochondrion conversion. Gradualist archezoan visions still permeate evolutionary thinking, but are much less likely than symbiogenesis. Genuine amitochondriate eukaryotes have never been found and rapid, explosive adaptive periods characteristic of symbiogenetic models explain this. Mitochondrial proteomes, encoded by genes of "eukaryotic origin" not easily linked to host or endosymbiont, can be understood in light of rapid adjustments to new evolutionary pressures. Symbiogenesis allows "expensive" eukaryotic inventions via efficient ATP generation by nascent mitochondria. However, efficient ATP production equals enhanced toxic internal ROS formation. The synergistic combination of these two driving forces gave rise to the rapid evolution of eukaryotes. Also watch the Video Abstract.}, }
@article {pmid26576934, year = {2016}, author = {Tantowijoyo, W and Arguni, E and Johnson, P and Budiwati, N and Nurhayati, PI and Fitriana, I and Wardana, S and Ardiansyah, H and Turley, AP and Ryan, P and O'Neill, SL and Hoffmann, AA}, title = {Spatial and Temporal Variation in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Numbers in the Yogyakarta Area of Java, Indonesia, With Implications for Wolbachia Releases.}, journal = {Journal of medical entomology}, volume = {53}, number = {1}, pages = {188-198}, doi = {10.1093/jme/tjv180}, pmid = {26576934}, issn = {0022-2585}, mesh = {*Aedes ; Animals ; Indonesia ; Pest Control, Biological ; Population Density ; Population Dynamics ; Wolbachia ; }, abstract = {of mosquito vector populations, particularly through Wolbachia endosymbionts. The success of these strategies depends on understanding the dynamics of vector populations. In preparation for Wolbachia releases around Yogyakarta, we have studied Aedes populations in five hamlets. Adult monitoring with BioGent- Sentinel (BG-S) traps indicated that hamlet populations had different dynamics across the year; while there was an increase in Aedes aegypti (L.) and Aedes albopictus (Skuse) numbers in the wet season, species abundance remained relatively stable in some hamlets but changed markedly (>2 fold) in others. Local rainfall a month prior to monitoring partly predicted numbers of Ae. aegypti but not Ae. albopictus. Site differences in population size indicated by BG-S traps were also evident in ovitrap data. Egg or larval collections with ovitraps repeated at the same location suggested spatial autocorrelation (<250 m) in the areas of the hamlets where Ae. aegypti numbers were high. Overall, there was a weak negative association (r<0.43) between Ae. aegypti and Ae. albopictus numbers in ovitraps when averaged across collections. Ae. albopictus numbers in ovitraps and BG-S traps were positively correlated with vegetation around areas where traps were placed, while Ae. aegypti were negatively correlated with this feature. These data inform intervention strategies by defining periods when mosquito densities are high, highlighting the importance of local site characteristics on populations, and suggesting relatively weak interactions between Ae. aegypti and Ae. albopictus. They also indicate local areas within hamlets where consistently high mosquito densities may influence Wolbachia invasions and other interventions.}, }
@article {pmid26573831, year = {2016}, author = {Duron, O and Cremaschi, J and McCoy, KD}, title = {The High Diversity and Global Distribution of the Intracellular Bacterium Rickettsiella in the Polar Seabird Tick Ixodes uriae.}, journal = {Microbial ecology}, volume = {71}, number = {3}, pages = {761-770}, pmid = {26573831}, issn = {1432-184X}, mesh = {Animals ; *Biodiversity ; Bird Diseases/*microbiology/*parasitology ; Birds/microbiology/parasitology ; Coxiellaceae/classification/genetics/*isolation &amp; purification ; Female ; Ixodes/*microbiology ; Male ; Phylogeny ; }, abstract = {Obligate intracellular bacteria of the Rickettsiella genus are emerging as both widespread and biologically diverse in arthropods. Some Rickettsiella strains are highly virulent entomopathogenic agents, whereas others are maternally inherited endosymbionts exerting very subtle manipulations on host phenotype to promote their own spread. Recently, a variety of Rickettsiella strains have been reported from ticks, but their biology is entirely unknown. In the present study, we examined the incidence and diversity of Rickettsiella in 11 geographically distinct populations of the polar seabird tick Ixodes uriae. We found Rickettsiella in most tick populations with a prevalence ranging from 3 to 24 %. 16S ribosomal RNA (rRNA) and GroEL gene sequences revealed an unexpected diversity of Rickettsiella, with 12 genetically distinct Rickettsiella strains present in populations of I. uriae. Phylogenetic investigations further revealed that these Rickettsiella strains do not cluster within a tick-specific clade but rather exhibit distinct evolutionary origins demonstrating frequent horizontal transfers between distantly related arthropod species. Tick rearing further showed that Rickettsiella are present in eggs laid by infected females with no evidence of abortive development. Using this data set, we discuss the potential biological significance of Rickettsiella in seabird ticks. Most notably, we suggest that these organisms may not be pathogenic forms but rather use more subtle adaptive strategies to persist within tick populations.}, }
@article {pmid26568615, year = {2016}, author = {Zheng, H and Dietrich, C and Hongoh, Y and Brune, A}, title = {Restriction-Modification Systems as Mobile Genetic Elements in the Evolution of an Intracellular Symbiont.}, journal = {Molecular biology and evolution}, volume = {33}, number = {3}, pages = {721-725}, pmid = {26568615}, issn = {1537-1719}, mesh = {*Biological Evolution ; CRISPR-Cas Systems ; *DNA Restriction-Modification Enzymes ; Gene Rearrangement ; Genome ; Genomics ; *Interspersed Repetitive Sequences ; *Symbiosis/genetics ; }, abstract = {Long-term vertical transmission of intracellular bacteria causes massive genomic erosion and results in extremely small genomes, particularly in ancient symbionts. Genome reduction is typically preceded by the accumulation of pseudogenes and proliferation of mobile genetic elements, which are responsible for chromosome rearrangements during the initial stage of endosymbiosis. We compared the genomes of an endosymbiont of termite gut flagellates, "Candidatus Endomicrobium trichonymphae," and its free-living relative Endomicrobium proavitum and discovered many remnants of restriction-modification (R-M) systems that are consistently associated with genome rearrangements in the endosymbiont genome. The rearrangements include apparent insertions, transpositions, and the duplication of a genomic region; there was no evidence of transposon structures or other mobile elements. Our study reveals a so far unrecognized mechanism for genome rearrangements in intracellular symbionts and sheds new light on the general role of R-M systems in genome evolution.}, }
@article {pmid26567303, year = {2016}, author = {Hess, S and Suthaus, A and Melkonian, M}, title = {"Candidatus Finniella" (Rickettsiales, Alphaproteobacteria), Novel Endosymbionts of Viridiraptorid Amoeboflagellates (Cercozoa, Rhizaria).}, journal = {Applied and environmental microbiology}, volume = {82}, number = {2}, pages = {659-670}, pmid = {26567303}, issn = {1098-5336}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification/*physiology ; Cercozoa/*microbiology/physiology ; Cytoplasm/microbiology ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; }, abstract = {The Rickettsiales (Alphaproteobacteria) are obligate intracellular bacteria that colonize a wide range of eukaryotic hosts, including diverse metazoa and protists. Here, we characterize rickettsial endosymbionts discovered in the cytoplasm of the algivorous amoeboflagellates Viridiraptor invadens and Orciraptor agilis (Viridiraptoridae, Cercozoa, Rhizaria), supplying evidence of free-living, phagotrophic members of the Cercozoa serving as hosts for Rickettsiales. According to 16S rRNA gene phylogenies, the bacteria represent two closely related but distinct genotypes within a deep-branching rickettsial clade, which contains the genera "Candidatus Odyssella," "Candidatus Paracaedibacter," and "Candidatus Captivus." Using the full-cycle rRNA approach, we detected the novel bacteria in four of nine viridiraptorid strains tested. Furthermore, two specific oligonucleotide probes with a single-nucleotide-difference discriminated both bacterial genotypes by fluorescence in situ hybridization (FISH). We establish the candidate species "Candidatus Finniella inopinata" (found in Viridiraptor invadens) and "Candidatus Finniella lucida" (found in Orciraptor agilis) for the novel bacteria and propose a new, provisional family of Rickettsiales, "Candidatus Paracaedibacteraceae."}, }
@article {pmid26566476, year = {2015}, author = {Tang, VH and Stewart, GA and Chang, BJ}, title = {House dust mites possess a polymorphic, single domain putative peptidoglycan d,l endopeptidase belonging to the NlpC/P60 Superfamily.}, journal = {FEBS open bio}, volume = {5}, number = {}, pages = {813-823}, pmid = {26566476}, issn = {2211-5463}, abstract = {A 14 kDa protein homologous to the γ-d-glutamyl-l-diamino acid endopeptidase members of the NlpC/P60 Superfamily has been described in Dermatophagoides pteronyssinus and Dermatophagoides farinae but it is not clear whether other species produce homologues. Bioinformatics revealed homologous genes in other Sarcopteformes mite species (Psoroptes ovis and Blomia tropicalis) but not in Tetranychus urticae and Metaseiulus occidentalis. The degrees of identity (similarity) between the D. pteronyssinus mature protein and those from D. farinae, P. ovis and B. tropicalis were 82% (96%), 77% (93%) and 61% (82%), respectively. Phylogenetic studies showed the mite proteins were monophyletic and shared a common ancestor with both actinomycetes and ascomycetes. The gene encoding the D. pteronyssinus protein was polymorphic and intronless in contrast to that reported for D. farinae. Homology studies suggest that the mite, ascomycete and actinomycete proteins are involved in the catalysis of stem peptide attached to peptidoglycan. The finding of a gene encoding a P60 family member in the D. pteronyssinus genome together with the presence of a bacterial promotor suggests an evolutionary link to one or more prokaryotic endosymbionts.}, }
@article {pmid26559510, year = {2015}, author = {Luck, AN and Anderson, KG and McClung, CM and VerBerkmoes, NC and Foster, JM and Michalski, ML and Slatko, BE}, title = {Tissue-specific transcriptomics and proteomics of a filarial nematode and its Wolbachia endosymbiont.}, journal = {BMC genomics}, volume = {16}, number = {}, pages = {920}, pmid = {26559510}, issn = {1471-2164}, mesh = {Animals ; Cluster Analysis ; Computational Biology/methods ; Dirofilaria immitis/*genetics/*metabolism ; Female ; Gene Expression Profiling ; Male ; Organ Specificity/genetics ; *Proteome ; Proteomics ; *Symbiosis ; *Transcriptome ; Wolbachia/*genetics/*metabolism ; }, abstract = {BACKGROUND: Filarial nematodes cause debilitating human diseases. While treatable, recent evidence suggests drug resistance is developing, necessitating the development of novel targets and new treatment options. Although transcriptomic and proteomic studies around the nematode life cycle have greatly enhanced our knowledge, whole organism approaches have not provided spatial resolution of gene expression, which can be gained by examining individual tissues. Generally, due to their small size, tissue dissection of human-infecting filarial nematodes remains extremely challenging. However, canine heartworm disease is caused by a closely related and much larger filarial nematode, Dirofilaria immitis. As with many other filarial nematodes, D. immitis contains Wolbachia, an obligate bacterial endosymbiont present in the hypodermis and developing oocytes within the uterus. Here, we describe the first concurrent tissue-specific transcriptomic and proteomic profiling of a filarial nematode (D. immitis) and its Wolbachia (wDi) in order to better understand tissue functions and identify tissue-specific antigens that may be used for the development of new diagnostic and therapeutic tools.<br><br>METHODS: Adult D. immitis worms were dissected into female body wall (FBW), female uterus (FU), female intestine (FI), female head (FH), male body wall (MBW), male testis (MT), male intestine (MI), male head (MH) and 10.1186/s12864-015-2083-2 male spicule (MS) and used to prepare transcriptomic and proteomic libraries.<br><br>RESULTS: Transcriptomic and proteomic analysis of several D. immitis tissues identified many biological functions enriched within certain tissues. Hierarchical clustering of the D. immitis tissue transcriptomes, along with the recently published whole-worm adult male and female D. immitis transcriptomes, revealed that the whole-worm transcriptome is typically dominated by transcripts originating from reproductive tissue. The uterus appeared to have the most variable transcriptome, possibly due to age. Although many functions are shared between the reproductive tissues, the most significant differences in gene expression were observed between the uterus and testis. Interestingly, wDi gene expression in the male and female body wall is fairly similar, yet slightly different to that of Wolbachia gene expression in the uterus. Proteomic methods verified 32 % of the predicted D. immitis proteome, including over 700 hypothetical proteins of D. immitis. Of note, hypothetical proteins were among some of the most abundant Wolbachia proteins identified, which may fulfill some important yet still uncharacterized biological function.<br><br>CONCLUSIONS: The spatial resolution gained from this parallel transcriptomic and proteomic analysis adds to our understanding of filarial biology and serves as a resource with which to develop future therapeutic strategies against filarial nematodes and their Wolbachia endosymbionts.}, }
@article {pmid26556361, year = {2015}, author = {Johnson, KN}, title = {The Impact of Wolbachia on Virus Infection in Mosquitoes.}, journal = {Viruses}, volume = {7}, number = {11}, pages = {5705-5717}, pmid = {26556361}, issn = {1999-4915}, mesh = {Animals ; Culicidae/*microbiology/*virology ; Insect Vectors/*microbiology/*virology ; *Symbiosis ; Viruses/*growth &amp; development ; Wolbachia/growth &amp; development/*physiology ; }, abstract = {Mosquito-borne viruses such as dengue, West Nile and chikungunya viruses cause significant morbidity and mortality in human populations. Since current methods are not sufficient to control disease occurrence, novel methods to control transmission of arboviruses would be beneficial. Recent studies have shown that virus infection and transmission in insects can be impeded by co-infection with the bacterium Wolbachia pipientis. Wolbachia is a maternally inherited endosymbiont that is commonly found in insects, including a number of mosquito vector species. In Drosophila, Wolbachia mediates antiviral protection against a broad range of RNA viruses. This discovery pointed to a potential strategy to interfere with mosquito transmission of arboviruses by artificially infecting mosquitoes with Wolbachia. This review outlines research on the prevalence of Wolbachia in mosquito vector species and the impact of antiviral effects in both naturally and artificially Wolbachia-infected mosquitoes.}, }
@article {pmid26556278, year = {2015}, author = {Moriyama, M and Nikoh, N and Hosokawa, T and Fukatsu, T}, title = {Riboflavin Provisioning Underlies Wolbachia's Fitness Contribution to Its Insect Host.}, journal = {mBio}, volume = {6}, number = {6}, pages = {e01732-15}, pmid = {26556278}, issn = {2150-7511}, mesh = {Animals ; Biosynthetic Pathways/genetics ; Evolution, Molecular ; Insecta/*microbiology/*physiology ; Riboflavin/*metabolism ; *Symbiosis ; Wolbachia/genetics/*metabolism/*physiology ; }, abstract = {UNLABELLED: Endosymbiotic bacteria of the genus Wolbachia represent the most successful symbiotic bacteria in the terrestrial ecosystem. The success of Wolbachia has been ascribed to its remarkable phenotypic effects on host reproduction, such as cytoplasmic incompatibility, whereby maternally inherited bacteria can spread in their host populations at the expense of their host's fitness. Meanwhile, recent theoretical as well as empirical studies have unveiled that weak and/or conditional positive fitness effects may significantly facilitate invasion and spread of Wolbachia infections in host populations. Here, we report a previously unrecognized nutritional aspect, the provision of riboflavin (vitamin B2), that potentially underpins the Wolbachia-mediated fitness benefit to insect hosts. A comparative genomic survey for synthetic capability of B vitamins revealed that only the synthesis pathway for riboflavin is highly conserved among diverse insect-associated Wolbachia strains, while the synthesis pathways for other B vitamins were either incomplete or absent. Molecular phylogenetic and genomic analyses of riboflavin synthesis genes from diverse Wolbachia strains revealed that, in general, their phylogenetic relationships are concordant with Wolbachia's genomic phylogeny, suggesting that the riboflavin synthesis genes have been stably maintained in the course of Wolbachia evolution. In rearing experiments with bedbugs (Cimex lectularius) on blood meals in which B vitamin contents were manipulated, we demonstrated that Wolbachia's riboflavin provisioning significantly contributes to growth, survival, and reproduction of the insect host. These results provide a physiological basis upon which Wolbachia-mediated positive fitness consequences are manifested and shed new light on the ecological and evolutionary relevance of Wolbachia infections.<br><br>IMPORTANCE: Conventionally, Wolbachia has been regarded as a parasitic bacterial endosymbiont that manipulates the host insect's reproduction in a selfish manner, which tends to affect a host's fitness negatively. Meanwhile, some theories predict that, at the same time, Wolbachia can directly affect the host's fitness positively, which may potentially reconcile the negative effect and facilitate spread and stability of the symbiotic association. Here we demonstrate, by using comparative genomic and experimental approaches, that among synthetic pathways for B vitamins, the synthetic pathway for riboflavin (vitamin B2) is exceptionally conserved among diverse insect-associated Wolbachia strains, and Wolbachia's riboflavin provisioning certainly contributes to growth, survival, and reproduction in an insect. These findings uncover a nutritional mechanism of a Wolbachia-mediated fitness benefit, which provides empirical evidence highlighting a "Jekyll and Hyde" aspect of Wolbachia infection.}, }
@article {pmid26548557, year = {2016}, author = {Arbuthnott, D and Levin, TC and Promislow, DE}, title = {The impacts of Wolbachia and the microbiome on mate choice in Drosophila melanogaster.}, journal = {Journal of evolutionary biology}, volume = {29}, number = {2}, pages = {461-468}, pmid = {26548557}, issn = {1420-9101}, support = {R01 GM102279/GM/NIGMS NIH HHS/United States ; GM102279/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila melanogaster/*microbiology/*physiology ; Female ; Male ; Mating Preference, Animal/*physiology ; Microbiota/*physiology ; Species Specificity ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Symbionts and parasites can manipulate their hosts' reproduction to their own benefit, profoundly influencing patterns of mate choice and evolution of the host population. Wolbachia is one of the most widespread symbionts among arthropods, and one that alters its hosts' reproduction in diverse and dramatic ways. While we are beginning to appreciate how Wolbachia's extreme manipulations of host reproduction can influence species diversification and reproductive isolation, we understand little about how symbionts and Wolbachia, in particular, may affect intrapopulation processes of mate choice. We hypothesized that the maternally transmitted Wolbachia would increase the attractiveness of its female hosts to further its own spread. We therefore tested the effects of Wolbachia removal and microbiome disruption on female attractiveness and male mate choice among ten isofemale lines of Drosophila melanogaster. We found variable effects of general microbiome disruption on female attractiveness, with indications that bacteria interact with hosts in a line-specific manner to affect female attractiveness. However, we found no evidence that Wolbachia influence female attractiveness or male mate choice among these lines. Although the endosymbiont Wolbachia can greatly alter the reproduction of their hosts in many species, there is no indication that they alter mate choice behaviours in D. melanogaster.}, }
@article {pmid26543129, year = {2015}, author = {Suzuki, H and Dapper, AL and Jackson, CE and Lee, H and Pejaver, V and Doak, TG and Lynch, M and Preer, JR}, title = {Draft Genome Sequence of Caedibacter varicaedens, a Kappa Killer Endosymbiont Bacterium of the Ciliate Paramecium biaurelia.}, journal = {Genome announcements}, volume = {3}, number = {6}, pages = {}, pmid = {26543129}, issn = {2169-8287}, abstract = {Caedibacter varicaedens is a kappa killer endosymbiont bacterium of the ciliate Paramecium biaurelia. Here, we present the draft genome sequence of C. varicaedens.}, }
@article {pmid26542076, year = {2015}, author = {Lawrence, AL and Hii, SF and Chong, R and Webb, CE and Traub, R and Brown, G and Šlapeta, J}, title = {Evaluation of the bacterial microbiome of two flea species using different DNA-isolation techniques provides insights into flea host ecology.}, journal = {FEMS microbiology ecology}, volume = {91}, number = {12}, pages = {}, doi = {10.1093/femsec/fiv134}, pmid = {26542076}, issn = {1574-6941}, mesh = {Animals ; Australia ; Bacteroidetes/genetics/*isolation &amp; purification ; Base Sequence ; Cats ; Cyclooxygenase 1/genetics ; DNA, Bacterial/genetics/*isolation &amp; purification ; High-Throughput Nucleotide Sequencing ; *Host-Pathogen Interactions ; Microbiota/*genetics ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/*isolation &amp; purification ; Sequence Analysis, DNA ; Siphonaptera/*microbiology ; Tachyglossidae/microbiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Fleas (Siphonaptera) are ubiquitous blood-sucking pests of animals worldwide and are vectors of zoonotic bacteria such as Rickettsia and Bartonella. We performed Ion Torrent PGM amplicon sequencing for the bacterial 16S rRNA gene to compare the microbiome of the ubiquitous cat flea (Ctenocephalides f. felis) and the host-specific echidna stickfast flea (Echidnophaga a. ambulans) and evaluated potential bias produced during common genomic DNA-isolation methods. We demonstrated significant differences in the bacterial community diversity between the two flea species but not between protocols combining surface sterilisation with whole flea homogenisation or exoskeleton retention. Both flea species were dominated by obligate intracellular endosymbiont Wolbachia, and the echidna stickfast fleas possessed the endosymbiont Cardinium. Cat fleas that were not surface sterilised showed presence of Candidatus 'Rickettsia senegalensis' DNA, the first report of its presence in Australia. In the case of Rickettsia, we show that sequencing depth of 50 000 was required for comparable sensitivity with Rickettsia qPCR. Low-abundance bacterial genera are suggested to reflect host ecology. The deep-sequencing approach demonstrates feasibility of pathogen detection with simultaneous quantitative analysis and evaluation of the inter-relationship of microbes within vectors.}, }
@article {pmid26539175, year = {2015}, author = {Poole, AM and Lundin, D and Rytkönen, KT}, title = {The evolution of early cellular systems viewed through the lens of biological interactions.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {1144}, pmid = {26539175}, issn = {1664-302X}, abstract = {The minimal cell concept represents a pragmatic approach to the question of how few genes are required to run a cell. This is a helpful way to build a parts-list, and has been more successful than attempts to deduce a minimal gene set for life by inferring the gene repertoire of the last universal common ancestor, as few genes trace back to this hypothetical ancestral state. However, the study of minimal cellular systems is the study of biological outliers where, by practical necessity, coevolutionary interactions are minimized or ignored. In this paper, we consider the biological context from which minimal genomes have been removed. For instance, some of the most reduced genomes are from endosymbionts and are the result of coevolutionary interactions with a host; few such organisms are "free-living." As few, if any, biological systems exist in complete isolation, we expect that, as with modern life, early biological systems were part of an ecosystem, replete with organismal interactions. We favor refocusing discussions of the evolution of cellular systems on processes rather than gene counts. We therefore draw a distinction between a pragmatic minimal cell (an interesting engineering problem), a distributed genome (a system resulting from an evolutionary transition involving more than one cell) and the looser coevolutionary interactions that are ubiquitous in ecosystems. Finally, we consider the distributed genome and coevolutionary interactions between genomic entities in the context of early evolution.}, }
@article {pmid26531251, year = {2016}, author = {Yeap, HL and Rašić, G and Endersby-Harshman, NM and Lee, SF and Arguni, E and Le Nguyen, H and Hoffmann, AA}, title = {Mitochondrial DNA variants help monitor the dynamics of Wolbachia invasion into host populations.}, journal = {Heredity}, volume = {116}, number = {3}, pages = {265-276}, pmid = {26531251}, issn = {1365-2540}, mesh = {Aedes/*genetics/*microbiology ; Animals ; Australia ; DNA, Mitochondrial/*genetics ; Genetic Markers ; *Genetic Variation ; Genetics, Population ; Haplotypes ; Insect Vectors/genetics/microbiology ; Models, Biological ; Models, Genetic ; *Pest Control, Biological ; *Wolbachia ; }, abstract = {Wolbachia is the most widespread endosymbiotic bacterium of insects and other arthropods that can rapidly invade host populations. Deliberate releases of Wolbachia into natural populations of the dengue fever mosquito, Aedes aegypti, are used as a novel biocontrol strategy for dengue suppression. Invasion of Wolbachia through the host population relies on factors such as high fidelity of the endosymbiont transmission and limited immigration of uninfected individuals, but these factors can be difficult to measure. One way of acquiring relevant information is to consider mitochondrial DNA (mtDNA) variation alongside Wolbachia in field-caught mosquitoes. Here we used diagnostic mtDNA markers to differentiate infection-associated mtDNA haplotypes from those of the uninfected mosquitoes at release sites. Unique haplotypes associated with Wolbachia were found at locations outside Australia. We also performed mathematical and qualitative analyses including modelling the expected dynamics of the Wolbachia and mtDNA variants during and after a release. Our analyses identified key features in haplotype frequency patterns to infer the presence of imperfect maternal transmission of Wolbachia, presence of immigration and possibly incomplete cytoplasmic incompatibility. We demonstrate that ongoing screening of the mtDNA variants should provide information on maternal leakage and immigration, particularly in releases outside Australia. As we demonstrate in a case study, our models to track the Wolbachia dynamics can be successfully applied to temporal studies in natural populations or Wolbachia release programs, as long as there is co-occurring mtDNA variation that differentiates infected and uninfected populations.}, }
@article {pmid26520831, year = {2016}, author = {Donald, KJ and Clarke, HV and Mitchell, C and Cornwell, RM and Hubbard, SF and Karley, AJ}, title = {Protection of Pea Aphids Associated with Coinfecting Bacterial Symbionts Persists During Superparasitism by a Braconid Wasp.}, journal = {Microbial ecology}, volume = {71}, number = {1}, pages = {1-4}, pmid = {26520831}, issn = {1432-184X}, mesh = {Animals ; Aphids/growth &amp; development/*microbiology/*parasitology/physiology ; Enterobacteriaceae/*physiology ; Female ; Larva/growth &amp; development ; Male ; Nymph/drug effects ; *Symbiosis ; Wasps/*physiology ; }, abstract = {Bacterial endosymbionts that associate facultatively with insect herbivores can influence insect fitness and trophic interactions. The pea aphid, Acyrthosiphon pisum, can be protected from parasitism by the braconid wasp Aphidius ervi when harbouring particular symbiotic bacteria, with specific endosymbiont coinfections providing almost complete protection. However, studies often quantify aphid mummification with no control over parasitoid oviposition per aphid; thus, if mummy production fails or is low, the causes are often unclear. Here, we show that the high level of protection associated with the coinfecting endosymbionts Hamiltonella defensa and X-type is maintained even when pea aphids are superparasitised. This contrasts strongly with the protection provided by H. defensa alone, which has been shown by others to be overcome by superparasitism. By dissecting aphids exposed to two parasitoid attacks, we reveal that A. ervi deposits eggs equally freely in endosymbiont-infected and uninfected nymphs, and lack of mummification in endosymbiont-protected nymphs arises from failure of the wasp eggs to hatch or emerging larvae to develop.}, }
@article {pmid26520052, year = {2016}, author = {Lopes de Carvalho, I and Toledo, A and Carvalho, CL and Barandika, JF and Respicio-Kingry, LB and Garcia-Amil, C and García-Pérez, AL and Olmeda, AS and Zé-Zé, L and Petersen, JM and Anda, P and Núncio, MS and Escudero, R}, title = {Francisella species in ticks and animals, Iberian Peninsula.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {1}, pages = {159-165}, doi = {10.1016/j.ttbdis.2015.10.009}, pmid = {26520052}, issn = {1877-9603}, mesh = {Animals ; Animals, Wild ; DNA, Bacterial/genetics ; Francisella/genetics/*isolation &amp; purification ; Gram-Negative Bacterial Infections/epidemiology/microbiology/*veterinary ; Livestock ; Phylogeny ; Polymorphism, Genetic ; Portugal/epidemiology ; Spain/epidemiology ; Ticks/*microbiology ; }, abstract = {The presence of Francisella species in 2134 ticks, 93 lagomorphs and 280 small mammals from the Iberian Peninsula was studied. Overall, 19 ticks and 6 lagomorphs were positive for Francisella tularensis subsp. holarctica, suggesting, as described for other regions, that lagomorphs may have an important role in the maintenance of F. tularensis in nature. Of the 6 positive lagomorphs, 4 were identified as the European rabbit, Oryctogalus cuniculus. Additionally, 353 ticks and 3 small mammals were PCR positive for Francisella-like endosymbionts (FLEs) and one small mammal was also positive for Francisella hispaniensis-like DNA sequences. Among FLE positive specimens, a variety of sequence types were detected: ticks were associated with 5 lpnA sequence types, with only one type identified per tick, in contrast to 2 lpnA sequence types detected in a single wood mouse (Apodemus sylvaticus). To our knowledge, this is the first report of FLEs in free-living small mammals as well as the first detection of F. hispaniensis-like sequences in a natural setting.}, }
@article {pmid26518739, year = {2016}, author = {Lam, DW and Verbruggen, H and Saunders, GW and Vis, ML}, title = {Multigene phylogeny of the red algal subclass Nemaliophycidae.}, journal = {Molecular phylogenetics and evolution}, volume = {94}, number = {Pt B}, pages = {730-736}, doi = {10.1016/j.ympev.2015.10.015}, pmid = {26518739}, issn = {1095-9513}, mesh = {Bayes Theorem ; *Genes, Plant ; Genetic Markers ; Mitochondria/genetics ; Molecular Typing ; Phylogeny ; Plastids/genetics ; Rhodophyta/*classification ; }, abstract = {The red algae (Rhodophyta) are a lineage of primary endosymbionts whose ancestors represent some of the first photosynthetic eukaryotes on the planet. They primarily inhabit marine ecosystems, with only ∼5% of species found in freshwater systems. The subclass Nemaliophycidae is very diverse in ecological and life history features and therefore a useful model to study these traits, but the phylogenetic relationships among the orders are, for the most part, poorly resolved. To elucidate the phylogeny of the Nemaliophycidae, we constructed a nine-gene dataset comprised of nuclear, plastid, and mitochondrial markers for 67 red algal specimens. The resulting maximum likelihood (ML) phylogeny confirmed the monophyly of all orders. The sister relationship of the Acrochaetiales and Palmariales received high support and the relationship of the Balliales with Balbianiales and Entwisleiales with Colaconematales was moderately supported. The Nemaliales, Entwisleiales, Colaconematales, Palmariales and Acrochaetiales formed a highly supported clade. Unfortunately, all other relationships among the orders had low bootstrap support. Although the ML analysis did not resolve many of the relationships, further analyses suggested that a resolution is possible. A Phycas analysis supported a dichotomously branching tree and Bayesian analysis showed a similar topology with all relationships highly supported. Simulations extrapolating the number of nucleotide characters beyond the current size of the dataset suggested that most nodes in the phylogeny would be resolved if more data become available. Phylogenomic approaches will be necessary to provide a well-supported phylogeny of this subclass with all relationships resolved such that the evolution of freshwater species from marine ancestors as well as reproductive traits can be explored.}, }
@article {pmid26517699, year = {2016}, author = {Ohbayashi, R and Watanabe, S and Ehira, S and Kanesaki, Y and Chibazakura, T and Yoshikawa, H}, title = {Diversification of DnaA dependency for DNA replication in cyanobacterial evolution.}, journal = {The ISME journal}, volume = {10}, number = {5}, pages = {1113-1121}, pmid = {26517699}, issn = {1751-7370}, mesh = {Bacterial Proteins/*metabolism ; *Biological Evolution ; Cyanobacteria/classification/*genetics/*metabolism ; *DNA Replication ; DNA-Binding Proteins/*metabolism ; Fresh Water/*microbiology ; Synechococcus/genetics/metabolism ; Synechocystis/genetics/metabolism ; }, abstract = {Regulating DNA replication is essential for all living cells. The DNA replication initiation factor DnaA is highly conserved in prokaryotes and is required for accurate initiation of chromosomal replication at oriC. DnaA-independent free-living bacteria have not been identified. The dnaA gene is absent in plastids and some symbiotic bacteria, although it is not known when or how DnaA-independent mechanisms were acquired. Here, we show that the degree of dependency of DNA replication on DnaA varies among cyanobacterial species. Deletion of the dnaA gene in Synechococcus elongatus PCC 7942 shifted DNA replication from oriC to a different site as a result of the integration of an episomal plasmid. Moreover, viability during the stationary phase was higher in dnaA disruptants than in wild-type cells. Deletion of dnaA did not affect DNA replication or cell growth in Synechocystis sp. PCC 6803 or Anabaena sp. PCC 7120, indicating that functional dependency on DnaA was already lost in some nonsymbiotic cyanobacterial lineages during diversification. Therefore, we proposed that cyanobacteria acquired DnaA-independent replication mechanisms before symbiosis and such an ancestral cyanobacterium was the sole primary endosymbiont to form a plastid precursor.}, }
@article {pmid26516375, year = {2015}, author = {Cassone, BJ and Wenger, JA and Michel, AP}, title = {Whole Genome Sequence of the Soybean Aphid Endosymbiont Buchnera aphidicola and Genetic Differentiation among Biotype-Specific Strains.}, journal = {Journal of genomics}, volume = {3}, number = {}, pages = {85-94}, pmid = {26516375}, issn = {1839-9940}, abstract = {Endosymbiosis with microorganisms is common in insects, with more than 10% of species requiring the metabolic capabilities of intracellular bacteria for their nutrient acquisition. Aphids harbor an obligate mutualism with the vertically transferred endosymbiont, Buchnera aphidicola, which produces key nutrients lacking in the aphid's phloem-based diet that are necessary for normal development and reproduction. It is thought that, in some groups of insects, bacterial symbionts may play key roles in biotype evolution against host-plant resistance. The genome of Buchnera has been sequenced in several aphid strains but little genomic data is currently available for the soybean aphid (Aphis glycines), one of the most important pests of soybean in North America. In this study, DNA sequencing was used to assemble and annotate the genome sequence of the Buchnera A. glycines strain and to reconstruct phylogenetic relationships among different strains. In addition, we identified several fixed Buchnera SNPs between Aphis glycines biotypes that were avirulent or virulent to a soybean aphid resistance gene (Rag1). The results of this study describe the genetic and evolutionary relationships of the Buchnera A. glycines strain, and begin to define the roles of an aphid symbiont in host-plant resistance.}, }
@article {pmid26515059, year = {2016}, author = {Al-Deeb, MA and Frangoulidis, D and Walter, MC and Kömpf, D and Fischer, SF and Petney, T and Muzaffar, SB}, title = {Coxiella-like endosymbiont in argasid ticks (Ornithodoros muesebecki) from a Socotra Cormorant colony in Umm Al Quwain, United Arab Emirates.}, journal = {Ticks and tick-borne diseases}, volume = {7}, number = {1}, pages = {166-171}, doi = {10.1016/j.ttbdis.2015.10.012}, pmid = {26515059}, issn = {1877-9603}, mesh = {Animals ; Bird Diseases/*parasitology ; Birds ; Coxiella/*physiology ; DNA, Bacterial/genetics ; Host-Pathogen Interactions ; Islands ; Ornithodoros/*microbiology ; Polymerase Chain Reaction ; United Arab Emirates ; }, abstract = {Coxiella burnetii is a pathogen causing Q fever in domestic animals and humans. Seabirds have been implicated as possible reservoirs of this bacterium in the Arabian Gulf and in the Western Indian Ocean. Recently, Coxiella species closely related to C. burnetii was detected from ticks collected from oil rigs used as roosting areas by Socotra Cormorants (Phalacrocorax nigrogularis) in the western Arabian Gulf. We collected ticks from the largest breeding colony of Socotra Cormorants in the United Arab Emirates on the eastern extreme of the species' breeding range to determine the prevalence of C. burnetii and evaluate its role as a wild reservoir. All ticks were identified as Ornithodoros muesebecki and genomic DNA was extracted from larval and nymph/adult tick pools. Multiplex PCR tests were performed targeting three C. burnetii specific genes. C. burnetii was not detected although a Coxiella-like endosymbiont was identified that was closely related to Coxiella symbionts from Ornithodoros capensis ticks. Because domestic and wild ungulates are the primary source of C. burnetii, we suggest that the presence of free-ranging, native and non-native ungulates in some off-shore islands in the Arabian Gulf could disseminate C. burnetii to seabirds. More comprehensive studies on seabird colonies are needed to better understand the diversity and prevalence of Coxiella symbionts and to establish if C. burnetii is endemic on some of these islands.}, }
@article {pmid26499484, year = {2015}, author = {Agamennone, V and Jakupović, D and Weedon, JT and Suring, WJ and van Straalen, NM and Roelofs, D and Röling, WF}, title = {The microbiome of Folsomia candida: an assessment of bacterial diversity in a Wolbachia-containing animal.}, journal = {FEMS microbiology ecology}, volume = {91}, number = {11}, pages = {}, doi = {10.1093/femsec/fiv128}, pmid = {26499484}, issn = {1574-6941}, mesh = {Animals ; Arthropods/*microbiology/physiology ; Bacteria/*classification/genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; DNA, Bacterial/genetics ; Denaturing Gradient Gel Electrophoresis ; Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA/methods ; *Soil ; Soil Microbiology ; Symbiosis ; Wolbachia/physiology ; }, abstract = {The springtail Folsomia candida is an important model organism for soil ecology, ecotoxicology and ecogenomics. The decomposer activities of soil invertebrates like Folsomia depend on their relationship with microbial communities including gut symbionts. In this paper, we apply high-throughput sequencing to provide a detailed characterization of the bacterial community associated with parthenogenetic F. candida. First, we evaluated a method to suppress the amplification of DNA from the endosymbiont Wolbachia, to prevent it from interfering with the identification of less abundant operational taxonomic units (OTUs). The suppression treatment applied was effective against Wolbachia and did not interfere with the detection of the most abundant OTUs (59 OTUs, contributing over 87% of the reads). However, this method did affect the inferred community composition. Significant differences were subsequently observed in the composition of bacterial communities associated with two different strains of F. candida. A total of 832 OTUs were found, of which 45% were only present in one strain and 17% only in the other. Among the 20 most abundant OTUs, 16 were shared between strains. Denaturing gradient gel electrophoresis and clone libraries, although unable to capture the full diversity of the bacterial community, provided results that supported the NGS data.}, }
@article {pmid26497146, year = {2015}, author = {Gutzwiller, F and Carmo, CR and Miller, DE and Rice, DW and Newton, IL and Hawley, RS and Teixeira, L and Bergman, CM}, title = {Dynamics of Wolbachia pipientis Gene Expression Across the Drosophila melanogaster Life Cycle.}, journal = {G3 (Bethesda, Md.)}, volume = {5}, number = {12}, pages = {2843-2856}, pmid = {26497146}, issn = {2160-1836}, support = {BB/L002817/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Cluster Analysis ; Computational Biology ; Drosophila melanogaster/*growth &amp; development/microbiology ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; Genome, Bacterial ; High-Throughput Nucleotide Sequencing ; Host-Pathogen Interactions/genetics ; Life Cycle Stages ; Phylogeny ; Stress, Physiological/genetics ; Symbiosis ; Transcriptome ; Wolbachia/*genetics ; }, abstract = {Symbiotic interactions between microbes and their multicellular hosts have manifold biological consequences. To better understand how bacteria maintain symbiotic associations with animal hosts, we analyzed genome-wide gene expression for the endosymbiotic α-proteobacteria Wolbachia pipientis across the entire life cycle of Drosophila melanogaster. We found that the majority of Wolbachia genes are expressed stably across the D. melanogaster life cycle, but that 7.8% of Wolbachia genes exhibit robust stage- or sex-specific expression differences when studied in the whole-organism context. Differentially-expressed Wolbachia genes are typically up-regulated after Drosophila embryogenesis and include many bacterial membrane, secretion system, and ankyrin repeat-containing proteins. Sex-biased genes are often organized as small operons of uncharacterized genes and are mainly up-regulated in adult Drosophila males in an age-dependent manner. We also systematically investigated expression levels of previously-reported candidate genes thought to be involved in host-microbe interaction, including those in the WO-A and WO-B prophages and in the Octomom region, which has been implicated in regulating bacterial titer and pathogenicity. Our work provides comprehensive insight into the developmental dynamics of gene expression for a widespread endosymbiont in its natural host context, and shows that public gene expression data harbor rich resources to probe the functional basis of the Wolbachia-Drosophila symbiosis and annotate the transcriptional outputs of the Wolbachia genome.}, }
@article {pmid26494681, year = {2015}, author = {Soobramoney, LA and Featherston, J and Gray, VM}, title = {Draft Whole-Genome Sequence of Xenorhabdus sp. Strain GDc328, Isolated from the Indigenous South African Nematode Host Steinernema khoisanae.}, journal = {Genome announcements}, volume = {3}, number = {5}, pages = {}, pmid = {26494681}, issn = {2169-8287}, abstract = {Here, we describe the draft genome sequence of Xenorhabdus sp. GDc328, an endosymbiont of the native South African entomopathogenic nematode host, Steinernema khoisanae. The total genome size of the bacteria is 4.09 Mb. The genome comprises a total of 3,608 genes with a molecular G+C content of 44.64%.}, }
@article {pmid26492411, year = {2015}, author = {Furihata, S and Hirata, M and Matsumoto, H and Hayakawa, Y}, title = {Bacteria Endosymbiont, Wolbachia, Promotes Parasitism of Parasitoid Wasp Asobara japonica.}, journal = {PloS one}, volume = {10}, number = {10}, pages = {e0140914}, pmid = {26492411}, issn = {1932-6203}, mesh = {Animals ; Drosophila melanogaster/parasitology ; Female ; Host-Pathogen Interactions/physiology ; Male ; Oviposition/physiology ; Symbiosis/physiology ; Wasps/*microbiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia is the most widespread endosymbiotic bacterium that manipulates reproduction of its arthropod hosts to enhance its own spread throughout host populations. Infection with Wolbachia causes complete parthenogenetic reproduction in many Hymenoptera, producing only female offspring. The mechanism of such reproductive manipulation by Wolbachia has been extensively studied. However, the effects of Wolbachia symbiosis on behavioral traits of the hosts are scarcely investigated. The parasitoid wasp Asobara japonica is an ideal insect to investigate this because symbiotic and aposymbiotic strains are available: Wolbachia-infected Tokyo (TK) and noninfected Iriomote (IR) strains originally collected on the main island and southwest islands of Japan, respectively. We compared the oviposition behaviors of the two strains and found that TK strain females parasitized Drosophila melanogaster larvae more actively than the IR strain, especially during the first two days after eclosion. Removing Wolbachia from the TK strain wasps by treatment with tetracycline or rifampicin decreased their parasitism activity to the level of the IR strain. Morphological and behavioral analyses of both strain wasps showed that Wolbachia endosymbionts do not affect development of the host female reproductive tract and eggs, but do enhance host-searching ability of female wasps. These results suggest the possibility that Wolbachia endosymbionts may promote their diffusion and persistence in the host A. japonica population not only at least partly by parthenogenesis but also by enhancement of oviposition frequency of the host females.}, }
@article {pmid26482132, year = {2015}, author = {Masson, F and Moné, Y and Vigneron, A and Vallier, A and Parisot, N and Vincent-Monégat, C and Balmand, S and Carpentier, MC and Zaidman-Rémy, A and Heddi, A}, title = {Weevil endosymbiont dynamics is associated with a clamping of immunity.}, journal = {BMC genomics}, volume = {16}, number = {}, pages = {819}, pmid = {26482132}, issn = {1471-2164}, mesh = {Animals ; Apoptosis/genetics ; Autophagy/genetics ; Bacteria/genetics ; Base Sequence ; Digestive System/microbiology ; High-Throughput Nucleotide Sequencing ; Insect Proteins/biosynthesis/*genetics ; Larva/growth &amp; development/immunology/microbiology ; Symbiosis/*genetics ; Weevils/*genetics/growth &amp; development/*immunology/microbiology ; }, abstract = {BACKGROUND: Insects subsisting on nutritionally unbalanced diets have evolved long-term mutualistic relationships with intracellular symbiotic bacteria (endosymbionts). The endosymbiont population load undergoes changes along with insect development. In the cereal weevil Sitophilus oryzae, the midgut endosymbionts Sodalis pierantonius drastically multiply following adult metamorphosis and rapidly decline until total elimination when the insect achieves its cuticle synthesis. Whilst symbiont load was shown to timely meet insect metabolic needs, little is known about the host molecular and immune processes underlying this dynamics.<br><br>METHODS: We performed RNA sequencing analysis on weevil midguts at three representative phases of the endosymbiont dynamics (i.e. increase, climax and decrease). To screen genes which transcriptional changes are specifically related to symbiont dynamics and not to the intrinsic development of the midgut, we further have monitored by RT-qPCR sixteen gene transcript levels in symbiotic and artificially non-symbiotic (aposymbiotic) weevils. We also localized the endosymbionts during the elimination process by fluorescence microscopy.<br><br>RESULTS: Functional analysis of the host differentially expressed genes by RNA sequencing showed that the main transcriptional changes occur during endosymbiont growth phase and affect cell proliferation, apoptosis, autophagy, phagocytosis, and metabolism of fatty acids and nucleic acids. We also showed that symbiont dynamics alters the expression of several genes involved in insect development. Our results strengthened the implication of apoptosis and autophagy processes in symbiont elimination and recycling. Remarkably, apart from the coleoptericin A that is known to target endosymbionts and controls their division and location, no gene coding antimicrobial peptide was upregulated during the symbiont growth and elimination phases.<br><br>CONCLUSION: We show that endosymbiont dynamics parallels numerous transcriptional changes in weevil developing adults and affects several biological processes, including metabolism and development. It also triggers cell apoptosis, autophagy and gut epithelial cell swelling and delamination. Strikingly, immunity is repressed during the whole process, presumably avoiding tissue inflammation and allowing insects to optimize nutrient recovery from recycled endosymbiont.}, }
@article {pmid26479912, year = {2016}, author = {Gillett, ND and Pan, Y and Eli Asarian, J and Kann, J}, title = {Spatial and temporal variability of river periphyton below a hypereutrophic lake and a series of dams.}, journal = {The Science of the total environment}, volume = {541}, number = {}, pages = {1382-1392}, doi = {10.1016/j.scitotenv.2015.10.048}, pmid = {26479912}, issn = {1879-1026}, mesh = {Biomass ; Diatoms ; *Environmental Monitoring ; *Eutrophication ; Lakes/*microbiology ; Plankton/classification/*growth &amp; development ; Rivers/*microbiology ; Spatio-Temporal Analysis ; }, abstract = {Klamath River is described as an "upside-down" river due to its origins from the hypereutrophic Upper Klamath Lake (UKL) and hydrology that is heavily regulated by upstream dams. Understanding the lake and reservoir effects on benthic communities in the river can inform important aspects of its water quality dynamics. Periphyton samples were collected in May-November from 2004, 2006-2013 at nine long-term monitoring sites along 306 river km below UKL and a series of dams (n=299). Cluster analysis of periphyton assemblages identified three statistically different periphyton groups (denoted Groups 1-3). Group 1 occurred primarily in the upstream reach for June-October and had a higher percentage of sestonic species, including the cyanobacteria Aphanizomenon flos-aquae and Microcystis aeruginosa, consistent with the presence of upstream reservoirs. Group 2 had the highest relative biomass of diatoms and lowest relative biomass of cyanobacteria. Sites in the lower reach of the Klamath River fell into Group 2 in May-June and transitioning into Group 3 for July-October. Group 3 was dominated by nitrogen (N)-fixing species, including three diatoms (Epithemia sorex, Epithemia turgida, and Rhopalodia gibba) with cyanobacterial endosymbionts and the cyanobacterium Calothrix sp. Periphyton assemblages were strongly associated with temporal variations in flow conditions (e.g., decreasing flow from spring to fall) and spatial gradients in nutrient concentrations (e.g., decreasing from upstream to downstream). The inverse longitudinal relationship between periphyton biomass and nutrients may be explained by the ability of benthic N-fixers (Group 3) to overcome N limitation. Overall results showed a strong inverse relationship between the relative biomass of N-fixers and nitrogen concentrations and flow. This long-term dataset provides valuable insight into Klamath River's seasonal and longitudinal patterns of benthic algal communities and associated environmental variables. Our findings can inform river management decisions such as reducing upstream nutrient loads, setting flow regimes, and potential dam removals.}, }
@article {pmid26478191, year = {2016}, author = {Revel, J and Massi, L and Mehiri, M and Boutoute, M and Mayzaud, P and Capron, L and Sabourault, C}, title = {Differential distribution of lipids in epidermis, gastrodermis and hosted Symbiodinium in the sea anemone Anemonia viridis.}, journal = {Comparative biochemistry and physiology. Part A, Molecular &amp; integrative physiology}, volume = {191}, number = {}, pages = {140-151}, doi = {10.1016/j.cbpa.2015.10.017}, pmid = {26478191}, issn = {1531-4332}, mesh = {Animals ; Cluster Analysis ; Dinoflagellida/*physiology ; Epidermis/*metabolism ; Fatty Acids/metabolism ; Heat-Shock Response ; *Lipid Metabolism ; Sea Anemones/*metabolism ; Stress, Physiological ; *Symbiosis ; }, abstract = {Cnidarian-dinoflagellate symbiosis mainly relies on nutrient recycling, thus providing both partners with a competitive advantage in nutrient-poor waters. Essential processes related to lipid metabolism can be influenced by various factors, including hyperthermal stress. This can affect the lipid content and distribution in both partners, while contributing to symbiosis disruption and bleaching. In order to gain further insight into the role and distribution of lipids in the cnidarian metabolism, we investigated the lipid composition of the sea anemone Anemonia viridis and its photosynthetic dinoflagellate endosymbionts (Symbiodinium). We compared the lipid content and fatty acid profiles of the host cellular layers, non-symbiotic epidermal and symbiont-containing gastrodermal cells, and those of Symbiodinium, in a mass spectrometry-based assessment. Lipids were more concentrated in Symbiodinium cells, and the lipid class distribution was dominated by polar lipids in all tissues. The fatty acid distribution between host cell layers and Symbiodinium cells suggested potential lipid transfers between the partners. The lipid composition and distribution was modified during short-term hyperthermal stress, mainly in Symbiodinium cells and gastrodermis. Exposure to elevated temperature rapidly caused a decrease in polar lipid C18 unsaturated fatty acids and a strong and rapid decrease in the abundance of polar lipid fatty acids relative to sterols. These lipid indicators could therefore be used as sensitive biomarkers to assess the physiology of symbiotic cnidarians, especially the effect of thermal stress at the onset of cnidarian bleaching. Overall, the findings of this study provide some insight on key lipids that may regulate maintenance of the symbiotic interaction.}, }
@article {pmid26471960, year = {2015}, author = {Delafont, V and Samba-Louaka, A and Bouchon, D and Moulin, L and Héchard, Y}, title = {Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free-living amoeba.}, journal = {Environmental microbiology reports}, volume = {7}, number = {6}, pages = {970-978}, doi = {10.1111/1758-2229.12343}, pmid = {26471960}, issn = {1758-2229}, mesh = {Amoeba/*microbiology ; *Bacteria/classification/genetics ; Metagenome ; Metagenomics ; Microbiota ; Phylogeny ; RNA, Ribosomal/genetics ; *Symbiosis ; }, abstract = {The TM6 phylum belongs to the so-called microbial dark matter that gathers uncultivated bacteria detected only via DNA sequencing. Recently, the genome sequence of a TM6 bacterium (TM6SC1) has led to suggest that this bacterium would adopt an endosymbiotic life. In the present paper, free-living amoebae bearing a TM6 strain were isolated from a water network. The amoebae were identified as Vermamoeba vermiformis and the presence of a TM6 strain was detected by polymerase chain reaction and microscopy. The partial sequence of its 16S rRNA gene showed this strain to be closely related to the sequenced TM6SC1 strain. These bacteria displayed a pyriform shape and were found within V. vermiformis. Therefore, these bacteria were named Vermiphilus pyriformis. Interactions studies showed that V. pyriformis was highly infectious and that its relation with V. vermiformis was specific and highly stable. Finally, it was found that V. pyriformis inhibited the encystment of V. vermiformis. Overall, this study describes for the first time an endosymbiotic relationship between a TM6 bacterium and a free-living amoeba in the environment. It suggests that other bacteria of the TM6 phylum might also be endosymbiotic bacteria and may be found in other free-living amoebae or other organisms.}, }
@article {pmid26470122, year = {2015}, author = {Ji, HL and Qi, LD and Hong, XY and Xie, HF and Li, YX}, title = {Effects of Host Sex, Plant Species, and Putative Host Species on the Prevalence of Wolbachia in Natural Populations of Bemisia tabaci (Hemiptera: Aleyrodidae): A Modified Nested PCR Study.}, journal = {Journal of economic entomology}, volume = {108}, number = {1}, pages = {210-218}, doi = {10.1093/jee/tou004}, pmid = {26470122}, issn = {0022-0493}, mesh = {Animals ; *Crops, Agricultural ; Female ; Hemiptera/*microbiology ; Male ; Polymerase Chain Reaction ; Wolbachia/*genetics ; }, abstract = {Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a globally distributed pest. One of the key endosymbionts in B. tabaci is Wolbachia, an α-proteobacterium implicated in many important biological processes. Previous studies indicated that the infection frequency of Wolbachia in Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) varied greatly among populations in different areas. However, little is known about the factors that influence the prevalence of Wolbachia in B. tabaci. In this paper, 25 field populations were collected from different locations in China, and 1,161 individuals were screened for the presence of Wolbachia using a nested polymerase chain reaction (PCR)-based method, which targets the wsp gene, to confirm Wolbachia infection status. The prevalence of Wolbachia ranged from 1.54 to 66.67% within the 25 field populations, and the infection frequency of Wolbachia was affected significantly by the putative species of B. tabaci. The infection frequency (51.55%) of Wolbachia was significantly greater in native species than in the MED (25.65%) and MEAM1 (14.37%). With the exception of host plant, all factors, including putative species, geographic location, and the sex of the host, affected the Wolbachia infection frequency in whiteflies. Six Wolbachia strains were found and clustered into four distinct clades upon phylogenetic analyses. Furthermore, Wolbachia in B. tabaci have close relationships with those from other host species, including Liriomyza trifolii (Burgess), Sogatella furcifera (Horvath), Nilaparvata lugens (Stål), and Culex pipiens L. The results demonstrated the variation and diversity of Wolbachia in B. tabaci field populations, and that the application of nested PCR extended our knowledge of Wolbachia infection in B. tabaci, especially in invasive whiteflies.}, }
@article {pmid26468067, year = {2015}, author = {Radzvilavicius, AL and Blackstone, NW}, title = {Conflict and cooperation in eukaryogenesis: implications for the timing of endosymbiosis and the evolution of sex.}, journal = {Journal of the Royal Society, Interface}, volume = {12}, number = {111}, pages = {20150584}, pmid = {26468067}, issn = {1742-5662}, mesh = {Adenylyl Cyclases/metabolism ; Alleles ; *Biological Evolution ; Calcium/metabolism ; Cytoplasm/metabolism ; Cytosol/metabolism ; Electron Transport ; Eukaryotic Cells/*physiology ; Genome ; Mitochondrial ADP, ATP Translocases/metabolism ; Models, Biological ; Oxidation-Reduction ; Phylogeny ; *Reproduction ; Signal Transduction ; *Symbiosis ; }, abstract = {Roughly 1.5-2.0 Gya, the eukaryotic cell evolved from an endosymbiosis of an archaeal host and proteobacterial symbionts. The timing of this endosymbiosis relative to the evolution of eukaryotic features remains subject to considerable debate, yet the evolutionary process itself constrains the timing of these events. Endosymbiosis entailed levels-of-selection conflicts, and mechanisms of conflict mediation had to evolve for eukaryogenesis to proceed. The initial mechanisms of conflict mediation (e.g. signalling with calcium and soluble adenylyl cyclase, substrate carriers, adenine nucleotide translocase, uncouplers) led to metabolic homeostasis in the eukaryotic cell. Later mechanisms (e.g. mitochondrial gene loss) contributed to the chimeric eukaryotic genome. These integral features of eukaryotes were derived because of, and therefore subsequent to, endosymbiosis. Perhaps the greatest opportunity for conflict arose with the emergence of eukaryotic sex, involving whole-cell fusion. A simple model demonstrates that competition on the lower level severely hinders the evolution of sex. Cytoplasmic mixing, however, is beneficial for non-cooperative endosymbionts, which could have used their aerobic metabolism to manipulate the life history of the host. While early evolution of sex may have facilitated symbiont acquisition, sex would have also destabilized the subsequent endosymbiosis. More plausibly, the evolution of sex and the true nucleus concluded the transition.}, }
@article {pmid26467026, year = {2016}, author = {Kaloshian, I and Walling, LL}, title = {Hemipteran and dipteran pests: Effectors and plant host immune regulators.}, journal = {Journal of integrative plant biology}, volume = {58}, number = {4}, pages = {350-361}, doi = {10.1111/jipb.12438}, pmid = {26467026}, issn = {1744-7909}, mesh = {Animals ; Diptera/*physiology ; Hemiptera/*physiology ; Host-Pathogen Interactions/*immunology ; Models, Biological ; Receptors, Cell Surface/metabolism ; Signal Transduction ; }, abstract = {Hemipteran and dipteran insects have behavioral, cellular and chemical strategies for evading or coping with the host plant defenses making these insects particularly destructive pests worldwide. A critical component of a host plant's defense to herbivory is innate immunity. Here we review the status of our understanding of the receptors that contribute to perception of hemipteran and dipteran pests and highlight the gaps in our knowledge in these early events in immune signaling. We also highlight recent advances in identification of the effectors that activate pattern-triggered immunity and those involved in effector-triggered immunity.}, }
@article {pmid26462790, year = {2015}, author = {Robson, JF and Barker, D}, title = {Comparison of the protein-coding gene content of Chlamydia trachomatis and Protochlamydia amoebophila using a Raspberry Pi computer.}, journal = {BMC research notes}, volume = {8}, number = {}, pages = {561}, pmid = {26462790}, issn = {1756-0500}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics/metabolism ; Chlamydia trachomatis/*genetics/metabolism ; Chlamydiales/*genetics/metabolism ; Computational Biology/*instrumentation ; Exodeoxyribonuclease V/genetics/metabolism ; Gene Expression ; Membrane Proteins/genetics/metabolism ; Microcomputers ; Molecular Sequence Annotation ; Molecular Sequence Data ; *Open Reading Frames ; Protein Interaction Mapping ; Sequence Alignment ; Sequence Homology, Amino Acid ; }, abstract = {BACKGROUND: To demonstrate the bioinformatics capabilities of a low-cost computer, the Raspberry Pi, we present a comparison of the protein-coding gene content of two species in phylum Chlamydiae: Chlamydia trachomatis, a common sexually transmitted infection of humans, and Candidatus Protochlamydia amoebophila, a recently discovered amoebal endosymbiont. Identifying species-specific proteins and differences in protein families could provide insights into the unique phenotypes of the two species.<br><br>RESULTS: Using a Raspberry Pi computer, sequence similarity-based protein families were predicted across the two species, C. trachomatis and P. amoebophila, and their members counted. Examples include nine multi-protein families unique to C. trachomatis, 132 multi-protein families unique to P. amoebophila and one family with multiple copies in both. Most families unique to C. trachomatis were polymorphic outer-membrane proteins. Additionally, multiple protein families lacking functional annotation were found. Predicted functional interactions suggest one of these families is involved with the exodeoxyribonuclease V complex.<br><br>CONCLUSION: The Raspberry Pi computer is adequate for a comparative genomics project of this scope. The protein families unique to P. amoebophila may provide a basis for investigating the host-endosymbiont interaction. However, additional species should be included; and further laboratory research is required to identify the functions of unknown or putative proteins. Multiple outer membrane proteins were found in C. trachomatis, suggesting importance for host evasion. The tyrosine transport protein family is shared between both species, with four proteins in C. trachomatis and two in P. amoebophila. Shared protein families could provide a starting point for discovery of wide-spectrum drugs against Chlamydiae.}, }
@article {pmid26458227, year = {2016}, author = {Jousselin, E and Clamens, AL and Galan, M and Bernard, M and Maman, S and Gschloessl, B and Duport, G and Meseguer, AS and Calevro, F and Coeur d'acier, A}, title = {Assessment of a 16S rRNA amplicon Illumina sequencing procedure for studying the microbiome of a symbiont-rich aphid genus.}, journal = {Molecular ecology resources}, volume = {16}, number = {3}, pages = {628-640}, doi = {10.1111/1755-0998.12478}, pmid = {26458227}, issn = {1755-0998}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*classification/genetics/*isolation &amp; purification ; Computational Biology/*methods ; High-Throughput Nucleotide Sequencing/*methods ; *Microbiota ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA/methods ; Symbiosis ; }, abstract = {The bacterial communities inhabiting arthropods are generally dominated by a few endosymbionts that play an important role in the ecology of their hosts. Rather than comparing bacterial species richness across samples, ecological studies on arthropod endosymbionts often seek to identify the main bacterial strains associated with each specimen studied. The filtering out of contaminants from the results and the accurate taxonomic assignment of sequences are therefore crucial in arthropod microbiome studies. We aimed here to validate an Illumina 16S rRNA gene sequencing protocol and analytical pipeline for investigating endosymbiotic bacteria associated with aphids. Using replicate DNA samples from 12 species (Aphididae: Lachninae, Cinara) and several controls, we removed individual sequences not meeting a minimum threshold number of reads in each sample and carried out taxonomic assignment for the remaining sequences. With this approach, we show that (i) contaminants accounted for a negligible proportion of the bacteria identified in our samples; (ii) the taxonomic composition of our samples and the relative abundance of reads assigned to a taxon were very similar across PCR and DNA replicates for each aphid sample; in particular, bacterial DNA concentration had no impact on the results. Furthermore, by analysing the distribution of unique sequences across samples rather than aggregating them into operational taxonomic units (OTUs), we gained insight into the specificity of endosymbionts for their hosts. Our results confirm that Serratia symbiotica is often present in Cinara species, in addition to the primary symbiont, Buchnera aphidicola. Furthermore, our findings reveal new symbiotic associations with Erwinia- and Sodalis-related bacteria. We conclude with suggestions for generating and analysing 16S rRNA gene sequences for arthropod-endosymbiont studies.}, }
@article {pmid26454017, year = {2015}, author = {Manzano-Marín, A and Oceguera-Figueroa, A and Latorre, A and Jiménez-García, LF and Moya, A}, title = {Solving a Bloody Mess: B-Vitamin Independent Metabolic Convergence among Gammaproteobacterial Obligate Endosymbionts from Blood-Feeding Arthropods and the Leech Haementeria officinalis.}, journal = {Genome biology and evolution}, volume = {7}, number = {10}, pages = {2871-2884}, pmid = {26454017}, issn = {1759-6653}, mesh = {Animals ; DNA, Bacterial/genetics ; Diptera/*microbiology ; Gammaproteobacteria/*genetics/*metabolism ; Genome, Bacterial ; Humans ; Leeches/*microbiology ; Molecular Sequence Data ; Phylogeny ; Providencia/genetics/metabolism ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Vitamins/*metabolism ; }, abstract = {Endosymbiosis is a common phenomenon in nature, especially between bacteria and insects, whose typically unbalanced diets are usually complemented by their obligate endosymbionts. While much interest and focus has been directed toward phloem-feeders like aphids and mealybugs, blood-feeders such as the Lone star tick (Amblyomma americanum), Glossina flies, and the human body louse (Pediculus humanus corporis) depend on obligate endosymbionts which complement their B-vitamin-deficient diets, and thus are required for growth and survival. Glossiphoniid leeches have also been found to harbor distinct endosymbionts housed in specialized organs. Here, we present the genome of the bacterial endosymbiont from Haementeria officinalis, first of a glossiphoniid leech. This as-yet-unnamed endosymbiont belongs to the Gammaproteobacteria, has a pleomorphic shape and is restricted to bacteriocytes. For this bacterial endosymbiont, we propose the name Candidatus Providencia siddallii. This symbiont possesses a highly reduced genome with high A+T content and a reduced set of metabolic capabilities, all of which are common characteristics of ancient obligate endosymbionts of arthropods. Its genome has retained many pathways related to the biosynthesis of B-vitamins, pointing toward a role in supplementing the blood-restricted diet of its host. Through comparative genomics against the endosymbionts of A. americanum, Glossina flies, and P. humanus corporis, we were able to detect a high degree of metabolic convergence among these four very distantly related endosymbiotic bacteria.}, }
@article {pmid26454011, year = {2015}, author = {Moog, D and Rensing, SA and Archibald, JM and Maier, UG and Ullrich, KK}, title = {Localization and Evolution of Putative Triose Phosphate Translocators in the Diatom Phaeodactylum tricornutum.}, journal = {Genome biology and evolution}, volume = {7}, number = {11}, pages = {2955-2969}, pmid = {26454011}, issn = {1759-6653}, mesh = {Amino Acid Sequence ; *Biological Evolution ; Chloroplast Proteins/*genetics ; Diatoms/*genetics ; Molecular Sequence Data ; Monosaccharide Transport Proteins/*genetics ; Phosphates/metabolism ; Phylogeny ; Plastids/genetics ; *Symbiosis ; Trioses/metabolism ; }, abstract = {The establishment of a metabolic connection between host and symbiont is a crucial step in the evolution of an obligate endosymbiotic relationship. Such was the case in the evolution of mitochondria and plastids. Whereas the mechanisms of metabolite shuttling between the plastid and host cytosol are relatively well studied in Archaeplastida-organisms that acquired photosynthesis through primary endosymbiosis-little is known about this process in organisms with complex plastids. Here, we focus on the presence, localization, and phylogeny of putative triose phosphate translocators (TPTs) in the complex plastid of diatoms. These proteins are thought to play an essential role in connecting endosymbiont and host metabolism via transport of carbohydrates generated by the photosynthesis machinery of the endosymbiont. We show that the complex plastid localized TPTs are monophyletic and present a model for how the initial metabolic link between host and endosymbiont might have been established in diatoms and other algae with complex red plastids and discuss its implications on the evolution of those lineages.}, }
@article {pmid26442762, year = {2015}, author = {Gutzwiller, F and Dedeine, F and Kaiser, W and Giron, D and Lopez-Vaamonde, C}, title = {Correlation between the green-island phenotype and Wolbachia infections during the evolutionary diversification of Gracillariidae leaf-mining moths.}, journal = {Ecology and evolution}, volume = {5}, number = {18}, pages = {4049-4062}, pmid = {26442762}, issn = {2045-7758}, abstract = {Internally feeding herbivorous insects such as leaf miners have developed the ability to manipulate the physiology of their host plants in a way to best meet their metabolic needs and compensate for variation in food nutritional composition. For instance, some leaf miners can induce green-islands on yellow leaves in autumn, which are characterized by photosynthetically active green patches in otherwise senescing leaves. It has been shown that endosymbionts, and most likely bacteria of the genus Wolbachia, play an important role in green-island induction in the apple leaf-mining moth Phyllonorycter blancardella. However, it is currently not known how widespread is this moth-Wolbachia-plant interaction. Here, we studied the co-occurrence between Wolbachia and the green-island phenotype in 133 moth specimens belonging to 74 species of Lepidoptera including 60 Gracillariidae leaf miners. Using a combination of molecular phylogenies and ecological data (occurrence of green-islands), we show that the acquisitions of the green-island phenotype and Wolbachia infections have been associated through the evolutionary diversification of Gracillariidae. We also found intraspecific variability in both green-island formation and Wolbachia infection, with some species being able to form green-islands without being infected by Wolbachia. In addition, Wolbachia variants belonging to both A and B supergroups were found to be associated with green-island phenotype suggesting several independent origins of green-island induction. This study opens new prospects and raises new questions about the ecology and evolution of the tripartite association between Wolbachia, leaf miners, and their host plants.}, }
@article {pmid26439354, year = {2015}, author = {Archibald, JM}, title = {Endosymbiosis and Eukaryotic Cell Evolution.}, journal = {Current biology : CB}, volume = {25}, number = {19}, pages = {R911-21}, doi = {10.1016/j.cub.2015.07.055}, pmid = {26439354}, issn = {1879-0445}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {*Biological Evolution ; Eukaryota/*physiology ; Eukaryotic Cells/*physiology ; Evolution, Molecular ; Genomics ; Organelles/*physiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Understanding the evolution of eukaryotic cellular complexity is one of the grand challenges of modern biology. It has now been firmly established that mitochondria and plastids, the classical membrane-bound organelles of eukaryotic cells, evolved from bacteria by endosymbiosis. In the case of mitochondria, evidence points very clearly to an endosymbiont of α-proteobacterial ancestry. The precise nature of the host cell that partnered with this endosymbiont is, however, very much an open question. And while the host for the cyanobacterial progenitor of the plastid was undoubtedly a fully-fledged eukaryote, how - and how often - plastids moved from one eukaryote to another during algal diversification is vigorously debated. In this article I frame modern views on endosymbiotic theory in a historical context, highlighting the transformative role DNA sequencing played in solving early problems in eukaryotic cell evolution, and posing key unanswered questions emerging from the age of comparative genomics.}, }
@article {pmid26434742, year = {2016}, author = {Smanski, MJ and Schlatter, DC and Kinkel, LL}, title = {Leveraging ecological theory to guide natural product discovery.}, journal = {Journal of industrial microbiology &amp; biotechnology}, volume = {43}, number = {2-3}, pages = {115-128}, pmid = {26434742}, issn = {1476-5535}, mesh = {Animals ; Biological Products/*isolation &amp; purification/*metabolism ; *Drug Discovery ; *Ecosystem ; Humans ; *Microbial Interactions ; Phylogeny ; Phylogeography ; Symbiosis ; }, abstract = {Technological improvements have accelerated natural product (NP) discovery and engineering to the point that systematic genome mining for new molecules is on the horizon. NP biosynthetic potential is not equally distributed across organisms, environments, or microbial life histories, but instead is enriched in a number of prolific clades. Also, NPs are not equally abundant in nature; some are quite common and others markedly rare. Armed with this knowledge, random 'fishing expeditions' for new NPs are increasingly harder to justify. Understanding the ecological and evolutionary pressures that drive the non-uniform distribution of NP biosynthesis provides a rational framework for the targeted isolation of strains enriched in new NP potential. Additionally, ecological theory leads to testable hypotheses regarding the roles of NPs in shaping ecosystems. Here we review several recent strain prioritization practices and discuss the ecological and evolutionary underpinnings for each. Finally, we offer perspectives on leveraging microbial ecology and evolutionary biology for future NP discovery.}, }
@article {pmid26431964, year = {2015}, author = {Cohen, EB and Auckland, LD and Marra, PP and Hamer, SA}, title = {Avian migrants facilitate invasions of neotropical ticks and tick-borne pathogens into the United States.}, journal = {Applied and environmental microbiology}, volume = {81}, number = {24}, pages = {8366-8378}, pmid = {26431964}, issn = {1098-5336}, mesh = {*Animal Migration ; Animals ; Bird Diseases/microbiology ; Borrelia burgdorferi/genetics/*isolation &amp; purification ; Female ; Humans ; Ixodes/genetics/*microbiology ; Lyme Disease/transmission ; Male ; Molecular Sequence Data ; Rickettsia/genetics/*isolation &amp; purification ; Rickettsia Infections/transmission ; Songbirds/*microbiology ; Tick-Borne Diseases/*transmission ; United States ; }, abstract = {Migratory birds have the potential to transport exotic vectors and pathogens of human and animal health importance across vast distances. We systematically examined birds that recently migrated to the United States from the Neotropics for ticks. We screened both ticks and birds for tick-borne pathogens, including Rickettsia species and Borrelia burgdorferi. Over two spring seasons (2013 and 2014), 3.56% of birds (n = 3,844) representing 42.35% of the species examined (n = 85) were infested by ticks. Ground-foraging birds with reduced fuel stores were most commonly infested. Eight tick species were identified, including seven in the genus Amblyomma, of which only Amblyomma maculatum/Amblyomma triste is known to be established in the United States. Most ticks on birds (67%) were neotropical species with ranges in Central and South America. Additionally, a single Ixodes genus tick was detected. A total of 29% of the ticks (n = 137) and no avian blood samples (n = 100) were positive for infection with Rickettsia species, including Rickettsia parkeri, an emerging cause of spotted fever in humans in the southern United States, a species in the group of Rickettsia monacensis, and uncharacterized species and endosymbionts of unknown pathogenicity. No avian tick or blood samples tested positive for B. burgdorferi, the etiologic agent of Lyme disease. An extrapolation of our findings suggests that anywhere from 4 to 39 million exotic neotropical ticks are transported to the United States annually on migratory songbirds, with uncertain consequences for human and animal health if the current barriers to their establishment and spread are overcome.}, }
@article {pmid26430060, year = {2016}, author = {Pérez-Escobar, OA and Balbuena, JA and Gottschling, M}, title = {Rumbling Orchids: How To Assess Divergent Evolution Between Chloroplast Endosymbionts and the Nuclear Host.}, journal = {Systematic biology}, volume = {65}, number = {1}, pages = {51-65}, doi = {10.1093/sysbio/syv070}, pmid = {26430060}, issn = {1076-836X}, mesh = {*Biological Evolution ; Chloroplasts/*classification/*genetics ; Classification/*methods ; DNA, Chloroplast/genetics ; DNA, Plant/genetics ; Orchidaceae/*classification/*genetics ; Phylogeny ; Software ; Symbiosis/*genetics ; }, abstract = {Phylogenetic relationships inferred from multilocus organellar and nuclear DNA data are often difficult to resolve because of evolutionary conflicts among gene trees. However, conflicting or "outlier" associations (i.e., linked pairs of "operational terminal units" in two phylogenies) among these data sets often provide valuable information on evolutionary processes such as chloroplast capture following hybridization, incomplete lineage sorting, and horizontal gene transfer. Statistical tools that to date have been used in cophylogenetic studies only also have the potential to test for the degree of topological congruence between organellar and nuclear data sets and reliably detect outlier associations. Two distance-based methods, namely ParaFit and Procrustean Approach to Cophylogeny (PACo), were used in conjunction to detect those outliers contributing to conflicting phylogenies independently derived from chloroplast and nuclear sequence data. We explored their efficiency of retrieving outlier associations, and the impact of input data (unit branch length and additive trees) between data sets, by using several simulation approaches. To test their performance using real data sets, we additionally inferred the phylogenetic relationships within Neotropical Catasetinae (Epidendroideae, Orchidaceae), which is a suitable group to investigate phylogenetic incongruence because of hybridization processes between some of its constituent species. A comparison between trees derived from chloroplast and nuclear sequence data reflected strong, well-supported incongruence within Catasetum, Cycnoches, and Mormodes. As a result, outliers among chloroplast and nuclear data sets, and in experimental simulations, were successfully detected by PACo when using patristic distance matrices obtained from phylograms, but not from unit branch length trees. The performance of ParaFit was overall inferior compared to PACo, using either phylograms or unit branch lengths as input data. Because workflows for applying cophylogenetic analyses are not standardized yet, we provide a pipeline for executing PACo and ParaFit as well as displaying outlier associations in plots and trees by using the software R. The pipeline renders a method to identify outliers with high reliability and to assess the combinability of the independently derived data sets by means of statistical analyses.}, }
@article {pmid26428855, year = {2015}, author = {Raele, DA and Galante, D and Pugliese, N and De Simone, E and Cafiero, MA}, title = {Coxiella-like endosymbiont associated to the "Anatolian brown tick" Rhipicephalus bursa in Southern Italy.}, journal = {Microbes and infection}, volume = {17}, number = {11-12}, pages = {799-805}, doi = {10.1016/j.micinf.2015.09.011}, pmid = {26428855}, issn = {1769-714X}, mesh = {Animals ; Bacterial Proteins/genetics ; Base Sequence ; Coxiella burnetii/classification/*genetics ; DNA Transposable Elements/*genetics ; DNA, Bacterial/genetics ; Female ; In Situ Hybridization, Fluorescence ; Italy ; Polymerase Chain Reaction ; Q Fever/microbiology/*veterinary ; RNA, Ribosomal, 16S/genetics ; Rhipicephalus/*microbiology ; Sequence Analysis, DNA ; Sheep/*microbiology ; Sheep Diseases/*microbiology ; Symbiosis ; }, abstract = {Several different ticks have been reported to harbor microbes related to Coxiella burnetii, the agent of the Q fever. Rhipicephalus bursa is an important vector of tick-borne diseases in livestock in Mediterranean area; it is also abundant in ovi-caprine farms with C. burnetii infection, in Southern Italy. 60 females of Rh. bursa (15 pools) and 40 their eggs (2 pools) were screened for C. burnetii by a conventional PCR targeting the insertion sequence IS1111 and by Loop mediated isothermal amplification assay (LAMP) targeting com1 gene. One of 15 tick pools (1/15) and both egg pools (2/2) were found positive by LAMP assay and negative by PCR targeting IS1111 gene. 16S rRNA gene was amplified by PCR from the LAMP-positive pools, amplicons were sequenced and found 95% similar to the corresponding sequences from C. burnetii. This let us to hypothesize the presence of a new Coxiella-like endosymbiont associated with Rh. bursa which could be vertically transmitted, described here for the first time. The lack of detection of IS1111 in Coxiella endosymbiont of Rh. bursa could be related to the possible absence of the Pathogenicity island of C. burnetii, to which IS1111s are associated.}, }
@article {pmid26427672, year = {2015}, author = {Leyton, DL and Belousoff, MJ and Lithgow, T}, title = {The β-Barrel Assembly Machinery Complex.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {1329}, number = {}, pages = {1-16}, doi = {10.1007/978-1-4939-2871-2_1}, pmid = {26427672}, issn = {1940-6029}, mesh = {Bacterial Outer Membrane Proteins/*chemistry/*metabolism ; Cell Membrane/metabolism ; Periplasm/metabolism ; Protein Folding ; Protein Structure, Secondary ; }, abstract = {The outer membranes of gram-negative bacteria contain integral membrane proteins, most of which are of β-barrel structure, and critical for bacterial survival. These β-barrel proteins rely on the β-barrel assembly machinery (BAM) complex for their integration into the outer membrane as folded species. The central and essential subunit of the BAM complex, BamA, is a β-barrel protein conserved in all gram-negative bacteria and also found in eukaryotic organelles derived from bacterial endosymbionts. In Escherichia coli, BamA docks with four peripheral lipoproteins, BamB, BamC, BamD and BamE, partner subunits that add to the function of the BAM complex in outer membrane protein biogenesis. By way of introduction to this volume, we provide an overview of the work that has illuminated the mechanism by which the BAM complex drives β-barrel assembly. The protocols and methodologies associated with these studies as well as the challenges encountered and their elegant solutions are discussed in subsequent chapters.}, }
@article {pmid26423782, year = {2016}, author = {Łukasiewicz, K and Sanak, M and Węgrzyn, G}, title = {A lack of Wolbachia-specific DNA in samples from apollo butterfly (Parnassius apollo, Lepidoptera: Papilionidae) individuals with deformed or reduced wings.}, journal = {Journal of applied genetics}, volume = {57}, number = {2}, pages = {271-274}, pmid = {26423782}, issn = {2190-3883}, mesh = {Animals ; Butterflies/*microbiology ; DNA, Bacterial/*isolation &amp; purification ; Poland ; Symbiosis ; Wings, Animal/*abnormalities ; Wolbachia/*isolation &amp; purification ; }, abstract = {Various insects contain maternally inherited endosymbiotic bacteria which can cause reproductive alterations, modulation of some physiological responses (like immunity, heat shock response, and oxidative stress response), and resistance to viral infections. In butterflies, Wolbachia sp. is the most frequent endosymbiont from this group, occurring in about 30 % of species tested to date. In this report, the presence of Wolbachia-specific DNA has been detected in apollo butterfly (Parnassius apollo). In the isolated population of this insect occurring in Pieniny National Park (Poland), malformed individuals with deformed or reduced wings appear with an exceptionally high frequency. Interestingly, while total DNA isolated from most (about 85 %) normal insects contained Wolbachia-specific sequences detected by PCR, such sequences were absent in a large fraction (70 %) of individuals with deformed wings and in all tested individuals with reduced wings. These results indicate for the first time the correlation between malformation of wings and the absence of Wolbachia sp. in insects. Although the lack of the endosymbiotic bacteria cannot be considered as the sole cause of the deformation or reduction of wings, one might suggest that Wolbachia sp. could play a protective role in the ontogenetic development of apollo butterfly.}, }
@article {pmid26418631, year = {2016}, author = {Ikuta, T and Takaki, Y and Nagai, Y and Shimamura, S and Tsuda, M and Kawagucci, S and Aoki, Y and Inoue, K and Teruya, M and Satou, K and Teruya, K and Shimoji, M and Tamotsu, H and Hirano, T and Maruyama, T and Yoshida, T}, title = {Heterogeneous composition of key metabolic gene clusters in a vent mussel symbiont population.}, journal = {The ISME journal}, volume = {10}, number = {4}, pages = {990-1001}, pmid = {26418631}, issn = {1751-7370}, mesh = {Animals ; Ecosystem ; *Genes, Bacterial ; Gills ; In Situ Hybridization ; *Multigene Family ; Mytilidae/*microbiology ; Oxygen/chemistry ; Polymerase Chain Reaction ; Seawater/microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Chemosynthetic symbiosis is one of the successful systems for adapting to a wide range of habitats including extreme environments, and the metabolic capabilities of symbionts enable host organisms to expand their habitat ranges. However, our understanding of the adaptive strategies that enable symbiotic organisms to expand their habitats is still fragmentary. Here, we report that a single-ribotype endosymbiont population in an individual of the host vent mussel, Bathymodiolus septemdierum has heterogeneous genomes with regard to the composition of key metabolic gene clusters for hydrogen oxidation and nitrate reduction. The host individual harbours heterogeneous symbiont subpopulations that either possess or lack the gene clusters encoding hydrogenase or nitrate reductase. The proportions of the different symbiont subpopulations in a host appeared to vary with the environment or with the host's development. Furthermore, the symbiont subpopulations were distributed in patches to form a mosaic pattern in the gill. Genomic heterogeneity in an endosymbiont population may enable differential utilization of diverse substrates and confer metabolic flexibility. Our findings open a new chapter in our understanding of how symbiotic organisms alter their metabolic capabilities and expand their range of habitats.}, }
@article {pmid26415499, year = {2015}, author = {de Oliveira, SS and Garcia-Gomes, Ados S and d'Avila-Levy, CM and dos Santos, AL and Branquinha, MH}, title = {Expression of calpain-like proteins and effects of calpain inhibitors on the growth rate of Angomonas deanei wild type and aposymbiotic strains.}, journal = {BMC microbiology}, volume = {15}, number = {}, pages = {188}, pmid = {26415499}, issn = {1471-2180}, mesh = {Bacteria/*growth &amp; development ; Calpain/*antagonists &amp; inhibitors/*biosynthesis/genetics ; Glycoproteins/*metabolism ; *Symbiosis ; Trypanosomatina/drug effects/genetics/*growth &amp; development/*microbiology ; }, abstract = {BACKGROUND: Angomonas deanei is a trypanosomatid parasite of insects that has a bacterial endosymbiont, which supplies amino acids and other nutrients to its host. Bacterium loss induced by antibiotic treatment of the protozoan leads to an aposymbiotic strain with increased need for amino acids and results in increased production of extracellular peptidases. In this work, a more detailed examination of A. deanei was conducted to determine the effects of endosymbiont loss on the host calpain-like proteins (CALPs), followed by testing of different calpain inhibitors on parasite proliferation.<br><br>RESULTS: Western blotting showed the presence of different protein bands reactive to antibodies against calpain from Drosophila melanogaster (anti-Dm-calpain), lobster calpain (anti-CDPIIb) and cytoskeleton-associated calpain from Trypanosoma brucei (anti-CAP5.5), suggesting a possible modulation of CALPs influenced by the endosymbiont. In the cell-free culture supernatant of A. deanei wild type and aposymbiotic strains, a protein of 80&#xa0;kDa cross-reacted with the anti-Dm-calpain antibody; however, no cross-reactivity was found with anti-CAP5.5 and anti-CDPIIb antibodies. A search in A. deanei genome for homologues of D. melanogaster calpain, T. brucei CAP5.5 and lobster CDPIIb calpain revealed the presence of hits with at least one calpain conserved domain and also with theoretical molecular mass consistent with the recognition by each antibody. No significant hit was observed in the endosymbiont genome, indicating that calpain molecules might be absent from the symbiont. Flow cytometry analysis of cells treated with the anti-calpain antibodies showed that a larger amount of reactive epitopes was located intracellularly. The reversible calpain inhibitor MDL28170 displayed a much higher efficacy in diminishing the growth of both strains compared to the non-competitive calpain inhibitor PD150606, while the irreversible calpain inhibitor V only marginally diminished the proliferation.<br><br>CONCLUSIONS: Altogether, these results indicate that distinct calpain-like molecules are expressed by A. deanei, with a possible modulation in the expression influenced by the endosymbiont. In addition, treatment with MDL28170 affects the growth rate of both strains, as previously determined in the human pathogenic species Leishmania amazonensis and Trypanosoma cruzi, with whom A. deanei shares immunological and biochemical relationships.}, }
@article {pmid26414414, year = {2015}, author = {Blackall, LL and Wilson, B and van Oppen, MJ}, title = {Coral-the world's most diverse symbiotic ecosystem.}, journal = {Molecular ecology}, volume = {24}, number = {21}, pages = {5330-5347}, doi = {10.1111/mec.13400}, pmid = {26414414}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/genetics/*microbiology ; Archaea/classification ; Bacteria/*classification ; Biodiversity ; *Coral Reefs ; DNA, Bacterial/genetics ; DNA, Ribosomal Spacer/genetics ; Dinoflagellida/*classification ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Zooxanthellate corals (i.e. those harbouring Symbiodinium) are the main builders of the world's shallow-water marine coral reefs. They represent intimate diverse symbioses between coral animals, single-celled photosynthetic dinoflagellates (Symbiodinium spp.), other microscopic eukaryotes, prokaryotes and viruses. Crabs and other crustaceans, worms, sponges, bivalves and hydrozoans, fishes, sea urchins, octopuses and sea stars are itinerant members of these 'rainforests of the sea'. This review focuses on the biodiversity of scleractinian coral animals and their best studied microscopic epi- and endosymbionts. In relation to coral-associated species diversity, Symbiodinium internal transcribed spacer region sequence types tally 10(2) -10(3) or up to ~15 different operational taxonomic units (OTUs, or putative species at the 97% sequence identity level; this cut-off was chosen based on intragenomic sequence diversity observed in monoclonal cultures) and prokaryotes (mostly bacterial) total 10(2) -10(4) OTUs. We analysed all publically accessible 16S rRNA gene sequence data and found Gammaproteobacteria were extremely abundant, followed by Alphaproteobacteria. Notably, Archaea were poorly represented and 'unassigned OTUs' were abundant in data generated by high-throughput DNA sequencing studies of corals. We outline and compare model systems that could be used in future studies of the coral holobiont. In our future directions, we recommend a global coral sampling effort including substantial attention being paid to method of coral tissue acquisition, which compartments (mucus, tissue, skeleton) to explore, broadening the holobiont members considered and linking biodiversity with functional investigations.}, }
@article {pmid26411784, year = {2015}, author = {Zhou, W and Nan, X and Zheng, Z and Wei, C and He, H}, title = {Analysis of Inter-Individual Bacterial Variation in Gut of Cicada Meimuna mongolica (Hemiptera: Cicadidae).}, journal = {Journal of insect science (Online)}, volume = {15}, number = {1}, pages = {}, pmid = {26411784}, issn = {1536-2442}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Female ; Gastrointestinal Tract/*microbiology ; Hemiptera/*microbiology ; Male ; Nymph/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Intestinal bacterial community plays a crucial role in the nutrition, development, survival, and reproduction of insects. When compared with other insects with piercing-sucking mouthparts, the habitats of cicada nymphs and adults are totally different. However, little is known about the differences in the gut bacterial communities in the nymphs and adults within any cicada species. The diversity of bacteria in the gut of nymphs and adults of both genders of Meimuna mongolica (Distant) was studied using the denaturing gradient gel electrophoresis (DGGE) method. Few inter-individual variations among gut microbiota were observed, suggesting that M. mongolica typically harbors a limited and consistent suite of bacterial species. Bacteria in the genera Pseudomonas and Enterobacter were the predominant components of the gut microflora of M. mongolica at all life stages. Bacteria of Pantoea, Streptococcus, and Uruburuella were also widespread in the cicada samples but at relatively lower concentrations. The relative stability and similarity of the PCR-DGGE patterns indicate that all individuals of this cicada species harbor a characteristic bacterial community which is independent from developmental stages and genders. Related endosymbionts that could be harbored in bacteromes of cicadas were not detected in any gut samples, which could be related to the cicada species and the distribution of these endosymbionts in the cicada cavity, or due to some of the possible limitations of PCR-DGGE community profiling. It is worthwhile to further address if related cicada endosymbiont clades distribute in the alimentary canals and other internal organs through diagnostic PCR using group-specific primer sets.}, }
@article {pmid26410254, year = {2015}, author = {Saeed, A and White, JA}, title = {Surveys for maternally-inherited endosymbionts reveal novel and variable infections within solitary bee species.}, journal = {Journal of invertebrate pathology}, volume = {132}, number = {}, pages = {111-114}, doi = {10.1016/j.jip.2015.09.011}, pmid = {26410254}, issn = {1096-0805}, mesh = {Animals ; Bees/*microbiology ; Enterobacteriaceae/isolation &amp; purification/*physiology ; Gammaproteobacteria/isolation &amp; purification/*physiology ; *Host-Pathogen Interactions ; Population Dynamics ; Symbiosis ; Wolbachia/isolation &amp; purification/*physiology ; }, abstract = {Maternally-inherited bacteria can affect the fitness and population dynamics of their host insects; for solitary bees, such effects have the potential to influence bee efficacy as pollinators. We screened bee species for bacterial associates using 454-pyrosequencing (4 species) and diagnostic PCR (183 specimens across 29 species). The endosymbiont Wolbachia was abundant, infecting 18 species, including all specimens from the family Halictidae. Among commercially-supplied orchard bees (family Megachilidae), only 2/7 species were Wolbachia-infected, but one species showed variable infection among specimens. Two other maternally-inherited bacteria, Arsenophonus and Sodalis, were also detected, neither of which was fixed in infection frequency. Differential endosymbiont infection could potentially compromise fitness and reproductive compatibility among commercially redistributed pollinator populations.}, }
@article {pmid26401040, year = {2015}, author = {Petro, TM and Agarkova, IV and Zhou, Y and Yolken, RH and Van Etten, JL and Dunigan, DD}, title = {Response of Mammalian Macrophages to Challenge with the Chlorovirus Acanthocystis turfacea Chlorella Virus 1.}, journal = {Journal of virology}, volume = {89}, number = {23}, pages = {12096-12107}, pmid = {26401040}, issn = {1098-5514}, support = {P30 RR031151/RR/NCRR NIH HHS/United States ; P30RR031151/RR/NCRR NIH HHS/United States ; }, mesh = {Analysis of Variance ; Animals ; Annexin A5/metabolism ; Antibodies, Viral/immunology ; Blotting, Western ; Capsid Proteins/biosynthesis ; Caspase 3/metabolism ; Cell Line ; Cognition Disorders/immunology/*virology ; DNA Primers/genetics ; Electrophoresis, Polyacrylamide Gel ; Enzyme Activation/physiology ; Female ; Flow Cytometry ; Immunoblotting ; In Vitro Techniques ; Interleukin-6/metabolism ; Macrophages/immunology/*virology ; Mice ; Mice, Inbred C57BL ; Nitric Oxide/metabolism ; Phycodnaviridae/*immunology ; Real-Time Polymerase Chain Reaction ; Time Factors ; }, abstract = {UNLABELLED: It was recently reported that 44% of the oropharyngeal samples from the healthy humans in a study cohort had DNA sequences similar to that of the chlorovirus ATCV-1 (Acanthocystis turfacea chlorella virus 1, family Phycodnaviridae) and that these study subjects had decreases in visual processing and visual motor speed compared with individuals in whom no virus was detected. Moreover, mice inoculated orally with ATCV-1 developed immune responses to ATCV-1 proteins and had decreases in certain cognitive domains. Because heightened interleukin-6 (IL-6), nitric oxide (NO), and ERK mitogen-activated protein (MAP) kinase activation from macrophages are linked to cognitive impairments, we evaluated cellular responses and viral PFU counts in murine RAW264.7 cells and primary macrophages after exposure to ATCV-1 in vitro for up to 72 h after a virus challenge. Approximately 8% of the ATCV-1 inoculum was associated with macrophages after 1 h, and the percentage increased 2- to 3-fold over 72 h. Immunoblot assays with rabbit anti-ATCV-1 antibody detected a 55-kDa protein consistent with the viral capsid protein from 1 to 72 h and increasing de novo synthesis of a previously unidentified 17-kDa protein beginning at 24 h. Emergence of the 17-kDa protein did not occur and persistence of the 55-kDa protein declined over time when cells were exposed to heat-inactivated ATCV-1. Moreover, starting at 24 h, RAW264.7 cells exhibited cytopathic effects, annexin V staining, and cleaved caspase 3. Activation of ERK MAP kinases occurred in these cells by 30 min postchallenge, which preceded the expression of IL-6 and NO. Therefore, ATCV-1 persistence in and induction of inflammatory factors by these macrophages may contribute to declines in the cognitive abilities of mice and humans.<br><br>IMPORTANCE: Virus infections that persist in and stimulate inflammatory factors in macrophages contribute to pathologies in humans. A previous study showed that DNA sequences homologous to the chlorovirus ATCV-1 were found in a significant fraction of oropharyngeal samples from a healthy human cohort. We show here that ATCV-1, whose only known host is a eukaryotic green alga (Chlorella heliozoae) that is an endosymbiont of the heliozoon Acanthocystis turfacea, can unexpectedly persist within murine macrophages and trigger inflammatory responses including factors that contribute to immunopathologies. The inflammatory factors that are produced in response to ATCV-1 include IL-6 and NO, whose induction is preceded by the activation of ERK MAP kinases. Other responses of ATCV-1-challenged macrophages include an apoptotic cytopathic effect, an innate antiviral response, and a metabolic shift toward aerobic glycolysis. Therefore, mammalian encounters with chloroviruses may contribute to chronic inflammatory responses from macrophages.}, }
@article {pmid26400107, year = {2016}, author = {Baldridge, GD and Li, YG and Witthuhn, BA and Higgins, L and Markowski, TW and Baldridge, AS and Fallon, AM}, title = {Mosaic composition of ribA and wspB genes flanking the virB8-D4 operon in the Wolbachia supergroup B-strain, wStr.}, journal = {Archives of microbiology}, volume = {198}, number = {1}, pages = {53-69}, pmid = {26400107}, issn = {1432-072X}, support = {R01 AI081322/AI/NIAID NIH HHS/United States ; AI 081322/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Genes, Bacterial/*genetics ; Operon/genetics ; Proteomics ; Wolbachia/*genetics ; }, abstract = {The obligate intracellular bacterium, Wolbachia pipientis (Rickettsiales), is a widespread, vertically transmitted endosymbiont of filarial nematodes and arthropods. In insects, Wolbachia modifies reproduction, and in mosquitoes, infection interferes with replication of arboviruses, bacteria and plasmodia. Development of Wolbachia as a tool to control pest insects will be facilitated by an understanding of molecular events that underlie genetic exchange between Wolbachia strains. Here, we used nucleotide sequence, transcriptional and proteomic analyses to evaluate expression levels and establish the mosaic nature of genes flanking the T4SS virB8-D4 operon from wStr, a supergroup B-strain from a planthopper (Hemiptera) that maintains a robust, persistent infection in an Aedes albopictus mosquito cell line. Based on protein abundance, ribA, which contains promoter elements at the 5'-end of the operon, is weakly expressed. The 3'-end of the operon encodes an intact wspB, which encodes an outer membrane protein and is co-transcribed with the vir genes. WspB and vir proteins are expressed at similar, above average abundance levels. In wStr, both ribA and wspB are mosaics of conserved sequence motifs from Wolbachia supergroup A- and B-strains, and wspB is nearly identical to its homolog from wCobU4-2, an A-strain from weevils (Coleoptera). We describe conserved repeated sequence elements that map within or near pseudogene lesions and transitions between A- and B-strain motifs. These studies contribute to ongoing efforts to explore interactions between Wolbachia and its host cell in an in vitro system.}, }
@article {pmid26398775, year = {2015}, author = {Di Venere, M and Fumagalli, M and Cafiso, A and De Marco, L and Epis, S and Plantard, O and Bardoni, A and Salvini, R and Viglio, S and Bazzocchi, C and Iadarola, P and Sassera, D}, title = {Ixodes ricinus and Its Endosymbiont Midichloria mitochondrii: A Comparative Proteomic Analysis of Salivary Glands and Ovaries.}, journal = {PloS one}, volume = {10}, number = {9}, pages = {e0138842}, pmid = {26398775}, issn = {1932-6203}, mesh = {Animals ; Blotting, Western ; Electrophoresis, Gel, Two-Dimensional ; Female ; Hydrogen-Ion Concentration ; Ixodes/*metabolism/parasitology ; Ovary/*metabolism ; Polymerase Chain Reaction ; *Proteomics ; Rickettsiaceae/*metabolism ; Salivary Glands/*metabolism ; }, abstract = {Hard ticks are hematophagous arthropods that act as vectors of numerous pathogenic microorganisms of high relevance in human and veterinary medicine. Ixodes ricinus is one of the most important tick species in Europe, due to its role of vector of pathogenic bacteria such as Borrelia burgdorferi and Anaplasma phagocytophilum, of viruses such as tick borne encephalitis virus and of protozoans as Babesia spp. In addition to these pathogens, I. ricinus harbors a symbiotic bacterium, Midichloria mitochondrii. This is the dominant bacteria associated to I. ricinus, but its biological role is not yet understood. Most M. mitochondrii symbionts are localized in the tick ovaries, and they are transmitted to the progeny. M. mitochondrii bacteria have however also been detected in the salivary glands and saliva of I. ricinus, as well as in the blood of vertebrate hosts of the tick, prompting the hypothesis of an infectious role of this bacterium. To investigate, from a proteomic point of view, the tick I. ricinus and its symbiont, we generated the protein profile of the ovary tissue (OT) and of salivary glands (SG) of adult females of this tick species. To compare the OT and SG profiles, 2-DE profiling followed by LC-MS/MS protein identification were performed. We detected 21 spots showing significant differences in the relative abundance between the OT and SG, ten of which showed 4- to 18-fold increase/decrease in density. This work allowed to establish a method to characterize the proteome of I. ricinus, and to detect multiple proteins that exhibit a differential expression profile in OT and SG. Additionally, we were able to use an immunoproteomic approach to detect a protein from the symbiont. Finally, the method here developed will pave the way for future studies on the proteomics of I. ricinus, with the goals of better understanding the biology of this vector and of its symbiont M. mitochondrii.}, }
@article {pmid28357263, year = {2015}, author = {Rajkovic, A and Witzky, A and Navarre, W and Darwin, AJ and Ibba, M}, title = {Elongation factor-P at the crossroads of the host-endosymbiont interface.}, journal = {Microbial cell (Graz, Austria)}, volume = {2}, number = {10}, pages = {360-362}, pmid = {28357263}, issn = {2311-2638}, support = {R01 GM065183/GM/NIGMS NIH HHS/United States ; }, abstract = {Elongation factor P (EF-P) is an ancient bacterial translational factor that aids the ribosome in polymerizing oligo-prolines. EF-P structurally resembles tRNA and binds in-between the exit and peptidyl sites of the ribosome to accelerate the intrinsically slow reaction of peptidyl-prolyl bond formation. Recent studies have identified in separate organisms, two evolutionarily convergent EF-P post-translational modification systems (EPMS), split predominantly between gammaproteobacteria, and betaproteobacteria. In both cases EF-P receives a post-translational modification, critical for its function, on a highly conserved residue that protrudes into the peptidyl-transfer center of the ribosome. EPMSs are comprised of a gene(s) that synthesizes the precursor molecule used in modifying EF-P, and a gene(s) encoding an enzyme that reacts with the precursor molecule to catalyze covalent attachment to EF-P. However, not all organisms genetically encode a complete EPMS. For instance, some symbiotic bacteria harbor efp and the corresponding gene that enzymatically attaches the modification, but lack the ability to synthesize the substrate used in the modification reaction. Here we highlight the recent discoveries made regarding EPMSs, with a focus on how these incomplete modification pathways shape or have been shaped by the endosymbiont-host relationship.}, }
@article {pmid26385192, year = {2015}, author = {Morrow, JL and Frommer, M and Royer, JE and Shearman, DC and Riegler, M}, title = {Wolbachia pseudogenes and low prevalence infections in tropical but not temperate Australian tephritid fruit flies: manifestations of lateral gene transfer and endosymbiont spillover?.}, journal = {BMC evolutionary biology}, volume = {15}, number = {}, pages = {202}, pmid = {26385192}, issn = {1471-2148}, mesh = {Animals ; Australia ; Cloning, Molecular ; Gene Transfer, Horizontal ; Haplotypes ; Multilocus Sequence Typing ; Phylogeny ; Pseudogenes ; Tephritidae/*classification/*microbiology/physiology ; Wolbachia/*genetics/*isolation &amp; purification/physiology ; }, abstract = {BACKGROUND: Maternally inherited Wolbachia bacteria infect many insect species. They can also be transferred horizontally into uninfected host lineages. A Wolbachia spillover from an infected source population must occur prior to the establishment of heritable infections, but this spillover may be transient. In a previous study of tephritid fruit fly species of tropical Australia we detected a high incidence of identical Wolbachia strains in several species as well as Wolbachia pseudogenes. Here, we have investigated this further by analysing field specimens of 24 species collected along a 3,000 km climate gradient of eastern Australia.<br><br>RESULTS: Wolbachia sequences were detected in individuals of nine of the 24 (37 %) species. Seven (29 %) species displayed four distinct Wolbachia strains based on characterisation of full multi locus sequencing (MLST) profiles; the strains occurred as single and double infections in a small number of individuals (2-17 %). For the two remaining species all individuals had incomplete MLST profiles and Wolbachia pseudogenes that may be indicative of lateral gene transfer into host genomes. The detection of Wolbachia was restricted to northern Australia, including in five species that only occur in the tropics. Within the more widely distributed Bactrocera tryoni and Bactrocera neohumeralis, Wolbachia also only occurred in the north, and was not linked to any particular mitochondrial haplotypes.<br><br>CONCLUSIONS: The presence of Wolbachia pseudogenes at high prevalence in two species in absence of complete MLST profiles may represent footprints of historic infections that have been lost. The detection of identical low prevalence strains in a small number of individuals of seven species may question their role as reproductive manipulator and their vertical inheritance. Instead, the findings may be indicative of transient infections that result from spillover events from a yet unknown source. These spillover events appear to be restricted to northern Australia, without proliferation in host lineages further south. Our study highlights that tropical fruit fly communities contain Wolbachia pseudogenes and may be exposed to frequent horizontal Wolbachia transfer. It also emphasises that global estimates of Wolbachia frequencies may need to consider lateral gene transfer and Wolbachia spillover that may be regionally restricted, transient and not inherited.}, }
@article {pmid26381539, year = {2016}, author = {Senra, MV and Dias, RJ and Castelli, M and Silva-Neto, ID and Verni, F and Soares, CA and Petroni, G}, title = {A House for Two--Double Bacterial Infection in Euplotes woodruffi Sq1 (Ciliophora, Euplotia) Sampled in Southeastern Brazil.}, journal = {Microbial ecology}, volume = {71}, number = {2}, pages = {505-517}, pmid = {26381539}, issn = {1432-184X}, mesh = {Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Brazil ; Euplotes/classification/*microbiology/physiology ; Host Specificity ; Molecular Sequence Data ; Phylogeny ; Symbiosis ; }, abstract = {Several ciliated protists form symbiotic associations with a diversity of microorganisms, leading to drastic impact on their ecology and evolution. In this work, two Euplotes spp. sampled in Rio de Janeiro, Brazil, were identified based on morphological and molecular features as Euplotes woodruffi strain Sq1 and E. encysticus strain Sq2 and investigated for the presence of endosymbionts. While E. woodruffi Sq1 stably hosts two bacterial populations, namely Polynucleobacter necessarius (Betaproteobacteria) and a new member of the family "Candidatus Midichloriaceae" (Alphaproteobacteria, Rickettsiales), here described as "Candidatus Bandiella woodruffii," branching with a broad host range bacterial group found in association with cnidarians, sponges, euglenoids, and some arthropods; in E. encysticus Sq2 no symbiotic bacterium could be detected. The dispersion ability of this novel bacterium was tested by co-incubating E. woodruffi Sq1 with three different ciliate species. Among the tested strains "Ca. B. woodruffii" could only be detected in association with E. encysticus Sq2 with a prevalence of 20 % after 1 week and 40 % after 2 weeks, maintaining this level for up to 6 months. Nevertheless, this apparent in vitro association was abolished when E. woodruffi Sq1 donor was removed from the microcosm, suggesting that this bacterium has the capacity for at least a short-term survival outside its natural host and the aptitude to ephemerally interact with other organisms. Together, these findings strongly suggest the need for more detailed investigations to evaluate the host range for "Ca. B. woodruffii" and any possible pathogenic effect of this bacterium on other organisms including humans.}, }
@article {pmid26379285, year = {2015}, author = {Tausch, SH and Renard, BY and Nitsche, A and Dabrowski, PW}, title = {RAMBO-K: Rapid and Sensitive Removal of Background Sequences from Next Generation Sequencing Data.}, journal = {PloS one}, volume = {10}, number = {9}, pages = {e0137896}, pmid = {26379285}, issn = {1932-6203}, mesh = {Algorithms ; Datasets as Topic ; Genome/genetics ; Genomics/*methods ; High-Throughput Nucleotide Sequencing/methods ; Programming Languages ; Sequence Analysis, DNA/*methods ; Software ; }, abstract = {BACKGROUND: The assembly of viral or endosymbiont genomes from Next Generation Sequencing (NGS) data is often hampered by the predominant abundance of reads originating from the host organism. These reads increase the memory and CPU time usage of the assembler and can lead to misassemblies.<br><br>RESULTS: We developed RAMBO-K (Read Assignment Method Based On K-mers), a tool which allows rapid and sensitive removal of unwanted host sequences from NGS datasets. Reaching a speed of 10 Megabases/s on 4 CPU cores and a standard hard drive, RAMBO-K is faster than any tool we tested, while showing a consistently high sensitivity and specificity across different datasets.<br><br>CONCLUSIONS: RAMBO-K rapidly and reliably separates reads from different species without data preprocessing. It is suitable as a straightforward standard solution for workflows dealing with mixed datasets. Binaries and source code (java and python) are available from http://sourceforge.net/projects/rambok/.}, }
@article {pmid26378568, year = {2015}, author = {Bolling, BG and Weaver, SC and Tesh, RB and Vasilakis, N}, title = {Insect-Specific Virus Discovery: Significance for the Arbovirus Community.}, journal = {Viruses}, volume = {7}, number = {9}, pages = {4911-4928}, pmid = {26378568}, issn = {1999-4915}, support = {HHSN272201000040I/AI/NIAID NIH HHS/United States ; HHSN272201000040I/HHSN27200004/D04//PHS HHS/United States ; }, mesh = {Animals ; Arbovirus Infections/prevention &amp; control/transmission ; Culicidae/*virology ; Entomology/trends ; Humans ; Mosquito Control/methods/trends ; Virology/trends ; Viruses/*isolation &amp; purification ; }, abstract = {Arthropod-borne viruses (arboviruses), especially those transmitted by mosquitoes, are a significant cause of morbidity and mortality in humans and animals worldwide. Recent discoveries indicate that mosquitoes are naturally infected with a wide range of other viruses, many within taxa occupied by arboviruses that are considered insect-specific. Over the past ten years there has been a dramatic increase in the literature describing novel insect-specific virus detection in mosquitoes, which has provided new insights about viral diversity and evolution, including that of arboviruses. It has also raised questions about what effects the mosquito virome has on arbovirus transmission. Additionally, the discovery of these new viruses has generated interest in their potential use as biological control agents as well as novel vaccine platforms. The arbovirus community will benefit from the growing database of knowledge concerning these newly described viral endosymbionts, as their impacts will likely be far reaching.}, }
@article {pmid26366194, year = {2015}, author = {Hoffmann, AA and Ross, PA and Rašić, G}, title = {Wolbachia strains for disease control: ecological and evolutionary considerations.}, journal = {Evolutionary applications}, volume = {8}, number = {8}, pages = {751-768}, pmid = {26366194}, issn = {1752-4571}, abstract = {Wolbachia are endosymbionts found in many insects with the potential to suppress vectorborne diseases, particularly through interfering with pathogen transmission. Wolbachia strains are highly variable in their effects on hosts, raising the issue of which attributes should be selected to ensure that the best strains are developed for disease control. This depends on their ability to suppress viral transmission, invade host populations, persist without loss of viral suppression and not interfere with other control strategies. The potential to achieve these objectives is likely to involve evolutionary constraints; viral suppression may be limited by the ability of infections to spread due to deleterious host fitness effects. However, there are exceptions to these patterns in both natural infections and in novel associations generated following interspecific transfer, suggesting that pathogen blockage, deleterious fitness effects and changes to reproductive biology might be at least partly decoupled to achieve ideal infection attributes. The stability of introduced Wolbachia and its effects on viral transmission remain unclear, but rapid evolutionary changes seem unlikely. Although deliberate transfers of Wolbachia across species remain particularly challenging, the availability of strains with desirable attributes should be expanded, taking advantage of the diversity available across thousands of strains in natural populations.}, }
@article {pmid26362082, year = {2015}, author = {Brown, AM and Howe, DK and Wasala, SK and Peetz, AB and Zasada, IA and Denver, DR}, title = {Comparative Genomics of a Plant-Parasitic Nematode Endosymbiont Suggest a Role in Nutritional Symbiosis.}, journal = {Genome biology and evolution}, volume = {7}, number = {9}, pages = {2727-2746}, pmid = {26362082}, issn = {1759-6653}, mesh = {Animals ; Gene Ontology ; *Genome, Bacterial ; Genomics ; In Situ Hybridization, Fluorescence ; Nematoda/*microbiology ; Nutritional Physiological Phenomena/genetics ; Phylogeny ; Pseudogenes ; *Symbiosis ; Verrucomicrobia/classification/*genetics ; Vitis/parasitology ; }, abstract = {Bacterial mutualists can modulate the biochemical capacity of animals. Highly coevolved nutritional mutualists do this by synthesizing nutrients missing from the host's diet. Genomics tools have advanced the study of these partnerships. Here we examined the endosymbiont Xiphinematobacter (phylum Verrucomicrobia) from the dagger nematode Xiphinema americanum, a migratory ectoparasite of numerous crops that also vectors nepovirus. Previously, this endosymbiont was identified in the gut, ovaries, and eggs, but its role was unknown. We explored the potential role of this symbiont using fluorescence in situ hybridization, genome sequencing, and comparative functional genomics. We report the first genome of an intracellular Verrucomicrobium and the first exclusively intracellular non-Wolbachia nematode symbiont. Results revealed that Xiphinematobacter had a small 0.916-Mb genome with only 817 predicted proteins, resembling genomes of other mutualist endosymbionts. Compared with free-living relatives, conserved proteins were shorter on average, and there was large-scale loss of regulatory pathways. Despite massive gene loss, more genes were retained for biosynthesis of amino acids predicted to be essential to the host. Gene ontology enrichment tests showed enrichment for biosynthesis of arginine, histidine, and aromatic amino acids, as well as thiamine and coenzyme A, diverging from the profiles of relatives Akkermansia muciniphilia (in the human colon), Methylacidiphilum infernorum, and the mutualist Wolbachia from filarial nematodes. Together, these features and the location in the gut suggest that Xiphinematobacter functions as a nutritional mutualist, supplementing essential nutrients that are depleted in the nematode diet. This pattern points to evolutionary convergence with endosymbionts found in sap-feeding insects.}, }
@article {pmid26357541, year = {2015}, author = {O'Shea, KL and Singh, ND}, title = {Tetracycline-exposed Drosophila melanogaster males produce fewer offspring but a relative excess of sons.}, journal = {Ecology and evolution}, volume = {5}, number = {15}, pages = {3130-3139}, pmid = {26357541}, issn = {2045-7758}, abstract = {A large diversity of species possesses endosymbionts; these endosymbionts can exhibit mutualistic, parasitic, and commensal relationships with their hosts. Previous work has consistently revealed that depleting endosymbiont titer with antibiotic treatment can significantly alter host fitness and function, particularly with respect to reproductive phenotypes. Although these findings are often interpreted as resulting from the breakdown of highly coevolved symbioses, it is possible that antibiotic treatment itself rather than endosymbiont removal contributes to the observed perturbations in reproductive phenotypes. Here, we investigate the effect of tetracycline treatment on sex ratio and male reproductive fitness using Drosophila melanogaster as a model system. Our results indicate that tetracycline-treated males produce a relative excess of sons. We also find that tetracycline treatment reduces the number of progeny produced by treated males but not treated females. These findings are independent of the effects of tetracycline on Wolbachia titer and implicate the antibiotic itself as mediating these changes. It is yet unclear whether the sex ratio shift and reduction in male reproductive fitness are direct or indirect consequences of tetracycline exposure, and more work is needed to determine the molecular mechanisms by which these disturbances in reproductive phenotypes arise. Our data highlight the importance of considering the potentially confounding effects of antibiotic treatment when investigating the effects of endosymbiont depletion on host phenotypes.}, }
@article {pmid26350613, year = {2015}, author = {Lau, YL and Lee, WC and Xia, J and Zhang, G and Razali, R and Anwar, A and Fong, MY}, title = {Draft genome of Brugia pahangi: high similarity between B. pahangi and B. malayi.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {451}, pmid = {26350613}, issn = {1756-3305}, mesh = {Adenosine Triphosphatases/genetics/metabolism ; Aedes/parasitology ; Animals ; Bacterial Proteins/genetics/metabolism ; Brugia pahangi/*genetics ; Gene Expression Regulation/physiology ; Genome, Helminth/*genetics ; Helminth Proteins/genetics/metabolism ; Phylogeny ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {BACKGROUND: Efforts to completely eradicate lymphatic filariasis from human population may be challenged by the emergence of Brugia pahangi as another zoonotic lymphatic filarial nematode. In this report, a genomic study was conducted to understand this species at molecular level.<br><br>METHODS: After blood meal on a B. pahangi-harbouring cat, the Aedes togoi mosquitoes were maintained to harvest infective third stage larvae, which were then injected into male Mongolian gerbils. Subsequently, adult B. pahangi were obtained from the infected gerbil for genomic DNA extraction. Sequencing and subsequently, construction of genomic libraries were performed. This was followed by genomic analyses and gene annotation analysis. By using archived protein sequences of B. malayi and a few other nematodes, clustering of gene orthologs and phylogenetics were conducted.<br><br>RESULTS: A total of 9687 coding genes were predicted. The genome of B. pahangi shared high similarity to that B. malayi genome, particularly genes annotated to fundamental processes. Nevertheless, 166 genes were considered to be unique to B. pahangi, which may be responsible for the distinct properties of B. pahangi as compared to other filarial nematodes. In addition, 803 genes were deduced to be derived from Wolbachia, an endosymbiont bacterium, with 44 of these genes intercalate into the nematode genome.<br><br>CONCLUSIONS: The reporting of B. pahangi draft genome contributes to genomic archive. Albeit with high similarity to B. malayi genome, the B. pahangi-unique genes found in this study may serve as new focus to study differences in virulence, vector selection and host adaptability among different Brugia spp.}, }
@article {pmid26349239, year = {2015}, author = {Varshavskiy, AA and Varshavskiy, AA}, title = {[Cellobiohydrolase Activity in the Digestive Tract of two African Rodent Species the African Grass Rat Arvicanthis niloticus and Vlei Rat Otomys helleri].}, journal = {Izvestiia Akademii nauk. Seriia biologicheskaia}, volume = {}, number = {3}, pages = {326-330}, pmid = {26349239}, issn = {1026-3470}, mesh = {*Adaptation, Physiological ; Animals ; Cellulose 1,4-beta-Cellobiosidase/*metabolism ; Digestion ; Gastrointestinal Tract/enzymology ; Herbivory ; Muridae/*physiology ; }, abstract = {Cellobiohydrolase activity (CBHA) of endosymbionts in the digestive tract of two African rodent species differing in its morphology and in feeding specialization--Arvicanthis niloticus and Otomys helleri--has been studied as a characteristic of their physiological and ecological adaptation to phytophagy A statistically significant correlation of CBHA with obesity has been revealed in A. niloticus, with the CBHA level being significantly higher in corpus ceci than in ampulla ceci. The possible morphophysiological and ecological significance of the observed features of symbiotic digestion are discussed.}, }
@article {pmid26347282, year = {2015}, author = {Wang, X and Ryu, D and Houtkooper, RH and Auwerx, J}, title = {Antibiotic use and abuse: a threat to mitochondria and chloroplasts with impact on research, health, and environment.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {37}, number = {10}, pages = {1045-1053}, pmid = {26347282}, issn = {1521-1878}, support = {638290/ERC_/European Research Council/International ; R01 AG043930/AG/NIA NIH HHS/United States ; R01AG043930/AG/NIA NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Biomedical Research/standards ; Chloroplasts/drug effects ; Environment ; Health ; Humans ; Mice ; Mitochondria/drug effects ; Prescription Drug Misuse/*adverse effects ; }, abstract = {Recently, several studies have demonstrated that tetracyclines, the antibiotics most intensively used in livestock and that are also widely applied in biomedical research, interrupt mitochondrial proteostasis and physiology in animals ranging from round worms, fruit flies, and mice to human cell lines. Importantly, plant chloroplasts, like their mitochondria, are also under certain conditions vulnerable to these and other antibiotics that are leached into our environment. Together these endosymbiotic organelles are not only essential for cellular and organismal homeostasis stricto sensu, but also have an important role to play in the sustainability of our ecosystem as they maintain the delicate balance between autotrophs and heterotrophs, which fix and utilize energy, respectively. Therefore, stricter policies on antibiotic usage are absolutely required as their use in research confounds experimental outcomes, and their uncontrolled applications in medicine and agriculture pose a significant threat to a balanced ecosystem and the well-being of these endosymbionts that are essential to sustain health.}, }
@article {pmid26346455, year = {2015}, author = {Špitalská, E and Boldiš, V and Mošanský, L and Sparagano, O and Stanko, M}, title = {Rickettsia species in fleas collected from small mammals in Slovakia.}, journal = {Parasitology research}, volume = {114}, number = {11}, pages = {4333-4339}, pmid = {26346455}, issn = {1432-1955}, mesh = {Animals ; Cats ; Flea Infestations/epidemiology/parasitology/*veterinary ; Male ; Mammals/*parasitology ; Murinae ; Rickettsia/classification/genetics/*isolation &amp; purification/physiology ; Shrews ; Siphonaptera/*microbiology/physiology ; Slovakia ; }, abstract = {Epidemiological and epizootiological studies of Rickettsia felis and other Rickettsia spp. are very important, because their natural cycle has not yet been established completely. In total, 315 fleas (Siphonaptera) of 11 species of Ceratophyllidae, Hystrichopsyllidae and Leptopsyllidae families were tested for the presence of Rickettsia species and Coxiella burnetii with conventional and specific quantitative real-time PCR assays. Fleas were collected from five rodent hosts (Myodes glareolus, Apodemus flavicollis, Apodemus agrarius, Microtus subterraneus, Microtus arvalis) and three shrew species (Sorex araneus, Neomys fodiens, Crocidura suaveolens) captured in Eastern and Southern Slovakia. Overall, Rickettsia spp. was found in 10.8% (34/315) of the tested fleas of Ctenophthalmus agyrtes, Ctenophthalmus solutus, Ctenophthalmus uncinatus and Nosopsyllus fasciatus species. Infected fleas were coming from A. flavicollis, A. agrarius, and M. glareolus captured in Eastern Slovakia. C. burnetii was not found in any fleas. R. felis, Rickettsia helvetica, unidentified Rickettsia, and rickettsial endosymbionts were identified in fleas infesting small mammals in the Košice region, Eastern Slovakia. This study is the first report of R. felis infection in C. solutus male flea collected from A. agrarius in Slovakia.}, }
@article {pmid26338189, year = {2015}, author = {Fan, HW and Noda, H and Xie, HQ and Suetsugu, Y and Zhu, QH and Zhang, CX}, title = {Genomic Analysis of an Ascomycete Fungus from the Rice Planthopper Reveals How It Adapts to an Endosymbiotic Lifestyle.}, journal = {Genome biology and evolution}, volume = {7}, number = {9}, pages = {2623-2634}, pmid = {26338189}, issn = {1759-6653}, mesh = {Adaptation, Biological/genetics ; Animals ; Ascomycota/classification/*genetics ; *Evolution, Molecular ; Genes, Fungal ; *Genome, Fungal ; Genomics ; Hemiptera/*microbiology ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {A number of sap-sucking insects harbor endosymbionts, which are thought to play an important role in the development of their hosts. One of the most important rice pests, the brown planthopper (BPH), Nilaparvata lugens (Stål), harbors an obligatory yeast-like symbiont (YLS) that cannot be cultured in vitro. Genomic information on this YLS would be useful to better understand its evolution. In this study, we performed genome sequencing of the YLS using both 454 and Illumina approaches, generating a draft genome that shows a slightly smaller genome size and relatively higher GC content than most ascomycete fungi. A phylogenomic analysis of the YLS supported its close relationship with insect pathogens. We analyzed YLS-specific genes and the categories of genes that are likely to have changed in the YLS during its evolution. The loss of mating type locus demonstrated in the YLS sheds light on the evolution of eukaryotic symbionts. This information about the YLS genome provides a helpful guide for further understanding endosymbiotic associations in hemiptera and the symbiotic replacement of ancient bacteria with a multifunctional YLS seems to have been a successful change.}, }
@article {pmid26332792, year = {2015}, author = {Łukasik, P and Guo, H and van Asch, M and Henry, LM and Godfray, HC and Ferrari, J}, title = {Horizontal transfer of facultative endosymbionts is limited by host relatedness.}, journal = {Evolution; international journal of organic evolution}, volume = {69}, number = {10}, pages = {2757-2766}, doi = {10.1111/evo.12767}, pmid = {26332792}, issn = {1558-5646}, support = {BB/E010857/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/genetics/*microbiology/parasitology ; Enterobacteriaceae/genetics/physiology ; Fertility ; Fungi/pathogenicity ; Genotype ; Host-Pathogen Interactions ; Symbiosis ; Wasps ; }, abstract = {Heritable microbial symbionts can have important effects on many aspects of their hosts' biology. Acquisition of a novel symbiont strain can provide fitness benefits to the host, with significant ecological and evolutionary consequences. We measured barriers to horizontal transmission by artificially transferring facultative symbionts from the grain aphid, Sitobion avenae, and five other aphid species into two clonal genotypes of S. avenae. We found the symbiont Hamiltonella defensa establishes infections more easily following a transfer from the same host species and that such infections are more stable. Infection success was also higher when the introduced symbiont strain was more closely related to the strain that was originally present in the host (but which had previously been removed). There were no differences among successfully established symbiont strains in their effect on aphid fecundity. Hamiltonella defensa did not confer protection against parasitoids in our S. avenae clones, although it often does in other aphid hosts. However, strains of the symbiont Regiella insecticola originating from two host species protected grain aphids against the pathogenic fungus Pandora neoaphidis. This study helps describe the extent to which facultative symbionts can act as a pool of adaptations that can be sampled by their eukaryote hosts.}, }
@article {pmid26323764, year = {2015}, author = {Koonin, EV}, title = {Origin of eukaryotes from within archaea, archaeal eukaryome and bursts of gene gain: eukaryogenesis just made easier?.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {370}, number = {1678}, pages = {20140333}, pmid = {26323764}, issn = {1471-2970}, mesh = {Archaea/*genetics ; *Biological Evolution ; Eukaryota/genetics ; *Eukaryotic Cells ; *Genome, Archaeal ; }, abstract = {The origin of eukaryotes is a fundamental, forbidding evolutionary puzzle. Comparative genomic analysis clearly shows that the last eukaryotic common ancestor (LECA) possessed most of the signature complex features of modern eukaryotic cells, in particular the mitochondria, the endomembrane system including the nucleus, an advanced cytoskeleton and the ubiquitin network. Numerous duplications of ancestral genes, e.g. DNA polymerases, RNA polymerases and proteasome subunits, also can be traced back to the LECA. Thus, the LECA was not a primitive organism and its emergence must have resulted from extensive evolution towards cellular complexity. However, the scenario of eukaryogenesis, and in particular the relationship between endosymbiosis and the origin of eukaryotes, is far from being clear. Four recent developments provide new clues to the likely routes of eukaryogenesis. First, evolutionary reconstructions suggest complex ancestors for most of the major groups of archaea, with the subsequent evolution dominated by gene loss. Second, homologues of signature eukaryotic proteins, such as actin and tubulin that form the core of the cytoskeleton or the ubiquitin system, have been detected in diverse archaea. The discovery of this 'dispersed eukaryome' implies that the archaeal ancestor of eukaryotes was a complex cell that might have been capable of a primitive form of phagocytosis and thus conducive to endosymbiont capture. Third, phylogenomic analyses converge on the origin of most eukaryotic genes of archaeal descent from within the archaeal evolutionary tree, specifically, the TACK superphylum. Fourth, evidence has been presented that the origin of the major archaeal phyla involved massive acquisition of bacterial genes. Taken together, these findings make the symbiogenetic scenario for the origin of eukaryotes considerably more plausible and the origin of the organizational complexity of eukaryotic cells more readily explainable than they appeared until recently.}, }
@article {pmid26323759, year = {2015}, author = {Saw, JH and Spang, A and Zaremba-Niedzwiedzka, K and Juzokaite, L and Dodsworth, JA and Murugapiran, SK and Colman, DR and Takacs-Vesbach, C and Hedlund, BP and Guy, L and Ettema, TJ}, title = {Exploring microbial dark matter to resolve the deep archaeal ancestry of eukaryotes.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {370}, number = {1678}, pages = {20140328}, pmid = {26323759}, issn = {1471-2970}, support = {310039/ERC_/European Research Council/International ; }, mesh = {Archaea/classification/*genetics ; Eukaryotic Cells/*classification/*cytology ; Gene Expression Regulation, Archaeal/physiology ; Genetic Variation ; Genome, Archaeal ; Metagenomics/*methods ; *Phylogeny ; RNA, Archaeal/genetics/metabolism ; RNA, Ribosomal, 16S/genetics ; }, abstract = {The origin of eukaryotes represents an enigmatic puzzle, which is still lacking a number of essential pieces. Whereas it is currently accepted that the process of eukaryogenesis involved an interplay between a host cell and an alphaproteobacterial endosymbiont, we currently lack detailed information regarding the identity and nature of these players. A number of studies have provided increasing support for the emergence of the eukaryotic host cell from within the archaeal domain of life, displaying a specific affiliation with the archaeal TACK superphylum. Recent studies have shown that genomic exploration of yet-uncultivated archaea, the so-called archaeal 'dark matter', is able to provide unprecedented insights into the process of eukaryogenesis. Here, we provide an overview of state-of-the-art cultivation-independent approaches, and demonstrate how these methods were used to obtain draft genome sequences of several novel members of the TACK superphylum, including Lokiarchaeum, two representatives of the Miscellaneous Crenarchaeotal Group (Bathyarchaeota), and a Korarchaeum-related lineage. The maturation of cultivation-independent genomics approaches, as well as future developments in next-generation sequencing technologies, will revolutionize our current view of microbial evolution and diversity, and provide profound new insights into the early evolution of life, including the enigmatic origin of the eukaryotic cell.}, }
@article {pmid26323752, year = {2015}, author = {Williams, TA and Embley, TM}, title = {Changing ideas about eukaryotic origins.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {370}, number = {1678}, pages = {20140318}, pmid = {26323752}, issn = {1471-2970}, support = {268701/ERC_/European Research Council/International ; 045404//Wellcome Trust/United Kingdom ; }, mesh = {Archaea/*genetics ; Bacteria/*genetics ; *Biological Evolution ; Eukaryotic Cells/*cytology ; Genome ; }, abstract = {The origin of eukaryotic cells is one of the most fascinating challenges in biology, and has inspired decades of controversy and debate. Recent work has led to major upheavals in our understanding of eukaryotic origins and has catalysed new debates about the roles of endosymbiosis and gene flow across the tree of life. Improved methods of phylogenetic analysis support scenarios in which the host cell for the mitochondrial endosymbiont was a member of the Archaea, and new technologies for sampling the genomes of environmental prokaryotes have allowed investigators to home in on closer relatives of founding symbiotic partners. The inference and interpretation of phylogenetic trees from genomic data remains at the centre of many of these debates, and there is increasing recognition that trees built using inadequate methods can prove misleading, whether describing the relationship of eukaryotes to other cells or the root of the universal tree. New statistical approaches show promise for addressing these questions but they come with their own computational challenges. The papers in this theme issue discuss recent progress on the origin of eukaryotic cells and genomes, highlight some of the ongoing debates, and suggest possible routes to future progress.}, }
@article {pmid26314016, year = {2015}, author = {Alkhedir, H and Karlovsky, P and Mashaly, AM and Vidal, S}, title = {Phylogenetic Relationships of the Symbiotic Bacteria in the Aphid Sitobion avenae (Hemiptera: Aphididae).}, journal = {Environmental entomology}, volume = {44}, number = {5}, pages = {1358-1366}, doi = {10.1093/ee/nvv114}, pmid = {26314016}, issn = {1938-2936}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; Buchnera/*classification/genetics ; Enterobacteriaceae/*classification/genetics ; Germany ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Aphids have developed symbiotic associations with different bacterial species, and some morphological and molecular analyses have provided evidence of the host relationship between the primary symbiotic bacteria (Buchnera aphidicola) and the aphid while the contrary with the secondary symbiotic bacteria. In this study, we investigated the phylogenetic relationships of the bacterial endosymbionts in the aphid Sitobion avenae (F.). We characterized all bacterial endosymbionts in 10 genetically defined S. avenae clones by denaturing gradient gel electrophoresis and, from these clones, sequenced the 16S rRNA genes of both the primary endosymbiont, B. aphidicola (for the first time), and the secondary endosymbionts, Regiella insecticola and Hamiltonella defensa (for the first time). The phylogenetic analysis indicated that Buchnera from Sitobion related to those in Macrosiphoni. The analysis of the secondary endosymbionts indicated that there is no host relationship between H. defensa and R. insecticola from Sitobion and those from other aphid species. In this study, therefore, we identified further evidence for the relationship between Buchnera and its host and reported a relationship within the secondary endosymbionts of S. avenae from the same country, even though there were no relationships between the secondary bacteria and their host. We also discussed the diversity within the symbiotic bacteria in S. avenae clones.}, }
@article {pmid26313962, year = {2015}, author = {Wulff, JA and White, JA}, title = {The Endosymbiont Arsenophonus Provides a General Benefit to Soybean Aphid (Hemiptera: Aphididae) Regardless of Host Plant Resistance (Rag).}, journal = {Environmental entomology}, volume = {44}, number = {3}, pages = {574-581}, doi = {10.1093/ee/nvv031}, pmid = {26313962}, issn = {1938-2936}, mesh = {Animals ; Aphids/*genetics/*microbiology ; *Enterobacteriaceae ; Genotype ; Population Growth ; Soybeans/*genetics ; Symbiosis ; }, abstract = {Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), invokes substantial chemical treatment and economic cost in North America. Resistant soybean genotypes hold promise as a low-impact control methodology, but soybean aphid "biotypes" capable of development on resistant soy cast doubt on the durability of soy resistance. We hypothesized that variation in soybean aphid ability to colonize resistant soy is partially attributable to a bacterial symbiont of soybean aphid, Arsenophonus. We used microinjection to manipulate Arsenophonus infection in both virulent and avirulent aphid biotypes, resulting in five pairs of infected versus uninfected isolines. These isolines were subjected to various population growth rate assays on resistant Rag versus susceptible soybean. We found that aphid virulence on Rag soybean was not dependent on Arsenophonus: virulent aphid biotypes performed well on Rag soybean, and avirulent aphid biotypes performed poorly on Rag soybean, regardless of whether Arsenophonus was present or not. However, we did find that Arsenophonus-infected clones on average performed significantly better than their paired uninfected isolines. This pattern was not consistently evident on every date for every clone, either in the population assays nor when we compared lifetime fecundity of individual aphids in a separate experiment. Nevertheless, this overall benefit for infected aphids may be sufficient to explain the high frequency of Arsenophonus infection in soybean aphids.}, }
@article {pmid26313257, year = {2015}, author = {Ben Guerrero, E and Arneodo, J and Bombarda Campanha, R and Abrão de Oliveira, P and Veneziano Labate, MT and Regiani Cataldi, T and Campos, E and Cataldi, A and Labate, CA and Martins Rodrigues, C and Talia, P}, title = {Prospection and Evaluation of (Hemi) Cellulolytic Enzymes Using Untreated and Pretreated Biomasses in Two Argentinean Native Termites.}, journal = {PloS one}, volume = {10}, number = {8}, pages = {e0136573}, pmid = {26313257}, issn = {1932-6203}, mesh = {Acids/*chemistry ; Animals ; Argentina ; *Biomass ; Cellulases/chemistry/*metabolism ; Digestive System/enzymology/microbiology ; Insect Proteins/metabolism ; Isoptera/classification/*enzymology/microbiology ; Microscopy, Electron, Scanning ; Pennisetum/*enzymology/microbiology ; Polysaccharides/*metabolism ; Saccharum/*enzymology/microbiology ; Symbiosis ; }, abstract = {Saccharum officinarum bagasse (common name: sugarcane bagasse) and Pennisetum purpureum (also known as Napier grass) are among the most promising feedstocks for bioethanol production in Argentina and Brazil. In this study, both biomasses were assessed before and after acid pretreatment and following hydrolysis with Nasutitermes aquilinus and Cortaritermes fulviceps termite gut digestome. The chemical composition analysis of the biomasses after diluted acid pretreatment showed that the hemicellulose fraction was partially removed. The (hemi) cellulolytic activities were evaluated in bacterial culture supernatants of termite gut homogenates grown in treated and untreated biomasses. In all cases, we detected significantly higher endoglucanase and xylanase activities using pretreated biomasses compared to untreated biomasses, carboxymethylcellulose and xylan. Several protein bands with (hemi) cellulolytic activity were detected in zymograms and two-dimensional gel electrophoresis. Some proteins of these bands or spots were identified as xylanolytic peptides by mass spectrometry. Finally, the diversity of cultured cellulolytic bacterial endosymbionts associated to both Argentinean native termite species was analyzed. This study describes, for the first time, bacterial endosymbionts and endogenous (hemi) cellulases of two Argentinean native termites as well as their potential application in degradation of lignocellulosic biomass for bioethanol production.}, }
@article {pmid26307984, year = {2015}, author = {Chen, R and Wang, Z and Chen, J and Qiao, GX}, title = {Avoidance and Potential Remedy Solutions of Chimeras in Reconstructing the Phylogeny of Aphids Using the 16S rRNA Gene of Buchnera: A Case in Lachninae (Hemiptera).}, journal = {International journal of molecular sciences}, volume = {16}, number = {9}, pages = {20152-20167}, pmid = {26307984}, issn = {1422-0067}, mesh = {Animals ; Aphids/*classification/*genetics ; Chimera/*genetics ; *Phylogeny ; RNA, Ribosomal, 16S/*genetics ; }, abstract = {It is known that PCR amplification of highly homologous genes from complex DNA mixtures can generate a significant proportion of chimeric sequences. The 16S rRNA gene is not only widely used in estimating the species diversity of endosymbionts in aphids but also used to explore the co-diversification of aphids and their endosymbionts. Thus, chimeric sequences may lead to the discovery of non-existent endosymbiont species and mislead Buchnera-based phylogenetic analysis that lead to false conclusions. In this study, a high probability (6.49%) of chimeric sequence occurrence was found in the amplified 16S rRNA gene sequences of endosymbionts from aphid species in the subfamily Lachninae. These chimeras are hybrid products of multiple parent sequences from the dominant species of endosymbionts in each corresponding host. It is difficult to identify the chimeric sequences of a new or unidentified species due to the high variability of their main parent, Buchnera aphidicola, and because the chimeric sequences can confuse the phylogenetic analysis of 16S rRNA gene sequences. These chimeras present a challenge to Buchnera-based phylogenetic research in aphids. Thus, our study strongly suggests that using appropriate methods to detect chimeric 16S rRNA sequences may avoid some false conclusions in endosymbiont-based aphid research.}, }
@article {pmid26303516, year = {2015}, author = {Schulz, F and Tyml, T and Pizzetti, I and Dyková, I and Fazi, S and Kostka, M and Horn, M}, title = {Marine amoebae with cytoplasmic and perinuclear symbionts deeply branching in the Gammaproteobacteria.}, journal = {Scientific reports}, volume = {5}, number = {}, pages = {13381}, pmid = {26303516}, issn = {2045-2322}, support = {281633/ERC_/European Research Council/International ; }, mesh = {Amoeba/*classification/*microbiology ; Aquatic Organisms/classification/isolation &amp; purification/microbiology ; Cell Nucleus/*microbiology ; Cytoplasm/microbiology ; Gammaproteobacteria/*classification/isolation &amp; purification/*physiology ; Species Specificity ; Symbiosis/*physiology ; }, abstract = {Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named 'Candidatus Occultobacter vannellae' and 'Candidatus Nucleophilum amoebae'. While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria (85-88% 16S rRNA sequence similarity) but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host-derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts.}, }
@article {pmid26301521, year = {2015}, author = {Vale, PF and Jardine, MD}, title = {Sex-specific behavioural symptoms of viral gut infection and Wolbachia in Drosophila melanogaster.}, journal = {Journal of insect physiology}, volume = {82}, number = {}, pages = {28-32}, doi = {10.1016/j.jinsphys.2015.08.005}, pmid = {26301521}, issn = {1879-1611}, support = {095831//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Behavior, Animal ; Drosophila melanogaster/*microbiology/*virology ; Female ; Gastrointestinal Tract/virology ; Host-Pathogen Interactions ; Insect Viruses/*physiology ; Locomotion ; Male ; *Sex Factors ; Sleep ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {All organisms are infected with a range of symbionts spanning the spectrum of beneficial mutualists to detrimental parasites. The fruit fly Drosophila melanogaster is a good example, as both endosymbiotic Wolbachia, and pathogenic Drosophila C Virus (DCV) commonly infect it. While the pathophysiology and immune responses against both symbionts are the focus of intense study, the behavioural effects of these infections have received less attention. Here we report sex-specific behavioural responses to these infections in D. melanogaster. DCV infection caused increased sleep in female flies, but had no detectable effect in male flies. The presence of Wolbachia did not reduce this behavioural response to viral infection. We also found evidence for a sex-specific cost of Wolbachia, as male flies infected with the endosymbiont became more lethargic when awake. We discuss these behavioural symptoms as potentially adaptive sickness behaviours.}, }
@article {pmid26299539, year = {2016}, author = {Hadapad, AB and Prabhakar, CS and Chandekar, SC and Tripathi, J and Hire, RS}, title = {Diversity of bacterial communities in the midgut of Bactrocera cucurbitae (Diptera: Tephritidae) populations and their potential use as attractants.}, journal = {Pest management science}, volume = {72}, number = {6}, pages = {1222-1230}, doi = {10.1002/ps.4102}, pmid = {26299539}, issn = {1526-4998}, mesh = {Animals ; Bacillaceae/genetics/isolation &amp; purification ; Enterobacteriaceae/genetics/isolation &amp; purification ; Female ; *Gastrointestinal Microbiome ; Insect Control/methods ; Male ; Micrococcaceae/genetics/isolation &amp; purification ; Pheromones/*isolation &amp; purification ; Staphylococcaceae/genetics/isolation &amp; purification ; Tephritidae/*microbiology ; }, abstract = {BACKGROUND: The microbiota plays an important role in insect development and fitness. Understanding the gut microbiota composition is essential for the development of pest management strategies. Midgut bacteria were isolated from nine wild B. cucurbitae populations collected from different agroecological zones of India. These isolates were further studied for attractant potential of fruit fly adults, and the chemical constituents in the supernatants of gut bacteria were analysed.<br><br>RESULTS: Twenty-six bacterial isolates belonging to the families Enterobacteriaceae, Bacillaceae, Micrococcaceae and Staphylococcaceae were isolated and identified on the basis of 16S rRNA gene sequence analysis. The dominant species in the midgut of melon fly were from the genera Enterobacter (34.6%), Klebsiella (19.2%), Citrobacter (7.7%), Bacillus (15.4%) and Providencia (7.7%), and 3.8% each of Micrococcus, Staphylococcus, Leclercia and Exiguobacterium. Bactrocera cucurbitae and B. dorsalis adults were significantly attracted to bacterial whole cell cultures and their supernatants in the fruit fly attraction bioassays. Bacillus cereus, Enterobacter, Klebsiella, Citrobacter and Providencia species attracted both male and females of Bactrocera species. The supernatants of Klebsiella, Citrobacter and Providencia species attracted a significantly greater number of females than males. The most abundant chemical constituents in supernatants of K. oxytoca and C. freundii were 3-methyl-1-butanol, 2-phenylethanol, butyl isocyanatoacetate, 2-methyl-1-propanol and 3-hydroxy-2-butanone, as identified by gas chromatography-mass spectrometry.<br><br>CONCLUSIONS: The bacterial endosymbionts associated with melon fly exhibited attractant potential which could facilitate eco-friendly insect control strategies. &#xa9; 2015 Society of Chemical Industry.}, }
@article {pmid26291956, year = {2016}, author = {Bentlage, B and Rogers, TS and Bachvaroff, TR and Delwiche, CF}, title = {Complex Ancestries of Isoprenoid Synthesis in Dinoflagellates.}, journal = {The Journal of eukaryotic microbiology}, volume = {63}, number = {1}, pages = {123-137}, pmid = {26291956}, issn = {1550-7408}, support = {R01 ES021949/ES/NIEHS NIH HHS/United States ; }, mesh = {Dinoflagellida/*genetics/*metabolism ; Gene Expression Profiling ; Metabolic Networks and Pathways/*genetics ; Mevalonic Acid/metabolism ; Phylogeny ; Plastids ; Sterols/biosynthesis ; Terpenes/*metabolism ; }, abstract = {Isoprenoid metabolism occupies a central position in the anabolic metabolism of all living cells. In plastid-bearing organisms, two pathways may be present for de novo isoprenoid synthesis, the cytosolic mevalonate pathway (MVA) and nuclear-encoded, plastid-targeted nonmevalonate pathway (DOXP). Using transcriptomic data we find that dinoflagellates apparently make exclusive use of the DOXP pathway. Using phylogenetic analyses of all DOXP genes we inferred the evolutionary origins of DOXP genes in dinoflagellates. Plastid replacements led to a DOXP pathway of multiple evolutionary origins. Dinoflagellates commonly referred to as dinotoms due to their relatively recent acquisition of a diatom plastid, express two completely redundant DOXP pathways. Dinoflagellates with a tertiary plastid of haptophyte origin, by contrast, express a hybrid pathway of dual evolutionary origin. Here, changes in the targeting motif of signal/transit peptide likely allow for targeting the new plastid by the proteins of core isoprenoid metabolism proteins. Parasitic dinoflagellates of the Amoebophyra species complex appear to have lost the DOXP pathway, suggesting that they may rely on their host for sterol synthesis.}, }
@article {pmid26287997, year = {2015}, author = {Raina, HS and Singh, A and Popli, S and Pandey, N and Rajagopal, R}, title = {Infection of Bacterial Endosymbionts in Insects: A Comparative Study of Two Techniques viz PCR and FISH for Detection and Localization of Symbionts in Whitefly, Bemisia tabaci.}, journal = {PloS one}, volume = {10}, number = {8}, pages = {e0136159}, pmid = {26287997}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*genetics/*isolation &amp; purification ; DNA Probes/genetics ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Ribosomal/genetics/isolation &amp; purification ; Hemiptera/*microbiology/pathogenicity ; In Situ Hybridization, Fluorescence ; India ; Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {Bacterial endosymbionts have been associated with arthropods and large number of the insect species show interaction with such bacteria. Different approaches have been used to understand such symbiont- host interactions. The whitefly, Bemisia tabaci, a highly invasive agricultural pest, harbors as many as seven different bacterial endosymbionts. These bacterial endosymbionts are known to provide various nutritional, physiological, environmental and evolutionary benefits to its insect host. In this study, we have tried to compare two techniques, Polymerase chain reaction (PCR) and Flourescence in situ Hybridisation (FISH) commonly used for identification and localization of bacterial endosymbionts in B. tabaci as it harbors one of the highest numbers of endosymbionts which have helped it in becoming a successful global invasive agricultural pest. The amplified PCR products were observed as bands on agarose gel by electrophoresis while the FISH samples were mounted on slides and observed under confocal microscope. Analysis of results obtained by these two techniques revealed the advantages of FISH over PCR. On a short note, performing FISH, using LNA probes proved to be more sensitive and informative for identification as well as localization of bacterial endosymbionts in B. tabaci than relying on PCR. This study would help in designing more efficient experiments based on much reliable detection procedure and studying the role of endosymbionts in insects.}, }
@article {pmid26287231, year = {2015}, author = {Molloy, JC and Sinkins, SP}, title = {Wolbachia Do Not Induce Reactive Oxygen Species-Dependent Immune Pathway Activation in Aedes albopictus.}, journal = {Viruses}, volume = {7}, number = {8}, pages = {4624-4639}, pmid = {26287231}, issn = {1999-4915}, support = {095121//Wellcome Trust/United Kingdom ; BB/H016511/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Aedes/immunology/*microbiology ; Animals ; Arboviruses/immunology ; Cell Line ; Drosophila melanogaster/microbiology ; Female ; Gene Expression Profiling ; Immunity, Innate ; Reactive Oxygen Species/*metabolism ; Wolbachia/*immunology ; }, abstract = {Aedes albopictus is a major vector of dengue (DENV) and chikungunya (CHIKV) viruses, causing millions of infections annually. It naturally carries, at high frequency, the intracellular inherited bacterial endosymbiont Wolbachia strains wAlbA and wAlbB; transinfection with the higher-density Wolbachia strain wMel from Drosophila melanogaster led to transmission blocking of both arboviruses. The hypothesis that reactive oxygen species (ROS)-induced immune activation plays a role in arbovirus inhibition in this species was examined. In contrast to previous observations in Ae. aegypti, elevation of ROS levels was not observed in either cell lines or mosquito lines carrying the wild-type Wolbachia or higher-density Drosophila Wolbachia strains. There was also no upregulation of genes controlling innate immune pathways or with antioxidant/ROS-producing functions. These data suggest that ROS-mediated immune activation is not an important component of the viral transmission-blocking phenotype in this species.}, }
@article {pmid26286985, year = {2015}, author = {Allen, JF}, title = {Why chloroplasts and mitochondria retain their own genomes and genetic systems: Colocation for redox regulation of gene expression.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10231-10238}, pmid = {26286985}, issn = {1091-6490}, mesh = {Chloroplasts/genetics/*physiology ; Cytosol/metabolism ; DNA Replication ; DNA, Plant/genetics ; Electron Transport ; *Gene Expression Regulation, Plant ; Genome, Chloroplast ; Genome, Mitochondrial ; Mitochondria/genetics/*physiology ; *Oxidation-Reduction ; Oxidative Phosphorylation ; Photosynthesis/physiology ; Plants/genetics ; Transcription, Genetic ; }, abstract = {Chloroplasts and mitochondria are subcellular bioenergetic organelles with their own genomes and genetic systems. DNA replication and transmission to daughter organelles produces cytoplasmic inheritance of characters associated with primary events in photosynthesis and respiration. The prokaryotic ancestors of chloroplasts and mitochondria were endosymbionts whose genes became copied to the genomes of their cellular hosts. These copies gave rise to nuclear chromosomal genes that encode cytosolic proteins and precursor proteins that are synthesized in the cytosol for import into the organelle into which the endosymbiont evolved. What accounts for the retention of genes for the complete synthesis within chloroplasts and mitochondria of a tiny minority of their protein subunits? One hypothesis is that expression of genes for protein subunits of energy-transducing enzymes must respond to physical environmental change by means of a direct and unconditional regulatory control--control exerted by change in the redox state of the corresponding gene product. This hypothesis proposes that, to preserve function, an entire redox regulatory system has to be retained within its original membrane-bound compartment. Colocation of gene and gene product for redox regulation of gene expression (CoRR) is a hypothesis in agreement with the results of a variety of experiments designed to test it and which seem to have no other satisfactory explanation. Here, I review evidence relating to CoRR and discuss its development, conclusions, and implications. This overview also identifies predictions concerning the results of experiments that may yet prove the hypothesis to be incorrect.}, }
@article {pmid26286984, year = {2015}, author = {Campbell, MA and Van Leuven, JT and Meister, RC and Carey, KM and Simon, C and McCutcheon, JP}, title = {Genome expansion via lineage splitting and genome reduction in the cicada endosymbiont Hodgkinia.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10192-10199}, pmid = {26286984}, issn = {1091-6490}, support = {P20RR017670/RR/NCRR NIH HHS/United States ; }, mesh = {Alphaproteobacteria/*genetics ; Animals ; Evolution, Molecular ; Female ; *Genome, Bacterial ; Genome, Mitochondrial ; Genomics ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Open Reading Frames ; Organelles ; Phylogeny ; Plastids/genetics ; Ribosomes/metabolism ; Species Specificity ; *Symbiosis ; }, abstract = {Comparative genomics from mitochondria, plastids, and mutualistic endosymbiotic bacteria has shown that the stable establishment of a bacterium in a host cell results in genome reduction. Although many highly reduced genomes from endosymbiotic bacteria are stable in gene content and genome structure, organelle genomes are sometimes characterized by dramatic structural diversity. Previous results from Candidatus Hodgkinia cicadicola, an endosymbiont of cicadas, revealed that some lineages of this bacterium had split into two new cytologically distinct yet genetically interdependent species. It was hypothesized that the long life cycle of cicadas in part enabled this unusual lineage-splitting event. Here we test this hypothesis by investigating the structure of the Ca. Hodgkinia genome in one of the longest-lived cicadas, Magicicada tredecim. We show that the Ca. Hodgkinia genome from M. tredecim has fragmented into multiple new chromosomes or genomes, with at least some remaining partitioned into discrete cells. We also show that this lineage-splitting process has resulted in a complex of Ca. Hodgkinia genomes that are 1.1-Mb pairs in length when considered together, an almost 10-fold increase in size from the hypothetical single-genome ancestor. These results parallel some examples of genome fragmentation and expansion in organelles, although the mechanisms that give rise to these extreme genome instabilities are likely different.}, }
@article {pmid26286718, year = {2015}, author = {Czernic, P and Gully, D and Cartieaux, F and Moulin, L and Guefrachi, I and Patrel, D and Pierre, O and Fardoux, J and Chaintreuil, C and Nguyen, P and Gressent, F and Da Silva, C and Poulain, J and Wincker, P and Rofidal, V and Hem, S and Barrière, Q and Arrighi, JF and Mergaert, P and Giraud, E}, title = {Convergent Evolution of Endosymbiont Differentiation in Dalbergioid and Inverted Repeat-Lacking Clade Legumes Mediated by Nodule-Specific Cysteine-Rich Peptides.}, journal = {Plant physiology}, volume = {169}, number = {2}, pages = {1254-1265}, pmid = {26286718}, issn = {1532-2548}, mesh = {Amino Acid Sequence ; *Biological Evolution ; Bradyrhizobium/physiology ; Cysteine/chemistry ; Fabaceae/microbiology/*physiology ; Gene Expression Regulation, Plant ; Molecular Sequence Data ; Peptides/chemistry/metabolism ; Plant Proteins/chemistry/*metabolism ; Root Nodules, Plant/*microbiology/physiology ; Symbiosis/*physiology ; }, abstract = {Nutritional symbiotic interactions require the housing of large numbers of microbial symbionts, which produce essential compounds for the growth of the host. In the legume-rhizobium nitrogen-fixing symbiosis, thousands of rhizobium microsymbionts, called bacteroids, are confined intracellularly within highly specialized symbiotic host cells. In Inverted Repeat-Lacking Clade (IRLC) legumes such as Medicago spp., the bacteroids are kept under control by an arsenal of nodule-specific cysteine-rich (NCR) peptides, which induce the bacteria in an irreversible, strongly elongated, and polyploid state. Here, we show that in Aeschynomene spp. legumes belonging to the more ancient Dalbergioid lineage, bacteroids are elongated or spherical depending on the Aeschynomene spp. and that these bacteroids are terminally differentiated and polyploid, similar to bacteroids in IRLC legumes. Transcriptome, in situ hybridization, and proteome analyses demonstrated that the symbiotic cells in the Aeschynomene spp. nodules produce a large diversity of NCR-like peptides, which are transported to the bacteroids. Blocking NCR transport by RNA interference-mediated inactivation of the secretory pathway inhibits bacteroid differentiation. Together, our results support the view that bacteroid differentiation in the Dalbergioid clade, which likely evolved independently from the bacteroid differentiation in the IRLC clade, is based on very similar mechanisms used by IRLC legumes.}, }
@article {pmid26283348, year = {2015}, author = {Klose, J and Polz, MF and Wagner, M and Schimak, MP and Gollner, S and Bright, M}, title = {Endosymbionts escape dead hydrothermal vent tubeworms to enrich the free-living population.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {36}, pages = {11300-11305}, pmid = {26283348}, issn = {1091-6490}, mesh = {Animals ; Bacteria/genetics/*growth &amp; development/ultrastructure ; Bacterial Load ; Cell Death ; Environmental Microbiology ; Host-Pathogen Interactions ; Hydrothermal Vents/*parasitology ; In Situ Hybridization, Fluorescence ; Larva/microbiology ; Microscopy, Electron, Transmission ; Polychaeta/genetics/*microbiology/ultrastructure ; RNA, Ribosomal, 16S/genetics ; Seawater/microbiology ; *Symbiosis ; }, abstract = {Theory predicts that horizontal acquisition of symbionts by plants and animals must be coupled to release and limited dispersal of symbionts for intergenerational persistence of mutualisms. For deep-sea hydrothermal vent tubeworms (Vestimentifera, Siboglinidae), it has been demonstrated that a few symbiotic bacteria infect aposymbiotic host larvae and grow in a newly formed organ, the trophosome. However, whether viable symbionts can be released to augment environmental populations has been doubtful, because (i) the adult worms lack obvious openings and (ii) the vast majority of symbionts has been regarded as terminally differentiated. Here we show experimentally that symbionts rapidly escape their hosts upon death and recruit to surfaces where they proliferate. Estimating symbiont release from our experiments taken together with well-known tubeworm density ranges, we suggest a few million to 1.5 billion symbionts seeding the environment upon death of a tubeworm clump. In situ observations show that such clumps have rapid turnover, suggesting that release of large numbers of symbionts may ensure effective dispersal to new sites followed by active larval colonization. Moreover, release of symbionts might enable adaptations that evolve within host individuals to spread within host populations and possibly to new environments.}, }
@article {pmid26270964, year = {2015}, author = {Schmidt, C and Morard, R and Almogi-Labin, A and Weinmann, AE and Titelboim, D and Abramovich, S and Kucera, M}, title = {Recent Invasion of the Symbiont-Bearing Foraminifera Pararotalia into the Eastern Mediterranean Facilitated by the Ongoing Warming Trend.}, journal = {PloS one}, volume = {10}, number = {8}, pages = {e0132917}, pmid = {26270964}, issn = {1932-6203}, mesh = {Biodiversity ; *Climate Change ; *Ecosystem ; *Foraminifera/classification/genetics ; *Introduced Species ; Mediterranean Region ; Models, Theoretical ; Photochemistry ; Phylogeny ; Reproduction ; *Symbiosis ; Temperature ; }, abstract = {The eastern Mediterranean is a hotspot of biological invasions. Numerous species of Indo-pacific origin have colonized the Mediterranean in recent times, including tropical symbiont-bearing foraminifera. Among these is the species Pararotalia calcariformata. Unlike other invasive foraminifera, this species was discovered only two decades ago and is restricted to the eastern Mediterranean coast. Combining ecological, genetic and physiological observations, we attempt to explain the recent invasion of this species in the Mediterranean Sea. Using morphological and genetic data, we confirm the species attribution to P. calcariformata McCulloch 1977 and identify its symbionts as a consortium of diatom species dominated by Minutocellus polymorphus. We document photosynthetic activity of its endosymbionts using Pulse Amplitude Modulated Fluorometry and test the effects of elevated temperatures on growth rates of asexual offspring. The culturing of asexual offspring for 120 days shows a 30-day period of rapid growth followed by a period of slower growth. A subsequent 48-day temperature sensitivity experiment indicates a similar developmental pathway and high growth rate at 28°C, whereas an almost complete inhibition of growth was observed at 20°C and 35°C. This indicates that the offspring of this species may have lower tolerance to cold temperatures than what would be expected for species native to the Mediterranean. We expand this hypothesis by applying a Species Distribution Model (SDM) based on modern occurrences in the Mediterranean using three environmental variables: irradiance, turbidity and yearly minimum temperature. The model reproduces the observed restricted distribution and indicates that the range of the species will drastically expand westwards under future global change scenarios. We conclude that P. calcariformata established a population in the Levant because of the recent warming in the region. In line with observations from other groups of organisms, our results indicate that continued warming of the eastern Mediterranean will facilitate the invasion of more tropical marine taxa into the Mediterranean, disturbing local biodiversity and ecosystem structure.}, }
@article {pmid26269380, year = {2015}, author = {Duron, O}, title = {The IS1111 insertion sequence used for detection of Coxiella burnetii is widespread in Coxiella-like endosymbionts of ticks.}, journal = {FEMS microbiology letters}, volume = {362}, number = {17}, pages = {fnv132}, doi = {10.1093/femsle/fnv132}, pmid = {26269380}, issn = {1574-6968}, mesh = {Amino Acid Sequence ; Animals ; Argasidae/*microbiology ; Coxiella/*genetics ; Coxiella burnetii/*genetics/*isolation &amp; purification ; Coxiellaceae/genetics ; *DNA Transposable Elements ; DNA, Bacterial/isolation &amp; purification ; Genome, Bacterial ; Humans ; Ixodidae/*microbiology ; Q Fever/diagnosis/microbiology ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Coxiella is a genus of obligate intracellular bacteria engaged in a variety of interactions with eukaryotes. The type species, Coxiella burnetii, infects several vertebrate species, including humans, and is the causative agent of Q fever. Multiple copies of a specific transposable element, the insertion sequence IS1111, are present in the genome of C. burnetii and are routinely used for confirmation of Q fever cases. Recently, many Coxiella-like bacteria that are closely related but genetically distinct to C. burnetii have been found in ticks. These Coxiella-like bacteria are maternally inherited endosymbionts, present at high prevalence in tick populations and engaged in mutualistic interactions with their arthropod hosts. In this study, the presence of IS1111 was examined in the Coxiella-like endosymbionts and in bacteria of the Coxiella sister-genus, Rickettsiella. This screening reveals that a wide range of IS1111 copies were present in the Coxiella-like endosymbionts of ticks. DNA sequencing further identified genetically divergent IS1111 copies, including degraded copies that constitute an important genomic fossil record of past IS1111 expansions. These results show that IS1111 is not specific to C. burnetii, suggesting that Q fever detection assays based only on this element may lead to misidentification with Coxiella-like endosymbionts.}, }
@article {pmid26254486, year = {2015}, author = {Choi, JY and Bubnell, JE and Aquadro, CF}, title = {Population Genomics of Infectious and Integrated Wolbachia pipientis Genomes in Drosophila ananassae.}, journal = {Genome biology and evolution}, volume = {7}, number = {8}, pages = {2362-2382}, pmid = {26254486}, issn = {1759-6653}, support = {R01 GM095793/GM/NIGMS NIH HHS/United States ; R01GM095793/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila/*microbiology ; *Evolution, Molecular ; Female ; *Genetic Variation ; *Genome, Bacterial ; Genome, Mitochondrial ; Genomics ; Heterozygote ; Polymorphism, Genetic ; Sequence Alignment ; Wolbachia/*genetics ; }, abstract = {Coevolution between Drosophila and its endosymbiont Wolbachia pipientis has many intriguing aspects. For example, Drosophila ananassae hosts two forms of W. pipientis genomes: One being the infectious bacterial genome and the other integrated into the host nuclear genome. Here, we characterize the infectious and integrated genomes of W. pipientis infecting D. ananassae (wAna), by genome sequencing 15 strains of D. ananassae that have either the infectious or integrated wAna genomes. Results indicate evolutionarily stable maternal transmission for the infectious wAna genome suggesting a relatively long-term coevolution with its host. In contrast, the integrated wAna genome showed pseudogene-like characteristics accumulating many variants that are predicted to have deleterious effects if present in an infectious bacterial genome. Phylogenomic analysis of sequence variation together with genotyping by polymerase chain reaction of large structural variations indicated several wAna variants among the eight infectious wAna genomes. In contrast, only a single wAna variant was found among the seven integrated wAna genomes examined in lines from Africa, south Asia, and south Pacific islands suggesting that the integration occurred once from a single infectious wAna genome and then spread geographically. Further analysis revealed that for all D. ananassae we examined with the integrated wAna genomes, the majority of the integrated wAna genomic regions is represented in at least two copies suggesting a double integration or single integration followed by an integrated genome duplication. The possible evolutionary mechanism underlying the widespread geographical presence of the duplicate integration of the wAna genome is an intriguing question remaining to be answered.}, }
@article {pmid26250300, year = {2015}, author = {Mackie, AS and Oliver, PG and Nygren, A}, title = {Antonbruunia sociabilis sp. nov. (Annelida: Antonbruunidae) associated with the chemosynthetic deep-sea bivalve Thyasira scotiae Oliver &amp; Drewery, 2014, and a re-examination of the systematic affinities of Antonbruunidae.}, journal = {Zootaxa}, volume = {3995}, number = {}, pages = {20-36}, doi = {10.11646/zootaxa.3995.1.4}, pmid = {26250300}, issn = {1175-5334}, mesh = {Animal Distribution ; Animal Structures/anatomy &amp; histology/growth &amp; development ; Animals ; Annelida/anatomy &amp; histology/*classification/genetics/growth &amp; development ; Bivalvia/*parasitology ; Body Size ; Ecosystem ; Female ; Male ; Oceans and Seas ; Organ Size ; Phylogeny ; }, abstract = {Antonbruunia sociabilis sp. nov., an abundant endosymbiont of Thyasira scotiae from a putative sulphidic 'seep' in the Hatton-Rockall Basin (1187-1200 m), North-East Atlantic Ocean, is described. The new species is compared with A. viridis and A. gerdesi from the West Indian Ocean and South-East Pacific Ocean respectively. The three species can be distinguished using a suite of morphological characters, and are associated with geographically separated chemosynthetic bivalve molluscs from different families (Thyasiridae, Lucinidae, Vesicomyidae) living in sediments at different depths. New morphological features are recognized for Antonbruunia and a re-assessment of its systematic affinities indicates a close relationship with the Pilargidae. Previous suggestions of an affiliation with the Nautiliniellidae, recently incorporated into the Calamyzinae (Chrysopetalidae), were not supported. The apparent morphological similarities between the two groups are indicative of convergence related to their shared relationships with chemosynthetic bivalves. The first molecular analyses of Antonbruunia (16S and 18S rDNA) clearly indicate that a close relationship to Pilargidae (represented by Ancistrosyllis sp. and Sigambra sp.) is more likely than an affinity to Calamyzinae (represented by Calamyzas amphictenicola, Natushima sp., and Vigtorniella sp.).}, }
@article {pmid26246815, year = {2015}, author = {Niyyati, M and Mafi, M and Haghighi, A and Hakemi Vala, M}, title = {Occurrence of Potentially Pathogenic Bacterial-Endosymbionts in Acanthamoeba Spp.}, journal = {Iranian journal of parasitology}, volume = {10}, number = {2}, pages = {181-188}, pmid = {26246815}, issn = {1735-7020}, abstract = {BACKGROUND: Acanthamoeba- bacteria interactions enable pathogenic bacteria to tolerate harsh conditions and lead to transmission to the susceptible host. The present study was aimed to address the presence of bacterial endosymbionts of Acanthamoeba isolated from recreational water sources of Tehran, Iran. To the best of our knowledge this is the first study regarding occurrence of bacteria in environmental Acanthamoeba spp. in Iran.<br><br>METHODS: A total of 75 samples of recreational water sources were collected. Samples were cultured on non- nutrient agar 1.5% plates. Positive Acanthamoeba spp. were axenically grown. DNA extraction and PCR reaction was performed using JDP1-2 primers. All positive samples of Acanthamoeba were examined for the presence of endosymbionts using staining and molecular methods. The PCR products were then sequenced in order to determine the genotypes of Acanthamoeba and bacteria genera.<br><br>RESULTS: Out of 75 samples, 16 (21.3%) plates were positive for Acanthamoeba according to the morphological criteria. Molecular analysis revealed that Acanthamoeba belonged to T4 and T5 genotypes. Five isolates (35.7%) were positive for bacterial endosymbionts using staining method and PCR test. Sequencing of PCR products confirmed the presence of Pseudomonas aeruginosa and Agrobacterium tumefasiens.<br><br>CONCLUSION: The presence of Acanthamoeba bearing pathogenic endosymbionts in water sources leads us to public health issues including improved sanitation and decontamination measures in recreational water sources in order to prevent amoebae-related infection. To the best of our knowledge this is the first report regarding the isolation of A. tumefasiens from Acanthamoeba in Iran and worldwide.}, }
@article {pmid26224703, year = {2015}, author = {Burns, JA and Paasch, A and Narechania, A and Kim, E}, title = {Comparative Genomics of a Bacterivorous Green Alga Reveals Evolutionary Causalities and Consequences of Phago-Mixotrophic Mode of Nutrition.}, journal = {Genome biology and evolution}, volume = {7}, number = {11}, pages = {3047-3061}, pmid = {26224703}, issn = {1759-6653}, mesh = {Algal Proteins/*genetics ; *Biological Evolution ; Chlorophyta/*genetics/physiology ; Comparative Genomic Hybridization ; DNA, Algal/genetics ; Metabolic Networks and Pathways/*genetics ; Phagocytosis ; Photosynthesis/genetics ; Sequence Analysis, DNA ; }, abstract = {Cymbomonas tetramitiformis-a marine prasinophyte-is one of only a few green algae that still retain an ancestral particulate-feeding mechanism while harvesting energy through photosynthesis. The genome of the alga is estimated to be 850 Mb-1.2 Gb in size-the bulk of which is filled with repetitive sequences-and is annotated with 37,366 protein-coding gene models. A number of unusual metabolic pathways (for the Chloroplastida) are predicted for C. tetramitiformis, including pathways for Lipid-A and peptidoglycan metabolism. Comparative analyses of the predicted peptides of C. tetramitiformis to sets of other eukaryotes revealed that nonphagocytes are depleted in a number of genes, a proportion of which have known function in feeding. In addition, our analysis suggests that obligatory phagotrophy is associated with the loss of genes that function in biosynthesis of small molecules (e.g., amino acids). Further, C. tetramitiformis and at least one other phago-mixotrophic alga are thus unique, compared with obligatory heterotrophs and nonphagocytes, in that both feeding and small molecule synthesis-related genes are retained in their genomes. These results suggest that early, ancestral host eukaryotes that gave rise to phototrophs had the capacity to assimilate building block molecules from inorganic substances (i.e., prototrophy). The loss of biosynthesis genes, thus, may at least partially explain the apparent lack of instances of permanent incorporation of photosynthetic endosymbionts in later-divergent, auxotrophic eukaryotic lineages, such as metazoans and ciliates.}, }
@article {pmid26221957, year = {2015}, author = {Shao, MW and Lu, YH and Miao, S and Zhang, Y and Chen, TT and Zhang, YL}, title = {Diversity, Bacterial Symbionts and Antibacterial Potential of Gut-Associated Fungi Isolated from the Pantala flavescens Larvae in China.}, journal = {PloS one}, volume = {10}, number = {7}, pages = {e0134542}, pmid = {26221957}, issn = {1932-6203}, mesh = {Animals ; Antibiosis ; Biodiversity ; China ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Fungal/genetics/isolation &amp; purification ; Fungi/genetics/*isolation &amp; purification/*physiology ; Gastrointestinal Microbiome/genetics ; Larva/microbiology ; Odonata/*microbiology ; Phylogeny ; Symbiosis ; }, abstract = {The diversity of fungi associated with the gut of Pantala flavescens larvae was investigated using a culture-dependent method and molecular identification based on an analysis of the internally transcribed spacer sequence. In total, 48 fungal isolates were obtained from P. flavescens larvae. Based on phylogenetic analyses, the fungal isolates were grouped in 5 classes and 12 different genera. Fourteen bacterial 16S rDNA sequences derived from total genomic DNA extractions of fungal mycelia were obtained. The majority of the sequences were associated with Proteobacteria (13/14), and one Bacillaceae (1/14) was included. Leclercia sp., Oceanobacillus oncorhynchi and Methylobacterium extorquens, were reported for the first time as bacterial endosymbionts in fungi. High-performance liquid chromatography (HPLC) analysis indicated that bacterial symbionts produced specific metabolites and also exerted an inhibitory effect on fungal metabolites. The biological activity of the fungal culture extracts against the pathogenic bacteria Staphylococcus aureus (ATCC 6538), Bacillus subtilis (ATCC 6633) and Escherichia coli (ATCC 8739) was investigated, and 20 extracts (42%) exhibited antibacterial activity against at least one of the tested bacterial strains. This study is the first report on the diversity and antibacterial activity of symbiotic fungi residing in the gut of P. flavescens larvae, and the results show that these fungi are highly diverse and could be exploited as a potential source of bioactive compounds.}, }
@article {pmid26220839, year = {2015}, author = {Rajević, N and Kovačević, G and Kalafatić, M and Gould, SB and Martin, WF and Franjević, D}, title = {Algal endosymbionts in European Hydra strains reflect multiple origins of the zoochlorella symbiosis.}, journal = {Molecular phylogenetics and evolution}, volume = {93}, number = {}, pages = {55-62}, doi = {10.1016/j.ympev.2015.07.014}, pmid = {26220839}, issn = {1095-9513}, mesh = {Animals ; Cell Nucleus/genetics ; Chlorella/*genetics ; Chloroplasts/genetics ; DNA, Intergenic/genetics ; Hydra/*genetics ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Symbiotic associations are of broad significance in evolution and biodiversity. Green Hydra is a classic example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors endosymbiotic unicellular green algae, most commonly from the genus Chlorella. We reconstructed the phylogeny of cultured algal endosymbionts isolated and maintained in laboratory conditions for years from green Hydra strains collected from four different geographical sites within Croatia, one from Germany and one from Israel. Nuclear (18S rDNA, ITS region) and chloroplast markers (16S, rbcL) for maximum likelihood phylogenetic analyses were used. We focused on investigating the positions of these algal endosymbiotic strains within the chlorophyte lineage. Molecular analyses established that different genera and species of unicellular green algae are present as endosymbionts in green Hydra, showing that endosymbiotic algae growing within green Hydra sampled from four Croatian localities are not monophyletic. Our results indicate that the intracellular algal endosymbionts of green Hydra have become established several times independently in evolution.}, }
@article {pmid26219201, year = {2015}, author = {Hall, SA and Mack, K and Blackwell, A and Evans, KA}, title = {Identification and disruption of bacteria associated with sheep scab mites-novel means of control?.}, journal = {Experimental parasitology}, volume = {157}, number = {}, pages = {110-116}, doi = {10.1016/j.exppara.2015.07.007}, pmid = {26219201}, issn = {1090-2449}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacteria/classification/drug effects/*isolation &amp; purification ; DNA, Bacterial/isolation &amp; purification ; Feces/microbiology ; Female ; Gentamicins/pharmacology ; Male ; Mite Infestations/microbiology/prevention &amp; control/*veterinary ; Phylogeny ; Psoroptidae/*microbiology ; Sheep ; Sheep Diseases/microbiology/parasitology/*prevention &amp; control ; Symbiosis ; Tetracycline/pharmacology ; Wool/microbiology ; }, abstract = {Psoroptes ovis mites, which cause psoroptic mange (sheep scab), were investigated to identify potential bacterial targets for endosymbiont control of sheep scab. In addition, transmission of bacteria to the sheep skin was investigated through the characterisation of bacteria present in P. ovis faecal trails and on the fleece environment by internal transcribed spacer (ITS) sequencing. A diverse range of bacteria was identified in addition to a potential endosymbiont candidate, Comamonas sp, which was detected in P. ovis by both ITS PCR and endosymbiont-specific PCR. Disruption of these bacteria within P. ovis, through the use of antibiotics, was explored; with significant reduction in mean mite survival when administered antibiotic diets compared with controls (LR4 = 23.12, P < 0.001). The antibiotic treatments also significantly affected the bacterial density (CFU/mite) within P. ovis, indicating that mite survival may be linked to the bacterial communities that they harbour. Although antibiotics are not suitable for practical application, these results suggest disrupting bacteria associated with P. ovis should be further investigated for novel control.}, }
@article {pmid26219074, year = {2015}, author = {Baxter, L and Brain, RA and Hosmer, AJ and Nema, M and Müller, KM and Solomon, KR and Hanson, ML}, title = {Effects of atrazine on egg masses of the yellow-spotted salamander (Ambystoma maculatum) and its endosymbiotic alga (Oophila amblystomatis).}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {206}, number = {}, pages = {324-331}, doi = {10.1016/j.envpol.2015.07.017}, pmid = {26219074}, issn = {1873-6424}, mesh = {Ambystoma/*embryology ; Animals ; Atrazine/*toxicity ; Chlorophyta/*drug effects/physiology ; Herbicides/*toxicity ; Ovum/*drug effects/growth &amp; development ; Symbiosis/*drug effects ; Toxicity Tests ; }, abstract = {Embryonic growth of the yellow-spotted salamander (Ambystoma maculatum) is enhanced by the presence of the green alga Oophila amblystomatis, in the egg capsule. To further assess potential impacts of herbicides on this relationship, A. maculatum egg masses were exposed to atrazine (0-338 μg/L) until hatching (up to 66 days). Exposure to atrazine reduced PSII yield of the symbiotic algae in a concentration-dependent manner, but did not significantly affect visible algal growth or any metrics associated with salamander development. Algal cells were also cultured in the laboratory for toxicity testing. In the 96-h growth inhibition test (0-680 μg/L), ECx values were generally greater than those reported for standard algal test species. Complete recovery of growth rates occurred within 96-h of transferring cells to untreated media. Overall, development of A. maculatum embryos was not affected by exposure to atrazine at concentrations and durations exceeding those found in the environment.}, }
@article {pmid26218797, year = {2015}, author = {Chen, HK and Song, SN and Wang, LH and Mayfield, AB and Chen, YJ and Chen, WN and Chen, CS}, title = {A Compartmental Comparison of Major Lipid Species in a Coral-Symbiodinium Endosymbiosis: Evidence that the Coral Host Regulates Lipogenesis of Its Cytosolic Lipid Bodies.}, journal = {PloS one}, volume = {10}, number = {7}, pages = {e0132519}, pmid = {26218797}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*metabolism/*microbiology ; Dinoflagellida/*metabolism ; Lipid Metabolism/*physiology ; Symbiosis/*physiology ; }, abstract = {The lipid body (LB) formation in the host coral gastrodermal cell cytoplasm is a hallmark of the coral-Symbiodinium endosymbiosis, and such lipid-based entities are not found in endosymbiont-free cnidarian cells. Therefore, the elucidation of lipogenesis regulation in LBs and how it is related to the lipid metabolism of the host and endosymbiont could provide direct insight to understand the symbiosis mechanism. Herein, the lipid composition of host cells of the stony coral Euphyllia glabrescens, as well as that of their cytoplasmic LBs and in hospite Symbiodinium populations, was examined by high performance liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS), and six major lipid species were identified: wax esters, sterol esters, triacylglycerols, cholesterols, free fatty acids, and phospholipids. Their concentrations differed significantly between host coral cells, LBs, and Symbiodinium, suggesting compartmental regulation. WE were only present in the host coral and were particularly highly concentrated in LBs. Amongst the four species of WE, the monoene R = C18:1/R = C16 was found to be LB-specific and was not present in the host gastrodermal cell cytoplasm. Furthermore, the acyl pool profiles of the individual LB lipid species were more similar, but not equal to, those of the host gastrodermal cells in which they were located, indicating partially autonomous lipid metabolism in these LBs. Nevertheless, given the overall similarity in the host gastrodermal cell and LB lipid profiles, these data suggest that a significant portion of the LB lipids may be of host coral origin. Finally, lipid profiles of the in hospite Symbiodinium populations were significantly distinct from those of the cultured Symbiodinium, potentially suggesting a host regulation effect that may be fundamental to lipid metabolism in endosymbiotic associations involving clade C Symbiodinium.}, }
@article {pmid26211618, year = {2015}, author = {Wan, G and Jiang, S and Wang, W and Li, G and Tao, X and Pan, W and Sword, GA and Chen, F}, title = {Rice stripe virus counters reduced fecundity in its insect vector by modifying insect physiology, primary endosymbionts and feeding behavior.}, journal = {Scientific reports}, volume = {5}, number = {}, pages = {12527}, pmid = {26211618}, issn = {2045-2322}, mesh = {Adaptation, Physiological/physiology ; Animals ; Feeding Behavior/*physiology ; Fertility/*physiology ; Hemiptera/*physiology/*virology ; Insect Vectors/*physiology/*virology ; Tenuivirus/*physiology ; }, abstract = {Virus-vector relationships can be complex and diverse as a result of long-term coevolution. Understanding these interactions is crucial for disease and vector management. Rice stripe virus (RSV) is known to be transovarially transmitted within its vector, Laodelphax striatellus, and causes serious rice stripe disease. In RSV-infected L. striatellus, we found contrasting changes in vector fecundity, physiology, primary endosymbionts (i.e. yeast-like symbionts, YLS) and feeding behavior that can interact to affect the spread of RSV. RSV-infected L. striatellus exhibited a significant decrease in fecundity that could lead a reduction of viruliferous individuals in populations. As a potential response to this loss, RSV infection also significantly shortened nymphal stage duration, which can strengthen RSV vertical circulation in L. striatellus populations and promote RSV spreading by adult migration and dispersal. Down-regulated JHAMT and up-regulated CYP307A1 in the juvenile hormone and ecdysteroid pathways, respectively, were linked to accelerated development. RSV-infected adults were also found to have higher body weight in conjunction with increased YLS abundance. Furthermore, prolonged host plant phloem exposure to salivation by RSV-infected adults should further enhance RSV horizontal transmission. Our study highlights potential strategies of RSV in enhancing its transmission, and provides new insights into the complexity of virus-vector interactions.}, }
@article {pmid26206894, year = {2015}, author = {Krawczyk, K and Szymańczyk, M and Obrępalska-Stęplowska, A}, title = {Prevalence of Endosymbionts in Polish Populations of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).}, journal = {Journal of insect science (Online)}, volume = {15}, number = {1}, pages = {}, pmid = {26206894}, issn = {1536-2442}, mesh = {Agriculture ; Animals ; Coleoptera/*microbiology ; DNA, Bacterial/genetics/metabolism ; Flavobacterium/genetics/metabolism/*physiology ; Molecular Sequence Data ; Phylogeny ; Poland ; RNA, Ribosomal, 23S/genetics/metabolism ; Sequence Analysis, DNA ; Solanum tuberosum/growth &amp; development ; *Symbiosis ; }, abstract = {Colorado potato beetle (CPB, Leptinotarsa decemlineata Say) (Coleoptera: Chrysomelidae) is one of the most serious insect pest feeding on wild and cultivated Solanaceae plants. This pest poses a significant threat to potato crops. CPB originated from North America but has become widespread and has adapted in new localizations. Currently, it is reported in many countries worldwide. Endosymbiotic bacteria might have an influence on insect adaptation to new conditions. They are known to play a role in invasiveness of insect hosts and to facilitate colonization of new niches; however, information on endosymbionts of the CPB is very limited. In this study, we screened CPB populations collected from 20 evenly distributed locations in Poland for the presence of Arsenophonus, Cardinium, Wolbachia, and Flavobacterium. We found the presence of Flavobacterium in the studied insects. Little is known about CPB-endosymbionts interactions, thus this study may provide a reference for future studies in this subject.}, }
@article {pmid26206380, year = {2015}, author = {Heyworth, ER and Ferrari, J}, title = {A facultative endosymbiont in aphids can provide diverse ecological benefits.}, journal = {Journal of evolutionary biology}, volume = {28}, number = {10}, pages = {1753-1760}, pmid = {26206380}, issn = {1420-9101}, support = {BB/F016751/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/J00524X/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/*physiology ; *Ecology ; *Symbiosis ; }, abstract = {Ecologically important traits of insects are often affected by facultative bacterial endosymbionts. This is best studied in the pea aphid Acyrthosiphon pisum, which is frequently infected by one or more of eight facultative symbiont species. Many of these symbiont species have been shown to provide one ecological benefit, but we have little understanding of the range of effects that a single strain can have. Here, we describe the phenotypes conferred by three strains of the recently discovered bacterium known as X-type (Enterobacteriaceae), each in their original aphid genotype which also carries a Spiroplasma symbiont. All comparisons are made between aphids that are coinfected with Spiroplasma and X-type and aphids of the same genotype that harbour only Spiroplasma. We show that in all cases, infection with X-type protects aphids from the lethal fungal pathogen Pandora neoaphidis, and in two cases, resistance to the parasitoid Aphidius ervi also increases. X-type can additionally affect aphid stress responses--the presence of X-type increased reproduction after the aphids were heat-stressed. Two of the three strains of X-type are able to provide all of these benefits. Under benign conditions, the aphids tended to suffer from reduced fecundity when harbouring X-type, a mechanism that might maintain intermediate frequencies in field populations. These findings highlight that a single strain of a facultative endosymbiont has the potential to provide diverse benefits to its aphid host.}, }
@article {pmid26201437, year = {2015}, author = {Kehr, JC and Dittmann, E}, title = {Protective tunicate endosymbiont with extreme genome reduction.}, journal = {Environmental microbiology}, volume = {17}, number = {10}, pages = {3430-3432}, doi = {10.1111/1462-2920.12941}, pmid = {26201437}, issn = {1462-2920}, }
@article {pmid26189661, year = {2015}, author = {Ramírez-Puebla, ST and Servín-Garcidueñas, LE and Ormeño-Orrillo, E and Vera-Ponce de León, A and Rosenblueth, M and Delaye, L and Martínez, J and Martínez-Romero, E}, title = {Species in Wolbachia? Proposal for the designation of 'Candidatus Wolbachia bourtzisii', 'Candidatus Wolbachia onchocercicola', 'Candidatus Wolbachia blaxteri', 'Candidatus Wolbachia brugii', 'Candidatus Wolbachia taylori', 'Candidatus Wolbachia collembolicola' and 'Candidatus Wolbachia multihospitum' for the different species within Wolbachia supergroups.}, journal = {Systematic and applied microbiology}, volume = {38}, number = {6}, pages = {390-399}, doi = {10.1016/j.syapm.2015.05.005}, pmid = {26189661}, issn = {1618-0984}, mesh = {Animals ; Arthropods/microbiology ; Base Composition ; Computational Biology/*methods ; DNA, Bacterial/chemistry/*genetics ; *Genome, Bacterial ; Molecular Sequence Data ; Nematoda/microbiology ; Nucleic Acid Hybridization ; *Sequence Analysis, DNA ; Wolbachia/*classification/*genetics ; }, abstract = {Wolbachia are highly extended bacterial endosymbionts that infect arthropods and filarial nematodes and produce contrasting phenotypes on their hosts. Wolbachia taxonomy has been understudied. Currently, Wolbachia strains are classified into phylogenetic supergroups. Here we applied phylogenomic analyses to study Wolbachia evolutionary relationships and examined metrics derived from their genome sequences such as average nucleotide identity (ANI), in silico DNA-DNA hybridization (DDH), G+C content, and synteny to shed light on the taxonomy of these bacteria. Draft genome sequences of strains wDacA and wDacB obtained from the carmine cochineal insect Dactylopius coccus were included. Although all analyses indicated that each Wolbachia supergroup represents a distinct evolutionary lineage, we found that some of the analyzed supergroups showed enough internal heterogeneity to be considered as assemblages of more than one species. Thus, supergroups would represent supraspecific groupings. Consequently, Wolbachia pipientis nomen species would apply only to strains of supergroup B and we propose the designation of 'Candidatus Wolbachia bourtzisii', 'Candidatus Wolbachia onchocercicola', 'Candidatus Wolbachia blaxterii', 'Candidatus Wolbachia brugii', 'Candidatus Wolbachia taylorii', 'Candidatus Wolbachia collembolicola' and 'Candidatus Wolbachia multihospitis' for other supergroups.}, }
@article {pmid26184928, year = {2015}, author = {Zheng, H and Brune, A}, title = {Complete Genome Sequence of Endomicrobium proavitum, a Free-Living Relative of the Intracellular Symbionts of Termite Gut Flagellates (Phylum Elusimicrobia).}, journal = {Genome announcements}, volume = {3}, number = {4}, pages = {}, pmid = {26184928}, issn = {2169-8287}, abstract = {We sequenced the complete genome of Endomicrobium proavitum strain Rsa215, the first isolate of the class Endomicrobia (phylum Elusimicrobia). It is the closest free-living relative of the endosymbionts of termite gut flagellates and thereby provides an excellent model for studying the evolutionary processes during the establishment of an intracellular symbiosis.}, }
@article {pmid26177568, year = {2015}, author = {Stefano, GB and Kream, RM}, title = {Nitric Oxide Regulation of Mitochondrial Processes: Commonality in Medical Disorders.}, journal = {Annals of transplantation}, volume = {20}, number = {}, pages = {402-407}, doi = {10.12659/AOT.894289}, pmid = {26177568}, issn = {2329-0358}, mesh = {Electron Transport/physiology ; Humans ; Mitochondria/*metabolism ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase/*metabolism ; Oxidation-Reduction ; Reactive Oxygen Species/*metabolism ; }, abstract = {The vital status of diverse classes of eukaryotic mitochondria is reflected by the high degree of evolutionary modification functionally linked to ongoing multifaceted organelle development. From this teleological perspective, a logistical enhancement of eukaryotic cellular energy requirements indicates a convergence of metabolic processes within the mitochondrial matrix for optimal synthesis of ATP from ADP and inorganic phosphate and necessitates an evolutionarily driven retrofit of the primordial endosymbiont bacterial plasma membrane into the inner mitochondrial membrane. The biochemical complexity of eukaryotic inner membrane electron transport complexes linked to temporally-defined, state-dependent, fluctuations in mitochondrial oxygen utilization is capable of generating deleterious reactive oxygen species. Within this functional context, an extensive neurochemical literature supports the role of the free radical gas nitric oxide (NO) as a key signaling molecule involved in the regulation of multiple aspects of mitochondrial respiration/oxidative phosphorylation. Importantly, the unique chemical properties of NO underlie its rapid metabolism in vivo within a mechanistic spectrum of small oxidative molecules, free and protein-bound thiol adducts, and reversible binding to ferrous heme iron centers. Recent compelling work has identified a medically relevant dual regulation pathway for mitochondrial NO expression mediated by traditionally characterized NO synthases (NOS) and by enzymatic reduction of available cellular nitrite pools by a diverse class of cytosolic and mitochondrial nitrite reductases. Accordingly, our short review presents selected medically-based discussion topics relating to multi-faceted NO regulation of mitochondrial functions in human health and disease states.}, }
@article {pmid26174827, year = {2015}, author = {Le, TA and Vi, TT and Nguyen, KL and Le, TH}, title = {A Rare Human Case of Dirofilaria repens Infection in the Subcutaneous Posterior Thorax with Molecular Identification.}, journal = {The Korean journal of parasitology}, volume = {53}, number = {3}, pages = {329-333}, pmid = {26174827}, issn = {1738-0006}, mesh = {Adult ; Animals ; Dirofilaria repens/classification/genetics/*isolation &amp; purification/physiology ; Dirofilariasis/diagnosis/*parasitology ; Female ; Humans ; Phylogeny ; Thorax/*parasitology ; }, abstract = {The emergence of Dirofilarial infections in Asia including Vietnam is a clinically significant threat to the community. We here report a rare case of subcutaneous Dirofilaria repens infection on the posterior thoracic wall in a young woman presenting a painful, itchy, and palpable nodule. The adult worm was identified by mitochondrial cox1 and nuclear ITS-2 sequence determination. The diagnosis was additionally confirmed by 16S rRNA sequencing of the endosymbiont Wolbachia pipientis commonly co-existing with D. repens. This is a rare case of subcutaneous human infection on the posterior thoracic region caused by D. repens.}, }
@article {pmid26172209, year = {2016}, author = {Klein, A and Schrader, L and Gil, R and Manzano-Marín, A and Flórez, L and Wheeler, D and Werren, JH and Latorre, A and Heinze, J and Kaltenpoth, M and Moya, A and Oettler, J}, title = {A novel intracellular mutualistic bacterium in the invasive ant Cardiocondyla obscurior.}, journal = {The ISME journal}, volume = {10}, number = {2}, pages = {376-388}, pmid = {26172209}, issn = {1751-7370}, mesh = {Animals ; Ants/metabolism/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification/metabolism ; Female ; Male ; Phenylpyruvic Acids/metabolism ; Phylogeny ; *Symbiosis ; }, abstract = {The evolution of eukaryotic organisms is often strongly influenced by microbial symbionts that confer novel traits to their hosts. Here we describe the intracellular Enterobacteriaceae symbiont of the invasive ant Cardiocondyla obscurior, 'Candidatus Westeberhardia cardiocondylae'. Upon metamorphosis, Westeberhardia is found in gut-associated bacteriomes that deteriorate following eclosion. Only queens maintain Westeberhardia in the ovarian nurse cells from where the symbionts are transmitted to late-stage oocytes during nurse cell depletion. Functional analyses of the streamlined genome of Westeberhardia (533 kb, 23.41% GC content) indicate that neither vitamins nor essential amino acids are provided for the host. However, the genome encodes for an almost complete shikimate pathway leading to 4-hydroxyphenylpyruvate, which could be converted into tyrosine by the host. Taken together with increasing titers of Westeberhardia during pupal stage, this suggests a contribution of Westeberhardia to cuticle formation. Despite a widespread occurrence of Westeberhardia across host populations, one ant lineage was found to be naturally symbiont-free, pointing to the loss of an otherwise prevalent endosymbiont. This study yields insights into a novel intracellular mutualist that could play a role in the invasive success of C. obscurior.}, }
@article {pmid26172158, year = {2015}, author = {Webster, CL and Waldron, FM and Robertson, S and Crowson, D and Ferrari, G and Quintana, JF and Brouqui, JM and Bayne, EH and Longdon, B and Buck, AH and Lazzaro, BP and Akorli, J and Haddrill, PR and Obbard, DJ}, title = {The Discovery, Distribution, and Evolution of Viruses Associated with Drosophila melanogaster.}, journal = {PLoS biology}, volume = {13}, number = {7}, pages = {e1002210}, pmid = {26172158}, issn = {1545-7885}, support = {/WT_/Wellcome Trust/United Kingdom ; 095831/WT_/Wellcome Trust/United Kingdom ; WT085064/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; *Biological Evolution ; Conserved Sequence ; Drosophila melanogaster/*virology ; Drosophila simulans/virology ; Female ; Male ; Metagenomics ; Molecular Sequence Data ; RNA/analysis ; RNA Interference ; Viral Proteins/chemistry ; Wolbachia/isolation &amp; purification ; }, abstract = {Drosophila melanogaster is a valuable invertebrate model for viral infection and antiviral immunity, and is a focus for studies of insect-virus coevolution. Here we use a metagenomic approach to identify more than 20 previously undetected RNA viruses and a DNA virus associated with wild D. melanogaster. These viruses not only include distant relatives of known insect pathogens but also novel groups of insect-infecting viruses. By sequencing virus-derived small RNAs, we show that the viruses represent active infections of Drosophila. We find that the RNA viruses differ in the number and properties of their small RNAs, and we detect both siRNAs and a novel miRNA from the DNA virus. Analysis of small RNAs also allows us to identify putative viral sequences that lack detectable sequence similarity to known viruses. By surveying >2,000 individually collected wild adult Drosophila we show that more than 30% of D. melanogaster carry a detectable virus, and more than 6% carry multiple viruses. However, despite a high prevalence of the Wolbachia endosymbiont--which is known to be protective against virus infections in Drosophila--we were unable to detect any relationship between the presence of Wolbachia and the presence of any virus. Using publicly available RNA-seq datasets, we show that the community of viruses in Drosophila laboratories is very different from that seen in the wild, but that some of the newly discovered viruses are nevertheless widespread in laboratory lines and are ubiquitous in cell culture. By sequencing viruses from individual wild-collected flies we show that some viruses are shared between D. melanogaster and D. simulans. Our results provide an essential evolutionary and ecological context for host-virus interaction in Drosophila, and the newly reported viral sequences will help develop D. melanogaster further as a model for molecular and evolutionary virus research.}, }
@article {pmid26161659, year = {2015}, author = {Overholt, WA and Diaz, R and Rosskopf, E and Green, SJ and Overholt, WA}, title = {Deep Characterization of the Microbiomes of Calophya spp. (Hemiptera: Calophyidae) Gall-Inducing Psyllids Reveals the Absence of Plant Pathogenic Bacteria and Three Dominant Endosymbionts.}, journal = {PloS one}, volume = {10}, number = {7}, pages = {e0132248}, pmid = {26161659}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*genetics ; Biodiversity ; Florida ; Hemiptera/*microbiology ; High-Throughput Nucleotide Sequencing/*methods ; Microbiota/*genetics ; Phylogeny ; Plant Tumors/*microbiology ; Symbiosis/*genetics ; }, abstract = {Bacteria associated with sap-feeding insect herbivores include not only symbionts that may increase their hosts' fitness but also harmful plant pathogens. Calophya spp. gall-inducing psyllids (Hemiptera: Calophyidae) are being investigated for their potential as biological control agents of the noxious weed, Brazilian peppertree (Schinus terebinthifolia), in Florida. Although there are no examples of plant pathogen transmission by members of the family Calophyidae, several insects in the superfamily Psylloidea are known to transmit pathogenic bacteria in the genera Candidatus Liberibacter and Candidatus Phytoplasma. To determine whether Calophya spp. harbor potentially harmful plant pathogenic bacteria, we sequenced small subunit (SSU) ribosomal RNA (rRNA) gene amplicons generated from individuals from four Calophya spp. populations: All microbial SSU gene sequences fell into the bacterial domain, with 98-99% belonging to the Proteobacteria. The Calophya microbiomes contained a relatively simple community, with 49-79 operational taxonomic units (OTUs; 97%) detected, and only 5-8 OTUs with greater than 1% abundance. Candidatus Carsonella showed the highest relative abundance, with OTUs from this candidate genus representing between 51-65% of all recovered sequences. The next most abundant clade observed was an unclassified Enterobacteriacae group closely related to bacteria from the genera Buchnera and Blochmannia that ranged from 20-31% in relative abundance. Wolbachia populations were the third most abundant group and represented 7-27% of the diversity in microbial OTUs. No SSU rRNA gene sequences from putative pathogenic bacteria from the genera Ca. Liberibacter or Ca. Phytoplasma were detected in the microbiomes of the four Calophya populations. The probability that infected psyllids were present in our colonies, but were not sampled, was extremley low (1.39 x 10(-10)). As far as we are aware, our study is the first to characterize the microbiome of a candidate biological control agent, and coupled with previous work demonstrating a high degree of host specificity and absence of plant viruses, suggests that releasing Calophya spp. in United States poses minimal risk to non-target plants.}, }
@article {pmid26161080, year = {2015}, author = {López-Madrigal, S and Latorre, A and Moya, A and Gil, R}, title = {The link between independent acquisition of intracellular gamma-endosymbionts and concerted evolution in Tremblaya princeps.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {642}, pmid = {26161080}, issn = {1664-302X}, abstract = {Many insect species establish mutualistic symbiosis with intracellular bacteria that complement their unbalanced diets. The betaproteobacterium "Candidatus Tremblaya" maintains an ancient symbiosis with mealybugs (Hemiptera: Pseudococcidae), which are classified in subfamilies Phenacoccinae and Pseudococcinae. Most Phenacoccinae mealybugs have "Candidatus Tremblaya phenacola" as their unique endosymbiont, while most Pseudococcinae mealybugs show a nested symbiosis (a bacterial symbiont placed inside another one) where every "Candidatus Tremblaya princeps" cell harbors several cells of a gammaproteobacterium. Genomic characterization of the endosymbiotic consortium from Planococcus citri, composed by "Ca. Tremblaya princeps" and "Candidatus Moranella endobia," unveiled several atypical features of the former's genome, including the concerted evolution of paralogous loci. Its comparison with the genome of "Ca. Tremblaya phenacola" PAVE, single endosymbiont of Phenacoccus avenae, suggests that the atypical reductive evolution of "Ca. Tremblaya princeps" could be linked to the acquisition of "Ca. Moranella endobia," which possess an almost complete set of genes encoding proteins involved in homologous recombination. In order to test this hypothesis, we performed comparative genomics between "Ca. Tremblaya phenacola" and "Ca. Tremblaya princeps" and searched for the co-occurrence of concerted evolution and homologous recombination genes in endosymbiotic consortia from four unexplored mealybug species, Dysmicoccus boninsis, Planococcus ficus, Pseudococcus longispinus, and Pseudococcus viburni. Our results support a link between concerted evolution and nested endosymbiosis.}, }
@article {pmid26160679, year = {2015}, author = {Greiman, SE and Tkach, M and Vaughan, JA and Tkach, VV}, title = {Laboratory maintenance of the bacterial endosymbiont, Neorickettsia sp., through the life cycle of a digenean, Plagiorchis elegans.}, journal = {Experimental parasitology}, volume = {157}, number = {}, pages = {78-83}, pmid = {26160679}, issn = {1090-2449}, support = {R15 AI092622/AI/NIAID NIH HHS/United States ; R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cricetinae ; Culex/*parasitology ; Insect Vectors/parasitology ; Life Cycle Stages ; Lymnaea/*parasitology ; Mesocricetus/*parasitology ; Mice ; Models, Biological ; Neorickettsia/*physiology ; Rodent Diseases/parasitology/transmission ; *Symbiosis ; Trematoda/growth &amp; development/*microbiology ; Trematode Infections/parasitology/transmission/veterinary ; }, abstract = {The Digenea (Platyhelminthes: Trematoda) are a diverse and complex group of internal metazoan parasites. These parasites can serve as hosts to obligate intracellular bacteria belonging to the genus Neorickettsia (Family: Anaplasmataceae). Neorickettsiae persist within all stages of the fluke life cycle and thus are maintained through vertical transmission. However, the low prevalence of Neorickettsia in nature limits study of their transmission biology at different steps of digenean life cycles. To resolve this dilemma, we have developed for the first time a laboratory model allowing to maintain Neorickettsia sp. through the whole life cycle of a digenean, Plagiorchis elegans. The laboratory life cycle of P. elegans consists of a snail first intermediate host, Lymnaea stagnalis, an aquatic arthropod second intermediate host, Culex pipiens (mosquito larva), and a vertebrate definitive host, Mesocricetus auratus (Syrian hamster). This paper focuses on the development of the laboratory life cycle, as well as outlines its potential uses in studying the transmission biology of Neorickettsia and its evolutionary relationship within its digenean host.}, }
@article {pmid26160214, year = {2016}, author = {Pawlikowska-Warych, M and Deptuła, W}, title = {Characteristics of chlamydia-like organisms pathogenic to fish.}, journal = {Journal of applied genetics}, volume = {57}, number = {1}, pages = {135-141}, pmid = {26160214}, issn = {2190-3883}, mesh = {Animals ; Chlamydiales/*classification/*pathogenicity ; Fish Diseases/*microbiology ; Fishes/*microbiology ; *Phylogeny ; }, abstract = {Bacteria from the Chlamydiales order have been long known, especially as pathogenic bacteria to humans and many animal species, principally including birds and mammals. But for slightly over 20 years, they have been identified in the aquatic environment as endosymbionts of amoebas and sea worms. For several years, they have also been recorded as a cause of diseases among fish, causing respiratory system infections in the form of epitheliocystis of the gill. At present, 11 chlamydia-like organisms pathogenic to fish have been described, including nine new ones, classified into six families, four of which are already known (Parachlamydiaceae, Rhabdochlamydiaceae, Candidatus Parilichlamydiaceae, Candidatus Clavichlamydiaceae) and two newly created families, namely Candidatus Actinochlamydiaceae and Candidatus Parilichlamydiaceae. This paper characterises 11 chlamydia-like organisms, as well as seven isolates not classified into families, which are pathogenic to fish, presenting their genetical properties allowing for their classification, as well as morphological properties and diseases caused.}, }
@article {pmid26159775, year = {2015}, author = {Maschio, VJ and Corção, G and Bücker, F and Caumo, K and Rott, MB}, title = {Identification of Paenibacillus as a Symbiont in Acanthamoeba.}, journal = {Current microbiology}, volume = {71}, number = {3}, pages = {415-420}, pmid = {26159775}, issn = {1432-0991}, mesh = {Acanthamoeba/*microbiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Denaturing Gradient Gel Electrophoresis ; Molecular Sequence Data ; Paenibacillus/*isolation &amp; purification/*physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Amoebae of the genus Acanthamoeba occur worldwide and in addition to being pathogens, are important vehicles for microorganisms with clinical and environmental importance. This study aimed to evaluate the profiling of endosymbionts in 12 isolates of Acanthamoeba using V3 region of 16S rDNA denaturing gradient gel electrophoresis (DGGE) and sequencing. The DGGE enabled us to characterize the endosymbionts diversity in isolates of Acanthamoeba, and to identify Paenibacillus sp., an emerging pathogen, as an amoebic endosymbiont. The results of this study demonstrated that Acanthamoeba is capable of transporting a large number of endosymbionts. This is the first study that reports, the presence of Paenibacillus sp. as amebic symbiont.}, }
@article {pmid26157152, year = {2015}, author = {Grankvist, A and Moore, ER and Svensson Stadler, L and Pekova, S and Bogdan, C and Geißdörfer, W and Grip-Lindén, J and Brandström, K and Marsal, J and Andréasson, K and Lewerin, C and Welinder-Olsson, C and Wennerås, C}, title = {Multilocus Sequence Analysis of Clinical "Candidatus Neoehrlichia mikurensis" Strains from Europe.}, journal = {Journal of clinical microbiology}, volume = {53}, number = {10}, pages = {3126-3132}, pmid = {26157152}, issn = {1098-660X}, mesh = {Aged ; Anaplasmataceae/*classification/*genetics/isolation &amp; purification ; Anaplasmataceae Infections/epidemiology/*microbiology ; Cluster Analysis ; Czech Republic/epidemiology ; Female ; Genes, Essential ; *Genetic Variation ; *Genotype ; Germany/epidemiology ; Humans ; Male ; Middle Aged ; Molecular Epidemiology/methods ; Multilocus Sequence Typing/*methods ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sweden/epidemiology ; }, abstract = {"Candidatus Neoehrlichia mikurensis" is the tick-borne agent of neoehrlichiosis, an infectious disease that primarily affects immunocompromised patients. So far, the genetic variability of "Ca. Neoehrlichia" has been studied only by comparing 16S rRNA genes and groEL operon sequences. We describe the development and use of a multilocus sequence analysis (MLSA) protocol to characterize the genetic diversity of clinical "Ca. Neoehrlichia" strains in Europe and their relatedness to other species within the Anaplasmataceae family. Six genes were selected: ftsZ, clpB, gatB, lipA, groEL, and 16S rRNA. Each MLSA locus was amplified by real-time PCR, and the PCR products were sequenced. Phylogenetic trees of MLSA locus relatedness were constructed from aligned sequences. Blood samples from 12 patients with confirmed "Ca. Neoehrlichia" infection from Sweden (n = 9), the Czech Republic (n = 2), and Germany (n = 1) were analyzed with the MLSA protocol. Three of the Swedish strains exhibited identical lipA sequences, while the lipA sequences of the strains from the other nine patients were identical to each other. One of the Czech strains had one differing nucleotide in the clpB sequence from the sequences of the other 11 strains. All 12 strains had identical sequences for the genes 16S rRNA, ftsZ, gatB, and groEL. According to the MLSA, among the Anaplasmataceae, "Ca. Neoehrlichia" is most closely related to Ehrlichia ruminantium, less so to Anaplasma phagocytophilum, and least to Wolbachia endosymbionts. To conclude, three sequence types of infectious "Ca. Neoehrlichia" were identified: one in the west of Sweden, one in the Czech Republic, and one spread throughout Europe.}, }
@article {pmid26156552, year = {2015}, author = {Kinjo, Y and Saitoh, S and Tokuda, G}, title = {An Efficient Strategy Developed for Next-Generation Sequencing of Endosymbiont Genomes Performed Using Crude DNA Isolated from Host Tissues: A Case Study of Blattabacterium cuenoti Inhabiting the Fat Bodies of Cockroaches.}, journal = {Microbes and environments}, volume = {30}, number = {3}, pages = {208-220}, pmid = {26156552}, issn = {1347-4405}, mesh = {Animals ; Bacteroidetes/classification/genetics/*isolation &amp; purification/physiology ; Cockroaches/classification/*microbiology/physiology ; Fat Body/microbiology ; *Genome, Bacterial ; High-Throughput Nucleotide Sequencing/*methods ; Host Specificity ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; }, abstract = {Whole-genome sequencing has emerged as one of the most effective means to elucidate the biological roles and molecular features of obligate intracellular symbionts (endosymbionts). However, the de novo assembly of an endosymbiont genome remains a challenge when host and/or mitochondrial DNA sequences are present in a dataset and hinder the assembly of the genome. By focusing on the traits of genome evolution in endosymbionts, we herein developed and investigated a genome-assembly strategy that consisted of two consecutive procedures: the selection of endosymbiont contigs from an output obtained from a de novo assembly performed using a TBLASTX search against a reference genome, named TBLASTX Contig Selection and Filtering (TCSF), and the iterative reassembling of the genome from reads mapped on the selected contigs, named Iterative Mapping and ReAssembling (IMRA), to merge the contigs. In order to validate this approach, we sequenced two strains of the cockroach endosymbiont Blattabacterium cuenoti and applied this strategy to the datasets. TCSF was determined to be highly accurate and sensitive in contig selection even when the genome of a distantly related free-living bacterium was used as a reference genome. Furthermore, the use of IMRA markedly improved sequence assemblies: the genomic sequence of an endosymbiont was almost completed from a dataset containing only 3% of the sequences of the endosymbiont's genome. The efficiency of our strategy may facilitate further studies on endosymbionts.}, }
@article {pmid26150447, year = {2015}, author = {Mee, PT and Weeks, AR and Walker, PJ and Hoffmann, AA and Duchemin, JB}, title = {Detection of Low-Level Cardinium and Wolbachia Infections in Culicoides.}, journal = {Applied and environmental microbiology}, volume = {81}, number = {18}, pages = {6177-6188}, pmid = {26150447}, issn = {1098-5336}, mesh = {Animals ; Australia ; Bacteroidetes/classification/genetics/*isolation &amp; purification ; Ceratopogonidae/*microbiology ; Cluster Analysis ; DNA Gyrase/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Bacterial endosymbionts have been identified as potentially useful biological control agents for a range of invertebrate vectors of disease. Previous studies of Culicoides (Diptera: Ceratopogonidae) species using conventional PCR assays have provided evidence of Wolbachia (1/33) and Cardinium (8/33) infections. Here, we screened 20 species of Culicoides for Wolbachia and Cardinium, utilizing a combination of conventional PCR and more sensitive quantitative PCR (qPCR) assays. Low levels of Cardinium DNA were detected in females of all but one of the Culicoides species screened, and low levels of Wolbachia were detected in females of 9 of the 20 Culicoides species. Sequence analysis based on partial 16S rRNA gene and gyrB sequences identified "Candidatus Cardinium hertigii" from group C, which has previously been identified in Culicoides from Japan, Israel, and the United Kingdom. Wolbachia strains detected in this study showed 98 to 99% sequence identity to Wolbachia previously detected from Culicoides based on the 16S rRNA gene, whereas a strain with a novel wsp sequence was identified in Culicoides narrabeenensis. Cardinium isolates grouped to geographical regions independent of the host Culicoides species, suggesting possible geographical barriers to Cardinium movement. Screening also identified Asaia bacteria in Culicoides. These findings point to a diversity of low-level endosymbiont infections in Culicoides, providing candidates for further characterization and highlighting the widespread occurrence of these endosymbionts in this insect group.}, }
@article {pmid26142727, year = {2015}, author = {Onda, DF and Azanza, RV and Lluisma, AO}, title = {Potential DMSP-degrading Roseobacter clade dominates endosymbiotic microflora of Pyrodinium bahamense var. compressum (Dinophyceae) in vitro.}, journal = {Archives of microbiology}, volume = {197}, number = {7}, pages = {965-971}, doi = {10.1007/s00203-015-1133-0}, pmid = {26142727}, issn = {1432-072X}, mesh = {Dinoflagellida/*microbiology ; RNA, Ribosomal, 16S/genetics ; Roseobacter/genetics/isolation &amp; purification/metabolism/*physiology ; Sulfonium Compounds/metabolism ; Symbiosis ; }, abstract = {Many aspects of the biology and ecology of the toxic dinoflagellate Pyrodinium bahamense var. compressum are still poorly understood. In this brief note, we present identification of its associated intracellular bacteria or endosymbionts via PCR cloning and 16s rRNA gene sequencing and their localization by confocal microscopy, a first for Pyrodinium. The most frequently observed species in the endosymbiotic microflora were from Roseobacter clade (Alphaproteobacteria, 68%) and Gilvibacter sediminis (Flavobacteriaceae, 20%). Roseobacter lineage, the most abundant taxa in this study, is known to be involved in dimethylsulfoniopropionate metabolism which is highly produced in dinoflagellates-a possible strong factor shaping the structure of the associated bacterial community.}, }
@article {pmid26142572, year = {2015}, author = {Sugimoto, TN and Kayukawa, T and Matsuo, T and Tsuchida, T and Ishikawa, Y}, title = {A short, high-temperature treatment of host larvae to analyze Wolbachia-host interactions in the moth Ostrinia scapulalis.}, journal = {Journal of insect physiology}, volume = {81}, number = {}, pages = {48-51}, doi = {10.1016/j.jinsphys.2015.06.016}, pmid = {26142572}, issn = {1879-1611}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Female ; Host-Pathogen Interactions ; Hot Temperature ; Larva/drug effects/growth &amp; development/microbiology ; Male ; Mosaicism ; Moths/drug effects/growth &amp; development/*microbiology ; Sex Ratio ; Tetracycline/pharmacology ; Wolbachia/*physiology ; }, abstract = {Maternally inherited endosymbiotic bacteria of the genus Wolbachia cause various reproductive alterations in their hosts. Wolbachia induces male-specific death during embryonic and larval stages in the moth Ostrinia scapulalis. To investigate how the density of Wolbachia affects their performance in the host, we attempted to reduce its density using a short, high-temperature treatment of the host at the larval stage. Individuals cured of infection as well as sexual mosaics, which harbor Wolbachia, were obtained by this method in the next generation. The sex of uninfected offspring was exclusively male, similar to that of the offspring of larvae treated with antibiotics. A strong correlation was found between Wolbachia density in female moths and the sex ratio of their progeny. These results suggest that a short, high-temperature treatment at the larval stage reduced the density of Wolbachia in the adult stage, and, hence, inhibited interference with the host's development in the next generation. Since the direct effects of the heat treatment on Wolbachia were transient, this method may be useful for specifying the critical time for interference by Wolbachia in host development.}, }
@article {pmid26132467, year = {2015}, author = {Martinez, J and Ok, S and Smith, S and Snoeck, K and Day, JP and Jiggins, FM}, title = {Should Symbionts Be Nice or Selfish? Antiviral Effects of Wolbachia Are Costly but Reproductive Parasitism Is Not.}, journal = {PLoS pathogens}, volume = {11}, number = {7}, pages = {e1005021}, pmid = {26132467}, issn = {1553-7374}, support = {/WT_/Wellcome Trust/United Kingdom ; WT094664MA/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Drosophila simulans/*microbiology ; Host-Parasite Interactions/*physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Symbiosis/*physiology ; *Wolbachia ; }, abstract = {Symbionts can have mutualistic effects that increase their host's fitness and/or parasitic effects that reduce it. Which of these strategies evolves depends in part on the balance of their costs and benefits to the symbiont. We have examined these questions in Wolbachia, a vertically transmitted endosymbiont of insects that can provide protection against viral infection and/or parasitically manipulate its hosts' reproduction. Across multiple symbiont strains we find that the parasitic phenotype of cytoplasmic incompatibility and antiviral protection are uncorrelated. Strong antiviral protection is associated with substantial reductions in other fitness-related traits, whereas no such trade-off was detected for cytoplasmic incompatibility. The reason for this difference is likely that antiviral protection requires high symbiont densities but cytoplasmic incompatibility does not. These results are important for the use of Wolbachia to block dengue virus transmission by mosquitoes, as natural selection to reduce these costs may lead to reduced symbiont density and the loss of antiviral protection.}, }
@article {pmid26130134, year = {2015}, author = {Geary, JF and Lovato, R and Wanji, S and Guderian, R and O'Neill, M and Specht, S and Madrill, N and Geary, TG and Mackenzie, CD}, title = {A histochemical study of the Nras/let-60 activity in filarial nematodes.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {353}, pmid = {26130134}, issn = {1756-3305}, mesh = {Animals ; Bacterial Outer Membrane Proteins/analysis/metabolism ; Female ; Helminth Proteins/analysis/*metabolism ; Humans ; Immunohistochemistry ; Male ; Onchocerca/chemistry/*metabolism/microbiology ; Onchocerciasis/parasitology ; Wolbachia/chemistry/metabolism ; ras Proteins/analysis/*metabolism ; }, abstract = {BACKGROUND: Control and elimination of filarial pathogens is a central focus of major global health efforts directed at parasitic diseases of developing countries. Accomplishment of these goals would be markedly enhanced by the enhanced destruction of the adult stage of filariae. The identification of new, more quantitative biomarkers that correlate with mortality or chemotherapeutic damage to adult filariae, would greatly facilitate, for example, the development of new macrofilaricides.<br><br>METHODS: An immunocytochemical approach using an antibody against human Nras was used to identify and detect changes in the nematode homolog let-60 that is associated with cell growth and maintenance. Single Onchocerca volvulus nodules were removed from each of 13 patients treated with ivermectin (as part of a community-wide mass drug administration programme), and from each of 13 untreated individuals; these 26 nodules were stained with the anti-Nras antibody. The localization and degree of positivity of Nras/let-60 staining were assessed subjectively and compared between the two groups; the positivity of staining was also quantified, using image analysis, in a subgroup of these nodules. In addition, the specific morphological association between Nras/let-60 and the Wolbachia endosymbiont present in these parasites was also observed in 4 additional filarial species using an anti-Wolbachia surface protein (WSP) antibody under light and confocal microscopy.<br><br>RESULTS: Nras/let-60 is present in many structures within the adult female worms. A statistically significant decrease in the general staining intensity of Nras/let-60 was observed in adult female O. volvulus treated with ivermectin when compared with parasites from untreated patients. Nras/let-60 staining was frequently observed to be co-localized with WSP in O.volvulus, Brugia malayi, Litomosoides sigmodontis and Dirofilaria immitis. Nras/let60 is also present in Onchocerca ochengi.<br><br>CONCLUSION: Nras/let-60, as detected by immunocytochemical staining, is decreased in ivermectin-treated adult female O. volvulus relative to untreated control specimens, suggesting a suppressive effect of ivermectin on the overall biochemical activity of these parasites. Co-localization of Nras/let-60 and WSP suggests the possibility that the endosymbiont utilizes this nematode protein as part of a mutualistic relationship. Nras/let60 appears to be a useful biomarker for assessing the health of filariae.}, }
@article {pmid26124449, year = {2015}, author = {Ruiz-Jones, LJ and Palumbi, SR}, title = {Transcriptome-wide Changes in Coral Gene Expression at Noon and Midnight Under Field Conditions.}, journal = {The Biological bulletin}, volume = {228}, number = {3}, pages = {227-241}, doi = {10.1086/BBLv228n3p227}, pmid = {26124449}, issn = {1939-8697}, mesh = {American Samoa ; Animals ; Anthozoa/*genetics/*radiation effects ; Darkness ; Gene Expression Regulation/*radiation effects ; Hydrogen-Ion Concentration ; *Light ; Oxygen/metabolism ; Temperature ; Transcription Factors/genetics ; *Transcriptome ; }, abstract = {Reef-building corals experience high daily variation in their environment, food availability, and physiological activities such as calcification and photosynthesis by endosymbionts. On Ofu Island, American Samoa, we investigated day-night differences in gene expression under field conditions of changing pH, temperature, light, and oxygen. Using RNASeq techniques, we compared two replicate transcriptomes from a single coral colony of Acropora hyacinthus over six noons and five midnights. We identified 344 contigs with significant expression differences across 16,800 contigs in the transcriptome, most with small fold-changes. However, there were 21 contigs with fold-changes ranging from 10 to 141. The largest changes were in a set of transcription factors strongly associated with day-night gene regulation in other animals, including cryptochromes, thyrotroph embryonic factor, and D site-binding protein. We also found large daytime increases in a set of genes involved in glucose transport and glycogen storage. We found small expression differences in genes associated with aerobic ATP production and hypoxia response, along with slightly higher expression of most calcification genes at noon. Although >40-fold-changes in expression occur in important transcription factors, downstream gene regulation seems very stable in corals from day to night compared to other animals studied.}, }
@article {pmid26119974, year = {2016}, author = {Zheng, H and Dietrich, C and Radek, R and Brune, A}, title = {Endomicrobium proavitum, the first isolate of Endomicrobia class. nov. (phylum Elusimicrobia)--an ultramicrobacterium with an unusual cell cycle that fixes nitrogen with a Group IV nitrogenase.}, journal = {Environmental microbiology}, volume = {18}, number = {1}, pages = {191-204}, doi = {10.1111/1462-2920.12960}, pmid = {26119974}, issn = {1462-2920}, mesh = {Acetylene/metabolism ; Animals ; Bacteria/*classification/*genetics/isolation &amp; purification/metabolism ; Cell Cycle/genetics ; Isoptera/*microbiology ; Nitrogen/metabolism ; Nitrogen Fixation/*genetics ; Nitrogenase/*genetics/metabolism ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis/genetics ; }, abstract = {The bacterial tree contains many deep-rooting clades without any cultured representatives. One such clade is 'Endomicrobia', a class-level lineage in the phylum Elusimicrobia represented so far only by intracellular symbionts of termite gut flagellates. Here, we report the isolation and characterization of the first free-living member of this clade from sterile-filtered gut homogenate of defaunated (starch-fed) Reticulitermes santonensis. Strain Rsa215 is a strictly anaerobic ultramicrobacterium that grows exclusively on glucose, which is fermented to lactate, acetate, hydrogen and CO2. Ultrastructural analysis revealed a Gram-negative cell envelope and a peculiar cell cycle. The genome contains a single set of nif genes that encode homologues of Group IV nitrogenases, which were so far considered to have functions other than nitrogen fixation. We documented nitrogenase activity and diazotrophic growth by measuring acetylene reduction activity and (15)N2 incorporation into cell mass, and demonstrated that transcription of nifH and nitrogenase activity occur only in the absence of ammonium. Based on the ancestral relationship to 'Candidatus Endomicrobium trichonymphae' and other obligate endosymbionts, we propose the name 'Endomicrobium proavitum' gen. nov., sp. nov. for the first isolate of this lineage and the name 'Endomicrobia' class. nov. for the entire clade.}, }
@article {pmid26116977, year = {2015}, author = {Maróti, G and Downie, JA and Kondorosi, &#xc9;}, title = {Plant cysteine-rich peptides that inhibit pathogen growth and control rhizobial differentiation in legume nodules.}, journal = {Current opinion in plant biology}, volume = {26}, number = {}, pages = {57-63}, doi = {10.1016/j.pbi.2015.05.031}, pmid = {26116977}, issn = {1879-0356}, support = {BBS/E/J/00000012/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Cysteine/*chemistry ; Gene Expression Regulation, Plant ; Peptides/*chemistry/*metabolism ; Rhizobium/metabolism/*physiology ; Root Nodules, Plant/*microbiology ; Symbiosis/physiology ; }, abstract = {Plants must co-exist with both pathogenic and beneficial microbes. Antimicrobial peptides with broad antimicrobial activities represent one of the first lines of defense against pathogens. Many plant cysteine-rich peptides with potential antimicrobial properties have been predicted. Amongst them, defensins and defensin-like peptides are the most abundant and plants can express several hundreds of them. In some rhizobial-legume symbioses special defensin-like peptides, the nodule-specific cysteine-rich (NCR) peptides have evolved in those legumes whose symbiotic partner terminally differentiates. In Medicago truncatula, >700 NCRs exist and collectively act as plant effectors inducing irreversible differentiation of rhizobia to nitrogen-fixing bacteroids. Cationic NCR peptides have a broad range of potent antimicrobial activities but do not kill the endosymbionts.}, }
@article {pmid26108374, year = {2015}, author = {Gofton, AW and Oskam, CL and Lo, N and Beninati, T and Wei, H and McCarl, V and Murray, DC and Paparini, A and Greay, TL and Holmes, AJ and Bunce, M and Ryan, U and Irwin, P}, title = {Inhibition of the endosymbiont "Candidatus Midichloria mitochondrii" during 16S rRNA gene profiling reveals potential pathogens in Ixodes ticks from Australia.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {345}, pmid = {26108374}, issn = {1756-3305}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification/physiology ; Animals ; Arachnid Vectors/classification/*microbiology ; Australia ; Borrelia/classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Female ; Ixodes/classification/*microbiology ; Male ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; Symbiosis ; }, abstract = {BACKGROUND: The Australian paralysis tick (Ixodes holocyclus) is of significant medical and veterinary importance as a cause of dermatological and neurological disease, yet there is currently limited information about the bacterial communities harboured by these ticks and the risk of infectious disease transmission to humans and domestic animals. Ongoing controversy about the presence of Borrelia burgdorferi sensu lato (the aetiological agent of Lyme disease) in Australia increases the need to accurately identify and characterise bacteria harboured by I. holocyclus ticks.<br><br>METHODS: Universal PCR primers were used to amplify the V1-2 hyper-variable region of bacterial 16S rRNA genes present in DNA samples from I. holocyclus and I. ricinus ticks, collected in Australia and Germany respectively. The 16S amplicons were purified, sequenced on the Ion Torrent platform, and analysed in USEARCH, QIIME, and BLAST to assign genus and species-level taxonomy. Initial analysis of I. holocyclus and I. ricinus identified that > 95 % of the 16S sequences recovered belonged to the tick intracellular endosymbiont "Candidatus Midichloria mitochondrii" (CMM). A CMM-specific blocking primer was designed that decreased CMM sequences by approximately 96 % in both tick species and significantly increased the total detectable bacterial diversity, allowing identification of medically important bacterial pathogens that were previously masked by CMM.<br><br>RESULTS: Borrelia burgdorferi sensu lato was identified in German I. ricinus, but not in Australian I. holocyclus ticks. However, bacteria of medical significance were detected in I. holocyclus ticks, including a Borrelia relapsing fever group sp., Bartonella henselae, novel "Candidatus Neoehrlichia" spp., Clostridium histolyticum, Rickettsia spp., and Leptospira inadai.<br><br>CONCLUSIONS: Abundant bacterial endosymbionts, such as CMM, limit the effectiveness of next-generation 16S bacterial community profiling in arthropods by masking less abundant bacteria, including pathogens. Specific blocking primers that inhibit endosymbiont 16S amplification during PCR are an effective way of reducing this limitation. Here, this strategy provided the first evidence of a relapsing fever Borrelia sp. and of novel "Candidatus Neoehrlichia" spp. in Australia. Our results raise new questions about tick-borne pathogens in I. holocyclus ticks.}, }
@article {pmid26106901, year = {2015}, author = {Guefrachi, I and Pierre, O and Timchenko, T and Alunni, B and Barrière, Q and Czernic, P and Villaécija-Aguilar, JA and Verly, C and Bourge, M and Fardoux, J and Mars, M and Kondorosi, E and Giraud, E and Mergaert, P}, title = {Bradyrhizobium BclA Is a Peptide Transporter Required for Bacterial Differentiation in Symbiosis with Aeschynomene Legumes.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {28}, number = {11}, pages = {1155-1166}, doi = {10.1094/MPMI-04-15-0094-R}, pmid = {26106901}, issn = {0894-0282}, mesh = {Bacterial Proteins/genetics/*metabolism ; Bradyrhizobium/genetics/*metabolism/physiology ; Fabaceae/metabolism/microbiology ; Flow Cytometry ; Genetic Complementation Test ; Host-Pathogen Interactions ; Medicago/metabolism/microbiology ; Membrane Transport Proteins/classification/genetics/*metabolism ; Microscopy, Confocal ; Molecular Sequence Data ; Mutation ; Peptides/metabolism ; Phylogeny ; Polyploidy ; Root Nodules, Plant/metabolism/microbiology ; Sinorhizobium meliloti/genetics/metabolism/physiology ; *Symbiosis ; }, abstract = {Nodules of legume plants are highly integrated symbiotic systems shaped by millions of years of evolution. They harbor nitrogen-fixing rhizobium bacteria called bacteroids. Several legume species produce peptides called nodule-specific cysteine-rich (NCR) peptides in the symbiotic nodule cells which house the bacteroids. NCR peptides are related to antimicrobial peptides of innate immunity. They induce the endosymbionts into a differentiated, enlarged, and polyploid state. The bacterial symbionts, on their side, evolved functions for the response to the NCR peptides. Here, we identified the bclA gene of Bradyrhizobium sp. strains ORS278 and ORS285, which is required for the formation of differentiated and functional bacteroids in the nodules of the NCR peptide-producing Aeschynomene legumes. The BclA ABC transporter promotes the import of NCR peptides and provides protection against the antimicrobial activity of these peptides. Moreover, BclA can complement the role of the related BacA transporter of Sinorhizobium meliloti, which has a similar symbiotic function in the interaction with Medicago legumes.}, }
@article {pmid26099175, year = {2015}, author = {Lill, R and Dutkiewicz, R and Freibert, SA and Heidenreich, T and Mascarenhas, J and Netz, DJ and Paul, VD and Pierik, AJ and Richter, N and Stümpfig, M and Srinivasan, V and Stehling, O and Mühlenhoff, U}, title = {The role of mitochondria and the CIA machinery in the maturation of cytosolic and nuclear iron-sulfur proteins.}, journal = {European journal of cell biology}, volume = {94}, number = {7-9}, pages = {280-291}, doi = {10.1016/j.ejcb.2015.05.002}, pmid = {26099175}, issn = {1618-1298}, mesh = {ATP-Binding Cassette Transporters/*metabolism ; Cell Nucleus/metabolism ; Cytosol/*metabolism ; Humans ; Iron-Sulfur Proteins/*metabolism ; Membrane Transport Proteins/metabolism ; Mitochondria/*metabolism ; Mitochondrial Proteins/*metabolism ; Protein Transport/physiology ; }, abstract = {Mitochondria have been derived from alpha-bacterial endosymbionts during the evolution of eukaryotes. Numerous bacterial functions have been maintained inside the organelles including fatty acid degradation, citric acid cycle, oxidative phosphorylation, and the synthesis of heme or lipoic acid cofactors. Additionally, mitochondria have inherited the bacterial iron-sulfur cluster assembly (ISC) machinery. Many of the ISC components are essential for cell viability because they generate a still unknown, sulfur-containing compound for the assembly of cytosolic and nuclear Fe/S proteins that perform important functions in, e.g., protein translation, DNA synthesis and repair, and chromosome segregation. The sulfur-containing compound is exported by the mitochondrial ABC transporter Atm1 (human ABCB7) and utilized by components of the cytosolic iron-sulfur protein assembly (CIA) machinery. An appealing minimal model for the striking compartmentation of eukaryotic Fe/S protein biogenesis is provided by organisms that contain mitosomes instead of mitochondria. Mitosomes have been derived from mitochondria by reductive evolution, during which they have lost virtually all classical mitochondrial tasks. Nevertheless, mitosomes harbor all core ISC components which presumably have been maintained for assisting the maturation of cytosolic-nuclear Fe/S proteins. The current review is centered around the Atm1 export process. We present an overview on the mitochondrial requirements for the export reaction, summarize recent insights into the 3D structure and potential mechanism of Atm1, and explain how the CIA machinery uses the mitochondrial export product for the assembly of cytosolic and nuclear Fe/S proteins.}, }
@article {pmid26086337, year = {2015}, author = {Jeffries, CL and Walker, T}, title = {The Potential Use of Wolbachia-Based Mosquito Biocontrol Strategies for Japanese Encephalitis.}, journal = {PLoS neglected tropical diseases}, volume = {9}, number = {6}, pages = {e0003576}, pmid = {26086337}, issn = {1935-2735}, support = {/WT_/Wellcome Trust/United Kingdom ; 101285/WT_/Wellcome Trust/United Kingdom ; 101285/Z/13/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Cattle ; Culex/*microbiology ; Encephalitis Virus, Japanese/*physiology ; Encephalitis, Japanese/*prevention &amp; control/transmission ; Humans ; Insect Vectors/*microbiology ; Pest Control, Biological/*methods ; Swine ; Wolbachia/*physiology ; Zoonoses/prevention &amp; control ; }, abstract = {Japanese encephalitis virus (JEV) is a zoonotic pathogen transmitted by the infectious bite of Culex mosquitoes. The virus causes the development of the disease Japanese encephalitis (JE) in a small proportion of those infected, predominantly affecting children in eastern and southern Asia. Annual JE incidence estimates range from 50,000-175,000, with 25%-30% of cases resulting in mortality. It is estimated that 3 billion people live in countries in which JEV is endemic. The virus exists in an enzootic transmission cycle, with mosquitoes transmitting JEV between birds as reservoir hosts and pigs as amplifying hosts. Zoonotic infection occurs as a result of spillover events from the main transmission cycle. The reservoir avian hosts include cattle egrets, pond herons, and other species of water birds belonging to the family Ardeidae. Irrigated rice fields provide an ideal breeding ground for mosquitoes and attract migratory birds, maintaining the transmission of JEV. Although multiple vaccines have been developed for JEV, they are expensive and require multiple doses to maintain efficacy and immunity. As humans are a "dead-end" host for the virus, vaccination of the human population is unlikely to result in eradication. Therefore, vector control of the principal mosquito vector, Culex tritaeniorhynchus, represents a more promising strategy for reducing transmission. Current vector control strategies include intermittent irrigation of rice fields and space spraying of insecticides during outbreaks. However, Cx. Tritaeniorhynchus is subject to heavy exposure to pesticides in rice fields, and as a result, insecticide resistance has developed. In recent years, significant advancements have been made in the potential use of the bacterial endosymbiont Wolbachia for mosquito biocontrol. The successful transinfection of Wolbachia strains from Drosophila flies to Aedes (Stegomyia) mosquitoes has resulted in the generation of "dengue-refractory" mosquito lines. The successful establishment of Wolbachia in wild Aedes aegypti populations has recently been demonstrated, and open releases in dengue-endemic countries are ongoing. This review outlines the current control methods for JEV in addition to highlighting the potential use of Wolbachia-based biocontrol strategies to impact transmission. JEV and dengue virus are both members of the Flavivirus genus, and the successful establishment of Drosophila Wolbachia strains in Cx. Tritaeniorhynchus, as the principal vector of JEV, is predicted to significantly impact JEV transmission.}, }
@article {pmid26085836, year = {2015}, author = {Chen, C and Copley, JT and Linse, K and Rogers, AD and Sigwart, JD}, title = {The heart of a dragon: 3D anatomical reconstruction of the 'scaly-foot gastropod' (Mollusca: Gastropoda: Neomphalina) reveals its extraordinary circulatory system.}, journal = {Frontiers in zoology}, volume = {12}, number = {}, pages = {13}, pmid = {26085836}, issn = {1742-9994}, abstract = {INTRODUCTION: The 'scaly-foot gastropod' (Chrysomallon squamiferum Chen et al., 2015) from deep-sea hydrothermal vent ecosystems of the Indian Ocean is an active mobile gastropod occurring in locally high densities, and it is distinctive for the dermal scales covering the exterior surface of its foot. These iron-sulfide coated sclerites, and its nutritional dependence on endosymbiotic bacteria, are both noted as adaptations to the extreme environment in the flow of hydrogen sulfide. We present evidence for other adaptations of the 'scaly-foot gastropod' to life in an extreme environment, investigated through dissection and 3D tomographic reconstruction of the internal anatomy.<br><br>RESULTS: Our anatomical investigations of juvenile and adult specimens reveal a large unganglionated nervous system, a simple and reduced digestive system, and that the animal is a simultaneous hermaphrodite. We show that Chrysomallon squamiferum relies on endosymbiotic bacteria throughout post-larval life. Of particular interest is the circulatory system: Chrysomallon has a very large ctenidium supported by extensive blood sinuses filled with haemocoel. The ctenidium provides oxygen for the host but the circulatory system is enlarged beyond the scope of other similar vent gastropods. At the posterior of the ctenidium is a remarkably large and well-developed heart. Based on the volume of the auricle and ventricle, the heart complex represents approximately 4&#xa0;% of the body volume. This proportionally giant heart primarily sucks blood through the ctenidium and supplies the highly vascularised oesophageal gland. Thus we infer the elaborate cardiovascular system most likely evolved to oxygenate the endosymbionts in an oxygen poor environment and/or to supply hydrogen sulfide to the endosymbionts.<br><br>CONCLUSIONS: This study exemplifies how understanding the autecology of an organism can be enhanced by detailed investigation of internal anatomy. This gastropod is a large and active species that is abundant in its hydrothermal vent field ecosystem. Yet all of its remarkable features-protective dermal sclerites, circulatory system, high fecundity-can be viewed as adaptations beneficial to its endosymbiont microbes. We interpret these results to show that, as a result of specialisation to resolve energetic needs in an extreme chemosynthetic environment, this dramatic dragon-like species has become a carrying vessel for its bacteria.}, }
@article {pmid26079086, year = {2015}, author = {Gould, SB and Maier, UG and Martin, WF}, title = {Protein import and the origin of red complex plastids.}, journal = {Current biology : CB}, volume = {25}, number = {12}, pages = {R515-21}, doi = {10.1016/j.cub.2015.04.033}, pmid = {26079086}, issn = {1879-0445}, mesh = {Models, Biological ; Phylogeny ; Plastids/*metabolism ; Protein Transport ; Symbiosis ; }, abstract = {The number and nature of endosymbioses involving red algal endosymbionts are debated. Gene phylogenies have become the most popular tool to untangle this issue, but they deliver conflicting results. As gene and lineage sampling has increased, so have both the number of conflicting trees and the number of suggestions in the literature for multiple tertiary, and even quaternary, symbioses that might reconcile the tree conflicts. Independent lines of evidence that can address the issue are needed. Here we summarize the mechanism and machinery of protein import into complex red plastids. The process involves protein translocation machinery, known as SELMA, that arose once in evolution, that facilitates protein import across the second outermost of the four plastid membranes, and that is always targeted specifically to that membrane, regardless of where it is encoded today. It is widely accepted that the unity of protein import across the two membranes of primary plastids is strong evidence for their single cyanobacterial origin. Similarly, the unity of SELMA-dependent protein import across the second outermost plastid membrane constitutes strong evidence for the existence of a single red secondary endosymbiotic event at the common origin of all red complex plastids. We furthermore propose that the two outer membranes of red complex plastids are derived from host endoplasmic reticulum in the initial red secondary endosymbiotic event.}, }
@article {pmid26074913, year = {2015}, author = {Bueno, E and Mania, D and Frostegard, &#x1fa; and Bedmar, EJ and Bakken, LR and Delgado, MJ}, title = {Anoxic growth of Ensifer meliloti 1021 by N2O-reduction, a potential mitigation strategy.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {537}, pmid = {26074913}, issn = {1664-302X}, abstract = {Denitrification in agricultural soils is a major source of N2O. Legume crops enhance N2O emission by providing N-rich residues, thereby stimulating denitrification, both by free-living denitrifying bacteria and by the symbiont (rhizobium) within the nodules. However, there are limited data concerning N2O production and consumption by endosymbiotic bacteria associated with legume crops. It has been reported that the alfalfa endosymbiont Ensifer meliloti strain 1021, despite possessing and expressing the complete set of denitrification enzymes, is unable to grow via nitrate respiration under anoxic conditions. In the present study, we have demonstrated by using a robotized incubation system that this bacterium is able to grow through anaerobic respiration of N2O to N2. N2O reductase (N2OR) activity was not dependent on the presence of nitrogen oxyanions or NO, thus the expression could be induced by oxygen depletion alone. When incubated at pH 6, E. meliloti was unable to reduce N2O, corroborating previous observations found in both, extracted soil bacteria and Paracoccus denitrificans pure cultures, where expression of functional N2O reductase is difficult at low pH. Furthermore, the presence in the medium of highly reduced C-substrates, such as butyrate, negatively affected N2OR activity. The emission of N2O from soils can be lowered if legumes plants are inoculated with rhizobial strains overexpressing N2O reductase. This study demonstrates that strains like E. meliloti 1021, which do not produce N2O but are able to reduce the N2O emitted by other organisms, could act as even better N2O sinks.}, }
@article {pmid26064597, year = {2015}, author = {Bongaerts, P and Carmichael, M and Hay, KB and Tonk, L and Frade, PR and Hoegh-Guldberg, O}, title = {Prevalent endosymbiont zonation shapes the depth distributions of scleractinian coral species.}, journal = {Royal Society open science}, volume = {2}, number = {2}, pages = {140297}, pmid = {26064597}, issn = {2054-5703}, abstract = {Bathymetric distributions of photosynthetic marine invertebrate species are relatively well studied, however the importance of symbiont zonation (i.e. hosting of distinct algal endosymbiont communities over depth) in determining these depth distributions still remains unclear. Here, we assess the prevalence of symbiont zonation in tropical scleractinian corals by genotyping the Symbiodinium of the 25 most common species over a large depth range (down to 60 m) on a Caribbean reef. Symbiont depth zonation was found to be common on a reef-wide scale (11 out of 25 coral species), and a dominant feature in species with the widest depth distributions. With regards to reproductive strategy, symbiont zonation was more common in broadcasting species, which also exhibited a higher level of polymorphism in the symbiont zonation (i.e. number of different Symbiodinium profiles involved). Species with symbiont zonation exhibited significantly broader depth distributions than those without, highlighting the role of symbiont zonation in shaping the vertical distributions of the coral host. Overall, the results demonstrate that coral reefs can consist of highly structured communities over depth when considering both the coral host and their obligate photosymbionts, which probably has strong implications for the extent of connectivity between shallow and mesophotic habitats.}, }
@article {pmid26056318, year = {2015}, author = {Cooper, WR and Garczynski, SF and Horton, DR}, title = {Relative Abundance of Carsonella ruddii (Gamma Proteobacterium) in Females and Males of Cacopsylla pyricola (Hemiptera: Psyllidae) and Bactericera cockerelli (Hemiptera: Triozidae).}, journal = {Journal of insect science (Online)}, volume = {15}, number = {1}, pages = {}, pmid = {26056318}, issn = {1536-2442}, mesh = {Age Factors ; Animals ; Female ; *Gammaproteobacteria ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Male ; Oocytes/microbiology ; Ovary/microbiology ; Real-Time Polymerase Chain Reaction ; Sex Factors ; Symbiosis ; }, abstract = {Carsonella ruddii (Gamma Proteobacterium) is an obligate bacterial endosymbiont of psyllids that produces essential amino acids that are lacking in the insect's diet. Accurate estimations of Carsonella populations are important to studies of Carsonella-psyllid interactions and to developing ways to target Carsonella for control of psyllid pests including pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae) and potato psyllid, Bactericera cockerelli (Šulc) (Hemiptera: Triozidae). We used two methods, namely fluorescence in situ hybridization and quantitative polymerase chain reaction (qPCR), to estimate relative abundance of Carsonella in bacteriocytes and whole bodies of psyllids, respectively. Using these two methods, we compared Carsonella populations between female and male insects. Estimations using fluorescence in situ hybridization indicated that Carsonella was more abundant in bacteriocytes of female C. pyricola than in those of males, but Carsonella abundance in bacteriocytes did not differ between sexes of B. cockerelli. Analyses by qPCR using whole-body specimens indicated Carsonella was more abundant in females than in males of both psyllids. Neither fluorescence in situ hybridization nor qPCR indicated that Carsonella populations differed in abundance among adults of different ages (0-3 wk after adult eclosion). Using fluorescence in situ hybridization, Carsonella was observed in ovarioles of newly emerged females and formed an aggregation in the posterior end of mature oocytes. Results of our study indicate that female psyllids harbor greater populations of Carsonella than do males and that sex should be controlled for in studies which require estimations of Carsonella populations.}, }
@article {pmid26056315, year = {2015}, author = {Kuo, CH}, title = {Scrambled and not-so-tiny genomes of fungal endosymbionts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {25}, pages = {7622-7623}, pmid = {26056315}, issn = {1091-6490}, mesh = {Bacteria/*genetics ; *Gene Transfer Techniques ; *Genome, Bacterial ; Glomeromycota/*physiology ; *Mosaicism ; Mycoplasma/*genetics ; *Mycorrhizae ; }, }
@article {pmid26053523, year = {2015}, author = {Haselkorn, TS and Jaenike, J}, title = {Macroevolutionary persistence of heritable endosymbionts: acquisition, retention and expression of adaptive phenotypes in Spiroplasma.}, journal = {Molecular ecology}, volume = {24}, number = {14}, pages = {3752-3765}, doi = {10.1111/mec.13261}, pmid = {26053523}, issn = {1365-294X}, mesh = {Animals ; *Biological Evolution ; Disease Resistance ; Drosophila/*microbiology/parasitology ; Female ; Male ; Molecular Sequence Data ; Phenotype ; Phylogeny ; Species Specificity ; Spiroplasma/*genetics ; *Symbiosis ; }, abstract = {The phylogenetic incongruence between insects and their facultative maternally transmitted endosymbionts indicates that these infections are generally short-lived evolutionarily. Therefore, long-term persistence of many endosymbionts must depend on their ability to colonize and spread within new host species. At least 17 species of Drosophila are infected with endosymbiotic Spiroplasma that have various phenotypic effects. We transinfected five strains of Spiroplasma from three divergent clades into Drosophila neotestacea to test their capacity to spread in a novel host. A strain that causes male killing in Drosophila melanogaster (its native host) also does so in D. neotestacea, even though these host species diverged 40-60 mya. A strain native to D. neotestacea (designated sNeo) and the two other strains of the poulsonii clade of Spiroplasma confer resistance to wasp parasitism, suggesting that this trait may be ancestral within this clade of Spiroplasma. Conversely, no strain other than sNeo conferred resistance to the sterilizing effects of nematode parasitism, suggesting that nematode resistance is a recently derived condition. The apparent addition of nematode resistance to a Spiroplasma lineage that already confers resistance to wasp parasitism suggests endosymbionts can increase the repertoire of traits conducive to their spread. The capacity of an endosymbiont to undergo maternal transmission and express adaptive phenotypes in novel hosts, without requiring a period of host-symbiont co-evolution, enables the spread of such symbionts immediately after the colonization of a new host. This could be critical for the macroevolutionary persistence of facultative endosymbionts whose sojourn times within individual host species are relatively brief.}, }
@article {pmid26047562, year = {2015}, author = {Limpens, E and van Zeijl, A and Geurts, R}, title = {Lipochitooligosaccharides modulate plant host immunity to enable endosymbioses.}, journal = {Annual review of phytopathology}, volume = {53}, number = {}, pages = {311-334}, doi = {10.1146/annurev-phyto-080614-120149}, pmid = {26047562}, issn = {1545-2107}, mesh = {Lipopolysaccharides/*metabolism ; Mycorrhizae/*physiology ; *Plant Immunity ; Rhizobium/*physiology ; *Signal Transduction ; *Symbiosis ; }, abstract = {Symbiotic nitrogen-fixing rhizobium bacteria and arbuscular mycorrhizal fungi use lipochitooligosaccharide (LCO) signals to communicate with potential host plants. Upon a compatible match, an intimate relation is established during which the microsymbiont is allowed to enter root (-derived) cells. Plants perceive microbial LCO molecules by specific LysM-domain-containing receptor-like kinases. These do not only activate a common symbiosis signaling pathway that is shared in both symbioses but also modulate innate immune responses. Recent studies revealed that symbiotic LCO receptors are closely related to chitin innate immune receptors, and some of these receptors even function in symbiosis as well as immunity. This raises questions about how plants manage to translate structurally very similar microbial signals into different outputs. Here, we describe the current view on chitin and LCO perception in innate immunity and endosymbiosis and question how LCOs might modulate the immune system. Furthermore, we discuss what it takes to become an endosymbiont.}, }
@article {pmid26044338, year = {2015}, author = {Nicholson, SJ and Nickerson, ML and Dean, M and Song, Y and Hoyt, PR and Rhee, H and Kim, C and Puterka, GJ}, title = {The genome of Diuraphis noxia, a global aphid pest of small grains.}, journal = {BMC genomics}, volume = {16}, number = {}, pages = {429}, pmid = {26044338}, issn = {1471-2164}, mesh = {Animals ; Aphids/classification/drug effects/*genetics/metabolism/virology ; Base Composition ; Computational Biology/methods ; Cytosine/metabolism ; DNA Methylation ; DNA Transposable Elements ; Drug Resistance ; Epigenesis, Genetic ; Genetic Linkage ; *Genome, Insect ; *Genomics/methods ; Genotype ; Insect Proteins/chemistry/genetics/metabolism ; Insect Vectors/classification/drug effects/genetics/metabolism/virology ; Insecticides/pharmacology ; Phylogeny ; RNA Interference ; Repetitive Sequences, Nucleic Acid ; Signal Transduction ; }, abstract = {BACKGROUND: The Russian wheat aphid, Diuraphis noxia Kurdjumov, is one of the most important pests of small grains throughout the temperate regions of the world. This phytotoxic aphid causes severe systemic damage symptoms in wheat, barley, and other small grains as a direct result of the salivary proteins it injects into the plant while feeding.<br><br>RESULTS: We sequenced and de novo assembled the genome of D. noxia Biotype 2, the strain most virulent to resistance genes in wheat. The assembled genomic scaffolds span 393 MB, equivalent to 93% of its 421 MB genome, and contains 19,097 genes. D. noxia has the most AT-rich insect genome sequenced to date (70.9%), with a bimodal CpG(O/E) distribution and a complete set of methylation related genes. The D. noxia genome displays a widespread, extensive reduction in the number of genes per ortholog group, including defensive, detoxification, chemosensory, and sugar transporter groups in comparison to the Acyrthosiphon pisum genome, including a 65% reduction in chemoreceptor genes. Thirty of 34 known D. noxia salivary genes were found in this assembly. These genes exhibited less homology with those salivary genes commonly expressed in insect saliva, such as glucose dehydrogenase and trehalase, yet greater conservation among genes that are expressed in D. noxia saliva but not detected in the saliva of other insects. Genes involved in insecticide activity and endosymbiont-derived genes were also found, as well as genes involved in virus transmission, although D. noxia is not a viral vector.<br><br>CONCLUSIONS: This genome is the second sequenced aphid genome, and the first of a phytotoxic insect. D. noxia's reduced gene content of may reflect the influence of phytotoxic feeding in shaping the D. noxia genome, and in turn in broadening its host range. The presence of methylation-related genes, including cytosine methylation, is consistent with other parthenogenetic and polyphenic insects. The D. noxia genome will provide an important contrast to the A. pisum genome and advance functional and comparative genomics of insects and other organisms.}, }
@article {pmid26042046, year = {2015}, author = {Zhang, F and Li, X and Zhang, Y and Coates, B and Zhou, XJ and Cheng, D}, title = {Bacterial symbionts, Buchnera, and starvation on wing dimorphism in English grain aphid, Sitobion avenae (F.) (Homoptera: Aphididae).}, journal = {Frontiers in physiology}, volume = {6}, number = {}, pages = {155}, pmid = {26042046}, issn = {1664-042X}, abstract = {Wing dimorphism in aphids can be affected by multiple cues, including both biotic (nutrition, crowding, interspecific interactions, the presence of natural enemies, maternal and transgenerational effects, and alarm pheromone) and abiotic factors (temperature, humidity, and photoperiod). The majority of the phloem-feeding aphids carry Buchnera, an obligate symbiotic proteobacteria. Buchnera has a highly reduced genome size, but encode key enzymes in the tryptophan biosynthetic pathway and is crucial for nutritional balance, development and reproduction in aphids. In this study, we investigated the impact of two nutritional-based biotic factors, symbionts and starvation, on the wing dimorphism in the English grain aphid, Sitobion avenae, a devastating insect pest of cereal crops (e.g., wheat) worldwide. Elimination of Buchnera using the antibiotic rifampicin significantly reduced the formation of winged morphs, body mass, and fecundity in S. avenae. Furthermore, the absence of this primary endosymbiont may disrupt the nutrient acquisition in aphids and alter transgenerational phenotypic expression. Similarly, both survival rate and the formation of winged morphs were substantially reduced after neonatal (<24 h old) offspring were starved for a period of time. The combined results shed light on the impact of two nutritional-based biotic factors on the phenotypic plasticity in aphids. A better understanding of the wing dimorphism in aphids will provide the theoretical basis for the prediction and integrated management of these phloem-feeding insect pests.}, }
@article {pmid26041060, year = {2015}, author = {Kaur, T and Singh, B and Kaur, A and Kaur, S}, title = {Endophyte-mediated interactions between cauliflower, the herbivore Spodoptera litura, and the ectoparasitoid Bracon hebetor.}, journal = {Oecologia}, volume = {179}, number = {2}, pages = {487-494}, pmid = {26041060}, issn = {1432-1939}, mesh = {Animals ; Brassica/*microbiology ; Endophytes/*physiology ; Female ; *Herbivory ; Host-Parasite Interactions ; Larva/metabolism/physiology ; Spodoptera/growth &amp; development/parasitology/*physiology ; Symbiosis ; Wasps/growth &amp; development/*physiology ; }, abstract = {Fungal endosymbionts in plants may influence interactions among plants, herbivores and their parasitoids through the production of secondary metabolites. We used a lepidopteran pest and its generalist parasitoid to test the effect of endophyte-infected plants on a third trophic level. Endophytic fungi, Aspergillus flavus and Aspergillus niger, isolated from Acacia arabica, were used to infect cauliflower plants. We found that the presence of the endophyte in the plants significantly extended the development period of Spodoptera litura (Fab.) larvae. Feeding of the host on endophyte-infected plants further adversely affected the development and performance of its parasitoid, Bracon hebetor (Say). A negative impact was also recorded for longevity and fecundity of endophyte-naive parasitoid females due to the parasitization of host larvae fed on endophyte-infected plants. The presence of endophytes in the diet of the host larvae significantly prolonged the development of the parasitoid. A strong detrimental effect was also recorded for larval survival and emergence of parasitoid adults. The longevity and parasitism rate of female wasps were reduced significantly due to the ingestion of endophyte-infected cauliflower plants by S. litura larvae. Overall, we found that both endophytic fungi had a negative impact on the parasitoid.}, }
@article {pmid26039986, year = {2015}, author = {Wilson, AC and Duncan, RP}, title = {Signatures of host/symbiont genome coevolution in insect nutritional endosymbioses.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10255-10261}, pmid = {26039986}, issn = {1091-6490}, mesh = {Amino Acids/chemistry ; Amino Acids, Branched-Chain/chemistry ; Animals ; Bacteria/genetics ; Buchnera/genetics ; Cell Lineage ; Cytoplasm/metabolism ; *Evolution, Molecular ; Gene Expression Profiling ; Gene Transfer, Horizontal ; Genome ; Genome, Bacterial ; Hemiptera/*genetics/*microbiology ; Pantothenic Acid/chemistry ; *Symbiosis ; }, abstract = {The role of symbiosis in bacterial symbiont genome evolution is well understood, yet the ways that symbiosis shapes host genomes or more particularly, host/symbiont genome coevolution in the holobiont is only now being revealed. Here, we identify three coevolutionary signatures that characterize holobiont genomes. The first signature, host/symbiont collaboration, arises when completion of essential pathways requires host/endosymbiont genome complementarity. Metabolic collaboration has evolved numerous times in the pathways of amino acid and vitamin biosynthesis. Here, we highlight collaboration in branched-chain amino acid and pantothenate (vitamin B5) biosynthesis. The second coevolutionary signature is acquisition, referring to the observation that holobiont genomes acquire novel genetic material through various means, including gene duplication, lateral gene transfer from bacteria that are not their current obligate symbionts, and full or partial endosymbiont replacement. The third signature, constraint, introduces the idea that holobiont genome evolution is constrained by the processes governing symbiont genome evolution. In addition, we propose that collaboration is constrained by the expression profile of the cell lineage from which endosymbiont-containing host cells, called bacteriocytes, are derived. In particular, we propose that such differences in bacteriocyte cell lineage may explain differences in patterns of host/endosymbiont metabolic collaboration between the sap-feeding suborders Sternorrhyncha and Auchenorrhynca. Finally, we review recent studies at the frontier of symbiosis research that are applying functional genomic approaches to characterization of the developmental and cellular mechanisms of host/endosymbiont integration, work that heralds a new era in symbiosis research.}, }
@article {pmid26035130, year = {2015}, author = {Ledermann, R and Bartsch, I and Remus-Emsermann, MN and Vorholt, JA and Fischer, HM}, title = {Stable Fluorescent and Enzymatic Tagging of Bradyrhizobium diazoefficiens to Analyze Host-Plant Infection and Colonization.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {28}, number = {9}, pages = {959-967}, doi = {10.1094/MPMI-03-15-0054-TA}, pmid = {26035130}, issn = {0894-0282}, mesh = {Bacterial Proteins/genetics/*metabolism ; Bradyrhizobium/*enzymology/genetics/metabolism ; DNA, Recombinant ; Gene Expression Regulation, Bacterial/*physiology ; Gene Expression Regulation, Enzymologic/*physiology ; Luminescent Proteins/genetics/*metabolism ; Plant Roots/microbiology ; Soybeans/*microbiology ; }, abstract = {Bradyrhizobium diazoefficiens USDA 110 (formerly named Bradyrhizobium japonicum) can fix dinitrogen when living as an endosymbiont in root nodules of soybean and some other legumes. Formation of a functional symbiosis relies on a defined developmental program mediated by controlled gene expression in both symbiotic partners. In contrast to other well-studied Rhizobium-legume model systems that have been thoroughly examined by means of genetically tagged strains, analysis of B. diazoefficiens host infection has been impaired due to the lack of suitable tagging systems. Here, we describe the construction of B. diazoefficiens strains constitutively expressing single-copy genes for fluorescent proteins (eBFP2, mTurquoise2, GFP+, sYFP2, mCherry, HcRed) and enzymes (GusA, LacZ). For stable inheritance, the constructs were recombined into the chromosome. Effectiveness and versatility of the tagged strains was demonstrated in plant infection assays. (i) The infection process was followed from root-hair attachment to colonization of nodule cells with epifluorescent microscopy. (ii) Monitoring mixed infections with two strains producing different fluorescent proteins allowed rapid analysis of nodule occupancy and revealed that the majority of nodules contained clonal populations. (iii) Microscopic analysis of nodules induced by fluorescent strains provided evidence for host-dependent control of B. diazoefficiens bacteroid morphology in nodules of Aeschynomene afraspera and Arachis hypogaea (peanut), as deduced from their altered morphology compared with bacteroids in soybean nodules.}, }
@article {pmid26032249, year = {2015}, author = {Martínez-Hidalgo, P and Flores-Félix, JD and Menéndez, E and Rivas, R and Carro, L and Mateos, PF and Martínez-Molina, E and León-Barrios, M and Velázquez, E}, title = {Cicer canariense, an endemic legume to the Canary Islands, is nodulated in mainland Spain by fast-growing strains from symbiovar trifolii phylogenetically related to Rhizobium leguminosarum.}, journal = {Systematic and applied microbiology}, volume = {38}, number = {5}, pages = {346-350}, doi = {10.1016/j.syapm.2015.03.011}, pmid = {26032249}, issn = {1618-0984}, mesh = {Bacterial Proteins/genetics ; Cicer/*microbiology/*physiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases/genetics ; Phylogeny ; Plant Root Nodulation ; Rec A Recombinases/genetics ; Rhizobium leguminosarum/*classification/*isolation &amp; purification/physiology ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Sequence Homology ; Spain ; *Symbiosis ; Transcription Factors/genetics ; }, abstract = {Cicer canariense is a threatened endemic legume from the Canary Islands where it can be nodulated by mesorhizobial strains from the symbiovar ciceri, which is the common worldwide endosymbiont of Cicer arietinum linked to the genus Mesorhizobium. However, when C. canariense was cultivated in a soil from mainland Spain, where the symbiovar ciceri is present, only fast-growing rhizobial strains were unexpectedly isolated from its nodules. These strains were classified into the genus Rhizobium by analysis of the recA and atpD genes, and they were phylogenetically related to Rhizobium leguminosarum. The analysis of the nodC gene showed that the isolated strains belonged to the symbiovar trifolii that harbored a nodC allele (β allele) different to that harbored by other strains from this symbiovar. Nodulation experiments carried out with the lacZ-labeled strain RCCHU01, representative of the β nodC allele, showed that it induced curling of root hairs, infected them through infection threads, and formed typical indeterminate nodules where nitrogen fixation took place. This represents a case of exceptional performance between the symbiovar trifolii and a legume from the tribe Cicereae that opens up new possibilities and provides new insights into the study of rhizobia-legume symbiosis.}, }
@article {pmid26025907, year = {2015}, author = {Snyder, AK and Rio, RV}, title = {"Wigglesworthia morsitans" Folate (Vitamin B9) Biosynthesis Contributes to Tsetse Host Fitness.}, journal = {Applied and environmental microbiology}, volume = {81}, number = {16}, pages = {5375-5386}, pmid = {26025907}, issn = {1098-5336}, support = {R01 AI118789/AI/NIAID NIH HHS/United States ; R01AI118789/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Folic Acid/*biosynthesis ; Reproduction ; *Symbiosis ; Tsetse Flies/*microbiology/*physiology ; Wigglesworthia/*metabolism/physiology ; }, abstract = {Closely related ancient endosymbionts may retain minor genomic distinctions through evolutionary time, yet the biological relevance of these small pockets of unique loci remains unknown. The tsetse fly (Diptera: Glossinidae), the sole vector of lethal African trypanosomes (Trypanosoma spp.), maintains an ancient and obligate mutualism with species belonging to the gammaproteobacterium Wigglesworthia. Extensive concordant evolution with associated Wigglesworthia species has occurred through tsetse species radiation. Accordingly, the retention of unique symbiont loci between Wigglesworthia genomes may prove instrumental toward host species-specific biological traits. Genome distinctions between "Wigglesworthia morsitans" (harbored within Glossina morsitans bacteriomes) and the basal species Wigglesworthia glossinidia (harbored within Glossina brevipalpis bacteriomes) include the retention of chorismate and downstream folate (vitamin B9) biosynthesis capabilities, contributing to distinct symbiont metabolomes. Here, we demonstrate that these W. morsitans pathways remain functionally intact, with folate likely being systemically disseminated through a synchronously expressed tsetse folate transporter within bacteriomes. The folate produced by W. morsitans is demonstrated to be pivotal for G. morsitans sexual maturation and reproduction. Modest differences between ancient symbiont genomes may still play key roles in the evolution of their host species, particularly if loci are involved in shaping host physiology and ecology. Enhanced knowledge of the Wigglesworthia-tsetse mutualism may also provide novel and specific avenues for vector control.}, }
@article {pmid26025560, year = {2015}, author = {Gottlieb, Y and Lalzar, I and Klasson, L}, title = {Distinctive Genome Reduction Rates Revealed by Genomic Analyses of Two Coxiella-Like Endosymbionts in Ticks.}, journal = {Genome biology and evolution}, volume = {7}, number = {6}, pages = {1779-1796}, pmid = {26025560}, issn = {1759-6653}, mesh = {Animals ; Coxiella/*classification/*genetics/metabolism ; Female ; Genetic Variation ; *Genome Size ; *Genome, Bacterial ; Genomics ; Metabolic Networks and Pathways/genetics ; Molecular Sequence Data ; Phylogeny ; Rhipicephalus/*microbiology ; Symbiosis/*genetics ; }, abstract = {Genome reduction is a hallmark of symbiotic genomes, and the rate and patterns of gene loss associated with this process have been investigated in several different symbiotic systems. However, in long-term host-associated coevolving symbiont clades, the genome size differences between strains are normally quite small and hence patterns of large-scale genome reduction can only be inferred from distant relatives. Here we present the complete genome of a Coxiella-like symbiont from Rhipicephalus turanicus ticks (CRt), and compare it with other genomes from the genus Coxiella in order to investigate the process of genome reduction in a genus consisting of intracellular host-associated bacteria with variable genome sizes. The 1.7-Mb CRt genome is larger than the genomes of most obligate mutualists but has a very low protein-coding content (48.5%) and an extremely high number of identifiable pseudogenes, indicating that it is currently undergoing genome reduction. Analysis of encoded functions suggests that CRt is an obligate tick mutualist, as indicated by the possible provisioning of the tick with biotin (B7), riboflavin (B2) and other cofactors, and by the loss of most genes involved in host cell interactions, such as secretion systems. Comparative analyses between CRt and the 2.5 times smaller genome of Coxiella from the lone star tick Amblyomma americanum (CLEAA) show that many of the same gene functions are lost and suggest that the large size difference might be due to a higher rate of genome evolution in CLEAA generated by the loss of the mismatch repair genes mutSL. Finally, sequence polymorphisms in the CRt population sampled from field collected ticks reveal up to one distinct strain variant per tick, and analyses of mutational patterns within the population suggest that selection might be acting on synonymous sites. The CRt genome is an extreme example of a symbiont genome caught in the act of genome reduction, and the comparison between CLEAA and CRt indicates that losses of particular genes early on in this process can potentially greatly influence the speed of this process.}, }
@article {pmid26013440, year = {2015}, author = {Schofield, MM and Jain, S and Porat, D and Dick, GJ and Sherman, DH}, title = {Identification and analysis of the bacterial endosymbiont specialized for production of the chemotherapeutic natural product ET-743.}, journal = {Environmental microbiology}, volume = {17}, number = {10}, pages = {3964-3975}, pmid = {26013440}, issn = {1462-2920}, support = {P30 CA046592/CA/NCI NIH HHS/United States ; T32 GM008353/GM/NIGMS NIH HHS/United States ; U01 TW007404/TW/FIC NIH HHS/United States ; U01//PHS HHS/United States ; }, mesh = {Animals ; Base Sequence ; Biological Products ; Caribbean Region ; DNA, Bacterial/genetics ; Dioxoles/*metabolism ; Gammaproteobacteria/*genetics/*metabolism ; Genome, Bacterial/*genetics ; Humans ; Multigene Family ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/genetics ; Tetrahydroisoquinolines/*metabolism ; Trabectedin ; Urochordata/microbiology ; }, abstract = {Ecteinascidin 743 (ET-743, Yondelis) is a clinically approved chemotherapeutic natural product isolated from the Caribbean mangrove tunicate Ecteinascidia turbinata. Researchers have long suspected that a microorganism may be the true producer of the anticancer drug, but its genome has remained elusive due to our inability to culture the bacterium in the laboratory using standard techniques. Here, we sequenced and assembled the complete genome of the ET-743 producer, Candidatus Endoecteinascidia frumentensis, directly from metagenomic DNA isolated from the tunicate. Analysis of the ∼ 631 kb microbial genome revealed strong evidence of an endosymbiotic lifestyle and extreme genome reduction. Phylogenetic analysis suggested that the producer of the anti-cancer drug is taxonomically distinct from other sequenced microorganisms and could represent a new family of Gammaproteobacteria. The complete genome has also greatly expanded our understanding of ET-743 production and revealed new biosynthetic genes dispersed across more than 173 kb of the small genome. The gene cluster's architecture and its preservation demonstrate that the drug is likely essential to the interactions of the microorganism with its mangrove tunicate host. Taken together, these studies elucidate the lifestyle of a unique, and pharmaceutically important microorganism and highlight the wide diversity of bacteria capable of making potent natural products.}, }
@article {pmid26002880, year = {2015}, author = {Suzuki, S and Shirato, S and Hirakawa, Y and Ishida, K}, title = {Nucleomorph Genome Sequences of Two Chlorarachniophytes, Amorphochlora amoebiformis and Lotharella vacuolata.}, journal = {Genome biology and evolution}, volume = {7}, number = {6}, pages = {1533-1545}, pmid = {26002880}, issn = {1759-6653}, mesh = {Cell Nucleus/genetics ; Cercozoa/*genetics ; *Evolution, Molecular ; Genes ; *Genome ; Genome Size ; Genomics ; Introns ; Molecular Sequence Data ; Symbiosis/genetics ; }, abstract = {Many algal groups acquired complex plastids by the uptake of green and red algae through multiple secondary endosymbioses. As a result of gene loss and transfer during the endosymbiotic processes, algal endosymbiont nuclei disappeared in most cases. However, chlorarachniophytes and cryptophytes still possess a relict nucleus, so-called the nucleomorph, of the green and red algal endosymbiont, respectively. Nucleomorph genomes are an interesting and suitable model to study the reductive evolution of endosymbiotically derived genomes. To date, nucleomorph genomes have been sequenced in four cryptophyte species and two chlorarachniophyte species, including Bigelowiella natans (373 kb) and Lotharella oceanica (610 kb). In this study, we report complete nucleomorph genome sequences of two chlorarachniophytes, Amorphochlora amoebiformis and Lotharella vacuolata, to gain insight into the reductive evolution of nucleomorph genomes in the chlorarachniophytes. The nucleomorph genomes consist of three chromosomes totaling 374 and 432 kb in size in A. amoebiformis and L. vacuolata, respectively. Comparative analyses among four chlorarachniophyte nucleomorph genomes revealed that these sequences share 171 function-predicted genes (86% of total 198 function-predicted nucleomorph genes), including the same set of genes encoding 17 plastid-associated proteins, and no evidence of a recent nucleomorph-to-nucleus gene transfer was found. This suggests that chlorarachniophyte nucleomorph genomes underwent most of their reductive evolution prior to the radiation of extent members of the group. However, there are slight variations in genome size, GC content, duplicated gene number, and subtelomeric regions among the four nucleomorph genomes, suggesting that the genomes might be undergoing changes that do not affect the core functions in each species.}, }
@article {pmid25994183, year = {2015}, author = {Labeeuw, L and Martone, PT and Boucher, Y and Case, RJ}, title = {Ancient origin of the biosynthesis of lignin precursors.}, journal = {Biology direct}, volume = {10}, number = {}, pages = {23}, pmid = {25994183}, issn = {1745-6150}, mesh = {Alcohols/chemistry ; Aldehyde Oxidoreductases/metabolism ; Arabidopsis/genetics ; Biological Evolution ; Chlamydomonas/*genetics ; Chlorella/*genetics ; Computational Biology ; Dinoflagellida/genetics ; Evolution, Molecular ; Gene Transfer, Horizontal ; Haptophyta/genetics ; Lignin/*biosynthesis ; Likelihood Functions ; Photosynthesis ; Phylogeny ; Selaginellaceae/genetics ; }, abstract = {BACKGROUND: Lignin plays an important role in plant structural support and water transport, and is considered one of the hallmarks of land plants. The recent discovery of lignin or its precursors in various algae has raised questions on the evolution of its biosynthetic pathway, which could be much more ancient than previously thought. To determine the taxonomic distribution of the lignin biosynthesis genes, we screened all publicly available genomes of algae and their closest non-photosynthetic relatives, as well as representative land plants. We also performed phylogenetic analysis of these genes to decipher the evolution and origin(s) of lignin biosynthesis.<br><br>RESULTS: Enzymes involved in making p-coumaryl alcohol, the simplest lignin monomer, are found in a variety of photosynthetic eukaryotes, including diatoms, dinoflagellates, haptophytes, cryptophytes as well as green and red algae. Phylogenetic analysis of these enzymes suggests that they are ancient and spread to some secondarily photosynthetic lineages when they acquired red and/or green algal endosymbionts. In some cases, one or more of these enzymes was likely acquired through lateral gene transfer (LGT) from bacteria.<br><br>CONCLUSIONS: Genes associated with p-coumaryl alcohol biosynthesis are likely to have evolved long before the transition of photosynthetic eukaryotes to land. The original function of this lignin precursor is therefore unlikely to have been related to water transport. We suggest that it participates in the biological defense of some unicellular and multicellular algae.}, }
@article {pmid25991706, year = {2015}, author = {Konecka, E and Olszanowski, Z}, title = {A screen of maternally inherited microbial endosymbionts in oribatid mites (Acari: Oribatida).}, journal = {Microbiology (Reading, England)}, volume = {161}, number = {8}, pages = {1561-1571}, doi = {10.1099/mic.0.000114}, pmid = {25991706}, issn = {1465-2080}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Bacterial Proteins/genetics/metabolism ; Female ; Host Specificity ; Male ; Mites/classification/*microbiology/physiology ; Phylogeny ; Species Specificity ; *Symbiosis ; Wolbachia/classification/genetics/isolation &amp; purification/physiology ; }, abstract = {We determined the distribution of microbial endosymbionts as possible agents of parthenogenesis in Oribatida. We screened mites from 20 species of 14 families suspected to be parthenogenetic from the absence or rarity of males. Our research included parthenogenesis-inducing bacteria Wolbachia spp., Cardinium spp., Rickettsia spp., and additionally Arsenophonus, Spiroplasma and microsporidia that can also manipulate host reproduction. We detected the endosymbionts by PCR-based methods and transmission electron microscopy (TEM) observation of fixed and stained preparations of host cells. We detected Wolbachia only in one Oribatida species, Oppiella nova, by identifying Wolbachia genes using PCR. TEM observations confirmed infection by the endosymbiont in O. nova and its lack in other Oribatida species. Sequence analysis of hcpA and fbpA genes showed that the Wolbachia strain from O. nova was different from strains characterized in some insects, crustaceans (Isopoda), mites (Tetranychidae), springtails (Hexapoda) and roundworms (Nematoda). The analysis strongly suggested that the Wolbachia sp. strain found in O. nova did not belong to supergroups A, B, C, D, E, F, H or M. We found that the sequences of Wolbachia from O. nova were clearly distantly related to sequences from the bacteria of the other supergroups. This observation makes O. nova a unique Wolbachia host in terms of the distinction of the strain. The role of these micro-organisms in O. nova remains unknown and is an issue to investigate.}, }
@article {pmid25989164, year = {2015}, author = {Otabil, KB and Tenkorang, SB}, title = {Filarial hydrocele: a neglected condition of a neglected tropical disease.}, journal = {Journal of infection in developing countries}, volume = {9}, number = {5}, pages = {456-462}, doi = {10.3855/jidc.5346}, pmid = {25989164}, issn = {1972-2680}, mesh = {Anti-Bacterial Agents/*therapeutic use ; Doxycycline/*therapeutic use ; Elephantiasis, Filarial/*complications ; Humans ; Male ; Neglected Diseases/*drug therapy/*pathology ; Testicular Hydrocele/*drug therapy/*pathology ; Tropical Climate ; }, abstract = {Filarial hydrocele is the most common chronic manifestation of lymphatic filariasis (LF) and poses a major public health burden to several filarial endemic countries. This review highlights the socio-economic impact of the disease, the role of the immune system in hydrocele development, current diagnostic approaches, and the control and management of filarial hydrocele. In the quest to facilitate the global effort to eliminate filarial hydrocele as a neglected tropical disease, a more comprehensive understanding of the mechanisms underlying the pathogenesis and development of the condition is important. In general, success has been achieved using annual treatment with ivermectin, but much remains to be done, particularly with late-stage infected individuals where surgery remains the only option. Studies have successfully demonstrated that inhibition of embryogenesis in adult female worms occurs after weeks of tetracycline treatment. Even more intriguing was the observation that the Wolbachia endosymbionts potently induce proinflammatory cytokines such as tumor necrosis factors (TNFs) and vascular endothelial growth factors (VEGFs), which are crucial for the development of filarial hydrocele. Furthermore, reports from human studies show that doxycycline treatment significantly ameliorates filarial hydrocele and markedly reverses early-stage filarial hydrocele. However, with the enormous challenges that face LF elimination such as global funding, logistics, civil wars, and drug resistance, a more relentless and collective approach from local governments as well as other stakeholders is needed to accelerate the fight against filarial hydrocele if the goal to eliminate it by 2020 is be to achieved.}, }
@article {pmid25987230, year = {2015}, author = {Clark, JM and Yoon, KS and Kim, JH and Lee, SH and Pittendrigh, BR}, title = {Utilization of the human louse genome to study insecticide resistance and innate immune response.}, journal = {Pesticide biochemistry and physiology}, volume = {120}, number = {}, pages = {125-132}, pmid = {25987230}, issn = {1095-9939}, support = {R01 AI045062/AI/NIAID NIH HHS/United States ; R56 AI081933/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Biological Assay ; *Genome, Insect ; Humans ; Immunity, Innate ; Insecticide Resistance/*genetics ; Insecticides/toxicity ; Pediculus/*genetics/*immunology ; Pyrethrins/toxicity ; }, abstract = {Since sequencing the human body louse genome, substantial advances have occurred in the utilization of the information gathered from louse genomes and transcriptomes. Comparatively, the body louse genome contains far fewer genes involved in environmental response, such as xenobiotic detoxification and innate immune response. Additionally, the body louse maintains a primary bacterial endosymbiont, Candidatus Riesia pediculicola, and a number of bacterial pathogens that it vectors, which have genomes that are also reduced in size. Thus, human louse genomes offer unique information and tools for use in advancing our understanding of coevolution among vectors, endosymbionts and pathogens. In this review, we summarize the current literature on the extent of pediculicide resistance, the availability of new pediculicides and information establishing this organism as an efficient model to study how xenobiotic metabolism, which is involved in insecticide resistance, is induced and how insects modify their innate immune response upon bacterial challenge resulting in enhanced vector competence.}, }
@article {pmid25979941, year = {2015}, author = {Ohkuma, M and Noda, S and Hattori, S and Iida, T and Yuki, M and Starns, D and Inoue, J and Darby, AC and Hongoh, Y}, title = {Acetogenesis from H2 plus CO2 and nitrogen fixation by an endosymbiotic spirochete of a termite-gut cellulolytic protist.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10224-10230}, pmid = {25979941}, issn = {1091-6490}, mesh = {Acetic Acid/*metabolism ; Animals ; Carbon Dioxide/metabolism ; Evolution, Molecular ; Genome ; Intestines/microbiology ; Isoptera/microbiology/*physiology ; Molecular Sequence Data ; Nitrogen/chemistry ; *Nitrogen Fixation ; Phylogeny ; RNA, Ribosomal, 16S/metabolism ; Spirochaetales/*metabolism ; *Symbiosis ; }, abstract = {Symbiotic associations of cellulolytic eukaryotic protists and diverse bacteria are common in the gut microbial communities of termites. Besides cellulose degradation by the gut protists, reductive acetogenesis from H2 plus CO2 and nitrogen fixation by gut bacteria play crucial roles in the host termites' nutrition by contributing to the energy demand of termites and supplying nitrogen poor in their diet, respectively. Fractionation of these activities and the identification of key genes from the gut community of the wood-feeding termite Hodotermopsis sjoestedti revealed that substantial activities in the gut--nearly 60% of reductive acetogenesis and almost exclusively for nitrogen fixation--were uniquely attributed to the endosymbiotic bacteria of the cellulolytic protist in the genus Eucomonympha. The rod-shaped endosymbionts were surprisingly identified as a spirochete species in the genus Treponema, which usually exhibits a characteristic spiral morphology. The endosymbionts likely use H2 produced by the protist for these dual functions. Although H2 is known to inhibit nitrogen fixation in some bacteria, it seemed to rather stimulate this important mutualistic process. In addition, the single-cell genome analyses revealed the endosymbiont's potentials of the utilization of sugars for its energy requirement, and of the biosynthesis of valuable nutrients such as amino acids from the fixed nitrogen. These metabolic interactions are suitable for the dual functions of the endosymbiont and reconcile its substantial contributions in the gut.}, }
@article {pmid25979752, year = {2015}, author = {Linard, B and Crampton-Platt, A and Gillett, CP and Timmermans, MJ and Vogler, AP}, title = {Metagenome Skimming of Insect Specimen Pools: Potential for Comparative Genomics.}, journal = {Genome biology and evolution}, volume = {7}, number = {6}, pages = {1474-1489}, pmid = {25979752}, issn = {1759-6653}, mesh = {Animals ; Bacteria/genetics ; Coleoptera/*genetics/microbiology ; DNA/chemistry ; DNA, Plant/chemistry ; Gene Library ; Genomics ; Histones/genetics ; *Metagenome ; Metagenomics/*methods ; Multigene Family ; Phylogeny ; Repetitive Sequences, Nucleic Acid ; }, abstract = {Metagenomic analyses are challenging in metazoans, but high-copy number and repeat regions can be assembled from low-coverage sequencing by "genome skimming," which is applied here as a new way of characterizing metagenomes obtained in an ecological or taxonomic context. Illumina shotgun sequencing on two pools of Coleoptera (beetles) of approximately 200 species each were assembled into tens of thousands of scaffolds. Repeated low-coverage sequencing recovered similar scaffold sets consistently, although approximately 70% of scaffolds could not be identified against existing genome databases. Identifiable scaffolds included mitochondrial DNA, conserved sequences with hits to expressed sequence tag and protein databases, and known repeat elements of high and low complexity, including numerous copies of rRNA and histone genes. Assemblies of histones captured a diversity of gene order and primary sequence in Coleoptera. Scaffolds with similarity to multiple sites in available coleopteran genome sequences for Dendroctonus and Tribolium revealed high specificity of scaffolds to either of these genomes, in particular for high-copy number repeats. Numerous "clusters" of scaffolds mapped to the same genomic site revealed intra- and/or intergenomic variation within a metagenome pool. In addition to effect of taxonomic composition of the metagenomes, the number of mapped scaffolds also revealed structural differences between the two reference genomes, although the significance of this striking finding remains unclear. Finally, apparently exogenous sequences were recovered, including potential food plants, fungal pathogens, and bacterial symbionts. The "metagenome skimming" approach is useful for capturing the genomic diversity of poorly studied, species-rich lineages and opens new prospects in environmental genomics.}, }
@article {pmid25978383, year = {2015}, author = {Duron, O and Noël, V and McCoy, KD and Bonazzi, M and Sidi-Boumedine, K and Morel, O and Vavre, F and Zenner, L and Jourdain, E and Durand, P and Arnathau, C and Renaud, F and Trape, JF and Biguezoton, AS and Cremaschi, J and Dietrich, M and Léger, E and Appelgren, A and Dupraz, M and Gómez-Díaz, E and Diatta, G and Dayo, GK and Adakal, H and Zoungrana, S and Vial, L and Chevillon, C}, title = {The Recent Evolution of a Maternally-Inherited Endosymbiont of Ticks Led to the Emergence of the Q Fever Pathogen, Coxiella burnetii.}, journal = {PLoS pathogens}, volume = {11}, number = {5}, pages = {e1004892}, pmid = {25978383}, issn = {1553-7374}, mesh = {Animals ; Base Sequence ; Behavior, Animal ; *Biological Evolution ; Cell Line ; Communicable Diseases, Emerging/epidemiology/microbiology/*transmission/veterinary ; Coxiella burnetii/classification/growth &amp; development/isolation &amp; purification/*physiology ; Coxiellaceae/classification/growth &amp; development/isolation &amp; purification/physiology ; Female ; Genome, Bacterial ; *Global Health ; Humans ; Male ; Maternal-Fetal Exchange ; Microbial Viability ; Molecular Sequence Data ; Phylogeny ; Pregnancy ; Prevalence ; Q Fever/epidemiology/microbiology/*transmission/veterinary ; *Symbiosis ; Ticks/*microbiology/physiology ; }, abstract = {Q fever is a highly infectious disease with a worldwide distribution. Its causative agent, the intracellular bacterium Coxiella burnetii, infects a variety of vertebrate species, including humans. Its evolutionary origin remains almost entirely unknown and uncertainty persists regarding the identity and lifestyle of its ancestors. A few tick species were recently found to harbor maternally-inherited Coxiella-like organisms engaged in symbiotic interactions, but their relationships to the Q fever pathogen remain unclear. Here, we extensively sampled ticks, identifying new and atypical Coxiella strains from 40 of 58 examined species, and used this data to infer the evolutionary processes leading to the emergence of C. burnetii. Phylogenetic analyses of multi-locus typing and whole-genome sequencing data revealed that Coxiella-like organisms represent an ancient and monophyletic group allied to ticks. Remarkably, all known C. burnetii strains originate within this group and are the descendants of a Coxiella-like progenitor hosted by ticks. Using both colony-reared and field-collected gravid females, we further establish the presence of highly efficient maternal transmission of these Coxiella-like organisms in four examined tick species, a pattern coherent with an endosymbiotic lifestyle. Our laboratory culture assays also showed that these Coxiella-like organisms were not amenable to culture in the vertebrate cell environment, suggesting different metabolic requirements compared to C. burnetii. Altogether, this corpus of data demonstrates that C. burnetii recently evolved from an inherited symbiont of ticks which succeeded in infecting vertebrate cells, likely by the acquisition of novel virulence factors.}, }
@article {pmid25976611, year = {2015}, author = {Burroughs, AM and Zhang, D and Aravind, L}, title = {The eukaryotic translation initiation regulator CDC123 defines a divergent clade of ATP-grasp enzymes with a predicted role in novel protein modifications.}, journal = {Biology direct}, volume = {10}, number = {}, pages = {21}, pmid = {25976611}, issn = {1745-6150}, support = {//Intramural NIH HHS/United States ; }, mesh = {Adenosine Triphosphate/*chemistry ; Algorithms ; Amino Acid Sequence ; Bacterial Proteins/genetics ; Cell Cycle Proteins/*genetics ; Computational Biology ; DNA Viruses/genetics ; Eukaryotic Initiation Factor-2/metabolism ; Evolution, Molecular ; Lysine/chemistry ; Molecular Sequence Data ; Phylogeny ; Protein Structure, Tertiary ; Saccharomyces cerevisiae Proteins/*genetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; Viral Proteins/genetics ; }, abstract = {Deciphering the origin of uniquely eukaryotic features of sub-cellular systems, such as the translation apparatus, is critical in reconstructing eukaryogenesis. One such feature is the highly conserved, but poorly understood, eukaryotic protein CDC123, which regulates the abundance of the eukaryotic translation initiation eIF2 complex and binds one of its components eIF2γ. We show that the eukaryotic protein CDC123 defines a novel clade of ATP-grasp enzymes distinguished from all other members of the superfamily by a RAGNYA domain with two conserved lysines (henceforth the R2K clade). Combining the available biochemical and genetic data on CDC123 with the inferred enzymatic function, we propose that the eukaryotic CDC123 proteins are likely to function as ATP-dependent protein-peptide ligases which modify proteins by ribosome-independent addition of an oligopeptide tag. We also show that the CDC123 family emerged first in bacteria where it appears to have diversified along with the two other families of the R2K clade. The bacterial CDC123 family members are of two distinct types, one found as part of type VI secretion systems which deliver polymorphic toxins and the other functioning as potential effectors delivered to amoeboid eukaryotic hosts. Representatives of the latter type have also been independently transferred to phylogenetically unrelated amoeboid eukaryotes and their nucleo-cytoplasmic large DNA viruses. Similarly, the two other prokaryotic R2K clade families are also proposed to participate in biological conflicts between bacteriophages and their hosts. These findings add further evidence to the recently proposed hypothesis that the horizontal transfer of enzymatic effectors from the bacterial endosymbionts of the stem eukaryotes played a fundamental role in the emergence of the characteristically eukaryotic regulatory systems and sub-cellular structures.}, }
@article {pmid25970681, year = {2015}, author = {Nugnes, F and Gebiola, M and Monti, MM and Gualtieri, L and Giorgini, M and Wang, J and Bernardo, U}, title = {Genetic Diversity of the Invasive Gall Wasp Leptocybe invasa (Hymenoptera: Eulophidae) and of its Rickettsia Endosymbiont, and Associated Sex-Ratio Differences.}, journal = {PloS one}, volume = {10}, number = {5}, pages = {e0124660}, pmid = {25970681}, issn = {1932-6203}, mesh = {Animals ; Australia ; China ; Eucalyptus/parasitology ; Female ; Genetic Variation ; Male ; Ovary/*microbiology ; Parthenogenesis/genetics ; *Phylogeny ; Phylogeography ; Rickettsia/classification/*genetics ; Sequence Analysis, DNA ; Sex Ratio ; South America ; Symbiosis ; Wasps/*classification/*genetics/microbiology/pathogenicity ; }, abstract = {The blue-gum chalcid Leptocybe invasa Fisher &amp; LaSalle (Hymenoptera: Eulophidae) is a gall wasp pest of Eucalyptus species, likely native to Australia. Over the past 15 years it has invaded 39 countries on all continents where eucalypts are grown. The worldwide invasion of the blue gum chalcid was attributed to a single thelytokous morphospecies formally described in 2004. Subsequently, however, males have been recorded in several countries and the sex ratio of field populations has been found to be highly variable in different areas. In order to find an explanation for such sex ratio differences, populations of L. invasa from a broad geographical area were screened for the symbionts currently known as reproductive manipulators, and both wasps and symbionts were genetically characterized using multiple genes. Molecular analyses suggested that L. invasa is in fact a complex of two cryptic species involved in the rapid and efficient spread of the wasp, the first recovered from the Mediterranean region and South America, the latter from China. All screened specimens were infected by endosymbiotic bacteria belonging to the genus Rickettsia. Two closely related Rickettsia strains were found, each infecting one of the two putative cryptic species of L. invasa and associated with different average sex ratios. Rickettsia were found to be localized in the female reproductive tissues and transovarially transmitted, suggesting a possible role of Rickettsia as the causal agent of thelytokous parthenogenesis in L. invasa. Implications for the variation of sex ratio and for the management of L. invasa are discussed.}, }
@article {pmid25963738, year = {2015}, author = {Ma, WJ and Pannebakker, BA and van de Zande, L and Schwander, T and Wertheim, B and Beukeboom, LW}, title = {Diploid males support a two-step mechanism of endosymbiont-induced thelytoky in a parasitoid wasp.}, journal = {BMC evolutionary biology}, volume = {15}, number = {}, pages = {84}, pmid = {25963738}, issn = {1471-2148}, mesh = {Animals ; Biological Evolution ; Diploidy ; Female ; Haploidy ; Male ; Mutation ; *Parthenogenesis ; *Sex Determination Processes ; Wasps/*genetics/*microbiology/physiology ; Wolbachia/genetics ; }, abstract = {BACKGROUND: Haplodiploidy, where females develop from diploid, fertilized eggs and males from haploid, unfertilized eggs, is abundant in some insect lineages. Some species in these lineages reproduce by thelytoky that is caused by infection with endosymbionts: infected females lay haploid eggs that undergo diploidization and develop into females, while males are very rare or absent. It is generally assumed that in thelytokous wasps, endosymbionts merely diploidize the unfertilized eggs, which would then trigger female development.<br><br>RESULTS: We found that females in the parasitoid wasp Asobara japonica infected with thelytoky-inducing Wolbachia produce 0.7-1.2% male offspring. Seven to 39% of these males are diploid, indicating that diploidization and female development can be uncoupled in A. japonica. Wolbachia titer in adults was correlated with their ploidy and sex: diploids carried much higher Wolbachia titers than haploids, and diploid females carried more Wolbachia than diploid males. Data from introgression lines indicated that the development of diploid individuals into males instead of females is not caused by malfunction-mutations in the host genome but that diploid males are most likely produced when the endosymbiont fails to activate the female sex determination pathway. Our data therefore support a two-step mechanism by which endosymbionts induce thelytoky in A. japonica: diploidization of the unfertilized egg is followed by feminization, whereby each step correlates with a threshold of endosymbiont titer during wasp development.<br><br>CONCLUSIONS: Our new model of endosymbiont-induced thelytoky overthrows the view that certain sex determination mechanisms constrain the evolution of endosymbiont-induced thelytoky in hymenopteran insects. Endosymbionts can cause parthenogenesis through feminization, even in groups in which endosymbiont-diploidized eggs would develop into males following the hosts' sex determination mechanism. In addition, our model broadens our understanding of the mechanisms by which endosymbionts induce thelytoky to enhance their transmission to the next generation. Importantly, it also provides a novel window to study the yet-poorly known haplodiploid sex determination mechanisms in haplodiploid insects.}, }
@article {pmid25957689, year = {2015}, author = {Kardon, JR and Yien, YY and Huston, NC and Branco, DS and Hildick-Smith, GJ and Rhee, KY and Paw, BH and Baker, TA}, title = {Mitochondrial ClpX Activates a Key Enzyme for Heme Biosynthesis and Erythropoiesis.}, journal = {Cell}, volume = {161}, number = {4}, pages = {858-867}, pmid = {25957689}, issn = {1097-4172}, support = {T32 HL007574/HL/NHLBI NIH HHS/United States ; R01 GM049224/GM/NIGMS NIH HHS/United States ; F32DK095726/DK/NIDDK NIH HHS/United States ; F32 DK095726/DK/NIDDK NIH HHS/United States ; P01HL032262/HL/NHLBI NIH HHS/United States ; P01 HL032262/HL/NHLBI NIH HHS/United States ; R01 DK070838/DK/NIDDK NIH HHS/United States ; R01DK070838/DK/NIDDK NIH HHS/United States ; T32HL007574/HL/NHLBI NIH HHS/United States ; F32DK098866/DK/NIDDK NIH HHS/United States ; //Howard Hughes Medical Institute/United States ; F32 DK098866/DK/NIDDK NIH HHS/United States ; }, mesh = {5-Aminolevulinate Synthetase/metabolism ; Amino Acid Sequence ; Aminolevulinic Acid/metabolism ; Animals ; Biological Evolution ; Endopeptidase Clp/chemistry/genetics/*metabolism ; *Erythropoiesis ; Eukaryota/genetics/*metabolism ; Heme/*biosynthesis ; Humans ; Mitochondria/metabolism ; Mitochondrial Proteins/metabolism ; Molecular Chaperones/metabolism ; Molecular Sequence Data ; Saccharomyces cerevisiae/cytology/metabolism ; Saccharomyces cerevisiae Proteins/metabolism ; Sequence Alignment ; Zebrafish/metabolism ; }, abstract = {The mitochondrion maintains and regulates its proteome with chaperones primarily inherited from its bacterial endosymbiont ancestor. Among these chaperones is the AAA+ unfoldase ClpX, an important regulator of prokaryotic physiology with poorly defined function in the eukaryotic mitochondrion. We observed phenotypic similarity in S. cerevisiae genetic interaction data between mitochondrial ClpX (mtClpX) and genes contributing to heme biosynthesis, an essential mitochondrial function. Metabolomic analysis revealed that 5-aminolevulinic acid (ALA), the first heme precursor, is 5-fold reduced in yeast lacking mtClpX activity and that total heme is reduced by half. mtClpX directly stimulates ALA synthase in vitro by catalyzing incorporation of its cofactor, pyridoxal phosphate. This activity is conserved in mammalian homologs; additionally, mtClpX depletion impairs vertebrate erythropoiesis, which requires massive upregulation of heme biosynthesis to supply hemoglobin. mtClpX, therefore, is a widely conserved stimulator of an essential biosynthetic pathway and uses a previously unrecognized mechanism for AAA+ unfoldases.}, }
@article {pmid25948567, year = {2015}, author = {Kern, P and Cook, JM and Kageyama, D and Riegler, M}, title = {Double trouble: combined action of meiotic drive and Wolbachia feminization in Eurema butterflies.}, journal = {Biology letters}, volume = {11}, number = {5}, pages = {20150095}, pmid = {25948567}, issn = {1744-957X}, mesh = {Animals ; Butterflies/embryology/*genetics/growth &amp; development/*microbiology ; Chromosome Segregation ; Female ; Male ; *Meiosis ; Real-Time Polymerase Chain Reaction ; Sex Chromosomes ; Sex Determination Processes/*physiology ; Sex Ratio ; Wolbachia/*physiology ; }, abstract = {Arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited Wolbachia bacteria. Feminization by Wolbachia is rare but has been described for Eurema mandarina butterflies. In this species, some phenotypic and functional females, thought to be ZZ genetic males, are infected with a feminizing Wolbachia strain, wFem. Meanwhile, heterogametic WZ females are not infected with wFem. Here, we establish a quantitative PCR assay allowing reliable sexing in three Eurema species. Against expectation, all E. mandarina females, including wFem females, had only one Z chromosome that was paternally inherited. Observation of somatic interphase nuclei confirmed that W chromatin was absent in wFem females, but present in females without wFem. We conclude that the sex bias in wFem lines is due to meiotic drive (MD) that excludes the maternal Z and thus prevents formation of ZZ males. Furthermore, wFem lines may have lost the W chromosome or harbour a dysfunctional version, yet rely on wFem for female development; removal of wFem results in all-male offspring. This is the first study that demonstrates an interaction between MD and Wolbachia feminization, and it highlights endosymbionts as potentially confounding factors in MD of sex chromosomes.}, }
@article {pmid25948064, year = {2015}, author = {Debrah, AY and Specht, S and Klarmann-Schulz, U and Batsa, L and Mand, S and Marfo-Debrekyei, Y and Fimmers, R and Dubben, B and Kwarteng, A and Osei-Atweneboana, M and Boakye, D and Ricchiuto, A and Büttner, M and Adjei, O and Mackenzie, CD and Hoerauf, A}, title = {Doxycycline Leads to Sterility and Enhanced Killing of Female Onchocerca volvulus Worms in an Area With Persistent Microfilaridermia After Repeated Ivermectin Treatment: A Randomized, Placebo-Controlled, Double-Blind Trial.}, journal = {Clinical infectious diseases : an official publication of the Infectious Diseases Society of America}, volume = {61}, number = {4}, pages = {517-526}, pmid = {25948064}, issn = {1537-6591}, mesh = {Adolescent ; Adult ; Animals ; Anti-Bacterial Agents/*administration &amp; dosage ; Double-Blind Method ; Doxycycline/*administration &amp; dosage ; Female ; Filaricides/administration &amp; dosage ; Ghana ; Humans ; Ivermectin/administration &amp; dosage ; Male ; Middle Aged ; Onchocerca volvulus/*drug effects/microbiology/*physiology ; Onchocerciasis/*drug therapy ; Placebos/administration &amp; dosage ; Treatment Outcome ; Wolbachia/*drug effects ; Young Adult ; }, abstract = {BACKGROUND: Ivermectin (IVM) has been the drug of choice for the treatment of onchocerciasis. However, there have been reports of persistent microfilaridermia in individuals from an endemic area in Ghana after many rounds of IVM, raising concerns of suboptimal response or even the emergence of drug resistance. Because it is considered risky to continue relying only on IVM to combat this phenomenon, we assessed the effect of targeting the Onchocerca volvulus Wolbachia endosymbionts with doxycycline for these individuals with suboptimal response.<br><br>METHODS: One hundred sixty-seven patients, most of them with multiple rounds of IVM, were recruited in areas with IVM suboptimal response and treated with 100 mg/day doxycycline for 6 weeks. Three and 12 months after doxycycline treatment, patients took part in standard IVM treatment.<br><br>RESULTS: At 20 months after treatment, 80% of living female worms from the placebo group were Wolbachia positive, whereas only 5.1% in the doxycycline-treated group contained bacteria. Consistent with interruption of embryogenesis, none of the nodules removed from doxycycline-treated patients contained microfilariae, and 97% of those patients were without microfilaridermia, in contrast to placebo patients who remained at pretreatment levels (P < .001). Moreover, a significantly enhanced number of dead worms were observed after doxycycline.<br><br>CONCLUSIONS: Targeting the Wolbachia in O. volvulus is effective in clearing microfilariae in the skin of onchocerciasis patients with persistent microfilaridermia and in enhanced killing of adult worms after repeated standard IVM treatment. Strategies can now be developed that include doxycycline to control onchocerciasis in areas where infections persist despite the frequent use of IVM.<br><br>CLINICAL TRIALS REGISTRATION: ISRCTN 66649839.}, }
@article {pmid25944937, year = {2015}, author = {Wu, Z and Cuthbert, JM and Taylor, DR and Sloan, DB}, title = {The massive mitochondrial genome of the angiosperm Silene noctiflora is evolving by gain or loss of entire chromosomes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10185-10191}, pmid = {25944937}, issn = {1091-6490}, mesh = {Chromosomes/*ultrastructure ; DNA, Mitochondrial/genetics ; Evolution, Molecular ; Genes, Plant ; Genetic Variation ; *Genome, Mitochondrial ; Genome, Plant ; Molecular Sequence Data ; Phylogeny ; Plastids/genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Silene/*genetics ; }, abstract = {Across eukaryotes, mitochondria exhibit staggering diversity in genomic architecture, including the repeated evolution of multichromosomal structures. Unlike in the nucleus, where mitosis and meiosis ensure faithful transmission of chromosomes, the mechanisms of inheritance in fragmented mitochondrial genomes remain mysterious. Multichromosomal mitochondrial genomes have recently been found in multiple species of flowering plants, including Silene noctiflora, which harbors an unusually large and complex mitochondrial genome with more than 50 circular-mapping chromosomes totaling ∼7 Mb in size. To determine the extent to which such genomes are stably maintained, we analyzed intraspecific variation in the mitochondrial genome of S. noctiflora. Complete genomes from two populations revealed a high degree of similarity in the sequence, structure, and relative abundance of mitochondrial chromosomes. For example, there are no inversions between the genomes, and there are only nine SNPs in 25 kb of protein-coding sequence. Remarkably, however, these genomes differ in the presence or absence of 19 entire chromosomes, all of which lack any identifiable genes or contain only duplicate gene copies. Thus, these mitochondrial genomes retain a full gene complement but carry a highly variable set of chromosomes that are filled with presumably dispensable sequence. In S. noctiflora, conventional mechanisms of mitochondrial sequence divergence are being outstripped by an apparently nonadaptive process of whole-chromosome gain/loss, highlighting the inherent challenge in maintaining a fragmented genome. We discuss the implications of these findings in relation to the question of why mitochondria, more so than plastids and bacterial endosymbionts, are prone to the repeated evolution of multichromosomal genomes.}, }
@article {pmid25944805, year = {2015}, author = {Flood, BE and Jones, DS and Bailey, JV}, title = {Sedimenticola thiotaurini sp. nov., a sulfur-oxidizing bacterium isolated from salt marsh sediments, and emended descriptions of the genus Sedimenticola and Sedimenticola selenatireducens.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {65}, number = {8}, pages = {2522-2530}, doi = {10.1099/ijs.0.000295}, pmid = {25944805}, issn = {1466-5034}, mesh = {DNA, Bacterial/genetics ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; Geologic Sediments/*microbiology ; Massachusetts ; Molecular Sequence Data ; Nucleic Acid Hybridization ; Oxidation-Reduction ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sulfur/metabolism ; Sulfur-Reducing Bacteria/classification/genetics/isolation &amp; purification ; Thiosulfates/metabolism ; Vitamin K 2/chemistry ; *Wetlands ; }, abstract = {A marine facultative anaerobe, strain SIP-G1T, was isolated from salt marsh sediments, Falmouth, MA, USA. Phylogenetic analysis of its 16S rRNA gene sequence indicated that it belongs to an unclassified clade of Gammaproteobacteria that includes numerous sulfur-oxidizing bacteria that are endosymbionts of marine invertebrates endemic to sulfidic habitats. Strain SIP-G1T is a member of the genus Sedimenticola, of which there is one previously described isolate, Sedimenticola selenatireducens AK4OH1T. S. selenatireducens AK4OH1T was obtained for further characterization and comparison with strain SIP-G1T. The two strains were capable of coupling the oxidation of thiosulfate, tetrathionate, elemental sulfur and sulfide to autotrophic growth and they produced sulfur inclusions as metabolic intermediates. They showed varying degrees of O2 sensitivity, but when provided amino acids or peptides as a source of energy, they appeared more tolerant of O2 and exhibited concomitant production of elemental sulfur inclusions. The organic substrate preferences and limitations of these two organisms suggest that they possess an oxygen-sensitive carbon fixation pathway(s). Organic acids may be used to produce NADPH through the TCA cycle and are used in the formation of polyhydroxyalkanoates. Cell-wall-deficient morphotypes appeared when organic compounds (especially acetate) were present in excess and reduced sulfur was absent. Levels of DNA-DNA hybridization (∼47%) and phenotypic characterization indicate that strain SIP-G1T represents a separate species within the genus Sedimenticola, for which the name Sedimenticola thiotaurini sp. nov. is proposed. The type strain is SIP-G1T (= ATCC BAA-2640T = DSM 28581T). The results also justify emended descriptions of the genus Sedimenticola and of S. selenatireducens.}, }
@article {pmid25939848, year = {2015}, author = {Vimala, A and Ramakrishnan, C and Gromiha, MM}, title = {Identifying a potential receptor for the antibacterial peptide of sponge Axinella donnani endosymbiont.}, journal = {Gene}, volume = {566}, number = {2}, pages = {166-174}, doi = {10.1016/j.gene.2015.04.070}, pmid = {25939848}, issn = {1879-0038}, mesh = {Amino Acid Sequence ; Animals ; Anti-Bacterial Agents/*metabolism ; Molecular Sequence Data ; Peptides/*metabolism ; Phylogeny ; Porifera/*chemistry/microbiology ; Receptors, Cell Surface/*metabolism ; Sequence Homology, Amino Acid ; *Symbiosis ; }, abstract = {Marine sponges and their associated bacteria are rich sources of novel secondary metabolites with therapeutic usefulness. In our earlier work, we have identified a novel antibacterial peptide from the marine sponge Axinella donnani endosymbiotic bacteria. In this work, we have carried out a comparative genomic analysis and identified a set of 60 proteins as probable receptor which is common in all the strains. The analysis on binding substrate showed that β barrel assembly machinery (BamA) of the outer membrane protein 85 (omp85) superfamily is a potential receptor protein for the antibacterial peptide. It plays a central role in OMP biogenesis, especially in cell viability. Further, the triplet and quartet motifs RGF and YGDG, respectively in L6 loop are conserved over all the strains and these conserved residues interact with antibacterial peptide to inhibit the BamA function, which is essential for OMP biogenesis.}, }
@article {pmid25936226, year = {2015}, author = {Narasimhan, S and Fikrig, E}, title = {Tick microbiome: the force within.}, journal = {Trends in parasitology}, volume = {31}, number = {7}, pages = {315-323}, pmid = {25936226}, issn = {1471-5007}, support = {R01 AI032947/AI/NIAID NIH HHS/United States ; R21 AI076705/AI/NIAID NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; *Bacterial Physiological Phenomena ; Microbiota/*physiology ; Tick-Borne Diseases/*transmission ; Ticks/*microbiology ; }, abstract = {Ticks are obligate blood-feeders and serve as vectors of human and livestock pathogens worldwide. Defining the tick microbiome and deciphering the interactions between the tick and its symbiotic bacteria in the context of tick development and pathogen transmission will likely reveal new insights and spawn new paradigms to control tick-borne diseases. Descriptive observations on the tick microbiome that began almost a century ago serve as forerunners to the gathering momentum to define the tick microbiome in greater detail. This review will focus on the current efforts to address the microbiomes of diverse ticks, and the evolving understanding of tick microbiomes. There is hope that these efforts will bring a holistic understanding of pathogen transmission by ticks.}, }
@article {pmid25934616, year = {2015}, author = {Rohrscheib, CE and Bondy, E and Josh, P and Riegler, M and Eyles, D and van Swinderen, B and Weible, MW and Brownlie, JC}, title = {Wolbachia Influences the Production of Octopamine and Affects Drosophila Male Aggression.}, journal = {Applied and environmental microbiology}, volume = {81}, number = {14}, pages = {4573-4580}, pmid = {25934616}, issn = {1098-5336}, mesh = {Animals ; Behavior, Animal ; Drosophila Proteins/genetics/metabolism ; Drosophila melanogaster/enzymology/genetics/*microbiology/*physiology ; Female ; Male ; Mixed Function Oxygenases/genetics/metabolism ; Octopamine/*biosynthesis ; Tyrosine Decarboxylase/genetics/metabolism ; Wolbachia/*physiology ; }, abstract = {Wolbachia bacteria are endosymbionts that infect approximately 40% of all insect species and are best known for their ability to manipulate host reproductive systems. Though the effect Wolbachia infection has on somatic tissues is less well understood, when present in cells of the adult Drosophila melanogaster brain, Wolbachia exerts an influence over behaviors related to olfaction. Here, we show that a strain of Wolbachia influences male aggression in flies, which is critically important in mate competition. A specific strain of Wolbachia was observed to reduce the initiation of aggressive encounters in Drosophila males compared to the behavior of their uninfected controls. To determine how Wolbachia was able to alter aggressive behavior, we investigated the role of octopamine, a neurotransmitter known to influence male aggressive behavior in many insect species. Transcriptional analysis of the octopamine biosynthesis pathway revealed that two essential genes, the tyrosine decarboxylase and tyramine β-hydroxylase genes, were significantly downregulated in Wolbachia-infected flies. Quantitative chemical analysis also showed that total octopamine levels were significantly reduced in the adult heads.}, }
@article {pmid25933928, year = {2015}, author = {Ghosh, S and Bouvaine, S and Maruthi, MN}, title = {Prevalence and genetic diversity of endosymbiotic bacteria infecting cassava whiteflies in Africa.}, journal = {BMC microbiology}, volume = {15}, number = {}, pages = {93}, pmid = {25933928}, issn = {1471-2180}, mesh = {Africa ; Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Mitochondrial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; *Genetic Variation ; Hemiptera/*microbiology ; Manihot/parasitology ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: Cassava provides over half of the dietary requirement for more than 200 million poor in Africa. In recent years, cassava has been affected by an epidemic of a virus disease called cassava brown streak disease (CBSD) that is spreading in much of eastern and central Africa, affecting food security and the economic development of the poor. The viruses that cause CBSD are transmitted by the insect vector whitefly (Bemisia tabaci), which have increased to very high numbers in some African countries. Strains of endosymbiotic bacteria infecting whiteflies have been reported to interact specifically with different whitefly populations with varied effects on its host biology and efficiency of virus transmission. The main aim of this study was therefore to investigate the prevalence and diversity of the secondary endosymbiotic bacteria infecting cassava whiteflies with a view to better understand their role on insect population dynamics and virus disease epidemics.<br><br>RESULTS: The genetic diversity of field-collected whitefly from Tanzania, Malawi, Uganda and Nigeria was determined by mitochondrial DNA based phylogeny and restriction fragment length polymorphism. Cassava in these countries was infected with five whitefly populations, and each one was infected with different endosymbiotic bacteria. Incidences of Arsenophonus, Rickettsia, Wolbachia and Cardinium varied amongst the populations. Wolbachia was the most predominant symbiont with infection levels varying from 21 to 97%. Infection levels of Arsenophonus varied from 17 to 64% and that of Rickettsia was 0 to 53%. Hamiltonella and Fritschea were absent in all the samples. Multiple locus sequence typing identified four different strains of Wolbachia infecting cassava whiteflies. A common strain of Wolbachia infected the whitefly population Sub-Saharan Africa 1-subgroup 1 (SSA1-SG1) and SSA1-SG2, while others were infected with different strains. Phylogeny based on 16S rDNA of Rickettsia and 23S rDNA of Arsenophonus also identified distinct strains.<br><br>CONCLUSIONS: Genetically diverse bacteria infect cassava whiteflies in Africa with varied prevalence across different host populations, which may affect their whitefly biology. Further studies are required to investigate the role of endosymbionts to better understand the whitefly population dynamics.}, }
@article {pmid25924182, year = {2015}, author = {Valle, ER and Henderson, G and Janssen, PH and Cox, F and Alexander, TW and McAllister, TA}, title = {Considerations in the use of fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy to characterize rumen methanogens and define their spatial distributions.}, journal = {Canadian journal of microbiology}, volume = {61}, number = {6}, pages = {417-428}, doi = {10.1139/cjm-2014-0873}, pmid = {25924182}, issn = {1480-3275}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification/*metabolism ; Bacterial Proteins/genetics ; Cattle ; In Situ Hybridization, Fluorescence/*methods ; Methane/*metabolism ; Microscopy, Confocal/*methods ; Molecular Sequence Data ; Oxidoreductases/genetics ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rumen/*microbiology ; }, abstract = {In this study, methanogen-specific coenzyme F420 autofluorescence and confocal laser scanning microscopy were used to identify rumen methanogens and define their spatial distribution in free-living, biofilm-, and protozoa-associated microenvironments. Fluorescence in situ hybridization (FISH) with temperature-controlled hybridization was used in an attempt to describe methanogen diversity. A heat pretreatment (65 °C, 1 h) was found to be a noninvasive method to increase probe access to methanogen RNA targets. Despite efforts to optimize FISH, 16S rRNA methanogen-specific probes, including Arch915, bound to some cells that lacked F420, possibly identifying uncharacterized Methanomassiliicoccales or reflecting nonspecific binding to other members of the rumen bacterial community. A probe targeting RNA from the methanogenesis-specific methyl coenzyme M reductase (mcr) gene was shown to detect cultured Methanosarcina cells with signal intensities comparable to those of 16S rRNA probes. However, the probe failed to hybridize with the majority of F420-emitting rumen methanogens, possibly because of differences in cell wall permeability among methanogen species. Methanogens were shown to integrate into microbial biofilms and to exist as ecto- and endosymbionts with rumen protozoa. Characterizing rumen methanogens and defining their spatial distribution may provide insight into mitigation strategies for ruminal methanogenesis.}, }
@article {pmid25923352, year = {2015}, author = {Raquin, V and Valiente Moro, C and Saucereau, Y and Tran, FH and Potier, P and Mavingui, P}, title = {Native Wolbachia from Aedes albopictus Blocks Chikungunya Virus Infection In Cellulo.}, journal = {PloS one}, volume = {10}, number = {4}, pages = {e0125066}, pmid = {25923352}, issn = {1932-6203}, mesh = {Aedes/*microbiology ; Animals ; Chikungunya Fever/microbiology/*transmission/virology ; Chikungunya virus/genetics/*pathogenicity ; Humans ; Symbiosis ; Virus Replication/genetics ; Wolbachia/genetics/*pathogenicity ; }, abstract = {Wolbachia, a widespread endosymbiont of terrestrial arthropods, can protect its host against viral and parasitic infections, a phenotype called "pathogen blocking". However, in some cases Wolbachia may have no effect or even enhance pathogen infection, depending on the host-Wolbachia-pathogen combination. The tiger mosquito Aedes albopictus is naturally infected by two strains of Wolbachia, wAlbA and wAlbB, and is a competent vector for different arboviruses such as dengue virus (DENV) and chikungunya virus (CHIKV). Interestingly, it was shown in some cases that Ae. albopictus native Wolbachia strains are able to inhibit DENV transmission by limiting viral replication in salivary glands, but no such impact was measured on CHIKV replication in vivo. To better understand the Wolbachia/CHIKV/Ae. albopictus interaction, we generated a cellular model using Ae. albopictus derived C6/36 cells that we infected with the wAlbB strain. Our results indicate that CHIKV infection is negatively impacted at both RNA replication and virus assembly/secretion steps in presence of wAlbB. Using FISH, we observed CHIKV and wAlbB in the same mosquito cells, indicating that the virus is still able to enter the cell in the presence of the bacterium. Further work is needed to decipher molecular pathways involved in Wolbachia-CHIKV interaction at the cellular level, but this cellular model can be a useful tool to study the mechanism behind virus blocking phenotype induced by Wolbachia. More broadly, this put into question the ecological role of Wolbachia symbiont in Ae. albopictus, but also the ability of the CHIKV to counteract Wolbachia's antiviral potential in vivo.}, }
@article {pmid25918367, year = {2015}, author = {Frommlet, JC and Sousa, ML and Alves, A and Vieira, SI and Suggett, DJ and Serôdio, J}, title = {Coral symbiotic algae calcify ex hospite in partnership with bacteria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {19}, pages = {6158-6163}, pmid = {25918367}, issn = {1091-6490}, mesh = {Acids/chemistry ; Alcian Blue/chemistry ; Animals ; Anthozoa/*microbiology ; Anti-Bacterial Agents/chemistry ; *Bacteria ; Biofilms ; Calcium/*chemistry ; Calibration ; Dinoflagellida/*physiology ; Ecosystem ; Microscopy, Electron, Scanning ; Microscopy, Fluorescence ; Molecular Sequence Data ; Photosynthesis ; Photosystem II Protein Complex/physiology ; *Symbiosis ; Water/chemistry ; }, abstract = {Dinoflagellates of the genus Symbiodinium are commonly recognized as invertebrate endosymbionts that are of central importance for the functioning of coral reef ecosystems. However, the endosymbiotic phase within Symbiodinium life history is inherently tied to a more cryptic free-living (ex hospite) phase that remains largely unexplored. Here we show that free-living Symbiodinium spp. in culture commonly form calcifying bacterial-algal communities that produce aragonitic spherulites and encase the dinoflagellates as endolithic cells. This process is driven by Symbiodinium photosynthesis but occurs only in partnership with bacteria. Our findings not only place dinoflagellates on the map of microbial-algal organomineralization processes but also point toward an endolithic phase in the Symbiodinium life history, a phenomenon that may provide new perspectives on the biology and ecology of Symbiodinium spp. and the evolutionary history of the coral-dinoflagellate symbiosis.}, }
@article {pmid25914139, year = {2015}, author = {Gerth, M and Saeed, A and White, JA and Bleidorn, C}, title = {Extensive screen for bacterial endosymbionts reveals taxon-specific distribution patterns among bees (Hymenoptera, Anthophila).}, journal = {FEMS microbiology ecology}, volume = {91}, number = {6}, pages = {}, doi = {10.1093/femsec/fiv047}, pmid = {25914139}, issn = {1574-6941}, mesh = {Animals ; Bacteroidetes/genetics/isolation &amp; purification ; Bees/*microbiology ; Enterobacteriaceae/genetics/isolation &amp; purification ; Female ; Molecular Sequence Data ; Multilocus Sequence Typing ; Phylogeny ; Rickettsia/genetics/isolation &amp; purification ; Symbiosis/*physiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Bacterial endosymbionts play key roles in arthropod biology, ranging from beneficial mutualists to parasitic sex ratio manipulators. The number of described endosymbiotic bacterial taxa has accumulated continuously in recent years. While the understanding of arthropod-microbe interactions has advanced significantly, especially in model organisms, relatively little is known about symbiont distribution and effects in non-model organisms. As a first step to alleviate this gap in understanding, we performed an endosymbiont survey in bees (Anthophila), an ecologically and economically important group of hymenopterans. To this end, we sampled 170 bee species and screened by PCR for the presence of Wolbachia, Rickettsia, Arsenophonus and Cardinium. Detected strains were then further diagnosed by additional markers. Additionally, we tested if certain ecological traits, bee phylogeny or geographic origin of bees explain endosymbiont distribution. Our results indicate that supergroup A Wolbachia are very common in bees and that their distribution can be significantly correlated to both host ecology and phylogeny, although a distinction of these factors is not possible. Furthermore, bees from the same region (Old World or New World) are more likely to harbour identical Wolbachia strains than expected by chance. Other endosymbionts (Rickettsia, Arsenophonus) were less common, and specific to particular host taxa, suggesting that host phylogeny is a major predictor for endosymbiont distribution in bees.}, }
@article {pmid25904667, year = {2015}, author = {Weinert, LA and Araujo-Jnr, EV and Ahmed, MZ and Welch, JJ}, title = {The incidence of bacterial endosymbionts in terrestrial arthropods.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1807}, pages = {20150249}, pmid = {25904667}, issn = {1471-2954}, mesh = {Animals ; Arthropods/*microbiology ; Bacteroidetes/*physiology ; Incidence ; Likelihood Functions ; Rickettsia/*physiology ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Intracellular endosymbiotic bacteria are found in many terrestrial arthropods and have a profound influence on host biology. A basic question about these symbionts is why they infect the hosts that they do, but estimating symbiont incidence (the proportion of potential host species that are actually infected) is complicated by dynamic or low prevalence infections. We develop a maximum-likelihood approach to estimating incidence, and testing hypotheses about its variation. We apply our method to a database of screens for bacterial symbionts, containing more than 3600 distinct arthropod species and more than 150 000 individual arthropods. After accounting for sampling bias, we estimate that 52% (CIs: 48-57) of arthropod species are infected with Wolbachia, 24% (CIs: 20-42) with Rickettsia and 13% (CIs: 13-55) with Cardinium. We then show that these differences stem from the significantly reduced incidence of Rickettsia and Cardinium in most hexapod orders, which might be explained by evolutionary differences in the arthropod immune response. Finally, we test the prediction that symbiont incidence should be higher in speciose host clades. But while some groups do show a trend for more infection in species-rich families, the correlations are generally weak and inconsistent. These results argue against a major role for parasitic symbionts in driving arthropod diversification.}, }
@article {pmid25903782, year = {2015}, author = {de Azevedo-Martins, AC and Alves, JM and de Mello, FG and Vasconcelos, AT and de Souza, W and Einicker-Lamas, M and Motta, MC}, title = {Biochemical and phylogenetic analyses of phosphatidylinositol production in Angomonas deanei, an endosymbiont-harboring trypanosomatid.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {247}, pmid = {25903782}, issn = {1756-3305}, mesh = {Bacteria/isolation &amp; purification ; Gene Expression Regulation/physiology ; Phosphatidylinositols/*metabolism ; Phylogeny ; Symbiosis ; Trypanosomatina/genetics/*metabolism ; }, abstract = {BACKGROUND: The endosymbiosis in trypanosomatids is characterized by co-evolution between one bacterium and its host protozoan in a mutualistic relationship, thus constituting an excellent model to study organelle origin in the eukaryotic cell. In this association, an intense metabolic exchange is observed between both partners: the host provides energetic molecules and a stable environment to a reduced wall symbiont, while the bacterium is able to interfere in host metabolism by enhancing phospholipid production and completing essential biosynthesis pathways, such as amino acids and hemin production. The bacterium envelope presents a reduced cell wall which is mainly composed of cardiolipin and phosphatidylcholine, being the latter only common in intracellular prokaryotes. Phosphatidylinositol (PI) is also present in the symbiont and host cell membranes. This phospholipid is usually related to cellular signaling and to anchor surface molecules, which represents important events for cellular interactions.<br><br>METHODS: In order to investigate the production of PI and its derivatives in symbiont bearing trypanosomatids, aposymbiotic and wild type strains of Angomonas deanei, as well as isolated symbionts, were incubated with [(3)H]myo-inositol and the incorporation of this tracer was analyzed into inositol-containing molecules, mainly phosphoinositides and lipoproteins. Gene searches and their phylogenies were also performed in order to investigate the PI synthesis in symbiontbearing trypanosomatids.<br><br>RESULTS: Our results showed that the bacterium did not incorporate the tracer and that both strains produced similar quantities of PI and its derivatives, indicating that the symbiont does not influence the production of these metabolites. Gene searches related to PI synthesis revealed that the trypanosomatid genome contains an inositol transporter, PI synthase and the myo-inositol synthase. Thus, the host is able to produce PI either from exogenous myo-inositol (inositol transporter) or from myo-inositol synthesized de novo. Phylogenetic analysis using other organisms as references indicated that, in trypanosomatids, the genes involved in PI synthesis have a monophyletic origin. In accordance with experimental data, sequences for myo-inositol transport or for myo-inositol and PI biosynthesis were not found in the symbiont.<br><br>CONCLUSIONS: Altogether, our results indicate that the bacterium depends on the host to obtain PI.}, }
@article {pmid25902528, year = {2015}, author = {Archibald, JM}, title = {Genomic perspectives on the birth and spread of plastids.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10147-10153}, pmid = {25902528}, issn = {1091-6490}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Cell Nucleus/*genetics ; Chlorophyta/physiology ; Cyanobacteria/genetics ; Gene Transfer, Horizontal ; Genome ; *Genomics ; Mosaicism ; Photosynthesis ; Phylogeny ; Plastids/*physiology ; Symbiosis/*physiology ; }, abstract = {The endosymbiotic origin of plastids from cyanobacteria was a landmark event in the history of eukaryotic life. Subsequent to the evolution of primary plastids, photosynthesis spread from red and green algae to unrelated eukaryotes by secondary and tertiary endosymbiosis. Although the movement of cyanobacterial genes from endosymbiont to host is well studied, less is known about the migration of eukaryotic genes from one nucleus to the other in the context of serial endosymbiosis. Here I explore the magnitude and potential impact of nucleus-to-nucleus endosymbiotic gene transfer in the evolution of complex algae, and the extent to which such transfers compromise our ability to infer the deep structure of the eukaryotic tree of life. In addition to endosymbiotic gene transfer, horizontal gene transfer events occurring before, during, and after endosymbioses further confound our efforts to reconstruct the ancient mergers that forged multiple lines of photosynthetic microbial eukaryotes.}, }
@article {pmid25899011, year = {2015}, author = {Curry, MM and Paliulis, LV and Welch, KD and Harwood, JD and White, JA}, title = {Multiple endosymbiont infections and reproductive manipulations in a linyphiid spider population.}, journal = {Heredity}, volume = {115}, number = {2}, pages = {146-152}, pmid = {25899011}, issn = {1365-2540}, mesh = {Animals ; Female ; Fertility ; Male ; Phenotype ; *Rickettsia ; *Sex Ratio ; Spiders/*genetics/*microbiology ; *Symbiosis ; *Wolbachia ; }, abstract = {In many arthropods, maternally inherited endosymbiotic bacteria can increase infection frequency by manipulating host reproduction. Multiple infections of different bacteria in a single host population are common, yet few studies have documented concurrent endosymbiont phenotypes or explored their potential interactions. We hypothesized that spiders might be a particularly useful taxon for investigating endosymbiont interactions, because they are host to a plethora of endosymbiotic bacteria and frequently exhibit multiple infections. We established two matrilines from the same population of the linyphiid spider Mermessus fradeorum and then used antibiotic curing and controlled mating assays to demonstrate that each matriline was subject to a distinct endosymbiotic reproductive manipulation. One matriline was co-infected with Rickettsia and Wolbachia and produced offspring with a radical female bias. Antibiotic treatment eliminated both endosymbionts and restored an even sex ratio to subsequent generations. Chromosomal and fecundity observations suggest a feminization mechanism. In the other matriline, a separate factorial mating assay of cured and infected spiders demonstrated strong cytoplasmic incompatibility (CI) induced by a different strain of Wolbachia. However, males with this Wolbachia induced only mild CI when mated with the Rickettsia-Wolbachia females. In a subsequent survey of a field population of M. fradeorum, we detected these same three endosymbionts infecting 55% of the spiders in almost all possible combinations, with nearly half of the infected spiders exhibiting multiple infection. Our results suggest that a dynamic network of endosymbionts may interact both within multiply infected hosts and within a population subject to multiple strong reproductive manipulations.}, }
@article {pmid25889739, year = {2015}, author = {Palomar, AM and Portillo, A and Crespo, A and Santibáñez, S and Mazuelas, D and Oteo, JA}, title = {Prevalence of 'Candidatus Rickettsia vini' in Ixodes arboricola ticks in the North of Spain, 2011-2013.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {110}, pmid = {25889739}, issn = {1756-3305}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; Bird Diseases/*epidemiology/microbiology ; Birds ; DNA, Bacterial/genetics ; Female ; Ixodes/*microbiology ; Polymerase Chain Reaction/veterinary ; Prevalence ; Rickettsia/genetics/*isolation &amp; purification ; Rickettsia Infections/*epidemiology/microbiology ; Spain/epidemiology ; Symbiosis ; }, abstract = {BACKGROUND: The prevalence of Rickettsia spp. in Ixodes arboricola ticks collected from birds in two locations in the North of Spain from 2011 to 2013 was studied.<br><br>FINDINGS: The detection of the bacteria in 54 DNA extracts of I. arboricola was performed by PCR targeting an ompA fragment gene. The 94.4% of the samples yielded positive results and the nucleotide sequences were homologous (100% identity) to 'Candidatus Rickettsia vini'.<br><br>CONCLUSION: The high rate of infection suggests that 'Ca. R. vini' is a common endosymbiont of I. arboricola.}, }
@article {pmid25887945, year = {2015}, author = {Amaya-Gómez, CV and Hirsch, AM and Soto, MJ}, title = {Biofilm formation assessment in Sinorhizobium meliloti reveals interlinked control with surface motility.}, journal = {BMC microbiology}, volume = {15}, number = {}, pages = {58}, pmid = {25887945}, issn = {1471-2180}, mesh = {Biofilms/*growth &amp; development ; Environmental Microbiology ; Genes, Bacterial ; Iron/metabolism ; *Locomotion ; Medicago sativa/microbiology ; Mutation ; Plant Roots/microbiology ; Siderophores/genetics/metabolism ; Sinorhizobium meliloti/genetics/growth &amp; development/metabolism/*physiology ; }, abstract = {BACKGROUND: Swarming motility and biofilm formation are opposite, but related surface-associated behaviors that allow various pathogenic bacteria to colonize and invade their hosts. In Sinorhizobium meliloti, the alfalfa endosymbiont, these bacterial processes and their relevance for host plant colonization are largely unexplored. Our previous work demonstrated distinct swarming abilities in two S. meliloti strains (Rm1021 and GR4) and revealed that both environmental cues (iron concentration) and bacterial genes (fadD, rhb, rirA) play crucial roles in the control of surface motility in this rhizobial species. In the current study, we investigate whether these factors have an impact on the ability of S. meliloti to establish biofilms and to colonize host roots.<br><br>RESULTS: We found that strain GR4, which is less prone to translocate on solid surfaces than strain Rm1021, is more efficient in developing biofilms on glass and plant root surfaces. High iron conditions, known to prevent surface motility in a wild-type strain of S. meliloti, promote biofilm development in Rm1021 and GR4 strains by inducing the formation of more structured and thicker biofilms than those formed under low iron levels. Moreover, three different S. meliloti mutants (fadD, rhb, and rirA) that exhibit an altered surface translocation behavior compared with the wild-type strain, establish reduced biofilms on both glass and alfalfa root surfaces. Iron-rich conditions neither rescue the defect in biofilm formation shown by the rhb mutant, which is unable to produce the siderophore rhizobactin 1021 (Rhb1021), nor have any impact on biofilms formed by the iron-response regulator rirA mutant. On the other hand, S. meliloti FadD loss-of-function mutants do not establish normal biofilms irrespective of iron levels.<br><br>CONCLUSIONS: Our studies show that siderophore Rhb1021 is not only required for surface translocation, but also for biofilm formation on glass and root surfaces by strain Rm1021. In addition, we present evidence for the existence of control mechanisms that inversely regulate swarming and biofilm formation in S. meliloti, and that contribute to efficient plant root colonization. One of these mechanisms involves iron levels and the iron global regulator RirA. The other mechanism involves the participation of the fatty acid metabolism-related enzyme FadD.}, }
@article {pmid25887812, year = {2015}, author = {Rao, Q and Rollat-Farnier, PA and Zhu, DT and Santos-Garcia, D and Silva, FJ and Moya, A and Latorre, A and Klein, CC and Vavre, F and Sagot, MF and Liu, SS and Mouton, L and Wang, XW}, title = {Genome reduction and potential metabolic complementation of the dual endosymbionts in the whitefly Bemisia tabaci.}, journal = {BMC genomics}, volume = {16}, number = {1}, pages = {226}, pmid = {25887812}, issn = {1471-2164}, mesh = {Amino Acids/biosynthesis ; Animals ; DNA/analysis/isolation &amp; purification/metabolism ; Enterobacteriaceae/*genetics ; *Genome, Bacterial ; Halomonadaceae/*genetics ; Hemiptera/*genetics/metabolism/*microbiology ; High-Throughput Nucleotide Sequencing ; In Situ Hybridization, Fluorescence ; Metabolic Networks and Pathways/genetics ; Molecular Sequence Data ; Sequence Analysis, DNA ; Symbiosis/*genetics ; Vitamins/biosynthesis ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci is an important agricultural pest with global distribution. This phloem-sap feeder harbors a primary symbiont, "Candidatus Portiera aleyrodidarum", which compensates for the deficient nutritional composition of its food sources, and a variety of secondary symbionts. Interestingly, all of these secondary symbionts are found in co-localization with the primary symbiont within the same bacteriocytes, which should favor the evolution of strong interactions between symbionts.<br><br>RESULTS: In this paper, we analyzed the genome sequences of the primary symbiont Portiera and of the secondary symbiont Hamiltonella in the B. tabaci Mediterranean (MED) species in order to gain insight into the metabolic role of each symbiont in the biology of their host. The genome sequences of the uncultured symbionts Portiera and Hamiltonella were obtained from one single bacteriocyte of MED B. tabaci. As already reported, the genome of Portiera is highly reduced (357 kb), but has kept a number of genes encoding most essential amino-acids and carotenoids. On the other hand, Portiera lacks almost all the genes involved in the synthesis of vitamins and cofactors. Moreover, some pathways are incomplete, notably those involved in the synthesis of some essential amino-acids. Interestingly, the genome of Hamiltonella revealed that this secondary symbiont can not only provide vitamins and cofactors, but also complete the missing steps of some of the pathways of Portiera. In addition, some critical amino-acid biosynthetic genes are missing in the two symbiotic genomes, but analysis of whitefly transcriptome suggests that the missing steps may be performed by the whitefly itself or its microbiota.<br><br>CONCLUSIONS: These data suggest that Portiera and Hamiltonella are not only complementary but could also be mutually dependent to provide a full complement of nutrients to their host. Altogether, these results illustrate how functional redundancies can lead to gene losses in the genomes of the different symbiotic partners, reinforcing their inter-dependency.}, }
@article {pmid25887093, year = {2015}, author = {Dahan, RA and Duncan, RP and Wilson, AC and Dávalos, LM}, title = {Amino acid transporter expansions associated with the evolution of obligate endosymbiosis in sap-feeding insects (Hemiptera: sternorrhyncha).}, journal = {BMC evolutionary biology}, volume = {15}, number = {}, pages = {52}, pmid = {25887093}, issn = {1471-2148}, mesh = {Algorithms ; Amino Acid Transport Systems/*genetics/metabolism ; Animals ; Biological Evolution ; Hemiptera/*classification/cytology/*genetics/physiology ; Insect Proteins/*genetics/metabolism ; Phylogeny ; Symbiosis ; }, abstract = {BACKGROUND: Mutualistic obligate endosymbioses shape the evolution of endosymbiont genomes, but their impact on host genomes remains unclear. Insects of the sub-order Sternorrhyncha (Hemiptera) depend on bacterial endosymbionts for essential amino acids present at low abundances in their phloem-based diet. This obligate dependency has been proposed to explain why multiple amino acid transporter genes are maintained in the genomes of the insect hosts. We implemented phylogenetic comparative methods to test whether amino acid transporters have proliferated in sternorrhynchan genomes at rates grater than expected by chance.<br><br>RESULTS: By applying a series of methods to reconcile gene and species trees, inferring the size of gene families in ancestral lineages, and simulating the null process of birth and death in multi-gene families, we uncovered a 10-fold increase in duplication rate in the AAAP family of amino acid transporters within Sternorrhyncha. This gene family expansion was unmatched in other closely related clades lacking endosymbionts that provide essential amino acids.<br><br>CONCLUSIONS: Our findings support the influence of obligate endosymbioses on host genome evolution by both inferring significant expansions of gene families involved in symbiotic interactions, and discovering increases in the rate of duplication associated with multiple emergences of obligate symbiosis in Sternorrhyncha.}, }
@article {pmid25885563, year = {2015}, author = {D Ainsworth, T and Krause, L and Bridge, T and Torda, G and Raina, JB and Zakrzewski, M and Gates, RD and Padilla-Gamiño, JL and Spalding, HL and Smith, C and Woolsey, ES and Bourne, DG and Bongaerts, P and Hoegh-Guldberg, O and Leggat, W}, title = {The coral core microbiome identifies rare bacterial taxa as ubiquitous endosymbionts.}, journal = {The ISME journal}, volume = {9}, number = {10}, pages = {2261-2274}, pmid = {25885563}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*microbiology ; Bacteria/genetics/*isolation &amp; purification ; DNA, Bacterial/analysis ; Dinoflagellida/genetics ; *Microbiota/genetics ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {Despite being one of the simplest metazoans, corals harbor some of the most highly diverse and abundant microbial communities. Differentiating core, symbiotic bacteria from this diverse host-associated consortium is essential for characterizing the functional contributions of bacteria but has not been possible yet. Here we characterize the coral core microbiome and demonstrate clear phylogenetic and functional divisions between the micro-scale, niche habitats within the coral host. In doing so, we discover seven distinct bacterial phylotypes that are universal to the core microbiome of coral species, separated by thousands of kilometres of oceans. The two most abundant phylotypes are co-localized specifically with the corals' endosymbiotic algae and symbiont-containing host cells. These bacterial symbioses likely facilitate the success of the dinoflagellate endosymbiosis with corals in diverse environmental regimes.}, }
@article {pmid25884672, year = {2015}, author = {Otranto, D and Giannelli, A and Scotty Trumble, N and Chavkin, M and Kennard, G and Latrofa, MS and Bowman, DD and Dantas-Torres, F and Eberhard, ML}, title = {Clinical case presentation and a review of the literature of canine onchocercosis by Onchocerca lupi in the United States.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {89}, pmid = {25884672}, issn = {1756-3305}, mesh = {Animals ; Dog Diseases/*diagnosis/parasitology/therapy ; Dogs ; Eye/parasitology ; Female ; Male ; Onchocerca/*physiology ; Onchocerciasis/diagnosis/parasitology/therapy/*veterinary ; United States ; }, abstract = {BACKGROUND: Onchocerca lupi, a filarioid of zoonotic concern, infects dogs and cats causing ocular lesions of different degrees, from minor to severe. However, infected animals do not always display overt clinical signs, rendering the diagnosis of the infection obscure to the majority of veterinarians. Canine onchocercosis has been reported in the Old World and the information on its occurrence in the United States, as well as its pathogenesis and clinical management is still meagre. This study reports on the largest case series of O. lupi infection from the United States and reviews previous cases of canine onchocercosis in this country.<br><br>METHODS: Information on the clinical history of a series of eight cases of O. lupi infection in dogs diagnosed in Minnesota, New Mexico, Colorado and Florida, from 2011 to 2014, was obtained from clinical records provided the veterinary practitioners. Nematodes were morphologically identified at species level and genetically analyzed.<br><br>RESULTS: All dogs displayed a similar clinical presentation, including subconjunctival and episcleral nodules, which were surgically removed. Each dog was subjected to post-operative therapy. Whitish filaria-like parasites were morphologically and molecularly identified as O. lupi.<br><br>CONCLUSIONS: This study confirms that O. lupi is endemic in the United States, indicating that the distribution of the infection is probably wider than previously thought. With effect, further studies are urgently needed in order to improve the diagnosis and to assess the efficacy of therapeutic protocols, targeting the parasite itself and/or its endosymbionts.}, }
@article {pmid25884425, year = {2015}, author = {Hii, SF and Lawrence, AL and Cuttell, L and Tynas, R and Abd Rani, PA and Šlapeta, J and Traub, RJ}, title = {Evidence for a specific host-endosymbiont relationship between 'Rickettsia sp. genotype RF2125' and Ctenocephalides felis orientis infesting dogs in India.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {169}, pmid = {25884425}, issn = {1756-3305}, mesh = {Animals ; Base Sequence ; Ctenocephalides/classification/*microbiology ; DNA, Bacterial/chemistry/genetics ; Dog Diseases/*microbiology/parasitology ; Dogs ; Female ; Flea Infestations/*veterinary ; Genotype ; India/epidemiology ; Male ; Molecular Sequence Data ; Phylogeny ; Rickettsia/genetics/*physiology ; Rickettsia Infections/microbiology/*veterinary ; Rickettsia felis/genetics/physiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {BACKGROUND: Fleas of the genus Ctenocephalides serve as vectors for a number of rickettsial zoonoses, including Rickettsia felis. There are currently no published reports of the presence and distribution of R. felis in India, however, the ubiquitous distribution of its vector Ctenocephalides felis, makes it possible that the pathogen is endemic to the region. This study investigates the occurrence of Rickettsia spp. infection in various subspecies of C. felis infesting dogs from urban areas of Mumbai, Delhi and Rajasthan in India.<br><br>METHODS: Individual fleas collected off 77 stray dogs from Mumbai, Delhi and Rajasthan were screened for Rickettsia spp. by a conventional PCR targeting the ompB gene. Further genetic characterisation of Rickettsia-positive fleas was carried out using nested PCR and phylogenetic analysis of partial DNA sequences of the gltA and ompA genes. Ctenocephalides spp. were morphologically and genetically identified by PCR targeting a fragment of cox1 gene.<br><br>RESULTS: Overall, 56/77 fleas (72.7%), including 22/24 (91.7%) from Delhi, 32/44 (72.7%) from Mumbai and 2/9 (22.2%) from Rajasthan were positive for Rickettsia DNA at the ompB gene. Sequences of gltA fragments confirmed the amplification of Rickettsia sp. genotype RF2125. The ompA gene of Rickettsia sp. genotype RF2125 was characterised for the first time and shown 96% identical to R. felis. Three species of Ctenocephalides were identified, with the Ctenocephalides felis orientis being the dominant flea species (69/77; 89.6%) in India, followed by Ctenocephalides felis felis (8/77; 10.4%).<br><br>CONCLUSIONS: High occurrence of Rickettsia sp. genotype RF2125 in C. felis orientis and the absence of R. felis suggests a specific vector-endosymbiont adaptation and coevolution of the Rickettsia felis-like sp. within subspecies of C. felis.}, }
@article {pmid25880387, year = {2015}, author = {Nguyen, DT and Spooner-Hart, RN and Riegler, M}, title = {Polyploidy versus endosymbionts in obligately thelytokous thrips.}, journal = {BMC evolutionary biology}, volume = {15}, number = {}, pages = {23}, pmid = {25880387}, issn = {1471-2148}, mesh = {Animals ; Cell Nucleus/genetics ; Female ; Genetic Variation ; Male ; Mitochondria/genetics ; *Parthenogenesis ; Phylogeny ; Polymerase Chain Reaction ; *Polyploidy ; Symbiosis ; Thysanoptera/classification/*genetics/*microbiology/physiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {BACKGROUND: Thelytoky, the parthenogenetic development of females, has independently evolved in several insect orders yet the study of its mechanisms has so far mostly focussed on haplodiploid Hymenoptera, while alternative mechanisms of thelytoky such as polyploidy are far less understood. In haplodiploid insects, thelytoky can be encoded in their genomes, or induced by maternally inherited bacteria such as Wolbachia or Cardinium. Microbially facilitated thelytoky usually results in complete homozygosity due to gamete duplication and can be reverted into arrhenotoky, the parthenogenetic development of males, through treatment with antibiotics. In contrast, genetically encoded thelytoky cannot be removed and may result in conservation of heterozygosity due to gamete fusion. We have probed the obligate thelytoky of the greenhouse thrips, Heliothrips haemorrhoidalis (Bouché), a significant cosmopolitan pest and a model species of thelytoky in the haplodiploid insect order Thysanoptera. Earlier studies suggested terminal fusion as a mechanism for thelytoky in this species, while another study reported presence of Wolbachia; later it was speculated that Wolbachia plays a role in this thrips' thelytokous reproduction.<br><br>RESULTS: By using PCR and sequence analysis, we demonstrated that global population samples of H. haemorrhoidalis were not infected with Wolbachia, Cardinium or any other known bacterial reproductive manipulators. Antibiotic treatment of this thrips did also not result in male production. Some individuals carried two different alleles in two nuclear loci, histone 3 and elongation factor 1 alpha, suggesting heterozygosity. However, the majority of individuals had three different alleles suggesting that they were polyploid. Genetic diversity across both nuclear loci was low in all populations, and absent from mitochondrial cytochrome oxidase I, indicating that this species had experienced genetic bottlenecks, perhaps due to its invasion biology or a switch to thelytoky.<br><br>CONCLUSIONS: Geographically broad sampling and experimental manipulation revealed low genetic diversity, absence of Wolbachia but presence of three different alleles of nuclear loci in most analysed individuals of obligately thelytokous H. haemorrhoidalis. This suggests that polyploidy may be involved in the thelytokous reproduction of this thrips species, and polyploidy may be a contributing factor in the reproduction of Thysanoptera and other haplodiploid insect orders.}, }
@article {pmid25870270, year = {2015}, author = {Perlman, SJ and Hodson, CN and Hamilton, PT and Opit, GP and Gowen, BE}, title = {Maternal transmission, sex ratio distortion, and mitochondria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10162-10168}, pmid = {25870270}, issn = {1091-6490}, mesh = {Animals ; Arthropods/microbiology ; Bacteria/genetics ; Base Sequence ; Cell Nucleus/genetics ; DNA Barcoding, Taxonomic ; Electron Transport Complex IV/metabolism ; Female ; Haplotypes ; *Inheritance Patterns ; Insecta/microbiology ; Male ; Mitochondria/*genetics ; Molecular Sequence Data ; *Polymorphism, Genetic ; Sequence Analysis, DNA ; *Sex Ratio ; Symbiosis ; Wolbachia/physiology ; }, abstract = {In virtually all multicellular eukaryotes, mitochondria are transmitted exclusively through one parent, usually the mother. In this short review, we discuss some of the major consequences of uniparental transmission of mitochondria, including deleterious effects in males and selection for increased transmission through females. Many of these consequences, particularly sex ratio distortion, have well-studied parallels in other maternally transmitted genetic elements, such as bacterial endosymbionts of arthropods. We also discuss the consequences of linkage between mitochondria and other maternally transmitted genetic elements, including the role of cytonuclear incompatibilities in maintaining polymorphism. Finally, as a case study, we discuss a recently discovered maternally transmitted sex ratio distortion in an insect that is associated with extraordinarily divergent mitochondria.}, }
@article {pmid25869035, year = {2015}, author = {Ogrzewalska, M and Literák, I and Capek, M and Sychra, O and Calderón, V&#xc1; and Rodríguez, BC and Prudencio, C and Martins, TF and Labruna, MB}, title = {Bacteria of the genus Rickettsia in ticks (Acari: Ixodidae) collected from birds in Costa Rica.}, journal = {Ticks and tick-borne diseases}, volume = {6}, number = {4}, pages = {478-482}, doi = {10.1016/j.ttbdis.2015.03.016}, pmid = {25869035}, issn = {1877-9603}, mesh = {Animals ; Animals, Wild/parasitology ; Bird Diseases/*parasitology ; Birds ; Costa Rica ; Ixodidae/classification/genetics/growth &amp; development/*microbiology ; Larva/classification/genetics/growth &amp; development/microbiology ; Rickettsia/classification/genetics/*isolation &amp; purification ; Tick Infestations/parasitology/*veterinary ; }, abstract = {The aim of this study was to document the presence of Rickettsia spp. in ticks parasitizing wild birds in Costa Rica. Birds were trapped at seven locations in Costa Rica during 2004, 2009, and 2010; then visually examined for the presence of ticks. Ticks were identified, and part of them was tested individually for the presence of Rickettsia spp. by polymerase chain reaction (PCR) using primers targeting fragments of the rickettsial genes gltA and ompA. PCR products were DNA-sequenced and analyzed in BLAST to determine similarities with previously reported rickettsial agents. A total of 1878 birds were examined, from which 163 birds (9%) were infested with 388 ticks of the genera Amblyomma and Ixodes. The following Amblyomma (in decreasing order of abundance) were found in immature stages (larvae and nymphs): Amblyomma longirostre, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma sabanerae, Amblyomma varium, Amblyomma maculatum, and Amblyomma ovale. Ixodes ticks were represented by Ixodes minor and two unclassified species, designated here as Ixodes sp. genotype I, and Ixodes sp. genotype II. Twelve of 24 tested A. longirostre ticks were found to be infected with 'Candidatus Rickettsia amblyommii', and 2 of 4 A. sabanerae were found to be infected with Rickettsia bellii. Eight of 10 larval Ixodes minor were infected with an endosymbiont (a novel Rickettsia sp. agent) genetically related to the Ixodes scapularis endosymbiont. No rickettsial DNA was found in A. calcaratum, A. coelebs, A. maculatum, A. ovale, A. varium, Ixodes sp. I, and Ixodes sp. II. We report the occurrence of I. minor in Costa Rica for the first time and a number of new bird host-tick associations. Moreover, 'Candidatus R. amblyommii' and R. bellii were found in A. longirostre and A. sabanerae, respectively, in Costa Rica for the first time.}, }
@article {pmid25866055, year = {2015}, author = {Wernegreen, JJ}, title = {Endosymbiont evolution: predictions from theory and surprises from genomes.}, journal = {Annals of the New York Academy of Sciences}, volume = {1360}, number = {1}, pages = {16-35}, pmid = {25866055}, issn = {1749-6632}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Evolution, Molecular ; Forecasting ; Genome/*physiology ; Genome, Bacterial/physiology ; Humans ; Selection, Genetic/*physiology ; Symbiosis/*physiology ; }, abstract = {Genome data have created new opportunities to untangle evolutionary processes shaping microbial variation. Among bacteria, long-term mutualists of insects represent the smallest and (typically) most AT-rich genomes. Evolutionary theory provides a context to predict how an endosymbiotic lifestyle may alter fundamental evolutionary processes--mutation, selection, genetic drift, and recombination--and thus contribute to extreme genomic outcomes. These predictions can then be explored by comparing evolutionary rates, genome size and stability, and base compositional biases across endosymbiotic and free-living bacteria. Recent surprises from such comparisons include genome reduction among uncultured, free-living species. Some studies suggest that selection generally drives this streamlining, while drift drives genome reduction in endosymbionts; however, this remains an hypothesis requiring additional data. Unexpected evidence of selection acting on endosymbiont GC content hints that even weak selection may be effective in some long-term mutualists. Moving forward, intraspecific analysis offers a promising approach to distinguish underlying mechanisms, by testing the null hypothesis of neutrality and by quantifying mutational spectra. Such analyses may clarify whether endosymbionts and free-living bacteria occupy distinct evolutionary trajectories or, alternatively, represent varied outcomes of similar underlying forces.}, }
@article {pmid25861561, year = {2015}, author = {Williams, LE and Wernegreen, JJ}, title = {Genome evolution in an ancient bacteria-ant symbiosis: parallel gene loss among Blochmannia spanning the origin of the ant tribe Camponotini.}, journal = {PeerJ}, volume = {3}, number = {}, pages = {e881}, pmid = {25861561}, issn = {2167-8359}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; }, abstract = {Stable associations between bacterial endosymbionts and insect hosts provide opportunities to explore genome evolution in the context of established mutualisms and assess the roles of selection and genetic drift across host lineages and habitats. Blochmannia, obligate endosymbionts of ants of the tribe Camponotini, have coevolved with their ant hosts for ∼40 MY. To investigate early events in Blochmannia genome evolution across this ant host tribe, we sequenced Blochmannia from two divergent host lineages, Colobopsis obliquus and Polyrhachis turneri, and compared them with four published genomes from Blochmannia of Camponotus sensu stricto. Reconstructed gene content of the last common ancestor (LCA) of these six Blochmannia genomes is reduced (690 protein coding genes), consistent with rapid gene loss soon after establishment of the symbiosis. Differential gene loss among Blochmannia lineages has affected cellular functions and metabolic pathways, including DNA replication and repair, vitamin biosynthesis and membrane proteins. Blochmannia of P. turneri (i.e., B. turneri) encodes an intact DnaA chromosomal replication initiation protein, demonstrating that loss of dnaA was not essential for establishment of the symbiosis. Based on gene content, B. obliquus and B. turneri are unable to provision hosts with riboflavin. Of the six sequenced Blochmannia, B. obliquus is the earliest diverging lineage (i.e., the sister group of other Blochmannia sampled) and encodes the fewest protein-coding genes and the most pseudogenes. We identified 55 genes involved in parallel gene loss, including glutamine synthetase, which may participate in nitrogen recycling. Pathways for biosynthesis of coenzyme A, terpenoids and riboflavin were lost in multiple lineages, suggesting relaxed selection on the pathway after inactivation of one component. Analysis of Illumina read datasets did not detect evidence of plasmids encoding missing functions, nor the presence of coresident symbionts other than Wolbachia. Although gene order is strictly conserved in four Blochmannia of Camponotus sensu stricto, comparisons with deeply divergent lineages revealed inversions in eight genomic regions, indicating ongoing recombination despite ancestral loss of recA. In sum, the addition of two Blochmannia genomes of divergent host lineages enables reconstruction of early events in evolution of this symbiosis and suggests that Blochmannia lineages may experience distinct, host-associated selective pressures. Understanding how evolutionary forces shape genome reduction in this system may help to clarify forces driving gene loss in other bacteria, including intracellular pathogens.}, }
@article {pmid25852067, year = {2015}, author = {Nissen, M and Shcherbakov, D and Heyer, A and Brümmer, F and Schill, RO}, title = {Behaviour of the plathelminth Symsagittifera roscoffensis under different light conditions and the consequences for the symbiotic algae Tetraselmis convolutae.}, journal = {The Journal of experimental biology}, volume = {218}, number = {Pt 11}, pages = {1693-1698}, doi = {10.1242/jeb.110429}, pmid = {25852067}, issn = {1477-9145}, mesh = {Animals ; Chlorophyta/physiology/*radiation effects ; *Light ; Movement/radiation effects ; Photosynthesis ; Platyhelminths/physiology/*radiation effects ; Symbiosis ; }, abstract = {Symsagittifera roscoffensis is a plathelminth living in symbiosis with the green algae Tetraselmis convolutae. Host and symbiont are a model system for the study of endosymbiosis, which has so far mainly focused on their biochemical interactions. Symsagittifera roscoffensis is well known for its positive phototaxis that is hypothesized to optimize the symbiont's light perception for photosynthesis. In this study, we conducted a detailed analysis of phototaxis using light sources of different wavelength and brightness by videotracking. Furthermore, we compared the behavioural data with the electron transfer rate of the photosystem from cultured symbiotic cells. The symbiotic algae is adapted to low light conditions, showing a positive electron transfer rate at a photosynthetically active radiation of 0.112 µmol photons m(-2) s(-1), and S. roscoffensis showed a positive phototactic behaviour for light intensities up to 459.17 µmol photons m(-2) s(-1), which is not optimal regarding the needs of the symbiotic cells and may even harm host and symbiont. Red light cannot be detected by the animals and therefore their eyes seem not to be suitable for measuring the exact photosynthetically active radiation to the benefit of the photosymbionts.}, }
@article {pmid25848019, year = {2015}, author = {Gray, MW}, title = {Mosaic nature of the mitochondrial proteome: Implications for the origin and evolution of mitochondria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10133-10138}, pmid = {25848019}, issn = {1091-6490}, mesh = {Alphaproteobacteria/*physiology ; Animals ; Biological Evolution ; DNA, Mitochondrial/physiology ; Evolution, Molecular ; Gene Transfer Techniques ; Genome, Mitochondrial ; Humans ; Mice ; Mitochondria/*physiology ; Mitochondrial Proteins/*physiology ; Phylogeny ; *Proteome ; Symbiosis ; Yeasts ; }, abstract = {Comparative studies of the mitochondrial proteome have identified a conserved core of proteins descended from the α-proteobacterial endosymbiont that gave rise to the mitochondrion and was the source of the mitochondrial genome in contemporary eukaryotes. A surprising result of phylogenetic analyses is the relatively small proportion (10-20%) of the mitochondrial proteome displaying a clear α-proteobacterial ancestry. A large fraction of mitochondrial proteins typically has detectable homologs only in other eukaryotes and is presumed to represent proteins that emerged specifically within eukaryotes. A further significant fraction of the mitochondrial proteome consists of proteins with homologs in prokaryotes, but without a robust phylogenetic signal affiliating them with specific prokaryotic lineages. The presumptive evolutionary source of these proteins is quite different in contending models of mitochondrial origin.}, }
@article {pmid25847197, year = {2015}, author = {Rynkiewicz, EC and Hemmerich, C and Rusch, DB and Fuqua, C and Clay, K}, title = {Concordance of bacterial communities of two tick species and blood of their shared rodent host.}, journal = {Molecular ecology}, volume = {24}, number = {10}, pages = {2566-2579}, doi = {10.1111/mec.13187}, pmid = {25847197}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification/isolation &amp; purification ; DNA, Bacterial/genetics ; Dermacentor/*microbiology ; Indiana ; Ixodes/*microbiology ; Larva ; *Microbiota ; Nymph ; Peromyscus/blood/*microbiology/parasitology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {High-throughput sequencing is revealing that most macro-organisms house diverse microbial communities. Of particular interest are disease vectors whose microbiome could potentially affect pathogen transmission and vector competence. We investigated bacterial community composition and diversity of the ticks Dermacentor variabilis (n = 68) and Ixodes scapularis (n = 15) and blood of their shared rodent host, Peromyscus leucopus (n = 45) to quantify bacterial diversity and concordance. The 16S rRNA gene was amplified from genomic DNA from field-collected tick and rodent blood samples, and 454 pyrosequencing was used to elucidate their bacterial communities. After quality control, over 300 000 sequences were obtained and classified into 118 operational taxonomic units (OTUs, clustered at 97% similarity). Analysis of rarefied communities revealed that the most abundant OTUs were tick species-specific endosymbionts, Francisella and Rickettsia, and the commonly flea-associated bacterium Bartonella in rodent blood. An Arsenophonus and additional Francisella endosymbiont were also present in D. variabilis samples. Rickettsia was found in both tick species but not in rodent blood, suggesting that it is not transmitted during feeding. Bartonella was present in larvae and nymphs of both tick species, even those scored as unengorged. Relatively, few OTUs (e.g. Bartonella, Lactobacillus) were found in all sample types. Overall, bacterial communities from each sample type were significantly different and highly structured, independent of their dominant OTUs. Our results point to complex microbial assemblages inhabiting ticks and host blood including infectious agents, tick-specific endosymbionts and environmental bacteria that could potentially affect arthropod-vectored disease dynamics.}, }
@article {pmid25845868, year = {2015}, author = {Shrivastava, N and Nag, JK and Pandey, J and Tripathi, RP and Shah, P and Siddiqi, MI and Misra-Bhattacharya, S}, title = {Homology modeling of NAD+-dependent DNA ligase of the Wolbachia endosymbiont of Brugia malayi and its drug target potential using dispiro-cycloalkanones.}, journal = {Antimicrobial agents and chemotherapy}, volume = {59}, number = {7}, pages = {3736-3747}, pmid = {25845868}, issn = {1098-6596}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Brugia malayi/*microbiology ; DNA Ligase ATP ; DNA Ligases/*antagonists &amp; inhibitors/drug effects ; Escherichia coli/genetics/metabolism ; Filaricides/*pharmacology ; Gerbillinae ; Ketones/chemical synthesis/*pharmacology ; Male ; Microbial Sensitivity Tests ; Models, Molecular ; Molecular Docking Simulation ; Murinae/parasitology ; Spiro Compounds/chemical synthesis/*pharmacology ; Symbiosis ; Wolbachia/*drug effects/enzymology ; }, abstract = {Lymphatic filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility, and viability and thus has great promise as a novel approach for treating filarial diseases. NAD(+)-dependent DNA ligase is an essential enzyme of DNA replication, repair, and recombination. Therefore, in the present study, the antifilarial drug target potential of the NAD(+)-dependent DNA ligase of the Wolbachia symbiont of Brugia malayi (wBm-LigA) was investigated using dispiro-cycloalkanone compounds. Dispiro-cycloalkanone specifically inhibited the nick-closing and cohesive-end ligation activities of the enzyme without inhibiting human or T4 DNA ligase. The mode of inhibition was competitive with the NAD(+) cofactor. Docking studies also revealed the interaction of these compounds with the active site of the target enzyme. The adverse effects of these inhibitors were observed on adult and microfilarial stages of B. malayi in vitro, and the most active compounds were further monitored in vivo in jirds and mastomys rodent models. Compounds 1, 2, and 5 had severe adverse effects in vitro on the motility of both adult worms and microfilariae at low concentrations. Compound 2 was the best inhibitor, with the lowest 50% inhibitory concentration (IC50) (1.02 μM), followed by compound 5 (IC50, 2.3 μM) and compound 1 (IC50, 2.9 μM). These compounds also exhibited the same adverse effect on adult worms and microfilariae in vivo (P < 0.05). These compounds also tremendously reduced the wolbachial load, as evident by quantitative real-time PCR (P < 0.05). wBm-LigA thus shows great promise as an antifilarial drug target, and dispiro-cycloalkanone compounds show great promise as antifilarial lead candidates.}, }
@article {pmid25845267, year = {2015}, author = {Cassone, BJ and Redinbaugh, MG and Dorrance, AE and Michel, AP}, title = {Shifts in Buchnera aphidicola density in soybean aphids (Aphis glycines) feeding on virus-infected soybean.}, journal = {Insect molecular biology}, volume = {24}, number = {4}, pages = {422-431}, doi = {10.1111/imb.12170}, pmid = {25845267}, issn = {1365-2583}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/genetics/*virology ; Comovirus/*physiology ; Fertility ; Genes, Bacterial ; Host-Pathogen Interactions ; *Mosaic Viruses ; Plant Diseases/virology ; Population Dynamics ; Soybeans/parasitology/*virology ; Symbiosis ; Transcriptome ; }, abstract = {Vertically transmitted bacterial symbionts are common in arthropods. Aphids undergo an obligate symbiosis with Buchnera aphidicola, which provides essential amino acids to its host and contributes directly to nymph growth and reproduction. We previously found that newly adult Aphis glycines feeding on soybean infected with the beetle-transmitted Bean pod mottle virus (BPMV) had significantly reduced fecundity. We hypothesized that the reduced fecundity was attributable to detrimental impacts of the virus on the aphid microbiome, namely Buchnera. To test this, mRNA sequencing and quantitative real-time PCR were used to assay Buchnera transcript abundance and titre in A. glycines feeding on Soybean mosaic virus-infected, BPMV-infected, and healthy soybean for up to 14 days. Our results indicated that Buchnera density was lower and ultimately suppressed in aphids feeding on virus-infected soybean. While the decreased Buchnera titre may be associated with reduced aphid fecundity, additional mechanisms are probably involved. The present report begins to describe how interactions among insects, plants, and plant pathogens influence endosymbiont population dynamics.}, }
@article {pmid25843551, year = {2015}, author = {Luévano-Martínez, LA}, title = {The chimeric origin of the cardiolipin biosynthetic pathway in the Eukarya domain.}, journal = {Biochimica et biophysica acta}, volume = {1847}, number = {6-7}, pages = {599-606}, doi = {10.1016/j.bbabio.2015.03.005}, pmid = {25843551}, issn = {0006-3002}, mesh = {Archaea/classification/genetics/*metabolism ; Bacteria/classification/genetics/*metabolism ; *Biological Evolution ; *Biosynthetic Pathways ; Cardiolipins/genetics/*metabolism ; Eukaryota/classification/genetics/*metabolism ; *Phylogeny ; Protein Structure, Tertiary ; Proteins/genetics/metabolism ; Symbiosis ; }, abstract = {Cardiolipin (CL) and phosphatidylglycerol (PG) are the main anionic phospholipids present in the Eukarya and Bacteria domains. They participate in energy transduction by activating and stabilizing the components of the oxidative phosphorylation machinery. Experimental evidence shows that they are synthesized by two different mechanisms which indicate that both pathways evolved convergently. Former studies on the lipid composition of archaeal membranes showed the absence of CL in these organisms, consequently, restricting it to the Eukarya and Bacteria domains. Interestingly, recent studies have demonstrated that both CL and PG are present as constitutive components of membranes of the haloarchaea group. However, this scenario complicates the analysis of the evolutionary origin of this biosynthetic pathway. Here I suggest that a phospholipid biosynthetic pathway in Eukarya probably arose from a chimeric event between bacterial and archaeal enzymes during the endosymbiosis event. Phylogenetic analyses support the different evolutionary origin of the enzymes comprising this pathway in bacteria and Eukarya. Based on protein domain analyses, orthologous proteins in the Archaea domain were identified. An integrative analysis of the proteins found demonstrates that CL biosynthesis in major clades of the Eukarya domain originated by chimerism between the bacteria and archaea pathways. Moreover, primary and secondary endosymbiontic events in plants and chromoalveolata respectively, reshaped this pathway again. The implications and advantages that these new enzymatic orders conferred to the Eukarya domain are discussed.}, }
@article {pmid25842897, year = {2014}, author = {Kizilova, AK and Kravchenko, IK}, title = {Diversity of diazotrophic gut inhabitants of pikas (Ochotonidae) revealed by PCR-DGGE analysis.}, journal = {Mikrobiologiia}, volume = {83}, number = {3}, pages = {366-374}, doi = {10.7868/s0026365614010066}, pmid = {25842897}, issn = {0026-3656}, mesh = {Animals ; Bacteria/*genetics/metabolism ; Biodiversity ; Bradyrhizobium/genetics ; Denaturing Gradient Gel Electrophoresis ; Evolution, Molecular ; Female ; Gastrointestinal Tract/*microbiology ; Lagomorpha/*microbiology ; Male ; Molecular Sequence Data ; Nitrogen Fixation ; Oxidoreductases/*genetics ; *Phylogeny ; Polymerase Chain Reaction/methods ; Sphingomonas/genetics ; Symbiosis ; }, abstract = {Diazotrophic gut symbionts are considered to act as nitrogen providers for their hosts, as was shown for various termite species. Although the diet of lagomorphs, like pikas or rabbits, is very poor in nitrogen and energy, their fecal matter contains 30-40% of protein. Since our hypothesis was that pikas maintained a diazotrophic consortium in their gastrointestinal tract, we conducted the first investigation of microbial diversity in pika guts. We obtained gut samples from animals of several Ochotona species, O. hyperborea (Northern pika), O. mantchurica (Manchurian pika), and O. dauurica (Daurian pika), in order to retrieve and compare the nitrogen-fixing communities of different pika species. The age and gender of the animals were taken into consideration. We amplified 320-bp long fragments of the nifH gene using the DNA extracted directly from the colon and cecum samples of pika's gut, resolved them by DGGE, and performed phylogenetic reconstruction of 51 sequences obtained from excised bands. No significant difference was detected between the nitrogen-fixing gut inhabitants of different pika species. NifH sequences fell into two clusters. The first cluster contained the sequences affiliated with NifH Cluster I (Zehr et al., 2003) with similarity to Sphingomonas sp., Bradyrhizobium sp., and various uncultured bacteria from soil and rhizosphere. Sequences from the second group were related to Treponema sp., Fibrobacter succinogenes, and uncultured clones from the guts of various termites and belonged to NifH Cluster III. We suggest that diazotrophic organisms from the second cluster are genuine endosymbionts of pikas and provide nitrogen for further synthesis processes thus allowing these animals not to be short of protein.}, }
@article {pmid25840416, year = {2015}, author = {Kamikawa, R and Tanifuji, G and Kawachi, M and Miyashita, H and Hashimoto, T and Inagaki, Y}, title = {Plastid genome-based phylogeny pinpointed the origin of the green-colored plastid in the dinoflagellate Lepidodinium chlorophorum.}, journal = {Genome biology and evolution}, volume = {7}, number = {4}, pages = {1133-1140}, pmid = {25840416}, issn = {1759-6653}, mesh = {Dinoflagellida/classification/*genetics ; *Evolution, Molecular ; *Genome, Plastid ; Molecular Sequence Data ; *Phylogeny ; Plastids/genetics ; }, abstract = {Unlike many other photosynthetic dinoflagellates, whose plastids contain a characteristic carotenoid peridinin, members of the genus Lepidodinium are the only known dinoflagellate species possessing green alga-derived plastids. However, the precise origin of Lepidodinium plastids has hitherto remained uncertain. In this study, we completely sequenced the plastid genome of Lepidodinium chlorophorum NIES-1868. Our phylogenetic analyses of 52 plastid-encoded proteins unite L. chlorophorum exclusively with a pedinophyte, Pedinomonas minor, indicating that the green-colored plastids in Lepidodinium spp. were derived from an endosymbiotic pedinophyte or a green alga closely related to pedinophytes. Our genome comparison incorporating the origin of the Lepidodinium plastids strongly suggests that the endosymbiont plastid genome acquired by the ancestral Lepidodinium species has lost genes encoding proteins involved in metabolism and biosynthesis, protein/metabolite transport, and plastid division during the endosymbiosis. We further discuss the commonalities and idiosyncrasies in genome evolution between the L. chlorophorum plastid and other plastids acquired through endosymbiosis of eukaryotic photoautotrophs.}, }
@article {pmid25831547, year = {2015}, author = {Leger, MM and Petrů, M and Žárský, V and Eme, L and Vlček, &#x10c; and Harding, T and Lang, BF and Eliáš, M and Doležal, P and Roger, AJ}, title = {An ancestral bacterial division system is widespread in eukaryotic mitochondria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10239-10246}, pmid = {25831547}, issn = {1091-6490}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Adenosine Triphosphatases/metabolism ; Arabidopsis/genetics ; Bacteria/cytology ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; Cell Cycle Proteins/metabolism ; Cell Division ; Cytoskeletal Proteins/*genetics ; DNA, Bacterial/*genetics ; Databases, Genetic ; Dictyostelium/metabolism ; Escherichia coli Proteins/metabolism ; Evolution, Molecular ; Likelihood Functions ; Mitochondria/*metabolism ; *Mitochondrial Dynamics ; Molecular Sequence Data ; Phylogeny ; Plastids/metabolism ; Saccharomyces cerevisiae/genetics/metabolism ; }, abstract = {Bacterial division initiates at the site of a contractile Z-ring composed of polymerized FtsZ. The location of the Z-ring in the cell is controlled by a system of three mutually antagonistic proteins, MinC, MinD, and MinE. Plastid division is also known to be dependent on homologs of these proteins, derived from the ancestral cyanobacterial endosymbiont that gave rise to plastids. In contrast, the mitochondria of model systems such as Saccharomyces cerevisiae, mammals, and Arabidopsis thaliana seem to have replaced the ancestral α-proteobacterial Min-based division machinery with host-derived dynamin-related proteins that form outer contractile rings. Here, we show that the mitochondrial division system of these model organisms is the exception, rather than the rule, for eukaryotes. We describe endosymbiont-derived, bacterial-like division systems comprising FtsZ and Min proteins in diverse less-studied eukaryote protistan lineages, including jakobid and heterolobosean excavates, a malawimonad, stramenopiles, amoebozoans, a breviate, and an apusomonad. For two of these taxa, the amoebozoan Dictyostelium purpureum and the jakobid Andalucia incarcerata, we confirm a mitochondrial localization of these proteins by their heterologous expression in Saccharomyces cerevisiae. The discovery of a proteobacterial-like division system in mitochondria of diverse eukaryotic lineages suggests that it was the ancestral feature of all eukaryotic mitochondria and has been supplanted by a host-derived system multiple times in distinct eukaryote lineages.}, }
@article {pmid25829258, year = {2015}, author = {Gegner, T and Otti, O and Tragust, S and Feldhaar, H}, title = {Do microsporidia function as "biological weapon" for Harmonia axyridis under natural conditions?.}, journal = {Insect science}, volume = {22}, number = {3}, pages = {353-359}, doi = {10.1111/1744-7917.12224}, pmid = {25829258}, issn = {1744-7917}, mesh = {Animals ; Coleoptera/*microbiology ; Hemolymph/microbiology ; *Introduced Species ; Larva/microbiology ; Microsporidia/physiology ; Predatory Behavior ; Symbiosis ; }, abstract = {Invasive alien species, such as the multicoloured Asian ladybird Harmonia axyridis, are often regarded as major drivers of biodiversity loss. Therefore understanding which characteristics or mechanisms contribute to their invasive success is important. Here the role of symbiotic microsporidia in the hemolymph of H. axyridis was investigated in the context of intraguild predation between wild-caught H. axyridis and the native ladybird species Coccinella septempunctata. The microsporidia were recently discussed to contribute to the unpalatability of Harmonia for other coccinellids during intraguild predation and to function as "biological weapons". In the present study, visual detection of microsporidia in hemolymph samples revealed that 73.5% of H. axyridis were infected. Intraguild predation experiments between larvae of the two species showed a significant competitive advantage for H. axyridis, even against larger larvae of C. septempunctata. Adult C. septempunctata always killed and fed on H. axyridis larvae. However only 11.4% (4 of 47) of C. septempunctata that fed on infected H. axyridis died within 4 months. In contrast to previous studies this suggests that microsporidia or harmonine, the chemical defense compound of H. axyridis, do not lead to death of C. septempunctata preying on larvae of H. axyridis. Instead our results support the idea that competitive advantage during intraguild predation greatly facilitates the success of H. axyridis and that this may help this highly invasive species to outcompete native species. The impact of microsporidia on Harmonia itself as well as on interspecific interactions require further studies.}, }
@article {pmid25827421, year = {2015}, author = {Paredes, JC and Herren, JK and Schüpfer, F and Marin, R and Claverol, S and Kuo, CH and Lemaitre, B and Béven, L}, title = {Genome sequence of the Drosophila melanogaster male-killing Spiroplasma strain MSRO endosymbiont.}, journal = {mBio}, volume = {6}, number = {2}, pages = {}, pmid = {25827421}, issn = {2150-7511}, mesh = {Animals ; DNA, Bacterial/*chemistry/*genetics ; Drosophila melanogaster/*microbiology ; *Genome, Bacterial ; Molecular Sequence Data ; *Sequence Analysis, DNA ; Spiroplasma/*genetics/isolation &amp; purification/physiology ; Symbiosis ; }, abstract = {UNLABELLED: Spiroplasmas are helical and motile members of a cell wall-less eubacterial group called Mollicutes. Although all spiroplasmas are associated with arthropods, they exhibit great diversity with respect to both their modes of transmission and their effects on their hosts; ranging from horizontally transmitted pathogens and commensals to endosymbionts that are transmitted transovarially (i.e., from mother to offspring). Here we provide the first genome sequence, along with proteomic validation, of an endosymbiotic inherited Spiroplasma bacterium, the Spiroplasma poulsonii MSRO strain harbored by Drosophila melanogaster. Comparison of the genome content of S. poulsonii with that of horizontally transmitted spiroplasmas indicates that S. poulsonii has lost many metabolic pathways and transporters, demonstrating a high level of interdependence with its insect host. Consistent with genome analysis, experimental studies showed that S. poulsonii metabolizes glucose but not trehalose. Notably, trehalose is more abundant than glucose in Drosophila hemolymph, and the inability to metabolize trehalose may prevent S. poulsonii from overproliferating. Our study identifies putative virulence genes, notably, those for a chitinase, the H2O2-producing glycerol-3-phosphate oxidase, and enzymes involved in the synthesis of the eukaryote-toxic lipid cardiolipin. S. poulsonii also expresses on the cell membrane one functional adhesion-related protein and two divergent spiralin proteins that have been implicated in insect cell invasion in other spiroplasmas. These lipoproteins may be involved in the colonization of the Drosophila germ line, ensuring S. poulsonii vertical transmission. The S. poulsonii genome is a valuable resource to explore the mechanisms of male killing and symbiont-mediated protection, two cardinal features of many facultative endosymbionts.<br><br>IMPORTANCE: Most insect species, including important disease vectors and crop pests, harbor vertically transmitted endosymbiotic bacteria. These endosymbionts play key roles in their hosts' fitness, including protecting them against natural enemies and manipulating their reproduction in ways that increase the frequency of symbiont infection. Little is known about the molecular mechanisms that underlie these processes. Here, we provide the first genome draft of a vertically transmitted male-killing Spiroplasma bacterium, the S. poulsonii MSRO strain harbored by D. melanogaster. Analysis of the S. poulsonii genome was complemented by proteomics and ex vivo metabolic experiments. Our results indicate that S. poulsonii has reduced metabolic capabilities and expresses divergent membrane lipoproteins and potential virulence factors that likely participate in Spiroplasma-host interactions. This work fills a gap in our knowledge of insect endosymbionts and provides tools with which to decipher the interaction between Spiroplasma bacteria and their well-characterized host D. melanogaster, which is emerging as a model of endosymbiosis.}, }
@article {pmid25826386, year = {2015}, author = {Serbus, LR and White, PM and Silva, JP and Rabe, A and Teixeira, L and Albertson, R and Sullivan, W}, title = {The impact of host diet on Wolbachia titer in Drosophila.}, journal = {PLoS pathogens}, volume = {11}, number = {3}, pages = {e1004777}, pmid = {25826386}, issn = {1553-7374}, support = {T34 GM007910/GM/NIGMS NIH HHS/United States ; 2T34GM007910/GM/NIGMS NIH HHS/United States ; }, mesh = {*Animal Feed ; Animals ; Drosophila Proteins/genetics/metabolism ; Drosophila melanogaster ; Female ; Oocytes/metabolism/*microbiology ; Sirolimus/pharmacology ; Symbiosis/drug effects/*physiology ; Transcription Factors/genetics/metabolism ; Wolbachia/cytology/*metabolism ; }, abstract = {While a number of studies have identified host factors that influence endosymbiont titer, little is known concerning environmental influences on titer. Here we examined nutrient impact on maternally transmitted Wolbachia endosymbionts in Drosophila. We demonstrate that Drosophila reared on sucrose- and yeast-enriched diets exhibit increased and reduced Wolbachia titers in oogenesis, respectively. The yeast-induced Wolbachia depletion is mediated in large part by the somatic TOR and insulin signaling pathways. Disrupting TORC1 with the small molecule rapamycin dramatically increases oocyte Wolbachia titer, whereas hyper-activating somatic TORC1 suppresses oocyte titer. Furthermore, genetic ablation of insulin-producing cells located in the Drosophila brain abolished the yeast impact on oocyte titer. Exposure to yeast-enriched diets altered Wolbachia nucleoid morphology in oogenesis. Furthermore, dietary yeast increased somatic Wolbachia titer overall, though not in the central nervous system. These findings highlight the interactions between Wolbachia and germline cells as strongly nutrient-sensitive, and implicate conserved host signaling pathways by which nutrients influence Wolbachia titer.}, }
@article {pmid25825767, year = {2015}, author = {Karkar, S and Facchinelli, F and Price, DC and Weber, AP and Bhattacharya, D}, title = {Metabolic connectivity as a driver of host and endosymbiont integration.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, number = {33}, pages = {10208-10215}, pmid = {25825767}, issn = {1091-6490}, mesh = {Arabidopsis/genetics/metabolism ; *Biological Evolution ; Biological Transport ; Computational Biology ; Evolution, Molecular ; Oxidation-Reduction ; Photosynthesis ; Phylogeny ; Plastids/*genetics/metabolism ; Rhodophyta/metabolism ; Symbiosis/*genetics ; }, abstract = {The origin of oxygenic photosynthesis in the Archaeplastida common ancestor was foundational for the evolution of multicellular life. It is very likely that the primary endosymbiosis that explains plastid origin relied initially on the establishment of a metabolic connection between the host cell and captured cyanobacterium. We posit that these connections were derived primarily from existing host-derived components. To test this idea, we used phylogenomic and network analysis to infer the phylogenetic origin and evolutionary history of 37 validated plastid innermost membrane (permeome) metabolite transporters from the model plant Arabidopsis thaliana. Our results show that 57% of these transporter genes are of eukaryotic origin and that the captured cyanobacterium made a relatively minor (albeit important) contribution to the process. We also tested the hypothesis that the bacterium-derived hexose-phosphate transporter UhpC might have been the primordial sugar transporter in the Archaeplastida ancestor. Bioinformatic and protein localization studies demonstrate that this protein in the extremophilic red algae Galdieria sulphuraria and Cyanidioschyzon merolae are plastid targeted. Given this protein is also localized in plastids in the glaucophyte alga Cyanophora paradoxa, we suggest it played a crucial role in early plastid endosymbiosis by connecting the endosymbiont and host carbon storage networks. In summary, our work significantly advances understanding of plastid integration and favors a host-centric view of endosymbiosis. Under this view, nuclear genes of either eukaryotic or bacterial (noncyanobacterial) origin provided key elements of the toolkit needed for establishing metabolic connections in the primordial Archaeplastida lineage.}, }
@article {pmid25813874, year = {2015}, author = {Cerveau, N and Gilbert, C and Liu, C and Garrett, RA and Grève, P and Bouchon, D and Cordaux, R}, title = {Genomic context drives transcription of insertion sequences in the bacterial endosymbiont Wolbachia wVulC.}, journal = {Gene}, volume = {564}, number = {1}, pages = {81-86}, doi = {10.1016/j.gene.2015.03.044}, pmid = {25813874}, issn = {1879-0038}, mesh = {Animals ; DNA Transposable Elements ; Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; Isopoda/microbiology ; Promoter Regions, Genetic ; Symbiosis ; Transcription, Genetic ; Wolbachia/*genetics ; }, abstract = {Transposable elements (TEs) are DNA pieces that are present in almost all the living world at variable genomic density. Due to their mobility and density, TEs are involved in a large array of genomic modifications. In eukaryotes, TE expression has been studied in detail in several species. In prokaryotes, studies of IS expression are generally linked to particular copies that induce a modification of neighboring gene expression. Here we investigated global patterns of IS transcription in the Alphaproteobacterial endosymbiont Wolbachia wVulC, using both RT-PCR and bioinformatic analyses. We detected several transcriptional promoters in all IS groups. Nevertheless, only one of the potentially functional IS groups possesses a promoter located upstream of the transposase gene, that could lead up to the production of a functional protein. We found that the majority of IS groups are expressed whatever their functional status. RT-PCR analyses indicate that the transcription of two IS groups lacking internal promoters upstream of the transposase start codon may be driven by the genomic environment. We confirmed this observation with the transcription analysis of individual copies of one IS group. These results suggest that the genomic environment is important for IS expression and it could explain, at least partly, copy number variability of the various IS groups present in the wVulC genome and, more generally, in bacterial genomes.}, }
@article {pmid25809075, year = {2015}, author = {Christensen, S and Serbus, LR}, title = {Comparative analysis of wolbachia genomes reveals streamlining and divergence of minimalist two-component systems.}, journal = {G3 (Bethesda, Md.)}, volume = {5}, number = {5}, pages = {983-996}, pmid = {25809075}, issn = {2160-1836}, mesh = {Amino Acid Sequence ; Amino Acids ; Computational Biology/methods ; Gene Order ; Genes, Bacterial ; Genetic Loci ; *Genome, Bacterial ; *Genomics/methods ; Molecular Sequence Data ; Open Reading Frames ; Operon ; Protein Interaction Domains and Motifs ; Sequence Alignment ; *Signal Transduction ; Wolbachia/*genetics/*metabolism ; }, abstract = {Two-component regulatory systems are commonly used by bacteria to coordinate intracellular responses with environmental cues. These systems are composed of functional protein pairs consisting of a sensor histidine kinase and cognate response regulator. In contrast to the well-studied Caulobacter crescentus system, which carries dozens of these pairs, the streamlined bacterial endosymbiont Wolbachia pipientis encodes only two pairs: CckA/CtrA and PleC/PleD. Here, we used bioinformatic tools to compare characterized two-component system relays from C. crescentus, the related Anaplasmataceae species Anaplasma phagocytophilum and Ehrlichia chaffeensis, and 12 sequenced Wolbachia strains. We found the core protein pairs and a subset of interacting partners to be highly conserved within Wolbachia and these other Anaplasmataceae. Genes involved in two-component signaling were positioned differently within the various Wolbachia genomes, whereas the local context of each gene was conserved. Unlike Anaplasma and Ehrlichia, Wolbachia two-component genes were more consistently found clustered with metabolic genes. The domain architecture and key functional residues standard for two-component system proteins were well-conserved in Wolbachia, although residues that specify cognate pairing diverged substantially from other Anaplasmataceae. These findings indicate that Wolbachia two-component signaling pairs share considerable functional overlap with other α-proteobacterial systems, whereas their divergence suggests the potential for regulatory differences and cross-talk.}, }
@article {pmid25807173, year = {2015}, author = {Gauthier, JP and Outreman, Y and Mieuzet, L and Simon, JC}, title = {Bacterial communities associated with host-adapted populations of pea aphids revealed by deep sequencing of 16S ribosomal DNA.}, journal = {PloS one}, volume = {10}, number = {3}, pages = {e0120664}, pmid = {25807173}, issn = {1932-6203}, mesh = {Animals ; Aphids/classification/*genetics/microbiology ; Bacteria/isolation &amp; purification ; Buchnera/isolation &amp; purification ; Cluster Analysis ; Erwinia/isolation &amp; purification ; Genetic Variation ; Genotype ; High-Throughput Nucleotide Sequencing ; Molecular Sequence Data ; Pantoea/isolation &amp; purification ; Phylogeny ; RNA, Ribosomal, 16S ; Sequence Analysis, RNA ; Symbiosis ; Wolbachia/isolation &amp; purification ; }, abstract = {Associations between microbes and animals are ubiquitous and hosts may benefit from harbouring microbial communities through improved resource exploitation or resistance to environmental stress. The pea aphid, Acyrthosiphon pisum, is the host of heritable bacterial symbionts, including the obligate endosymbiont Buchnera aphidicola and several facultative symbionts. While obligate symbionts supply aphids with key nutrients, facultative symbionts influence their hosts in many ways such as protection against natural enemies, heat tolerance, color change and reproduction alteration. The pea aphid also encompasses multiple plant-specialized biotypes, each adapted to one or a few legume species. Facultative symbiont communities differ strongly between biotypes, although bacterial involvement in plant specialization is uncertain. Here, we analyse the diversity of bacterial communities associated with nine biotypes of the pea aphid complex using amplicon pyrosequencing of 16S rRNA genes. Combined clustering and phylogenetic analyses of 16S sequences allowed identifying 21 bacterial OTUs (Operational Taxonomic Unit). More than 98% of the sequencing reads were assigned to known pea aphid symbionts. The presence of Wolbachia was confirmed in A. pisum while Erwinia and Pantoea, two gut associates, were detected in multiple samples. The diversity of bacterial communities harboured by pea aphid biotypes was very low, ranging from 3 to 11 OTUs across samples. Bacterial communities differed more between than within biotypes but this difference did not correlate with the genetic divergence between biotypes. Altogether, these results confirm that the aphid microbiota is dominated by a few heritable symbionts and that plant specialization is an important structuring factor of bacterial communities associated with the pea aphid complex. However, since we examined the microbiota of aphid samples kept a few generations in controlled conditions, it may be that bacterial diversity was underestimated due to the possible loss of environmental or transient taxa.}, }
@article {pmid25801610, year = {2015}, author = {Raina, HS and Rawal, V and Singh, S and Daimei, G and Shakarad, M and Rajagopal, R}, title = {Elimination of Arsenophonus and decrease in the bacterial symbionts diversity by antibiotic treatment leads to increase in fitness of whitefly, Bemisia tabaci.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {32}, number = {}, pages = {224-230}, doi = {10.1016/j.meegid.2015.03.022}, pmid = {25801610}, issn = {1567-7257}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; DNA, Bacterial/genetics ; Enterobacteriaceae/classification/*drug effects ; Fertility ; Hemiptera/*microbiology/*physiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Tetracycline/pharmacology ; }, abstract = {Bemisia tabaci is an invasive agricultural pest with more than 24 genetic groups harboring different bacterial endosymbionts categorized into obligatory and facultative endosymbionts. Arsenophonus is one of the facultative endosymbionts prevalent in B. tabaci of Indian sub-continent. Not much is known about the functional role of this endosymbiont in its host. Some studies have revealed its involvement in virus transmission by B. tabaci, but how it effects the biology of B. tabaci is unknown. In this study, tetracycline was used to eliminate Arsenophonus from B. tabaci to study its effects with regard to development and other fitness parameters. Bacteria specific 16S Polymerase chain reaction (PCR) was used to ascertain Arsenophonus absence with differential effects on other secondary endosymbionts present in B. tabaci. Our results revealed that Arsenophonus negative (A(-)) whiteflies had more fecundity, increased juvenile developmental time, increased nymphal survival and increased adult life span as compared to control (A(+)) whiteflies. Thus, our results demonstrate that A(+) whiteflies have lesser fitness as compared to A(-) whiteflies. These observations give a new insight about the probable role of Arsenophonus in B. tabaci, that need to be explored further.}, }
@article {pmid25794152, year = {2015}, author = {Makai, S and Li, X and Hussain, J and Cui, C and Wang, Y and Chen, M and Yang, Z and Ma, C and Guo, AY and Zhou, Y and Chang, J and Yang, G and He, G}, title = {A census of nuclear cyanobacterial recruits in the plant kingdom.}, journal = {PloS one}, volume = {10}, number = {3}, pages = {e0120527}, pmid = {25794152}, issn = {1932-6203}, mesh = {Cyanobacteria/classification/*genetics ; Gene Transfer, Horizontal ; Genetic Variation ; Genome ; Genome, Mitochondrial ; Genome, Plastid ; Plants/*genetics ; Plastids/genetics ; *Symbiosis ; }, abstract = {The plastids and mitochondria of the eukaryotic cell are of endosymbiotic origin. These events occurred ~2 billion years ago and produced significant changes in the genomes of the host and the endosymbiont. Previous studies demonstrated that the invasion of land affected plastids and mitochondria differently and that the paths of mitochondrial integration differed between animals and plants. Other studies examined the reasons why a set of proteins remained encoded in the organelles and were not transferred to the nuclear genome. However, our understanding of the functional relations of the transferred genes is insufficient. In this paper, we report a high-throughput phylogenetic analysis to identify genes of cyanobacterial origin for plants of different levels of complexity: Arabidopsis thaliana, Chlamydomonas reinhardtii, Physcomitrella patens, Populus trichocarpa, Selaginella moellendorffii, Sorghum bicolor, Oryza sativa, and Ostreococcus tauri. Thus, a census of cyanobacterial gene recruits and a study of their function are presented to better understand the functional aspects of plastid symbiogenesis. From algae to angiosperms, the GO terms demonstrated a gradual expansion over functionally related genes in the nuclear genome, beginning with genes related to thylakoids and photosynthesis, followed by genes involved in metabolism, and finally with regulation-related genes, primarily in angiosperms. The results demonstrate that DNA is supplied to the nuclear genome on a permanent basis with no regard to function, and only what is needed is kept, which thereby expands on the GO space along the related genes.}, }
@article {pmid25788442, year = {2016}, author = {Pandey, N and Rajagopal, R}, title = {Molecular characterization and diversity analysis of bacterial communities associated with Dialeurolonga malleswaramensis (Hemiptera: Aleyrodidae) adults using 16S rDNA amplicon pyrosequencing and FISH.}, journal = {Insect science}, volume = {23}, number = {5}, pages = {704-711}, doi = {10.1111/1744-7917.12220}, pmid = {25788442}, issn = {1744-7917}, mesh = {Animals ; Bacteria/*genetics/isolation &amp; purification ; DNA, Bacterial/*genetics ; Hemiptera/genetics/*microbiology ; In Situ Hybridization, Fluorescence ; India ; Mitochondria/genetics ; Phylogeny ; Polyalthia/parasitology ; RNA, Ribosomal, 16S/*genetics ; Symbiosis ; }, abstract = {Dialeurolonga malleswaramensis Sundararaj (Hemiptera: Aleyrodidae) is a phytophagous sap sucking insect. It infests Polyalthia longifolia, an important avenue tree of India, effective in alleviating noise pollution and having immense medicinal importance. Samples of this insect were collected from Polyalthia longifolia. The cytochrome c oxidase subunit I gene (mtCO1) helped in the molecular characterization of the insect. This study reports the bacterial diversity in D. malleswaramensis adults by high throughput 16S rDNA amplicon pyrosequencing. The major genera identified were Portiera and Arsenophonus. Other bacterial genera detected were uncultured alpha proteobacterium, Sphingopyxis and Methylobacterium. We also employed fluorescence in situ hybridization (FISH) in whole mount samples to confirm the presence of dominant endosymbionts Portiera and Arsenophonus to the bacteriocyte of D. malleswaramensis. This study concludes that combining techniques like 16S rDNA amplicon pyrosequencing and FISH reveal both dominant and rare bacteria. The data also predict the evolutionary position of this pest with respect to other whitefly species using a mitochondrial marker.}, }
@article {pmid25786062, year = {2015}, author = {Dolch, LJ and Maréchal, E}, title = {Inventory of fatty acid desaturases in the pennate diatom Phaeodactylum tricornutum.}, journal = {Marine drugs}, volume = {13}, number = {3}, pages = {1317-1339}, pmid = {25786062}, issn = {1660-3397}, mesh = {Arabidopsis/metabolism ; Chloroplasts/metabolism ; Diatoms/*enzymology/genetics ; Endoplasmic Reticulum/metabolism ; Fatty Acid Desaturases/genetics/*metabolism ; Fatty Acids, Unsaturated/*metabolism ; Plastids/metabolism ; }, abstract = {The diatom Phaeodactylum is rich in very long chain polyunsaturated fatty acids (PUFAs). Fatty acid (FA) synthesis, elongation, and desaturation have been studied in depth in plants including Arabidopsis, but for secondary endosymbionts the full picture remains unclear. FAs are synthesized up to a chain length of 18 carbons inside chloroplasts, where they can be incorporated into glycerolipids. They are also exported to the ER for phospho- and betaine lipid syntheses. Elongation of FAs up to 22 carbons occurs in the ER. PUFAs can be reimported into plastids to serve as precursors for glycerolipids. In both organelles, FA desaturases are present, introducing double bonds between carbon atoms and giving rise to a variety of molecular species. In addition to the four desaturases characterized in Phaeodactylum (FAD2, FAD6, PtD5, PtD6), we identified eight putative desaturase genes. Combining subcellular localization predictions and comparisons with desaturases from other organisms like Arabidopsis, we propose a scheme at the whole cell level, including features that are likely specific to secondary endosymbionts.}, }
@article {pmid25782768, year = {2015}, author = {Chari, A and Oakeson, KF and Enomoto, S and Jackson, DG and Fisher, MA and Dale, C}, title = {Phenotypic characterization of Sodalis praecaptivus sp. nov., a close non-insect-associated member of the Sodalis-allied lineage of insect endosymbionts.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {65}, number = {Pt 5}, pages = {1400-1405}, pmid = {25782768}, issn = {1466-5034}, support = {R01 AI095736/AI/NIAID NIH HHS/United States ; 1R01AI095736/AI/NIAID NIH HHS/United States ; }, mesh = {Aged ; Animals ; Bacterial Proteins/genetics ; Base Composition ; Chaperonin 60/genetics ; DNA, Bacterial/genetics ; Enterobacteriaceae/*classification/genetics/isolation &amp; purification ; Genome, Bacterial ; Humans ; Insecta/microbiology ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Wounds and Injuries/*microbiology ; }, abstract = {A Gram-stain-negative bacterium, isolated from a human wound was previously found to share an unprecedentedly close relationship with Sodalis glossinidius and other members of the Sodalis-allied clade of insect symbionts. This relationship was inferred from sequence analysis of the 16S rRNA gene and genomic comparisons and suggested the strain belonged to a novel species. Biochemical and genetic analyses supported this suggestion and demonstrated that the organism has a wide repertoire of metabolic properties, which is consistent with the presence of a relatively large gene inventory. Among members of the Sodalis-allied clade, this is the first representative that has sufficient metabolic capabilities to sustain growth in minimal media. On the basis of the results of this study, we propose that this organism be classified as a representative of a novel species, Sodalis praecaptivus sp. nov. (type strain HS(T) = DSM 27494(T) = ATCC BAA-2554(T)).}, }
@article {pmid25782273, year = {2014}, author = {Mukhina, VS}, title = {[Origination and evolution of plastids].}, journal = {Zhurnal obshchei biologii}, volume = {75}, number = {5}, pages = {329-352}, pmid = {25782273}, issn = {0044-4596}, mesh = {Cyanobacteria/physiology ; *Evolution, Molecular ; Plastids/*physiology ; Protein Transport/physiology ; Symbiosis/physiology ; }, abstract = {Plastids are photosynthetic DNA-containing organelles of plants and algae. In the review, the history of their origination and evolution within different taxa is considered. All of the plastids appear to be descendants of cyanobacteria that colonized eukaryotic cells. The first plastids arose through symbiosis of cyanobacteria with algal ancestors from Archaeplastida kingdom. Later, there occurred repeated secondary symbioses of other eukariotes with photosynthetic protists: in this way plastids emerged in organisms of other taxa. Co-evolution of cyanobacteria and ancestral algae led to extensive transformation of both: reduction of endosymbiont, mass transfer of cyanobacteria genes into karyogenome, formation of complex system of proteins transportation to plastids and their functioning regulation.}, }
@article {pmid25772521, year = {2015}, author = {de Oliveira, CD and Gonçalves, DS and Baton, LA and Shimabukuro, PH and Carvalho, FD and Moreira, LA}, title = {Broader prevalence of Wolbachia in insects including potential human disease vectors.}, journal = {Bulletin of entomological research}, volume = {105}, number = {3}, pages = {305-315}, doi = {10.1017/S0007485315000085}, pmid = {25772521}, issn = {1475-2670}, mesh = {*Animal Distribution ; Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Brazil ; Cytoskeletal Proteins/genetics ; High-Throughput Screening Assays/methods ; Insect Vectors/*microbiology ; Insecta/*microbiology/physiology ; RNA, Ribosomal, 16S/genetics ; Real-Time Polymerase Chain Reaction/methods ; Species Specificity ; Wolbachia/*genetics ; }, abstract = {Wolbachia are intracellular, maternally transmitted bacteria considered the most abundant endosymbionts found in arthropods. They reproductively manipulate their host in order to increase their chances of being transmitted to the offspring, and currently are being used as a tool to control vector-borne diseases. Studies on distribution of Wolbachia among its arthropod hosts are important both for better understanding why this bacterium is so common, as well as for its potential use as a biological control agent. Here, we studied the incidence of Wolbachia in a broad range of insect species, collected from different regions of Brazil, using three genetic markers (16S rRNA, wsp and ftsZ), which varied in terms of their sensitivity to detect this bacterium. The overall incidence of Wolbachia among species belonging to 58 families and 14 orders was 61.9%. The most common positive insect orders were Coleoptera, Diptera, Hemiptera and Hymenoptera, with Diptera and Hemiptera having the highest numbers of Wolbachia-positive families. They included potential human disease vectors whose infection status has never been reported before. Our study further shows the importance of using quantitative polymerase chain reaction for high-throughput and sensitive Wolbachia screening.}, }
@article {pmid25769508, year = {2015}, author = {Whitman, WB}, title = {Genome sequences as the type material for taxonomic descriptions of prokaryotes.}, journal = {Systematic and applied microbiology}, volume = {38}, number = {4}, pages = {217-222}, doi = {10.1016/j.syapm.2015.02.003}, pmid = {25769508}, issn = {1618-0984}, mesh = {Bacteria/*classification/*genetics ; DNA, Bacterial/analysis/genetics ; Genome, Bacterial/*genetics ; *Genomics ; *Sequence Analysis, DNA ; }, abstract = {Genome sequencing of type strains promises to revolutionize prokaryotic systematics by greatly improving the identification of species, elucidating the functional properties of taxonomic groups, and resolving many of the ambiguities in the phylogeny of the higher taxa. Genome sequences could also serve as the type material for naming prokaryotic taxa, which will greatly expand the nomenclature governed by the Bacteriological Code to include many fastidious and uncultured organisms and endosymbionts of great biological interest.}, }
@article {pmid25764546, year = {2015}, author = {Xie, J and Winter, C and Winter, L and Mateos, M}, title = {Rapid spread of the defensive endosymbiont Spiroplasma in Drosophila hydei under high parasitoid wasp pressure.}, journal = {FEMS microbiology ecology}, volume = {91}, number = {2}, pages = {1-11}, doi = {10.1093/femsec/fiu017}, pmid = {25764546}, issn = {1574-6941}, mesh = {Animals ; Biological Evolution ; Drosophila/*microbiology ; Female ; Fertility/physiology ; Male ; Reproduction ; Sex Ratio ; Spiroplasma/*pathogenicity ; Symbiosis/*genetics ; Wasps/*growth &amp; development/*microbiology ; }, abstract = {Maternally transmitted endosymbionts of insects are ubiquitous in nature and play diverse roles in the ecology and evolution of their hosts. To persist in host lineages, many symbionts manipulate host reproduction to their advantage (e.g. cytoplasmic incompatibility and male-killing), or confer fitness benefits to their hosts (e.g. metabolic provisioning and defense against natural enemies). Recent studies suggest that strains of the bacterial genus Spiroplasma protect their host (flies in the genus Drosophila) against parasitoid attack. The Spiroplasma-conferred protection is partial and flies surviving a wasp attack have reduced adult longevity and fecundity. Therefore, it is unclear whether protection against wasps alone can counter Spiroplasma loss by imperfect maternal transmission and any possible fitness costs to harboring Spiroplasma. To address this question, we conducted a population cage study comparing Spiroplasma frequencies over time (host generations) under conditions of high wasp pressure and no wasp pressure. A dramatic increase of Spiroplasma prevalence was observed under high wasp pressure. In contrast, Spiroplasma prevalence in the absence of wasps did not change significantly over time; a pattern consistent with random drift. Thus, the defensive mechanism may contribute to the high prevalence of Spiroplasma in host populations despite imperfect vertical transmission.}, }
@article {pmid25758953, year = {2015}, author = {Domman, D and Horn, M and Embley, TM and Williams, TA}, title = {Plastid establishment did not require a chlamydial partner.}, journal = {Nature communications}, volume = {6}, number = {}, pages = {6421}, pmid = {25758953}, issn = {2041-1723}, support = {281633/ERC_/European Research Council/International ; 089803/WT_/Wellcome Trust/United Kingdom ; /WT_/Wellcome Trust/United Kingdom ; 268701/ERC_/European Research Council/International ; 045404/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Bacterial Proteins/genetics/metabolism ; Bayes Theorem ; Biological Evolution ; Carbohydrate Metabolism/*physiology ; Chlamydia/classification/*genetics/metabolism ; Cyanobacteria/classification/*genetics/metabolism ; Cyanophora/classification/*genetics/metabolism ; Gene Transfer, Horizontal ; Membrane Transport Proteins/genetics/metabolism ; Phylogeny ; Plastids/genetics/*metabolism ; Symbiosis/physiology ; }, abstract = {Primary plastids descend from the cyanobacterial endosymbiont of an ancient eukaryotic host, but the initial selective drivers that stabilized the association between these two cells are still unclear. One hypothesis that has achieved recent prominence suggests that the first role of the cyanobiont was in energy provision for a host cell whose reserves were being depleted by an intracellular chlamydial pathogen. A pivotal claim is that it was chlamydial proteins themselves that converted otherwise unusable cyanobacterial metabolites into host energy stores. We test this hypothesis by investigating the origins of the key enzymes using sophisticated phylogenetics. Here we show a mosaic origin for the relevant pathway combining genes with host, cyanobacterial or bacterial ancestry, but we detect no strong case for Chlamydiae to host transfer under the best-fitting models. Our conclusion is that there is no compelling evidence from gene trees that Chlamydiae played any role in establishing the primary plastid endosymbiosis.}, }
@article {pmid25741697, year = {2015}, author = {Maruyama, S and Shoguchi, E and Satoh, N and Minagawa, J}, title = {Diversification of the light-harvesting complex gene family via intra- and intergenic duplications in the coral symbiotic alga Symbiodinium.}, journal = {PloS one}, volume = {10}, number = {3}, pages = {e0119406}, pmid = {25741697}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*physiology ; Dinoflagellida/classification/genetics/*physiology ; *Gene Duplication ; Light-Harvesting Protein Complexes/*physiology ; Phylogeny ; *Symbiosis ; }, abstract = {The light-harvesting complex (LHC) is an essential component in light energy capture and transduction to facilitate downstream photosynthetic reactions in plant and algal chloroplasts. The unicellular dinoflagellate alga Symbiodinium is an endosymbiont of cnidarian animals, including corals and sea anemones, and provides carbohydrates generated through photosynthesis to host animals. Although Symbiodinium possesses a unique LHC gene family, called chlorophyll a-chlorophyll c2-peridinin protein complex (acpPC), its genome-level diversity and evolutionary trajectories have not been investigated. Here, we describe a phylogenetic analysis revealing that many of the LHCs are encoded by highly duplicated genes with multi-subunit polyprotein structures in the nuclear genome of Symbiodinium minutum. This analysis provides an extended list of the LHC gene family in a single organism, including 80 loci encoding polyproteins composed of 145 LHC subunits recovered in the phylogenetic tree. In S. minutum, 5 phylogenetic groups of the Lhcf-type gene family, which is exclusively conserved in algae harboring secondary plastids of red algal origin, were identified. Moreover, 5 groups of the Lhcr-type gene family, of which members are known to be associated with PSI in red algal plastids and secondary plastids of red algal origin, were identified. Notably, members classified within a phylogenetic group of the Lhcf-type (group F1) are highly duplicated, which may explain the presence of an unusually large number of LHC genes in this species. Some gene units were homologous to other units within single loci of the polyprotein genes, whereas intergenic homologies between separate loci were conspicuous in other cases, implying that gene unit 'shuffling' by gene conversion and/or genome rearrangement might have been a driving force for diversification. These results suggest that vigorous intra- and intergenic gene duplication events have resulted in the genomic framework of photosynthesis in coral symbiont dinoflagellate algae.}, }
@article {pmid25739443, year = {2015}, author = {Zheng, H and Dietrich, C and Thompson, CL and Meuser, K and Brune, A}, title = {Population structure of Endomicrobia in single host cells of termite gut flagellates (Trichonympha spp.).}, journal = {Microbes and environments}, volume = {30}, number = {1}, pages = {92-98}, pmid = {25739443}, issn = {1347-4405}, mesh = {Animals ; Bacteria/*classification/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Gastrointestinal Tract/parasitology ; Hypermastigia/*microbiology ; Isoptera/parasitology ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The gut microbiota of many phylogenetically lower termites is dominated by the cellulolytic flagellates of the genus Trichonympha, which are consistently associated with bacterial symbionts. In the case of Endomicrobia, an unusual lineage of endosymbionts of the Elusimicrobia phylum that is also present in other gut flagellates, previous studies have documented strict host specificity, leading to the cospeciation of "Candidatus Endomicrobium trichonymphae" with their respective flagellate hosts. However, it currently remains unclear whether one Trichonympha species is capable of harboring more than one Endomicrobia phylotype. In the present study, we selected single Trichonympha cells from the guts of Zootermopsis nevadensis and Reticulitermes santonensis and characterized their Endomicrobia populations based on internal transcribed spacer (ITS) region sequences. We found that each host cell harbored a homogeneous population of symbionts that were specific to their respective host species, but phylogenetically distinct between each host lineage, corroborating cospeciation being caused by vertical inheritance. The experimental design of the present study also allowed for the identification of an unexpectedly large amount of tag-switching between samples, which indicated that any high-resolution analysis of microbial community structures using the pyrosequencing technique has to be interpreted with great caution.}, }
@article {pmid25721539, year = {2015}, author = {Li, Y and Kocot, KM and Schander, C and Santos, SR and Thornhill, DJ and Halanych, KM}, title = {Mitogenomics reveals phylogeny and repeated motifs in control regions of the deep-sea family Siboglinidae (Annelida).}, journal = {Molecular phylogenetics and evolution}, volume = {85}, number = {}, pages = {221-229}, doi = {10.1016/j.ympev.2015.02.008}, pmid = {25721539}, issn = {1095-9513}, mesh = {Animals ; *Biological Evolution ; DNA, Mitochondrial/genetics ; Ecosystem ; *Genome, Mitochondrial ; *Phylogeny ; Polychaeta/*classification/genetics ; Sequence Analysis, DNA ; Symbiosis ; Transcriptome ; }, abstract = {Deep-sea tubeworms in the annelid family Siboglinidae have drawn considerable interest regarding their ecology and evolutionary biology. As adults, they lack a digestive tract and rely on endosymbionts for nutrition. Moreover, they are important members of chemosynthetic environments including hydrothermal vents, cold seeps, muddy sediments, and whale bones. Evolution and diversification of siboglinids has been associated with host-symbiont relationships and reducing habitats. Despite their importance, the taxonomy and phylogenetics of this clade are debated due to conflicting results. In this study, 10 complete and 2 partial mitochondrial genomes and one transcriptome were sequenced and analyzed to address siboglinid evolution. Notably, repeated nucleotide motifs were found in control regions of these mt genomes, which may explain previous challenges of sequencing siboglinid mt genomes. Phylogenetic analyses of amino acid and nucleotide datasets were conducted in order to infer evolutionary history. Both analyses generally had strong nodal support and suggest Osedax is most closely related to the Vestimentifera+Sclerolinum clade, rather than Frenulata, as recently reported. These results imply Osedax, the only siboglinid lineage with heterotrophic endosymbionts, evolved from a lineage utilizing chemoautotrophic symbionts.}, }
@article {pmid25716826, year = {2015}, author = {Santos-Garcia, D and Vargas-Chavez, C and Moya, A and Latorre, A and Silva, FJ}, title = {Genome evolution in the primary endosymbiont of whiteflies sheds light on their divergence.}, journal = {Genome biology and evolution}, volume = {7}, number = {3}, pages = {873-888}, pmid = {25716826}, issn = {1759-6653}, mesh = {Animals ; *Evolution, Molecular ; Genome, Bacterial ; Genomics ; Halomonadaceae/classification/*genetics/metabolism ; Hemiptera/classification/*microbiology ; *Symbiosis ; }, abstract = {Whiteflies are important agricultural insect pests, whose evolutionary success is related to a long-term association with a bacterial endosymbiont, Candidatus Portiera aleyrodidarum. To completely characterize this endosymbiont clade, we sequenced the genomes of three new Portiera strains covering the two extant whitefly subfamilies. Using endosymbiont and mitochondrial sequences we estimated the divergence dates in the clade and used these values to understand the molecular evolution of the endosymbiont coding sequences. Portiera genomes were maintained almost completely stable in gene order and gene content during more than 125 Myr of evolution, except in the Bemisia tabaci lineage. The ancestor had already lost the genetic information transfer autonomy but was able to participate in the synthesis of all essential amino acids and carotenoids. The time of divergence of the B. tabaci complex was much more recent than previous estimations. The recent divergence of biotypes B (MEAM1 species) and Q (MED species) suggests that they still could be considered strains of the same species. We have estimated the rates of evolution of Portiera genes, synonymous and nonsynonymous, and have detected significant differences among-lineages, with most Portiera lineages evolving very slowly. Although the nonsynonymous rates were much smaller than the synonymous, the genomic dN/dS ratios were similar, discarding selection as the driver of among-lineage variation. We suggest variation in mutation rate and generation time as the responsible factors. In conclusion, the slow evolutionary rates of Portiera may have contributed to its long-term association with whiteflies, avoiding its replacement by a novel and more efficient endosymbiont.}, }
@article {pmid25714744, year = {2015}, author = {Rollat-Farnier, PA and Santos-Garcia, D and Rao, Q and Sagot, MF and Silva, FJ and Henri, H and Zchori-Fein, E and Latorre, A and Moya, A and Barbe, V and Liu, SS and Wang, XW and Vavre, F and Mouton, L}, title = {Two host clades, two bacterial arsenals: evolution through gene losses in facultative endosymbionts.}, journal = {Genome biology and evolution}, volume = {7}, number = {3}, pages = {839-855}, pmid = {25714744}, issn = {1759-6653}, mesh = {Animals ; Aphids/*microbiology ; Cell Wall/chemistry ; Enterobacteriaceae/classification/*genetics/metabolism/pathogenicity ; *Evolution, Molecular ; *Gene Deletion ; Genome, Bacterial ; Genomics ; Hemiptera/*microbiology ; Phylogeny ; *Symbiosis ; Virulence Factors/genetics ; }, abstract = {Bacterial endosymbiosis is an important evolutionary process in insects, which can harbor both obligate and facultative symbionts. The evolution of these symbionts is driven by evolutionary convergence, and they exhibit among the tiniest genomes in prokaryotes. The large host spectrum of facultative symbionts and the high diversity of strategies they use to infect new hosts probably impact the evolution of their genome and explain why they undergo less severe genomic erosion than obligate symbionts. Candidatus Hamiltonella defensa is suitable for the investigation of the genomic evolution of facultative symbionts because the bacteria are engaged in specific relationships in two clades of insects. In aphids, H. defensa is found in several species with an intermediate prevalence and confers protection against parasitoids. In whiteflies, H. defensa is almost fixed in some species of Bemisia tabaci, which suggests an important role of and a transition toward obligate symbiosis. In this study, comparisons of the genome of H. defensa present in two B. tabaci species (Middle East Asia Minor 1 and Mediterranean) and in the aphid Acyrthosiphon pisum revealed that they belong to two distinct clades and underwent specific gene losses. In aphids, it contains highly virulent factors that could allow protection and horizontal transfers. In whiteflies, the genome lost these factors and seems to have a limited ability to acquire genes. However it contains genes that could be involved in the production of essential nutrients, which is consistent with a primordial role for this symbiont. In conclusion, although both lineages of H. defensa have mutualistic interactions with their hosts, their genomes follow distinct evolutionary trajectories that reflect their phenotype and could have important consequences on their evolvability.}, }
@article {pmid25713563, year = {2015}, author = {Erlacher, A and Cernava, T and Cardinale, M and Soh, J and Sensen, CW and Grube, M and Berg, G}, title = {Rhizobiales as functional and endosymbiontic members in the lichen symbiosis of Lobaria pulmonaria L.}, journal = {Frontiers in microbiology}, volume = {6}, number = {}, pages = {53}, pmid = {25713563}, issn = {1664-302X}, support = {I 882/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Rhizobiales (Alphaproteobacteria) are well-known beneficial partners in plant-microbe interactions. Less is known about the occurrence and function of Rhizobiales in the lichen symbiosis, although it has previously been shown that Alphaproteobacteria are the dominating group in growing lichen thalli. We have analyzed the taxonomic structure and assigned functions to Rhizobiales within a metagenomic dataset of the lung lichen Lobaria pulmonaria L. One third (32.2%) of the overall bacteria belong to the Rhizobiales, in particular to the families Methylobacteriaceae, Bradyrhizobiaceae, and Rhizobiaceae. About 20% of our metagenomic assignments could not be placed in any of the Rhizobiales lineages, which indicates a yet undescribed bacterial diversity. SEED-based functional analysis focused on Rhizobiales and revealed functions supporting the symbiosis, including auxin and vitamin production, nitrogen fixation and stress protection. We also have used a specifically developed probe to localize Rhizobiales by confocal laser scanning microscopy after fluorescence in situ hybridization (FISH-CLSM). Bacteria preferentially colonized fungal surfaces, but there is clear evidence that members of the Rhizobiales are able to intrude at varying depths into the interhyphal gelatinous matrix of the upper lichen cortical layer and that at least occasionally some bacteria also are capable to colonize the interior of the fungal hyphae. Interestingly, the gradual development of an endosymbiotic bacterial life was found for lichen- as well as for fungal- and plant-associated bacteria. The new tools to study Rhizobiales, FISH microscopy and comparative metagenomics, suggest a similar beneficial role for lichens than for plants and will help to better understand the Rhizobiales-host interaction and their biotechnological potential.}, }
@article {pmid25706947, year = {2015}, author = {Vanthournout, B and Hendrickx, F}, title = {Endosymbiont dominated bacterial communities in a dwarf spider.}, journal = {PloS one}, volume = {10}, number = {2}, pages = {e0117297}, pmid = {25706947}, issn = {1932-6203}, mesh = {Animals ; Bacteroidetes/genetics/*isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Rickettsia/genetics/*isolation &amp; purification ; Spiders/*microbiology ; Symbiosis/*genetics ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium) and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia) in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order.}, }
@article {pmid25697709, year = {2015}, author = {Corsaro, D and Venditti, D}, title = {Detection of novel Chlamydiae and Legionellales from human nasal samples of healthy volunteers.}, journal = {Folia microbiologica}, volume = {60}, number = {4}, pages = {325-334}, pmid = {25697709}, issn = {1874-9356}, mesh = {Amoeba/classification/genetics/isolation &amp; purification ; Chlamydiales/classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Healthy Volunteers ; Humans ; Legionellaceae/classification/genetics/*isolation &amp; purification ; *Microbiota ; Nasal Cavity/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {Chlamydiae are intracellular bacterial parasites of eukaryotes, ranging from amoebae to humans. They comprise many novel members and are investigated as emerging pathogens. Environmental studies highlighted similarities between the ecologies of chlamydiae and legionellae, both groups being important agents of respiratory infections. Herein, we analyzed nasal samples from healthy persons, searching for the presence of amoebae, chlamydiae and legionellae. From a total of 25 samples, we recovered by PCR eight samples positive to chlamydiae and six samples positive to legionellae. Among these samples, four were positive to both organisms. The sequencing of 16S rDNAs allowed to identify (i) among Chlamydiae: Parachlamydia acanthamoebae, Chlamydophila psittaci, Chlamydophila felis, and members of Rhabdochlamydiaceae, Simkaniaceae and E6 lineage and (ii) among Legionellaceae: Legionella longbeachae, Legionella bozemanii and Legionella impletisoli. Unexpectedly, we also recovered Diplorickettsia sp. Amoebae collected from nasal mucosae, Acanthamoeba and Vermamoeba, were endosymbiont-free, and chlamydiae revealed refractory to amoeba coculture. This study shows common exposure to chlamydiae and legionellae and suggests open air activities like gardening as a probable additional source of infection.}, }
@article {pmid25697664, year = {2015}, author = {Pagnier, I and Valles, C and Raoult, D and La Scola, B}, title = {Isolation of Vermamoeba vermiformis and associated bacteria in hospital water.}, journal = {Microbial pathogenesis}, volume = {80}, number = {}, pages = {14-20}, doi = {10.1016/j.micpath.2015.02.006}, pmid = {25697664}, issn = {1096-1208}, mesh = {Amoebozoa/classification/genetics/*isolation &amp; purification/*microbiology ; Chlamydiales/classification/genetics/*isolation &amp; purification ; Cluster Analysis ; France ; Hospitals ; Legionella/classification/genetics/*isolation &amp; purification ; Microscopy ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Homology ; Stenotrophomonas maltophilia/classification/genetics/*isolation &amp; purification ; Water/*parasitology ; }, abstract = {To detect new potential pathogens in hospital water, we isolated free-living amoebae in water samples taken from three different hospitals in Marseille (France). The samples were inoculated in media containing saline buffer and various bacteria as nutrient sources. The isolated amoebae were identified by gene sequencing. Among the 105 water samples, taken from 19 sites, we isolated 14 amoebae, of which 9 Vermamoeba vermiformis and 5 Acanthamoeba sp. None of the amoebae showed the presence of obligate bacterial endosymbionts. Because V. vermiformis was most commonly isolated, we used an axenic collection strain to isolate amoeba-resistant bacteria from the same sites. The isolated bacterial species included Stenotrophomonas maltophilia and Legionella sp. Legionella taurinensis was isolated for the first time in association with amoebae. A strict intracellular bacterium was isolated, that may represent a new genus among the Chlamydiales. We propose that it be named "Candidatus Rubidus massiliensis". Our study shows that the isolation and identification of new pathogens associated with amoebae, which were previously performed using Acanthamoeba sp., should instead use V. vermiformis because this organism is more commonly associated with humans and is an essential complement of Acanthamoeba sp. co-culture to study the ecology of hospital water supplies.}, }
@article {pmid25693143, year = {2015}, author = {Klueter, A and Crandall, JB and Archer, FI and Teece, MA and Coffroth, MA}, title = {Taxonomic and environmental variation of metabolite profiles in marine dinoflagellates of the genus symbiodinium.}, journal = {Metabolites}, volume = {5}, number = {1}, pages = {74-99}, pmid = {25693143}, issn = {2218-1989}, abstract = {Microorganisms in terrestrial and marine ecosystems are essential to environmental sustainability. In the marine environment, invertebrates often depend on metabolic cooperation with their endosymbionts. Coral reefs, one of the most important marine ecosystems, are based on the symbiosis between a broad diversity of dinoflagellates of the genus Symbiodinium and a wide phyletic diversity of hosts (i.e., cnidarian, molluscan, poriferan). This diversity is reflected in the ecology and physiology of the symbionts, yet the underlying biochemical mechanisms are still poorly understood. We examined metabolite profiles of four cultured species of Symbiodinium known to form viable symbioses with reef-building corals, S. microadriaticum (cp-type A194), S. minutum (cp-type B184), S. psygmophilum (cp-type B224) and S. trenchii (cp-type D206). Metabolite profiles were shown to differ among Symbiodinium species and were found to be affected by their physiological response to growth in different temperatures and light regimes. A combined Random Forests and Bayesian analysis revealed that the four Symbiodinium species examined primarily differed in their production of sterols and sugars, including a C29 stanol and the two sterols C28Δ5 and C28Δ5,22, as well as differences in metabolite abundances of a hexose and inositol. Inositol levels were also strongly affected by changes in temperature across all Symbiodinium species. Our results offer a detailed view of the metabolite profile characteristic of marine symbiotic dinoflagellates of the genus Symbiodinium, and identify patterns of metabolites related to several growth conditions.}, }
@article {pmid25690539, year = {2015}, author = {Durgo, H and Klement, E and Hunyadi-Gulyas, E and Szucs, A and Kereszt, A and Medzihradszky, KF and Kondorosi, E}, title = {Identification of nodule-specific cysteine-rich plant peptides in endosymbiotic bacteria.}, journal = {Proteomics}, volume = {15}, number = {13}, pages = {2291-2295}, doi = {10.1002/pmic.201400385}, pmid = {25690539}, issn = {1615-9861}, mesh = {Gene Expression Regulation, Plant/genetics ; Medicago truncatula/*metabolism/*microbiology ; Root Nodules, Plant/*metabolism/*microbiology ; Sinorhizobium meliloti/*physiology ; Symbiosis ; }, abstract = {The symbiosis of Medicago truncatula with Sinorhizobium meliloti or Sinorhizobium medicae soil bacteria results in the formation of root nodules where bacteria inside the plant cells are irreversibly converted to polyploid, nondividing nitrogen-fixing bacteroids. Bacteroid differentiation is host-controlled and the plant effectors are symbiosis-specific secreted plant peptides. In the M. truncatula genome there are more than 600 symbiotic peptide genes including 500 small genes coding for nodule-specific cysteine-rich (NCR) peptides. While NCR transcripts represent >5% of the nodule transcriptome, the existence of only eight NCR peptides has been demonstrated so far. The predicted NCRs are secreted peptides targeted to the endosymbionts. Correspondingly, all the eight detected peptides were present in the bacteroids. Here, we report on large-scale detection of NCR peptides from nodules and from isolated, semipurified endosymbionts at various stages of their differentiation. In total 138 NCRs were detected in the bacteroids; 38 were cationic while the majority was anionic. The presence of early NCRs in nitrogen-fixing bacteroids indicates their high stability, and their long-term maintenance suggests persisting biological roles in the bacteroids.}, }
@article {pmid25683348, year = {2015}, author = {Smith, AH and Łukasik, P and O'Connor, MP and Lee, A and Mayo, G and Drott, MT and Doll, S and Tuttle, R and Disciullo, RA and Messina, A and Oliver, KM and Russell, JA}, title = {Patterns, causes and consequences of defensive microbiome dynamics across multiple scales.}, journal = {Molecular ecology}, volume = {24}, number = {5}, pages = {1135-1149}, doi = {10.1111/mec.13095}, pmid = {25683348}, issn = {1365-294X}, mesh = {Adaptation, Biological/*genetics ; Animals ; Aphids/*microbiology ; Enterobacteriaceae/*classification/genetics ; *Microbiota ; Microsatellite Repeats ; Molecular Sequence Data ; New England ; *Seasons ; Sequence Analysis, DNA ; Symbiosis ; Temperature ; }, abstract = {The microbiome can significantly impact host phenotypes and serve as an additional source of heritable genetic variation. While patterns across eukaryotes are consistent with a role for symbiotic microbes in host macroevolution, few studies have examined symbiont-driven host evolution or the ecological implications of a dynamic microbiome across temporal, spatial or ecological scales. The pea aphid, Acyrthosiphon pisum, and its eight heritable bacterial endosymbionts have served as a model for studies on symbiosis and its potential contributions to host ecology and evolution. But we know little about the natural dynamics or ecological impacts of the heritable microbiome of this cosmopolitan insect pest. Here we report seasonal shifts in the frequencies of heritable defensive bacteria from natural pea aphid populations across two host races and geographic regions. Microbiome dynamics were consistent with symbiont responses to host-level selection and findings from one population suggested symbiont-driven adaptation to seasonally changing parasitoid pressures. Conversely, symbiont levels were negatively correlated with enemy-driven mortality when measured across host races, suggesting important ecological impacts of host race microbiome divergence. Rapid drops in symbiont frequencies following seasonal peaks suggest microbiome instability in several populations, with potentially large costs of 'superinfection' under certain environmental conditions. In summary, the realization of several laboratory-derived, a priori expectations suggests important natural impacts of defensive symbionts in host-enemy eco-evolutionary feedbacks. Yet negative findings and unanticipated correlations suggest complexities within this system may limit or obscure symbiont-driven contemporary evolution, a finding of broad significance given the widespread nature of defensive microbes across plants and animals.}, }
@article {pmid25681033, year = {2015}, author = {Lis, A and Maryańska-Nadachowska, A and Kajtoch, &#x141;}, title = {Relations of Wolbachia Infection with Phylogeography of Philaenus spumarius (Hemiptera: Aphrophoridae) Populations Within and Beyond the Carpathian Contact Zone.}, journal = {Microbial ecology}, volume = {70}, number = {2}, pages = {509-521}, pmid = {25681033}, issn = {1432-184X}, mesh = {Animals ; DNA, Mitochondrial/genetics ; Hemiptera/*microbiology ; Multilocus Sequence Typing ; Phylogeny ; Wolbachia/drug effects/genetics/*physiology ; }, abstract = {Wolbachia is the most widespread intracellular α-proteobacteria maternally inherited endosymbiont of insects and nematodes. These bacteria are associated with a number of different reproductive phenotypes of their hosts. Relatively few studies have dealt with distribution of infections across populations and with the influence of these bacteria on host genetic diversification and speciation. The aims of this study are to determine the distribution and rate of infection and to characterize the Wolbachia strains associated with Philaenus spumarius spittlebug (Hemiptera) by using multilocus sequencing typing (MLST) analysis and host phylogeography. The results showed that infection rate was significantly different between members of both main mitochondrial phylogenetic lineages of P. spumarius. We detected much higher infection rates of Wolbachia in P. spumarius populations from the north-east clade than the south-west clade. Moreover, the frequency of these infections varied within and outside the contact zone known from the Carpathians. Given the reproductive alterations which are often associated with this endosymbiont, Wolbachia probably maintain genetic differentiation of its hosts in its contact zone in the Carpathians. This is one of the first studies demonstrating the presence of Wolbachia across a large part of the range of insect species, including the contact zone. The spread of Wolbachia in P. spumarius populations can potentially cause speciation by compromising the potential reproductive barrier between infected and uninfected populations. We discuss possible implications of Wolbachia infection inducing cytoplasmic incompatibility in the population dynamics of this spittlebug but confirm that more studies are also required.}, }
@article {pmid25677805, year = {2015}, author = {Rzotkiewicz, S and Gutiérrez, R and Krasnov, BR and Morick, D and Khokhlova, IS and Nachum-Biala, Y and Baneth, G and Harrus, S}, title = {Novel evidence suggests that a 'Rickettsia felis-like' organism is an endosymbiont of the desert flea, Xenopsylla ramesis.}, journal = {Molecular ecology}, volume = {24}, number = {6}, pages = {1364-1373}, doi = {10.1111/mec.13106}, pmid = {25677805}, issn = {1365-294X}, support = {KP050777-81//PHS HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/genetics ; Genes, Bacterial ; Israel ; RNA, Ribosomal, 16S/genetics ; Rickettsia felis/*genetics ; Rodentia/parasitology ; Sequence Analysis, DNA ; *Symbiosis ; Xenopsylla/*microbiology ; }, abstract = {Fleas are acknowledged vectors and reservoirs of various bacteria that present a wide range of pathogenicity. In this study, fleas collected from wild rodents from the Negev desert in southern Israel were tested for RickettsiaDNA by targeting the 16S rRNA (rrs) gene. Thirty-eight Xenopsylla ramesis, 91 Synosternus cleopatrae and 15 Leptopsylla flea pools (a total of 568 fleas) were screened. RickettsiaDNA was detected in 100% of the X. ramesis and in one S. cleopatrae flea pools. None of L. algira flea pools was found positive. All positive flea pools were further characterized by sequencing of five additional genetic loci (gltA, ompB, ompA, htrA and fusA). The molecular identification of the positive samples showed all sequences to be closely related to the 'Rickettsia felis-like' organisms (99-100% similarities in the six loci). To further investigate the association between 'R. felis-like' and X. ramesis fleas, ten additional single X. ramesis adult fleas collected from the wild and five laboratory-maintained X. ramesis imago, five larva pools (2-18 larvae per pool) and two egg pools (18 eggs per pool) were tested for the presence of 'R. felis-like' DNA. All samples were found positive by a specific ompAPCR assay, confirming the close association of this Rickettsia species with X. ramesis in all its life stages. These results suggest a symbiotic association between 'Rickettsia felis-like' and X. ramesis fleas.}, }
@article {pmid25675099, year = {2015}, author = {Ahmed, MZ and Li, SJ and Xue, X and Yin, XJ and Ren, SX and Jiggins, FM and Greeff, JM and Qiu, BL}, title = {The intracellular bacterium Wolbachia uses parasitoid wasps as phoretic vectors for efficient horizontal transmission.}, journal = {PLoS pathogens}, volume = {10}, number = {2}, pages = {e1004672}, pmid = {25675099}, issn = {1553-7374}, mesh = {Animals ; Cytoplasm/*metabolism ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Multilocus Sequence Typing/methods ; Wasps/genetics/*microbiology ; *Wolbachia/genetics ; }, abstract = {Facultative bacterial endosymbionts are associated with many arthropods and are primarily transmitted vertically from mother to offspring. However, phylogenetic affiliations suggest that horizontal transmission must also occur. Such horizontal transfer can have important biological and agricultural consequences when endosymbionts increase host fitness. So far horizontal transmission is considered rare and has been difficult to document. Here, we use fluorescence in situ hybridization (FISH) and multi locus sequence typing (MLST) to reveal a potentially common pathway of horizontal transmission of endosymbionts via parasitoids of insects. We illustrate that the mouthparts and ovipositors of an aphelinid parasitoid become contaminated with Wolbachia when this wasp feeds on or probes Wolbachia-infected Bemisia tabaci AsiaII7, and non-lethal probing of uninfected B. tabaci AsiaII7 nymphs by parasitoids carrying Wolbachia resulted in newly and stably infected B. tabaci matrilines. After they were exposed to infected whitefly, the parasitoids were able to transmit Wolbachia efficiently for the following 48 h. Whitefly infected with Wolbachia by parasitoids had increased survival and reduced development times. Overall, our study provides evidence for the horizontal transmission of Wolbachia between insect hosts by parasitic wasps, and the enhanced survival and reproductive abilities of insect hosts may adversely affect biological control programs.}, }
@article {pmid25673050, year = {2015}, author = {Evangelista, DE and de Paula, FF and Rodrigues, A and Henrique-Silva, F}, title = {Pectinases from Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae): putative accessory digestive enzymes.}, journal = {Journal of insect science (Online)}, volume = {15}, number = {1}, pages = {168}, pmid = {25673050}, issn = {1536-2442}, mesh = {Amino Acid Sequence ; Animals ; Bacteria ; Base Sequence ; Carboxylic Ester Hydrolases/*genetics ; Cell Wall/metabolism ; DNA, Complementary ; Fungi ; Gastrointestinal Tract/*enzymology ; Larva/enzymology/genetics ; Pecten/metabolism ; Phylogeny ; Polygalacturonase/*genetics ; RNA, Messenger ; Weevils/*enzymology/*genetics ; }, abstract = {The cell wall in plants offers protection against invading organisms and is mainly composed of the polysaccharides pectin, cellulose, and hemicellulose, which can be degraded by plant cell wall degrading enzymes (PCWDEs). Such enzymes are often synthesized by free living microorganisms or endosymbionts that live in the gut of some animals, including certain phytophagous insects. Thus, the ability of an insect to degrade the cell wall was once thought to be related to endosymbiont enzyme activity. However, recent studies have revealed that some phytophagous insects are able to synthesize their own PCWDEs by endogenous genes, although questions regarding the origin of these genes remain unclear. This study describes two pectinases from the sugarcane weevil, Sphenophorus levis Vaurie, 1978 (Sl-pectinases), which is considered one of the most serious agricultural pests in Brazil. Two cDNA sequences identified in a cDNA library of the insect larvae coding for a pectin methylesterase (PME) and an endo-polygalacturonase (endo-PG)-denominated Sl-PME and Sl-endoPG, respectively-were isolated and characterized. The quantitative real-time reverse transcriptase polymerase chain reaction expression profile for both Sl-pectinases showed mRNA production mainly in the insect feeding stages and exclusively in midgut tissue of the larvae. This analysis, together Western blotting data, suggests that Sl-pectinases have a digestive role. Phylogenetic analyses indicate that Sl-PME and Sl-endoPG sequences are closely related to bacteria and fungi, respectively. Moreover, the partial genomic sequences of the pectinases were amplified from insect fat body DNA, which was certified to be free of endosymbiotic DNA. The analysis of genomic sequences revealed the existence of two small introns with 53 and 166 bp in Sl-endoPG, which is similar to the common pattern in fungal introns. In contrast, no intron was identified in the Sl-PME genomic sequence, as generally observed in bacteria. These data support the theory of horizontal gene transfer proposed for the origin of insect pectinases, reinforcing the acquisition of PME genes from bacteria and endo-PG genes from fungi.}, }
@article {pmid25671568, year = {2015}, author = {Kawafune, K and Hongoh, Y and Hamaji, T and Sakamoto, T and Kurata, T and Hirooka, S and Miyagishima, SY and Nozaki, H}, title = {Two different rickettsial bacteria invading Volvox carteri.}, journal = {PloS one}, volume = {10}, number = {2}, pages = {e0116192}, pmid = {25671568}, issn = {1932-6203}, mesh = {Gene Order ; Genes, Bacterial ; Genome, Bacterial ; Molecular Sequence Data ; Phylogeny ; Rickettsiaceae/*classification/*genetics ; Sequence Analysis, DNA ; Volvox/*microbiology ; }, abstract = {BACKGROUND: Bacteria of the family Rickettsiaceae are principally associated with arthropods. Recently, endosymbionts of the Rickettsiaceae have been found in non-phagotrophic cells of the volvocalean green algae Carteria cerasiformis, Pleodorina japonica, and Volvox carteri. Such endosymbionts were present in only C. cerasiformis strain NIES-425 and V. carteri strain UTEX 2180, of various strains of Carteria and V. carteri examined, suggesting that rickettsial endosymbionts may have been transmitted to only a few algal strains very recently. However, in preliminary work, we detected a sequence similar to that of a rickettsial gene in the nuclear genome of V. carteri strain EVE.<br><br>Here we explored the origin of the rickettsial gene-like sequences in the endosymbiont-lacking V. carteri strain EVE, by performing comparative analyses on 13 strains of V. carteri. By reference to our ongoing genomic sequence of rickettsial endosymbionts in C. cerasiformis strain NIES-425 cells, we confirmed that an approximately 9-kbp DNA sequence encompassing a region similar to that of four rickettsial genes was present in the nuclear genome of V. carteri strain EVE. Phylogenetic analyses, and comparisons of the synteny of rickettsial gene-like sequences from various strains of V. carteri, indicated that the rickettsial gene-like sequences in the nuclear genome of V. carteri strain EVE were closely related to rickettsial gene sequences of P. japonica, rather than those of V. carteri strain UTEX 2180.<br><br>CONCLUSION/SIGNIFICANCE: At least two different rickettsial organisms may have invaded the V. carteri lineage, one of which may be the direct ancestor of the endosymbiont of V. carteri strain UTEX 2180, whereas the other may be closely related to the endosymbiont of P. japonica. Endosymbiotic gene transfer from the latter rickettsial organism may have occurred in an ancestor of V. carteri. Thus, the rickettsiae may be widely associated with V. carteri, and likely have often been lost during host evolution.}, }
@article {pmid25668031, year = {2015}, author = {Chrostek, E and Teixeira, L}, title = {Mutualism breakdown by amplification of Wolbachia genes.}, journal = {PLoS biology}, volume = {13}, number = {2}, pages = {e1002065}, pmid = {25668031}, issn = {1545-7885}, support = {/WT_/Wellcome Trust/United Kingdom ; 094664/Z/10/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Biological Evolution ; Colony Count, Microbial ; Drosophila melanogaster/immunology/*microbiology ; Gene Dosage ; *Genome, Bacterial ; Genotype ; Longevity ; Multigene Family ; Phenotype ; Selection, Genetic ; Symbiosis/*genetics ; Virulence ; Wolbachia/*genetics/growth &amp; development/*pathogenicity ; }, abstract = {Most insect species are associated with vertically transmitted endosymbionts. Because of the mode of transmission, the fitness of these symbionts is dependent on the fitness of the hosts. Therefore, these endosymbionts need to control their proliferation in order to minimize their cost for the host. The genetic bases and mechanisms of this regulation remain largely undetermined. The maternally inherited bacteria of the genus Wolbachia are the most common endosymbionts of insects, providing some of them with fitness benefits. In Drosophila melanogaster, Wolbachia wMelPop is a unique virulent variant that proliferates massively in the hosts and shortens their lifespan. The genetic bases of wMelPop virulence are unknown, and their identification would allow a better understanding of how Wolbachia levels are regulated. Here we show that amplification of a region containing eight Wolbachia genes, called Octomom, is responsible for wMelPop virulence. Using Drosophila lines selected for carrying Wolbachia with different Octomom copy numbers, we demonstrate that the number of Octomom copies determines Wolbachia titers and the strength of the lethal phenotype. Octomom amplification is unstable, and reversion of copy number to one reverts all the phenotypes. Our results provide a link between genotype and phenotype in Wolbachia and identify a genomic region regulating Wolbachia proliferation. We also prove that these bacteria can evolve rapidly. Rapid evolution by changes in gene copy number may be common in endosymbionts with a high number of mobile elements and other repeated regions. Understanding wMelPop pathogenicity and variability also allows researchers to better control and predict the outcome of releasing mosquitoes transinfected with this variant to block human vector-borne diseases. Our results show that transition from a mutualist to a pathogen may occur because of a single genomic change in the endosymbiont. This implies that there must be constant selection on endosymbionts to control their densities.}, }
@article {pmid25666656, year = {2015}, author = {Wójcik-Fatla, A and Zając, V and Sawczyn, A and Cisak, E and Sroka, J and Dutkiewicz, J}, title = {Occurrence of Francisella spp. in Dermacentor reticulatus and Ixodes ricinus ticks collected in eastern Poland.}, journal = {Ticks and tick-borne diseases}, volume = {6}, number = {3}, pages = {253-257}, doi = {10.1016/j.ttbdis.2015.01.005}, pmid = {25666656}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Proteins/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Dermacentor/*microbiology ; Female ; Francisella tularensis/classification/genetics/*isolation &amp; purification ; Humans ; Ixodes/*microbiology ; Lipoproteins/genetics ; Male ; Phylogeography ; Poland/epidemiology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Tick-Borne Diseases/*epidemiology/microbiology ; Tularemia/*epidemiology/microbiology ; }, abstract = {A total of 530 questing Dermacentor reticulatus ticks and 861 questing Ixodes ricinus ticks were collected from Lublin province (eastern Poland) and examined for the presence of Francisella by PCR for 16S rRNA (rrs) and tul4 genes. Only one female D. reticulatus tick out of 530 examined (0.2%) was infected with Francisella tularensis subspecies holarctica, as determined by PCR of the rrs gene. None of 861 I. ricinus ticks were infected with F. tularensis. In contrast, the presence of Francisella-like endosymbionts (FLEs) was detected in more than half of the D. reticulatus ticks (50.4%) and 0.8% of the I. ricinus ticks. The nucleotide sequences of the FLEs detected in D. reticulatus exhibited 100% homology with the nucleotide sequence of the FLE strain FDrH detected in Hungary in D. reticulatus. In conclusion, our results suggest a low contribution of D. reticulatus and I. ricinus ticks to the circulation of F. tularensis in eastern Poland. This finding, however, needs to be confirmed by further studies in other areas. Our study confirmed the common infection of D. reticulatus with Francisella-like endosymbionts (FLEs) of unknown pathogenic potential and revealed, for the first time, a low grade of infection of I. ricinus with FLEs.}, }
@article {pmid25664570, year = {2015}, author = {Xiang, T and Nelson, W and Rodriguez, J and Tolleter, D and Grossman, AR}, title = {Symbiodinium transcriptome and global responses of cells to immediate changes in light intensity when grown under autotrophic or mixotrophic conditions.}, journal = {The Plant journal : for cell and molecular biology}, volume = {82}, number = {1}, pages = {67-80}, doi = {10.1111/tpj.12789}, pmid = {25664570}, issn = {1365-313X}, mesh = {Animals ; Anthozoa ; Coral Reefs ; Dinoflagellida/*genetics/physiology/radiation effects/ultrastructure ; Gene Expression Profiling ; Gene Expression Regulation/*radiation effects ; Light ; Microscopy, Electron, Scanning ; RNA, Messenger/genetics ; RNA, Spliced Leader/genetics ; Sea Anemones ; Symbiosis ; *Transcriptome ; }, abstract = {Symbiosis between unicellular dinoflagellates (genus Symbiodinium) and their cnidarian hosts (e.g. corals, sea anemones) is the foundation of coral reef ecosystems. Dysfunction of this symbiosis under changing environmental conditions has led to global reef decline. Little information is known about Symbiodinium gene expression and mechanisms by which light impacts host-symbiont associations. To address these issues, we generated a transcriptome from axenic Symbiodinium strain SSB01. Here we report features of the transcriptome, including occurrence and length distribution of spliced leader sequences, the functional landscape of encoded proteins and the impact of light on gene expression. Expression of many Symbiodinium genes appears to be significantly impacted by light. Transcript encoding cryptochrome 2 declined in high light while some transcripts for Regulators of Chromatin Condensation (RCC1) declined in the dark. We also identified a transcript encoding a light harvesting AcpPC protein with homology to Chlamydomonas LHCSR2. The level of this transcript increased in high light autotrophic conditions, suggesting that it is involved in photo-protection and the dissipation of excess absorbed light energy. The most extensive changes in transcript abundances occurred when the algae were transferred from low light to darkness. Interestingly, transcripts encoding several cell adhesion proteins rapidly declined following movement of cultures to the dark, which correlated with a dramatic change in cell surface morphology, likely reflecting the complexity of the extracellular matrix. Thus, light-sensitive cell adhesion proteins may play a role in establishing surface architecture, which may in turn alter interactions between the endosymbiont and its host.}, }
@article {pmid25663508, year = {2015}, author = {Schwarte, S and Wegner, F and Havenstein, K and Groth, D and Steup, M and Tiedemann, R}, title = {Sequence variation, differential expression, and divergent evolution in starch-related genes among accessions of Arabidopsis thaliana.}, journal = {Plant molecular biology}, volume = {87}, number = {4-5}, pages = {489-519}, pmid = {25663508}, issn = {1573-5028}, mesh = {Arabidopsis/classification/*genetics/metabolism ; Arabidopsis Proteins/chemistry/*genetics/metabolism ; *Evolution, Molecular ; *Gene Expression Regulation, Plant ; *Genetic Variation ; Starch/*metabolism ; }, abstract = {Transitory starch metabolism is a nonlinear and highly regulated process. It originated very early in the evolution of chloroplast-containing cells and is largely based on a mosaic of genes derived from either the eukaryotic host cell or the prokaryotic endosymbiont. Initially located in the cytoplasm, starch metabolism was rewired into plastids in Chloroplastida. Relocation was accompanied by gene duplications that occurred in most starch-related gene families and resulted in subfunctionalization of the respective gene products. Starch-related isozymes were then evolutionary conserved by constraints such as internal starch structure, posttranslational protein import into plastids and interactions with other starch-related proteins. 25 starch-related genes in 26 accessions of Arabidopsis thaliana were sequenced to assess intraspecific diversity, phylogenetic relationships, and modes of selection. Furthermore, sequences derived from additional 80 accessions that are publicly available were analyzed. Diversity varies significantly among the starch-related genes. Starch synthases and phosphorylases exhibit highest nucleotide diversities, while pyrophosphatases and debranching enzymes are most conserved. The gene trees are most compatible with a scenario of extensive recombination, perhaps in a Pleistocene refugium. Most genes are under purifying selection, but disruptive selection was inferred for a few genes/substitutiones. To study transcript levels, leaves were harvested throughout the light period. By quantifying the transcript levels and by analyzing the sequence of the respective accessions, we were able to estimate whether transcript levels are mainly determined by genetic (i.e., accession dependent) or physiological (i.e., time dependent) parameters. We also identified polymorphic sites that putatively affect pattern or the level of transcripts.}, }
@article {pmid25657277, year = {2015}, author = {Yamaguchi, H and Matsuo, J and Yamazaki, T and Ishida, K and Yagita, K}, title = {Draft Genome Sequence of High-Temperature-Adapted Protochlamydia sp. HS-T3, an Amoebal Endosymbiotic Bacterium Found in Acanthamoeba Isolated from a Hot Spring in Japan.}, journal = {Genome announcements}, volume = {3}, number = {1}, pages = {}, pmid = {25657277}, issn = {2169-8287}, abstract = {Here, we report the draft genome sequence of high-temperature-adapted Protochlamydia sp. strain HS-T3, an environmental chlamydia. This bacterium is an amoebal endosymbiont, found in Acanthamoeba isolated from a hot spring in Japan. Strain HS-T3 readily grew in mammalian cells at 37°C, a characteristic not previously reported for environmental chlamydiae.}, }
@article {pmid25649504, year = {2015}, author = {Nakayama, S and Parratt, SR and Hutchence, KJ and Lewis, Z and Price, TA and Hurst, GD}, title = {Can maternally inherited endosymbionts adapt to a novel host? Direct costs of Spiroplasma infection, but not vertical transmission efficiency, evolve rapidly after horizontal transfer into D. melanogaster.}, journal = {Heredity}, volume = {114}, number = {6}, pages = {539-543}, pmid = {25649504}, issn = {1365-2540}, mesh = {*Adaptation, Biological ; Animals ; *Biological Evolution ; Drosophila melanogaster/*microbiology ; Female ; Genetic Fitness ; Linear Models ; Male ; Spiroplasma/*physiology ; *Symbiosis ; }, abstract = {Maternally inherited symbionts are common in arthropods and many have important roles in host adaptation. The observation that specific symbiont lineages infect distantly related host species implies new interactions are commonly established by lateral transfer events. However, studies have shown that symbionts often perform poorly in novel hosts. We hypothesized selection on the symbiont may be sufficiently rapid that poor performance in a novel host environment is rapidly ameliorated, permitting symbiont maintenance. Here, we test this prediction for a Spiroplasma strain transinfected into the novel host Drosophila melanogaster. In the generations immediately following transinfection, the symbiont had low transmission efficiency to offspring and imposed severe fitness costs on its host. We observed that effects on host fitness evolved rapidly, being undetectable after 17 generations in the novel host, whereas vertical transmission efficiency was poorly responsive over this period. Our results suggest that long-term symbiosis may more readily be established in cases where symbionts perform poorly in just one aspect of symbiosis.}, }
@article {pmid25649218, year = {2015}, author = {Chagas-Moutinho, VA and Silva, R and de Souza, W and Motta, MC}, title = {Identification and ultrastructural characterization of the Wolbachia symbiont in Litomosoides chagasfilhoi.}, journal = {Parasites &amp; vectors}, volume = {8}, number = {}, pages = {74}, pmid = {25649218}, issn = {1756-3305}, mesh = {Animals ; Female ; Filarioidea/*microbiology/physiology ; Male ; Microscopy, Electron, Transmission ; Phylogeny ; Subcutaneous Tissue/microbiology ; *Symbiosis ; Wolbachia/genetics/*isolation &amp; purification/*physiology/ultrastructure ; }, abstract = {BACKGROUND: Filarial nematodes are arthropod-transmitted parasites of vertebrates that affect more than 150 million people around the world and remain a major public health problem throughout tropical and subtropical regions. Despite the importance of these nematodes, the current treatment strategies are not efficient in eliminating the parasite. The main strategy of control is based on chemotherapy with diethylcarbamazine, albendazole and ivermectin. In the 1970s, it was found that some filarids possess endosymbiotic bacteria that are important for the development, survival and infectivity of the nematodes. These bacteria belong to the genus Wolbachia, which is a widespread and abundant intracellular symbiont in worms. Knowledge about the structure of the bacteria and their relationship with their nematode hosts may allow new perspectives for the control of filarial nematodes.<br><br>METHODS: In this study, we used transmission electron microscopy combined with three-dimensional approaches to observe the structure of the endosymbiont of the filarial nematode Litomosoides chagasfilhoi, an experimental model for the study of lymphatic filariasis. In addition, the bacterium was classified based on PCR analyses.<br><br>RESULTS: The bacterium was mainly found in the hypodermis and in the female reproductive system in close association with host cell structures, such as the nucleus and endoplasmic reticulum. Our ultrastructural data also showed that the symbiont envelope is composed of two membrane units and is enclosed in a cytoplasmic vacuole, the symbiosome. Molecular data revealed that the bacterium of L. chagasfilhoi shares 100% identity with the Wolbachia endosymbiont of Litomosoides galizai.<br><br>CONCLUSIONS: Here we described ultrastructural aspects of the relationship of the Wolbachia with the filarial nematode Litomosoides chagasfilhoi and the findings lead us to consider this relationship as a mutualistic symbiosis.}, }
@article {pmid25643359, year = {2015}, author = {Yamane, C and Yamazaki, T and Nakamura, S and Matsuo, J and Ishida, K and Yamazaki, S and Oguri, S and Shouji, N and Hayashi, Y and Yoshida, M and Yimin,  and Yamaguchi, H}, title = {Amoebal endosymbiont Parachlamydia acanthamoebae Bn9 can grow in immortal human epithelial HEp-2 cells at low temperature; an in vitro model system to study chlamydial evolution.}, journal = {PloS one}, volume = {10}, number = {2}, pages = {e0116486}, pmid = {25643359}, issn = {1932-6203}, mesh = {Adaptation, Physiological ; Amoeba/*microbiology ; Chlamydiales/genetics/growth &amp; development/*physiology ; Epithelial Cells/cytology/*microbiology ; *Evolution, Molecular ; Genomics ; Humans ; Intracellular Space/microbiology ; *Symbiosis ; *Temperature ; }, abstract = {Ancient chlamydiae diverged into pathogenic and environmental chlamydiae 0.7-1.4 billion years ago. However, how pathogenic chlamydiae adapted to mammalian cells that provide a stable niche at approximately 37 °C, remains unknown, although environmental chlamydiae have evolved as endosymbionts of lower eukaryotes in harsh niches of relatively low temperatures. Hence, we assessed whether an environmental chlamydia, Parachlamydia Bn9, could grow in human HEp-2 cells at a low culture temperature of 30 °C. The assessment of inclusion formation by quantitative RT-PCR revealed that the numbers of bacterial inclusion bodies and the transcription level of 16SrRNA significantly increased after culture at 30 °C compared to at 37 °C. Confocal microscopy showed that the bacteria were located close to HEp-2 nuclei and were actively replicative. Transmission electron microscopy also revealed replicating bacteria consisting of reticular bodies, but with a few elementary bodies. Cytochalasin D and rifampicin inhibited inclusion formation. Lactacystin slightly inhibited bacterial inclusion formation. KEGG analysis using a draft genome sequence of the bacteria revealed that it possesses metabolic pathways almost identical to those of pathogenic chlamydia. Interestingly, comparative genomic analysis with pathogenic chlamydia revealed that the Parachlamydia similarly possess the genes encoding Type III secretion system, but lacking genes encoding inclusion membrane proteins (IncA to G) required for inclusion maturation. Taken together, we conclude that ancient chlamydiae had the potential to grow in human cells, but overcoming the thermal gap was a critical event for chlamydial adaptation to human cells.}, }
@article {pmid25635695, year = {2015}, author = {Castelli, M and Lanzoni, O and Fokin, SI and Schrallhammer, M and Petroni, G}, title = {Response of the bacterial symbiont Holospora caryophila to different growth conditions of its host.}, journal = {European journal of protistology}, volume = {51}, number = {1}, pages = {98-108}, doi = {10.1016/j.ejop.2014.11.006}, pmid = {25635695}, issn = {1618-0429}, mesh = {Analysis of Variance ; Holosporaceae/*physiology ; Paramecium/growth &amp; development/*microbiology ; Symbiosis ; Time Factors ; }, abstract = {Previous studies on bacterial symbionts of ciliates have shown that some symbionts can be maintained relatively well under standard laboratory conditions whereas others are frequently lost, especially when the host is cultivated at a high division rate. In this study, the variation in infection level by the endosymbiont Holospora caryophila within its host population Paramecium octaurelia was investigated in response to three alimentary treatments and a subsequent starvation phase. The response of the ciliates was determined as a nearly exponential growth rate with different slopes in each treatment, proportional to the amount of food received. The initial infection level was higher than 90%. After 24 days of exponential host's growth, the prevalence remained stable at approximately 90% in all treatments, even after a subsequent starvation phase of 20 days. However, at intermediate time-points in both the feeding and the starvation phase, fluctuations in the presence of the intracellular bacteria were observed. These results show that H. caryophila is able to maintain its infection under the tested range of host growth conditions, also due to the possibility of an effective re-infection in case of partial loss.}, }
@article {pmid25632977, year = {2015}, author = {Masson, F and Vallier, A and Vigneron, A and Balmand, S and Vincent-Monégat, C and Zaidman-Rémy, A and Heddi, A}, title = {Systemic infection generates a local-like immune response of the bacteriome organ in insect symbiosis.}, journal = {Journal of innate immunity}, volume = {7}, number = {3}, pages = {290-301}, pmid = {25632977}, issn = {1662-8128}, mesh = {Animals ; Gene Expression Regulation, Bacterial/*immunology ; Gram-Negative Bacteria/*immunology ; Symbiosis/*immunology ; Weevils/*immunology/*microbiology ; }, abstract = {Endosymbiosis is common in insects thriving in nutritionally unbalanced habitats. The cereal weevil, Sitophilus oryzae, houses Sodalis pierantonius, a Gram-negative intracellular symbiotic bacterium (endosymbiont), within a dedicated organ called a bacteriome. Recent data have shown that the bacteriome expresses certain immune genes that result in local symbiont tolerance and control. Here, we address the question of whether and how the bacteriome responds to insect infections involving exogenous bacteria. We have established an infection model by challenging weevil larvae with the Gram-negative bacterium Dickeya dadantii. We showed that D. dadantii infects host tissues and triggers a systemic immune response. Gene transcript analysis indicated that the bacteriome is also immune responsive, but it expresses immune effector genes to a lesser extent than the systemic and intestinal responses. Most genes putatively involved in immune pathways remain weakly expressed in the bacteriome following D. dadantii infection. Moreover, quantitative PCR experiments showed that the endosymbiont load is not affected by insect infection or the resulting bacteriome immune activation. Thus, the contained immune effector gene expression in the bacteriome may prevent potentially harmful effects of the immune response on endosymbionts, whilst efficiently protecting them from bacterial intruders.}, }
@article {pmid25626393, year = {2015}, author = {Cass, BN and Yallouz, R and Bondy, EC and Mozes-Daube, N and Horowitz, AR and Kelly, SE and Zchori-Fein, E and Hunter, MS}, title = {Dynamics of the endosymbiont Rickettsia in an insect pest.}, journal = {Microbial ecology}, volume = {70}, number = {1}, pages = {287-297}, pmid = {25626393}, issn = {1432-184X}, mesh = {Animals ; DNA Primers/genetics ; Genetic Fitness/genetics ; *Genetic Variation ; Geography ; Hemiptera/*microbiology ; Insect Control/*methods ; *Introduced Species ; Israel ; Logistic Models ; Microsatellite Repeats/genetics ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*genetics ; Sex Ratio ; Southwestern United States ; *Symbiosis ; Time Factors ; }, abstract = {A new heritable bacterial association can bring a fresh set of molecular capabilities, providing an insect host with an almost instantaneous genome extension. Increasingly acknowledged as agents of rapid evolution, inherited microbes remain underappreciated players in pest management programs. A Rickettsia bacterium was tracked sweeping through populations of an invasive whitefly provisionally described as the "B" or "MEAM1" of the Bemisia tabaci species complex, in the southwestern USA. In this population, Rickettsia provides strong fitness benefits and distorts whitefly sex ratios under laboratory conditions. In contrast, whiteflies in Israel show few apparent fitness benefits from Rickettsia under laboratory conditions, only slightly decreasing development time. A survey of B. tabaci B samples revealed the distribution of Rickettsia across the cotton-growing regions of Israel and the USA. Thirteen sites from Israel and 22 sites from the USA were sampled. Across the USA, Rickettsia frequencies were heterogeneous among regions, but were generally very high, whereas in Israel, the infection rates were lower and declining. The distinct outcomes of Rickettsia infection in these two countries conform to previously reported phenotypic differences. Intermediate frequencies in some areas in both countries may indicate a cost to infection in certain environments or that the frequencies are in flux. This suggests underlying geographic differences in the interactions between bacterial symbionts and this serious agricultural pest.}, }
@article {pmid28362003, year = {2015}, author = {Zíková, A and Oborník, M and Lukeš, J}, title = {Fancy a gene? A surprisingly complex evolutionary history of peroxiredoxins.}, journal = {Microbial cell (Graz, Austria)}, volume = {2}, number = {2}, pages = {33-37}, pmid = {28362003}, issn = {2311-2638}, abstract = {While the phylum Apicomplexa includes "only" several thousand described species of obligatory parasites of animals, it may in fact be the most specious group of parasitic protists with over a million species 1. The best known representatives are Plasmodium spp., Toxoplasma gondii and Cryptosporidium spp., which belong to the most important and widespread human parasites exacting an enormous disease burden. On the other hand, dinoflagellates and colpodellids, which are monophyletic with the apicomplexans, are ecologically highly significant, as they belong to the most abundant marine protists 2. As the common ancestor of these groups was most likely a free-living photosynthesizing protist, one wonders, which evolutionary forces contributed to the dramatic transition of some of its descendants into the arguably most successful intracellular parasites? Although a range of various processes and mechanisms contributed to this transition, most likely it also involved an acquisition of genes via horizontal gene transfer (HGT), which might have provided typical characteristics of a parasitic cell, such as immune escape, nutritional dependence and the capacity to invade other cells.}, }
@article {pmid25618142, year = {2015}, author = {Smith, TA and Driscoll, T and Gillespie, JJ and Raghavan, R}, title = {A Coxiella-like endosymbiont is a potential vitamin source for the Lone Star tick.}, journal = {Genome biology and evolution}, volume = {7}, number = {3}, pages = {831-838}, pmid = {25618142}, issn = {1759-6653}, support = {R01 AI017828/AI/NIAID NIH HHS/United States ; R01 AI043006/AI/NIAID NIH HHS/United States ; R01AI017828/AI/NIAID NIH HHS/United States ; R01AI043006/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Coxiella/*classification/genetics/isolation &amp; purification/metabolism ; Coxiella burnetii/classification ; Genome, Bacterial ; Ixodidae/*microbiology ; Phylogeny ; *Symbiosis ; Virulence/genetics ; Vitamins/*biosynthesis ; }, abstract = {Amblyomma americanum (Lone star tick) is an important disease vector in the United States. It transmits several human pathogens, including the agents of human monocytic ehrlichiosis, tularemia, and southern tick-associated rash illness. Blood-feeding insects (Class Insecta) depend on bacterial endosymbionts to provide vitamins and cofactors that are scarce in blood. It is unclear how this deficiency is compensated in ticks (Class Arachnida) that feed exclusively on mammalian blood. A bacterium related to Coxiella burnetii, the agent of human Q fever, has been observed previously within cells of A. americanum. Eliminating this bacterium (CLEAA, Coxiella-like endosymbiont of A. americanum) with antibiotics reduced tick fecundity, indicating that it is an essential endosymbiont. In an effort to determine its role within this symbiosis, we sequenced the CLEAA genome. While highly reduced (656,901 bp) compared with C. burnetii (1,995,281 bp), the CLEAA genome encodes most major vitamin and cofactor biosynthesis pathways, implicating CLEAA as a vitamin provisioning endosymbiont. In contrast, CLEAA lacks any recognizable virulence genes, indicating that it is not a pathogen despite its presence in tick salivary glands. As both C. burnetii and numerous "Coxiella-like bacteria" have been reported from several species of ticks, we determined the evolutionary relationship between the two bacteria. Phylogeny estimation revealed that CLEAA is a close relative of C. burnetii, but was not derived from it. Our results are important for strategies geared toward controlling A. americanum and the pathogens it vectors, and also contribute novel information regarding the metabolic interdependencies of ticks and their nutrient-provisioning endosymbionts.}, }
@article {pmid25614577, year = {2015}, author = {Tushar, L and Sravanthi, T and Sasikala, C and Ramana, CV}, title = {Draft Genome Sequence of Spirochaeta sp. Strain JC202, an Endosymbiont of the Termite (Isoptera) Gut.}, journal = {Genome announcements}, volume = {3}, number = {1}, pages = {}, pmid = {25614577}, issn = {2169-8287}, abstract = {We announce here the draft genome sequence of Spirochaeta sp. strain JC202 isolated from gut of a termite (Isoptera). The genome suggests that Spirochaeta sp. JC202 has the capability for natural conjugation with the help of fimbriae and pili. Experimental evidence and the genome sequence suggest that strain JC202 is capable of producing colicin V and a bacteriocin group of peptides in a specific interaction.}, }
@article {pmid25614557, year = {2015}, author = {Horn, F and Üzüm, Z and Möbius, N and Guthke, R and Linde, J and Hertweck, C}, title = {Draft Genome Sequences of Symbiotic and Nonsymbiotic Rhizopus microsporus Strains CBS 344.29 and ATCC 62417.}, journal = {Genome announcements}, volume = {3}, number = {1}, pages = {}, pmid = {25614557}, issn = {2169-8287}, abstract = {Specific Rhizopus microsporus pathovars harbor bacterial endosymbionts (Burkholderia rhizoxinica) for the production of a phytotoxin. Here, we present the draft genome sequences of two R. microsporus strains, one symbiotic (ATCC 62417), and one endosymbiont-free (CBS 344.29). The gene predictions were supported by RNA sequencing (RNA-seq) data. The functional annotation sets the basis for comparative analyses.}, }
@article {pmid25613091, year = {2015}, author = {White, JA and Richards, NK and Laugraud, A and Saeed, A and Curry, MM and McNeill, MR}, title = {Endosymbiotic candidates for parasitoid defense in exotic and native New Zealand weevils.}, journal = {Microbial ecology}, volume = {70}, number = {1}, pages = {274-286}, pmid = {25613091}, issn = {1432-184X}, mesh = {Animals ; Base Sequence ; DNA Primers/genetics ; Geography ; Likelihood Functions ; Metagenomics ; Models, Genetic ; Molecular Sequence Data ; New Zealand ; Phylogeny ; Polymerase Chain Reaction ; Rickettsia/*genetics ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Weevils/*microbiology ; Wolbachia/*genetics ; }, abstract = {Some insects are infected with maternally inherited bacterial endosymbionts that protect them against pathogens or parasitoids. The weevil Sitona obsoletus (=Sitona lepidus) is invasive in New Zealand, and suspected to contain such defensive symbionts, because it is particularly resistant to a Moroccan strain of the parasitoid Microctonus aethiopoides (which successfully attacks many other weevil species), and shows geographic variation in susceptibility to an Irish strain of the same parasitoid. Using 454 pyrosequencing, we investigated the bacterial community associated with S. obsoletus, two other exotic weevils (Sitona discoideus and Listronotus bonariensis) and two endemic New Zealand weevils (Irenimus aequalis and Steriphus variabilis). We found that S. obsoletus was infected by one strain of Wolbachia and two strains of Rickettsia, none of which were found in any other weevil species examined. Using diagnostic PCR, we found that S. obsoletus in the Northland region, where parasitism is highly variable, were primarily infected with Wolbachia and Rickettsia strain 2, indicating that these two symbionts should be investigated for potential defensive properties. In comparison, S. discoideus lacked any apparent maternally inherited bacterial endosymbionts. In the other weevil species, we found a different strain of Wolbachia and two different strains of Spiroplasma. Two weevil species (St. variabilis and L. bonariensis) were infected with distinct strains of Nardonella, the ancestral endosymbiont of weevils, whereas three weevil species (S. obsoletus, S. discoideus, and I. aequalis) lacked evidence for Nardonella infection. However, I. aequalis was consistently infected with a novel Enterobacteriaceae strain, suggesting that a symbiont replacement may have taken place, similar to that described for other weevil clades.}, }
@article {pmid25610432, year = {2014}, author = {Martínez-Cano, DJ and Reyes-Prieto, M and Martínez-Romero, E and Partida-Martínez, LP and Latorre, A and Moya, A and Delaye, L}, title = {Evolution of small prokaryotic genomes.}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {742}, pmid = {25610432}, issn = {1664-302X}, abstract = {As revealed by genome sequencing, the biology of prokaryotes with reduced genomes is strikingly diverse. These include free-living prokaryotes with ∼800 genes as well as endosymbiotic bacteria with as few as ∼140 genes. Comparative genomics is revealing the evolutionary mechanisms that led to these small genomes. In the case of free-living prokaryotes, natural selection directly favored genome reduction, while in the case of endosymbiotic prokaryotes neutral processes played a more prominent role. However, new experimental data suggest that selective processes may be at operation as well for endosymbiotic prokaryotes at least during the first stages of genome reduction. Endosymbiotic prokaryotes have evolved diverse strategies for living with reduced gene sets inside a host-defined medium. These include utilization of host-encoded functions (some of them coded by genes acquired by gene transfer from the endosymbiont and/or other bacteria); metabolic complementation between co-symbionts; and forming consortiums with other bacteria within the host. Recent genome sequencing projects of intracellular mutualistic bacteria showed that previously believed universal evolutionary trends like reduced G+C content and conservation of genome synteny are not always present in highly reduced genomes. Finally, the simplified molecular machinery of some of these organisms with small genomes may be used to aid in the design of artificial minimal cells. Here we review recent genomic discoveries of the biology of prokaryotes endowed with small gene sets and discuss the evolutionary mechanisms that have been proposed to explain their peculiar nature.}, }
@article {pmid25609566, year = {2015}, author = {Wang, Z and Wu, M}, title = {An integrated phylogenomic approach toward pinpointing the origin of mitochondria.}, journal = {Scientific reports}, volume = {5}, number = {}, pages = {7949}, pmid = {25609566}, issn = {2045-2322}, mesh = {Alphaproteobacteria/genetics ; *Evolution, Molecular ; Genomics ; Mitochondria/*genetics ; *Phylogeny ; Rickettsiaceae/*genetics ; Symbiosis/genetics ; }, abstract = {Overwhelming evidence supports the endosymbiosis theory that mitochondria originated once from the Alphaproteobacteria. However, its exact position in the tree of life remains highly debated. This is because systematic errors, including biased taxonomic sampling, high evolutionary rates and sequence composition bias have long plagued the mitochondrial phylogenetics. In this study, we address this issue by 1) increasing the taxonomic representation of alphaproteobacterial genomes by sequencing 18 phylogenetically novel species. They include 5 Rickettsiales and 4 Rhodospirillales, two orders that have shown close affiliations with mitochondria previously, 2) using a set of 29 slowly evolving mitochondria-derived nuclear genes that are less biased than mitochondria-encoded genes as the alternative "well behaved" markers for phylogenetic analysis, 3) applying site heterogeneous mixture models that account for the sequence composition bias. With the integrated phylogenomic approach, we are able to for the first time place mitochondria unequivocally within the Rickettsiales order, as a sister clade to the Rickettsiaceae and Anaplasmataceae families, all subtended by the Holosporaceae family. Our results suggest that mitochondria most likely originated from a Rickettsiales endosymbiont already residing in the host, but not from the distantly related free-living Pelagibacter and Rhodospirillales.}, }
@article {pmid25609551, year = {2014}, author = {Xue, J and Zhou, X and Zhang, CX and Yu, LL and Fan, HW and Wang, Z and Xu, HJ and Xi, Y and Zhu, ZR and Zhou, WW and Pan, PL and Li, BL and Colbourne, JK and Noda, H and Suetsugu, Y and Kobayashi, T and Zheng, Y and Liu, S and Zhang, R and Liu, Y and Luo, YD and Fang, DM and Chen, Y and Zhan, DL and Lv, XD and Cai, Y and Wang, ZB and Huang, HJ and Cheng, RL and Zhang, XC and Lou, YH and Yu, B and Zhuo, JC and Ye, YX and Zhang, WQ and Shen, ZC and Yang, HM and Wang, J and Wang, J and Bao, YY and Cheng, JA}, title = {Genomes of the rice pest brown planthopper and its endosymbionts reveal complex complementary contributions for host adaptation.}, journal = {Genome biology}, volume = {15}, number = {12}, pages = {521}, pmid = {25609551}, issn = {1474-760X}, mesh = {Adaptation, Biological ; Animals ; Arthropods/genetics ; Asia ; Bacteria/genetics ; Evolution, Molecular ; *Genome, Insect ; Genomics ; Hemiptera/*genetics/*microbiology/physiology ; *Herbivory ; Host Specificity ; Molecular Sequence Data ; Multigene Family ; Oryza/*physiology ; Phylogeny ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {BACKGROUND: The brown planthopper, Nilaparvata lugens, the most destructive pest of rice, is a typical monophagous herbivore that feeds exclusively on rice sap, which migrates over long distances. Outbreaks of it have re-occurred approximately every three years in Asia. It has also been used as a model system for ecological studies and for developing effective pest management. To better understand how a monophagous sap-sucking arthropod herbivore has adapted to its exclusive host selection and to provide insights to improve pest control, we analyzed the genomes of the brown planthopper and its two endosymbionts.<br><br>RESULTS: We describe the 1.14 gigabase planthopper draft genome and the genomes of two microbial endosymbionts that permit the planthopper to forage exclusively on rice fields. Only 40.8% of the 27,571 identified Nilaparvata protein coding genes have detectable shared homology with the proteomes of the other 14 arthropods included in this study, reflecting large-scale gene losses including in evolutionarily conserved gene families and biochemical pathways. These unique genomic features are functionally associated with the animal's exclusive plant host selection. Genes missing from the insect in conserved biochemical pathways that are essential for its survival on the nutritionally imbalanced sap diet are present in the genomes of its microbial endosymbionts, which have evolved to complement the mutualistic nutritional needs of the host.<br><br>CONCLUSIONS: Our study reveals a series of complex adaptations of the brown planthopper involving a variety of biological processes, that result in its highly destructive impact on the exclusive host rice. All these findings highlight potential directions for effective pest control of the planthopper.}, }
@article {pmid25596450, year = {2015}, author = {Chi, W and He, B and Mao, J and Jiang, J and Zhang, L}, title = {Plastid sigma factors: Their individual functions and regulation in transcription.}, journal = {Biochimica et biophysica acta}, volume = {1847}, number = {9}, pages = {770-778}, doi = {10.1016/j.bbabio.2015.01.001}, pmid = {25596450}, issn = {0006-3002}, mesh = {Plastids/*physiology ; Promoter Regions, Genetic ; Sigma Factor/*physiology ; *Transcription, Genetic ; }, abstract = {Sigma factors are the predominant factors involved in transcription regulation in bacteria. These factors can recruit the core RNA polymerase to promoters with specific DNA sequences and initiate gene transcription. The plastids of higher plants originating from an ancestral cyanobacterial endosymbiont also contain sigma factors that are encoded by a small family of nuclear genes. Although all plastid sigma factors contain sequences conserved in bacterial sigma factors, a considerable number of distinct traits have been acquired during evolution. The present review summarises recent advances concerning the regulation of the structure, function and activity of plastid sigma factors since their discovery nearly 40 years ago. We highlight the specialised roles and overlapping redundant functions of plastid sigma factors according to their promoter selectivity. We also focus on the mechanisms that modulate the activity of sigma factors to optimise plastid function in response to developmental cues and environmental signals. This article is part of a Special Issue entitled: Chloroplast Biogenesis.}, }
@article {pmid25586575, year = {2015}, author = {Ramírez-Bahena, MH and Vargas, M and Martín, M and Tejedor, C and Velázquez, E and Peix, &#xc1;}, title = {Alfalfa microsymbionts from different ITS and nodC lineages of Ensifer meliloti and Ensifer medicae symbiovar meliloti establish efficient symbiosis with alfalfa in Spanish acid soils.}, journal = {Applied microbiology and biotechnology}, volume = {99}, number = {11}, pages = {4855-4865}, doi = {10.1007/s00253-014-6347-6}, pmid = {25586575}, issn = {1432-0614}, mesh = {Acids/analysis ; Bacterial Proteins/*genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/*genetics ; Medicago sativa/*microbiology ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases/*genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Random Amplified Polymorphic DNA Technique ; Sequence Analysis, DNA ; Sinorhizobium/classification/genetics/*isolation &amp; purification/*physiology ; Soil/chemistry ; *Soil Microbiology ; Spain ; *Symbiosis ; }, abstract = {Alfalfa (Medicago sativa L.) is an important crop worldwide whose cropping in acid soils is hampered by the poor nodulation and yield commonly attributed to the sensitivity of its endosymbionts to acid pH. In this work, we isolated several acid-tolerant strains from alfalfa nodules in three acid soils in northwestern Spain. After grouping by RAPD fingerprinting, most strains were identified as Ensifer meliloti and only two strains as Ensifer medicae according to their 16S-23S intergenic spacer (ITS) sequences that allowed the differentiation of two groups within each one of these species. The two ITS groups of E. meliloti and the ITS group I of E. medicae have been previously found in Medicago nodules; however, the group II of E. medicae has been only found to date in Prosopis alba nodules. The analysis of the nodC gene showed that all strains isolated in this study belong to the symbiovar meliloti, grouping with the type strains of E. meliloti or E. medicae, but some harboured nodC gene alleles different from those found to date in alfalfa nodules. The strains of E. medicae belong to the symbiovar meliloti which should be also recognised in this species, although they harboured a nodC allele phylogenetically divergent to those from E. meliloti strains. Microcosm experiments showed that inoculation of alfalfa with selected acid-tolerant strains significantly increased yields in acid soils representing a suitable agricultural practice for alfalfa cropping in these soils.}, }
@article {pmid25580379, year = {2014}, author = {Aksoy, S and Weiss, BL and Attardo, GM}, title = {Trypanosome Transmission Dynamics in Tsetse.}, journal = {Current opinion in insect science}, volume = {3}, number = {}, pages = {43-49}, pmid = {25580379}, issn = {2214-5745}, support = {R01 AI081774/AI/NIAID NIH HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; F32 AI062680/AI/NIAID NIH HHS/United States ; F32 GM077964/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R21 AI101456/AI/NIAID NIH HHS/United States ; }, abstract = {Tsetse flies (Diptera:Glossinidae) are vectors of African trypanosomes. Tsetse undergo viviparous reproductive biology, and depend on their obligate endosymbiont (genus Wigglesworthia) for the maintenance of fecundity and immune system development. Trypanosomes establish infections in the midgut and salivary glands of the fly. Tsetse's resistance to trypanosome infection increases as a function of age. Among the factors that mediate resistance to parasites are antimicrobial peptides (AMPs) produced by the Immune deficiency (Imd) signaling pathway, peptidoglycan recognition protein (PGRP) LB, tsetse-EP protein and the integrity of the midgut peritrophic matrix (PM) barrier. The presence of obligate Wigglesworthia during larval development is essential for adult immune system maturation and PM development. Thus, Wigglesworthia prominently influences the vector competency of it's tsetse host.}, }
@article {pmid25579393, year = {2015}, author = {Voronin, D and Abeykoon, AM and Gunawardene, YI and Dassanayake, RS}, title = {Absence of Wolbachia endobacteria in Sri Lankan isolates of the nematode parasite of animals Setaria digitata.}, journal = {Veterinary parasitology}, volume = {207}, number = {3-4}, pages = {350-354}, doi = {10.1016/j.vetpar.2014.12.024}, pmid = {25579393}, issn = {1873-2550}, mesh = {Animals ; Cattle/parasitology ; Genes, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Setaria Nematode/*microbiology ; Sri Lanka ; Wolbachia/genetics/*physiology ; }, abstract = {Setaria digitata is an animal filarial parasite with natural hosts of cattle and buffaloes that causes mild disease conditions. Infection of non-permissive hosts such as goats, sheep and horses, by this nematode can cause cerebrospinal nematodiasis that leads to lumbar paralysis and the eventual death of the animals and inflicts considerable economic losses on livestock farmers. Wolbachia are obligate mutualistic endosymbionts for some filarial nematodes and are currently being targeted for the control of diseases caused by these parasites. However, little is known about the occurrence of this endosymbiont in the Setariidae family. In this work, worms collected from infected cattle in Sri Lanka were morphologically identified as S. digitata and tested for the presence of Wolbachia by PCR screening using the WSP- and Wolbachia-specific 16S rRNA and multilocus sequence typing primers that were designed to amplify the gatB, coxA, hcpA, ftsZ and fbpA sequences of Wolbachia. The presence of endobacteria in S. digitata was also examined by whole-mount immunofluorescence staining of the parasites and transmission electron microscopic studies. These analyses did not produce evidence of presence of Wolbachia or any other endosymbiotic bacteria in S. digitata, whereas such evidence was found in Brugia malayi, which was used as a positive control in this study.}, }
@article {pmid25564461, year = {2015}, author = {Bongaerts, P and Frade, PR and Hay, KB and Englebert, N and Latijnhouwers, KR and Bak, RP and Vermeij, MJ and Hoegh-Guldberg, O}, title = {Deep down on a Caribbean reef: lower mesophotic depths harbor a specialized coral-endosymbiont community.}, journal = {Scientific reports}, volume = {5}, number = {}, pages = {7652}, pmid = {25564461}, issn = {2045-2322}, mesh = {Animals ; Anthozoa/classification/*genetics/growth &amp; development ; Caribbean Region ; Coral Reefs ; Ecosystem ; Genetic Variation ; Genotype ; Mitochondria/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal/chemistry/genetics/metabolism ; Symbiosis/genetics ; Temperature ; }, abstract = {The composition, ecology and environmental conditions of mesophotic coral ecosystems near the lower limits of their bathymetric distributions remain poorly understood. Here we provide the first in-depth assessment of a lower mesophotic coral community (60-100 m) in the Southern Caribbean through visual submersible surveys, genotyping of coral host-endosymbiont assemblages, temperature monitoring and a growth experiment. The lower mesophotic zone harbored a specialized coral community consisting of predominantly Agaricia grahamae, Agaricia undata and a "deep-water" lineage of Madracis pharensis, with large colonies of these species observed close to their lower distribution limit of ~90 m depth. All three species associated with "deep-specialist" photosynthetic endosymbionts (Symbiodinium). Fragments of A. grahamae exhibited growth rates at 60 m similar to those observed for shallow Agaricia colonies (~2-3 cm yr(-1)), but showed bleaching and (partial) mortality when transplanted to 100 m. We propose that the strong reduction of temperature over depth (Δ5°C from 40 to 100 m depth) may play an important contributing role in determining lower depth limits of mesophotic coral communities in this region. Rather than a marginal extension of the reef slope, the lower mesophotic represents a specialized community, and as such warrants specific consideration from science and management.}, }
@article {pmid25563918, year = {2015}, author = {Kurtti, TJ and Felsheim, RF and Burkhardt, NY and Oliver, JD and Heu, CC and Munderloh, UG}, title = {Rickettsia buchneri sp. nov., a rickettsial endosymbiont of the blacklegged tick Ixodes scapularis.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {65}, number = {Pt 3}, pages = {965-970}, pmid = {25563918}, issn = {1466-5034}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI081690/AI/NIAID NIH HHS/United States ; R01 AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Typing Techniques ; DNA, Bacterial/genetics ; Female ; Genes, Bacterial ; Ixodes/*microbiology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Ovary/microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/genetics/isolation &amp; purification ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {We obtained a rickettsial isolate from the ovaries of the blacklegged tick, Ixodes scapularis. The isolate (ISO7(T)) was grown in the Ixodes ricinus embryonic cell line IRE11. We characterized the isolate by transmission electron microscopy and gene sequencing. Phylogenetic analysis of 11 housekeeping genes demonstrated that the isolate fulfils the criteria to be classified as a representative of a novel rickettsial species closely related to 'Rickettsia monacensis'. These rickettsiae form a clade separate from other species of rickettsiae. Gene sequences indicated that several genes important in rickettsial motility, invasiveness and temperature adaptation were mutated (e.g. sca2, rickA, hsp22, pldA and htrA). We propose the name Rickettsia buchneri sp. nov. for this bacterium that infects the ovaries of the tick I. scapularis to acknowledge the pioneering contributions of Professor Paul Buchner (1886-1978) to research on bacterial symbionts. The type strain of R. buchneri sp. nov. is strain ISO-7(T) (= DSM 29016(T) = ATCC VR-1814(T)).}, }
@article {pmid25561714, year = {2015}, author = {Peña, JM and Carrillo, MA and Hallem, EA}, title = {Variation in the susceptibility of Drosophila to different entomopathogenic nematodes.}, journal = {Infection and immunity}, volume = {83}, number = {3}, pages = {1130-1138}, pmid = {25561714}, issn = {1098-5522}, support = {R25 GM055052/GM/NIGMS NIH HHS/United States ; R25GM055052/GM/NIGMS NIH HHS/United States ; //Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Antimicrobial Cationic Peptides/*biosynthesis ; Drosophila/*immunology/parasitology ; Drosophila melanogaster/*immunology/parasitology ; Host Specificity ; Host-Parasite Interactions ; Larva/growth &amp; development/metabolism/microbiology/pathogenicity ; Longevity/immunology ; Nematoda/growth &amp; development/metabolism/microbiology/*pathogenicity ; Species Specificity ; Symbiosis ; Time Factors ; Virulence ; Xenorhabdus ; }, abstract = {Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.}, }
@article {pmid25561505, year = {2015}, author = {Weston, AJ and Dunlap, WC and Beltran, VH and Starcevic, A and Hranueli, D and Ward, M and Long, PF}, title = {Proteomics links the redox state to calcium signaling during bleaching of the scleractinian coral Acropora microphthalma on exposure to high solar irradiance and thermal stress.}, journal = {Molecular &amp; cellular proteomics : MCP}, volume = {14}, number = {3}, pages = {585-595}, pmid = {25561505}, issn = {1535-9484}, support = {BB/H010009/2//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Algal Proteins/analysis ; Animals ; Anthozoa/*physiology/radiation effects ; *Calcium Signaling ; Cyanobacteria/*physiology ; Gene Expression Regulation ; *Oxidation-Reduction ; Photosynthesis ; Proteomics/*methods ; Skin Lightening Preparations ; *Stress, Physiological ; Sunlight ; Symbiosis ; Temperature ; }, abstract = {Shipboard experiments were each performed over a 2 day period to examine the proteomic response of the symbiotic coral Acropora microphthalma exposed to acute conditions of high temperature/low light or high light/low temperature stress. During these treatments, corals had noticeably bleached. The photosynthetic performance of residual algal endosymbionts was severely impaired but showed signs of recovery in both treatments by the end of the second day. Changes in the coral proteome were determined daily and, using recently available annotated genome sequences, the individual contributions of the coral host and algal endosymbionts could be extracted from these data. Quantitative changes in proteins relevant to redox state and calcium metabolism are presented. Notably, expression of common antioxidant proteins was not detected from the coral host but present in the algal endosymbiont proteome. Possible roles for elevated carbonic anhydrase in the coral host are considered: to restore intracellular pH diminished by loss of photosynthetic activity, to indirectly limit intracellular calcium influx linked with enhanced calmodulin expression to impede late-stage symbiont exocytosis, or to enhance inorganic carbon transport to improve the photosynthetic performance of algal symbionts that remain in hospite. Protein effectors of calcium-dependent exocytosis were present in both symbiotic partners. No caspase-family proteins associated with host cell apoptosis, with exception of the autophagy chaperone HSP70, were detected, suggesting that algal loss and photosynthetic dysfunction under these experimental conditions were not due to host-mediated phytosymbiont destruction. Instead, bleaching occurred by symbiont exocytosis and loss of light-harvesting pigments of algae that remain in hospite. These proteomic data are, therefore, consistent with our premise that coral endosymbionts can mediate their own retention or departure from the coral host, which may manifest as "symbiont shuffling" of Symbiodinium clades in response to environmental stress.}, }
@article {pmid27048094, year = {2015}, author = {Napora, A and Kacprzak, M and Nowak, K and Grobelak, A}, title = {[Influence endophytic bacteria to promote plants growth in stress conditions].}, journal = {Postepy biochemii}, volume = {61}, number = {4}, pages = {398-402}, pmid = {27048094}, issn = {0032-5422}, mesh = {*Bacterial Physiological Phenomena ; Endophytes/*physiology ; *Plant Development ; Plant Growth Regulators ; Plant Roots/*microbiology ; Plants ; *Stress, Physiological ; }, abstract = {The growth of plants under stress conditions is often assisted by microorganisms colonizing the rhizosphere (the root zone of the highest microbial activity). One of the most important bacterial groups to encourage the growth of plants (PGPB) are endophytes. These microorganisms penetrate living cells of plants and there they lead the microbiological activity as endosymbionts. These microorganisms can effectively promote the growth of plants under stress conditions and stimulate biochemical activities: nitrogen fixation, production of growth hormones (auxins, cytokinins and gibberellins), reduction of the high concentration of ethylene as well as facilitation of the collection plant minerals and water. This paper is an attempt to summarize the current state of knowledge about the biochemical activity of bacterial endophytes.}, }
@article {pmid25541519, year = {2015}, author = {Glowska, E and Dragun-Damian, A and Dabert, M and Gerth, M}, title = {New Wolbachia supergroups detected in quill mites (Acari: Syringophilidae).}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {30}, number = {}, pages = {140-146}, doi = {10.1016/j.meegid.2014.12.019}, pmid = {25541519}, issn = {1567-7257}, mesh = {Animals ; Birds/*parasitology ; DNA, Bacterial/analysis/genetics ; Feathers/*parasitology ; Female ; Male ; Mites/*microbiology ; Phylogeny ; Symbiosis ; *Wolbachia/classification/genetics/isolation &amp; purification ; }, abstract = {Wolbachia is the most abundant intracellular bacterial genus infecting a wide range of arthropods and filarial nematodes. Wolbachia have evolved parasitic, mutualistic and commensal relationships with their hosts but in arthropods generally act as reproductive parasites, inducing a wide range of phenotypic effects such as cytoplasmic incompatibility, parthenogenesis, feminization and male-killing. Up to now, the genus has been divided into 14 supergroups successively named A-O. Here, we describe two new Wolbachia supergroups from syringophilid mites (Acari: Cheyletoidea). These obligatory ectoparasites of birds inhabit the quills of feathers in many avian groups. The species of this family reproduce in a haplodiploid mode sensu arrhenotoky and are usually strongly female-biased. Based on the sequences of four protein-coding genes (ftsZ, gltA and groEL and coxA) and the 16S rRNA we identified strains of three Wolbachia supergroups (F and two distinct, yet undescribed ones) in five quill mite species. Our results suggest that in some cases the distribution of the bacteria can be better correlated with the mite's bird host rather than with mite taxonomy as such. The discovery of two new Wolbachia supergroups not only broadens the knowledge of the diversity of this bacterium but also raises questions about potential effects induced in quill mites and transmission mechanisms of the endosymbionts in this peculiar bacteria-quill mite-bird system.}, }
@article {pmid25540451, year = {2015}, author = {Wertheim, JO and Murrell, B and Smith, MD and Kosakovsky Pond, SL and Scheffler, K}, title = {RELAX: detecting relaxed selection in a phylogenetic framework.}, journal = {Molecular biology and evolution}, volume = {32}, number = {3}, pages = {820-832}, pmid = {25540451}, issn = {1537-1719}, support = {K24 AI100665/AI/NIAID NIH HHS/United States ; U54 HL108460/HL/NHLBI NIH HHS/United States ; U54HL108460/HL/NHLBI NIH HHS/United States ; GM093939/GM/NIGMS NIH HHS/United States ; R01 GM093939/GM/NIGMS NIH HHS/United States ; DP1 DA034978/DA/NIDA NIH HHS/United States ; DA034978/DA/NIDA NIH HHS/United States ; K01 AI110181/AI/NIAID NIH HHS/United States ; U01 GM110749/GM/NIGMS NIH HHS/United States ; AI090970/AI/NIAID NIH HHS/United States ; U19 AI090970/AI/NIAID NIH HHS/United States ; AI110181/AI/NIAID NIH HHS/United States ; U01GM110749/GM/NIGMS NIH HHS/United States ; P30 AI036214/AI/NIAID NIH HHS/United States ; AI100665/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bornaviridae/genetics ; Chiroptera/genetics ; Codon/*genetics ; Computational Biology/*methods ; Computer Simulation ; Daphnia/genetics ; *Evolution, Molecular ; Gammaproteobacteria/genetics ; *Models, Genetic ; Opsins/genetics ; Phylogeny ; Selection, Genetic/*genetics ; Sequence Analysis, DNA ; }, abstract = {Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative γ-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional medium/long-wavelength sensitive opsin, M/LWS1, is found to be relaxed in all echolocating bats compared with nonecholocating bats.}, }
@article {pmid25538100, year = {2014}, author = {Enders, LS and Bickel, RD and Brisson, JA and Heng-Moss, TM and Siegfried, BD and Zera, AJ and Miller, NJ}, title = {Abiotic and biotic stressors causing equivalent mortality induce highly variable transcriptional responses in the soybean aphid.}, journal = {G3 (Bethesda, Md.)}, volume = {5}, number = {2}, pages = {261-270}, pmid = {25538100}, issn = {2160-1836}, mesh = {Animals ; Aphids/*genetics ; Genes, Insect ; Sequence Analysis, RNA ; Stress, Physiological/*genetics ; Transcriptome ; }, abstract = {Environmental stress affects basic organismal functioning and can cause physiological, developmental, and reproductive impairment. However, in many nonmodel organisms, the core molecular stress response remains poorly characterized and the extent to which stress-induced transcriptional changes differ across qualitatively different stress types is largely unexplored. The current study examines the molecular stress response of the soybean aphid (Aphis glycines) using RNA sequencing and compares transcriptional responses to multiple stressors (heat, starvation, and plant defenses) at a standardized stress level (27% adult mortality). Stress-induced transcriptional changes showed remarkable variation, with starvation, heat, and plant defensive stress altering the expression of 3985, 510, and 12 genes, respectively. Molecular responses showed little overlap across all three stressors. However, a common transcriptional stress response was identified under heat and starvation, involved with up-regulation of glycogen biosynthesis and molecular chaperones and down-regulation of bacterial endosymbiont cellular and insect cuticular components. Stressor-specific responses indicated heat affected expression of heat shock proteins and cuticular components, whereas starvation altered a diverse set of genes involved in primary metabolism, oxidative reductive processes, nucleosome and histone assembly, and the regulation of DNA repair and replication. Exposure to host plant defenses elicited the weakest response, of which half of the genes were of unknown function. This study highlights the need for standardizing stress levels when comparing across stress types and provides a basis for understanding the role of general vs. stressor specific molecular responses in aphids.}, }
@article {pmid25530287, year = {2015}, author = {Uzum, Z and Silipo, A and Lackner, G and De Felice, A and Molinaro, A and Hertweck, C}, title = {Structure, genetics and function of an exopolysaccharide produced by a bacterium living within fungal hyphae.}, journal = {Chembiochem : a European journal of chemical biology}, volume = {16}, number = {3}, pages = {387-392}, doi = {10.1002/cbic.201402488}, pmid = {25530287}, issn = {1439-7633}, mesh = {Bacterial Proteins/genetics ; Burkholderia/chemistry/genetics/*physiology ; Carbohydrate Sequence ; Hyphae/physiology ; Magnetic Resonance Spectroscopy ; Molecular Sequence Data ; Multigene Family ; Mutation ; Phylogeny ; Polysaccharides, Bacterial/*chemistry/*genetics/*metabolism ; Rhizopus/*physiology ; Symbiosis ; }, abstract = {The rice seedling blight fungus Rhizopus microsporus has an unusual symbiosis with a bacterium, Burkholderia rhizoxinica, which lives within the fungal cytosol and produces a potent phytotoxin that causes severe losses in agriculture. To gain insight into symbiosis factors we investigated the endosymbiont's exopolysaccharide (EPS), a secreted matrix that plays pivotal roles in mediating cell-environment interactions. By a combination of homo- and heteronuclear 2D NMR experiments, we elucidated a previously unknown EPS structure: a repeating tetrasaccharide unit bearing a nonstoichiometric acetyl group on a mannose residue. We also analyzed the EPS biosynthesis gene cluster and generated a targeted mutant to compare the phenotypes. Scanning electron microscope images revealed a reduced ability of the mutant to form extracellular polymers around cell aggregates. Phylogenetic analyses suggest that the symbiont's EPS genes are retained through evolutionary processes.}, }
@article {pmid25527583, year = {2014}, author = {Wamwiri, FN and Ndungu, K and Thande, PC and Thungu, DK and Auma, JE and Ngure, RM}, title = {Infection with the secondary tsetse-endosymbiont Sodalis glossinidius (Enterobacteriales: Enterobacteriaceae) influences parasitism in Glossina pallidipes (Diptera: Glossinidae).}, journal = {Journal of insect science (Online)}, volume = {14}, number = {}, pages = {}, pmid = {25527583}, issn = {1536-2442}, mesh = {Animals ; Enterobacteriaceae/*physiology ; Insect Vectors/*microbiology/*physiology ; Male ; Species Specificity ; Symbiosis ; Trypanosoma/*physiology ; Trypanosoma brucei brucei/physiology ; Trypanosoma brucei rhodesiense/physiology ; Trypanosoma congolense/physiology ; Tsetse Flies/*microbiology/*parasitology ; }, abstract = {The establishment of infection with three Trypanosoma spp (Gruby) (Kinetoplastida: Trypanosomatidae), specifically Trypanosoma brucei brucei (Plimmer and Bradford), T. b. rhodesiense (Stephen and Fatham) and T. congolense (Broden) was evaluated in Glossina pallidipes (Austen) (Diptera: Glossinidae) that either harbored or were uninfected by the endosymbiont Sodalis glossinidius (Dale and Maudlin) (Enterobacteriales: Enterobacteriaceae). Temporal variation of co-infection with T. b. rhodesiense and S. glossinidius was also assessed. The results show that both S. glossinidius infection (χ(2)= 1.134, df = 2, P = 0.567) and trypanosome infection rate (χ(2)= 1.85, df = 2, P = 0.397) were comparable across the three infection groups. A significant association was observed between the presence of S. glossinidius and concurrent trypanosome infection with T. b. rhodesiense (P = 0.0009) and T. congolense (P = 0.0074) but not with T. b. brucei (P = 0.5491). The time-series experiment revealed a slight decrease in the incidence of S. glossinidius infection with increasing fly age, which may infer a fitness cost associated with Sodalis infection. The present findings contribute to research on the feasibility of S. glossinidius-based paratransgenic approaches in tsetse and trypanosomiasis control, in particular relating to G. pallidipes control.}, }
@article {pmid25527092, year = {2014}, author = {Price, DR and Wilson, AC}, title = {A substrate ambiguous enzyme facilitates genome reduction in an intracellular symbiont.}, journal = {BMC biology}, volume = {12}, number = {}, pages = {110}, pmid = {25527092}, issn = {1741-7007}, mesh = {Alcohol Oxidoreductases/biosynthesis/genetics ; Animals ; Aphids/*microbiology ; Buchnera/*genetics ; Escherichia coli/genetics ; Evolution, Molecular ; Female ; *Genes, Bacterial ; Metabolic Networks and Pathways ; Pantothenic Acid/biosynthesis ; Symbiosis ; beta-Alanine/biosynthesis ; }, abstract = {BACKGROUND: Genome evolution in intracellular microbial symbionts is characterized by gene loss, generating some of the smallest and most gene-poor genomes known. As a result of gene loss these genomes commonly contain metabolic pathways that are fragmented relative to their free-living relatives. The evolutionary retention of fragmented metabolic pathways in the gene-poor genomes of endosymbionts suggests that they are functional. However, it is not always clear how they maintain functionality. To date, the fragmented metabolic pathways of endosymbionts have been shown to maintain functionality through complementation by host genes, complementation by genes of another endosymbiont and complementation by genes in host genomes that have been horizontally acquired from a microbial source that is not the endosymbiont. Here, we demonstrate a fourth mechanism.<br><br>RESULTS: We investigate the evolutionary retention of a fragmented pathway for the essential nutrient pantothenate (vitamin B5) in the pea aphid, Acyrthosiphon pisum endosymbiosis with Buchnera aphidicola. Using quantitative analysis of gene expression we present evidence for complementation of the Buchnera pantothenate biosynthesis pathway by host genes. Further, using complementation assays in an Escherichia coli mutant we demonstrate functional replacement of a pantothenate biosynthesis enzyme, 2-dehydropantoate 2-reductase (E.C. 1.1.1.169), by an endosymbiont gene, ilvC, encoding a substrate ambiguous enzyme.<br><br>CONCLUSIONS: Earlier studies have speculated that missing enzyme steps in fragmented endosymbiont metabolic pathways are completed by adaptable endosymbiont enzymes from other pathways. Here, we experimentally demonstrate completion of a fragmented endosymbiont vitamin biosynthesis pathway by recruitment of a substrate ambiguous enzyme from another pathway. In addition, this work extends host/symbiont metabolic collaboration in the aphid/Buchnera symbiosis from amino acid metabolism to include vitamin biosynthesis.}, }
@article {pmid25520356, year = {2015}, author = {Ponton, F and Wilson, K and Holmes, A and Raubenheimer, D and Robinson, KL and Simpson, SJ}, title = {Macronutrients mediate the functional relationship between Drosophila and Wolbachia.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1800}, pages = {20142029}, pmid = {25520356}, issn = {1471-2954}, support = {BB/F004311/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Drosophila melanogaster/microbiology/*physiology ; Female ; Fertility/physiology ; Longevity/physiology ; Male ; Nutritional Physiological Phenomena ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia are maternally inherited bacterial endosymbionts that naturally infect a diverse array of arthropods. They are primarily known for their manipulation of host reproductive biology, and recently, infections with Wolbachia have been proposed as a new strategy for controlling insect vectors and subsequent human-transmissible diseases. Yet, Wolbachia abundance has been shown to vary greatly between individuals and the magnitude of the effects of infection on host life-history traits and protection against infection is correlated to within-host Wolbachia abundance. It is therefore essential to better understand the factors that modulate Wolbachia abundance and effects on host fitness. Nutrition is known to be one of the most important mediators of host-symbiont interactions. Here, we used nutritional geometry to quantify the role of macronutrients on insect-Wolbachia relationships in Drosophila melanogaster. Our results show fundamental interactions between diet composition, host diet selection, Wolbachia abundance and effects on host lifespan and fecundity. The results and methods described here open a new avenue in the study of insect-Wolbachia relationships and are of general interest to numerous research disciplines, ranging from nutrition and life-history theory to public health.}, }
@article {pmid25517525, year = {2014}, author = {Soares, HS and Camargo, LM and Gennari, SM and Labruna, MB}, title = {Survey of canine tick-borne diseases in Lábrea, Brazilian Amazon: 'accidental' findings of Dirofilaria immitis infection.}, journal = {Revista brasileira de parasitologia veterinaria = Brazilian journal of veterinary parasitology : Orgao Oficial do Colegio Brasileiro de Parasitologia Veterinaria}, volume = {23}, number = {4}, pages = {473-480}, doi = {10.1590/S1984-29612014093}, pmid = {25517525}, issn = {1984-2961}, mesh = {Animals ; Brazil/epidemiology ; Dirofilariasis/*epidemiology ; Dog Diseases/*epidemiology/*parasitology ; Dogs ; Female ; Incidental Findings ; Male ; Tick-Borne Diseases/epidemiology/*veterinary ; }, abstract = {Blood samples were collected from 99 domestic dogs from the urban and rural areas of the Lábrea municipality, state of Amazonas, Brazil. Canine serum samples were tested by immunofluorescence assay against Rickettsia spp., which revealed that only 3.0% (1/33) and 7.6% (5/66) of the dogs from urban and rural areas, respectively, reacted positively to at least one Rickettsia species. DNA was extracted from canine blood and tested by a battery of PCR assays targeting protozoa of the genera Babesia and Hepatozoon, and bacteria of the genera Rickettsia and Ehrlichia and family Anaplasmataceae. All samples were negative in the PCR assays targeting the genera Babesia, Hepatozoon, Ehrlichia and Rickettsia. For Anaplasmataceae, 3% (1/33) and 39.4% (26/66) of the urban and rural dogs, respectively, yielded amplicons that generated DNA sequences 100% identical to the corresponding sequence of Wolbachia endosymbiont of Dirofilaria immitis. Because of these results, all canine DNA samples were further tested in a PCR assay targeting filarial nematodes, which was positive for 18.2% (6/33) and 57.6% (38/66) urban and rural dogs, respectively. Filarial-PCR products generated DNA sequences 100% identical to D. immitis. While tick-borne infections were rare in Lábrea, D. immitis infection rates were among the highest reported in South America.}, }
@article {pmid25516838, year = {2014}, author = {Johnston, KL and Ford, L and Umareddy, I and Townson, S and Specht, S and Pfarr, K and Hoerauf, A and Altmeyer, R and Taylor, MJ}, title = {Repurposing of approved drugs from the human pharmacopoeia to target Wolbachia endosymbionts of onchocerciasis and lymphatic filariasis.}, journal = {International journal for parasitology. Drugs and drug resistance}, volume = {4}, number = {3}, pages = {278-286}, pmid = {25516838}, issn = {2211-3207}, abstract = {Lymphatic filariasis and onchocerciasis are debilitating diseases caused by parasitic filarial nematodes infecting around 150 million people throughout the tropics with more than 1.5 billion at risk. As with other neglected tropical diseases, classical drug-discovery and development is lacking and a 50 year programme of macrofilaricidal discovery failed to deliver a drug which can be used as a public health tool. Recently, antibiotic targeting of filarial Wolbachia, an essential bacterial symbiont, has provided a novel drug treatment for filariasis with macrofilaricidal activity, although the current gold-standard, doxycycline, is unsuitable for use in mass drug administration (MDA). The anti-Wolbachia (A·WOL) Consortium aims to identify novel anti-Wolbachia drugs, compounds or combinations that are suitable for use in MDA. Development of a Wolbachia cell-based assay has enabled the screening of the approved human drug-pharmacopoeia (∼2600 drugs) for a potential repurposing. This screening strategy has revealed that approved drugs from various classes show significant bacterial load reduction equal to or superior to the gold-standard doxycycline, with 69 orally available hits from different drug categories being identified. Based on our defined hit criteria, 15 compounds were then selectively screened in a Litomosoides sigmodontis mouse model, 4 of which were active. These came from the tetracycline, fluoroquinolone and rifamycin classes. This strategy of repurposing approved drugs is a promising development in the goal of finding a novel treatment against filariasis and could also be a strategy applicable for other neglected tropical diseases.}, }
@article {pmid25512495, year = {2014}, author = {Mayoral, JG and Hussain, M and Joubert, DA and Iturbe-Ormaetxe, I and O'Neill, SL and Asgari, S}, title = {Wolbachia small noncoding RNAs and their role in cross-kingdom communications.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {52}, pages = {18721-18726}, pmid = {25512495}, issn = {1091-6490}, mesh = {Aedes/*microbiology ; Animals ; Drosophila melanogaster ; RNA, Bacterial/genetics/*metabolism ; RNA, Small Untranslated/genetics/*metabolism ; Wolbachia/genetics/*metabolism ; }, abstract = {In prokaryotes, small noncoding RNAs (snRNAs) of 50-500 nt are produced that are important in bacterial virulence and response to environmental stimuli. Here, we identified and characterized snRNAs from the endosymbiotic bacteria, Wolbachia, which are widespread in invertebrates and cause reproductive manipulations. Most importantly, some strains of Wolbachia inhibit replication of several vector-borne pathogens in insects. We demonstrate that two abundant snRNAs, WsnRNA-46 and WsnRNA-49, are expressed in Wolbachia from noncoding RNA transcripts that contain precursors with stem-loop structures. WsnRNAs were detected in Aedes aegypti mosquitoes infected with the wMelPop-CLA strain of Wolbachia and in Drosophila melanogaster and Drosophila simulans infected with wMelPop and wAu strains, respectively, indicating that the WsnRNAs are conserved across species and strains. In addition, we show that the WsnRNAs may potentially regulate host genes and Wolbachia genes. Our findings provide evidence for the production of functional snRNAs by Wolbachia that play roles in cross-kingdom communication between the endosymbiont and the host.}, }
@article {pmid25502669, year = {2014}, author = {Fujimura, R and Nishimura, A and Ohshima, S and Sato, Y and Nishizawa, T and Oshima, K and Hattori, M and Narisawa, K and Ohta, H}, title = {Draft Genome Sequence of the Betaproteobacterial Endosymbiont Associated with the Fungus Mortierella elongata FMR23-6.}, journal = {Genome announcements}, volume = {2}, number = {6}, pages = {}, pmid = {25502669}, issn = {2169-8287}, abstract = {The fungus Mortierella elongata FMR23-6 harbors an endobacterium inside its mycelium. Attempts to isolate the endobacterium from the fungus were not yet successful, but a highly purified bacterial fraction was prepared. Here, we report the draft genome sequence of the endobacterium.}, }
@article {pmid25502564, year = {2014}, author = {Segoli, M and Hoffmann, AA and Lloyd, J and Omodei, GJ and Ritchie, SA}, title = {The effect of virus-blocking Wolbachia on male competitiveness of the dengue vector mosquito, Aedes aegypti.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {12}, pages = {e3294}, pmid = {25502564}, issn = {1935-2735}, mesh = {Aedes/*microbiology/physiology/virology ; Animals ; Competitive Behavior/*physiology ; Dengue/microbiology/prevention &amp; control/transmission ; Dengue Virus/*physiology ; Female ; Male ; Sexual Behavior, Animal/physiology ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: The bacterial endosymbiont Wolbachia blocks the transmission of dengue virus by its vector mosquito Aedes aegypti, and is currently being evaluated for control of dengue outbreaks. Wolbachia induces cytoplasmic incompatibility (CI) that results in the developmental failure of offspring in the cross between Wolbachia-infected males and uninfected females. This increases the relative success of infected females in the population, thereby enhancing the spread of the beneficial bacterium. However, Wolbachia spread via CI will only be feasible if infected males are sufficiently competitive in obtaining a mate under field conditions. We tested the effect of Wolbachia on the competitiveness of A. aegypti males under semi-field conditions.<br><br>In a series of experiments we exposed uninfected females to Wolbachia-infected and uninfected males simultaneously. We scored the competitiveness of infected males according to the proportion of females producing non-viable eggs due to incompatibility. We found that infected males were equally successful to uninfected males in securing a mate within experimental tents and semi-field cages. This was true for males infected by the benign wMel Wolbachia strain, but also for males infected by the virulent wMelPop (popcorn) strain. By manipulating male size we found that larger males had a higher success than smaller underfed males in the semi-field cages, regardless of their infection status.<br><br>CONCLUSIONS/SIGNIFICANCE: The results indicate that Wolbachia infection does not reduce the competitiveness of A. aegypti males. Moreover, the body size effect suggests a potential advantage for lab-reared Wolbachia-males during a field release episode, due to their better nutrition and larger size. This may promote Wolbachia spread via CI in wild mosquito populations and underscores its potential use for disease control.}, }
@article {pmid25499750, year = {2015}, author = {Cao, W and Ma, Z and Chen, YH and Yu, X}, title = {Pichia anomala, a new species of yeast-like endosymbionts and its variation in small brown planthopper (Laodelphax striatellus).}, journal = {Journal of bioscience and bioengineering}, volume = {119}, number = {6}, pages = {669-673}, doi = {10.1016/j.jbiosc.2014.11.007}, pmid = {25499750}, issn = {1347-4421}, mesh = {Animals ; DNA, Ribosomal/genetics ; Denaturing Gradient Gel Electrophoresis ; Female ; Genetic Variation/genetics ; Hemiptera/anatomy &amp; histology/growth &amp; development/*microbiology ; In Situ Hybridization, Fluorescence ; Nymph/microbiology ; Oryza/parasitology ; Phylogeny ; Pichia/classification/*genetics/*isolation &amp; purification/physiology ; RNA, Ribosomal, 18S/genetics ; Real-Time Polymerase Chain Reaction ; *Symbiosis ; Virulence ; }, abstract = {Yeast-like symbionts (YLS) are endosymbionts that promote the growth of delphacid planthoppers (Hemiptera: Delphacidae), some of which are pests on cultivated rice. Identification and characterization of YLS growth can be helpful for pest control, because it has been demonstrated that there is a variety of YLS in rice planthopper and they affected the planthopper's growth and virulence to plant hosts. So, elucidation of the species of YLS in planthopper is crucial for exploiting a new way to control planthopper. In this study, a new isolated of YLS was obtained from the small brown planthopper, Laodelphax striatellus, which was cultured in vitro, simultaneously identified as Pichia anomala based on its phylogenetic analysis. In order to confirm the existence of P. anomala in the L. striatellus body, we used the denaturing gradient gel electrophoresis (DGGE) to identify the YLS and obtain the specific bands for P. anomala. The quantification and localization of P. anomala in L. striatellus samples were determined by fluorescent in situ hybridization (FISH) using genus-specific 18S rDNA targeted probe. The result confirmed that a certain number of P. anomala exist in L. striatellus's abdomen. Subsequently, the variation and copy number of P. anomala in different L. striatellus instars was measured by using absolute quantitative real-time PCR (qPCR), the results indicated that the new isolated strain was closely related to the developmental process of L. striatellus.}, }
@article {pmid25496002, year = {2014}, author = {Klasson, L and Kumar, N and Bromley, R and Sieber, K and Flowers, M and Ott, SH and Tallon, LJ and Andersson, SG and Dunning Hotopp, JC}, title = {Extensive duplication of the Wolbachia DNA in chromosome four of Drosophila ananassae.}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {1097}, pmid = {25496002}, issn = {1471-2164}, support = {DP2 OD007372/OD/NIH HHS/United States ; T32 DK067872/DK/NIDDK NIH HHS/United States ; 1-DP2-OD007372/OD/NIH HHS/United States ; }, mesh = {Animals ; Chromosome Mapping ; *DNA Replication ; DNA, Bacterial/*biosynthesis/*genetics ; Drosophila/*genetics/*microbiology ; Female ; Gene Dosage ; *Gene Transfer, Horizontal ; Genome, Insect/genetics ; Heterozygote ; Male ; Polytene Chromosomes/genetics ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {BACKGROUND: Lateral gene transfer (LGT) from bacterial Wolbachia endosymbionts has been detected in ~20% of arthropod and nematode genome sequencing projects. Many of these transfers are large and contain a substantial part of the Wolbachia genome.<br><br>RESULTS: Here, we re-sequenced three D. ananassae genomes from Asia and the Pacific that contain large LGTs from Wolbachia. We find that multiple copies of the Wolbachia genome are transferred to the Drosophila nuclear genome in all three lines. In the D. ananassae line from Indonesia, the copies of Wolbachia DNA in the nuclear genome are nearly identical in size and sequence yielding an even coverage of mapped reads over the Wolbachia genome. In contrast, the D. ananassae lines from Hawaii and India show an uneven coverage of mapped reads over the Wolbachia genome suggesting that different parts of these LGTs are present in different copy numbers. In the Hawaii line, we find that this LGT is underrepresented in third instar larvae indicative of being heterochromatic. Fluorescence in situ hybridization of mitotic chromosomes confirms that the LGT in the Hawaii line is heterochromatic and represents ~20% of the sequence on chromosome 4 (dot chromosome, Muller element F).<br><br>CONCLUSIONS: This collection of related lines contain large lateral gene transfers composed of multiple Wolbachia genomes that constitute >2% of the D. ananassae genome (~5 Mbp) and partially explain the abnormally large size of chromosome 4 in D. ananassae.}, }
@article {pmid25495525, year = {2014}, author = {Furnholm, TR and Tisa, LS}, title = {The ins and outs of metal homeostasis by the root nodule actinobacterium Frankia.}, journal = {BMC genomics}, volume = {15}, number = {}, pages = {1092}, pmid = {25495525}, issn = {1471-2164}, mesh = {Adenosine Triphosphatases/chemistry/metabolism ; Amino Acid Sequence ; Bacterial Proteins/chemistry/metabolism ; Frankia/*metabolism ; *Homeostasis ; Metals/*metabolism ; Molecular Sequence Data ; Plant Roots/*microbiology ; Sequence Homology, Amino Acid ; }, abstract = {BACKGROUND: Frankia are actinobacteria that form a symbiotic nitrogen-fixing association with actinorhizal plants, and play a significant role in actinorhizal plant colonization of metal contaminated areas. Many Frankia strains are known to be resistant to several toxic metals and metalloids including Pb(2+), Al(+3), SeO2, Cu(2+), AsO4, and Zn(2+). With the availability of eight Frankia genome databases, comparative genomics approaches employing phylogeny, amino acid composition analysis, and synteny were used to identify metal homeostasis mechanisms in eight Frankia strains. Characterized genes from the literature and a meta-analysis of 18 heavy metal gene microarray studies were used for comparison.<br><br>RESULTS: Unlike most bacteria, Frankia utilize all of the essential trace elements (Ni, Co, Cu, Se, Mo, B, Zn, Fe, and Mn) and have a comparatively high percentage of metalloproteins, particularly in the more metal resistant strains. Cation diffusion facilitators, being one of the few known metal resistance mechanisms found in the Frankia genomes, were strong candidates for general divalent metal resistance in all of the Frankia strains. Gene duplication and amino acid substitutions that enhanced the metal affinity of CopA and CopCD proteins may be responsible for the copper resistance found in some Frankia strains. CopA and a new potential metal transporter, DUF347, may be involved in the particularly high lead tolerance in Frankia. Selenite resistance involved an alternate sulfur importer (CysPUWA) that prevents sulfur starvation, and reductases to produce elemental selenium. The pattern of arsenate, but not arsenite, resistance was achieved by Frankia using the novel arsenite exporter (AqpS) previously identified in the nitrogen-fixing plant symbiont Sinorhizobium meliloti. Based on the presence of multiple tellurite resistance factors, a new metal resistance (tellurite) was identified and confirmed in Frankia.<br><br>CONCLUSIONS: Each strain had a unique combination of metal import, binding, modification, and export genes that explain differences in patterns of metal resistance between strains. Frankia has achieved similar levels of metal and metalloid resistance as bacteria from highly metal-contaminated sites. From a bioremediation standpoint, it is important to understand mechanisms that allow the endosymbiont to survive and infect actinorhizal plants in metal contaminated soils.}, }
@article {pmid25473015, year = {2015}, author = {Cayetano, L and Rothacher, L and Simon, JC and Vorburger, C}, title = {Cheaper is not always worse: strongly protective isolates of a defensive symbiont are less costly to the aphid host.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1799}, pages = {20142333}, pmid = {25473015}, issn = {1471-2954}, mesh = {Animals ; Aphids/*microbiology ; Biological Evolution ; Host-Parasite Interactions/genetics ; Life Cycle Stages ; Reproduction ; *Symbiosis ; }, abstract = {Defences against parasites are typically associated with costs to the host that contribute to the maintenance of variation in resistance. This also applies to the defence provided by the facultative bacterial endosymbiont Hamiltonella defensa, which protects its aphid hosts against parasitoid wasps while imposing life-history costs. To investigate the cost-benefit relationship within protected hosts, we introduced multiple isolates of H. defensa to the same genetic backgrounds of black bean aphids, Aphis fabae, and we quantified the protection against their parasitoid Lysiphlebus fabarum as well as the costs to the host (reduced lifespan and reproduction) in the absence of parasitoids. Surprisingly, we observed the opposite of a trade-off. Strongly protective isolates of H. defensa reduced lifespan and lifetime reproduction of unparasitized aphids to a lesser extent than weakly protective isolates. This finding has important implications for the evolution of defensive symbiosis and highlights the need for a better understanding of how strain variation in protective symbionts is maintained.}, }
@article {pmid25473004, year = {2015}, author = {Wall, M and Putchim, L and Schmidt, GM and Jantzen, C and Khokiattiwong, S and Richter, C}, title = {Large-amplitude internal waves benefit corals during thermal stress.}, journal = {Proceedings. Biological sciences}, volume = {282}, number = {1799}, pages = {20140650}, pmid = {25473004}, issn = {1471-2954}, mesh = {Animals ; Anthozoa/*physiology ; Conservation of Natural Resources ; Coral Reefs ; Environment ; Linear Models ; Seawater ; *Stress, Physiological ; *Temperature ; Tropical Climate ; *Water Movements ; }, abstract = {Tropical scleractinian corals are particularly vulnerable to global warming as elevated sea surface temperatures (SSTs) disrupt the delicate balance between the coral host and their algal endosymbionts, leading to symbiont expulsion, mass bleaching and mortality. While satellite sensing of SST has proved a reliable predictor of coral bleaching at the regional scale, there are large deviations in bleaching severity and mortality on the local scale that are poorly understood. Here, we show that internal waves play a major role in explaining local coral bleaching and mortality patterns in the Andaman Sea. Despite a severe region-wide SST anomaly in May 2010, frequent upslope intrusions of cold sub-pycnocline waters due to breaking large-amplitude internal waves (LAIW) mitigated coral bleaching and mortality in shallow waters. In LAIW-sheltered waters, by contrast, bleaching-susceptible species suffered severe bleaching and total mortality. These findings suggest that LAIW benefit coral reefs during thermal stress and provide local refugia for bleaching-susceptible corals. LAIW are ubiquitous in tropical stratified waters and their swash zones may thus be important conservation areas for the maintenance of coral diversity in a warming climate. Taking LAIW into account can significantly improve coral bleaching predictions and provide a valuable tool for coral reef conservation and management.}, }
@article {pmid25470996, year = {2014}, author = {Raphael, KA and Shearman, DC and Gilchrist, AS and Sved, JA and Morrow, JL and Sherwin, WB and Riegler, M and Frommer, M}, title = {Australian endemic pest tephritids: genetic, molecular and microbial tools for improved Sterile Insect Technique.}, journal = {BMC genetics}, volume = {15 Suppl 2}, number = {Suppl 2}, pages = {S9}, pmid = {25470996}, issn = {1471-2156}, mesh = {Animals ; *Animals, Genetically Modified ; Australia ; *Biotechnology ; Diptera/*genetics ; Female ; Gene Expression Profiling ; Genetic Markers ; Genome, Insect ; Infertility/*genetics ; Male ; Sex Factors ; }, abstract = {Among Australian endemic tephritid fruit flies, the sibling species Bactrocera tryoni and Bactrocera neohumeralis have been serious horticultural pests since the introduction of horticulture in the nineteenth century. More recently, Bactrocera jarvisi has also been declared a pest in northern Australia. After several decades of genetic research there is now a range of classical and molecular genetic tools that can be used to develop improved Sterile Insect Technique (SIT) strains for control of these pests. Four-way crossing strategies have the potential to overcome the problem of inbreeding in mass-reared strains of B. tryoni. The ability to produce hybrids between B. tryoni and the other two species in the laboratory has proved useful for the development of genetically marked strains. The identification of Y-chromosome markers in B. jarvisi means that male and female embryos can be distinguished in any strain that carries a B. jarvisi Y chromosome. This has enabled the study of homologues of the sex-determination genes during development of B jarvisi and B. tryoni, which is necessary for the generation of genetic-sexing strains. Germ-line transformation has been established and a draft genome sequence for B. tryoni released. Transcriptomes from various species, tissues and developmental stages, to aid in identification of manipulation targets for improving SIT, have been assembled and are in the pipeline. Broad analyses of the microbiome have revealed a metagenome that is highly variable within and across species and defined by the environment. More specific analyses detected Wolbachia at low prevalence in the tropics but absent in temperate regions, suggesting a possible role for this endosymbiont in future control strategies.}, }
@article {pmid25467196, year = {2014}, author = {Rosic, N and Kaniewska, P and Chan, CK and Ling, EY and Edwards, D and Dove, S and Hoegh-Guldberg, O}, title = {Early transcriptional changes in the reef-building coral Acropora aspera in response to thermal and nutrient stress.}, journal = {BMC genomics}, volume = {15}, number = {}, pages = {1052}, pmid = {25467196}, issn = {1471-2164}, mesh = {Animals ; Anthozoa/*genetics/metabolism ; Computational Biology ; Coral Reefs ; Energy Metabolism ; Gene Expression Profiling ; *Gene Expression Regulation ; Molecular Sequence Annotation ; Oxidation-Reduction ; Photosynthesis ; Stress, Physiological/*genetics ; Temperature ; *Transcription, Genetic ; }, abstract = {BACKGROUND: Changes to the environment as a result of human activities can result in a range of impacts on reef building corals that include coral bleaching (reduced concentrations of algal symbionts), decreased coral growth and calcification, and increased incidence of diseases and mortality. Understanding how elevated temperatures and nutrient concentration affect early transcriptional changes in corals and their algal endosymbionts is critically important for evaluating the responses of coral reefs to global changes happening in the environment. Here, we investigated the expression of genes in colonies of the reef-building coral Acropora aspera exposed to short-term sub-lethal levels of thermal (+6°C) and nutrient stress (ammonium-enrichment: 20 μM).<br><br>RESULTS: The RNA-Seq data provided hundreds of differentially expressed genes (DEGs) corresponding to various stress regimes, with 115 up- and 78 down-regulated genes common to all stress regimes. A list of DEGs included up-regulated coral genes like cytochrome c oxidase and NADH-ubiquinone oxidoreductase and up-regulated photosynthetic genes of algal origin, whereas coral GFP-like fluorescent chromoprotein and sodium/potassium-transporting ATPase showed reduced transcript levels. Taxonomic analyses of the coral holobiont disclosed the dominant presence of transcripts from coral (~70%) and Symbiodinium (~10-12%), as well as ~15-20% of unknown sequences which lacked sequence identity to known genes. Gene ontology analyses revealed enriched pathways, which led to changes in the dynamics of protein networks affecting growth, cellular processes, and energy requirement.<br><br>CONCLUSIONS: In corals with preserved symbiont physiological performance (based on Fv/Fm, photo-pigment and symbiont density), transcriptomic changes and DEGs provided important insight into early stages of the stress response in the coral holobiont. Although there were no signs of coral bleaching after exposure to short-term thermal and nutrient stress conditions, we managed to detect oxidative stress and apoptotic changes on a molecular level and provide a list of prospective stress biomarkers for both partners in symbiosis. Consequently, our findings are important for understanding and anticipating impacts of anthropogenic global climate change on coral reefs.}, }
@article {pmid25465085, year = {2014}, author = {Li, G and Lai, R and Duan, G and Lyu, LB and Zhang, ZY and Liu, H and Xiang, X}, title = {Isolation and identification of symbiotic bacteria from the skin, mouth, and rectum of wild and captive tree shrews.}, journal = {Dong wu xue yan jiu = Zoological research}, volume = {35}, number = {6}, pages = {492-499}, pmid = {25465085}, issn = {0254-5853}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; DNA, Bacterial/genetics ; Female ; Male ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*physiology ; Tupaiidae/*microbiology ; }, abstract = {Endosymbionts influence many aspects of their hosts' health conditions, including physiology, development, immunity, metabolism, etc. Tree shrews (Tupaia belangeri chinensis) have attracted increasing attention in modeling human diseases and therapeutic responses due to their close relationship with primates. To clarify the situation of symbiotic bacteria from their body surface, oral cavity, and anus, 12 wild and 12 the third generation of captive tree shrews were examined. Based on morphological and cultural characteristics, physiological and biochemical tests, as well as the 16S rDNA full sequence analysis, 12 bacteria strains were isolated and identified from the wild tree shrews: body surface: Bacillus subtilis (detection rate 42%), Pseudomonas aeruginosa (25%), Staphlococcus aureus (33%), S. Epidermidis (75%), Micrococcus luteus (25%), Kurthia gibsonii (17%); oral cavity: Neisseria mucosa (58%), Streptococcus pneumonia (17%); anus: Enterococcus faecalis (17%), Lactococus lactis (33%), Escherichia coli (92%), Salmonella typhosa (17%); whereas, four were indentified from the third generation captive tree shrews: body surface: S. epidermidis (75%); oral cavity: N.mucosa (67%); anus: L. lactis (33%), E. coli (100%). These results indicate that S. epidermidis, N. mucosa, L. lactis and E. coli were major bacteria in tree shrews, whereas, S. aureus, M. luteus, K. gibsonii, E. faecalis and S. typhosa were species-specific flora. This study facilitates the future use of tree shrews as a standard experimental animal and improves our understanding of the relationship between endosymbionts and their hosts.}, }
@article {pmid25462464, year = {2015}, author = {Barros, I and Divya, B and Martins, I and Vandeperre, F and Santos, RS and Bettencourt, R}, title = {Post-capture immune gene expression studies in the deep-sea hydrothermal vent mussel Bathymodiolus azoricus acclimatized to atmospheric pressure.}, journal = {Fish &amp; shellfish immunology}, volume = {42}, number = {1}, pages = {159-170}, doi = {10.1016/j.fsi.2014.10.018}, pmid = {25462464}, issn = {1095-9947}, mesh = {Acclimatization/*immunology ; Animals ; Atlantic Ocean ; Atmospheric Pressure ; Bivalvia/genetics/*immunology ; Cluster Analysis ; DNA Primers/genetics ; Gene Expression Regulation/*immunology ; Gills/immunology/microbiology ; *Hydrothermal Vents ; Kinetics ; Real-Time Polymerase Chain Reaction ; Time Factors ; }, abstract = {Deep-sea hydrothermal vents are extreme habitats that are distributed worldwide in association with volcanic and tectonic events, resulting thus in the establishment of particular environmental conditions, in which high pressure, steep temperature gradients, and potentially toxic concentrations of sulfur, methane and heavy metals constitute driving factors for the foundation of chemosynthetic-based ecosystems. Of all the different macroorganisms found at deep-sea hydrothermal vents, the mussel Bathymodiolus azoricus is the most abundant species inhabiting the vent ecosystems from the Mid-Atlantic Ridge (MAR). In the present study, the effect of long term acclimatization at atmospheric pressure on host-symbiotic associations were studied in light of the ensuing physiological adaptations from which the immune and endosymbiont gene expressions were concomitantly quantified by means of real-time PCR. The expression of immune genes at 0 h, 12 h, 24 h, 36 h, 48 h, 72 h, 1 week and 3 weeks post-capture acclimatization was investigated and their profiles compared across the samples tested. The gene signal distribution for host immune and bacterial genes followed phasic changes in gene expression at 24 h, 1 week and 3 weeks acclimatization when compared to other time points tested during this temporal expression study. Analyses of the bacterial gene expression also suggested that both bacterial density and activity could contribute to shaping the intricate association between endosymbionts and host immune genes whose expression patterns seem to be concomitant at 1 week acclimatization. Fluorescence in situ hybridization was used to assess the distribution and prevalence of endosymbiont bacteria within gill tissues confirming the gradual loss of sulfur-oxidizing (SOX) and methane-oxidizing (MOX) bacteria during acclimatization. The present study addresses the deep-sea vent mussel B. azoricus as a model organism to study how acclimatization in aquaria and the prevalence of symbiotic bacteria are driving the expression of host immune genes. Tight associations, unseen thus far, suggest that host immune and bacterial gene expression patterns reflect distinct physiological responses over the course of acclimatization under aquarium conditions.}, }
@article {pmid25460233, year = {2014}, author = {Votýpka, J and Kostygov, AY and Kraeva, N and Grybchuk-Ieremenko, A and Tesařová, M and Grybchuk, D and Lukeš, J and Yurchenko, V}, title = {Kentomonas gen. n., a new genus of endosymbiont-containing trypanosomatids of Strigomonadinae subfam. n.}, journal = {Protist}, volume = {165}, number = {6}, pages = {825-838}, doi = {10.1016/j.protis.2014.09.002}, pmid = {25460233}, issn = {1618-0941}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Animals ; Bayes Theorem ; Cloning, Molecular ; DNA, Bacterial/isolation &amp; purification ; DNA, Viral/isolation &amp; purification ; Likelihood Functions ; Models, Genetic ; *Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal, 18S/genetics ; Sarcophagidae/parasitology ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis/*genetics ; Trypanosomatina/*classification/isolation &amp; purification/microbiology/virology ; }, abstract = {Compared to their relatives, the diversity of endosymbiont-containing Trypanosomatidae remains under-investigated, with only two new species described in the past 25 years, bringing the total to six. The possible reasons for such a poor representation of this group are either their overall scarcity or susceptibility of their symbionts to antibiotics that are traditionally used for cultivation of flagellates. In this work we describe the isolation, cultivation, as well as morphological and molecular characterization of a novel endosymbiont-harboring trypanosomatid species, Kentomonas sorsogonicus sp. n. The newly erected genus Kentomonas gen. n. shares many common features with the genera Angomonas and Strigomonas, such as the presence of an extensive system of peripheral mitochondrial branches distorting the corset of subpellicular microtubules, large and loosely packed kinetoplast, and a rudimentary paraflagellar rod. Here we also propose to unite all endosymbiont-bearing trypanosomatids into the new subfamily Strigomonadinae subfam. n.}, }
@article {pmid25458121, year = {2014}, author = {McCall, JW and Kramer, L and Genchi, C and Guerrero, J and Dzimianski, MT and Mansour, A and McCall, SD and Carson, B}, title = {Effects of doxycycline on heartworm embryogenesis, transmission, circulating microfilaria, and adult worms in microfilaremic dogs.}, journal = {Veterinary parasitology}, volume = {206}, number = {1-2}, pages = {5-13}, doi = {10.1016/j.vetpar.2014.09.023}, pmid = {25458121}, issn = {1873-2550}, mesh = {Animals ; Antigens, Helminth/blood ; Culicidae/parasitology ; Dirofilaria immitis/*drug effects/embryology ; Dirofilariasis/*drug therapy/transmission ; Dog Diseases/*drug therapy/transmission ; Dogs ; Doxycycline/*pharmacology/*therapeutic use ; Embryonic Development/drug effects ; Microfilariae/drug effects ; }, abstract = {Tetracycline treatment of animals or humans infected with filariae that harbor Wolbachia endosymbionts blocks further embryogenesis, and existing microfilariae gradually die. This treatment also kills developing larvae and has a slow-kill effect on adult filariae, all presumably due to elimination of the Wolbachia. Also, Dirofilaria immitis microfilariae in blood collected from dogs up to 25 days after the last dose of doxycycline developed to infective L3 that were normal in appearance and motility in mosquitoes but did not continue to develop or migrate normally after subcutaneous (SC) injection into dogs. The present study was designed to determine whether heartworm microfilariae collected at later times after treatment would regain the ability to continue normal development in a dog. The study also was expected to yield valuable data on the effects of treatment on microfilariae and antigen levels and adult worms. The study was conducted in 16 dogs as two separate replicates at different times. A total of five dogs (two in Replicate A and three in Replicate B) infected either by SC injection of L3 or intravenous transplantation of adult heartworms were given doxycycline orally at 10mg/kg twice daily for 30 days, with three untreated controls. Microfilarial counts in the five treated dogs gradually declined during the 12-13 months after treatment initiation. Two dogs were amicrofilaremic before necropsy and three had 13 or fewer microfilariae/ml. Only one treated dog was negative for heartworm antigen before necropsy. Overall, treated dogs generally had fewer live adult heartworms than controls, and most of their live worms were moribund. All three control dogs remained positive for microfilariae and antigen and had many live worms. L3 from mosquitoes fed on blood collected 73-77 or 161-164 days after initiation of doxycycline treatments were injected SC into five dogs. None of the dogs injected with L3 from mosquitoes fed on blood from doxycycline-treated dogs were ever positive for microfilariae or antigen, and none had worms at necropsy; three control dogs were positive for microfilariae and antigen and had many live worms. These data indicate that doxycycline treatment of microfilaremic dogs gradually reduces numbers of microfilariae and blocks further transmission of heartworms. This latter effect should be highly effective in reducing the rate of selection of heartworms with genes that confer resistance to macrocyclic lactone preventives and microfilaricides. The data also suggest that doxycycline has a slow-kill effect on adult heartworms.}, }
@article {pmid25453104, year = {2014}, author = {Barbier, T and Collard, F and Zúñiga-Ripa, A and Moriyón, I and Godard, T and Becker, J and Wittmann, C and Van Schaftingen, E and Letesson, JJ}, title = {Erythritol feeds the pentose phosphate pathway via three new isomerases leading to D-erythrose-4-phosphate in Brucella.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {50}, pages = {17815-17820}, pmid = {25453104}, issn = {1091-6490}, mesh = {Biosynthetic Pathways/*physiology ; Brucella/*metabolism/pathogenicity ; Carbohydrate Epimerases/*metabolism ; Carbon Isotopes/metabolism ; Erythritol/*metabolism ; Gas Chromatography-Mass Spectrometry ; Isomerism ; Phosphorylation ; Spectrophotometry ; Sugar Phosphates/*biosynthesis ; }, abstract = {Erythritol is an important nutrient for several α-2 Proteobacteria, including N2-fixing plant endosymbionts and Brucella, a worldwide pathogen that finds this four-carbon polyol in genital tissues. Erythritol metabolism involves phosphorylation to L-erythritol-4-phosphate by the kinase EryA and oxidation of the latter to L-3-tetrulose 4-phosphate by the dehydrogenase EryB. It is accepted that further steps involve oxidation by the putative dehydrogenase EryC and subsequent decarboxylation to yield triose-phosphates. Accordingly, growth on erythritol as the sole C source should require aldolase and fructose-1,6-bisphosphatase to produce essential hexose-6-monophosphate. However, we observed that a mutant devoid of fructose-1,6-bisphosphatases grew normally on erythritol and that EryC, which was assumed to be a dehydrogenase, actually belongs to the xylose isomerase superfamily. Moreover, we found that TpiA2 and RpiB, distant homologs of triose phosphate isomerase and ribose 5-phosphate isomerase B, were necessary, as previously shown for Rhizobium. By using purified recombinant enzymes, we demonstrated that L-3-tetrulose-4-phosphate was converted to D-erythrose 4-phosphate through three previously unknown isomerization reactions catalyzed by EryC (tetrulose-4-phosphate racemase), TpiA2 (D-3-tetrulose-4-phosphate isomerase; renamed EryH), and RpiB (D-erythrose-4-phosphate isomerase; renamed EryI), a pathway fully consistent with the isotopomer distribution of the erythrose-4-phosphate-derived amino acids phenylalanine and tyrosine obtained from bacteria grown on (13)C-labeled erythritol. D-erythrose-4-phosphate is then converted by enzymes of the pentose phosphate pathway to glyceraldehyde 3-phosphate and fructose 6-phosphate, thus bypassing fructose-1,6-bisphosphatase. This is the first description to our knowledge of a route feeding carbohydrate metabolism exclusively via D-erythrose 4-phosphate, a pathway that may provide clues to the preferential metabolism of erythritol by Brucella and its role in pathogenicity.}, }
@article {pmid25433394, year = {2014}, author = {Luck, AN and Evans, CC and Riggs, MD and Foster, JM and Moorhead, AR and Slatko, BE and Michalski, ML}, title = {Concurrent transcriptional profiling of Dirofilaria immitis and its Wolbachia endosymbiont throughout the nematode life cycle reveals coordinated gene expression.}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {1041}, pmid = {25433394}, issn = {1471-2164}, mesh = {Animals ; Dirofilaria immitis/*genetics/pathogenicity ; Dirofilariasis/genetics/parasitology ; Dogs ; Female ; Gene Expression Profiling ; Gene Expression Regulation, Developmental ; Life Cycle Stages/genetics ; Male ; Microfilariae/*genetics/parasitology ; Symbiosis/*genetics ; Wolbachia/*genetics/pathogenicity ; }, abstract = {BACKGROUND: Dirofilaria immitis, or canine heartworm, is a filarial nematode parasite that infects dogs and other mammals worldwide. Current disease control relies on regular administration of anthelmintic preventives, however, relatively poor compliance and evidence of developing drug resistance could warrant alternative measures against D. immitis and related human filarial infections be taken. As with many other filarial nematodes, D. immitis contains Wolbachia, an obligate bacterial endosymbiont thought to be involved in providing certain critical metabolites to the nematode. Correlations between nematode and Wolbachia transcriptomes during development have not been examined. Therefore, we detailed the developmental transcriptome of both D. immitis and its Wolbachia (wDi) in order to gain a better understanding of parasite-endosymbiont interactions throughout the nematode life cycle.<br><br>RESULTS: Over 215 million single-end 50 bp reads were generated from total RNA from D. immitis adult males and females, microfilariae (mf) and third and fourth-stage larvae (L3 and L4). We critically evaluated the transcriptomes of the various life cycle stages to reveal sex-biased transcriptional patterns, as well as transcriptional differences between larval stages that may be involved in larval maturation. Hierarchical clustering revealed both D. immitis and wDi transcriptional activity in the L3 stage is clearly distinct from other life cycle stages. Interestingly, a large proportion of both D. immitis and wDi genes display microfilarial-biased transcriptional patterns. Concurrent transcriptome sequencing identified potential molecular interactions between parasite and endosymbiont that are more prominent during certain life cycle stages. In support of metabolite provisioning between filarial nematodes and Wolbachia, the synthesis of the critical metabolite, heme, by wDi appears to be synchronized in a stage-specific manner (mf-specific) with the production of heme-binding proteins in D. immitis.<br><br>CONCLUSIONS: Our integrated transcriptomic study has highlighted interesting correlations between Wolbachia and D. immitis transcription throughout the life cycle and provided a resource that may be used for the development of novel intervention strategies, not only for the treatment and prevention of D. immitis infections, but of other closely related human parasites as well.}, }
@article {pmid25432941, year = {2014}, author = {Degli Esposti, M}, title = {Bioenergetic evolution in proteobacteria and mitochondria.}, journal = {Genome biology and evolution}, volume = {6}, number = {12}, pages = {3238-3251}, pmid = {25432941}, issn = {1759-6653}, mesh = {*Energy Metabolism ; *Evolution, Molecular ; Methanol/metabolism ; Mitochondria/*genetics/metabolism ; Proteobacteria/*genetics/metabolism/ultrastructure ; Symbiosis ; }, abstract = {Mitochondria are the energy-producing organelles of our cells and derive from bacterial ancestors that became endosymbionts of microorganisms from a different lineage, together with which they formed eukaryotic cells. For a long time it has remained unclear from which bacteria mitochondria actually evolved, even if these organisms in all likelihood originated from the α lineage of proteobacteria. A recent article (Degli Esposti M, et al. 2014. Evolution of mitochondria reconstructed from the energy metabolism of living bacteria. PLoS One 9:e96566) has presented novel evidence indicating that methylotrophic bacteria could be among the closest living relatives of mitochondrial ancestors. Methylotrophs are ubiquitous bacteria that live on single carbon sources such as methanol and methane; in the latter case they are called methanotrophs. In this review, I examine their possible ancestry to mitochondria within a survey of the common features that can be found in the central and terminal bioenergetic systems of proteobacteria and mitochondria. I also discuss previously overlooked information on methanotrophic bacteria, in particular their intracytoplasmic membranes resembling mitochondrial cristae and their capacity of establishing endosymbiotic relationships with invertebrate animals and archaic plants. This information appears to sustain the new idea that mitochondrial ancestors could be related to extant methanotrophic proteobacteria, a possibility that the genomes of methanotrophic endosymbionts will hopefully clarify.}, }
@article {pmid25431199, year = {2014}, author = {Farrar, K and Bryant, D and Cope-Selby, N}, title = {Understanding and engineering beneficial plant-microbe interactions: plant growth promotion in energy crops.}, journal = {Plant biotechnology journal}, volume = {12}, number = {9}, pages = {1193-1206}, pmid = {25431199}, issn = {1467-7652}, support = {BB/E024319/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/E024319/2/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {*Biofuels ; Crops, Agricultural/*growth &amp; development ; *Genetic Engineering ; *Plant Development ; Plants/*microbiology ; *Symbiosis ; }, abstract = {Plant production systems globally must be optimized to produce stable high yields from limited land under changing and variable climates. Demands for food, animal feed, and feedstocks for bioenergy and biorefining applications, are increasing with population growth, urbanization and affluence. Low-input, sustainable, alternatives to petrochemical-derived fertilizers and pesticides are required to reduce input costs and maintain or increase yields, with potential biological solutions having an important role to play. In contrast to crops that have been bred for food, many bioenergy crops are largely undomesticated, and so there is an opportunity to harness beneficial plant-microbe relationships which may have been inadvertently lost through intensive crop breeding. Plant-microbe interactions span a wide range of relationships in which one or both of the organisms may have a beneficial, neutral or negative effect on the other partner. A relatively small number of beneficial plant-microbe interactions are well understood and already exploited; however, others remain understudied and represent an untapped reservoir for optimizing plant production. There may be near-term applications for bacterial strains as microbial biopesticides and biofertilizers to increase biomass yield from energy crops grown on land unsuitable for food production. Longer term aims involve the design of synthetic genetic circuits within and between the host and microbes to optimize plant production. A highly exciting prospect is that endosymbionts comprise a unique resource of reduced complexity microbial genomes with adaptive traits of great interest for a wide variety of applications.}, }
@article {pmid25429862, year = {2015}, author = {König, S and Le Guyader, H and Gros, O}, title = {Thioautotrophic bacterial endosymbionts are degraded by enzymatic digestion during starvation: Case study of two lucinids Codakia orbicularis and C. orbiculata.}, journal = {Microscopy research and technique}, volume = {78}, number = {2}, pages = {173-179}, doi = {10.1002/jemt.22458}, pmid = {25429862}, issn = {1097-0029}, mesh = {Animals ; Bivalvia/*microbiology ; Gammaproteobacteria/physiology/ultrastructure ; Microscopy, Electron, Transmission ; Symbiosis/*physiology ; }, abstract = {The Caribbean bivalves Codakia orbicularis (Linné, 1758) and C. orbiculata (Montagu, 1808) live in seagrass beds of Thalassia testudinum and harbor intracellular sulfur-oxidizing gamma-proteobacteria. These bacterial symbionts fix CO2 via the Calvin Benson cycle and provide organic compounds to the bivalve. During experimentally induced starvation, no reduced sulfur compounds and no organic particle food are available; the symbionts could be considered as the sole nutrient source of the host bivalve. A previous study has shown that the intracellular bacterial population decreased considerably during starvation and that bacterial endosymbionts were not released by the bivalves. In this study, the activity of two lysosomal marker enzymes (acid phosphatase and arylsulfatase) was detected using cytochemical experiments coupled with energy-dispersive X-ray transmission electron microscopy during sulfide and organic particle starvation. The degradation of bacterial endosymbionts began after 2 weeks of starvation in C. orbiculata and after 3 weeks in C. orbicularis. Degradation processes seem to be continuous over several months and could be responsible for the disappearance of the bacterial endosymbionts within the gills during starvation. These data suggest that the host use symbionts as a nutrient source to survive a hunger crisis. The carbon transfer from the symbionts to the host could be flexible and could consist in transfer of organic matter, "milking," under normal feeding conditions and digestion of the symbionts under starved conditions.}, }
@article {pmid25424737, year = {2015}, author = {Andersen, JC and Gwiazdowski, RA and Gdanetz, K and Gruwell, ME}, title = {Armored scale insect endosymbiont diversity at the species level: genealogical patterns of Uzinura diasipipdicola in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex (Hemiptera: Coccoidea: Diaspididae).}, journal = {Bulletin of entomological research}, volume = {105}, number = {1}, pages = {110-120}, doi = {10.1017/S0007485314000820}, pmid = {25424737}, issn = {1475-2670}, mesh = {Animals ; Bacterial Proteins/genetics ; Bacteroidetes/*classification/*genetics ; Bayes Theorem ; Cell Nucleus/genetics ; Chaperonin 60/genetics ; DNA, Bacterial/genetics ; Evolution, Molecular ; Food Chain ; Hemiptera/*classification/*microbiology ; Mitochondria/genetics ; Molecular Sequence Data ; Phylogeny ; Pinus/physiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Armored scale insects and their primary bacterial endosymbionts show nearly identical patterns of co-diversification when viewed at the family level, though the persistence of these patterns at the species level has not been explored in this group. Therefore we investigated genealogical patterns of co-diversification near the species level between the primary endosymbiont Uzinura diaspidicola and its hosts in the Chionaspis pinifoliae-Chionaspis heterophyllae species complex. To do this we generated DNA sequence data from three endosymbiont loci (rspB, GroEL, and 16S) and analyzed each locus independently using statistical parsimony network analyses and as a concatenated dataset using Bayesian phylogenetic reconstructions. We found that for two endosymbiont loci, 16S and GroEL, sequences from U. diaspidicola were broadly associated with host species designations, while for rspB this pattern was less clear as C. heterophyllae (species S1) shared haplotypes with several other Chionaspis species. We then compared the topological congruence of the phylogenetic reconstructions generated from a concatenated dataset of endosymbiont loci (including all three loci, above) to that from a concatenated dataset of armored scale hosts, using published data from two nuclear loci (28S and EF1α) and one mitochondrial locus (COI-COII) from the armored scale hosts. We calculated whether the two topologies were congruent using the Shimodaira-Hasegawa test. We found no significant differences (P = 0.4892) between the topologies suggesting that, at least at this level of resolution, co-diversification of U. diaspidicola with its armored scale hosts also occurs near the species level. This is the first such study of co-speciation at the species level between U. diaspidicola and a group of armored scale insects.}, }
@article {pmid25421434, year = {2014}, author = {Kannan, S and Rogozin, IB and Koonin, EV}, title = {MitoCOGs: clusters of orthologous genes from mitochondria and implications for the evolution of eukaryotes.}, journal = {BMC evolutionary biology}, volume = {14}, number = {}, pages = {237}, pmid = {25421434}, issn = {1471-2148}, support = {//Intramural NIH HHS/United States ; }, mesh = {Alphaproteobacteria/genetics/physiology ; Biological Evolution ; Cell Nucleus/genetics ; Eukaryota/*cytology/*genetics/physiology ; *Evolution, Molecular ; Genes, Mitochondrial ; Introns ; Mitochondria/genetics/physiology ; Symbiosis ; }, abstract = {BACKGROUND: Mitochondria are ubiquitous membranous organelles of eukaryotic cells that evolved from an alpha-proteobacterial endosymbiont and possess a small genome that encompasses from 3 to 106 genes. Accumulation of thousands of mitochondrial genomes from diverse groups of eukaryotes provides an opportunity for a comprehensive reconstruction of the evolution of the mitochondrial gene repertoire.<br><br>RESULTS: Clusters of orthologous mitochondrial protein-coding genes (MitoCOGs) were constructed from all available mitochondrial genomes and complemented with nuclear orthologs of mitochondrial genes. With minimal exceptions, the mitochondrial gene complements of eukaryotes are subsets of the superset of 66 genes found in jakobids. Reconstruction of the evolution of mitochondrial genomes indicates that the mitochondrial gene set of the last common ancestor of the extant eukaryotes was slightly larger than that of jakobids. This superset of mitochondrial genes likely represents an intermediate stage following the loss and transfer to the nucleus of most of the endosymbiont genes early in eukaryote evolution. Subsequent evolution in different lineages involved largely parallel transfer of ancestral endosymbiont genes to the nuclear genome. The intron density in nuclear orthologs of mitochondrial genes typically is nearly the same as in the rest of the genes in the respective genomes. However, in land plants, the intron density in nuclear orthologs of mitochondrial genes is almost 1.5-fold lower than the genomic mean, suggestive of ongoing transfer of functional genes from mitochondria to the nucleus.<br><br>CONCLUSIONS: The MitoCOGs are expected to become an important resource for the study of mitochondrial evolution. The nearly complete superset of mitochondrial genes in jakobids likely represents an intermediate stage in the evolution of eukaryotes after the initial, extensive loss and transfer of the endosymbiont genes. In addition, the bacterial multi-subunit RNA polymerase that is encoded in the jakobid mitochondrial genomes was replaced by a single-subunit phage-type RNA polymerase in the rest of the eukaryotes. These results are best compatible with the rooting of the eukaryotic tree between jakobids and the rest of the eukaryotes. The land plants are the only eukaryotic branch in which the gene transfer from the mitochondrial to the nuclear genome appears to be an active, ongoing process.}, }
@article {pmid25406741, year = {2014}, author = {Reingold, V and Luria, N and Robichon, A and Dombrovsky, A}, title = {Adenine methylation may contribute to endosymbiont selection in a clonal aphid population.}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {999}, pmid = {25406741}, issn = {1471-2164}, mesh = {Adenine/*metabolism ; Animals ; Aphids/*genetics ; Base Sequence ; Clone Cells ; DNA Helicases/genetics ; DNA Methylation/*genetics ; Gene Rearrangement ; Genome, Insect ; Pigmentation/genetics ; Polymerase Chain Reaction ; Reproducibility of Results ; *Selection, Genetic ; Symbiosis/*genetics ; Temperature ; Transposases/genetics ; }, abstract = {BACKGROUND: The pea aphid Acyrthosiphon pisum has two modes of reproduction: parthenogenetic during the spring and summer and sexual in autumn. This ability to alternate between reproductive modes and the emergence of clonal populations under favorable conditions make this organism an interesting model for genetic and epigenetic studies. The pea aphid hosts different types of endosymbiotic bacteria within bacteriocytes which help the aphids survive and adapt to new environmental conditions and habitats. The obligate endosymbiont Buchnera aphidicola has a drastically reduced and stable genome, whereas facultative endosymbionts such as Regiella insecticola have large and dynamic genomes due to phages, mobile elements and high levels of genetic recombination. In previous work, selection toward cold adaptation resulted in the appearance of parthenogenetic A. pisum individuals characterized by heavier weights and remarkable green pigmentation.<br><br>RESULTS: Six adenine-methylated DNA fragments were isolated from genomic DNA (gDNA) extracted from the cold-induced green variant of A. pisum using deoxyadenosine methylase (Dam) by digesting the gDNA with the restriction enzymes DpnI and DpnII, which recognize the methylated and unmethylated GATC sites, respectively. The six resultant fragments did not match any sequence in the A. pisum or Buchnera genomes, implying that they came from facultative endosymbionts. The A1 fragment encoding a putative transposase and the A6 fragment encoding a putative helicase were selected for further comparison between the two A. pisum variants (green and orange) based on Dam analysis followed by PCR amplification. An association between adenine methylation and the two A. pisum variants was demonstrated by higher adenine methylation levels on both genes in the green variant as compared to the orange one.<br><br>CONCLUSION: Temperature selection may affect the secondary endosymbiont and the sensitive Dam involved in the survival and adaptation of aphids to cold temperatures. There is a high degree of adenine methylation at the GATC sites of the endosymbiont genes at 8&#xb0;C, an effect that disappears at 22&#xb0;C. We suggest that endosymbionts can be modified or selected to increase host fitness under unfavorable climatic conditions, and that the phenotype of the newly adapted aphids can be inherited.}, }
@article {pmid25405506, year = {2014}, author = {Avtzis, DN and Doudoumis, V and Bourtzis, K}, title = {Wolbachia infections and mitochondrial diversity of two chestnut feeding Cydia species.}, journal = {PloS one}, volume = {9}, number = {11}, pages = {e112795}, pmid = {25405506}, issn = {1932-6203}, mesh = {Animals ; DNA, Mitochondrial/*genetics ; *Host Specificity ; Moths/*genetics/microbiology ; Phylogeny ; Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {Cydia splendana and C. fagiglandana are two closely related chestnut feeding lepidopteran moth species. In this study, we surveyed the bacterial endosymbiont Wolbachia in these two species. Infection rates were 31% in C. splendana and 77% in C. fagiglandana. MLST analysis showed that these two species are infected with two quite diverse Wolbachia strains. C. splendana with Sequence Type (ST) 409 from the A-supergroup and C. fagiglandana with ST 150 from the B-supergroup. One individual of C. splendana was infected with ST 150, indicating horizontal transfer between these sister species. The mitochondrial DNA of the two Cydia species showed a significantly different mtDNA diversity, which was inversely proportional to their infection rates.}, }
@article {pmid25394184, year = {2016}, author = {Strunov, A and Kiseleva, E}, title = {Drosophila melanogaster brain invasion: pathogenic Wolbachia in central nervous system of the fly.}, journal = {Insect science}, volume = {23}, number = {2}, pages = {253-264}, doi = {10.1111/1744-7917.12187}, pmid = {25394184}, issn = {1744-7917}, mesh = {Animals ; Brain/microbiology/ultrastructure ; Drosophila melanogaster/*microbiology/ultrastructure ; Female ; Microscopy, Electron, Transmission ; Neuroglia/microbiology ; Neurons/microbiology ; Wolbachia/*physiology ; }, abstract = {The pathogenic Wolbachia strain wMelPop rapidly over-replicates in the brain, muscles, and retina of Drosophila melanogaster, causing severe tissue degeneration and premature death of the host. The unique features of this endosymbiont make it an excellent tool to be used for biological control of insects, pests, and vectors of human diseases. To follow the dynamics of bacterial morphology and titer in the nerve cells we used transmission electron microscopy of 3-d-old female brains. The neurons and glial cells from central brain of the fly had different Wolbachia titers ranging from single bacteria to large accumulations, tearing cell apart and invading extracellular space. The neuropile regions of the brain were free of wMelPop. Wolbachia tightly interacted with host cell organelles and underwent several morphological changes in nerve cells. Based on different morphological types of bacteria described we propose for the first time a scheme of wMelPop dynamics within the somatic tissue of the host.}, }
@article {pmid25385629, year = {2014}, author = {O'Connor, RM and Fung, JM and Sharp, KH and Benner, JS and McClung, C and Cushing, S and Lamkin, ER and Fomenkov, AI and Henrissat, B and Londer, YY and Scholz, MB and Posfai, J and Malfatti, S and Tringe, SG and Woyke, T and Malmstrom, RR and Coleman-Derr, D and Altamia, MA and Dedrick, S and Kaluziak, ST and Haygood, MG and Distel, DL}, title = {Gill bacteria enable a novel digestive strategy in a wood-feeding mollusk.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {47}, pages = {E5096-104}, pmid = {25385629}, issn = {1091-6490}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; 1U01TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification ; *Digestion ; *Feeding Behavior ; Gills/*microbiology ; Metagenome ; Molecular Sequence Data ; Mollusca/*metabolism ; Phylogeny ; *Wood ; }, abstract = {Bacteria play many important roles in animal digestive systems, including the provision of enzymes critical to digestion. Typically, complex communities of bacteria reside in the gut lumen in direct contact with the ingested materials they help to digest. Here, we demonstrate a previously undescribed digestive strategy in the wood-eating marine bivalve Bankia setacea, wherein digestive bacteria are housed in a location remote from the gut. These bivalves, commonly known as shipworms, lack a resident microbiota in the gut compartment where wood is digested but harbor endosymbiotic bacteria within specialized cells in their gills. We show that this comparatively simple bacterial community produces wood-degrading enzymes that are selectively translocated from gill to gut. These enzymes, which include just a small subset of the predicted wood-degrading enzymes encoded in the endosymbiont genomes, accumulate in the gut to the near exclusion of other endosymbiont-made proteins. This strategy of remote enzyme production provides the shipworm with a mechanism to capture liberated sugars from wood without competition from an endogenous gut microbiota. Because only those proteins required for wood digestion are translocated to the gut, this newly described system reveals which of many possible enzymes and enzyme combinations are minimally required for wood degradation. Thus, although it has historically had negative impacts on human welfare, the shipworm digestive process now has the potential to have a positive impact on industries that convert wood and other plant biomass to renewable fuels, fine chemicals, food, feeds, textiles, and paper products.}, }
@article {pmid25373153, year = {2014}, author = {Hamm, CA and Handley, CA and Pike, A and Forister, ML and Fordyce, JA and Nice, CC}, title = {Wolbachia infection and Lepidoptera of conservation concern.}, journal = {Journal of insect science (Online)}, volume = {14}, number = {}, pages = {6}, pmid = {25373153}, issn = {1536-2442}, mesh = {Animals ; *Conservation of Natural Resources ; DNA, Bacterial/genetics ; Female ; Lepidoptera/*microbiology ; Male ; Polymerase Chain Reaction ; United States ; Wolbachia/genetics/*physiology ; }, abstract = {Conservation of at-risk species requires multi-faceted and carefully-considered management approaches to be successful. For arthropods, the presence of endosymbiotic bacteria, such as Wolbachia (Rickettsiales: Rickettsiaceae), may complicate management plans and exacerbate the challenges faced by conservation managers. Wolbachia poses a substantial and underappreciated threat to the conservation of arthropods because infection may induce a number of phenotypic effects, most of which are considered deleterious to the host population. In this study, the prevalence of Wolbachia infection in lepidopteran species of conservation concern was examined. Using standard molecular techniques, 22 species of Lepidoptera were screened, of which 19 were infected with Wolbachia. This rate is comparable to that observed in insects as a whole. However, this is likely an underestimate because geographic sampling was not extensive and may not have included infected segments of the species' ranges. Wolbachia infections may be particularly problematic for conservation management plans that incorporate captive propagation or translocation. Inadvertent introduction of Wolbachia into uninfected populations or introduction of a new strain may put these populations at greater risk for extinction. Further sampling to investigate the geographic extent of Wolbachia infections within species of conservation concern and experiments designed to determine the nature of the infection phenotype(s) are necessary to manage the potential threat of infection.}, }
@article {pmid25369873, year = {2014}, author = {van Zyl, LJ and Schubert, WD and Tuffin, MI and Cowan, DA}, title = {Structure and functional characterization of pyruvate decarboxylase from Gluconacetobacter diazotrophicus.}, journal = {BMC structural biology}, volume = {14}, number = {}, pages = {21}, pmid = {25369873}, issn = {1472-6807}, mesh = {Amino Acids/*metabolism ; Bacterial Proteins/*chemistry/*metabolism ; Crystallography, X-Ray ; Gluconacetobacter/chemistry/*enzymology ; Models, Molecular ; Phylogeny ; Protein Conformation ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Pyruvate Decarboxylase/*chemistry/*metabolism ; Sarcina/chemistry/enzymology ; Sequence Homology, Amino Acid ; Substrate Specificity ; Zymomonas/chemistry/enzymology ; }, abstract = {BACKGROUND: Bacterial pyruvate decarboxylases (PDC) are rare. Their role in ethanol production and in bacterially mediated ethanologenic processes has, however, ensured a continued and growing interest. PDCs from Zymomonas mobilis (ZmPDC), Zymobacter palmae (ZpPDC) and Sarcina ventriculi (SvPDC) have been characterized and ZmPDC has been produced successfully in a range of heterologous hosts. PDCs from the Acetobacteraceae and their role in metabolism have not been characterized to the same extent. Examples include Gluconobacter oxydans (GoPDC), G. diazotrophicus (GdPDC) and Acetobacter pasteutrianus (ApPDC). All of these organisms are of commercial importance.<br><br>RESULTS: This study reports the kinetic characterization and the crystal structure of a PDC from Gluconacetobacter diazotrophicus (GdPDC). Enzyme kinetic analysis indicates a high affinity for pyruvate (K M 0.06 mM at pH 5), high catalytic efficiencies (1.3 &#x2022; 10(6) M(-1) &#x2022; s(-1) at pH 5), pHopt of 5.5 and Topt at 45&#xb0;C. The enzyme is not thermostable (T&#xbd; of 18 minutes at 60&#xb0;C) and the calculated number of bonds between monomers and dimers do not give clear indications for the relatively lower thermostability compared to other PDCs. The structure is highly similar to those described for Z. mobilis (ZmPDC) and A. pasteurianus PDC (ApPDC) with a rmsd value of 0.57 &#xc5; for C&#x3b1; when comparing GdPDC to that of ApPDC. Indole-3-pyruvate does not serve as a substrate for the enzyme. Structural differences occur in two loci, involving the regions Thr341 to Thr352 and Asn499 to Asp503.<br><br>CONCLUSIONS: This is the first study of the PDC from G. diazotrophicus (PAL5) and lays the groundwork for future research into its role in this endosymbiont. The crystal structure of GdPDC indicates the enzyme to be evolutionarily closely related to homologues from Z. mobilis and A. pasteurianus and suggests strong selective pressure to keep the enzyme characteristics in a narrow range. The pH optimum together with reduced thermostability likely reflect the host organisms niche and conditions under which these properties have been naturally selected for. The lack of activity on indole-3-pyruvate excludes this decarboxylase as the enzyme responsible for indole acetic acid production in G. diazotrophicus.}, }
@article {pmid25368078, year = {2014}, author = {Pistone, D and Bione, A and Epis, S and Pajoro, M and Gaiarsa, S and Bandi, C and Sassera, D}, title = {Presence of Wolbachia in three hymenopteran species: Diprion pini (Hymenoptera: Diprionidae), Neodiprion sertifer (Hymenoptera: Diprionidae), and Dahlbominus fuscipennis (Hymenoptera: Eulophidae).}, journal = {Journal of insect science (Online)}, volume = {14}, number = {}, pages = {147}, pmid = {25368078}, issn = {1536-2442}, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Hot Temperature ; Hymenoptera/anatomy &amp; histology/*microbiology/*physiology ; Italy ; Male ; Mosaicism ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sex Characteristics ; Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Sawflies are important pests of various plant species. Diprion pini (L.) and Neodiprion sertifer (Geoffroy) (Hymenoptera: Diprionidae) are two of the most important sawfly pests in Italy, and both species are parasitized by the hymenopteran parasitoid Dahlbominus fuscipennis (Zetterstedt). Bacterial endosymbionts are currently studied for their high potential in strategies of biocontrol in a number of insect species. In this study, we investigated the presence of symbiotic bacteria (Wolbachia and Cardinium) in the three species of hymenoptera mentioned earlier, both in wild and laboratory populations. Although all samples were negative for the presence of Cardinium, 100% prevalence for Wolbachia was detected, as all examined individuals resulted to be PCR positive. Furthermore, 16S rDNA and ftsZ gene sequencing indicated that all individuals from the three hymenopteran species are infected by a single Wolbachia strain. Additionally, we report the presence of gynandromorphic individuals in D. pini, both in wild and laboratory-reared populations. Heat treatments on D. pini colonies removed the Wolbachia symbionts, but they also prevented the development of adults.}, }
@article {pmid25367138, year = {2015}, author = {Ong, HB and Lee, WS and Patterson, S and Wyllie, S and Fairlamb, AH}, title = {Homoserine and quorum-sensing acyl homoserine lactones as alternative sources of threonine: a potential role for homoserine kinase in insect-stage Trypanosoma brucei.}, journal = {Molecular microbiology}, volume = {95}, number = {1}, pages = {143-156}, pmid = {25367138}, issn = {1365-2958}, support = {079838//Wellcome Trust/United Kingdom ; 083481/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Acyl-Butyrolactones/*metabolism ; Animals ; Carbon-Oxygen Lyases/genetics/*metabolism ; Homoserine/*metabolism ; Mutation ; Phosphorylation ; Phosphotransferases (Alcohol Group Acceptor)/genetics/*metabolism ; Quorum Sensing ; Symbiosis ; Threonine/metabolism ; Trypanosoma brucei brucei/enzymology/genetics/*physiology ; Tsetse Flies/*microbiology/parasitology ; }, abstract = {De novo synthesis of threonine from aspartate occurs via the β-aspartyl phosphate pathway in plants, bacteria and fungi. However, the Trypanosoma brucei genome encodes only the last two steps in this pathway: homoserine kinase (HSK) and threonine synthase. Here, we investigated the possible roles for this incomplete pathway through biochemical, genetic and nutritional studies. Purified recombinant TbHSK specifically phosphorylates L-homoserine and displays kinetic properties similar to other HSKs. HSK null mutants generated in bloodstream forms displayed no growth phenotype in vitro or loss of virulence in vivo. However, following transformation into procyclic forms, homoserine, homoserine lactone and certain acyl homoserine lactones (AHLs) were found to substitute for threonine in growth media for wild-type procyclics, but not HSK null mutants. The tsetse fly is considered to be an unlikely source of these nutrients as it feeds exclusively on mammalian blood. Bioinformatic studies predict that tsetse endosymbionts possess part (up to homoserine in Wigglesworthia glossinidia) or all of the β-aspartyl phosphate pathway (Sodalis glossinidius). In addition S. glossinidius is known to produce 3-oxohexanoylhomoserine lactone which also supports trypanosome growth. We propose that T. brucei has retained HSK and threonine synthase in order to salvage these nutrients when threonine availability is limiting.}, }
@article {pmid25365330, year = {2014}, author = {Kollenberg, M and Winter, S and Götz, M}, title = {Quantification and localization of Watermelon chlorotic stunt virus and Tomato yellow leaf curl virus (Geminiviridae) in populations of Bemisia tabaci (Hemiptera, Aleyrodidae) with differential virus transmission characteristics.}, journal = {PloS one}, volume = {9}, number = {11}, pages = {e111968}, pmid = {25365330}, issn = {1932-6203}, mesh = {Animals ; *Geminiviridae ; Hemiptera/*virology ; Insect Vectors/*virology ; Intestines/*virology ; Plant Diseases/*virology ; Salivary Glands/*virology ; }, abstract = {Bemisia tabaci (Gennadius) is one of the economically most damaging insects to crops in tropical and subtropical regions. Severe damage is caused by feeding and more seriously by transmitting viruses. Those of the genus begomovirus (Geminiviridae) cause the most significant crop diseases and are transmitted by B. tabaci in a persistent circulative mode, a process which is largely unknown. To analyze the translocation and to identify critical determinants for transmission, two populations of B. tabaci MEAM1 were compared for transmitting Watermelon chlorotic stunt virus (WmCSV) and Tomato yellow leaf curl virus (TYLCV). Insect populations were chosen because of their high and respectively low virus transmission efficiency to compare uptake and translocation of virus through insects. Both populations harbored Rickettsia, Hamiltonella and Wolbachia in comparable ratios indicating that endosymbionts might not contribute to the different transmission rates. Quantification by qPCR revealed that WmCSV uptake and virus concentrations in midguts and primary salivary glands were generally higher than TYLCV due to higher virus contents of the source plants. Both viruses accumulated higher in insects from the efficiently compared to the poorly transmitting population. In the latter, virus translocation into the hemolymph was delayed and virus passage was impeded with limited numbers of viruses translocated. FISH analysis confirmed these results with similar virus distribution found in excised organs of both populations. No virus accumulation was found in the midgut lumen of the poor transmitter because of a restrained virus translocation. Results suggest that the poorly transmitting population comprised insects that lacked transmission competence. Those were selected to develop a population that lacks virus transmission. Investigations with insects lacking transmission showed that virus concentrations in midguts were reduced and only negligible virus amounts were found at the primary salivary glands indicating for a missing or modified receptor responsible for virus attachment or translocation.}, }
@article {pmid25360267, year = {2014}, author = {Burdfield-Steel, ER and Shuker, DM}, title = {The evolutionary ecology of the Lygaeidae.}, journal = {Ecology and evolution}, volume = {4}, number = {11}, pages = {2278-2301}, pmid = {25360267}, issn = {2045-7758}, abstract = {The Lygaeidae (sensu lato) are a highly successful family of true bugs found worldwide, yet many aspects of their ecology and evolution remain obscure or unknown. While a few species have attracted considerable attention as model species for the study of insect physiology, it is only relatively recently that biologists have begun to explore aspects of their behavior, life history evolution, and patterns of intra- and interspecific ecological interactions across more species. As a result though, a range of new phenotypes and opportunities for addressing current questions in evolutionary ecology has been uncovered. For example, researchers have revealed hitherto unexpectedly rich patterns of bacterial symbiosis, begun to explore the evolutionary function of the family's complex genitalia, and also found evidence of parthenogenesis. Here we review our current understanding of the biology and ecology of the group as a whole, focusing on several of the best-studied characteristics of the group, including aposematism (i.e., the evolution of warning coloration), chemical communication, sexual selection (especially, postcopulatory sexual selection), sexual conflict, and patterns of host-endosymbiont coevolution. Importantly, many of these aspects of lygaeid biology are likely to interact, offering new avenues for research, for instance into how the evolution of aposematism influences sexual selection. With the growing availability of genomic tools for previously "non-model" organisms, combined with the relative ease of keeping many of the polyphagous species in the laboratory, we argue that these bugs offer many opportunities for behavioral and evolutionary ecologists.}, }
@article {pmid25347417, year = {2014}, author = {Carvalho, GA and Vieira, JL and Haro, MM and Corrêa, AS and Ribon, AO and de Oliveira, LO and Guedes, RN}, title = {Pleiotropic impact of endosymbiont load and co-occurrence in the maize weevil Sitophilus zeamais.}, journal = {PloS one}, volume = {9}, number = {10}, pages = {e111396}, pmid = {25347417}, issn = {1932-6203}, mesh = {Animals ; Bacterial Load ; Coleoptera/*microbiology/physiology ; Locomotion ; Reproduction ; *Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {Individual traits vary among and within populations, and the co-occurrence of different endosymbiont species within a host may take place under varying endosymbiont loads in each individual host. This makes the recognition of the potential impact of such endosymbiont associations in insect species difficult, particularly in insect pest species. The maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae), a key pest species of stored cereal grains, exhibits associations with two endosymbiotic bacteria: the obligatory endosymbiont SZPE ("Sitophilus zeamais Primary Endosymbiont") and the facultative endosymbiont Wolbachia. The impact of the lack of SZPE in maize weevil physiology is the impairment of nutrient acquisition and energy metabolism, while Wolbachia is an important factor in reproductive incompatibility. However, the role of endosymbiont load and co-occurrence in insect behavior, grain consumption, body mass and subsequent reproductive factors has not yet been explored. Here we report on the impacts of co-occurrence and varying endosymbiont loads achieved via thermal treatment and antibiotic provision via ingested water in the maize weevil. SZPE exhibited strong effects on respiration rate, grain consumption and weevil body mass, with observed effects on weevil behavior, particularly flight activity, and potential consequences for the management of this pest species. Wolbachia directly favored weevil fertility and exhibited only mild indirect effects, usually enhancing the SZPE effect. SZPE suppression delayed weevil emergence, which reduced the insect population growth rate, and the thermal inactivation of both symbionts prevented insect reproduction. Such findings are likely important for strain divergences reported in the maize weevil and their control, aspects still deserving future attention.}, }
@article {pmid25342549, year = {2014}, author = {Dmytrenko, O and Russell, SL and Loo, WT and Fontanez, KM and Liao, L and Roeselers, G and Sharma, R and Stewart, FJ and Newton, IL and Woyke, T and Wu, D and Lang, JM and Eisen, JA and Cavanaugh, CM}, title = {The genome of the intracellular bacterium of the coastal bivalve, Solemya velum: a blueprint for thriving in and out of symbiosis.}, journal = {BMC genomics}, volume = {15}, number = {}, pages = {924}, pmid = {25342549}, issn = {1471-2164}, mesh = {Animals ; Base Composition/genetics ; Bivalvia/*microbiology ; DNA Transposable Elements/genetics ; *Ecosystem ; Genes, Bacterial ; *Genome, Bacterial ; Intracellular Space/*microbiology ; Metabolic Networks and Pathways/genetics ; Molecular Sequence Data ; Oxidation-Reduction ; RNA, Transfer/genetics ; *Symbiosis ; }, abstract = {BACKGROUND: Symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. These associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. Due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of chemosynthetic symbioses rely heavily on culture independent methods. The symbiosis between the coastal bivalve, Solemya velum, and its intracellular symbiont is a model for chemosynthetic symbioses given its accessibility in intertidal environments and the ability to maintain it under laboratory conditions. To better understand this symbiosis, the genome of the S. velum endosymbiont was sequenced.<br><br>RESULTS: Relative to the genomes of obligate symbiotic bacteria, which commonly undergo erosion and reduction, the S. velum symbiont genome was large (2.7&#xa0;Mb), GC-rich (51%), and contained a large number (78) of mobile genetic elements. Comparative genomics identified sets of genes specific to the chemosynthetic lifestyle and necessary to sustain the symbiosis. In addition, a number of inferred metabolic pathways and cellular processes, including heterotrophy, branched electron transport, and motility, suggested that besides the ability to function as an endosymbiont, the bacterium may have the capacity to live outside the host.<br><br>CONCLUSIONS: The physiological dexterity indicated by the genome substantially improves our understanding of the genetic and metabolic capabilities of the S. velum symbiont and the breadth of niches the partners may inhabit during their lifecycle.}, }
@article {pmid25342114, year = {2015}, author = {Tavormina, PL and Hatzenpichler, R and McGlynn, S and Chadwick, G and Dawson, KS and Connon, SA and Orphan, VJ}, title = {Methyloprofundus sedimenti gen. nov., sp. nov., an obligate methanotroph from ocean sediment belonging to the 'deep sea-1' clade of marine methanotrophs.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {65}, number = {Pt 1}, pages = {251-259}, doi = {10.1099/ijs.0.062927-0}, pmid = {25342114}, issn = {1466-5034}, mesh = {Bacterial Typing Techniques ; Base Composition ; California ; DNA, Bacterial/genetics ; Fatty Acids/chemistry ; Geologic Sediments/*microbiology ; Methane/metabolism ; Methylococcaceae/*classification/genetics/isolation &amp; purification ; Molecular Sequence Data ; Pacific Ocean ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sequence Analysis, DNA ; }, abstract = {We report the isolation and growth characteristics of a gammaproteobacterial methane-oxidizing bacterium (Methylococcaceae strain WF1(T), 'whale fall 1') that shares 98 % 16S rRNA gene sequence identity with uncultivated free-living methanotrophs and the methanotrophic endosymbionts of deep-sea mussels, ≤94.6 % 16S rRNA gene sequence identity with species of the genus Methylobacter and ≤93.6 % 16S rRNA gene sequence identity with species of the genera Methylomonas and Methylosarcina. Strain WF1(T) represents the first cultivar from the 'deep sea-1' clade of marine methanotrophs, which includes members that participate in methane oxidation in sediments and the water column in addition to mussel endosymbionts. Cells of strain WF1(T) were elongated cocci, approximately 1.5 µm in diameter, and occurred singly, in pairs and in clumps. The cell wall was Gram-negative, and stacked intracytoplasmic membranes and storage granules were evident. The genomic DNA G+C content of WF1(T) was 40.5 mol%, significantly lower than that of currently described cultivars, and the major fatty acids were 16 : 0, 16 : 1ω9c, 16 : 1ω9t, 16 : 1ω8c and 16 : 2ω9,14. Growth occurred in liquid media at an optimal temperature of 23 °C, and was dependent on the presence of methane or methanol. Atmospheric nitrogen could serve as the sole nitrogen source for WF1(T), a capacity that had not been functionally demonstrated previously in members of Methylobacter. On the basis of its unique morphological, physiological and phylogenetic properties, this strain represents the type species within a new genus, and we propose the name Methyloprofundus sedimenti gen. nov., sp. nov. The type strain of Methyloprofundus sedimenti is WF1(T) (= LMG 28393(T) = ATCC BAA-2619(T)).}, }
@article {pmid25329881, year = {2014}, author = {Ivanov, S and Harrison, MJ}, title = {A set of fluorescent protein-based markers expressed from constitutive and arbuscular mycorrhiza-inducible promoters to label organelles, membranes and cytoskeletal elements in Medicago truncatula.}, journal = {The Plant journal : for cell and molecular biology}, volume = {80}, number = {6}, pages = {1151-1163}, doi = {10.1111/tpj.12706}, pmid = {25329881}, issn = {1365-313X}, mesh = {Biological Transport ; Biomarkers/metabolism ; Cell Membrane/metabolism ; Cytoskeleton/metabolism ; *Gene Expression Regulation, Plant ; Hyphae/genetics ; Medicago truncatula/genetics/*microbiology ; Microtubules/metabolism ; Mycorrhizae/*physiology ; Organelles/metabolism ; Phosphate Transport Proteins/genetics ; Plant Proteins/genetics/metabolism ; Plant Roots/genetics/metabolism ; Plants, Genetically Modified ; Promoter Regions, Genetic/physiology ; *Symbiosis ; trans-Golgi Network/metabolism ; }, abstract = {Medicago truncatula is widely used for analyses of arbuscular mycorrhizal (AM) symbiosis and nodulation. To complement the genetic and genomic resources that exist for this species, we generated fluorescent protein fusions that label the nucleus, endoplasmic reticulum, Golgi apparatus, trans-Golgi network, plasma membrane, apoplast, late endosome/multivesicular bodies (MVB), transitory late endosome/ tonoplast, tonoplast, plastids, mitochondria, peroxisomes, autophagosomes, plasmodesmata, actin, microtubules, periarbuscular membrane (PAM) and periarbuscular apoplastic space (PAS) and expressed them from the constitutive AtUBQ10 promoter and the AM symbiosis-specific MtBCP1 promoter. All marker constructs showed the expected expression patterns and sub-cellular locations in M. truncatula root cells. As a demonstration of their utility, we used several markers to investigate AM symbiosis where root cells undergo major cellular alterations to accommodate their fungal endosymbiont. We demonstrate that changes in the position and size of the nuclei occur prior to hyphal entry into the cortical cells and do not require DELLA signaling. Changes in the cytoskeleton, tonoplast and plastids also occur in the colonized cells and in contrast to previous studies, we show that stromulated plastids are abundant in cells with developing and mature arbuscules, while lens-shaped plastids occur in cells with degenerating arbuscules. Arbuscule development and secretion of the PAM creates a periarbuscular apoplastic compartment which has been assumed to be continuous with apoplast of the cell. However, fluorescent markers secreted to the periarbuscular apoplast challenge this assumption. This marker resource will facilitate cell biology studies of AM symbiosis, as well as other aspects of legume biology.}, }
@article {pmid25301324, year = {2015}, author = {Arthan, W and Sumrandee, C and Hirunkanokpun, S and Kitthawee, S and Baimai, V and Trinachartvanit, W and Ahantarig, A}, title = {Detection of Coxiella-like endosymbiont in Haemaphysalis tick in Thailand.}, journal = {Ticks and tick-borne diseases}, volume = {6}, number = {1}, pages = {63-68}, doi = {10.1016/j.ttbdis.2014.09.005}, pmid = {25301324}, issn = {1877-9603}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Coxiella/classification/genetics/*isolation &amp; purification ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Ixodidae/*microbiology ; Male ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {In this study, we focused on the molecular detection of Coxiella-like bacteria using a PCR technique to identify Coxiella 16S rRNA sequences in Haemaphysalis tick samples (105 adults, 8 nymph pools and 19 larval pools). Seven Haemaphysalis species obtained from 5 locations in Thailand were evaluated in this work. Coxiella endosymbionts could be detected in samples representing all 3 growth stages examined. The results also revealed that only 4 of 7 tick species were positive for Coxiella-like endosymbiont: Haemaphysalis hystricis, Haemaphysalis lagrangei, Haemaphysalis obesa, and Haemaphysalis shimoga. Haemaphysalis shimoga demonstrated the highest percentage of Coxiella-like positive samples (58.33% with n=24), while Haemaphysalis hystricis had the lowest percentage; only 1 female tick was positive for Coxiella-like bacteria (n=6). Interestingly, the results indicated that female Haemaphysalis ticks tended to harbour Coxiella symbionts more frequently than male ticks (59.32% of females and 21.27% of males of all species studied). Phylogenetic analyses based on 16S rRNA sequences illustrated that Coxiella-like spp. from the same tick species always grouped in same clade, regardless of the location from which they were isolated. Moreover, a phylogenetic tree also showed that Coxiella-like endosymbionts from other genera (for example, the tick genus Rhipicephalus) formed a separate group compared to Coxiella-like symbionts in the genus Haemaphysalis. This suggests that a high amount of DNA sequence variation is present in Coxiella-like bacteria harboured by ticks.}, }
@article {pmid25297658, year = {2015}, author = {Kapantaidaki, DE and Ovčarenko, I and Fytrou, N and Knott, KE and Bourtzis, K and Tsagkarakou, A}, title = {Low levels of mitochondrial DNA and symbiont diversity in the worldwide agricultural pest, the greenhouse whitefly Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).}, journal = {The Journal of heredity}, volume = {106}, number = {1}, pages = {80-92}, doi = {10.1093/jhered/esu061}, pmid = {25297658}, issn = {1465-7333}, mesh = {*Animal Distribution ; Animals ; Bacteria/*genetics ; Base Sequence ; DNA, Mitochondrial/*genetics ; Female ; *Genetic Variation ; Hemiptera/*genetics/microbiology ; Likelihood Functions ; Male ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Phylogeography ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Trialeurodes vaporariorum, the greenhouse whitefly, is a cosmopolitan agricultural pest. Little is known about the genetic diversity of T. vaporariorum and the bacterial symbionts associated with this species. Here, we undertook a large phylogeographic study by investigating both the mitochondrial (mt) diversity and the infection status of 38 T. vaporariorum collections from 18 countries around the world. Genetic diversity of T. vaporariorum was studied by analyzing sequence data from the mt cytochrome oxidase I, cytochrome b, and NADH dehydrogenase subunit 5 genes. Maximum-likelihood (ML) phylogeny reconstruction delineated 2 clades characterized by limited sequence divergence: one clade comprised samples only from the Northern hemisphere whereas the other comprised samples from a broader geographical range. The presence of secondary symbionts was determined by PCR using primers specific for Hamiltonella, Rickettsia, Arsenophonus, Cardinium, Wolbachia, and Fritschea. Most individuals examined harbored at least one secondary endosymbiont, and Arsenophonus was detected in almost all male and female individuals. Wolbachia was present at a much lower frequency, and Cardinium was detected in only a few individuals from Greece. Rickettsia, Hamiltonella, and Fritschea were not found. Additionally, we set out to further analyze Arsenophonus diversity by multilocus sequence typing analysis; however, the Arsenophonus sequences did not exhibit any polymorphism. Our results revealed remarkably low diversity in both mtDNA and symbionts in this worldwide agricultural pest, contrasting sharply with that of the ecologically similar Bemisia tabaci.}, }
@article {pmid25259930, year = {2014}, author = {Marubayashi, JM and Kliot, A and Yuki, VA and Rezende, JA and Krause-Sakate, R and Pavan, MA and Ghanim, M}, title = {Diversity and localization of bacterial endosymbionts from whitefly species collected in Brazil.}, journal = {PloS one}, volume = {9}, number = {9}, pages = {e108363}, pmid = {25259930}, issn = {1932-6203}, mesh = {Animals ; Brazil ; Enterobacteriaceae/*genetics ; Hemiptera/*microbiology ; Molecular Sequence Data ; Symbiosis/*genetics ; }, abstract = {Whiteflies (Hemiptera: Aleyrodidae) are sap-sucking insect pests, and some cause serious damage in agricultural crops by direct feeding and by transmitting plant viruses. Whiteflies maintain close associations with bacterial endosymbionts that can significantly influence their biology. All whitefly species harbor a primary endosymbiont, and a diverse array of secondary endosymbionts. In this study, we surveyed 34 whitefly populations collected from the states of Sao Paulo, Bahia, Minas Gerais and Parana in Brazil, for species identification and for infection with secondary endosymbionts. Sequencing the mitochondrial Cytochrome Oxidase I gene revealed the existence of five whitefly species: The sweetpotato whitefly Bemisia tabaci B biotype (recently termed Middle East-Asia Minor 1 or MEAM1), the greenhouse whitefly Trialeurodes vaporariorum, B. tabaci A biotype (recently termed New World 2 or NW2) collected only from Euphorbia, the Acacia whitefly Tetraleurodes acaciae and Bemisia tuberculata both were detected only on cassava. Sequencing rRNA genes showed that Hamiltonella and Rickettsia were highly prevalent in all MEAM1 populations, while Cardinium was close to fixation in only three populations. Surprisingly, some MEAM1 individuals and one NW2 population were infected with Fritschea. Arsenopnohus was the only endosymbiont detected in T. vaporariorum. In T. acaciae and B. tuberculata populations collected from cassava, Wolbachia was fixed in B. tuberculata and was highly prevalent in T. acaciae. Interestingly, while B. tuberculata was additionally infected with Arsenophonus, T. acaciae was infected with Cardinium and Fritschea. Fluorescence in situ hybridization analysis on representative individuals showed that Hamiltonella, Arsenopnohus and Fritschea were localized inside the bacteriome, Cardinium and Wolbachia exhibited dual localization patterns inside and outside the bacteriome, and Rickettsia showed strict localization outside the bacteriome. This study is the first survey of whitely populations collected in Brazil, and provides further insights into the complexity of infection with secondary endosymionts in whiteflies.}, }
@article {pmid25252453, year = {2014}, author = {Rao, Q and Wu, H}, title = {[Advances in insect obligate endosymbionts and their genomes--a review].}, journal = {Wei sheng wu xue bao = Acta microbiologica Sinica}, volume = {54}, number = {7}, pages = {728-736}, pmid = {25252453}, issn = {0001-6209}, mesh = {Animals ; Bacteria/classification/*genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; *Genome, Bacterial ; Insecta/*microbiology/physiology ; *Symbiosis ; }, abstract = {In nature, many insects, especially sap-feeding insects, harbor nutritional bacterial symbionts, which are called obligate endosymbionts. These bacteria co-evolved with their hosts for millions of years. Obligate endosymbionts are commonly found in specialized organs, named bacteriomes or mycetomes that consist of a number of insect's cells (bacteriocytes or mycetocytes). Obligate endosymbionts strictly maternally inherited, providing essential amino acids to the hosts, and relating to survival, reproduction and evolution of the insects. Because of enriched nutritional environment, compared to those free-living bacteria, the genomes of obligate endosymbionts have different characteristics, such as genome size, GC content, and gene deletion. Although the genomes of many insect endosymbionts have been carefully analysis, the gene functions of endosymbionts and the interactions between endosymbionts/hosts and endosymbionts remain unknown. Thus, to provide an insight into the co-evolution of endosymbionts and their hosts, further studies of endosymbionts at genetic level are required.}, }
@article {pmid25249342, year = {2014}, author = {Martínez-Rodríguez, P and Granero-Belinchón, R and Arroyo-Yebras, F and Bella, JL}, title = {New insight into Wolbachia epidemiology: its varying incidence during the host life cycle can alter bacteria spread.}, journal = {Bulletin of mathematical biology}, volume = {76}, number = {10}, pages = {2646-2663}, doi = {10.1007/s11538-014-0029-5}, pmid = {25249342}, issn = {1522-9602}, mesh = {Animals ; Biological Evolution ; Computer Simulation ; Female ; Grasshoppers/growth &amp; development/microbiology/physiology ; Host-Pathogen Interactions ; Life Cycle Stages ; Male ; Mathematical Concepts ; Models, Biological ; Reproduction ; Symbiosis ; Wolbachia/pathogenicity/*physiology ; }, abstract = {Wolbachia is an obligate endosymbiont whose spread depends mainly on its capacity to alter host reproduction by, for instance, cytoplasmic incompatibility. Several mathematical models have been developed to explain the dynamics of bacterial spread, because of its applied interest. However, some aspects of the host's and bacterium's biology have not been considered in modelling: for instance, changes in Wolbachia proportions during the host's life cycle have been observed in several species, including Drosophila sp., Nasonia sp. and Aedes sp. (Diptera), but also in the grasshopper Chorthippus parallelus (Orthoptera), the species studied in this article. These changes influence the proportion of incompatible crosses and, consequently, infection prevalence in subsequent generations. In this paper, we are interested in ascertaining whether these changes in the infection proportions during the host's life cycle can influence the dynamics of the spread of these bacteria. We have examined its consequences using a mathematical model to predict the evolution of Wolbachia infection frequencies. The simulations were validated by experimental field data from C. parallelus. The main outcome is that those changes above mentioned might affect long-term infection spread, with possible consequences for the current distribution of Wolbachia and the way it affects its host's reproduction.}, }
@article {pmid25248027, year = {2014}, author = {Dirren, S and Salcher, MM and Blom, JF and Schweikert, M and Posch, T}, title = {Ménage-à-trois: the amoeba Nuclearia sp. from Lake Zurich with its ecto- and endosymbiotic bacteria.}, journal = {Protist}, volume = {165}, number = {5}, pages = {745-758}, doi = {10.1016/j.protis.2014.08.004}, pmid = {25248027}, issn = {1618-0941}, mesh = {Amoeba/classification/cytology/*isolation &amp; purification/*microbiology ; Betaproteobacteria/*classification/*isolation &amp; purification/physiology ; DNA, Bacterial/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Gammaproteobacteria/*classification/*isolation &amp; purification/physiology ; Genes, rRNA ; Lakes/parasitology ; Molecular Sequence Data ; RNA, Protozoan/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Switzerland ; *Symbiosis ; }, abstract = {We present a fascinating triad relationship between a eukaryotic amoeba and its two bacterial symbionts. The morphological characteristics of the amoeba allowed for a confident assignment to the genus Nuclearia (Opisthokonta, Nucleariidae), but species identification resulted in an ambiguous result. Sequence analysis indicated an affiliation to the species N. thermophila, however, several morphological features contradict the original description. Amoebal isolates were cultured for several years with their preferred food source, the microcystin-producing harmful cyanobacterium Planktothrix rubescens. Symbioses of the amoeba with ecto- and endosymbiotic bacteria were maintained over this period. Several thousand cells of the ectosymbiont are regularly arranged inside a layer of extracellular polymeric substances produced by the amoeba. The ectosymbiont was identified as Paucibacter toxinivorans (Betaproteobacteria), which was originally isolated by enrichment with microcystins. We found indications that our isolated ectosymbiont indeed contributed to toxin-degradation. The endosymbiont (Gammaproteobacteria, 15-20 bacteria per amoeba) is enclosed in symbiosomes inside the host cytoplasm and represents probably an obligate symbiont. We propose the name "Candidatus Endonucleariobacter rarus" for this bacterium that was neither found free-living nor in a symbiotic association. Nucleariidae are uniquely suited model organisms to study the basic principles of symbioses between opisthokonts and prokaryotes.}, }
@article {pmid25243758, year = {2014}, author = {Young, ND and Dyková, I and Crosbie, PB and Wolf, M and Morrison, RN and Bridle, AR and Nowak, BF}, title = {Support for the coevolution of Neoparamoeba and their endosymbionts, Perkinsela amoebae-like organisms.}, journal = {European journal of protistology}, volume = {50}, number = {5}, pages = {509-523}, doi = {10.1016/j.ejop.2014.07.004}, pmid = {25243758}, issn = {1618-0429}, mesh = {Amoebozoa/genetics/*parasitology ; DNA, Ribosomal Spacer/genetics ; Kinetoplastida/*classification/genetics/*physiology ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 18S/genetics ; *Symbiosis ; }, abstract = {Some of the species from the genus Neoparamoeba, for example N. perurans have been shown to be pathogenic to aquatic animals and thus have economic significance. They all contain endosymbiont, Perkinsela amoebae like organisms (PLOs). In this study we investigated phylogenetic ambiguities within the Neoparamoeba taxonomy and phylogenetic congruence between PLOs and their host Neoparamoeba to confirm the existence of a single ancient infection/colonisation that led to cospeciation between all PLOs and their host Neoparamoeba. DNA was extracted and rRNA genes from host amoeba and endosymbiont were amplified using PCR. Uncertainties in the Neoparamoeba phylogeny were initially resolved by a secondary phylogenetic marker, the internal transcribed spacer 2 (ITS2). The secondary structure of ITS2 was reconstructed for Neoparamoeba. The ITS2 was phylogenetically informative, separating N. pemaquidensis and N. aestuarina into distinct monophyletic clades and designating N. perurans as the most phylogenetically divergent Neoparamoeba species. The new phylogenetic data were used to verify the tree topologies used in cophylogenetic analyses that revealed strict phylogenetic congruence between endosymbiotic PLOs with their host Neoparamoeba. Strict congruence in the phylogeny of all PLOs and their host Neoparamoeba was demonstrated implying that PLOs are transmitted vertically from parent to daughter cell.}, }
@article {pmid25242028, year = {2014}, author = {Vigneron, A and Masson, F and Vallier, A and Balmand, S and Rey, M and Vincent-Monégat, C and Aksoy, E and Aubailly-Giraud, E and Zaidman-Rémy, A and Heddi, A}, title = {Insects recycle endosymbionts when the benefit is over.}, journal = {Current biology : CB}, volume = {24}, number = {19}, pages = {2267-2273}, doi = {10.1016/j.cub.2014.07.065}, pmid = {25242028}, issn = {1879-0445}, mesh = {Animals ; Bacterial Proteins/genetics ; Electron Transport Complex I/genetics ; Enterobacteriaceae/genetics/metabolism/*physiology ; Female ; Larva/microbiology ; Male ; Molecular Sequence Data ; Pupa/microbiology ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Symbiosis ; Weevils/growth &amp; development/*microbiology ; }, abstract = {Symbiotic associations are widespread in nature and represent a driving force in evolution. They are known to impact fitness, and thereby shape the host phenotype. Insects subsisting on nutritionally poor substrates have evolved mutualistic relationships with intracellular symbiotic bacteria (endosymbionts) that supply them with metabolic components lacking in their diet. In many species, endosymbionts are hosted within specialized host cells, called the bacteriocytes, and transmitted vertically across host generations. How hosts balance the costs and benefits of having endosymbionts, and whether and how they adjust symbiont load to their physiological needs, remains largely unexplored. By investigating the cereal weevil Sitophilus association with the Sodalis pierantonius endosymbiont, we discover that endosymbiont populations intensively multiply in young adults, before being rapidly eliminated within few days. We show that young adults strongly depend on endosymbionts and that endosymbiont proliferation after metamorphosis matches a drastic host physiological need for the tyrosine (Tyr) and phenylalanine (Phe) amino acids to rapidly build their protective exoskeleton. Tyr and Phe are precursors of the dihydroxyphenylalanine (DOPA) molecule that is an essential component for the cuticle synthesis. Once the cuticle is achieved, DOPA reaches high amounts in insects, which triggers endosymbiont elimination. This elimination relies on apoptosis and autophagy activation, allowing digestion and recycling of the endosymbiont material. Thus, the weevil-endosymbiont association reveals an adaptive interplay between metabolic and cellular functions that minimizes the cost of symbiosis and speeds up the exoskeleton formation during a critical phase when emerging adults are especially vulnerable.}, }
@article {pmid25238067, year = {2014}, author = {Birdsell, DN and Vogler, AJ and Buchhagen, J and Clare, A and Kaufman, E and Naumann, A and Driebe, E and Wagner, DM and Keim, PS}, title = {TaqMan real-time PCR assays for single-nucleotide polymorphisms which identify Francisella tularensis and its subspecies and subpopulations.}, journal = {PloS one}, volume = {9}, number = {9}, pages = {e107964}, pmid = {25238067}, issn = {1932-6203}, mesh = {DNA, Bacterial/chemistry ; Francisella tularensis/classification/*genetics/isolation &amp; purification ; Genotype ; Genotyping Techniques ; Humans ; *Polymorphism, Single Nucleotide ; Real-Time Polymerase Chain Reaction/methods ; Tularemia/diagnosis ; }, abstract = {Francisella tularensis, the etiologic agent of tularemia and a Class A Select Agent, is divided into three subspecies and multiple subpopulations that differ in virulence and geographic distribution. Given these differences, there is a need to rapidly and accurately determine if a strain is F. tularensis and, if it is, assign it to subspecies and subpopulation. We designed TaqMan real-time PCR genotyping assays using eleven single nucleotide polymorphisms (SNPs) that were potentially specific to closely related groups within the genus Francisella, including numerous subpopulations within F. tularensis species. We performed extensive validation studies to test the specificity of these SNPs to particular populations by screening the assays across a set of 565 genetically and geographically diverse F. tularensis isolates and an additional 21 genetic near-neighbor (outgroup) isolates. All eleven assays correctly determined the genetic groups of all 565 F. tularensis isolates. One assay differentiates F. tularensis, F. novicida, and F. hispaniensis from the more genetically distant F. philomiragia and Francisella-like endosymbionts. Another assay differentiates F. tularensis isolates from near neighbors. The remaining nine assays classify F. tularensis-confirmed isolates into F. tularensis subspecies and subpopulations. The genotyping accuracy of these nine assays diminished when tested on outgroup isolates (i.e. non F. tularensis), therefore a hierarchical approach of assay usage is recommended wherein the F. tularensis-specific assay is used before the nine downstream assays. Among F. tularensis isolates, all eleven assays were highly sensitive, consistently amplifying very low concentrations of DNA. Altogether, these eleven TaqMan real-time PCR assays represent a highly accurate, rapid, and sensitive means of identifying the species, subspecies, and subpopulation of any F. tularensis isolate if used in a step-wise hierarchical scheme. These assays would be very useful in clinical, epidemiological, and/or forensic investigations involving F. tularensis.}, }
@article {pmid25230723, year = {2014}, author = {Badawi, M and Giraud, I and Vavre, F and Grève, P and Cordaux, R}, title = {Signs of neutralization in a redundant gene involved in homologous recombination in Wolbachia endosymbionts.}, journal = {Genome biology and evolution}, volume = {6}, number = {10}, pages = {2654-2664}, pmid = {25230723}, issn = {1759-6653}, mesh = {Evolution, Molecular ; Genome, Bacterial/*genetics ; Phylogeny ; Symbiosis/genetics/physiology ; Wolbachia/*genetics ; }, abstract = {Genomic reduction in bacterial endosymbionts occurs through large genomic deletions and long-term accumulation of mutations. The latter process involves successive steps including gene neutralization, pseudogenization, and gradual erosion until complete loss. Although many examples of pseudogenes at various levels of degradation have been reported, neutralization cases are scarce because of the transient nature of the process. Gene neutralization may occur due to relaxation of selection in nonessential genes, for example, those involved in redundant functions. Here, we report an example of gene neutralization in the homologous recombination (HR) pathway of Wolbachia, a bacterial endosymbiont of arthropods and nematodes. The HR pathway is often depleted in endosymbiont genomes, but it is apparently intact in some Wolbachia strains. Analysis of 12 major HR genes showed that they have been globally under strong purifying selection during the evolution of Wolbachia strains hosted by arthropods, supporting the evolutionary importance of the HR pathway for these Wolbachia genomes. However, we detected signs of recent neutralization of the ruvA gene in a subset of Wolbachia strains, which might be related to an ancestral, clade-specific amino acid change that impaired DNA-binding activity. Strikingly, RuvA is part of the RuvAB complex involved in branch migration, whose function overlaps with the RecG helicase. Although ruvA is experiencing neutralization, recG is under strong purifying selection. Thus, our high phylogenetic resolution suggests that we identified a rare example of targeted neutralization of a gene involved in a redundant function in an endosymbiont genome.}, }
@article {pmid25226350, year = {2014}, author = {Sivaguru, M and Fried, GA and Miller, CA and Fouke, BW}, title = {Multimodal optical microscopy methods reveal polyp tissue morphology and structure in Caribbean reef building corals.}, journal = {Journal of visualized experiments : JoVE}, volume = {}, number = {91}, pages = {e51824}, pmid = {25226350}, issn = {1940-087X}, mesh = {Animals ; Anthozoa/*ultrastructure ; Caribbean Region ; *Coral Reefs ; Microscopy, Confocal/*methods ; Microscopy, Fluorescence/*methods ; }, abstract = {An integrated suite of imaging techniques has been applied to determine the three-dimensional (3D) morphology and cellular structure of polyp tissues comprising the Caribbean reef building corals Montastraeaannularis and M. faveolata. These approaches include fluorescence microscopy (FM), serial block face imaging (SBFI), and two-photon confocal laser scanning microscopy (TPLSM). SBFI provides deep tissue imaging after physical sectioning; it details the tissue surface texture and 3D visualization to tissue depths of more than 2 mm. Complementary FM and TPLSM yield ultra-high resolution images of tissue cellular structure. Results have: (1) identified previously unreported lobate tissue morphologies on the outer wall of individual coral polyps and (2) created the first surface maps of the 3D distribution and tissue density of chromatophores and algae-like dinoflagellate zooxanthellae endosymbionts. Spectral absorption peaks of 500 nm and 675 nm, respectively, suggest that M. annularis and M. faveolata contain similar types of chlorophyll and chromatophores. However, M. annularis and M. faveolata exhibit significant differences in the tissue density and 3D distribution of these key cellular components. This study focusing on imaging methods indicates that SBFI is extremely useful for analysis of large mm-scale samples of decalcified coral tissues. Complimentary FM and TPLSM reveal subtle submillimeter scale changes in cellular distribution and density in nondecalcified coral tissue samples. The TPLSM technique affords: (1) minimally invasive sample preparation, (2) superior optical sectioning ability, and (3) minimal light absorption and scattering, while still permitting deep tissue imaging.}, }
@article {pmid25224730, year = {2015}, author = {Zhang, YK and Ding, XL and Rong, X and Hong, XY}, title = {How do hosts react to endosymbionts? A new insight into the molecular mechanisms underlying the Wolbachia-host association.}, journal = {Insect molecular biology}, volume = {24}, number = {1}, pages = {1-12}, doi = {10.1111/imb.12128}, pmid = {25224730}, issn = {1365-2583}, mesh = {Animals ; Cytoplasm/physiology ; Female ; Gene Expression Profiling ; Male ; Oxidation-Reduction ; Phenotype ; Real-Time Polymerase Chain Reaction ; Reproduction/genetics ; Symbiosis/genetics ; Tetranychidae/*genetics/immunology/*microbiology ; Transcriptome ; Wolbachia/*physiology ; }, abstract = {Wolbachia is an intracellular bacterium that has aroused intense interest because of its ability to alter the biology of its host in diverse ways. In the two-spotted spider mite, Tetranychus urticae, Wolbachia can induce complex cytoplasmic incompatibility (CI) phenotypes and fitness changes, although little is known about the mechanisms. In the present study, we selected a strain of T. urticae, in which Wolbachia infection was associated with strong CI and enhanced female fecundity, to investigate changes in the transcriptome of T. urticae in Wolbachia-infected vs. uninfected lines. The responses were found to be sex-specific, with the transcription of 251 genes being affected in females and 171 genes being affected in males. Some of the more profoundly affected genes in both sexes were lipocalin genes and genes involved in oxidation reduction, digestion and detoxification. Several of the differentially expressed genes have potential roles in reproduction. Interestingly, unlike certain Wolbachia transinfections in novel hosts, the Wolbachia-host association in the present study showed no clear evidence of host immune priming by Wolbachia, although a few potential immune genes were affected.}, }
@article {pmid25217020, year = {2014}, author = {Hendry, TA and Hunter, MS and Baltrus, DA}, title = {The Facultative Symbiont Rickettsia Protects an Invasive Whitefly against Entomopathogenic Pseudomonas syringae Strains.}, journal = {Applied and environmental microbiology}, volume = {80}, number = {23}, pages = {7161-7168}, pmid = {25217020}, issn = {1098-5336}, mesh = {Animals ; *Antibiosis ; Hemiptera/*microbiology ; Pseudomonas syringae/*growth &amp; development ; Rickettsia/growth &amp; development/*physiology ; Survival Analysis ; *Symbiosis ; }, abstract = {Facultative endosymbionts can benefit insect hosts in a variety of ways, including context-dependent roles, such as providing defense against pathogens. The role of some symbionts in defense may be overlooked, however, when pathogen infection is transient, sporadic, or asymptomatic. The facultative endosymbiont Rickettsia increases the fitness of the sweet potato whitefly (Bemisia tabaci) in some populations through mechanisms that are not yet understood. In this study, we investigated the role of Rickettsia in mediating the interaction between the sweet potato whitefly and Pseudomonas syringae, a common environmental bacterium, some strains of which are pathogenic to aphids. Our results show that P. syringae multiplies within whiteflies, leading to host death, and that whiteflies infected with Rickettsia show a decreased rate of death due to P. syringae. Experiments using plants coated with P. syringae confirmed that whiteflies can acquire the bacteria at a low rate while feeding, leading to increased mortality, particularly when the whiteflies are not infected with Rickettsia. These results suggest that P. syringae may affect whitefly populations in nature and that Rickettsia can ameliorate this effect. This study highlights the possible importance of interactions among opportunistic environmental pathogens and endosymbionts of insects.}, }
@article {pmid25213693, year = {2014}, author = {Boyd, BM and Allen, JM and de Crécy-Lagard, V and Reed, DL}, title = {Genome sequence of Candidatus Riesia pediculischaeffi, endosymbiont of chimpanzee lice, and genomic comparison of recently acquired endosymbionts from human and chimpanzee lice.}, journal = {G3 (Bethesda, Md.)}, volume = {4}, number = {11}, pages = {2189-2195}, pmid = {25213693}, issn = {2160-1836}, support = {R01 GM070641/GM/NIGMS NIH HHS/United States ; R01 GM70641/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Enterobacteriaceae/*genetics/pathogenicity ; *Evolution, Molecular ; Gene Deletion ; *Genome, Bacterial ; Heat-Shock Proteins/genetics ; Humans ; Pan troglodytes/parasitology ; Pantothenic Acid/biosynthesis/genetics ; Phthiraptera/microbiology/pathogenicity ; Symbiosis/*genetics ; Thiamine/biosynthesis/genetics ; }, abstract = {The obligate-heritable endosymbionts of insects possess some of the smallest known bacterial genomes. This is likely due to loss of genomic material during symbiosis. The mode and rate of this erosion may change over evolutionary time: faster in newly formed associations and slower in long-established ones. The endosymbionts of human and anthropoid primate lice present a unique opportunity to study genome erosion in newly established (or young) symbionts. This is because we have a detailed phylogenetic history of these endosymbionts with divergence dates for closely related species. This allows for genome evolution to be studied in detail and rates of change to be estimated in a phylogenetic framework. Here, we sequenced the genome of the chimpanzee louse endosymbiont (Candidatus Riesia pediculischaeffi) and compared it with the closely related genome of the human body louse endosymbiont. From this comparison, we found evidence for recent genome erosion leading to gene loss in these endosymbionts. Although gene loss was detected, it was not significantly greater than in older endosymbionts from aphids and ants. Additionally, we searched for genes associated with B-vitamin synthesis in the two louse endosymbiont genomes because these endosymbionts are believed to synthesize essential B vitamins absent in the louse's diet. All of the expected genes were present, except those involved in thiamin synthesis. We failed to find genes encoding for proteins involved in the biosynthesis of thiamin or any complete exogenous means of salvaging thiamin, suggesting there is an undescribed mechanism for the salvage of thiamin. Finally, genes encoding for the pantothenate de novo biosynthesis pathway were located on a plasmid in both taxa along with a heat shock protein. Movement of these genes onto a plasmid may be functionally and evolutionarily significant, potentially increasing production and guarding against the deleterious effects of mutation. These data add to a growing resource of obligate endosymbiont genomes and to our understanding of the rate and mode of genome erosion in obligate animal-associated bacteria. Ultimately sequencing additional louse p-endosymbiont genomes will provide a model system for studying genome evolution in obligate host associated bacteria.}, }
@article {pmid25212515, year = {2015}, author = {da Fonseca Barbosa, L and Yuki, VA and Marubayashi, JM and De Marchi, BR and Perini, FL and Pavan, MA and de Barros, DR and Ghanim, M and Moriones, E and Navas-Castillo, J and Krause-Sakate, R}, title = {First report of Bemisia tabaci Mediterranean (Q biotype) species in Brazil.}, journal = {Pest management science}, volume = {71}, number = {4}, pages = {501-504}, doi = {10.1002/ps.3909}, pmid = {25212515}, issn = {1526-4998}, mesh = {*Animal Distribution ; Animals ; Bacteroidetes/classification/isolation &amp; purification ; Brazil ; Electron Transport Complex IV/genetics/metabolism ; Enterobacteriaceae/classification/isolation &amp; purification ; Hemiptera/classification/genetics/microbiology/*physiology ; *Insect Control ; Insect Proteins/genetics/metabolism ; Mitochondrial Proteins/genetics/metabolism ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci is a major cosmopolitan pest and comprises a complex of more than 36 cryptic species that cause serious damage to agricultural crops worldwide. In this study, the Mediterranean species of B. tabaci, formerly known as Q biotype, was identified for the first time in Brazil.<br><br>RESULTS: Adult B. tabaci were collected from different localities and hosts from Rio Grande do Sul, the southernmost state of the country that borders Uruguay and Argentina. Partial sequencing of the mitochondrial cytochrome oxidase I (mtCOI) gene indicated that B. tabaci MED species appears to be restricted to the province of Barra do Quara&#xed;, infesting Capsicum annuum cultivated in greenhouses and Ipomoea batatas in open fields. The partial mtCOI sequences obtained shared 100% nucleotide identity with reference sequences for the Q biotype reported from Uruguay. The secondary endosymbionts Hamiltonella and Cardinium were detected by PCR in the new identified MED species from Brazil, similarly to the Q biotype from Uruguay.<br><br>CONCLUSION: Our results indicate the presence of the MED species in Brazil. The close monitoring of this new identified species in the southern region of Brazil is essential to avoid its geographical expansion to more important agricultural areas in the country.}, }
@article {pmid25206351, year = {2014}, author = {López-Madrigal, S and Beltrà, A and Resurrección, S and Soto, A and Latorre, A and Moya, A and Gil, R}, title = {Molecular evidence for ongoing complementarity and horizontal gene transfer in endosymbiotic systems of mealybugs.}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {449}, pmid = {25206351}, issn = {1664-302X}, abstract = {Intracellular bacterial supply of essential amino acids is common among sap-feeding insects, thus complementing the scarcity of nitrogenous compounds in plant phloem. This is also the role of the two mealybug endosymbiotic systems whose genomes have been sequenced. In the nested endosymbiotic system from Planococcus citri (Pseudococcinae), "Candidatus Tremblaya princeps" and "Candidatus Moranella endobia" cooperate to synthesize essential amino acids, while in Phenacoccus avenae (Phenacoccinae) this function is performed by its single endosymbiont "Candidatus Tremblaya phenacola." However, little is known regarding the evolution of essential amino acid supplementation strategies in other mealybug systems. To address this knowledge gap, we screened for the presence of six selected loci involved in essential amino acid biosynthesis in five additional mealybug species. We found evidence of ongoing complementarity among endosymbionts from insects of subfamily Pseudococcinae, as well as horizontal gene transfer affecting endosymbionts from insects of family Phenacoccinae, providing a more comprehensive picture of the evolutionary history of these endosymbiotic systems. Additionally, we report two diagnostic motifs to help identify invasive mealybug species.}, }
@article {pmid25203785, year = {2014}, author = {do Rosário Gomes, H and Goes, JI and Matondkar, SG and Buskey, EJ and Basu, S and Parab, S and Thoppil, P}, title = {Massive outbreaks of Noctiluca scintillans blooms in the Arabian Sea due to spread of hypoxia.}, journal = {Nature communications}, volume = {5}, number = {}, pages = {4862}, doi = {10.1038/ncomms5862}, pmid = {25203785}, issn = {2041-1723}, mesh = {Chlorophyta/physiology ; Dinoflagellida/growth &amp; development/*physiology ; *Oceans and Seas ; Oxygen/*chemistry ; Photosynthesis/physiology ; *Seasons ; Seawater/*chemistry/parasitology ; Symbiosis/physiology ; }, abstract = {In the last decade, the northern Arabian Sea has witnessed a radical shift in the composition of winter phytoplankton blooms, which previously comprised mainly of diatoms, the unicellular, siliceous photosynthetic organisms favoured by nutrient-enriched waters from convective mixing. These trophically important diatom blooms have been replaced by widespread blooms of a large, green dinoflagellate, Noctiluca scintillans, which combines carbon fixation from its chlorophyll-containing endosymbiont with ingestion of prey. Here, we report that these massive outbreaks of N. scintillans during winter are being facilitated by an unprecedented influx of oxygen deficient waters into the euphotic zone and by the extraordinary ability of its endosymbiont Pedinomonas noctilucae to fix carbon more efficiently than other phytoplankton under hypoxic conditions. We contend that N. scintillans blooms could disrupt the traditional diatom-sustained food chain to the detriment of regional fisheries and long-term health of an ecosystem supporting a coastal population of nearly 120 million people.}, }
@article {pmid25203210, year = {2014}, author = {Kim, DH and Park, MJ and Gwon, GH and Silkov, A and Xu, ZY and Yang, EC and Song, S and Song, K and Kim, Y and Yoon, HS and Honig, B and Cho, W and Cho, Y and Hwang, I}, title = {An ankyrin repeat domain of AKR2 drives chloroplast targeting through coincident binding of two chloroplast lipids.}, journal = {Developmental cell}, volume = {30}, number = {5}, pages = {598-609}, pmid = {25203210}, issn = {1878-1551}, support = {R01 GM068849/GM/NIGMS NIH HHS/United States ; R01 GM030518/GM/NIGMS NIH HHS/United States ; R01 GM110128/GM/NIGMS NIH HHS/United States ; GM68849/GM/NIGMS NIH HHS/United States ; U54 GM094597/GM/NIGMS NIH HHS/United States ; R37 GM030518/GM/NIGMS NIH HHS/United States ; GM30518/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; *Ankyrin Repeat ; Arabidopsis/*metabolism ; Arabidopsis Proteins/*chemistry/metabolism/physiology ; Binding Sites ; Chloroplasts/*metabolism ; Cyanobacteria/metabolism ; Cytosol/metabolism ; Galactolipids/chemistry ; Lipids/*chemistry ; Models, Molecular ; Molecular Chaperones/*chemistry/physiology ; Molecular Sequence Data ; Phosphatidylglycerols/chemistry ; Protein Binding ; Protein Structure, Tertiary ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {In organellogenesis of the chloroplast from endosymbiotic cyanobacteria, the establishment of protein-targeting mechanisms to the chloroplast should have been pivotal. However, it is still mysterious how these mechanisms were established and how they work in plant cells. Here we show that AKR2A, the cytosolic targeting factor for chloroplast outer membrane (COM) proteins, evolved from the ankyrin repeat domain (ARD) of the host cell by stepwise extensions of its N-terminal domain and that two lipids, monogalactosyldiacylglycerol (MGDG) and phosphatidylglycerol (PG), of the endosymbiont were selected to function as the AKR2A receptor. Structural analysis, molecular modeling, and mutational analysis of the ARD identified two adjacent sites for coincidental and synergistic binding of MGDG and PG. Based on these findings, we propose that the targeting mechanism of COM proteins was established using components from both the endosymbiont and host cell through a modification of the protein-protein-interacting ARD into a lipid binding domain.}, }
@article {pmid25196985, year = {2014}, author = {Santos-Garcia, D and Silva, FJ and Moya, A and Latorre, A}, title = {No exception to the rule: Candidatus Portiera aleyrodidarum cell wall revisited.}, journal = {FEMS microbiology letters}, volume = {360}, number = {2}, pages = {132-136}, doi = {10.1111/1574-6968.12595}, pmid = {25196985}, issn = {1574-6968}, mesh = {Animals ; Cell Wall/genetics/*ultrastructure ; Genes, Bacterial ; Halomonadaceae/genetics/isolation &amp; purification/*ultrastructure ; Hemiptera/*microbiology ; Microscopy, Electron, Transmission ; }, abstract = {Many insect endosymbionts described so far are gram-negative bacteria. Primary endosymbionts are obligatory bacteria usually harboured by insects inside vacuoles in specialized cells called bacteriocytes. This combination produces a typical three-membrane system with one membrane derived from the insect vacuole and the other two from the bacterial gram-negative cell envelope, composed by the cell wall (the outer membrane plus the periplasmic space) and the plasma membrane (the inner membrane). For the last 21 years, the primary endosymbiont of whiteflies 'Candidatus Portiera aleyrodidarum' was considered an exception to this rule. Previous works stated that only two membranes were present, the vacuolar membrane and one of the two bacterial membranes. The absence of the cell wall was related to the special vertical transmission of the endosymbionts in whiteflies. In this work, we present electron microscopic studies showing a complete cell envelope in 'Ca. Portiera aleyrodidarum' from the whitefly Bemisia tabaci. Additionally, comparison of the inferred metabolism from the gene content did not show any difference in cell envelope biogenesis compared with the closely related three-membrane endosymbionts 'Candidatus Carsonella ruddii' and 'Candidatus Evansia muelleri' Xc1. Our results rule out the proposal that 'Ca. Portiera aleyrodidarum' is an exception to the three-membrane system.}, }
@article {pmid25183343, year = {2015}, author = {Lin, XL and Kang, ZW and Pan, QJ and Liu, TX}, title = {Evaluation of five antibiotics on larval gut bacterial diversity of Plutella xylostella (Lepidoptera: Plutellidae).}, journal = {Insect science}, volume = {22}, number = {5}, pages = {619-628}, doi = {10.1111/1744-7917.12168}, pmid = {25183343}, issn = {1744-7917}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Bacteria/*drug effects/isolation &amp; purification ; Biodiversity ; Brassica ; Denaturing Gradient Gel Electrophoresis ; Diet ; Gastrointestinal Tract/microbiology ; Larva/drug effects/growth &amp; development/microbiology ; Moths/*drug effects/growth &amp; development/microbiology ; }, abstract = {Larvae of the diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), have rich microbial communities inhabiting the gut, and these bacteria contribute to the fitness of the pest. In this study we evaluated the effects of five antibiotics (rifampicin, ampicillin, tetracycline, streptomycin sulfate and chloramphenicol) on the gut bacterial diversity of P. xylostella larvae. We screened five different concentrations for each antibiotic in a leaf disc assay, and found that rifampicin and streptomycin sulfate at 3 mg/mL significantly reduced the diversity of the bacterial community, and some bacterial species could be rapidly eliminated. The number of gut bacteria in the rifampicin group and streptomycin sulfate group decreased more rapidly than the others. With the increase of antibiotic concentration, the removal efficiency was improved, whereas toxic effects became more apparent. All antibiotics reduced larval growth and development, and eventually caused high mortality, malformation of the prepupae, and hindered pupation and adult emergence. Among the five antibiotics, tetracycline was the most toxic and streptomycin sulfate was a relatively mild one. Some dominant bacteria were not affected by feeding antibiotics alone. Denaturing gradient gel electrophoresis graph showed that the most abundant and diverse bacteria in P. xylostella larval gut appeared in the cabbage feeding group, and diet change and antibiotics intake influenced gut flora abundance. Species diversity was significantly reduced in the artificial diet and antibiotics treatment groups. After feeding on the artificial diet with rifampicin, streptomycin sulfate and their mixture for 10 days, larval gut bacteria could not be completely removed as detected with the agarose gel electrophoresis method.}, }
@article {pmid25182414, year = {2014}, author = {Moebius, N and Üzüm, Z and Dijksterhuis, J and Lackner, G and Hertweck, C}, title = {Active invasion of bacteria into living fungal cells.}, journal = {eLife}, volume = {3}, number = {}, pages = {e03007}, pmid = {25182414}, issn = {2050-084X}, mesh = {Burkholderia/genetics/*metabolism/ultrastructure ; Chitinases/metabolism ; Cryoelectron Microscopy ; Electrophoresis, Gel, Two-Dimensional ; Host-Pathogen Interactions ; Hyphae/genetics/metabolism/ultrastructure ; Macrolides/*metabolism ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Mutation ; Oryza/microbiology ; Plant Diseases/microbiology ; Proteome/metabolism ; Proteomics/methods ; Rhizopus/genetics/*metabolism/ultrastructure ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; *Symbiosis ; }, abstract = {The rice seedling blight fungus Rhizopus microsporus and its endosymbiont Burkholderia rhizoxinica form an unusual, highly specific alliance to produce the highly potent antimitotic phytotoxin rhizoxin. Yet, it has remained a riddle how bacteria invade the fungal cells. Genome mining for potential symbiosis factors and functional analyses revealed that a type 2 secretion system (T2SS) of the bacterial endosymbiont is required for the formation of the endosymbiosis. Comparative proteome analyses show that the T2SS releases chitinolytic enzymes (chitinase, chitosanase) and chitin-binding proteins. The genes responsible for chitinolytic proteins and T2SS components are highly expressed during infection. Through targeted gene knock-outs, sporulation assays and microscopic investigations we found that chitinase is essential for bacteria to enter hyphae. Unprecedented snapshots of the traceless bacterial intrusion were obtained using cryo-electron microscopy. Beyond unveiling the pivotal role of chitinolytic enzymes in the active invasion of a fungus by bacteria, these findings grant unprecedented insight into the fungal cell wall penetration and symbiosis formation.}, }
@article {pmid25181949, year = {2014}, author = {Colebunders, R and Hendy, A and Nanyunja, M and Wamala, JF and van Oijen, M}, title = {Nodding syndrome-a new hypothesis and new direction for research.}, journal = {International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases}, volume = {27}, number = {}, pages = {74-77}, doi = {10.1016/j.ijid.2014.08.001}, pmid = {25181949}, issn = {1878-3511}, support = {001/WHO_/World Health Organization/International ; }, mesh = {Adolescent ; Animals ; Child ; Child, Preschool ; Epilepsy/*epidemiology/parasitology ; Humans ; Microfilariae/isolation &amp; purification ; Nodding Syndrome/*epidemiology/etiology/parasitology ; Onchocerciasis/*epidemiology/parasitology ; Prevalence ; Simuliidae/parasitology ; Sudan/epidemiology ; Tanzania/epidemiology ; Uganda/epidemiology ; }, abstract = {Nodding syndrome (NS) is an unexplained neurological illness that mainly affects children aged between 5 and 15 years. NS has so far been reported from South Sudan, northern Uganda, and Tanzania, but in spite of extensive investigations, the aetiology remains unknown. We hypothesize that blackflies (Diptera: Simuliidae) infected with Onchocerca volvulus microfilariae may also transmit another pathogen. This may be a novel neurotropic virus or an endosymbiont of the microfilariae, which causes not only NS, but also epilepsy without nodding. This hypothesis addresses many of the questions about NS that researchers have previously been unable to answer. An argument in favour of the hypothesis is the fact that in Uganda, the number of new NS cases decreased (with no new cases reported since 2013) after ivermectin coverage was increased and with the implementation of a programme of aerial spraying and larviciding of the large rivers where blackflies were breeding. If confirmed, our hypothesis will enable new strategies to control NS outbreaks.}, }
@article {pmid25181317, year = {2014}, author = {Remigi, P and Capela, D and Clerissi, C and Tasse, L and Torchet, R and Bouchez, O and Batut, J and Cruveiller, S and Rocha, EP and Masson-Boivin, C}, title = {Transient hypermutagenesis accelerates the evolution of legume endosymbionts following horizontal gene transfer.}, journal = {PLoS biology}, volume = {12}, number = {9}, pages = {e1001942}, pmid = {25181317}, issn = {1545-7885}, mesh = {ATP-Binding Cassette Transporters/genetics ; Adaptation, Physiological/genetics ; Biological Evolution ; Cupriavidus/*genetics ; Fabaceae/microbiology/physiology ; *Gene Transfer, Horizontal ; *Genes, Bacterial ; *Genome, Bacterial ; Mimosa/microbiology/physiology ; Mutation ; Plasmids/*metabolism ; Ralstonia solanacearum/*genetics ; Symbiosis/genetics ; }, abstract = {Horizontal gene transfer (HGT) is an important mode of adaptation and diversification of prokaryotes and eukaryotes and a major event underlying the emergence of bacterial pathogens and mutualists. Yet it remains unclear how complex phenotypic traits such as the ability to fix nitrogen with legumes have successfully spread over large phylogenetic distances. Here we show, using experimental evolution coupled with whole genome sequencing, that co-transfer of imuABC error-prone DNA polymerase genes with key symbiotic genes accelerates the evolution of a soil bacterium into a legume symbiont. Following introduction of the symbiotic plasmid of Cupriavidus taiwanensis, the Mimosa symbiont, into pathogenic Ralstonia solanacearum we challenged transconjugants to become Mimosa symbionts through serial plant-bacteria co-cultures. We demonstrate that a mutagenesis imuABC cassette encoded on the C. taiwanensis symbiotic plasmid triggered a transient hypermutability stage in R. solanacearum transconjugants that occurred before the cells entered the plant. The generated burst in genetic diversity accelerated symbiotic adaptation of the recipient genome under plant selection pressure, presumably by improving the exploration of the fitness landscape. Finally, we show that plasmid imuABC cassettes are over-represented in rhizobial lineages harboring symbiotic plasmids. Our findings shed light on a mechanism that may have facilitated the dissemination of symbiotic competency among α- and β-proteobacteria in natura and provide evidence for the positive role of environment-induced mutagenesis in the acquisition of a complex lifestyle trait. We speculate that co-transfer of complex phenotypic traits with mutagenesis determinants might frequently enhance the ecological success of HGT.}, }
@article {pmid25179144, year = {2014}, author = {Penny, D and Collins, LJ and Daly, TK and Cox, SJ}, title = {The relative ages of eukaryotes and akaryotes.}, journal = {Journal of molecular evolution}, volume = {79}, number = {5-6}, pages = {228-239}, pmid = {25179144}, issn = {1432-1432}, mesh = {Archaea/*chemistry/classification/cytology ; *Biological Evolution ; Cell Nucleus/genetics/metabolism ; Eukaryotic Cells/*chemistry/classification/metabolism ; Exons ; Introns ; Meiosis ; Mitochondria/chemistry/metabolism ; Mitosis ; *Origin of Life ; Phylogeny ; Prokaryotic Cells/*chemistry/classification/metabolism ; Spliceosomes/genetics ; Terminology as Topic ; Time Factors ; }, abstract = {The Last Eukaryote Common Ancestor (LECA) appears to have the genetics required for meiosis, mitosis, nucleus and nuclear substructures, an exon/intron gene structure, spliceosomes, many centres of DNA replication, etc. (and including mitochondria). Most of these features are not generally explained by models for the origin of the Eukaryotic cell based on the fusion of an Archeon and a Bacterium. We find that the term 'prokaryote' is ambiguous and the non-phylogenetic term akaryote should be used in its place because we do not yet know the direction of evolution between eukaryotes and akaryotes. We use the term 'protoeukaryote' for the hypothetical stem group ancestral eukaryote that took up a bacterium as an endosymbiont that formed the mitochondrion. It is easier to make detailed models with a eukaryote to an akaryote transition, rather than vice versa. So we really are at a phylogenetic impasse in not being confident about the direction of change between eukaryotes and akaryotes.}, }
@article {pmid25175626, year = {2014}, author = {Van Leuven, JT and Meister, RC and Simon, C and McCutcheon, JP}, title = {Sympatric speciation in a bacterial endosymbiont results in two genomes with the functionality of one.}, journal = {Cell}, volume = {158}, number = {6}, pages = {1270-1280}, doi = {10.1016/j.cell.2014.07.047}, pmid = {25175626}, issn = {1097-4172}, support = {P20RR017670/RR/NCRR NIH HHS/United States ; }, mesh = {Alphaproteobacteria/*classification/*genetics/isolation &amp; purification/physiology ; Animals ; Evolution, Molecular ; *Genome, Bacterial ; Hemiptera/cytology/*microbiology/physiology ; Molecular Sequence Data ; Pseudogenes ; Symbiosis ; }, abstract = {Mutualisms that become evolutionarily stable give rise to organismal interdependencies. Some insects have developed intracellular associations with communities of bacteria, where the interdependencies are manifest in patterns of complementary gene loss and retention among members of the symbiosis. Here, using comparative genomics and microscopy, we show that a three-member symbiotic community has become a four-way assemblage through a novel bacterial lineage-splitting event. In some but not all cicada species of the genus Tettigades, the endosymbiont Candidatus Hodgkinia cicadicola has split into two new cytologically distinct but metabolically interdependent species. Although these new bacterial genomes are partitioned into discrete cell types, the intergenome patterns of gene loss and retention are almost perfectly complementary. These results defy easy classification: they show genomic patterns consistent with those observed after both speciation and whole-genome duplication. We suggest that our results highlight the potential power of nonadaptive forces in shaping organismal complexity.}, }
@article {pmid25172904, year = {2014}, author = {Hehenberger, E and Imanian, B and Burki, F and Keeling, PJ}, title = {Evidence for the retention of two evolutionary distinct plastids in dinoflagellates with diatom endosymbionts.}, journal = {Genome biology and evolution}, volume = {6}, number = {9}, pages = {2321-2334}, pmid = {25172904}, issn = {1759-6653}, mesh = {*Biological Evolution ; Diatoms/classification/*genetics/physiology ; Dinoflagellida/classification/*genetics/physiology ; Molecular Sequence Data ; Phylogeny ; Plastids/*genetics/physiology ; *Symbiosis ; }, abstract = {Dinoflagellates harboring diatom endosymbionts (termed "dinotoms") have undergone a process often referred to as "tertiary endosymbiosis"--the uptake of algae containing secondary plastids and integration of those plastids into the new host. In contrast to other tertiary plastids, and most secondary plastids, the endosymbiont of dinotoms is distinctly less reduced, retaining a number of cellular features, such as their nucleus and mitochondria and others, in addition to their plastid. This has resulted in redundancy between host and endosymbiont, at least between some mitochondrial and cytosolic metabolism, where this has been investigated. The question of plastidial redundancy is particularly interesting as the fate of the host dinoflagellate plastid is unclear. The host cytosol possesses an eyespot that has been postulated to be a remnant of the ancestral peridinin plastid, but this has not been tested, nor has its possible retention of plastid functions. To investigate this possibility, we searched for plastid-associated pathways and functions in transcriptomic data sets from three dinotom species. We show that the dinoflagellate host has indeed retained genes for plastid-associated pathways and that these genes encode targeting peptides similar to those of other dinoflagellate plastid-targeted proteins. Moreover, we also identified one gene encoding an essential component of the dinoflagellate plastid protein import machinery, altogether suggesting the presence of a functioning plastid import system in the host, and by extension a relict plastid. The presence of the same plastid-associated pathways in the endosymbiont also extends the known functional redundancy in dinotoms, further confirming the unusual state of plastid integration in this group of dinoflagellates.}, }
@article {pmid25169983, year = {2014}, author = {Ternes, CM and Schönknecht, G}, title = {Gene transfers shaped the evolution of de novo NAD+ biosynthesis in eukaryotes.}, journal = {Genome biology and evolution}, volume = {6}, number = {9}, pages = {2335-2349}, pmid = {25169983}, issn = {1759-6653}, mesh = {Animals ; Eukaryota/classification/genetics/*metabolism ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Humans ; Metabolic Networks and Pathways ; NAD/*biosynthesis ; Phylogeny ; }, abstract = {NAD(+) is an essential molecule for life, present in each living cell. It can function as an electron carrier or cofactor in redox biochemistry and energetics, and serves as substrate to generate the secondary messenger cyclic ADP ribose and nicotinic acid adenine dinucleotide phosphate. Although de novo NAD(+) biosynthesis is essential, different metabolic pathways exist in different eukaryotic clades. The kynurenine pathway starting with tryptophan was most likely present in the last common ancestor of all eukaryotes, and is active in fungi and animals. The aspartate pathway, detected in most photosynthetic eukaryotes, was probably acquired from the cyanobacterial endosymbiont that gave rise to chloroplasts. An evolutionary analysis of enzymes catalyzing de novo NAD(+) biosynthesis resulted in evolutionary trees incongruent with established organismal phylogeny, indicating numerous gene transfers. Endosymbiotic gene transfers probably introduced the aspartate pathway into eukaryotes and may have distributed it among different photosynthetic clades. In addition, several horizontal gene transfers substituted eukaryotic genes with bacterial orthologs. Although horizontal gene transfer is accepted as a key mechanism in prokaryotic evolution, it is supposed to be rare in eukaryotic evolution. The essential metabolic pathway of de novo NAD(+) biosynthesis in eukaryotes was shaped by numerous gene transfers.}, }
@article {pmid25168586, year = {2014}, author = {Ioannidis, P and Lu, Y and Kumar, N and Creasy, T and Daugherty, S and Chibucos, MC and Orvis, J and Shetty, A and Ott, S and Flowers, M and Sengamalay, N and Tallon, LJ and Pick, L and Dunning Hotopp, JC}, title = {Rapid transcriptome sequencing of an invasive pest, the brown marmorated stink bug Halyomorpha halys.}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {738}, pmid = {25168586}, issn = {1471-2164}, mesh = {Animals ; Bacteria/genetics ; Bacterial Proteins/genetics ; Computational Biology/methods ; Female ; Gene Expression Profiling/*methods ; Gene Transfer, Horizontal ; Heteroptera/*genetics/microbiology ; Insect Proteins/*genetics ; Introduced Species ; Male ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, RNA/*methods ; Symbiosis ; }, abstract = {BACKGROUND: Halyomorpha halys (Stål) (Insecta:Hemiptera;Pentatomidae), commonly known as the Brown Marmorated Stink Bug (BMSB), is an invasive pest of the mid-Atlantic region of the United States, causing economically important damage to a wide range of crops. Native to Asia, BMSB was first observed in Allentown, PA, USA, in 1996, and this pest is now well-established throughout the US mid-Atlantic region and beyond. In addition to the serious threat BMSB poses to agriculture, BMSB has become a nuisance to homeowners, invading home gardens and congregating in large numbers in human-made structures, including homes, to overwinter. Despite its significance as an agricultural pest with limited control options, only 100 bp of BMSB sequence data was available in public databases when this project began.<br><br>RESULTS: Transcriptome sequencing was undertaken to provide a molecular resource to the research community to inform the development of pest control strategies and to provide molecular data for population genetics studies of BMSB. Using normalized, strand-specific libraries, we sequenced pools of all BMSB life stages on the Illumina HiSeq. Trinity was used to assemble 200,000 putative transcripts in >100,000 components. A novel bioinformatic method that analyzed the strand-specificity of the data reduced this to 53,071 putative transcripts from 18,573 components. By integrating multiple other data types, we narrowed this further to 13,211 representative transcripts.<br><br>CONCLUSIONS: Bacterial endosymbiont genes were identified in this dataset, some of which have a copy number consistent with being lateral gene transfers between endosymbiont genomes and Hemiptera, including ankyrin-repeat related proteins, lysozyme, and mannanase. Such genes and endosymbionts may provide novel targets for BMSB-specific biocontrol. This study demonstrates the utility of strand-specific sequencing in generating shotgun transcriptomes and that rapid sequencing shotgun transcriptomes is possible without the need for extensive inbreeding to generate homozygous lines. Such sequencing can provide a rapid response to pest invasions similar to that already described for disease epidemiology.}, }
@article {pmid25165813, year = {2014}, author = {Landmann, F and Foster, JM and Michalski, ML and Slatko, BE and Sullivan, W}, title = {Co-evolution between an endosymbiont and its nematode host: Wolbachia asymmetric posterior localization and AP polarity establishment.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {8}, pages = {e3096}, pmid = {25165813}, issn = {1935-2735}, mesh = {Animals ; *Biological Evolution ; Brugia malayi/genetics/*microbiology/physiology ; Cell Polarity/*physiology ; Centrosome/physiology ; Dyneins/physiology ; Microtubule-Organizing Center/physiology ; Oocytes/physiology ; Symbiosis/*physiology ; Wolbachia/*physiology ; }, abstract = {While bacterial symbionts influence a variety of host cellular responses throughout development, there are no documented instances in which symbionts influence early embryogenesis. Here we demonstrate that Wolbachia, an obligate endosymbiont of the parasitic filarial nematodes, is required for proper anterior-posterior polarity establishment in the filarial nematode B. malayi. Characterization of pre- and post-fertilization events in B. malayi reveals that, unlike C. elegans, the centrosomes are maternally derived and produce a cortical-based microtubule organizing center prior to fertilization. We establish that Wolbachia rely on these cortical microtubules and dynein to concentrate at the posterior cortex. Wolbachia also rely on PAR-1 and PAR-3 polarity cues for normal concentration at the posterior cortex. Finally, we demonstrate that Wolbachia depletion results in distinct anterior-posterior polarity defects. These results provide a striking example of endosymbiont-host co-evolution operating on the core initial developmental event of axis determination.}, }
@article {pmid25165636, year = {2014}, author = {Metcalf, JA and Jo, M and Bordenstein, SR and Jaenike, J and Bordenstein, SR}, title = {Recent genome reduction of Wolbachia in Drosophila recens targets phage WO and narrows candidates for reproductive parasitism.}, journal = {PeerJ}, volume = {2}, number = {}, pages = {e529}, pmid = {25165636}, issn = {2167-8359}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; T32 GM007347/GM/NIGMS NIH HHS/United States ; }, abstract = {Wolbachia are maternally transmitted endosymbionts that often alter their arthropod hosts' biology to favor the success of infected females, and they may also serve as a speciation microbe driving reproductive isolation. Two of these host manipulations include killing males outright and reducing offspring survival when infected males mate with uninfected females, a phenomenon known as cytoplasmic incompatibility. Little is known about the mechanisms behind these phenotypes, but interestingly either effect can be caused by the same Wolbachia strain when infecting different hosts. For instance, wRec causes cytoplasmic incompatibility in its native host Drosophila recens and male killing in D. subquinaria. The discovery of prophage WO elements in most arthropod Wolbachia has generated the hypothesis that WO may encode genes involved in these reproductive manipulations. However, PCR screens for the WO minor capsid gene indicated that wRec lacks phage WO. Thus, wRec seemed to provide an example where phage WO is not needed for Wolbachia-induced reproductive manipulation. To enable investigation of the mechanism of phenotype switching in different host backgrounds, and to examine the unexpected absence of phage WO, we sequenced the genome of wRec. Analyses reveal that wRec diverged from wMel approximately 350,000 years ago, mainly by genome reduction in the phage regions. While it lost the minor capsid gene used in standard PCR screens for phage WO, it retained two regions encompassing 33 genes, several of which have previously been associated with reproductive parasitism. Thus, WO gene involvement in reproductive manipulation cannot be excluded and reliance on single gene PCR should not be used to rule out the presence of phage WO in Wolbachia. Additionally, the genome sequence for wRec will enable transcriptomic and proteomic studies that may help elucidate the Wolbachia mechanisms of altered reproductive manipulations associated with host switching, perhaps among the 33 remaining phage genes.}, }
@article {pmid25156506, year = {2014}, author = {Hamm, CA and Begun, DJ and Vo, A and Smith, CC and Saelao, P and Shaver, AO and Jaenike, J and Turelli, M}, title = {Wolbachia do not live by reproductive manipulation alone: infection polymorphism in Drosophila suzukii and D. subpulchrella.}, journal = {Molecular ecology}, volume = {23}, number = {19}, pages = {4871-4885}, pmid = {25156506}, issn = {1365-294X}, support = {R01 GM084056/GM/NIGMS NIH HHS/United States ; R01 GM104325/GM/NIGMS NIH HHS/United States ; R01GM084056/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacterial Typing Techniques ; DNA, Mitochondrial/genetics ; Drosophila/classification/*microbiology/physiology ; Female ; Fertility ; Male ; Multilocus Sequence Typing ; Phylogeny ; Reproduction ; Wolbachia/classification/*physiology ; }, abstract = {Drosophila suzukii recently invaded North America and Europe. Populations in Hawaii, California, New York and Nova Scotia are polymorphic for Wolbachia, typically with <20% infection frequency. The Wolbachia in D. suzukii, denoted wSuz, is closely related to wRi, the variant prevalent in continental populations of D. simulans. wSuz is also nearly identical to Wolbachia found in D. subpulchrella, plausibly D. suzukii's sister species. This suggests vertical Wolbachia transmission through cladogenesis ('cladogenic transmission'). The widespread occurrence of 7-20% infection frequencies indicates a stable polymorphism. wSuz is imperfectly maternally transmitted, with wild infected females producing on average 5-10% uninfected progeny. As expected from its low frequency, wSuz produces no cytoplasmic incompatibility (CI), that is, no increased embryo mortality when infected males mate with uninfected females, and no appreciable sex-ratio distortion. The persistence of wSuz despite imperfect maternal transmission suggests positive fitness effects. Assuming a balance between selection and imperfect transmission, we expect a fitness advantage on the order of 20%. Unexpectedly, Wolbachia-infected females produce fewer progeny than do uninfected females. We do not yet understand the maintenance of wSuz in D. suzukii. The absence of detectable CI in D. suzukii and D. subpulchrella makes it unlikely that CI-based mechanisms could be used to control this species without transinfection using novel Wolbachia. Contrary to their reputation as horizontally transmitted reproductive parasites, many Wolbachia infections are acquired through introgression or cladogenesis and many cause no appreciable reproductive manipulation. Such infections, likely to be mutualistic, may be central to understanding the pervasiveness of Wolbachia among arthropods.}, }
@article {pmid25156176, year = {2014}, author = {Lema, KA and Bourne, DG and Willis, BL}, title = {Onset and establishment of diazotrophs and other bacterial associates in the early life history stages of the coral Acropora millepora.}, journal = {Molecular ecology}, volume = {23}, number = {19}, pages = {4682-4695}, doi = {10.1111/mec.12899}, pmid = {25156176}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/growth &amp; development/*microbiology ; Bacteria/*classification/genetics ; Genes, Bacterial ; Life Cycle Stages ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Early establishment of coral-microbial symbioses is fundamental to the fitness of corals, but comparatively little is known about the onset and succession of bacterial communities in their early life history stages. In this study, bacterial associates of the coral Acropora millepora were characterized throughout the first year of life, from larvae and 1-week-old juveniles reared in laboratory conditions in the absence of the dinoflagellate endosymbiont Symbiodinium to field-outplanted juveniles with established Symbiodinium symbioses, and sampled at 2 weeks and at 3, 6 and 12 months. Using an amplicon pyrosequencing approach, the diversity of both nitrogen-fixing bacteria and of bacterial communities overall was assessed through analysis of nifH and 16S rRNA genes, respectively. The consistent presence of sequences affiliated with diazotrophs of the order Rhizobiales (23-58% of retrieved nifH sequences; 2-12% of 16S rRNA sequences), across all samples from larvae to 12-month-old coral juveniles, highlights the likely functional importance of this nitrogen-fixing order to the coral holobiont. Dominance of Roseobacter-affiliated sequences (>55% of retrieved 16S rRNA sequences) in larvae and 1-week-old juveniles, and the consistent presence of sequences related to Oceanospirillales and Altermonadales throughout all early life history stages, signifies their potential importance as coral associates. Increased diversity of bacterial communities once juveniles were transferred to the field, particularly of Cyanobacteria and Deltaproteobacteria, demonstrates horizontal (environmental) uptake of coral-associated bacterial communities. Although overall bacterial communities were dynamic, bacteria with likely important functional roles remain stable throughout early life stages of Acropora millepora.}, }
@article {pmid25147543, year = {2014}, author = {Holmes, DE and Giloteaux, L and Orellana, R and Williams, KH and Robbins, MJ and Lovley, DR}, title = {Methane production from protozoan endosymbionts following stimulation of microbial metabolism within subsurface sediments.}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {366}, pmid = {25147543}, issn = {1664-302X}, abstract = {Previous studies have suggested that protozoa prey on Fe(III)- and sulfate-reducing bacteria that are enriched when acetate is added to uranium contaminated subsurface sediments to stimulate U(VI) reduction. In order to determine whether protozoa continue to impact subsurface biogeochemistry after these acetate amendments have stopped, 18S rRNA and ß-tubulin sequences from this phase of an in situ uranium bioremediation field experiment were analyzed. Sequences most similar to Metopus species predominated, with the majority of sequences most closely related to M. palaeformis, a cilitated protozoan known to harbor methanogenic symbionts. Quantification of mcrA mRNA transcripts in the groundwater suggested that methanogens closely related to Metopus endosymbionts were metabolically active at this time. There was a strong correlation between the number of mcrA transcripts from the putative endosymbiotic methanogen and Metopus ß-tubulin mRNA transcripts during the course of the field experiment, suggesting that the activity of the methanogens was dependent upon the activity of the Metopus species. Addition of the eukaryotic inhibitors cyclohexamide and colchicine to laboratory incubations of acetate-amended subsurface sediments significantly inhibited methane production and there was a direct correlation between methane concentration and Metopus ß-tubulin and putative symbiont mcrA gene copies. These results suggest that, following the stimulation of subsurface microbial growth with acetate, protozoa harboring methanogenic endosymbionts become important members of the microbial community, feeding on moribund biomass and producing methane.}, }
@article {pmid25138709, year = {2014}, author = {Dennis, JW and Durkin, SM and Horsley Downie, JE and Hamill, LC and Anderson, NE and MacLeod, ET}, title = {Sodalis glossinidius prevalence and trypanosome presence in tsetse from Luambe National Park, Zambia.}, journal = {Parasites &amp; vectors}, volume = {7}, number = {}, pages = {378}, pmid = {25138709}, issn = {1756-3305}, mesh = {*Animal Distribution ; Animals ; Enterobacteriaceae/*isolation &amp; purification ; Host-Pathogen Interactions ; Trypanosoma/classification/*isolation &amp; purification ; Tsetse Flies/*microbiology/*parasitology/physiology ; Zambia ; }, abstract = {BACKGROUND: Tsetse flies are the biological vectors of African trypanosomes, the causative agents of sleeping sickness in humans and nagana in animals. The tsetse endosymbiont Sodalis glossinidius has been suggested to play a role in tsetse susceptibility to infection. Here we investigate the prevalence of African trypanosomes within tsetse from the Luambe National Park, Zambia and if there is an association between S. glossinidius and presence of trypanosomes within the tsetse examined.<br><br>METHODS: Tsetse representing three species (Glossina brevipalpis, Glossina morsitans morsitans and Glossina pallidipes), were sampled from Luambe National Park, Zambia. Following DNA extraction, PCR was used to examine the tsetse for presence of trypanosomes and the secondary endosymbiont S. glossinidius.<br><br>RESULTS: S. glossinidius infection rates varied significantly between tsetse species, with G. brevipalpis (93.7%) showing the highest levels of infection followed by G. m. morsitans (17.5%) and G. pallidipes (1.4%). ITS-PCR detected a wide variety of trypanosomes within the tsetse that were analysed. Significant differences were found in terms of trypanosome presence between the three tsetse species. A high proportion of G. m. morsitans were shown to carry T. brucei s.l. DNA (73.7%) and of these around 50% were positive for Trypanosoma brucei rhodesiense. T. vivax, T. godfreyi, T. simiae, T. simiae Tsavo and T. congolense were also detected. No association was found between the occurrence of S. glossinidius and the presence of trypanosome DNA in any of the three tsetse species tested.<br><br>CONCLUSION: The current work shows that T. b. rhodesiense was circulating in Luambe National Park, representing a risk for people living in the park or surrounding area and for tourists visiting the park. The differences in trypanosome DNA presence observed between the different tsetse species tested may indicate host feeding preferences, as the PCR will not discriminate between a fly with an active/resident infection compared to a refractory fly that has fed on an infected animal. This makes it difficult to establish if S. glossinidius may play a role in the susceptibility of tsetse flies to trypanosome infection.}, }
@article {pmid25135816, year = {2015}, author = {Iasur-Kruh, L and Taha-Salaime, L and Robinson, WE and Sharon, R and Droby, S and Perlman, SJ and Zchori-Fein, E}, title = {Microbial associates of the vine mealybug Planococcus ficus (Hemiptera: Pseudococcidae) under different rearing conditions.}, journal = {Microbial ecology}, volume = {69}, number = {1}, pages = {204-214}, pmid = {25135816}, issn = {1432-184X}, mesh = {Animals ; Hemiptera/*microbiology ; }, abstract = {Sap-feeding insects harbor diverse microbial endosymbionts that play important roles in host ecology and evolution, including contributing to host pest status. The vine mealybug, Planococcus ficus, is a serious pest of grapevines, vectoring a number of pathogenic grape viruses. Previous studies have shown that virus transmission is abolished when mealybugs are raised in the laboratory on potato. To examine the possible role of microbial symbionts in virus transmission, the archaeal, bacterial, and fungal microbiota of field and laboratory P. ficus were characterized using molecular and classical microbiological methods. Lab and field colonies of P. ficus harbored different microbiota. While both were dominated by the bacterial obligate nutritional symbionts Moranella and Tremblaya, field samples also harbored a third bacterium that was allied with cluster L, a lineage of bacterial symbionts previously identified in aphids. Archaea were not found in any of the samples. Fungal communities in field-collected mealybugs were dominated by Metschnikowia and Cladosporium species, while those from laboratory-reared mealybugs were dominated by Alternaria and Cladosporium species. In conclusion, this study has identified a diverse set of microbes, most of which appear to be facultatively associated with P. ficus, depending on environmental conditions. The role of various members of the mealybug microbiome, as well as how the host plant affects microbial community structure, remains to be determined.}, }
@article {pmid25133584, year = {2014}, author = {Nunoura, T and Takaki, Y and Kazama, H and Kakuta, J and Shimamura, S and Makita, H and Hirai, M and Miyazaki, M and Takai, K}, title = {Physiological and genomic features of a novel sulfur-oxidizing gammaproteobacterium belonging to a previously uncultivated symbiotic lineage isolated from a hydrothermal vent.}, journal = {PloS one}, volume = {9}, number = {8}, pages = {e104959}, pmid = {25133584}, issn = {1932-6203}, mesh = {Bacterial Secretion Systems/genetics ; Chemotaxis ; Energy Metabolism ; Gammaproteobacteria/*genetics/isolation &amp; purification/ultrastructure ; Genome, Bacterial ; Hydrothermal Vents/*microbiology ; Metabolic Networks and Pathways ; Molecular Sequence Data ; Molecular Typing ; Phylogeny ; Ribosome Subunits, Small, Bacterial/genetics ; *Water Microbiology ; }, abstract = {Strain Hiromi 1, a sulfur-oxidizing gammaproteobacterium was isolated from a hydrothermal vent chimney in the Okinawa Trough and represents a novel genus that may include a phylogenetic group found as endosymbionts of deep-sea gastropods. The SSU rRNA gene sequence similarity between strain Hiromi 1 and the gastropod endosymbionts was approximately 97%. The strain was shown to grow both chemolithoautotrophically and chemolithoheterotrophically with an energy metabolism of sulfur oxidation and O2 or nitrate reduction. Under chemolithoheterotrophic growth conditions, the strain utilized organic acids and proteinaceous compounds as the carbon and/or nitrogen sources but not the energy source. Various sugars did not support growth as a sole carbon source. The observation of chemolithoheterotrophy in this strain is in line with metagenomic analyses of endosymbionts suggesting the occurrence of chemolithoheterotrophy in gammaproteobacterial symbionts. Chemolithoheterotrophy and the presence of homologous genes for virulence- and quorum sensing-related functions suggest that the sulfur-oxidizing chomolithotrophic microbes seek animal bodies and microbial biofilm formation to obtain supplemental organic carbons in hydrothermal ecosystems.}, }
@article {pmid25132535, year = {2014}, author = {Troyo, A and Moreira-Soto, A and Carranza, M and Calderón-Arguedas, O and Hun, L and Taylor, L}, title = {Detection of an undescribed Rickettsia sp. in Ixodes boliviensis from Costa Rica.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {6}, pages = {883-886}, doi = {10.1016/j.ttbdis.2014.07.017}, pmid = {25132535}, issn = {1877-9603}, mesh = {Animals ; Base Sequence ; Cell Line ; Chlorocebus aethiops ; Costa Rica/epidemiology ; DNA, Bacterial/chemistry/genetics ; Dog Diseases/epidemiology/*microbiology ; Dogs ; Ixodes/*microbiology ; Molecular Sequence Data ; Rickettsia/genetics/*isolation &amp; purification ; Rickettsia Infections/epidemiology/microbiology/*veterinary ; Sequence Analysis, DNA/veterinary ; Symbiosis ; Vero Cells ; }, abstract = {Ixodes boliviensis is a tick of carnivores that is common on domestic dogs. The only Rickettsia that has been detected previously in this species is 'Candidatus Rickettsia andeanae'. We report the detection of an undescribed Rickettsia sp., named strain IbR/CRC, in I. boliviensis collected from dogs in Costa Rica. Analyses of gltA, ompA, and htrA partial sequences place Rickettsia sp. strain IbR/CRC in the group of R. monacensis, also close to an endosymbiont of Ixodes scapularis and other undescribed rickettsiae. It was not possible to isolate Rickettsia sp. strain IbR/CRC in Vero E6 or C6/36 cell lines. Isolation and further characterization of Rickettsia sp. strain IbR/CRC and the other undescribed rickettsiae are required to determine their taxonomic status and pathogenic potential.}, }
@article {pmid25132534, year = {2014}, author = {Granquist, EG and Kristiansson, M and Lindgren, PE and Matussek, A and Nødtvedt, A and Okstad, W and Stuen, S}, title = {Evaluation of microbial communities and symbionts in Ixodes ricinus and ungulate hosts (Cervus elaphus and Ovis aries) from shared habitats on the west coast of Norway.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {6}, pages = {780-784}, doi = {10.1016/j.ttbdis.2014.05.005}, pmid = {25132534}, issn = {1877-9603}, mesh = {Anaplasma phagocytophilum/physiology ; Animals ; Arachnid Vectors/*microbiology ; Borrelia/genetics/isolation &amp; purification ; Coinfection ; Deer ; Ecosystem ; Female ; Humans ; Ixodes/*microbiology ; Male ; Norway/epidemiology ; Nymph ; Rickettsia/genetics/*isolation &amp; purification ; Sheep ; Sheep Diseases/*epidemiology/microbiology ; Tick-Borne Diseases/*epidemiology/microbiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Recent reports suggest a potential for transmission of a newly discovered rickettsial endosymbiont, Midichloria mitochondrii, to animals and humans from feeding ticks (Ixodes ricinus). Using molecular methods; I. ricinus, sheep and red deer in Anaplasma phagocytophilum-endemic areas of Norway, were examined to see if they were infected by M. mitochondrii or related organisms like Wolbachia pipientis and Rickettsia spp. A total of 532 ticks collected from pastures, 76 blood samples from grazing lambs and 12 organ samples from hunted deer, were analyzed during the study. All larval pools, 60.4% pooled nymphs and 35.1% of adult ticks were positive for M. mitochondrii. There was a significant difference between geographical areas in the prevalence of M. mitochondrii infection among nymphs. A total of 2.2% pooled nymphs and 5.3% adult ticks were positive for A. phagocytophilum. Eleven percent of pooled nymphs were positive for Borrelia spp, 2.2% of pooled nymphs and 3.5% of adult ticks were positive for Rickettsia spp. and none of the ticks were positive for W. pipientis. The prevalence of A. phagocytophilum infection was 54% and 75% in grazing lambs and deer, respectively. No animals were positive for Borrelia spp., M. mitochondrii, Rickettsia spp. or W. pipientis. The reported findings suggest that M. mitochondrii is widespread in tick populations at different geographical sites, and may appear in co-infection with A. phagocytophilum, Borrelia spp. and Rickettsia spp. in ticks.}, }
@article {pmid25115011, year = {2014}, author = {Santos-Garcia, D and Latorre, A and Moya, A and Gibbs, G and Hartung, V and Dettner, K and Kuechler, SM and Silva, FJ}, title = {Small but powerful, the primary endosymbiont of moss bugs, Candidatus Evansia muelleri, holds a reduced genome with large biosynthetic capabilities.}, journal = {Genome biology and evolution}, volume = {6}, number = {7}, pages = {1875-1893}, pmid = {25115011}, issn = {1759-6653}, mesh = {Animals ; Evolution, Molecular ; Gene Rearrangement ; Halomonadaceae/*genetics/physiology ; Hemiptera/*microbiology ; Microscopy, Electron, Transmission ; Phylogeny ; *Symbiosis ; }, abstract = {Moss bugs (Coleorrhyncha: Peloridiidae) are members of the order Hemiptera, and like many hemipterans, they have symbiotic associations with intracellular bacteria to fulfill nutritional requirements resulting from their unbalanced diet. The primary endosymbiont of the moss bugs, Candidatus Evansia muelleri, is phylogenetically related to Candidatus Carsonella ruddii and Candidatus Portiera aleyrodidarum, primary endosymbionts of psyllids and whiteflies, respectively. In this work, we report the genome of Candidatus Evansia muelleri Xc1 from Xenophyes cascus, which is the only obligate endosymbiont present in the association. This endosymbiont possesses an extremely reduced genome similar to Carsonella and Portiera. It has crossed the borderline to be considered as an autonomous cell, requiring the support of the insect host for some housekeeping cell functions. Interestingly, in spite of its small genome size, Evansia maintains enriched amino acid (complete or partial pathways for ten essential and six nonessential amino acids) and sulfur metabolisms, probably related to the poor diet of the insect, based on bryophytes, which contains very low levels of nitrogenous and sulfur compounds. Several facts, including the congruence of host (moss bugs, whiteflies, and psyllids) and endosymbiont phylogenies and the retention of the same ribosomal RNA operon during genome reduction in Evansia, Portiera, and Carsonella, suggest the existence of an ancient endosymbiotic Halomonadaceae clade associated with Hemiptera. Three possible scenarios for the origin of these three primary endosymbiont genera are proposed and discussed.}, }
@article {pmid25114252, year = {2014}, author = {Hughes, GL and Dodson, BL and Johnson, RM and Murdock, CC and Tsujimoto, H and Suzuki, Y and Patt, AA and Cui, L and Nossa, CW and Barry, RM and Sakamoto, JM and Hornett, EA and Rasgon, JL}, title = {Native microbiome impedes vertical transmission of Wolbachia in Anopheles mosquitoes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {34}, pages = {12498-12503}, pmid = {25114252}, issn = {1091-6490}, support = {R21 AI111175/AI/NIAID NIH HHS/United States ; R21 AI070178/AI/NIAID NIH HHS/United States ; R01 AI067371/AI/NIAID NIH HHS/United States ; R01AI067371/AI/NIAID NIH HHS/United States ; R21AI111175/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Acetobacteraceae/drug effects/growth &amp; development ; Animals ; Anopheles/*microbiology ; Anti-Bacterial Agents/pharmacology ; Biological Evolution ; Disease Transmission, Infectious ; Female ; Infectious Disease Transmission, Vertical ; Microbiota/drug effects ; Ovum/microbiology ; Symbiosis ; Wolbachia/*growth &amp; development ; }, abstract = {Over evolutionary time, Wolbachia has been repeatedly transferred between host species contributing to the widespread distribution of the symbiont in arthropods. For novel infections to be maintained, Wolbachia must infect the female germ line after being acquired by horizontal transfer. Although mechanistic examples of horizontal transfer exist, there is a poor understanding of factors that lead to successful vertical maintenance of the acquired infection. Using Anopheles mosquitoes (which are naturally uninfected by Wolbachia) we demonstrate that the native mosquito microbiota is a major barrier to vertical transmission of a horizontally acquired Wolbachia infection. After injection into adult Anopheles gambiae, some strains of Wolbachia invade the germ line, but are poorly transmitted to the next generation. In Anopheles stephensi, Wolbachia infection elicited massive blood meal-induced mortality, preventing development of progeny. Manipulation of the mosquito microbiota by antibiotic treatment resulted in perfect maternal transmission at significantly elevated titers of the wAlbB Wolbachia strain in A. gambiae, and alleviated blood meal-induced mortality in A. stephensi enabling production of Wolbachia-infected offspring. Microbiome analysis using high-throughput sequencing identified that the bacterium Asaia was significantly reduced by antibiotic treatment in both mosquito species. Supplementation of an antibiotic-resistant mutant of Asaia to antibiotic-treated mosquitoes completely inhibited Wolbachia transmission and partly contributed to blood meal-induced mortality. These data suggest that the components of the native mosquito microbiota can impede Wolbachia transmission in Anopheles. Incompatibility between the microbiota and Wolbachia may in part explain why some hosts are uninfected by this endosymbiont in nature.}, }
@article {pmid25114015, year = {2014}, author = {Carvalho, TL and Balsemão-Pires, E and Saraiva, RM and Ferreira, PC and Hemerly, AS}, title = {Nitrogen signalling in plant interactions with associative and endophytic diazotrophic bacteria.}, journal = {Journal of experimental botany}, volume = {65}, number = {19}, pages = {5631-5642}, doi = {10.1093/jxb/eru319}, pmid = {25114015}, issn = {1460-2431}, mesh = {Bacteria/*metabolism ; Crops, Agricultural ; Endophytes ; Models, Biological ; Nitrogen/*metabolism ; *Nitrogen Fixation ; Plant Root Nodulation ; Plant Roots/microbiology ; Plants/*microbiology ; Signal Transduction ; Symbiosis ; }, abstract = {Some beneficial plant-interacting bacteria can biologically fix N2 to plant-available ammonium. Biological nitrogen fixation (BNF) is an important source of nitrogen (N) input in agriculture and represents a promising substitute for chemical N fertilizers. Diazotrophic bacteria have the ability to develop different types of root associations with different plant species. Among the highest rates of BNF are those measured in legumes nodulated by endosymbionts, an already very well documented model of plant-diazotrophic bacterial association. However, it has also been shown that economically important crops, especially monocots, can obtain a substantial part of their N needs from BNF by interacting with associative and endophytic diazotrophic bacteria, that either live near the root surface or endophytically colonize intercellular spaces and vascular tissues of host plants. One of the best reported outcomes of this association is the promotion of plant growth by direct and indirect mechanisms. Besides fixing N, these bacteria can also produce plant growth hormones, and some species are reported to improve nutrient uptake and increase plant tolerance against biotic and abiotic stresses. Thus, this particular type of plant-bacteria association consists of a natural beneficial system to be explored; however, the regulatory mechanisms involved are still not clear. Plant N status might act as a key signal, regulating and integrating various metabolic processes that occur during association with diazotrophic bacteria. This review will focus on the recent progress in understanding plant association with associative and endophytic diazotrophic bacteria, particularly on the knowledge of the N networks involved in BNF and in the promotion of plant growth.}, }
@article {pmid25113146, year = {2014}, author = {Rodríguez-Gil, JL and Brain, R and Baxter, L and Ruffell, S and McConkey, B and Solomon, K and Hanson, M}, title = {Optimization of culturing conditions for toxicity testing with the alga Oophila sp. (Chlorophyceae), an amphibian endosymbiont.}, journal = {Environmental toxicology and chemistry}, volume = {33}, number = {11}, pages = {2566-2575}, doi = {10.1002/etc.2711}, pmid = {25113146}, issn = {1552-8618}, mesh = {Ambystoma ; Animals ; Chlorophyta/classification/*drug effects ; Culture Media/chemistry ; DNA, Ribosomal ; Geography ; Herbicides/*analysis ; Likelihood Functions ; Phylogeny ; Plants ; Risk Assessment ; *Toxicity Tests ; Urodela ; }, abstract = {Eggs of the yellow-spotted salamander (Ambystoma maculatum) have a symbiotic relationship with green algae. It has been suggested that contaminants that are preferentially toxic to algae, such as herbicides, may impair the symbiont and, hence, indirectly affect the development of the salamander embryo. To enable testing under near-standard conditions for first-tier toxicity screening, the authors isolated the alga from field-collected eggs and identified conditions providing exponential growth rates in the apparent asexual phase of the alga. This approach provided a uniform, single-species culture, facilitating assessment of common toxicity end points and comparison of sensitivity relative to other species. Sequencing of the 18s ribosomal DNA indicated that the isolated alga is closely related to the recently described Oophila amblystomatis but is more similar to other known Chlamydomonas species, suggesting possible biogeographical variability in the genetic identity of the algal symbiont. After a tiered approach to culturing method refinement, a modified Bristol's media with 1 mM NH4 (+) as nitrogen source was found to provide suitable conditions for toxicity testing at 18 °C and 200 µmol m(-2) s(-1) photosynthetically active radiation (PAR) on a 24-h light cycle. The validity of the approach was demonstrated with Zn(2+) as a reference toxicant. Overall, the present study shows that screening for direct effects of contaminants on the algal symbiont without the presence of the host salamander is possible under certain laboratory conditions.}, }
@article {pmid25108781, year = {2014}, author = {Szigeti, A and Kreizinger, Z and Hornok, S and Abichu, G and Gyuranecz, M}, title = {Detection of Francisella-like endosymbiont in Hyalomma rufipes from Ethiopia.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {6}, pages = {818-820}, doi = {10.1016/j.ttbdis.2014.06.002}, pmid = {25108781}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; Ethiopia/epidemiology ; Francisella/*classification/genetics/isolation &amp; purification ; Francisella tularensis/*classification/genetics/isolation &amp; purification ; Humans ; Ixodidae/*microbiology ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; Tularemia/epidemiology/*microbiology ; }, abstract = {The expanding family of Francisellaceae includes the genus Francisella, where several pathogen bacteria, e.g. the zoonotic F. tularensis, and different Francisella-like agents belong to. Francisella-like endosymbionts (FLEs) are widespread in hard and soft ticks and their pathogenicity is unknown. The examination of 296 ticks collected in Ethiopia was performed for the detection of F. tularensis and FLEs using polymerase chain reaction (PCR) assays based on the amplification of 16S rRNA, sdhA and tul4 gene fragments. FLE was described in one Hyalomma rufipes tick based on the 16S rRNA and sdhA gene sequences. The 16S rRNA gene fragment was identical with the ones detected previously in Rhipicephalus sanguineus and Hyalomma marginatum marginatum in Bulgaria. The presence of endosymbionts with identical 16S rRNA gene sequence in both Rhipicephalus and Hyalomma species further supports the hypotheses, that certain FLEs had independent evolution from their tick hosts.}, }
@article {pmid25106622, year = {2014}, author = {Zhu, Q and Kosoy, M and Olival, KJ and Dittmar, K}, title = {Horizontal transfers and gene losses in the phospholipid pathway of bartonella reveal clues about early ecological niches.}, journal = {Genome biology and evolution}, volume = {6}, number = {8}, pages = {2156-2169}, pmid = {25106622}, issn = {1759-6653}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Arthropods/microbiology ; Bacterial Proteins/chemistry/genetics/metabolism ; Bartonella/chemistry/*genetics/physiology ; Bartonella Infections/*microbiology ; Biosynthetic Pathways ; Gene Deletion ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Glycerol-3-Phosphate Dehydrogenase (NAD+)/chemistry/genetics/metabolism ; Humans ; Molecular Sequence Data ; Phospholipids/*genetics/metabolism ; Phylogeny ; Sequence Alignment ; }, abstract = {Bartonellae are mammalian pathogens vectored by blood-feeding arthropods. Although of increasing medical importance, little is known about their ecological past, and host associations are underexplored. Previous studies suggest an influence of horizontal gene transfers in ecological niche colonization by acquisition of host pathogenicity genes. We here expand these analyses to metabolic pathways of 28 Bartonella genomes, and experimentally explore the distribution of bartonellae in 21 species of blood-feeding arthropods. Across genomes, repeated gene losses and horizontal gains in the phospholipid pathway were found. The evolutionary timing of these patterns suggests functional consequences likely leading to an early intracellular lifestyle for stem bartonellae. Comparative phylogenomic analyses discover three independent lineage-specific reacquisitions of a core metabolic gene-NAD(P)H-dependent glycerol-3-phosphate dehydrogenase (gpsA)-from Gammaproteobacteria and Epsilonproteobacteria. Transferred genes are significantly closely related to invertebrate Arsenophonus-, and Serratia-like endosymbionts, and mammalian Helicobacter-like pathogens, supporting a cellular association with arthropods and mammals at the base of extant Bartonella spp. Our studies suggest that the horizontal reacquisitions had a key impact on bartonellae lineage specific ecological and functional evolution.}, }
@article {pmid25105893, year = {2014}, author = {Kurlovs, AH and Li, J and Cheng, D and Zhong, J}, title = {Ixodes pacificus ticks maintain embryogenesis and egg hatching after antibiotic treatment of Rickettsia endosymbiont.}, journal = {PloS one}, volume = {9}, number = {8}, pages = {e104815}, pmid = {25105893}, issn = {1932-6203}, support = {R15 AI082515/AI/NIAID NIH HHS/United States ; #1R15AI082515-01/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Ciprofloxacin/pharmacology ; Female ; Humans ; Ixodes/anatomy &amp; histology/embryology/*microbiology/*physiology ; Male ; Oviposition ; Rickettsia/*drug effects/*physiology ; Rickettsia Infections/microbiology ; *Symbiosis ; Tetracycline/pharmacology ; }, abstract = {Rickettsia is a genus of intracellular bacteria that causes a variety of diseases in humans and other mammals and associates with a diverse group of arthropods. Although Rickettsia appears to be common in ticks, most Rickettsia-tick relationships remain generally uncharacterized. The most intimate of these associations is Rickettsia species phylotype G021, a maternally and transstadially transmitted endosymbiont that resides in 100% of I. pacificus in California. We investigated the effects of this Rickettsia phylotype on I. pacificus reproductive fitness using selective antibiotic treatment. Ciprofloxacin was 10-fold more effective than tetracycline in eliminating Rickettsia from I. pacificus, and quantitative PCR results showed that eggs from the ciprofloxacin-treated ticks contained an average of 0.02 Rickettsia per egg cell as opposed to the average of 0.2 in the tetracycline-treated ticks. Ampicillin did not significantly affect the number of Rickettsia per tick cell in adults or eggs compared to the water-injected control ticks. We found no relationship between tick embryogenesis and rickettsial density in engorged I. pacificus females. Tetracycline treatment significantly delayed oviposition of I. pacificus ticks, but the antibiotic's effect was unlikely related to Rickettsia. We also demonstrated that Rickettsia-free eggs could successfully develop into larvae without any significant decrease in hatching compared to eggs containing Rickettsia. No significant differences in the incubation period, egg hatching rate, and the number of larvae were found between any of the antibiotic-treated groups and the water-injected tick control. We concluded that Rickettsia species phylotype G021 does not have an apparent effect on embryogenesis, oviposition, and egg hatching of I. pacificus.}, }
@article {pmid25103769, year = {2014}, author = {Wang, Z and Wu, M}, title = {Complete Genome Sequence of the Endosymbiont of Acanthamoeba Strain UWC8, an Amoeba Endosymbiont Belonging to the "Candidatus Midichloriaceae" Family in Rickettsiales.}, journal = {Genome announcements}, volume = {2}, number = {4}, pages = {}, pmid = {25103769}, issn = {2169-8287}, abstract = {The endosymbiont of Acanthamoeba strain UWC8 is an obligate amoeba endosymbiont belonging to the family of "Candidatus Midichloriaceae" in Rickettsiales. We report here the complete genome sequence of this bacterium, which should catalyze future studies of amoeba-symbiont interactions.}, }
@article {pmid25102427, year = {2014}, author = {Michalik, A and Jankowska, W and Kot, M and Gołas, A and Szklarzewicz, T}, title = {Symbiosis in the green leafhopper, Cicadella viridis (Hemiptera, Cicadellidae). Association in statu nascendi?.}, journal = {Arthropod structure &amp; development}, volume = {43}, number = {6}, pages = {579-587}, doi = {10.1016/j.asd.2014.07.005}, pmid = {25102427}, issn = {1873-5495}, mesh = {Animals ; Bacteria/classification/genetics/ultrastructure ; *Bacterial Physiological Phenomena ; Female ; Hemiptera/classification/*microbiology/*physiology ; Microscopy, Electron, Transmission ; Ovary/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {The green leafhopper, Cicadella viridis lives in symbiotic association with microorganisms. The ultrastructural and molecular analyses have shown that in the body of the C. viridis two types of bacteriocyte endosymbionts are present. An amplification and sequencing of 16S rRNA genes revealed that large, pleomorphic bacteria display a high similarity (94-100%) to the endosymbiont 'Candidatus Sulcia muelleri' (phylum Bacteroidetes), whereas long, rod-shaped microorganisms are closely related to the γ-proteobacterial symbiont Sodalis (97-99% similarity). Both endosymbionts may be harbored in their own bacteriocytes as well as may co-reside in the same bacteriocytes. The ultrastructural observations have revealed that the Sodalis-like bacteria harboring the same bacteriocytes as bacterium Sulcia may invade the cells of the latter. Bacteria Sulcia and Sodalis-like endosymbionts are transovarially transmitted from one generation to the next. However, Sodalis-like endosymbionts do not invade the ovaries individually, but only inside Sulcia cells. Apart from bacteriocyte endosymbionts, in the body of C. viridis small, rod-shaped bacteria have been detected, and have been identified as being closely related to γ-proteobacterial microorganism Pectobacterium (98-99% similarity). The latter are present in the sheath cells of the bacteriomes containing bacterium Sulcia as well as in fat body cells.}, }
@article {pmid25100187, year = {2014}, author = {Kusari, P and Kusari, S and Spiteller, M and Kayser, O}, title = {Biocontrol potential of endophytes harbored in Radula marginata (liverwort) from the New Zealand ecosystem.}, journal = {Antonie van Leeuwenhoek}, volume = {106}, number = {4}, pages = {771-788}, doi = {10.1007/s10482-014-0247-8}, pmid = {25100187}, issn = {1572-9699}, mesh = {Bacteria/classification/genetics/*isolation &amp; purification ; Embryophyta/*microbiology ; Endophytes/classification/*isolation &amp; purification ; Fungi/classification/genetics/*isolation &amp; purification ; Microbial Interactions ; Molecular Sequence Data ; New Zealand ; Sequence Analysis, DNA ; }, abstract = {Radula marginata and Cannabis sativa L. are two phylogenetically unrelated plant species containing structurally similar secondary metabolites like cannabinoids. The major objective of our work was the isolation, identification, biocontrol efficacies, biofilm forming potential and anti-biofilm ability of endophytic microbial community of the liverwort R. marginata, as compared to bacterial endophytic isolates harbored in C. sativa plants. A total of 15 endophytic fungal and 4 endophytic bacterial isolates were identified, including the presence of a bacterial endosymbiont within an endophytic fungal isolate. The endosymbiont was visible only when the fungus containing it was challenged with two phytopathogens Botrytis cinerea and Trichothecium roseum, highlighting a tripartite microbe-microbe interaction and biocontrol potency of endophytes under biotic stress. We also observed sixteen types of endophytic fungal-pathogen and twelve types of endophytic bacterial-pathogen interactions coupled to varying degree of growth inhibitions of either the pathogen or endophyte or both. This showed the magnitude of biocontrol efficacies of endophytes in aiding plant fitness benefits under different media (environmental) conditions. Additionally, it was ecologically noteworthy to find the presence of similar endophytic bacterial genera in both Radula and Cannabis plants, which exhibited similar functional traits like biofilm formation and general anti-biofilm activities. Thus far, our work underlines the biocontrol potency and defensive functional traits (in terms of antagonism and biofilm formation) of endophytes harbored in liverwort R. marginata as compared to the endophytic community of phylogenetically unrelated but phytochemically similar plant C. sativa.}, }
@article {pmid25089010, year = {2014}, author = {Martins, E and Figueras, A and Novoa, B and Santos, RS and Moreira, R and Bettencourt, R}, title = {Comparative study of immune responses in the deep-sea hydrothermal vent mussel Bathymodiolus azoricus and the shallow-water mussel Mytilus galloprovincialis challenged with Vibrio bacteria.}, journal = {Fish &amp; shellfish immunology}, volume = {40}, number = {2}, pages = {485-499}, doi = {10.1016/j.fsi.2014.07.018}, pmid = {25089010}, issn = {1095-9947}, mesh = {Aggrecans/genetics/metabolism ; Amino Acid Sequence ; Animals ; Chromatography, High Pressure Liquid ; *Gene Expression Regulation ; Gills ; Hydrothermal Vents ; Molecular Sequence Data ; Mytilidae/*genetics/*immunology/microbiology ; Mytilus/genetics/immunology/microbiology ; NF-kappa B/genetics/metabolism ; Spectrometry, Mass, Electrospray Ionization ; Tandem Mass Spectrometry ; Vibrio/*physiology ; }, abstract = {The deep-sea hydrothermal vent mussel Bathymodiolus azoricus and the continental European coast Mytilus galloprovincialis are two bivalves species living in highly distinct marine habitats. Mussels are filter-feeding animals that may accumulate rapidly bacteria from the environment. Contact with microorganism is thus inevitable during feeding processes where gill tissues assume a strategic importance at the interface between the external milieu and the internal body cavities promoting interactions with potential pathogens during normal filtration and a constant challenge to their immune system. In the present study B. azoricus and M. galloprovincialis were exposed to Vibrio alginolyticus, Vibrio anguillarum and Vibrio splendidus suspensions and to a mixture of these Vibrio suspensions, in order to ascertain the expression level of immune genes in gill samples, from both mussel species. The immune gene expressions were analyzed by means of quantitative-Polymerase Chain Reaction (qPCR). The gene expression results revealed that these bivalve species exhibit significant expression differences between 12 h and 24 h post-challenge times, and between the Vibrio strains used. V. splendidus induced the strongest gene expression level in the two bivalve species whereas the NF-κB and Aggrecan were the most significantly differentially expressed between the two mussel species. When comparing exposure times, both B. azoricus and M. galloprovincialis showed similar percentage of up-regulated genes at 12 h while a marked increased of gene expression was observed at 24 h for the majority of the immune genes in M. galloprovincialis. This contrasts with B. azoricus where the majority of the immune genes were down-regulated at 24 h. The 24 h post-challenge gene expression results clearly bring new evidence supporting time-dependent transcriptional activities resembling acute phase-like responses and different immune responses build-up in these two mussel species when challenged with Vibrio bacteria. High Pressure Liquid Chromatography (HPLC)-Electrospray ionization mass spectrometry (ESI-MS/MS) analyses resulted in different peptide sequences from B. azoricus and M. galloprovincialis gill tissues suggesting that naïve animals present differences, at the protein synthesis level, in their natural environment. B. azoricus proteins sequences, mostly of endosymbiont origin, were related to metabolic, energy production, protein synthesis processes and nutritional demands whereas in M. galloprovincialis putative protein functions were assumed to be related to structural and cellular integrity and signaling functions.}, }
@article {pmid25079497, year = {2014}, author = {Patiño-Navarrete, R and Piulachs, MD and Belles, X and Moya, A and Latorre, A and Peretó, J}, title = {The cockroach Blattella germanica obtains nitrogen from uric acid through a metabolic pathway shared with its bacterial endosymbiont.}, journal = {Biology letters}, volume = {10}, number = {7}, pages = {}, pmid = {25079497}, issn = {1744-957X}, mesh = {Amino Acids/biosynthesis/genetics ; Animals ; Bacteroidetes/metabolism ; Base Sequence ; Blattellidae/*genetics/*metabolism ; Dietary Proteins ; Fat Body/metabolism ; Gene Expression Regulation ; Genome, Insect ; *Metabolic Networks and Pathways ; Molecular Sequence Data ; Nitrogen/*metabolism ; Symbiosis ; Uric Acid/*metabolism ; }, abstract = {Uric acid stored in the fat body of cockroaches is a nitrogen reservoir mobilized in times of scarcity. The discovery of urease in Blattabacterium cuenoti, the primary endosymbiont of cockroaches, suggests that the endosymbiont may participate in cockroach nitrogen economy. However, bacterial urease may only be one piece in the entire nitrogen recycling process from insect uric acid. Thus, in addition to the uricolytic pathway to urea, there must be glutamine synthetase assimilating the released ammonia by the urease reaction to enable the stored nitrogen to be metabolically usable. None of the Blattabacterium genomes sequenced to date possess genes encoding for those enzymes. To test the host's contribution to the process, we have sequenced and analysed Blattella germanica transcriptomes from the fat body. We identified transcripts corresponding to all genes necessary for the synthesis of uric acid and its catabolism to urea, as well as for the synthesis of glutamine, asparagine, proline and glycine, i.e. the amino acids required by the endosymbiont. We also explored the changes in gene expression with different dietary protein levels. It appears that the ability to use uric acid as a nitrogen reservoir emerged in cockroaches after its age-old symbiotic association with bacteria.}, }
@article {pmid25077022, year = {2014}, author = {Bing, XL and Xia, WQ and Gui, JD and Yan, GH and Wang, XW and Liu, SS}, title = {Diversity and evolution of the Wolbachia endosymbionts of Bemisia (Hemiptera: Aleyrodidae) whiteflies.}, journal = {Ecology and evolution}, volume = {4}, number = {13}, pages = {2714-2737}, pmid = {25077022}, issn = {2045-7758}, abstract = {Wolbachia is the most prevalent symbiont described in arthropods to date. Wolbachia can manipulate host reproduction, provide nutrition to insect hosts and protect insect hosts from pathogenic viruses. So far, 13 supergroups of Wolbachia have been identified. The whitefly Bemisia tabaci is a complex containing more than 28 morphologically indistinguishable cryptic species. Some cryptic species of this complex are invasive. In this study, we report a comprehensive survey of Wolbachia in B. tabaci and its relative B. afer from 1658 insects representing 54 populations across 13 provinces of China and one state of Australia. Based on the results of PCR or sequencing of the 16S rRNA gene, the overall rates of Wolbachia infection were 79.6% and 0.96% in the indigenous and invasive Bemisia whiteflies, respectively. We detected a new Wolbachia supergroup by sequencing five molecular marker genes including 16S rRNA, groEL, gltA, hcpA, and fbpA genes. Data showed that many protein-coding genes have limitations in detecting and classifying newly identified Wolbachia supergroups and thus raise a challenge to the known Wolbachia MLST standard analysis system. Besides, the other Wolbachia strains detected from whiteflies were clustered into supergroup B. Phylogenetic trees of whitefly mitochondrial cytochrome oxidase subunit I and Wolbachia multiple sequencing typing genes were not congruent. In addition, Wolbachia was also detected outside the special bacteriocytes in two cryptic species by fluorescence in situ hybridization, indicating the horizontal transmission of Wolbachia. Our results indicate that members of Wolbachia are far from well explored.}, }
@article {pmid25072029, year = {2014}, author = {Pruneau, L and Moumène, A and Meyer, DF and Marcelino, I and Lefrançois, T and Vachiéry, N}, title = {Understanding Anaplasmataceae pathogenesis using "Omics" approaches.}, journal = {Frontiers in cellular and infection microbiology}, volume = {4}, number = {}, pages = {86}, pmid = {25072029}, issn = {2235-2988}, mesh = {Anaplasmataceae/*physiology ; Anaplasmataceae Infections/*etiology ; Animals ; Gene Expression Profiling ; *Genomics/methods ; Host-Pathogen Interactions ; Humans ; *Proteomics/methods ; Ticks/microbiology ; Transcriptome ; }, abstract = {This paper examines how "Omics" approaches improve our understanding of Anaplasmataceae pathogenesis, through a global and integrative strategy to identify genes and proteins involved in biochemical pathways key for pathogen-host-vector interactions. The Anaplasmataceae family comprises obligate intracellular bacteria mainly transmitted by arthropods. These bacteria are responsible for major human and animal endemic and emerging infectious diseases with important economic and public health impacts. In order to improve disease control strategies, it is essential to better understand their pathogenesis. Our work focused on four Anaplasmataceae, which cause important animal, human and zoonotic diseases: Anaplasma marginale, A. phagocytophilum, Ehrlichia chaffeensis, and E. ruminantium. Wolbachia spp. an endosymbiont of arthropods was also included in this review as a model of a non-pathogenic Anaplasmataceae. A gap analysis on "Omics" approaches on Anaplasmataceae was performed, which highlighted a lack of studies on the genes and proteins involved in the infection of hosts and vectors. Furthermore, most of the studies have been done on the pathogen itself, mainly on infectious free-living forms and rarely on intracellular forms. In order to perform a transcriptomic analysis of the intracellular stage of development, researchers developed methods to enrich bacterial transcripts from infected cells. These methods are described in this paper. Bacterial genes encoding outer membrane proteins, post-translational modifications, eukaryotic repeated motif proteins, proteins involved in osmotic and oxidative stress and hypothetical proteins have been identified to play a key role in Anaplasmataceae pathogenesis. Further investigations on the function of these outer membrane proteins and hypothetical proteins will be essential to confirm their role in the pathogenesis. Our work underlines the need for further studies in this domain and on host and vector responses to infection.}, }
@article {pmid25071739, year = {2014}, author = {Maróti, G and Kondorosi, E}, title = {Nitrogen-fixing Rhizobium-legume symbiosis: are polyploidy and host peptide-governed symbiont differentiation general principles of endosymbiosis?.}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {326}, pmid = {25071739}, issn = {1664-302X}, abstract = {The symbiosis between rhizobia soil bacteria and legumes is facultative and initiated by nitrogen starvation of the host plant. Exchange of signal molecules between the partners leads to the formation of root nodules where bacteria are converted to nitrogen-fixing bacteroids. In this mutualistic symbiosis, the bacteria provide nitrogen sources for plant growth in return for photosynthates from the host. Depending on the host plant the symbiotic fate of bacteria can either be reversible or irreversible. In Medicago plants the bacteria undergo a host-directed multistep differentiation process culminating in the formation of elongated and branched polyploid bacteria with definitive loss of cell division ability. The plant factors are nodule-specific symbiotic peptides. About 500 of them are cysteine-rich NCR peptides produced in the infected plant cells. NCRs are targeted to the endosymbionts and the concerted action of different sets of peptides governs different stages of endosymbiont maturation. This review focuses on symbiotic plant cell development and terminal bacteroid differentiation and demonstrates the crucial roles of symbiotic peptides by showing an example of multi-target mechanism exerted by one of these symbiotic peptides.}, }
@article {pmid25071729, year = {2014}, author = {Zchori-Fein, E and Lahav, T and Freilich, S}, title = {Variations in the identity and complexity of endosymbiont combinations in whitefly hosts.}, journal = {Frontiers in microbiology}, volume = {5}, number = {}, pages = {310}, pmid = {25071729}, issn = {1664-302X}, abstract = {The target of natural selection is suggested to be the holobiont - the organism together with its associated symbiotic microorganisms. The well-defined endosymbiotic communities of insects make them a useful model for exploring the role of symbiotic interactions in shaping the functional repertoire of plants and animals. Here, we studied the variations in the symbiotic communities of the sweet potato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) by compiling a dataset of over 2000 individuals derived from several independent screenings. The secondary endosymbionts harbored by each individual were clustered into entities termed Facultative Endosymbiont Combinations (FECs), each representing a natural assemblage of co-occurring bacterial genera. The association of FECs with whitefly individuals stratified the otherwise homogeneous population into holobiont units. We both identified bacterial assemblages that are specific to whitefly groups sharing unique genetic backgrounds, and characterized the FEC variations within these groups. The analysis revealed that FEC complexity is positively correlated with both distance from the equator and specificity of the genetic clade of the host insect. These findings highlight the importance of symbiotic combinations in shaping the distribution patterns of B. tabaci and possibly other insect species.}, }
@article {pmid25065123, year = {2014}, author = {Smejkalová, P and Votýpka, J and Lukes, J and Cepicka, I}, title = {First report on trichomonads from true bugs.}, journal = {Folia parasitologica}, volume = {61}, number = {3}, pages = {189-194}, pmid = {25065123}, issn = {0015-5683}, mesh = {Animals ; DNA, Protozoan ; Heteroptera/*parasitology ; Host-Parasite Interactions ; Species Specificity ; Trichomonadida/isolation &amp; purification/*physiology ; }, abstract = {Although the hindgut of some insects represents a rich source of intestinal trichomonads, their diversity is only poorly understood. The aim of the present study was to investigate the presence and abundance of intestinal trichomonads in true bugs (Heteroptera). We microscopically examined intestinal contents of more than 780 specimens belonging to 28 families of true bugs from localities in China, Ghana and Papua New Guinea for the presence of intestinal endosymbionts. More than 120 samples were examined also by means of PCR using trichomonad-specific primers. We determined sequences of SSU rDNA and ITS region of two isolates of the genus Simplicimonas Cepicka, Hampl et Kulda, 2010 and one isolate of Monocercomonas colubrorum (Hammerschmidt, 1844). Although our results showed that trichomonads are very rare inhabitants of the intestine of true bugs, two of three isolated flagellates belong to species specific for reptiles. The possibility of transmission of trichomonads between reptiles and true bugs is discussed.}, }
@article {pmid25059495, year = {2015}, author = {Pathak, M and Verma, M and Srivastava, M and Misra-Bhattacharya, S}, title = {Wolbachia endosymbiont of Brugia malayi elicits a T helper type 17-mediated pro-inflammatory immune response through Wolbachia surface protein.}, journal = {Immunology}, volume = {144}, number = {2}, pages = {231-244}, pmid = {25059495}, issn = {1365-2567}, mesh = {Animals ; Bacterial Outer Membrane Proteins/biosynthesis/genetics/*pharmacology ; Brugia malayi/*immunology/*microbiology ; Cloning, Molecular ; Filariasis/immunology/*microbiology ; Inflammation/immunology ; Interferon-gamma/biosynthesis ; Interleukin-10/biosynthesis ; Interleukin-2/biosynthesis ; Interleukin-4/biosynthesis ; Larva ; Lymph Nodes/immunology/microbiology/parasitology ; Male ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins/biosynthesis/genetics/pharmacology ; Spleen/immunology/microbiology/parasitology ; T-Lymphocytes, Regulatory/*immunology ; Th17 Cells/*immunology ; Th2 Cells/immunology ; Transforming Growth Factor beta/biosynthesis ; Wolbachia/*immunology ; }, abstract = {Wolbachia is an endosymbiotic bacterium of the filarial nematode Brugia malayi. The symbiotic relationship between Wolbachia and its filarial host is dependent on interactions between the proteins of both organisms. However, little is known about Wolbachia proteins that are involved in the inflammatory pathology of the host during lymphatic filariasis. In the present study, we cloned, expressed and purified Wolbachia surface protein (r-wsp) from Wolbachia and administered it to mice, either alone or in combination with infective larvae of B. malayi (Bm-L3) and monitored the developing immune response in infected animals. Our results show that spleens and mesenteric lymph nodes of mice immunized with either r-wsp or infected with Bm-L3 show increased percentages of CD4(+) T helper type 17 (Th17) cells and Th1 cytokines like interferon-γ and interleukin-2 (IL-2) along with decreased percentages of regulatory T cells, Th2 cytokines like IL-4 and IL-10 and transforming growth factor β (TGF-β) levels in culture supernatants of splenocytes. These observations were stronger in mice immunized with r-wsp alone. Interestingly, when mice were first immunized with r-wsp and subsequently infected with Bm-L3, percentages of CD4(+) Th17 cells and Th1 cytokines increased even further while that of regulatory T cells, Th2 cytokines and TGF-β levels decreased. These results for the first time show that r-wsp acts synergistically with Bm-L3 in promoting a pro-inflammatory response by increasing Th17 cells and at the same time diminishes host immunological tolerance by decreasing regulatory T cells and TGF-β secretion.}, }
@article {pmid25052143, year = {2014}, author = {Sicard, M and Dittmer, J and Grève, P and Bouchon, D and Braquart-Varnier, C}, title = {A host as an ecosystem: Wolbachia coping with environmental constraints.}, journal = {Environmental microbiology}, volume = {16}, number = {12}, pages = {3583-3607}, doi = {10.1111/1462-2920.12573}, pmid = {25052143}, issn = {1462-2920}, mesh = {Animals ; Arthropods/genetics/immunology/*microbiology ; Ecosystem ; Environment ; Female ; Gonads/microbiology ; Microbial Interactions ; Nematoda/genetics/immunology/*microbiology ; Phenotype ; *Symbiosis ; Wolbachia/growth &amp; development/*physiology ; }, abstract = {The Wolbachia are intracellular endosymbionts widely distributed among invertebrates. These primarily vertically transmitted α-proteobacteria have been intensively studied during the last decades because of their intriguing interactions with hosts, ranging from reproductive manipulations to mutualism. To optimize their vertical transmission from mother to offspring, the Wolbachia have developed fine-tuned strategies. However, the Wolbachia are not restricted to the female gonads and frequently exhibit wide intra-host distributions. This extensive colonization of somatic organs might be necessary for Wolbachia to develop their diverse extended phenotypes. From an endosymbiont's perspective, the within-host environment potentially presents different environmental constraints. Hence, the Wolbachia have to face different intracellular habitats, their host's immune system as well as other microorganisms co-occurring in the same host individual and sometimes even in the same cell. A means for the Wolbachia to protect themselves from these environmental constraints may be to live 'hidden' in vacuoles within host cells. In this review, we summarize the current knowledge regarding the extent of the Wolbachia pandemic and discuss the various environmental constraints these bacteria may have to face within their 'host ecosystem'. Finally, we identify new avenues for future research to better understand the complexity of Wolbachia's interactions with their intracellular environment.}, }
@article {pmid25050957, year = {2014}, author = {Nakabachi, A and Ishida, K and Hongoh, Y and Ohkuma, M and Miyagishima, SY}, title = {Aphid gene of bacterial origin encodes a protein transported to an obligate endosymbiont.}, journal = {Current biology : CB}, volume = {24}, number = {14}, pages = {R640-R641}, doi = {10.1016/j.cub.2014.06.038}, pmid = {25050957}, issn = {1879-0445}, mesh = {Animals ; Aphids/*genetics ; Bacteria/*genetics ; Gene Transfer, Horizontal ; Genes, Bacterial/*genetics ; Symbiosis/*genetics ; }, }
@article {pmid25049384, year = {2014}, author = {Nakayama, T and Kamikawa, R and Tanifuji, G and Kashiyama, Y and Ohkouchi, N and Archibald, JM and Inagaki, Y}, title = {Complete genome of a nonphotosynthetic cyanobacterium in a diatom reveals recent adaptations to an intracellular lifestyle.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {31}, pages = {11407-11412}, pmid = {25049384}, issn = {1091-6490}, mesh = {*Adaptation, Physiological ; Chromosomes, Bacterial/genetics ; Cyanobacteria/*genetics ; Diatoms/*microbiology ; Electron Transport ; Genome Size ; Genome, Bacterial/*genetics ; Intracellular Space/*microbiology ; Molecular Sequence Data ; Nitrogen Fixation/genetics ; Organelles/metabolism ; Photosynthesis/*genetics ; Symbiosis/genetics ; Thylakoids/metabolism ; }, abstract = {The evolution of mitochondria and plastids from bacterial endosymbionts were key events in the origin and diversification of eukaryotic cells. Although the ancient nature of these organelles makes it difficult to understand the earliest events that led to their establishment, the study of eukaryotic cells with recently evolved obligate endosymbiotic bacteria has the potential to provide important insight into the transformation of endosymbionts into organelles. Diatoms belonging to the family Rhopalodiaceae and their endosymbionts of cyanobacterial origin (i.e., "spheroid bodies") are emerging as a useful model system in this regard. The spheroid bodies, which appear to enable rhopalodiacean diatoms to use gaseous nitrogen, became established after the divergence of extant diatom families. Here we report what is, to our knowledge, the first complete genome sequence of a spheroid body, that of the rhopalodiacean diatom Epithemia turgida. The E. turgida spheroid body (EtSB) genome was found to possess a gene set for nitrogen fixation, as anticipated, but is reduced in size and gene repertoire compared with the genomes of their closest known free-living relatives. The presence of numerous pseudogenes in the EtSB genome suggests that genome reduction is ongoing. Most strikingly, our genomic data convincingly show that the EtSB has lost photosynthetic ability and is metabolically dependent on its host cell, unprecedented characteristics among cyanobacteria, and cyanobacterial symbionts. The diatom-spheroid body endosymbiosis is thus a unique system for investigating the processes underlying the integration of a bacterial endosymbiont into eukaryotic cells.}, }
@article {pmid25048173, year = {2014}, author = {Xu, XH and Su, ZZ and Wang, C and Kubicek, CP and Feng, XX and Mao, LJ and Wang, JY and Chen, C and Lin, FC and Zhang, CL}, title = {The rice endophyte Harpophora oryzae genome reveals evolution from a pathogen to a mutualistic endophyte.}, journal = {Scientific reports}, volume = {4}, number = {}, pages = {5783}, pmid = {25048173}, issn = {2045-2322}, mesh = {Ascomycota/*genetics ; DNA Transposable Elements ; Endophytes/*genetics ; Evolution, Molecular ; Genetic Loci ; Genome, Fungal ; Oryza/*microbiology ; Plant Diseases/microbiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The fungus Harpophora oryzae is a close relative of the pathogen Magnaporthe oryzae and a beneficial endosymbiont of wild rice. Here, we show that H. oryzae evolved from a pathogenic ancestor. The overall genomic structures of H. and M. oryzae were found to be similar. However, during interactions with rice, the expression of 11.7% of all genes showed opposing trends in the two fungi, suggesting differences in gene regulation. Moreover, infection patterns, triggering of host defense responses, signal transduction and nutritional preferences exhibited remarkable differentiation between the two fungi. In addition, the H. oryzae genome was found to contain thousands of loci of transposon-like elements, which led to the disruption of 929 genes. Our results indicate that the gain or loss of orphan genes, DNA duplications, gene family expansions and the frequent translocation of transposon-like elements have been important factors in the evolution of this endosymbiont from a pathogenic ancestor.}, }
@article {pmid25046729, year = {2014}, author = {Slatko, BE and Luck, AN and Dobson, SL and Foster, JM}, title = {Wolbachia endosymbionts and human disease control.}, journal = {Molecular and biochemical parasitology}, volume = {195}, number = {2}, pages = {88-95}, doi = {10.1016/j.molbiopara.2014.07.004}, pmid = {25046729}, issn = {1872-9428}, mesh = {Animals ; Filariasis/drug therapy/*parasitology ; Filarioidea/drug effects/*microbiology/physiology ; Humans ; Nematoda/drug effects/*microbiology/physiology ; Nematode Infections/drug therapy/*parasitology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Most human filarial nematode parasites and arthropods are hosts for a bacterial endosymbiont, Wolbachia. In filaria, Wolbachia are required for normal development, fertility and survival, whereas in arthropods, they are largely parasitic and can influence development and reproduction, but are generally not required for host survival. Due to their obligate nature in filarial parasites, Wolbachia have been a target for drug discovery initiatives using several approaches including diversity and focused library screening and genomic sequence analysis. In vitro and in vivo anti-Wolbachia antibiotic treatments have been shown to have adulticidal activity, a long sought goal of filarial parasite drug discovery. In mosquitoes, it has been shown that the presence of Wolbachia can inhibit the transmission of certain viruses, such as Dengue, Chikungunya, Yellow Fever, West Nile, as well as the infectivity of the malaria-causing protozoan, Plasmodium and filarial nematodes. Furthermore, Wolbachia can cause a form of conditional sterility that can be used to suppress populations of mosquitoes and additional medically important insects. Thus Wolbachia, a pandemic endosymbiont offers great potential for elimination of a wide-variety of devastating human diseases.}, }
@article {pmid25044878, year = {2014}, author = {Grottoli, AG and Warner, ME and Levas, SJ and Aschaffenburg, MD and Schoepf, V and McGinley, M and Baumann, J and Matsui, Y}, title = {The cumulative impact of annual coral bleaching can turn some coral species winners into losers.}, journal = {Global change biology}, volume = {20}, number = {12}, pages = {3823-3833}, doi = {10.1111/gcb.12658}, pmid = {25044878}, issn = {1365-2486}, mesh = {Acclimatization/*physiology ; Analysis of Variance ; Animals ; Anthozoa/*microbiology/*physiology ; Caribbean Region ; Dinoflagellida/*physiology ; Photosynthesis/physiology ; Species Specificity ; Stress, Physiological/*physiology ; *Symbiosis ; *Temperature ; }, abstract = {Mass coral bleaching events caused by elevated seawater temperatures result in extensive coral loss throughout the tropics, and are projected to increase in frequency and severity. If bleaching becomes an annual event later in this century, more than 90% of coral reefs worldwide may be at risk of long-term degradation. While corals can recover from single isolated bleaching and can acclimate to recurring bleaching events that are separated by multiple years, it is currently unknown if and how they will survive and possibly acclimatize to annual coral bleaching. Here, we demonstrate for the first time that annual coral bleaching can dramatically alter thermal tolerance in Caribbean corals. We found that high coral energy reserves and changes in the dominant algal endosymbiont type (Symbiodinium spp.) facilitated rapid acclimation in Porites divaricata, whereas low energy reserves and a lack of algal phenotypic plasticity significantly increased susceptibility in Porites astreoides to bleaching the following year. Phenotypic plasticity in the dominant endosymbiont type of Orbicella faveolata did not prevent repeat bleaching, but may have facilitated rapid recovery. Thus, coral holobiont response to an isolated single bleaching event is not an accurate predictor of its response to bleaching the following year. Rather, the cumulative impact of annual coral bleaching can turn some coral species 'winners' into 'losers', and can also facilitate acclimation and turn some coral species 'losers' into 'winners'. Overall, these findings indicate that cumulative impact of annual coral bleaching could result in some species becoming increasingly susceptible to bleaching and face a long-term decline, while phenotypically plastic coral species will acclimatize and persist. Thus, annual coral bleaching and recovery could contribute to the selective loss of coral diversity as well as the overall decline of coral reefs in the Caribbean.}, }
@article {pmid25041857, year = {2014}, author = {Duron, O}, title = {Arsenophonus insect symbionts are commonly infected with APSE, a bacteriophage involved in protective symbiosis.}, journal = {FEMS microbiology ecology}, volume = {90}, number = {1}, pages = {184-194}, doi = {10.1111/1574-6941.12381}, pmid = {25041857}, issn = {1574-6941}, mesh = {Animals ; Bacteriophages/classification/*genetics/*isolation &amp; purification ; Enterobacteriaceae/*virology ; Evolution, Molecular ; Insecta/*microbiology/virology ; Phylogeny ; Recombination, Genetic ; *Symbiosis ; }, abstract = {Insects commonly have intimate associations with maternally inherited bacterial symbionts. While many inherited symbionts are not essential for host survival, they often act as conditional mutualists, conferring protection against certain environmental stresses. The defensive symbiont Hamiltonella defensa which protects aphids against attacks by parasitoid wasps is one of these conditional mutualists. The protection afforded by Hamiltonella depends on the presence of a lysogenic bacteriophage, called APSE, encoding homologs of toxins that are suspected to target wasp cells. In this study, an important diversity of APSE variants is reported from another heritable symbiont, Arsenophonus, which is exceptionally widespread in insects. APSE was found in association with two-thirds of the Arsenophonus strains examined and from a variety of insect groups such as aphids, white flies, parasitoid wasps, triatomine bugs, louse flies, and bat flies. No APSE was, however, found from Arsenophonus relatives such as the recently described Aschnera chinzeii and ALO-3 endosymbionts. Phylogenetic investigations revealed that APSE has a long evolutionary history in heritable symbionts, being secondarily acquired by Hamiltonella through lateral transfer from Arsenophonus. Overall, this highlights the role of lateral transfer as a major evolutionary process shaping the emergence of defensive symbiosis in heritable bacteria.}, }
@article {pmid25037159, year = {2014}, author = {Dossi, FC and da Silva, EP and Cônsoli, FL}, title = {Population dynamics and growth rates of endosymbionts during Diaphorina citri (Hemiptera, Liviidae) ontogeny.}, journal = {Microbial ecology}, volume = {68}, number = {4}, pages = {881-889}, pmid = {25037159}, issn = {1432-184X}, mesh = {Animals ; Betaproteobacteria/genetics/growth &amp; development/*physiology ; DNA, Bacterial/genetics/metabolism ; Female ; Halomonadaceae/genetics/growth &amp; development/*physiology ; Hemiptera/growth &amp; development/*microbiology ; Male ; Nymph/growth &amp; development/microbiology ; Ovum/growth &amp; development/microbiology ; Population Dynamics ; RNA, Ribosomal, 16S/genetics/metabolism ; Real-Time Polymerase Chain Reaction ; *Symbiosis ; Wolbachia/genetics/growth &amp; development/*physiology ; }, abstract = {The infection density of symbionts is among the major parameters to understand their biological effects in host-endosymbionts interactions. Diaphorina citri harbors two bacteriome-associated bacterial endosymbionts (Candidatus Carsonella ruddii and Candidatus Profftella armatura), besides the intracellular reproductive parasite Wolbachia. In this study, the density dynamics of the three endosymbionts associated with the psyllid D. citri was investigated by real-time quantitative PCR (qPCR) at different developmental stages. Bacterial density was estimated by assessing the copy number of the 16S rRNA gene for Carsonella and Profftella, and of the ftsZ gene for Wolbachia. Analysis revealed a continuous growth of the symbionts during host development. Symbiont growth and rate curves were estimated by the Gompertz equation, which indicated a negative correlation between the degree of symbiont-host specialization and the time to achieve the maximum growth rate (t*). Carsonella densities were significantly lower than those of Profftella at all host developmental stages analyzed, even though they both displayed a similar trend. The growth rates of Wolbachia were similar to those of Carsonella, but Wolbachia was not as abundant. Adult males displayed higher symbiont densities than females. However, females showed a much more pronounced increase in symbiont density as they aged if compared to males, regardless of the incorporation of symbionts into female oocytes and egg laying. The increased density of endosymbionts in aged adults differs from the usual decrease observed during host aging in other insect-symbiont systems.}, }
@article {pmid25035337, year = {2014}, author = {Lee, RD and Jospin, G and Coil, DA and Eisen, JA}, title = {Draft Genome Sequence of the Endosymbiont "Candidatus Ruthia magnifica" UCD-CM (Phylum Proteobacteria).}, journal = {Genome announcements}, volume = {2}, number = {4}, pages = {}, pmid = {25035337}, issn = {2169-8287}, abstract = {Here, we present the draft genome of the endosymbiont "Candidatus Ruthia magnifica" UCD-CM, a member of the phylum Proteobacteria, found from the gills of a deep-sea giant clam, Calyptogena magnifica. The assembly consists of 1,160,249 bp contained in 18 contigs.}, }
@article {pmid25027439, year = {2014}, author = {Herren, JK and Paredes, JC and Schüpfer, F and Arafah, K and Bulet, P and Lemaitre, B}, title = {Insect endosymbiont proliferation is limited by lipid availability.}, journal = {eLife}, volume = {3}, number = {}, pages = {e02964}, pmid = {25027439}, issn = {2050-084X}, support = {339970/ERC_/European Research Council/International ; R01 GM084947/GM/NIGMS NIH HHS/United States ; R01-GM084947/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacterial Load ; Biological Transport ; Diglycerides/*metabolism ; Drosophila melanogaster/chemistry/metabolism/*microbiology ; Female ; Fertility/physiology ; Gene Expression ; Hemolymph/chemistry/metabolism/*microbiology ; Insect Proteins/antagonists &amp; inhibitors/genetics/metabolism ; Lipoproteins/antagonists &amp; inhibitors/genetics/metabolism ; Longevity/physiology ; Male ; RNA, Small Interfering/genetics/metabolism ; Spiroplasma/growth &amp; development/*metabolism ; Symbiosis/physiology ; }, abstract = {Spiroplasma poulsonii is a maternally transmitted bacterial endosymbiont that is naturally associated with Drosophila melanogaster. S. poulsonii resides extracellularly in the hemolymph, where it must acquire metabolites to sustain proliferation. In this study, we find that Spiroplasma proliferation specifically depletes host hemolymph diacylglyceride, the major lipid class transported by the lipoprotein, Lpp. RNAi-mediated knockdown of Lpp expression, which reduces the amount of circulating lipids, inhibits Spiroplasma proliferation demonstrating that bacterial proliferation requires hemolymph-lipids. Altogether, our study shows that an insect endosymbiont acquires specific lipidic metabolites from the transport lipoproteins in the hemolymph of its host. In addition, we show that the proliferation of this endosymbiont is limited by the availability of hemolymph lipids. This feature could limit endosymbiont over-proliferation under conditions of host nutrient limitation as lipid availability is strongly influenced by the nutritional state.}, }
@article {pmid25027232, year = {2014}, author = {Sumrandee, C and Hirunkanokpun, S and Doornbos, K and Kitthawee, S and Baimai, V and Grubhoffer, L and Trinachartvanit, W and Ahantarig, A}, title = {Molecular detection of Rickettsia species in Amblyomma ticks collected from snakes in Thailand.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {6}, pages = {632-640}, doi = {10.1016/j.ttbdis.2014.04.013}, pmid = {25027232}, issn = {1877-9603}, mesh = {Animals ; Arachnid Vectors/classification/*microbiology ; Bacterial Proteins/genetics ; DNA, Bacterial/genetics ; Ixodidae/classification/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/*genetics/*isolation &amp; purification ; Snakes/classification/*parasitology ; Thailand ; }, abstract = {Some reptile ticks are potential vectors of pathogens such as spotted fever group (SFG) rickettsiae. Here, we report for the first time in detail the molecular evidence, DNA sequences and phylogenetic studies, for the presence of Rickettsia spp. in Amblyomma ticks (Amblyomma helvolum and Amblyomma varanense) from snakes in Thailand. A total of 24 tick samples was collected from 4 snake species and identified. A phylogenetic analysis inferred from the partial sequences of the gltA gene indicated that the Rickettsia spp. from 2 Amblyomma helvolum and 1 Amblyomma varanense belong to the same group as the SFG rickettsiae, which are closely related to Rickettsia raoultii strains. In contrast, there was 1 Rickettsia sp. from Amblyomma helvolum grouped into the same clade with other SFG rickettsiae (Rickettsia tamurae, Rickettsia monacensis, and a Rickettsia endosymbiont of Amblyomma dubitatum from Brazil). However, another Rickettsia sp. from Amblyomma varanense was closely related to Rickettsia bellii and Rickettsia sp. strain RDa420 from Thailand. In addition, from phylogenetic results based on the 16S rRNA gene and a concatenated tree of the 3 genes (gltA, ompA, and ompB), we found what may be a novel SFG rickettsia species closely related to Rickettsia raoultii (from both Amblyomma varanense and Amblyomma helvolum). In conclusion, our findings are the first report on the presence of novel SFG rickettsiae in 2 snake tick species, Amblyomma varanense and Amblyomma helvolum in Thailand and in south-eastern Asia.}, }
@article {pmid25024223, year = {2014}, author = {Knox, EB}, title = {The dynamic history of plastid genomes in the Campanulaceae sensu lato is unique among angiosperms.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {30}, pages = {11097-11102}, pmid = {25024223}, issn = {1091-6490}, support = {R01-GM-76012/GM/NIGMS NIH HHS/United States ; }, mesh = {Campanulaceae/*genetics ; *Evolution, Molecular ; Genome, Plastid/*genetics ; *Open Reading Frames ; *Phylogeny ; Plastids/*genetics ; }, abstract = {Why have some plants lost the organizational stability in plastid genomes (plastomes) that evolved in their algal ancestors? During the endosymbiotic transformation of a cyanobacterium into the eukaryotic plastid, most cyanobacterial genes were transferred to the nucleus or otherwise lost from the plastome, and the resulting plastome architecture in land plants confers organizational stability, as evidenced by the conserved gene order among bryophytes and lycophytes, whereas ferns, gymnosperms, and angiosperms share a single, 30-kb inversion. Although some additional gene losses have occurred, gene additions to angiosperm plastomes were previously unknown. Plastomes in the Campanulaceae sensu lato have incorporated dozens of large ORFs (putative protein-coding genes). These insertions apparently caused many of the 125+ large inversions now known in this small eudicot clade. This phylogenetically restricted phenomenon is not biogeographically localized, which indicates that these ORFs came from the nucleus or (less likely) a cryptic endosymbiont.}, }
@article {pmid25009060, year = {2014}, author = {Bingham, BL and Dimond, JL and Muller-Parker, G}, title = {Symbiotic state influences life-history strategy of a clonal cnidarian.}, journal = {Proceedings. Biological sciences}, volume = {281}, number = {1789}, pages = {20140548}, pmid = {25009060}, issn = {1471-2954}, mesh = {Animals ; Body Weight ; Chlorophyta/physiology ; Dinoflagellida/*physiology ; Female ; Germ Cells ; Gonads ; Life Cycle Stages ; Male ; Pacific Ocean ; Reproduction ; Sea Anemones/growth &amp; development/*physiology ; Seasons ; Symbiosis ; Temperature ; Washington ; }, abstract = {Along the North American Pacific coast, the common intertidal sea anemone Anthopleura elegantissima engages in facultative, flexible symbioses with Symbiodinium muscatinei (a dinoflagellate) and Elliptochloris marina (a chlorophyte). Determining how symbiotic state affects host fitness is essential to understanding the ecological significance of engaging in such flexible relationships with diverse symbionts. Fitness consequences of hosting S. muscatinei, E. marina or negligible numbers of either symbiont (aposymbiosis) were investigated by measuring growth, cloning by fission and gonad development after 8.5-11 months of sustained exposure to high, moderate or low irradiance under seasonal environmental conditions. Both symbiotic state and irradiance affected host fitness, leading to divergent life-history strategies. Moderate and high irradiances led to a greater level of gonad development in individuals hosting E. marina, while high irradiance and high summer temperature promoted cloning in individuals hosting S. muscatinei and reduced fitness of aposymbiotic anemones. Associating with S. muscatinei may contribute to the success of A. elegantissima as a spatial competitor on the high shore: (i) by offsetting the costs of living under high temperature and irradiance conditions, and (ii) by promoting a high fission rate and clonal expansion. Our results suggest that basic life-history characteristics of a clonal cnidarian can be affected by the identity of the endosymbionts it hosts.}, }
@article {pmid24995872, year = {2014}, author = {Moran, NA and Bennett, GM}, title = {The tiniest tiny genomes.}, journal = {Annual review of microbiology}, volume = {68}, number = {}, pages = {195-215}, doi = {10.1146/annurev-micro-091213-112901}, pmid = {24995872}, issn = {1545-3251}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Evolution, Molecular ; *Genome Size ; *Genome, Bacterial ; Insecta/microbiology/physiology ; Phylogeny ; Symbiosis ; }, abstract = {Starting in 2006, surprisingly tiny genomes have been discovered from numerous bacterial symbionts of insect hosts. Despite their size, each retains some genes that enable provisioning of limiting nutrients or other capabilities required by hosts. Genome sequence analyses show that genome reduction is an ongoing process, resulting in a continuum of sizes, with the smallest genome currently known at 112 kilobases. Genome reduction is typical in host-restricted symbionts and pathogens, but the tiniest genomes are restricted to symbionts required by hosts and restricted to specialized host cells, resulting from long coevolution with hosts. Genes are lost in all functional categories, but core genes for central informational processes, including genes encoding ribosomal proteins, are mostly retained, whereas genes underlying production of cell envelope components are especially depleted. Thus, these entities retain cell-like properties but are heavily dependent on coadaptation of hosts, which continuously evolve to support the symbionts upon which they depend.}, }
@article {pmid24991850, year = {2014}, author = {Sühnel, S and Ivachuk, Cda S and Schaefer, AL and Pontinha, VA and Martins, ML and Figueras, A and Meyer, GR and Jones, SR and Stewart, JC and Gurney-Smith, HJ and Magalhães, AR and Bower, SM}, title = {Detection of a parasitic amoeba (Order Dactylopodida) in the female gonads of oysters in Brazil.}, journal = {Diseases of aquatic organisms}, volume = {109}, number = {3}, pages = {241-250}, doi = {10.3354/dao02748}, pmid = {24991850}, issn = {0177-5103}, mesh = {Amoebozoa/*isolation &amp; purification ; Animals ; Brazil ; Crassostrea/*parasitology ; Gonads/*parasitology ; Host-Parasite Interactions ; }, abstract = {The impacts of oocyte parasites on the reproductive success of molluscs are largely unknown. In this study, we evaluated the presence of gonad parasites in 6 species of marine bivalve molluscs native to southern Brazil. Cultured bivalves included the mangrove oyster Crassostrea gasar (sometimes called C. brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus and the wing pearl oyster Pteria hirundo. Another species of mangrove oyster, C. rhizophorae, and the carib pointed venus clam Anomalocardia brasiliana (syn. A. flexuosa) were collected from the wild. Molluscs were collected in winter 2009 and summer 2010 for histopathological and molecular evaluation. An unknown ovarian parasite (UOP) was observed in histopathological sections of female gonads of C. gasar and C. rhizophorae. The UOP possessed features suggestive of amoebae, including an irregular outer membrane, frothy cytoplasm, a nucleus with a prominent central nucleolus and a closely associated basophilic parasome. PCR analysis was negative for Marteilioides chungmuensis, Perkinsus spp. and Paramoeba perurans. However, real-time PCR successfully amplified DNA from oyster gonads when using universal Paramoeba spp. primers. Also, conventional PCR amplified DNA using primers specific for Perkinsela amoebae-like organisms (syn. Perkinsiella), which are considered as endosymbionts of Parameoba spp., previously thought to be the parasome. Our results suggest that this UOP is a species of amoeba belonging to 1 of the 2 families of the order Dactylopodida, possibly related to Paramoeba spp. This study represents the first report of this type of organism in oysters. We found that C. gasar and C. rhizophorae were the most susceptible molluscs to these UOPs.}, }
@article {pmid24987960, year = {2014}, author = {Wang, Y and Zhang, W and Lin, Y and Cao, W and Zheng, L and Yang, J}, title = {Phosphorus, nitrogen and chlorophyll-a are significant factors controlling ciliate communities in summer in the northern Beibu Gulf, South China Sea.}, journal = {PloS one}, volume = {9}, number = {7}, pages = {e101121}, pmid = {24987960}, issn = {1932-6203}, mesh = {Biodiversity ; Biomass ; China ; Chlorophyll/*metabolism ; Chlorophyll A ; Ciliophora/*physiology ; Nitrogen/*metabolism ; Phosphorus/*metabolism ; Plankton/*physiology ; *Seasons ; }, abstract = {Ciliates (protozoa) are ubiquitous components of plankton community and play important roles in aquatic ecosystems in regards of their abundance, biomass, diversity and energy turnover. Based on the stratified samples collected from the northern Beibu Gulf in August 2011, species composition, abundance, biomass, diversity and spatial pattern of planktonic ciliates were studied. Furthermore the main environmental factors controlling ciliate communities were determined. A total of 101 species belonging to 44 genera and 7 orders (i.e., Oligotrichida, Haptorida, Euplotida, Sessilida, Pleurostomatida, Scuticociliatida and Tintinnida) were identified. The variation of ciliate communities was significant at horizontal level, but that was not at vertical level. Based on cluster analysis, ciliate communities were divided into three main groups. Redundancy analysis (RDA) revealed that Group A, existing in the waters with higher concentration of phosphorus and nitrogen, was dominated by Tintinnidium primitivum. Group B in the waters with lower temperature and chlorophyll-a concentration, was dominated by Leegaardiella ovalis. Group C, existing in the waters with higher temperature and chlorophyll-a concentration, was dominated by large Strombidium spp. and Mesodinium rubrum. Combining multiple analytic methods, our results strongly supported that phosphorus, nitrogen and chlorophyll-a were the most significant factors affecting the ciliate communities in the northern Beibu Gulf in summer. Concentration of phosphorus and nitrogen primarily influenced ciliate biomass, implying a potential impact of eutrophication on ciliate growth. The correlation with chlorophyll-a concentration, on one hand indicate the response of ciliates to the food availability, and on the other hand, the ciliates containing chloroplasts or endosymbionts may contribute greatly to the chlorophyll-a.}, }
@article {pmid24985194, year = {2014}, author = {Xu, L and Zhang, Y and Wang, L and Chen, W and Wei, G}, title = {Diversity of endophytic bacteria associated with nodules of two indigenous legumes at different altitudes of the Qilian Mountains in China.}, journal = {Systematic and applied microbiology}, volume = {37}, number = {6}, pages = {457-465}, doi = {10.1016/j.syapm.2014.05.009}, pmid = {24985194}, issn = {1618-0984}, mesh = {*Altitude ; Bacteria/*classification/genetics ; China ; Endophytes/*classification ; Fabaceae/*microbiology ; Genes, Bacterial ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S ; Root Nodules, Plant/*microbiology ; }, abstract = {A total of 201 endophytic root nodule-associated bacteria collected from two legumes indigenous to different Qilian Mountain altitudes (Hexi Corridor) were characterized through 16S rDNA polymerase chain reaction (PCR)-restriction fragment length polymorphism, 16S rRNA gene sequence analysis, and enterobacterial repetitive intergenic consensus-PCR clustering. The isolates phylogenetically belonged to 35 species in the Phyllobacterium, Ensifer, Rhizobium, Microvirga, Sphingomonas, Paracoccus, Mycobacterium, Paenibacillus, Cohnella, Sporosarcina, Bacillus, Staphylococcus, Brevibacterium, Xenophilus, Erwinia, Leclercia, Acinetobacter, and Pseudomonas genera. Phylogenetic nodA sequence analysis showed higher similarity to Sinorhizobium meliloti with strains related to the Rhizobium, Sinorhizobium, and Acinetobacter genera. Sequence analysis of the nifH gene revealed that the strains belonging to Xenophilus, Acinetobacter, Phyllobacterium, and Rhizobium had genes similar to those of Mesorhizobium and Sinorhizobium. The results indicated that horizontal gene transfer could have occurred between rhizobia and non-rhizobial endophytes. Canonical correspondence analysis revealed that altitude and host plant species contributed more to the bacterial endosymbiont separation than other ecological factors. This study provided valuable information on the interactions between symbiotic bacteria, non-symbiotic bacteria and their habitats, and thus provided knowledge on their genetic diversity and ecology.}, }
@article {pmid24984774, year = {2014}, author = {Moreira, D and Deschamps, P}, title = {What was the real contribution of endosymbionts to the eukaryotic nucleus? Insights from photosynthetic eukaryotes.}, journal = {Cold Spring Harbor perspectives in biology}, volume = {6}, number = {7}, pages = {a016014}, pmid = {24984774}, issn = {1943-0264}, mesh = {Alveolata/genetics ; Cell Nucleus/*genetics/physiology ; Chlorophyta/genetics ; Diatoms/genetics ; Eukaryota/*genetics/physiology ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Genome, Plastid ; Photosynthesis/*genetics ; Phylogeny ; Plastids/genetics ; Symbiosis/*genetics ; }, abstract = {Eukaryotic genomes are composed of genes of different evolutionary origins. This is especially true in the case of photosynthetic eukaryotes, which, in addition to typical eukaryotic genes and genes of mitochondrial origin, also contain genes coming from the primary plastids and, in the case of secondary photosynthetic eukaryotes, many genes provided by the nuclei of red or green algal endosymbionts. Phylogenomic analyses have been applied to detect those genes and, in some cases, have led to proposing the existence of cryptic, no longer visible endosymbionts. However, detecting them is a very difficult task because, most often, those genes were acquired a long time ago and their phylogenetic signal has been heavily erased. We revisit here two examples, the putative cryptic endosymbiosis of green algae in diatoms and chromerids and of Chlamydiae in the first photosynthetic eukaryotes. We show that the evidence sustaining them has been largely overestimated, and we insist on the necessity of careful, accurate phylogenetic analyses to obtain reliable results.}, }
@article {pmid24983244, year = {2014}, author = {Thaler, AD and Plouviez, S and Saleu, W and Alei, F and Jacobson, A and Boyle, EA and Schultz, TF and Carlsson, J and Van Dover, CL}, title = {Comparative population structure of two deep-sea hydrothermal-vent-associated decapods (Chorocaris sp. 2 and Munidopsis lauensis) from southwestern Pacific back-arc basins.}, journal = {PloS one}, volume = {9}, number = {7}, pages = {e101345}, pmid = {24983244}, issn = {1932-6203}, mesh = {Animals ; Anomura/*genetics ; Base Sequence ; Decapoda/*genetics ; Electron Transport Complex IV/genetics ; *Genetic Variation ; Genetics, Population ; *Hydrothermal Vents ; Microsatellite Repeats ; Mitochondria/genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Snails/genetics ; }, abstract = {Studies of genetic connectivity and population structure in deep-sea chemosynthetic ecosystems often focus on endosymbiont-hosting species that are directly dependent on chemical energy extracted from vent effluent for survival. Relatively little attention has been paid to vent-associated species that are not exclusively dependent on chemosynthetic ecosystems. Here we assess connectivity and population structure of two vent-associated invertebrates--the shrimp Chorocaris sp. 2 and the squat lobster Munidopsis lauensis--that are common at deep-sea hydrothermal vents in the western Pacific. While Chorocaris sp. 2 has only been observed at hydrothermal vent sites, M. lauensis can be found throughout the deep sea but occurs in higher abundance around the periphery of active vents We sequenced mitochondrial COI genes and deployed nuclear microsatellite markers for both species at three sites in Manus Basin and either North Fiji Basin (Chorocaris sp. 2) or Lau Basin (Munidopsis lauensis). We assessed genetic differentiation across a range of spatial scales, from approximately 2.5 km to more than 3000 km. Population structure for Chorocaris sp. 2 was comparable to that of the vent-associated snail Ifremeria nautilei, with a single seemingly well-mixed population within Manus Basin that is genetically differentiated from conspecifics in North Fiji Basin. Population structure for Munidopsis lauensis was more complex, with two genetically differentiated populations in Manus Basin and a third well-differentiated population in Lau Basin. The unexpectedly high level of genetic differentiation between M. lauensis populations in Manus Basin deserves further study since it has implications for conservation and management of diversity in deep-sea hydrothermal vent ecosystems.}, }
@article {pmid24982177, year = {2014}, author = {Nikoh, N and Hosokawa, T and Moriyama, M and Oshima, K and Hattori, M and Fukatsu, T}, title = {Evolutionary origin of insect-Wolbachia nutritional mutualism.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {28}, pages = {10257-10262}, pmid = {24982177}, issn = {1091-6490}, mesh = {Animals ; Base Sequence ; *Bedbugs/metabolism/microbiology ; Biotin/biosynthesis/genetics ; Feeding Behavior/*physiology ; Genes, Bacterial/*physiology ; Genome, Bacterial/*physiology ; Molecular Sequence Data ; Symbiosis/*physiology ; Vitamin B Complex/biosynthesis/genetics ; *Wolbachia/genetics/metabolism ; }, abstract = {Obligate insect-bacterium nutritional mutualism is among the most sophisticated forms of symbiosis, wherein the host and the symbiont are integrated into a coherent biological entity and unable to survive without the partnership. Originally, however, such obligate symbiotic bacteria must have been derived from free-living bacteria. How highly specialized obligate mutualisms have arisen from less specialized associations is of interest. Here we address this evolutionary issue by focusing on an exceptional insect-Wolbachia nutritional mutualism. Although Wolbachia endosymbionts are ubiquitously found in diverse insects and generally regarded as facultative/parasitic associates for their insect hosts, a Wolbachia strain associated with the bedbug Cimex lectularius, designated as wCle, was shown to be essential for host's growth and reproduction via provisioning of B vitamins. We determined the 1,250,060-bp genome of wCle, which was generally similar to the genomes of insect-associated facultative Wolbachia strains, except for the presence of an operon encoding the complete biotin synthetic pathway that was acquired via lateral gene transfer presumably from a coinfecting endosymbiont Cardinium or Rickettsia. Nutritional and physiological experiments, in which wCle-infected and wCle-cured bedbugs of the same genetic background were fed on B-vitamin-manipulated blood meals via an artificial feeding system, demonstrated that wCle certainly synthesizes biotin, and the wCle-provisioned biotin significantly contributes to the host fitness. These findings strongly suggest that acquisition of a single gene cluster consisting of biotin synthesis genes underlies the bedbug-Wolbachia nutritional mutualism, uncovering an evolutionary transition from facultative symbiosis to obligate mutualism facilitated by lateral gene transfer in an endosymbiont lineage.}, }
@article {pmid24968670, year = {2014}, author = {Mingchay, P and Sai-Ngam, A and Phumee, A and Bhakdeenuan, P and Lorlertthum, K and Thavara, U and Tawatsin, A and Choochote, W and Siriyasatien, P}, title = {Wolbachia supergroups A and B in natural populations of medically important filth flies (diptera: muscidae, calliphoridae, and sarcophagidae) in Thailand.}, journal = {The Southeast Asian journal of tropical medicine and public health}, volume = {45}, number = {2}, pages = {309-318}, pmid = {24968670}, issn = {0125-1562}, mesh = {Animals ; Diptera/*microbiology ; Female ; Male ; Muscidae/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; Population Density ; Sarcophagidae/*microbiology ; Thailand ; Wolbachia/*isolation &amp; purification/*physiology ; }, abstract = {Filth flies, belonging to suborder Brachycera (Family; Muscidae, Calliphoridae and Sarcophagidae), are a major cause of nuisance and able to transmit pathogens to humans and animals. These insects are distributed worldwide and their populations are increasing especially in sub-tropical and tropical areas. One strategy for controlling insects employs Wolbachia, which is a group of maternally inherited intracellular bacteria, found in many insect species. The bacteria can cause reproductive abnormalities in their hosts, such as cytoplasmic incompatibility, feminization, parthenogenesis, and male lethality. In this study we determined Wolbachia endosymbionts in natural population of medically important flies (42 females and 9 males) from several geographic regions of Thailand. Wolbachia supergroups A or B were detected in 7 of female flies using PCR specific for wsp. Sequence analysis of wsp showed variations between and within the Wolbachia supergroup. Phylogenetics demonstrated that wsp is able to diverge between Wolbachia supergroups A and B. These data should be useful in future Wolbachia-based programs of fly control.}, }
@article {pmid24963388, year = {2014}, author = {Augustinos, AA and Asimakopoulou, AK and Moraiti, CA and Mavragani-Tsipidou, P and Papadopoulos, NT and Bourtzis, K}, title = {Microsatellite and Wolbachia analysis in Rhagoletis cerasi natural populations: population structuring and multiple infections.}, journal = {Ecology and evolution}, volume = {4}, number = {10}, pages = {1943-1962}, pmid = {24963388}, issn = {2045-7758}, abstract = {Rhagoletis cerasi (Diptera: Tephritidae) is a major pest of sweet and sour cherries in Europe and parts of Asia. Despite its economic significance, there is a lack of studies on the genetic structure of R. cerasi populations. Elucidating the genetic structure of insects of economic importance is crucial for developing phenological-predictive models and environmental friendly control methods. All natural populations of R. cerasi have been found to harbor the endosymbiont Wolbachia pipientis, which widely affects multiple biological traits contributing to the evolution of its hosts, and has been suggested as a tool for the biological control of insect pests and disease vectors. In the current study, the analysis of 18 R. cerasi populations collected in Greece, Germany, and Russia using 13 microsatellite markers revealed structuring of R. cerasi natural populations, even at close geographic range. We also analyzed the Wolbachia infection status of these populations using 16S rRNA-, MLST- and wsp-based approaches. All 244 individuals screened were positive for Wolbachia. Our results suggest the fixation of the wCer1 strain in Greece while wCer2, wCer4, wCer5, and probably other uncharacterized strains were also detected in multiply infected individuals. The role of Wolbachia and its potential extended phenotypes needs a thorough investigation in R. cerasi. Our data suggest an involvement of this symbiont in the observed restriction in the gene flow in addition to a number of different ecological factors.}, }
@article {pmid24951564, year = {2014}, author = {Manzano-Marín, A and Latorre, A}, title = {Settling down: the genome of Serratia symbiotica from the aphid Cinara tujafilina zooms in on the process of accommodation to a cooperative intracellular life.}, journal = {Genome biology and evolution}, volume = {6}, number = {7}, pages = {1683-1698}, pmid = {24951564}, issn = {1759-6653}, mesh = {Animals ; Aphids/classification/genetics/*microbiology ; Buchnera/classification/genetics/physiology ; Gene Rearrangement ; *Phylogeny ; Serratia/classification/*genetics/physiology ; *Symbiosis ; }, abstract = {Particularly interesting cases of mutualistic endosymbioses come from the establishment of co-obligate associations of more than one species of endosymbiotic bacteria. Throughout symbiotic accommodation from a free-living bacterium, passing through a facultative stage and ending as an obligate intracellular one, the symbiont experiences massive genomic losses and phenotypic adjustments. Here, we scrutinized the changes in the coevolution of Serratia symbiotica and Buchnera aphidicola endosymbionts in aphids, paying particular attention to the transformations undergone by S. symbiotica to become an obligate endosymbiont. Although it is already known that S. symbiotica is facultative in Acyrthosiphon pisum, in Cinara cedri it has established a co-obligate endosymbiotic consortium along with B. aphidicola to fulfill the aphid's nutritional requirements. The state of this association in C. tujafilina, an aphid belonging to the same subfamily (Lachninae) that C. cedri, remained unknown. Here, we report the genome of S. symbiotica strain SCt-VLC from the aphid C. tujafilina. While being phylogenetically and genomically very closely related to the facultative endosymbiont S. symbiotica from the aphid A. pisum, it shows a variety of metabolic, genetic, and architectural features, which point toward this endosymbiont being one step closer to an obligate intracellular one. We also describe in depth the process of genome rearrangements suffered by S. symbiotica and the role mobile elements play in gene inactivations. Finally, we postulate the supply to the host of the essential riboflavin (vitamin B2) as key to the establishment of S. symbiotica as a co-obligate endosymbiont in the aphids belonging to the subfamily Lachninane.}, }
@article {pmid24950292, year = {2014}, author = {Dobson, NC and De Grave, S and Johnson, ML}, title = {Linking eye design with host symbiont relationships in pontoniine shrimps (Crustacea, Decapoda, Palaemonidae).}, journal = {PloS one}, volume = {9}, number = {6}, pages = {e99505}, pmid = {24950292}, issn = {1932-6203}, mesh = {Animals ; Bivalvia/physiology ; Ecology ; Eye/*anatomy &amp; histology ; Ocular Physiological Phenomena ; Palaemonidae/*physiology ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {Symbiosis is prevalent in the marine environment with many studies examining the effects of such interactions between host and symbiont. Pontoniine shrimps are a group whose ecology is characterised by symbiotic interactions. This investigation examines the gross morphology of Pontoniinae compound eyes and superficial optical parameters with reference to their symbiotic relationship or lifestyle category; free-living, ectosymbiont, endosymbiont (bivalves) or endosymbiont (non-bivalves). The eye morphologies of free-living and ectosymbiotic species are very similar, yet differ from both forms of endosymbiotic species. Endosymbionts have significantly smaller and simpler eyes with larger facets and bigger interommatidial angles and eye parameters for increased sensitivity levels. However bivalve endosymbionts form an intermediary group between non-bivalve endosymbionts and ectosymbionts as a result of their more active lifestyle. The accessory eye or "nebenauge", although of uncertain function, commonly occurs in free-living Pontoniinae species but rarely in endosymbionts apart from in more primitive species. The variation in morphology reflects tensions between functional requirements and ecological pressures that have strongly influenced eye design in Pontoniinae.}, }
@article {pmid24947409, year = {2014}, author = {Sánchez, C and Itakura, M and Okubo, T and Matsumoto, T and Yoshikawa, H and Gotoh, A and Hidaka, M and Uchida, T and Minamisawa, K}, title = {The nitrate-sensing NasST system regulates nitrous oxide reductase and periplasmic nitrate reductase in Bradyrhizobium japonicum.}, journal = {Environmental microbiology}, volume = {16}, number = {10}, pages = {3263-3274}, doi = {10.1111/1462-2920.12546}, pmid = {24947409}, issn = {1462-2920}, mesh = {Bacterial Proteins/*genetics ; Bradyrhizobium/*enzymology/*genetics/metabolism ; Denitrification ; *Gene Expression Regulation, Bacterial ; Gene Expression Regulation, Enzymologic ; Genome, Bacterial ; Membrane Transport Proteins/genetics ; Mutation ; Nitrate Reductase/*genetics ; Nitrates/*metabolism ; Oxidoreductases/*genetics/metabolism ; Periplasm/enzymology ; RNA-Binding Proteins/genetics ; Rhizosphere ; Soybeans/microbiology ; }, abstract = {The soybean endosymbiont Bradyrhizobium japonicum is able to scavenge the greenhouse gas N2O through the N2O reductase (Nos). In previous research, N2O emission from soybean rhizosphere was mitigated by B. japonicum Nos(++) strains (mutants with increased Nos activity). Here, we report the mechanism underlying the Nos(++) phenotype. Comparative analysis of Nos(++) mutant genomes showed that mutation of bll4572 resulted in Nos(++) phenotype. bll4572 encodes NasS, the nitrate (NO3(-))-sensor of the two-component NasST regulatory system. Transcriptional analyses of nosZ (encoding Nos) and other genes from the denitrification process in nasS and nasST mutants showed that, in the absence of NO3(-) , nasS mutation induces nosZ and nap (periplasmic nitrate reductase) via nasT. NO3(-) addition dissociated the NasS-NasT complex in vitro, suggesting the release of the activator NasT. Disruption of nasT led to a marked decrease in nosZ and nap transcription in cells incubated in the presence of NO3(-). Thus, although NasST is known to regulate the NO3(-)-mediated response of NO3(-) assimilation genes in bacteria, our results show that NasST regulates the NO3(-) -mediated response of nosZ and napE genes, from the dissimilatory denitrification pathway, in B. japonicum.}, }
@article {pmid24945631, year = {2014}, author = {Nag, JK and Shrivastava, N and Chahar, D and Gupta, CL and Bajpai, P and Misra-Bhattacharya, S}, title = {Wolbachia transcription elongation factor "Wol GreA" interacts with α2ββ'σ subunits of RNA polymerase through its dimeric C-terminal domain.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {6}, pages = {e2930}, pmid = {24945631}, issn = {1935-2735}, mesh = {Amino Acid Sequence ; Chromatography, Gel ; Cross-Linking Reagents/metabolism ; DNA-Directed RNA Polymerases/*metabolism ; Fluorometry ; Models, Molecular ; Molecular Docking Simulation ; Molecular Sequence Data ; Phylogeny ; Protein Binding ; Protein Conformation ; *Protein Interaction Domains and Motifs ; *Protein Interaction Mapping ; Transcription Elongation, Genetic ; Transcription Factors/chemistry/*metabolism ; Wolbachia/*enzymology ; }, abstract = {OBJECTIVES: Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for therapy against lymphatic filariasis. Transcription elongation factor GreA is an essential factor that mediates transcriptional transition from abortive initiation to productive elongation by stimulating the escape of RNA polymerase (RNAP) from native prokaryotic promoters. Upon screening of 6257 essential bacterial genes, 57 were suggested as potential future drug targets, and GreA is among these. The current study emphasized the characterization of Wol GreA with its domains.<br><br>Biophysical characterization of Wol GreA with its N-terminal domain (NTD) and C-terminal domain (CTD) was performed with fluorimetry, size exclusion chromatography, and chemical cross-linking. Filter trap and far western blotting were used to determine the domain responsible for the interaction with &#x3b1;2&#x3b2;&#x3b2;'&#x3c3; subunits of RNAP. Protein-protein docking studies were done to explore residual interaction of RNAP with Wol GreA. The factor and its domains were found to be biochemically active. Size exclusion and chemical cross-linking studies revealed that Wol GreA and CTD exist in a dimeric conformation while NTD subsists in monomeric conformation. Asp120, Val121, Ser122, Lys123, and Ser134 are the residues of CTD through which monomers of Wol GreA interact and shape into a dimeric conformation. Filter trap, far western blotting, and protein-protein docking studies revealed that dimeric CTD of Wol GreA through Lys82, Ser98, Asp104, Ser105, Glu106, Tyr109, Glu116, Asp120, Val121, Ser122, Ser127, Ser129, Lys140, Glu143, Val147, Ser151, Glu153, and Phe163 residues exclusively participates in binding with &#x3b1;2&#x3b2;&#x3b2;'&#x3c3; subunits of polymerase.<br><br>CONCLUSIONS/SIGNIFICANCE: To the best of our knowledge, this research is the first documentation of the residual mode of action in wolbachial mutualist. Therefore, findings may be crucial to understanding the transcription mechanism of this &#x3b1;-proteobacteria and in deciphering the role of Wol GreA in filarial development.}, }
@article {pmid24944001, year = {2014}, author = {Giron, D and Glevarec, G}, title = {Cytokinin-induced phenotypes in plant-insect interactions: learning from the bacterial world.}, journal = {Journal of chemical ecology}, volume = {40}, number = {7}, pages = {826-835}, pmid = {24944001}, issn = {1573-1561}, mesh = {Animals ; Bacteria/*drug effects ; Cytokinins/*pharmacology ; Host-Parasite Interactions/drug effects ; Insecta/drug effects/physiology ; Phenotype ; Plant Tumors/microbiology/parasitology ; Plants/*metabolism/microbiology ; }, abstract = {Recently, a renewed interest in cytokinins (CKs) has allowed the characterization of these phytohormones as key regulatory molecules in plant biotic interactions. They have been proved to be instrumental in microbe- and insect-mediated plant phenotypes that can be either beneficial or detrimental for the host-plant. In parallel, insect endosymbiotic bacteria have emerged as key players in plant-insect interactions mediating directly or indirectly fundamental aspects of insect nutrition, such as insect feeding efficiency or the ability to manipulate plant physiology to overcome food nutritional imbalances. However, mechanisms that regulate CK production and the role played by insects and their endosymbionts remain largely unknown. Against this backdrop, studies on plant-associated bacteria have revealed fascinating and complex molecular mechanisms that lead to the production of bacterial CKs and the modulation of plant-borne CKs which ultimately result in profound metabolic and morphological plant modifications. This review highlights major strategies used by plant-associated bacteria that impact the CK homeostasis of their host-plant, to raise parallels with strategies used by phytophagous insects and to discuss the possible role played by endosymbiotic bacteria in these CK-mediated plant phenotypes. We hypothesize that insects employ a CK-mix production strategy that manipulates the phytohormonal balance of their host-plant and overtakes plant gene expression causing a metabolic and morphological habitat modification. In addition, insect endosymbiotic bacteria may prove to be instrumental in these manipulations through the production of bacterial CKs, including specific forms that challenge the CK-degrading capacity of the plant (thus ensuring persistent effects) and the CK-mediated plant defenses.}, }
@article {pmid24941309, year = {2014}, author = {Shahab, M and Verma, M and Pathak, M and Mitra, K and Misra-Bhattacharya, S}, title = {Cloning, expression and characterization of UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) from Wolbachia endosymbiont of human lymphatic filarial parasite Brugia malayi.}, journal = {PloS one}, volume = {9}, number = {6}, pages = {e99884}, pmid = {24941309}, issn = {1932-6203}, mesh = {Alkyl and Aryl Transferases/chemistry/genetics/*metabolism ; Amino Acid Sequence ; Animals ; Bacterial Proteins/chemistry/genetics/metabolism ; Brugia malayi/drug effects/growth &amp; development/*microbiology ; Cloning, Molecular ; Female ; Filariasis/*parasitology ; Fosfomycin/pharmacology ; Gene Expression Regulation, Developmental/drug effects ; Humans ; Hydrogen-Ion Concentration ; Kinetics ; Life Cycle Stages ; Lymphoid Tissue/*parasitology/pathology ; Models, Molecular ; Molecular Sequence Data ; Murinae ; Parasites/drug effects/growth &amp; development/*microbiology ; Peptidoglycan/biosynthesis ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Structural Homology, Protein ; *Symbiosis/drug effects ; Temperature ; Wolbachia/drug effects/*enzymology ; }, abstract = {Wolbachia, an endosymbiont of filarial nematode, is considered a promising target for treatment of lymphatic filariasis. Although functional characterization of the Wolbachia peptidoglycan assembly has not been fully explored, the Wolbachia genome provides evidence for coding all of the genes involved in lipid II biosynthesis, a part of peptidoglycan biosynthesis pathway. UDP-N-acetylglucosamine enolpyruvyl transferase (MurA) is one of the lipid II biosynthesis pathway enzymes and it has inevitably been recognized as an antibiotic target. In view of the vital role of MurA in bacterial viability and survival, MurA ortholog from Wolbachia endosymbiont of Brugia malayi (wBm-MurA) was cloned, expressed and purified for further molecular characterization. The enzyme kinetics and inhibition studies were undertaken using fosfomycin. wBm-MurA was found to be expressed in all the major life stages of B. malayi and was immunolocalized in Wolbachia within the microfilariae and female adults by the confocal microscopy. Sequence analysis suggests that the amino acids crucial for enzymatic activity are conserved. The purified wBm-MurA was shown to possess the EPSP synthase (3-phosphoshikimate 1-carboxyvinyltransferase) like activity at a broad pH range with optimal activity at pH 7.5 and 37°C temperature. The apparent affinity constant (Km) for the substrate UDP-N-acetylglucosamine was found to be 0.03149 mM and for phosphoenolpyruvate 0.009198 mM. The relative enzymatic activity was inhibited ∼2 fold in presence of fosfomycin. Superimposition of the wBm-MurA homology model with the structural model of Haemophilus influenzae (Hi-MurA) suggests binding of fosfomycin at the same active site. The findings suggest wBm-MurA to be a putative antifilarial drug target for screening of novel compounds.}, }
@article {pmid24927644, year = {2014}, author = {Work, TM and Aeby, GS and Lasne, G and Tribollet, A}, title = {Gross and microscopic pathology of hard and soft corals in New Caledonia.}, journal = {Journal of invertebrate pathology}, volume = {120}, number = {}, pages = {50-58}, doi = {10.1016/j.jip.2014.05.007}, pmid = {24927644}, issn = {1096-0805}, mesh = {Animals ; Anthozoa/*microbiology ; New Caledonia ; }, abstract = {We surveyed the reefs of Grande Terre, New Caledonia, for coral diseases in 2010 and 2013. Lesions encountered in hard and soft corals were systematically described at the gross and microscopic level. We sampled paired and normal tissues from 101 and 65 colonies in 2010 and 2013, respectively, comprising 51 species of corals from 27 genera. Tissue loss was the most common gross lesion sampled (40%) followed by discoloration (28%), growth anomalies (13%), bleaching (10%), and flatworm infestation (1%). When grouped by gross lesions, the diversity of microscopic lesions as measured by Shannon-Wiener index was highest for tissue loss, followed by discoloration, bleaching, and growth anomaly. Our findings document an extension of the range of certain diseases such as Porites trematodiasis and endolithic hypermycosis (dark spots) to the Western Pacific as well as the presence of a putative cnidarian endosymbiont. We also expand the range of species infected by cell-associated microbial aggregates, and confirm the trend that these aggregates predominate in dominant genera of corals in the Indo-Pacific. This study highlights the importance of including histopathology as an integral component of baseline coral disease surveys, because a given gross lesion might be associated with multiple potential causative agents.}, }
@article {pmid24927572, year = {2014}, author = {Chaudhary, R and Atamian, HS and Shen, Z and Briggs, SP and Kaloshian, I}, title = {GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {24}, pages = {8919-8924}, pmid = {24927572}, issn = {1091-6490}, mesh = {Animals ; Aphids/*metabolism ; Arabidopsis/immunology/parasitology ; Biological Assay ; Buchnera/*metabolism ; Chaperonin 60/chemistry/*physiology ; Chaperonins/chemistry ; Gene Expression Regulation ; Gene Expression Regulation, Plant ; Mass Spectrometry ; Molecular Sequence Data ; Oxidative Stress ; *Plant Immunity ; Plants, Genetically Modified ; Protein Sorting Signals ; Pseudomonas fluorescens/metabolism ; Respiratory Burst ; Saliva/metabolism ; Solanum/metabolism/parasitology ; Transgenes ; }, abstract = {Aphids are sap-feeding plant pests and harbor the endosymbiont Buchnera aphidicola, which is essential for their fecundity and survival. During plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. Plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (PTI). No aphid-associated molecular pattern has yet been identified. By mass spectrometry, we identified in saliva from potato aphids (Macrosiphum euphorbiae) 105 proteins, some of which originated from Buchnera, including the chaperonin GroEL. Because GroEL is a widely conserved bacterial protein with an essential function, we tested its role in PTI. Applying or infiltrating GroEL onto Arabidopsis (Arabidopsis thaliana) leaves induced oxidative burst and expression of PTI early marker genes. These GroEL-induced defense responses required the known coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1. In addition, in transgenic Arabidopsis plants, inducible expression of groEL activated PTI marker gene expression. Moreover, Arabidopsis plants expressing groEL displayed reduced fecundity of the green peach aphid (Myzus persicae), indicating enhanced resistance against aphids. Furthermore, delivery of GroEL into tomato (Solanum lycopersicum) or Arabidopsis through Pseudomonas fluorescens, engineered to express the type III secretion system, also reduced potato aphid and green peach aphid fecundity, respectively. Collectively our data indicate that GroEL is a molecular pattern that triggers PTI.}, }
@article {pmid24926801, year = {2014}, author = {da Rocha Fernandes, M and Martins, R and Pessoa Costa, E and Pacidônio, EC and Araujo de Abreu, L and da Silva Vaz, I and Moreira, LA and da Fonseca, RN and Logullo, C}, title = {The modulation of the symbiont/host interaction between Wolbachia pipientis and Aedes fluviatilis embryos by glycogen metabolism.}, journal = {PloS one}, volume = {9}, number = {6}, pages = {e98966}, pmid = {24926801}, issn = {1932-6203}, mesh = {Aedes/*embryology/metabolism/*microbiology ; Animals ; Embryo, Nonmammalian/microbiology ; Embryonic Development/physiology ; Female ; Glucose-6-Phosphate/metabolism ; Glycogen/*metabolism ; Glycogen Synthase Kinase 3/genetics ; Host-Parasite Interactions/*physiology ; Male ; Phylogeny ; Symbiosis/*physiology ; Wolbachia/metabolism/*physiology ; }, abstract = {Wolbachia pipientis, a maternally transmitted bacterium that colonizes arthropods, may affect the general aspects of insect physiology, particularly reproduction. Wolbachia is a natural endosymbiont of Aedes fluviatilis, whose effects in embryogenesis and reproduction have not been addressed so far. In this context, we investigated the correlation between glucose metabolism and morphological alterations during A. fluviatilis embryo development in Wolbachia-positive (W+) and Wolbachia-negative (W-) mosquito strains. While both strains do not display significant morphological and larval hatching differences, larger differences were observed in hexokinase activity and glycogen contents during early and mid-stages of embryogenesis, respectively. To investigate if glycogen would be required for parasite-host interaction, we reduced Glycogen Synthase Kinase-3 (GSK-3) levels in adult females and their eggs by RNAi. GSK-3 knock-down leads to embryonic lethality, lower levels of glycogen and total protein and Wolbachia reduction. Therefore, our results suggest that the relationship between A. fluviatilis and Wolbachia may be modulated by glycogen metabolism.}, }
@article {pmid24915875, year = {2014}, author = {Duron, O and Jourdain, E and McCoy, KD}, title = {Diversity and global distribution of the Coxiella intracellular bacterium in seabird ticks.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {5}, pages = {557-563}, doi = {10.1016/j.ttbdis.2014.04.003}, pmid = {24915875}, issn = {1877-9603}, mesh = {Animal Distribution ; Animals ; Bird Diseases/microbiology/*parasitology ; *Charadriiformes ; Coxiella/classification/*genetics ; Tick Infestations/parasitology/*veterinary ; Ticks/*microbiology ; }, abstract = {The obligate intracellular bacterium Coxiella burnetii is the etiological agent of Q fever, a widespread zoonotic disease whose most common animal reservoirs are domestic ruminants. Recently, a variety of Coxiella-like organisms have also been reported from non-mammalian hosts, including pathogenic forms in birds and forms without known effects in ticks, raising questions about the potential importance of non-mammalian hosts as reservoirs of Coxiella in the wild. In the present study, we examined the potential role of globally-distributed seabird ticks as reservoirs of these bacteria. To this aim, we tested for Coxiella infection 11 geographically distinct populations of two tick species frequently found in seabird breeding colonies, the hard tick Ixodes uriae (Ixodidae) and soft ticks of the Ornithodoros (Carios) capensis group (Argasidae). We found Coxiella-like organisms in all O. capensis sensu lato specimens, but only in a few I. uriae specimens of one population. The sequencing of 16S rDNA and GroEL gene sequences further revealed an unexpected Coxiella diversity, with seven genetically distinct Coxiella-like organisms present in seabird tick populations. Phylogenetic analyses show that these Coxiella-like organisms originate from three divergent subclades within the Coxiella genus and that none of the Coxiella strains found in seabird ticks are genetically identical to the forms known to be associated with pathogenicity in vertebrates, including C. burnetii. Using this data set, we discuss the potential epidemiological significance of the presence of Coxiella in seabird ticks. Notably, we suggest that these organisms may not be pathogenic forms, but rather behave as endosymbionts engaged in intricate interactions with their tick hosts.}, }
@article {pmid24912954, year = {2014}, author = {Landum, M and Ferreira, CC and Calado, M and Alho, AM and Maurício, IL and Meireles, JS and de Carvalho, LM and Cunha, C and Belo, S}, title = {Detection of Wolbachia in Dirofilaria infected dogs in Portugal.}, journal = {Veterinary parasitology}, volume = {204}, number = {3-4}, pages = {407-410}, doi = {10.1016/j.vetpar.2014.05.027}, pmid = {24912954}, issn = {1873-2550}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Dirofilaria immitis/*immunology/isolation &amp; purification ; Dirofilariasis/*parasitology/prevention &amp; control ; Dog Diseases/*parasitology/prevention &amp; control ; Dogs ; Doxycycline/*therapeutic use ; Female ; Male ; Microfilariae ; Portugal/epidemiology ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia pipiens, an intracellular endosymbiont bacteria of filarial nematodes, has been implicated in the pathogenesis of filarial diseases, in particular in heavy Dirofilaria spp. infections. Antibiotic therapy (doxycycline) against Wolbachia has been proven to be suitable adjunct therapy, prior to adulticide treatment of canine dirofilariosis. Despite its importance, investigation on the Wolbachia/Dirofilaria complex in Portugal had not been undertaken so far. This study reports the first detection of Wolbachia in Dirofilaria spp. infected dogs in the context of an ongoing epidemiological survey in central-south regions in the country. Wolbachia DNA was detected by PCR in 52.6% (20/38) of canine blood samples positive for Dirofilaria immitis based on parasitological (Knott's and Acid Phosphatase) and serological (Witness(®)Dirofilaria) methods. No Wolbachia DNA could be detected in samples from dogs with occult infections (parasite negative but antigen positive). The lack of Wolbachia detection in some microfilaremic dogs was somewhat unexpected and needs to be elucidated in further studies, as the presence or absence of these bacteria in association with microfilaria is of importance for veterinarians in the management and control of canine dirofilariosis.}, }
@article {pmid24911519, year = {2014}, author = {Chrostek, E and Marialva, MS and Yamada, R and O'Neill, SL and Teixeira, L}, title = {High anti-viral protection without immune upregulation after interspecies Wolbachia transfer.}, journal = {PloS one}, volume = {9}, number = {6}, pages = {e99025}, pmid = {24911519}, issn = {1932-6203}, support = {//Wellcome Trust/United Kingdom ; 094664/Z/10/Z/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Drosophila melanogaster/*immunology/microbiology/*virology ; Evolution, Molecular ; Longevity ; Phenotype ; Polymorphism, Genetic ; Symbiosis ; Wolbachia/*immunology/*virology ; }, abstract = {Wolbachia, endosymbionts that reside naturally in up to 40-70% of all insect species, are some of the most prevalent intracellular bacteria. Both Wolbachia wAu, naturally associated with Drosophila simulans, and wMel, native to Drosophila melanogaster, have been previously described to protect their hosts against viral infections. wMel transferred to D. simulans was also shown to have a strong antiviral effect. Here we directly compare one of the most protective wMel variants and wAu in D. melanogaster in the same host genetic background. We conclude that wAu protects better against viral infections, it grows exponentially and significantly shortens the lifespan of D. melanogaster. However, there is no difference between wMel and wAu in the expression of selected antimicrobial peptides. Therefore, neither the difference in anti-viral effect nor the life-shortening could be attributed to the immune stimulation by exogenous Wolbachia. Overall, we prove that stable transinfection with a highly protective Wolbachia is not necessarily associated with general immune activation.}, }
@article {pmid24911315, year = {2014}, author = {Greiman, SE and Tkach, VV and Pulis, E and Fayton, TJ and Curran, SS}, title = {Large scale screening of digeneans for Neorickettsia endosymbionts using real-time PCR reveals new Neorickettsia genotypes, host associations and geographic records.}, journal = {PloS one}, volume = {9}, number = {6}, pages = {e98453}, pmid = {24911315}, issn = {1932-6203}, support = {R15 AI092622/AI/NIAID NIH HHS/United States ; R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/genetics/isolation &amp; purification ; Genetic Variation ; *Genotype ; *Geography ; *Host-Parasite Interactions ; Neorickettsia/classification/*genetics/*physiology ; Phylogeny ; Real-Time Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Symbiosis ; Trematoda/*microbiology/physiology ; }, abstract = {Digeneans are endoparasitic flatworms with complex life cycles including one or two intermediate hosts (first of which is always a mollusk) and a vertebrate definitive host. Digeneans may harbor intracellular endosymbiotic bacteria belonging to the genus Neorickettsia (order Rickettsiales, family Anaplasmataceae). Some Neorickettsia are able to invade cells of the digenean's vertebrate host and are known to cause diseases of wildlife and humans. In this study we report the results of screening 771 digenean samples for Neorickettsia collected from various vertebrates in terrestrial, freshwater, brackish, and marine habitats in the United States, China and Australia. Neorickettsia were detected using a newly designed real-time PCR protocol targeting a 152 bp fragment of the heat shock protein coding gene, GroEL, and verified with nested PCR and sequencing of a 1371 bp long region of 16S rRNA. Eight isolates of Neorickettsia have been obtained. Sequence comparison and phylogenetic analysis demonstrated that 7 of these isolates, provisionally named Neorickettsia sp. 1-7 (obtained from allocreadiid Crepidostomum affine, haploporids Saccocoelioides beauforti and Saccocoelioides lizae, faustulid Bacciger sprenti, deropegid Deropegus aspina, a lecithodendriid, and a pleurogenid) represent new genotypes and one (obtained from Metagonimoides oregonensis) was identical to a published sequence of Neorickettsia known as SF agent. All digenean species reported in this study represent new host records. Three of the 6 digenean families (Haploporidae, Pleurogenidae, and Faustulidae) are also reported for the first time as hosts of Neorickettsia. We have detected Neorickettsia in digeneans from China and Australia for the first time based on PCR and sequencing evidence. Our findings suggest that further surveys from broader geographic regions and wider selection of digenean taxa are likely to reveal new Neorickettsia lineages as well as new digenean host associations.}, }
@article {pmid24909707, year = {2014}, author = {Baums, IB and Devlin-Durante, MK and LaJeunesse, TC}, title = {New insights into the dynamics between reef corals and their associated dinoflagellate endosymbionts from population genetic studies.}, journal = {Molecular ecology}, volume = {23}, number = {17}, pages = {4203-4215}, doi = {10.1111/mec.12788}, pmid = {24909707}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*genetics ; Caribbean Region ; Coral Reefs ; Dinoflagellida/*genetics ; Gene Flow ; *Genetics, Population ; Genotype ; Linkage Disequilibrium ; Microsatellite Repeats ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The mutualistic symbioses between reef-building corals and micro-algae form the basis of coral reef ecosystems, yet recent environmental changes threaten their survival. Diversity in host-symbiont pairings on the sub-species level could be an unrecognized source of functional variation in response to stress. The Caribbean elkhorn coral, Acropora palmata, associates predominantly with one symbiont species (Symbiodinium 'fitti'), facilitating investigations of individual-level (genotype) interactions. Individual genotypes of both host and symbiont were resolved across the entire species' range. Most colonies of a particular animal genotype were dominated by one symbiont genotype (or strain) that may persist in the host for decades or more. While Symbiodinium are primarily clonal, the occurrence of recombinant genotypes indicates sexual recombination is the source of this genetic variation, and some evidence suggests this happens within the host. When these data are examined at spatial scales spanning the entire distribution of A. palmata, gene flow among animal populations was an order of magnitude greater than among populations of the symbiont. This suggests that independent micro-evolutionary processes created dissimilar population genetic structures between host and symbiont. The lower effective dispersal exhibited by the dinoflagellate raises questions regarding the extent to which populations of host and symbiont can co-evolve during times of rapid and substantial climate change. However, these findings also support a growing body of evidence, suggesting that genotype-by-genotype interactions may provide significant physiological variation, influencing the adaptive potential of symbiotic reef corals to severe selection.}, }
@article {pmid24909063, year = {2014}, author = {Tamarozzi, F and Wright, HL and Johnston, KL and Edwards, SW and Turner, JD and Taylor, MJ}, title = {Human filarial Wolbachia lipopeptide directly activates human neutrophils in vitro.}, journal = {Parasite immunology}, volume = {36}, number = {10}, pages = {494-502}, pmid = {24909063}, issn = {1365-3024}, mesh = {Animals ; Apoptosis ; Chemotaxis ; Humans ; Interleukin-8/immunology ; Lipopeptides/*immunology ; Neutrophils/*immunology/pathology ; Onchocerca volvulus/*microbiology ; Onchocerciasis, Ocular/*immunology/parasitology ; Respiratory Burst ; Wolbachia/*immunology ; }, abstract = {The host inflammatory response to the Onchocerca volvulus endosymbiont, Wolbachia, is a major contributing factor in the development of chronic pathology in humans (onchocerciasis/river blindness). Recently, the toll-like pattern recognition receptor motif of the major inflammatory ligands of filarial Wolbachia, membrane-associated diacylated lipoproteins, was functionally defined in murine models of pathology, including mediation of neutrophil recruitment to the cornea. However, the extent to which human neutrophils can be activated in response to this Wolbachia pattern recognition motif is not known. Therefore, the responses of purified peripheral blood human neutrophils to a synthetic N-terminal diacylated lipopeptide (WoLP) of filarial Wolbachia peptidoglycan-associated lipoprotein (PAL) were characterized. WoLP exposure led to a dose-dependent activation of healthy, human neutrophils that included gross morphological alterations and modulation of surface expressed integrins involved in tethering, rolling and extravasation. WoLP exposure induced chemotaxis but not chemokinesis of neutrophils, and secretion of the major neutrophil chemokine, interleukin 8. WoLP also induced and primed the respiratory burst, and enhanced neutrophil survival by delay of apoptosis. These results indicate that the major inflammatory motif of filarial Wolbachia lipoproteins directly activates human neutrophils in vitro and promotes a molecular pathway by which human neutrophils are recruited to sites of Onchocerca parasitism.}, }
@article {pmid24901418, year = {2014}, author = {Koutsovoulos, G and Makepeace, B and Tanya, VN and Blaxter, M}, title = {Palaeosymbiosis revealed by genomic fossils of Wolbachia in a strongyloidean nematode.}, journal = {PLoS genetics}, volume = {10}, number = {6}, pages = {e1004397}, pmid = {24901418}, issn = {1553-7404}, support = {095831//Wellcome Trust/United Kingdom ; /BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Base Sequence ; Cattle ; Cattle Diseases/microbiology/parasitology ; DNA, Bacterial/*genetics ; DNA, Protozoan/*genetics ; Dictyocaulus/*genetics/*microbiology ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {Wolbachia are common endosymbionts of terrestrial arthropods, and are also found in nematodes: the animal-parasitic filaria, and the plant-parasite Radopholus similis. Lateral transfer of Wolbachia DNA to the host genome is common. We generated a draft genome sequence for the strongyloidean nematode parasite Dictyocaulus viviparus, the cattle lungworm. In the assembly, we identified nearly 1 Mb of sequence with similarity to Wolbachia. The fragments were unlikely to derive from a live Wolbachia infection: most were short, and the genes were disabled through inactivating mutations. Many fragments were co-assembled with definitively nematode-derived sequence. We found limited evidence of expression of the Wolbachia-derived genes. The D. viviparus Wolbachia genes were most similar to filarial strains and strains from the host-promiscuous clade F. We conclude that D. viviparus was infected by Wolbachia in the past, and that clade F-like symbionts may have been the source of filarial Wolbachia infections.}, }
@article {pmid24885563, year = {2014}, author = {Tanifuji, G and Onodera, NT and Brown, MW and Curtis, BA and Roger, AJ and Ka-Shu Wong, G and Melkonian, M and Archibald, JM}, title = {Nucleomorph and plastid genome sequences of the chlorarachniophyte Lotharella oceanica: convergent reductive evolution and frequent recombination in nucleomorph-bearing algae.}, journal = {BMC genomics}, volume = {15}, number = {1}, pages = {374}, pmid = {24885563}, issn = {1471-2164}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Base Sequence ; Biological Evolution ; Cercozoa/classification/*genetics ; Chromosome Mapping ; Chromosomes/genetics/metabolism ; Cryptophyta/genetics ; *Genome, Plastid ; Introns ; Molecular Sequence Data ; Phylogeny ; Plastids/*genetics ; Recombination, Genetic ; Sequence Analysis, DNA ; }, abstract = {BACKGROUND: Nucleomorphs are residual nuclei derived from eukaryotic endosymbionts in chlorarachniophyte and cryptophyte algae. The endosymbionts that gave rise to nucleomorphs and plastids in these two algal groups were green and red algae, respectively. Despite their independent origin, the chlorarachniophyte and cryptophyte nucleomorph genomes share similar genomic features such as extreme size reduction and a three-chromosome architecture. This suggests that similar reductive evolutionary forces have acted to shape the nucleomorph genomes in the two groups. Thus far, however, only a single chlorarachniophyte nucleomorph and plastid genome has been sequenced, making broad evolutionary inferences within the chlorarachniophytes and between chlorarachniophytes and cryptophytes difficult. We have sequenced the nucleomorph and plastid genomes of the chlorarachniophyte Lotharella oceanica in order to gain insight into nucleomorph and plastid genome diversity and evolution.<br><br>RESULTS: The L. oceanica nucleomorph genome was found to consist of three linear chromosomes totaling ~610 kilobase pairs (kbp), much larger than the 373&#xa0;kbp nucleomorph genome of the model chlorarachniophyte Bigelowiella natans. The L. oceanica plastid genome is 71&#xa0;kbp in size, similar to that of B. natans. Unexpectedly long (~35&#xa0;kbp) sub-telomeric repeat regions were identified in the L. oceanica nucleomorph genome; internal multi-copy regions were also detected. Gene content analyses revealed that nucleomorph house-keeping genes and spliceosomal intron positions are well conserved between the L. oceanica and B. natans nucleomorph genomes. More broadly, gene retention patterns were found to be similar between nucleomorph genomes in chlorarachniophytes and cryptophytes. Chlorarachniophyte plastid genomes showed near identical protein coding gene complements as well as a high level of synteny.<br><br>CONCLUSIONS: We have provided insight into the process of nucleomorph genome evolution by elucidating the fine-scale dynamics of sub-telomeric repeat regions. Homologous recombination at the chromosome ends appears to be frequent, serving to expand and contract nucleomorph genome size. The main factor influencing nucleomorph genome size variation between different chlorarachniophyte species appears to be expansion-contraction of these telomere-associated repeats rather than changes in the number of unique protein coding genes. The dynamic nature of chlorarachniophyte nucleomorph genomes lies in stark contrast to their plastid genomes, which appear to be highly stable in terms of gene content and synteny.}, }
@article {pmid24885505, year = {2014}, author = {Schneider, DI and Klasson, L and Lind, AE and Miller, WJ}, title = {More than fishing in the dark: PCR of a dispersed sequence produces simple but ultrasensitive Wolbachia detection.}, journal = {BMC microbiology}, volume = {14}, number = {}, pages = {121}, pmid = {24885505}, issn = {1471-2180}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; DNA, Bacterial/genetics/*isolation &amp; purification ; Drosophila/microbiology/physiology ; Hymenoptera/microbiology/physiology ; *Interspersed Repetitive Sequences ; Polymerase Chain Reaction/*methods ; *Symbiosis ; Tsetse Flies/microbiology/physiology ; Wolbachia/*isolation &amp; purification/physiology ; }, abstract = {BACKGROUND: Detecting intracellular bacterial symbionts can be challenging when they persist at very low densities. Wolbachia, a widespread bacterial endosymbiont of invertebrates, is particularly challenging. Although it persists at high titers in many species, in others its densities are far below the detection limit of classic end-point Polymerase Chain Reaction (PCR). These low-titer infections can be reliably detected by combining PCR with DNA hybridization, but less elaborate strategies based on end-point PCR alone have proven less sensitive or less general.<br><br>RESULTS: We introduce a multicopy PCR target that allows fast and reliable detection of A-supergroup Wolbachia--even at low infection titers--with standard end-point PCR. The target is a multicopy motif (designated ARM: A-supergroup repeat motif) discovered in the genome of wMel (the Wolbachia in Drosophila melanogaster). ARM is found in at least seven other Wolbachia A-supergroup strains infecting various Drosophila, the wasp Muscidifurax and the tsetse fly Glossina. We demonstrate that end-point PCR targeting ARM can reliably detect both high- and low-titer Wolbachia infections in Drosophila, Glossina and interspecific hybrids.<br><br>CONCLUSIONS: Simple end-point PCR of ARM facilitates detection of low-titer Wolbachia A-supergroup infections. Detecting these infections previously required more elaborate procedures. Our ARM target seems to be a general feature of Wolbachia A-supergroup genomes, unlike other multicopy markers such as insertion sequences (IS).}, }
@article {pmid24883247, year = {2014}, author = {Green, EA and Davies, SW and Matz, MV and Medina, M}, title = {Quantifying cryptic Symbiodinium diversity within Orbicella faveolata and Orbicella franksi at the Flower Garden Banks, Gulf of Mexico.}, journal = {PeerJ}, volume = {2}, number = {}, pages = {e386}, pmid = {24883247}, issn = {2167-8359}, abstract = {The genetic composition of the resident Symbiodinium endosymbionts can strongly modulate the physiological performance of reef-building corals. Here, we used quantitative metabarcoding to investigate Symbiodinium genetic diversity in two species of mountainous star corals, Orbicella franksi and Orbicella faveolata, from two reefs separated by 19 km of deep water. We aimed to determine if the frequency of different symbiont genotypes varied with respect to coral host species or geographic location. Our results demonstrate that across the two reefs both coral species contained seven haplotypes of Symbiodinium, all identifiable as clade B and most closely related to type B1. Five of these haplotypes have not been previously described and may be endemic to the Flower Garden Banks. No significant differences in symbiont composition were detected between the two coral species. However, significant quantitative differences were detected between the east and west banks for three background haplotypes comprising 0.1%-10% of the total. The quantitative metabarcoding approach described here can help to sensitively characterize cryptic genetic diversity of Symbiodinium and potentially contribute to the understanding of physiological variations among coral populations.}, }
@article {pmid24882018, year = {2014}, author = {Bettencourt, R and Rodrigues, M and Barros, I and Cerqueira, T and Freitas, C and Costa, V and Pinheiro, M and Egas, C and Santos, RS}, title = {Site-related differences in gene expression and bacterial densities in the mussel Bathymodiolus azoricus from the Menez Gwen and Lucky Strike deep-sea hydrothermal vent sites.}, journal = {Fish &amp; shellfish immunology}, volume = {39}, number = {2}, pages = {343-353}, doi = {10.1016/j.fsi.2014.05.024}, pmid = {24882018}, issn = {1095-9947}, mesh = {Animals ; Atlantic Ocean ; Base Sequence ; Bivalvia/*metabolism/*microbiology ; Computational Biology ; DNA Primers/genetics ; *Ecosystem ; Gene Expression Regulation/*physiology ; Geography ; Gills/microbiology ; *Hydrothermal Vents ; In Situ Hybridization, Fluorescence ; Microbiota/*genetics ; Molecular Sequence Data ; RNA, Ribosomal, 16S/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Transcriptome ; }, abstract = {The deep-sea hydrothermal vent mussel Bathymodiolus azoricus is a symbiont bearing bivalve that is found in great abundance at the Menez Gwen and Lucky Strike hydrothermal vent sites and in close vicinity of the Azores region near the Mid-Atlantic Ridge (MAR). The physiological relationships that vent mussels have developed with their physical and chemical environments are likely to influence global gene expression profiles providing thus the means to investigate distinct biological markers predicting the origin of Bathymodiolus sp. irrespectively of their geographical localization. Differences found at gene expression levels, and between fluorescence in situ hybridization (FISH) and 16S rRNA amplicon sequencing results provided experimental evidence for the distinction of both Menez Gwen and Lucky Strike vent mussel individuals based on bacterial and vent mussel gene expression signatures and on the constitutive distribution and relative abundance of endosymbiotic bacteria within gill tissues. Our results confirmed the presence of methanotroph endosymbionts in Menez Gwen vent mussels whereas Lucky Strike specimens seem to harbor a different bacterial morphotype when a methane monooxygenase gene specific probe was used. No qualitative differences could be visualized between Menez Gwen and Lucky Strike individuals when tested with a sulfur-oxidizing-related probe. Quantitative PCR (qPCR) studies revealed different gene expression profiles in both Menez Gwen and Lucky Strike mussel gill tissues for the immune genes selected. Genes encoding transcription factors presented noticeably low levels of fold expression whether in Menez Gwen or Lucky Strike animals whereas the genes encoding effector molecules appeared to have higher levels expression in gill tissues from Menez Gwen animals. The peptidoglycan recognition molecule encoding gene, PGRP, presented the highest level of transcriptional activity among the genes analyzed in Menez Gwen mussel gill tissues, seconded by carcinolectin and thus denoting the relevance of immune recognition molecules in early stage of the immune responses onset. Genes regarded as encoding molecules involved in signaling pathways were consistently expressed in both Menez Gwen and Lucky Strike mussel gill tissues. Remarkably, the immunity-related GTPase encoding gene demonstrated, in Lucky Strike samples, the highest level of expression among the signaling molecule encoding genes tested when expressions levels were compared between Menez Gwen and Lucky Strike animals. A differential expression analysis of bacterial genes between Menez Gwen and Lucky Strike mussels indicated a clear expression signature in the latter animal gill tissues. The bacterial community structure ensued from the 16S rRNA sequencing analyses pointed at an unpredicted conservation of endosymbiont bacterial loads between Menez Gwen and Lucky Strike samples. Taken together, our results support the hypothesis that B. azoricus exhibits different transcriptional statuses while living in distinct hydrothermal vent sites may result in distinct gene expressions because of physico-chemical and/or symbiont densities differences.}, }
@article {pmid26418854, year = {2014}, author = {Carrasco, P and Pérez-Cobas, AE and van de Pol, C and Baixeras, J and Moya, A and Latorre, A}, title = {Succession of the gut microbiota in the cockroach Blattella germanica.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {17}, number = {2}, pages = {99-109}, doi = {10.2436/20.1501.01.212}, pmid = {26418854}, issn = {1139-6709}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Cockroaches/*microbiology ; Female ; *Gastrointestinal Microbiome ; Gastrointestinal Tract/microbiology ; Male ; Molecular Sequence Data ; Phylogeny ; }, abstract = {The cockroach gut harbors a wide variety of microorganisms that, among other functions, collaborate in digestion and act as a barrier against pathogen colonization. Blattabacterium, a primary endosymbiont, lives in the fat body inside bacteriocytes and plays an important role in nitrogen recycling. Little is known about the mode of acquisition of gut bacteria or their ecological succession throughout the insect life cycle. Here we report on the bacterial taxa isolated from different developmental instars of the cockroach Blattella germanica. The bacterial load in the gut increased two orders of magnitude from the first to the second nymphal stage, coinciding with the incorporation of the majority of bacterial taxa, but remained similar thereafter. Pyrosequencing of the hypervariable regions V1-V3 of the 16S rRNA genes showed that the microbial composition differed significantly between adults and nymphs. Specifically, a succession was observed in which Fusobacterium accumulated with aging, while Bacteroides decreased. Blattabacterium was the only symbiont found in the ootheca, which makes the vertical transmission of gut bacteria an unlikely mode of acquisition. Scanning electron microscopy disclosed a rich bacterial biofilm in third instar nymphs, while filamentous structures were found exclusively in adults.}, }
@article {pmid24874568, year = {2014}, author = {Hosoda, K and Habuchi, M and Suzuki, S and Miyazaki, M and Takikawa, G and Sakurai, T and Kashiwagi, A and Sueyoshi, M and Matsumoto, Y and Kiuchi, A and Mori, K and Yomo, T}, title = {Adaptation of a cyanobacterium to a biochemically rich environment in experimental evolution as an initial step toward a chloroplast-like state.}, journal = {PloS one}, volume = {9}, number = {5}, pages = {e98337}, pmid = {24874568}, issn = {1932-6203}, mesh = {*Adaptation, Biological ; Algorithms ; Autotrophic Processes ; *Biological Evolution ; Chloroplasts/*metabolism ; Cyanobacteria/*physiology ; *Environment ; Genome, Bacterial ; High-Throughput Nucleotide Sequencing ; Models, Theoretical ; }, abstract = {Chloroplasts originated from cyanobacteria through endosymbiosis. The original cyanobacterial endosymbiont evolved to adapt to the biochemically rich intracellular environment of the host cell while maintaining its photosynthetic function; however, no such process has been experimentally demonstrated. Here, we show the adaptation of a model cyanobacterium, Synechocystis sp. PCC 6803, to a biochemically rich environment by experimental evolution. Synechocystis sp. PCC 6803 does not grow in a biochemically rich, chemically defined medium because several amino acids are toxic to the cells at approximately 1 mM. We cultured the cyanobacteria in media with the toxic amino acids at 0.1 mM, then serially transferred the culture, gradually increasing the concentration of the toxic amino acids. The cells evolved to show approximately the same specific growth rate in media with 0 and 1 mM of the toxic amino acid in approximately 84 generations and evolved to grow faster in the media with 1 mM than in the media with 0 mM in approximately 181 generations. We did not detect a statistically significant decrease in the autotrophic growth of the evolved strain in an inorganic medium, indicating the maintenance of the photosynthetic function. Whole-genome resequencing revealed changes in the genes related to the cell membrane and the carboxysome. Moreover, we quantitatively analyzed the evolutionary changes by using simple mathematical models, which evaluated the evolution as an increase in the half-maximal inhibitory concentration (IC50) and estimated quantitative characteristics of the evolutionary process. Our results clearly demonstrate not only the potential of a model cyanobacterium to adapt to a biochemically rich environment without a significant decrease in photosynthetic function but also the properties of its evolutionary process, which sheds light of the evolution of chloroplasts at the initial stage.}, }
@article {pmid24871601, year = {2014}, author = {Valle, LG}, title = {Validation of the trichomycete Paramoebidium chattoni (Amoebidiales, Mesomycetozoea), a common and cosmopolitan black fly endosymbiont.}, journal = {Mycologia}, volume = {106}, number = {3}, pages = {573-579}, doi = {10.3852/13-303}, pmid = {24871601}, issn = {0027-5514}, mesh = {Animals ; Fungi/classification/*isolation &amp; purification/physiology ; Gastrointestinal Tract/microbiology/physiology ; Phylogeny ; Simuliidae/classification/*microbiology/physiology ; *Symbiosis ; }, abstract = {Paramoebidium, along with Amoebidium, constitute the Amoebidiales, which is phylogenetically embedded within the protist clade Ichthyosporea (Mesomycetozoea). However, the order is conventionally included within the trichomycetes, an ecological and polyphyletic group of arthropod-gut endosymbionts. Paramoebidium chattoni (Léger and Duboscq) Duboscq et al. is regarded as nomen nudum because the species was incorrectly published, and its taxonomic situation has never been addressed. Thus, P. chattoni is validated here with a description and neotypification to formalize the species and to guarantee the maintenance and correct use of its name. This common species has a wide geographical range and inhabits the digestive system of aquatic black fly larvae, where it frequently appears together with other gut endosymbionts, including P. curvum.}, }
@article {pmid24871595, year = {2014}, author = {Valle, LG and Rossi, W and Santamaria, S}, title = {Orphella intropus (Kickxellomycotina), a new insect endosymbiont with an unusual perforating holdfast system and other trichomycetes from Italy.}, journal = {Mycologia}, volume = {106}, number = {3}, pages = {589-606}, doi = {10.3852/13-349}, pmid = {24871595}, issn = {0027-5514}, mesh = {Animals ; DNA, Fungal/genetics ; DNA, Ribosomal/genetics ; Fungi/classification/genetics/*isolation &amp; purification/*physiology ; Gastrointestinal Tract/microbiology/physiology ; Insecta/*microbiology/physiology ; Italy ; Molecular Sequence Data ; Phylogeny ; Spores, Fungal/classification/genetics/growth &amp; development/isolation &amp; purification ; *Symbiosis ; }, abstract = {New data about trichomycetes (arthropod gut endosymbionts) from northern Italy (Piedmont [Piemonte] region) are reported, including the description of two new species of Harpellales: Glotzia distorta from mayfly nymphs and Orphella intropus from stonefly nymphs. The latter species is characterized by a cellular bulbous holdfast that perforates the gut lining of its host. Sixteen additional geographical records for Italy are provided, including from the Harpellales, Harpellomyces eccentricus, Graminella bulbosa, Orphella catalaunica, Pennella grassei, Smittium perforatum, Sm. elongatum, Stachylina nana, St. jujuyensis, St penetralis and Tectimyces leptophlebiidarum, and from the Amoebidiales, Paramoebidium chattoni, P. corpulentum, P. curvum, P. ecdyonuridae, P. hamatum and P. inflexum. We provide an emendation of Pennella grassei, a rare, incompletely described and poorly illustrated species that was recovered from Italy nearly 50 y after its last citation from France.}, }
@article {pmid24871104, year = {2015}, author = {Montagna, M and Gómez-Zurita, J and Giorgi, A and Epis, S and Lozzia, G and Bandi, C}, title = {Metamicrobiomics in herbivore beetles of the genus Cryptocephalus (Chrysomelidae): toward the understanding of ecological determinants in insect symbiosis.}, journal = {Insect science}, volume = {22}, number = {3}, pages = {340-352}, doi = {10.1111/1744-7917.12143}, pmid = {24871104}, issn = {1744-7917}, mesh = {Animals ; Bacteria/classification/*genetics ; Coleoptera/*microbiology ; Metagenomics ; Microbiota ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {The Cryptocephalus marginellus (Coleoptera: Chrysomelidae) complex is composed by six species that are supposed to have originated by events of allo- or parapatric speciation. In the present study we investigated the alternative hypotheses that the bacterial communities associated with six populations of this species complex are shaped by environmental factors, or reflect the proposed pattern of speciation. The microbiota associated with the six populations, from five species of the complex, have been characterized through 16S rRNA pyrotag sequencing. Based on a 97% sequence similarity threshold, data were clustered into 381 OTUs, which were analyzed using a variety of diversity indices. The microbiota of C. acquitanus and C. marginellus (Calanques) were the most diverse (over 100 OTUs), while that from C. zoiai yielded less bacterial diversity (45 OTUs). Taxonomic assignment revealed Proteobacteria, Tenericutes and Firmicutes as the dominant components of these beetles' microbiota. The most abundant genera were Ralstonia, Sphingomonas, Rickettsia, and Pseudomonas. Different strains of Rickettsia were detected in C. eridani and C. renatae. The analysis of β-diversity revealed high OTU turnover among the populations of C. marginellus complex, with only few shared species. Hierarchical clustering taking into account relative abundances of OTUs does not match the phylogeny of the beetles, therefore we hypothesize that factors other than phylogenetic constraints play a role in shaping the insects' microbiota. Environmental factors that could potentially affect the composition of bacterial communities were tested by fitting them on the results of a multi-dimensional scaling analysis. No significant correlations were observed towards the geographic distances or the host plants, while the composition of the microbiota appeared associated with altitude. The metabolic profiles of the microbiotas associated with each population were inferred from bacterial taxonomy, and interestingly, the obtained clustering pattern was consistent with the host phylogeny.}, }
@article {pmid24867807, year = {2014}, author = {Bejarano, A and Ramírez-Bahena, MH and Velázquez, E and Peix, A}, title = {Vigna unguiculata is nodulated in Spain by endosymbionts of Genisteae legumes and by a new symbiovar (vignae) of the genus Bradyrhizobium.}, journal = {Systematic and applied microbiology}, volume = {37}, number = {7}, pages = {533-540}, doi = {10.1016/j.syapm.2014.04.003}, pmid = {24867807}, issn = {1618-0984}, mesh = {Bradyrhizobium/*classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Plant/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Fabaceae/*microbiology ; Molecular Sequence Data ; Phylogeny ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; Spain ; }, abstract = {Vigna unguiculata was introduced into Europe from its distribution centre in Africa, and it is currently being cultivated in Mediterranean regions with adequate edapho-climatic conditions where the slow growing rhizobia nodulating this legume have not yet been studied. Previous studies based on rrs gene and ITS region analyses have shown that Bradyrhizobium yuanmingense and B. elkanii nodulated V. unguiculata in Africa, but these two species were not found in this study. Using the same phylogenetic markers it was shown that V. unguiculata, a legume from the tribe Phaseolae, was nodulated in Spain by two species of group I, B. cytisi and B. canariense, which are common endosymbionts of Genisteae in both Europe and Africa. These species have not been found to date in V. unguiculata nodules in its African distribution centres. All strains from Bradyrhizobium group I isolated in Spain belonged to the symbiovar genistearum, which is found at present only in Genisteae legumes in both Africa and Europe. V. unguiculata was also nodulated in Spain by a strain from Bradyrhizobium group II that belonged to a novel symbiovar (vignae). Some African V. unguiculata-nodulating strains also belonged to this proposed new symbiovar.}, }
@article {pmid24854223, year = {2014}, author = {Indest, KJ and Eaton, HL and Jung, CM and Lounds, CB}, title = {Biotransformation of explosives by Reticulitermes flavipes--associated termite Endosymbionts.}, journal = {Journal of molecular microbiology and biotechnology}, volume = {24}, number = {2}, pages = {114-119}, doi = {10.1159/000361027}, pmid = {24854223}, issn = {1660-2412}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification/*metabolism ; Biotransformation ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Explosive Agents/*metabolism ; Isoptera/*microbiology ; Molecular Sequence Data ; Nitro Compounds/metabolism ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Triazines/metabolism ; Triazoles/metabolism ; Trinitrotoluene/metabolism ; }, abstract = {BACKGROUND/AIMS: Termites have an important role in the carbon and nitrogen cycles despite their reputation as destructive pests. With the assistance of microbial endosymbionts, termites are responsible for the conversion of complex biopolymers into simple carbon substrates. Termites also rely on endosymbionts for fixing and recycling nitrogen. As a result, we hypothesize that termite bacterial endosymbionts are a novel source of metabolic pathways for the transformation of nitrogen-rich compounds like explosives.<br><br>METHODS: Explosives transformation capability of termite (Reticulitermes flavipes)-derived endosymbionts was determined in media containing the chemical constituents nitrotriazolone (NTO) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) that comprise new insensitive explosive formulations. Media dosed with 40 &#xb5;g/ml of explosive was inoculated with surface-sterilized, macerated termites. Bacterial isolates capable of explosives transformation were characterized by 16S rRNA sequencing.<br><br>RESULTS: Termite-derived enrichment cultures demonstrated degradation activity towards the explosives NTO, RDX, as well as the legacy explosive 2,4,6-trinitrotoluene (TNT). Three isolates with high similarity to the Enterobacteriaceae(Enterobacter, Klebsiella) were able to transform TNT and NTO within 2 days, while isolates with high similarity to Serratia marcescens and Lactococcus lactis were able to transform RDX.<br><br>CONCLUSION: Termite endosymbionts harbor a range of metabolic activities and possess unique abilities to transform nitrogen-rich explosives.}, }
@article {pmid24850893, year = {2014}, author = {Vanthournout, B and Deswarte, K and Hammad, H and Bilde, T and Lambrecht, B and Hendrickx, F}, title = {Flow cytometric sexing of spider sperm reveals an equal sperm production ratio in a female-biased species.}, journal = {Biology letters}, volume = {10}, number = {5}, pages = {20140159}, pmid = {24850893}, issn = {1744-957X}, support = {282163/ERC_/European Research Council/International ; }, mesh = {Animals ; Female ; Flow Cytometry ; Male ; *Sex Ratio ; Spermatogenesis ; *Spermatozoa ; *Spiders ; }, abstract = {Producing equal amounts of male and female offspring has long been considered an evolutionarily stable strategy. Nevertheless, exceptions to this general rule (i.e. male and female biases) are documented in many taxa, making sex allocation an important domain in current evolutionary biology research. Pinpointing the underlying mechanism of sex ratio bias is challenging owing to the multitude of potential sex ratio-biasing factors. In the dwarf spider, Oedothorax gibbosus, infection with the bacterial endosymbiont Wolbachia results in a female bias. However, pedigree analysis reveals that other factors influence sex ratio variation. In this paper, we investigate whether this additional variation can be explained by the unequal production of male- and female-determining sperm cells during sperm production. Using flow cytometry, we show that males produce equal amounts of male- and female-determining sperm cells; thus bias in sperm production does not contribute to the sex ratio bias observed in this species. This demonstrates that other factors such as parental genes suppressing endosymbiont effects and cryptic female choice might play a role in sex allocation in this species.}, }
@article {pmid24825743, year = {2014}, author = {Harrison, E and MacLean, RC and Koufopanou, V and Burt, A}, title = {Sex drives intracellular conflict in yeast.}, journal = {Journal of evolutionary biology}, volume = {27}, number = {8}, pages = {1757-1763}, doi = {10.1111/jeb.12408}, pmid = {24825743}, issn = {1420-9101}, mesh = {Analysis of Variance ; *Biological Evolution ; DNA Primers/genetics ; Meiosis/*physiology ; Mitochondria/genetics/*physiology ; Models, Genetic ; Plasmids/genetics/*physiology ; Polymerase Chain Reaction ; Reproduction/genetics ; Reproduction, Asexual/genetics ; Saccharomyces cerevisiae/*genetics ; Selection, Genetic ; *Sex ; }, abstract = {Theory predicts that sex can drive the evolution of conflict within the cell. During asexual reproduction, genetic material within the cell is inherited as a single unit, selecting for cooperation both within the genome as well as between the extra-genomic elements within the cell (e.g. plasmids and endosymbionts). Under sexual reproduction, this unity is broken down as parental genomes are distributed between meiotic progeny. Genetic elements able to transmit to more than 50% of meiotic progeny have a transmission advantage over the rest of the genome and are able to spread, even where they reduce the fitness of the individual as a whole. Sexual reproduction is therefore expected to drive the evolution of selfish genetic elements (SGEs). Here, we directly test this hypothesis by studying the evolution of two independent SGEs, the 2-μm plasmid and selfish mitochondria, in populations of Saccharomyces cerevisiae. Following 22 rounds of sexual reproduction, 2-μm copy number increased by approximately 13.2 (±5.6) copies per cell, whereas in asexual populations copy number decreased by approximately 5.1 (±1.5) copies per cell. Given that the burden imposed by this parasite increases with copy number, these results support the idea that sex drives the evolution of increased SGE virulence. Moreover, we found that mitochondria that are respiratory-deficient rapidly invaded sexual but not asexual populations, demonstrating that frequent outcrossed sex can drive the de novo evolution of genetic parasites. Our study highlights the genomic perils of sex and suggests that SGEs may play a key role in driving major evolutionary transitions, such as uniparental inheritance.}, }
@article {pmid24821918, year = {2014}, author = {Burt, A}, title = {Heritable strategies for controlling insect vectors of disease.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {369}, number = {1645}, pages = {20130432}, pmid = {24821918}, issn = {1471-2970}, mesh = {Animals ; *Biological Control Agents ; Culicidae/genetics/*microbiology/pathogenicity ; Cytoplasm/microbiology ; Dengue/prevention &amp; control ; Humans ; Insect Vectors/genetics/*microbiology ; Longevity ; Malaria/prevention &amp; control ; Mosquito Control/*methods/*trends ; Wolbachia/*genetics ; }, abstract = {Mosquito-borne diseases are causing a substantial burden of mortality, morbidity and economic loss in many parts of the world, despite current control efforts, and new complementary approaches to controlling these diseases are needed. One promising class of new interventions under development involves the heritable modification of the mosquito by insertion of novel genes into the nucleus or of Wolbachia endosymbionts into the cytoplasm. Once released into a target population, these modifications can act to reduce one or more components of the mosquito population's vectorial capacity (e.g. the number of female mosquitoes, their longevity or their ability to support development and transmission of the pathogen). Some of the modifications under development are designed to be self-limiting, in that they will tend to disappear over time in the absence of recurrent releases (and hence are similar to the sterile insect technique, SIT), whereas other modifications are designed to be self-sustaining, spreading through populations even after releases stop (and hence are similar to traditional biological control). Several successful field trials have now been performed with Aedes mosquitoes, and such trials are helping to define the appropriate developmental pathway for this new class of intervention.}, }
@article {pmid24820937, year = {2014}, author = {Pasaribu, B and Lin, IP and Tzen, JT and Jauh, GY and Fan, TY and Ju, YM and Cheng, JO and Chen, CS and Jiang, PL}, title = {SLDP: a novel protein related to caleosin is associated with the endosymbiotic Symbiodinium lipid droplets from Euphyllia glabrescens.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {16}, number = {5}, pages = {560-571}, pmid = {24820937}, issn = {1436-2236}, mesh = {Animals ; Anthozoa/*microbiology ; Blotting, Western ; Calcium-Binding Proteins/*genetics/metabolism ; Dinoflagellida/*genetics/metabolism ; Gas Chromatography-Mass Spectrometry ; Image Processing, Computer-Assisted ; Lipid Droplets/*metabolism ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Plant Proteins/*genetics/metabolism ; *Symbiosis ; Taiwan ; }, abstract = {Intracellular lipid droplets (LDs) have been proposed to play a key role in the mutualistic endosymbiosis between reef-building corals and the dinoflagellate endosymbiont Symbiodinium spp. This study investigates and identifies LD proteins in Symbiodinium from Euphyllia glabrescens. Discontinuous Percoll gradient centrifugation was used to separate Symbiodinium cells from E. glabrescens tentacles. Furthermore, staining with a fluorescent probe, Nile red, indicated that lipids accumulated in that freshly isolated Symbiodinium cells and lipid analyses further showed polyunsaturated fatty acids (PUFA) was abundant. The stable LDs were purified from endosymbiotic Symbiodinium cells. The structural integrity of the Symbiodinium LDs was maintained via electronegative repulsion and steric hindrance possibly provided by their surface proteins. Protein extracts from the purified LDs revealed a major protein band with a molecular weight of 20 kDa, which was termed Symbiodinium lipid droplet protein (SLDP). Interestingly, immunological cross-recognition analysis revealed that SLDP was detected strongly by the anti-sesame and anti-cycad caleosin antibodies. It was suggested that the stable Symbiodinium LDs were sheltered by this unique structural protein and was suggested that SLDP might be homologous to caleosin to a certain extent.}, }
@article {pmid24814785, year = {2014}, author = {Aksoy, E and Telleria, EL and Echodu, R and Wu, Y and Okedi, LM and Weiss, BL and Aksoy, S and Caccone, A}, title = {Analysis of multiple tsetse fly populations in Uganda reveals limited diversity and species-specific gut microbiota.}, journal = {Applied and environmental microbiology}, volume = {80}, number = {14}, pages = {4301-4312}, pmid = {24814785}, issn = {1098-5336}, support = {R03 TW008755/TW/FIC NIH HHS/United States ; D43 TW007391/TW/FIC NIH HHS/United States ; R03TW008755/TW/FIC NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; AI068932/AI/NIAID NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cloning, Molecular ; DNA, Bacterial/genetics ; Gastrointestinal Tract/*microbiology ; Gene Library ; *Genetic Variation ; High-Throughput Nucleotide Sequencing ; *Microbiota ; Phylogeography ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; Tsetse Flies/*classification/*microbiology ; Uganda ; Wigglesworthia/genetics/isolation &amp; purification ; }, abstract = {The invertebrate microbiome contributes to multiple aspects of host physiology, including nutrient supplementation and immune maturation processes. We identified and compared gut microbial abundance and diversity in natural tsetse flies from Uganda using five genetically distinct populations of Glossina fuscipes fuscipes and multiple tsetse species (Glossina morsitans morsitans, G. f. fuscipes, and Glossina pallidipes) that occur in sympatry in one location. We used multiple approaches, including deep sequencing of the V4 hypervariable region of the 16S rRNA gene, 16S rRNA gene clone libraries, and bacterium-specific quantitative PCR (qPCR), to investigate the levels and patterns of gut microbial diversity from a total of 151 individuals. Our results show extremely limited diversity in field flies of different tsetse species. The obligate endosymbiont Wigglesworthia dominated all samples (>99%), but we also observed wide prevalence of low-density Sodalis (tsetse's commensal endosymbiont) infections (<0.05%). There were also several individuals (22%) with high Sodalis density, which also carried coinfections with Serratia. Albeit in low density, we noted differences in microbiota composition among the genetically distinct G. f. fuscipes flies and between different sympatric species. Interestingly, Wigglesworthia density varied in different species (10(4) to 10(6) normalized genomes), with G. f. fuscipes having the highest levels. We describe the factors that may be responsible for the reduced diversity of tsetse's gut microbiota compared to those of other insects. Additionally, we discuss the implications of Wigglesworthia and Sodalis density variations as they relate to trypanosome transmission dynamics and vector competence variations associated with different tsetse species.}, }
@article {pmid24813786, year = {2014}, author = {Kramer, L and Genchi, C}, title = {Where are we with Wolbachia and doxycycline: an in-depth review of the current state of our knowledge.}, journal = {Veterinary parasitology}, volume = {206}, number = {1-2}, pages = {1-4}, doi = {10.1016/j.vetpar.2014.03.028}, pmid = {24813786}, issn = {1873-2550}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Antinematodal Agents/pharmacology/therapeutic use ; Dirofilaria immitis/drug effects/*microbiology ; Dirofilariasis/*drug therapy/*microbiology/transmission ; Doxycycline/pharmacology/*therapeutic use ; Drug Synergism ; Humans ; Ivermectin/therapeutic use ; Wolbachia/immunology/*physiology ; }, abstract = {Dirofilaria immitis, the cause of canine and feline heartworm disease, was the first filarial nematode described to harbour the bacterial endosymbiont Wolbachia. This ground-breaking discovery has led to intense research aimed at unravelling the nature of the endosymbiotic relationship; genomic studies have revealed how the bacteria may interact with the parasite and help explain why each is so dependent on the other. Analysis of the immune response to these bacteria may elucidate the mechanisms through which filarial parasites are able to survive for long periods of time in otherwise immune-competent hosts. Finally, studies aimed at the removal of the bacteria using specific antibiotic treatment in infected hosts is leading to the development of novel approaches for interrupting the transmission cycle and for the treatment and control of heartworm disease.}, }
@article {pmid24812591, year = {2014}, author = {Hou, Q and He, J and Yu, J and Ye, Y and Zhou, D and Sun, Y and Zhang, D and Ma, L and Shen, B and Zhu, C}, title = {A case of horizontal gene transfer from Wolbachia to Aedes albopictus C6/36 cell line.}, journal = {Mobile genetic elements}, volume = {4}, number = {1}, pages = {e28914}, pmid = {24812591}, issn = {2159-2543}, support = {R01 AI075746/AI/NIAID NIH HHS/United States ; }, abstract = {Horizontal gene transfer plays an essential role in evolution and ecological adaptation, yet this phenomenon has remained controversial, particularly where it occurs between prokaryotes and eukaryotes. There are a handful of reported examples of horizontal gene transfer occurring between prokaryotes and eukaryotes in the literature, with most of these documented cases pertaining to invertebrates and endosymbionts. However, the vast majority of these horizontally transferred genes were either eventually excluded or rapidly became nonfunctional in the recipient genome. In this study, we report the discovery of a horizontal gene transfer from the endosymbiont Wolbachia in the C6/36 cell line derived from the mosquito Aedes albopictus. Moreover, we report that this horizontally transferred gene displayed high transcription level. This finding and the results of further experimentation strongly suggest this gene is functional and has been expressed and translated into a protein in the mosquito host cells.}, }
@article {pmid24806619, year = {2014}, author = {Famah Sourassou, N and Hanna, R and Breeuwer, JA and Negloh, K and de Moraes, GJ and Sabelis, MW}, title = {The endosymbionts Wolbachia and Cardinium and their effects in three populations of the predatory mite Neoseiulus paspalivorus.}, journal = {Experimental &amp; applied acarology}, volume = {64}, number = {2}, pages = {207-221}, pmid = {24806619}, issn = {1572-9702}, mesh = {Animals ; Anti-Bacterial Agents ; Benin ; Brazil ; DNA, Mitochondrial/genetics ; Female ; Genetic Variation ; Ghana ; Male ; Mites/genetics/*microbiology/*physiology ; Phylogeny ; Predatory Behavior ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Wolbachia/drug effects/*isolation &amp; purification ; }, abstract = {Whereas endosymbiont-induced incompatibility is known to occur in various arthropod taxa, such as spider mites, insects and isopods, it has been rarely reported in plant-inhabiting predatory mites (Acari: Phytoseiidae). Recent cross-breeding studies with the phytoseiid mite Neoseiulus paspalivorus De Leon revealed a complete post-mating reproductive isolation between specimens collected from three geographic origins-Northeast Brazil (South America), Benin and Ghana (West Africa)-even though they are morphologically similar. We carried out a study to assess to what extent these populations exhibit genetic differences and whether endosymbionts are involved in the incompatibility. First, we used the mitochondrial cytochrome oxidase I (COI) gene to assess genetic diversity among the three populations. Second, we used a PCR-based method to check for the presence of Wolbachia and/or Cardinium in these populations, and we determined their phylogenetic relationships using specific primers for Wolbachia and Cardinium 16S rDNA genes. Third, we also conducted a test using an antibiotic (tetracycline) in an attempt to eliminate the symbionts and evaluate their effects on the reproductive compatibility of their host. Based on the DNA sequences of their COI genes, specimens of the three populations appear to be genetically similar. However, the 16S rDNA gene sequences of their associated endosymbionts differed among the three populations: the Benin and Brazil populations harbour different strains of Wolbachia symbionts, whereas the Ghana population harbours Cardinium symbionts. In response to antibiotic treatment females of each of the three populations became incompatible with untreated males of their own population, similar to that observed in crossings between females from one geographic population and males from another. Compatibility was restored in crosses involving uninfected Brazil females and uninfected Benin males, whereas the reciprocal crosses remained incompatible. Cardinium symbionts seem to be essential for oviposition in the Ghana population. It is concluded that their associated bacterial symbionts are the cause of the post-mating reproductive isolation previously observed among the three geographic populations. This insight is relevant to biological control of coconut mites for which N. paspalivorus is an effective predator, because introducing one geographic strain into the population of another (e.g. in field releases or mass cultures) may cause population growth depression.}, }
@article {pmid24797695, year = {2014}, author = {Turley, AP and Smallegange, RC and Takken, W and Zalucki, MP and O'Neill, SL and McGraw, EA}, title = {Wolbachia infection does not alter attraction of the mosquito Aedes (Stegomyia) aegypti to human odours.}, journal = {Medical and veterinary entomology}, volume = {28}, number = {4}, pages = {457-460}, doi = {10.1111/mve.12063}, pmid = {24797695}, issn = {1365-2915}, mesh = {Aedes/*microbiology ; Aging ; Animals ; Feeding Behavior/*physiology ; Female ; Humans ; *Odorants ; Wolbachia/*isolation &amp; purification ; }, abstract = {The insect endosymbiont Wolbachia pipientis (Rickettsiales: Rickettsiaceae) is undergoing field trials around the world to determine if it can reduce transmission of dengue virus from the mosquito Stegomyia aegypti to humans. Two different Wolbachia strains have been released to date. The primary effect of the wMel strain is pathogen protection whereby infection with the symbiont limits replication of dengue virus inside the mosquito. A second strain, wMelPop, induces pathogen protection, reduces the adult mosquito lifespan and decreases blood feeding success in mosquitoes after 15 days of age. Here we test whether Wolbachia infection affects mosquito attraction to host odours in adults aged 5 and 15 days. We found no evidence of reduced odour attraction of mosquitoes, even for those infected with the more virulent wMelPop. This bodes well for fitness and competitiveness in the field given that the mosquitoes must find hosts to reproduce for the biocontrol method to succeed.}, }
@article {pmid24797097, year = {2014}, author = {Mathew, M and Lopanik, NB}, title = {Host differentially expressed genes during association with its defensive endosymbiont.}, journal = {The Biological bulletin}, volume = {226}, number = {2}, pages = {152-163}, doi = {10.1086/BBLv226n2p152}, pmid = {24797097}, issn = {1939-8697}, mesh = {Actins/genetics ; Animals ; Base Sequence ; Bryostatins/genetics/metabolism ; Bryozoa/*genetics/metabolism ; Gammaproteobacteria/drug effects/genetics/*physiology ; Gene Expression ; Molecular Sequence Data ; Polymerase Chain Reaction ; Symbiosis/*genetics ; }, abstract = {Mutualism, a beneficial relationship between two species, often requires intimate interaction between the host and symbiont to establish and maintain the partnership. The colonial marine bryozoan Bugula neritina harbors an as yet uncultured endosymbiont, "Candidatus Endobugula sertula," throughout its life stages. The bacterial symbiont is the putative source of bioactive complex polyketide metabolites, the bryostatins, which chemically defend B. neritina larvae from predation. Despite the presence of "Ca. Endobugula sertula" in all life stages of the host, deterrent bryostatins appear to be concentrated in reproductive portions of the host colony, suggesting an interaction between the two partners to coordinate production and distribution of the metabolites within the colony. In this study, we identified host genes that were differentially expressed in control colonies and in colonies cured of the symbiont. Genes that code for products similar to glycosyl hydrolase family 9 and family 20 proteins, actin, and a Rho-GDP dissociation inhibitor were significantly downregulated (more than twice) in antibiotic-cured non-reproductive zooids compared to control symbiotic ones. Differential expression of these genes leads us to hypothesize that the host B. neritina may regulate the distribution of the symbiont within the colony via mechanisms of biofilm degradation and actin rearrangement, and consequently, influences bryostatin localization to bestow symbiont-associated protection to larvae developing in the reproductive zooids.}, }
@article {pmid24795089, year = {2014}, author = {Li, B and Lopes, JS and Foster, PG and Embley, TM and Cox, CJ}, title = {Compositional biases among synonymous substitutions cause conflict between gene and protein trees for plastid origins.}, journal = {Molecular biology and evolution}, volume = {31}, number = {7}, pages = {1697-1709}, pmid = {24795089}, issn = {1537-1719}, mesh = {Amino Acids/genetics ; Bias ; Codon/genetics ; Cyanobacteria/*classification/*genetics ; Evolution, Molecular ; Genome, Bacterial ; Genome, Plastid ; Phylogeny ; Plastids/*genetics ; }, abstract = {Archaeplastida (=Kingdom Plantae) are primary plastid-bearing organisms that evolved via the endosymbiotic association of a heterotrophic eukaryote host cell and a cyanobacterial endosymbiont approximately 1,400 Ma. Here, we present analyses of cyanobacterial and plastid genomes that show strongly conflicting phylogenies based on 75 plastid (or nuclear plastid-targeted) protein-coding genes and their direct translations to proteins. The conflict between genes and proteins is largely robust to the use of sophisticated data- and tree-heterogeneous composition models. However, by using nucleotide ambiguity codes to eliminate synonymous substitutions due to codon-degeneracy, we identify a composition bias, and dependent codon-usage bias, resulting from synonymous substitutions at all third codon positions and first codon positions of leucine and arginine, as the main cause for the conflicting phylogenetic signals. We argue that the protein-coding gene data analyses are likely misleading due to artifacts induced by convergent composition biases at first codon positions of leucine and arginine and at all third codon positions. Our analyses corroborate previous studies based on gene sequence analysis that suggest Cyanobacteria evolved by the early paraphyletic splitting of Gloeobacter and a specific Synechococcus strain (JA33Ab), with all other remaining cyanobacterial groups, including both unicellular and filamentous species, forming the sister-group to the Archaeplastida lineage. In addition, our analyses using better-fitting models suggest (but without statistically strong support) an early divergence of Glaucophyta within Archaeplastida, with the Rhodophyta (red algae), and Viridiplantae (green algae and land plants) forming a separate lineage.}, }
@article {pmid24789572, year = {2015}, author = {Hélène, D and Rémy, B and Nathalie, B and Anne-Laure, G and Traoré, RS and Jean-Michel, L and Bernard, R}, title = {Species and endosymbiont diversity of Bemisia tabaci (Homoptera: Aleyrodidae) on vegetable crops in Senegal.}, journal = {Insect science}, volume = {22}, number = {3}, pages = {386-398}, doi = {10.1111/1744-7917.12134}, pmid = {24789572}, issn = {1744-7917}, mesh = {Animals ; Bacteria/*genetics ; Biodiversity ; Crops, Agricultural ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Female ; Hemiptera/genetics/*microbiology ; Microsatellite Repeats ; Senegal ; Symbiosis ; Vegetables/parasitology ; }, abstract = {Bemisia tabaci-transmitted geminiviruses are one of the major threats on cassava and vegetable crops in Africa. However, to date, few studies are available on the diversity of B. tabaci and their associated endosymbionts in Africa. More than 28 species have been described in the complex of B. tabaci cryptic species; among them, 2 are invasive pests worldwide: MED and MEAM1. In order to assess the species diversity of B. tabaci in vegetable crops in Senegal, several samplings in different localities, hosts and seasons were collected and analyzed with nuclear (microsatellite) and mitochondrial (COI) markers. The bacterial endosymbiont community was also studied for each sample. Two species were detected: MED Q1 and MEAM1 B. Patterns of MED Q1 (dominance on most of the samples and sites, highest nuclear and mitochondrial diversity and broader secondary endosymbiont community: Hamiltonella, Cardinium, Wolbachia and Rickettsia), point toward a predominant resident begomovirus vector group for MED Q1 on market gardening crops. Furthermore, the lower prevalence of the second species MEAM1 B, its lower nuclear and mitochondrial diversity and a narrower secondary endosymbiont community (Hamiltonella/Rickettsia), indicate that this genetic group is exotic and results from a recent invasion in this area.}, }
@article {pmid24788211, year = {2014}, author = {Shan, HW and Lu, YH and Bing, XL and Liu, SS and Liu, YQ}, title = {Differential responses of the whitefly Bemisia tabaci symbionts to unfavorable low and high temperatures.}, journal = {Microbial ecology}, volume = {68}, number = {3}, pages = {472-482}, pmid = {24788211}, issn = {1432-184X}, mesh = {Animals ; Enterobacteriaceae/genetics/*physiology ; Female ; Hemiptera/*microbiology/*physiology ; Male ; Rickettsia/genetics/*physiology ; Symbiosis ; *Temperature ; }, abstract = {The whitefly Bemisia tabaci complex contains many cryptic species, of which the Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) are notorious invasive pests. In our field-collected whitefly samples, MEAM1 harbors an obligate primary symbiont "Candidatus Portiera aleyrodidarum" and two secondary symbionts, "Candidatus Hamiltonella defensa" and Rickettsia sp., whereas MED has only "Ca. Portiera aleyrodidarum" and "Ca. Hamiltonella defensa." Both "Ca. Portiera aleyrodidarum" and "Ca. Hamiltonella defensa" are intracellular endosymbionts residing in the bacteriomes, whereas Rickettsia sp. has a scattered distribution throughout the host body cavity. We examined responses of these symbionts to adverse temperatures as well as survival of the host insects. After cold treatment at 5 or 10 °C or heat treatment at 35 or 40 °C for 24 h, respectively, the infection rates of all symbionts were not significantly decreased based on diagnosis PCR. However, quantitative PCR assays indicated significant reduction of "Ca. Hamiltonella defensa" at 40 °C, and the reduction became greater as the duration increased. Compared with "Ca. Hamiltonella defensa," "Ca. Portiera aleyrodidarum" was initially less affected in the first day but then showed more rapid reduction at days 3-5. The density of Rickettsia sp. fluctuated but was not reduced significantly at 40 °C. Meanwhile, the mortality rates of the host whiteflies elevated rapidly as the duration of exposure to heat treatment increased. The differential responses of various symbionts to adverse temperatures imply complex interactions among the symbionts inside the same host insect and highlight the importance of taking the whole bacterial community into account in studies of symbioses.}, }
@article {pmid24787986, year = {2014}, author = {Zhong, Y and Li, ZX}, title = {Bidirectional cytoplasmic incompatibility induced by cross-order transfection of Wolbachia: implications for control of the host population.}, journal = {Microbial ecology}, volume = {68}, number = {3}, pages = {463-471}, pmid = {24787986}, issn = {1432-184X}, mesh = {Animals ; Crosses, Genetic ; Cytoplasm/*microbiology ; DNA, Bacterial/genetics ; Female ; Fertility ; Hemiptera/*microbiology ; Male ; Pest Control, Biological ; Phenotype ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; Wasps/*microbiology ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {Wolbachia are widespread endosymbionts in arthropods and some nematodes. This genus of bacteria is known to manipulate host reproduction by inducing cytoplasmic incompatibility (CI). This important phenotype is implicated in the control of host populations since Wolbachia can suppress host populations through the induction of CI in a way similar to the sterile insect technique. Here, we identified a candidate CI-inducing Wolbachia strain from the parasitic wasp Scleroderma guani (wSguBJ) by sequencing and phylogenetic analysis. This Wolbachia strain was then isolated, purified, and artificially transfected into the new whitefly host Bemisia tabaci through nymphal microinjection. Infection frequency monitoring by molecular detection showed that 60-80 % of the offspring from transfected whitefly populations was infected with wSguBJ six generations after the transfer. Laboratory rearing experiments indicated that the artificial transfection caused no significant difference in the numbers of offspring between the transfected and naturally infected populations and had no significant detrimental effects on the development of transfected males, although the development of transfected females was delayed. Reciprocal crossings revealed that bidirectional CI was induced between the transfected and naturally infected whiteflies. These data indicated that the cross-order transfer of the heterologous Wolbachia strain by nymphal microinjection was successful. Mass release of the transfected males that could stably carry the heterologous Wolbachia without significant compromise of fecundity/development may provide an alternative approach to control of host populations.}, }
@article {pmid24782078, year = {2014}, author = {Baxter, L and Brain, R and Rodriguez-Gil, JL and Hosmer, A and Solomon, K and Hanson, M}, title = {Response of the green alga Oophila sp., a salamander endosymbiont, to a PSII-inhibitor under laboratory conditions.}, journal = {Environmental toxicology and chemistry}, volume = {33}, number = {8}, pages = {1858-1864}, doi = {10.1002/etc.2629}, pmid = {24782078}, issn = {1552-8618}, mesh = {*Ambystoma/growth &amp; development ; Animals ; Atrazine/toxicity ; Chlorophyta/*drug effects/physiology ; Ecotoxicology/*methods ; Enzyme Inhibitors/*toxicity ; Herbicides/toxicity ; *Laboratories ; Ovum/growth &amp; development ; Photosystem II Protein Complex/*antagonists &amp; inhibitors ; *Symbiosis ; Water Pollutants, Chemical/toxicity ; }, abstract = {In a rare example of autotroph-vertebrate endosymbiosis, eggs of the yellow-spotted salamander (Ambystoma maculatum) are colonized by a green alga (Oophila sp.) that significantly enhances salamander development. Previous studies have demonstrated the potential for impacts to the salamander embryo when growth of the algae is impaired by exposure to herbicides. To further investigate this relationship, the authors characterized the response of the symbiotic algae (Oophila sp.) alone to the photosystem II (PSII) inhibitor atrazine under controlled laboratory conditions. After extraction of the alga from A. maculatum eggs and optimization of culturing conditions, 4 toxicity assays (96 h each) were conducted. Recovery of the algal population was also assessed after a further 96 h in untreated media. Average median effective concentration (EC50) values of 123 µg L(-1) (PSII yield), 169 µg L(-1) (optical density), and 299 µg L(-1) (growth rate) were obtained after the 96-h exposure. Full recovery of exposed algal populations after 96 h in untreated media was observed for all endpoints, except for optical density at the greatest concentration tested (300 µg L(-1)). Our results show that, under laboratory conditions, Oophila sp. is generally less sensitive to atrazine than standard test species. Although conditions of growth in standard toxicity tests are not identical to those in the natural environment, these results provide an understanding of the tolerance of this alga to PSII inhibitors as compared with other species.}, }
@article {pmid24781809, year = {2014}, author = {Ma, WJ and Pannebakker, BA and Beukeboom, LW and Schwander, T and van de Zande, L}, title = {Genetics of decayed sexual traits in a parasitoid wasp with endosymbiont-induced asexuality.}, journal = {Heredity}, volume = {113}, number = {5}, pages = {424-431}, pmid = {24781809}, issn = {1365-2540}, mesh = {Animals ; Crosses, Genetic ; Female ; Genes, Recessive ; Male ; Reproduction, Asexual/*genetics ; Sex Ratio ; *Sexual Behavior, Animal ; Wasps/*genetics/*microbiology ; Wolbachia ; }, abstract = {Trait decay may occur when selective pressures shift, owing to changes in environment or life style, rendering formerly adaptive traits non-functional or even maladaptive. It remains largely unknown if such decay would stem from multiple mutations with small effects or rather involve few loci with major phenotypic effects. Here, we investigate the decay of female sexual traits, and the genetic causes thereof, in a transition from haplodiploid sexual reproduction to endosymbiont-induced asexual reproduction in the parasitoid wasp Asobara japonica. We take advantage of the fact that asexual females cured of their endosymbionts produce sons instead of daughters, and that these sons can be crossed with sexual females. By combining behavioral experiments with crosses designed to introgress alleles from the asexual into the sexual genome, we found that sexual attractiveness, mating, egg fertilization and plastic adjustment of offspring sex ratio (in response to variation in local mate competition) are decayed in asexual A. japonica females. Furthermore, introgression experiments revealed that the propensity for cured asexual females to produce only sons (because of decayed sexual attractiveness, mating behavior and/or egg fertilization) is likely caused by recessive genetic effects at a single locus. Recessive effects were also found to cause decay of plastic sex-ratio adjustment under variable levels of local mate competition. Our results suggest that few recessive mutations drive decay of female sexual traits, at least in asexual species deriving from haplodiploid sexual ancestors.}, }
@article {pmid24772084, year = {2014}, author = {Kosmidis, S and Missirlis, F and Botella, JA and Schneuwly, S and Rouault, TA and Skoulakis, EM}, title = {Behavioral decline and premature lethality upon pan-neuronal ferritin overexpression in Drosophila infected with a virulent form of Wolbachia.}, journal = {Frontiers in pharmacology}, volume = {5}, number = {}, pages = {66}, pmid = {24772084}, issn = {1663-9812}, abstract = {Iron is required for organismal growth. Therefore, limiting iron availability may be a key part of the host's innate immune response to various pathogens, for example, in Drosophila infected with Zygomycetes. One way the host can transiently reduce iron bioavailability is by ferritin overexpression. To study the effects of neuronal-specific ferritin overexpression on survival and neurodegeneration we generated flies simultaneously over-expressing transgenes for both ferritin subunits in all neurons. We used two independent recombinant chromosomes bearing UAS-Fer1HCH, UAS-Fer2LCH transgenes and obtained qualitatively different levels of late-onset behavioral and lifespan declines. We subsequently discovered that one parental strain had been infected with a virulent form of the bacterial endosymbiont Wolbachia, causing widespread neuronal apoptosis and premature death. This phenotype was exacerbated by ferritin overexpression and was curable by antibiotic treatment. Neuronal ferritin overexpression in uninfected flies did not cause evident neurodegeneration but resulted in a late-onset behavioral decline, as previously reported for ferritin overexpression in glia. The results suggest that ferritin overexpression in the central nervous system of flies is tolerated well in young individuals with adverse manifestations appearing only late in life or under unrelated pathophysiological conditions.}, }
@article {pmid24765662, year = {2014}, author = {Altamia, MA and Wood, N and Fung, JM and Dedrick, S and Linton, EW and Concepcion, GP and Haygood, MG and Distel, DL}, title = {Genetic differentiation among isolates of Teredinibacter turnerae, a widely occurring intracellular endosymbiont of shipworms.}, journal = {Molecular ecology}, volume = {23}, number = {6}, pages = {1418-1432}, pmid = {24765662}, issn = {1365-294X}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; U01TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Atlantic Ocean ; Bivalvia/*microbiology ; DNA, Bacterial/genetics ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; Genes, Bacterial ; Genetic Variation ; Indian Ocean ; Pacific Ocean ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Teredinibacter turnerae is a cultivable intracellular endosymbiont of xylotrophic (woodfeeding)bivalves of the Family Teredinidae (shipworms). Although T. turnerae has been isolated from many shipworm taxa collected in many locations, no systematic effort has been made to explore genetic diversity within this symbiont species across the taxonomic and geographical range of its hosts. The mode of symbiont transmission is unknown. Here, we examine sequence diversity in fragments of six genes (16S rRNA, gyrB, sseA, recA, rpoB and celAB) among 25 isolates of T. turnerae cultured from 13 shipworm species collected in 15 locations in the Atlantic, Pacific and Indian Oceans. While 16S rRNA sequences are nearly invariant between all examined isolates (maximum pairwise difference <0.26%), variation between examined protein-coding loci is greater (mean pairwise difference 2.2–5.9%). Phylogenetic analyses based on each protein-coding locus differentiate the 25 isolates into two distinct and well-supported clades. With five exceptions, clade assignments for each isolate were supported by analysis of alleles of each of the five protein-coding loci. These exceptions include (i) putative recombinant alleles of the celAB and gyrB loci in two isolates (PMS-535T.S.1b.3 and T8510), suggesting homologous recombination between members of the two clades; and (ii) evidence for a putative lateral gene transfer event affecting a second locus (recA) in three isolates (T8412, T8503 and T8513). These results demonstrate that T. turnerae isolates do not represent a homogeneous global population. Instead, they indicate the emergence of two lineages that, although distinct, likely experience some level of genetic exchange with each other and with other bacterial species.}, }
@article {pmid24763283, year = {2014}, author = {Brelsfoard, C and Tsiamis, G and Falchetto, M and Gomulski, LM and Telleria, E and Alam, U and Doudoumis, V and Scolari, F and Benoit, JB and Swain, M and Takac, P and Malacrida, AR and Bourtzis, K and Aksoy, S}, title = {Presence of extensive Wolbachia symbiont insertions discovered in the genome of its host Glossina morsitans morsitans.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {4}, pages = {e2728}, pmid = {24763283}, issn = {1935-2735}, support = {R01 AI051584/AI/NIAID NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; AI068932/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Blotting, Southern ; *Genome, Bacterial ; *Genome, Insect ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; *Mutagenesis, Insertional ; *Recombination, Genetic ; Sequence Analysis, DNA ; Tsetse Flies/*genetics ; Wolbachia/*genetics ; }, abstract = {Tsetse flies (Glossina spp.) are the cyclical vectors of Trypanosoma spp., which are unicellular parasites responsible for multiple diseases, including nagana in livestock and sleeping sickness in humans in Africa. Glossina species, including Glossina morsitans morsitans (Gmm), for which the Whole Genome Sequence (WGS) is now available, have established symbiotic associations with three endosymbionts: Wigglesworthia glossinidia, Sodalis glossinidius and Wolbachia pipientis (Wolbachia). The presence of Wolbachia in both natural and laboratory populations of Glossina species, including the presence of horizontal gene transfer (HGT) events in a laboratory colony of Gmm, has already been shown. We herein report on the draft genome sequence of the cytoplasmic Wolbachia endosymbiont (cytWol) associated with Gmm. By in silico and molecular and cytogenetic analysis, we discovered and validated the presence of multiple insertions of Wolbachia (chrWol) in the host Gmm genome. We identified at least two large insertions of chrWol, 527,507 and 484,123 bp in size, from Gmm WGS data. Southern hybridizations confirmed the presence of Wolbachia insertions in Gmm genome, and FISH revealed multiple insertions located on the two sex chromosomes (X and Y), as well as on the supernumerary B-chromosomes. We compare the chrWol insertions to the cytWol draft genome in an attempt to clarify the evolutionary history of the HGT events. We discuss our findings in light of the evolution of Wolbachia infections in the tsetse fly and their potential impacts on the control of tsetse populations and trypanosomiasis.}, }
@article {pmid24763256, year = {2014}, author = {Rose, C and Belmonte, R and Armstrong, SD and Molyneux, G and Haines, LR and Lehane, MJ and Wastling, J and Acosta-Serrano, A}, title = {An investigation into the protein composition of the teneral Glossina morsitans morsitans peritrophic matrix.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {4}, pages = {e2691}, pmid = {24763256}, issn = {1935-2735}, support = {//Wellcome Trust/United Kingdom ; 093691MA/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Chromatography, Liquid ; Gastrointestinal Tract/chemistry ; Male ; Mass Spectrometry ; Proteins/*analysis ; Proteome/*chemistry ; Tandem Mass Spectrometry ; Tsetse Flies/*chemistry ; }, abstract = {BACKGROUND: Tsetse flies serve as biological vectors for several species of African trypanosomes. In order to survive, proliferate and establish a midgut infection, trypanosomes must cross the tsetse fly peritrophic matrix (PM), which is an acellular gut lining surrounding the blood meal. Crossing of this multi-layered structure occurs at least twice during parasite migration and development, but the mechanism of how trypanosomes do so is not understood. In order to better comprehend the molecular events surrounding trypanosome penetration of the tsetse PM, a mass spectrometry-based approach was applied to investigate the PM protein composition using Glossina morsitans morsitans as a model organism.<br><br>METHODS: PMs from male teneral (young, unfed) flies were dissected, solubilised in urea/SDS buffer and the proteins precipitated with cold acetone/TCA. The PM proteins were either subjected to an in-solution tryptic digestion or fractionated on 1D SDS-PAGE, and the resulting bands digested using trypsin. The tryptic fragments from both preparations were purified and analysed by LC-MS/MS.<br><br>RESULTS: Overall, nearly 300 proteins were identified from both analyses, several of those containing signature Chitin Binding Domains (CBD), including novel peritrophins and peritrophin-like glycoproteins, which are essential in maintaining PM architecture and may act as trypanosome adhesins. Furthermore, 27 proteins from the tsetse secondary endosymbiont, Sodalis glossinidius, were also identified, suggesting this bacterium is probably in close association with the tsetse PM.<br><br>CONCLUSION: To our knowledge this is the first report on the protein composition of teneral G. m. morsitans, an important vector of African trypanosomes. Further functional analyses of these proteins will lead to a better understanding of the tsetse physiology and may help identify potential molecular targets to block trypanosome development within the tsetse.}, }
@article {pmid24763092, year = {2014}, author = {Chiel, E and Kelly, SE and Harris, AM and Gebiola, M and Li, X and Zchori-Fein, E and Hunter, MS}, title = {Characteristics, phenotype, and transmission of Wolbachia in the sweet potato whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), and its parasitoid Eretmocerus sp. nr. emiratus (Hymenoptera: Aphelinidae).}, journal = {Environmental entomology}, volume = {43}, number = {2}, pages = {353-362}, doi = {10.1603/EN13286}, pmid = {24763092}, issn = {1938-2936}, mesh = {Animals ; Computer Simulation ; Crosses, Genetic ; *Disease Transmission, Infectious ; Female ; Hemiptera/genetics/*microbiology/*parasitology/physiology ; Ipomoea batatas/parasitology ; Likelihood Functions ; Male ; Models, Biological ; *Phenotype ; Polymerase Chain Reaction ; Reproduction/genetics ; Species Specificity ; Symbiosis ; Wasps/genetics/*microbiology/physiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia is a common intracellular bacterial endosymbiont of insects, causing a variety of effects including reproductive manipulations such as cytoplasmic incompatibility (CI). In this study, we characterized Wolbachia in the whitefly Bemisia tabaci and in the whitefly parasitoid Eretmocerus sp. nr. emiratus. We also tested for horizontal transmission of Wolbachia between and within trophic levels, and we determined the phenotype of Wolbachia in E. sp. nr. emiratus. Using multilocus sequence typing and phylogenetic analyses, we found that B. tabaci and E. sp. nr. emiratus each harbor a different and unique strain of Wolbachia. Both strains belong to the phylogenetic supergroup B. No evidence for horizontal transmission of Wolbachia between and within trophic levels was found in our study system. Finally, crossing results were consistent with a CI phenotype; when Wolbachia-infected E. sp. nr. emiratus males mate with uninfected females, wasp progeny survival dropped significantly, and the number of females was halved. This is the first description of CI caused by Wolbachia in the economically important genus Eretmocerus. Our study underscores the expectation that horizontal transmission events occur rarely in the dynamics of secondary symbionts such as Wolbachia, and highlights the importance of understanding the effects of symbionts on the biology of natural enemies.}, }
@article {pmid24762979, year = {2014}, author = {Zangger, H and Hailu, A and Desponds, C and Lye, LF and Akopyants, NS and Dobson, DE and Ronet, C and Ghalib, H and Beverley, SM and Fasel, N}, title = {Leishmania aethiopica field isolates bearing an endosymbiontic dsRNA virus induce pro-inflammatory cytokine response.}, journal = {PLoS neglected tropical diseases}, volume = {8}, number = {4}, pages = {e2836}, pmid = {24762979}, issn = {1935-2735}, support = {R01 AI029646/AI/NIAID NIH HHS/United States ; R56 AI099364/AI/NIAID NIH HHS/United States ; AI29646/AI/NIAID NIH HHS/United States ; AI099364/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cytokines/*immunology ; Ethiopia ; Humans ; Leishmania/*immunology/isolation &amp; purification/*virology ; Leishmaniasis/parasitology ; Mice ; Molecular Sequence Data ; RNA Viruses/classification/genetics/*isolation &amp; purification ; RNA, Viral/genetics ; Sequence Analysis, DNA ; }, abstract = {BACKGROUND: Infection with Leishmania parasites causes mainly cutaneous lesions at the site of the sand fly bite. Inflammatory metastatic forms have been reported with Leishmania species such as L. braziliensis, guyanensis and aethiopica. Little is known about the factors underlying such exacerbated clinical presentations. Leishmania RNA virus (LRV) is mainly found within South American Leishmania braziliensis and guyanensis. In a mouse model of L. guyanensis infection, its presence is responsible for an hyper-inflammatory response driven by the recognition of the viral dsRNA genome by the host Toll-like Receptor 3 leading to an exacerbation of the disease. In one instance, LRV was reported outside of South America, namely in the L. major ASKH strain from Turkmenistan, suggesting that LRV appeared before the divergence of Leishmania subgenera. LRV presence inside Leishmania parasites could be one of the factors implicated in disease severity, providing rationale for LRV screening in L. aethiopica.<br><br>A new LRV member was identified in four L. aethiopica strains (LRV-Lae). Three LRV-Lae genomes were sequenced and compared to L. guyanensis LRV1 and L. major LRV2. LRV-Lae more closely resembled LRV2. Despite their similar genomic organization, a notable difference was observed in the region where the capsid protein and viral polymerase open reading frames overlap, with a unique -1 situation in LRV-Lae. In vitro infection of murine macrophages showed that LRV-Lae induced a TLR3-dependent inflammatory response as previously observed for LRV1.<br><br>CONCLUSIONS/SIGNIFICANCE: In this study, we report the presence of an immunogenic dsRNA virus in L. aethiopica human isolates. This is the first observation of LRV in Africa, and together with the unique description of LRV2 in Turkmenistan, it confirmed that LRV was present before the divergence of the L. (Leishmania) and (Viannia) subgenera. The potential implication of LRV-Lae on disease severity due to L. aethiopica infections is discussed.}, }
@article {pmid24759922, year = {2014}, author = {Mayoral, JG and Etebari, K and Hussain, M and Khromykh, AA and Asgari, S}, title = {Wolbachia infection modifies the profile, shuttling and structure of microRNAs in a mosquito cell line.}, journal = {PloS one}, volume = {9}, number = {4}, pages = {e96107}, pmid = {24759922}, issn = {1932-6203}, mesh = {Aedes/*genetics/*microbiology ; Animals ; Argonaute Proteins/genetics ; Cell Line ; Cell Nucleus/*genetics ; Cytoplasm/*genetics ; Gene Expression Regulation ; High-Throughput Nucleotide Sequencing ; Host-Pathogen Interactions ; Insect Proteins/genetics ; MicroRNAs/chemistry/*genetics ; Molecular Sequence Data ; RNA Transport ; Wolbachia/*physiology ; }, abstract = {MicroRNAs (miRNAs) are small non-coding RNAs that play important roles in many biological processes such as development, cell signaling and immune response. Small RNA deep sequencing technology provided an opportunity for a thorough survey of the miRNA profile of a mosquito cell line from Aedes aegypti. We characterized the miRNA composition of the nucleus and the cytoplasm of uninfected cells and compared it with the one of cells infected with the endosymbiotic bacterium Wolbachia strain wMelPop-CLA. We found an overall increase of small RNAs between 18 and 28 nucleotides in both cellular compartments in Wolbachia-infected cells and identified specific miRNAs induced and/or suppressed by the Wolbachia infection. We discuss the mechanisms that the cell may use to shuttle miRNAs between the cytoplasm and the nucleus. In addition, we identified piRNAs that changed their abundance in response to Wolbachia infection. The miRNAs and piRNAs identified in this study provide promising leads for investigations into the host-endosymbiont interactions and for better understanding of how Wolbachia manipulates the host miRNA machinery in order to facilitate its persistent replication in infected cells.}, }
@article {pmid24751196, year = {2014}, author = {Gray, S and Cilia, M and Ghanim, M}, title = {Circulative, "nonpropagative" virus transmission: an orchestra of virus-, insect-, and plant-derived instruments.}, journal = {Advances in virus research}, volume = {89}, number = {}, pages = {141-199}, doi = {10.1016/B978-0-12-800172-1.00004-5}, pmid = {24751196}, issn = {1557-8399}, mesh = {Animals ; *Host-Parasite Interactions ; Insect Control ; Insect Vectors/*virology ; Plant Diseases/prevention &amp; control/*virology ; Plants/*virology ; }, abstract = {Species of plant viruses within the Luteoviridae, Geminiviridae, and Nanoviridae are transmitted by phloem-feeding insects in a circulative, nonpropagative manner. The precise route of virus movement through the vector can differ across and within virus families, but these viruses all share many biological, biochemical, and ecological features. All share temporal and spatial constraints with respect to transmission efficiency. The viruses also induce physiological changes in their plant hosts resulting in behavioral changes in the insects that optimize the transmission of virus to new hosts. Virus proteins interact with insect, endosymbiont, and plant proteins to orchestrate, directly and indirectly, virus movement in insects and plants to facilitate transmission. Knowledge of these complex interactions allows for the development of new tools to reduce or prevent transmission, to quickly identify important vector populations, and to improve the management of these economically important viruses affecting agricultural and natural plant populations.}, }
@article {pmid24747986, year = {2014}, author = {Ishida, K and Sekizuka, T and Hayashida, K and Matsuo, J and Takeuchi, F and Kuroda, M and Nakamura, S and Yamazaki, T and Yoshida, M and Takahashi, K and Nagai, H and Sugimoto, C and Yamaguchi, H}, title = {Amoebal endosymbiont Neochlamydia genome sequence illuminates the bacterial role in the defense of the host amoebae against Legionella pneumophila.}, journal = {PloS one}, volume = {9}, number = {4}, pages = {e95166}, pmid = {24747986}, issn = {1932-6203}, mesh = {Amoeba/pathogenicity/*physiology ; Chlamydia/genetics/*pathogenicity ; *Genome, Bacterial ; Legionella pneumophila/*pathogenicity ; Molecular Sequence Data ; *Symbiosis ; }, abstract = {Previous work has shown that the obligate intracellular amoebal endosymbiont Neochlamydia S13, an environmental chlamydia strain, has an amoebal infection rate of 100%, but does not cause amoebal lysis and lacks transferability to other host amoebae. The underlying mechanism for these observations remains unknown. In this study, we found that the host amoeba could completely evade Legionella infection. The draft genome sequence of Neochlamydia S13 revealed several defects in essential metabolic pathways, as well as unique molecules with leucine-rich repeats (LRRs) and ankyrin domains, responsible for protein-protein interaction. Neochlamydia S13 lacked an intact tricarboxylic acid cycle and had an incomplete respiratory chain. ADP/ATP translocases, ATP-binding cassette transporters, and secretion systems (types II and III) were well conserved, but no type IV secretion system was found. The number of outer membrane proteins (OmcB, PomS, 76-kDa protein, and OmpW) was limited. Interestingly, genes predicting unique proteins with LRRs (30 genes) or ankyrin domains (one gene) were identified. Furthermore, 33 transposases were found, possibly explaining the drastic genome modification. Taken together, the genomic features of Neochlamydia S13 explain the intimate interaction with the host amoeba to compensate for bacterial metabolic defects, and illuminate the role of the endosymbiont in the defense of the host amoebae against Legionella infection.}, }
@article {pmid24747216, year = {2014}, author = {Kawasaki, Y and Ito, H and Kajimura, H}, title = {Equilibrium frequency of endosymbionts in multiple infections based on the balance between vertical transmission and cytoplasmic incompatibility.}, journal = {PloS one}, volume = {9}, number = {4}, pages = {e94900}, pmid = {24747216}, issn = {1932-6203}, mesh = {*Bacteria ; *Bacterial Infections ; *Bacterial Physiological Phenomena ; Cytoplasm/*microbiology ; *Models, Biological ; Reproduction ; *Symbiosis ; }, abstract = {Cytoplasmic incompatibility (CI)-inducing endosymbiotic bacteria, such as Wolbachia and Cardinium, have been well studied through field data and validations on the basis of numerical simulations. However, the analytically derived equilibrium frequency of multiple infections has not yet been determined, although the equilibrium for cases of single infection has been reported. In this study, we considered the difference equation for endosymbionts using three parameters: the probability of the failure of vertical transmission ([Formula: see text]), CI strength ([Formula: see text]), and the level of host inbreeding ([Formula: see text]). To analyze this model, we particularly focused on [Formula: see text], i.e., the frequency of host individuals completely infected with all [Formula: see text]-bacterial strains in the population. [Formula: see text], [Formula: see text] at the equilibrium state, was analytically calculated in the cases where [Formula: see text] and [Formula: see text] is any arbitrary value. We found that [Formula: see text] can be described using two parameters: [Formula: see text] and [Formula: see text], which is identical to [Formula: see text]. [Formula: see text] has a larger value in a system with a smaller [Formula: see text]. In addition, [Formula: see text] determines the maximum number of strains that infect a single host. Our results revealed the following: i) three parameters can be reduced to a single parameter, i.e., [Formula: see text] and ii) the threshold of the maximum number of infections is defined by [Formula: see text], which prevents additional invasions by endosymbionts.}, }
@article {pmid24741474, year = {2014}, author = {Sabree, ZL and Moran, NA}, title = {Host-specific assemblages typify gut microbial communities of related insect species.}, journal = {SpringerPlus}, volume = {3}, number = {}, pages = {138}, pmid = {24741474}, issn = {2193-1801}, abstract = {Mutualisms between microbes and insects are ubiquitous and facilitate exploitation of various trophic niches by host insects. Dictyopterans (mantids, cockroaches and termites) exhibit trophisms that range from omnivory to strict wood-feeding and maintain beneficial symbioses with the obligate endosymbiont, Blattabacterium, and/or diverse gut microbiomes that include cellulolytic and diazotrophic microbes. While Blattabacterium in omnivorous Periplaneta is fully capable of provisioning essential amino acids, in wood-feeding dictyopterans it has lost many genes for their biosynthesis (Mastotermes and Cryptocercus) or is completely absent (Heterotermes). The conspicuous functional degradation and absence of Blattabacterium in most strict wood-feeding dictyopteran insects suggest that alternative means of acquiring nutrients limited in their diet are being employed. A 16S rRNA gene amplicon resequencing approach was used to deeply sample the composition and diversity of gut communities in related dictyopteran insects to explore the possibility of shifts in symbiont allegiances during termite and cockroach evolution. The gut microbiome of Periplaneta, which has a fully functional Blattabacterium, exhibited the greatest within-sample operational taxonomic unit (OTU) diversity and abundance variability than those of Mastotermes and Cryptocercus, whose Blattabacterium have shrunken genomes and reduced nutrient provisioning capabilities. Heterotermes lacks Blattabacterium and a single OTU that was 95% identical to a Bacteroidia-assigned diazotrophic endosymbiont of an anaerobic cellulolytic protist termite gut inhabitant samples consistently dominates its gut microbiome. Many host-specific OTUs were identified in all host genera, some of which had not been previously detected, indicating that deep sampling by pyrotag sequencing has revealed new taxa that remain to be functionally characterized. Further analysis is required to uncover how consistently detected taxa in the cockroach and termite gut microbiomes, as well as the total community, contribute to host diet choice and impact the fate of Blattabacterium in dictyopterans.}, }
@article {pmid24739623, year = {2014}, author = {Giovannoni, SJ and Cameron Thrash, J and Temperton, B}, title = {Implications of streamlining theory for microbial ecology.}, journal = {The ISME journal}, volume = {8}, number = {8}, pages = {1553-1565}, pmid = {24739623}, issn = {1751-7370}, mesh = {Bacteria/genetics/growth &amp; development ; Ecological and Environmental Phenomena ; *Evolution, Molecular ; Genetic Drift ; *Genome Size ; Genome, Archaeal ; *Genome, Bacterial ; }, abstract = {Whether a small cell, a small genome or a minimal set of chemical reactions with self-replicating properties, simplicity is beguiling. As Leonardo da Vinci reportedly said, 'simplicity is the ultimate sophistication'. Two diverging views of simplicity have emerged in accounts of symbiotic and commensal bacteria and cosmopolitan free-living bacteria with small genomes. The small genomes of obligate insect endosymbionts have been attributed to genetic drift caused by small effective population sizes (Ne). In contrast, streamlining theory attributes small cells and genomes to selection for efficient use of nutrients in populations where Ne is large and nutrients limit growth. Regardless of the cause of genome reduction, lost coding potential eventually dictates loss of function. Consequences of reductive evolution in streamlined organisms include atypical patterns of prototrophy and the absence of common regulatory systems, which have been linked to difficulty in culturing these cells. Recent evidence from metagenomics suggests that streamlining is commonplace, may broadly explain the phenomenon of the uncultured microbial majority, and might also explain the highly interdependent (connected) behavior of many microbial ecosystems. Streamlining theory is belied by the observation that many successful bacteria are large cells with complex genomes. To fully appreciate streamlining, we must look to the life histories and adaptive strategies of cells, which impose minimum requirements for complexity that vary with niche.}, }
@article {pmid24736017, year = {2014}, author = {Arneodo, JD and Ortego, J}, title = {Exploring the bacterial microbiota associated with native South American species of Aphis (Hemiptera: Aphididae).}, journal = {Environmental entomology}, volume = {43}, number = {3}, pages = {589-594}, doi = {10.1603/EN13324}, pmid = {24736017}, issn = {1938-2936}, mesh = {Animals ; Aphids/*microbiology ; Argentina ; Bacteria/genetics/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Buchnera/genetics/isolation &amp; purification/physiology ; Cloning, Molecular ; Genes, Insect/genetics ; Microbiota/genetics/*physiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {Aphids harbor a variety of bacterial endosymbionts, including the obligate symbiont Buchnera aphidicola and diverse facultative symbionts. The former supplies its host with essential amino acids. The latter are not indispensable for insect survival, but often improve their host's fitness. To date, the study of such associations was restricted to aphids of Holarctic origin. The bacterial microbiota of seven Aphis species from Argentina was investigated. The presence of B. aphidicola was assessed by specific PCR. Additional symbionts were identified through PCR with eubacterial universal primers, cloning, and sequencing of nearly complete 16S rRNA gene, intergenic spacer region, and partial 23S rRNA gene and subjected to phylogenetic analysis. Infection with B. aphidicola was confirmed in every species analyzed. The facultative symbiont Serratia symbiotica was detected in Aphis malalhuina Mier Durante, Nieto Nafría &amp; Ortego, 2003, Aphis senecionicoides Blanchard, 1944, and Aphis schinifoliae Blanchard, 1939, while Hamiltonella defensa was identified in Aphis mendocina Mier Durante, Ortego &amp; Nieto Nafría, 2006. Arsenophonus sp. was found infecting Aphis melosae Mier Durante &amp; Ortego, 1999, and a new, undescribed Aphis sp. In Aphis danielae Remaudière, 1994, no facultative symbionts could be recorded. When analyzing the highly conserved 16S rRNA gene, the phylogenetic tree grouped the S. symbiotica, H. defensa, and Arsenophonus isolates into three well-defined clusters showing little variability among clones corresponding to the same aphid host species. This article reports for the first time the endosymbionts associated with aphids native to South America. Despite their geographic origin, the qualitative composition of their microbiota revealed no evident differences from that described for aphids in the Northern Hemisphere.}, }
@article {pmid24735869, year = {2014}, author = {Douglas, AE}, title = {The molecular basis of bacterial-insect symbiosis.}, journal = {Journal of molecular biology}, volume = {426}, number = {23}, pages = {3830-3837}, pmid = {24735869}, issn = {1089-8638}, support = {R01 GM095372/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*growth &amp; development/immunology ; *Bacterial Physiological Phenomena ; Immunity, Innate ; Insecta/immunology/*microbiology ; *Symbiosis ; }, abstract = {Insects provide experimentally tractable and cost-effective model systems to investigate the molecular basis of animal-bacterial interactions. Recent research is revealing the central role of the insect innate immune system, especially anti-microbial peptides and reactive oxygen species, in regulating the abundance and composition of the microbiota in various insects, including Drosophila and the mosquitoes Aedes and Anopheles. Interactions between the immune system and microbiota are, however, bidirectional with evidence that members of the resident microbiota can promote immune function, conferring resistance to pathogens and parasites by both activation of immune effectors and production of toxins. Antagonistic and mutualistic interactions among bacteria have also been implicated as determinants of the microbiota composition, including exclusion of pathogens, but the molecular mechanisms are largely unknown. Some bacteria are crucial for insect nutrition, through provisioning of specific nutrients (e.g., B vitamins, essential amino acids) and modulation of the insect nutritional sensing and signaling pathways (e.g., insulin signaling) that regulate nutrient allocation, especially to lipid and other energy reserves. A key challenge for future research is to identify the molecular interaction between specific bacterial effectors and animal receptors, as well as to determine how these interactions translate into microbiota-dependent signaling, metabolism, and immune function in the host.}, }
@article {pmid24732463, year = {2014}, author = {Ross, PA and Endersby, NM and Yeap, HL and Hoffmann, AA}, title = {Larval competition extends developmental time and decreases adult size of wMelPop Wolbachia-infected Aedes aegypti.}, journal = {The American journal of tropical medicine and hygiene}, volume = {91}, number = {1}, pages = {198-205}, pmid = {24732463}, issn = {1476-1645}, mesh = {Aedes/growth &amp; development/*microbiology ; Animals ; Biological Control Agents ; Female ; Insect Vectors/growth &amp; development/*microbiology ; Larva/growth &amp; development/*microbiology ; Male ; Pest Control, Biological/*methods ; Wolbachia/*pathogenicity/physiology ; }, abstract = {The intracellular endosymbiont Wolbachia has been artificially transinfected into the dengue vector Aedes aegypti, where it is being investigated as a potential dengue biological control agent. Invasion of Wolbachia in natural populations depends upon the fitness of Wolbachia-infected Ae. aegypti relative to uninfected competitors. Although Wolbachia infections impose fitness costs on the adult host, effects at the immature stages are less clear, particularly in competitive situations. We look for effects of two Wolbachia infections, wMel and wMelPop, on intra-strain and inter-strain larval competition in Ae. aegypti. Development of Wolbachia-infected larvae is delayed in mixed cohorts with uninfected larvae under crowded-rearing conditions. Slow developing wMelPop-infected larvae have reduced adult size compared with uninfected larvae, and larvae with the wMel infection are somewhat larger and have greater viability relative to uninfected larvae when in mixed cohorts. Implications for successful invasion by these Wolbachia infections under field conditions are considered.}, }
@article {pmid24728373, year = {2014}, author = {Quigley, KM and Davies, SW and Kenkel, CD and Willis, BL and Matz, MV and Bay, LK}, title = {Deep-sequencing method for quantifying background abundances of symbiodinium types: exploring the rare symbiodinium biosphere in reef-building corals.}, journal = {PloS one}, volume = {9}, number = {4}, pages = {e94297}, pmid = {24728373}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*physiology ; Base Sequence ; *Coral Reefs ; Dinoflagellida/*genetics ; *Ecosystem ; Haplotypes/genetics ; High-Throughput Nucleotide Sequencing/*methods ; Limit of Detection ; Palau ; Symbiosis/genetics ; }, abstract = {The capacity of reef-building corals to associate with environmentally-appropriate types of endosymbionts from the dinoflagellate genus Symbiodinium contributes significantly to their success at local scales. Additionally, some corals are able to acclimatize to environmental perturbations by shuffling the relative proportions of different Symbiodinium types hosted. Understanding the dynamics of these symbioses requires a sensitive and quantitative method of Symbiodinium genotyping. Electrophoresis methods, still widely utilized for this purpose, are predominantly qualitative and cannot guarantee detection of a background type below 10% of the total Symbiodinium population. Here, the relative abundances of four Symbiodinium types (A13, C1, C3, and D1) in mixed samples of known composition were quantified using deep sequencing of the internal transcribed spacer of the ribosomal RNA gene (ITS-2) by means of Next Generation Sequencing (NGS) using Roche 454. In samples dominated by each of the four Symbiodinium types tested, background levels of the other three types were detected when present at 5%, 1%, and 0.1% levels, and their relative abundances were quantified with high (A13, C1, D1) to variable (C3) accuracy. The potential of this deep sequencing method for resolving fine-scale genetic diversity within a symbiont type was further demonstrated in a natural symbiosis using ITS-1, and uncovered reef-specific differences in the composition of Symbiodinium microadriaticum in two species of acroporid corals (Acropora digitifera and A. hyacinthus) from Palau. The ability of deep sequencing of the ITS locus (1 and 2) to detect and quantify low-abundant Symbiodinium types, as well as finer-scale diversity below the type level, will enable more robust quantification of local genetic diversity in Symbiodinium populations. This method will help to elucidate the role that background types have in maximizing coral fitness across diverse environments and in response to environmental change.}, }
@article {pmid24723729, year = {2014}, author = {Santos-Garcia, D and Rollat-Farnier, PA and Beitia, F and Zchori-Fein, E and Vavre, F and Mouton, L and Moya, A and Latorre, A and Silva, FJ}, title = {The genome of Cardinium cBtQ1 provides insights into genome reduction, symbiont motility, and its settlement in Bemisia tabaci.}, journal = {Genome biology and evolution}, volume = {6}, number = {4}, pages = {1013-1030}, pmid = {24723729}, issn = {1759-6653}, mesh = {Animals ; Base Sequence ; Cytophagaceae/*genetics ; *Evolution, Molecular ; Genome, Bacterial/*physiology ; Hemiptera/*microbiology ; Molecular Sequence Data ; Symbiosis/*physiology ; }, abstract = {Many insects harbor inherited bacterial endosymbionts. Although some of them are not strictly essential and are considered facultative, they can be a key to host survival under specific environmental conditions, such as parasitoid attacks, climate changes, or insecticide pressures. The whitefly Bemisia tabaci is at the top of the list of organisms inflicting agricultural damage and outbreaks, and changes in its distribution may be associated to global warming. In this work, we have sequenced and analyzed the genome of Cardinium cBtQ1, a facultative bacterial endosymbiont of B. tabaci and propose that it belongs to a new taxonomic family, which also includes Candidatus Amoebophilus asiaticus and Cardinium cEper1, endosymbionts of amoeba and wasps, respectively. Reconstruction of their last common ancestors' gene contents revealed an initial massive gene loss from the free-living ancestor. This was followed in Cardinium by smaller losses, associated with settlement in arthropods. Some of these losses, affecting cofactor and amino acid biosynthetic encoding genes, took place in Cardinium cBtQ1 after its divergence from the Cardinium cEper1 lineage and were related to its settlement in the whitefly and its endosymbionts. Furthermore, the Cardinium cBtQ1 genome displays a large proportion of transposable elements, which have recently inactivated genes and produced chromosomal rearrangements. The genome also contains a chromosomal duplication and a multicopy plasmid, which harbors several genes putatively associated with gliding motility, as well as two other genes encoding proteins with potential insecticidal activity. As gene amplification is very rare in endosymbionts, an important function of these genes cannot be ruled out.}, }
@article {pmid24722540, year = {2014}, author = {Zhang, CR and Zhang, S and Xia, J and Li, FF and Xia, WQ and Liu, SS and Wang, XW}, title = {The immune strategy and stress response of the Mediterranean species of the Bemisia tabaci complex to an orally delivered bacterial pathogen.}, journal = {PloS one}, volume = {9}, number = {4}, pages = {e94477}, pmid = {24722540}, issn = {1932-6203}, mesh = {Animals ; Antimicrobial Cationic Peptides/*genetics/immunology ; Cystine-Knot Miniproteins/*genetics/immunology ; Gene Expression Regulation ; *Genome, Insect ; Hemiptera/*genetics/immunology/microbiology ; Host-Pathogen Interactions ; Immunity, Cellular ; Immunity, Humoral ; Insect Proteins/*genetics/immunology ; Longevity/immunology ; Molecular Sequence Annotation ; Pest Control, Biological ; Pseudomonas aeruginosa/physiology ; Stress, Physiological/immunology ; }, abstract = {BACKGROUND: The whitefly, Bemisia tabaci, a notorious agricultural pest, has complex relationships with diverse microbes. The interactions of the whitefly with entomopathogens as well as its endosymbionts have received great attention, because of their potential importance in developing novel whitefly control technologies. To this end, a comprehensive understanding on the whitefly defense system is needed to further decipher those interactions.<br><br>We conducted a comprehensive investigation of the whitefly's defense responses to infection, via oral ingestion, of the pathogen, Pseudomonas aeruginosa, using RNA-seq technology. Compared to uninfected whiteflies, 6 and 24 hours post-infected whiteflies showed 1,348 and 1,888 differentially expressed genes, respectively. Functional analysis of the differentially expressed genes revealed that the mitogen associated protein kinase (MAPK) pathway was activated after P. aeruginosa infection. Three knottin-like antimicrobial peptide genes and several components of the humoral and cellular immune responses were also activated, indicating that key immune elements recognized in other insect species are also important for the response of B. tabaci to pathogens. Our data also suggest that intestinal stem cell mediated epithelium renewal might be an important component of the whitefly's defense against oral bacterial infection. In addition, we show stress responses to be an essential component of the defense system.<br><br>CONCLUSIONS/SIGNIFICANCE: We identified for the first time the key immune-response elements utilized by B. tabaci against bacterial infection. This study provides a framework for future research into the complex interactions between whiteflies and microbes.}, }
@article {pmid24721569, year = {2014}, author = {Randow, F and Youle, RJ}, title = {Self and nonself: how autophagy targets mitochondria and bacteria.}, journal = {Cell host &amp; microbe}, volume = {15}, number = {4}, pages = {403-411}, pmid = {24721569}, issn = {1934-6069}, support = {MC_U105170648/MRC_/Medical Research Council/United Kingdom ; ZIA NS003123-03/ImNIH/Intramural NIH HHS/United States ; U105170648/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Autophagy/*immunology ; Bacteria/*immunology ; Humans ; Lysosomes/metabolism ; Mitochondria/*metabolism ; *Mitophagy ; Signal Transduction/immunology ; }, abstract = {Autophagy is an evolutionarily conserved pathway that transports cytoplasmic components for degradation into lysosomes. Selective autophagy can capture physically large objects, including cell-invading pathogens and damaged or superfluous organelles. Selectivity is achieved by cargo receptors that detect substrate-associated "eat-me" signals. In this Review, we discuss basic principles of selective autophagy and compare the "eat-me" signals and cargo receptors that mediate autophagy of bacteria and bacteria-derived endosymbionts-i.e., mitochondria.}, }
@article {pmid24721205, year = {2014}, author = {Liu, C and Wang, JL and Zheng, Y and Xiong, EJ and Li, JJ and Yuan, LL and Yu, XQ and Wang, YF}, title = {Wolbachia-induced paternal defect in Drosophila is likely by interaction with the juvenile hormone pathway.}, journal = {Insect biochemistry and molecular biology}, volume = {49}, number = {}, pages = {49-58}, doi = {10.1016/j.ibmb.2014.03.014}, pmid = {24721205}, issn = {1879-0240}, mesh = {Animals ; Drosophila Proteins/genetics/*metabolism ; Drosophila melanogaster/embryology/*genetics/metabolism/*microbiology ; Female ; Juvenile Hormones/*metabolism ; Male ; Ovum/metabolism/microbiology ; Signal Transduction ; Species Specificity ; Testis/metabolism/microbiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia are endosymbionts that infect many insect species. They can manipulate the host's reproduction to increase their own maternal transmission. Cytoplasmic incompatibility (CI) is one such manipulation, which is expressed as embryonic lethality when Wolbachia-infected males mate with uninfected females. However, matings between males and females carrying the same Wolbachia strain result in viable progeny. The molecular mechanisms of CI are currently not clear. We have previously reported that the gene Juvenile hormone-inducible protein 26 (JhI-26) exhibited the highest upregulation in the 3rd instar larval testes of Drosophila melanogaster when infected by Wolbachia. This is reminiscent of an interaction between Wolbachia and juvenile hormone (JH) pathway in flies. Considering that Jhamt gene encodes JH acid methyltransferase, a key regulatory enzyme of JH biosynthesis, and that methoprene-tolerant (Met) has been regarded as the best JH receptor candidate, we first compared the expression of Jhamt and Met between Wolbachia-infected and uninfected fly testes to investigate whether Wolbachia infection influence the JH signaling pathway. We found that the expressions of Jhamt and Met were significantly increased in the presence of Wolbachia, suggesting an interaction of Wolbachia with the JH signaling pathway. Then, we found that overexpression of JhI-26 in Wolbachia-free transgenic male flies caused paternal-effect lethality that mimics the defects associated with CI. JhI-26 overexpressing males resulted in significantly decrease in hatch rate. Surprisingly, Wolbachia-infected females could rescue the egg hatch. In addition, we showed that overexpression of JhI-26 caused upregulation of the male accessory gland protein (Acp) gene CG10433, but not vice versa. This result suggests that JhI-26 may function at the upstream of CG10433. Likewise, overexpression of CG10433 also resulted in paternal-effect lethality. Both JhI-26 and CG10433 overexpressing males resulted in nuclear division defects in the early embryos. Finally, we found that Wolbachia-infected males decreased the propensity of the mated females to remating, a phenotype also caused by both JhI-26 and CG10433 overexpressing males. Taken together, our results provide a working hypothesis whereby Wolbachia induce paternal defects in Drosophila probably by interaction with the JH pathway via JH response genes JhI-26 and CG10433.}, }
@article {pmid24710516, year = {2014}, author = {Lim, K and Kobayashi, I and Nakai, K}, title = {Alterations in rRNA-mRNA interaction during plastid evolution.}, journal = {Molecular biology and evolution}, volume = {31}, number = {7}, pages = {1728-1740}, doi = {10.1093/molbev/msu120}, pmid = {24710516}, issn = {1537-1719}, mesh = {Chlorophyta/genetics ; Cyanobacteria/genetics ; Euglenida/genetics ; Evolution, Molecular ; Genome, Plastid ; Phylogeny ; Plastids/*classification/*genetics ; RNA, Messenger/*metabolism ; RNA, Ribosomal/*metabolism ; }, abstract = {Translation initiation depends on the recognition of mRNA by a ribosome. For this to occur, prokaryotes primarily use the Shine-Dalgarno (SD) interaction, where the 3'-tail of small subunit rRNA (core motif: 3'CCUCC) forms base pairs with a complementary signal sequence in the 5'-untranslated region of mRNA. Here, we examined what happened to SD interactions during the evolution of a cyanobacterial endosymbiont into modern plastids (including chloroplasts). Our analysis of available complete plastid genome sequences revealed that the majority of plastids retained SD interactions but with varying levels of usage. Parallel losses of SD interactions took place in plastids of Chlorophyta, Euglenophyta, and Chromerida/Apicomplexa lineages, presumably related to their extensive reductive evolution. Interestingly, we discovered that the classical SD interaction (3'CCUCC/5'GGAGG [rRNA/mRNA]) was replaced by an altered SD interaction (3'CCCU/5'GGGA or 3'CUUCC/5'GAAGG) through coordinated changes in the sequences of the core rRNA motif and its paired mRNA signal. These changes in plastids of Chlorophyta and Euglenophyta proceeded through intermediate stages that allowed both the classical and altered SD interactions. This coevolution between the rRNA motif and the mRNA signal demonstrates unexpected plasticity in the translation initiation machinery.}, }
@article {pmid24709562, year = {2014}, author = {Hirakawa, Y and Ishida, K}, title = {Polyploidy of endosymbiotically derived genomes in complex algae.}, journal = {Genome biology and evolution}, volume = {6}, number = {4}, pages = {974-980}, pmid = {24709562}, issn = {1759-6653}, mesh = {Cryptophyta/*genetics ; DNA, Plant/*genetics ; *Evolution, Molecular ; Genome, Plant/*physiology ; Symbiosis/*physiology ; *Tetraploidy ; }, abstract = {Chlorarachniophyte and cryptophyte algae have complex plastids that were acquired by the uptake of a green or red algal endosymbiont via secondary endosymbiosis. The plastid is surrounded by four membranes, and a relict nucleus, called the nucleomorph, remains in the periplastidal compartment that is the remnant cytoplasm of the endosymbiont. Thus, these two algae possess four different genomes in a cell: Nuclear, nucleomorph, plastid, and mitochondrial. Recently, sequencing of the nuclear genomes of the chlorarachniophyte Bigelowiella natans and the cryptophyte Guillardia theta has been completed, and all four genomes have been made available. However, the copy number of each genome has never been investigated. It is important to know the actual DNA content of each genome, especially the highly reduced nucleomorph genome, for studies on genome evolution. In this study, we calculated genomic copy numbers in B. natans and G. theta using a real-time quantitative polymerase chain reaction approach. The nuclear genomes were haploid in both species, whereas the nucleomorph genomes were estimated to be diploid and tetraploid, respectively. Mitochondria and plastids contained a large copy number of genomic DNA in each cell. In the secondary endosymbioses of chlorarachniophytes and cryptophytes, the endosymbiont nuclear genomes were highly reduced in size and in the number of coding genes, whereas the chromosomal copy number was increased, as in bacterial endosymbiont genomes. This suggests that polyploidization is a general characteristic of highly reduced genomes in broad prokaryotic and eukaryotic endosymbionts.}, }
@article {pmid24706863, year = {2014}, author = {Farkas, A and Maróti, G and Durgő, H and Györgypál, Z and Lima, RM and Medzihradszky, KF and Kereszt, A and Mergaert, P and Kondorosi, &#xc9;}, title = {Medicago truncatula symbiotic peptide NCR247 contributes to bacteroid differentiation through multiple mechanisms.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, number = {14}, pages = {5183-5188}, pmid = {24706863}, issn = {1091-6490}, mesh = {Anti-Bacterial Agents/pharmacology ; Bacteria/drug effects ; Bacterial Proteins/biosynthesis ; Medicago truncatula/*metabolism/microbiology ; Nitrogen Fixation ; Peptides/*physiology ; Plant Proteins/*chemistry ; Protein Binding ; *Symbiosis ; }, abstract = {Symbiosis between rhizobia soil bacteria and legume plants results in the formation of root nodules where plant cells are fully packed with nitrogen fixing bacteria. In the host cells, the bacteria adapt to the intracellular environment and gain the ability for nitrogen fixation. Depending on the host plants, the symbiotic fate of bacteria can be either reversible or irreversible. In Medicago and related legume species, the bacteria undergo a host-directed multistep differentiation process culminating in the formation of elongated and branched polyploid bacteria with definitive loss of cell division ability. The plant factors are nodule-specific symbiotic peptides. Approximately 600 of them are nodule-specific cysteine-rich (NCR) peptides produced in the rhizobium-infected plant cells. NCRs are targeted to the endosymbionts, and concerted action of different sets of peptides governs different stages of endosymbiont maturation, whereas the symbiotic function of individual NCRs is unknown. This study focused on NCR247, a cationic peptide exhibiting in vitro antimicrobial activities. We show that NCR247 acts in those nodule cells where bacterial cell division is arrested and cell elongation begins. NCR247 penetrates the bacteria and forms complexes with many bacterial proteins. Interaction with FtsZ required for septum formation is one of the host interventions for inhibiting bacterial cell division. Complex formation with the ribosomal proteins affects translation and contributes to altered proteome and physiology of the endosymbiont. Binding to the chaperone GroEL amplifies the NCR247-modulated biological processes. We show that GroEL1 of Sinorhizobium meliloti is required for efficient infection, terminal differentiation, and nitrogen fixation.}, }
@article {pmid24706597, year = {2014}, author = {Terraz, G and Gueguen, G and Arnó, J and Fleury, F and Mouton, L}, title = {Nuclear and cytoplasmic differentiation among Mediterranean populations of Bemisia tabaci: testing the biological relevance of cytotypes.}, journal = {Pest management science}, volume = {70}, number = {10}, pages = {1503-1513}, doi = {10.1002/ps.3792}, pmid = {24706597}, issn = {1526-4998}, mesh = {Animals ; Bacteria/genetics/isolation &amp; purification ; Europe ; Hemiptera/*classification/*genetics/microbiology ; Insecticide Resistance/genetics ; Microsatellite Repeats/*genetics ; Mitochondria/*genetics ; *Phylogeography ; *Reproductive Isolation ; *Symbiosis ; }, abstract = {BACKGROUND: The taxonomy of the species complex Bemisia tabaci is still an unresolved issue. Recently, phylogenetic analysis based on mtCOI identified 31 cryptic species. However, mitochondrial diversity is observed within these species, associated with distinct symbiotic bacterial communities forming associations, which here are called cytotypes. The authors investigated the biological significance of two cytotypes (Q1 and Q2) belonging to the Mediterranean species, which have only been found in allopatry in the Western Mediterranean to date. Sampling was done over a few years in Western Europe, and sympatric situations were found that allowed their reproductive compatibility to be tested in the field with the use of microsatellites.<br><br>RESULTS: The field survey indicated that, in spite of its recent introduction, Q2 is well established in France and Spain, where it coexists with Q1. Microsatellite data showed that, in allopatry, Q1 and Q2 are highly differentiated, while there is little or no genetic differentiation when they coexist in sympatry, suggesting a high rate of hybridisation. Crossing experiments in the lab confirmed their interfertility.<br><br>CONCLUSION: Q1 and Q2 hybridise, which confirms that they belong to the same species, in spite of the high degree of genetic differentiation at both the cytoplasmic and nuclear levels, and also suggests that their symbiotic bacteria do not prevent hybridisation.}, }
@article {pmid24704120, year = {2014}, author = {Salminen, A and Kaarniranta, K and Hiltunen, M and Kauppinen, A}, title = {Krebs cycle dysfunction shapes epigenetic landscape of chromatin: novel insights into mitochondrial regulation of aging process.}, journal = {Cellular signalling}, volume = {26}, number = {7}, pages = {1598-1603}, doi = {10.1016/j.cellsig.2014.03.030}, pmid = {24704120}, issn = {1873-3913}, mesh = {Aging/*genetics/physiology ; Chromatin/*genetics ; Citric Acid Cycle/*genetics ; DNA/genetics ; DNA Methylation ; DNA-Binding Proteins/metabolism ; Dioxygenases/metabolism ; *Epigenesis, Genetic ; Fumarates/metabolism ; Histones/genetics ; Humans ; Jumonji Domain-Containing Histone Demethylases/metabolism ; Ketoglutaric Acids/metabolism ; Mitochondria/*genetics/physiology ; Mixed Function Oxygenases/metabolism ; Proto-Oncogene Proteins/metabolism ; Succinic Acid/metabolism ; }, abstract = {Although there is a substantial literature that mitochondria have a crucial role in the aging process, the mechanism has remained elusive. The role of reactive oxygen species, mitochondrial DNA injuries, and a decline in mitochondrial quality control has been proposed. Emerging studies have demonstrated that Krebs cycle intermediates, 2-oxoglutarate (also known as α-ketoglutarate), succinate and fumarate, can regulate the level of DNA and histone methylation. Moreover, citrate, also a Krebs cycle metabolite, can enhance histone acetylation. Genome-wide screening studies have revealed that the aging process is linked to significant epigenetic changes in the chromatin landscape, e.g. global demethylation of DNA and histones and increase in histone acetylation. Interestingly, recent studies have revealed that the demethylases of DNA (TET1-3) and histone lysines (KDM2-7) are members of 2-oxoglutarate-dependent dioxygenases (2-OGDO). The 2-OGDO enzymes are activated by oxygen, iron and the major Krebs cycle intermediate, 2-oxoglutarate, whereas they are inhibited by succinate and fumarate. Considering the endosymbiont origin of mitochondria, it is not surprising that Krebs cycle metabolites can control the gene expression of host cell by modifying the epigenetic landscape of chromatin. It seems that age-related disturbances in mitochondrial metabolism can induce epigenetic reprogramming, which promotes the appearance of senescent phenotype and degenerative diseases.}, }
@article {pmid24696316, year = {2014}, author = {Park, MS and Takeda, M}, title = {Cloning of PaAtg8 and roles of autophagy in adaptation to starvation with respect to the fat body and midgut of the Americana cockroach, Periplaneta americana.}, journal = {Cell and tissue research}, volume = {356}, number = {2}, pages = {405-416}, doi = {10.1007/s00441-014-1802-3}, pmid = {24696316}, issn = {1432-0878}, mesh = {Acid Phosphatase/biosynthesis ; Adaptor Proteins, Signal Transducing/biosynthesis/*genetics ; Adipocytes ; Amino Acid Sequence ; Amino Acids/biosynthesis/metabolism ; Animals ; Autophagy/*physiology ; Base Sequence ; Cloning, Molecular ; Fat Body/*metabolism ; Lysosomes/enzymology ; Microfilament Proteins/biosynthesis/genetics ; Molecular Sequence Data ; Nerve Tissue Proteins/biosynthesis/genetics ; Periplaneta/*metabolism ; Sequence Alignment ; *Starvation ; Uric Acid/metabolism ; }, abstract = {Starvation, in particular amino acid deprivation, induces autophagy in trophocytes (adipocytes), the major component of the fat body cell types, in the larvae of Drosophila melanogaster. However, the fat body of cockroach has two additional cell types: urocytes depositing uric acid in urate vacuoles as a nitrogen resource and mycetocytes harboring an endosymbiont, Blattabacterium cuenoti, which can synthesize amino acids from the metabolites of the stored uric acid. These cells might complement the roles of autophagy in recycling amino acids in the fat body or other organs of cockroaches under starvation. We investigate the presence of autophagy in tissues such as the fat body and midgut of the American cockroach, Periplaneta americana, under starvation by immunoblotting with antibody against Atg8, a ubiquitin-like protein required for the formation of autophagosomes and by electron microscopy. Corresponding changes in acid phosphatase activity were also investigated as representing lysosome activity. Starvation increased the level of an autophagic marker, Atg8-II, in both the tissues, extensively stimulating the formation of autophagic compartments in trophocytes of the fat body and columnar cells of the midgut for over 2 weeks. Acid phosphatase showed no significant increase in the fat body of the starved cockroaches but was higher in the midgut of the continuously fed animals. Thus, a distinct autophagic mechanism operates in these tissues under starvation of 2 weeks and longer. The late induction of autophagy implies exhaustion of the stored uric acid in the fat body. High activity of acid phosphatase in the midgut of the fed cockroaches might represent enhanced assimilation and not an autophagy-related function.}, }
@article {pmid24691961, year = {2014}, author = {Koonin, EV and Yutin, N}, title = {The dispersed archaeal eukaryome and the complex archaeal ancestor of eukaryotes.}, journal = {Cold Spring Harbor perspectives in biology}, volume = {6}, number = {4}, pages = {a016188}, pmid = {24691961}, issn = {1943-0264}, support = {//Intramural NIH HHS/United States ; }, mesh = {Archaea/*genetics ; Biological Evolution ; Cell Division ; Cytoskeleton/diagnostic imaging/physiology ; Eukaryota/genetics ; *Genes, Archaeal ; Genome ; *Phylogeny ; RNA Interference ; Signal Transduction ; Ubiquitin/metabolism/physiology ; Ultrasonography ; }, abstract = {The ancestral set of eukaryotic genes is a chimera composed of genes of archaeal and bacterial origins thanks to the endosymbiosis event that gave rise to the mitochondria and apparently antedated the last common ancestor of the extant eukaryotes. The proto-mitochondrial endosymbiont is confidently identified as an α-proteobacterium. In contrast, the archaeal ancestor of eukaryotes remains elusive, although evidence is accumulating that it could have belonged to a deep lineage within the TACK (Thaumarchaeota, Aigarchaeota, Crenarchaeota, Korarchaeota) superphylum of the Archaea. Recent surveys of archaeal genomes show that the apparent ancestors of several key functional systems of eukaryotes, the components of the archaeal "eukaryome," such as ubiquitin signaling, RNA interference, and actin-based and tubulin-based cytoskeleton structures, are identifiable in different archaeal groups. We suggest that the archaeal ancestor of eukaryotes was a complex form, rooted deeply within the TACK superphylum, that already possessed some quintessential eukaryotic features, in particular, a cytoskeleton, and perhaps was capable of a primitive form of phagocytosis that would facilitate the engulfment of potential symbionts. This putative group of Archaea could have existed for a relatively short time before going extinct or undergoing genome streamlining, resulting in the dispersion of the eukaryome. This scenario might explain the difficulty with the identification of the archaeal ancestor of eukaryotes despite the straightforward detection of apparent ancestors to many signature eukaryotic functional systems.}, }
@article {pmid24691960, year = {2014}, author = {McFadden, GI}, title = {Origin and evolution of plastids and photosynthesis in eukaryotes.}, journal = {Cold Spring Harbor perspectives in biology}, volume = {6}, number = {4}, pages = {a016105}, pmid = {24691960}, issn = {1943-0264}, mesh = {*Biological Evolution ; Cyanobacteria/genetics/physiology ; *Photosynthesis ; Phylogeny ; Plastids/genetics/*physiology ; RNA, Ribosomal/chemistry ; Symbiosis ; }, abstract = {Recent progress in understanding the origins of plastids from endosymbiotic cyanobacteria is reviewed. Establishing when during geological time the endosymbiosis occurred remains elusive, but progress has been made in defining the cyanobacterial lineage most closely related to plastids, and some mechanistic insight into the possible existence of cryptic endosymbioses perhaps involving Chlamydia-like infections of the host have also been presented. The phylogenetic affinities of the host remain obscure. The existence of a second lineage of primary plastids in euglyphid amoebae has now been confirmed, but the quasipermanent acquisition of plastids by animals has been shown to be more ephemeral than initially suspected. A new understanding of how plastids have been integrated into their hosts by transfer of photosynthate, by endosymbiotic gene transfer and repatriation of gene products back to the endosymbiont, and by regulation of endosymbiont division is presented in context.}, }
@article {pmid24686935, year = {2014}, author = {Normark, BB and Ross, L}, title = {Genetic conflict, kin and the origins of novel genetic systems.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {369}, number = {1642}, pages = {20130364}, pmid = {24686935}, issn = {1471-2970}, mesh = {Adaptation, Biological/*genetics ; Animals ; *Biological Evolution ; *Environment ; Female ; *Genetic Fitness ; *Genetics, Population ; Germ Cells/physiology ; Inheritance Patterns/*genetics ; Male ; *Models, Genetic ; Ploidies ; Sex Factors ; Symbiosis ; }, abstract = {Genetic conflict may have played an important role in the evolution of novel genetic systems. The ancestral system of eumendelian genetics is highly symmetrical. Those derived from it (e.g. thelytokous parthenogenesis, haplodiploidy and parent-specific allele expression) are more asymmetrical in the genetic role played by maternal versus paternal alleles. These asymmetries may have arisen from maternal-paternal genetic conflict, or cytonuclear conflict, or from an interaction between them. Asymmetric genetic systems are much more common in terrestrial and freshwater taxa than in marine taxa. We suggest three reasons for this, based on the relative inhospitability of terrestrial environments to three types of organism: (i) pathogens-departure from the marine realm meant escape from many pathogens and parasites, reducing the need for sexual reproduction; (ii) symbionts-symbionts are no more important in the terrestrial realm than the marine realm but are more likely to be obligately intracellular and vertically transmitted, making them more likely to disrupt their host's genetic systems; (iii) Gametes and embryos-because neither gametes nor embryos can be shed into air as easily as into seawater, the mother's body is a more important environment for both types of organisms in the terrestrial realm than in the marine realm. This environment of asymmetric kinship (with neighbours more closely related by maternal alleles than by paternal alleles) may have helped to drive asymmetries in expression and transmission.}, }
@article {pmid24685011, year = {2014}, author = {Foster, JM and Landmann, F and Ford, L and Johnston, KL and Elsasser, SC and Schulte-Hostedde, AI and Taylor, MJ and Slatko, BE}, title = {Absence of Wolbachia endobacteria in the human parasitic nematode Dracunculus medinensis and two related Dracunculus species infecting wildlife.}, journal = {Parasites &amp; vectors}, volume = {7}, number = {}, pages = {140}, pmid = {24685011}, issn = {1756-3305}, mesh = {Animals ; Animals, Wild ; DNA, Bacterial/genetics/isolation &amp; purification ; Dracunculiasis/epidemiology/parasitology/*veterinary ; Dracunculus Nematode/*microbiology ; Female ; Ghana/epidemiology ; Humans ; Mink/parasitology ; Ontario/epidemiology ; Otters/parasitology ; Species Specificity ; Wolbachia/*isolation &amp; purification ; }, abstract = {BACKGROUND: Wolbachia endosymbionts are a proven target for control of human disease caused by filarial nematodes. However, little is known about the occurrence of Wolbachia in taxa closely related to the superfamily Filarioidea. Our study addressed the status of Wolbachia presence in members of the superfamily Dracunculoidea by screening the human parasite Dracunculus medinensis and related species from wildlife for Wolbachia.<br><br>FINDINGS: D. medinensis, D. lutrae and D. insignis specimens were all negative for Wolbachia colonization by PCR screening for the Wolbachia ftsZ, 16S rRNA and Wolbachia surface protein (wsp) sequences. The quality and purity of the DNA preparations was confirmed by amplification of nematode 18S rRNA and cytochrome c oxidase subunit I sequences. Furthermore, Wolbachia endobacteria were not detected by whole mount fluorescence staining, or by immunohistochemistry using a Wolbachia-specific antiserum. In contrast, positive control Brugia malayi worms were shown to harbour Wolbachia by PCR, fluorescence staining and immunohistochemistry.<br><br>CONCLUSIONS: Three examined species of Dracunculus showed no evidence of Wolbachia endobacteria. This supports that members of the superfamily Dracunculoidea are free of Wolbachia. Within the order Spirurida, these endosymbionts appear restricted to the Filarioidea.}, }
@article {pmid24673824, year = {2014}, author = {Boivin, T and Henri, H and Vavre, F and Gidoin, C and Veber, P and Candau, JN and Magnoux, E and Roques, A and Auger-Rozenberg, MA}, title = {Epidemiology of asexuality induced by the endosymbiotic Wolbachia across phytophagous wasp species: host plant specialization matters.}, journal = {Molecular ecology}, volume = {23}, number = {9}, pages = {2362-2375}, doi = {10.1111/mec.12737}, pmid = {24673824}, issn = {1365-294X}, mesh = {Animals ; Bacterial Typing Techniques ; Bayes Theorem ; Female ; Genetics, Population ; Likelihood Functions ; Molecular Sequence Data ; Multilocus Sequence Typing ; *Parthenogenesis ; Phylogeny ; *Symbiosis ; Wasps/*microbiology ; Wolbachia/classification/*genetics ; }, abstract = {Among eukaryotes, sexual reproduction is by far the most predominant mode of reproduction. However, some systems maintaining sexuality appear particularly labile and raise intriguing questions on the evolutionary routes to asexuality. Thelytokous parthenogenesis is a form of spontaneous loss of sexuality leading to strong distortion of sex ratio towards females and resulting from mutation, hybridization or infection by bacterial endosymbionts. We investigated whether ecological specialization is a likely mechanism of spread of thelytoky within insect communities. Focusing on the highly specialized genus Megastigmus (Hymenoptera: Torymidae), we first performed a large literature survey to examine the distribution of thelytoky in these wasps across their respective obligate host plant families. Second, we tested for thelytoky caused by endosymbionts by screening in 15 arrhenotokous and 10 thelytokous species for Wolbachia, Cardinium, Arsenophonus and Rickettsia endosymbionts and by performing antibiotic treatments. Finally, we performed phylogenetic reconstructions using multilocus sequence typing (MLST) to examine the evolution of endosymbiont-mediated thelytoky in Megastigmus and its possible connections to host plant specialization. We demonstrate that thelytoky evolved from ancestral arrhenotoky through the horizontal transmission and the fixation of the parthenogenesis-inducing Wolbachia. We find that ecological specialization in Wolbachia's hosts was probably a critical driving force for Wolbachia infection and spread of thelytoky, but also a constraint. Our work further reinforces the hypothesis that community structure of insects is a major driver of the epidemiology of endosymbionts and that competitive interactions among closely related species may facilitate their horizontal transmission.}, }
@article {pmid24671745, year = {2014}, author = {Kenyon, LJ and Sabree, ZL}, title = {Obligate insect endosymbionts exhibit increased ortholog length variation and loss of large accessory proteins concurrent with genome shrinkage.}, journal = {Genome biology and evolution}, volume = {6}, number = {4}, pages = {763-775}, pmid = {24671745}, issn = {1759-6653}, mesh = {Animals ; Bacterial Proteins/*genetics ; Enterobacteriaceae/*genetics ; *Evolution, Molecular ; Flavobacteriaceae/*genetics ; Genome, Bacterial/*physiology ; Insecta/*microbiology ; Symbiosis/*physiology ; }, abstract = {Extreme genome reduction has been observed in obligate intracellular insect mutualists and is an assumed consequence of fixed, long-term host isolation. Rapid accumulation of mutations and pseudogenization of genes no longer vital for an intracellular lifestyle, followed by deletion of many genes, are factors that lead to genome reduction. Size reductions in individual genes due to small-scale deletions have also been implicated in contributing to overall genome shrinkage. Conserved protein functional domains are expected to exhibit low tolerance for mutations and therefore remain relatively unchanged throughout protein length reduction while nondomain regions, presumably under less selective pressures, would shorten. This hypothesis was tested using orthologous protein sets from the Flavobacteriaceae (phylum: Bacteroidetes) and Enterobacteriaceae (subphylum: Gammaproteobacteria) families, each of which includes some of the smallest known genomes. Upon examination of protein, functional domain, and nondomain region lengths, we found that proteins were not uniformly shrinking with genome reduction, but instead increased length variability and variability was observed in both the functional domain and nondomain regions. Additionally, as complete gene loss also contributes to overall genome shrinkage, we found that the largest proteins in the proteomes of nonhost-restricted bacteroidetial and gammaproteobacterial species often were inferred to be involved in secondary metabolic processes, extracellular sensing, or of unknown function. These proteins were absent in the proteomes of obligate insect endosymbionts. Therefore, loss of genes encoding large proteins not required for host-restricted lifestyles in obligate endosymbiont proteomes likely contributes to extreme genome reduction to a greater degree than gene shrinkage.}, }
@article {pmid24654979, year = {2014}, author = {Elzinga, DA and De Vos, M and Jander, G}, title = {Suppression of plant defenses by a Myzus persicae (green peach aphid) salivary effector protein.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {27}, number = {7}, pages = {747-756}, pmid = {24654979}, issn = {0894-0282}, support = {T32 GM008500/GM/NIGMS NIH HHS/United States ; 5T32GM008500/GM/NIGMS NIH HHS/United States ; BB/J004553/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/*metabolism ; Arabidopsis/physiology ; Buchnera/physiology ; Gene Expression Regulation, Plant/physiology ; Insect Proteins/*metabolism/*pharmacology ; Plant Leaves/drug effects ; Plant Proteins/genetics/metabolism ; Plants, Genetically Modified ; Reproduction ; Tobacco/genetics/*metabolism ; }, abstract = {The complex interactions between aphids and their host plant are species-specific and involve multiple layers of recognition and defense. Aphid salivary proteins, which are released into the plant during phloem feeding, are a likely mediator of these interactions. In an approach to identify aphid effectors that facilitate feeding from host plants, eleven Myzus persicae (green peach aphid) salivary proteins and the GroEL protein of Buchnera aphidicola, a bacterial endosymbiont of this aphid species, were expressed transiently in Nicotiana tabacum (tobacco). Whereas two salivary proteins increased aphid reproduction, expression of three other aphid proteins and GroEL significantly decreased aphid reproduction on N. tabacum. These effects were recapitulated in stable transgenic Arabidopsis thaliana plants. Further experiments with A. thaliana expressing Mp55, a salivary protein that increased aphid reproduction, showed lower accumulation of 4-methoxyindol-3-ylmethylglucosinolate, callose and hydrogen peroxide in response to aphid feeding. Mp55-expressing plants also were more attractive for aphids in choice assays. Silencing Mp55 gene expression in M. persicae using RNA interference approaches reduced aphid reproduction on N. tabacum, A. thaliana, and N. benthamiana. Together, these results demonstrate a role for Mp55, a protein with as-yet-unknown molecular function, in the interaction of M. persicae with its host plants.}, }
@article {pmid24646792, year = {2014}, author = {Gomaa, F and Kosakyan, A and Heger, TJ and Corsaro, D and Mitchell, EA and Lara, E}, title = {One alga to rule them all: unrelated mixotrophic testate amoebae (amoebozoa, rhizaria and stramenopiles) share the same symbiont (trebouxiophyceae).}, journal = {Protist}, volume = {165}, number = {2}, pages = {161-176}, doi = {10.1016/j.protis.2014.01.002}, pmid = {24646792}, issn = {1618-0941}, mesh = {Amoebozoa/*parasitology ; Chlorophyta/*classification/enzymology/genetics/*physiology ; Electron Transport Complex IV/genetics ; Molecular Sequence Data ; Rhizaria/*parasitology ; Ribulose-Bisphosphate Carboxylase/genetics ; Sequence Analysis, DNA ; Stramenopiles/*parasitology ; *Symbiosis ; }, abstract = {Endosymbiosis is a central and much studied process in the evolution of eukaryotes. While plastid evolution in eukaryotic algae has been extensively studied, much less is known about the evolution of mixotrophy in amoeboid protists, which has been found in three of the five super groups of Eukaryotes. We identified the green endosymbionts in four obligate mixotrophic testate amoeba species belonging to three major eukaryotic clades, Hyalosphenia papilio and Heleopera sphagni (Amoebozoa: Arcellinida), Placocista spinosa (Rhizaria: Euglyphida), and Archerella flavum (Stramenopiles: Labyrinthulomycetes) based on rbcL (ribulose-1,5-diphosphate carboxylase/oxygenase large subunit) gene sequences. We further investigated whether there were different phylotypes of algal endosymbionts within single H. papilio cells and the degree of host-symbiont specificity by amplifying two genes: COI (mitochondrial cytochrome oxydase subunit 1) from the testate amoeba host, and rbcL from the endosymbiont. Results show that all studied endosymbionts belong to genus Chlorella sensu stricto, closely related to Paramecium bursaria Chlorella symbionts, some lichen symbionts and also several free-living algae. Most rbcL gene sequences derived from symbionts from all testate amoeba species were almost identical (at most 3 silent nucleotides difference out of 780 bp) and were assigned to a new Trebouxiophyceae taxon we named TACS (Testate Amoeba Chlorella Symbionts). This "one alga fits all mixotrophic testate amoeba" pattern suggests that photosynthetic symbionts have pre-adaptations to endosymbiosis and colonise diverse hosts from a free-living stage.}, }
@article {pmid24627993, year = {2014}, author = {van der Kooi, CJ and Schwander, T}, title = {Evolution of asexuality via different mechanisms in grass thrips (thysanoptera: Aptinothrips).}, journal = {Evolution; international journal of organic evolution}, volume = {68}, number = {7}, pages = {1883-1893}, doi = {10.1111/evo.12402}, pmid = {24627993}, issn = {1558-5646}, mesh = {Animals ; *Evolution, Molecular ; Female ; Reproduction, Asexual/*genetics ; Symbiosis ; Thysanoptera/*genetics/microbiology/physiology ; Wolbachia/pathogenicity ; }, abstract = {Asexual lineages can derive from sexual ancestors via different mechanisms and at variable rates, which affects the diversity of the asexual population and thereby its ecological success. We investigated the variation and evolution of reproductive systems in Aptinothrips, a genus of grass thrips comprising four species. Extensive population surveys and breeding experiments indicated sexual reproduction in A. elegans, asexuality in A. stylifer and A. karnyi, and both sexual and asexual lineages in A. rufus. Asexuality in A. stylifer and A. rufus coincides with a worldwide distribution, with sexual A. rufus lineages confined to a limited area. Inference of molecular phylogenies and antibiotic treatment revealed different causes of asexuality in different species. Asexuality in A. stylifer and A. karnyi has most likely genetic causes, while it is induced by endosymbionts in A. rufus. Endosymbiont-community characterization revealed presence of Wolbachia, and lack of other bacteria known to manipulate host reproduction. However, only 69% asexual A. rufus females are Wolbachia-infected, indicating that either an undescribed endosymbiont causes asexuality in this species or that Wolbachia was lost in several lineages that remained asexual. These results open new perspectives for studies on the maintenance of mixed sexual and asexual reproduction in natural populations.}, }
@article {pmid24625648, year = {2014}, author = {Gibbin, EM and Putnam, HM and Davy, SK and Gates, RD}, title = {Intracellular pH and its response to CO2-driven seawater acidification in symbiotic versus non-symbiotic coral cells.}, journal = {The Journal of experimental biology}, volume = {217}, number = {Pt 11}, pages = {1963-1969}, doi = {10.1242/jeb.099549}, pmid = {24625648}, issn = {1477-9145}, mesh = {Acidosis ; Animals ; Anthozoa/metabolism/*physiology ; Dinoflagellida/*metabolism ; Homeostasis ; Hydrogen-Ion Concentration ; Photosynthesis ; Seawater/*chemistry ; Symbiosis/*physiology ; }, abstract = {Regulating intracellular pH (pHi) is critical for optimising the metabolic activity of corals, yet the mechanisms involved in pH regulation and the buffering capacity within coral cells are not well understood. Our study investigated how the presence of symbiotic dinoflagellates affects the response of pHi to PCO2-driven seawater acidification in cells isolated from Pocillopora damicornis. Using the fluorescent dye BCECF-AM, in conjunction with confocal microscopy, we simultaneously characterised the pHi response in host coral cells and their dinoflagellate symbionts, in symbiotic and non-symbiotic states under saturating light, with and without the photosynthetic inhibitor DCMU. Each treatment was run under control (pH 7.8) and CO2-acidified seawater conditions (decreasing pH from 7.8 to 6.8). After 105 min of CO2 addition, by which time the external pH (pHe) had declined to 6.8, the dinoflagellate symbionts had increased their pHi by 0.5 pH units above control levels when in the absence of DCMU. In contrast, in both symbiotic and non-symbiotic host coral cells, 15 min of CO2 addition (0.2 pH unit drop in pHe) led to cytoplasmic acidosis equivalent to 0.3-0.4 pH units irrespective of whether DCMU was present. Despite further seawater acidification over the duration of the experiment, the pHi of non-symbiotic coral cells did not change, though in host cells containing a symbiont cell the pHi recovered to control levels when photsynthesis was not inhibited. This recovery was negated when cells were incubated with DCMU. Our results reveal that photosynthetic activity of the endosymbiont is tightly coupled with the ability of the host cell to recover from cellular acidosis after exposure to high CO2/low pH.}, }
@article {pmid24619863, year = {2015}, author = {Mathenge, CW and Riegler, M and Beattie, GA and Spooner-Hart, RN and Holford, P}, title = {Genetic variation amongst biotypes of Dactylopius tomentosus.}, journal = {Insect science}, volume = {22}, number = {3}, pages = {360-374}, doi = {10.1111/1744-7917.12120}, pmid = {24619863}, issn = {1744-7917}, mesh = {Animals ; Biological Control Agents ; Cactaceae/classification/*parasitology ; DNA, Bacterial/genetics ; Electron Transport Complex IV/genetics ; Genes, Mitochondrial ; Genetic Variation ; Hemiptera/*genetics/*microbiology ; Host-Parasite Interactions ; Phylogeny ; Wolbachia/genetics ; }, abstract = {The tomentose cochineal scale insect, Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae), is an important biological control agent against invasive species of Cylindropuntia (Caryophyllales: Cactaceae). Recent studies have demonstrated that this scale is composed of host-affiliated biotypes with differential host specificity and fitness on particular host species. We investigated genetic variation and phylogenetic relationships among D. tomentosus biotypes and provenances to examine the possibility that genetic diversity may be related to their host-use pattern, and whether their phylogenetic relationships would give insights into taxonomic relatedness of their host plants. Nucleotide sequence comparison was accomplished using sequences of the mitochondrial cytochrome c oxidase I (COI) gene. Sequences of individuals from the same host plant within a region were identical and characterized by a unique haplotype. Individuals belonging to the same biotype but from different regions had similar haplotypes. However, haplotypes were not shared between different biotypes. Phylogenetic analysis grouped the monophyletic D. tomentosus into 3 well-resolved clades of biotypes. The phylogenetic relationships and clustering of biotypes corresponded with known taxonomic relatedness of their hosts. Two biotypes, Fulgida and Mamillata, tested positive for Wolbachia (α-Proteobacteria), a common endosymbiont of insects. The Wolbachia sequences were serendipitously detected by using insect-specific COI DNA barcoding primers and are most similar to Wolbachia Supergroup F strains. This study is the first molecular characterization of cochineal biotypes that, together with Wolbachia sequences, contribute to the better identification of the biotypes of cochineal insects and to the biological control of cacti using host-specific biotypes of the scale.}, }
@article {pmid24618033, year = {2015}, author = {Zug, R and Hammerstein, P}, title = {Bad guys turned nice? A critical assessment of Wolbachia mutualisms in arthropod hosts.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {90}, number = {1}, pages = {89-111}, doi = {10.1111/brv.12098}, pmid = {24618033}, issn = {1469-185X}, mesh = {Animals ; Arthropods/*microbiology ; Biological Evolution ; Host-Pathogen Interactions ; Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia are the most abundant bacterial endosymbionts among arthropods. Although maternally inherited, they do not conform to the widespread view that vertical transmission inevitably selects for beneficial symbionts. Instead, Wolbachia are notorious for their reproductive parasitism which, although lowering host fitness, ensures their spread. However, even for reproductive parasites it can pay to enhance host fitness. Indeed, there is a recent upsurge of reports on Wolbachia-associated fitness benefits. Therefore, the question arises how such instances of mutualism are related to the phenotypes of reproductive parasitism. Here, we review the evidence of Wolbachia mutualisms in arthropods, including both facultative and obligate relationships, and critically assess their biological relevance. Although many studies report anti-pathogenic effects of Wolbachia, few actually prove these effects to be relevant to field conditions. We further show that Wolbachia frequently have beneficial and detrimental effects at the same time, and that reproductive manipulations and obligate mutualisms may share common mechanisms. These findings undermine the idea of a clear-cut distinction between Wolbachia mutualism and parasitism. In general, both facultative and obligate mutualisms can have a strong, and sometimes unforeseen, impact on the ecology and evolution of Wolbachia and their arthropod hosts. Acknowledging this mutualistic potential might be the key to a better understanding of some unresolved issues in the study of Wolbachia-host interactions.}, }
@article {pmid24617944, year = {2014}, author = {Zhang, B and Edwards, O and Kang, L and Fuller, S}, title = {A multi-genome analysis approach enables tracking of the invasion of a single Russian wheat aphid (Diuraphis noxia) clone throughout the New World.}, journal = {Molecular ecology}, volume = {23}, number = {8}, pages = {1940-1951}, doi = {10.1111/mec.12714}, pmid = {24617944}, issn = {1365-294X}, mesh = {Animals ; Aphids/*genetics ; Buchnera/genetics ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Female ; Gene Flow ; Genetic Variation ; *Genetics, Population ; Haplotypes ; *Introduced Species ; Kenya ; Microsatellite Repeats ; Russia ; South Africa ; Symbiosis ; Syria ; Triticum ; Turkey ; }, abstract = {This study investigated the population genetics, demographic history and pathway of invasion of the Russian wheat aphid (RWA) from its native range in Central Asia, the Middle East and Europe to South Africa and the Americas. We screened microsatellite markers, mitochondrial DNA and endosymbiont genes in 504 RWA clones from nineteen populations worldwide. Following pathway analyses of microsatellite and endosymbiont data, we postulate that Turkey and Syria were the most likely sources of invasion to Kenya and South Africa, respectively. Furthermore, we found that one clone transferred between South Africa and the Americas was most likely responsible for the New World invasion. Finally, endosymbiont DNA was found to be a high-resolution population genetic marker, extremely useful for studies of invasion over a relatively short evolutionary history time frame. This study has provided valuable insights into the factors that may have facilitated the recent global invasion by this damaging pest.}, }
@article {pmid24615955, year = {2014}, author = {Moreira, D and López-García, P}, title = {The rise and fall of Picobiliphytes: how assumed autotrophs turned out to be heterotrophs.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {36}, number = {5}, pages = {468-474}, pmid = {24615955}, issn = {1521-1878}, support = {322669/ERC_/European Research Council/International ; }, mesh = {*Autotrophic Processes ; Base Sequence ; Eukaryota/genetics/*metabolism ; Genomics ; *Heterotrophic Processes ; Oceans and Seas ; Phylogeny ; Plastids/genetics ; Single-Cell Analysis ; }, abstract = {Algae are significant members of Earth's biodiversity. Having been studied for a long time, the discovery of new algal phyla is extremely unusual. Recently, the enigmatic "Picobiliphyta," a group of uncultured eukaryotes unveiled using molecular tools, were claimed to represent an unrecognized early branching algal lineage with a nucleomorph (remnant nucleus of a secondary algal endosymbiont) in their plastids. However, subsequent studies rejected the presence of a nucleomorph, and single-cell genomic studies failed to detect any plastid-related genes, ruling out the possibility of plastid occurrence. The isolation of the first "picobiliphyte," Picomonas judraskeda, a tiny organism that feeds on very small (<150 nm) organic particles, came as final proof of their non-photosynthetic lifestyle. Consequently, the group has been renamed Picozoa. The passage from "picobiliphytes" to "picozoa" illustrates the crucial role that classical protistology should play to provide sound biological context for the wealth of data produced by modern molecular techniques.}, }
@article {pmid24612422, year = {2014}, author = {Duron, O and Schneppat, UE and Berthomieu, A and Goodman, SM and Droz, B and Paupy, C and Nkoghe, JO and Rahola, N and Tortosa, P}, title = {Origin, acquisition and diversification of heritable bacterial endosymbionts in louse flies and bat flies.}, journal = {Molecular ecology}, volume = {23}, number = {8}, pages = {2105-2117}, doi = {10.1111/mec.12704}, pmid = {24612422}, issn = {1365-294X}, mesh = {Animals ; *Biological Evolution ; DNA, Bacterial/genetics ; Diptera/*microbiology ; Gammaproteobacteria/*genetics ; Glossinidae/microbiology ; Molecular Sequence Data ; *Phylogeny ; *Symbiosis ; }, abstract = {The γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus and like organisms, ALOs) are emerging as a novel clade of endosymbionts, which are exceptionally widespread in insects. The biology of ALOs is, however, in most cases entirely unknown, and it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination of the presence, the diversity and the evolutionary history of ALOs in 25 related species of blood-feeding flies: tsetse flies (Glossinidae), louse flies (Hippoboscidae) and bat flies (Nycteribiidae and Streblidae). While these endosymbionts were not found in tsetse flies, we identify louse flies and bat flies as harbouring the highest diversity of ALO strains reported to date, including a novel ALO clade, as well as Arsenophonus and the recently described Candidatus Aschnera chinzeii. We further show that the origin of ALO endosymbioses extends deep into the evolutionary past of louse flies and bat flies, and that it probably played a major role in the ecological specialization of their hosts. The evolutionary history of ALOs is notably complex and was shaped by both vertical transmission and horizontal transfers with frequent host turnover and apparent symbiont replacement in host lineages. In particular, ALOs have evolved repeatedly and independently close relationships with diverse groups of louse flies and bat flies, as well as phylogenetically more distant insect families, suggesting that ALO endosymbioses are exceptionally dynamic systems.}, }
@article {pmid24612104, year = {2014}, author = {Lewis, SE and Rice, A and Hurst, GD and Baylis, M}, title = {First detection of endosymbiotic bacteria in biting midges Culicoides pulicaris and Culicoides punctatus, important Palaearctic vectors of bluetongue virus.}, journal = {Medical and veterinary entomology}, volume = {28}, number = {4}, pages = {453-456}, doi = {10.1111/mve.12055}, pmid = {24612104}, issn = {1365-2915}, mesh = {Animals ; Bacteroidaceae/*genetics/*isolation &amp; purification ; Bluetongue virus/*physiology ; Ceratopogonidae/*microbiology ; Female ; Insect Vectors/*microbiology/*virology ; Male ; Phylogeny ; Species Specificity ; Symbiosis ; }, abstract = {Heritable bacteria have been highlighted as important components of vector biology, acting as required symbionts with an anabolic role, altering competence for disease transmission, and affecting patterns of gene flow by altering cross compatibility. In this paper, we tested eight U.K. species of Culicoides (Diptera: Ceratopogonidae) midge for the presence of five genera of endosymbiotic bacteria: Cardinium (Bacteroidales: Bacteroidaceae); Wolbachia (Rickettsiales: Rickettsiaceae); Spiroplasma (Entomoplasmatales: Spiroplasmataceae); Arsenophonus (Enterobacteriales: Enterobacteriaceae), and Rickettsia (Rickettsiales: Rickettsiaceae). Cardinium spp. were detected in both sexes of Culicoides pulicaris and Culicoides punctatus, two known vectors of bluetongue virus. Cardinium spp. were not detected in any other species, including the Culicoides obsoletus group, the main vector of bluetongue and Schmallenberg viruses in northern Europe. The other endosymbionts were not detected in any Culicoides species. The Cardinium strain detected in U.K. Culicoides species is very closely related to the Candidatus Cardinium hertigii group C, previously identified in Culicoides species in Asia. Further, we infer that the symbiont is not a sex ratio distorter and shows geographic variation in prevalence within a species. Despite its detection in several species of Culicoides that vector arboviruses worldwide, the absence of Cardinium in the C. obsoletus group suggests that infections of these symbionts may not be necessary to the arboviral vector competence of biting midges.}, }
@article {pmid24611069, year = {2014}, author = {Yagi, Y and Shiina, T}, title = {Recent advances in the study of chloroplast gene expression and its evolution.}, journal = {Frontiers in plant science}, volume = {5}, number = {}, pages = {61}, pmid = {24611069}, issn = {1664-462X}, abstract = {Chloroplasts are semiautonomous organelles which possess their own genome and gene expression system. However, extant chloroplasts contain only limited coding information, and are dependent on a large number of nucleus-encoded proteins. During plant evolution, chloroplasts have lost most of the prokaryotic DNA-binding proteins and transcription regulators that were present in the original endosymbiont. Thus, chloroplasts have a unique hybrid transcription system composed of the remaining prokaryotic components, such as a prokaryotic RNA polymerase as well as nucleus-encoded eukaryotic components. Recent proteomic and transcriptomic analyses have provided insights into chloroplast transcription systems and their evolution. Here, we review chloroplast-specific transcription systems, focusing on the multiple RNA polymerases, eukaryotic transcription regulators in chloroplasts, chloroplast promoters, and the dynamics of chloroplast nucleoids.}, }
@article {pmid24610838, year = {2014}, author = {Rosas-Pérez, T and Rosenblueth, M and Rincón-Rosales, R and Mora, J and Martínez-Romero, E}, title = {Genome sequence of "Candidatus Walczuchella monophlebidarum" the flavobacterial endosymbiont of Llaveia axin axin (Hemiptera: Coccoidea: Monophlebidae).}, journal = {Genome biology and evolution}, volume = {6}, number = {3}, pages = {714-726}, pmid = {24610838}, issn = {1759-6653}, mesh = {Animals ; Cloning, Molecular ; DNA, Bacterial/genetics ; Flavobacterium/classification/*genetics ; *Genome, Bacterial ; Genomics ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Scale insects (Hemiptera: Coccoidae) constitute a very diverse group of sap-feeding insects with a large diversity of symbiotic associations with bacteria. Here, we present the complete genome sequence, metabolic reconstruction, and comparative genomics of the flavobacterial endosymbiont of the giant scale insect Llaveia axin axin. The gene repertoire of its 309,299 bp genome was similar to that of other flavobacterial insect endosymbionts though not syntenic. According to its genetic content, essential amino acid biosynthesis is likely to be the flavobacterial endosymbiont's principal contribution to the symbiotic association with its insect host. We also report the presence of a γ-proteobacterial symbiont that may be involved in waste nitrogen recycling and also has amino acid biosynthetic capabilities that may provide metabolic precursors to the flavobacterial endosymbiont. We propose "Candidatus Walczuchella monophlebidarum" as the name of the flavobacterial endosymbiont of insects from the Monophlebidae family.}, }
@article {pmid24605461, year = {2014}, author = {Budachetri, K and Browning, RE and Adamson, SW and Dowd, SE and Chao, CC and Ching, WM and Karim, S}, title = {An insight into the microbiome of the Amblyomma maculatum (Acari: Ixodidae).}, journal = {Journal of medical entomology}, volume = {51}, number = {1}, pages = {119-129}, pmid = {24605461}, issn = {0022-2585}, support = {R15 AI099910/AI/NIAID NIH HHS/United States ; P20RR016476/RR/NCRR NIH HHS/United States ; P20 RR016476/RR/NCRR NIH HHS/United States ; P20 GM103476/GM/NIGMS NIH HHS/United States ; AI099919/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Arthropod Vectors/*microbiology ; Female ; Host-Pathogen Interactions ; Ixodidae/*microbiology ; Male ; Mice ; *Microbiota ; Rabbits ; Rickettsia/*isolation &amp; purification ; }, abstract = {The aim of this study was to survey the bacterial diversity of Amblyomma maculatum Koch, 1844, and characterize its infection with Rickettsia parkeri. Pyrosequencing of the bacterial 16S rRNA was used to determine the total bacterial population in A. maculatum. Pyrosequencing analysis identified Rickettsia in A. maculatum midguts, salivary glands, and saliva, which indicates successful trafficking in the arthropod vector. The identity of Rickettsia spp. was determined based on sequencing the rickettsial outer membrane protein A (rompA) gene. The sequence homology search revealed the presence of R. parkeri, Rickettsia amblyommii, and Rickettsia endosymbiont ofA. maculatum in midgut tissues, whereas the only rickettsia detected in salivary glands was R. parkeri, suggesting it is unique in its ability to migrate from midgut to salivary glands, and colonize this tissue before dissemination to the host. Owing to its importance as an emerging infectious disease, the R. parkeri pathogen burden was quantified by a rompB-based quantitative polymerase chain reaction (qPCR) assay and the diagnostic effectiveness of using R. parkeri polyclonal antibodies in tick tissues was tested. Together, these data indicate that field-collected A. maculatum had a R. parkeri infection rate of 12-32%. This study provides an insight into the A. maculatum microbiome and confirms the presence of R. parkeri, which will serve as the basis for future tick and microbiome interaction studies.}, }
@article {pmid24603278, year = {2014}, author = {Hirakawa, Y and Suzuki, S and Archibald, JM and Keeling, PJ and Ishida, K}, title = {Overexpression of molecular chaperone genes in nucleomorph genomes.}, journal = {Molecular biology and evolution}, volume = {31}, number = {6}, pages = {1437-1443}, doi = {10.1093/molbev/msu092}, pmid = {24603278}, issn = {1537-1719}, mesh = {Cell Nucleus/genetics ; Chlorophyta/classification/cytology/*genetics ; Chromosomes ; Cryptophyta/classification/cytology/*genetics ; Evolution, Molecular ; Genome, Plastid ; Molecular Chaperones/*genetics ; Mutation Rate ; Phylogeny ; Plastids/*genetics ; Sequence Analysis, RNA ; Symbiosis ; Up-Regulation ; }, abstract = {Chlorarachniophytes and cryptophytes possess complex plastids that were acquired by the ingestion of a green and red algal endosymbiont, respectively. The plastids are surrounded by four membranes, and a relict nucleus, called the nucleomorph, remains in the periplastidal compartment, which corresponds to the remnant cytoplasm of the endosymbiont. Nucleomorphs contain a greatly reduced genome that possesses only several hundred genes with high evolutionary rates. We examined the relative transcription levels of the genes of all proteins encoded by the nucleomorph genomes of two chlorarachniophytes and three cryptophytes using an RNA-seq transcriptomic approach. The genes of two heat shock proteins, Hsp70 and Hsp90, were highly expressed under normal conditions. It has been shown that molecular chaperone overexpression allows an accumulation of genetic mutations in bacteria. Our results suggest that overexpression of heat shock proteins in nucleomorph genomes may play a role in buffering the mutational destabilization of proteins, which might allow the high evolutionary rates of nucleomorph-encoded proteins.}, }
@article {pmid24602296, year = {2014}, author = {Miyagishima, SY and Kabeya, Y and Sugita, C and Sugita, M and Fujiwara, T}, title = {DipM is required for peptidoglycan hydrolysis during chloroplast division.}, journal = {BMC plant biology}, volume = {14}, number = {}, pages = {57}, pmid = {24602296}, issn = {1471-2229}, mesh = {Chloroplasts/*metabolism ; Glaucophyta/*metabolism ; Hydrolysis ; Peptidoglycan/*metabolism ; Plant Proteins/*metabolism ; }, abstract = {BACKGROUND: Chloroplasts have evolved from a cyanobacterial endosymbiont and their continuity has been maintained over time by chloroplast division, a process which is performed by the constriction of a ring-like division complex at the division site. The division complex has retained certain components of the cyanobacterial division complex, which function inside the chloroplast. It also contains components developed by the host cell, which function outside of the chloroplast and are believed to generate constrictive force from the cytosolic side, at least in red algae and Viridiplantae. In contrast to the chloroplasts in these lineages, those in glaucophyte algae possess a peptidoglycan layer between the two envelope membranes, as do cyanobacteria.<br><br>RESULTS: In this study, we show that chloroplast division in the glaucophyte C. paradoxa does not involve any known chloroplast division proteins of the host eukaryotic origin, but rather, peptidoglycan spitting and probably the outer envelope division process rely on peptidoglycan hydrolyzing activity at the division site by the DipM protein, as in cyanobacterial cell division. In addition, we found that DipM is required for normal chloroplast division in the moss Physcomitrella patens.<br><br>CONCLUSIONS: These results suggest that the regulation of peptidoglycan splitting was essential for chloroplast division in the early evolution of chloroplasts and this activity is likely still involved in chloroplast division in Viridiplantae.}, }
@article {pmid24600010, year = {2014}, author = {Kliot, A and Cilia, M and Czosnek, H and Ghanim, M}, title = {Implication of the bacterial endosymbiont Rickettsia spp. in interactions of the whitefly Bemisia tabaci with tomato yellow leaf curl virus.}, journal = {Journal of virology}, volume = {88}, number = {10}, pages = {5652-5660}, pmid = {24600010}, issn = {1098-5514}, mesh = {Animals ; Begomovirus/*isolation &amp; purification ; Carrier State/*virology ; Gastrointestinal Tract/microbiology/virology ; Hemiptera/*microbiology/*virology ; Microbial Interactions ; Rickettsia/*isolation &amp; purification/*physiology ; *Symbiosis ; }, abstract = {UNLABELLED: Numerous animal and plant viruses are transmitted by arthropod vectors in a persistent, circulative manner. Tomato yellow leaf curl virus (TYLCV) is transmitted by the sweet potato whitefly Bemisia tabaci. We report here that infection with Rickettsia spp., a facultative endosymbiont of whiteflies, altered TYLCV-B. tabaci interactions. A B. tabaci strain infected with Rickettsia acquired more TYLCV from infected plants, retained the virus longer, and exhibited nearly double the transmission efficiency compared to an uninfected B. tabaci strain with the same genetic background. Temporal and spatial antagonistic relationships were discovered between Rickettsia and TYLCV within the whitefly. In different time course experiments, the levels of virus and Rickettsia within the insect were inversely correlated. Fluorescence in situ hybridization analysis of Rickettsia-infected midguts provided evidence for niche exclusion between Rickettsia and TYLCV. In particular, high levels of the bacterium in the midgut resulted in higher virus concentrations in the filter chamber, a favored site for virus translocation along the transmission pathway, whereas low levels of Rickettsia in the midgut resulted in an even distribution of the virus. Taken together, these results indicate that Rickettsia, by infecting the midgut, increases TYLCV transmission efficacy, adding further insights into the complex association between persistent plant viruses, their insect vectors, and microorganism tenants that reside within these insects.<br><br>IMPORTANCE: Interest in bacterial endosymbionts in arthropods and many aspects of their host biology in agricultural and human health systems has been increasing. A recent and relevant studied example is the influence of Wolbachia on dengue virus transmission by mosquitoes. In parallel with our recently studied whitefly-Rickettsia-TYLCV system, other studies have shown that dengue virus levels in the mosquito vector are inversely correlated with bacterial load. Our work here presents evidence of unifying principles between vectors of plant and animal viruses in a role for endosymbionts in manipulating vector biology and pathogen transmission. Our results demonstrate the influence of an interesting and prominent bacterial endosymbiont in Bemisia tabaci in TYLCV transmission, a worldwide disease infecting tomatoes. Besides its agricultural importance, this system provides interesting insights into Bemisia interaction with these newly discovered endosymbionts.}, }
@article {pmid24596263, year = {2014}, author = {Bansal, R and Mian, MA and Michel, AP}, title = {Microbiome diversity of Aphis glycines with extensive superinfection in native and invasive populations.}, journal = {Environmental microbiology reports}, volume = {6}, number = {1}, pages = {57-69}, doi = {10.1111/1758-2229.12108}, pmid = {24596263}, issn = {1758-2229}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification ; *Biodiversity ; Introduced Species ; Japan ; *Microbiota ; North America ; Phylogeny ; Republic of Korea ; }, abstract = {Associations among insects and microbes can lead to beneficial or parasitic interactions. Using 454 sequencing of 16S RNA genes, we compared microbiome diversity and abundance among field-collected (F) and laboratory-reared (L) populations of the invasive soybean aphid (Aphis glycines), a pest of soybean. Additionally, we screened A. glycines populations from native (Japan, South Korea and China) and invasive regions (North America) to broadly determine the microbiome diversity. Our results suggested that Arsenophonus (relative abundance of 54.6%), Buchnera (38.7%) and Wolbachia (3.7%) were the major bacteria associated with A. glycines. Arsenophonus was the most abundant in F populations but was significantly reduced in L populations; additional bacteria species also had lower relative abundances in L populations. Native and invasive populations were largely similar in bacteria communities and revealed substantial superinfection of Arsenophonus and Wolbachia. The lone exception was a lack of Arsenophonus in A. glycines from Japan. Divergent selection pressures among natural and laboratory populations were inferred as factors driving the differential bacterial communities observed. Our results will allow for improved comparative aphid-symbiont research and broaden our understanding of the interactions among insects, endosymbionts and their environments.}, }
@article {pmid24593671, year = {2014}, author = {Felden, J and Ruff, SE and Ertefai, T and Inagaki, F and Hinrichs, KU and Wenzhöfer, F}, title = {Anaerobic methanotrophic community of a 5346-m-deep vesicomyid clam colony in the Japan Trench.}, journal = {Geobiology}, volume = {12}, number = {3}, pages = {183-199}, pmid = {24593671}, issn = {1472-4669}, mesh = {Anaerobiosis ; Animals ; Archaea/genetics/isolation &amp; purification/*physiology ; Bacteria/genetics/isolation &amp; purification ; *Bacterial Physiological Phenomena ; Biota ; Bivalvia/*microbiology/physiology ; Geologic Sediments/chemistry/microbiology ; Hydrothermal Vents/chemistry/*microbiology ; Lipid Metabolism ; Methane/metabolism ; Molecular Sequence Data ; Pacific Ocean ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sulfates/metabolism ; }, abstract = {Vesicomyidae clams harbor sulfide-oxidizing endosymbionts and are typical members of cold seep communities where active venting of fluids and gases takes place. We investigated the central biogeochemical processes that supported a vesicomyid clam colony as part of a locally restricted seep community in the Japan Trench at 5346 m water depth, one of the deepest seep settings studied to date. An integrated approach of biogeochemical and molecular ecological techniques was used combining in situ and ex situ measurements. In sediment of the clam colony, low sulfate reduction rates (maximum 128 nmol mL(-1) day(-1)) were coupled to the anaerobic oxidation of methane. They were observed over a depth range of 15 cm, caused by active transport of sulfate due to bioturbation of the vesicomyid clams. A distinct separation between the seep and the surrounding seafloor was shown by steep horizontal geochemical gradients and pronounced microbial community shifts. The sediment below the clam colony was dominated by anaerobic methanotrophic archaea (ANME-2c) and sulfate-reducing Desulfobulbaceae (SEEP-SRB-3, SEEP-SRB-4). Aerobic methanotrophic bacteria were not detected in the sediment, and the oxidation of sulfide seemed to be carried out chemolithoautotrophically by Sulfurovum species. Thus, major redox processes were mediated by distinct subgroups of seep-related microorganisms that might have been selected by this specific abyssal seep environment. Fluid flow and microbial activity were low but sufficient to support the clam community over decades and to build up high biomasses. Hence, the clams and their microbial communities adapted successfully to a low-energy regime and may represent widespread chemosynthetic communities in the Japan Trench. In this regard, they contributed to the restricted deep-sea trench biodiversity as well as to the organic carbon availability, also for non-seep organisms, in such oligotrophic benthic environment of the dark deep ocean.}, }
@article {pmid24591518, year = {2014}, author = {Gray, MW}, title = {The pre-endosymbiont hypothesis: a new perspective on the origin and evolution of mitochondria.}, journal = {Cold Spring Harbor perspectives in biology}, volume = {6}, number = {3}, pages = {}, pmid = {24591518}, issn = {1943-0264}, mesh = {Alphaproteobacteria/genetics ; *Biological Evolution ; DNA, Mitochondrial/chemistry ; Genome, Bacterial ; Genome, Mitochondrial ; Mitochondria/*genetics/physiology/ultrastructure ; Phylogeny ; Symbiosis ; }, abstract = {Mitochondrial DNA (mtDNA) is unquestionably the remnant of an α-proteobacterial genome, yet only ~10%-20% of mitochondrial proteins are demonstrably α-proteobacterial in origin (the "α-proteobacterial component," or APC). The evolutionary ancestry of the non-α-proteobacterial component (NPC) is obscure and not adequately accounted for in current models of mitochondrial origin. I propose that in the host cell that accommodated an α-proteobacterial endosymbiont, much of the NPC was already present, in the form of a membrane-bound metabolic organelle (the premitochondrion) that compartmentalized many of the non-energy-generating functions of the contemporary mitochondrion. I suggest that this organelle also possessed a protein import system and various ion and small-molecule transporters. In such a scenario, an α-proteobacterial endosymbiont could have been converted relatively directly and rapidly into an energy-generating organelle that incorporated the extant metabolic functions of the premitochondrion. This model (the "pre-endosymbiont hypothesis") effectively represents a synthesis of previous, contending mitochondrial origin hypotheses, with the bulk of the mitochondrial proteome (much of the NPC) having an endogenous origin and the minority component (the APC) having a xenogenous origin.}, }
@article {pmid24588548, year = {2014}, author = {Pinheiro, P and Bereman, MS and Burd, J and Pals, M and Armstrong, S and Howe, KJ and Thannhauser, TW and MacCoss, MJ and Gray, SM and Cilia, M}, title = {Evidence of the biochemical basis of host virulence in the greenbug aphid, Schizaphis graminum (Homoptera: Aphididae).}, journal = {Journal of proteome research}, volume = {13}, number = {4}, pages = {2094-2108}, doi = {10.1021/pr4012415}, pmid = {24588548}, issn = {1535-3907}, mesh = {Animals ; Aphids/genetics/microbiology/*pathogenicity/*physiology ; Buchnera ; Host-Parasite Interactions ; Insect Proteins/*analysis/classification/genetics/metabolism ; Poaceae/parasitology ; Proteome/*analysis/genetics/metabolism/*physiology ; Symbiosis ; }, abstract = {Biotypes of aphids and many other insect pests are defined based on the phenotypic response of host plants to the insect pest without considering their intrinsic characteristics and genotypes. Plant breeders have spent considerable effort developing aphid-resistant, small-grain varieties to limit insecticide control of the greenbug, Schizaphis graminum. However, new S. graminum biotypes frequently emerge that break resistance. Mechanisms of virulence on the aphid side of the plant-insect interaction are not well understood. S. graminum biotype H is highly virulent on most small grain varieties. This characteristic makes biotype H ideal for comparative proteomics to investigate the basis of biotype virulence in aphids. In this study, we used comparative proteomics to identify protein expression differences associated with virulence. Aphid proteins involved in the tricarboxylic acid cycle, immune system, cell division, and antiapoptosis pathways were found to be up-regulated in biotype H relative to other biotypes. Proteins from the bacterial endosymbiont of aphids were also differentially expressed in biotype H. Guided by the proteome results, we tested whether biotype H had a fitness advantage compared with other S. graminum biotypes and found that biotype H had a higher reproductive fitness as compared with two other biotypes on a range of different wheat germplasms. Finally, we tested whether aphid genetics can be used to further dissect the genetic mechanisms of biotype virulence in aphids. The genetic data showed that sexual reproduction is a source of biotypic variation observed in S. graminum.}, }
@article {pmid24583288, year = {2014}, author = {Ramulu, HG and Groussin, M and Talla, E and Planel, R and Daubin, V and Brochier-Armanet, C}, title = {Ribosomal proteins: toward a next generation standard for prokaryotic systematics?.}, journal = {Molecular phylogenetics and evolution}, volume = {75}, number = {}, pages = {103-117}, doi = {10.1016/j.ympev.2014.02.013}, pmid = {24583288}, issn = {1095-9513}, mesh = {Bayes Theorem ; Biological Evolution ; DNA, Bacterial/genetics ; Epsilonproteobacteria/classification/genetics ; Gene Transfer, Horizontal ; Likelihood Functions ; Models, Genetic ; *Phylogeny ; Proteobacteria/*classification/genetics ; Ribosomal Proteins/*genetics ; Ribosome Subunits, Small, Bacterial/genetics ; Sequence Analysis, DNA ; }, abstract = {The seminal work of Carl Woese and co-workers has contributed to promote the RNA component of the small subunit of the ribosome (SSU rRNA) as a "gold standard" of modern prokaryotic taxonomy and systematics, and an essential tool to explore microbial diversity. Yet, this marker has a limited resolving power, especially at deep phylogenetic depth and can lead to strongly biased trees. The ever-larger number of available complete genomes now calls for a novel standard dataset of robust protein markers that may complement SSU rRNA. In this respect, concatenation of ribosomal proteins (r-proteins) is being growingly used to reconstruct large-scale prokaryotic phylogenies, but their suitability for systematic and/or taxonomic purposes has not been specifically addressed. Using Proteobacteria as a case study, we show that amino acid and nucleic acid r-protein sequences contain a reliable phylogenetic signal at a wide range of taxonomic depths, which has not been totally blurred by mutational saturation or horizontal gene transfer. The use of accurate evolutionary models and reconstruction methods allows overcoming most tree reconstruction artefacts resulting from compositional biases and/or fast evolutionary rates. The inferred phylogenies allow clarifying the relationships among most proteobacterial orders and families, along with the position of several unclassified lineages, suggesting some possible revisions of the current classification. In addition, we investigate the root of the Proteobacteria by considering the time-variation of nucleic acid composition of r-protein sequences and the information carried by horizontal gene transfers, two approaches that do not require the use of an outgroup and limit tree reconstruction artefacts. Altogether, our analyses indicate that r-proteins may represent a promising standard for prokaryotic taxonomy and systematics.}, }
@article {pmid24568875, year = {2014}, author = {Sato, T and Nagasato, C and Hara, Y and Motomura, T}, title = {Cell cycle and nucleomorph division in Pyrenomonas helgolandii (Cryptophyta).}, journal = {Protist}, volume = {165}, number = {2}, pages = {113-122}, doi = {10.1016/j.protis.2014.01.003}, pmid = {24568875}, issn = {1618-0941}, mesh = {*Cell Cycle ; Cell Nucleus/*physiology/ultrastructure ; Cryptophyta/*physiology/ultrastructure ; DNA/biosynthesis ; Darkness ; Light ; Microscopy, Electron ; Microscopy, Fluorescence ; }, abstract = {The cells of cryptophycean and chlorarachniophycean algae contain a nucleomorph, a vestigial nucleus derived from red and green algal endosymbionts respectively. The origin of the nucleomorph is therefore different from that of cellular organelles such as mitochondria and chloroplasts. In this study, we sought to determine whether cell cycle regulation of the nucleomorph in the cryptophycean alga Pyrenomonas helgolandii is functionally similar to that of the cell nucleus. We performed an ultrastructural analysis of nucleomorph division in cells prepared by rapid freezing fixation - freeze substitution and also carried out BrdU labeling experiments to determine the timing of nucleomorph DNA synthesis in relation to that of the cell nucleus. In cells cultured under 16 hours light: 8 hours dark conditions, BrdU labeling experiments showed that DNA synthesis in the nucleomorph occurred during a limited period from 2 hr to 4 hr after the beginning of the dark period. The S phase in the nucleomorph started just after completion of the nuclear S phase. Thus, DNA synthesis in the nucleomorph occurred at a defined period of the cell cycle. By contrast, our BrdU experiments showed that the nucleoids of mitochondria and chloroplasts could perform DNA synthesis throughout the whole cell cycle.}, }
@article {pmid24558462, year = {2014}, author = {Su, Q and Xie, W and Wang, S and Wu, Q and Liu, B and Fang, Y and Xu, B and Zhang, Y}, title = {The endosymbiont Hamiltonella increases the growth rate of its host Bemisia tabaci during periods of nutritional stress.}, journal = {PloS one}, volume = {9}, number = {2}, pages = {e89002}, pmid = {24558462}, issn = {1932-6203}, mesh = {Amino Acids/metabolism ; Analysis of Variance ; Animal Nutritional Physiological Phenomena/*physiology ; Animals ; China ; Enterobacteriaceae/metabolism/*physiology ; Hemiptera/*growth &amp; development/*microbiology ; Nitrogen/metabolism ; Stress, Physiological/*physiology ; *Symbiosis ; }, abstract = {The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) harbors several bacterial symbionts. Among the secondary (facultative) symbionts, Hamiltonella has high prevalence and high infection frequencies, suggesting that it may be important for the biology and ecology of its hosts. Previous reports indicated that Hamiltonella increases whitefly fitness and, based on the complete sequencing of its genome, may have the ability to synthesize cofactors and amino acids that are required by its host but that are not sufficiently synthesized by the host or by the primary endosymbiont, Portiera. Here, we assessed the effects of Hamiltonella infection on the growth of B. tabaci reared on low-, standard-, or high-nitrogen diets. When B. tabaci was reared on a standard-nitrogen diet, no cost or benefit was associated with Hamiltonella infection. But, if we reared whiteflies on low-nitrogen diets, Hamiltonella-infected whiteflies often grew better than uninfected whiteflies. Furthermore, nitrogen levels in field-collected whiteflies indicated that the nutritional conditions in the field were comparable to the low-nitrogen diet in our laboratory experiment. These data suggest that Hamiltonella may play a previously unrecognized role as a nutritional mutualist in B. tabaci.}, }
@article {pmid24555501, year = {2014}, author = {Costopoulos, K and Kovacs, JL and Kamins, A and Gerardo, NM}, title = {Aphid facultative symbionts reduce survival of the predatory lady beetle Hippodamia convergens.}, journal = {BMC ecology}, volume = {14}, number = {}, pages = {5}, pmid = {24555501}, issn = {1472-6785}, mesh = {Animals ; Aphids/*microbiology ; Coleoptera/*growth &amp; development ; Feeding Behavior ; Female ; Larva/growth &amp; development ; Least-Squares Analysis ; Linear Models ; Male ; Population Dynamics ; *Predatory Behavior ; Symbiosis ; }, abstract = {BACKGROUND: Non-essential facultative endosymbionts can provide their hosts with protection from parasites, pathogens, and predators. For example, two facultative bacterial symbionts of the pea aphid (Acyrthosiphon pisum), Serratia symbiotica and Hamiltonella defensa, protect their hosts from parasitism by two species of parasitoid wasp. Previous studies have not explored whether facultative symbionts also play a defensive role against predation in this system. We tested whether feeding on aphids harboring different facultative symbionts affected the fitness of an aphid predator, the lady beetle Hippodamia convergens.<br><br>RESULTS: While these aphid faculative symbionts did not deter lady beetle feeding, they did decrease survival of lady beetle larvae. Lady beetle larvae fed a diet of aphids with facultative symbionts had significantly reduced survival from egg hatching to pupation and therefore had reduced survival to adult emergence. Additionally, lady beetle adults fed aphids with facultative symbionts were significantly heavier than those fed facultative symbiont-free aphids, though development time was not significantly different.<br><br>CONCLUSIONS: Aphids reproduce clonally and are often found in large groups. Thus, aphid symbionts, by reducing the fitness of the aphid predator H. convergens, may indirectly defend their hosts' clonal descendants against predation. These findings highlight the often far-reaching effects that symbionts can have in ecological systems.}, }
@article {pmid24552661, year = {2014}, author = {Zimmermann, J and Lott, C and Weber, M and Ramette, A and Bright, M and Dubilier, N and Petersen, JM}, title = {Dual symbiosis with co-occurring sulfur-oxidizing symbionts in vestimentiferan tubeworms from a Mediterranean hydrothermal vent.}, journal = {Environmental microbiology}, volume = {16}, number = {12}, pages = {3638-3656}, doi = {10.1111/1462-2920.12427}, pmid = {24552661}, issn = {1462-2920}, mesh = {Animals ; Base Sequence ; Carbon Cycle ; Ecosystem ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification/*metabolism ; Genes, rRNA ; Genetic Variation ; *Hydrothermal Vents ; In Situ Hybridization, Fluorescence ; Mediterranean Sea ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; Polychaeta/classification/*microbiology/*physiology ; RNA, Ribosomal, 16S/genetics ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Vestimentiferan Tws colonize hydrothermal vents and cold seeps worldwide. They lack a digestive system and gain nutrition from endosymbiotic sulfur-oxidizing bacteria. It is currently assumed that vestimentiferan Tws harbour only a single endosymbiont type. A few studies found indications for additional symbionts, but conclusive evidence for a multiple symbiosis is still missing. We investigated Tws from Marsili Seamount, a hydrothermal vent in the Mediterranean Sea. Molecular and morphological analyses identified the Tws as Lamellibrachia anaximandri. 16S ribosomal RNA clone libraries revealed two distinct gammaproteobacterial phylotypes that were closely related to sequences from other Lamellibrachia symbionts. Catalysed reporter deposition fluorescence in situ hybridization with specific probes showed that these sequences are from two distinct symbionts. We also found two variants of key genes for sulfur oxidation and carbon fixation, suggesting that both symbiont types are autotrophic sulfur oxidizers. Our results therefore show that vestimentiferans can host multiple co-occurring symbiont types. Statistical analyses of vestimentiferan symbiont diversity revealed that host genus, habitat type, water depth and geographic region together accounted for 27% of genetic diversity, but only water depth had a significant effect on its own. Phylogenetic analyses showed a clear grouping of sequences according to depth, thus confirming the important role water depth played in shaping vestimentiferan symbiont diversity.}, }
@article {pmid24528556, year = {2014}, author = {Duncan, RP and Husnik, F and Van Leuven, JT and Gilbert, DG and Dávalos, LM and McCutcheon, JP and Wilson, ACC}, title = {Dynamic recruitment of amino acid transporters to the insect/symbiont interface.}, journal = {Molecular ecology}, volume = {23}, number = {6}, pages = {1608-1623}, doi = {10.1111/mec.12627}, pmid = {24528556}, issn = {1365-294X}, mesh = {Amino Acid Transport Systems/*genetics ; Animals ; Bacteria ; Evolution, Molecular ; Female ; *Gene Duplication ; Hemiptera/genetics/*microbiology ; Insect Proteins/*genetics ; Multigene Family ; Phylogeny ; *Symbiosis ; Transcriptome ; }, abstract = {Symbiosis is well known to influence bacterial symbiont genome evolution and has recently been shown to shape eukaryotic host genomes. Intriguing patterns of host genome evolution, including remarkable numbers of gene duplications, have been observed in the pea aphid, a sap-feeding insect that relies on a bacterial endosymbiont for amino acid provisioning. Previously, we proposed that gene duplication has been important for the evolution of symbiosis based on aphid-specific gene duplication in amino acid transporters (AATs), with some paralogs highly expressed in the cells housing symbionts (bacteriocytes). Here, we use a comparative approach to test the role of gene duplication in enabling recruitment of AATs to bacteriocytes. Using genomic and transcriptomic data, we annotate AATs from sap-feeding and non sap-feeding insects and find that, like aphids, AAT gene families have undergone independent large-scale gene duplications in three of four additional sap-feeding insects. RNA-seq differential expression data indicate that, like aphids, the sap-feeding citrus mealybug possesses several lineage-specific bacteriocyte-enriched paralogs. Further, differential expression data combined with quantitative PCR support independent evolution of bacteriocyte enrichment in sap-feeding insect AATs. Although these data indicate that gene duplication is not necessary to initiate host/symbiont amino acid exchange, they support a role for gene duplication in enabling AATs to mediate novel host/symbiont interactions broadly in the sap-feeding suborder Sternorrhyncha. In combination with recent studies on other symbiotic systems, gene duplication is emerging as a general pattern in host genome evolution.}, }
@article {pmid24515833, year = {2014}, author = {Mueller, SJ and Lang, D and Hoernstein, SN and Lang, EG and Schuessele, C and Schmidt, A and Fluck, M and Leisibach, D and Niegl, C and Zimmer, AD and Schlosser, A and Reski, R}, title = {Quantitative analysis of the mitochondrial and plastid proteomes of the moss Physcomitrella patens reveals protein macrocompartmentation and microcompartmentation.}, journal = {Plant physiology}, volume = {164}, number = {4}, pages = {2081-2095}, pmid = {24515833}, issn = {1532-2548}, mesh = {Biological Evolution ; Bryopsida/*metabolism ; *Cell Compartmentation ; Cluster Analysis ; Gene Knock-In Techniques ; Metabolic Networks and Pathways ; Mitochondria/metabolism ; Multivariate Analysis ; Plant Proteins/*metabolism ; Plastids/metabolism ; Proteome/*metabolism ; Proteomics/*methods ; Staining and Labeling ; Subcellular Fractions/metabolism ; Symbiosis ; }, abstract = {Extant eukaryotes are highly compartmentalized and have integrated endosymbionts as organelles, namely mitochondria and plastids in plants. During evolution, organellar proteomes are modified by gene gain and loss, by gene subfunctionalization and neofunctionalization, and by changes in protein targeting. To date, proteomics data for plastids and mitochondria are available for only a few plant model species, and evolutionary analyses of high-throughput data are scarce. We combined quantitative proteomics, cross-species comparative analysis of metabolic pathways, and localizations by fluorescent proteins in the model plant Physcomitrella patens in order to assess evolutionary changes in mitochondrial and plastid proteomes. This study implements data-mining methodology to classify and reliably reconstruct subcellular proteomes, to map metabolic pathways, and to study the effects of postendosymbiotic evolution on organellar pathway partitioning. Our results indicate that, although plant morphologies changed substantially during plant evolution, metabolic integration of organelles is largely conserved, with exceptions in amino acid and carbon metabolism. Retargeting or regulatory subfunctionalization are common in the studied nucleus-encoded gene families of organelle-targeted proteins. Moreover, complementing the proteomic analysis, fluorescent protein fusions revealed novel proteins at organelle interfaces such as plastid stromules (stroma-filled tubules) and highlight microcompartments as well as intercellular and intracellular heterogeneity of mitochondria and plastids. Thus, we establish a comprehensive data set for mitochondrial and plastid proteomes in moss, present a novel multilevel approach to organelle biology in plants, and place our findings into an evolutionary context.}, }
@article {pmid24508344, year = {2014}, author = {Ghanim, M}, title = {A review of the mechanisms and components that determine the transmission efficiency of Tomato yellow leaf curl virus (Geminiviridae; Begomovirus) by its whitefly vector.}, journal = {Virus research}, volume = {186}, number = {}, pages = {47-54}, doi = {10.1016/j.virusres.2014.01.022}, pmid = {24508344}, issn = {1872-7492}, mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Begomovirus/*genetics/metabolism/pathogenicity ; Biological Transport ; Chaperonin 60/genetics/metabolism ; Gene Expression ; HSP70 Heat-Shock Proteins/genetics/metabolism ; Hemiptera/microbiology/*virology ; Hemolymph/microbiology/virology ; Host-Parasite Interactions ; Host-Pathogen Interactions ; Insect Vectors/microbiology/*virology ; Lycopersicon esculentum/parasitology/*virology ; Phloem/parasitology/virology ; Plant Diseases/parasitology/*virology ; Salivary Glands/microbiology/virology ; Symbiosis ; Virion/*genetics/metabolism/pathogenicity ; }, abstract = {Begomoviruses are a group of icosahedral single stranded DNA viruses exclusively transmitted by the sweet potato whitefly Bemisia tabaci in a persistent, circulative manner. In this mode of transmission, begomoviruses are acquired by their insect vector as intact virions from the plant phloem, move along the food canal, foregut and esophagus and reach the midgut where they are absorbed into the hemolymph via the filter chamber. The filter chamber is the site where most of the ingested food is filtered, and the first site where the majority of begomoviruses appear to be translocated into the hemolymph via unknown proteins or receptors. Transport from the filter chamber to the hemolymph is aided by a Heat Shock Protein 70. Virus particles not translocated across the filter chamber circulate in the midgut loop but it is not known whether absorption into the hemolymph occurs along this loop. Localization studies have confirmed that begomoviruses are not associated with the hindgut and absorption of virions in this organ is unlikely. In the hemolymph, virions have been shown to interact with a GroEL chaperone produced by the whitefly's endosymbiontic bacteria for ensuring their safe journey to the salivary glands. Virions penetrate the primary salivary glands via unknown proteins or receptors and are transported and secreted outside the whitefly to the plant with salivary secretions. Several recent studies have demonstrated the implications of insect and endosymbiont proteins such as the heat shock protein 70 and the bacterial GroEL protein, in the transmission of begomoviruses by B. tabaci. Additional studies attempting to identify other proteins that aid or interact with begomoviruses along their circulation pathway in the whitefly are reviewed in this paper.}, }
@article {pmid24508015, year = {2014}, author = {Sorek, M and Díaz-Almeyda, EM and Medina, M and Levy, O}, title = {Circadian clocks in symbiotic corals: the duet between Symbiodinium algae and their coral host.}, journal = {Marine genomics}, volume = {14}, number = {}, pages = {47-57}, doi = {10.1016/j.margen.2014.01.003}, pmid = {24508015}, issn = {1876-7478}, mesh = {Alveolata/*physiology ; Animals ; Anthozoa/*physiology ; *Biological Evolution ; Calcification, Physiologic/physiology ; Cell Division/physiology ; Cell Movement/physiology ; Circadian Clocks/*physiology ; Circadian Rhythm/*physiology ; Photosynthesis/physiology ; Reproduction/physiology ; Species Specificity ; Symbiosis/*physiology ; }, abstract = {To date, the association and synchronization between two organismal circadian clocks ticking in parallel as part of a meta-organism (termed a symbiotic association), have rarely been investigated. Reef-building corals exhibit complex rhythmic responses to diurnal, lunar, and annual changes. Understanding circadian, circatidal, and annual regulation in reef-building corals is complicated by the presence of photosynthetic endosymbionts, which have a profound physiochemical influence on the intracellular environment. How corals tune their animal-based clock machinery to respond to external cues while simultaneously responding to internal physiological changes imposed by the symbiont, is not clear. There is insufficient molecular or physiological evidence of the existence of a circadian pacemaker that controls the metabolism, photosynthesis, synchronized mass spawning, and calcification processes in symbiotic corals. In this review, we present current knowledge regarding the animal pacemaker and the symbiotic-algal pacemaker. We examine the evidence from behavioral, physiological, molecular, and evolutionary perspectives. We explain why symbiotic corals are an interesting model with which to study the complexities and evolution of the metazoan circadian clock. We also provide evidence of why the chronobiology of corals is fundamental and extremely important for explaining the biology, physiology, and metabolism of coral reefs. A deeper understanding of these complex issues can help explain coral mass spawning, one of the earth's greatest and most mysterious behavioral phenomena.}, }
@article {pmid24504088, year = {2014}, author = {Aguileta, G and de Vienne, DM and Ross, ON and Hood, ME and Giraud, T and Petit, E and Gabaldón, T}, title = {High variability of mitochondrial gene order among fungi.}, journal = {Genome biology and evolution}, volume = {6}, number = {2}, pages = {451-465}, pmid = {24504088}, issn = {1759-6653}, mesh = {DNA, Mitochondrial/*genetics ; Fungal Proteins/*genetics ; Fungi/classification/*genetics ; *Gene Order ; Gene Rearrangement ; *Genes, Mitochondrial ; *Genetic Variation ; Genome, Mitochondrial ; Introns ; Mitochondria/genetics ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; }, abstract = {From their origin as an early alpha proteobacterial endosymbiont to their current state as cellular organelles, large-scale genomic reorganization has taken place in the mitochondria of all main eukaryotic lineages. So far, most studies have focused on plant and animal mitochondrial (mt) genomes (mtDNA), but fungi provide new opportunities to study highly differentiated mtDNAs. Here, we analyzed 38 complete fungal mt genomes to investigate the evolution of mtDNA gene order among fungi. In particular, we looked for evidence of nonhomologous intrachromosomal recombination and investigated the dynamics of gene rearrangements. We investigated the effect that introns, intronic open reading frames (ORFs), and repeats may have on gene order. Additionally, we asked whether the distribution of transfer RNAs (tRNAs) evolves independently to that of mt protein-coding genes. We found that fungal mt genomes display remarkable variation between and within the major fungal phyla in terms of gene order, genome size, composition of intergenic regions, and presence of repeats, introns, and associated ORFs. Our results support previous evidence for the presence of mt recombination in all fungal phyla, a process conspicuously lacking in most Metazoa. Overall, the patterns of rearrangements may be explained by the combined influences of recombination (i.e., most likely nonhomologous and intrachromosomal), accumulated repeats, especially at intergenic regions, and to a lesser extent, mobile element dynamics.}, }
@article {pmid24495148, year = {2014}, author = {Rouchet, R and Vorburger, C}, title = {Experimental evolution of parasitoid infectivity on symbiont-protected hosts leads to the emergence of genotype specificity.}, journal = {Evolution; international journal of organic evolution}, volume = {68}, number = {6}, pages = {1607-1616}, doi = {10.1111/evo.12377}, pmid = {24495148}, issn = {1558-5646}, mesh = {Adaptation, Physiological ; Animals ; Enterobacteriaceae/*pathogenicity ; *Evolution, Molecular ; Genotype ; Hemiptera/genetics/microbiology/*parasitology ; Host-Parasite Interactions/*genetics ; Selection, Genetic ; *Symbiosis ; Virulence/genetics ; Wasps/*genetics/pathogenicity ; }, abstract = {Host-parasitoid interactions may lead to strong reciprocal selection for traits involved in host defense and parasitoid counterdefense. In aphids, individuals harboring the facultative bacterial endosymbiont, Hamiltonella defensa, exhibit enhanced resistance to parasitoid wasps. We used an experimental evolution approach to investigate the ability of the parasitoid wasp, Lysiphlebus fabarum, to adapt to the presence of H. defensa in its aphid host Aphis fabae. Sexual populations of the parasitoid were exposed for 11 generations to a single clone of A. fabae, either free of H. defensa or harboring artificial infections with three different isolates of H. defensa. Parasitoids adapted rapidly to the presence of H. defensa in their hosts, but this adaptation was in part specific to the symbiont isolate they were evolving against and did not result in an improved infectivity on all symbiont-protected hosts. Comparisons of life-history traits among the evolved lines of parasitoids did not reveal any evidence for costs of adaptation to H. defensa in terms of correlated responses that could constrain such adaptation. These results show that parasitoids readily evolve counter-adaptations to heritable defensive symbionts of their hosts, but that different symbiont strains impose different evolutionary challenges. The symbionts thus mediate the host-parasite interaction by inducing line-by-line genetic specificity.}, }
@article {pmid24482319, year = {2014}, author = {Liu, L and Li, XY and Huang, XL and Qiao, GX}, title = {Evolutionary relationships of Pemphigus and allied genera (Hemiptera: Aphididae: Eriosomatinae) and their primary endosymbiont, Buchnera aphidicola.}, journal = {Insect science}, volume = {21}, number = {3}, pages = {301-312}, doi = {10.1111/1744-7917.12113}, pmid = {24482319}, issn = {1744-7917}, mesh = {Animals ; Aphids/genetics/growth &amp; development/*microbiology/*physiology ; Buchnera/genetics/*physiology ; *Evolution, Molecular ; Genes, Bacterial/genetics ; Genes, Insect/genetics ; Phylogeny ; *Symbiosis ; }, abstract = {Aphids harbor primary endosymbionts, Buchnera aphidicola, in specialized cells within their body cavities. Aphids and Buchnera have strict mutualistic relationships in nutrition exchange. This ancient association has received much attention from researchers who are interested in endosymbiotic evolution. Previous studies have found parallel phylogenetic relationships between non-galling aphids and Buchnera at lower taxonomic levels (genus, species). To understand whether relatively isolated habitats such as galls have effect on the parallel relationships between aphids and Buchnera, the present paper investigated the phylogenetic relationships of gall aphids from Pemphigus and allied genera, which induce pseudo-galls or galls on Populus spp. (poplar) and Buchnera. The molecular phylogenies inferred from three aphid genes (COI, COII and EF-1α) and two Buchnera genes (gnd, 16S rRNA gene) indicated significant congruence between aphids and Buchnera at generic as well as interspecific levels. Interestingly, both aphid and Buchnera phylogenies supported three main clades corresponding to the galling locations of aphids, namely leaf, the joint of leaf blade and petiole, and branch of the host plant. The results suggest phylogenetic conservatism of gall characters, which indicates gall characters are more strongly affected by aphid phylogeny, rather than host plants.}, }
@article {pmid24478421, year = {2014}, author = {Chen, H and Zheng, L and Mao, Q and Liu, Q and Jia, D and Wei, T}, title = {Development of continuous cell culture of brown planthopper to trace the early infection process of oryzaviruses in insect vector cells.}, journal = {Journal of virology}, volume = {88}, number = {8}, pages = {4265-4274}, pmid = {24478421}, issn = {1098-5514}, mesh = {Animals ; Cell Culture Techniques ; Cells, Cultured ; Hemiptera/virology ; Insect Vectors/*virology ; Reoviridae/growth &amp; development/*physiology ; Viral Nonstructural Proteins/genetics/metabolism ; Virus Cultivation/*methods ; *Virus Replication ; }, abstract = {UNLABELLED: Rice ragged stunt virus (RRSV), an oryzavirus in the family Reoviridae, is transmitted by the brown planthopper, Nilaparvata lugens, in a persistent-propagative manner. Here, we established a continuous cell line of brown planthopper to investigate the mechanism underlying the formation of the viroplasm, the putative site for viral replication and assembly, during infection of RRSV in its insect vector cells. Within 24 h of viral infection of cultured cells, the viroplasm had formed and contained the viral nonstructural proteins Pns6 and Pns10, known to be constituents of viroplasm. Core capsid protein P3, core particles, and newly synthesized viral RNAs were accumulated inside the viroplasm, while outer capsid protein P8 and virions were accumulated at the periphery of the viroplasm, confirming that the viroplasm induced by RRSV infection was the site for viral replication and assembly. Pns10 formed viroplasm-like inclusions in the absence of viral infection, suggesting that the viroplasm matrix was largely composed of Pns10. Pns6 was recruited in the viroplasm by direct interaction with Pns10. Core capsid protein P3 was recruited to the viroplasm through specific association with Pns6. Knockdown of Pns6 and Pns10 expression using RNA interference inhibited viroplasm formation, virion assembly, viral protein expression, and viral double-stranded RNA synthesis. Thus, the present study shows that both Pns6 and Pns10 of RRSV play important roles in the early stages of viral life cycle in its insect vector cells, by recruiting or retaining components necessary for viral replication and assembly.<br><br>IMPORTANCE: The brown planthopper, a commonly distributed pest of rice in Asia, is the host of numerous insect endosymbionts, and the major vector of two rice viruses (RRSV and rice grassy stunt virus). For the first time, we successfully established the continuous cell line of brown planthopper. The unique uniformity of brown planthopper cells in the monolayer can support a consistent, synchronous infection by endosymbionts or viral pathogens, improving our understanding of molecular insect-microbe interactions.}, }
@article {pmid24472200, year = {2014}, author = {De Clerck, C and Tsuchida, T and Massart, S and Lepoivre, P and Francis, F and Jijakli, MH}, title = {Combination of genomic and proteomic approaches to characterize the symbiotic population of the banana aphid (Hemiptera: Aphididae).}, journal = {Environmental entomology}, volume = {43}, number = {1}, pages = {29-36}, doi = {10.1603/EN13107}, pmid = {24472200}, issn = {1938-2936}, mesh = {Animals ; Aphids/genetics/*microbiology ; Babuvirus/genetics ; Buchnera/isolation &amp; purification ; DNA, Bacterial/*chemistry/genetics ; Genomics ; Musa ; Symbiosis/genetics ; Wolbachia/isolation &amp; purification ; }, abstract = {Aphids are known to live in symbiosis with specific bacteria called endosymbionts that have positive or negative impacts on their hosts. In this study, six banana aphid (Pentalonia nigronervosa Coquerel) strains from various geographical origins (Gabon, Madagascar, and Burundi) were screened to determine their symbiotic content, using complementary genomic (16S rDNA sequencing and specific polymerase chain reaction) and proteomic (two-dimensional difference gel electrophoresis coupled with protein identification by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry) approaches. Despite the geographical heterogeneity, the combined methods allowed us to identify the same two symbionts in the six aphids strains tested: Buchnera aphidicola and Wolbachia. Although B. aphidicola is found in almost all aphid species, the systematic presence of Wolbachia in banana aphids is particularly interesting, as this bacterium usually has a low prevalence in aphid species. Phylogenetic analyses showed that the Wolbachia sp. strain found in P. nigronervosa was very similar to the strain present in aphids of the genus Cinara, known to have developed a strong and long-term symbiotic association with Wolbachia. The high level of asexual reproduction in P. nigronervosa could be linked to the presence of Wolbachia, but its prevalence also suggests that this symbiotic bacterium could play a more essential role in its aphid host.}, }
@article {pmid24472097, year = {2014}, author = {Dupeyron, M and Leclercq, S and Cerveau, N and Bouchon, D and Gilbert, C}, title = {Horizontal transfer of transposons between and within crustaceans and insects.}, journal = {Mobile DNA}, volume = {5}, number = {1}, pages = {4}, pmid = {24472097}, issn = {1759-8753}, abstract = {BACKGROUND: Horizontal transfer of transposable elements (HTT) is increasingly appreciated as an important source of genome and species evolution in eukaryotes. However, our understanding of HTT dynamics is still poor in eukaryotes because the diversity of species for which whole genome sequences are available is biased and does not reflect the global eukaryote diversity.<br><br>RESULTS: In this study we characterized two Mariner transposable elements (TEs) in the genome of several terrestrial crustacean isopods, a group of animals particularly underrepresented in genome databases. The two elements have a patchy distribution in the arthropod tree and they are highly similar (>93% over the entire length of the element) to insect TEs (Diptera and Hymenoptera), some of which were previously described in Ceratitis rosa (Crmar2) and Drosophila biarmipes (Mariner-5_Dbi). In addition, phylogenetic analyses and comparisons of TE versus orthologous gene distances at various phylogenetic levels revealed that the taxonomic distribution of the two elements is incompatible with vertical inheritance.<br><br>CONCLUSIONS: We conclude that the two Mariner TEs each underwent at least three HTT events. Both elements were transferred once between isopod crustaceans and insects and at least once between isopod crustacean species. Crmar2 was also transferred between tephritid and drosophilid flies and Mariner-5 underwent HT between hymenopterans and dipterans. We demonstrate that these various HTTs took place recently (most likely within the last 3 million years), and propose iridoviruses and/or Wolbachia endosymbionts as potential vectors of these transfers.}, }
@article {pmid24469987, year = {2014}, author = {Falleni, A and Lucchesi, P and Ghezzani, C and Brogger, MI}, title = {Ultrastructural and cytochemical aspects of the germarium and the vitellarium in Syndesmis patagonica (Platyhelminthes, Rhabdocoela, Umagillidae).}, journal = {Journal of morphology}, volume = {275}, number = {6}, pages = {703-719}, doi = {10.1002/jmor.20251}, pmid = {24469987}, issn = {1097-4687}, mesh = {Animals ; Female ; Gonads/cytology ; Oocytes/chemistry/metabolism/ultrastructure ; Oogenesis ; Platyhelminths/classification/*physiology/*ultrastructure ; }, abstract = {The cytoarchitecture of the female gonad of the endosymbiont umagillid Syndesmis patagonica has been investigated using electron microscopy and cytochemical techniques. The female gonad consists of paired germaria and vitellaria located behind the pharynx in the mid-posterior region of the body. Both the germaria and the vitellaria are enveloped by an outer extracellular lamina and an inner sheath of accessory cells which contribute to the extracellular lamina. Oocyte maturation occurs completely during the prophase of the first meiotic division. Oocyte differentiation is characterized by the appearance of chromatoid bodies and the development of endoplasmic reticulum and Golgi complexes. These organelles appear to be involved in the production of round granules, about 2-2.5 μm in diameter, with a homogeneous electron-dense core surrounded by a granular component and a translucent halo delimited by a membrane. These egg granules migrate to the periphery of mature oocytes, are positive to the cytochemical test for polyphenol detection, are unaffected by protease and have been interpreted as eggshell granules. The mature oocytes also contain a small number of yolk granules, lipid droplets, and glycogen particles scattered throughout the ooplasm. The vitellaria are branched organs composed of vitelline follicles with vitellocytes at different stages of maturation. Developing vitellocytes contain well-developed rough endoplasmic reticulum and small Golgi complexes involved in the production of eggshell and yolk globules. Eggshell globules are round, measure 4-5 μm in diameter, and have a mosaic-like patterned content which contains polyphenols. The yolk globules, 2-3 μm in diameter, show a homogeneous protein content of medium electron density, devoid of polyphenols, and completely digested by protease. The mature vitellocytes also contain glycogen as further reserve material. The presence of polyphenolic eggshell granules in the oocytes and of polyphenolic eggshell globules with a mosaic-like pattern in the vitellocytes have been considered apomorphic features of the Rhabdocoela + Prolecithophora.}, }
@article {pmid24468556, year = {2013}, author = {Pandey, N and Singh, A and Rana, VS and Rajagopal, R}, title = {Molecular characterization and analysis of bacterial diversity in Aleurocanthus woglumi (Hemiptera: Aleyrodidae).}, journal = {Environmental entomology}, volume = {42}, number = {6}, pages = {1257-1264}, doi = {10.1603/EN13110}, pmid = {24468556}, issn = {1938-2936}, mesh = {Animals ; Bacteria/chemistry/genetics ; *Biodiversity ; DNA, Bacterial/chemistry ; Electron Transport Complex IV/genetics ; Hemiptera/enzymology/genetics/*microbiology ; *Microbial Consortia ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), commonly referred to as citrus blackfly, is a sap-sucking hemipteran insect. Although polyphagous, citrus is its most preferred host plant. Samples of this insect were collected from Murraya koenigii (L.). The cytochrome c oxidase subunit I gene (mtCO1)-based analysis by sequencing helped in molecular identification of the insect. Phylogenetic analysis of cytB-nd1-LrDNA showed the coevolution of A. woglumi with its primary bacterial symbiont Portiera. Sequencing a 16S rDNA library from insect DNA revealed three bacterial phylotypes, namely, Portiera, Wolbachia, and Erwinia chrysanthemi. Further, we used fluorescence in situ hybridization to visualize the endosymbionts in a whole mount of A. woglumi. Culturable bacteria were obtained on different media and were classified on the basis of 16S rDNA. In total, 30 bacterial phylotypes belonging to 14 different genera, namely, Bacillus, Kocuria, Micrococcus, Staphylococcus, Paenibacillus, Rhodococcus, Rummellibacillus, Arthrobacter, Curtobacterium, Psychrobacillus, Listeria, Brevibacillus, Bhargavae, and Pantoea, were isolated by culturable methods.}, }
@article {pmid24466066, year = {2014}, author = {Fischer, K and Beatty, WL and Weil, GJ and Fischer, PU}, title = {High pressure freezing/freeze substitution fixation improves the ultrastructural assessment of Wolbachia endosymbiont-filarial nematode host interaction.}, journal = {PloS one}, volume = {9}, number = {1}, pages = {e86383}, pmid = {24466066}, issn = {1932-6203}, support = {S10 RR031552/RR/NCRR NIH HHS/United States ; S10RR031552/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/growth &amp; development/*microbiology/*ultrastructure ; Female ; Freeze Substitution/*methods ; *Freezing ; *Host-Pathogen Interactions ; Life Cycle Stages ; Parasites/microbiology/ultrastructure ; Pressure ; Secretory Vesicles/metabolism/ultrastructure ; *Symbiosis ; Wolbachia/*ultrastructure ; }, abstract = {BACKGROUND: Wolbachia α-proteobacteria are essential for growth, reproduction and survival for many filarial nematode parasites of medical and veterinary importance. Endobacteria were discovered in filarial parasites by transmission electron microscopy in the 1970's using chemically fixed specimens. Despite improvements of fixation and electron microscopy techniques during the last decades, methods to study the Wolbachia/filaria interaction on the ultrastructural level remained unchanged and the mechanisms for exchange of materials and for motility of endobacteria are not known.<br><br>METHODOLOGY/PRINCIPAL FINDING: We used high pressure freezing/freeze substitution to improve fixation of Brugia malayi and its endosymbiont, and this led to improved visualization of different morphological forms of Wolbachia. The three concentric, bilayer membranes that surround the endobacterial cytoplasm were well preserved. Vesicles with identical membrane structures were identified close to the endobacteria, and multiple bacteria were sometimes enclosed within a single outer membrane. Immunogold electron microscopy using a monoclonal antibody directed against Wolbachia surface protein-1 labeled the membranes that enclose Wolbachia and Wolbachia-associated vesicles. High densities of Wolbachia were observed in the lateral chords of L4 larvae, immature, and mature adult worms. Extracellular Wolbachia were sometimes present in the pseudocoelomic cavity near the developing female reproductive organs. Wolbachia-associated actin tails were not observed. Wolbachia motility may be explained by their residence within vacuoles, as they may co-opt the host cell's secretory pathway to move within and between cells.<br><br>CONCLUSIONS/SIGNIFICANCE: High pressure freezing/freeze substitution significantly improved the preservation of filarial tissues for electron microscopy to reveal membranes and sub cellular structures that could be crucial for exchange of materials between Wolbachia and its host.}, }
@article {pmid24463012, year = {2014}, author = {Cass, BN and Mozes-Daube, N and Iasur-Kruh, L and Bondy, EC and Kelly, SE and Hunter, MS and Zchori-Fein, E}, title = {Bacterial endosymbionts in field-collected samples of Trialeurodes sp. nr. abutiloneus (Hemiptera: Aleyrodidae).}, journal = {Research in microbiology}, volume = {165}, number = {2}, pages = {77-81}, doi = {10.1016/j.resmic.2014.01.005}, pmid = {24463012}, issn = {1769-7123}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Gossypium/parasitology ; Hemiptera/*microbiology ; Molecular Sequence Data ; Sequence Analysis, DNA ; *Symbiosis ; United States ; }, abstract = {Facultative bacterial endosymbionts are common, influential associates of arthropods, yet their movement among host species has not been well documented. Plant-mediated transmission of Rickettsia has been shown for the whitefly Bemisia tabaci. Bemisia tabaci in USA cotton fields harbors the secondary symbionts Rickettsia and Hamiltonella, and co-occurs with Trialeurodes sp. nr. abutiloneus whiteflies. To determine whether symbionts may be shared, the microbial diversity of these whiteflies on cotton across the USA was analyzed. Trialeurodes sp. nr. abutiloneus bore Portiera, Pseudomonas, Serratia, Arsenophonus and Wolbachia. No Rickettsia or Hamiltonella were detected. These results provide no evidence for horizontal transmission of symbionts between these whitefly genera.}, }
@article {pmid24458589, year = {2014}, author = {Gauthier, N and Clouet, C and Perrakis, A and Kapantaidaki, D and Peterschmitt, M and Tsagkarakou, A}, title = {Genetic structure of Bemisia tabaci Med populations from home-range countries, inferred by nuclear and cytoplasmic markers: impact on the distribution of the insecticide resistance genes.}, journal = {Pest management science}, volume = {70}, number = {10}, pages = {1477-1491}, doi = {10.1002/ps.3733}, pmid = {24458589}, issn = {1526-4998}, mesh = {Animals ; Base Sequence ; Female ; Gene Flow ; Genetics, Population ; Hemiptera/*classification/*genetics/microbiology ; Insecticide Resistance/*genetics ; Insecticides/*pharmacology ; Mediterranean Region ; Microsatellite Repeats ; Organophosphates/*pharmacology ; Phylogeography ; Pyrethrins/*pharmacology ; Symbiosis ; Wolbachia ; }, abstract = {BACKGROUND: Insecticide resistance management in Bemisia tabaci is one of the main issues facing agricultural production today. An extensive survey was undertaken in five Mediterranean countries to examine the resistance status of Med B. tabaci species in its range of geographic origin and the relationship between population genetic structure and the distribution of resistance genes. The investigation combined molecular diagnostic tests, sequence and microsatellite polymorphism studies and monitoring of endosymbionts.<br><br>RESULTS: High frequencies of pyrethroid (L925I and T929V, VGSC gene) and organophosphate (F331W, ace1 gene) resistance mutations were found in France, Spain and Greece, but not in Morocco or Tunisia. Sequence analyses of the COI gene delineated two closely related mitochondrial groups (Q1 and Q2), which were found either sympatrically (Spain) or separately (France). Only Q1 was observed in Greece, Morocco and Tunisia. Bayesian analyses based on microsatellite loci revealed three geographically delineated genetic groups (France, Spain, Morocco/Greece/Tunisia) and high levels of genetic differentiation even between neighbouring samples. Evidence was also found for hybridisation and asymmetrical gene flow between Q1 and Q2.<br><br>CONCLUSIONS: Med B. tabaci is more diverse and structured than reported so far. On a large geographic scale, resistance is affected by population genetic structure, whereas on a local scale, agricultural practices appear to play a major role.}, }
@article {pmid24454548, year = {2014}, author = {Schilthuizen, M and Kellermann, V}, title = {Contemporary climate change and terrestrial invertebrates: evolutionary versus plastic changes.}, journal = {Evolutionary applications}, volume = {7}, number = {1}, pages = {56-67}, pmid = {24454548}, issn = {1752-4571}, abstract = {To forecast the responses of species to future climate change, an understanding of the ability of species to adapt to long-term shifts in temperature is crucial. We present a review on evolutionary adaptation and phenotypic plasticity of temperature-related traits in terrestrial invertebrates. The evidence for adaptive evolution in melanization is good, but we caution that genetic determination needs to be tested in each individual species, and complex genetic correlations may exist. For phenological traits allochronic data sets provide powerful means to track climate-induced changes; however, rarely are responses deconstructed into evolutionary and plastic responses. Laboratory studies suggest climate change responses in these traits will be driven by both. For stress resistance, the evidence for shifts in traits is poor. Studies leaning heavily on Drosophila have demonstrated potential limits to evolutionary responses in desiccation and heat resistance. Quantifying the capacity for these species to respond plastically and extending this work to other taxa will be an important next step. We also note that, although not strictly speaking a species trait, the response of endosymbionts to heat stress requires further study. Finally, while clearly genetic, and possibly adaptive, the anonymous nature of latitudinal shifts in clines of genetic markers in Drosophila prevents further interpretation.}, }
@article {pmid24448981, year = {2014}, author = {Imanian, B and Keeling, PJ}, title = {Horizontal gene transfer and redundancy of tryptophan biosynthetic enzymes in dinotoms.}, journal = {Genome biology and evolution}, volume = {6}, number = {2}, pages = {333-343}, pmid = {24448981}, issn = {1759-6653}, mesh = {Biosynthetic Pathways ; Dinoflagellida/chemistry/classification/*enzymology/*genetics/metabolism ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Molecular Sequence Data ; Phylogeny ; Protozoan Proteins/chemistry/*genetics ; Tryptophan/*biosynthesis ; }, abstract = {A tertiary endosymbiosis between a dinoflagellate host and diatom endosymbiont gave rise to "dinotoms," cells with a unique nuclear and mitochondrial redundancy derived from two evolutionarily distinct eukaryotic lineages. To examine how this unique redundancy might have affected the evolution of metabolic systems, we investigated the transcription of genes involved in biosynthesis of the amino acid tryptophan in three species, Durinskia baltica, Kryptoperidinium foliaceum, and Glenodinium foliaceum. From transcriptome sequence data, we recovered two distinct sets of protein-coding transcripts covering the entire tryptophan biosynthetic pathway. Phylogenetic analyses suggest a diatom origin for one set of the proteins, which we infer to be expressed in the endosymbiont, and that the other arose from multiple horizontal gene transfer events to the dinoflagellate ancestor of the host lineage. This is the first indication that these cells retain redundant sets of transcripts and likely metabolic pathways for the biosynthesis of small molecules and extend their redundancy to their two distinct nuclear genomes.}, }
@article {pmid24446556, year = {2014}, author = {Sumrandee, C and Hirunkanokpun, S and Grubhoffer, L and Baimai, V and Trinachartvanit, W and Ahantarig, A}, title = {Phylogenetic relationships of Francisella-like endosymbionts detected in two species of Amblyomma from snakes in Thailand.}, journal = {Ticks and tick-borne diseases}, volume = {5}, number = {1}, pages = {29-32}, doi = {10.1016/j.ttbdis.2013.08.001}, pmid = {24446556}, issn = {1877-9603}, mesh = {Animals ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Francisella/*classification/genetics/isolation &amp; purification ; Gram-Negative Bacterial Infections/*microbiology ; Ixodidae/*microbiology ; Male ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/veterinary ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Snakes/*microbiology ; Symbiosis ; Thailand/epidemiology ; }, abstract = {Ticks are important vectors of several bacterial pathogens, including Francisella. In this study, a total of 24 adult ticks (Amblyomma varanense and Amblyomma helvolum) collected from 4 species of snake from 3 provinces of Thailand was screened for the presence of Francisella-like endosymbionts (FLEs) by PCR. FLEs were detected in 46% (11/24) of all ticks examined. A phylogenetic analysis of the 16S rDNA sequence indicated that the 11 distinct genotypes of FLEs amplified from A. varanense and A. helvolum (from Khon Kaen and Pichit provinces, respectively) are in the same group, along with other FLEs amplified from the other tick genera. Interestingly, these FLEs are closely related to, but distinct (different clade) from, the FLEs isolated from different tick species previously reported. This work represents the first report of Francisella spp. in snake ticks from Thailand.}, }
@article {pmid24444593, year = {2014}, author = {Bressan, A}, title = {Emergence and evolution of Arsenophonus bacteria as insect-vectored plant pathogens.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {22}, number = {}, pages = {81-90}, doi = {10.1016/j.meegid.2014.01.004}, pmid = {24444593}, issn = {1567-7257}, mesh = {Animals ; *Enterobacteriaceae ; *Hemiptera/microbiology/physiology ; Host-Pathogen Interactions ; Models, Biological ; *Plant Diseases ; Plants/microbiology ; *Symbiosis ; }, abstract = {Arsenophonus bacteria are among the most biologically diverse and widespread endosymbionts of arthropods. Notably, two species, Phlomobacter fragariae and Arsenophonus phytopathogenicus, have been characterized as phloem-restricted plant pathogens that are obligatorily transmitted by and hosted in planthoppers of the family Cixiidae (Hemiptera: Auchenorrhyncha). Here, I review the current understanding on the lifestyle transition, evolution, host interaction, and infection cycles of these emerging plant pathogens.}, }
@article {pmid24431523, year = {2013}, author = {Vashishtha, A and Rathi, B and Kaushik, S and Sharma, KK and Lakhanpaul, S}, title = {"Phloem sap analysis of Schleichera oleosa (Lour) Oken, Butea monosperma (Lam) Taub. and Ziziphus mauritiana (Lam) and hemolymph of Kerria lacca (Kerr) using HPLC and tandem mass spectrometry".}, journal = {Physiology and molecular biology of plants : an international journal of functional plant biology}, volume = {19}, number = {4}, pages = {537-545}, pmid = {24431523}, issn = {0971-5894}, abstract = {Females of lac insects especially of Kerria lacca (Kerr) secret a resin known as lac for their own protection, which has tremendous applications. Lac insect completes its lifecycle on several host taxa where it exclusively feeds on phloem sap but Schleichera oleosa (Lour.) Oken, Butea monosperma (Lam.) and Ziziphus mauritiana (Lam.) are its major hosts. Analysis of phloem sap constituents as well as hemolymph of lac insect is important because it ultimately gets converted into lac by insect intervention. Main phloem sap constituent's viz. sugars and free amino acids and hemolymph of lac insect were analyzed using HPLC and tandem mass spectrometry, respectively. The results were transformed to relative percentage of the total sugars and free amino acids analyzed in each sample for comparison among lac insect hemolymph and the phloem sap of the three different host taxa. Sucrose (58.9 ± 3.6-85.6 ± 0.9) and trehalose (62.3 ± 0.4) were the predominant sugars in phloem sap of three taxa and hemolymph of lac insect, respectively. Glutamic acid (33.1 ± 1.4-39.8 ± 1.4) was found to be main amino acid among the phloem sap of three taxa while tyrosine (61 ± 2.6) was the major amino acid in hemolymph of lac insect. The relative percentage of non-essential amino acids (60.8 %-69.9 %) was found to be more in all the three host taxa while essential amino acids (30.1 %-35.4 %) were present at a lower relative percentage. In contrast to this, the relative percentage of essential amino acids (81.9 %) was observed to be higher as compared to non-essential amino acids (17.7 %) in lac insect hemolymph. These results led to the detection of lac insect's endosymbionts. Moreover, this study revealed a clue regarding the importance of development of a synthetic diet for this insect so that a precise pathway of lac biosynthesis could be investigated for thorough understanding.}, }
@article {pmid24428638, year = {2014}, author = {Morrow, JL and Frommer, M and Shearman, DC and Riegler, M}, title = {Tropical tephritid fruit fly community with high incidence of shared Wolbachia strains as platform for horizontal transmission of endosymbionts.}, journal = {Environmental microbiology}, volume = {16}, number = {12}, pages = {3622-3637}, doi = {10.1111/1462-2920.12382}, pmid = {24428638}, issn = {1462-2920}, mesh = {Animals ; Australia ; Female ; Incidence ; Male ; Molecular Sequence Data ; Multilocus Sequence Typing ; Phylogeny ; Polymerase Chain Reaction ; *Symbiosis ; Tephritidae/genetics/*microbiology/physiology ; Wasps/microbiology ; Wolbachia/*classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Wolbachia are endosymbiotic bacteria that infect 40-65% of arthropod species. They are primarily maternally inherited with occasional horizontal transmission for which limited direct ecological evidence exists. We detected Wolbachia in 8 out of 24 Australian tephritid species. Here, we have used multilocus sequence typing (MLST) to further characterize these Wolbachia strains, plus a novel quantitative polymerase chain reaction method for allele assignment in multiple infections. Based on five MLST loci and the Wolbachia surface protein gene (wsp), five Bactrocera and one Dacus species harboured two identical strains as double infections; furthermore, Bactrocera neohumeralis harboured both of these as single or double infections, and sibling species B. tryoni harboured one. Two Bactrocera species contained Wolbachia pseudogenes, potentially within the fruit fly genomes. A fruit fly parasitoid, Fopius arisanus shared identical alleles with two Wolbachia strains detected in one B. frauenfeldi individual. We report an unprecedented high incidence of four shared Wolbachia strains in eight host species from two trophic levels. This suggests frequent exposure to Wolbachia in this tropical tephritid community that shares host plant and parasitoid species, and also includes species that hybridize. Such insect communities may act as horizontal transmission platforms that contribute to the ubiquity of the otherwise maternally inherited Wolbachia.}, }
@article {pmid24422686, year = {2014}, author = {Goñi, P and Fernández, MT and Rubio, E}, title = {Identifying endosymbiont bacteria associated with free-living amoebae.}, journal = {Environmental microbiology}, volume = {16}, number = {2}, pages = {339-349}, doi = {10.1111/1462-2920.12363}, pmid = {24422686}, issn = {1462-2920}, mesh = {Amoeba/classification/genetics/*microbiology ; Bacteria/*genetics/*growth &amp; development ; Cell Separation ; Flow Cytometry ; Microbiological Techniques ; Microscopy, Electron ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; *Symbiosis ; }, abstract = {The association between free-living amoebae and pathogenic bacteria is an issue that has gained great importance due to the environmental and health consequences that it implies. In this paper, we analyse the techniques to follow an epidemiological study to identify associations between genera, species, genotypes and subgenotypes of amoebae with pathogenic bacteria, analysing their evolution and considering their usefulness. In this sense, we highlight the combination of microscopic and molecular techniques as the most appropriate way to obtain fully reliable results as well as the need to achieve the standardization of these techniques to allow the comparison of both environmental and clinical results.}, }
@article {pmid24408912, year = {2014}, author = {Esser, C and Kuhn, A and Groth, G and Lercher, MJ and Maurino, VG}, title = {Plant and animal glycolate oxidases have a common eukaryotic ancestor and convergently duplicated to evolve long-chain 2-hydroxy acid oxidases.}, journal = {Molecular biology and evolution}, volume = {31}, number = {5}, pages = {1089-1101}, doi = {10.1093/molbev/msu041}, pmid = {24408912}, issn = {1537-1719}, mesh = {Alcohol Oxidoreductases/chemistry/*genetics/*metabolism ; Animals ; Arabidopsis Proteins/chemistry/genetics/metabolism ; *Evolution, Molecular ; Gene Duplication ; Gene Transfer, Horizontal ; Genes, Plant ; Genetic Speciation ; Models, Molecular ; Phylogeny ; Plants/*enzymology/*genetics ; Protein Conformation ; Structural Homology, Protein ; Substrate Specificity ; Symbiosis/genetics ; }, abstract = {Glycolate oxidase (GOX) is a crucial enzyme of plant photorespiration. The encoding gene is thought to have originated from endosymbiotic gene transfer between the eukaryotic host and the cyanobacterial endosymbiont at the base of plantae. However, animals also possess GOX activities. Plant and animal GOX belong to the gene family of (L)-2-hydroxyacid-oxidases ((L)-2-HAOX). We find that all (L)-2-HAOX proteins in animals and archaeplastida go back to one ancestral eukaryotic sequence; the sole exceptions are green algae of the chlorophyta lineage. Chlorophyta replaced the ancestral eukaryotic (L)-2-HAOX with a bacterial ortholog, a lactate oxidase that may have been obtained through the primary endosymbiosis at the base of plantae; independent losses of this gene may explain its absence in other algal lineages (glaucophyta, rhodophyta, and charophyta). We also show that in addition to GOX, plants possess (L)-2-HAOX proteins with different specificities for medium- and long-chain hydroxyacids (lHAOX), likely involved in fatty acid and protein catabolism. Vertebrates possess lHAOX proteins acting on similar substrates as plant lHAOX; however, the existence of GOX and lHAOX subfamilies in both plants and animals is not due to shared ancestry but is the result of convergent evolution in the two most complex eukaryotic lineages. On the basis of targeting sequences and predicted substrate specificities, we conclude that the biological role of plantae (L)-2-HAOX in photorespiration evolved by co-opting an existing peroxisomal protein.}, }
@article {pmid24407854, year = {2014}, author = {Oakeson, KF and Gil, R and Clayton, AL and Dunn, DM and von Niederhausern, AC and Hamil, C and Aoyagi, A and Duval, B and Baca, A and Silva, FJ and Vallier, A and Jackson, DG and Latorre, A and Weiss, RB and Heddi, A and Moya, A and Dale, C}, title = {Genome degeneration and adaptation in a nascent stage of symbiosis.}, journal = {Genome biology and evolution}, volume = {6}, number = {1}, pages = {76-93}, pmid = {24407854}, issn = {1759-6653}, support = {R01 AI095736/AI/NIAID NIH HHS/United States ; T32 GM007464/GM/NIGMS NIH HHS/United States ; 1R01AI095736/AI/NIAID NIH HHS/United States ; }, mesh = {*Adaptation, Physiological ; Animals ; Base Sequence ; Coleoptera/microbiology ; Enterobacteriaceae/*genetics ; *Evolution, Molecular ; *Genome, Bacterial ; Molecular Sequence Data ; Symbiosis/*genetics ; }, abstract = {Symbiotic associations between animals and microbes are ubiquitous in nature, with an estimated 15% of all insect species harboring intracellular bacterial symbionts. Most bacterial symbionts share many genomic features including small genomes, nucleotide composition bias, high coding density, and a paucity of mobile DNA, consistent with long-term host association. In this study, we focus on the early stages of genome degeneration in a recently derived insect-bacterial mutualistic intracellular association. We present the complete genome sequence and annotation of Sitophilus oryzae primary endosymbiont (SOPE). We also present the finished genome sequence and annotation of strain HS, a close free-living relative of SOPE and other insect symbionts of the Sodalis-allied clade, whose gene inventory is expected to closely resemble the putative ancestor of this group. Structural, functional, and evolutionary analyses indicate that SOPE has undergone extensive adaptation toward an insect-associated lifestyle in a very short time period. The genome of SOPE is large in size when compared with many ancient bacterial symbionts; however, almost half of the protein-coding genes in SOPE are pseudogenes. There is also evidence for relaxed selection on the remaining intact protein-coding genes. Comparative analyses of the whole-genome sequence of strain HS and SOPE highlight numerous genomic rearrangements, duplications, and deletions facilitated by a recent expansion of insertions sequence elements, some of which appear to have catalyzed adaptive changes. Functional metabolic predictions suggest that SOPE has lost the ability to synthesize several essential amino acids and vitamins. Analyses of the bacterial cell envelope and genes encoding secretion systems suggest that these structures and elements have become simplified in the transition to a mutualistic association.}, }
@article {pmid24399256, year = {2014}, author = {Xu, Y and Chen, YH and Yu, X}, title = {Cell culture of the rice brown planthopper, Nilaparvata lugens Stål (Hemiptera: Delphacidae).}, journal = {In vitro cellular &amp; developmental biology. Animal}, volume = {50}, number = {5}, pages = {384-388}, pmid = {24399256}, issn = {1543-706X}, mesh = {Animals ; Hemiptera/*cytology/genetics ; In Vitro Techniques/*methods ; Oryza/parasitology ; Pest Control, Biological ; Primary Cell Culture/*methods ; }, abstract = {The rice brown planthopper (BPH), Nilaparvata lugens (Stål), is one of the most destructive insect pests of rice in Asia. Although resistant rice varieties can be effective in managing planthopper populations, BPH has repeatedly been able to overcome resistant rice varieties. It is possible that BPH adaptation to resistant rice varieties may be related to its endosymbionts. We investigated methods for culturing BPH cells in order to study in-depth interactions between rice, BPH, and its endosymbionts. In this study, we tested EX-CELL™ 405, EX-CELL™ 420, Mitsuhashi and Maramorosch's medium, and Kimura's medium, for in vitro culture of BPH cells. Only Kimura's medium was found to be suitable for BPH cell culture, and BPH embryos around blastokinetic stage were the best source for BPH cell culture. Cells from BPH embryonic tissues adhered to the plate substrate, and the migration of cells was observed within 24 h in primary culture. After 3 mo of subculture, various types of BPH cells were successfully maintained in the Kimura's medium.}, }
@article {pmid24398322, year = {2014}, author = {Sloan, DB and Nakabachi, A and Richards, S and Qu, J and Murali, SC and Gibbs, RA and Moran, NA}, title = {Parallel histories of horizontal gene transfer facilitated extreme reduction of endosymbiont genomes in sap-feeding insects.}, journal = {Molecular biology and evolution}, volume = {31}, number = {4}, pages = {857-871}, pmid = {24398322}, issn = {1537-1719}, support = {S10 RR029676/RR/NCRR NIH HHS/United States ; RR19895/RR/NCRR NIH HHS/United States ; F32 GM099334/GM/NIGMS NIH HHS/United States ; U54 HG003273/HG/NHGRI NIH HHS/United States ; S10 RR019895/RR/NCRR NIH HHS/United States ; 1F32GM099334/GM/NIGMS NIH HHS/United States ; RR029676-01/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; *Evolution, Molecular ; Gammaproteobacteria/*genetics ; Gene Expression ; *Gene Transfer, Horizontal ; Genes, Insect ; Genome, Bacterial ; Hemiptera/*genetics ; Metabolic Networks and Pathways/genetics ; Phylogeny ; RNA, Messenger/genetics ; Sequence Analysis, RNA ; Symbiosis/*genetics ; }, abstract = {Bacteria confined to intracellular environments experience extensive genome reduction. In extreme cases, insect endosymbionts have evolved genomes that are so gene-poor that they blur the distinction between bacteria and endosymbiotically derived organelles such as mitochondria and plastids. To understand the host's role in this extreme gene loss, we analyzed gene content and expression in the nuclear genome of the psyllid Pachypsylla venusta, a sap-feeding insect that harbors an ancient endosymbiont (Carsonella) with one of the most reduced bacterial genomes ever identified. Carsonella retains many genes required for synthesis of essential amino acids that are scarce in plant sap, but most of these biosynthetic pathways have been disrupted by gene loss. Host genes that are upregulated in psyllid cells housing Carsonella appear to compensate for endosymbiont gene losses, resulting in highly integrated metabolic pathways that mirror those observed in other sap-feeding insects. The host contribution to these pathways is mediated by a combination of native eukaryotic genes and bacterial genes that were horizontally transferred from multiple donor lineages early in the evolution of psyllids, including one gene that appears to have been directly acquired from Carsonella. By comparing the psyllid genome to a recent analysis of mealybugs, we found that a remarkably similar set of functional pathways have been shaped by independent transfers of bacterial genes to the two hosts. These results show that horizontal gene transfer is an important and recurring mechanism driving coevolution between insects and their bacterial endosymbionts and highlight interesting similarities and contrasts with the evolutionary history of mitochondria and plastids.}, }
@article {pmid24397934, year = {2014}, author = {Brum, FL and Catta-Preta, CM and de Souza, W and Schenkman, S and Elias, MC and Motta, MC}, title = {Structural characterization of the cell division cycle in Strigomonas culicis, an endosymbiont-bearing trypanosomatid.}, journal = {Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada}, volume = {20}, number = {1}, pages = {228-237}, doi = {10.1017/S1431927613013925}, pmid = {24397934}, issn = {1435-8115}, mesh = {Bacteria ; Cell Cycle/physiology ; Cell Division/physiology ; DNA, Protozoan/analysis/chemistry ; Microscopy, Fluorescence ; Organelles/chemistry/microbiology ; Symbiosis/*physiology ; Trypanosomatina/chemistry/cytology/*microbiology/*physiology ; }, abstract = {Strigomonas culicis (previously referred to as Blastocrithidia culicis) is a monoxenic trypanosomatid harboring a symbiotic bacterium, which maintains an obligatory relationship with the host protozoan. Investigations of the cell cycle in symbiont harboring trypanosomatids suggest that the bacterium divides in coordination with other host cell structures, particularly the nucleus. In this study we used light and electron microscopy followed by three-dimensional reconstruction to characterize the symbiont division during the cell cycle of S. culicis. We observed that during this process, the symbiotic bacterium presents different forms and is found at different positions in relationship to the host cell structures. At the G1/S phase of the protozoan cell cycle, the endosymbiont exhibits a constricted form that appears to elongate, resulting in the bacterium division, which occurs before kinetoplast and nucleus segregation. During cytokinesis, the symbionts are positioned close to each nucleus to ensure that each daughter cell will inherit a single copy of the bacterium. These observations indicated that the association of the bacterium with the protozoan nucleus coordinates the cell cycle in both organisms.}, }
@article {pmid24395812, year = {2014}, author = {Wang, Z and Su, XM and Wen, J and Jiang, LY and Qiao, GX}, title = {Widespread infection and diverse infection patterns of Wolbachia in Chinese aphids.}, journal = {Insect science}, volume = {21}, number = {3}, pages = {313-325}, doi = {10.1111/1744-7917.12102}, pmid = {24395812}, issn = {1744-7917}, mesh = {Animals ; Aphids/*microbiology ; Genetic Variation ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia are intracellular symbionts that infect a wide range of arthropods and filarial nematodes. Aphids are engaged in diverse and complex relationships with their endosymbionts. Four supergroups (A, B, M and N) of Wolbachia were previously detected in aphids and supergroups M and N were only found in aphids. In this study, we detected and described Wolbachia infections in natural populations of aphids in China. Three supergroups (A, B and M) were found in the examined aphid species. Supergroup M was preponderant, whereas supergroups A and B were only detected in certain species. Supergroup N was not found in this study. There were four infection patterns of Wolbachia in aphids, namely, infection with supergroup M alone, co-infection with supergroups A and M, co-infection with supergroups B and M, and co-infection with supergroups A, B and M. The pattern of infection only with supergroup M was universal and was found in all evaluated subfamilies. Only two subfamilies, Aphidinae and Lachninae, manifested to present all four infection patterns. Three patterns were observed in Calaphidinae (M, A&amp;M, B&amp;M) and Eriosomatinae (M, B&amp;M, A&amp;B&amp;M). Two patterns were observed in the Anoeciinae (M, A&amp;M) and Greenideinae (M, B&amp;M), and only one pattern (M) was observed in the remaining families and/or subfamilies of Aphidoidea. These results indicated that Wolbachia infections in Chinese aphids are widespread. Phylogenetic analyses suggest that Wolbachia supergroup M spread rapidly and recently among all host species of aphids in China. Reasons for this spread and its mechanisms are discussed along with the possible effects of Wolbachia on their aphid hosts.}, }
@article {pmid24387805, year = {2014}, author = {Versace, E and Nolte, V and Pandey, RV and Tobler, R and Schlötterer, C}, title = {Experimental evolution reveals habitat-specific fitness dynamics among Wolbachia clades in Drosophila melanogaster.}, journal = {Molecular ecology}, volume = {23}, number = {4}, pages = {802-814}, pmid = {24387805}, issn = {1365-294X}, support = {W 1225/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; DNA, Mitochondrial/genetics ; Drosophila melanogaster/genetics/*microbiology ; *Ecosystem ; *Evolution, Molecular ; Female ; *Genetic Fitness ; Phylogeny ; Polymorphism, Single Nucleotide ; Temperature ; Wolbachia/*genetics ; }, abstract = {The diversity and infection dynamics of the endosymbiont Wolbachia can be influenced by many factors, such as transmission rate, cytoplasmic incompatibility, environment, selection and genetic drift. The interplay of these factors in natural populations can result in heterogeneous infection patterns with substantial differences between populations and strains. The causes of these heterogeneities are not yet understood, partly due to the complexity of natural environments. We present experimental evolution as a new approach to study Wolbachia infection dynamics in replicate populations exposed to a controlled environment. A natural Drosophila melanogaster population infected with strains of Wolbachia belonging to different clades evolved in two laboratory environments (hot and cold) for 1.5 years. In both treatments, the rate of Wolbachia infection increased until fixation. In the hot environment, the relative frequency of different Wolbachia clades remained stable over 37 generations. In the cold environment, however, we observed marked changes in the composition of the Wolbachia population: within 15 generations, one Wolbachia clade increased more than 50% in frequency, whereas the other two clades decreased in frequency, resulting in the loss of one clade. The frequency change was highly reproducible not only among replicates, but also when flies that evolved for 42 generations in the hot environment were transferred to the cold environment. These results document how environmental factors can affect the composition of Wolbachia in D. melanogaster. The high reproducibility of the pattern suggests that experimental evolution studies can efficiently determine the functional basis of habitat-specific fitness among Wolbachia strains.}, }
@article {pmid24383453, year = {2013}, author = {Greiman, SE and Tkach, VV and Vaughan, JA}, title = {Transmission rates of the bacterial endosymbiont, Neorickettsia risticii, during the asexual reproduction phase of its digenean host, Plagiorchis elegans, within naturally infected lymnaeid snails.}, journal = {Parasites &amp; vectors}, volume = {6}, number = {}, pages = {303}, pmid = {24383453}, issn = {1756-3305}, support = {R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Host-Pathogen Interactions ; Neorickettsia risticii/*physiology ; Reproduction ; Snails/*parasitology ; Trematoda/*microbiology ; }, abstract = {BACKGROUND: Neorickettsia are obligate intracellular bacterial endosymbionts of digenean parasites present in all lifestages of digeneans. Quantitative information on the transmission of neorickettsial endosymbionts throughout the complex life cycles of digeneans is lacking. This study quantified the transmission of Neorickettsia during the asexual reproductive phase of a digenean parasite, Plagiorchis elegans, developing within naturally parasitized lymnaeid pond snails.<br><br>METHODS: Lymnaea stagnalis snails were collected from 3 ponds in Nelson County, North Dakota and screened for the presence of digenean cercariae. Cercariae were identified to species by PCR and sequencing of the 28S rRNA gene. Neorickettsia infections were initially detected using nested PCR and sequencing of a partial 16S rRNA gene of pooled cercariae shed from each parasitized snail. Fifty to 100 single cercariae or sporocysts were isolated from each of six parasitized snails and tested for the presence of Neorickettsia using nested PCR to estimate the efficiency at which Neorickettsia were transmitted to cercariae during asexual development of the digenean.<br><br>RESULTS: A total of 616&#x2009;L. stagnalis were collected and 240 (39%) shed digenean cercariae. Of these, 18 (8%) were Neorickettsia-positive. Six Neorickettsia infections were selected to determine the transmission efficiency of Neorickettsia from mother to daughter sporocyst and from daughter sporocyst to cercaria. The prevalence of neorickettsiae in cercariae varied from 11 to 91%. The prevalence of neorickettsiae in sporocysts from one snail was 100%.<br><br>CONCLUSION: Prevalence of Neorickettsia infection in cercariae of Plagiorchis elegans was variable and never reached 100%. Reasons for this are speculative, however, the low prevalence of Neorickettsia observed in some of our samples (11 to 52%) differs from the high prevalence of other, related bacterial endosymbionts, e.g. Wolbachia in Wolbachia-dependent filariid nematodes, where the prevalence among progeny is universally 100%. This suggests that, unlike the Wolbachia-filaria relationship, the Neorickettsia-digenean relationship is not obligatory mutualism. Our study represents the first quantitative estimate of the Neorickettsia transmission through the asexual phase of the digenean life cycle.}, }
@article {pmid24382700, year = {2014}, author = {Peccoud, J and Bonhomme, J and Mahéo, F and de la Huerta, M and Cosson, O and Simon, JC}, title = {Inheritance patterns of secondary symbionts during sexual reproduction of pea aphid biotypes.}, journal = {Insect science}, volume = {21}, number = {3}, pages = {291-300}, doi = {10.1111/1744-7917.12083}, pmid = {24382700}, issn = {1744-7917}, mesh = {Animals ; Aphids/*genetics/*physiology ; Female ; Genotyping Techniques ; Hybridization, Genetic ; *Inheritance Patterns ; Male ; Reproduction/*genetics ; Symbiosis/*genetics ; }, abstract = {Herbivorous insects frequently harbor bacterial symbionts that affect their ecology and evolution. Aphids host the obligatory endosymbiont Buchnera, which is required for reproduction, together with facultative symbionts whose frequencies vary across aphid populations. These maternally transmitted secondary symbionts have been particularly studied in the pea aphid, Acyrthosiphon pisum, which harbors at least 8 distinct bacterial species (not counting Buchnera) having environmentally dependent effects on host fitness. In particular, these symbiont species are associated with pea aphid populations feeding on specific plants. Although they are maternally inherited, these bacteria are occasionally transferred across insect lineages. One mechanism of such nonmaternal transfer is paternal transmission to the progeny during sexual reproduction. To date, transmission of secondary symbionts during sexual reproduction of aphids has been investigated in only a handful of aphid lineages and 3 symbiont species. To better characterize this process, we investigated inheritance patterns of 7 symbiont species during sexual reproduction of pea aphids through a crossing experiment involving 49 clones belonging to 9 host-specialized biotypes, and 117 crosses. Symbiont species in the progeny were detected with diagnostic qualitative PCR at the fundatrix stage hatching from eggs and in later parthenogenetic generations. We found no confirmed case of paternal transmission of symbionts to the progeny, and we observed that maternal transmission of a particular symbiont species (Serratia symbiotica) was quite inefficient. We discuss these observations in respect to the ecology of the pea aphid.}, }
@article {pmid27355014, year = {2014}, author = {Sreerag, RS and Jayaprakas, CA and Ragesh, L and Kumar, SN}, title = {Endosymbiotic Bacteria Associated with the Mealy Bug, Rhizoecus amorphophalli (Hemiptera: Pseudococcidae).}, journal = {International scholarly research notices}, volume = {2014}, number = {}, pages = {268491}, pmid = {27355014}, issn = {2356-7872}, abstract = {The mealy bug, Rhizoecus amorphophalli, is a menace to the aroid farmers due to the intensive infestation on stored tubers. Spraying of pesticides was able to control this pest but it always left a chance for fungal growth. Bacterial endosymbionts associated with the insects provide several benefits to their host. Since such endosymbionts play a vital role even in the physiology of their host, revealing the types of bacteria associated with mealy bug will give basic information, which may throw light on the management of this noxious pest. The present study is the first to identify bacterial endosymbionts associated with R. amorphophalli employing phenotypic characterization and 16S rDNA sequencing. Three culturable bacteria, namely, Bacillus subtilis, Staphylococcus gallinarum, and Staphylococcus saprophyticus, were isolated from R. amorphophalli. Moreover, the antibiotic susceptibility tests against the isolated bacteria showed that all the isolates were susceptible to the three antibiotics tested, except cephalexin. Recently, endosymbionts are used as effective biocontrol agents (BCAs) and the present study will stand as a connecting link in identification and effective utilization of these endosymbionts as BCAs for management of R. amorphophalli.}, }
@article {pmid24373187, year = {2014}, author = {Bryson, RW}, title = {Bacterial endosymbiont infections in 'living fossils': a case study of North American vaejovid scorpions.}, journal = {Molecular ecology resources}, volume = {14}, number = {4}, pages = {789-793}, doi = {10.1111/1755-0998.12220}, pmid = {24373187}, issn = {1755-0998}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; DNA Primers/genetics ; Genetic Testing/methods ; Scorpions/*microbiology ; *Symbiosis ; }, abstract = {Bacterial endosymbionts are common among arthropods, and maternally inherited forms can affect the reproductive and behavioural traits of their arthropod hosts. The prevalence of bacterial endosymbionts and their role in scorpion evolution have rarely been investigated. In this study, 61 samples from 40 species of scorpion in the family Vaejovidae were screened for the presence of the bacterial endosymbionts Cardinium, Rickettsia, Spiroplasma and Wolbachia. No samples were infected by these bacteria. However, one primer pair specifically designed to amplify Rickettsia amplified nontarget genes of other taxa. Similar off-target amplification using another endosymbiont-specific primer was also found during preliminary screenings. Results caution against the overreliance on previously published screening primers to detect bacterial endosymbionts in host taxa and suggest that primer specificity may be higher in primers targeting nuclear rather than mitochondrial genes.}, }
@article {pmid24355929, year = {2014}, author = {Ma, WJ and Vavre, F and Beukeboom, LW}, title = {Manipulation of arthropod sex determination by endosymbionts: diversity and molecular mechanisms.}, journal = {Sexual development : genetics, molecular biology, evolution, endocrinology, embryology, and pathology of sex determination and differentiation}, volume = {8}, number = {1-3}, pages = {59-73}, doi = {10.1159/000357024}, pmid = {24355929}, issn = {1661-5433}, mesh = {Animals ; Arthropods/*microbiology/*physiology ; *Biodiversity ; Haploidy ; Parthenogenesis/physiology ; Sex Determination Processes/physiology ; *Symbiosis ; }, abstract = {Arthropods exhibit a large variety of sex determination systems both at the chromosomal and molecular level. Male heterogamety, female heterogamety, and haplodiploidy occur frequently, but partially different genes are involved. Endosymbionts, such as Wolbachia, Cardinium,Rickettsia, and Spiroplasma, can manipulate host reproduction and sex determination. Four major reproductive manipulation types are distinguished: cytoplasmic incompatibility, thelytokous parthenogenesis, male killing, and feminization. In this review, the effects of these manipulation types and how they interfere with arthropod sex determination in terms of host developmental timing, alteration of sex determination, and modification of sexual differentiation pathways are summarized. Transitions between different manipulation types occur frequently which suggests that they are based on similar molecular processes. It is also discussed how mechanisms of reproductive manipulation and host sex determination can be informative on each other, with a special focus on haplodiploidy. Future directions on how the study of endosymbiotic manipulation of host reproduction can be key to further studies of arthropod sex determination are shown.}, }
@article {pmid24349319, year = {2013}, author = {Nakabachi, A and Nikoh, N and Oshima, K and Inoue, H and Ohkuma, M and Hongoh, Y and Miyagishima, SY and Hattori, M and Fukatsu, T}, title = {Horizontal gene acquisition of Liberibacter plant pathogens from a bacteriome-confined endosymbiont of their psyllid vector.}, journal = {PloS one}, volume = {8}, number = {12}, pages = {e82612}, pmid = {24349319}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Amino Acid Transport Systems/chemistry/genetics ; Animals ; Bacterial Proteins/chemistry/genetics ; Gene Order ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Hemiptera/*microbiology ; *Host-Pathogen Interactions ; Insect Vectors/*microbiology ; Molecular Sequence Data ; Phylogeny ; Rhizobiaceae/classification/*genetics ; Sequence Alignment ; }, abstract = {he Asian citrus psyllid Diaphorina citri is a notorious agricultural pest that transmits the phloem-inhabiting alphaproteobacterial 'Candidatus Liberibacter asiaticus' and allied plant pathogens, which cause the devastating citrus disease called Huanglongbing or greening disease. D. citri harbors two distinct bacterial mutualists in the symbiotic organ called bacteriome: the betaproteobacterium 'Candidatus Profftella armatura' in the syncytial cytoplasm at the center of the bacteriome, and the gammaproteobacterium 'Candidatus Carsonella ruddii' in uninucleate bacteriocytes. Here we report that a putative amino acid transporter LysE of Profftella forms a highly supported clade with proteins of L. asiaticus, L. americanus, and L. solanacearum. L. crescens, the most basal Liberibacter lineage currently known, lacked the corresponding gene. The Profftella-Liberibacter subclade of LysE formed a clade with proteins from betaproteobacteria of the order Burkholderiales, to which Profftella belongs. This phylogenetic pattern favors the hypothesis that the Liberibacter lineage acquired the gene from the Profftella lineage via horizontal gene transfer (HGT) after L. crescens diverged from other Liberibacter lineages. K A/K S analyses further supported the hypothesis that the genes encoded in the Liberibacter genomes are functional. These findings highlight the possible evolutionary importance of HGT between plant pathogens and their insect vector's symbionts that are confined in the symbiotic organ and seemingly sequestered from external microbial populations.}, }
@article {pmid24347564, year = {2015}, author = {Goodacre, SL and Fricke, C and Martin, OY}, title = {A screen for bacterial endosymbionts in the model organisms Tribolium castaneum, T. confusum, Callosobruchus maculatus, and related species.}, journal = {Insect science}, volume = {22}, number = {2}, pages = {165-177}, doi = {10.1111/1744-7917.12096}, pmid = {24347564}, issn = {1744-7917}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Coleoptera/*microbiology ; Reproduction ; Rickettsia/genetics/*isolation &amp; purification ; Spiroplasma/genetics/*isolation &amp; purification ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Reproductive parasites such as Wolbachia are extremely widespread amongst the arthropods and can have a large influence over the reproduction and fitness of their hosts. Undetected infections could thus confound the results of a wide range of studies that focus on aspects of host behavior, reproduction, fitness, and degrees of reproductive isolation. This potential problem has already been underlined by work investigating the incidence of Wolbachia infections in stocks of the model system Drosophila melanogaster. Here we survey a range of lab stocks of further commonly used model arthropods, focusing especially on the flour beetles Tribolium castaneum and Tribolium confusum, the cowpea weevil Callosobruchus maculatus and related species (Coleoptera: Tenebrionidae and Bruchidae). These species are widespread stored product pests so knowledge of infections with symbionts further has potential use in informing biocontrol measures. Beetles were assessed for infection with 3 known microbial reproductive parasites: Wolbachia, Rickettsia, Spiroplasma. Infections with some of these microbes were found in some of the lab stocks studied, although overall infections were relatively rare. The consequences of finding infections in these or other species and the type of previous studies likely to be affected most are discussed.}, }
@article {pmid24342964, year = {2014}, author = {Jayabalasingham, B and Voss, C and Ehrenman, K and Romano, JD and Smith, ME and Fidock, DA and Bosch, J and Coppens, I}, title = {Characterization of the ATG8-conjugation system in 2 Plasmodium species with special focus on the liver stage: possible linkage between the apicoplastic and autophagic systems?.}, journal = {Autophagy}, volume = {10}, number = {2}, pages = {269-284}, pmid = {24342964}, issn = {1554-8635}, support = {R01 AI085584/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antigens, Protozoan/immunology ; Apicoplasts/*immunology ; Autophagy/*immunology ; Autophagy-Related Protein 8 Family ; Female ; Hepatocytes/metabolism ; Liver/metabolism/*microbiology ; Mice ; Microtubule-Associated Proteins/immunology ; Parasites/*immunology/metabolism ; Phagosomes/immunology ; Plasmodium berghei/*immunology ; Plasmodium falciparum/*immunology ; Saccharomyces cerevisiae/immunology ; Saccharomyces cerevisiae Proteins/immunology ; }, abstract = {Plasmodium parasites successfully colonize different habitats within mammals and mosquitoes, and adaptation to various environments is accompanied by changes in their organelle composition and size. Previously, we observed that during hepatocyte infection, Plasmodium discards organelles involved in invasion and expands those implicated in biosynthetic pathways. We hypothesized that this process is regulated by autophagy. Plasmodium spp. possess a rudimentary set of known autophagy-related proteins that includes the ortholog of yeast Atg8. In this study, we analyzed the activity of the ATG8-conjugation pathway over the course of the lifecycle of Plasmodium falciparum and during the liver stage of Plasmodium berghei. We engineered a transgenic P. falciparum strain expressing mCherry-PfATG8. These transgenic parasites expressed mCherry-PfATG8 in human hepatocytes and erythrocytes, and in the midgut and salivary glands of Anopheles mosquitoes. In all observed stages, mCherry-PfATG8 was localized to tubular structures. Our EM and colocalization studies done in P. berghei showed the association of PbATG8 on the limiting membranes of the endosymbiont-derived plastid-like organelle known as the apicoplast. Interestingly, during parasite replication in hepatocytes, the association of PbATG8 with the apicoplast increases as this organelle expands in size. PbATG3, PbATG7 and PbATG8 are cotranscribed in all parasitic stages. Molecular analysis of PbATG8 and PbATG3 revealed a novel mechanism of interaction compared with that observed for other orthologs. This is further supported by the inability of Plasmodium ATG8 to functionally complement atg8Δ yeast or localize to autophagosomes in starved mammalian cells. Altogether, these data suggests a unique role for the ATG8-conjugation system in Plasmodium parasites.}, }
@article {pmid24337107, year = {2014}, author = {Caragata, EP and Rancès, E and O'Neill, SL and McGraw, EA}, title = {Competition for amino acids between Wolbachia and the mosquito host, Aedes aegypti.}, journal = {Microbial ecology}, volume = {67}, number = {1}, pages = {205-218}, pmid = {24337107}, issn = {1432-184X}, mesh = {Aedes/*microbiology/*physiology ; Amino Acids/*metabolism ; Animals ; Cholesterol/metabolism ; Female ; Fertility ; Humans ; Ovum/physiology ; Rats ; Rats, Inbred Lew ; Sheep ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {The endosymbiont Wolbachia represents a promising method of dengue control, as it reduces the ability of the primary vector, the mosquito Aedes aegypti, to transmit viruses. When mosquitoes infected with the virulent Wolbachia strain wMelPop are fed non-human blood, there is a drastic reduction in mosquito fecundity and egg viability. Wolbachia has a reduced genome and is clearly dependent on its host for a wide range of nutritional needs. The fitness defects seen in wMelPop-infected A. aegypti could be explained by competition between the mosquito and the symbiont for essential blood meal nutrients, the profiles of which are suboptimal in non-human blood. Here, we examine cholesterol and amino acids as candidate molecules for competition, as they have critical roles in egg structural development and are known to vary between blood sources. We found that Wolbachia infection reduces total cholesterol levels in mosquitoes by 15-25%. We then showed that cholesterol supplementation of a rat blood meal did not improve fecundity or egg viability deficits. Conversely, amino acid supplementation of sucrose before and after a sheep blood meal led to statistically significant increases in fecundity of approximately 15-20 eggs per female and egg viability of 30-40%. This mosquito system provides the first empirical evidence of competition between Wolbachia and a host over amino acids and may suggest a general feature of Wolbachia-insect associations. These competitive processes could affect many aspects of host physiology and potentially mosquito fitness, a key concern for Wolbachia-based mosquito biocontrol.}, }
@article {pmid24336878, year = {2014}, author = {Tanifuji, G and Onodera, NT and Moore, CE and Archibald, JM}, title = {Reduced nuclear genomes maintain high gene transcription levels.}, journal = {Molecular biology and evolution}, volume = {31}, number = {3}, pages = {625-635}, doi = {10.1093/molbev/mst254}, pmid = {24336878}, issn = {1537-1719}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Cell Nucleus/*genetics ; Cryptophyta/*genetics ; Eukaryota/*genetics ; *Gene Expression Regulation ; Genome Size/*genetics ; Symbiosis/genetics ; *Transcription, Genetic ; }, abstract = {Reductive genome evolution is seen in organisms living in close association with each other, such as in endosymbiosis, symbiosis, and parasitism. The reduced genomes of endosymbionts and parasites often exhibit similar features such as high gene densities and A+T compositional bias. Little is known about how the regulation of gene expression has been affected in organisms with highly compacted genomes. We studied gene transcription patterns in "nucleomorph" genomes, which are relic nuclear genomes of algal endosymbionts found in cryptophytes and chlorarachniophytes. We examined nuclear and nucleomorph gene transcription patterns using RNA-Seq transcriptome and genome mapping analyses in representatives of both lineages. In all four examined genomes, the most highly transcribed nucleomorph gene category was found to be plastid-associated genes. Remarkably, only 0.49-3.37% of the nucleomorph genomes of these organisms did not have any mRNA counterpart in our RNA-Seq data sets, and nucleomorph genes show equal or higher levels of transcription than their counterparts in the nuclear genomes. We hypothesize that elevated levels of nucleomorph gene transcription may serve to counteract the degradation or modification of protein function due to the loss of interacting proteins in the nucleomorph and nucleomorph-associated subcellular compartments.}, }
@article {pmid24336283, year = {2013}, author = {Williams, TA and Foster, PG and Cox, CJ and Embley, TM}, title = {An archaeal origin of eukaryotes supports only two primary domains of life.}, journal = {Nature}, volume = {504}, number = {7479}, pages = {231-236}, pmid = {24336283}, issn = {1476-4687}, support = {BB/C006143/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/C508777/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; /WT_/Wellcome Trust/United Kingdom ; }, mesh = {Archaea/*classification/cytology/genetics ; Bacteria/classification/genetics ; Cell Membrane/metabolism ; Eukaryota/*classification/cytology/genetics ; Mitochondria/genetics ; *Models, Biological ; *Phylogeny ; RNA, Ribosomal/genetics ; Symbiosis ; }, abstract = {The discovery of the Archaea and the proposal of the three-domains 'universal' tree, based on ribosomal RNA and core genes mainly involved in protein translation, catalysed new ideas for cellular evolution and eukaryotic origins. However, accumulating evidence suggests that the three-domains tree may be incorrect: evolutionary trees made using newer methods place eukaryotic core genes within the Archaea, supporting hypotheses in which an archaeon participated in eukaryotic origins by founding the host lineage for the mitochondrial endosymbiont. These results provide support for only two primary domains of life--Archaea and Bacteria--because eukaryotes arose through partnership between them.}, }
@article {pmid24333018, year = {2014}, author = {Dunin-Horkawicz, S and Kopec, KO and Lupas, AN}, title = {Prokaryotic ancestry of eukaryotic protein networks mediating innate immunity and apoptosis.}, journal = {Journal of molecular biology}, volume = {426}, number = {7}, pages = {1568-1582}, doi = {10.1016/j.jmb.2013.11.030}, pmid = {24333018}, issn = {1089-8638}, mesh = {Amino Acid Sequence ; Apoptosis/genetics/*physiology ; Computational Biology ; Eukaryotic Cells/cytology/metabolism ; Immunity, Innate/genetics/*physiology ; Molecular Sequence Data ; Prokaryotic Cells/cytology/metabolism ; Proteins/*chemistry/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {Protein domains characteristic of eukaryotic innate immunity and apoptosis have many prokaryotic counterparts of unknown function. By reconstructing interactomes computationally, we found that bacterial proteins containing these domains are part of a network that also includes other domains not hitherto associated with immunity. This network is connected to the network of prokaryotic signal transduction proteins, such as histidine kinases and chemoreceptors. The network varies considerably in domain composition and degree of paralogy, even between strains of the same species, and its repetitive domains are often amplified recently, with individual repeats sharing up to 100% sequence identity. Both phenomena are evidence of considerable evolutionary pressure and thus compatible with a role in the "arms race" between host and pathogen. In order to investigate the relationship of this network to its eukaryotic counterparts, we performed a cluster analysis of organisms based on a census of its constituent domains across all fully sequenced genomes. We obtained a large central cluster of mainly unicellular organisms, from which multicellular organisms radiate out in two main directions. One is taken by multicellular bacteria, primarily cyanobacteria and actinomycetes, and plants form an extension of this direction, connected via the basal, unicellular cyanobacteria. The second main direction is taken by animals and fungi, which form separate branches with a common root in the α-proteobacteria of the central cluster. This analysis supports the notion that the innate immunity networks of eukaryotes originated from their endosymbionts and that increases in the complexity of these networks accompanied the emergence of multicellularity.}, }
@article {pmid24330462, year = {2013}, author = {Melničáková, J and Derdáková, M and Barák, I}, title = {A system to simultaneously detect tick-borne pathogens based on the variability of the 16S ribosomal genes.}, journal = {Parasites &amp; vectors}, volume = {6}, number = {}, pages = {269}, pmid = {24330462}, issn = {1756-3305}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Bacterial Proteins/genetics/*metabolism ; Gene Expression Regulation, Bacterial/physiology ; Genome, Bacterial ; Oligonucleotide Array Sequence Analysis/*methods ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/*genetics ; Sensitivity and Specificity ; Tick-Borne Diseases/*microbiology ; }, abstract = {BACKGROUND: DNA microarrays can be used to quickly and sensitively identify several different pathogens in one step. Our previously developed DNA microarray, based on the detection of variable regions in the 16S rDNA gene (rrs), which are specific for each selected bacterial genus, allowed the concurrent detection of Borrelia spp., Anaplasma spp., Francisella spp., Rickettsia spp. and Coxiella spp.<br><br>METHODS: In this study, we developed a comprehensive detection system consisting of a second generation DNA microarray and quantitative PCRs. New oligonucleotide capture probes specific for Borrelia burgdorferi s.l. genospecies and Candidatus Neoehrlichia mikurensis were included. This new DNA microarray system required substantial changes in solution composition, hybridization conditions and post-hybridization washes.<br><br>RESULTS: This second generation chip displayed high specificity and sensitivity. The specificity of the capture probes was tested by hybridizing the DNA microarrays with Cy5-labeled, PCR-generated amplicons encoding the rrs genes of both target and non-target bacteria. The detection limit was determined to be 10(3) genome copies, which corresponds to 1-2 pg of DNA. A given sample was evaluated as positive if its mean fluorescence was at least 10% of the mean fluorescence of a positive control. Those samples with fluorescence close to the threshold were further analyzed using quantitative PCRs, developed to identify Francisella spp., Rickettsia spp. and Coxiella spp. Like the DNA microarray, the qPCRs were based on the genus specific variable regions of the rrs gene. No unspecific cross-reactions were detected. The detection limit for Francisella spp. was determined to be only 1 genome copy, for Coxiella spp. 10 copies, and for Rickettsia spp., 100 copies.<br><br>CONCLUSIONS: Our detection system offers a rapid method for the comprehensive identification of tick-borne bacteria, which is applicable to clinical samples. It can also be used to identify both pathogenic and endosymbiontic bacteria in ticks for eco-epidemiological studies, tick laboratory colony testing, and many other applications.}, }
@article {pmid24329998, year = {2014}, author = {Hughes, GL and Rasgon, JL}, title = {Transinfection: a method to investigate Wolbachia-host interactions and control arthropod-borne disease.}, journal = {Insect molecular biology}, volume = {23}, number = {2}, pages = {141-151}, pmid = {24329998}, issn = {1365-2583}, support = {R21 AI070178/AI/NIAID NIH HHS/United States ; R21 AI088311/AI/NIAID NIH HHS/United States ; R21AI088311/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Host-Pathogen Interactions ; Insecta/*microbiology ; Isopoda/*microbiology ; Pest Control, Biological/*methods ; Species Specificity ; Wolbachia/*physiology ; }, abstract = {The bacterial endosymbiont Wolbachia manipulates arthropod host biology in numerous ways, including sex ratio distortion and differential offspring survival. These bacteria infect a vast array of arthropods, some of which pose serious agricultural and human health threats. Wolbachia-mediated phenotypes such as cytoplasmic incompatibility and/or pathogen interference can be used for vector and disease control; however, many medically important vectors and important agricultural species are uninfected or are infected with strains of Wolbachia that do not elicit phenotypes desirable for disease or pest control. The ability to transfer strains of Wolbachia into new hosts (transinfection) can create novel Wolbachia-host associations. Transinfection has two primary benefits. First, Wolbachia-host interactions can be examined to tease apart the influence of the host and bacteria on phenotypes. Second, desirable phenotypes induced by Wolbachia in a particular insect can be transferred to another recipient host. This can allow the manipulation of insect populations that transmit pathogens or detrimentally affect agriculture. As such, transinfection is a valuable tool to explore Wolbachia biology and control arthropod-borne disease. The present review summarizes what is currently known about Wolbachia transinfection methods and applications. We also provide a comprehensive list of published successful and unsuccessful Wolbachia transinfection attempts.}, }
@article {pmid24329755, year = {2014}, author = {Gandon, S and Vale, PF}, title = {The evolution of resistance against good and bad infections.}, journal = {Journal of evolutionary biology}, volume = {27}, number = {2}, pages = {303-312}, doi = {10.1111/jeb.12291}, pmid = {24329755}, issn = {1420-9101}, mesh = {Bacteria/drug effects/*genetics ; Bacteriophages/genetics ; Biological Evolution ; Drug Resistance, Bacterial/genetics ; Evolution, Molecular ; Plasmids ; }, abstract = {Opportunities for genetic exchange are abundant between bacteria and foreign genetic elements (FGEs) such as conjugative plasmids, transposable elements and bacteriophages. The genetic novelty that may arise from these forms of genetic exchange is potentially beneficial to bacterial hosts, but there are also potential costs, which may be considerable in the case of phage infection. Some bacterial resistance mechanisms target both beneficial and deleterious forms of genetic exchange. Using a general epidemiological model, we explored under which conditions such resistance mechanisms may evolve. We considered a population of hosts that may be infected by FGEs that either confer a benefit or are deleterious to host fitness, and we analysed the epidemiological and evolutionary outcomes of resistance evolving under different cost/benefit scenarios. We show that the degree of co-infection between these two types of infection is particularly important in determining the evolutionarily stable level of host resistance. We explore these results using the example of CRISPR-Cas, a form of bacterial immunity that targets a variety of FGEs, and we show the potential role of bacteriophage infection in selecting for resistance mechanisms that in turn limit the acquisition of plasmid-borne antibiotic resistance. Finally, beyond microbes, we discuss how endosymbiotic associations may have shaped the evolution of host immune responses to pathogens.}, }
@article {pmid24326119, year = {2014}, author = {Duffy, MF and Selvarajah, SA and Josling, GA and Petter, M}, title = {Epigenetic regulation of the Plasmodium falciparum genome.}, journal = {Briefings in functional genomics}, volume = {13}, number = {3}, pages = {203-216}, doi = {10.1093/bfgp/elt047}, pmid = {24326119}, issn = {2041-2657}, mesh = {Amino Acid Sequence ; Animals ; *Epigenesis, Genetic ; Evolution, Molecular ; Genome/*genetics ; Histones/chemistry/metabolism ; Humans ; Molecular Sequence Data ; Plasmodium falciparum/*genetics/pathogenicity ; RNA, Untranslated/genetics ; }, abstract = {Recent research has highlighted some unique aspects of chromatin biology in the malaria parasite Plasmodium falciparum. During its erythrocytic lifecycle P. falciparum maintains its genome primarily as unstructured euchromatin. Indeed there is no clear role for chromatin-mediated silencing of the majority of the developmentally expressed genes in P. falciparum. However discontinuous stretches of heterochromatin are critical for variegated expression of contingency genes that mediate key pathogenic processes in malaria. These range from invasion of erythrocytes and antigenic variation to solute transport and growth adaptation in response to environmental changes. Despite lack of structure within euchromatin the nucleus maintains functional compartments that regulate expression of many genes at the nuclear periphery, particularly genes with clonally variant expression. The typical components of the chromatin regulatory machinery are present in P. falciparum; however, some of these appear to have evolved novel species-specific functions, e.g. the dynamic regulation of histone variants at virulence gene promoters. The parasite also appears to have repeatedly acquired chromatin regulatory proteins through lateral transfer from endosymbionts and from the host. P. falciparum chromatin regulators have been successfully targeted with multiple drugs in laboratory studies; hopefully their functional divergence from human counterparts will allow the development of parasite-specific inhibitors.}, }
@article {pmid24324610, year = {2013}, author = {Vršanský, P and van de Kamp, T and Azar, D and Prokin, A and Vidlička, L and Vagovič, P}, title = {Cockroaches probably cleaned up after dinosaurs.}, journal = {PloS one}, volume = {8}, number = {12}, pages = {e80560}, pmid = {24324610}, issn = {1932-6203}, mesh = {Animals ; Cockroaches/*physiology ; Dinosaurs/*physiology ; Feces/chemistry ; *Food Chain ; *Fossils ; Gastrointestinal Tract/anatomy &amp; histology/*physiology ; Herbivory ; Isoptera/physiology ; Lebanon ; Lignin/metabolism ; Symbiosis ; Synchrotrons ; Time Factors ; X-Ray Microtomography ; }, abstract = {Dinosaurs undoubtedly produced huge quantities of excrements. But who cleaned up after them? Dung beetles and flies with rapid development were rare during most of the Mesozoic. Candidates for these duties are extinct cockroaches (Blattulidae), whose temporal range is associated with herbivorous dinosaurs. An opportunity to test this hypothesis arises from coprolites to some extent extruded from an immature cockroach preserved in the amber of Lebanon, studied using synchrotron X-ray microtomography. 1.06% of their volume is filled by particles of wood with smooth edges, in which size distribution directly supports their external pre-digestion. Because fungal pre-processing can be excluded based on the presence of large particles (combined with small total amount of wood) and absence of damages on wood, the likely source of wood are herbivore feces. Smaller particles were broken down biochemically in the cockroach hind gut, which indicates that the recent lignin-decomposing termite and cockroach endosymbionts might have been transferred to the cockroach gut upon feeding on dinosaur feces.}, }
@article {pmid24315960, year = {2014}, author = {Yukuhiro, F and Miyoshi, T and Noda, H}, title = {Actin-mediated transovarial transmission of a yeastlike symbiont in the brown planthopper.}, journal = {Journal of insect physiology}, volume = {60}, number = {}, pages = {111-117}, doi = {10.1016/j.jinsphys.2013.11.010}, pmid = {24315960}, issn = {1879-1611}, mesh = {Actin Cytoskeleton/*physiology ; Actins/*physiology ; Animals ; Ascomycota/*physiology ; Fat Body/microbiology ; Female ; Hemiptera/*microbiology ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Ovary/microbiology ; Symbiosis ; }, abstract = {The brown planthopper Nilaparvata lugens (Hemiptera, Delphacidae) harbors an obligate endosymbiont called the yeastlike symbiont (YLS) in their abdominal fat body. YLS, a filamentous ascomycete belonging to the family Clavicipitaceae, does not spend any part of its life cycle outside the planthopper's body. The YLS is transferred to the next generation via transovarial transmission; it enters the epithelial plug at the posterior end of the host female's ovariole and is transferred to her offspring. In the present study, microscopic examination revealed that actin filaments play an important role in the transmission of YLS. An irregular cell protrusion on the surface of the epithelial plug facilitated the uptake of the YLS, which was then incorporated into the epithelial plug cell. Actin assembly apparently produces the protrusion and actin appears to participate in almost every stage of the process, from the entry of the YLS into the epithelial plug to its delivery to the oocyte. The epithelial plug employs a recognition system for YLS, which drastically changes the cell surface structure to enable the YLS to enter the ovariole.}, }
@article {pmid24312412, year = {2013}, author = {Ellegaard, KM and Klasson, L and Andersson, SG}, title = {Testing the reproducibility of multiple displacement amplification on genomes of clonal endosymbiont populations.}, journal = {PloS one}, volume = {8}, number = {11}, pages = {e82319}, pmid = {24312412}, issn = {1932-6203}, mesh = {Bartonella/genetics ; DNA, Bacterial/genetics ; *Genome, Bacterial ; Reproducibility of Results ; *Symbiosis ; }, abstract = {The multiple displacement amplification method has revolutionized genomic studies of uncultured bacteria, where the extraction of pure DNA in sufficient quantity for next-generation sequencing is challenging. However, the method is problematic in that it amplifies the target DNA unevenly, induces the formation of chimeric reads and also amplifies contaminating DNA. Here, we have tested the reproducibility of the multiple displacement amplification method using serial dilutions of extracted genomic DNA and intact cells from the cultured endosymbiont Bartonella australis. The amplified DNA was sequenced with the Illumina sequencing technology, and the results were compared to sequence data obtained from unamplified DNA in this study as well as from a previously published genome project. We show that artifacts such as the extent of the amplification bias, the percentage of chimeric reads and the relative fraction of contaminating DNA increase dramatically for the smallest amounts of template DNA. The pattern of read coverage was reproducibly obtained for samples with higher amounts of template DNA, suggesting that the bias is non-random and genome-specific. A re-analysis of previously published sequence data obtained after amplification from clonal endosymbiont populations confirmed these predictions. We conclude that many of the artifacts associated with the use of the multiple displacement amplification method can be alleviated or much reduced by using multiple cells as the template for the amplification. These findings should be particularly useful for researchers studying the genomes of endosymbionts and other uncultured bacteria, for which a small clonal population of cells can be isolated.}, }
@article {pmid24302699, year = {2014}, author = {Lagos, DM and Voegtlin, DJ and Coeur d'acier, A and Giordano, R}, title = {Aphis (Hemiptera: Aphididae) species groups found in the Midwestern United States and their contribution to the phylogenetic knowledge of the genus.}, journal = {Insect science}, volume = {21}, number = {3}, pages = {374-391}, doi = {10.1111/1744-7917.12089}, pmid = {24302699}, issn = {1744-7917}, mesh = {Animals ; Aphids/genetics/microbiology/*physiology ; Buchnera/genetics/physiology ; Cell Nucleus/genetics ; DNA, Mitochondrial/genetics ; *Evolution, Molecular ; Female ; Genes, Insect/genetics ; Midwestern United States ; *Phylogeny ; Symbiosis ; }, abstract = {A phylogeny of the genus Aphis Linnaeus, 1 758 was built primarily from specimens collected in the Midwest of the United States. A data matrix was constructed with 68 species and 41 morphological characters with respective character states of alate and apterous viviparous females. Dendrogram topologies of analyses performed using UPGMA (Unweighted Pair Group Method with Arithmetic Mean), Maximum Parsimony and Bayesian analysis of Cytochrome Oxidase I, Elongation Factor 1-α and primary endosymbiont Buchnera aphidicola 16S sequences were not congruent. Bayesian analysis strongly supported most terminal nodes of the phylogenetic trees. The phylogeny was strongly supported by EF1-α, and analysis of COI and EF1-α molecular data combined with morphological characters. It was not supported by single analysis of COI or Buchnera aphidicola 16S. Results from the Bayesian phylogeny show 4 main species groups: asclepiadis, fabae, gossypii, and middletonii. Results place Aphis and species of the genera Protaphis Börner, 1952, Toxoptera Koch, and Xerobion Nevsky, 1928 in a monophyletic clade. Morphological characters support this monophyly as well. The phylogeny shows that the monophyletic clade of the North American middletonii species group belong to the genus Protaphis: P. debilicornis (Gillette &amp; Palmer, 1929), comb. nov., P. echinaceae (Lagos and Voegtlin, 2009), comb. nov., and P. middletonii (Thomas, 1879). The genus Toxoptera should be considered a subgenus of Aphis (stat. nov.). The analysis also indicates that the current genus Iowana Frison, 1954 should be considered a subgenus of Aphis (stat. nov.).}, }
@article {pmid24293321, year = {2015}, author = {Wang, XM and Yang, B and Wang, HW and Yang, T and Ren, CG and Zheng, HL and Dai, CC}, title = {Consequences of antagonistic interactions between endophytic fungus and bacterium on plant growth and defense responses in Atractylodes lancea.}, journal = {Journal of basic microbiology}, volume = {55}, number = {5}, pages = {659-670}, doi = {10.1002/jobm.201300601}, pmid = {24293321}, issn = {1521-4028}, mesh = {Acinetobacter/growth &amp; development/*physiology ; Acremonium/*physiology ; Atractylodes/immunology/*microbiology/*physiology ; Bacterial Adhesion ; Colony Count, Microbial ; Endophytes/growth &amp; development/*physiology ; Microscopy, Electron, Scanning ; Photosynthesis ; Plant Development ; Real-Time Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {Many studies have examined pair-wise interactions between plants and endophytes, while overlooking the interplays among multiple endosymbionts and their combined impacts on hosts. In this study, Atractylodes lancea plantlets were inoculated with endophytic fungus Acremonium strictum AL16, or endophytic bacterium Acinetobacter sp., or both, to investigate the impacts of the three-way symbiosis on the host. Our results showed that defense-related responses of the co-inoculated plantlets were delayed and weakened relative to plantlets with single inoculants, but no detrimental effects on phyto-physiology (growth, photosynthesis) were observed after combined inoculations. Quantitative PCR analysis verified a decrease in AL16 colonization density within plants after co-inoculation with the endobacteria. An in vitro assay was then performed to elucidate the suppressed plant defense responses and reduced fungal colonization by dual inoculation. The data showed that the presence of Acinetobacter sp. reduced AL16 colony diameter and spore germination rate without negatively affecting fungal morphology. Additionally, direct hyphal attachment of the bacterium to AL16 in vitro was visualized by scanning electronic microscopy. Therefore, we propose that a balanced and compatible symbiosis might require constraints conferred by the antagonistic endophyte Acinetobacter sp. on the fungus AL16 in the tripartite endophytic bacterium-fungus-plant system.}, }
@article {pmid24291672, year = {2014}, author = {Weintraub, PG and Hoch, H and Mühlethaler, R and Zchori-Fein, E}, title = {Synchrotron X-ray micro-computed tomography as a tool for in situ elucidation of insect bacteriomes.}, journal = {Arthropod structure &amp; development}, volume = {43}, number = {2}, pages = {183-186}, doi = {10.1016/j.asd.2013.11.002}, pmid = {24291672}, issn = {1873-5495}, mesh = {Animals ; Hemiptera/*microbiology ; Microbiota ; *Synchrotrons ; X-Ray Microtomography/*methods ; }, abstract = {Obligate bacterial endosymbionts are common, influential associates of arthropods, and are often found in specific organs termed bacteriomes. Three dimensional images of bacteriomes of the leafhopper Orosius albicinctus (Hemiptera: Cicadellidae) were reconstructed from synchrotron-based X-ray micro-computed tomography (CT). Results show that bilateral bacteriomes are located between the first and second abdominal tergites, are mushroom-shaped and consist two different types of tissue. Fluorescence in situ hybridization reveals that the primary bacterial symbiont Sulcia muelleri is in the 'cap' part of the of organ. The technique allows a noninvasive, in situ, means of visualizing bacteriomes and will facilitate understanding their form and function.}, }
@article {pmid24282414, year = {2013}, author = {Tveten, AK and Riborg, A and Vadseth, HT}, title = {DGGE Identification of Microorganisms Associated with Borrelia burgdorferi Sensu Lato- or Anaplasma phagocytophilum-Infected Ixodes ricinus Ticks from Northwest Norway.}, journal = {International journal of microbiology}, volume = {2013}, number = {}, pages = {805456}, pmid = {24282414}, issn = {1687-918X}, abstract = {Ticks acquire a wide range of microorganisms as a natural part of their lifecycle. Bacteria, viruses, and protozoa can be transmitted to ticks during feeding and free-living phases. DGGE profiling is a molecular method to describe the microbial population associated with ticks and demonstrate some of the complexity and variety of tick-borne microorganisms. The present study profiled a total of 120 I. ricinus ticks, which were divided into three equally sized groups. We found that B. burgdorferi s.l.-infected ticks presented a pattern consisting of bacterial Pseudomonas spp. (67.5%), Bacillus spp. (50%), and Sphingomonas spp. (77.5%), while A. phagocytophilum-infected ticks were associated with Pseudomonas spp. (82.5%) and Sphingomonas spp. (57.5%). All profiles had one or more Pseudomonas species present, and the intramitochondrial endosymbiont Candidatus Midichloria mitochondrii was present in more than 25% of the samples. Statistical analysis demonstrated that the microbial communities were not significantly different between the groups and that the groups could not be characterised by a specific microbial population.}, }
@article {pmid24281548, year = {2014}, author = {Xie, J and Butler, S and Sanchez, G and Mateos, M}, title = {Male killing Spiroplasma protects Drosophila melanogaster against two parasitoid wasps.}, journal = {Heredity}, volume = {112}, number = {4}, pages = {399-408}, pmid = {24281548}, issn = {1365-2540}, mesh = {Animals ; Biological Evolution ; Cytoplasm/microbiology ; Defense Mechanisms ; Drosophila melanogaster/*microbiology/*parasitology ; Female ; Male ; Spiroplasma/*physiology ; Survival Analysis ; *Symbiosis ; Wasps/microbiology/*physiology ; Wolbachia ; }, abstract = {Maternally transmitted associations between endosymbiotic bacteria and insects are diverse and widespread in nature. Owing to imperfect vertical transmission, many heritable microbes have evolved compensational mechanisms to enhance their persistence in host lineages, such as manipulating host reproduction and conferring fitness benefits to host. Symbiont-mediated defense against natural enemies of hosts is increasingly recognized as an important mechanism by which endosymbionts enhance host fitness. Members of the genus Spiroplasma associated with distantly related Drosophila hosts are known to engage in either reproductive parasitism (i.e., male killing) or defense against natural enemies (the parasitic wasp Leptopilina heterotoma and a nematode). A male-killing strain of Spiroplasma (strain Melanogaster Sex Ratio Organism (MSRO)) co-occurs with Wolbachia (strain wMel) in certain wild populations of the model organism Drosophila melanogaster. We examined the effects of Spiroplasma MSRO and Wolbachia wMel on Drosophila survival against parasitism by two common wasps, Leptopilina heterotoma and Leptopilina boulardi, that differ in their host ranges and host evasion strategies. The results indicate that Spiroplasma MSRO prevents successful development of both wasps, and confers a small, albeit significant, increase in larva-to-adult survival of flies subjected to wasp attacks. We modeled the conditions under which defense can contribute to Spiroplasma persistence. Wolbachia also confers a weak, but significant, survival advantage to flies attacked by L. heterotoma. The host protective effects exhibited by Spiroplasma and Wolbachia are additive and may provide the conditions for such cotransmitted symbionts to become mutualists. Occurrence of Spiroplasma-mediated protection against distinct parasitoids in divergent Drosophila hosts suggests a general protection mechanism.}, }
@article {pmid24278221, year = {2013}, author = {Agunbiade, TA and Sun, W and Coates, BS and Djouaka, R and Tamò, M and Ba, MN and Binso-Dabire, C and Baoua, I and Olds, BP and Pittendrigh, BR}, title = {Development of reference transcriptomes for the major field insect pests of cowpea: a toolbox for insect pest management approaches in west Africa.}, journal = {PloS one}, volume = {8}, number = {11}, pages = {e79929}, pmid = {24278221}, issn = {1932-6203}, mesh = {Africa, Western ; Animals ; Fabaceae/*parasitology ; Genes, Insect ; Insecta/genetics/*physiology ; Metagenome ; *Pest Control ; Polymorphism, Single Nucleotide ; *Transcriptome ; }, abstract = {Cowpea is a widely cultivated and major nutritional source of protein for many people that live in West Africa. Annual yields and longevity of grain storage is greatly reduced by feeding damage caused by a complex of insect pests that include the pod sucking bugs, Anoplocnemis curvipes Fabricius (Hemiptera: Coreidae) and Clavigralla tomentosicollis Stål (Hemiptera: Coreidae); as well as phloem-feeding cowpea aphids, Aphis craccivora Koch (Hemiptera: Aphididae) and flower thrips, Megalurothrips sjostedti Trybom (Thysanoptera: Thripidae). Efforts to control these pests remain a challenge and there is a need to understand the structure and movement of these pest populations in order to facilitate the development of integrated pest management strategies (IPM). Molecular tools have the potential to help facilitate a better understanding of pest populations. Towards this goal, we used 454 pyrosequencing technology to generate 319,126, 176,262, 320,722 and 227,882 raw reads from A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti, respectively. The reads were de novo assembled into 11,687, 7,647, 10,652 and 7,348 transcripts for A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti, respectively. Functional annotation of the resulting transcripts identified genes putatively involved in insecticide resistance, pathogen defense and immunity. Additionally, sequences that matched the primary aphid endosymbiont, Buchnera aphidicola, were identified among A. craccivora transcripts. Furthermore, 742, 97, 607 and 180 single nucleotide polymorphisms (SNPs) were respectively predicted among A. curvipes, A. craccivora, C. tomentosicollis and M. sjostedti transcripts, and will likely be valuable tools for future molecular genetic marker development. These results demonstrate that Roche 454-based transcriptome sequencing could be useful for the development of genomic resources for cowpea pest insects in West Africa.}, }
@article {pmid24274471, year = {2014}, author = {Hamilton, PT and Leong, JS and Koop, BF and Perlman, SJ}, title = {Transcriptional responses in a Drosophila defensive symbiosis.}, journal = {Molecular ecology}, volume = {23}, number = {6}, pages = {1558-1570}, doi = {10.1111/mec.12603}, pmid = {24274471}, issn = {1365-294X}, mesh = {Animals ; Bacterial Toxins/metabolism ; Drosophila/genetics/*microbiology/*parasitology ; Gene Expression Regulation ; Genes, Bacterial ; Nematoda/*pathogenicity ; Spiroplasma/*physiology ; *Symbiosis ; Transcriptome ; }, abstract = {Inherited symbionts are ubiquitous in insects and can have important consequences for the fitness of their hosts. Many inherited symbionts defend their hosts against parasites or other natural enemies; however, the means by which most symbionts confer protection is virtually unknown. We examine the mechanisms of defence in a recently discovered case of symbiont-mediated protection, where the bacterial symbiont Spiroplasma defends the fly Drosophila neotestacea from a virulent nematode parasite, Howardula aoronymphium. Using quantitative PCR of Spiroplasma infection intensities and whole transcriptome sequencing, we attempt to distinguish between the following modes of defence: symbiont-parasite competition, host immune priming and the production of toxic factors by Spiroplasma. Our findings do not support a model of exploitative competition between Howardula and Spiroplasma to mediate defence, nor do we find strong support for host immune priming during Spiroplasma infection. Interestingly, we recovered sequence for putative toxins encoded by Spiroplasma, including a novel putative ribosome-inactivating protein, transcripts of which are up-regulated in response to nematode exposure. Protection via the production of toxins may be a widely used and important mechanism in heritable defensive symbioses in insects.}, }
@article {pmid24272923, year = {2014}, author = {Parrella, G and Nappo, AG and Manco, E and Greco, B and Giorgini, M}, title = {Invasion of the Q2 mitochondrial variant of Mediterranean Bemisia tabaci in southern Italy: possible role of bacterial endosymbionts.}, journal = {Pest management science}, volume = {70}, number = {10}, pages = {1514-1523}, doi = {10.1002/ps.3686}, pmid = {24272923}, issn = {1526-4998}, mesh = {Animals ; Bacteria/*genetics/*isolation &amp; purification ; Female ; Genetic Variation ; Hemiptera/*genetics/*microbiology ; Introduced Species ; Italy ; Male ; Mitochondria/*genetics ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; *Sex Ratio ; *Symbiosis ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci (Gennadius) is a complex of cryptic species, some of which, namely the Mediterranean (MED) and the Middle East-Asia Minor 1 (MEAM1), are highly invasive and injurious crop pests worldwide and able to displace local genotypes. Invasiveness of B. tabaci may depend on the phenotype of inherited bacterial endosymbionts. Here, the B. tabaci genetic diversity variation that has occurred in recent years in southern Italy was examined. Whitefly was genotyped by restriction fragment length polymorphism analysis of polymerase-chain-reaction-amplified fragments (PCR-RFLP) of the COI gene and molecular identification of endosymbionts. Possible factors leading to the observed genetic diversity were examined.<br><br>RESULTS: Q1 and Q2 mitochondrial types of MED, the only species found, coexisted in the field, while MEAM1 disappeared. A large spreading of Q2 (70% of individuals) was observed for the first time in Italy. Q2 showed a significant female-biased sex ratio and largely outnumbered Q1 on solanaceous hosts, in greenhouses and on insecticide-treated plants. Q1, with an even sex ratio, slightly prevailed on non-solanaceous hosts, especially on wild and untreated plants. Endosymbiont composition was associated with the mitochondrial type. Hamiltonella and Rickettsia were found at near fixation in Q1 and Q2 respectively; Arsenophonus, Cardinium and Wolbachia were found in both types, although at different frequencies.<br><br>CONCLUSIONS: Q2 invasion seems to have been favoured by the agroecological conditions of southern Italy and by the female-biased sex ratio. Endosymbionts may have a role in Q2 invasiveness, acting as sex-ratio manipulators (e.g. Rickettsia) and possibly by benefiting the host fitness.}, }
@article {pmid24271164, year = {2014}, author = {Toenshoff, ER and Szabó, G and Gruber, D and Horn, M}, title = {The pine bark Adelgid, Pineus strobi, contains two novel bacteriocyte-associated gammaproteobacterial symbionts.}, journal = {Applied and environmental microbiology}, volume = {80}, number = {3}, pages = {878-885}, pmid = {24271164}, issn = {1098-5336}, support = {P 22533/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Biological Evolution ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification/*physiology ; Hemiptera/*microbiology ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Bacterial endosymbionts of the pine bark adelgid, Pineus strobi (Insecta: Hemiptera: Adelgidae), were investigated using transmission electron microscopy, 16S and 23S rRNA-based phylogeny, and fluorescence in situ hybridization. Two morphologically different symbionts affiliated with the Gammaproteobacteria were present in distinct bacteriocytes. One of them ("Candidatus Annandia pinicola") is most closely related to an endosymbiont of Adelges tsugae, suggesting that they originate from a lineage already present in ancient adelgids before the hosts diversified into the two major clades, Adelges and Pineus. The other P. strobi symbiont ("Candidatus Hartigia pinicola") represents a novel symbiont lineage in members of the Adelgidae. Our findings lend further support for a complex evolutionary history of the association of adelgids with a phylogenetically diverse set of bacterial symbionts.}, }
@article {pmid24268094, year = {2014}, author = {Cobo-Díaz, JF and Martínez-Hidalgo, P and Fernández-González, AJ and Martínez-Molina, E and Toro, N and Velázquez, E and Fernández-López, M}, title = {The endemic Genista versicolor from Sierra Nevada National Park in Spain is nodulated by putative new Bradyrhizobium species and a novel symbiovar (sierranevadense).}, journal = {Systematic and applied microbiology}, volume = {37}, number = {3}, pages = {177-185}, doi = {10.1016/j.syapm.2013.09.008}, pmid = {24268094}, issn = {1618-0984}, mesh = {Bacterial Proteins/genetics ; Bradyrhizobium/*classification/genetics/isolation &amp; purification/*physiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Genista/*microbiology ; Molecular Sequence Data ; Phylogeny ; *Plant Root Nodulation ; Random Amplified Polymorphic DNA Technique ; Root Nodules, Plant/microbiology ; Sequence Analysis, DNA ; *Soil Microbiology ; Spain ; *Symbiosis ; }, abstract = {Genista versicolor is an endemic legume from Sierra Nevada National Park which constitutes one of the UNESCO-recognized Biosphere Reserves. In the present study, a collection of strains nodulating this legume was analysed in characteristic soils of this ecosystem. Most strains nodulating G. versicolor belonged to rrs group I within the genus Bradyrhizobium and only one strain, named GV137, belonged to rrs group II from which only a single species, B. retamae, has been described in Europe to date. Strain GV137, and some strains from rrs group I, belonged to putative new species of Bradyrhizobium, although most strains from group I belonged to B. canariense, according to the ITS fragment and atpD gene analysis. This result contrasted with those obtained in Genista tinctoria in Northeast Europe whose endosymbionts were identified as B. japonicum. The analysis of the symbiotic nodC and nifH genes carried by G. versicolor-nodulating strains showed that most of them belonged to symbiovar genistearum, as did those isolated from G. tinctoria. Nevertheless, strain GV137, belonging to rrs group II, formed a divergent lineage that constituted a novel symbiovar within the genus Bradyrhizobium for which the name sierranevadense is proposed. This finding showed that the Genisteae are not restrictive legumes only nodulated by symbiovar genistearum, since Genista is a promiscuous legume nodulated by at least two symbiovars of Bradyrhizobium, as occurs in Retama species.}, }
@article {pmid24264310, year = {2013}, author = {Boscaro, V and Schrallhammer, M and Benken, KA and Krenek, S and Szokoli, F and Berendonk, TU and Schweikert, M and Verni, F and Sabaneyeva, EV and Petroni, G}, title = {Rediscovering the genus Lyticum, multiflagellated symbionts of the order Rickettsiales.}, journal = {Scientific reports}, volume = {3}, number = {}, pages = {3305}, pmid = {24264310}, issn = {2045-2322}, mesh = {Alphaproteobacteria/classification/*genetics/ultrastructure ; Paramecium/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/chemistry/genetics ; Symbiosis ; }, abstract = {Among the bacterial symbionts harbored by the model organism Paramecium, many still lack a recent investigation that includes a molecular characterization. The genus Lyticum consists of two species of large-sized bacteria displaying numerous flagella, despite their inability to move inside their hosts' cytoplasm. We present a multidisciplinary redescription of both species, using the deposited type strains as well as newly collected material. On the basis of 16S rRNA gene sequences, we assigned Lyticum to the order Rickettsiales, that is intensely studied because of its pathogenic representatives and its position as the extant group most closely related to the mitochondrial ancestor. We provide conclusive proofs that at least some Rickettsiales possess actual flagella, a feature that has been recently predicted from genomic data but never confirmed. We give support to the hypothesis that the mitochondrial ancestor could have been flagellated, and provide the basis for further studies on these ciliate endosymbionts.}, }
@article {pmid24260300, year = {2013}, author = {Klein, CC and Alves, JM and Serrano, MG and Buck, GA and Vasconcelos, AT and Sagot, MF and Teixeira, MM and Camargo, EP and Motta, MC}, title = {Biosynthesis of vitamins and cofactors in bacterium-harbouring trypanosomatids depends on the symbiotic association as revealed by genomic analyses.}, journal = {PloS one}, volume = {8}, number = {11}, pages = {e79786}, pmid = {24260300}, issn = {1932-6203}, mesh = {Betaproteobacteria/*genetics/metabolism ; Biological Factors/*biosynthesis/genetics/metabolism ; Biosynthetic Pathways/*genetics ; Genome, Protozoan/genetics ; Genomics/methods ; Phylogeny ; Symbiosis/*genetics ; Trypanosoma/*genetics/metabolism/*microbiology ; Vitamins/*biosynthesis/genetics/metabolism ; }, abstract = {Some non-pathogenic trypanosomatids maintain a mutualistic relationship with a betaproteobacterium of the Alcaligenaceae family. Intensive nutritional exchanges have been reported between the two partners, indicating that these protozoa are excellent biological models to study metabolic co-evolution. We previously sequenced and herein investigate the entire genomes of five trypanosomatids which harbor a symbiotic bacterium (SHTs for Symbiont-Haboring Trypanosomatids) and the respective bacteria (TPEs for Trypanosomatid Proteobacterial Endosymbiont), as well as two trypanosomatids without symbionts (RTs for Regular Trypanosomatids), for the presence of genes of the classical pathways for vitamin biosynthesis. Our data show that genes for the biosynthetic pathways of thiamine, biotin, and nicotinic acid are absent from all trypanosomatid genomes. This is in agreement with the absolute growth requirement for these vitamins in all protozoa of the family. Also absent from the genomes of RTs are the genes for the synthesis of pantothenic acid, folic acid, riboflavin, and vitamin B6. This is also in agreement with the available data showing that RTs are auxotrophic for these essential vitamins. On the other hand, SHTs are autotrophic for such vitamins. Indeed, all the genes of the corresponding biosynthetic pathways were identified, most of them in the symbiont genomes, while a few genes, mostly of eukaryotic origin, were found in the host genomes. The only exceptions to the latter are: the gene coding for the enzyme ketopantoate reductase (EC:1.1.1.169) which is related instead to the Firmicutes bacteria; and two other genes, one involved in the salvage pathway of pantothenic acid and the other in the synthesis of ubiquinone, that are related to Gammaproteobacteria. Their presence in trypanosomatids may result from lateral gene transfer. Taken together, our results reinforce the idea that the low nutritional requirement of SHTs is associated with the presence of the symbiotic bacterium, which contains most genes for vitamin production.}, }
@article {pmid24255825, year = {2013}, author = {Nair, RR and Nandhini, MB and Sethuraman, T and Doss, G}, title = {Mutational pressure dictates synonymous codon usage in freshwater unicellular α - cyanobacterial descendant Paulinella chromatophora and β - cyanobacterium Synechococcus elongatus PCC6301.}, journal = {SpringerPlus}, volume = {2}, number = {}, pages = {492}, pmid = {24255825}, issn = {2193-1801}, abstract = {BACKGROUND: Comparative study of synonymous codon usage variations and factors influencing its diversification in α - cyanobacterial descendant Paulinella chromatophora and β - cyanobacterium Synechococcus elongatus PCC6301 has not been reported so far. In the present study, we investigated various factors associated with synonymous codon usage in the genomes of P. chromatophora and S. elongatus PCC6301 and findings were discussed.<br><br>RESULTS: Mutational pressure was identified as the major force behind codon usage variation in both genomes. However, correspondence analysis revealed that intensity of mutational pressure was higher in S. elongatus than in P. chromatophora. Living habitats were also found to determine synonymous codon usage variations across the genomes of P. chromatophora and S. elongatus.<br><br>CONCLUSIONS: Whole genome sequencing of &#x3b1;-cyanobacteria in the cyanobium clade would certainly facilitate the understanding of synonymous codon usage patterns and factors contributing its diversification in presumed ancestors of photosynthetic endosymbionts of P. chromatophora.}, }
@article {pmid24246912, year = {2014}, author = {Singh, R and Sripada, L and Singh, R}, title = {Side effects of antibiotics during bacterial infection: mitochondria, the main target in host cell.}, journal = {Mitochondrion}, volume = {16}, number = {}, pages = {50-54}, doi = {10.1016/j.mito.2013.10.005}, pmid = {24246912}, issn = {1872-8278}, mesh = {Anti-Bacterial Agents/*administration &amp; dosage/*adverse effects ; Bacterial Infections/*drug therapy ; Humans ; Metabolic Networks and Pathways/drug effects ; Mitochondria/*drug effects ; }, abstract = {Antibiotics are frontline therapy against microbial infectious diseases. Many antibiotics are known to cause several side effects in humans. Ribosomal RNA (rRNA) is the main target of antibiotics that inhibit protein synthesis. According to the endosymbiont theory, mitochondrion is of bacterial origin and their molecular and structural components of the protein expression system are almost similar. It has been observed that the rate of mutations in mitochondrial rRNA is higher as compared to that of nuclear rRNA. The presence of these mutations may mimic prokaryotic rRNA structure and bind to antibiotics targeted to ribosomes of bacteria. Mitochondrial functions are compromised hence may be one of the major causes of side effects observed during antibiotic therapy. The current review had summarized the studies on the role of antibiotics on mitochondrial functions and its relevance to the observed side effects in physiological and pathological conditions.}, }
@article {pmid24243963, year = {2013}, author = {Dimond, JL and Pineda, RR and Ramos-Ascherl, Z and Bingham, BL}, title = {Relationships between host and symbiont cell cycles in sea anemones and their symbiotic dinoflagellates.}, journal = {The Biological bulletin}, volume = {225}, number = {2}, pages = {102-112}, doi = {10.1086/BBLv225n2p102}, pmid = {24243963}, issn = {1939-8697}, mesh = {Animals ; Belize ; Cell Cycle ; Dinoflagellida/*cytology/*physiology ; Flow Cytometry ; Phylogeny ; Sea Anemones/*cytology/*physiology ; Seasons ; *Symbiosis ; }, abstract = {The processes by which cnidarians and their algal endosymbionts achieve balanced growth and biomass could include coordination of host and symbiont cell cycles. We evaluated this theory with natural populations of sea anemones hosting symbiotic dinoflagellates, focusing on the temperate sea anemone Anthopleura elegantissima symbiotic with Symbiodinium muscatinei in Washington State, USA, and the tropical anemone Stichodactyla helianthus associating with unknown Symbiodinium spp. in Belize. By extruding symbiont-containing gastrodermal cells from the relatively large tentacles of these species and using nuclear staining and flow cytometry, we selectively analyzed cell cycle distributions of the symbionts and the host gastrodermal cells that house them. We found no indications of diel synchrony in host and symbiont G2/M phases, and we observed evidence of diel periodicity only in Symbiodinium spp. associated with S. helianthus but not in the anemone itself. Seasonally, S. muscatinei showed considerable G2/M phase variability among samples collected quarterly over an annual period, while the G2/M phase of its host varied much less. Within samples taken at different times of the year, correlations between host and symbiont G2/M phases ranged from very weakly to very strongly positive, with significant correlations in only half of the samples (two of four A. elegantissima samples and one of two S. helianthus samples). Overall, the G2/M phase relationships across species and sampling periods were positive. Thus, while we found no evidence of close cell cycle coupling, our results suggest a loose, positive relationship between cell cycle processes of the symbiotic partners.}, }
@article {pmid24239274, year = {2014}, author = {Díaz-Alcántara, CA and Ramírez-Bahena, MH and Mulas, D and García-Fraile, P and Gómez-Moriano, A and Peix, A and Velázquez, E and González-Andrés, F}, title = {Analysis of rhizobial strains nodulating Phaseolus vulgaris from Hispaniola Island, a geographic bridge between Meso and South America and the first historical link with Europe.}, journal = {Systematic and applied microbiology}, volume = {37}, number = {2}, pages = {149-156}, doi = {10.1016/j.syapm.2013.09.005}, pmid = {24239274}, issn = {1618-0984}, mesh = {*Biota ; Central America ; Molecular Sequence Data ; Phaseolus/*microbiology ; *Phylogeography ; Rhizobium/*classification/genetics ; Rhizobium phaseoli/*classification/genetics/*isolation &amp; purification ; Root Nodules, Plant/*microbiology ; Sequence Analysis, DNA ; South America ; }, abstract = {Hispaniola Island was the first stopover in the travels of Columbus between America and Spain, and played a crucial role in the exchange of Phaseolus vulgaris seeds and their endosymbionts. The analysis of recA and atpD genes from strains nodulating this legume in coastal and inner regions of Hispaniola Island showed that they were almost identical to those of the American strains CIAT 652, Ch24-10 and CNPAF512, which were initially named as Rhizobium etli and have been recently reclassified into Rhizobium phaseoli after the analysis of their genomes. Therefore, the species R. phaseoli is more abundant in America than previously thought, and since the proposal of the American origin of R. etli was based on the analysis of several strains that are currently known to be R. phaseoli, it can be concluded that both species have an American origin coevolving with their host in its distribution centres. The analysis of the symbiovar phaseoli nodC gene alleles carried by different species isolated in American and European countries suggested a Mesoamerican origin of the α allele and an Andean origin of the γ allele, which is supported by the dominance of this latter allele in Europe where mostly Andean cultivars of common beans have been traditionally cultivated.}, }
@article {pmid24233285, year = {2014}, author = {Brady, CM and Asplen, MK and Desneux, N and Heimpel, GE and Hopper, KR and Linnen, CR and Oliver, KM and Wulff, JA and White, JA}, title = {Worldwide populations of the aphid Aphis craccivora are infected with diverse facultative bacterial symbionts.}, journal = {Microbial ecology}, volume = {67}, number = {1}, pages = {195-204}, pmid = {24233285}, issn = {1432-184X}, mesh = {Animals ; Aphids/genetics/*microbiology ; Bacteria/*classification/genetics/isolation &amp; purification ; Biodiversity ; Haplotypes ; Medicago sativa ; Mitochondria/genetics ; Molecular Sequence Data ; Robinia ; *Symbiosis ; }, abstract = {Facultative bacterial endosymbionts can play an important role in the evolutionary trajectory of their hosts. Aphids (Hemiptera: Aphididae) are infected with a wide variety of facultative endosymbionts that can confer ecologically relevant traits, which in turn may drive microevolutionary processes in a dynamic selective environment. However, relatively little is known about how symbiont diversity is structured in most aphid species. Here, we investigate facultative symbiont species richness and prevalence among world-wide populations of the cowpea aphid, Aphis craccivora Koch. We surveyed 44 populations of A. craccivora, and detected 11 strains of facultative symbiotic bacteria, representing six genera. There were two significant associations between facultative symbiont and aphid food plant: the symbiont Arsenophonus was found at high prevalence in A. craccivora populations collected from Robinia sp. (locust), whereas the symbiont Hamiltonella was almost exclusively found in A. craccivora populations from Medicago sativa (alfalfa). Aphids collected from these two food plants also had divergent mitochondrial haplotypes, potentially indicating the formation of specialized aphid lineages associated with food plant (host-associated differentiation). The role of facultative symbionts in this process remains to be determined. Overall, observed facultative symbiont prevalence in A. craccivora was lower than that of some other well-studied aphids (e.g., Aphis fabae and Acyrthosiphon pisum), possibly as a consequence of A. craccivora's almost purely parthenogenetic life history. Finally, most (70 %) of the surveyed populations were polymorphic for facultative symbiont infection, indicating that even when symbiont prevalence is relatively low, symbiont-associated phenotypic variation may allow population-level evolutionary responses to local selection.}, }
@article {pmid24231291, year = {2014}, author = {Gong, J and Qing, Y and Guo, X and Warren, A}, title = {"Candidatus Sonnebornia yantaiensis", a member of candidate division OD1, as intracellular bacteria of the ciliated protist Paramecium bursaria (Ciliophora, Oligohymenophorea).}, journal = {Systematic and applied microbiology}, volume = {37}, number = {1}, pages = {35-41}, doi = {10.1016/j.syapm.2013.08.007}, pmid = {24231291}, issn = {1618-0984}, mesh = {Bacteria/*classification/genetics/*isolation &amp; purification/ultrastructure ; China ; Cluster Analysis ; Cytoplasm/microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Fresh Water ; In Situ Hybridization, Fluorescence ; Microbial Consortia ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Paramecium/*microbiology ; Phylogeny ; Ponds/*microbiology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {An intracellular bacterium was discovered in an isolate of Paramecium bursaria from a freshwater pond in Yantai, China. The bacteria were abundant and exclusively found in the cytoplasm of the host which, along with the green alga Chlorella, formed a three-partner consortium that could survive in pure water for at least one week. Cloning, sequencing and phylogenetic analysis of the bacterial 16S rRNA gene showed that the bacterium belonged to the uncultured candidate division OD1, which usually forms part of the rare biosphere. Transmission electron microscopy and fluorescence in situ hybridization (FISH) with specific probes showed that the bacteria were usually located close to the perialgal membranes of endosymbiotic Chlorella cells, and occasionally irregularly distributed throughout the host cytoplasm. The name "Candidatus Sonnebornia yantaiensis" gen. nov., sp. nov. is proposed for the new bacterium. A strongly supported monophyletic subclade, OD1-p, which included the new species, was recognized and this study highlights that protists can be important hosts for rare bacterial taxa.}, }
@article {pmid24225886, year = {2014}, author = {Goffredi, SK and Yi, H and Zhang, Q and Klann, JE and Struve, IA and Vrijenhoek, RC and Brown, CT}, title = {Genomic versatility and functional variation between two dominant heterotrophic symbionts of deep-sea Osedax worms.}, journal = {The ISME journal}, volume = {8}, number = {4}, pages = {908-924}, pmid = {24225886}, issn = {1751-7370}, support = {R01 HG007513/HG/NHGRI NIH HHS/United States ; }, mesh = {Adaptation, Physiological ; Animals ; Carbon Radioisotopes/analysis ; Female ; Gammaproteobacteria/classification/genetics/metabolism/*physiology ; Genes, Bacterial/genetics ; *Genetic Variation ; Genome, Bacterial/*genetics ; Heterotrophic Processes ; Molecular Sequence Data ; Phylogeny ; Polychaeta/*microbiology ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {An unusual symbiosis, first observed at ~3000 m depth in the Monterey Submarine Canyon, involves gutless marine polychaetes of the genus Osedax and intracellular endosymbionts belonging to the order Oceanospirillales. Ecologically, these worms and their microbial symbionts have a substantial role in the cycling of carbon from deep-sea whale fall carcasses. Microheterogeneity exists among the Osedax symbionts examined so far, and in the present study the genomes of the two dominant symbionts, Rs1 and Rs2, were sequenced. The genomes revealed heterotrophic versatility in carbon, phosphate and iron uptake, strategies for intracellular survival, evidence for an independent existence, and numerous potential virulence capabilities. The presence of specific permeases and peptidases (of glycine, proline and hydroxyproline), and numerous peptide transporters, suggests the use of degraded proteins, likely originating from collagenous bone matter, by the Osedax symbionts. (13)C tracer experiments confirmed the assimilation of glycine/proline, as well as monosaccharides, by Osedax. The Rs1 and Rs2 symbionts are genomically distinct in carbon and sulfur metabolism, respiration, and cell wall composition, among others. Differences between Rs1 and Rs2 and phylogenetic analysis of chemotaxis-related genes within individuals of symbiont Rs1 revealed the influence of the relative age of the whale fall environment and support possible local niche adaptation of 'free-living' lifestages. Future genomic examinations of other horizontally-propogated intracellular symbionts will likely enhance our understanding of the contribution of intraspecific symbiont diversity to the ecological diversification of the intact association, as well as the maintenance of host diversity.}, }
@article {pmid24223906, year = {2013}, author = {Pettay, DT and Lajeunesse, TC}, title = {Long-range dispersal and high-latitude environments influence the population structure of a "stress-tolerant" dinoflagellate endosymbiont.}, journal = {PloS one}, volume = {8}, number = {11}, pages = {e79208}, pmid = {24223906}, issn = {1932-6203}, support = {S11 ES011181/ES/NIEHS NIH HHS/United States ; ES11181/ES/NIEHS NIH HHS/United States ; }, mesh = {Acclimatization ; Analysis of Variance ; Animals ; Anthozoa/*growth &amp; development/parasitology ; Dinoflagellida/genetics/*growth &amp; development/physiology ; *Ecosystem ; *Environment ; Gene Frequency ; Genetic Variation ; Genotype ; Geography ; Host-Parasite Interactions/radiation effects ; Larva/growth &amp; development/parasitology ; Light ; Microsatellite Repeats/genetics ; Pacific Ocean ; Population Dynamics ; Seasons ; Stress, Physiological ; Symbiosis ; Temperature ; Tropical Climate ; }, abstract = {The migration and dispersal of stress-tolerant symbiotic dinoflagellates (genus Symbiodinium) may influence the response of symbiotic reef-building corals to a warming climate. We analyzed the genetic structure of the stress-tolerant endosymbiont, Symbiodinium glynni nomen nudum (ITS2 - D1), obtained from Pocillopora colonies that dominate eastern Pacific coral communities. Eleven microsatellite loci identified genotypically diverse populations with minimal genetic subdivision throughout the Eastern Tropical Pacific, encompassing 1000's of square kilometers from mainland Mexico to the Galapagos Islands. The lack of population differentiation over these distances corresponds with extensive regional host connectivity and indicates that Pocillopora larvae, which maternally inherit their symbionts, aid in the dispersal of this symbiont. In contrast to its host, however, subtropical populations of S. glynni in the Gulf of California (Sea of Cortez) were strongly differentiated from populations in tropical eastern Pacific. Selection pressures related to large seasonal fluctuations in temperature and irradiance likely explain this abrupt genetic discontinuity. We infer that S. glynni genotypes harbored by host larvae arriving from more southern locations are rapidly replaced by genotypes adapted to more temperate environments. The strong population structure of S. glynni corresponds with fluctuating environmental conditions and suggests that these genetically diverse populations have the potential to evolve rapidly to changing environments and reveals the importance of environmental extremes in driving microbial eukaryote (e.g., plankton) speciation in marine ecosystems.}, }
@article {pmid24217873, year = {2013}, author = {Olson, ND and Lesser, MP}, title = {Diazotrophic diversity in the Caribbean coral, Montastraea cavernosa.}, journal = {Archives of microbiology}, volume = {195}, number = {12}, pages = {853-859}, doi = {10.1007/s00203-013-0937-z}, pmid = {24217873}, issn = {1432-072X}, mesh = {Animals ; Anthozoa/*microbiology ; Bacteria/classification/genetics ; *Biodiversity ; Caribbean Region ; Cyanobacteria/classification/genetics ; Genetic Variation ; Nitrogen Fixation/genetics ; Oxidoreductases/genetics ; }, abstract = {Previous research on the Caribbean coral Montastraea cavernosa reported the presence of cyanobacterial endosymbionts and nitrogen fixation in orange, but not brown, colonies. We compared the diversity of nifH gene sequences between these two color morphs at three locations in the Caribbean and found that the nifH sequences recovered from M. cavernosa were consistent with previous studies on corals where members of both the α-proteobacteria and cyanobacteria were recovered. A number of nifH operational taxonomic units (OTUs) were significantly more abundant in the orange compared to the brown morphs, and one specific OTU (OTU 17), a cyanobacterial nifH sequence similar to others from corals and sponges and related to the cyanobacterial genus Cyanothece, was found in all orange morphs of M. cavernosa at all locations. The nifH diversity reported here, from a community perspective, was not significantly different between orange and brown morphs of M. cavernosa.}, }
@article {pmid24216442, year = {2013}, author = {Zhang, YK and Ding, XL and Zhang, KJ and Hong, XY}, title = {Wolbachia play an important role in affecting mtDNA variation of Tetranychus truncatus (Trombidiformes: Tetranychidae).}, journal = {Environmental entomology}, volume = {42}, number = {6}, pages = {1240-1245}, doi = {10.1603/EN13085}, pmid = {24216442}, issn = {1938-2936}, mesh = {Animals ; DNA, Mitochondrial/*genetics ; Female ; Genetic Variation ; Haplotypes ; Phylogeny ; Tetranychidae/genetics/*microbiology ; Wolbachia/*genetics/physiology ; }, abstract = {The prevalence of the endosymbiont Wolbachia and its effects on mitochondria variation were analyzed in seven natural populations of Tetranychus truncatus Ehara (Trombidiformes: Tetranychidae) in current study. Five Wolbachia strains (wtru1, wtru5, wtru7, wtru8, and wtru12) were detected based on the surface protein of Wolbachia (wsp) sequence data and the multiple locus sequences typing data, suggesting that multiple separate invasions have occurred. Part of mitochondrial cytochrome oxidase subunit I gene was sequenced from infected individuals revealing 10 different haplotypes. As predicted, the haplotype and nucleotide diversity were lower in infected individuals than that in uninfected individuals. Furthermore, phylogenetic and analysis of molecular variance analyses revealed that the distribution of mtDNA haplotypes is not associated with geography. Rather, it is strongly concordant with infection status. These data support the hypothesis that Wolbachia infection can affect the genetic structure and diversity of the host mites.}, }
@article {pmid24214947, year = {2014}, author = {Xie, H and Buschmann, S and Langer, JD and Ludwig, B and Michel, H}, title = {Biochemical and biophysical characterization of the two isoforms of cbb3-type cytochrome c oxidase from Pseudomonas stutzeri.}, journal = {Journal of bacteriology}, volume = {196}, number = {2}, pages = {472-482}, pmid = {24214947}, issn = {1098-5530}, mesh = {Calorimetry ; Catalase/metabolism ; Chromatography, Affinity ; Electron Transport Complex IV/chemistry/genetics/isolation &amp; purification/*metabolism ; Enzyme Stability ; Gene Expression ; Hydrogen-Ion Concentration ; Kinetics ; Mass Spectrometry ; Oxidoreductases/metabolism ; Protein Isoforms/chemistry/genetics/isolation &amp; purification/metabolism ; Pseudomonas stutzeri/*enzymology/genetics ; Spectrophotometry, Ultraviolet ; Temperature ; }, abstract = {The cbb3-type cytochrome c oxidases (cbb3-CcOs) are members of the heme-copper oxidase superfamily that couple the reduction of oxygen to translocation of protons across the membrane. The cbb3-CcOs are present only in bacteria and play a primary role in microaerobic respiration, being essential for nitrogen-fixing endosymbionts and for some human pathogens. As frequently observed in Pseudomonads, Pseudomonas stutzeri contains two independent ccoNO(Q)P operons encoding the two cbb3 isoforms, Cbb3-1 and Cbb3-2. While the crystal structure of Cbb3-1 from P. stutzeri was determined recently and cbb3-CcOs from other organisms were characterized functionally, less emphasis has been placed on the isoform-specific differences between the cbb3-CcOs. In this work, both isoforms were homologously expressed in P. stutzeri strains from which the genomic version of the respective operon was deleted. We purified both cbb3 isoforms separately by affinity chromatography and increased the yield of Cbb3-2 to a similar level as Cbb3-1 by replacing its native promoter. Mass spectrometry, UV-visible (UV-Vis) spectroscopy, differential scanning calorimetry, as well as oxygen reductase and catalase activity measurements were employed to characterize both cbb3 isoforms. Differences were found concerning the thermal stability and the presence of subunit CcoQ. However, no significant differences between the two isoforms were observed otherwise. Interestingly, a surprisingly high turnover of at least 2,000 electrons s(-1) and a high Michaelis-Menten constant (Km ~ 3.6 mM) using ascorbate-N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride (TMPD) as the electron donor were characteristic for both P. stutzeri cbb3-CcOs. Our work provides the basis for further mutagenesis studies of each of the two cbb3 isoforms specifically.}, }
@article {pmid24204799, year = {2013}, author = {López-Madrigal, S and Balmand, S and Latorre, A and Heddi, A and Moya, A and Gil, R}, title = {How does Tremblaya princeps get essential proteins from its nested partner Moranella endobia in the Mealybug Planoccocus citri?.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e77307}, pmid = {24204799}, issn = {1932-6203}, mesh = {Animals ; Bacterial Proteins/*genetics/metabolism ; Betaproteobacteria/*genetics/metabolism ; DNA, Bacterial/*genetics/metabolism ; Gammaproteobacteria/*genetics/metabolism ; *Gene Expression Regulation, Bacterial ; Genome Size ; *Genome, Bacterial ; Molecular Sequence Annotation ; Planococcus Insect/metabolism/microbiology ; Protein Transport ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Many insects maintain intracellular mutualistic symbiosis with a wide range of bacteria which are considered essential for their survival (primary or P-endosymbiont) and typically suffer drastic genome degradation. Progressive loss of P-endosymbiont metabolic capabilities could lead to the recruitment of co-existent facultative endosymbiont (secondary or S-endosymbiont), thus adding more complexity to the symbiotic system. Planococcus citri, among other mealybug species, harbors an unconventional nested endosymbiotic system where every Tremblaya princeps cell (β-proteobacterium) harbors many Moranella endobia cells (γ-proteobacterium). In this system, T. princeps possess one of the smallest prokaryote genome known so far. This extreme genome reduction suggests the supply of many metabolites and essential gene products by M. endobia. Although sporadic cell lysis is plausible, the bacterial participation on the regulation of the predicted molecular exchange (at least to some extent) cannot be excluded. Although the comprehensive analysis of the protein translocation ability of M. endobia PCVAL rules out the existence of specific mechanisms for the exportation of proteins from M. endobia to T. princeps, immunolocation of two M. endobia proteins points towards a non-massive but controlled protein provision. We propose a sporadic pattern for the predicted protein exportation events, which could be putatively controlled by the host and/or mediated by local osmotic stress.}, }
@article {pmid24204251, year = {2013}, author = {Pinto, SB and Stainton, K and Harris, S and Kambris, Z and Sutton, ER and Bonsall, MB and Parkhill, J and Sinkins, SP}, title = {Transcriptional regulation of Culex pipiens mosquitoes by Wolbachia influences cytoplasmic incompatibility.}, journal = {PLoS pathogens}, volume = {9}, number = {10}, pages = {e1003647}, pmid = {24204251}, issn = {1553-7374}, support = {//Wellcome Trust/United Kingdom ; 076964/WT_/Wellcome Trust/United Kingdom ; 079059/WT_/Wellcome Trust/United Kingdom ; 095121/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Culex/genetics/metabolism/microbiology ; Drosophila melanogaster ; Female ; Gene Knockdown Techniques ; Genome, Bacterial/physiology ; *Infertility, Female/genetics/metabolism/microbiology ; *Insect Proteins/biosynthesis/genetics ; Male ; Meiosis/genetics ; *Transcription Factors/biosynthesis/genetics ; *Up-Regulation ; *Wolbachia/genetics/metabolism ; Zinc Fingers/genetics ; }, abstract = {Cytoplasmic incompatibility (CI) induced by the endosymbiont Wolbachia pipientis causes complex patterns of crossing sterility between populations of the Culex pipiens group of mosquitoes. The molecular basis of the phenotype is yet to be defined. In order to investigate what host changes may underlie CI at the molecular level, we examined the transcription of a homolog of the Drosophila melanogaster gene grauzone that encodes a zinc finger protein and acts as a regulator of female meiosis, in which mutations can cause sterility. Upregulation was observed in Wolbachia-infected C. pipiens group individuals relative to Wolbachia-cured lines and the level of upregulation differed between lines that were reproductively incompatible. Knockdown analysis of this gene using RNAi showed an effect on hatch rates in a Wolbachia infected Culex molestus line. Furthermore, in later stages of development an effect on developmental progression in CI embryos occurs in bidirectionally incompatible crosses. The genome of a wPip Wolbachia strain variant from Culex molestus was sequenced and compared with the genome of a wPip variant with which it was incompatible. Three genes in inserted or deleted regions were newly identified in the C. molestus wPip genome, one of which is a transcriptional regulator labelled wtrM. When this gene was transfected into adult Culex mosquitoes, upregulation of the grauzone homolog was observed. These data suggest that Wolbachia-mediated regulation of host gene expression is a component of the mechanism of cytoplasmic incompatibility.}, }
@article {pmid24190075, year = {2013}, author = {Woolfit, M and Iturbe-Ormaetxe, I and Brownlie, JC and Walker, T and Riegler, M and Seleznev, A and Popovici, J and Rancès, E and Wee, BA and Pavlides, J and Sullivan, MJ and Beatson, SA and Lane, A and Sidhu, M and McMeniman, CJ and McGraw, EA and O'Neill, SL}, title = {Genomic evolution of the pathogenic Wolbachia strain, wMelPop.}, journal = {Genome biology and evolution}, volume = {5}, number = {11}, pages = {2189-2204}, pmid = {24190075}, issn = {1759-6653}, mesh = {Aedes/microbiology ; Animals ; Base Sequence ; Cell Line ; Drosophila melanogaster/microbiology ; *Evolution, Molecular ; Gene Duplication ; *Genome, Bacterial ; Molecular Sequence Data ; Mutation ; Selection, Genetic ; Virulence/genetics ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Most strains of the widespread endosymbiotic bacterium Wolbachia pipientis are benign or behave as reproductive parasites. The pathogenic strain wMelPop is a striking exception, however: it overreplicates in its insect hosts and causes severe life shortening. The mechanism of this pathogenesis is currently unknown. We have sequenced the genomes of three variants of wMelPop and of the closely related nonpathogenic strain wMelCS. We show that the genomes of wMelCS and wMelPop appear to be identical in the nonrepeat regions of the genome and differ detectably only by the triplication of a 19-kb region that is unlikely to be associated with life shortening, demonstrating that dramatic differences in the host phenotype caused by this endosymbiont may be the result of only minor genetic changes. We also compare the genomes of the original wMelPop strain from Drosophila melanogaster and two sequential derivatives, wMelPop-CLA and wMelPop-PGYP. To develop wMelPop as a novel biocontrol agent, it was first transinfected into and passaged in mosquito cell lines for approximately 3.5 years, generating wMelPop-CLA. This cell line-passaged strain was then transinfected into Aedes aegypti mosquitoes, creating wMelPop-PGYP, which was sequenced after 4 years in the insect host. We observe a rapid burst of genomic changes during cell line passaging, but no further mutations were detected after transinfection into mosquitoes, indicating either that host preadaptation had occurred in cell lines, that cell lines are a more selectively permissive environment than animal hosts, or both. Our results provide valuable data on the rates of genomic and phenotypic change in Wolbachia associated with host shifts over short time scales.}, }
@article {pmid24188869, year = {2014}, author = {Bogumil, D and Alvarez-Ponce, D and Landan, G and McInerney, JO and Dagan, T}, title = {Integration of two ancestral chaperone systems into one: the evolution of eukaryotic molecular chaperones in light of eukaryogenesis.}, journal = {Molecular biology and evolution}, volume = {31}, number = {2}, pages = {410-418}, pmid = {24188869}, issn = {1537-1719}, support = {281357/ERC_/European Research Council/International ; }, mesh = {Archaea/*genetics/metabolism ; Bacteria/*genetics/metabolism ; *Biological Evolution ; Eukaryota/*genetics/metabolism ; Histone Chaperones/*genetics ; Models, Molecular ; Phylogeny ; Protein Folding ; Saccharomyces cerevisiae/*genetics/metabolism ; Saccharomyces cerevisiae Proteins/genetics/metabolism ; Symbiosis ; }, abstract = {Eukaryotic genomes are mosaics of genes acquired from their prokaryotic ancestors, the eubacterial endosymbiont that gave rise to the mitochondrion and its archaebacterial host. Genomic footprints of the prokaryotic merger at the origin of eukaryotes are still discernable in eukaryotic genomes, where gene expression and function correlate with their prokaryotic ancestry. Molecular chaperones are essential in all domains of life as they assist the functional folding of their substrate proteins and protect the cell against the cytotoxic effects of protein misfolding. Eubacteria and archaebacteria code for slightly different chaperones, comprising distinct protein folding pathways. Here we study the evolution of the eukaryotic protein folding pathways following the endosymbiosis event. A phylogenetic analysis of all 64 chaperones encoded in the Saccharomyces cerevisiae genome revealed 25 chaperones of eubacterial ancestry, 11 of archaebacterial ancestry, 10 of ambiguous prokaryotic ancestry, and 18 that may represent eukaryotic innovations. Several chaperone families (e.g., Hsp90 and Prefoldin) trace their ancestry to only one prokaryote group, while others, such as Hsp40 and Hsp70, are of mixed ancestry, with members contributed from both prokaryotic ancestors. Analysis of the yeast chaperone-substrate interaction network revealed no preference for interaction between chaperones and substrates of the same origin. Our results suggest that the archaebacterial and eubacterial protein folding pathways have been reorganized and integrated into the present eukaryotic pathway. The highly integrated chaperone system of yeast is a manifestation of the central role of chaperone-mediated folding in maintaining cellular fitness. Most likely, both archaebacterial and eubacterial chaperone systems were essential at the very early stages of eukaryogenesis, and the retention of both may have offered new opportunities for expanding the scope of chaperone-mediated folding.}, }
@article {pmid24185857, year = {2014}, author = {Laughton, AM and Fan, MH and Gerardo, NM}, title = {The combined effects of bacterial symbionts and aging on life history traits in the pea aphid, Acyrthosiphon pisum.}, journal = {Applied and environmental microbiology}, volume = {80}, number = {2}, pages = {470-477}, pmid = {24185857}, issn = {1098-5336}, mesh = {Aging/*physiology ; Animals ; Aphids/immunology/*microbiology/*physiology ; Buchnera/genetics/*physiology ; Embryo, Nonmammalian ; Female ; Fertility/genetics ; Mortality ; Reproduction ; Symbiosis/*physiology ; }, abstract = {While many endosymbionts have beneficial effects on hosts under specific ecological conditions, there can also be associated costs. In order to maximize their own fitness, hosts must facilitate symbiont persistence while preventing symbiont exploitation of resources, which may require tight regulation of symbiont populations. As a host ages, the ability to invest in such mechanisms may lessen or be traded off with demands of other life history traits, such as survival and reproduction. Using the pea aphid, Acyrthosiphon pisum, we measured survival, lifetime fecundity, and immune cell counts (hemocytes, a measure of immune capacity) in the presence of facultative secondary symbionts. Additionally, we quantified the densities of the obligate primary bacterial symbiont, Buchnera aphidicola, and secondary symbionts across the host's lifetime. We found life history costs to harboring some secondary symbiont species. Secondary symbiont populations were found to increase with host age, while Buchnera populations exhibited a more complicated pattern. Immune cell counts peaked at the midreproductive stage before declining in the oldest aphids. The combined effects of immunosenescence and symbiont population growth may have important consequences for symbiont transmission and maintenance within a host population.}, }
@article {pmid24176055, year = {2013}, author = {Ponce-de-León, M and Montero, F and Peretó, J}, title = {Solving gap metabolites and blocked reactions in genome-scale models: application to the metabolic network of Blattabacterium cuenoti.}, journal = {BMC systems biology}, volume = {7}, number = {}, pages = {114}, pmid = {24176055}, issn = {1752-0509}, mesh = {Bacteroidetes/*genetics/*metabolism ; *Genomics ; *Metabolic Networks and Pathways ; *Models, Biological ; Symbiosis ; }, abstract = {BACKGROUND: Metabolic reconstruction is the computational-based process that aims to elucidate the network of metabolites interconnected through reactions catalyzed by activities assigned to one or more genes. Reconstructed models may contain inconsistencies that appear as gap metabolites and blocked reactions. Although automatic methods for solving this problem have been previously developed, there are many situations where manual curation is still needed.<br><br>RESULTS: We introduce a general definition of gap metabolite that allows its detection in a straightforward manner. Moreover, a method for the detection of Unconnected Modules, defined as isolated sets of blocked reactions connected through gap metabolites, is proposed. The method has been successfully applied to the curation of iCG238, the genome-scale metabolic model for the bacterium Blattabacterium cuenoti, obligate endosymbiont of cockroaches.<br><br>CONCLUSION: We found the proposed approach to be a valuable tool for the curation of genome-scale metabolic models. The outcome of its application to the genome-scale model B. cuenoti iCG238 is a more accurate model version named as B. cuenoti iMP240.}, }
@article {pmid24167113, year = {2014}, author = {Vorburger, C}, title = {The evolutionary ecology of symbiont-conferred resistance to parasitoids in aphids.}, journal = {Insect science}, volume = {21}, number = {3}, pages = {251-264}, doi = {10.1111/1744-7917.12067}, pmid = {24167113}, issn = {1744-7917}, mesh = {Animals ; Aphids/*parasitology/*physiology ; *Biological Evolution ; Communicable Disease Control ; *Ecological and Environmental Phenomena ; *Host-Parasite Interactions ; *Symbiosis ; }, abstract = {Aphids may harbor a wide variety of facultative bacterial endosymbionts. These symbionts are transmitted maternally with high fidelity and they show horizontal transmission as well, albeit at rates too low to enable infectious spread. Such symbionts need to provide a net fitness benefit to their hosts to persist and spread. Several symbionts have achieved this by evolving the ability to protect their hosts against parasitoids. Reviewing empirical work and some models, I explore the evolutionary ecology of symbiont-conferred resistance to parasitoids in order to understand how defensive symbiont frequencies are maintained at the intermediate levels observed in aphid populations. I further show that defensive symbionts alter the reciprocal selection between aphids and parasitoids by augmenting the heritable variation for resistance, by increasing the genetic specificity of the host-parasitoid interaction, and by inducing environment-dependent trade-offs. These effects are conducive to very dynamic, symbiont-mediated coevolution that is driven by frequency-dependent selection. Finally I argue that defensive symbionts represent a problem for biological control of pest aphids, and I propose to mitigate this problem by exploiting the parasitoids' demonstrated ability to rapidly evolve counteradaptations to symbiont-conferred resistance.}, }
@article {pmid24164708, year = {2014}, author = {Awrahman, ZA and Champion de Crespigny, F and Wedell, N}, title = {The impact of Wolbachia, male age and mating history on cytoplasmic incompatibility and sperm transfer in Drosophila simulans.}, journal = {Journal of evolutionary biology}, volume = {27}, number = {1}, pages = {1-10}, doi = {10.1111/jeb.12270}, pmid = {24164708}, issn = {1420-9101}, mesh = {Aging/physiology ; Animals ; *Copulation ; Drosophila simulans/microbiology/*physiology ; Female ; Male ; Reproductive Isolation ; Wolbachia/*physiology ; }, abstract = {Most insects harbour a variety of maternally inherited endosymbionts, the most widespread being Wolbachia pipientis that commonly induce cytoplasmic incompatibility (CI) and reduced hatching success in crosses between infected males and uninfected females. High temperature and increasing male age are known to reduce the level of CI in a variety of insects. In Drosophila simulans, infected males have been shown to mate at a higher rate than uninfected males. By examining the impact of mating rate independent of age, this study investigates whether a high mating rate confers an advantage to infected males through restoring their compatibility with uninfected females over and above the effect of age. The impact of Wolbachia infection, male mating rate and age on the number of sperm transferred to females during copulation and how it relates to CI expression was also assessed. As predicted, we found that reproductive compatibility was restored faster in males that mate at higher rate than that of low mating and virgin males, and that the effect of mating history was over and above the effect of male age. Nonvirgin infected males transferred fewer sperm than uninfected males during copulation, and mating at a high rate resulted in the transfer of fewer sperm per mating irrespective of infection status. These results indicate that the advantage to infected males of mating at a high rate is through restoration of reproductive compatibility with uninfected females, whereas uninfected males appear to trade off the number of sperm transferred per mating with female encounter rate and success in sperm competition. This study highlights the importance Wolbachia may play in sexual selection by affecting male reproductive strategies.}, }
@article {pmid24156600, year = {2013}, author = {Yue, J and Sun, G and Hu, X and Huang, J}, title = {The scale and evolutionary significance of horizontal gene transfer in the choanoflagellate Monosiga brevicollis.}, journal = {BMC genomics}, volume = {14}, number = {1}, pages = {729}, pmid = {24156600}, issn = {1471-2164}, mesh = {Bacteria/genetics ; Biological Evolution ; Chlorophyta/genetics ; Choanoflagellata/classification/*genetics ; Databases, Genetic ; *Gene Transfer, Horizontal ; *Genome, Protozoan ; Phylogeny ; }, abstract = {BACKGROUND: It is generally agreed that horizontal gene transfer (HGT) is common in phagotrophic protists. However, the overall scale of HGT and the cumulative impact of acquired genes on the evolution of these organisms remain largely unknown.<br><br>RESULTS: Choanoflagellates are phagotrophs and the closest living relatives of animals. In this study, we performed phylogenomic analyses to investigate the scale of HGT and the evolutionary importance of horizontally acquired genes in the choanoflagellate Monosiga brevicollis. Our analyses identified 405 genes that are likely derived from algae and prokaryotes, accounting for approximately 4.4% of the Monosiga nuclear genome. Many of the horizontally acquired genes identified in Monosiga were probably acquired from food sources, rather than by endosymbiotic gene transfer (EGT) from obsolete endosymbionts or plastids. Of 193 genes identified in our analyses with functional information, 84 (43.5%) are involved in carbohydrate or amino acid metabolism, and 45 (23.3%) are transporters and/or involved in response to oxidative, osmotic, antibiotic, or heavy metal stresses. Some identified genes may also participate in biosynthesis of important metabolites such as vitamins C and K12, porphyrins and phospholipids.<br><br>CONCLUSIONS: Our results suggest that HGT is frequent in Monosiga brevicollis and might have contributed substantially to its adaptation and evolution. This finding also highlights the importance of HGT in the genome and organismal evolution of phagotrophic eukaryotes.}, }
@article {pmid24153189, year = {2013}, author = {Raina, JB and Tapiolas, DM and Forêt, S and Lutz, A and Abrego, D and Ceh, J and Seneca, FO and Clode, PL and Bourne, DG and Willis, BL and Motti, CA}, title = {DMSP biosynthesis by an animal and its role in coral thermal stress response.}, journal = {Nature}, volume = {502}, number = {7473}, pages = {677-680}, pmid = {24153189}, issn = {1476-4687}, mesh = {Acrylates/analysis/metabolism ; Algal Proteins/genetics ; Animals ; Anthozoa/genetics/metabolism/*physiology ; Climate Change ; Photosynthesis ; Secondary Metabolism ; *Stress, Physiological ; Sulfonium Compounds/*metabolism ; Symbiosis ; *Temperature ; Time Factors ; }, abstract = {Globally, reef-building corals are the most prolific producers of dimethylsulphoniopropionate (DMSP), a central molecule in the marine sulphur cycle and precursor of the climate-active gas dimethylsulphide. At present, DMSP production by corals is attributed entirely to their algal endosymbiont, Symbiodinium. Combining chemical, genomic and molecular approaches, we show that coral juveniles produce DMSP in the absence of algal symbionts. DMSP levels increased up to 54% over time in newly settled coral juveniles lacking algal endosymbionts, and further increases, up to 76%, were recorded when juveniles were subjected to thermal stress. We uncovered coral orthologues of two algal genes recently identified in DMSP biosynthesis, strongly indicating that corals possess the enzymatic machinery necessary for DMSP production. Our results overturn the paradigm that photosynthetic organisms are the sole biological source of DMSP, and highlight the double jeopardy represented by worldwide declining coral cover, as the potential to alleviate thermal stress through coral-produced DMSP declines correspondingly.}, }
@article {pmid24152321, year = {2014}, author = {Martinez, AJ and Weldon, SR and Oliver, KM}, title = {Effects of parasitism on aphid nutritional and protective symbioses.}, journal = {Molecular ecology}, volume = {23}, number = {6}, pages = {1594-1607}, doi = {10.1111/mec.12550}, pmid = {24152321}, issn = {1365-294X}, mesh = {Animals ; Aphids/genetics/*microbiology/*parasitology/physiology ; Bacterial Toxins/genetics ; Bacteriophages/physiology ; Buchnera/*physiology ; Enterobacteriaceae/*physiology/virology ; Genes, Bacterial ; Genotype ; Molecular Sequence Data ; *Symbiosis ; *Wasps ; }, abstract = {Insects often carry heritable symbionts that negotiate interactions with food plants or natural enemies. All pea aphids, Acyrthosiphon pisum, require infection with the nutritional symbiont Buchnera, and many are also infected with Hamiltonella, which protects against the parasitoid Aphidius ervi. Hamiltonella-based protection requires bacteriophages called APSEs with protection levels varying by strain and associated APSE. Endoparasitoids, including A. ervi, may benefit from protecting the nutritional symbiosis and suppressing the protective one, while the aphid and its heritable symbionts have aligned interests when attacked by the wasp. We investigated the effects of parasitism on the abundance of aphid nutritional and protective symbionts. First, we determined strength of protection associated with multiple symbiont strains and aphid genotypes as these likely impact symbiont responses. Unexpectedly, some A. pisum genotypes cured of facultative symbionts were resistant to parasitism and resistant aphid lines carried Hamiltonella strains that conferred no additional protection. Susceptible aphid clones carried protective strains. qPCR estimates show that parasitism significantly influenced both Buchnera and Hamiltonella titres, with multiple factors contributing to variation. In susceptible lines, parasitism led to increases in Buchnera near the time of larval wasp emergence consistent with parasite manipulation, but effects were variable in resistant lines. Parasitism also resulted in increases in APSE and subsequent decreases in Hamiltonella, and we discuss how this response may relate to the protective phenotype. In summary, we show that parasitism alters the within-host ecology of both nutritional and protective symbioses with effects likely significant for all players in this antagonistic interaction.}, }
@article {pmid24147756, year = {2013}, author = {Kay, CJ and Lawler, K and Kerr, ID}, title = {Analysis of the Sam50 translocase of excavate organisms supports evolution of divergent organelles from a common endosymbiotic event.}, journal = {Bioscience reports}, volume = {33}, number = {6}, pages = {}, pmid = {24147756}, issn = {1573-4935}, support = {BB/F016956/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Evolution, Molecular ; Mitochondria/*genetics/metabolism ; Mitochondrial Membrane Transport Proteins/*genetics/metabolism ; Phylogeny ; Protein Multimerization ; Protein Transport ; Protozoan Proteins/*genetics/metabolism ; Symbiosis/genetics ; Trichomonas vaginalis/*genetics/metabolism ; }, abstract = {As free-living organisms the ancestors of mitochondria and plastids encoded complete genomes, proteomes and metabolomes. As these symbionts became organelles all these aspects were reduced - genomes have degenerated with the host nucleus now encoding the most of the remaining endosymbiont proteome, while the metabolic processes of the symbiont have been streamlined to the functions of the emerging organelle. By contrast, the topology of the endosymbiont membrane has been preserved, necessitating the development of complex pathways for membrane insertion and translocation. In this study, we examine the characteristics of the endosymbiont-derived β-barrel insertase Sam501 in the excavate super-group. A candidate is further characterized in Trichomonas vaginalis, an unusual eukaryote possessing degenerate hydrogen-producing mitochondria called hydrogenosomes. This information supports a mitochondriate eukaryotic common ancestor with a similarly evolved β-barrel insertase, which has continued to be conserved in degenerate mitochondria.}, }
@article {pmid24147738, year = {2014}, author = {Scharff, LB and Bock, R}, title = {Synthetic biology in plastids.}, journal = {The Plant journal : for cell and molecular biology}, volume = {78}, number = {5}, pages = {783-798}, doi = {10.1111/tpj.12356}, pmid = {24147738}, issn = {1365-313X}, mesh = {Chloroplasts/genetics/metabolism ; Genetic Engineering ; Genomics/methods ; Molecular Sequence Data ; Plants, Genetically Modified/genetics/metabolism ; Plastids/genetics/*metabolism ; Synthetic Biology/*methods ; }, abstract = {Plastids (chloroplasts) harbor a small gene-dense genome that is amenable to genetic manipulation by transformation. During 1 billion years of evolution from the cyanobacterial endosymbiont to present-day chloroplasts, the plastid genome has undergone a dramatic size reduction, mainly as a result of gene losses and the large-scale transfer of genes to the nuclear genome. Thus the plastid genome can be regarded as a naturally evolved miniature genome, the gradual size reduction and compaction of which has provided a blueprint for the design of minimum genomes. Furthermore, because of the largely prokaryotic genome structure and gene expression machinery, the high transgene expression levels attainable in transgenic chloroplasts and the very low production costs in plant systems, the chloroplast lends itself to synthetic biology applications that are directed towards the efficient synthesis of green chemicals, biopharmaceuticals and other metabolites of commercial interest. This review describes recent progress with the engineering of plastid genomes with large constructs of foreign or synthetic DNA, and highlights the potential of the chloroplast as a model system in bottom-up and top-down synthetic biology approaches.}, }
@article {pmid24146831, year = {2013}, author = {Han, AW and Sandy, M and Fishman, B and Trindade-Silva, AE and Soares, CA and Distel, DL and Butler, A and Haygood, MG}, title = {Turnerbactin, a novel triscatecholate siderophore from the shipworm endosymbiont Teredinibacter turnerae T7901.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e76151}, pmid = {24146831}, issn = {1932-6203}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; 1U01TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/*genetics/metabolism ; Benzoates/chemistry/metabolism ; Bivalvia/metabolism/*microbiology ; Catechols/chemistry/isolation &amp; purification/*metabolism ; Gammaproteobacteria/*genetics/metabolism ; Gene Expression ; *Genome, Bacterial ; Gills/metabolism/microbiology ; Hydroxybenzoates/chemistry/isolation &amp; purification ; Iron/*metabolism ; Metabolic Networks and Pathways ; Multigene Family ; Mutation ; Nitrogen Fixation/physiology ; Oligopeptides/*biosynthesis/chemistry/isolation &amp; purification ; Peptide Synthases/genetics/metabolism ; Siderophores/*biosynthesis/chemistry/isolation &amp; purification ; Symbiosis ; }, abstract = {Shipworms are marine bivalve mollusks (Family Teredinidae) that use wood for shelter and food. They harbor a group of closely related, yet phylogenetically distinct, bacterial endosymbionts in bacteriocytes located in the gills. This endosymbiotic community is believed to support the host's nutrition in multiple ways, through the production of cellulolytic enzymes and the fixation of nitrogen. The genome of the shipworm endosymbiont Teredinibacter turnerae T7901 was recently sequenced and in addition to the potential for cellulolytic enzymes and diazotrophy, the genome also revealed a rich potential for secondary metabolites. With nine distinct biosynthetic gene clusters, nearly 7% of the genome is dedicated to secondary metabolites. Bioinformatic analyses predict that one of the gene clusters is responsible for the production of a catecholate siderophore. Here we describe this gene cluster in detail and present the siderophore product from this cluster. Genes similar to the entCEBA genes of enterobactin biosynthesis involved in the production and activation of dihydroxybenzoic acid (DHB) are present in this cluster, as well as a two-module non-ribosomal peptide synthetase (NRPS). A novel triscatecholate siderophore, turnerbactin, was isolated from the supernatant of iron-limited T. turnerae T7901 cultures. Turnerbactin is a trimer of N-(2,3-DHB)-L-Orn-L-Ser with the three monomeric units linked by Ser ester linkages. A monomer, dimer, dehydrated dimer, and dehydrated trimer of 2,3-DHB-L-Orn-L-Ser were also found in the supernatant. A link between the gene cluster and siderophore product was made by constructing a NRPS mutant, TtAH03. Siderophores could not be detected in cultures of TtAH03 by HPLC analysis and Fe-binding activity of culture supernatant was significantly reduced. Regulation of the pathway by iron is supported by identification of putative Fur box sequences and observation of increased Fe-binding activity under iron restriction. Evidence of a turnerbactin fragment was found in shipworm extracts, suggesting the production of turnerbactin in the symbiosis.}, }
@article {pmid24146634, year = {2013}, author = {Robinson, KM and Sieber, KB and Dunning Hotopp, JC}, title = {A review of bacteria-animal lateral gene transfer may inform our understanding of diseases like cancer.}, journal = {PLoS genetics}, volume = {9}, number = {10}, pages = {e1003877}, pmid = {24146634}, issn = {1553-7404}, support = {DP2 OD007372/OD/NIH HHS/United States ; 1-DP2-OD007372/OD/NIH HHS/United States ; }, mesh = {Animals ; Chromosomes/genetics/microbiology ; DNA, Bacterial/*genetics ; Gene Transfer, Horizontal/*genetics ; Humans ; Interspersed Repetitive Sequences ; Neoplasms/*genetics/microbiology/virology ; Phylogeny ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Lateral gene transfer (LGT) from bacteria to animals occurs more frequently than was appreciated prior to the advent of genome sequencing. In 2007, LGT from bacterial Wolbachia endosymbionts was detected in ~33% of the sequenced arthropod genomes using a bioinformatic approach. Today, Wolbachia/host LGT is thought to be widespread and many other cases of bacteria-animal LGT have been described. In insects, LGT may be more frequently associated with endosymbionts that colonize germ cells and germ stem cells, like Wolbachia endosymbionts. We speculate that LGT may occur from bacteria to a wide variety of eukaryotes, but only becomes vertically inherited when it occurs in germ cells. As such, LGT may happen routinely in somatic cells but never become inherited or fixed in the population. Lack of inheritance of such mutations greatly decreases our ability to detect them. In this review, we propose that such noninherited bacterial DNA integration into chromosomes in human somatic cells could induce mutations leading to cancer or autoimmune diseases in a manner analogous to mobile elements and viral integrations.}, }
@article {pmid24143175, year = {2013}, author = {Cayetano, L and Vorburger, C}, title = {Effects of heat shock on resistance to parasitoids and on life history traits in an aphid/endosymbiont system.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e75966}, pmid = {24143175}, issn = {1932-6203}, mesh = {Animals ; Aphids/genetics/growth &amp; development/*parasitology/*physiology ; Genotype ; *Heat-Shock Response ; Host-Parasite Interactions ; *Life Cycle Stages ; Reproduction ; *Symbiosis ; }, abstract = {Temperature variation is an important factor determining the outcomes of interspecific interactions, including those involving hosts and parasites. This can apply to variation in average temperature or to relatively short but intense bouts of extreme temperature. We investigated the effect of heat shock on the ability of aphids (Aphis fabae) harbouring protective facultative endosymbionts (Hamiltonella defensa) to resist parasitism by Hymenopteran parasitoids (Lysiphlebus fabarum). Furthermore, we investigated whether heat shocks can modify previously observed genotype-by-genotype (G x G) interactions between different endosymbiont isolates and parasitoid genotypes. Lines of genetically identical aphids possessing different isolates of H. defensa were exposed to one of two heat shock regimes (35°C and 39°C) or to a control temperature (20°C) before exposure to three different asexual lines of the parasitoids. We observed strong G x G interactions on parasitism rates, reflecting the known genetic specificity of symbiont-conferred resistance, and we observed a significant G x G x E interaction induced by heat shocks. However, this three-way interaction was mainly driven by the more extreme heat shock (39°C), which had devastating effects on aphid lifespan and reproduction. Restricting the analysis to the more realistic heat shock of 35°C, the G x G x E interaction was weaker (albeit still significant), and it did not lead to any reversals of the aphid lines' susceptibility rankings to different parasitoids. Thus, under conditions feasibly encountered in the field, the relative fitness of different parasitoid genotypes on hosts protected by particular symbiont strains remains mostly uncomplicated by heat stress, which should simplify biological control programs dealing with this system.}, }
@article {pmid24139901, year = {2013}, author = {Qiu, H and Price, DC and Weber, AP and Facchinelli, F and Yoon, HS and Bhattacharya, D}, title = {Assessing the bacterial contribution to the plastid proteome.}, journal = {Trends in plant science}, volume = {18}, number = {12}, pages = {680-687}, doi = {10.1016/j.tplants.2013.09.007}, pmid = {24139901}, issn = {1878-4372}, mesh = {Biological Evolution ; Chlorophyta/*metabolism ; Cyanobacteria/*metabolism ; Evolution, Molecular ; Gene Transfer, Horizontal ; Photosynthesis ; Phylogeny ; Plastids/metabolism ; *Proteome ; Symbiosis ; }, abstract = {Plastids fulfill a variety of different functions (e.g., photosynthesis and amino acid biosynthesis) that rely on proteins of cyanobacterial (i.e., endosymbiont), noncyanobacterial, and 'host' (eukaryotic) origins. Analysis of plastid proteome data from glaucophytes and green algae allows robust inference of protein origins and organelle protein sharing across the >1 billion years of Archaeplastida evolution. Here, we show that more than one-third of genes encoding plastid proteins lack detectable homologs in Cyanobacteria, underlining the taxonomically broad contributions to plastid functions. Chlamydiae and Proteobacteria are the most significant other bacterial sources of plastid proteins. Mapping of plastid proteins to metabolic pathways shows a core set of anciently derived proteins in Archaeplastida, with many others being lineage specific and derived from independent horizontal gene transfer (HGT) events.}, }
@article {pmid24137737, year = {2013}, author = {Voolstra, CR}, title = {A journey into the wild of the cnidarian model system Aiptasia and its symbionts.}, journal = {Molecular ecology}, volume = {22}, number = {17}, pages = {4366-4368}, doi = {10.1111/mec.12464}, pmid = {24137737}, issn = {1365-294X}, mesh = {Animals ; Dinoflagellida/*genetics ; *Genetics, Population ; Sea Anemones/*genetics ; *Symbiosis ; }, abstract = {The existence of coral reef ecosystems relies critically on the mutualistic relationship between calcifying cnidarians and photosynthetic, dinoflagellate endosymbionts in the genus Symbiodinium. Reef-corals have declined globally due to anthropogenic stressors, for example, rising sea-surface temperatures and pollution that often disrupt these symbiotic relationships (known as coral bleaching), exacerbating mass mortality and the spread of disease. This threatens one of the most biodiverse marine ecosystems providing habitats to millions of species and supporting an estimated 500 million people globally (Hoegh-Guldberg et al. 2007). Our understanding of cnidarian–dinoflagellate symbioses has improved notably with the recent application of genomic and transcriptomic tools (e.g. Voolstra et al. 2009; Bayer et al. 2012; Davy et al. 2012), but a model system that allows for easy manipulation in a laboratory environment is needed to decipher underlying cellular mechanisms important to the functioning of these symbioses. To this end, the sea anemone Aiptasia, otherwise known as a ‘pest’ to aquarium hobbyists, is emerging as such a model system (Schoenberg &amp; Trench 1980; Sunagawa et al. 2009; Lehnert et al. 2012). Aiptasia is easy to grow in culture and, in contrast to its stony relatives, can be maintained aposymbiotically (i.e. dinoflagellate free) with regular feeding. However, we lack basic information on the natural distribution and genetic diversity of these anemones and their endosymbiotic dinoflagellates. These data are essential for placing the significance of this model system into an ecological context. In this issue of Molecular Ecology, Thornhill et al. (2013) are the first to present genetic evidence on the global distribution, diversity and population structure of Aiptasia and its associated Symbiodinium spp. By integrating analyses of the host and symbiont, this research concludes that the current Aitpasia taxonomy probably needs revision and that two distinct Aiptasia lineages are prevalent that have probably been spread through human activity. One lineage engages in a specific symbiosis with Symbiodinium minutum throughout the tropics, whereas a second, local Aiptasia sp. population in Florida appears more flexible in partnering with more than one symbiont. The existence of symbiont-specific and symbiont-flexible Aiptasia lineages can greatly complement laboratory-based experiments looking into mechanisms of symbiont selectivity. In a broader context, the study by Thornhill et al. (2013) should inspire more studies to target the natural environment of model systems in a global context targeting all participating member species when establishing ecological and genetic baselines.}, }
@article {pmid24134732, year = {2014}, author = {Thornhill, DJ and Lewis, AM and Wham, DC and LaJeunesse, TC}, title = {Host-specialist lineages dominate the adaptive radiation of reef coral endosymbionts.}, journal = {Evolution; international journal of organic evolution}, volume = {68}, number = {2}, pages = {352-367}, doi = {10.1111/evo.12270}, pmid = {24134732}, issn = {1558-5646}, mesh = {Adaptation, Physiological/*genetics ; *Coral Reefs ; DNA, Protozoan/genetics ; DNA, Ribosomal/genetics ; Dinoflagellida/*genetics/physiology ; *Genetic Speciation ; Host Specificity ; Microsatellite Repeats ; *Symbiosis ; }, abstract = {Bursts in species diversification are well documented among animals and plants, yet few studies have assessed recent adaptive radiations of eukaryotic microbes. Consequently, we examined the radiation of the most ecologically dominant group of endosymbiotic dinoflagellates found in reef-building corals, Symbiodinium Clade C, using nuclear ribosomal (ITS2), chloroplast (psbA(ncr)), and multilocus microsatellite genotyping. Through a hierarchical analysis of high-resolution genetic data, we assessed whether ecologically distinct Symbiodinium, differentiated by seemingly equivocal rDNA sequence differences, are independent species lineages. We also considered the role of host specificity in Symbiodinium speciation and the correspondence between endosymbiont diversification and Caribbean paleo-history. According to phylogenetic, biological, and ecological species concepts, Symbiodinium Clade C comprises many distinct species. Although regional factors contributed to population-genetic structuring of these lineages, Symbiodinium diversification was mainly driven by host specialization. By combining patterns of the endosymbiont's host specificity, water depth distribution, and phylogeography with paleo-historical signals of climate change, we inferred that present-day species diversity on Atlantic coral reefs stemmed mostly from a post-Miocene adaptive radiation. Host-generalist progenitors spread, specialized, and diversified during the ensuing epochs of prolonged global cooling and change in reef-faunal assemblages. Our evolutionary reconstruction thus suggests that Symbiodinium undergoes "boom and bust" phases in diversification and extinction during major climate shifts.}, }
@article {pmid24126104, year = {2013}, author = {Facchinelli, F and Colleoni, C and Ball, SG and Weber, AP}, title = {Chlamydia, cyanobiont, or host: who was on top in the ménage à trois?.}, journal = {Trends in plant science}, volume = {18}, number = {12}, pages = {673-679}, doi = {10.1016/j.tplants.2013.09.006}, pmid = {24126104}, issn = {1878-4372}, mesh = {Chlamydia/*genetics/metabolism ; Cyanobacteria/genetics/*metabolism ; Glaucophyta/genetics/metabolism/microbiology ; Glycogen/metabolism ; Plastids/genetics/metabolism ; Rhodophyta/*genetics/metabolism/microbiology ; Symbiosis ; }, abstract = {The endosymbiont hypothesis proposes that photosynthate from the cyanobiont was exported to the cytosol of the eukaryote host and polymerized from ADP-glucose into glycogen. Chlamydia-like pathogens are the second major source of foreign genes in Archaeplastida, suggesting that these obligate intracellular pathogens had a significant role during the establishment of endosymbiosis, likely through facilitating the metabolic integration between the endosymbiont and the eukaryotic host. In this opinion article, we propose that a hexose phosphate transporter of chlamydial origin was the first transporter responsible for exporting photosynthate out of the cyanobiont. This connection pre-dates the recruitment of the host-derived carbon translocators on the plastid inner membranes of green and red algae, land plants, and photosynthetic organisms of higher order endosymbiotic origin.}, }
@article {pmid24125079, year = {2013}, author = {Segoli, M and Stouthamer, R and Stouthamer, CM and Rugman-Jones, P and Rosenheim, JA}, title = {The effect of Wolbachia on the lifetime reproductive success of its insect host in the field.}, journal = {Journal of evolutionary biology}, volume = {26}, number = {12}, pages = {2716-2720}, doi = {10.1111/jeb.12264}, pmid = {24125079}, issn = {1420-9101}, mesh = {Animals ; Insecta/*microbiology/physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia is a widespread endosymbiont that induces dramatic manipulations of its host's reproduction. Although there has been substantial progress in the developing theory for Wolbachia-host interactions and in measuring the effects of Wolbachia on host fitness in the laboratory, there is a widely recognized need to quantify the effects of Wolbachia on the host fitness in the field. The wasp Anagrus sophiae, an egg parasitoid of planthoppers, carries a Wolbachia strain that induces parthenogenesis, but its effects on the fitness of its Anagrus host are unknown. We developed a method to estimate the realized lifetime reproductive success of female wasps by collecting them soon after they die naturally in the field, counting the number of eggs remaining in their ovaries and quantifying Wolbachia density in their body. We sampled from a highly infected A. sophiae population and found no evidence for Wolbachia virulence and possible evidence for positive effects of Wolbachia on realized reproductive success.}, }
@article {pmid24124002, year = {2014}, author = {Elnagdy, S and Messing, S and Majerus, ME}, title = {The Japanese ladybirds, Coccinula crotchi and Coccinula sinensis, are infected with very closely related strains of male-killing Flavobacterium.}, journal = {Insect science}, volume = {21}, number = {6}, pages = {699-706}, doi = {10.1111/1744-7917.12062}, pmid = {24124002}, issn = {1744-7917}, mesh = {Animals ; Coleoptera/*microbiology/physiology ; DNA, Bacterial/genetics ; Environment ; Female ; Flavobacterium/*classification/*genetics/physiology ; Japan ; Male ; Phylogeny ; Sex Ratio ; Tetracycline/pharmacology ; }, abstract = {Male-killing is 1 of 4 known strategies that inherited parasitic endosymbionts have evolved to manipulate their host's reproduction. In early male-killing, infected male offspring are killed early in embryogenesis. Within the Insecta, male-killing bacteria have been found in a wide range of hosts. The Coccinellidae families of beetles, better known as ladybirds, are particularly prone to male-killer invasion. In samples of the coccinellid, Coccinula crotchi, from Japan, a new male-killing bacterium was revealed by phenotypic assay. Molecular genetic analysis revealed the identity to be a tetracycline-sensitive Flavobacterium that causes female-biased offspring sex ratio. Furthermore, that Flavobacterium strain was found to be closely related to the Flavobacterium causing male-killing in the congeneric Japanese coccinellid, Coccinula sinensis, which was collected from the same region. However, we found slightly different Flavobacterium strains infecting C. sinensis from regions with different environmental conditions. This may be an indication of horizontal transmission of male-killing Flavobacterium between these 2 ladybird spices. Finally, environmental conditions may affect the spread of male-killing bacteria among their hosts.}, }
@article {pmid24121800, year = {2014}, author = {Ventura, IM and Costa, T and Klaczko, LB}, title = {Low temperature reveals genetic variability against male-killing Spiroplasma in Drosophila melanogaster natural populations.}, journal = {Microbial ecology}, volume = {67}, number = {1}, pages = {229-235}, pmid = {24121800}, issn = {1432-184X}, mesh = {Animals ; Drosophila melanogaster/*microbiology/physiology ; Female ; Genetic Variation ; Male ; Phenotype ; Population Dynamics ; Sex Ratio ; Spiroplasma/*genetics ; Symbiosis ; *Temperature ; }, abstract = {Spiroplasma endosymbionts are maternally inherited microorganisms which infect many arthropod species. In some Drosophila species, it acts as a reproductive manipulator, spreading in populations by killing the sons of infected mothers. Distinct Drosophila melanogaster populations from Brazil exhibit variable male-killing Spiroplasma prevalences. In this study, we investigated the presence of variability for the male-killing phenotype among Drosophila and/or Spiroplasma strains and verified if it correlates with the endosymbiont prevalence in natural populations. For that, we analyzed the male-killing expression when Spiroplasma strains from different populations were transferred to a standard D. melanogaster line (Canton-S) and when a common Spiroplasma strain was transferred to different wild-caught D. melanogaster lines, both at optimal and challenging temperatures for the bacteria. No variation was observed in the male-killing phenotype induced by different Spiroplasma strains. No phenotypic variability among fly lines was detected at optimal temperature (23 °C), as well. Conversely, significant variation in the male-killing expression was revealed among D. melanogaster lines at 18.5 °C, probably caused by imperfect transmission of the endosymbiont. Distinct lines differed in their average sex ratios as well as in the pattern of male-killing expression as the infected females aged. Greater variation occurred among lines from one locality, although there was no clear correlation between the male-killing intensity and the endosymbiont prevalence in each population. Imperfect transmission or male killing may also occur in the field, thus helping to explain the low or intermediate prevalences reported in nature. We discuss the implications of our results for the dynamics of male-killing Spiroplasma in natural populations.}, }
@article {pmid24118435, year = {2013}, author = {Gerth, M and Röthe, J and Bleidorn, C}, title = {Tracing horizontal Wolbachia movements among bees (Anthophila): a combined approach using multilocus sequence typing data and host phylogeny.}, journal = {Molecular ecology}, volume = {22}, number = {24}, pages = {6149-6162}, doi = {10.1111/mec.12549}, pmid = {24118435}, issn = {1365-294X}, mesh = {Animals ; Bayes Theorem ; Bees/genetics/*microbiology ; *Biological Evolution ; *Gene Transfer, Horizontal ; Models, Genetic ; Molecular Sequence Data ; Multilocus Sequence Typing ; *Phylogeny ; Symbiosis/genetics ; Wolbachia/classification/*genetics ; }, abstract = {The endosymbiotic bacterium Wolbachia enhances its spread via vertical transmission by generating reproductive effects in its hosts, most notably cytoplasmic incompatibility (CI). Additionally, frequent interspecific horizontal transfer is evident from a lack of phylogenetic congruence between Wolbachia and its hosts. The mechanisms of this lateral transfer are largely unclear. To identify potential pathways of Wolbachia movements, we performed multilocus sequence typing of Wolbachia strains from bees (Anthophila). Using a host phylogeny and ecological data, we tested various models of horizontal endosymbiont transmission. In general, Wolbachia strains seem to be randomly distributed among bee hosts. Kleptoparasite-host associations among bees as well as other ecological links could not be supported as sole basis for the spread of Wolbachia. However, cophylogenetic analyses and divergence time estimations suggest that Wolbachia may persist within a host lineage over considerable timescales and that strictly vertical transmission and subsequent random loss of infections across lineages may have had a greater impact on Wolbachia strain distribution than previously estimated. Although general conclusions about Wolbachia movements among arthropod hosts cannot be made, we present a framework by which precise assumptions about shared evolutionary histories of Wolbachia and a host taxon can be modelled and tested.}, }
@article {pmid24118386, year = {2013}, author = {Łukasik, P and Guo, H and van Asch, M and Ferrari, J and Godfray, HC}, title = {Protection against a fungal pathogen conferred by the aphid facultative endosymbionts Rickettsia and Spiroplasma is expressed in multiple host genotypes and species and is not influenced by co-infection with another symbiont.}, journal = {Journal of evolutionary biology}, volume = {26}, number = {12}, pages = {2654-2661}, doi = {10.1111/jeb.12260}, pmid = {24118386}, issn = {1420-9101}, support = {BB/E010857/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/genetics/*microbiology ; Fungi/*pathogenicity ; Genotype ; *Host-Pathogen Interactions ; Rickettsia/*pathogenicity ; Spiroplasma/*pathogenicity ; *Symbiosis ; }, abstract = {Many insects harbour facultative endosymbiotic bacteria, often more than one type at a time. These symbionts can have major effects on their hosts' biology, which may be modulated by the presence of other symbiont species and by the host's genetic background. We investigated these effects by transferring two sets of facultative endosymbionts (one Hamiltonella and Rickettsia, the other Hamiltonella and Spiroplasma) from naturally double-infected pea aphid hosts into five novel host genotypes of two aphid species. The symbionts were transferred either together or separately. We then measured aphid fecundity and susceptibility to an entomopathogenic fungus. The pathogen-protective phenotype conferred by the symbionts Rickettsia and Spiroplasma varied among host genotypes, but was not influenced by co-infection with Hamiltonella. Fecundity varied across single and double infections and between symbiont types, aphid genotypes and species. Some host genotypes benefit from harbouring more than one symbiont type.}, }
@article {pmid24118111, year = {2013}, author = {Early, AM and Clark, AG}, title = {Monophyly of Wolbachia pipientis genomes within Drosophila melanogaster: geographic structuring, titre variation and host effects across five populations.}, journal = {Molecular ecology}, volume = {22}, number = {23}, pages = {5765-5778}, pmid = {24118111}, issn = {1365-294X}, support = {R01 AI064950/AI/NIAID NIH HHS/United States ; R01AI064950/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bayes Theorem ; DNA, Mitochondrial/genetics ; Drosophila melanogaster/genetics/*microbiology ; *Evolution, Molecular ; Genetics, Population ; *Genome, Bacterial ; Haplotypes ; Phenotype ; Phylogeny ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Wolbachia pipientis is one of the most widely studied endosymbionts today, yet we know little about its short-term adaptation and evolution. Here, using a set of 91 inbred Drosophila melanogaster lines from five populations, we explore patterns of diversity and recent evolution in the Wolbachia strain wMel. Within the D. melanogaster lines, we identify six major mitochondrial clades and four wMel clades. Concordant with past studies, the Wolbachia haplotypes contain an overall low level of nucleotide diversity, yet they still display geographic structuring. Using Bayesian analysis informed with demographic estimates of colonization times, we estimate that all extant D. melanogaster mitochondrial haplotypes coalesce to a Wolbachia-infected ancestor approximately 2200 years ago. Finally, we measure wMel titre within the infected flies and find that titre varies across populations, an effect attributable to host genetic factors. This demonstration of local phenotypic divergence suggests that intraspecific host genetic variation plays a key role in shaping this model symbiotic system.}, }
@article {pmid24100000, year = {2013}, author = {Michalik, A and Gołas, A and Kot, M and Wieczorek, K and Szklarzewicz, T}, title = {Endosymbiotic microorganisms in Adelges (Sacchiphantes) viridis (Insecta, Hemiptera, Adelgoidea: Adelgidae): Molecular characterization, ultrastructure and transovarial transmission.}, journal = {Arthropod structure &amp; development}, volume = {42}, number = {6}, pages = {531-538}, doi = {10.1016/j.asd.2013.09.004}, pmid = {24100000}, issn = {1873-5495}, mesh = {Animals ; Aphids/classification/*microbiology/ultrastructure ; Betaproteobacteria/*classification/genetics/isolation &amp; purification ; Female ; Microscopy, Electron, Transmission ; Oocytes/microbiology/ultrastructure ; *Symbiosis ; }, abstract = {The aim of this paper was to identify endosymbiotic microorganisms living in the body cavity of a Polish population of an aphid, Adelges (Sacchiphantes) viridis, as well as to describe their ultrastructure and mode of transmission between generations. Molecular data (amplification and sequencing of 16S rRNA genes) indicated that endosymbionts of A. (S.) viridis are Betaproteobacteria of the species "Candidatus Vallotia virida". Endosymbiotic bacteria are rod-shaped and localized in the cytoplasm of specific cells, termed bacteriocytes, of host insects. Endosymbionts sharing the same bacteriocytes differ in the density of their cytoplasm. There are two morphotypes of endosymbiotic bacteria: with electron-dense cytoplasm and electron-translucent cytoplasm. Since only bacteria containing electron-dense cytoplasm were observed in the binary fusion stage, differences in density of the cytoplasm are probably due to changes in the cytoskeleton of bacteria during division. Endosymbionts of A. (S.) viridis are transovarially (i.e. via oocytes) transmitted from the mother to the offspring.}, }
@article {pmid24098632, year = {2013}, author = {Ruff, SE and Arnds, J and Knittel, K and Amann, R and Wegener, G and Ramette, A and Boetius, A}, title = {Microbial communities of deep-sea methane seeps at Hikurangi continental margin (New Zealand).}, journal = {PloS one}, volume = {8}, number = {9}, pages = {e72627}, pmid = {24098632}, issn = {1932-6203}, mesh = {Analysis of Variance ; Animals ; Archaea/genetics/*metabolism/ultrastructure ; Base Sequence ; Cluster Analysis ; DNA, Ribosomal Spacer/genetics ; Deltaproteobacteria/genetics/metabolism ; *Ecosystem ; Fluorescence ; Gammaproteobacteria/classification/genetics/*metabolism ; Gene Library ; Geologic Sediments/chemistry/*microbiology ; In Situ Hybridization, Fluorescence ; Methane/*metabolism ; Microbiota/genetics/*physiology ; Molecular Sequence Data ; New Zealand ; Pacific Ocean ; Phylogeny ; Polychaeta/*physiology ; Sequence Analysis, DNA ; }, abstract = {The methane-emitting cold seeps of Hikurangi margin (New Zealand) are among the few deep-sea chemosynthetic ecosystems of the Southern Hemisphere known to date. Here we compared the biogeochemistry and microbial communities of a variety of Hikurangi cold seep ecosystems. These included highly reduced seep habitats dominated by bacterial mats, partially oxidized habitats populated by heterotrophic ampharetid polychaetes and deeply oxidized habitats dominated by chemosynthetic frenulate tubeworms. The ampharetid habitats were characterized by a thick oxic sediment layer that hosted a diverse and biomass-rich community of aerobic methanotrophic Gammaproteobacteria. These bacteria consumed up to 25% of the emanating methane and clustered within three deep-branching groups named Marine Methylotrophic Group (MMG) 1-3. MMG1 and MMG2 methylotrophs belong to the order Methylococcales, whereas MMG3 methylotrophs are related to the Methylophaga. Organisms of the groups MMG1 and MMG3 are close relatives of chemosynthetic endosymbionts of marine invertebrates. The anoxic sediment layers of all investigated seeps were dominated by anaerobic methanotrophic archaea (ANME) of the ANME-2 clade and sulfate-reducing Deltaproteobacteria. Microbial community analysis using Automated Ribosomal Intergenic Spacer Analysis (ARISA) showed that the different seep habitats hosted distinct microbial communities, which were strongly influenced by the seep-associated fauna and the geographic location. Despite outstanding features of Hikurangi seep communities, the organisms responsible for key ecosystem functions were similar to those found at seeps worldwide. This suggests that similar types of biogeochemical settings select for similar community composition regardless of geographic distance. Because ampharetid polychaetes are widespread at cold seeps the role of aerobic methanotrophy may have been underestimated in seafloor methane budgets.}, }
@article {pmid24098592, year = {2013}, author = {Akhouayri, IG and Habtewold, T and Christophides, GK}, title = {Melanotic pathology and vertical transmission of the gut commensal Elizabethkingia meningoseptica in the major malaria vector Anopheles gambiae.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e77619}, pmid = {24098592}, issn = {1932-6203}, support = {//Wellcome Trust/United Kingdom ; 093587/Z/10/Z/WT_/Wellcome Trust/United Kingdom ; S19551/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Anopheles/*microbiology/parasitology ; Fat Body/microbiology/parasitology ; Female ; Flavobacteriaceae/*pathogenicity/physiology ; Gastrointestinal Tract/*microbiology/parasitology ; Hemolymph/microbiology/parasitology ; Host-Parasite Interactions ; Humans ; Infectious Disease Transmission, Vertical ; Insect Vectors/*microbiology/parasitology ; Larva/*microbiology/parasitology ; Malaria, Falciparum/parasitology/*transmission ; Melanins/metabolism ; Plasmodium falciparum/pathogenicity/physiology ; Symbiosis ; Zygote/microbiology/parasitology ; }, abstract = {BACKGROUND: The resident gut flora is known to have significant impacts on the life history of the host organism. Endosymbiotic bacterial species in the Anopheles mosquito gut are potent modulators of sexual development of the malaria parasite, Plasmodium, and thus proposed as potential control agents of malaria transmission.<br><br>RESULTS: Here we report a melanotic pathology in the major African malaria vector Anopheles gambiae, caused by the dominant mosquito endosymbiont Elizabethkingiameningoseptica. Transfer of melanised tissues into the haemolymph of healthy adult mosquitoes or direct haemolymph inoculation with isolated E. meningoseptica bacteria were the only means for transmission and de novo formation of melanotic lesions, specifically in the fat body tissues of recipient individuals. We show that E. meningoseptica can be vertically transmitted from eggs to larvae and that E. meningoseptica-mono-associated mosquitoes display significant mortality, which is further enhanced upon Plasmodium infection, suggesting a synergistic impact of E. meningoseptica and Plasmodium on mosquito survival.<br><br>CONCLUSION: The high pathogenicity and permanent association of E. meningoseptica with An. Gambiae through vertical transmission constitute attractive characteristics towards the potential design of novel mosquito/malaria biocontrol strategies.}, }
@article {pmid24098543, year = {2013}, author = {Giraud, I and Valette, V and Bech, N and Grandjean, F and Cordaux, R}, title = {Isolation and characterization of microsatellite loci for the isopod crustacean Armadillidium vulgare and transferability in terrestrial isopods.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e76639}, pmid = {24098543}, issn = {1932-6203}, mesh = {Animals ; Biological Evolution ; Female ; Feminization/*genetics/microbiology ; Genetic Loci ; Genetic Variation ; Genomic Library ; Isopoda/*genetics/microbiology ; Male ; *Microsatellite Repeats ; Phylogeny ; *Sex Determination Processes ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Armadillidium vulgare is a terrestrial isopod (Crustacea, Oniscidea) which harbors Wolbachia bacterial endosymbionts. A. vulgare is the major model for the study of Wolbachia-mediated feminization of genetic males in crustaceans. As a consequence of their impact on host sex determination mechanisms, Wolbachia endosymbionts are thought to significantly influence A. vulgare evolution on various grounds, including population genetic structure, diversity and reproduction strategies. To provide molecular tools for examining these questions, we isolated microsatellite loci through 454 pyrosequencing of a repeat-enriched A. vulgare genomic library. We selected 14 markers and developed three polymorphic microsatellite multiplex kits. We tested the kits on two A. vulgare natural populations and found high genetic variation, thereby making it possible to investigate the impact of Wolbachia endosymbionts on A. vulgare nuclear variation at unprecedented resolution. In addition, we tested the transferability of these kits by cross-species amplification in five other terrestrial isopod species harboring Wolbachia endosymbionts. The microsatellite loci showed good transferability in particular in Armadillidium nasatum and Chaetophiloscia elongata, for which these markers represent promising tools for future genetic studies.}, }
@article {pmid24098533, year = {2013}, author = {Donati, AJ and Lee, HI and Leveau, JH and Chang, WS}, title = {Effects of indole-3-acetic acid on the transcriptional activities and stress tolerance of Bradyrhizobium japonicum.}, journal = {PloS one}, volume = {8}, number = {10}, pages = {e76559}, pmid = {24098533}, issn = {1932-6203}, mesh = {Bacterial Proteins/*genetics/metabolism ; Biofilms/drug effects/growth &amp; development ; Bradyrhizobium/*drug effects/genetics/metabolism ; Gene Expression Profiling ; Gene Expression Regulation, Bacterial/*drug effects ; *Genome, Bacterial ; Indoleacetic Acids/*pharmacology ; Microbial Viability/drug effects ; Plant Growth Regulators/*pharmacology ; Polysaccharides, Bacterial/biosynthesis/genetics ; Soybeans/microbiology ; Stress, Physiological ; Symbiosis/physiology ; Transcription, Genetic/*drug effects ; }, abstract = {A genome-wide transcriptional profile of Bradyrhizobium japonicum, the nitrogen-fixing endosymbiont of the soybean plant, revealed differential expression of approximately 15% of the genome after a 1 mM treatment with the phytohormone indole-3-acetic acid (IAA). A total of 1,323 genes were differentially expressed (619 up-regulated and 704 down-regulated) at a two-fold cut off with q value ≤ 0.05. General stress response genes were induced, such as those involved in response to heat, cold, oxidative, osmotic, and desiccation stresses and in exopolysaccharide (EPS) biosynthesis. This suggests that IAA is effective in activating a generalized stress response in B. japonicum. The transcriptional data were corroborated by the finding that stress tolerance of B. japonicum in cell viability assays was enhanced when pre-treated with 1 mM IAA compared to controls. The IAA treatment also stimulated biofilm formation and EPS production by B. japonicum, especially acidic sugar components in the total EPS. The IAA pre-treatment did not influence the nodulation ability of B. japonicum. The data provide a comprehensive overview of the potential transcriptional responses of the symbiotic bacterium when exposed to the ubiquitous hormone of its plant host.}, }
@article {pmid24079981, year = {2014}, author = {Schäberle, TF and Schiefer, A and Schmitz, A and König, GM and Hoerauf, A and Pfarr, K}, title = {Corallopyronin A - a promising antibiotic for treatment of filariasis.}, journal = {International journal of medical microbiology : IJMM}, volume = {304}, number = {1}, pages = {72-78}, doi = {10.1016/j.ijmm.2013.08.010}, pmid = {24079981}, issn = {1618-0607}, mesh = {Animals ; Anti-Bacterial Agents/biosynthesis/isolation &amp; purification/*pharmacology/therapeutic use ; Filariasis/*drug therapy ; Filaricides/isolation &amp; purification/*pharmacology/therapeutic use ; Filarioidea/*microbiology/physiology ; Humans ; Lactones/isolation &amp; purification/*pharmacology/therapeutic use ; Symbiosis ; Wolbachia/*drug effects/physiology ; }, abstract = {Lymphatic filariasis and onchocerciasis are diseases of severe morbidity that affect the poorest of the poor in the world. The diseases are caused by filarial nematodes that are transmitted by mosquitoes or biting blackflies and are endemic to more than 80 countries worldwide, mainly in the tropics and sub-tropics. Current control programs aim to eliminate the diseases by distributing antifilarial drugs. However, the primary effect of the drugs is to kill the microfilariae in the blood or skin, thus preventing uptake by the obligate insect vector. Since the adult worms live 10 years or longer, drug distribution requires many years of treatment, which is a heavy burden on the burgeoning health care systems. Sub-optimal response, possible resistance and inadequate population coverage lessen the chances for successful elimination in all endemic areas. The search for new drugs that could enhance elimination by permanently sterilizing or killing adult worms has identified the Wolbachia intracellular bacteria of filarial nematodes as a target. Depleting the obligate endosymbionts from the worms with doxycycline or rifampicin causes a permanent block in oogenesis, embryogenesis and development, and in slow death of the adult worms. These two antibiotics are suitable for individual drug administration, but caveats exist for their inclusion in broader drug administration programs. Here we review Wolbachia as targets for antifilarial drug discovery and highlight the natural product corallopyronin A as an effective drug that is currently being developed specifically for use against filarial nematodes.}, }
@article {pmid24071059, year = {2013}, author = {Kambhampati, S and Alleman, A and Park, Y}, title = {Complete genome sequence of the endosymbiont Blattabacterium from the cockroach Nauphoeta cinerea (Blattodea: Blaberidae).}, journal = {Genomics}, volume = {102}, number = {5-6}, pages = {479-483}, doi = {10.1016/j.ygeno.2013.09.003}, pmid = {24071059}, issn = {1089-8646}, mesh = {Animals ; Bacterial Proteins/analysis ; Bacteroidetes/*classification/*genetics ; Cockroaches/*microbiology ; Genes, Bacterial ; *Genome, Bacterial ; Molecular Sequence Data ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {All cockroaches, with the exception of one cave-dwelling genus, harbor endosymbiotic bacteria, Blattabacterium. After much confusion concerning their function, recent genomic studies indicate that Blattabacterium synthesize amino acids, vitamins, and other compounds. However, the Blattabacterium genomes sequenced so far suggest that the endosymbionts are variable in their genome size, gene composition, and compounds they synthesize. Therefore, there is a need for sequencing additional Blattabacterium genomes to fully comprehend their evolution. Here, we report the complete genome sequence of Blattabacterium (BNCIN) harbored by the host Nauphoeta cinerea (Blaberidae). The BNCIN genome is 622,952 bp long and consists of 581 protein coding regions and 627 genes of putative function. The genome of BNCIN is comparable, with a few structural and functional differences, to the genomes of the other sequenced Blattabacterium. The endosymbiont is involved in complete or partial synthesis of 15 amino acids.}, }
@article {pmid24069026, year = {2013}, author = {Behmer, ST and Olszewski, N and Sebastiani, J and Palka, S and Sparacino, G and Sciarrno, E and Grebenok, RJ}, title = {Plant phloem sterol content: forms, putative functions, and implications for phloem-feeding insects.}, journal = {Frontiers in plant science}, volume = {4}, number = {}, pages = {370}, pmid = {24069026}, issn = {1664-462X}, abstract = {All eukaryotes contain sterols, which serve as structural components in cell membranes, and as precursors for important hormones. Plant vegetative tissues are known to contain mixtures of sterols, but very little is known about the sterol composition of phloem. Plants are food for many animals, but plant-feeding arthropods (including phloem-feeding insets) are unique among animals in that they have lost the ability to synthesize sterols, and must therefore acquire these essential nutrients from their food, or via endosymbionts. Our paper starts by providing a very brief overview of variation in plant sterol content, and how different sterols can affect insect herbivores, including those specializing on phloem. We then describe an experiment, where we bulk collected phloem sap exudate from bean and tobacco, and analyzed its sterol content. This approach revealed two significant observations concerning phloem sterols. First, the phloem exudate from each plant was found to contain sterols in three different fractions - free sterols, sterols conjugated to lipids (acylated), and sterols conjugated to carbohydrates (glycosylated). Second, for both plants, cholesterol was identified as the dominant sterol in each phloem exudate fraction; the remaining sterols in each fraction were a mixture of common phytosterols. We discuss our phloem exudate sterol profiles in a plant physiology/biochemistry context, and how it relates to the nutritional physiology/ecology of phloem-feeding insects. We close by proposing important next steps that will advance our knowledge concerning plant phloem sterol biology, and how phloem-sterol content might affect phloem-feeding insects.}, }
@article {pmid24065973, year = {2013}, author = {Qiu, H and Yoon, HS and Bhattacharya, D}, title = {Algal endosymbionts as vectors of horizontal gene transfer in photosynthetic eukaryotes.}, journal = {Frontiers in plant science}, volume = {4}, number = {}, pages = {366}, pmid = {24065973}, issn = {1664-462X}, abstract = {Photosynthesis in eukaryotes occurs in the plastid, an organelle that is derived from a single cyanobacterial primary endosymbiosis in the common ancestor of the supergroup Plantae (or Archaeplastida) that includes green, red, and glaucophyte algae and plants. However a variety of other phytoplankton such as the chlorophyll c-containing diatoms, dinoflagellates, and haptophytes contain a red alga-derived plastid that traces its origin to secondary or tertiary (eukaryote engulfs eukaryote) endosymbiosis. The hypothesis of Plantae monophyly has only recently been substantiated, however the extent and role of endosymbiotic and horizontal gene transfer (EGT and HGT) in algal genome evolution still remain to be fully understood. What is becoming clear from analysis of complete genome data is that algal gene complements can no longer be considered essentially eukaryotic in provenance; i.e., with the expected addition of several hundred cyanobacterial genes derived from EGT and a similar number derived from the mitochondrial ancestor. For example, we now know that foreign cells such as Chlamydiae and other prokaryotes have made significant contributions to plastid functions in Plantae. Perhaps more surprising is the recent finding of extensive bacterium-derived HGT in the nuclear genome of the unicellular red alga Porphyridium purpureum that does not relate to plastid functions. These non-endosymbiont gene transfers not only shaped the evolutionary history of Plantae but also were propagated via secondary endosymbiosis to a multitude of other phytoplankton. Here we discuss the idea that Plantae (in particular red algae) are one of the major players in eukaryote genome evolution by virtue of their ability to act as "sinks" and "sources" of foreign genes through HGT and endosymbiosis, respectively. This hypothesis recognizes the often under-appreciated Rhodophyta as major sources of genetic novelty among photosynthetic eukaryotes.}, }
@article {pmid24060132, year = {2013}, author = {Sloan, DB and Bennett, GM and Engel, P and Williams, D and Ochman, H}, title = {Disentangling associated genomes.}, journal = {Methods in enzymology}, volume = {531}, number = {}, pages = {445-464}, doi = {10.1016/B978-0-12-407863-5.00020-4}, pmid = {24060132}, issn = {1557-7988}, support = {F32 GM099334/GM/NIGMS NIH HHS/United States ; R01 GM074738/GM/NIGMS NIH HHS/United States ; GM101209/GM/NIGMS NIH HHS/United States ; 1F32GM099334/GM/NIGMS NIH HHS/United States ; R01 GM056120/GM/NIGMS NIH HHS/United States ; }, mesh = {Algorithms ; Bacteria/*genetics ; *Computational Biology ; *Genome, Bacterial ; Metagenomics/*methods ; }, abstract = {The recovery and assembly of genome sequences from samples containing communities of organisms pose several challenges. Because it is rarely possible to disassociate the resident organisms prior to sequencing, a major obstacle is the assignment of sequences to a single genome that can be fully assembled. This chapter delineates many of the decisions, methodologies, and approaches that can lead to the generation of complete or nearly complete microbial genome sequences from heterogeneous samples-that is, the procedures that allow us to turn metagenomes into genomes.}, }
@article {pmid24059868, year = {2013}, author = {Bongaerts, P and Frade, PR and Ogier, JJ and Hay, KB and van Bleijswijk, J and Englebert, N and Vermeij, MJ and Bak, RP and Visser, PM and Hoegh-Guldberg, O}, title = {Sharing the slope: depth partitioning of agariciid corals and associated Symbiodinium across shallow and mesophotic habitats (2-60 m) on a Caribbean reef.}, journal = {BMC evolutionary biology}, volume = {13}, number = {}, pages = {205}, pmid = {24059868}, issn = {1471-2148}, mesh = {Animals ; Anthozoa/genetics/*physiology ; Caribbean Region ; Coral Reefs ; Dinoflagellida/*classification/genetics/*physiology ; Ecosystem ; Environment ; Genetic Variation ; Phylogeny ; Symbiosis ; }, abstract = {BACKGROUND: Scleractinian corals and their algal endosymbionts (genus Symbiodinium) exhibit distinct bathymetric distributions on coral reefs. Yet, few studies have assessed the evolutionary context of these ecological distributions by exploring the genetic diversity of closely related coral species and their associated Symbiodinium over large depth ranges. Here we assess the distribution and genetic diversity of five agariciid coral species (Agaricia humilis, A. agaricites, A. lamarcki, A. grahamae, and Helioseris cucullata) and their algal endosymbionts (Symbiodinium) across a large depth gradient (2-60 m) covering shallow to mesophotic depths on a Caribbean reef.<br><br>RESULTS: The five agariciid species exhibited distinct depth distributions, and dominant Symbiodinium associations were found to be species-specific, with each of the agariciid species harbouring a distinct ITS2-DGGE profile (except for a shared profile between A. lamarcki and A. grahamae). Only A. lamarcki harboured different Symbiodinium types across its depth distribution (i.e. exhibited symbiont zonation). Phylogenetic analysis (atp6) of the coral hosts demonstrated a division of the Agaricia genus into two major lineages that correspond to their bathymetric distribution ("shallow": A. humilis / A. agaricites and "deep": A. lamarcki / A. grahamae), highlighting the role of depth-related factors in the diversification of these congeneric agariciid species. The divergence between "shallow" and "deep" host species was reflected in the relatedness of the associated Symbiodinium (with A. lamarcki and A. grahamae sharing an identical Symbiodinium profile, and A. humilis and A. agaricites harbouring a related ITS2 sequence in their Symbiodinium profiles), corroborating the notion that brooding corals and their Symbiodinium are engaged in coevolutionary processes.<br><br>CONCLUSIONS: Our findings support the hypothesis that the depth-related environmental gradient on reefs has played an important role in the diversification of the genus Agaricia and their associated Symbiodinium, resulting in a genetic segregation between coral host-symbiont communities at shallow and mesophotic depths.}, }
@article {pmid24053607, year = {2013}, author = {Ioannidis, P and Johnston, KL and Riley, DR and Kumar, N and White, JR and Olarte, KT and Ott, S and Tallon, LJ and Foster, JM and Taylor, MJ and Dunning Hotopp, JC}, title = {Extensively duplicated and transcriptionally active recent lateral gene transfer from a bacterial Wolbachia endosymbiont to its host filarial nematode Brugia malayi.}, journal = {BMC genomics}, volume = {14}, number = {}, pages = {639}, pmid = {24053607}, issn = {1471-2164}, support = {DP2 OD007372/OD/NIH HHS/United States ; 1-DP2-OD007372/OD/NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/*genetics ; DNA, Bacterial/genetics ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Genome, Helminth ; Open Reading Frames ; Sequence Analysis, DNA ; Wolbachia/*genetics ; }, abstract = {BACKGROUND: Lymphatic filariasis is a neglected tropical disease afflicting more than 120 million people, while another 1.3 billion people are at risk of infection. The nematode worm Brugia malayi is one of the causative agents of the disease and exists in a mutualistic symbiosis with Wolbachia bacteria. Since extensive lateral gene transfer occurs frequently between Wolbachia and its hosts, we sought to measure the extent of such LGT in B. malayi by whole genome sequencing of Wolbachia-depleted worms.<br><br>RESULTS: A considerable fraction (at least 115.4-kbp, or 10.6%) of the 1.08-Mbp Wolbachia wBm genome has been transferred to its nematode host and retains high levels of similarity, including 227 wBm genes and gene fragments. Complete open reading frames were transferred for 32 of these genes, meaning they have the potential to produce functional proteins. Moreover, four transfers have evidence of life stage-specific regulation of transcription at levels similar to other nematode transcripts, strengthening the possibility that they are functional.<br><br>CONCLUSIONS: There is extensive and ongoing transfer of Wolbachia DNA to the worm genome and some transfers are transcribed in a stage-specific manner at biologically relevant levels.}, }
@article {pmid24046865, year = {2013}, author = {Sohlenkamp, C and Raetz, CR and Ingram, BO}, title = {The calcium-stimulated lipid A 3-O deacylase from Rhizobium etli is not essential for plant nodulation.}, journal = {Biochimica et biophysica acta}, volume = {1831}, number = {7}, pages = {1250-1259}, pmid = {24046865}, issn = {0006-3002}, support = {GM-069338/GM/NIGMS NIH HHS/United States ; GM-51796/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Calcium/*metabolism ; Carboxylic Ester Hydrolases/chemistry/genetics/*metabolism ; Gene Deletion ; Lipid A/*metabolism ; Molecular Sequence Data ; Mutation ; Nitrogen Fixation ; Phaseolus/*microbiology/physiology ; Plant Root Nodulation ; Rhizobium etli/chemistry/*enzymology/genetics/*physiology ; Salmonella typhimurium/enzymology ; Sequence Alignment ; Symbiosis ; }, abstract = {The lipid A component of lipopolysaccharide from the nitrogen-fixing plant endosymbiont, Rhizobium etli, is structurally very different from that found in most enteric bacteria. The lipid A from free-living R. etli is structurally heterogeneous and exists as a mixture of species which are either pentaacylated or tetraacylated. In contrast, the lipid A from R. etli bacteroids is reported to consist exclusively of tetraacylated lipid A species. The tetraacylated lipid A species in both cases lack a beta-hydroxymyristoyl chain at the 3-position of lipid A. Here, we show that the lipid A modification enzyme responsible for 3-O deacylation in R. etli is a homolog of the PagL protein originally described in Salmonella enterica sv. typhimurium. In contrast to the PagL proteins described from other species, R. etli PagL displays a calcium dependency. To determine the importance of the lipid A modification catalyzed by PagL, we isolated and characterized a R. etli mutant deficient in the pagL gene. Mass spectrometric analysis confirmed that the mutant strain was exclusively tetraacylated and radiochemical analysis revealed that 3-O deacylase activity was absent in membranes prepared from the mutant. The R. etli mutant was not impaired in its ability to form nitrogen-fixing nodules on Phaseolus vulgaris but it displayed slower nodulation kinetics relative to the wild-type strain. The lipid A modification catalyzed by R. etli PagL, therefore, is not required for nodulation but may play other roles such as protecting bacterial endosymbionts from plant immune responses during infection.}, }
@article {pmid24044755, year = {2013}, author = {Nutman, TB}, title = {Insights into the pathogenesis of disease in human lymphatic filariasis.}, journal = {Lymphatic research and biology}, volume = {11}, number = {3}, pages = {144-148}, pmid = {24044755}, issn = {1557-8585}, support = {//Intramural NIH HHS/United States ; }, mesh = {Animals ; Elephantiasis, Filarial/*parasitology ; Filarioidea/microbiology/*physiology ; Host-Parasite Interactions ; Host-Pathogen Interactions ; Humans ; Lymph Nodes/*parasitology/pathology ; Lymphatic System/*parasitology/pathology ; Wolbachia/physiology ; }, abstract = {Although two thirds of the 120 million people infected with lymph-dwelling filarial parasites have subclinical infections, ∼40 million have lymphedema and/or other pathologic manifestations including hydroceles (and other forms of urogenital disease), episodic adenolymphangitis, lymphedema, and (in its most severe form) elephantiasis. Adult filarial worms reside in the lymphatics and lymph nodes and induce lymphatic dilatation. Progressive lymphatic damage and pathology results primarily from the host inflammatory response to the parasites but also perhaps from the host inflammatory response to the parasite's Wolbachia endosymbiont and as a consequence of superimposed bacterial or fungal infections. This review will attempt to shed light on disease pathogenesis in lymphatic filariasis.}, }
@article {pmid24024639, year = {2013}, author = {Kondorosi, E and Mergaert, P and Kereszt, A}, title = {A paradigm for endosymbiotic life: cell differentiation of Rhizobium bacteria provoked by host plant factors.}, journal = {Annual review of microbiology}, volume = {67}, number = {}, pages = {611-628}, doi = {10.1146/annurev-micro-092412-155630}, pmid = {24024639}, issn = {1545-3251}, mesh = {Biological Evolution ; Fabaceae/*microbiology/physiology ; Plant Roots/microbiology/physiology ; Rhizobium/genetics/growth &amp; development/*physiology ; *Symbiosis ; }, abstract = {Symbiosis between Rhizobium bacteria and legumes leads to the formation of the root nodule. The endosymbiotic bacteria reside in polyploid host cells as membrane-surrounded vesicles where they reduce atmospheric nitrogen to support plant growth by supplying ammonia in exchange for carbon sources and energy. The morphology and physiology of endosymbionts, despite their common function, are highly divergent in different hosts. In galegoid plants, the endosymbionts are terminally differentiated, uncultivable polyploid cells, with remarkably elongated and even branched Y-shaped cells. Bacteroid differentiation is controlled by host peptides, many of which have antibacterial activity and require the bacterial function of BacA. Although the precise and combined action of several hundred host peptides and BacA has yet to be discovered, similarities, especially to certain insect-bacterium symbioses involving likewise host peptides for manipulation of endosymbionts, suggest convergent evolution. Rhizobium-legume symbiosis provides a rich source of information for understanding host-controlled endosymbiotic life in eukaryotic cells.}, }
@article {pmid24019989, year = {2013}, author = {Fiebig, A and Pradella, S and Petersen, J and Päuker, O and Michael, V and Lünsdorf, H and Göker, M and Klenk, HP and Wagner-Döbler, I}, title = {Genome of the R-body producing marine alphaproteobacterium Labrenzia alexandrii type strain (DFL-11(T)).}, journal = {Standards in genomic sciences}, volume = {7}, number = {3}, pages = {413-426}, pmid = {24019989}, issn = {1944-3277}, abstract = {Labrenzia alexandrii Biebl et al. 2007 is a marine member of the family Rhodobacteraceae in the order Rhodobacterales, which has thus far only partially been characterized at the genome level. The bacterium is of interest because it lives in close association with the toxic dinoflagellate Alexandrium lusitanicum. Ultrastructural analysis reveals R-bodies within the bacterial cells, which are primarily known from obligate endosymbionts that trigger "killing traits" in ciliates (Paramecium spp.). Genomic traits of L. alexandrii DFL-11(T) are in accordance with these findings, as they include the reb genes putatively involved in R-body synthesis. Analysis of the two extrachromosomal elements suggests a role in heavy-metal resistance and exopolysaccharide formation, respectively. The 5,461,856 bp long genome with its 5,071 protein-coding and 73 RNA genes consists of one chromosome and two plasmids, and has been sequenced in the context of the Marine Microbial Initiative.}, }
@article {pmid25023877, year = {2013}, author = {Porcar, M and Latorre, A and Moya, A}, title = {What Symbionts Teach us about Modularity.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {1}, number = {}, pages = {14}, pmid = {25023877}, issn = {2296-4185}, abstract = {The main goal of Synthetic Biology (SB) is to apply engineering principles to biotechnology in order to make life easier to engineer. These engineering principles include modularity: decoupling of complex systems into smaller, orthogonal sub-systems that can be used in a range of different applications. The successful use of modules in engineering is expected to be reproduced in synthetic biological systems. But the difficulties experienced up to date with SB approaches question the short-term feasibility of designing life. Considering the "engineerable" nature of life, here we discuss the existence of modularity in natural living systems, particularly in symbiotic interactions, and compare the behavior of such systems, with those of engineered modules. We conclude that not only is modularity present but it is also common among living structures, and that symbioses are a new example of module-like sub-systems having high similarity with modularly designed ones. However, we also detect and stress fundamental differences between man-made and biological modules. Both similarities and differences should be taken into account in order to adapt SB design to biological laws.}, }
@article {pmid24672682, year = {2012}, author = {Gentil, K and Hoerauf, A and Pearlman, E}, title = {Differential induction of Th2- and Th1-associated responses by filarial antigens and endosymbiotic Wolbachia in a murine model of river blindness.}, journal = {European journal of microbiology &amp; immunology}, volume = {2}, number = {2}, pages = {134-139}, pmid = {24672682}, issn = {2062-509X}, abstract = {Immune responses to filarial parasites like the river blindness inducing Onchocerca volvulus are obscured by combined reactions to the filarial nematodes themselves and their endosymbiont bacteria Wolbachia. Overall, infection with filarial nematodes induces a strong Th2 response characterized by IL-5 production and to a lesser degree a Th1 response and IFNγ production. Neutrophil and eosinophil infiltration into the corneal stroma are hallmark features of Onchocerca volvulus stimulation in a mouse model of river blindness. To determine the splenic and corneal response to filarial antigens in the absence of Wolbachia, C57BL/6 mice were immunized subcutaneously with either endosymbiotic Wolbachia alone, a soluble extract from the filaria Acanthocheilonema viteae that does not contain Wolbachia, or both, and injected into the corneal stroma. Neutrophil and eosinophil infiltration into the cornea was assessed by immunohistochemistry. In addition, Th1- and Th2-associated responses to filaria or Wolbachia were investigated by determining IL-5 and IFN-γ production by splenocytes. We found that A. viteae in the absence of Wolbachia induced IL-5 production and eosinophil infiltration, but not IFN-γ. Conversely, Wolbachia induced IFN-γ production and no migration of eosinophils. There was no difference in neutrophil infiltration. Together, these findings demonstrate a distinct Th-associated phenotype induced by filaria and Wolbachia.}, }
@article {pmid24031884, year = {2012}, author = {León-Martínez, DG and Vielle-Calzada, JP and Olalde-Portugal, V}, title = {Expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of Glomus intraradices.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {43}, number = {2}, pages = {716-738}, pmid = {24031884}, issn = {1517-8382}, abstract = {To explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus Glomus, we transcriptionally analysed spores of Glomus intraradices BE3 during early hyphal growth. Among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacterial genes. Among them, GintPbr1a encodes a homolog to Phenazine Biosynthesis Regulator (Pbr) of Burkholderia cenocepacia, an pleiotropic regulatory protein that activates phenazine production through transcriptional activation of the protein D isochorismatase biosynthetic enzyme phzD (Ramos et al., 2010). Whereas GintPbr1a is expressed during the presymbiotic phase, the G. intraradices BE3 homolog of phzD (BGintphzD) is transcriptionally active at the time of the establishment of the arbuscular mycorrhizal symbiosis. DNA from isolated bacterial cultures found in spores of G. intraradices BE3 confirmed that both BGintPbr1a and BGintphzD are present in the genome of its potential endosymbionts. Taken together, our results indicate that spores of G. intraradices BE3 express bacterial phenazine biosynthetic genes at the onset of the fungal-plant symbiotic interaction.}, }
@article {pmid26467959, year = {2012}, author = {Gruwell, ME and Flarhety, M and Dittmar, K}, title = {Distribution of the Primary Endosymbiont (Candidatus Uzinura Diaspidicola) Within Host Insects from the Scale Insect Family Diaspididae.}, journal = {Insects}, volume = {3}, number = {1}, pages = {262-269}, pmid = {26467959}, issn = {2075-4450}, abstract = {It has long been known that armored scale insects harbor endosymbiotic bacteria inside specialized cells called bacteriocytes. Originally, these endosymbionts were thought to be fungal symbionts but they are now known to be bacterial and have been named Uzinura diaspidicola. Bacteriocyte and endosymbiont distribution patterns within host insects were visualized using in situ hybridization via 16S rRNA specific probes. Images of scale insect embryos, eggs and adult scale insects show patterns of localized bacteriocytes in embryos and randomly distributed bacteriocytes in adults. The symbiont pocket was not found in the armored scale insect eggs that were tested. The pattern of dispersed bacteriocytes in adult scale insects suggest that Uzinura and Blattabacteria may share some homologous traits that coincide with similar life style requirements, such as dispersal in fat bodies and uric acid recycling.}, }
@article {pmid26467958, year = {2012}, author = {Goodacre, SL and Martin, OY}, title = {Modification of Insect and Arachnid Behaviours by Vertically Transmitted Endosymbionts: Infections as Drivers of Behavioural Change and Evolutionary Novelty.}, journal = {Insects}, volume = {3}, number = {1}, pages = {246-261}, pmid = {26467958}, issn = {2075-4450}, abstract = {Vertically acquired, endosymbiotic bacteria such as those belonging to the Rickettsiales and the Mollicutes are known to influence the biology of their arthropod hosts in order to favour their own transmission. In this study we investigate the influence of such reproductive parasites on the behavior of their insects and arachnid hosts. We find that changes in host behavior that are associated with endosymbiont infections are not restricted to characteristics that are directly associated with reproduction. Other behavioural traits, such as those involved in intraspecific competition or in dispersal may also be affected. Such behavioural shifts are expected to influence the level of intraspecific variation and the rate at which adaptation can occur through their effects on effective population size and gene flow amongst populations. Symbionts may thus influence both levels of polymorphism within species and the rate at which diversification can occur.}, }
@article {pmid26467955, year = {2012}, author = {Kageyama, D and Narita, S and Watanabe, M}, title = {Insect Sex Determination Manipulated by Their Endosymbionts: Incidences, Mechanisms and Implications.}, journal = {Insects}, volume = {3}, number = {1}, pages = {161-199}, pmid = {26467955}, issn = {2075-4450}, abstract = {The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations.}, }
@article {pmid26466544, year = {2012}, author = {Ratzka, C and Gross, R and Feldhaar, H}, title = {Endosymbiont Tolerance and Control within Insect Hosts.}, journal = {Insects}, volume = {3}, number = {2}, pages = {553-572}, pmid = {26466544}, issn = {2075-4450}, abstract = {Bacterial endosymbioses are very common in insects and can range from obligate to facultative as well as from mutualistic to pathogenic associations. Several recent studies provide new insight into how endosymbionts manage to establish chronic infections of their hosts without being eliminated by the host immune system. Endosymbiont tolerance may be achieved either by specific bacterial adaptations or by host measurements shielding bacteria from innate defense mechanisms. Nevertheless, insect hosts also need to sustain control mechanisms to prevent endosymbionts from unregulated proliferation. Emerging evidence indicates that in some cases the mutual adaptations of the two organisms may have led to the integration of the endosymbionts as a part of the host immune system. In fact, endosymbionts may provide protective traits against pathogens and predators and may even be required for the proper development of the host immune system during host ontogeny. This review gives an overview of current knowledge of molecular mechanisms ensuring maintenance of chronic infections with mutualistic endosymbionts and the impact of endosymbionts on host immune competence.}, }
@article {pmid24031693, year = {2011}, author = {Marcon, HS and Coscrato, VE and Selivon, D and Perondini, AL and Marino, CL}, title = {Variations in the sensitivity of different primers for detecting Wolbachia in Anastrepha (diptera: tephritidae).}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {42}, number = {2}, pages = {778-785}, pmid = {24031693}, issn = {1517-8382}, abstract = {Wolbachia are endosymbiont bacteria of the family Rickettsiacea that are widespread in invertebrates and occur between 20% and 60% of Neotropical insects. These bacteria are responsible for reproductive phenomena such as cytoplasmic incompatibility, male killing, feminization and parthenogenesis. Supergroups A and B of Wolbachia are common in insects and can be identified using primers for 16S rDNA, ftsZ and wsp; these primers vary in their ability to detect Wolbachia. The ftsZ primer was the first primer used to detect Wolbachia in Anastrepha fruit flies. The primers for 16S rDNA, ftsZ and wsp and the corresponding PCR conditions have been optimized to study the distribution of Wolbachia and their effect on the biology of Anastrepha in Brazil. In this work, we examined the ability of these primers to detect Wolbachia in Anastrepha populations from three regions in the State of São Paulo, southeastern Brazil. All of the samples were positive for Wolbachia supergroup A when screened with primers for 16S A rDNA and wsp A; the wsp B primer also gave a positive result, indicating cross-reactivity. The ftsZ primer showed a poor ability to detect Wolbachia in Anastrepha and generated false negatives in 44.9% of the samples. These findings indicate that reliable PCR detection of Wolbachia requires the use of primers for 16S rDNA and wsp to avoid cross-reactions and false negatives, and that the ftsZ primer needs to be redesigned to improve its selectivity.}, }
@article {pmid26467737, year = {2011}, author = {Vogel, KJ and Moran, NA}, title = {Effect of Host Genotype on Symbiont Titer in the Aphid-Buchnera Symbiosis.}, journal = {Insects}, volume = {2}, number = {3}, pages = {423-434}, pmid = {26467737}, issn = {2075-4450}, abstract = {Obligate nutritional symbioses require balance between the energetic needs of the host and the symbiont. The resident symbiont population size within a host may have major impacts on host fitness, as both host and symbiont consume and supply metabolites in a shared metabolite pool. Given the massive genome degradation that is a hallmark of bacterial endosymbionts of insects, it is unclear at what level these populations are regulated, and how regulation varies among hosts within natural populations. We measured the titer of the endosymbiont Buchnera aphidicola from different clones of the pea aphid, Acyrthosiphon pisum, and found significant variation in titer, measured as Buchnera genomes per aphid genome, among aphid clones. Additionally, we found that titer can change with the age of the host, and that the number of bacteriocytes within an aphid is one factor likely controlling Buchnera titer. Buchnera titer measurements in clones from a sexual cross indicate that the symbiont genotype is not responsible for variation in titer and that this phenotype is likely non-heritable across sexual reproduction. Symbiont titer is more variable among lab-produced F1 aphid clones than among field-collected ones, suggesting that intermediate titer is favored in natural populations. Potentially, a low heritability of titer during the sexual phase may generate clones with extreme and maladaptive titers each season.}, }
@article {pmid26467727, year = {2011}, author = {Jenkins, TM and Eaton, TD}, title = {Population Genetic Baseline of the First Plataspid Stink Bug Symbiosis (Hemiptera: Heteroptera: Plataspidae) Reported in North America.}, journal = {Insects}, volume = {2}, number = {3}, pages = {264-272}, pmid = {26467727}, issn = {2075-4450}, abstract = {The stink bug, Megacopta cribraria, has an obligate relationship with a bacterial endosymbiont which allows it to feed on legumes. The insect is a pest of soybeans in Asia and was first reported in the Western Hemisphere in October 2009 on kudzu vine, Pueraria montana, in North Georgia, USA. By October 2010 M. cribraria had been confirmed in 80 counties in Georgia actively feeding on kudzu vine and soybean plants. Since the symbiosis may support the bug's ecological expansions, a population genetic baseline for the symbiosis was developed from mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA) gene sequence collected from each insect and its primary g- proteobacterium and secondary a -proteobacterium endosymbionts. A single mitochondrial DNA haplotype was found in all insects sampled in Georgia and South Carolina identified as GA1. The GAI haplotype appears to be rapidly dispersing across Georgia and into contiguous states. Primary and secondary endosymbiont gene sequences from M. cribraria in Georgia were the same as those found in recently collected Megacopta samples from Japan. The implications of these data are discussed.}, }
@article {pmid25241406, year = {2010}, author = {Stahlhut, JK}, title = {The endosymbiont community as taxonomic character: a novel approach to resolving the Bemisia tabaci complex.}, journal = {Molecular ecology}, volume = {19}, number = {19}, pages = {4102-4104}, doi = {10.1111/j.1365-294x.2010.04776.x}, pmid = {25241406}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification ; *Biological Evolution ; Hemiptera/*genetics/*microbiology ; *Phylogeny ; *Symbiosis ; }, abstract = {In this issue of Molecular Ecology, Gueguen et al. (2010) describe their novel approach to resolving cryptic genetic diversity in the Bemisia tabaci complex (Hemiptera: Aleyrodidae.) Complexes of cryptic species present a challenge to both morphological and molecular taxonomy – the former presumed, as shared morphology normally defines species as cryptic, but the latter also problematic when host DNA sequence data is either inconclusive or unaccompanied by independent evidence. Endosymbiont associations with insect hosts have, historically, complicated efforts to develop a robust molecular taxonomy, but the approach of Gueguen et al. takes advantage of endosymbiont community composition to help rather than hinder the task of resolving taxonomic distinctions within the B. tabaci complex.}, }
@article {pmid27032347, year = {2009}, author = {Smith, RT and Pinzón, JH and LaJeunesse, TC}, title = {SYMBIODINIUM (DINOPHYTA) DIVERSITY AND STABILITY IN AQUARIUM CORALS(1).}, journal = {Journal of phycology}, volume = {45}, number = {5}, pages = {1030-1036}, doi = {10.1111/j.1529-8817.2009.00730.x}, pmid = {27032347}, issn = {0022-3646}, abstract = {Indo-Pacific reef corals growing for years in closed-system aquaria provide an alternate means to investigate host-symbiont specificity and stability. The diversity of dinoflagellate endosymbionts (Symbiodinium spp.) from coral communities in private and public aquaria was investigated using molecular-genetic analyses. Of the 29 symbiont types (i.e., species) identified, 90% belonged to the most prevalent group of Symbiodinium harbored by Indo-Pacific reef corals, Clade C, while the rest belonged to Clade D. Sixty-five percent of all types were known from field surveys conducted throughout the Pacific and Indian oceans. Because specific coral-dinoflagellate partnerships appear to have defined geographic distributions, correspondence of the same symbionts in aquarium and field-collected specimens identifies regions where particular colonies must have been collected in the wild. Symbiodinium spp. in clade D, believed to be "stress-tolerant" and/or "opportunistic," occurred in a limited number of individual colonies. The absence of a prevalent, or "weedy," symbiont suggests that conditions under which aquarium corals are grown do not favor competitive replacements of their native symbiont populations. The finding of typical and diverse assemblages of Symbiodinium spp. among aquarium corals living many years under variable chemical/physical conditions, artificial and natural light, while undergoing fragmentation periodically, indicates that individual colonies maintain stable, long-term symbiotic associations.}, }
@article {pmid24031358, year = {2009}, author = {Tian, F and Ding, Y and Zhu, H and Yao, L and Du, B}, title = {Genetic diversity of siderophore-producing bacteria of tobacco rhizosphere.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {40}, number = {2}, pages = {276-284}, pmid = {24031358}, issn = {1517-8382}, abstract = {The genetic diversity of siderophore-producing bacteria of tobacco rhizosphere was studied by amplified ribosomal DNA restriction analysis (ARDRA), 16S rRNA sequence homology and phylogenetics analysis methods. Studies demonstrated that 85% of the total 354 isolates produced siderophores in iron limited liquid medium. A total of 28 ARDRA patterns were identified among the 299 siderophore-producing bacterial isolates. The 28 ARDRA patterns represented bacteria of 14 different genera belonging to six bacterial divisions, namely β-, γ-, α-Proteobacteria, Sphingobacteria, Bacilli, and Actinobacteria. Especially, γ-Proteobacteria consisting of Pseudomonas, Enterobacter, Serratia, Pantoea, Erwinia and Stenotrophomonas genus encountered 18 different ARDRA groups. Results also showed a greater siderophore-producing bacterial diversity than previous researches. For example, Sphingobacterium (isolates G-2-21-1 and G-2-27-2), Pseudomonas poae (isolate G-2-1-1), Enterobacter endosymbiont (isolates G-2-10-2 and N-5-10), Delftia acidovorans (isolate G-1-15), and Achromobacter xylosoxidans (isolates N-46-11HH and N-5-20) were reported to be able to produce siderophores under low-iron conditions for the first time. Gram-negative isolates were more frequently encountered, with more than 95% total frequency. For Gram-positive bacteria, the Bacillus and Rhodococcus were the only two genera, with 1.7% total frequency. Furthermore, the Pseudomonas and Enterobacter were dominant in this environment, with 44.5% and 24.7% total frequency, respectively. It was also found that 75 percent of the isolates that had the high percentages of siderophore units (% between 40 and 60) belonged to Pseudomonas. Pseudomonas sp. G-229-21 screened out in this study may have potential to apply to low-iron soil to prevent plant soil-borne fungal pathogen diseases.}, }
@article {pmid27041420, year = {2008}, author = {Sriwoon, R and Pholpunthin, P and Lirdwitayaprasit, T and Kishino, M and Furuya, K}, title = {POPULATION DYNAMICS OF GREEN NOCTILUCA SCINTILLANS (DINOPHYCEAE) ASSOCIATED WITH THE MONSOON CYCLE IN THE UPPER GULF OF THAILAND(1).}, journal = {Journal of phycology}, volume = {44}, number = {3}, pages = {605-615}, doi = {10.1111/j.1529-8817.2008.00516.x}, pmid = {27041420}, issn = {0022-3646}, abstract = {Population dynamics of Noctiluca scintillans (Macartney) Kof. et Swezy containing the photosynthetic endosymbiont Pedinomonas noctilucae (Subrahman.) Sweeney was investigated in relation to environmental conditions in the upper Gulf of Thailand. A clear association was observed between the abundance of N. scintillans and the monsoon cycle, with its blooms occurring during the southwest (SW) monsoon from May to September, and low abundance during the northeast (NE) monsoon from November to February. Nutrient concentrations were higher during the SW monsoon than during the NE monsoon due to the combined effect of increased river discharge into the northern upper gulf and the transport of the riverine inputs by the prevailing clockwise circulation of the water. These nutrient conditions favored the growth of both phytoplankton and the endosymbiont. Correlation analysis revealed that the higher abundance of N. scintillans in the SW monsoon was manifested primarily by higher growth through both sexual and asexual reproduction supported by phagotrophy. However, the dependence of N. scintillans on the nutrient concentration was not significant, probably because the nutrient supply for the endosymbiont was sufficient due to intracellular accumulation of nutrients within the host cells. Sexual reproduction occurred only during the SW monsoon, and its potential importance in population growth was suggested. These findings showed the bottom-up control of the population dynamics of N. scintillans through growth of phytoplankton as prey. The seasonal shift in the circulation pattern associated with the monsoon cycle played a crucial role in blooming of N. scintillans by producing favorable food conditions.}, }
@article {pmid27041036, year = {2008}, author = {Gould, SB}, title = {ARIADNE'S THREAD: GUIDING A PROTEIN ACROSS FIVE MEMBRANES IN CRYPTOPHYTES(1).}, journal = {Journal of phycology}, volume = {44}, number = {1}, pages = {23-26}, doi = {10.1111/j.1529-8817.2007.00437.x}, pmid = {27041036}, issn = {0022-3646}, abstract = {Cryptophytes are the most archetypal chromalveolates, with their complex plastid having retained many features of the red algal secondary endosymbiont. Most important of these is the remnant nucleus, the nucleomorph, that is kept between the inner and outer membrane pair of the endosymbiont in the highly reduced cytosol, the periplastidial compartment (PPC). Because the nucleomorph's coding capacity is very limited, proteins need to be imported from the host cytosol across the outer two membranes into the PPC and across all four membranes into the stroma. How this is accomplished has puzzled researchers for >20 years. Recent findings show that in both cases, a bipartite topogenic signal, a signal and subsequent transit peptide (TP), is responsible for targeting proteins correctly into these two compartments. An aromatic amino acid-based motif at the +1 position of the TP holds the information determining into which compartment the precursor protein is finally transported. Together with the identification of a novel endoplasmic reticulum associated degradation (ERAD)-derived translocon in the second-outermost membrane, these findings help us to understand the sophisticated targeting mechanisms across four membranes and clarify a key innovation during chromalveolate evolution.}, }
@article {pmid27041033, year = {2008}, author = {Phipps, KD and Donaher, NA and Lane, CE and Archibald, JM}, title = {NUCLEOMORPH KARYOTYPE DIVERSITY IN THE FRESHWATER CRYPTOPHYTE GENUS CRYPTOMONAS(1).}, journal = {Journal of phycology}, volume = {44}, number = {1}, pages = {11-14}, doi = {10.1111/j.1529-8817.2007.00434.x}, pmid = {27041033}, issn = {0022-3646}, abstract = {Cryptophytes are unicellular, biflagellate algae with plastids (chloroplasts) derived from the uptake of a red algal endosymbiont. These organisms are unusual in that the nucleus of the engulfed red alga persists in a highly reduced form called a nucleomorph. Nucleomorph genomes are remarkable in their small size (<1,000 kilobase pairs [kbp]) and high degree of compaction (∼1 kbp per gene). Here, we investigated the molecular and karyotypic diversity of nucleomorph genomes in members of the genus Cryptomonas. 18S rDNA genes were amplified, sequenced, and analyzed from C. tetrapyrenoidosa Skuja CCAP979/63, C. erosa Ehrenb. emmend. Hoef-Emden CCAP979/67, Cryptomonas sp. CCAP979/52, C. lundii Hoef-Emden et Melkonian CCAP979/69, and C. lucens Skuja CCAP979/35 in the context of a large set of publicly available nucleomorph 18S rDNA sequences. Pulsed-field gel electrophoresis (PFGE) was used to examine the nucleomorph genome karyotype of each of these strains. Individual chromosomes ranged from ∼160 to 280 kbp in size, with total genome sizes estimated to be ∼600-655 kbp. Unexpectedly, the nucleomorph karyotype of Cryptomonas sp. CCAP979/52 is significantly different from that of C. tetrapyrenoidosa and C. lucens, despite the fact that their 18S rDNA genes are >99% identical to one another. These results suggest that nucleomorph karyotype similarity is not a reliable indicator of evolutionary affinity and provides a starting point for further investigation of the fine-scale dynamics of nucleomorph genome evolution within members of the genus Cryptomonas.}, }
@article {pmid24937882, year = {2004}, author = {,  and Guerrero, J and McCall, JW and Genchi, C and Bazzocchi, C and Kramer, L and Simòn, F and Martarino, M}, title = {Recent advances in heartworm disease.}, journal = {Veterinary parasitology}, volume = {125}, number = {1-2}, pages = {105-130}, doi = {10.1016/j.vetpar.2004.05.008}, pmid = {24937882}, issn = {1873-2550}, mesh = {Animals ; Anthelmintics/*therapeutic use ; Dirofilariasis/*drug therapy ; Dog Diseases/*drug therapy ; Dogs ; Nematoda/physiology ; }, abstract = {This compilation of articles consists of four papers presented at the 19th International Conference of the World Association for the Advancement of Veterinary Parasitology (WAAVP) (held in New Orleans, LA, USA, on 10–14 August 2003) in a symposium session titled “ Recent Advances in Heartworm Disease,” organized and chaired by JohnW. McCall and Jorge Guerrero. The first paper(Guerrero) covered the American Heartworm Society’s most recent revision of their guidelines for the diagnosis, prevention, and management of heartworm infection in dogs, based on new research and clinical experience, particularly in the areas of heartworm chemoprophylaxis, adulticide therapy,and serologic testing and retesting. The entire updated 2003 “Guidelines” are presented herein.One paper (McCall) reviewed the “soft-kill” adulticidal and “safety-net” (reach-back, retroactive,clinical prophylactic) activity of prolonged dosing of prophylactic doses of macrocyclic lactones,concluding that ivermectin is the most effective in this way, milbemycin oxime is the least effective,and the activity of injectable moxidectin and selamectin lies between that of ivermectin and milbemycin oxime. The two remaining papers provided an overview of the discovery, rediscovery,phylogeny, and biological association between Wolbachia endosymbionts and filarial nematodes(Genchi and co-authors) and compelling evidence that Wolbachia may play a major role in the immunopathogenesis of filarial diseases of man and animals (Kramer and co-authors).}, }
@article {pmid24430998, year = {1988}, author = {Smeekens, S and Weisbeek, P}, title = {Protein transport towards the thylakoid lumen: post-translational translocation in tandem.}, journal = {Photosynthesis research}, volume = {16}, number = {1-2}, pages = {177-186}, pmid = {24430998}, issn = {0166-8595}, abstract = {Many proteins found in the chloroplast are synthesized in the cytoplasm as precursor molecules containing transit peptides. Proteins targeted to the stroma must pass through the two envelope membranes to reach their destination. Proteins located in the chloroplast lumen also have to be transferred across the thylakoid membrane. That is, lumen proteins must cross three biological membranes in order to reach their final location. Recent evidence shows that the routing of plastocyanin towards the lumen involves two post-translational transport processes mediated by two different regions of the transit peptide and two different processing proteases. It is postulated that the genetic information for the plastocyanin precursor, which already contained a signal peptide, was transferred from the endosymbiont to the nucleus. Then a chloroplast-specific targeting-peptide was added.}, }
@article {pmid24276967, year = {1987}, author = {Morrison, N and Verma, DP}, title = {A block in the endocytosis of Rhizobium allows cellular differentiation in nodules but affects the expression of some peribacteroid membrane nodulins.}, journal = {Plant molecular biology}, volume = {9}, number = {3}, pages = {185-196}, pmid = {24276967}, issn = {0167-4412}, abstract = {A transposon-induced mutant (T8-1) of Bradyrhizobium japonicum (61A76) was unable to develop into the nitrogen-fixing endosymbiotic form, the bacteroid. Comparison between this mutant and T5-95, an ineffective (non-nitrogen fixing, Fix(-)) mutant, confirmed that the process of bacteroid development is a distinct phase of differentiation of the endosymbiont and is independent of nitrogen fixation activity. The T8-1 mutant was able to induce normal-size nodules which differentiated two plant cell types and contained numerous infection threads. However, the infected cells were devoid of bacteroids. Electron microscopy revealed that the ends of the infection threads were broken down in a normal manner once the thread had penetrated the cells, but the mutant was not internalized by endocytosis. The lack of peribacteroid membrane (PBM) in nodules induced by this mutant was correlated with a reduced level of expression of plant genes coding for PBM nodulins. These genes were expressed in the T5-95 mutant, showing that the low expression in T8-1 was not due to the lack of nitrogen fixation. One of the PBM nodulins, nodulin-26, was found at normal levels in the nodules which lack PBM, suggesting that there are at least two developmental stages in PBM biosynthesis. These data suggest that a coordination of plant and Rhizobium gene expression is required for the release and internalization of bacteria into the PBM compartments of infected cells of nodules.}, }
@article {pmid28308799, year = {1974}, author = {Jurzitza, G}, title = {[Furnishing of sterol by the yeast-like endosymbionts of Lasioderma serricorne F. (Coleoptera, Anobiidae) and Its ecological importance for the host].}, journal = {Oecologia}, volume = {16}, number = {2}, pages = {163-172}, pmid = {28308799}, issn = {1432-1939}, abstract = {By comparing the growth of normal and aposymbiontic Lasioderma serricorne on diets of increasing cholesterol amounts, we demonstrated that the endosymbionts furnish sterols in quantities comparable to a cholesterol concentration of 0.01-0.03% in the diet (Fig. 1). We reared aposymbiontic larvae in diets without added sterol, which contained 50% of samples of different woods or cigarette tobacco. With fresh Aesculus wood and tobacco, larval growth was optimal. Other fresh woods (Acer, Prunus, Fagus, Quercus, Nothofagus) retarded development (Table 1). Old coniferous woods permitted almost no growth. In diets containing chloroform-extracted coigue wood (Sample No. 7), no growth occured. The diet of extract enabled the larvae to grow faster than that of unextracted wood. Thus, the larvae seem unable to utilize sufficiently the sterol content of wood. The ecological significance of these results and the importance of symbiontic microorganisms as sterol sources for insects are discussed.}, }
@article {pmid27064707, year = {1967}, author = {Hall, WT and Claus, G}, title = {ULTRASTRUCTURAL STUDIES ON THE CYANELLES OF GLAUCOCYSTIS NOSTOCHINEARUM ITZIGSOHN(1).}, journal = {Journal of phycology}, volume = {3}, number = {1}, pages = {37-51}, doi = {10.1111/j.1529-8817.1967.tb04627.x}, pmid = {27064707}, issn = {0022-3646}, abstract = {Ultrastructural studies conducted on the intracellular symbiont of Glaucocystis nostochinearum Itz., a unicellular alga with a debated taxonomic position, have shown that the endosymbiont, although somewhat aberrant, is a blue-green alga. Due possibly to its intracellular habitat, it lacks the characteristic cyanophycean double-layered cell wall and the cells appear to be completely naked, bound only by a single plasma membrane. The protoplasm of the cell is differentiated into the lamellated chromatoplasm, which contains the photosynthetic pigments and polyphosphate granules, and a nonlamellar ccntroplasm, in which the nucleic material is dispersed. The usual cyanophycean organelles, as well as the different vacuoles and granules, with the exception of the formed bodies, are missing. Approximately 10% of the cells sliows a peculiar homogeneous area at one tip, the nature of which is unknown. Binary fission of the organism is mentioned. Since this cyanelle has not yet been classified, we name it Skujapelta nuda nov. gen., nov. sp.; and because of its structural peculiarities we find it necessary to create a new family for it, Skujapeltaceae in the order Chroococcales.}, }
@article {pmid24015778, year = {2013}, author = {Alves, JM and Klein, CC and da Silva, FM and Costa-Martins, AG and Serrano, MG and Buck, GA and Vasconcelos, AT and Sagot, MF and Teixeira, MM and Motta, MC and Camargo, EP}, title = {Endosymbiosis in trypanosomatids: the genomic cooperation between bacterium and host in the synthesis of essential amino acids is heavily influenced by multiple horizontal gene transfers.}, journal = {BMC evolutionary biology}, volume = {13}, number = {}, pages = {190}, pmid = {24015778}, issn = {1471-2148}, mesh = {Amino Acids, Essential/*biosynthesis ; Betaproteobacteria/*genetics/physiology ; Biological Evolution ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Phylogeny ; *Symbiosis ; Trypanosomatina/classification/*genetics/metabolism/*microbiology ; }, abstract = {BACKGROUND: Trypanosomatids of the genera Angomonas and Strigomonas live in a mutualistic association characterized by extensive metabolic cooperation with obligate endosymbiotic Betaproteobacteria. However, the role played by the symbiont has been more guessed by indirect means than evidenced. Symbiont-harboring trypanosomatids, in contrast to their counterparts lacking symbionts, exhibit lower nutritional requirements and are autotrophic for essential amino acids. To evidence the symbiont's contributions to this autotrophy, entire genomes of symbionts and trypanosomatids with and without symbionts were sequenced here.<br><br>RESULTS: Analyses of the essential amino acid pathways revealed that most biosynthetic routes are in the symbiont genome. By contrast, the host trypanosomatid genome contains fewer genes, about half of which originated from different bacterial groups, perhaps only one of which (ornithine cyclodeaminase, EC:4.3.1.12) derived from the symbiont. Nutritional, enzymatic, and genomic data were jointly analyzed to construct an integrated view of essential amino acid metabolism in symbiont-harboring trypanosomatids. This comprehensive analysis showed perfect concordance among all these data, and revealed that the symbiont contains genes for enzymes that complete essential biosynthetic routes for the host amino acid production, thus explaining the low requirement for these elements in symbiont-harboring trypanosomatids. Phylogenetic analyses show that the cooperation between symbionts and their hosts is complemented by multiple horizontal gene transfers, from bacterial lineages to trypanosomatids, that occurred several times in the course of their evolution. Transfers occur preferentially in parts of the pathways that are missing from other eukaryotes.<br><br>CONCLUSION: We have herein uncovered the genetic and evolutionary bases of essential amino acid biosynthesis in several trypanosomatids with and without endosymbionts, explaining and complementing decades of experimental results. We uncovered the remarkable plasticity in essential amino acid biosynthesis pathway evolution in these protozoans, demonstrating heavy influence of horizontal gene transfer events, from Bacteria to trypanosomatid nuclei, in the evolution of these pathways.}, }
@article {pmid24013349, year = {2013}, author = {Scheitz, CJ and Guo, Y and Early, AM and Harshman, LG and Clark, AG}, title = {Heritability and inter-population differences in lipid profiles of Drosophila melanogaster.}, journal = {PloS one}, volume = {8}, number = {8}, pages = {e72726}, pmid = {24013349}, issn = {1932-6203}, support = {P20 RR016475/RR/NCRR NIH HHS/United States ; R01 DK074136/DK/NIDDK NIH HHS/United States ; P20 RR16475/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Drosophila melanogaster ; Fatty Acids/*metabolism ; Female ; Lipid Metabolism/*physiology ; Male ; Membrane Fluidity/*physiology ; Species Specificity ; Wolbachia/metabolism ; }, abstract = {Characterizing and understanding the complex spectrum of lipids in higher organisms lags far behind our analysis of genome and transcriptome sequences. Here we generate and evaluate comprehensive lipid profiles (>200 lipids) of 92 inbred lines from five different Drosophila melanogaster populations. We find that the majority of lipid species are highly heritable, and even lipids with odd-chain fatty acids, which cannot be generated by the fly itself, also have high heritabilities. Abundance of the endosymbiont Wolbachia, a potential provider of odd-chained lipids, was positively correlated with this group of lipids. Additionally, we show that despite years of laboratory rearing on the same medium, the lipid profiles of the five geographic populations are sufficiently distinct for population discrimination. Our data predicts a strikingly different membrane fluidity for flies from the Netherlands, which is supported by their increased ethanol tolerance. We find that 18% of lipids show strong concentration differences between males and females. Through an analysis of the correlation structure of the lipid classes, we find modules of co-regulated lipids and begin to associate these with metabolic constraints. Our data provide a foundation for developing associations between variation in lipid composition with variation in other metabolic attributes, with genome-wide variation, and with metrics of health and overall reproductive fitness.}, }
@article {pmid24012312, year = {2013}, author = {Tolleter, D and Seneca, FO and DeNofrio, JC and Krediet, CJ and Palumbi, SR and Pringle, JR and Grossman, AR}, title = {Coral bleaching independent of photosynthetic activity.}, journal = {Current biology : CB}, volume = {23}, number = {18}, pages = {1782-1786}, doi = {10.1016/j.cub.2013.07.041}, pmid = {24012312}, issn = {1879-0445}, mesh = {Animals ; Anthozoa/*physiology ; Chlorophyta/physiology/radiation effects ; Conservation of Natural Resources ; Coral Reefs ; Darkness ; Dinoflagellida/metabolism/*physiology/radiation effects ; *Heat-Shock Response ; Photosynthesis/*physiology ; Reactive Oxygen Species/metabolism ; Sea Anemones/physiology ; }, abstract = {The global decline of reef-building corals is due in part to the loss of algal symbionts, or "bleaching," during the increasingly frequent periods of high seawater temperatures. During bleaching, endosymbiotic dinoflagellate algae (Symbiodinium spp.) either are lost from the animal tissue or lose their photosynthetic pigments, resulting in host mortality if the Symbiodinium populations fail to recover. The >1,000 studies of the causes of heat-induced bleaching have focused overwhelmingly on the consequences of damage to algal photosynthetic processes, and the prevailing model for bleaching invokes a light-dependent generation of toxic reactive oxygen species (ROS) by heat-damaged chloroplasts as the primary trigger. However, the precise mechanisms of bleaching remain unknown, and there is evidence for involvement of multiple cellular processes. In this study, we asked the simple question of whether bleaching can be triggered by heat in the dark, in the absence of photosynthetically derived ROS. We used both the sea anemone model system Aiptasia and several species of reef-building corals to demonstrate that symbiont loss can occur rapidly during heat stress in complete darkness. Furthermore, we observed damage to the photosynthetic apparatus under these conditions in both Aiptasia endosymbionts and cultured Symbiodinium. These results do not directly contradict the view that light-stimulated ROS production is important in bleaching, but they do show that there must be another pathway leading to bleaching. Elucidation of this pathway should help to clarify bleaching mechanisms under the more usual conditions of heat stress in the light.}, }
@article {pmid24008325, year = {2014}, author = {Desirò, A and Salvioli, A and Ngonkeu, EL and Mondo, SJ and Epis, S and Faccio, A and Kaech, A and Pawlowska, TE and Bonfante, P}, title = {Detection of a novel intracellular microbiome hosted in arbuscular mycorrhizal fungi.}, journal = {The ISME journal}, volume = {8}, number = {2}, pages = {257-270}, pmid = {24008325}, issn = {1751-7370}, mesh = {Burkholderiaceae/genetics/*physiology/ultrastructure ; Cytoplasm/*microbiology ; DNA, Ribosomal/genetics ; Glomeromycota/genetics/*physiology/ultrastructure ; In Situ Hybridization, Fluorescence ; Microbiota/genetics/physiology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Mycorrhizae/genetics/*physiology/ultrastructure ; Phylogeny ; Plant Roots/microbiology ; Population Density ; RNA, Ribosomal, 16S/genetics ; Spores, Fungal/physiology ; Symbiosis/*physiology ; Tenericutes/genetics/*physiology/ultrastructure ; }, abstract = {Arbuscular mycorrhizal fungi (AMF) are important members of the plant microbiome. They are obligate biotrophs that colonize the roots of most land plants and enhance host nutrient acquisition. Many AMF themselves harbor endobacteria in their hyphae and spores. Two types of endobacteria are known in Glomeromycota: rod-shaped Gram-negative Candidatus Glomeribacter gigasporarum, CaGg, limited in distribution to members of the Gigasporaceae family, and coccoid Mollicutes-related endobacteria, Mre, widely distributed across different lineages of AMF. The goal of the present study is to investigate the patterns of distribution and coexistence of the two endosymbionts, CaGg and Mre, in spore samples of several strains of Gigaspora margarita. Based on previous observations, we hypothesized that some AMF could host populations of both endobacteria. To test this hypothesis, we performed an extensive investigation of both endosymbionts in G. margarita spores sampled from Cameroonian soils as well as in the Japanese G. margarita MAFF520054 isolate using different approaches (molecular phylotyping, electron microscopy, fluorescence in situ hybridization and quantitative real-time PCR). We found that a single AMF host can harbour both types of endobacteria, with Mre population being more abundant, variable and prone to recombination than the CaGg one. Both endosymbionts seem to retain their genetic and lifestyle peculiarities regardless of whether they colonize the host alone or together. These findings show for the first time that fungi support an intracellular bacterial microbiome, in which distinct types of endobacteria coexist in a single cell.}, }
@article {pmid24002991, year = {2014}, author = {Lashkari, M and Manzari, S and Sahragard, A and Malagnini, V and Boykin, LM and Hosseini, R}, title = {Global genetic variation in the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae) and the endosymbiont Wolbachia: links between Iran and the USA detected.}, journal = {Pest management science}, volume = {70}, number = {7}, pages = {1033-1040}, doi = {10.1002/ps.3643}, pmid = {24002991}, issn = {1526-4998}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Electron Transport Complex IV/genetics ; *Genetic Variation ; Hemiptera/*genetics/*microbiology ; Insect Proteins/genetics ; Iran ; Microsatellite Repeats ; Mitochondrial Proteins/genetics ; Molecular Sequence Data ; Pakistan ; Phylogeny ; Sequence Analysis, DNA ; United States ; Wolbachia/*genetics/*physiology ; }, abstract = {BACKGROUND: The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is one of the most serious pests of citrus in the world, because it transmits the pathogen that causes citrus greening disease. To determine genetic variation among geographic populations of D. citri, microsatellite markers, mitochondrial gene cytochrome oxidase I (mtCOI) and the Wolbachia-Diaphorina, wDi, gene wsp sequence data were used to characterize Iranian and Pakistani populations. Also, a Bayesian phylogenetic technique was utilized to elucidate the relationships among the sequences data in this study and all mtCOI and wsp sequence data available in GenBank and the Wolbachia database.<br><br>RESULTS: Microsatellite markers revealed significant genetic differentiation among Iranian populations, as well as between Iranian and Pakistani populations (FST &#x2009;=&#x2009;0.0428, p&#x2009;<&#x2009;0.01). Within Iran, the Sistan-Baluchestan population is significantly different from the Hormozgan (Fareghan) and Fars populations. By contrast, mtCOI data revealed two polymorphic sites separating the sequences from Iran and Pakistan. Global phylogenetic analyses showed that D.&#x2009;citri populations in Iran, India, Saudi Arabia, Brazil, Mexico, Florida and Texas (USA) are similar. Wolbachia, wDi, wsp sequences were similar among Iranian populations, but different between Iranian and Pakistani populations.<br><br>CONCLUSION: The South West Asia (SWA) group is the most likely source of the introduced Iranian populations of D.&#x2009;citri. This assertion is also supported by the sequence similarity of the Wolbachia, wDi, strains from the Florida, USA and Iranian D.&#x2009;citri. These results should be considered when looking for biological controls in either country.}, }
@article {pmid23999946, year = {2014}, author = {Rillig, MC and Wendt, S and Antonovics, J and Hempel, S and Kohler, J and Wehner, J and Caruso, T}, title = {Interactive effects of root endophytes and arbuscular mycorrhizal fungi on an experimental plant community.}, journal = {Oecologia}, volume = {174}, number = {1}, pages = {263-270}, pmid = {23999946}, issn = {1432-1939}, mesh = {Biomass ; Ecosystem ; Endophytes/*physiology ; Germany ; Mycorrhizae/isolation &amp; purification/*physiology ; Plant Roots/*microbiology ; Plants/microbiology ; *Soil Microbiology ; }, abstract = {Plant-soil microbial interactions have moved into focus as an important mechanism for understanding plant coexistence and composition of communities. Both arbuscular mycorrhizal (AM) as well as other root endophytic fungi co-occur in plant roots, and therefore have the potential to influence relative abundances of plant species in local assemblages. However, no study has experimentally examined how these key root endosymbiont groups might interact and affect plant community composition. Here, using an assemblage of five plant species in mesocosms in a fully factorial experiment, we added an assemblage of AM fungi and/or a mixture of root endophytic fungal isolates, all obtained from the same grassland field site. The results demonstrate that the AM fungi and root endophytes interact to affect plant community composition by changing relative species abundance, and consequently aboveground productivity. Our study highlights the need to explicitly consider interactions of root-inhabiting fungal groups in studies of plant assemblages.}, }
@article {pmid23995941, year = {2013}, author = {Artamonova, II and Mushegian, AR}, title = {Genome sequence analysis indicates that the model eukaryote Nematostella vectensis harbors bacterial consorts.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {22}, pages = {6868-6873}, pmid = {23995941}, issn = {1098-5336}, mesh = {Animals ; Bacteria/genetics/*growth &amp; development ; Computational Biology ; *Genes, Bacterial ; Genome ; Introns ; Phylogeny ; Sea Anemones/*genetics/*microbiology ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {Analysis of the genome sequence of the starlet sea anemone, Nematostella vectensis, reveals many genes whose products are phylogenetically closer to proteins encoded by bacteria or bacteriophages than to any metazoan homologs. One explanation for such sequence affinities could be that these genes have been horizontally transferred from bacteria to the Nematostella lineage. We show, however, that bacterium-like and phage-like genes sequenced by the N. vectensis genome project tend to cluster on separate scaffolds, which typically do not include eukaryotic genes and differ from the latter in their GC contents. Moreover, most of the bacterium-like genes in N. vectensis either lack introns or the introns annotated in such genes are false predictions that, when translated, often restore the missing portions of their predicted protein products. In a freshwater cnidarian, Hydra, for which a proteobacterial endosymbiont is known, these gene features have been used to delineate the DNA of that endosymbiont sampled by the genome sequencing project. We predict that a large fraction of bacterium-like genes identified in the N. vectensis genome similarly are drawn from the contemporary bacterial consorts of the starlet sea anemone. These uncharacterized bacteria associated with N. vectensis are a proteobacterium and a representative of the phylum Bacteroidetes, each represented in the database by an apparently random sample of informational and operational genes. A substantial portion of a putative bacteriophage genome was also detected, which would be especially unlikely to have been transferred to a eukaryote.}, }
@article {pmid23980764, year = {2013}, author = {Thornhill, DJ and Xiang, Y and Pettay, DT and Zhong, M and Santos, SR}, title = {Population genetic data of a model symbiotic cnidarian system reveal remarkable symbiotic specificity and vectored introductions across ocean basins.}, journal = {Molecular ecology}, volume = {22}, number = {17}, pages = {4499-4515}, doi = {10.1111/mec.12416}, pmid = {23980764}, issn = {1365-294X}, mesh = {Animals ; Bayes Theorem ; Coral Reefs ; DNA, Ribosomal Spacer/genetics ; Denaturing Gradient Gel Electrophoresis ; Dinoflagellida/*genetics ; Florida ; Genetic Markers ; Genetic Variation ; *Genetics, Population ; Genotype ; Likelihood Functions ; Microsatellite Repeats ; Molecular Sequence Data ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 18S/genetics ; Sea Anemones/*genetics ; *Symbiosis ; }, abstract = {The Aiptasia-Symbiodinium symbiosis is a promising model for experimental studies of cnidarian-dinoflagellate associations, yet relatively little is known regarding the genetic diversity of either symbiotic partner. To address this, we collected Aiptasia from 16 localities throughout the world and examined the genetic diversity of both anemones and their endosymbionts. Based on newly developed SCAR markers, Aiptasia consisted of two genetically distinct populations: one Aiptasia lineage from Florida and a second network of Aiptasia genotypes found at other localities. These populations did not conform to the distributions of described Aiptasia species, suggesting that taxonomic re-evaluation is needed in the light of molecular genetics. Associations with Symbiodinium further demonstrated the distinctions among Aiptasia populations. According to 18S RFLP, ITS2-DGGE and microsatellite flanker region sequencing, Florida anemones engaged in diverse symbioses predominantly with members of Symbiodinium Clades A and B, but also C, whereas anemones from elsewhere harboured only S. minutum within Clade B. Symbiodinium minutum apparently does not form a stable symbiosis with other hosts, which implies a highly specific symbiosis. Fine-scale differences among S. minutum populations were quantified using six microsatellite loci. Populations of S. minutum had low genotypic diversity and high clonality (R = 0.14). Furthermore, minimal population structure was observed among regions and ocean basins, due to allele and genotype sharing. The lack of genetic structure and low genotypic diversity suggest recent vectoring of Aiptasia and S. minutum across localities. This first ever molecular-genetic study of a globally distributed cnidarian and its Symbiodinium assemblages reveals host-symbiont specificity and widely distributed populations in an important model system.}, }
@article {pmid23979010, year = {2014}, author = {Yamaguchi, H and Nakayama, T and Hongoh, Y and Kawachi, M and Inouye, I}, title = {Molecular diversity of endosymbiotic Nephroselmis (Nephroselmidophyceae) in Hatena arenicola (Katablepharidophycota).}, journal = {Journal of plant research}, volume = {127}, number = {2}, pages = {241-247}, pmid = {23979010}, issn = {1618-0860}, mesh = {Base Sequence ; Chlorophyta/*genetics/physiology ; DNA, Plant/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Eukaryota/*genetics/physiology ; *Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Plastids/genetics ; RNA, Plant/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Hatena arenicola (Katablepharidophycota) is a single-celled eukaryote that temporarily possesses a chlorophyte alga of the genus Nephroselmis as an intracellular symbiont. In the present study, we investigated the molecular diversity of the endosymbiont Nephroselmis in a natural population of the host H. arenicola. We sequenced the host's 18S rRNA gene and the endosymbiont's plastid-encoded 16S rRNA gene. The results indicated that almost identical strains of the host harbored at least three distinct strains of the algal endosymbiont affiliated to the clade Nephroselmis rotunda. This finding supports our previous hypothesis that H. arenicola and its symbiotic alga are in an early stage of secondary endosymbiosis.}, }
@article {pmid23967301, year = {2013}, author = {Burns, JH and Gregg, TM and Takabayashi, M}, title = {Does coral disease affect symbiodinium? Investigating the impacts of growth anomaly on symbiont photophysiology.}, journal = {PloS one}, volume = {8}, number = {8}, pages = {e72466}, pmid = {23967301}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*growth &amp; development ; Circadian Rhythm ; Dinoflagellida/genetics/*metabolism ; Genotype ; *Photosynthesis ; *Symbiosis ; }, abstract = {Growth anomaly (GA) is a commonly observed coral disease that impairs biological functions of the affected tissue. GA is prevalent at Wai 'ōpae tide pools, southeast Hawai 'i Island. Here two distinct forms of this disease, Type A and Type B, affect the coral, Montiporacapitata. While the effects of GA on biology and ecology of the coral host are beginning to be understood, the impact of this disease on the photophysiology of the dinoflagellate symbiont, Symbiodinium spp., has not been investigated. The GA clearly alters coral tissue structure and skeletal morphology and density. These tissue and skeletal changes are likely to modify not only the light micro-environment of the coral tissue, which has a direct impact on the photosynthetic potential of Symbiodinium spp., but also the physiological interactions within the symbiosis. This study utilized Pulse amplitude modulation fluorometry (PAM) to characterize the photophysiology of healthy and GA-affected M. capitata tissue. Overall, endosymbionts within GA-affected tissue exhibit reduced photochemical efficiency. Values of both Fv/Fm and ΔF/ Fm' were significantly lower (p<0.01) in GA tissue compared to healthy and unaffected tissues. Tracking the photophysiology of symbionts over a diurnal time period enabled a comparison of symbiont responses to photosynthetically available radiation (PAR) among tissue conditions. Symbionts within GA tissue exhibited the lowest values of ΔF/Fm' as well as the highest pressure over photosystem II (p<0.01). This study provides evidence that the symbionts within GA-affected tissue are photochemically compromised compared to those residing in healthy tissue.}, }
@article {pmid23961308, year = {2013}, author = {Stackebrandt, E and Zeytun, A and Lapidus, A and Nolan, M and Lucas, S and Hammon, N and Deshpande, S and Cheng, JF and Tapia, R and Goodwin, LA and Pitluck, S and Liolios, K and Pagani, I and Ivanova, N and Mavromatis, K and Mikhailova, N and Huntemann, M and Pati, A and Chen, A and Palaniappan, K and Chang, YJ and Land, M and Hauser, L and Rohde, M and Pukall, R and Göker, M and Detter, JC and Woyke, T and Bristow, J and Eisen, JA and Markowitz, V and Hugenholtz, P and Kyrpides, NC and Klenk, HP}, title = {Complete genome sequence of Coriobacterium glomerans type strain (PW2(T)) from the midgut of Pyrrhocoris apterus L. (red soldier bug).}, journal = {Standards in genomic sciences}, volume = {8}, number = {1}, pages = {15-25}, pmid = {23961308}, issn = {1944-3277}, abstract = {Coriobacterium glomerans Haas and König 1988, is the only species of the genus Coriobacterium, family Coriobacteriaceae, order Coriobacteriales, phylum Actinobacteria. The bacterium thrives as an endosymbiont of pyrrhocorid bugs, i.e. the red fire bug Pyrrhocoris apterus L. The rationale for sequencing the genome of strain PW2(T) is its endosymbiotic life style which is rare among members of Actinobacteria. Here we describe the features of this symbiont, together with the complete genome sequence and its annotation. This is the first complete genome sequence of a member of the genus Coriobacterium and the sixth member of the order Coriobacteriales for which complete genome sequences are now available. The 2,115,681 bp long single replicon genome with its 1,804 protein-coding and 54 RNA genes is part of the G enomic E ncyclopedia of Bacteria and Archaea project.}, }
@article {pmid23960254, year = {2013}, author = {Comandatore, F and Sassera, D and Montagna, M and Kumar, S and Koutsovoulos, G and Thomas, G and Repton, C and Babayan, SA and Gray, N and Cordaux, R and Darby, A and Makepeace, B and Blaxter, M}, title = {Phylogenomics and analysis of shared genes suggest a single transition to mutualism in Wolbachia of nematodes.}, journal = {Genome biology and evolution}, volume = {5}, number = {9}, pages = {1668-1674}, pmid = {23960254}, issn = {1759-6653}, support = {095831//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Genome, Bacterial ; Genomics ; Host-Pathogen Interactions/*genetics ; Humans ; Nematoda/*microbiology ; *Phylogeny ; Symbiosis/genetics ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Wolbachia, endosymbiotic bacteria of the order Rickettsiales, are widespread in arthropods but also present in nematodes. In arthropods, A and B supergroup Wolbachia are generally associated with distortion of host reproduction. In filarial nematodes, including some human parasites, multiple lines of experimental evidence indicate that C and D supergroup Wolbachia are essential for the survival of the host, and here the symbiotic relationship is considered mutualistic. The origin of this mutualistic endosymbiosis is of interest for both basic and applied reasons: How does a parasite become a mutualist? Could intervention in the mutualism aid in treatment of human disease? Correct rooting and high-quality resolution of Wolbachia relationships are required to resolve this question. However, because of the large genetic distance between Wolbachia and the nearest outgroups, and the limited number of genomes so far available for large-scale analyses, current phylogenies do not provide robust answers. We therefore sequenced the genome of the D supergroup Wolbachia endosymbiont of Litomosoides sigmodontis, revisited the selection of loci for phylogenomic analyses, and performed a phylogenomic analysis including available complete genomes (from isolates in supergroups A, B, C, and D). Using 90 orthologous genes with reliable phylogenetic signals, we obtained a robust phylogenetic reconstruction, including a highly supported root to the Wolbachia phylogeny between a (A + B) clade and a (C + D) clade. Although we currently lack data from several Wolbachia supergroups, notably F, our analysis supports a model wherein the putatively mutualist endosymbiotic relationship between Wolbachia and nematodes originated from a single transition event.}, }
@article {pmid23955860, year = {2013}, author = {Bing, XL and Ruan, YM and Rao, Q and Wang, XW and Liu, SS}, title = {Diversity of secondary endosymbionts among different putative species of the whitefly Bemisia tabaci.}, journal = {Insect science}, volume = {20}, number = {2}, pages = {194-206}, doi = {10.1111/j.1744-7917.2012.01522.x}, pmid = {23955860}, issn = {1744-7917}, mesh = {Animals ; *Bacteria/genetics ; *Bacterial Physiological Phenomena ; *Biodiversity ; Evolution, Molecular ; Hemiptera/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {Endosymbionts are important components of arthropod biology. The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a cryptic species complex composed of ≥ 28 putative species. In addition to the primary endosymbiont Portiera aleyrodidarum, six secondary endosymbionts (S-endosymbionts), Hamiltonella, Rickettsia, Wolbachia, Cardinium, Arsenophonus and Fritschea, have been identified in B. tabaci thus far. Here, we tested five of the six S-endosymbiont lineages (excluding Fritschea) from 340 whitely individuals representing six putative species from China. Hamiltonella was detected only in the two exotic invaders, Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED). Rickettsia was absent in Asia II 1 and MED, scarce in Asia II 3 (13%), but abundant in Asia II 7 (63.2%), China 1 (84.7%) and MEAM1 (100%). Wolbachia, Cardinium and Arsenophonus were absent in the invasive MEAM1 and MED but mostly abundant in the native putative species. Furthermore, phylogenetic analyses revealed that some S-endosymbionts have several clades and different B. tabaci putative species can harbor different clades of a given S-endosymbiont, demonstrating further the complexity of S-endosymbionts in B. tabaci. All together, our results demonstrate the variation and diversity of S-endosymbionts in different putative species of B. tabaci, especially between invasive and native whiteflies.}, }
@article {pmid23930974, year = {2013}, author = {Edouard, S and Subramanian, G and Lefevre, B and Dos Santos, A and Pouedras, P and Poinsignon, Y and Mediannikov, O and Raoult, D}, title = {Co-infection with Arsenophonus nasoniae and Orientia tsutsugamushi in a traveler.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {13}, number = {8}, pages = {565-571}, doi = {10.1089/vbz.2012.1083}, pmid = {23930974}, issn = {1557-7759}, mesh = {Adult ; Animals ; Antibodies, Bacterial/*blood/immunology ; Antigens, Bacterial/immunology/isolation &amp; purification ; Asia, Southeastern ; Bacterial Proteins/genetics/isolation &amp; purification/metabolism ; Biopsy ; Coinfection ; Enterobacteriaceae/genetics/immunology/*isolation &amp; purification ; Enterobacteriaceae Infections/*complications/diagnosis/microbiology ; Female ; France ; Humans ; Mice ; Mice, Inbred BALB C ; Orientia tsutsugamushi/genetics/immunology/*isolation &amp; purification ; Polymerase Chain Reaction ; Scrub Typhus/*complications/diagnosis/microbiology ; Skin/*microbiology/pathology ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Travel ; }, abstract = {Here we report a case of co-infection with Orientia tsutsugamushi, the causative agent of scrub typhus, and Arsenophonus nasoniae in a woman with a rash and an eschar who returned from a trip to Southeast Asia. A. nasoniae was previously considered to be a secondary insect and tick endosymbiont of unknown pathogenicity in humans. We amplified both O. tsutsugamushi and A. nasoniae DNA from a skin eschar with qPCR, and a seroconversion for O. tsutsugamushi and A. nasoniae was observed with immunofluorescence assays and western blotting for this patient. And we used 2-D western blotting with an A. nasoniae antigen and polyclonal mouse anti-A. nasoniae antibodies produced in our laboratory to detect the specific antigenic A. nasoniae proteins.}, }
@article {pmid23928843, year = {2013}, author = {Pranaw, K and Singh, S and Dutta, D and Singh, N and Sharma, G and Ganguly, S and Kalia, V and Nain, L}, title = {Extracellular novel metalloprotease from Xenorhabdus indica and its potential as an insecticidal agent.}, journal = {Journal of microbiology and biotechnology}, volume = {23}, number = {11}, pages = {1536-1543}, doi = {10.4014/jmb.1306.06062}, pmid = {23928843}, issn = {1738-8872}, mesh = {Animals ; Biological Assay ; Chemical Precipitation ; Chromatography, Ion Exchange ; Culture Media/chemistry ; Electrophoresis, Polyacrylamide Gel ; India ; Insecticides/*isolation &amp; purification/*metabolism ; Lepidoptera/*drug effects/physiology ; Metalloproteases/chemistry/*isolation &amp; purification/*metabolism ; Molecular Weight ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Survival Analysis ; Xenorhabdus/*enzymology/growth &amp; development/isolation &amp; purification ; }, abstract = {Proteases produced by Xenorhabdus are known to play a significant role in virulence leading to insect mortality. The present study was undertaken to purify and characterize protease from Xenorhabdus indica, an endosymbiont of nematode Steinernema thermophilum, and to decipher its role in insect mortality and its efficacy to control Helicoverpa armigera. A set of 10 strains of Xenorhabdus isolated from different regions of India were screened for protease activity on the basis of zone of clearing on gelatin agar plates. One potent strain of Xenorhabdus indica was selected for the production of protease, and the highest production (1,552 U/ml) was observed at 15-18 h of incubation at 28°C in soya casein digest broth. The extracellular protease was purified from culture supernatant using ammonium sulfate precipitation and ion-exchange chromatography. The enzyme was further characterized by SDS-PAGE and zymography, which confirmed the purity of the protein and its molecular mass was found to be ~52 kDa. Further MALDI-TOF/TOF analysis and effect of metal chelating agent 1,10-phenanthrolin study revealed the nature of the purified protease as a secreted alkaline metalloprotease. The bioefficacy of the purified protease was also tested against cotton bollworm (Helicoverpa armigera) and resulted in 67.9 ± 0.64% mortality within one week. This purified protease has the potential to be developed as a natural insecticidal agent against a broad range of agriculturally important insects.}, }
@article {pmid23928417, year = {2013}, author = {Valle, LG}, title = {Consolidating the legacy of J.-F. Manier: new species and records of trichomycetes from France.}, journal = {Mycologia}, volume = {105}, number = {6}, pages = {1607-1617}, doi = {10.3852/13-129}, pmid = {23928417}, issn = {0027-5514}, mesh = {Animals ; France ; Fungi/*classification/genetics/growth &amp; development/*isolation &amp; purification ; Gastrointestinal Tract/microbiology ; Insecta/*microbiology ; Spores, Fungal/classification/genetics/growth &amp; development/*isolation &amp; purification ; }, abstract = {New data about trichomycetes (arthropod-gut endosymbionts) from southern France is documented, including the description of two Harpellales, Legeriosimilis cebennensis from mayfly nymphs (Heptageniidae) and Smittium manierei from Chironomidae larvae. New geographical records from France are provided, including Bojamyces transfuga, Genistellospora homothallica, Lancisporomyces vernalis, Legeriomyces rarus, Orphella catalaunica, O. helicospora, Stachylina pedifer, Smittium hecatei, S. pseudodimorphum and Tectimyces leptophlebiidarum. Most of these records include species with a Mediterranean distribution, reported before from neighboring countries, and a few others are subcosmopolitan.}, }
@article {pmid23926148, year = {2013}, author = {Hackett, SC and Karley, AJ and Bennett, AE}, title = {Unpredicted impacts of insect endosymbionts on interactions between soil organisms, plants and aphids.}, journal = {Proceedings. Biological sciences}, volume = {280}, number = {1768}, pages = {20131275}, pmid = {23926148}, issn = {1471-2954}, mesh = {Animals ; Aphids/*microbiology/physiology ; Biomass ; Ecosystem ; Enterobacteriaceae/*physiology ; Fertility ; Herbivory ; *Soil Microbiology ; Solanum tuberosum/*growth &amp; development ; *Symbiosis ; }, abstract = {Ecologically significant symbiotic associations are frequently studied in isolation, but such studies of two-way interactions cannot always predict the responses of organisms in a community setting. To explore this issue, we adopt a community approach to examine the role of plant-microbial and insect-microbial symbioses in modulating a plant-herbivore interaction. Potato plants were grown under glass in controlled conditions and subjected to feeding from the potato aphid Macrosiphum euphorbiae. By comparing plant growth in sterile, uncultivated and cultivated soils and the performance of M. euphorbiae clones with and without the facultative endosymbiont Hamiltonella defensa, we provide evidence for complex indirect interactions between insect- and plant-microbial systems. Plant biomass responded positively to the live soil treatments, on average increasing by 15% relative to sterile soil, while aphid feeding produced shifts (increases in stem biomass and reductions in stolon biomass) in plant resource allocation irrespective of soil treatment. Aphid fecundity also responded to soil treatment with aphids on sterile soil exhibiting higher fecundities than those in the uncultivated treatment. The relative allocation of biomass to roots was reduced in the presence of aphids harbouring H. defensa compared with plants inoculated with H. defensa-free aphids and aphid-free control plants. This study provides evidence for the potential of plant and insect symbionts to shift the dynamics of plant-herbivore interactions.}, }
@article {pmid23924784, year = {2014}, author = {Nakagawa, S and Shimamura, S and Takaki, Y and Suzuki, Y and Murakami, S and Watanabe, T and Fujiyoshi, S and Mino, S and Sawabe, T and Maeda, T and Makita, H and Nemoto, S and Nishimura, S and Watanabe, H and Watsuji, TO and Takai, K}, title = {Allying with armored snails: the complete genome of gammaproteobacterial endosymbiont.}, journal = {The ISME journal}, volume = {8}, number = {1}, pages = {40-51}, pmid = {23924784}, issn = {1751-7370}, mesh = {Animals ; Carbon Isotopes/metabolism ; DNA Transposable Elements/genetics ; Flagella/genetics ; Gammaproteobacteria/classification/genetics/metabolism/*physiology ; Genetic Variation ; Genome, Bacterial/*genetics ; Hydrothermal Vents ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; Snails/*microbiology ; Symbiosis ; }, abstract = {Deep-sea vents harbor dense populations of various animals that have their specific symbiotic bacteria. Scaly-foot gastropods, which are snails with mineralized scales covering the sides of its foot, have a gammaproteobacterial endosymbiont in their enlarged esophageal glands and diverse epibionts on the surface of their scales. In this study, we report the complete genome sequencing of gammaproteobacterial endosymbiont. The endosymbiont genome displays features consistent with ongoing genome reduction such as large proportions of pseudogenes and insertion elements. The genome encodes functions commonly found in deep-sea vent chemoautotrophs such as sulfur oxidation and carbon fixation. Stable carbon isotope ((13)C)-labeling experiments confirmed the endosymbiont chemoautotrophy. The genome also includes an intact hydrogenase gene cluster that potentially has been horizontally transferred from phylogenetically distant bacteria. Notable findings include the presence and transcription of genes for flagellar assembly, through which proteins are potentially exported from bacterium to the host. Symbionts of snail individuals exhibited extreme genetic homogeneity, showing only two synonymous changes in 19 different genes (13 810 positions in total) determined for 32 individual gastropods collected from a single colony at one time. The extremely low genetic individuality in endosymbionts probably reflects that the stringent symbiont selection by host prevents the random genetic drift in the small population of horizontally transmitted symbiont. This study is the first complete genome analysis of gastropod endosymbiont and offers an opportunity to study genome evolution in a recently evolved endosymbiont.}, }
@article {pmid23924682, year = {2013}, author = {Wamwiri, FN and Alam, U and Thande, PC and Aksoy, E and Ngure, RM and Aksoy, S and Ouma, JO and Murilla, GA}, title = {Wolbachia, Sodalis and trypanosome co-infections in natural populations of Glossina austeni and Glossina pallidipes.}, journal = {Parasites &amp; vectors}, volume = {6}, number = {1}, pages = {232}, pmid = {23924682}, issn = {1756-3305}, support = {R03TW008413/TW/FIC NIH HHS/United States ; D43 TW007391/TW/FIC NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R03 TW008413/TW/FIC NIH HHS/United States ; D43TW007391/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Coinfection/microbiology/parasitology/veterinary ; Enterobacteriaceae/genetics/isolation &amp; purification/*physiology ; Female ; Insect Vectors/microbiology/parasitology/physiology ; Male ; Symbiosis ; Trypanosoma/genetics/isolation &amp; purification/*physiology ; Tsetse Flies/*microbiology/*parasitology/physiology ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {BACKGROUND: Tsetse flies harbor at least three bacterial symbionts: Wigglesworthia glossinidia, Wolbachia pipientis and Sodalis glossinidius. Wigglesworthia and Sodalis reside in the gut in close association with trypanosomes and may influence establishment and development of midgut parasite infections. Wolbachia has been shown to induce reproductive effects in infected tsetse. This study was conducted to determine the prevalence of these endosymbionts in natural populations of G. austeni and G. pallidipes and to assess the degree of concurrent infections with trypanosomes.<br><br>METHODS: Fly samples analyzed originated from Kenyan coastal forests (trapped in 2009-2011) and South African G. austeni collected in 2008. The age structure was estimated by standard methods. G. austeni (n=298) and G. pallidipes (n= 302) were analyzed for infection with Wolbachia and Sodalis using PCR. Trypanosome infection was determined either by microscopic examination of dissected organs or by PCR amplification.<br><br>RESULTS: Overall we observed that G. pallidipes females had a longer lifespan (70 d) than G. austeni (54 d) in natural populations. Wolbachia infections were present in all G. austeni flies analysed, while in contrast, this symbiont was absent from G. pallidipes. The density of Wolbachia infections in the Kenyan G. austeni population was higher than that observed in South African flies. The infection prevalence of Sodalis ranged from 3.7% in G. austeni to about 16% in G. pallidipes. Microscopic examination of midguts revealed an overall trypanosome infection prevalence of 6% (n&#x2009;=&#x2009;235) and 5% (n&#x2009;=&#x2009;552), while evaluation with ITS1 primers indicated a prevalence of about 13% (n&#x2009;=&#x2009;296) and 10% (n&#x2009;=&#x2009;302) in G. austeni and G. pallidipes, respectively. The majority of infections (46%) were with T. congolense. Co-infection with all three organisms was observed at 1% and 3.3% in G. austeni and G. pallidipes, respectively. Eleven out of the thirteen (85%) co-infected flies harboured T. congolense and T. simiae parasites. While the association between trypanosomes and Sodalis infection was statistically significant in G. pallidipes (P&#x2009;=&#x2009;0.0127), the number of co-infected flies was too few for a definite conclusion.<br><br>CONCLUSIONS: The tsetse populations analyzed differed in the prevalence of symbionts, despite being sympatric and therefore exposed to identical environmental factors. The density of infections with Wolbachia also differed between G. austeni populations. There were too few natural co-infections detected with the Sodalis and trypanosomes to suggest extensive inter-relations between these infections in natural populations. We discuss these findings in the context of potential symbiont-mediated control interventions to reduce parasite infections and/or fly populations.}, }
@article {pmid23913434, year = {2013}, author = {Morag, N and Mullens, BA and Gottlieb, Y}, title = {Assessment of survival and body size variation of Culicoides imicola (Diptera: Ceratopogonidae) as functions of "Candidatus Cardinium" (Bacteroidetes) infection status.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {20}, pages = {6260-6263}, pmid = {23913434}, issn = {1098-5336}, mesh = {Animals ; Bacteroidetes/*growth &amp; development ; Biometry ; Body Size ; Ceratopogonidae/anatomy &amp; histology/*microbiology/*physiology ; Survival Analysis ; }, abstract = {"Candidatus Cardinium hertigii" (Bacteroidetes) is a maternally inherited endosymbiont known from several arthropods. Its mechanisms for persistence in host populations are mostly reproductive manipulation, though it has been occasionally reported to improve fitness parameters in several hosts. In Culicoides (Diptera: Ceratopogonidae) biting midges, the prevalence of "Candidatus Cardinium" infection was documented as moderate, with no detectable sex bias. We therefore investigated whether "Candidatus Cardinium" affects important fitness parameters, such as survival and body size, in Culicoides imicola, a dominant vector species. Field-collected midges were trapped and analyzed for survival under different environmental conditions and antibiotic treatment, taking into account "Candidatus Cardinium" infection status and parity status (i.e., parous or nulliparous). Additionally, wing lengths were measured as a proxy parameter for body size and analyzed together with "Candidatus Cardinium" infection data. The findings revealed no difference in survival of Culicoides infected with "Candidatus Cardinium" and that of uninfected midges in both parity states and under all tested conditions: optimal, starvation, heat, and antibiotic treatment. Beyond survival, no wing length difference was found for "Candidatus Cardinium"-infected versus uninfected midges. In aggregate, these findings support our conclusion that "Candidatus Cardinium" does not have an overt effect on the survival and size of adult C. imicola midges. "Candidatus Cardinium" may affect immature stages or may alter adult reproductive performance.}, }
@article {pmid23906981, year = {2013}, author = {Müller, MJ and Dörr, NC and Deprá, M and Schmitz, HJ and Valiati, VH and Valente, VL}, title = {Reevaluating the infection status by the Wolbachia endosymbiont in Drosophila Neotropical species from the willistoni subgroup.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {19}, number = {}, pages = {232-239}, doi = {10.1016/j.meegid.2013.07.022}, pmid = {23906981}, issn = {1567-7257}, mesh = {Animals ; DNA, Bacterial/analysis/genetics ; Drosophila/*genetics/*microbiology ; Female ; Genes, Insect/genetics ; Male ; Minisatellite Repeats/genetics ; Symbiosis/*genetics ; Wolbachia/classification/*genetics/isolation &amp; purification ; }, abstract = {Infections by the endosymbiotic bacterium Wolbachia developed a rapid global expansion within Old World Drosophila species, ultimately infecting also Neotropical species. In this sense, screenings are necessary to characterize new variants of Wolbachia or new hosts, and also in order to map the dynamics of already known infections. In this paper, we performed a double screening approach that combined Dot-blot and PCR techniques in order to reevaluate the infection status by Wolbachia in species from the willistoni subgroup of Drosophila. Genomic DNA from isofemale lines descendent from females collected in the Amazonian Rainforest (n=91) were submitted to Dot-blot, and were positive for Wolbachia, producing a gradient of hybridization signals, suggesting different infection levels, which was further confirmed through quantitative PCR. Samples with a strong signal in the Dot-blot easily amplified in the wsp-PCR, unlike most of the samples with a medium to weak signal. It was possible to molecularly characterize three Drosophila equinoxialis isofemale lines that were found to be infected in a low density by a wMel-like Wolbachia strain, which was also verified in a laboratory line of Drosophila paulistorum Amazonian. We also found Drosophila tropicalis to be infected with the wAu strain and a Drosophila paulistorum Andean-Brazilian semispecies laboratory line to be infected with a wAu-like Wolbachia. Moreover, we observed that all Drosophila willistoni samples tested with the VNTR-141 marker harbor the same Wolbachia variant, wWil, either in populations from the South or the North of Brazil. Horizontal transfer events involving species of Old World immigrants and Neotropical species of the willistoni subgroup are discussed.}, }
@article {pmid23905733, year = {2013}, author = {Singh, ST and Kumar, J and Thomas, A and Ramamurthy, VV and Rajagopal, R}, title = {Detection and localization of Rickettsia sp in mealybug.}, journal = {Environmental entomology}, volume = {42}, number = {4}, pages = {711-716}, doi = {10.1603/EN13032}, pmid = {23905733}, issn = {1938-2936}, mesh = {Animals ; DNA, Bacterial/genetics/metabolism ; Female ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; India ; Introduced Species ; Microbiota ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics/metabolism ; Rickettsia/*genetics/*physiology ; Sequence Homology ; Symbiosis ; }, abstract = {Mealybug, Phenacoccus solenopsis Tinsley, is a sap-sucking hemipteran insect. It is an agricultural pest that is now widely distributed in India. In this study we report the presence of Rickettsia from P. solenopsis. We constructed a 16S rRNA gene library to study the bacterial diversity associated with this insect and we found that all the clones from the library were only of Candidatus Tremblaya phenacola. This study also highlights that the normal protocol adopted to study the bacterial diversity from environmental sample, by preparation of a 16S rRNA gene library, does not work when the bacterial population is highly skewed in favor of one bacteria (primary endosymbiont in this case). Hence, we used bacterial genus specific polymerase chain reaction primers to test the presence of any of the widely known secondary endosymbionts associated with insects. We tested for the presence of Cardinium, Rickettsia, Wolbachia, and Arsenophonus in P. solenopsis collected from 10 different locations across India. Only Rickettsia was detected from four locations while we were not able to find any other bacteria. We confirmed the presence of these bacteria by localizing Rickettsia and the primary endosmbiont, Candidatus Tremblaya sp. to the bacteriocyte of P. solenopsis using fluorescent in situ hybridization.}, }
@article {pmid23903808, year = {2013}, author = {Fichorova, RN and Buck, OR and Yamamoto, HS and Fashemi, T and Dawood, HY and Fashemi, B and Hayes, GR and Beach, DH and Takagi, Y and Delaney, ML and Nibert, ML and Singh, BN and Onderdonk, AB}, title = {The villain team-up or how Trichomonas vaginalis and bacterial vaginosis alter innate immunity in concert.}, journal = {Sexually transmitted infections}, volume = {89}, number = {6}, pages = {460-466}, pmid = {23903808}, issn = {1472-3263}, support = {R01 AI079085/AI/NIAID NIH HHS/United States ; R56 AI091889/AI/NIAID NIH HHS/United States ; 1R56AI091889-01A1/AI/NIAID NIH HHS/United States ; 1RC1AI086788-01/AI/NIAID NIH HHS/United States ; R21 HD054451/HD/NICHD NIH HHS/United States ; RC1 AI086788/AI/NIAID NIH HHS/United States ; 5R01AI079085/AI/NIAID NIH HHS/United States ; R21HD054451/HD/NICHD NIH HHS/United States ; }, mesh = {Bacteria/*immunology/pathogenicity ; Cells, Cultured ; Chemokines/metabolism ; Colony Count, Microbial ; Epithelial Cells/*immunology/microbiology/parasitology ; Female ; Humans ; *Immunity, Innate ; *Microbial Interactions ; Secretory Leukocyte Peptidase Inhibitor/metabolism ; Trichomonas vaginalis/*immunology/pathogenicity ; }, abstract = {OBJECTIVES: Complex interactions of vaginal microorganisms with the genital tract epithelium shape mucosal innate immunity, which holds the key to sexual and reproductive health. Bacterial vaginosis (BV), a microbiome-disturbance syndrome prevalent in reproductive-age women, occurs commonly in concert with trichomoniasis, and both are associated with increased risk of adverse reproductive outcomes and viral infections, largely attributable to inflammation. To investigate the causative relationships among inflammation, BV and trichomoniasis, we established a model of human cervicovaginal epithelial cells colonised by vaginal Lactobacillus isolates, dominant in healthy women, and common BV species (Atopobium vaginae, Gardnerella vaginalis and Prevotella bivia).<br><br>METHODS: Colonised epithelia were infected with Trichomonas vaginalis (TV) or exposed to purified TV virulence factors (membrane lipophosphoglycan (LPG), its ceramide-phosphoinositol-glycan core (CPI-GC) or the endosymbiont Trichomonas vaginalis virus (TVV)), followed by assessment of bacterial colony-forming units, the mucosal anti-inflammatory microbicide secretory leucocyte protease inhibitor (SLPI), and chemokines that drive pro-inflammatory, antigen-presenting and T cells.<br><br>RESULTS: TV reduced colonisation by Lactobacillus but not by BV species, which were found inside epithelial cells. TV increased interleukin (IL)-8 and suppressed SLPI, likely via LPG/CPI-GC, and upregulated IL-8 and RANTES, likely via TVV as suggested by use of purified pathogenic determinants. BV species A vaginae and G vaginalis induced IL-8 and RANTES, and also amplified the pro-inflammatory responses to both LPG/CPI-GC and TVV, whereas P bivia suppressed the TV/TVV-induced chemokines.<br><br>CONCLUSIONS: These molecular host-parasite-endosymbiont-bacteria interactions explain epidemiological associations and suggest a revised paradigm for restoring vaginal immunity and preventing BV/TV-attributable inflammatory sequelae in women.}, }
@article {pmid23872930, year = {2013}, author = {Fan, Y and Wernegreen, JJ}, title = {Can't take the heat: high temperature depletes bacterial endosymbionts of ants.}, journal = {Microbial ecology}, volume = {66}, number = {3}, pages = {727-733}, pmid = {23872930}, issn = {1432-184X}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/*microbiology ; Endophytes/chemistry/genetics/*physiology ; Enterobacteriaceae/chemistry/genetics/*physiology ; Hot Temperature ; Symbiosis ; }, abstract = {Members of the ant tribe Camponotini have coevolved with Blochmannia, an obligate intracellular bacterial mutualist. This endosymbiont lives within host bacteriocyte cells that line the ant midgut, undergoes maternal transmission from host queens to offspring, and contributes to host nutrition via nitrogen recycling and nutrient biosynthesis. While elevated temperature has been shown to disrupt obligate bacterial mutualists of some insects, its impact on the ant-Blochmannia partnership is less clear. Here, we test the effect of heat on the density of Blochmannia in two related Camponotus species in the lab. Transcriptionally active Blochmannia were quantified using RT-qPCR as the ratio of Blochmannia 16S rRNA to ant host elongation factor 1-α transcripts. Our results showed that 4 weeks of heat treatment depleted active Blochmannia by >99 % in minor workers and unmated queens. However, complete elimination of Blochmannia transcripts rarely occurred, even after 16 weeks of heat treatment. Possible mechanisms of observed thermal sensitivity may include extreme AT-richness and related features of Blochmannia genomes, as well as host stress responses. Broadly, the observed depletion of an essential microbial mutualist in heat-treated ants is analogous to the loss of zooanthellae during coral bleaching. While the ecological relevance of Blochmannia's thermal sensitivity is uncertain, our results argue that symbiont dynamics should be part of models predicting how ants and other animals will respond and adapt to a warming climate.}, }
@article {pmid23864562, year = {2013}, author = {Bressan, A and Mulligan, KL}, title = {Localization and morphological variation of three bacteriome-inhabiting symbionts within a planthopper of the genus Oliarus (Hemiptera: Cixiidae).}, journal = {Environmental microbiology reports}, volume = {5}, number = {4}, pages = {499-505}, doi = {10.1111/1758-2229.12051}, pmid = {23864562}, issn = {1758-2229}, mesh = {Animals ; Bacteroidetes/classification/*cytology/*isolation &amp; purification/physiology ; Betaproteobacteria/classification/*cytology/*isolation &amp; purification/physiology ; Denaturing Gradient Gel Electrophoresis ; Female ; Gammaproteobacteria/classification/*cytology/*isolation &amp; purification/physiology ; Gastrointestinal Tract/microbiology ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Microscopy ; Ovary/microbiology ; Symbiosis ; }, abstract = {Many planthoppers of the family Cixiidae (Hemiptera: Fulgoroidea) host three bacteriome-inhabiting bacteria: a gammaproteobacterium: 'Ca.Purcelliella pentastirinorum', a betaproteobacterium: 'Ca. Vidania fulgoroidea', and a member of the bacteroidetes: 'Ca.Sulcia muelleri'. Through light microscopy observations, DGGE PCR and FISH analysis, we examined the morphology and localization of these three endosymbionts within the abdomens of females of the planthopper Oliarus filicicola. Our results indicate a complex distribution and variation in bacterial morphologies. 'Ca. Sulcia muelleri' singularly colonize one pair of bacteriomes and have cells of irregular shape with an average diameter of approximately 4-5 μm. 'Ca.Purcelliella pentastirinorum' bacteria are roughly globular and have an average diameter of approximately 1.5-2 μm in a pair of bacteriomes located near the posterior end of the abdomen, which are surrounded by giant and highly degenerated cells of 'Ca.Vidania fulgoroidea'. In addition, 'Ca.Vidania fulgoroidea' colonizes the 'rectal organ' (sensu Buchner) and the bacterial cells appear as a small, roughly globular with an average diameter of 3 μm; whereas, 'Ca.Purcelliella pentastirinorum' infects an additional two bacteriomes and the bacterial cells appear tightly packed and highly degenerated. All three endosymbionts colocalize in the forming eggs inside the host's ovaries. Based on the abdominal distribution of bacteriomes and bacterial morphologies, we suggest that 'Ca.Vidania fulgoroidea' and 'Ca.Purcelliella pentastirinorum' correspond to the symbionts described by Buchner as the 'x-' and the 'c + d symbiont' respectively.}, }
@article {pmid23847174, year = {2013}, author = {Fabina, NS and Putnam, HM and Franklin, EC and Stat, M and Gates, RD}, title = {Symbiotic specificity, association patterns, and function determine community responses to global changes: defining critical research areas for coral-Symbiodinium symbioses.}, journal = {Global change biology}, volume = {19}, number = {11}, pages = {3306-3316}, doi = {10.1111/gcb.12320}, pmid = {23847174}, issn = {1365-2486}, mesh = {Alveolata/*physiology ; Animals ; Anthozoa/*physiology ; Biodiversity ; Climate Change ; *Models, Biological ; Polynesia ; *Symbiosis ; }, abstract = {Climate change-driven stressors threaten the persistence of coral reefs worldwide. Symbiotic relationships between scleractinian corals and photosynthetic endosymbionts (genus Symbiodinium) are the foundation of reef ecosystems, and these associations are differentially impacted by stress. Here, we couple empirical data from the coral reefs of Moorea, French Polynesia, and a network theoretic modeling approach to evaluate how patterns in coral-Symbiodinium associations influence community stability under climate change. To introduce the effect of climate perturbations, we simulate local 'extinctions' that represent either the loss of coral species or the ability to engage in symbiotic interactions. Community stability is measured by determining the duration and number of species that persist through the simulated extinctions. Our results suggest that four factors greatly increase coral-Symbiodinium community stability in response to global changes: (i) the survival of generalist hosts and symbionts maximizes potential symbiotic unions; (ii) elevated symbiont diversity provides redundant or complementary symbiotic functions; (iii) compatible symbiotic assemblages create the potential for local recolonization; and (iv) the persistence of certain traits associate with symbiotic diversity and redundancy. Symbiodinium may facilitate coral persistence through novel environmental regimes, but this capacity is mediated by symbiotic specificity, association patterns, and the functional performance of the symbionts. Our model-based approach identifies general trends and testable hypotheses in coral-Symbiodinium community responses. Future studies should consider similar methods when community size and/or environmental complexity preclude experimental approaches.}, }
@article {pmid23846301, year = {2013}, author = {Haselkorn, TS and Watts, TD and Markow, TA}, title = {Density dynamics of diverse Spiroplasma strains naturally infecting different species of Drosophila.}, journal = {Fly}, volume = {7}, number = {3}, pages = {204-210}, pmid = {23846301}, issn = {1933-6942}, mesh = {Animals ; Bacterial Infections/genetics ; Drosophila/genetics/*microbiology ; Female ; Male ; Phenotype ; Species Specificity ; Spiroplasma/*pathogenicity ; Symbiosis ; }, abstract = {Facultative heritable bacterial endosymbionts can have dramatic effects on their hosts, ranging from mutualistic to parasitic. Within-host bacterial endosymbiont density plays a critical role in maintenance of a symbiotic relationship, as it can affect levels of vertical transmission and expression of phenotypic effects, both of which influence the infection prevalence in host populations. Species of genus Drosophila are infected with Spiroplasma, whose characterized phenotypic effects range from that of a male-killing reproductive parasite to beneficial defensive endosymbiont. For many strains of Spiroplasma infecting at least 17 species of Drosophila, however, the phenotypic effects are obscure. The infection prevalence of these Spiroplasma vary within and among Drosophila species, and little is known about the within-host density dynamics of these diverse strains. To characterize the patterns of Spiroplasma density variation among Drosophila we used quantitative PCR to assess bacterial titer at various life stages of three species of Drosophila naturally-infected with two different types of Spiroplasma. For naturally infected Drosophila species we found that non-male-killing infections had consistently lower densities than the male-killing infection. The patterns of Spiroplasma titer change during aging varied among Drosophila species infected with different Spiroplasma strains. Bacterial density varied within and among populations of Drosophila, with individuals from the population with the highest prevalence of infection having the highest density. This density variation underscores the complex interaction of Spiroplasma strain and host genetic background in determining endosymbiont density.}, }
@article {pmid23844658, year = {2013}, author = {Schuler, H and Bertheau, C and Egan, SP and Feder, JL and Riegler, M and Schlick-Steiner, BC and Steiner, FM and Johannesen, J and Kern, P and Tuba, K and Lakatos, F and Köppler, K and Arthofer, W and Stauffer, C}, title = {Evidence for a recent horizontal transmission and spatial spread of Wolbachia from endemic Rhagoletis cerasi (Diptera: Tephritidae) to invasive Rhagoletis cingulata in Europe.}, journal = {Molecular ecology}, volume = {22}, number = {15}, pages = {4101-4111}, doi = {10.1111/mec.12362}, pmid = {23844658}, issn = {1365-294X}, mesh = {Animals ; Bacterial Outer Membrane Proteins/*genetics ; Disease Transmission, Infectious ; Electron Transport Complex IV/*genetics ; Genetic Variation ; Genotype ; Multilocus Sequence Typing ; Tephritidae/*microbiology ; Wolbachia/classification/*genetics ; }, abstract = {The widespread occurrence of Wolbachia in arthropods and nematodes suggests that this intracellular, maternally inherited endosymbiont has the ability to cross species boundaries. However, direct evidence for such a horizontal transmission of Wolbachia in nature is scarce. Here, we compare the well-characterized Wolbachia infection of the European cherry fruit fly, Rhagoletis cerasi, with that of the North American eastern cherry fruit fly, Rhagoletis cingulata, recently introduced to Europe. Molecular genetic analysis of Wolbachia based on multilocus sequence typing and the Wolbachia surface protein wsp showed that all R. cingulata individuals are infected with wCin2 identical to wCer2 in R. cerasi. In contrast, wCin1, a strain identical to wCer1 in R. cerasi, was present in several European populations of R. cingulata, but not in any individual from the United States. Surveys of R. cingulata from Germany and Hungary indicated that in some populations, the frequency of wCin1 increased significantly in just a few years with at least two independent horizontal transmission events. This is corroborated by the analysis of the mitochondrial cytochrome oxidase II gene that showed association of wCin1 with two distinct haplotypes in Germany, one of which is also infected with wCin1 in Hungary. In summary, our study provides strong evidence for a very recent inter-specific Wolbachia transmission with a subsequent spatial spread in field populations.}, }
@article {pmid23840485, year = {2013}, author = {Ye, YH and Woolfit, M and Huttley, GA and Rancès, E and Caragata, EP and Popovici, J and O'Neill, SL and McGraw, EA}, title = {Infection with a Virulent Strain of Wolbachia Disrupts Genome Wide-Patterns of Cytosine Methylation in the Mosquito Aedes aegypti.}, journal = {PloS one}, volume = {8}, number = {6}, pages = {e66482}, pmid = {23840485}, issn = {1932-6203}, mesh = {Aedes/genetics/*microbiology ; Animals ; Cytosine/*metabolism ; *DNA Methylation ; Gene Expression ; Genes, Insect ; *Genome ; *Virulence ; Wolbachia/*pathogenicity ; }, abstract = {BACKGROUND: Cytosine methylation is one of several reversible epigenetic modifications of DNA that allow a greater flexibility in the relationship between genotype and phenotype. Methylation in the simplest models dampens gene expression by modifying regions of DNA critical for transcription factor binding. The capacity to methylate DNA is variable in the insects due to diverse histories of gene loss and duplication of DNA methylases. Mosquitoes like Drosophila melanogaster possess only a single methylase, DNMT2.<br><br>DESCRIPTION: Here we characterise the methylome of the mosquito Aedes aegypti and examine its relationship to transcription and test the effects of infection with a virulent strain of the endosymbiont Wolbachia on the stability of methylation patterns.<br><br>CONCLUSION: We see that methylation in the A. aegypti genome is associated with reduced transcription and is most common in the promoters of genes relating to regulation of transcription and metabolism. Similar gene classes are also methylated in aphids and honeybees, suggesting either conservation or convergence of methylation patterns. In addition to this evidence of evolutionary stability, we also show that infection with the virulent wMelPop Wolbachia strain induces additional methylation and demethylation events in the genome. While most of these changes seem random with respect to gene function and have no detected effect on transcription, there does appear to be enrichment of genes associated with membrane function. Given that Wolbachia lives within a membrane-bound vacuole of host origin and retains a large number of genes for transporting host amino acids, inorganic ions and ATP despite a severely reduced genome, these changes might represent an evolved strategy for manipulating the host environments for its own gain. Testing for a direct link between these methylation changes and expression, however, will require study across a broader range of developmental stages and tissues with methods that detect splice variants.}, }
@article {pmid23825950, year = {2013}, author = {Caragata, EP and Rancès, E and Hedges, LM and Gofton, AW and Johnson, KN and O'Neill, SL and McGraw, EA}, title = {Dietary cholesterol modulates pathogen blocking by Wolbachia.}, journal = {PLoS pathogens}, volume = {9}, number = {6}, pages = {e1003459}, pmid = {23825950}, issn = {1553-7374}, mesh = {*Aedes/metabolism/microbiology/virology ; Animals ; Cholesterol/metabolism/*pharmacology ; Dicistroviridae/*metabolism ; Dietary Fats/metabolism/*pharmacology ; Drosophila melanogaster ; Host-Pathogen Interactions/*drug effects/physiology ; Wolbachia/*physiology ; }, abstract = {The bacterial endosymbiont Wolbachia pipientis protects its hosts from a range of pathogens by limiting their ability to form infections inside the insect. This "pathogen blocking" could be explained by innate immune priming by the symbiont, competition for host-derived resources between pathogens and Wolbachia, or the direct modification of the cell or cellular environment by Wolbachia. Recent comparative work in Drosophila and the mosquito Aedes aegypti has shown that an immune response is not required for pathogen blocking, implying that there must be an additional component to the mechanism. Here we have examined the involvement of cholesterol in pathogen blocking using a system of dietary manipulation in Drosophila melanogaster in combination with challenge by Drosophila C virus (DCV), a common fly pathogen. We observed that flies reared on cholesterol-enriched diets infected with the Wolbachia strains wMelPop and wMelCS exhibited reduced pathogen blocking, with viral-induced mortality occurring 2-5 days earlier than flies reared on Standard diet. This shift toward greater virulence in the presence of cholesterol also corresponded to higher viral copy numbers in the host. Interestingly, an increase in dietary cholesterol did not have an effect on Wolbachia density except in one case, but this did not directly affect the strength of pathogen blocking. Our results indicate that host cholesterol levels are involved with the ability of Wolbachia-infected flies to resist DCV infections, suggesting that cholesterol contributes to the underlying mechanism of pathogen blocking.}, }
@article {pmid23822984, year = {2013}, author = {Zheng, W and Rasmussen, U and Zheng, S and Bao, X and Chen, B and Gao, Y and Guan, X and Larsson, J and Bergman, B}, title = {Multiple Modes of Cell Death Discovered in a Prokaryotic (Cyanobacterial) Endosymbiont.}, journal = {PloS one}, volume = {8}, number = {6}, pages = {e66147}, pmid = {23822984}, issn = {1932-6203}, mesh = {*Apoptosis ; Cyanobacteria/*physiology ; Ferns/cytology/*microbiology ; Plant Leaves/microbiology ; Symbiosis/*physiology ; }, abstract = {Programmed cell death (PCD) is a genetically-based cell death mechanism with vital roles in eukaryotes. Although there is limited consensus on similar death mode programs in prokaryotes, emerging evidence suggest that PCD events are operative. Here we present cell death events in a cyanobacterium living endophytically in the fern Azolla microphylla, suggestive of PCD. This symbiosis is characterized by some unique traits such as a synchronized development, a vertical transfer of the cyanobacterium between plant generations, and a highly eroding cyanobacterial genome. A combination of methods was used to identify cell death modes in the cyanobacterium. Light- and electron microscopy analyses showed that the proportion of cells undergoing cell death peaked at 53.6% (average 20%) of the total cell population, depending on the cell type and host developmental stage. Biochemical markers used for early and late programmed cell death events related to apoptosis (Annexin V-EGFP and TUNEL staining assays), together with visualization of cytoskeleton alterations (FITC-phalloidin staining), showed that all cyanobacterial cell categories were affected by cell death. Transmission electron microscopy revealed four modes of cell death: apoptotic-like, autophagic-like, necrotic-like and autolytic-like. Abiotic stresses further enhanced cell death in a dose and time dependent manner. The data also suggest that dynamic changes in the peptidoglycan cell wall layer and in the cytoskeleton distribution patterns may act as markers for the various cell death modes. The presence of a metacaspase homolog (domain p20) further suggests that the death modes are genetically programmed. It is therefore concluded that multiple, likely genetically programmed, cell death modes exist in cyanobacteria, a finding that may be connected with the evolution of cell death in the plant kingdom.}, }
@article {pmid23821151, year = {2013}, author = {Reumann, S}, title = {Biosynthesis of vitamin K1 (phylloquinone) by plant peroxisomes and its integration into signaling molecule synthesis pathways.}, journal = {Sub-cellular biochemistry}, volume = {69}, number = {}, pages = {213-229}, doi = {10.1007/978-94-007-6889-5_12}, pmid = {23821151}, issn = {0306-0225}, mesh = {Coenzyme A Ligases/metabolism ; Diet ; Humans ; Hydro-Lyases/metabolism ; Peroxisomes/*metabolism ; Plant Proteins/metabolism ; Plants/*metabolism ; *Signal Transduction ; Thiolester Hydrolases/metabolism ; Vitamin K 1/*metabolism ; }, abstract = {Vitamin K1 (phylloquinone) is a substituted membrane-anchored naphthoquinone that functions as an essential electron carrier in photosystem I in photosynthetic organisms. While plants can synthesize phylloquinone de novo, humans rely on vitamin K1 uptake from green leafy vegetables as a precursor for the synthesis of its structural derivative, menaquinone-4 (vitamin K2). In vertebrates, menaquinone-4 serves as an enzymatic co-factor that is required for posttranslational protein modification, i.e. the γ-carboxylation of glutamate residues in specific proteins involved in blood coagulation, bone metabolism and vascular biology. Comprehensive knowledge of the subcellular compartmentalization of vitamin K biosynthesis in plants, pathway regulation and its integration in cellular metabolic networks is important to design functional food with elevated vitamin levels and health benefits to human consumers. It had long been assumed that plants obtained all enzymes for phylloquinone biosynthesis from the ancient cyanobacterial endosymbiont and that, upon gene transfer to the nucleus, all biosynthetic enzymes were re-directed to the plastid. This view, however, has been recently challenged by the exclusive localization of the 6th pathway enzyme (MenB/NS) to peroxisomes in Arabidopsis. Soon afterwards, not only the preceding enzyme, acyl-activating enzyme 14 (MenE/AAE14), but also the succeeding thioesterase (DHNAT) were also shown to be peroxisomal. Phylogenetic analysis revealed a heterogeneous evolutionary origin of the peroxisomal enzymes. Phylloquinone biosynthesis reveals several branching points leading to the synthesis of important defence signalling molecules, such as salicylic acid and benzoic acid derivatives. Recent research data demonstrate that, of the two phenylalanine-dependent pathways for benzoic and salicylic acid biosynthesis, the CoA-dependent β-oxidative pathway, which is peroxisomal, is the major route. Hence, peroxisomes emerge as an important cell compartment for the interconnected networks of phylloquinone, benzoic and salicylic acid biosynthesis. Numerous mechanisms to regulate intermediate flux and the fine-tuned inducible production of secondary metabolites, including signalling molecules, await their characterization at the molecular level.}, }
@article {pmid23818959, year = {2013}, author = {Godoy, MS and Castro-Vazquez, A and Vega, IA}, title = {Endosymbiotic and host proteases in the digestive tract of the invasive snail Pomacea canaliculata: diversity, origin and characterization.}, journal = {PloS one}, volume = {8}, number = {6}, pages = {e66689}, pmid = {23818959}, issn = {1932-6203}, mesh = {Animals ; Biocatalysis/drug effects ; Caseins/metabolism ; Electrophoresis, Polyacrylamide Gel ; Gastrointestinal Tract/*enzymology ; Hydrogen-Ion Concentration ; Molecular Weight ; Peptide Hydrolases/chemistry/*metabolism ; Salivary Glands/enzymology ; Serine Proteinase Inhibitors/pharmacology ; Snails/*enzymology ; *Symbiosis ; Temperature ; }, abstract = {Digestive proteases of the digestive tract of the apple snail Pomacea canaliculata were studied. Luminal protease activity was found in the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Several protease bands and their apparent molecular weights were identified in both tissue extracts and luminal contents by gel zymography: (1) a 125 kDa protease in salivary gland extracts and in the crop content; (2) a 30 kDa protease throughout all studied luminal contents and in extracts of the midgut gland and of the endosymbionts isolated from this gland; (3) two proteases of 145 and 198 kDa in the coiled gut content. All these proteases were inhibited by aprotinin, a serine-protease inhibitor, and showed maximum activity between 30°C and 35°C and pH between 8.5 and 9.5. Tissue L-alanine-N-aminopeptidase activity was determined in the wall of the crop, the style sac and the coiled gut and was significantly higher in the coiled gut. Our findings show that protein digestion in P. canaliculata is carried out through a battery of diverse proteases originated from the salivary glands and the endosymbionts lodged in the midgut gland and by proteases of uncertain origin that occur in the coiled gut lumen.}, }
@article {pmid23816604, year = {2013}, author = {Watanabe, S and Borthakur, D and Bressan, A}, title = {Lack of evidence for an interaction between Buchnera GroEL and Banana bunchy top virus (Nanoviridae).}, journal = {Virus research}, volume = {177}, number = {1}, pages = {98-102}, doi = {10.1016/j.virusres.2013.06.002}, pmid = {23816604}, issn = {1872-7492}, mesh = {Animals ; Aphids/*microbiology/virology ; Bacterial Proteins/genetics/*metabolism ; Buchnera/classification/genetics/isolation &amp; purification/*metabolism ; Chaperonin 60/genetics/*metabolism ; Insect Vectors/microbiology/virology ; Musa/*virology ; Nanoviridae/genetics/*metabolism ; Plant Diseases/*virology ; }, abstract = {Circulative plant viruses such as luteovirids and geminiviruses have been shown to bind to GroEL proteins produced by endosymbiotic bacteria harboured within hemipteran vectors. These interactions seem to prevent the degradation of the viral particles in the aphid's haemocoel. Similarly to luteovirids and geminiviruses, Banana bunchy top virus (BBTV), a member of the Nanoviridae family, is transmitted in a persistent, circulative manner and can be detected in the haemolymph of the aphid vector, Pentalonia nigronervosa. To date, it is not known if BBTV can interact with GroEL. In this study, we localised and inferred the phylogeny of a Buchnera aphidicola endosymbiont inhabiting P. nigronervosa. Furthermore, we predicted the 3D structure of Buchnera GroEL and detected the protein in the haemolymph of P. nigronervosa. Interactions were tested using 3 different assays: immunocapture PCR, dot blot, and far-western blot assays; however, none of them showed evidence of a BBTV-GroEL interaction. We concluded that it was unlikely that BBTV interacted with Buchnera GroEL either in vitro or in vivo and we discuss possible alternatives by which BBTV viral particles are able to avoid the process of degradation in the aphid haemocoel.}, }
@article {pmid23802876, year = {2013}, author = {Le Clec'h, W and Raimond, M and Guillot, S and Bouchon, D and Sicard, M}, title = {Horizontal transfers of feminizing versus non-feminizing Wolbachia strains: from harmless passengers to pathogens.}, journal = {Environmental microbiology}, volume = {15}, number = {11}, pages = {2922-2936}, doi = {10.1111/1462-2920.12172}, pmid = {23802876}, issn = {1462-2920}, mesh = {Animals ; Isopoda/classification/*microbiology ; Phenotype ; *Symbiosis ; Virulence/genetics ; Wolbachia/classification/genetics/*pathogenicity ; }, abstract = {The endosymbiont Wolbachia pipientis infects various hosts in which it navigates vertically from mothers to offspring. However, horizontal transfers of Wolbachia can occur between hosts. The virulence of the horizontally acquired Wolbachia can change in the new host as it has been illustrated by the case of the feminizing strain wVulC from the woodlouse Armadillidium vulgare that turns to a pathogen when introduced into Porcellio dilatatus dilatatus. In the present study, we aim to show whether symbiotic traits, such as (i) host sex manipulation and (ii) colonization patterns, which differ between eight isopod Wolbachia strains, are connected to their virulence towards the recipient host P. d. dilatatus. Among the transferred Wolbachia, some feminizing strains gradually differing in feminizing intensity in their native hosts induced different levels of pathogenicity to P. d. dilatatus. Not a single feminizing strain passed vertically with high titres to the next generation. The non-feminizing Wolbachia strains, even if they reached high densities in the host, did not impact host life-history traits and some vertically passed with high titres to the offspring. These results suggest that a potential link between the manners Wolbachia manipulates its native host reproduction, its virulence and its ability to vertically infect the offspring.}, }
@article {pmid23799924, year = {2013}, author = {Zhang, KJ and Zhu, WC and Rong, X and Zhang, YK and Ding, XL and Liu, J and Chen, DS and Du, Y and Hong, XY}, title = {The complete mitochondrial genomes of two rice planthoppers, Nilaparvata lugens and Laodelphax striatellus: conserved genome rearrangement in Delphacidae and discovery of new characteristics of atp8 and tRNA genes.}, journal = {BMC genomics}, volume = {14}, number = {}, pages = {417}, pmid = {23799924}, issn = {1471-2164}, mesh = {Animals ; Base Composition ; Conserved Sequence/*genetics ; DNA, Mitochondrial/chemistry/genetics ; Gene Order/genetics ; Gene Rearrangement/*genetics ; Genes, Mitochondrial/genetics ; Genome, Mitochondrial/*genetics ; *Genomics ; Hemiptera/enzymology/*genetics ; Mitochondrial Proton-Translocating ATPases/*genetics ; Molecular Sequence Data ; RNA, Transfer/*genetics ; Regulatory Sequences, Nucleic Acid/genetics ; Species Specificity ; }, abstract = {BACKGROUND: Nilaparvata lugens (the brown planthopper, BPH) and Laodelphax striatellus (the small brown planthopper, SBPH) are two of the most important pests of rice. Up to now, there was only one mitochondrial genome of rice planthopper has been sequenced and very few dependable information of mitochondria could be used for research on population genetics, phylogeographics and phylogenetic evolution of these pests. To get more valuable information from the mitochondria, we sequenced the complete mitochondrial genomes of BPH and SBPH. These two planthoppers were infected with two different functional Wolbachia (intracellular endosymbiont) strains (wLug and wStri). Since both mitochondria and Wolbachia are transmitted by cytoplasmic inheritance and it was difficult to separate them when purified the Wolbachia particles, concomitantly sequencing the genome of Wolbachia using next generation sequencing method, we also got nearly complete mitochondrial genome sequences of these two rice planthoppers. After gap closing, we present high quality and reliable complete mitochondrial genomes of these two planthoppers.<br><br>RESULTS: The mitogenomes of N. lugens (BPH) and L. striatellus (SBPH) are 17, 619 bp and 16, 431 bp long with A + T contents of 76.95% and 77.17%, respectively. Both species have typical circular mitochondrial genomes that encode the complete set of 37 genes which are usually found in metazoans. However, the BPH mitogenome also possesses two additional copies of the trnC gene. In both mitochondrial genomes, the lengths of the atp8 gene were conspicuously shorter than that of all other known insect mitochondrial genomes (99 bp for BPH, 102 bp for SBPH). That two rearrangement regions (trnC-trnW and nad6-trnP-trnT) of mitochondrial genomes differing from other known insect were found in these two distantly related planthoppers revealed that the gene order of mitochondria might be conservative in Delphacidae. The large non-coding fragment (the A+T-rich region) putatively corresponding responsible for the control of replication and transcription of mitochondria contained a variable number of tandem repeats (VNTRs) block in different natural individuals of these two planthoppers. Comparison with a previously sequenced individual of SBPH revealed that the mitochondrial genetic variation within a species exists not only in the sequence and secondary structure of genes, but also in the gene order (the different location of trnH gene).<br><br>CONCLUSION: The mitochondrial genome arrangement pattern found in planthoppers was involved in rearrangements of both tRNA genes and protein-coding genes (PCGs). Different species from different genera of Delphacidae possessing the same mitochondrial gene rearrangement suggests that gene rearrangements of mitochondrial genome probably occurred before the differentiation of this family. After comparatively analyzing the gene order of different species of Hemiptera, we propose that except for some specific taxonomical group (e.g. the whiteflies) the gene order might have diversified in family level of this order. The VNTRs detected in the control region might provide additional genetic markers for studying population genetics, individual difference and phylogeographics of planthoppers.}, }
@article {pmid23791183, year = {2013}, author = {Husnik, F and Nikoh, N and Koga, R and Ross, L and Duncan, RP and Fujie, M and Tanaka, M and Satoh, N and Bachtrog, D and Wilson, AC and von Dohlen, CD and Fukatsu, T and McCutcheon, JP}, title = {Horizontal gene transfer from diverse bacteria to an insect genome enables a tripartite nested mealybug symbiosis.}, journal = {Cell}, volume = {153}, number = {7}, pages = {1567-1578}, doi = {10.1016/j.cell.2013.05.040}, pmid = {23791183}, issn = {1097-4172}, support = {R01GM076007/GM/NIGMS NIH HHS/United States ; R01GM093182/GM/NIGMS NIH HHS/United States ; R01 GM076007/GM/NIGMS NIH HHS/United States ; R01 GM093182/GM/NIGMS NIH HHS/United States ; R01 GM101255/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/biosynthesis ; Animals ; Bacteria/classification/*genetics ; Betaproteobacteria/*genetics ; Gene Expression Profiling ; *Gene Transfer, Horizontal ; Hemiptera/*genetics/*microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; }, abstract = {The smallest reported bacterial genome belongs to Tremblaya princeps, a symbiont of Planococcus citri mealybugs (PCIT). Tremblaya PCIT not only has a 139 kb genome, but possesses its own bacterial endosymbiont, Moranella endobia. Genome and transcriptome sequencing, including genome sequencing from a Tremblaya lineage lacking intracellular bacteria, reveals that the extreme genomic degeneracy of Tremblaya PCIT likely resulted from acquiring Moranella as an endosymbiont. In addition, at least 22 expressed horizontally transferred genes from multiple diverse bacteria to the mealybug genome likely complement missing symbiont genes. However, none of these horizontally transferred genes are from Tremblaya, showing that genome reduction in this symbiont has not been enabled by gene transfer to the host nucleus. Our results thus indicate that the functioning of this three-way symbiosis is dependent on genes from at least six lineages of organisms and reveal a path to intimate endosymbiosis distinct from that followed by organelles.}, }
@article {pmid23785288, year = {2013}, author = {Agrawal, S and Chung, DW and Ponts, N and van Dooren, GG and Prudhomme, J and Brooks, CF and Rodrigues, EM and Tan, JC and Ferdig, MT and Striepen, B and Le Roch, KG}, title = {An apicoplast localized ubiquitylation system is required for the import of nuclear-encoded plastid proteins.}, journal = {PLoS pathogens}, volume = {9}, number = {6}, pages = {e1003426}, pmid = {23785288}, issn = {1553-7374}, support = {R01 AI064671/AI/NIAID NIH HHS/United States ; AI 64671/AI/NIAID NIH HHS/United States ; }, mesh = {Cell Line ; Chloroplast Proteins/genetics/*metabolism ; Endoplasmic Reticulum-Associated Degradation/*physiology ; Humans ; Plasmodium falciparum/genetics/*metabolism ; Proteasome Endopeptidase Complex/genetics/metabolism ; Protein Transport/physiology ; Protozoan Proteins/genetics/*metabolism ; Toxoplasma/genetics/*metabolism ; Ubiquitination/*physiology ; }, abstract = {Apicomplexan parasites are responsible for numerous important human diseases including toxoplasmosis, cryptosporidiosis, and most importantly malaria. There is a constant need for new antimalarials, and one of most keenly pursued drug targets is an ancient algal endosymbiont, the apicoplast. The apicoplast is essential for parasite survival, and several aspects of its metabolism and maintenance have been validated as targets of anti-parasitic drug treatment. Most apicoplast proteins are nuclear encoded and have to be imported into the organelle. Recently, a protein translocon typically required for endoplasmic reticulum associated protein degradation (ERAD) has been proposed to act in apicoplast protein import. Here, we show ubiquitylation to be a conserved and essential component of this process. We identify apicoplast localized ubiquitin activating, conjugating and ligating enzymes in Toxoplasma gondii and Plasmodium falciparum and observe biochemical activity by in vitro reconstitution. Using conditional gene ablation and complementation analysis we link this activity to apicoplast protein import and parasite survival. Our studies suggest ubiquitylation to be a mechanistic requirement of apicoplast protein import independent to the proteasomal degradation pathway.}, }
@article {pmid23783810, year = {2013}, author = {Kliot, A and Ghanim, M}, title = {The role of bacterial chaperones in the circulative transmission of plant viruses by insect vectors.}, journal = {Viruses}, volume = {5}, number = {6}, pages = {1516-1535}, pmid = {23783810}, issn = {1999-4915}, mesh = {Animals ; Bacterial Proteins/*metabolism ; Begomovirus/*isolation &amp; purification/physiology ; Chaperonin 60/*metabolism ; Hemiptera ; Host-Pathogen Interactions ; Insect Vectors/*microbiology/*virology ; Luteoviridae/*isolation &amp; purification/physiology ; Molecular Chaperones/*metabolism ; }, abstract = {Persistent circulative transmission of plant viruses involves complex interactions between the transmitted virus and its insect vector. Several studies have shown that insect vector proteins are involved in the passage and the transmission of the virus. Interestingly, proteins expressed by bacterial endosymbionts that reside in the insect vector, were also shown to influence the transmission of these viruses. Thus far, the transmission of two plant viruses that belong to different virus genera was shown to be facilitated by a bacterial chaperone protein called GroEL. This protein was shown to be implicated in the transmission of Potato leafroll virus (PLRV) by the green peach aphid Myzus persicae, and the transmission of Tomato yellow leaf curl virus (TYLCV) by the sweetpotato whitefly Bemisia tabaci. These tri-trophic levels of interactions and their possible evolutionary implications are reviewed.}, }
@article {pmid23781067, year = {2013}, author = {Kleiner, M and Young, JC and Shah, M and VerBerkmoes, NC and Dubilier, N}, title = {Metaproteomics reveals abundant transposase expression in mutualistic endosymbionts.}, journal = {mBio}, volume = {4}, number = {3}, pages = {e00223-13}, pmid = {23781067}, issn = {2150-7511}, mesh = {Animals ; Bacteria/*enzymology ; *Bacterial Physiological Phenomena ; Bacterial Proteins/biosynthesis ; Gene Expression ; Metagenomics/methods ; Oligochaeta/*microbiology ; Proteome/*analysis ; Proteomics/methods ; *Symbiosis ; Transposases/*biosynthesis ; }, abstract = {Transposases, enzymes that catalyze the movement of mobile genetic elements, are the most abundant genes in nature. While many bacteria encode an abundance of transposases in their genomes, the current paradigm is that the expression of transposase genes is tightly regulated and generally low due to its severe mutagenic effects. In the current study, we detected the highest number of transposase proteins ever reported in bacteria, in symbionts of the gutless marine worm Olavius algarvensis with metaproteomics. At least 26 different transposases from 12 different families were detected, and genomic and proteomic analyses suggest that many of these are active. This high expression of transposases indicates that the mechanisms for their tight regulation have been disabled or no longer exist.}, }
@article {pmid23776247, year = {2013}, author = {Shih, PM and Matzke, NJ}, title = {Primary endosymbiosis events date to the later Proterozoic with cross-calibrated phylogenetic dating of duplicated ATPase proteins.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, number = {30}, pages = {12355-12360}, pmid = {23776247}, issn = {1091-6490}, support = {//Howard Hughes Medical Institute/United States ; }, mesh = {Adenosine Triphosphatases/classification/*metabolism ; Calibration ; *Phylogeny ; *Symbiosis ; }, abstract = {Chloroplasts and mitochondria descended from bacterial ancestors, but the dating of these primary endosymbiosis events remains very uncertain, despite their importance for our understanding of the evolution of both bacteria and eukaryotes. All phylogenetic dating in the Proterozoic and before is difficult: Significant debates surround potential fossil calibration points based on the interpretation of the Precambrian microbial fossil record, and strict molecular clock methods cannot be expected to yield accurate dates over such vast timescales because of strong heterogeneity in rates. Even with more sophisticated relaxed-clock analyses, nodes that are distant from fossil calibrations will have a very high uncertainty in dating. However, endosymbiosis events and gene duplications provide some additional information that has never been exploited in dating; namely, that certain nodes on a gene tree must represent the same events, and thus must have the same or very similar dates, even if the exact date is uncertain. We devised techniques to exploit this information: cross-calibration, in which node date calibrations are reused across a phylogeny, and cross-bracing, in which node date calibrations are formally linked in a hierarchical Bayesian model. We apply these methods to proteins with ancient duplications that have remained associated and originated from plastid and mitochondrial endosymbionts: the α and β subunits of ATP synthase and its relatives, and the elongation factor thermo unstable. The methods yield reductions in dating uncertainty of 14-26% while only using date calibrations derived from phylogenetically unambiguous Phanerozoic fossils of multicellular plants and animals. Our results suggest that primary plastid endosymbiosis occurred ∼900 Mya and mitochondrial endosymbiosis occurred ∼1,200 Mya.}, }
@article {pmid23770905, year = {2013}, author = {Ishii, Y and Matsuura, Y and Kakizawa, S and Nikoh, N and Fukatsu, T}, title = {Diversity of bacterial endosymbionts associated with Macrosteles leafhoppers vectoring phytopathogenic phytoplasmas.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {16}, pages = {5013-5022}, pmid = {23770905}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*genetics/metabolism ; Bacterial Physiological Phenomena ; DNA, Bacterial/genetics/metabolism ; Female ; Hemiptera/*microbiology ; Japan ; Male ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics/metabolism ; Sequence Analysis, DNA ; Sequence Homology ; Species Specificity ; Symbiosis ; }, abstract = {Here, we investigate the endosymbiotic microbiota of the Macrosteles leafhoppers M. striifrons and M. sexnotatus, known as vectors of phytopathogenic phytoplasmas. PCR, cloning, sequencing, and phylogenetic analyses of bacterial 16S rRNA genes identified two obligate endosymbionts, "Candidatus Sulcia muelleri" and "Candidatus Nasuia deltocephalinicola," and five facultative endosymbionts, Wolbachia, Rickettsia, Burkholderia, Diplorickettsia, and a novel bacterium belonging to the Rickettsiaceae, from the leafhoppers. "Ca. Sulcia muelleri" and "Ca. Nasuia deltocephalinicola" exhibited 100% infection frequencies in the host species and populations and were separately harbored within different bacteriocytes that constituted a pair of coherent bacteriomes in the abdomen of the host insects, as in other deltocephaline leafhoppers. Wolbachia, Rickettsia, Burkholderia, Diplorickettsia, and the novel Rickettsiaceae bacterium exhibited infection frequencies at 7%, 31%, 12%, 0%, and 24% in M. striifrons and at 20%, 0%, 0%, 20%, and 0% in M. sexnotatus, respectively. Although undetected in the above analyses, phytoplasma infections were detected in 16% of M. striifrons and 60% of M. sexnotatus insects by nested PCR of 16S rRNA genes. Two genetically distinct phytoplasmas, namely, "Candidatus Phytoplasma asteris," associated with aster yellows and related plant diseases, and "Candidatus Phytoplasma oryzae," associated with rice yellow dwarf disease, were identified from the leafhoppers. These results highlight strikingly complex endosymbiotic microbiota of the Macrosteles leafhoppers and suggest ecological interactions between the obligate endosymbionts, the facultative endosymbionts, and the phytopathogenic phytoplasmas within the same host insects, which may affect vector competence of the leafhoppers.}, }
@article {pmid23762518, year = {2013}, author = {Stat, M and Pochon, X and Franklin, EC and Bruno, JF and Casey, KS and Selig, ER and Gates, RD}, title = {The distribution of the thermally tolerant symbiont lineage (Symbiodinium clade D) in corals from Hawaii: correlations with host and the history of ocean thermal stress.}, journal = {Ecology and evolution}, volume = {3}, number = {5}, pages = {1317-1329}, pmid = {23762518}, issn = {2045-7758}, abstract = {Spatially intimate symbioses, such as those between scleractinian corals and unicellular algae belonging to the genus Symbiodinium, can potentially adapt to changes in the environment by altering the taxonomic composition of their endosymbiont communities. We quantified the spatial relationship between the cumulative frequency of thermal stress anomalies (TSAs) and the taxonomic composition of Symbiodinium in the corals Montipora capitata, Porites lobata, and Porites compressa across the Hawaiian archipelago. Specifically, we investigated whether thermally tolerant clade D Symbiodinium was in greater abundance in corals from sites with high frequencies of TSAs. We recovered 2305 Symbiodinium ITS2 sequences from 242 coral colonies in lagoonal reef habitats at Pearl and Hermes Atoll, French Frigate Shoals, and Kaneohe Bay, Oahu in 2007. Sequences were grouped into 26 operational taxonomic units (OTUs) with 12 OTUs associated with Montipora and 21 with Porites. Both coral genera associated with Symbiodinium in clade C, and these co-occurred with clade D in M. capitata and clade G in P. lobata. The latter represents the first report of clade G Symbiodinium in P. lobata. In M. capitata (but not Porites spp.), there was a significant correlation between the presence of Symbiodinium in clade D and a thermal history characterized by high cumulative frequency of TSAs. The endogenous community composition of Symbiodinium and an association with clade D symbionts after long-term thermal disturbance appear strongly dependent on the taxa of the coral host.}, }
@article {pmid23759724, year = {2013}, author = {Duron, O}, title = {Lateral transfers of insertion sequences between Wolbachia, Cardinium and Rickettsia bacterial endosymbionts.}, journal = {Heredity}, volume = {111}, number = {4}, pages = {330-337}, pmid = {23759724}, issn = {1365-2540}, mesh = {Animals ; Arthropods/genetics/microbiology ; Bacteria/genetics ; DNA Transposable Elements/*genetics ; Evolution, Molecular ; Gene Transfer, Horizontal/*genetics ; Molecular Sequence Data ; Phylogeny ; Rickettsia/*genetics ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Various bacteria live exclusively within arthropod cells and collectively act as an important driver of arthropod evolutionary ecology. Whereas rampant intra-generic DNA transfers were recently shown to have a pivotal role in the evolution of the most common of these endosymbionts, Wolbachia, the present study show that inter-generic DNA transfers also commonly take place, constituting a potent source of rapid genomic change. Bioinformatic, molecular and phylogenetic data provide evidence that a selfish genetic element, the insertion sequence ISRpe1, is widespread in the Wolbachia, Cardinium and Rickettsia endosymbionts and experiences recent (and likely ongoing) transfers over long evolutionary distances. Although many ISRpe1 copies were clearly expanding and leading to rapid endosymbiont diversification, degraded copies are also frequently found, constituting an unusual genomic fossil record suggestive of ancient ISRpe1 expansions. Overall, the present data highlight how ecological connections within the arthropod intracellular environment facilitate lateral DNA transfers between distantly related bacterial lineages.}, }
@article {pmid23755311, year = {2013}, author = {Bian, G and Zhou, G and Lu, P and Xi, Z}, title = {Replacing a native Wolbachia with a novel strain results in an increase in endosymbiont load and resistance to dengue virus in a mosquito vector.}, journal = {PLoS neglected tropical diseases}, volume = {7}, number = {6}, pages = {e2250}, pmid = {23755311}, issn = {1935-2735}, support = {R01 AI080597/AI/NIAID NIH HHS/United States ; R01 AI-080597/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*microbiology/*virology ; Animal Structures/virology ; Animals ; Bacterial Load ; Dengue Virus/*growth &amp; development/*isolation &amp; purification ; *Disease Vectors ; Microbial Interactions ; Viral Load ; Wolbachia/*growth &amp; development ; }, abstract = {Wolbachia is a maternally transmitted endosymbiotic bacterium that is estimated to infect up to 65% of insect species. The ability of Wolbachia to both induce pathogen interference and spread into mosquito vector populations makes it possible to develop Wolbachia as a biological control agent for vector-borne disease control. Although Wolbachia induces resistance to dengue virus (DENV), filarial worms, and Plasmodium in mosquitoes, species like Aedes polynesiensis and Aedes albopictus, which carry native Wolbachia infections, are able to transmit dengue and filariasis. In a previous study, the native wPolA in Ae. polynesiensis was replaced with wAlbB from Ae. albopictus, and resulted in the generation of the transinfected "MTB" strain with low susceptibility for filarial worms. In this study, we compare the dynamics of DENV serotype 2 (DENV-2) within the wild type "APM" strain and the MTB strain of Ae. polynesiensis by measuring viral infection in the mosquito whole body, midgut, head, and saliva at different time points post infection. The results show that wAlbB can induce a strong resistance to DENV-2 in the MTB mosquito. Evidence also supports that this resistance is related to a dramatic increase in Wolbachia density in the MTB's somatic tissues, including the midgut and salivary gland. Our results suggests that replacement of a native Wolbachia with a novel infection could serve as a strategy for developing a Wolbachia-based approach to target naturally infected insects for vector-borne disease control.}, }
@article {pmid23754817, year = {2013}, author = {Blackstone, NW}, title = {Why did eukaryotes evolve only once? Genetic and energetic aspects of conflict and conflict mediation.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {368}, number = {1622}, pages = {20120266}, pmid = {23754817}, issn = {1471-2970}, mesh = {*Biological Evolution ; *Energy Metabolism ; Eukaryota/*genetics/*physiology ; Genetic Variation ; Genome ; Mitochondria ; }, abstract = {According to multi-level theory, evolutionary transitions require mediating conflicts between lower-level units in favour of the higher-level unit. By this view, the origin of eukaryotes and the origin of multicellularity would seem largely equivalent. Yet, eukaryotes evolved only once in the history of life, whereas multicellular eukaryotes have evolved many times. Examining conflicts between evolutionary units and mechanisms that mediate these conflicts can illuminate these differences. Energy-converting endosymbionts that allow eukaryotes to transcend surface-to-volume constraints also can allocate energy into their own selfish replication. This principal conflict in the origin of eukaryotes can be mediated by genetic or energetic mechanisms. Genome transfer diminishes the heritable variation of the symbiont, but requires the de novo evolution of the protein-import apparatus and was opposed by selection for selfish symbionts. By contrast, metabolic signalling is a shared primitive feature of all cells. Redox state of the cytosol is an emergent feature that cannot be subverted by an individual symbiont. Hypothetical scenarios illustrate how metabolic regulation may have mediated the conflicts inherent at different stages in the origin of eukaryotes. Aspects of metabolic regulation may have subsequently been coopted from within-cell to between-cell pathways, allowing multicellularity to emerge repeatedly.}, }
@article {pmid23754717, year = {2013}, author = {Hamisi, M and Díez, B and Lyimo, T and Ininbergs, K and Bergman, B}, title = {Epiphytic cyanobacteria of the seagrass Cymodocea rotundata: diversity, diel nifH expression and nitrogenase activity.}, journal = {Environmental microbiology reports}, volume = {5}, number = {3}, pages = {367-376}, doi = {10.1111/1758-2229.12031}, pmid = {23754717}, issn = {1758-2229}, mesh = {Acetylene/metabolism ; Alismatales/*microbiology ; Bacterial Proteins/*genetics/metabolism ; Cyanobacteria/classification/enzymology/*genetics ; DNA, Bacterial/classification/*genetics/metabolism ; Ecosystem ; Enzyme Assays ; *Gene Expression Regulation, Bacterial ; Gene Library ; Genetic Variation ; Indian Ocean ; Microbial Consortia/genetics ; Nitrogen Fixation/physiology ; Oxidoreductases/*genetics/metabolism ; Phylogeny ; RNA, Ribosomal, 16S/classification/*genetics/metabolism ; Symbiosis/physiology ; }, abstract = {Seagrasses are photoautotrophic, ecologically important components of many globally widespread coastal ecosystems, in which combined nitrogen may limit their production. We examined the biodiversity and diazotrophic capacity of microbial epiphytes associated with the phyllosphere of the seagrass Cymodocea rotundata of the Western Indian Ocean. Light microscopy, 16S rRNA and nifH gene analysis revealed the dominance of cyanobacteria in the epiphytic microbial community. Most phylotypes were related to free-living uncultured benthic cyanobacteria, while some to cyanobacterial endosymbionts of marine diatoms. Novel and potentially diazotrophic species, some of known pantropical distribution, were also discovered. Significant diel nitrogenase activities (acetylene reduction assay) were recorded (up to 358 ± 232 nmol C2H4 g(-1) of seagrass FW h(-1)). The nifH gene expression patterns showed that heterocystous phylotypes may be the dominant diazotrophs during the day and non-heterocystous at night. These data show that C. rotundata is colonized by diverse diazotrophic cyanobacteria species and suggest that these may be beneficial partners of seagrasses in nitrogen-depleted waters.}, }
@article {pmid23746528, year = {2013}, author = {Ramadas, R and Thattai, M}, title = {New organelles by gene duplication in a biophysical model of eukaryote endomembrane evolution.}, journal = {Biophysical journal}, volume = {104}, number = {11}, pages = {2553-2563}, pmid = {23746528}, issn = {1542-0086}, support = {500103/Z/09/Z//Wellcome Trust/United Kingdom ; }, mesh = {*Biophysical Phenomena ; Cell Membrane/*metabolism ; Eukaryota/*cytology ; *Gene Duplication ; *Models, Biological ; Organelles/*genetics ; }, abstract = {Extant eukaryotic cells have a dynamic traffic network that consists of diverse membrane-bound organelles exchanging matter via vesicles. This endomembrane system arose and diversified during a period characterized by massive expansions of gene families involved in trafficking after the acquisition of a mitochondrial endosymbiont by a prokaryotic host cell >1.8 billion years ago. Here we investigate the mechanistic link between gene duplication and the emergence of new nonendosymbiotic organelles, using a minimal biophysical model of traffic. Our model incorporates membrane-bound compartments, coat proteins and adaptors that drive vesicles to bud and segregate cargo from source compartments, and SNARE proteins and associated factors that cause vesicles to fuse into specific destination compartments. In simulations, arbitrary numbers of compartments with heterogeneous initial compositions segregate into a few compositionally distinct subsets that we term organelles. The global structure of the traffic system (i.e., the number, composition, and connectivity of organelles) is determined completely by local molecular interactions. On evolutionary timescales, duplication of the budding and fusion machinery followed by loss of cross-interactions leads to the emergence of new organelles, with increased molecular specificity being necessary to maintain larger organellar repertoires. These results clarify potential modes of early eukaryotic evolution as well as more recent eukaryotic diversification.}, }
@article {pmid23744038, year = {2013}, author = {Toomey, ME and Panaram, K and Fast, EM and Beatty, C and Frydman, HM}, title = {Evolutionarily conserved Wolbachia-encoded factors control pattern of stem-cell niche tropism in Drosophila ovaries and favor infection.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, number = {26}, pages = {10788-10793}, pmid = {23744038}, issn = {1091-6490}, support = {K22 AI074909/AI/NIAID NIH HHS/United States ; 1K22AI74909-01A1/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics/physiology ; Drosophila/genetics/*microbiology ; Female ; Host-Pathogen Interactions ; Male ; Ovary/cytology/*microbiology ; Ovum/microbiology ; Phylogeny ; Species Specificity ; Stem Cell Niche ; Stem Cells/*microbiology ; Symbiosis ; Wolbachia/*genetics/pathogenicity/*physiology ; }, abstract = {Wolbachia are intracellular bacteria that infect invertebrates at pandemic levels, including insect vectors of devastating infectious diseases. Although Wolbachia are providing novel strategies for the control of several human pathogens, the processes underlying Wolbachia's successful propagation within and across species remain elusive. Wolbachia are mainly vertically transmitted; however, there is also evidence of extensive horizontal transmission. Here, we provide several lines of evidence supporting Wolbachia's targeting of ovarian stem cell niches--referred to as "niche tropism"--as a previously overlooked strategy for Wolbachia thriving in nature. Niche tropism is pervasive in Wolbachia infecting the Drosophila genus, and different patterns of niche tropism are evolutionarily conserved. Phylogenetic analysis, confirmed by hybrid introgression and transinfection experiments, demonstrates that bacterial factors are the major determinants of differential patterns of niche tropism. Furthermore, bacterial load is increased in germ-line cells passing through infected niches, supporting previous suggestions of a contribution of Wolbachia from stem-cell niches toward vertical transmission. These results support the role of stem-cell niches as a key component for the spreading of Wolbachia in the Drosophila genus and provide mechanistic insights into this unique tissue tropism.}, }
@article {pmid23733960, year = {2013}, author = {Zhang, G and Hussain, M and O'Neill, SL and Asgari, S}, title = {Wolbachia uses a host microRNA to regulate transcripts of a methyltransferase, contributing to dengue virus inhibition in Aedes aegypti.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, number = {25}, pages = {10276-10281}, pmid = {23733960}, issn = {1091-6490}, mesh = {Aedes/genetics/*microbiology/*virology ; Animals ; Cell Line ; DNA (Cytosine-5-)-Methyltransferases/*genetics/metabolism ; Dengue/*microbiology/transmission/virology ; Dengue Virus/*genetics/growth &amp; development ; Female ; Gene Expression Regulation, Developmental ; Gene Expression Regulation, Enzymologic ; Insect Vectors/genetics/microbiology/virology ; MicroRNAs/genetics ; Ovary/enzymology/microbiology/virology ; Symbiosis/physiology ; Virus Replication/physiology ; Wolbachia/growth &amp; development/*virology ; }, abstract = {The endosymbiont Wolbachia is common among insects and known for the reproductive manipulations it exerts on hosts as well as inhibition of virus replication in their hosts. Recently, we showed that Wolbachia uses host microRNAs to manipulate host gene expression for its efficient maintenance in the dengue mosquito vector, Aedes aegypti. Cytosine methylation is mediated by a group of proteins called DNA (cytosine-5) methyltransferases, which are structurally and functionally conserved from prokaryotes to eukaryotes. The biological functions of cytosine methylation include host defense, genome stability, gene regulation, developmental promotion of organs, and lifespan regulation. Ae. aegypti has only one DNA methyltransferase gene (AaDnmt2) belonging to the cytosine methyltransferase family 2, which is the most deeply conserved and widely distributed gene among metazoans. Here, we show that in mosquitoes the introduced endosymbiont, Wolbachia, significantly suppresses expression of AaDnmt2, but dengue virus induces expression of AaDnmt2. Interestingly, we found that aae-miR-2940 microRNA, which is exclusively expressed in Wolbachia-infected mosquitoes, down-regulates the expression of AaDnmt2. Reversely, overexpression of AaDnmt2 in mosquito cells led to inhibition of Wolbachia replication, but significantly promoted replication of dengue virus, suggesting a causal link between this Wolbachia manipulation and the blocking of dengue replication in Wolbachia-infected mosquitoes. In addition, our findings provide an explanation for hypomethylation of the genome in Wolbachia-infected Ae. aegypti.}, }
@article {pmid23733469, year = {2013}, author = {Rana, AK and Chandra, S and Siddiqi, MI and Misra-Bhattacharya, S}, title = {Molecular characterization of an rsmD-like rRNA methyltransferase from the Wolbachia endosymbiont of Brugia malayi and antifilarial activity of specific inhibitors of the enzyme.}, journal = {Antimicrobial agents and chemotherapy}, volume = {57}, number = {8}, pages = {3843-3856}, pmid = {23733469}, issn = {1098-6596}, mesh = {Animals ; Brugia malayi/drug effects/genetics/*microbiology ; Cloning, Molecular ; Culicidae ; Disease Models, Animal ; Drug Evaluation, Preclinical ; Enzyme Inhibitors/pharmacology ; Female ; Filaricides/administration &amp; dosage/*pharmacology ; Genes, Bacterial ; Gerbillinae ; Inhibitory Concentration 50 ; Male ; Methyltransferases/*antagonists &amp; inhibitors/genetics/*isolation &amp; purification/metabolism ; Murinae ; Substrate Specificity ; Symbiosis ; Tryptophan/metabolism ; Wolbachia/*enzymology/growth &amp; development ; }, abstract = {The endosymbiotic organism Wolbachia is an attractive antifilarial drug target. Here we report on the cloning and expression of an rsmD-like rRNA methyltransferase from the Wolbachia endosymbiont of Brugia malayi, its molecular properties, and assays for specific inhibitors. The gene was found to be expressed in all the major life stages of B. malayi. The purified enzyme expressed in Escherichia coli was found to be in monomer form in its native state. The activities of the specific inhibitors (heteroaryl compounds) against the enzyme were tested with B. malayi adult and microfilariae for 7 days in vitro at various concentrations, and NSC-659390 proved to be the most potent compound (50% inhibitory concentration [IC50], 0.32 μM), followed by NSC-658343 (IC50, 4.13 μM) and NSC-657589 (IC50, 7.5 μM). On intraperitoneal administration at 5 mg/kg of body weight for 7 days to adult jirds into which B. malayi had been transplanted intraperitoneally, all the compounds killed a significant proportion of the implanted worms. A very similar result was observed in infected mastomys when inhibitors were administered. Docking studies of enzyme and inhibitors and an in vitro tryptophan quenching experiment were also performed to understand the binding mode and affinity. The specific inhibitors of the enzyme showed a higher affinity for the catalytic site of the enzyme than the nonspecific inhibitors and were found to be potent enough to kill the worm (both adults and microfilariae) in vitro as well as in vivo in a matter of days at micromolar concentrations. The findings suggest that these compounds be evaluated against other pathogens possessing a methyltransferase with a DPPY motif and warrant the design and synthesis of more such inhibitors.}, }
@article {pmid23730771, year = {2013}, author = {Yukilevich, R}, title = {Tropics accelerate the evolution of hybrid male sterility in Drosophila.}, journal = {Evolution; international journal of organic evolution}, volume = {67}, number = {6}, pages = {1805-1814}, doi = {10.1111/evo.12056}, pmid = {23730771}, issn = {1558-5646}, mesh = {Animals ; Drosophila/*genetics ; *Evolution, Molecular ; Genetic Speciation ; Hybridization, Genetic ; Infertility, Male/*genetics ; Male ; Reproductive Isolation ; Time Factors ; *Tropical Climate ; }, abstract = {Understanding the evolutionary mechanisms that facilitate speciation and explain global patterns of species diversity has remained a challenge for decades. The most general pattern of species biodiversity is the latitudinal gradient, whereby species richness increases toward the tropics. Although such a global pattern probably has a multitude of causes, recent attention has focused on the hypothesis that speciation and the evolution of reproductive isolation occur faster in the tropics. Here, I tested this prediction using a dataset on premating and postzygotic isolation between recently diverged Drosophila species. Results showed that while the evolution of premating isolation was not greater between tropical Drosophila relative to nontropical species, postzygotic isolation evolved faster in the tropics. In particular, hybrid male sterility was much greater among tropical Drosophila compared to nontropical species pairs of similar genetic age. Several testable explanations for the novel pattern are discussed, including greater role for sterility-inducing bacterial endosymbionts in the tropics and more intense sperm-sperm competition or sperm-egg sexual conflict in the tropics. The results imply that processes of speciation in the tropics may evolve at different rates or may even be somewhat different from those at higher latitudes.}, }
@article {pmid23726053, year = {2013}, author = {Zhao, DX and Zhang, XF and Hong, XY}, title = {Host-symbiont interactions in spider mite Tetranychus truncates doubly infected with Wolbachia and Cardinium.}, journal = {Environmental entomology}, volume = {42}, number = {3}, pages = {445-452}, doi = {10.1603/EN12354}, pmid = {23726053}, issn = {1938-2936}, mesh = {Animals ; Bacteroidetes/*physiology ; China ; Female ; Fertility ; Longevity ; Male ; Reproduction ; *Symbiosis ; Tetranychidae/*microbiology/*physiology ; Wolbachia/*physiology ; }, abstract = {Inherited bacteria Wolbachia, and more recently Cardinium, have received a great deal of attention for their ability to manipulate the reproduction and fitness of their host species. Wolbachia and Cardinium have been found to co-infect the same host species. In this study, both Wolbachia and Cardinium were found to manipulate host reproduction through cytoplasmic incompatibility and to affect the male-biased sex-ratio in the doubly infected spider mite Tetranychus truncates Ehara. We also investigated effects of double infection with Wolbachia and Cardinium on host fecundity and longevity. Results indicated that Wolbachia and Cardinium increased the fecundity of doubly infected females, although no infection effect on host longevity was observed. Our most important finding was that the mating of uninfected mites facilitated the proliferation of Wolbachia and Cardinium in double-infected mites. We discuss the results observed with respect to the spread of bacterial infection in natural populations and the evolution of the endosymbiont-T. truncates symbiosis.}, }
@article {pmid23721879, year = {2013}, author = {Kukat, C and Larsson, NG}, title = {mtDNA makes a U-turn for the mitochondrial nucleoid.}, journal = {Trends in cell biology}, volume = {23}, number = {9}, pages = {457-463}, doi = {10.1016/j.tcb.2013.04.009}, pmid = {23721879}, issn = {1879-3088}, mesh = {Adenosine Triphosphate/genetics/metabolism ; Crystallography, X-Ray ; DNA, Mitochondrial/*genetics ; DNA-Binding Proteins/*chemistry ; Gene Expression Regulation ; Mitochondria/*genetics ; Mitochondrial Proteins/*chemistry ; Oxidative Phosphorylation ; Protein Conformation ; Transcription Factors/*chemistry ; *Transcription Initiation, Genetic ; }, abstract = {Mitochondria contain mtDNA derived from the ancestral endosymbiont genome. Important subunits of the oxidative phosphorylation system, which supplies cells with the energy currency ATP, are encoded by mtDNA. A naked mtDNA molecule is longer than a typical mitochondrion and is therefore compacted in vivo to form a nucleoprotein complex, denoted the mitochondrial nucleoid. Mitochondrial transcription factor A (TFAM) is the main factor packaging mtDNA into nucleoids and is also essential for mtDNA transcription initiation. The crystal structure of TFAM shows that it bends mtDNA in a sharp U-turn, which likely provides the structural basis for its dual functions. Super-resolution imaging studies have revealed that the nucleoid has an average diameter of ∼100nm and frequently contains a single copy of mtDNA. In this review the structure of the mitochondrial nucleoid and its possible regulatory roles in mtDNA expression will be discussed.}, }
@article {pmid23710278, year = {2013}, author = {Su, Q and Zhou, X and Zhang, Y}, title = {Symbiont-mediated functions in insect hosts.}, journal = {Communicative &amp; integrative biology}, volume = {6}, number = {3}, pages = {e23804}, pmid = {23710278}, issn = {1942-0889}, abstract = {The bacterial endosymbionts occur in a diverse array of insect species and are usually rely within the vertical transmission from mothers to offspring. In addition to primary symbionts, plant sap-sucking insects may also harbor several diverse secondary symbionts. Bacterial symbionts play a prominent role in insect nutritional ecology by aiding in digestion of food or supplementing nutrients that insect hosts can't obtain sufficient amounts from a restricted diet of plant phloem. Currently, several other ecologically relevant traits mediated by endosymbionts are being investigated, including defense toward pathogens and parasites, adaption to environment, influences on insect-plant interactions, and impact of population dynamics. Here, we review recent theoretical predictions and experimental observations of these traits mediated by endosymbionts and suggest that clarifying the roles of symbiotic microbes may be important to offer insights for ameliorating pest invasiveness or impact.}, }
@article {pmid23708130, year = {2013}, author = {Fisher, DJ and Fernández, RE and Maurelli, AT}, title = {Chlamydia trachomatis transports NAD via the Npt1 ATP/ADP translocase.}, journal = {Journal of bacteriology}, volume = {195}, number = {15}, pages = {3381-3386}, pmid = {23708130}, issn = {1098-5530}, support = {F32 AI078655/AI/NIAID NIH HHS/United States ; U19 AI084044/AI/NIAID NIH HHS/United States ; F32 AI078655-01/AI/NIAID NIH HHS/United States ; }, mesh = {Bacterial Proteins/genetics/*metabolism ; Chlamydia trachomatis/*enzymology/genetics/*metabolism ; Escherichia coli/genetics/metabolism ; Gene Expression ; Isotope Labeling ; Kinetics ; Membrane Transport Proteins/genetics/*metabolism ; Mitochondrial ADP, ATP Translocases/genetics/*metabolism ; Models, Biological ; NAD/*metabolism ; Phosphorus Radioisotopes/metabolism ; Substrate Specificity ; }, abstract = {Obligate intracellular bacteria comprising the order Chlamydiales lack the ability to synthesize nucleotides de novo and must acquire these essential compounds from the cytosol of the host cell. The environmental protozoan endosymbiont Protochlamydia amoebophila UWE25 encodes five nucleotide transporters with specificities for different nucleotide substrates, including ATP, GTP, CTP, UTP, and NAD. In contrast, the human pathogen Chlamydia trachomatis encodes only two nucleotide transporters, the ATP/ADP translocase C. trachomatis Npt1 (Npt1(Ct)) and the nucleotide uniporter Npt2(Ct), which transports GTP, UTP, CTP, and ATP. The notable absence of a NAD transporter, coupled with the lack of alternative nucleotide transporters on the basis of bioinformatic analysis of multiple C. trachomatis genomes, led us to re-evaluate the previously characterized transport properties of Npt1(Ct). Using [adenylate-(32)P]NAD, we demonstrate that Npt1(Ct) expressed in Escherichia coli enables the transport of NAD with an apparent K(m) and V(max) of 1.7 μM and 5.8 nM mg(-1) h(-1), respectively. The K(m) for NAD transport is comparable to the K(m) for ATP transport of 2.2 μM, as evaluated in this study. Efflux and substrate competition assays demonstrate that NAD is a preferred substrate of Npt1(Ct) compared to ATP. These results suggest that during reductive evolution, the pathogenic chlamydiae lost individual nucleotide transporters, in contrast to their environmental endosymbiont relatives, without compromising their ability to obtain nucleotides from the host cytosol through relaxation of transport specificity. The novel properties of Npt1Ct and its conservation in chlamydiae make it a potential target for the development of antimicrobial compounds and a model for studying the evolution of transport specificity.}, }
@article {pmid23701629, year = {2013}, author = {Tay, ST}, title = {Wolbachia endosymbionts, Rickettsia felis and Bartonella species, in Ctenocephalides felis fleas in a tropical region.}, journal = {Journal of vector ecology : journal of the Society for Vector Ecology}, volume = {38}, number = {1}, pages = {200-202}, doi = {10.1111/j.1948-7134.2013.12030.x}, pmid = {23701629}, issn = {1948-7134}, mesh = {Animals ; Ctenocephalides/*microbiology ; Rickettsia felis/*physiology ; Tropical Climate ; Wolbachia/*physiology ; }, }
@article {pmid23677999, year = {2013}, author = {Kunugi, M and Takabayashi, A and Tanaka, A}, title = {Evolutionary changes in chlorophyllide a oxygenase (CAO) structure contribute to the acquisition of a new light-harvesting complex in micromonas.}, journal = {The Journal of biological chemistry}, volume = {288}, number = {27}, pages = {19330-19341}, pmid = {23677999}, issn = {1083-351X}, mesh = {Amino Acid Motifs ; Arabidopsis/enzymology/genetics ; Chlorophyta/*enzymology/genetics ; *Evolution, Molecular ; Genes, Plant ; Genetic Complementation Test ; *Light-Harvesting Protein Complexes/chemistry/genetics/metabolism ; Mutation ; *Oxygenases/chemistry/genetics/metabolism ; Protein Structure, Tertiary ; }, abstract = {Chlorophyll b is found in photosynthetic prokaryotes and primary and secondary endosymbionts, although their light-harvesting systems are quite different. Chlorophyll b is synthesized from chlorophyll a by chlorophyllide a oxygenase (CAO), which is a Rieske-mononuclear iron oxygenase. Comparison of the amino acid sequences of CAO among photosynthetic organisms elucidated changes in the domain structures of CAO during evolution. However, the evolutionary relationship between the light-harvesting system and the domain structure of CAO remains unclear. To elucidate this relationship, we investigated the CAO structure and the pigment composition of chlorophyll-protein complexes in the prasinophyte Micromonas. The Micromonas CAO is composed of two genes, MpCAO1 and MpCAO2, that possess Rieske and mononuclear iron-binding motifs, respectively. Only when both genes were introduced into the chlorophyll b-less Arabidopsis mutant (ch1-1) was chlorophyll b accumulated, indicating that cooperation between the two subunits is required to synthesize chlorophyll b. Although Micromonas has a characteristic light-harvesting system in which chlorophyll b is incorporated into the core antennas of reaction centers, chlorophyll b was also incorporated into the core antennas of reaction centers of the Arabidopsis transformants that contained the two Micromonas CAO proteins. Based on these results, we discuss the evolutionary relationship between the structures of CAO and light-harvesting systems.}, }
@article {pmid23674611, year = {2013}, author = {Kopp, C and Pernice, M and Domart-Coulon, I and Djediat, C and Spangenberg, JE and Alexander, DT and Hignette, M and Meziane, T and Meibom, A}, title = {Highly dynamic cellular-level response of symbiotic coral to a sudden increase in environmental nitrogen.}, journal = {mBio}, volume = {4}, number = {3}, pages = {e00052-13}, pmid = {23674611}, issn = {2150-7511}, mesh = {Alveolata/chemistry/metabolism/*physiology ; Animals ; Anthozoa/chemistry/*parasitology/*physiology ; Isotope Labeling ; Nitrogen/*metabolism ; Nitrogen Compounds/metabolism ; Nitrogen Isotopes/metabolism ; Organelles/chemistry ; Spectrometry, Mass, Secondary Ion ; *Symbiosis ; }, abstract = {UNLABELLED: Metabolic interactions with endosymbiotic photosynthetic dinoflagellate Symbiodinium spp. are fundamental to reef-building corals (Scleractinia) thriving in nutrient-poor tropical seas. Yet, detailed understanding at the single-cell level of nutrient assimilation, translocation, and utilization within this fundamental symbiosis is lacking. Using pulse-chase (15)N labeling and quantitative ion microprobe isotopic imaging (NanoSIMS; nanoscale secondary-ion mass spectrometry), we visualized these dynamic processes in tissues of the symbiotic coral Pocillopora damicornis at the subcellular level. Assimilation of ammonium, nitrate, and aspartic acid resulted in rapid incorporation of nitrogen into uric acid crystals (after ~45 min), forming temporary N storage sites within the dinoflagellate endosymbionts. Subsequent intracellular remobilization of this metabolite was accompanied by translocation of nitrogenous compounds to the coral host, starting at ~6 h. Within the coral tissue, nitrogen is utilized in specific cellular compartments in all four epithelia, including mucus chambers, Golgi bodies, and vesicles in calicoblastic cells. Our study shows how nitrogen-limited symbiotic corals take advantage of sudden changes in nitrogen availability; this opens new perspectives for functional studies of nutrient storage and remobilization in microbial symbioses in changing reef environments.<br><br>IMPORTANCE: The methodology applied, combining transmission electron microscopy with nanoscale secondary-ion mass spectrometry (NanoSIMS) imaging of coral tissue labeled with stable isotope tracers, allows quantification and submicrometric localization of metabolic fluxes in an intact symbiosis. This study opens the way for investigations of physiological adaptations of symbiotic systems to nutrient availability and for increasing knowledge of global nitrogen and carbon biogeochemical cycling.}, }
@article {pmid23671571, year = {2013}, author = {Bay, LK and Guérécheau, A and Andreakis, N and Ulstrup, KE and Matz, MV}, title = {Gene expression signatures of energetic acclimatisation in the reef building coral Acropora millepora.}, journal = {PloS one}, volume = {8}, number = {5}, pages = {e61736}, pmid = {23671571}, issn = {1932-6203}, mesh = {Acclimatization/*genetics/physiology ; Aldehyde Dehydrogenase/genetics/metabolism ; Animals ; Anthozoa/*genetics/parasitology/physiology ; Carbonic Anhydrases/genetics/metabolism ; Cluster Analysis ; *Coral Reefs ; Diacylglycerol O-Acyltransferase/genetics/metabolism ; Dinoflagellida/metabolism/physiology ; Ecosystem ; Host-Parasite Interactions ; Lipids/biosynthesis ; Photosystem II Protein Complex/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Seawater ; Symbiosis ; *Transcriptome ; }, abstract = {BACKGROUND: Understanding the mechanisms by which natural populations cope with environmental stress is paramount to predict their persistence in the face of escalating anthropogenic impacts. Reef-building corals are increasingly exposed to local and global stressors that alter nutritional status causing reduced fitness and mortality, however, these responses can vary considerably across species and populations.<br><br>We compare the expression of 22 coral host genes in individuals from an inshore and an offshore reef location using quantitative Reverse Transcription-PCR (qRT-PCR) over the course of 26 days following translocation into a shaded, filtered seawater environment. Declines in lipid content and PSII activity of the algal endosymbionts (Symbiodinium ITS-1 type C2) over the course of the experiment indicated that heterotrophic uptake and photosynthesis were limited, creating nutritional deprivation conditions. Regulation of coral host genes involved in metabolism, CO2 transport and oxidative stress could be detected already after five days, whereas PSII activity took twice as long to respond. Opposing expression trajectories of Tgl, which releases fatty acids from the triacylglycerol storage, and Dgat1, which catalyses the formation of triglycerides, indicate that the decline in lipid content can be attributed, at least in part, by mobilisation of triacylglycerol stores. Corals from the inshore location had initially higher lipid content and showed consistently elevated expression levels of two genes involved in metabolism (aldehyde dehydrogenase) and calcification (carbonic anhydrase).<br><br>CONCLUSIONS/SIGNIFICANCE: Coral host gene expression adjusts rapidly upon change in nutritional conditions, and therefore can serve as an early signature of imminent coral stress. Consistent gene expression differences between populations indicate that corals acclimatize and/or adapt to local environments. Our results set the stage for analysis of these processes in natural coral populations, to better understand the responses of coral communities to global climate change and to develop more efficient management strategies.}, }
@article {pmid23671034, year = {2013}, author = {Faria, VG and Sucena, E}, title = {Wolbachia in the Malpighian tubules: evolutionary dead-end or adaptation?.}, journal = {Journal of experimental zoology. Part B, Molecular and developmental evolution}, volume = {320}, number = {4}, pages = {195-199}, doi = {10.1002/jez.b.22498}, pmid = {23671034}, issn = {1552-5015}, mesh = {Adaptation, Physiological/*genetics ; Animals ; *Biological Evolution ; Drosophila/growth &amp; development/microbiology ; Embryonic Development/genetics ; Germ Cells/microbiology ; Malpighian Tubules/cytology/*microbiology ; Symbiosis/genetics ; Wolbachia/*genetics/physiology ; }, abstract = {Facultative endosymbionts, such as Wolbachia, perpetuate by vertical transmission mostly through colonization of the germline during embryogenesis. The remaining Wolbachia inside the embryo are internalized in progenitor cells of the somatic tissue. This perpetuation strategy triggers a cyclic bacterial bottleneck across host generations. However, throughout the host's life history (Drosophila, for example), some somatic tissues such as the Malpighian tubules (MTs) show large numbers of Wolbachia. It is assumed that Wolbachia present in the progenitor cells of the MTs are confined to this somatic tissue, implicitly considering MTs as an evolutionary dead-end for these bacteria. Nevertheless, the fact that bacteria can survive and proliferate inside MTs suggests a different fate as they may access the host's reproductive system and persist in the host population through vertical transmission. Indeed, based on the particular physiological and developmental characteristics of MT, as well as of Wolbachia, we argue the bacteria present in the MTs may constitute a secondary pool of vertically transmitted bacteria. Moreover, somatic pools of Wolbachia capable of reaching the gonads and insure vertical transmission may also provide an interesting element to the elucidation of horizontal transmission mechanisms. Finally, we also speculate that somatic pools of Wolbachia may play an important role in host fitness, namely during viral infections. In brief, we argue that the somatic pools of Wolbachia, with special emphasis on the MT subset, deserve experimental attention as putative players in the physiology and evolution of both bacteria and hosts.}, }
@article {pmid23667233, year = {2013}, author = {Haferkamp, I and Penz, T and Geier, M and Ast, M and Mushak, T and Horn, M and Schmitz-Esser, S}, title = {The endosymbiont Amoebophilus asiaticus encodes an S-adenosylmethionine carrier that compensates for its missing methylation cycle.}, journal = {Journal of bacteriology}, volume = {195}, number = {14}, pages = {3183-3192}, pmid = {23667233}, issn = {1098-5530}, support = {281633/ERC_/European Research Council/International ; P 22703/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Antiporters/genetics/*metabolism ; Bacteroidetes/genetics/*metabolism ; Cloning, Molecular ; Computational Biology ; Escherichia coli/genetics/metabolism ; S-Adenosylhomocysteine/metabolism ; S-Adenosylmethionine/*metabolism ; Substrate Specificity ; }, abstract = {All organisms require S-adenosylmethionine (SAM) as a methyl group donor and cofactor for various biologically important processes. However, certain obligate intracellular parasitic bacteria and also the amoeba symbiont Amoebophilus asiaticus have lost the capacity to synthesize this cofactor and hence rely on its uptake from host cells. Genome analyses revealed that A. asiaticus encodes a putative SAM transporter. The corresponding protein was functionally characterized in Escherichia coli: import studies demonstrated that it is specific for SAM and S-adenosylhomocysteine (SAH), the end product of methylation. SAM transport activity was shown to be highly dependent on the presence of a membrane potential, and by targeted analyses, we obtained direct evidence for a proton-driven SAM/SAH antiport mechanism. Sequence analyses suggest that SAM carriers from Rickettsiales might operate in a similar way, in contrast to chlamydial SAM transporters. SAM/SAH antiport is of high physiological importance, as it allows for compensation for the missing methylation cycle. The identification of a SAM transporter in A. asiaticus belonging to the Bacteroidetes phylum demonstrates that SAM transport is more widely spread than previously assumed and occurs in bacteria belonging to three different phyla (Proteobacteria, Chlamydiae, and Bacteroidetes).}, }
@article {pmid23663140, year = {2013}, author = {Cayetano, L and Vorburger, C}, title = {Genotype-by-genotype specificity remains robust to average temperature variation in an aphid/endosymbiont/parasitoid system.}, journal = {Journal of evolutionary biology}, volume = {26}, number = {7}, pages = {1603-1610}, doi = {10.1111/jeb.12154}, pmid = {23663140}, issn = {1420-9101}, mesh = {Animals ; Aphids/genetics/microbiology/*parasitology ; Genotype ; Host-Parasite Interactions/*genetics ; Proteobacteria/genetics ; Symbiosis/genetics ; Temperature ; Wasps/*genetics ; }, abstract = {Genotype-by-genotype interactions demonstrate the existence of variation upon which selection acts in host-parasite systems at respective resistance and infection loci. These interactions can potentially be modified by environmental factors, which would entail that different genotypes are selected under different environmental conditions. In the current study, we checked for a G × G × E interaction in the context of average temperature and the genotypes of asexual lines of the endoparasitoid wasp Lysiphlebus fabarum and isolates of Hamiltonella defensa, a protective secondary endosymbiont of the wasp's host, the black bean aphid Aphis fabae. We exposed genetically identical aphids harbouring different isolates of H. defensa to three asexual lines of the parasitoid and measured parasitism success under three different temperatures (15, 22 and 29 °C). Although there was clear evidence for increased susceptibility to parasitoids at the highest average temperature and a strong G × G interaction between the host's symbionts and the parasitoids, no modifying effect of temperature, that is, no significant G × G × E interaction, was detected. This robustness of the observed specificity suggests that the relative fitness of different parasitoid genotypes on hosts protected by particular symbionts remains uncomplicated by spatial or temporal variation in temperature, which should facilitate biological control strategies.}, }
@article {pmid23660513, year = {2013}, author = {Wiwatanaratanabutr, I}, title = {Geographic distribution of wolbachial infections in mosquitoes from Thailand.}, journal = {Journal of invertebrate pathology}, volume = {114}, number = {3}, pages = {337-340}, doi = {10.1016/j.jip.2013.04.011}, pmid = {23660513}, issn = {1096-0805}, mesh = {Aedes/microbiology ; Animals ; Culex/microbiology ; Culicidae/*microbiology ; DNA, Bacterial/chemistry ; Geography ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Thailand ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Members of the genus Wolbachia are inherited intracellular bacterial endosymbionts that infect a diverse range of arthropods. Here I report the results of a survey of these endosymbionts in different mosquito species from six geographic regions of Northern, Northeastern, Western, Central, Eastern and Southern Thailand. Using gene amplification assays with wsp and groE gene primers, wolbachiae were detected in 999 mosquitoes representing 28 species of 1622 specimens collected representing 74 species of wild-caught mosquitoes from all regions of Thailand. Results using wsp primers were similar to those using groE primers in all cases. Wolbachiae had not been reported previously from five of the species tested, namely, Aedes lineatopennis, Aedes vexans, Aedes vittatus, Culex pallidothorax and Culex whitmorei. Infections were found in all major disease vector genera except Anopheles. These results indicate that wolbachial infections are distributed throughout many mosquito species in Thailand.}, }
@article {pmid23659851, year = {2013}, author = {Ruiz-Diaz, CP and Toledo-Hernández, C and Sabat, AM and Marcano, M}, title = {Immune response to a pathogen in corals.}, journal = {Journal of theoretical biology}, volume = {332}, number = {}, pages = {141-148}, doi = {10.1016/j.jtbi.2013.04.028}, pmid = {23659851}, issn = {1095-8541}, mesh = {Animals ; Anthozoa/*immunology ; Host-Pathogen Interactions/*immunology ; *Immunity, Humoral ; *Models, Immunological ; Phagocytes/*immunology ; Phagocytosis/*immunology ; }, abstract = {The sea fan coral (Gorgonia ventalina), one of the most abundant gorgonians in the tropical and subtropical Atlantic waters, have suffered several diseases that have diminished its abundance throughout their range. In this study, we present a model that analyzes the capacity of G. ventalina to eradicate a micro-pathogen under three immune responses: strong, moderate, and very weak. The model assumes that: (1) polyps are the main unit of the coral; (2) the population of polyps is homogeneously distributed; and (3) the immune system is activated by a signal. When an endosymbiont exceeds a density threshold, it becomes pathogenic, increasing polyp mortality. As a consequence, the colony emits a signal to its stem cells to differentiate into phagocytic and humoral cells, both of which combat the pathogen. Given a strong immune response, the pathogen is rapidly eradicated by the immune cells, and the coral polyp population returns to an equilibrium state. With a moderate immune response, polyps and pathogen coexist, but the maximum capacity of polyp density is never reached. An immunologically compromised colony offering a weak immune response is unable to stop pathogen growth, and the colony dies. This analysis suggests an alternative explanation for the spatial and temporal variability in disease incidence and mortality, which is based on the strength of the immune system of hosts rather than the virulence of the pathogen.}, }
@article {pmid23658817, year = {2013}, author = {Levas, SJ and Grottoli, AG and Hughes, A and Osburn, CL and Matsui, Y}, title = {Physiological and biogeochemical traits of bleaching and recovery in the mounding species of coral Porites lobata: implications for resilience in mounding corals.}, journal = {PloS one}, volume = {8}, number = {5}, pages = {e63267}, pmid = {23658817}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/metabolism/*physiology ; Conservation of Natural Resources ; *Geology ; *Pigmentation ; }, abstract = {Mounding corals survive bleaching events in greater numbers than branching corals. However, no study to date has determined the underlying physiological and biogeochemical trait(s) that are responsible for mounding coral holobiont resilience to bleaching. Furthermore, the potential of dissolved organic carbon (DOC) as a source of fixed carbon to bleached corals has never been determined. Here, Porites lobata corals were experimentally bleached for 23 days and then allowed to recover for 0, 1, 5, and 11 months. At each recovery interval a suite of analyses were performed to assess their recovery (photosynthesis, respiration, chlorophyll a, energy reserves, tissue biomass, calcification, δ(13)C of the skeletal, δ(13)C, and δ(15)N of the animal host and endosymbiont fractions). Furthermore, at 0 months of recovery, the assimilation of photosynthetically acquired and zooplankton-feeding acquired carbon into the animal host, endosymbiont, skeleton, and coral-mediated DOC were measured via (13)C-pulse-chase labeling. During the first month of recovery, energy reserves and tissue biomass in bleached corals were maintained despite reductions in chlorophyll a, photosynthesis, and the assimilation of photosynthetically fixed carbon. At the same time, P. lobata corals catabolized carbon acquired from zooplankton and seemed to take up DOC as a source of fixed carbon. All variables that were negatively affected by bleaching recovered within 5 to 11 months. Thus, bleaching resilience in the mounding coral P. lobata is driven by its ability to actively catabolize zooplankton-acquired carbon and seemingly utilize DOC as a significant fixed carbon source, facilitating the maintenance of energy reserves and tissue biomass. With the frequency and intensity of bleaching events expected to increase over the next century, coral diversity on future reefs may favor not only mounding morphologies but species like P. lobata, which have the ability to utilize heterotrophic sources of fixed carbon that minimize the impact of bleaching and promote fast recovery.}, }
@article {pmid23634841, year = {2013}, author = {Xi, J and Chen, Y and Nakashima, J and Wang, SM and Chen, R}, title = {Medicago truncatula esn1 defines a genetic locus involved in nodule senescence and symbiotic nitrogen fixation.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {26}, number = {8}, pages = {893-902}, doi = {10.1094/MPMI-02-13-0043-R}, pmid = {23634841}, issn = {0894-0282}, mesh = {Gene Expression Regulation, Plant/*physiology ; Medicago truncatula/genetics/*metabolism ; Mutation ; Nitrogen Fixation/genetics/*physiology ; Plant Proteins/genetics/*metabolism ; Plant Root Nodulation/physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sinorhizobium meliloti/physiology ; Symbiosis/*physiology ; }, abstract = {Symbiotic interaction between Medicago truncatula and Sinorhizobium meliloti results in the formation on the host roots of new organs, nodules, in which biological nitrogen fixation takes place. In infected cells, rhizobia enclosed in a plant-derived membrane, the symbiosome membrane, differentiate to nitrogen-fixing bacteroids. The symbiosome membrane serves as an interface for metabolite and signal exchanges between the host cells and endosymbionts. At some point during symbiosis, symbiosomes and symbiotic cells are disintegrated, resulting in nodule senescence. The regulatory mechanisms that underlie nodule senescence are not fully understood. Using a forward genetics approach, we have uncovered the early senescent nodule 1 (esn1) mutant from an M. truncatula fast neutron-induced mutant collection. Nodules on esn1 roots are spherically shaped, ineffective in nitrogen fixation, and senesce early. Atypical among fixation defective mutants isolated thus far, bacteroid differentiation and expression of nifH, Leghemoglobin, and DNF1 genes are not affected in esn1 nodules, supporting the idea that a process downstream of bacteroid differentiation and nitrogenase gene expression is affected in the esn1 mutant. Expression analysis shows that marker genes involved in senescence, macronutrient degradation, and remobilization are greatly upregulated during nodule development in the esn1 mutant, consistent with a role of ESN1 in nodule senescence and symbiotic nitrogen fixation.}, }
@article {pmid23624672, year = {2013}, author = {Łukasik, P and Dawid, MA and Ferrari, J and Godfray, HC}, title = {The diversity and fitness effects of infection with facultative endosymbionts in the grain aphid, Sitobion avenae.}, journal = {Oecologia}, volume = {173}, number = {3}, pages = {985-996}, pmid = {23624672}, issn = {1432-1939}, support = {BB/E010857/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/*microbiology/*parasitology/physiology ; Enterobacteriaceae/*physiology ; Female ; Fertility/physiology ; Genotype ; Host-Parasite Interactions ; Linear Models ; Oviposition/physiology ; Symbiosis/*physiology ; Wasps/pathogenicity/*physiology ; }, abstract = {Mutualisms with facultative, non-essential heritable microorganisms influence the biology of many insects, and they can have major effects on insect host fitness in certain situations. One of the best-known examples is found in aphids where the facultative endosymbiotic bacterium Hamiltonella defensa confers protection against hymenopterous parasitoids. This symbiont is widely distributed in aphids and related insects, yet its defensive properties have only been tested in two aphid species. In a wild population of the grain aphid, Sitobion avenae, we identified several distinct strains of endosymbiotic bacteria, including Hamiltonella. The symbiont had no consistent effect on grain aphid fecundity, though we did find a significant interaction between aphid genotype by symbiont status. In contrast to findings in other aphid species, Hamiltonella did not reduce aphid susceptibility to two species of parasitoids (Aphidius ervi and Ephedrus plagiator), nor did it affect the fitness of wasps that successfully completed development. Despite this, experienced females of both parasitoid species preferentially oviposited into uninfected hosts when given a choice between genetically identical individuals with or without Hamiltonella. Thus, although Hamiltonella does not always increase resistance to parasitism, it may reduce the risk of parasitism in its aphid hosts by making them less attractive to searching parasitoids.}, }
@article {pmid23614027, year = {2013}, author = {Wulff, JA and Buckman, KA and Wu, K and Heimpel, GE and White, JA}, title = {The endosymbiont Arsenophonus is widespread in soybean aphid, Aphis glycines, but does not provide protection from parasitoids or a fungal pathogen.}, journal = {PloS one}, volume = {8}, number = {4}, pages = {e62145}, pmid = {23614027}, issn = {1932-6203}, mesh = {Animals ; Aphids/*microbiology/*parasitology ; Symbiosis/physiology ; }, abstract = {Aphids commonly harbor bacterial facultative symbionts that have a variety of effects upon their aphid hosts, including defense against hymenopteran parasitoids and fungal pathogens. The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is infected with the symbiont Arsenophonus sp., which has an unknown role in its aphid host. Our research goals were to document the infection frequency and diversity of the symbiont in field-collected soybean aphids, and to determine whether Arsenophonus is defending soybean aphid against natural enemies. We performed diagnostic PCR and sequenced four Arsenophonus genes in soybean aphids from their native and introduced range to estimate infection frequency and genetic diversity, and found that Arsenophonus infection is highly prevalent and genetically uniform. To evaluate the defensive role of Arsenophonus, we cured two aphid genotypes of their natural Arsenophonus infection through ampicillin microinjection, resulting in infected and uninfected isolines within the same genetic background. These isolines were subjected to parasitoid assays using a recently introduced biological control agent, Binodoxys communis [Braconidae], a naturally recruited parasitoid, Aphelinus certus [Aphelinidae], and a commercially available biological control agent, Aphidius colemani [Braconidae]. We also assayed the effect of the common aphid fungal pathogen, Pandora neoaphidis (Remaudiere &amp; Hennebert) Humber (Entomophthorales: Entomophthoraceae), on the same aphid isolines. We did not find differences in successful parasitism for any of the parasitoid species, nor did we find differences in P. neoaphidis infection between our treatments. Our conclusion is that Arsenophonus does not defend its soybean aphid host against these major parasitoid and fungal natural enemies.}, }
@article {pmid23613801, year = {2013}, author = {Boucias, DG and Kariithi, HM and Bourtzis, K and Schneider, DI and Kelley, K and Miller, WJ and Parker, AG and Abd-Alla, AM}, title = {Transgenerational transmission of the Glossina pallidipes hytrosavirus depends on the presence of a functional symbiome.}, journal = {PloS one}, volume = {8}, number = {4}, pages = {e61150}, pmid = {23613801}, issn = {1932-6203}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Ampicillin/pharmacology ; Animals ; Female ; Gram-Negative Bacteria/*physiology ; Insect Viruses/drug effects/*physiology ; Male ; *Symbiosis ; Tsetse Flies/*microbiology/*virology ; Virus Replication/drug effects ; }, abstract = {The vertically transmitted endosymbionts (Sodalis glossinidius and Wigglesworthia glossinidia) of the tsetse fly (Diptera: Glossinidae) are known to supplement dietary deficiencies and modulate the reproductive fitness and the defense system of the fly. Some tsetse fly species are also infected with the bacterium, Wolbachia and with the Glossina hytrosavirus (GpSGHV). Laboratory-bred G. pallidipes exhibit chronic asymptomatic and acute symptomatic GpSGHV infection, with the former being the most common in these colonies. However, under as yet undefined conditions, the asymptomatic state can convert to the symptomatic state, leading to detectable salivary gland hypertrophy (SGH(+)) syndrome. In this study, we investigated the interplay between the bacterial symbiome and GpSGHV during development of G. pallidipes by knocking down the symbionts with antibiotic. Intrahaemocoelic injection of GpSGHV led to high virus titre (10(9) virus copies), but was not accompanied by either the onset of detectable SGH(+), or release of detectable virus particles into the blood meals during feeding events. When the F1 generations of GpSGHV-challenged mothers were dissected within 24 h post-eclosion, SGH(+) was observed to increase from 4.5% in the first larviposition cycle to >95% in the fourth cycle. Despite being sterile, these F1 SGH(+) progeny mated readily. Removal of the tsetse symbiome, however, suppressed transgenerational transfer of the virus via milk secretions and blocked the ability of GpSGHV to infect salivary glands of the F1 progeny. Whereas GpSGHV infects and replicates in salivary glands of developing pupa, the virus is unable to induce SGH(+) within fully differentiated adult salivary glands. The F1 SGH(+) adults are responsible for the GpSGHV-induced colony collapse in tsetse factories. Our data suggest that GpSGHV has co-evolved with the tsetse symbiome and that the symbionts play key roles in the virus transmission from mother to progeny.}, }
@article {pmid23612938, year = {2013}, author = {Stork, S and Lau, J and Moog, D and Maier, UG}, title = {Three old and one new: protein import into red algal-derived plastids surrounded by four membranes.}, journal = {Protoplasma}, volume = {250}, number = {5}, pages = {1013-1023}, pmid = {23612938}, issn = {1615-6102}, mesh = {Biological Evolution ; Plastids/*metabolism ; Protein Transport ; Rhodophyta/*metabolism ; }, abstract = {Engulfment of a red or green alga by another eukaryote and subsequent reduction of the symbiont to an organelle, termed a complex plastid, is a process known as secondary endosymbiosis and is shown in a diverse group of eukaryotic organisms. Important members are heterokontophytes, haptophytes, cryptophytes, and apicomplexan parasites, all of them with complex plastids of red algal origin surrounded by four membranes. Although the evolutionary relationship between these organisms is still debated, they share common mechanisms for plastid protein import. In this review, we describe recent findings and current models on preprotein import into complex plastids with a special focus on the second outermost plastid membrane. Derived from the plasma membrane of the former endosymbiont, the evolution of protein transport across this so-called periplastidal membrane most likely represented the challenge in the transition from an endosymbiont to a host-dependent organelle. Here, remodeling and relocation of the symbiont endoplasmic reticulum-associated degradation (ERAD) machinery gave rise to a translocon complex termed symbiont-specific ERAD-like machinery and provides a fascinating insight into complex cellular evolution.}, }
@article {pmid23610627, year = {2013}, author = {Rosic, NN and Leggat, W and Kaniewska, P and Dove, S and Hoegh-Guldberg, O}, title = {New-old hemoglobin-like proteins of symbiotic dinoflagellates.}, journal = {Ecology and evolution}, volume = {3}, number = {4}, pages = {822-834}, pmid = {23610627}, issn = {2045-7758}, abstract = {Symbiotic dinoflagellates are unicellular photosynthetic algae that live in mutualistic symbioses with many marine organisms. Within the transcriptome of coral endosymbionts Symbiodinium sp. (type C3), we discovered the sequences of two novel and highly polymorphic hemoglobin-like genes and proposed their 3D protein structures. At the protein level, four isoforms shared between 87 and 97% sequence identity for Hb-1 and 78-99% for Hb-2, whereas between Hb-1 and Hb-2 proteins, only 15-21% sequence homology has been preserved. Phylogenetic analyses of the dinoflagellate encoding Hb sequences have revealed a separate evolutionary origin of the discovered globin genes and indicated the possibility of horizontal gene transfer. Transcriptional regulation of the Hb-like genes was studied in the reef-building coral Acropora aspera exposed to elevated temperatures (6-7°C above average sea temperature) over a 24-h period and a 72-h period, as well as to nutrient stress. Exposure to elevated temperatures resulted in an increased Hb-1 gene expression of 31% after 72 h only, whereas transcript abundance of the Hb-2 gene was enhanced by up to 59% by both 1-day and 3-day thermal stress conditions. Nutrient stress also increased gene expression of Hb-2 gene by 70%. Our findings describe the differential expression patterns of two novel Hb genes from symbiotic dinoflagellates and their polymorphic nature. Furthermore, the inducible nature of Hb-2 gene by both thermal and nutrient stressors indicates a prospective role of this form of hemoglobin in the initial coral-algal responses to changes in environmental conditions. This novel hemoglobin has potential use as a stress biomarker.}, }
@article {pmid23609909, year = {2013}, author = {Upadhyaya, CP and Gururani, MA and Prasad, R and Verma, A}, title = {A cell wall extract from Piriformospora indica promotes tuberization in potato (Solanum tuberosum L.) via enhanced expression of Ca(+2) signaling pathway and lipoxygenase gene.}, journal = {Applied biochemistry and biotechnology}, volume = {170}, number = {4}, pages = {743-755}, doi = {10.1007/s12010-013-0231-1}, pmid = {23609909}, issn = {1559-0291}, mesh = {Basidiomycota/*chemistry ; Biological Factors/pharmacology ; Calcium/pharmacology ; *Calcium Signaling ; Cell Wall/*chemistry ; Culture Media/chemistry ; Enzyme Activation ; Gene Expression Regulation, Plant ; Genes, Plant ; Host-Pathogen Interactions ; Lipoxygenase/genetics/metabolism ; Plant Proteins/genetics ; Plant Tubers/*drug effects/enzymology/genetics/growth &amp; development ; RNA, Messenger/genetics/metabolism ; Solanum tuberosum/*drug effects/enzymology/genetics/growth &amp; development ; }, abstract = {Piriformospora indica is an axenically cultivable phytopromotional endosymbiont that mimics capabilities of arbuscular mycorrhizal fungi. This is a basidiomycete of the Sebacinaceae family, which promotes growth, development, and seed production in a variety of plant species. We report that the cell wall extract (CWE) from P. indica induces tuberization in vitro and promotes tuber growth and yield in potato. The CWE altered the calcium signaling pathway that regulates tuberization process. An increase in tuber number and size was correlated with increased transcript expression of the two Ca(2+)-dependant proteins (CaM1 and St-CDPK1) and the lipoxygenase (LOX) mRNA, which are known to play distinct roles in potato tuberization. External supplementation of Ca(2+) ions induced a similar set of tuberization pathway genes, indicating presence of an active Ca(2+) in the CWE of P. indica. Since potato tuberization is directly influenced by the presence of microflora in nature, the present study provides an insight into the novel mechanism of potato tuberization in relation to plant-microbe association. Ours is the first report on an in vitro tuber-inducing beneficial fungus.}, }
@article {pmid23593179, year = {2013}, author = {Le Clec'h, W and Chevalier, FD and Genty, L and Bertaux, J and Bouchon, D and Sicard, M}, title = {Cannibalism and predation as paths for horizontal passage of Wolbachia between terrestrial isopods.}, journal = {PloS one}, volume = {8}, number = {4}, pages = {e60232}, pmid = {23593179}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; *Cannibalism ; DNA Primers ; *Gene Transfer, Horizontal ; In Situ Hybridization, Fluorescence ; Phylogeny ; Polymerase Chain Reaction ; *Predatory Behavior ; Wolbachia/classification/genetics/*physiology ; }, abstract = {The alpha-proteobacteria Wolbachia are the most widespread endosymbionts in arthropods and nematodes. Mainly maternally inherited, these so-called sex parasites have selected several strategies that increase their vertical dispersion in host populations. However, the lack of congruence between the Wolbachia and their host phylogenies suggests frequent horizontal transfers. One way that could be used for horizontal Wolbachia transfers between individuals is predation. The aim of this study was to test whether horizontal passage of Wolbachia is possible when an uninfected terrestrial isopod eats an infected one. After having eaten Armadillidium vulgare harbouring Wolbachia, the predator-recipients (the two woodlice A. vulgare and Porcellio dilatatus dilatatus) that were initially Wolbachia-free were tested positive for the presence of Wolbachia both by quantitative PCR and Fluorescence in situ Hybridization (FISH). Even if the titers were low compared to vertically infected individuals, this constitutes the first demonstration of Wolbachia occurrence in various organs of an initially uninfected host after eating an infected one.}, }
@article {pmid23593012, year = {2013}, author = {Ellegaard, KM and Klasson, L and Näslund, K and Bourtzis, K and Andersson, SG}, title = {Comparative genomics of Wolbachia and the bacterial species concept.}, journal = {PLoS genetics}, volume = {9}, number = {4}, pages = {e1003381}, pmid = {23593012}, issn = {1553-7404}, mesh = {Animals ; *Drosophila/genetics/microbiology ; *Genome, Bacterial ; Genomics ; New Caledonia ; Phylogeny ; Recombination, Genetic ; Sequence Analysis, DNA ; Seychelles ; Species Specificity ; *Symbiosis/genetics/physiology ; *Wolbachia/genetics/physiology ; }, abstract = {The importance of host-specialization to speciation processes in obligate host-associated bacteria is well known, as is also the ability of recombination to generate cohesion in bacterial populations. However, whether divergent strains of highly recombining intracellular bacteria, such as Wolbachia, can maintain their genetic distinctness when infecting the same host is not known. We first developed a protocol for the genome sequencing of uncultivable endosymbionts. Using this method, we have sequenced the complete genomes of the Wolbachia strains wHa and wNo, which occur as natural double infections in Drosophila simulans populations on the Seychelles and in New Caledonia. Taxonomically, wHa belong to supergroup A and wNo to supergroup B. A comparative genomics study including additional strains supported the supergroup classification scheme and revealed 24 and 33 group-specific genes, putatively involved in host-adaptation processes. Recombination frequencies were high for strains of the same supergroup despite different host-preference patterns, leading to genomic cohesion. The inferred recombination fragments for strains of different supergroups were of short sizes, and the genomes of the co-infecting Wolbachia strains wHa and wNo were not more similar to each other and did not share more genes than other A- and B-group strains that infect different hosts. We conclude that Wolbachia strains of supergroup A and B represent genetically distinct clades, and that strains of different supergroups can co-exist in the same arthropod host without converging into the same species. This suggests that the supergroups are irreversibly separated and that barriers other than host-specialization are able to maintain distinct clades in recombining endosymbiont populations. Acquiring a good knowledge of the barriers to genetic exchange in Wolbachia will advance our understanding of how endosymbiont communities are constructed from vertically and horizontally transmitted genes.}, }
@article {pmid23588850, year = {2013}, author = {Martínez-Rodríguez, P and Hernández-Pérez, M and Bella, JL}, title = {Detection of Spiroplasma and Wolbachia in the bacterial gonad community of Chorthippus parallelus.}, journal = {Microbial ecology}, volume = {66}, number = {1}, pages = {211-223}, pmid = {23588850}, issn = {1432-184X}, mesh = {Animals ; Female ; Gonads/microbiology ; Grasshoppers/genetics/*microbiology/*physiology ; Male ; Molecular Sequence Data ; Phylogeny ; Reproduction ; Spiroplasma/classification/genetics/*isolation &amp; purification ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {We have recently detected the endosymbiont Wolbachia in multiple individuals and populations of the grasshopper Chorthippus parallelus (Orthoptera: acrididae). This bacterium induces reproductive anomalies, including cytoplasmic incompatibility. Such incompatibilities may help explain the maintenance of two distinct subspecies of this grasshopper, C. parallelus parallelus and C. parallelus erythropus, which are involved in a Pyrenean hybrid zone that has been extensively studied for the past 20 years, becoming a model system for the study of genetic divergence and speciation. To evaluate whether Wolbachia is the sole bacterial infection that might induce reproductive anomalies, the gonadal bacterial community of individuals from 13 distinct populations of C. parallelus was determined by denaturing gradient gel electrophoresis analysis of bacterial 16S rRNA gene fragments and sequencing. The study revealed low bacterial diversity in the gonads: a persistent bacterial trio consistent with Spiroplasma sp. and the two previously described supergroups of Wolbachia (B and F) dominated the gonad microbiota. A further evaluation of the composition of the gonad bacterial communities was carried out by whole cell hybridization. Our results confirm previous studies of the cytological distribution of Wolbachia in C. parallelus gonads and show a homogeneous infection by Spiroplasma. Spiroplasma and Wolbachia cooccurred in some individuals, but there was no significant association of Spiroplasma with a grasshopper's sex or with Wolbachia infection, although subtle trends might be detected with a larger sample size. This information, together with previous experimental crosses of this grasshopper, suggests that Spiroplasma is unlikely to contribute to sex-specific reproductive anomalies; instead, they implicate Wolbachia as the agent of the observed anomalies in C. parallelus.}, }
@article {pmid23584995, year = {2013}, author = {Mavrianos, J and Berkow, EL and Desai, C and Pandey, A and Batish, M and Rabadi, MJ and Barker, KS and Pain, D and Rogers, PD and Eugenin, EA and Chauhan, N}, title = {Mitochondrial two-component signaling systems in Candida albicans.}, journal = {Eukaryotic cell}, volume = {12}, number = {6}, pages = {913-922}, pmid = {23584995}, issn = {1535-9786}, support = {R01AI058145/AI/NIAID NIH HHS/United States ; R01 MH096625/MH/NIMH NIH HHS/United States ; AG030504/AG/NIA NIH HHS/United States ; MH076679/MH/NIMH NIH HHS/United States ; K01 MH076679/MH/NIMH NIH HHS/United States ; R01 AG030504/AG/NIA NIH HHS/United States ; R01 AI058145/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Apoptosis ; Bacterial Proteins/*genetics/metabolism ; Biological Evolution ; Candida albicans/*genetics/metabolism/ultrastructure ; Fungal Proteins/*genetics/metabolism ; Gene Deletion ; Gene Expression Regulation, Fungal ; Heat-Shock Proteins/deficiency/*genetics ; Histidine Kinase ; Mitochondria/*metabolism/ultrastructure ; Molecular Sequence Data ; Phylogeny ; Protein Kinases/deficiency/*genetics ; Protein Transport ; Recombinant Fusion Proteins/genetics/metabolism ; Sequence Homology, Amino Acid ; *Signal Transduction ; }, abstract = {Two-component signal transduction pathways are one of the primary means by which microorganisms respond to environmental signals. These signaling cascades originated in prokaryotes and were inherited by eukaryotes via endosymbiotic lateral gene transfer from ancestral cyanobacteria. We report here that the nuclear genome of the pathogenic fungus Candida albicans contains elements of a two-component signaling pathway that seem to be targeted to the mitochondria. The C. albicans two-component response regulator protein Srr1 (stress response regulator 1) contains a mitochondrial targeting sequence at the N terminus, and fluorescence microscopy reveals mitochondrial localization of green fluorescent protein-tagged Srr1. Moreover, phylogenetic analysis indicates that C. albicans Srr1 is more closely related to histidine kinases and response regulators found in marine bacteria than are other two-component proteins present in the fungi. These data suggest conservation of this protein during the evolutionary transition from endosymbiont to a subcellular organelle. We used microarray analysis to determine whether the phenotypes observed with a srr1Δ/Δ mutant could be correlated with gene transcriptional changes. The expression of mitochondrial genes was altered in the srr1Δ/Δ null mutant in comparison to their expression in the wild type. Furthermore, apoptosis increased significantly in the srr1Δ/Δ mutant strain compared to the level of apoptosis in the wild type, suggesting the activation of a mitochondrion-dependent apoptotic cell death pathway in the srr1Δ/Δ mutant. Collectively, this study shows for the first time that a lower eukaryote like C. albicans possesses a two-component response regulator protein that has survived in mitochondria and regulates a subset of genes whose functions are associated with the oxidative stress response and programmed cell death (apoptosis).}, }
@article {pmid23583844, year = {2012}, author = {Sohlenkamp, C and Raetz, CR and Ingram, BO}, title = {The calcium-stimulated lipid A 3-O deacylase from Rhizobium etli is not essential for plant nodulation.}, journal = {Biochimica et biophysica acta}, volume = {1831}, number = {7}, pages = {1250-1259}, pmid = {23583844}, issn = {0006-3002}, support = {R01 GM051796/GM/NIGMS NIH HHS/United States ; R37 GM051796/GM/NIGMS NIH HHS/United States ; U54 GM069338/GM/NIGMS NIH HHS/United States ; }, abstract = {The lipid A component of lipopolysaccharide from the nitrogen-fixing plant endosymbiont, Rhizobium etli, is structurally very different from that found in most enteric bacteria. The lipid A from free-living R. etli is structurally heterogeneous and exists as a mixture of species which are either pentaacylated or tetraacylated. In contrast, the lipid A from R. etli bacteroids is reported to consist exclusively of tetraacylated lipid A species. The tetraacylated lipid A species in both cases lack a β-hydroxymyristoyl chain at the 3-position of lipid A. Here, we show that the lipid A modification enzyme responsible for 3-O deacylation in R. etli is a homolog of the PagL protein originally described in Salmonella enterica sv. typhimurium. In contrast to the PagL proteins described from other species, R. etli PagL displays a calcium dependency. To determine the importance of the lipid A modification catalyzed by PagL, we isolated and characterized a R. etli mutant deficient in the pagL gene. Mass spectrometric analysis confirmed that the mutant strain was exclusively tetraacylated and radiochemical analysis revealed that 3-O deacylase activity was absent in membranes prepared from the mutant. The R. etli mutant was not impaired in its ability to form nitrogen-fixing nodules on Phaseolus vulgaris but it displayed slower nodulation kinetics relative to the wild-type strain. The lipid A modification catalyzed by R. etli PagL, therefore, is not required for nodulation but may play other roles such as protecting bacterial endosymbionts from plant immune responses during infection.}, }
@article {pmid23572576, year = {2013}, author = {Hilbe, C and Nowak, MA and Sigmund, K}, title = {Evolution of extortion in Iterated Prisoner's Dilemma games.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, number = {17}, pages = {6913-6918}, pmid = {23572576}, issn = {1091-6490}, support = {I 106/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {*Biological Evolution ; Computer Simulation ; *Cooperative Behavior ; *Game Theory ; Games, Experimental ; Humans ; *Models, Biological ; }, abstract = {Iterated games are a fundamental component of economic and evolutionary game theory. They describe situations where two players interact repeatedly and have the ability to use conditional strategies that depend on the outcome of previous interactions, thus allowing for reciprocation. Recently, a new class of strategies has been proposed, so-called "zero-determinant" strategies. These strategies enforce a fixed linear relationship between one's own payoff and that of the other player. A subset of those strategies allows "extortioners" to ensure that any increase in one player's own payoff exceeds that of the other player by a fixed percentage. Here, we analyze the evolutionary performance of this new class of strategies. We show that in reasonably large populations, they can act as catalysts for the evolution of cooperation, similar to tit-for-tat, but that they are not the stable outcome of natural selection. In very small populations, however, extortioners hold their ground. Extortion strategies do particularly well in coevolutionary arms races between two distinct populations. Significantly, they benefit the population that evolves at the slower rate, an example of the so-called "Red King" effect. This may affect the evolution of interactions between host species and their endosymbionts.}, }
@article {pmid23570961, year = {2013}, author = {Ratzka, C and Gross, R and Feldhaar, H}, title = {Gene expression analysis of the endosymbiont-bearing midgut tissue during ontogeny of the carpenter ant Camponotus floridanus.}, journal = {Journal of insect physiology}, volume = {59}, number = {6}, pages = {611-623}, doi = {10.1016/j.jinsphys.2013.03.011}, pmid = {23570961}, issn = {1879-1611}, mesh = {Amino Acid Sequence ; Animals ; Ants/*genetics/*microbiology/physiology ; Digestive System/metabolism/microbiology ; Enterobacteriaceae/*physiology ; Gene Expression ; Insect Proteins/*genetics/metabolism ; Molecular Sequence Data ; Sequence Alignment ; *Symbiosis ; }, abstract = {Insects have frequently evolved mutualistic relationships with extracellular and/or intracellular bacterial endosymbionts. Infection with endosymbionts seems to affect several cellular functions of the host such as immune pathways, oxidative stress regulation and autophagy. Our current knowledge about specific host factors leading to endosymbiont tolerance and/or control is still scarce and is based on very few associations between insect hosts and bacteria only. Camponotus floridanus ants harbour the obligate intracellular bacterium Blochmannia floridanus within specialized midgut cells called bacteriocytes. The number of Blochmannia endosymbionts within the midgut tissue increases strongly during host development and reaches a maximum at the late pupal stage, where the entire midgut is transformed into a symbiotic organ. After eclosion of workers the number of Blochmannia strongly decreases again. We chose 15 candidate genes from C. floridanus likely to be involved in host-symbiont interactions based on their significant homology to previously investigated symbiosis-relevant genes from other insects. We determined the expression of these genes in the endosymbiont-bearing midgut tissue in comparison to the residual body tissue at different developmental stages of C. floridanus in order to reveal changes in gene expression correlating with changes in endosymbiont number per host. Strikingly, two pattern recognition receptors (amidase PGRP-LB and PGRP-SC2) were highly expressed in the midgut tissue at the pupal stage, potentially down-modulating the IMD pathway to enable endosymbiont tolerance. Moreover, we investigated the immune gene expression in response to bacterial challenge at the pupal stage. Results showed that the midgut tissue differs in expression pattern in contrast to the residual body. Our results support a key role for amidase PGRPs, especially PGRP-LB, in regulation of the immune response towards endosymbionts in C. floridanus and suggest an involvement of the lysosomal system in control of Blochmannia endosymbionts.}, }
@article {pmid23567491, year = {2013}, author = {Park, MS and Park, P and Takeda, M}, title = {Roles of fat body trophocytes, mycetocytes and urocytes in the American cockroach, Periplaneta americana under starvation conditions: an ultrastructural study.}, journal = {Arthropod structure &amp; development}, volume = {42}, number = {4}, pages = {287-295}, doi = {10.1016/j.asd.2013.03.004}, pmid = {23567491}, issn = {1873-5495}, mesh = {Animals ; Bacteria/cytology/ultrastructure ; Bacterial Physiological Phenomena ; Fat Body/cytology/microbiology/*physiology/ultrastructure ; Food Deprivation/physiology ; Lipid Metabolism ; Longevity ; Male ; Microscopy, Electron, Transmission ; Periplaneta/*cytology/microbiology/*physiology/ultrastructure ; Symbiosis ; }, abstract = {In insects, trophocytes (adipocytes) are major cells of a storage organ, the fat body, from which stored glycogen and lipids are mobilized under starvation. However, cockroaches have 2 additional types of cell in the fat body: mycetocytes harboring an endosymbiont, Blattabacterium cuenoti, and urocytes depositing uric acid in urate vacuoles. These cells have not been investigated in terms of their roles under starvation conditions. To gain insight into the roles of trophocytes, mycetocytes and urocytes in cockroaches, structural changes were first investigated in the cells associated with starvation in the American cockroach, Periplaneta americana, by light and electron microscopy. The area of lipid droplets in trophocytes, the endosymbiont population and mitotic activity in mycetocytes, and the area of urate vacuoles in urocytes were analyzed in association with survival rates of the starved cockroaches. After 2 weeks of starvation, trophocytes lost glycogen rosettes and their area of lipid droplets decreased, but almost all cockroaches survived this period. However, further starvation did not reduce the area, but the survival rates dropped rapidly and all cockroaches died in 7 weeks. Endosymbionts were not affected in terms of population size and mitotic activity, even if the cockroaches were dying. The area of urate vacuoles rapidly decreased in a week of starvation and did not recover upon further starvation. These results indicate that starved cockroaches mobilize glycogen and lipids stored in trophocytes to survive for 2 weeks and then die after the exhaustion of nutrients in these cells. Endosymbionts are not digested for the recycling of nutrients, but uric acid is reused under starvation.}, }
@article {pmid23560078, year = {2013}, author = {Motta, MC and Martins, AC and de Souza, SS and Catta-Preta, CM and Silva, R and Klein, CC and de Almeida, LG and de Lima Cunha, O and Ciapina, LP and Brocchi, M and Colabardini, AC and de Araujo Lima, B and Machado, CR and de Almeida Soares, CM and Probst, CM and de Menezes, CB and Thompson, CE and Bartholomeu, DC and Gradia, DF and Pavoni, DP and Grisard, EC and Fantinatti-Garboggini, F and Marchini, FK and Rodrigues-Luiz, GF and Wagner, G and Goldman, GH and Fietto, JL and Elias, MC and Goldman, MH and Sagot, MF and Pereira, M and Stoco, PH and de Mendonça-Neto, RP and Teixeira, SM and Maciel, TE and de Oliveira Mendes, TA and Ürményi, TP and de Souza, W and Schenkman, S and de Vasconcelos, AT}, title = {Predicting the proteins of Angomonas deanei, Strigomonas culicis and their respective endosymbionts reveals new aspects of the trypanosomatidae family.}, journal = {PloS one}, volume = {8}, number = {4}, pages = {e60209}, pmid = {23560078}, issn = {1932-6203}, mesh = {Bacteria/metabolism ; Base Composition ; Base Sequence ; Biological Evolution ; *Genes, Protozoan ; Leishmania major/genetics ; Metabolic Networks and Pathways ; Molecular Sequence Annotation ; Molecular Sequence Data ; Open Reading Frames ; *Phylogeny ; Protozoan Proteins/*genetics/metabolism ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis/*genetics ; Trypanosomatina/classification/*genetics/metabolism/microbiology ; }, abstract = {Endosymbiont-bearing trypanosomatids have been considered excellent models for the study of cell evolution because the host protozoan co-evolves with an intracellular bacterium in a mutualistic relationship. Such protozoa inhabit a single invertebrate host during their entire life cycle and exhibit special characteristics that group them in a particular phylogenetic cluster of the Trypanosomatidae family, thus classified as monoxenics. In an effort to better understand such symbiotic association, we used DNA pyrosequencing and a reference-guided assembly to generate reads that predicted 16,960 and 12,162 open reading frames (ORFs) in two symbiont-bearing trypanosomatids, Angomonas deanei (previously named as Crithidia deanei) and Strigomonas culicis (first known as Blastocrithidia culicis), respectively. Identification of each ORF was based primarily on TriTrypDB using tblastn, and each ORF was confirmed by employing getorf from EMBOSS and Newbler 2.6 when necessary. The monoxenic organisms revealed conserved housekeeping functions when compared to other trypanosomatids, especially compared with Leishmania major. However, major differences were found in ORFs corresponding to the cytoskeleton, the kinetoplast, and the paraflagellar structure. The monoxenic organisms also contain a large number of genes for cytosolic calpain-like and surface gp63 metalloproteases and a reduced number of compartmentalized cysteine proteases in comparison to other TriTryp organisms, reflecting adaptations to the presence of the symbiont. The assembled bacterial endosymbiont sequences exhibit a high A+T content with a total of 787 and 769 ORFs for the Angomonas deanei and Strigomonas culicis endosymbionts, respectively, and indicate that these organisms hold a common ancestor related to the Alcaligenaceae family. Importantly, both symbionts contain enzymes that complement essential host cell biosynthetic pathways, such as those for amino acid, lipid and purine/pyrimidine metabolism. These findings increase our understanding of the intricate symbiotic relationship between the bacterium and the trypanosomatid host and provide clues to better understand eukaryotic cell evolution.}, }
@article {pmid23555728, year = {2013}, author = {Baton, LA and Pacidônio, EC and Gonçalves, DS and Moreira, LA}, title = {wFlu: characterization and evaluation of a native Wolbachia from the mosquito Aedes fluviatilis as a potential vector control agent.}, journal = {PloS one}, volume = {8}, number = {3}, pages = {e59619}, pmid = {23555728}, issn = {1932-6203}, mesh = {Aedes/cytology/drug effects/growth &amp; development/*microbiology ; Animals ; Cytoplasm/microbiology ; Female ; Fertility ; Humans ; Insect Control/*methods ; Insect Vectors/cytology/drug effects/growth &amp; development/*microbiology ; Male ; Oocysts/microbiology ; Organ Specificity ; Pest Control, Biological/*methods ; Sex Characteristics ; Tetracycline/pharmacology ; Wolbachia/drug effects/*physiology ; }, abstract = {There is currently considerable interest and practical progress in using the endosymbiotic bacteria Wolbachia as a vector control agent for human vector-borne diseases. Such vector control strategies may require the introduction of multiple, different Wolbachia strains into target vector populations, necessitating the identification and characterization of appropriate endosymbiont variants. Here, we report preliminary characterization of wFlu, a native Wolbachia from the neotropical mosquito Aedes fluviatilis, and evaluate its potential as a vector control agent by confirming its ability to cause cytoplasmic incompatibility, and measuring its effect on three parameters determining host fitness (survival, fecundity and fertility), as well as vector competence (susceptibility) for pathogen infection. Using an aposymbiotic strain of Ae. fluviatilis cured of its native Wolbachia by antibiotic treatment, we show that in its natural host wFlu causes incomplete, but high levels of, unidirectional cytoplasmic incompatibility, has high rates of maternal transmission, and no detectable fitness costs, indicating a high capacity to rapidly spread through host populations. However, wFlu does not inhibit, and even enhances, oocyst infection with the avian malaria parasite Plasmodium gallinaceum. The stage- and sex-specific density of wFlu was relatively low, and with limited tissue distribution, consistent with the lack of virulence and pathogen interference/symbiont-mediated protection observed. Unexpectedly, the density of wFlu was also shown to be specifically-reduced in the ovaries after bloodfeeding Ae. fluviatilis. Overall, our observations indicate that the Wolbachia strain wFlu has the potential to be used as a vector control agent, and suggests that appreciable mutualistic coevolution has occurred between this endosymbiont and its natural host. Future work will be needed to determine whether wFlu has virulent host effects and/or exhibits pathogen interference when artificially-transfected to the novel mosquito hosts that are the vectors of human pathogens.}, }
@article {pmid23551942, year = {2013}, author = {Kern, R and Eisenhut, M and Bauwe, H and Weber, AP and Hagemann, M}, title = {Does the Cyanophora paradoxa genome revise our view on the evolution of photorespiratory enzymes?.}, journal = {Plant biology (Stuttgart, Germany)}, volume = {15}, number = {4}, pages = {759-768}, doi = {10.1111/plb.12003}, pmid = {23551942}, issn = {1438-8677}, mesh = {Alcohol Oxidoreductases/genetics ; *Biological Evolution ; Carbon Dioxide/metabolism ; Cell Respiration/genetics ; Cyanobacteria/enzymology/genetics/radiation effects ; Cyanophora/*enzymology/genetics/radiation effects ; DNA, Plant/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Eukaryota/enzymology/genetics/radiation effects ; Genome, Plant/*genetics ; Hydroxypyruvate Reductase/genetics ; Light ; Oxygen/metabolism ; Phosphoric Monoester Hydrolases/genetics ; Photosynthesis ; Phylogeny ; Plant Proteins/*genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Transaminases/genetics ; }, abstract = {In the present-day O2 -rich atmosphere, the photorespiratory pathway is essential for organisms performing oxygenic photosynthesis; i.e. cyanobacteria, algae and land plants. The presence of enzymes for the plant-like 2-phosphoglycolate cycle in cyanobacteria indicates that, together with oxygenic photosynthesis, genes for photorespiratory enzymes were endosymbiotically conveyed from ancient cyanobacteria to photosynthetic eukaryotes. The genome information for Cyanophora paradoxa, a member of the Glaucophyta representing the first branching group of primary endosymbionts, and for many other eukaryotic algae was used to shed light on the evolutionary relationship of photorespiratory enzymes among oxygenic phototrophs. For example, it became possible to analyse the phylogenies of 2-phosphoglycolate phosphatase, serine:glyoxylate aminotransferase and hydroxypyruvate reductase. Analysis of the Cyanophora genome provided clear evidence that some photorespiratory enzymes originally acquired from cyanobacteria were lost, e.g. glycerate 3-kinase, while others were replaced by the corresponding enzymes from the α-proteobacterial endosymbiont, e.g. serine:glyoxylate aminotransferase. Generally, our analysis supports the view that many C2 cycle enzymes in eukaryotic phototrophs were obtained from the cyanobacterial endosymbiont, but during the subsequent evolution of algae and land plants multiple losses and replacements occurred, which resulted in a reticulate provenance of photorespiratory enzymes with different origins in different cellular compartments.}, }
@article {pmid23550746, year = {2013}, author = {Haselkorn, TS and Cockburn, SN and Hamilton, PT and Perlman, SJ and Jaenike, J}, title = {Infectious adaptation: potential host range of a defensive endosymbiont in Drosophila.}, journal = {Evolution; international journal of organic evolution}, volume = {67}, number = {4}, pages = {934-945}, doi = {10.1111/evo.12020}, pmid = {23550746}, issn = {1558-5646}, mesh = {*Adaptation, Biological ; Animals ; Disease Resistance ; Drosophila/*microbiology/parasitology ; Evolution, Molecular ; Female ; Fertility ; *Host Specificity ; *Nematoda ; *Spiroplasma ; *Symbiosis ; }, abstract = {Maternally transmitted symbionts persist over macroevolutionary timescales by undergoing occasional lateral transfer to new host species. To invade a new species, a symbiont must survive and reproduce in the new host, undergo maternal transmission, and confer a selective benefit sufficient to overcome losses due to imperfect maternal transmission. Drosophila neotestacea is naturally infected with a strain of Spiroplasma that restores fertility to nematode-parasitized females, which are otherwise sterilized by parasitism. We experimentally transferred Spiroplasma from D. neotestacea to four other species of mycophagous Drosophila that vary in their ability to resist and/or tolerate nematode parasitism. In all four species, Spiroplasma achieved within-host densities and experienced rates of maternal transmission similar to that in D. neotestacea. Spiroplasma restored fertility to nematode-parasitized females in one of these novel host species. Based on estimates of maternal transmission fidelity and the expected benefit of Spiroplasma infection in the wild, we conclude that Spiroplasma has the potential to spread and become abundant within Drosophila putrida, which is broadly sympatric with D. neotestacea and in which females are rendered completely sterile by nematode parasitism. Thus, a major adaptation within D. putrida could arise via lateral transmission of a heritable symbiont from D. neotestacea.}, }
@article {pmid23550173, year = {2012}, author = {Kraaijeveld, K and Bast, J}, title = {Transposable element proliferation as a possible side effect of endosymbiont manipulations.}, journal = {Mobile genetic elements}, volume = {2}, number = {5}, pages = {253-256}, pmid = {23550173}, issn = {2159-2543}, abstract = {The mode of reproduction has been predicted to affect the proliferation of transposable elements (TEs). A population that switches from sexual to asexual reproduction could either accumulate TEs because purifying selection becomes less efficient, or a decrease in TE load because the opportunity for horizontal transmission is reduced. A third possibility is that the mechanism that induces asexual reproduction affects TE dynamics as a side effect. We propose two such mechanisms that might explain recently described patterns of TE abundance in sexual and asexual lineages of the parasitoid wasp Leptopilina clavipes. Asexual reproduction in this species is induced by endosymbiotic Wolbachia bacteria. In order to achieve parthenogenesis in its host, Wolbachia might remove methylation or interfere with Argonaute proteins. Both methylation and Argonaute proteins are known to control TE activity in other species. By interfering with either, Wolbachia might therefore secondarily hamper the control of specific TEs.}, }
@article {pmid23549902, year = {2013}, author = {Hou, Y and Ma, Z and Dong, S and Chen, YH and Yu, X}, title = {Analysis of yeast-like symbiote diversity in the brown planthopper (BPH), Nilaparvata lugens Stål, using a novel nested PCR-DGGE protocol.}, journal = {Current microbiology}, volume = {67}, number = {3}, pages = {263-270}, pmid = {23549902}, issn = {1432-0991}, mesh = {Animals ; *Biodiversity ; DNA, Fungal/genetics ; DNA, Ribosomal Spacer/genetics ; Denaturing Gradient Gel Electrophoresis/*methods ; Hemiptera/*microbiology ; Polymerase Chain Reaction/*methods ; RNA, Ribosomal, 18S/genetics ; Yeasts/*classification/*genetics ; }, abstract = {Yeast-like symbiotes (YLS) are endosymbionts that are intimately associated with the growth, development, reproduction of their host, the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae). However, it is unclear how many species of YLS are found within N. lugens, and how they are related to each other. Traditional methods or simple amplification based on 18S rDNA sequence does not reliably identify new species quickly and efficiently. Therefore, a novel nested PCR-denaturing gradient gel electrophoresis (DGGE) strategy was developed in this article to analyze the YLS of brown planthopper using a nested PCR protocol that involved the 18S rDNA gene and the 5.8S-ITS gene using fungal universal primers. The nested PCR protocol was developed as follows: firstly, the 18S rDNA gene, and 5.8S-ITS gene were amplified using fungal universal primers. Subsequently, these products were used as a template in a second PCR with primers ITS1GC-ITS2, ITS1FGC-ITS2, and NFGC-NR, which was suitable for DGGE. Using this highly specific molecular approach, we found several previously detected fungi: Noda, Pichia guilliermondii, Candida sp., and some previously undetected fungi, such as Saccharomycetales sp., Debaryomyces hansenii, and some uncultured fungi. In conclusion, the nested PCR system developed in this study, coupled with DGGE fingerprinting, offers a new tool for uncovering fungal endosymbiont diversity within planthoppers.}, }
@article {pmid23548081, year = {2013}, author = {López-Madrigal, S and Latorre, A and Porcar, M and Moya, A and Gil, R}, title = {Mealybugs nested endosymbiosis: going into the 'matryoshka' system in Planococcus citri in depth.}, journal = {BMC microbiology}, volume = {13}, number = {}, pages = {74}, pmid = {23548081}, issn = {1471-2180}, mesh = {Animals ; Betaproteobacteria/isolation &amp; purification/*physiology ; DNA, Bacterial/chemistry/genetics ; Enterobacteriaceae/isolation &amp; purification/*physiology ; Genome, Bacterial ; Hemiptera/*microbiology/*physiology ; Molecular Sequence Data ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: In all branches of life there are plenty of symbiotic associations. Insects are particularly well suited to establishing intracellular symbiosis with bacteria, providing them with metabolic capabilities they lack. Essential primary endosymbionts can coexist with facultative secondary symbionts which can, eventually, establish metabolic complementation with the primary endosymbiont, becoming a co-primary. Usually, both endosymbionts maintain their cellular identity. An exception is the endosymbiosis found in mealybugs of the subfamily Pseudoccinae, such as Planococcus citri, with Moranella endobia located inside Tremblaya princeps.<br><br>RESULTS: We report the genome sequencing of M. endobia str. PCVAL and the comparative genomic analyses of the genomes of strains PCVAL and PCIT of both consortium partners. A comprehensive analysis of their functional capabilities and interactions reveals their functional coupling, with many cases of metabolic and informational complementation. Using comparative genomics, we confirm that both genomes have undergone a reductive evolution, although with some unusual genomic features as a consequence of coevolving in an exceptional compartmentalized organization.<br><br>CONCLUSIONS: M. endobia seems to be responsible for the biosynthesis of most cellular components and energy provision, and controls most informational processes for the consortium, while T. princeps appears to be a mere factory for amino acid synthesis, and translating proteins, using the precursors provided by M. endobia. In this scenario, we propose that both entities should be considered part of a composite organism whose compartmentalized scheme (somehow) resembles a eukaryotic cell.}, }
@article {pmid23547913, year = {2013}, author = {Cook, D and Beaulieu, WT and Mott, IW and Riet-Correa, F and Gardner, DR and Grum, D and Pfister, JA and Clay, K and Marcolongo-Pereira, C}, title = {Production of the alkaloid swainsonine by a fungal endosymbiont of the Ascomycete order Chaetothyriales in the host Ipomoea carnea.}, journal = {Journal of agricultural and food chemistry}, volume = {61}, number = {16}, pages = {3797-3803}, doi = {10.1021/jf4008423}, pmid = {23547913}, issn = {1520-5118}, mesh = {Ascomycota/*metabolism ; Fungicides, Industrial/administration &amp; dosage ; Ipomoea/*microbiology ; Microscopy, Electron, Scanning ; Plant Diseases/microbiology ; Plant Leaves/microbiology/ultrastructure ; Seeds/microbiology ; Swainsonine/*metabolism ; Symbiosis ; }, abstract = {Some plant species within the Convolvulaceae (morning glory family) from South America, Africa, and Australia cause a neurologic disease in grazing livestock caused by swainsonine. These convolvulaceous species including Ipomoea carnea contain the indolizidine alkaloid swainsonine, an inhibitor of α-mannosidase and mannosidase II, and polyhydroxy nortropane alkaloids, the calystegines which are glycosidase inhibitors. Swainsonine has been shown to be produced by a fungal endosymbiont in legumes of the Astragalus and Oxytropis genera, where it causes a similar neurologic disease in grazing livestock called locoism. Here we demonstrate that I. carnea plants are infected with a fungal endosymbiont that was cultured from its seeds and which produced swainsonine in pure culture but not the calystegines. The same fungal endosymbiont was detected by PCR and by culturing in I. carnea plants containing swainsonine. The fungal endosymbiont belongs to the Ascomycete order Chaetothyriales. Plants derived from fungicide-treated seeds lacked swainsonine, but calystegine concentrations were unaltered.}, }
@article {pmid23542079, year = {2013}, author = {Sloan, DB and Moran, NA}, title = {The evolution of genomic instability in the obligate endosymbionts of whiteflies.}, journal = {Genome biology and evolution}, volume = {5}, number = {5}, pages = {783-793}, pmid = {23542079}, issn = {1759-6653}, support = {F32 GM099334/GM/NIGMS NIH HHS/United States ; 1F32GM099334/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Evolution, Molecular ; Genome, Bacterial ; *Genomic Instability ; Halomonadaceae/*genetics ; Hemiptera/*genetics/microbiology/physiology ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Many insects depend on ancient associations with intracellular bacteria to perform essential metabolic functions. These endosymbionts exhibit striking examples of convergence in genome architecture, including a high degree of structural stability that is not typical of their free-living counterparts. However, the recently sequenced genome of the obligate whitefly endosymbiont Portiera revealed features that distinguish it from other ancient insect associates, such as a low gene density and the presence of perfectly duplicated sequences. Here, we report the comparative analysis of Portiera genome sequences both within and between host species. In one whitefly lineage (Bemisia tabaci), we identify large-scale structural polymorphisms in the Portiera genome that exist even within individual insects. This variation is likely mediated by recombination across identical repeats that are maintained by gene conversion. The complete Portiera genome sequence from a distantly related whitefly host (Trialeurodes vaporarium) confirms a history of extensive genome rearrangement in this ancient endosymbiont. Using gene-order-based phylogenetic analysis, we show that the majority of rearrangements have occurred in the B. tabaci lineage, coinciding with an increase in the rate of nucleotide substitutions, a proliferation of short tandem repeats (microsatellites) in intergenic regions, and the loss of many widely conserved genes involved in DNA replication, recombination, and repair. These results indicate that the loss of recombinational machinery is unlikely to be the cause of the extreme structural conservation that is generally observed in obligate endosymbiont genomes and that large, repetitive intergenic regions are an important substrate for genomic rearrangements.}, }
@article {pmid23535187, year = {2013}, author = {Van Elst, D and Nuyens, S and van Wyk, B and Verstraete, B and Dessein, S and Prinsen, E}, title = {Distribution of the cardiotoxin pavettamine in the coffee family (Rubiaceae) and its significance for gousiekte, a fatal poisoning of ruminants.}, journal = {Plant physiology and biochemistry : PPB}, volume = {67}, number = {}, pages = {15-19}, doi = {10.1016/j.plaphy.2013.02.022}, pmid = {23535187}, issn = {1873-2690}, mesh = {Animals ; Mass Spectrometry ; Polyamines/*metabolism ; Psychotria/metabolism ; Rubiaceae/*metabolism ; Ruminants ; }, abstract = {Gousiekte, a cardiac syndrome of ruminants in southern Africa, is caused by the ingestion of plants containing the polyamine pavettamine. All the six known gousiekte-causing plants are members of the Rubiaceae or coffee family and house endosymbiotic Burkholderia bacteria in their leaves. It was therefore hypothesized that these bacteria could be involved in the production of the toxin. The pavettamine level in the leaves of 82 taxa from 14 genera was determined. Included in the analyses were various nodulated and non-nodulated members of the Rubiaceae. This led to the discovery of other pavettamine producing Rubiaceae, namely Psychotria kirkii and Psychotria viridiflora. Our analysis showed that many plant species containing bacterial nodules in their leaves do not produce pavettamine. It is consequently unlikely that the endosymbiont alone can be accredited for the synthesis of the toxin. Until now the inconsistent toxicity of the gousiekte-causing plants have hindered studies that aimed at a better understanding of the disease. In vitro dedifferentiated plant cell cultures are a useful tool for the study of molecular processes. Plant callus cultures were obtained from pavettamine-positive species. Mass spectrometric analysis shows that these calli do not produce pavettamine but can produce common plant polyamines.}, }
@article {pmid23533102, year = {2013}, author = {Vorburger, C and Ganesanandamoorthy, P and Kwiatkowski, M}, title = {Comparing constitutive and induced costs of symbiont-conferred resistance to parasitoids in aphids.}, journal = {Ecology and evolution}, volume = {3}, number = {3}, pages = {706-713}, pmid = {23533102}, issn = {2045-7758}, abstract = {Host defenses against parasites do not come for free. The evolution of increased resistance can be constrained by constitutive costs associated with possessing defense mechanisms, and by induced costs of deploying them. These two types of costs are typically considered with respect to resistance as a genetically determined trait, but they may also apply to resistance provided by 'helpers' such as bacterial endosymbionts. We investigated the costs of symbiont-conferred resistance in the black bean aphid, Aphis fabae (Scopoli), which receives strong protection against the parasitoid Lysiphlebus fabarum from the defensive endosymbiont Hamiltonella defensa. Aphids infected with H. defensa were almost ten times more resistant to L. fabarum than genetically identical aphids without this symbiont, but in the absence of parasitoids, they had strongly reduced lifespans, resulting in lower lifetime reproduction. This is evidence for a substantial constitutive cost of harboring H. defensa. We did not observe any induced cost of symbiont-conferred resistance. On the contrary, symbiont-protected aphids that resisted a parasitoid attack enjoyed increased longevity and lifetime reproduction compared with unattacked controls, whereas unprotected aphids suffered a reduction of longevity and reproduction after resisting an attack. This surprising result suggests that by focusing exclusively on the protection, we might underestimate the selective advantage of infection with H. defensa in the presence of parasitoids.}, }
@article {pmid23525074, year = {2013}, author = {Desjardins, CA and Cerqueira, GC and Goldberg, JM and Dunning Hotopp, JC and Haas, BJ and Zucker, J and Ribeiro, JM and Saif, S and Levin, JZ and Fan, L and Zeng, Q and Russ, C and Wortman, JR and Fink, DL and Birren, BW and Nutman, TB}, title = {Genomics of Loa loa, a Wolbachia-free filarial parasite of humans.}, journal = {Nature genetics}, volume = {45}, number = {5}, pages = {495-500}, pmid = {23525074}, issn = {1546-1718}, support = {DP2 OD007372/OD/NIH HHS/United States ; HHSN272200900018C/AI/NIAID NIH HHS/United States ; Z01 AI000512-21//Intramural NIH HHS/United States ; 1-DP2-OD007372/OD/NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/genetics ; Filariasis/*genetics/parasitology ; Filarioidea/*genetics/parasitology ; Genes, Helminth/*genetics ; *Genome, Helminth ; Humans ; Loa/*genetics ; Molecular Sequence Data ; Phylogeny ; Protein Kinases/*metabolism ; Symbiosis ; Wolbachia/*genetics ; Wuchereria bancrofti/genetics ; }, abstract = {Loa loa, the African eyeworm, is a major filarial pathogen of humans. Unlike most filariae, L. loa does not contain the obligate intracellular Wolbachia endosymbiont. We describe the 91.4-Mb genome of L. loa and that of the related filarial parasite Wuchereria bancrofti and predict 14,907 L. loa genes on the basis of microfilarial RNA sequencing. By comparing these genomes to that of another filarial parasite, Brugia malayi, and to those of several other nematodes, we demonstrate synteny among filariae but not with nonparasitic nematodes. The L. loa genome encodes many immunologically relevant genes, as well as protein kinases targeted by drugs currently approved for use in humans. Despite lacking Wolbachia, L. loa shows no new metabolic synthesis or transport capabilities compared to other filariae. These results suggest that the role of Wolbachia in filarial biology is more subtle than previously thought and reveal marked differences between parasitic and nonparasitic nematodes.}, }
@article {pmid23517598, year = {2013}, author = {Fedorov, DN and Ekimova, GA and Doronina, NV and Trotsenko, YA}, title = {1-Aminocyclopropane-1-carboxylate (ACC) deaminases from Methylobacterium radiotolerans and Methylobacterium nodulans with higher specificity for ACC.}, journal = {FEMS microbiology letters}, volume = {343}, number = {1}, pages = {70-76}, doi = {10.1111/1574-6968.12133}, pmid = {23517598}, issn = {1574-6968}, mesh = {Carbon-Carbon Lyases/chemistry/genetics/isolation &amp; purification/*metabolism ; Chromatography, Gel ; Cloning, Molecular ; Computational Biology ; Electrophoresis, Polyacrylamide Gel ; Enzyme Stability ; Escherichia coli/genetics ; Gene Expression ; Hydrogen-Ion Concentration ; Kinetics ; Methylobacterium/*enzymology/genetics ; Molecular Weight ; Recombinant Proteins/chemistry/genetics/isolation &amp; purification/metabolism ; Sequence Homology ; Substrate Specificity ; Temperature ; }, abstract = {The 1-aminocyclopropane-1-carboxylate (ACC) deaminases (EC 3.4.99.7), the key enzymes of degradation of the precursor of the phytohormone ethylene, have not been well studied despite their great importance for plant-bacterial interactions. Using blast, the open reading frames encoding ACC deaminases were found in the genomes of epiphytic methylotroph Methylobacterium radiotolerans JCM2831 and nodule-forming endosymbiont Methylobacterium nodulans ORS2060. These genes were named acdS and cloned; recombinant proteins were expressed and purified from Escherichia coli. The enzyme from M. nodulans displayed the highest substrate specificity among all of the characterized ACC deaminases (Km 0.80 ± 0.04 mM), whereas the enzyme from M. radiotolerans had Km 1.8 ± 0.3 mM. The kcat values were 111.8 ± 0.2 and 65.8 ± 2.8 min(-1) for the enzymes of M. nodulans and M. radiotolerans, respectively. Both enzymes are homotetramers with a molecular mass of 144 kDa, as was demonstrated by size exclusion chromatography and native PAGE. The purified enzymes displayed the maximum activity at 45-50 °C and pH 8.0. Thus, the priority data have been obtained, extending the knowledge of biochemical properties of bacterial ACC deaminases.}, }
@article {pmid23511636, year = {2013}, author = {Brown, DB and Muszynski, A and Salas, O and Speed, K and Carlson, RW}, title = {Elucidation of the 3-O-deacylase gene, pagL, required for the removal of primary β-hydroxy fatty acid from the lipid A in the nitrogen-fixing endosymbiont Rhizobium etli CE3.}, journal = {The Journal of biological chemistry}, volume = {288}, number = {17}, pages = {12004-12013}, pmid = {23511636}, issn = {1083-351X}, support = {R01 GM039583/GM/NIGMS NIH HHS/United States ; GM39583/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacterial Proteins/genetics/*metabolism ; Carboxylic Ester Hydrolases/genetics/*metabolism ; Fatty Acids/genetics/*metabolism ; Lipid A/*biosynthesis/genetics ; Phaseolus/microbiology/physiology ; Rhizobium/*enzymology/genetics ; Symbiosis/physiology ; }, abstract = {Until now, the gene responsible for the 3-O-deacylation of lipid A among nitrogen-fixing endosymbionts has not been characterized. Several Gram-negative animal pathogens such as Salmonella enterica, Pseudomonas aeruginosa, and Bordetella bronchiseptica contain an outer membrane 3-O-deacylase (PagL) that has been implicated in host immune evasion. The role of 3-O-deacylated lipid A among nitrogen-fixing endosymbionts, plant endophytes, and plant pathogens has not been studied. However, D'Haeze et al. (D'Haeze, W., Leoff, C., Freshour, G., Noel, K. D., and Carlson, R. W. (2007) J. Biol. Chem. 282, 17101-17113) reported that the lipopolysaccharide from Rhizobium etli CE3 bacteroids isolated from host bean root nodules contained exclusively tetraacylated lipid A that lacked a lipid A β-hydroxymyristyl residue, an observation that is consistent with the possibility of PagL activity being important in symbiosis. A putative pagL gene was identified in the R. etli genome sequence. With this information, we created a pagL(-) mutant strain derived from R. etli CE3. Using mass spectrometry, we demonstrated that the mutant lacks 3-O-deacylated lipid A. The parent and mutant LPS were very similar as determined by gel electrophoresis and glycosyl composition analysis using gas chromatography/mass spectrometry. However, fatty acid analysis showed that the mutant lipid A contained larger amounts of β-hydroxypentadecanoic acid than that of the parent. Furthermore, the mutant was adversely affected in establishing symbiosis with its host, Phaseolus vulgaris.}, }
@article {pmid23508299, year = {2013}, author = {Eleftherianos, I and Atri, J and Accetta, J and Castillo, JC}, title = {Endosymbiotic bacteria in insects: guardians of the immune system?.}, journal = {Frontiers in physiology}, volume = {4}, number = {}, pages = {46}, pmid = {23508299}, issn = {1664-042X}, abstract = {Insects have evolved obligate, mutualistic interactions with bacteria without further transmission to other eukaryotic organisms. Such long-term obligate partnerships between insects and bacteria have a profound effect on various physiological functions of the host. Here we provide an overview of the effects of endosymbiotic bacteria on the insect immune system as well as on the immune response of insects to pathogenic infections. Potential mechanisms through which endosymbionts can affect the ability of their host to resist an infection are discussed in the light of recent findings. We finally point out unresolved questions for future research and speculate how the current knowledge can be employed to design and implement measures for the effective control of agricultural insect pests and vectors of diseases.}, }
@article {pmid23505512, year = {2013}, author = {Rey, O and Estoup, A and Facon, B and Loiseau, A and Aebi, A and Duron, O and Vavre, F and Foucaud, J}, title = {Distribution of endosymbiotic reproductive manipulators reflects invasion process and not reproductive system polymorphism in the little fire ant Wasmannia auropunctata.}, journal = {PloS one}, volume = {8}, number = {3}, pages = {e58467}, pmid = {23505512}, issn = {1932-6203}, mesh = {Animals ; Ants/*microbiology/*physiology ; Female ; Genes, Bacterial ; Genotype ; Male ; Molecular Sequence Data ; Multilocus Sequence Typing ; Phylogeny ; *Reproduction ; *Symbiosis ; Wolbachia/classification/*genetics ; }, abstract = {Endosymbiotic reproductive manipulators may have drastic effects on the ecological and evolutionary dynamics of their hosts. The prevalence of these endosymbionts reflects both their ability to manipulate their hosts and the history of the host populations. The little fire ant Wasmannia auropunctata displays a polymorphism in both its reproductive system (sexual versus clonal populations) and the invasive status of its populations (associated to a habitat shift). We first screened for the presence of a diverse array of reproductive parasites in sexual and clonal populations of W. auropunctata, as a means to investigate the role of endosymbionts in reproductive phenotypes. Wolbachia was the only symbiont found and we then focused on its worldwide distribution and diversity in natural populations of W. auropunctata. Using a multilocus scheme, we further characterized the Wolbachia strains present in these populations. We found that almost all the native sexual populations and only a few clonal populations are infected by Wolbachia. The presence of similar Wolbachia strains in both sexual and clonal populations indicates that they are probably not the cause of the reproductive system polymorphism. The observed pattern seems rather associated to the invasion process of W. auropunctata. In particular, the observed loss of Wolbachia in clonal populations, that recurrently emerged from sexual populations, likely resulted from natural heat treatment and/or relaxed selection during the shift in habitat associated to the invasion process.}, }
@article {pmid23504738, year = {2013}, author = {Ortiz, JC and González-Rivero, M and Mumby, PJ}, title = {Can a thermally tolerant symbiont improve the future of Caribbean coral reefs?.}, journal = {Global change biology}, volume = {19}, number = {1}, pages = {273-281}, doi = {10.1111/gcb.12027}, pmid = {23504738}, issn = {1354-1013}, mesh = {*Adaptation, Physiological ; Animals ; Caribbean Region ; *Climate Change ; *Coral Reefs ; *Symbiosis ; *Temperature ; }, abstract = {The detrimental effect of climate change induced bleaching on Caribbean coral reefs has been widely documented in recent decades. Several studies have suggested that increases in the abundance of thermally tolerant endosymbionts may ameliorate the effect of climate change on reefs. Symbionts that confer tolerance to temperature also reduce the growth rate of their coral host. Here, we show, using a spatial ecosystem model, that an increment in the abundance of a thermally tolerant endosymbiont (D1a) is unlikely to ensure the persistence of Caribbean reefs, or to reduce their rate of decline, due to the concomitant reduction in growth rate under current thermal stress predictive scenarios. Furthermore, our results suggest that given the documented vital rates of D1a-dominated corals, increasing dominance of D1a in coral hosts may have a detrimental effect by reducing the resilience of Caribbean reefs, and preventing their long-term recovery. This is because Caribbean ecosystems appear to be highly sensitive to changes in the somatic growth rate of corals. Alternative outcomes might be expected in systems with different community-level dynamics such as reefs in the Indo-Pacific, where the ecological costs of reduced growth rate might be far smaller.}, }
@article {pmid23499613, year = {2013}, author = {Hollants, J and Leliaert, F and Verbruggen, H and De Clerck, O and Willems, A}, title = {Host specificity and coevolution of Flavobacteriaceae endosymbionts within the siphonous green seaweed Bryopsis.}, journal = {Molecular phylogenetics and evolution}, volume = {67}, number = {3}, pages = {608-614}, doi = {10.1016/j.ympev.2013.02.025}, pmid = {23499613}, issn = {1095-9513}, mesh = {*Evolution, Molecular ; Flavobacteriaceae/classification/*genetics ; Genes, Bacterial ; Genes, Plant ; Genetic Variation ; Genotype ; *Host Specificity ; Mutation ; Phylogeny ; Phylogeography ; RNA, Ribosomal, 16S/genetics ; Seaweed/*genetics/*microbiology ; Symbiosis ; }, abstract = {The siphonous green seaweed Bryopsis harbors complex intracellular bacterial communities. Previous studies demonstrated that certain species form close, obligate associations with Flavobacteriaceae. A predominant imprint of host evolutionary history on the presence of these bacteria suggests a highly specialized association. In this study we elaborate on previous results by expanding the taxon sampling and testing for host-symbiont coevolution Therefore, we optimized a PCR protocol to directly and specifically amplify Flavobacteriaceae endosymbiont 16S rRNA gene sequences, which allowed us to screen a large number of algal samples without the need for cultivation or surface sterilization. We analyzed 146 Bryopsis samples, and 92 additional samples belonging to the Bryopsidales and other orders within the class Ulvophyceae. Results indicate that the Flavobacteriaceae endosymbionts are restricted to Bryopsis, and only occur within specific, warm-temperate and tropical clades of the genus. Statistical analyses (AMOVA) demonstrate a significant non-random host-symbiont association. Comparison of bacterial 16S rRNA and Bryopsis rbcL phylogenies, however, reveal complex host-symbiont evolutionary associations, whereby closely related hosts predominantly harbor genetically similar endosymbionts. Bacterial genotypes are rarely confined to a single Bryopsis species and most Bryopsis species harbored several Flavobacteriaceae, obscuring a clear pattern of coevolution.}, }
@article {pmid23497177, year = {2013}, author = {Tonk, L and Bongaerts, P and Sampayo, EM and Hoegh-Guldberg, O}, title = {SymbioGBR: a web-based database of Symbiodinium associated with cnidarian hosts on the Great Barrier Reef.}, journal = {BMC ecology}, volume = {13}, number = {}, pages = {7}, pmid = {23497177}, issn = {1472-6785}, mesh = {Animals ; Anthozoa/*microbiology ; Australia ; *Coral Reefs ; DNA, Ribosomal Spacer/genetics ; *Databases, Genetic ; Dinoflagellida/classification/*genetics ; Genetic Markers ; Internet ; Sequence Analysis, DNA ; Symbiosis ; User-Computer Interface ; }, abstract = {BACKGROUND: The algal endosymbionts (genus Symbiodinium) associated with scleractinian corals (and other reef invertebrates) have received a lot of research attention in the past decade, particularly as certain host-symbiont associations appear more affected by increasing seawater temperatures than others. With the rapid accumulation of information on the diversity of Symbiodinium, it is becoming increasingly difficult to compare newly acquired Symbiodinium data with existing data to detect patterns of host-symbiont specificity on broader spatial scales. The lack of a general consensus on the classification of Symbiodinium species coupled with the variety of different markers used to identify the genus Symbiodinium (ITS1, ITS2, LSU D1/D2, chloroplast 23S rDNA and psbA minicircle) further complicate direct comparison.<br><br>DESCRIPTION: The SymbioGBR database compiles all currently available Symbiodinium sequences and associated host information of data collected from the Great Barrier Reef into a single relational database that is accessible via a user-friendly, searchable web-based application (http://www.SymbioGBR.org). SymbioGBR allows users to query Symbiodinium types or sequences sourced from various genetic markers (e.g. ITS1, ITS2, LSU D1/D2 and chloroplast 23S) and invertebrate host species to explore their reported associations. In addition, as the database includes sequence information of multiple genetic markers, it allows cross-referencing between conventional (e.g. ITS2 region) and novel markers that exhibit low intragenomic variability (e.g. psbA region). Finally, the database is based on the collection details of individual specimens. Such host-symbiont associations can be assessed quantitatively and viewed in relation to their environmental and geographic context.<br><br>CONCLUSIONS: The SymbioGBR database provides a comprehensive overview of Symbiodinium diversity and host-associations on the Great Barrier Reef. It provides a quick, user-friendly means to compare newly acquired data on Symbiodinium (e.g. raw sequences or characterized Symbiodinium types) with previous data on the diversity of invertebrate host-symbiont associations on the GBR. The inclusion of psbAncr sequence information allows for validation of widely used ITS1/ITS2 markers and their ability to accurately identify relevant sequences. Most importantly, centralization of sequence information from multiple genetic markers will aid the classification of Symbiodinium species diversity and allow researchers to easily compare patterns of host-Symbiodinium associations.}, }
@article {pmid23482692, year = {2012}, author = {Mackiewicz, P and Bodył, A and Gagat, P}, title = {Protein import into the photosynthetic organelles of Paulinella chromatophora and its implications for primary plastid endosymbiosis.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {58}, number = {1-3}, pages = {99-107}, pmid = {23482692}, issn = {0334-5114}, abstract = {The rhizarian amoeba Paulinella chromatophora harbors two photosynthetically active organelles of cyanobacterial origin that have been acquired independently of classic primary plastids. Because their acquisition did take place relatively recently, they are expected to provide new insight into the ancient cyanobacterial primary endosymbiosis. During the process of Paulinella endosymbiont-to-organelle transformation, more than 30 genes have been transferred from the organelle to the host nuclear genome via endosymbiotic gene transfer (EGT). The article discusses step-by-step protein import of EGT-derived proteins into Paulinella photosynthetic organelles with the emphasis on the nature of their targeting signals and the final passage of proteins through the inner organelle membrane. The latter most probably involves a simplified Tic translocon composed of Tic21- and Tic32-like proteins as well as a Hsp70-based motor responsible for pulling of imported proteins into the organelle matrix. Our results indicate that although protein translocation across the inner membrane of Paulinella photosynthetic organelles seems to resemble the one in classic primary plastids, the transport through the outer membrane does not. The differences could result from distinct integration pathways of Paulinella photosynthetic organelles and primary plastids with their respective host cells.}, }
@article {pmid23482460, year = {2012}, author = {Geniez, S and Foster, JM and Kumar, S and Moumen, B and Leproust, E and Hardy, O and Guadalupe, M and Thomas, SJ and Boone, B and Hendrickson, C and Bouchon, D and Grève, P and Slatko, BE}, title = {Targeted genome enrichment for efficient purification of endosymbiont DNA from host DNA.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {58}, number = {1-3}, pages = {201-207}, pmid = {23482460}, issn = {0334-5114}, abstract = {Wolbachia endosymbionts are widespread in arthropods and are generally considered reproductive parasites, inducing various phenotypes including cytoplasmic incompatibility, parthenogenesis, feminization and male killing, which serve to promote their spread through populations. In contrast, Wolbachia infecting filarial nematodes that cause human diseases, including elephantiasis and river blindness, are obligate mutualists. DNA purification methods for efficient genomic sequencing of these unculturable bacteria have proven difficult using a variety of techniques. To efficiently capture endosymbiont DNA for studies that examine the biology of symbiosis, we devised a parallel strategy to an earlier array-based method by creating a set of SureSelect™ (Agilent) 120-mer target enrichment RNA oligonucleotides ("baits") for solution hybrid selection. These were designed from Wolbachia complete and partial genome sequences in GenBank and were tiled across each genomic sequence with 60 bp overlap. Baits were filtered for homology against host genomes containing Wolbachia using BLAT and sequences with significant host homology were removed from the bait pool. Filarial parasite Brugia malayi DNA was used as a test case, as the complete sequence of both Wolbachia and its host are known. DNA eluted from capture was size selected and sequencing samples were prepared using the NEBNext® Sample Preparation Kit. One-third of a 50 nt paired-end sequencing lane on the HiSeq™ 2000 (Illumina) yielded 53 million reads and the entirety of the Wolbachia genome was captured. We then used the baits to isolate more than 97.1 % of the genome of a distantly related Wolbachia strain from the crustacean Armadillidium vulgare, demonstrating that the method can be used to enrich target DNA from unculturable microbes over large evolutionary distances.}, }
@article {pmid23482383, year = {2013}, author = {Mitchell, SO and Steinum, TM and Toenshoff, ER and Kvellestad, A and Falk, K and Horn, M and Colquhoun, DJ}, title = {'Candidatus Branchiomonas cysticola' is a common agent of epitheliocysts in seawater-farmed Atlantic salmon Salmo salar in Norway and Ireland.}, journal = {Diseases of aquatic organisms}, volume = {103}, number = {1}, pages = {35-43}, doi = {10.3354/dao02563}, pmid = {23482383}, issn = {0177-5103}, mesh = {Animals ; Aquaculture/*methods ; Bacterial Infections/epidemiology/microbiology/*veterinary ; Betaproteobacteria/*isolation &amp; purification ; DNA, Bacterial ; Disease Outbreaks/veterinary ; Fish Diseases/epidemiology/*microbiology ; Ireland/epidemiology ; Norway/epidemiology ; Prevalence ; *Salmo salar ; Skin Diseases, Bacterial/epidemiology/microbiology/*veterinary ; }, abstract = {The prevalence and geographical distribution of the recently described endosymbiont 'Candidatus Branchiomonas cysticola' in Atlantic salmon Salmo salar gill epithelial cell cysts was investigated in seawater-farmed fish suffering proliferative gill inflammation (PGI). To this end, we developed a specific and sensitive real-time PCR assay for detection of the bacterium. 'Ca. B. cysticola' was found to be highly prevalent in Atlantic salmon gills sampled over 7 yr and from 17 geographically distant seawater locations in Norway and Ireland. 'Ca. B. cysticola' was found in significantly greater quantities in fish with large numbers of epitheliocysts, and fluorescence in situ hybridization confirmed its localisation within cysts. 'Ca. Piscichlamydia salmonis', a bacterium previously linked to epitheliocysts, was identified at relatively low levels of infection, apparently independent of epitheliocyst prevalence. These results suggest that 'Ca. B. cysticola' is the main cyst-forming bacterium in seawater-farmed Atlantic salmon in the studied countries. Our results also suggest a relationship between load of 'Ca. B. cysticola' and extent of pathological changes. Taken together with a previously described association between epitheliocyst load and severity of PGI in Norwegian salmon, the results could indicate a role for 'Ca. B. cysticola' in gill diseases such as PGI.}, }
@article {pmid23475938, year = {2013}, author = {Driscoll, T and Gillespie, JJ and Nordberg, EK and Azad, AF and Sobral, BW}, title = {Bacterial DNA sifted from the Trichoplax adhaerens (Animalia: Placozoa) genome project reveals a putative rickettsial endosymbiont.}, journal = {Genome biology and evolution}, volume = {5}, number = {4}, pages = {621-645}, pmid = {23475938}, issn = {1759-6653}, support = {R01 AI017828/AI/NIAID NIH HHS/United States ; R01 AI059118/AI/NIAID NIH HHS/United States ; HHSN272200900040C/AI/NIAID NIH HHS/United States ; R01AI017828/AI/NIAID NIH HHS/United States ; R01AI59118/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/*genetics ; *Gene Transfer, Horizontal ; Genome ; Gram-Negative Bacteria/classification/genetics/isolation &amp; purification/physiology ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Placozoa/*genetics/*microbiology/physiology ; Rickettsiaceae/classification/*genetics/isolation &amp; purification/physiology ; *Symbiosis ; }, abstract = {Eukaryotic genome sequencing projects often yield bacterial DNA sequences, data typically considered as microbial contamination. However, these sequences may also indicate either symbiont genes or lateral gene transfer (LGT) to host genomes. These bacterial sequences can provide clues about eukaryote-microbe interactions. Here, we used the genome of the primitive animal Trichoplax adhaerens (Metazoa: Placozoa), which is known to harbor an uncharacterized Gram-negative endosymbiont, to search for the presence of bacterial DNA sequences. Bioinformatic and phylogenomic analyses of extracted data from the genome assembly (181 bacterial coding sequences [CDS]) and trace read archive (16S rDNA) revealed a dominant proteobacterial profile strongly skewed to Rickettsiales (Alphaproteobacteria) genomes. By way of phylogenetic analysis of 16S rDNA and 113 proteins conserved across proteobacterial genomes, as well as identification of 27 rickettsial signature genes, we propose a Rickettsiales endosymbiont of T. adhaerens (RETA). The majority (93%) of the identified bacterial CDS belongs to small scaffolds containing prokaryotic-like genes; however, 12 CDS were identified on large scaffolds comprised of eukaryotic-like genes, suggesting that T. adhaerens might have recently acquired bacterial genes. These putative LGTs may coincide with the placozoan's aquatic niche and symbiosis with RETA. This work underscores the rich, and relatively untapped, resource of eukaryotic genome projects for harboring data pertinent to host-microbial interactions. The nature of unknown (or poorly characterized) bacterial species may only emerge via analysis of host genome sequencing projects, particularly if these species are resistant to cell culturing, as are many obligate intracellular microbes. Our work provides methodological insight for such an approach.}, }
@article {pmid23475937, year = {2013}, author = {Williams, LE and Wernegreen, JJ}, title = {Sequence context of indel mutations and their effect on protein evolution in a bacterial endosymbiont.}, journal = {Genome biology and evolution}, volume = {5}, number = {3}, pages = {599-605}, pmid = {23475937}, issn = {1759-6653}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Ants/*microbiology/physiology ; Bacterial Proteins/*genetics ; Base Sequence ; DNA, Intergenic ; Enterobacteriaceae/classification/*genetics ; *Evolution, Molecular ; Genetic Variation ; *INDEL Mutation ; Microsatellite Repeats ; Molecular Sequence Data ; Phylogeny ; Selection, Genetic ; *Symbiosis ; }, abstract = {Indel mutations play key roles in genome and protein evolution, yet we lack a comprehensive understanding of how indels impact evolutionary processes. Genome-wide analyses enabled by next-generation sequencing can clarify the context and effect of indels, thereby integrating a more detailed consideration of indels with our knowledge of nucleotide substitutions. To this end, we sequenced Blochmannia chromaiodes, an obligate bacterial endosymbiont of carpenter ants, and compared it with the close relative, B. pennsylvanicus. The genetic distance between these species is small enough for accurate whole genome alignment but large enough to provide a meaningful spectrum of indel mutations. We found that indels are subjected to purifying selection in coding regions and even intergenic regions, which show a reduced rate of indel base pairs per kilobase compared with nonfunctional pseudogenes. Indels occur almost exclusively in repeat regions composed of homopolymers and multimeric simple sequence repeats, demonstrating the importance of sequence context for indel mutations. Despite purifying selection, some indels occur in protein-coding genes. Most are multiples of three, indicating selective pressure to maintain the reading frame. The deleterious effect of frameshift-inducing indels is minimized by either compensation from a nearby indel to restore reading frame or the indel's location near the 3'-end of the gene. We observed amino acid divergence exceeding nucleotide divergence in regions affected by frameshift-inducing indels, suggesting that these indels may either drive adaptive protein evolution or initiate gene degradation. Our results shed light on how indel mutations impact processes of molecular evolution underlying endosymbiont genome evolution.}, }
@article {pmid23475613, year = {2013}, author = {Ovrutsky, AR and Chan, ED and Kartalija, M and Bai, X and Jackson, M and Gibbs, S and Falkinham, JO and Iseman, MD and Reynolds, PR and McDonnell, G and Thomas, V}, title = {Cooccurrence of free-living amoebae and nontuberculous Mycobacteria in hospital water networks, and preferential growth of Mycobacterium avium in Acanthamoeba lenticulata.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {10}, pages = {3185-3192}, pmid = {23475613}, issn = {1098-5336}, support = {R01 AI089718/AI/NIAID NIH HHS/United States ; AI089718/AI/NIAID NIH HHS/United States ; }, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology ; *Biofilms ; Coculture Techniques ; Drinking Water/microbiology/parasitology ; Ecosystem ; Hartmannella/isolation &amp; purification/microbiology ; Hospitals ; Microbial Viability ; Mycobacterium avium/*growth &amp; development/isolation &amp; purification ; Nontuberculous Mycobacteria/growth &amp; development/*isolation &amp; purification ; *Water Microbiology ; *Water Supply ; }, abstract = {The incidence of lung and other diseases due to nontuberculous mycobacteria (NTM) is increasing. NTM sources include potable water, especially in households where NTM populate pipes, taps, and showerheads. NTM share habitats with free-living amoebae (FLA) and can grow in FLA as parasites or as endosymbionts. FLA containing NTM may form cysts that protect mycobacteria from disinfectants and antibiotics. We first assessed the presence of FLA and NTM in water and biofilm samples collected from a hospital, confirming the high prevalence of NTM and FLA in potable water systems, particularly in biofilms. Acanthamoeba spp. (genotype T4) were mainly recovered (8/17), followed by Hartmannella vermiformis (7/17) as well as one isolate closely related to the genus Flamella and one isolate only distantly related to previously described species. Concerning mycobacteria, Mycobacterium gordonae was the most frequently found isolate (9/17), followed by Mycobacterium peregrinum (4/17), Mycobacterium chelonae (2/17), Mycobacterium mucogenicum (1/17), and Mycobacterium avium (1/17). The propensity of Mycobacterium avium hospital isolate H87 and M. avium collection strain 104 to survive and replicate within various FLA was also evaluated, demonstrating survival of both strains in all amoebal species tested but high replication rates only in Acanthamoeba lenticulata. As A. lenticulata was frequently recovered from environmental samples, including drinking water samples, these results could have important consequences for the ecology of M. avium in drinking water networks and the epidemiology of disease due to this species.}, }
@article {pmid23472225, year = {2013}, author = {Siozios, S and Cestaro, A and Kaur, R and Pertot, I and Rota-Stabelli, O and Anfora, G}, title = {Draft Genome Sequence of the Wolbachia Endosymbiont of Drosophila suzukii.}, journal = {Genome announcements}, volume = {1}, number = {1}, pages = {}, pmid = {23472225}, issn = {2169-8287}, support = {MR/K001744/1/MRC_/Medical Research Council/United Kingdom ; }, abstract = {Wolbachia is one of the most successful and abundant symbiotic bacteria in nature, infecting more than 40% of the terrestrial arthropod species. Here we report the draft genome sequence of a novel Wolbachia strain named "wSuzi" that was retrieved from the genome sequencing of its host, the invasive pest Drosophila suzukii.}, }
@article {pmid23462112, year = {2013}, author = {Herren, JK and Paredes, JC and Schüpfer, F and Lemaitre, B}, title = {Vertical transmission of a Drosophila endosymbiont via cooption of the yolk transport and internalization machinery.}, journal = {mBio}, volume = {4}, number = {2}, pages = {}, pmid = {23462112}, issn = {2150-7511}, mesh = {Animals ; Drosophila melanogaster/*microbiology ; Egg Proteins/metabolism ; Endocytosis ; Fat Body/metabolism ; Female ; Hemolymph/microbiology ; Models, Biological ; Oocytes/microbiology/physiology ; Spiroplasma/*physiology ; *Symbiosis ; }, abstract = {UNLABELLED: Spiroplasma is a diverse bacterial clade that includes many vertically transmitted insect endosymbionts, including Spiroplasma poulsonii, a natural endosymbiont of Drosophila melanogaster. These bacteria persist in the hemolymph of their adult host and exhibit efficient vertical transmission from mother to offspring. In this study, we analyzed the mechanism that underlies their vertical transmission, and here we provide strong evidence that these bacteria use the yolk uptake machinery to colonize the germ line. We show that Spiroplasma reaches the oocyte by passing through the intercellular space surrounding the ovarian follicle cells and is then endocytosed into oocytes within yolk granules during the vitellogenic stages of oogenesis. Mutations that disrupt yolk uptake by oocytes inhibit vertical Spiroplasma transmission and lead to an accumulation of these bacteria outside the oocyte. Impairment of yolk secretion by the fat body results in Spiroplasma not reaching the oocyte and a severe reduction of vertical transmission. We propose a model in which Spiroplasma first interacts with yolk in the hemolymph to gain access to the oocyte and then uses the yolk receptor, Yolkless, to be endocytosed into the oocyte. Cooption of the yolk uptake machinery is a powerful strategy for endosymbionts to target the germ line and achieve vertical transmission. This mechanism may apply to other endosymbionts and provides a possible explanation for endosymbiont host specificity.<br><br>IMPORTANCE: Most insect species, including important disease vectors and crop pests, harbor vertically transmitted endosymbiotic bacteria. Studies have shown that many facultative endosymbionts, including Spiroplasma, confer protection against different classes of parasites on their hosts and therefore are attractive tools for the control of vector-borne diseases. The ability to be efficiently transmitted from females to their offspring is the key feature shaping associations between insects and their inherited endosymbionts, but to date, little is known about the mechanisms involved. In oviparous animals, yolk accumulates in developing eggs and serves to meet the nutritional demands of embryonic development. Here we show that Spiroplasma coopts the yolk transport and uptake machinery to colonize the germ line and ensure efficient vertical transmission. The uptake of yolk is a female germ line-specific feature and therefore an attractive target for cooption by endosymbionts that need to maintain high-fidelity maternal transmission.}, }
@article {pmid23460918, year = {2013}, author = {Hall-Mendelin, S and Allcock, R and Kresoje, N and van den Hurk, AF and Warrilow, D}, title = {Detection of arboviruses and other micro-organisms in experimentally infected mosquitoes using massively parallel sequencing.}, journal = {PloS one}, volume = {8}, number = {2}, pages = {e58026}, pmid = {23460918}, issn = {1932-6203}, mesh = {Aedes/*microbiology/*virology ; Animals ; Arbovirus Infections/genetics/*microbiology/*virology ; Arboviruses/*genetics/*isolation &amp; purification ; Base Sequence ; Genome, Viral/genetics ; High-Throughput Nucleotide Sequencing/*methods ; Humans ; RNA, Ribosomal, 16S/genetics ; Sheep ; Wolbachia/genetics ; }, abstract = {Human disease incidence attributed to arbovirus infection is increasing throughout the world, with effective control interventions limited by issues of sustainability, insecticide resistance and the lack of effective vaccines. Several promising control strategies are currently under development, such as the release of mosquitoes trans-infected with virus-blocking Wolbachia bacteria. Implementation of any control program is dependent on effective virus surveillance and a thorough understanding of virus-vector interactions. Massively parallel sequencing has enormous potential for providing comprehensive genomic information that can be used to assess many aspects of arbovirus ecology, as well as to evaluate novel control strategies. To demonstrate proof-of-principle, we analyzed Aedes aegypti or Aedes albopictus experimentally infected with dengue, yellow fever or chikungunya viruses. Random amplification was used to prepare sufficient template for sequencing on the Personal Genome Machine. Viral sequences were present in all infected mosquitoes. In addition, in most cases, we were also able to identify the mosquito species and mosquito micro-organisms, including the bacterial endosymbiont Wolbachia. Importantly, naturally occurring Wolbachia strains could be differentiated from strains that had been trans-infected into the mosquito. The method allowed us to assemble near full-length viral genomes and detect other micro-organisms without prior sequence knowledge, in a single reaction. This is a step toward the application of massively parallel sequencing as an arbovirus surveillance tool. It has the potential to provide insight into virus transmission dynamics, and has applicability to the post-release monitoring of Wolbachia in mosquito populations.}, }
@article {pmid23452267, year = {2013}, author = {von Dohlen, CD and Spaulding, U and Shields, K and Havill, NP and Rosa, C and Hoover, K}, title = {Diversity of proteobacterial endosymbionts in hemlock woolly adelgid (Adelges tsugae) (Hemiptera: Adelgidae) from its native and introduced range.}, journal = {Environmental microbiology}, volume = {15}, number = {7}, pages = {2043-2062}, doi = {10.1111/1462-2920.12102}, pmid = {23452267}, issn = {1462-2920}, mesh = {Animals ; *Biodiversity ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; *Introduced Species ; Japan ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; North America ; Proteobacteria/*classification/*genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Taiwan ; }, abstract = {Knowledge of intraspecific variation in symbioses may aid in understanding the ecology of widespread insects in different parts of their range. We investigated bacterial symbionts of Adelges tsugae, a pest of hemlocks in eastern North America introduced from Asia. Amplification, cloning, and sequencing of bacterial 16S rDNA, in situ hybridizations, and electron microscopy revealed that A. tsugae harbours up to five bacterial phylotypes, according to population. Three Gammaproteobacteria species are maternally transmitted. The first, designated 'Ca. Pseudomonas adelgestsugas' resides in the haemocoel, and was detected in all populations except Taiwan. The second phylotype, 'Ca. Serratia symbiotica', resides in bacteriocytes of populations on Tsuga sieboldii in Japan and in E. North America. The third phylotype, designated 'Ca. Annandia adelgestsuga', clustered within a lineage of several insect endosymbionts that included Buchnera aphidicola. It was detected in bacteriocytes in all populations, and in salivary glands of first instars. Two Betaproteobacteria phylotypes were detected in some Japanese T. sieboldii and eastern North America populations, and were observed only in salivary glands with no evidence of maternal transmission. Our results support the ideas that symbiont gain and loss has been volatile in adelgids, and that symbionts may help to trace the source of invasive species.}, }
@article {pmid23452253, year = {2013}, author = {Kuechler, SM and Gibbs, G and Burckhardt, D and Dettner, K and Hartung, V}, title = {Diversity of bacterial endosymbionts and bacteria-host co-evolution in Gondwanan relict moss bugs (Hemiptera: Coleorrhyncha: Peloridiidae).}, journal = {Environmental microbiology}, volume = {15}, number = {7}, pages = {2031-2042}, doi = {10.1111/1462-2920.12101}, pmid = {23452253}, issn = {1462-2920}, mesh = {Animals ; Australia ; Bacteria/*classification/*genetics ; *Biodiversity ; Electron Transport Complex IV/genetics ; Gammaproteobacteria/classification/genetics/ultrastructure ; Hemiptera/*classification/genetics/*microbiology ; Molecular Sequence Data ; New Zealand ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; South America ; Symbiosis ; }, abstract = {Many hemipterans are associated with symbiotic bacteria, which are usually found intracellularly in specific bacteriomes. In this study, we provide the first molecular identification of the bacteriome-associated, obligate endosymbiont in a Gondwanan relict insect taxon, the moss bugs (Hemiptera: Coleorrhyncha: Peloridiidae), which represents one of the oldest lineages within the Hemiptera. Endosymbiotic associations of fifteen species of the family were analysed, covering representatives from South America, Australia/Tasmania and New Zealand. Phylogenetic analysis based on four kilobases of 16S-23S rRNA gene fragments showed that the obligate endosymbiont of Peloridiidae constitute a so far unknown group of Gammaproteobacteria which is named here 'Candidatus Evansia muelleri'. They are related to the sternorrhynchous endosymbionts Candidatus Portiera and Candidatus Carsonella. Comparison of the primary-endosymbiont and host (COI + 28S rRNA) trees showed overall congruence indicating co-speciation the hosts and their symbionts. The distribution of the endosymbiont within the insect body and its transmission was studied using FISH. The endosymbionts were detected endocellularly in a pair of bacteriomes as well as in the 'symbiont ball' of the posterior pole of each developing oocyte. Furthermore, ultrastructural analysis of the Malpighian tubules revealed that most host nuclei are infected by an endosymbiotic, intranuclear bacterium that was determined as an Alphaproteobacterium of the genus Rickettsia.}, }
@article {pmid23451781, year = {2013}, author = {Keeling, PJ}, title = {The number, speed, and impact of plastid endosymbioses in eukaryotic evolution.}, journal = {Annual review of plant biology}, volume = {64}, number = {}, pages = {583-607}, doi = {10.1146/annurev-arplant-050312-120144}, pmid = {23451781}, issn = {1545-2123}, mesh = {*Biological Evolution ; Chloroplasts/*genetics/metabolism ; Cyanobacteria/genetics ; Eukaryota/*genetics ; Plastids/genetics/metabolism ; Protein Transport ; *Symbiosis ; }, abstract = {Plastids (chloroplasts) have long been recognized to have originated by endosymbiosis of a cyanobacterium, but their subsequent evolutionary history has proved complex because they have also moved between eukaryotes during additional rounds of secondary and tertiary endosymbioses. Much of this history has been revealed by genomic analyses, but some debates remain unresolved, in particular those relating to secondary red plastids of the chromalveolates, especially cryptomonads. Here, I examine several fundamental questions and assumptions about endosymbiosis and plastid evolution, including the number of endosymbiotic events needed to explain plastid diversity, whether the genetic contribution of the endosymbionts to the host genome goes far beyond plastid-targeted genes, and whether organelle origins are best viewed as a singular transition involving one symbiont or as a gradual transition involving a long line of transient food/symbionts. I also discuss a possible link between transporters and the evolution of protein targeting in organelle integration.}, }
@article {pmid23450193, year = {2013}, author = {Raymann, K and Bobay, LM and Doak, TG and Lynch, M and Gribaldo, S}, title = {A genomic survey of Reb homologs suggests widespread occurrence of R-bodies in proteobacteria.}, journal = {G3 (Bethesda, Md.)}, volume = {3}, number = {3}, pages = {505-516}, pmid = {23450193}, issn = {2160-1836}, mesh = {Bacterial Physiological Phenomena ; Bacterial Proteins/*genetics ; Databases, Genetic ; Evolution, Molecular ; *Genome, Bacterial ; Molecular Sequence Data ; Phylogeny ; Protein Structure, Secondary ; Proteobacteria/classification/*genetics/physiology ; Sequence Analysis, Protein ; Sequence Homology, Amino Acid ; Species Specificity ; Symbiosis ; Synteny ; }, abstract = {Bacteria and eukaryotes are involved in many types of interaction in nature, with important ecological consequences. However, the diversity, occurrence, and mechanisms of these interactions often are not fully known. The obligate bacterial endosymbionts of Paramecium provide their hosts with the ability to kill sensitive Paramecium strains through the production of R-bodies, highly insoluble coiled protein ribbons. R-bodies have been observed in a number of free-living bacteria, where their function is unknown. We have performed an exhaustive survey of genes coding for homologs of Reb proteins (R-body components) in complete bacterial genomes. We found that reb genes are much more widespread than previously thought, being present in representatives of major Proteobacterial subdivisions, including many free-living taxa, as well as taxa known to be involved in various kinds of interactions with eukaryotes, from mutualistic associations to pathogenicity. Reb proteins display very good conservation at the sequence level, suggesting that they may produce functional R-bodies. Phylogenomic analysis indicates that reb genes underwent a complex evolutionary history and allowed the identification of candidates potentially involved in R-body assembly, functioning, regulation, or toxicity. Our results strongly suggest that the ability to produce R-bodies is likely widespread in Proteobacteria. The potential involvement of R-bodies in as yet unexplored interactions with eukaryotes and the consequent ecological implications are discussed.}, }
@article {pmid23447524, year = {2013}, author = {Kabeya, Y and Miyagishima, SY}, title = {Chloroplast DNA replication is regulated by the redox state independently of chloroplast division in Chlamydomonas reinhardtii.}, journal = {Plant physiology}, volume = {161}, number = {4}, pages = {2102-2112}, pmid = {23447524}, issn = {1532-2548}, mesh = {Cell Nucleus/metabolism ; Chlamydomonas reinhardtii/*metabolism ; Chloroplasts/*metabolism ; *DNA Replication ; DNA, Chloroplast/biosynthesis/*metabolism ; DNA-Directed DNA Polymerase/metabolism ; Glutathione Disulfide ; Heterotrophic Processes ; Oxidation-Reduction ; Photosynthesis ; }, abstract = {Chloroplasts arose from a cyanobacterial endosymbiont and multiply by division. In algal cells, chloroplast division is regulated by the cell cycle so as to occur only once, in the S phase. Chloroplasts possess multiple copies of their own genome that must be replicated during chloroplast proliferation. In order to examine how chloroplast DNA replication is regulated in the green alga Chlamydomonas reinhardtii, we first asked whether it is regulated by the cell cycle, as is the case for chloroplast division. Chloroplast DNA is replicated in the light and not the dark phase, independent of the cell cycle or the timing of chloroplast division in photoautotrophic culture. Inhibition of photosynthetic electron transfer blocked chloroplast DNA replication. However, chloroplast DNA was replicated when the cells were grown heterotrophically in the dark, raising the possibility that chloroplast DNA replication is coupled with the reducing power supplied by photosynthesis or the uptake of acetate. When dimethylthiourea, a reactive oxygen species scavenger, was added to the photoautotrophic culture, chloroplast DNA was replicated even in the dark. In contrast, when methylviologen, a reactive oxygen species inducer, was added, chloroplast DNA was not replicated in the light. Moreover, the chloroplast DNA replication activity in both the isolated chloroplasts and nucleoids was increased by dithiothreitol, while it was repressed by diamide, a specific thiol-oxidizing reagent. These results suggest that chloroplast DNA replication is regulated by the redox state that is sensed by the nucleoids and that the disulfide bonds in nucleoid-associated proteins are involved in this regulatory activity.}, }
@article {pmid23440444, year = {2013}, author = {Robert, CA and Frank, DL and Leach, KA and Turlings, TC and Hibbard, BE and Erb, M}, title = {Direct and indirect plant defenses are not suppressed by endosymbionts of a specialist root herbivore.}, journal = {Journal of chemical ecology}, volume = {39}, number = {4}, pages = {507-515}, pmid = {23440444}, issn = {1573-1561}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Coleoptera/drug effects/growth &amp; development/*physiology ; Gene Expression Regulation, Plant ; Herbivory/drug effects ; Larva/physiology ; Nematoda/drug effects/physiology ; Plant Roots/chemistry/metabolism/microbiology ; Polycyclic Sesquiterpenes ; Sesquiterpenes/chemistry/pharmacology ; Symbiosis/drug effects ; Volatile Organic Compounds/chemistry/metabolism ; Wolbachia/drug effects/isolation &amp; purification ; Zea mays/chemistry/*metabolism/microbiology ; }, abstract = {Insect endosymbionts influence many important metabolic and developmental processes of their host. It has been speculated that they may also help to manipulate and suppress plant defenses to the benefit of herbivores. Recently, endosymbionts of the root herbivore Diabrotica virgifera virgifera have been reported to suppress the induction of defensive transcripts in maize roots, which may explain the finding of another study that once attacked plants become more susceptible to subsequent D. v. virgifera attack. To test this hypothesis, we cured D. v. virgifera from its major endosymbiont Wolbachia and tested whether endosymbiont-free individuals elicit different defense responses in maize roots. The presence of Wolbachia did not alter the induction of defense marker genes and resistance in a susceptible maize hybrid and a resistant line. Furthermore, attacked maize plants emitted the same amount of (E)-β-caryophyllene, a volatile signal that serves as foraging cue for both entomopathogenic nematodes and D. v. virgifera. Finally, the effectiveness of the entomopathogenic nematode Heterorhabditis bacteriophora to infest D. v. virgifera was not changed by curing the larvae from their endosymbionts. These results show that the defense mechanisms of maize are not affected by Wolbachia. Consequently, D. v. virgifera does not seem to derive any plant-defense mediated benefits from its major endosymbiont.}, }
@article {pmid23435889, year = {2013}, author = {Morse, SF and Bush, SE and Patterson, BD and Dick, CW and Gruwell, ME and Dittmar, K}, title = {Evolution, multiple acquisition, and localization of endosymbionts in bat flies (Diptera: Hippoboscoidea: Streblidae and Nycteribiidae).}, journal = {Applied and environmental microbiology}, volume = {79}, number = {9}, pages = {2952-2961}, pmid = {23435889}, issn = {1098-5336}, mesh = {Animals ; Bacterial Proteins/genetics ; Base Sequence ; Biological Evolution ; Chiroptera/*parasitology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Diptera/cytology/*microbiology ; Enterobacteriaceae/classification/*genetics/isolation &amp; purification ; Female ; Gammaproteobacteria/classification/genetics/isolation &amp; purification ; Geography ; In Situ Hybridization, Fluorescence ; Male ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Bat flies are a diverse clade of obligate ectoparasites on bats. Like most blood-feeding insects, they harbor endosymbiotic prokaryotes, but the origins and nature of these symbioses are still poorly understood. To expand the knowledge of bacterial associates in bat flies, the diversity and evolution of the dominant endosymbionts in six of eight nominal subfamilies of bat flies (Streblidae and Nycteribiidae) were studied. Furthermore, the localization of endosymbionts and their transmission across developmental stages within the family Streblidae were explored. The results show diverse microbial associates in bat flies, with at least four ancestral invasions of distantly related microbial lineages throughout bat fly evolution. Phylogenetic relationships support the presence of at least two novel symbiont lineages (here clades B and D), and extend the geographic and taxonomic range of a previously documented lineage ("Candidatus Aschnera chinzeii"; here clade A). Although these lineages show reciprocally monophyletic clusters with several bat fly host clades, their phylogenetic relationships generally do not reflect current bat fly taxonomy or phylogeny. However, within some endosymbiont clades, congruent patterns of symbiont-host divergence are apparent. Other sequences identified in this study fall into the widely distributed, highly invasive, insect-associated Arsenophonus lineage and may be the result of symbiont replacements and/or transient infections (here clade C). Vertical transmission of endosymbionts of clades B and D is supported by fluorescent signal (fluorescent in situ hybridization [FISH]) and microbial DNA detection across developmental stages. The fluorescent bacterial signal is consistently localized within structures resembling bacteriomes, although their anatomical position differs by host fly clade. In summary, the results suggest an obligate host-endosymbiont relationship for three of the four known symbiont clades associated with bat flies (clades A, B, and D).}, }
@article {pmid23435694, year = {2013}, author = {Rousseau-Gueutin, M and Huang, X and Higginson, E and Ayliffe, M and Day, A and Timmis, JN}, title = {Potential functional replacement of the plastidic acetyl-CoA carboxylase subunit (accD) gene by recent transfers to the nucleus in some angiosperm lineages.}, journal = {Plant physiology}, volume = {161}, number = {4}, pages = {1918-1929}, pmid = {23435694}, issn = {1532-2548}, mesh = {Acetyl-CoA Carboxylase/chemistry/*genetics/metabolism ; Amino Acid Sequence ; Campanulaceae/enzymology/genetics ; Cell Nucleus/*genetics ; Gene Transfer, Horizontal/*genetics ; Genes, Plant/genetics ; Introns/genetics ; Magnoliopsida/*enzymology/*genetics ; Molecular Sequence Data ; Plastids/*genetics ; Protein Subunits/chemistry/*genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Regulatory Sequences, Nucleic Acid/genetics ; Sequence Alignment ; }, abstract = {Eukaryotic cells originated when an ancestor of the nucleated cell engulfed bacterial endosymbionts that gradually evolved into the mitochondrion and the chloroplast. Soon after these endosymbiotic events, thousands of ancestral prokaryotic genes were functionally transferred from the endosymbionts to the nucleus. This process of functional gene relocation, now rare in eukaryotes, continues in angiosperms. In this article, we show that the chloroplastic acetyl-CoA carboxylase subunit (accD) gene that is present in the plastome of most angiosperms has been functionally relocated to the nucleus in the Campanulaceae. Surprisingly, the nucleus-encoded accD transcript is considerably smaller than the plastidic version, consisting of little more than the carboxylase domain of the plastidic accD gene fused to a coding region encoding a plastid targeting peptide. We verified experimentally the presence of a chloroplastic transit peptide by showing that the product of the nuclear accD fused to green fluorescent protein was imported in the chloroplasts. The nuclear gene regulatory elements that enabled the erstwhile plastidic gene to become functional in the nuclear genome were identified, and the evolution of the intronic and exonic sequences in the nucleus is described. Relocation and truncation of the accD gene is a remarkable example of the processes underpinning endosymbiotic evolution.}, }
@article {pmid23434798, year = {2013}, author = {Shoguchi, E and Tanaka, M and Takeuchi, T and Shinzato, C and Satoh, N}, title = {Probing a coral genome for components of the photoprotective scytonemin biosynthetic pathway and the 2-aminoethylphosphonate pathway.}, journal = {Marine drugs}, volume = {11}, number = {2}, pages = {559-570}, pmid = {23434798}, issn = {1660-3397}, mesh = {Aminoethylphosphonic Acid/chemistry/*metabolism ; Animals ; Anthozoa/*genetics ; Databases, Factual ; Gene Expression Regulation ; Genome ; Indoles/chemistry/*metabolism ; Molecular Structure ; Phenols/chemistry/*metabolism ; Phylogeny ; }, abstract = {Genome sequences of the reef-building coral, Acropora digitifera, have been decoded. Acropora inhabits an environment with intense ultraviolet exposure and hosts the photosynthetic endosymbiont, Symbiodinium. Acropora homologs of all four genes necessary for biosynthesis of the photoprotective cyanobacterial compound, shinorine, are present. Among metazoans, these genes are found only in anthozoans. To gain further evolutionary insights into biosynthesis of photoprotective compounds and associated coral proteins, we surveyed the Acropora genome for 18 clustered genes involved in cyanobacterial synthesis of the anti-UV compound, scytonemin, even though it had not previously been detected in corals. We identified candidates for only 6 of the 18 genes, including tyrP, scyA, and scyB. Therefore, it does not appear that Acropora digitifera can synthesize scytonemin independently. On the other hand, molecular phylogenetic analysis showed that one tyrosinase gene is an ortholog of vertebrate tyrosinase genes and that the coral homologs, scyA and scyB, are similar to bacterial metabolic genes, phosphonopyruvate (ppyr) decarboxylase and glutamate dehydrogenase (GDH), respectively. Further genomic searches for ppyr gene-related biosynthetic components indicate that the coral possesses a metabolic pathway similar to the bacterial 2-aminoethylphosphonate (AEP) biosynthetic pathway. The results suggest that de novo synthesis of carbon-phosphorus compounds is performed in corals.}, }
@article {pmid23433646, year = {2013}, author = {García-Guasch, L and Caro-Vadillo, A and Manubens-Grau, J and Carretón, E and Morchón, R and Simón, F and Kramer, LH and Montoya-Alonso, JA}, title = {Is Wolbachia participating in the bronchial reactivity of cats with heartworm associated respiratory disease?.}, journal = {Veterinary parasitology}, volume = {196}, number = {1-2}, pages = {130-135}, doi = {10.1016/j.vetpar.2013.01.060}, pmid = {23433646}, issn = {1873-2550}, mesh = {Animals ; Antibodies, Bacterial/blood ; Bronchoconstriction ; Cat Diseases/microbiology/parasitology/*pathology ; Cats ; Dirofilariasis/*microbiology/pathology ; Female ; Immunoglobulin G/blood ; Male ; Plethysmography ; Respiratory Tract Diseases/etiology/pathology/*veterinary ; Serologic Tests ; Wolbachia/*physiology ; }, abstract = {Heartworm associated respiratory disease is a pulmonary syndrome in cats that results from the vascular and parenchymal inflammatory response associated with the arrival and death of Dirofilaria immitis worms into the distal pulmonary arteries. This parasite harbors intracellular Wolbachia, an endosymbiont bacteria. The association between the parasite and the bacteria is obligatory. Some studies suggest the involvement of Wolbachia in the development of the inflammatory reaction and in the polarization of the host immune response against the parasite. Barometric whole-body plethysmography is a non-invasive pulmonary function test that allows a dynamic study of breathing patterns and is useful to study airway disease and the response to different treatments. The aim of this prospective non-blinded study was to compare the influence of Wolbachia upon the respiratory function variables in a population of cats seropositive to D. immitis by use of Barometric whole-body plethysmography. Fourteen seropositive cats to Wolbachia and eight seronegative cats were put into the plethysmograph chamber and different respiratory variables were measured. The results were analyzed and compared between the two groups of animals. Significant differences were found for bronchoconstriction index variables PAU (pause) (P-value<0.05) and Penh (enhanced pause) (P-value<0.05). The results obtained in our study suggest that Wolbachia seems to produce a greater acute inflammatory response at bronchial, vascular and parenchymal level worsening the state of broncho-reactivity associated with the presence of seropositivity to D. immitis in cats.}, }
@article {pmid23428527, year = {2012}, author = {Muniaraj, M and Paramasivan, R and Sunish, IP and Arunachalam, N and Mariappan, T and Jerald Leo, SV and Dhananjeyan, KJ}, title = {Detection of Wolbachia endobacteria in Culex quinquefasciatus by Gimenez staining and confirmation by PCR.}, journal = {Journal of vector borne diseases}, volume = {49}, number = {4}, pages = {258-261}, pmid = {23428527}, issn = {0972-9062}, mesh = {Animals ; Culex/classification/*microbiology ; DNA, Bacterial/analysis/genetics ; Elephantiasis, Filarial/transmission ; Female ; Insect Vectors/microbiology ; Ovary/microbiology ; Polymerase Chain Reaction/*methods ; Staining and Labeling/*methods ; Wolbachia/*genetics/*isolation &amp; purification ; }, abstract = {BACKGROUND &amp; OBJECTIVES: Wolbachia are common intracellular bacteria that are found in arthropods and nematodes. These endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, including the induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-egg incompatibility. Since they can also move horizontally across species boundaries, Wolbachia is gaining importance in recent days as it could be used as a biological control agent to control vector mosquitoes or for paratransgenic approaches. However, the study of Wolbachia requires sophisticated techniques such as PCR and cell culture facilities which cannot be affordable for many laboratories where the diseases transmitted by arthropod vectors are common. Hence, it would be beneficial to develop a simple method to detect the presence of Wolbachia in arthropods.<br><br>METHOD: In this study, we described a method of staining Wolbachia endobacteria, present in the reproductive tissues of mosquitoes. The reliability of this method was compared with Gram staining and PCR based detection.<br><br>RESULTS: The microscopic observation of the Gimenez stained smear prepared from the teased ovary of wild caught and Wolbachia (+) Cx. quinquefasciatus revealed the presence of pink coloured pleomorphic cells of Wolbachia ranging from cocci, comma shaped cells to bacillus and chain forms. The ovaries of Wolbachia (-) cured mosquito did not show any cell. Although Gram's staining is a reliable differential staining for the other bacteria, the bacterial cells in the smears from the ovaries of wild caught mosquitoes did not take the stain properly and the cells were not clearly visible. The PCR amplified product from the pooled remains of wild caught and Wolbachia (+) Cx. quinquefasciatus showed clear banding, whereas, no banding was observed for the negative control (distilled water) and Wolbachia (-) Cx. quinquefasciatus.<br><br>The Gimenez staining technique applied, could be used to detect the members of the endobacteria Wolbachia easily, even in a simple laboratory without any special facilities or even in the field condition and for handling large number of samples in a shorter duration.}, }
@article {pmid23426010, year = {2013}, author = {Guan, SH and Gris, C and Cruveiller, S and Pouzet, C and Tasse, L and Leru, A and Maillard, A and Médigue, C and Batut, J and Masson-Boivin, C and Capela, D}, title = {Experimental evolution of nodule intracellular infection in legume symbionts.}, journal = {The ISME journal}, volume = {7}, number = {7}, pages = {1367-1377}, pmid = {23426010}, issn = {1751-7370}, mesh = {Bacterial Secretion Systems/genetics ; *Biological Evolution ; Fabaceae/*microbiology ; Mutation ; Plant Roots/microbiology ; Rhizobium/*genetics/pathogenicity ; Symbiosis/*genetics ; Virulence Factors/genetics ; }, abstract = {Soil bacteria known as rhizobia are able to establish an endosymbiosis with legumes that takes place in neoformed nodules in which intracellularly hosted bacteria fix nitrogen. Intracellular accommodation that facilitates nutrient exchange between the two partners and protects bacteria from plant defense reactions has been a major evolutionary step towards mutualism. Yet the forces that drove the selection of the late event of intracellular infection during rhizobium evolution are unknown. To address this question, we took advantage of the previous conversion of the plant pathogen Ralstonia solanacearum into a legume-nodulating bacterium that infected nodules only extracellularly. We experimentally evolved this draft rhizobium into intracellular endosymbionts using serial cycles of legume-bacterium cocultures. The three derived lineages rapidly gained intracellular infection capacity, revealing that the legume is a highly selective environment for the evolution of this trait. From genome resequencing, we identified in each lineage a mutation responsible for the extracellular-intracellular transition. All three mutations target virulence regulators, strongly suggesting that several virulence-associated functions interfere with intracellular infection. We provide evidence that the adaptive mutations were selected for their positive effect on nodulation. Moreover, we showed that inactivation of the type three secretion system of R. solanacearum that initially allowed the ancestral draft rhizobium to nodulate, was also required to permit intracellular infection, suggesting a similar checkpoint for bacterial invasion at the early nodulation/root infection and late nodule cell entry levels. We discuss our findings with respect to the spread and maintenance of intracellular infection in rhizobial lineages during evolutionary times.}, }
@article {pmid23421891, year = {2013}, author = {Kreizinger, Z and Hornok, S and Dán, A and Hresko, S and Makrai, L and Magyar, T and Bhide, M and Erdélyi, K and Hofmann-Lehmann, R and Gyuranecz, M}, title = {Prevalence of Francisella tularensis and Francisella-like endosymbionts in the tick population of Hungary and the genetic variability of Francisella-like agents.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {13}, number = {3}, pages = {160-163}, pmid = {23421891}, issn = {1557-7759}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Proteins/genetics ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Francisella/classification/genetics/*isolation &amp; purification ; Francisella tularensis/classification/genetics/isolation &amp; purification ; *Genetic Variation ; Genotype ; Gram-Negative Bacterial Infections/epidemiology/*microbiology/transmission ; Humans ; Hungary/epidemiology ; Ixodidae/*microbiology ; Lipoproteins/genetics ; Male ; Molecular Sequence Data ; Nymph ; Phylogeny ; Prevalence ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Tularemia/epidemiology/*microbiology/transmission ; }, abstract = {Several new taxa belonging to the genus Francisella have been described recently. The present study describes the prevalence of Francisella tularensis and Francisella-like endosymbionts (FLE) in ticks collected from Hungary from 2007 to 2009 and characterizes the genetic variability of FLEs. A total of 5402 Ixodid ticks (Ixodes ricinus, I. acuminatus, Dermacentor marginatus, D. reticulatus, Haemaphysalis inermis, H. concinna, H. punctata) were collected from vegetation and animal hosts and tested with conventional PCR, detecting the 16S rRNA and tul4 genes. F. tularensis ssp. holarctica was found in 2 pools of H. concinna and 1 pool of D. reticulatus, both representing minimum prevalence (calculated with 1 infected tick per pool) of 0.27% whereas the sequences of a FLE were detected in 11 pools of D. reticulatus showing a minimum prevalence of 3%. Although the tul4 gene sequence of this FLE was identical to all Hungarian and Portuguese FLEs found earlier, and the 16S rRNA sequence was also identical to the sequence of the endosymbiont of D. reticulatus described in Bulgaria, these 16S rRNA gene coding sequences differed in 2 nucleotides from the one found earlier in this tick species in Hungary. This divergence may appear to be a minor difference between the sequences, potentially even resulting from a technical failure, but it could also indicate a significant difference stemming from the conservative genetic character of Francisellaceae. Thus, it raises a question about the number of FLE variants circulating in D. reticulatus in Europe and indicates the need for further data about the FLEs described in other parts of the continent and new FLE genotyping markers.}, }
@article {pmid23415850, year = {2013}, author = {Leydet, BF and Liang, FT}, title = {Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus).}, journal = {Ticks and tick-borne diseases}, volume = {4}, number = {3}, pages = {191-196}, pmid = {23415850}, issn = {1877-9603}, support = {R01 AI077733/AI/NIAID NIH HHS/United States ; AI077733/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Female ; Humans ; Louisiana/epidemiology ; Male ; Polymerase Chain Reaction ; Tick Infestations/epidemiology/parasitology/*veterinary ; Ursidae/*parasitology ; }, abstract = {There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens.}, }
@article {pmid23415475, year = {2013}, author = {Michelet, L and Bonnet, S and Madani, N and Moutailler, S}, title = {Discriminating Francisella tularensis and Francisella-like endosymbionts in Dermacentor reticulatus ticks: evaluation of current molecular techniques.}, journal = {Veterinary microbiology}, volume = {163}, number = {3-4}, pages = {399-403}, doi = {10.1016/j.vetmic.2013.01.014}, pmid = {23415475}, issn = {1873-2542}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Bacteriological Techniques/*standards ; Dermacentor/*microbiology ; France ; Francisella/*classification/genetics/isolation &amp; purification/*physiology ; Francisella tularensis/*classification/genetics/isolation &amp; purification/*physiology ; Lipoproteins/genetics ; *Phylogeny ; Polymerase Chain Reaction/standards ; Symbiosis ; }, abstract = {Francisella tularensis, the causative agent of tularemia, is commonly transmitted by ticks. To ensure accurate F. tularensis reporting rates in epidemiological surveys, specific discrimination between F. tularensis and Francisella-like tick endosymbionts (FLEs) is absolutely critical. Four molecular available techniques capable of distinguishing Francisella spp. were compared here for the first time in French Dermacentor reticulatus ticks in order to estimate their specificity as well as their ease and speed of use. Results showed that tul4 and fopA real-time PCR assays can easily and effectively discriminate between F. tularensis and FLEs in D. reticulatus. In addition, a high prevalence of FLEs in D. reticulatus collected in France was reported by the use of fopA real-time PCR assay (79%). Finally, phylogenetic analysis showed that FLEs isolated from D. reticulatus correspond to a well-defined group compared to FLEs originating from various tick species.}, }
@article {pmid23401955, year = {2012}, author = {Linthicum, KJ}, title = {Summary of the symposium Global Perspective on the Culex pipiens Complex in the 21st Century: The Interrelationship of Culex pipiens, quinquefasciatus, molestus and others.}, journal = {Journal of the American Mosquito Control Association}, volume = {28}, number = {4 Suppl}, pages = {152-155}, doi = {10.2987/8756-971X-28.4s.152}, pmid = {23401955}, issn = {8756-971X}, mesh = {Animals ; Arbovirus Infections/transmission ; Arboviruses/physiology ; Culex/*classification/genetics/*physiology/virology ; Humans ; Insect Vectors/*classification/genetics/*physiology/virology ; }, abstract = {A symposium on the mosquitoes in the Culex pipiens Complex (Pipiens Complex), including Cx. pipiens, Cx. quinquefasciatus, and Cx. molestus, invited 17 of the world's experts on this species Complex to explore the current state of knowledge on the systematic status, speciation, ecology, biology, vector competence, population genetics, endosymbionts, and role in disease transmission of these species in various parts of the world. A Foreword, Introduction, 14 full papers, 3 abstracts and this Summary are published in this special issue of the Journal of the American Mosquito Control Association. A summary of findings, overall conclusions, and research needs will be discussed in relation to mosquito control and interrupting disease transmission caused by these species.}, }
@article {pmid23398820, year = {2013}, author = {Kishore, SP and Stiller, JW and Deitsch, KW}, title = {Horizontal gene transfer of epigenetic machinery and evolution of parasitism in the malaria parasite Plasmodium falciparum and other apicomplexans.}, journal = {BMC evolutionary biology}, volume = {13}, number = {}, pages = {37}, pmid = {23398820}, issn = {1471-2148}, support = {R01 AI052390/AI/NIAID NIH HHS/United States ; T32 GM007739/GM/NIGMS NIH HHS/United States ; AI 52390/AI/NIAID NIH HHS/United States ; GM07739/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Apicomplexa/*genetics ; Bayes Theorem ; *Biological Evolution ; DNA, Protozoan/genetics ; Dictyostelium/genetics ; *Gene Transfer, Horizontal ; Histone Methyltransferases ; Histone-Lysine N-Methyltransferase/genetics ; Likelihood Functions ; Nematoda/genetics ; Parasites/genetics ; Phylogeny ; Plasmodium falciparum/*genetics ; Sequence Analysis, DNA ; }, abstract = {BACKGROUND: The acquisition of complex transcriptional regulatory abilities and epigenetic machinery facilitated the transition of the ancestor of apicomplexans from a free-living organism to an obligate parasite. The ability to control sophisticated gene expression patterns enabled these ancient organisms to evolve several differentiated forms, invade multiple hosts and evade host immunity. How these abilities were acquired remains an outstanding question in protistan biology.<br><br>RESULTS: In this work, we study SET domain bearing genes that are implicated in mediating immune evasion, invasion and cytoadhesion pathways of modern apicomplexans, including malaria parasites. We provide the first conclusive evidence of a horizontal gene transfer of a Histone H4 Lysine 20 (H4K20) modifier, Set8, from an animal host to the ancestor of apicomplexans. Set8 is known to contribute to the coordinated expression of genes involved in immune evasion in modern apicomplexans. We also show the likely transfer of a H3K36 methyltransferase (Ashr3 from plants), possibly derived from algal endosymbionts. These transfers appear to date to the transition from free-living organisms to parasitism and coincide with the proposed horizontal acquisition of cytoadhesion domains, the O-glycosyltransferase that modifies these domains, and the primary family of transcription factors found in apicomplexan parasites. Notably, phylogenetic support for these conclusions is robust and the genes clearly are dissimilar to SET sequences found in the closely related parasite Perkinsus marinus, and in ciliates, the nearest free-living organisms with complete genome sequences available.<br><br>CONCLUSIONS: Animal and plant sources of epigenetic machinery provide new insights into the evolution of parasitism in apicomplexans. Along with the horizontal transfer of cytoadhesive domains, O-linked glycosylation and key transcription factors, the acquisition of SET domain methyltransferases marks a key transitional event in the evolution to parasitism in this important protozoan lineage.}, }
@article {pmid23398778, year = {2013}, author = {Baldi, F and Gallo, M and Marchetto, D and Faleri, C and Maida, I and Fani, R}, title = {Manila clams from Hg polluted sediments of Marano and Grado lagoons (Italy) harbor detoxifying Hg resistant bacteria in soft tissues.}, journal = {Environmental research}, volume = {125}, number = {}, pages = {188-196}, doi = {10.1016/j.envres.2012.11.008}, pmid = {23398778}, issn = {1096-0953}, mesh = {Animals ; Bacteria/*genetics ; Base Sequence ; Bivalvia/*metabolism/*microbiology ; Cluster Analysis ; Computational Biology ; DNA Primers/genetics ; DNA, Bacterial/*genetics ; Environmental Monitoring/methods/*statistics &amp; numerical data ; Geologic Sediments/analysis ; Gills/metabolism/microbiology/ultrastructure ; Hepatopancreas/metabolism/microbiology ; In Situ Hybridization, Fluorescence ; Italy ; Mediterranean Sea ; Mercury/analysis/*pharmacokinetics ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Oxidoreductases/genetics ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {A mechanism of mercury detoxification has been suggested by a previous study on Hg bioaccumulation in Manila clams (Ruditapes philippinarum) in the polluted Marano and Grado lagoons and in this study we demonstrate that this event could be partly related to the detoxifying activities of Hg-resistant bacteria (MRB) harbored in clam soft tissues. Therefore, natural clams were collected in six stations during two different periods (winter and spring) from Marano and Grado Lagoons. Siphons, gills and hepatopancreas from acclimatized clams were sterile dissected to isolate MRB. These anatomical parts were glass homogenized or used for whole, and they were lying on a solid medium containing 5mgl(-1) HgCl2 and incubated at 30°C. A total of fourteen bacterial strains were isolated and were identified by 16S rDNA sequencing and analysis, revealing that strains were representative of eight bacterial genera, four of which were Gram-positive (Enterococcus, Bacillus, Jeotgalicoccus and Staphylococcus) and other four were Gram-negative (Stenotrophomonas, Vibrio, Raoultella and Enterobacter). Plasmids and merA genes were found and their sequences determined. Fluorescence in situ hybridization (FISH) technique shows the presence of Firmicutes, Actinobacteria and Gammaproteobacteria by using different molecular probes in siphon and gills. Bacterial clumps inside clam flesh were observed and even a Gram-negative endosymbiont was disclosed by transmission electronic microscope inside clam cells. Bacteria harbored in cavities of soft tissue have mercury detoxifying activity. This feature was confirmed by the determination of mercuric reductase in glass-homogenized siphons and gills.}, }
@article {pmid23398406, year = {2013}, author = {Bouchery, T and Lefoulon, E and Karadjian, G and Nieguitsila, A and Martin, C}, title = {The symbiotic role of Wolbachia in Onchocercidae and its impact on filariasis.}, journal = {Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases}, volume = {19}, number = {2}, pages = {131-140}, doi = {10.1111/1469-0691.12069}, pmid = {23398406}, issn = {1469-0691}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Filariasis/drug therapy ; Filaricides/therapeutic use ; Filarioidea/*microbiology ; Humans ; *Symbiosis ; Tetracycline/*therapeutic use ; Wolbachia/*drug effects/*physiology ; }, abstract = {Symbiotic associations between eukaryotes and microorganisms are frequently observed in nature, and range along the continuum between parasitism and mutualism. The genus Wolbachia contains well-known intracellular bacteria of arthropods that induce several reproductive phenotypes that benefit the transmission of the bacteria. Interestingly, Wolbachia bacteria have been found in the Onchocercidae, a family of filarial nematodes, including species that cause human filarial diseases, e.g. lymphatic filariasis and onchocerciasis. The endosymbiont is thought to be mutualistic in the Onchocercidae, and to provide essential metabolites to the filariae. Currently, Wolbachia bacteria are targets of antibiotic therapy with tetracyclines, which have profound effects on the development, viability and fertility of filarial parasites. This overview article presents the Onchocercidae and Wolbachia, and then discusses the origin and the nature of the symbiosis. It highlights the contribution of Wolbachia to the survival of the filariae and to the development of pathology. Finally, the infection control implications for filariases are debated. Potential directions for future research are also discussed.}, }
@article {pmid23383354, year = {2013}, author = {Chen, L and Zhu, C and Zhang, D}, title = {Naturally occurring incompatibilities between different Culex pipiens pallens populations as the basis of potential mosquito control measures.}, journal = {PLoS neglected tropical diseases}, volume = {7}, number = {1}, pages = {e2030}, pmid = {23383354}, issn = {1935-2735}, mesh = {Animals ; China ; Crosses, Genetic ; Culex/genetics/*microbiology/physiology ; Female ; Germ Cells/*microbiology ; Male ; Molecular Sequence Data ; Mosquito Control/*methods ; Reproduction ; Sequence Analysis, DNA ; Sexual Behavior ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Vector-borne diseases remain a threat to public health, especially in tropical countries. The incompatible insect technique has been explored as a potential control strategy for several important insect vectors. However, this strategy has not been tested in Culex pipiens pallens, the most prevalent mosquito species in China. Previous works used introgression to generate new strains that matched the genetic backgrounds of target populations while harboring a new Wolbachia endosymbiont, resulting in mating competitiveness and cytoplasmic incompatibility. The generation of these incompatible insects is often time-consuming, and the long-term stability of the newly created insect-Wolbachia symbiosis is uncertain. Considering the wide distribution of Cx. pipiens pallens and hence possible isolation of different populations, we sought to test for incompatibilities between natural populations and the possibility of exploiting these incompatibilities as a control strategy.<br><br>Three field populations were collected from three geographic locations in eastern China. Reciprocal cross results showed that bi-directional patterns of incompatibility existed between some populations. Mating competition experiments indicated that incompatible males could compete with cognate males in mating with females, leading to reduced overall fecundity. F1 offspring from incompatible crosses maintained their maternal crossing types. All three populations tested positive for Wolbachia. Removal of Wolbachia by tetracycline rendered matings between these populations fully compatible.<br><br>CONCLUSIONS/SIGNIFICANCE: Our findings indicate that naturally occurring patterns of cytoplasmic incompatibility between Cx. pipiens pallens populations can be the basis of a control strategy for this important vector species. The observed incompatibilities are caused by Wolbachia. More tests including field trials are warranted to evaluate the feasibility of this strategy as a supplement to other control measures.}, }
@article {pmid23379718, year = {2013}, author = {Merville, A and Venner, S and Henri, H and Vallier, A and Menu, F and Vavre, F and Heddi, A and Bel-Venner, MC}, title = {Endosymbiont diversity among sibling weevil species competing for the same resource.}, journal = {BMC evolutionary biology}, volume = {13}, number = {}, pages = {28}, pmid = {23379718}, issn = {1471-2148}, mesh = {Animals ; Ecosystem ; Female ; France ; Male ; Molecular Sequence Data ; Phylogeny ; *Quercus ; Rickettsia/classification/physiology ; Rickettsiaceae/classification/*physiology ; Spiroplasma/classification/*physiology ; *Symbiosis ; Weevils/classification/*microbiology/*physiology ; Wolbachia/classification/physiology ; }, abstract = {BACKGROUND: Whereas the impact of endosymbionts on the ecology of their hosts is well known in some insect species, the question of whether host communities are influenced by endosymbionts remains largely unanswered. Notably, the coexistence of host species competing with each other, which is expected to be stabilized by their ecological differences, could be facilitated by differences in their endosymbionts. Yet, the composition of endosymbiotic communities housed by natural communities of competing host species is still almost unknown. In this study, we started filling this gap by describing and comparing the bacterial endosymbiotic communities of four sibling weevil species (Curculio spp.) that compete with each other to lay eggs into oak acorns (Quercus spp.) and exhibit marked ecological differences.<br><br>RESULTS: All four species housed the primary endosymbiont Candidatus Curculioniphilus buchneri, yet each of these had a clearly distinct community of secondary endosymbionts, including Rickettsia, Spiroplasma, and two Wolbachia strains. Notably, three weevil species harbored their own predominant facultative endosymbiont and possessed the remaining symbionts at a residual infection level.<br><br>CONCLUSIONS: The four competing species clearly harbor distinct endosymbiotic communities. We discuss how such endosymbiotic communities could spread and keep distinct in the four insect species, and how these symbionts might affect the organization and species richness of host communities.}, }
@article {pmid23378531, year = {2013}, author = {Brinkmann, CR and Jensen, L and Dagnæs-Hansen, F and Holm, IE and Endo, Y and Fujita, T and Thiel, S and Jensenius, JC and Degn, SE}, title = {Mitochondria and the lectin pathway of complement.}, journal = {The Journal of biological chemistry}, volume = {288}, number = {12}, pages = {8016-8027}, pmid = {23378531}, issn = {1083-351X}, mesh = {Animals ; Blood Proteins/metabolism ; Complement C3/metabolism ; Complement C4/metabolism ; *Complement Pathway, Mannose-Binding Lectin ; Humans ; Interleukin-6/blood ; Lectins/genetics/metabolism ; Lipopolysaccharides/pharmacology ; Lung/immunology/pathology ; Mannose-Binding Lectin/metabolism ; Mannose-Binding Protein-Associated Serine Proteases/physiology ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mitochondria, Liver/*immunology/metabolism ; Protein Binding ; Rats ; Receptors, Pattern Recognition/metabolism ; }, abstract = {Mitochondria, the powerhouses of our cells, are remnants of a eubacterial endosymbiont. Notwithstanding the evolutionary time that has passed since the initial endosymbiotic event, mitochondria have retained many hallmarks of their eubacterial origin. Recent studies have indicated that during perturbations of normal homeostasis, such as following acute trauma leading to massive necrosis and release of mitochondria, the immune system might mistake symbiont for enemy and initiate an inappropriate immune response. The innate immune system is the first line of defense against invading microbial pathogens, and as such is the primary suspect in the recognition of mitochondria-derived danger-associated molecular patterns and initiation of an aberrant response. Conversely, innate immune mechanisms are also central to noninflammatory clearance of innocuous agents. Here we investigated the role of a central humoral component of innate immunity, the lectin pathway of complement, in recognition of mitochondria in vitro and in vivo. We found that the soluble pattern recognition molecules, mannan-binding lectin (MBL), L-ficolin, and M-ficolin, were able to recognize mitochondria. Furthermore, MBL in complex with MBL-associated serine protease 2 (MASP-2) was able to activate the lectin pathway and deposit C4 onto mitochondria, suggesting that these molecules are involved either in homeostatic clearance of mitochondria or in induction of untoward inflammatory reactions. We found that following mitochondrial challenge, C3 was consumed in vivo in the absence of overt inflammation, indicating a potential role of complement in noninflammatory clearance of mitochondria. Thus, we report here the first indication of involvement of the lectin pathway in mitochondrial immune handling.}, }
@article {pmid23371946, year = {2013}, author = {Ball, SG and Subtil, A and Bhattacharya, D and Moustafa, A and Weber, AP and Gehre, L and Colleoni, C and Arias, MC and Cenci, U and Dauvillée, D}, title = {Metabolic effectors secreted by bacterial pathogens: essential facilitators of plastid endosymbiosis?.}, journal = {The Plant cell}, volume = {25}, number = {1}, pages = {7-21}, pmid = {23371946}, issn = {1532-298X}, support = {T32 GM008629/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacterial Proteins/genetics/*metabolism ; Biological Evolution ; Carbon/metabolism ; Chlamydiales/enzymology/genetics/*physiology ; Computational Biology ; Cyanobacteria/genetics/*physiology ; Genome, Plant/genetics ; Glycogen/metabolism ; Host-Pathogen Interactions ; Isoamylase/genetics/metabolism ; Photosynthesis ; Phylogeny ; Plant Proteins/genetics ; Plants/genetics/*microbiology ; Plastids/enzymology/*genetics ; *Symbiosis ; }, abstract = {Under the endosymbiont hypothesis, over a billion years ago a heterotrophic eukaryote entered into a symbiotic relationship with a cyanobacterium (the cyanobiont). This partnership culminated in the plastid that has spread to forms as diverse as plants and diatoms. However, why primary plastid acquisition has not been repeated multiple times remains unclear. Here, we report a possible answer to this question by showing that primary plastid endosymbiosis was likely to have been primed by the secretion in the host cytosol of effector proteins from intracellular Chlamydiales pathogens. We provide evidence suggesting that the cyanobiont might have rescued its afflicted host by feeding photosynthetic carbon into a chlamydia-controlled assimilation pathway.}, }
@article {pmid23355305, year = {2013}, author = {Patiño-Navarrete, R and Moya, A and Latorre, A and Peretó, J}, title = {Comparative genomics of Blattabacterium cuenoti: the frozen legacy of an ancient endosymbiont genome.}, journal = {Genome biology and evolution}, volume = {5}, number = {2}, pages = {351-361}, pmid = {23355305}, issn = {1759-6653}, mesh = {Animals ; Bacteroidetes/genetics/metabolism ; Base Sequence ; Cockroaches/*genetics/microbiology ; *Evolution, Molecular ; Genome, Bacterial ; Metabolic Networks and Pathways/*genetics ; Nitrogen/metabolism ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Many insect species have established long-term symbiotic relationships with intracellular bacteria. Symbiosis with bacteria has provided insects with novel ecological capabilities, which have allowed them colonize previously unexplored niches. Despite its importance to the understanding of the emergence of biological complexity, the evolution of symbiotic relationships remains hitherto a mystery in evolutionary biology. In this study, we contribute to the investigation of the evolutionary leaps enabled by mutualistic symbioses by sequencing the genome of Blattabacterium cuenoti, primary endosymbiont of the omnivorous cockroach Blatta orientalis, and one of the most ancient symbiotic associations. We perform comparative analyses between the Blattabacterium cuenoti genome and that of previously sequenced endosymbionts, namely those from the omnivorous hosts the Blattella germanica (Blattelidae) and Periplaneta americana (Blattidae), and the endosymbionts harbored by two wood-feeding hosts, the subsocial cockroach Cryptocercus punctulatus (Cryptocercidae) and the termite Mastotermes darwiniensis (Termitidae). Our study shows a remarkable evolutionary stasis of this symbiotic system throughout the evolutionary history of cockroaches and the deepest branching termite M. darwiniensis, in terms of not only chromosome architecture but also gene content, as revealed by the striking conservation of the Blattabacterium core genome. Importantly, the architecture of central metabolic network inferred from the endosymbiont genomes was established very early in Blattabacterium evolutionary history and could be an outcome of the essential role played by this endosymbiont in the host's nitrogen economy.}, }
@article {pmid23354709, year = {2013}, author = {Parker, BJ and Spragg, CJ and Altincicek, B and Gerardo, NM}, title = {Symbiont-mediated protection against fungal pathogens in pea aphids: a role for pathogen specificity?.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {7}, pages = {2455-2458}, pmid = {23354709}, issn = {1098-5336}, mesh = {Animals ; Aphids/*microbiology/physiology ; Beauveria/*pathogenicity ; Enterobacteriaceae/*physiology ; Entomophthorales/*pathogenicity ; Microbial Interactions ; Peas/parasitology ; *Symbiosis ; }, abstract = {Here we show that a bacterial endosymbiont, Regiella insecticola, protects pea aphids (Acyrthosiphon pisum) from the aphid-specific fungal entomopathogen Zoophthora occidentalis but not from the generalist insect fungal pathogen Beauveria bassiana. This finding highlights the complex influence of fungi on the dynamics of this economically important agricultural pest.}, }
@article {pmid23349831, year = {2013}, author = {Elnagdy, S and Messing, S and Majerus, ME}, title = {Two strains of male-killing Wolbachia in a ladybird, Coccinella undecimpunctata, from a hot climate.}, journal = {PloS one}, volume = {8}, number = {1}, pages = {e54218}, pmid = {23349831}, issn = {1932-6203}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacterial Outer Membrane Proteins/genetics ; *Climate ; Coleoptera/drug effects/*microbiology ; Egypt ; Female ; Host-Pathogen Interactions/drug effects ; *Hot Temperature ; Jordan ; Male ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sex Factors ; Sex Ratio ; Species Specificity ; Tetracycline/pharmacology ; Wolbachia/classification/genetics/*physiology ; }, abstract = {Ladybirds are a hot-spot for the invasion of male-killing bacteria. These maternally inherited endosymbionts cause the death of male host embryos, to the benefit of female sibling hosts and the bacteria that they contain. Previous studies have shown that high temperatures can eradicate male-killers from ladybirds, leaving the host free from infection. Here we report the discovery of two maternally inherited sex ratio distorters in populations of a coccinellid, Coccinella undecimpunctata, from a hot lowland region of the Middle East. DNA sequence analysis indicates that the male killing is the result of infection by Wolbachia, that the trait is tetracycline sensitive, and that two distinct strains of Wolbachia co-occur within one beetle population. We discuss the implications of these findings for theories of male-killing and suggest avenues for future field-work on this system.}, }
@article {pmid23345457, year = {2013}, author = {Alves, JM and Serrano, MG and Maia da Silva, F and Voegtly, LJ and Matveyev, AV and Teixeira, MM and Camargo, EP and Buck, GA}, title = {Genome evolution and phylogenomic analysis of Candidatus Kinetoplastibacterium, the betaproteobacterial endosymbionts of Strigomonas and Angomonas.}, journal = {Genome biology and evolution}, volume = {5}, number = {2}, pages = {338-350}, pmid = {23345457}, issn = {1759-6653}, mesh = {Animals ; Betaproteobacteria/*genetics/metabolism ; Genome, Bacterial ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Symbiosis/*genetics ; Trypanosomatina/*genetics/growth &amp; development/metabolism/microbiology ; }, abstract = {It has been long known that insect-infecting trypanosomatid flagellates from the genera Angomonas and Strigomonas harbor bacterial endosymbionts (Candidatus Kinetoplastibacterium or TPE [trypanosomatid proteobacterial endosymbiont]) that supplement the host metabolism. Based on previous analyses of other bacterial endosymbiont genomes from other lineages, a stereotypical path of genome evolution in such bacteria over the duration of their association with the eukaryotic host has been characterized. In this work, we sequence and analyze the genomes of five TPEs, perform their metabolic reconstruction, do an extensive phylogenomic analyses with all available Betaproteobacteria, and compare the TPEs with their nearest betaproteobacterial relatives. We also identify a number of housekeeping and central metabolism genes that seem to have undergone positive selection. Our genome structure analyses show total synteny among the five TPEs despite millions of years of divergence, and that this lineage follows the common path of genome evolution observed in other endosymbionts of diverse ancestries. As previously suggested by cell biology and biochemistry experiments, Ca. Kinetoplastibacterium spp. preferentially maintain those genes necessary for the biosynthesis of compounds needed by their hosts. We have also shown that metabolic and informational genes related to the cooperation with the host are overrepresented amongst genes shown to be under positive selection. Finally, our phylogenomic analysis shows that, while being in the Alcaligenaceae family of Betaproteobacteria, the closest relatives of these endosymbionts are not in the genus Bordetella as previously reported, but more likely in the Taylorella genus.}, }
@article {pmid23342134, year = {2013}, author = {Alkhedir, H and Karlovsky, P and Vidal, S}, title = {Relationship between water soluble carbohydrate content, aphid endosymbionts and clonal performance of Sitobion avenae on cocksfoot cultivars.}, journal = {PloS one}, volume = {8}, number = {1}, pages = {e54327}, pmid = {23342134}, issn = {1932-6203}, mesh = {Animals ; Aphids/*microbiology/*physiology ; Dactylis/*growth &amp; development ; }, abstract = {Aphids feed on plant phloem sap, rich in sugars but poor in essential amino acids. However, sugars cause osmotic regulation problems for aphids, which they overcome by hydrolysing the sugars in their gut and polymerising the hydrolysis products into oligosaccharides, excreted with honeydew. Aphids harbour primary bacterial endosymbionts, which supply them with essential amino acids necessary for survival. They also harbour secondary (facultative) endosymbionts (sfS), some of which have a positive impact on life history traits, although it is not yet known whether they also play a role in providing effective tolerance to differing levels of water soluble carbohydrates (WSCs). We investigated the relationship between WSC content of cocksfoot cultivars and performance of clones of the English grain aphid Sitobion avenae F. We evaluated how clone genotype and their sfS modulate performance on these different cultivars. We therefore examined the performance of genetically defined clones of S. avenae, collected from different host plants, harbouring different sfS. The performance was tested on 10 Dactylis glomerata L. cultivars with varying WSC content. D. glomerata is known as a wild host plant for S. avenae and is also commercially planted. We found that high WSCs levels are responsible for the resistance of D. glomerata cultivars to specific S. avenae clones. The minimum level of WSCs conferring resistance to D. glomerata cultivars was 1.7% dw. Cultivars with a WSC content of 2.2% or higher were resistant to S. avenae and did not allow reproduction. Our results further indicate that sfS modulate to some extend host plant cultivar adaptation in S. avenae. This is the first study revealing the importance of WSCs for aphid performance. Cocksfoot cultivars with a high content of WSCs might be therefore considered for aphid control or used for resistance breeding in this and other grass species, including cereals.}, }
@article {pmid23337811, year = {2013}, author = {Achilles-Day, UE and Day, JG}, title = {Isolation of clonal cultures of endosymbiotic green algae from their ciliate hosts.}, journal = {Journal of microbiological methods}, volume = {92}, number = {3}, pages = {355-357}, doi = {10.1016/j.mimet.2013.01.007}, pmid = {23337811}, issn = {1872-8359}, mesh = {Chlorophyta/*physiology ; Microbiological Techniques/*methods ; Paramecium/*microbiology ; *Symbiosis ; }, abstract = {Using Paramecium bursaria as a model organism improved protocols have been developed to isolate clonal endosymbiotic algae. This involved micromanipulation of individual protists, rupturing to release endosymbionts followed by enrichment on complex media and a series of plating steps, under low light (PAR ~10μmol photons m(-2)s(-1)).}, }
@article {pmid23334948, year = {2013}, author = {Ahantarig, A and Trinachartvanit, W and Baimai, V and Grubhoffer, L}, title = {Hard ticks and their bacterial endosymbionts (or would be pathogens).}, journal = {Folia microbiologica}, volume = {58}, number = {5}, pages = {419-428}, pmid = {23334948}, issn = {1874-9356}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; *Biodiversity ; Ixodidae/*microbiology/physiology ; *Symbiosis ; }, abstract = {The symbiotic microorganisms of arthropod vectors are highly significant from several points of view, partly due to their possible roles in the transmission of pathogenic causative agents by blood-sucking vectors. Although ticks are well studied because of their significance to human health, novel microbial associations remain to be described. This review summarises several endosymbiotic bacterial species in hard ticks from various parts of the world, including Coxiella-, Francisella-, Rickettsia- and Arsenophonus-like symbionts as well as Candidatus Midichloria mitochondrii and Wolbachia. New methodologies for the isolation and characterization of tick-associated bacteria will, in turn, encourage new strategies of tick control by studying their endosymbionts.}, }
@article {pmid23333735, year = {2013}, author = {Gottschling, M and McLean, TI}, title = {New home for tiny symbionts: dinophytes determined as Zooxanthella are Peridiniales and distantly related to Symbiodinium.}, journal = {Molecular phylogenetics and evolution}, volume = {67}, number = {1}, pages = {217-222}, doi = {10.1016/j.ympev.2013.01.003}, pmid = {23333735}, issn = {1095-9513}, mesh = {Animals ; *Anthozoa ; Bayes Theorem ; Cluster Analysis ; DNA, Protozoan/genetics ; Dinoflagellida/*classification/genetics/physiology ; Likelihood Functions ; *Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Endosymbiotic dinophytes are diverse and are found in a large variety of aquatic partners. They are colloquially coined zooxanthellae, and knowledge about those dinophytes with a coral as partner (i.e., Symbiodinium) is extensive. However, Zooxanthella nutricula has been specifically described based on material isolated from radiolarians, and its phylogenetic position within the dinophyte tree is unclear at present. We isolated genomic DNA and sequenced the ribosomal RNA genes from an endosymbiotic dinophyte found in a radiolarian. In phylogenetic analyses, the endosymbiont was distantly related to Symbiodinium and the Suessiales, but clustered together with members of the Peridiniales. Specifically, it was the sister lineage of a small group, whose members host a diatom as endosymbiont (i.e., the dinotoms). Endosymbiosis is thus of multiple origin within the dinophytes, and more research is necessary to work out ecological and morphological character traits that are congruent to the DNA trees.}, }
@article {pmid23324387, year = {2013}, author = {Duplouy, A and Iturbe-Ormaetxe, I and Beatson, SA and Szubert, JM and Brownlie, JC and McMeniman, CJ and McGraw, EA and Hurst, GD and Charlat, S and O'Neill, SL and Woolfit, M}, title = {Draft genome sequence of the male-killing Wolbachia strain wBol1 reveals recent horizontal gene transfers from diverse sources.}, journal = {BMC genomics}, volume = {14}, number = {}, pages = {20}, pmid = {23324387}, issn = {1471-2164}, mesh = {Adenosine Triphosphatases/genetics ; Animals ; Bacterial Proteins/genetics ; Butterflies/microbiology ; *Gene Transfer, Horizontal ; Genome, Bacterial/*genetics ; Male ; Membrane Transport Proteins/genetics ; Molecular Sequence Annotation ; Phylogeny ; SEC Translocation Channels ; SecA Proteins ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {BACKGROUND: The endosymbiont Wolbachia pipientis causes diverse and sometimes dramatic phenotypes in its invertebrate hosts. Four Wolbachia strains sequenced to date indicate that the constitution of the genome is dynamic, but these strains are quite divergent and do not allow resolution of genome diversification over shorter time periods. We have sequenced the genome of the strain wBol1-b, found in the butterfly Hypolimnas bolina, which kills the male offspring of infected hosts during embyronic development and is closely related to the non-male-killing strain wPip from Culex pipiens.<br><br>RESULTS: The genomes of wBol1-b and wPip are similar in genomic organisation, sequence and gene content, but show substantial differences at some rapidly evolving regions of the genome, primarily associated with prophage and repetitive elements. We identified 44 genes in wBol1-b that do not have homologs in any previously sequenced strains, indicating that Wolbachia's non-core genome diversifies rapidly. These wBol1-b specific genes include a number that have been recently horizontally transferred from phylogenetically distant bacterial taxa. We further report a second possible case of horizontal gene transfer from a eukaryote into Wolbachia.<br><br>CONCLUSIONS: Our analyses support the developing view that many endosymbiotic genomes are highly dynamic, and are exposed and receptive to exogenous genetic material from a wide range of sources. These data also suggest either that this bacterial species is particularly permissive for eukaryote-to-prokaryote gene transfers, or that these transfers may be more common than previously believed. The wBol1-b-specific genes we have identified provide candidates for further investigations of the genomic bases of phenotypic differences between closely-related Wolbachia strains.}, }
@article {pmid23321084, year = {2012}, author = {Clark, EL and Daniell, TJ and Wishart, J and Hubbard, SF and Karley, AJ}, title = {How conserved are the bacterial communities associated with aphids? A detailed assessment of the Brevicoryne brassicae (Hemiptera: Aphididae) using 16S rDNA.}, journal = {Environmental entomology}, volume = {41}, number = {6}, pages = {1386-1397}, doi = {10.1603/EN12152}, pmid = {23321084}, issn = {1938-2936}, mesh = {Animals ; Aphids/*microbiology ; Biodiversity ; DNA, Bacterial/chemistry ; DNA, Ribosomal/chemistry ; Enterobacteriaceae/*classification/genetics/isolation &amp; purification ; Likelihood Functions ; Phylogeny ; Pseudomonas/*classification/genetics/isolation &amp; purification ; Sequence Analysis, DNA ; }, abstract = {Aphids harbor a community of bacteria that include obligate and facultative endosymbionts belonging to the Enterobacteriaceae along with opportunistic, commensal, or pathogenic bacteria. This study represents the first detailed analysis of the identity and diversity of the bacterial community associated with the cabbage aphid, Brevicoryne brassicae (L.). 16S rDNA sequence analysis revealed that the community of bacteria associated with B. brassicae was diverse, with at least four different bacterial community types detected among aphid lines, collected from widely dispersed sites in Northern Britain. The bacterial sequence types isolated from B. brassicae showed little similarity to any bacterial endosymbionts characterized in insects; instead, they were closely related to free-living extracellular bacterial species that have been isolated from the aphid gut or that are known to be present in the environment, suggesting that they are opportunistic bacteria transmitted between the aphid gut and the environment. To quantify variation in bacterial community between aphid lines, which was driven largely by differences in the proportions of two dominant bacterial orders, the Pseudomonales and the Enterobacteriales, we developed a novel real-time (Taqman) qPCR assay. By improving our knowledge of aphid microbial ecology, and providing novel molecular tools to examine the presence and function of the microbial community, this study forms the basis of further research to explore the influence of the extracellular bacterial community on aphid fitness, pest status, and susceptibility to control by natural enemies.}, }
@article {pmid23316697, year = {2013}, author = {Noguchi, F and Kawato, M and Yoshida, T and Fujiwara, Y and Fujikura, K and Takishita, K}, title = {A novel alveolate in bivalves with chemosynthetic bacteria inhabiting deep-sea methane seeps.}, journal = {The Journal of eukaryotic microbiology}, volume = {60}, number = {2}, pages = {158-165}, doi = {10.1111/jeu.12017}, pmid = {23316697}, issn = {1550-7408}, mesh = {Alveolata/*classification/genetics/*isolation &amp; purification ; Animals ; Bivalvia/*parasitology ; Cluster Analysis ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Epithelial Cells/parasitology ; Genes, rRNA ; In Situ Hybridization, Fluorescence ; Japan ; Molecular Sequence Data ; Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal, 18S/genetics ; Seawater/*microbiology/*parasitology ; Sequence Analysis, DNA ; }, abstract = {It has recently been unveiled that a wide variety of microbial eukaryotes (protists) occur in chemosynthetic ecosystems, such as hydrothermal vents and methane seeps. However, there is little knowledge regarding protists associated with endemic animals inhabiting these environments. In the present study, utilizing PCR techniques, we detected fragments of the small subunit ribosomal RNA gene (SSU rRNA gene) from a particular protist from gill tissues of a significant fraction of the vesicomyid clams Calyptogena soyoae and C. okutanii complex and of the mussel Bathymodiolus platifrons and B. japonicus, all of which harbor chemosynthetic endosymbiont bacteria and dominate methane seeps in Sagami Bay, Japan. Based on the phylogeny of SSU rRNA gene, the organism in question was shown to belong to Alveolata. It is noteworthy that this protist did not affiliate with any known alveolate group, although being deeply branched within the lineage of Syndiniales, for which the monophyly was constantly recovered, but not robustly supported. In addition, the protist detected using PCR followed by sequencing was localized within gill epithelial cells of B. platifrons with whole-mount fluorescence in situ hybridization. This protist may be an endoparasite or an endocommensal of Calyptogena spp. and Bathymodiolus spp., and possibly have physiological and ecological impacts on these bivalves.}, }
@article {pmid23316208, year = {2012}, author = {Tanaka, K and Hanaoka, M}, title = {The early days of plastid retrograde signaling with respect to replication and transcription.}, journal = {Frontiers in plant science}, volume = {3}, number = {}, pages = {301}, pmid = {23316208}, issn = {1664-462X}, abstract = {The plastid signal was originally defined as a pathway that informs the nucleus of the chloroplast status and results in the modulation of expression of nuclear-encoded plastid protein genes. However, the transfer of chloroplast genes into the nuclear genome is a prerequisite in this scheme, although it should not have been established during the very early phase of chloroplast evolution. We recently demonstrated in a primitive red alga that the plastid-derived Mg-protoporphyrin IX activates nuclear DNA replication (NDR) through the stabilization of a G1 cyclin, which coordinates the timing of organelle and NDR. This mechanism apparently does not involve any transcriptional regulation in the nucleus, and could have been established prior to gene transfer events. However, a retrograde signal mediating light-responsive gene expression may have been established alongside gene transfer, because essential light sensing and regulatory systems were originally incorporated into plant cells by the photosynthetic endosymbiont. In this short article, we discuss the origins, early days and evolution of the plastid retrograde signal(s).}, }
@article {pmid23315735, year = {2013}, author = {Jiang, ZF and Xia, F and Johnson, KW and Brown, CD and Bartom, E and Tuteja, JH and Stevens, R and Grossman, RL and Brumin, M and White, KP and Ghanim, M}, title = {Comparison of the genome sequences of "Candidatus Portiera aleyrodidarum" primary endosymbionts of the whitefly Bemisia tabaci B and Q biotypes.}, journal = {Applied and environmental microbiology}, volume = {79}, number = {5}, pages = {1757-1759}, pmid = {23315735}, issn = {1098-5336}, support = {P50 GM081892/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/chemistry/genetics ; Genome, Bacterial ; Halomonadaceae/classification/genetics/*isolation &amp; purification/*physiology ; Hemiptera/*microbiology ; Molecular Sequence Data ; *Symbiosis ; }, abstract = {"Candidatus Portiera aleyrodidarum" is the primary endosymbiont of whiteflies. We report two complete genome sequences of this bacterium from the worldwide invasive B and Q biotypes of the whitefly Bemisia tabaci. Differences in the two genome sequences may add insights into the complex differences in the biology of both biotypes.}, }
@article {pmid23308288, year = {2013}, author = {Xia, S and Zhang, Q and Zhu, H and Cheng, Y and Liu, G and Hu, Z}, title = {Systematics of a kleptoplastidal dinoflagellate, Gymnodinium eucyaneum Hu (Dinophyceae), and its cryptomonad endosymbiont.}, journal = {PloS one}, volume = {8}, number = {1}, pages = {e53820}, pmid = {23308288}, issn = {1932-6203}, mesh = {Biological Evolution ; Cell Nucleus/ultrastructure ; China ; Chloroplasts/ultrastructure ; Cryptophyta/*classification/genetics/ultrastructure ; DNA, Ribosomal/*classification/genetics ; Dinoflagellida/*classification/genetics/ultrastructure ; Phylogeny ; RNA, Ribosomal, 23S/*classification/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {New specimens of the kleptoplastidal dinoflagellate Gymnodinium eucyaneum Hu were collected in China. We investigated the systematics of the dinoflagellate and the origin of its endosymbiont based on light morphology and phylogenetic analyses using multiple DNA sequences. Cells were dorsoventrally flattened with a sharply acute hypocone and a hemispherical epicone. The confusion between G. eucyaneum and G. acidotum Nygaard still needs to be resolved. We found that the hypocone was conspicuously larger than the epicone in most G. eucyaneum cells, which differed from G. acidotum, but there were a few cells whose hypocone and epicone were of nearly the same size. In addition, there was only one site difference in the partial nuclear LSU rDNA sequences of a sample from Japan given the name G. acidotum and G. eucyaneum in the present study, which suggest that G. eucyaneum may be a synonym of G. acidotum. Spectroscopic analyses and phylogenetic analyses based on nucleomorph SSU rDNA sequences and chloroplast 23 s rDNA sequences suggested that the endosymbiont of G. eucyaneum was derived from Chroomonas (Cryptophyta), and that it was most closely related to C. coerulea Skuja. Moreover, the newly reported kleptoplastidal dinoflagellates G. myriopyrenoides and G. eucyaneum in our study were very similar, and the taxonomy of kleptoplastidal dinoflagellates was discussed.}, }
@article {pmid23308142, year = {2013}, author = {Ahmed, MZ and De Barro, PJ and Ren, SX and Greeff, JM and Qiu, BL}, title = {Evidence for horizontal transmission of secondary endosymbionts in the Bemisia tabaci cryptic species complex.}, journal = {PloS one}, volume = {8}, number = {1}, pages = {e53084}, pmid = {23308142}, issn = {1932-6203}, mesh = {Animals ; Bacteroidetes/*genetics/physiology ; Biological Evolution ; Enterobacteriaceae/*genetics/physiology ; Hemiptera/*genetics/*microbiology/physiology ; Phylogeny ; *Symbiosis ; Wolbachia/*genetics/physiology ; }, abstract = {Bemisia tabaci (Hemiptera: Aleyrodidae) is a globally distributed pest composed of at least 34 morphologically indistinguishable cryptic species. At least seven species of endosymbiont have been found infecting some or all members of the complex. The origin(s) of the associations between specific endosymbionts and their whitefly hosts is unknown. Infection is normally vertical, but horizontal transmission does occur and is one way for new infections to be introduced into individuals. The relationships between the different members of the cryptic species complex and the endosymbionts have not been well explored. In this study, the phylogenies of different cryptic species of the host with those of their endosymbionts were compared. Of particular interest was whether there was evidence for both coevolution and horizontal transmission. Congruence was observed for the primary endosymbiont, Portiera aleyrodidarum, and partial incongruence in the case of two secondary endosymbionts, Arsenophonus and Cardinium and incongruence for a third, Wolbachia. The patterns observed for the primary endosymbiont supported cospeciation with the host while the patterns for the secondary endosymbionts, and especially Wolbachia showed evidence of host shifts and extinctions through horizontal transmission rather than cospeciation. Of particular note is the observation of several very recent host shift events in China between exotic invader and indigenous members of the complex. These shifts were from indigenous members of the complex to the invader as well as from the invader to indigenous relatives.}, }
@article {pmid23308034, year = {2012}, author = {de Crécy-Lagard, V and Marck, C and Grosjean, H}, title = {Decoding in Candidatus Riesia pediculicola, close to a minimal tRNA modification set?.}, journal = {Trends in cell &amp; molecular biology}, volume = {7}, number = {}, pages = {11-34}, pmid = {23308034}, issn = {0972-8449}, support = {R01 GM070641/GM/NIGMS NIH HHS/United States ; }, abstract = {A comparative genomic analysis of the recently sequenced human body louse unicellular endosymbiont Candidatus Riesia pediculicola with a reduced genome (582 Kb), revealed that it is the only known organism that might have lost all post-transcriptional base and ribose modifications of the tRNA body, retaining only modifications of the anticodon-stem-loop essential for mRNA decoding. Such a minimal tRNA modification set was not observed in other insect symbionts or in parasitic unicellular bacteria, such as Mycoplasma genitalium (580 Kb), that have also evolved by considerably reducing their genomes. This could be an example of a minimal tRNA modification set required for life, a question that has been at the center of the field for many years, especially for understanding the emergence and evolution of the genetic code.}, }
@article {pmid23305819, year = {2013}, author = {Matsunaga, M and Takahashi, Y and Yui-Kurino, R and Mikami, T and Kubo, T}, title = {Evolutionary aspects of a unique internal mitochondrial targeting signal in nuclear-migrated rps19 of sugar beet (Beta vulgaris L.).}, journal = {Gene}, volume = {517}, number = {1}, pages = {19-26}, doi = {10.1016/j.gene.2012.12.099}, pmid = {23305819}, issn = {1879-0038}, mesh = {Amino Acid Sequence ; Beta vulgaris/*metabolism ; *Biological Evolution ; Cell Nucleus/*genetics ; Cloning, Molecular ; DNA, Mitochondrial/genetics ; Genome, Plant ; Mitochondria/genetics/*metabolism ; Mitochondrial Membranes/metabolism ; Molecular Sequence Data ; Phylogeny ; Ribosomal Proteins/genetics/*metabolism ; Sequence Homology, Amino Acid ; Tobacco/*metabolism ; }, abstract = {The endosymbiotic theory postulates that many genes migrated from endosymbionts to the nuclear genomes of their hosts. Some migrated genes lack presequences directing proteins to mitochondria, and their mitochondrial targeting signals appear to be inscribed in the core coding regions as internal targeting signals (ITSs). ITSs may have evolved after sequence transfer to nuclei or ITSs may have pre-existed before sequence transfer. Here, we report the molecular cloning of a sugar beet gene for ribosomal protein S19 (Rps19; the first letter is capitalized when the gene is a nuclear gene). We show that sugar beet Rps19 (BvRps19) is an ITS-type gene. Based on amino-acid sequence comparison, dicotyledonous rps19s (the first letter is lower-cased when the gene is a mitochondrial gene), such as tobacco rps19 (Ntrps19), resemble an ancestral form of BvRps19. We investigated whether differences in amino-acid sequences between BvRps19 and Ntrps19 were involved in ITS evolution. Analyses of the intracellular localization of chimaeric GFP-fusion proteins that were transiently expressed in Welsh onion cells showed that Ntrps19-gfp was not localized in mitochondria. When several BvRps19-type amino acid substitutions, none of which was seen in any other angiosperm rps19, were introduced into Ntrps19-gfp, the modified Ntrps19-gfp became localized in mitochondria, supporting the notion that an ITS in BvRps19 evolved following sequence transfer to nuclei. Not all of these substitutions were seen in other ITS-type Rps19s, suggesting that the ITSs of Rps19 are diverse.}, }
@article {pmid23305669, year = {2013}, author = {Timmis, JN and Wang, D}, title = {Endosymbiotic evolution: the totalitarian nucleus is foiled again.}, journal = {Current biology : CB}, volume = {23}, number = {1}, pages = {R30-2}, doi = {10.1016/j.cub.2012.11.038}, pmid = {23305669}, issn = {1879-0445}, mesh = {Algal Proteins/*genetics ; Cell Nucleus/genetics ; Cercozoa/*genetics ; Cryptophyta/*genetics ; *Evolution, Molecular ; Genome ; Molecular Sequence Data ; Mosaicism ; Symbiosis/*genetics ; }, abstract = {DNA transfer between host cells and their endosymbionts has had a profound effect on the evolution of eukaryotic cells. A new sequencing study suggests that other forces may be equally important.}, }
@article {pmid23281650, year = {2012}, author = {Vinekar, R and Verma, C and Ghosh, I}, title = {Functional relevance of dynamic properties of Dimeric NADP-dependent Isocitrate Dehydrogenases.}, journal = {BMC bioinformatics}, volume = {13 Suppl 17}, number = {Suppl 17}, pages = {S2}, pmid = {23281650}, issn = {1471-2105}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*chemistry/classification/genetics ; Escherichia coli/enzymology ; Isocitrate Dehydrogenase/*chemistry/classification/genetics ; Molecular Sequence Data ; Mycobacterium tuberculosis/enzymology ; Phylogeny ; Protein Conformation ; Protein Multimerization ; Sequence Alignment ; Sequence Homology, Amino Acid ; }, abstract = {BACKGROUND: Isocitrate Dehydrogenases (IDHs) are important enzymes present in all living cells. Three subfamilies of functionally dimeric IDHs (subfamilies I, II, III) are known. Subfamily I are well-studied bacterial IDHs, like that of Escherischia coli. Subfamily II has predominantly eukaryotic members, but it also has several bacterial members, many being pathogens or endosymbionts. subfamily III IDHs are NAD-dependent. The eukaryotic-like subfamily II IDH from pathogenic bacteria such as Mycobacterium tuberculosis IDH1 are expected to have regulation similar to that of bacteria which use the glyoxylate bypass to survive starvation. Yet they are structurally different from IDHs of subfamily I, such as the E. coli IDH.<br><br>RESULTS: We have used phylogeny, structural comparisons and molecular dynamics simulations to highlight the similarity and differences between NADP-dependent dimeric IDHs with an emphasis on regulation. Our phylogenetic study indicates that an additional subfamily (IV) may also be present. Variation in sequence and structure in an aligned region may indicate functional importance concerning regulation in bacterial subfamily I IDHs. Correlation in movement of prominent loops seen from molecular dynamics may explain the adaptability and diversity of the predominantly eukaryotic subfamily II IDHs.<br><br>CONCLUSION: This study discusses possible regulatory mechanisms operating in various IDHs and implications for regulation of eukaryotic-like bacterial IDHs such as that of M. tuberculosis, which may provide avenues for intervention in disease.}, }
@article {pmid23296446, year = {2013}, author = {Boscaro, V and Petroni, G and Ristori, A and Verni, F and Vannini, C}, title = {"Candidatus Defluviella procrastinata" and "Candidatus Cyrtobacter zanobii", two novel ciliate endosymbionts belonging to the "Midichloria clade".}, journal = {Microbial ecology}, volume = {65}, number = {2}, pages = {302-310}, pmid = {23296446}, issn = {1432-184X}, mesh = {Alphaproteobacteria/*classification/genetics/isolation &amp; purification ; Bacterial Typing Techniques ; DNA, Bacterial/genetics ; Euplotes/*microbiology ; In Situ Hybridization, Fluorescence ; Paramecium/*microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The "Midichloria clade" is a recently discovered but well-established evolutionary lineage clustering inside the order Rickettsiales (Alphaproteobacteria). Not much is known about the biology of these organisms. The best characterized ones are endocellular symbionts of very different eukaryotic hosts, ranging from arthropods to protists. "Candidatus Midichloria mitochondrii", the most studied organism of the group, is an interesting object of study because of its unique capability to infect metazoans' mitochondria and the presence of flagellar genes in its genome. With this work, we aim at increasing the knowledge on the biodiversity and phylogeny of the "Midichloria group". We characterized according to the "full cycle rRNA approach" two novel endosymbionts of ciliated protozoa, i.e. Paramecium nephridiatum and Euplotes aediculatus. According to the nomenclatural rules for uncultivated prokaryotes, we established the novel taxa "Candidatus Defluviella procrastinata" and "Candidatus Cyrtobacter zanobii" for the two bacterial symbionts. Our phylogenetic analysis based on 16S rRNA gene sequences confirms that the evolutionary histories of "Midichloria clade" representatives and of their hosts are very different. This suggests that the symbiotic processes arose many times independently, perhaps through ways of transmission still not described in Rickettsiales.}, }
@article {pmid23288898, year = {2013}, author = {Elshahawi, SI and Trindade-Silva, AE and Hanora, A and Han, AW and Flores, MS and Vizzoni, V and Schrago, CG and Soares, CA and Concepcion, GP and Distel, DL and Schmidt, EW and Haygood, MG}, title = {Boronated tartrolon antibiotic produced by symbiotic cellulose-degrading bacteria in shipworm gills.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {110}, number = {4}, pages = {E295-304}, pmid = {23288898}, issn = {1091-6490}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; 1U01 TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/*biosynthesis/chemistry/pharmacology ; Base Sequence ; Biotransformation ; Bivalvia/*microbiology ; Boronic Acids/chemistry/metabolism ; Cellulose/metabolism ; DNA, Bacterial/genetics ; Evolution, Molecular ; Gammaproteobacteria/genetics/*metabolism ; Genome, Bacterial ; Gills/microbiology ; Macrolides/chemistry/metabolism ; Metabolic Networks and Pathways ; Molecular Structure ; Multigene Family ; Mutation ; Phylogeny ; Polyketide Synthases/genetics/metabolism ; Polyketides/chemistry/metabolism ; Symbiosis ; }, abstract = {Shipworms are marine wood-boring bivalve mollusks (family Teredinidae) that harbor a community of closely related Gammaproteobacteria as intracellular endosymbionts in their gills. These symbionts have been proposed to assist the shipworm host in cellulose digestion and have been shown to play a role in nitrogen fixation. The genome of one strain of Teredinibacter turnerae, the first shipworm symbiont to be cultivated, was sequenced, revealing potential as a rich source of polyketides and nonribosomal peptides. Bioassay-guided fractionation led to the isolation and identification of two macrodioloide polyketides belonging to the tartrolon class. Both compounds were found to possess antibacterial properties, and the major compound was found to inhibit other shipworm symbiont strains and various pathogenic bacteria. The gene cluster responsible for the synthesis of these compounds was identified and characterized, and the ketosynthase domains were analyzed phylogenetically. Reverse-transcription PCR in addition to liquid chromatography and high-resolution mass spectrometry and tandem mass spectrometry revealed the transcription of these genes and the presence of the compounds in the shipworm, suggesting that the gene cluster is expressed in vivo and that the compounds may fulfill a specific function for the shipworm host. This study reports tartrolon polyketides from a shipworm symbiont and unveils the biosynthetic gene cluster of a member of this class of compounds, which might reveal the mechanism by which these bioactive metabolites are biosynthesized.}, }
@article {pmid23284297, year = {2012}, author = {Richardson, MF and Weinert, LA and Welch, JJ and Linheiro, RS and Magwire, MM and Jiggins, FM and Bergman, CM}, title = {Population genomics of the Wolbachia endosymbiont in Drosophila melanogaster.}, journal = {PLoS genetics}, volume = {8}, number = {12}, pages = {e1003129}, pmid = {23284297}, issn = {1553-7404}, support = {/WT_/Wellcome Trust/United Kingdom ; WT094664/WT_/Wellcome Trust/United Kingdom ; BB/E012868/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bayes Theorem ; *Drosophila melanogaster/genetics/physiology ; Evolution, Molecular ; Genetic Variation ; Genome, Mitochondrial ; Haplotypes ; *Metagenomics ; Phylogeny ; *Symbiosis ; *Wolbachia/genetics/physiology ; }, abstract = {Wolbachia are maternally inherited symbiotic bacteria, commonly found in arthropods, which are able to manipulate the reproduction of their host in order to maximise their transmission. The evolutionary history of endosymbionts like Wolbachia can be revealed by integrating information on infection status in natural populations with patterns of sequence variation in Wolbachia and host mitochondrial genomes. Here we use whole-genome resequencing data from 290 lines of Drosophila melanogaster from North America, Europe, and Africa to predict Wolbachia infection status, estimate relative cytoplasmic genome copy number, and reconstruct Wolbachia and mitochondrial genome sequences. Overall, 63% of Drosophila strains were predicted to be infected with Wolbachia by our in silico analysis pipeline, which shows 99% concordance with infection status determined by diagnostic PCR. Complete Wolbachia and mitochondrial genomes show congruent phylogenies, consistent with strict vertical transmission through the maternal cytoplasm and imperfect transmission of Wolbachia. Bayesian phylogenetic analysis reveals that the most recent common ancestor of all Wolbachia and mitochondrial genomes in D. melanogaster dates to around 8,000 years ago. We find evidence for a recent global replacement of ancestral Wolbachia and mtDNA lineages, but our data suggest that the derived wMel lineage arose several thousand years ago, not in the 20th century as previously proposed. Our data also provide evidence that this global replacement event is incomplete and is likely to be one of several similar incomplete replacement events that have occurred since the out-of-Africa migration that allowed D. melanogaster to colonize worldwide habitats. This study provides a complete genomic analysis of the evolutionary mode and temporal dynamics of the D. melanogaster-Wolbachia symbiosis, as well as important resources for further analyses of the impact of Wolbachia on host biology.}, }
@article {pmid23279075, year = {2013}, author = {Sabree, ZL and Huang, CY and Okusu, A and Moran, NA and Normark, BB}, title = {The nutrient supplying capabilities of Uzinura, an endosymbiont of armoured scale insects.}, journal = {Environmental microbiology}, volume = {15}, number = {7}, pages = {1988-1999}, doi = {10.1111/1462-2920.12058}, pmid = {23279075}, issn = {1462-2920}, mesh = {Amino Acids/metabolism ; Animals ; Flavobacteriaceae/classification/metabolism/*physiology ; Genome, Bacterial ; Hemiptera/*microbiology/physiology ; Molecular Sequence Data ; Oxidative Stress ; Phylogeny ; *Symbiosis ; }, abstract = {An emerging common physiological feature of plant sap-feeding insects is the presence of bacterial endosymbionts capable of providing essential nutrients to their host. These microbial partners are inviable outside of specialized host tissues, and therefore a cultivation-independent approach, namely high-throughput next-generation genome sequencing, can be used to characterize their gene content and metabolic potential. To this end, we sequenced the first complete genome of the obligate endosymbiont, Candidatus 'Uzinura diaspidicola', of armoured scale insects. At 263 431 bp, Uzinura has an extremely reduced genome that is composed largely of genes encoding enzymes involved in translation and amino acid biosynthesis. The tiny size of the Uzinura genome parallels that observed in some other insect endosymbionts. Despite this extreme genome reduction, the absence of a known obligate partner bacterial symbiont suggests that Uzinura alone can supply sufficient nutrients to its host.}, }
@article {pmid23267621, year = {2012}, author = {Telesnicki, MC and Ghersa, CM and Martínez-Ghersa, MA and Arneodo, JD}, title = {Molecular identification of the secondary endosymbiont Hamiltonella defensa in the rose-grain aphid Metopolophium dirhodum.}, journal = {Revista Argentina de microbiologia}, volume = {44}, number = {4}, pages = {255-258}, pmid = {23267621}, issn = {0325-7541}, mesh = {Animals ; Aphids/*microbiology ; Proteobacteria/*genetics ; Sequence Analysis, RNA ; *Symbiosis ; }, abstract = {This is the first report of the association between the rose-grain aphid Metopolophium dirhodum, a potentially important cereal pest and the facultative symbiont Hamiltonella defensa. The infection with this gamma-proteobacterium was determined by PCR in laboratory-reared and field-collected specimens of an Argentinian population of the aphid. Partial bacterial 16S, IGS and 23S rRNA genes were sequenced and compared to other available Hamiltonella sequences by phylogenetic analysis. the present study provides new information on previously unknown M. dirhodum microbiota.}, }
@article {pmid23266212, year = {2013}, author = {Daugbjerg, N and Jensen, MH and Hansen, PJ}, title = {Using nuclear-encoded LSU and SSU rDNA sequences to identify the eukaryotic endosymbiont in Amphisolenia bidentata (Dinophyceae).}, journal = {Protist}, volume = {164}, number = {3}, pages = {411-422}, doi = {10.1016/j.protis.2012.10.001}, pmid = {23266212}, issn = {1618-0941}, mesh = {Alveolata/classification/*genetics ; Animals ; Chloroplasts/genetics ; DNA, Ribosomal/*analysis ; Eukaryota/*classification/*genetics ; Indian Ocean ; Microscopy, Fluorescence ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; }, abstract = {The marine dinoflagellate Amphisolenia bidentata possesses complete intracellular symbionts of prokaryotic and eukaryotic origin. This was confirmed ultrastructurally little over 20 years ago when it was showed that the eukaryotic endosymbiont had a nucleus, a chloroplast and mitochondria. We collected Amphisolenia bidentata cells in the Indian Ocean and the identity of the eukaryotic endosymbionts was investigated using both microscopical and molecular methods. Individual specimens of Amphisolenia bidentata were identified by light microscopy and selected for single-cell PCR. Host and endosymbiont nuclear-encoded LSU and SSU rDNA sequences were determined by PCR cloning. Blast searches showed the endosymbiont LSU sequence to have affinity to Pelagophyceae, an algal class within Chromalveolata that also includes dinoflagellates. Since more SSU rDNA sequences from pelagophytes are available we performed a SSU based phylogeny of chromalveolates. The eukaryotic endosymbiont clustered within a clade comprising flagellated and coccoid pelagophytes whereas Amphisolenia bidentata formed a sister taxon to other dinophysioids. Molecular data therefore resolved the endosymbiont in A. bidentata being a pelagophyte and thus identified the ninth novel chloroplast type in dinoflagellates and a new species association. Based on sequence divergence estimates and phylogenetic inference the endosymbiont in A. bidentata likely represents an undescribed genus of pelagophytes.}, }
@article {pmid23262214, year = {2013}, author = {Sharma, R and Hoti, SL and Vasuki, V and Sankari, T and Meena, RL and Das, PK}, title = {Filamentation temperature-sensitive protein Z (FtsZ) of Wolbachia, endosymbiont of Wuchereria bancrofti: a potential target for anti-filarial chemotherapy.}, journal = {Acta tropica}, volume = {125}, number = {3}, pages = {330-338}, doi = {10.1016/j.actatropica.2012.12.004}, pmid = {23262214}, issn = {1873-6254}, mesh = {Albendazole/administration &amp; dosage ; Amino Acid Motifs ; Amino Acid Sequence ; Animals ; Anti-Infective Agents/administration &amp; dosage ; Bacterial Proteins/antagonists &amp; inhibitors/*genetics/*metabolism ; Cloning, Molecular ; Culex/microbiology ; Cytoskeletal Proteins/antagonists &amp; inhibitors/*genetics/*metabolism ; Humans ; India ; Larva/microbiology ; Molecular Sequence Data ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Wolbachia/drug effects/*genetics/*metabolism ; Wuchereria bancrofti/isolation &amp; purification/*microbiology ; }, abstract = {Lymphatic filariasis (LF) is a leading cause of morbidity in the tropical world. It is caused by the filarial parasites Wuchereria bancrofti, Brugia malayi and Brugia timori and transmitted by vector mosquitoes. Currently a programme for the elimination of LF, Global programme for Elimination of Lymphatic Filariasis (GPELF), is underway with the strategy of mass administration of single dose of diethylcarbamazine or ivermectin, in combination with an anthelmintic drug, albendazole. However, antifilarial drugs used in the programme are only microfilaricidal but not or only partially macrofilaricidal. Hence, there is a need to identify new targets for developing antifilarial drugs. Filarial parasites harbor rickettsial endosymbionts, Wolbachia sp., which play an important role in their biology and hence are considered as potential targets for antifilarial chemotherapy development. In this study, one of the cell division proteins of Wolbachia of the major lymphatic filarial parasite, W. bancrofti, viz., filamentation temperature-sensitive protein Z (FtsZ), was explored as a drug target. The gene coding for FtsZ protein was amplified from the genomic DNA of W. bancrofti, cloned and sequenced. The derived amino acid sequence of the gene revealed that FtsZ protein is 396 amino acids long and contained the tubulin motif (GGGTGTG) involved in GTP binding and the GTP hydrolyzing motif (NLDFAD). The FtsZ gene of endosymbiont showed limited sequence homology, but exhibited functional homology with β-tubulin of its host, W. bancrofti, as it had both the functional motifs and conserved amino acids that are critical for enzymatic activity. β-tubulin is the target for the anti-helminthic activity of albendazole and since FtsZ shares functional homology with, β-tubulin it may also be sensitive to albendazole. Therefore, the effect of albendazole was tested against Wolbachia occurring in mosquitoes instead of filarial parasites as the drug has lethal effect on the latter. Third instar larvae of Culex quinquefasciatus were treated with 0.25mg/ml of albendazole (test) or tetracycline (positive control) in the rearing medium for different intervals and tested for the presence of Wolbachia by FtsZ PCR. All the treated larvae were negative for the presence of the FtsZ band, whereas all the control larvae were positive. The findings of the study, thus indicated that FtsZ is sensitive to albendazole. In view of this albendazole appears to have dual targets; FtsZ in Wolbachia and β-tubulin in W. bancrofti. Further, the functional domain of the gene was assessed for polymorphism among recombinant clones representing 120 W. bancrofti parasites, prevalent across wide geographic areas of India and found to be highly conserved among them. Since it is highly conserved and plays an important role in Wolbachia cell division it appears to be a potential target for anti-filarial chemotherapy development.}, }
@article {pmid23248622, year = {2012}, author = {Thiel, V and Hügler, M and Blümel, M and Baumann, HI and Gärtner, A and Schmaljohann, R and Strauss, H and Garbe-Schönberg, D and Petersen, S and Cowart, DA and Fisher, CR and Imhoff, JF}, title = {Widespread occurrence of two carbon fixation pathways in tubeworm endosymbionts: lessons from hydrothermal vent associated tubeworms from the mediterranean sea.}, journal = {Frontiers in microbiology}, volume = {3}, number = {}, pages = {423}, pmid = {23248622}, issn = {1664-302X}, abstract = {Vestimentiferan tubeworms (siboglinid polychetes) of the genus Lamellibrachia are common members of cold seep faunal communities and have also been found at sedimented hydrothermal vent sites in the Pacific. As they lack a digestive system, they are nourished by chemoautotrophic bacterial endosymbionts growing in a specialized tissue called the trophosome. Here we present the results of investigations of tubeworms and endosymbionts from a shallow hydrothermal vent field in the Western Mediterranean Sea. The tubeworms, which are the first reported vent-associated tubeworms outside the Pacific, are identified as Lamellibrachia anaximandri using mitochondrial ribosomal and cytochrome oxidase I (COI) gene sequences. They harbor a single gammaproteobacterial endosymbiont. Carbon isotopic data, as well as the analysis of genes involved in carbon and sulfur metabolism indicate a sulfide-oxidizing chemoautotrophic endosymbiont. The detection of a hydrogenase gene fragment suggests the potential for hydrogen oxidation as alternative energy source. Surprisingly, the endosymbiont harbors genes for two different carbon fixation pathways, the Calvin-Benson-Bassham (CBB) cycle as well as the reductive tricarboxylic acid (rTCA) cycle, as has been reported for the endosymbiont of the vent tubeworm Riftia pachyptila. In addition to RubisCO genes we detected ATP citrate lyase (ACL - the key enzyme of the rTCA cycle) type II gene sequences using newly designed primer sets. Comparative investigations with additional tubeworm species (Lamellibrachia luymesi, Lamellibrachia sp. 1, Lamellibrachia sp. 2, Escarpia laminata, Seepiophila jonesi) from multiple cold seep sites in the Gulf of Mexico revealed the presence of acl genes in these species as well. Thus, our study suggests that the presence of two different carbon fixation pathways, the CBB cycle and the rTCA cycle, is not restricted to the Riftia endosymbiont, but rather might be common in vestimentiferan tubeworm endosymbionts, regardless of the habitat.}, }
@article {pmid23240612, year = {2013}, author = {Diekmann, Y and Pereira-Leal, JB}, title = {Evolution of intracellular compartmentalization.}, journal = {The Biochemical journal}, volume = {449}, number = {2}, pages = {319-331}, doi = {10.1042/BJ20120957}, pmid = {23240612}, issn = {1470-8728}, mesh = {*Biological Evolution ; *Cell Compartmentation ; Eukaryotic Cells/classification/*metabolism ; Intracellular Membranes/metabolism/ultrastructure ; Microscopy, Electron ; Organelles/metabolism/ultrastructure ; Prokaryotic Cells/classification/*metabolism ; Proteins/metabolism ; Symbiosis ; }, abstract = {Cells compartmentalize their biochemical functions in a variety of ways, notably by creating physical barriers that separate a compartment via membranes or proteins. Eukaryotes have a wide diversity of membrane-based compartments, many that are lineage- or tissue-specific. In recent years, it has become increasingly evident that membrane-based compartmentalization of the cytosolic space is observed in multiple prokaryotic lineages, giving rise to several types of distinct prokaryotic organelles. Endosymbionts, previously believed to be a hallmark of eukaryotes, have been described in several bacteria. Protein-based compartments, frequent in bacteria, are also found in eukaryotes. In the present review, we focus on selected intracellular compartments from each of these three categories, membrane-based, endosymbiotic and protein-based, in both prokaryotes and eukaryotes. We review their diversity and the current theories and controversies regarding the evolutionary origins. Furthermore, we discuss the evolutionary processes acting on the genetic basis of intracellular compartments and how those differ across the domains of life. We conclude that the distinction between eukaryotes and prokaryotes no longer lies in the existence of a compartmentalized cell plan, but rather in its complexity.}, }
@article {pmid23235470, year = {2012}, author = {Péréfarres, F and Thierry, M and Becker, N and Lefeuvre, P and Reynaud, B and Delatte, H and Lett, JM}, title = {Biological invasions of geminiviruses: case study of TYLCV and Bemisia tabaci in Reunion Island.}, journal = {Viruses}, volume = {4}, number = {12}, pages = {3665-3688}, pmid = {23235470}, issn = {1999-4915}, mesh = {Animals ; Begomovirus/classification/*pathogenicity ; *Disease Vectors ; Hemiptera/classification/*growth &amp; development/*virology ; Molecular Epidemiology ; Plant Diseases/*virology ; Reunion ; }, abstract = {In the last 20 years, molecular ecology approaches have proven to be extremely useful to identify and assess factors associated with viral emerging diseases, particularly in economically and socially important tropical crops such as maize (maize streak disease) and cassava (cassava mosaic disease). Molecular ecology approaches were applied in Reunion Island to analyze the epidemic of tomato yellow leaf curl disease, which has been affecting the island since the end of the 1990s. Before the invasive biotype B (currently known as Middle East-Asia Minor 1 cryptic species) of Bemisia tabaci spread across the world, Reunion Island (South West Indian Ocean) only hosted an indigenous biotype of B. tabaci, Ms (currently known as Indian Ocean cryptic species). Wild hybrids between invasive and indigenous species were subsequently characterized over multiple generations. Endosymbiont analysis of the hybrid population indicated that matings were non-random. Similarly, while no indigenous begomoviruses have ever been reported on Reunion Island, the two main strains of one of the most damaging and emerging plant viruses in the world, the Mild and Israel strains of the Tomato yellow leaf curl virus (TYLCV-Mld and TYLCV-IL), were introduced in 1997 and 2004 respectively. While these introductions extensively modified the agricultural landscape of Reunion Island, they also provided an invaluable opportunity to study the ecological and genetic mechanisms involved in biological invasion and competition.}, }
@article {pmid23224611, year = {2013}, author = {Corsaro, D and Müller, KD and Wingender, J and Michel, R}, title = {"Candidatus Mesochlamydia elodeae" (Chlamydiae: Parachlamydiaceae), a novel chlamydia parasite of free-living amoebae.}, journal = {Parasitology research}, volume = {112}, number = {2}, pages = {829-838}, pmid = {23224611}, issn = {1432-1955}, mesh = {Amoebozoa/*microbiology/ultrastructure ; Chlamydiales/*classification/*isolation &amp; purification/physiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genes, rRNA ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Protozoan/genetics ; RNA, Ribosomal/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {Vannella sp. isolated from waterweed Elodea sp. was found infected by a chlamydia-like organism. This organism behaves like a parasite, causing the death through burst of its host. Once the vannellae degenerated, the parasite was successfully kept in laboratory within a Saccamoeba sp. isolated from the same waterweed sample, which revealed in fine through electron microscopy to harbor two bacterial endosymbionts: the chlamydial parasite we introduce and another endosymbiont initially and naturally present in the host. Herein, we provide molecular-based identification of both the amoeba host and its two endosymbionts, with special focus on the chlamydia parasite. High sequence similarity values of the 18S rDNA permitted to assign the amoeba to the species Saccamoeba lacustris (Amoebozoa, Tubulinea). The bacterial endosymbiont naturally harbored by the host belonged to Sphingomonas koreensis (Alpha-Proteobacteria). The chlamydial parasite showed a strict specificity for Saccamoeba spp., being unable to infect a variety of other amoebae, including Acanthamoeba, and it was itself infected by a bacteriophage. Sequence similarity values of the 16S rDNA and phylogenetic analysis indicated that this strain is a new member of the family Parachlamydiaceae, for which we propose the name "Candidatus Mesochlamydia elodeae."}, }
@article {pmid23221610, year = {2012}, author = {Hopkins, JF and Spencer, DF and Laboissiere, S and Neilson, JA and Eveleigh, RJ and Durnford, DG and Gray, MW and Archibald, JM}, title = {Proteomics reveals plastid- and periplastid-targeted proteins in the chlorarachniophyte alga Bigelowiella natans.}, journal = {Genome biology and evolution}, volume = {4}, number = {12}, pages = {1391-1406}, pmid = {23221610}, issn = {1759-6653}, mesh = {Algal Proteins/chemistry/*metabolism ; Cell Nucleus/metabolism ; Cercozoa/*chemistry/metabolism ; Chlorophyll/biosynthesis ; Chloroplasts/metabolism ; Photosynthesis ; Phylogeny ; Protein Sorting Signals ; Protein Transport ; Proteome/*chemistry/metabolism ; Proteomics ; }, abstract = {Chlorarachniophytes are unicellular marine algae with plastids (chloroplasts) of secondary endosymbiotic origin. Chlorarachniophyte cells retain the remnant nucleus (nucleomorph) and cytoplasm (periplastidial compartment, PPC) of the green algal endosymbiont from which their plastid was derived. To characterize the diversity of nucleus-encoded proteins targeted to the chlorarachniophyte plastid, nucleomorph, and PPC, we isolated plastid-nucleomorph complexes from the model chlorarachniophyte Bigelowiella natans and subjected them to high-pressure liquid chromatography-tandem mass spectrometry. Our proteomic analysis, the first of its kind for a nucleomorph-bearing alga, resulted in the identification of 324 proteins with 95% confidence. Approximately 50% of these proteins have predicted bipartite leader sequences at their amino termini. Nucleus-encoded proteins make up >90% of the proteins identified. With respect to biological function, plastid-localized light-harvesting proteins were well represented, as were proteins involved in chlorophyll biosynthesis. Phylogenetic analyses revealed that many, but by no means all, of the proteins identified in our proteomic screen are of apparent green algal ancestry, consistent with the inferred evolutionary origin of the plastid and nucleomorph in chlorarachniophytes.}, }
@article {pmid23213446, year = {2012}, author = {Landmann, F and Bain, O and Martin, C and Uni, S and Taylor, MJ and Sullivan, W}, title = {Both asymmetric mitotic segregation and cell-to-cell invasion are required for stable germline transmission of Wolbachia in filarial nematodes.}, journal = {Biology open}, volume = {1}, number = {6}, pages = {536-547}, pmid = {23213446}, issn = {2046-6390}, abstract = {Parasitic filarial nematodes that belong to the Onchocercidae family live in mutualism with Wolbachia endosymbionts. We developed whole-mount techniques to follow the segregation patterns of Wolbachia through the somatic and germline lineages of four filarial species. These studies reveal multiple evolutionarily conserved mechanisms that are required for Wolbachia localization to the germline. During the initial embryonic divisions, Wolbachia segregate asymmetrically such that they concentrate in the posteriorly localized P(2) blastomere, a precursor to the adult germline and hypodermal lineages. Surprisingly, in the next division they are excluded from the germline precursor lineage. Rather, they preferentially segregate to the C blastomere, a source of posterior hypodermal cells. Localization to the germline is accomplished by a distinct mechanism in which Wolbachia invade first the somatic gonadal cells close to the ovarian distal tip cell, the nematode stem cell niche, from the hypodermis. This tropism is associated with a cortical F-actin disruption, suggesting an active engulfment. Significantly, germline invasion occurs only in females, explaining the lack of Wolbachia in the male germline. Once in the syncytial environment of the ovaries, Wolbachia rely on the rachis to multiply and disperse into the germ cells. The utilization of cell-to-cell invasion for germline colonization may indicate an ancestral mode of horizontal transfer that preceded the acquisition of the mutualism.}, }
@article {pmid23210448, year = {2013}, author = {Taylor, MJ and Voronin, D and Johnston, KL and Ford, L}, title = {Wolbachia filarial interactions.}, journal = {Cellular microbiology}, volume = {15}, number = {4}, pages = {520-526}, doi = {10.1111/cmi.12084}, pmid = {23210448}, issn = {1462-5822}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Filarioidea/*microbiology/physiology ; Survival Analysis ; *Symbiosis ; Wolbachia/drug effects/growth &amp; development/*physiology ; }, abstract = {Wolbachia pipientis is a widespread intracellular bacterial symbiont of arthropods and is common in insects. One of their more exotic and unexpected hosts is the filarial nematodes, notable for the parasites responsible for onchocerciasis (river blindness), lymphatic filariasis (elephantiasis) and dirofilariasis (heartworm). Wolbachia are only present in a subgroup of the filarial nematodes and do not extend to other groups of nematodes either parasitic or free-living. In the medically and veterinary important species that host Wolbachia, the symbiont has become an essential partner to key biological processes in the life of the nematode to the point where antibiotic elimination of the bacteria leads to a potent and effective anti-filarial drug treatment. We review the cellular and molecular basis of Wolbachia filarial interactions and highlight the key processes provided by the endosymbiont upon which the nematodes have become entirely dependent. This dependency is primarily restricted to periods of the lifecycle with heavy metabolic demands including growth and development of larval stages and embryogenesis in the adult female. Also, the longevity of filarial parasites is compromised following depletion of the symbiont, which for the first time has delivered a safe and effective treatment to kill adult parasites with antibiotics.}, }
@article {pmid23209223, year = {2012}, author = {Gutiérrez, G}, title = {Draft genome sequence of Methanobacterium formicicum DSM 3637, an Archaebacterium isolated from the methane producer amoeba Pelomyxa palustris.}, journal = {Journal of bacteriology}, volume = {194}, number = {24}, pages = {6967-6968}, pmid = {23209223}, issn = {1098-5530}, mesh = {Archamoebae/*microbiology ; Base Composition ; Base Sequence ; DNA, Archaeal/genetics ; *Genome, Archaeal ; Methane/biosynthesis ; Methanobacterium/*genetics/isolation &amp; purification ; Molecular Sequence Data ; Phylogeny ; RNA, Archaeal/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Here is reported the draft genome sequence of Methanobacterium formicicum DSM 3637, which was isolated from the methane-producing amoeba Pelomyxa palustris. This bacterium was determined to be an endosymbiont living in the cytoplasm of P. palustris and the source of methane; however, the global characteristics of its genome suggest a free-living lifestyle rather than an endosymbiotic one.}, }
@article {pmid23205679, year = {2013}, author = {Fan, Y and Thompson, JW and Dubois, LG and Moseley, MA and Wernegreen, JJ}, title = {Proteomic analysis of an unculturable bacterial endosymbiont (Blochmannia) reveals high abundance of chaperonins and biosynthetic enzymes.}, journal = {Journal of proteome research}, volume = {12}, number = {2}, pages = {704-718}, pmid = {23205679}, issn = {1535-3907}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/metabolism ; Animals ; Ants/metabolism/microbiology ; Bacterial Proteins/*isolation &amp; purification/metabolism ; Chromatography, Liquid ; Enterobacteriaceae/genetics/*metabolism ; Fatty Acids/metabolism ; Group I Chaperonins/*isolation &amp; purification/metabolism ; Insect Proteins/*isolation &amp; purification/metabolism ; Nucleotides/metabolism ; *Proteomics ; Sulfates/metabolism ; Symbiosis/physiology ; Tandem Mass Spectrometry ; }, abstract = {Many insect groups have coevolved with bacterial endosymbionts that live within specialized host cells. As a salient example, ants in the tribe Camponotini rely on Blochmannia, an intracellular bacterial mutualist that synthesizes amino acids and recycles nitrogen for the host. We performed a shotgun, label-free, LC/MS/MS quantitative proteomic analysis to investigate the proteome of Blochmannia associated with Camponotus chromaiodes. We identified more than 330 Blochmannia proteins, or 54% coverage of the predicted proteome, as well as 244 Camponotus proteins. Using the average intensity of the top 3 "best flier" peptides along with spiking of a surrogate standard at a known concentration, we estimated the concentration (fmol/μg) of those proteins with confident identification. The estimated dynamic range of Blochmannia protein abundance spanned 3 orders of magnitude and covered diverse functional categories, with particularly high representation of metabolism, information transfer, and chaperones. GroEL, the most abundant protein, totaled 6% of Blochmannia protein abundance. Biosynthesis of essential amino acids, fatty acids, and nucleotides, and sulfate assimilation had disproportionately high coverage in the proteome, further supporting a nutritional role of the symbiosis. This first quantitative proteomic analysis of an ant endosymbiont illustrates a promising approach to study the functional basis of intimate symbioses.}, }
@article {pmid23201678, year = {2012}, author = {Curtis, BA and Tanifuji, G and Burki, F and Gruber, A and Irimia, M and Maruyama, S and Arias, MC and Ball, SG and Gile, GH and Hirakawa, Y and Hopkins, JF and Kuo, A and Rensing, SA and Schmutz, J and Symeonidi, A and Elias, M and Eveleigh, RJ and Herman, EK and Klute, MJ and Nakayama, T and Oborník, M and Reyes-Prieto, A and Armbrust, EV and Aves, SJ and Beiko, RG and Coutinho, P and Dacks, JB and Durnford, DG and Fast, NM and Green, BR and Grisdale, CJ and Hempel, F and Henrissat, B and Höppner, MP and Ishida, K and Kim, E and Kořený, L and Kroth, PG and Liu, Y and Malik, SB and Maier, UG and McRose, D and Mock, T and Neilson, JA and Onodera, NT and Poole, AM and Pritham, EJ and Richards, TA and Rocap, G and Roy, SW and Sarai, C and Schaack, S and Shirato, S and Slamovits, CH and Spencer, DF and Suzuki, S and Worden, AZ and Zauner, S and Barry, K and Bell, C and Bharti, AK and Crow, JA and Grimwood, J and Kramer, R and Lindquist, E and Lucas, S and Salamov, A and McFadden, GI and Lane, CE and Keeling, PJ and Gray, MW and Grigoriev, IV and Archibald, JM}, title = {Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs.}, journal = {Nature}, volume = {492}, number = {7427}, pages = {59-65}, pmid = {23201678}, issn = {1476-4687}, support = {BB/G00885X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; /HHMI/Howard Hughes Medical Institute/United States ; }, mesh = {Algal Proteins/genetics/metabolism ; Alternative Splicing/genetics ; Cell Nucleus/*genetics ; Cercozoa/cytology/*genetics/metabolism ; Cryptophyta/cytology/*genetics/metabolism ; Cytosol/metabolism ; *Evolution, Molecular ; Gene Duplication/genetics ; Gene Transfer, Horizontal/genetics ; Genes, Essential/genetics ; Genome/*genetics ; Genome, Mitochondrial/genetics ; Genome, Plant/genetics ; Genome, Plastid/genetics ; Molecular Sequence Data ; *Mosaicism ; Phylogeny ; Protein Transport ; Proteome/genetics/metabolism ; Symbiosis/*genetics ; Transcriptome/genetics ; }, abstract = {Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote-eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. Both genomes have >21,000 protein genes and are intron rich, and B. natans exhibits unprecedented alternative splicing for a single-celled organism. Phylogenomic analyses and subcellular targeting predictions reveal extensive genetic and biochemical mosaicism, with both host- and endosymbiont-derived genes servicing the mitochondrion, the host cell cytosol, the plastid and the remnant endosymbiont cytosol of both algae. Mitochondrion-to-nucleus gene transfer still occurs in both organisms but plastid-to-nucleus and nucleomorph-to-nucleus transfers do not, which explains why a small residue of essential genes remains locked in each nucleomorph.}, }
@article {pmid23197592, year = {2013}, author = {Jackson, CJ and Gornik, SG and Waller, RF}, title = {A tertiary plastid gains RNA editing in its new host.}, journal = {Molecular biology and evolution}, volume = {30}, number = {4}, pages = {788-792}, doi = {10.1093/molbev/mss270}, pmid = {23197592}, issn = {1537-1719}, mesh = {Base Composition ; Codon ; Dinoflagellida/*genetics ; Molecular Sequence Data ; Plastids/genetics/*physiology ; *RNA Editing ; RNA, Messenger/genetics/metabolism ; Symbiosis/genetics ; }, abstract = {Dinoflagellates are known for their development of highly aberrant organelle genetic systems. Both their plastid and mitochondrial genomes are extremely reduced in gene number and rearranged into numerous unconventional genomic elements. Transcription processes are also elaborately modified including extensive RNA editing and trans-splicing. Some dinoflagellates have replaced their original plastid through serial endosymbiotic events. Karlodinium veneficum is such an example that now contains a haptophyte plastid. This tertiary plastid provides a case of a more conventional genetic system introduced into a cellular environment with a known penchant for genetic oddities. Here, we show that K. veneficum plastid transcripts undergo extensive substitutional editing. The substitution types are more diverse than those seen in most other plastids but are similar to those of dinoflagellate organelles. There is no evidence for RNA editing of plastid-encoded transcripts from extant haptophytes, suggesting that K. veneficum plastid editing developed after the uptake of the tertiary endosymbiont.}, }
@article {pmid23193123, year = {2013}, author = {Weldon, SR and Strand, MR and Oliver, KM}, title = {Phage loss and the breakdown of a defensive symbiosis in aphids.}, journal = {Proceedings. Biological sciences}, volume = {280}, number = {1751}, pages = {20122103}, pmid = {23193123}, issn = {1471-2954}, mesh = {Analysis of Variance ; Animals ; Aphids/*microbiology/physiology ; DNA Primers/genetics ; Enterobacteriaceae/*virology ; Genetic Fitness/*genetics ; *Podoviridae ; Population Dynamics ; Reproduction/physiology ; *Symbiosis ; Vicia faba ; Viral Proteins/genetics/metabolism ; }, abstract = {Terrestrial arthropods are often infected with heritable bacterial symbionts, which may themselves be infected by bacteriophages. However, what role, if any, bacteriophages play in the regulation and maintenance of insect-bacteria symbioses is largely unknown. Infection of the aphid Acyrthosiphon pisum by the bacterial symbiont Hamiltonella defensa confers protection against parasitoid wasps, but only when H. defensa is itself infected by the phage A. pisum secondary endosymbiont (APSE). Here, we use a controlled genetic background and correlation-based assays to show that loss of APSE is associated with up to sevenfold increases in the intra-aphid abundance of H. defensa. APSE loss is also associated with severe deleterious effects on aphid fitness: aphids infected with H. defensa lacking APSE have a significantly delayed onset of reproduction, lower weight at adulthood and half as many total offspring as aphids infected with phage-harbouring H. defensa, indicating that phage loss can rapidly lead to the breakdown of the defensive symbiosis. Our results overall indicate that bacteriophages play critical roles in both aphid defence and the maintenance of heritable symbiosis.}, }
@article {pmid23192453, year = {2012}, author = {Peredo, EL and Les, DH and King, UM and Benoit, LK}, title = {Extreme conservation of the psaA/psaB intercistronic spacer reveals a translational motif coincident with the evolution of land plants.}, journal = {Journal of molecular evolution}, volume = {75}, number = {5-6}, pages = {184-197}, pmid = {23192453}, issn = {1432-1432}, mesh = {Base Sequence ; *Conserved Sequence ; DNA, Intergenic/*chemistry ; Embryophyta/*genetics/metabolism ; *Evolution, Molecular ; *Genes, Chloroplast ; Molecular Sequence Data ; Nucleic Acid Conformation ; Nucleotide Motifs ; Photosystem I Protein Complex/*genetics ; Phylogeny ; Protein Biosynthesis ; RNA, Messenger/chemistry ; Sequence Alignment ; }, abstract = {Although chloroplast transcriptional and translational mechanisms were derived originally from prokaryote endosymbionts, chloroplasts retain comparatively few genes as a consequence of the overall transfer to the nucleus of functions associated formerly with prokaryotic genomes. Various modifications reflect other evolutionary shifts toward eukaryotic regulation such as posttranscriptional transcript cleavage with individually processed cistrons in operons and gene expression regulated by nuclear-encoded sigma factors. We report a notable exception for the psaA-psaB-rps14 operon of land plant (embryophyte) chloroplasts, where the first two cistrons are separated by a spacer region to which no significant role had been attributed. We infer an important function of this region, as indicated by the conservation of identical, structurally significant sequences across embryophytes and their ancestral protist lineages, which diverged some 0.5 billion years ago. The psaA/psaB spacers of embryophytes and their progenitors exhibit few sequence and length variants, with most modeled transcripts resolving the same secondary structure: a loop with projecting Shine-Dalgarno site and well-defined stem that interacts with adjacent coding regions to sequester the psaB start codon. Although many functions of the original endosymbiont have been usurped by nuclear genes or interactions, conserved functional elements of embryophyte psaA/psaB spacers provide compelling evidence that translation of psaB is regulated here by a cis-acting mechanism comparable to those common in prokaryotes. Modeled transcripts also indicate that spacer variants in some plants (e.g., aquatic genus Najas) potentially reflect ecological adaptations to facilitate temperature-regulated translation of psaB.}, }
@article {pmid23185779, year = {2012}, author = {Vega, IA and Dellagnola, FA and Hurst, JA and Godoy, MS and Castro-Vazquez, A}, title = {A study of chlorophyll-like and phycobilin pigments in the C endosymbiont of the apple-snail pomacea canaliculata.}, journal = {Biocell : official journal of the Sociedades Latinoamericanas de Microscopia Electronica ... et. al}, volume = {36}, number = {2}, pages = {47-55}, pmid = {23185779}, issn = {0327-9545}, mesh = {Animals ; Chlorophyll/*analysis ; Magnetic Resonance Spectroscopy ; Malus/*growth &amp; development/metabolism ; Phycobilins/*analysis ; Phycocyanin/metabolism ; Snails/*growth &amp; development/metabolism ; Spectrometry, Mass, Fast Atom Bombardment ; *Symbiosis ; }, abstract = {Pigments present in the brown-greenish C morph of an intracellular endosymbiont of Pomacea canaliculata were investigated. Acetone extracts of the endosymbiotic corpuscles showed an absorption spectrum similar to that of chlorophylls. Three fractions obtained from silica gel column chromatography of the acetone extracts (C(I), C(II), and C(III)), were studied by positive ion fast atom bombardment-mass spectrometry (FAB-MS) and hydrogen-nuclear magnetic resonance (H-NMR). Results indicated the presence of (1) a sterol in the yellow colored C(I) fraction; (2) a mixture ofpheophorbides a and b in the major green fraction, C(II); and (3) a modified pheophorbide a in the smaller green fraction, C(III). Aqueous extracts of the C endosymbiont did not show evidence of the occurrence of C-phycocyanin, allophycocyanin or phycoerithrin (light absorption, fluorescence emission, and electrophoresis of the protein moieties) while cyanobacterial cells (Nostoc sp.) showed evidence of C-phycocyanin and allophycocyanin. The possible phylogenetic and functional significance of the pigments present in the C endosymbiont is discussed.}, }
@article {pmid23185484, year = {2012}, author = {Osei-Poku, J and Han, C and Mbogo, CM and Jiggins, FM}, title = {Identification of Wolbachia strains in mosquito disease vectors.}, journal = {PloS one}, volume = {7}, number = {11}, pages = {e49922}, pmid = {23185484}, issn = {1932-6203}, support = {//Wellcome Trust/United Kingdom ; 092654//Wellcome Trust/United Kingdom ; WT094664/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; *Culicidae/microbiology/parasitology ; *Disease Vectors ; Elephantiasis, Filarial/genetics ; Humans ; *Insect Vectors/genetics/microbiology ; *Malaria/genetics/transmission ; Phylogeny ; RNA Viruses/pathogenicity ; *Wolbachia/isolation &amp; purification/pathogenicity ; }, abstract = {Wolbachia bacteria are common endosymbionts of insects, and some strains are known to protect their hosts against RNA viruses and other parasites. This has led to the suggestion that releasing Wolbachia-infected mosquitoes could prevent the transmission of arboviruses and other human parasites. We have identified Wolbachia in Kenyan populations of the yellow fever vector Aedes bromeliae and its relative Aedes metallicus, and in Mansonia uniformis and Mansonia africana, which are vectors of lymphatic filariasis. These Wolbachia strains cluster together on the bacterial phylogeny, and belong to bacterial clades that have recombined with other unrelated strains. These new Wolbachia strains may be affecting disease transmission rates of infected mosquito species, and could be transferred into other mosquito vectors as part of control programs.}, }
@article {pmid23185309, year = {2012}, author = {Leese, F and Brand, P and Rozenberg, A and Mayer, C and Agrawal, S and Dambach, J and Dietz, L and Doemel, JS and Goodall-Copstake, WP and Held, C and Jackson, JA and Lampert, KP and Linse, K and Macher, JN and Nolzen, J and Raupach, MJ and Rivera, NT and Schubart, CD and Striewski, S and Tollrian, R and Sands, CJ}, title = {Exploring Pandora's box: potential and pitfalls of low coverage genome surveys for evolutionary biology.}, journal = {PloS one}, volume = {7}, number = {11}, pages = {e49202}, pmid = {23185309}, issn = {1932-6203}, mesh = {Animals ; Bacteria/genetics ; Cell Nucleus/genetics ; Contig Mapping ; DNA/genetics ; DNA, Mitochondrial/genetics ; *Data Collection ; Databases, Genetic ; *Evolution, Molecular ; Gene Library ; Genes, Mitochondrial/genetics ; Genetic Markers ; Genome/*genetics ; Genome Size/genetics ; Genome, Mitochondrial/genetics ; Microsatellite Repeats/genetics ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; Viral Proteins/genetics ; }, abstract = {High throughput sequencing technologies are revolutionizing genetic research. With this "rise of the machines", genomic sequences can be obtained even for unknown genomes within a short time and for reasonable costs. This has enabled evolutionary biologists studying genetically unexplored species to identify molecular markers or genomic regions of interest (e.g. micro- and minisatellites, mitochondrial and nuclear genes) by sequencing only a fraction of the genome. However, when using such datasets from non-model species, it is possible that DNA from non-target contaminant species such as bacteria, viruses, fungi, or other eukaryotic organisms may complicate the interpretation of the results. In this study we analysed 14 genomic pyrosequencing libraries of aquatic non-model taxa from four major evolutionary lineages. We quantified the amount of suitable micro- and minisatellites, mitochondrial genomes, known nuclear genes and transposable elements and searched for contamination from various sources using bioinformatic approaches. Our results show that in all sequence libraries with estimated coverage of about 0.02-25%, many appropriate micro- and minisatellites, mitochondrial gene sequences and nuclear genes from different KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways could be identified and characterized. These can serve as markers for phylogenetic and population genetic analyses. A central finding of our study is that several genomic libraries suffered from different biases owing to non-target DNA or mobile elements. In particular, viruses, bacteria or eukaryote endosymbionts contributed significantly (up to 10%) to some of the libraries analysed. If not identified as such, genetic markers developed from high-throughput sequencing data for non-model organisms may bias evolutionary studies or fail completely in experimental tests. In conclusion, our study demonstrates the enormous potential of low-coverage genome survey sequences and suggests bioinformatic analysis workflows. The results also advise a more sophisticated filtering for problematic sequences and non-target genome sequences prior to developing markers.}, }
@article {pmid23183308, year = {2013}, author = {Martin, OY and Puniamoorthy, N and Gubler, A and Wimmer, C and Bernasconi, MV}, title = {Infections with Wolbachia, Spiroplasma, and Rickettsia in the Dolichopodidae and other Empidoidea.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {13}, number = {}, pages = {317-330}, doi = {10.1016/j.meegid.2012.11.005}, pmid = {23183308}, issn = {1567-7257}, mesh = {Animals ; DNA, Bacterial ; Diptera/*microbiology ; Male ; Molecular Sequence Data ; Phylogeny ; Rickettsia/classification/*genetics ; Spiroplasma/classification/*genetics ; Symbiosis ; Wolbachia/classification/*genetics ; }, abstract = {Vertically transmitted reproductive parasites are both extraordinarily widespread and diverse in their effects on their invertebrate hosts. In addition to causing skewed population sex ratios via male-killing or feminization, such bacteria can further cause cytoplasmic incompatibility or parthenogenesis. Previous surveys show that the microbes Wolbachia and Spiroplasma are common in some dipteran families, e.g. Drosophilidae or Scathophagidae, and are known to be heritable symbionts and affect reproduction in the Diptera. However, little is known of Rickettsia infections and detailed surveys targeting other Dipteran families are lacking. Here 329 samples of 247 species of Diptera belonging to the Dolichopodidae, Empididae, and Hybotidae (superfamily Empidoidea) are surveyed for the presence of the endosymbionts Wolbachia, Spiroplasma, and Rickettsia. The superfamily Empidoidea contains numerous species, which have been the targets of intense research concerning reproductive traits involved in sexual selection. 151 of the species (i.e. ca. 61%) screened here, including species from key genera such as Dolichopus, Poecilobothrus or Empis, harboured one or more symbionts. Reproductive parasites are thus also common in the Empidoidae, yet effects on hosts remain unclear. Potential endosymbiont-host interactions in this group would hence be worthy of further investigation.}, }
@article {pmid23178999, year = {2013}, author = {Kawafune, K and Sato, M and Toyooka, K and Nozaki, H}, title = {Ultrastructure of the rickettsial endosymbiont "MIDORIKO" in the green alga Carteria cerasiformis as revealed by high-pressure freezing and freeze-substitution fixation.}, journal = {Protoplasma}, volume = {250}, number = {4}, pages = {949-953}, pmid = {23178999}, issn = {1615-6102}, mesh = {Cell Membrane/chemistry/ultrastructure ; Cell Wall/chemistry/ultrastructure ; Chlorophyta/*microbiology/*ultrastructure ; Freeze Substitution/*methods ; Rickettsiaceae/chemistry/*ultrastructure ; Symbiosis ; Tissue Fixation/methods ; Tissue Preservation/methods ; }, abstract = {Bacterial endosymbionts belonging to the family Rickettsiaceae were recently identified in the unicellular green alga Carteria cerasiformis, providing the first molecular evidence of rickettsial endosymbionts within photosynthetic eukaryotes. However, previous morphological studies using transmission electron microscopy (TEM) with conventional chemical fixation did not demonstrate whether the endosymbionts of C. cerasiformis have the diagnostic characteristics of the family Rickettsiaceae. In this study, we observed the rickettsial endosymbionts "MIDORIKO" within C. cerasiformis cells by TEM with high-pressure freezing and freeze-substitution fixation. The rickettsial endosymbionts resided directly in the C. cerasiformis cytoplasm without engulfing or encompassing membranes or vacuoles. The endosymbionts had a Gram-negative cell envelope composed of outer and inner bilayer membranes. The thicknesses of the outer and inner leaflets of the bacterial cell wall were almost identical. These morphological characteristics are consistent with those of the genus Rickettsia, but the cell wall structure differed from that of the genus Orientia within the family Rickettsiaceae.}, }
@article {pmid23173201, year = {2013}, author = {Shigenobu, S and Stern, DL}, title = {Aphids evolved novel secreted proteins for symbiosis with bacterial endosymbiont.}, journal = {Proceedings. Biological sciences}, volume = {280}, number = {1750}, pages = {20121952}, pmid = {23173201}, issn = {1471-2954}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/*microbiology ; Buchnera/genetics/*physiology ; DNA, Complementary/genetics ; Evolution, Molecular ; High-Throughput Nucleotide Sequencing ; In Situ Hybridization ; Insect Proteins/biosynthesis/*genetics ; Protein Sorting Signals ; RNA, Messenger/genetics ; Sequence Alignment ; Sequence Analysis, RNA ; *Symbiosis ; }, abstract = {Aphids evolved novel cells, called bacteriocytes, that differentiate specifically to harbour the obligatory mutualistic endosymbiotic bacteria Buchnera aphidicola. The genome of the host aphid Acyrthosiphon pisum contains many orphan genes that display no similarity with genes found in other sequenced organisms, prompting us to hypothesize that some of these orphan genes are related to lineage-specific traits, such as symbiosis. We conducted deep sequencing of bacteriocytes mRNA followed by whole mount in situ hybridizations of over-represented transcripts encoding aphid-specific orphan proteins. We identified a novel class of genes that encode small proteins with signal peptides, which are often cysteine-rich, that are over-represented in bacteriocytes. These genes are first expressed at a developmental time point coincident with the incorporation of symbionts strictly in the cells that contribute to the bacteriocyte and this bacteriocyte-specific expression is maintained throughout the aphid's life. The expression pattern suggests that recently evolved secretion proteins act within bacteriocytes, perhaps to mediate the symbiosis with beneficial bacterial partners, which is reminiscent of the evolution of novel cysteine-rich secreted proteins of leguminous plants that regulate nitrogen-fixing endosymbionts.}, }
@article {pmid23171418, year = {2013}, author = {Moretti, R and Calvitti, M}, title = {Male mating performance and cytoplasmic incompatibility in a wPip Wolbachia trans-infected line of Aedes albopictus (Stegomyia albopicta).}, journal = {Medical and veterinary entomology}, volume = {27}, number = {4}, pages = {377-386}, doi = {10.1111/j.1365-2915.2012.01061.x}, pmid = {23171418}, issn = {1365-2915}, mesh = {Aedes/*microbiology/*physiology ; Animals ; Female ; Male ; Mosquito Control ; Pest Control, Biological/methods ; Reproduction/physiology ; Sexual Behavior, Animal ; Wolbachia/*physiology ; }, abstract = {Wolbachia pipientis Hertig (Rickettsiales: Rickettsiaceae) is a maternally inherited endosymbiont of a large number of insects and other arthropods that induces various effects on host reproductive biology. Among these, cytoplasmic incompatibility (CI) is a form of sterility induced in eggs produced by mating between infected males and females uninfected or infected by an incompatible Wolbachia strain. This phenomenon has been proposed as a potential way to produce functionally sterile males to be used in genetic control programmes. In this paper, we report on experiments carried out to evaluate the mating performances of males of an Aedes albopictus (Stegomyia albopicta) (Diptera: Culicidae) line (ARwP), harbouring a new Wolbachia infection [the wPip strain from Culex pipiens Linnaeus (Diptera: Culicidae)], in comparison with naturally infected males (SR line). ARwP males did not differ from SR males with regard to insemination capacity. Mating competitiveness did not differ significantly between lines in either laboratory or greenhouse conditions. Moreover, crosses with SR females were characterized by a 100% CI regardless of ARwP male age. All of these findings suggest that ARwP males may represent a very efficient tool for control programmes against Ae. albopictus based on the release of functionally sterile males.}, }
@article {pmid23168246, year = {2013}, author = {Kumari, P and Bijo, AJ and Mantri, VA and Reddy, CR and Jha, B}, title = {Fatty acid profiling of tropical marine macroalgae: an analysis from chemotaxonomic and nutritional perspectives.}, journal = {Phytochemistry}, volume = {86}, number = {}, pages = {44-56}, doi = {10.1016/j.phytochem.2012.10.015}, pmid = {23168246}, issn = {1873-3700}, mesh = {Fatty Acids/*metabolism ; Fatty Acids, Unsaturated/metabolism ; Seaweed/*classification/*metabolism ; Symbiosis/*physiology ; }, abstract = {The lipid and fatty acid (FA) compositions for 100 marine macroalgae were determined and discussed from the context of chemotaxonomic and nutritional perspectives. In general, the lipid contents in macroalgae were low (2.3-20 mg/g fr. wt.) but with substantially high amounts of nutritionally important polyunsaturated fatty acids (PUFAs) such as LA, ALA, STA, AA, EPA and DHA, that ranged from 10% to 70% of TFAs. More than 90% of the species showed nutritionally beneficial n6/n3 ratio (0.1:1-3.6:1) (p≤0.001). A closer look at the FA data revealed characteristic chemotaxonomic features with C18 PUFAs (LA, ALA and STA) being higher in Chlorophyta, C20 PUFAs (AA and EPA) in Rhodophyta while Phaeophyta depicted evenly distribution of C18 and C20 PUFAs. The ability of macroalgae to produce long-chain PUFAs could be attributed to the coupling of chloroplastic FA desaturase enzyme system from a photosynthetic endosymbiont to the FA desaturase/elongase enzyme system of a non-photosynthetic eukaryotic protist host. Further, the principal component analysis segregated the three macroalgal groups with a marked distinction of different genera, families and orders, Hierarchical cluster analyses substantiated the phylogenetic relationships of all orders investigated except for those red algal taxa belonging to Gigartinales, Ceramiales, Halymeniales and Rhodymeniales for which increased sampling effort is required to infer a conclusion. Also, the groups deduced from FA compositions were congruent with the clades inferred from nuclear and plastid genome sequences. This study further indicates that FA signatures could be employed as a valid chemotaxonomic tool to differentiate macroalgae at higher taxonomic levels such as family and orders.}, }
@article {pmid23166822, year = {2012}, author = {Saha, S and Hunter, WB and Reese, J and Morgan, JK and Marutani-Hert, M and Huang, H and Lindeberg, M}, title = {Survey of endosymbionts in the Diaphorina citri metagenome and assembly of a Wolbachia wDi draft genome.}, journal = {PloS one}, volume = {7}, number = {11}, pages = {e50067}, pmid = {23166822}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; Demography ; Genome, Bacterial/*genetics ; Hemiptera/genetics/*microbiology ; Metagenome/*genetics ; Molecular Sequence Annotation ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; Wolbachia/*genetics ; }, abstract = {Diaphorina citri (Hemiptera: Psyllidae), the Asian citrus psyllid, is the insect vector of Ca. Liberibacter asiaticus, the causal agent of citrus greening disease. Sequencing of the D. citri metagenome has been initiated to gain better understanding of the biology of this organism and the potential roles of its bacterial endosymbionts. To corroborate candidate endosymbionts previously identified by rDNA amplification, raw reads from the D. citri metagenome sequence were mapped to reference genome sequences. Results of the read mapping provided the most support for Wolbachia and an enteric bacterium most similar to Salmonella. Wolbachia-derived reads were extracted using the complete genome sequences for four Wolbachia strains. Reads were assembled into a draft genome sequence, and the annotation assessed for the presence of features potentially involved in host interaction. Genome alignment with the complete sequences reveals membership of Wolbachia wDi in supergroup B, further supported by phylogenetic analysis of FtsZ. FtsZ and Wsp phylogenies additionally indicate that the Wolbachia strain in the Florida D. citri isolate falls into a sub-clade of supergroup B, distinct from Wolbachia present in Chinese D. citri isolates, supporting the hypothesis that the D. citri introduced into Florida did not originate from China.}, }
@article {pmid23166641, year = {2012}, author = {Davis, TS and Horton, DR and Munyaneza, JE and Landolt, PJ}, title = {Experimental infection of plants with an herbivore-associated bacterial endosymbiont influences herbivore host selection behavior.}, journal = {PloS one}, volume = {7}, number = {11}, pages = {e49330}, pmid = {23166641}, issn = {1932-6203}, mesh = {Analysis of Variance ; Animals ; Hemiptera/*growth &amp; development/*microbiology ; Herbivory/*physiology ; Linear Models ; Oviposition/physiology ; Population Dynamics ; Reproduction/physiology ; *Rhizobiaceae ; Solanum tuberosum/chemistry/*parasitology ; *Symbiosis ; Volatile Organic Compounds/analysis ; }, abstract = {Although bacterial endosymbioses are common among phloeophagous herbivores, little is known regarding the effects of symbionts on herbivore host selection and population dynamics. We tested the hypothesis that plant selection and reproductive performance by a phloem-feeding herbivore (potato psyllid, Bactericera cockerelli) is mediated by infection of plants with a bacterial endosymbiont. We controlled for the effects of herbivory and endosymbiont infection by exposing potato plants (Solanum tuberosum) to psyllids infected with "Candidatus Liberibacter solanacearum" or to uninfected psyllids. We used these treatments as a basis to experimentally test plant volatile emissions, herbivore settling and oviposition preferences, and herbivore population growth. Three important findings emerged: (1) plant volatile profiles differed with respect to both herbivory and herbivory plus endosymbiont infection when compared to undamaged control plants; (2) herbivores initially settled on plants exposed to endosymbiont-infected psyllids but later defected and oviposited primarily on plants exposed only to uninfected psyllids; and (3) plant infection status had little effect on herbivore reproduction, though plant flowering was associated with a 39% reduction in herbivore density on average. Our experiments support the hypothesis that plant infection with endosymbionts alters plant volatile profiles, and infected plants initially recruited herbivores but later repelled them. Also, our findings suggest that the endosymbiont may not place negative selection pressure on its host herbivore in this system, but plant flowering phenology appears correlated with psyllid population performance.}, }
@article {pmid23166503, year = {2012}, author = {Clayton, AL and Oakeson, KF and Gutin, M and Pontes, A and Dunn, DM and von Niederhausern, AC and Weiss, RB and Fisher, M and Dale, C}, title = {A novel human-infection-derived bacterium provides insights into the evolutionary origins of mutualistic insect-bacterial symbioses.}, journal = {PLoS genetics}, volume = {8}, number = {11}, pages = {e1002990}, pmid = {23166503}, issn = {1553-7404}, support = {R01 AI095736/AI/NIAID NIH HHS/United States ; T32 GM007464/GM/NIGMS NIH HHS/United States ; 1R01AI095736/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Bacteria/genetics/pathogenicity ; *Biological Evolution ; Enterobacteriaceae/genetics ; Evolution, Molecular ; Host-Parasite Interactions/*genetics ; Humans ; Insecta/*genetics ; Molecular Sequence Data ; *Symbiosis ; Tsetse Flies/genetics/microbiology ; }, abstract = {Despite extensive study, little is known about the origins of the mutualistic bacterial endosymbionts that inhabit approximately 10% of the world's insects. In this study, we characterized a novel opportunistic human pathogen, designated "strain HS," and found that it is a close relative of the insect endosymbiont Sodalis glossinidius. Our results indicate that ancestral relatives of strain HS have served as progenitors for the independent descent of Sodalis-allied endosymbionts found in several insect hosts. Comparative analyses indicate that the gene inventories of the insect endosymbionts were independently derived from a common ancestral template through a combination of irreversible degenerative changes. Our results provide compelling support for the notion that mutualists evolve from pathogenic progenitors. They also elucidate the role of degenerative evolutionary processes in shaping the gene inventories of symbiotic bacteria at a very early stage in these mutualistic associations.}, }
@article {pmid23161855, year = {2012}, author = {Okubo, T and Fukushima, S and Minamisawa, K}, title = {Evolution of Bradyrhizobium-Aeschynomene mutualism: living testimony of the ancient world or highly evolved state?.}, journal = {Plant &amp; cell physiology}, volume = {53}, number = {12}, pages = {2000-2007}, doi = {10.1093/pcp/pcs150}, pmid = {23161855}, issn = {1471-9053}, mesh = {*Biological Evolution ; Bradyrhizobium/cytology/genetics/*physiology ; Endophytes ; Fabaceae/cytology/*genetics/microbiology ; Models, Biological ; Nitrogen Fixation ; Photosynthesis ; Phylogeny ; Plant Root Nodulation ; Root Nodules, Plant/cytology/genetics/microbiology ; Symbiosis/*genetics ; }, abstract = {Until recently it had been well established that the initial step in legume-rhizobia symbioses was flavonoid and Nod factor (NF) signaling. However, NF-independent symbiosis is now known to occur between Bradyrhizobium and some species of Aeschynomene. Since its discovery, this unusual symbiotic system has attracted attention, and efforts have been devoted to revealing the NF-independent symbiotic mechanism, although the molecular mechanisms of nodule initiation still remain to be elucidated. NF-independent symbiosis is also interesting from the perspective of the evolution of legume-rhizobia symbiosis. In this mini-review, we discuss the current literature on the NF-independent symbiotic system in terms of phylogeny of the partners, infection, bacteroid differentiation, nodule structure, photosynthesis, endophytic features and model host plant. We also discuss NF-independent symbiosis, which is generally regarded to be more primitive than NF-dependent symbiosis, because the bacteria invade host plants via 'crack entry'. We propose three possible scenarios concerning the evolution of NF-independent symbiosis, which do not exclude the possibility that the NF-independent system evolved from NF-dependent interactions. Finally, we examine an interesting question on Bradyrhizobium-Aeschynomene mutualism, which is how do they initiate symbiosis without NF. Phylogenetic and genomic analyses of symbiotic and non-symbiotic bradyrhizobia with A. indica may be crucial to address the question, because of the very narrow phylogeny of natural endosymbionts without nod genes compared with other legume-rhizobia symbioses.}, }
@article {pmid23152317, year = {2012}, author = {Morais, SA and Almeida, Fd and Suesdek, L and Marrelli, MT}, title = {Low genetic diversity in Wolbachia-Infected Culex quinquefasciatus (Diptera: Culicidae) from Brazil and Argentina.}, journal = {Revista do Instituto de Medicina Tropical de Sao Paulo}, volume = {54}, number = {6}, pages = {325-329}, doi = {10.1590/s0036-46652012000600007}, pmid = {23152317}, issn = {1678-9946}, mesh = {Animals ; Argentina ; Brazil ; Culex/*genetics/*microbiology ; Electron Transport Complex IV/*genetics ; Genes, Insect/genetics ; Genes, Mitochondrial/genetics ; Genetic Variation/*genetics ; NADH Dehydrogenase/*genetics ; *Wolbachia ; }, abstract = {Culex quinquefasciatus is a vector of human pathogens, including filarial nematodes and several viruses. Although its epidemiological relevance is known to vary across geographical regions, an understanding of its population genetic structure is still incipient. In light of this, we evaluated the genetic diversity of Cx. quinquefasciatus and Cx. pipiens x Cx. quinquefasciatus hybrids collected from nine localities in Brazil and one site in Argentina. We used mitochondrial genes cox1 and nd4, along with the coxA and wsp genes of the maternally-inherited Wolbachia endosymbiont. The nd4 fragment was invariant between samples, whilst cox1 exhibited four haplotypes that separated two types of Cx. quinquefasciatus, one clustered in southern Brazil. Low sequence diversity was generally observed, being discussed. Both Brazilian and Argentinian mosquitoes were infected with a single Wolbachia strain. As reported in previous studies with these populations, cox1 and nd4 diversity is not congruent with the population structure revealed by nuclear markers or alar morphology. Future Cx. quinquefasciatus research should, if possible, evaluate mtDNA diversity in light of other markers.}, }
@article {pmid23147105, year = {2013}, author = {Kopecky, J and Perotti, MA and Nesvorna, M and Erban, T and Hubert, J}, title = {Cardinium endosymbionts are widespread in synanthropic mite species (Acari: Astigmata).}, journal = {Journal of invertebrate pathology}, volume = {112}, number = {1}, pages = {20-23}, doi = {10.1016/j.jip.2012.11.001}, pmid = {23147105}, issn = {1096-0805}, mesh = {Animals ; Ascaris/*parasitology ; Bacteroidetes/*genetics ; Base Sequence ; DNA, Bacterial/genetics ; Mites/*parasitology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {'Candidatus Cardinium' is an intracellular endosymbiont or parasite frequently occurring in invertebrates including mites and ticks. In this work we report Cardinium bacteria in Astigmata mites and explore their incidence in synanthropic species. Amplification of a 776 bp bacterial 16S rRNA gene fragment, using specific primers, enabled identification of closely related Cardinium sequences in 13 laboratory-reared populations of mites. In addition, Cardinium sequences were identified in three wild mite populations. Large scale screening of these populations showed 100% prevalence of Cardinium, representing the highest incidence compared to other major Chelicerate groups.}, }
@article {pmid23144739, year = {2012}, author = {Xue, X and Li, SJ and Ahmed, MZ and De Barro, PJ and Ren, SX and Qiu, BL}, title = {Inactivation of Wolbachia reveals its biological roles in whitefly host.}, journal = {PloS one}, volume = {7}, number = {10}, pages = {e48148}, pmid = {23144739}, issn = {1932-6203}, mesh = {Animals ; Antibiotics, Antitubercular/pharmacology ; Body Size/drug effects ; Female ; Gene Expression/drug effects ; Genes, Bacterial/genetics ; Hemiptera/genetics/*microbiology/parasitology ; Host-Pathogen Interactions/drug effects ; In Situ Hybridization, Fluorescence ; Longevity/drug effects ; Male ; Nymph/genetics/microbiology/parasitology ; Parasite Egg Count ; RNA, Ribosomal, 16S/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rifampin/pharmacology ; Sex Ratio ; Symbiosis/drug effects/genetics/*physiology ; Wasps/physiology ; Wolbachia/drug effects/genetics/*physiology ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci is cryptic species complex composed of numerous species. Individual species from the complex harbor a diversity of bacterial endosymbionts including Wolbachia. However, while Wolbachia is known to have a number of different roles, its role in B. tabaci is unclear. Here, the antibiotic rifampicin is used to selectively eliminate Wolbachia from B. tabaci so as to enable its roles in whitefly development and reproduction to be explored. The indirect effects of Wolbachia elimination on the biology of Encarsia bimaculata, a dominant parasitoid of B. tabaci in South China, were also investigated.<br><br>METHODOLOGY/PRINCIPAL FINDING: qRT-PCR and FISH were used to show that after 48 h exposure to 1.0 mg/ml rifampicin, Wolbachia was completely inactivated from B. tabaci Mediterranean (MED) without any significant impact on either the primary symbiont, Portiera aleyrodidarum or any of the other secondary endosymbionts present. For B. tabaci MED, Wolbachia was shown to be associated with decreased juvenile development time, increased likelihood that nymphs completed development, increased adult life span and increased percentage of female progeny. Inactivation was associated with a significant decrease in the body size of the 4(th) instar which leads us to speculate as to whether Wolbachia may have a nutrient supplementation role. The reduction in nymph body size has consequences for its parasitoid, E. bimaculata. The elimination of Wolbachia lead to a marked increase in the proportion of parasitoid eggs that completed their development, but the reduced size of the whitefly host was also associated with a significant reduction in the size of the emerging parasitoid adult and this was in turn associated with a marked reduction in adult parasitoid longevity.<br><br>CONCLUSIONS/SIGNIFICANCE: Wolbachia increases the fitness of the whitefly host and provides some protection against parasitization. These observations add to our understanding of the roles played by bacterial endosymbionts.}, }
@article {pmid23144417, year = {2012}, author = {Jiang, ZF and Xia, F and Johnson, KW and Bartom, E and Tuteja, JH and Stevens, R and Grossman, RL and Brumin, M and White, KP and Ghanim, M}, title = {Genome sequences of the primary endosymbiont "Candidatus Portiera aleyrodidarum" in the whitefly Bemisia tabaci B and Q biotypes.}, journal = {Journal of bacteriology}, volume = {194}, number = {23}, pages = {6678-6679}, pmid = {23144417}, issn = {1098-5530}, support = {P50 GM081892/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/*chemistry/*genetics ; *Genome, Bacterial ; Halomonadaceae/*genetics/isolation &amp; purification/physiology ; Hemiptera/classification/microbiology/physiology ; Molecular Sequence Data ; *Sequence Analysis, DNA ; Symbiosis ; }, abstract = {"Candidatus Portiera aleyrodidarum" is the obligate primary endosymbiotic bacterium of whiteflies, including the sweet potato whitefly Bemisia tabaci, and provides essential nutrients to its host. Here we report two complete genome sequences of this bacterium from the B and Q biotypes of B. tabaci.}, }
@article {pmid23144402, year = {2012}, author = {Santos-Garcia, D and Farnier, PA and Beitia, F and Zchori-Fein, E and Vavre, F and Mouton, L and Moya, A and Latorre, A and Silva, FJ}, title = {Complete genome sequence of "Candidatus Portiera aleyrodidarum" BT-QVLC, an obligate symbiont that supplies amino acids and carotenoids to Bemisia tabaci.}, journal = {Journal of bacteriology}, volume = {194}, number = {23}, pages = {6654-6655}, pmid = {23144402}, issn = {1098-5530}, mesh = {Amino Acids/metabolism ; Animals ; Carotenoids/metabolism ; DNA, Bacterial/*chemistry/*genetics ; *Genome, Bacterial ; Halomonadaceae/*genetics/isolation &amp; purification/metabolism/physiology ; Hemiptera/microbiology/physiology ; Molecular Sequence Data ; *Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The genome of "Candidatus Portiera aleyrodidarum," the primary endosymbiont of the whitefly Bemisia tabaci (Mediterranean species), is reported. It presents a reduced genome (357 kb) encoding the capability to synthetize, or participate in the synthesis of, several amino acids and carotenoids, being the first insect endosymbiont capable of supplying carotenoids.}, }
@article {pmid23141103, year = {2013}, author = {Gehringer, H and Schacht, E and Maylaender, N and Zeman, E and Kaysser, P and Oehme, R and Pluta, S and Splettstoesser, WD}, title = {Presence of an emerging subclone of Francisella tularensis holarctica in Ixodes ricinus ticks from south-western Germany.}, journal = {Ticks and tick-borne diseases}, volume = {4}, number = {1-2}, pages = {93-100}, doi = {10.1016/j.ttbdis.2012.09.001}, pmid = {23141103}, issn = {1877-9603}, mesh = {Animals ; Animals, Wild ; Cluster Analysis ; Dermacentor/microbiology ; Francisella tularensis/*classification/*genetics ; Genetic Variation ; Germany/epidemiology ; Humans ; Ixodes/*microbiology ; Phylogeny ; Tularemia/epidemiology/microbiology/*veterinary ; }, abstract = {The zoonotic disease tularaemia is caused by the bacterial pathogen Francisella tularensis. Although the causative agent is known for 100 years, knowledge of its enzootic cycles is still rudimentary. Apart from tabanids and mosquitoes, hard ticks have been described as important vectors and potential reservoirs for F. tularensis. Available data on the incidence of human tularaemia indicate an increase in cases in the federal state of Baden-Wuerttemberg. To determine whether ticks are involved in the reported increase in F. tularensis infections in humans and wildlife in this south-western part of Germany, 916 Ixodes ricinus and 211 adult Dermacentor marginatus and D. reticulatus ticks were collected in two different locations. Screening for the presence of F. tularensis was performed by real-time PCR of the 16S rRNA gene. Of the 95 pools of I. ricinus ticks (representing 916 individual ticks), 8 tick pools (8.4%) were positive in this PCR. 30-bp deletion PCR confirmed that the F. tularensis subspecies holarctica was present. FtM24 VNTR analysis revealed that they belong to the emerging Franco-Iberian subclone group of F. tularensis holarctica. Of the 211 ticks of the genus Dermacentor, 35 randomly chosen DNAs were subjected to 16S rRNA gene screening PCR; 20 of these (57%) gave positive signals. For cluster analysis, the lpnA gene region of all Francisella-positive I. ricinus pools and 6 Dermacentor ticks with a positive reaction in the screening PCR was amplified and sequenced. In the resulting neighbour-joining tree, all Francisella-positive I. ricinus samples clustered with sequences of F. tularensis, whilst all Dermacentor tick samples clustered with FLE (Francisella-like endosymbiont) sequences. This study shows that I. ricinus ticks may serve as vectors and/or reservoirs of F. tularensis in Germany and supports the hypothesis that the state of Baden-Wuerttemberg represents an emerging endemic focus of tularaemia.}, }
@article {pmid23137173, year = {2013}, author = {Łukasik, P and van Asch, M and Guo, H and Ferrari, J and Godfray, HC}, title = {Unrelated facultative endosymbionts protect aphids against a fungal pathogen.}, journal = {Ecology letters}, volume = {16}, number = {2}, pages = {214-218}, doi = {10.1111/ele.12031}, pmid = {23137173}, issn = {1461-0248}, support = {BB/E010857/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/genetics/*microbiology ; Enterobacteriaceae ; Entomophthorales/*pathogenicity ; Spiroplasma ; *Symbiosis ; }, abstract = {The importance of microbial facultative endosymbionts to insects is increasingly being recognized, but our understanding of how the fitness effects of infection are distributed across symbiont taxa is limited. In the pea aphid, some of the seven known species of facultative symbionts influence their host's resistance to natural enemies, including parasitoid wasps and a pathogenic fungus. Here we show that protection against this entomopathogen, Pandora neoaphidis, can be conferred by strains of four distantly related symbionts (in the genera Regiella, Rickettsia, Rickettsiella and Spiroplasma). They reduce mortality and also decrease fungal sporulation on dead aphids which may help protect nearby genetically identical insects. Pea aphids thus obtain protection from natural enemies through association with a wider range of microbial associates than has previously been thought. Providing resistance against natural enemies appears to be a particularly common way for facultative endosymbionts to increase in frequency within host populations.}, }
@article {pmid23137057, year = {2013}, author = {Tan, DX and Manchester, LC and Liu, X and Rosales-Corral, SA and Acuna-Castroviejo, D and Reiter, RJ}, title = {Mitochondria and chloroplasts as the original sites of melatonin synthesis: a hypothesis related to melatonin's primary function and evolution in eukaryotes.}, journal = {Journal of pineal research}, volume = {54}, number = {2}, pages = {127-138}, doi = {10.1111/jpi.12026}, pmid = {23137057}, issn = {1600-079X}, mesh = {Animals ; Antioxidants/metabolism ; Chloroplasts/*metabolism ; Cyanobacteria/metabolism ; Free Radicals/metabolism ; Humans ; Melatonin/*metabolism ; Mitochondria/*metabolism ; }, abstract = {Mitochondria and chloroplasts are major sources of free radical generation in living organisms. Because of this, these organelles require strong protection from free radicals and associated oxidative stress. Melatonin is a potent free radical scavenger and antioxidant. It meets the criteria as a mitochondrial and chloroplast antioxidant. Evidence has emerged to show that both mitochondria and chloroplasts may have the capacity to synthesize and metabolize melatonin. The activity of arylalkylamine N-acetyltransferase (AANAT), the reported rate-limiting enzyme in melatonin synthesis, has been identified in mitochondria, and high levels of melatonin have also been found in this organelle. From an evolutionary point of view, the precursor of mitochondria probably is the purple nonsulfur bacterium, particularly, Rhodospirillum rubrum, and chloroplasts are probably the descendents of cyanobacteria. These bacterial species were endosymbionts of host proto-eukaryotes and gradually transformed into cellular organelles, that is, mitochondria and chloroplasts, respectively, thereby giving rise to eukaryotic cells. Of special importance, both purple nonsulfur bacteria (R. rubrum) and cyanobacteria synthesize melatonin. The enzyme activities required for melatonin synthesis have also been detected in these primitive species. It is our hypothesis that mitochondria and chloroplasts are the original sites of melatonin synthesis in the early stage of endosymbiotic organisms; this synthetic capacity was carried into host eukaryotes by the above-mentioned bacteria. Moreover, their melatonin biosynthetic capacities have been preserved during evolution. In most, if not in all cells, mitochondria and chloroplasts may continue to be the primary sites of melatonin generation. Melatonin production in other cellular compartments may have derived from mitochondria and chloroplasts. On the basis of this hypothesis, it is also possible to explain why plants typically have higher melatonin levels than do animals. In plants, both chloroplasts and mitochondria likely synthesize melatonin, while animal cells contain only mitochondria. The high levels of melatonin produced by mitochondria and chloroplasts are used to protect these important cellular organelles against oxidative stress and preserve their physiological functions. The superior beneficial effects of melatonin in both mitochondria and chloroplasts have been frequently reported.}, }
@article {pmid23116209, year = {2012}, author = {Strassert, JF and Köhler, T and Wienemann, TH and Ikeda-Ohtsubo, W and Faivre, N and Franckenberg, S and Plarre, R and Radek, R and Brune, A}, title = {'Candidatus Ancillula trichonymphae', a novel lineage of endosymbiotic Actinobacteria in termite gut flagellates of the genus Trichonympha.}, journal = {Environmental microbiology}, volume = {14}, number = {12}, pages = {3259-3270}, doi = {10.1111/1462-2920.12012}, pmid = {23116209}, issn = {1462-2920}, mesh = {Actinobacteria/*classification/genetics/isolation &amp; purification/ultrastructure ; Animals ; Cloning, Molecular ; Desulfovibrio/*classification/genetics/isolation &amp; purification/ultrastructure ; Gastrointestinal Tract/*microbiology ; Genes, rRNA ; Hypermastigia/*classification/isolation &amp; purification/physiology/ultrastructure ; Isoptera/*microbiology ; Phylogeny ; Species Specificity ; *Symbiosis/genetics ; }, abstract = {Termite gut flagellates are colonized by host-specific lineages of ectosymbiotic and endosymbiotic bacteria. Previous studies have shown that flagellates of the genus Trichonympha may harbour more than one type of symbiont. Using a comprehensive approach that combined cloning of SSU rRNA genes with fluorescence in situ hybridization and electron microscopy, we investigated the phylogeny and subcellular locations of the symbionts in a variety of Trichonympha species from different termites. The flagellates in Trichonympha Cluster I were the only species associated with 'Endomicrobia', which were located in the posterior part of the cell, confirming previous results. Trichonympha species of Cluster II from the termite genus Incisitermes (family Kalotermitidae) lacked 'Endomicrobia' and were associated with endosymbiotic Actinobacteria, which is highly unusual. The endosymbionts, for which we suggest the name 'Candidatus Ancillula trichonymphae', represent a novel, deep-branching lineage in the Micrococcineae that consists exclusively of clones from termite guts. They preferentially colonized the anterior part of the flagellate host and were highly abundant in all species of Trichonympha Cluster II except Trichonympha globulosa. Here, they were outnumbered by a Desulfovibrio species associated with the cytoplasmic lamellae at the anterior cell pole. Such symbionts are present in both Trichonympha clusters, but not in all species. Unlike the intracellular location reported for the Desulfovibrio symbionts of Trichonympha agilis (Cluster I), the Desulfovibrio symbionts of T. globulosa (Cluster II) were situated in deep invaginations of the plasma membrane that were clearly connected to the exterior of the host cell.}, }
@article {pmid23115298, year = {2013}, author = {Hussain, M and Lu, G and Torres, S and Edmonds, JH and Kay, BH and Khromykh, AA and Asgari, S}, title = {Effect of Wolbachia on replication of West Nile virus in a mosquito cell line and adult mosquitoes.}, journal = {Journal of virology}, volume = {87}, number = {2}, pages = {851-858}, pmid = {23115298}, issn = {1098-5514}, mesh = {Aedes/*virology ; Animals ; *Antibiosis ; Cell Line ; *Virus Replication ; West Nile virus/growth &amp; development/*physiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia as an endosymbiont is widespread in insects and other arthropods and is best known for reproductive manipulations of the host. Recently, it has been shown that wMelpop and wMel strains of Wolbachia inhibit the replication of several RNA viruses, including dengue virus, and other vector-borne pathogens (e.g., Plasmodium and filarial nematodes) in mosquitoes, providing an alternative approach to limit the transmission of vector-borne pathogens. In this study, we tested the effect of Wolbachia on the replication of West Nile Virus (WNV). Surprisingly, accumulation of the genomic RNA of WNV for all three strains of WNV tested (New York 99, Kunjin, and New South Wales) was enhanced in Wolbachia-infected Aedes aegypti cells (Aag2). However, the amount of secreted virus was significantly reduced in the presence of Wolbachia. Intrathoracic injections showed that replication of WNV in A. aegypti mosquitoes infected with wMel strain of Wolbachia was not inhibited, whereas wMelPop strain of Wolbachia significantly reduced the replication of WNV in mosquitoes. Further, when wMelPop mosquitoes were orally fed with WNV, virus infection, transmission, and dissemination rates were very low in Wolbachia-free mosquitoes and were completely inhibited in the presence of Wolbachia. The results suggest that (i) despite the enhancement of viral genomic RNA replication in the Wolbachia-infected cell line the production of secreted virus was significantly inhibited, (ii) the antiviral effect in intrathoracically infected mosquitoes depends on the strain of Wolbachia, and (iii) replication of the virus in orally fed mosquitoes was completely inhibited in wMelPop strain of Wolbachia.}, }
@article {pmid23113940, year = {2013}, author = {Khoo, CC and Venard, CM and Fu, Y and Mercer, DR and Dobson, SL}, title = {Infection, growth and maintenance of Wolbachia pipientis in clonal and non-clonal Aedes albopictus cell cultures.}, journal = {Bulletin of entomological research}, volume = {103}, number = {3}, pages = {251-260}, doi = {10.1017/S0007485312000648}, pmid = {23113940}, issn = {1475-2670}, support = {R01-AI051533/AI/NIAID NIH HHS/United States ; R01-AI067434/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*cytology/*microbiology ; Animals ; Bacterial Proteins/genetics ; Cell Culture Techniques/methods ; Cell Line ; DNA Primers/genetics ; Drosophila/*microbiology ; In Situ Hybridization, Fluorescence ; Indoles ; Polymerase Chain Reaction ; Wolbachia/*genetics/*growth &amp; development ; }, abstract = {Insect cell lines provide useful in vitro models for studying biological systems, including interactions between mosquitoes and obligate intracellular endosymbionts such as Wolbachia pipientis. The Aedes albopictus Aa23 cell line was the first cell line developed to allow examination of Wolbachia infections. However, Wolbachia studies using Aa23 can be complicated by the presence of different cell types in the cell line and the substantial temporal variation in infection level. Two approaches were examined to ameliorate infection variability. In the first approach, multiple Aa23 passaging regimes were tested for an effect on infection variability. Fluorescence in situ hybridization (FISH) staining was used to characterize Wolbachia infection level over time. The results demonstrate an impact of passaging method on Wolbachia infection level, with some methods resulting in loss of infection. None of the passaging methods succeeded in effectively mitigating infection level variation. In a second approach, the clonal C7-10 A. albopictus cell line was infected with Wolbachia from Aa23 cells and Drosophila simulans (Riverside), resulting in cell lines designated C7-10B and C7-10R, respectively. Characterization via FISH staining showed greater stability and uniformity of Wolbachia infection in C7-10R relative to the infection in C7-10B. Characterization of the Aa23, C7-10B and C7-10R lines is discussed as a tool for the study of Wolbachia-host cell interactions.}, }
@article {pmid23107230, year = {2013}, author = {Kuo, RC and Lin, S}, title = {Ectobiotic and endobiotic bacteria associated with Eutreptiella sp. isolated from Long Island Sound.}, journal = {Protist}, volume = {164}, number = {1}, pages = {60-74}, doi = {10.1016/j.protis.2012.08.004}, pmid = {23107230}, issn = {1618-0941}, mesh = {Alphaproteobacteria/*classification/genetics/isolation &amp; purification/physiology ; *Biodiversity ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Euglenida/growth &amp; development/*microbiology ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification/physiology ; Islands ; Microbial Interactions ; Microscopy ; Molecular Sequence Data ; New York ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Soil Microbiology ; Staining and Labeling ; }, abstract = {Diversity and functional association of bacteria with Eutreptiella sp. was investigated. 16S rDNA analysis of ectobiotic bacteria revealed various lineages of Alphaproteobacteria and abundant Gammaproteobacteria, specifically Marinobacter. Antibiotic treatment yielded axenic cultures, and experiments based on them indicated that ectobiotic bacteria likely provide vitamin B(12) and other growth-enhancing factors for the alga. Further, DAPI staining and transmission electron microscopy revealed endobiotic bacteria in the cytoplasm of algal cells. 16S rDNA analysis showed that the bacteria belonged to one species that was most closely related to Rickettsiales endosymbionts of other organisms and phylogenetically affiliated with a new group of aquatic Rickettsiales. Observations from a diel experiment indicated that the endobiotic bacteria reproduced asynchronously with Eutreptiella sp. and had no adverse effects on lipid production (bioenergetics) or growth of the host alga. Our study reveals a diverse microbiome associated with this euglenoid alga, offering a system for studying the roles of algae-bacteria associations.}, }
@article {pmid23106652, year = {2013}, author = {Jousselin, E and Cœur d'Acier, A and Vanlerberghe-Masutti, F and Duron, O}, title = {Evolution and diversity of Arsenophonus endosymbionts in aphids.}, journal = {Molecular ecology}, volume = {22}, number = {1}, pages = {260-270}, doi = {10.1111/mec.12092}, pmid = {23106652}, issn = {1365-294X}, mesh = {Animals ; Aphids/*microbiology ; *Biological Evolution ; DNA, Bacterial/genetics ; Enterobacteriaceae/*classification/genetics ; Gene Transfer, Horizontal ; Genes, Bacterial ; Molecular Sequence Data ; *Phylogeny ; Symbiosis/genetics ; }, abstract = {Endosymbiotic bacteria are important drivers of insect evolutionary ecology, acting both as partners that contribute to host adaptation and as subtle parasites that manipulate host reproduction. Among them, the genus Arsenophonus is emerging as one of the most widespread lineages. Its biology is, however, entirely unknown in most cases, and it is therefore unclear how infections spread through insect populations. Here we examine the incidence and evolutionary history of Arsenophonus in aphid populations from 86 species, characterizing the processes that shape their diversity. We identify aphids as harbouring an important diversity of Arsenophonus strains. Present in 7% of the sampled species, incidence was especially high in the Aphis genus with more than 31% of the infected species. Phylogenetic investigations revealed that these Arseno-phonus strains do not cluster within an aphid-specific clade but rather exhibit distinct evolutionary origins showing that they undergo repeated horizontal transfers (HT) between distantly related host species. Their diversity pattern strongly suggests that ecological interactions, such as plant mediation and parasitism, are major drivers for Arsenophonus dispersal, dictating global incidence across insect communities. Notably, plants hosting aphids may be important ecological arenas for global exchange of Arsenophonus, serving as reservoirs for HT.}, }
@article {pmid23100025, year = {2012}, author = {Okude, M and Matsuo, J and Nakamura, S and Kawaguchi, K and Hayashi, Y and Sakai, H and Yoshida, M and Takahashi, K and Yamaguchi, H}, title = {Environmental chlamydiae alter the growth speed and motility of host acanthamoebae.}, journal = {Microbes and environments}, volume = {27}, number = {4}, pages = {423-429}, pmid = {23100025}, issn = {1347-4405}, mesh = {Acanthamoeba/drug effects/growth &amp; development/*microbiology/*physiology ; *Cell Movement ; Chlamydiales/pathogenicity/*physiology ; Doxycycline/pharmacology ; *Phagocytosis ; *Pinocytosis ; Rifampin/pharmacology ; Symbiosis/drug effects ; }, abstract = {Symbiosis between living beings is an important driver of evolutionary novelty and ecological diversity; however, understanding the mechanisms underlying obligate mutualism remains a significant challenge. Regarding this, we have previously isolated two different Acanthamoeba strains harboring endosymbiotic bacteria, Protochlamydia (R18 symbiotic amoebae: R18WT) or Neochlamydia (S13 symbiotic amoebae; S13WT). In this study, we treated the symbiotic amoebae R18WT and S13WT with doxycycline (DOX) and rifampicin (RFP), respectively, to establish the aposymbiotic amoebae R18DOX and S13RFP, respectively. Subsequently, we compared the growth speed, motility, phagocytosis, pinocytosis, and morphology of the symbiotic and aposymbiotic amoebae. The growth speed of R18DOX was decreased, although that of S13RFP was increased. A marked change in motility was observed only for R18DOX amoebae. There was no difference in phagocytic and pinocytic activities between the symbiotic and aposymbiotic amoebae. Meanwhile, we observed a significant change in the phalloidin staining pattern and morphological changes in R18DOX (but not S13RFP) aposymbiotic amoebae, indicating a change in actin accumulation upon removal of the Protochlamydia. Infection of C3 (a reference strain) or S13RFP amoebae with Protochlamydia had a harmful effect on the host amoebae, but R18DOX amoebae re-infected with Protochlamydia showed recovery in both growth speed and motility. Taken together, we conclude that endosymbiont environmental chlamydiae alter the growth speed and/or motility of their host Acanthamoeba, possibly implying an close mutual relationship between amoebae and environmental chlamydiae.}, }
@article {pmid23091033, year = {2012}, author = {Beinart, RA and Sanders, JG and Faure, B and Sylva, SP and Lee, RW and Becker, EL and Gartman, A and Luther, GW and Seewald, JS and Fisher, CR and Girguis, PR}, title = {Evidence for the role of endosymbionts in regional-scale habitat partitioning by hydrothermal vent symbioses.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, number = {47}, pages = {E3241-50}, pmid = {23091033}, issn = {1091-6490}, mesh = {Animals ; Bayes Theorem ; Carbon Isotopes ; *Ecosystem ; Electrochemical Techniques ; Electron Transport Complex IV/genetics ; Epsilonproteobacteria/*genetics ; Gammaproteobacteria/*genetics ; Gastropoda/*genetics/*microbiology ; Geography ; Haplotypes/genetics ; Hydrothermal Vents/*microbiology ; Isotope Labeling ; Mitochondria/genetics ; Molecular Sequence Data ; Pacific Ocean ; Phylogeny ; Protein Subunits/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*genetics ; Temperature ; }, abstract = {Deep-sea hydrothermal vents are populated by dense communities of animals that form symbiotic associations with chemolithoautotrophic bacteria. To date, our understanding of which factors govern the distribution of host/symbiont associations (or holobionts) in nature is limited, although host physiology often is invoked. In general, the role that symbionts play in habitat utilization by vent holobionts has not been thoroughly addressed. Here we present evidence for symbiont-influenced, regional-scale niche partitioning among symbiotic gastropods (genus Alviniconcha) in the Lau Basin. We extensively surveyed Alviniconcha holobionts from four vent fields using quantitative molecular approaches, coupled to characterization of high-temperature and diffuse vent-fluid composition using gastight samplers and in situ electrochemical analyses, respectively. Phylogenetic analyses exposed cryptic host and symbiont diversity, revealing three distinct host types and three different symbiont phylotypes (one ε-proteobacteria and two γ-proteobacteria) that formed specific associations with one another. Strikingly, we observed that holobionts with ε-proteobacterial symbionts were dominant at the northern fields, whereas holobionts with γ-proteobacterial symbionts were dominant in the southern fields. This pattern of distribution corresponds to differences in the vent geochemistry that result from deep subsurface geological and geothermal processes. We posit that the symbionts, likely through differences in chemolithoautotrophic metabolism, influence niche utilization among these holobionts. The data presented here represent evidence linking symbiont type to habitat partitioning among the chemosynthetic symbioses at hydrothermal vents and illustrate the coupling between subsurface geothermal processes and niche availability.}, }
@article {pmid23087844, year = {2012}, author = {Yue, J and Huang, J}, title = {Algal genes in aplastidic eukaryotes are not necessarily derived from historical plastids.}, journal = {Mobile genetic elements}, volume = {2}, number = {4}, pages = {193-196}, pmid = {23087844}, issn = {2159-2543}, abstract = {In photosynthetic eukaryotes, many genes were transferred from plastids or algal endosymbionts to nuclear genomes of host cells. These transferred genes are often considered genetic footprints of plastids. However, genes of algal origin have also been detected in some plastid-lacking eukaryotes, and these genes are often cited as evidence of historical plastids. In this paper, we discuss two recent publications about algal genes in plastid-lacking eukaryotes. Both studies highlight the point that algal genes are not exclusively derived from historical plastids. Instead, the findings show that gene acquisition through feeding activities is a plausible explanation.}, }
@article {pmid23087165, year = {2013}, author = {Su, J and Zhou, Y and Lai, Q and Li, X and Dong, P and Yang, X and Zhang, B and Zhang, J and Zheng, X and Tian, Y and Zheng, T}, title = {Sinobacterium caligoides gen. nov., sp. nov., a new member of the family Oceanospirillaceae isolated from the South China Sea, and emended description of Amphritea japonica.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {63}, number = {Pt 6}, pages = {2095-2100}, doi = {10.1099/ijs.0.030965-0}, pmid = {23087165}, issn = {1466-5034}, mesh = {Bacterial Typing Techniques ; Base Composition ; China ; DNA, Bacterial/genetics ; Fatty Acids/analysis ; Molecular Sequence Data ; Oceanospirillaceae/*classification/genetics/isolation &amp; purification ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sequence Analysis, DNA ; Water Microbiology ; }, abstract = {A taxonomic study was carried out on strain SCSWE24(T), isolated from a seawater sample collected from the South China Sea. Cells of strain SCSWE24(T) were Gram-negative, rod-shaped, non-motile, moderately halophilic and capable of reducing nitrate to nitrite. Growth was observed at salinities from 1.5 to 4.5% and at 4-37 °C; it was unable to degrade gelatin. The dominant fatty acids (>15%) were summed feature 3 (C16:1ω7c and/or C16:1ω6c; 50.4%) and C16:0 (21.1%). The G+C content of the chromosomal DNA was 58.8 mol%. 16S rRNA gene sequence comparisons showed that strain SCSWE24(T) was most closely related to an uncultured bacterium clone Tun3b.F5 (98%; GenBank accession no. FJ169216), and showed 92% similarity to an endosymbiont bacterium from the bone-eating worm Osedax mucofloris (clone Omu 9 c4791; FN773233). Levels of similarity between strain SCSWE24(T) and type strains of recognized species in the family Oceanospirillaceae were less than 93%; the highest similarity was 92%, to both Amphritea japonica JAMM 1866(T) and 'Oceanicoccus sagamiensis' PZ-5. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SCSWE24(T) formed a distinct evolutionary lineage within the family Oceanospirillaceae. Strain SCSWE24(T) was distinguishable from members of phylogenetically related genera by differences in several phenotypic properties. On the basis of the phenotypic and phylogenetic data, strain SCSWE24(T) represents a novel species of a new genus, for which the name Sinobacterium caligoides gen. nov., sp. nov. is proposed. The type strain of Sinobacterium caligoides is SCSWE24(T) (=CCTCC AB 209289(T) =LMG 25705(T) =MCCC 1F01088(T)). An emended description of Amphritea japonica is also provided.}, }
@article {pmid23080406, year = {2013}, author = {Konishi, M and Watsuji, TO and Nakagawa, S and Hatada, Y and Takai, K and Toyofuku, T}, title = {Effects of hydrogen sulfide on bacterial communities on the surface of galatheid crab, Shinkaia crosnieri, and in a bacterial mat cultured in rearing tanks.}, journal = {Microbes and environments}, volume = {28}, number = {1}, pages = {25-32}, pmid = {23080406}, issn = {1347-4405}, mesh = {Animals ; Anomura/*microbiology ; Bacteroidetes/classification/*drug effects/genetics/growth &amp; development ; Biofilms/*drug effects/growth &amp; development ; Culture Media ; DNA, Bacterial/analysis/genetics ; Hydrogen Sulfide/*pharmacology ; Molecular Sequence Data ; Phylogeny ; Proteobacteria/classification/*drug effects/genetics/growth &amp; development ; RNA, Ribosomal, 16S/genetics ; Real-Time Polymerase Chain Reaction ; Seawater/microbiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {To investigate the effects of H2S on the bacterial consortia on the galatheid crab, Shinkaia crosnieri, crabs of this species were cultivated in the laboratory under two different conditions, with and without hydrogen sulfide feeding. We developed a novel rearing tank system equipped with a feedback controller using a semiconductor sensor for hydrogen sulfide feeding. H2S aqueous concentration was successfully maintained between 5 to 40 µM for 80 d with the exception of brief periods of mechanical issues. According to real-time PCR analysis, the numbers of copies of partial 16S rRNA gene of an episymbiont of the crabs with H2S feeding was three orders of magnitude larger than that without feeding. By phylogenetic analysis of partial 16S rRNA gene, we detected several clones related to symbionts of deep sea organisms in Alphaproteobacteria, Gammaproteobacteria, Epsilonproteobacteria, and Flavobacteria, from a crab with H2S feeding. The symbiont-related clones were grouped into four different groups: Gammaproteobacteria in marine epibiont group I, Sulfurovum-affiliated Epsilonproteobacteria, Osedax mucofloris endosymbiont-affiliated Epsilonproteobacteria, and Flavobacteria closely related to CFB group bacterial epibiont of Rimicaris exoculata. The other phylotypes were related to Roseobacter, and some Flavobacteria, seemed to be free-living psychrophiles. Furthermore, white biofilm occurred on the surface of the rearing tank with H2S feeding. The biofilms contained various phylotypes of Gammaproteobacteria, Epsilonproteobacteria, and Flavobacteria, as determined by phylogenetic analysis. Interestingly, major clones were related to symbionts of Alviniconcha sp. type 2 and to endosymbionts of Osedax mucofloris, in Epsilonproteobacteria.}, }
@article {pmid23077805, year = {2012}, author = {Sungpradit, S and Chatsuwan, T and Nuchprayoon, S}, title = {Susceptibility of Wolbachia, an endosymbiont of Brugia malayi microfilariae, to doxycycline determined by quantitative PCR assay.}, journal = {The Southeast Asian journal of tropical medicine and public health}, volume = {43}, number = {4}, pages = {841-850}, pmid = {23077805}, issn = {0125-1562}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Brugia malayi/*drug effects/genetics/microbiology ; Cell Migration Assays ; Ciprofloxacin/pharmacology ; Doxycycline/*pharmacology ; Drug Resistance, Bacterial/*genetics ; Microbial Sensitivity Tests ; Microfilariae/*drug effects/genetics ; Polymerase Chain Reaction ; Rifampin/pharmacology ; Time Factors ; Wolbachia/*drug effects/genetics ; }, abstract = {Lymphatic filariasis, caused by filarial nematodes, is a mosquito-borne disease that affects over 120 million people in the tropics and subtropics. The disease is caused mainly by Wuchereria bancrofti and Brugia malayi. Fertile adult female worms release offsprings (microfilariae) into the host blood circulatory system. Transmission-blocking agents as well as antimicrobial agents have been used to reduce microfilarial density in human and animal reservoir hosts. Doxycycline and rifampicin have an effect on the obligate intracellular gram-negative bacteria, Wolbachia, which appears to exert an influence on filarial nematode embryonic and larval development, adult female fertility, and filarial survival. We investigated the effects of doxycycline, rifampicin and ciprofloxacin on B. malayi microfilarial motility, expressed as minimum effective concentration (MEC), and on Wolbachia proliferation using quantitative PCR, expressed as the concentration of the drug to inhibit bacteria growth by 50% (IC50). MEC of doxycycline was 128 and 32 microg/ml at 12 and 52 hours, respectively, but rifampicin and ciprofloxacin were ineffective (MEC >256 microg/ml). IC50 of doxycycline was 32 and 2 microg/ml at 12 and 52 hours, but this for rifampicin (8 microg/ml) and ciprofloxacin (32 microg/ml) were obtained only after 52 hour treatment. Thus, MEC and IC50 assay methods used in this study could be applied to screen other agents targeting filariae and their endosymbiont bacteria.}, }
@article {pmid23077583, year = {2012}, author = {Manzano-Marín, A and Lamelas, A and Moya, A and Latorre, A}, title = {Comparative genomics of Serratia spp.: two paths towards endosymbiotic life.}, journal = {PloS one}, volume = {7}, number = {10}, pages = {e47274}, pmid = {23077583}, issn = {1932-6203}, mesh = {Animals ; Aphids/microbiology ; Buchnera/*genetics/growth &amp; development ; Evolution, Molecular ; *Genome, Bacterial ; Genomics ; Phylogeny ; Serratia/*genetics/growth &amp; development ; Symbiosis/*genetics ; }, abstract = {Symbiosis is a widespread phenomenon in nature, in which insects show a great number of these associations. Buchnera aphidicola, the obligate endosymbiont of aphids, coexists in some species with another intracellular bacterium, Serratia symbiotica. Of particular interest is the case of the cedar aphid Cinara cedri, where B. aphidicola BCc and S. symbiotica SCc need each other to fulfil their symbiotic role with the insect. Moreover, various features seem to indicate that S. symbiotica SCc is closer to an obligate endosymbiont than to other facultative S. symbiotica, such as the one described for the aphid Acirthosyphon pisum (S. symbiotica SAp). This work is based on the comparative genomics of five strains of Serratia, three free-living and two endosymbiotic ones (one facultative and one obligate) which should allow us to dissect the genome reduction taking place in the adaptive process to an intracellular life-style. Using a pan-genome approach, we have identified shared and strain-specific genes from both endosymbiotic strains and gained insight into the different genetic reduction both S. symbiotica have undergone. We have identified both retained and reduced functional categories in S. symbiotica compared to the Free-Living Serratia (FLS) that seem to be related with its endosymbiotic role in their specific host-symbiont systems. By means of a phylogenomic reconstruction we have solved the position of both endosymbionts with confidence, established the probable insect-pathogen origin of the symbiotic clade as well as the high amino-acid substitution rate in S. symbiotica SCc. Finally, we were able to quantify the minimal number of rearrangements suffered in the endosymbiotic lineages and reconstruct a minimal rearrangement phylogeny. All these findings provide important evidence for the existence of at least two distinctive S. symbiotica lineages that are characterized by different rearrangements, gene content, genome size and branch lengths.}, }
@article {pmid23069652, year = {2012}, author = {Veracx, A and Raoult, D}, title = {Biology and genetics of human head and body lice.}, journal = {Trends in parasitology}, volume = {28}, number = {12}, pages = {563-571}, doi = {10.1016/j.pt.2012.09.003}, pmid = {23069652}, issn = {1471-5007}, mesh = {Animals ; Arthropod Vectors/anatomy &amp; histology/classification/*genetics/*microbiology ; Bartonella quintana/physiology ; Biological Evolution ; Humans ; Lice Infestations/microbiology ; Pediculus/anatomy &amp; histology/classification/*genetics/microbiology ; Species Specificity ; }, abstract = {Head lice and body lice have distinct ecologies and differ slightly in morphology and biology, questioning their taxonomic status. Over the past 10 years many genetic studies have been undertaken. Controversial data suggest that not only body lice but also head lice can serve as vectors of Bartonella quintana, and a better understanding of louse epidemiology is crucial. Here, we review taxonomic studies based on biology and genetics, including genomic data on lice, lice endosymbionts, and louse-transmitted bacteria. We recommend that studies of human lice employ morphological and biological characteristics in conjunction with transcriptomic date because lice seem to differ mainly in gene expression (and not in gene content), leading to different phenotypes.}, }
@article {pmid23063745, year = {2013}, author = {Watanabe, M and Kageyama, D and Miura, K}, title = {Transfer of a parthenogenesis-inducing Wolbachia endosymbiont derived from Trichogramma dendrolimi into Trichogramma evanescens.}, journal = {Journal of invertebrate pathology}, volume = {112}, number = {1}, pages = {83-87}, doi = {10.1016/j.jip.2012.09.006}, pmid = {23063745}, issn = {1096-0805}, mesh = {Animals ; Host-Parasite Interactions/*physiology ; Parthenogenesis ; Polymerase Chain Reaction ; Wasps/*parasitology ; Wolbachia/*pathogenicity ; }, abstract = {Wolbachia, which are maternally transmitted endosymbionts, are considered to have moved horizontally between invertebrate hosts multiple times. However, it is not well understood how easily Wolbachia are transmitted horizontally between different hosts and how frequently horizontally-transmitted Wolbachia become established in their new hosts. We transferred a parthenogenesis-inducing Wolbachia endosymbiont derived from the parasitic wasp Trichogramma dendrolimi to Trichogramma evanescens. Specifically, Wolbachia was cultivated in a mosquito cell line and the Wolbachia-infected cells were microinjected into uninfected T. evanescens. Among 276 pupae inoculated with Wolbachia-infected cells, 65 adults emerged (G0). Diagnostic PCR demonstrated that 25 of 37 G0 females (68%) were Wolbachia-positive. Among isofemale lines established from G0 females, the proportions of infected lines were 80% (20 of 25) in G1 and 100% (18 of 18) in G2. In an isofemale line, infection was stably maintained for more than 10 generations. These results indicate invasion of Wolbachia into the germline of the recipient insect. Quantitative PCR demonstrated that the Wolbachia titer in the recipient host was significantly lower than that in the native host. The absence or very low number, if any, of parthenogenetically-reproducing individuals in the recipient host may be caused by the low Wolbachia titer. The Wolbachia titer in the recipients was lower in G11 than in G5, suggesting a decline in the density. Together with a previous report, our study may imply that Wolbachia in Trichogramma species are highly adapted to their hosts, which hinders robust expression of the Wolbachia phenotype in non-native host species.}, }
@article {pmid23061984, year = {2012}, author = {Graham, RI and Wilson, K}, title = {Male-killing Wolbachia and mitochondrial selective sweep in a migratory African insect.}, journal = {BMC evolutionary biology}, volume = {12}, number = {}, pages = {204}, pmid = {23061984}, issn = {1471-2148}, support = {BB/F004311/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animal Migration ; Animals ; Bacterial Proteins/genetics ; Cell Nucleus/genetics ; DNA, Mitochondrial/chemistry/*genetics ; DNA, Ribosomal/chemistry/classification/genetics ; Electron Transport Complex IV/genetics ; *Evolution, Molecular ; Female ; Geography ; Host-Pathogen Interactions ; Male ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 28S/genetics ; Seasons ; Selection, Genetic ; Sequence Analysis, DNA ; Sex Factors ; Spodoptera/*genetics/microbiology ; Symbiosis ; Tanzania ; Wolbachia/classification/*genetics/physiology ; }, abstract = {BACKGROUND: Numerous recent studies have shown that resident symbiotic microorganisms of insects play a fundamental role in host ecology and evolution. The lepidopteran pest, African armyworm (Spodoptera exempta), is a highly migratory and destructive species found throughout sub-Saharan Africa, that can experience eruptive outbreaks within the space of a single generation, making predicting population dynamics and pest control forecasting extremely difficult. Three strains of Wolbachia have recently been identified infecting this species in populations sampled from Tanzania. In this study, we examined the interaction between Wolbachia pipiensis infections and the co-inherited marker, mtDNA, within populations of armyworm, as a means to investigate the population biology and evolutionary history of Wolbachia and its host.<br><br>RESULTS: A Wolbachia-infected isofemale line was established in the laboratory. Phenotypic studies confirmed the strain wExe1 as a male-killer. Partial sequencing of the mitochondrial COI gene from 164 individual field-collected armyworm of known infection status revealed 17 different haplotypes. There was a strong association between Wolbachia infection status and mtDNA haplotype, with a single dominant haplotype, haplo1 (90.2% prevalence), harbouring the endosymbiont. All three Wolbachia strains were associated with this haplotype. This indicates that Wolbachia may be driving a selective sweep on armyworm haplotype diversity. Despite very strong biological and molecular evidence that the samples represent a single species (including from nuclear 28S gene markers), the 17 haplotypes did not fall into a monophyletic clade within the Spodoptera genus; with six haplotypes (2 each from 3 geographically separate populations) differing by >11% in their nucleotide sequence to the other eleven.<br><br>CONCLUSIONS: This study suggests that three strains of Wolbachia may be driving a selective sweep on armyworm haplotype diversity, and that based on COI sequence data, S. exempta is not a monophyletic group within the Spodoptera genus. This has clear implications for the use of mtDNA as neutral genetic markers in insects, and also demonstrates the impact of Wolbachia infections on host evolutionary genetics.}, }
@article {pmid23053393, year = {2012}, author = {Babu, S and Nutman, TB}, title = {Immunopathogenesis of lymphatic filarial disease.}, journal = {Seminars in immunopathology}, volume = {34}, number = {6}, pages = {847-861}, pmid = {23053393}, issn = {1863-2300}, support = {Z99 AI999999/ImNIH/Intramural NIH HHS/United States ; }, mesh = {Adaptive Immunity ; Animals ; Elephantiasis, Filarial/complications/diagnosis/*immunology ; Humans ; Immunity, Innate ; Lymphedema/etiology ; }, abstract = {Although two thirds of the 120 million people infected with lymph-dwelling filarial parasites have subclinical infections, ~40 million have lymphedema and/or other pathologic manifestations including hydroceles (and other forms of urogenital disease), episodic adenolymphangitis, tropical pulmonary eosinophilia, lymphedema, and (in its most severe form) elephantiasis. Adult filarial worms reside in the lymphatics and lymph nodes and induce changes that result in dilatation of lymphatics and thickening of the lymphatic vessel walls. Progressive lymphatic damage and pathology results from the summation of the effect of tissue alterations induced by both living and nonliving adult parasites, the host inflammatory response to the parasites and their secreted antigens, the host inflammatory response to the endosymbiont Wolbachia, and those seen as a consequence of secondary bacterial or fungal infections. Inflammatory damage induced by filarial parasites appears to be multifactorial, with endogenous parasite products, Wolbachia, and host immunity all playing important roles. This review will initially examine the prototypical immune responses engendered by the parasite and delineate the regulatory mechanisms elicited to prevent immune-mediated pathology. This will be followed by a discussion of the proposed mechanisms underlying pathogenesis, with the central theme being that pathogenesis is a two-step process-the first initiated by the parasite and host innate immune system and the second propagated mainly by the host's adaptive immune system and by other factors (including secondary infections).}, }
@article {pmid23049857, year = {2012}, author = {McNulty, SN and Abubucker, S and Simon, GM and Mitreva, M and McNulty, NP and Fischer, K and Curtis, KC and Brattig, NW and Weil, GJ and Fischer, PU}, title = {Transcriptomic and proteomic analyses of a Wolbachia-free filarial parasite provide evidence of trans-kingdom horizontal gene transfer.}, journal = {PloS one}, volume = {7}, number = {9}, pages = {e45777}, pmid = {23049857}, issn = {1932-6203}, support = {R01 AI081803/AI/NIAID NIH HHS/United States ; T32 AI007172/AI/NIAID NIH HHS/United States ; T32-AI007172/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi ; Conserved Sequence ; Gene Expression Regulation ; *Gene Transfer, Horizontal ; Genome ; Gerbillinae ; Immunohistochemistry/methods ; Mass Spectrometry/methods ; Onchocerca/*microbiology ; Parasites/genetics ; Protein Structure, Tertiary ; Proteomics/*methods ; Symbiosis/genetics ; *Transcription, Genetic ; Transcriptome ; Wolbachia/*genetics ; }, abstract = {Most filarial parasites in the subfamilies Onchocercinae and Dirofilariinae depend on Wolbachia endobacteria to successfully carry out their life cycle. Recently published data indicate that the few Wolbachia-free species in these subfamilies were infected in the distant past and have subsequently shed their endosymbionts. We used an integrated transcriptomic and proteomic analysis of Onchocerca flexuosa to explore the molecular mechanisms that allow worms of this species to survive without a bacterial partner. Roche/454 sequencing of the adult transcriptome produced 16,814 isogroup and 47,252 singleton sequences that are estimated to represent approximately 41% of the complete gene set. Sequences similar to 97 Wolbachia genes were identified from the transcriptome, some of which appear on the same transcripts as sequences similar to nematode genes. Computationally predicted peptides, including those with similarity to Wolbachia proteins, were classified at the domain and pathway levels in order to assess the metabolic capabilities of O. flexuosa and compare against the Wolbachia-dependent model filaria, Brugia malayi. Transcript data further facilitated a shotgun proteomic analysis of O. flexuosa adult worm lysate, resulting in the identification of 1,803 proteins. Three of the peptides detected by mass spectroscopy map to two ABC transport-related proteins from Wolbachia. Antibodies raised to one of the Wolbachia-like peptides labeled a single 38 kDa band on Western blots of O. flexuosa lysate and stained specific worm tissues by immunohistology. Future studies will be required to determine the exact functions of Wolbachia-like peptides and proteins in O. flexuosa and to assess their roles in worm biology.}, }
@article {pmid23044080, year = {2013}, author = {Schouten, S and Villareal, TA and Hopmans, EC and Mets, A and Swanson, KM and Sinninghe Damsté, JS}, title = {Endosymbiotic heterocystous cyanobacteria synthesize different heterocyst glycolipids than free-living heterocystous cyanobacteria.}, journal = {Phytochemistry}, volume = {85}, number = {}, pages = {115-121}, doi = {10.1016/j.phytochem.2012.09.002}, pmid = {23044080}, issn = {1873-3700}, mesh = {Cyanobacteria/*metabolism ; Glycolipids/chemistry/*metabolism ; Molecular Structure ; Symbiosis/*physiology ; }, abstract = {The heterocysts of limnetic nitrogen-fixing filamentous cyanobacteria contain unique glycolipids in their cell wall that create the distinctive gas impermeability of the heterocyst cell wall as well as serve as biomarker lipids for these microbes. It has been assumed that marine free-living and endosymbiotic cyanobacteria synthesize the same glycolipids although they have not been investigated in any detail. Here we report the glycolipid composition of several marine free-living heterocystous cyanobacteria as well as the heterocystous endosymbiont Richelia intracellularis found in the biogeochemically important diatoms Hemiaulus hauckii and Hemiaulus membranaceus. In the marine cyanobacteria Nostoc muscorum and Calothrix sp., we detected the same glycolipids as found in freshwater representatives of these genera. However, we did not detect these glycolipids in the Hemiaulus-Richelia association. Instead, we identified glycolipids which comprised a C5 sugar, ribose, rather than the C6 sugars normally encountered in glycolipids of free-living cyanobacteria. In addition, the glycolipids had slightly longer chain lengths (C30 and C32 versus C26 and C28) in the aglycone moiety. The different glycolipid composition of the marine endosymbotic heterocystous cyanobacteria compared to their free-living counterparts may be an adaptation to the high intracellular O2 concentrations within their host. These glycolipids may provide unique tracers for the presence of these microbes in marine environments and permit exploration of the evolutionary origins of these symbioses.}, }
@article {pmid23042170, year = {2012}, author = {Morse, SF and Dick, CW and Patterson, BD and Dittmar, K}, title = {Some like it hot: evolution and ecology of novel endosymbionts in bat flies of cave-roosting bats (hippoboscoidea, nycterophiliinae).}, journal = {Applied and environmental microbiology}, volume = {78}, number = {24}, pages = {8639-8649}, pmid = {23042170}, issn = {1098-5336}, mesh = {Animals ; Bacterial Physiological Phenomena ; Chiroptera/*parasitology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Diptera/*microbiology ; Gammaproteobacteria/*classification/genetics/*isolation &amp; purification ; Heat-Shock Proteins/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/classification/genetics/isolation &amp; purification ; }, abstract = {We investigated previously unknown associations between bacterial endosymbionts and bat flies of the subfamily Nycterophiliinae (Diptera, Streblidae). Molecular analyses revealed a novel clade of Gammaproteobacteria in Nycterophilia bat flies. This clade was not closely related to Arsenophonus-like microbes found in its sister genus Phalconomus and other bat flies. High population infection rates in Nycterophilia across a wide geographic area, the presence of the symbionts in pupae, the general codivergence between hosts and symbionts, and high AT composition bias in symbiont genes together suggest that this host-symbiont association is obligate in nature and ancient in origin. Some Nycterophilia samples (14.8%) also contained Wolbachia supergroup F (Alphaproteobacteria), suggesting a facultative symbiosis. Likelihood-based ancestral character mapping revealed that, initially, obligate symbionts exhibited association with host-specific Nycterophilia bat flies that use a broad temperature range of cave environments for pupal development. As this mutualism evolved, the temperature range of bat flies narrowed to an exclusive use of hot caves, which was followed by a secondary broadening of the bat flies' host associations. These results suggest that the symbiosis has influenced the environmental tolerance of parasite life history stages. Furthermore, the contingent change to an expanded host range of Nycterophilia bat flies upon narrowing the ecological niche of their developmental stages suggests that altered environmental tolerance across life history stages may be a crucial factor in shaping parasite-host relationships.}, }
@article {pmid23038770, year = {2012}, author = {Hirakawa, Y and Burki, F and Keeling, PJ}, title = {Dual targeting of aminoacyl-tRNA synthetases to the mitochondrion and complex plastid in chlorarachniophytes.}, journal = {Journal of cell science}, volume = {125}, number = {Pt 24}, pages = {6176-6184}, doi = {10.1242/jcs.116533}, pmid = {23038770}, issn = {1477-9137}, mesh = {Amino Acid Sequence ; Amino Acyl-tRNA Synthetases/genetics/*metabolism ; Cercozoa/*enzymology/*genetics/metabolism ; Green Fluorescent Proteins/metabolism ; Mitochondria/*enzymology/*genetics/metabolism ; Molecular Sequence Data ; Plastids/*enzymology/*genetics/metabolism ; *Protein Sorting Signals ; Protein Transport ; }, abstract = {In plants, many nucleus-encoded proteins are targeted to both mitochondria and plastids, and this process is generally mediated by ambiguous N-terminal targeting sequences that are recognized by receptors on both organelles. In many algae, however, plastids were acquired by secondarily engulfing green or red algae, which were retained within the endomembrane system. Protein targeting to these secondary plastids is more complex, and because they do not reside directly in the cytoplasm, dual targeting cannot function as it does in plant cells. Here we investigate dual targeting of aminoacyl-tRNA synthetases (aaRSs) in chlorarachniophytes, which are complex algae that possess secondary plastids and a relict nucleus derived from a green algal endosymbiont. Chlorarachniophytes have four genome-containing compartments, but almost all the aaRSs are nucleus-encoded and present in fewer than four copies (some as few as two), suggesting multiple targeting. We characterized the subcellular localization of two classes, HisRS (three copies) and GlyRS (two copies), using GFP fusion proteins. In both cases, one copy was dually targeted to mitochondria and plastids, but unlike plants this was mediated by translation initiation variants. We also found that the periplastidal compartment (the relict green algal cytoplasm) lacks both GlyRS and a cognate tRNA, suggesting that pre-charged host tRNAs are imported into this compartment. Leader analysis of other aaRSs suggests that alternative translation is a common strategy for dual targeting in these complex cells. Overall, dual targeting to mitochondria and plastids is a shared feature of plastid-bearing organisms, but the increased complexity of trafficking into secondary plastids requires a different strategy.}, }
@article {pmid23036316, year = {2013}, author = {Laurin-Lemay, S and Angers, B and Benrey, B and Brodeur, J}, title = {Inconsistent genetic structure among members of a multitrophic system: did bruchid parasitoids (Horismenus spp.) escape the effects of bean domestication?.}, journal = {Bulletin of entomological research}, volume = {103}, number = {2}, pages = {182-192}, doi = {10.1017/S000748531200051X}, pmid = {23036316}, issn = {1475-2670}, mesh = {Animals ; *Biological Evolution ; Coleoptera/*genetics/parasitology ; *Food Chain ; Genetic Variation ; Host-Parasite Interactions ; Mexico ; Phaseolus/*genetics ; Phylogeography ; Wasps/*genetics/microbiology ; Wolbachia/isolation &amp; purification ; }, abstract = {Anthropogenic range expansion and cultural practices have modified the distribution, abundance and genetic diversity of domesticated organisms, thereby altering multitrophic assemblages through space and time. The putative Mesoamerican domestication centre of the common bean, Phaseolus vulgaris L., in Mexico allows investigating the effects of plant domestication on the genetic structure of members of a multitrophic system. The aim of this study was to compare the evolutionary history of Horismenus parasitoids (Hymenoptera: Eulophidae) to those of their bruchid beetle hosts (Coleoptera: Bruchidae) and their domesticated host plant (P. vulgaris), in the context of traditional agriculture in Mexico. We analyzed the population genetic structure of four Horismenus species in Mexico using mitochondrial COI haplotype data. The two most abundant parasitoid species were Horismenus depressus and Horismenus missouriensis. Horismenus missouriensis were infected by Wolbachia endosymbionts and had little to no population differentiation (F(ST) = 0.06). We suspect the mitochondrial history of H. missouriensis to be blurred by Wolbachia, because differentiation among infected vs. non-infected individuals exists (F(ST) = 0.11). Populations of H. depressus were found to be highly differentiated (F(ST) = 0.34), but the genetic structuring could not be explained by tested spatial components. We then compared the genetic structure observed in this parasitoid species to previously published studies on bruchid beetles and their host plants. Despite extensive human-mediated migration and likely population homogenization of its two Acanthoscelides bruchid beetle hosts, H. depressus populations are structured like its host plant, by a recent dispersal from a diverse ancestral gene pool. Distinct evolutionary dynamics may explain inconsistent patterns among trophic levels. Parasitoids likely migrate from wild bean populations and are poorly adapted to bean storage conditions similar to their bruchid beetle hosts. Integrating several trophic levels to the study of evolutionary history has proven to be fruitful in detecting different ecological responses to human-mediated disturbances and host parasite interactions.}, }
@article {pmid23028923, year = {2012}, author = {Betcher, MA and Fung, JM and Han, AW and O'Connor, R and Seronay, R and Concepcion, GP and Distel, DL and Haygood, MG}, title = {Microbial distribution and abundance in the digestive system of five shipworm species (Bivalvia: Teredinidae).}, journal = {PloS one}, volume = {7}, number = {9}, pages = {e45309}, pmid = {23028923}, issn = {1932-6203}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; IU01TW008163-01/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/genetics ; Bivalvia/*microbiology ; Digestive System/*microbiology ; Gills/microbiology ; In Situ Hybridization ; Intestines/microbiology ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Marine bivalves of the family Teredinidae (shipworms) are voracious consumers of wood in marine environments. In several shipworm species, dense communities of intracellular bacterial endosymbionts have been observed within specialized cells (bacteriocytes) of the gills (ctenidia). These bacteria are proposed to contribute to digestion of wood by the host. While the microbes of shipworm gills have been studied extensively in several species, the abundance and distribution of microbes in the digestive system have not been adequately addressed. Here we use Fluorescence In-Situ Hybridization (FISH) and laser scanning confocal microscopy with 16S rRNA directed oligonucleotide probes targeting all domains, domains Bacteria and Archaea, and other taxonomic groups to examine the digestive microbiota of 17 specimens from 5 shipworm species (Bankia setacea, Lyrodus pedicellatus, Lyrodus massa, Lyrodus sp. and Teredo aff. triangularis). These data reveal that the caecum, a large sac-like appendage of the stomach that typically contains large quantities of wood particles and is considered the primary site of wood digestion, harbors only very sparse microbial populations. However, a significant number of bacterial cells were observed in fecal pellets within the intestines. These results suggest that due to low abundance, bacteria in the caecum may contribute little to lignocellulose degradation. In contrast, the comparatively high population density of bacteria in the intestine suggests a possible role for intestinal bacteria in the degradation of lignocellulose.}, }
@article {pmid23028321, year = {2012}, author = {Serbus, LR and Landmann, F and Bray, WM and White, PM and Ruybal, J and Lokey, RS and Debec, A and Sullivan, W}, title = {A cell-based screen reveals that the albendazole metabolite, albendazole sulfone, targets Wolbachia.}, journal = {PLoS pathogens}, volume = {8}, number = {9}, pages = {e1002922}, pmid = {23028321}, issn = {1553-7374}, support = {F32 GM080192/GM/NIGMS NIH HHS/United States ; R25 GM058903/GM/NIGMS NIH HHS/United States ; S10 RR022455/RR/NCRR NIH HHS/United States ; }, mesh = {Albendazole/*analogs &amp; derivatives/pharmacology ; Animals ; Brugia malayi/drug effects/*microbiology ; Cell Line ; Drosophila melanogaster/drug effects/*microbiology ; Filariasis/*drug therapy ; Microbial Sensitivity Tests ; Microtubules/drug effects ; Symbiosis ; Wolbachia/*drug effects ; }, abstract = {Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts.}, }
@article {pmid23025192, year = {2012}, author = {Beckmann, JF and Fallon, AM}, title = {Decapitation improves detection of Wolbachia pipientis (Rickettsiales: Anaplasmataceae) in Culex pipiens (Diptera: Culicidae) mosquitoes by the polymerase chain reaction.}, journal = {Journal of medical entomology}, volume = {49}, number = {5}, pages = {1103-1108}, pmid = {23025192}, issn = {0022-2585}, support = {R01 AI081322/AI/NIAID NIH HHS/United States ; AI081322/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cricetinae ; Culex/*microbiology ; Decapitation ; False Negative Reactions ; Polymerase Chain Reaction/standards ; Wolbachia/*isolation &amp; purification ; }, abstract = {Polymerase chain reaction (PCR) is often used to detect microorganisms, pathogens, or both, including the reproductive parasite Wolbachia pipientis (Rickettsiales: Anaplasmataceae), in mosquitoes. Natural populations of Culex pipiens L. (Diptera: Culicidae) mosquitoes are infected with one or more strains of W. pipientis, and crosses between mosquitoes harboring different Wolbachia strains provide one of the best-known examples of cytoplasmic incompatibililty (CI). When we used PCR to monitor Wolbachia in the Buckeye strain of Culex pipiens, and in a Wolbachia-cured sister colony obtained by tetracycline treatment, we noted false negative PCR reactions with DNA samples from infected mosquitoes; these results were inconsistent with direct microscopic observation of Wolbachia-like particles in gonads dissected from mosquitoes in the same population. Assays with diluted template often improved detection of positive samples, suggesting that DNA prepared from whole mosquitoes contained an inhibitor of the PCR reaction. We reconciled discrepancies between PCR and microscopy by systematic measurement of the PCR reaction in the presence of an internal standard. Mosquito decapitation before DNA extraction restored the reliability of the PCR reaction, allowing accurate determination of Wolbachia infection status in infected and tetracycline-cured mosquito populations, consistent with microscopic examination. Using PCR primers based on the Tr1 gene, we confirmed that the Wolbachia infection in the Buckeye strain of Culex pipiens belongs to the genotype designated wPip1. Finally, to explore more widely the distribution of PCR inhibitors, we demonstrated that DNA isolated from the cricket, Acheta domesticus (L.); the beetle, Tenebrio molitor L.; the honey bee, Apis mellifera L.; and the mosquito, Anopheles punctipennis Say also contained PCR inhibitors. These results underscore the importance of measuring the presence of inhibitors in PCR templates by using a known positive standard, and provide an approach that will facilitate use of PCR to monitor environmental samples of mosquitoes that harbor endosymbionts or pathogenic organisms.}, }
@article {pmid23024290, year = {2012}, author = {Yamaguchi, M and Mori, Y and Kozuka, Y and Okada, H and Uematsu, K and Tame, A and Furukawa, H and Maruyama, T and Worman, CO and Yokoyama, K}, title = {Prokaryote or eukaryote? A unique microorganism from the deep sea.}, journal = {Journal of electron microscopy}, volume = {61}, number = {6}, pages = {423-431}, doi = {10.1093/jmicro/dfs062}, pmid = {23024290}, issn = {1477-9986}, mesh = {*Aquatic Organisms ; *Biological Evolution ; *Eukaryotic Cells ; *Phylogeny ; *Prokaryotic Cells ; }, abstract = {There are only two kinds of organisms on the Earth: prokaryotes and eukaryotes. Although eukaryotes are considered to have evolved from prokaryotes, there were no previously known intermediate forms between them. The differences in their cellular structures are so vast that the problem of how eukaryotes could have evolved from prokaryotes is one of the greatest enigmas in biology. Here, we report a unique organism with cellular structures appearing to have intermediate features between prokaryotes and eukaryotes, which was discovered in the deep sea off the coast of Japan using electron microscopy and structome analysis. The organism was 10 µm long and 3 µm in diameter, having >100 times the volume of Escherichia coli. It had a large 'nucleoid', consisting of naked DNA fibers, with a single nucleoid membrane and endosymbionts that resemble bacteria, but no mitochondria. Because this organism appears to be a life form distinct from both prokaryotes and eukaryotes but similar to eukaryotes, we named this unique microorganism the 'Myojin parakaryote' with the scientific name of Parakaryon myojinensis ('next to (eu)karyote from Myojin') after the discovery location and its intermediate morphology. The existence of this organism is an indication of a potential evolutionary path between prokaryotes and eukaryotes.}, }
@article {pmid23017151, year = {2012}, author = {Sudakaran, S and Salem, H and Kost, C and Kaltenpoth, M}, title = {Geographical and ecological stability of the symbiotic mid-gut microbiota in European firebugs, Pyrrhocoris apterus (Hemiptera, Pyrrhocoridae).}, journal = {Molecular ecology}, volume = {21}, number = {24}, pages = {6134-6151}, doi = {10.1111/mec.12027}, pmid = {23017151}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification/genetics ; DNA, Bacterial/genetics ; Diet ; Europe ; Gastrointestinal Tract/*microbiology ; Genetics, Population ; Hemiptera/*microbiology ; *Metagenome ; *Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Symbiotic bacteria often play an essential nutritional role for insects, thereby allowing them to exploit novel food sources and expand into otherwise inaccessible ecological niches. Although many insects are inhabited by complex microbial communities, most studies on insect mutualists so far have focused on single endosymbionts and their interactions with the host. Here, we provide a comprehensive characterization of the gut microbiota of the red firebug (Pyrrhocoris apterus, Hemiptera, Pyrrhocoridae), a model organism for physiological and endocrinological research. A combination of several culture-independent techniques (454 pyrosequencing, quantitative PCR and cloning/sequencing) revealed a diverse community of likely transient bacterial taxa in the mid-gut regions M1, M2 and M4. However, the completely anoxic M3 region harboured a distinct microbiota consisting of facultative and obligate anaerobes including Actinobacteria (Coriobacterium glomerans and Gordonibacter sp.), Firmicutes (Clostri-dium sp. and Lactococcus lactis) and Proteobacteria (Klebsiella sp. and a previously undescribed Rickettsiales bacterium). Characterization of the M3 microbiota in different life stages of P. apterus indicated that the symbiotic bacterial community is vertically transmitted and becomes well defined between the second and third nymphal instar, which coincides with the initiation of feeding. Comparing the mid-gut M3 microbial communities of P. apterus individuals from five different populations and after feeding on three different diets revealed that the community composition is qualitatively and quantitatively very stable, with the six predominant taxa being consistently abundant. Our findings suggest that the firebug mid-gut microbiota constitutes a functionally important and possibly coevolved symbiotic community.}, }
@article {pmid23015773, year = {2012}, author = {Egas, C and Pinheiro, M and Gomes, P and Barroso, C and Bettencourt, R}, title = {The transcriptome of Bathymodiolus azoricus gill reveals expression of genes from endosymbionts and free-living deep-sea bacteria.}, journal = {Marine drugs}, volume = {10}, number = {8}, pages = {1765-1783}, pmid = {23015773}, issn = {1660-3397}, mesh = {Amino Acid Sequence ; Animals ; Atlantic Ocean ; Bacteria/*isolation &amp; purification ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Gills/microbiology ; Metagenome ; Molecular Sequence Data ; Mytilidae/*genetics/microbiology ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; *Transcriptome ; }, abstract = {Deep-sea environments are largely unexplored habitats where a surprising number of species may be found in large communities, thriving regardless of the darkness, extreme cold, and high pressure. Their unique geochemical features result in reducing environments rich in methane and sulfides, sustaining complex chemosynthetic ecosystems that represent one of the most surprising findings in oceans in the last 40 years. The deep-sea Lucky Strike hydrothermal vent field, located in the Mid Atlantic Ridge, is home to large vent mussel communities where Bathymodiolus azoricus represents the dominant faunal biomass, owing its survival to symbiotic associations with methylotrophic or methanotrophic and thiotrophic bacteria. The recent transcriptome sequencing and analysis of gill tissues from B. azoricus revealed a number of genes of bacterial origin, hereby analyzed to provide a functional insight into the gill microbial community. The transcripts supported a metabolically active microbiome and a variety of mechanisms and pathways, evidencing also the sulfur and methane metabolisms. Taxonomic affiliation of transcripts and 16S rRNA community profiling revealed a microbial community dominated by thiotrophic and methanotrophic endosymbionts of B. azoricus and the presence of a Sulfurovum-like epsilonbacterium.}, }
@article {pmid23009874, year = {2013}, author = {Van Elst, D and van Wyk, B and Schultz, A and Prinsen, E}, title = {Production of toxic pavettamine and pavettamine conjugates in the gousiekte-causing Fadogia homblei plant and its relation to the bacterial endosymbiont.}, journal = {Phytochemistry}, volume = {85}, number = {}, pages = {92-98}, doi = {10.1016/j.phytochem.2012.08.025}, pmid = {23009874}, issn = {1873-3700}, mesh = {Animals ; Mass Spectrometry ; Molecular Structure ; *Plant Poisoning ; Polyamines/*adverse effects ; Rubiaceae/*chemistry/*microbiology ; Ruminants ; Symbiosis ; }, abstract = {Plant poisoning of livestock is responsible for considerable economic losses in southern Africa. Six plant species of the Rubiaceae family are known to cause gousiekte, a cardiac syndrome of ruminants induced by ingestion of the toxic compound pavettamine. Progress in understanding the etiology of this disease is largely hampered by the variable toxicity of the plants and the absence of a quantification method for pavettamine. The pavettamine concentration in leaf samples of Fadogia homblei, a known gousiekte causing plant, was analyzed by mass-spectrometry. In the most apical leaf pair, the highest concentration of pavettamine was detected. Distal leaves contained progressively less pavettamine. Besides a significant amount of free pavettamine, most pavettamine was found to occur in a conjugated form. To which molecules the pavettamine is conjugated remains unknown as is the function of conjugated pavettamine in the development of gousiekte. All know gousiekte-causing plants contain symbiotic bacteria in their leaves; it was hypothesized that these bacteria might be involved in the production of pavettamine. However, analysis of in vitro cultures of the F. homblei endosymbiont revealed no production of pavettamine. Pavettamine is therefore not produced by the bacteria alone. It is either the product of the interaction with the plant or solely produced by the host.}, }
@article {pmid23006795, year = {2012}, author = {Salathé, RM and Vrijenhoek, RC}, title = {Temporal variation and lack of host specificity among bacterial endosymbionts of Osedax bone worms (Polychaeta: Siboglinidae).}, journal = {BMC evolutionary biology}, volume = {12}, number = {}, pages = {189}, pmid = {23006795}, issn = {1471-2148}, mesh = {Animals ; Bayes Theorem ; Bone and Bones/parasitology ; Cattle ; Electron Transport Complex IV/genetics ; Gammaproteobacteria/classification/*genetics/physiology ; Gene Frequency ; *Genetic Variation ; Haplotypes ; Host Specificity/genetics ; Host-Parasite Interactions ; Molecular Sequence Data ; Phylogeny ; Polychaeta/*genetics/microbiology/physiology ; RNA, Ribosomal, 16S/genetics ; Ribotyping ; Seasons ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis/*genetics ; Time Factors ; Whales ; }, abstract = {BACKGROUND: Osedax worms use a proliferative root system to extract nutrients from the bones of sunken vertebrate carcasses. The roots contain bacterial endosymbionts that contribute to the nutrition of these mouthless and gutless worms. The worms acquire these essential endosymbionts locally from the environment in which their larvae settle. Here we report on the temporal dynamics of endosymbiont diversity hosted by nine Osedax species sampled during a three-year investigation of an experimental whale fall at 1820-m depth in the Monterey Bay, California. The host species were identified by their unique mitochondrial COI haplotypes. The endosymbionts were identified by ribotyping with PCR primers specifically designed to target Oceanospirillales.<br><br>RESULTS: Thirty-two endosymbiont ribotypes associated with these worms clustered into two distinct bacterial ribospecies that together comprise a monophyletic group, mostly restricted to deep waters (>1000 m). Statistical analyses confirmed significant changes in the relative abundances of host species and the two dominant endosymbiont ribospecies during the three-year sampling period. Bone type (whale vs. cow) also had a significant effect on host species, but not on the two dominant symbiont ribospecies. No statistically significant association existed between the host species and endosymbiont ribospecies.<br><br>CONCLUSIONS: Standard PCR and direct sequencing proved to be an efficient method for ribotyping the numerically dominant endosymbiont strains infecting a large sample of host individuals; however, this method did not adequately represent the frequency of mixed infections, which appears to be the rule rather than an exception for Osedax individuals. Through cloning and the use of experimental dilution series, we determined that minority ribotypes constituting less than 30% of a mixture would not likely be detected, leading to underestimates of the frequency of multiple infections in host individuals.}, }
@article {pmid22998667, year = {2012}, author = {Rouchet, R and Vorburger, C}, title = {Strong specificity in the interaction between parasitoids and symbiont-protected hosts.}, journal = {Journal of evolutionary biology}, volume = {25}, number = {11}, pages = {2369-2375}, doi = {10.1111/j.1420-9101.2012.02608.x}, pmid = {22998667}, issn = {1420-9101}, mesh = {Animals ; Aphids/immunology/*microbiology/parasitology ; Biological Evolution ; Disease Resistance ; Disease Susceptibility/immunology/microbiology/parasitology ; Female ; Gammaproteobacteria/*growth &amp; development ; *Genotype ; *Host-Parasite Interactions ; Linear Models ; Oviposition ; Parthenogenesis ; *Symbiosis ; Wasps/pathogenicity ; }, abstract = {Coevolution between hosts and parasites may promote the maintenance of genetic variation in both antagonists by negative frequency-dependence if the host-parasite interaction is genotype-specific. Here we tested for specificity in the interaction between parasitoids (Lysiphlebus fabarum) and aphid hosts (Aphis fabae) that are protected by a heritable defensive endosymbiont, the γ-proteobacterium Hamiltonella defensa. Previous studies reported a lack of genotype specificity between unprotected aphids and parasitoids, but suggested that symbiont-conferred resistance might exhibit a higher degree of specificity. Indeed, in addition to ample variation in host resistance as well as parasitoid infectivity, we found a strong aphid clone-by-parasitoid line interaction on the rates of successful parasitism. This genotype specificity appears to be mediated by H. defensa, highlighting the important role that endosymbionts can play in host-parasite coevolution.}, }
@article {pmid22994649, year = {2012}, author = {Rosenblueth, M and Sayavedra, L and Sámano-Sánchez, H and Roth, A and Martínez-Romero, E}, title = {Evolutionary relationships of flavobacterial and enterobacterial endosymbionts with their scale insect hosts (Hemiptera: Coccoidea).}, journal = {Journal of evolutionary biology}, volume = {25}, number = {11}, pages = {2357-2368}, doi = {10.1111/j.1420-9101.2012.02611.x}, pmid = {22994649}, issn = {1420-9101}, mesh = {Animals ; *Biological Evolution ; Cloning, Molecular ; DNA, Bacterial/genetics ; Enterobacteriaceae/classification/genetics/*growth &amp; development ; Female ; Flavobacterium/classification/genetics/*growth &amp; development ; Genes, Insect ; Genetic Speciation ; Hemiptera/genetics/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Flavobacteria and Enterobacteriaceae have been previously reported as scale insect endosymbionts. The purpose of this work was twofold: first, to screen different scale insect families for the presence of these endosymbionts by PCR analyses and second, to elucidate the history of cophylogeny between these bacteria and the insects by analysing a portion of 16S rRNA and 18S rRNA gene sequences by two reconciliation tools, CoRe-PA and Jane. From a survey of 27 scale insects within seven families, we identified Flavobacteria and Enterobacteriaceae as coexisting in ten species that belong to the Ortheziidae, Monophlebidae, Diaspididae and Coccidae families, and we frequently found two closely related enterobacteria harboured in the same individual. Analyses performed with CoRe-PA and Jane suggest that Flavobacteria from the scale insects analysed have a unique origin, except for Candidatus Brownia rhizoecola (Flavobacteria of Pseudococcidae, Phenacoccinae), which seems to come from a nonscale insect. Nevertheless, cospeciation between Flavobacteria and scale insects is suggested only within the families Monophlebidae, Ortheziidae and Diaspididae, and host switches seem to have occurred from the ancestors of Monophlebidae and Ortheziidae to insects from families Coccidae, Lecanodiaspididae, Eriococcidae and Pseudococcidae. Our analyses suggest that Enterobacteriaceae underwent more evolutionary events (losses, duplications and host switches), and their phylogenies showed a lower proportion of congruent nodes between host and bacteria, indicating a more relaxed relationship with scale insects compared with Flavobacteria.}, }
@article {pmid22985862, year = {2013}, author = {Vilcinskas, A}, title = {Evolutionary plasticity of insect immunity.}, journal = {Journal of insect physiology}, volume = {59}, number = {2}, pages = {123-129}, doi = {10.1016/j.jinsphys.2012.08.018}, pmid = {22985862}, issn = {1879-1611}, mesh = {Animals ; Antimicrobial Cationic Peptides/genetics/metabolism ; *Evolution, Molecular ; *Immunity, Innate ; Insect Proteins/genetics/metabolism ; Insecta/*genetics/*immunology ; Protease Inhibitors/metabolism ; }, abstract = {Many insect genomes have been sequenced and the innate immune responses of several species have been studied by transcriptomics, inviting the comparative analysis of immunity-related genes. Such studies have demonstrated significant evolutionary plasticity, with the emergence of novel proteins and protein domains correlated with insects adapting to both abiotic and biotic environmental stresses. This review article focuses on effector molecules such as antimicrobial peptides (AMPs) and proteinase inhibitors, which display greater evolutionary dynamism than conserved components such as immunity-related signaling molecules. There is increasing evidence to support an extended role for insect AMPs beyond defense against pathogens, including the management of beneficial endosymbionts. The total number of AMPs varies among insects with completed genome sequences, providing intriguing examples of immunity gene expansion and loss. This plasticity is discussed in the context of recent developments in evolutionary ecology suggesting that the maintenance and deployment of immune responses reallocates resources from other fitness-related traits thus requiring fitness trade-offs. Based on our recent studies using both model and non-model insects, I propose that insect immunity genes can be lost when alternative defense strategies with a lower fitness penalty have evolved, such as the so-called social immunity in bees, the chemical sanitation of the microenvironment by some beetles, and the release of antimicrobial secondary metabolites in the hemolymph. Conversely, recent studies provide evidence for the expansion and functional diversification of insect AMPs and proteinase inhibitors to reflect coevolution with a changing pathosphere and/or adaptations to habitats or food associated with microbial contamination.}, }
@article {pmid22984624, year = {2012}, author = {Liu, S and Chougule, NP and Vijayendran, D and Bonning, BC}, title = {Deep sequencing of the transcriptomes of soybean aphid and associated endosymbionts.}, journal = {PloS one}, volume = {7}, number = {9}, pages = {e45161}, pmid = {22984624}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/microbiology/physiology ; Base Sequence ; Buchnera/genetics/physiology ; Digestive System/metabolism/microbiology ; Enterobacteriaceae/genetics/physiology ; Genes, Bacterial/genetics ; Genes, Insect/genetics ; High-Throughput Nucleotide Sequencing/*methods ; Host-Pathogen Interactions ; Insect Proteins/classification/genetics ; Molecular Sequence Data ; Peas/parasitology ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; Soybeans/parasitology ; *Transcriptome ; Wolbachia/genetics/physiology ; }, abstract = {BACKGROUND: The soybean aphid has significantly impacted soybean production in the U.S. Transcriptomic analyses were conducted for further insight into leads for potential novel management strategies.<br><br>Transcriptomic data were generated from whole aphids and from 2,000 aphid guts using an Illumina GAII sequencer. The sequence data were assembled de novo using the Velvet assembler. In addition to providing a general overview, we demonstrate (i) the use of the Multiple-k/Multiple-C method for de novo assembly of short read sequences, followed by BLAST annotation of contigs for increased transcript identification: From 400,000 contigs analyzed, 16,257 non-redundant BLAST hits were identified; (ii) analysis of species distributions of top non-redundant hits: 80% of BLAST hits (minimum e-value of 1.0-E3) were to the pea aphid or other aphid species, representing about half of the pea aphid genes; (iii) comparison of relative depth of sequence coverage to relative transcript abundance for genes with high (membrane alanyl aminopeptidase N) or low transcript abundance; (iv) analysis of the Buchnera transcriptome: Transcripts from 57.6% of the genes from Buchnera aphidicola were identified; (v) identification of Arsenophonus and Wolbachia as potential secondary endosymbionts; (vi) alignment of full length sequences from RNA-seq data for the putative salivary gland protein C002, the silencing of which has potential for aphid management, and the putative Bacillus thuringiensis Cry toxin receptors, aminopeptidase N and alkaline phosphatase.<br><br>CONCLUSIONS/SIGNIFICANCE: THIS STUDY PROVIDES THE MOST COMPREHENSIVE DATA SET TO DATE FOR SOYBEAN APHID GENE EXPRESSION: This work also illustrates the utility of short-read transcriptome sequencing and the Multiple-k/Multiple-C method followed by BLAST annotation for rapid identification of target genes for organisms for which reference genome sequences are not available, and extends the utility to include the transcriptomes of endosymbionts.}, }
@article {pmid22983037, year = {2012}, author = {Wernegreen, JJ}, title = {Strategies of genomic integration within insect-bacterial mutualisms.}, journal = {The Biological bulletin}, volume = {223}, number = {1}, pages = {112-122}, pmid = {22983037}, issn = {1939-8697}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {*Adaptation, Biological ; Animals ; Bacteria/*genetics ; *Bacterial Physiological Phenomena ; *Evolution, Molecular ; Genome Size ; Genome, Bacterial ; Genome, Insect ; Insecta/*genetics/*microbiology/physiology ; *Symbiosis ; }, abstract = {Insects, the most diverse group of macroorganisms with 900,000 known species, have been a rich playground for the evolution of symbiotic associations. Symbionts of this enormous animal group include a range of microbial partners. Insects are prone to establishing relationships with intracellular bacteria, which include the most intimate, highly integrated mutualisms known in the biological world. In recent years, an explosion of genomic studies has offered new insights into the molecular, functional, and evolutionary consequences of these insect-bacterial partnerships. In this review, I highlight some insights from genome sequences of bacterial endosymbionts and select insect hosts. Notably, comparisons between facultative and obligate bacterial mutualists have revealed distinct genome features representing different stages along a shared trajectory of genome reduction. Bacteria associated with the cedar aphid offer a snapshot of a transition from facultative to obligate mutualism, illustrating the genomic basis of this key step along the symbiotic spectrum. In addition, genomes of stable, dual bacterial symbionts reflect independent instances of astonishing metabolic integration. In these systems, synthesis of key nutrients, and perhaps basic cellular processes, require collaboration among co-residing bacteria and their insect host. These findings provide a launching point for a new era of genomic explorations of bacterial-animal symbioses. Future studies promise to reveal symbiotic strategies across a broad ecological and phylogenetic range, to clarify key transitions along a spectrum of interaction types, and to fuel new experimental approaches to dissect the mechanistic basis of intimate host-symbiont associations.}, }
@article {pmid22977066, year = {2012}, author = {Sloan, DB and Moran, NA}, title = {Endosymbiotic bacteria as a source of carotenoids in whiteflies.}, journal = {Biology letters}, volume = {8}, number = {6}, pages = {986-989}, pmid = {22977066}, issn = {1744-957X}, support = {F32 GM099334/GM/NIGMS NIH HHS/United States ; 1F32GM099334/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Arizona ; Base Sequence ; Carotenoids/*biosynthesis ; Chromosome Mapping ; Genome, Bacterial/*genetics ; Halomonadaceae/*genetics/*metabolism ; Hemiptera/metabolism/*microbiology ; Models, Genetic ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Although carotenoids serve important biological functions, animals are generally unable to synthesize these pigments and instead obtain them from food. However, many animals, such as sap-feeding insects, may have limited access to carotenoids in their diet, and it was recently shown that aphids have acquired the ability to produce carotenoids by lateral transfer of fungal genes. Whiteflies also contain carotenoids but show no evidence of the fungus-derived genes found in aphids. Because many sap-feeding insects harbour intracellular bacteria, it has long been hypothesized that these endosymbionts could serve as an alternative source of carotenoid biosynthesis. We sequenced the genome of the obligate bacterial endosymbiont Portiera from the whitefly Bemisia tabaci. The genome exhibits typical signatures of obligate endosymbionts in sap-feeding insects, including extensive size reduction (358.2 kb) and enrichment for genes involved in essential amino acid biosynthesis. Unlike other sequenced insect endosymbionts, however, Portiera has bacterial homologues of the fungal carotenoid biosynthesis genes in aphids. Therefore, related lineages of sap-feeding insects appear to have convergently acquired the same functional trait by distinct evolutionary mechanisms-bacterial endosymbiosis versus fungal lateral gene transfer.}, }
@article {pmid22973543, year = {2012}, author = {Aw, WC and Dowell, FE and Ballard, JW}, title = {Using near-infrared spectroscopy to resolve the species, gender, age, and the presence of Wolbachia infection in laboratory-reared Drosophila.}, journal = {G3 (Bethesda, Md.)}, volume = {2}, number = {9}, pages = {1057-1065}, pmid = {22973543}, issn = {2160-1836}, mesh = {Animals ; Drosophila/*classification/*microbiology ; Female ; Male ; *Sex Characteristics ; *Spectroscopy, Near-Infrared ; *Wolbachia ; }, abstract = {The aim of the study was to determine the accuracy of near-infrared spectroscopy (NIRS) in determining species, gender, age, and the presence of the common endosymbiont Wolbachia in laboratory-reared Drosophila. NIRS measures the absorption of light by organic molecules. Initially, a calibration model was developed for each study. An independent set with flies not involved in initial cross-validation was then used to validate the accuracy of each calibration model. Flies from the independent sets were correctly classified into Drosophila melanogaster and Drosophila simulans with 94% and 82% accuracy, respectively, whereas flies were successfully classified by gender with accuracy greater than 90%. In the age grading test, correlation plots of the actual and predicted age for males and females of D. melanogaster and D. simulans were shown to be overlapping between the adjacent age groups. It is, however, possible to predict the age of flies as less than 9 days of age with 62-88% accuracy and flies that are equal to or older than 9 days of age with 91-98% accuracy. Finally, we used NIRS to detect the presence of Wolbachia in flies. Flies from the independent sets were successfully identified as infected or not infected with Wolbachia with approximately 90% accuracy. These results suggest that NIRS has the potential to quantify the species, gender, and presence of Wolbachia in fly populations. However, additional optimization of the protocol may be necessary before the technique can reliably estimate fly age.}, }
@article {pmid22961037, year = {2012}, author = {Martínez, H and Toledo, J and Liedo, P and Mateos, M}, title = {Survey of heritable endosymbionts in southern Mexico populations of the fruit fly species Anastrepha striata and A. ludens.}, journal = {Current microbiology}, volume = {65}, number = {6}, pages = {711-718}, pmid = {22961037}, issn = {1432-0991}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Mexico ; Multilocus Sequence Typing ; Phylogeny ; Symbiosis/*genetics ; Tephritidae/classification/genetics/*microbiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Heritable endosymbiotic bacteria associated with insects are ubiquitous and taxonomically diverse. Many of these endosymbionts influence the fitness of their hosts and/or manipulate their host reproduction. Exploiting the effects of endosymbionts on hosts for pest control is a growing research area, but requires knowledge of endosymbionts associated with the target pest population. In this study, we used molecular methods to screen southern Mexico populations of two species of tephritid fruit fly pests, Anastrepha ludens and A. striata, for heritable bacteria. The only heritable endosymbiont found was Wolbachia in A. striata. Based on multilocus sequence typing and phylogenetic analyses, this Wolbachia strain is new and belongs to the Wolbachia supergroup B. Wolbachia strains previously reported in members of the genus Anastrepha in South America belong to supergroup A. We discuss the potential implications for pest control of the presence of a different Wolbachia strain in southern Mexico.}, }
@article {pmid22958655, year = {2012}, author = {Stentiford, GD and Bateman, KS and Small, HJ and Pond, M and Ungfors, A}, title = {Hematodinium sp. and its bacteria-like endosymbiont in European brown shrimp (Crangon crangon).}, journal = {Aquatic biosystems}, volume = {8}, number = {1}, pages = {24}, pmid = {22958655}, issn = {2046-9063}, abstract = {BACKGROUND: Parasitic dinoflagellates of the genus Hematodinium are significant pathogens affecting the global decapod crustacean fishery. Despite this, considerable knowledge gaps exist regarding the life history of the pathogen in vivo, and the role of free living life stages in transmission to naïve hosts.<br><br>RESULTS: In this study, we describe a novel disease in European brown shrimp (Crangon crangon) caused by infection with a parasitic dinoflagellate of the genus Hematodinium. This is the second example host within the Infraorder Caridea (shrimp) and significantly, the first description within the superfamily Crangonoidea. Based upon analysis of the rRNA gene (SSU) and spacers (ITS1), the parasite in C. crangon is the same as that previously described infecting Nephrops norvegicus and Cancer pagurus from European seas, and to the parasite infecting several other commercially important crab species in the Northern Hemisphere. The parasite is however distinct from the type species, H. perezi, found infecting type hosts (Carcinus maenas and Liocarcinus depurator) from nearby sites within Europe. Despite these similarities, the current study has also described for the first time, a bacteria-like endosymbiont within dinospore stages of the parasite infecting shrimp. The endosymbionts were either contained individually within electron lucent vacuoles within the parasite cell cytoplasm, or remained in direct contact with the parasite cytoplasm or in some cases, the nucleoplasm. In all of these cases, no apparent detrimental effects of colonization were observed within the parasite cell.<br><br>CONCLUSIONS: The presence of bacteria-like endosymbionts within dinospore life stages presumes that the relationship between the dinoflagellate and the bacteria is extended beyond the period of liberation of spores from the infected host shrimp. In this context, a potential role of endosymbiosis in the survival of free-living stages of the parasite is possible. The finding offers a further intriguing insight into the life history of this enigmatic pathogen of marine crustacean hosts and highlights a potential for mixotrophy in the parasitic dinoflagellates contained within the genus Hematodinium.}, }
@article {pmid22952398, year = {2012}, author = {Gray, MW}, title = {Mitochondrial evolution.}, journal = {Cold Spring Harbor perspectives in biology}, volume = {4}, number = {9}, pages = {a011403}, pmid = {22952398}, issn = {1943-0264}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {*Biological Evolution ; Evolution, Molecular ; *Genome, Mitochondrial ; Mitochondria/*genetics ; Models, Biological ; Phylogeny ; Proteome ; Symbiosis ; }, abstract = {Viewed through the lens of the genome it contains, the mitochondrion is of unquestioned bacterial ancestry, originating from within the bacterial phylum α-Proteobacteria (Alphaproteobacteria). Accordingly, the endosymbiont hypothesis--the idea that the mitochondrion evolved from a bacterial progenitor via symbiosis within an essentially eukaryotic host cell--has assumed the status of a theory. Yet mitochondrial genome evolution has taken radically different pathways in diverse eukaryotic lineages, and the organelle itself is increasingly viewed as a genetic and functional mosaic, with the bulk of the mitochondrial proteome having an evolutionary origin outside Alphaproteobacteria. New data continue to reshape our views regarding mitochondrial evolution, particularly raising the question of whether the mitochondrion originated after the eukaryotic cell arose, as assumed in the classical endosymbiont hypothesis, or whether this organelle had its beginning at the same time as the cell containing it.}, }
@article {pmid22951738, year = {2012}, author = {Duron, O and Bernard, J and Atyame, CM and Dumas, E and Weill, M}, title = {Rapid evolution of Wolbachia incompatibility types.}, journal = {Proceedings. Biological sciences}, volume = {279}, number = {1746}, pages = {4473-4480}, pmid = {22951738}, issn = {1471-2954}, mesh = {Animals ; Bacterial Proteins/*genetics ; Culex/*microbiology/physiology ; Cytoplasm/microbiology ; *Evolution, Molecular ; Female ; Fertility ; Host-Pathogen Interactions ; Hybridization, Genetic ; Male ; Molecular Sequence Data ; Polymerase Chain Reaction ; Reproduction ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {In most insects, the endosymbiont Wolbachia induces cytoplasmic incompatibility (CI), an embryonic mortality observed when infected males mate either with uninfected females or with females infected by an incompatible Wolbachia strain. Although the molecular mechanism of CI remains elusive, it is classically viewed as a modification-rescue model, in which a Wolbachia mod function disables the reproductive success of the sperm of infected males, unless eggs are infected and express a compatible resc function. The extent to which the modification-rescue model can predict highly complex CI pattern remains a challenging issue. Here, we show the rapid evolution of the mod-resc system in the Culex pipiens mosquito. We have surveyed four incompatible laboratory isofemale lines over 50 generations and observed in two of them that CI has evolved from complete to partial incompatibility (i.e. the production of a mixture of compatible and incompatible clutches). Emergence of the new CI types depends only on Wolbachia determinants and can be simply explained by the gain of new resc functions. Evolution of CI types in Cx. pipiens thus appears as a gradual process, in which one or several resc functions can coexist in the same individual host in addition to the ones involved in the self-compatibility. Our data identified CI as a very dynamic process. We suggest that ancestral and mutant Wolbachia expressing distinct resc functions can co-infect individual hosts, opening the possibility for the mod functions to evolve subsequently. This gives a first clue towards the understanding of how Wolbachia reached highly complex CI pattern in host populations.}, }
@article {pmid22948828, year = {2012}, author = {Lenhart, K and Bunge, M and Ratering, S and Neu, TR and Schüttmann, I and Greule, M and Kammann, C and Schnell, S and Müller, C and Zorn, H and Keppler, F}, title = {Evidence for methane production by saprotrophic fungi.}, journal = {Nature communications}, volume = {3}, number = {}, pages = {1046}, pmid = {22948828}, issn = {2041-1723}, mesh = {Aerobiosis ; Basidiomycota/genetics/*metabolism ; Biomass ; Methane/*metabolism ; Methionine/metabolism ; }, abstract = {Methane in the biosphere is mainly produced by prokaryotic methanogenic archaea, biomass burning, coal and oil extraction, and to a lesser extent by eukaryotic plants. Here we demonstrate that saprotrophic fungi produce methane without the involvement of methanogenic archaea. Fluorescence in situ hybridization, confocal laser-scanning microscopy and quantitative real-time PCR confirm no contribution from microbial contamination or endosymbionts. Our results suggest a common methane formation pathway in fungal cells under aerobic conditions and thus identify fungi as another source of methane in the environment. Stable carbon isotope labelling experiments reveal methionine as a precursor of methane in fungi. These findings of an aerobic fungus-derived methane formation pathway open another avenue in methane research and will further assist with current efforts in the identification of the processes involved and their ecological implications.}, }
@article {pmid22947080, year = {2012}, author = {Zug, R and Koehncke, A and Hammerstein, P}, title = {Epidemiology in evolutionary time: the case of Wolbachia horizontal transmission between arthropod host species.}, journal = {Journal of evolutionary biology}, volume = {25}, number = {11}, pages = {2149-2160}, doi = {10.1111/j.1420-9101.2012.02601.x}, pmid = {22947080}, issn = {1420-9101}, mesh = {Algorithms ; Animals ; Arthropods/*microbiology/physiology ; *Biological Evolution ; Computer Simulation ; Models, Biological ; Phylogeny ; Species Specificity ; Stochastic Processes ; Time Factors ; Wolbachia/classification/*physiology ; }, abstract = {Wolbachia are bacterial endosymbionts that manipulate the reproduction of their arthropod hosts. Although theory suggests that infections are frequently lost within host species due to the evolution of resistance, Wolbachia infect a huge number of species worldwide. This apparent paradox suggests that horizontal transmission between host species has been a key factor in shaping the global Wolbachia pandemic. Because Wolbachia infections are thus acquired and lost like any other infection, we use a standard epidemiological model to analyse Wolbachia horizontal transmission dynamics over evolutionary time. Conceptually modifying the model, we apply it not to transmission between individuals but between species. Because, on evolutionary timescales, infections spread frequently between closely related species and occasionally over large phylogenetic distances, we represent the set of host species as a small-world network that satisfies both requirements. Our model reproduces the effect of basic epidemiological parameters, which demonstrates the validity of our approach. We find that the ratio between transmission rate and recovery rate is crucial for determining the proportion of infected species (incidence) and that, in a given host network, the incidence may still be increasing over evolutionary time. Our results also point to the importance of occasional transmission over long phylogenetic distances for the observed high incidence levels of Wolbachia. In conclusion, we are able to explain why Wolbachia are so abundant among arthropods, although selection for resistance within hosts often leads to infection loss. Furthermore, our unorthodox approach of using epidemiology in evolutionary time can be applied to all symbionts that use horizontal transmission to infect new hosts.}, }
@article {pmid22945464, year = {2012}, author = {Nachappa, P and Levy, J and Tamborindeguy, C}, title = {Transcriptome analyses of Bactericera cockerelli adults in response to "Candidatus Liberibacter solanacearum" infection.}, journal = {Molecular genetics and genomics : MGG}, volume = {287}, number = {10}, pages = {803-817}, pmid = {22945464}, issn = {1617-4623}, mesh = {Aging ; Animals ; Gene Expression Profiling ; *Helicobacter ; Hemiptera/*genetics/microbiology ; Insect Proteins/analysis/*genetics ; }, abstract = {The potato/tomato psyllid, Bactericera cockerelli (Šulc) is an economically important crop pest that not only causes damage through its feeding but also transmits the bacterium, "Candidatus Liberibacter solanacearum" (CLs), which causes zebra chip disease in potato. There is some information about the phenotypic effects of phytopathogenic bacteria on their insect vectors; however, there are no published reports of the molecular mechanisms underlying phytopathogenic bacteria-insect vector interaction. In order to investigate the effects of CLs infection on B. cockerelli, transcriptomic analyses of CLs-infected and uninfected adult psyllids that were reared on potato were performed. De novo assembly of cDNA sequences generated 136,518 and 109,983 contigs for infected and uninfected insect libraries with an average contig length of 514 bp. BlastX analysis against the NCBI-nr database revealed that 33.33 % had significant matches. Gene ontology data illustrated that the majority of the expressed psyllid genes are involved in metabolic process, biological regulation, binding and catalytic activity. The psyllid transcriptome had an abundance of genes such as vitellogenin, heat shock protein, ejaculatory bulb-specific protein, ferritin, and cytochrome oxidase. Notably absent in the psyllid transcriptome were innate immunity genes induced in response to Gram-negative bacteria (IMD pathway). Several functionally diverse contigs related to symbiotic bacteria including the primary endosymbiont Carsonella ruddii, Wolbachia, and CLs in the psyllid transcriptome were identified. A total of 247 contigs showed differential expression in response to CLs infection including immune and stress-related genes and vitellogenins. Expression analyses of selected psyllid genes were performed on psyllids that were exclusively reared on potato (host of the insects used for RNAseq) and psyllids exclusively reared on tomato (alternative host of psyllids). These genes showed similar expression patterns irrespective of the host plant on which the psyllids were reared, which suggests that host-plant association may not modulate expression of these genes. Our findings suggest that the impact of CLs on psyllid transcriptome was to a large extent on genes involved in metabolic processes and to a small extent on immune and stress response genes. This study is the first description of transcriptomic changes in an insect vector in response to infection with a naturally occurring bacterial plant pathogen. Data from this study provide new sequence and gene expression resources for functional genomics of potato psyllids.}, }
@article {pmid22942672, year = {2012}, author = {Xia, X}, title = {DNA replication and strand asymmetry in prokaryotic and mitochondrial genomes.}, journal = {Current genomics}, volume = {13}, number = {1}, pages = {16-27}, pmid = {22942672}, issn = {1875-5488}, abstract = {Different patterns of strand asymmetry have been documented in a variety of prokaryotic genomes as well as mitochondrial genomes. Because different replication mechanisms often lead to different patterns of strand asymmetry, much can be learned of replication mechanisms by examining strand asymmetry. Here I summarize the diverse patterns of strand asymmetry among different taxonomic groups to suggest that (1) the single-origin replication may not be universal among bacterial species as the endosymbionts Wigglesworthia glossinidia, Wolbachia species, cyanobacterium Synechocystis 6803 and Mycoplasma pulmonis genomes all exhibit strand asymmetry patterns consistent with the multiple origins of replication, (2) different replication origins in some archaeal genomes leave quite different patterns of strand asymmetry, suggesting that different replication origins in the same genome may be differentially used, (3) mitochondrial genomes from representative vertebrate species share one strand asymmetry pattern consistent with the strand-displacement replication documented in mammalian mtDNA, suggesting that the mtDNA replication mechanism in mammals may be shared among all vertebrate species, and (4) mitochondrial genomes from primitive forms of metazoans such as the sponge and hydra (representing Porifera and Cnidaria, respectively), as well as those from plants, have strand asymmetry patterns similar to single-origin or multi-origin replications observed in prokaryotes and are drastically different from mitochondrial genomes from other metazoans. This may explain why sponge and hydra mitochondrial genomes, as well as plant mitochondrial genomes, evolves much slower than those from other metazoans.}, }
@article {pmid22940732, year = {2013}, author = {Boscaro, V and Fokin, SI and Schrallhammer, M and Schweikert, M and Petroni, G}, title = {Revised systematics of Holospora-like bacteria and characterization of "Candidatus Gortzia infectiva", a novel macronuclear symbiont of Paramecium jenningsi.}, journal = {Microbial ecology}, volume = {65}, number = {1}, pages = {255-267}, pmid = {22940732}, issn = {1432-184X}, mesh = {DNA, Bacterial/genetics ; Holosporaceae/*classification/genetics ; In Situ Hybridization, Fluorescence ; Paramecium/*microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The genus Holospora (Rickettsiales) includes highly infectious nuclear symbionts of the ciliate Paramecium with unique morphology and life cycle. To date, nine species have been described, but a molecular characterization is lacking for most of them. In this study, we have characterized a novel Holospora-like bacterium (HLB) living in the macronuclei of a Paramecium jenningsi population. This bacterium was morphologically and ultrastructurally investigated in detail, and its life cycle and infection capabilities were described. We also obtained its 16S rRNA gene sequence and developed a specific probe for fluorescence in situ hybridization experiments. A new taxon, "Candidatus Gortzia infectiva", was established for this HLB according to its unique characteristics and the relatively low DNA sequence similarities shared with other bacteria. The phylogeny of the order Rickettsiales based on 16S rRNA gene sequences has been inferred, adding to the available data the sequence of the novel bacterium and those of two Holospora species (Holospora obtusa and Holospora undulata) characterized for the purpose. Our phylogenetic analysis provided molecular support for the monophyly of HLBs and showed a possible pattern of evolution for some of their features. We suggested to classify inside the family Holosporaceae only HLBs, excluding other more distantly related and phenotypically different Paramecium endosymbionts.}, }
@article {pmid22939414, year = {2012}, author = {Boscaro, V and Vannini, C and Fokin, SI and Verni, F and Petroni, G}, title = {Characterization of "Candidatus Nebulobacter yamunensis" from the cytoplasm of Euplotes aediculatus (Ciliophora, Spirotrichea) and emended description of the family Francisellaceae.}, journal = {Systematic and applied microbiology}, volume = {35}, number = {7}, pages = {432-440}, doi = {10.1016/j.syapm.2012.07.003}, pmid = {22939414}, issn = {1618-0984}, mesh = {Cluster Analysis ; Cytoplasm/microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Euplotes/*microbiology ; Francisella/*classification/genetics/*isolation &amp; purification/physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Our knowledge of ciliate endosymbionts occurrence and diversity greatly expanded in the last decades, due to the development of characterization methods for uncultivable bacteria. Symbionts related to human pathogens such as rickettsiae and francisellae have been detected inside the cytoplasm of different ciliate species. In the present work, we have characterized a novel Francisella-related bacterium inside the rich prokaryotic community harbored by a population of Euplotes aediculatus (Ciliophora, Spirotrichea). Following the "Full-Cycle rRNA Approach" we obtained the almost full-length 16S rRNA gene sequence of this bacterium, and developed probes for diagnostic fluorescence in situ hybridizations. Attempts to culture the endosymbiont outside of its host failed. We classified this novel organism in a new taxon for which we propose the name "Candidatus Nebulobacter yamunensis". In order to investigate its evolutionary relationships, we have also performed phylogenetic analyses on the class Gammaproteobacteria and the order Thiotrichales, which include the monogeneric family Francisellaceae. We found highly supported evidences for the establishment of a new monophyletic taxon including Francisella species, other organisms currently incertae sedis, and "Candidatus Nebulobacter yamunensis". These organisms form a clade sharing a signature sequence not present in other Thiotrichales bacteria. Moreover, most of them have developed an intracellular life cycle inside eukaryotic organisms. We emended the original description of family Francisellaceae in order to encompass all members of the described clade.}, }
@article {pmid22916303, year = {2012}, author = {Imanian, B and Pombert, JF and Dorrell, RG and Burki, F and Keeling, PJ}, title = {Tertiary endosymbiosis in two dinotoms has generated little change in the mitochondrial genomes of their dinoflagellate hosts and diatom endosymbionts.}, journal = {PloS one}, volume = {7}, number = {8}, pages = {e43763}, pmid = {22916303}, issn = {1932-6203}, mesh = {DNA, Mitochondrial/*genetics ; Diatoms/*physiology ; Dinoflagellida/*genetics ; Genome, Mitochondrial/*genetics ; Symbiosis/*genetics/physiology ; }, abstract = {BACKGROUND: Mitochondria or mitochondrion-derived organelles are found in all eukaryotes with the exception of secondary or tertiary plastid endosymbionts. In these highly reduced systems, the mitochondrion has been lost in all cases except the diatom endosymbionts found in a small group of dinoflagellates, called 'dinotoms', the only cells with two evolutionarily distinct mitochondria. To investigate the persistence of this redundancy and its consequences on the content and structure of the endosymbiont and host mitochondrial genomes, we report the sequences of these genomes from two dinotoms.<br><br>The endosymbiont mitochondrial genomes of Durinskia baltica and Kryptoperidinium foliaceum exhibit nearly identical gene content with other diatoms, and highly conserved gene order (nearly identical to that of the raphid pennate diatom Fragilariopsis cylindrus). These two genomes are differentiated from other diatoms' by the fission of nad11 and by an insertion within nad2, in-frame and unspliced from the mRNA. Durinskia baltica is further distinguished from K. foliaceum by two gene fusions and its lack of introns. The host mitochondrial genome in D. baltica encodes cox1 and cob plus several fragments of LSU rRNA gene in a hugely expanded genome that includes numerous pseudogenes, and a trans-spliced cox3 gene, like in other dinoflagellates. Over 100 distinct contigs were identified through 454 sequencing, but intact full-length genes for cox1, cob and the 5' exon of cox3 were present as a single contig each, suggesting most of the genome is pseudogenes. The host mitochondrial genome of K. foliaceum was difficult to identify, but fragments of all the three protein-coding genes, corresponding transcripts, and transcripts of several LSU rRNA fragments were all recovered.<br><br>CONCLUSIONS/SIGNIFICANCE: Overall, the endosymbiont and host mitochondrial genomes in the two dinotoms have changed surprisingly little from those of free-living diatoms and dinoflagellates, irrespective of their long coexistence side by side in dinotoms.}, }
@article {pmid22916258, year = {2012}, author = {Masloboeva, N and Reutimann, L and Stiefel, P and Follador, R and Leimer, N and Hennecke, H and Mesa, S and Fischer, HM}, title = {Reactive oxygen species-inducible ECF σ factors of Bradyrhizobium japonicum.}, journal = {PloS one}, volume = {7}, number = {8}, pages = {e43421}, pmid = {22916258}, issn = {1932-6203}, mesh = {Bacterial Proteins/*metabolism ; Bradyrhizobium/*metabolism ; Gene Expression Regulation, Bacterial ; Genome, Bacterial/genetics ; Protein Binding ; Reactive Oxygen Species/*metabolism ; Sigma Factor/*metabolism ; }, abstract = {Extracytoplasmic function (ECF) σ factors control the transcription of genes involved in different cellular functions, such as stress responses, metal homeostasis, virulence-related traits, and cell envelope structure. The genome of Bradyrhizobium japonicum, the nitrogen-fixing soybean endosymbiont, encodes 17 putative ECF σ factors belonging to nine different ECF σ factor families. The genes for two of them, ecfQ (bll1028) and ecfF (blr3038), are highly induced in response to the reactive oxygen species hydrogen peroxide (H(2)O(2)) and singlet oxygen ((1)O(2)). The ecfF gene is followed by the predicted anti-σ factor gene osrA (blr3039). Mutants lacking EcfQ, EcfF plus OsrA, OsrA alone, or both σ factors plus OsrA were phenotypically characterized. While the symbiotic properties of all mutants were indistinguishable from the wild type, they showed increased sensitivity to singlet oxygen under free-living conditions. Possible target genes of EcfQ and EcfF were determined by microarray analyses, and candidate genes were compared with the H(2)O(2)-responsive regulon. These experiments disclosed that the two σ factors control rather small and, for the most part, distinct sets of genes, with about half of the genes representing 13% of the members of H(2)O(2)-responsive regulon. To get more insight into transcriptional regulation of both σ factors, the 5' ends of ecfQ and ecfF mRNA were determined. The presence of conserved sequence motifs in the promoter region of ecfQ and genes encoding EcfQ-like σ factors in related α-proteobacteria suggests regulation via a yet unknown transcription factor. By contrast, we have evidence that ecfF is autoregulated by transcription from an EcfF-dependent consensus promoter, and its product is negatively regulated via protein-protein interaction with OsrA. Conserved cysteine residues 129 and 179 of OsrA are required for normal function of OsrA. Cysteine 179 is essential for release of EcfF from an EcfF-OsrA complex upon H(2)O(2) stress while cysteine 129 is possibly needed for EcfF-OsrA interaction.}, }
@article {pmid22912533, year = {2011}, author = {Xie, J and Tiner, B and Vilchez, I and Mateos, M}, title = {Effect of the Drosophila endosymbiont Spiroplasma on parasitoid wasp development and on the reproductive fitness of wasp-attacked fly survivors.}, journal = {Evolutionary ecology}, volume = {53}, number = {5}, pages = {1065-1079}, pmid = {22912533}, issn = {0269-7653}, support = {R03 AI078348/AI/NIAID NIH HHS/United States ; R03 AI078348-02/AI/NIAID NIH HHS/United States ; }, abstract = {In a previous study, we showed that Spiroplasma, a maternally transmitted endosymbiotic bacterium of Drosophila hydei, enhances larval to adult survival of its host when exposed to oviposition attack by the parasitoid wasp Leptopilina heterotoma. The mechanism by which Spiroplasma enhances host survival has not been elucidated. To better understand this mechanism, we compared the growth of wasp larvae in Spiroplasma-infected and uninfected hosts. Our results indicate that wasp embryos in Spiroplasma-infected hosts hatch and grow normally for ~2 days, after which their growth is severely impaired, compared to wasps developing in uninfected hosts. Thus, despite their reduced ability to complete development in Spiroplasma-infected hosts, developing wasps may exert fitness costs on their hosts that are manifested after host emergence. The severity of these costs will influence the degree to which this protective mechanism contributes to the long-term persistence of Spiroplasma in D. hydei. We therefore examined survival to 10-day-old adult stage and fecundity of Spiroplasma-infected flies surviving a wasp treatment. Our results suggest detrimental effects of wasp attack on longevity of Spiroplasma-infected adult flies. However, compared to Spiroplasma-free flies exposed to wasps, Spiroplasma-infected flies exposed to wasps have ~5 times greater survival from larva to 10 day-adult. The relative fecundity of wasp-attacked Spiroplasma-infected females was ~71% that of un-attacked Spiroplasma-free females. Our combined survival and female fecundity results suggest that under high wasp parasitism, the reproductive fitness of Spiroplasma-infected flies may be ~3.5 times greater than that of uninfected females, so it is potentially relevant to the persistence of Spiroplasma in natural populations of D. hydei. Interestingly, Spiroplasma-infected males surviving a wasp attack were effectively sterile during the 3-day period examined. This observation is consistent with the expectation that, as a maternally transmitted symbiont, there is little selective pressure on Spiroplasma to enhance the reproductive fitness of its male hosts.}, }
@article {pmid22910876, year = {2013}, author = {Pyke, KA}, title = {Divide and shape: an endosymbiont in action.}, journal = {Planta}, volume = {237}, number = {2}, pages = {381-387}, pmid = {22910876}, issn = {1432-2048}, mesh = {Arabidopsis/cytology/metabolism ; Biological Evolution ; Cell Differentiation ; *Cell Division ; Green Fluorescent Proteins/metabolism ; Intracellular Membranes/metabolism ; Meristem/cytology/metabolism ; Mesophyll Cells/metabolism ; *Organelle Shape ; Plant Cells/metabolism ; Plant Proteins/genetics/metabolism ; Plastids/genetics/*metabolism ; *Symbiosis ; }, abstract = {The endosymbiotic evolution of the plastid within the host cell required development of a mechanism for efficient division of the plastid. Whilst a model for the mechanism of chloroplast division has been constructed, little is known of how other types of plastids divide, especially the proplastid, the progenitor of all plastid types in the cell. It has become clear that plastid shape is highly heterogeneous and dynamic, especially stromules. This article considers how such variation in morphology might be controlled and how such plastids might divide efficiently.}, }
@article {pmid22907174, year = {2013}, author = {Sarasa, J and Bernal, A and Fernández-Calvín, B and Bella, JL}, title = {Wolbachia induced cytogenetical effects as evidenced in Chorthippus parallelus (Orthoptera).}, journal = {Cytogenetic and genome research}, volume = {139}, number = {1}, pages = {36-43}, doi = {10.1159/000341572}, pmid = {22907174}, issn = {1424-859X}, mesh = {Animals ; Cell Shape ; Chromosome Banding ; Chromosomes, Insect/genetics ; Fertility/genetics ; Genes, Bacterial ; Genetic Markers ; Grasshoppers/cytology/*genetics/microbiology ; Host-Pathogen Interactions ; Male ; Meiosis ; RNA, Ribosomal, 16S/genetics ; Spermatids/microbiology ; Symbiosis/genetics ; Wolbachia/genetics/*physiology ; X Chromosome/genetics ; }, abstract = {The cytoplasmic incompatibility induced by the bacterial endosymbiont Wolbachia is attributed to chromatin modification in the sperm of infected individuals and is only 'rescued' by infected females after fertilization. Chorthippus parallelus is a grasshopper with 2 subspecies that form a hybrid zone in the Pyrenees in which this Wolbachia-generated cytoplasmic incompatibility has recently been described. The analysis of certain cytogenetic traits (sex chromosome-linked heterochromatic bands, nucleolar organizing region expression, spermatid size and morphology, and number of chiasmata formed) in pure and hybrid Chorthippus parallelus that are infected and not infected by this bacterium indicates that the infection affects some of these traits and, in the case of the spermatids, reveals a synergism between the infection and the hybrid condition. These results are interpreted as being secondary effects of the chromatin modification induced by Wolbachia which thereby support this model of modification/rescue. The possible effects of these cytogenetic variations on affected individuals are also considered.}, }
@article {pmid22902511, year = {2013}, author = {Huynen, MA and Duarte, I and Szklarczyk, R}, title = {Loss, replacement and gain of proteins at the origin of the mitochondria.}, journal = {Biochimica et biophysica acta}, volume = {1827}, number = {2}, pages = {224-231}, doi = {10.1016/j.bbabio.2012.08.001}, pmid = {22902511}, issn = {0006-3002}, mesh = {Mitochondria/*metabolism ; Oxidative Phosphorylation ; Proteins/*metabolism ; }, abstract = {We review what has been inferred about the changes at the level of the proteome that accompanied the evolution of the mitochondrion from an alphaproteobacterium. We regard these changes from an alphaproteobacterial perspective: which proteins were lost during mitochondrial evolution? And, of the proteins that were lost, which ones have been replaced by other, non-orthologous proteins with a similar function? Combining literature-supported replacements with quantitative analyses of mitochondrial proteomics data we infer that most of the loss and replacements that separate current day mitochondria in mammals from alphaproteobacteria took place before the radiation of the eukaryotes. Recent analyses show that also the acquisition of new proteins to the large protein complexes of the oxidative phosphorylation and the mitochondrial ribosome occurred mainly before the divergence of the eukaryotes. These results indicate a significant number of pivotal evolutionary events between the acquisition of the endosymbiont and the radiation of the eukaryotes and therewith support an early acquisition of mitochondria in eukaryotic evolution. Technically, advancements in the reconstruction of the evolutionary trajectories of loss, replacement and gain of mitochondrial proteins depend on using profile-based homology detection methods for sequence analysis. We highlight the mitochondrial Holliday junction resolvase endonuclease, for which such methods have detected new "family members" and in which function differentiation is accompanied by the loss of catalytic residues for the original enzymatic function and the gain of a protein domain for the new function. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems.}, }
@article {pmid22900008, year = {2012}, author = {Rana, VS and Singh, ST and Priya, NG and Kumar, J and Rajagopal, R}, title = {Arsenophonus GroEL interacts with CLCuV and is localized in midgut and salivary gland of whitefly B. tabaci.}, journal = {PloS one}, volume = {7}, number = {8}, pages = {e42168}, pmid = {22900008}, issn = {1932-6203}, mesh = {Animals ; Bacterial Proteins/*metabolism ; Begomovirus/genetics/*metabolism ; Biodiversity ; Chaperonin 60/*metabolism ; DNA, Mitochondrial/genetics ; Enterobacteriaceae/classification/genetics/metabolism ; Escherichia coli Proteins/metabolism ; Gastrointestinal Tract/microbiology ; Gossypium/virology ; Hemiptera/classification/genetics/*microbiology/virology ; Phylogeny ; Plant Diseases/virology ; Protein Binding ; RNA, Ribosomal, 16S/genetics ; Salivary Glands/microbiology ; Symbiosis ; Viral Envelope Proteins/genetics/isolation &amp; purification/metabolism ; }, abstract = {Cotton leaf curl virus (CLCuV) (Gemininiviridae: Begomovirus) is the causative agent of leaf curl disease in cotton plants (Gossypium hirsutum). CLCuV is exclusively transmitted by the whitefly species B. tabaci (Gennadius) (Hemiptera: Alerodidae). B. tabaci contains several biotypes which harbor dissimilar bacterial endo-symbiotic community. It is reported that these bacterial endosymbionts produce a 63 kDa chaperon GroEL protein which binds to geminivirus particles and protects them from rapid degradation in gut and haemolymph. In biotype B, GroEL protein of Hamiltonella has been shown to interact with Tomato yellow leaf curl virus (TYLCV). The present study was initiated to find out whether endosymbionts of B. tabaci are similarly involved in CLCuV transmission in Sriganganagar (Rajasthan), an area endemic with cotton leaf curl disease. Biotype and endosymbiont diversity of B. tabaci were identified using MtCO1 and 16S rDNA genes respectively. Analysis of our results indicated that the collected B. tabaci population belong to AsiaII genetic group and harbor the primary endosymbiont Portiera and the secondary endosymbiont Arsenophonus. The GroEL proteins of Portiera and Arsenophonus were purified and in-vitro interaction studies were carried out using pull down and co-immunoprecipitation assays. In-vivo interaction was confirmed using yeast two hybrid system. In both in-vitro and in-vivo studies, the GroEL protein of Arsenophonus was found to be interacting with the CLCuV coat protein. Further, we also localized the presence of Arsenophonus in the salivary glands and the midgut of B. tabaci besides the already reported bacteriocytes. These results suggest the involvement of Arsenophonus in the transmission of CLCuV in AsiaII genetic group of B. tabaci.}, }
@article {pmid22897044, year = {2012}, author = {Rounds, MA and Crowder, CD and Matthews, HE and Philipson, CA and Scoles, GA and Ecker, DJ and Schutzer, SE and Eshoo, MW}, title = {Identification of endosymbionts in ticks by broad-range polymerase chain reaction and electrospray ionization mass spectrometry.}, journal = {Journal of medical entomology}, volume = {49}, number = {4}, pages = {843-850}, pmid = {22897044}, issn = {0022-2585}, support = {R43 AI077156/AI/NIAID NIH HHS/United States ; R44 AI077156/AI/NIAID NIH HHS/United States ; 2R44AI077156-02/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Ixodidae/*microbiology ; Larva/microbiology ; Nymph/microbiology ; Ovum/microbiology ; Polymerase Chain Reaction ; Rickettsia/isolation &amp; purification ; Species Specificity ; Spectrometry, Mass, Electrospray Ionization ; *Symbiosis ; }, abstract = {Many organisms, such as insects, filarial nematodes, and ticks, contain heritable bacterial endosymbionts that are often closely related to transmissible tickborne pathogens. These intracellular bacteria are sometimes unique to the host species, presumably due to isolation and genetic drift. We used a polymerase chain reaction/electrospray ionization-mass spectrometry assay designed to detect a wide range of vectorborne microorganisms to characterize endosymbiont genetic signatures from Amblyomma americanum (L.), Amblyomma maculatum Koch, Dermacentor andersoni Stiles, Dermacentor occidentalis Marx, Dermacentor variabilis (Say), Ixodes scapularis Say, Ixodes pacificus Cooley &amp; Kohls, Ixodes ricinus (L.), and Rhipicephalus sanguineus (Latreille) ticks collected at various sites and of different stages and both sexes. The assay combines the abilities to simultaneously detect pathogens and closely related endosymbionts and to identify tick species via characterization of their respective unique endosymbionts in a single test.}, }
@article {pmid22891065, year = {2012}, author = {Dziallas, C and Allgaier, M and Monaghan, MT and Grossart, HP}, title = {Act together-implications of symbioses in aquatic ciliates.}, journal = {Frontiers in microbiology}, volume = {3}, number = {}, pages = {288}, pmid = {22891065}, issn = {1664-302X}, abstract = {Mutual interactions in the form of symbioses can increase the fitness of organisms and provide them with the capacity to occupy new ecological niches. The formation of obligate symbioses allows for rapid evolution of new life forms including multitrophic consortia. Microbes are important components of many known endosymbioses and their short generation times and strong potential for genetic exchange may be important drivers of speciation. Hosts provide endo- and ectosymbionts with stable, nutrient-rich environments, and protection from grazers. This is of particular importance in aquatic ecosystems, which are often highly variable, harsh, and nutrient-deficient habitats. It is therefore not surprising that symbioses are widespread in both marine and freshwater environments. Symbioses in aquatic ciliates are good model systems for exploring symbiont-host interactions. Many ciliate species are globally distributed and have been intensively studied in the context of plastid evolution. Their relatively large cell size offers an ideal habitat for numerous microorganisms with different functional traits including commensalism and parasitism. Phagocytosis facilitates the formation of symbiotic relationships, particularly since some ingested microorganisms can escape the digestion. For example, photoautotrophic algae and methanogens represent endosymbionts that greatly extend the biogeochemical functions of their hosts. Consequently, symbiotic relationships between protists and prokaryotes are widespread and often result in new ecological functions of the symbiotic communities. This enables ciliates to thrive under a wide range of environmental conditions including ultraoligotrophic or anoxic habitats. We summarize the current understanding of this exciting research topic to identify the many areas in which knowledge is lacking and to stimulate future research by providing an overview on new methodologies and by formulating a number of emerging questions in this field.}, }
@article {pmid22889830, year = {2012}, author = {Godel, C and Kumar, S and Koutsovoulos, G and Ludin, P and Nilsson, D and Comandatore, F and Wrobel, N and Thompson, M and Schmid, CD and Goto, S and Bringaud, F and Wolstenholme, A and Bandi, C and Epe, C and Kaminsky, R and Blaxter, M and Mäser, P}, title = {The genome of the heartworm, Dirofilaria immitis, reveals drug and vaccine targets.}, journal = {FASEB journal : official publication of the Federation of American Societies for Experimental Biology}, volume = {26}, number = {11}, pages = {4650-4661}, pmid = {22889830}, issn = {1530-6860}, support = {095831//Wellcome Trust/United Kingdom ; G0900740/MRC_/Medical Research Council/United Kingdom ; /BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Anthelmintics/*pharmacology/therapeutic use ; Dirofilaria immitis/drug effects/*genetics/immunology/microbiology ; Dirofilariasis/drug therapy/*parasitology/prevention &amp; control ; Dog Diseases/drug therapy/*parasitology/prevention &amp; control ; Dogs ; Female ; Genetic Variation ; Genome, Bacterial ; *Genome, Helminth ; Male ; Phylogeny ; Proteome ; RNA, Helminth/chemistry ; Symbiosis ; Transcriptome/genetics ; Vaccines/*immunology ; Wolbachia/genetics/physiology ; }, abstract = {The heartworm Dirofilaria immitis is an important parasite of dogs. Transmitted by mosquitoes in warmer climatic zones, it is spreading across southern Europe and the Americas at an alarming pace. There is no vaccine, and chemotherapy is prone to complications. To learn more about this parasite, we have sequenced the genomes of D. immitis and its endosymbiont Wolbachia. We predict 10,179 protein coding genes in the 84.2 Mb of the nuclear genome, and 823 genes in the 0.9-Mb Wolbachia genome. The D. immitis genome harbors neither DNA transposons nor active retrotransposons, and there is very little genetic variation between two sequenced isolates from Europe and the United States. The differential presence of anabolic pathways such as heme and nucleotide biosynthesis hints at the intricate metabolic interrelationship between the heartworm and Wolbachia. Comparing the proteome of D. immitis with other nematodes and with mammalian hosts, we identify families of potential drug targets, immune modulators, and vaccine candidates. This genome sequence will support the development of new tools against dirofilariasis and aid efforts to combat related human pathogens, the causative agents of lymphatic filariasis and river blindness.}, }
@article {pmid22885633, year = {2012}, author = {Palmer, CV and Graham, E and Baird, AH}, title = {Immunity through early development of coral larvae.}, journal = {Developmental and comparative immunology}, volume = {38}, number = {2}, pages = {395-399}, doi = {10.1016/j.dci.2012.07.008}, pmid = {22885633}, issn = {1879-0089}, mesh = {Alveolata ; Animals ; Anthozoa/*growth &amp; development/*immunology/physiology ; Coral Reefs ; Fluorescence ; Larva/immunology ; Luminescent Proteins/metabolism ; Melanins/biosynthesis ; }, abstract = {As a determinant of survival, immunity is likely to be significant in enabling coral larvae to disperse and successfully recruit, however, whether reef-building coral larvae have immune defenses is unknown. We investigated the potential presence and variation in immunity in the lecithotrophic larvae of Acropora tenuis through larval development. Enzymes indicative of tyrosinase and laccase-type melanin-synthesis were quantified, and the concentration of three coral fluorescent proteins was measured over six developmental stages; egg, embryo, motile planula, planula post-exposure to crustose coralline algae (CCA; settlement cue), settled, settled post-exposure to Symbiodinium (endosymbiont). Both types of melanin-synthesis pathways and the three fluorescent proteins were present in A. tenuis throughout development. Laccase-type activity and red fluorescence increased following exposure of planula to CCA, whereas tyrosinase-type activity and cyan fluorescence increased following settlement. No change was detected in the measured parameters following exposure to Symbiodinium. This study is the first to document coral larval immune responses and suggests the melanin-synthesis pathways have disparate roles-the laccase-type potentially non-immunological and the tyrosinase-type in cytotoxic defense. Our results indicate that corals have the potential to resist infection from the earliest life history phase.}, }
@article {pmid22878693, year = {2012}, author = {Bennett, GM and Pantoja, NA and O'Grady, PM}, title = {Diversity and phylogenetic relationships of Wolbachia in Drosophila and other native Hawaiian insects.}, journal = {Fly}, volume = {6}, number = {4}, pages = {273-283}, pmid = {22878693}, issn = {1933-6942}, mesh = {Alleles ; Animals ; Drosophila/genetics/*microbiology ; Hawaii ; Insecta/classification/genetics/microbiology ; Likelihood Functions ; *Phylogeny ; Species Specificity ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {Wolbachia is a genus of parasitic alphaproteobacteria found in arthropods and nematodes, and represents on of the most common, widespread endosymbionts known. Wolbachia affects a variety of reproductive functions in its host (e.g., male killing, cytoplasmic incompatibility, parthenogenesis), which have the potential to dramatically impact host evolution and species formation. Here, we present the first broad-scale study to screen natural populations of native Hawaiian insects for Wolbachia, focusing on the endemic Diptera. Results indicate that Wolbachia infects native Hawaiian taxa, with alleles spanning phylogenetic supergroups, A and B. The overall frequency of Wolbachia incidene in Hawaiian insects was 14%. The incidence of infection in native Hawaiian Diptera was 11% for individuals and 12% for all species screened. Wolbachia was not detected in two large, widespread Hawaiian dipteran families-Dolichopodidae (44 spp screened) and Limoniidae (12 spp screened). Incidence of infection within endemic Hawaiian lineages that carry Wolbachia was 18% in Drosophilidae species, 25% in Caliphoridae species, > 90% in Nesophrosyne species, 20% in Drosophila dasycnemia and 100% in Nesophrosyne craterigena. Twenty unique alleles were recovered in this study, of which 18 are newly recorded. Screening of endemic populations of D. dasycnemia across Hawaii Island revealed 4 unique alleles. Phylogenetic relationships and allele diversity provide evidence for horizontal transfer of Wolbachia among Hawaiian arthropod lineages.}, }
@article {pmid22878556, year = {2012}, author = {Li, X and Nan, X and Wei, C and He, H}, title = {The gut bacteria associated with Camponotus japonicus Mayr with culture-dependent and DGGE methods.}, journal = {Current microbiology}, volume = {65}, number = {5}, pages = {610-616}, pmid = {22878556}, issn = {1432-0991}, mesh = {Animals ; Ants/*microbiology ; Bacteria/*classification/genetics/growth &amp; development/*isolation &amp; purification ; Culture Media/metabolism ; Denaturing Gradient Gel Electrophoresis ; Gastrointestinal Tract/*microbiology ; Molecular Sequence Data ; Phylogeny ; }, abstract = {The bacterial composition and distribution in the different gut regions of Camponotus japonicus were investigated using both culture-dependent method and culture-independent method of polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE). Five different bacterial strains were isolated using culture-dependent method, and they all belong to the phylum Firmicutes, including three genera of bacteria Bacillus, Paenibacillus, and Enterococcus. Bacillus cereus and Enterococcus mundtii were found in the midgut; Paenibacillus sp. was isolated from the hindgut; and the other two Bacillus spp. were isolated from the crop. Twelve distinct DGGE bands were found using PCR-DGGE method, and their sequences blasting analysis shows that they are members of the Proteobacteria and the Firmicutes, respectively, including three genera (Pseudomonas, Candidatus Blochmannia, Fructobacillus) and one uncultured bacterium, in which Pseudomonas was the most dominant bacteria group in all the three gut regions. According to the DGGE profile, the three gut regions had very similar gut communities, and all the DGGE bands were presented in the midgut and hindgut, while just two bands representing Blochmannia were not present in the crop. The results of our study indicate that the gut of C. japonicus harbors several other bacteria besides the obligate endosymbionts Blochmannia, and more work should be carried on to verify if they are common in the guts of other Camponotus ants.}, }
@article {pmid22876183, year = {2012}, author = {Le Clec'h, W and Braquart-Varnier, C and Raimond, M and Ferdy, JB and Bouchon, D and Sicard, M}, title = {High virulence of Wolbachia after host switching: when autophagy hurts.}, journal = {PLoS pathogens}, volume = {8}, number = {8}, pages = {e1002844}, pmid = {22876183}, issn = {1553-7374}, mesh = {Animals ; *Autophagy ; Central Nervous System/metabolism/microbiology/ultrastructure ; *Host-Pathogen Interactions ; Isopoda ; Rickettsiaceae Infections/*metabolism/microbiology ; Species Specificity ; Vacuoles/metabolism/microbiology/ultrastructure ; Wolbachia/*pathogenicity/*physiology/ultrastructure ; }, abstract = {Wolbachia are widespread endosymbionts found in a large variety of arthropods. While these bacteria are generally transmitted vertically and exhibit weak virulence in their native hosts, a growing number of studies suggests that horizontal transfers of Wolbachia to new host species also occur frequently in nature. In transfer situations, virulence variations can be predicted since hosts and symbionts are not adapted to each other. Here, we describe a situation where a Wolbachia strain (wVulC) becomes a pathogen when transfected from its native terrestrial isopod host species (Armadillidium vulgare) to another species (Porcellio d. dilatatus). Such transfer of wVulC kills all recipient animals within 75 days. Before death, animals suffer symptoms such as growth slowdown and nervous system disorders. Neither those symptoms nor mortalities were observed after injection of wVulC into its native host A. vulgare. Analyses of wVulC's densities in main organs including Central Nervous System (CNS) of both naturally infected A. vulgare and transfected P. d. dilatatus and A. vulgare individuals revealed a similar pattern of host colonization suggesting an overall similar resistance of both host species towards this bacterium. However, for only P. d. dilatatus, we observed drastic accumulations of autophagic vesicles and vacuoles in the nerve cells and adipocytes of the CNS from individuals infected by wVulC. The symptoms and mortalities could therefore be explained by this huge autophagic response against wVulC in P. d. dilatatus cells that is not triggered in A. vulgare. Our results show that Wolbachia (wVulC) can lead to a pathogenic interaction when transferred horizontally into species that are phylogenetically close to their native hosts. This change in virulence likely results from the autophagic response of the host, strongly altering its tolerance to the symbiont and turning it into a deadly pathogen.}, }
@article {pmid22875676, year = {2012}, author = {Tkach, VV and Schroeder, JA and Greiman, SE and Vaughan, JA}, title = {New genetic lineages, host associations and circulation pathways of Neorickettsia endosymbionts of digeneans.}, journal = {Acta parasitologica}, volume = {57}, number = {3}, pages = {285-292}, doi = {10.2478/s11686-012-0043-4}, pmid = {22875676}, issn = {1896-1851}, support = {R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/genetics ; Genetic Variation ; Neorickettsia/classification/*genetics/*isolation &amp; purification ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rhodopsins, Microbial/genetics ; Symbiosis/physiology ; Trematoda/*microbiology ; }, abstract = {Neorickettsia is a genus of intracellular bacteria endosymbiotic in digeneans that may also invade cells of vertebrates and are known to cause diseases of wildlife and humans. Herein, we report results of screening for Neorickettsia of an extensive collection of DNA extracts from adult and larval digeneans obtained from various vertebrates and mollusks in the United States. Seven isolates of Neorickettsia were detected by PCR and sequenced targeting a 527 bp long region of 16S rRNA. Sequence comparison and phylogenetic analysis demonstrated that four isolates matched published sequences of Neorickettsia risticii. Three other isolates, provisionally named "catfish agents 1 and 2" (obtained from Megalogonia ictaluri and Phyllodistomum lacustri, both parasitic in catfishes) and Neorickettsia sp. (obtained from cercariae of Diplostomum sp.), differed from previously known genotypes of Neorickettsia and are likely candidates for new species. All 7 isolates of Neorickettsia were obtained from digenean species and genera that were not previously reported as hosts of these bacteria. Members of four digenean families (Dicrocoeliidae, Heronimidae, Macroderoididae and Gorgoderidae) are reported as hosts of Neorickettsia for the first time. Our study reveals several new pathways of Neorickettsia circulation in nature. We have found for the first time a Neorickettsia from a digenean (dicrocoeliid Conspicuum icteridorum) with an entirely terrestrial life cycle. We found N. risticii in digeneans (Alloglossidium corti and Heronimus mollis) with entirely aquatic life cycles. Previously, this Neorickettsia species was known only from digeneans with aquatic/terrestrial life cycles. Our results suggest that our current knowledge of the diversity, host associations and circulation of neorickettsiae is far from satisfactory.}, }
@article {pmid22859592, year = {2012}, author = {Longdon, B and Jiggins, FM}, title = {Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?.}, journal = {Proceedings. Biological sciences}, volume = {279}, number = {1744}, pages = {3889-3898}, pmid = {22859592}, issn = {1471-2954}, support = {281668/ERC_/European Research Council/International ; }, mesh = {Animals ; Bacterial Physiological Phenomena ; Biodiversity ; *Biological Evolution ; Diptera/physiology/virology ; Drosophila melanogaster/physiology/virology ; Insecta/*genetics/physiology/*virology ; Reproduction ; Rhabdoviridae/genetics/*physiology ; Symbiosis ; }, abstract = {Insects are host to a wide range of vertically transmitted bacterial endosymbionts, but we know relatively little about their viral counterparts. Here, we discuss the vertically transmitted viral endosymbionts of insects, firstly examining the diversity of this group, and then focusing on the well-studied sigma viruses that infect dipterans. Despite limited sampling, evidence suggests that vertically transmitted viruses may be common in insects. Unlike bacteria, viruses can be transmitted through sperm and eggs, a trait that allows them to rapidly spread through host populations even when infection is costly to the host. Work on Drosophila melanogaster has shown that sigma viruses and their hosts are engaged in a coevolutionary arms race, in which the spread of resistance genes in the host population is followed by the spread of viral genotypes that can overcome host resistance. In the long-term, associations between sigma viruses and their hosts are unstable, and the viruses persist by occasionally switching to new host species. It therefore seems likely that viral endosymbionts have major impacts on the evolution and ecology of insects.}, }
@article {pmid22843586, year = {2012}, author = {Huang, CY and Sabree, ZL and Moran, NA}, title = {Genome sequence of Blattabacterium sp. strain BGIGA, endosymbiont of the Blaberus giganteus cockroach.}, journal = {Journal of bacteriology}, volume = {194}, number = {16}, pages = {4450-4451}, pmid = {22843586}, issn = {1098-5530}, support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/metabolism ; Animals ; Bacteroidetes/*genetics/isolation &amp; purification/metabolism/physiology ; Cockroaches/microbiology ; DNA, Bacterial/*chemistry/*genetics ; *Genome, Bacterial ; Molecular Sequence Data ; Nitrogen Compounds/metabolism ; *Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Cockroaches harbor the obligate flavobacterial endosymbiont Blattabacterium sp., which resides within the host's bacteriocytes and can recycle ammonia and urea nitrogenous wastes into amino acids for the host. We report the complete genome sequence of the Blattabacterium sp. associated with the giant roach Blaberus giganteus.}, }
@article {pmid22843518, year = {2012}, author = {Osborne, SE and Iturbe-Ormaetxe, I and Brownlie, JC and O'Neill, SL and Johnson, KN}, title = {Antiviral protection and the importance of Wolbachia density and tissue tropism in Drosophila simulans.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {19}, pages = {6922-6929}, pmid = {22843518}, issn = {1098-5336}, mesh = {Animal Structures/microbiology ; Animals ; Anti-Bacterial Agents/administration &amp; dosage ; Bacterial Load ; Dengue Virus/*growth &amp; development/immunology ; Drosophila/*microbiology/*virology ; Tetracycline/administration &amp; dosage ; Wolbachia/drug effects/*growth &amp; development/isolation &amp; purification ; }, abstract = {Wolbachia, a maternally transmitted endosymbiont of insects, is increasingly being seen as an effective biological control agent that can interfere with transmission of pathogens, including dengue virus. However, the mechanism of antiviral protection is not well understood. The density and distribution of Wolbachia in host tissues have been implicated as contributing factors by previous studies with both mosquitoes and flies. Drosophila flies infected with five diverse strains of Wolbachia were screened for the ability to mediate antiviral protection. The three protective Wolbachia strains were more closely related and occurred at a higher density within whole flies than the two nonprotective Wolbachia strains. In this study, to further investigate the relationship between whole-fly Wolbachia density and the ability to mediate antiviral protection, tetracycline was used to decrease the abundance of the high-density, protective Wolbachia strain wAu prior to viral challenge. Antiviral protection was lost when the density of the protective Wolbachia strain was decreased to an abundance similar to that of nonprotective Wolbachia strains. We determined the Wolbachia density and distribution in tissues of the same five fly-Wolbachia combinations as used previously. The Wolbachia density within the head, gut, and Malpighian tubules correlated with the ability to mediate antiviral protection. These findings may facilitate the development of Wolbachia biological control strategies and help to predict host-Wolbachia pairings that may interfere with virus-induced pathology.}, }
@article {pmid22837851, year = {2012}, author = {Ross, L and Shuker, DM and Normark, BB and Pen, I}, title = {The role of endosymbionts in the evolution of haploid-male genetic systems in scale insects (Coccoidea).}, journal = {Ecology and evolution}, volume = {2}, number = {5}, pages = {1071-1081}, pmid = {22837851}, issn = {2045-7758}, abstract = {There is an extraordinary diversity in genetic systems across species, but this variation remains poorly understood. In part, this is because the mechanisms responsible for transitions between systems are often unknown. A recent hypothesis has suggested that conflict between hosts and endosymbiotic microorganisms over transmission could drive the transition from diplodiploidy to systems with male haploidy (haplodiploidy, including arrhenotoky and paternal genome elimination [PGE]). Here, we present the first formal test of this idea with a comparative analysis across scale insects (Hemiptera: Coccoidea). Scale insects are renowned for their large variation in genetic systems, and multiple transitions between diplodiploidy and haplodiploidy have taken place within this group. Additionally, most species rely on endosymbiotic microorganisms to provide them with essential nutrients lacking in their diet. We show that species harboring endosymbionts are indeed more likely to have a genetic system with male haploidy, which supports the hypothesis that endosymbionts might have played a role in the transition to haplodiploidy. We also extend our analysis to consider the relationship between endosymbiont presence and transitions to parthenogenesis. Although in scale insects there is no such overall association, species harboring eukaryote endosymbionts were more likely to be parthenogenetic than those with bacterial symbionts. These results support the idea that intergenomic conflict can drive the evolution of novel genetic systems and affect host reproduction.}, }
@article {pmid22835786, year = {2012}, author = {Wernegreen, JJ}, title = {Endosymbiosis.}, journal = {Current biology : CB}, volume = {22}, number = {14}, pages = {R555-61}, doi = {10.1016/j.cub.2012.06.010}, pmid = {22835786}, issn = {1879-0445}, mesh = {Archaea/genetics/physiology ; Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Biodiversity ; *Biological Evolution ; Eukaryota/genetics/*physiology ; Nitrogen Fixation ; Nutritional Physiological Phenomena ; Photosynthesis ; *Symbiosis ; }, abstract = {The phenomenon of endosymbiosis, or one organism living within another, has deeply impacted the evolution of life and continues to shape the ecology of countless species. Traditionally, biologists have viewed evolution as a largely bifurcating pattern, reflecting mutations and other changes in existing genetic information and the occasional speciation and divergence of lineages. While lineage bifurcation has clearly been important in evolution, the merging of two lineages through endosymbiosis has also made profound contributions to evolutionary novelty. Mitochondria and chloroplasts are relicts of ancient bacterial endosymbionts that ultimately extended the range of acceptable habitats for life by allowing hosts to thrive in the presence of oxygen and to convert light into energy. Today, the sheer abundance of endosymbiotic relationships across diverse host lineages and habitats testifies to their continued significance.}, }
@article {pmid22835476, year = {2013}, author = {Doudoumis, V and Alam, U and Aksoy, E and Abd-Alla, AM and Tsiamis, G and Brelsfoard, C and Aksoy, S and Bourtzis, K}, title = {Tsetse-Wolbachia symbiosis: comes of age and has great potential for pest and disease control.}, journal = {Journal of invertebrate pathology}, volume = {112 Suppl}, number = {0}, pages = {S94-103}, pmid = {22835476}, issn = {1096-0805}, support = {AI06892/AI/NIAID NIH HHS/United States ; R03TW008413/TW/FIC NIH HHS/United States ; R03 TW008755/TW/FIC NIH HHS/United States ; D43 TW007391/TW/FIC NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; D43TW007391/TW/FIC NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; R03 TW008413/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Gene Transfer, Horizontal/genetics ; Humans ; Pest Control, Biological/*methods ; *Symbiosis/genetics ; Trypanosomiasis, African/prevention &amp; control ; Tsetse Flies/genetics/*microbiology ; *Wolbachia/genetics ; }, abstract = {Tsetse flies (Diptera: Glossinidae) are the sole vectors of African trypanosomes, the causative agent of sleeping sickness in human and nagana in animals. Like most eukaryotic organisms, Glossina species have established symbiotic associations with bacteria. Three main symbiotic bacteria have been found in tsetse flies: Wigglesworthia glossinidia, an obligate symbiotic bacterium, the secondary endosymbiont Sodalis glossinidius and the reproductive symbiont Wolbachia pipientis. In the present review, we discuss recent studies on the detection and characterization of Wolbachia infections in Glossina species, the horizontal transfer of Wolbachia genes to tsetse chromosomes, the ability of this symbiont to induce cytoplasmic incompatibility in Glossina morsitans morsitans and also how new environment-friendly tools for disease control could be developed by harnessing Wolbachia symbiosis.}, }
@article {pmid22834753, year = {2012}, author = {Mondo, SJ and Toomer, KH and Morton, JB and Lekberg, Y and Pawlowska, TE}, title = {Evolutionary stability in a 400-million-year-old heritable facultative mutualism.}, journal = {Evolution; international journal of organic evolution}, volume = {66}, number = {8}, pages = {2564-2576}, doi = {10.1111/j.1558-5646.2012.01611.x}, pmid = {22834753}, issn = {1558-5646}, mesh = {Burkholderiaceae/*genetics/physiology ; *Evolution, Molecular ; Fossils ; *Genes, Bacterial ; *Genes, Fungal ; Glomeromycota/*genetics/physiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Spores, Fungal/genetics ; *Symbiosis ; }, abstract = {Many eukaryotes interact with heritable endobacteria to satisfy diverse metabolic needs. Some of these interactions are facultative symbioses, in which one partner is not essential to the other. Facultative symbioses are expected to be transitional stages along an evolutionary trajectory toward obligate relationships. We tested this evolutionary theory prediction in Ca. Glomeribacter gigasporarum, nonessential endosymbionts of arbuscular mycorrhizal fungi (Glomeromycota). We found that heritable facultative mutualisms can be both ancient and evolutionarily stable. We detected significant patterns of codivergence between the partners that we would only expect in obligate associations. Using codiverging partner pairs and the fungal fossil record, we established that the Glomeromycota-Glomeribacter symbiosis is at least 400 million years old. Despite clear signs of codivergence, we determined that the Glomeribacter endobacteria engage in recombination and host switching, which display patterns indicating that the association is not evolving toward reciprocal dependence. We postulate that low frequency of recombination in heritable endosymbionts together with host switching stabilize facultative mutualisms over extended evolutionary times.}, }
@article {pmid22831171, year = {2012}, author = {Brennan, LJ and Haukedal, JA and Earle, JC and Keddie, B and Harris, HL}, title = {Disruption of redox homeostasis leads to oxidative DNA damage in spermatocytes of Wolbachia-infected Drosophila simulans.}, journal = {Insect molecular biology}, volume = {21}, number = {5}, pages = {510-520}, doi = {10.1111/j.1365-2583.2012.01155.x}, pmid = {22831171}, issn = {1365-2583}, mesh = {8-Hydroxy-2'-Deoxyguanosine ; Animals ; Antioxidants ; Cell Line ; Comet Assay ; *DNA Damage ; Deoxyguanosine/analogs &amp; derivatives/analysis ; Drosophila/metabolism/*microbiology ; Female ; Glutathione ; Homeostasis ; Male ; *Oxidative Stress ; Spermatocytes/metabolism ; *Spermatogenesis ; Superoxide Dismutase/metabolism ; Testis/metabolism/microbiology ; Wolbachia/*physiology ; }, abstract = {Molecular interactions between symbiotic bacteria and their animal hosts are, as yet, poorly understood. The most widespread bacterial endosymbiont, Wolbachia pipientis, occurs in high density in testes of infected Drosophila simulans and causes cytoplasmic incompatibility (CI), a form of male-derived zygotic lethality. Wolbachia grow and divide within host vacuoles that generate reactive oxygen species (ROS), which in turn stimulate the up-regulation of antioxidant enzymes. These enzymes appear to protect the host from ROS-mediated damage, as there is no obvious fitness cost to Drosophila carrying Wolbachia infections. We have now determined that DNA from Wolbachia-infected mosquito Aedes albopictus (Aa23) cells shows a higher amount of the base 8-oxo-deoxyguanosine, a marker of oxidative DNA damage, than DNA from uninfected cells, and that Wolbachia infection in D. simulans is associated with an increase in DNA strand breaks in meiotic spermatocytes. Feeding exogenous antioxidants to male and female D. simulans dramatically increased Wolbachia numbers with no obvious effects on host fitness. These results suggest that ROS-induced DNA damage in sperm nuclei may contribute to the modification characteristic of CI expression in Wolbachia-infected males and that Wolbachia density is sensitive to redox balance in these flies.}, }
@article {pmid22821906, year = {2012}, author = {Dorn, GW}, title = {Inflame on!: mitochondrial escape provokes cytokine storms that doom the heart.}, journal = {Circulation research}, volume = {111}, number = {3}, pages = {271-273}, doi = {10.1161/CIRCRESAHA.112.275867}, pmid = {22821906}, issn = {1524-4571}, abstract = {Mitochondria are derived from primordial bacterial endosymbionts and retain partial genomes. In mammalian cells, damaged or dysfunctional mitochondria are recognized, targeted for elimination, then neatly packaged and eliminated via mitophagy. A recent paper from Oka et al describes how interrupting normal mitophagic mitochondrial DNA degradation after pressure overload can activate Toll-like receptor-9 mediated innate immunity, causing myocardial inflammation that contributes to cardiomyopathic decompensation.}, }
@article {pmid22815933, year = {2012}, author = {Shrivastava, N and Nag, JK and Misra-Bhattacharya, S}, title = {Molecular characterization of NAD+-dependent DNA ligase from Wolbachia endosymbiont of lymphatic filarial parasite Brugia malayi.}, journal = {PloS one}, volume = {7}, number = {7}, pages = {e41113}, pmid = {22815933}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Animals ; Blotting, Western ; Brugia malayi/metabolism ; Catalysis ; Circular Dichroism ; DNA Ligases/*chemistry ; Female ; Immunoblotting ; Male ; Mice ; Mice, Inbred BALB C ; Microscopy, Confocal/methods ; Molecular Sequence Data ; Phylogeny ; Recombinant Proteins/metabolism ; Sequence Homology, Amino Acid ; Spectrometry, Fluorescence/methods ; Wolbachia/*metabolism ; }, abstract = {The lymphatic filarial parasite, Brugia malayi contains Wolbachia endobacteria that are essential for development, viability and fertility of the parasite. Therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. NAD(+)-dependent DNA ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in DNA replication, recombination and DNA repair. We report here the cloning, expression and purification of NAD(+)-dependent DNA ligase of Wolbachia endosymbiont of B. malayi (wBm-LigA) for its molecular characterization. wBm-LigA has all the domains that are present in nearly all the eubacterial NAD(+)-dependent DNA ligases such as N-terminal adenylation domain, OB fold, helix-hairpin-helix (HhH) and BRCT domain except zinc-binding tetracysteine domain. The purified recombinant protein (683-amino acid) was found to be biochemically active and was present in its native form as revealed by the circular dichroism and fluorescence spectra. The purified recombinant enzyme was able to catalyze intramolecular strand joining on a nicked DNA as well as intermolecular joining of the cohesive ends of BstEII restricted lamda DNA in an in vitro assay. The enzyme was localized in the various life-stages of B. malayi parasites by immunoblotting and high enzyme expression was observed in Wolbachia within B. malayi microfilariae and female adult parasites along the hypodermal chords and in the gravid portion as evident by the confocal microscopy. Ours is the first report on this enzyme of Wolbachia and these findings would assist in validating the antifilarial drug target potential of wBm-LigA in future studies.}, }
@article {pmid22811248, year = {2012}, author = {Bednarz, VN and Naumann, MS and Niggl, W and Wild, C}, title = {Inorganic nutrient availability affects organic matter fluxes and metabolic activity in the soft coral genus Xenia.}, journal = {The Journal of experimental biology}, volume = {215}, number = {Pt 20}, pages = {3672-3679}, doi = {10.1242/jeb.072884}, pmid = {22811248}, issn = {1477-9145}, mesh = {Animals ; Anthozoa/*metabolism ; Carbon/*metabolism ; Coral Reefs ; *Ecosystem ; Microalgae/physiology ; Organic Chemicals ; Particulate Matter ; *Phosphates ; *Quaternary Ammonium Compounds ; Seawater ; Symbiosis ; }, abstract = {The release of organic matter (OM) by scleractinian corals represents a key physiological process that importantly contributes to coral reef ecosystem functioning, and is affected by inorganic nutrient availability. Although OM fluxes have been studied for several dominant reef taxa, no information is available for soft corals, one of the major benthic groups in tropical reef environments. Thus, this study investigates OM fluxes along with other key physiological parameters (i.e. photosynthesis, respiration and chlorophyll a tissue content) in the common soft coral genus Xenia after a 4-week exposure period to elevated ammonium (N; 20.0 μmol l(-1)), phosphate (P; 2.0 μmol l(-1)) and combined inorganic nutrient enrichment treatment (N+P). Corals maintained without nutrient enrichment served as non-treated controls and revealed constant uptake rates for particulate organic carbon (POC) (-0.315±0.161 mg POC m(-2) coral surface area h(-1)), particulate nitrogen (PN) (-0.053±0.018 mg PN m(-2) h(-1)) and dissolved organic carbon (DOC) (-4.8±2.1 mg DOC m(-2) h(-1)). Although DOC uptake significantly increased in the N treatment, POC flux was not affected. The P treatment significantly enhanced PN release as well as photosynthesis and respiration rates, suggesting that autotrophic carbon acquisition of zooxanthellae endosymbionts influences OM fluxes by the coral host. Our physiological findings confirm the significant effect of inorganic nutrient availability on OM fluxes and key metabolic processes for the soft coral Xenia, and provide the first clues on OM cycles initiated by soft corals in reef environments exposed to ambient and elevated inorganic nutrient concentrations.}, }
@article {pmid22809388, year = {2013}, author = {Koga, R and Nikoh, N and Matsuura, Y and Meng, XY and Fukatsu, T}, title = {Mealybugs with distinct endosymbiotic systems living on the same host plant.}, journal = {FEMS microbiology ecology}, volume = {83}, number = {1}, pages = {93-100}, doi = {10.1111/j.1574-6941.2012.01450.x}, pmid = {22809388}, issn = {1574-6941}, mesh = {Animals ; Betaproteobacteria/genetics/*growth &amp; development ; DNA, Bacterial/genetics ; *Ecosystem ; Evolution, Molecular ; Gammaproteobacteria/genetics/*growth &amp; development ; Genetic Speciation ; Hemiptera/*microbiology ; Phylogeny ; Plants ; Species Specificity ; *Symbiosis ; }, abstract = {Mealybugs (Homoptera: Coccoidea: Pseudococcidae) possess a large bacteriome consisting of a number of bacteriocytes whose cytoplasm is populated by endosymbiotic bacteria. In many mealybugs of the subfamily Pseudococcinae, a peculiar endosymbiotic configuration has been identified: within the bacteriocytes, the primary betaproteobacterial endosymbiont Tremblaya princeps endocellularly harbor secondary gammaproteobacterial endosymbionts in a nested manner. Meanwhile, some mealybugs of the subfamily Phenacoccinae are associated only with a betaproteobacterial endosymbiont, designated as Tremblaya phenacola, which constitutes a distinct sister clade of T. princeps. However, cytological configuration of the endosymbiotic system in the phenacoccine mealybugs has not been established. Here, we investigated the endosymbiotic systems of the azalea mealybugs Crisicoccus azaleae (Pseudococcinae) and Phenacoccus azaleae (Phenacoccinae) living on the same host plants. Crisicoccus azaleae possessed a nested endosymbiotic system with T. princeps within the bacteriocyte cytoplasm and itself endocellularly harboring gammaproteobacterial cells, whereas P. azaleae exhibited a simple endosymbiotic system in which T. phenacola cells are localized within the bacteriocytes without additional gammaproteobacterial associates. Considering that these mealybugs live on the identical plant phloem sap, these different endosymbiotic consortia likely play similar biological roles for their host insects. The findings presented here should be helpful for future functional and comparative genomics toward elucidating evolutionary pathways of mealybugs and their endosymbionts.}, }
@article {pmid22809041, year = {2012}, author = {Keshavmurthy, S and Hsu, CM and Kuo, CY and Meng, PJ and Wang, JT and Chen, CA}, title = {Symbiont communities and host genetic structure of the brain coral Platygyra verweyi, at the outlet of a nuclear power plant and adjacent areas.}, journal = {Molecular ecology}, volume = {21}, number = {17}, pages = {4393-4407}, doi = {10.1111/j.1365-294X.2012.05704.x}, pmid = {22809041}, issn = {1365-294X}, mesh = {Acclimatization/genetics ; Animals ; Anthozoa/*genetics/microbiology ; DNA, Protozoan/genetics ; DNA, Ribosomal Spacer/genetics ; Dinoflagellida/genetics/*physiology ; *Genetics, Population ; *Nuclear Power Plants ; *Symbiosis ; Taiwan ; Temperature ; }, abstract = {In the context of rising seawater temperatures associated with climate change, the issue of whether coral holobionts deal with this challenge by shuffling their associations with stress- and/or heat-tolerant Symbiodinium, by generating heat-resistant host genotypes, or both is important for coral survival. In this study, the composition of communities of the endosymbiont Symbiodinium and the population genetics of the coral host Platygyra verweyi were examined in a reef impacted by hot-water discharged from the outlet of a nuclear power plant in operation in Kenting, Southern Taiwan since 1984. The water at this site is 2.0-3.0 °C warmer than adjacent reefs in summer, which have an average seawater temperature of 29.0 °C. The data were compared with those for the same species at other sites within 12 km of the outlet site. Platygyra verwyei was associated with one or both of Symbiodinium types C3 (heat sensitive) and D1a (heat tolerant) at all sites with the latter being the dominant at the nuclear power plant outlet. The proportion of C3 in populations increased gradually with increasing distance from the hot-water discharge. Genetic analysis of the Platygyra verweyi host using mitochondrial and nuclear markers showed no genetic differentiation among sites. Changes in the composition of Symbiodinium types associated with P. verweyi among closely located sites in Kenting suggested that this coral might have acclimatized to the constant thermal stress by selective association with heat-tolerant Symbiodinium types, whereas the role of the host in adaptation was inconclusive.}, }
@article {pmid22806335, year = {2012}, author = {Zhu, LY and Zhang, KJ and Zhang, YK and Ge, C and Gotoh, T and Hong, XY}, title = {Wolbachia strengthens cardinium-induced cytoplasmic incompatibility in the spider mite Tetranychus piercei McGregor.}, journal = {Current microbiology}, volume = {65}, number = {5}, pages = {516-523}, pmid = {22806335}, issn = {1432-0991}, mesh = {Animals ; Bacteroidetes/genetics/*physiology ; Cytoplasm/genetics/*microbiology/physiology ; Female ; Male ; Reproduction ; Symbiosis ; Tetranychidae/genetics/*microbiology/*physiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia and Cardinium are maternally inherited intracellular bacteria that can manipulate the reproduction of their arthropod hosts, such as by inducing cytoplasmic incompatibility (CI). Although the reproductive alteration induced by Wolbachia or Cardinium have been well investigated, the effects of these two endosymbionts co-infecting the same host are poorly understood. We found that Tetranychus piercei McGregor is naturally infected with Wolbachia and Cardinium. We performed all possible crossing combinations using naturally infected and cured strains, and the results show that Wolbachia induced a weak level of CI, while Cardinium-infected and doubly infected males caused severe CI. Wolbachia and Cardinium could not rescue CI each other; however, Wolbachia boosted the expression of Cardinium-induced CI. Quantitative PCR results demonstrated that CI was associated with the infection density of Wolbachia and Cardinium.}, }
@article {pmid22804907, year = {2012}, author = {White, CE and Gavina, JM and Morton, R and Britz-McKibbin, P and Finan, TM}, title = {Control of hydroxyproline catabolism in Sinorhizobium meliloti.}, journal = {Molecular microbiology}, volume = {85}, number = {6}, pages = {1133-1147}, doi = {10.1111/j.1365-2958.2012.08164.x}, pmid = {22804907}, issn = {1365-2958}, mesh = {Gene Expression Profiling ; Gene Order ; Genetic Loci ; Hydroxyproline/*metabolism ; Ketoglutaric Acids/metabolism ; Metabolic Networks and Pathways/*genetics ; Pseudomonas/genetics ; Sinorhizobium meliloti/*genetics/*metabolism ; }, abstract = {Hydroxyproline (Hyp) in decaying organic matter is a rich source of carbon and nitrogen for microorganisms. A bacterial pathway for Hyp catabolism is known; however, genes and function relationships are not established. In the pathway, trans-4-hydroxy-L-proline (4-L-Hyp) is epimerized to cis-4-hydroxy-D-proline (4-D-Hyp), and then, in three enzymatic reactions, the D-isomer is converted via Δ-pyrroline-4-hydroxy-2-carboxylate (HPC) and α-ketoglutarate semialdehyde (KGSA) to α-ketoglutarate (KG). Here a transcriptional analysis of cells growing on 4-L-Hyp, and the regulation and functions of genes from a Hyp catabolism locus of the legume endosymbiont Sinorhizobium meliloti are reported. Fourteen hydroxyproline catabolism genes (hyp), in five transcripts hypR, hypD, hypH, hypST and hypMNPQO(RE)XYZ, were negatively regulated by hypR. hypRE was shown to encode 4-hydroxyproline 2-epimerase and a hypRE mutant grew with 4-D-Hyp but not 4-L-Hyp. hypO, hypD and hypH are predicted to encode 4-D-Hyp oxidase, HPC deaminase and α-KGSA dehydrogenase respectively. The functions for hypS, hypT, hypX, hypY and hypZ remain to be determined. The data suggest 4-Hyp is converted to the tricarboxylic acid cycle intermediate α-ketoglutarate via the pathway established biochemically for Pseudomonas. This report describes the first molecular characterization of a Hyp catabolism locus.}, }
@article {pmid22792163, year = {2012}, author = {Puill-Stephan, E and Seneca, FO and Miller, DJ and van Oppen, MJ and Willis, BL}, title = {Expression of putative immune response genes during early ontogeny in the coral Acropora millepora.}, journal = {PloS one}, volume = {7}, number = {7}, pages = {e39099}, pmid = {22792163}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*genetics/*immunology ; Crosses, Genetic ; Gene Expression Profiling ; *Gene Expression Regulation ; Immunity/genetics ; }, abstract = {BACKGROUND: Corals, like many other marine invertebrates, lack a mature allorecognition system in early life history stages. Indeed, in early ontogeny, when corals acquire and establish associations with various surface microbiota and dinoflagellate endosymbionts, they do not efficiently distinguish between closely and distantly related individuals from the same population. However, very little is known about the molecular components that underpin allorecognition and immunity responses or how they change through early ontogeny in corals.<br><br>Patterns in the expression of four putative immune response genes (apextrin, complement C3, and two CELIII type lectin genes) were examined in juvenile colonies of Acropora millepora throughout a six-month post-settlement period using quantitative real-time PCR (qPCR). Expression of a CELIII type lectin gene peaked in the fourth month for most of the coral juveniles sampled and was significantly higher at this time than at any other sampling time during the six months following settlement. The timing of this increase in expression levels of putative immune response genes may be linked to allorecognition maturation which occurs around this time in A. millepora. Alternatively, the increase may represent a response to immune challenges, such as would be involved in the recognition of symbionts (such as Symbiodinium spp. or bacteria) during winnowing processes as symbioses are fine-tuned.<br><br>CONCLUSIONS/SIGNIFICANCE: Our data, although preliminary, are consistent with the hypothesis that lectins may play an important role in the maturation of allorecognition responses in corals. The co-expression of lectins with apextrin during development of coral juveniles also raises the possibility that these proteins, which are components of innate immunity in other invertebrates, may influence the innate immune systems of corals through a common pathway or system. However, further studies investigating the expression of these genes in alloimmune-challenged corals are needed to further clarify emerging evidence of a complex innate immunity system in corals.}, }
@article {pmid22791238, year = {2013}, author = {Correa, AM and Welsh, RM and Vega Thurber, RL}, title = {Unique nucleocytoplasmic dsDNA and +ssRNA viruses are associated with the dinoflagellate endosymbionts of corals.}, journal = {The ISME journal}, volume = {7}, number = {1}, pages = {13-27}, pmid = {22791238}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/physiology/*virology ; *Coral Reefs ; Dinoflagellida/classification/genetics/physiology/*virology ; Humans ; Phycodnaviridae/classification/genetics/*isolation &amp; purification ; Phylogeny ; RNA Viruses/classification/genetics/*isolation &amp; purification ; Symbiosis ; }, abstract = {The residence of dinoflagellate algae (genus: Symbiodinium) within scleractinian corals is critical to the construction and persistence of tropical reefs. In recent decades, however, acute and chronic environmental stressors have frequently destabilized this symbiosis, ultimately leading to coral mortality and reef decline. Viral infection has been suggested as a trigger of coral-Symbiodinium dissociation; knowledge of the diversity and hosts of coral-associated viruses is critical to evaluating this hypothesis. Here, we present the first genomic evidence of viruses associated with Symbiodinium, based on the presence of transcribed +ss (single-stranded) RNA and ds (double-stranded) DNA virus-like genes in complementary DNA viromes of the coral Montastraea cavernosa and expressed sequence tag (EST) libraries generated from Symbiodinium cultures. The M. cavernosa viromes contained divergent viral sequences similar to the major capsid protein of the dinoflagellate-infecting +ssRNA Heterocapsa circularisquama virus, suggesting a highly novel dinornavirus could infect Symbiodinium. Further, similarities to dsDNA viruses dominated (∼69%) eukaryotic viral similarities in the M. cavernosa viromes. Transcripts highly similar to eukaryotic algae-infecting phycodnaviruses were identified in the viromes, and homologs to these sequences were found in two independently generated Symbiodinium EST libraries. Phylogenetic reconstructions substantiate that these transcripts are undescribed and distinct members of the nucleocytoplasmic large DNA virus (NCLDVs) group. Based on a preponderance of evidence, we infer that the novel NCLDVs and RNA virus described here are associated with the algal endosymbionts of corals. If such viruses disrupt Symbiodinium, they are likely to impact the flexibility and/or stability of coral-algal symbioses, and thus long-term reef health and resilience.}, }
@article {pmid22778662, year = {2012}, author = {Rezzonico, F and Smits, TH and Duffy, B}, title = {Detection of AI-2 receptors in genomes of Enterobacteriaceae suggests a role of type-2 quorum sensing in closed ecosystems.}, journal = {Sensors (Basel, Switzerland)}, volume = {12}, number = {5}, pages = {6645-6665}, pmid = {22778662}, issn = {1424-8220}, mesh = {*Ecosystem ; Enterobacteriaceae/genetics/*metabolism/physiology ; *Genome, Bacterial ; Homoserine/*analogs &amp; derivatives/metabolism ; Lactones/*metabolism ; *Quorum Sensing ; Receptors, Cell Surface/*metabolism ; }, abstract = {The LuxS enzyme, an S-ribosyl-homocysteine lyase, catalyzes the production of the signal precursor for autoinducer-2 mediated quorum sensing (QS-2) in Vibrio. Its widespread occurrence among bacteria is often considered the evidence for a universal language for interspecies communication. Presence of the luxS gene and production of the autoinducer-2 (AI-2) signal have repeatedly been the only evidences presented to assign a functional QS-2 to the most diverse species. In fact, LuxS has a primary metabolic role as part of the activated methyl cycle. In this review we have analyzed the distribution of QS-2 related genes in Enterobacteriaceae by moving the focus of the investigation from AI-2 production to the detection of potential AI-2 receptors. The latter are common in pathogens or endosymbionts of animals, but were also found in a limited number of Enterobacteriaceae of the genera Enterobacter, Klebsiella, and Pantoea that live in close association with plants or fungi. Although a precise function of QS-2 in these species has not been identified, they all show an endophytic or endosymbiontic lifestyle that suggests a role of type-2 quorum sensing in the adaptation to closed ecosystems.}, }
@article {pmid22773814, year = {2012}, author = {Bonomi, HR and Posadas, DM and Paris, G and Carrica, Mdel C and Frederickson, M and Pietrasanta, LI and Bogomolni, RA and Zorreguieta, A and Goldbaum, FA}, title = {Light regulates attachment, exopolysaccharide production, and nodulation in Rhizobium leguminosarum through a LOV-histidine kinase photoreceptor.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, number = {30}, pages = {12135-12140}, pmid = {22773814}, issn = {1091-6490}, support = {//Howard Hughes Medical Institute/United States ; }, mesh = {Amino Acid Sequence ; Bacterial Adhesion/*physiology/radiation effects ; Base Sequence ; Biofilms/growth &amp; development ; Blotting, Western ; Flagella/metabolism ; Gentian Violet ; Histidine Kinase ; *Light ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; Peas/*microbiology ; Photoreceptors, Microbial/*metabolism ; Plant Root Nodulation/*physiology/radiation effects ; Polysaccharides, Bacterial/metabolism ; Protein Kinases/genetics/metabolism ; Protein Structure, Tertiary/genetics ; Real-Time Polymerase Chain Reaction ; Rhizobium leguminosarum/*physiology/radiation effects/ultrastructure ; Sequence Alignment ; Sequence Analysis, DNA ; Statistics, Nonparametric ; *Symbiosis ; }, abstract = {Rhizobium leguminosarum is a soil bacterium that infects root hairs and induces the formation of nitrogen-fixing nodules on leguminous plants. Light, oxygen, and voltage (LOV)-domain proteins are blue-light receptors found in higher plants and many algae, fungi, and bacteria. The genome of R. leguminosarum bv. viciae 3841, a pea-nodulating endosymbiont, encodes a sensor histidine kinase containing a LOV domain at the N-terminal end (R-LOV-HK). R-LOV-HK has a typical LOV domain absorption spectrum with broad bands in the blue and UV-A regions and shows a truncated photocycle. Here we show that the R-LOV-HK protein regulates attachment to an abiotic surface and production of flagellar proteins and exopolysaccharide in response to light. Also, illumination of bacterial cultures before inoculation of pea roots increases the number of nodules per plant and the number of intranodular bacteroids. The effects of light on nodulation are dependent on a functional lov gene. The results presented in this work suggest that light, sensed by R-LOV-HK, is an important environmental factor that controls adaptive responses and the symbiotic efficiency of R. leguminosarum.}, }
@article {pmid22773070, year = {2013}, author = {Tomanović, S and Chochlakis, D and Radulović, Z and Milutinović, M and Cakić, S and Mihaljica, D and Tselentis, Y and Psaroulaki, A}, title = {Analysis of pathogen co-occurrence in host-seeking adult hard ticks from Serbia.}, journal = {Experimental &amp; applied acarology}, volume = {59}, number = {3}, pages = {367-376}, pmid = {22773070}, issn = {1572-9702}, mesh = {Anaplasma/isolation &amp; purification ; Animals ; Arthropod Vectors/*microbiology ; Babesia/isolation &amp; purification ; Bacterial Infections/*epidemiology ; Bartonella/isolation &amp; purification ; Borrelia burgdorferi/isolation &amp; purification ; Coinfection/epidemiology ; Coxiella burnetii/isolation &amp; purification ; Francisella tularensis/isolation &amp; purification ; Ixodidae/*microbiology ; Rickettsia/isolation &amp; purification ; Serbia/epidemiology ; }, abstract = {Past studies in Serbia have reported concurrent infections of Ixodes ricinus ticks with Borrelia burgdorferi sensu lato genospecies, Anaplasma phagocytophilum and Francisella tularensis. As a step forward, this investigation included a broader range of microorganisms and five most common and abundant tick species in Serbia. Five tick species were identified (Dermacentor marginatus, D. reticulatus, Haemaphysalis punctata, H. concinna and I. ricinus) and analyzed for the presence of seven pathogens. Anaplasma ovis, A. phagocytophilum, Babesia canis, B. burgdorferi s.l., Coxiella burnetii, Rickettsia helvetica and R. monacensis were detected. Sequencing of samples positive for F. tularensis revealed the presence of Francisella-like endosymbionts. No Bartonella spp. DNA was amplified. Concurrent infections were present in three tick species (D. reticulatus, H. concinna and I. ricinus). The rate of co-infections was highest in I. ricinus (20/27), while this tick species harbored the broadest range of co-infection combinations, with dual, triple and a quadruple infection(s) being detected.}, }
@article {pmid22771735, year = {2012}, author = {Vianello, A and Casolo, V and Petrussa, E and Peresson, C and Patui, S and Bertolini, A and Passamonti, S and Braidot, E and Zancani, M}, title = {The mitochondrial permeability transition pore (PTP) - an example of multiple molecular exaptation?.}, journal = {Biochimica et biophysica acta}, volume = {1817}, number = {11}, pages = {2072-2086}, doi = {10.1016/j.bbabio.2012.06.620}, pmid = {22771735}, issn = {0006-3002}, mesh = {Animals ; Calcium/metabolism ; Evolution, Molecular ; Humans ; Mitochondrial Membrane Transport Proteins/genetics/*physiology ; Mitochondrial Permeability Transition Pore ; Phylogeny ; Potassium Channels/physiology ; Reactive Oxygen Species/metabolism ; }, abstract = {The mitochondrial permeability transition (PT) is a well-recognized phenomenon that allows mitochondria to undergo a sudden increase of permeability to solutes with molecular mass ≤ 1500Da, leading to organelle swelling and structural modifications. The relevance of PT relies on its master role in the manifestation of programmed cell death (PCD). This function is performed by a mega-channel (in some cases inhibited by cyclosporin A) named permeability transition pore (PTP), whose function could derive from the assembly of different mitochondrial proteins. In this paper we examine the distribution and characteristics of PTP in mitochondria of eukaryotic organisms so far investigated in order to draw a hypothesis on the mechanism of its evolution. As a result, we suggest that PTP may have arisen as a new function linked to a multiple molecular exaptation of different mitochondrial proteins, even though they could nevertheless still play their original role. Furthermore, we suggest that the early appearance of PTP could have had a crucial role in the establishment of endosymbiosis in eukaryotic cells, by the coordinated balancing of ATP production by glycolysis (performed by the primary phagocyte) and oxidative phosphorylation (accomplished by the endosymbiont). Indeed, we argue on the possibility that this new energetic equilibrium could have opened the way to the subsequent evolution toward metazoans.}, }
@article {pmid22771302, year = {2013}, author = {Login, FH and Heddi, A}, title = {Insect immune system maintains long-term resident bacteria through a local response.}, journal = {Journal of insect physiology}, volume = {59}, number = {2}, pages = {232-239}, doi = {10.1016/j.jinsphys.2012.06.015}, pmid = {22771302}, issn = {1879-1611}, mesh = {Animals ; Bacteria/classification/genetics ; *Bacterial Physiological Phenomena ; Bacterial Proteins/metabolism ; Evolution, Molecular ; Immunity, Innate ; Insect Proteins/metabolism ; Phylogeny ; RNA, Ribosomal, 16S/genetics/metabolism ; *Symbiosis ; Weevils/immunology/metabolism/*microbiology ; }, abstract = {Long-term associations between bacteria and animals are widely represented in nature and play an important role in animal adaptation and evolution. In insects thriving on nutritionally unbalanced diets, intracellular symbiotic bacteria (endosymbionts) complement the host nutrients with amino acids and vitamins and interfere with host physiology and reproduction. Endosymbionts permanently infect host cells, called bacteriocytes, which express an adapted local immune response that permits symbiont maintenance and control. Among the immune players in bacteriocytes, the coleoptericin A (ColA) antimicrobial peptide of the cereal weevil, Sitophilus zeamais, was recently found to specifically trigger endosymbionts and to inhibit their cytokinesis, thereby limiting bacterial cell division and dispersion throughout the insect tissues. This review focuses on the biological and evolutionary features of Sitophilus symbiosis, and discusses the possible interactions of ColA with weevil endosymbiont proteins and pathways.}, }
@article {pmid22750140, year = {2012}, author = {Saikia, S and Takemoto, D and Tapper, BA and Lane, GA and Fraser, K and Scott, B}, title = {Functional analysis of an indole-diterpene gene cluster for lolitrem B biosynthesis in the grass endosymbiont Epichloë festucae.}, journal = {FEBS letters}, volume = {586}, number = {16}, pages = {2563-2569}, doi = {10.1016/j.febslet.2012.06.035}, pmid = {22750140}, issn = {1873-3468}, mesh = {Chromatography, Liquid/methods ; Epichloe ; Gene Deletion ; *Gene Expression Regulation, Fungal ; Indole Alkaloids ; Indoles/*chemistry ; Mass Spectrometry/methods ; Models, Chemical ; Models, Genetic ; *Multigene Family ; Mycotoxins/*biosynthesis/chemistry ; Penicillium/metabolism ; Poaceae/*metabolism/microbiology ; Promoter Regions, Genetic ; Time Factors ; }, abstract = {Epichloë festucae Fl1 in association with Lolium perenne synthesizes a diverse range of indole-diterpene bioprotective metabolites, including lolitrem B, a potent tremorgen. The ltm genes responsible for the synthesis of these metabolites are organized in three clusters at a single sub-telomeric locus in the genome of E. festucae. Here we resolve the genetic basis for the remarkable indole-diterpene diversity observed in planta by analyzing products that accumulate in associations containing ltm deletion mutants of E. festucae and in cells of Penicillium paxilli containing copies of these genes under the control of a P. paxilli biosynthetic gene promoter. We propose a biosynthetic scheme to account for this metabolic diversity.}, }
@article {pmid22743047, year = {2012}, author = {Alberdi, MP and Dalby, MJ and Rodriguez-Andres, J and Fazakerley, JK and Kohl, A and Bell-Sakyi, L}, title = {Detection and identification of putative bacterial endosymbionts and endogenous viruses in tick cell lines.}, journal = {Ticks and tick-borne diseases}, volume = {3}, number = {3}, pages = {137-146}, pmid = {22743047}, issn = {1877-9603}, support = {088588//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Arachnid Vectors/*microbiology/virology ; Argasidae/*microbiology/ultrastructure/virology ; Bacteria/*genetics ; Base Sequence ; Cell Line ; DNA Primers/genetics ; DNA, Complementary/genetics ; Humans ; Ixodidae/*microbiology/ultrastructure/virology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA Viruses/*genetics/ultrastructure ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Viral/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; Virion/ultrastructure ; }, abstract = {As well as being vectors of many viral, bacterial, and protozoan pathogens of medical and veterinary importance, ticks harbour a variety of microorganisms which are not known to be pathogenic for vertebrate hosts. Continuous cell lines established from ixodid and argasid ticks could be infected with such endosymbiotic bacteria and endogenous viruses, but to date very few cell lines have been examined for their presence. DNA and RNA extracted from over 50 tick cell lines deposited in the Roslin Wellcome Trust Tick Cell Biobank (http://tickcells.roslin.ac.uk) were screened for presence of bacteria and RNA viruses, respectively. Sequencing of PCR products amplified using pan-16S rRNA primers revealed the presence of DNA sequences from bacterial endosymbionts in several cell lines derived from Amblyomma and Dermacentor spp. ticks. Identification to species level was attempted using Rickettsia- and Francisella-specific primers. Pan-Nairovirus primers amplified PCR products of uncertain specificity in cell lines derived from Rhipicephalus, Hyalomma, Ixodes, Carios, and Ornithodoros spp. ticks. Further characterisation attempted with primers specific for Crimean-Congo haemorrhagic fever virus segments confirmed the absence of this arbovirus in the cells. A set of pan-Flavivirus primers did not detect endogenous viruses in any of the cell lines. Transmission electron microscopy revealed the presence of endogenous reovirus-like viruses in many of the cell lines; only 4 of these lines gave positive results with primers specific for the tick Orbivirus St Croix River virus, indicating that there may be additional, as yet undescribed 'tick-only' viruses inhabiting tick cell lines.}, }
@article {pmid22739493, year = {2013}, author = {Hawlena, H and Rynkiewicz, E and Toh, E and Alfred, A and Durden, LA and Hastriter, MW and Nelson, DE and Rong, R and Munro, D and Dong, Q and Fuqua, C and Clay, K}, title = {The arthropod, but not the vertebrate host or its environment, dictates bacterial community composition of fleas and ticks.}, journal = {The ISME journal}, volume = {7}, number = {1}, pages = {221-223}, pmid = {22739493}, issn = {1751-7370}, support = {RC2 HG005806/HG/NHGRI NIH HHS/United States ; /HHMI/Howard Hughes Medical Institute/United States ; 1RC2HG005806-01/HG/NHGRI NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification/genetics ; DNA, Bacterial/genetics ; Environment ; Indiana ; RNA, Ribosomal, 16S/genetics ; Rodentia/*microbiology ; Siphonaptera/*microbiology ; Ticks/*microbiology ; }, abstract = {Bacterial community composition in blood-sucking arthropods can shift dramatically across time and space. We used 16S rRNA gene amplification and pyrosequencing to investigate the relative impact of vertebrate host-related, arthropod-related and environmental factors on bacterial community composition in fleas and ticks collected from rodents in southern Indiana (USA). Bacterial community composition was largely affected by arthropod identity, but not by the rodent host or environmental conditions. Specifically, the arthropod group (fleas vs ticks) determined the community composition of bacteria, where bacterial communities of ticks were less diverse and more dependent on arthropod traits--especially tick species and life stage--than bacterial communities of fleas. Our data suggest that both arthropod life histories and the presence of arthropod-specific endosymbionts may mask the effects of the vertebrate host and its environment.}, }
@article {pmid22732604, year = {2012}, author = {Chen, SJ and Lu, F and Cheng, JA and Jiang, MX and Way, MO}, title = {Identification and biological role of the endosymbionts Wolbachia in rice water weevil (Coleoptera: Curculionidae).}, journal = {Environmental entomology}, volume = {41}, number = {3}, pages = {469-477}, doi = {10.1603/EN11195}, pmid = {22732604}, issn = {1938-2936}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics ; China ; Female ; Molecular Sequence Data ; Multilocus Sequence Typing ; *Pest Control, Biological ; Phylogeny ; Polymerase Chain Reaction ; Reproduction/drug effects ; Tetracycline/pharmacology ; Texas ; Weevils/drug effects/*microbiology/physiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia spp. are obligate intracellular bacteria present in reproductive tissues of many arthropod species. Wolbachia infection status and roles in host reproduction were studied in the rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera, Curculionidae), an introduced species in China. We examined Wolbachia infection status in five populations in China where it reproduces parthenogenetically, and one native population in Southeast Texas, where it reproduces bisexually. All populations were infected by Wolbachia, and all specimens in each population were infected by Wolbachia of a single strain. Phylogenetic analyses based on multilocus sequence typing system indicated that Wolbachia in non-native L. oryzophilus weevils diverges evidently from those in native weevils. After treatments with tetracycline, parthenogenetic weevils reduced the fecundity significantly and eggs were not viable. Our results suggest that Wolbachia are necessary for oocyte production in L oryzophilus.}, }
@article {pmid22726644, year = {2012}, author = {Vaughan, JA and Tkach, VV and Greiman, SE}, title = {Neorickettsial endosymbionts of the digenea: diversity, transmission and distribution.}, journal = {Advances in parasitology}, volume = {79}, number = {}, pages = {253-297}, doi = {10.1016/B978-0-12-398457-9.00003-2}, pmid = {22726644}, issn = {2163-6079}, support = {R15AI092622/AI/NIAID NIH HHS/United States ; }, mesh = {Anaplasmataceae Infections/microbiology/transmission/veterinary ; Animals ; *Biodiversity ; Dogs ; Horses ; Humans ; Neorickettsia/classification/isolation &amp; purification/pathogenicity/*physiology ; Phylogeography ; Platyhelminths/*microbiology ; *Symbiosis ; }, abstract = {Digeneans are endoparasitic flatworms with complex life cycles and distinct life stages that parasitize different host species. Some digenean species harbour bacterial endosymbionts known as Neorickettsia (Order Rickettsiales, Family Anaplasmataceae). Neorickettsia occur in all life stages and are maintained by vertical transmission. Far from benign however, Neorickettsia may also be transmitted horizontally by digenean parasites to their vertebrate definitive hosts. Once inside, Neorickettsia can infect macrophages and other cell types. In some vertebrate species (e.g. dogs, horses and humans), neorickettsial infections cause severe disease. Taken from a mostly parasitological perspective, this article summarizes our current knowledge on the transmission ecology of neorickettsiae, both for pathogenic species and for neorickettsiae of unknown pathogenicity. In addition, we discuss the diversity, phylogeny and geographical distribution of neorickettsiae, as well as their possible evolutionary associations with various groups of digeneans. Our understanding of neorickettsiae is at an early stage and there are undoubtedly many more neorickettsial endosymbioses with digeneans waiting to be discovered. Because neorickettsiae can infect vertebrates, it is particularly important to examine digenean species that regularly infect humans. Rapid advances in molecular tools and their application towards bacterial identification bode well for our future progress in understanding the biology of Neorickettsia.}, }
@article {pmid22713107, year = {2012}, author = {Boucias, DG and Garcia-Maruniak, A and Cherry, R and Lu, H and Maruniak, JE and Lietze, VU}, title = {Detection and characterization of bacterial symbionts in the Heteropteran, Blissus insularis.}, journal = {FEMS microbiology ecology}, volume = {82}, number = {3}, pages = {629-641}, doi = {10.1111/j.1574-6941.2012.01433.x}, pmid = {22713107}, issn = {1574-6941}, mesh = {Animals ; Burkholderia/*classification/genetics/*isolation &amp; purification ; Florida ; Gastrointestinal Tract/microbiology ; Heteroptera/growth &amp; development/*microbiology ; In Situ Hybridization, Fluorescence ; Life Cycle Stages ; Phylogeny ; Real-Time Polymerase Chain Reaction ; }, abstract = {Dense populations of extracellular bacteria were detected in midgut crypts of the southern chinch bug, Blissus insularis Barber (Hemiptera: Blissidae). Examination by epifluorescent and transmission electron microscopy revealed that the bacteria covered the luminal surface of the crypts and filled the entire lumen. Attempts to culture the extracellular endosymbionts in various media failed. Sequencing and phylogenetic analyses of 16S rRNA gene clones obtained from insects of five Florida populations showed high nucleotide homology to either betaproteobacterial Burkholderia spp. (243 clones from five populations) or gammaproteobacterial Pseudomonas spp. (58 clones from one population). Using Burkholderia-specific primers, bacteria were detected in the egg, nymph, and adult stages. Fluorescent in situ hybridization with genus-specific oligonucleotide probes confirmed the localization of Burkholderia in the crypts. Quantitative real-time PCR showed that antibiotic treatments of nymphs significantly reduced the amount of Burkholderia 16S rRNA gene copies in chinch bugs sampled 11 days after the treatment. Furthermore, these treatments resulted in retarded development and high mortality of B. insularis, indicating a beneficial impact of Burkholderia on its host.}, }
@article {pmid22711641, year = {2012}, author = {Zhong, J}, title = {Coxiella-like endosymbionts.}, journal = {Advances in experimental medicine and biology}, volume = {984}, number = {}, pages = {365-379}, doi = {10.1007/978-94-007-4315-1_18}, pmid = {22711641}, issn = {0065-2598}, mesh = {Animals ; Coxiella/*classification/genetics ; Host-Pathogen Interactions ; Humans ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Ticks/genetics/*microbiology ; }, abstract = {In the past two decades, many Coxiella-like bacteria have been found in hard ticks and soft ticks as well as in vertebrate hosts. It is interesting to note that many ticks harbor Coxiella-like bacteria with high prevalence. Coxiella-like bacteria and virulent Coxiella burnetii have high homology to each other; they form a monophyletic clade based on 16S rRNA sequence data and subsequent phylogenetic tree analyses. In this chapter, methods of detection, phylogeny, prevalence and density, distribution in tick organs, transmission routes, bacteria-host interactions, and putative functions of the Coxiella-like bacteria are reviewed.}, }
@article {pmid22701642, year = {2012}, author = {Padilla-Gamiño, JL and Pochon, X and Bird, C and Concepcion, GT and Gates, RD}, title = {From parent to gamete: vertical transmission of Symbiodinium (Dinophyceae) ITS2 sequence assemblages in the reef building coral Montipora capitata.}, journal = {PloS one}, volume = {7}, number = {6}, pages = {e38440}, pmid = {22701642}, issn = {1932-6203}, mesh = {Analysis of Variance ; Animals ; Anthozoa/genetics/*microbiology ; Base Sequence ; Cloning, Molecular ; Coral Reefs ; Dinoflagellida/*genetics ; Genes, Protozoan/genetics ; *Genetic Variation ; Hawaii ; Inheritance Patterns/*genetics ; Molecular Sequence Data ; Ovum/chemistry ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Statistics, Nonparametric ; Symbiosis/*genetics ; }, abstract = {Parental effects are ubiquitous in nature and in many organisms play a particularly critical role in the transfer of symbionts across generations; however, their influence and relative importance in the marine environment has rarely been considered. Coral reefs are biologically diverse and productive marine ecosystems, whose success is framed by symbiosis between reef-building corals and unicellular dinoflagellates in the genus Symbiodinium. Many corals produce aposymbiotic larvae that are infected by Symbiodinium from the environment (horizontal transmission), which allows for the acquisition of new endosymbionts (different from their parents) each generation. In the remaining species, Symbiodinium are transmitted directly from parent to offspring via eggs (vertical transmission), a mechanism that perpetuates the relationship between some or all of the Symbiodinium diversity found in the parent through multiple generations. Here we examine vertical transmission in the Hawaiian coral Montipora capitata by comparing the Symbiodinium ITS2 sequence assemblages in parent colonies and the eggs they produce. Parental effects on sequence assemblages in eggs are explored in the context of the coral genotype, colony morphology, and the environment of parent colonies. Our results indicate that ITS2 sequence assemblages in eggs are generally similar to their parents, and patterns in parental assemblages are different, and reflect environmental conditions, but not colony morphology or coral genotype. We conclude that eggs released by parent colonies during mass spawning events are seeded with different ITS2 sequence assemblages, which encompass phylogenetic variability that may have profound implications for the development, settlement and survival of coral offspring.}, }
@article {pmid22700927, year = {2012}, author = {van der Heide, T and Govers, LL and de Fouw, J and Olff, H and van der Geest, M and van Katwijk, MM and Piersma, T and van de Koppel, J and Silliman, BR and Smolders, AJ and van Gils, JA}, title = {A three-stage symbiosis forms the foundation of seagrass ecosystems.}, journal = {Science (New York, N.Y.)}, volume = {336}, number = {6087}, pages = {1432-1434}, doi = {10.1126/science.1219973}, pmid = {22700927}, issn = {1095-9203}, mesh = {Animals ; Bacteria/growth &amp; development/*metabolism ; Biomass ; Bivalvia/metabolism/microbiology/*physiology ; Chemoautotrophic Growth ; *Ecosystem ; Geologic Sediments/chemistry ; Gills/microbiology ; Magnoliopsida/growth &amp; development/*physiology ; Oxidation-Reduction ; Oxygen/metabolism ; Plant Roots/metabolism ; *Seawater/chemistry ; Sulfides/analysis/metabolism ; *Symbiosis ; Zosteraceae/growth &amp; development/*physiology ; }, abstract = {Seagrasses evolved from terrestrial plants into marine foundation species around 100 million years ago. Their ecological success, however, remains a mystery because natural organic matter accumulation within the beds should result in toxic sediment sulfide levels. Using a meta-analysis, a field study, and a laboratory experiment, we reveal how an ancient three-stage symbiosis between seagrass, lucinid bivalves, and their sulfide-oxidizing gill bacteria reduces sulfide stress for seagrasses. We found that the bivalve-sulfide-oxidizer symbiosis reduced sulfide levels and enhanced seagrass production as measured in biomass. In turn, the bivalves and their endosymbionts profit from organic matter accumulation and radial oxygen release from the seagrass roots. These findings elucidate the long-term success of seagrasses in warm waters and offer new prospects for seagrass ecosystem conservation.}, }
@article {pmid22697166, year = {2012}, author = {Urban, JM and Cryan, JR}, title = {Two ancient bacterial endosymbionts have coevolved with the planthoppers (Insecta: Hemiptera: Fulgoroidea).}, journal = {BMC evolutionary biology}, volume = {12}, number = {}, pages = {87}, pmid = {22697166}, issn = {1471-2148}, mesh = {Animals ; Bayes Theorem ; Betaproteobacteria/classification/*genetics ; DNA, Bacterial/genetics ; *Evolution, Molecular ; Hemiptera/classification/*genetics/*microbiology ; Likelihood Functions ; Models, Genetic ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: Members of the hemipteran suborder Auchenorrhyncha (commonly known as planthoppers, tree- and leafhoppers, spittlebugs, and cicadas) are unusual among insects known to harbor endosymbiotic bacteria in that they are associated with diverse assemblages of bacterial endosymbionts. Early light microscopic surveys of species representing the two major lineages of Auchenorrhyncha (the planthopper superfamily Fulgoroidea; and Cicadomorpha, comprising Membracoidea [tree- and leafhoppers], Cercopoidea [spittlebugs], and Cicadoidea [cicadas]), found that most examined species harbored at least two morphologically distinct bacterial endosymbionts, and some harbored as many as six. Recent investigations using molecular techniques have identified multiple obligate bacterial endosymbionts in Cicadomorpha; however, much less is known about endosymbionts of Fulgoroidea. In this study, we present the initial findings of an ongoing PCR-based survey (sequencing 16S rDNA) of planthopper-associated bacteria to document endosymbionts with a long-term history of codiversification with their fulgoroid hosts.<br><br>RESULTS: Results of PCR surveys and phylogenetic analyses of 16S rDNA recovered a monophyletic clade of Betaproteobacteria associated with planthoppers; this clade included Vidania fulgoroideae, a recently described bacterium identified in exemplars of the planthopper family Cixiidae. We surveyed 77 planthopper species representing 18 fulgoroid families, and detected Vidania in 40 species (representing 13 families). Further, we detected the Sulcia endosymbiont (identified as an obligate endosymbiont of Auchenorrhyncha in previous studies) in 30 of the 40 species harboring Vidania. Concordance of the Vidania phylogeny with the phylogeny of the planthopper hosts (reconstructed based on sequence data from five genes generated from the same insect specimens from which the bacterial sequences were obtained) was supported by statistical tests of codiversification. Codiversification tests also supported concordance of the Sulcia phylogeny with the phylogeny of the planthopper hosts, as well as concordance of planthopper-associated Vidania and Sulcia phylogenies.<br><br>CONCLUSIONS: Our results indicate that the Betaproteobacterium Vidania is an ancient endosymbiont that infected the common ancestor of Fulgoroidea at least 130 million years ago. Comparison of our findings with the early light-microscopic surveys conducted by M&#xfc;ller suggests that Vidania is M&#xfc;ller's x-symbiont, which he hypothesized to have codiversified with most lineages of planthoppers and with the Sulcia endosymbiont.}, }
@article {pmid22690978, year = {2012}, author = {Ni, T and Yue, J and Sun, G and Zou, Y and Wen, J and Huang, J}, title = {Ancient gene transfer from algae to animals: mechanisms and evolutionary significance.}, journal = {BMC evolutionary biology}, volume = {12}, number = {}, pages = {83}, pmid = {22690978}, issn = {1471-2148}, mesh = {Animals ; Choanoflagellata/*genetics ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Multigene Family ; Phylogeny ; Plants/*genetics ; Plastids/genetics ; }, abstract = {BACKGROUND: Horizontal gene transfer (HGT) is traditionally considered to be rare in multicellular eukaryotes such as animals. Recently, many genes of miscellaneous algal origins were discovered in choanoflagellates. Considering that choanoflagellates are the existing closest relatives of animals, we speculated that ancient HGT might have occurred in the unicellular ancestor of animals and affected the long-term evolution of animals.<br><br>RESULTS: Through genome screening, phylogenetic and domain analyses, we identified 14 gene families, including 92 genes, in the tunicate Ciona intestinalis that are likely derived from miscellaneous photosynthetic eukaryotes. Almost all of these gene families are distributed in diverse animals, suggesting that they were mostly acquired by the common ancestor of animals. Their miscellaneous origins also suggest that these genes are not derived from a particular algal endosymbiont. In addition, most genes identified in our analyses are functionally related to molecule transport, cellular regulation and methylation signaling, suggesting that the acquisition of these genes might have facilitated the intercellular communication in the ancestral animal.<br><br>CONCLUSIONS: Our findings provide additional evidence that algal genes in aplastidic eukaryotes are not exclusively derived from historical plastids and thus important for interpreting the evolution of eukaryotic photosynthesis. Most importantly, our data represent the first evidence that more anciently acquired genes might exist in animals and that ancient HGT events have played an important role in animal evolution.}, }
@article {pmid22689638, year = {2012}, author = {Hansen, AK and Moran, NA}, title = {Altered tRNA characteristics and 3' maturation in bacterial symbionts with reduced genomes.}, journal = {Nucleic acids research}, volume = {40}, number = {16}, pages = {7870-7884}, pmid = {22689638}, issn = {1362-4962}, mesh = {Animals ; Aphids/microbiology ; Buchnera/*genetics ; Codon ; *Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; Nucleic Acid Conformation ; Protein Biosynthesis ; *RNA 3' End Processing ; RNA Editing ; RNA, Transfer/chemistry/*genetics/metabolism ; Symbiosis ; }, abstract = {Translational efficiency is controlled by tRNAs and other genome-encoded mechanisms. In organelles, translational processes are dramatically altered because of genome shrinkage and horizontal acquisition of gene products. The influence of genome reduction on translation in endosymbionts is largely unknown. Here, we investigate whether divergent lineages of Buchnera aphidicola, the reduced-genome bacterial endosymbiont of aphids, possess altered translational features compared with their free-living relative, Escherichia coli. Our RNAseq data support the hypothesis that translation is less optimal in Buchnera than in E. coli. We observed a specific, convergent, pattern of tRNA loss in Buchnera and other endosymbionts that have undergone genome shrinkage. Furthermore, many modified nucleoside pathways that are important for E. coli translation are lost in Buchnera. Additionally, Buchnera's A + T compositional bias has resulted in reduced tRNA thermostability, and may have altered aminoacyl-tRNA synthetase recognition sites. Buchnera tRNA genes are shorter than those of E. coli, as the majority no longer has a genome-encoded 3' CCA; however, all the expressed, shortened tRNAs undergo 3' CCA maturation. Moreover, expression of tRNA isoacceptors was not correlated with the usage of corresponding codons. Overall, our data suggest that endosymbiont genome evolution alters tRNA characteristics that are known to influence translational efficiency in their free-living relative.}, }
@article {pmid22689374, year = {2012}, author = {Kovacevic, G}, title = {Value of the Hydra model system for studying symbiosis.}, journal = {The International journal of developmental biology}, volume = {56}, number = {6-8}, pages = {627-635}, doi = {10.1387/ijdb.123510gk}, pmid = {22689374}, issn = {1696-3547}, mesh = {Animals ; Chlorella/*physiology ; Chlorophyta/physiology ; Hydra/anatomy &amp; histology/*physiology ; *Symbiosis ; }, abstract = {Green Hydra is used as a classical example for explaining symbiosis in schools as well as an excellent research model. Indeed the cosmopolitan green Hydra (Hydra viridissima) provides a potent experimental framework to investigate the symbiotic relationships between a complex eumetazoan organism and a unicellular photoautotrophic green algae named Chlorella. Chlorella populates a single somatic cell type, the gastrodermal myoepithelial cells (also named digestive cells) and the oocyte at the time of sexual reproduction. This symbiotic relationship is stable, well-determined and provides biological advantages to the algal symbionts, but also to green Hydra over the related non-symbiotic Hydra i.e. brown hydra. These advantages likely result from the bidirectional flow of metabolites between the host and the symbiont. Moreover genetic flow through horizontal gene transfer might also participate in the establishment of these selective advantages. However, these relationships between the host and the symbionts may be more complex. Thus, Jolley and Smith showed that the reproductive rate of the algae increases dramatically outside of Hydra cells, although this endosymbiont isolation is debated. Recently it became possible to keep different species of endosymbionts isolated from green Hydra in stable and permanent cultures and compare them to free-living Chlorella species. Future studies testing metabolic relationships and genetic flow should help elucidate the mechanisms that support the maintenance of symbiosis in a eumetazoan species.}, }
@article {pmid22689243, year = {2012}, author = {Rao, Q and Wang, S and Su, YL and Bing, XL and Liu, SS and Wang, XW}, title = {Draft genome sequence of "Candidatus Hamiltonella defensa," an endosymbiont of the whitefly Bemisia tabaci.}, journal = {Journal of bacteriology}, volume = {194}, number = {13}, pages = {3558}, pmid = {22689243}, issn = {1098-5530}, mesh = {Animals ; Bacterial Proteins/genetics ; Gammaproteobacteria/classification/*genetics/isolation &amp; purification/physiology ; Genome, Bacterial ; Hemiptera/*microbiology ; Molecular Sequence Data ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {"Candidatus Hamiltonella defensa" is a facultative endosymbiont of the whitefly Bemisia tabaci. Herein, we report the first draft genome sequence of "Candidatus Hamiltonella defensa" from the invasive Mediterranean cryptic species of the B. tabaci complex. The 1.84-Mbp genome sequence comprises 404 contigs and contains 1,806 predicted protein-coding genes.}, }
@article {pmid22685581, year = {2012}, author = {Zug, R and Hammerstein, P}, title = {Still a host of hosts for Wolbachia: analysis of recent data suggests that 40% of terrestrial arthropod species are infected.}, journal = {PloS one}, volume = {7}, number = {6}, pages = {e38544}, pmid = {22685581}, issn = {1932-6203}, mesh = {Algorithms ; Animals ; Arthropods/classification/*microbiology ; *Host Specificity ; Models, Statistical ; Species Specificity ; Wolbachia/*physiology ; }, abstract = {Wolbachia are intracellular bacteria that manipulate the reproduction of their arthropod hosts in remarkable ways. They are predominantly transmitted vertically from mother to offspring but also occasionally horizontally between species. In doing so, they infect a huge range of arthropod species worldwide. Recently, a statistical analysis estimated the infection frequency of Wolbachia among arthropod hosts to be 66%. At the same time, the authors of this analysis highlighted some weaknesses of the underlying data and concluded that in order to improve the estimate, a larger number of individuals per species should be assayed and species be chosen more randomly. Here we apply the statistical approach to a more appropriate data set from a recent survey that tested both a broad range of species and a sufficient number of individuals per species. Indeed, we find a substantially different infection frequency: We now estimate the proportion of Wolbachia-infected species to be around 40% which is lower than the previous estimate but still points to a surprisingly high number of arthropods harboring the bacteria. Notwithstanding this difference, we confirm the previous result that, within a given species, typically most or only a few individuals are infected. Moreover, we extend our analysis to include several reproductive parasites other than Wolbachia that were also screened for in the aforementioned empirical survey. For these symbionts we find a large variation in estimated infection frequencies and corroborate the finding that Wolbachia are the most abundant endosymbionts among arthropod species.}, }
@article {pmid22683810, year = {2012}, author = {Warnecke, T}, title = {Loss of the DnaK-DnaJ-GrpE chaperone system among the Aquificales.}, journal = {Molecular biology and evolution}, volume = {29}, number = {11}, pages = {3485-3495}, doi = {10.1093/molbev/mss152}, pmid = {22683810}, issn = {1537-1719}, mesh = {Adaptation, Physiological/genetics ; Bacteria/genetics ; Bacterial Proteins/*genetics ; Base Sequence ; Genome, Bacterial/genetics ; HSP40 Heat-Shock Proteins/*genetics ; HSP70 Heat-Shock Proteins/*genetics ; Homeostasis ; Open Reading Frames/genetics ; Phylogeny ; Protein Biosynthesis/genetics ; Solubility ; Temperature ; }, abstract = {The DnaK-DnaJ-GrpE (KJE) chaperone system functions at the fulcrum of protein homeostasis in bacteria. It interacts both with nascent polypeptides and with proteins that have become unfolded, either funneling its clients toward the native state or ushering misfolded proteins into degradation. In line with its key role in protein folding, KJE has been considered an essential building block for a minimal bacterial genome and common to all bacteria. In this study, I present a rigorous survey of 1,233 bacterial genomes, which reveals that the entire KJE system is uniquely absent from two members of the order Aquificales, Desulfurobacterium thermolithotrophum, and Thermovibrio ammonificans. The absence of KJE from these free-living bacteria is surprising, particularly in light of the finding that individual losses of grpE and dnaJ are restricted to obligate endosymbionts with highly reduced genomes, whereas dnaK has never been lost in isolation. Examining protein features diagnostic of DnaK substrates in Escherichia coli, radical changes in protein solubility emerge as a likely precondition for the loss of KJE. Both D. thermolithotrophum and T. ammonificans grow under strictly anaerobic conditions at temperatures in excess of 70°C, reminiscent of hyperthermophilic archaea, which--unlike their mesophilic cousins--also lack KJE. I suggest that high temperature promotes the evolution of high intrinsic protein solubility on a proteome-wide scale and thereby creates conditions under which KJE can be lost. However, the shift in solubility is common to all Aquificales and hence not sufficient to explain the restricted incidence of KJE loss.}, }
@article {pmid22677398, year = {2012}, author = {Yamauchi, A and Telschow, A}, title = {Bistability of endosymbiont evolution of genome size and host sex control.}, journal = {Journal of theoretical biology}, volume = {309}, number = {}, pages = {58-66}, doi = {10.1016/j.jtbi.2012.05.014}, pmid = {22677398}, issn = {1095-8541}, mesh = {Animals ; Computer Simulation ; *Evolution, Molecular ; Female ; Genome Size/*genetics ; Male ; Models, Biological ; *Sex Ratio ; Symbiosis/*genetics ; }, abstract = {Eukaryotic organisms often harbor several genetic factors in their cytoplasm. These cytoplasmic genetic elements (CGEs) include both eukaryotic organelles (mitochondria, chloroplasts) and bacterial endosymbionts, which have evolved from free-living bacteria. A common feature of CGEs is their cytoplasmic inheritance from mother to offspring. A striking difference is that some CGEs have evolved a short genome size (e.g., animal mitochondria), while others cause a sex ratio distortion (SRD) in their hosts (e.g., Wolbachia). In this study, we sought to resolve the evolution of these endosymbiont properties using a population genetics approach. Our model divides the endosymbiont genome into a functional part and a part that can cause SRD, and our results indicate that the cytoplasmic inheritance system at the initiation of symbiosis plays a key role in determining the evolutionary trajectory of CGEs. We show that in endosymbiotic evolution, two states can be bistable, depending on the parameters. The evolution of the cytoplasmic inheritance system from biparental to uniparental can result in hysteresis in the evolution of cytoplasmic symbionts.}, }
@article {pmid22675600, year = {2012}, author = {Meincke, L and Copeland, A and Lapidus, A and Lucas, S and Berry, KW and Del Rio, TG and Hammon, N and Dalin, E and Tice, H and Pitluck, S and Richardson, P and Bruce, D and Goodwin, L and Han, C and Tapia, R and Detter, JC and Schmutz, J and Brettin, T and Larimer, F and Land, M and Hauser, L and Kyrpides, NC and Ivanova, N and Göker, M and Woyke, T and Wu, QL and Pöckl, M and Hahn, MW and Klenk, HP}, title = {Complete genome sequence of Polynucleobacter necessarius subsp. asymbioticus type strain (QLW-P1DMWA-1(T)).}, journal = {Standards in genomic sciences}, volume = {6}, number = {1}, pages = {74-83}, pmid = {22675600}, issn = {1944-3277}, support = {P 19853/FWF_/Austrian Science Fund FWF/Austria ; }, abstract = {Polynucleobacter necessarius subsp. asymbioticus strain QLW-P1DMWA-1(T) is a planktonic freshwater bacterium affiliated with the family Burkholderiaceae (class Betaproteobacteria). This strain is of interest because it represents a subspecies with cosmopolitan and ubiquitous distribution in standing freshwater systems. The 16S-23S ITS genotype represented by the sequenced strain comprised on average more than 10% of bacterioplankton in its home habitat. While all strains of the subspecies P. necessarius asymbioticus are free-living freshwater bacteria, strains belonging to the only other subspecies, P. necessarius subsp. necessarius are obligate endosymbionts of the ciliate Euplotes aediculatus. The two subspecies of P. necessarius are the instances of two closely related subspecies that differ in their lifestyle (free-living vs. obligate endosymbiont), and they are the only members of the genus Polynucleobacter with completely sequenced genomes. Here we describe the features of P. necessarius subsp. asymbioticus, together with the complete genome sequence and annotation. The 2,159,490 bp long chromosome with a total of 2,088 protein-coding and 48 RNA genes is the first completed genome sequence of the genus Polynucleobacter to be published and was sequenced as part of the DOE Joint Genome Institute Community Sequencing Program 2006.}, }
@article {pmid22675185, year = {2012}, author = {Dimond, JL and Holzman, BJ and Bingham, BL}, title = {Thicker host tissues moderate light stress in a cnidarian endosymbiont.}, journal = {The Journal of experimental biology}, volume = {215}, number = {Pt 13}, pages = {2247-2254}, doi = {10.1242/jeb.067991}, pmid = {22675185}, issn = {1477-9145}, mesh = {*Acclimatization ; Animals ; Chlorophyll/analysis/metabolism ; Chlorophyta/*physiology ; Cnidaria/*anatomy &amp; histology/chemistry/*physiology ; Epidermis/anatomy &amp; histology/chemistry ; Light ; *Photosynthesis ; *Symbiosis ; }, abstract = {The susceptibility of algal-cnidarian holobionts to environmental stress is dependent on attributes of both host and symbiont, but the role of the host is often unclear. We examined the influence of the host on symbiont light stress, comparing the photophysiology of the chlorophyte symbiont Elliptochloris marina in two species of sea anemones in the genus Anthopleura. After 3 months of acclimation in outdoor tanks, polyp photoprotective contraction behavior was similar between the two host species, but photochemical efficiency was 1.5 times higher in A. xanthogrammica than in A. elegantissima. Maximum relative electron transport rates, derived from rapid light curves, were 1.5 times higher in A. xanthogrammica than in A. elegantissima when symbionts were inside intact tissues, but were not significantly different between host species upon removal of outer (epidermis and mesoglea) tissue layers from symbiont-containing gastrodermal cells. Tissues of A. xanthogrammica were 1.8 times thicker than those of A. elegantissima, with outer tissue layers attenuating 1.6 times more light. We found no significant differences in light absorption properties per unit volume of tissue, confirming the direct effect of tissue thickness on light attenuation. The thicker tissues of A. xanthogrammica thus provide a favorable environment for E. marina - a relatively stress-susceptible symbiont - and may explain its higher prevalence and expanded range in A. xanthogrammica along the Pacific coast of North America. Our findings also support a photoprotective role for thicker host tissues in reef corals that has long been thought to influence variability in bleaching susceptibility among coral taxa.}, }
@article {pmid22675165, year = {2012}, author = {Hancock, PA and Godfray, HC}, title = {Modelling the spread of Wolbachia in spatially heterogeneous environments.}, journal = {Journal of the Royal Society, Interface}, volume = {9}, number = {76}, pages = {3045-3054}, pmid = {22675165}, issn = {1742-5662}, support = {/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Age Factors ; Animals ; *Environment ; Host-Pathogen Interactions ; Insecta/*microbiology ; *Models, Biological ; Population Density ; Population Dynamics ; *Symbiosis ; Wolbachia/*growth &amp; development ; }, abstract = {The endosymbiont Wolbachia infects a large number of insect species and is capable of rapid spread when introduced into a novel host population. The bacteria spread by manipulating their hosts' reproduction, and their dynamics are influenced by the demographic structure of the host population and patterns of contact between individuals. Reaction-diffusion models of the spatial spread of Wolbachia provide a simple analytical description of their spatial dynamics but do not account for significant details of host population dynamics. We develop a metapopulation model describing the spatial dynamics of Wolbachia in an age-structured host insect population regulated by juvenile density-dependent competition. The model produces similar dynamics to the reaction-diffusion model in the limiting case where the host's habitat quality is spatially homogeneous and Wolbachia has a small effect on host fitness. When habitat quality varies spatially, Wolbachia spread is usually much slower, and the conditions necessary for local invasion are strongly affected by immigration of insects from surrounding regions. Spread is most difficult when variation in habitat quality is spatially correlated. The results show that spatial variation in the density-dependent competition experienced by juvenile host insects can strongly affect the spread of Wolbachia infections, which is important to the use of Wolbachia to control insect vectors of human disease and other pests.}, }
@article {pmid22674991, year = {2012}, author = {Shaw, AE and Veronesi, E and Maurin, G and Ftaich, N and Guiguen, F and Rixon, F and Ratinier, M and Mertens, P and Carpenter, S and Palmarini, M and Terzian, C and Arnaud, F}, title = {Drosophila melanogaster as a model organism for bluetongue virus replication and tropism.}, journal = {Journal of virology}, volume = {86}, number = {17}, pages = {9015-9024}, pmid = {22674991}, issn = {1098-5514}, support = {BBS/E/I/00001701/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; G0801822/MRC_/Medical Research Council/United Kingdom ; MC_U130115834/MRC_/Medical Research Council/United Kingdom ; MC_UU_12014/6/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Bluetongue/*virology ; Bluetongue virus/genetics/*physiology ; Cattle ; Cattle Diseases/*virology ; Cell Line ; Ceratopogonidae/virology ; *Disease Models, Animal ; Drosophila melanogaster/genetics/*virology ; Insect Vectors/virology ; *Viral Tropism ; *Virus Replication ; }, abstract = {Bluetongue virus (BTV) is the etiological agent of bluetongue (BT), a hemorrhagic disease of ruminants that can cause high levels of morbidity and mortality. BTV is an arbovirus transmitted between its ruminant hosts by Culicoides biting midges (Diptera: Ceratopogonidae). Recently, Europe has experienced some of the largest BT outbreaks ever recorded, including areas with no known history of the disease, leading to unprecedented economic and animal welfare issues. The current lack of genomic resources and genetic tools for Culicoides restricts any detailed study of the mechanisms involved in the virus-insect interactions. In contrast, the genome of the fruit fly (Drosophila melanogaster) has been successfully sequenced, and it is used extensively as a model of molecular pathways due to the existence of powerful genetic technology. In this study, D. melanogaster is investigated as a model for the replication and tropism of BTV. Using reverse genetics, a modified BTV-1 that expresses the fluorescent mCherry protein fused to the viral nonstructural protein NS3 (BTV-1/NS3mCherry) was generated. We demonstrate that BTV-1/NS3mCherry is not only replication competent as it retains many characteristics of the wild-type virus but also replicates efficiently in D. melanogaster after removal of the bacterial endosymbiont Wolbachia pipientis by antibiotic treatment. Furthermore, confocal microscopy shows that the tissue tropism of BTV-1/NS3mCherry in D. melanogaster resembles that described previously for BTV in Culicoides. Overall, the data presented in this study demonstrate the feasibility of using D. melanogaster as a genetic model to investigate BTV-insect interactions that cannot be otherwise addressed in vector species.}, }
@article {pmid22662125, year = {2012}, author = {Sprecher, BN and Gittings, ME and Ludwig, RA}, title = {Respiratory membrane endo-hydrogenase activity in the microaerophile Azorhizobium caulinodans is bidirectional.}, journal = {PloS one}, volume = {7}, number = {5}, pages = {e36744}, pmid = {22662125}, issn = {1932-6203}, mesh = {Azorhizobium caulinodans/*enzymology/growth &amp; development ; Electron Transport Complex I/metabolism ; Hydrogen/metabolism ; Hydrogenase/chemistry/*metabolism ; Oxidation-Reduction ; }, abstract = {BACKGROUND: The microaerophilic bacterium Azorhizobium caulinodans, when fixing N(2) both in pure cultures held at 20 µM dissolved O(2) tension and as endosymbiont of Sesbania rostrata legume nodules, employs a novel, respiratory-membrane endo-hydrogenase to oxidize and recycle endogenous H(2) produced by soluble Mo-dinitrogenase activity at the expense of O(2).<br><br>METHODS AND FINDINGS: From a bioinformatic analysis, this endo-hydrogenase is a core (6 subunit) version of (14 subunit) NADH:ubiquinone oxidoreductase (respiratory complex I). In pure A. caulinodans liquid cultures, when O(2) levels are lowered to <1 &#xb5;M dissolved O(2) tension (true microaerobic physiology), in vivo endo-hydrogenase activity reverses and continuously evolves H(2) at high rates. In essence, H(+) ions then supplement scarce O(2) as respiratory-membrane electron acceptor. Paradoxically, from thermodynamic considerations, such hydrogenic respiratory-membrane electron transfer need largely uncouple oxidative phosphorylation, required for growth of non-phototrophic aerobic bacteria, A. caulinodans included.<br><br>CONCLUSIONS: A. caulinodans in vivo endo-hydrogenase catalytic activity is bidirectional. To our knowledge, this study is the first demonstration of hydrogenic respiratory-membrane electron transfer among aerobic (non-fermentative) bacteria. When compared with O(2) tolerant hydrogenases in other organisms, A. caulinodans in vivo endo-hydrogenase mediated H(2) production rates (50,000 pmol 10(9)&#xb7;cells(-1) min(-1)) are at least one-thousandfold higher. Conceivably, A. caulinodans respiratory-membrane hydrogenesis might initiate H(2) crossfeeding among spatially organized bacterial populations whose individual cells adopt distinct metabolic states in response to variant O(2) availability. Such organized, physiologically heterogeneous cell populations might benefit from augmented energy transduction and growth rates of the populations, considered as a whole.}, }
@article {pmid22655039, year = {2012}, author = {Vahling-Armstrong, CM and Zhou, H and Benyon, L and Morgan, JK and Duan, Y}, title = {Two plant bacteria, S. meliloti and Ca. Liberibacter asiaticus, share functional znuABC homologues that encode for a high affinity zinc uptake system.}, journal = {PloS one}, volume = {7}, number = {5}, pages = {e37340}, pmid = {22655039}, issn = {1932-6203}, mesh = {ATP-Binding Cassette Transporters/chemistry/genetics/*metabolism ; Amino Acid Sequence ; Bacterial Proteins/chemistry/genetics/*metabolism ; Citrus/microbiology ; Edetic Acid/metabolism ; Escherichia coli/chemistry/genetics/growth &amp; development/metabolism ; Genes, Bacterial ; Molecular Sequence Data ; Multigene Family ; Plants/*microbiology ; Rhizobiaceae/chemistry/genetics/growth &amp; development/*metabolism ; Sequence Alignment ; Sinorhizobium meliloti/chemistry/genetics/growth &amp; development/*metabolism ; Zinc/*metabolism ; }, abstract = {The Znu system, encoded for by znuABC, can be found in multiple genera of bacteria and has been shown to be responsible for the import of zinc under low zinc conditions. Although this high-affinity uptake system is known to be important for both growth and/or pathogenesis in bacteria, it has not been functionally characterized in a plant-associated bacterium. A single homologue of this system has been identified in the plant endosymbiont, Sinorhizobium meliloti, while two homologous systems were found in the destructive citrus pathogen, Candidatus Liberibacter asiaticus. To understand the role of these protein homologues, a complementation assay was devised allowing the individual genes that comprise the system to be assayed independently for their ability to reinstate a partially-inactivated Znu system. Results from the assays have demonstrated that although all of the genes from S. meliloti were able to restore activity, only one of the two Ca. Liberibacter asiaticus encoded gene clusters contained genes that were able to functionally complement the system. Additional analysis of the gene clusters reveals that distinct modes of regulation may also exist between the Ca. Liberibacter asiaticus and S. meliloti import systems despite the intracellular-plant niche common to both of these bacteria.}, }
@article {pmid22651853, year = {2012}, author = {de Freitas-Junior, PR and Catta-Preta, CM and Andrade, Ida S and Cavalcanti, DP and de Souza, W and Einicker-Lamas, M and Motta, MC}, title = {Effects of miltefosine on the proliferation, ultrastructure, and phospholipid composition of Angomonas deanei, a trypanosomatid protozoan that harbors a symbiotic bacterium.}, journal = {FEMS microbiology letters}, volume = {333}, number = {2}, pages = {129-137}, doi = {10.1111/j.1574-6968.2012.02607.x}, pmid = {22651853}, issn = {1574-6968}, mesh = {Bacteria/drug effects/growth &amp; development ; Cell Membrane/drug effects/metabolism/ultrastructure ; Cell Wall/drug effects/metabolism ; Choline-Phosphate Cytidylyltransferase/metabolism ; Crithidia/*drug effects/metabolism/*microbiology/ultrastructure ; Microscopy, Electron, Transmission ; Mitochondria/drug effects/ultrastructure ; Phosphatidylcholines/biosynthesis ; Phosphorus Isotopes/metabolism ; Phosphorylcholine/*analogs &amp; derivatives/pharmacology ; *Symbiosis ; }, abstract = {Some trypanosomatids, such as Angomonas deanei formerly named as Crithidia deanei, present an obligatory intracellular bacterium, which maintains a mutualistic relationship with the host. Phosphatidylcholine (PC) is the major phospholipid in eukaryotes and an essential component of cell membranes playing structural, biochemical, and physiological roles. However, in prokaryotes, PC is present only in those species closely associated with eukaryotes, either in symbiotic or pathogenic interactions. In trypanosomatids, the endosymbiont envelope is composed by a reduced cell wall and by two membrane units that lack sterols and present cardiolipin (CL) and PC as the major phospholipids. In this study, we tested the effects of miltefosine in A. deanei proliferation, as well as, on the ultrastrucuture and phospholipid composition considering that this drug inhibits the CTP-phosphocholine cytidyltransferase (CCT), a key enzyme in the PC biosynthesis. Besides the low effect of miltefosine in cellular proliferation, treated protozoa presented ultrastructural alterations such as plasma membrane shedding and blebbing, mitochondrial swelling, and convolutions of the endosymbiont envelope. The use of (32) Pi as a tracer revealed that the production of PC, CL, and phosphatidylethanolamine decreased while phosphatidylinositol production remained stable. Mitochondrion and symbiont fractions obtained from protozoa treated with miltefosine also presented a decrease in phospholipid production, reinforcing the idea that an intensive metabolic exchange occurs between the host trypanosomatid and structures of symbiotic origin.}, }
@article {pmid22649020, year = {2012}, author = {Turba, ME and Zambon, E and Zannoni, A and Russo, S and Gentilini, F}, title = {Detection of Wolbachia DNA in blood for diagnosing filaria-associated syndromes in cats.}, journal = {Journal of clinical microbiology}, volume = {50}, number = {8}, pages = {2624-2630}, pmid = {22649020}, issn = {1098-660X}, mesh = {Animals ; Bacterial Proteins/genetics ; Blood/*microbiology ; Cat Diseases/*diagnosis ; Cats ; DNA, Bacterial/genetics/*isolation &amp; purification ; Dirofilaria immitis/*microbiology ; Filariasis/diagnosis/*veterinary ; Polymerase Chain Reaction/*methods ; Sensitivity and Specificity ; Veterinary Medicine/methods ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {A fundamental role for the endosymbiotic bacteria Wolbachia pipientis in the pathogenesis of Dirofilaria immitis infections has emerged in recent years. Diagnostic opportunities arising from this breakthrough have not yet been fully exploited. This study was aimed at developing conventional and real-time PCR assays to carry out a molecular survey in a convenience sample of cats living in an area where D. immitis is endemic and to evaluate the detection of bacterial DNA in blood as a surrogate assay for diagnosing filaria-associated syndromes in cats. COI and FtsZ loci were used as targets for D. immitis and Wolbachia PCR assays, respectively, and real-time TaqMan PCR assays were used only for Wolbachia. A convenience sample of 307 disease-affected or healthy cats examined at a University facility were PCR tested, and their medical records were investigated. Conventional nested PCR for Wolbachia amplified the endosymbionts of both D. immitis and D. repens, while real-time PCR was highly specific only for the former. Observed prevalences of 0.3 and 10.4% were found using conventional nested PCR assays for D. immitis and real-time PCR for Wolbachia, respectively. Similar prevalences were established using the Wolbachia nested PCR (98% concordance with real-time PCR). The group of Wolbachia-positive samples had a significantly higher proportion of subjects with respiratory signs (29.0% versus 9.7%; P = 0.002). The findings of this study indicate that a highly sensitive PCR assay can be used to detect the Wolbachia organism in the peripheral blood of cats with respiratory signs.}, }
@article {pmid22645068, year = {2012}, author = {Valdez Barillas, JR and Quinn, CF and Freeman, JL and Lindblom, SD and Fakra, SC and Marcus, MA and Gilligan, TM and Alford, &#xc9;R and Wangeline, AL and Pilon-Smits, EA}, title = {Selenium distribution and speciation in the hyperaccumulator Astragalus bisulcatus and associated ecological partners.}, journal = {Plant physiology}, volume = {159}, number = {4}, pages = {1834-1844}, pmid = {22645068}, issn = {1532-2548}, mesh = {Animals ; Astragalus Plant/*metabolism ; *Ecosystem ; Flowers/anatomy &amp; histology/metabolism ; Herbivory/physiology ; Larva/physiology ; Models, Biological ; Moths/physiology ; Organ Specificity ; Seeds/anatomy &amp; histology/metabolism ; Selenium/*metabolism ; Spectrometry, X-Ray Emission ; Sulfur/metabolism ; X-Ray Absorption Spectroscopy ; }, abstract = {The goal of this study was to investigate how plant selenium (Se) hyperaccumulation may affect ecological interactions and whether associated partners may affect Se hyperaccumulation. The Se hyperaccumulator Astragalus bisulcatus was collected in its natural seleniferous habitat, and x-ray fluorescence mapping and x-ray absorption near-edge structure spectroscopy were used to characterize Se distribution and speciation in all organs as well as in encountered microbial symbionts and herbivores. Se was present at high levels (704-4,661 mg kg(-1) dry weight) in all organs, mainly as organic C-Se-C compounds (i.e. Se bonded to two carbon atoms, e.g. methylselenocysteine). In nodule, root, and stem, up to 34% of Se was found as elemental Se, which was potentially due to microbial activity. In addition to a nitrogen-fixing symbiont, the plants harbored an endophytic fungus that produced elemental Se. Furthermore, two Se-resistant herbivorous moths were discovered on A. bisulcatus, one of which was parasitized by a wasp. Adult moths, larvae, and wasps all accumulated predominantly C-Se-C compounds. In conclusion, hyperaccumulators live in association with a variety of Se-resistant ecological partners. Among these partners, microbial endosymbionts may affect Se speciation in hyperaccumulators. Hyperaccumulators have been shown earlier to negatively affect Se-sensitive ecological partners while apparently offering a niche for Se-resistant partners. Through their positive and negative effects on different ecological partners, hyperaccumulators may influence species composition and Se cycling in seleniferous ecosystems.}, }
@article {pmid22639643, year = {2012}, author = {Chanroj, S and Wang, G and Venema, K and Zhang, MW and Delwiche, CF and Sze, H}, title = {Conserved and diversified gene families of monovalent cation/h(+) antiporters from algae to flowering plants.}, journal = {Frontiers in plant science}, volume = {3}, number = {}, pages = {25}, pmid = {22639643}, issn = {1664-462X}, abstract = {All organisms have evolved strategies to regulate ion and pH homeostasis in response to developmental and environmental cues. One strategy is mediated by monovalent cation-proton antiporters (CPA) that are classified in two superfamilies. Many CPA1 genes from bacteria, fungi, metazoa, and plants have been functionally characterized; though roles of plant CPA2 genes encoding K(+)-efflux antiporter (KEA) and cation/H(+) exchanger (CHX) families are largely unknown. Phylogenetic analysis showed that three clades of the CPA1 Na(+)-H(+) exchanger (NHX) family have been conserved from single-celled algae to Arabidopsis. These are (i) plasma membrane-bound SOS1/AtNHX7 that share ancestry with prokaryote NhaP, (ii) endosomal AtNHX5/6 that is part of the eukaryote Intracellular-NHE clade, and (iii) a vacuolar NHX clade (AtNHX1-4) specific to plants. Early diversification of KEA genes possibly from an ancestral cyanobacterium gene is suggested by three types seen in all plants. Intriguingly, CHX genes diversified from three to four members in one subclade of early land plants to 28 genes in eight subclades of Arabidopsis. Homologs from Spirogyra or Physcomitrella share high similarity with AtCHX20, suggesting that guard cell-specific AtCHX20 and its closest relatives are founders of the family, and pollen-expressed CHX genes appeared later in monocots and early eudicots. AtCHX proteins mediate K(+) transport and pH homeostasis, and have been localized to intracellular and plasma membrane. Thus KEA genes are conserved from green algae to angiosperms, and their presence in red algae and secondary endosymbionts suggest a role in plastids. In contrast, AtNHX1-4 subtype evolved in plant cells to handle ion homeostasis of vacuoles. The great diversity of CHX genes in land plants compared to metazoa, fungi, or algae would imply a significant role of ion and pH homeostasis at dynamic endomembranes in the vegetative and reproductive success of flowering plants.}, }
@article {pmid22624773, year = {2012}, author = {Priya, NG and Pandey, N and Rajagopal, R}, title = {LNA probes substantially improve the detection of bacterial endosymbionts in whole mount of insects by fluorescent in-situ hybridization.}, journal = {BMC microbiology}, volume = {12}, number = {}, pages = {81}, pmid = {22624773}, issn = {1471-2180}, mesh = {Animals ; Bacteriological Techniques/*methods ; Enterobacteriaceae/genetics/*isolation &amp; purification ; Halomonadaceae/genetics/*isolation &amp; purification ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence/*methods ; Male ; Oligonucleotide Probes/genetics ; *Oligonucleotides/genetics ; Sensitivity and Specificity ; }, abstract = {BACKGROUND: Detection of unculturable bacteria and their localization in the host, by fluorescent in-situ hybridization (FISH), is a powerful technique in the study of host-bacteria interaction. FISH probes are designed to target the 16 s rRNA region of the bacteria to be detected. LNA probes have recently been used in FISH studies and proven to be more efficient. To date no report has employed LNA probes for FISH detection of bacterial endosymbiont in the whole mount tissues. Further, though speculated, bacteriocytes have not been reported from males of Bemisia tabaci.<br><br>RESULTS: In this study, we compared the efficiency in detecting bacteria by fluorescent DNA oligonucleotides versus modified probes containing Locked Nucleic Acid (LNA) substitution in their structure. We used the insect Bemisia tabaci as the experimental material since it carried simultaneous infection by two bacteria: one a primary endosymbiont, Portiera (and present in more numbers) while the other a secondary endosymbiont Arsenophonus (and present in less numbers). Thus a variation in the abundance of bacteria was expected. While detecting both the bacteria, we found a significant increase in the signal whenever LNA probes were used. However, the difference was more pronounced in detecting the secondary endosymbiont, wherein DNA probes gave weak signals when compared to LNA probes. Also, signal to noise ratio for LNA probes was higher than DNA probes. We found that LNA considerably improved sensitivity of FISH, as compared to the commonly used DNA oligonucleotide probe.<br><br>CONCLUSION: By employing LNA probes we could detect endosymbiotic bacteria in males, which have never been reported previously. We were able to detect bacteriocytes containing Portiera and Arsenophonus in the males of B. tabaci. Thus, employing LNA probes at optimized conditions will help to significantly improve detection of bacteria at the lowest concentration and may give a comprehensible depiction about their specific distribution within samples.}, }
@article {pmid22620700, year = {2012}, author = {Crowder, CD and Matthews, HE and Rounds, MA and Li, F and Schutzer, SE and Sampath, R and Hofstadler, SA and Ecker, DJ and Eshoo, MW}, title = {Detection of heartworm infection in dogs via PCR amplification and electrospray ionization mass spectrometry of nucleic acid extracts from whole blood samples.}, journal = {American journal of veterinary research}, volume = {73}, number = {6}, pages = {854-859}, doi = {10.2460/ajvr.73.6.854}, pmid = {22620700}, issn = {1943-5681}, support = {2R44AI077156-02/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; DNA Primers/genetics ; DNA, Ribosomal/genetics ; Dirofilariasis/*diagnosis/genetics ; Dog Diseases/*diagnosis/genetics ; Dogs ; Mass Spectrometry/methods/veterinary ; Molecular Sequence Data ; Nucleic Acids/*blood ; Polymerase Chain Reaction/methods/veterinary ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Sequence Analysis, DNA/veterinary ; }, abstract = {OBJECTIVE: To develop and evaluate a rapid and accurate assay involving PCR amplification and electrospray ionization mass spectrometry of nucleic acid extracts from whole blood samples for the detection of Dirofilaria immitis infection in dogs.<br><br>SAMPLE: Whole blood nucleic acid extracts from 29 dogs experimentally infected with D immitis (and in which circulating D immitis antigen was detected) and 10 uninfected dogs.<br><br>PROCEDURES: 16 of the 29 whole blood samples from infected dogs were examined at the time of collection for circulating microfilaria. Nucleic acids were extracted from all whole blood specimens and underwent PCR amplification with 12 PCR primer pairs designed to detect a wide range of pathogens (including the Wolbachia endosymbiont of D immitis) and electrospray ionization mass spectrometry.<br><br>RESULTS: On the basis of assay results, heartworm infection was detected in 13 of 13 antigen-positive dogs of unknown microfilaria status, 11 of 11 antigen-positive dogs with circulating microfilaria, 0 of 3 antigen-positive dogs tested at 3 months after larval infection, 0 of 2 antigen-positive dogs with occult infections, and 0 of 10 uninfected dogs.<br><br>With the assay under investigation, it was possible to identify D immitis infection in dogs with circulating microfilaria via detection of the obligate Wolbachia endosymbiont of D immitis. It was not possible to identify dogs with occult infections, which suggested that circulating microfilaria must be present to detect infection with this assay, although further studies would be required to verify that finding.}, }
@article {pmid22617952, year = {2012}, author = {Qiu, H and Yang, EC and Bhattacharya, D and Yoon, HS}, title = {Ancient gene paralogy may mislead inference of plastid phylogeny.}, journal = {Molecular biology and evolution}, volume = {29}, number = {11}, pages = {3333-3343}, doi = {10.1093/molbev/mss137}, pmid = {22617952}, issn = {1537-1719}, mesh = {Cyanobacteria/*genetics ; Evolution, Molecular ; Gene Dosage/genetics ; Gene Silencing ; Genes, Chloroplast/*genetics ; Genome, Plastid/genetics ; Molecular Sequence Data ; Multigene Family/genetics ; Photosystem II Protein Complex/genetics ; *Phylogeny ; Plastids/*genetics ; *Sequence Homology, Nucleic Acid ; Time Factors ; }, abstract = {Because of its ancient origin more than 1 billion years ago, the highly reduced plastid genomes of Plantae (e.g., plant chloroplasts) provide limited insights into the initial stages of endosymbiont genome reduction. The photosynthetic amoeba Paulinella provides a more useful model to study this process because its alpha-cyanobacterium-derived plastid originated ∼60 Ma and the genome still contains ∼1,000 genes. Here, we compared and contrasted features associated with genome reduction due to primary endosymbiosis in Paulinella plastids and in marine, free-living strains of the picocyanobacterium, Prochlorococcus. Both types of genomes show gene inactivation, concerted evolution, and contraction of gene families that impact highly conserved single-copy phylogenetic markers in the plastid such as psbA, psbC, and psbD. Our data suggest that these photosystem II genes may provide misleading phylogenetic signal because each of the constituent Plantae lineages has likely undergone a different, independent series of events that led to their reduction to a single copy. This issue is most problematic for resolving basal Plantae relationships when differential plastid gene loss was presumably ongoing, as we observe in Paulinella species. Our work uncovers a key, previously unappreciated aspect of organelle genome reduction and demonstrates "work-in-progress" models such as Paulinella to be critical to gain a fuller understanding of algal and plant genome evolution.}, }
@article {pmid22615987, year = {2012}, author = {Alvarado, VY and Odokonyero, D and Duncan, O and Mirkov, TE and Scholthof, HB}, title = {Molecular and physiological properties associated with zebra complex disease in potatoes and its relation with Candidatus Liberibacter contents in psyllid vectors.}, journal = {PloS one}, volume = {7}, number = {5}, pages = {e37345}, pmid = {22615987}, issn = {1932-6203}, mesh = {Animals ; Carboxylic Ester Hydrolases/biosynthesis ; Catechol Oxidase/metabolism ; Cyclophilins/biosynthesis ; Hemiptera/*microbiology ; Insect Vectors/physiology ; Plant Diseases/*microbiology ; Plant Proteins/biosynthesis ; Plant Stems/metabolism ; Rhizobiaceae/*physiology ; Solanum tuberosum/*metabolism/microbiology ; Starch/metabolism ; }, abstract = {Zebra complex (ZC) disease on potatoes is associated with Candidatus Liberibacter solanacearum (CLs), an α-proteobacterium that resides in the plant phloem and is transmitted by the potato psyllid Bactericera cockerelli (Šulc). The name ZC originates from the brown striping in fried chips of infected tubers, but the whole plants also exhibit a variety of morphological features and symptoms for which the physiological or molecular basis are not understood. We determined that compared to healthy plants, stems of ZC-plants accumulate starch and more than three-fold total protein, including gene expression regulatory factors (e.g. cyclophilin) and tuber storage proteins (e.g., patatins), indicating that ZC-affected stems are reprogrammed to exhibit tuber-like physiological properties. Furthermore, the total phenolic content in ZC potato stems was elevated two-fold, and amounts of polyphenol oxidase enzyme were also high, both serving to explain the ZC-hallmark rapid brown discoloration of air-exposed damaged tissue. Newly developed quantitative and/or conventional PCR demonstrated that the percentage of psyllids in laboratory colonies containing detectable levels of CLs and its titer could fluctuate over time with effects on colony prolificacy, but presumed reproduction-associated primary endosymbiont levels remained stable. Potato plants exposed in the laboratory to psyllid populations with relatively low-CLs content survived while exposure of plants to high-CLs psyllids rapidly culminated in a lethal collapse. In conclusion, we identified plant physiological biomarkers associated with the presence of ZC and/or CLs in the vegetative potato plant tissue and determined that the titer of CLs in the psyllid population directly affects the rate of disease development in plants.}, }
@article {pmid22609369, year = {2012}, author = {Metcalf, JA and Bordenstein, SR}, title = {The complexity of virus systems: the case of endosymbionts.}, journal = {Current opinion in microbiology}, volume = {15}, number = {4}, pages = {546-552}, pmid = {22609369}, issn = {1879-0364}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; T32 GM007347/GM/NIGMS NIH HHS/United States ; T32 GM07347/GM/NIGMS NIH HHS/United States ; R01 GM085163-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Arthropods/microbiology ; Bacteriophages/*genetics/pathogenicity/physiology ; DNA, Viral/*genetics ; Evolution, Molecular ; Host-Pathogen Interactions ; *Symbiosis/genetics ; Wolbachia/*physiology/*virology ; }, abstract = {Host-microbe symbioses involving bacterial endosymbionts comprise some of the most intimate and long-lasting interactions on the planet. While restricted gene flow might be expected due to their intracellular lifestyle, many endosymbionts, especially those that switch hosts, are rampant with mobile DNA and bacteriophages. One endosymbiont, Wolbachia pipientis, infects a vast number of arthropod and nematode species and often has a significant portion of its genome dedicated to prophage sequences of a virus called WO. This phage has challenged fundamental theories of bacteriophage and endosymbiont evolution, namely the phage Modular Theory and bacterial genome stability in obligate intracellular species. WO has also opened up exciting windows into the tripartite interactions between viruses, bacteria, and eukaryotes.}, }
@article {pmid22593553, year = {2012}, author = {Burki, F and Flegontov, P and Oborník, M and Cihlár, J and Pain, A and Lukes, J and Keeling, PJ}, title = {Re-evaluating the green versus red signal in eukaryotes with secondary plastid of red algal origin.}, journal = {Genome biology and evolution}, volume = {4}, number = {6}, pages = {626-635}, pmid = {22593553}, issn = {1759-6653}, mesh = {Alveolata/*genetics/physiology ; Chlorophyta/classification/cytology/*genetics/physiology ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Phylogeny ; Plastids/*genetics ; Rhodophyta/classification/cytology/*genetics/physiology ; Symbiosis ; }, abstract = {The transition from endosymbiont to organelle in eukaryotic cells involves the transfer of significant numbers of genes to the host genomes, a process known as endosymbiotic gene transfer (EGT). In the case of plastid organelles, EGTs have been shown to leave a footprint in the nuclear genome that can be indicative of ancient photosynthetic activity in present-day plastid-lacking organisms, or even hint at the existence of cryptic plastids. Here, we evaluated the impact of EGT on eukaryote genomes by reanalyzing the recently published EST dataset for Chromera velia, an interesting test case of a photosynthetic alga closely related to apicomplexan parasites. Previously, 513 genes were reported to originate from red and green algae in a 1:1 ratio. In contrast, by manually inspecting newly generated trees indicating putative algal ancestry, we recovered only 51 genes congruent with EGT, of which 23 and 9 were of red and green algal origin, respectively, whereas 19 were ambiguous regarding the algal provenance. Our approach also uncovered 109 genes that branched within a monocot angiosperm clade, most likely representing a contamination. We emphasize the lack of congruence and the subjectivity resulting from independent phylogenomic screens for EGT, which appear to call for extreme caution when drawing conclusions for major evolutionary events.}, }
@article {pmid22591396, year = {2012}, author = {Stefanini, A and Duron, O}, title = {Exploring the effect of the Cardinium endosymbiont on spiders.}, journal = {Journal of evolutionary biology}, volume = {25}, number = {8}, pages = {1521-1530}, doi = {10.1111/j.1420-9101.2012.02535.x}, pmid = {22591396}, issn = {1420-9101}, mesh = {Animals ; Bacteroidetes/*physiology ; Biological Evolution ; Cytoplasm/microbiology ; DNA, Mitochondrial/genetics ; Female ; Genetic Variation ; Male ; Ovum/microbiology ; Reproduction ; Spiders/*genetics/*microbiology ; Symbiosis/*genetics ; }, abstract = {Spiders have recently emerged as important diversity hot spots for endosymbiotic bacteria, but the consequences of these symbiotic interactions are largely unknown. In this article, we examined the evolutionary history and effect of the intracellular bacterium Cardinium hertigii in the marbled cellar spider Holocnemus pluchei. We showed that Cardinium infection is primarily transmitted in spider populations maternally via egg cytoplasm, with 100% of the progeny from infected mothers being also infected. Examination of a co-inherited marker, mitochondrial DNA (mtDNA), revealed that Cardinium infection is associated with a wide diversity of mtDNA haplotypes, showing that the interaction between Cardinium and H. pluchei has a long-term evolutionary dimension and that horizontal transmission among individuals could also occur. Although Cardinium is well known to exert sex ratio distortion or cytoplasmic incompatibility in various arthropod hosts, we show, however, that Cardinium does not interact with the reproductive biology of H. pluchei. A field survey shows a clear geographical structuring of Cardinium infection, with a marked gradual variation of infection frequencies from ca. 0.80 to 0. We discuss different mechanistic and evolutionary explanations for these results as well as their consequences for spider phenotypes. Notably, we suggest that Cardinium can either behave as a neutral cytoplasmic element within H. pluchei or exhibit a context-dependent effect, depending on the environmental conditions.}, }
@article {pmid22583543, year = {2012}, author = {Kumar, N and Creasy, T and Sun, Y and Flowers, M and Tallon, LJ and Dunning Hotopp, JC}, title = {Efficient subtraction of insect rRNA prior to transcriptome analysis of Wolbachia-Drosophila lateral gene transfer.}, journal = {BMC research notes}, volume = {5}, number = {}, pages = {230}, pmid = {22583543}, issn = {1756-0500}, mesh = {Actins/genetics ; Animals ; Drosophila/*genetics/*microbiology ; Gene Expression Profiling/*methods ; Gene Transfer, Horizontal/*genetics ; Genes, Insect/genetics ; RNA, Messenger/genetics/metabolism ; RNA, Ribosomal, 18S/genetics/*isolation &amp; purification ; Wolbachia/*genetics ; }, abstract = {BACKGROUND: Numerous methods exist for enriching bacterial or mammalian mRNA prior to transcriptome experiments. Yet there persists a need for methods to enrich for mRNA in non-mammalian animal systems. For example, insects contain many important and interesting obligate intracellular bacteria, including endosymbionts and vector-borne pathogens. Such obligate intracellular bacteria are difficult to study by traditional methods. Therefore, genomics has greatly increased our understanding of these bacteria. Efficient subtraction methods are needed for removing both bacteria and insect rRNA in these systems to enable transcriptome-based studies.<br><br>FINDINGS: A method is described that efficiently removes >95% of insect rRNA from total RNA samples, as determined by microfluidics and transcriptome sequencing. This subtraction yielded a 6.2-fold increase in mRNA abundance. Such a host rRNA-depletion strategy, in combination with bacterial rRNA depletion, is necessary to analyze transcription of obligate intracellular bacteria. Here, transcripts were identified that arise from a lateral gene transfer of an entire Wolbachia bacterial genome into a Drosophila ananassae chromosome. In this case, an rRNA depletion strategy is preferred over polyA-based enrichment since transcripts arising from bacteria-to-animal lateral gene transfer may not be poly-adenylated.<br><br>CONCLUSIONS: This enrichment method yields a significant increase in mRNA abundance when poly-A selection is not suitable. It can be used in combination with bacterial rRNA subtraction to enable experiments to simultaneously measure bacteria and insect mRNA in vector and endosymbiont biology experiments.}, }
@article {pmid22575682, year = {2013}, author = {Raturi, A and Simmen, T}, title = {Where the endoplasmic reticulum and the mitochondrion tie the knot: the mitochondria-associated membrane (MAM).}, journal = {Biochimica et biophysica acta}, volume = {1833}, number = {1}, pages = {213-224}, doi = {10.1016/j.bbamcr.2012.04.013}, pmid = {22575682}, issn = {0006-3002}, mesh = {Animals ; Calcium Signaling/physiology ; Calcium-Binding Proteins/metabolism/physiology ; Cell Membrane/metabolism/*physiology ; Endoplasmic Reticulum/metabolism/*physiology ; Humans ; Lipid Metabolism/physiology ; Male ; Membrane Proteins/metabolism/physiology ; Mitochondria/metabolism/*physiology/ultrastructure ; Mitochondrial Dynamics/*physiology ; Mitochondrial Membranes/metabolism/*physiology ; Models, Biological ; }, abstract = {More than a billion years ago, bacterial precursors of mitochondria became endosymbionts in what we call eukaryotic cells today. The true significance of the word "endosymbiont" has only become clear to cell biologists with the discovery that the endoplasmic reticulum (ER) superorganelle dedicates a special domain for the metabolic interaction with mitochondria. This domain, identified in all eukaryotic cell systems from yeast to man and called the mitochondria-associated membrane (MAM), has a distinct proteome, specific tethers on the cytosolic face and regulatory proteins in the ER lumen of the ER. The MAM has distinct biochemical properties and appears as ER tubules closely apposed to mitochondria on electron micrographs. The functions of the MAM range from lipid metabolism and calcium signaling to inflammasome formation. Consistent with these functions, the MAM is enriched in lipid metabolism enzymes and calcium handling proteins. During cellular stress situations, like an altered cellular redox state, the MAM alters its set of regulatory proteins and thus alters MAM functions. Notably, this set prominently comprises ER chaperones and oxidoreductases that connect protein synthesis and folding inside the ER to mitochondrial metabolism. Moreover, ER membranes associated with mitochondria also accommodate parts of the machinery that determines mitochondrial membrane dynamics and connect mitochondria to the cytoskeleton. Together, these exciting findings demonstrate that the physiological interactions between the ER and mitochondria are so bilateral that we are tempted to compare their relationship to the one of a married couple: distinct, but inseparable and certainly dependent on each other. In this paradigm, the MAM stands for the intracellular location where the two organelles tie the knot. Resembling "real life", the happy marriage between the two organelles prevents the onset of diseases that are characterized by disrupted metabolism and decreased lifespan, including neurodegeneration and cancer. This article is part of a Special Issue entitled: Mitochondrial dynamics and physiology.}, }
@article {pmid22575468, year = {2012}, author = {Bodył, A and Mackiewicz, P and Gagat, P}, title = {Organelle evolution: Paulinella breaks a paradigm.}, journal = {Current biology : CB}, volume = {22}, number = {9}, pages = {R304-6}, doi = {10.1016/j.cub.2012.03.020}, pmid = {22575468}, issn = {1879-0445}, mesh = {*Biological Evolution ; Cercozoa/*physiology ; *Organelles ; Symbiosis ; }, abstract = {It is commonly assumed that transformations of endosymbionts into organelles are exceptionally rare evolutionary events because of hypothetical difficulties in the origin of an import apparatus for nuclear-encoded, organelle-targeted proteins along with their targeting signals. A challenge to this view comes from recent studies of protein import into the cyanobacterial endosymbionts/organelles of Paulinella chromatophora.}, }
@article {pmid22567162, year = {2012}, author = {Smith, MA and Bertrand, C and Crosby, K and Eveleigh, ES and Fernandez-Triana, J and Fisher, BL and Gibbs, J and Hajibabaei, M and Hallwachs, W and Hind, K and Hrcek, J and Huang, DW and Janda, M and Janzen, DH and Li, Y and Miller, SE and Packer, L and Quicke, D and Ratnasingham, S and Rodriguez, J and Rougerie, R and Shaw, MR and Sheffield, C and Stahlhut, JK and Steinke, D and Whitfield, J and Wood, M and Zhou, X}, title = {Wolbachia and DNA barcoding insects: patterns, potential, and problems.}, journal = {PloS one}, volume = {7}, number = {5}, pages = {e36514}, pmid = {22567162}, issn = {1932-6203}, mesh = {Animals ; DNA Barcoding, Taxonomic/*methods ; DNA, Mitochondrial/genetics ; Insecta/classification/*genetics/*microbiology ; Phylogeny ; Wolbachia/*genetics ; }, abstract = {Wolbachia is a genus of bacterial endosymbionts that impacts the breeding systems of their hosts. Wolbachia can confuse the patterns of mitochondrial variation, including DNA barcodes, because it influences the pathways through which mitochondria are inherited. We examined the extent to which these endosymbionts are detected in routine DNA barcoding, assessed their impact upon the insect sequence divergence and identification accuracy, and considered the variation present in Wolbachia COI. Using both standard PCR assays (Wolbachia surface coding protein--wsp), and bacterial COI fragments we found evidence of Wolbachia in insect total genomic extracts created for DNA barcoding library construction. When >2 million insect COI trace files were examined on the Barcode of Life Datasystem (BOLD) Wolbachia COI was present in 0.16% of the cases. It is possible to generate Wolbachia COI using standard insect primers; however, that amplicon was never confused with the COI of the host. Wolbachia alleles recovered were predominantly Supergroup A and were broadly distributed geographically and phylogenetically. We conclude that the presence of the Wolbachia DNA in total genomic extracts made from insects is unlikely to compromise the accuracy of the DNA barcode library; in fact, the ability to query this DNA library (the database and the extracts) for endosymbionts is one of the ancillary benefits of such a large scale endeavor--which we provide several examples. It is our conclusion that regular assays for Wolbachia presence and type can, and should, be adopted by large scale insect barcoding initiatives. While COI is one of the five multi-locus sequence typing (MLST) genes used for categorizing Wolbachia, there is limited overlap with the eukaryotic DNA barcode region.}, }
@article {pmid22562106, year = {2012}, author = {Ventura, IM and Martins, AB and Lyra, ML and Andrade, CA and Carvalho, KA and Klaczko, LB}, title = {Spiroplasma in Drosophila melanogaster populations: prevalence, male-killing, molecular identification, and no association with Wolbachia.}, journal = {Microbial ecology}, volume = {64}, number = {3}, pages = {794-801}, pmid = {22562106}, issn = {1432-184X}, mesh = {Animals ; Brazil ; DNA, Bacterial/genetics/isolation &amp; purification ; Drosophila melanogaster/*microbiology ; Female ; Male ; Phylogeny ; Polymerase Chain Reaction ; Prevalence ; Sex Factors ; Sex Ratio ; Species Specificity ; Spiroplasma/classification/*genetics/isolation &amp; purification/*physiology ; Symbiosis ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {Spiroplasma endosymbionts are maternally transmitted bacteria that may kill infected sons resulting in the production of female-biased broods. The prevalence of male killers varies considerably both between and within species. Here, we evaluate the spatial and temporal status of male-killing and non-male-killing Spiroplasma infection in three Brazilian populations of Drosophila melanogaster, nearly a decade after the first occurrence report for this species. The incidence of the male-killing Spiroplasma ranged from close to 0 to 17.7 % (so far the highest estimate for a Drosophila species) with a suggestion of temporal decline in a population. We also found non-male-killing Spiroplasma coexisting in one population at lower prevalence (3-5 %), and we did not detect it in the other two. This may be taken as a suggestion of a spreading advantage conferred by the male-killing strategy. Sequencing two loci, we identified the phylogenetic position of Spiroplasma strains from the three localities, showing that all strains group closely in the poulsonii clade. Due to intensive sampling effort, we were able to test the association between Spiroplasma infections and another widespread endosymbiont, Wolbachia, whose prevalence ranged from 81.8 to 100 %. The prevalence of Wolbachia did not differ between Spiroplasma-infected and uninfected strains in our largest sample nor were the prevalences of the two endosymbionts associated across localities.}, }
@article {pmid22558418, year = {2012}, author = {Hughes, GL and Pike, AD and Xue, P and Rasgon, JL}, title = {Invasion of Wolbachia into Anopheles and other insect germlines in an ex vivo organ culture system.}, journal = {PloS one}, volume = {7}, number = {4}, pages = {e36277}, pmid = {22558418}, issn = {1932-6203}, support = {R21 AI070178/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anopheles/*microbiology ; Female ; Host-Pathogen Interactions ; Male ; Organ Culture Techniques/*methods ; Ovary/*microbiology ; Pest Control, Biological/*methods ; Species Specificity ; Testis/*microbiology ; Time Factors ; Wolbachia/*physiology ; }, abstract = {The common bacterial endosymbiont Wolbachia manipulates its host's reproduction to promote its own maternal transmission, and can interfere with pathogen development in many insects making it an attractive agent for the control of arthropod-borne disease. However, many important species, including Anopheles mosquitoes, are uninfected. Wolbachia can be artificially transferred between insects in the laboratory but this can be a laborious and sometimes fruitless process. We used a simple ex vivo culturing technique to assess the suitability of Wolbachia-host germline associations. Wolbachia infects the dissected germline tissue of multiple insect species when the host tissue and bacteria are cultured together. Ovary and testis infection occurs in a density-dependent manner. Wolbachia strains are more capable of invading the germline of their native or closely related rather than divergent hosts. The ability of Wolbachia to associate with the germline of novel hosts is crucial for the development of stably-transinfected insect lines. Rapid assessment of the suitability of a strain-host combination prior to transinfection may dictate use of a particular Wolbachia strain. Furthermore, the cultured germline tissues of two major Anopheline vectors of Plasmodium parasites are susceptible to Wolbachia infection. This finding further enhances the prospect of using Wolbachia for the biological control of malaria.}, }
@article {pmid22558289, year = {2012}, author = {Huusgaard, RS and Vismann, B and Kühl, M and Macnaugton, M and Colmander, V and Rouse, GW and Glover, AG and Dahlgren, T and Worsaae, K}, title = {The potent respiratory system of Osedax mucofloris (Siboglinidae, Annelida)--a prerequisite for the origin of bone-eating Osedax?.}, journal = {PloS one}, volume = {7}, number = {4}, pages = {e35975}, pmid = {22558289}, issn = {1932-6203}, mesh = {Animals ; Annelida/*anatomy &amp; histology ; Bacteria/metabolism ; *Biological Evolution ; Biosensing Techniques ; Blood Vessels/anatomy &amp; histology ; Body Weight/physiology ; Bone and Bones/*physiology ; Epidermis/anatomy &amp; histology/physiology ; Feeding Behavior/*physiology ; Female ; Microscopy, Confocal ; Oxygen/metabolism ; Oxygen Consumption/physiology ; Respiratory System/*anatomy &amp; histology/cytology ; Staining and Labeling ; }, abstract = {Members of the conspicuous bone-eating genus, Osedax, are widely distributed on whale falls in the Pacific and Atlantic Oceans. These gutless annelids contain endosymbiotic heterotrophic bacteria in a branching root system embedded in the bones of vertebrates, whereas a trunk and anterior palps extend into the surrounding water. The unique life style within a bone environment is challenged by the high bacterial activity on, and within, the bone matrix possibly causing O(2) depletion, and build-up of potentially toxic sulphide. We measured the O(2) distribution around embedded Osedax and showed that the bone microenvironment is anoxic. Morphological studies showed that ventilation mechanisms in Osedax are restricted to the anterior palps, which are optimized for high O(2) uptake by possessing a large surface area, large surface to volume ratio, and short diffusion distances. The blood vascular system comprises large vessels in the trunk, which facilitate an ample supply of oxygenated blood from the anterior crown to a highly vascularised root structure. Respirometry studies of O. mucofloris showed a high O(2) consumption that exceeded the average O(2) consumption of a broad line of resting annelids without endosymbionts. We regard this combination of features of the respiratory system of O. mucofloris as an adaptation to their unique nutrition strategy with roots embedded in anoxic bones and elevated O(2) demand due to aerobic heterotrophic endosymbionts.}, }
@article {pmid22542641, year = {2012}, author = {Sugio, A and Hogenhout, SA}, title = {The genome biology of phytoplasma: modulators of plants and insects.}, journal = {Current opinion in microbiology}, volume = {15}, number = {3}, pages = {247-254}, doi = {10.1016/j.mib.2012.04.002}, pmid = {22542641}, issn = {1879-0364}, support = {BB/G001928/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BBS/E/J/000C0623/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; *Genome, Bacterial ; Host-Pathogen Interactions ; Insecta/*microbiology ; Phytoplasma/*genetics ; Plant Diseases/microbiology ; Plants/*microbiology ; }, abstract = {Phytoplasmas are bacterial pathogens of plants that are transmitted by insects. These bacteria uniquely multiply intracellularly in both plants (Plantae) and insects (Animalia). Similarly to bacterial endosymbionts, phytoplasmas have reduced genomes with limited metabolic capabilities. Nonetheless, the chromosomes of many phytoplasmas are rich in repeated DNA consisting of mobile elements. Phytoplasmas produce an arsenal of effectors most of which are encoded on these mobile elements and on plasmids. These effectors target conserved plant transcription factors resulting in witches' broom and leafy flower symptoms and suppression of plant defense to insect vectors that transmit the phytoplasmas. Future studies of these fascinating microbes will generate a wealth of new knowledge about forces that shape genomes and microbial interactions with multicellular hosts.}, }
@article {pmid22540028, year = {2012}, author = {Zeh, JA and Bonilla, MM and Adrian, AJ and Mesfin, S and Zeh, DW}, title = {From father to son: transgenerational effect of tetracycline on sperm viability.}, journal = {Scientific reports}, volume = {2}, number = {}, pages = {375}, pmid = {22540028}, issn = {2045-2322}, mesh = {Animals ; *Arachnida ; *Intergenerational Relations ; Male ; *Paternal Exposure ; Sperm Count ; Spermatozoa/*drug effects ; Tetracycline/*adverse effects ; }, abstract = {The broad-spectrum antibiotic tetracycline is used in animal production, antimicrobial therapy, and for curing arthropods infected with bacterial endosymbionts such as Wolbachia. Tetracycline inhibits mitochondrial translation, and recent evidence indicates that male reproductive traits may be particularly sensitive to this antibiotic. Here, we report the first multi-generation investigation of tetracycline's effects on ejaculate traits. In a study of the pseudoscorpion, Cordylochernes scorpioides, in which siblings were randomly assigned to control and tetracycline treatments across replicate full-sibling families, tetracycline did not affect body size in either sex, female reproduction or sperm number. However, tetracycline-treated males exhibited significantly reduced sperm viability compared to control males, and transmitted this toxic effect of tetracycline on sperm to their untreated sons but not to their F2 grandsons. These results are consistent with tetracycline-induced epigenetic changes in the male germline, and suggest the need for further investigation of transgenerational effects of tetracycline on male reproductive function.}, }
@article {pmid22539959, year = {2012}, author = {Casteel, CL and Hansen, AK and Walling, LL and Paine, TD}, title = {Manipulation of plant defense responses by the tomato psyllid (Bactericerca cockerelli) and its associated endosymbiont Candidatus Liberibacter psyllaurous.}, journal = {PloS one}, volume = {7}, number = {4}, pages = {e35191}, pmid = {22539959}, issn = {1932-6203}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Cyclopentanes/pharmacology ; Female ; Hemiptera/*microbiology ; Host-Pathogen Interactions ; Insect Vectors/microbiology ; Lycopersicon esculentum/enzymology/*metabolism ; Male ; Oxylipins/pharmacology ; Plant Diseases/microbiology ; Rhizobiaceae/drug effects/*physiology ; Salicylic Acid/pharmacology ; Signal Transduction ; Symbiosis ; }, abstract = {Some plant pathogens form obligate relationships with their insect vector and are vertically transmitted via eggs analogous to insect endosymbionts. Whether insect endosymbionts manipulate plant defenses to benefit their insect host remains unclear. The tomato psyllid, Bactericerca cockerelli (Sulc), vectors the endosymbiont "Candidatus Liberibacter psyllaurous" (Lps) during feeding on tomato (Solanum lycopersicum L.). Lps titer in psyllids varied relative to the psyllid developmental stage with younger psyllids harboring smaller Lps populations compared to older psyllids. In the present study, feeding by different life stages of B. cockerelli infected with Lps, resulted in distinct tomato transcript profiles. Feeding by young psyllid nymphs, with lower Lps levels, induced tomato genes regulated by jasmonic acid (JA) and salicylic acid (SA) (Allene oxide synthase, Proteinase inhibitor 2, Phenylalanine ammonia-lyase 5, Pathogenesis-related protein 1) compared to feeding by older nymphs and adults, where higher Lps titers were found. In addition, inoculation of Lps without insect hosts suppressed accumulation of these defense transcripts. Collectively, these data suggest that the endosymbiont-like pathogen Lps manipulates plant signaling and defensive responses to benefit themselves and the success of their obligate insect vector on their host plant.}, }
@article {pmid22537833, year = {2013}, author = {Balmand, S and Lohs, C and Aksoy, S and Heddi, A}, title = {Tissue distribution and transmission routes for the tsetse fly endosymbionts.}, journal = {Journal of invertebrate pathology}, volume = {112 Suppl}, number = {0}, pages = {S116-22}, pmid = {22537833}, issn = {1096-0805}, support = {R01 AI081774/AI/NIAID NIH HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; AI06892/AI/NIAID NIH HHS/United States ; GM069449/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Enterobacteriaceae ; In Situ Hybridization, Fluorescence ; *Symbiosis ; Tsetse Flies/*microbiology ; *Wigglesworthia ; *Wolbachia ; }, abstract = {The tsetse fly Glossina is the vector of the protozoan Trypanosoma brucei spp., which causes Human and Animal African Trypanosomiasis in sub-Saharan African countries. To supplement their unbalanced vertebrate bloodmeal diet, flies permanently harbor the obligate bacterium Wigglesworthia glossinidia, which resides in bacteriocytes in the midgut bacteriome organ as well as in milk gland organ. Tsetse flies also harbor the secondary facultative endosymbionts (S-symbiont) Sodalis glossinidius that infects various tissues and Wolbachia that infects germ cells. Tsetse flies display viviparous reproductive biology where a single embryo hatches and completes its entire larval development in utero and receives nourishments in the form of milk secreted by mother's accessory glands (milk glands). To analyze the precise tissue distribution of the three endosymbiotic bacteria and to infer the way by which each symbiotic partner is transmitted from parent to progeny, we conducted a Fluorescence In situ Hybridization (FISH) study to survey bacterial spatial distribution across the fly tissues. We show that bacteriocytes are mono-infected with Wigglesworthia, while both Wigglesworthia and Sodalis are present in the milk gland lumen. Sodalis was further seen in the uterus, spermathecae, fat body, milk and intracellular in the milk gland cells. Contrary to Wigglesworthia and Sodalis, Wolbachia were the only bacteria infecting oocytes, trophocytes, and embryos at early embryonic stages. Furthermore, Wolbachia were not seen in the milk gland and in the fat body. This work further highlights the diversity of symbiont interactions in multipartner associations and supports two maternal routes of symbiont inheritance in the tsetse fly: Wolbachia through oocytes, and, Wigglesworthia and Sodalis by means of milk gland bacterial infection at early post-embryonic stages.}, }
@article {pmid22536103, year = {2012}, author = {Cordaux, R and Pichon, S and Hatira, HB and Doublet, V and Grève, P and Marcadé, I and Braquart-Varnier, C and Souty-Grosset, C and Charfi-Cheikhrouha, F and Bouchon, D}, title = {Widespread Wolbachia infection in terrestrial isopods and other crustaceans.}, journal = {ZooKeys}, volume = {}, number = {176}, pages = {123-131}, pmid = {22536103}, issn = {1313-2970}, abstract = {Wolbachia bacteria are obligate intracellular alpha-Proteobacteria of arthropods and nematodes. Although widespread among isopod crustaceans, they have seldom been found in non-isopod crustacean species. Here, we report Wolbachia infection in fourteen new crustacean species. Our results extend the range of Wolbachia infections in terrestrial isopods and amphipods (class Malacostraca). We report the occurrence of two different Wolbachia strains in two host species (a terrestrial isopod and an amphipod). Moreover, the discovery of Wolbachia in the goose barnacle Lepas anatifera (subclass Thecostraca) establishes Wolbachia infection in class Maxillopoda. The new bacterial strains are closely related to B-supergroup Wolbachia strains previously reported from crustacean hosts. Our results suggest that Wolbachia infection may be much more widespread in crustaceans than previously thought. The presence of related Wolbachia strains in highly divergent crustacean hosts suggests that Wolbachia endosymbionts can naturally adapt to a wide range of crustacean hosts. Given the ability of isopod Wolbachia strains to induce feminization of genetic males or cytoplasmic incompatibility, we speculate that manipulation of crustacean-borne Wolbachia bacteria might represent potential tools for controlling crustacean species of commercial interest and crustacean or insect disease vectors.}, }
@article {pmid22535248, year = {2012}, author = {Oka, T and Hikoso, S and Yamaguchi, O and Taneike, M and Takeda, T and Tamai, T and Oyabu, J and Murakawa, T and Nakayama, H and Nishida, K and Akira, S and Yamamoto, A and Komuro, I and Otsu, K}, title = {Mitochondrial DNA that escapes from autophagy causes inflammation and heart failure.}, journal = {Nature}, volume = {485}, number = {7397}, pages = {251-255}, pmid = {22535248}, issn = {1476-4687}, support = {CH/11/3/29051/BHF_/British Heart Foundation/United Kingdom ; RG/11/12/29052/BHF_/British Heart Foundation/United Kingdom ; }, mesh = {Alleles ; Animals ; Aorta/pathology ; *Autophagy ; Cardiomegaly/etiology ; Constriction, Pathologic/complications ; Cytokines/genetics ; DNA, Mitochondrial/*immunology/*metabolism ; Endodeoxyribonucleases/deficiency/genetics/metabolism ; Heart/physiopathology ; Heart Failure/*etiology/immunology/metabolism/*pathology ; Lysosomes/enzymology/metabolism ; Male ; Mice ; Mitochondria ; Myocarditis/*etiology/*immunology/metabolism/pathology ; Myocardium/pathology ; Myocytes, Cardiac/metabolism/pathology ; Pressure ; RNA, Messenger/genetics/metabolism ; Signal Transduction ; Toll-Like Receptor 9/antagonists &amp; inhibitors/deficiency/immunology/metabolism ; }, abstract = {Heart failure is a leading cause of morbidity and mortality in industrialized countries. Although infection with microorganisms is not involved in the development of heart failure in most cases, inflammation has been implicated in the pathogenesis of heart failure. However, the mechanisms responsible for initiating and integrating inflammatory responses within the heart remain poorly defined. Mitochondria are evolutionary endosymbionts derived from bacteria and contain DNA similar to bacterial DNA. Mitochondria damaged by external haemodynamic stress are degraded by the autophagy/lysosome system in cardiomyocytes. Here we show that mitochondrial DNA that escapes from autophagy cell-autonomously leads to Toll-like receptor (TLR) 9-mediated inflammatory responses in cardiomyocytes and is capable of inducing myocarditis and dilated cardiomyopathy. Cardiac-specific deletion of lysosomal deoxyribonuclease (DNase) II showed no cardiac phenotypes under baseline conditions, but increased mortality and caused severe myocarditis and dilated cardiomyopathy 10 days after treatment with pressure overload. Early in the pathogenesis, DNase II-deficient hearts showed infiltration of inflammatory cells and increased messenger RNA expression of inflammatory cytokines, with accumulation of mitochondrial DNA deposits in autolysosomes in the myocardium. Administration of inhibitory oligodeoxynucleotides against TLR9, which is known to be activated by bacterial DNA, or ablation of Tlr9 attenuated the development of cardiomyopathy in DNase II-deficient mice. Furthermore, Tlr9 ablation improved pressure overload-induced cardiac dysfunction and inflammation even in mice with wild-type Dnase2a alleles. These data provide new perspectives on the mechanism of genesis of chronic inflammation in failing hearts.}, }
@article {pmid22531210, year = {2012}, author = {Nakayama, T and Archibald, JM}, title = {Evolving a photosynthetic organelle.}, journal = {BMC biology}, volume = {10}, number = {}, pages = {35}, pmid = {22531210}, issn = {1741-7007}, mesh = {*Biological Evolution ; Cercozoa/*cytology/genetics/*physiology/ultrastructure ; Photosynthesis/physiology ; Plastids/physiology/ultrastructure ; }, abstract = {The evolution of plastids from cyanobacteria is believed to represent a singularity in the history of life. The enigmatic amoeba Paulinella and its 'recently' acquired photosynthetic inclusions provide a fascinating system through which to gain fresh insight into how endosymbionts become organelles.The plastids, or chloroplasts, of algae and plants evolved from cyanobacteria by endosymbiosis. This landmark event conferred on eukaryotes the benefits of photosynthesis--the conversion of solar energy into chemical energy--and in so doing had a huge impact on the course of evolution and the climate of Earth 1. From the present state of plastids, however, it is difficult to trace the evolutionary steps involved in this momentous development, because all modern-day plastids have fully integrated into their hosts. Paulinella chromatophora is a unicellular eukaryote that bears photosynthetic entities called chromatophores that are derived from cyanobacteria and has thus received much attention as a possible example of an organism in the early stages of organellogenesis. Recent studies have unlocked the genomic secrets of its chromatophore 23 and provided concrete evidence that the Paulinella chromatophore is a bona fide photosynthetic organelle 4. The question is how Paulinella can help us to understand the process by which an endosymbiont is converted into an organelle.}, }
@article {pmid22530444, year = {2012}, author = {Behbahani, A}, title = {Wolbachia infection and mitochondrial DNA comparisons among Culex mosquitoes in South West Iran.}, journal = {Pakistan journal of biological sciences : PJBS}, volume = {15}, number = {1}, pages = {54-57}, doi = {10.3923/pjbs.2012.54.57}, pmid = {22530444}, issn = {1028-8880}, mesh = {Animals ; Culex/cytology/*genetics/*microbiology ; DNA, Mitochondrial/*genetics ; Haplotypes ; Insect Vectors/cytology/genetics/microbiology ; Iran ; Wolbachia/genetics/*pathogenicity ; }, abstract = {The control of mosquito borne diseases needs new methods given widespread insecticide resistance in many mosquito species. The inherited endosymbiont Wolbachia, found in many arthropods, provides a biological system to reduce the transmission of these diseases and replace the population of vectors with non-vectors using cytoplasmic incompatibility. The aim of this study was to understand the rate of Wolbachia infection among Culex species in the region and to see the effect of Wolbachia infection on mitochondrial genome. In this study three species of Culex mosquitoes were collected from Shoushtar in south west of Iran and examined for Wolbachia infection by Polymerase Chain Reaction (PCR). All of the C. quinquefasciatus specimens were infected with Wolbachia, while C. tritaeniorynchus and C. theileri showed no infection with Wolbachia. The 340 bp of AT rich of mtDNA was sequenced from 30 individuals, 10 individuals of each species. Three sequence haplotypes were found in C. tritaeniorynchus and C. theileri while there was only one haplotype in C. quinquefasciatus. The reduction of haplotypes diversity may be result of a sweep of Wolbachia in this species.}, }
@article {pmid22529916, year = {2012}, author = {Hanelt, B and Bolek, MG and Schmidt-Rhaesa, A}, title = {Going solo: discovery of the first parthenogenetic gordiid (Nematomorpha: Gordiida).}, journal = {PloS one}, volume = {7}, number = {4}, pages = {e34472}, pmid = {22529916}, issn = {1932-6203}, support = {P20 RR018754/RR/NCRR NIH HHS/United States ; R01 AI044913/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Female ; Helminths/*physiology ; Life Cycle Stages ; Male ; Parthenogenesis/*physiology ; }, abstract = {Despite the severe fitness costs associated with sexual reproduction, its persistence and pervasiveness among multicellular organisms testifies to its intrinsic, short-term advantages. However, the reproductive assurance hypothesis predicts selection favoring asexual reproduction in sparse populations and when mate finding is difficult. Difficulties in finding mates is especially common in parasites, whose life cycles involve multiple hosts, or being released from the host into the external environment where the parasite can find itself trapped without a sexual partner. To solve this problem and guarantee reproduction, parasites in numerous phyla have evolved reproductive strategies, as predicted by the reproductive assurance hypothesis, such as hermaphroditism or parthenogenesis. However, this type of strategy has not been reported from species in the phylum Nematomorpha, whose populations have often been described as sparse. A new Nematomorpha species, Paragordius obamai n. sp., was discovered from Kenya, Africa, and appears to have solved the problem of being trapped without a mate by eliminating the need for males. Paragordius obamai n. sp. represents the first and only known species within this phylum to reproduce asexually. To determine the mechanism of this mating strategy, we ruled out the involvement of reproduction manipulating endosymbionts by use of next generation sequencing data, thus suggesting that parthenogenesis is determined genetically and may have evolved as a means to assure reproduction. Since this new parthenogenetic species and a closely related gonochoristic North American congener, P. varius, are easy to propagate in the laboratory, these gordiids can be used as model systems to test hypotheses on the genetic advantages and disadvantages of asexual reproduction and the genetic determinants of reproductive strategies in parasites.}, }
@article {pmid22529882, year = {2012}, author = {Fagen, JR and Giongo, A and Brown, CT and Davis-Richardson, AG and Gano, KA and Triplett, EW}, title = {Characterization of the Relative Abundance of the Citrus Pathogen Ca. Liberibacter Asiaticus in the Microbiome of Its Insect Vector, Diaphorina citri, using High Throughput 16S rRNA Sequencing.}, journal = {The open microbiology journal}, volume = {6}, number = {}, pages = {29-33}, pmid = {22529882}, issn = {1874-2858}, abstract = {The relationship between the causal agent of Huanglongbing (HLB), Ca. Liberibacter asiaticus(Las), and the naturally occurring endosymbiotic community of its insect vector, the Asian citrus psyllid (ACP), Diaphorina citri, was studied. Variation was observed in the titer of Las within an ACP population feeding on the same material. The cause of this disparity is unknown, and has implications for Las transmission and the spread of HLB. This study utilizes culture independent methods to establish the relationship between the ACP's microbial community and Las acquisition. DNA from 21 psyllids was amplified using universal 16S rRNA primers with Illumina adaptor regions and a sample-specific 7- base identifier. These amplicons were then batch-sequenced on the Illumina platform. The resulting sequences were separated by the identifier, and compared to known sequences in a 16S rRNA database. The microbial communities of each psyllid were compared to determine whether a correlation exists between the ACP's endosymbionts and level of Las acquisition.ACPs were dominated by the same four bacterialgenera regardless of the abundance of Ca.Liberibacter. A combination of qPCR and Illumina sequencing was used to establish an infection gradient among the sampled ACPs. The Ca. Liberibacter titer within the insect was found to have a strong negative relationship with an endosymbiont residing in the syncytium of the mycetocyte and a positive relationship with Wolbachia. These correlations have implications in the acquisition of Las by the ACP as well as the activities of Las within this vector.}, }
@article {pmid22507701, year = {2012}, author = {Rogozin, IB and Carmel, L and Csuros, M and Koonin, EV}, title = {Origin and evolution of spliceosomal introns.}, journal = {Biology direct}, volume = {7}, number = {}, pages = {11}, pmid = {22507701}, issn = {1745-6150}, support = {Z01LM000073-12/LM/NLM NIH HHS/United States ; //Intramural NIH HHS/United States ; }, mesh = {Alternative Splicing ; Animals ; Base Sequence ; Conserved Sequence ; Eukaryota/chemistry/classification/genetics ; *Evolution, Molecular ; Exons ; Genetics, Population ; Genome ; *Introns ; Phylogeny ; RNA Splice Sites ; Selection, Genetic ; Spliceosomes/chemistry/*genetics ; Untranslated Regions ; }, abstract = {Evolution of exon-intron structure of eukaryotic genes has been a matter of long-standing, intensive debate. The introns-early concept, later rebranded 'introns first' held that protein-coding genes were interrupted by numerous introns even at the earliest stages of life's evolution and that introns played a major role in the origin of proteins by facilitating recombination of sequences coding for small protein/peptide modules. The introns-late concept held that introns emerged only in eukaryotes and new introns have been accumulating continuously throughout eukaryotic evolution. Analysis of orthologous genes from completely sequenced eukaryotic genomes revealed numerous shared intron positions in orthologous genes from animals and plants and even between animals, plants and protists, suggesting that many ancestral introns have persisted since the last eukaryotic common ancestor (LECA). Reconstructions of intron gain and loss using the growing collection of genomes of diverse eukaryotes and increasingly advanced probabilistic models convincingly show that the LECA and the ancestors of each eukaryotic supergroup had intron-rich genes, with intron densities comparable to those in the most intron-rich modern genomes such as those of vertebrates. The subsequent evolution in most lineages of eukaryotes involved primarily loss of introns, with only a few episodes of substantial intron gain that might have accompanied major evolutionary innovations such as the origin of metazoa. The original invasion of self-splicing Group II introns, presumably originating from the mitochondrial endosymbiont, into the genome of the emerging eukaryote might have been a key factor of eukaryogenesis that in particular triggered the origin of endomembranes and the nucleus. Conversely, splicing errors gave rise to alternative splicing, a major contribution to the biological complexity of multicellular eukaryotes. There is no indication that any prokaryote has ever possessed a spliceosome or introns in protein-coding genes, other than relatively rare mobile self-splicing introns. Thus, the introns-first scenario is not supported by any evidence but exon-intron structure of protein-coding genes appears to have evolved concomitantly with the eukaryotic cell, and introns were a major factor of evolution throughout the history of eukaryotes.}, }
@article {pmid22506998, year = {2012}, author = {Estes, AM and Hearn, DJ and Burrack, HJ and Rempoulakis, P and Pierson, EA}, title = {Prevalence of Candidatus Erwinia dacicola in wild and laboratory olive fruit fly populations and across developmental stages.}, journal = {Environmental entomology}, volume = {41}, number = {2}, pages = {265-274}, doi = {10.1603/EN11245}, pmid = {22506998}, issn = {1938-2936}, mesh = {Animals ; Female ; Helicobacter/*isolation &amp; purification/physiology ; Italy ; Life Cycle Stages ; Male ; Olea ; Population Density ; Sexual Behavior, Animal ; Sexual Maturation ; Symbiosis ; Tephritidae/growth &amp; development/microbiology/*physiology ; }, abstract = {The microbiome of the olive fruit fly, Bactrocera oleae (Gmelin), a worldwide pest of olives (Olea europaea L.), has been examined for >100 yr as part of efforts to identify bacteria that are plant pathogens vectored by the fly or are beneficial endosymbionts essential for the fly's survival and thus targets for possible biological control. Because tephritid fruit flies feed on free-living bacteria in their environment, distinguishing between the transient, acquired bacteria of their diet and persistent, resident bacteria that are vertically transmitted endosymbionts is difficult. Several culture-dependent and -independent studies have identified a diversity of species in the olive fruit fly microbiome, but they have not distinguished the roles of the microbes. Candidatus Erwinia dacicola, has been proposed to be a coevolved endosymbiont of the olive fruit fly; however, this was based on limited samples from two Italian populations. Our study shows that C. Erwinia dacicola was present in all New and Old World populations and in the majority of individuals of all life stages sampled in 2 yr. Olive fruit flies reared on olives in the laboratory had frequencies of C. Erwinia dacicola similar to that of wild populations; however, flies reared on artificial diets containing antibiotics in the laboratory rarely had the endosymbiont. The relative abundance of C. Erwinia dacicola varied across development stages, being most abundant in ovipositing females and larvae. This uniform presence of C. Erwini dacicola suggests that it is a persistent, resident endosymbiont of the olive fruit fly.}, }
@article {pmid22505145, year = {2012}, author = {Neves, RC and Kristensen, RM and Funch, P}, title = {Ultrastructure and morphology of the cycliophoran female.}, journal = {Journal of morphology}, volume = {273}, number = {8}, pages = {850-869}, doi = {10.1002/jmor.20025}, pmid = {22505145}, issn = {1097-4687}, mesh = {Animals ; Female ; Invertebrates/*anatomy &amp; histology/ultrastructure ; *Life Cycle Stages ; Microscopy, Electron, Transmission ; Muscles/anatomy &amp; histology/physiology/ultrastructure ; Nervous System/anatomy &amp; histology/ultrastructure ; Phylogeny ; }, abstract = {Knowledge on the morphology of the cycliophoran female has mostly been based on observations of immature females in brood chambers of feeding stages. With the use of light- and transmission electron microscopy, the morphology and ultrastructure of the free and fully mature female of Cycliophora is described now for the first time. The external morphology is characterized by a ciliation consisting of an anteroventral ciliated field, a posterior ciliated tuft, and four sensory structures extending anteriorly from the anteroventral ciliated field. In addition, a small ciliated structure in the midventral region is interpreted as a round-shaped gonopore. Internally, a bilateral cerebral ganglion is situated in the anterior region and a large oocyte is located medially in the body. Several glands are present anteriorly, while posteriorly a pair of glands is associated with the ciliated tuft. Dorsal and ventral longitudinal muscles, as well as, dorsoventral muscles are identified by electron microscopy. Muscle fibers attach to the endocuticle via the epidermis, by means of attachment fibers. An unknown endosymbiont is present throughout the body of the female. We discuss the functional implications of the morphological and ultrastructural aspects of the cycliophoran female. Finally, we compare this life cycle stage with that fromother phyla, suggested as phylogenetically close.}, }
@article {pmid22504806, year = {2012}, author = {Matsuura, Y and Kikuchi, Y and Meng, XY and Koga, R and Fukatsu, T}, title = {Novel clade of alphaproteobacterial endosymbionts associated with stinkbugs and other arthropods.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {12}, pages = {4149-4156}, pmid = {22504806}, issn = {1098-5336}, mesh = {Alphaproteobacteria/*classification/genetics/*isolation &amp; purification/physiology ; Animals ; Arthropods/*microbiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Here we report a novel clade of secondary endosymbionts associated with insects and other arthropods. Seed bugs of the genus Nysius (Hemiptera: Lygaeidae) harbor the primary gammaproteobacterial symbiont Schneideria nysicola within a pair of bacteriomes in the abdomen. Our survey of Nysius species for their facultative bacterial associates consistently yielded a novel type of alphaproteobacterial 16S rRNA gene sequence in addition to those of Wolbachia. Diagnostic PCR survey of 343 individuals representing 24 populations of four Nysius species revealed overall detection rates of the alphaproteobacteria at 77.6% in Nysius plebeius, 87.7% in Nysius sp. 1, 81.0% in Nysius sp. 2, and 100% in Nysius expressus. Further survey of diverse stinkbugs representing 24 families, 191 species, and 582 individuals detected the alphaproteobacteria from an additional 12 species representing six families. Molecular phylogenetic analysis showed that the alphaproteobacteria from the stinkbugs form a distinct and coherent monophyletic group in the order Rickettsiales together with several uncharacterized endosymbionts from fleas and ticks. The alphaproteobacterial symbiont clade was allied to bacterial clades such as the endosymbionts of acanthamoebae, the endosymbionts of cnidarians, and Midichloria spp., the mitochondrion-associated endosymbionts of ticks. In situ hybridization and electron microscopy identified small filamentous bacterial cells in various tissues of N. plebeius, including the bacteriome and ovary. The concentrated localization of the symbiont cells at the anterior pole of oocytes indicated its vertical transmission route through host insect generations. The designation "Candidatus Lariskella arthropodarum" is proposed for the endosymbiont clade.}, }
@article {pmid22504542, year = {2012}, author = {Kwiatkowski, M and Vorburger, C}, title = {Modeling the ecology of symbiont-mediated protection against parasites.}, journal = {The American naturalist}, volume = {179}, number = {5}, pages = {595-605}, doi = {10.1086/665003}, pmid = {22504542}, issn = {1537-5323}, mesh = {Animals ; Aphids/microbiology/*parasitology ; Ecosystem ; *Host-Parasite Interactions ; *Models, Biological ; Population Dynamics ; *Symbiosis ; Wasps/*physiology ; }, abstract = {There is increasing evidence that many maternally transmitted symbionts protect their hosts against parasites, thus ensuring their own persistence. Despite the protection they provide, such symbionts are typically found in only a fraction of the host population. This suggests that symbiont-conferred resistance is costly or that the maternal inheritance of symbionts is not perfect. To investigate these hypotheses and other properties of this complex ecological system, we develop a mathematical model based on the example of bacterial endosymbionts that protect aphids against parasitoid wasps. Simulations show that in the absence of more complex effects, a very fine balance between the costs of harboring symbionts and the strength of protection they provide is required to maintain coexistence of protected and unprotected hosts. These constraints are significantly relaxed and coexistence becomes a common outcome if deployment of symbiont-provided defenses upon a parasite attack entails an additional (induced) cost. Transmission rates of symbionts also affect coexistence, which is more frequently observed under high (but not perfect) fidelity of vertical transfer and low rates of horizontal transfer. Finally, we show that the prevalence of defensive symbionts has a strong influence on the population dynamics of hosts and parasites: population sizes are stable if and only if protected hosts dominate.}, }
@article {pmid22504433, year = {2012}, author = {Wu, K and Hoy, MA}, title = {Cardinium is associated with reproductive incompatibility in the predatory mite Metaseiulus occidentalis (Acari: Phytoseiidae).}, journal = {Journal of invertebrate pathology}, volume = {110}, number = {3}, pages = {359-365}, doi = {10.1016/j.jip.2012.03.027}, pmid = {22504433}, issn = {1096-0805}, mesh = {Animals ; Bacterial Infections/microbiology/*veterinary ; Bacteroidetes/*physiology ; Breeding ; Crosses, Genetic ; Female ; Fertility/physiology ; Host-Pathogen Interactions/*physiology ; Longevity ; Male ; Mites/*microbiology/physiology ; Pest Control, Biological ; Reproduction/*physiology ; Sex Factors ; Symbiosis/physiology ; }, abstract = {Cardinium, a bacterium from the Bacteroidetes group, is associated with reproductive manipulations such as cytoplasmic incompatibility, parthenogenesis, and feminization in some arthropod species. We, and others, have shown that Cardinium, but not Wolbachia, is an endosymbiont in some populations of Metaseiulus occidentalis, a phytoseiid mite that is an important predator of spider mite pests of agricultural crops. However, the precise biological effects that Cardinium may have on M. occidentalis remain unclear. In this study we show, in two sets of crosses between different colonies of Cardinium-free (C-) M. occidentalis females and Cardinium-containing (C+) males, that fecundity was reduced in parental females, F1 progeny survival rates were reduced, and fewer female progeny were produced when compared to the reciprocal and control crosses. There were no differences in these attributes in the reciprocal and two control crosses. Cardinium was transmitted maternally but there was no observed paternal transmission. Finally, Cardinium did not cause asexual (thelytoky) reproduction in M. occidentalis. Thus, Cardinium is associated with nonreciprocal reproductive incompatibility in M. occidentalis and our results support the hypothesis that Cardinium is a reproductive parasite in this agriculturally important predator. Cardinium may therefore affect the evolution and ecology of M. occidentalis and biological control efforts using this mite.}, }
@article {pmid22503505, year = {2012}, author = {Fuentes, I and Karcher, D and Bock, R}, title = {Experimental reconstruction of the functional transfer of intron-containing plastid genes to the nucleus.}, journal = {Current biology : CB}, volume = {22}, number = {9}, pages = {763-771}, doi = {10.1016/j.cub.2012.03.005}, pmid = {22503505}, issn = {1879-0445}, mesh = {*Cell Nucleus ; *Introns ; Plants/genetics ; *Plasmids ; RNA Splicing ; Transcriptome ; }, abstract = {BACKGROUND: Eukaryotic cells arose through the uptake of bacterial endosymbionts and their gradual conversion into cell organelles (mitochondria and chloroplasts). In this process, a massive transfer of genes from the genome of the endosymbiont to the nuclear genome of the host cell occurred. Whereas intron-free organellar genes could conceivably enter the nucleus as DNA pieces and become functional nuclear genes, the transfer mechanisms of organellar genes containing prokaryotic-type group I or group II introns are not clear.<br><br>RESULTS: We describe an experimental system that allows us to screen for functional endosymbiotic gene transfer of intron-containing chloroplast genes to the nuclear genome. To distinguish between DNA-mediated and RNA/complementary DNA-mediated transfer, we have constructed an antibiotic resistance gene that is interrupted by a chloroplast group II intron and whose expression is dependent upon both intron removal and gene transfer from the chloroplast genome to the nuclear genome. Screening chloroplast-transformed tobacco plants for the acquisition of the antibiotic resistance via gene transfer to the nucleus, a large number of transfer events were selected. We show that all events involved the direct DNA-mediated transfer of the intron-containing chloroplast gene into the nuclear genome. Gene activity in the nucleus is brought about by utilization of cryptic splice sites within chloroplast intron sequences resulting in appearance of a contiguous reading frame.<br><br>CONCLUSION: Our data pinpoint mechanisms for the functional transfer of organellar genes to the nucleus and demonstrate that intron possession is not an insurmountable obstacle to DNA-mediated endosymbiotic gene transfer.}, }
@article {pmid22500583, year = {2012}, author = {Caragata, EP and Walker, T}, title = {Using bacteria to treat diseases.}, journal = {Expert opinion on biological therapy}, volume = {12}, number = {6}, pages = {701-712}, doi = {10.1517/14712598.2012.677429}, pmid = {22500583}, issn = {1744-7682}, mesh = {Animals ; Culicidae/growth &amp; development/*microbiology/*parasitology ; Dengue/epidemiology/parasitology/*prevention &amp; control/transmission ; Humans ; *Insect Vectors ; Larva/microbiology/parasitology ; Malaria/epidemiology/parasitology/*prevention &amp; control/transmission ; Mosquito Control/*methods ; Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {INTRODUCTION: Mosquito-borne diseases such as malaria and dengue fever result in significant morbidity and mortality in developing countries. Vector control is often the most effective strategy to prevent disease transmission and novel methods are required to complement existing insecticide-based strategies. Biological control uses natural predators or pathogens to kill mosquitoes or reduce their capacity to transmit disease. Bacteria such as Wolbachia have been proposed to have the potential to provide effective biological control of mosquitoes.<br><br>AREAS COVERED: A review of the potential role of bacteria in the control of mosquito-borne diseases highlighting the advantages and disadvantages of each strategy. In particular, a comprehensive summary of the progress made using the bacterial endosymbiont Wolbachia for dengue control.<br><br>EXPERT OPINION: Pathogenic bacteria such as Bti can be used to kill mosquito larvae and several endosymbiotic bacteria such as Asaia could be genetically transformed to alter the mosquito's ability to transmit pathogens. The endosymbiotic bacterium Wolbachia has been successfully introduced into the principal vector of dengue, Aedes aegypti, and induces a variety of phenotypic effects that are predicted to reduce dengue transmission. The release of Wolbachia-infected mosquitoes has been undertaken as part of preliminary trials to determine the applied use of this bacterium for mosquito-borne disease control.}, }
@article {pmid22497736, year = {2012}, author = {Pichon, S and Bouchon, D and Liu, C and Chen, L and Garrett, RA and Grève, P}, title = {The expression of one ankyrin pk2 allele of the WO prophage is correlated with the Wolbachia feminizing effect in isopods.}, journal = {BMC microbiology}, volume = {12}, number = {}, pages = {55}, pmid = {22497736}, issn = {1471-2180}, mesh = {Alleles ; Animals ; Ankyrins/*genetics ; Female ; Gene Expression Profiling ; *Gene Expression Regulation, Viral ; Isopoda/*microbiology/physiology ; Male ; Molecular Sequence Data ; Prophages/*genetics ; Sequence Analysis, DNA ; Sex Characteristics ; Viral Proteins/*biosynthesis/genetics ; Wolbachia/*virology ; }, abstract = {BACKGROUND: The maternally inherited α-Proteobacteria Wolbachia pipientis is an obligate endosymbiont of nematodes and arthropods, in which they induce a variety of reproductive alterations, including Cytoplasmic Incompatibility (CI) and feminization. The genome of the feminizing wVulC Wolbachia strain harboured by the isopod Armadillidium vulgare has been sequenced and is now at the final assembly step. It contains an unusually high number of ankyrin motif-containing genes, two of which are homologous to the phage-related pk1 and pk2 genes thought to contribute to the CI phenotype in Culex pipiens. These genes encode putative bacterial effectors mediating Wolbachia-host protein-protein interactions via their ankyrin motifs.<br><br>RESULTS: To test whether these Wolbachia homologs are potentially involved in altering terrestrial isopod reproduction, we determined the distribution and expression of both pk1 and pk2 genes in the 3 Wolbachia strains that induce CI and in 5 inducing feminization of their isopod hosts. Aside from the genes being highly conserved, we found a substantial copy number variation among strains, and that is linked to prophage diversity. Transcriptional analyses revealed expression of one pk2 allele (pk2b2) only in the feminizing Wolbachia strains of isopods.<br><br>CONCLUSIONS: These results reveal the need to investigate the functions of Wolbachia ankyrin gene products, in particular those of Pk2, and their host targets with respect to host sex manipulation.}, }
@article {pmid22496841, year = {2012}, author = {Pancsa, R and Tompa, P}, title = {Structural disorder in eukaryotes.}, journal = {PloS one}, volume = {7}, number = {4}, pages = {e34687}, pmid = {22496841}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Eukaryota/*chemistry ; Evolution, Molecular ; Molecular Sequence Data ; Prokaryotic Cells/*chemistry ; Proteins/*chemistry ; Proteome/*chemistry ; }, abstract = {Based on early bioinformatic studies on a handful of species, the frequency of structural disorder of proteins is generally thought to be much higher in eukaryotes than in prokaryotes. To refine this view, we present here a comparative prediction study and analysis of 194 fully described eukaryotic proteomes and 87 reference prokaryotes for structural disorder. We found that structural disorder does distinguish eukaryotes from prokaryotes, but its frequency spans a very wide range in the two superkingdoms that largely overlap. The number of disordered binding regions and different Pfam domain types also contribute to distinguish eukaryotes from prokaryotes. Unexpectedly, the highest levels--and highest variability--of predicted disorder is found in protists, i.e. single-celled eukaryotes, often surpassing more complex eukaryote organisms, plants and animals. This trend contrasts with that of the number of domain types, which increases rather monotonously toward more complex organisms. The level of structural disorder appears to be strongly correlated with lifestyle, because some obligate intracellular parasites and endosymbionts have the lowest levels, whereas host-changing parasites have the highest level of predicted disorder. We conclude that protists have been the evolutionary hot-bed of experimentation with structural disorder, in a period when structural disorder was actively invented and the major functional classes of disordered proteins established.}, }
@article {pmid22494817, year = {2012}, author = {Vavre, F and Charlat, S}, title = {Making (good) use of Wolbachia: what the models say.}, journal = {Current opinion in microbiology}, volume = {15}, number = {3}, pages = {263-268}, doi = {10.1016/j.mib.2012.03.005}, pmid = {22494817}, issn = {1879-0364}, mesh = {Animals ; Arthropods ; *Biological Control Agents ; Biological Evolution ; Female ; Filarioidea ; Host-Pathogen Interactions ; Male ; *Models, Biological ; Symbiosis ; *Wolbachia ; }, abstract = {Wolbachia, probably the most common animal endosymbiont, infects a wide range of arthropods as well as filarial nematodes. Generally vertically transmitted from mothers to offspring, it has evolved various strategies, ranging from brutal male-killing to mutualism, which facilitate invasion and persistence of the infections within host populations. Current interest in Wolbachia as a potential control agent against harmful nematodes and arthropods makes it important to be able to predict Wolbachia epidemiology and evolutionary trajectory. Here we highlight recent theoretical developments and suggest future modelling and empirical directions for basic and applied research in this domain.}, }
@article {pmid22490821, year = {2012}, author = {Miyagishima, SY and Suzuki, K and Okazaki, K and Kabeya, Y}, title = {Expression of the nucleus-encoded chloroplast division genes and proteins regulated by the algal cell cycle.}, journal = {Molecular biology and evolution}, volume = {29}, number = {10}, pages = {2957-2970}, doi = {10.1093/molbev/mss102}, pmid = {22490821}, issn = {1537-1719}, mesh = {Algal Proteins/*genetics/metabolism ; Cell Cycle/*genetics ; Cell Nucleus/*genetics ; Chlamydomonas reinhardtii/cytology/genetics ; Chloroplasts/*genetics ; Cyanobacteria/genetics ; Eukaryota/cytology/*genetics ; *Gene Expression Regulation ; Gene Transfer, Horizontal/genetics ; Genes, Chloroplast/*genetics ; Glaucophyta/cytology/genetics ; Rhodophyta/cytology/genetics ; Symbiosis/genetics ; Time Factors ; }, abstract = {Chloroplasts have evolved from a cyanobacterial endosymbiont and their continuity has been maintained by chloroplast division, which is performed by the constriction of a ring-like division complex at the division site. It is believed that the synchronization of the endosymbiotic and host cell division events was a critical step in establishing a permanent endosymbiotic relationship, such as is commonly seen in existing algae. In the majority of algal species, chloroplasts divide once per specific period of the host cell division cycle. In order to understand both the regulation of the timing of chloroplast division in algal cells and how the system evolved, we examined the expression of chloroplast division genes and proteins in the cell cycle of algae containing chloroplasts of cyanobacterial primary endosymbiotic origin (glaucophyte, red, green, and streptophyte algae). The results show that the nucleus-encoded chloroplast division genes and proteins of both cyanobacterial and eukaryotic host origin are expressed specifically during the S phase, except for FtsZ in one graucophyte alga. In this glaucophyte alga, FtsZ is persistently expressed throughout the cell cycle, whereas the expression of the nucleus-encoded MinD and MinE as well as FtsZ ring formation are regulated by the phases of the cell cycle. In contrast to the nucleus-encoded division genes, it has been shown that the expression of chloroplast-encoded division genes is not regulated by the host cell cycle. The endosymbiotic gene transfer of minE and minD from the chloroplast to the nuclear genome occurred independently on multiple occasions in distinct lineages, whereas the expression of nucleus-encoded MIND and MINE is regulated by the cell cycle in all lineages examined in this study. These results suggest that the timing of chloroplast division in algal cell cycle is restricted by the cell cycle-regulated expression of some but not all of the chloroplast division genes. In addition, it is suggested that the regulation of each division-related gene was established shortly after the endosymbiotic gene transfer, and this event occurred multiple times independently in distinct genes and in distinct lineages.}, }
@article {pmid22486703, year = {2012}, author = {Smith, J}, title = {Tragedy of the commons among antibiotic resistance plasmids.}, journal = {Evolution; international journal of organic evolution}, volume = {66}, number = {4}, pages = {1269-1274}, doi = {10.1111/j.1558-5646.2011.01531.x}, pmid = {22486703}, issn = {1558-5646}, support = {GM33782-17/GM/NIGMS NIH HHS/United States ; }, mesh = {*Biological Evolution ; *Drug Resistance, Microbial ; Escherichia coli/*genetics/pathogenicity ; Gene Transfer, Horizontal ; Genetic Fitness ; Microbial Interactions ; Models, Biological ; Plasmids/*genetics ; Virulence ; }, abstract = {As social interactions are increasingly recognized as important determinants of microbial fitness, sociobiology is being enlisted to better understand the evolution of clinically relevant microbes and, potentially, to influence their evolution to aid human health. Of special interest are situations in which there exists a "tragedy of the commons," where natural selection leads to a net reduction in fitness for all members of a population. Here, I demonstrate the existence of a tragedy of the commons among antibiotic resistance plasmids of bacteria. In serial transfer culture, plasmids evolved a greater ability to superinfect already-infected bacteria, increasing plasmid fitness when evolved genotypes were rare. Evolved plasmids, however, fell victim to their own success, reducing the density of their bacterial hosts when they became common and suffering reduced fitness through vertical transmission. Social interactions can thus be an important determinant of evolution for the molecular endosymbionts of bacteria. These results also identify an avenue of evolution that reduces proliferation of both antibiotic resistance genes and their bacterial hosts.}, }
@article {pmid22458451, year = {2012}, author = {Dreier, A and Stannek, L and Blumenberg, M and Taviani, M and Sigovini, M and Wrede, C and Thiel, V and Hoppert, M}, title = {The fingerprint of chemosymbiosis: origin and preservation of isotopic biosignatures in the nonseep bivalve Loripes lacteus compared with Venerupis aurea.}, journal = {FEMS microbiology ecology}, volume = {81}, number = {2}, pages = {480-493}, doi = {10.1111/j.1574-6941.2012.01374.x}, pmid = {22458451}, issn = {1574-6941}, mesh = {Animal Shells/*chemistry ; Animals ; Bacteria/*enzymology/genetics ; Bivalvia/chemistry/*microbiology ; Carbon Cycle ; Carbon Isotopes/*analysis ; Fossils ; Glutamate-Ammonia Ligase/analysis ; Nitrogen/chemistry ; Nitrogen Isotopes/analysis ; Oxidation-Reduction ; Oxidoreductases Acting on Sulfur Group Donors/analysis ; RNA, Ribosomal, 16S/genetics ; Ribulose-Bisphosphate Carboxylase/analysis ; Sulfur/analysis ; Sulfur Isotopes/analysis ; *Symbiosis ; }, abstract = {Endosymbionts in marine bivalves leave characteristic biosignatures in their host organisms. Two nonseep bivalve species collected in Mediterranean lagoons, thiotrophic symbiotic Loripes lacteus and filter-feeding nonsymbiotic Venerupis aurea, were studied in detail with respect to generation and presence of such signatures in living animals, and the preservation of these signals in subfossil (late Pleistocene) sedimentary shells. Three key enzymes from sulfur oxidation (APS-reductase), CO(2) fixation (RubisCO) and assimilation of nitrogen [glutamine synthetase (GS)] were detected by immunofluorescence in the bacterial symbionts of Loripes. In Loripes, major activity was derived from GS of the symbionts whereas in Venerupis the host GS is active. In search of geologically stable biosignatures for thiotrophic chemosymbiosis that might be suitable to detect such associations in ancient bivalves, we analyzed the isotopic composition of shell lipids (δ(13)C) and the bulk organic matrix of the shell (δ(13)C , δ(15)N , δ(34)S). In the thiotrophic Loripes, δ(13)C values were depleted compared with the filter-feeding Venerupis by as much as 8.5‰ for individual fatty acids, and 4.4‰ for bulk organic carbon. Likewise, bulk δ(15)N and δ(34)S values were more depleted in recent thiotrophic Loripes. Whereas δ (34)S values were found to be unstable over time, the combined δ(15)N and δ(13)C values in organic shell extracts revealed a specific signature for chemosymbiosis in recent and subfossil specimens.}, }
@article {pmid22456448, year = {2012}, author = {Gehringer, MM and Adler, L and Roberts, AA and Moffitt, MC and Mihali, TK and Mills, TJ and Fieker, C and Neilan, BA}, title = {Nodularin, a cyanobacterial toxin, is synthesized in planta by symbiotic Nostoc sp.}, journal = {The ISME journal}, volume = {6}, number = {10}, pages = {1834-1847}, pmid = {22456448}, issn = {1751-7370}, mesh = {Amino Acid Sequence ; Arginine/genetics/metabolism ; Bacterial Toxins/*biosynthesis ; Chlorophyll/analysis ; Chlorophyll A ; Chromatography, High Pressure Liquid ; DNA, Bacterial/genetics ; Molecular Sequence Data ; Multigene Family ; Nitrogen Fixation/genetics ; Nostoc/genetics/*metabolism ; Peptides, Cyclic/*biosynthesis ; Phylogeny ; Plant Roots/microbiology ; Spectrometry, Mass, Electrospray Ionization ; *Symbiosis ; Tandem Mass Spectrometry ; Zamiaceae/*microbiology ; }, abstract = {The nitrogen-fixing bacterium, Nostoc, is a commonly occurring cyanobacterium often found in symbiotic associations. We investigated the potential of cycad cyanobacterial endosymbionts to synthesize microcystin/nodularin. Endosymbiont DNA was screened for the aminotransferase domain of the toxin biosynthesis gene clusters. Five endosymbionts carrying the gene were screened for bioactivity. Extracts of two isolates inhibited protein phosphatase 2A and were further analyzed using electrospray ionization mass spectrometry (ESI-MS)/MS. Nostoc sp. 'Macrozamia riedlei 65.1' and Nostoc sp. 'Macrozamia serpentina 73.1' both contained nodularin. High performance liquid chromatography (HPLC) HESI-MS/MS analysis confirmed the presence of nodularin at 9.55±2.4 ng μg-1 chlorophyll a in Nostoc sp. 'Macrozamia riedlei 65.1' and 12.5±8.4 ng μg-1 Chl a in Nostoc sp. 'Macrozamia serpentina 73.1' extracts. Further scans indicated the presence of the rare isoform [L-Har(2)] nodularin, which contains L-homoarginine instead of L-arginine. Nodularin was also present at 1.34±0.74 ng ml(-1) (approximately 3 pmol per g plant ww) in the methanol root extracts of M. riedlei MZ65, while the presence of [L-Har(2)] nodularin in the roots of M. serpentina MZ73 was suggested by HPLC HESI-MS/MS analysis. The ndaA-B and ndaF genomic regions were sequenced to confirm the presence of the hybrid polyketide/non-ribosomal gene cluster. A seven amino-acid insertion into the NdaA-C1 domain of N. spumigena NSOR10 protein was observed in all endosymbiont-derived sequences, suggesting the transfer of the nda cluster from N. spumigena to terrestrial Nostoc species. This study demonstrates the synthesis of nodularin and [L-Har(2)] nodularin in a non-Nodularia species and the production of cyanobacterial hepatotoxin by a symbiont in planta.}, }
@article {pmid22450512, year = {2012}, author = {Watanabe, M and Tagami, Y and Miura, K and Kageyama, D and Stouthamer, R}, title = {Distribution patterns of Wolbachia endosymbionts in the closely related flower bugs of the genus Orius: implications for coevolution and horizontal transfer.}, journal = {Microbial ecology}, volume = {64}, number = {2}, pages = {537-545}, pmid = {22450512}, issn = {1432-184X}, mesh = {Animals ; *Biological Evolution ; Cloning, Molecular ; Flowers/*parasitology ; *Gene Transfer, Horizontal ; Heteroptera/classification/*microbiology ; Japan ; Molecular Sequence Data ; Multilocus Sequence Typing ; Phylogeny ; Recombination, Genetic ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Wolbachia/classification/*genetics/physiology ; }, abstract = {Vertical transmission is the primary route of the endosymbiont Wolbachia for its own spread among invertebrate hosts, but horizontal transmission between different hosts is believed to have occurred multiple times. However, it is not well known how Wolbachia commonly spread among closely related hosts. We focused on the closely related species of the minute pirate bugs belonging to the genus Orius, which are important biological control agents in agricultural crops because they are the most useful natural enemy of various tiny pests, such as thrips. Here, we examined five Orius species (Orius sauteri, Orius nagaii, Orius minutus, Orius strigicollis, and Orius tantillus) from eight geographic localities in Japan for Wolbachia infection. Two distinct strains, wOus1 and wOus2, were detected based on Wolbachia surface protein (wsp) gene sequencing. Furthermore, multilocus sequence typing revealed that each of the strains comprised two variants that differed in a single nucleotide. The overall distribution patterns of the two Wolbachia strains were found to differ among host species: prevalent double infection with wOus1 and wOus2 in O. strigicollis; fixation of single infection with wOus2 in O. nagaii; occurrence of single infection with wOus1 in O. sauteri; prevalence of single infection with wOus1 in O. minutus with an exception in a single population; and lack of Wolbachia infection in O. tantillus. Such differences in the distribution patterns of Wolbachia may reflect the evolutionary history of Wolbachia infection among Orius species and/or ecological and physiological differences among the Orius species that determine the invasiveness and maintenance of the two Wolbachia strains.}, }
@article {pmid22448083, year = {2011}, author = {Kumar, S and Blaxter, ML}, title = {Simultaneous genome sequencing of symbionts and their hosts.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {55}, number = {3}, pages = {119-126}, pmid = {22448083}, issn = {0334-5114}, support = {G0900740/MRC_/Medical Research Council/United Kingdom ; }, abstract = {Second-generation sequencing has made possible the sequencing of genomes of interest for even small research groups. However, obtaining separate clean cultures and clonal or inbred samples of metazoan hosts and their bacterial symbionts is often difficult. We present a computational pipeline for separating metazoan and bacterial DNA in silico rather than at the bench. The method relies on the generation of deep coverage of all the genomes in a mixed sample using Illumina short-read sequencing technology, and using aggregate properties of the different genomes to identify read sets belonging to each. This inexpensive and rapid approach has been used to sequence several nematode genomes and their bacterial endosymbionts in the last year in our laboratory and can also be used to visualize and identify unexpected contaminants (or possible symbionts) in genomic DNA samples. We hope that this method will enable researchers studying symbiotic systems to move from gene-centric to genome-centric approaches.}, }
@article {pmid22447322, year = {2012}, author = {Yamagishi, T and Kai, A and Kawai, H}, title = {Trichocyst ribbons of a cryptomonads are constituted of homologs of R-body proteins produced by the intracellular parasitic bacterium of Paramecium.}, journal = {Journal of molecular evolution}, volume = {74}, number = {3-4}, pages = {147-157}, pmid = {22447322}, issn = {1432-1432}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*chemistry ; Biological Evolution ; Cryptophyta/chemistry/*cytology ; Molecular Sequence Annotation ; Molecular Sequence Data ; Organelles/*chemistry/ultrastructure ; Paramecium/*microbiology ; Protein Structure, Secondary ; Proteins/chemistry ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {Trichocysts are ejectile organelles found in cryptomonads, dinoflagellates, and peniculine ciliates. The fine structure of trichocysts differs considerably among lineages, and their evolutionary relationships are unclear. The biochemical makeup of the trichocyst constituents has been studied in the ciliate Paramecium, but there have been no investigations of cryptomonads and dinoflagellates. Furthermore, morphological similarity between the contents of cryptomonad trichocysts and the R-bodies of the endosymbiotic bacteria of Paramecium has been reported. In this study, we identified the proteins of the trichocyst constituents in a red cryptomonad, Pyrenomonas helgolandii, and found their closest relationships to be with rebB that comprises the R-bodies of Caedibacter taeniospiralis (gammaproteobacteria), which is an endosymbiont of Paramecium. In addition, the biochemical makeups of the trichocysts are entirely different between cryptomonads and peniculine ciliates, and therefore, cryptomonad trichocysts have an evolutionary origin independent from the peniculine ciliate trichocysts.}, }
@article {pmid22438018, year = {2012}, author = {Elisabeth, NH and Gustave, SD and Gros, O}, title = {Cell proliferation and apoptosis in gill filaments of the lucinid Codakia orbiculata (Montagu, 1808) (Mollusca: Bivalvia) during bacterial decolonization and recolonization.}, journal = {Microscopy research and technique}, volume = {75}, number = {8}, pages = {1136-1146}, doi = {10.1002/jemt.22041}, pmid = {22438018}, issn = {1097-0029}, mesh = {Animals ; *Apoptosis ; Bivalvia/*microbiology/physiology ; Cell Count ; Cell Division ; *Cell Proliferation ; Cell Size ; Food Deprivation ; Gammaproteobacteria/*growth &amp; development ; Gills/*microbiology/physiology/ultrastructure ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; *Regeneration ; *Symbiosis ; }, abstract = {The shallow-water bivalve Codakia orbiculata which harbors gill-endosymbiotic sulfur-oxidizing γ-proteobacteria can lose and acquire its endosymbionts throughout its life. Long-term starvation and recolonization experiments led to changes in the organization of cells in the lateral zone of gill filaments. This plasticity is linked to the presence or absence of gill-endosymbionts. Herein, we propose that this reorganization can be explained by three hypotheses: (a) a variation in the number of bacteriocytes and granule cells due to proliferation or apoptosis processes, (b) a variation of the volume of these two cell types without modification in the number, and (c) a combination of both number and cell volume variation. To test these hypotheses, we analyzed cell reorganization in terms of proliferation and apoptosis in adults submitted to starvation and returned to the field using catalyzed reporter deposition fluorescence in situ hybridization, immunohistochemistry, and structural analyses. We observed that cell and tissue reorganization in gills filaments is due to a variation in cell relative abundance that maybe associated with a variation in cell apparent volume and depends on the environment. In fact, bacteriocytes mostly multiply in freshly collected and newly recolonized individuals, and excess bacteriocytes are eliminated in later recolonization stages. We highlight that host tissue regeneration in gill filaments of this symbiotic bivalve can occur by both replication of existing cells and division of undifferentiated cells localized in tissular bridges, which might be a tissue-specific multipotent stem cell zone.}, }
@article {pmid22433115, year = {2012}, author = {Zouache, K and Michelland, RJ and Failloux, AB and Grundmann, GL and Mavingui, P}, title = {Chikungunya virus impacts the diversity of symbiotic bacteria in mosquito vector.}, journal = {Molecular ecology}, volume = {21}, number = {9}, pages = {2297-2309}, doi = {10.1111/j.1365-294X.2012.05526.x}, pmid = {22433115}, issn = {1365-294X}, mesh = {Aedes/*microbiology/*virology ; Alphaproteobacteria/physiology ; Animals ; *Bacterial Physiological Phenomena ; Bacteroidetes/physiology ; Biodiversity ; Chikungunya virus/genetics/*physiology ; Enterobacteriaceae/physiology ; Gammaproteobacteria/physiology ; Host-Pathogen Interactions ; Insect Vectors/*microbiology/*virology ; *Symbiosis ; Virus Replication ; Wolbachia/physiology ; }, abstract = {Mosquitoes transmit numerous arboviruses including dengue and chikungunya virus (CHIKV). In recent years, mosquito species Aedes albopictus has expanded in the Indian Ocean region and was the principal vector of chikungunya outbreaks in La Reunion and neighbouring islands in 2005 and 2006. Vector-associated bacteria have recently been found to interact with transmitted pathogens. For instance, Wolbachia modulates the replication of viruses or parasites. However, there has been no systematic evaluation of the diversity of the entire bacterial populations within mosquito individuals particularly in relation to virus invasion. Here, we investigated the effect of CHIKV infection on the whole bacterial community of Ae. albopictus. Taxonomic microarrays and quantitative PCR showed that members of Alpha- and Gammaproteobacteria phyla, as well as Bacteroidetes, responded to CHIKV infection. The abundance of bacteria from the Enterobacteriaceae family increased with CHIKV infection, whereas the abundance of known insect endosymbionts like Wolbachia and Blattabacterium decreased. Our results clearly link the pathogen propagation with changes in the dynamics of the bacterial community, suggesting that cooperation or competition occurs within the host, which may in turn affect the mosquito traits like vector competence.}, }
@article {pmid22429457, year = {2012}, author = {Boyd, BM and Reed, DL}, title = {Taxonomy of lice and their endosymbiotic bacteria in the post-genomic era.}, journal = {Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases}, volume = {18}, number = {4}, pages = {324-331}, doi = {10.1111/j.1469-0691.2012.03782.x}, pmid = {22429457}, issn = {1469-0691}, mesh = {Animals ; Ecology ; Evolution, Molecular ; Gammaproteobacteria/*classification/genetics/growth &amp; development ; Genes, Mitochondrial ; Genetic Markers ; Genetics, Population ; *Genome, Bacterial ; *Genome, Insect ; Mitochondria/genetics ; Phthiraptera/*classification/genetics/*microbiology ; Phylogeny ; Species Specificity ; *Symbiosis ; }, abstract = {Recent studies of molecular and genomic data from the parasitic lice of birds and mammals, as well as their mutualistic endosymbiotic bacteria, are changing the phylogenetic relationships and taxonomy of these organisms. Phylogenetic studies of lice suggest that vertebrate parasitism arose multiple times from free-living book and bark lice. Molecular clocks show that the major families of lice arose in the late Mesozoic and radiated in the early Cenozoic, following the radiation of mammals and birds. The recent release of the human louse genome has provided new opportunities for research. The genome is being used to find new genetic markers for phylogenetics and population genetics, to understand the complex evolutionary relationships of mitochondrial genes, and to study genome evolution. Genomes are informing us not only about lice, but also about their obligate endosymbiotic bacteria. In contrast to lice and their hosts, lice and their endosymbionts do not share common evolutionary histories, suggesting that endosymbionts are either replaced over time or that there are multiple independent origins of symbiosis in lice. Molecular phylogenetics and whole genome sequencing have recently provided the first insights into the phylogenetic placement and metabolic characteristics of these distantly related bacteria. Comparative genomics between distantly related louse symbionts can provide insights into conserved metabolic functions and can help to explain how distantly related species are fulfilling their role as mutualistic symbionts. In lice and their endosymbionts, molecular data and genome sequencing are driving our understanding of evolutionary relationships and classification, and will for the foreseeable future.}, }
@article {pmid22428117, year = {2012}, author = {Wakahama, T and Okuyama, H and Maoka, T and Takaichi, S}, title = {Unique carotenoid lactoside, P457, in Symbiodinium sp. of dinoflagellate.}, journal = {Acta biochimica Polonica}, volume = {59}, number = {1}, pages = {155-157}, pmid = {22428117}, issn = {1734-154X}, mesh = {Carotenoids/*chemistry ; Dinoflagellida/*chemistry ; Lactose/*analogs &amp; derivatives/chemistry ; Molecular Structure ; }, abstract = {The dinoflagellates are a large group of unicellular alge in marine and fresh water. Some are an endosymbiont of marine animals. Photosynthetic dinoflagellates have peridinin, a light-harvesting carotenoid. In addition, a unique carotenoid, P457, was found from Amphinidium. The presence of P457 in Symbiodinium derived from marine animals has not been reported. We reconfirmed the molecular structure of P457, a neoxanthin-like carotenoid with an aldehyde group and a lactoside, from Symbiodinium sp. NBRC 104787 isolated from a sea anemone. In addition, we investigated the distribution of P457 and peridinin in various Symbiodinium and scleractinian coral species, and possible biosynthetic pathways of these carotenoids are proposed.}, }
@article {pmid22427962, year = {2012}, author = {Edlund, A and Ek, K and Breitholtz, M and Gorokhova, E}, title = {Antibiotic-induced change of bacterial communities associated with the copepod Nitocra spinipes.}, journal = {PloS one}, volume = {7}, number = {3}, pages = {e33107}, pmid = {22427962}, issn = {1932-6203}, mesh = {Animals ; Anti-Bacterial Agents/*toxicity ; Bacteria/*drug effects/genetics ; Base Sequence ; *Biodiversity ; Chromatography, Liquid ; Cloning, Molecular ; Copepoda/*drug effects/growth &amp; development/*microbiology ; DNA Primers/genetics ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; Oceans and Seas ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Species Specificity ; Sweden ; *Symbiosis ; Tandem Mass Spectrometry ; Water Pollutants, Chemical/*toxicity ; }, abstract = {Environmental pressures, such as physical factors, diet and contaminants may affect interactions between microbial symbionts and their multicellular hosts. Despite obvious relevance, effects of antimicrobial contaminants on host-symbiont relations in non-target aquatic organisms are largely unknown. We show that exposure to antibiotics had negative effects on survival and juvenile development of the copepod Nitocra spinipes and caused significant alterations in copepod-associated bacterial communities. The significant positive correlations between indices of copepod development and bacterial diversity indicate that disruption of the microflora was likely to be an important factor behind retarded juvenile development in the experimental animals. Moreover, as evidenced by ribotype distribution in the bacterial clone libraries, the exposure to antibiotics caused a shift in dominance from Betaproteobacteria to Cardinium bacteria; the latter have been shown to cause reproductive manipulations in various terrestrial arthropods. Thus, in addition to providing evidence that the antibiotic-induced perturbation of the microbial community associates with reductions in fitness-related traits of the host, this study is the first record of a copepod serving as a host for endosymbiotic Cardinium. Taken together, our results suggest that (1) antimicrobial substances and possibly other stressors can affect micobiome and symbiont-mediated interactions in copepods and other hosts, and (2) Cardinium endosymbionts may occur in other copepods and affect reproduction of their hosts.}, }
@article {pmid22427798, year = {2012}, author = {Rasgon, JL}, title = {Wolbachia induces male-specific mortality in the mosquito Culex pipiens (LIN strain).}, journal = {PloS one}, volume = {7}, number = {3}, pages = {e30381}, pmid = {22427798}, issn = {1932-6203}, support = {F31 GM020092/GM/NIGMS NIH HHS/United States ; R21 AI070178/AI/NIAID NIH HHS/United States ; GM020092/GM/NIGMS NIH HHS/United States ; AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; *Biological Evolution ; Culex/*microbiology/physiology ; Female ; Genetic Fitness/genetics ; Life Tables ; Longevity/*physiology ; Male ; *Mortality ; Sex Factors ; Wolbachia/*pathogenicity/physiology ; }, abstract = {BACKGROUND: Wolbachia are maternally inherited endosymbionts that infect a diverse range of invertebrates, including insects, arachnids, crustaceans and filarial nematodes. Wolbachia are responsible for causing diverse reproductive alterations in their invertebrate hosts that maximize their transmission to the next generation. Evolutionary theory suggests that due to maternal inheritance, Wolbachia should evolve toward mutualism in infected females, but strict maternal inheritance means there is no corresponding force to select for Wolbachia strains that are mutualistic in males.<br><br>Using cohort life-table analysis, we demonstrate that in the mosquito Culex pipiens (LIN strain), Wolbachia-infected females show no fitness costs due to infection. However, Wolbachia induces up to a 30% reduction in male lifespan.<br><br>CONCLUSIONS/SIGNIFICANCE: These results indicate that the Wolbachia infection of the Culex pipiens LIN strain is virulent in a sex-specific manner. Under laboratory situations where mosquitoes generally mate at young ages, Wolbachia strains that reduce male survival could evolve by drift because increased mortality in older males is not a significant selective force.}, }
@article {pmid22427176, year = {2012}, author = {Vega, IA and Arribére, MA and Almonacid, AV and Ribeiro Guevara, S and Castro-Vazquez, A}, title = {Apple snails and their endosymbionts bioconcentrate heavy metals and uranium from contaminated drinking water.}, journal = {Environmental science and pollution research international}, volume = {19}, number = {8}, pages = {3307-3316}, pmid = {22427176}, issn = {1614-7499}, mesh = {Animals ; Drinking Water/*chemistry ; Female ; Kidney/chemistry ; Metals, Heavy/analysis/*metabolism ; Neutron Activation Analysis ; Snails/*metabolism ; Uranium/analysis/*metabolism ; Water Pollutants, Chemical/analysis/*metabolism ; Water Purification/*methods ; Water Quality ; }, abstract = {PURPOSE: The differential ability of apple snail tissues, endosymbionts, and eggs to bioaccumulate several metals (Sb, As, Ba, Br, Zn, Cr, Fe, Hg, Se, and U) was investigated.<br><br>METHODS: Metal concentrations were determined by neutron activation analysis in several tissues, endosymbionts, and eggs from mature apple snails cultured in either drinking water or reconstituted water (prepared with American Society for Testing and Materials type I water).<br><br>RESULTS: The highest bioconcentration factors (BCFs) in the midgut gland were found for Ba, Zn, Se, As, U, Br, and Hg (in decreasing order), while the highest in the kidney were for Ba, Br, and Hg. The foot showed the highest BCFs for Ba, Hg, Br, and Se (in decreasing order). Calcified tissues (uterus, shell) and eggs showed low BCFs, except for Ba. Both C corpuscles and gland tissue showed statistically higher BCFs than K corpuscles for Ba, Fe, U, Br, and Sb. The concentration of most of the studied elements was significantly lower in tissues and endosymbionts obtained from snails cultured in reconstituted water instead of drinking water. Snails cultured in reconstituted water and then exposed or not to Hg, As, and U (at the maximum contaminant level allowed by the US Environmental Protection Agency) also resulted in high levels accumulated in midgut gland, endosymbionts and kidney.<br><br>CONCLUSIONS: Our findings suggest that the midgut gland (and the symbionts contained therein), the kidney, and the foot of Pomacea canaliculata may be useful bioindicators of Hg, As and U pollution in freshwater bodies and that the unrestricted use of ampullariid snails as human and animal food must be considered with caution.}, }
@article {pmid22419438, year = {2012}, author = {Beukeboom, LW}, title = {Microbial manipulation of host sex determination. Endosymbiotic bacteria can directly manipulate their host's sex determination towards the production of female offspring.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {34}, number = {6}, pages = {484-488}, doi = {10.1002/bies.201100192}, pmid = {22419438}, issn = {1521-1878}, mesh = {Animals ; Biological Evolution ; Female ; Feminization/genetics ; Genotype ; Host-Pathogen Interactions ; Lepidoptera/*genetics/microbiology ; Male ; Reproduction/genetics ; Sex Chromosomes/*genetics ; *Sex Determination Processes ; Symbiosis/*genetics ; Wolbachia/metabolism/*pathogenicity ; }, abstract = {A recent study in the lepidopteran Ostrinia scapulalis shows that endosymbionts can actively manipulate the sex determination mechanism of their host. Wolbachia bacteria alter the sex-specific splicing of the doublesex master switch gene. In ZZ males of this female heterogametic system, the female isoform of doublesex is produced in the presence of the bacteria. The effect is a lethal feminization of genotypic males. Curing of ZW females leads to males that die, indicating that the bacteria have an obligate role in proper sex determination and development of their host. Microbial intervention with host sex determination may be a driving force behind the evolutionary turnover of sex determination mechanisms.}, }
@article {pmid22418845, year = {2012}, author = {del Val, C and Romero-Zaliz, R and Torres-Quesada, O and Peregrina, A and Toro, N and Jiménez-Zurdo, JI}, title = {A survey of sRNA families in α-proteobacteria.}, journal = {RNA biology}, volume = {9}, number = {2}, pages = {119-129}, pmid = {22418845}, issn = {1555-8584}, mesh = {Alphaproteobacteria/*genetics ; Base Sequence ; Computational Biology/methods ; Gene Expression Regulation, Bacterial ; Gene Order ; Molecular Sequence Data ; Nucleic Acid Conformation ; RNA, Bacterial/chemistry/*genetics ; RNA, Small Untranslated/chemistry/*genetics ; Sinorhizobium meliloti/genetics ; }, abstract = {We have performed a computational comparative analysis of six small non-coding RNA (sRNA) families in α-proteobacteria. Members of these families were first identified in the intergenic regions of the nitrogen-fixing endosymbiont S. meliloti by a combined bioinformatics screen followed by experimental verification. Consensus secondary structures inferred from covariance models for each sRNA family evidenced in some cases conserved motifs putatively relevant to the function of trans-encoded base-pairing sRNAs i.e., Hfq-binding signatures and exposed anti Shine-Dalgarno sequences. Two particular family models, namely αr15 and αr35, shared own sub-structural modules with the Rfam model suhB (RF00519) and the uncharacterized sRNA family αr35b, respectively. A third sRNA family, termed αr45, has homology to the cis-acting regulatory element speF (RF00518). However, new experimental data further confirmed that the S. meliloti αr45 representative is an Hfq-binding sRNA processed from or expressed independently of speF, thus refining the Rfam speF model annotation. All the six families have members in phylogenetically related plant-interacting bacteria and animal pathogens of the order of the Rhizobiales, some occurring with high levels of paralogy in individual genomes. In silico and experimental evidences predict differential regulation of paralogous sRNAs in S. meliloti 1021. The distribution patterns of these sRNA families suggest major contributions of vertical inheritance and extensive ancestral duplication events to the evolution of sRNAs in plant-interacting bacteria.}, }
@article {pmid22417790, year = {2012}, author = {Gehrer, L and Vorburger, C}, title = {Parasitoids as vectors of facultative bacterial endosymbionts in aphids.}, journal = {Biology letters}, volume = {8}, number = {4}, pages = {613-615}, pmid = {22417790}, issn = {1744-957X}, mesh = {Animals ; Aphids/*microbiology/parasitology ; Arachnid Vectors/growth &amp; development/*microbiology ; Buchnera/genetics/*growth &amp; development/isolation &amp; purification ; Cell Line ; DNA Primers/genetics ; Female ; Genes, rRNA ; Mite Infestations/parasitology ; Mites/growth &amp; development/*microbiology ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/analysis/genetics ; *Symbiosis ; }, abstract = {Heritable bacterial endosymbionts play an important role in aphid ecology. Sequence-based evidence suggests that facultative symbionts such as Hamiltonella defensa or Regiella insecticola also undergo horizontal transmission. Other than through male-to-female transfer during the sexual generation in autumn, the routes by which this occurs remain largely unknown. Here, we tested if parasitoids or ectoparasitic mites can act as vectors for horizontal transfer of facultative symbionts. Using symbiont-specific primers for diagnostic PCR, we demonstrate for the first time, to our knowledge, that parasitoids can indeed transfer H. defensa and R. insecticola by sequentially stabbing infected and uninfected individuals of their host, Aphis fabae, establishing new, heritable infections. Thus, a natural route of horizontal symbiont transmission is also available during the many clonal generations of the aphid life cycle. No transmissions by ectoparasitic mites were observed, nor did parasitoids that emerged from symbiont-infected aphids transfer any symbionts in our experiments.}, }
@article {pmid22411632, year = {2012}, author = {Torres, L and Almazán, C and Ayllón, N and Galindo, RC and Rosario-Cruz, R and Quiroz-Romero, H and Gortazar, C and de la Fuente, J}, title = {Identification of microorganisms in partially fed female horn flies, Haematobia irritans.}, journal = {Parasitology research}, volume = {111}, number = {3}, pages = {1391-1395}, pmid = {22411632}, issn = {1432-1955}, mesh = {Animals ; Cattle/blood ; Diptera/*microbiology/*physiology ; Expressed Sequence Tags ; Female ; Mycobacterium bovis/classification/genetics/*isolation &amp; purification ; Picornaviridae/classification/genetics/*isolation &amp; purification ; RNA-Directed DNA Polymerase ; Real-Time Polymerase Chain Reaction ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {The horn fly Haematobia irritans (Linnaeus, 1758) (Diptera: Muscidae) is one of the most important ectoparasites of cattle. The parasitism of horn flies interferes with cattle feeding, thus reducing weight gain and milk production. Additionally, horn flies are mechanical vectors of pathogens that cause disease in cattle. The aims of this study were to identify microorganisms in partially fed female horn flies through mining of expressed sequence tags (ESTs) and to characterize microorganism prevalence using real-time RT-PCR. Seven unigenes containing 24 ESTs were homologous to infectious agents. Microorganisms identified in partially fed female horn flies ESTs included Nora virus (3 unigenes; 8 ESTs), Wolbachia endosymbionts (3 unigenes; 3 ESTs), and Mycobacterium bovis (1 unigene; 13 ESTs). These results expanded the repertoire of microorganisms that could cause persistent infections or be mechanically transmitted by horn flies and support further studies on the role of horn flies in the epidemiology of these pathogens in Mexico.}, }
@article {pmid22410786, year = {2012}, author = {Sutcliffe, IC and Harrington, DJ and Hutchings, MI}, title = {A phylum level analysis reveals lipoprotein biosynthesis to be a fundamental property of bacteria.}, journal = {Protein &amp; cell}, volume = {3}, number = {3}, pages = {163-170}, pmid = {22410786}, issn = {1674-8018}, support = {BB/F009429/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Bacteria/*classification/enzymology/*metabolism ; Bacterial Proteins/*biosynthesis/metabolism ; Enzymes/metabolism ; Genome, Bacterial ; Lipoproteins/*biosynthesis/metabolism ; Protein Sorting Signals ; }, abstract = {Bacterial lipoproteins are proteins that are post-translationally modified with a diacylglyceride at an N-terminal cysteine, which serves to tether these proteins to the outer face of the plasma membrane or to the outer membrane. This paper reviews recent insights into the enzymology of bacterial lipoprotein biosynthesis and localization. Moreover, we use bioinformatic analyses of bacterial lipoprotein signal peptide features and of the key biosynthetic enzymes to consider the distribution of lipoprotein biosynthesis at the phylum level. These analyses support the important conclusion that lipoprotein biosynthesis is a fundamental pathway utilized across the domain bacteria. Moreover, with the exception of a small number of sequences likely to derive from endosymbiont genomes, the enzymes of bacterial lipoprotein biosynthesis appear unique to bacteria, making this pathway an attractive target for the development of novel antimicrobials. Whilst lipoproteins with comparable signal peptide features are encoded in the genomes of Archaea, it is clear that these lipoproteins have a distinctive biosynthetic pathway that has yet to be characterized.}, }
@article {pmid22408242, year = {2012}, author = {Mavingui, P and Valiente Moro, C and Tran-Van, V and Wisniewski-Dyé, F and Raquin, V and Minard, G and Tran, FH and Voronin, D and Rouy, Z and Bustos, P and Lozano, L and Barbe, V and González, V}, title = {Whole-genome sequence of Wolbachia strain wAlbB, an endosymbiont of tiger mosquito vector Aedes albopictus.}, journal = {Journal of bacteriology}, volume = {194}, number = {7}, pages = {1840}, pmid = {22408242}, issn = {1098-5530}, mesh = {Aedes/*microbiology/physiology ; Animals ; Base Sequence ; *Genome, Bacterial ; Insect Vectors/*microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; Symbiosis ; Wolbachia/classification/*genetics/isolation &amp; purification/physiology ; }, abstract = {Although bacteria of the genus Wolbachia induced significant extended phenotypes to infected hosts, most molecular mechanisms involved are still unknown. To gain insight into the bacterial genetic determinants, we sequenced the whole genome of Wolbachia wAlbB strain, a commensal obligate intracellular of the tiger mosquito Aedes albopictus.}, }
@article {pmid22404397, year = {2012}, author = {Olds, BP and Coates, BS and Steele, LD and Sun, W and Agunbiade, TA and Yoon, KS and Strycharz, JP and Lee, SH and Paige, KN and Clark, JM and Pittendrigh, BR}, title = {Comparison of the transcriptional profiles of head and body lice.}, journal = {Insect molecular biology}, volume = {21}, number = {2}, pages = {257-268}, doi = {10.1111/j.1365-2583.2012.01132.x}, pmid = {22404397}, issn = {1365-2583}, support = {1 R56 AI081933-01A2/AI/NIAID NIH HHS/United States ; 5 R01 AI 045062-06/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Exons ; Expressed Sequence Tags ; Female ; Gene Expression Profiling ; Humans ; Pediculus/genetics/*metabolism ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Transcriptome ; }, abstract = {Head and body lice are both blood-feeding parasites of humans although only the body louse is a potent disease vector. In spite of numerous morphological and life history differences, head and body lice have recently been hypothesized to be ecotypes of the same species. We took a comparative genomics approach to measure nucleotide diversity by comparing expressed sequence tag data sets from head and body lice. A total of 10 771 body louse and 10 770 head louse transcripts were predicted from a combined assembly of Roche 454 and Illumina sequenced cDNAs from whole body tissues collected at all life stages and during pesticide exposure and bacterial infection treatments. Illumina reads mapped to the 10 775 draft body louse gene models from the whole genome assembly predicted nine presence/absence differences, but PCR confirmation resulted in a single gene difference. Read per million base pair estimates indicated that 14 genes showed significant differential expression between head and body lice under our treatment conditions. One novel microRNA was predicted in both lice species and 99% of the 544 transcripts from Candidatus riesia indicate that they share the same endosymbiont. Overall, few differences exist, which supports the hypothesis that these two organisms are ecotypes of the same species.}, }
@article {pmid22404179, year = {2012}, author = {Lemaire, B and Lachenaud, O and Persson, C and Smets, E and Dessein, S}, title = {Screening for leaf-associated endophytes in the genus Psychotria (Rubiaceae).}, journal = {FEMS microbiology ecology}, volume = {81}, number = {2}, pages = {364-372}, doi = {10.1111/j.1574-6941.2012.01356.x}, pmid = {22404179}, issn = {1574-6941}, mesh = {Biological Evolution ; Burkholderia/classification/*genetics/isolation &amp; purification ; DNA, Bacterial/genetics ; Endophytes/classification/*genetics/isolation &amp; purification ; *Phylogeny ; Plant Leaves/*microbiology ; Psychotria/*microbiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Burkholderia endophytes were identified within the leaves of non-nodulated members of the genus Psychotria. In contrast to leaf-nodulated Psychotria species, which are known to accommodate their endosymbionts into specialized endosymbiont-housing structures, non-nodulated species lack bacterial leaf nodules and harbor endosymbionts intercellularly between mesophyll cells. Based on molecular data (rps16, trnG, and trnLF), the phylogenetic reconstruction of the host plants revealed a separate origin of leaf-nodulated and non-nodulated Psychotria species. Despite a distinct phylogenetic position of the two host clades, the endophytes of the non-nodulated plants were not placed into a single monophyletic group but were found to be closely related to the leaf-nodulated endosymbionts. The observation of genetically similar endophytes in both nodulated and non-nodulated Psychotria lineages suggests that the host plant is playing a crucial role in the induction of leaf nodule formation. Moreover, the concentration of endosymbionts into specialized leaf nodules may be considered as a more derived evolutionary adaptation of the host plant, serving as an interface structure to facilitate metabolic exchange between plant and endosymbiont.}, }
@article {pmid22403688, year = {2012}, author = {Wang, L and Zhou, C and He, Z and Wang, ZG and Wang, JL and Wang, YF}, title = {Wolbachia infection decreased the resistance of Drosophila to lead.}, journal = {PloS one}, volume = {7}, number = {3}, pages = {e32643}, pmid = {22403688}, issn = {1932-6203}, mesh = {Animals ; Drosophila melanogaster/*drug effects/immunology/*microbiology/physiology ; *Drug Resistance ; Environmental Pollutants/*toxicity ; Female ; Food Contamination ; Gram-Negative Bacterial Infections/genetics/*immunology/metabolism ; Host-Pathogen Interactions ; Lead/*toxicity ; Longevity/drug effects ; Male ; Malondialdehyde/metabolism ; Oxidative Stress/drug effects ; Superoxide Dismutase/metabolism ; Survival Analysis ; Wolbachia/*pathogenicity/physiology ; }, abstract = {BACKGROUND: The heavy metal lead has been shown to be associated with a genotoxic risk. Drosophila melanogaster is a model organism commonly utilized in genetic toxicology testing. The endosymbionts--Wolbachia are now very common in both wild populations and laboratory stocks of Drosophila. Wolbachia may induce resistance to pathogenic viruses, filarial nematodes and Plasmodium in fruit fly and mosquito hosts. However the effect of Wolbachia infection on the resistance of their hosts to heavy metal is unknown.<br><br>Manipulating the lead content in the diet of Drosophila melanogaster, we found that lead consumption had no different effects on developmental time between Wolbachia-infected (Dmel wMel) and -uninfected (Dmel T) flies. While in Pb-contaminated medium, significantly reduced amount of pupae and adults of Dmel wMel were emerged, and Dmel wMel adults had significantly shorter longevity than that of Dmel T flies. Lead infusion in diet resulted in significantly decreased superoxide dismutase (SOD) activity in Dmel T flies (P<0.05), but not in Dmel wMel flies. Correspondingly, lead cultures induced a 10.8 fold increase in malonaldehyde (MDA) contents in Dmel T larvae (P<0.05). While in Dmel wMel larvae, it resulted in only a 1.3 fold increase. By quantitative RT-PCR, we showed that lead infused medium caused significantly increased expression level of relish and CecA2 genes in Dmel T flies (P<0.01). Lead cultures did not change dramatically the expression of these genes in Dmel wMel flies.<br><br>CONCLUSIONS/SIGNIFICANCE: These results suggest that Wolbachia infection decreased the resistance of Drosophila to lead likely by limiting the production of peroxides resulted from lead, thus being unable to activate the immunological pathway in the host to prevent them from lead damage. This represents a novel Wolbachia-host interaction and provides information that researchers working on Drosophila toxicology should take in consideration the presence of Wolbachia in the stocks they are analyzing.}, }
@article {pmid22392278, year = {2012}, author = {Palayam, M and Lakshminarayanan, K and Radhakrishnan, M and Krishnaswamy, G}, title = {Preliminary analysis to target pyruvate phosphate dikinase from wolbachia endosymbiont of Brugia malayi for designing anti-filarial agents.}, journal = {Interdisciplinary sciences, computational life sciences}, volume = {4}, number = {1}, pages = {74-82}, doi = {10.1007/s12539-011-0109-2}, pmid = {22392278}, issn = {1867-1462}, mesh = {Algorithms ; Amino Acid Sequence ; Amino Acids/metabolism ; Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*genetics/metabolism ; *Brugia malayi ; DNA, Bacterial ; Databases, Factual ; *Drug Design ; Filariasis/*microbiology ; Genome, Bacterial ; Gluconeogenesis/genetics ; Glycolysis/genetics ; Models, Molecular ; Molecular Sequence Data ; Pyruvate, Orthophosphate Dikinase/*genetics/metabolism ; Sequence Homology ; Signal Transduction/genetics ; Symbiosis ; Wolbachia/enzymology/*genetics ; }, abstract = {Filariasis causing nematode Brugia malayi is shown to harbor wolbachia bacteria as symbionts. The sequenced genome of the wolbachia endosymbiont from B.malayi (wBm) offers an unprecedented opportunity to identify new wolbachia drug targets. Genome analysis of the glycolytic/gluconeogenic pathway has revealed that wBm lacks pyruvate kinase (PK) and may instead utilize the enzyme pyruvate phosphate dikinase (PPDK; ATP: pyruvate, orthophosphate phosphotransferase, EC 2.7.9.1). PPDK catalyses the reversible conversion of AMP, PPi and phosphoenolpyruvate into ATP, Pi and pyruvate. Most organisms including mammals exclusively possess PK. Therefore the absence of PPDK in mammals makes this enzyme as attractive wolbachia drug target. In the present study we have modeled the three dimensional structure of wBm PPDK. The template with 50% identity and 67% similarity in amino acid sequence was employed for homology-modeling approach. The putative active site consists of His476, Arg360, Glu358, Asp344, Arg112, Lys43 and Glu346 was selected as site of interest for designing suitable inhibitor molecules. Docking studies were carried out using induced fit algorithms with OPLS force field of Schrödinger's Glide. The lead molecules which inhibit the PPDK activity are taken from the small molecule library (Pubchem database) and the interaction analysis showed that these compounds may inhibit the function of PPDK in wBm.}, }
@article {pmid22383972, year = {2012}, author = {Pan, H and Li, X and Ge, D and Wang, S and Wu, Q and Xie, W and Jiao, X and Chu, D and Liu, B and Xu, B and Zhang, Y}, title = {Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci.}, journal = {PloS one}, volume = {7}, number = {2}, pages = {e30760}, pmid = {22383972}, issn = {1932-6203}, mesh = {Animals ; Bacteroidetes/*metabolism ; China ; DNA Primers/genetics ; Genetic Variation ; Geography ; Hemiptera/metabolism/*microbiology ; Insecta ; Models, Genetic ; Polymerase Chain Reaction/methods ; Population Dynamics ; Rickettsia/*metabolism ; Species Specificity ; Symbiosis ; Wolbachia/*metabolism ; }, abstract = {While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae) harbors the primary symbiont (P-symbiont) Portiera, the infection frequencies of the six secondary symbionts (S-symbionts) including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes) field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH), Rickettsia + Cardinium (RC), Hamiltonella + Cardinium (HC) and Rickettsia + Hamiltonella + Cardinium (RHC) varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci.}, }
@article {pmid22380432, year = {2012}, author = {Unckless, RL and Jaenike, J}, title = {Maintenance of a male-killing Wolbachia in Drosophila innubila by male-killing dependent and male-killing independent mechanisms.}, journal = {Evolution; international journal of organic evolution}, volume = {66}, number = {3}, pages = {678-689}, doi = {10.1111/j.1558-5646.2011.01485.x}, pmid = {22380432}, issn = {1558-5646}, mesh = {Animals ; Disease Transmission, Infectious ; Drosophila/genetics/growth &amp; development/*microbiology ; Female ; Fertility ; *Host-Pathogen Interactions ; Inbreeding ; Larva ; Male ; Population Density ; Wings, Animal/growth &amp; development ; Wolbachia/*physiology ; }, abstract = {Many maternally inherited endosymbionts manipulate their host's reproduction in various ways to enhance their own fitness. One such mechanism is male killing (MK), in which sons of infected mothers are killed by the endosymbiont during development. Several hypotheses have been proposed to explain the advantages of MK, including resource reallocation from sons to daughters of infected females, avoidance of inbreeding by infected females, and, if transmission is not purely maternal, the facilitation of horizontal transmission to uninfected females. We tested these hypotheses in Drosophila innubila, a mycophagous species infected with MK Wolbachia. There was no evidence of horizontal transmission in the wild and no evidence Wolbachia reduced levels of inbreeding. Resource reallocation does appear to be operative, as Wolbachia-infected females are slightly larger, on average, than uninfected females, although the selective advantage of larger size is insufficient to account for the frequency of infection in natural populations. Wolbachia-infected females from the wild-although not those from the laboratory-were more fecund than uninfected females. Experimental studies revealed that Wolbachia can boost the fecundity of nutrient-deprived flies and reduce the adverse effect of RNA virus infection. Thus, this MK endosymbiont can provide direct, MK-independent fitness benefits to infected female hosts in addition to possible benefits mediated via MK.}, }
@article {pmid22376198, year = {2012}, author = {Machtelinckx, T and Van Leeuwen, T and Van De Wiele, T and Boon, N and De Vos, WH and Sanchez, JA and Nannini, M and Gheysen, G and De Clercq, P}, title = {Microbial community of predatory bugs of the genus Macrolophus (Hemiptera: Miridae).}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S9}, pmid = {22376198}, issn = {1471-2180}, mesh = {Animals ; Female ; Gene Transfer, Horizontal ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Male ; Microbiota ; Ovary/microbiology ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis/genetics ; Rickettsia/*classification/genetics/*isolation &amp; purification ; Sequence Analysis, RNA/methods ; Wolbachia/*isolation &amp; purification ; }, abstract = {BACKGROUND: The predatory mirids of the genus Macrolophus are key natural enemies of various economically important agricultural pests. Both M. caliginosus and M. pygmaeus are commercially available for the augmentative biological control of arthropod pests in European greenhouses. The latter species is known to be infected with Wolbachia -inducing cytoplasmic incompatibility in its host- but the presence of other endosymbionts has not been demonstrated. In the present study, the microbial diversity was examined in various populations of M. caliginosus and M. pygmaeus by 16S rRNA sequencing and denaturing gradient gel electrophoresis.<br><br>RESULTS: Besides Wolbachia, a co-infection of 2 Rickettsia species was detected in all M. pygmaeus populations. Based on a concatenated alignment of the 16S rRNA gene, the gltA gene and the coxA gene, the first is phylogenetically related to Rickettsia bellii, whereas the other is closely related to Rickettsia limoniae. All M. caliginosus populations were infected with the same Wolbachia and limoniae-like Rickettsia strain as M. pygmaeus, but did not harbour the bellii-like Rickettsia strain. Interestingly, individuals with a single infection were not found. A PCR assay on the ovaries of M. pygmaeus and M. caliginosus indicated that all endosymbionts are vertically transmitted. The presence of Wolbachia and Rickettsia in oocytes was confirmed by a fluorescence in situ hybridisation. A bio-assay comparing an infected and an uninfected M. pygmaeus population suggested that the endosymbionts had minor effects on nymphal development of their insect host and did not influence its fecundity.<br><br>CONCLUSION: Two species of the palaearctic mirid genus Macrolophus are infected with multiple endosymbionts, including Wolbachia and Rickettsia. Independent of the origin, all tested populations of both M. pygmaeus and M. caliginosus were infected with three and two endosymbionts, respectively. There was no indication that infection with endosymbiotic bacteria had a fitness cost in terms of development and fecundity of the predators.}, }
@article {pmid22376125, year = {2012}, author = {Hirsch, J and Strohmeier, S and Pfannkuchen, M and Reineke, A}, title = {Assessment of bacterial endosymbiont diversity in Otiorhynchus spp. (Coleoptera: Curculionidae) larvae using a multitag 454 pyrosequencing approach.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S6}, pmid = {22376125}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; Coleoptera/*embryology/*microbiology ; DNA, Bacterial/analysis ; Larva/microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/analysis/genetics ; Rickettsia/classification/isolation &amp; purification ; Sequence Analysis, DNA/*methods ; Symbiosis ; }, abstract = {BACKGROUND: Weevils of the genus Otiorhynchus are regarded as devastating pests in a wide variety of horticultural crops worldwide. So far, little is known on the presence of endosymbionts in Otiorhynchus spp.. Investigation of endosymbiosis in this genus may help to understand the evolution of different reproductive strategies in these weevils (parthenogenesis or sexual reproduction), host-symbiont interactions, and may provide a future basis for novel pest management strategy development. Here, we used a multitag 454 pyrosequencing approach to assess the bacterial endosymbiont diversity in larvae of four economically important Otiorhynchus species.<br><br>RESULTS: High-throughput tag-encoded FLX amplicon pyrosequencing of a bacterial 16S rDNA fragment was used to characterise bacterial communities associated with different Otiorhynchus spp. larvae. By sequencing a total of ~48,000 PCR amplicons, we identified 49 different operational taxonomic units (OTUs) as bacterial endosymbionts in the four studied Otiorhynchus species. More than 90% of all sequence reads belonged either to the genus Rickettsia or showed homology to the phylogenetic group of "Candidatus Blochmannia" and to endosymbionts of the lice Pedicinus obtusus and P. badii. By using specific primers for the genera Rickettsia and "Candidatus Blochmannia", we identified a new phylogenetic clade of Rickettsia as well as "Candidatus Nardonella" endosymbionts in Otiorhynchus spp. which are closely related to "Candidatus Blochmannia" bacteria.<br><br>CONCLUSIONS: Here, we used multitag 454 pyrosequencing for assessment of insect endosymbiotic communities in weevils. As 454 pyrosequencing generates only quite short sequences, results of such studies can be regarded as a first step towards identifying respective endosymbiotic species in insects. In the second step of our study, we analysed sequences of specific gene regions for a more detailed phylogeny of selected endosymbiont genera. As a result we identified the presence of Rickettsia and "Candidatus Nardonella" endosymbionts in Otiorhynchus spp.. This knowledge is an important step in exploring bacteria-insect associations for potential use in insect pest control.}, }
@article {pmid22376077, year = {2012}, author = {González-Domenech, CM and Belda, E and Patiño-Navarrete, R and Moya, A and Peretó, J and Latorre, A}, title = {Metabolic stasis in an ancient symbiosis: genome-scale metabolic networks from two Blattabacterium cuenoti strains, primary endosymbionts of cockroaches.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S5}, pmid = {22376077}, issn = {1471-2180}, mesh = {Animals ; Bacteroidetes/classification/genetics/*physiology ; *Citric Acid Cycle ; Cockroaches/*microbiology/physiology ; Genome, Bacterial ; Metabolic Networks and Pathways ; Models, Genetic ; Symbiosis ; }, abstract = {BACKGROUND: Cockroaches are terrestrial insects that strikingly eliminate waste nitrogen as ammonia instead of uric acid. Blattabacterium cuenoti (Mercier 1906) strains Bge and Pam are the obligate primary endosymbionts of the cockroaches Blattella germanica and Periplaneta americana, respectively. The genomes of both bacterial endosymbionts have recently been sequenced, making possible a genome-scale constraint-based reconstruction of their metabolic networks. The mathematical expression of a metabolic network and the subsequent quantitative studies of phenotypic features by Flux Balance Analysis (FBA) represent an efficient functional approach to these uncultivable bacteria.<br><br>RESULTS: We report the metabolic models of Blattabacterium strains Bge (iCG238) and Pam (iCG230), comprising 296 and 289 biochemical reactions, associated with 238 and 230 genes, and 364 and 358 metabolites, respectively. Both models reflect both the striking similarities and the singularities of these microorganisms. FBA was used to analyze the properties, potential and limits of the models, assuming some environmental constraints such as aerobic conditions and the net production of ammonia from these bacterial systems, as has been experimentally observed. In addition, in silico simulations with the iCG238 model have enabled a set of carbon and nitrogen sources to be defined, which would also support a viable phenotype in terms of biomass production in the strain Pam, which lacks the first three steps of the tricarboxylic acid cycle. FBA reveals a metabolic condition that renders these enzymatic steps dispensable, thus offering a possible evolutionary explanation for their elimination. We also confirm, by computational simulations, the fragility of the metabolic networks and their host dependence.<br><br>CONCLUSIONS: The minimized Blattabacterium metabolic networks are surprisingly similar in strains Bge and Pam, after 140 million years of evolution of these endosymbionts in separate cockroach lineages. FBA performed on the reconstructed networks from the two bacteria helps to refine the functional analysis of the genomes enabling us to postulate how slightly different host metabolic contexts drove their parallel evolution.}, }
@article {pmid22375935, year = {2012}, author = {Zhukova, MV and Kiseleva, E}, title = {The virulent Wolbachia strain wMelPop increases the frequency of apoptosis in the female germline cells of Drosophila melanogaster.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S15}, pmid = {22375935}, issn = {1471-2180}, mesh = {Animals ; Apoptosis ; Drosophila melanogaster/*microbiology/physiology/ultrastructure ; Female ; Germ Cells/microbiology/*physiology/ultrastructure ; Microscopy, Fluorescence ; Wolbachia/*pathogenicity ; }, abstract = {BACKGROUND: Wolbachia are bacterial endosymbionts of many arthropod species in which they manipulate reproductive functions. The distribution of these bacteria in the Drosophila ovarian cells at different stages of oogenesis has been amply described. The pathways along which Wolbachia influences Drosophila oogenesis have been, so far, little studied. It is known that Wolbachia are abundant in the somatic stem cell niche of the Drosophila germarium. A checkpoint, where programmed cell death, or apoptosis, can occur, is located in region 2a/2b of the germarium, which comprises niche cells. Here we address the question whether or not the presence of Wolbachia in germarium cells can affect the frequency of cyst apoptosis in the checkpoint.<br><br>RESULTS: Our current fluorescent microscopic observations showed that the wMel and wMelPop strains had different effects on female germline cells of D. melanogaster. The Wolbachia strain wMel did not affect the frequency of apoptosis in cells of the germarium. The presence of the Wolbachia strain wMelPop in the D. melanogasterw1118 ovaries increased the number of germaria where cells underwent apoptosis in the checkpoint. Based on the appearance in the electron microscope, there was no difference in morphological features of apoptotic cystocytes between Wolbachia-infected and uninfected flies. Bacteria with normal ultrastructure and large numbers of degenerating bacteria were found in the dying cyst cells.<br><br>CONCLUSIONS: Our current study demonstrated that the Wolbachia strain wMelPop affects the egg chamber formation in the D. melanogaster ovaries. This led to an increase in the number of germaria containing apoptotic cells. It is suggested that Wolbachia can adversely interfere either with the cystocyte differentiation into the oocyte or with the division of somatic stem cells giving rise to follicle cells and, as a consequence, to improper ratio of germline cells to follicle cells and, ultimately, to apoptosis of cysts. There was no similar adverse effect in D. melanogaster Canton S infected with the Wolbachia strain wMel. This was taken to mean that the observed increase in frequency of apoptosis was not the general effect of Wolbachia on germline cells of D. melanogaster, it was rather induced by the virulent Wolbachia strain wMelPop.}, }
@article {pmid22375912, year = {2012}, author = {Vigneron, A and Charif, D and Vincent-Monégat, C and Vallier, A and Gavory, F and Wincker, P and Heddi, A}, title = {Host gene response to endosymbiont and pathogen in the cereal weevil Sitophilus oryzae.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S14}, pmid = {22375912}, issn = {1471-2180}, mesh = {Animals ; Bacterial Proteins/genetics ; Gammaproteobacteria/*physiology ; Gene Expression Regulation ; Gene Library ; Genomics/*methods ; Host Specificity ; Host-Pathogen Interactions ; Insect Proteins/*genetics ; Larva/microbiology ; Microbiota ; Molecular Sequence Data ; Sequence Analysis, DNA ; Symbiosis ; Weevils/embryology/*genetics/microbiology/physiology ; }, abstract = {BACKGROUND: Insects thriving on nutritionally poor habitats have integrated mutualistic intracellular symbiotic bacteria (endosymbionts) in a bacteria-bearing tissue (the bacteriome) that isolates the endosymbionts and protects them against a host systemic immune response. Whilst the metabolic and physiological features of long-term insect associations have been investigated in detail over the past decades, cellular and immune regulations that determine the host response to endosymbionts and pathogens have attracted interest more recently.<br><br>RESULTS: To investigate bacteriome cellular specificities and weevil immune responses to bacteria, we have constructed and sequenced 7 cDNA libraries from Sitophilus oryzae whole larvae and bacteriomes. Bioinformatic analysis of 26,886 ESTs led to the generation of 8,941 weevil unigenes. Based on in silico analysis and on the examination of genes involved in the cellular pathways of potential interest to intracellular symbiosis (i.e. cell growth and apoptosis, autophagy, immunity), we have selected and analyzed 29 genes using qRT-PCR, taking into consideration bacteriome specificity and symbiosis impact on the host response to pathogens. We show that the bacteriome tissue accumulates transcripts from genes involved in cellular development and survival, such as the apoptotic inhibitors iap2 and iap3, and endosomal fusion and trafficking, such as Rab7, Hrs, and SNARE. As regards our investigation into immunity, we first strengthen the bacteriome immunomodulation previously reported in S. zeamais. We show that the sarcotoxin, the c-type lysozyme, and the wpgrp2 genes are downregulated in the S. oryzae bacteriome, when compared to aposymbiotic insects and insects challenged with E. coli. Secondly, transcript level comparison between symbiotic and aposymbiotic larvae provides evidence that the immune systemic response to pathogens is decreased in symbiotic insects, as shown by the relatively high expression of wpgrp2, wpgrp3, coleoptericin-B, diptericin, and sarcotoxin genes in aposymbiotic insects.<br><br>CONCLUSIONS: Library sequencing significantly increased the number of unigenes, allowing for improved functional and genetic investigations in the cereal weevil S. oryzae. Transcriptomic analyses support selective and local immune gene expression in the bacteriome tissue and uncover cellular pathways that are of potential interest to bacteriocyte survival and homeostasis. Bacterial challenge experiments have revealed that the systemic immune response would be less induced in a symbiotic insect, thus highlighting new perspectives on host immunity in long-term invertebrate co-evolutionary associations.}, }
@article {pmid22375894, year = {2012}, author = {Ros, VI and Fleming, VM and Feil, EJ and Breeuwer, JA}, title = {Diversity and recombination in Wolbachia and Cardinium from Bryobia spider mites.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S13}, pmid = {22375894}, issn = {1471-2180}, mesh = {Animals ; Bacteroides/classification/*genetics ; Genes, Bacterial ; Molecular Sequence Data ; Phylogeny ; Recombination, Genetic ; Sequence Analysis, DNA ; Tetranychidae/classification/*microbiology ; Wolbachia/*classification/*genetics ; }, abstract = {BACKGROUND: Wolbachia and Cardinium are endosymbiotic bacteria infecting many arthropods and manipulating host reproduction. Although these bacteria are maternally transmitted, incongruencies between phylogenies of host and parasite suggest an additional role for occasional horizontal transmission. Consistent with this view is the strong evidence for recombination in Wolbachia, although it is less clear to what extent recombination drives diversification within single host species and genera. Furthermore, little is known concerning the population structures of other insect endosymbionts which co-infect with Wolbachia, such as Cardinium. Here, we explore Wolbachia and Cardinium strain diversity within nine spider mite species (Tetranychidae) from 38 populations, and quantify the contribution of recombination compared to point mutation in generating Wolbachia diversity.<br><br>RESULTS: We found a high level of genetic diversity for Wolbachia, with 36 unique strains detected (64 investigated mite individuals). Sequence data from four Wolbachia genes suggest that new alleles are 7.5 to 11 times more likely to be generated by recombination than point mutation. Consistent with previous reports on more diverse host samples, our data did not reveal evidence for co-evolution of Wolbachia with its host. Cardinium was less frequently found in the mites, but also showed a high level of diversity, with eight unique strains detected in 15 individuals on the basis of only two genes. A lack of congruence among host and Cardinium phylogenies was observed.<br><br>CONCLUSIONS: We found a high rate of recombination for Wolbachia strains obtained from host species of the spider mite family Tetranychidae, comparable to rates found for horizontally transmitted bacteria. This suggests frequent horizontal transmission of Wolbachia and/or frequent horizontal transfer of single genes. Our findings strengthens earlier reports of recombination for Wolbachia, and shows that high recombination rates are also present on strains from a restrictive host range. Cardinium was found co-infecting several spider mite species, and phylogenetic comparisons suggest also horizontal transmission of Cardinium among hosts.}, }
@article {pmid22375708, year = {2012}, author = {Chevalier, F and Herbinière-Gaboreau, J and Charif, D and Mitta, G and Gavory, F and Wincker, P and Grève, P and Braquart-Varnier, C and Bouchon, D}, title = {Feminizing Wolbachia: a transcriptomics approach with insights on the immune response genes in Armadillidium vulgare.}, journal = {BMC microbiology}, volume = {12 Suppl 1}, number = {Suppl 1}, pages = {S1}, pmid = {22375708}, issn = {1471-2180}, mesh = {Animals ; Expressed Sequence Tags ; Female ; Gene Expression Profiling/*methods ; Gene Expression Regulation ; Isopoda/*genetics/*immunology/microbiology/physiology ; Male ; Ovary/immunology/metabolism ; Symbiosis ; Wolbachia/immunology/*physiology ; }, abstract = {BACKGROUND: Wolbachia are vertically transmitted bacteria known to be the most widespread endosymbiont in arthropods. They induce various alterations of the reproduction of their host, including feminization of genetic males in isopod crustaceans. In the pill bug Armadillidium vulgare, the presence of Wolbachia is also associated with detrimental effects on host fertility and lifespan. Deleterious effects have been demonstrated on hemocyte density, phenoloxidase activity, and natural hemolymph septicemia, suggesting that infected individuals could have defective immune capacities. Since nothing is known about the molecular mechanisms involved in Wolbachia-A. vulgare interactions and its secondary immunocompetence modulation, we developed a transcriptomics strategy and compared A. vulgare gene expression between Wolbachia-infected animals (i.e., "symbiotic" animals) and uninfected ones (i.e., "asymbiotic" animals) as well as between animals challenged or not challenged by a pathogenic bacteria.<br><br>RESULTS: Since very little genetic data is available on A. vulgare, we produced several EST libraries and generated a total of 28 606 ESTs. Analyses of these ESTs revealed that immune processes were over-represented in most experimental conditions (responses to a symbiont and to a pathogen). Considering canonical crustacean immune pathways, these genes encode antimicrobial peptides or are involved in pathogen recognition, detoxification, and autophagy. By RT-qPCR, we demonstrated a general trend towards gene under-expression in symbiotic whole animals and ovaries whereas the same gene set tends to be over-expressed in symbiotic immune tissues.<br><br>CONCLUSION: This study allowed us to generate the first reference transcriptome ever obtained in the Isopoda group and to identify genes involved in the major known crustacean immune pathways encompassing cellular and humoral responses. Expression of immune-related genes revealed a modulation of host immunity when females are infected by Wolbachia, including in ovaries, the crucial tissue for the Wolbachia route of transmission.}, }
@article {pmid22371600, year = {2012}, author = {Nowack, EC and Grossman, AR}, title = {Trafficking of protein into the recently established photosynthetic organelles of Paulinella chromatophora.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {109}, number = {14}, pages = {5340-5345}, pmid = {22371600}, issn = {1091-6490}, mesh = {Amoeba/*metabolism ; Animals ; Electrophoresis, Polyacrylamide Gel ; Microscopy, Immunoelectron ; Organelles/*metabolism ; *Photosynthesis ; Protein Transport ; }, abstract = {Endosymbiotic acquisition of bacteria by a protist, with subsequent evolution of the bacteria into mitochondria and plastids, had a transformative impact on eukaryotic biology. Reconstructing events that created a stable association between endosymbiont and host during the process of organellogenesis--including establishment of regulated protein import into nascent organelles--is difficult because they date back more than 1 billion years. The amoeba Paulinella chromatophora contains nascent photosynthetic organelles of more recent evolutionary origin (∼60 Mya) termed chromatophores (CRs). After the initial endosymbiotic event, the CR genome was reduced to approximately 30% of its presumed original size and more than 30 expressed genes were transferred from the CR to the amoebal nuclear genome. Three transferred genes--psaE, psaK1, and psaK2--encode subunits of photosystem I. Here we report biochemical evidence that PsaE, PsaK1, and PsaK2 are synthesized in the amoeba cytoplasm and traffic into CRs, where they assemble with CR-encoded subunits into photosystem I complexes. Additionally, our data suggest that proteins routed to CRs pass through the Golgi apparatus. Whereas genome reduction and transfer of genes from bacterial to host genome have been reported to occur in other obligate bacterial endosymbioses, this report outlines the import of proteins encoded by such transferred genes into the compartment derived from the bacterial endosymbiont. Our study showcases P. chromatophora as an exceptional model in which to study early events in organellogenesis, and suggests that protein import into bacterial endosymbionts might be a phenomenon much more widespread than currently assumed.}, }
@article {pmid22364314, year = {2012}, author = {Toenshoff, ER and Gruber, D and Horn, M}, title = {Co-evolution and symbiont replacement shaped the symbiosis between adelgids (Hemiptera: Adelgidae) and their bacterial symbionts.}, journal = {Environmental microbiology}, volume = {14}, number = {5}, pages = {1284-1295}, doi = {10.1111/j.1462-2920.2012.02712.x}, pmid = {22364314}, issn = {1462-2920}, support = {P 22533/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Betaproteobacteria/*classification/genetics/*physiology/ultrastructure ; Female ; Gammaproteobacteria/*classification/genetics/*physiology/ultrastructure ; Hemiptera/genetics/*microbiology/ultrastructure ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis/genetics ; }, abstract = {The Adelgidae (Insecta: Hemiptera), a small group of insects, are known as severe pests on various conifers of the northern hemisphere. Despite of this, little is known about their bacteriocyte-associated endosymbionts, which are generally important for the biology and ecology of plant sap-sucking insects. Here, we investigated the adelgid species complexes Adelges laricis/tardus, Adelges abietis/viridis and Adelges cooleyi/coweni, identified based on their coI and ef1alpha genes. Each of these insect groups harboured two phylogenetically different bacteriocyte-associated symbionts belonging to the Betaproteobacteria and the Gammaproteobacteria, respectively, as inferred from phylogenetic analyses of 16S rRNA gene sequences and demonstrated by fluorescence in situ hybridization. The betaproteobacterial symbionts of all three adelgid complexes ('Candidatus Vallotia tarda', 'Candidatus Vallotia virida' and 'Candidatus Vallotia cooleyia') share a common ancestor and show a phylogeny congruent with that of their respective hosts. Similarly, there is evidence for co-evolution between the gammaproteobacterial symbionts ('Candidatus Profftia tarda', 'Candidatus Profftia virida') and A. laricis/tardus and A. abietis/viridis. In contrast, the gammaproteobacterial symbiont of A. cooleyi/coweni ('Candidatus Gillettellia cooleyia') is different from that of the other two adelgids but shows a moderate relationship to the symbiont 'Candidatus Ecksteinia adelgidicola' of A. nordmannianae/piceae. All symbionts were present in all adelgid populations and life stages analysed, suggesting vertical transmission from mother to offspring. In sharp contrast to their sister group, the aphids, adelgids do not consistently contain a single obligate (primary) symbiont but have acquired phylogenetically different bacterial symbionts during their evolution, which included multiple infections and symbiont replacement.}, }
@article {pmid22364271, year = {2012}, author = {Oliver, KM and Noge, K and Huang, EM and Campos, JM and Becerra, JX and Hunter, MS}, title = {Parasitic wasp responses to symbiont-based defense in aphids.}, journal = {BMC biology}, volume = {10}, number = {}, pages = {11}, pmid = {22364271}, issn = {1741-7007}, mesh = {Animals ; Aphids/*microbiology/*parasitology/physiology/virology ; Bacteriophages/genetics/*physiology ; Enterobacteriaceae/*physiology/virology ; Gas Chromatography-Mass Spectrometry ; *Oviposition ; Pheromones/pharmacology ; Sesquiterpenes/pharmacology ; Symbiosis ; Wasps/drug effects/*physiology ; }, abstract = {BACKGROUND: Recent findings indicate that several insect lineages receive protection against particular natural enemies through infection with heritable symbionts, but little is yet known about whether enemies are able to discriminate and respond to symbiont-based defense. The pea aphid, Acyrthosiphon pisum, receives protection against the parasitic wasp, Aphidius ervi, when infected with the bacterial symbiont Hamiltonella defensa and its associated bacteriophage APSE (Acyrthosiphon pisum secondary endosymbiont). Internally developing parasitoid wasps, such as A. ervi, use maternal and embryonic factors to create an environment suitable for developing wasps. If more than one parasitoid egg is deposited into a single aphid host (superparasitism), then additional complements of these factors may contribute to the successful development of the single parasitoid that emerges.<br><br>RESULTS: We performed experiments to determine if superparasitism is a tactic allowing wasps to overcome symbiont-mediated defense. We found that the deposition of two eggs into symbiont-protected aphids significantly increased rates of successful parasitism relative to singly parasitized aphids. We then conducted behavioral assays to determine whether A. ervi selectively superparasitizes H. defensa-infected aphids. In choice tests, we found that A. ervi tends to deposit a single egg in uninfected aphids, but two or more eggs in H. defensa-infected aphids, indicating that oviposition choices may be largely determined by infection status. Finally, we identified differences in the quantity of the trans-&#x3b2;-farnesene, the major component of aphid alarm pheromone, between H. defensa-infected and uninfected aphids, which may form the basis for discrimination.<br><br>CONCLUSIONS: Here we show that the parasitic wasp A. ervi discriminates among symbiont-infected and uninfected aphids, and changes its oviposition behavior in a way that increases the likelihood of overcoming symbiont-based defense. More generally, our results indicate that natural enemies are not passive victims of defensive symbionts, and that an evolutionary arms race between A. pisum and the parasitoid A. ervi may be mediated by a bacterial symbiosis.}, }
@article {pmid22363720, year = {2012}, author = {Kawafune, K and Hongoh, Y and Hamaji, T and Nozaki, H}, title = {Molecular identification of rickettsial endosymbionts in the non-phagotrophic volvocalean green algae.}, journal = {PloS one}, volume = {7}, number = {2}, pages = {e31749}, pmid = {22363720}, issn = {1932-6203}, mesh = {Base Sequence ; Cell Size ; Chlorophyta/cytology/growth &amp; development/*microbiology ; Host-Pathogen Interactions ; Humans ; In Situ Hybridization, Fluorescence ; Indoles/metabolism ; Molecular Sequence Data ; Nucleotides/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae/*genetics ; Species Specificity ; Staining and Labeling ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: The order Rickettsiales comprises gram-negative obligate intracellular bacteria (also called rickettsias) that are mainly associated with arthropod hosts. This group is medically important because it contains human-pathogenic species that cause dangerous diseases. Until now, there has been no report of non-phagotrophic photosynthetic eukaryotes, such as green plants, harboring rickettsias.<br><br>We examined the bacterial endosymbionts of two freshwater volvocalean green algae: unicellular Carteria cerasiformis and colonial Pleodorina japonica. Epifluorescence microscopy using 4'-6-deamidino-2-phenylindole staining revealed the presence of endosymbionts in all C. cerasiformis NIES-425 cells, and demonstrated a positive correlation between host cell size and the number of endosymbionts. Strains both containing and lacking endosymbionts of C. cerasiformis (NIES-425 and NIES-424) showed a >10-fold increase in cell number and typical sigmoid growth curves over 192 h. A phylogenetic analysis of 16 S ribosomal (r)RNA gene sequences from the endosymbionts of C. cerasiformis and P. japonica demonstrated that they formed a robust clade (hydra group) with endosymbionts of various non-arthropod hosts within the family Rickettsiaceae. There were significantly fewer differences in the 16 S rRNA sequences of the rickettsiacean endosymbionts between C. cerasiformis and P. japonica than in the chloroplast 16 S rRNA or 18 S rRNA of the host volvocalean cells. Fluorescence in situ hybridization demonstrated the existence of the rickettsiacean endosymbionts in the cytoplasm of two volvocalean species.<br><br>CONCLUSIONS/SIGNIFICANCE: The rickettsiacean endosymbionts are likely not harmful to their volvocalean hosts and may have been recently transmitted from other non-arthropod organisms. Because rickettsias are the closest relatives of mitochondria, incipient stages of mitochondrial endosymbiosis may be deduced using both strains with and without C. cerasiformis endosymbionts.}, }
@article {pmid22361857, year = {2012}, author = {Rosic, NN}, title = {Phylogenetic analysis of genes involved in mycosporine-like amino acid biosynthesis in symbiotic dinoflagellates.}, journal = {Applied microbiology and biotechnology}, volume = {94}, number = {1}, pages = {29-37}, doi = {10.1007/s00253-012-3925-3}, pmid = {22361857}, issn = {1432-0614}, mesh = {Amino Acids/*biosynthesis ; Animals ; Anthozoa/*physiology ; Biosynthetic Pathways ; Dinoflagellida/*classification/genetics/isolation &amp; purification/*physiology ; *Phylogeny ; Protozoan Proteins/genetics/metabolism ; *Symbiosis ; }, abstract = {Mycosporine-like amino acids (MAAs) are multifunctional secondary metabolites involved in photoprotection in many marine organisms. As well as having broad ultraviolet (UV) absorption spectra (310-362 nm), these biological sunscreens are also involved in the prevention of oxidative stress. More than 20 different MAAs have been discovered so far, characterized by distinctive chemical structures and a broad ecological distribution. Additionally, UV-screening MAA metabolites have been investigated and used in biotechnology and cosmetics. The biosynthesis of MAAs has been suggested to occur via either the shikimate or pentose phosphate pathways. Despite their wide distribution in marine and freshwater species and also the commercial application in cosmetic products, there are still a number of uncertainties regarding the genetic, biochemical, and evolutionary origin of MAAs. Here, using a transcriptome-mining approach, we identify the gene counterparts from the shikimate or pentose phosphate pathway involved in MAA biosynthesis within the sequences of the reef-building coral symbiotic dinoflagellates (genus Symbiodinium). We also report the highly similar sequences of genes from the proposed MAA biosynthetic pathway involved in the metabolism of 4-deoxygadusol (direct MAA precursor) in various Symbiodinium strains confirming their algal origin and conserved nature. Finally, we reveal the separate identity of two O-methyltransferase genes, possibly involved in MAA biosynthesis, as well as nonribosomal peptide synthetase and adenosine triphosphate grasp homologs in symbiotic dinoflagellates. This study provides a biochemical and phylogenetic overview of the genes from the proposed MAA biosynthetic pathway with a focus on coral endosymbionts.}, }
@article {pmid22356923, year = {2012}, author = {Schrallhammer, M and Galati, S and Altenbuchner, J and Schweikert, M and Görtz, HD and Petroni, G}, title = {Tracing the role of R-bodies in the killer trait: absence of toxicity of R-body producing recombinant E. coli on paramecia.}, journal = {European journal of protistology}, volume = {48}, number = {4}, pages = {290-296}, doi = {10.1016/j.ejop.2012.01.008}, pmid = {22356923}, issn = {1618-0429}, mesh = {Alphaproteobacteria/genetics/*physiology/ultrastructure ; Bacterial Proteins/chemistry/genetics/metabolism/toxicity ; Escherichia coli/*genetics/ultrastructure ; Hydrogen-Ion Concentration ; Microscopy, Electron, Transmission ; Paramecium tetraurelia/*microbiology ; Recombinant Proteins/chemistry/genetics/*metabolism ; }, abstract = {R-bodies are coiled proteinaceous ribbons produced by Paramecium endosymbionts belonging to the genus Caedibacter. These intracellular bacteria confer upon their hosts a phenomenon called the killer trait. It is the ability to kill symbiont-free competitors called sensitives. The R-body is the crucial element of this process, but despite many efforts, the actual role of R-bodies in killing sensitive paramecia is still not satisfactory clarified. The open question is whether the R-body acts as transmitter for a yet unidentified toxin or whether it directly kills sensitive paramecia having intrinsic cytotoxic effects. In the present study, this problem is addressed by heterologous expression of Caedibacter taeniospiralis R-body in Escherichia coli followed by a detailed analysis of its potential intrinsic toxic effect on feeding sensitive Paramecium tetraurelia. Using this approach, we can exclude any eventual effects of additional, unidentified factors produced by C. taeniospiralis and thus observe the impact of the recombinant R-body itself. No cytotoxic effects of recombinant R-bodies were detected following this approach, strengthening the hypothesis that R-bodies act as releasing system for an unidentified C. taeniospiralis toxin.}, }
@article {pmid22351985, year = {2011}, author = {Isaza, LA and Opelt, K and Wagner, T and Mattes, E and Bieber, E and Hatley, EO and Roth, G and Sanjuán, J and Fischer, HM and Sandermann, H and Hartmann, A and Ernst, D}, title = {Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.}, journal = {Zeitschrift fur Naturforschung. C, Journal of biosciences}, volume = {66}, number = {11-12}, pages = {595-604}, doi = {10.1515/znc-2011-11-1209}, pmid = {22351985}, issn = {0939-5075}, mesh = {Base Sequence ; Bradyrhizobium/*genetics ; DNA Primers ; *Gene Transfer Techniques ; Glycine/*analogs &amp; derivatives/pharmacology ; Insecticide Resistance/*genetics ; Plants, Genetically Modified ; Polymerase Chain Reaction ; Soybeans/*genetics ; }, abstract = {A field study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR). To further assess the likelihood that the EPSPS gene may be transferred from the Roundup Ready (RR) soybean to B. japonicum, we have examined the natural transformation efficiency of B. japonicum strain 110spc4. Analyses of nodules showed the presence of the transgenic EPSPS DNA sequence. In bacteroids that were isolated from nodules of transgenic soybean plants and then cultivated in the presence of glyphosate this sequence could not be detected. This indicates that no stable horizontal gene transfer (HGT) of the EPSPS gene had occurred under field conditions. Under laboratory conditions, no natural transformation was detected in B. japonicum strain 110spc4 in the presence of various amounts of recombinant plasmid DNA. Our results indicate that no natural competence state exists in B. japonicum 110spc4. Results from field and laboratory studies indicate the lack of functional transfer of the CP4-EPSPS gene from glyphosate-tolerant soybean treated with glyphosate to root-associated B. japonicum.}, }
@article {pmid22351649, year = {2012}, author = {Weston, AJ and Dunlap, WC and Shick, JM and Klueter, A and Iglic, K and Vukelic, A and Starcevic, A and Ward, M and Wells, ML and Trick, CG and Long, PF}, title = {A profile of an endosymbiont-enriched fraction of the coral Stylophora pistillata reveals proteins relevant to microbial-host interactions.}, journal = {Molecular &amp; cellular proteomics : MCP}, volume = {11}, number = {6}, pages = {M111.015487}, pmid = {22351649}, issn = {1535-9484}, mesh = {Animals ; Anthozoa/*metabolism/microbiology/physiology ; Dinoflagellida/*metabolism/physiology ; Heat-Shock Response ; Iron/metabolism ; Manganese/metabolism ; Proteome/*metabolism ; Protozoan Proteins/*metabolism ; *Symbiosis ; Trace Elements/metabolism ; }, abstract = {This study examines the response of Symbiodinium sp. endosymbionts from the coral Stylophora pistillata to moderate levels of thermal "bleaching" stress, with and without trace metal limitation. Using quantitative high throughput proteomics, we identified 8098 MS/MS events relating to individual peptides from the endosymbiont-enriched fraction, including 109 peptides meeting stringent criteria for quantification, of which only 26 showed significant change in our experimental treatments; 12 of 26 increased expression in response to thermal stress with little difference affected by iron limitation. Surprisingly, there were no significant increases in antioxidant or heat stress proteins; those induced to higher expression were generally involved in protein biosynthesis. An outstanding exception was a massive 114-fold increase of a viral replication protein indicating that thermal stress may substantially increase viral load and thereby contribute to the etiology of coral bleaching and disease. In the absence of a sequenced genome for Symbiodinium or other photosymbiotic dinoflagellate, this proteome reveals a plethora of proteins potentially involved in microbial-host interactions. This includes photosystem proteins, DNA repair enzymes, antioxidant enzymes, metabolic redox enzymes, heat shock proteins, globin hemoproteins, proteins of nitrogen metabolism, and a wide range of viral proteins associated with these endosymbiont-enriched samples. Also present were 21 unusual peptide/protein toxins thought to originate from either microbial consorts or from contamination by coral nematocysts. Of particular interest are the proteins of apoptosis, vesicular transport, and endo/exocytosis, which are discussed in context of the cellular processes of coral bleaching. Notably, the protein complement provides evidence that, rather than being expelled by the host, stressed endosymbionts may mediate their own departure.}, }
@article {pmid22351180, year = {2012}, author = {Rasmussen, S and Lane, GA and Mace, W and Parsons, AJ and Fraser, K and Xue, H}, title = {The use of genomics and metabolomics methods to quantify fungal endosymbionts and alkaloids in grasses.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {860}, number = {}, pages = {213-226}, doi = {10.1007/978-1-61779-594-7_14}, pmid = {22351180}, issn = {1940-6029}, mesh = {Alkaloids/genetics/metabolism ; Genomics ; Lolium/*genetics/*metabolism/microbiology ; Metabolomics ; Neotyphodium/*isolation &amp; purification ; Poaceae/*genetics/*metabolism ; Symbiosis/genetics ; }, abstract = {The association of plants with endosymbiotic micro-organisms poses a particular challenge to metabolomics studies. The presence of endosymbionts can alter metabolic profiles of plant tissues by introducing non-plant metabolites such as fungal specific alkaloids, and by metabolic interactions between the two organisms. An accurate quantification of the endosymbiont and its metabolites is therefore critical for studies of interactions between the two symbionts and the environment.Here, we describe methods that allow the quantification of the ryegrass Neotyphodium lolii fungal endosymbiont and major alkaloids in its host plant Lolium perenne. Fungal concentrations were quantified in total genomic DNA (gDNA) isolated from infected plant tissues by quantitative PCR (qPCR) using primers specific for chitinase A from N. lolii. To quantify the fungal alkaloids, we describe LC-MS based methods which provide coverage of a wide range of alkaloids of the indolediterpene and ergot alkaloid classes, together with peramine.}, }
@article {pmid22335892, year = {2012}, author = {De Vooght, L and Caljon, G and Stijlemans, B and De Baetselier, P and Coosemans, M and Van den Abbeele, J}, title = {Expression and extracellular release of a functional anti-trypanosome Nanobody® in Sodalis glossinidius, a bacterial symbiont of the tsetse fly.}, journal = {Microbial cell factories}, volume = {11}, number = {}, pages = {23}, pmid = {22335892}, issn = {1475-2859}, mesh = {Animals ; Antibodies, Protozoan/*biosynthesis/genetics/immunology ; Enterobacteriaceae/*metabolism ; Gene Expression ; Glycoproteins/immunology ; Periplasm/metabolism ; Protein Sorting Signals/genetics ; Protozoan Proteins/immunology ; Recombinant Fusion Proteins/biosynthesis/genetics/immunology ; *Symbiosis ; Trypanosoma brucei brucei/metabolism ; Tsetse Flies/*microbiology ; }, abstract = {BACKGROUND: Sodalis glossinidius, a gram-negative bacterial endosymbiont of the tsetse fly, has been proposed as a potential in vivo drug delivery vehicle to control trypanosome parasite development in the fly, an approach known as paratransgenesis. Despite this interest of S. glossinidius as a paratransgenic platform organism in tsetse flies, few potential effector molecules have been identified so far and to date none of these molecules have been successfully expressed in this bacterium.<br><br>RESULTS: In this study, S. glossinidius was transformed to express a single domain antibody, (Nanobody&#xae;) Nb_An33, that efficiently targets conserved cryptic epitopes of the variant surface glycoprotein (VSG) of the parasite Trypanosoma brucei. Next, we analyzed the capability of two predicted secretion signals to direct the extracellular delivery of significant levels of active Nb_An33. We show that the pelB leader peptide was successful in directing the export of fully functional Nb_An33 to the periplasm of S. glossinidius resulting in significant levels of extracellular release. Finally, S. glossinidius expressing pelBNb_An33 exhibited no significant reduction in terms of fitness, determined by in vitro growth kinetics, compared to the wild-type strain.<br><br>CONCLUSIONS: These data are the first demonstration of the expression and extracellular release of functional trypanosome-interfering Nanobodies&#xae; in S. glossinidius. Furthermore, Sodalis strains that efficiently released the effector protein were not affected in their growth, suggesting that they may be competitive with endogenous microbiota in the midgut environment of the tsetse fly. Collectively, these data reinforce the notion for the potential of S. glossinidius to be developed into a paratransgenic platform organism.}, }
@article {pmid22334517, year = {2012}, author = {Costa, SC and Schmitz, AM and Jahufar, FF and Boyd, JD and Cho, MY and Glicksman, MA and Lesser, CF}, title = {A new means to identify type 3 secreted effectors: functionally interchangeable class IB chaperones recognize a conserved sequence.}, journal = {mBio}, volume = {3}, number = {1}, pages = {}, pmid = {22334517}, issn = {2150-7511}, support = {P30 DK043351/DK/NIDDK NIH HHS/United States ; R01 AI064285/AI/NIAID NIH HHS/United States ; R21 AI096134/AI/NIAID NIH HHS/United States ; }, mesh = {Algorithms ; Amino Acid Sequence ; Bacterial Proteins/metabolism ; *Bacterial Secretion Systems ; Computational Biology ; Conserved Sequence ; Enterobacteriaceae/*metabolism/physiology ; HeLa Cells ; Humans ; Molecular Chaperones/*metabolism ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Protein Binding ; Protein Interaction Domains and Motifs ; Protein Interaction Mapping/*methods ; Protein Transport ; Salmonella typhimurium/metabolism/physiology ; Shigella/metabolism/*physiology ; Species Specificity ; Substrate Specificity ; Symbiosis ; }, abstract = {UNLABELLED: Many Gram-negative bacteria utilize specialized secretion systems to inject proteins (effectors) directly into host cells. Little is known regarding how bacteria ensure that only small subsets of the thousands of proteins they encode are recognized as substrates of the secretion systems, limiting their identification through bioinformatic analyses. Many of these proteins require chaperones to direct their secretion. Here, using the newly described protein interaction platform assay, we demonstrate that type 3 secretion system class IB chaperones from one bacterium directly bind their own effectors as well as those from other species. In addition, we observe that expression of class IB homologs from seven species, including pathogens and endosymbionts, mediate the translocation of effectors from Shigella directly into host cells, demonstrating that class IB chaperones are often functionally interchangeable. Notably, class IB chaperones bind numerous effectors. However, as previously proposed, they are not promiscuous; rather they recognize a defined sequence that we designate the conserved chaperone-binding domain (CCBD) sequence [(LMIF)(1)XXX(IV)(5)XX(IV)(8)X(N)(10)]. This sequence is the first defined amino acid sequence to be identified for any interspecies bacterial secretion system, i.e., a system that delivers proteins directly into eukaryotic cells. This sequence provides a new means to identify substrates of type III secretion systems. Indeed, using a pattern search algorithm for the CCBD sequence, we have identified the first two probable effectors from an endosymbiont, Sodalis glossinidius.<br><br>IMPORTANCE: Many Gram-negative pathogens utilize type 3 secretion systems to deliver tens of effectors into host cells. In order to understand the diverse ways that these organisms cause disease, it is necessary to identify their effectors, many of which require chaperones to be secreted. Here we establish that class IB chaperones are not promiscuous, as previously proposed, but rather recognize a conserved effector sequence. We demonstrate that pattern search algorithms based on this defined sequence can be used to identify previously unknown effectors. Furthermore, we observe that class IB chaperones from at least seven bacterial species are functionally interchangeable. Not only do they bind and mediate the delivery of their own set of effectors into host cells but they also bind to type 3 substrates from other bacteria, suggesting that inhibitors that block chaperone-effector interactions could provide a novel means to effectively treat infections due to Gram-negative pathogens, including organisms resistant to currently available antibiotics.}, }
@article {pmid22334516, year = {2012}, author = {Rio, RV and Symula, RE and Wang, J and Lohs, C and Wu, YN and Snyder, AK and Bjornson, RD and Oshima, K and Biehl, BS and Perna, NT and Hattori, M and Aksoy, S}, title = {Insight into the transmission biology and species-specific functional capabilities of tsetse (Diptera: glossinidae) obligate symbiont Wigglesworthia.}, journal = {mBio}, volume = {3}, number = {1}, pages = {}, pmid = {22334516}, issn = {2150-7511}, support = {R01 AI081774/AI/NIAID NIH HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; AI068932/AI/NIAID NIH HHS/United States ; R01 AI068932/AI/NIAID NIH HHS/United States ; GM062994/GM/NIGMS NIH HHS/United States ; GM069449/GM/NIGMS NIH HHS/United States ; R01 GM062994/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Chorismic Acid/biosynthesis ; DNA, Bacterial/genetics/metabolism ; Evolution, Molecular ; Flagella/genetics/metabolism ; Folic Acid/biosynthesis ; Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; *Genome, Insect ; Immunohistochemistry ; Inheritance Patterns ; Molecular Sequence Data ; Phenylalanine/biosynthesis ; Plasmids/genetics/metabolism ; Species Specificity ; *Symbiosis ; Synteny ; Transcription, Genetic ; Tsetse Flies/genetics/metabolism/*microbiology ; Wigglesworthia/genetics/metabolism/*physiology ; }, abstract = {UNLABELLED: Ancient endosymbionts have been associated with extreme genome structural stability with little differentiation in gene inventory between sister species. Tsetse flies (Diptera: Glossinidae) harbor an obligate endosymbiont, Wigglesworthia, which has coevolved with the Glossina radiation. We report on the ~720-kb Wigglesworthia genome and its associated plasmid from Glossina morsitans morsitans and compare them to those of the symbiont from Glossina brevipalpis. While there was overall high synteny between the two genomes, a large inversion was noted. Furthermore, symbiont transcriptional analyses demonstrated host tissue and development-specific gene expression supporting robust transcriptional regulation in Wigglesworthia, an unprecedented observation in other obligate mutualist endosymbionts. Expression and immunohistochemistry confirmed the role of flagella during the vertical transmission process from mother to intrauterine progeny. The expression of nutrient provisioning genes (thiC and hemH) suggests that Wigglesworthia may function in dietary supplementation tailored toward host development. Furthermore, despite extensive conservation, unique genes were identified within both symbiont genomes that may result in distinct metabolomes impacting host physiology. One of these differences involves the chorismate, phenylalanine, and folate biosynthetic pathways, which are uniquely present in Wigglesworthia morsitans. Interestingly, African trypanosomes are auxotrophs for phenylalanine and folate and salvage both exogenously. It is possible that W. morsitans contributes to the higher parasite susceptibility of its host species.<br><br>IMPORTANCE: Genomic stasis has historically been associated with obligate endosymbionts and their sister species. Here we characterize the Wigglesworthia genome of the tsetse fly species Glossina morsitans and compare it to its sister genome within G. brevipalpis. The similarity and variation between the genomes enabled specific hypotheses regarding functional biology. Expression analyses indicate significant levels of transcriptional regulation and support development- and tissue-specific functional roles for the symbiosis previously not observed in obligate mutualist symbionts. Retention of the genetically expensive flagella within these small genomes was demonstrated to be significant in symbiont transmission and tailored to the unique tsetse fly reproductive biology. Distinctions in metabolomes were also observed. We speculate an additional role for Wigglesworthia symbiosis where infections with pathogenic trypanosomes may depend upon symbiont species-specific metabolic products and thus influence the vector competence traits of different tsetse fly host species.}, }
@article {pmid22333491, year = {2012}, author = {Kjeldsen, KU and Bataillon, T and Pinel, N and De Mita, S and Lund, MB and Panitz, F and Bendixen, C and Stahl, DA and Schramm, A}, title = {Purifying selection and molecular adaptation in the genome of Verminephrobacter, the heritable symbiotic bacteria of earthworms.}, journal = {Genome biology and evolution}, volume = {4}, number = {3}, pages = {307-315}, pmid = {22333491}, issn = {1759-6653}, mesh = {Animals ; Comamonadaceae/*genetics/physiology ; *Evolution, Molecular ; Genome, Bacterial/*genetics ; Molecular Sequence Data ; Oligochaeta/*microbiology ; Symbiosis ; }, abstract = {While genomic erosion is common among intracellular symbionts, patterns of genome evolution in heritable extracellular endosymbionts remain elusive. We study vertically transmitted extracellular endosymbionts (Verminephrobacter, Betaproteobacteria) that form a beneficial, species-specific, and evolutionarily old (60-130 Myr) association with earthworms. We assembled a draft genome of Verminephrobacter aporrectodeae and compared it with the genomes of Verminephrobacter eiseniae and two nonsymbiotic close relatives (Acidovorax). Similar to V. eiseniae, the V. aporrectodeae genome was not markedly reduced in size and showed no A-T bias. We characterized the strength of purifying selection (ω = dN/dS) and codon usage bias in 876 orthologous genes. Symbiont genomes exhibited strong purifying selection (ω = 0.09 ± 0.07), although transition to symbiosis entailed relaxation of purifying selection as evidenced by 50% higher ω values and less codon usage bias in symbiont compared with reference genomes. Relaxation was not evenly distributed among functional gene categories but was overrepresented in genes involved in signal transduction and cell envelope biogenesis. The same gene categories also harbored instances of positive selection in the Verminephrobacter clade. In total, positive selection was detected in 89 genes, including also genes involved in DNA metabolism, tRNA modification, and TonB-dependent iron uptake, potentially highlighting functions important in symbiosis. Our results suggest that the transition to symbiosis was accompanied by molecular adaptation, while purifying selection was only moderately relaxed, despite the evolutionary age and stability of the host association. We hypothesize that biparental transmission of symbionts and rare genetic mixing during transmission can prevent genome erosion in heritable symbionts.}, }
@article {pmid22307293, year = {2012}, author = {Kuechler, SM and Renz, P and Dettner, K and Kehl, S}, title = {Diversity of symbiotic organs and bacterial endosymbionts of lygaeoid bugs of the families blissidae and lygaeidae (hemiptera: heteroptera: lygaeoidea).}, journal = {Applied and environmental microbiology}, volume = {78}, number = {8}, pages = {2648-2659}, pmid = {22307293}, issn = {1098-5336}, mesh = {Animal Structures/*microbiology ; Animals ; *Bacterial Physiological Phenomena ; Chaperonin 60/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification ; Heteroptera/*microbiology/physiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Here we present comparative data on the localization and identity of intracellular symbionts among the superfamily Lygaeoidea (Insecta: Hemiptera: Heteroptera: Pentatomomorpha). Five different lygaeoid species from the families Blissidae and Lygaeidae (sensu stricto; including the subfamilies Lygaeinae and Orsillinae) were analyzed. Fluorescence in situ hybridization (FISH) revealed that all the bugs studied possess paired bacteriomes that are differently shaped in the abdomen and harbor specific endosymbionts therein. The endosymbionts were also detected in female gonads and at the anterior poles of developing eggs, indicating vertical transmission of the endosymbionts via ovarial passage, in contrast to the posthatch symbiont transmission commonly found among pentatomoid bugs (Pentatomomorpha: Pentatomoidea). Phylogenetic analysis based on 16S rRNA and groEL genes showed that the endosymbionts of Ischnodemus sabuleti, Arocatus longiceps, Belonochilus numenius, Orsillus depressus, and Ortholomus punctipennis constitute at least four distinct clades in the Gammaproteobacteria. The endosymbiont phylogeny did not agree with the host phylogeny based on the mitochondrial cytochrome oxidase I (COI) gene, but there was a local cospeciating pattern within the subfamily Orsillinae. Meanwhile, the endosymbiont of Belonochilus numenius (Lygaeidae: Orsillinae), although harbored in paired bacteriomes as in other lygaeoid bugs of the related genera Nysius, Ortholomus, and Orsillus, was phylogenetically close to "Candidatus Rohrkolberia cinguli," the endosymbiont of Chilacis typhae (Lygaeoidea: Artheneidae), suggesting an endosymbiont replacement in this lineage. The diverse endosymbionts and the differently shaped bacteriomes may reflect independent evolutionary origins of the endosymbiotic systems among lygaeoid bugs.}, }
@article {pmid22293464, year = {2012}, author = {Singh, ST and Priya, NG and Kumar, J and Rana, VS and Ellango, R and Joshi, A and Priyadarshini, G and Asokan, R and Rajagopal, R}, title = {Diversity and phylogenetic analysis of endosymbiotic bacteria from field caught Bemisia tabaci from different locations of North India based on 16S rDNA library screening.}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {12}, number = {2}, pages = {411-419}, doi = {10.1016/j.meegid.2012.01.015}, pmid = {22293464}, issn = {1567-7257}, mesh = {Animals ; Bacteria/*classification/*genetics ; DNA, Ribosomal/chemistry ; Evolution, Molecular ; *Genetic Variation ; Hemiptera/*microbiology ; India ; *Phylogeny ; Phylogeography ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Bemisia tabaci is the major vector pest of agricultural crops all over the world. In this study we report the different bacterial endosymbionts associated with B. tabaci sampled from 14 different locations in North India. Using 16S rDNA clone library sequences we were able to identify Portiera, the primary endosymbiont of B. tabaci, and other secondary endosymbionts like Cardinium, Wolbachia, Rickettsia and Arsenophonus. Along with these we also detected Bacillus, Enterobacter, Paracoccus and Acinetobacter. These secondary endosymbionts were not uniformly distributed in all the locations. Phylogenetic analysis of 16S rDNA sequences of Cardinium, Wolbachia, Rickettsia and Arsenophonus showed that each of these bacteria form a separate cluster when compared to their respective counterparts from other parts of the world. MtCO1 gene based phylogenetic analysis showed the presence of Asia I and Asia II genetic groups of B. tabaci in N. India. The multiple correspondence analyses showed no correlation between the host genetic group and the endosymbiont diversity. These results suggest that the bacterial endosymbiont diversity of B. tabaci is much larger and complex than previously perceived and probably N. Indian strains of the bacterial symbionts could have evolved from some other ancestor.}, }
@article {pmid22292008, year = {2012}, author = {Belda, E and Silva, FJ and Peretó, J and Moya, A}, title = {Metabolic networks of Sodalis glossinidius: a systems biology approach to reductive evolution.}, journal = {PloS one}, volume = {7}, number = {1}, pages = {e30652}, pmid = {22292008}, issn = {1932-6203}, mesh = {Animals ; Animals, Genetically Modified ; Computer Simulation ; Directed Molecular Evolution/*methods ; Enterobacteriaceae/*genetics/*metabolism ; Enterobacteriaceae Infections/metabolism/microbiology ; Escherichia coli/genetics/metabolism ; Evolution, Molecular ; Genome, Bacterial/genetics ; Host-Pathogen Interactions/genetics ; Metabolic Networks and Pathways/genetics/*physiology ; Models, Biological ; Phenotype ; Systems Biology/methods ; Tsetse Flies/metabolism/microbiology ; }, abstract = {BACKGROUND: Genome reduction is a common evolutionary process affecting bacterial lineages that establish symbiotic or pathogenic associations with eukaryotic hosts. Such associations yield highly reduced genomes with greatly streamlined metabolic abilities shaped by the type of ecological association with the host. Sodalis glossinidius, the secondary endosymbiont of tsetse flies, represents one of the few complete genomes available of a bacterium at the initial stages of this process. In the present study, genome reduction is studied from a systems biology perspective through the reconstruction and functional analysis of genome-scale metabolic networks of S. glossinidius.<br><br>RESULTS: The functional profile of ancestral and extant metabolic networks sheds light on the evolutionary events underlying transition to a host-dependent lifestyle. Meanwhile, reductive evolution simulations on the extant metabolic network can predict possible future evolution of S. glossinidius in the context of genome reduction. Finally, knockout simulations in different metabolic systems reveal a gradual decrease in network robustness to different mutational events for bacterial endosymbionts at different stages of the symbiotic association.<br><br>CONCLUSIONS: Stoichiometric analysis reveals few gene inactivation events whose effects on the functionality of S. glossinidius metabolic systems are drastic enough to account for the ecological transition from a free-living to host-dependent lifestyle. The decrease in network robustness across different metabolic systems may be associated with the progressive integration in the more stable environment provided by the insect host. Finally, reductive evolution simulations reveal the strong influence that external conditions exert on the evolvability of metabolic systems.}, }
@article {pmid22291901, year = {2012}, author = {Riparbelli, MG and Giordano, R and Ueyama, M and Callaini, G}, title = {Wolbachia-mediated male killing is associated with defective chromatin remodeling.}, journal = {PloS one}, volume = {7}, number = {1}, pages = {e30045}, pmid = {22291901}, issn = {1932-6203}, mesh = {Animals ; Chromatin Assembly and Disassembly/genetics/*physiology ; Drosophila/embryology/genetics/*microbiology ; Embryo, Nonmammalian ; Embryonic Development/physiology ; Female ; Genetic Predisposition to Disease ; Male ; Meiosis/genetics/physiology ; Rickettsiaceae Infections/embryology/microbiology/*mortality/veterinary ; *Sex Characteristics ; Spindle Apparatus/genetics/metabolism/physiology ; Wolbachia/*pathogenicity/*physiology ; }, abstract = {Male killing, induced by different bacterial taxa of maternally inherited microorganisms, resulting in highly distorted female-biased sex-ratios, is a common phenomenon among arthropods. Some strains of the endosymbiont bacteria Wolbachia have been shown to induce this phenotype in particular insect hosts. High altitude populations of Drosophila bifasciata infected with Wolbachia show selective male killing during embryonic development. However, since this was first reported, circa 60 years ago, the interaction between Wolbachia and its host has remained unclear. Herein we show that D. bifasciata male embryos display defective chromatin remodeling, improper chromatid segregation and chromosome bridging, as well as abnormal mitotic spindles and gradual loss of their centrosomes. These defects occur at different times in the early development of male embryos leading to death during early nuclear division cycles or large defective areas of the cellular blastoderm, culminating in abnormal embryos that die before eclosion. We propose that Wolbachia affects the development of male embryos by specifically targeting male chromatin remodeling and thus disturbing mitotic spindle assembly and chromosome behavior. These are the first observations that demonstrate fundamental aspects of the cytological mechanism of male killing and represent a solid base for further molecular studies of this phenomenon.}, }
@article {pmid22288602, year = {2012}, author = {Van Der Giezen, M and Lenton, TM}, title = {The rise of oxygen and complex life.}, journal = {The Journal of eukaryotic microbiology}, volume = {59}, number = {2}, pages = {111-113}, doi = {10.1111/j.1550-7408.2011.00605.x}, pmid = {22288602}, issn = {1550-7408}, mesh = {Biological Evolution ; Ecosystem ; Environment ; Eukaryota/*genetics/metabolism ; Mitochondria/metabolism ; Oxygen/analysis/*metabolism ; }, abstract = {Mitochondria have been put forward as the saviours of anaerobes when their environment became oxygenated. However, despite oxygenic photosynthesis evolving around 2.7 billion years ago (Ga), followed by the "Great Oxidation" of the atmosphere ~ 2.4 Ga, the deep oceans remained largely anoxic and either iron-enriched or sulphidic until 580 million years ago, when the eukaryotic radiation was well underway. Atmospheric oxygen probably remained at an intermediate concentration (1-10% of the present level) from ~ 2.4 until ~ 0.8 Ga when a "lesser oxidation" began. This drastically changes the textbook view of the ecological conditions under which the mitochondrial endosymbiont established itself. It could explain the widespread distribution of anaerobic biochemistry in every eukaryotic supergroup: anaerobic biochemistry is hard-wired into the eukaryotes.}, }
@article {pmid22280837, year = {2012}, author = {Tsagkarakou, A and Mouton, L and Kristoffersen, JB and Dokianakis, E and Grispou, M and Bourtzis, K}, title = {Population genetic structure and secondary endosymbionts of Q Bemisia tabaci (Hemiptera: Aleyrodidae) from Greece.}, journal = {Bulletin of entomological research}, volume = {102}, number = {3}, pages = {353-365}, doi = {10.1017/S0007485311000757}, pmid = {22280837}, issn = {1475-2670}, mesh = {Animals ; Ecosystem ; Female ; Gene Flow ; *Genetics, Population ; Greece ; Hemiptera/classification/*genetics/microbiology ; Magnoliopsida/parasitology ; Male ; Microsatellite Repeats ; Phylogeography ; *Polymorphism, Genetic ; *Symbiosis ; Wolbachia/physiology ; }, abstract = {We investigated the molecular diversity of the major agricultural pest Bemisia tabaci and of its associated secondary endosymbionts in Greece. Analyzing mitochondrial DNA, we found that the Q1 (=Q west) is predominant. We used eight microsatellite polymorphic markers to study the genetic structure of 37 populations from mainland and insular Greece, collected on different host species from outdoor and protected crops as well as from non-cultivated plants. In some cases, gene flow was found to be low even between populations separated by just a few kilometres. Bayesian analysis identified two main genetic groups, the first encompassing populations from south Crete and the second composed of populations from north Crete, two other Aegean islands and mainland Greece. Genetic differentiation was not correlated with different host plant species or habitat, or greenhouse versus open environment populations. Gene flow significantly decreased with geographic distance, but no isolation by distance existed when only the samples from mainland Greece or only the samples from Crete were considered. The secondary symbionts Wolbachia and Hamiltonella were present at high frequencies while Arsenophonus, Cardinium and Rickettsia were absent from Greek populations. Multilocus sequence typing of Wolbachia identified two Wolbachia strains. These two strains were found together in most of the populations studied but never in the same host individual. Their role on the observed population structure is discussed.}, }
@article {pmid22276535, year = {2012}, author = {Ferrari, J and West, JA and Via, S and Godfray, HC}, title = {Population genetic structure and secondary symbionts in host-associated populations of the pea aphid complex.}, journal = {Evolution; international journal of organic evolution}, volume = {66}, number = {2}, pages = {375-390}, doi = {10.1111/j.1558-5646.2011.01436.x}, pmid = {22276535}, issn = {1558-5646}, support = {D19263//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/*genetics/*microbiology/physiology ; Bacteria/*classification ; Bacterial Physiological Phenomena ; England ; Germany ; Plants/*classification ; Symbiosis ; }, abstract = {Polyphagous insect herbivores experience different selection pressures on their various host plant species. How this affects population divergence and speciation may be influenced by the bacterial endosymbionts that many harbor. Here, we study the population structure and symbiont community of the pea aphid (Acyrthosiphon pisum), which feeds on a range of legume species and is known to form genetically differentiated host-adapted populations. Aphids were collected from eight legume genera in England and Germany. Extensive host plant associated differentiation was observed with this collection of pea aphids comprising nine genetic clusters, each of which could be associated with a specific food plant. Compared to host plant, geography contributed little to genetic differentiation. The genetic clusters were differentiated to varying degrees, but this did not correlate with their degree of divergence in host use. We surveyed the pea aphid clones for the presence of six facultative (secondary) bacterial endosymbionts and found they were nonrandomly distributed across the aphid genetic clusters and this distribution was similar in the two countries. Aphid clones on average carried 1.4 species of secondary symbiont with those associated with Lathyrus having significantly fewer. The results are interpreted in the light of the evolution of specialization and ecological speciation.}, }
@article {pmid22276171, year = {2012}, author = {Ito, A and Matsuo, J and Nakamura, S and Yoshida, A and Okude, M and Hayashi, Y and Sakai, H and Yoshida, M and Takahashi, K and Yamaguchi, H}, title = {Amoebal endosymbiont Protochlamydia induces apoptosis to human immortal HEp-2 cells.}, journal = {PloS one}, volume = {7}, number = {1}, pages = {e30270}, pmid = {22276171}, issn = {1932-6203}, mesh = {Amoeba/*microbiology ; Animals ; Apoptosis/*physiology ; Cell Line ; Chlamydia/*growth &amp; development/physiology ; Chlorocebus aethiops ; Chromatin/metabolism ; Humans ; Jurkat Cells ; Vero Cells ; }, abstract = {Protochlamydia, an environmental chlamydia and obligate amoebal endosymbiotic bacterium, evolved to survive within protist hosts, such as Acanthamobae, 700 million years ago. However, these bacteria do not live in vertebrates, including humans. This raises the possibility that interactions between Protochlamydia and human cells could induce a novel cytopathic effect, leading to new insights into host-parasite relationships. Therefore, we studied the effect of Protochlamydia on the survival of human immortal cell line, HEp-2 cells and primary peripheral blood mononuclear cells (PBMC). Using mainly 4',6-diamidino-2-phenylindole staining, fluorescent in situ hybridization, transmission electron microscopy, and also TUNEL and Transwell assays, we demonstrated that the Protochlamydia induced apoptosis in HEp-2 cells. The attachment of viable bacterial cells, but not an increase of bacterial infectious progenies within the cells, was required for the apoptosis. Other chlamydiae [Parachlamydia acanthamoebae and Chlamydia trachomatis (serovars D and L2)] did not induce the same phenomena, indicating that the observed apoptosis may be specific to the Protochlamydia. Furthermore, the bacteria had no effect on the survival of primary PBMCs collected from five volunteers, regardless of activation. We concluded that Protochlamydia induces apoptosis in human-immortal HEp-2 cells and that this endosymbiont could potentially be used as a biological tool for the elucidation of novel host-parasite relationships.}, }
@article {pmid22268975, year = {2012}, author = {Gebiola, M and Gómez-Zurita, J and Monti, MM and Navone, P and Bernardo, U}, title = {Integration of molecular, ecological, morphological and endosymbiont data for species delimitation within the Pnigalio soemius complex (Hymenoptera: Eulophidae).}, journal = {Molecular ecology}, volume = {21}, number = {5}, pages = {1190-1208}, doi = {10.1111/j.1365-294X.2011.05428.x}, pmid = {22268975}, issn = {1365-294X}, mesh = {Animals ; Cell Nucleus/genetics ; DNA, Mitochondrial/genetics ; Genetic Markers ; *Genetic Speciation ; *Genetic Variation ; Genetics, Population ; Hymenoptera/*classification/genetics/microbiology ; Molecular Sequence Data ; Multivariate Analysis ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Integrative taxonomy is a recently developed approach that uses multiple lines of evidence such as molecular, morphological, ecological and geographical data to test species limits, and it stands as one of the most promising approaches to species delimitation in taxonomically difficult groups. The Pnigalio soemius complex (Hymenoptera: Eulophidae) represents an interesting taxonomical and ecological study case, as it is characterized by a lack of informative morphological characters, deep mitochondrial divergence, and is susceptible to infection by parthenogenesis-inducing Rickettsia. We tested the effectiveness of an integrative taxonomy approach in delimiting species within the P. soemius complex. We analysed two molecular markers (COI and ITS2) using different methods, performed multivariate analysis on morphometric data and exploited ecological data such as host-plant system associations, geographical separation, and the prevalence, type and effects of endosymbiont infection. The challenge of resolving different levels of resolution in the data was met by setting up a formal procedure of data integration within and between conflicting independent lines of evidence. An iterative corroboration process of multiple sources of data eventually indicated the existence of several cryptic species that can be treated as stable taxonomic hypotheses. Furthermore, the integrative approach confirmed a trend towards host specificity within the presumed polyphagous P. soemius and suggested that Rickettsia could have played a major role in the reproductive isolation and genetic diversification of at least two species.}, }
@article {pmid22267775, year = {2012}, author = {Hirakawa, Y and Burki, F and Keeling, PJ}, title = {Genome-based reconstruction of the protein import machinery in the secondary plastid of a chlorarachniophyte alga.}, journal = {Eukaryotic cell}, volume = {11}, number = {3}, pages = {324-333}, pmid = {22267775}, issn = {1535-9786}, mesh = {Amino Acid Sequence ; Cercozoa/*genetics/metabolism ; Chloroplast Proteins/*genetics/metabolism ; Chromosome Mapping ; *Genome ; Molecular Sequence Data ; Phylogeny ; Plastids/*genetics/metabolism ; Protein Transport ; Protozoan Proteins/*genetics/metabolism ; Sequence Alignment ; }, abstract = {Most plastid proteins are encoded by their nuclear genomes and need to be targeted across multiple envelope membranes. In vascular plants, the translocons at the outer and inner envelope membranes of chloroplasts (TOC and TIC, respectively) facilitate transport across the two plastid membranes. In contrast, several algal groups harbor more complex plastids, the so-called secondary plastids, which are surrounded by three or four membranes, but the plastid protein import machinery (in particular, how proteins cross the membrane corresponding to the secondary endosymbiont plasma membrane) remains unexplored in many of these algae. To reconstruct the putative protein import machinery of a secondary plastid, we used the chlorarachniophyte alga Bigelowiella natans, whose plastid is bounded by four membranes and still possesses a relict nucleus of a green algal endosymbiont (the nucleomorph) in the intermembrane space. We identified nine homologs of plant-like TOC/TIC components in the recently sequenced B. natans nuclear genome, adding to the two that remain in the nucleomorph genome (B. natans TOC75 [BnTOC75] and BnTIC20). All of these proteins were predicted to be localized to the plastid and might function in the inner two membranes. We also show that the homologs of a protein, Der1, that is known to mediate transport across the second membrane in the several lineages with secondary plastids of red algal origin is not associated with plastid protein targeting in B. natans. How plastid proteins cross this membrane remains a mystery, but it is clear that the protein transport machinery of chlorarachniophyte plastids differs from that of red algal secondary plastids.}, }
@article {pmid22266203, year = {2012}, author = {Martins, C and Souza, RF and Bueno, OC}, title = {Presence and distribution of the endosymbiont Wolbachia among Solenopsis spp. (Hymenoptera: Formicidae) from Brazil and its evolutionary history.}, journal = {Journal of invertebrate pathology}, volume = {109}, number = {3}, pages = {287-296}, doi = {10.1016/j.jip.2012.01.001}, pmid = {22266203}, issn = {1096-0805}, mesh = {Amino Acid Sequence ; Animals ; Ants/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; *Biological Evolution ; Brazil ; Disease Transmission, Infectious ; Genes, Insect/genetics ; Gram-Negative Bacterial Infections/*epidemiology/*genetics/transmission ; Molecular Sequence Data ; Reverse Transcriptase Polymerase Chain Reaction ; Wolbachia/*classification/*genetics ; }, abstract = {Wolbachia are intracellular bacteria that commonly infect arthropods. Its prevalence among ants of the genus Solenopsis is high. In the present study, the presence and distribution of these endosymbionts was examined among populations of Solenopsis spp. from Brazil. A phylogenetic analysis based on the wsp gene was conducted to infer the evolutionary history of Wolbachia infections within the populations surveyed. A high frequency of Wolbachia bacteria was observed among the genus Solenopsis, 51% of the colonies examined were infected. Incidence was higher in populations from southern Brazil. However, little genetic variability was found among different Wolbachia strains within supergroups A and B. Our findings also suggest that horizontal transmission events can occur through the social parasite S. daguerrei.}, }
@article {pmid22253228, year = {2012}, author = {Shimoda, Y and Han, L and Yamazaki, T and Suzuki, R and Hayashi, M and Imaizumi-Anraku, H}, title = {Rhizobial and fungal symbioses show different requirements for calmodulin binding to calcium calmodulin-dependent protein kinase in Lotus japonicus.}, journal = {The Plant cell}, volume = {24}, number = {1}, pages = {304-321}, pmid = {22253228}, issn = {1532-298X}, mesh = {Calcium-Calmodulin-Dependent Protein Kinases/genetics/*metabolism ; Calmodulin/genetics/*metabolism ; Fungi/*physiology ; Lotus/genetics/*metabolism ; Molecular Sequence Data ; Protein Binding ; Rhizobium/*physiology ; Symbiosis/physiology ; }, abstract = {Ca(2+)/calmodulin (CaM)-dependent protein kinase (CCaMK) is a key regulator of root nodule and arbuscular mycorrhizal symbioses and is believed to be a decoder for Ca(2+) signals induced by microbial symbionts. However, it is unclear how CCaMK is activated by these microbes. Here, we investigated in vivo activation of CCaMK in symbiotic signaling, focusing mainly on the significance of and epistatic relationships among functional domains of CCaMK. Loss-of-function mutations in EF-hand motifs revealed the critical importance of the third EF hand for CCaMK activation to promote infection of endosymbionts. However, a gain-of-function mutation (T265D) in the kinase domain compensated for these loss-of-function mutations in the EF hands. Mutation of the CaM binding domain abolished CaM binding and suppressed CCaMK(T265D) activity in rhizobial infection, but not in mycorrhization, indicating that the requirement for CaM binding to CCaMK differs between root nodule and arbuscular mycorrhizal symbioses. Homology modeling and mutagenesis studies showed that the hydrogen bond network including Thr265 has an important role in the regulation of CCaMK. Based on these genetic, biochemical, and structural studies, we propose an activation mechanism of CCaMK in which root nodule and arbuscular mycorrhizal symbioses are distinguished by differential regulation of CCaMK by CaM binding.}, }
@article {pmid22238660, year = {2012}, author = {Pochon, X and Putnam, HM and Burki, F and Gates, RD}, title = {Identifying and characterizing alternative molecular markers for the symbiotic and free-living dinoflagellate genus Symbiodinium.}, journal = {PloS one}, volume = {7}, number = {1}, pages = {e29816}, pmid = {22238660}, issn = {1932-6203}, mesh = {Algorithms ; Animals ; Base Sequence ; Cloning, Molecular/*methods ; Computational Biology ; Dinoflagellida/*classification/*genetics ; Genes, Protozoan/genetics/physiology ; Genetic Association Studies ; Genetic Markers/*genetics ; Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Dinoflagellates in the genus Symbiodinium are best known as endosymbionts of corals and other invertebrate as well as protist hosts, but also exist free-living in coastal environments. Despite their importance in marine ecosystems, less than 10 loci have been used to explore phylogenetic relationships in this group, and only the multi-copy nuclear ribosomal Internal Transcribed Spacer (ITS) regions 1 and 2 have been used to characterize fine-scale genetic diversity within the nine clades (A-I) that comprise the genus. Here, we describe a three-step molecular approach focused on 1) identifying new candidate genes for phylogenetic analysis of Symbiodinium spp., 2) characterizing the phylogenetic relationship of these candidate genes from DNA samples spanning eight Symbiodinium clades (A-H), and 3) conducting in-depth phylogenetic analyses of candidate genes displaying genetic divergences equal or higher than those within the ITS-2 of Symbiodinium clade C. To this end, we used bioinformatics tools and reciprocal comparisons to identify homologous genes from 55,551 cDNA sequences representing two Symbiodinium and six additional dinoflagellate EST libraries. Of the 84 candidate genes identified, 7 Symbiodinium genes (elf2, coI, coIII, cob, calmodulin, rad24, and actin) were characterized by sequencing 23 DNA samples spanning eight Symbiodinium clades (A-H). Four genes displaying higher rates of genetic divergences than ITS-2 within clade C were selected for in-depth phylogenetic analyses, which revealed that calmodulin has limited taxonomic utility but that coI, rad24, and actin behave predictably with respect to Symbiodinium lineage C and are potential candidates as new markers for this group. The approach for targeting candidate genes described here can serve as a model for future studies aimed at identifying and testing new phylogenetically informative genes for taxa where transcriptomic and genomics data are available.}, }
@article {pmid22236497, year = {2012}, author = {Albers, A and Esum, ME and Tendongfor, N and Enyong, P and Klarmann, U and Wanji, S and Hoerauf, A and Pfarr, K}, title = {Retarded Onchocerca volvulus L1 to L3 larval development in the Simulium damnosum vector after anti-wolbachial treatment of the human host.}, journal = {Parasites &amp; vectors}, volume = {5}, number = {}, pages = {12}, pmid = {22236497}, issn = {1756-3305}, mesh = {Adult ; Animals ; Anti-Bacterial Agents/*administration &amp; dosage ; Cameroon ; DNA, Bacterial/genetics ; Doxycycline/*administration &amp; dosage ; Human Experimentation ; Humans ; Larva/growth &amp; development/microbiology ; Male ; Middle Aged ; Onchocerca volvulus/*growth &amp; development/microbiology ; Polymerase Chain Reaction ; Simuliidae/*parasitology ; Treatment Outcome ; Wolbachia/*drug effects/isolation &amp; purification ; Young Adult ; }, abstract = {BACKGROUND: The human parasite Onchocerca volvulus harbours Wolbachia endosymbionts essential for worm embryogenesis, larval development and adult survival. In this study, the development of Wolbachia-depleted microfilariae (first stage larvae) to infective third stage larvae (L3) in the insect vector Simulium damnosum was analysed.<br><br>METHODS: Infected volunteers in Cameroon were randomly and blindly allocated into doxycycline (200 mg/day for 6 weeks) or placebo treatment groups. After treatment, blackflies were allowed to take a blood meal on the volunteers, captured and dissected for larval counting and DNA extraction for quantitative real-time PCR analysis.<br><br>RESULTS: PCR results showed a clear reduction in Wolbachia DNA after doxycycline treatment in microfilariae from human skin biopsies with > 50% reduction at one month post-treatment, eventually reaching a reduction of > 80%. Larval stages recovered from the insect vector had similar levels of reduction of endosymbiotic bacteria. Larval recoveries were analysed longitudinally after treatment to follow the kinetics of larval development. Beginning at three months post-treatment, significantly fewer L3 were seen in the blackflies that had fed on doxycycline treated volunteers. Concomitant with this, the proportion of second stage larvae (L2) was significantly increased in this group.<br><br>CONCLUSIONS: Doxycycline treatment and the resulting decline of Wolbachia endobacteria from the microfilaria resulted in retarded development of larvae in the insect vector. Thus, anti-wolbachial treatment could have an additive effect for interrupting transmission by reducing the number of L3 that can be transmitted by blackflies.}, }
@article {pmid22233324, year = {2011}, author = {Chai, HN and Du, YZ and Qiu, BL and Zhai, BP}, title = {Detection and phylogenetic analysis of Wolbachia in the Asiatic rice leafroller, Cnaphalocrocis medinalis, in Chinese populations.}, journal = {Journal of insect science (Online)}, volume = {11}, number = {}, pages = {123}, pmid = {22233324}, issn = {1536-2442}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; China ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/genetics ; Moths/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {Wolbachia are a group of intracellular inherited endosymbiontic bacteria infecting a wide range of insects. In this study the infection status of Wolbachia (Rickettsiales: Rickettsiaceae) was measured in the Asiatic rice leafroller, Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae), from twenty locations in China by sequencing wsp, ftsZ and 16S rDNA genes. The results showed high infection rates of Wolbachia in C. medinalis populations. Wolbachia was detected in all geographically separate populations; the average infection rate was ~ 62.5%, and the highest rates were 90% in Wenzhou and Yangzhou populations. The Wolbachia detected in different C. medinalis populations were 100% identical to each other when wsp, ftsZ, and 16S rDNA sequences were compared, with all sequences belonging to the Wolbachia B supergroup. Based on wsp, ftsZ and 16S rDNA sequences of Wolbachia, three phylogenetic trees of similar pattern emerged. This analysis indicated the possibility of inter-species and intra-species horizontal transmission of Wolbachia in different arthropods in related geographical regions. The migration route of C. medinalis in mainland China was also discussed since large differentiation had been found between the wsp sequences of Chinese and Thai populations.}, }
@article {pmid22224502, year = {2012}, author = {Cuddy, WS and Neilan, BA and Gehringer, MM}, title = {Comparative analysis of cyanobacteria in the rhizosphere and as endosymbionts of cycads in drought-affected soils.}, journal = {FEMS microbiology ecology}, volume = {80}, number = {1}, pages = {204-215}, doi = {10.1111/j.1574-6941.2011.01288.x}, pmid = {22224502}, issn = {1574-6941}, mesh = {Base Sequence ; Cyanobacteria/*classification/genetics/growth &amp; development/isolation &amp; purification ; Cycas/*microbiology/physiology ; Droughts ; Nostoc ; Phylogeny ; Plant Roots/microbiology ; *Rhizosphere ; Soil/chemistry ; *Soil Microbiology ; Symbiosis ; }, abstract = {Does the diversity of cyanobacteria in the cycad rhizosphere relate to the cyanobiont species found in the coralloid roots of these ancient plants? The aim of this study was to identify the diversity of soil cyanobacteria occurring in the immediate vicinity of 22 colonized coralloid roots belonging to members of the cycad genera: Macrozamia, Lepidozamia, Bowenia and Cycas. The majority of coralloid roots were sampled at depths > 10 cm below the soil surface. A total of 32 cyanobacterial isolates were cultured and their 16S rRNA gene partially sequenced. Phylogenetic analysis revealed nine operational taxonomic units of soil cyanobacteria comprising 30 Nostoc spp., a Tolypothrix sp. and a Leptolyngbya sp. Microscopy indicated that all isolates were unialgal and confirmed their genus identity. Rhizospheric diversity was compared to existing data on cyanobionts isolated at the same time from the cycad coralloid root. The same isolate was present in both the cycad coralloid root and rhizosphere at only six sites. Phylogenetic evidence indicates that most rhizosphere isolates were distinct from root cyanobionts. This weak relationship between the soil cyanobacteria and cycad cyanobionts might indicate that changes in the soil community composition are due to environmental factors.}, }
@article {pmid22222826, year = {2012}, author = {Suryanarayanan, TS}, title = {Fungal endosymbionts of seaweeds.}, journal = {Progress in molecular and subcellular biology}, volume = {53}, number = {}, pages = {53-69}, doi = {10.1007/978-3-642-23342-5_3}, pmid = {22222826}, issn = {0079-6484}, mesh = {Animals ; Bacteria/metabolism ; Ecosystem ; *Fungi ; Herbivory ; Marine Biology ; *Seaweed/microbiology ; }, abstract = {Seaweeds are being studied for their role in supporting coastal marine life and nutrient cycling and for their bioactive metabolites. For a more complete understanding of seaweed communities, it is essential to obtain information about their interactions with various other components of their ecosystem. While interactions of seaweeds with herbivores such as fish and mesograzers and surface colonizers such as bacteria and microalgae are known, their interactions with marine and marine-derived fungi are little understood. This chapter highlights the need for investigations on the little-known ecological group of fungi, viz. the fungal endosymbionts, that have intimate associations with seaweeds.}, }
@article {pmid22221919, year = {2012}, author = {Moestrup, O and Garcia-Cuetos, L and Hansen, PJ and Fenchel, T}, title = {Studies on the genus Mesodinium I: ultrastructure and description of Mesodinium chamaeleon n. sp., a benthic marine species with green or red chloroplasts.}, journal = {The Journal of eukaryotic microbiology}, volume = {59}, number = {1}, pages = {20-39}, doi = {10.1111/j.1550-7408.2011.00593.x}, pmid = {22221919}, issn = {1550-7408}, mesh = {Chloroplasts/ultrastructure ; Ciliophora/*classification/*cytology/isolation &amp; purification/physiology ; Cryptophyta/growth &amp; development ; DNA, Protozoan/chemistry/genetics ; Digestion ; Eating ; Feeding Behavior ; Microscopy ; Molecular Sequence Data ; Sequence Analysis, DNA ; Vacuoles/parasitology ; }, abstract = {We provide here the description of a new marine species that harbors green or red chloroplasts. In contrast to certain other species of the genus, Mesodinium chamaeleon n. sp. can be maintained in culture for short periods only. It captures and ingests flagellates including cryptomonads. The prey is ingested very rapidly into a food vacuole without the cryptomonad flagella being shed and the trichocysts being discharged. The individual food vacuoles subsequently serve as photosynthetic units, each containing the cryptomonad chloroplast, a nucleus, and some mitochondria. The ingested cells are eventually digested. This type of symbiosis differs from other plastid-bearing Mesodinium spp. in retaining ingested cryptomonad cells almost intact. The food strategy of the new species appears to be intermediate between heterotrophic species, such as Mesodinium pulex and Mesodinium pupula, and species with red cryptomonad endosymbionts, such as Mesodinium rubrum.}, }
@article {pmid22221759, year = {2012}, author = {Gopi, M and Kumaran, S and Kumar, TT and Deivasigamani, B and Alagappan, K and Prasad, SG}, title = {Antibacterial potential of sponge endosymbiont marine Enterobacter sp at Kavaratti Island, Lakshadweep archipelago.}, journal = {Asian Pacific journal of tropical medicine}, volume = {5}, number = {2}, pages = {142-146}, doi = {10.1016/S1995-7645(12)60013-3}, pmid = {22221759}, issn = {2352-4146}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Aquatic Organisms/chemistry ; Dysidea/*chemistry/microbiology ; Enterobacter/*chemistry ; Enterobacteriaceae/*drug effects ; Escherichia coli/drug effects ; India ; Klebsiella pneumoniae/drug effects ; Marine Biology ; Phylogeny ; Salmonella typhi/drug effects ; Staphylococcus aureus/drug effects ; Streptococcus/drug effects ; }, abstract = {OBJECTIVE: To isolate antibacterial potential of sponge endosymbiotic bacteria from marine sponges at Lakshadweep archipelago. Also to identify the potent bacteria by 16s rDNA sequencing and determine the antibacterial activity against clinical pathogens by MIC.<br><br>METHODS: Sponge samples was collected from sub-tidal habitats at Kavaratti Island and identified. The endosymbiotic bacteria were isolated and selected potential bacteria which show antibacterial activity in preliminary screening against clinical pathogens Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), Salmonella typhi (S. typhi), Klebsiella pneumoniea (K. pneumoniea) and Streptococcus sp. by disc diffusion assay. The crude extracts of potential bacteria LB3 was tested against clinical pathogens by MIC. The LB3 strain was identified by 16s rDNA sequencing, 1 111 bp was submitted in NCBI (HQ589912) and constructed phylogenetic tree.<br><br>RESULTS: Sponge sample was identified as Dysidea granulosa (D. granulosa) and potential bacteria LB3 identified as Enterobacter sp TTAG. Preliminary screening of sponge isolates against clinical pathogens, LB3 strain was selected as potential producer of secondary metabolites and crude extract was implies on MIC of LB3 have confirmed with lowest concentration of 5.0 mg/mL in broth medium influence of crude extract on growth inhibitory activity after 5 h of incubation period and completed the inhibitory activity at 15 h.<br><br>CONCLUSIONS: The present study concluded that phylogenetic analysis of endosymbiotic bacteria Enterobacter sp from sponge D. granulosa of Lakshadweep islands showed significant antibacterial activity against clinical bacterial pathogens.}, }
@article {pmid22217755, year = {2011}, author = {He, H and Chen, Y and Zhang, Y and Wei, C}, title = {Bacteria associated with gut lumen of Camponotus japonicus Mayr.}, journal = {Environmental entomology}, volume = {40}, number = {6}, pages = {1405-1409}, doi = {10.1603/EN11157}, pmid = {22217755}, issn = {1938-2936}, mesh = {Animals ; Ants/*microbiology/physiology ; Bacteria/classification/*genetics ; China ; DNA, Bacterial/chemistry/genetics ; Intestines/microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Camponotus ants harbor the obligate intracellular endosymbiont Blochmannia in their midgut bacteriocytes, but little is known about intestinal bacteria living in the gut lumen. In this paper we reported the results of a survey of the intestinal microflora of Camponotus japonicus Mayr based on small-subunit rRNA genes (16S rRNAs) polymerase chain reaction (PCR)-restriction fragment-length polymorphism analysis of worker guts. From 107 clones, 11 different restriction fragment-length polymorphism profiles were identified, and sequences blasting analysis found these represent four types of bacteria. Most (91.6%) of the clones were "Candidatus Blochmannia", the obligate endosymbionts of Camponotus ants, and 6.5% of the clones were "Candidatus Serratia symbiotica", a secondary endosymbiont of aphids; the remaining 2% clones were Fructobacillus fructosus and uncultured Burkholderiales bacterium, respectively. These results show that the diversity of gut bacteria in C. japonicus was low. "Candidatus Serratia symbiotica" was identified from Camponotus ants for the first time, an interesting result because Blochmannia's closest bacterial relative is also in the genus Serratia. This discovery supports the scenario that consumption of aphid honeydew or tissue provides an initial step in the evolution of an advanced symbiosis, and suggests that Camponotus ant could acquire other secondary endosymbionts from Hemiptera host through their diet. In addition, Burkholderiales bacterium also was identified from the gut of C. japonicus for the first time, and whether it is a nitrogen-recycling endosymbiont in Camponotus ants needs to be investigated further.}, }
@article {pmid22216307, year = {2011}, author = {Thornhill, DJ and Rotjan, RD and Todd, BD and Chilcoat, GC and Iglesias-Prieto, R and Kemp, DW and LaJeunesse, TC and Reynolds, JM and Schmidt, GW and Shannon, T and Warner, ME and Fitt, WK}, title = {A connection between colony biomass and death in Caribbean reef-building corals.}, journal = {PloS one}, volume = {6}, number = {12}, pages = {e29535}, pmid = {22216307}, issn = {1932-6203}, mesh = {Animals ; *Anthozoa ; *Biomass ; Caribbean Region ; Seasons ; }, abstract = {Increased sea-surface temperatures linked to warming climate threaten coral reef ecosystems globally. To better understand how corals and their endosymbiotic dinoflagellates (Symbiodinium spp.) respond to environmental change, tissue biomass and Symbiodinium density of seven coral species were measured on various reefs approximately every four months for up to thirteen years in the Upper Florida Keys, United States (1994-2007), eleven years in the Exuma Cays, Bahamas (1995-2006), and four years in Puerto Morelos, Mexico (2003-2007). For six out of seven coral species, tissue biomass correlated with Symbiodinium density. Within a particular coral species, tissue biomasses and Symbiodinium densities varied regionally according to the following trends: Mexico≥Florida Keys≥Bahamas. Average tissue biomasses and symbiont cell densities were generally higher in shallow habitats (1-4 m) compared to deeper-dwelling conspecifics (12-15 m). Most colonies that were sampled displayed seasonal fluctuations in biomass and endosymbiont density related to annual temperature variations. During the bleaching episodes of 1998 and 2005, five out of seven species that were exposed to unusually high temperatures exhibited significant decreases in symbiotic algae that, in certain cases, preceded further decreases in tissue biomass. Following bleaching, Montastraea spp. colonies with low relative biomass levels died, whereas colonies with higher biomass levels survived. Bleaching- or disease-associated mortality was also observed in Acropora cervicornis colonies; compared to A. palmata, all A. cervicornis colonies experienced low biomass values. Such patterns suggest that Montastraea spp. and possibly other coral species with relatively low biomass experience increased susceptibility to death following bleaching or other stressors than do conspecifics with higher tissue biomass levels.}, }
@article {pmid22216157, year = {2011}, author = {LaJeunesse, TC and Thornhill, DJ}, title = {Improved resolution of reef-coral endosymbiont (Symbiodinium) species diversity, ecology, and evolution through psbA non-coding region genotyping.}, journal = {PloS one}, volume = {6}, number = {12}, pages = {e29013}, pmid = {22216157}, issn = {1932-6203}, mesh = {Animals ; *Anthozoa/classification/genetics ; Base Sequence ; *Biodiversity ; DNA Primers ; *Ecology ; *Evolution, Molecular ; Genotype ; Photosystem II Protein Complex/*genetics ; Phylogeny ; }, abstract = {Ribosomal DNA sequence data abounds from numerous studies on the dinoflagellate endosymbionts of corals, and yet the multi-copy nature and intragenomic variability of rRNA genes and spacers confound interpretations of symbiont diversity and ecology. Making consistent sense of extensive sequence variation in a meaningful ecological and evolutionary context would benefit from the application of additional genetic markers. Sequences of the non-coding region of the plastid psbA minicircle (psbA(ncr)) were used to independently examine symbiont genotypic and species diversity found within and between colonies of Hawaiian reef corals in the genus Montipora. A single psbA(ncr) haplotype was recovered in most samples through direct sequencing (~80-90%) and members of the same internal transcribed spacer region 2 (ITS2) type were phylogenetically differentiated from other ITS2 types by substantial psbA(ncr) sequence divergence. The repeated sequencing of bacterially-cloned fragments of psbA(ncr) from samples and clonal cultures often recovered a single numerically common haplotype accompanied by rare, highly-similar, sequence variants. When sequence artifacts of cloning and intragenomic variation are factored out, these data indicate that most colonies harbored one dominant Symbiodinium genotype. The cloning and sequencing of ITS2 DNA amplified from these same samples recovered numerically abundant variants (that are diagnostic of distinct Symbiodinium lineages), but also generated a large amount of sequences comprising PCR/cloning artifacts combined with ancestral and/or rare variants that, if incorporated into phylogenetic reconstructions, confound how small sequence differences are interpreted. Finally, psbA(ncr) sequence data from a broad sampling of Symbiodinium diversity obtained from various corals throughout the Indo-Pacific were concordant with ITS lineage membership (defined by denaturing gradient gel electrophoresis screening), yet exhibited substantially greater sequence divergence and revealed strong phylogeographic structure corresponding to major biogeographic provinces. The detailed genetic resolution provided by psbA(ncr) data brings further clarity to the ecology, evolution, and systematics of symbiotic dinoflagellates.}, }
@article {pmid22214329, year = {2012}, author = {Genchi, C and Kramer, LH and Sassera, D and Bandi, C}, title = {Wolbachia and its implications for the immunopathology of filariasis.}, journal = {Endocrine, metabolic &amp; immune disorders drug targets}, volume = {12}, number = {1}, pages = {53-56}, doi = {10.2174/187153012799279108}, pmid = {22214329}, issn = {2212-3873}, mesh = {Animals ; Filariasis/*immunology/*microbiology ; Filarioidea/*immunology/*microbiology ; Host-Parasite Interactions/immunology ; Humans ; Immunomodulation/physiology ; Symbiosis/immunology/physiology ; Wolbachia/immunology/*physiology ; }, abstract = {Filarial infections are characterized by immunopathological phenomena, that are responsible for the onset of often dramatic pathological outcomes, such as blindness (Onchocerca volvulus) and elephantiasis (W. bancrofti). In addition, the long-term survival (as long as 10 years) of these parasites in otherwise immunocompetent hosts indicates that these nematodes are capable of manipulating the host immune response. The ground-breaking discovery of the bacterial endosymbiont Wolbachia, which resides in most filarial nematodes causing disease, has led to increasing interest in the role it may play in immuno-modulation, pro-inflammatory pathology and other aspects of filarial infection. Indeed, Wolbachia has been shown to be responsible for exacerbating inflammation (as in river blindness), while at the same time blocking efficient elimination of parasites through the host immune response (Onchocerca ochengi). While studies aimed at identifying Wolbachia as a potential target for anti-filarial therapy are at the forefront of current research, understanding its role in the immunology of filarial infection is a fascinating field that has yet to uncover many secrets.}, }
@article {pmid22210220, year = {2012}, author = {Hughes, GL and Vega-Rodriguez, J and Xue, P and Rasgon, JL}, title = {Wolbachia strain wAlbB enhances infection by the rodent malaria parasite Plasmodium berghei in Anopheles gambiae mosquitoes.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {5}, pages = {1491-1495}, pmid = {22210220}, issn = {1098-5336}, support = {R01 AI031478/AI/NIAID NIH HHS/United States ; R21 AI070178/AI/NIAID NIH HHS/United States ; 5R01AI031478/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/parasitology ; Animals ; Anopheles/*parasitology ; Drosophila melanogaster/parasitology ; Gastrointestinal Tract/parasitology ; Mice ; Parasite Egg Count ; Plasmodium berghei/*microbiology/*pathogenicity ; *Symbiosis ; Virulence ; Wolbachia/*physiology ; }, abstract = {Wolbachia, a common bacterial endosymbiont of insects, has been shown to protect its hosts against a wide range of pathogens. However, not all strains exert a protective effect on their host. Here we assess the effects of two divergent Wolbachia strains, wAlbB from Aedes albopictus and wMelPop from Drosophila melanogaster, on the vector competence of Anopheles gambiae challenged with Plasmodium berghei. We show that the wAlbB strain significantly increases P. berghei oocyst levels in the mosquito midgut while wMelPop modestly suppresses oocyst levels. The wAlbB strain is avirulent to mosquitoes while wMelPop is moderately virulent to mosquitoes pre-blood meal and highly virulent after mosquitoes have fed on mice. These various effects on P. berghei levels suggest that Wolbachia strains differ in their interactions with the host and/or pathogen, and these differences could be used to dissect the molecular mechanisms that cause interference of pathogen development in mosquitoes.}, }
@article {pmid22209953, year = {2012}, author = {Mackiewicz, P and Bodył, A and Gagat, P}, title = {Possible import routes of proteins into the cyanobacterial endosymbionts/plastids of Paulinella chromatophora.}, journal = {Theory in biosciences = Theorie in den Biowissenschaften}, volume = {131}, number = {1}, pages = {1-18}, pmid = {22209953}, issn = {1611-7530}, mesh = {Amino Acid Sequence ; Amino Acids/chemistry ; Computational Biology/methods ; Cyanobacteria/*metabolism ; Genomics ; Mitochondria/metabolism ; Models, Biological ; Molecular Sequence Data ; Molecular Weight ; Photosystem I Protein Complex/genetics/physiology ; Plastids/metabolism ; Protein Sorting Signals ; Protein Structure, Tertiary ; Protein Transport ; Rhizaria/*metabolism ; Sequence Homology, Amino Acid ; Signal Transduction ; Symbiosis/genetics/*physiology ; }, abstract = {The rhizarian amoeba Paulinella chromatophora harbors two photosynthetically active and deeply integrated cyanobacterial endosymbionts acquired ~60 million years ago. Recent genomic analyses of P. chromatophora have revealed the loss of many essential genes from the endosymbiont's genome, and have identified more than 30 genes that have been transferred to the host cell's nucleus through endosymbiotic gene transfer (EGT). This indicates that, similar to classical primary plastids, Paulinella endosymbionts have evolved a transport system to import their nuclear-encoded proteins. To deduce how these proteins are transported, we searched for potential targeting signals in genes for 10 EGT-derived proteins. Our analyses indicate that five proteins carry potential signal peptides, implying they are targeted via the host endomembrane system. One sequence encodes a mitochondrial-like transit peptide, which suggests an import pathway involving a channel protein residing in the outer membrane of the endosymbiont. No N-terminal targeting signals were identified in the four other genes, but their encoded proteins could utilize non-classical targeting signals contained internally or in C-terminal regions. Several amino acids more often found in the Paulinella EGT-derived proteins than in their ancestral set (proteins still encoded in the endosymbiont genome) could constitute such signals. Characteristic features of the EGT-derived proteins are low molecular weight and nearly neutral charge, which both could be adaptations to enhance passage through the peptidoglycan wall present in the intermembrane space of the endosymbiont's envelope. Our results suggest that Paulinella endosymbionts/plastids have evolved several different import routes, as has been shown in classical primary plastids.}, }
@article {pmid22206462, year = {2011}, author = {Philippe, H and Roure, B}, title = {Difficult phylogenetic questions: more data, maybe; better methods, certainly.}, journal = {BMC biology}, volume = {9}, number = {}, pages = {91}, pmid = {22206462}, issn = {1741-7007}, mesh = {Enterobacteriaceae/*genetics ; *Phylogeny ; *Symbiosis ; }, abstract = {Contradicting the prejudice that endosymbiosis is a rare phenomenon, Husník and co-workers show in BMC Biology that bacterial endosymbiosis has occured several times independently during insect evolution. Rigorous phylogenetic analyses, in particular using complex models of sequence evolution and an original site removal procedure, allow this conclusion to be established after eschewing inference artefacts that usually plague the positioning of highly divergent endosymbiont genomic sequences.}, }
@article {pmid22203556, year = {2011}, author = {Lemaire, B and Robbrecht, E and van Wyk, B and Van Oevelen, S and Verstraete, B and Prinsen, E and Smets, E and Dessein, S}, title = {Identification, origin, and evolution of leaf nodulating symbionts of Sericanthe (Rubiaceae).}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {49}, number = {6}, pages = {935-941}, pmid = {22203556}, issn = {1976-3794}, mesh = {*Biological Evolution ; Burkholderia/classification/genetics/*isolation &amp; purification/*physiology ; Molecular Sequence Data ; Phylogeny ; Rubiaceae/*microbiology/physiology ; *Symbiosis ; }, abstract = {Bacterial leaf symbiosis is an intimate association between bacteria and plants in which endosymbionts are housed within leaf nodules. This phenomenon has been reported in three genera of Rubiaceae (Pavetta, Psychotria, and Sericanthe), but the bacterial partner has only been identified in Psychotria and Pavetta. Here we report the identification of symbiotic bacteria in two leaf nodulating Sericanthe species. Using 16S rRNA data and common housekeeping genetic markers (recA and gyrB) we studied the phylogenetic relationships of bacterial endosymbionts in Rubiaceae. Endosymbionts of leaf nodulating Rubiaceae were found to be closely related and were placed as a monophyletic group within the genus Burkholderia (β-Proteobacteria). The phylogenetic analyses revealed a pattern of strict host specificity and placed the two investigated endosymbionts at two distinct positions in the topology of the tree, suggesting at least two different evolutionary origins. The degree of sequence divergence between the Sericanthe endosymbionts and their relatives was large enough to propose the Sericanthe endosymbionts as new species ('Candidatus Burkholderia andongensis' and 'Candidatus Burkholderia petitii'). In a second part of this study, the pylogenetic relationships among nodulating and non-nodulating Sericanthe species were investigated using sequence data from six chloroplast regions (rps16, trnG, trnL-trnF, petD, petA-psbJ, and atpI-atpH). Overall, genetic variation among the plastid markers was insufficient to enable phylogenetic estimation. However, our results could not rule out the possibility that bacterial leaf symbiosis originated once in a common ancestor of the Sericanthe species.}, }
@article {pmid22194999, year = {2011}, author = {Bordenstein, SR and Bordenstein, SR}, title = {Temperature affects the tripartite interactions between bacteriophage WO, Wolbachia, and cytoplasmic incompatibility.}, journal = {PloS one}, volume = {6}, number = {12}, pages = {e29106}, pmid = {22194999}, issn = {1932-6203}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteriophages/*physiology ; Colony Count, Microbial ; Cytoplasm/*metabolism ; Models, Biological ; Penetrance ; Wasps/*microbiology ; Wolbachia/growth &amp; development/*physiology/*virology ; }, abstract = {Wolbachia infections are a model for understanding intracellular, bacterial symbioses. While the symbiosis is often studied from a binary perspective of host and bacteria, it is increasingly apparent that additional trophic levels can influence the symbiosis. For example, Wolbachia in arthropods harbor a widespread temperate bacteriophage, termed WO, that forms virions and rampantly transfers between coinfections. Here we test the hypothesis that temperatures at the extreme edges of an insect's habitable range alter bacteriophage WO inducibility and in turn, Wolbachia densities and the penetrance of cytoplasmic incompatibility. We report four key findings using the model wasp, Nasonia vitripennis: First, both cold treatment at 18 C and heat treatment at 30 C reduce Wolbachia densities by as much as 74% relative to wasps reared at 25 C. Second, in all cases where Wolbachia densities decline due to temperature changes, phage WO densities increase and inversely associate with Wolbachia densities. Heat has a marked effect on phage WO, yielding phage densities that are 552% higher than the room temperature control. Third, there is a significant affect of insect family on phage WO and endoysmbiont densities. Fourth, at extreme temperatures, there was a temperature-mediated adjustment to the density threshold at which Wolbachia cause complete cytoplasmic incompatibility. Taken together, these results demonstrate that temperature simultaneously affects phage WO densities, endosymbiont densities, and the penetrance of cytoplasmic incompatibility. While temperature shock enhances bacteriophage inducibility and the ensuing bacterial mortality in a wide range of medically and industrially-important bacteria, this is the first investigation of the associations in an obligate intracellular bacteria. Implications to a SOS global sensing feedback mechanism in Wolbachia are discussed.}, }
@article {pmid22194947, year = {2011}, author = {Wernegreen, JJ}, title = {Reduced selective constraint in endosymbionts: elevation in radical amino acid replacements occurs genome-wide.}, journal = {PloS one}, volume = {6}, number = {12}, pages = {e28905}, pmid = {22194947}, issn = {1932-6203}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/*genetics ; Analysis of Variance ; Animals ; Ants/microbiology ; Aphids/microbiology ; Base Sequence ; Buchnera/genetics ; Codon/genetics ; Computer Simulation ; Databases, Genetic ; Genetic Variation ; Genome, Bacterial/*genetics ; Phylogeny ; *Selection, Genetic ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {As predicted by the nearly neutral model of evolution, numerous studies have shown that reduced N(e) accelerates the accumulation of slightly deleterious changes under genetic drift. While such studies have mostly focused on eukaryotes, bacteria also offer excellent models to explore the effects of N(e). Most notably, the genomes of host-dependent bacteria with small N(e) show signatures of genetic drift, including elevated K(a)/K(s). Here, I explore the utility of an alternative measure of selective constraint: the per-site rate of radical and conservative amino acid substitutions (D(r)/D(c)). I test the hypothesis that purifying selection against radical amino acid changes is less effective in two insect endosymbiont groups (Blochmannia of ants and Buchnera of aphids), compared to related gamma-Proteobacteria. Genome comparisons demonstrate a significant elevation in D(r)/D(c) in endosymbionts that affects the majority (66-79%) of shared orthologs examined. The elevation of D(r)/D(c) in endosymbionts affects all functional categories examined. Simulations indicate that D(r)/D(c) estimates are sensitive to codon frequencies and mutational parameters; however, estimation biases occur in the opposite direction as the patterns observed in genome comparisons, thereby making the inference of elevated D(r)/D(c) more conservative. Increased D(r)/D(c) and other signatures of genome degradation in endosymbionts are consistent with strong effects of genetic drift in their small populations, as well as linkage to selected sites in these asexual bacteria. While relaxed selection against radical substitutions may contribute, genome-wide processes such as genetic drift and linkage best explain the pervasive elevation in D(r)/D(c) across diverse functional categories that include basic cellular processes. Although the current study focuses on a few bacterial lineages, it suggests D(r)/D(c) is a useful gauge of selective constraint and may provide a valuable alternative to K(a)/K(s) when high sequence divergences preclude estimates of K(s). Broader application of D(r)/D(c) will benefit from approaches less prone to estimation biases.}, }
@article {pmid22193955, year = {2011}, author = {Serbus, LR and Ferreccio, A and Zhukova, M and McMorris, CL and Kiseleva, E and Sullivan, W}, title = {A feedback loop between Wolbachia and the Drosophila gurken mRNP complex influences Wolbachia titer.}, journal = {Journal of cell science}, volume = {124}, number = {Pt 24}, pages = {4299-4308}, pmid = {22193955}, issn = {1477-9137}, support = {F32 GM080192/GM/NIGMS NIH HHS/United States ; R25 GM058903/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila Proteins/analysis/*genetics ; Drosophila melanogaster/genetics/microbiology/ultrastructure ; Feedback, Physiological ; Microtubules/physiology ; Oocytes/microbiology/ultrastructure ; Oogenesis ; RNA-Binding Proteins/analysis ; Ribonucleoproteins/*physiology ; Symbiosis ; Transforming Growth Factor alpha/*genetics ; Wolbachia/*physiology/ultrastructure ; }, abstract = {Although much is known about interactions between bacterial endosymbionts and their hosts, little is known concerning the host factors that influence endosymbiont titer. Wolbachia endosymbionts are globally dispersed throughout most insect species and are the causative agent in filarial nematode-mediated disease. Our investigation indicates that gurken (grk), a host gene encoding a crucial axis determinant, has a cumulative, dosage-sensitive impact on Wolbachia growth and proliferation during Drosophila oogenesis. This effect appears to be mediated by grk mRNA and its protein-binding partners Squid and Hrp48/Hrb27C, implicating the grk mRNA-protein (mRNP) complex as a rate-limiting host factor controlling Wolbachia titer. Furthermore, highly infected flies exhibit defects that match those occurring with disruption of grk mRNPs, such as nurse cell chromatin disruptions and malformation of chorionic appendages. These findings suggest a feedback loop in which Wolbachia interaction with the grk mRNP affects both Wolbachia titer and grk mRNP function.}, }
@article {pmid22179251, year = {2012}, author = {Dergousoff, SJ and Chilton, NB}, title = {Association of different genetic types of Francisella-like organisms with the rocky mountain wood tick (Dermacentor andersoni) and the American dog tick (Dermacentor variabilis) in localities near their northern distributional limits.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {4}, pages = {965-971}, pmid = {22179251}, issn = {1098-5336}, mesh = {Animals ; Canada ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Dermacentor/*microbiology ; Female ; Francisella/*classification/genetics/*isolation &amp; purification ; Male ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {Dermacentor andersoni and Dermacentor variabilis from allopatric and sympatric populations near their northern distributional limits were examined for the presence of Francisella species using molecular techniques that targeted 373 bp of the 16S rRNA gene. Although there was no evidence for the presence of Francisella tularensis in any tick, Francisella-like endosymbionts (FLEs) were common in D. andersoni and D. variabilis adults and immatures. A significantly greater proportion of female ticks contained FLEs compared to male ticks. In addition, significantly more D. variabilis adult individuals contained multiple FLE sequence types than did D. andersoni adults. Ten different types of FLEs were identified based on the sequence data, which has implications for diagnostic tests and epidemiological studies of F. tularensis in tick populations in Canada. The three most prevalent types of FLEs have been detected previously in D. andersoni or D. variabilis from other parts of their distributional ranges, whereas the other seven FLE types have not been reported previously. A comparison of the FLEs from both allopatric and sympatric populations of these two tick species provided insight into the relative host-specificity and the modes of transmission of these tick-borne bacteria. In general, each FLE type was specific for one tick species, suggesting vertical transmission of each bacterium. However, there were a few instances of potential cross-transfer of two FLE types to the other tick species at locations where D. andersoni and D. variabilis occurred in sympatry, suggesting that there may be occasional horizontal transmission of some FLEs.}, }
@article {pmid22156418, year = {2012}, author = {Gatehouse, LN and Sutherland, P and Forgie, SA and Kaji, R and Christeller, JT}, title = {Molecular and histological characterization of primary (betaproteobacteria) and secondary (gammaproteobacteria) endosymbionts of three mealybug species.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {4}, pages = {1187-1197}, pmid = {22156418}, issn = {1098-5336}, mesh = {Animals ; Betaproteobacteria/classification/genetics/*isolation &amp; purification/*physiology ; Closteroviridae/isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification/*physiology ; Hemiptera/*microbiology ; Histocytochemistry ; Molecular Sequence Data ; Phylogeny ; Plant Diseases/virology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Microscopic localization of endosymbiotic bacteria in three species of mealybug (Pseudococcus longispinus, the long-tailed mealybug; Pseudococcus calceolariae, the citrophilus mealybug; and Pseudococcus viburni, the obscure mealybug) showed these organisms were confined to bacteriocyte cells within a bacteriome centrally located within the hemocoel. Two species of bacteria were present, with the secondary endosymbiont, in all cases, living within the primary endosymbiont. DNA from the dissected bacteriomes of all three species of mealybug was extracted for analysis. Sequence data from selected 16S rRNA genes confirmed identification of the primary endosymbiont as "Candidatus Tremblaya princeps," a betaproteobacterium, and the secondary endosymbionts as gammaproteobacteria closely related to Sodalis glossinidius. A single 16S rRNA sequence of the primary endosymbiont was found in all individuals of each mealybug species. In contrast, the presence of multiple divergent strains of secondary endosymbionts in each individual mealybug suggests different evolutionary and transmission histories of the two endosymbionts. Mealybugs are known vectors of the plant pathogen Grapevine leafroll-associated virus 3. To examine the possible role of either endosymbiont in virus transmission, an extension of the model for interaction of proteins with bacterial chaperonins, i.e., GroEL protein homologs, based on mobile-loop amino acid sequences of their GroES homologs, was developed and used for analyses of viral coat protein interactions. The data from this model are consistent with a role for the primary endosymbiont in mealybug transmission of Grapevine leafroll-associated virus 3.}, }
@article {pmid22154393, year = {2012}, author = {Decelle, J and Suzuki, N and Mahé, F and de Vargas, C and Not, F}, title = {Molecular phylogeny and morphological evolution of the Acantharia (Radiolaria).}, journal = {Protist}, volume = {163}, number = {3}, pages = {435-450}, doi = {10.1016/j.protis.2011.10.002}, pmid = {22154393}, issn = {1618-0941}, mesh = {*Biological Evolution ; Molecular Sequence Data ; *Phylogeny ; Rhizaria/classification/*genetics/*growth &amp; development/isolation &amp; purification ; Seawater/parasitology ; }, abstract = {Acantharia are ubiquitous and abundant rhizarian protists in the world ocean. The skeleton made of strontium sulphate and the fact that certain harbour microalgal endosymbionts make them key planktonic players for the ecology of marine ecosystems. Based on morphological criteria, the current taxonomy of Acantharia was established by W.T. Schewiakoff in 1926, since when no major revision has been undertaken. Here, we established the first comprehensive molecular phylogeny from single morphologically-identified acantharian cells, isolated from various oceans. Our phylogenetic analyses based on 78 18S rDNA and 107 partial 28S rDNA revealed the existence of 6 main clades, sub-divided into 13 sub-clades. The polyphyletic nature of acantharian families and genera demonstrates the need for revision of the current taxonomy. This molecular phylogeny, which highlights the taxonomic relevance of specific morphological criteria, such as the presence of a shell and the organisation of the central junction, provides a robust phylogenetic framework for future taxonomic emendation. Finally, mapping all the existing environmental sequences available to date from different marine ecosystems onto our reference phylogeny unveiled another 3 clades and improved the understanding of the biogeography and ecology of Acantharia.}, }
@article {pmid22153895, year = {2012}, author = {Fujishima, M and Kodama, Y}, title = {Endosymbionts in paramecium.}, journal = {European journal of protistology}, volume = {48}, number = {2}, pages = {124-137}, doi = {10.1016/j.ejop.2011.10.002}, pmid = {22153895}, issn = {1618-0429}, mesh = {Chlorella/*physiology ; Holosporaceae/*physiology ; Host-Pathogen Interactions ; Paramecium/*microbiology ; *Symbiosis ; }, abstract = {Paramecium species are extremely valuable organisms to enable experiments for the reestablishment of endosymbiosis. This is investigated in two different systems, the first with Paramecium caudatum and the endonuclear symbiotic bacterium Holospora species. Although most endosymbiotic bacteria cannot grow outside the host cell as a result of their reduced genome size, Holospora species can maintain their infectivity for a limited time. We found that an 89-kDa periplasmic protein has an important function for Holospora's invasion into the target nucleus, and that Holospora alters the host gene expression; the host thereby acquires resistance against various stresses. The second system is the symbiosis between P. bursaria and symbiotic Chlorella. Alga-free P. bursaria and the algae retain the ability to grow without a partner. Consequently, endosymbiosis between the aposymbiotic host cells and the symbiotic algae can be reestablished easily by mixing them. We now found four checkpoints for the reestablishment of the endosymbiosis between P. bursaria and the algae. The findings in the two systems provide excellent opportunities for us to elucidate not only infection processes but also to assess the associations leading to eukaryotic cell evolution. This paper summarizes recent progresses on reestablishment of the primary and the secondary endosymbiosis in Paramecium.}, }
@article {pmid22152604, year = {2011}, author = {Bowman, DD}, title = {Introduction to the alpha-proteobacteria: Wolbachia and Bartonella, Rickettsia, Brucella, Ehrlichia, and Anaplasma.}, journal = {Topics in companion animal medicine}, volume = {26}, number = {4}, pages = {173-177}, doi = {10.1053/j.tcam.2011.09.002}, pmid = {22152604}, issn = {1946-9837}, mesh = {Anaplasma/growth &amp; development ; Animals ; Bartonella/growth &amp; development ; Brucella/growth &amp; development ; Cat Diseases/drug therapy/parasitology ; Cats ; Dirofilaria immitis/drug effects/*microbiology ; Dirofilariasis/*drug therapy/parasitology ; Dog Diseases/drug therapy/parasitology ; Dogs ; Doxycycline/*therapeutic use ; Ehrlichia/growth &amp; development ; Filaricides/*therapeutic use ; Rickettsia/growth &amp; development ; Symbiosis ; Wolbachia/growth &amp; development ; }, abstract = {Wolbachia is an obligate intracellular endosymbiont and likely mutualist living within the heartworm Dirofilaria immitis and a number of other filarial nematodes in the family Onchocercidae. The bacterial infection is passed from worm to worm transovarially; the organisms are in ovarian cells, the developing microfilariae, and multiply and persist in all later developmental stages through the mosquito and into the next host. Besides being present in the ovaries of the adult worms, they also are present in large numbers within the hypodermal tissues of the nematode. It is now know that these bacteria that were first observed in heartworms more than 30 years ago are actually related to similar Wolbachia bacteria that are found in arthropods. Wolbachia is an alpha-proteobacteria, and this group includes a number of important arthropod-transmitted bacterial agents of dogs and cats: Rickettsia rickettsii, R. felis, Anaplasma platys, Ehrlichia canis, E. chaffeensis, and E. ewingii. Alpha-proteobacteria are also important as obligate intracellular mutualists in plants in which they are responsible for nitrogen fixation. Recent work on the treatment of heartworms in dogs with doxycycline stems from related work with the human filarial nematode Onchocerca volvulus that causes river blindness in people.}, }
@article {pmid22151691, year = {2011}, author = {Muñoz, AG and Baxter, SW and Linares, M and Jiggins, CD}, title = {Deep mitochondrial divergence within a Heliconius butterfly species is not explained by cryptic speciation or endosymbiotic bacteria.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {358}, pmid = {22151691}, issn = {1471-2148}, mesh = {Amplified Fragment Length Polymorphism Analysis ; Animals ; Bacteria ; Butterflies/classification/*genetics/microbiology ; Cluster Analysis ; Colombia ; DNA, Mitochondrial/*genetics ; *Evolution, Molecular ; *Genetic Speciation ; Genetics, Population ; Haplotypes ; Phylogeny ; Polymorphism, Genetic ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: Cryptic population structure can be an indicator of incipient speciation or historical processes. We investigated a previously documented deep break in the mitochondrial haplotypes of Heliconius erato chestertonii to explore the possibility of cryptic speciation, and also the possible presence of endosymbiont bacteria that might drive mitochondrial population structure.<br><br>RESULTS: Among a sample of 315 individuals from 16 populations of western Colombia, two principal mtDNA clades were detected with 2.15% divergence and we confirmed this structure was weakly associated with geography. The first mtDNA clade included 87% of individuals from northern populations and was the sister group of H. erato members of Andes western, while the second clade contained most individuals from southern populations (78%), which shared haplotypes with an Ecuadorian race of H. erato. In contrast, analysis using AFLP markers showed H. e. chestertonii to be a genetically homogeneous species with no association between mitochondrial divergence and AFLP structure. The lack of congruence between molecular markers suggests that cryptic speciation is not a plausible explanation for the deep mitochondrial divergence in H. e chestertonii. We also carried out the first tests for the presence of endosymbiontic bacteria in Heliconius, and identified two distinct lineages of Wolbachia within H. e. chestertonii. However, neither of the principal mitochondrial clades of H. e. chestertonii was directly associated with the patterns of infection.<br><br>CONCLUSIONS: We conclude that historical demographic processes are the most likely explanation for the high mitochondrial differentiation in H. e. chestertonii, perhaps due to gene flow between Cauca valley H. e. chestertonii and west Pacific slope populations of H. erato.}, }
@article {pmid22144892, year = {2011}, author = {Sheiner, L and Demerly, JL and Poulsen, N and Beatty, WL and Lucas, O and Behnke, MS and White, MW and Striepen, B}, title = {A systematic screen to discover and analyze apicoplast proteins identifies a conserved and essential protein import factor.}, journal = {PLoS pathogens}, volume = {7}, number = {12}, pages = {e1002392}, pmid = {22144892}, issn = {1553-7374}, support = {AI64671/AI/NIAID NIH HHS/United States ; AI084415/AI/NIAID NIH HHS/United States ; R56 AI084415/AI/NIAID NIH HHS/United States ; R01 AI084415/AI/NIAID NIH HHS/United States ; R01 AI064671/AI/NIAID NIH HHS/United States ; }, mesh = {Apicomplexa/*genetics/metabolism/pathogenicity ; Cell Cycle/physiology ; Plastids/*genetics/metabolism ; Protein Transport/genetics ; Protozoan Proteins/*genetics/metabolism ; RNA, Messenger/biosynthesis/*genetics ; RNA, Protozoan/biosynthesis/*genetics ; }, abstract = {Parasites of the phylum Apicomplexa cause diseases that impact global health and economy. These unicellular eukaryotes possess a relict plastid, the apicoplast, which is an essential organelle and a validated drug target. However, much of its biology remains poorly understood, in particular its elaborate compartmentalization: four membranes defining four different spaces. Only a small number of organellar proteins have been identified in particular few proteins are known for non-luminal apicoplast compartments. We hypothesized that enlarging the catalogue of apicoplast proteins will contribute toward identifying new organellar functions and expand the realm of targets beyond a limited set of characterized pathways. We developed a bioinformatic screen based on mRNA abundance over the cell cycle and on phyletic distribution. We experimentally assessed 57 genes, and of 30 successful epitope tagged candidates eleven novel apicoplast proteins were identified. Of those, seven appear to target to the lumen of the organelle, and four localize to peripheral compartments. To address their function we then developed a robust system for the construction of conditional mutants via a promoter replacement strategy. We confirm the feasibility of this system by establishing conditional mutants for two selected genes--a luminal and a peripheral apicoplast protein. The latter is particularly intriguing as it encodes a hypothetical protein that is conserved in and unique to Apicomplexan parasites and other related organisms that maintain a red algal endosymbiont. Our studies suggest that this peripheral plastid protein, PPP1, is likely localized to the periplastid compartment. Conditional disruption of PPP1 demonstrated that it is essential for parasite survival. Phenotypic analysis of this mutant is consistent with a role of the PPP1 protein in apicoplast biogenesis, specifically in import of nuclear-encoded proteins into the organelle.}, }
@article {pmid22140592, year = {2011}, author = {Li, Z and Garner, AL and Gloeckner, C and Janda, KD and Carlow, CK}, title = {Targeting the Wolbachia cell division protein FtsZ as a new approach for antifilarial therapy.}, journal = {PLoS neglected tropical diseases}, volume = {5}, number = {11}, pages = {e1411}, pmid = {22140592}, issn = {1935-2735}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/*antagonists &amp; inhibitors/genetics/metabolism ; Berberine/*pharmacology ; Brugia malayi/*microbiology ; Cytoskeletal Proteins/*antagonists &amp; inhibitors/genetics/metabolism ; DNA, Bacterial/chemistry/genetics ; Enzyme Inhibitors/pharmacology ; Filaricides/*pharmacology ; GTP Phosphohydrolases/*antagonists &amp; inhibitors/genetics/metabolism ; Molecular Sequence Data ; Sequence Analysis, DNA ; Wolbachia/*drug effects ; }, abstract = {The use of antibiotics targeting the obligate bacterial endosymbiont Wolbachia of filarial parasites has been validated as an approach for controlling filarial infection in animals and humans. Availability of genomic sequences for the Wolbachia (wBm) present in the human filarial parasite Brugia malayi has enabled genome-wide searching for new potential drug targets. In the present study, we investigated the cell division machinery of wBm and determined that it possesses the essential cell division gene ftsZ which was expressed in all developmental stages of B. malayi examined. FtsZ is a GTPase thereby making the protein an attractive Wolbachia drug target. We described the molecular characterization and catalytic properties of Wolbachia FtsZ. We also demonstrated that the GTPase activity was inhibited by the natural product, berberine, and small molecule inhibitors identified from a high-throughput screen. Furthermore, berberine was also effective in reducing motility and reproduction in B. malayi parasites in vitro. Our results should facilitate the discovery of selective inhibitors of FtsZ as a novel anti-symbiotic approach for controlling filarial infection. NOTE: The nucleotide sequences reported in this paper are available in GenBank™ Data Bank under the accession number wAlB-FtsZ (JN616286).}, }
@article {pmid22132238, year = {2011}, author = {Kvist, S and Narechania, A and Oceguera-Figueroa, A and Fuks, B and Siddall, ME}, title = {Phylogenomics of Reichenowia parasitica, an alphaproteobacterial endosymbiont of the freshwater leech Placobdella parasitica.}, journal = {PloS one}, volume = {6}, number = {11}, pages = {e28192}, pmid = {22132238}, issn = {1932-6203}, mesh = {Alphaproteobacteria/*genetics/ultrastructure ; Animals ; Cluster Analysis ; *Fresh Water ; Genome Size ; Genome, Bacterial/genetics ; *Genomics ; Leeches/*microbiology ; Nonlinear Dynamics ; *Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Although several commensal alphaproteobacteria form close relationships with plant hosts where they aid in (e.g.,) nitrogen fixation and nodulation, only a few inhabit animal hosts. Among these, Reichenowia picta, R. ornata and R. parasitica, are currently the only known mutualistic, alphaproteobacterial endosymbionts to inhabit leeches. These bacteria are harbored in the epithelial cells of the mycetomal structures of their freshwater leech hosts, Placobdella spp., and these structures have no other obvious function than housing bacterial symbionts. However, the function of the bacterial symbionts has remained unclear. Here, we focused both on exploring the genomic makeup of R. parasitica and on performing a robust phylogenetic analysis, based on more data than previous hypotheses, to test its position among related bacteria. We sequenced a combined pool of host and symbiont DNA from 36 pairs of mycetomes and performed an in silico separation of the different DNA pools through subtractive scaffolding. The bacterial contigs were compared to 50 annotated bacterial genomes and the genome of the freshwater leech Helobdella robusta using a BLASTn protocol. Further, amino acid sequences inferred from the contigs were used as queries against the 50 bacterial genomes to establish orthology. A total of 358 orthologous genes were used for the phylogenetic analyses. In part, results suggest that R. parasitica possesses genes coding for proteins related to nitrogen fixation, iron/vitamin B translocation and plasmid survival. Our results also indicate that R. parasitica interacts with its host in part by transmembrane signaling and that several of its genes show orthology across Rhizobiaceae. The phylogenetic analyses support the nesting of R. parasitica within the Rhizobiaceae, as sister to a group containing Agrobacterium and Rhizobium species.}, }
@article {pmid22130021, year = {2011}, author = {Vavre, F and Mavingui, P}, title = {[Endosymbionts of arthropods and nematodes: allies to fight infectious diseases?].}, journal = {Medecine sciences : M/S}, volume = {27}, number = {11}, pages = {953-958}, doi = {10.1051/medsci/20112711010}, pmid = {22130021}, issn = {0767-0974}, mesh = {Animals ; Arthropods/genetics/*microbiology ; Bacteria/genetics/pathogenicity ; Bacterial Physiological Phenomena ; Communicable Diseases/*therapy ; Host-Parasite Interactions/genetics ; Humans ; Models, Biological ; Molecular Targeted Therapy/methods/trends ; Nematoda/genetics/*microbiology ; Symbiosis/genetics/*physiology ; }, abstract = {Arthropods and nematodes are important protagonists in human health because either they act as vectors of pathogens (bacteria, protozoa, viruses or fungus), or are themselves parasites. Fighting infectious diseases is based essentially on vaccination (prevention) or chemotherapeutic (curative) approaches in human, but one can envisage as an alternative to reduce the number of vectors or limit their ability to spread pathogens. Such strategies controlling dissemination will undoubtedly benefit from the knowledge accumulated by recent works on powerful mechanisms developed by symbiotic insect bacteria such as Wolbachia to popagate in arthropods and nematods. This review summarizes these recent data, and indicate how these mechanisms can be manipulated to reduce the dissemination of insect vectors propagating human diseases.}, }
@article {pmid22125637, year = {2011}, author = {Chaston, JM and Suen, G and Tucker, SL and Andersen, AW and Bhasin, A and Bode, E and Bode, HB and Brachmann, AO and Cowles, CE and Cowles, KN and Darby, C and de Léon, L and Drace, K and Du, Z and Givaudan, A and Herbert Tran, EE and Jewell, KA and Knack, JJ and Krasomil-Osterfeld, KC and Kukor, R and Lanois, A and Latreille, P and Leimgruber, NK and Lipke, CM and Liu, R and Lu, X and Martens, EC and Marri, PR and Médigue, C and Menard, ML and Miller, NM and Morales-Soto, N and Norton, S and Ogier, JC and Orchard, SS and Park, D and Park, Y and Qurollo, BA and Sugar, DR and Richards, GR and Rouy, Z and Slominski, B and Slominski, K and Snyder, H and Tjaden, BC and van der Hoeven, R and Welch, RD and Wheeler, C and Xiang, B and Barbazuk, B and Gaudriault, S and Goodner, B and Slater, SC and Forst, S and Goldman, BS and Goodrich-Blair, H}, title = {The entomopathogenic bacterial endosymbionts Xenorhabdus and Photorhabdus: convergent lifestyles from divergent genomes.}, journal = {PloS one}, volume = {6}, number = {11}, pages = {e27909}, pmid = {22125637}, issn = {1932-6203}, support = {AI55397/AI/NIAID NIH HHS/United States ; F32 GM072342/GM/NIGMS NIH HHS/United States ; AI007414/AI/NIAID NIH HHS/United States ; T32 AI007414/AI/NIAID NIH HHS/United States ; T32 AI055397/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Chromosomes, Bacterial/genetics ; DNA, Bacterial/chemistry/genetics ; Enterobacteriaceae/classification/genetics/physiology ; *Genetic Variation ; Genome, Bacterial/*genetics ; Genomics/methods ; Host-Parasite Interactions ; Host-Pathogen Interactions ; Insecta/microbiology/parasitology ; Molecular Sequence Data ; Nematoda/microbiology/physiology ; Photorhabdus/classification/*genetics/physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; Xenorhabdus/classification/*genetics/physiology ; }, abstract = {Members of the genus Xenorhabdus are entomopathogenic bacteria that associate with nematodes. The nematode-bacteria pair infects and kills insects, with both partners contributing to insect pathogenesis and the bacteria providing nutrition to the nematode from available insect-derived nutrients. The nematode provides the bacteria with protection from predators, access to nutrients, and a mechanism of dispersal. Members of the bacterial genus Photorhabdus also associate with nematodes to kill insects, and both genera of bacteria provide similar services to their different nematode hosts through unique physiological and metabolic mechanisms. We posited that these differences would be reflected in their respective genomes. To test this, we sequenced to completion the genomes of Xenorhabdus nematophila ATCC 19061 and Xenorhabdus bovienii SS-2004. As expected, both Xenorhabdus genomes encode many anti-insecticidal compounds, commensurate with their entomopathogenic lifestyle. Despite the similarities in lifestyle between Xenorhabdus and Photorhabdus bacteria, a comparative analysis of the Xenorhabdus, Photorhabdus luminescens, and P. asymbiotica genomes suggests genomic divergence. These findings indicate that evolutionary changes shaped by symbiotic interactions can follow different routes to achieve similar end points.}, }
@article {pmid22117087, year = {2012}, author = {Williams, LE and Wernegreen, JJ}, title = {Purifying selection, sequence composition, and context-specific indel mutations shape intraspecific variation in a bacterial endosymbiont.}, journal = {Genome biology and evolution}, volume = {4}, number = {1}, pages = {44-51}, pmid = {22117087}, issn = {1759-6653}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/genetics/microbiology ; Bacteria/*genetics ; DNA Replication/genetics ; DNA, Mitochondrial/genetics ; Evolution, Molecular ; *Genome, Bacterial ; Genotype ; Microsatellite Repeats/genetics ; Mitochondria/genetics ; *Mutation ; Polymorphism, Genetic ; Recombination, Genetic ; Replication Origin/genetics ; Symbiosis/*genetics ; }, abstract = {Comparative genomics of closely related bacterial strains can clarify mutational processes and selective forces that impact genetic variation. Among primary bacterial endosymbionts of insects, such analyses have revealed ongoing genome reduction, raising questions about the ultimate evolutionary fate of these partnerships. Here, we explored genomic variation within Blochmannia vafer, an obligate mutualist of the ant Camponotus vafer. Polymorphism analysis of the Illumina data set used previously for de novo assembly revealed a second Bl. vafer genotype. To determine why a single ant colony contained two symbiont genotypes, we examined polymorphisms in 12 C. vafer mitochondrial sequences assembled from the Illumina data; the spectrum of variants suggests that the colony contained two maternal lineages, each harboring a distinct Bl. vafer genotype. Comparing the two Bl. vafer genotypes revealed that purifying selection purged most indels and nonsynonymous differences from protein-coding genes. We also discovered that indels occur frequently in multimeric simple sequence repeats, which are relatively abundant in Bl. vafer and may play a more substantial role in generating variation in this ant mutualist than in the aphid endosymbiont Buchnera. Finally, we explored how an apparent relocation of the origin of replication in Bl. vafer and the resulting shift in strand-associated mutational pressures may have caused accelerated gene loss and an elevated rate of indel polymorphisms in the region spanning the origin relocation. Combined, these results point to significant impacts of purifying selection on genomic polymorphisms as well as distinct patterns of indels associated with unusual genomic features of Blochmannia.}, }
@article {pmid22116282, year = {2011}, author = {Ankola, K and Brueckner, D and Puttaraju, HP}, title = {Wolbachia endosymbiont infection in two Indian butterflies and female-biased sex ratio in the Red Pierrot, Talicada nyseus.}, journal = {Journal of biosciences}, volume = {36}, number = {5}, pages = {845-850}, pmid = {22116282}, issn = {0973-7138}, mesh = {Animals ; Butterflies/*microbiology/physiology ; Female ; Fertility ; Male ; Molecular Typing ; Sex Factors ; *Sex Ratio ; *Symbiosis ; *Wolbachia ; }, abstract = {The maternally inherited obligate bacteria Wolbachia is known to infect various lepidopteran insects. However, so far only a few butterfly species harbouring this bacterium have been thoroughly studied. The current study aims to identify the infection status of these bacteria in some of the commonly found butterfly species in India. A total of nine butterfly species belonging to four different families were screened using PCR with Wolbachia-specific wsp and ftsZ primers. The presence of the Wolbachia super group 'B' in the butterflies Red Pierrot, Talicada nyseus (Guerin) (Lepidoptera: Lycaenidae) and Blue Mormon, Papilio polymnestor Cramer (Papilionidae), is documented for the first time in India. The study also gives an account on the lifetime fecundity and female-biased sex ratio in T. nyseus, suggesting a putative role for Wolbachia in the observed female-biased sex ratio distortion.}, }
@article {pmid22115919, year = {2012}, author = {Iguchi, A and Ozaki, S and Nakamura, T and Inoue, M and Tanaka, Y and Suzuki, A and Kawahata, H and Sakai, K}, title = {Effects of acidified seawater on coral calcification and symbiotic algae on the massive coral Porites australiensis.}, journal = {Marine environmental research}, volume = {73}, number = {}, pages = {32-36}, doi = {10.1016/j.marenvres.2011.10.008}, pmid = {22115919}, issn = {1879-0291}, mesh = {Acids/metabolism ; Animals ; Anthozoa/metabolism/*physiology ; Calcification, Physiologic/*physiology ; Chlorophyta/*physiology ; Seawater/*chemistry ; *Symbiosis ; }, abstract = {We investigated the effect of acidified seawater on calcification and symbiotic algae (zooxanthellae density, chlorophyll content per single algal cell, fluorescence yield (Fv/Fm)) on a massive coral, Porites australiensis, a common species in the Ryukyu Archipelago of Japan. We found that acidified seawater significantly decreased the calcification and fluorescence yield, but did not affect zooxanthellae density and chlorophyll content per single algal cell. This indicates low levels of photoacclimation to acidified seawater in this species, and this is contrary to the findings of previous studies of Acropora species. A significant correlation between calcification and fluorescence yield was observed, indicating the presence of a strong relationship between calcification and algal photosynthesis. Our results indicate that endosymbiont photosynthetic dysfunction may enhance the decrease of coral calcification in future acidified ocean conditions. Calcification and fluorescence yield among colonies clearly differed, showing that the response to acidified seawater is highly variable among colonies in natural coral populations.}, }
@article {pmid22114709, year = {2011}, author = {Ghinet, MG and Bordeleau, E and Beaudin, J and Brzezinski, R and Roy, S and Burrus, V}, title = {Uncovering the prevalence and diversity of integrating conjugative elements in actinobacteria.}, journal = {PloS one}, volume = {6}, number = {11}, pages = {e27846}, pmid = {22114709}, issn = {1932-6203}, mesh = {Actinobacteria/*genetics ; Chromosomes, Bacterial/*genetics ; Conjugation, Genetic/*genetics ; DNA Replication ; DNA Transposable Elements/*genetics ; DNA, Bacterial/genetics ; Genes, Bacterial ; Genome, Bacterial ; Phylogeny ; Plasmids/genetics ; Recombination, Genetic ; }, abstract = {Horizontal gene transfer greatly facilitates rapid genetic adaptation of bacteria to shifts in environmental conditions and colonization of new niches by allowing one-step acquisition of novel functions. Conjugation is a major mechanism of horizontal gene transfer mediated by conjugative plasmids and integrating conjugative elements (ICEs). While in most bacterial conjugative systems DNA translocation requires the assembly of a complex type IV secretion system (T4SS), in Actinobacteria a single DNA FtsK/SpoIIIE-like translocation protein is required. To date, the role and diversity of ICEs in Actinobacteria have received little attention. Putative ICEs were searched for in 275 genomes of Actinobacteria using HMM-profiles of proteins involved in ICE maintenance and transfer. These exhaustive analyses revealed 144 putative FtsK/SpoIIIE-type ICEs and 17 putative T4SS-type ICEs. Grouping of the ICEs based on the phylogenetic analyses of maintenance and transfer proteins revealed extensive exchanges between different sub-families of ICEs. 17 ICEs were found in Actinobacteria from the genus Frankia, globally important nitrogen-fixing microorganisms that establish root nodule symbioses with actinorhizal plants. Structural analysis of ICEs from Frankia revealed their unexpected diversity and a vast array of predicted adaptive functions. Frankia ICEs were found to excise by site-specific recombination from their host's chromosome in vitro and in planta suggesting that they are functional mobile elements whether Frankiae live as soil saprophytes or plant endosymbionts. Phylogenetic analyses of proteins involved in ICEs maintenance and transfer suggests that active exchange between ICEs cargo-borne and chromosomal genes took place within the Actinomycetales order. Functionality of Frankia ICEs in vitro as well as in planta lets us anticipate that conjugation and ICEs could allow the development of genetic manipulation tools for this challenging microorganism and for many other Actinobacteria.}, }
@article {pmid22113795, year = {2012}, author = {Van Leuven, JT and McCutcheon, JP}, title = {An AT mutational bias in the tiny GC-rich endosymbiont genome of Hodgkinia.}, journal = {Genome biology and evolution}, volume = {4}, number = {1}, pages = {24-27}, pmid = {22113795}, issn = {1759-6653}, mesh = {Adenine/*metabolism ; Bacteria/genetics ; Base Composition/*genetics ; DNA Repair ; DNA Repair-Deficiency Disorders ; DNA, Bacterial/genetics ; Gene Frequency ; Genetics, Population/methods ; *Genome, Bacterial ; *Mutation ; Polymorphism, Single Nucleotide ; Recombination, Genetic ; Symbiosis/*genetics ; Thymine/*metabolism ; }, abstract = {The fractional guanine + cytosine (GC) contents of sequenced bacterial genomes range from 13% to 75%. Despite several decades of research aimed at understanding this wide variation, the forces controlling GC content are not well understood. Recent work has suggested that a universal adenine + thymine (AT) mutational bias exists in all bacteria and that the elevated GC contents found in some bacterial genomes is due to genome-wide selection for increased GC content. These results are generally consistent with the low GC contents observed in most strict endosymbiotic bacterial genomes, where the loss of DNA repair mechanisms combined with the population genetic effects of small effective population sizes and decreased recombination should lower the efficacy of selection and shift the equilibrium GC content in the mutationally favored AT direction. Surprisingly, the two smallest bacterial genomes, Candidatus Hodgkinia cicadicola (144 kb) and Candidatus Tremblaya princeps (139 kb), have the unusual combination of highly reduced genomes and elevated GC contents, raising the possibility that these bacteria may be exceptions to the otherwise apparent universal bacterial AT mutational bias. Here, using population genomic data generated from the Hodgkinia genome project, we show that Hodgkinia has a clear AT mutational bias. These results provide further evidence that an AT mutational bias is universal in bacteria, even in strict endosymbionts with elevated genomic GC contents.}, }
@article {pmid22110767, year = {2011}, author = {Xue, HJ and Li, WZ and Nie, RE and Yang, XK}, title = {Recent speciation in three closely related sympatric specialists: inferences using multi-locus sequence, post-mating isolation and endosymbiont data.}, journal = {PloS one}, volume = {6}, number = {11}, pages = {e27834}, pmid = {22110767}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; Coleoptera/*genetics/microbiology/physiology ; Genes, Insect/genetics ; Genetic Loci/*genetics ; *Genetic Speciation ; Male ; *Phylogeny ; Plants ; *Reproductive Isolation ; Symbiosis/*genetics/physiology ; Sympatry/*genetics/physiology ; Time Factors ; Wolbachia/pathogenicity ; }, abstract = {Shifting between unrelated host plants is relatively rare for phytophagous insects, and distinct host specificity may play crucial roles in reproductive isolation. However, the isolation status and the relationship between parental divergence and post-mating isolation among closely related sympatric specialists are still poorly understood. Here, multi-locus sequence were used to estimate the relationship among three host plant-specific closely related flea beetles, Altica cirsicola, A. fragariae and A. viridicyanea (abbreviated as AC, AF and AV respectively). The tree topologies were inconsistent using different gene or different combinations of gene fragments. The relationship of AF+(AC+AV) was supported, however, by both gene tree and species tree based on concatenated data. Post-mating reproductive data on the results of crossing these three species are best interpreted in the light of a well established phylogeny. Nuclear-induced but not Wolbachia-induced unidirectional cytoplasmic incompatibility, which was detected in AC-AF and AF-AV but not in AC-AV, may also suggest more close genetic affinity between AC and AV. Prevalence of Wolbachia in these three beetles, and the endosymbiont in most individuals of AV and AC sharing a same wsp haplotype may give another evidence of AF+(AC+AV). Our study also suggested that these three flea beetles diverged in a relative short time (0.94 My), which may be the result of shifting between unrelated host plants and distinct host specificity. Incomplete post-mating isolation while almost complete lineage sorting indicated that effective pre-mating isolation among these three species should have evolved.}, }
@article {pmid22110131, year = {2012}, author = {Brown, DB and Forsberg, LS and Kannenberg, EL and Carlson, RW}, title = {Characterization of galacturonosyl transferase genes rgtA, rgtB, rgtC, rgtD, and rgtE responsible for lipopolysaccharide synthesis in nitrogen-fixing endosymbiont Rhizobium leguminosarum: lipopolysaccharide core and lipid galacturonosyl residues confer membrane stability.}, journal = {The Journal of biological chemistry}, volume = {287}, number = {2}, pages = {935-949}, pmid = {22110131}, issn = {1083-351X}, support = {R01 GM039583/GM/NIGMS NIH HHS/United States ; GM39583/GM/NIGMS NIH HHS/United States ; }, mesh = {Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics/*metabolism ; Cell Membrane/genetics/*metabolism ; Drug Resistance, Bacterial/drug effects/genetics ; Genes, Bacterial/*physiology ; Glucuronosyltransferase/genetics/*metabolism ; Lipopolysaccharides/*biosynthesis/genetics ; Mutagenesis, Insertional ; Mutation ; Polymyxin B/pharmacology ; Rhizobium leguminosarum/*enzymology/genetics ; }, abstract = {Rhizobium lipopolysaccharide (LPS) contains four terminally linked galacturonic acid (GalA) residues; one attached to the lipid A and three attached to the core oligosaccharide moiety. Attachment of the GalA residues requires the lipid donor dodecaprenyl-phosphate GalA (Dod-P-GalA), which is synthesized by the GalA transferase RgtE reported here. The galacturonosyl transferases RgtA, -B, and -C utilize Dod-P-GalA to attach GalAs on the LPS core region, and RgtD attaches GalA to the lipid A 4' position. As reported here, the functions of the rgtD and rgtE genes were determined via insertion mutagenesis and structural characterization of the mutant lipid A. The rgtE(-) mutant lacked Dod-P-GalA as determined by mass spectrometry of total lipid extracts and the inability of rgtE(-) mutant membranes to provide the substrate for heterologously expressed RgtA activity. In addition, we created single mutations in each of the rgtA, -B, -C, -D, and -E genes to study the biological function of the GalA residues. The structures of the core oligosaccharide region from each of the rgt mutants were elucidated by glycosyl linkage analysis. Each mutant was assayed for its sensitivity to sodium deoxycholate and to the antimicrobial cationic peptide, polymyxin B (PmxB). The rgt mutants were more sensitive than the parent strain to deoxycholate by varying degrees. However, the rgtA, -B, and -C mutants were more resistant to PmxB, whereas the rgtD and E mutants were less resistant in comparison to the parent strain.}, }
@article {pmid22102823, year = {2011}, author = {Lamelas, A and Gosalbes, MJ and Manzano-Marín, A and Peretó, J and Moya, A and Latorre, A}, title = {Serratia symbiotica from the aphid Cinara cedri: a missing link from facultative to obligate insect endosymbiont.}, journal = {PLoS genetics}, volume = {7}, number = {11}, pages = {e1002357}, pmid = {22102823}, issn = {1553-7404}, mesh = {Amino Acids/biosynthesis/genetics ; Animals ; Aphids/*microbiology ; Bacterial Proteins/*classification/genetics ; Biological Evolution ; Buchnera/*genetics/metabolism ; Enterobacteriaceae/*genetics/metabolism ; Genome, Bacterial/*genetics ; Metabolic Networks and Pathways/genetics ; Phylogeny ; Pseudogenes/genetics ; Riboflavin/biosynthesis/genetics ; Serratia/*genetics/metabolism ; Symbiosis/*genetics ; Tryptophan/biosynthesis/genetics ; }, abstract = {The genome sequencing of Buchnera aphidicola BCc from the aphid Cinara cedri, which is the smallest known Buchnera genome, revealed that this bacterium had lost its symbiotic role, as it was not able to synthesize tryptophan and riboflavin. Moreover, the biosynthesis of tryptophan is shared with the endosymbiont Serratia symbiotica SCc, which coexists with B. aphidicola in this aphid. The whole-genome sequencing of S. symbiotica SCc reveals an endosymbiont in a stage of genome reduction that is closer to an obligate endosymbiont, such as B. aphidicola from Acyrthosiphon pisum, than to another S. symbiotica, which is a facultative endosymbiont in this aphid, and presents much less gene decay. The comparison between both S. symbiotica enables us to propose an evolutionary scenario of the transition from facultative to obligate endosymbiont. Metabolic inferences of B. aphidicola BCc and S. symbiotica SCc reveal that most of the functions carried out by B. aphidicola in A. pisum are now either conserved in B. aphidicola BCc or taken over by S. symbiotica. In addition, there are several cases of metabolic complementation giving functional stability to the whole consortium and evolutionary preservation of the actors involved.}, }
@article {pmid22094859, year = {2011}, author = {Neef, A and Latorre, A and Peretó, J and Silva, FJ and Pignatelli, M and Moya, A}, title = {Genome economization in the endosymbiont of the wood roach Cryptocercus punctulatus due to drastic loss of amino acid synthesis capabilities.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {1437-1448}, pmid = {22094859}, issn = {1759-6653}, mesh = {Amino Acids/*biosynthesis ; Animals ; Bacteroidetes/*genetics/physiology ; Cockroaches/*microbiology/physiology ; Endophytes/*genetics/isolation &amp; purification/physiology ; Female ; Genome Size ; *Genome, Bacterial ; Male ; Molecular Sequence Data ; *Symbiosis ; }, abstract = {Cockroaches (Blattaria: Dictyoptera) harbor the endosymbiont Blattabacterium sp. in their abdominal fat body. This endosymbiont is involved in nitrogen recycling and amino acid provision to its host. In this study, the genome of Blattabacterium sp. of Cryptocercus punctulatus (BCpu) was sequenced and compared with those of the symbionts of Blattella germanica and Periplaneta americana, BBge and BPam, respectively. The BCpu genome consists of a chromosome of 605.7 kb and a plasmid of 3.8 kb and is therefore approximately 31 kb smaller than the other two aforementioned genomes. The size reduction is due to the loss of 55 genes, 23 of which belong to biosynthetic pathways for amino acids. The pathways for the production of tryptophan, leucine, isoleucine/threonine/valine, methionine, and cysteine have been completely lost. Additionally, the genes for the enzymes catalyzing the last steps of arginine and lysine biosynthesis, argH and lysA, were found to be missing and pseudogenized, respectively. These gene losses render BCpu auxotrophic for nine amino acids more than those corresponding to BBge and BPam. BCpu has also lost capacities for sulfate reduction, production of heme groups, as well as genes for several other unlinked metabolic processes, and genes present in BBge and BPam in duplicates. Amino acids and cofactors that are not synthesized by BCpu are either produced in abundance by hindgut microbiota or are provisioned via a copious diet of dampwood colonized by putrefying microbiota, supplying host and Blattabacterium symbiont with the necessary nutrients and thus permitting genome economization of BCpu.}, }
@article {pmid22085419, year = {2011}, author = {Biliske, JA and Batista, PD and Grant, CL and Harris, HL}, title = {The bacteriophage WORiC is the active phage element in wRi of Drosophila simulans and represents a conserved class of WO phages.}, journal = {BMC microbiology}, volume = {11}, number = {}, pages = {251}, pmid = {22085419}, issn = {1471-2180}, mesh = {Animals ; Bacteriophages/*genetics/physiology ; DNA, Viral/genetics ; Drosophila/*microbiology ; Female ; Genome, Viral ; Larva/microbiology ; Male ; Phylogeny ; Prophages/*genetics/physiology ; Sequence Analysis, DNA ; Virus Replication ; Wolbachia/*virology ; }, abstract = {BACKGROUND: The alphaproteobacterium Wolbachia pipientis, the most common endosymbiont in eukaryotes, is found predominantly in insects including many Drosophila species. Although Wolbachia is primarily vertically transmitted, analysis of its genome provides evidence for frequent horizontal transfer, extensive recombination and numerous mobile genetic elements. The genome sequence of Wolbachia in Drosophila simulans Riverside (wRi) is available along with the integrated bacteriophages, enabling a detailed examination of phage genes and the role of these genes in the biology of Wolbachia and its host organisms. Wolbachia is widely known for its ability to modify the reproductive patterns of insects. One particular modification, cytoplasmic incompatibility, has previously been shown to be dependent on Wolbachia density and inversely related to the titer of lytic phage. The wRi genome has four phage regions, two WORiBs, one WORiA and one WORiC.<br><br>RESULTS: In this study specific primers were designed to distinguish between these four prophage types in wRi, and quantitative PCR was used to measure the titer of bacteriophages in testes, ovaries, embryos and adult flies. In all tissues tested, WORiA and WORiB were not found to be present in excess of their integrated prophages; WORiC, however, was found to be present extrachromosomally. WORiC is undergoing extrachromosomal replication in wRi. The density of phage particles was found to be consistent in individual larvae in a laboratory population. The WORiC genome is organized in conserved blocks of genes and aligns most closely with other known lytic WO phages, WOVitA and WOCauB.<br><br>CONCLUSIONS: The results presented here suggest that WORiC is the lytic form of WO in D. simulans, is undergoing extrachromosomal replication in wRi, and belongs to a conserved family of phages in Wolbachia.}, }
@article {pmid22072980, year = {2011}, author = {Pontes, MH and Smith, KL and De Vooght, L and Van Den Abbeele, J and Dale, C}, title = {Attenuation of the sensing capabilities of PhoQ in transition to obligate insect-bacterial association.}, journal = {PLoS genetics}, volume = {7}, number = {11}, pages = {e1002349}, pmid = {22072980}, issn = {1553-7404}, mesh = {Adenosine Triphosphatases/genetics ; Alleles ; Animals ; Antimicrobial Cationic Peptides/pharmacology ; Bacterial Proteins/*genetics ; Base Sequence ; Biological Evolution ; Enterobacteriaceae/drug effects/genetics/*physiology ; Escherichia coli/genetics ; Gene Expression Regulation, Bacterial ; Host Specificity/genetics ; Lipid A/metabolism ; Magnesium/*metabolism ; Membrane Transport Proteins/genetics ; Molecular Sequence Data ; Mutation ; Promoter Regions, Genetic ; Salmonella enterica/*genetics ; Symbiosis/genetics ; Transcriptional Activation ; Tsetse Flies/*microbiology ; }, abstract = {Sodalis glossinidius, a maternally inherited endosymbiont of the tsetse fly, maintains genes encoding homologues of the PhoP-PhoQ two-component regulatory system. This two-component system has been extensively studied in facultative bacterial pathogens and is known to serve as an environmental magnesium sensor and a regulator of key virulence determinants. In the current study, we show that the inactivation of the response regulator, phoP, renders S. glossinidius sensitive to insect derived cationic antimicrobial peptides (AMPs). The resulting mutant strain displays reduced expression of genes involved in the structural modification of lipid A that facilitates resistance to AMPs. In addition, the inactivation of phoP alters the expression of type-III secretion system (TTSS) genes encoded within three distinct chromosomal regions, indicating that PhoP-PhoQ also serves as a master regulator of TTSS gene expression. In the absence of phoP, S. glossinidius is unable to superinfect either its natural tsetse fly host or a closely related hippoboscid louse fly. Furthermore, we show that the S. glossinidius PhoQ sensor kinase has undergone functional adaptations that result in a substantially diminished ability to sense ancestral signals. The loss of PhoQ's sensory capability is predicted to represent a novel adaptation to the static symbiotic lifestyle, allowing S. glossinidius to constitutively express genes that facilitate resistance to host derived AMPs.}, }
@article {pmid22072969, year = {2011}, author = {Landmann, F and Voronin, D and Sullivan, W and Taylor, MJ}, title = {Anti-filarial activity of antibiotic therapy is due to extensive apoptosis after Wolbachia depletion from filarial nematodes.}, journal = {PLoS pathogens}, volume = {7}, number = {11}, pages = {e1002351}, pmid = {22072969}, issn = {1553-7374}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology/therapeutic use ; *Apoptosis ; Brugia malayi/cytology/drug effects/metabolism/*microbiology ; Caspase 3/biosynthesis ; Doxycycline/pharmacology ; Female ; Filariasis/drug therapy/*parasitology ; Gerbillinae/parasitology ; Helminth Proteins/biosynthesis ; Humans ; In Situ Nick-End Labeling ; Larva/microbiology ; Male ; Symbiosis ; Tetracycline/pharmacology ; Wolbachia/*drug effects/*physiology ; }, abstract = {Filarial nematodes maintain a mutualistic relationship with the endosymbiont Wolbachia. Depletion of Wolbachia produces profound defects in nematode development, fertility and viability and thus has great promise as a novel approach for treating filarial diseases. However, little is known concerning the basis for this mutualistic relationship. Here we demonstrate using whole mount confocal microscopy that an immediate response to Wolbachia depletion is extensive apoptosis in the adult germline, and in the somatic cells of the embryos, microfilariae and fourth-stage larvae (L4). Surprisingly, apoptosis occurs in the majority of embryonic cells that had not been infected prior to antibiotic treatment. In addition, no apoptosis occurs in the hypodermal chords, which are populated with large numbers of Wolbachia, although disruption of the hypodermal cytoskeleton occurs following their depletion. Thus, the induction of apoptosis upon Wolbachia depletion is non-cell autonomous and suggests the involvement of factors originating from Wolbachia in the hypodermal chords. The pattern of apoptosis correlates closely with the nematode tissues and processes initially perturbed following depletion of Wolbachia, embryogenesis and long-term sterilization, which are sustained for several months until the premature death of the adult worms. Our observations provide a cellular mechanism to account for the sustained reductions in microfilarial loads and interruption of transmission that occurs prior to macrofilaricidal activity following antibiotic therapy of filarial nematodes.}, }
@article {pmid22069350, year = {2011}, author = {Babalola, OE}, title = {Ocular onchocerciasis: current management and future prospects.}, journal = {Clinical ophthalmology (Auckland, N.Z.)}, volume = {5}, number = {}, pages = {1479-1491}, pmid = {22069350}, issn = {1177-5483}, abstract = {This paper reviews the current management of onchocerciasis and its future prospects. Onchocerciasis is a disease affecting millions of people in Africa, South and Central America, and Yemen. It is spread by the blackfly as a vector and caused by the filarial nematode, Onchocerca volvulus. A serious attempt was made by the Onchocerciasis Control Program between 1975 and 2002 to eliminate the vector in eleven of the endemic countries in West Africa, and with remarkable success. Formerly, the treatment was with diethyl carbamazine for the microfilaria and suramin for the adult worm. These drugs are now known to be toxic and unsuitable for mass distribution. In particular, they precipitate optic nerve disease. With the discovery of ivermectin, a much safer microfilaricide, and the decision of Merck to distribute the drug free of charge for as long as needed, the strategy of control switched to mass drug administration through community-directed treatment with ivermectin. So far, millions have received this annual or biannual treatment through the African Program for Onchocerciasis Control and the Onchocerciasis Elimination Program for the Americas. However, the problem with ivermectin is that it is a monotherapy microfilaricide which has limited effect on the adult worm, and thus will need to be continued for the life span of the adult worm, which may last up to 15 years. There are also early reports of resistance. Serious encephalopathy and death may occur when ivermectin is used in subjects heavily infested with loiasis. It seems unlikely that a break in transmission will occur with community-directed treatment with ivermectin in Africa because of population migrations and the highly efficient vector, but in the Americas some countries such as Columbia and the Oaxaca focus in Mexico have reported eradication. Vector control is only now applicable in selected situations, and particularly to control the nuisance value of the blackfly. Trials are ongoing for alternatives to ivermectin. Candidate drugs include moxidectin, a macrofilaricide, doxycycline which targets the Wolbachia endosymbiont, and flubendazole, which shows promise with the newer oral cyclodextrin formulation.}, }
@article {pmid22056929, year = {2012}, author = {Gillespie, JJ and Joardar, V and Williams, KP and Driscoll, T and Hostetler, JB and Nordberg, E and Shukla, M and Walenz, B and Hill, CA and Nene, VM and Azad, AF and Sobral, BW and Caler, E}, title = {A Rickettsia genome overrun by mobile genetic elements provides insight into the acquisition of genes characteristic of an obligate intracellular lifestyle.}, journal = {Journal of bacteriology}, volume = {194}, number = {2}, pages = {376-394}, pmid = {22056929}, issn = {1098-5530}, support = {R01 AI017828/AI/NIAID NIH HHS/United States ; HHSN272200900040C/AI/NIAID NIH HHS/United States ; R01AI017828/AI/NIAID NIH HHS/United States ; R01AI59118/AI/NIAID NIH HHS/United States ; HHSN266200400038C//PHS HHS/United States ; R01 AI059118/AI/NIAID NIH HHS/United States ; N01-AI-33071/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Arachnid Vectors/microbiology ; Biological Evolution ; Chromosome Mapping ; Chromosomes, Bacterial ; Gene Expression Regulation, Bacterial/*physiology ; *Genome, Bacterial ; *Interspersed Repetitive Sequences ; Ixodes/*microbiology ; Molecular Sequence Data ; Plasmids ; Rickettsia/*genetics ; Symbiosis ; }, abstract = {We present the draft genome for the Rickettsia endosymbiont of Ixodes scapularis (REIS), a symbiont of the deer tick vector of Lyme disease in North America. Among Rickettsia species (Alphaproteobacteria: Rickettsiales), REIS has the largest genome sequenced to date (>2 Mb) and contains 2,309 genes across the chromosome and four plasmids (pREIS1 to pREIS4). The most remarkable finding within the REIS genome is the extraordinary proliferation of mobile genetic elements (MGEs), which contributes to a limited synteny with other Rickettsia genomes. In particular, an integrative conjugative element named RAGE (for Rickettsiales amplified genetic element), previously identified in scrub typhus rickettsiae (Orientia tsutsugamushi) genomes, is present on both the REIS chromosome and plasmids. Unlike the pseudogene-laden RAGEs of O. tsutsugamushi, REIS encodes nine conserved RAGEs that include F-like type IV secretion systems similar to that of the tra genes encoded in the Rickettsia bellii and R. massiliae genomes. An unparalleled abundance of encoded transposases (>650) relative to genome size, together with the RAGEs and other MGEs, comprise ~35% of the total genome, making REIS one of the most plastic and repetitive bacterial genomes sequenced to date. We present evidence that conserved rickettsial genes associated with an intracellular lifestyle were acquired via MGEs, especially the RAGE, through a continuum of genomic invasions. Robust phylogeny estimation suggests REIS is ancestral to the virulent spotted fever group of rickettsiae. As REIS is not known to invade vertebrate cells and has no known pathogenic effects on I. scapularis, its genome sequence provides insight on the origin of mechanisms of rickettsial pathogenicity.}, }
@article {pmid22038605, year = {2012}, author = {Lemaire, B and Janssens, S and Smets, E and Dessein, S}, title = {Endosymbiont transmission mode in bacterial leaf nodulation as revealed by a population genetic study of Psychotria leptophylla.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {1}, pages = {284-287}, pmid = {22038605}, issn = {1098-5336}, mesh = {Bayes Theorem ; Burkholderia/*genetics ; Cameroon ; DNA Gyrase/genetics ; DNA, Bacterial/analysis ; Genetics, Population ; Host Specificity/*genetics ; Likelihood Functions ; Phylogeny ; Polymerase Chain Reaction ; Psychotria/genetics/*microbiology ; Symbiosis/*genetics ; }, abstract = {Leaf-nodulated plants are colonized by vertically inherited bacterial endosymbionts, which maintain symbioses throughout host generations. The permanent character of the interaction implies phylogenetic congruence between the host and the endosymbiont. However, the present population genetic study of Psychotria leptophylla provides evidence for a mixed symbiont transmission involving both vertical inheritance and horizontal transfers from the environment.}, }
@article {pmid22032328, year = {2012}, author = {McNulty, SN and Fischer, K and Mehus, JO and Vaughan, JA and Tkach, VV and Weil, GJ and Fischer, PU}, title = {Absence of Wolbachia endobacteria in Chandlerella quiscali, an avian filarial parasite.}, journal = {The Journal of parasitology}, volume = {98}, number = {2}, pages = {382-387}, pmid = {22032328}, issn = {1937-2345}, support = {R03 AI092306/AI/NIAID NIH HHS/United States ; T32 AI007172/AI/NIAID NIH HHS/United States ; T32-AI007172/AI/NIAID NIH HHS/United States ; R03-AI092306/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antigens, Surface/immunology ; Bacterial Proteins/immunology ; Bird Diseases/*parasitology ; DNA, Bacterial/chemistry ; DNA, Helminth/chemistry ; DNA, Ribosomal/chemistry ; Female ; Filariasis/parasitology/*veterinary ; Filarioidea/classification/genetics/*microbiology ; Immunohistochemistry/veterinary ; In Situ Hybridization/veterinary ; Male ; Molecular Sequence Data ; Passeriformes/*parasitology ; Polymerase Chain Reaction/veterinary ; RNA, Bacterial/genetics ; RNA, Helminth/chemistry ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 5S/chemistry ; Wolbachia/genetics/immunology/*physiology ; }, abstract = {Chandlerella quiscali is a filarial nematode parasite of the common grackle (Quiscalus quiscula), a widespread bird species found throughout most of North America. Worms collected from wild-caught birds were morphologically identified as C. quiscali and tested for the presence of Wolbachia, an alphaproteobacterial endosymbiont required for reproduction and maturation by many filarial species. Although various methods, including polymerase chain reaction, in situ hybridization, and immunohistology, were used, we were unable to detect evidence of colonization with Wolbachia. Due to the widespread distribution of the grackle host, localization within the host, and high prevalence, C. quiscali may be among the most easily obtainable of Wolbachia-free filarial species. Further studies of C. quiscali and other Wolbachia-free filarial species may help to clarify the reason(s) that some filarial species require Wolbachia but others do not.}, }
@article {pmid22023445, year = {2011}, author = {Striepen, B}, title = {The apicoplast: a red alga in human parasites.}, journal = {Essays in biochemistry}, volume = {51}, number = {}, pages = {111-125}, doi = {10.1042/bse0510111}, pmid = {22023445}, issn = {1744-1358}, support = {AI084415/AI/NIAID NIH HHS/United States ; AI64671/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Apicomplexa/*cytology/*pathogenicity/*physiology ; Biological Evolution ; Chloroplasts/metabolism ; Humans ; Organelles/*physiology ; Photosynthesis ; Protozoan Infections/*parasitology ; Rhodophyta/*cytology ; }, abstract = {Surprisingly, some of the world's most dangerous parasites appear to have had a benign photosynthetic past in the ocean. The phylum Apicomplexa includes the causative agents of malaria and a number of additional human and animal diseases. These diseases threaten the life and health of hundreds of millions each year and pose a tremendous challenge to public health. Recent findings suggest that Apicomplexa share their ancestry with diatoms and kelps, and that a key event in their evolution was the acquisition of a red algal endosymbiont. A remnant of this endosymbiont is still present today, albeit reduced to a small chloroplast-like organelle, the apicoplast. In the present chapter, I introduce the remarkably complex biology of this organelle. The apicoplast is bounded by four membranes, and these membranes trace their ancestry to three different organisms. Intriguingly, this divergent ancestry is still reflected in their molecular makeup and function. We also pursue the raison d'être of the apicoplast. Why did Apicomplexa retain a chloroplast when they abandoned photosynthesis for a life as obligate parasites? The answer to this question appears to lie in the profound metabolic dependence of the parasite on its endosymbiont. This dependence may prove to be a liability to the parasite. As humans lack chloroplasts, the apicoplast has become one of the prime targets for the development of parasite-specific drugs.}, }
@article {pmid22022599, year = {2011}, author = {Verspoor, RL and Haddrill, PR}, title = {Genetic diversity, population structure and Wolbachia infection status in a worldwide sample of Drosophila melanogaster and D. simulans populations.}, journal = {PloS one}, volume = {6}, number = {10}, pages = {e26318}, pmid = {22022599}, issn = {1932-6203}, mesh = {Animals ; Drosophila/*genetics/*microbiology ; Drosophila melanogaster/*genetics/*microbiology ; Female ; *Genetic Variation ; Genetics, Population ; Gram-Negative Bacterial Infections/microbiology ; Microsatellite Repeats/genetics ; Symbiosis/genetics ; Wolbachia/*physiology ; }, abstract = {Drosophila melanogaster and its close relatives have been extremely important model species in the development of population genetic models that serve to explain patterns of diversity in natural populations, a major goal of evolutionary biology. A detailed picture of the evolutionary history of these species is beginning to emerge, as the relative importance of forces including demographic changes and natural selection is established. A continuing aim is to characterise levels of genetic diversity in a large number of populations of these species, covering a wide geographic area. We have used collections from five previously un-sampled wild populations of D. melanogaster and two of D. simulans, across three continents. We estimated levels of genetic diversity within, and divergence between, these populations, and looked for evidence of genetic structure both between ancestral and derived populations, and amongst derived populations. We also investigated the prevalence of infection with the bacterial endosymbiont Wolbachia. We found that D. melanogaster populations from Sub-Saharan Africa are the most diverse, and that divergence is highest between these and non-Sub-Saharan populations. There is strong evidence for structuring of populations between Sub-Saharan Africa and the rest of the world, and some evidence for weak structure amongst derived populations. Populations from Sub-Saharan Africa also differ in the prevalence of Wolbachia infection, with very low levels of infection compared to populations from the rest of the world.}, }
@article {pmid22021855, year = {2011}, author = {Login, FH and Balmand, S and Vallier, A and Vincent-Monégat, C and Vigneron, A and Weiss-Gayet, M and Rochat, D and Heddi, A}, title = {Antimicrobial peptides keep insect endosymbionts under control.}, journal = {Science (New York, N.Y.)}, volume = {334}, number = {6054}, pages = {362-365}, doi = {10.1126/science.1209728}, pmid = {22021855}, issn = {1095-9203}, mesh = {Animals ; Bacterial Outer Membrane Proteins/metabolism ; Bacterial Proteins/metabolism ; Chaperonin 60/genetics/metabolism ; Cytoplasm/metabolism ; Epithelial Cells/metabolism ; Escherichia coli/cytology/drug effects ; Fat Body/metabolism ; Gammaproteobacteria/cytology/drug effects/metabolism/*physiology ; Insect Proteins/genetics/*metabolism/pharmacology ; Micrococcus luteus/drug effects ; Oocytes/metabolism ; RNA Interference ; Saccharomyces cerevisiae/drug effects ; *Symbiosis ; Weevils/cytology/*metabolism/*microbiology ; }, abstract = {Vertically transmitted endosymbionts persist for millions of years in invertebrates and play an important role in animal evolution. However, the functional basis underlying the maintenance of these long-term resident bacteria is unknown. We report that the weevil coleoptericin-A (ColA) antimicrobial peptide selectively targets endosymbionts within the bacteriocytes and regulates their growth through the inhibition of cell division. Silencing the colA gene with RNA interference resulted in a decrease in size of the giant filamentous endosymbionts, which escaped from the bacteriocytes and spread into insect tissues. Although this family of peptides is commonly linked with microbe clearance, this work shows that endosymbiosis benefits from ColA, suggesting that long-term host-symbiont coevolution might have shaped immune effectors for symbiont maintenance.}, }
@article {pmid22020505, year = {2012}, author = {Sabree, ZL and Huang, CY and Arakawa, G and Tokuda, G and Lo, N and Watanabe, H and Moran, NA}, title = {Genome shrinkage and loss of nutrient-providing potential in the obligate symbiont of the primitive termite Mastotermes darwiniensis.}, journal = {Applied and environmental microbiology}, volume = {78}, number = {1}, pages = {204-210}, pmid = {22020505}, issn = {1098-5336}, mesh = {Animals ; Bacterial Physiological Phenomena ; Base Sequence ; DNA, Bacterial/analysis ; Flavobacteriaceae/*genetics/physiology ; *Genome Size ; *Genome, Bacterial ; Isoptera/*microbiology ; Metagenome/genetics ; Molecular Sequence Data ; Phylogeny ; Selection, Genetic ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Beneficial microbial associations with insects are common and are classified as either one or a few intracellular species that are vertically transmitted and reside intracellularly within specialized organs or as microbial assemblages in the gut. Cockroaches and termites maintain at least one if not both beneficial associations. Blattabacterium is a flavobacterial endosymbiont of nearly all cockroaches and the termite Mastotermes darwiniensis and can use nitrogenous wastes in essential amino acid and vitamin biosynthesis. Key changes during the evolutionary divergence of termites from cockroaches are loss of Blattabacterium, diet shift to wood, acquisition of a specialized hindgut microbiota, and establishment of advanced social behavior. Termite gut microbes collaborate to fix nitrogen, degrade lignocellulose, and produce nutrients, and the absence of Blattabacterium in nearly all termites suggests that its nutrient-provisioning role has been replaced by gut microbes. M. darwiniensis is a basal, extant termite that solely retains Blattabacterium, which would show evidence of relaxed selection if it is being supplanted by the gut microbiome. This termite-associated Blattabacterium genome is ∼8% smaller than cockroach-associated Blattabacterium genomes and lacks genes underlying vitamin and essential amino acid biosynthesis. Furthermore, the M. darwiniensis gut microbiome membership is more consistent between individuals and includes specialized termite gut-associated bacteria, unlike the more variable membership of cockroach gut microbiomes. The M. darwiniensis Blattabacterium genome may reflect relaxed selection for some of its encoded functions, and the loss of this endosymbiont in all remaining termite genera may result from its replacement by a functionally complementary gut microbiota.}, }
@article {pmid22017975, year = {2011}, author = {Miyagishima, SY and Nakanishi, H and Kabeya, Y}, title = {Structure, regulation, and evolution of the plastid division machinery.}, journal = {International review of cell and molecular biology}, volume = {291}, number = {}, pages = {115-153}, doi = {10.1016/B978-0-12-386035-4.00004-5}, pmid = {22017975}, issn = {1937-6448}, mesh = {Archaeal Proteins/classification/genetics/metabolism ; Bacterial Proteins/classification/genetics/metabolism ; *Biological Evolution ; Cell Division/physiology ; Cytoskeletal Proteins/classification/genetics/metabolism ; Dynamins/classification/genetics/metabolism ; Genome ; Mitochondria/physiology/ultrastructure ; Phylogeny ; Plastids/*physiology/ultrastructure ; Symbiosis ; }, abstract = {Plastids have evolved from a cyanobacterial endosymbiont, and their continuity is maintained by the plastid division and segregation which is regulated by the eukaryotic host cell. Plastids divide by constriction of the inner- and outer-envelope membranes. Recent studies revealed that this constriction is performed by a large protein and glucan complex at the division site that spans the two envelope membranes. The division complex has retained certain components of the cyanobacterial division complex along with components developed by the host cell. Based on the information on the division complex at the molecular level, we are beginning to understand how the division complex has evolved and how it is assembled, constricted, and regulated in the host cell. This chapter reviews the current understanding of the plastid division machinery and some of the questions that will be addressed in the near future.}, }
@article {pmid22016847, year = {2011}, author = {Hampl, V and Stairs, CW and Roger, AJ}, title = {The tangled past of eukaryotic enzymes involved in anaerobic metabolism.}, journal = {Mobile genetic elements}, volume = {1}, number = {1}, pages = {71-74}, pmid = {22016847}, issn = {2159-2543}, abstract = {There is little doubt that genes can spread across unrelated prokaryotes, eukaryotes and even between these domains. It is expected that organisms inhabiting a common niche may exchange their genes even more often due to their physical proximity and similar demands. One such niche is anaerobic or microaerophilic environments in some sediments and intestines of animals. Indeed, enzymes advantageous for metabolism in these environments often exhibit an evolutionary history incoherent with the history of their hosts indicating potential transfers. The evolutionary paths of some very basic enzymes for energy metabolism of anaerobic eukaryotes (pyruvate formate lyase, pyruvate:ferredoxin oxidoreductase, [FeFe]hydrogenase and arginine deiminase) seems to be particularly intriguing and although their histories are not identical they share several unexpected features in common. Every enzyme mentioned above is present in groups of eukaryotes that are unrelated to each other. Although the enzyme phylogenies are not always robustly supported, they always suggest that the eukaryotic homologues form one or two clades, in which the relationships are not congruent with the eukaryotic phylogeny. Finally, these eukaryotic enzymes are never specifically related to homologues from α-proteobacteria, ancestors of mitochondria. The most plausible explanation for evolution of this pattern expects one or two interdomain transfers to one or two eukaryotes from prokaryotes, who were not the mitochondrial endosymbiont. Once the genes were introduced into the eukaryotic domain they have spread to other eukaryotic groups exclusively via eukaryote-to-eukaryote transfers. Currently, eukaryote-to-eukaryote gene transfers have been regarded as less common than prokaryote-to-eukaryote transfers. The fact that eukaryotes accepted genes for these enzymes solely from other eukaryotes and not prokaryotes present in the same environment is surprising.}, }
@article {pmid22016840, year = {2011}, author = {Biondi, EG and Toro, N and Bazzicalupo, M and Martínez-Abarca, F}, title = {Spread of the group II intron RmInt1 and its insertion sequence target sites in the plant endosymbiont Sinorhizobium meliloti.}, journal = {Mobile genetic elements}, volume = {1}, number = {1}, pages = {2-7}, pmid = {22016840}, issn = {2159-2543}, abstract = {RmInt1 is a mobile group II intron from Sinorhizobium meliloti that is exceptionally abundant in this bacterial species. We compared the presence of RmInt1 and two of its insertion sequence homing sites (ISRm2011-2 and ISRm10-2) in two phylogenetic clusters (I and II) identified by AFLP analysis in a collection of S. meliloti field isolates from Italy. Both clusters contained several copies of the ISRm2011-2 element, which is present at high copy number in almost all S. meliloti isolates. By contrast, isolates from cluster I harbored no copies of ISRm10-2 and only a truncated copy of RmInt1, despite the absence of constraints on intron mobility in this genetic background, whereas cluster II strains harbored several copies of this intron. The absence of ISRm10-2 from one of the strains of this cluster suggests that this element was acquired more recently than the other two elements. Furthermore, studies of insertional polymorphisms in cluster II strains revealed the acquisition of ISRm10-2 and subsequent retrohoming of RmInt1 to this homing site. These results highlight the role of intron homing sites (ISs) in facilitating intron dispersal and the dynamic and ongoing nature of the spread of the group II intron RmInt1 in S. meliloti.}, }
@article {pmid22014084, year = {2011}, author = {Georgiades, K and Raoult, D}, title = {The rhizome of Reclinomonas americana, Homo sapiens, Pediculus humanus and Saccharomyces cerevisiae mitochondria.}, journal = {Biology direct}, volume = {6}, number = {}, pages = {55}, pmid = {22014084}, issn = {1745-6150}, mesh = {Alphaproteobacteria/genetics/metabolism ; Animals ; *Evolution, Molecular ; Gene Transfer, Horizontal ; *Genes, Bacterial ; Genes, Fungal ; *Genes, Mitochondrial ; Genome, Human ; Humans ; Mitochondria/*genetics/metabolism ; Pediculus/*genetics/metabolism ; Phylogeny ; Ribosomal Proteins/genetics/metabolism ; Ribosomes/genetics/metabolism ; Saccharomyces cerevisiae/*genetics/metabolism ; }, abstract = {BACKGROUND: Mitochondria are thought to have evolved from eubacteria-like endosymbionts; however, the origin of the mitochondrion remains a subject of debate. In this study, we investigated the phenomenon of chimerism in mitochondria to shed light on the origin of these organelles by determining which species played a role in their formation. We used the mitochondria of four distinct organisms, Reclinomonas americana, Homo sapiens, Saccharomyces cerevisiae and multichromosome Pediculus humanus, and attempted to identify the origin of each mitochondrial gene.<br><br>RESULTS: Our results suggest that the origin of mitochondrial genes is not limited to the Rickettsiales and that the creation of these genes did not occur in a single event, but through multiple successive events. Some of these events are very old and were followed by events that are more recent and occurred through the addition of elements originating from current species. The points in time that the elements were added and the parental species of each gene in the mitochondrial genome are different to the individual species. These data constitute strong evidence that mitochondria do not have a single common ancestor but likely have numerous ancestors, including proto-Rickettsiales, proto-Rhizobiales and proto-Alphaproteobacteria, as well as current alphaproteobacterial species. The analysis of the multichromosome P. humanus mitochondrion supports this mechanism.<br><br>CONCLUSIONS: The most plausible scenario of the origin of the mitochondrion is that ancestors of Rickettsiales and Rhizobiales merged in a proto-eukaryotic cell approximately one billion years ago. The fusion of the Rickettsiales and Rhizobiales cells was followed by gene loss, genomic rearrangements and the addition of alphaproteobacterial elements through ancient and more recent recombination events. Each gene of each of the four studied mitochondria has a different origin, while in some cases, multichromosomes may allow for enhanced gene exchange. Therefore, the tree of life is not sufficient to explain the chimeric structure of current genomes, and the theory of a single common ancestor and a top-down tree does not reflect our current state of knowledge. Mitochondrial evolution constitutes a rhizome, and it should be represented as such.}, }
@article {pmid22012236, year = {2011}, author = {de Albuquerque, AL and Magalhães, T and Ayres, CF}, title = {High prevalence and lack of diversity of Wolbachia pipientis in Aedes albopictus populations from Northeast Brazil.}, journal = {Memorias do Instituto Oswaldo Cruz}, volume = {106}, number = {6}, pages = {773-776}, doi = {10.1590/s0074-02762011000600021}, pmid = {22012236}, issn = {1678-8060}, mesh = {Aedes/*microbiology ; Animals ; *Genetic Variation/genetics ; Insect Vectors/*microbiology ; Polymerase Chain Reaction ; Prevalence ; Wolbachia/*genetics/isolation &amp; purification ; }, abstract = {The use of Wolbachia as a tool to control insect vectors has recently been suggested. In this context, studies on the prevalence and diversity of this bacterium in wild populations are relevant. Here, we evaluated the diversity of two Wolbachiagenes (ftsZ and wsp) and the prevalence of this endosymbiont in wild Aedes albopictus. Using semi-nested polymerase chain reaction, our results showed that 99.3% of the individuals were superinfected with Wolbachia. In regards to genetic diversity, the two genes showed no variation within or among mosquito populations. An analysis of other Wolbachia markers may help to clarify the relationship between insect and endosymbiont.}, }
@article {pmid22011719, year = {2012}, author = {Gardebrecht, A and Markert, S and Sievert, SM and Felbeck, H and Thürmer, A and Albrecht, D and Wollherr, A and Kabisch, J and Le Bris, N and Lehmann, R and Daniel, R and Liesegang, H and Hecker, M and Schweder, T}, title = {Physiological homogeneity among the endosymbionts of Riftia pachyptila and Tevnia jerichonana revealed by proteogenomics.}, journal = {The ISME journal}, volume = {6}, number = {4}, pages = {766-776}, pmid = {22011719}, issn = {1751-7370}, mesh = {Animals ; Bacteria/*classification/*metabolism ; Carbon Cycle ; Metagenomics/methods ; Polychaeta/*microbiology/*physiology ; Proteomics/methods ; Symbiosis ; }, abstract = {The two closely related deep-sea tubeworms Riftia pachyptila and Tevnia jerichonana both rely exclusively on a single species of sulfide-oxidizing endosymbiotic bacteria for their nutrition. They do, however, thrive in markedly different geochemical conditions. A detailed proteogenomic comparison of the endosymbionts coupled with an in situ characterization of the geochemical environment was performed to investigate their roles and expression profiles in the two respective hosts. The metagenomes indicated that the endosymbionts are genotypically highly homogeneous. Gene sequences coding for enzymes of selected key metabolic functions were found to be 99.9% identical. On the proteomic level, the symbionts showed very consistent metabolic profiles, despite distinctly different geochemical conditions at the plume level of the respective hosts. Only a few minor variations were observed in the expression of symbiont enzymes involved in sulfur metabolism, carbon fixation and in the response to oxidative stress. Although these changes correspond to the prevailing environmental situation experienced by each host, our data strongly suggest that the two tubeworm species are able to effectively attenuate differences in habitat conditions, and thus to provide their symbionts with similar micro-environments.}, }
@article {pmid22006824, year = {2011}, author = {White, JA}, title = {Caught in the act: rapid, symbiont-driven evolution: endosymbiont infection is a mechanism generating rapid evolution in some arthropods--but how widespread is the phenomenon?.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {33}, number = {11}, pages = {823-829}, doi = {10.1002/bies.201100095}, pmid = {22006824}, issn = {1521-1878}, mesh = {Animals ; Arthropods/genetics/*microbiology/physiology ; Bacteria/*growth &amp; development/pathogenicity ; *Biological Evolution ; Female ; Gene Transfer, Horizontal ; Male ; Phenotype ; Reproduction ; Selection, Genetic ; *Symbiosis ; }, abstract = {Facultative bacterial endosymbionts can transfer horizontally among lineages of their arthropod hosts, providing the recipient with a suite of traits that can lead to rapid evolutionary response, as has been recently demonstrated. But how common is symbiont-driven evolution? Evidence suggests that successful symbiont transfers are most likely within a species or among closely related species, although more distant transfers have occurred over evolutionary history. Symbiont-driven evolution need not be a function of a recent horizontal transfer, however. Many endosymbionts infect only a small proportion of a host population, but could quickly increase in frequency under favorable selection regimes. Some host species appear to accumulate a diversity of facultative endosymbionts, and it is among these species that symbiont-driven evolution should be most prevalent. It remains to be determined how frequently symbionts enable rapid evolutionary response by their hosts, but substantial ecological effects are a likely consequence whenever it does occur.}, }
@article {pmid22004364, year = {2011}, author = {Bongaerts, P and Riginos, C and Hay, KB and van Oppen, MJ and Hoegh-Guldberg, O and Dove, S}, title = {Adaptive divergence in a scleractinian coral: physiological adaptation of Seriatopora hystrix to shallow and deep reef habitats.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {303}, pmid = {22004364}, issn = {1471-2148}, mesh = {Adaptation, Biological/*physiology ; Analysis of Variance ; Animals ; Anthozoa/*genetics/microbiology/physiology ; Australia ; Base Sequence ; Chromatography, High Pressure Liquid ; Coral Reefs ; DNA, Mitochondrial/genetics ; DNA, Ribosomal Spacer/genetics ; Demography ; Dinoflagellida/*genetics ; *Ecosystem ; Haplotypes/genetics ; Molecular Sequence Data ; Oxygen Consumption/physiology ; Pacific Ocean ; *Selection, Genetic ; Sequence Analysis, DNA ; Survival Analysis ; }, abstract = {BACKGROUND: Divergent natural selection across environmental gradients has been acknowledged as a major driver of population and species divergence, however its role in the diversification of scleractinian corals remains poorly understood. Recently, it was demonstrated that the brooding coral Seriatopora hystrix and its algal endosymbionts (Symbiodinium) are genetically partitioned across reef environments (0-30 m) on the far northern Great Barrier Reef. Here, we explore the potential mechanisms underlying this differentiation and assess the stability of host-symbiont associations through a reciprocal transplantation experiment across habitats ('Back Reef', 'Upper Slope' and 'Deep Slope'), in combination with molecular (mtDNA and ITS2-DGGE) and photo-physiological analyses (respirometry and HPLC).<br><br>RESULTS: The highest survival rates were observed for native transplants (measured 14 months after transplantation), indicating differential selective pressures between habitats. Host-symbiont assemblages remained stable during the experimental duration, demonstrating that the ability to "shuffle" or "switch" symbionts is restricted in S. hystrix. Photo-physiological differences were observed between transplants originating from the shallow and deep habitats, with indirect evidence of an increased heterotrophic capacity in native deep-water transplants (from the 'Deep Slope' habitat). Similar photo-acclimatisation potential was observed between transplants originating from the two shallow habitats ('Back Reef' and 'Upper Slope'), highlighting that their genetic segregation over depth may be due to other, non-photo-physiological traits under selection.<br><br>CONCLUSIONS: This study confirms that the observed habitat partitioning of S. hystrix (and associated Symbiodinium) is reflective of adaptive divergence along a depth gradient. Gene flow appears to be reduced due to divergent selection, highlighting the potential role of ecological mechanisms, in addition to physical dispersal barriers, in the diversification of scleractinian corals and their associated Symbiodinium.}, }
@article {pmid22000100, year = {2011}, author = {Pusnik, M and Schmidt, O and Perry, AJ and Oeljeklaus, S and Niemann, M and Warscheid, B and Lithgow, T and Meisinger, C and Schneider, A}, title = {Mitochondrial preprotein translocase of trypanosomatids has a bacterial origin.}, journal = {Current biology : CB}, volume = {21}, number = {20}, pages = {1738-1743}, doi = {10.1016/j.cub.2011.08.060}, pmid = {22000100}, issn = {1879-0445}, mesh = {Bacterial Outer Membrane Proteins ; Bacterial Proteins/genetics/metabolism ; Escherichia coli Proteins ; Eukaryotic Cells/metabolism ; Evolution, Molecular ; Methotrexate/pharmacology ; Mitochondrial Membrane Transport Proteins/chemistry/genetics/*metabolism ; Mitochondrial Membranes/*metabolism ; Protein Conformation ; Protein Transport ; Recombinant Fusion Proteins/genetics/metabolism ; Saccharomyces cerevisiae Proteins/metabolism ; Tetrahydrofolate Dehydrogenase/genetics/metabolism ; Trypanosoma brucei brucei/drug effects/genetics/*metabolism ; Voltage-Dependent Anion Channels/genetics/metabolism ; }, abstract = {Mitochondria are found in all eukaryotic cells and derive from a bacterial endosymbiont [1, 2]. The evolution of a protein import system was a prerequisite for the conversion of the endosymbiont into a true organelle. Tom40, the essential component of the protein translocase of the outer membrane, is conserved in mitochondria of almost all eukaryotes but lacks bacterial orthologs [3-6]. It serves as the gateway through which all mitochondrial proteins are imported. The parasitic protozoa Trypanosoma brucei and its relatives do not have a Tom40-like protein, which raises the question of how proteins are imported by their mitochondria [7, 8]. Using a combination of bioinformatics and in vivo and in vitro studies, we have discovered that T. brucei likely employs a different import channel, termed ATOM (archaic translocase of the outer mitochondrial membrane). ATOM mediates the import of nuclear-encoded proteins into mitochondria and is essential for viability of trypanosomes. It is not related to Tom40 but is instead an ortholog of a subgroup of the Omp85 protein superfamily that is involved in membrane translocation and insertion of bacterial outer membrane proteins [9]. This suggests that the protein import channel in trypanosomes is a relic of an archaic protein transport system that was operational in the ancestor of all eukaryotes.}, }
@article {pmid21959316, year = {2011}, author = {Unckless, RL}, title = {The potential role of the X chromosome in the emergence of male-killing from mutualistic endosymbionts.}, journal = {Journal of theoretical biology}, volume = {291}, number = {}, pages = {99-104}, doi = {10.1016/j.jtbi.2011.09.007}, pmid = {21959316}, issn = {1095-8541}, mesh = {Animals ; Arthropods/genetics/*parasitology ; Female ; Host-Parasite Interactions ; Male ; *Models, Genetic ; Repetitive Sequences, Nucleic Acid ; Symbiosis/*genetics ; X Chromosome/*genetics ; }, abstract = {Endosymbionts infect most arthropods and cause a wide variety of phenotypes in their hosts, ranging from obligate mutualists to reproductive parasites. One of the most dramatic forms of reproductive parasitism is male-killing which involves the endosymbiont killing all of the sons of infected females. A phenotype with such a dramatic effect on host fitness is expected to provide strong selection for suppressors of male-killing, yet in many well-studied male-killer/arthropod systems, no suppressors have been found. Plausible explanations for a lack of resistance exist and include cryptic cytoplasmic incompatibility (males that survive male-killing are therefore infected and matings with uninfected females are incompatible) and deleterious pleiotropic effects of altering early embryonic development--the precise time when male-killing often occurs. Here I describe another possible scenario that sidesteps the problem: male killing may arise through an epistatic interaction between an endosymbiont and a paternally acting locus on the X chromosome. Since paternal X chromosomes never find themselves in sons, they never suffer from male-killing and instead enjoy any benefits (decreased sibling competition, inbreeding avoidance) caused by killing males. This scenario allows for the possibility that male-killing arose recently, even if there is no evidence for evolution in the endosymbiont genotype.}, }
@article {pmid21948522, year = {2012}, author = {Hansen, AK and Vorburger, C and Moran, NA}, title = {Genomic basis of endosymbiont-conferred protection against an insect parasitoid.}, journal = {Genome research}, volume = {22}, number = {1}, pages = {106-114}, pmid = {21948522}, issn = {1549-5469}, mesh = {Animals ; Aphids/genetics/*microbiology ; Bacterial Proteins/genetics/metabolism ; Bacterial Secretion Systems/physiology ; Biological Transport, Active/physiology ; Enterobacteriaceae/*physiology ; Genome, Bacterial/*physiology ; Host-Pathogen Interactions/*physiology ; O Antigens/genetics/metabolism ; Symbiosis/*physiology ; Virulence Factors/genetics/metabolism ; }, abstract = {Bacterial endosymbionts exert a variety of beneficial effects on insect hosts. In pea aphids (Acyrthosiphon pisum), several inherited endosymbiont species protect their hosts against parasitoid wasps, which are major natural enemies. However, strains of these symbiont species vary in their ability to confer protection against parasitoids, with some conferring almost complete protection and others conferring almost none. In this study, two strains of the endosymbiont Regiella insecticola (R. insecticola 5.15 and R. insecticola LSR1) were found to differ in ability to protect pea aphids attacked by the parasitoid Aphidius ervi. Parasitism trials reveal that R. insecticola 5.15, but not R. insecticola LSR1, significantly reduced parasitoid success and increased aphid survivorship. To address the potential genetic basis of protection conferred by R. insecticola 5.15 we sequenced the genome of this symbiont strain, and then compared its gene repertoire with that of the already sequenced nonprotective strain R. insecticola LSR1. We identified striking differences in gene sets related to eukaryote pathogenicity. The protective strain R. insecticola 5.15 encoded five categories of pathogenicity factors that were missing or inactivated in R. insecticola LSR1. These included genes encoding the O-antigen biosynthetic pathway, an intact Type 1 Secretion System and its secreted RTX toxins, an intact SPI-1 Type 3 Secretion System and its effectors, hemin transport, and the two-component system PhoPQ. These five pathogenicity factors and translocation systems are hypothesized to collectively play key roles in the endosymbiont's virulence against parasitoids, resulting in aphid protection. Mechanisms through which these factors may target parasitoids are discussed.}, }
@article {pmid21946455, year = {2012}, author = {Wu, K and Hoy, MA}, title = {Extended starvation reduced and eliminated Wolbachia, but not Cardinium, from Metaseiulus occidentalis females (Acari: Phytoseiidae): a need to reassess Wolbachia's status in this predatory mite?.}, journal = {Journal of invertebrate pathology}, volume = {109}, number = {1}, pages = {20-26}, doi = {10.1016/j.jip.2011.09.005}, pmid = {21946455}, issn = {1096-0805}, mesh = {Animals ; Bacterial Load ; Bacteroidetes/*physiology ; DNA, Bacterial/isolation &amp; purification ; Female ; *Host-Pathogen Interactions ; Mites/*microbiology/physiology ; Ovum/microbiology ; Pest Control, Biological ; Polymerase Chain Reaction/methods ; Starvation/*physiopathology ; Symbiosis/physiology ; Wolbachia/*physiology ; }, abstract = {The presence of Wolbachia and Cardinium bacteria has been documented in many arthropod species, including the predatory mite Metaseiulus (=Typhlodromus or Galendomus) occidentalis (Nesbitt) (Acari: Phytoseiidae). We show that Tetranychus urticae, the prey of Metaseiulus occidentalis, contains Wolbachia and no detectable Cardinium using quantitative PCR (qPCR). Starvation for 72 h at 22°C eliminated most, if not all, Wolbachia in M. occidentalis adult females from 7 laboratory colonies. Refeeding of M. occidentalis with T. urticae after starvation for 72 h restored the amounts of Wolbachia in M. occidentalis to those of prestarvation levels, suggesting that Wolbachia detected in M. occidentalis starved for shorter periods of time in current, and some previous, studies likely came from T. urticae. Furthermore, eggs from all M. occidentalis colonies examined were free of Wolbachia if they were surface-decontaminated with 0.3% sodium hypochlorite before DNA extraction. Cardinium was present in 6 of 14 laboratory colonies of M. occidentalis. Starvation for 3, 24, 48, and 72 h had no effect on the amounts of Cardinium in adult females from the Cardinium-positive colonies. Eggs from these colonies were positive for Cardinium but contained less than 1% of the titers found in adult females. The data suggest that Cardinium, but not Wolbachia, is an endosymbiont in certain populations of M. occidentalis. In light of our current findings, we recommend specific practices for the identification of potential symbionts in predatory arthropod species using the PCR.}, }
@article {pmid21945051, year = {2012}, author = {Müller, MJ and von Mühlen, C and Valiati, VH and da Silva Valente, VL}, title = {Wolbachia pipientis is associated with different mitochondrial haplotypes in natural populations of Drosophila willistoni.}, journal = {Journal of invertebrate pathology}, volume = {109}, number = {1}, pages = {152-155}, doi = {10.1016/j.jip.2011.08.011}, pmid = {21945051}, issn = {1096-0805}, mesh = {Animals ; Brazil ; DNA, Mitochondrial/genetics ; Drosophila/genetics/*microbiology ; Evolution, Molecular ; Gene Transfer, Horizontal ; Genetic Variation ; Gram-Negative Bacterial Infections/microbiology/*veterinary ; Haplotypes ; Host-Pathogen Interactions ; Mitochondria/*genetics/microbiology ; Pest Control, Biological ; Symbiosis ; Wolbachia/*pathogenicity/physiology ; }, abstract = {The prevalence of the endosymbiont Wolbachia pipientis and its effects on mitochondrial genetic diversity were analyzed in natural populations of Drosophila willistoni, a neotropical species recently infected. Total infection rate was 55% and no evidence was found that the Wolbachia infection decreased the diversity of mtDNA. Wolbachia was seen to be associated with different mitochondria, suggesting multiple horizontal transmission events and/or transmission paternal leakage of mitochondrial and/or Wolbachia. These hypotheses are evaluated in the context of the present study and other research.}, }
@article {pmid21944995, year = {2011}, author = {Liu, C and Kelen, PV and Ghedin, E and Lustigman, S and Unnasch, TR}, title = {Analysis of transcriptional regulation of tetracycline responsive genes in Brugia malayi.}, journal = {Molecular and biochemical parasitology}, volume = {180}, number = {2}, pages = {106-111}, pmid = {21944995}, issn = {1872-9428}, support = {R01 AI072465/AI/NIAID NIH HHS/United States ; R01 AI072465-04/AI/NIAID NIH HHS/United States ; 1R01AI072465/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Brugia malayi/*genetics/metabolism ; *Gene Expression Regulation ; Helminth Proteins/*genetics/metabolism ; Molecular Sequence Data ; *Response Elements ; TATA Box ; Tetracycline/*metabolism ; *Transcription, Genetic ; }, abstract = {The Wolbachia endosymbiont of the human filarial parasites is necessary for parasite reproduction, making it an attractive chemotherapeutic target. Previous studies have demonstrated that mRNA levels of several nuclearly encoded genes are altered as a result of exposure to antibiotics that eliminate the endosymbiont, suggesting that they may be involved in maintaining the parasite-endosymbiont relationship. Here, we tested the hypothesis that the increase in mRNA levels of certain nuclearly encoded genes of Brugia malayi in response to tetracycline treatment involved specific regulatory elements present in the promoters of these genes. The promoters of three such genes (BmRPL13, BmRPS4 and BmHSP70) were tested for tetracycline responsiveness utilizing a homologous transient transcription system. Reporter gene expression driven by all three promoters was up-regulated in transfected embryos exposed to tetracycline. Substitution mutagenesis was employed to map the cis-acting elements responsible for this response in the BmHSP70 promoter. Tetracycline responsiveness was found to be distinct from the cis-acting elements involved in regulating the stress response from the BmHSP70 promoter; rather, tetracycline responsiveness was mediated by a TATAA-box like element. This study represents the first demonstration of small molecule-mediated gene regulation of a native B. malayi promoter.}, }
@article {pmid21943523, year = {2011}, author = {José de Souza, D and Devers, S and Lenoir, A}, title = {Blochmannia endosymbionts and their host, the ant Camponotus fellah: cuticular hydrocarbons and melanization.}, journal = {Comptes rendus biologies}, volume = {334}, number = {10}, pages = {737-741}, doi = {10.1016/j.crvi.2011.06.008}, pmid = {21943523}, issn = {1768-3238}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Ants/*metabolism/*physiology ; Enterobacteriaceae/*metabolism ; Hydrocarbons/chemistry/*metabolism ; Melanins/chemistry/*metabolism ; Symbiosis/*physiology ; }, abstract = {Carpenter ants (genus Camponotus) have mutualistic, endosymbiotic bacteria of the genus Blochmannia whose main contribution to their hosts is alimentary. It was also recently demonstrated that they play a role in improving immune function as well. In this study, we show that treatment with an antibiotic produces a physiological response inducing an increase in both the quantity of cuticular hydrocarbons and in the melanization of the cuticle probably due to a nutritive and immunological deficit. We suggest that this is because it enhances the protection the cuticle provides from desiccation and also from invasions by pathogens and parasites. Nevertheless, the cuticular hydrocarbon profile is not modified by the antibiotic treatment, which indicates that nestmate recognition is not modified.}, }
@article {pmid21940637, year = {2011}, author = {Cerveau, N and Leclercq, S and Leroy, E and Bouchon, D and Cordaux, R}, title = {Short- and long-term evolutionary dynamics of bacterial insertion sequences: insights from Wolbachia endosymbionts.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {1175-1186}, pmid = {21940637}, issn = {1759-6653}, mesh = {Base Sequence ; *DNA Transposable Elements ; *Evolution, Molecular ; *Genome, Bacterial ; Phylogeny ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Transposable elements (TE) are one of the major driving forces of genome evolution, raising the question of the long-term dynamics underlying their evolutionary success. Long-term TE evolution can readily be reconstructed in eukaryotes, thanks to many degraded copies constituting genomic fossil records of past TE proliferations. By contrast, bacterial genomes usually experience high sequence turnover and short TE retention times, thereby obscuring ancient TE evolutionary patterns. We found that Wolbachia bacterial genomes contain 52-171 insertion sequence (IS) TEs. IS account for 11% of Wolbachia wRi, which is one of the highest IS genomic coverage reported in prokaryotes to date. We show that many IS groups are currently expanding in various Wolbachia genomes and that IS horizontal transfers are frequent among strains, which can explain the apparent synchronicity of these IS proliferations. Remarkably, >70% of Wolbachia IS are nonfunctional. They constitute an unusual bacterial IS genomic fossil record providing direct empirical evidence for a long-term IS evolutionary dynamics following successive periods of intense transpositional activity. Our results show that comprehensive IS annotations have the potential to provide new insights into prokaryote TE evolution and, more generally, prokaryote genome evolution. Indeed, the identification of an important IS genomic fossil record in Wolbachia demonstrates that IS elements are not always of recent origin, contrary to the conventional view of TE evolution in prokaryote genomes. Our results also raise the question whether the abundance of IS fossils is specific to Wolbachia or it may be a general, albeit overlooked, feature of prokaryote genomes.}, }
@article {pmid21938025, year = {2012}, author = {Hosokawa, T and Nikoh, N and Koga, R and Satô, M and Tanahashi, M and Meng, XY and Fukatsu, T}, title = {Reductive genome evolution, host-symbiont co-speciation and uterine transmission of endosymbiotic bacteria in bat flies.}, journal = {The ISME journal}, volume = {6}, number = {3}, pages = {577-587}, pmid = {21938025}, issn = {1751-7370}, mesh = {Animals ; Chiroptera/parasitology ; DNA, Bacterial/genetics ; Diptera/genetics/*microbiology ; Evolution, Molecular ; Female ; Gammaproteobacteria/*classification/genetics/physiology ; *Genetic Speciation ; Genitalia, Female/*microbiology ; Genome, Bacterial ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Bat flies of the family Nycteribiidae are known for their extreme morphological and physiological traits specialized for ectoparasitic blood-feeding lifestyle on bats, including lack of wings, reduced head and eyes, adenotrophic viviparity with a highly developed uterus and milk glands, as well as association with endosymbiotic bacteria. We investigated Japanese nycteribiid bat flies representing 4 genera, 8 species and 27 populations for their bacterial endosymbionts. From all the nycteribiid species examined, a distinct clade of gammaproteobacteria was consistently detected, which was allied to endosymbionts of other insects such as Riesia spp. of primate lice and Arsenophonus spp. of diverse insects. In adult insects, the endosymbiont was localized in specific bacteriocytes in the abdomen, suggesting an intimate host-symbiont association. In adult females, the endosymbiont was also found in the cavity of milk gland tubules, which suggests uterine vertical transmission of the endosymbiont to larvae through milk gland secretion. In adult females of Penicillidia jenynsii, we discovered a previously unknown type of symbiotic organ in the Nycteribiidae: a pair of large bacteriomes located inside the swellings on the fifth abdominal ventral plate. The endosymbiont genes consistently exhibited adenine/thymine biased nucleotide compositions and accelerated rates of molecular evolution. The endosymbiont genome was estimated to be highly reduced, ~0.76 Mb in size. The endosymbiont phylogeny perfectly mirrored the host insect phylogeny, indicating strict vertical transmission and host-symbiont co-speciation in the evolutionary course of the Nycteribiidae. The designation 'Candidatus Aschnera chinzeii' is proposed for the endosymbiont clade.}, }
@article {pmid21935411, year = {2011}, author = {Brindefalk, B and Ettema, TJ and Viklund, J and Thollesson, M and Andersson, SG}, title = {A phylometagenomic exploration of oceanic alphaproteobacteria reveals mitochondrial relatives unrelated to the SAR11 clade.}, journal = {PloS one}, volume = {6}, number = {9}, pages = {e24457}, pmid = {21935411}, issn = {1932-6203}, mesh = {Alphaproteobacteria/classification/*genetics ; Bacterial Proteins/*genetics ; Genome, Bacterial/genetics ; *Metagenomics ; *Phylogeny ; }, abstract = {BACKGROUND: According to the endosymbiont hypothesis, the mitochondrial system for aerobic respiration was derived from an ancestral Alphaproteobacterium. Phylogenetic studies indicate that the mitochondrial ancestor is most closely related to the Rickettsiales. Recently, it was suggested that Candidatus Pelagibacter ubique, a member of the SAR11 clade that is highly abundant in the oceans, is a sister taxon to the mitochondrial-Rickettsiales clade. The availability of ocean metagenome data substantially increases the sampling of Alphaproteobacteria inhabiting the oxygen-containing waters of the oceans that likely resemble the originating environment of mitochondria.<br><br>We present a phylogenetic study of the origin of mitochondria that incorporates metagenome data from the Global Ocean Sampling (GOS) expedition. We identify mitochondrially related sequences in the GOS dataset that represent a rare group of Alphaproteobacteria, designated OMAC (Oceanic Mitochondria Affiliated Clade) as the closest free-living relatives to mitochondria in the oceans. In addition, our analyses reject the hypothesis that the mitochondrial system for aerobic respiration is affiliated with that of the SAR11 clade.<br><br>CONCLUSIONS/SIGNIFICANCE: Our results allude to the existence of an alphaproteobacterial clade in the oxygen-rich surface waters of the oceans that represents the closest free-living relative to mitochondria identified thus far. In addition, our findings underscore the importance of expanding the taxonomic diversity in phylogenetic analyses beyond that represented by cultivated bacteria to study the origin of mitochondria.}, }
@article {pmid21933923, year = {2012}, author = {Bench, ME and White, MM}, title = {New species and first records of trichomycetes from immature aquatic insects in Idaho.}, journal = {Mycologia}, volume = {104}, number = {1}, pages = {295-312}, doi = {10.3852/11-203}, pmid = {21933923}, issn = {0027-5514}, mesh = {Animals ; Aquatic Organisms/microbiology ; Diptera/microbiology ; Fungi/*classification/isolation &amp; purification/ultrastructure ; Gastrointestinal Tract/microbiology ; Idaho ; Insecta/*microbiology ; Larva/microbiology ; Symbiosis ; }, abstract = {Trichomycetes, or gut fungi, are currently recognized as an ecological group of fungi and protists that inhabit the guts of immature insects or other stages and types of arthropods. The geographic distribution of these endosymbionts is worldwide. However trichomycete data from the Pacific Northwest are limited and this is the first account of gut fungi in Idaho. We report on the trichomycetes from a single site, Cottonwood Creek at Military Reserve Park, Boise, Idaho, where periodic surveys for more than a year resulted in the discovery of four newly named, three probably new but unnamed and 15 previously known species. Among the Harpellales three new species, Capniomyces sasquatchoides, Harpella torus and Lancisporomyces lampetriformis, are described, with two possibly new species of Smittium detailed but unnamed at this time pending further collections. A Genistelloides cf. hibernus also is included as a possible new species. One new species of Amoebidiales, Paramoebidium hamatum, is described as well. Hosts in which the gut fungi were recovered include larvae or nymphs of Diptera (Chironomidae and Simuliidae), Ephemeroptera (Baetidae) and Plecoptera (Capniidae and Taeniopterygidae). We hope to demonstrate that future surveys or bioprospecting investigations into the biodiversity of these early-diverging fungi in this region and worldwide remain promising.}, }
@article {pmid21923904, year = {2011}, author = {Stiller, JW}, title = {Experimental design and statistical rigor in phylogenomics of horizontal and endosymbiotic gene transfer.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {259}, pmid = {21923904}, issn = {1471-2148}, mesh = {Computational Biology/*methods ; *Evolution, Molecular ; Gene Transfer, Horizontal/*genetics ; Genome/*genetics ; Genomics/methods ; *Models, Genetic ; *Phylogeny ; Symbiosis/*genetics ; }, abstract = {A growing number of phylogenomic investigations from diverse eukaryotes are examining conflicts among gene trees as evidence of horizontal gene transfer. If multiple foreign genes from the same eukaryotic lineage are found in a given genome, it is increasingly interpreted as concerted gene transfers during a cryptic endosymbiosis in the organism's evolutionary past, also known as "endosymbiotic gene transfer" or EGT. A number of provocative hypotheses of lost or serially replaced endosymbionts have been advanced; to date, however, these inferences largely have been post-hoc interpretations of genomic-wide conflicts among gene trees. With data sets as large and complex as eukaryotic genome sequences, it is critical to examine alternative explanations for intra-genome phylogenetic conflicts, particularly how much conflicting signal is expected from directional biases and statistical noise. The availability of genome-level data both permits and necessitates phylogenomics that test explicit, a priori predictions of horizontal gene transfer, using rigorous statistical methods and clearly defined experimental controls.}, }
@article {pmid21923674, year = {2012}, author = {Henri, H and Mouton, L}, title = {High-resolution melting technology: a new tool for studying the Wolbachia endosymbiont diversity in the field.}, journal = {Molecular ecology resources}, volume = {12}, number = {1}, pages = {75-81}, doi = {10.1111/j.1755-0998.2011.03064.x}, pmid = {21923674}, issn = {1755-0998}, mesh = {Animals ; Arthropods/*microbiology/physiology ; *Biodiversity ; *Genetic Techniques ; Phylogeny ; *Symbiosis ; Transition Temperature ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Stable infections by maternally transmitted symbionts are frequently found in field populations, especially in arthropods. Many questions remain regarding their contribution to host biology and ecology, and especially on environmental adaptation of their host. Wolbachia is one of the most common endosymbiont of invertebrates. This cytoplasmically inherited endocellular bacterium induces number of reproductive alterations in its arthropod hosts and various fitness effects that allow it to spread in host populations. To better understand the influence of Wolbachia on host phenotypes and consequences of the manipulation of reproduction on the host genetic differentiation, it is crucial to be able to discriminate Wolbachia strains and determine their prevalence, which requires exhaustive screening. In the present report, we proposed the use of a new tool for the population studies, based on the high resolution melting (HRM) analysis, less expensive and faster than the 'classical' methods for large-scale studies. We investigated the effectiveness of HRM to explore and characterize the diversity of Wolbachia strains. Results obtained showed that HRM is a powerful tool to identify strains and detect polymorphism in singly infected hosts. When individuals harboured a mixture of Wolbachia strains (multiple infections), there is a risk of underestimation of the diversity if the proportions of the strains are highly different. However, the same limitations exist for the other techniques commonly used. Overall, this study demonstrated that HRM analysis is a rapid and reliable technique useful for studying, without a priori, Wolbachia strains diversity in field populations.}, }
@article {pmid21923264, year = {2011}, author = {Tveten, AK and Sjåstad, KK}, title = {Identification of bacteria infecting Ixodes ricinus ticks by 16S rDNA amplification and denaturing gradient gel electrophoresis.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {11}, number = {10}, pages = {1329-1334}, doi = {10.1089/vbz.2011.0657}, pmid = {21923264}, issn = {1557-7759}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Infections/microbiology/transmission/veterinary ; Cat Diseases/microbiology/parasitology/transmission ; Cats ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Denaturing Gradient Gel Electrophoresis ; Dog Diseases/microbiology/parasitology/transmission ; Dogs ; Humans ; Ixodes/*microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; Seasons ; Sequence Analysis, DNA ; Tick Infestations/parasitology/veterinary ; Zoonoses/transmission ; }, abstract = {Ticks harbor a complex microbial population, which they acquire while feeding on a variety of mammalians and birds. Zoonotic diseases transferred by ticks are an increasing problem and have become a burden to the community. 16S rDNA amplification and denaturing gradient gel electrophoresis (DGGE) enables detection of the broad spectrum of bacteria that settles in the ticks. Profiling the complete microbial population in ticks may provide a better understanding of the ticks' potential to harbor and disperse pathogens. Separation of pathogenic species by DGGE is based on variation in %GC content within the 16S rDNA genetic region. Sequencing of these fragments allows identification of bacterial species. Present study identified some well-known tick-infecting bacteria, such as members of genus Borrelia, Rickettsiales, and Pseudomonas, but also less described tick-infecting bacteria such as Rhodococcus erythropolis, Spiroplasma spp., and an endosymbiont of the microarthropod Folsomia candida. This is the first report of Segniliparus rugosus-infected Ixodes ricinus ticks. Also, it is the first report of several of these pathogens in the Norwegian tick population.}, }
@article {pmid21922235, year = {2012}, author = {McHaffie, J}, title = {Dirofilaria immitis and Wolbachia pipientis: a thorough investigation of the symbiosis responsible for canine heartworm disease.}, journal = {Parasitology research}, volume = {110}, number = {2}, pages = {499-502}, pmid = {21922235}, issn = {1432-1955}, mesh = {Animals ; Anti-Bacterial Agents/therapeutic use ; Dirofilaria immitis/*microbiology/*pathogenicity/physiology ; Dirofilariasis/drug therapy/*parasitology ; Dog Diseases/drug therapy/*parasitology ; Dogs ; Doxycycline/therapeutic use ; *Symbiosis ; Treatment Outcome ; United States ; Wolbachia/*physiology ; }, abstract = {Canine heartworm disease wreaks havoc inside canines all throughout the modern world, including the USA. Any region where mosquitoes thrive will provide efficient dog-to-dog transportation for the microfilaria of the infectious nematode Dirofilaria immitis. Veterinary scientists have recently discovered both phylogenetic and biochemical evidence for the obligate symbiosis of D. immitis and the bacteria Wolbachia pipientis. As a result, veterinarians have initiated testing of antibiotic therapies either instead of, or together with, the currently utilized antiparasitic treatments for canine heartworm. The toxicity of melarsomine adulticidal therapies has prompted an abundance of new research involving doxycycline and other antibiotics, which will be addressed in this review. As our knowledge of the Wolbachia endosymbiont expands, so will our abilities to minimize toxicity and maximize efficiency of heartworm treatments.}, }
@article {pmid21917276, year = {2012}, author = {van Dam, JW and Negri, AP and Mueller, JF and Uthicke, S}, title = {Symbiont-specific responses in foraminifera to the herbicide diuron.}, journal = {Marine pollution bulletin}, volume = {65}, number = {4-9}, pages = {373-383}, doi = {10.1016/j.marpolbul.2011.08.008}, pmid = {21917276}, issn = {1879-3363}, mesh = {Animals ; Anthozoa/physiology ; Chlorophyta/drug effects/physiology ; Diatoms ; Dinoflagellida/drug effects/physiology ; Diuron/*toxicity ; Foraminifera/*drug effects/physiology ; Herbicides/*toxicity ; Photosynthesis ; Symbiosis ; Water Pollutants, Chemical/*toxicity ; }, abstract = {The effects of the photosystem II (PSII) herbicide diuron was assessed on thirteen tropical foraminifera hosting diatom, dinoflagellate, red or green algae endosymbionts. Inhibition of photosynthesis (reduced ΔF/F(m)(')) by diuron depended on both symbiont type and test ultrastructure, with greatest sensitivity observed for diatom- and chlorophyte-hosting species (24h IC(25) 2.5-4μg L(-1)). Inhibition kinetics was slow (24-48h until maximum inhibition) in comparison with corals, suggesting structural differences may influence herbicide uptake and transport. Although foraminifera were generally less sensitive to direct effects of diuron (inhibition ΔF/F(m)(')) than other marine phototrophs, damage to PSII (reduction F(v)/F(m)) occurred at concentrations lower than observed for other organisms (24h IC(25) 3-12μg L(-1)). Damage to PSII was highly light dependent and occurred at very low light intensities indicating limited photoprotective capacity. The high diversity, widespread occurrence and relative sensitivity make foraminifera good bioindicator organisms to evaluate phytotoxic stress on coral reefs.}, }
@article {pmid21915326, year = {2011}, author = {Lemaire, B and Vandamme, P and Merckx, V and Smets, E and Dessein, S}, title = {Bacterial leaf symbiosis in angiosperms: host specificity without co-speciation.}, journal = {PloS one}, volume = {6}, number = {9}, pages = {e24430}, pmid = {21915326}, issn = {1932-6203}, mesh = {Bacteria/*classification/*genetics/growth &amp; development ; Burkholderia/classification/genetics/growth &amp; development ; Host Specificity/genetics/*physiology ; Magnoliopsida/*microbiology ; Phylogeny ; Symbiosis/genetics/*physiology ; }, abstract = {Bacterial leaf symbiosis is a unique and intimate interaction between bacteria and flowering plants, in which endosymbionts are organized in specialized leaf structures. Previously, bacterial leaf symbiosis has been described as a cyclic and obligate interaction in which the endosymbionts are vertically transmitted between plant generations and lack autonomous growth. Theoretically this allows for co-speciation between leaf nodulated plants and their endosymbionts. We sequenced the nodulated Burkholderia endosymbionts of 54 plant species from known leaf nodulated angiosperm genera, i.e. Ardisia, Pavetta, Psychotria and Sericanthe. Phylogenetic reconstruction of bacterial leaf symbionts and closely related free-living bacteria indicates the occurrence of multiple horizontal transfers of bacteria from the environment to leaf nodulated plant species. This rejects the hypothesis of a long co-speciation process between the bacterial endosymbionts and their host plants. Our results indicate a recent evolutionary process towards a stable and host specific interaction confirming the proposed maternal transmission mode of the endosymbionts through the seeds. Divergence estimates provide evidence for a relatively recent origin of bacterial leaf symbiosis, dating back to the Miocene (5-23 Mya). This geological epoch was characterized by cool and arid conditions, which may have triggered the origin of bacterial leaf symbiosis.}, }
@article {pmid21914892, year = {2011}, author = {López-Madrigal, S and Latorre, A and Porcar, M and Moya, A and Gil, R}, title = {Complete genome sequence of "Candidatus Tremblaya princeps" strain PCVAL, an intriguing translational machine below the living-cell status.}, journal = {Journal of bacteriology}, volume = {193}, number = {19}, pages = {5587-5588}, pmid = {21914892}, issn = {1098-5530}, mesh = {Animals ; Genome, Bacterial/*genetics ; Helicobacter/*genetics ; Hemiptera/microbiology ; Molecular Sequence Data ; }, abstract = {The sequence of the genome of "Candidatus Tremblaya princeps" strain PCVAL, the primary endosymbiont of the citrus mealybug Planococcus citri, has been determined. "Ca. Tremblaya princeps" presents an unusual nested endosymbiosis and harbors a gammaproteobacterial symbiont within its cytoplasm in all analyzed mealybugs. The genome sequence reveals that "Ca. Tremblaya princeps" cannot be considered an independent organism but that the consortium with its gammaproteobacterial symbiotic associate represents a new composite living being.}, }
@article {pmid21903677, year = {2012}, author = {Allen, AE and Moustafa, A and Montsant, A and Eckert, A and Kroth, PG and Bowler, C}, title = {Evolution and functional diversification of fructose bisphosphate aldolase genes in photosynthetic marine diatoms.}, journal = {Molecular biology and evolution}, volume = {29}, number = {1}, pages = {367-379}, pmid = {21903677}, issn = {1537-1719}, mesh = {Carbon/metabolism ; Carbonic Anhydrases/genetics ; Diatoms/chemistry/enzymology/*genetics/metabolism ; *Evolution, Molecular ; Fructose-Bisphosphate Aldolase/*genetics ; Phylogeny ; Phytoplankton/chemistry/enzymology/*genetics/metabolism ; Plastids/chemistry/metabolism ; Recombinant Fusion Proteins ; }, abstract = {Diatoms and other chlorophyll-c containing, or chromalveolate, algae are among the most productive and diverse phytoplankton in the ocean. Evolutionarily, chlorophyll-c algae are linked through common, although not necessarily monophyletic, acquisition of plastid endosymbionts of red as well as most likely green algal origin. There is also strong evidence for a relatively high level of lineage-specific bacterial gene acquisition within chromalveolates. Therefore, analyses of gene content and derivation in chromalveolate taxa have indicated particularly diverse origins of their overall gene repertoire. As a single group of functionally related enzymes spanning two distinct gene families, fructose 1,6-bisphosphate aldolases (FBAs) illustrate the influence on core biochemical pathways of specific evolutionary associations among diatoms and other chromalveolates with various plastid-bearing and bacterial endosymbionts. Protein localization and activity, gene expression, and phylogenetic analyses indicate that the pennate diatom Phaeodactylum tricornutum contains five FBA genes with very little overall functional overlap. Three P. tricornutum FBAs, one class I and two class II, are plastid localized, and each appears to have a distinct evolutionary origin as well as function. Class I plastid FBA appears to have been acquired by chromalveolates from a red algal endosymbiont, whereas one copy of class II plastid FBA is likely to have originated from an ancient green algal endosymbiont. The other copy appears to be the result of a chromalveolate-specific gene duplication. Plastid FBA I and chromalveolate-specific class II plastid FBA are localized in the pyrenoid region of the chloroplast where they are associated with β-carbonic anhydrase, which is known to play a significant role in regulation of the diatom carbon concentrating mechanism. The two pyrenoid-associated FBAs are distinguished by contrasting gene expression profiles under nutrient limiting compared with optimal CO2 fixation conditions, suggestive of a distinct specialized function for each. Cytosolically localized FBAs in P. tricornutum likely play a role in glycolysis and cytoskeleton function and seem to have originated from the stramenopile host cell and from diatom-specific bacterial gene transfer, respectively.}, }
@article {pmid21899749, year = {2011}, author = {Yang, Y and Maruyama, S and Sekimoto, H and Sakayama, H and Nozaki, H}, title = {An extended phylogenetic analysis reveals ancient origin of "non-green" phosphoribulokinase genes from two lineages of "green" secondary photosynthetic eukaryotes: Euglenophyta and Chlorarachniophyta.}, journal = {BMC research notes}, volume = {4}, number = {}, pages = {330}, pmid = {21899749}, issn = {1756-0500}, abstract = {BACKGROUND: Euglenophyta and Chlorarachniophyta are groups of photosynthetic eukaryotes harboring secondary plastids of distinct green algal origins. Although previous phylogenetic analyses of genes encoding Calvin cycle enzymes demonstrated the presence of genes apparently not derived from green algal endosymbionts in the nuclear genomes of Euglena gracilis (Euglenophyta) and Bigelowiella natans (Chlorarachniophyta), the origins of these "non-green" genes in "green" secondary phototrophs were unclear due to the limited taxon sampling.<br><br>RESULTS: Here, we sequenced five new phosphoribulokinase (PRK) genes (from one euglenophyte, two chlorarachniophytes, and two glaucophytes) and performed an extended phylogenetic analysis of the genes based on a phylum-wide taxon sampling from various photosynthetic eukaryotes. Our phylogenetic analyses demonstrated that the PRK sequences form two genera of Euglenophyta formed a robust monophyletic group within a large clade including stramenopiles, haptophytes and a cryptophyte, and three genera of Chlorarachniophyta were placed within the red algal clade. These "non-green" affiliations were supported by the taxon-specific insertion/deletion sequences in the PRK alignment, especially between euglenophytes and stramenopiles. In addition, phylogenetic analysis of another Calvin cycle enzyme, plastid-targeted sedoheptulose-bisphosphatase (SBP), showed that the SBP sequences from two genera of Chlorarachniophyta were positioned within a red algal clade.<br><br>CONCLUSIONS: Our results suggest that PRK genes may have been transferred from a "stramenopile" ancestor to Euglenophyta and from a "red algal" ancestor to Chlorarachniophyta before radiation of extant taxa of these two "green" secondary phototrophs. The presence of two of key Calvin cycle enzymes, PRK and SBP, of red algal origins in Chlorarachniophyta indicate that the contribution of "non-green" algae to the plastid proteome in the "green" secondary phototrophs is more significant than ever thought. These "non-green" putative plastid-targeted enzymes from Chlorarachniophyta are likely to have originated from an ancestral red alga via horizontal gene transfer, or from a cryptic red algal endosymbiosis in the common ancestor of the extant chlorarachniophytes.}, }
@article {pmid21892672, year = {2012}, author = {Bressan, A and Terlizzi, F and Credi, R}, title = {Independent origins of vectored plant pathogenic bacteria from arthropod-associated Arsenophonus endosymbionts.}, journal = {Microbial ecology}, volume = {63}, number = {3}, pages = {628-638}, pmid = {21892672}, issn = {1432-184X}, mesh = {Animals ; Beta vulgaris/*microbiology ; Enterobacteriaceae/classification/genetics/*isolation &amp; purification/*physiology ; Female ; Fragaria/*microbiology ; Hemiptera/*microbiology/physiology ; Male ; Molecular Sequence Data ; Phylogeny ; Plant Diseases/*microbiology ; *Symbiosis ; }, abstract = {The genus Arsenophonus (Gammaproteobacteria) is comprised of intracellular symbiotic bacteria that are widespread across the arthropods. These bacteria can significantly influence the ecology and life history of their hosts. For instance, Arsenophonus nasoniae causes an excess of females in the progeny of parasitoid wasps by selectively killing the male embryos. Other Arsenophonus bacteria have been suspected to protect insect hosts from parasitoid wasps or to expand the host plant range of phytophagous sap-sucking insects. In addition, a few reports have also documented some Arsenophonus bacteria as plant pathogens. The adaptation to a plant pathogenic lifestyle seems to be promoted by the infection of sap-sucking insects in the family Cixiidae, which then transmit these bacteria to plants during the feeding process. In this study, we define the specific localization of an Arsenophonus bacterium pathogenic to sugar beet and strawberry plants within the plant hosts and the insect vector, Pentastiridius leporinus (Hemiptera: Cixiidae), using fluorescence in situ hybridization assays. Phylogenetic analysis on 16S rRNA and nucleotide coding sequences, using both maximum likelihood and Bayesian criteria, revealed that this bacterium is not a sister taxon to "Candidatus Phlomobacter fragariae," a previously characterized Arsenophonus bacterium pathogenic to strawberry plants in France and Japan. Ancestral state reconstruction analysis indicated that the adaptation to a plant pathogenic lifestyle likely evolved from an arthropod-associated lifestyle and showed that within the genus Arsenophonus, the plant pathogenic lifestyle arose independently at least twice. We also propose a novel Candidatus status, "Candidatus Arsenophonus phytopathogenicus" novel species, for the bacterium associated with sugar beet and strawberry diseases and transmitted by the planthopper P. leporinus.}, }
@article {pmid21890906, year = {2011}, author = {Iyer, LM and Zhang, D and Rogozin, IB and Aravind, L}, title = {Evolution of the deaminase fold and multiple origins of eukaryotic editing and mutagenic nucleic acid deaminases from bacterial toxin systems.}, journal = {Nucleic acids research}, volume = {39}, number = {22}, pages = {9473-9497}, pmid = {21890906}, issn = {1362-4962}, support = {//Intramural NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Aminohydrolases/*chemistry/*classification ; Bacterial Toxins/*chemistry/metabolism ; Catalytic Domain ; Eukaryota/enzymology ; *Evolution, Molecular ; Models, Molecular ; Molecular Sequence Data ; *Mutagenesis ; Nucleic Acids/metabolism ; Nucleotides/metabolism ; Phylogeny ; Protein Folding ; Protein Structure, Tertiary ; *RNA Editing ; Sequence Alignment ; }, abstract = {The deaminase-like fold includes, in addition to nucleic acid/nucleotide deaminases, several catalytic domains such as the JAB domain, and others involved in nucleotide and ADP-ribose metabolism. Using sensitive sequence and structural comparison methods, we develop a comprehensive natural classification of the deaminase-like fold and show that its ancestral version was likely to operate on nucleotides or nucleic acids. Consequently, we present evidence that a specific group of JAB domains are likely to possess a DNA repair function, distinct from the previously known deubiquitinating peptidase activity. We also identified numerous previously unknown clades of nucleic acid deaminases. Using inference based on contextual information, we suggest that most of these clades are toxin domains of two distinct classes of bacterial toxin systems, namely polymorphic toxins implicated in bacterial interstrain competition and those that target distantly related cells. Genome context information suggests that these toxins might be delivered via diverse secretory systems, such as Type V, Type VI, PVC and a novel PrsW-like intramembrane peptidase-dependent mechanism. We propose that certain deaminase toxins might be deployed by diverse extracellular and intracellular pathogens as also endosymbionts as effectors targeting nucleic acids of host cells. Our analysis suggests that these toxin deaminases have been acquired by eukaryotes on several independent occasions and recruited as organellar or nucleo-cytoplasmic RNA modifiers, operating on tRNAs, mRNAs and short non-coding RNAs, and also as mutators of hyper-variable genes, viruses and selfish elements. This scenario potentially explains the origin of mutagenic AID/APOBEC-like deaminases, including novel versions from Caenorhabditis, Nematostella and diverse algae and a large class of fast-evolving fungal deaminases. These observations greatly expand the distribution of possible unidentified mutagenic processes catalyzed by nucleic acid deaminases.}, }
@article {pmid21887359, year = {2011}, author = {Palmer, CV and Traylor-Knowles, NG and Willis, BL and Bythell, JC}, title = {Corals use similar immune cells and wound-healing processes as those of higher organisms.}, journal = {PloS one}, volume = {6}, number = {8}, pages = {e23992}, pmid = {21887359}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*immunology ; Cell Count ; Cell Movement ; Cell Proliferation ; Immune System/*cytology ; Melanins ; Wound Healing/*immunology ; }, abstract = {Sessile animals, like corals, frequently suffer physical injury from a variety of sources, thus wound-healing mechanisms that restore tissue integrity and prevent infection are vitally important for defence. Despite the ecological importance of reef-building corals, little is known about the cells and processes involved in wound healing in this group or in phylogenetically basal metazoans in general. A histological investigation into wound healing of the scleractinian coral Porites cylindrica at 0 h, 6 h, 24 h and 48 h after injury revealed differences in cellular components between injured and healthy tissues. Cell counts of the obligate endosymbiont, Symbiodinium, and melanin volume fraction analysis revealed rapid declines in both Symbiodinium abundance and tissue cross-sectional area occupied by melanin-containing granular cells after injury. Four phases of wound healing were identified, which are similar to phases described for both vertebrates and invertebrates. The four phases included (i) plug formation via the degranulation of melanin-containing granular cells; (ii) immune cell infiltration (inflammation); (iii) granular tissue formation (proliferation); and (iv) maturation. This study provides detailed documentation of the processes involved in scleractinian wound healing for the first time and further elucidates the roles of previously-described immune cells, such as fibroblasts. These results demonstrate the conservation of wound healing processes from anthozoans to humans.}, }
@article {pmid21876745, year = {2011}, author = {Hartung, JS and Shao, J and Kuykendall, LD}, title = {Comparison of the 'Ca. Liberibacter asiaticus' genome adapted for an intracellular lifestyle with other members of the Rhizobiales.}, journal = {PloS one}, volume = {6}, number = {8}, pages = {e23289}, pmid = {21876745}, issn = {1932-6203}, mesh = {Adaptation, Physiological/*genetics ; Amino Acids/metabolism ; Bacterial Proteins/genetics/metabolism ; Base Composition/genetics ; Codon/genetics ; DNA Polymerase III/metabolism ; DNA Repair/genetics ; DNA Replication/genetics ; Genome, Bacterial/*genetics ; Intracellular Space/*microbiology ; Isoelectric Point ; Purines/metabolism ; Pyrimidines/metabolism ; Rhizobiaceae/*genetics ; Sequence Homology, Amino Acid ; Sigma Factor/metabolism ; Synteny/genetics ; }, abstract = {An intracellular plant pathogen 'Candidatus Liberibacter asiaticus,' a member of the Rhizobiales, is related to Sinorhizobium meliloti, Bradyrhizobium japonicum, nitrogen fixing endosymbionts, Agrobacterium tumefaciens, a plant pathogen, and Bartonella henselae, an intracellular mammalian pathogen. Whole chromosome comparisons identified at least 50 clusters of conserved orthologous genes found on the chromosomes of all five metabolically diverse species. The intracellular pathogens 'Ca. Liberibacter asiaticus' and Bartonella henselae have genomes drastically reduced in gene content and size as well as a relatively low content of guanine and cytosine. Codon and amino acid preferences that emphasize low guanosine and cytosine usage are globally employed in these genomes, including within regions of microsynteny and within signature sequences of orthologous proteins. The length of orthologous proteins is generally conserved, but not their isoelectric points, consistent with extensive amino acid substitutions to accommodate selection for low GC content. The 'Ca. Liberibacter asiaticus' genome apparently has all of the genes required for DNA replication present in Sinorhizobium meliloti except it has only two, rather than three RNaseH genes. The gene set required for DNA repair has only one rather than ten DNA ligases found in Sinorhizobium meliloti, and the DNA PolI of 'Ca. Liberibacter asiaticus' lacks domains needed for excision repair. Thus the ability of 'Ca. Liberibacter asiaticus' to repair mutations in its genome may be impaired. Both 'Ca. Liberibacter asiaticus and Bartonella henselae lack enzymes needed for the metabolism of purines and pyrimidines, which must therefore be obtained from the host. The 'Ca. Liberibacter asiaticus' genome also has a greatly reduced set of sigma factors used to control transcription, and lacks sigma factors 24, 28 and 38. The 'Ca. Liberibacter asiaticus' genome has all of the hallmarks of a reduced genome of a pathogen adapted to an intracellular lifestyle.}, }
@article {pmid21870967, year = {2011}, author = {Cheng, RX and Meng, L and Mills, NJ and Li, B}, title = {Host preference between symbiotic and aposymbiotic Aphis fabae, by the aphid parasitoid, Lysiphlebus ambiguus.}, journal = {Journal of insect science (Online)}, volume = {11}, number = {}, pages = {81}, pmid = {21870967}, issn = {1536-2442}, mesh = {Animals ; Aphids/microbiology/*parasitology ; Choice Behavior ; Enterobacteriaceae/physiology ; Female ; *Host Specificity ; Larva/physiology ; Oviposition ; *Symbiosis ; Wasps/*physiology ; }, abstract = {Few empirical studies have directly explored the association between Buchnera aphidicola (Enterobacteriales: Enterobacteriaceae), the primary endosymbiont of aphids, and the life history strategies of aphid parasitoids. A series of paired-choice experiments were conducted to explore the preference of the parasitoid Lysiphlebus ambiguus Halliday (Hymenoptera: Aphididae) for symbiotic and aposymbiotic Aphis fabae Scopoli (Hemiptera: Aphididae) and the suitability of these hosts for parasitoid development. When given a choice between symbiotic and aposymbiotic aphids of the same instar, the parasitoid significantly preferred symbiotic over aposymbiotic aphids only during the later instars (L(4) and adult). The suitability of aposymbiotic aphids for parasitoid development was equal to that of symbiotic aphids in terms of survivorship and sex ratio, but was significantly lower than that of symbiotic aphids for L(4) and adult instars in development rate and/or female adult size. When given a choice between similar-sized symbiotic L(2) and aposymbiotic L(4) aphids, the parasitoid preferred the former. No significant differences in preference or host suitability were demonstrated when the parasitoid was given a choice between different instars of aposymbiotic aphids. While parasitoid lifetime fecundity increased with aphid instar at the time of oviposition, there was no significant influence of previous development from symbiotic versus aposymbiotic aphids. These results suggest that while L. ambiguus can discriminate between symbiotic and aposymbiotic A. fabae during later instars and when the aphids are of a similar size, the primary endosymbiont is not needed for successful parasitoid development; and its absence only compromises parasitoid growth reared from later instar aposymbiotic host.}, }
@article {pmid21868045, year = {2012}, author = {Cooper, TF and Fabricius, KE}, title = {Pigmentation of massive corals as a simple bioindicator for marine water quality.}, journal = {Marine pollution bulletin}, volume = {65}, number = {4-9}, pages = {333-341}, doi = {10.1016/j.marpolbul.2011.07.019}, pmid = {21868045}, issn = {1879-3363}, mesh = {Acclimatization ; Animals ; Anthozoa/*physiology ; Australia ; Chlorophyll/analysis/metabolism ; Chlorophyll A ; Color ; Environmental Monitoring/*methods ; Photosynthesis ; *Pigmentation ; Seawater/chemistry ; }, abstract = {Photo-acclimatisation by the algal endosymbionts of scleractinian corals to changes in environmental conditions may influence their density and/or the concentration of photosynthetic pigments, and hence coral brightness, on short time-scales. To examine coral pigmentation as a bioindicator of water quality, the brightness of massive corals was quantified using colour charts, concentrations of the pigment chlorophyll a and reflectance spectrometry in the field and with manipulative experiments. Along a water quality gradient, massive Porites became progressively lighter as nutrients decreased and irradiance increased. A laboratory experiment showed that Porites nubbins darkened within 25 days following exposure to reduced water quality. The results of a transplantation experiment of Porites nubbins in a manipulation incorporating multiple depths and zones of water quality confirmed colony brightness as a simple tool to monitor changes in marine water quality, provided effects due to other influences on pigmentation, e.g. seawater temperatures, are taken into consideration.}, }
@article {pmid21858149, year = {2011}, author = {Friberg, U and Stewart, AD and Rice, WR}, title = {Empirical evidence for son-killing X chromosomes and the operation of SA-zygotic drive.}, journal = {PloS one}, volume = {6}, number = {8}, pages = {e23508}, pmid = {21858149}, issn = {1932-6203}, support = {R01 HD057974/HD/NICHD NIH HHS/United States ; 1R01HD057974-01/HD/NICHD NIH HHS/United States ; }, mesh = {Algorithms ; Animals ; Diploidy ; Female ; Gametogenesis/genetics ; Genes, Insect/genetics ; Haploidy ; Inheritance Patterns ; Male ; *Models, Genetic ; Selection, Genetic ; Sex Factors ; Sex Ratio ; X Chromosome/*genetics ; Y Chromosome/*genetics ; Zygote/*metabolism ; }, abstract = {BACKGROUND: Diploid organisms have two copies of all genes, but only one is carried by each haploid gamete and diploid offspring. This causes a fundamental genetic conflict over transmission rate between alternative alleles. Single genes, or gene clusters, only rarely code for the complex phenotypes needed to give them a transmission advantage (drive phenotype). However, all genes on a male's X and Y chromosomes co-segregate, allowing different sex-linked genes to code for different parts of the drive phenotype. Correspondingly, the well-characterized phenomenon of male gametic drive, occurring during haploid gametogenesis, is especially common on sex chromosomes. The new theory of sexually antagonistic zygotic drive of the sex chromosomes (SA-zygotic drive) extends the logic of gametic drive into the diploid phase of the lifecycle, whenever there is competition among siblings or harmful sib-sib mating. The X and Y are predicted to gain a transmission advantage by harming offspring of the sex that does not carry them.<br><br>RESULTS: Here we analyzed a mutant X-chromosome in Drosophila simulans that produced an excess of daughters when transmitted from males. We developed a series of tests to differentiate between gametic and SA-zygotic drive, and provide multiple lines of evidence that SA-zygotic drive is responsible for the sex ratio bias. Driving sires produce about 50% more surviving daughters than sons.<br><br>CONCLUSION: Sex-ratio distortion due to genetic conflict has evolved via gametic drive and maternally transmitted endosymbionts. Our data indicate that sex chromosomes can also drive by harming the non-carrier sex of offspring.}, }
@article {pmid21855000, year = {2011}, author = {Keeling, PJ}, title = {Endosymbiosis: bacteria sharing the load.}, journal = {Current biology : CB}, volume = {21}, number = {16}, pages = {R623-4}, doi = {10.1016/j.cub.2011.06.061}, pmid = {21855000}, issn = {1879-0445}, mesh = {Animals ; Betaproteobacteria/*metabolism ; Gammaproteobacteria/*metabolism/*pathogenicity ; Hemiptera/*metabolism/*microbiology ; *Metabolic Networks and Pathways ; *Symbiosis ; }, abstract = {A nested set of bacterial endosymbionts within mealybug cells collectively provides amino acids to their host, but their genomes show that some pathways are distributed between both endosymbionts, while other essential proteins are missing altogether. The possibility that additional functions are shared between partners warrants comparisons with organelles.}, }
@article {pmid21853145, year = {2011}, author = {Alves, JM and Voegtly, L and Matveyev, AV and Lara, AM and da Silva, FM and Serrano, MG and Buck, GA and Teixeira, MM and Camargo, EP}, title = {Identification and phylogenetic analysis of heme synthesis genes in trypanosomatids and their bacterial endosymbionts.}, journal = {PloS one}, volume = {6}, number = {8}, pages = {e23518}, pmid = {21853145}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*genetics ; Biosynthetic Pathways/genetics ; DNA, Kinetoplast/genetics ; Genes, Bacterial/*genetics ; Genes, Protozoan/*genetics ; Heme/*biosynthesis ; Likelihood Functions ; *Phylogeny ; Symbiosis/*genetics ; Trypanosomatina/*genetics/microbiology ; }, abstract = {It has been known for decades that some insect-infecting trypanosomatids can survive in culture without heme supplementation while others cannot, and that this capability is associated with the presence of a betaproteobacterial endosymbiont in the flagellate's cytoplasm. However, the specific mechanisms involved in this process remained obscure. In this work, we sequence and phylogenetically analyze the heme pathway genes from the symbionts and from their hosts, as well as from a number of heme synthesis-deficient Kinetoplastida. Our results show that the enzymes responsible for synthesis of heme are encoded on the symbiont genomes and produced in close cooperation with the flagellate host. Our evidence suggests that this synergistic relationship is the end result of a history of extensive gene loss and multiple lateral gene transfer events in different branches of the phylogeny of the Trypanosomatidae.}, }
@article {pmid21833539, year = {2012}, author = {Chochlakis, D and Ioannou, I and Sandalakis, V and Dimitriou, T and Kassinis, N and Papadopoulos, B and Tselentis, Y and Psaroulaki, A}, title = {Spotted fever group Rickettsiae in ticks in Cyprus.}, journal = {Microbial ecology}, volume = {63}, number = {2}, pages = {314-323}, pmid = {21833539}, issn = {1432-184X}, mesh = {Animals ; Antigens, Bacterial/genetics ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Canidae ; Citrate (si)-Synthase/genetics ; Cyprus ; Hares ; Ixodidae/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Rickettsia/*classification/genetics/*isolation &amp; purification ; Rickettsia Infections/epidemiology/microbiology/parasitology/veterinary ; Ruminants ; Seasons ; Sequence Analysis, DNA ; Species Specificity ; Tick-Borne Diseases/epidemiology/microbiology/parasitology/veterinary ; }, abstract = {In two surveys conducted from March 1999 to March 2001 and from January 2004 to December 2006, a total of 3,950 ticks (belonging to ten different species) were collected from seven domestic and wild animals (goat, sheep, cattle, dog, fox, hare, and mouflon) from different localities throughout Cyprus. In order to establish their infection rate with Spotted Fever Rickettsiae (SFG), ticks were pooled and tested by polymerase chain reaction targeting gltA and ompA genes, followed by sequencing analysis. When tick pools tested positive, individual ticks were then tested one by one, and of the 3,950 ticks screened, rickettsial DNA was identified in 315 ticks (infection rate, 8%). Five SFG Rickettsiae were identified: Rickettsia aeschlimannii in Hyalomma marginatum marginatum, Rickettsia massiliae in Rhipicephalus turanicus and Rhipicephalus sanguineus, Rickettsia sibirica mongolotimonae in Hyalomma anatolicum excavatum, and a Rickettsia endosymbiont of Haemaphysalis sulcata (later described as Rickettsia hoogstraalii) in Haemaphysalis punctata. Two additional genes, 17 kDa and ompB, were targeted to characterize a new genotype of "Candidatus Rickettsia barbariae" genotype in R. turanicus, designated here as "Candidatus Rickettsia barbariae" Cretocypriensis. These results confirm the presence of a spectrum of SFG Rickettsiae on the island. Further studies are necessary to gain better knowledge on the epidemiology of SFG Rickettsiae in Cyprus.}, }
@article {pmid21833037, year = {2012}, author = {Toenshoff, ER and Penz, T and Narzt, T and Collingro, A and Schmitz-Esser, S and Pfeiffer, S and Klepal, W and Wagner, M and Weinmaier, T and Rattei, T and Horn, M}, title = {Bacteriocyte-associated gammaproteobacterial symbionts of the Adelges nordmannianae/piceae complex (Hemiptera: Adelgidae).}, journal = {The ISME journal}, volume = {6}, number = {2}, pages = {384-396}, pmid = {21833037}, issn = {1751-7370}, support = {P 22533/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Gammaproteobacteria/*classification/genetics/*physiology/ultrastructure ; Hemiptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; *Symbiosis ; }, abstract = {Adelgids (Insecta: Hemiptera: Adelgidae) are known as severe pests of various conifers in North America, Canada, Europe and Asia. Here, we present the first molecular identification of bacteriocyte-associated symbionts in these plant sap-sucking insects. Three geographically distant populations of members of the Adelges nordmannianae/piceae complex, identified based on coI and ef1alpha gene sequences, were investigated. Electron and light microscopy revealed two morphologically different endosymbionts, coccoid or polymorphic, which are located in distinct bacteriocytes. Phylogenetic analyses of their 16S and 23S rRNA gene sequences assigned both symbionts to novel lineages within the Gammaproteobacteria sharing <92% 16S rRNA sequence similarity with each other and showing no close relationship with known symbionts of insects. Their identity and intracellular location were confirmed by fluorescence in situ hybridization, and the names 'Candidatus Steffania adelgidicola' and 'Candidatus Ecksteinia adelgidicola' are proposed for tentative classification. Both symbionts were present in all individuals of all investigated populations and in different adelgid life stages including eggs, suggesting vertical transmission from mother to offspring. An 85 kb genome fragment of 'Candidatus S. adelgidicola' was reconstructed based on a metagenomic library created from purified symbionts. Genomic features including the frequency of pseudogenes, the average length of intergenic regions and the presence of several genes which are absent in other long-term obligate symbionts, suggested that 'Candidatus S. adelgidicola' is an evolutionarily young bacteriocyte-associated symbiont, which has been acquired after diversification of adelgids from their aphid sister group.}, }
@article {pmid21831194, year = {2012}, author = {Müller, JP and Hauzy, C and Hulot, FD}, title = {Ingredients for protist coexistence: competition, endosymbiosis and a pinch of biochemical interactions.}, journal = {The Journal of animal ecology}, volume = {81}, number = {1}, pages = {222-232}, doi = {10.1111/j.1365-2656.2011.01894.x}, pmid = {21831194}, issn = {1365-2656}, mesh = {Bacteria/growth &amp; development ; Chlorella vulgaris/*physiology ; *Food Chain ; Paramecium/*microbiology/*physiology ; Population Density ; Species Specificity ; *Symbiosis ; Tetrahymena pyriformis/physiology ; Tetrahymenina/*physiology ; }, abstract = {1. The interaction between mutualism, facilitation or interference and exploitation competition is of major interest as it may govern species coexistence. However, the interplay of these mechanisms has received little attention. This issue dates back to Gause, who experimentally explored competition using protists as a model [Gause, G.F. (1935) Vérifications expérimentales de la théorie mathématique de la lutte pour la vie. Actualités Scientifiques et Industrielles, 277]. He showed the coexistence of Paramecium caudatum with a potentially allelopathic species, Paramecium bursaria. 2. Paramecium bursaria hosts the green algae Chlorella vulgaris. Therefore, P. bursaria may benefit from carbohydrates synthesised by the algae. Studying endosymbiosis with P. bursaria is possible as it can be freed of its endosymbiont. In addition, C. vulgaris is known to produce allelochemicals, and P. bursaria may benefit also from allelopathic compounds. 3. We designed an experiment to separate the effects of resource exploitation, endosymbiosis and allelopathy and to assess their relative importance for the coexistence of P. bursaria with a competitor that exploits the same resource, bacteria. The experiment was repeated with two competitors, Colpidium striatum or Tetrahymena pyriformis. 4. Results show that the presence of the endosymbiont enables the coexistence of competitors, while its loss leads to competitive exclusion. These results are in agreement with predictions based on resource equilibrium density of monocultures (R*) supporting the idea that P. bursaria's endosymbiont is a resource provider for its host. When P. bursaria and T. pyriformis coexist, the density of the latter shows large variation that match the effects of culture medium of P. bursaria. Our experiment suggests these effects are because of biochemicals produced in P. bursaria culture. 5. Our results expose the hidden diversity of mechanisms that underlie competitive interactions. They thus support Gauses's speculation (1935) that allelopathic effects might have been involved in his competition experiments. We discuss how a species engaged both in competition for a resource and in costly interference such as allelopathy may counterbalance these costs with a resource-provider endosymbiont.}, }
@article {pmid21827871, year = {2011}, author = {Shiny, C and Krushna, NS and Babu, S and Elango, S and Manokaran, G and Narayanan, RB}, title = {Recombinant Wolbachia heat shock protein 60 (HSP60) mediated immune responses in patients with lymphatic filariasis.}, journal = {Microbes and infection}, volume = {13}, number = {14-15}, pages = {1221-1231}, pmid = {21827871}, issn = {1769-714X}, support = {Z99 AI999999/ImNIH/Intramural NIH HHS/United States ; }, mesh = {Adolescent ; Adult ; Animals ; Bacterial Proteins/genetics/*immunology/pharmacology ; Brugia malayi/immunology/*microbiology ; CTLA-4 Antigen/immunology ; Cells, Cultured ; Chaperonin 60/genetics/*immunology/pharmacology ; Child ; Elephantiasis, Filarial/*immunology/parasitology ; Female ; Humans ; Immunomodulation/drug effects ; Interferon-gamma/biosynthesis/immunology ; Interleukin-10/biosynthesis/immunology ; Interleukin-2 Receptor alpha Subunit/immunology ; Lymphocyte Activation/drug effects ; Male ; Recombinant Proteins/genetics/*immunology/pharmacology ; Symbiosis ; T-Lymphocytes, Regulatory/drug effects/*immunology ; Transforming Growth Factor beta/biosynthesis/immunology ; Wolbachia/chemistry/physiology ; }, abstract = {Wolbachia, an endosymbiont present in filarial nematodes, have been implicated in a variety of roles, including the worm development and survival. Elucidation of the role of Wolbachia in filarial nematode biology and pathogenesis has become the focus of many studies and its contribution to parasite survival or immune response is still unclear. Recombinant Wolbachia HSP60 decreases T cell activation and lymphoproliferation in filarial infected people compared to endemic controls as observed by the assessment of T cell activation markers and cytokine responses in the peripheral blood mononuclear cells. Reduced T cell activation may be linked to T regulatory cell activity since it is associated with increased expression of CTLA4 and CD25 on CD4(+) T cells in filarial infected group upon stimulation with recombinant Wolbachia HSP60. In addition, elevated interleukin-10 and TGF-β cytokines corroborate the reduced CD4(+) T cell activation and interferon-γ observed upon recombinant Wolbachia HSP60 stimulation in filarial patients. Hence, these findings indicate that Wolbachia HSP60 may also contribute to the immune modulation seen in filarial patients.}, }
@article {pmid21826891, year = {2011}, author = {Xuan, YH and Cui, CQ and Zheng, SZ}, title = {[Sequence analysis of 16S rDNA gene of endosymbiont of Acanthamoeba sp. CB/S1 isolated from soil].}, journal = {Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology &amp; parasitic diseases}, volume = {29}, number = {2}, pages = {98-100}, pmid = {21826891}, issn = {1000-7423}, mesh = {Acanthamoeba/*microbiology ; Base Sequence ; DNA, Bacterial/*genetics ; DNA, Ribosomal/*genetics ; Phylogeny ; Sequence Analysis, DNA ; Soil Microbiology ; }, abstract = {The endosymbiont of Acanthamoeba sp. CB/SI was identified by orcein-carmine staining and 16S rDNA sequence analysis. The endosymbiont bacteria were rod-shaped and darkly stained, and irregularly localized within the cytoplasm. The length of the 16S rDNA was 1534 bp and its DNA sequence was closely related to those of Candidatus Amoebophilus asiaticus and Acanthamoeba sp. KA/E21 with 98% homology. Phylogenetic analysis showed that the endosymbiont of CB/SI, the endosymbiont of KA/E21, Candidatus Amoebophilus asiaticus, the endosymbiont of Ixodes scapularis, and the endosymbiont of Encarsia pergandiella constitute a monophyletic lineage in phylogenetic tree.}, }
@article {pmid21822842, year = {2011}, author = {Pesaresi, P}, title = {Studying translation in Arabidopsis chloroplasts.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {774}, number = {}, pages = {209-224}, doi = {10.1007/978-1-61779-234-2_14}, pmid = {21822842}, issn = {1940-6029}, mesh = {Arabidopsis/*genetics/growth &amp; development ; Arabidopsis Proteins/metabolism ; Blotting, Northern ; Chloroplast Proteins/isolation &amp; purification ; Chloroplasts/*genetics ; Electrophoresis, Polyacrylamide Gel ; *Genetic Techniques ; Plant Leaves/metabolism ; Polyribosomes/metabolism ; Protein Biosynthesis/*genetics ; Staining and Labeling ; Thylakoids/metabolism ; }, abstract = {Chloroplasts as descendents of a cyanobacterial endosymbiont have retained, during evolution, their own genome together with the gene expression machinery, including the translation apparatus. Therefore, chloroplast protein synthesis is not only a key process in organello biogenesis and maintenance, but it also represents the major regulatory step in chloroplast gene expression. In fact, several independent evidences have shown that the accumulation of template messengers is not limiting in the expression of chloroplast genes. On the contrary, translation regulatory processes based on selection of translatable mRNA by either nucleus-encoded activation factors or sensors of the assembly status of chloroplast multiprotein complexes have been reported. Additionally, we have shown that organelle translation rate triggers an organelle-to-nucleus signaling cascade aimed to modulate nuclear gene expression according to the organelle's needs. Therefore, the study of chloroplast translation appears to be essential for the comprehension of several aspects of chloroplast activity. Here, we describe the in vivo pulse-chase and the polysome isolation approaches. Taken together, the two methods allow one to assess rates of protein synthesis and degradation as well as defects during the initial steps of protein synthesis.}, }
@article {pmid21814289, year = {2012}, author = {Matsuura, Y and Kikuchi, Y and Hosokawa, T and Koga, R and Meng, XY and Kamagata, Y and Nikoh, N and Fukatsu, T}, title = {Evolution of symbiotic organs and endosymbionts in lygaeid stinkbugs.}, journal = {The ISME journal}, volume = {6}, number = {2}, pages = {397-409}, pmid = {21814289}, issn = {1751-7370}, mesh = {Animals ; *Biological Evolution ; Female ; Gammaproteobacteria/*classification/genetics/*physiology ; Gastrointestinal Tract/microbiology ; Genes, Bacterial/genetics ; Hemiptera/*microbiology/ultrastructure ; Male ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; Species Specificity ; *Symbiosis ; }, abstract = {We investigated seed bugs of the genus Nysius (Insecta: Hemiptera: Lygaeidae) for their symbiotic bacteria. From all the samples representing 4 species, 18 populations and 281 individuals, specific bacterial 16S rRNA gene sequences were consistently identified, which formed a distinct clade in the Gammaproteobacteria. In situ hybridization showed that the bacterium was endocellularly localized in a pair of large bacteriomes that were amorphous in shape, deep red in color, and in association with gonads. In the ovary of adult females, the endosymbiont was also localized in the 'infection zone' in the middle of each germarium and in the 'symbiont ball' at the anterior pole of each oocyte, indicating vertical transmission of the endosymbiont through the ovarial passage. Phylogenetic analyses based on bacterial 16S rRNA, groEL and gyrB genes consistently supported a coherent monophyly of the Nysius endosymbionts. The possibility of a sister relationship to 'Candidatus Kleidoceria schneideri', the bacteriome-associated endosymbiont of a lygaeid bug Kleidocerys resedae, was statistically rejected, indicating independent evolutionary origins of the endosymbionts in the Lygaeidae. The endosymbiont genes consistently exhibited AT-biased nucleotide compositions and accelerated rates of molecular evolution, and the endosymbiont genome was only 0.6 Mb in size. The endosymbiont phylogeny was congruent with the host insect phylogeny, suggesting strict vertical transmission and host-symbiont co-speciation over evolutionary time. Based on these results, we discuss the evolution of bacteriomes and endosymbionts in the Heteroptera, most members of which are associated with gut symbiotic bacteria. The designation 'Candidatus Schneideria nysicola' is proposed for the endosymbiont clade.}, }
@article {pmid21802404, year = {2012}, author = {Pierron, D and Wildman, DE and Hüttemann, M and Markondapatnaikuni, GC and Aras, S and Grossman, LI}, title = {Cytochrome c oxidase: evolution of control via nuclear subunit addition.}, journal = {Biochimica et biophysica acta}, volume = {1817}, number = {4}, pages = {590-597}, pmid = {21802404}, issn = {0006-3002}, support = {R24 GM065580/GM/NIGMS NIH HHS/United States ; GM65580/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Cell Nucleus/*genetics ; DNA, Mitochondrial/*genetics/metabolism ; Electron Transport Complex IV/*genetics/metabolism ; *Evolution, Molecular ; Humans ; Models, Genetic ; Oxidative Phosphorylation ; Oxygen/metabolism ; Protein Subunits/genetics/metabolism ; }, abstract = {According to theory, present eukaryotic cells originated from a beneficial association between two free-living cells. Due to this endosymbiotic event the pre-eukaryotic cell gained access to oxidative phosphorylation (OXPHOS), which produces more than 15 times as much ATP as glycolysis. Because cellular ATP needs fluctuate and OXPHOS both requires and produces entities that can be toxic for eukaryotic cells such as ROS or NADH, we propose that the success of endosymbiosis has largely depended on the regulation of endosymbiont OXPHOS. Several studies have presented cytochrome c oxidase as a key regulator of OXPHOS; for example, COX is the only complex of mammalian OXPHOS with known tissue-specific isoforms of nuclear encoded subunits. We here discuss current knowledge about the origin of nuclear encoded subunits and the appearance of different isozymes promoted by tissue and cellular environments such as hypoxia. We also review evidence for recent selective pressure acting on COX among vertebrates, particularly in primate lineages, and discuss the unique pattern of co-evolution between the nuclear and mitochondrial genomes. Finally, even though the addition of nuclear encoded subunits was a major event in eukaryotic COX evolution, this does not lead to emergence of a more efficient COX, as might be expected from an anthropocentric point of view, for the "higher" organism possessing large brains and muscles. The main function of these subunits appears to be "only" to control the activity of the mitochondrial subunits. We propose that this control function is an as yet under appreciated key point of evolution. Moreover, the importance of regulating energy supply may have caused the addition of subunits encoded by the nucleus in a process comparable to a "domestication scenario" such that the host tends to control more and more tightly the ancestral activity of COX performed by the mtDNA encoded subunits.}, }
@article {pmid21792226, year = {2012}, author = {Raychoudhury, R and Werren, JH}, title = {Host genotype changes bidirectional to unidirectional cytoplasmic incompatibility in Nasonia longicornis.}, journal = {Heredity}, volume = {108}, number = {2}, pages = {105-114}, pmid = {21792226}, issn = {1365-2540}, mesh = {Animals ; Cytoplasm/genetics/*microbiology/physiology ; Female ; Genotype ; Host Specificity ; Male ; Reproduction ; Symbiosis ; Wasps/*genetics/microbiology/physiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia are the most abundant maternally inherited endosymbionts of insects and cause various reproductive alterations in their hosts. One such manipulation is cytoplasmic incompatibility (CI), which is a sperm-egg incompatibility typically resulting in zygotic death. Nasonia longicornis (Hymenoptera: Pteromalidae) has an A supergroup and two closely related B supergroup Wolbachia infections. The B supergroup bacteria co-diverged in this host genus. Both triple (wNlonAwNlonB1wNlonB2) and double infections (wNlonAwNlonB1, wNlonAwNlonB2) have been obtained from the field. In the present study, CI was determined among the three Wolbachia types in different host genetic backgrounds. Results show that host genetic background determines whether bidirectional CI or unidirectional CI occurs between the two closely related B group Wolbachia. Results show that the wNlonB1-infected males are bidirectionally incompatible with wNlonB2 in their 'native' nuclear genetic background, whereas wNlonB1 males are compatible with wNlonB2 in two other N. longicornis genetic backgrounds, resulting in unidirectional CI. In contrast, wNlonB2-infected males are incompatible with wNlonB1 females in all three host genetic backgrounds. These changes in incompatibility are not due to the loss of the bacteria. We hypothesize that a repressor gene for sperm modification by wNlonB1 is segregating in N. longicornis populations. The relevance of these findings to the potential role of Wolbachia in host-reproductive divergence and speciation is discussed.}, }
@article {pmid21789233, year = {2011}, author = {Arthofer, W and Riegler, M and Schuler, H and Schneider, D and Moder, K and Miller, WJ and Stauffer, C}, title = {Allele intersection analysis: a novel tool for multi locus sequence assignment in multiply infected hosts.}, journal = {PloS one}, volume = {6}, number = {7}, pages = {e22198}, pmid = {21789233}, issn = {1932-6203}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {*Alleles ; Animals ; Bacterial Typing Techniques ; Base Sequence ; Bias ; Ceratitis capitata/microbiology ; Computer Simulation ; Host-Pathogen Interactions/*genetics ; Multilocus Sequence Typing/*methods ; Species Specificity ; Wolbachia/*classification/*genetics ; }, abstract = {Wolbachia are wide-spread, endogenous α-Proteobacteria of arthropods and filarial nematodes. 15-75% of all insect species are infected with these endosymbionts that alter their host's reproduction to facilitate their spread. In recent years, many insect species infected with multiple Wolbachia strains have been identified. As the endosymbionts are not cultivable outside living cells, strain typing relies on molecular methods. A Multi Locus Sequence Typing (MLST) system was established for standardizing Wolbachia strain identification. However, MLST requires hosts to harbour individual and not multiple strains of supergroups without recombination. This study revisits the applicability of the current MLST protocols and introduces Allele Intersection Analysis (AIA) as a novel approach. AIA utilizes natural variations in infection patterns and allows correct strain assignment of MLST alleles in multiply infected host species without the need of artificial strain segregation. AIA identifies pairs of multiply infected individuals that share Wolbachia and differ in only one strain. In such pairs, the shared MLST sequences can be used to assign alleles to distinct strains. Furthermore, AIA is a powerful tool to detect recombination events. The underlying principle of AIA may easily be adopted for MLST approaches in other uncultivable bacterial genera that occur as multiple strain infections and the concept may find application in metagenomic high-throughput parallel sequencing projects.}, }
@article {pmid21786068, year = {2012}, author = {Shiny, C and Krushna, NS and Haripriya, K and Babu, S and Elango, S and Manokaran, G and Narayanan, RB}, title = {Recombinant Wolbachia surface protein (WSP)-induced T cell responses in Wuchereria bancrofti infections.}, journal = {Parasitology research}, volume = {110}, number = {2}, pages = {787-797}, pmid = {21786068}, issn = {1432-1955}, support = {Z99 AI999999//Intramural NIH HHS/United States ; }, mesh = {Animals ; Antigens, CD/analysis ; Antigens, Differentiation, T-Lymphocyte/analysis ; Bacterial Outer Membrane Proteins/*immunology ; CTLA-4 Antigen/analysis ; Cell Proliferation ; Cytokines/metabolism ; Elephantiasis, Filarial/*immunology ; Humans ; Interleukin-2 Receptor alpha Subunit/analysis ; Interleukin-7 Receptor alpha Subunit/analysis ; L-Selectin/analysis ; Lectins, C-Type/analysis ; Leukocytes, Mononuclear/chemistry/immunology ; Membrane Proteins/*immunology ; T-Lymphocytes/chemistry/*immunology ; T-Lymphocytes, Regulatory/chemistry/immunology ; Wolbachia/*immunology ; Wuchereria bancrofti/*microbiology/pathogenicity ; }, abstract = {Human lymphatic filariasis is a debilitating parasitic disease characterized by downregulation of the host's immune response in asymptomatic carriers along with profound hyperreactivity in chronic patients apart from putatively immune endemic normals. The endosymbiont Wolbachia, a bacterium of filarial nematodes has received much attention as possible chemotherapeutic target and its involvement in disease pathogenesis. The role of recombinant Wolbachia surface protein (rWSP), one of the most abundantly expressed proteins of the endosymbiont, in modulating cell-mediated immune responses in patients harboring Wuchereria bancrofti infections was evaluated in the current study. rWSP-induced lymphoproliferation with peripheral blood mononuclear cells suggested an impaired proliferative response in asymptomatic microfilaremic (MF) and symptomatic chronic pathology (CP) patients compared to endemic normals (EN). This was further supported by a significantly diminished expression of CD69 along with elevated levels of CD127 and CD62L in filarial patients (MF and CP) compared to EN. Further, rWSP induced the expression of regulatory T cell markers CTLA-4 and CD25 along with suppressor cytokines IL-10 and TGF-β in MF and CP patients compared to EN. However, the rWSP-stimulated expression of IFN-γ was diminished significantly in filarial patients compared to endemic normals. Thus, these findings suggest that WSP may also contribute to the suppression of immune responses seen in filarial patients.}, }
@article {pmid21782824, year = {2011}, author = {Chen, YH and Bernal, CC and Tan, J and Horgan, FG and Fitzgerald, MA}, title = {Planthopper "adaptation" to resistant rice varieties: changes in amino acid composition over time.}, journal = {Journal of insect physiology}, volume = {57}, number = {10}, pages = {1375-1384}, doi = {10.1016/j.jinsphys.2011.07.002}, pmid = {21782824}, issn = {1879-1611}, mesh = {*Adaptation, Biological ; Amino Acids/*metabolism ; Animals ; Female ; Hemiptera/growth &amp; development/*metabolism/microbiology ; Nitrogen/*metabolism ; Nymph/growth &amp; development ; Oryza/metabolism/*parasitology ; Symbiosis ; }, abstract = {The brown planthopper, Nilaparvata lugens, shows considerable geographic and temporal variability in its response to varieties of cultivated rice. N. lugens has repeatedly "adapted" to resistant rice varieties; however, the physiological changes underlying planthopper adaptation are poorly understood. Endosymbionts within planthoppers, such as yeast-like endosymbionts (YLS) could play a role as they produce essential amino acids for planthoppers. We used a full factorial study to determine how natal rice variety, exposed rice variety, YLS presence, and the number of reared generations affected nymphal development, planthopper total nitrogen content, and planthopper hydrolyzed amino acid profiles. Nymphal development was strongly influenced by a four-way interaction between the exposed rice variety, natal rice variety, number of reared generations, and YLS presence. While symbiosis improved nymphal performance in the 8th generation, it appeared to be a drain on nymphs in the 11th generation, when the aposymbiotic nymphs actually showed higher performance than the symbiotic nymphs. This suggests that the symbiotic relationship may be acting beneficially in one generation while acting as a drain during another generation. Aposymbiotic planthoppers reared for 11 generations had a higher proportional concentration of rare amino acids than those reared for 8 generations, indicating that the planthopper itself appears to improve its ability to acquire rare amino acids. Therefore, the change in amino acid composition of planthoppers suggests an underlying change in protein expression or amino acid metabolism over time.}, }
@article {pmid21782817, year = {2011}, author = {Melnikow, E and Xu, S and Liu, J and Li, L and Oksov, Y and Ghedin, E and Unnasch, TR and Lustigman, S}, title = {Interaction of a Wolbachia WSP-like protein with a nuclear-encoded protein of Brugia malayi.}, journal = {International journal for parasitology}, volume = {41}, number = {10}, pages = {1053-1061}, pmid = {21782817}, issn = {1879-0135}, support = {R01 AI072465/AI/NIAID NIH HHS/United States ; R01 AI072465-03/AI/NIAID NIH HHS/United States ; AI072465/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/*metabolism ; Brugia malayi/genetics/*metabolism/*microbiology ; Enzyme-Linked Immunosorbent Assay ; Female ; *Host-Parasite Interactions ; Mice ; Microscopy ; Protein Binding ; *Protein Interaction Mapping ; Wolbachia/genetics/*metabolism ; }, abstract = {The Brugia malayi endosymbiont Wolbachia has recently been shown to be essential for its host's survival and development. However, relatively little is known about Wolbachia proteins that interact with the filarial host and which might be important in maintaining the obligate symbiotic relationship. The Wolbachia surface proteins (WSPs) are members of the outer membrane protein family and we hypothesise that they might be involved in the Wolbachia-Brugia symbiotic relationship. Notably, immunolocalisation studies of two WSP members, WSP-0432 and WSP-0284 in B. malayi female adult worms showed that the corresponding proteins are not only present on the surface of Wolbachia but also in the host tissues, with WSP-0284 more abundant in the cuticle, hypodermis and the nuclei within the embryos. These results confirmed that WSPs might be secreted by Wolbachia into the worm's tissue. Our present studies focus on the potential involvement of WSP-0284 in the symbiotic relationship of Wolbachia with its filarial host. We show that WSP-0284 binds specifically to B. malayi crude protein extracts. Furthermore, a fragment of the hypothetical B. malayi protein (Bm1_46455) was found to bind WSP-0284 by panning of a B. malayi cDNA library. The interaction of WSP-0284 and this protein was further confirmed by ELISA and pull-down assays. Localisation by immunoelectron microscopy within Wolbachia cells as well as in the worm's tissues, cuticle and nuclei within embryos established that both proteins are present in similar locations within the parasite and the bacteria. Identifying such specific interactions between B. malayi and Wolbachia proteins should lead to a better understanding of the molecular basis of the filarial nematode and Wolbachia symbiosis.}, }
@article {pmid21782276, year = {2011}, author = {Aebi, A and Neumann, P}, title = {Endosymbionts and honey bee colony losses?.}, journal = {Trends in ecology &amp; evolution}, volume = {26}, number = {10}, pages = {494}, doi = {10.1016/j.tree.2011.06.008}, pmid = {21782276}, issn = {1872-8383}, mesh = {Animals ; Bacteria ; Bees/*microbiology/parasitology/*physiology/virology ; Population Dynamics ; Symbiosis ; }, }
@article {pmid21777587, year = {2011}, author = {Paterson, GN and Rittig, M and Siddiqui, R and Khan, NA}, title = {Is Acanthamoeba pathogenicity associated with intracellular bacteria?.}, journal = {Experimental parasitology}, volume = {129}, number = {2}, pages = {207-210}, doi = {10.1016/j.exppara.2011.06.017}, pmid = {21777587}, issn = {1090-2449}, mesh = {Acanthamoeba/*microbiology/*pathogenicity/ultrastructure ; Acanthamoeba Keratitis/parasitology ; Bacteria/genetics/*isolation &amp; purification/pathogenicity/ultrastructure ; Brain/parasitology/pathology ; Cells, Cultured ; Cornea/parasitology ; DNA, Bacterial/isolation &amp; purification ; Endothelium, Vascular/cytology/parasitology/pathology ; Humans ; Microscopy, Electron, Transmission ; Polymerase Chain Reaction ; Symbiosis/*physiology ; Virulence/physiology ; }, abstract = {In addition to the possible role of Acanthamoeba as an evolutionary precursor of pathogenicity in microbial pathogens, it has been suggested that intracellular bacteria or other microbial endosymbionts may also enhance the pathogenicity of Acanthamoeba. Using transmission electron microscopy, polymerase chain reaction and simple culturing, our findings did not reveal any apparent evidence of microbial presence intracellularly of a recently recovered clinical isolate of Acanthamoeba. Based on these findings, it is tempting to speculate that the virulence of Acanthamoeba may not be attributed to the pathogenicity of the endosymbiont alone.}, }
@article {pmid21775189, year = {2011}, author = {Inoue, K}, title = {Emerging roles of the chloroplast outer envelope membrane.}, journal = {Trends in plant science}, volume = {16}, number = {10}, pages = {550-557}, doi = {10.1016/j.tplants.2011.06.005}, pmid = {21775189}, issn = {1878-4372}, mesh = {Actins/metabolism/physiology ; Chloroplasts/*ultrastructure ; Intracellular Membranes/*physiology ; Lipid Metabolism ; Models, Biological ; Plant Proteins/metabolism ; Protein Transport ; }, abstract = {The chloroplast is essential for the viability of plants. It is enclosed by a double-membrane envelope that originated from the outer and plasma membranes of a cyanobacterial endosymbiont. Chloroplast biogenesis depends on binary fission and import of nuclear-encoded proteins. Our understanding of the mechanisms and evolutionary origins of these processes has been greatly advanced by recent genetic and biochemical studies on envelope-localized multiprotein machines. Furthermore, the latest studies on outer envelope proteins have provided molecular insights into organelle movement and membrane lipid remodeling, activities that are vital for plant survival under diverse environmental conditions. Ongoing and future research on the chloroplast outer envelope should add to our knowledge of organelle biology and the evolution of eukaryotic cells.}, }
@article {pmid21774575, year = {2011}, author = {Asensio, AC and Marino, D and James, EK and Ariz, I and Arrese-Igor, C and Aparicio-Tejo, PM and Arredondo-Peter, R and Moran, JF}, title = {Expression and localization of a Rhizobium-derived cambialistic superoxide dismutase in pea (Pisum sativum) nodules subjected to oxidative stress.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {24}, number = {10}, pages = {1247-1257}, doi = {10.1094/MPMI-10-10-0253}, pmid = {21774575}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Bacterial Proteins/genetics/metabolism ; Base Sequence ; DNA, Bacterial/genetics ; Genes, Bacterial ; Genes, Plant ; Host-Pathogen Interactions/drug effects/genetics/physiology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Nitrogen Fixation/drug effects ; Oxidative Stress/drug effects ; Paraquat/pharmacology ; Peas/*enzymology/*genetics/microbiology/ultrastructure ; Rhizobium/*enzymology/*genetics ; Subcellular Fractions/enzymology ; Superoxide Dismutase/*genetics/*metabolism ; }, abstract = {Two phylogenetically unrelated superoxide dismutase (SOD) families, i.e., CuZnSOD (copper and zinc SOD) and FeMn-CamSOD (iron, manganese, or cambialistic SOD), eliminate superoxide radicals in different locations within the plant cell. CuZnSOD are located within the cytosol and plastids, while the second family of SOD, which are considered to be of bacterial origin, are usually located within organelles, such as mitochondria. We have used the reactive oxygen species-producer methylviologen (MV) to study SOD isozymes in the indeterminate nodules on pea (Pisum sativum). MV caused severe effects on nodule physiology and structure and also resulted in an increase in SOD activity. Purification and N-terminal analysis identified CamSOD from the Rhizobium leguminosarum endosymbiont as one of the most active SOD in response to the oxidative stress. Fractionation of cell extracts and immunogold labeling confirmed that the CamSOD was present in both the bacteroids and the cytosol (including the nuclei, plastids, and mitochondria) of the N-fixing cells, and also within the uninfected cortical and interstitial cells. These findings, together with previous reports of the occurrence of FeSOD in determinate nodules, indicate that FeMnCamSOD have specific functions in legumes, some of which may be related to signaling between plant and bacterial symbionts, but the occurrence of one or more particular isozymes depends upon the nodule type.}, }
@article {pmid21757490, year = {2011}, author = {Andrade, IDS and Vianez-Júnior, JL and Goulart, CL and Homblé, F and Ruysschaert, JM and Almeida von Krüger, WM and Bisch, PM and de Souza, W and Mohana-Borges, R and Motta, MCM}, title = {Characterization of a porin channel in the endosymbiont of the trypanosomatid protozoan Crithidia deanei.}, journal = {Microbiology (Reading, England)}, volume = {157}, number = {Pt 10}, pages = {2818-2830}, doi = {10.1099/mic.0.049247-0}, pmid = {21757490}, issn = {1465-2080}, mesh = {Amino Acid Sequence ; Bacteria/classification/genetics/isolation &amp; purification/*metabolism ; Bacterial Physiological Phenomena ; Bacterial Proteins/*chemistry/genetics/metabolism ; Crithidia/*microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; Porins/*chemistry/genetics/metabolism ; Sequence Alignment ; *Symbiosis ; }, abstract = {Crithidia deanei is a trypanosomatid protozoan that harbours a symbiotic bacterium. The partners maintain a mutualistic relationship, thus constituting an excellent model for studying metabolic exchanges between the host and the symbiont, the origin of organelles and cellular evolution. According to molecular analysis, symbionts of different trypanosomatid species share high identity and descend from a common ancestor, a β-proteobacterium of the genus Bordetella. The endosymbiont is surrounded by two membranes, like Gram-negative bacteria, but its envelope presents special features, since phosphatidylcholine is a major membrane component and the peptidoglycan layer is highly reduced, as described in other obligate intracellular bacteria. Like the process that generated mitochondria and plastids, the endosymbiosis in trypanosomatids depends on pathways that facilitate the intensive metabolic exchanges between the bacterium and the host protozoan. A search of the annotated symbiont genome database identified one sequence with identity to porin-encoding genes of the genus Bordetella. Considering that the symbiont outer membrane has a great accessibility to cytoplasm host factors, it was important to characterize this single porin-like protein using biochemical, molecular, computational and ultrastructural approaches. Antiserum against the recombinant porin-like molecule revealed that it is mainly located in the symbiont envelope. Secondary structure analysis and comparative modelling predicted the protein 3D structure as an 18-domain β-barrel, which is consistent with porin channels. Electrophysiological measurements showed that the porin displays a slight preference for cations over anions. Taken together, the data presented herein suggest that the C. deanei endosymbiont porin is phylogenetically and structurally similar to those described in Gram-negative bacteria, representing a diffusion channel that might contribute to the exchange of nutrients and metabolic precursors between the symbiont and its host cell.}, }
@article {pmid21751349, year = {2011}, author = {Peng, SE and Chen, WN and Chen, HK and Lu, CY and Mayfield, AB and Fang, LS and Chen, CS}, title = {Lipid bodies in coral-dinoflagellate endosymbiosis: proteomic and ultrastructural studies.}, journal = {Proteomics}, volume = {11}, number = {17}, pages = {3540-3555}, doi = {10.1002/pmic.201000552}, pmid = {21751349}, issn = {1615-9861}, mesh = {Animals ; Anthozoa/*physiology ; Dinoflagellida/*physiology ; Electrophoresis, Polyacrylamide Gel ; Lipids/*chemistry ; Proteome/*analysis ; *Symbiosis ; Tandem Mass Spectrometry ; }, abstract = {Gastrodermal lipid bodies (LBs) are organelles involved in the regulation of the mutualistic endosymbiosis between reef-building corals and their dinoflagellate endosymbionts (genus Symbiodinium). As their molecular composition remains poorly defined, we herein describe the first gastrodermal LB proteome and examine in situ morphology of LBs in order to provide insight into their structure and function. After tissue separation of the tentacles of the stony coral Euphyllia glabrescens, buoyant LBs of the gastroderm encompassing a variety of sizes (0.5-4 μm in diameter) were isolated after two cycles of subcellular fractionation via stepwise sucrose gradient ultracentrifugation and detergent washing. The purity of the isolated LBs was demonstrated by their high degree of lipid enrichment and as well as the absence of contaminating proteins of the host cell and Symbiodinium. LB-associated proteins were then purified, subjected to SDS-PAGE, and identified by MS using an LC-nano-ESI-MS/MS. A total of 42 proteins were identified within eight functional groups, including metabolism, intracellular trafficking, the stress response/molecular modification and development. Ultrastructural analyses of LBs in situ showed that they exhibit defined morphological characteristics, including a high-electron density resulting from a distinct lipid composition from that of the lipid droplets of mammalian cells. Coral LBs were also characterized by the presence of numerous electron-transparent inclusions of unknown origin and composition. Both proteomic and ultrastructural observations seem to suggest that both Symbiodinium and host organelles, such as the ER, are involved in LB biogenesis.}, }
@article {pmid21741306, year = {2012}, author = {Danne, JC and Gornik, SG and Waller, RF}, title = {An assessment of vertical inheritance versus endosymbiont transfer of nucleus-encoded genes for mitochondrial proteins following tertiary endosymbiosis in Karlodinium micrum.}, journal = {Protist}, volume = {163}, number = {1}, pages = {76-90}, doi = {10.1016/j.protis.2011.03.002}, pmid = {21741306}, issn = {1618-0941}, mesh = {Cell Nucleus/*genetics ; Dinoflagellida/classification/*genetics/physiology ; Gene Transfer, Horizontal ; Mitochondrial Proteins/*genetics ; Molecular Sequence Data ; Phylogeny ; Plastids/genetics ; Protozoan Proteins/*genetics ; Rhodophyta/*genetics/physiology ; *Symbiosis ; }, abstract = {Most photosynthetic dinoflagellates harbour a red alga-derived secondary plastid. In the dinoflagellate Karlodinium micrum, this plastid was replaced by a subsequent endosymbiosis, resulting in a tertiary plastid derived from a haptophyte. Evolution of endosymbionts entails substantial relocation of endosymbiont genes to the host nucleus: a process called endosymbiotic gene transfer (EGT). In K. micrum, numerous plastid genes from the haptophyte nucleus are found in the host nucleus, providing evidence for EGT in this system. In other cases of endosymbiosis, notably ancient primary endosymbiotic events, EGT has been inferred to contribute to remodeling of other cell functions by expression of proteins in compartments other than the endosymbiont from which they derived. K. micrum provides a more recently derived endosymbiotic system to test for evidence of EGT and gain of function in non-plastid compartments. In this study, we test for gain of haptophyte-derived proteins for mitochondrial function in K. micrum. Using molecular phylogenies we have analysed whether nucleus-encoded mitochondrial proteins were inherited by EGT from the haptophyte endosymbiont, or vertically inherited from the dinoflagellate host lineage. From this dataset we found no evidence of haptophyte-derived mitochondrial genes, and the only cases of non-vertical inheritance were genes derived from lateral gene transfer events.}, }
@article {pmid21740495, year = {2011}, author = {Herren, JK and Lemaitre, B}, title = {Spiroplasma and host immunity: activation of humoral immune responses increases endosymbiont load and susceptibility to certain Gram-negative bacterial pathogens in Drosophila melanogaster.}, journal = {Cellular microbiology}, volume = {13}, number = {9}, pages = {1385-1396}, doi = {10.1111/j.1462-5822.2011.01627.x}, pmid = {21740495}, issn = {1462-5822}, mesh = {Animals ; Drosophila melanogaster/*immunology/*microbiology ; Immunity, Humoral/*immunology/physiology ; Phagocytosis/immunology/physiology ; Spiroplasma/*immunology/*physiology ; Symbiosis/immunology ; }, abstract = {Spiroplasma poulsonii and its relatives are facultative, vertically transmitted endosymbionts harboured by several Drosophila species. Their long-term survival requires not only evasion of host immunity, but also that Spiroplasma does not have a net detrimental effect on host fitness. These requirements provide the central framework for interactions between host and endosymbiont. We use Drosophila melaogaster as a model to unravel aspects of the mechanistic basis of endosymbiont-host immune interactions. Here we show that Spiroplasma does not activate an immune response in Drosophila and is not susceptible to either the cellular or humoral arms of the Drosophila immune system. We gain unexpected insight into host factors that can promote Spiroplasma growth by showing that activation of Toll and Imd immune pathways actually increases Sprioplasma titre. Spiroplasma-mediated protection is not observed for variety of fungal and bacterial pathogens and Spiroplasma actually increases susceptibility of Drosophila to certain Gram-negative pathogens. Finally, we show that the growth of endosymbiotic Spiroplasma is apparently self-regulated, as suggested by the unhindered proliferation of non-endosymbiotic Spiroplasma citri in fly haemolymph.}, }
@article {pmid21738524, year = {2011}, author = {Stewart, FJ and Dmytrenko, O and Delong, EF and Cavanaugh, CM}, title = {Metatranscriptomic analysis of sulfur oxidation genes in the endosymbiont of solemya velum.}, journal = {Frontiers in microbiology}, volume = {2}, number = {}, pages = {134}, pmid = {21738524}, issn = {1664-302X}, abstract = {Thioautotrophic endosymbionts in the Domain Bacteria mediate key sulfur transformations in marine reducing environments. However, the molecular pathways underlying symbiont metabolism and the extent to which these pathways are expressed in situ are poorly characterized for almost all symbioses. This is largely due to the difficulty of culturing symbionts apart from their hosts. Here, we use pyrosequencing of community RNA transcripts (i.e., the metatranscriptome) to characterize enzymes of dissimilatory sulfur metabolism in the model symbiosis between the coastal bivalve Solemya velum and its intracellular thioautotrophic symbionts. High-throughput sequencing of total RNA from the symbiont-containing gill of a single host individual generated 1.6 million sequence reads (500 Mbp). Of these, 43,735 matched Bacteria protein-coding genes in BLASTX searches of the NCBI database. The taxonomic identities of the matched genes indicated relatedness to diverse species of sulfur-oxidizing Gammaproteobacteria, including other thioautotrophic symbionts and the purple sulfur bacterium Allochromatium vinosum. Manual querying of these data identified 28 genes from diverse pathways of sulfur energy metabolism, including the dissimilatory sulfite reductase (Dsr) pathway for sulfur oxidation to sulfite, the APS pathway for sulfite oxidation, and the Sox pathway for thiosulfate oxidation. In total, reads matching sulfur energy metabolism genes represented 7% of the Bacteria mRNA pool. Together, these data highlight the dominance of thioautotrophy in the context of symbiont community metabolism, identify the likely pathways mediating sulfur oxidation, and illustrate the utility of metatranscriptome sequencing for characterizing community gene transcription of uncultured symbionts.}, }
@article {pmid21738010, year = {2011}, author = {Eleftherianos, I and Schneider, D}, title = {Drosophila immunity research on the move.}, journal = {Fly}, volume = {5}, number = {3}, pages = {247-254}, doi = {10.4161/fly.5.3.17028}, pmid = {21738010}, issn = {1933-6942}, mesh = {*Adaptive Immunity ; Animals ; Biological Evolution ; Congresses as Topic ; Drosophila/genetics/*immunology/microbiology ; Female ; Gastrointestinal Tract/immunology ; Host-Pathogen Interactions ; *Immunity, Innate ; Male ; Symbiosis ; Virulence Factors/physiology ; }, abstract = {Drosophila has been established as useful model for infectious diseases because it allows large numbers of whole animals to be studied and provides powerful genetic tools and conservation with signaling and pathogenesis mechanisms in vertebrates. During the past twenty years, significant progress has been made on the characterization of innate immune responses against various pathogenic organisms in flies (Fig. 1). In this year's Drosophila Research Conference, which was held in San Diego (March 30-April 3) and sponsored by the Genetics Society of America, the immunity and pathogenesis session comprised seven platform presentations and 34 posters that highlighted the latest advances in Drosophila infection and immunity field. The presented work covered a wide range of studies from immune signaling pathways and the molecular basis of humoral and cellular immune mechanisms to the role of endosymbionts in fly immune function and effects of immune priming. Here, we give an overview of the presented work and we explain how these findings will open new avenues in Drosophila immunity research.}, }
@article {pmid21734243, year = {2011}, author = {Tamarozzi, F and Halliday, A and Gentil, K and Hoerauf, A and Pearlman, E and Taylor, MJ}, title = {Onchocerciasis: the role of Wolbachia bacterial endosymbionts in parasite biology, disease pathogenesis, and treatment.}, journal = {Clinical microbiology reviews}, volume = {24}, number = {3}, pages = {459-468}, pmid = {21734243}, issn = {1098-6618}, mesh = {Animals ; Diethylcarbamazine/adverse effects/therapeutic use ; Filaricides/adverse effects/therapeutic use ; Humans ; Inflammation/chemically induced/microbiology ; Ivermectin/adverse effects/therapeutic use ; Onchocerca volvulus/*microbiology ; Onchocerciasis, Ocular/drug therapy/*microbiology/*parasitology ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {The discovery of Wolbachia intracellular bacteria within filarial nematodes, including Onchocerca volvulus, the causative agent of onchocerciasis or "river blindness," has delivered a paradigm shift in our understanding of the parasite's biology, to where we now know that the bacterial endosymbionts are essential for normal development of larvae and embryos and may support the long-term survival of adult worms. The apparent mutualistic dependency has also offered a novel approach to the treatment of onchocerciasis through the use of antibiotics to eliminate Wolbachia, delivering for the first time a treatment which has significant macrofilaricidal efficacy. Studies with other filarial nematode species have also highlighted a role for Wolbachia in transmission and infection of the mammalian host through a fascinating manipulation of mast cell-mediated vasodilation to enhance infectivity of vector-borne larvae. Wolbachia has also been identified as the principal driver of innate and adaptive Th1 inflammatory immunity, which can either contribute to disease pathogenesis or, with the Wolbachia-mediated recruitment of mast cells, enhance infectivity. The Wolbachia activation of innate inflammation also drives inflammatory adverse events in response to chemotherapy with either diethylcarbamazine (DEC) or ivermectin. In this review we summarize the experimental and field trial data which have uncovered the importance of Wolbachia symbiosis in onchocerciasis.}, }
@article {pmid21731626, year = {2011}, author = {Ferri, E and Bain, O and Barbuto, M and Martin, C and Lo, N and Uni, S and Landmann, F and Baccei, SG and Guerrero, R and de Souza Lima, S and Bandi, C and Wanji, S and Diagne, M and Casiraghi, M}, title = {New insights into the evolution of Wolbachia infections in filarial nematodes inferred from a large range of screened species.}, journal = {PloS one}, volume = {6}, number = {6}, pages = {e20843}, pmid = {21731626}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; *Biological Evolution ; DNA, Ribosomal/genetics ; Female ; Filarioidea/cytology/*isolation &amp; purification/*microbiology ; Fluorescence ; Gram-Negative Bacterial Infections/*genetics/*microbiology ; Host Specificity ; Host-Pathogen Interactions ; Phylogeny ; Polymerase Chain Reaction ; Propidium/metabolism ; Species Specificity ; Wolbachia/cytology/genetics/*physiology ; }, abstract = {BACKGROUND: Wolbachia are intriguing symbiotic endobacteria with a peculiar host range that includes arthropods and a single nematode family, the Onchocercidae encompassing agents of filariases. This raises the question of the origin of infection in filariae. Wolbachia infect the female germline and the hypodermis. Some evidences lead to the theory that Wolbachia act as mutualist and coevolved with filariae from one infection event: their removal sterilizes female filariae; all the specimens of a positive species are infected; Wolbachia are vertically inherited; a few species lost the symbiont. However, most data on Wolbachia and filaria relationships derive from studies on few species of Onchocercinae and Dirofilariinae, from mammals.<br><br>We investigated the Wolbachia distribution testing 35 filarial species, including 28 species and 7 genera and/or subgenera newly screened, using PCR, immunohistochemical staining, whole mount fluorescent analysis, and cocladogenesis analysis. (i) Among the newly screened Onchocercinae from mammals eight species harbour Wolbachia but for some of them, bacteria are absent in the hypodermis, or in variable density. (ii) Wolbachia are not detected in the pathological model Monanema martini and in 8, upon 9, species of Cercopithifilaria. (iii) Supergroup F Wolbachia is identified in two newly screened Mansonella species and in Cercopithifilaria japonica. (iv) Type F Wolbachia infect the intestinal cells and somatic female genital tract. (v) Among Oswaldofilariinae, Waltonellinae and Splendidofilariinae, from saurian, anuran and bird respectively, Wolbachia are not detected.<br><br>CONCLUSIONS/SIGNIFICANCE: The absence of Wolbachia in 63% of onchocercids, notably in the ancestral Oswaldofilariinae estimated 140 mya old, the diverse tissues or specimens distribution, and a recent lateral transfer in supergroup F Wolbachia, modify the current view on the role and evolution of the endosymbiont and their hosts. Further genomic analyses on some of the newly sampled species are welcomed to decipher the open questions.}, }
@article {pmid21728798, year = {2011}, author = {Kondo, NI and Tuda, M and Toquenaga, Y and Lan, YC and Buranapanichpan, S and Horng, SB and Shimada, M and Fukatsu, T}, title = {Wolbachia infections in world populations of bean beetles (Coleoptera: Chrysomelidae: Bruchinae) infesting cultivated and wild legumes.}, journal = {Zoological science}, volume = {28}, number = {7}, pages = {501-508}, doi = {10.2108/zsj.28.501}, pmid = {21728798}, issn = {0289-0003}, mesh = {Animals ; Asia ; Coleoptera/*microbiology ; Crops, Agricultural/parasitology ; DNA, Bacterial/isolation &amp; purification ; Fabaceae/*parasitology ; Middle East ; Phylogeny ; Uganda ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia endosymbionts are widespread among insects and other arthropods, often causing cytoplasmic incompatibility and other reproductive phenotypes in their hosts. Recently, possibilities of Wolbachia-mediated pest control and management have been proposed, and the bean beetles of the subfamily Bruchinae are known as serious pests of harvested and stored beans worldwide. Here we investigated Wolbachia infections in bean beetles from the world, representing seven genera, 20 species and 87 populations. Of 20 species examined, Wolbachia infections were detected in four species, Megabruchidius sophorae, Callosobruchus analis, C. latealbus and C. chinensis. Infection frequencies were partial in M. sophorae but perfect in the other species. In addition to C. chinensis described in the previous studies, C. latealbus was infected with two distinct Wolbachia strains. These Wolbachia strains from the bean beetles were phylogenetically not closely related to each other. Among world populations of C. chinensis, some Taiwanese populations on a wild leguminous plant, Rhynchosia minima, exhibited a peculiar Wolbachia infection pattern, suggesting the possibility that these populations comprise a distinct host race or a cryptic species.}, }
@article {pmid21723192, year = {2012}, author = {Leblond, JD and Lasiter, AD}, title = {Sterols of the green-pigmented, aberrant plastid dinoflagellate, Lepidodinium chlorophorum (Dinophyceae).}, journal = {Protist}, volume = {163}, number = {1}, pages = {38-46}, doi = {10.1016/j.protis.2011.05.003}, pmid = {21723192}, issn = {1618-0941}, mesh = {Dinoflagellida/classification/*metabolism ; Molecular Sequence Data ; Phylogeny ; Pigmentation ; Plastids/*metabolism ; Sterols/*metabolism ; }, abstract = {Lepidodinium chlorophorum is a green-pigmented dinoflagellate with an aberrant, tertiary plastid of chlorophyte ancestry rather than the typical red algal, secondary endosymbiont found in the vast majority of photosynthetic dinoflagellates. To date, only one published study exists on the galactolipids of L. chlorophorum, with nothing known about other lipid classes, including sterols. Our objectives were to examine the sterol composition of L. chlorophorum to determine if it produces any unique sterols with the potential to serve as biomarkers, and to compare it to members of the Chlorophyceae to determine if it has inherited any signature green algal sterols from its chlorophyte-derived endosymbiont. We have found that L. chlorophorum produces 6 sterols, all with a 4α-methyl substituent and none of which are known to occur in the Chlorophyceae. Rather, the sterols produced by L. chlorophorum place it within a group of dinoflagellates that have the common dinoflagellate sterols, dinosterol and dinostanol, as part of their sterol composition.}, }
@article {pmid23508470, year = {2011}, author = {Dhamodharan, R and Hoti, S and Sivapragasam, G and Das, M}, title = {Cloning and sequence analysis of partial genomic DNA coding for HtrA-type serine protease of Wolbachia from human lymphatic filarial parasite, Wuchereria bancrofti.}, journal = {Tropical parasitology}, volume = {1}, number = {2}, pages = {76-82}, pmid = {23508470}, issn = {2229-5070}, abstract = {BACKGROUND: Periplasmic serine proteases of HtrA type of Wolbachia have been shown to play a role in the pathogenesis of filarial disease.<br><br>AIMS: This study was aimed to sequence Wb-HtrA serine protease and analyze its phylogenetic position by comparing with other filarial and non-filarial nematode homologs.<br><br>MATERIALS AND METHODS: Partial HtrA gene fragment was amplified from DNA isolated from periodic and sub-periodic Wuchereria bancrofti parasites collected from Pondicherry and Nicobar islands, respectively. The amplicons were sequenced, and sequence homology and phylogenetic relationship with other filarial and non-filarial nematodes were analyzed.<br><br>RESULTS: Partial orthologue of HtrA-type serine protease from Wolbachia of W. bancrofti was amplified, cloned and sequenced. The deduced amino acid sequence exhibited 87%, 81% and 74% identity with the homologous Wolbachia proteases identified from Brugia malayi, Onchocerca volvulus and Drosophila melanogaster, respectively. The Wb-HtrA has arthologues in several proteobacteria with very high homology and hence is highly conserved not only among Wolbachia of filarial parasites but also across proteobacteria. The phylogenetic tree constructed using Neighbor-Joining method showed two main clusters: cluster-I containing bacteria that dwell in diverse habitats such as soil, fresh and marine waters and plants and cluster-II comprising Anaplasma sp. and Erlichia, and Wolbachia endosymbionts of insects and nematodes, in distinct groups.<br><br>CONCLUSIONS: HtrA-type serine protease from Wolbachia of W. bancrofti is highly conserved among filarial parasites. It will be of interest to know whether filarial Wolbachia HtrA type of serine protease might influence apoptosis and lymphatic epithelium, thereby playing a role in the filarial pathogenesis. Such information will be useful for identifying targets for the development of newer drugs for filariasis treatment, especially for preventing lymphatic pathology.}, }
@article {pmid21714941, year = {2011}, author = {Lane, N}, title = {Energetics and genetics across the prokaryote-eukaryote divide.}, journal = {Biology direct}, volume = {6}, number = {}, pages = {35}, pmid = {21714941}, issn = {1745-6150}, mesh = {Adenosine Triphosphate/metabolism ; *Biological Evolution ; Cell Cycle ; Cell Membrane/physiology ; Cell Nucleus/genetics ; Cytoplasm/genetics/physiology ; *Energy Metabolism ; Eukaryotic Cells/*cytology/physiology ; Gene Transfer, Horizontal ; Genes, Mitochondrial ; Introns ; Mitochondria/genetics/physiology ; Mutation ; Oxidative Phosphorylation ; Phylogeny ; Prokaryotic Cells/*cytology/physiology ; Selection, Genetic ; *Symbiosis ; }, abstract = {BACKGROUND: All complex life on Earth is eukaryotic. All eukaryotic cells share a common ancestor that arose just once in four billion years of evolution. Prokaryotes show no tendency to evolve greater morphological complexity, despite their metabolic virtuosity. Here I argue that the eukaryotic cell originated in a unique prokaryotic endosymbiosis, a singular event that transformed the selection pressures acting on both host and endosymbiont.<br><br>RESULTS: The reductive evolution and specialisation of endosymbionts to mitochondria resulted in an extreme genomic asymmetry, in which the residual mitochondrial genomes enabled the expansion of bioenergetic membranes over several orders of magnitude, overcoming the energetic constraints on prokaryotic genome size, and permitting the host cell genome to expand (in principle) over 200,000-fold. This energetic transformation was permissive, not prescriptive; I suggest that the actual increase in early eukaryotic genome size was driven by a heavy early bombardment of genes and introns from the endosymbiont to the host cell, producing a high mutation rate. Unlike prokaryotes, with lower mutation rates and heavy selection pressure to lose genes, early eukaryotes without genome-size limitations could mask mutations by cell fusion and genome duplication, as in allopolyploidy, giving rise to a proto-sexual cell cycle. The side effect was that a large number of shared eukaryotic basal traits accumulated in the same population, a sexual eukaryotic common ancestor, radically different to any known prokaryote.<br><br>CONCLUSIONS: The combination of massive bioenergetic expansion, release from genome-size constraints, and high mutation rate favoured a protosexual cell cycle and the accumulation of eukaryotic traits. These factors explain the unique origin of eukaryotes, the absence of true evolutionary intermediates, and the evolution of sex in eukaryotes but not prokaryotes.<br><br>REVIEWERS: This article was reviewed by: Eugene Koonin, William Martin, Ford Doolittle and Mark van der Giezen. For complete reports see the Reviewers' Comments section.}, }
@article {pmid21710568, year = {2011}, author = {Markert, S and Gardebrecht, A and Felbeck, H and Sievert, SM and Klose, J and Becher, D and Albrecht, D and Thürmer, A and Daniel, R and Kleiner, M and Hecker, M and Schweder, T}, title = {Status quo in physiological proteomics of the uncultured Riftia pachyptila endosymbiont.}, journal = {Proteomics}, volume = {11}, number = {15}, pages = {3106-3117}, doi = {10.1002/pmic.201100059}, pmid = {21710568}, issn = {1615-9861}, mesh = {Animals ; Bacteria/chemistry/metabolism ; *Bacterial Physiological Phenomena ; Bacterial Proteins/*analysis/chemistry/metabolism ; Carbon/metabolism ; Carbon Cycle/physiology ; Electrophoresis, Gel, Two-Dimensional ; Membrane Proteins/analysis/chemistry/metabolism ; Membrane Transport Proteins/analysis/chemistry/metabolism ; Metabolic Networks and Pathways ; Nitrogen/metabolism ; Polychaeta/*microbiology/*physiology ; Proteomics ; Sulfur/metabolism ; Symbiosis/*physiology ; }, abstract = {Riftia pachyptila, the giant deep-sea tube worm, inhabits hydrothermal vents in the Eastern Pacific ocean. The worms are nourished by a dense population of chemoautotrophic bacterial endosymbionts. Using the energy derived from sulfide oxidation, the symbionts fix CO(2) and produce organic carbon, which provides the nutrition of the host. Although the endosymbionts have never been cultured, cultivation-independent techniques based on density gradient centrifugation and the sequencing of their (meta-) genome enabled a detailed physiological examination on the proteomic level. In this study, the Riftia symbionts' soluble proteome map was extended to a total of 493 identified proteins, which allowed for an explicit description of vital metabolic processes such as the energy-generating sulfide oxidation pathway or the Calvin cycle, which seems to involve a reversible pyrophosphate-dependent phosphofructokinase. Furthermore, the proteomic view supports the hypothesis that the symbiont uses nitrate as an alternative electron acceptor. Finally, the membrane-associated proteome of the Riftia symbiont was selectively enriched and analyzed. As a result, 275 additional proteins were identified, most of which have putative functions in electron transfer, transport processes, secretion, signal transduction and other cell surface-related functions. Integrating this information into complex pathway models a comprehensive survey of the symbiotic physiology was established.}, }
@article {pmid21709249, year = {2011}, author = {Gruber-Vodicka, HR and Dirks, U and Leisch, N and Baranyi, C and Stoecker, K and Bulgheresi, S and Heindl, NR and Horn, M and Lott, C and Loy, A and Wagner, M and Ott, J}, title = {Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {29}, pages = {12078-12083}, pmid = {21709249}, issn = {1091-6490}, support = {P 20185/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Bayes Theorem ; *Biological Evolution ; Cluster Analysis ; DNA Primers/genetics ; In Situ Hybridization, Fluorescence ; Likelihood Functions ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhodospirillales/*genetics/ultrastructure ; Sequence Analysis, DNA ; Species Specificity ; Spectrum Analysis, Raman ; *Symbiosis ; Turbellaria/*microbiology/ultrastructure ; }, abstract = {Harnessing chemosynthetic symbionts is a recurring evolutionary strategy. Eukaryotes from six phyla as well as one archaeon have acquired chemoautotrophic sulfur-oxidizing bacteria. In contrast to this broad host diversity, known bacterial partners apparently belong to two classes of bacteria--the Gamma- and Epsilonproteobacteria. Here, we characterize the intracellular endosymbionts of the mouthless catenulid flatworm genus Paracatenula as chemoautotrophic sulfur-oxidizing Alphaproteobacteria. The symbionts of Paracatenula galateia are provisionally classified as "Candidatus Riegeria galateiae" based on 16S ribosomal RNA sequencing confirmed by fluorescence in situ hybridization together with functional gene and sulfur metabolite evidence. 16S rRNA gene phylogenetic analysis shows that all 16 Paracatenula species examined harbor host species-specific intracellular Candidatus Riegeria bacteria that form a monophyletic group within the order Rhodospirillales. Comparing host and symbiont phylogenies reveals strict cocladogenesis and points to vertical transmission of the symbionts. Between 33% and 50% of the body volume of the various worm species is composed of bacterial symbionts, by far the highest proportion among all known endosymbiotic associations between bacteria and metazoans. This symbiosis, which likely originated more than 500 Mya during the early evolution of flatworms, is the oldest known animal-chemoautotrophic bacteria association. The distant phylogenetic position of the symbionts compared with other mutualistic or parasitic Alphaproteobacteria promises to illuminate the common genetic predispositions that have allowed several members of this class to successfully colonize eukaryote cells.}, }
@article {pmid21705542, year = {2011}, author = {Ivanov, IN and Mitkova, N and Reye, AL and Hübschen, JM and Vatcheva-Dobrevska, RS and Dobreva, EG and Kantardjiev, TV and Muller, CP}, title = {Detection of new Francisella-like tick endosymbionts in Hyalomma spp. and Rhipicephalus spp. (Acari: Ixodidae) from Bulgaria.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {15}, pages = {5562-5565}, pmid = {21705542}, issn = {1098-5336}, mesh = {Animals ; Bacterial Proteins/genetics ; Base Sequence ; Bulgaria ; Francisella/*genetics/isolation &amp; purification ; Humans ; Lipoproteins/genetics ; Molecular Sequence Data ; RNA, Ribosomal, 16S/analysis/genetics ; Rhipicephalus/*microbiology ; Sequence Analysis, DNA ; Ticks/*microbiology ; }, abstract = {We report on the identification of two new Francisella-like endosymbionts (FLEs) found in three different tick species from Bulgaria. The FLEs were characterized by 16S rRNA and tul4 gene sequencing and seem to lack the molecular marker RD1. These two new taxa seem to be facultative secondary endosymbionts of ticks.}, }
@article {pmid21695260, year = {2011}, author = {Malik, SB and Brochu, CD and Bilic, I and Yuan, J and Hess, M and Logsdon, JM and Carlton, JM}, title = {Phylogeny of parasitic parabasalia and free-living relatives inferred from conventional markers vs. Rpb1, a single-copy gene.}, journal = {PloS one}, volume = {6}, number = {6}, pages = {e20774}, pmid = {21695260}, issn = {1932-6203}, support = {R21 AI083954/AI/NIAID NIH HHS/United States ; 1R21AI083954-01/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Gene Dosage/*genetics ; Genes, Protozoan/*genetics ; Genetic Markers ; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)/genetics ; Humans ; Molecular Sequence Data ; Open Reading Frames/genetics ; Parabasalidea/*genetics ; Parasites/*genetics ; *Phylogeny ; Protozoan Proteins/genetics ; RNA Polymerase II/*genetics ; }, abstract = {BACKGROUND: Parabasalia are single-celled eukaryotes (protists) that are mainly comprised of endosymbionts of termites and wood roaches, intestinal commensals, human or veterinary parasites, and free-living species. Phylogenetic comparisons of parabasalids are typically based upon morphological characters and 18S ribosomal RNA gene sequence data (rDNA), while biochemical or molecular studies of parabasalids are limited to a few axenically cultivable parasites. These previous analyses and other studies based on PCR amplification of duplicated protein-coding genes are unable to fully resolve the evolutionary relationships of parabasalids. As a result, genetic studies of Parabasalia lag behind other organisms.<br><br>PRINCIPAL FINDINGS: Comparing parabasalid EF1&#x3b1;, &#x3b1;-tubulin, enolase and MDH protein-coding genes with information from the Trichomonas vaginalis genome reveals difficulty in resolving the history of species or isolates apart from duplicated genes. A conserved single-copy gene encodes the largest subunit of RNA polymerase II (Rpb1) in T. vaginalis and other eukaryotes. Here we directly sequenced Rpb1 degenerate PCR products from 10 parabasalid genera, including several T. vaginalis isolates and avian isolates, and compared these data by phylogenetic analyses. Rpb1 genes from parabasalids, diplomonads, Parabodo, Diplonema and Percolomonas were all intronless, unlike intron-rich homologs in Naegleria, Jakoba and Malawimonas.<br><br>CONCLUSIONS/SIGNIFICANCE: The phylogeny of Rpb1 from parasitic and free-living parabasalids, and conserved Rpb1 insertions, support Trichomonadea, Tritrichomonadea, and Hypotrichomonadea as monophyletic groups. These results are consistent with prior analyses of rDNA and GAPDH sequences and ultrastructural data. The Rpb1 phylogenetic tree also resolves species- and isolate-level relationships. These findings, together with the relative ease of Rpb1 isolation, make it an attractive tool for evaluating more extensive relationships within Parabasalia.}, }
@article {pmid21684342, year = {2011}, author = {Distel, DL and Amin, M and Burgoyne, A and Linton, E and Mamangkey, G and Morrill, W and Nove, J and Wood, N and Yang, J}, title = {Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia.}, journal = {Molecular phylogenetics and evolution}, volume = {61}, number = {2}, pages = {245-254}, doi = {10.1016/j.ympev.2011.05.019}, pmid = {21684342}, issn = {1095-9513}, support = {U01 TW008163/TW/FIC NIH HHS/United States ; U19 TW008163/TW/FIC NIH HHS/United States ; 1U01TW008163/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/growth &amp; development ; Biological Evolution ; Bivalvia/*genetics/*microbiology/physiology ; Genes, rRNA ; *Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; Wood ; }, abstract = {The ability to consume wood as food (xylotrophy) is unusual among animals. In terrestrial environments, termites and other xylotrophic insects are the principle wood consumers while in marine environments wood-boring bivalves fulfill this role. However, the evolutionary origin of wood feeding in bivalves has remained largely unexplored. Here we provide data indicating that xylotrophy has arisen just once in Bivalvia in a single wood-feeding bivalve lineage that subsequently diversified into distinct shallow- and deep-water branches, both of which have been broadly successful in colonizing the world's oceans. These data also suggest that the appearance of this remarkable life habit was approximately coincident with the acquisition of bacterial endosymbionts. Here we generate a robust phylogeny for xylotrophic bivalves and related species based on sequences of small and large subunit nuclear rRNA genes. We then trace the distribution among the modern taxa of morphological characters and character states associated with xylotrophy and xylotrepesis (wood-boring) and use a parsimony-based method to infer their ancestral states. Based on these ancestral state reconstructions we propose a set of plausible hypotheses describing the evolution of symbiotic xylotrophy in Bivalvia. Within this context, we reinterpret one of the most remarkable progressions in bivalve evolution, the transformation of the "typical" myoid body plan to create a unique lineage of worm-like, tube-forming, wood-feeding clams. The well-supported phylogeny presented here is inconsistent with most taxonomic treatments for xylotrophic bivalves, indicating that the bivalve family Pholadidae and the subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic, and that the principle traits used for their taxonomic diagnosis are phylogenetically misleading.}, }
@article {pmid21674166, year = {2011}, author = {Vashishtha, A and Sharama, KK and Lakhanpaul, S}, title = {Co-existence, phylogeny and putative role of Wolbachia and yeast-like symbiont (YLS) in Kerria lacca (Kerr).}, journal = {Current microbiology}, volume = {63}, number = {2}, pages = {206-212}, pmid = {21674166}, issn = {1432-0991}, mesh = {Animals ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Fungal/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genes, rRNA ; Hemiptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Fungal/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; *Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification/*physiology ; Yeasts/classification/genetics/*isolation &amp; purification/*physiology ; }, abstract = {This study reports the first detection of Wolbachia and yeast-like symbiont (YLS) harbored in Kerria lacca (Kerr), a scale insect, latter of which produces an economically important natural resin, known as lac. Wolbachia was detected using PCR amplification and sequencing of 16S rDNA; and further confirmation and phylogenetic analysis was carried out by fast evolving wsp gene. Neighbor-joining and maximum parsimonious (MP) analysis showed that this strain belongs to subgroup "ori" of Wolbachia super group B of arthropods. Wolbachia of K. lacca is hereby designated as "wKerlac" according to Wolbachia nomenclature system. Histological study revealed the presence of yeast-like endosymbiont, which was also confirmed by PCR amplification of 18S rDNA. Phylogenetic analysis revealed that YLS of K. lacca is quite distinct from YLS of aphid, planthoppers, and beetles. Putative roles of Wolbachia in lecanoid chromosome system of sex determination and in biased sex ratio of K. lacca populations; and YLS in nutritional supplementation and detoxifying substances which are deleterious to K. lacca, are hereby, suggested.}, }
@article {pmid21668973, year = {2011}, author = {Wang, J and Wang, Y and Wang, Z and Liu, L and Zhu, XG and Ma, X}, title = {Synchronization of cytoplasmic and transferred mitochondrial ribosomal protein gene expression in land plants is linked to Telo-box motif enrichment.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {161}, pmid = {21668973}, issn = {1471-2148}, support = {HG001696/HG/NHGRI NIH HHS/United States ; }, mesh = {Base Sequence ; Biological Evolution ; Chloroplasts/*genetics ; Chromosomes, Plant ; Cytosol/metabolism ; *Gene Expression Regulation, Plant ; Genome, Plant ; Mitochondrial Proteins/*genetics ; Plant Proteins/*genetics ; Plants/*genetics ; Promoter Regions, Genetic ; Ribosomal Proteins/*genetics ; Transcription Factors/genetics ; }, abstract = {BACKGROUND: Chloroplasts and mitochondria evolved from the endosymbionts of once free-living eubacteria, and they transferred most of their genes to the host nuclear genome during evolution. The mechanisms used by plants to coordinate the expression of such transferred genes, as well as other genes in the host nuclear genome, are still poorly understood.<br><br>RESULTS: In this paper, we use nuclear-encoded chloroplast (cpRPGs), as well as mitochondrial (mtRPGs) and cytoplasmic (euRPGs) ribosomal protein genes to study the coordination of gene expression between organelles and the host. Results show that the mtRPGs, but not the cpRPGs, exhibit strongly synchronized expression with euRPGs in all investigated land plants and that this phenomenon is linked to the presence of a telo-box DNA motif in the promoter regions of mtRPGs and euRPGs. This motif is also enriched in the promoter regions of genes involved in DNA replication. Sequence analysis further indicates that mtRPGs, in contrast to cpRPGs, acquired telo-box from the host nuclear genome.<br><br>CONCLUSIONS: Based on our results, we propose a model of plant nuclear genome evolution where coordination of activities in mitochondria and chloroplast and other cellular functions, including cell cycle, might have served as a strong selection pressure for the differential acquisition of telo-box between mtRPGs and cpRPGs. This research also highlights the significance of physiological needs in shaping transcriptional regulatory evolution.}, }
@article {pmid21666073, year = {2011}, author = {Tanifuji, G and Kim, E and Onodera, NT and Gibeault, R and Dlutek, M and Cawthorn, RJ and Fiala, I and Lukes, J and Greenwood, SJ and Archibald, JM}, title = {Genomic characterization of Neoparamoeba pemaquidensis (Amoebozoa) and its kinetoplastid endosymbiont.}, journal = {Eukaryotic cell}, volume = {10}, number = {8}, pages = {1143-1146}, pmid = {21666073}, issn = {1535-9786}, support = {ROP85016//Canadian Institutes of Health Research/Canada ; }, mesh = {Amoebozoa/*genetics/microbiology ; DNA, Kinetoplast/genetics ; Genome ; Karyotype ; Kinetoplastida/*genetics/microbiology ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {We have performed a genomic characterization of a kinetoplastid protist living within the amoebozoan Neoparamoeba pemaquidensis. The genome of this "Ichthyobodo-related organism" was found to be unexpectedly large, with at least 11 chromosomes between 1.0 and 3.5 Mbp and a total genome size of at least 25 Mbp.}, }
@article {pmid21663992, year = {2011}, author = {Cordaux, R and Bouchon, D and Grève, P}, title = {The impact of endosymbionts on the evolution of host sex-determination mechanisms.}, journal = {Trends in genetics : TIG}, volume = {27}, number = {8}, pages = {332-341}, doi = {10.1016/j.tig.2011.05.002}, pmid = {21663992}, issn = {0168-9525}, mesh = {Animals ; *Biological Evolution ; Diploidy ; Female ; Fertilization ; Haploidy ; Inheritance Patterns ; Isopoda/genetics/physiology ; Male ; Parthenogenesis ; Phenotype ; Sex Chromosomes/genetics ; *Sex Determination Processes ; Sex Ratio ; *Symbiosis ; Wolbachia/genetics/pathogenicity/physiology ; }, abstract = {The past years have revealed that inherited bacterial endosymbionts are important sources of evolutionary novelty for their eukaryotic hosts. In this review we discuss a fundamental biological process of eukaryotes influenced by bacterial endosymbionts: the mechanisms of sex determination. Because they are maternally inherited, several endosymbionts of arthropods, known as reproductive parasites, have developed strategies to convert non-transmitting male hosts into transmitting females through feminization of genetic males and parthenogenesis induction. Recent investigations have also highlighted that endosymbionts can impact upon host sex determination more subtly through genetic conflicts, resulting in selection of host nuclear genes resisting endosymbiont effects. Paradoxically, it is because of their selfish nature that reproductive parasites are such powerful agents of evolutionary change in their host sex-determination mechanisms. They might therefore represent excellent models for studying transitions between sex-determining systems and, more generally, the evolution of sex-determination mechanisms in eukaryotes.}, }
@article {pmid21637826, year = {2011}, author = {Cooper, TF and Lai, M and Ulstrup, KE and Saunders, SM and Flematti, GR and Radford, B and van Oppen, MJ}, title = {Symbiodinium genotypic and environmental controls on lipids in reef building corals.}, journal = {PloS one}, volume = {6}, number = {5}, pages = {e20434}, pmid = {21637826}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*microbiology ; Australia ; *Coral Reefs ; Ecosystem ; *Environment ; Genotype ; Geography ; Lipids/*chemistry ; Microalgae/*genetics ; Models, Biological ; Symbiosis/physiology ; Water ; }, abstract = {BACKGROUND: Lipids in reef building corals can be divided into two classes; non-polar storage lipids, e.g. wax esters and triglycerides, and polar structural lipids, e.g. phospholipids and cholesterol. Differences among algal endosymbiont types are known to have important influences on processes including growth and the photobiology of scleractinian corals yet very little is known about the role of symbiont types on lipid energy reserves.<br><br>The ratio of storage lipid and structural lipid fractions of Scott Reef corals were determined by thin layer chromatography. The lipid fraction ratio varied with depth and depended on symbiont type harboured by two corals (Seriatopora hystrix and Pachyseris speciosa). S. hystrix colonies associated with Symbiodinium C1 or C1/C# at deep depths (>23 m) had lower lipid fraction ratios (i.e. approximately equal parts of storage and structural lipids) than those with Symbiodinium D1 in shallow depths (<23 m), which had higher lipid fraction ratios (i.e. approximately double amounts of storage relative to structural lipid). Further, there was a non-linear relationship between the lipid fraction ratio and depth for S. hystrix with a modal peak at &#x223c;23 m coinciding with the same depth as the shift from clade D to C types. In contrast, the proportional relationship between the lipid fraction ratio and depth for P. speciosa, which exhibited high specificity for Symbiodinium C3 like across the depth gradient, was indicative of greater amounts of storage lipids contained in the deep colonies.<br><br>CONCLUSIONS/SIGNIFICANCE: This study has demonstrated that Symbiodinium exert significant controls over the quality of coral energy reserves over a large-scale depth gradient. We conclude that the competitive advantages and metabolic costs that arise from flexible associations with divergent symbiont types are offset by energetic trade-offs for the coral host.}, }
@article {pmid21635673, year = {2011}, author = {Zurel, D and Benayahu, Y and Or, A and Kovacs, A and Gophna, U}, title = {Composition and dynamics of the gill microbiota of an invasive Indo-Pacific oyster in the eastern Mediterranean Sea.}, journal = {Environmental microbiology}, volume = {13}, number = {6}, pages = {1467-1476}, doi = {10.1111/j.1462-2920.2011.02448.x}, pmid = {21635673}, issn = {1462-2920}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Gills/*microbiology ; Introduced Species ; Mediterranean Sea ; *Metagenome ; Ostreidae/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; *Water Microbiology ; }, abstract = {Gill bacterial communities of Chama pacifica, an Indo-Pacific invasive oyster to the eastern Mediterranean Sea, were compared with those of Chama savignyi, its northern Red Sea congeneric species. Summer and winter bacterial populations were characterized and compared using 16S rDNA clone libraries, and seasonal population dynamics were monitored by automated ribosomal intergenic spacer analysis (ARISA). Clone libraries revealed a specific clade of bacteria, closely related to marine endosymbionts from the Indo-Pacific, found in both ecosystems, of which one taxon was conserved in oysters from both sites. This taxon was dominant in summer libraries and was weakly present in winter ones, where other members of this group were dominant. ARISA results revealed significant seasonal variation in bacterial populations of Mediterranean Sea oysters, as opposed to Red Sea ones that were stable throughout the year. We suggest that this conserved association between bacteria and oyster reflects either a symbiosis between the oyster host and some of its bacteria, a co-invasion of both parties, or both.}, }
@article {pmid21629728, year = {2011}, author = {Fischer, K and Beatty, WL and Jiang, D and Weil, GJ and Fischer, PU}, title = {Tissue and stage-specific distribution of Wolbachia in Brugia malayi.}, journal = {PLoS neglected tropical diseases}, volume = {5}, number = {5}, pages = {e1174}, pmid = {21629728}, issn = {1935-2735}, mesh = {Animal Structures/microbiology ; Animals ; Antibodies, Bacterial/immunology/isolation &amp; purification ; Antibodies, Monoclonal/immunology/isolation &amp; purification ; Brugia malayi/*growth &amp; development/*microbiology/physiology ; Female ; Humans ; Immunohistochemistry/methods ; In Situ Hybridization, Fluorescence/methods ; Male ; Microscopy/methods ; Parasitology/methods ; *Symbiosis ; Wolbachia/*growth &amp; development/*isolation &amp; purification/physiology ; }, abstract = {BACKGROUND: Most filarial parasite species contain Wolbachia, obligatory bacterial endosymbionts that are crucial for filarial development and reproduction. They are targets for alternative chemotherapy, but their role in the biology of filarial nematodes is not well understood. Light microscopy provides important information on morphology, localization and potential function of these bacteria. Surprisingly, immunohistology and in situ hybridization techniques have not been widely used to monitor Wolbachia distribution during the filarial life cycle.<br><br>METHODS/PRINCIPAL FINDINGS: A monoclonal antibody directed against Wolbachia surface protein and in situ hybridization targeting Wolbachia 16S rRNA were used to monitor Wolbachia during the life cycle of B. malayi. In microfilariae and vector stage larvae only a few cells contain Wolbachia. In contrast, large numbers of Wolbachia were detected in the lateral chords of L4 larvae, but no endobacteria were detected in the genital primordium. In young adult worms (5 weeks p.i.), a massive expansion of Wolbachia was observed in the lateral chords adjacent to ovaries or testis, but no endobacteria were detected in the growth zone of the ovaries, uterus, the growth zone of the testis or the vas deferens. Confocal laser scanning and transmission electron microscopy showed that numerous Wolbachia are aligned towards the developing ovaries and single endobacteria were detected in the germline. In inseminated females (8 weeks p.i.) Wolbachia were observed in the ovaries, embryos and in decreasing numbers in the lateral chords. In young males Wolbachia were found in distinct zones of the testis and in large numbers in the lateral chords in the vicinity of testicular tissue but never in mature spermatids or spermatozoa.<br><br>CONCLUSIONS: Immunohistology and in situ hybridization show distinct tissue and stage specific distribution patterns for Wolbachia in B. malayi. Extensive multiplication of Wolbachia occurs in the lateral chords of L4 and young adults adjacent to germline cells.}, }
@article {pmid21622904, year = {2011}, author = {Dorrell, RG and Smith, AG}, title = {Do red and green make brown?: perspectives on plastid acquisitions within chromalveolates.}, journal = {Eukaryotic cell}, volume = {10}, number = {7}, pages = {856-868}, pmid = {21622904}, issn = {1535-9786}, mesh = {Biological Evolution ; Chlorophyta/*genetics ; Chloroplasts/*genetics ; Genome, Chloroplast ; Phaeophyta/*genetics ; Plastids ; Rhodophyta/*genetics ; Symbiosis/genetics ; }, abstract = {The chromalveolate "supergroup" is of key interest in contemporary phycology, as it contains the overwhelming majority of extant algal species, including several phyla of key importance to oceanic net primary productivity such as diatoms, kelps, and dinoflagellates. There is also intense current interest in the exploitation of these algae for industrial purposes, such as biodiesel production. However, the evolution of the constituent species, and in particular the origin and radiation of the chloroplast genomes, remains poorly understood. In this review, we discuss current theories of the origins of the extant red alga-derived chloroplast lineages in the chromalveolates and the potential ramifications of the recent discovery of large numbers of green algal genes in chromalveolate genomes. We consider that the best explanation for this is that chromalveolates historically possessed a cryptic green algal endosymbiont that was subsequently replaced by a red algal chloroplast. We consider how changing selective pressures acting on ancient chromalveolate lineages may have selectively favored the serial endosymbioses of green and red algae and whether a complex endosymbiotic history facilitated the rise of chromalveolates to their current position of ecological prominence.}, }
@article {pmid21622788, year = {2011}, author = {Casper-Lindley, C and Kimura, S and Saxton, DS and Essaw, Y and Simpson, I and Tan, V and Sullivan, W}, title = {Rapid fluorescence-based screening for Wolbachia endosymbionts in Drosophila germ line and somatic tissues.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {14}, pages = {4788-4794}, pmid = {21622788}, issn = {1098-5336}, mesh = {Animals ; DNA, Bacterial/analysis ; Drosophila melanogaster/*microbiology ; Germ Cells/microbiology ; Microscopy, Fluorescence/*methods ; Nucleic Acids/metabolism ; Polymerase Chain Reaction ; Spiroplasma/genetics/isolation &amp; purification ; *Symbiosis ; Time Factors ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia is a globally distributed bacterial endosymbiont present in arthropods and nematodes. The advent of sensitive PCR-based approaches has greatly facilitated the identification of Wolbachia-infected individuals and analysis of population infection levels. Here, a complementary visual fluorescence-based Wolbachia screening approach is described. Through the use of the fluorescent dye Syto-11, Wolbachia can be efficiently detected in various Drosophila tissues, including ovaries. Syto-11 also stains Wolbachia in other insects. Because Wolbachia is inherited through the maternal germ line, bacteria reside in the ovaries of flies in infected populations. An advantage of this staining approach is that it informs about Wolbachia titer as well as its tissue and cellular distribution. Using this method, the infection status of insect populations in two central California locations was determined, and variants with unusually low or high Wolbachia titers were isolated. In addition, a variant with ovarioles containing both infected and uninfected egg chambers was identified. Syto-11 staining of Cardinium- and Spiroplasma-infected insects was also analyzed.}, }
@article {pmid21613430, year = {2011}, author = {Larson, MA and Fey, PD and Bartling, AM and Iwen, PC and Dempsey, MP and Francesconi, SC and Hinrichs, SH}, title = {Francisella tularensis molecular typing using differential insertion sequence amplification.}, journal = {Journal of clinical microbiology}, volume = {49}, number = {8}, pages = {2786-2797}, pmid = {21613430}, issn = {1098-660X}, mesh = {Animals ; *DNA Transposable Elements ; DNA, Bacterial/*genetics ; Electrophoresis, Gel, Pulsed-Field ; Francisella/*classification/*genetics/isolation &amp; purification ; *Genetic Variation ; Genotype ; Humans ; Molecular Typing/*methods ; Tularemia/*microbiology ; }, abstract = {Tularemia is a potentially fatal disease that is caused by the highly infectious and zoonotic pathogen Francisella tularensis. Despite the monomorphic nature of sequenced F. tularensis genomes, there is a significant degree of plasticity in the organization of genetic elements. The observed variability in these genomes is due primarily to the transposition of direct repeats and insertion sequence (IS) elements. Since current methods used to genotype F. tularensis are time-consuming and require extensive laboratory resources, IS elements were investigated as a means to subtype this organism. The unique spatial location of specific IS elements provided the basis for the development of a differential IS amplification (DISA) assay to detect and distinguish the more virulent F. tularensis subsp. tularensis (subtypes A.I and A.II) and subsp. holarctica (type B) strains from F. tularensis subsp. novicida and other near neighbors, including Francisella philomiragia and Francisella-like endosymbionts found in ticks. Amplicon sizes and sequences derived from DISA showed heterogeneity within members of the subtype A.I and A.II isolates but not the type B strains. These differences were due to a 312-bp fragment derived from the IS element ISFtu1. Analysis of wild-type F. tularensis isolates by DISA correlated with pulsed-field gel electrophoresis genotyping utilizing two different restriction endonucleases and provided rapid results with minimal sample processing. The applicability of this molecular typing assay for environmental studies was demonstrated by the accurate identification and differentiation of tick-borne F. tularensis. The described approach to IS targeting and amplification provides new capability for epidemiological investigations and characterizations of tularemia source outbreaks.}, }
@article {pmid21613060, year = {2011}, author = {Cheplick, GP}, title = {Endosymbiosis and population differentiation in wild and cultivated Lolium perenne (Poaceae).}, journal = {American journal of botany}, volume = {98}, number = {5}, pages = {829-838}, doi = {10.3732/ajb.1000226}, pmid = {21613060}, issn = {1537-2197}, mesh = {Biomass ; Endophytes/physiology ; Lolium/genetics/growth &amp; development/*microbiology/*physiology ; Neotyphodium/*physiology ; Random Allocation ; Reproduction ; *Symbiosis ; }, abstract = {PREMISE OF THE STUDY: Endophytic fungi are common inhabitants of cool-season grasses that can affect host growth and reproduction. One prerequisite for the expected coevolution between symbionts is that there exist variable effects of the endosymbiont on its host in different environments. Here, the impact of endophytes (Neotyphodium lolii) on survival, growth, and reproduction of wild populations of Lolium perenne from its native range (Italy, Morocco, Turkey, Tunisia) and two United States cultivars was explored.<br><br>METHODS: Two unmanaged, common gardens 30 m apart in New Jersey, USA, were planted with endophyte-infected and uninfected plants of the six populations in August 2008. Plants were scored for tiller number and lengths, and survival in October and December 2008 and May and September 2009; fl owering tillers (spikes) were counted in spring 2009. A greenhouse experiment was designed to assess tiller production and growth of four populations.<br><br>KEY RESULTS: There were significant effects of population and garden on tiller number and lengths but no detectable effects of endophytes. Populations from Italy and Morocco and the two US cultivars grew well in one garden, but Tunisian plants grew the least in either garden. Overwinter survival and postfl owering survival were unaffected by endophytes. Spike production was strongly influenced by population. Although populations varied, there were no differences in growth between infected and uninfected plants in the greenhouse.<br><br>CONCLUSIONS: Due to the absence of unambiguous endophyte-mediated effects on growth and reproduction of these differentiated populations, putative coevolutionary relations between the endosymbiont and its native host species remain obscure in this grass &#x2013; endophyte system.}, }
@article {pmid21612526, year = {2011}, author = {Wong, SS and Teng, JL and Poon, RW and Choi, GK and Chan, KH and Yeung, ML and Hui, JJ and Yuen, KY}, title = {Comparative evaluation of a point-of-care immunochromatographic test SNAP 4Dx with molecular detection tests for vector-borne canine pathogens in Hong Kong.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {11}, number = {9}, pages = {1269-1277}, doi = {10.1089/vbz.2010.0265}, pmid = {21612526}, issn = {1557-7759}, mesh = {Animals ; Arthropod Vectors/microbiology ; Babesia/immunology ; Chromatography, Affinity/*standards ; DNA Primers ; Databases, Nucleic Acid ; Dirofilaria immitis/immunology ; Dog Diseases/blood/*diagnosis/epidemiology/*parasitology ; Dogs ; Ehrlichia/immunology ; Hong Kong/epidemiology ; Point-of-Care Systems ; Polymerase Chain Reaction/*standards ; Reproducibility of Results ; }, abstract = {There are no comprehensive studies on the performance of commonly used point-of-care diagnostic enzyme immunoassay for common arthropod-borne canine pathogens. A comparative evaluation of an immunochromatographic test for these infections with a comprehensive polymerase chain reaction (PCR) test panel was performed on 100 pet dogs and 100 stray dogs without obvious clinical symptoms. Of the 162 positive test results from both immunochromatographic test and PCR, there was 85.2% concordance. The 24 discordant results between serology and PCR occurred in tests involving Ehrlichia canis (14) and Anaplasma platys (10), which may be related to the time of infection. No positive cases of borreliosis or rickettsiosis were detected. One important limitation of the immunochromatographic test was its lack of testing for babesiosis and hepatozoonosis. The former is the most prevalent arthropod-borne canine infection in our cohort (41%). Coinfections were found in 19% stray dogs and 6% of pet dogs with both tests (p < 0.01). Seventeen and 8 samples from stray and pet dogs, respectively, were initially positive in the PCR test for Ehrlichia. However, on sequencing of the PCR amplicon, 10 from stray and 2 from pet dogs were found to be Wolbachia sequences instead, with 100% nucleotide identity to the 16S rRNA sequence of Wolbachia endosymbiont of Dirofilaria immitis. The presence of Wolbachia DNAemia (6%) correlated well with the molecular test and immunochromatographic antigen test for D. immitis.}, }
@article {pmid21606368, year = {2011}, author = {Bennuru, S and Meng, Z and Ribeiro, JM and Semnani, RT and Ghedin, E and Chan, K and Lucas, DA and Veenstra, TD and Nutman, TB}, title = {Stage-specific proteomic expression patterns of the human filarial parasite Brugia malayi and its endosymbiont Wolbachia.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {23}, pages = {9649-9654}, pmid = {21606368}, issn = {1091-6490}, support = {HHSN261200800001C/RC/CCR NIH HHS/United States ; HHSN261200800001E/CA/NCI NIH HHS/United States ; /ImNIH/Intramural NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/*analysis/classification ; Brugia malayi/growth &amp; development/*metabolism/microbiology ; Chromatography, Liquid/methods ; Cluster Analysis ; Female ; Filariasis/parasitology ; Helminth Proteins/*analysis/classification ; Host-Pathogen Interactions ; Humans ; Larva/growth &amp; development/metabolism/microbiology ; Life Cycle Stages ; Male ; Proteome/*analysis/classification ; Proteomics/*methods ; Symbiosis ; Tandem Mass Spectrometry ; Wolbachia/*metabolism/physiology ; }, abstract = {Global proteomic analyses of pathogens have thus far been limited to unicellular organisms (e.g., protozoa and bacteria). Proteomic analyses of most eukaryotic pathogens (e.g., helminths) have been restricted to specific organs, specific stages, or secretomes. We report here a large-scale proteomic characterization of almost all the major mammalian stages of Brugia malayi, a causative agent of lymphatic filariasis, resulting in the identification of more than 62% of the products predicted from the Bm draft genome. The analysis also yielded much of the proteome of Wolbachia, the obligate endosymbiont of Bm that also expressed proteins in a stage-specific manner. Of the 11,610 predicted Bm gene products, 7,103 were definitively identified from adult male, adult female, blood-borne and uterine microfilariae, and infective L3 larvae. Among the 4,956 gene products (42.5%) inferred from the genome as "hypothetical," the present study was able to confirm 2,336 (47.1%) as bona fide proteins. Analysis of protein families and domains coupled with stage-specific expression highlight the important pathways that benefit the parasite during its development in the host. Gene set enrichment analysis identified extracellular matrix proteins and those with immunologic effects as enriched in the microfilarial and L3 stages. Parasite sex- and stage-specific protein expression identified those pathways related to parasite differentiation and demonstrates stage-specific expression by the Bm endosymbiont Wolbachia as well.}, }
@article {pmid21598659, year = {2011}, author = {Belousov, AO and Kozeretskaia, IA}, title = {[Symbiotic bacteria, which modify reproduction processes of Drosophila melanogaster].}, journal = {Mikrobiolohichnyi zhurnal (Kiev, Ukraine : 1993)}, volume = {73}, number = {2}, pages = {43-52}, pmid = {21598659}, issn = {1028-0987}, mesh = {Animals ; Bacteroidetes/*growth &amp; development ; Drosophila melanogaster/growth &amp; development/*microbiology/physiology ; Female ; Male ; Reproduction ; Spiroplasma/*growth &amp; development ; Symbiosis ; Wolbachia/*growth &amp; development ; }, abstract = {Cytoplasmic bacteria-symbionts are actively investigated all over the world for the last ten years. The scale of their spreading in natural and laboratory populations of invertebrates, especially arthropods, is impressing scientists' imagination. Ways of their intraspecific and interspecific transmission are various. The nature and mechanisms of their interaction both between themselves and with their hosts are extremely diverse. Cytoplasmic incompatibility, parthenogenesis, male-killing, feminization, tissue degeneration and others are those phenotypic effects, which intracellular bacteria can cause in their hosts. Moreover, the same bacterium can have diverse influences on different hosts. So it is possible to talk about many-sidedness of endosymbiont interaction with a host, which is determined both by bacterium and host biology. However, majority of phenotypic effects is directed to the successful colonization of hosts' populations by increasing the number of infected females. Alas, the mechanisms of interaction are still not enough investigated. Besides, intracellular bacteria-symbionts can be one of the factors of the so-called "infectious species formation". In any investigation, model organisms, Drosophila melanogaster belonging to them, take a special place. Among drosophila's endosymbionts, only bacteria from genera Wolbachia, Spiroplasma and Cardinium were broadly investigated: their spreading in Drosophila melanogaster populations all over the world, the infecting level and those phenotypic effects, which they can cause. So this review is dedicated to analysis of these studies.}, }
@article {pmid21595768, year = {2011}, author = {Dyer, KA and Burke, C and Jaenike, J}, title = {Wolbachia-mediated persistence of mtDNA from a potentially extinct species.}, journal = {Molecular ecology}, volume = {20}, number = {13}, pages = {2805-2817}, doi = {10.1111/j.1365-294X.2011.05128.x}, pmid = {21595768}, issn = {1365-294X}, mesh = {Animals ; Base Sequence ; Biological Evolution ; DNA, Mitochondrial/*genetics ; Drosophila/*genetics/microbiology ; Female ; Gene Transfer, Horizontal ; Haplotypes ; Maine ; Models, Genetic ; Molecular Sequence Data ; Multilocus Sequence Typing ; New York ; Pennsylvania ; Phylogeny ; Polymorphism, Genetic ; Sequence Analysis, DNA ; Symbiosis ; Time Factors ; Wolbachia/*genetics ; }, abstract = {Drosophila quinaria is polymorphic for infection with Wolbachia, a maternally transmitted endosymbiont. Wolbachia-infected individuals carry mtDNA that is only distantly related to the mtDNA of uninfected individuals, and the clade encompassing all mtDNA haplotypes within D. quinaria also includes the mtDNA of several other species of Drosophila. Nuclear gene variation reveals no difference between the Wolbachia-infected and uninfected individuals of D. quinaria, indicating that they all belong to the same interbreeding biological species. We suggest that the Wolbachia and the mtDNA with which it is associated were derived via interspecific hybridization and introgression. The sequences in the Wolbachia and the associated mtDNA are ≥6% divergent from those of any known Drosophila species. Thus, in spite of nearly complete species sampling, the sequences from which these mitochondria were derived remain unknown, raising the possibility that the donor species is extinct. The association between Wolbachia infection and mtDNA type within D. quinaria suggests that Wolbachia may be required for the continued persistence of the mtDNA from an otherwise extinct Drosophila species. We hypothesize that pathogen-protective effects conferred by Wolbachia operate in a negative frequency-dependent manner, thus bringing about a stable polymorphism for Wolbachia infection.}, }
@article {pmid21576469, year = {2011}, author = {Hussain, M and Frentiu, FD and Moreira, LA and O'Neill, SL and Asgari, S}, title = {Wolbachia uses host microRNAs to manipulate host gene expression and facilitate colonization of the dengue vector Aedes aegypti.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {22}, pages = {9250-9255}, pmid = {21576469}, issn = {1091-6490}, mesh = {Aedes/*metabolism ; Animals ; Dengue/*transmission ; *Gene Expression Regulation ; Gene Silencing ; Green Fluorescent Proteins/metabolism ; Insect Vectors/metabolism ; MicroRNAs/*genetics/metabolism ; Models, Biological ; RNA Interference ; Time Factors ; Virus Replication ; Wolbachia/*metabolism ; }, abstract = {The obligate endosymbiont Wolbachia pipientis is found in a wide range of invertebrates where they are best known for manipulating host reproduction. Recent studies have shown that Wolbachia also can modulate the lifespan of host insects and interfere with the development of human pathogens in mosquito vectors. Despite considerable study, very little is known about the molecular interactions between Wolbachia and its hosts that might mediate these effects. Using microarrays, we show that the microRNA (miRNA) profile of the mosquito, Aedes aegypti, is significantly altered by the wMelPop-CLA strain of W. pipientis. We found that a host miRNA (aae-miR-2940) is induced after Wolbachia infection in both mosquitoes and cell lines. One target of aae-miR-2940 is the Ae. aegypti metalloprotease gene. Interestingly, expression of the target gene was induced after Wolbachia infection, ectopic expression of the miRNA independent of Wolbachia, or transfection of an artificial mimic of the miRNA into mosquito cells. We also confirmed the interaction of aae-miR-2940 with the target sequences using GFP as a reporter gene. Silencing of the metalloprotease gene in both Wolbachia-infected cells and adult mosquitoes led to a significant reduction in Wolbachia density, as did inhibition of the miRNA in cells. These results indicate that manipulation of the mosquito metalloprotease gene via aae-miR-2940 is crucial for efficient maintenance of the endosymbiont. This report shows how Wolbachia alters the host miRNA profile and provides insight into the mechanisms of host manipulation used by this widespread endosymbiont.}, }
@article {pmid21572881, year = {2011}, author = {Rajarajan, S and Ibrahim, KS and Pandian, SK}, title = {AP-APSE dpol intein: A novel family A DNA polymerase intein domain.}, journal = {Bioinformation}, volume = {6}, number = {4}, pages = {149-152}, pmid = {21572881}, issn = {0973-2063}, abstract = {Inteins are "protein introns" that remove themselves from their host proteins through an autocatalytic protein-splicing. After their discovery, inteins have been quickly identified in organisms from all three kingdoms of life - eucarya, bacteria and archaea, but their distribution is sporadic. Here we report the identification and bioinformatics characterization of intein in DNA polymerase A gene of bacteriophage APSE (Acyrthosiphon pisum Secondary Endosymbiont bacteriophage) infecting the Aphid secondary endosymbionts of eukaryotic insects such as Acyrthosiphon pisum, Uroleucon rudbeckiae. The insertion site of intein within APSE family A DNA polymerase extein was identified to be dpola. Hence we propose this as a unique intein of family A DNA polymerase (dpola insertion site) and only reported intein in podoviridae family.}, }
@article {pmid21571878, year = {2011}, author = {Lamelas, A and Gosalbes, MJ and Moya, A and Latorre, A}, title = {New clues about the evolutionary history of metabolic losses in bacterial endosymbionts, provided by the genome of Buchnera aphidicola from the aphid Cinara tujafilina.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {13}, pages = {4446-4454}, pmid = {21571878}, issn = {1098-5336}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*genetics/isolation &amp; purification/physiology ; DNA, Bacterial/*chemistry/*genetics ; Evolution, Molecular ; *Genome, Bacterial ; Molecular Sequence Data ; Phylogeny ; *Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The symbiotic association between aphids (Homoptera) and Buchnera aphidicola (Gammaproteobacteria) started about 100 to 200 million years ago. As a consequence of this relationship, the bacterial genome has undergone a prominent size reduction. The downsize genome process starts when the bacterium enters the host and will probably end with its extinction and replacement by another healthier bacterium or with the establishment of metabolic complementation between two or more bacteria. Nowadays, several complete genomes of Buchnera aphidicola from four different aphid species (Acyrthosiphon pisum, Schizaphis graminum, Baizongia pistacea, and Cinara cedri) have been fully sequenced. C. cedri belongs to the subfamily Lachninae and harbors two coprimary bacteria that fulfill the metabolic needs of the whole consortium: B. aphidicola with the smallest genome reported so far and "Candidatus Serratia symbiotica." In addition, Cinara tujafilina, another member of the subfamily Lachninae, closely related to C. cedri, also harbors "Ca. Serratia symbiotica" but with a different phylogenetic status than the one from C. cedri. In this study, we present the complete genome sequence of B. aphidicola from C. tujafilina and the phylogenetic analysis and comparative genomics with the other Buchnera genomes. Furthermore, the gene repertoire of the last common ancestor has been inferred, and the evolutionary history of the metabolic losses that occurred in the different lineages has been analyzed. Although stochastic gene loss plays a role in the genome reduction process, it is also clear that metabolism, as a functional constraint, is also a powerful evolutionary force in insect endosymbionts.}, }
@article {pmid21569156, year = {2011}, author = {Vorburger, C and Gouskov, A}, title = {Only helpful when required: a longevity cost of harbouring defensive symbionts.}, journal = {Journal of evolutionary biology}, volume = {24}, number = {7}, pages = {1611-1617}, doi = {10.1111/j.1420-9101.2011.02292.x}, pmid = {21569156}, issn = {1420-9101}, mesh = {Animals ; Aphids/*microbiology ; Enterobacteriaceae/*physiology ; *Longevity ; *Symbiosis ; }, abstract = {Maternally transmitted symbionts can spread in host populations if they provide a fitness benefit to their hosts. Hamiltonella defensa, a bacterial endosymbiont of aphids, protects hosts against parasitoids but only occurs at moderate frequencies in most aphid populations. This suggests that harbouring this symbiont is also associated with costs, yet the nature of these costs has remained elusive. Here, we demonstrate an important and clearly defined cost: reduced longevity. Experimental infections with six different isolates of H. defensa caused strongly reduced lifespans in two different clones of the black bean aphid, Aphis fabae, resulting in a significantly lower lifetime reproduction. However, the two aphid clones were unequally affected by the presence of H. defensa, and the magnitude of the longevity cost was further determined by genotype × genotype interactions between host and symbiont, which has important consequences for their coevolution.}, }
@article {pmid21565106, year = {2010}, author = {Händeler, K and Wägele, H and Wahrmund, U and Rüdinger, M and Knoop, V}, title = {Slugs' last meals: molecular identification of sequestered chloroplasts from different algal origins in Sacoglossa (Opisthobranchia, Gastropoda).}, journal = {Molecular ecology resources}, volume = {10}, number = {6}, pages = {968-978}, doi = {10.1111/j.1755-0998.2010.02853.x}, pmid = {21565106}, issn = {1755-0998}, abstract = {Some sacoglossan sea slugs have become famous for their unique capability to extract and incorporate functional chloroplasts from algal food organisms (mainly Ulvophyceae) into their gut cells. The functional incorporation of the so-called kleptoplasts allows the slugs to rely on photosynthetic products for weeks to months, enabling them to survive long periods of food shortage over most of their life-span. The algal food spectrum providing kleptoplasts as temporary, non-inherited endosymbionts appears to vary among sacoglossan slugs, but detailed knowledge is sketchy or unavailable. Accurate identification of algal donor species, which provide the chloroplasts for long-term retention is of primary importance to elucidate the biochemical mechanisms allowing long-term functionality of the captured chloroplast in the foreign animal cell environment. Whereas some sacoglossans forage on a variety of algal species, (e.g. Elysia crispata and E. viridis) others are more selective. Hence, characterizing the range of functional sacoglossan-chloroplast associations in nature is a prerequisite to understand the basis of this enigmatic endosymbiosis. Here, we present a suitable chloroplast gene (tufA) as a marker, which allows identification of the respective algal kleptoplast donor taxa by analysing DNA from whole animals. This novel approach allows identification of donor algae on genus or even species level, thus providing evidence for the taxonomic range of food organisms. We report molecular evidence that chloroplasts from different algal sources are simultaneously incorporated in some species of Elysia. NeigborNet analyses for species assignments are preferred over tree reconstruction methods because the former allow more reliable statements on species identification via barcoding, or rather visualize alternative allocations not to be seen in the latter.}, }
@article {pmid21561747, year = {2011}, author = {Zhang, Q and Liu, G and Hu, Z}, title = {Morphological differences and molecular phylogeny of freshwater blooming species, Peridiniopsis spp. (Dinophyceae) from China.}, journal = {European journal of protistology}, volume = {47}, number = {3}, pages = {149-160}, doi = {10.1016/j.ejop.2011.03.001}, pmid = {21561747}, issn = {1618-0429}, mesh = {Animals ; China ; Diatoms/cytology/ultrastructure ; Dinoflagellida/*classification/cytology/*genetics ; Evolution, Molecular ; Fresh Water/*parasitology ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {In 2008-2010, several freshwater dinoflagellate blooms caused by Peridiniopsis spp. were observed in China. P. penardii and P. niei sampled from various geographical localities were examined by means of light and scanning electron microscopy. After comparing morphological and molecular differences, the new freshwater variety Peridiniopsis penardii var. robusta var. nov. (Peridiniales, Dinophyceae) found in Manwan Reservoir, Yunnan Province was described. The new variety differed from P. penardii since it possessed numerous robust antapical spines and a conspicuous apical spine. Molecular phylogenetic analyses based on SSU, LSU and ITS indicated P. niei, P. penardii and P. penardii var. robusta were closely related with P. kevei, and clustered into a monophyletic clade. The new variety possessed an endosymbiotic diatom which was similar to P. penardii and P. kevei, whereas the endosymbiont was not present in cells of P. niei. The endosymbiont SSU and ITS phylogenies showed that the endosymbionts of these three dinoflagellates were closely related to members of Thalassiosirales. Furthermore it was concluded that the endosymbionts might originate from Discostella-like species.}, }
@article {pmid21556168, year = {2011}, author = {Carreto, JI and Carignan, MO}, title = {Mycosporine-like amino acids: relevant secondary metabolites. Chemical and ecological aspects.}, journal = {Marine drugs}, volume = {9}, number = {3}, pages = {387-446}, pmid = {21556168}, issn = {1660-3397}, mesh = {Amino Acids/*metabolism ; Animals ; Aquatic Organisms/*metabolism ; Cyanobacteria/metabolism ; Humans ; Marine Biology ; *Ultraviolet Rays ; }, abstract = {Taxonomically diverse marine, freshwater and terrestrial organisms have evolved the capacity to synthesize, accumulate and metabolize a variety of UV-absorbing substances called mycosporine-like amino acids (MAAs) as part of an overall strategy to diminish the direct and indirect damaging effects of environmental ultraviolet radiation (UVR). Whereas the enzymatic machinery to synthesize MAAs was probably inherited from cyanobacteria ancestors via the endosymbionts hypothesis, metazoans lack this biochemical pathway, but can acquire and metabolize these compounds by trophic transference, symbiotic or bacterial association. In this review we describe the structure and physicochemical properties of MAAs, including the recently discovered compounds and the modern methods used for their isolation and identification, updating previous reviews. On this basis, we review the metabolism and distribution of this unique class of metabolites among marine organism.}, }
@article {pmid21551450, year = {2011}, author = {Eichinger, I and Klepal, W and Schmid, M and Bright, M}, title = {Organization and microanatomy of the Sclerolinum contortum trophosome (Polychaeta, Siboglinidae).}, journal = {The Biological bulletin}, volume = {220}, number = {2}, pages = {140-153}, doi = {10.1086/BBLv220n2p140}, pmid = {21551450}, issn = {1939-8697}, support = {P 20282/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animal Structures/cytology/microbiology/physiology ; Animals ; Bacteria/*growth &amp; development ; Bacterial Physiological Phenomena ; Microscopy ; Models, Biological ; Polychaeta/*cytology/*microbiology/physiology ; *Symbiosis ; }, abstract = {The trophosome-an organ especially evolved to accommodate symbiotic bacteria-is a key character of the polychaete family Siboglinidae. Astonishingly, the trophosomes vary in organization and origin between the different siboglinid taxa. The trophosome of the small genus Sclerolinum was nearly unknown until now. Here we investigated the trophosome of S. contortum from the Gulf of Mexico, using light and electron microscopy. We show that this organ derives from the visceral mesoderm and propose that the trophosome of the sister clade Vestimentifera and Sclerolinum is a homologous character. Like that of juvenile vestimentiferans, the trophosome of Sclerolinum trophosome is simply organized. This study reveals that the Sclerolinum trophosome exhibits two regions that differ in the organization of host tissue and the size and shape of the symbionts. We suggest that a specific cell cycle within the symbiont-housing organ is directed along the longitudinal body axis, with a region of proliferation anteriorly and a region of degradation posteriorly. Using Raman microspectroscopy we demonstrate that the endosymbionts of S. contortum from the Gulf of Mexico contain sulfur vesicles, and we argue for a chemoautotrophic sulfur-oxidizing metabolism.}, }
@article {pmid21548954, year = {2011}, author = {Genes, C and Baquero, E and Echeverri, F and Maya, JD and Triana, O}, title = {Mitochondrial dysfunction in Trypanosoma cruzi: the role of Serratia marcescens prodigiosin in the alternative treatment of Chagas disease.}, journal = {Parasites &amp; vectors}, volume = {4}, number = {}, pages = {66}, pmid = {21548954}, issn = {1756-3305}, mesh = {Animals ; Antiprotozoal Agents/isolation &amp; purification/*pharmacology/toxicity ; Cells, Cultured ; Chagas Disease/drug therapy ; Chlorocebus aethiops ; Epithelial Cells/drug effects ; Humans ; Lymphocytes/drug effects ; Mitochondria/*drug effects/metabolism ; Oxidative Phosphorylation/drug effects ; Prodigiosin/isolation &amp; purification/*pharmacology/toxicity ; Serratia marcescens/chemistry ; Trypanosoma cruzi/*drug effects ; }, abstract = {BACKGROUND: Chagas disease is a health threat for many people, mostly those living in Latin America. One of the most important problems in treatment is the limitation of existing drugs. Prodigiosin, produced by Serratia marcescens (Rhodnius prolixus endosymbiont), belongs to the red-pigmented bacterial prodiginine family, which displays numerous biological activities, including antibacterial, antifungal, antiprotozoal, antimalarial, immunosuppressive, and anticancer properties. Here we describe its effects on Trypanosoma cruzi mitochondria belonging to Tc I and Tc II.<br><br>RESULTS: Parasites exposed to prodigiosin altered the mitochondrial function and oxidative phosphorylation could not have a normal course, probably by inhibition of complex III. Prodigiosin did not produce cytotoxic effects in lymphocytes and Vero cells and has better effects than benznidazole. Our data suggest that the action of prodigiosin on the parasites is mediated by mitochondrial structural and functional disruptions that could lead the parasites to an apoptotic-like cell death process.<br><br>CONCLUSIONS: Here, we propose a potentially useful trypanocidal agent derived from knowledge of an important aspect of the natural life cycle of the parasite: the vector-parasite interaction. Our results indicate that prodigiosin could be a good candidate for the treatment of Chagas disease.}, }
@article {pmid21541357, year = {2011}, author = {Hancock, PA and Sinkins, SP and Godfray, HC}, title = {Strategies for introducing Wolbachia to reduce transmission of mosquito-borne diseases.}, journal = {PLoS neglected tropical diseases}, volume = {5}, number = {4}, pages = {e1024}, pmid = {21541357}, issn = {1935-2735}, support = {079059/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Culicidae/*microbiology ; Female ; Insect Control/*methods ; Male ; Models, Statistical ; Pest Control, Biological/*methods ; Wolbachia/*pathogenicity ; }, abstract = {Certain strains of the endosymbiont Wolbachia have the potential to lower the vectorial capacity of mosquito populations and assist in controlling a number of mosquito-borne diseases. An important consideration when introducing Wolbachia-carrying mosquitoes into natural populations is the minimisation of any transient increase in disease risk or biting nuisance. This may be achieved by predominantly releasing male mosquitoes. To explore this, we use a sex-structured model of Wolbachia-mosquito interactions. We first show that Wolbachia spread can be initiated with very few infected females provided the infection frequency in males exceeds a threshold. We then consider realistic introduction scenarios involving the release of batches of infected mosquitoes, incorporating seasonal fluctuations in population size. For a range of assumptions about mosquito population dynamics we find that male-biased releases allow the infection to spread after the introduction of low numbers of females, many fewer than with equal sex-ratio releases. We extend the model to estimate the transmission rate of a mosquito-borne pathogen over the course of Wolbachia establishment. For a range of release strategies we demonstrate that male-biased release of Wolbachia-infected mosquitoes can cause substantial transmission reductions without transiently increasing disease risk. The results show the importance of including mosquito population dynamics in studying Wolbachia spread and that male-biased releases can be an effective and safe way of rapidly establishing the symbiont in mosquito populations.}, }
@article {pmid21539752, year = {2011}, author = {Lackner, G and Moebius, N and Partida-Martinez, LP and Boland, S and Hertweck, C}, title = {Evolution of an endofungal lifestyle: Deductions from the Burkholderia rhizoxinica genome.}, journal = {BMC genomics}, volume = {12}, number = {}, pages = {210}, pmid = {21539752}, issn = {1471-2164}, mesh = {Anti-Bacterial Agents/pharmacology ; Bacterial Proteins/genetics/metabolism ; Biological Transport ; Burkholderia/drug effects/*genetics/metabolism/*physiology ; Drug Resistance, Bacterial/genetics ; Drug Resistance, Multiple/genetics ; *Evolution, Molecular ; Fimbriae, Bacterial/genetics/metabolism ; Genome, Bacterial/genetics ; Genomics/*methods ; Lipopolysaccharides/metabolism ; Pseudogenes/genetics ; *Rhizopus/metabolism ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: Burkholderia rhizoxinica is an intracellular symbiont of the phytopathogenic zygomycete Rhizopus microsporus, the causative agent of rice seedling blight. The endosymbiont produces the antimitotic macrolide rhizoxin for its host. It is vertically transmitted within vegetative spores and is essential for spore formation of the fungus. To shed light on the evolution and genetic potential of this model organism, we analysed the whole genome of B. rhizoxinica HKI 0454 - a type strain of endofungal Burkholderia species.<br><br>RESULTS: The genome consists of a structurally conserved chromosome and two plasmids. Compared to free-living Burkholderia species, the genome is smaller in size and harbors less transcriptional regulator genes. Instead, we observed accumulation of transposons over the genome. Prediction of primary metabolic pathways and transporters suggests that endosymbionts consume host metabolites like citrate, but might deliver some amino acids and cofactors to the host. The rhizoxin biosynthesis gene cluster shows evolutionary traces of horizontal gene transfer. Furthermore, we analysed gene clusters coding for nonribosomal peptide synthetases (NRPS). Notably, B. rhizoxinica lacks common genes which are dedicated to quorum sensing systems, but is equipped with a large number of virulence-related factors and putative type III effectors.<br><br>CONCLUSIONS: B. rhizoxinica is the first endofungal bacterium, whose genome has been sequenced. Here, we present models of evolution, metabolism and tools for host-symbiont interaction of the endofungal bacterium deduced from whole genome analyses. Genome size and structure suggest that B. rhizoxinica is in an early phase of adaptation to the intracellular lifestyle (genome in transition). By analysis of tranporters and metabolic pathways we predict how metabolites might be exchanged between the symbiont and its host. Gene clusters for biosynthesis of secondary metabolites represent novel targets for genomic mining of cryptic natural products. In silico analyses of virulence-associated genes, secreted proteins and effectors might inspire future studies on molecular mechanisms underlying bacterial-fungal interaction.}, }
@article {pmid21536480, year = {2011}, author = {Reinhold-Hurek, B and Hurek, T}, title = {Living inside plants: bacterial endophytes.}, journal = {Current opinion in plant biology}, volume = {14}, number = {4}, pages = {435-443}, doi = {10.1016/j.pbi.2011.04.004}, pmid = {21536480}, issn = {1879-0356}, mesh = {Bacteria/genetics/*growth &amp; development/immunology ; Endophytes/genetics/*growth &amp; development/immunology ; Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; Plant Immunity ; Plant Roots/*microbiology ; Plants/*microbiology ; Signal Transduction ; }, abstract = {As current research activities have focused on symbiotic or parasitic plant-microbe interactions, other types of associations between plants and microorganisms are often overlooked. Endophytic bacteria colonize inner host tissues, sometimes in high numbers, without damaging the host or eliciting strong defense responses. Unlike endosymbionts they are not residing in living plant cells or surrounded by a membrane compartment. The molecular basis of endophytic interactions is still not well understood. Several traits involved in the establishment of endophytes have been elucidated. Culture-independent methods for community analysis and functional genomic as well as comparative genomic analyses will provide a better understanding of community dynamics, signaling, and functions in endophyte-plant associations.}, }
@article {pmid21527340, year = {2011}, author = {Lemaire, B and Smets, E and Dessein, S}, title = {Bacterial leaf symbiosis in Ardisia (Myrsinoideae, Primulaceae): molecular evidence for host specificity.}, journal = {Research in microbiology}, volume = {162}, number = {5}, pages = {528-534}, doi = {10.1016/j.resmic.2011.04.003}, pmid = {21527340}, issn = {1769-7123}, mesh = {Ardisia/*microbiology/physiology ; Burkholderia/classification/genetics/*isolation &amp; purification ; *Host Specificity ; Molecular Sequence Data ; Phylogeny ; Plant Leaves/microbiology/physiology ; Primulaceae/microbiology/physiology ; *Symbiosis ; }, abstract = {The association between bacteria and leaves in Ardisia has been described as a cyclic and obligate symbiosis in which bacteria are maintained throughout all stages of the plant's life cycle to guarantee normal growth and survival of the host. This intimate interaction suggests that both partners have co-diversified together. To test this co-speciation hypothesis, we constructed an endosymbiont (16S rDNA and gyrB) and host (rps16, trnL, matK and ITS) phylogeny. Phylogenetic analyses of the endosymbionts revealed a pattern of strict host specificity and recovered a single clade in the genus Burkholderia (β-proteobacteria), which was closely related to the endosymbionts of leaf-nodulated Rubiaceae. Comparison of symbiont and host phylogenies suggests a single origin of bacterial leaf symbiosis in the nodulated ancestor of Ardisia and does not reject the co-speciation hypothesis.}, }
@article {pmid21521697, year = {2011}, author = {Matsushima, R and Tang, LY and Zhang, L and Yamada, H and Twell, D and Sakamoto, W}, title = {A conserved, Mg[2]+-dependent exonuclease degrades organelle DNA during Arabidopsis pollen development.}, journal = {The Plant cell}, volume = {23}, number = {4}, pages = {1608-1624}, pmid = {21521697}, issn = {1532-298X}, mesh = {Arabidopsis/cytology/*enzymology/growth &amp; development/ultrastructure ; Arabidopsis Proteins/genetics/*metabolism ; Chromosome Mapping ; Cloning, Molecular ; Conserved Sequence/genetics ; DNA, Chloroplast/metabolism ; DNA, Mitochondrial/metabolism ; DNA, Plant/*metabolism ; Exonucleases/*metabolism ; Exoribonucleases/genetics/*metabolism ; Genes, Plant/genetics ; Genetic Complementation Test ; Germination ; Inheritance Patterns/genetics ; Magnesium/*metabolism ; Mesophyll Cells/cytology/metabolism ; Mitochondria/metabolism ; Mutant Proteins/isolation &amp; purification ; Mutation/genetics ; Organ Specificity ; Organelles/*genetics ; Phenotype ; Plastids/metabolism ; Pollen/cytology/*growth &amp; development/metabolism/ultrastructure ; Protein Transport ; Recombinant Fusion Proteins/metabolism ; Reproduction ; }, abstract = {In plant cells, mitochondria and plastids contain their own genomes derived from the ancestral bacteria endosymbiont. Despite their limited genetic capacity, these multicopy organelle genomes account for a substantial fraction of total cellular DNA, raising the question of whether organelle DNA quantity is controlled spatially or temporally. In this study, we genetically dissected the organelle DNA decrease in pollen, a phenomenon that appears to be common in most angiosperm species. By staining mature pollen grains with fluorescent DNA dye, we screened Arabidopsis thaliana for mutants in which extrachromosomal DNAs had accumulated. Such a recessive mutant, termed defective in pollen organelle DNA degradation1 (dpd1), showing elevated levels of DNAs in both plastids and mitochondria, was isolated and characterized. DPD1 encodes a protein belonging to the exonuclease family, whose homologs appear to be found in angiosperms. Indeed, DPD1 has Mg[2+]-dependent exonuclease activity when expressed as a fusion protein and when assayed in vitro and is highly active in developing pollen. Consistent with the dpd phenotype, DPD1 is dual-targeted to plastids and mitochondria. Therefore, we provide evidence of active organelle DNA degradation in the angiosperm male gametophyte, primarily independent of maternal inheritance; the biological function of organellar DNA degradation in pollen is currently unclear.}, }
@article {pmid21520999, year = {2011}, author = {Zhang, N and Zhang, S and Borchert, S and Richardson, K and Schmid, J}, title = {High levels of a fungal superoxide dismutase and increased concentration of a PR-10 plant protein in associations between the endophytic fungus Neotyphodium lolii and ryegrass.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {24}, number = {8}, pages = {984-992}, doi = {10.1094/MPMI-02-11-0028}, pmid = {21520999}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Fungal Proteins/genetics/*metabolism ; Gene Expression Profiling ; Gene Expression Regulation, Enzymologic/physiology ; Gene Expression Regulation, Fungal/physiology ; Gene Expression Regulation, Plant/*physiology ; Lolium/*microbiology ; Molecular Sequence Data ; Neotyphodium/enzymology/*physiology ; Plant Proteins/*metabolism ; Proteomics ; Superoxide Dismutase/genetics/*metabolism ; Symbiosis ; }, abstract = {Neotyphodium lolii is a fungal endosymbiont of the ryegrass Lolium perenne. Its growth is tightly controlled and synchronized with that of the plant. How the symbionts communicate is largely unknown but failure of the endophyte to elicit a defense response is considered crucial for successful symbiosis. In silver-stained two-dimensional gels of protein extracts from endophyte-infected ryegrass, a fungal Cu/Zn superoxide dismutase was detectable, even though the fungus accounts for only <[1]/500 of the biomass, indicating that it is an abundant fungal protein and that the fungus needs protection against reactive oxygen species. The plant increased levels of a pathogenesis-related class 10 (PR-10) protein; when equal amounts of protein from infected and uninfected plants were loaded, PR-10 was only detectable in extracts from infected plants. Presence of the endophyte did not lead to a significant increase in PR10 transcript levels. In protein extracts from a symbiosis containing an N. lolii variant with an abnormal in planta growth pattern, the fungal Cu/Zn superoxide dismutase but not PR-10 protein was detectable. The correlation between increased PR-10 levels and presence of a normally growing endophyte is suggestive of a role of a very limited host defense in the interaction between grass and endophyte.}, }
@article {pmid21518391, year = {2011}, author = {Löffelhardt, W}, title = {The chlorarachniophyte nucleomorph is supplemented with host cell nucleus-encoded histones.}, journal = {Molecular microbiology}, volume = {80}, number = {6}, pages = {1413-1416}, doi = {10.1111/j.1365-2958.2011.07671.x}, pmid = {21518391}, issn = {1365-2958}, mesh = {Cell Nucleus/*metabolism ; Cercozoa/*physiology ; Chlorophyta/*physiology ; Histones/*metabolism ; Protozoan Proteins/*metabolism ; *Symbiosis ; }, abstract = {In chlorarachniophytes, algae originating from secondary endosymbiosis, the complex plastids retained a nucleomorph, the vestigial nucleus of the green algal endosymbiont. The nucleomorph of Bigelowiella natans encodes several plastid-targeted proteins and hundreds of housekeeping proteins. However, many fundamental genes for the maintainance of this subcompartment are missing. In this issue of Molecular Microbiology, Hirakawa et al. (2011) demonstrate nuclear histone genes of dual evolutionary origin in B. natans and convincingly show the targeting of the corresponding proteins to nucleus and nucleomorph respectively. One of the ways through which the nuclear genome exerts control upon its endosymbiotic junior partner is revealed. Insights into the nature of bipartite targeting sequences directing the respective proteins into the periplastidal space (where the nucleomorph resides) are gained. Further, cell cycle-dependent, differential regulation is shown for both nuclear and nucleomorph histone genes.}, }
@article {pmid21518077, year = {2011}, author = {Johnson, MD}, title = {Acquired phototrophy in ciliates: a review of cellular interactions and structural adaptations.}, journal = {The Journal of eukaryotic microbiology}, volume = {58}, number = {3}, pages = {185-195}, doi = {10.1111/j.1550-7408.2011.00545.x}, pmid = {21518077}, issn = {1550-7408}, mesh = {Ciliophora/metabolism/*physiology ; Microbial Interactions ; Phagocytosis ; *Phototrophic Processes ; Plastids/metabolism ; Symbiosis ; }, abstract = {Many ciliates acquire the capacity for photosynthesis through stealing plastids or harboring intact endosymbiotic algae. Both phenomena are a form of mixotrophy and are widespread among ciliates. Mixotrophic ciliates may be abundant in freshwater and marine ecosystems, sometimes making substantial contributions toward community primary productivity. While mixotrophic ciliates utilize phagotrophy to capture algal cells, their endomembrane system has evolved to partially bypass typical heterotrophic digestion pathways, enabling metabolic interaction with foreign cells or organelles. Unique adaptations may also be found in certain algal endosymbionts, facilitating establishment of symbiosis and nutritional interactions, while reducing their fitness for survival as free-living cells. Plastid retaining oligotrich ciliates possess little selectivity from which algae they sequester plastids, resulting in unstable kleptoplastids that require frequent ingestion of algal cells to replace them. Mesodinium rubrum (=Myrionecta rubra) possesses cryptophyte organelles that resemble a reduced endosymbont, and is the only ciliate capable of functional phototrophy and plastid division. Certain strains of M. rubrum may have a stable association with their cryptophyte organelles, while others need to acquire a cryptophyte nucleus through feeding. This process of stealing a nucleus, termed karyoklepty, was first described in M. rubrum and may be an evolutionary precursor to a stable, reduced endosymbiont, and perhaps eventually a tertiary plastid. The newly described Mesodinium"chamaeleon," however, is less selective of which cryptophyte species it will retain organelles, and appears less capable of sustained phototrophy. Ciliates likely stem from a phototrophic ancestry, which may explain their propensity to practice acquired phototrophy.}, }
@article {pmid21515811, year = {2011}, author = {Atyame, CM and Delsuc, F and Pasteur, N and Weill, M and Duron, O}, title = {Diversification of Wolbachia endosymbiont in the Culex pipiens mosquito.}, journal = {Molecular biology and evolution}, volume = {28}, number = {10}, pages = {2761-2772}, doi = {10.1093/molbev/msr083}, pmid = {21515811}, issn = {1537-1719}, mesh = {Animals ; Cluster Analysis ; Culex/genetics/*microbiology ; DNA, Mitochondrial/genetics ; Gene Rearrangement ; Genetic Markers ; Phylogeny ; Phylogeography ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {The α-proteobacteria Wolbachia are among the most common intracellular bacteria and have recently emerged as important drivers of arthropod biology. Wolbachia commonly act as reproductive parasites in arthropods by inducing cytoplasmic incompatibility (CI), a type of conditional sterility between hosts harboring incompatible infections. In this study, we examined the evolutionary histories of Wolbachia infections, known as wPip, in the common house mosquito Culex pipiens, which exhibits the greatest variation in CI crossing patterns observed in any insect. We first investigated a panel of 20 wPip strains for their genetic diversity through a multilocus scheme combining 13 Wolbachia genes. Because Wolbachia depend primarily on maternal transmission for spreading within arthropod populations, we also studied the variability in the coinherited Cx. pipiens mitochondria. In total, we identified 14 wPip haplotypes, which all share a monophyletic origin and clearly cluster into five distinct wPip groups. The diversity of Cx. pipiens mitochondria was extremely reduced, which is likely a consequence of cytoplasmic hitchhiking driven by a unique and recent Wolbachia invasion. Phylogenetic evidence indicates that wPip infections and mitochondrial DNA have codiverged through stable cotransmission within the cytoplasm and shows that a rapid diversification of wPip has occurred. The observed pattern demonstrates that a considerable degree of Wolbachia diversity can evolve within a single host species over short evolutionary periods. In addition, multiple signatures of recombination were found in most wPip genomic regions, leading us to conclude that the mosaic nature of wPip genomes may play a key role in their evolution.}, }
@article {pmid21506842, year = {2011}, author = {Ogino, K and Tsuneki, K and Furuya, H}, title = {Distinction of cell types in Dicyema japonicum (phylum Dicyemida) by expression patterns of 16 genes.}, journal = {The Journal of parasitology}, volume = {97}, number = {4}, pages = {596-601}, doi = {10.1645/GE-2472.1}, pmid = {21506842}, issn = {1937-2345}, mesh = {Animals ; Cell Differentiation/genetics ; Cephalopoda/*parasitology ; DNA, Complementary/biosynthesis/chemistry/genetics ; *Gene Expression ; Gene Expression Profiling ; In Situ Hybridization ; Invertebrates/*cytology/*genetics/physiology ; Larva/cytology/genetics ; Life Cycle Stages ; Molecular Sequence Data ; RNA/genetics ; RNA Probes ; Symbiosis ; }, abstract = {Dicyemids (phylum Dicyemida) are endoparasites, or endosymbionts, typically found in the renal sac of benthic cephalopod molluscs. The body organization of dicyemids is very simple, consisting of only 9 to 41 somatic cells. Dicyemids appear to have no differentiated tissues. Although categorization of somatic cells, to some types, is based on differences in the pattern of cilia and their position in the body, whether or not these cells are functionally different remains to be revealed. To provide insight into the functional differentiation, we performed whole mount in situ hybridization (WISH) to detect expression patterns of 16 genes, i.e., aquaglyceroporin, F-actin capping protein, aspartate aminotransferase, cathepsin-L-like cysteine peptidase, Ets domain-containing protein, glucose transporter, glucose-6-phosphate 1-dehydrogenase, glycine transporter, Hsp 70, Hsp 90, isocitrate dehydrogenase subunit alpha, Rad18, serine hydroxymethyltransferase, succinate-CoA ligase, valosin-containing protein, and 14-3-3 protein. In certain genes, regional specific expression patterns were observed among somatic cells of vermiform stages and infusoriform larvae of dicyemids. The WISH analyses also revealed that the Ets domain-containing protein and Rad18 are molecular markers for agametes.}, }
@article {pmid21502821, year = {2011}, author = {Feddermann, N and Reinhardt, D}, title = {Conserved residues in the ankyrin domain of VAPYRIN indicate potential protein-protein interaction surfaces.}, journal = {Plant signaling &amp; behavior}, volume = {6}, number = {5}, pages = {680-684}, pmid = {21502821}, issn = {1559-2324}, mesh = {Amino Acid Sequence ; Ankyrins/*chemistry ; Binding Sites ; Conserved Sequence/*genetics ; Humans ; Molecular Sequence Data ; Plant Proteins/*chemistry/metabolism ; Plants/metabolism ; *Protein Interaction Mapping ; Protein Structure, Tertiary ; }, abstract = {Plant VAPYRINS are required for the establishment of arbuscular mycorrhiza (AM) and root nodule symbiosis (RNS). In vapyrin mutants, the intracellular accommodation of AM fungi and rhizobia is blocked, and in the case of AM, the fungal endosymbiont cannot develop arbuscules which serve for nutrient exchange. VAPYRINs are plant-specific proteins that consists of a major sperm protein (MSP) domain and an ankyrin domain. Comparison of VAPYRINS of dicots, monocots, and the moss Physcomitrella patens reveals a highly conserved domain structure. We focused our attention on the ankyrin domain, which closely resembles the D34 domain of human ankyrin R. Conserved residues within the petunia VAPYRIN cluster to a surface patch on the concave side of the crescent-shaped ankyrin domain, suggesting that this region may represent a conserved binding site involved in the formation of a protein complex with an essential function in intracellular accommodation of microbial endosymbionts.}, }
@article {pmid21501489, year = {2011}, author = {Maruyama, S and Suzaki, T and Weber, AP and Archibald, JM and Nozaki, H}, title = {Eukaryote-to-eukaryote gene transfer gives rise to genome mosaicism in euglenids.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {105}, pmid = {21501489}, issn = {1471-2148}, mesh = {Chlorophyta/*genetics/physiology ; Euglenida/classification/*genetics/physiology ; *Gene Transfer, Horizontal ; *Genome ; Molecular Sequence Data ; *Mosaicism ; Phylogeny ; Plastids/genetics ; Rhodophyta/*genetics/physiology ; Symbiosis ; }, abstract = {BACKGROUND: Euglenophytes are a group of photosynthetic flagellates possessing a plastid derived from a green algal endosymbiont, which was incorporated into an ancestral host cell via secondary endosymbiosis. However, the impact of endosymbiosis on the euglenophyte nuclear genome is not fully understood due to its complex nature as a 'hybrid' of a non-photosynthetic host cell and a secondary endosymbiont.<br><br>RESULTS: We analyzed an EST dataset of the model euglenophyte Euglena gracilis using a gene mining program designed to detect laterally transferred genes. We found E. gracilis genes showing affinity not only with green algae, from which the secondary plastid in euglenophytes evolved, but also red algae and/or secondary algae containing red algal-derived plastids. Phylogenetic analyses of these 'red lineage' genes suggest that E. gracilis acquired at least 14 genes via eukaryote-to-eukaryote lateral gene transfer from algal sources other than the green algal endosymbiont that gave rise to its current plastid. We constructed an EST library of the aplastidic euglenid Peranema trichophorum, which is a eukaryovorous relative of euglenophytes, and also identified 'red lineage' genes in its genome.<br><br>CONCLUSIONS: Our data show genome mosaicism in E. gracilis and P. trichophorum. One possible explanation for the presence of these genes in these organisms is that some or all of them were independently acquired by lateral gene transfer and contributed to the successful integration and functioning of the green algal endosymbiont as a secondary plastid. Alternative hypotheses include the presence of a phagocytosed alga as the single source of those genes, or a cryptic tertiary endosymbiont harboring secondary plastid of red algal origin, which the eukaryovorous ancestor of euglenophytes had acquired prior to the secondary endosymbiosis of a green alga.}, }
@article {pmid21501464, year = {2011}, author = {Tijsse-Klasen, E and Fonville, M and Gassner, F and Nijhof, AM and Hovius, EK and Jongejan, F and Takken, W and Reimerink, JR and Overgaauw, PA and Sprong, H}, title = {Absence of zoonotic Bartonella species in questing ticks: first detection of Bartonella clarridgeiae and Rickettsia felis in cat fleas in the Netherlands.}, journal = {Parasites &amp; vectors}, volume = {4}, number = {}, pages = {61}, pmid = {21501464}, issn = {1756-3305}, mesh = {Animals ; Bacterial Proteins/genetics ; Bartonellaceae/classification/genetics/*isolation &amp; purification ; Cats ; Deer ; Ixodes/*microbiology ; Netherlands ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rickettsieae/classification/genetics/*isolation &amp; purification ; Siphonaptera/*microbiology ; }, abstract = {BACKGROUND: Awareness for flea- and tick-borne infections has grown in recent years and the range of microorganisms associated with these ectoparasites is rising. Bartonella henselae, the causative agent of Cat Scratch Disease, and other Bartonella species have been reported in fleas and ticks. The role of Ixodes ricinus ticks in the natural cycle of Bartonella spp. and the transmission of these bacteria to humans is unclear. Rickettsia spp. have also been reported from as well ticks as also from fleas. However, to date no flea-borne Rickettsia spp. were reported from the Netherlands. Here, the presence of Bartonellaceae and Rickettsiae in ectoparasites was investigated using molecular detection and identification on part of the gltA- and 16S rRNA-genes.<br><br>RESULTS: The zoonotic Bartonella clarridgeiae and Rickettsia felis were detected for the first time in Dutch cat fleas. B. henselae was found in cat fleas and B. schoenbuchensis in ticks and keds feeding on deer. Two Bartonella species, previously identified in rodents, were found in wild mice and their fleas. However, none of these microorganisms were found in 1719 questing Ixodes ricinus ticks. Notably, the gltA gene amplified from DNA lysates of approximately 10% of the questing nymph and adult ticks was similar to that of an uncultured Bartonella-related species found in other hard tick species. The gltA gene of this Bartonella-related species was also detected in questing larvae for which a 16S rRNA gene PCR also tested positive for "Candidatus Midichloria mitochondrii". The gltA-gene of the Bartonella-related species found in I. ricinus may therefore be from this endosymbiont.<br><br>CONCLUSIONS: We conclude that the risk of acquiring Cat Scratch Disease or a related bartonellosis from questing ticks in the Netherlands is negligible. On the other hand fleas and deer keds are probable vectors for associated Bartonella species between animals and might also transmit Bartonella spp. to humans.}, }
@article {pmid21498883, year = {2011}, author = {Moog, D and Stork, S and Zauner, S and Maier, UG}, title = {In silico and in vivo investigations of proteins of a minimized eukaryotic cytoplasm.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {375-382}, pmid = {21498883}, issn = {1759-6653}, mesh = {Cytoplasm/chemistry/genetics/*metabolism ; Diatoms/chemistry/*cytology/genetics/*metabolism ; Plastids/chemistry/genetics/*metabolism ; Protein Sorting Signals ; Protein Transport ; }, abstract = {Algae with secondary plastids such as diatoms maintain two different eukaryotic cytoplasms. One of them, the so-called periplastidal compartment (PPC), is the naturally minimized cytoplasm of a eukaryotic endosymbiont. In order to investigate the protein composition of the PPC of diatoms, we applied knowledge of the targeting signals of PPC-directed proteins in searches of the genome data for proteins acting in the PPC and proved their in vivo localization via expressing green fluorescent protein (GFP) fusions. Our investigation increased the knowledge of the protein content of the PPC approximately 3-fold and thereby indicated that this narrow compartment was functionally reduced to some important cellular functions with nearly no housekeeping biochemical pathways.}, }
@article {pmid21484295, year = {2011}, author = {Sobrero, P and Valverde, C}, title = {Evidences of autoregulation of hfq expression in Sinorhizobium meliloti strain 2011.}, journal = {Archives of microbiology}, volume = {193}, number = {9}, pages = {629-639}, doi = {10.1007/s00203-011-0701-1}, pmid = {21484295}, issn = {1432-072X}, mesh = {Amino Acid Sequence ; Base Sequence ; Escherichia coli/genetics/metabolism ; Escherichia coli Proteins/chemistry ; *Gene Expression Regulation, Bacterial ; Homeostasis ; Host Factor 1 Protein/chemistry/*genetics/metabolism ; Molecular Sequence Data ; Sinorhizobium meliloti/*genetics/metabolism ; }, abstract = {Riboregulation comprises gene expression regulatory mechanisms that rely upon the activity of small non-coding RNAs (sRNAs) and in most cases RNA binding proteins. In γ-proteobacteria, the Sm-like protein Hfq is a key player in riboregulatory processes, because it promotes sRNA-mRNA interactions and influences mRNA polyadenylation or translation. In the α-proteobacterium Sinorhizobium meliloti, the large number of detected small RNA transcripts and the pleiotropic effects of hfq mutations lead to the hypothesis that riboregulatory mechanisms are important in this soil microorganism to adjust gene expression both in free-living conditions and as a nitrogen-fixing endosymbiont within legume root nodules. In this study, homology modeling of S. meliloti Hfq protein and cross-complementation experiments of S. meliloti and Escherichia coli mutants indicates that hfq (Sm) encodes an RNA chaperone that can be functionally exchanged by its homolog from E. coli. A transcriptional and translational analysis of S. meliloti hfq expression by means of lacZ reporter fusions strongly suggests that the S. meliloti Hfq protein autocontrols its expression at the translational level, a phenomenon that was evident in the natural host S. meliloti as well as in the heterologous host E. coli.}, }
@article {pmid21479261, year = {2011}, author = {Obata, H and Manabe, A and Nakamura, N and Onishi, T and Senba, Y}, title = {A new light on the evolution and propagation of prehistoric grain pests: the world's oldest maize weevils found in Jomon Potteries, Japan.}, journal = {PloS one}, volume = {6}, number = {3}, pages = {e14785}, pmid = {21479261}, issn = {1932-6203}, mesh = {Agriculture ; Animals ; *Biological Evolution ; *Fossils ; Japan ; Life Cycle Stages ; Models, Biological ; Oryza/growth &amp; development ; Seeds/*parasitology ; Species Specificity ; Time Factors ; Tomography, X-Ray Computed ; Weevils/*growth &amp; development/ultrastructure ; Zea mays/*parasitology ; }, abstract = {Three Sitophilus species (S. granarius L., S. oryzae L., and S. zeamais Mots.) are closely related based on DNA analysis of their endosymbionts. All are seed parasites of cereal crops and important economic pest species in stored grain. The Sitophilus species that currently exist, including these three species, are generally believed to be endemic to Asia's forested areas, suggesting that the first infestations of stored grain must have taken place near the forested mountains of southwestern Asia. Previous archaeological data and historical records suggest that the three species may have been diffused by the spread of Neolithic agriculture, but this hypothesis has only been established for granary weevils in European and southwestern Asian archaeological records. There was little archeological evidence for grain pests in East Asia before the discovery of maize weevil impressions in Jomon pottery in 2004 using the "impression replica" method. Our research on Jomon agriculture based on seed and insect impressions in pottery continued to seek additional evidence. In 2010, we discovered older weevil impressions in Jomon pottery dating to ca. 10 500 BP. These specimens are the oldest harmful insects in the world discovered at archaeological sites. Our results provide evidence of harmful insects living in the villages from the Earliest Jomon, when no cereals were cultivated. This suggests we must reconsider previous scenarios for the evolution and propagation of grain pest weevils, especially in eastern Asia. Although details of their biology or the foods they infested remain unclear, we hope future interdisciplinary collaborations among geneticists, entomologists, and archaeologists will provide the missing details.}, }
@article {pmid21470316, year = {2011}, author = {Hirakawa, Y and Burki, F and Keeling, PJ}, title = {Nucleus- and nucleomorph-targeted histone proteins in a chlorarachniophyte alga.}, journal = {Molecular microbiology}, volume = {80}, number = {6}, pages = {1439-1449}, doi = {10.1111/j.1365-2958.2011.07643.x}, pmid = {21470316}, issn = {1365-2958}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Amino Acid Sequence ; Cell Nucleus/chemistry/genetics/*metabolism ; Cercozoa/chemistry/classification/genetics/*physiology ; Chlorophyta/genetics/*physiology ; Histones/chemistry/genetics/*metabolism ; Molecular Sequence Data ; Phylogeny ; Plastids/chemistry/genetics/metabolism ; Protein Transport ; Protozoan Proteins/chemistry/genetics/*metabolism ; Sequence Alignment ; *Symbiosis ; }, abstract = {The plastid of chlorarachniophytes is distinguished by the retention of a relict nucleus (nucleomorph) derived from a green algal endosymbiont, which is located in the periplastidal compartment (PPC). The nucleomorph genome of a chlorarachniophyte, Bigelowiella natans, encodes several plastid-targeted proteins and hundreds of housekeeping proteins, but it lacks many fundamental genes to maintain itself. Here we report the first two host nucleus-encoded genes for proteins targeted to the nucleomorph, histone H2A and H2B. We identified 20 histone genes from the host nuclear genome, and based on phylogenetic analyses predicted that most of these are derived from the host, but that two histone genes are symbiont-derived. The genes both encode N-terminal extensions resembling PPC targeting signals, further suggesting they function in the nucleomorph. Using green fluorescent protein (GFP) fusion proteins expressed in transformed cells, we confirmed that the putative symbiont H2A and H2B were targeted into the nucleomorph, whereas putative host proteins were localized to the host nucleus. Furthermore, we have developed a method to temporarily synchronize B. natans cells, and confirmed that both host and symbiont histone expression is controlled during the cell cycle. Our findings provide the first evidence of how the nucleomorph may be regulated by host-encoded gene products.}, }
@article {pmid21469937, year = {2011}, author = {Gough, C and Cullimore, J}, title = {Lipo-chitooligosaccharide signaling in endosymbiotic plant-microbe interactions.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {24}, number = {8}, pages = {867-878}, doi = {10.1094/MPMI-01-11-0019}, pmid = {21469937}, issn = {0894-0282}, mesh = {Gene Expression Regulation, Plant/physiology ; Mycorrhizae/*metabolism ; Oligosaccharides/*metabolism ; Plant Roots/metabolism/microbiology ; Plants/*metabolism/*microbiology ; Signal Transduction ; }, abstract = {The arbuscular mycorrhizal (AM) and the rhizobia-legume (RL) root endosymbioses are established as a result of signal exchange in which there is mutual recognition of diffusible signals produced by plant and microbial partners. It was discovered 20 years ago that the key symbiotic signals produced by rhizobial bacteria are lipo-chitooligosaccharides (LCO), called Nod factors. These LCO are perceived via lysin-motif (LysM) receptors and activate a signaling pathway called the common symbiotic pathway (CSP), which controls both the RL and the AM symbioses. Recent work has established that an AM fungus, Glomus intraradices, also produces LCO that activate the CSP, leading to induction of gene expression and root branching in Medicago truncatula. These Myc-LCO also stimulate mycorrhization in diverse plants. In addition, work on the nonlegume Parasponia andersonii has shown that a LysM receptor is required for both successful mycorrhization and nodulation. Together these studies show that structurally related signals and the LysM receptor family are key components of both nodulation and mycorrhization. LysM receptors are also involved in the perception of chitooligosaccharides (CO), which are derived from fungal cell walls and elicit defense responses and resistance to pathogens in diverse plants. The discovery of Myc-LCO and a LysM receptor required for the AM symbiosis, therefore, not only raises questions of how legume plants discriminate fungal and bacterial endosymbionts but also, more generally, of how plants discriminate endosymbionts from pathogenic microorganisms using structurally related LCO and CO signals and of how these perception mechanisms have evolved.}, }
@article {pmid21460541, year = {2011}, author = {Hancock, PA and Sinkins, SP and Godfray, HC}, title = {Population dynamic models of the spread of Wolbachia.}, journal = {The American naturalist}, volume = {177}, number = {3}, pages = {323-333}, doi = {10.1086/658121}, pmid = {21460541}, issn = {1537-5323}, support = {079059/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Aedes/*microbiology ; Animal Migration ; Animals ; Host-Pathogen Interactions ; Insect Vectors/microbiology ; Life Cycle Stages ; *Models, Biological ; Population Density ; Population Dynamics ; Seasons ; *Symbiosis ; *Wolbachia ; }, abstract = {Wolbachia are endosymbionts that are found in many insect species and can spread rapidly when introduced into a naive host population. Most Wolbachia spread when their infection frequency exceeds a threshold normally calculated using purely population genetic models. However, spread may also depend on the population dynamics of the insect host. We develop models to explore interactions between host population dynamics and Wolbachia infection frequency for an age-structured insect population regulated by larval density dependence. We first derive a new expression for the threshold frequency that extends existing theory to incorporate important details of the insect's life history. In the presence of immigration and emigration, the threshold also depends on the form of density-dependent regulation. We show how the type of immigration (constant or pulsed) and the temporal dynamics of the host population can strongly affect the spread of Wolbachia. The results help understand the natural dynamics of Wolbachia infections and aid the design of programs to introduce Wolbachia to control insects that are disease vectors or pests.}, }
@article {pmid21457543, year = {2011}, author = {Sun, XJ and Xiao, JH and Cook, JM and Feng, G and Huang, DW}, title = {Comparisons of host mitochondrial, nuclear and endosymbiont bacterial genes reveal cryptic fig wasp species and the effects of Wolbachia on host mtDNA evolution and diversity.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {86}, pmid = {21457543}, issn = {1471-2148}, mesh = {Animals ; Bacterial Proteins/*genetics ; DNA, Mitochondrial/*genetics ; *Evolution, Molecular ; Ficus ; *Genetic Variation ; Insect Proteins/genetics ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; Wasps/classification/*genetics/*microbiology/physiology ; Wolbachia/*genetics/physiology ; }, abstract = {BACKGROUND: Figs and fig-pollinating wasp species usually display a highly specific one-to-one association. However, more and more studies have revealed that the "one-to-one" rule has been broken. Co-pollinators have been reported, but we do not yet know how they evolve. They may evolve from insect speciation induced or facilitated by Wolbachia which can manipulate host reproduction and induce reproductive isolation. In addition, Wolbachia can affect host mitochondrial DNA evolution, because of the linkage between Wolbachia and associated mitochondrial haplotypes, and thus confound host phylogeny based on mtDNA. Previous research has shown that fig wasps have the highest incidence of Wolbachia infection in all insect taxa, and Wolbachia may have great influence on fig wasp biology. Therefore, we look forward to understanding the influence of Wolbachia on mitochondrial DNA evolution and speciation in fig wasps.<br><br>RESULTS: We surveyed 76 pollinator wasp specimens from nine Ficus microcarpa trees each growing at a different location in Hainan and Fujian Provinces, China. We found that all wasps were morphologically identified as Eupristina verticillata, but diverged into three clades with 4.22-5.28% mtDNA divergence and 2.29-20.72% nuclear gene divergence. We also found very strong concordance between E. verticillata clades and Wolbachia infection status, and the predicted effects of Wolbachia on both mtDNA diversity and evolution by decreasing mitochondrial haplotypes.<br><br>CONCLUSIONS: Our study reveals that the pollinating wasp E. verticillata on F. microcarpa has diverged into three cryptic species, and Wolbachia may have a role in this divergence. The results also indicate that Wolbachia strains infecting E. verticillata have likely resulted in selective sweeps on host mitochondrial DNA.}, }
@article {pmid23761245, year = {2011}, author = {Anbutsu, H and Fukatsu, T}, title = {Spiroplasma as a model insect endosymbiont.}, journal = {Environmental microbiology reports}, volume = {3}, number = {2}, pages = {144-153}, doi = {10.1111/j.1758-2229.2010.00240.x}, pmid = {23761245}, issn = {1758-2229}, abstract = {Members of the genus Spiroplasma are actively motile and helical bacteria of the class Mollicutes, which are associated with a variety of arthropods and plants. Some spiroplasmas cause female-biased sex ratios of their host insects as a result of selective death of the male offspring during embryogenesis. Several strains of male-killing spiroplasmas have been successfully transfected into Drosophila melanogaster by haemolymph injection and maintained in laboratory fly stocks. Spiroplasma-Drosophila endosymbiosis represents an ideal model system for analysing the molecular mechanisms underlying host-symbiont interactions. The infection dynamics exhibited by the symbiont within the host, the effects of external and environmental factors on the symbiotic association and symbiont interactions with the host's immune system have been investigated using this system. Comparisons between a male-killing Spiroplasma strain and its non-male-killing variant revealed that, in addition to different male-killing abilities, they also differed in infection dynamics and resistance to host innate immunity. It is currently unclear whether these different phenotypes are interconnected to each other. However, if so, such pleiotropy could facilitate our understanding of the genetic and molecular mechanisms of the endosymbiotic system.}, }
@article {pmid21451589, year = {2011}, author = {Yizhak, K and Tuller, T and Papp, B and Ruppin, E}, title = {Metabolic modeling of endosymbiont genome reduction on a temporal scale.}, journal = {Molecular systems biology}, volume = {7}, number = {}, pages = {479}, pmid = {21451589}, issn = {1744-4292}, mesh = {Animals ; Aphids/microbiology ; Biological Evolution ; Buchnera/*genetics/metabolism ; Computer Simulation ; DNA, Bacterial ; Escherichia coli/*genetics/metabolism ; Genome, Bacterial ; Metabolic Networks and Pathways/*genetics ; Models, Biological ; Phylogeny ; Selection, Genetic ; Symbiosis/*genetics ; Systems Biology/methods ; Time Factors ; }, abstract = {A fundamental challenge in Systems Biology is whether a cell-scale metabolic model can predict patterns of genome evolution by realistically accounting for associated biochemical constraints. Here, we study the order in which genes are lost in an in silico evolutionary process, leading from the metabolic network of Escherichia coli to that of the endosymbiont Buchnera aphidicola. We examine how this order correlates with the order by which the genes were actually lost, as estimated from a phylogenetic reconstruction. By optimizing this correlation across the space of potential growth and biomass conditions, we compute an upper bound estimate on the model's prediction accuracy (R=0.54). The model's network-based predictive ability outperforms predictions obtained using genomic features of individual genes, reflecting the effect of selection imposed by metabolic stoichiometric constraints. Thus, while the timing of gene loss might be expected to be a completely stochastic evolutionary process, remarkably, we find that metabolic considerations, on their own, make a marked 40% contribution to determining when such losses occur.}, }
@article {pmid21451583, year = {2011}, author = {Santos, Ede O and Alves, N and Dias, GM and Mazotto, AM and Vermelho, A and Vora, GJ and Wilson, B and Beltran, VH and Bourne, DG and Le Roux, F and Thompson, FL}, title = {Genomic and proteomic analyses of the coral pathogen Vibrio coralliilyticus reveal a diverse virulence repertoire.}, journal = {The ISME journal}, volume = {5}, number = {9}, pages = {1471-1483}, pmid = {21451583}, issn = {1751-7370}, mesh = {Animals ; Anthozoa/*microbiology ; Dinoflagellida/genetics ; Genome, Bacterial ; Metalloproteases/genetics ; Proteomics ; Vibrio/*genetics/*pathogenicity ; Virulence ; Virulence Factors/genetics ; }, abstract = {Vibrio coralliilyticus has been implicated as an important pathogen of coral species worldwide. In this study, the nearly complete genome of Vibrio coralliilyticus strain P1 (LMG23696) was sequenced and proteases implicated in virulence of the strain were specifically investigated. The genome sequence of P1 (5,513,256 bp in size) consisted of 5222 coding sequences and 58 RNA genes (53 tRNAs and at least 5 rRNAs). Seventeen metalloprotease and effector (vgrG, hlyA and hcp) genes were identified in the genome and expressed proteases were also detected in the secretome of P1. As the VcpA zinc-metalloprotease has been considered an important virulence factor of V. coralliilyticus, a vcpA deletion mutant was constructed to evaluate the effect of this gene in animal pathogenesis. Both wild-type and mutant (ΔvcpA) strains exhibited similar virulence characteristics that resulted in high mortality in Artemia and Drosophila pathogenicity bioassays and strong photosystem II inactivation of the coral dinoflagellate endosymbiont (Symbiodinium). In contrast, the ΔvcpA mutant demonstrated higher hemolytic activity and secreted 18 proteins not secreted by the wild type. These proteins included four types of metalloproteases, a chitinase, a hemolysin-related protein RbmC, the Hcp protein and 12 hypothetical proteins. Overall, the results of this study indicate that V. coralliilyticus strain P1 has a diverse virulence repertoire that possibly enables this bacterium to be an efficient animal pathogen.}, }
@article {pmid21450721, year = {2011}, author = {Longdon, B and Wilfert, L and Osei-Poku, J and Cagney, H and Obbard, DJ and Jiggins, FM}, title = {Host-switching by a vertically transmitted rhabdovirus in Drosophila.}, journal = {Biology letters}, volume = {7}, number = {5}, pages = {747-750}, pmid = {21450721}, issn = {1744-957X}, support = {G0900740/MRC_/Medical Research Council/United Kingdom ; 085064/Z/08/Z/WT_/Wellcome Trust/United Kingdom ; /BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bayes Theorem ; Drosophila/*virology ; *Host-Pathogen Interactions ; Phylogeny ; Rhabdoviridae/classification/*physiology ; Symbiosis ; }, abstract = {A diverse range of endosymbionts are found within the cells of animals. As these endosymbionts are normally vertically transmitted, we might expect their evolutionary history to be dominated by host-fidelity and cospeciation with the host. However, studies of bacterial endosymbionts have shown that while this is true for some mutualists, parasites often move horizontally between host lineages over evolutionary timescales. For the first time, to our knowledge, we have investigated whether this is also the case for vertically transmitted viruses. Here, we describe four new sigma viruses, a group of vertically transmitted rhabdoviruses previously known in Drosophila. Using sequence data from these new viruses, and the previously described sigma viruses, we show that they have switched between hosts during their evolutionary history. Our results suggest that sigma virus infections may be short-lived in a given host lineage, so that their long-term persistence relies on rare horizontal transmission events between hosts.}, }
@article {pmid21445333, year = {2011}, author = {Ritchie, SA and Johnson, PH and Freeman, AJ and Odell, RG and Graham, N and Dejong, PA and Standfield, GW and Sale, RW and O'Neill, SL}, title = {A secure semi-field system for the study of Aedes aegypti.}, journal = {PLoS neglected tropical diseases}, volume = {5}, number = {3}, pages = {e988}, pmid = {21445333}, issn = {1935-2735}, mesh = {Aedes/*growth &amp; development/*microbiology ; Animals ; Australia ; Containment of Biohazards/methods ; Entomology/*methods ; Female ; Male ; Mosquito Control/*methods ; Pest Control, Biological/methods ; Wolbachia/*pathogenicity ; }, abstract = {BACKGROUND: New contained semi-field cages are being developed and used to test novel vector control strategies of dengue and malaria vectors. We herein describe a new Quarantine Insectary Level-2 (QIC-2) laboratory and field cages (James Cook University Mosquito Research Facility Semi-Field System; MRF SFS) that are being used to measure the impact of the endosymbiont Wolbachia pipientis on populations of Aedes aegypti in Cairns Australia.<br><br>The MRF consists of a single QIC-2 laboratory/insectary that connects through a central corridor to two identical QIC-2 semi-field cages. The semi-field cages are constructed of two layers of 0.25 mm stainless steel wire mesh to prevent escape of mosquitoes and ingress of other insects. The cages are covered by an aluminum security mesh to prevent penetration of the cages by branches and other missiles in the advent of a tropical cyclone. Parts of the cage are protected from UV light and rainfall by 90% shade cloth and a vinyl cover. A wooden structure simulating the understory of a Queenslander-style house is also situated at one end of each cage. The remainder of the internal aspect of the cage is covered with mulch and potted plants to emulate a typical yard. An air conditioning system comprised of two external ACs that feed cooled, moistened air into the cage units. The air is released from the central ceiling beam from a long cloth tube that disperses the airflow and also prevents mosquitoes from escaping the cage via the AC system. Sensors located inside and outside the cage monitor ambient temperature and relative humidity, with AC controlled to match ambient conditions. Data loggers set in the cages and outside found a <2 &#xb0;C temperature difference. Additional security features include air curtains over exit doors, sticky traps to monitor for escaping mosquitoes between layers of the mesh, a lockable vestibule leading from the connecting corridor to the cage and from inside to outside of the insectary, and screened (0.25 mm mesh) drains within the insectary and the cage. A set of standard operating procedures (SOP) has been developed to ensure that security is maintained and for enhanced surveillance for escaping mosquitoes on the JCU campus where the MRF is located. A cohort of male and female Aedes aegypti mosquitoes were released in the cage and sampled every 3-4 days to determine daily survival within the cage; log linear regression from BG-sentinel trapping collections produced an estimated daily survival of 0.93 and 0.78 for females and males, respectively.<br><br>CONCLUSIONS/SIGNIFICANCE: The MRF SFS allows us to test novel control strategies within a secure, contained environment. The air-conditioning system maintains conditions within the MRF cages comparable to outside ambient conditions. This cage provides a realistic transitional platform between the laboratory and the field in which to test novel control measures on quarantine level insects.}, }
@article {pmid21444293, year = {2011}, author = {Kořený, L and Oborník, M}, title = {Sequence evidence for the presence of two tetrapyrrole pathways in Euglena gracilis.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {359-364}, pmid = {21444293}, issn = {1759-6653}, mesh = {*Biological Evolution ; *Biosynthetic Pathways ; Chlorophyta/physiology ; Euglena gracilis/classification/genetics/*physiology ; Molecular Sequence Data ; Phylogeny ; Plastids/genetics/metabolism ; Protozoan Proteins/genetics/metabolism ; Symbiosis ; Tetrapyrroles/*biosynthesis ; }, abstract = {Genes encoding enzymes of the tetrapyrrole biosynthetic pathway were searched within Euglena gracilis EST databases and 454 genome reads and their 5' end regions were sequenced when not available. Phylogenetic analyses and protein localization predictions support the hypothesis concerning the presence of two separated tetrapyrrole pathways in E. gracilis. One of these pathways resembles the heme synthesis in primarily heterotrophic eukaryotes and was presumably present in the host cell prior to secondary endosymbiosis with a green alga. The second pathway is similar to the plastid-localized tetrapyrrole syntheses in plants and photosynthetic algae. It appears to be localized to the secondary plastid, presumably derived from an algal endosymbiont and probably serves only for the production of plastidial heme and chlorophyll. Thus, E. gracilis represents an evolutionary intermediate in a metabolic transformation of a primary heterotroph to a photoautotroph through secondary endosymbiosis. We propose here that the tetrapyrrole pathway serves as a highly informative marker for the evolution of plastids and plays a crucial role in the loss of plastids.}, }
@article {pmid21440662, year = {2011}, author = {Sethi, A and Xue, QG and La Peyre, JF and Delatte, J and Husseneder, C}, title = {Dual origin of gut proteases in Formosan subterranean termites (Coptotermes formosanus Shiraki) (Isoptera: Rhinotermitidae).}, journal = {Comparative biochemistry and physiology. Part A, Molecular &amp; integrative physiology}, volume = {159}, number = {3}, pages = {261-267}, doi = {10.1016/j.cbpa.2011.03.012}, pmid = {21440662}, issn = {1531-4332}, mesh = {Animals ; Electrophoresis, Polyacrylamide Gel ; Intestines/*enzymology ; Isoptera/*enzymology ; Peptide Hydrolases/*metabolism ; Substrate Specificity ; }, abstract = {Cellulose digestion in lower termites, mediated by carbohydrases originating from both termite and endosymbionts, is well characterized. In contrast, limited information exists on gut proteases of lower termites, their origins and roles in termite nutrition. The objective of this study was to characterize gut proteases of the Formosan subterranean termite (Coptotermes formosanus Shiraki) (Isoptera: Rhinotermitidae). The protease activity of extracts from gut tissues (fore-, mid- and hindgut) and protozoa isolated from hindguts of termite workers was quantified using hide powder azure as a substrate and further characterized by zymography with gelatin SDS-PAGE. Midgut extracts showed the highest protease activity followed by the protozoa extracts. High level of protease activity was also detected in protozoa culture supernatants after 24 h incubation. Incubation of gut and protozoa extracts with class-specific protease inhibitors revealed that most of the proteases were serine proteases. All proteolytic bands identified after gelatin SDS-PAGE were also inhibited by serine protease inhibitors. Finally, incubation with chromogenic substrates indicated that extracts from fore- and hindgut tissues possessed proteases with almost exclusively trypsin-like activity while both midgut and protozoa extracts possessed proteases with trypsin-like and subtilisin/chymotrypsin-like activities. However, protozoa proteases were distinct from midgut proteases (with different molecular mass). Our results suggest that the Formosan subterranean termite not only produces endogenous proteases in its gut tissues, but also possesses proteases originating from its protozoan symbionts.}, }
@article {pmid21440063, year = {2011}, author = {Ratzka, C and Liang, C and Dandekar, T and Gross, R and Feldhaar, H}, title = {Immune response of the ant Camponotus floridanus against pathogens and its obligate mutualistic endosymbiont.}, journal = {Insect biochemistry and molecular biology}, volume = {41}, number = {8}, pages = {529-536}, doi = {10.1016/j.ibmb.2011.03.002}, pmid = {21440063}, issn = {1879-0240}, mesh = {Animals ; *Ants/genetics/immunology/microbiology ; Bacterial Load ; DNA, Bacterial/analysis/biosynthesis ; Defensins/genetics/immunology/metabolism ; Digestive System/*immunology/microbiology ; Enterobacteriaceae/*immunology ; Female ; Gene Expression ; Gene Expression Profiling ; Gene Library ; Genome, Insect ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Heat-Shock Proteins/genetics/metabolism ; Immunity/*genetics ; Mitogen-Activated Protein Kinase Kinases/genetics/metabolism ; Nucleic Acid Hybridization ; Ovary/*immunology/microbiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Signal Transduction ; Symbiosis/genetics/*immunology ; }, abstract = {Numerous insect species harbor mutualistic endosymbionts that play a role in nutrient cycling or confer other fitness benefits to their hosts. Insect hosts face the problem of having to maintain such mutualistic bacteria while staging an immune response towards pathogens upon infection. In addition, hosts may regulate the number of endosymbionts present in their tissues via the innate immune system. Camponotus floridanus ants harbor the obligate endosymbiont Blochmannia floridanus in specialized midgut cells and ovaries. We identified genes transcriptionally induced in response to septic injury by suppression subtractive hybridization (SSH). Among these were genes involved in pathogen recognition (e.g. GNBP), signal transduction (e.g. MAPK-kinase), antimicrobial activity (e.g. defensin and hymenoptaecin), or general stress response (e.g. heat shock protein). A quantitative analysis of immune-gene expression revealed different expression kinetics of individual factors and also characteristic expression profiles after injection of gram-negative and gram-positive bacteria. Likewise, B. floridanus injected into the hemocoel elicited a comparable immune response of its host C. floridanus. Thus, the host immune system may contribute to controlling the endosymbiont population.}, }
@article {pmid21426381, year = {2011}, author = {Kador, M and Horn, MA and Dettner, K}, title = {Novel oligonucleotide probes for in situ detection of pederin-producing endosymbionts of Paederus riparius rove beetles (Coleoptera: Staphylinidae).}, journal = {FEMS microbiology letters}, volume = {319}, number = {1}, pages = {73-81}, doi = {10.1111/j.1574-6968.2011.02270.x}, pmid = {21426381}, issn = {1574-6968}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Coleoptera/*microbiology/physiology ; Female ; In Situ Hybridization, Fluorescence/instrumentation/methods ; Oligonucleotide Probes/*genetics ; Ovum/microbiology ; Pyrans/*metabolism ; *Symbiosis ; }, abstract = {Bacterial endosymbionts from female Paederus rove beetles are hitherto uncultured, phylogenetically related to Pseudomonas sp., and produce the polyketide pederin, which exhibits strong cytotoxic effects and antitumoral activities. The location of such endosymbionts inside beetles and on beetles' eggs is hypothesized based on indirect evidence rather than elucidated. Thus, an endosymbiont-specific and a competitor oligonucleotide probe (Cy3-labelled PAE444 and unlabelled cPAE444, respectively) were designed and utilized for FISH with semi-thin sections of Paederus riparius eggs. Cy3-PAE444-positive cells were densely packed and covered the whole eggshell. Hundred percent of EUB338-Mix-positive total bacterial cells were PAE444 positive, indicating a biofilm dominated by Paederus endosymbionts. Analysis of different egg deposition stadiums by electron microscopy and pks (polyketide synthase gene, a structural gene associated with pederin biosynthesis)-PCR supported results obtained by FISH and revealed that the endosymbiont-containing layer is applied to the eggshell inside the efferent duct. These findings suggest that P. riparius endosymbionts are located inside unknown structures of the female genitalia, which allow for a well-regulated release of endosymbionts during oviposition. The novel oligonucleotide probes developed in this study will facilitate (1) the identification of symbiont-containing structures within genitalia of their beetle hosts and (2) directed cultivation approaches in the future.}, }
@article {pmid21420905, year = {2011}, author = {Teixeira, MM and Borghesan, TC and Ferreira, RC and Santos, MA and Takata, CS and Campaner, M and Nunes, VL and Milder, RV and de Souza, W and Camargo, EP}, title = {Phylogenetic validation of the genera Angomonas and Strigomonas of trypanosomatids harboring bacterial endosymbionts with the description of new species of trypanosomatids and of proteobacterial symbionts.}, journal = {Protist}, volume = {162}, number = {3}, pages = {503-524}, doi = {10.1016/j.protis.2011.01.001}, pmid = {21420905}, issn = {1618-0941}, mesh = {Base Sequence ; Betaproteobacteria/*classification/*genetics/isolation &amp; purification/ultrastructure ; Biological Evolution ; DNA Barcoding, Taxonomic/methods ; DNA, Bacterial/chemistry/genetics ; DNA, Intergenic/chemistry/genetics ; DNA, Kinetoplast/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Likelihood Functions ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Genetic ; RNA, Ribosomal, 16S/genetics ; Ribosome Subunits, Small/genetics ; Sequence Analysis, DNA ; *Symbiosis/genetics ; Trypanosomatina/*classification/*genetics/isolation &amp; purification/ultrastructure ; }, abstract = {We comparatively examined the nutritional, molecular and optical and electron microscopical characteristics of reference species and new isolates of trypanosomatids harboring bacterial endosymbionts. Sequencing of the V7V8 region of the small subunit of the ribosomal RNA (SSU rRNA) gene distinguished six major genotypes among the 13 isolates examined. The entire sequences of the SSU rRNA and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) genes were obtained for phylogenetic analyses. In the resulting phylogenetic trees, the symbiont-harboring species clustered as a major clade comprising two subclades that corresponded to the proposed genera Angomonas and Strigomonas. The genus Angomonas comprised 10 flagellates including former Crithidia deanei and C. desouzai plus a new species. The genus Strigomonas included former Crithidia oncopelti and Blastocrithidia culicis plus a new species. Sequences from the internal transcribed spacer of ribosomal DNA (ITS rDNA) and size polymorphism of kinetoplast DNA (kDNA) minicircles revealed considerable genetic heterogeneity within the genera Angomonas and Strigomonas. Phylogenetic analyses based on 16S rDNA and ITS rDNA sequences demonstrated that all of the endosymbionts belonged to the Betaproteobacteria and revealed three new species. The congruence of the phylogenetic trees of trypanosomatids and their symbionts support a co-divergent host-symbiont evolutionary history.}, }
@article {pmid21410573, year = {2011}, author = {van Oppen, MJ and Bongaerts, P and Underwood, JN and Peplow, LM and Cooper, TF}, title = {The role of deep reefs in shallow reef recovery: an assessment of vertical connectivity in a brooding coral from west and east Australia.}, journal = {Molecular ecology}, volume = {20}, number = {8}, pages = {1647-1660}, doi = {10.1111/j.1365-294X.2011.05050.x}, pmid = {21410573}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*genetics ; Australia ; Chlorophyta/genetics ; Cluster Analysis ; *Coral Reefs ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; *Genetic Variation ; *Genetics, Population ; Genotype ; Microsatellite Repeats ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Approximately one quarter of zooxanthellate coral species have a depth distribution from shallow waters (<30 m) down to mesophotic depths of 30-60 m. The deeper populations of such species are less likely to be affected by certain environmental perturbations, including high temperature/high irradiance causing coral bleaching. This has led to the hypothesis that deep populations may serve as refuges and a source of recruits for shallow reef habitats. The extent of vertical connectivity of reef coral species, however, is largely unquantified. Using 10 coral host microsatellite loci and sequences of the host mtDNA putative control region, as well as ribosomal DNA (rDNA) ITS2 sequences of the coral's algal endosymbionts (Symbiodinium), we examine population structure, connectivity and symbiont specificity in the brooding coral Seriatopora hystrix across a depth profile in both northwest (Scott Reef) and northeast Australia (Yonge Reef). Strong genetic structuring over depth was observed in both regions based on the microsatellite loci; however, Yonge Reef exhibited an additional partitioning of mtDNA lineages (associated with specific symbiont ITS2 types), whereas Scott Reef was dominated by a single mtDNA lineage (with no apparent host-symbiont specificity). Evidence for recruitment of larvae of deep water origin into shallow habitats was found at Scott Reef, suggesting that recovery of shallow water habitats may be aided by migration from deep water refuges. Conversely, no migration from the genetically divergent deep slope populations into the shallow habitats was evident at Yonge Reef, making recovery of shallow habitats from deeper waters at this location highly unlikely.}, }
@article {pmid21410491, year = {2011}, author = {Zhang, X and Norris, DE and Rasgon, JL}, title = {Distribution and molecular characterization of Wolbachia endosymbionts and filarial nematodes in Maryland populations of the lone star tick (Amblyomma americanum).}, journal = {FEMS microbiology ecology}, volume = {77}, number = {1}, pages = {50-56}, pmid = {21410491}, issn = {1574-6941}, support = {R21 AI070178/AI/NIAID NIH HHS/United States ; R21AI067386/AI/NIAID NIH HHS/United States ; R21 AI067386/AI/NIAID NIH HHS/United States ; R03AI079297/AI/NIAID NIH HHS/United States ; R03 AI079297/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Female ; Filarioidea/classification/*genetics/isolation &amp; purification ; Ixodidae/*microbiology/*parasitology ; Male ; Maryland ; Multilocus Sequence Typing ; Nematoda/microbiology ; Nymph/microbiology/parasitology ; Phylogeny ; Polymerase Chain Reaction ; *Symbiosis ; Wolbachia/classification/*genetics/isolation &amp; purification ; }, abstract = {The lone star tick Amblyomma americanum is host to a wide diversity of endosymbiotic bacteria. We identified a novel Wolbachia symbiont infecting A. americanum. Multilocus sequence typing phylogenetically placed the endosymbiont in the increasingly diverse F supergroup. We assayed a total of 1031 ticks (119 females, 78 males and 834 nymphs in 89 pools) from 16 Maryland populations for infection. Infection frequencies in the natural populations were approximately 5% in females and <2% (minimum infection rate) in nymphs; infection was not detected in males. Infected populations were only observed in southern Maryland, suggesting the possibility that Wolbachia is currently invading Maryland A. americanum populations. Because F supergroup Wolbachia have been detected previously in filarial nematodes, tick samples were assayed for nematodes by PCR. Filarial nematodes were detected in 70% and 9% of Wolbachia-positive and Wolbachia-negative tick samples, respectively. While nematodes were more common in Wolbachia-positive tick samples, the lack of a strict infection concordance (Wolbachia-positive, nematode-negative and Wolbachia-negative, nematode-positive ticks) suggests that Wolbachia prevalence in ticks is not due to nematode infection. Supporting this hypothesis, phylogenetic analysis indicated that the nematodes were likely a novel species within the genus Acanthocheilonema, which has been previously shown to be Wolbachia-free.}, }
@article {pmid21405987, year = {2011}, author = {Robledo, M and Jiménez-Zurdo, JI and Soto, MJ and Velázquez, E and Dazzo, F and Martínez-Molina, E and Mateos, PF}, title = {Development of functional symbiotic white clover root hairs and nodules requires tightly regulated production of rhizobial cellulase CelC2.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {24}, number = {7}, pages = {798-807}, doi = {10.1094/MPMI-10-10-0249}, pmid = {21405987}, issn = {0894-0282}, mesh = {Cell Wall/*metabolism ; Cellulase/*biosynthesis ; Cellulose/metabolism ; Gene Expression Regulation, Plant ; Genes, Bacterial ; Medicago/genetics/growth &amp; development/metabolism/*microbiology ; Nitrogen Fixation/*genetics ; Phenotype ; Plant Roots/growth &amp; development/metabolism/microbiology ; Reactive Oxygen Species/metabolism ; Rhizobium leguminosarum/*enzymology/genetics/physiology ; Root Nodules, Plant/*growth &amp; development/metabolism/*microbiology ; *Symbiosis ; }, abstract = {The establishment of rhizobia as nitrogen-fixing endosymbionts within legume root nodules requires the disruption of the plant cell wall to breach the host barrier at strategic infection sites in the root hair tip and at points of bacterial release from infection threads (IT) within the root cortex. We previously found that Rhizobium leguminosarum bv. trifolii uses its chromosomally encoded CelC2 cellulase to erode the noncrystalline wall at the apex of root hairs, thereby creating the primary portal of its entry into white clover roots. Here, we show that a recombinant derivative of R. leguminosarum bv. trifolii ANU843 that constitutively overproduces the CelC2 enzyme has increased competitiveness in occupying aberrant nodule-like root structures on clover that are inefficient in nitrogen fixation. This aberrant symbiotic phenotype involves an extensive uncontrolled degradation of the host cell walls restricted to the expected infection sites at tips of deformed root hairs and significantly enlarged infection droplets at termini of wider IT within the nodule infection zone. Furthermore, signs of elevated plant host defense as indicated by reactive oxygen species production in root tissues were more evident during infection by the recombinant strain than its wild-type parent. Our data further support the role of the rhizobial CelC2 cell wall-degrading enzyme in primary infection, and show evidence of its importance in secondary symbiotic infection and tight regulation of its production to establish an effective nitrogen-fixing root nodule symbiosis.}, }
@article {pmid21398605, year = {2011}, author = {Specht, S and Frank, JK and Alferink, J and Dubben, B and Layland, LE and Denece, G and Bain, O and Förster, I and Kirschning, CJ and Martin, C and Hoerauf, A}, title = {CCL17 controls mast cells for the defense against filarial larval entry.}, journal = {Journal of immunology (Baltimore, Md. : 1950)}, volume = {186}, number = {8}, pages = {4845-4852}, doi = {10.4049/jimmunol.1000612}, pmid = {21398605}, issn = {1550-6606}, mesh = {Animals ; Antigens, Helminth/immunology ; Bone Marrow Cells/immunology/metabolism ; Capillary Permeability/immunology ; Cell Degranulation/immunology ; Cells, Cultured ; Chemokine CCL17/genetics/*immunology/metabolism ; Dendritic Cells/immunology/metabolism ; Female ; Filariasis/genetics/*immunology/parasitology ; Filarioidea/*immunology/microbiology/physiology ; Flow Cytometry ; Green Fluorescent Proteins/genetics/metabolism ; Host-Parasite Interactions/immunology ; Larva/immunology/microbiology/physiology ; Lung/immunology/metabolism ; Lymph Nodes/immunology/metabolism ; Mast Cells/*immunology/physiology ; Mice ; Mice, Inbred C3H ; Mice, Knockout ; Microscopy, Confocal ; Skin/immunology/metabolism ; Time Factors ; Wolbachia/immunology ; }, abstract = {Filarial parasites have to trespass many barriers to successfully settle within their mammalian host, which is equipped with mechanical borders and complex weaponry of an evolved immune system. However, little is known about mechanisms of early local events in filarial infections. In this study, bone marrow-derived dendritic cells not only upregulated activation markers CD40 and CD80 upon in vitro stimulation with filarial extracts, but also secreted CCL17, a chemokine known to be produced upon microbial challenge. Mice deficient for CCL17 had an up to 4-fold higher worm burden compared with controls by day 10 of infection with the murine filaria Litomosoides sigmodontis. Also, numbers of mast cells (MCs) invading the skin and degranulation were significantly increased, which was associated with enhanced vascular permeability and larval establishment. This phenotype was reverted by inhibition of MC degranulation with disodium cromoglycate or by blockade of histamine. In addition, we showed that CCL17-mediated vascular permeability was dependent on the presence of Wolbachia endosymbionts and TLR2. Our findings reveal that CCL17 controls filarial larval entry by limiting MC-dependent vascular permeability.}, }
@article {pmid21379323, year = {2011}, author = {Mendonça, AG and Alves, RJ and Pereira-Leal, JB}, title = {Loss of genetic redundancy in reductive genome evolution.}, journal = {PLoS computational biology}, volume = {7}, number = {2}, pages = {e1001082}, pmid = {21379323}, issn = {1553-7358}, mesh = {Bacterial Proteins/genetics/physiology ; *Evolution, Molecular ; *Genome, Bacterial ; Genomics/*methods ; *Models, Genetic ; Sequence Deletion ; Symbiosis/genetics ; }, abstract = {Biological systems evolved to be functionally robust in uncertain environments, but also highly adaptable. Such robustness is partly achieved by genetic redundancy, where the failure of a specific component through mutation or environmental challenge can be compensated by duplicate components capable of performing, to a limited extent, the same function. Highly variable environments require very robust systems. Conversely, predictable environments should not place a high selective value on robustness. Here we test this hypothesis by investigating the evolutionary dynamics of genetic redundancy in extremely reduced genomes, found mostly in intracellular parasites and endosymbionts. By combining data analysis with simulations of genome evolution we show that in the extensive gene loss suffered by reduced genomes there is a selective drive to keep the diversity of protein families while sacrificing paralogy. We show that this is not a by-product of the known drivers of genome reduction and that there is very limited convergence to a common core of families, indicating that the repertoire of protein families in reduced genomes is the result of historical contingency and niche-specific adaptations. We propose that our observations reflect a loss of genetic redundancy due to a decreased selection for robustness in a predictable environment.}, }
@article {pmid21378132, year = {2012}, author = {Lemaire, B and Van Oevelen, S and De Block, P and Verstraete, B and Smets, E and Prinsen, E and Dessein, S}, title = {Identification of the bacterial endosymbionts in leaf nodules of Pavetta (Rubiaceae).}, journal = {International journal of systematic and evolutionary microbiology}, volume = {62}, number = {Pt 1}, pages = {202-209}, doi = {10.1099/ijs.0.028019-0}, pmid = {21378132}, issn = {1466-5034}, mesh = {Burkholderia/*classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA Gyrase/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Molecular Sequence Data ; Phylogeny ; Plant Leaves/*microbiology/*physiology ; RNA, Ribosomal, 16S/genetics ; Rec A Recombinases/genetics ; Rubiaceae/*microbiology/*physiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Three genera in the Rubiaceae (Pavetta, Psychotria and Sericanthe) harbour bacterial endosymbionts within leaf nodules or galls. The present paper identifies the bacterial endophytes in three leaf-nodulating Pavetta species. In order to reveal their identity and assess their phylogenetic position, 16S rRNA, recA and gyrB genes were sequenced from an extensive sampling of Burkholderia strains. This multigene approach results in a robust phylogeny, which places the bacterial endosymbionts of Pavetta at two distinct positions within the genus Burkholderia (class Betaproteobacteria), suggesting that leaf-nodulating endosymbionts within Pavetta have different origins. The endophytes of nodulated Psychotria species were recognized as the closest relatives to the Pavetta endosymbionts. Our results suggest that the endosymbionts of Pavetta represent novel species, which can be classified as 'Candidatus Burkholderia hispidae', 'Candidatus Burkholderia rigidae' and 'Candidatus Burkholderia schumannianae'.}, }
@article {pmid21378044, year = {2011}, author = {Kuechler, SM and Dettner, K and Kehl, S}, title = {Characterization of an obligate intracellular bacterium in the midgut epithelium of the bulrush bug Chilacis typhae (Heteroptera, Lygaeidae, Artheneinae).}, journal = {Applied and environmental microbiology}, volume = {77}, number = {9}, pages = {2869-2876}, pmid = {21378044}, issn = {1098-5336}, mesh = {Animals ; Chaperonin 60/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Epithelial Cells/*microbiology ; Epithelium/*microbiology ; Gammaproteobacteria/*classification/genetics/*isolation &amp; purification/physiology ; Gastrointestinal Tract/microbiology ; Heteroptera/*microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Nymph/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Many members of the suborder Heteroptera have symbiotic bacteria, which are usually found extracellularly in specific sacs or tubular outgrowths of the midgut or intracellularly in mycetomes. In this study, we describe the second molecular characterization of a symbiotic bacterium in a monophagous, seed-sucking stink bug of the family Lygaeidae (sensu stricto). Chilacis typhae possesses at the end of the first section of the midgut a structure which is composed of circularly arranged, strongly enlarged midgut epithelial cells. It is filled with an intracellular endosymbiont. This "mycetocytic belt" might represent an evolutionarily intermediate stage of the usual symbiotic structures found in stink bugs. Phylogenetic analysis based on the 16S rRNA and the groEL genes showed that the bacterium belongs to the Gammaproteobacteria, and it revealed a phylogenetic relationship with a secondary bacterial endosymbiont of Cimex lectularius and free-living plant pathogens such as Pectobacterium and Dickeya. The distribution and ultrastructure of the rod-shaped Chilacis endosymbiont were studied in adults and nymph stages using fluorescence in situ hybridization (FISH) and electron microscopy. The detection of symbionts at the anterior poles of developing eggs indicates that endosymbionts are transmitted vertically. A new genus and species name, "Candidatus Rohrkolberia cinguli," is proposed for this newly characterized clade of symbiotic bacteria.}, }
@article {pmid21376623, year = {2011}, author = {Ifuku, K and Ido, K and Sato, F}, title = {Molecular functions of PsbP and PsbQ proteins in the photosystem II supercomplex.}, journal = {Journal of photochemistry and photobiology. B, Biology}, volume = {104}, number = {1-2}, pages = {158-164}, doi = {10.1016/j.jphotobiol.2011.02.006}, pmid = {21376623}, issn = {1873-2682}, mesh = {Chlorophyta/enzymology ; Cyanobacteria/enzymology ; Metals/chemistry ; Photosystem II Protein Complex/chemistry/metabolism/*physiology ; Plant Proteins/*chemistry/metabolism/physiology ; Protein Binding ; Protein Subunits/chemistry/metabolism/physiology ; }, abstract = {The PsbP and PsbQ proteins are extrinsic subunits of the photosystem II (PSII) supercomplex, which are found in green plants including higher plants and green algae. These proteins are thought to have evolved from their cyanobacterial homologs; cyanoP and cyanoQ respectively. It has been suggested that the functions of PsbP and PsbQ have largely changed from those of cyanoP and cyanoQ. In addition, multiple isoforms and homologs of PsbP and PsbQ were found in green plants, indicating that the acquisition of PsbP and PsbQ in PSII is not a direct path but a result of intensive functional divergence during evolution from cyanobacterial endosymbiont to chloroplast. In this review, we highlight newly introduced topics related to the functions and structures of both PsbP and PsbQ proteins. The present data suggest that PsbP together with PsbQ have specific and important roles in coordinating the activity of the donor and acceptor sides of PSII and stabilizing the active form of the PSII-light-harvesting complex II (LHCII) supercomplex.}, }
@article {pmid21350635, year = {2011}, author = {Pérez-Brocal, V and Gil, R and Moya, A and Latorre, A}, title = {New Insights on the Evolutionary History of Aphids and Their Primary Endosymbiont Buchnera aphidicola.}, journal = {International journal of evolutionary biology}, volume = {2011}, number = {}, pages = {250154}, pmid = {21350635}, issn = {2090-052X}, abstract = {Since the establishment of the symbiosis between the ancestor of modern aphids and their primary endosymbiont, Buchnera aphidicola, insects and bacteria have coevolved. Due to this parallel evolution, the analysis of bacterial genomic features constitutes a useful tool to understand their evolutionary history. Here we report, based on data from B. aphidicola, the molecular evolutionary analysis, the phylogenetic relationships among lineages and a comparison of sequence evolutionary rates of symbionts of four aphid species from three subfamilies. Our results support previous hypotheses of divergence of B. aphidicola and their host lineages during the early Cretaceous and indicate a closer relationship between subfamilies Eriosomatinae and Lachninae than with the Aphidinae. They also reveal a general evolutionary pattern among strains at the functional level. We also point out the effect of lifecycle and generation time as a possible explanation for the accelerated rate in B. aphidicola from the Lachninae.}, }
@article {pmid21350051, year = {2011}, author = {Foster, J and Slatko, B and Bandi, C and Kumar, S}, title = {Recombination in wolbachia endosymbionts of filarial nematodes?.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {5}, pages = {1921-1922}, pmid = {21350051}, issn = {1098-5336}, mesh = {Animals ; DNA, Bacterial/*genetics ; Filarioidea/*microbiology ; *Recombination, Genetic ; Sequence Alignment ; Symbiosis ; Wolbachia/*genetics/physiology ; }, }
@article {pmid21349981, year = {2011}, author = {Warnecke, T and Rocha, EP}, title = {Function-specific accelerations in rates of sequence evolution suggest predictable epistatic responses to reduced effective population size.}, journal = {Molecular biology and evolution}, volume = {28}, number = {8}, pages = {2339-2349}, doi = {10.1093/molbev/msr054}, pmid = {21349981}, issn = {1537-1719}, support = {//Medical Research Council/United Kingdom ; }, mesh = {Algorithms ; Bacteria/*genetics/metabolism ; Base Composition/genetics ; *Epistasis, Genetic ; *Evolution, Molecular ; Genes, Bacterial/genetics ; Genome, Bacterial/*genetics ; Models, Genetic ; Mutation/genetics ; Population Density ; }, abstract = {Changes in effective population size impinge on patterns of molecular evolution. Notably, slightly deleterious mutations are more likely to drift to fixation in smaller populations, which should typically also lead to an overall acceleration in the rates of evolution. This prediction has been validated empirically for several endosymbiont and island taxa. Here, we first show that rate accelerations are also evident in bacterial pathogens whose recent shifts in virulence make them prime candidates for reduced effective population size: Bacillus anthracis, Bordetella parapertussis, Mycobacterium leprae, Salmonella enterica typhi, Shigella spp., and Yersinia pestis. Using closely related genomes to analyze substitution rate dynamics across six phylogenetically independent bacterial clades, we demonstrate that relative rates of coding sequence evolution are biased according to gene functional category. Notably, genes that buffer against slightly deleterious mutations, such as chaperones, experience stronger rate accelerations than other functional classes at both nonsynonymous and synonymous sites. Although theory predicts altered evolutionary dynamics for buffer loci in the face of accumulating deleterious mutations, to observe even stronger rate accelerations is surprising. We suggest that buffer loci experience elevated substitution rates because the accumulation of deleterious mutations in the remainder of the genome favors compensatory substitutions in trans. Critically, the hyper-acceleration is evident across phylogenetically independent clades, supporting the hypothesis that reductions in effective population size predictably induce epistatic responses in genes that buffer against slightly deleterious mutations.}, }
@article {pmid21349119, year = {2011}, author = {Nakamura, Y and Gotoh, T and Imanishi, S and Mita, K and Kurtti, TJ and Noda, H}, title = {Differentially expressed genes in silkworm cell cultures in response to infection by Wolbachia and Cardinium endosymbionts.}, journal = {Insect molecular biology}, volume = {20}, number = {3}, pages = {279-289}, doi = {10.1111/j.1365-2583.2010.01056.x}, pmid = {21349119}, issn = {1365-2583}, mesh = {Animals ; Antimicrobial Cationic Peptides/genetics ; *Bacteroidetes ; Bombyx/genetics/*immunology/*microbiology ; Cells, Cultured ; Cytoplasm/immunology/microbiology ; *Gene Expression Regulation ; Immunity/*genetics ; Oligonucleotide Array Sequence Analysis ; Symbiosis/genetics/*immunology ; *Wolbachia ; }, abstract = {Wolbachia and Cardinium are bacterial endosymbionts that are widely distributed amongst arthropods. Both cause reproductive alterations, such as cytoplasmic incompatibility, parthenogenesis and feminization. Here we studied differentially expressed genes in Wolbachia- and Cardinium-infected Bm-aff3 silkworm cells using a silkworm microarray. Wolbachia infection did not alter gene expression or induce or suppress immune responses. In contrast, Cardinium infection induced many immune-related genes, including antimicrobial peptides, pattern recognition receptors and a serine protease. Host immune responses differed, possibly because of the different cell wall structures of Wolbachia and Cardinium because the former lacks genes encoding lipopolysaccharide components and two racemases for peptidoglycan formation. A few possibly non-immune-related genes were differentially expressed, but their involvement in host reproductive alteration was unclear.}, }
@article {pmid21349091, year = {2011}, author = {Steinert, S and Levashina, EA}, title = {Intracellular immune responses of dipteran insects.}, journal = {Immunological reviews}, volume = {240}, number = {1}, pages = {129-140}, doi = {10.1111/j.1600-065X.2010.00985.x}, pmid = {21349091}, issn = {1600-065X}, mesh = {Animals ; Diptera/*immunology/microbiology/parasitology/virology ; *Immunity, Innate ; }, abstract = {Vector-borne diseases, transmitted by bloodsucking arthropods, pose worldwide socio-medical and economical problems. Some of the major human infectious diseases, such as malaria, Dengue fever, and yellow fever, are transmitted by mosquitoes. While the majority of pathogens enjoy extracellular life styles in insects, viruses and some endosymbionts are strictly intracellular. Here, we summarize our knowledge on defense reactions against intracellular microorganisms in dipteran insects and discuss the potential of insects as models to study human pathogens.}, }
@article {pmid21348883, year = {2011}, author = {Crépeau, V and Cambon Bonavita, MA and Lesongeur, F and Randrianalivelo, H and Sarradin, PM and Sarrazin, J and Godfroy, A}, title = {Diversity and function in microbial mats from the Lucky Strike hydrothermal vent field.}, journal = {FEMS microbiology ecology}, volume = {76}, number = {3}, pages = {524-540}, doi = {10.1111/j.1574-6941.2011.01070.x}, pmid = {21348883}, issn = {1574-6941}, mesh = {Animals ; Archaea/classification/*genetics/metabolism ; Bacteria/classification/*genetics/metabolism ; *Biodiversity ; Carbon/metabolism ; DNA, Archaeal/genetics ; DNA, Bacterial/genetics ; Gene Library ; Methane/metabolism ; *Microbial Consortia ; Mytilidae/microbiology ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sulfur/metabolism ; Symbiosis ; }, abstract = {Diversity and function in microbial mats from the Lucky Strike hydrothermal vent field (Mid-Atlantic Ridge) were investigated using molecular approaches. DNA and RNA were extracted from mat samples overlaying hydrothermal deposits and Bathymodiolus azoricus mussel assemblages. We constructed and analyzed libraries of 16S rRNA gene sequences and sequences of functional genes involved in autotrophic carbon fixation [forms I and II RuBisCO (cbbL/M), ATP-citrate lyase B (aclB)]; methane oxidation [particulate methane monooxygenase (pmoA)] and sulfur oxidation [adenosine-5'-phosphosulfate reductase (aprA) and soxB]. To gain new insights into the relationships between mats and mussels, we also used new domain-specific 16S rRNA gene primers targeting Bathymodiolus sp. symbionts. All identified archaeal sequences were affiliated with a single group: the marine group 1 Thaumarchaeota. In contrast, analyses of bacterial sequences revealed much higher diversity, although two phyla Proteobacteria and Bacteroidetes were largely dominant. The 16S rRNA gene sequence library revealed that species affiliated to Beggiatoa Gammaproteobacteria were the dominant active population. Analyses of DNA and RNA functional gene libraries revealed a diverse and active chemolithoautotrophic population. Most of these sequences were affiliated with Gammaproteobacteria, including hydrothermal fauna symbionts, Thiotrichales and Methylococcales. PCR and reverse transcription-PCR using 16S rRNA gene primers targeted to Bathymodiolus sp. symbionts revealed sequences affiliated with both methanotrophic and thiotrophic endosymbionts.}, }
@article {pmid21336565, year = {2011}, author = {Degnan, PH and Bittleston, LS and Hansen, AK and Sabree, ZL and Moran, NA and Almeida, RP}, title = {Origin and examination of a leafhopper facultative endosymbiont.}, journal = {Current microbiology}, volume = {62}, number = {5}, pages = {1565-1572}, pmid = {21336565}, issn = {1432-0991}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Bacterial Physiological Phenomena ; Evolution, Molecular ; Genome, Bacterial ; Hemiptera/*microbiology/*physiology ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; }, abstract = {Eukaryotes engage in intimate interactions with microbes that range in age and type of association. Although many conspicuous examples of ancient insect associates are studied (e.g., Buchnera aphidicola), fewer examples of younger associations are known. Here, we further characterize a recently evolved bacterial endosymbiont of the leafhopper Euscelidius variegatus (Hemiptera, Cicadellidae), called BEV. We found that BEV, continuously maintained in E. variegatus hosts at UC Berkeley since 1984, is vertically transmitted with high fidelity. Unlike many vertically transmitted, ancient endosymbioses, the BEV-E. variegatus association is not obligate for either partner, and BEV can be cultivated axenically. Sufficient BEV colonies were grown and harvested to estimate its genome size and provide a partial survey of the genome sequence. The BEV chromosome is about 3.8 Mbp, and there is evidence for an extrachromosomal element roughly 53 kb in size (e.g., prophage or plasmid). We sequenced 438 kb of unique short-insert clones, representing about 12% of the BEV genome. Nearly half of the gene fragments were similar to mobile DNA, including 15 distinct types of insertion sequences (IS). Analyses revealed that BEV not only shares virulence genes with plant pathogens, but also is closely related to the plant pathogenic genera Dickeya, Pectobacterium, and Brenneria. However, the slightly reduced genome size, abundance of mobile DNA, fastidious growth in culture, and efficient vertical transmission suggest that symbiosis with E. variegatus has had a significant impact on genome evolution in BEV.}, }
@article {pmid21334706, year = {2011}, author = {Dallai, R and Mercati, D and Giusti, F and Gottardo, M and Carapelli, A}, title = {A Cardinium-like symbiont in the proturan Acerella muscorum (Hexapoda).}, journal = {Tissue &amp; cell}, volume = {43}, number = {3}, pages = {151-156}, doi = {10.1016/j.tice.2011.01.004}, pmid = {21334706}, issn = {1532-3072}, mesh = {Animals ; Arthropods/*microbiology ; Bacteroidetes/*isolation &amp; purification/ultrastructure ; Male ; Microscopy, Electron, Transmission ; Spermatozoa/microbiology/ultrastructure ; *Symbiosis ; Testis/microbiology/ultrastructure ; }, abstract = {Endosymbionts of the Cardinium-like genus are described in the testes and other tissues of the proturan Acerella muscorum (Ionescu). Few endosymbionts are present in the large apical cells of functional testes, but they become numerous at the end of the reproductive cycle. They are also found within sperm cells where induce their degeneration. The Gram-negative endosymbionts are characterized by the presence of microtubule-like structures (MLC) in their cytoplasm. It is suggested a possible role of the endosymbionts in the elimination of degenerating sperm cells when the testes activity is ended, thus somewhat playing a role in the timing of the reproductive cycle of the proturan species.}, }
@article {pmid21334091, year = {2011}, author = {Dunning Hotopp, JC}, title = {Horizontal gene transfer between bacteria and animals.}, journal = {Trends in genetics : TIG}, volume = {27}, number = {4}, pages = {157-163}, pmid = {21334091}, issn = {0168-9525}, support = {DP2 OD007372/OD/NIH HHS/United States ; DP2 OD007372-01/OD/NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics ; Biological Evolution ; *Gene Transfer, Horizontal ; Genome ; Humans ; }, abstract = {Horizontal gene transfer is increasingly described between bacteria and animals. Such transfers that are vertically inherited have the potential to influence the evolution of animals. One classic example is the transfer of DNA from mitochondria and chloroplasts to the nucleus after the acquisition of these organelles by eukaryotes. Even today, many of the described instances of bacteria-to-animal transfer occur as part of intimate relationships such as those of endosymbionts and their invertebrate hosts, particularly insects and nematodes, while numerous transfers are also found in asexual animals. Both of these observations are consistent with modern evolutionary theory, in particular the serial endosymbiotic theory and Muller's ratchet. Although it is tempting to suggest that these particular lifestyles promote horizontal gene transfer, it is difficult to ascertain given the nonrandom sampling of animal genome sequencing projects and the lack of a systematic analysis of animal genomes for such transfers.}, }
@article {pmid21333023, year = {2011}, author = {Gross, J and Bhattacharya, D}, title = {Endosymbiont or host: who drove mitochondrial and plastid evolution?.}, journal = {Biology direct}, volume = {6}, number = {}, pages = {12}, pmid = {21333023}, issn = {1745-6150}, mesh = {*Biological Evolution ; Genome/genetics ; Mitochondria/*genetics ; Models, Biological ; Plastids/*genetics ; Prokaryotic Cells/metabolism ; *Symbiosis ; }, abstract = {The recognition that mitochondria and plastids are derived from alphaproteobacterial and cyanobacterial endosymbionts, respectively, was one of the greatest advances in modern evolutionary biology. Researchers have yet however to provide detailed cell biological descriptions of how these once free-living prokaryotes were transformed into intracellular organelles. A key area of study in this realm is elucidating the evolution of the molecular machines that control organelle protein topogenesis. Alcock et al. (Science 2010, 327 [5966]:649-650) suggest that evolutionary innovations that established the mitochondrial protein sorting system were driven by the alphaproteobacterial endosymbiont (an "insiders' perspective"). In contrast, here we argue that evolution of mitochondrial and plastid topogenesis may better be understood as an outcome of selective pressures acting on host cell chromosomes (the "outsiders' view").}, }
@article {pmid21329550, year = {2011}, author = {Chu, D and Gao, CS and De Barro, P and Zhang, YJ and Wan, FH and Khan, IA}, title = {Further insights into the strange role of bacterial endosymbionts in whitefly, Bemisia tabaci: comparison of secondary symbionts from biotypes B and Q in China.}, journal = {Bulletin of entomological research}, volume = {101}, number = {4}, pages = {477-486}, doi = {10.1017/S0007485311000083}, pmid = {21329550}, issn = {1475-2670}, mesh = {Animals ; Bacterial Typing Techniques ; China ; Hemiptera/*microbiology ; Introduced Species ; Mediterranean Region ; Rickettsia/classification/isolation &amp; purification ; *Symbiosis ; Wolbachia/classification/isolation &amp; purification ; }, abstract = {The percentage infection of secondary symbionts (SS) (Wolbachia, Arsenophonus, Rickettsia, Hamiltonella, Fritschea and Cardinium) in the exotic Bemisia tabaci (Genn.) invaders, commonly known as biotypes B and Q from China, were determined by PCR. In total, 373 biotype B and 1830 biotype Q individuals were screened for the presence of SS. Biotype B was more abundant than biotype Q from 2005 to 2006, and biotype Q was more abundant from 2007 to 2009. Each of the SS, with the exception of Fritschea, was detected in both biotypes B and Q; Fritschea was found in none of the samples examined. For biotype B, the percentage infection of Hamiltonella was the highest (92.0%) followed by Rickettsia (70.2%). For biotype Q, the percentage infection of Hamiltonella was again the highest (73.3%). Arsenophonus was the least common of the SS observed in both biotypes B and Q. The percentage infection of Wolbachia, Rickettsia and Hamiltonella in biotype B was each significantly higher than in biotype Q, whereas the percentage infection of Cardinium in biotype B was significantly lower than in biotype Q. The percentage infection of SS in biotypes B and Q varied from year to year over the period 2005-2009. Furthermore, within biotype Q, two distinct subgroups were identified which differ from each other in terms of their SS complement. We discuss these results in the light of the potentially influential factors and roles of the SS.}, }
@article {pmid21327558, year = {2011}, author = {Nachappa, P and Levy, J and Pierson, E and Tamborindeguy, C}, title = {Diversity of endosymbionts in the potato psyllid, Bactericera cockerelli (Triozidae), vector of zebra chip disease of potato.}, journal = {Current microbiology}, volume = {62}, number = {5}, pages = {1510-1520}, pmid = {21327558}, issn = {1432-0991}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; *Biodiversity ; Female ; Hemiptera/*microbiology/physiology ; Insect Vectors/*microbiology ; Male ; Molecular Sequence Data ; Phylogeny ; Plant Diseases/*microbiology ; Rhizobiaceae/classification/genetics/isolation &amp; purification/physiology ; Solanum tuberosum/*microbiology/parasitology ; *Symbiosis ; }, abstract = {Zebra chip disease is an emerging, serious disease of solanaceous crops and the causal agent is a bacterium "Candidatus Liberibacter solanacearum" (CLs), also known as "Candidatus Liberibacter psyllaurous", which is transmitted by the potato psyllid, Bactericera cockerelli (Šulc). We performed bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP) of the 16S rDNA genes to determine the bacterial microbiota in adult insects from CLs-uninfected and CLs-infected strains of B. cockerelli and potato leaf samples. We obtained sequences from five bacterial species among the two psyllid strains, including "Candidatus Carsonella ruddii", Wolbachia, CLs, and two transient bacteria, Acinetobacter and Methylibium. We did not detect any common bacteria between psyllids and potato leaf samples using pyrosequencing. We performed PCR analysis using species-specific 16S rDNA primers to confirm pyrosequencing results in individual psyllids including eggs, early-instars, late-instars, and adults of both sexes from both CLs-uninfected and CLs-infected psyllid strains. The primary endosymbiont, "Candidatus Carsonella ruddii" and Wolbachia were detected in all life-stages and sexes of both strains using PCR analyses. The percentage of CLs-infected individuals increased from early-instar (0%), late-instar (40%) until adulthood (60%) in the CLs-infected strain. We believe that CLs levels in early-instars are probably too low to be detected by standard PCR. Using PCR analyses, we confirmed the presence of Acinetobacter in CLs-uninfected and CLs-infected adults (75 and 25%, respectively) but not Methylibium. Further, we detected Acinetobacter in potato leaves using PCR indicating that the psyllids may have acquired this bacterium via feeding on the host plant.}, }
@article {pmid21324604, year = {2011}, author = {Li, Z and Galvin, BD and Raverdy, S and Carlow, CK}, title = {Identification and characterization of the cofactor-independent phosphoglycerate mutases of Dirofilaria immitis and its Wolbachia endosymbiont.}, journal = {Veterinary parasitology}, volume = {176}, number = {4}, pages = {350-356}, doi = {10.1016/j.vetpar.2011.01.020}, pmid = {21324604}, issn = {1873-2550}, support = {AI061865/AI/NIAID NIH HHS/United States ; }, mesh = {2,3-Diphosphoglycerate/metabolism ; Amino Acid Sequence ; Animals ; Bacterial Proteins/genetics/isolation &amp; purification/metabolism ; Cloning, Molecular ; DNA, Complementary/chemistry/isolation &amp; purification ; Dirofilaria immitis/*enzymology/genetics/microbiology ; Female ; Gene Expression ; Glyceric Acids/metabolism ; Helminth Proteins/genetics/isolation &amp; purification/metabolism ; Molecular Sequence Data ; Phosphoglycerate Mutase/chemistry/genetics/isolation &amp; purification/*metabolism ; Phylogeny ; Recombinant Proteins/genetics/isolation &amp; purification/metabolism ; Sequence Alignment ; Symbiosis ; Wolbachia/*enzymology/genetics/physiology ; }, abstract = {Drug treatments for heartworm disease have not changed significantly in the last decade. Due to concerns about possible drug resistance and their lower efficacy against adult worms, there is a need for the development of new antifilarial drug therapies. The recent availability of genomic sequences for the related filarial parasite Brugia malayi and its Wolbachia endosymbiont enables genome-wide searching for new drug targets. Phosphoglycerate mutase (PGM) enzymes catalyze the critical isomerization of 3-phosphoglycerate (3-PG) and 2-phosphoglycerate (2-PG) in glycolytic and gluconeogenic metabolic pathways. There are two unrelated PGM enzymes, which are structurally distinct and possess different mechanisms of action. The mammalian enzyme requires 2,3-bisphosphoglycerate as a cofactor (dependent PGM or dPGM), while the other type of PGM does not (independent PGM or iPGM). In the present study, we have determined that Dirofilaria immitis and its Wolbachia endosymbiont both possess active iPGM. We describe the molecular characterization and catalytic properties of each enzyme. Our results will facilitate the discovery of selective inhibitors of these iPGMs as potentially novel drug treatments for heartworm disease.}, }
@article {pmid21305008, year = {2011}, author = {Álvarez-Loayza, P and White, JF and Torres, MS and Balslev, H and Kristiansen, T and Svenning, JC and Gil, N}, title = {Light converts endosymbiotic fungus to pathogen, influencing seedling survival and niche-space filling of a common tropical tree, Iriartea deltoidea.}, journal = {PloS one}, volume = {6}, number = {1}, pages = {e16386}, pmid = {21305008}, issn = {1932-6203}, mesh = {Arecaceae/growth &amp; development/*microbiology ; Biodiversity ; *Ecosystem ; Fungi/*radiation effects ; *Light ; Seedlings/growth &amp; development/*microbiology ; Symbiosis/*radiation effects ; Tropical Climate ; }, abstract = {Pathogens are hypothesized to play an important role in the maintenance of tropical forest plant species richness. Notably, species richness may be promoted by incomplete filling of niche space due interactions of host populations with their pathogens. A potentially important group of pathogens are endophytic fungi, which asymptomatically colonize plants and are diverse and abundant in tropical ecosystems. Endophytes may alter competitive abilities of host individuals and improve host fitness under stress, but may also become pathogenic. Little is known of the impacts of endophytes on niche-space filling of their hosts.Here we evaluate how a widespread fungal endophyte infecting a common tropical palm influences its recruitment and survival in natural ecosystems, and whether this impact is modulated by the abiotic environment, potentially constraining host niche-space filling. Iriartea deltoidea dominates many wet lowland Neotropical forests. Diplodia mutila is a common asymptomatic endophyte in mature plants; however, it causes disease in some seedlings. We investigated the effects of light availability on D. mutila disease expression.We found I. deltoidea seedlings to preferentially occur under shady conditions. Correspondingly, we also found that high light triggers endophyte pathogenicity, while low light favors endosymbiotic development, constraining recruitment of endophyte-infested seedlings to shaded understory by reducing seedling survival in direct light. Pathogenicity of D. mutila under high light is proposed to result from light-induced production of H(2)O(2) by the fungus, triggering hypersensitivity, cell death, and tissue necrosis in the palm. This is the first study to demonstrate that endophytes respond to abiotic factors to influence plant distributions in natural ecosystems; and the first to identify light as a factor influencing where an endophyte is placed on the endosymbiont-pathogen continuum. Our findings show that pathogens can indeed constrain niche-space filling of otherwise successful tropical plant species, providing unoccupied niche space for other species.}, }
@article {pmid21304746, year = {2010}, author = {Roeselers, G and Newton, IL and Woyke, T and Auchtung, TA and Dilly, GF and Dutton, RJ and Fisher, MC and Fontanez, KM and Lau, E and Stewart, FJ and Richardson, PM and Barry, KW and Saunders, E and Detter, JC and Wu, D and Eisen, JA and Cavanaugh, CM}, title = {Complete genome sequence of Candidatus Ruthia magnifica.}, journal = {Standards in genomic sciences}, volume = {3}, number = {2}, pages = {163-173}, pmid = {21304746}, issn = {1944-3277}, abstract = {The hydrothermal vent clam Calyptogena magnifica (Bivalvia: Mollusca) is a member of the Vesicomyidae. Species within this family form symbioses with chemosynthetic Gammaproteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a rudimentary gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. The C. magnifica symbiont, Candidatus Ruthia magnifica, was the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced (Newton et al. 2007). Here we expand upon the original report and provide additional details complying with the emerging MIGS/MIMS standards. The complete genome exposed the genetic blueprint of the metabolic capabilities of the symbiont. Genes which were predicted to encode the proteins required for all the metabolic pathways typical of free-living chemoautotrophs were detected in the symbiont genome. These include major pathways including carbon fixation, sulfur oxidation, nitrogen assimilation, as well as amino acid and cofactor/vitamin biosynthesis. This genome sequence is invaluable in the study of these enigmatic associations and provides insights into the origin and evolution of autotrophic endosymbiosis.}, }
@article {pmid21292630, year = {2011}, author = {Kent, BN and Salichos, L and Gibbons, JG and Rokas, A and Newton, IL and Clark, ME and Bordenstein, SR}, title = {Complete bacteriophage transfer in a bacterial endosymbiont (Wolbachia) determined by targeted genome capture.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {209-218}, pmid = {21292630}, issn = {1759-6653}, support = {F31 AI091343/AI/NIAID NIH HHS/United States ; R01 GM085163/GM/NIGMS NIH HHS/United States ; R24 GM084917/GM/NIGMS NIH HHS/United States ; R01 GM085163-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacteriophages/*genetics/physiology ; *Gene Transfer, Horizontal ; *Genome, Bacterial ; Symbiosis ; Wolbachia/*genetics/physiology/*virology ; }, abstract = {Bacteriophage flux can cause the majority of genetic diversity in free-living bacteria. This tenet of bacterial genome evolution generally does not extend to obligate intracellular bacteria owing to their reduced contact with other microbes and a predominance of gene deletion over gene transfer. However, recent studies suggest intracellular coinfections in the same host can facilitate exchange of mobile elements between obligate intracellular bacteria-a means by which these bacteria can partially mitigate the reductive forces of the intracellular lifestyle. To test whether bacteriophages transfer as single genes or larger regions between coinfections, we sequenced the genome of the obligate intracellular Wolbachia strain wVitB from the parasitic wasp Nasonia vitripennis and compared it against the prophage sequences of the divergent wVitA coinfection. We applied, for the first time, a targeted sequence capture array to specifically trap the symbiont's DNA from a heterogeneous mixture of eukaryotic, bacterial, and viral DNA. The tiled array successfully captured the genome with 98.3% efficiency. Examination of the genome sequence revealed the largest transfer of bacteriophage and flanking genes (52.2 kb) to date between two obligate intracellular coinfections. The mobile element transfer occurred in the recent evolutionary past based on the 99.9% average nucleotide identity of the phage sequences between the two strains. In addition to discovering an evolutionary recent and large-scale horizontal phage transfer between coinfecting obligate intracellular bacteria, we demonstrate that "targeted genome capture" can enrich target DNA to alleviate the problem of isolating symbiotic microbes that are difficult to culture or purify from the conglomerate of organisms inside eukaryotes.}, }
@article {pmid21290260, year = {2011}, author = {Tanaka, T and Fukuda, Y and Yoshino, T and Maeda, Y and Muto, M and Matsumoto, M and Mayama, S and Matsunaga, T}, title = {High-throughput pyrosequencing of the chloroplast genome of a highly neutral-lipid-producing marine pennate diatom, Fistulifera sp. strain JPCC DA0580.}, journal = {Photosynthesis research}, volume = {109}, number = {1-3}, pages = {223-229}, pmid = {21290260}, issn = {1573-5079}, mesh = {Aquatic Organisms/genetics ; Base Sequence ; Biological Evolution ; Chloroplasts/*genetics ; DNA/chemistry/genetics ; Diatoms/*genetics ; Gene Transfer, Horizontal ; Genome, Chloroplast/*genetics ; High-Throughput Nucleotide Sequencing ; Molecular Sequence Annotation ; Molecular Sequence Data ; Open Reading Frames/*genetics ; Photosystem II Protein Complex/genetics ; Sequence Analysis, DNA ; }, abstract = {The chloroplast genome of the highly neutral-lipid-producing marine pennate diatom Fistulifera sp. strain JPCC DA0580 was fully sequenced using high-throughput pyrosequencing. The general features and gene content were compared with three other complete diatom chloroplast genomes. The chloroplast genome is 134,918 bp with an inverted repeat of 13,330 bp and is slightly larger than the other diatom chloroplast genomes due to several low gene-density regions lacking similarity to the other diatom chloroplast genomes. Protein-coding genes were nearly identical to those from Phaeodactylum tricornutum. On the other hand, we found unique sequence variations in genes of photosystem II which differ from the consensus in other diatom chloroplasts. Furthermore, five functional unknown ORFs and a putative serine recombinase gene, serC2, are located in the low gene-density regions. SerC2 was also identified in the plasmids of another pennate diatom, Cylindrotheca fusiformis, and in the plastid genome of the diatom endosymbiont of Kryptoperidinium foliaceum. Exogenous plasmids might have been incorporated into the chloroplast genome of Fistulifera sp. by lateral gene transfer. Chloroplast genome sequencing analysis of this novel diatom provides many important insights into diatom evolution.}, }
@article {pmid21288878, year = {2011}, author = {Söderberg, RJ and Berg, OG}, title = {Kick-starting the ratchet: the fate of mutators in an asexual population.}, journal = {Genetics}, volume = {187}, number = {4}, pages = {1129-1137}, pmid = {21288878}, issn = {1943-2631}, mesh = {Alleles ; Animals ; Antimutagenic Agents/metabolism ; Aphids/microbiology ; *Biological Evolution ; Buchnera/genetics/growth &amp; development ; Genetic Loci ; *Genetics, Population ; Genome, Bacterial ; *Models, Genetic ; *Mutation ; Selection, Genetic ; }, abstract = {Muller's ratchet operates in asexual populations without intergenomic recombination. In this case, deleterious mutations will accumulate and population fitness will decline over time, possibly endangering the survival of the species. Mutator mutations, i.e., mutations that lead to an increased mutation rate, will play a special role for the behavior of the ratchet. First, they are part of the ratchet and can come to dominance through accumulation in the ratchet. Second, the fitness-loss rate of the ratchet is very sensitive to changes in the mutation rate and even a modest increase can easily set the ratchet in motion. In this article we simulate the interplay between fitness loss from Muller's ratchet and the evolution of the mutation rate from the fixation of mutator mutations. As long as the mutation rate is increased in sufficiently small steps, an accelerating ratchet and eventual extinction are inevitable. If this can be countered by antimutators, i.e., mutations that reduce the mutation rate, an equilibrium can be established for the mutation rate at some level that may allow survival. However, the presence of the ratchet amplifies fluctuations in the mutation rate and, even at equilibrium, these fluctuations can lead to dangerous bursts in the ratchet. We investigate the timescales of these processes and discuss the results with reference to the genome degradation of the aphid endosymbiont Buchnera aphidicola.}, }
@article {pmid21283625, year = {2011}, author = {Friberg, U and Miller, PM and Stewart, AD and Rice, WR}, title = {Mechanisms promoting the long-term persistence of a Wolbachia infection in a laboratory-adapted population of Drosophila melanogaster.}, journal = {PloS one}, volume = {6}, number = {1}, pages = {e16448}, pmid = {21283625}, issn = {1932-6203}, support = {R01 HD057974/HD/NICHD NIH HHS/United States ; 1R01HD057974-01/HD/NICHD NIH HHS/United States ; }, mesh = {Animals ; Clinical Laboratory Techniques ; Cytoplasm ; Drosophila melanogaster/*microbiology ; Female ; Host Specificity/*physiology ; Insecta/microbiology ; Male ; Phenotype ; Rickettsiaceae Infections ; Symbiosis/*physiology ; *Wolbachia ; }, abstract = {Intracellular bacteria of the genus Wolbachia are widespread endosymbionts across diverse insect taxa. Despite this prevalence, our understanding of how Wolbachia persists within populations is not well understood. Cytoplasmic incompatibility (CI) appears to be an important phenotype maintaining Wolbachia in many insects, but it is believed to be too weak to maintain Wolbachia in Drosophila melanogaster, suggesting that Wolbachia must also have other effects on this species. Here we estimate the net selective effect of Wolbachia on its host in a laboratory-adapted population of D. melanogaster, to determine the mechanisms leading to its persistence in the laboratory environment. We found i) no significant effects of Wolbachia infection on female egg-to-adult survival or adult fitness, ii) no reduced juvenile survival in males, iii) substantial levels of CI, and iv) a vertical transmission rate of Wolbachia higher than 99%. The fitness of cured females was, however, severely reduced (a decline of 37%) due to CI in offspring. Taken together these findings indicate that Wolbachia is maintained in our laboratory environment due to a combination of a nearly perfect transmission rate and substantial CI. Our results show that there would be strong selection against females losing their infection and producing progeny free from Wolbachia.}, }
@article {pmid21282658, year = {2011}, author = {Hansen, AK and Moran, NA}, title = {Aphid genome expression reveals host-symbiont cooperation in the production of amino acids.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {108}, number = {7}, pages = {2849-2854}, pmid = {21282658}, issn = {1091-6490}, mesh = {Amino Acids, Essential/*biosynthesis/genetics ; Animals ; Aphids/*genetics/metabolism/*microbiology ; Base Sequence ; Buchnera/*metabolism ; *Evolution, Molecular ; Gene Expression Regulation/*genetics ; Glutamate Synthase/metabolism ; Glutamate-Ammonia Ligase/metabolism ; Molecular Sequence Data ; Quaternary Ammonium Compounds/metabolism ; Sequence Analysis, RNA ; Species Specificity ; *Symbiosis ; }, abstract = {The evolution of intimate symbiosis requires the coordination of gene expression and content between the distinct partner genomes; this coordination allows the fusion of capabilities of each organism into a single integrated metabolism. In aphids, the 10 essential amino acids are scarce in the phloem sap diet and are supplied by the obligate bacterial endosymbiont (Buchnera), which lives inside specialized cells called bacteriocytes. Although Buchnera's genome encodes most genes for essential amino acid biosynthesis, several genes in essential amino acid pathways are missing, as are most genes for production of nonessential amino acids. Additionally, it is unresolved whether the supply of nitrogen for amino acid biosynthesis is supplemented by recycling of waste ammonia. We compared pea aphid gene expression between bacteriocytes and other body tissues using RNA sequencing and pathway analysis and exploiting the genome sequences available for both partners. We found that 26 genes underlying amino acid biosynthesis were up-regulated in bacteriocytes. Seven of these up-regulated genes fill the gaps of Buchnera's essential amino acid pathways. In addition, genes underlying five nonessential amino acid pathways lost from Buchnera are up-regulated in bacteriocytes. Finally, our results reveal that two genes, glutamine synthetase and glutamate synthase, which potentially work together in the incorporation of ammonium nitrogen into glutamate (GOGAT) cycle to assimilate ammonia into glutamate, are up-regulated in bacteriocytes. Thus, host gene expression and symbiont capabilities are closely integrated within bacteriocytes, which function as specialized organs of amino acid production. Furthermore, the GOGAT cycle may be a key source of nitrogen fueling the integrated amino acid metabolism of the aphid-Buchnera partnership.}, }
@article {pmid21268696, year = {2010}, author = {Hu, JS and Gelman, DB and Salvucci, ME and Chen, YP and Blackburn, MB}, title = {Insecticidal activity of some reducing sugars against the sweet potato whitefly, Bemisia tabaci, Biotype B.}, journal = {Journal of insect science (Online)}, volume = {10}, number = {}, pages = {203}, pmid = {21268696}, issn = {1536-2442}, mesh = {Animals ; Carbohydrates/*chemistry/*pharmacology ; Hemiptera/*drug effects ; Insecticides/chemistry/pharmacology ; Nymph/drug effects ; }, abstract = {The effects of 16 sugars (arabinose, cellobiose, fructose, galactose, gentiobiose, glucose, inositol, lactose, maltose, mannitol (a sugar alcohol), mannose, melibiose, ribose, sorbitol, trehalose, and xylose) on sweet potato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) survival were determined using in vitro bioassays. Of these sugars, arabinose, mannose, ribose, and xylose were strongly inhibitory to both nymphal and adult survival. When 10% mannose was added to the nymphal diet, 10.5%, 1.0%, and 0% developed to the 2nd, 3rd, and 4th instars, respectively. When 10% arabinose was added, 10.8% and 0% of the nymphs molted to the 2nd and 3rd instars, respectively. Addition of 10% xylose or ribose completely terminated B. tabaci development, preventing the molt to the 2(nd) instar. With decreasing sugar concentrations the inhibitory effect was significantly reduced. In tests using adults, arabinose, galactose, inositol, lactose, maltose, mannitol, mannose, melibiose, ribose, sorbitol, trehalose, and xylose significantly reduced mean day survival. Mortality rates were highest when arabinose, mannitol, mannose, ribose, or xylose was added to the diet. Mean day survival was less than 2 days when adults were fed on diet containing 10% of any one of these five sugars. When lower concentrations of sugars were used there was a decrease in mortality. Mode of action studies revealed that toxicity was not due to the inhibition of alpha glucosidase (converts sucrose to glucose and fructose) and/or trehalulose synthase (converts sucrose to trehalulose) activity. The result of agarose gel electrophoresis of RT-PCR products of bacterial endosymbionts amplified from RNA isolated from whiteflies fed with 10% arabinose, mannose, or xylose indicated that the concentration of endosymbionts in mycetomes was not affected by the toxic sugars. Experiments in which B. tabaci were fed on diets that contained radio-labeled sucrose, methionine or inulin and one or none (control) of the highly toxic sugars showed that radioactivity (expressed in DPM) in the body, in excreted honeydew and/or carbon dioxide, was significantly reduced as compared to controls. Thus, it appears that the ability of insecticidal sugars to act as antifeedants is responsible for their toxicity to B. tabaci.}, }
@article {pmid21255169, year = {2011}, author = {Hutchence, KJ and Fischer, B and Paterson, S and Hurst, GD}, title = {How do insects react to novel inherited symbionts? A microarray analysis of Drosophila melanogaster response to the presence of natural and introduced Spiroplasma.}, journal = {Molecular ecology}, volume = {20}, number = {5}, pages = {950-958}, doi = {10.1111/j.1365-294X.2010.04974.x}, pmid = {21255169}, issn = {1365-294X}, mesh = {Animals ; Drosophila melanogaster/genetics/*immunology/*microbiology ; Gene Expression Profiling ; Infectious Disease Transmission, Vertical ; Microarray Analysis ; Spiroplasma/*physiology ; Symbiosis/genetics/*immunology ; }, abstract = {Maternally inherited endosymbionts are found in numerous insect species and have various effects on host ecology. New symbioses are most commonly established following lateral transfer of an existing symbiont from one host species to another. Laboratory study has demonstrated that symbionts commonly perform poorly in novel hosts, with weak vertical transmission and maladaptive pathogenicity being observed in the generations following transfer. This poor performance probably limits symbiont occurrence. We here use microarray technology to test whether poor symbiont performance observed following 1 year of vertical transmission through a new host is associated with alteration in host gene expression or whether it occurs independently of this. We utilize the Drosophila melanogaster--Spiroplasma interaction and test the response of the host in the presence of both natural Spiroplasma infections and novel Spiroplasma infections transinfected previously from other host species. None of the Spiroplasma infections investigated produced upregulation in host haemolymph/fat body-based immune responses, and we therefore rejected the hypothesis that failure to thrive was associated with immune upregulation. One infection was associated with a downregulation of genes associated with egg production compared to uninfected controls, indicative of damage to the host. The Spiroplasma infection showed that the weakest vertical transmission showed no significant disturbance to host gene expression compared to uninfected controls. We conclude that the failure of Spiroplasma in novel host species is associated either with causing harm to their new hosts or through a failure to thrive in the new host that occurs independently of host responses to infection.}, }
@article {pmid21235755, year = {2011}, author = {Vanthournout, B and Swaegers, J and Hendrickx, F}, title = {Spiders do not escape reproductive manipulations by Wolbachia.}, journal = {BMC evolutionary biology}, volume = {11}, number = {}, pages = {15}, pmid = {21235755}, issn = {1471-2148}, mesh = {Animals ; Bacteroidetes/classification/genetics/physiology ; Female ; Male ; Molecular Sequence Data ; Phylogeny ; Reproduction ; Rickettsia/classification/genetics/physiology ; Species Specificity ; Spiders/*microbiology/*physiology ; Symbiosis ; Wolbachia/classification/genetics/*physiology ; }, abstract = {BACKGROUND: Maternally inherited bacteria that reside obligatorily or facultatively in arthropods can increase their prevalence in the population by altering their hosts' reproduction. Such reproductive manipulations have been reported from the major arthropod groups such as insects (in particular hymenopterans, butterflies, dipterans and beetles), crustaceans (isopods) and mites. Despite the observation that endosymbiont bacteria are frequently encountered in spiders and that the sex ratio of particular spider species is strongly female biased, a direct relationship between bacterial infection and sex ratio variation has not yet been demonstrated for this arthropod order.<br><br>RESULTS: Females of the dwarf spider Oedothorax gibbosus exhibit considerable variation in the sex ratio of their clutches and were infected with at least three different endosymbiont bacteria capable of altering host reproduction i.e. Wolbachia, Rickettsia and Cardinium. Breeding experiments show that sex ratio variation in this species is primarily maternally inherited and that removal of the bacteria by antibiotics restores an unbiased sex ratio. Moreover, clutches of females infected with Wolbachia were significantly female biased while uninfected females showed an even sex ratio. As female biased clutches were of significantly smaller size compared to non-distorted clutches, killing of male embryos appears to be the most likely manipulative effect.<br><br>CONCLUSIONS: This represents to our knowledge the first direct evidence that endosymbiont bacteria, and in particular Wolbachia, might induce sex ratio variation in spiders. These findings are pivotal to further understand the diversity of reproductive phenotypes observed in this arthropod order.}, }
@article {pmid21234752, year = {2011}, author = {Tabata, J and Hattori, Y and Sakamoto, H and Yukuhiro, F and Fujii, T and Kugimiya, S and Mochizuki, A and Ishikawa, Y and Kageyama, D}, title = {Male killing and incomplete inheritance of a novel spiroplasma in the moth Ostrinia zaguliaevi.}, journal = {Microbial ecology}, volume = {61}, number = {2}, pages = {254-263}, pmid = {21234752}, issn = {1432-184X}, mesh = {Animals ; Female ; Genes, Bacterial ; *Inheritance Patterns ; Male ; Moths/*microbiology ; Ovary/microbiology/ultrastructure ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Sex Ratio ; Spiroplasma/classification/genetics/*pathogenicity ; }, abstract = {Bacteria of the genus Spiroplasma are widely found in plants and arthropods. Some of the maternally transmitted Spiroplasma endosymbionts in arthropods are known to kill young male hosts (male killing). Here, we describe a new case of Spiroplasma-induced male killing in a moth, Ostrinia zaguliaevi. The all-female trait caused by Spiroplasma was maternally inherited for more than 11 generations but was spontaneously lost in several lineages. Antibiotic treatment eliminated the Spiroplasma infection and restored the 1:1 sex ratio. The survival rates and presence/absence of the W chromosome in the embryonic and larval stages of O. zaguliaevi showed that males were selectively killed, exclusively during late embryogenesis in all-female broods. Based on phylogenetic analyses of 16S rRNA, dnaA and rpoB gene sequences, the causative bacteria were identified as Spiroplasma belonging to the tick symbiont Spiroplasma ixodetis clade. Electron microscopy confirmed bacterial structures in the follicle cells and follicular sheath of adult females. Although many congeneric Ostrinia moths harbor another sex ratio-distorting bacterium (Wolbachia), only O. zaguliaevi harbors Spiroplasma.}, }
@article {pmid21225190, year = {2010}, author = {Popovici, J and Moreira, LA and Poinsignon, A and Iturbe-Ormaetxe, I and McNaughton, D and O'Neill, SL}, title = {Assessing key safety concerns of a Wolbachia-based strategy to control dengue transmission by Aedes mosquitoes.}, journal = {Memorias do Instituto Oswaldo Cruz}, volume = {105}, number = {8}, pages = {957-964}, doi = {10.1590/s0074-02762010000800002}, pmid = {21225190}, issn = {1678-8060}, mesh = {Aedes/*microbiology ; Animals ; Dengue/prevention &amp; control/transmission ; Dengue Virus/physiology ; Host-Parasite Interactions/*physiology ; Humans ; Insect Vectors/*microbiology ; Pest Control, Biological/*methods ; Symbiosis/physiology ; Wolbachia/*physiology ; }, abstract = {Mosquito-borne diseases such as dengue fever, chikungunya or malaria affect millions of people each year and control solutions are urgently needed. An international research program is currently being developed that relies on the introduction of the bacterial endosymbiont Wolbachia pipientis into Aedes aegypti to control dengue transmission. In order to prepare for open-field testing releases of Wolbachia-infected mosquitoes, an intensive social research and community engagement program was undertaken in Cairns, Northern Australia. The most common concern expressed by the diverse range of community members and stakeholders surveyed was the necessity of assuring the safety of the proposed approach for humans, animals and the environment. To address these concerns a series of safety experiments were undertaken. We report in this paper on the experimental data obtained, discuss the limitations of experimental risk assessment and focus on the necessity of including community concerns in scientific research.}, }
@article {pmid21216910, year = {2011}, author = {Pontes, MH and Dale, C}, title = {Lambda red-mediated genetic modification of the insect endosymbiont Sodalis glossinidius.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {5}, pages = {1918-1920}, pmid = {21216910}, issn = {1098-5336}, mesh = {Animals ; Bacteriophage lambda/*enzymology ; DNA, Bacterial/*genetics ; Enterobacteriaceae/*genetics ; Genetic Engineering/methods ; Genetics, Microbial/*methods ; Insecta/microbiology ; *Recombination, Genetic ; Viral Proteins/*metabolism ; }, abstract = {In the current study, we adapted and optimized the lambda Red recombineering strategy to genetically manipulate the fastidious insect endosymbiont Sodalis glossinidius. This work greatly facilitates the application of genetics to the study of insect symbionts and should also prove useful in the context of long-awaited paratransgenic insect control strategies.}, }
@article {pmid21199036, year = {2011}, author = {Toju, H and Fukatsu, T}, title = {Diversity and infection prevalence of endosymbionts in natural populations of the chestnut weevil: relevance of local climate and host plants.}, journal = {Molecular ecology}, volume = {20}, number = {4}, pages = {853-868}, doi = {10.1111/j.1365-294X.2010.04980.x}, pmid = {21199036}, issn = {1365-294X}, mesh = {Adaptation, Biological ; Animals ; *Climate ; DNA, Bacterial/genetics ; Geography ; Hippocastanaceae ; Japan ; Phylogeny ; Quercus ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/physiology ; Sequence Analysis, DNA ; Spiroplasma/*classification/physiology ; *Symbiosis ; Weevils/*microbiology ; Wolbachia/*classification/physiology ; }, abstract = {Many insects are ubiquitously associated with multiple endosymbionts, whose infection patterns often exhibit spatial and temporal variations. How such endosymbiont variations are relevant to local adaptation of the host organisms is of ecological interest. Here, we report a comprehensive survey of endosymbionts in natural populations of the chestnut weevil Curculio sikkimensis, whose larvae are notorious pests of cultivated chestnuts and also infest acorns of various wild oaks. From 968 insects representing 55 localities across the Japanese Archipelago and originating from 10 host plant species, we identified six distinct endosymbiont lineages, namely Curculioniphilus, Sodalis, Serratia, Wolbachia, Rickettsia and Spiroplasma, at different infection frequencies (96.7%, 12.8%, 82.3%, 82.5%, 28.2% and 6.8%, respectively) and with different geographical distribution patterns. Multiple endosymbiont infections were very common; 3.18±0.61 (ranging from 1.74 to 5.50) endosymbionts per insect on average in each of the local populations. Five pairs of endosymbionts (Curculioniphilus-Serratia, Curculioniphilus-Wolbachia, Sodalis-Rickettsia, Wolbachia-Rickettsia and Rickettsia-Spiroplasma) co-infected the same host individuals more frequently than expected, while infections with Serratia and Wolbachia were negatively correlated to each other. Infection frequencies of the endosymbionts were significantly correlated with climatic and ecological factors: for example, higher Sodalis, Wolbachia and Rickettsia infections at localities of higher temperature; lower Wolbachia and Rickettsia infections at localities of greater snowfall; and higher Curculioniphilus, Sodalis, Serratia, Wolbachia and Rickettsia infections on acorns than on chestnuts. These patterns are discussed in relation to potential host-endosymbiont co-evolution via local adaptation across geographical populations.}, }
@article {pmid22654845, year = {2011}, author = {Negri, I}, title = {Wolbachia as an "infectious" extrinsic factor manipulating host signaling pathways.}, journal = {Frontiers in endocrinology}, volume = {2}, number = {}, pages = {115}, pmid = {22654845}, issn = {1664-2392}, abstract = {Wolbachia pipientis is a widespread endosymbiont of filarial nematodes and arthropods. While in worms the symbiosis is obligate, in arthropods Wolbachia induces several reproductive manipulations (i.e., cytoplasmic incompatibility, parthenogenesis, feminization of genetic males, and male-killing) in order to increase the number of infected females. These various phenotypic effects may be linked to differences in host physiology, and in particular to endocrine-related processes governing growth, development, and reproduction. Indeed, a number of evidences links Wolbachia symbiosis to insulin and ecdysteroid signaling, two multilayered pathways known to work antagonistically, jointly or even independently for the regulation of different molecular networks. At present it is not clear whether Wolbachia manipulates one pathway, thus affecting other related metabolic networks, or if it targets both pathways, even interacting at several points in each of them. Interestingly, in view of the interplay between hormone signaling and epigenetic machinery, a direct influence of the "infection" on hormonal signaling involving ecdysteroids might be achievable through the manipulation of the host's epigenetic pathways.}, }
@article {pmid22645538, year = {2011}, author = {Facchinelli, F and Weber, AP}, title = {The metabolite transporters of the plastid envelope: an update.}, journal = {Frontiers in plant science}, volume = {2}, number = {}, pages = {50}, pmid = {22645538}, issn = {1664-462X}, abstract = {The engulfment of a photoautotrophic cyanobacterium by a primitive mitochondria-bearing eukaryote traces back to more than 1.2 billion years ago. This single endosymbiotic event not only provided the early petroalgae with the metabolic capacity to perform oxygenic photosynthesis, but also introduced a plethora of other metabolic routes ranging from fatty acids and amino acids biosynthesis, nitrogen and sulfur assimilation to secondary compounds synthesis. This implicated the integration and coordination of the newly acquired metabolic entity with the host metabolism. The interface between the host cytosol and the plastidic stroma became of crucial importance in sorting precursors and products between the plastid and other cellular compartments. The plastid envelope membranes fulfill different tasks: they perform important metabolic functions, as they are involved in the synthesis of carotenoids, chlorophylls, and galactolipids. In addition, since most genes of cyanobacterial origin have been transferred to the nucleus, plastidial proteins encoded by nuclear genes are post-translationally transported across the envelopes through the TIC-TOC import machinery. Most importantly, chloroplasts supply the photoautotrophic cell with photosynthates in form of reduced carbon. The innermost bilayer of the plastidic envelope represents the permeability barrier for the metabolites involved in the carbon cycle and is literally stuffed with transporter proteins facilitating their transfer. The intracellular metabolite transporters consist of polytopic proteins containing membrane spans usually in the number of four or more α-helices. Phylogenetic analyses revealed that connecting the plastid with the host metabolism was mainly a process driven by the host cell. In Arabidopsis, 58% of the metabolite transporters are of host origin, whereas only 12% are attributable to the cyanobacterial endosymbiont. This review focuses on the metabolite transporters of the inner envelope membrane of plastids, in particular the electrochemical potential-driven class of transporters. Recent advances in elucidating the plastidial complement of metabolite transporters are provided, with an update on phylogenetic relationship of selected proteins.}, }
@article {pmid21188591, year = {2011}, author = {Appunu, C and Ganesan, G and Kalita, M and Kaushik, R and Saranya, B and Prabavathy, VR and Sudha, N}, title = {Phylogenetic diversity of rhizobia associated with horsegram [Macrotyloma uniflorum (Lam.) Verdc.] grown in South India based on glnII, recA and 16S-23S intergenic sequence analyses.}, journal = {Current microbiology}, volume = {62}, number = {4}, pages = {1230-1238}, pmid = {21188591}, issn = {1432-0991}, mesh = {Bacterial Proteins/*genetics ; Bacterial Typing Techniques ; *Biodiversity ; Bradyrhizobium/*classification/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics ; DNA, Intergenic/*genetics ; Fabaceae/*microbiology ; India ; Molecular Sequence Data ; *Phylogeny ; Plant Roots/microbiology ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; }, abstract = {Horsegram [Macrotyloma uniflorum (Lam.) Verdc.) is an important grain legume and fodder crop in India. Information on root nodule endosymbionts of this legume in India is limited. In the present study, 69 isolates from naturally occurring root nodules of horsegram collected from two agro-eco-climatic regions of South India was analyzed by generation rate, acid/alkali reaction on YMA medium, restriction fragment length polymorphism analysis of 16S-23S rDNA intergenic spacer region (IGS), and sequence analyses of IGS and housekeeping genes glnII and recA. Based on the rDNA IGS RFLP by means of three restriction enzymes rhizobia were grouped in five clusters (I-V). By sequence analysis of 16S-23S rDNA IGS identified genotypes of horsegram rhizobia were distributed into five divergent lineages of Bradyrhizobium genus which comprised (I) the IGS type IV rhizobia and valid species B. yuanmingense, (II) the strains of IGS type I and Bradyrhizobium sp. ORS 3257 isolated from Vigna sp., (III) the strains of the IGS type II and Bradyrhizobium sp. CIRADAc12 from Acacia sp., (IV) the IGS type V strains and Bradyrhizobium sp. genospecies IV, and (V) comprising genetically distinct IGS type III strains which probably represent an uncharacterized new genomic species. Nearly, 87% of indigenous horsegram isolates (IGS types I, II, III, and V) could not be related to any other species within the genus Bradyrhizobium. Phylogeny based on housekeeping glnII and recA genes confirmed those results found by the analysis of the IGS sequence. All the isolated rhizobia nodulated Macrotyloma sp. and Vigna spp., and only some of them formed nodules on Arachis hypogeae. The isolates within each IGS type varied in their ability to fix nitrogen. Selection for high symbiotic effective strains could reward horsegram production in poor soils of South India where this legume is largely cultivated.}, }
@article {pmid21183640, year = {2011}, author = {Gonella, E and Negri, I and Marzorati, M and Mandrioli, M and Sacchi, L and Pajoro, M and Crotti, E and Rizzi, A and Clementi, E and Tedeschi, R and Bandi, C and Alma, A and Daffonchio, D}, title = {Bacterial endosymbiont localization in Hyalesthes obsoletus, the insect vector of Bois noir in Vitis vinifera.}, journal = {Applied and environmental microbiology}, volume = {77}, number = {4}, pages = {1423-1435}, pmid = {21183640}, issn = {1098-5336}, mesh = {Animals ; Bacteroidetes/classification/isolation &amp; purification ; Base Sequence ; Betaproteobacteria/classification/isolation &amp; purification ; Denaturing Gradient Gel Electrophoresis ; Gammaproteobacteria/classification/isolation &amp; purification ; Hemiptera/*microbiology ; In Situ Hybridization, Fluorescence ; Insect Vectors/*microbiology ; Italy ; Microbial Consortia ; Molecular Sequence Data ; Phytoplasma/*pathogenicity ; Plant Diseases/*microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rickettsia/classification/isolation &amp; purification ; Sequence Analysis, DNA ; *Symbiosis ; Vitis/*microbiology ; }, abstract = {One emerging disease of grapevine in Europe is Bois noir (BN), a phytoplasmosis caused by "Candidatus Phytoplasma solani" and spread in vineyards by the planthopper Hyalesthes obsoletus (Hemiptera: Cixiidae). Here we present the first full characterization of the bacterial community of this important disease vector collected from BN-contaminated areas in Piedmont, Italy. Length heterogeneity PCR and denaturing gradient gel electrophoresis analysis targeting the 16S rRNA gene revealed the presence of a number of bacteria stably associated with the insect vector. In particular, symbiotic bacteria detected by PCR with high infection rates in adult individuals fell within the "Candidatus Sulcia muelleri" cluster in the Bacteroidetes and in the "Candidatus Purcelliella pentastirinorum" group in the Gammaproteobacteria, both previously identified in different leafhoppers and planthoppers. A high infection rate (81%) was also shown for another symbiont belonging to the Betaproteobacteria, designated the HO1-V symbiont. Because of the low level of 16S rRNA gene identity (80%) with the closest relative, an uncharacterized symbiont of the tick Haemaphysalis longicornis, we propose the new name "Candidatus Vidania fulgoroideae." Other bacterial endosymbionts identified in H. obsoletus were related to the intracellular bacteria Wolbachia pipientis, Rickettsia sp., and "Candidatus Cardinium hertigii." Fluorescent in situ hybridization coupled with confocal laser scanning microscopy and transmission electron microscopy showed that these bacteria are localized in the gut, testicles, and oocytes. As "Ca. Sulcia" is usually reported in association with other symbiotic bacteria, we propose that in H. obsoletus, it may occur in a bipartite or even tripartite relationship between "Ca. Sulcia" and "Ca. Purcelliella," "Ca. Vidania," or both.}, }
@article {pmid21182562, year = {2011}, author = {Glaser, KC and Hetrick, ND and Molestina, RE}, title = {Evidence for a previously unrecognized mycobacterial endosymbiont in Acanthamoeba castellanii strain Ma (ATCC ® 50370 ™).}, journal = {The Journal of eukaryotic microbiology}, volume = {58}, number = {1}, pages = {75-76}, doi = {10.1111/j.1550-7408.2010.00513.x}, pmid = {21182562}, issn = {1550-7408}, mesh = {Acanthamoeba castellanii/*microbiology/physiology ; Mycobacterium/genetics/isolation &amp; purification/*physiology ; *Symbiosis ; }, abstract = {We describe the isolation of a mycobacterium from Acanthamoeba castellanii strain Ma (ATCC(®) 50370(™)). The mycobacterium resides within vacuoles of A. castellanii, can be cultured by routine methodologies, and is a member of the Mycobacterium avium complex. Previously unrecognized mycobacterial endosymbionts are likely common among strains of Acanthamoeba housed at culture collections.}, }
@article {pmid21177682, year = {2011}, author = {Hansen, RD and Trees, AJ and Bah, GS and Hetzel, U and Martin, C and Bain, O and Tanya, VN and Makepeace, BL}, title = {A worm's best friend: recruitment of neutrophils by Wolbachia confounds eosinophil degranulation against the filarial nematode Onchocerca ochengi.}, journal = {Proceedings. Biological sciences}, volume = {278}, number = {1716}, pages = {2293-2302}, pmid = {21177682}, issn = {1471-2954}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Arsenicals/*pharmacology/therapeutic use ; Cameroon ; Cattle ; Cattle Diseases/*drug therapy/*parasitology ; Cell Degranulation/drug effects/*physiology ; Eosinophils/physiology ; Gene Expression Regulation/drug effects ; Histological Techniques ; Neutrophils/drug effects/*physiology ; Onchocerca/*microbiology ; Onchocerciasis/drug therapy/*veterinary ; Oxytetracycline/*pharmacology/therapeutic use ; Triazines/*pharmacology/therapeutic use ; Wolbachia/drug effects/immunology/*physiology ; }, abstract = {Onchocerca ochengi, a filarial parasite of cattle, represents the closest relative of the human pathogen, Onchocerca volvulus. Both species harbour Wolbachia endosymbionts and are remarkable in that adult female worms remain viable but sessile for many years while surrounded by host cells and antibodies. The basis of the symbiosis between filariae and Wolbachia is thought to be metabolic, although a role for Wolbachia in immune evasion has received little attention. Neutrophils are attracted to Wolbachia, but following antibiotic chemotherapy they are replaced by eosinophils that degranulate on the worm cuticle. However, it is unclear whether the eosinophils are involved in parasite killing or if they are attracted secondarily to dying worms. In this study, cattle infected with Onchocerca ochengi received adulticidal regimens of oxytetracycline or melarsomine. In contrast to oxytetracycline, melarsomine did not directly affect Wolbachia viability. Eosinophil degranulation increased significantly only in the oxytetracycline group; whereas nodular gene expression of bovine neutrophilic chemokines was lowest in this group. Moreover, intense eosinophil degranulation was initially associated with worm vitality, not degeneration. Taken together, these data offer strong support for the hypothesis that Wolbachia confers longevity on O. ochengi through a defensive mutualism, which diverts a potentially lethal effector cell response.}, }
@article {pmid21174352, year = {2010}, author = {Hafer, N and Pike, N}, title = {Shape change in viable eggs of the collembolan Folsomia candida provides insight into the role of Wolbachia endosymbionts.}, journal = {Dong wu xue yan jiu = Zoological research}, volume = {31}, number = {6}, pages = {623-626}, doi = {10.3724/SP.J.1141.2010.06623}, pmid = {21174352}, issn = {0254-5853}, mesh = {Animals ; Arthropods/*microbiology ; Female ; Ovum/cytology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {The endosymbiotic bacteria of the genus Wolbachia that infect the collembolan species Folsomia candida are responsible for facilitating parthenogenetic reproduction in their hosts. This study made empirical observations of the development of eggs of F. candida which contained normal populations of Wolbachia and of eggs which were cured of Wolbachia by treatment with the antibiotic rifampicin. A marked increase in egg size accompanied by a significant change in shape from spherical to discoid occurred in viable eggs three to four days after laying. These changes did not occur in the universally inviable eggs which came from the antibiotic treatment or in the 7% of untreated eggs which were naturally inviable. We infer that Wolbachia plays a critical role in zygotic or embryonic development during or before the first three days after laying and we draw on existing knowledge in speculating on the developmental mechanisms that Wolbachia may influence.}, }
@article {pmid21173021, year = {2011}, author = {Liberton, M and Austin, JR and Berg, RH and Pakrasi, HB}, title = {Unique thylakoid membrane architecture of a unicellular N2-fixing cyanobacterium revealed by electron tomography.}, journal = {Plant physiology}, volume = {155}, number = {4}, pages = {1656-1666}, pmid = {21173021}, issn = {1532-2548}, mesh = {Cyanobacteria/*cytology ; *Electron Microscope Tomography ; Intracellular Membranes/ultrastructure ; Thylakoids/*ultrastructure ; }, abstract = {Cyanobacteria, descendants of the endosymbiont that gave rise to modern-day chloroplasts, are vital contributors to global biological energy conversion processes. A thorough understanding of the physiology of cyanobacteria requires detailed knowledge of these organisms at the level of cellular architecture and organization. In these prokaryotes, the large membrane protein complexes of the photosynthetic and respiratory electron transport chains function in the intracellular thylakoid membranes. Like plants, the architecture of the thylakoid membranes in cyanobacteria has direct impact on cellular bioenergetics, protein transport, and molecular trafficking. However, whole-cell thylakoid organization in cyanobacteria is not well understood. Here we present, by using electron tomography, an in-depth analysis of the architecture of the thylakoid membranes in a unicellular cyanobacterium, Cyanothece sp. ATCC 51142. Based on the results of three-dimensional tomographic reconstructions of near-entire cells, we determined that the thylakoids in Cyanothece 51142 form a dense and complex network that extends throughout the entire cell. This thylakoid membrane network is formed from the branching and splitting of membranes and encloses a single lumenal space. The entire thylakoid network spirals as a peripheral ring of membranes around the cell, an organization that has not previously been described in a cyanobacterium. Within the thylakoid membrane network are areas of quasi-helical arrangement with similarities to the thylakoid membrane system in chloroplasts. This cyanobacterial thylakoid arrangement is an efficient means of packing a large volume of membranes in the cell while optimizing intracellular transport and trafficking.}, }
@article {pmid21171866, year = {2010}, author = {Belanger, DH and Perkins, SL}, title = {Wolbachia infection and mitochondrial diversity in the canine heartworm (Dirofilaria immitis).}, journal = {Mitochondrial DNA}, volume = {21}, number = {6}, pages = {227-233}, doi = {10.3109/19401736.2010.533765}, pmid = {21171866}, issn = {1940-1744}, mesh = {Animals ; Carnivora/parasitology ; DNA, Helminth/genetics ; DNA, Mitochondrial/*genetics ; Dirofilaria immitis/cytology/*genetics/*microbiology ; *Genetic Variation ; North America ; Wolbachia/*physiology ; }, abstract = {BACKGROUND AND AIMS: Many species of filarial nematodes are infected with Wolbachia pipientis, a maternally inherited endosymbiont. In addition to manipulating host reproduction, these bacteria also affect the evolution of the mitochondrial DNA with which they are transmitted. Selective sweeps can establish a single mitochondrial lineage within a Wolbachia-infected population and purge genetic diversity. While this phenomenon has been studied in insect model systems, it has not been thoroughly examined in a filarial nematode.<br><br>MATERIALS AND METHODS: Patterns of mitochondrial diversity were examined in Dirofilaria immitis, a Wolbachia-infected species.<br><br>RESULTS: The levels of genetic diversity observed in canine heartworm were much lower than those in related species not known to be hosts of Wolbachia.<br><br>CONCLUSION: RESULTS suggest that a maternally inherited endosymbiont can depress mitochondrial diversity in a filarial host.}, }
@article {pmid21159868, year = {2011}, author = {Cilia, M and Tamborindeguy, C and Fish, T and Howe, K and Thannhauser, TW and Gray, S}, title = {Genetics coupled to quantitative intact proteomics links heritable aphid and endosymbiont protein expression to circulative polerovirus transmission.}, journal = {Journal of virology}, volume = {85}, number = {5}, pages = {2148-2166}, pmid = {21159868}, issn = {1098-5514}, mesh = {Animals ; Aphids/*genetics/microbiology/physiology/*virology ; Bacterial Proteins/*chemistry/genetics/metabolism ; Buchnera/chemistry/*genetics/physiology ; Edible Grain/virology ; Gene Expression ; Insect Proteins/*chemistry/genetics/metabolism ; Luteoviridae/*physiology ; Molecular Sequence Data ; Plant Diseases/*virology ; *Proteomics ; Symbiosis ; Two-Dimensional Difference Gel Electrophoresis ; }, abstract = {Yellow dwarf viruses in the family Luteoviridae, which are the causal agents of yellow dwarf disease in cereal crops, are each transmitted most efficiently by different species of aphids in a circulative manner that requires the virus to interact with a multitude of aphid proteins. Aphid proteins differentially expressed in F2 Schizaphis graminum genotypes segregating for the ability to transmit Cereal yellow dwarf virus-RPV (CYDV-RPV) were identified using two-dimensional difference gel electrophoresis (DIGE) coupled to either matrix-assisted laser desorption ionization-tandem mass spectrometry or online nanoscale liquid chromatography coupled to electrospray tandem mass spectrometry. A total of 50 protein spots, containing aphid proteins and proteins from the aphid's obligate and maternally inherited bacterial endosymbiont, Buchnera, were identified as differentially expressed between transmission-competent and refractive aphids. Surprisingly, in virus transmission-competent F2 genotypes, the isoelectric points of the Buchnera proteins did not match those in the maternal Buchnera proteome as expected, but instead they aligned with the Buchnera proteome of the transmission-competent paternal parent. Among the aphid proteins identified, many were involved in energy metabolism, membrane trafficking, lipid signaling, and the cytoskeleton. At least eight aphid proteins were expressed as heritable, isoelectric point isoform pairs, one derived from each parental lineage. In the F2 genotypes, the expression of aphid protein isoforms derived from the competent parental lineage aligned with the virus transmission phenotype with high precision. Thus, these isoforms are candidate biomarkers for CYDV-RPV transmission in S. graminum. Our combined genetic and DIGE approach also made it possible to predict where several of the proteins may be expressed in refractive aphids with different barriers to transmission. Twelve proteins were predicted to act in the hindgut of the aphid, while six proteins were predicted to be associated with the accessory salivary glands or hemolymph. Knowledge of the proteins that regulate virus transmission and their predicted locations will aid in understanding the biochemical mechanisms regulating circulative virus transmission in aphids, as well as in identifying new targets to block transmission.}, }
@article {pmid21155960, year = {2011}, author = {Jaenike, J and Brekke, TD}, title = {Defensive endosymbionts: a cryptic trophic level in community ecology.}, journal = {Ecology letters}, volume = {14}, number = {2}, pages = {150-155}, doi = {10.1111/j.1461-0248.2010.01564.x}, pmid = {21155960}, issn = {1461-0248}, mesh = {Animals ; Biota ; Drosophila/genetics/*microbiology/*parasitology ; Female ; Host-Parasite Interactions ; Male ; New York ; Reproduction ; Selection, Genetic ; Spiroplasma/genetics/physiology ; Symbiosis ; Tylenchida/genetics/*microbiology ; }, abstract = {Maternally transmitted endosymbionts are widespread among insects, but how they are maintained within host populations is largely unknown. Recent discoveries show that some endosymbionts protect their hosts from pathogens or parasites. Spiroplasma, an endosymbiont of Drosophila neotestacea, protects female hosts from the sterilizing effects of parasitism by the nematode Howardula aoronymphium. Here, we show that Spiroplasma spreads rapidly within experimental populations of D. neotestacea subject to Howardula parasitism, but is neither strongly favored nor selected against in the absence of Howardula. In a reciprocal experiment, Howardula declined steadily to extinction in populations of Spiroplasma-infected flies, whereas in populations of uninfected flies, the prevalence of Howardula parasitism increased to c. 100%. Thus, Spiroplasma and Howardula exhibit effectively consumer-resource trophic dynamics. The recent spread of Spiroplasma in natural populations of D. neotestacea coincides with a decline in the prevalence of Howardula parasitism in the wild.}, }
@article {pmid21155074, year = {2010}, author = {Higuchi, T and Fujimura, H and Hitomi, Y and Arakaki, T and Oomori, T and Suzuki, Y}, title = {Photochemical formation of hydroxyl radicals in tissue extracts of the coral Galaxea fascicularis.}, journal = {Photochemistry and photobiology}, volume = {86}, number = {6}, pages = {1421-1426}, doi = {10.1111/j.1751-1097.2010.00802.x}, pmid = {21155074}, issn = {1751-1097}, mesh = {Animals ; Anthozoa/*metabolism/*radiation effects ; Dinoflagellida/metabolism/radiation effects ; Hydroxyl Radical/*metabolism ; Iron/metabolism ; Photobleaching/radiation effects ; Photochemical Processes ; Reactive Oxygen Species/metabolism ; Sunlight/adverse effects ; Symbiosis ; }, abstract = {Various stresses induce the formation of reactive oxygen species (ROS) in biological cells. In addition to stress-induced ROS, we studied the photochemical formation of hydroxyl radicals (˙OH), the most potent ROS, in coral tissues using phosphate buffer-extracted solutions and a simulated sunlight irradiation system. ˙OH formation was seen in extracts of both coral host and endosymbiont zooxanthellae. This study is the first to report quantitative measurements of ˙OH photoformation in coral tissue extracts. Our results indicated that whether or not coral bleaching occurred, coral tissues and symbiotic zooxanthellae have the potential to photochemically produce ˙OH under sunlight. However, no significant difference was found in the protein content-normalized formation rates of ˙OH between corals incubated under different temperatures and irradiance conditions. ˙OH formation rates were reduced by 40% by reducing the UV radiation in the illumination. It was indicated that UV radiation strongly affected ˙OH formation in coral tissue and zooxanthellae, in addition to its formation through photoinhibition processes.}, }
@article {pmid21151959, year = {2010}, author = {Miller, WJ and Ehrman, L and Schneider, D}, title = {Infectious speciation revisited: impact of symbiont-depletion on female fitness and mating behavior of Drosophila paulistorum.}, journal = {PLoS pathogens}, volume = {6}, number = {12}, pages = {e1001214}, pmid = {21151959}, issn = {1553-7374}, support = {P 22634/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Biological Evolution ; Drosophila/*microbiology ; Female ; *Fertility ; *Sexual Behavior, Animal ; *Symbiosis ; Wolbachia ; }, abstract = {The neotropical Drosophila paulistorum superspecies, consisting of at least six geographically overlapping but reproductively isolated semispecies, has been the object of extensive research since at least 1955, when it was initially trapped mid-evolution in flagrant statu nascendi. In this classic system females express strong premating isolation patterns against mates belonging to any other semispecies, and yet uncharacterized microbial reproductive tract symbionts were described triggering hybrid inviability and male sterility. Based on theoretical models and limited experimental data, prime candidates fostering symbiont-driven speciation in arthropods are intracellular bacteria belonging to the genus Wolbachia. They are maternally inherited symbionts of many arthropods capable of manipulating host reproductive biology for their own benefits. However, it is an ongoing debate as to whether or not reproductive symbionts are capable of driving host speciation in nature and if so, to what extent. Here we have reevaluated this classic case of infectious speciation by means of present day molecular approaches and artificial symbiont depletion experiments. We have isolated the α-proteobacteria Wolbachia as the maternally transmitted core endosymbionts of all D. paulistorum semispecies that have coevolved towards obligate mutualism with their respective native hosts. In hybrids, however, these mutualists transform into pathogens by overreplication causing embryonic inviability and male sterility. We show that experimental reduction in native Wolbachia titer causes alterations in sex ratio, fecundity, and mate discrimination. Our results indicate that formerly designated Mycoplasma-like organisms are most likely Wolbachia that have evolved by becoming essential mutualistic symbionts in their respective natural hosts; they have the potential to trigger pre- and postmating isolation. Furthermore, in light of our new findings, we revisit the concept of infectious speciation and discuss potential mechanisms that can restrict or promote symbiont-induced speciation at post- and prezygotic levels in nature and under artificial laboratory conditions.}, }
@article {pmid21148414, year = {2011}, author = {Voss, B and Meinecke, L and Kurz, T and Al-Babili, S and Beck, CF and Hess, WR}, title = {Hemin and magnesium-protoporphyrin IX induce global changes in gene expression in Chlamydomonas reinhardtii.}, journal = {Plant physiology}, volume = {155}, number = {2}, pages = {892-905}, pmid = {21148414}, issn = {1532-2548}, mesh = {Chlamydomonas reinhardtii/drug effects/*genetics ; Cluster Analysis ; Gene Expression Profiling ; *Gene Expression Regulation, Plant ; Genes, Plant ; Heat-Shock Proteins/genetics/metabolism ; Hemin/*pharmacology ; Oligonucleotide Array Sequence Analysis ; Phylogeny ; Plant Proteins/genetics/metabolism ; Protoporphyrins/*pharmacology ; RNA, Plant/genetics ; }, abstract = {Retrograde signaling is a pathway of communication from mitochondria and plastids to the nucleus in the context of cell differentiation, development, and stress response. In Chlamydomonas reinhardtii, the tetrapyrroles magnesium-protoporphyrin IX and heme are only synthesized within the chloroplast, and they have been implicated in the retrograde control of nuclear gene expression in this unicellular green alga. Feeding the two tetrapyrroles to Chlamydomonas cultures was previously shown to transiently induce five nuclear genes, three of which encode the heat shock proteins HSP70A, HSP70B, and HSP70E. In contrast, controversial results exist on the possible role of magnesium-protoporphyrin IX in the repression of genes for light-harvesting proteins in higher plants, raising the question of how important this mode of regulation is. Here, we used genome-wide transcriptional profiling to measure the global impact of these tetrapyrroles on gene regulation and the scope of the response. We identified almost 1,000 genes whose expression level changed transiently but significantly. Among them were only a few genes for photosynthetic proteins but several encoding enzymes of the tricarboxylic acid cycle, heme-binding proteins, stress-response proteins, as well as proteins involved in protein folding and degradation. More than 50% of the latter class of genes was also regulated by heat shock. The observed drastic fold changes at the RNA level did not correlate with similar changes in protein concentrations under the tested experimental conditions. Phylogenetic profiling revealed that genes of putative endosymbiontic origin are not overrepresented among the responding genes. This and the transient nature of changes in gene expression suggest a signaling role of both tetrapyrroles as secondary messengers for adaptive responses affecting the entire cell and not only organellar proteins.}, }
@article {pmid21147880, year = {2011}, author = {Tanifuji, G and Onodera, NT and Wheeler, TJ and Dlutek, M and Donaher, N and Archibald, JM}, title = {Complete nucleomorph genome sequence of the nonphotosynthetic alga Cryptomonas paramecium reveals a core nucleomorph gene set.}, journal = {Genome biology and evolution}, volume = {3}, number = {}, pages = {44-54}, pmid = {21147880}, issn = {1759-6653}, support = {MOP-85016//Canadian Institutes of Health Research/Canada ; }, mesh = {Base Sequence ; Cell Nucleus/*genetics ; Chlorophyta/genetics ; *Chromosome Mapping ; Chromosome Structures ; Conserved Sequence ; Cryptophyta/*genetics ; Genes ; *Genome ; Molecular Sequence Data ; Open Reading Frames ; Plastids/genetics ; Rhodophyta/genetics ; *Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Nucleomorphs are the remnant nuclei of algal endosymbionts that were engulfed by nonphotosynthetic host eukaryotes. These peculiar organelles are found in cryptomonad and chlorarachniophyte algae, where they evolved from red and green algal endosymbionts, respectively. Despite their independent origins, cryptomonad and chlorarachniophyte nucleomorph genomes are similar in size and structure: they are both <1 million base pairs in size (the smallest nuclear genomes known), comprised three chromosomes, and possess subtelomeric ribosomal DNA operons. Here, we report the complete sequence of one of the smallest cryptomonad nucleomorph genomes known, that of the secondarily nonphotosynthetic cryptomonad Cryptomonas paramecium. The genome is 486 kbp in size and contains 518 predicted genes, 466 of which are protein coding. Although C. paramecium lacks photosynthetic ability, its nucleomorph genome still encodes 18 plastid-associated proteins. More than 90% of the "conserved" protein genes in C. paramecium (i.e., those with clear homologs in other eukaryotes) are also present in the nucleomorph genomes of the cryptomonads Guillardia theta and Hemiselmis andersenii. In contrast, 143 of 466 predicted C. paramecium proteins (30.7%) showed no obvious similarity to proteins encoded in any other genome, including G. theta and H. andersenii. Significantly, however, many of these "nucleomorph ORFans" are conserved in position and size between the three genomes, suggesting that they are in fact homologous to one another. Finally, our analyses reveal an unexpected degree of overlap in the genes present in the independently evolved chlorarachniophyte and cryptomonad nucleomorph genomes: ∼80% of a set of 120 conserved nucleomorph genes in the chlorarachniophyte Bigelowiella natans were also present in all three cryptomonad nucleomorph genomes. This result suggests that similar reductive processes have taken place in unrelated lineages of nucleomorph-containing algae.}, }
@article {pmid21147476, year = {2010}, author = {Lee, AC and Atkins, CE}, title = {Understanding feline heartworm infection: disease, diagnosis, and treatment.}, journal = {Topics in companion animal medicine}, volume = {25}, number = {4}, pages = {224-230}, doi = {10.1053/j.tcam.2010.09.003}, pmid = {21147476}, issn = {1946-9837}, mesh = {Animals ; Cat Diseases/*diagnosis/diagnostic imaging/surgery ; Cats ; Dirofilaria immitis/pathogenicity/*physiology ; Dirofilariasis/*diagnosis/diagnostic imaging/surgery ; Echocardiography/veterinary ; Female ; Life Cycle Stages ; Male ; Prognosis ; Pulmonary Artery/diagnostic imaging/pathology ; Radiography, Thoracic/veterinary ; Remission, Spontaneous ; Risk Factors ; }, abstract = {Feline heartworm disease is a very different clinical entity from canine heartworm disease. In cats, the arrival and death of immature heartworms in the pulmonary arteries can cause coughing and dyspnea as early as 3 months postinfection. Adult heartworms suppress the function of pulmonary intravascular macrophages and thus reduce clinical disease in chronic feline heartworm infection. Approximately 80% of asymptomatic cats self-cure. Median survival time for symptomatic cats is 1.5 years, or 4 years if only cats living beyond the day of presentation are considered. Aberrant worm migration is more frequent than it is in dogs, and sudden death can occur with no prior clinical signs. The bacterial endosymbiont Wolbachia likely contributes to the inflammatory pathology of heartworm disease, but its role is not yet fully clear. Unfortunately, the diagnosis, treatment, and management of feline heartworm disease are far from simple. Antemortem diagnosis is hampered by low worm burdens, the frequency of all-male infections, and nonspecific radiographic lesions. It is up to the veterinarian to determine the correct index of suspicion and choose the right combination of diagnostic tests to achieve an answer. Treatment is symptomatic because adulticide therapy is risky and does not increase survival time. Despite the dangers of feline heartworm disease, less than 5% of cats in the United States are on chemoprophylaxis. It is important for veterinarians to take a proactive preventive stance because heartworm infection in cats is a multisystemic disease that has no easy cure.}, }
@article {pmid21134098, year = {2011}, author = {Lenk, S and Arnds, J and Zerjatke, K and Musat, N and Amann, R and Mussmann, M}, title = {Novel groups of Gammaproteobacteria catalyse sulfur oxidation and carbon fixation in a coastal, intertidal sediment.}, journal = {Environmental microbiology}, volume = {13}, number = {3}, pages = {758-774}, doi = {10.1111/j.1462-2920.2010.02380.x}, pmid = {21134098}, issn = {1462-2920}, mesh = {Biocatalysis ; *Carbon Cycle ; Gammaproteobacteria/classification/genetics/*metabolism ; Genes, rRNA ; Geologic Sediments/*microbiology ; Hydrogensulfite Reductase/genetics ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sulfides/metabolism ; Sulfur/*metabolism ; }, abstract = {The oxidation of hydrogen sulfide is essential to sulfur cycling in marine habitats. However, the role of microbial sulfur oxidation in marine sediments and the microorganisms involved are largely unknown, except for the filamentous, mat-forming bacteria. In this study we explored the diversity, abundance and activity of sulfur-oxidizing prokaryotes (SOP) in sulfidic intertidal sediments using 16S rRNA and functional gene sequence analyses, fluorescence in situ hybridization (FISH) and microautoradiography. The 16S rRNA gene analysis revealed that distinct clades of uncultured Gammaproteobacteria are important SOP in the tidal sediments. This was supported by the dominance of gammaproteobacterial sequences in clone libraries of genes encoding the reverse dissimilatory sulfite reductase (rDSR) and the adenosine phosphosulfate reductase (APR). Numerous sequences of all three genes grouped with uncultured autotrophic SOP. Accordingly, Gammaproteobacteria accounted for 40-70% of all [14]CO2 -incorporating cells in surface sediments as shown by microautoradiography. Furthermore, phylogenetic analysis of all three genes consistently suggested a discrete population of SOP that was most closely related to the sulfur-oxidizing endosymbionts of the tubeworm Oligobrachia spp. FISH showed that members of this population (WS-Gam209 group) were abundant, reaching up to 1.3 × 10[8] cells ml[-1] (4.6% of all cells). Approximately 25% of this population incorporated CO2, consistent with a chemolithoautotrophic metabolism most likely based on sulfur oxidation. Thus, we hypothesize that novel, gammaproteobacterial SOP attached to sediment particles may play a more important role for sulfide removal and primary production in marine sediments than previously assumed.}, }
@article {pmid21131495, year = {2011}, author = {Lackner, G and Moebius, N and Partida-Martinez, L and Hertweck, C}, title = {Complete genome sequence of Burkholderia rhizoxinica, an Endosymbiont of Rhizopus microsporus.}, journal = {Journal of bacteriology}, volume = {193}, number = {3}, pages = {783-784}, pmid = {21131495}, issn = {1098-5530}, mesh = {Burkholderia/*genetics ; Chromosomes, Bacterial ; DNA, Bacterial/*chemistry/*genetics ; *Genome, Bacterial ; Molecular Sequence Data ; Plasmids ; Sequence Analysis, DNA ; }, abstract = {Burkholderia rhizoxinica is an intracellular symbiont of the phytopathogenic fungus Rhizopus microsporus. The vertically transmitted endosymbiont not only delivers the antimitotic macrolide rhizoxin to its host but is also essential for vegetative spore formation of the fungus. To shed light on the genetic equipment of this model organism, we sequenced the whole genome of B. rhizoxinica HKI 0454, thus providing the first genomic insight into an intracellular mutualist of a fungal species. The 3.75-Mb genome consists of a chromosome and two strain-specific plasmids. The primary metabolism appears to be specialized for the uptake of fungal metabolites. Besides the rhizoxin biosynthesis gene cluster, there are 14 loci coding for nonribosomal peptide synthetase (NRPS) assembly lines, which represent novel targets for genomic mining of cryptic natural products. Furthermore, the endosymbionts are equipped with a repertoire of virulence-related factors, which can now be studied to elucidate molecular mechanisms underlying bacterial-fungal interaction.}, }
@article {pmid21122115, year = {2010}, author = {Stoll, S and Feldhaar, H and Fraunholz, MJ and Gross, R}, title = {Bacteriocyte dynamics during development of a holometabolous insect, the carpenter ant Camponotus floridanus.}, journal = {BMC microbiology}, volume = {10}, number = {}, pages = {308}, pmid = {21122115}, issn = {1471-2180}, mesh = {Animals ; Ants/*growth &amp; development/*microbiology/physiology ; Enterobacteriaceae/*physiology ; Gastrointestinal Tract/microbiology/physiology ; Larva/microbiology/physiology ; Metamorphosis, Biological ; Symbiosis ; }, abstract = {BACKGROUND: The carpenter ant Camponotus floridanus harbors obligate intracellular mutualistic bacteria (Blochmannia floridanus) in specialized cells, the bacteriocytes, intercalated in their midgut tissue. The diffuse distribution of bacteriocytes over the midgut tissue is in contrast to many other insects carrying endosymbionts in specialized tissues which are often connected to the midgut but form a distinct organ, the bacteriome. C. floridanus is a holometabolous insect which undergoes a complete metamorphosis. During pupal stages a complete restructuring of the inner organs including the digestive tract takes place. So far, nothing was known about maintenance of endosymbionts during this life stage of a holometabolous insect. It was shown previously that the number of Blochmannia increases strongly during metamorphosis. This implicates an important function of Blochmannia in this developmental phase during which the animals are metabolically very active but do not have access to external food resources. Previous experiments have shown a nutritional contribution of the bacteria to host metabolism by production of essential amino acids and urease-mediated nitrogen recycling. In adult hosts the symbiosis appears to degenerate with increasing age of the animals.<br><br>RESULTS: We investigated the distribution and dynamics of endosymbiotic bacteria and bacteriocytes at different stages during development of the animals from larva to imago by confocal laser scanning microscopy. The number of bacteriocytes in relation to symbiont-free midgut cells varied strongly over different developmental stages. Especially during metamorphosis the relative number of bacteria-filled bacteriocytes increased strongly when the larval midgut epithelium is shed. During this developmental stage the midgut itself became a huge symbiotic organ consisting almost exclusively of cells harboring bacteria. In fact, during this phase some bacteria were also found in midgut cells other than bacteriocytes indicating a cell-invasive capacity of Blochmannia. In adult animals the number of bacteriocytes generally decreased.<br><br>CONCLUSIONS: During the life cycle of the animals the distribution of bacteriocytes and of Blochmannia endosymbionts is remarkably dynamic. Our data show how the endosymbiont is retained within the midgut tissue during metamorphosis thereby ensuring the maintenance of the intracellular endosymbiosis despite a massive reorganization of the midgut tissue. The transformation of the entire midgut into a symbiotic organ during pupal stages underscores the important role of Blochmannia for its host in particular during metamorphosis.}, }
@article {pmid21114563, year = {2011}, author = {Atyame, CM and Duron, O and Tortosa, P and Pasteur, N and Fort, P and Weill, M}, title = {Multiple Wolbachia determinants control the evolution of cytoplasmic incompatibilities in Culex pipiens mosquito populations.}, journal = {Molecular ecology}, volume = {20}, number = {2}, pages = {286-298}, doi = {10.1111/j.1365-294X.2010.04937.x}, pmid = {21114563}, issn = {1365-294X}, mesh = {Animals ; Biological Evolution ; Crosses, Genetic ; Culex/genetics/*microbiology/*physiology ; Cytoplasm/physiology ; DNA, Mitochondrial/genetics ; Female ; Genetic Markers ; Indian Ocean ; Male ; Mitosis ; Polymerase Chain Reaction ; *Polymorphism, Genetic ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*genetics/*physiology ; }, abstract = {Wolbachia are maternally inherited endosymbionts that can invade arthropod populations through manipulation of their reproduction. In mosquitoes, Wolbachia induce embryonic death, known as cytoplasmic incompatibility (CI), whenever infected males mate with females either uninfected or infected with an incompatible strain. Although genetic determinants of CI are unknown, a functional model involving the so-called mod and resc factors has been proposed. Natural populations of Culex pipiens mosquito display a complex CI relationship pattern associated with the highest Wolbachia (wPip) genetic polymorphism reported so far. We show here that C. pipiens populations from La Réunion, a geographically isolated island in the southwest of the Indian Ocean, are infected with genetically closely related wPip strains. Crossing experiments reveal that these Wolbachia are all mutually compatible. However, crosses with genetically more distant wPip strains indicate that Wolbachia strains from La Réunion belong to at least five distinct incompatibility groups (or crossing types). These incompatibility properties which are strictly independent from the nuclear background, formally establish that in C. pipiens, CI is controlled by several Wolbachia mod/resc factors.}, }
@article {pmid21110016, year = {2011}, author = {Schrallhammer, M and Schweikert, M and Vallesi, A and Verni, F and Petroni, G}, title = {Detection of a novel subspecies of Francisella noatunensis as endosymbiont of the ciliate Euplotes raikovi.}, journal = {Microbial ecology}, volume = {61}, number = {2}, pages = {455-464}, pmid = {21110016}, issn = {1432-184X}, mesh = {DNA, Bacterial/genetics ; Euplotes/*microbiology/ultrastructure ; Francisella/*classification/genetics/isolation &amp; purification ; *Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Francisella are facultative intracellular bacteria causing severe disease in a broad range of animals. Two species are notable: Francisella tularensis, the causative organism of tularemia and a putative warfare agent, and Francisella noatunensis, an emerging fish pathogen causing significant losses in wild and farmed fish. Although various aspects of Francisella biology have been intensively studied, their natural reservoir in periods between massive outbreaks remains mysterious. Protists have been suspected to serve as a disguised vector of Francisella and co-culturing attempts demonstrate that some species are able to survive and multiply within protozoan cells. Here, we report the first finding of a natural occurrence of Francisella sp. as a protist endosymbiont. By molecular and morphological approaches, we identified intracellular bacteria localized in a strain of the marine ciliate Euplotes raikovi, isolated from the coast of Adriatic Sea. Phylogenetic analysis placed these endosymbionts within the genus Francisella, in close but distinct association with F. noatunensis. We suggest the establishment of a novel subspecies within F. noatunensis and propose the cytoplasmatic endosymbiont of E. raikovi as "Candidatus F. noatunensis subsp. endociliophora" subsp. nov.}, }
@article {pmid21108805, year = {2010}, author = {Brinza, L and Calevro, F and Duport, G and Gaget, K and Gautier, C and Charles, H}, title = {Structure and dynamics of the operon map of Buchnera aphidicola sp. strain APS.}, journal = {BMC genomics}, volume = {11}, number = {}, pages = {666}, pmid = {21108805}, issn = {1471-2164}, mesh = {Base Sequence ; Buchnera/*genetics ; Codon/genetics ; Conserved Sequence/genetics ; DNA, Intergenic/genetics ; Escherichia coli/genetics ; Evolution, Molecular ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Models, Genetic ; Oligonucleotide Array Sequence Analysis ; Open Reading Frames/genetics ; Operon/*genetics ; Promoter Regions, Genetic/genetics ; ROC Curve ; Reproducibility of Results ; Reverse Transcriptase Polymerase Chain Reaction ; Terminator Regions, Genetic/genetics ; Transcription, Genetic ; }, abstract = {BACKGROUND: Gene expression regulation is still poorly documented in bacteria with highly reduced genomes. Understanding the evolution and mechanisms underlying the regulation of gene transcription in Buchnera aphidicola, the primary endosymbiont of aphids, is expected both to enhance our understanding of this nutritionally based association and to provide an intriguing case-study of the evolution of gene expression regulation in a reduced bacterial genome.<br><br>RESULTS: A Bayesian predictor was defined to infer the B. aphidicola transcription units, which were further validated using transcriptomic data and RT-PCR experiments. The characteristics of B. aphidicola predicted transcription units (TUs) were analyzed in order to evaluate the impact of operon map organization on the regulation of gene transcription.On average, B. aphidicola TUs contain more genes than those of E. coli. The global layout of B. aphidicola operon map was mainly shaped by the big reduction and the rearrangements events, which occurred at the early stage of the symbiosis. Our analysis suggests that this operon map may evolve further only by small reorganizations around the frontiers of B. aphidicola TUs, through promoter and/or terminator sequence modifications and/or by pseudogenization events. We also found that the need for specific transcription regulation exerts some pressure on gene conservation, but not on gene assembling in the operon map in Buchnera. Our analysis of the TUs spacing pointed out that a selection pressure is maintained on the length of the intergenic regions between divergent adjacent gene pairs.<br><br>CONCLUSIONS: B. aphidicola can seemingly only evolve towards a more polycistronic operon map. This implies that gene transcription regulation is probably subject to weak selection pressure in Buchnera conserving operons composed of genes with unrelated functions.}, }
@article {pmid21107996, year = {2011}, author = {Famah Sourassou, N and Hanna, R and Zannou, I and de Moraes, G and Negloh, K and Sabelis, MW}, title = {Morphological variation and reproductive incompatibility of three coconut-mite-associated populations of predatory mites identified as Neoseiulus paspalivorus (Acari: Phytoseiidae).}, journal = {Experimental &amp; applied acarology}, volume = {53}, number = {4}, pages = {323-338}, pmid = {21107996}, issn = {1572-9702}, mesh = {Animals ; Benin ; Brazil ; Breeding ; Crosses, Genetic ; Feeding Behavior ; Female ; Geography ; Ghana ; Male ; Mites/*anatomy &amp; histology/classification/physiology ; Pest Control, Biological ; Predatory Behavior ; Principal Component Analysis ; Sexual Behavior, Animal ; Species Specificity ; }, abstract = {Predatory mites identified as Neoseiulus paspalivorus DeLeon (Phytoseiidae) have been considered as agents for classical biological control of the coconut mite, Aceria guerreronis Keifer (Eriophyidae), in Africa and elsewhere. Preliminary identification of geographically distinct populations as belonging to the same species (N. paspalivorus) was based on their morphological similarity. However, laboratory studies recently conducted have shown large differences in feeding behaviors and biological characteristics among individuals collected from three geographic origins: Brazil (South America), Benin and Ghana (West Africa). As morphologically similar specimens do not necessarily belong to the same species, we evaluated under laboratory conditions, reproductive compatibility between the specimens from three geographic locations to ascertain their conspecificity. Morphological measurements were also made to determine whether there is a means of discriminating between them. Inter-population crosses showed complete reproductive isolation between the three geographic populations, but interpopulation discontinuities in morphometric characters were absent. These results indicate that the tested specimens are distinct biological entities despite morphological similarity. Further molecular genetic studies are therefore proposed, including screening for endosymbionts and assessment of genetic differentiation, to determine the cause of reproductive incompatibility and to clarify the taxonomic relationship between those populations.}, }
@article {pmid21103042, year = {2010}, author = {Starcevic, A and Dunlap, WC and Cullum, J and Shick, JM and Hranueli, D and Long, PF}, title = {Gene expression in the scleractinian Acropora microphthalma exposed to high solar irradiance reveals elements of photoprotection and coral bleaching.}, journal = {PloS one}, volume = {5}, number = {11}, pages = {e13975}, pmid = {21103042}, issn = {1932-6203}, support = {BB/H010009/2//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Anthozoa/*genetics/metabolism/microbiology ; Base Sequence ; Biosynthetic Pathways ; Cyanobacteria/*genetics/physiology ; Cyclohexanols/chemistry/metabolism ; DNA, Complementary/chemistry/genetics ; Gene Expression/radiation effects ; *Gene Expression Profiling ; Gene Library ; Molecular Sequence Data ; Molecular Structure ; Nucleic Acid Hybridization/methods ; Sequence Analysis, DNA ; Sunlight ; Symbiosis/*genetics/radiation effects ; }, abstract = {BACKGROUND: The success of tropical reef-building corals depends on the metabolic co-operation between the animal host and the photosynthetic performance of endosymbiotic algae residing within its cells. To examine the molecular response of the coral Acropora microphthalma to high levels of solar irradiance, a cDNA library was constructed by PCR-based suppression subtractive hybridisation (PCR-SSH) from mRNA obtained by transplantation of a colony from a depth of 12.7 m to near-surface solar irradiance, during which the coral became noticeably paler from loss of endosymbionts in sun-exposed tissues.<br><br>A novel approach to sequence annotation of the cDNA library gave genetic evidence for a hypothetical biosynthetic pathway branching from the shikimic acid pathway that leads to the formation of 4-deoxygadusol. This metabolite is a potent antioxidant and expected precursor of the UV-protective mycosporine-like amino acids (MAAs), which serve as sunscreens in coral phototrophic symbiosis. Empirical PCR based evidence further upholds the contention that the biosynthesis of these MAA sunscreens is a 'shared metabolic adaptation' between the symbiotic partners. Additionally, gene expression induced by enhanced solar irradiance reveals a cellular mechanism of light-induced coral bleaching that invokes a Ca(2+)-binding synaptotagmin-like regulator of SNARE protein assembly of phagosomal exocytosis, whereby algal partners are lost from the symbiosis.<br><br>CONCLUSIONS/SIGNIFICANCE: Bioinformatics analyses of DNA sequences obtained by differential gene expression of a coral exposed to high solar irradiance has revealed the identification of putative genes encoding key steps of the MAA biosynthetic pathway. Revealed also by this treatment are genes that implicate exocytosis as a cellular process contributing to a breakdown in the metabolically essential partnership between the coral host and endosymbiotic algae, which manifests as coral bleaching.}, }
@article {pmid21097935, year = {2010}, author = {Tsuchida, T and Koga, R and Horikawa, M and Tsunoda, T and Maoka, T and Matsumoto, S and Simon, JC and Fukatsu, T}, title = {Symbiotic bacterium modifies aphid body color.}, journal = {Science (New York, N.Y.)}, volume = {330}, number = {6007}, pages = {1102-1104}, doi = {10.1126/science.1195463}, pmid = {21097935}, issn = {1095-9203}, mesh = {Animals ; Aphids/*microbiology/physiology ; Carotenoids/metabolism ; Color ; Coxiellaceae/classification/*physiology ; Phylogeny ; *Symbiosis ; }, abstract = {Color variation within populations of the pea aphid influences relative susceptibility to predators and parasites. We have discovered that infection with a facultative endosymbiont of the genus Rickettsiella changes the insects' body color from red to green in natural populations. Approximately 8% of pea aphids collected in Western Europe carried the Rickettsiella infection. The infection increased amounts of blue-green polycyclic quinones, whereas it had less of an effect on yellow-red carotenoid pigments. The effect of the endosymbiont on body color is expected to influence prey-predator interactions, as well as interactions with other endosymbionts.}, }
@article {pmid21092357, year = {2010}, author = {Burdíková, Z and Capek, M and Ostašov, P and Machač, J and Pelc, R and Mitchell, EA and Kubínová, L}, title = {Testate amoebae examined by confocal and two-photon microscopy: implications for taxonomy and ecophysiology.}, journal = {Microscopy and microanalysis : the official journal of Microscopy Society of America, Microbeam Analysis Society, Microscopical Society of Canada}, volume = {16}, number = {6}, pages = {735-746}, doi = {10.1017/S1431927610094031}, pmid = {21092357}, issn = {1435-8115}, mesh = {Amoebozoa/*classification/*ultrastructure ; Imaging, Three-Dimensional ; Microscopy/*methods ; }, abstract = {Testate amoebae (TA) are a group of free-living protozoa, important in ecology and paleoecology. Testate amoebae taxonomy is mainly based on the morphological features of the shell, as examined by means of light microscopy or (environmental) scanning electron microscopy (SEM/ESEM). We explored the potential applications of confocal laser scanning microscopy (CLSM), two photon excitation microscopy (TPEM), phase contrast, differential interference contrast (DIC Nomarski), and polarization microscopy to visualize TA shells and inner structures of living cells, which is not possible by SEM or environmental SEM. Images captured by CLSM and TPEM were utilized to create three-dimensional (3D) visualizations and to evaluate biovolume inside the shell by stereological methods, to assess the function of TA in ecosystems. This approach broadens the understanding of TA cell and shell morphology, and inner structures including organelles and endosymbionts, with potential implications in taxonomy and ecophysiology.}, }
@article {pmid21091563, year = {2011}, author = {Pinzón, JH and LaJeunesse, TC}, title = {Species delimitation of common reef corals in the genus Pocillopora using nucleotide sequence phylogenies, population genetics and symbiosis ecology.}, journal = {Molecular ecology}, volume = {20}, number = {2}, pages = {311-325}, doi = {10.1111/j.1365-294X.2010.04939.x}, pmid = {21091563}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*classification/*genetics ; Base Sequence ; *Coral Reefs ; DNA, Chloroplast ; DNA, Mitochondrial ; DNA, Ribosomal ; DNA, Ribosomal Spacer ; *Dinoflagellida/classification/genetics/physiology ; Genetic Markers ; Genetic Variation ; Microsatellite Repeats ; Open Reading Frames ; Pacific Ocean ; *Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {Stony corals in the genus Pocillopora are among the most common and widely distributed of Indo-Pacific corals and, as such, are often the subject of physiological and ecological research. In the far Tropical Eastern Pacific (TEP), they are major constituents of shallow coral communities, exhibiting considerable variability in colony shape and branch morphology and marked differences in response to thermal stress. Numerous intermediates occur between morphospecies that may relate to extensive hybridization. The diversity of the Pocillopora genus in the TEP was analysed genetically using nuclear ribosomal (ITS2) and mitochondrial (ORF) sequences, and population genetic markers (seven microsatellite loci). The resident dinoflagellate endosymbiont (Symbiodinium sp.) in each sample was also characterized using sequences of the internal transcribed spacer 2 (ITS2) rDNA and the noncoding region of the chloroplast psbA minicircle. From these analyses, three symbiotically distinct, reproductively isolated, nonhybridizing, evolutionarily divergent animal lineages were identified. Designated types 1, 2 and 3, these groupings were incongruent with traditional morphospecies classification. Type 1 was abundant and widespread throughout the TEP; type 2 was restricted to the Clipperton Atoll; and type 3 was found only in Panama and the Galapagos Islands. Each type harboured a different Symbiodinium'species lineage' in Clade C, and only type 1 associated with the 'stress-tolerant'Symbiodinium glynni (D1). The accurate delineation of species and implementation of a proper taxonomy may profoundly improve our assessment of Pocillopora's reproductive biology, biogeographic distributions, and resilience to climate warming, information that must be considered when planning for the conservation of reef corals.}, }
@article {pmid21080492, year = {2010}, author = {Szklarczyk, R and Huynen, MA}, title = {Mosaic origin of the mitochondrial proteome.}, journal = {Proteomics}, volume = {10}, number = {22}, pages = {4012-4024}, doi = {10.1002/pmic.201000329}, pmid = {21080492}, issn = {1615-9861}, mesh = {Animals ; Biological Evolution ; Humans ; Mice ; Mitochondria/*genetics/metabolism ; *Proteome ; Symbiosis ; }, abstract = {Although the origin of mitochondria from the endosymbiosis of an α-proteobacterium is well established, the nature of the host cell, the metabolic complexity of the endosymbiont and the subsequent evolution of the proto-mitochondrion into all its current appearances are still the subject of discovery and sometimes debate. Here we review what has been inferred about the original composition and subsequent evolution of the mitochondrial proteome and essential mitochondrial systems. The evolutionary mosaic that currently constitutes mitochondrial proteomes contains (i) endosymbiotic proteins (15-45%), (ii) proteins without detectable orthologs outside the eukaryotic lineage (40%), and (iii) proteins that are derived from non-proteobacterial Bacteria, Bacteriophages and Archaea (15%, specifically multiple tRNA-modification proteins). Protein complexes are of endosymbiotic origin, but have greatly expanded with novel eukaryotic proteins; in contrast to mitochondrial enzymes that are both of proteobacterial and non-proteobacterial origin. This disparity is consistent with the complexity hypothesis, which argues that proteins that are a part of large, multi-subunit complexes are unlikely to undergo horizontal gene transfer. We observe that they neither change their subcellular compartments in the course of evolution, even when their genes do.}, }
@article {pmid21079776, year = {2010}, author = {Zhuang, J and Cai, G and Lin, Q and Wu, Z and Xie, L}, title = {A bacteriophage-related chimeric marine virus infecting abalone.}, journal = {PloS one}, volume = {5}, number = {11}, pages = {e13850}, pmid = {21079776}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Animals ; Bacteriophages/classification/*genetics ; DNA, Circular/chemistry/genetics ; DNA, Viral/chemistry/genetics/ultrastructure ; Electrophoresis, Gel, Two-Dimensional ; Ferritins/analysis/genetics ; Gastropoda/*virology ; Genome, Viral/genetics ; Hemocyanins/analogs &amp; derivatives/analysis/genetics/ultrastructure ; Marine Biology ; Microscopy, Electron ; Molecular Sequence Data ; Open Reading Frames/genetics ; Phylogeny ; Seawater/*virology ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Viruses/classification/*genetics/ultrastructure ; }, abstract = {Marine viruses shape microbial communities with the most genetic diversity in the sea by multiple genetic exchanges and infect multiple marine organisms. Here we provide proof from experimental infection that abalone shriveling syndrome-associated virus (AbSV) can cause abalone shriveling syndrome. This malady produces histological necrosis and abnormally modified macromolecules (hemocyanin and ferritin). The AbSV genome is a 34.952-kilobase circular double-stranded DNA, containing putative genes with similarity to bacteriophages, eukaryotic viruses, bacteria and endosymbionts. Of the 28 predicted open reading frames (ORFs), eight ORF-encoded proteins have identifiable functional homologues. The 4 ORF products correspond to a predicted terminase large subunit and an endonuclease in bacteriophage, and both an integrase and an exonuclease from bacteria. The other four proteins are homologous to an endosymbiont-derived helicase, primase, single-stranded binding (SSB) protein, and thymidylate kinase, individually. Additionally, AbSV exhibits a common gene arrangement similar to the majority of bacteriophages. Unique to AbSV, the viral genome also contains genes associated with bacterial outer membrane proteins and may lack the structural protein-encoding ORFs. Genomic characterization of AbSV indicates that it may represent a transitional form of microbial evolution from viruses to bacteria.}, }
@article {pmid21074526, year = {2011}, author = {Pechgit, P and Intarapuk, A and Pinyoowong, D and Bhumiratana, A}, title = {Touchdown-touchup nested PCR for low-copy gene detection of benzimidazole-susceptible Wuchereria bancrofti with a Wolbachia endosymbiont imported by migrant carriers.}, journal = {Experimental parasitology}, volume = {127}, number = {2}, pages = {559-568}, doi = {10.1016/j.exppara.2010.10.022}, pmid = {21074526}, issn = {1090-2449}, mesh = {Adult ; Algorithms ; Animals ; Anthelmintics/pharmacology ; Benzimidazoles/pharmacology ; Carrier State/*diagnosis/ethnology/parasitology/transmission ; DNA, Bacterial/blood ; Elephantiasis, Filarial/*diagnosis/ethnology/transmission ; Female ; Humans ; Male ; Myanmar/ethnology ; Polymerase Chain Reaction ; Symbiosis ; Thailand ; *Transients and Migrants ; Wolbachia/*physiology ; Wuchereria bancrofti/drug effects/genetics/*isolation &amp; purification/microbiology ; Young Adult ; }, abstract = {A novel, sensitive and specific touchdown-touchup nested PCR (TNPCR) technique based on two useful molecular markers, a Wuchereria bancrofti β-tubulin gene involved in benzimidazole susceptibility and a Wolbachia ftsZ gene involved in cell division, was developed to simultaneously detect the parasite W. bancrofti (W1) with its Wolbachia endosymbiont (W2) from both microfilaremic and post-treatment samples of at-risk migrant carriers infected with geographical W. bancrofti isolates. The detection and characterization of authentically low-copy gene-derived amplicons revealed no false positive identifications in amicrofilaremia with or without antigenemia. The W1-TNPCR was 100-fold more sensitive than the W2-TNPCR regardless of the microfilarial DNA isolation method and compared well with the thick blood film and membrane filtration techniques. These locus-specific TNPCRs could also detect Wolbachia-carrying W. bancrofti genotype in addition to a link to benzimidazole sensitivity among those with unknown infection origins that exhibited microfilaremia responsiveness against treatment with diethylcarbamazine plus albendazole. These TNPCR methods can augment the results of microscopic detection of the parasite because these methods enhance DNA isolation and PCR amplification capabilities.}, }
@article {pmid21060838, year = {2010}, author = {Derycke, S and Vanaverbeke, J and Rigaux, A and Backeljau, T and Moens, T}, title = {Exploring the use of cytochrome oxidase c subunit 1 (COI) for DNA barcoding of free-living marine nematodes.}, journal = {PloS one}, volume = {5}, number = {10}, pages = {e13716}, pmid = {21060838}, issn = {1932-6203}, mesh = {Animals ; Base Sequence ; DNA Primers ; DNA, Helminth/*genetics ; Electron Transport Complex IV/*genetics ; *Marine Biology ; Nematoda/enzymology/*genetics ; Phylogeny ; Quality Control ; Species Specificity ; }, abstract = {BACKGROUND: The identification of free-living marine nematodes is difficult because of the paucity of easily scorable diagnostic morphological characters. Consequently, molecular identification tools could solve this problem. Unfortunately, hitherto most of these tools relied on 18S rDNA and 28S rDNA sequences, which often lack sufficient resolution at the species level. In contrast, only a few mitochondrial COI data are available for free-living marine nematodes. Therefore, we investigate the amplification and sequencing success of two partitions of the COI gene, the M1-M6 barcoding region and the I3-M11 partition.<br><br>METHODOLOGY: Both partitions were analysed in 41 nematode species from a wide phylogenetic range. The taxon specific primers for the I3-M11 partition outperformed the universal M1-M6 primers in terms of amplification success (87.8% vs. 65.8%, respectively) and produced a higher number of bidirectional COI sequences (65.8% vs 39.0%, respectively). A threshold value of 5% K2P genetic divergence marked a clear DNA barcoding gap separating intra- and interspecific distances: 99.3% of all interspecific comparisons were >0.05, while 99.5% of all intraspecific comparisons were <0.05 K2P distance.<br><br>CONCLUSION: The I3-M11 partition reliably identifies a wide range of marine nematodes, and our data show the need for a strict scrutiny of the obtained sequences, since contamination, nuclear pseudogenes and endosymbionts may confuse nematode species identification by COI sequences.}, }
@article {pmid21059789, year = {2011}, author = {Kloesges, T and Popa, O and Martin, W and Dagan, T}, title = {Networks of gene sharing among 329 proteobacterial genomes reveal differences in lateral gene transfer frequency at different phylogenetic depths.}, journal = {Molecular biology and evolution}, volume = {28}, number = {2}, pages = {1057-1074}, pmid = {21059789}, issn = {1537-1719}, mesh = {Conjugation, Genetic ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Phylogeny ; Proteobacteria/*classification/*genetics ; }, abstract = {Lateral gene transfer (LGT) is an important mechanism of natural variation among prokaryotes. Over the full course of evolution, most or all of the genes resident in a given prokaryotic genome have been affected by LGT, yet the frequency of LGT can vary greatly across genes and across prokaryotic groups. The proteobacteria are among the most diverse of prokaryotic taxa. The prevalence of LGT in their genome evolution calls for the application of network-based methods instead of tree-based methods to investigate the relationships among these species. Here, we report networks that capture both vertical and horizontal components of evolutionary history among 1,207,272 proteins distributed across 329 sequenced proteobacterial genomes. The network of shared proteins reveals modularity structure that does not correspond to current classification schemes. On the basis of shared protein-coding genes, the five classes of proteobacteria fall into two main modules, one including the alpha-, delta-, and epsilonproteobacteria and the other including beta- and gammaproteobacteria. The first module is stable over different protein identity thresholds. The second shows more plasticity with regard to the sequence conservation of proteins sampled, with the gammaproteobacteria showing the most chameleon-like evolutionary characteristics within the present sample. Using a minimal lateral network approach, we compared LGT rates at different phylogenetic depths. In general, gene evolution by LGT within proteobacteria is very common. At least one LGT event was inferred to have occurred in at least 75% of the protein families. The average LGT rate at the species and class depth is about one LGT event per protein family, the rate doubling at the phylum level to an average of two LGT events per protein family. Hence, our results indicate that the rate of gene acquisition per protein family is similar at the level of species (by recombination) and at the level of classes (by LGT). The frequency of LGT per genome strongly depends on the species lifestyle, with endosymbionts showing far lower LGT frequencies than free-living species. Moreover, the nature of the transferred genes suggests that gene transfer in proteobacteria is frequently mediated by conjugation.}, }
@article {pmid21050430, year = {2010}, author = {Rodriguero, MS and Lanteri, AA and Confalonieri, VA}, title = {Mito-nuclear genetic comparison in a Wolbachia infected weevil: insights on reproductive mode, infection age and evolutionary forces shaping genetic variation.}, journal = {BMC evolutionary biology}, volume = {10}, number = {}, pages = {340}, pmid = {21050430}, issn = {1471-2148}, mesh = {Animals ; DNA, Mitochondrial/genetics ; *Evolution, Molecular ; Female ; Genetic Variation/*genetics ; Male ; Phylogeny ; Weevils/classification/*genetics/*microbiology ; Wolbachia/*pathogenicity ; }, abstract = {BACKGROUND: Maternally inherited endosymbionts like Wolbachia pipientis are in linkage disequilibrium with the mtDNA of their hosts. Therefore, they can induce selective sweeps, decreasing genetic diversity over many generations. This sex ratio distorter, that is involved in the origin of parthenogenesis and other reproductive alterations, infects the parthenogenetic weevil Naupactus cervinus, a serious pest of ornamental and fruit plants.<br><br>RESULTS: Molecular evolution analyses of mitochondrial (COI) and nuclear (ITS1) sequences from 309 individuals of Naupactus cervinus sampled over a broad range of its geographical distribution were carried out. Our results demonstrate lack of recombination in the nuclear fragment, non-random association between nuclear and mitochondrial genomes and the consequent coevolution of both genomes, being an indirect evidence of apomixis. This weevil is infected by a single Wolbachia strain, which could have caused a moderate bottleneck in the invaded population which survived the initial infection.<br><br>CONCLUSIONS: Clonal reproduction and Wolbachia infection induce the coevolution of bacterial, mitochondrial and nuclear genomes. The time elapsed since the Wolbachia invasion would have erased the traces of the demographic crash in the mtDNA, being the nuclear genome the only one that retained the signal of the bottleneck. The amount of genetic change accumulated in the mtDNA and the high prevalence of Wolbachia in all populations of N. cervinus agree with the hypothesis of an ancient infection. Wolbachia probably had great influence in shaping the genetic diversity of N. cervinus. However, it would have not caused the extinction of males, since sexual and asexual infected lineages coexisted until recent times.}, }
@article {pmid21047535, year = {2011}, author = {Iturbe-Ormaetxe, I and Woolfit, M and Rancès, E and Duplouy, A and O'Neill, SL}, title = {A simple protocol to obtain highly pure Wolbachia endosymbiont DNA for genome sequencing.}, journal = {Journal of microbiological methods}, volume = {84}, number = {1}, pages = {134-136}, doi = {10.1016/j.mimet.2010.10.019}, pmid = {21047535}, issn = {1872-8359}, mesh = {Animals ; Culicidae/microbiology ; DNA, Bacterial/*isolation &amp; purification ; Diptera/microbiology ; *Genome, Bacterial ; Molecular Biology/*methods ; Sequence Analysis, DNA ; Wolbachia/*genetics/isolation &amp; purification ; }, abstract = {Most genome sequencing projects using intracellular bacteria face difficulties in obtaining sufficient bacterial DNA free of host contamination. We have developed a simple and rapid protocol to isolate endosymbiont DNA virtually free from fly and mosquito host DNA. We purified DNA from six Wolbachia strains in preparation for genome sequencing using this method, and achieved up to 97% pure Wolbachia sequence, even after using frozen insects. This is a significant improvement for future Wolbachia and other endosymbiont genome projects.}, }
@article {pmid21041111, year = {2010}, author = {Miyagishima, SY and Kabeya, Y}, title = {Chloroplast division: squeezing the photosynthetic captive.}, journal = {Current opinion in microbiology}, volume = {13}, number = {6}, pages = {738-746}, doi = {10.1016/j.mib.2010.10.004}, pmid = {21041111}, issn = {1879-0364}, mesh = {*Cell Division ; Chloroplasts/genetics/*physiology ; Cyanobacteria/genetics/physiology ; Eukaryotic Cells/*physiology ; }, abstract = {Chloroplasts have evolved from a cyanobacterial endosymbiont and have been retained in eukaryotic cells for more than one billion years via chloroplast division and inheritance by daughter cells during cell division. Recent studies revealed that chloroplast division is performed by a large protein complex at the division site, encompassing both the inside and the outside of the two envelope membranes. The division complex has retained a few components of the cyanobacterial division complex to go along with other components supplied by the host cell. On the basis of the information about the division complex, we are beginning to understand how the division complex evolved, and how eukaryotic host cells regulate chloroplast division during proliferation and differentiation.}, }
@article {pmid21040533, year = {2010}, author = {Sirviö, A and Pamilo, P}, title = {Multiple endosymbionts in populations of the ant Formica cinerea.}, journal = {BMC evolutionary biology}, volume = {10}, number = {}, pages = {335}, pmid = {21040533}, issn = {1471-2148}, mesh = {Animals ; Ants/genetics/*microbiology/physiology ; Female ; Male ; Microsatellite Repeats/genetics ; Serratia/genetics/growth &amp; development ; Social Behavior ; Symbiosis/genetics/*physiology ; Wolbachia/genetics/growth &amp; development ; }, abstract = {BACKGROUND: Many insects, including ants, are infected by maternally inherited Wolbachia endosymbiotic bacteria though other secondary endosymbionts have not been reported in ants. It has been suggested that the ability of Wolbachia to invade and remain in an ant population depends on the number of coexisting queens in a colony. We study the genetic and social structure of populations in the ant Formica cinerea which is known to have populations with either monogynous or polygynous colonies. We screen populations for several endosymbiotic bacteria to evaluate the presence of different endosymbionts, possible association between their prevalence and the social structure, and the association between endosymbiont prevalence and genetic differentiation of ant populations.<br><br>RESULTS: We found three endosymbiotic bacteria; 19% of the nests were infected by Wolbachia, 3.8% by Cardinium and 33% by Serratia. There was significant variation among the populations regarding the proportion of nests infected by Serratia, Wolbachia and the pooled set of all the endosymbionts. Some individuals and colonies carried two of the bacteria, the frequency of double infections agreeing with the random expectation. The proportion of infected ants (individuals or colonies) did not correlate significantly with the population level relatedness values. The difference in the prevalence of Wolbachia between population pairs correlated significantly with the genetic distance (microsatellites) of the populations.<br><br>CONCLUSIONS: The discovery of several endosymbionts and co-infections by Wolbachia and Cardinium demonstrate the importance of screening several endosymbionts when evaluating their possible effects on social life and queen-worker conflicts over sex allocation. The low prevalence of Wolbachia in F. cinerea departs from the pattern observed in many other Formica ants in which all workers have been infected. It is likely that the strain of Wolbachia in F. cinerea differs from those in other Formica species. The correlation between the difference in Wolbachia prevalence and the pair-wise genetic distance of populations suggests that spreading of the bacteria is restricted by the isolation of the host populations.}, }
@article {pmid20970377, year = {2010}, author = {Esteban, GF and Fenchel, T and Finlay, BJ}, title = {Mixotrophy in ciliates.}, journal = {Protist}, volume = {161}, number = {5}, pages = {621-641}, doi = {10.1016/j.protis.2010.08.002}, pmid = {20970377}, issn = {1618-0941}, mesh = {Aerobiosis ; Bacterial Physiological Phenomena ; Chlorella/physiology ; Ciliophora/classification/cytology/*physiology ; *Phagocytosis ; *Photosynthesis ; Symbiosis ; }, abstract = {Mixotrophy is the occurrence of phagotrophy and phototrophy in the same organism. In ciliates the intracellular phototroph can be unicellular green algae (zoochlorellae), dinoflagellates (zooxanthellae), cryptomonads or sequestered chloroplasts from ingested algae. An intermediate mixotrophic mechanism is that where the phagotroph ingests algal cells, maintains them intact and functional in the cytoplasm for some time, but the algae are afterwards digested. This seems to occur in some species of Mesodinium. Ciliates with phototrophic endosymbionts have evolved independently in marine and freshwater habitats. The enslaved algal cells or chloroplasts provide host cells with organic matter. Mixotrophs flourish in oxygen-rich, but also in micro-aerobic waters and in the complete absence of oxygen. In the latter case, the aerobic host retains aerobic metabolism, sustained by the oxygen produced by the phototrophic endosymbionts or the sequestered chloroplasts. Mixotrophic ciliates can attain spectacular abundances in some habitats, and entirely dominate the ciliate community.}, }
@article {pmid20961376, year = {2010}, author = {White, J and Mirleau, P and Danchin, E and Mulard, H and Hatch, SA and Heeb, P and Wagner, RH}, title = {Sexually transmitted bacteria affect female cloacal assemblages in a wild bird.}, journal = {Ecology letters}, volume = {13}, number = {12}, pages = {1515-1524}, pmid = {20961376}, issn = {1461-0248}, support = {P 20401/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Bacteria/genetics/isolation &amp; purification ; *Bacterial Physiological Phenomena ; *Biodiversity ; Bird Diseases/microbiology/*transmission ; Charadriiformes/microbiology/*physiology ; Cloaca/*microbiology ; DNA, Ribosomal Spacer/genetics ; Female ; Male ; Sexually Transmitted Diseases, Bacterial/microbiology/transmission ; }, abstract = {Ecology Letters (2010) 13: 1515-1524 ABSTRACT: Sexual transmission is an important mode of disease propagation, yet its mechanisms remain largely unknown in wild populations. Birds comprise an important model for studying sexually transmitted microbes because their cloaca provides a potential for both gastrointestinal pathogens and endosymbionts to become incorporated into ejaculates. We experimentally demonstrate in a wild population of kittiwakes (Rissa tridactyla) that bacteria are transmitted during copulation and affect the composition and diversity of female bacterial communities. We used an anti-insemination device attached to males in combination with a molecular technique (automated ribosomal intergenic spacer analysis) that describes bacterial communities. After inseminations were experimentally blocked, the cloacal communities of mates became increasingly dissimilar. Moreover, female cloacal diversity decreased and the extinction of mate-shared bacteria increased, indicating that female cloacal assemblages revert to their pre-copulatory state and that the cloaca comprises a resilient microbial ecosystem.}, }
@article {pmid20958984, year = {2010}, author = {Felsner, G and Sommer, MS and Maier, UG}, title = {The physical and functional borders of transit peptide-like sequences in secondary endosymbionts.}, journal = {BMC plant biology}, volume = {10}, number = {}, pages = {223}, pmid = {20958984}, issn = {1471-2229}, mesh = {Biolistics ; Carrier Proteins/genetics/metabolism ; Diatoms/cytology/*metabolism ; Endoplasmic Reticulum/metabolism ; Green Fluorescent Proteins/genetics/metabolism ; Intracellular Membranes/metabolism ; Microscopy, Confocal ; Mutation ; Peptides/genetics/metabolism ; Plastids/*metabolism ; Protein Precursors/genetics/*metabolism ; Protein Sorting Signals/genetics ; Protein Transport ; Recombinant Fusion Proteins/genetics/*metabolism ; Symbiosis ; }, abstract = {BACKGROUND: Plastids rely on protein supply by their host cells. In plastids surrounded by two membranes (primary plastids) targeting of these proteins is facilitated by an N-terminal targeting signal, the transit peptide. In secondary plastids (surrounded by three or four membranes), transit peptide-like regions are an essential part of a bipartite topogenic signal sequence (BTS), and generally found adjacent to a N-terminally located signal peptide of the plastid pre-proteins. As in primary plastids, for which no wealth of functional information about transit peptide features exists, the transit peptide-like regions used for import into secondary ones show some common features only, which are also poorly characterized.<br><br>RESULTS: We modified the BTS (in the transit peptide-like region) of the plastid precursor fucoxanthin-chlorophyll a/c binding protein D (FcpD) fused to GFP as model substrate for the characterization of pre-protein import into the secondary plastids of diatoms. Thereby we show that (i) pre-protein import is highly charge dependent. Positive net charge is necessary for transport across the plastid envelope, but not across the periplastid membrane. Acidic net charge perturbs pre-protein import within the ER. Moreover, we show that (ii) the mature domain of the pre-protein can provide intrinsic transit peptide functions.<br><br>CONCLUSIONS: Our results indicate important characteristics of targeting signals of proteins imported into secondary plastids surrounded by four membranes. In addition, we show a self-targeting mechanism, in which the mature protein domain contributes to the transit peptide function. Thus, this phenomenon lowers the demand for pre-sequences evolved during the course of endosymbiosis.}, }
@article {pmid20957033, year = {2010}, author = {Kuriwada, T and Hosokawa, T and Kumano, N and Shiromoto, K and Haraguchi, D and Fukatsu, T}, title = {Biological role of Nardonella endosymbiont in its weevil host.}, journal = {PloS one}, volume = {5}, number = {10}, pages = {}, pmid = {20957033}, issn = {1932-6203}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Base Sequence ; DNA Primers ; *Host-Pathogen Interactions ; Ipomoea batatas/parasitology ; Polymerase Chain Reaction ; *Symbiosis ; Weevils/*parasitology ; }, abstract = {Weevils constitute the most species-rich animal group with over 60,000 described species, many of which possess specialized symbiotic organs and harbor bacterial endosymbionts. Among the diverse microbial associates of weevils, Nardonella spp. represent the most ancient and widespread endosymbiont lineage, having co-speciated with the host weevils for over 125 million years. Thus far, however, no empirical work on the role of Nardonella for weevil biology has been reported. Here we investigated the biological role of the Nardonella endosymbiont for the West Indian sweet potato weevil, Euscepes postfasciatus. This insect is an experimentally tractable pest insect that can easily be reared on a natural diet of sweet potato root as well as on an agar-based artificial diet. By larval feeding on an antibiotic-containing artificial diet, Nardonella infection was effectively eliminated from the treated insects. The antibiotic-treated insects exhibited significantly lighter body weight and lower growth rate than the control insects. Then, the antibiotic-treated insects and the control insects were respectively allowed to mate and oviposit on fresh sweet potatoes without the antibiotic. The offspring of the antibiotic-treated insects, which were all Nardonella-negative, exhibited significantly lighter body weight, smaller body size, lower growth rate and paler body color in comparison with the offspring of the control insects, which were all Nardonella-positive. In conclusion, the Nardonella endosymbiont is involved in normal growth and development of the host weevil. The biological role of the endosymbiont probably underlies the long-lasting host-symbiont co-speciation in the evolutionary course of weevils.}, }
@article {pmid20950111, year = {2010}, author = {Jones, SR and Prosperi-Porta, G and LaPatra, SE}, title = {First isolation of Pseudocohnilembus persalinus (Ciliophora: Scuticociliatida) from freshwater-reared rainbow trout, Oncorhynchus mykiss.}, journal = {The Journal of parasitology}, volume = {96}, number = {5}, pages = {1014-1016}, doi = {10.1645/GE-2500.1}, pmid = {20950111}, issn = {1937-2345}, mesh = {Animals ; Ciliophora Infections/parasitology/*veterinary ; DNA, Mitochondrial/chemistry ; DNA, Protozoan/chemistry ; DNA, Ribosomal/chemistry ; Electron Transport Complex IV/genetics ; Female ; Fish Diseases/*parasitology ; Fresh Water ; Molecular Sequence Data ; Oligohymenophorea/*classification/genetics/isolation &amp; purification/ultrastructure ; Oncorhynchus mykiss/*parasitology ; Ovary/parasitology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 18S/genetics ; Sequence Alignment/veterinary ; Symbiosis ; }, abstract = {Ciliated protists were isolated from the ovarian fluid of apparently healthy adult rainbow trout (Oncorhynchus mykiss) maintained in freshwater. The organism was identified as Pseudocohnilembus persalinus based on morphometric and morphological analysis of silver-stained specimens obtained from culture and on analysis of ribosomal RNA gene sequences. The cytochrome c oxidase subunit 1 gene sequence of this organism also was characterized. This ciliate has been reported previously as free living only in saline environments and as an endosymbiont in a marine teleost, the olive flounder (Paralichthys olivaceus). A cyst-like stage may have facilitated the novel occurrence of this organism as an endosymbiont in rainbow trout.}, }
@article {pmid20949086, year = {2010}, author = {Jiroutová, K and Kořený, L and Bowler, C and Oborník, M}, title = {A gene in the process of endosymbiotic transfer.}, journal = {PloS one}, volume = {5}, number = {10}, pages = {e13234}, pmid = {20949086}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Cell Nucleus/genetics ; Diatoms/*genetics ; Gene Transfer Techniques ; Molecular Sequence Data ; Plastids/genetics ; Proteins/chemistry/genetics ; Sequence Homology, Amino Acid ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: The endosymbiotic birth of organelles is accompanied by massive transfer of endosymbiont genes to the eukaryotic host nucleus. In the centric diatom Thalassiosira pseudonana the Psb28 protein is encoded in the plastid genome while a second version is nuclear-encoded and possesses a bipartite N-terminal presequence necessary to target the protein into the diatom complex plastid. Thus it can represent a gene captured during endosymbiotic gene transfer.<br><br>To specify the origin of nuclear- and plastid-encoded Psb28 in T. pseudonana we have performed extensive phylogenetic analyses of both mentioned genes. We have also experimentally tested the intracellular location of the nuclear-encoded Psb28 protein (nuPsb28) through transformation of the diatom Phaeodactylum tricornutum with the gene in question fused to EYFP.<br><br>CONCLUSIONS/SIGNIFICANCE: We show here that both versions of the psb28 gene in T. pseudonana are transcribed. We also provide experimental evidence for successful targeting of the nuPsb28 fused with EYFP to the diatom complex plastid. Extensive phylogenetic analyses demonstrate that nucleotide composition of the analyzed genes deeply influences the tree topology and that appropriate methods designed to deal with a compositional bias of the sequences and the long branch attraction artefact (LBA) need to be used to overcome this obstacle. We propose that nuclear psb28 in T. pseudonana is a duplicate of a plastid localized version, and that it has been transferred from its endosymbiont.}, }
@article {pmid20949079, year = {2010}, author = {Kambris, Z and Blagborough, AM and Pinto, SB and Blagrove, MS and Godfray, HC and Sinden, RE and Sinkins, SP}, title = {Wolbachia stimulates immune gene expression and inhibits plasmodium development in Anopheles gambiae.}, journal = {PLoS pathogens}, volume = {6}, number = {10}, pages = {e1001143}, pmid = {20949079}, issn = {1553-7374}, support = {/WT_/Wellcome Trust/United Kingdom ; 079059/WT_/Wellcome Trust/United Kingdom ; LDAD_P15820/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Animals, Genetically Modified ; Anopheles/*immunology/microbiology/parasitology ; Antibiosis/genetics/immunology ; Communicable Disease Control/methods ; Female ; Gene Expression Regulation/immunology ; Gene Knockdown Techniques ; Host-Parasite Interactions/genetics/immunology ; Immunity, Innate/*genetics ; Insect Proteins/antagonists &amp; inhibitors/genetics/physiology ; Malaria/immunology/prevention &amp; control ; Plasmodium/*growth &amp; development/*immunology/pathogenicity ; Up-Regulation/genetics ; Wolbachia/genetics/*physiology ; }, abstract = {The over-replicating wMelPop strain of the endosymbiont Wolbachia pipientis has recently been shown to be capable of inducing immune upregulation and inhibition of pathogen transmission in Aedes aegypti mosquitoes. In order to examine whether comparable effects would be seen in the malaria vector Anopheles gambiae, transient somatic infections of wMelPop were created by intrathoracic inoculation. Upregulation of six selected immune genes was observed compared to controls, at least two of which (LRIM1 and TEP1) influence the development of malaria parasites. A stably infected An. gambiae cell line also showed increased expression of malaria-related immune genes. Highly significant reductions in Plasmodium infection intensity were observed in the wMelPop-infected cohort, and using gene knockdown, evidence for the role of TEP1 in this phenotype was obtained. Comparing the levels of upregulation in somatic and stably inherited wMelPop infections in Ae. aegypti revealed that levels of upregulation were lower in the somatic infections than in the stably transinfected line; inhibition of development of Brugia filarial nematodes was nevertheless observed in the somatic wMelPop infected females. Thus we consider that the effects observed in An. gambiae are also likely to be more pronounced if stably inherited wMelPop transinfections can be created, and that somatic infections of Wolbachia provide a useful model for examining effects on pathogen development or dissemination. The data are discussed with respect to the comparative effects on malaria vectorial capacity of life shortening and direct inhibition of Plasmodium development that can be produced by Wolbachia.}, }
@article {pmid20946650, year = {2010}, author = {Johnston, KL and Wu, B and Guimarães, A and Ford, L and Slatko, BE and Taylor, MJ}, title = {Lipoprotein biosynthesis as a target for anti-Wolbachia treatment of filarial nematodes.}, journal = {Parasites &amp; vectors}, volume = {3}, number = {}, pages = {99}, pmid = {20946650}, issn = {1756-3305}, abstract = {BACKGROUND: Lymphatic filariasis and onchocerciasis are debilitating diseases caused by filarial nematodes. Disease pathogenesis is induced by inflammatory responses following the death of the parasite. Wolbachia endosymbionts of filariae are potent inducers of innate and adaptive inflammation and bacterial lipoproteins have been identified as the ligands that bind toll-like receptors (TLR) 2 and TLR6. Lipoproteins are important structural and functional components of bacteria and therefore enzymes involved in Wolbachia lipoprotein biosynthesis are potential chemotherapeutic targets.<br><br>RESULTS: Globomycin, a signal peptidase II (LspA) inhibitor, has activity against Gram-negative bacteria and a putative lspA gene has been identified from the Wolbachia genome of Brugia malayi (wBm). The amino acids required for function are strictly conserved and functionality was verified by complementation tests in a temperature-sensitive Escherichia coli lspA mutant. Also, transformation of wild type E. coli with Wolbachia lspA conferred significant globomycin resistance. A cell-based screen has been developed utilizing a Wolbachia-containing Aedes albopictus cell line to assay novel compounds active against Wolbachia. Globomycin was screened using this assay, which resulted in a dose-dependent reduction in Wolbachia load. Furthermore, globomycin was also effective in reducing the motility and viability of adult B. malayi in vitro.<br><br>CONCLUSIONS: These studies validate lipoprotein biosynthesis as a target in an organism for which no genetic tools are available. Further studies to evaluate drugs targeting this pathway are underway as part of the A-WOL drug discovery and development program.}, }
@article {pmid20934378, year = {2011}, author = {Escalera, L and Reguera, B and Takishita, K and Yoshimatsu, S and Koike, K and Koike, K}, title = {Cyanobacterial endosymbionts in the benthic dinoflagellate Sinophysis canaliculata (Dinophysiales, Dinophyceae).}, journal = {Protist}, volume = {162}, number = {2}, pages = {304-314}, doi = {10.1016/j.protis.2010.07.003}, pmid = {20934378}, issn = {1618-0941}, mesh = {Cyanobacteria/classification/genetics/isolation &amp; purification/*physiology ; Dinoflagellida/*microbiology/*physiology ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; }, abstract = {Photosynthetic dinoflagellates possess a great diversity of plastids that have been acquired through successful serial endosymbiosis. The peridinin-containing plastid in dinoflagellates is canonical, but many other types are known within this group. Within the Dinophysiales, several species of Dinophysis contain plastids, derived from cryptophytes or haptophytes. In this work, the presence of numerous intracellular cyanobacteria-like microorganisms compartmentalized by a separate membrane is reported for the first time within the benthic dinophysoid dinoflagellate Sinophysis canaliculata Quod et al., a species from a genus morphologically close to Dinophysis. Although the contribution of these cyanobacterial endosymbionts to S. canaliculata is still unknown, this finding suggests a possible undergoing primary endosymbiosis in a dinoflagellate.}, }
@article {pmid20874732, year = {2011}, author = {Pröschold, T and Darienko, T and Silva, PC and Reisser, W and Krienitz, L}, title = {The systematics of Zoochlorella revisited employing an integrative approach.}, journal = {Environmental microbiology}, volume = {13}, number = {2}, pages = {350-364}, doi = {10.1111/j.1462-2920.2010.02333.x}, pmid = {20874732}, issn = {1462-2920}, support = {G0900740/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Base Sequence ; Chlorella/*classification/*genetics ; DNA, Plant/genetics ; DNA, Ribosomal Spacer/genetics ; Genes, rRNA ; Nucleic Acid Conformation ; Paramecium/microbiology ; *Phylogeny ; Symbiosis ; }, abstract = {Symbiosis of green algae with protozoa and invertebrates has been studied for more than 100 years. Endosymbiotic green algae are widely distributed in ciliates (e.g. Paramecium, Stentor, Climacostomum, Coleps, Euplotes), heliozoa (e.g. Acanthocystis) and invertebrates (e.g. Hydra, Spongilla), and have traditionally been identified as named or unnamed species of Chlorella Beij. or Zoochlorella K. Brandt or referred to as Chlorella-like algae or zoochlorellae. We studied 17 strains of endosymbionts isolated from various hosts and geographical localities using an integrative approach (nuclear encoded small subunit and internal transcribed spacer regions of rRNA gene sequences including their secondary structures, morphology, physiology and virus sensitivity). Phylogenetic analyses have revealed them to be polyphyletic. The strains examined belong to five independent clades within the Trebouxiophyceae (Choricystis-, Elliptochloris-, Auxenochlorella- and Chlorella-clades) and Chlorophyceae (Scenedesmus-clade). The most studied host organism, Paramecium bursaria, harbours endosymbionts representing at least five different species. On the basis of our results, we propose a taxonomic revision of endosymbiotic 'Chlorella'-like green algae. Zoochlorella conductrix K. Brandt is transferred to Micractinium Fresen. and Zoochlorella parasitica K. Brandt to Choricystis (Skuja) Fott. It was shown that Choricystis minor (Skuja) Fott, the generitype, is a later heterotypic synonym of Choricystis parasitica (K. Brandt) comb. nov. A new species, Chlorella heliozoae, is proposed to accommodate the endosymbiont of Acanthocystis turfacea.}, }
@article {pmid20870890, year = {2011}, author = {Sabri, A and Leroy, P and Haubruge, E and Hance, T and Frère, I and Destain, J and Thonart, P}, title = {Isolation, pure culture and characterization of Serratia symbiotica sp. nov., the R-type of secondary endosymbiont of the black bean aphid Aphis fabae.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {61}, number = {Pt 9}, pages = {2081-2088}, doi = {10.1099/ijs.0.024133-0}, pmid = {20870890}, issn = {1466-5034}, mesh = {Aerobiosis ; Animals ; Aphids/*microbiology ; Bacterial Typing Techniques ; Cluster Analysis ; Culture Media/chemistry ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Fatty Acids/analysis ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Serratia/*classification/genetics/*isolation &amp; purification/physiology ; Symbiosis ; }, abstract = {An intracellular symbiotic bacterium was isolated from the flora of a natural clone of the black bean aphid Aphis fabae. The strain was able to grow freely in aerobic conditions on a rich medium containing 1 % of each of the following substrates: glucose, yeast extract and casein peptone. Pure culture was achieved through the use of solid-phase culture on the same medium and the strain was designated CWBI-2.3(T). 16S rRNA gene sequence analysis revealed that strain CWBI-2.3(T) was a member of the class Gammaproteobacteria, having high sequence similarity (>99 %) with 'Candidatus Serratia symbiotica', the R-type of secondary endosymbiont that is found in several aphid species. As strain CWBI-2.3(T) (= LMG 25624(T) = DSM 23270(T)) was the first R-type symbiont to be isolated and characterized, it was designated as the type strain of Serratia symbiotica sp. nov.}, }
@article {pmid20865129, year = {2010}, author = {Motta, MC and Catta-Preta, CM and Schenkman, S and de Azevedo Martins, AC and Miranda, K and de Souza, W and Elias, MC}, title = {The bacterium endosymbiont of Crithidia deanei undergoes coordinated division with the host cell nucleus.}, journal = {PloS one}, volume = {5}, number = {8}, pages = {e12415}, pmid = {20865129}, issn = {1932-6203}, mesh = {Bacteria/*cytology/genetics ; Bacterial Physiological Phenomena ; *Cell Division ; Cell Nucleus/*microbiology ; Crithidia/*cytology/*microbiology/physiology ; DNA Replication ; *Symbiosis ; }, abstract = {In trypanosomatids, cell division involves morphological changes and requires coordinated replication and segregation of the nucleus, kinetoplast and flagellum. In endosymbiont-containing trypanosomatids, like Crithidia deanei, this process is more complex, as each daughter cell contains only a single symbiotic bacterium, indicating that the prokaryote must replicate synchronically with the host protozoan. In this study, we used light and electron microscopy combined with three-dimensional reconstruction approaches to observe the endosymbiont shape and division during C. deanei cell cycle. We found that the bacterium replicates before the basal body and kinetoplast segregations and that the nucleus is the last organelle to divide, before cytokinesis. In addition, the endosymbiont is usually found close to the host cell nucleus, presenting different shapes during the protozoan cell cycle. Considering that the endosymbiosis in trypanosomatids is a mutualistic relationship, which resembles organelle acquisition during evolution, these findings establish an excellent model for the understanding of mechanisms related with the establishment of organelles in eukaryotic cells.}, }
@article {pmid20855945, year = {2010}, author = {Blatch, SA and Meyer, KW and Harrison, JF}, title = {Effects of dietary folic acid level and symbiotic folate production on fitness and development in the fruit fly Drosophila melanogaster.}, journal = {Fly}, volume = {4}, number = {4}, pages = {312-319}, doi = {10.4161/fly.4.4.13258}, pmid = {20855945}, issn = {1933-6942}, mesh = {Animals ; Drosophila melanogaster/*drug effects/growth &amp; development/microbiology ; Folic Acid/biosynthesis/*pharmacology ; Larva/drug effects/growth &amp; development/microbiology ; Symbiosis ; Wolbachia/isolation &amp; purification ; }, abstract = {Folic acid is a vitamin for probably all animals. When converted to folate forms, it is used in DNA synthesis and amino acid metabolism. Literature suggests insects must consume folates, folates do not affect others, is a toxin for some, and that a few insects synthesize it. It has been reported that Drosophila melanogaster does not consistently need dietary folate because it can synthesize it. This seems unlikely since animals generally lack this ability. More likely, folates thought to have been made by the fly came from microbial symbionts. We aimed to clarify how dietary folic acid affects fitness and development in fruit flies and whether flies may receive folates from microbial symbionts. We found larvae were more viable and developed faster with increasing dietary folic acid, with the surprising exception that larvae fed nearly-zero folic acid developed faster. Their body folate levels did not significantly differ from those that consumed up to 600 times more folic acid. However, these flies fed little folate only achieved normal body folate levels and development times when antibiotics were excluded from the diet. When flies consumed near-zero folates with antibiotics, their body folate levels decreased and development was prolonged. An assay for the endosymbiont Wolbachia in flies used to generate the experimental flies did not show presence of these bacteria. Our data suggest D. melanogaster can harbor unknown bacterial symbiont(s) that provide essential folates to their host when it is scarce in the diet, allowing the fruit fly to maintain growth and development.}, }
@article {pmid20851962, year = {2010}, author = {Gruwell, ME and Hardy, NB and Gullan, PJ and Dittmar, K}, title = {Evolutionary relationships among primary endosymbionts of the mealybug subfamily phenacoccinae (hemiptera: Coccoidea: Pseudococcidae).}, journal = {Applied and environmental microbiology}, volume = {76}, number = {22}, pages = {7521-7525}, pmid = {20851962}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*genetics ; *Bacterial Physiological Phenomena ; *Biodiversity ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Hemiptera/*microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Mealybugs (Coccoidea: Pseudococcidae) are sap-sucking plant parasites that harbor bacterial endosymbionts within specialized organs. Previous studies have identified two subfamilies, Pseudococcinae and Phenacoccinae, within mealybugs and determined the primary endosymbionts (P-endosymbionts) of the Pseudococcinae to be Betaproteobacteria ("Candidatus Tremblaya princeps") containing Gammaproteobacteria secondary symbionts. Here, the P-endosymbionts of phenacoccine mealybugs are characterized based on 16S rRNA from the bacteria of 20 species of phenacoccine mealybugs and four outgroup Puto species (Coccoidea: Putoidae) and aligned to more than 100 published 16S rRNA sequences from symbiotic and free-living bacteria. Phylogenetic analyses recovered three separate lineages of bacteria from the Phenacoccinae, and these are considered to be the P-endosymbionts of their respective mealybug hosts, with those from (i) the mealybug genus Rastrococcus belonging to the Bacteroidetes, (ii) the subterranean mealybugs, tribe Rhizoecini, also within Bacteroidetes, in a clade sister to cockroach endosymbionts (Blattabacterium), and (iii) the remaining Phenacoccinae within the Betaproteobacteria, forming a well-supported sister group to "Candidatus Tremblaya princeps." Names are proposed for two strongly supported lineages: "Candidatus Brownia rhizoecola" for P-endosymbionts of Rhizoecini and "Candidatus Tremblaya phenacola" for P-endosymbionts of Phenacoccinae excluding Rastrococcus and Rhizoecini. Rates of nucleotide substitution among lineages of Tremblaya were inferred to be significantly faster than those of free-living Betaproteobacteria. Analyses also recovered a clade of Gammaproteobacteria, sister to the P-endosymbiont lineage of aphids ("Candidatus Buchnera aphidicola"), containing the endosymbionts of Putoidae, the secondary endosymbionts of pseudococcine mealybugs, and the endosymbionts of several other insect groups.}, }
@article {pmid20848156, year = {2011}, author = {Jacobs, J and Kück, U}, title = {Function of chloroplast RNA-binding proteins.}, journal = {Cellular and molecular life sciences : CMLS}, volume = {68}, number = {5}, pages = {735-748}, pmid = {20848156}, issn = {1420-9071}, mesh = {Amino Acid Motifs ; Binding Sites ; Chloroplasts/*metabolism ; DNA, Chloroplast ; Plant Proteins/chemistry/*physiology ; Protein Structure, Tertiary ; RNA Editing ; RNA Splicing ; RNA Stability ; RNA, Plant/chemistry/metabolism ; RNA-Binding Proteins/chemistry/*physiology ; }, abstract = {Chloroplasts are eukaryotic organelles which represent evolutionary chimera with proteins that have been derived from either a prokaryotic endosymbiont or a eukaryotic host. Chloroplast gene expression starts with transcription of RNA and is followed by multiple post-transcriptional processes which are mediated mainly by an as yet unknown number of RNA-binding proteins. Here, we review the literature to date on the structure and function of these chloroplast RNA-binding proteins. For example, the functional protein domains involved in RNA binding, such as the RNA-recognition motifs, the chloroplast RNA-splicing and ribosome maturation domains, and the pentatricopeptide-repeat motifs, are summarized. We also describe biochemical and forward genetic approaches that led to the identification of proteins modifying RNA stability or carrying out RNA splicing or editing. Such data will greatly contribute to a better understanding of the biogenesis of a unique organelle found in all photosynthetic organisms.}, }
@article {pmid20838423, year = {2010}, author = {Ciccolella, CO and Raynard, NA and Mei, JH and Church, DC and Ludwig, RA}, title = {Symbiotic legume nodules employ both rhizobial exo- and endo-hydrogenases to recycle hydrogen produced by nitrogen fixation.}, journal = {PloS one}, volume = {5}, number = {8}, pages = {e12094}, pmid = {20838423}, issn = {1932-6203}, mesh = {Azorhizobium/*metabolism ; Hydrogen/*metabolism ; Hydrogenase/*metabolism ; *Nitrogen Fixation ; Root Nodules, Plant/*metabolism ; Sesbania/*metabolism ; *Symbiosis ; }, abstract = {BACKGROUND: In symbiotic legume nodules, endosymbiotic rhizobia (bacteroids) fix atmospheric N(2), an ATP-dependent catalytic process yielding stoichiometric ammonium and hydrogen gas (H(2)). While in most legume nodules this H(2) is quantitatively evolved, which loss drains metabolic energy, certain bacteroid strains employ uptake hydrogenase activity and thus evolve little or no H(2). Rather, endogenous H(2) is efficiently respired at the expense of O(2), driving oxidative phosphorylation, recouping ATP used for H(2) production, and increasing the efficiency of symbiotic nodule N(2) fixation. In many ensuing investigations since its discovery as a physiological process, bacteroid uptake hydrogenase activity has been presumed a single entity.<br><br>Azorhizobium caulinodans, the nodule endosymbiont of Sesbania rostrata stems and roots, possesses both orthodox respiratory (exo-)hydrogenase and novel (endo-)hydrogenase activities. These two respiratory hydrogenases are structurally quite distinct and encoded by disparate, unlinked gene-sets. As shown here, in S. rostrata symbiotic nodules, haploid A. caulinodans bacteroids carrying single knockout alleles in either exo- or-endo-hydrogenase structural genes, like the wild-type parent, evolve no detectable H(2) and thus are fully competent for endogenous H(2) recycling. Whereas, nodules formed with A. caulinodans exo-, endo-hydrogenase double-mutants evolve endogenous H(2) quantitatively and thus suffer complete loss of H(2) recycling capability. More generally, from bioinformatic analyses, diazotrophic microaerophiles, including rhizobia, which respire H(2) may carry both exo- and endo-hydrogenase gene-sets.<br><br>CONCLUSIONS/SIGNIFICANCE: In symbiotic S. rostrata nodules, A. caulinodans bacteroids can use either respiratory hydrogenase to recycle endogenous H(2) produced by N(2) fixation. Thus, H(2) recycling by symbiotic legume nodules may involve multiple respiratory hydrogenases.}, }
@article {pmid20836845, year = {2010}, author = {Raupach, MJ and Astrin, JJ and Hannig, K and Peters, MK and Stoeckle, MY and Wägele, JW}, title = {Molecular species identification of Central European ground beetles (Coleoptera: Carabidae) using nuclear rDNA expansion segments and DNA barcodes.}, journal = {Frontiers in zoology}, volume = {7}, number = {}, pages = {26}, pmid = {20836845}, issn = {1742-9994}, abstract = {BACKGROUND: The identification of vast numbers of unknown organisms using DNA sequences becomes more and more important in ecological and biodiversity studies. In this context, a fragment of the mitochondrial cytochrome c oxidase I (COI) gene has been proposed as standard DNA barcoding marker for the identification of organisms. Limitations of the COI barcoding approach can arise from its single-locus identification system, the effect of introgression events, incomplete lineage sorting, numts, heteroplasmy and maternal inheritance of intracellular endosymbionts. Consequently, the analysis of a supplementary nuclear marker system could be advantageous.<br><br>RESULTS: We tested the effectiveness of the COI barcoding region and of three nuclear ribosomal expansion segments in discriminating ground beetles of Central Europe, a diverse and well-studied invertebrate taxon. As nuclear markers we determined the 18S rDNA: V4, 18S rDNA: V7 and 28S rDNA: D3 expansion segments for 344 specimens of 75 species. Seventy-three species (97%) of the analysed species could be accurately identified using COI, while the combined approach of all three nuclear markers provided resolution among 71 (95%) of the studied Carabidae.<br><br>CONCLUSION: Our results confirm that the analysed nuclear ribosomal expansion segments in combination constitute a valuable and efficient supplement for classical DNA barcoding to avoid potential pitfalls when only mitochondrial data are being used. We also demonstrate the high potential of COI barcodes for the identification of even closely related carabid species.}, }
@article {pmid20824657, year = {2010}, author = {Braschi, E and McBride, HM}, title = {Mitochondria and the culture of the Borg: understanding the integration of mitochondrial function within the reticulum, the cell, and the organism.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {32}, number = {11}, pages = {958-966}, pmid = {20824657}, issn = {1521-1878}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Animals ; Disease ; Humans ; Mitochondria/*metabolism ; *Signal Transduction ; }, abstract = {As endosymbionts, the mitochondria are unique among organelles. This review provides insights into mitochondrial behavior and introduces the idea of a unified collective, an interconnected reticulum reminiscent of the Borg, a fictional humanoid species from the Star Trek television series whereby decisions are made within their network (or "hive"), linked to signaling cascades that coordinate the cross-talk between mitochondrial and cellular processes ("subspace domain"). Similarly, mitochondrial dynamics are determined by two distinct processes, namely the local regulation of fission/fusion and the global control of their behavior through cellular signaling pathways. Indeed, decisions within the hive provide each mitochondrial unit with autonomous control of their own degradation, whereby mitochondrial fusion is inactivated and they become substrates for autophagy. Decisions within the subspace domain couple signaling pathways involved in the functional integration of mitochondria with complex cellular transitions, including developmental cues, mitosis, and apoptosis.}, }
@article {pmid20821176, year = {2011}, author = {Rosic, NN and Pernice, M and Dove, S and Dunn, S and Hoegh-Guldberg, O}, title = {Gene expression profiles of cytosolic heat shock proteins Hsp70 and Hsp90 from symbiotic dinoflagellates in response to thermal stress: possible implications for coral bleaching.}, journal = {Cell stress &amp; chaperones}, volume = {16}, number = {1}, pages = {69-80}, pmid = {20821176}, issn = {1466-1268}, mesh = {Animals ; Anthozoa/genetics/*metabolism ; Base Sequence ; Dinoflagellida/genetics/*metabolism ; *Gene Expression Profiling ; HSP70 Heat-Shock Proteins/classification/genetics/*metabolism ; HSP90 Heat-Shock Proteins/classification/genetics/*metabolism ; Molecular Sequence Data ; Phylogeny ; Symbiosis ; Temperature ; Time Factors ; }, abstract = {Unicellular photosynthetic dinoflagellates of the genus Symbiodinium are the most common endosymbionts of reef-building scleractinian corals, living in a symbiotic partnership known to be highly susceptible to environmental changes such as hyperthermic stress. In this study, we identified members of two major heat shock proteins (HSPs) families, Hsp70 and Hsp90, in Symbiodinium sp. (clade C) with full-length sequences that showed the highest similarity and evolutionary relationship with other known HSPs from dinoflagellate protists. Regulation of HSPs gene expression was examined in samples of the scleractinian coral Acropora millepora subjected to elevated temperatures progressively over 18 h (fast) and 120 h (gradual thermal stress). Moderate to severe heat stress at 26°C and 29°C (+3°C and +6°C above average sea temperature) resulted in an increase in algal Hsp70 gene expression from 39% to 57%, while extreme heat stress (+9°C) reduced Hsp70 transcript abundance by 60% (after 18 h) and 70% (after 120 h). Elevated temperatures decreased an Hsp90 expression under both rapid and gradual heat stress scenarios. Comparable Hsp70 and Hsp90 gene expression patterns were observed in Symbiodinium cultures and in hospite, indicating their independent regulation from the host. Differential gene expression profiles observed for Hsp70 and Hsp90 suggests diverse roles of these molecular chaperones during heat stress response. Reduced expression of the Hsp90 gene under heat stress can indicate a reduced role in inhibiting the heat shock transcription factor which may lead to activation of heat-inducible genes and heat acclimation.}, }
@article {pmid20819906, year = {2011}, author = {Leclercq, S and Giraud, I and Cordaux, R}, title = {Remarkable abundance and evolution of mobile group II introns in Wolbachia bacterial endosymbionts.}, journal = {Molecular biology and evolution}, volume = {28}, number = {1}, pages = {685-697}, doi = {10.1093/molbev/msq238}, pmid = {20819906}, issn = {1537-1719}, mesh = {Animals ; Base Sequence ; DNA Transposable Elements/*genetics ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Genome, Bacterial ; *Introns ; Molecular Sequence Data ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis/*genetics ; Wolbachia/classification/*genetics ; }, abstract = {The streamlined genomes of ancient obligate endosymbionts generally lack transposable elements, as a consequence of their intracellular confinement. Yet, the genomes of Wolbachia, one of the most abundant bacterial endosymbionts on Earth, are littered with transposable elements, in particular insertion sequences (ISs). This paradox raises the question of whether or not such a mobile DNA proliferation reflects a special feature of ISs. In this study, we focused on another class of transposable elements, group II introns, and conducted an in-depth analysis of their content and the microevolutionary processes responsible for their dynamics within Wolbachia genomes. We report an exceptionally high intron abundance and striking differences in copy numbers between Wolbachia strains as well as between intron families. Our bioinformatics and experimental results provide strong evidence that intron diversity is mainly caused by recent (and perhaps ongoing) mobility and horizontal transfers. Our data also support several temporally independent intron invasions during Wolbachia evolution. Furthermore, group II intron spread in some Wolbachia strains may be regulated through gene conversion-mediated inactivation of intron copies. Finally, we found introns to be involved in numerous genomic rearrangements. This underscores the high recombinogenic potential of group II introns, contrary to general expectations. Overall, our study represents the first comprehensive analysis of group II intron evolutionary dynamics in obligate intracellular bacteria. Our results show that bacterial endosymbionts with reduced genomes can sustain high loads of mobile group II introns, as hypothesized for the endosymbiont ancestor of mitochondria during early eukaryote evolution.}, }
@article {pmid20817243, year = {2010}, author = {Sacchi, L and Genchi, M and Clementi, E and Negri, I and Alma, A and Ohler, S and Sassera, D and Bourtzis, K and Bandi, C}, title = {Bacteriocyte-like cells harbour Wolbachia in the ovary of Drosophila melanogaster (Insecta, Diptera) and Zyginidia pullula (Insecta, Hemiptera).}, journal = {Tissue &amp; cell}, volume = {42}, number = {5}, pages = {328-333}, doi = {10.1016/j.tice.2010.07.009}, pmid = {20817243}, issn = {1532-3072}, mesh = {Animals ; Drosophila melanogaster/*microbiology ; Female ; Hemiptera/*microbiology ; Ovary/*cytology/microbiology ; Symbiosis ; Wolbachia ; }, abstract = {Wolbachia is the most widespread bacterial endosymbiont in insects. It is responsible for a variety of reproductive alterations of the hosts. Wolbachia is transmitted through the germline from mother to offspring and, in rare cases, between individuals. This implies that acquired properties (through symbiosis with Wolbachia) can become heritable. We investigated the transovarial inheritance of Wolbachia in two phylogenetically distant insects, Drosophila melanogaster and Zyginidia pullula. We detected in both systems bacteriocyte-like cells, densely packed with Wolbachia endosymbionts, at the tip of the ovarioles. Bacteriocytes are cells specialized to harbour bacteria, typical of mutualistic insect symbiosis. Our observations of bacteriocyte-like cells harbouring Wolbachia in the ovary emphasize the plasticity of the female reproductive system of insects, which maintains its function while some cells are densely colonized by bacteria. In summary, there is evidence from different insects that bacteria which behave as parasites of reproduction are harboured by cells resembling bacteriocytes, which appear to mediate transmission of the bacteria to the progeny. It seems a valid hypothesis that the bacteriocyte-like cells that we observed are not the result of a co-evolution of host and symbiont, considering that Wolbachia is not an obligatory symbiont in Drosophila and Zyginidia.}, }
@article {pmid20814704, year = {2010}, author = {Leborgne-Castel, N and Adam, T and Bouhidel, K}, title = {Endocytosis in plant-microbe interactions.}, journal = {Protoplasma}, volume = {247}, number = {3-4}, pages = {177-193}, pmid = {20814704}, issn = {1615-6102}, mesh = {*Endocytosis ; Host-Pathogen Interactions ; Membrane Microdomains/physiology ; Plant Diseases/immunology/microbiology/parasitology ; Plant Immunity ; Plant Physiological Phenomena ; Plants/immunology/*microbiology/*parasitology ; Rhizobium/physiology ; Symbiosis ; }, abstract = {Plants encounter throughout their life all kinds of microorganisms, such as bacteria, fungi, or oomycetes, with either friendly or unfriendly intentions. During evolution, plants have developed a wide range of defense mechanisms against attackers. In return, adapted microbes have developed strategies to overcome the plant lines of defense, some of these microbes engaging in mutualistic or parasitic endosymbioses. By sensing microbe presence and activating signaling cascades, the plasma membrane through its dynamics plays a crucial role in the ongoing molecular dialogue between plants and microbes. This review describes the contribution of endocytosis to different aspects of plant-microbe interactions, microbe recognition and development of a basal immune response, and colonization of plant cells by endosymbionts. The putative endocytic routes for the entry of microbe molecules or microbes themselves are explored with a special emphasis on clathrin-mediated endocytosis. Finally, we evaluate recent findings that suggest a link between the compartmentalization of plant plasma membrane into microdomains and endocytosis.}, }
@article {pmid20810215, year = {2010}, author = {Rossi, MI and Paiva, J and Bendas, A and Mendes-de-Almeida, F and Knackfuss, F and Miranda, M and Guerrero, J and Fernandes, O and Labarthe, N}, title = {Effects of doxycycline on the endosymbiont Wolbachia in Dirofilaria immitis (Leidy, 1856)--naturally infected dogs.}, journal = {Veterinary parasitology}, volume = {174}, number = {1-2}, pages = {119-123}, doi = {10.1016/j.vetpar.2010.07.019}, pmid = {20810215}, issn = {1873-2550}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Antigens, Bacterial/blood ; DNA, Bacterial/blood ; Dirofilaria immitis/drug effects/*microbiology ; Dog Diseases/*microbiology/*parasitology ; Dogs ; Doxycycline/*pharmacology ; Time Factors ; Wolbachia/*drug effects ; }, abstract = {Dirofilaria immitis carries intracellular endosymbiotic bacteria of the genus Wolbachia, known to be vital for the worms and sensitive to tetracycline antibiotics. With the purpose of studying the interaction between D. immitis and the endosymbiont Wolbachia sp., heartworm naturally infected microfilaremic or antigenemic dogs were treated with doxycycline (10mg/kg/day of the drug in three cycles of 21 days each, with 6-month intervals). Blood samples were collected on days 0, 7 and 21 of each treatment as well as on day 111 after the beginning of each cycle. A final sample was collected on day 723 from the beginning of the first treatment. The samples were examined for the presence and number of microfilariae and the presence of antigen as well as the presences of D. immitis and Wolbachia sp. DNA using PCR (polymerase chain reaction). With this approach, an evaluation of the effect of doxycycline on antigenemia and on the presence of Wolbachia sp. DNA in dogs with heartworm infection was possible. Doxycycline treatment did not alter the detection of adult parasite antigens with the exception of two animals, though the number of animals carrying Wolbachia sp. DNA decreased, despite the presence of the microfilariae. The effect of the antibiotic therapy on the worms may have interfered with the transmission of heartworm disease because the population of microfilariae and the number of microfilaremic dogs were reduced and the microfilariae positive samples that were found did not test positive for Wolbachia sp. in many cases. These findings suggest that in areas were doxycycline is extensively used D. immitis transmission may be impaired by the reduction on the number of microfilariae and on the endosymbiotic bacteria in the larvae turning them incapable of completing development once they infected a new host.}, }
@article {pmid20807539, year = {2010}, author = {Gavotte, L and Mercer, DR and Stoeckle, JJ and Dobson, SL}, title = {Costs and benefits of Wolbachia infection in immature Aedes albopictus depend upon sex and competition level.}, journal = {Journal of invertebrate pathology}, volume = {105}, number = {3}, pages = {341-346}, pmid = {20807539}, issn = {1096-0805}, support = {R01 AI051533/AI/NIAID NIH HHS/United States ; R01-AI067434/AI/NIAID NIH HHS/United States ; R01 AI067434-01A1/AI/NIAID NIH HHS/United States ; R01-AI051533/AI/NIAID NIH HHS/United States ; R01 AI051533-01A1/AI/NIAID NIH HHS/United States ; R01 AI067434/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*microbiology ; Animals ; Bacterial Infections/*physiopathology ; Female ; Male ; Pest Control, Biological/*methods ; Polymerase Chain Reaction ; Sex Ratio ; *Wolbachia ; }, abstract = {Bacterial endosymbionts induce various effects on hosts and can dramatically impact host fitness and development. An example is provided by obligate, maternally-inherited Wolbachia, which infect a broad range of invertebrates. Wolbachia are capable of altering host reproduction, thereby promoting infection spread. Wolbachia also pose direct physiological costs and benefits to hosts, complicating their categorization as parasites or mutualists. This study examines for an effect of Wolbachia infection in intra-specific larval competition by Aedes albopictus mosquitoes, with the goal of examining for an impact of Wolbachia infection in mixed populations. Similar to prior work examining for an influence of Wolbachia infection on the fitness of A. albopictus in adults, the results presented here support the hypothesized impact of Wolbachia across all life stages, including immatures. The differential competitiveness of infected larvae detected in our experiments indicates that Wolbachia infected A. albopictus females are less competitive relative to uninfected females when competing under highly competitive conditions. In contrast, under low competitive pressures, infected females experience higher survivorship. Thus, Wolbachia infection shifts from parasitism to mutualism as a function of developmental conditions. Results are discussed in relation to the invasion and persistence of Wolbachia in A. albopictus populations. The results are important to the evolution of stable Wolbachia symbioses, including Wolbachia invasion of an uninfected population. The resulting infection dynamics that occur in an infected population are discussed.}, }
@article {pmid20804456, year = {2010}, author = {Feddermann, N and Muni, RR and Zeier, T and Stuurman, J and Ercolin, F and Schorderet, M and Reinhardt, D}, title = {The PAM1 gene of petunia, required for intracellular accommodation and morphogenesis of arbuscular mycorrhizal fungi, encodes a homologue of VAPYRIN.}, journal = {The Plant journal : for cell and molecular biology}, volume = {64}, number = {3}, pages = {470-481}, doi = {10.1111/j.1365-313X.2010.04341.x}, pmid = {20804456}, issn = {1365-313X}, mesh = {Cloning, Molecular ; DNA, Plant/genetics ; Gene Expression Regulation, Plant ; Genes, Plant ; Membrane Proteins ; Molecular Sequence Data ; Mutation ; Mycorrhizae/*physiology ; Petunia/*genetics/*microbiology ; Phosphate Transport Proteins/genetics/*metabolism ; Plant Proteins/genetics/*metabolism ; Plant Roots/microbiology ; Protein Structure, Secondary ; Saccharomyces cerevisiae Proteins ; Symbiosis ; }, abstract = {Most terrestrial plants engage into arbuscular mycorrhizal (AM) symbiosis with fungi of the phylum Glomeromycota. The initial recognition of the fungal symbiont results in the activation of a symbiosis signalling pathway that is shared with the root nodule symbiosis (common SYM pathway). The subsequent intracellular accommodation of the fungus, and the elaboration of its characteristic feeding structures, the arbuscules, depends on a genetic programme in the plant that has recently been shown to involve the VAPYRIN gene in Medicaco truncatula. We have previously identified a mutant in Petunia hybrida, penetration and arbuscule morphogenesis 1 (pam1), that is defective in the intracellular stages of AM development. Here, we report on the cloning of PAM1, which encodes a VAPYRIN homologue. PAM1 protein localizes to the cytosol and the nucleus, with a prominent affinity to mobile spherical structures that are associated with the tonoplast, and are therefore referred to as tonospheres. In mycorrhizal roots, tonospheres were observed in the vicinity of intracellular hyphae, where they may play an essential role in the accommodation and morphogenesis of the fungal endosymbiont.}, }
@article {pmid20739055, year = {2010}, author = {Taylor, MJ and Hoerauf, A and Bockarie, M}, title = {Lymphatic filariasis and onchocerciasis.}, journal = {Lancet (London, England)}, volume = {376}, number = {9747}, pages = {1175-1185}, doi = {10.1016/S0140-6736(10)60586-7}, pmid = {20739055}, issn = {1474-547X}, mesh = {Africa South of the Sahara ; Age Factors ; Albendazole/therapeutic use ; Animals ; Anti-Bacterial Agents/*therapeutic use ; Antinematodal Agents/*therapeutic use ; Blindness/parasitology ; Culicidae ; Dermatitis/parasitology ; Dermatologic Agents/therapeutic use ; Diethylcarbamazine/therapeutic use ; Doxycycline/*therapeutic use ; Drug Therapy, Combination ; *Elephantiasis, Filarial/complications/diagnosis/drug therapy/epidemiology/physiopathology/transmission ; Filaricides/therapeutic use ; Gram-Negative Bacterial Infections/complications ; Granuloma/parasitology ; Humans ; India ; Ivermectin/therapeutic use ; Lymphadenitis/parasitology ; Lymphangitis/parasitology ; Lymphedema/parasitology ; Macrolides/therapeutic use ; *Onchocerciasis/complications/diagnosis/drug therapy/epidemiology/physiopathology/transmission ; Prevalence ; Symbiosis ; Wolbachia/drug effects ; }, abstract = {Lymphatic filariasis and onchocerciasis are parasitic helminth diseases that constitute a serious public health issue in tropical regions. The filarial nematodes that cause these diseases are transmitted by blood-feeding insects and produce chronic and long-term infection through suppression of host immunity. Disease pathogenesis is linked to host inflammation invoked by the death of the parasite, causing hydrocoele, lymphoedema, and elephantiasis in lymphatic filariasis, and skin disease and blindness in onchocerciasis. Most filarial species that infect people co-exist in mutualistic symbiosis with Wolbachia bacteria, which are essential for growth, development, and survival of their nematode hosts. These endosymbionts contribute to inflammatory disease pathogenesis and are a target for doxycycline therapy, which delivers macrofilaricidal activity, improves pathological outcomes, and is effective as monotherapy. Drugs to treat filariasis include diethylcarbamazine, ivermectin, and albendazole, which are used mostly in combination to reduce microfilariae in blood (lymphatic filariasis) and skin (onchocerciasis). Global programmes for control and elimination have been developed to provide sustained delivery of drugs to affected communities to interrupt transmission of disease and ultimately eliminate this burden on public health.}, }
@article {pmid20736348, year = {2010}, author = {Saffo, MB and McCoy, AM and Rieken, C and Slamovits, CH}, title = {Nephromyces, a beneficial apicomplexan symbiont in marine animals.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {107}, number = {37}, pages = {16190-16195}, pmid = {20736348}, issn = {1091-6490}, support = {5G 13LM-009396-02/LM/NLM NIH HHS/United States ; }, mesh = {Animals ; Apicomplexa/*physiology/ultrastructure ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; Toxoplasma/physiology ; Urochordata/*physiology/ultrastructure ; }, abstract = {With malaria parasites (Plasmodium spp.), Toxoplasma, and many other species of medical and veterinary importance its iconic representatives, the protistan phylum Apicomplexa has long been defined as a group composed entirely of parasites and pathogens. We present here a report of a beneficial apicomplexan: the mutualistic marine endosymbiont Nephromyces. For more than a century, the peculiar structural and developmental features of Nephromyces, and its unusual habitat, have thwarted characterization of the phylogenetic affinities of this eukaryotic microbe. Using short-subunit ribosomal DNA (SSU rDNA) sequences as key evidence, with sequence identity confirmed by fluorescence in situ hybridization (FISH), we show that Nephromyces, originally classified as a chytrid fungus, is actually an apicomplexan. Inferences from rDNA data are further supported by the several apicomplexan-like structural features in Nephromyces, including especially the strong resemblance of Nephromyces infective stages to apicomplexan sporozoites. The striking emergence of the mutualistic Nephromyces from a quintessentially parasitic clade accentuates the promise of this organism, and the three-partner symbiosis of which it is a part, as a model for probing the factors underlying the evolution of mutualism, pathogenicity, and infectious disease.}, }
@article {pmid20732433, year = {2010}, author = {Peat, SM and Ffrench-Constant, RH and Waterfield, NR and Marokházi, J and Fodor, A and Adams, BJ}, title = {A robust phylogenetic framework for the bacterial genus Photorhabdus and its use in studying the evolution and maintenance of bioluminescence: a case for 16S, gyrB, and glnA.}, journal = {Molecular phylogenetics and evolution}, volume = {57}, number = {2}, pages = {728-740}, doi = {10.1016/j.ympev.2010.08.012}, pmid = {20732433}, issn = {1095-9513}, mesh = {DNA Gyrase/*genetics ; Evolution, Molecular ; Gene Transfer, Horizontal/genetics ; Glutamate-Ammonia Ligase/*genetics ; Photorhabdus/*classification/*genetics/metabolism ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; }, abstract = {Photorhabdus spp., the only known bioluminescent terrestrial bacteria are well known for their symbiotic association with heterorhabditid nematodes. This association, along with their ability to kill insects, has aroused interest in the evolutionary relationships within this bacterial group. Currently, three species are recognized within the genus Photorhabdus; P. temperata and P. luminescens, which are endosymbionts of Heterorhabditis spp., and P. asymbiotica, which has been isolated from human wounds and has recently been shown to also have a heterorhabditid nematode vector. To examine phylogenetic relationships among these taxa, we utilize total evidence Bayesian, likelihood, and parsimony based analyses of three genetic loci (16S rRNA gene, gyrB, and glnA) to construct a robust evolutionary hypothesis for the genus Photorhabdus. Here we use this phylogeny to evaluate existing specific and sub-specific taxonomic statements within the genus, identify previously undescribed Photorhabdus strains, test the utility of 16S rRNA gene, gyrB, and glnA in resolving various levels of relationships within the genus, and, finally, to investigate the evolution of bioluminescence. The genes examined produced the most robust phylogenetic hypothesis to date for the genus Photorhabdus, as indicated by strong bootstrap and posterior probability values at previously unresolved or poorly resolved nodes. We show that glnA is particularly useful in resolving specific and intra-specific relationships poorly resolved in other studies. We conclude that P. asymbiotica is the sister group to P. luminescens and that the new strains HIT and JUN should be given a new group designation within P. asymbiotica. Furthermore, we reveal a pattern of decline in bioluminescent intensity through the evolution of Photorhabdus, suggesting that this may be a trait acquired and maintained under previous ecological (aquatic) selection pressures that is now gradually being lost in its terrestrial environment.}, }
@article {pmid20730111, year = {2010}, author = {Slatko, BE and Taylor, MJ and Foster, JM}, title = {The Wolbachia endosymbiont as an anti-filarial nematode target.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {51}, number = {1}, pages = {55-65}, pmid = {20730111}, issn = {0334-5114}, abstract = {Human disease caused by parasitic filarial nematodes is a major cause of global morbidity. The parasites are transmitted by arthropod intermediate hosts and are responsible for lymphatic filariasis (elephantiasis) or onchocerciasis (river blindness). Within these filarial parasites are intracellular alpha-proteobacteria, Wolbachia, that were first observed almost 30 years ago. The obligate endosymbiont has been recognized as a target for anti-filarial nematode chemotherapy as evidenced by the loss of worm fertility and viability upon antibiotic treatment in an extensive series of human trials. While current treatments with doxycycline and rifampicin are not practical for widespread use due to the length of required treatments and contraindications, anti-Wolbachia targeting nevertheless appears a promising alternative for filariasis control in situations where current programmatic strategies fail or are unable to be delivered and it provides a superior efficacy for individual therapy. The mechanisms that underlie the symbiotic relationship between Wolbachia and its nematode hosts remain elusive. Comparative genomics, bioinfomatic and experimental analyses have identified a number of potential interactions, which may be drug targets. One candidate is de novo heme biosynthesis, due to its absence in the genome sequence of the host nematode, Brugia malayi, but presence in Wolbachia and its potential roles in worm biology. We describe this and several additional candidate targets, as well as our approaches for understanding the nature of the host-symbiont relationship.}, }
@article {pmid20730104, year = {2010}, author = {Xie, J and Vilchez, I and Mateos, M}, title = {Spiroplasma bacteria enhance survival of Drosophila hydei attacked by the parasitic wasp Leptopilina heterotoma.}, journal = {PloS one}, volume = {5}, number = {8}, pages = {e12149}, pmid = {20730104}, issn = {1932-6203}, support = {R03 AI078348/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Drosophila/*microbiology/*parasitology/physiology ; Humans ; Larva/microbiology/parasitology/physiology ; Male ; Oviposition ; Spiroplasma/*physiology ; Survival Analysis ; Wasps/*physiology ; }, abstract = {BACKGROUND: Maternally-transmitted associations between endosymbiotic bacteria and insects are ubiquitous. While many of these associations are obligate and mutually beneficial, many are facultative, and the mechanism(s) by which these microbes persist in their host lineages remain elusive. Inherited microbes with imperfect transmission are expected to be lost from their host lineages if no other mechanisms increase their persistence (i.e., host reproductive manipulation and/or fitness benefits to host). Indeed numerous facultative heritable endosymbionts are reproductive manipulators. Nevertheless, many do not manipulate reproduction, so they are expected to confer fitness benefits to their hosts, as has been shown in several studies that report defense against natural enemies, tolerance to environmental stress, and increased fecundity.<br><br>We examined whether larval to adult survival of Drosophila hydei against attack by a common parasitoid wasp (Leptopilina heterotoma), differed between uninfected flies and flies that were artificially infected with Spiroplasma, a heritable endosymbiont of Drosophila hydei that does not appear to manipulate host reproduction. Survival was significantly greater for Spiroplasma-infected flies, and the effect of Spiroplasma infection was most evident during the host's pupal stage. We examined whether or not increased survival of Spiroplasma-infected flies was due to reduced oviposition by the wasp (i.e., pre-oviposition mechanism). The number of wasp eggs per fly larva did not differ significantly between Spiroplasma-free and Spiroplasma-infected fly larvae, suggesting that differential fly survival is due to a post-oviposition mechanism.<br><br>CONCLUSIONS/SIGNIFICANCE: Our results suggest that Spiroplasma confers protection to D. hydei against wasp parasitism. This is to our knowledge the first report of a potential defensive mutualism in the genus Spiroplasma. Whether it explains the persistence and high abundance of this strain in natural populations of D. hydei, as well as the widespread distribution of heritable Spiroplasma in Drosophila and other arthropods, remains to be investigated.}, }
@article {pmid20723069, year = {2010}, author = {Gueguen, G and Vavre, F and Gnankine, O and Peterschmitt, M and Charif, D and Chiel, E and Gottlieb, Y and Ghanim, M and Zchori-Fein, E and Fleury, F}, title = {Endosymbiont metacommunities, mtDNA diversity and the evolution of the Bemisia tabaci (Hemiptera: Aleyrodidae) species complex.}, journal = {Molecular ecology}, volume = {19}, number = {19}, pages = {4365-4376}, doi = {10.1111/j.1365-294X.2010.04775.x}, pmid = {20723069}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification/genetics ; *Biological Evolution ; DNA, Mitochondrial/genetics ; DNA, Ribosomal Spacer/genetics ; Hemiptera/*genetics/*microbiology ; Linkage Disequilibrium ; Molecular Sequence Data ; *Phylogeny ; *Symbiosis ; }, abstract = {Bemisia tabaci, an invasive pest that causes crop damage worldwide, is a highly differentiated species complex, divided into biotypes that have mainly been defined based on mitochondrial DNA sequences. Although endosymbionts can potentially induce population differentiation, specialization and indirect selection on mtDNA, studies have largely ignored these influential passengers in B. tabaci, despite as many as seven bacterial endosymbionts have been identified. Here, we investigate the composition of the whole bacterial community in worldwide populations of B. tabaci, together with host genetic differentiation, focusing on the invasive B and Q biotypes. Among 653 individuals studied, more than 95% of them harbour at least one secondary endosymbiont, and multiple infections are very common. In addition, sequence analyses reveal a very high diversity of facultative endosymbionts in B. tabaci, with some bacterial genus being represented by more than one strain. In the B and Q biotypes, nine different strains of bacteria have been identified. The mtDNA-based phylogeny of B. tabaci also reveals a very high nucleotide diversity that partitions the two ITS clades (B and Q) into six CO1 genetic groups. Each genetic group is in linkage disequilibrium with a specific combination of endosymbionts. All together, our results demonstrate the rapid dynamics of the bacterial endosymbiont-host associations at a small evolutionary scale, questioning the role of endosymbiotic communities in the evolution of the Bemisia tabaci species complex and strengthening the need to develop a metacommunity theory of inherited endosymbionts.}, }
@article {pmid20716370, year = {2010}, author = {Barribeau, SM and Sok, D and Gerardo, NM}, title = {Aphid reproductive investment in response to mortality risks.}, journal = {BMC evolutionary biology}, volume = {10}, number = {}, pages = {251}, pmid = {20716370}, issn = {1471-2148}, mesh = {Animals ; Aphids/drug effects/*microbiology/*physiology ; Pheromones/pharmacology ; Reproduction/drug effects ; Sesquiterpenes/pharmacology ; Symbiosis/*physiology ; }, abstract = {BACKGROUND: Aphids are striking in their prodigious reproductive capacity and reliance on microbial endosymbionts, which provision their hosts with necessary amino acids and provide protection against parasites and heat stress. Perhaps as a result of this bacterial dependence, aphids have limited immune function that may leave them vulnerable to bacterial pathogens. An alternative, non-immunological response that may be available to infected aphids is to increase reproduction, thereby ameliorating fitness loss from infection. Such a response would reduce the need to mount a potentially energetically costly immune response, and would parallel that of other hosts that alter life-history traits when there is a risk of infection. Here we examined whether pea aphids (Acyrthosiphon pisum) respond to immunological challenges by increasing reproduction. As a comparison to the response to the internal cue of risk elicited by immunological challenge, we also exposed pea aphids to an external cue of risk--the aphid alarm pheromone (E)-β-farnesene (EBF), which is released in the presence of predators. For each challenge, we also examined whether the presence of symbionts modified the host response, as maintaining host fitness in the face of challenge would benefit both the host and its dependent bacteria.<br><br>RESULTS: We found that aphids stabbed abdominally with a sterile needle had reduced fecundity relative to control aphids but that aphids stabbed with a needle bearing heat-killed bacteria had reproduction intermediate, and statistically indistinguishable, to the aphids stabbed with a sterile needle and the controls. Aphids with different species of facultative symbiotic bacteria had different reproductive patterns overall, but symbionts in general did not alter aphid reproduction in response to bacterial exposure. However, in response to exposure to alarm pheromone, aphids with Hamiltonella defensa or Serratia symbiotica symbiotic infections increased reproduction but those without a facultative symbiont or with Regiella insecticola did not.<br><br>CONCLUSIONS: Overall, our results suggest that pea aphids are able to increase their reproduction in response to specific cues and that symbiont presence sometimes moderates this response. Such increased reproduction in response to risk of death increases the fitness of both aphids and their vertically transmitted symbionts, and since these organisms have high reproductive capacity, slight increases in reproduction could lead to a very large numerical advantage later in the season. Thus both symbiotic partners can benefit by increasing host fecundity under dangerous conditions.}, }
@article {pmid20700735, year = {2010}, author = {Tanifuji, G and Archibald, JM}, title = {Actin gene family dynamics in cryptomonads and red algae.}, journal = {Journal of molecular evolution}, volume = {71}, number = {3}, pages = {169-179}, pmid = {20700735}, issn = {1432-1432}, mesh = {Actins/*genetics ; Cryptophyta/*genetics ; Evolution, Molecular ; Introns/genetics ; Phylogeny ; Plant Proteins/genetics ; Rhodophyta/*genetics ; Sequence Alignment ; Symbiosis ; }, abstract = {Here we present evidence for a complex evolutionary history of actin genes in red algae and cryptomonads, a group that acquired photosynthesis secondarily through the engulfment of a red algal endosymbiont. Four actin genes were found in the nuclear genome of the cryptomonad, Guillardia theta, and in the genome of the red alga, Galdieria sulphuraria, a member of the Cyanidiophytina. Phylogenetic analyses reveal that the both organisms possess two distinct sequence types, designated "type-1" and "type-2." A weak but consistent phylogenetic affinity between the cryptomonad type-2 sequences and the type-2 sequences of G. sulphuraria and red algae belonging to the Rhodophytina was observed. This is consistent with the possibility that the cryptomonad type-2 sequences are derived from the red algal endosymbiont that gave rise to the cryptomonad nucleomorph and plastid. Red algae as a whole possess two very different actin sequence types, with G. sulphuraria being the only organism thus far known to possess both. The common ancestor of Rhodophytina and Cyanidiophytina may have had two actin genes, with differential loss explaining the distribution of these genes in modern-day groups. Our study provides new insight into the evolution and divergence of actin genes in cryptomonads and red algae, and in doing so underscores the challenges associated with heterogeneity in actin sequence evolution and ortholog/paralog detection.}, }
@article {pmid20700535, year = {2010}, author = {Glaser, RL and Meola, MA}, title = {The native Wolbachia endosymbionts of Drosophila melanogaster and Culex quinquefasciatus increase host resistance to West Nile virus infection.}, journal = {PloS one}, volume = {5}, number = {8}, pages = {e11977}, pmid = {20700535}, issn = {1932-6203}, support = {R21 AI076258/AI/NIAID NIH HHS/United States ; AI076258/AI/NIAID NIH HHS/United States ; }, mesh = {Animal Feed/virology ; Animals ; Chikungunya virus/physiology ; Culex/*microbiology/physiology ; Drosophila melanogaster/*microbiology/physiology ; Female ; *Immunity, Innate ; Insect Vectors/microbiology/physiology ; La Crosse virus/physiology ; Male ; Phenotype ; *Symbiosis ; West Nile Fever/*immunology/microbiology/transmission ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: The bacterial endosymbiont Wolbachia pipientis has been shown to increase host resistance to viral infection in native Drosophila hosts and in the normally Wolbachia-free heterologous host Aedes aegypti when infected by Wolbachia from Drosophila melanogaster or Aedes albopictus. Wolbachia infection has not yet been demonstrated to increase viral resistance in a native Wolbachia-mosquito host system.<br><br>In this study, we investigated Wolbachia-induced resistance to West Nile virus (WNV; Flaviviridae) by measuring infection susceptibility in Wolbachia-infected and Wolbachia-free D. melanogaster and Culex quinquefasciatus, a natural mosquito vector of WNV. Wolbachia infection of D. melanogaster induces strong resistance to WNV infection. Wolbachia-infected flies had a 500-fold higher ID50 for WNV and produced 100,000-fold lower virus titers compared to flies lacking Wolbachia. The resistance phenotype was transmitted as a maternal, cytoplasmic factor and was fully reverted in flies cured of Wolbachia. Wolbachia infection had much less effect on the susceptibility of D. melanogaster to Chikungunya (Togaviridae) and La Crosse (Bunyaviridae) viruses. Wolbachia also induces resistance to WNV infection in Cx. quinquefasciatus. While Wolbachia had no effect on the overall rate of peroral infection by WNV, Wolbachia-infected mosquitoes produced lower virus titers and had 2 to 3-fold lower rates of virus transmission compared to mosquitoes lacking Wolbachia.<br><br>CONCLUSIONS/SIGNIFICANCE: This is the first demonstration that Wolbachia can increase resistance to arbovirus infection resulting in decreased virus transmission in a native Wolbachia-mosquito system. The results suggest that Wolbachia reduces vector competence in Cx. quinquefasciatus, and potentially in other Wolbachia-infected mosquito vectors.}, }
@article {pmid20695281, year = {2010}, author = {Ball, TS and Ritchie, SR}, title = {Sampling biases of the BG-sentinel trap with respect to physiology, age, and body size of adult Aedes aegypti (Diptera: Culicidae).}, journal = {Journal of medical entomology}, volume = {47}, number = {4}, pages = {649-656}, doi = {10.1603/me09218}, pmid = {20695281}, issn = {0022-2585}, mesh = {Aging/*physiology ; Animals ; Body Size/*physiology ; Culicidae/*physiology ; Entomology/*instrumentation ; Female ; Male ; Population Surveillance ; Selection Bias ; }, abstract = {Currently, Aedes aegypti (L.) control strategies are being developed that involve manipulation of the vector at the adult stage (e.g., the use of the bacterial endosymbiont Wolbachia to shorten the life span of the vector population). These novel strategies demand adult sampling methods to measure changes in population size, structure (age, sex ratio), and, ultimately, the success of the program. Each sampling method presents certain biases. Once these biases are defined, methods used to estimate population size and structure can be calibrated accordingly, resulting in more accurate and complex estimates of the vector population. A series of mark-release-recapture experiments with adult Ae. aegypti were conducted in a large outdoor flight cage and an indoor setting in far north Queensland, Australia. The biases of the BG-Sentinel trap (BGS) were investigated across several categories, as follows: 1) mosquito age; 2) sex; 3) physiological status; and 4) body size. Biases were not detected across age groups or body sizes. A significant bias was detected across physiological groups: nulliparous females were recaptured at a significantly lower rate than all other groups except blood-fed parous females, which were also recaptured at a low rate by the BGS. Males were recaptured at a higher rate than all groups, but only a significant difference in recapture rates was observed between males and nulliparous females. Previous studies show that the BGS is a highly effective tool for Ae. aegypti surveillance. The BGS proves to be a reliable tool in Ae. aegypti surveillance with consistent sampling outcomes. The sampling bias of the BGS is measurable and can be used to generate more accurate estimates of the adult population and its attributes.}, }
@article {pmid20695271, year = {2010}, author = {Leo, SS and Pybus, MJ and Sperling, FA}, title = {Deep mitochondrial DNA lineage divergences within Alberta populations of Dermacentor albipictus (Acari: Ixodidae) do not indicate distinct species.}, journal = {Journal of medical entomology}, volume = {47}, number = {4}, pages = {565-574}, pmid = {20695271}, issn = {0022-2585}, mesh = {Alberta ; Animals ; DNA/genetics ; DNA, Mitochondrial/*genetics ; Demography ; Dermacentor/*genetics ; Genetic Speciation ; *Genetic Variation ; Phylogeny ; }, abstract = {The winter tick Dermacentor albipictus (Packard) has a single-host life cycle that allows it to reach severe infestation levels on ungulates, particularly moose. Genotypic variation within these and related ticks has been a source of taxonomic confusion, although the continuity in their morphology and life history has generally been interpreted as indicating the existence of a single species. To further investigate this variation, we sequenced regions of two mitochondrial DNA (mtDNA) genes (COI and 16S rDNA),two nuclear genes (lysozyme and ITS-2), and two bacterial markers from Francisella-like endosymbionts found in these ticks (eubacterial mtDNA 16S rRNA and a homolog of Francisella tularensis [Dorofe'ev] 17-kDa lipoprotein). We sampled 42 D. albipictus individuals from whitetail and mule deer culled from three populations in east-central Alberta, as well as four D. albipictus and two Dermacentor variabilis (Say) from other locations. We then compared DNA sequence variation between the genes and related this to variation in the morphology of spiracle plates. Both mtDNA regions indicated two deeply diverged lineages (mean difference of 7.1% for COI and 4.5% for 16S) that would normally be considered diagnostic of distinct species in DNA barcoding studies. However, very little divergence was revealed by nuclear gene sequences, bacterial endosymbionts, and morphometric analyses, and any variation that did occur in these markers was not congruent with mtDNA divergences. We conclude that the sampled populations in Alberta represent a single species, D. albipictus, and reiterate the importance of integrative approaches in species delimitation.}, }
@article {pmid20687906, year = {2010}, author = {King, KC and Hurst, GD}, title = {Losing the desire: selection can promote obligate asexuality.}, journal = {BMC biology}, volume = {8}, number = {}, pages = {101}, pmid = {20687906}, issn = {1741-7007}, mesh = {Animals ; Biological Evolution ; Models, Biological ; *Parthenogenesis ; Selection, Genetic ; Wasps/genetics/*physiology ; }, abstract = {Whilst parthenogenesis has evolved multiple times from sexual invertebrate and vertebrate lineages, the drivers and consequences of the sex-asex transition remain mostly uncertain. A model by Stouthamer et al. recently published in BMC Evolutionary Biology shows a pathway by which obligate asexuality could be selected for following endosymbiont infection. See research article http://www.biomedcentral.com/1471-2148/10/229.}, }
@article {pmid20686788, year = {2011}, author = {Uchitel, A and Omacini, M and Chaneton, EJ}, title = {Inherited fungal symbionts enhance establishment of an invasive annual grass across successional habitats.}, journal = {Oecologia}, volume = {165}, number = {2}, pages = {465-475}, pmid = {20686788}, issn = {1432-1939}, mesh = {*Ecosystem ; Fungi/classification/*physiology ; Lolium/growth &amp; development/microbiology/physiology ; Neotyphodium/physiology ; Poaceae/growth &amp; development/*microbiology/physiology ; Population Density ; Seeds/growth &amp; development/physiology ; *Symbiosis ; Time Factors ; }, abstract = {Plants infected with vertically transmitted fungal endophytes carry their microbial symbionts with them during dispersal into new areas. Yet, whether seed-borne endophytes enhance the host plant's ability to overcome colonisation barriers and to regenerate within invaded sites remains poorly understood. We examined how symbiosis with asexual endophytic fungi (Neotyphodium) affected establishment and seed loss to predators in the invasive annual grass Lolium multiflorum (Italian ryegrass) across contrasting successional plots. Italian ryegrass seeds with high and low endophyte incidence were sown into three communities: a 1-year-old fallow field, a 15-year-old grassland, and a 24-year-old forest, which conformed to an old-field chronosequence in the eastern Inland Pampa, Argentina. We found that endophyte infection consistently increased host population recruitment and reproductive output. Endophyte presence also enhanced aerial biomass production of ryegrass in a low recruitment year but not in a high recruitment year, suggesting that symbiotic effects on growth performance are density dependent. Endophyte presence reduced seed removal by rodents, although differential predation may not account for the increased success of infected grass populations. Overall, there was no statistical evidence for an endophyte-by-site interaction, indicating that the fungal endosymbiont benefitted host establishment regardless of large differences in biotic and abiotic environment among communities. Our results imply that hereditary endophytes may increase the chances for host grass species to pass various ecological filters associated with invasion resistance across a broad range of successional habitats.}, }
@article {pmid20682282, year = {2011}, author = {Schwenkert, S and Soll, J and Bölter, B}, title = {Protein import into chloroplasts--how chaperones feature into the game.}, journal = {Biochimica et biophysica acta}, volume = {1808}, number = {3}, pages = {901-911}, doi = {10.1016/j.bbamem.2010.07.021}, pmid = {20682282}, issn = {0006-3002}, mesh = {Cell Nucleus/*metabolism ; Chloroplasts/*metabolism ; Molecular Chaperones/*metabolism ; Plant Proteins/*metabolism ; Protein Transport ; }, abstract = {Chloroplasts originated from an endosymbiotic event, in which an ancestral photosynthetic cyanobacterium was engulfed by a mitochondriate eukaryotic host cell. During evolution, the endosymbiont lost its autonomy by means of a massive transfer of genetic information from the prokaryotic genome to the host nucleus. Consequently, the development of protein import machineries became necessary for the relocation of proteins that are now nuclear-encoded and synthesized in the cytosol but destined for the chloroplast. Organelle biogenesis and maintenance requires a tight coordination of transcription, translation and protein import between the host cell and the organelle. This review focuses on the translocation complexes in the outer and inner envelope membrane with a special emphasis on the role of molecular chaperones. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.}, }
@article {pmid20679093, year = {2011}, author = {Davis, JJ and Olsen, GJ}, title = {Characterizing the native codon usages of a genome: an axis projection approach.}, journal = {Molecular biology and evolution}, volume = {28}, number = {1}, pages = {211-221}, pmid = {20679093}, issn = {1537-1719}, mesh = {Algorithms ; Bacillus anthracis/genetics ; Base Composition/genetics ; *Codon ; Escherichia coli/genetics ; Gene Expression Regulation, Bacterial ; Gene Transfer, Horizontal ; Genes, Archaeal ; *Genes, Bacterial ; *Genome, Bacterial ; Pseudomonas aeruginosa/genetics ; }, abstract = {Codon usage can provide insights into the nature of the genes in a genome. Genes that are "native" to a genome (have not been recently acquired by horizontal transfer) range in codon usage from a low-bias "typical" usage to a more biased "high-expression" usage characteristic of genes encoding abundant proteins. Genes that differ from these native codon usages are candidates for foreign genes that have been recently acquired by horizontal gene transfer. In this study, we present a method for characterizing the codon usages of native genes--both typical and highly expressed--within a genome. Each gene is evaluated relative to a half line (or axis) in a 59D space of codon usage. The axis begins at the modal codon usage, the usage that matches the largest number of genes in the genome, and it passes through a point representing the codon usage of a set of genes with expression-related bias. A gene whose codon usage matches (does not significantly differ from) a point on this axis is a candidate native gene, and the location of its projection onto the axis provides a general estimate of its expression level. A gene that differs significantly from all points on the axis is a candidate foreign gene. This automated approach offers significant improvements over existing methods. We illustrate this by analyzing the genomes of Pseudomonas aeruginosa PAO1 and Bacillus anthracis A0248, which can be difficult to analyze with commonly used methods due to their biased base compositions. Finally, we use this approach to measure the proportion of candidate foreign genes in 923 bacterial and archaeal genomes. The organisms with the most homogeneous genomes (containing the fewest candidate foreign genes) are mostly endosymbionts and parasites, though with exceptions that include Pelagibacter ubique and Beutenbergia cavernae. The organisms with the most heterogeneous genomes (containing the most candidate foreign genes) include members of the genera Bacteroides, Corynebacterium, Desulfotalea, Neisseria, Xylella, and Thermobaculum.}, }
@article {pmid20678295, year = {2011}, author = {Zapalski, MK and Hubert, BL}, title = {First fossil record of parasitism in Devonian calcareous sponges (stromatoporoids).}, journal = {Parasitology}, volume = {138}, number = {1}, pages = {132-138}, doi = {10.1017/S0031182010001071}, pmid = {20678295}, issn = {1469-8161}, mesh = {Animals ; Aquatic Organisms/physiology ; Food Chain ; *Fossils ; France ; Host-Parasite Interactions ; Invertebrates/*physiology ; Porifera/growth &amp; development/*parasitology ; }, abstract = {INTRODUCTION: Palaeozoic calcareous sponges (stromatoporoids) are common bio-constructing fossils; they are sometimes found in association with helicoidal structures of unknown biological affinities. The interaction between the tube-forming organisms has usually been classified as commensalism.<br><br>METHODS: About 260 stromatoporoid skeletons from the Middle Devonian (Givetian) of the Mont d'Haurs section near Givet (Champagne-Ardenne, France) were thin-sectioned and analysed under transmitted light.<br><br>RESULTS: Approximately 10% of the examined stromatoporoids (mainly belonging to the genera Actinostroma, Stromatopora and Stromatoporella) contain tubes classified as Torquaysalpinx sp. The Torquaysalpinx organisms penetrated the skeletons of stromatoporoids in vivo (as evidenced by skeletal overgrowths); around the infesting organisms, growth bands are bent down.<br><br>CONCLUSION: Diminished growth rates around the infesting organism demonstrate a negative influence on the host, similar to that seen in the modern demosponge-polychaete association of Verongia-Haplosyllis. This is demonstrated by changes in growth bands. As in the above-mentioned association, the endosymbiont might have been feeding directly upon the tissues of the host. The Torquaysalpinx organisms were gaining habitat and possibly also food resources - for them this interaction was clearly positive. This long-term association can therefore be classified as parasitism. This is the first evidence for parasitism in Palaeozoic sponges.}, }
@article {pmid20676599, year = {2010}, author = {Sicard, M and Chevalier, F and De Vlechouver, M and Bouchon, D and Grève, P and Braquart-Varnier, C}, title = {Variations of immune parameters in terrestrial isopods: a matter of gender, aging and Wolbachia.}, journal = {Die Naturwissenschaften}, volume = {97}, number = {9}, pages = {819-826}, pmid = {20676599}, issn = {1432-1904}, mesh = {Aging ; Animals ; Crosses, Genetic ; Female ; Feminization ; Hemocytes/cytology/microbiology ; Hemolymph/physiology ; Immunocompetence ; Isopoda/*genetics/growth &amp; development/immunology/microbiology ; Male ; Phenotype ; Sex Characteristics ; Sex Chromosomes/genetics ; Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Ecological factors modulate animal immunocompetence and potentially shape the evolution of their immune systems. Not only environmental parameters impact on immunocompetence: Aging is one major cause of variability of immunocompetence between individuals, and sex-specific levels of immunocompetence have also been frequently described. Moreover, a growing core of data put in light that vertically transmitted symbionts can dramatically modulate the immunocompetence of their hosts. In this study, we addressed the influence of gender, age and the feminising endosymbiont Wolbachia (wVulC) on variations in haemocyte density, total PO activity and bacterial load in the haemolymph of the terrestrial isopod Armadillidium vulgare. This host-symbiont system is of particular interest to address this question since: (1) wVulC was previously shown as immunosuppressive in middle-aged females and (2) wVulC influences sex determination. We show that age, gender and Wolbachia modulate together immune parameters in A. vulgare. However, wVulC, which interacts with aging, appears to be the prominent factor interfering with both PO activity and haemocyte density. This interference with immune parameters is not the only aspect of wVulC virulence on its host, as reproduction and survival are also altered.}, }
@article {pmid20675572, year = {2010}, author = {Groth, M and Takeda, N and Perry, J and Uchida, H and Dräxl, S and Brachmann, A and Sato, S and Tabata, S and Kawaguchi, M and Wang, TL and Parniske, M}, title = {NENA, a Lotus japonicus homolog of Sec13, is required for rhizodermal infection by arbuscular mycorrhiza fungi and rhizobia but dispensable for cortical endosymbiotic development.}, journal = {The Plant cell}, volume = {22}, number = {7}, pages = {2509-2526}, pmid = {20675572}, issn = {1532-298X}, support = {BBS/E/J/00000150/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Cloning, Molecular ; Genetic Complementation Test ; Lotus/*metabolism ; Molecular Sequence Data ; Mutation ; Mycorrhizae/*pathogenicity ; Plant Proteins/*physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Rhizobium/*pathogenicity ; *Symbiosis ; Two-Hybrid System Techniques ; }, abstract = {Legumes form symbioses with arbuscular mycorrhiza (AM) fungi and nitrogen fixing root nodule bacteria. Intracellular root infection by either endosymbiont is controlled by the activation of the calcium and calmodulin-dependent kinase (CCaMK), a central regulatory component of the plant's common symbiosis signaling network. We performed a microscopy screen for Lotus japonicus mutants defective in AM development and isolated a mutant, nena, that aborted fungal infection in the rhizodermis. NENA encodes a WD40 repeat protein related to the nucleoporins Sec13 and Seh1. Localization of NENA to the nuclear rim and yeast two-hybrid experiments indicated a role for NENA in a conserved subcomplex of the nuclear pore scaffold. Although nena mutants were able to form pink nodules in symbiosis with Mesorhizobium loti, root hair infection was not observed. Moreover, Nod factor induction of the symbiotic genes NIN, SbtM4, and SbtS, as well as perinuclear calcium spiking, were impaired. Detailed phenotypic analyses of nena mutants revealed a rhizobial infection mode that overcame the lack of rhizodermal responsiveness and carried the hallmarks of crack entry, including a requirement for ethylene. CCaMK-dependent processes were only abolished in the rhizodermis but not in the cortex of nena mutants. These data support the concept of tissue-specific components for the activation of CCaMK.}, }
@article {pmid20675479, year = {2010}, author = {Heinz, E and Rockey, DD and Montanaro, J and Aistleitner, K and Wagner, M and Horn, M}, title = {Inclusion membrane proteins of Protochlamydia amoebophila UWE25 reveal a conserved mechanism for host cell interaction among the Chlamydiae.}, journal = {Journal of bacteriology}, volume = {192}, number = {19}, pages = {5093-5102}, pmid = {20675479}, issn = {1098-5530}, support = {R01 AI048769/AI/NIAID NIH HHS/United States ; U19 AI031448/AI/NIAID NIH HHS/United States ; AI48769/AI/NIAID NIH HHS/United States ; AI031448/AI/NIAID NIH HHS/United States ; }, mesh = {Acanthamoeba castellanii/microbiology ; Animals ; Bacterial Proteins/genetics/*metabolism ; Blotting, Western ; Chlamydia/genetics/*growth &amp; development/*metabolism/ultrastructure ; Membrane Proteins/genetics/*metabolism ; Microscopy, Immunoelectron ; }, abstract = {Chlamydiae are a group of obligate intracellular bacteria comprising several important human pathogens. Inside the eukaryotic cell, chlamydiae remain within a host-derived vesicular compartment, termed the inclusion. They modify the inclusion membrane through insertion of unique proteins, which are involved in interaction with and manipulation of the host cell. Among chlamydiae, inclusion membrane proteins have been exclusively found in members of the family Chlamydiaceae, which predominantly infect mammalian and avian hosts. Here, the presence of inclusion membrane proteins in Protochlamydia amoebophila UWE25, a chlamydial endosymbiont of free-living amoebae, is reported. A genome-wide screening for secondary structure motifs resulted in the identification of 23 putative inclusion membrane proteins for this organism. Immunofluorescence analysis demonstrated that five of these proteins were expressed, and four of them could be localized to a halo surrounding the intracellular bacteria. Colocalization studies showed an almost complete overlap of the signals obtained for the four putative inclusion membrane proteins, and immuno-transmission electron microscopy unambiguously demonstrated their location in the inclusion membrane. The presence of inclusion membrane proteins (designated IncA, IncQ, IncR, and IncS) in P. amoebophila shows that this strategy for host cell interaction is conserved among the chlamydiae and is used by chlamydial symbionts and pathogens alike.}, }
@article {pmid23766232, year = {2010}, author = {Nakamura, S and Matsuo, J and Hayashi, Y and Kawaguchi, K and Yoshida, M and Takahashi, K and Mizutani, Y and Yao, T and Yamaguchi, H}, title = {Endosymbiotic bacterium Protochlamydia can survive in acanthamoebae following encystation.}, journal = {Environmental microbiology reports}, volume = {2}, number = {4}, pages = {611-618}, doi = {10.1111/j.1758-2229.2010.00182.x}, pmid = {23766232}, issn = {1758-2229}, abstract = {Obligate intracellular bacteria are commonly seen as endosymbionts of acanthamoebae. However, whether endosymbionts can survive amoebal encystations remains a significant challenge in cellular biology. The survival of the endosymbiotic bacteria Protochlamydia belonging to environmental chlamydiae found in an amoebal isolate that we have previously reported (Environmental Microbiology Reports, DOI: 10.1111/j.1758-2229.2009.00094.x, 2009) following encystation was therefore assessed. The bacteria were observed in cysts and trophozoites reverted from cysts by analysis with transmission electron microscope, and the bacterial 16S rRNA transcripts were detected in amoeba cultures following encystations by reverse transcription polymerase chain reaction method. Furthermore, the bacterial growth was also confirmed, by fluorescent in situ hybridization analysis and the AIU assay that we have previously established (Applied Environmental Microbiology, 74: 6397-6404, 2008), in trophozoites reverted from cysts stored at 4°C for up to a month after encystation. Thus, these results demonstrated that Protochlamydia could survive in acanthamoebae following encystation. Our findings suggest that amoeba cysts might be further studied in order to understand their role in the environmental survival of endosymbionts.}, }
@article {pmid23766225, year = {2010}, author = {Ikeda-Ohtsubo, W and Faivre, N and Brune, A}, title = {Putatively free-living 'Endomicrobia'- ancestors of the intracellular symbionts of termite gut flagellates?.}, journal = {Environmental microbiology reports}, volume = {2}, number = {4}, pages = {554-559}, doi = {10.1111/j.1758-2229.2009.00124.x}, pmid = {23766225}, issn = {1758-2229}, abstract = {Endomicrobia represent a candidate class in the Elusimicrobia phylum (formerly Termite Group 1) and were originally described as obligate intracellular symbionts of gut flagellates in lower termites. However, 16S rRNA gene sequences of Endomicrobia have been detected also in the gut of insects that do not possess such flagellates, e.g. higher termites and cockroaches. When we eliminated the large gut flagellates of Reticulitermes santonensis by feeding a starch diet, we discovered novel lineages of Endomicrobia that were hitherto undetected in normally faunated specimens. The new phylotypes are clearly separated from the endosymbionts of gut flagellates and fall into the radiation of those from flagellate-free insects. Comprehensive phylogenetic analysis documented that Endomicrobia comprise an apical cluster of endosymbionts that is not necessarily monophyletic and several apparently basal lineages that include bacteria present in the gut of defaunated lower termites, the naturally flagellate-free guts of higher termites and scarab beetle larvae, and in the cow rumen. We propose that these lineages represent hitherto undetected free-living Endomicrobia that share a common ancestor with the intracellular symbionts.}, }
@article {pmid23766223, year = {2010}, author = {Matsuo, J and Kawaguchi, K and Nakamura, S and Hayashi, Y and Yoshida, M and Takahashi, K and Mizutani, Y and Yao, T and Yamaguchi, H}, title = {Survival and transfer ability of phylogenetically diverse bacterial endosymbionts in environmental Acanthamoeba isolates.}, journal = {Environmental microbiology reports}, volume = {2}, number = {4}, pages = {524-533}, doi = {10.1111/j.1758-2229.2009.00094.x}, pmid = {23766223}, issn = {1758-2229}, abstract = {Obligate intracellular bacteria are commonly found as endosymbionts of acanthamoebae; however, their survival in and ability to transfer to amoebae are currently uncharacterized. In this study, six bacterial endosymbionts, found in five environmental Acanthamoeba isolates (S13, R18, S23, S31, S40) from different locations of Sapporo city, Japan, were characterized. Phylogenetic analysis revealed that three bacterial endosymbionts (eS23, eS31, eS40a) belonged to α- and β-Proteobacteria phyla and the remaining endosymbionts (eS13, eR18, eS40b) belonged to the order Chlamydiales. The Acanthamoeba isolate (S40) contained two phylogenetically different bacterial endosymbionts (eS40a, eS40b). Fluorescent in situ hybridization analysis showed that all bacterial endosymbionts were diffusely localized within amoebae. Transmission electron microscopy also showed that the endosymbionts were rod-shaped (eS23, eS31, eS40a) or sphere- or crescent-shaped (eS13, eR18, eS40b). No successful culture of these bacteria was achieved using conventional culture methods, but the viability of endosymbionts was confirmed by live/dead staining and RT-PCR methods. However, endosymbionts (except eR18) derived from original host cells lost the ability to be transferred to another Acanthamoebae strains [ATCC strain (C3), environmental strains (S14, R23, S24)]. Thus, our data demonstrate that phylogenetically diverse bacterial endosymbionts found in amoebae maintain a stable interaction with amoebae, but the transferability is limited.}, }
@article {pmid22127169, year = {2010}, author = {Ramírez-Puebla, ST and Rosenblueth, M and Chávez-Moreno, CK and de Lyra, MC and Tecante, A and Martínez-Romero, E}, title = {Molecular phylogeny of the genus Dactylopius (Hemiptera: Dactylopiidae) and identification of the symbiotic bacteria.}, journal = {Environmental entomology}, volume = {39}, number = {4}, pages = {1178-1183}, doi = {10.1603/EN10037}, pmid = {22127169}, issn = {1938-2936}, mesh = {Animals ; Betaproteobacteria/*genetics/growth &amp; development ; Female ; Genes, Mitochondrial ; Genes, rRNA ; Hemiptera/*genetics/microbiology ; Mexico ; *Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Phylogenetic analyses, from polymerase chain reaction (PCR)-amplified 12S rRNA and 18S rRNA gene sequences from cochineal insects of the genus Dactylopius present in Mexico, showed that D. ceylonicus, D. confusus, and D. opuntiae are closely related. D. coccus constitutes a separate clade, and D. tomentosus is the most distantly related. Bacterial 16S rRNA sequences from all the Dactylopius species sampled showed a common β-proteobacteria, related to Azoarcus, also found in eggs and in bacteriocytes in D. coccus. We propose the name "Candidatus Dactylopiibacterium carminicum" for this endosymbiont. Other bacterial sequences recovered from the samples were close to those from soil or plant associated bacteria, like Massilia, Herbaspirillum, Acinetobacter, Mesorhizobium, and Sphingomonas, suggesting a possible horizontal transmission from Cactaceae plant sap to Dactylopius spp. during feeding. This is the first molecular analysis of Dactylopius species and of their associated bacteria.}, }
@article {pmid21966925, year = {2010}, author = {Verna, C and Ramette, A and Wiklund, H and Dahlgren, TG and Glover, AG and Gaill, F and Dubilier, N}, title = {High symbiont diversity in the bone-eating worm Osedax mucofloris from shallow whale-falls in the North Atlantic.}, journal = {Environmental microbiology}, volume = {12}, number = {8}, pages = {2355-2370}, doi = {10.1111/j.1462-2920.2010.02299.x}, pmid = {21966925}, issn = {1462-2920}, mesh = {Animals ; Bacteria/*classification/genetics ; *Biodiversity ; Bone and Bones ; DNA, Bacterial/genetics ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; *Phylogeny ; Polychaeta/*microbiology ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Whales ; }, abstract = {Osedax worms are whale-fall specialists that infiltrate whale bones with their root tissues. These are filled with endosymbiotic bacteria hypothesized to provide their hosts with nutrition by extracting organic compounds from the whale bones. We investigated the diversity and distribution of symbiotic bacteria in Osedax mucofloris from shallow-water whale-falls in the North Atlantic using comparative 16S rRNA sequence analysis and fluorescence in situ hybridization (FISH). We observed a higher diversity of endosymbionts than previously described from other Osedax species. Endosymbiont sequences fell into eight phylogenetically distinct clusters (with 91.4-98.9% similarity between clusters), and considerable microdiversity within clusters (99.5-99.7% similarity) was observed. Statistical tests revealed a highly significant effect of the host individual on endosymbiont diversity and distribution, with 68% of the variability between clusters and 40% of the variability within clusters explained by this effect. FISH analyses showed that most host individuals were dominated by endosymbionts from a single cluster, with endosymbionts from less abundant clusters generally confined to peripheral root tissues. The observed diversity and distribution patterns indicate that the endosymbionts are transmitted horizontally from the environment with repeated infection events occurring as the host root tissues grow into the whale bones.}, }
@article {pmid21966907, year = {2010}, author = {Desai, MS and Strassert, JF and Meuser, K and Hertel, H and Ikeda-Ohtsubo, W and Radek, R and Brune, A}, title = {Strict cospeciation of devescovinid flagellates and Bacteroidales ectosymbionts in the gut of dry-wood termites (Kalotermitidae).}, journal = {Environmental microbiology}, volume = {12}, number = {8}, pages = {2120-2132}, doi = {10.1111/j.1462-2920.2009.02080.x}, pmid = {21966907}, issn = {1462-2920}, mesh = {Animals ; Bacteroidetes/*classification/genetics ; Base Sequence ; DNA, Bacterial/genetics ; DNA, Protozoan/genetics ; Gastrointestinal Tract/microbiology ; Genes, rRNA ; *Genetic Speciation ; In Situ Hybridization, Fluorescence ; Isoptera/*microbiology ; Molecular Sequence Data ; Parabasalidea/*classification/genetics/microbiology/ultrastructure ; *Phylogeny ; *Symbiosis ; }, abstract = {The surface of many termite gut flagellates is colonized with a dense layer of bacteria, yet little is known about the evolutionary relationships of such ectosymbionts and their hosts. Here we investigated the molecular phylogenies of devescovinid flagellates (Devescovina spp.) and their symbionts from a wide range of dry-wood termites (Kalotermitidae). From species-pure flagellate suspensions isolated with micropipettes, we obtained SSU rRNA gene sequences of symbionts and host. Phylogenetic analysis showed that the Devescovina spp. present in many species of Kalotermitidae form a monophyletic group, which includes also the unique devescovinid flagellate Caduceia versatilis. All members of this group were consistently associated with a distinct lineage of Bacteroidales, whose location on the cell surface was confirmed by fluorescence in situ hybridization. The well-supported congruence of the phylogenies of devescovinids and their ectosymbionts documents a strict cospeciation. In contrast, the endosymbionts of the same flagellates ('Endomicrobia') were clearly polyphyletic and must have been acquired independently by horizontal transfer from other flagellate lineages. Also the Bacteroidales ectosymbionts of Oxymonas flagellates present in several Kalotermitidae belonged to several distantly related lines of descent, underscoring the general perception that the evolutionary history of flagellate-bacteria symbioses in the termite gut is complex.}, }
@article {pmid21966902, year = {2010}, author = {Degnan, PH and Leonardo, TE and Cass, BN and Hurwitz, B and Stern, D and Gibbs, RA and Richards, S and Moran, NA}, title = {Dynamics of genome evolution in facultative symbionts of aphids.}, journal = {Environmental microbiology}, volume = {12}, number = {8}, pages = {2060-2069}, pmid = {21966902}, issn = {1462-2920}, support = {/HHMI_/Howard Hughes Medical Institute/United States ; U54 HG003273/HG/NHGRI NIH HHS/United States ; }, mesh = {Animals ; Aphids/*microbiology ; Comparative Genomic Hybridization ; DNA, Bacterial/genetics ; Enterobacteriaceae/*genetics/physiology ; *Evolution, Molecular ; *Genome, Bacterial ; Genomic Islands ; Molecular Sequence Data ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Aphids are sap-feeding insects that host a range of bacterial endosymbionts including the obligate, nutritional mutualist Buchnera plus several bacteria that are not required for host survival. Among the latter, 'Candidatus Regiella insecticola' and 'Candidatus Hamiltonella defensa' are found in pea aphids and other hosts and have been shown to protect aphids from natural enemies. We have sequenced almost the entire genome of R. insecticola (2.07 Mbp) and compared it with the recently published genome of H. defensa (2.11 Mbp). Despite being sister species the two genomes are highly rearranged and the genomes only have ∼55% of genes in common. The functions encoded by the shared genes imply that the bacteria have similar metabolic capabilities, including only two essential amino acid biosynthetic pathways and active uptake mechanisms for the remaining eight, and similar capacities for host cell toxicity and invasion (type 3 secretion systems and RTX toxins). These observations, combined with high sequence divergence of orthologues, strongly suggest an ancient divergence after establishment of a symbiotic lifestyle. The divergence in gene sets and in genome architecture implies a history of rampant recombination and gene inactivation and the ongoing integration of mobile DNA (insertion sequence elements, prophage and plasmids).}, }
@article {pmid20659421, year = {2011}, author = {Hewitt, V and Alcock, F and Lithgow, T}, title = {Minor modifications and major adaptations: the evolution of molecular machines driving mitochondrial protein import.}, journal = {Biochimica et biophysica acta}, volume = {1808}, number = {3}, pages = {947-954}, doi = {10.1016/j.bbamem.2010.07.019}, pmid = {20659421}, issn = {0006-3002}, mesh = {Animals ; Evolution, Molecular ; Humans ; Intracellular Membranes/*metabolism ; Membrane Proteins/*metabolism ; Mitochondria/*metabolism ; Mitochondrial Proteins/*metabolism ; Protein Transport ; }, abstract = {Bacterial endosymbionts gave rise to mitochondria in a process that depended on the acquisition of protein import pathways. Modification and in some cases major re-tooling of the endosymbiont's cellular machinery produced these pathways, establishing mitochondria as organelles common to all eukaryotic cells. The legacy of this evolutionary tinkering can be seen in the homologies and structural similarities between mitochondrial protein import machinery and modern day bacterial proteins. Comparative analysis of these systems is revealing both possible routes for the evolution of the mitochondrial membrane translocases and a greater understanding of the mechanisms behind mitochondrial protein import. This article is part of a Special Issue entitled Protein translocation across or insertion into membranes.}, }
@article {pmid20651929, year = {2010}, author = {Sonthayanon, P and Peacock, SJ and Chierakul, W and Wuthiekanun, V and Blacksell, SD and Holden, MT and Bentley, SD and Feil, EJ and Day, NP}, title = {High rates of homologous recombination in the mite endosymbiont and opportunistic human pathogen Orientia tsutsugamushi.}, journal = {PLoS neglected tropical diseases}, volume = {4}, number = {7}, pages = {e752}, pmid = {20651929}, issn = {1935-2735}, support = {/WT_/Wellcome Trust/United Kingdom ; 073135/WT_/Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Bacterial Typing Techniques/methods ; DNA Fingerprinting/methods ; DNA, Bacterial/chemistry/genetics ; Humans ; Mites/microbiology ; Orientia tsutsugamushi/*genetics/isolation &amp; purification ; *Polymorphism, Genetic ; *Recombination, Genetic ; Scrub Typhus/microbiology ; Sequence Analysis, DNA/methods ; }, abstract = {Orientia tsutsugamushi is an intracellular alpha-proteobacterium which resides in trombiculid mites, and is the causative agent of scrub typhus in East Asia. The genome sequence of this species has revealed an unprecedented number of repeat sequences, most notably of the genes encoding the conjugative properties of a type IV secretion system (T4SS). Although this observation is consistent with frequent intragenomic recombination, the extent of homologous recombination (gene conversion) in this species is unknown. To address this question, and to provide a protocol for the epidemiological surveillance of this important pathogen, we have developed a multilocus sequence typing (MLST) scheme based on 7 housekeeping genes (gpsA, mdh, nrdB, nuoF, ppdK, sucD, sucB). We applied this scheme to the two published genomes, and to DNA extracted from blood taken from 84 Thai scrub typhus patients, from 20 cultured Thai patient isolates, 1 Australian patient sample, and from 3 cultured type strains. These data demonstrated that the O. tsutsugamushi population was both highly diverse [Simpson's index (95% CI) = 0.95 (0.92-0.98)], and highly recombinogenic. These results are surprising given the intracellular life-style of this species, but are broadly consistent with results obtained for Wolbachia, which is an alpha-proteobacterial reproductive parasite of arthropods. We also compared the MLST data with ompA sequence data and noted low levels of consistency and much higher discrimination by MLST. Finally, twenty-five percent of patients in this study were simultaneously infected with multiple sequence types, suggesting multiple infection caused by either multiple mite bites, or multiple strains co-existing within individual mites.}, }
@article {pmid20649993, year = {2010}, author = {Belda, E and Moya, A and Bentley, S and Silva, FJ}, title = {Mobile genetic element proliferation and gene inactivation impact over the genome structure and metabolic capabilities of Sodalis glossinidius, the secondary endosymbiont of tsetse flies.}, journal = {BMC genomics}, volume = {11}, number = {}, pages = {449}, pmid = {20649993}, issn = {1471-2164}, mesh = {Animals ; DNA Transposable Elements/genetics ; Enterobacteriaceae/*genetics/*metabolism ; *Gene Silencing ; Genes, Bacterial/*genetics ; *Genomics ; Prophages/genetics ; Pseudogenes/genetics ; *Symbiosis ; *Tsetse Flies ; }, abstract = {BACKGROUND: Genome reduction is a common evolutionary process in symbiotic and pathogenic bacteria. This process has been extensively characterized in bacterial endosymbionts of insects, where primary mutualistic bacteria represent the most extreme cases of genome reduction consequence of a massive process of gene inactivation and loss during their evolution from free-living ancestors. Sodalis glossinidius, the secondary endosymbiont of tsetse flies, contains one of the few complete genomes of bacteria at the very beginning of the symbiotic association, allowing to evaluate the relative impact of mobile genetic element proliferation and gene inactivation over the structure and functional capabilities of this bacterial endosymbiont during the transition to a host dependent lifestyle.<br><br>RESULTS: A detailed characterization of mobile genetic elements and pseudogenes reveals a massive presence of different types of prophage elements together with five different families of IS elements that have proliferated across the genome of Sodalis glossinidius at different levels. In addition, a detailed survey of intergenic regions allowed the characterization of 1501 pseudogenes, a much higher number than the 972 pseudogenes described in the original annotation. Pseudogene structure reveals a minor impact of mobile genetic element proliferation in the process of gene inactivation, with most of pseudogenes originated by multiple frameshift mutations and premature stop codons. The comparison of metabolic profiles of Sodalis glossinidius and tsetse fly primary endosymbiont Wiglesworthia glossinidia based on their whole gene and pseudogene repertoires revealed a novel case of pathway inactivation, the arginine biosynthesis, in Sodalis glossinidius together with a possible case of metabolic complementation with Wigglesworthia glossinidia for thiamine biosynthesis.<br><br>CONCLUSIONS: The complete re-analysis of the genome sequence of Sodalis glossinidius reveals novel insights in the evolutionary transition from a free-living ancestor to a host-dependent lifestyle, with a massive proliferation of mobile genetic elements mainly of phage origin although with minor impact in the process of gene inactivation that is taking place in this bacterial genome. The metabolic analysis of the whole endosymbiotic consortia of tsetse flies have revealed a possible phenomenon of metabolic complementation between primary and secondary endosymbionts that can contribute to explain the co-existence of both bacterial endosymbionts in the context of the tsetse host.}, }
@article {pmid20638265, year = {2010}, author = {Jewett, MC and Forster, AC}, title = {Update on designing and building minimal cells.}, journal = {Current opinion in biotechnology}, volume = {21}, number = {5}, pages = {697-703}, pmid = {20638265}, issn = {1879-0429}, support = {R00 GM081450/GM/NIGMS NIH HHS/United States ; R01 AI072453/AI/NIAID NIH HHS/United States ; }, mesh = {Bioengineering/*methods ; Biotechnology/*methods ; Cells/*metabolism ; Genome, Bacterial/genetics ; }, abstract = {Minimal cells comprise only the genes and biomolecular machinery necessary for basic life. Synthesizing minimal and minimized cells will improve understanding of core biology, enhance development of biotechnology strains of bacteria, and enable evolutionary optimization of natural and unnatural biopolymers. Design and construction of minimal cells is proceeding in two different directions: 'top-down' reduction of bacterial genomes in vivo and 'bottom-up' integration of DNA/RNA/protein/membrane syntheses in vitro. Major progress in the past 5 years has occurred in synthetic genomics, minimization of the Escherichia coli genome, sequencing of minimal bacterial endosymbionts, identification of essential genes, and integration of biochemical systems.}, }
@article {pmid20636907, year = {2010}, author = {Bodył, A and Mackiewicz, P and Stiller, JW}, title = {Comparative genomic studies suggest that the cyanobacterial endosymbionts of the amoeba Paulinella chromatophora possess an import apparatus for nuclear-encoded proteins.}, journal = {Plant biology (Stuttgart, Germany)}, volume = {12}, number = {4}, pages = {639-649}, doi = {10.1111/j.1438-8677.2009.00264.x}, pmid = {20636907}, issn = {1438-8677}, mesh = {Amino Acid Motifs ; Amoeba/*microbiology ; Bacterial Proteins/genetics/*metabolism ; Cell Nucleus/metabolism ; *Comparative Genomic Hybridization ; Cyanobacteria/*genetics ; DNA, Bacterial/genetics ; Evolution, Molecular ; Genome, Bacterial ; Membrane Proteins/genetics/metabolism ; Nuclear Proteins/genetics/*metabolism ; Phylogeny ; Plastids/metabolism ; Protein Transport ; Symbiosis ; }, abstract = {Plastids evolved from free-living cyanobacteria through a process of primary endosymbiosis. The most widely accepted hypothesis derives three ancient lineages of primary plastids, i.e. those of glaucophytes, red algae and green plants, from a single cyanobacterial endosymbiosis. This hypothesis was originally predicated on the assumption that transformations of endosymbionts into organelles must be exceptionally rare because of the difficulty in establishing efficient protein trafficking between a host cell and incipient organelle. It turns out, however, that highly integrated endosymbiotic associations are more common than once thought. Among them is the amoeba Paulinella chromatophora, which harbours independently acquired cyanobacterial endosymbionts functioning as plastids. Sequencing of the Paulinella endosymbiont genome revealed an absence of essential genes for protein trafficking, suggesting their residence in the host nucleus and import of protein products back into the endosymbiont. To investigate this hypothesis, we searched the Paulinella endosymbiont genome for homologues of higher plant translocon proteins that form the import apparatus in two-membrane envelopes of primary plastids. We found homologues of Toc12, Tic21 and Tic32, but genes for other key translocon proteins (e.g. Omp85/Toc75 and Tic20) were missing. We propose that these missing genes were transferred to the Paulinella nucleus and their products are imported and integrated into the endosymbiont envelope membranes, thereby creating an effective protein import apparatus. We further suggest that other bacterial/cyanobacterial endosymbionts found in protists, plants and animals could have evolved efficient protein import systems independently and, therefore, reached the status of true cellular organelles.}, }
@article {pmid20628610, year = {2010}, author = {Ran, L and Larsson, J and Vigil-Stenman, T and Nylander, JA and Ininbergs, K and Zheng, WW and Lapidus, A and Lowry, S and Haselkorn, R and Bergman, B}, title = {Genome erosion in a nitrogen-fixing vertically transmitted endosymbiotic multicellular cyanobacterium.}, journal = {PloS one}, volume = {5}, number = {7}, pages = {e11486}, pmid = {20628610}, issn = {1932-6203}, mesh = {Biological Evolution ; Cyanobacteria/*genetics/*growth &amp; development ; Ferns/*microbiology ; Genome, Bacterial/*genetics ; Nitrogen Fixation/genetics/physiology ; Symbiosis/genetics/*physiology ; }, abstract = {BACKGROUND: An ancient cyanobacterial incorporation into a eukaryotic organism led to the evolution of plastids (chloroplasts) and subsequently to the origin of the plant kingdom. The underlying mechanism and the identities of the partners in this monophyletic event remain elusive.<br><br>To shed light on this evolutionary process, we sequenced the genome of a cyanobacterium residing extracellularly in an endosymbiosis with a plant, the water-fern Azolla filiculoides Lam. This symbiosis was selected as it has characters which make it unique among extant cyanobacterial plant symbioses: the cyanobacterium lacks autonomous growth and is vertically transmitted between plant generations. Our results reveal features of evolutionary significance. The genome is in an eroding state, evidenced by a large proportion of pseudogenes (31.2%) and a high frequency of transposable elements (approximately 600) scattered throughout the genome. Pseudogenization is found in genes such as the replication initiator dnaA and DNA repair genes, considered essential to free-living cyanobacteria. For some functional categories of genes pseudogenes are more prevalent than functional genes. Loss of function is apparent even within the 'core' gene categories of bacteria, such as genes involved in glycolysis and nutrient uptake. In contrast, serving as a critical source of nitrogen for the host, genes related to metabolic processes such as cell differentiation and nitrogen-fixation are well preserved.<br><br>CONCLUSIONS/SIGNIFICANCE: This is the first finding of genome degradation in a plant symbiont and phenotypically complex cyanobacterium and one of only a few extracellular endosymbionts described showing signs of reductive genome evolution. Our findings suggest an ongoing selective streamlining of this cyanobacterial genome which has resulted in an organism devoted to nitrogen fixation and devoid of autonomous growth. The cyanobacterial symbiont of Azolla can thus be considered at the initial phase of a transition from free-living organism to a nitrogen-fixing plant entity, a transition process which may mimic what drove the evolution of chloroplasts from a cyanobacterial ancestor.}, }
@article {pmid20628578, year = {2010}, author = {Majerus, TM and Majerus, ME}, title = {Intergenomic arms races: detection of a nuclear rescue gene of male-killing in a ladybird.}, journal = {PLoS pathogens}, volume = {6}, number = {7}, pages = {e1000987}, pmid = {20628578}, issn = {1553-7374}, mesh = {Animals ; Biological Evolution ; Coleoptera/*genetics/*microbiology ; Female ; Genes, Bacterial ; Male ; Sex Characteristics ; *Sex Ratio ; Symbiosis/*genetics ; *Wolbachia ; }, abstract = {Many species of arthropod are infected by deleterious inherited micro-organisms. Typically these micro-organisms are inherited maternally. Consequently, some, particularly bacteria of the genus Wolbachia, employ a variety of strategies that favour female over male hosts. These strategies include feminisation, induction of parthenogenesis and male-killing. These strategies result in female biased sex ratios in host populations, which lead to selection for host factors that promote male production. In addition, the intra-genomic conflict produced by the difference in transmission of these cytoplasmic endosymbionts and nuclear factors will impose a pressure favouring nuclear factors that suppress the effects of the symbiont. During investigations of the diversity of male-killing bacteria in ladybirds (Coccinellidae), unexpected patterns of vertical transmission of a newly discovered male-killing taxon were observed in the ladybird Cheilomenes sexmaculata. Initial analysis suggested that the expression of the bacterial male-killing trait varies according to the male(s) a female has mated with. By swapping males between females, a male influence on the expression of the male-killing trait was confirmed. Experiments were then performed to determine the nature of the interaction. These studies showed that a single dominant allele, which rescues male progeny of infected females from the pathological effect of the male-killer, exists in this species. The gene shows typical Mendelian autosomal inheritance and is expressed irrespective of the parent from which it is inherited. Presence of the rescue gene in either parent does not significantly affect the inheritance of the symbiont. We conclude that C. sexmaculata is host to a male-killing gamma-proteobacterium. Further, this beetle is polymorphic for a nuclear gene, the dominant allele of which rescues infected males from the pathogenic effects of the male-killing agent. These findings represent the first reported case of a nuclear suppressor of male-killing in a ladybird. They are considered in regard to sex ratio and intra-genomic conflict theories, and models of the evolutionary dynamics and distribution of inherited symbionts.}, }
@article {pmid20628417, year = {2011}, author = {Higashiura, Y and Yamaguchi, H and Ishihara, M and Ono, N and Tsukagoshi, H and Yokobori, S and Tokishita, S and Yamagata, H and Fukatsu, T}, title = {Male death resulting from hybridization between subspecies of the gypsy moth, Lymantria dispar.}, journal = {Heredity}, volume = {106}, number = {4}, pages = {603-613}, pmid = {20628417}, issn = {1365-2540}, mesh = {Animals ; Bacteria/genetics ; Base Sequence ; Female ; *Hybridization, Genetic ; Insect Proteins/genetics ; Japan ; Male ; Molecular Sequence Data ; Moths/*genetics/microbiology/physiology ; Sex Ratio ; Species Specificity ; Symbiosis ; }, abstract = {We explored the origin of all-female broods resulting from male death in a Hokkaido population of Lymantria dispar through genetic crosses based on the earlier experiments done by Goldschmidt and by testing for the presence of endosymbionts that are known to cause male killing in some insect species. The mitochondrial DNA haplotypes of the all-female broods in Hokkaido were different from those of normal Hokkaido females and were the same as those widely distributed in Asia, including Tokyo (TK). Goldschmidt obtained all-female broods through backcrossing, that is, F1 females obtained by a cross between TK females (L. dispar japonica) and Hokkaido males (L. dispar praeterea) mated with Hokkaido males. He also obtained all-male broods by mating Hokkaido females with TK males. Goldschmidt inferred that female- and male-determining factors were weakest in the Hokkaido subspecies and stronger in the Honshu (TK) subspecies. According to his theory, the females of all-female broods mated with Honshu males should produce normal sex-ratio broods, whereas weaker Hokkaido sexes would be expected to disappear in F1 or F2 generations after crossing with the Honshu subspecies. We confirmed both of Goldschmidt's results: in the case of all-female broods mated with Honshu males, normal sex-ratio broods were produced, but we obtained only all-female broods in the Goldschmidt backcross and obtained an all-male brood in the F1 generation of a Hokkaido female crossed with a TK male. We found no endosymbionts in all-female broods by 4,'6-diamidino-2-phenylindole (DAPI) staining. Therefore, the all-female broods observed in L. dispar are caused by some incompatibilities between Honshu and Hokkaido subspecies.}, }
@article {pmid20618908, year = {2010}, author = {Michel, G and Tonon, T and Scornet, D and Cock, JM and Kloareg, B}, title = {Central and storage carbon metabolism of the brown alga Ectocarpus siliculosus: insights into the origin and evolution of storage carbohydrates in Eukaryotes.}, journal = {The New phytologist}, volume = {188}, number = {1}, pages = {67-81}, doi = {10.1111/j.1469-8137.2010.03345.x}, pmid = {20618908}, issn = {1469-8137}, mesh = {Carbohydrate Metabolism/*genetics ; Carbon/*metabolism ; Carbon Cycle/genetics ; *Evolution, Molecular ; Genome/genetics ; Phaeophyta/enzymology/*metabolism ; Phylogeny ; Starch/metabolism ; Symbiosis ; }, abstract = {• Brown algae exhibit a unique carbon (C) storage metabolism. The photoassimilate D-fructose 6-phosphate is not used to produce sucrose but is converted into D-mannitol. These seaweeds also store C as β-1,3-glucan (laminarin), thus markedly departing from most living organisms, which use α-1,4-glucans (glycogen or starch). • Using a combination of bioinformatic and phylogenetic approaches, we identified the candidate genes for the enzymes involved in C storage in the genome of the brown alga Ectocarpus siliculosus and traced their evolutionary origins. • Ectocarpus possesses a complete set of enzymes for synthesis of mannitol, laminarin and trehalose. By contrast, the pathways for sucrose, starch and glycogen are completely absent. • The synthesis of β-1,3-glucans appears to be a very ancient eukaryotic pathway. Brown algae inherited the trehalose pathway from the red algal progenitor of phaeoplasts, while the mannitol pathway was acquired by lateral gene transfer from Actinobacteria. The starch metabolism of the red algal endosymbiont was entirely lost in the ancestor of Stramenopiles. In light of these novel findings we question the validity of the 'Chromalveolate hypothesis'.}, }
@article {pmid20618907, year = {2010}, author = {Michel, G and Tonon, T and Scornet, D and Cock, JM and Kloareg, B}, title = {The cell wall polysaccharide metabolism of the brown alga Ectocarpus siliculosus. Insights into the evolution of extracellular matrix polysaccharides in Eukaryotes.}, journal = {The New phytologist}, volume = {188}, number = {1}, pages = {82-97}, doi = {10.1111/j.1469-8137.2010.03374.x}, pmid = {20618907}, issn = {1469-8137}, mesh = {Alginates/metabolism ; Biosynthetic Pathways ; Cell Wall/*metabolism ; Cellulose/biosynthesis ; *Evolution, Molecular ; Extracellular Matrix/*metabolism ; Phaeophyta/enzymology/*genetics/*metabolism ; Phylogeny ; Polysaccharides/biosynthesis/*metabolism ; }, abstract = {• Brown algal cell walls share some components with plants (cellulose) and animals (sulfated fucans), but they also contain some unique polysaccharides (alginates). Analysis of the Ectocarpus genome provides a unique opportunity to decipher the molecular bases of these crucial metabolisms. • An extensive bioinformatic census of the enzymes potentially involved in the biogenesis and remodeling of cellulose, alginate and fucans was performed, and completed by phylogenetic analyses of key enzymes. • The routes for the biosynthesis of cellulose, alginates and sulfated fucans were reconstructed. Surprisingly, known families of cellulases, expansins and alginate lyases are absent in Ectocarpus, suggesting the existence of novel mechanisms and/or proteins for cell wall expansion in brown algae. • Altogether, our data depict a complex evolutionary history for the main components of brown algal cell walls. Cellulose synthesis was inherited from the ancestral red algal endosymbiont, whereas the terminal steps for alginate biosynthesis were acquired by horizontal gene transfer from an Actinobacterium. This horizontal gene transfer event also contributed genes for hemicellulose biosynthesis. By contrast, the biosynthetic route for sulfated fucans is an ancestral pathway, conserved with animals. These findings shine a new light on the origin and evolution of cell wall polysaccharides in other Eukaryotes.}, }
@article {pmid20616105, year = {2010}, author = {Tommassen, J}, title = {Assembly of outer-membrane proteins in bacteria and mitochondria.}, journal = {Microbiology (Reading, England)}, volume = {156}, number = {Pt 9}, pages = {2587-2596}, doi = {10.1099/mic.0.042689-0}, pmid = {20616105}, issn = {1465-2080}, mesh = {Bacteria/chemistry/genetics/*metabolism ; Bacterial Outer Membrane Proteins/chemistry/genetics/*metabolism ; Bacterial Proteins/chemistry/genetics/metabolism ; Mitochondria/chemistry/genetics/*metabolism ; Protein Structure, Secondary ; }, abstract = {The cell envelope of Gram-negative bacteria consists of two membranes separated by the periplasm. In contrast with most integral membrane proteins, which span the membrane in the form of hydrophobic alpha-helices, integral outer-membrane proteins (OMPs) form beta-barrels. Similar beta-barrel proteins are found in the outer membranes of mitochondria and chloroplasts, probably reflecting the endosymbiont origin of these eukaryotic cell organelles. How these beta-barrel proteins are assembled into the outer membrane has remained enigmatic for a long time. In recent years, much progress has been reached in this field by the identification of the components of the OMP assembly machinery. The central component of this machinery, called Omp85 or BamA, is an essential and highly conserved bacterial protein that recognizes a signature sequence at the C terminus of its substrate OMPs. A homologue of this protein is also found in mitochondria, where it is required for the assembly of beta-barrel proteins into the outer membrane as well. Although accessory components of the machineries are different between bacteria and mitochondria, a mitochondrial beta-barrel OMP can be assembled into the bacterial outer membrane and, vice versa, bacterial OMPs expressed in yeast are assembled into the mitochondrial outer membrane. These observations indicate that the basic mechanism of OMP assembly is evolutionarily highly conserved.}, }
@article {pmid20614011, year = {2010}, author = {Bai, X and Zhang, W and Orantes, L and Jun, TH and Mittapalli, O and Mian, MA and Michel, AP}, title = {Combining next-generation sequencing strategies for rapid molecular resource development from an invasive aphid species, Aphis glycines.}, journal = {PloS one}, volume = {5}, number = {6}, pages = {e11370}, pmid = {20614011}, issn = {1932-6203}, mesh = {Animals ; Aphids/genetics/*physiology ; DNA, Complementary ; Genetic Markers ; Genome, Insect ; Microsatellite Repeats/genetics ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; }, abstract = {BACKGROUND: Aphids are one of the most important insect taxa in terms of ecology, evolutionary biology, genetics and genomics, and interactions with endosymbionts. Additionally, many aphids are serious pest species of agricultural and horticultural plants. Recent genetic and genomic research has expanded molecular resources for many aphid species, including the whole genome sequencing of the pea aphid, Acrythosiphon pisum. However, the invasive soybean aphid, Aphis glycines, lacks in any significant molecular resources.<br><br>Two next-generation sequencing technologies (Roche-454 and Illumina GA-II) were used in a combined approach to develop both transcriptomic and genomic resources, including expressed genes and molecular markers. Over 278 million bp were sequenced among the two methods, resulting in 19,293 transcripts and 56,688 genomic sequences. From this data set, 635 SNPs and 1,382 microsatellite markers were identified. For each sequencing method, different soybean aphid biotypes were used which revealed potential biotype specific markers. In addition, we uncovered 39,822 bp of sequence that were related to the obligatory endosymbiont, Buchnera aphidicola, as well as sequences that suggest the presence of Hamiltonella defensa, a facultative endosymbiont.<br><br>CONCLUSIONS AND SIGNIFICANCE: Molecular resources for an invasive, non-model aphid species were generated. Additionally, the power of next-generation sequencing to uncover endosymbionts was demonstrated. The resources presented here will complement ongoing molecular studies within the Aphididae, including the pea aphid whole genome, lead to better understanding of aphid adaptation and evolution, and help provide novel targets for soybean aphid control.}, }
@article {pmid20606691, year = {2011}, author = {White, JA and Kelly, SE and Cockburn, SN and Perlman, SJ and Hunter, MS}, title = {Endosymbiont costs and benefits in a parasitoid infected with both Wolbachia and Cardinium.}, journal = {Heredity}, volume = {106}, number = {4}, pages = {585-591}, pmid = {20606691}, issn = {1365-2540}, support = {2 K12 GM00708-06/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteroidetes/*physiology ; Female ; *Host-Pathogen Interactions ; Male ; Reproduction ; *Symbiosis ; Wasps/genetics/*microbiology/physiology ; Wolbachia/*physiology ; }, abstract = {Theory suggests that maternally inherited endosymbionts can promote their spread and persistence in host populations by enhancing the production of daughters by infected hosts, either by improving overall host fitness, or through reproductive manipulation. In the doubly infected parasitoid wasp Encarsia inaron, Wolbachia manipulates host reproduction through cytoplasmic incompatibility (CI), but Cardinium does not. We investigated the fitness costs and/or benefits of infection by each bacterium in differentially cured E. inaron as a potential explanation for persistence of Cardinium in this population. We introgressed lines infected with Wolbachia, Cardinium or both with the cured line to create a similar genetic background, and evaluated several parasitoid fitness parameters. We found that symbiont infection resulted in both fitness costs and benefits for E. inaron. The cost was lower initial egg load for all infected wasps. The benefit was increased survivorship, which in turn increased male production for wasps infected with only Cardinium. Female production was unaffected by symbiont infection; we therefore have not yet identified a causal fitness effect that can explain the persistence of Cardinium in the population. Interestingly, the Cardinium survivorship benefit was not evident when Wolbachia was also present in the host, and the reproduction of doubly infected individuals did not differ significantly from uninfected wasps. Therefore, the results of our study show that even when multiple infections seem to have no effect on a host, there may be a complex interaction of costs and benefits among symbionts.}, }
@article {pmid20603211, year = {2010}, author = {Crainey, JL and Hurst, J and Wilson, MD and Hall, A and Post, RJ}, title = {Construction and characterisation of a BAC library made from field specimens of the onchocerciasis vector Simulium squamosum (Diptera: Simuliidae).}, journal = {Genomics}, volume = {96}, number = {4}, pages = {251-257}, doi = {10.1016/j.ygeno.2010.06.004}, pmid = {20603211}, issn = {1089-8646}, support = {G0600015/MRC_/Medical Research Council/United Kingdom ; 77615/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Base Sequence ; Chromosome Mapping ; Chromosomes, Artificial, Bacterial/*genetics ; Cloning, Molecular ; *Disease Vectors ; Genes, Insect/genetics ; *Genomic Library ; Humans ; Microsatellite Repeats/genetics ; Onchocerciasis/parasitology/*transmission ; Simuliidae/*genetics/growth &amp; development ; Specimen Handling/methods ; Wolbachia/genetics ; }, abstract = {A Bacterial Artificial Chromosome (BAC) library was made from wild-caught Simulium squamosum, which is an important vector of human onchocerciasis. The library is composed of 12,288 BACs, with an average insert size of 128 kb, and is expected to contain ~1.54 GB of cloned DNA. Random BAC-end sequencing generated over 95 kb of DNA sequence data from which putative S. squamosum gene sequences and novel repetitive DNA families were identified, including DNA transposons, retrotransposons and simple sequence repeats (SSRs). The sequence survey also provided evidence of DNA of microbial origin, and dissection of sample blackflies indicated that some of those used to prepare the library were likely to be parasitized by the mermithid Isomermis lairdi. Hybridisations with a set of three independent blackfly single-copy genes and two Wolbachia genes suggest that the library provides around 13-fold coverage of the S. squamosum genome and about 12-fold coverage of its Wolbachia endosymbiont.}, }
@article {pmid20597434, year = {2010}, author = {Martin, C and Gavotte, L}, title = {The bacteria Wolbachia in filariae, a biological Russian dolls' system: new trends in antifilarial treatments.}, journal = {Parasite (Paris, France)}, volume = {17}, number = {2}, pages = {79-89}, doi = {10.1051/parasite/2010172079}, pmid = {20597434}, issn = {1252-607X}, mesh = {Animals ; Anthelmintics/therapeutic use ; Arthropods/microbiology ; Filariasis/*drug therapy/*microbiology/transmission ; Filarioidea/genetics/microbiology ; Gram-Negative Bacteria/isolation &amp; purification ; Humans ; Vertebrates/parasitology ; Wolbachia/*genetics ; Wuchereria bancrofti/microbiology ; }, abstract = {Filarial nematode species can host Wolbachia bacterial endosymbionts. To understand the symbiosis, a higher level of complexity should be considered, taking in account the tripartite association between Wolbachia, filariae and mammals. This overview article discusses the biology of Wolbachia in filariae, including their distribution and phylogeny, mechanisms of action, inflammatory consequences on mammal host and biological control implications for filariases. Potential directions for future research are also discussed.}, }
@article {pmid20592260, year = {2010}, author = {Engelstädter, J}, title = {The effective size of populations infected with cytoplasmic sex-ratio distorters.}, journal = {Genetics}, volume = {186}, number = {1}, pages = {309-320}, pmid = {20592260}, issn = {1943-2631}, mesh = {Animals ; Cell Nucleus/genetics ; Cytoplasm/*genetics ; Diploidy ; Female ; Feminization/genetics ; Genes, Mitochondrial/genetics ; Male ; *Models, Genetic ; Pedigree ; Population Density ; Probability ; *Sex Ratio ; Symbiosis/genetics ; }, abstract = {Many arthropod species are infected with maternally inherited endosymbionts that induce a shift in the sex ratio of their hosts by feminizing or killing males (cytoplasmic sex-ratio distorters, or SRDs). These endosymbionts can have profound impacts on evolutionary processes of their hosts. Here, I derive analytical expressions for the coalescent effective size N(e) of populations that are infected with SRDs. Irrespective of the type of SRD, N(e) for mitochondrial genes is given by the number of infected females. For nuclear genes, the effective population size generally decreases with increasing prevalence of the SRD and can be considerably lower than the actual size of the population. For example, with male-killing bacteria that have near perfect maternal transmission, N(e) is reduced by a factor that is given to a good approximation by the proportion of uninfected individuals in the population. The formulae derived here also yield the effective size of populations infected with mutualistic endosymbionts or maternally inherited bacteria that induce cytoplasmic incompatibility, although in these cases, the reduction in N(e) is expected to be less severe than for cytoplasmic SRDs.}, }
@article {pmid20576760, year = {2010}, author = {Colleoni, C and Linka, M and Deschamps, P and Handford, MG and Dupree, P and Weber, AP and Ball, SG}, title = {Phylogenetic and biochemical evidence supports the recruitment of an ADP-glucose translocator for the export of photosynthate during plastid endosymbiosis.}, journal = {Molecular biology and evolution}, volume = {27}, number = {12}, pages = {2691-2701}, doi = {10.1093/molbev/msq158}, pmid = {20576760}, issn = {1537-1719}, support = {BB/D010446/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; D11626/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/D010446/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Adenosine Diphosphate Glucose/metabolism ; Arabidopsis/genetics/metabolism ; Cyanobacteria/genetics/metabolism ; Nucleotide Transport Proteins/*genetics/metabolism ; Photosynthesis/*genetics ; *Phylogeny ; Plastids/genetics/*metabolism ; Protein Transport ; Saccharomyces cerevisiae/genetics/metabolism ; Starch/metabolism ; *Symbiosis ; }, abstract = {The acquisition of photosynthesis by eukaryotic cells through enslavement of a cyanobacterium represents one of the most remarkable turning points in the history of life on Earth. In addition to endosymbiotic gene transfer, the acquisition of a protein import apparatus and the coordination of gene expression between host and endosymbiont genomes, the establishment of a metabolic connection was crucial for a functional endosymbiosis. It was previously hypothesized that the first metabolic connection between both partners of endosymbiosis was achieved through insertion of a host-derived metabolite transporter into the cyanobacterial plasma membrane. Reconstruction of starch metabolism in the common ancestor of photosynthetic eukaryotes suggested that adenosine diphosphoglucose (ADP-Glc), a bacterial-specific metabolite, was likely to be the photosynthate, which was exported from the early cyanobiont. However, extant plastid transporters that have evolved from host-derived endomembrane transporters do not transport ADP-Glc but simple phosphorylated sugars in exchange for orthophosphate. We now show that those eukaryotic nucleotide sugar transporters, which define the closest relatives to the common ancestor of extant plastid envelope carbon translocators, possess an innate ability for transporting ADP-Glc. Such an unexpected ability would have been required to establish plastid endosymbiosis.}, }
@article {pmid20575645, year = {2011}, author = {de Carvalho, IL and Santos, N and Soares, T and Zé-Zé, L and Núncio, MS}, title = {Francisella-like endosymbiont in Dermacentor reticulatus collected in Portugal.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {11}, number = {2}, pages = {185-188}, doi = {10.1089/vbz.2010.0014}, pmid = {20575645}, issn = {1557-7759}, mesh = {Animals ; Dermacentor/*microbiology ; Female ; Francisella/classification/genetics/*physiology ; Male ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Portugal ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {In Portugal, recent studies have confirmed the presence of Francisella tularensis in Dermacentor reticulatus. Bacterial endosymbionts with significant homology to F. tularensis have been described in several species of ticks. In this work we identified Francisella-like endosymbionts in D. reticulatus ticks (39%), confirming the presence of these bacteria in Portugal. This finding should be considered in future studies using molecular approaches to detect Francisella prevalence in ticks and environmental samples.}, }
@article {pmid20569494, year = {2010}, author = {Tijsse-Klasen, E and Fonville, M and van Overbeek, L and Reimerink, JH and Sprong, H}, title = {Exotic Rickettsiae in Ixodes ricinus: fact or artifact?.}, journal = {Parasites &amp; vectors}, volume = {3}, number = {}, pages = {54}, pmid = {20569494}, issn = {1756-3305}, abstract = {Several pathogenic Rickettsia species can be transmitted via Ixodes ricinus ticks to humans and animals. Surveys of I. ricinus for the presence of Rickettsiae using part of its 16S rRNA gene yield a plethora of new and different Rickettsia sequences. Interpreting these data is sometimes difficult and presenting these findings as new or potentially pathogenic Rickettsiae should be done with caution: a recent report suggested presence of a known human pathogen, R. australis, in questing I. ricinus ticks in Europe. A refined analysis of these results revealed that R. helvetica was most likely to be misinterpreted as R. australis. Evidence in the literature is accumulating that rickettsial DNA sequences found in tick lysates can also be derived from other sources than viable, pathogenic Rickettsiae. For example, from endosymbionts, environmental contamination or even horizontal gene transfer.}, }
@article {pmid20568636, year = {2010}, author = {Swanevelder, ZH and Surridge, AK and Venter, E and Botha, AM}, title = {Limited endosymbiont variation in Diuraphis noxia (Hemiptera: Aphididae) biotypes from the United States and South Africa.}, journal = {Journal of economic entomology}, volume = {103}, number = {3}, pages = {887-897}, doi = {10.1603/ec09257}, pmid = {20568636}, issn = {0022-0493}, mesh = {Animals ; Base Sequence ; Buchnera/*genetics ; Female ; Gene Dosage ; Hemiptera/*microbiology ; Molecular Sequence Data ; Plasmids/chemistry/genetics ; Sequence Analysis, DNA ; South Africa ; *Symbiosis ; United States ; }, abstract = {Symbiosis allows an insect access to imbalanced food sources on which other organisms cannot survive. A bacterial endosymbiont, Buchnera aphidicola, gives aphids the ability to feed on phloem depleted of certain essential amino acids by producing those required. Pseudogenes and lower plasmid copy numbers of essential amino acid genes in B. aphidicola, endosymbiont of the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), suggest that this symbiotic relationship is degenerating. The complete endosymbiont assemblages, copy numbers of plasmids (important in essential amino acid production), and sequence variation in B. aphidicola, from 10 Russian wheat aphid biotypes, were investigated. B. aphidicola was found to be monosymbiotic in the Russian wheat aphid biotypes and other Diuraphis species examined. An insert, occurring in an inverted repeat region on the leucine plasmid, was the only variation found in the approximately 10-kb B. aphidicola sequence analyzed from each Russian wheat aphid biotype. This inverted repeat was shown previously to be conserved within the family Aphididae. The insert occurred in B. aphidicola sequences isolated from four Russian wheat aphid biotypes. Copy numbers of the leucine plasmid differ between the South African and U.S. biotypes and were similar to previously reported values for biotypes from the same geographic regions. These results suggest that B. aphidicola may still contribute to Russian wheat aphid fitness when the aphid feeds on a variety of hosts.}, }
@article {pmid20566863, year = {2010}, author = {Kirkness, EF and Haas, BJ and Sun, W and Braig, HR and Perotti, MA and Clark, JM and Lee, SH and Robertson, HM and Kennedy, RC and Elhaik, E and Gerlach, D and Kriventseva, EV and Elsik, CG and Graur, D and Hill, CA and Veenstra, JA and Walenz, B and Tubío, JM and Ribeiro, JM and Rozas, J and Johnston, JS and Reese, JT and Popadic, A and Tojo, M and Raoult, D and Reed, DL and Tomoyasu, Y and Kraus, E and Mittapalli, O and Margam, VM and Li, HM and Meyer, JM and Johnson, RM and Romero-Severson, J and Vanzee, JP and Alvarez-Ponce, D and Vieira, FG and Aguadé, M and Guirao-Rico, S and Anzola, JM and Yoon, KS and Strycharz, JP and Unger, MF and Christley, S and Lobo, NF and Seufferheld, MJ and Wang, N and Dasch, GA and Struchiner, CJ and Madey, G and Hannick, LI and Bidwell, S and Joardar, V and Caler, E and Shao, R and Barker, SC and Cameron, S and Bruggner, RV and Regier, A and Johnson, J and Viswanathan, L and Utterback, TR and Sutton, GG and Lawson, D and Waterhouse, RM and Venter, JC and Strausberg, RL and Berenbaum, MR and Collins, FH and Zdobnov, EM and Pittendrigh, BR}, title = {Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {107}, number = {27}, pages = {12168-12173}, pmid = {20566863}, issn = {1091-6490}, mesh = {Animals ; Enterobacteriaceae/genetics ; Genes, Bacterial/genetics ; Genes, Insect/genetics ; Genome, Bacterial/*genetics ; Genome, Insect/*genetics ; Genomics/methods ; Humans ; Lice Infestations/parasitology ; Molecular Sequence Data ; Pediculus/*genetics/*microbiology ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.}, }
@article {pmid20565933, year = {2010}, author = {Minge, MA and Shalchian-Tabrizi, K and Tørresen, OK and Takishita, K and Probert, I and Inagaki, Y and Klaveness, D and Jakobsen, KS}, title = {A phylogenetic mosaic plastid proteome and unusual plastid-targeting signals in the green-colored dinoflagellate Lepidodinium chlorophorum.}, journal = {BMC evolutionary biology}, volume = {10}, number = {}, pages = {191}, pmid = {20565933}, issn = {1471-2148}, mesh = {Amino Acid Sequence ; Dinoflagellida/classification/*genetics ; Evolution, Molecular ; Gene Library ; Gene Transfer, Horizontal ; Molecular Sequence Data ; *Phylogeny ; Plastids/*genetics/metabolism ; Proteome/*genetics ; RNA, Protozoan/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {BACKGROUND: Plastid replacements through secondary endosymbioses include massive transfer of genes from the endosymbiont to the host nucleus and require a new targeting system to enable transport of the plastid-targeted proteins across 3-4 plastid membranes. The dinoflagellates are the only eukaryotic lineage that has been shown to have undergone several plastid replacement events, and this group is thus highly relevant for studying the processes involved in plastid evolution. In this study, we analyzed the phylogenetic origin and N-terminal extensions of plastid-targeted proteins from Lepidodinium chlorophorum, a member of the only dinoflagellate genus that harbors a green secondary plastid rather than the red algal-derived, peridinin-containing plastid usually found in photosynthetic dinoflagellates.<br><br>RESULTS: We sequenced 4,746 randomly picked clones from a L. chlorophorum cDNA library. 22 of the assembled genes were identified as genes encoding proteins functioning in plastids. Some of these were of green algal origin. This confirms that genes have been transferred from the plastid to the host nucleus of L. chlorophorum and indicates that the plastid is fully integrated as an organelle in the host. Other nuclear-encoded plastid-targeted protein genes, however, are clearly not of green algal origin, but have been derived from a number of different algal groups, including dinoflagellates, streptophytes, heterokonts, and red algae. The characteristics of N-terminal plastid-targeting peptides of all of these genes are substantially different from those found in peridinin-containing dinoflagellates and green algae.<br><br>CONCLUSIONS: L. chlorophorum expresses plastid-targeted proteins with a range of different origins, which probably arose through endosymbiotic gene transfer (EGT) and horizontal gene transfer (HGT). The N-terminal extension of the genes is different from the extensions found in green alga and other dinoflagellates (peridinin- and haptophyte plastids). These modifications have likely enabled the mosaic proteome of L. chlorophorum.}, }
@article {pmid20559015, year = {2010}, author = {Senra, MV and Vizzoni, VF and Trindade-Silva, AE and Giannini, AL and Soares, CA}, title = {Genetic modification of Teredinibacter turnerae, an endosymbiont with biotechnological potential.}, journal = {Journal of molecular microbiology and biotechnology}, volume = {18}, number = {4}, pages = {215-219}, doi = {10.1159/000316422}, pmid = {20559015}, issn = {1660-2412}, mesh = {Animals ; Biotechnology/*methods ; Bivalvia/*microbiology ; *Conjugation, Genetic ; Escherichia coli/*genetics ; Gammaproteobacteria/*genetics/physiology ; Gene Expression Regulation, Bacterial ; Green Fluorescent Proteins/genetics/metabolism ; Isopropyl Thiogalactoside/pharmacology ; Nitrogen Fixation ; Plasmids ; *Symbiosis ; }, abstract = {Teredinibacter turnerae belongs to a group of biotechnologically relevant bacteria. Gene transfer into T. turnerae was achieved by using pPROBE'-gfp[ASV] derived plasmids through conjugative mating with Escherichia coli DH5alpha pRK2073. Transferred plasmids were stably maintained and T. turnerae could also act as a donor to transfer these mobilizable plasmids. Constructs for both constitutive and IPTG-inducible gene expression were obtained, representing new tools for gene overexpression in T. turnerae.}, }
@article {pmid20557208, year = {2010}, author = {Suzuki, TG and Ogino, K and Tsuneki, K and Furuya, H}, title = {Phylogenetic analysis of dicyemid mesozoans (phylum Dicyemida) from innexin amino acid sequences: dicyemids are not related to Platyhelminthes.}, journal = {The Journal of parasitology}, volume = {96}, number = {3}, pages = {614-625}, doi = {10.1645/GE-2305.1}, pmid = {20557208}, issn = {1937-2345}, mesh = {Amino Acid Sequence ; Animals ; Annelida/chemistry/classification/genetics ; Base Sequence ; Bayes Theorem ; Connexins/*chemistry/genetics ; Conserved Sequence ; DNA, Complementary/chemistry ; Decapodiformes/parasitology ; In Situ Hybridization ; Invertebrates/chemistry/*classification/genetics ; Likelihood Functions ; Mollusca/chemistry/classification/genetics ; Octopodiformes/parasitology ; *Phylogeny ; Platyhelminths/chemistry/classification/genetics ; Polymerase Chain Reaction/methods ; RNA/genetics/isolation &amp; purification ; Sequence Alignment ; }, abstract = {Dicyemid mesozoans are endoparasites, or endosymbionts, found only in the renal sac of benthic cephalopod molluscs. The body organization of dicyemids is very simple, consisting of usually 10 to 40 cells, with neither body cavities nor differentiated organs. Dicyemids were considered as primitive animals, and the out-group of all metazoans, or as occupying a basal position of lophotrochozoans close to flatworms. We cloned cDNAs encoding for the gap junction component proteins, innexin, from the dicyemids. Its expression pattern was observed by whole-mount in situ hybridization. In adult individuals, the innexin was expressed in calottes, infusorigens, and infusoriform embryos. The unique temporal pattern was observed in the developing infusoriform embryos. Innexin amino acid sequences had taxon-specific indels which enabled identification of the 3 major protostome lineages, i.e., 2 ecdysozoans (arthropods and nematodes) and the lophotrochozoans. The dicyemids show typical, lophotrochozoan-type indels. In addition, the Bayesian and maximum likelihood trees based on the innexin amino acid sequences suggested dicyemids to be more closely related to the higher lophotrochozoans than to the flatworms. Flatworms were the sister group, or consistently basal, to the other lophotrochozoan clade that included dicyemids, annelids, molluscs, and brachiopods.}, }
@article {pmid20550577, year = {2010}, author = {Rodrigues, CF and Webster, G and Cunha, MR and Duperron, S and Weightman, AJ}, title = {Chemosynthetic bacteria found in bivalve species from mud volcanoes of the Gulf of Cadiz.}, journal = {FEMS microbiology ecology}, volume = {73}, number = {3}, pages = {486-499}, doi = {10.1111/j.1574-6941.2010.00913.x}, pmid = {20550577}, issn = {1574-6941}, mesh = {Animals ; Bacteria/*genetics/isolation &amp; purification ; Bivalvia/*microbiology ; Carbon Isotopes/analysis ; DNA, Bacterial/genetics ; Gene Library ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {As in other cold seeps, the dominant bivalves in mud volcanoes (MV) from the Gulf of Cadiz are macrofauna belonging to the families Solemyidae (Acharax sp., Petrasma sp.), Lucinidae (Lucinoma sp.), Thyasiridae (Thyasira vulcolutre) and Mytilidae (Bathymodiolus mauritanicus). The delta(13)C values measured in solemyid, lucinid and thyasirid specimens support the hypothesis of thiotrophic nutrition, whereas isotopic signatures of B. mauritanicus suggest methanotrophic nutrition. The indication by stable isotope analysis that chemosynthetic bacteria make a substantial contribution to the nutrition of the bivalves led us to investigate their associated bacteria and their phylogenetic relationships based on comparative 16S rRNA gene sequence analysis. PCR-denaturing gradient gel electrophoresis analysis and cloning of bacterial 16S rRNA-encoding genes confirmed the presence of sulfide-oxidizing symbionts within gill tissues of many of the studied specimens. Phylogenetic analysis of bacterial 16S rRNA gene sequences demonstrated that most bacteria were related to known sulfide-oxidizing endosymbionts found in other deep-sea chemosynthetic environments, with the co-occurrence of methane-oxidizing symbionts in Bathymodiolus specimens. This study confirms the presence of several chemosynthetic bivalves in the Gulf of Cadiz and further highlights the importance of sulfide- and methane-oxidizing symbionts in the trophic ecology of macrobenthic communities in MV.}, }
@article {pmid20549377, year = {2010}, author = {Saito, H and Hashimoto, J}, title = {Characteristics of the fatty acid composition of a deep-sea vent gastropod, Ifremeria nautilei.}, journal = {Lipids}, volume = {45}, number = {6}, pages = {537-548}, pmid = {20549377}, issn = {1558-9307}, mesh = {Animals ; Docosahexaenoic Acids/chemistry/metabolism ; Eicosapentaenoic Acid/chemistry/metabolism ; Fatty Acids/*chemistry/metabolism ; Fatty Acids, Unsaturated/chemistry/metabolism ; Gastropoda/*metabolism ; Phospholipids/metabolism ; }, abstract = {Neutral and polar lipids in the soft parts of a gastropod species, Ifremeria nautilei, collected from deep-sea hydrothermal vents, were examined to assess the trophic relationships in hydrothermal vents. The vent gastropod obtains many of its lipids from symbiotic chemosynthetic microorganisms. The major polyunsaturated fatty acids (PUFA) both in the triacylglycerols and phospholipids of the gastropod consist of a limited number of n-3 and n-6 PUFA: arachidonic acid (20:4n-6), icosapentaenoic acid (20:5n-3), and docosapentaenoic acid (22:5n-3), without docosahexaenoic acid (DHA, 22:6n-3). Noticeable levels of various n-6 PUFA, such as 18:2n-6,9, 20:2n-6,9, 20:3n-6,9,12, and 20:3n-6,9,15 with significant levels of 16:1n-6 and 18:1n-6 indicate the biosynthetic characteristic of the endosymbionts. The lack of DHA in all specimens suggests a limitation of its lipid biosynthesis ability with its symbionts. This finding with regard to the lipids is unusual for a marine animal in the grazing or detrital food chain because many marine animal lipids evidently contain high levels of DHA with low levels of n-6 fatty acids. Such contradictory findings lead to some new insights into the absence of a biosynthetic pathway for DHA in I. nautilei, and provide evidence that DHA in this species is dispensable. Similar to herbivorous gastropods, the lack of DHA with significant levels of n-6 PUFA in this species also indicates its selective assimilation of specific microorganisms, such as chemosynthetic bacteria in hydrothermal vents, because significant levels of DHA were found in carnivorous mollusk lipids.}, }
@article {pmid20543958, year = {2010}, author = {McNulty, SN and Foster, JM and Mitreva, M and Dunning Hotopp, JC and Martin, J and Fischer, K and Wu, B and Davis, PJ and Kumar, S and Brattig, NW and Slatko, BE and Weil, GJ and Fischer, PU}, title = {Endosymbiont DNA in endobacteria-free filarial nematodes indicates ancient horizontal genetic transfer.}, journal = {PloS one}, volume = {5}, number = {6}, pages = {e11029}, pmid = {20543958}, issn = {1932-6203}, support = {T32 AI007172/AI/NIAID NIH HHS/United States ; T32-AI007172/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/*genetics ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Nematoda/*microbiology ; RNA, Messenger/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; *Symbiosis ; Wolbachia/*genetics/isolation &amp; purification ; }, abstract = {BACKGROUND: Wolbachia are among the most abundant symbiotic microbes on earth; they are present in about 66% of all insect species, some spiders, mites and crustaceans, and most filarial nematode species. Infected filarial nematodes, including many pathogens of medical and veterinary importance, depend on Wolbachia for proper development and survival. The mechanisms behind this interdependence are not understood. Interestingly, a minority of filarial species examined to date are naturally Wolbachia-free.<br><br>We used 454 pyrosequencing to survey the genomes of two distantly related Wolbachia-free filarial species, Acanthocheilonema viteae and Onchocerca flexuosa. This screen identified 49 Wolbachia-like DNA sequences in A. viteae and 114 in O. flexuosa. qRT-PCR reactions detected expression of 30 Wolbachia-like sequences in A. viteae and 56 in O. flexuosa. Approximately half of these appear to be transcribed from pseudogenes. In situ hybridization showed that two of these pseudogene transcripts were specifically expressed in developing embryos and testes of both species.<br><br>CONCLUSIONS/SIGNIFICANCE: These results strongly suggest that the last common ancestor of extant filarial nematodes was infected with Wolbachia and that this former endosymbiont contributed to their genome evolution. Horizontally transferred Wolbachia DNA may explain the ability of some filarial species to live and reproduce without the endosymbiont while other species cannot.}, }
@article {pmid20534454, year = {2010}, author = {Janouskovec, J and Horák, A and Oborník, M and Lukes, J and Keeling, PJ}, title = {A common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {107}, number = {24}, pages = {10949-10954}, pmid = {20534454}, issn = {1091-6490}, support = {MOP 84265//Canadian Institutes of Health Research/Canada ; }, mesh = {Apicomplexa/classification/*genetics/ultrastructure ; Base Sequence ; Dinoflagellida/classification/*genetics/ultrastructure ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Genome, Plastid ; Microscopy, Electron, Transmission ; Models, Genetic ; Molecular Sequence Data ; Photosynthesis/genetics ; Phylogeny ; Plastids/*genetics/ultrastructure ; Poly U/genetics ; RNA, Messenger/genetics ; Rhodophyta/classification/*genetics/ultrastructure ; Ribulose-Bisphosphate Carboxylase/genetics ; Symbiosis/genetics ; }, abstract = {The discovery of a nonphotosynthetic plastid in malaria and other apicomplexan parasites has sparked a contentious debate about its evolutionary origin. Molecular data have led to conflicting conclusions supporting either its green algal origin or red algal origin, perhaps in common with the plastid of related dinoflagellates. This distinction is critical to our understanding of apicomplexan evolution and the evolutionary history of endosymbiosis and photosynthesis; however, the two plastids are nearly impossible to compare due to their nonoverlapping information content. Here we describe the complete plastid genome sequences and plastid-associated data from two independent photosynthetic lineages represented by Chromera velia and an undescribed alga CCMP3155 that we show are closely related to apicomplexans. These plastids contain a suite of features retained in either apicomplexan (four plastid membranes, the ribosomal superoperon, conserved gene order) or dinoflagellate plastids (form II Rubisco acquired by horizontal transfer, transcript polyuridylylation, thylakoids stacked in triplets) and encode a full collective complement of their reduced gene sets. Together with whole plastid genome phylogenies, these characteristics provide multiple lines of evidence that the extant plastids of apicomplexans and dinoflagellates were inherited by linear descent from a common red algal endosymbiont. Our phylogenetic analyses also support their close relationship to plastids of heterokont algae, indicating they all derive from the same endosymbiosis. Altogether, these findings support a relatively simple path of linear descent for the evolution of photosynthesis in a large proportion of algae and emphasize plastid loss in several lineages (e.g., ciliates, Cryptosporidium, and Phytophthora).}, }
@article {pmid20533041, year = {2011}, author = {Yun, Y and Lei, C and Peng, Y and Liu, F and Chen, J and Chen, L}, title = {Wolbachia strains typing in different geographic population spider, Hylyphantes graminicola (Linyphiidae).}, journal = {Current microbiology}, volume = {62}, number = {1}, pages = {139-145}, pmid = {20533041}, issn = {1432-0991}, mesh = {Animals ; Arachnida/*microbiology ; Bacterial Typing Techniques ; China ; Genotype ; Geography ; Multilocus Sequence Typing ; Phylogeny ; Symbiosis ; Wolbachia/*classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {The Wolbachia endosymbiont of spiders has not been extensively examined. In order to investigate the distribution, evolutionary history, and reproductive phenotype of Wolbachia in spiders in China, we tested 11 geographic populations of Hylyphantes graminicola. Wolbachia infection has been detected in each population. 10 Wolbachia strains have been characterized by multilocus sequence typing (MLST). Phylogenetic analyses indicated that eight Wolbachia strains in H. graminicola belonged to supergroup B, and two belonged to supergroup A. No correlation existed between Wolbachia diversity and host's geographic distance. The significant correlation was observed between pairwise distance of H. graminicola COI and genetic divergence of associated Wolbachia strains. We also found that Wolbachia infection frequencies in hosts varied over geographic space.}, }
@article {pmid20529072, year = {2010}, author = {Littman, RA and Bourne, DG and Willis, BL}, title = {Responses of coral-associated bacterial communities to heat stress differ with Symbiodinium type on the same coral host.}, journal = {Molecular ecology}, volume = {19}, number = {9}, pages = {1978-1990}, doi = {10.1111/j.1365-294X.2010.04620.x}, pmid = {20529072}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*microbiology/physiology ; DNA, Bacterial/genetics ; Dinoflagellida/*physiology ; Gene Library ; Host-Pathogen Interactions ; *Hot Temperature ; Larva/microbiology/physiology ; Photosynthesis ; Polymorphism, Single-Stranded Conformational ; Principal Component Analysis ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Vibrio/*genetics ; }, abstract = {This study compared the effect of heat stress on coral-associated bacterial communities among juveniles of the coral, Acropora tenuis, hosting different Symbiodinium types. In comparison to a control temperature treatment (28 degrees C), we documented dramatic changes in bacterial associates on juvenile corals harbouring ITS 1 type D Symbiodinium when placed in a high (32 degrees C) temperature treatment. In particular, there was a marked increase in the number of retrieved Vibrio affiliated sequences, which coincided with a 44% decline in the photochemical efficiency of the D-juveniles. Interestingly, these Vibrio sequences affiliated most closely with the coral pathogen, Vibrio coralliilyticus, which has been implicated in some coral disease outbreaks. In contrast, A. tenuis hosting ITS 1 type C1 Symbiodinium did not exhibit major bacterial shifts in the elevated temperature treatment, indicating a more stable bacterial community during thermal stress; concomitantly a decline (10%) in photochemical efficiency was minimal for this group. D juveniles that had been exposed to moderately elevated sea temperatures (30 degrees C) in the field before being placed in the control temperature treatment displayed a decrease in the number of Vibrio affiliated sequences and bacterial profiles shifted to become more similar to profiles of corals harbouring type C1 Symbiodinium. In combination, these results demonstrate that thermal stress can result in shifts in coral-associated bacterial communities, which may lead to deteriorating coral health. The lower resilience of A. tenuis to thermal stress when harbouring Symbiodinium D highlights the importance of inter-kingdom interactions among the coral host, dinoflagellate endosymbiont and bacterial associates for coral health and resilience.}, }
@article {pmid20528687, year = {2010}, author = {Shiflett, AM and Johnson, PJ}, title = {Mitochondrion-related organelles in eukaryotic protists.}, journal = {Annual review of microbiology}, volume = {64}, number = {}, pages = {409-429}, pmid = {20528687}, issn = {1545-3251}, support = {T32 A1007323//PHS HHS/United States ; F32 A108004//PHS HHS/United States ; R37 A127857//PHS HHS/United States ; R01 A1069058//PHS HHS/United States ; R37 AI027857/AI/NIAID NIH HHS/United States ; }, mesh = {Eukaryota/*genetics/*metabolism/ultrastructure ; *Genes, Mitochondrial ; Iron-Sulfur Proteins/metabolism ; Metabolic Networks and Pathways ; Mitochondria/*genetics/*metabolism/ultrastructure ; Phylogeny ; Sequence Homology ; }, abstract = {The discovery of mitochondrion-type genes in organisms thought to lack mitochondria led to the demonstration that hydrogenosomes share a common ancestry with mitochondria, as well as the discovery of mitosomes in multiple eukaryotic lineages. No examples of examined eukaryotes lacking a mitochondrion-related organelle exist, implying that the endosymbiont that gave rise to the mitochondrion was present in the first eukaryote. These organelles, known as hydrogenosomes, mitosomes, or mitochondrion-like organelles, are typically reduced, both structurally and biochemically, relative to classical mitochondria. However, despite their diversification and adaptation to different niches, all appear to play a role in Fe-S cluster assembly, as observed for mitochondria. Although evidence supports the use of common protein targeting mechanisms in the biogenesis of these diverse organelles, divergent features are also apparent. This review examines the metabolism and biogenesis of these organelles in divergent unicellular microbes, with a focus on parasitic protists.}, }
@article {pmid20515696, year = {2010}, author = {Chang, J and Masters, A and Avery, A and Werren, JH}, title = {A divergent Cardinium found in daddy long-legs (Arachnida: Opiliones).}, journal = {Journal of invertebrate pathology}, volume = {105}, number = {3}, pages = {220-227}, doi = {10.1016/j.jip.2010.05.017}, pmid = {20515696}, issn = {1096-0805}, mesh = {Animals ; Arachnida/*microbiology ; Base Sequence ; Incidence ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal/genetics ; *Symbiosis ; Wolbachia/*genetics ; }, abstract = {Recent studies indicate that a newly described bacterial endosymbiont, Cardinium, is widespread in arthropods and induces different reproductive manipulations in hosts. In this study, we used a portion of the 16S rRNA gene of the Cardinium to screen 16 Opilionid species from the suborder Palptores. We found the incidence of Cardinium in these Opiliones was significantly higher than in other pooled arthropods (31.2% versus 7.2%, P=0.007). Phylogenetic analyses using maximum parsimony (MP) and Bayesian analysis revealed two distinct clades in Opiliones. One is a divergent monophyletic clade with strong support that has so far not been found in other arthropods, and a second one contains Cardinium both from Opiliones and other arthropods. There is not complete concordance of the Cardinium strains with host phylogeny, suggesting some horizontal movement of the bacteria among Opiliones. Although the divergence in the sequenced 16S rRNA region between the Cardinium infecting Opiliones and Cardinium from other arthropods is greater than among Cardinium found in other arthropods, all are monophyletic with respect to the outgroup bacteria (endosymbionts of Acanthamoeba). Based on high pairwise genetic distances, deep branch, and a distinct phylogenetic grouping, we conclude that some Opiliones harbor a newly discovered Cardinium clade.}, }
@article {pmid20504228, year = {2010}, author = {Vervust, B and Pafilis, P and Valakos, ED and Van Damme, R}, title = {Anatomical and physiological changes associated with a recent dietary shift in the lizard Podarcis sicula.}, journal = {Physiological and biochemical zoology : PBZ}, volume = {83}, number = {4}, pages = {632-642}, doi = {10.1086/651704}, pmid = {20504228}, issn = {1537-5293}, mesh = {Animals ; Digestion/physiology ; Feces/chemistry/microbiology ; Feeding Behavior/*physiology ; Gastrointestinal Tract/anatomy &amp; histology/physiology ; Geography ; Head/*anatomy &amp; histology ; Lizards/anatomy &amp; histology/*physiology ; Tooth/anatomy &amp; histology ; }, abstract = {Dietary shifts have played a major role in the evolution of many vertebrates. The idea that the evolution of herbivory is physiologically constrained in squamates is challenged by a number of observations that suggest that at least some lizards can overcome the putative physiological difficulties of herbivory on evolutionary and even ecological timescales. We compared a number of morphological and physiological traits purportedly associated with plant consumption between two island populations of the lacertid lizard Podarcis sicula. Previous studies revealed considerable differences in the amount of plant material consumed between those populations. We continued the investigation of this study system and explored the degree of divergence in morphology (dentition, gut morphology), digestive performance (gut passage time, digestive efficiency), and ecology (endosymbiont density). In addition, we also performed a preliminary analysis of the plasticity of some of these modifications. Our results confirm and expand earlier findings concerning divergence in the morphology of feeding structures between two island populations of P. sicula lizards. In addition to the differences in skull dimensions and the prevalence of cecal valves previously reported, these two recently diverged populations also differ in aspects of their dentition (teeth width) and the lengths of the stomach and small intestine. The plasticity experiment suggests that at least some of the changes associated with a dietary shift toward a higher proportion of plant material may be plastic. Our results also show that these morphological changes effectively translate into differences in digestive performance: the population with the longer digestive tract exhibits longer gut passage time and improved digestive efficiency.}, }
@article {pmid20482639, year = {2010}, author = {Shigenobu, S and Bickel, RD and Brisson, JA and Butts, T and Chang, CC and Christiaens, O and Davis, GK and Duncan, EJ and Ferrier, DE and Iga, M and Janssen, R and Lin, GW and Lu, HL and McGregor, AP and Miura, T and Smagghe, G and Smith, JM and van der Zee, M and Velarde, RA and Wilson, MJ and Dearden, PK and Stern, DL}, title = {Comprehensive survey of developmental genes in the pea aphid, Acyrthosiphon pisum: frequent lineage-specific duplications and losses of developmental genes.}, journal = {Insect molecular biology}, volume = {19 Suppl 2}, number = {}, pages = {47-62}, doi = {10.1111/j.1365-2583.2009.00944.x}, pmid = {20482639}, issn = {1365-2583}, support = {BBS/B/12067/2/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; K99ES017367/ES/NIEHS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/*growth &amp; development/pathogenicity ; Body Patterning/genetics ; Female ; Gene Deletion ; Gene Duplication ; Genes, Homeobox ; *Genes, Insect ; Genome, Insect ; Insect Proteins/genetics ; Male ; Molecular Sequence Data ; Peas/parasitology ; Phylogeny ; Receptors, Cytoplasmic and Nuclear/genetics ; Sequence Homology, Amino Acid ; Signal Transduction/genetics ; Transcription Factors/genetics ; }, abstract = {Aphids exhibit unique attributes, such as polyphenisms and specialized cells to house endosymbionts, that make them an interesting system for studies at the interface of ecology, evolution and development. Here we present a comprehensive characterization of the developmental genes in the pea aphid, Acyrthosiphon pisum, and compare our results to other sequenced insects. We investigated genes involved in fundamental developmental processes such as establishment of the body plan and organogenesis, focusing on transcription factors and components of signalling pathways. We found that most developmental genes were well conserved in the pea aphid, although many lineage-specific gene duplications and gene losses have occurred in several gene families. In particular, genetic components of transforming growth factor beta (TGFbeta) Wnt, JAK/STAT (Janus kinase/signal transducer and activator of transcription) and EGF (Epidermal Growth Factor) pathways appear to have been significantly modified in the pea aphid.}, }
@article {pmid20502891, year = {2010}, author = {Finney, JC and Pettay, DT and Sampayo, EM and Warner, ME and Oxenford, HA and LaJeunesse, TC}, title = {The relative significance of host-habitat, depth, and geography on the ecology, endemism, and speciation of coral endosymbionts in the genus Symbiodinium.}, journal = {Microbial ecology}, volume = {60}, number = {1}, pages = {250-263}, pmid = {20502891}, issn = {1432-184X}, mesh = {Animals ; Anthozoa/*microbiology ; Caribbean Region ; DNA, Ribosomal Spacer/genetics ; Dinoflagellida/classification/*genetics ; *Ecosystem ; Geography ; Microsatellite Repeats ; Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {Dinoflagellates in the genus Symbiodinium are among the most abundant and important group of eukaryotic microbes found in coral reef ecosystems. Recent analyses conducted on various host cnidarians indicated that Symbiodinium assemblages in the Caribbean Sea are genetically and ecologically diverse. In order to further characterize this diversity and identify processes important to its origins, samples from six orders of Cnidaria comprising 45 genera were collected from reef habitats around Barbados (eastern Caribbean) and from the Mesoamerican barrier reef off the coast of Belize (western Caribbean). Fingerprinting of the ribosomal internal transcribed spacer 2 identified 62 genetically different Symbiodinium. Additional analyses of clade B Symbiodinium using microsatellite flanker sequences unequivocally characterized divergent lineages, or "species," within what was previously thought to be a single entity (B1 or B184). In contrast to the Indo-Pacific where host-generalist symbionts dominate many coral communities, partner specificity in the Caribbean is relatively high and is influenced little by the host's apparent mode of symbiont acquisition. Habitat depth (ambient light) and geographic isolation appeared to influence the bathymetric zonation and regional distribution for most of the Symbiodinium spp. characterized. Approximately 80% of Symbiodinium types were endemic to either the eastern or western Caribbean and 40-50% were distributed to compatible hosts living in shallow, high-irradiance, or deep, low-irradiance environments. These ecologic, geographic, and phylogenetic patterns indicate that most of the present Symbiodinium diversity probably originated from adaptive radiations driven by ecological specialization in separate Caribbean regions during the Pliocene and Pleistocene periods.}, }
@article {pmid20502706, year = {2010}, author = {Imanian, B and Pombert, JF and Keeling, PJ}, title = {The complete plastid genomes of the two 'dinotoms' Durinskia baltica and Kryptoperidinium foliaceum.}, journal = {PloS one}, volume = {5}, number = {5}, pages = {e10711}, pmid = {20502706}, issn = {1932-6203}, mesh = {Base Composition/genetics ; Conserved Sequence/genetics ; Dinoflagellida/*genetics ; Genes, Protozoan/genetics ; Genome, Plastid/*genetics ; Plasmids/genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {BACKGROUND: In one small group of dinoflagellates, photosynthesis is carried out by a tertiary endosymbiont derived from a diatom, giving rise to a complex cell that we collectively refer to as a 'dinotom'. The endosymbiont is separated from its host by a single membrane and retains plastids, mitochondria, a large nucleus, and many other eukaryotic organelles and structures, a level of complexity suggesting an early stage of integration. Although the evolution of these endosymbionts has attracted considerable interest, the plastid genome has not been examined in detail, and indeed no tertiary plastid genome has yet been sequenced.<br><br>Here we describe the complete plastid genomes of two closely related dinotoms, Durinskia baltica and Kryptoperidinium foliaceum. The D. baltica (116470 bp) and K. foliaceum (140426 bp) plastid genomes map as circular molecules featuring two large inverted repeats that separate distinct single copy regions. The organization and gene content of the D. baltica plastid closely resemble those of the pennate diatom Phaeodactylum tricornutum. The K. foliaceum plastid genome is much larger, has undergone more reorganization, and encodes a putative tyrosine recombinase (tyrC) also found in the plastid genome of the heterokont Heterosigma akashiwo, and two putative serine recombinases (serC1 and serC2) homologous to recombinases encoded by plasmids pCf1 and pCf2 in another pennate diatom, Cylindrotheca fusiformis. The K. foliaceum plastid genome also contains an additional copy of serC1, two degenerate copies of another plasmid-encoded ORF, and two non-coding regions whose sequences closely resemble portions of the pCf1 and pCf2 plasmids.<br><br>CONCLUSIONS/SIGNIFICANCE: These results suggest that while the plastid genomes of two dinotoms share very similar gene content and genome organization with that of the free-living pennate diatom P. tricornutum, the K. folicaeum plastid genome has absorbed two exogenous plasmids. Whether this took place before or after the tertiary endosymbiosis is not clear.}, }
@article {pmid20500529, year = {2010}, author = {Küchler, SM and Dettner, K and Kehl, S}, title = {Molecular characterization and localization of the obligate endosymbiotic bacterium in the birch catkin bug Kleidocerys resedae (Heteroptera: Lygaeidae, Ischnorhynchinae).}, journal = {FEMS microbiology ecology}, volume = {73}, number = {2}, pages = {408-418}, doi = {10.1111/j.1574-6941.2010.00890.x}, pmid = {20500529}, issn = {1574-6941}, mesh = {Animals ; DNA, Bacterial/genetics ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; Heteroptera/*microbiology ; Larva/microbiology ; *Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {In contrast to specific bacterial symbionts of many stinkbugs, which are harboured extracellularly in the lumina of midgut sacs or tubular outgrowths, the obligate endosymbiont of birch catkin bug Kleidocerys resedae (Heteroptera: Lygaeidae) resides in a red-coloured, raspberry-shaped mycetome, localized abdominally, close to the midgut section. Phylogenetic analysis, based on the 16S rRNA gene and the groEL (chaperonin) gene, showed that the bacteria belong to the gamma-subdivision of the Proteobacteria and revealed a phylogenetic relationship with bacterial endosymbionts of Wigglesworthia glossinidia, the primary symbiont of tse-tse fly Glossina brevipalpis. Furthermore, RFLP analysis and sequencing revealed that K. resedae was also infected by Alphaproteobacteria of the genera Wolbachia and Rickettsia. The distribution and transmission of Kleidocerys endosymbiont in adults and all nymph stages were studied using FISH. The detection of symbionts at the anterior poles of developing eggs indicated that endosymbionts are transmitted vertically to offspring. Ultrastructural examinations by electron microscopy revealed the packed accommodation of rod-shaped bacteria in the cytoplasm of mycetocytes. A new genus and species name, 'Candidatus Kleidoceria schneideri', is proposed for this newly characterized clade of symbiotic bacteria.}, }
@article {pmid20495935, year = {2010}, author = {Clark, EL and Karley, AJ and Hubbard, SF}, title = {Insect endosymbionts: manipulators of insect herbivore trophic interactions?.}, journal = {Protoplasma}, volume = {244}, number = {1-4}, pages = {25-51}, pmid = {20495935}, issn = {1615-6102}, mesh = {Animals ; Bacteria/genetics/*metabolism ; Feeding Behavior/*physiology ; Host-Parasite Interactions/*physiology ; Insecta/*microbiology ; Plants/*parasitology ; Symbiosis/genetics ; }, abstract = {Throughout their evolutionary history, insects have formed multiple relationships with bacteria. Although many of these bacteria are pathogenic, with deleterious effects on the fitness of infected insects, there are also numerous examples of symbiotic bacteria that are harmless or even beneficial to their insect host. Symbiotic bacteria that form obligate or facultative associations with insects and that are located intracellularly in the host insect are known as endosymbionts. Endosymbiosis can be a strong driving force for evolution when the acquisition and maintenance of a microorganism by the insect host results in the formation of novel structures or changes in physiology and metabolism. The complex evolutionary dynamics of vertically transmitted symbiotic bacteria have led to distinctive symbiont genome characteristics that have profound effects on the phenotype of the host insect. Symbiotic bacteria are key players in insect-plant interactions influencing many aspects of insect ecology and playing a key role in shaping the diversification of many insect groups. In this review, we discuss the role of endosymbionts in manipulating insect herbivore trophic interactions focussing on their impact on plant utilisation patterns and parasitoid biology.}, }
@article {pmid20485385, year = {2010}, author = {Leitsch, D and Köhsler, M and Marchetti-Deschmann, M and Deutsch, A and Allmaier, G and König, L and Sixt, BS and Duchêne, M and Walochnik, J}, title = {Proteomic aspects of Parachlamydia acanthamoebae infection in Acanthamoeba spp.}, journal = {The ISME journal}, volume = {4}, number = {11}, pages = {1366-1374}, doi = {10.1038/ismej.2010.68}, pmid = {20485385}, issn = {1751-7370}, mesh = {Acanthamoeba/*microbiology ; Animals ; Bacterial Proteins/*metabolism ; Chlamydiales/chemistry/growth &amp; development/*physiology ; Electrophoresis, Gel, Two-Dimensional ; *Host-Parasite Interactions ; Mass Spectrometry ; Proteome/*analysis ; Protozoan Proteins/*metabolism ; }, abstract = {The free-living but facultatively pathogenic amoebae of the genus Acanthamoeba are frequently infected with bacterial endosymbionts that can have a profound influence on the physiology and viability of their host. Parachlamydia acanthamoebae, a chlamydial endosymbiont in acanthamoebae, is known to be either symbiotic or lytic to its host, depending on the ambient conditions, for example, temperature. Moreover, parachlamydiae can also inhibit the encystment process in Acanthamoeba, an essential survival strategy of their host for the evasion of chemotherapeutic agents, heat, desiccation and radiation. To obtain a more detailed picture of the intracellular interactions of parachlamydiae and acanthamoebae, we studied parachlamydial infection in several Acanthamoeba isolates at the proteomic level by means of two-dimensional gel electrophoresis (2DE) and mass spectrometry. We observed that P. acanthamoebae can infect all three morphological subtypes of the genus Acanthamoeba and that the proteome pattern of released P. acanthamoebae elementary bodies was always practically identical regardless of the Acanthamoeba strain infected. Moreover, by comparing proteome patterns of encysting cells from infected and uninfected Acanthamoeba cultures, it was shown that encystment is blocked by P. acanthamoebae at a very early stage. Finally, on 2D-gels of purified P. acanthamoebae from culture supernatants, a subunit of the NADH-ubiquinone oxidoreductase complex, that is, an enzyme that has been described as an indicator for bacterial virulence was identified by a mass spectrometric and bioinformatic approach.}, }
@article {pmid20462452, year = {2010}, author = {Skaljac, M and Zanic, K and Ban, SG and Kontsedalov, S and Ghanim, M}, title = {Co-infection and localization of secondary symbionts in two whitefly species.}, journal = {BMC microbiology}, volume = {10}, number = {}, pages = {142}, pmid = {20462452}, issn = {1471-2180}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; Croatia ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Geography ; Hemiptera/*growth &amp; development/*microbiology ; In Situ Hybridization, Fluorescence ; Polymerase Chain Reaction ; Population Density ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: Whiteflies are cosmopolitan phloem-feeding pests that cause serious damage to many crops worldwide due to direct feeding and vectoring of many plant viruses. The sweetpotato whitefly Bemisia tabaci (Gennadius) and the greenhouse whitefly Trialeurodes vaporariorum (Westwood) are two of the most widespread and damaging whitefly species. To complete their unbalanced diet, whiteflies harbor the obligatory bacterium Portiera aleyrodidarum. B. tabaci further harbors a diverse array of secondary symbionts, including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea. T. vaporariorum is only known to harbor P. aleyrodidarum and Arsenophonus. We conducted a study to survey the distribution of whitefly species in Croatia, their infection status by secondary symbionts, and the spatial distribution of these symbionts in the developmental stages of the two whitefly species.<br><br>RESULTS: T. vaporariorum was found to be the predominant whitefly species across Croatia, while only the Q biotype of B. tabaci was found across the coastal part of the country. Arsenophonus and Hamiltonella were detected in collected T. vaporariorum populations, however, not all populations harbored both symbionts, and both symbionts showed 100% infection rate in some of the populations. Only the Q biotype of B. tabaci was found in the populations tested and they harbored Hamiltonella, Rickettsia, Wolbachia and Cardinium, while Arsenophonus and Fritschea were not detected in any B. tabaci populations. None of the detected symbionts appeared in all populations tested, and multiple infections were detected in some of the populations. All endosymbionts tested were localized inside the bacteriocyte in both species, but only Rickettsia and Cardinium in B. tabaci showed additional localization outside the bacteriocyte.<br><br>CONCLUSIONS: Our study revealed unique co-infection patterns by secondary symbionts in B. tabaci and T. vaporariorum. Co-sharing of the bacteriocyte by the primary and different secondary symbionts is maintained through vertical transmission via the egg, and is unique to whiteflies. This system provides opportunities to study interactions among symbionts that co-inhabit the same cell in the same host: these can be cooperative or antagonistic, may affect the symbiotic contents over time, and may also affect the host by competing with the primary symbiont for space and resources.}, }
@article {pmid20460159, year = {2010}, author = {Andersen, JC and Wu, J and Gruwell, ME and Gwiazdowski, R and Santana, SE and Feliciano, NM and Morse, GE and Normark, BB}, title = {A phylogenetic analysis of armored scale insects (Hemiptera: Diaspididae), based upon nuclear, mitochondrial, and endosymbiont gene sequences.}, journal = {Molecular phylogenetics and evolution}, volume = {57}, number = {3}, pages = {992-1003}, doi = {10.1016/j.ympev.2010.05.002}, pmid = {20460159}, issn = {1095-9513}, mesh = {Animals ; Bacteroidetes/genetics ; Bayes Theorem ; Cell Nucleus/genetics ; DNA, Mitochondrial/genetics ; Evolution, Molecular ; Hemiptera/*classification/*genetics/microbiology ; Likelihood Functions ; *Phylogeny ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Armored scale insects (Hemiptera: Diaspididae) are among the most invasive insects in the world. They have unusual genetic systems, including diverse types of paternal genome elimination (PGE) and parthenogenesis. Intimate relationships with their host plants and bacterial endosymbionts make them potentially important subjects for the study of co-evolution. Here, we expand upon recent phylogenetic work (Morse and Normark, 2006) by analyzing armored scale and endosymbiont DNA sequences from 125 species of armored scale insect, represented by 253 samples and eight outgroup species. We used fragments of four different gene regions: the nuclear protein-coding gene Elongation Factor 1α (EF1α), the large ribosomal subunit (28S) rDNA, a mitochondrial region spanning parts of cytochrome oxidase I (COI) and cytochrome oxidase II (COII), and the small ribosomal subunit (16S) rDNA from the primary bacterial endosymbiont Uzinura diaspidicola. Maximum likelihood, and Bayesian analyses were performed producing highly congruent topological results. A comparison of two datasets, one with and one without missing data, found that missing data had little effect on topology. Our results broadly corroborate several major features of the existing classification, although we do not find any of the subfamilies, tribes or subtribes to be monophyletic as currently constituted. Using ancestral state reconstruction we estimate that the ancestral armored scale had the late PGE sex system, and it may as well have been pupillarial, though results differed between reconstruction methods. These results highlight the need for a complete revision of this family, and provide the groundwork for future taxonomic work in armored scale insects.}, }
@article {pmid20459320, year = {2010}, author = {Gehringer, MM and Pengelly, JJ and Cuddy, WS and Fieker, C and Forster, PI and Neilan, BA}, title = {Host selection of symbiotic cyanobacteria in 31 species of the Australian cycad genus: Macrozamia (Zamiaceae).}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {23}, number = {6}, pages = {811-822}, doi = {10.1094/MPMI-23-6-0811}, pmid = {20459320}, issn = {0894-0282}, mesh = {Australia ; Cyanobacteria/cytology/genetics/*physiology ; Nitrogen Fixation ; Nostoc ; Phylogeny ; Plant Root Nodulation ; Plant Roots/microbiology ; Species Specificity ; *Symbiosis ; Zamiaceae/*microbiology ; }, abstract = {The nitrogen-fixing cyanobacterium Nostoc is a commonly occurring terrestrial and aquatic cyanobacterium often found in symbiosis with a wide range of plant, algal, and fungal species. We investigated the diversity of cyanobacterial species occurring within the coralloid roots of different Macrozamia cycad species at diverse locations throughout Australia. In all, 74 coralloid root samples were processed and 56 endosymbiotic cyanobacteria were cultured. DNA was isolated from unialgal cultures and a segment of the 16S rRNA gene was amplified and sequenced. Microscopic analysis was performed on representative isolates. Twenty-two cyanobacterial species were identified, comprising mostly Nostoc spp. and a Calothrix sp. No correlation was observed between a cycad species and its resident cyanobiont species. The predominant cyanobacterium isolated from 18 root samples occurred over a diverse range of environmental conditions and within 14 different Macrozamia spp. Phylogenetic analysis indicated that endosymbionts were not restricted to previously described terrestrial species. An isolate clustering with Nostoc PCC7120, an aquatic strain, was identified. This is the first comprehensive study to identify the endosymbionts within a cycad genus using samples obtained from their natural habitats. These results indicate that there is negligible host specialization of cyanobacterial endosymbionts within the cycad genus Macrozamia in the wild.}, }
@article {pmid20459317, year = {2010}, author = {Koch, M and Delmotte, N and Rehrauer, H and Vorholt, JA and Pessi, G and Hennecke, H}, title = {Rhizobial adaptation to hosts, a new facet in the legume root-nodule symbiosis.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {23}, number = {6}, pages = {784-790}, doi = {10.1094/MPMI-23-6-0784}, pmid = {20459317}, issn = {0894-0282}, mesh = {Adaptation, Physiological/genetics/*physiology ; Bacterial Proteins/genetics/*metabolism ; Bradyrhizobium/*metabolism ; Fabaceae/microbiology ; *Gene Expression Profiling ; Gene Expression Regulation, Bacterial/*physiology ; Plant Root Nodulation/physiology ; Species Specificity ; }, abstract = {Rhizobia are able to infect legume roots, elicit root nodules, and live therein as endosymbiotic, nitrogen-fixing bacteroids. Host recognition and specificity are the results of early programming events in bacteria and plants, in which important signal molecules play key roles. Here, we introduce a new aspect of this symbiosis: the adaptive response to hosts. This refers to late events in bacteroids in which specific genes are transcribed and translated that help the endosymbionts to meet the disparate environmental requirements imposed by the hosts in which they live. The host-adaptation concept was elaborated with Bradyrhizobium japonicum and three different legumes (soybean, cowpea, and siratro). Transcriptomes and proteomes in root-nodule bacteroids were analyzed and compared, and genes and proteins were identified which are specifically induced in only one of the three hosts. We focused on those determinants that were congruent in the two data sets of host-specific transcripts and proteins: seven for soybean, five for siratro, and two for cowpea. One gene cluster for a predicted ABC-type transporter, differentially expressed in siratro, was deleted in B. japonicum. The respective mutant had a symbiotic defect on siratro rather than on soybean or cowpea. This result demonstrates the value of the applied approach and corroborates the host-specific adaptation concept.}, }
@article {pmid20457156, year = {2010}, author = {Rossi, MI and Aguiar-Alves, F and Santos, S and Paiva, J and Bendas, A and Fernandes, O and Labarthe, N}, title = {Detection of Wolbachia DNA in blood from dogs infected with Dirofilaria immitis.}, journal = {Experimental parasitology}, volume = {126}, number = {2}, pages = {270-272}, doi = {10.1016/j.exppara.2010.05.002}, pmid = {20457156}, issn = {1090-2449}, mesh = {Animals ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/*blood/chemistry ; Dirofilaria immitis/*microbiology ; Dirofilariasis/blood/*microbiology ; Dog Diseases/blood/*microbiology/parasitology ; Dogs ; Female ; Male ; Microfilariae/growth &amp; development/microbiology ; Polymerase Chain Reaction/methods ; Sensitivity and Specificity ; Symbiosis ; Wolbachia/*genetics/isolation &amp; purification ; }, abstract = {Dirofilaria immitis is the causative agent of heartworm disease in canines and felines, and pulmonary dirofilariasis in man. It harbors a symbiotic intracellular bacterium from the genus Wolbachia that plays an important role in its biology and contributes to the inflammatory pathology of the heartworm. This endosymbiont is sensitive to the tetracycline family of antibiotics prompting its use in the treatment of filariasis. To track Wolbachia during treatment, primers were designed based on the FtsZ gene from Wolbachia. These primers amplify a single PCR product with the expected size from DNA samples derived from various species of worms that harbor Wolbachia (D. immitis, Brugia malayi and Brugia pahangy). The detection limit of Wolbachia DNA in the assay was 80 pg of D. immitis DNA. Furthermore, the primer set successfully amplified the expected PCR product using blood samples from dogs harboring the heartworm and circulating microfilariae.}, }
@article {pmid20456506, year = {2010}, author = {Anbutsu, H and Fukatsu, T}, title = {Evasion, suppression and tolerance of Drosophila innate immunity by a male-killing Spiroplasma endosymbiont.}, journal = {Insect molecular biology}, volume = {19}, number = {4}, pages = {481-488}, doi = {10.1111/j.1365-2583.2010.01008.x}, pmid = {20456506}, issn = {1365-2583}, mesh = {Animals ; Antimicrobial Cationic Peptides/genetics/metabolism ; Drosophila melanogaster/genetics/*immunology/*microbiology ; Gene Expression Regulation ; Immune Evasion/*immunology ; Immune Tolerance/*immunology ; Immunity, Innate/*immunology ; Male ; Shock, Septic/genetics ; Spiroplasma/*immunology ; *Symbiosis ; }, abstract = {How endosymbiotic bacteria cope with host insect immunity is poorly understood. Here we report previously unknown aspects of immunity-mediated interactions between male-killing/non-male-killing spiroplasmas and Drosophila host. The male-killing spiroplasma tended to reduce constitutive expression levels of some antimicrobial peptide genes, while the non-male-killing spiroplasma did not. In mutant flies whose innate immunity is constitutively up-regulated, infection densities of the male-killing spiroplasma were significantly suppressed but managed to increase during the aging of adult flies, indicating that the male-killing spiroplasma is resistant to mounted immune attacks. These findings suggest that not only immune evasion but also immune suppression and tolerance are involved in the establishment and maintenance of the insect-microbe symbiotic association.}, }
@article {pmid20435775, year = {2010}, author = {Hoffman, MT and Arnold, AE}, title = {Diverse bacteria inhabit living hyphae of phylogenetically diverse fungal endophytes.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {12}, pages = {4063-4075}, pmid = {20435775}, issn = {1098-5336}, mesh = {Bacteria/*classification/isolation &amp; purification ; Bacterial Physiological Phenomena ; *Biodiversity ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Fungal/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Fungi/*classification/isolation &amp; purification/physiology ; Genes, rRNA ; Molecular Sequence Data ; Phylogeny ; Plants/*microbiology ; RNA, Bacterial/genetics ; RNA, Fungal/genetics ; RNA, Ribosomal/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Both the establishment and outcomes of plant-fungus symbioses can be influenced by abiotic factors, the interplay of fungal and plant genotypes, and additional microbes associated with fungal mycelia. Recently bacterial endosymbionts were documented in soilborne Glomeromycota and Mucoromycotina and in at least one species each of mycorrhizal Basidiomycota and Ascomycota. Here we show for the first time that phylogenetically diverse endohyphal bacteria occur in living hyphae of diverse foliar endophytes, including representatives of four classes of Ascomycota. We examined 414 isolates of endophytic fungi, isolated from photosynthetic tissues of six species of cupressaceous trees in five biogeographic provinces, for endohyphal bacteria using microscopy and molecular techniques. Viable bacteria were observed within living hyphae of endophytic Pezizomycetes, Dothideomycetes, Eurotiomycetes, and Sordariomycetes from all tree species and biotic regions surveyed. A focus on 29 fungus/bacterium associations revealed that bacterial and fungal phylogenies were incongruent with each other and with taxonomic relationships of host plants. Overall, eight families and 15 distinct genotypes of endohyphal bacteria were recovered; most were members of the Proteobacteria, but a small number of Bacillaceae also were found, including one that appears to occur as an endophyte of plants. Frequent loss of bacteria following subculturing suggests a facultative association. Our study recovered distinct lineages of endohyphal bacteria relative to previous studies, is the first to document their occurrence in foliar endophytes representing four of the most species-rich classes of fungi, and highlights for the first time their diversity and phylogenetic relationships with regard both to the endophytes they inhabit and the plants in which these endophyte-bacterium symbiota occur.}, }
@article {pmid20418442, year = {2010}, author = {Sabree, ZL and Degnan, PH and Moran, NA}, title = {Chromosome stability and gene loss in cockroach endosymbionts.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {12}, pages = {4076-4079}, pmid = {20418442}, issn = {1098-5336}, support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; 2 K12 GM000708/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteroidetes/genetics/*physiology ; *Chromosomal Instability ; *Chromosomes, Bacterial ; Cockroaches/*microbiology ; Evolution, Molecular ; *Gene Deletion ; Phylogeny ; *Symbiosis ; Synteny ; }, abstract = {Insect endosymbiont genomes reflect massive gene loss. Two Blattabacterium genomes display colinearity and similar gene contents, despite high orthologous gene divergence, reflecting over 140 million years of independent evolution in separate cockroach lineages. We speculate that distant homologs may replace the functions of some eliminated genes through broadened substrate specificity.}, }
@article {pmid20415578, year = {2010}, author = {Gottwald, TR}, title = {Current epidemiological understanding of citrus Huanglongbing .}, journal = {Annual review of phytopathology}, volume = {48}, number = {}, pages = {119-139}, doi = {10.1146/annurev-phyto-073009-114418}, pmid = {20415578}, issn = {1545-2107}, mesh = {Animals ; Citrus/*parasitology ; Hemiptera ; Insect Vectors ; Plant Diseases/*parasitology ; Rhizobiaceae/pathogenicity ; }, abstract = {Huanglongbing (HLB) is the most destructive citrus pathosystem worldwide. Previously known primarily from Asia and Africa, it was introduced into the Western Hemisphere in 2004. All infected commercial citrus industries continue to decline owing to inadequate current control methods. HLB increase and regional spatial spread, related to vector populations, are rapid compared with other arboreal pathosystems. Disease dynamics result from multiple simultaneous spatial processes, suggesting that psyllid vector transmission is a continuum from local area to very long distance. Evolutionarily, HLB appears to have originated as an insect endosymbiont that has moved into plants. Lack of exposure of citrus to the pathogen prior to approximately 100 years ago did not provide sufficient time for development of resistance. A prolonged incubation period and regional dispersal make eradication nonviable. Multiple asymptomatic infections per symptomatic tree, incomplete systemic distribution within trees, and prolonged incubation period make detection difficult and greatly complicate disease control.}, }
@article {pmid20413911, year = {2010}, author = {Gayen, P and Maitra, S and Datta, S and Babu, SP}, title = {Evidence for Wolbachia symbiosis in microfilariae of Wuchereria bancrofti from West Bengal, India.}, journal = {Journal of biosciences}, volume = {35}, number = {1}, pages = {73-77}, pmid = {20413911}, issn = {0973-7138}, mesh = {Adolescent ; Adult ; Animals ; Anti-Bacterial Agents/*pharmacology ; Elephantiasis, Filarial/*parasitology ; Female ; Geography ; Humans ; India ; Male ; Microscopy, Electron, Transmission/methods ; Middle Aged ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/metabolism ; *Symbiosis ; Wolbachia/*physiology ; Wuchereria bancrofti/*microbiology/physiology ; }, abstract = {Wolbachia are symbiotic endobacteria that infect the majority of filarial nematodes, including Wuchereria bancrofti, Brugia malayi and Onchocerca volvulus. Recent studies have suggested that Wolbachia are necessary for the reproduction and survival of filarial nematodes and have highlighted the use of antibiotic therapy such as tetracycline/doxycycline as a novel method of treatment for infections caused by these organisms. Before such therapy is conceived and implemented on a large scale, it is necessary to assess the prevalence of the endosymbiont in W. bancrofti from different geographical locations. We present data from molecular and electron microscopic studies to provide evidence for Wolbachia symbiosis in W. bancrofti microfilariae collected from two districts (Bankura and Birbhum) of West Bengal, India.}, }
@article {pmid20409002, year = {2010}, author = {Hayashi, T and Banba, M and Shimoda, Y and Kouchi, H and Hayashi, M and Imaizumi-Anraku, H}, title = {A dominant function of CCaMK in intracellular accommodation of bacterial and fungal endosymbionts.}, journal = {The Plant journal : for cell and molecular biology}, volume = {63}, number = {1}, pages = {141-154}, pmid = {20409002}, issn = {1365-313X}, mesh = {Bacteria/growth &amp; development ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinases/genetics/*metabolism ; Gene Expression Regulation, Plant ; Genetic Complementation Test ; Lotus/*enzymology/genetics/microbiology ; Mutation ; Mycorrhizae/growth &amp; development ; Plant Proteins/genetics/*metabolism ; Plant Root Nodulation/*genetics ; Symbiosis/*genetics ; Transformation, Genetic ; }, abstract = {In legumes, Ca(2+)/calmodulin-dependent protein kinase (CCaMK) is a component of the common symbiosis genes that are required for both root nodule (RN) and arbuscular mycorrhiza (AM) symbioses and is thought to be a decoder of Ca(2+) spiking, one of the earliest cellular responses to microbial signals. A gain-of-function mutation of CCaMK has been shown to induce spontaneous nodulation without rhizobia, but the significance of CCaMK activation in bacterial and/or fungal infection processes is not fully understood. Here we show that a gain-of-function CCaMK(T265D) suppresses loss-of-function mutations of common symbiosis genes required for the generation of Ca(2+) spiking, not only for nodule organogenesis but also for successful infection of rhizobia and AM fungi, demonstrating that the common symbiosis genes upstream of Ca(2+) spiking are required solely to activate CCaMK. In RN symbiosis, however, CCaMK(T265D) induced nodule organogenesis, but not rhizobial infection, on Nod factor receptor (NFRs) mutants. We propose a model of symbiotic signaling in host legume plants, in which CCaMK plays a key role in the coordinated induction of infection thread formation and nodule organogenesis.}, }
@article {pmid20405214, year = {2011}, author = {Johnson, MD}, title = {The acquisition of phototrophy: adaptive strategies of hosting endosymbionts and organelles.}, journal = {Photosynthesis research}, volume = {107}, number = {1}, pages = {117-132}, pmid = {20405214}, issn = {1573-5079}, mesh = {*Adaptation, Physiological ; Autotrophic Processes ; *Biological Evolution ; Ecosystem ; Eukaryota/genetics/metabolism/*physiology ; Models, Biological ; Organelles/genetics/metabolism/*physiology ; Phototrophic Processes/*physiology ; Phylogeny ; Symbiosis/genetics/*physiology ; }, abstract = {Many non-photosynthetic species of protists and metazoans are capable of hosting viable algal endosymbionts or their organelles through adaptations of phagocytic pathways. A form of mixotrophy combining phototrophy and heterotrophy, acquired phototrophy (AcPh) encompasses a suite of endosymbiotic and organelle retention interactions, that range from facultative to obligate. AcPh is a common phenomenon in aquatic ecosystems, with endosymbiotic associations generally more prevalent in nutrient poor environments, and organelle retention typically associated with more productive ones. All AcPhs benefit from enhanced growth due to access to photosynthetic products; however, the degree of metabolic integration and dependency in the host varies widely. AcPh is found in at least four of the major eukaryotic supergroups, and is the driving force in the evolution of secondary and tertiary plastid acquisitions. Mutualistic resource partitioning characterizes most algal endosymbiotic interactions, while organelle retention is a form of predation, characterized by nutrient flow (i.e., growth) in one direction. AcPh involves adaptations to recognize specific prey or endosymbionts and to house organelles or endosymbionts within the endomembrane system but free from digestion. In many cases, hosts depend upon AcPh for the production of essential nutrients, many of which remain obscure. The practice of AcPh has led to multiple independent secondary and tertiary plastid acquisition events among several eukaryote lineages, giving rise to the diverse array of algae found in modern aquatic ecosystems. This article highlights those AcPhs that are model research organisms for both metazoans and protists. Much of the basic biology of AcPhs remains enigmatic, particularly (1) which essential nutrients or factors make certain forms of AcPh obligatory, (2) how hosts regulate and manipulate endosymbionts or sequestered organelles, and (3) what genomic imprint, if any, AcPh leaves on non-photosynthetic host species.}, }
@article {pmid20403728, year = {2010}, author = {Corsaro, D and Pages, GS and Catalan, V and Loret, JF and Greub, G}, title = {Biodiversity of amoebae and amoeba-associated bacteria in water treatment plants.}, journal = {International journal of hygiene and environmental health}, volume = {213}, number = {3}, pages = {158-166}, doi = {10.1016/j.ijheh.2010.03.002}, pmid = {20403728}, issn = {1618-131X}, mesh = {Amoeba/*classification/genetics/isolation &amp; purification/microbiology ; Bacteria/*classification/genetics/isolation &amp; purification ; Biodiversity ; Coculture Techniques ; Genes, Bacterial ; Genes, rRNA ; Metagenome ; Symbiosis ; *Water Microbiology ; Water Purification ; *Water Supply ; }, abstract = {In this study, we enlarged our previous investigation focusing on the biodiversity of chlamydiae and amoebae in a drinking water treatment plant, by the inclusion of two additional plants and by searching also for the presence of legionellae and mycobacteria. Autochthonous amoebae were recovered onto non-nutritive agar, identified by 18S rRNA gene sequencing, and screened for the presence of bacterial endosymbionts. Bacteria were also searched for by Acanthamoeba co-culture. From a total of 125 samples, we recovered 38 amoebae, among which six harboured endosymbionts (three chlamydiae and three legionellae). In addition, we recovered by amoebal co-culture 11 chlamydiae, 36 legionellae (no L. pneumophila), and 24 mycobacteria (all rapid-growers). Two plants presented a similar percentage of samples positive for chlamydiae (11%), mycobacteria (20%) and amoebae (27%), whereas in the third plant the number of recovered bacteria was almost twice higher. Each plant exhibited a relatively high specific microbiota. Amoebae were mainly represented by various Naegleria species, Acanthamoeba species and Hartmannella vermiformis. Parachlamydiaceae were the most abundant chlamydiae (8 strains in total), and in this study we recovered a new genus-level strain, along with new chlamydiae previously reported. Similarly, about 66% of the recovered legionellae and 47% of the isolated mycobacteria could represent new species. Our work highlighted a high species diversity among legionellae and mycobacteria, dominated by putative new species, and it confirmed the presence of chlamydiae in these artificial water systems.}, }
@article {pmid20400564, year = {2010}, author = {Kaiwa, N and Hosokawa, T and Kikuchi, Y and Nikoh, N and Meng, XY and Kimura, N and Ito, M and Fukatsu, T}, title = {Primary gut symbiont and secondary, Sodalis-allied symbiont of the Scutellerid stinkbug Cantao ocellatus.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {11}, pages = {3486-3494}, pmid = {20400564}, issn = {1098-5336}, mesh = {Animals ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gammaproteobacteria/*classification/genetics/*physiology ; Gastrointestinal Tract/microbiology/ultrastructure ; Heteroptera/*microbiology ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Symbiotic associations with midgut bacteria have been commonly found in diverse phytophagous heteropteran groups, where microbiological characterization of the symbiotic bacteria has been restricted to the stinkbug families Acanthosomatidae, Plataspidae, Pentatomidae, Alydidae, and Pyrrhocoridae. Here we investigated the midgut bacterial symbiont of Cantao ocellatus, a stinkbug of the family Scutelleridae. A specific gammaproteobacterium was consistently identified from the insects of different geographic origins. The bacterium was detected in all 116 insects collected from 9 natural host populations. Phylogenetic analyses revealed that the bacterium constitutes a distinct lineage in the Gammaproteobacteria, not closely related to gut symbionts of other stinkbugs. Diagnostic PCR and in situ hybridization demonstrated that the bacterium is extracellularly located in the midgut 4th section with crypts. Electron microscopy of the crypts revealed a peculiar histological configuration at the host-symbiont interface. Egg sterilization experiments confirmed that the bacterium is vertically transmitted to stinkbug nymphs via egg surface contamination. In addition to the gut symbiont, some individuals of C. ocellatus harbored another bacterial symbiont in their gonads, which was closely related to Sodalis glossinidius, the secondary endosymbiont of tsetse flies. Biological aspects of the primary gut symbiont and the secondary Sodalis-allied symbiont are discussed.}, }
@article {pmid20388268, year = {2010}, author = {Zhang, X and Luckhart, S and Tu, Z and Pfeiffer, DG}, title = {Analysis of Wolbachia strains associated with Conotrachelus nenuphar (Coleoptera: Curculionidae) in the Eastern United States.}, journal = {Environmental entomology}, volume = {39}, number = {2}, pages = {396-405}, doi = {10.1603/EN09276}, pmid = {20388268}, issn = {1938-2936}, mesh = {Animals ; Bacterial Outer Membrane Proteins/*genetics ; Female ; Male ; Phylogeny ; Prunus ; Symbiosis ; United States ; Weevils/*microbiology ; Wolbachia/*physiology ; }, abstract = {We studied the distribution patterns of Wolbachia infection associated with plum curculio strains in eight states of the eastern United States. The presence of the Wolbachia-specific gene wsp identified infections of this endosymbiont in 97.8% of the 93 samples tested. Three distinct Wolbachia strains were identified. The strains wCne1 (593 bp) and wCne2 (593 bp) were 97% identical, and their sequences were both 84% identical with wCne3 (590 bp). BLASTN searches through GenBank showed strong similarities between the wsp sequences of the three strains compared with Wolbachia sequenced from other hosts. Degree of similarity with sequences in other Wolbachia strains is discussed. Polymerase chain reaction-restriction fragment length polymorphism was used for superinfection detection. Of 93 samples, 15 (16.1%), 21 (22.6%), 19 (20.4%), and 36 (38.7%) samples were infected by wCne1, wCne2, wCne1 + 2, and wCne3, respectively. Only two (2.2%) samples had no infection. The wCne3 strain was always present as a single infection. Wolbachia strains approximate the distribution of plum curculio strains: northern strain infected with wCne1 and wCne2 strains in supergroup B, and southern strain infected with wCne3 strain in supergroup A, with the mid-Atlantic region as the convergence area. Based on haplotype distribution of plum curculio mitochondrial cytochrome oxidase I, there was a closer relation of the mid-southern plum curculio clade to the far-southern clade than to the northern clade. However, Wolbachia symbionts in mid-southern plum curculio are more closely related to those in northern plum curculio than to those in far-southern plum curculio. The relationship of Wolbachia infection with reproductive incompatibility between plum curculio populations was also discussed.}, }
@article {pmid20388267, year = {2010}, author = {Cheng, RX and Meng, L and Li, BP}, title = {Effects of aposymbiotic and symbiotic aphids on parasitoid progeny development and adult oviposition behavior within aphid instars.}, journal = {Environmental entomology}, volume = {39}, number = {2}, pages = {389-395}, doi = {10.1603/EN08312}, pmid = {20388267}, issn = {1938-2936}, mesh = {Animals ; Aphids/growth &amp; development/microbiology/*parasitology ; Female ; *Host-Parasite Interactions ; Male ; *Oviposition ; Pupa ; *Symbiosis ; Wasps/*growth &amp; development ; }, abstract = {This study aims at exploring the potential relationship between aphidiine parasitoid development and the primary endosymbiont in aphids by focusing on specific aphid instars and the relative effects on parasitoid oviposition behavior and progeny development. Lysiphlebus ambiguus (Aphidiidae, Hymenoptera) is a solitary parasitoid of several species of aphids, including Aphis fabae. In this study, A. fabae was treated with antibiotic rifampicin to obtain aposymbiotic hosts and exposed to parasitism. L. ambiguus launched significantly more attacks on symbiotic L(2) (the second instar), aposymbiotic L(3) (the third instar) and L(4) (the forth instar) hosts than on the corresponding hosts at the same age. L. ambiguus also parasitized more L(1) aphids compared with adults irrespective of whether the aphid was asymbiotic or not. Pupa mortality rate of parasitoid progeny was significantly lower from aposymbiotic hosts than from the corresponding symbiotics at all stages. Female-biased parasitoid progeny was produced from aposymbiotic aphids without respect to host ages, but female progeny increased linearly with host ages at parasitism from symbiotic aphids. Body size of parasitoid progeny increased linearly with host instars at parasitism in symbiotic aphids but did not significantly change across host instars in aposymbiotic aphids. The offspring parasitoids turned out to be generally large in body size from attacking aposymbiotic aphids compared with the symbiotics. Development time of egg-to-adult of parasitoid progeny decreased with host instars in both symbiotic and aposymbiotic aphids but was generally much longer in aposymbiotic aphids than in symbiotic aphids. Our study suggests that age or body size of host aphids may not be the only cue exercised by L. ambiguus to evaluate host quality and that offspring parasitoids may be able to compensate for the nutrition stress associated with disruption of primary endosymbiotc bacteria in aposymbiotic aphids.}, }
@article {pmid20386959, year = {2010}, author = {Hale, MC and Jackson, JR and Dewoody, JA}, title = {Discovery and evaluation of candidate sex-determining genes and xenobiotics in the gonads of lake sturgeon (Acipenser fulvescens).}, journal = {Genetica}, volume = {138}, number = {7}, pages = {745-756}, pmid = {20386959}, issn = {1573-6857}, mesh = {Animals ; DNA, Complementary/chemistry/genetics ; Female ; Fish Proteins/*genetics ; Fishes/*genetics ; Gene Library ; Gene Transfer, Horizontal ; Gonads/*metabolism ; Male ; Sequence Analysis, DNA ; Sex Determination Processes/*genetics ; Sex Differentiation/genetics ; Transcription Factors/genetics ; }, abstract = {Modern pyrosequencing has the potential to uncover many interesting aspects of genome evolution, even in lineages where genomic resources are scarce. In particular, 454 pyrosequencing of nonmodel species has been used to characterize expressed sequence tags, xenobiotics, gene ontologies, and relative levels of gene expression. Herein, we use pyrosequencing to study the evolution of genes expressed in the gonads of a polyploid fish, the lake sturgeon (Acipenser fulvescens). Using 454 pyrosequencing of transcribed genes, we produced more than 125 MB of sequence data from 473,577 high-quality sequencing reads. Sequences that passed stringent quality control thresholds were assembled into 12,791 male contigs and 32,629 female contigs. Average depth of coverage was 4.2 x for the male assembly and 5.5x for the female assembly. Analytical rarefaction indicates that our assemblies include most of the genes expressed in lake sturgeon gonads. Over 86,700 sequencing reads were assigned gene ontologies, many to general housekeeping genes like protein, RNA, and ion binding genes. We searched specifically for sex determining genes and documented significant sex differences in the expression of two genes involved in animal sex determination, DMRT1 and TRA-1. DMRT1 is the master sex determining gene in birds and in medaka (Oryzias latipes) whereas TRA-1 helps direct sexual differentiation in nematodes. We also searched the lake sturgeon assembly for evidence of xenobiotic organisms that may exist as endosymbionts. Our results suggest that exogenous parasites (trematodes) and pathogens (protozoans) apparently have infected lake sturgeon gonads, and the trematodes have horizontally transferred some genes to the lake sturgeon genome.}, }
@article {pmid20380308, year = {2010}, author = {Heise, SR and Elshahed, MS and Little, SE}, title = {Bacterial diversity in Amblyomma americanum (Acari: Ixodidae) with a focus on members of the genus Rickettsia.}, journal = {Journal of medical entomology}, volume = {47}, number = {2}, pages = {258-268}, doi = {10.1603/me09197}, pmid = {20380308}, issn = {0022-2585}, mesh = {Animals ; Ixodidae/*microbiology ; Phylogeny ; RNA, Bacterial/classification/genetics ; RNA, Ribosomal, 16S/classification/genetics ; Rickettsia/*classification/*isolation &amp; purification ; }, abstract = {The lone star tick, Amblyomma americanum (Acari: Ixodidae), is commonly reported from people and animals throughout the eastern U.S. and is associated with transmission of a number of emerging diseases. To better define the microbial communities within lone star ticks, 16S rRNA gene based analysis using bacteria-wide primers, followed by sequencing of individual clones (n = 449) was used to identify the most common bacterial operational taxonomic units (OTUs) present within colony-reared and wild A. americanum. The colony-reared ticks contained primarily sequence affiliated with members of the genus Coxiella (89%; 81/91), common endosymbionts of ticks, and Brevibacterium (11%; 10/91). Similarly, analysis of clones from unfed wild lone star ticks revealed that 96.7% (89/92) of all the OTUs identified were affiliated with Coxiella-like endosymbionts, as compared with only 5.1-11.7% (5/98-9/77) of those identified from wild lone star ticks after feeding. In contrast, the proportion of OTUs identified as Rickettsia sp. in wild-caught ticks increased from 2.2% (2/92) before feeding to as high as 46.8% (36/77) after feeding, and all Rickettsia spp. sequences recovered were most similar to those described from the spotted fever group Rickettsia, specifically R. amblyommii and R. massiliae. Additional characterization of the Rickettsiales tick community by polymerase chain reaction, cloning, and sequencing of 17 kDa and gltA genes confirmed these initial findings and suggested that novel Rickettsia spp. are likely present in these ticks. These data provide insight into the overall, as well as the rickettsial community of wild lone star ticks and may ultimately aid in identification of novel pathogens transmitted by A. americanum.}, }
@article {pmid20380298, year = {2010}, author = {Calvitti, M and Moretti, R and Lampazzi, E and Bellini, R and Dobson, SL}, title = {Characterization of a new Aedes albopictus (Diptera: Culicidae)-Wolbachia pipientis (Rickettsiales: Rickettsiaceae) symbiotic association generated by artificial transfer of the wPip strain from Culex pipiens (Diptera: Culicidae).}, journal = {Journal of medical entomology}, volume = {47}, number = {2}, pages = {179-187}, doi = {10.1603/me09140}, pmid = {20380298}, issn = {0022-2585}, mesh = {Aedes/*microbiology ; Animals ; Culex/*microbiology ; Female ; Longevity ; Male ; Reproduction ; *Symbiosis ; Wolbachia/classification/*physiology ; }, abstract = {Wolbachia is a maternally inherited endosymbiont inducing various effects in insects and other invertebrate hosts that facilitate the invasion of naive host populations. One of the effects is a form of sterility known as cytoplasmic incompatibility (CI) through which females are effectively sterilized when they mate with males harboring a different Wolbachia strain. The repeated mass release of cytoplasmically incompatible males can be a tool to suppress insect populations. Here, we attempt to infect an Aedes albopictus (Skuse) (Diptera: Culicidae) strain, artificially deprived of the natural Wolbachia infection, with a new Wolbachia strain from Culex pipiens (L.) (Diptera: Culicidae). Further experiments were designed to study the effects of the new infection on Ae. albopictus fitness and evaluate key parameters that affect infection dynamics, including CI level and maternal inheritance. Using embryonic microinjection, the new Wolbachia strain was successfully established in Ae. albopictus. Crosses demonstrated a pattern of bidirectional CI between naturally infected and transinfected individuals. Specifically, egg hatch was essentially absent (i.e., CI was very high) in all crosses between the transinfected males and females with a different infection status. Furthermore, naturally infected Ae. albopictus males were incompatible with the transinfected females. Maternal inheritance was close to 100%. Moreover, the new infection did not affect immature and adult survivorship, but it significantly reduced female fecundity and egg hatch rate. The results are discussed in relation to the potential use of the new Ae. albopictus-Wolbachia symbiotic association as a suitable system for the study and development of CI-based strategies for suppressing populations of this important pest and disease vector.}, }
@article {pmid20376101, year = {2010}, author = {Kim, E and Park, JS and Simpson, AG and Matsunaga, S and Watanabe, M and Murakami, A and Sommerfeld, K and Onodera, NT and Archibald, JM}, title = {Complex array of endobionts in Petalomonas sphagnophila, a large heterotrophic euglenid protist from Sphagnum-dominated peatlands.}, journal = {The ISME journal}, volume = {4}, number = {9}, pages = {1108-1120}, doi = {10.1038/ismej.2010.40}, pmid = {20376101}, issn = {1751-7370}, support = {ROP85016//Canadian Institutes of Health Research/Canada ; }, mesh = {Bacteria/*classification/growth &amp; development/*isolation &amp; purification ; Cluster Analysis ; Cytoplasm/microbiology/ultrastructure ; DNA, Bacterial/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Euglenida/cytology/genetics/*microbiology/*physiology ; Microscopy ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Molecular Sequence Data ; Nova Scotia ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; *Soil ; *Soil Microbiology ; *Symbiosis ; }, abstract = {Petalomonas sphagnophila is a poorly studied plastid-lacking euglenid flagellate living in Sphagnum-dominated peatlands. Here we present a broad-ranging microscopic, molecular and microspectrophotometric analysis of uncultured P. sphagnophila collected from four field locations in Nova Scotia, Canada. Consistent with its morphological characteristics, 18S ribosomal DNA (rDNA) phylogenies indicate that P. sphagnophila is specifically related to Petalomonas cantuscygni, the only other Petalomonas species sequenced to date. One of the peculiar characteristics of P. sphagnophila is the presence of several green-pigmented particles approximately 5 mum in diameter in its cytoplasm, which a previously published study suggested to be cyanobacterial endosymbionts. New data presented here, however, suggest that the green intracellular body may not be a cyanobacterium but rather an uncharacterized prokaryote yet to be identified by molecular sequencing. 16S rDNA library sequencing and fluorescence in situ hybridizations show that P. sphagnophila also harbors several other endobionts, including bacteria that represent five novel genus-level groups (one firmicute and four different proteobacteria). 16S rDNA phylogenies suggest that three of these endobionts are related to obligate intracellular bacteria such as Rickettsiales and Coxiella, while the others are related to the Daphnia pathogen Spirobacillus cienkowskii or belong to the Thermoactinomycetaceae. TEM, 16S rDNA library sequencing and a battery of PCR experiments show that the presence of the five P. sphagnophila endobionts varies markedly among the four geographic collections and even among individuals collected from the same location but at different time points. Our study adds significantly to the growing evidence for complex and dynamic protist-bacterial associations in nature.}, }
@article {pmid20371383, year = {2010}, author = {Pochon, X and Gates, RD}, title = {A new Symbiodinium clade (Dinophyceae) from soritid foraminifera in Hawai'i.}, journal = {Molecular phylogenetics and evolution}, volume = {56}, number = {1}, pages = {492-497}, doi = {10.1016/j.ympev.2010.03.040}, pmid = {20371383}, issn = {1095-9513}, mesh = {Animals ; Bayes Theorem ; Cell Nucleus/genetics ; DNA, Chloroplast/genetics ; DNA, Protozoan/genetics ; Dinoflagellida/*classification/*genetics ; *Evolution, Molecular ; Foraminifera ; Gene Library ; Hawaii ; Likelihood Functions ; Models, Genetic ; *Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; }, abstract = {Dinoflagellates in the genus Symbiodinium are crucial components of coral reef ecosystems in their roles as endosymbionts of corals and other marine invertebrates. The genus Symbiodinium encompasses eight lineages (clades A-H), and multiple sub-clade types. Symbiodinium in clades A, B, C, and D are most commonly associated with metazoan hosts while clades C, D, F, G, and H with large soritid foraminifera. Recent studies have described a diversity of new Symbiodinium types within each clades, but no new clades have been reported since 2001. Here, we describe a new clade of Symbiodinium isolated from soritid foraminifera from Hawai'i.}, }
@article {pmid20362581, year = {2010}, author = {Strübing, U and Lucius, R and Hoerauf, A and Pfarr, KM}, title = {Mitochondrial genes for heme-dependent respiratory chain complexes are up-regulated after depletion of Wolbachia from filarial nematodes.}, journal = {International journal for parasitology}, volume = {40}, number = {10}, pages = {1193-1202}, doi = {10.1016/j.ijpara.2010.03.004}, pmid = {20362581}, issn = {1879-0135}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; DNA, Complementary/genetics/metabolism ; Doxycycline/pharmacology ; Electron Transport/genetics/*physiology ; Filarioidea/genetics/*metabolism ; Genes, Mitochondrial/genetics/*physiology ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; Up-Regulation ; Wolbachia/drug effects/*physiology ; }, abstract = {The filarial nematodes Brugia malayi, Wuchereria bancrofti and Onchocerca volvulus cause elephantiasis or dermatitis and blindness resulting in severe morbidity. Annually, 1.3 billion people are at risk of infection. Targeting the essential Wolbachia endobacteria of filarial nematodes with doxycycline has proven to be an effective therapy resulting in a block in embryogenesis, worm development and macrofilaricidal effects. However, doxycycline is contraindicated for a large portion of the at risk population. To identify new targets for anti-wolbachial therapy, understanding the molecular basis of the Wolbachia-filaria symbiosis is required. Using the B. malayi microarray we identified differentially expressed genes in the rodent filaria Litomosoides sigmodontis after depletion of Wolbachia which might have a role in symbiosis. The microarray data were filtered for regulated genes with a false discovery rate <5% and a > or = 2-fold-change. Most of the genes were differentially expressed at day 36 of tetracycline treatment, when 99.8% of Wolbachia were depleted. Several classes of genes were affected, including genes for translation, transcription, folding/sorting of proteins, motility, structure and metabolic and signalling pathways. Quantitative PCR validated 60% of the genes found to be regulated in the microarray. A nuclear encoded heme-binding protein of the globin family was up-regulated upon loss of Wolbachia. Interestingly, mitochondrial encoded subunits of respiratory chain complexes containing heme and riboflavin were also up-regulated. No change in the expression of these genes was seen in tetracycline treated Wolbachia-free Acanthocheilonema viteae. As Wolbachia synthesise heme and filaria do not, we hypothesise that without the endosymbionts no functional heme-containing enzymes can be formed, leading to loss of energy metabolism which then results in up-regulation of the mitochondrial encoded subunits in an attempt to correct the deviation from homeostasis. Our results support targeting the Wolbachia heme synthesis pathway for the discovery of new anti-filarial drugs.}, }
@article {pmid20361505, year = {2010}, author = {Valle, LG}, title = {Description of zygospores in Tectimyces robustus and clarifications on homothallic species within Harpellales.}, journal = {Mycologia}, volume = {102}, number = {2}, pages = {384-391}, doi = {10.3852/09-054}, pmid = {20361505}, issn = {0027-5514}, mesh = {Animals ; Ascomycota/classification/*isolation &amp; purification/ultrastructure ; Insecta/*microbiology ; Spain ; *Water Microbiology ; }, abstract = {Homothallic zygospores of the endosymbiont fungus Tectimyces robustus (Harpellales) are described (and the species is emended) confirming its position within genus Tectimyces, where it was placed originally based on characteristics of the asexual trichospores and thallus. Zygospores in T. robustus are similar to those reported in T. leptophlebiidarum, although fine morphological differences and ontogenic features of sexual spores clearly delineate both species. A morphological comparison of T. robustus zygospores with other homothallic species of Harpellales is provided.}, }
@article {pmid20356892, year = {2010}, author = {Kaiser, W and Huguet, E and Casas, J and Commin, C and Giron, D}, title = {Plant green-island phenotype induced by leaf-miners is mediated by bacterial symbionts.}, journal = {Proceedings. Biological sciences}, volume = {277}, number = {1692}, pages = {2311-2319}, pmid = {20356892}, issn = {1471-2954}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Base Sequence ; Cytokinins/analysis ; DNA, Bacterial/chemistry/genetics ; Female ; Lepidoptera/*microbiology ; Male ; *Malus ; Molecular Sequence Data ; Plant Diseases/*parasitology ; Plant Leaves/*parasitology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/chemistry/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Statistics, Nonparametric ; *Symbiosis ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {The life cycles of many organisms are constrained by the seasonality of resources. This is particularly true for leaf-mining herbivorous insects that use deciduous leaves to fuel growth and reproduction even beyond leaf fall. Our results suggest that an intimate association with bacterial endosymbionts might be their way of coping with nutritional constraints to ensure successful development in an otherwise senescent environment. We show that the phytophagous leaf-mining moth Phyllonorycter blancardella (Lepidoptera) relies on bacterial endosymbionts, most likely Wolbachia, to manipulate the physiology of its host plant resulting in the 'green-island' phenotype--photosynthetically active green patches in otherwise senescent leaves--and to increase its fitness. Curing leaf-miners of their symbiotic partner resulted in the absence of green-island formation on leaves, increased compensatory larval feeding and higher insect mortality. Our results suggest that bacteria impact green-island induction through manipulation of cytokinin levels. This is the first time, to our knowledge, that insect bacterial endosymbionts have been associated with plant physiology.}, }
@article {pmid20347279, year = {2010}, author = {Corsaro, D and Michel, R and Walochnik, J and Müller, KD and Greub, G}, title = {Saccamoeba lacustris, sp. nov. (Amoebozoa: Lobosea: Hartmannellidae), a new lobose amoeba, parasitized by the novel chlamydia 'Candidatus Metachlamydia lacustris' (Chlamydiae: Parachlamydiaceae).}, journal = {European journal of protistology}, volume = {46}, number = {2}, pages = {86-95}, doi = {10.1016/j.ejop.2009.11.002}, pmid = {20347279}, issn = {1618-0429}, mesh = {Acanthamoeba/*classification/*isolation &amp; purification/ultrastructure ; Cluster Analysis ; Comamonadaceae/*classification/*isolation &amp; purification/ultrastructure ; DNA, Bacterial/chemistry/genetics ; DNA, Protozoan/chemistry/genetics ; Lobosea/*classification/*microbiology/ultrastructure ; Microscopy ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; }, abstract = {An amoeba isolated from an aquatic biotope, identified morphologically as Saccamoeba limax, was found harbouring mutualistic rod-shaped gram-negative bacteria. During their cultivation on agar plates, a coinfection also by lysis-inducing chlamydia-like organisms was found in some subpopulations of that amoeba. .Here we provide a molecular-based identification of both the amoeba host and the two bacterial endosymbionts. Analysis of the 18S rRNA gene revealed that this strain is the sister-group to Glaeseria, for which we proposed the name Saccamoeba lacustris. The rod-shaped endosymbiont was identified as a member of Variovorax paradoxus group (Comamonadaceae, Beta-Proteobacteria). No growth on bacteriological agars was recorded, hence this symbiont might be strictly intracellular. The chlamydia-like parasite was unable to infect Acanthamoeba and other amoebae in coculture, showing high host specificity. Phylogenetic analysis based on the 16S rDNA indicated that it is a new member of the family Parachlamydiaceae (order Chlamydiales), for which we proposed the name 'Candidatus Metachlamydia lacustris'.}, }
@article {pmid20345691, year = {2010}, author = {Barshis, DJ and Stillman, JH and Gates, RD and Toonen, RJ and Smith, LW and Birkeland, C}, title = {Protein expression and genetic structure of the coral Porites lobata in an environmentally extreme Samoan back reef: does host genotype limit phenotypic plasticity?.}, journal = {Molecular ecology}, volume = {19}, number = {8}, pages = {1705-1720}, doi = {10.1111/j.1365-294X.2010.04574.x}, pmid = {20345691}, issn = {1365-294X}, mesh = {*Acclimatization/genetics/physiology ; *Adaptation, Physiological/genetics/physiology ; American Samoa ; Animals ; Anthozoa/*genetics/*physiology ; Biomarkers ; Cell Nucleus/genetics ; *Genetics, Population ; Genome, Mitochondrial ; Genotype ; Greenhouse Effect ; Phenotype ; Proteome/genetics ; Sequence Analysis, DNA ; Stress, Physiological ; Symbiosis ; Ubiquitin/genetics ; }, abstract = {The degree to which coral reef ecosystems will be impacted by global climate change depends on regional and local differences in corals' susceptibility and resilience to environmental stressors. Here, we present data from a reciprocal transplant experiment using the common reef building coral Porites lobata between a highly fluctuating back reef environment that reaches stressful daily extremes, and a more stable, neighbouring forereef. Protein biomarker analyses assessing physiological contributions to stress resistance showed evidence for both fixed and environmental influence on biomarker response. Fixed influences were strongest for ubiquitin-conjugated proteins with consistently higher levels found in back reef source colonies both pre and post-transplant when compared with their forereef conspecifics. Additionally, genetic comparisons of back reef and forereef populations revealed significant population structure of both the nuclear ribosomal and mitochondrial genomes of the coral host (F(ST) = 0.146 P < 0.0001, F(ST) = 0.335 P < 0.0001 for rDNA and mtDNA, respectively), whereas algal endosymbiont populations were genetically indistinguishable between the two sites. We propose that the genotype of the coral host may drive limitations to the physiological responses of these corals when faced with new environmental conditions. This result is important in understanding genotypic and environmental interactions in the coral algal symbiosis and how corals may respond to future environmental changes.}, }
@article {pmid20331792, year = {2010}, author = {Rudney, JD and Xie, H and Rhodus, NL and Ondrey, FG and Griffin, TJ}, title = {A metaproteomic analysis of the human salivary microbiota by three-dimensional peptide fractionation and tandem mass spectrometry.}, journal = {Molecular oral microbiology}, volume = {25}, number = {1}, pages = {38-49}, pmid = {20331792}, issn = {2041-1014}, support = {R01 DE017734/DE/NIDCR NIH HHS/United States ; R01 DE017734-03/DE/NIDCR NIH HHS/United States ; 5R01 DE17734/DE/NIDCR NIH HHS/United States ; }, mesh = {Amino Acid Transport Systems ; Bacterial Proteins/*analysis/classification/*genetics/metabolism ; *Bacterial Typing Techniques ; Databases, Protein ; Energy Metabolism ; Glycolysis ; Humans ; Peptides/analysis ; Phylogeny ; Protein Biosynthesis ; Proteome/*analysis/genetics ; Saliva/*microbiology ; Salivary Proteins and Peptides/analysis ; Tandem Mass Spectrometry ; }, abstract = {Metagenomics uses gene expression patterns to understand the taxonomy and metabolic activities of microbial communities. Metaproteomics applies the same approach to community proteomes. Previously, we used a novel three-dimensional peptide separation method to identify over 2000 salivary proteins. This study used those data to carry out the first metaproteomic analysis of the human salivary microbiota. The metagenomic software MEGAN generated a phylogenetic tree, which was checked against the Human Oral Microbiome Database (HOMD). Pathway analyses were performed with the Clusters of Orthologous Groups and MetaCyc databases. Thirty-seven per cent of the peptides were identifiable only at the level of cellular organisms or bacteria. The rest were distributed among five bacterial phyla (61%), archea (0.5%), and viruses (0.8%); 29% were assignable at the genus level, and most belonged to Streptococcus (17%). Eleven per cent of all peptides could be assigned to species. Most taxa were represented in HOMD and they included well-known species such as periodontal pathogens. However, there also were 'exotic' species including aphid endosymbionts; plant, water, and soil bacteria; extremophiles; and archea. The pathway analysis indicated that peptides were linked to translation (37%), followed by glycolysis (19%), amino acid metabolism (8%), and energy production (8%). The taxonomic structure of the salivary metaproteome is very diverse but is dominated by streptococci. 'Exotic' species may actually represent close relatives that have not yet been sequenced. Salivary microbes appear to be actively engaged in protein synthesis, and the pathway analysis is consistent with the metabolism of salivary glycoproteins.}, }
@article {pmid20306206, year = {2010}, author = {Huang, SW and Hsu, BM}, title = {Survey of Naegleria and its resisting bacteria-Legionella in hot spring water of Taiwan using molecular method.}, journal = {Parasitology research}, volume = {106}, number = {6}, pages = {1395-1402}, pmid = {20306206}, issn = {1432-1955}, mesh = {Cluster Analysis ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Protozoan/genetics ; Hot Springs/*microbiology/*parasitology ; Legionella/classification/*isolation &amp; purification ; Naegleria/classification/*isolation &amp; purification ; Phylogeny ; Polymerase Chain Reaction/methods ; Sequence Analysis, DNA ; Taiwan ; }, abstract = {Naegleria is a free-living amoebae existing in soil and aquatic environments. Within the genus Naegleria, N. fowleri is most recognized as potential human pathogen causing primary amoebic meningoencephalitis (PAM). Furthermore, the Naegleria spp. can serve as vehicles for facultative pathogens, such as Legionella. In this study, we identified Naegleria and Legionella based on the PCR amplification with a genus-specific primer pair and investigated the distribution of Naegleria and Legionella at five spring recreation areas in Taiwan. In this study of hot spring and other water sources in Taiwan, five Naegleria spp. were detected in 15 (14.2%) of the water samples. The most frequently detected was N. lovaniensis (n = 6), followed by N. australiensis (n = 5), and then N. clarki (n = 2). N. americana and N. pagei were detected once, respectively. The pathogenic species N. fowleri was not detected; however, N. australiensis considered to be a potential pathogen species in humans was found. Legionella spp., an endosymbiont of Naegleria, was detected in 19 (17.9%) of the water samples in this study. Overall, 5.7% of the water samples contained both Naegleria and Legionella. The Legionella spp. identified were L. pneumophila and L. erythra. Results of this survey confirm the existence of Naegleria and Legionella in Taiwan spring recreation areas. It should be considered a potential threat for health associated with human activities in spring recreation areas of Taiwan.}, }
@article {pmid20300643, year = {2010}, author = {Tomljenovic-Berube, AM and Mulder, DT and Whiteside, MD and Brinkman, FS and Coombes, BK}, title = {Identification of the regulatory logic controlling Salmonella pathoadaptation by the SsrA-SsrB two-component system.}, journal = {PLoS genetics}, volume = {6}, number = {3}, pages = {e1000875}, pmid = {20300643}, issn = {1553-7404}, support = {MOP-82704//Canadian Institutes of Health Research/Canada ; }, mesh = {Adaptation, Physiological/*genetics ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; Chromatin Immunoprecipitation ; Conserved Sequence ; DNA, Bacterial/metabolism ; Evolution, Molecular ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; Genetic Loci/genetics ; Genome, Bacterial/genetics ; Genomic Islands/genetics ; Genomics ; Inverted Repeat Sequences/genetics ; Molecular Sequence Data ; Mutation/genetics ; Oligonucleotide Array Sequence Analysis ; Operon/genetics ; Promoter Regions, Genetic/genetics ; Protein Binding ; RNA, Bacterial/*genetics/metabolism ; Regulon/*genetics ; Salmonella/*genetics ; Transcription Factors/*genetics/metabolism ; }, abstract = {Sequence data from the past decade has laid bare the significance of horizontal gene transfer in creating genetic diversity in the bacterial world. Regulatory evolution, in which non-coding DNA is mutated to create new regulatory nodes, also contributes to this diversity to allow niche adaptation and the evolution of pathogenesis. To survive in the host environment, Salmonella enterica uses a type III secretion system and effector proteins, which are activated by the SsrA-SsrB two-component system in response to the host environment. To better understand the phenomenon of regulatory evolution in S. enterica, we defined the SsrB regulon and asked how this transcription factor interacts with the cis-regulatory region of target genes. Using ChIP-on-chip, cDNA hybridization, and comparative genomics analyses, we describe the SsrB-dependent regulon of ancestral and horizontally acquired genes. Further, we used a genetic screen and computational analyses integrating experimental data from S. enterica and sequence data from an orthologous regulatory system in the insect endosymbiont, Sodalis glossinidius, to identify the conserved yet flexible palindrome sequence that defines DNA recognition by SsrB. Mutational analysis of a representative promoter validated this palindrome as the minimal architecture needed for regulatory input by SsrB. These data provide a high-resolution map of a regulatory network and the underlying logic enabling pathogen adaptation to a host.}, }
@article {pmid20298776, year = {2010}, author = {Chang, X and Wang, Z and Hao, P and Li, YY and Li, YX}, title = {Exploring mitochondrial evolution and metabolism organization principles by comparative analysis of metabolic networks.}, journal = {Genomics}, volume = {95}, number = {6}, pages = {339-344}, doi = {10.1016/j.ygeno.2010.03.006}, pmid = {20298776}, issn = {1089-8646}, mesh = {*Biological Evolution ; Citric Acid Cycle ; Data Collection ; Databases, Factual ; Metabolic Networks and Pathways/*genetics ; Mitochondria/*genetics ; Oxidative Phosphorylation ; Saccharomyces/genetics/metabolism ; Symbiosis/genetics ; Yeasts/genetics/*metabolism ; }, abstract = {The endosymbiotic theory proposed that mitochondrial genomes are derived from an alpha-proteobacterium-like endosymbiont, which was concluded from sequence analysis. We rebuilt the metabolic networks of mitochondria and 22 relative species, and studied the evolution of mitochondrial metabolism at the level of enzyme content and network topology. Our phylogenetic results based on network alignment and motif identification supported the endosymbiotic theory from the point of view of systems biology for the first time. It was found that the mitochondrial metabolic network were much more compact than the relative species, probably related to the higher efficiency of oxidative phosphorylation of the specialized organelle, and the network is highly clustered around the TCA cycle. Moreover, the mitochondrial metabolic network exhibited high functional specificity to the modules. This work provided insight to the understanding of mitochondria evolution, and the organization principle of mitochondrial metabolic network at the network level.}, }
@article {pmid20233171, year = {2010}, author = {Ross, L and Pen, I and Shuker, DM}, title = {Genomic conflict in scale insects: the causes and consequences of bizarre genetic systems.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {85}, number = {4}, pages = {807-828}, doi = {10.1111/j.1469-185X.2010.00127.x}, pmid = {20233171}, issn = {1469-185X}, mesh = {Animals ; *Evolution, Molecular ; Female ; Genes, Insect ; *Genome, Insect ; Hemiptera/*genetics/physiology ; Male ; Models, Genetic ; Ploidies ; Reproduction ; Sex Determination Processes ; Sex Ratio ; }, abstract = {It is now clear that mechanisms of sex determination are extraordinarily labile, with considerable variation across all taxonomic levels. This variation is often expressed through differences in the genetic system (XX-XY, XX-XO, haplodiploidy, and so on). Why there is so much variation in such a seemingly fundamental process has attracted much attention, with recent ideas concentrating on the possible role of genomic conflicts of interest. Here we consider the role of inter- and intra-genomic conflicts in one large insect taxon: the scale insects. Scale insects exhibit a dizzying array of genetic systems, and their biology promotes conflicts of interest over transmission and sex ratio between male- and female-expressed genes, parental- and offspring-expressed genes (both examples of intra-genomic conflict) and between scale insects and their endosymbionts (inter-genomic conflict). We first review the wide range of genetic systems found in scale insects and the possible evolutionary transitions between them. We then outline the theoretical opportunities for genomic conflicts in this group and how these might influence sex determination and sex ratio. We then consider the evidence for these conflicts in the evolution of sex determination in scale insects. Importantly, the evolution of novel genetic systems in scale insects has itself helped create new conflicts of interest, for instance over sex ratio. As a result, a major obstacle to our understanding of the role of conflict in the evolution of sex-determination and genetic systems will be the difficulty in identifying the direction of causal relationships. We conclude by outlining possible experimental and comparative approaches to test more effectively how important genomic conflicts have been.}, }
@article {pmid20232169, year = {2010}, author = {Farkas, JZ and Hinow, P}, title = {Structured and unstructured continuous models for Wolbachia infections.}, journal = {Bulletin of mathematical biology}, volume = {72}, number = {8}, pages = {2067-2088}, doi = {10.1007/s11538-010-9528-1}, pmid = {20232169}, issn = {1522-9602}, mesh = {Animals ; Female ; Gram-Negative Bacterial Infections/*immunology ; Male ; *Models, Immunological ; Symbiosis ; Wolbachia/*immunology ; }, abstract = {We introduce and investigate a series of models for an infection of a diplodiploid host species by the bacterial endosymbiont Wolbachia. The continuous models are characterized by partial vertical transmission, cytoplasmic incompatibility and fitness costs associated with the infection. A particular aspect of interest is competitions between mutually incompatible strains. We further introduce an age-structured model that takes into account different fertility and mortality rates at different stages of the life cycle of the individuals. With only a few parameters, the ordinary differential equation models exhibit already interesting dynamics and can be used to predict criteria under which a strain of bacteria is able to invade a population. Interestingly, but not surprisingly, the age-structured model shows significant differences concerning the existence and stability of equilibrium solutions compared to the unstructured model.}, }
@article {pmid20228207, year = {2011}, author = {Hoque, MS and Broadhurst, LM and Thrall, PH}, title = {Genetic characterization of root-nodule bacteria associated with Acacia salicina and A. stenophylla (Mimosaceae) across south-eastern Australia.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {61}, number = {Pt 2}, pages = {299-309}, doi = {10.1099/ijs.0.021014-0}, pmid = {20228207}, issn = {1466-5034}, mesh = {Acacia/*microbiology ; Australia ; Bacteria/classification/*genetics/isolation &amp; purification ; *Biota ; DNA, Bacterial/genetics ; Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Root Nodules, Plant/*microbiology ; *Soil Microbiology ; Symbiosis ; }, abstract = {Symbiotic relationships between legumes and nitrogen-fixing soil micro-organisms are of ecological importance in plant communities worldwide. For example, nutrient-poor Australian soils are often dominated by shrubby legumes (e.g. species of Acacia). However, relatively few studies have quantified patterns of diversity, host-specificity and effectiveness of these ecologically important plant-microbe interactions. In this study, 16S rRNA gene sequence and PCR-RFLP analyses were used to examine bacterial strains isolated from the root nodules of two widespread south-eastern Australian legumes, Acacia salicina and Acacia stenophylla, across nearly 60 sites. The results showed that there was extensive genetic diversity in microbial populations, including a broad range of novel genomic species. While previous studies have suggested that most native Australian legumes nodulate primarily with species of the genus Bradyrhizobium, our results indicate significant associations with members of other root-nodule-forming bacterial genera, including Rhizobium, Ensifer, Mesorhizobium, Burkholderia, Phyllobacterium and Devosia. Genetic analyses also revealed a diverse suite of non-nodulating bacterial endophytes, only a subset of which have been previously recorded. Although the ecological roles of these endosymbionts are not well understood, they may play both direct and indirect roles in promoting plant growth, nodulation and disease suppression.}, }
@article {pmid20228102, year = {2010}, author = {Rosic, NN and Pernice, M and Dunn, S and Dove, S and Hoegh-Guldberg, O}, title = {Differential regulation by heat stress of novel cytochrome P450 genes from the dinoflagellate symbionts of reef-building corals.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {9}, pages = {2823-2829}, pmid = {20228102}, issn = {1098-5336}, mesh = {Amino Acid Sequence ; Animals ; Anthozoa/*physiology ; Cytochrome P-450 Enzyme System/*genetics ; Dinoflagellida/enzymology/*genetics/physiology ; Gene Expression Regulation ; Genes, Protozoan ; *Hot Temperature ; Molecular Sequence Data ; Symbiosis/genetics ; }, abstract = {Exposure to heat stress has been recognized as one of the major factors leading to the breakdown of the coral-alga symbiosis and coral bleaching. Here, we describe the presence of three new cytochrome P450 (CYP) genes from the reef-building coral endosymbiont Symbiodinium (type C3) and changes in their expression during exposure to severe and moderate heat stress conditions. Sequence analysis of the CYP C-terminal region and two conserved domains, the "PERF" and "heme-binding" domains, confirmed the separate identities of the CYP genes analyzed. In order to explore the effects of different heat stress scenarios, samples of the scleractinian coral Acropora millepora were exposed to elevated temperatures incrementally over an 18-h period (rapid thermal stress) and over a 120-h period (gradual thermal stress). After 18 h of gradual heating and incubation at 26 degrees C, the Symbiodinium CYP mRNA pool was approximately 30% larger, while a further 6 degrees C increase to a temperature above the average sea temperature (29 degrees C after 72 h) resulted in a 2- to 4-fold increase in CYP expression. Both rapid heat stress and gradual heat stress at 32 degrees C resulted in 50% to 90% decreases in CYP gene transcript abundance. Consequently, the initial upregulation of expression of CYP genes at moderately elevated temperatures (26 degrees C and 29 degrees C) was followed by a decrease in expression under the greater thermal stress conditions at 32 degrees C. These findings indicate that in the coral-alga symbiosis under heat stress conditions there is production of chemical stressors and/or transcriptional factors that regulate the expression of genes, such as the genes encoding cytochrome P450 monooxygenases, that are involved in the first line of an organism's chemical defense.}, }
@article {pmid20217845, year = {2010}, author = {Delaye, L and Moya, A}, title = {Evolution of reduced prokaryotic genomes and the minimal cell concept: variations on a theme.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {32}, number = {4}, pages = {281-287}, doi = {10.1002/bies.200900161}, pmid = {20217845}, issn = {1521-1878}, mesh = {Base Composition ; *Biological Evolution ; Cells/*cytology/*metabolism ; Genome/*genetics ; Genomics/methods ; Prokaryotic Cells/*metabolism ; Symbiosis/genetics/physiology ; }, abstract = {Prokaryotic genomes of endosymbionts and parasites are examples of naturally evolved minimal cells, the study of which can shed light on life in its minimum form. Their diverse biology, their lack of a large set of orthologous genes and the existence of essential linage (and environmentally) specific genes all illustrate the diversity of genes building up naturally evolved minimal cells. This conclusion is reinforced by the fact that sometimes the same essential function is performed by genes from different evolutionary origins. Nevertheless, all cells perform a set of life-essential functions however different their cell machinery and environment in which they thrive. An upcoming challenge for biologists will be to discern, by studying differences and similarities in current biodiversity, how cells with reduced genomes have adapted while retaining all basic life-supporting functions.}, }
@article {pmid20217091, year = {2010}, author = {Ahmed, MZ and Ren, SX and Xue, X and Li, XX and Jin, GH and Qiu, BL}, title = {Prevalence of endosymbionts in Bemisia tabaci populations and their in vivo sensitivity to antibiotics.}, journal = {Current microbiology}, volume = {61}, number = {4}, pages = {322-328}, pmid = {20217091}, issn = {1432-0991}, mesh = {Ampicillin/pharmacology ; Animals ; Anti-Bacterial Agents/pharmacology ; China ; DNA, Bacterial/analysis ; Enterobacteriaceae/*drug effects ; Halomonadaceae/*drug effects ; Hemiptera/*microbiology ; Plant Diseases ; Polymerase Chain Reaction ; Rifampin/pharmacology ; *Symbiosis ; Tetracycline/pharmacology ; Wolbachia/*drug effects ; }, abstract = {Bemisia tabaci can harbor both primary and secondary endosymbionts, and the specific endosymbionts can differ among different B. tabaci biotypes. This study determined (1) the prevalence of the primary endosymbiont Portiera aleyrodidarum and secondary endosymbionts Arsenophonus and Wolbachia in two invasive biotypes (B and Q) and one indigenous biotype (Cv) in China and (2) the in vivo effect of three antibiotics (tetracycline, ampicillin trihydrate, and rifampicin) against the endosymbionts; if an antibiotic substantially inhibits an endosymbiont, it could be used to determine the effect of that endosymbiont on B. tabaci. P. aleyrodidarum and Wolbachia were detected in all the three biotypes, while Arsenophonus was found only in the Q and Cv biotypes. P. aleyrodidarum was found in all tested individuals of the three biotypes. Infection rates of Wolbachia in the B, Cv, and Q biotypes were 58, 68, and 48%, respectively. The infection rate of Arsenophonus was 44% in the Q biotype but only 22% in the Cv biotype. The antibiotics failed to eliminate P. aleyrodidarum from any individual of the B, Cv, and Q biotypes but eliminated the secondary endosymbionts, Arsenophonus and Wolbachia, from 50 to 80% of the adult B. tabaci. The effect of the antibiotics depended on the species of endosymbiont, the antibiotic, the B. tabaci biotype, and various interactions between these factors. When used against Arsenophonus, the efficiency of rifampicin was better than ampicillin and tetracycline, regardless of B. tabaci biotype. When inactivating Wolbachia in Cv and Q biotypes, the efficiency tetracycline was better than ampicillin and rifampicin, and while the efficiency of tetracycline was better than rifampicin and ampicillin when they were used against Wolbachia in B biotype.}, }
@article {pmid20215475, year = {2010}, author = {Masters, SL and Walsh, PT}, title = {Release of the mitochondrial endosymbiont helps explain sterile inflammation.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {107}, number = {10}, pages = {E32}, pmid = {20215475}, issn = {1091-6490}, mesh = {Adenosine Triphosphate/metabolism ; Animals ; Inflammation/*immunology ; Interleukin-1beta/immunology/metabolism ; Mice ; Mitochondria/*immunology/metabolism ; Symbiosis ; }, }
@article {pmid20209049, year = {2010}, author = {Maunoury, N and Redondo-Nieto, M and Bourcy, M and Van de Velde, W and Alunni, B and Laporte, P and Durand, P and Agier, N and Marisa, L and Vaubert, D and Delacroix, H and Duc, G and Ratet, P and Aggerbeck, L and Kondorosi, E and Mergaert, P}, title = {Differentiation of symbiotic cells and endosymbionts in Medicago truncatula nodulation are coupled to two transcriptome-switches.}, journal = {PloS one}, volume = {5}, number = {3}, pages = {e9519}, pmid = {20209049}, issn = {1932-6203}, mesh = {Algorithms ; Cell Differentiation ; Expressed Sequence Tags ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; *Gene Expression Regulation, Plant ; Genetic Markers ; Medicago/*metabolism ; Mutation ; Nitrogen/chemistry ; Nitrogen Fixation ; Phenotype ; Ploidies ; Sinorhizobium meliloti/genetics ; Symbiosis/*physiology ; }, abstract = {The legume plant Medicago truncatula establishes a symbiosis with the nitrogen-fixing bacterium Sinorhizobium meliloti which takes place in root nodules. The formation of nodules employs a complex developmental program involving organogenesis, specific cellular differentiation of the host cells and the endosymbiotic bacteria, called bacteroids, as well as the specific activation of a large number of plant genes. By using a collection of plant and bacterial mutants inducing non-functional, Fix(-) nodules, we studied the differentiation processes of the symbiotic partners together with the nodule transcriptome, with the aim of unravelling links between cell differentiation and transcriptome activation. Two waves of transcriptional reprogramming involving the repression and the massive induction of hundreds of genes were observed during wild-type nodule formation. The dominant features of this "nodule-specific transcriptome" were the repression of plant defense-related genes, the transient activation of cell cycle and protein synthesis genes at the early stage of nodule development and the activation of the secretory pathway along with a large number of transmembrane and secretory proteins or peptides throughout organogenesis. The fifteen plant and bacterial mutants that were analyzed fell into four major categories. Members of the first category of mutants formed non-functional nodules although they had differentiated nodule cells and bacteroids. This group passed the two transcriptome switch-points similarly to the wild type. The second category, which formed nodules in which the plant cells were differentiated and infected but the bacteroids did not differentiate, passed the first transcriptome switch but not the second one. Nodules in the third category contained infection threads but were devoid of differentiated symbiotic cells and displayed a root-like transcriptome. Nodules in the fourth category were free of bacteria, devoid of differentiated symbiotic cells and also displayed a root-like transcriptome. A correlation thus exists between the differentiation of symbiotic nodule cells and the first wave of nodule specific gene activation and between differentiation of rhizobia to bacteroids and the second transcriptome wave in nodules. The differentiation of symbiotic cells and of bacteroids may therefore constitute signals for the execution of these transcriptome-switches.}, }
@article {pmid20207755, year = {2010}, author = {Williams, KP and Gillespie, JJ and Sobral, BW and Nordberg, EK and Snyder, EE and Shallom, JM and Dickerman, AW}, title = {Phylogeny of gammaproteobacteria.}, journal = {Journal of bacteriology}, volume = {192}, number = {9}, pages = {2305-2314}, pmid = {20207755}, issn = {1098-5530}, support = {HHSN266200400035C//PHS HHS/United States ; }, mesh = {Bacterial Proteins/genetics ; Computational Biology ; Gammaproteobacteria/*classification/genetics ; Genome, Bacterial/genetics ; *Phylogeny ; RNA, Ribosomal/genetics ; }, abstract = {The phylogeny of the large bacterial class Gammaproteobacteria has been difficult to resolve. Here we apply a telescoping multiprotein approach to the problem for 104 diverse gammaproteobacterial genomes, based on a set of 356 protein families for the whole class and even larger sets for each of four cohesive subregions of the tree. Although the deepest divergences were resistant to full resolution, some surprising patterns were strongly supported. A representative of the Acidithiobacillales routinely appeared among the outgroup members, suggesting that in conflict with rRNA-based phylogenies this order does not belong to Gammaproteobacteria; instead, it (and, independently, "Mariprofundus") diverged after the establishment of the Alphaproteobacteria yet before the betaproteobacteria/gammaproteobacteria split. None of the orders Alteromonadales, Pseudomonadales, or Oceanospirillales were monophyletic; we obtained strong support for clades that contain some but exclude other members of all three orders. Extreme amino acid bias in the highly A+T-rich genome of Candidatus Carsonella prevented its reliable placement within Gammaproteobacteria, and high bias caused artifacts that limited the resolution of the relationships of other insect endosymbionts, which appear to have had multiple origins, although the unbiased genome of the endosymbiont Sodalis acted as an attractor for them. Instability was observed for the root of the Enterobacteriales, with nearly equal subsets of the protein families favoring one or the other of two alternative root positions; the nematode symbiont Photorhabdus was identified as a disruptor whose omission helped stabilize the Enterobacteriales root.}, }
@article {pmid20203610, year = {2010}, author = {Zhang, Q and Raoof, M and Chen, Y and Sumi, Y and Sursal, T and Junger, W and Brohi, K and Itagaki, K and Hauser, CJ}, title = {Circulating mitochondrial DAMPs cause inflammatory responses to injury.}, journal = {Nature}, volume = {464}, number = {7285}, pages = {104-107}, pmid = {20203610}, issn = {1476-4687}, support = {R01 GM051477/GM/NIGMS NIH HHS/United States ; R01 GM059179/GM/NIGMS NIH HHS/United States ; R01 GM059179-08/GM/NIGMS NIH HHS/United States ; R01 GM059179-09/GM/NIGMS NIH HHS/United States ; }, mesh = {Acute Lung Injury/immunology/pathology ; Animals ; Calcium Signaling ; Cells, Cultured ; CpG Islands/immunology ; DNA, Mitochondrial/blood/immunology ; Femur/injuries ; Fractures, Bone/immunology/pathology ; Humans ; Immunity, Innate/immunology ; Liver/immunology/injuries/pathology ; Male ; Mitochondria/*immunology/*metabolism ; Mitogen-Activated Protein Kinases/metabolism ; Muscle, Skeletal/immunology/pathology ; N-Formylmethionine Leucyl-Phenylalanine/immunology/metabolism ; Neutrophils/enzymology/immunology/metabolism ; Phosphorylation ; Rats ; Rats, Sprague-Dawley ; Receptors, Formyl Peptide/metabolism ; Sepsis/immunology/metabolism/microbiology ; Systemic Inflammatory Response Syndrome/blood/*complications/*immunology/pathology ; Toll-Like Receptor 9/metabolism ; Wounds and Injuries/blood/*complications/*immunology/pathology ; }, abstract = {Injury causes a systemic inflammatory response syndrome (SIRS) that is clinically much like sepsis. Microbial pathogen-associated molecular patterns (PAMPs) activate innate immunocytes through pattern recognition receptors. Similarly, cellular injury can release endogenous 'damage'-associated molecular patterns (DAMPs) that activate innate immunity. Mitochondria are evolutionary endosymbionts that were derived from bacteria and so might bear bacterial molecular motifs. Here we show that injury releases mitochondrial DAMPs (MTDs) into the circulation with functionally important immune consequences. MTDs include formyl peptides and mitochondrial DNA. These activate human polymorphonuclear neutrophils (PMNs) through formyl peptide receptor-1 and Toll-like receptor (TLR) 9, respectively. MTDs promote PMN Ca(2+) flux and phosphorylation of mitogen-activated protein (MAP) kinases, thus leading to PMN migration and degranulation in vitro and in vivo. Circulating MTDs can elicit neutrophil-mediated organ injury. Cellular disruption by trauma releases mitochondrial DAMPs with evolutionarily conserved similarities to bacterial PAMPs into the circulation. These signal through innate immune pathways identical to those activated in sepsis to create a sepsis-like state. The release of such mitochondrial 'enemies within' by cellular injury is a key link between trauma, inflammation and SIRS.}, }
@article {pmid20195512, year = {2010}, author = {Grönke, S and Clarke, DF and Broughton, S and Andrews, TD and Partridge, L}, title = {Molecular evolution and functional characterization of Drosophila insulin-like peptides.}, journal = {PLoS genetics}, volume = {6}, number = {2}, pages = {e1000857}, pmid = {20195512}, issn = {1553-7404}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Body Weight/drug effects ; Diet ; Drosophila/drug effects/*genetics/growth &amp; development/microbiology ; Drosophila Proteins/*genetics/*metabolism ; Drug Resistance/drug effects ; Energy Metabolism/drug effects/genetics ; *Evolution, Molecular ; Fertility/drug effects ; Gene Expression Regulation, Developmental/drug effects ; Genetic Loci/genetics ; Longevity/drug effects ; Mutation/genetics ; Ovum/cytology/drug effects ; Phylogeny ; Stress, Physiological/drug effects/genetics ; Survival Analysis ; Time Factors ; Wolbachia/metabolism ; Xenobiotics/pharmacology ; }, abstract = {Multicellular animals match costly activities, such as growth and reproduction, to the environment through nutrient-sensing pathways. The insulin/IGF signaling (IIS) pathway plays key roles in growth, metabolism, stress resistance, reproduction, and longevity in diverse organisms including mammals. Invertebrate genomes often contain multiple genes encoding insulin-like ligands, including seven Drosophila insulin-like peptides (DILPs). We investigated the evolution, diversification, redundancy, and functions of the DILPs, combining evolutionary analysis, based on the completed genome sequences of 12 Drosophila species, and functional analysis, based on newly-generated knock-out mutations for all 7 dilp genes in D. melanogaster. Diversification of the 7 DILPs preceded diversification of Drosophila species, with stable gene diversification and family membership, suggesting stabilising selection for gene function. Gene knock-outs demonstrated both synergy and compensation of expression between different DILPs, notably with DILP3 required for normal expression of DILPs 2 and 5 in brain neurosecretory cells and expression of DILP6 in the fat body compensating for loss of brain DILPs. Loss of DILP2 increased lifespan and loss of DILP6 reduced growth, while loss of DILP7 did not affect fertility, contrary to its proposed role as a Drosophila relaxin. Importantly, loss of DILPs produced in the brain greatly extended lifespan but only in the presence of the endosymbiontic bacterium Wolbachia, demonstrating a specific interaction between IIS and Wolbachia in lifespan regulation. Furthermore, loss of brain DILPs blocked the responses of lifespan and fecundity to dietary restriction (DR) and the DR response of these mutants suggests that IIS extends lifespan through mechanisms that both overlap with those of DR and through additional mechanisms that are independent of those at work in DR. Evolutionary conservation has thus been accompanied by synergy, redundancy, and functional differentiation between DILPs, and these features may themselves be of evolutionary advantage.}, }
@article {pmid20194926, year = {2010}, author = {Liu, D and Gong, Q and Ma, Y and Li, P and Li, J and Yang, S and Yuan, L and Yu, Y and Pan, D and Xu, F and Wang, NN}, title = {cpSecA, a thylakoid protein translocase subunit, is essential for photosynthetic development in Arabidopsis.}, journal = {Journal of experimental botany}, volume = {61}, number = {6}, pages = {1655-1669}, doi = {10.1093/jxb/erq033}, pmid = {20194926}, issn = {1460-2431}, mesh = {Arabidopsis/genetics/*metabolism/*physiology/ultrastructure ; Arabidopsis Proteins/genetics/*metabolism ; Chloroplast Proteins ; Electrophoresis, Polyacrylamide Gel ; Gene Expression Regulation, Plant/genetics/physiology ; Membrane Proteins/genetics/*metabolism ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Oligonucleotide Array Sequence Analysis ; Oxidative Stress/genetics/physiology ; Plant Proteins/genetics/*metabolism ; Plants, Genetically Modified/genetics/metabolism/physiology/ultrastructure ; Protein Subunits/genetics/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Thylakoids/*enzymology/ultrastructure ; }, abstract = {The endosymbiont-derived Sec-dependent protein sorting pathway is essential for protein import into the thylakoid lumen and is important for the proper functioning of the chloroplast. Two loss-of-function mutants of cpSecA, the ATPase subunit of the chloroplast Sec translocation machinery, were analysed in Arabidopsis. The homozygous mutants were albino and seedling lethal under autotrophic conditions and remained dwarf and infertile with an exogenous carbon supply. They were subject to oxidative stress and accumulated superoxide under normal lighting conditions. Electron microscopy revealed that the chloroplast of the mutants had underdeveloped thylakoid structures. Histochemical GUS assay of the AtcpSecA::GUS transgenic plants confirmed that AtcpSecA was expressed in green organs in a light-inducible way. Real-time RT-PCR and microarray analysis revealed repressed transcription of nucleus- and chloroplast- encoded subunits of photosynthetic complexes, and induced transcription of chloroplast protein translocation machinery and mitochondrion-encoded respiratory complexes in the mutants. It is inferred that AtcpSecA plays an essential role in chloroplast biogenesis, the absence of which triggered a retrograde signal, eventually leading to a reprogramming of chloroplast and mitochondrial gene expression.}, }
@article {pmid20153447, year = {2010}, author = {Ingram, BO and Sohlenkamp, C and Geiger, O and Raetz, CR}, title = {Altered lipid A structures and polymyxin hypersensitivity of Rhizobium etli mutants lacking the LpxE and LpxF phosphatases.}, journal = {Biochimica et biophysica acta}, volume = {1801}, number = {5}, pages = {593-604}, pmid = {20153447}, issn = {0006-3002}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; U54 GM069338/GM/NIGMS NIH HHS/United States ; R37 GM051796-14/GM/NIGMS NIH HHS/United States ; R01 GM051796/GM/NIGMS NIH HHS/United States ; GM-51796/GM/NIGMS NIH HHS/United States ; GM-069338/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; *Bacterial Proteins/genetics/metabolism ; Humans ; Lipid A/*chemistry/metabolism ; Microbial Sensitivity Tests ; Molecular Structure ; Mutation ; Nitrogen Fixation/physiology ; Phaseolus/microbiology ; *Phosphoric Monoester Hydrolases/genetics/metabolism ; Polymyxins/*pharmacology ; *Rhizobium etli/chemistry/drug effects/genetics ; Spectrometry, Mass, Electrospray Ionization ; Symbiosis ; }, abstract = {The lipid A of Rhizobium etli, a nitrogen-fixing plant endosymbiont, displays significant structural differences when compared to that of Escherichia coli. An especially striking feature of R. etli lipid A is that it lacks both the 1- and 4'-phosphate groups. The 4'-phosphate moiety of the distal glucosamine unit is replaced with a galacturonic acid residue. The dephosphorylated proximal unit is present as a mixture of the glucosamine hemiacetal and an oxidized 2-aminogluconate derivative. Distinct lipid A phosphatases directed to the 1 or the 4'-positions have been identified previously in extracts of R. etli and Rhizobium leguminosarum. The corresponding structural genes, lpxE and lpxF, respectively, have also been identified. Here, we describe the isolation and characterization of R. etli deletion mutants in each of these phosphatase genes and the construction of a double phosphatase mutant. Mass spectrometry confirmed that the mutant strains completely lacked the wild-type lipid A species and accumulated the expected phosphate-containing derivatives. Moreover, radiochemical analysis revealed that phosphatase activity was absent in membranes prepared from the mutants. Our results indicate that LpxE and LpxF are solely responsible for selectively dephosphorylating the lipid A molecules of R. etli. All the mutant strains showed an increased sensitivity to polymyxin relative to the wild-type. However, despite the presence of altered lipid A species containing one or both phosphate groups, all the phosphatase mutants formed nitrogen-fixing nodules on Phaseolus vulgaris. Therefore, the dephosphorylation of lipid A molecules in R. etli is not required for nodulation but may instead play a role in protecting the bacteria from cationic antimicrobial peptides or other immune responses of plants.}, }
@article {pmid20149223, year = {2010}, author = {Majerus, TM and Majerus, ME}, title = {Discovery and identification of a male-killing agent in the Japanese ladybird Propylea japonica (Coleoptera: Coccinellidae).}, journal = {BMC evolutionary biology}, volume = {10}, number = {}, pages = {37}, pmid = {20149223}, issn = {1471-2148}, mesh = {Animals ; Coleoptera/*microbiology/*physiology ; DNA, Bacterial/genetics ; Female ; Male ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/drug effects/genetics/*physiology ; Sex Characteristics ; Sex Ratio ; Tetracycline/pharmacology ; }, abstract = {BACKGROUND: Endosymbionts that manipulate the reproduction of their hosts have been reported widely in invertebrates. One such group of endosymbionts is the male-killers. To date all male-killers reported are bacterial in nature, but comprise a diverse group. Ladybirds have been described as a model system for the study of male-killing, which has been reported in multiple species from widespread geographic locations. Whilst criteria of low egg hatch-rate and female-biased progenic sex ratio have been used to identify female hosts of male-killers, variation in vertical transmission efficiency and host genetic factors may result in variation in these phenotypic indicators of male-killer presence. Molecular identification of bacteria and screening for bacterial presence provide us with a more accurate method than breeding data alone to link the presence of the bacteria to the male-killing phenotype. In addition, by identifying the bacteria responsible we may find evidence for horizontal transfer between endosymbiont hosts and can gain insight into the evolutionary origins of male-killing. Phylogenetic placement of male-killing bacteria will allow us to address the question of whether male-killing is a potential strategy for only some, or all, maternally inherited bacteria. Together, phenotypic and molecular characterisation of male-killers will allow a deeper insight into the interactions between host and endosymbiont, which ultimately may lead to an understanding of how male-killers identify and kill male-hosts.<br><br>RESULTS: A male-killer was detected in the Japanese coccinellid, Propylea japonica (Thunberg) a species not previously known to harbour male-killers. Families produced by female P. japonica showed significantly female-biased sex ratios. One female produced only daughters. This male-killer trait was maternally inherited and antibiotic treatment produced a full, heritable cure. Molecular analysis identified Rickettsia to be associated with the trait in this species of ladybird.<br><br>CONCLUSION: We conclude that P. japonica is host to a bacterial male-killer that is vertically inherited with variable transmission efficiency. Rickettsia presence correlates with the male-killing trait, but there is some variation in the phenotypic expression of the trait due to interaction with host factors. Phylogenetic analysis using the 16S rRNA and 17 kDa antigen genes suggests there may have been horizontal transfer of Rickettsial male-killers between different ladybird hosts.}, }
@article {pmid20147035, year = {2009}, author = {Werren, JH and Loehlin, DW}, title = {The parasitoid wasp Nasonia: an emerging model system with haploid male genetics.}, journal = {Cold Spring Harbor protocols}, volume = {2009}, number = {10}, pages = {pdb.emo134}, pmid = {20147035}, issn = {1559-6095}, support = {R24 GM084917/GM/NIGMS NIH HHS/United States ; R24 GM084917-02/GM/NIGMS NIH HHS/United States ; 1 R24 GM084917-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Diploidy ; Female ; Genome ; Genomics ; *Haploidy ; Insecta ; Male ; Microsatellite Repeats ; Models, Genetic ; Polymorphism, Single Nucleotide ; Quantitative Trait Loci ; Sexual Behavior, Animal ; Wasps/*genetics/*physiology ; }, abstract = {Nasonia is a complex of four closely related species of wasps that is rapidly emerging as a model for evolutionary and developmental genetics. It has several features that make it an excellent genetic system, including a short generation time, ease of rearing, interfertile species, visible and molecular markers, and a sequenced genome. The form of sex determination, called "haplodiploidy," makes Nasonia particularly suitable as a genetic tool. Females are diploid and develop from fertilized eggs, whereas males are haploid and develop from unfertilized eggs. This allows geneticists to exploit many of the advantages of haploid genetics in an otherwise complex eukaryotic organism. Nasonia readily inbreeds, permitting production of isogenic lines, and the four species in the genus are interfertile (after removal of the endosymbiont Wolbachia), facilitating movement of genes between the species for efficient positional cloning of quantitative trait loci (QTL). Genome sequencing of the genetic model Nasonia vitripennis and two interfertile species, Nasonia giraulti and Nasonia longicornis, is now completed. This genome project provides a wealth of interspecies polymorphisms (e.g., single nucleotide polymorphisms [SNPs], insertion-deletions [indels], microsatellites) to facilitate positional cloning of genes involved in species differences in behavior, morphology, and development. Advances in the genetics of this system also open a path for improvement of parasitoid insects as agents of pest control.}, }
@article {pmid20146936, year = {2010}, author = {Narayanan, N and Krishnakumar, B and Manilal, VB}, title = {Oxygen tolerance and occurrence of superoxide dismutase as an antioxidant enzyme in Metopus es.}, journal = {Research in microbiology}, volume = {161}, number = {3}, pages = {227-233}, doi = {10.1016/j.resmic.2010.01.009}, pmid = {20146936}, issn = {1769-7123}, mesh = {Animals ; Antioxidants/metabolism ; Ciliophora/*drug effects/*enzymology ; Oxidative Stress ; Oxygen/metabolism/*toxicity ; Superoxide Dismutase/*metabolism ; Survival Analysis ; }, abstract = {The free-living anaerobic ciliate Metopus es was found to possess moderate tolerance to oxygen. Direct oxygen exposure led to the death of >80% of the population within 24h, but the remaining cells exhibited some oxygen tolerance and survived up to 4 days without any growth. Survival of the ciliate was observed only in an oxygen tension up to 7.0microM, and higher O(2) concentrations (>7.0microM) were found to be detrimental with a K(m) value of 3.5microM. The percentage of survival (50%) was higher when the culture was exposed to a low oxygen level (1.3microM) and it decreased with increasing oxygen tension. No catalase activity was detected in the extract of surviving ciliates. Maximum superoxide dismutase (SOD) activity of 1.52+/-0.4U/mg protein was observed at 1.3microM oxygen. SOD activity was not affected by cyanide or hydrogen peroxide, indicating that it belongs to the Mn type of SOD. Methanogenic endosymbionts in M. es lost their autofluorescence on oxygen exposure of >5.0microM, but their viability was not permanently affected, as indicated by the maintenance of a similar number of methanogens/cell upon restoring the anaerobic condition.}, }
@article {pmid20143351, year = {2010}, author = {Kutovaya, OA and McKay, RM and Bullerjahn, GS}, title = {Expression of hcp in freshwater Synechococcus spp., a gene encoding a hyperconserved protein in picocyanobacteria.}, journal = {Journal of basic microbiology}, volume = {50}, number = {3}, pages = {227-231}, doi = {10.1002/jobm.200900337}, pmid = {20143351}, issn = {1521-4028}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*biosynthesis/*genetics ; Conserved Sequence ; DNA, Bacterial/chemistry/genetics ; Evolution, Molecular ; Fresh Water/*microbiology ; *Gene Expression ; Molecular Sequence Data ; RNA, Transfer/genetics ; Ribosomal Proteins/biosynthesis/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Synechococcus/*genetics/isolation &amp; purification ; Synteny ; }, abstract = {Marine picoplankton of the genus Synechococcus and Prochlorococcus spp. are widely studied members of the picocyanobacterial clade, composed of unicellular cyanobacteria that dominate pelagic regions of the ocean. Less studied are the related freshwater Synechococcus spp. that similarly dominate the euphotic zone of oligotrophic lakes. Previous work has shown that marine picocyanobacteria harbor a small gene, hcp, that encodes a 62 amino acid protein 100% conserved among all strains examined. The gene is restricted exclusively to the picocyanobacterial lineage. The current study reveals that hcp is also 100% conserved in four freshwater Synechococcus spp. strains isolated from the Laurentian Great Lakes, and that the gene constitutively expressed with genes encoding a ribosomal protein and two tRNA genes. The synteny of the hcp region is also conserved between the marine and freshwater strains. Last, the hcp gene and the organization of the surrounding genetic region has been retained in the reduced genome of a picocyanobacterial endosymbiont of the amoeba Paulinella sp.}, }
@article {pmid20139320, year = {2010}, author = {Kjeldsen, KU and Obst, M and Nakano, H and Funch, P and Schramm, A}, title = {Two types of endosymbiotic bacteria in the enigmatic marine worm Xenoturbella bocki.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {8}, pages = {2657-2662}, pmid = {20139320}, issn = {1098-5336}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Chlamydia/*classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gammaproteobacteria/*classification/genetics/*isolation &amp; purification ; Invertebrates/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Two types of endosymbiotic bacteria were identified in the gastrodermis of the marine invertebrate Xenoturbella bocki (Xenoturbellida, Bilateria). While previously described Chlamydia-like endosymbionts were rare, Gammaproteobacteria distantly related to other endosymbionts and pathogens were abundant. The endosymbionts should be considered when interpreting the poorly understood ecology and evolution of Xenoturbella.}, }
@article {pmid20135225, year = {2010}, author = {Velázquez, E and Valverde, A and Rivas, R and Gomis, V and Peix, A and Gantois, I and Igual, JM and León-Barrios, M and Willems, A and Mateos, PF and Martínez-Molina, E}, title = {Strains nodulating Lupinus albus on different continents belong to several new chromosomal and symbiotic lineages within Bradyrhizobium.}, journal = {Antonie van Leeuwenhoek}, volume = {97}, number = {4}, pages = {363-376}, doi = {10.1007/s10482-010-9415-7}, pmid = {20135225}, issn = {1572-9699}, mesh = {Bacterial Proteins/genetics ; Bradyrhizobium/*classification/genetics/*physiology ; Chile ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; DNA, Ribosomal Spacer ; Lupinus/*microbiology/*physiology ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases/genetics ; Phylogeny ; *Plant Root Nodulation ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; Spain ; *Symbiosis ; }, abstract = {In this work we analysed different chromosomal and symbiotic markers in rhizobial strains nodulating Lupinus albus (white lupin) in several continents. Collectively the analysis of their rrs and atpD genes, and 16S-23S intergenic spacers (ITS), showed that they belong to at least four chromosomal lineages within the genus Bradyrhizobium. Most isolates from the Canary Islands (near to the African continent) grouped with some strains isolated on mainland Spain and were identified as Bradyrhizobium canariense. These strains are divided into two ITS subgroups coincident with those previously described from isolates nodulating Ornithopus. The remaining strains isolated on mainland Spain grouped with most isolates from Chile (American continent) forming a new lineage related to Bradyrhizobium japonicum. The strains BLUT2 and ISLU207 isolated from the Canary Islands and Chile, respectively, formed two new lineages phylogenetically close to different species of Bradyrhizobium depending on the marker analyzed. The analysis of the nodC gene showed that all strains nodulating L. albus belong to the biovar genistearum; nevertheless they form four different nodC lineages of which lineage C is at present exclusively formed by L. albus endosymbionts isolated from different continents.}, }
@article {pmid20126457, year = {2010}, author = {Baldridge, GD and Burkhardt, NY and Oliva, AS and Kurtti, TJ and Munderloh, UG}, title = {Rickettsial ompB promoter regulated expression of GFPuv in transformed Rickettsia montanensis.}, journal = {PloS one}, volume = {5}, number = {1}, pages = {e8965}, pmid = {20126457}, issn = {1932-6203}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI081690/AI/NIAID NIH HHS/United States ; R01 AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Bacterial Outer Membrane Proteins/*genetics ; Base Sequence ; Chloramphenicol O-Acetyltransferase/genetics ; DNA Primers ; DNA Transposable Elements ; Green Fluorescent Proteins/genetics ; *Promoter Regions, Genetic ; RNA, Messenger/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rickettsia/*genetics ; }, abstract = {BACKGROUND: Rickettsia spp. (Rickettsiales: Rickettsiaceae) are Gram-negative, obligate intracellular, alpha-proteobacteria that have historically been associated with blood-feeding arthropods. Certain species cause typhus and spotted fevers in humans, but others are of uncertain pathogenicity or may be strict arthropod endosymbionts. Genetic manipulation of rickettsiae should facilitate a better understanding of their interactions with hosts.<br><br>We transformed a species never associated with human disease, Rickettsia montanensis, by electroporation with a TN5 transposon (pMOD700) containing green fluorescent protein (GFPuv) and chloramphenicol acetyltransferase (CAT) genes under regulation of promoters cloned from the Rickettsia rickettsii ompB gene, and isolated a Chloramphenicol-resistant GFP-fluorescent rickettsiae population (Rmontanensis700). The Rmontanensis700 rickettsiae contained a single transposon integrated near an acetyl-CoA acetyltransferase gene in the rickettsial chromosome. Northern blots showed that GFPuv and CAT mRNAs were both expressed as two transcripts of larger and smaller than predicted length. Western immunoblots showed that Rmontanensis700 and E. coli transformed with a plasmid containing the pMOD700 transposon both expressed GFPuv proteins of the predicted molecular weight.<br><br>CONCLUSIONS/SIGNIFICANCE: Long-standing barriers to transformation of rickettsiae have been overcome by development of transposon-based rickettsial transformation vectors. The ompB promoter may be the most problematic of the four promoters so far employed in those vectors.}, }
@article {pmid20124349, year = {2010}, author = {Martin, W}, title = {Evolutionary origins of metabolic compartmentalization in eukaryotes.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {365}, number = {1541}, pages = {847-855}, pmid = {20124349}, issn = {1471-2970}, mesh = {*Biological Evolution ; Chloroplasts/genetics/metabolism ; Eukaryota/*genetics/*metabolism ; Gene Transfer, Horizontal ; Mitochondria/genetics/metabolism ; Models, Biological ; Organelles/genetics/*metabolism ; Protein Transport ; Symbiosis ; }, abstract = {Many genes in eukaryotes are acquisitions from the free-living antecedents of chloroplasts and mitochondria. But there is no evolutionary 'homing device' that automatically directs the protein product of a transferred gene back to the organelle of its provenance. Instead, the products of genes acquired from endosymbionts can explore all targeting possibilities within the cell. They often replace pre-existing host genes, or even whole pathways. But the transfer of an enzymatic pathway from one compartment to another poses severe problems: over evolutionary time, the enzymes of the pathway acquire their targeting signals for the new compartment individually, not in unison. Until the whole pathway is established in the new compartment, newly routed individual enzymes are useless, and their genes will be lost through mutation. Here it is suggested that pathways attain novel compartmentation variants via a 'minor mistargeting' mechanism. If protein targeting in eukaryotic cells possesses enough imperfection such that small amounts of entire pathways continuously enter novel compartments, selectable units of biochemical function would exist in new compartments, and the genes could become selected. Dual-targeting of proteins is indeed very common within eukaryotic cells, suggesting that targeting variation required for this minor mistargeting mechanism to operate exists in nature.}, }
@article {pmid20124339, year = {2010}, author = {Nowack, EC and Melkonian, M}, title = {Endosymbiotic associations within protists.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {365}, number = {1541}, pages = {699-712}, pmid = {20124339}, issn = {1471-2970}, mesh = {Animals ; *Biological Evolution ; Eukaryota/genetics/physiology ; Mitochondria/genetics/physiology ; Models, Biological ; Nitrogen Fixation ; Photosynthesis ; Plastids/genetics/physiology ; Prokaryotic Cells/microbiology/physiology ; *Symbiosis/genetics/physiology ; }, abstract = {The establishment of an endosymbiotic relationship typically seems to be driven through complementation of the host's limited metabolic capabilities by the biochemical versatility of the endosymbiont. The most significant examples of endosymbiosis are represented by the endosymbiotic acquisition of plastids and mitochondria, introducing photosynthesis and respiration to eukaryotes. However, there are numerous other endosymbioses that evolved more recently and repeatedly across the tree of life. Recent advances in genome sequencing technology have led to a better understanding of the physiological basis of many endosymbiotic associations. This review focuses on endosymbionts in protists (unicellular eukaryotes). Selected examples illustrate the incorporation of various new biochemical functions, such as photosynthesis, nitrogen fixation and recycling, and methanogenesis, into protist hosts by prokaryotic endosymbionts. Furthermore, photosynthetic eukaryotic endosymbionts display a great diversity of modes of integration into different protist hosts. In conclusion, endosymbiosis seems to represent a general evolutionary strategy of protists to acquire novel biochemical functions and is thus an important source of genetic innovation.}, }
@article {pmid20103843, year = {2009}, author = {Hsu, SC and Inoue, K}, title = {Two evolutionarily conserved essential beta-barrel proteins in the chloroplast outer envelope membrane.}, journal = {Bioscience trends}, volume = {3}, number = {5}, pages = {168-178}, pmid = {20103843}, issn = {1881-7823}, mesh = {Chloroplasts/*metabolism ; *Evolution, Molecular ; Gene Duplication ; Membrane Proteins/chemistry/genetics/*metabolism ; Plant Proteins/chemistry/genetics/*metabolism ; Protein Conformation ; }, abstract = {Chloroplasts are organelles specific to photosynthetic eukaryotes that support the lives of most organisms on earth. Chloroplasts were derived from an ancient cyanobacterium by endosymbiosis, and one characteristic shared between them and extant cyanobacteria is the presence of beta-barrel proteins in the outer membrane. These integral membrane proteins are also found in the outer membranes of proteobacteria and mitochondria. In particular, a group of homologous beta-barrel proteins called BamA homologs are present in all Gram-negative bacteria and the endosymbiotic organelles, i.e., chloroplasts and mitochondria. It was recently revealed that, in both proteobacteria and mitochondria, there is a single essential BamA homolog that mediates beta-barrel protein assembly. In a chloroplast, there are two distinct BamA homologs, Toc75 and OEP80, which diverged early in the evolution of chloroplasts from their common ancestor with extant cyanobacteria. Recent genetic studies demonstrated that each of these proteins is indispensable for viability of plants although neither has been shown to be involved in beta-barrel protein assembly. Toc75 catalyzes import of nuclear-encoded precursor proteins, a process that is not required for bacteria, whereas the molecular function of OEP80 remains elusive. Establishment of a protein import apparatus was required to facilitate the transfer of genes from the endosymbiont to the host cell nucleus. Hence, we propose that the gene duplication giving rise to the two essential BamA homologs was a prerequisite for the successful conversion of the cyanobacterial endosymbiont into the chloroplast. Consequently, continued study of these two chloroplast proteins should advance our understanding of endosymbiosis and evolutionarily conserved proteins in general.}, }
@article {pmid20100523, year = {2010}, author = {van der Laan, M and Hutu, DP and Rehling, P}, title = {On the mechanism of preprotein import by the mitochondrial presequence translocase.}, journal = {Biochimica et biophysica acta}, volume = {1803}, number = {6}, pages = {732-739}, doi = {10.1016/j.bbamcr.2010.01.013}, pmid = {20100523}, issn = {0006-3002}, mesh = {Adenosine Triphosphate/metabolism ; Carrier Proteins/metabolism ; Cell Membrane/metabolism ; HSP70 Heat-Shock Proteins/metabolism ; Intracellular Membranes/metabolism ; Membrane Potentials ; Membrane Transport Proteins/metabolism ; Mitochondria/*enzymology/metabolism ; Mitochondrial Precursor Protein Import Complex Proteins ; Models, Biological ; *Protein Transport ; Saccharomyces cerevisiae/metabolism ; Saccharomyces cerevisiae Proteins/metabolism ; Signal Transduction ; }, abstract = {Mitochondria are organelles of endosymbiontic origin that contain more than one thousand different proteins. The vast majority of these proteins is synthesized in the cytosol and imported into one of four mitochondrial subcompartments: outer membrane, intermembrane space, inner membrane and matrix. Several import pathways exist and are committed to different classes of precursor proteins. The presequence translocase of the inner mitochondrial membrane (TIM23 complex) mediates import of precursor proteins with cleavable amino-terminal presequences. Presequences direct precursors across the inner membrane. The combination of this presequence with adjacent regions determines if a precursor is fully translocated into the matrix or laterally sorted into the inner mitochondrial membrane. The membrane-embedded TIM23(SORT) complex mediates the membrane potential-dependent membrane insertion of precursor proteins with a stop-transfer sequence downstream of the mitochondrial targeting signal. In contrast, translocation of precursor proteins into the matrix requires the recruitment of the presequence translocase-associated motor (PAM) to the TIM23 complex. This ATP-driven import motor consists of mitochondrial Hsp70 and several membrane-associated co-chaperones. These two structurally and functionally distinct forms of the TIM23 complex (TIM23(SORT) and TIM23(MOTOR)) are in a dynamic equilibrium with each other. In this review, we discuss recent advances in our understanding of the mechanisms of matrix translocation and membrane insertion by the TIM23 machinery.}, }
@article {pmid20100520, year = {2010}, author = {Kovács-Bogdán, E and Soll, J and Bölter, B}, title = {Protein import into chloroplasts: the Tic complex and its regulation.}, journal = {Biochimica et biophysica acta}, volume = {1803}, number = {6}, pages = {740-747}, doi = {10.1016/j.bbamcr.2010.01.015}, pmid = {20100520}, issn = {0006-3002}, mesh = {Arabidopsis/metabolism ; Arabidopsis Proteins/*metabolism ; Calcium/metabolism ; Chloroplasts/*metabolism ; Endoplasmic Reticulum/metabolism ; Mitochondria/metabolism ; Models, Biological ; Nuclear Proteins/*metabolism ; Oxidation-Reduction ; Protein Processing, Post-Translational ; Protein Transport ; }, abstract = {Chloroplasts like mitochondria were derived from an endosymbiontic event. Due to the massive gene transfer to the nucleus during endosymbiosis, only a limited number of chloroplastic proteins are still encoded for in the plastid genome. Most of the nuclear-encoded plastidic proteins are post-translationally translocated back to the chloroplast via the general import pathway through distinct outer and inner envelope membrane protein complexes, the Toc and Tic translocons (Translocon at the outer/inner envelope membrane of chloroplasts). Eight Tic subunits have been described so far, including two potential channel proteins (Tic110 and Tic20), the "motor complex" (Tic40 associated with the stromal chaperone Hsp93) and the "redox regulon" (Tic62, Tic55, and Tic32) involved in regulation of protein import via the metabolic redox status of the chloroplast. Regulation can additionally occur via thioredoxins (Tic110 and Tic55) or via the calcium/calmodulin network (Tic110 and Tic32). In this review we present the current knowledge about the Tic complex focusing on its regulation and addressing some still open questions.}, }
@article {pmid20097822, year = {2010}, author = {Tang, M and Lv, L and Jing, S and Zhu, L and He, G}, title = {Bacterial symbionts of the brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae).}, journal = {Applied and environmental microbiology}, volume = {76}, number = {6}, pages = {1740-1745}, pmid = {20097822}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gastrointestinal Tract/microbiology ; Hemiptera/*microbiology ; In Situ Hybridization ; Molecular Sequence Data ; Oryza/parasitology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The brown planthopper (Nilaparvata lugens Stål), the most destructive pest of rice, has been identified, including biotypes with high virulence towards previously resistant rice varieties. There have also been many reports of a yeast-like symbiont of N. lugens, but little is known about the bacterial microbes. In this study, we examined the bacterial microbes in N. lugens and identified a total of 18 operational taxonomic units (OTUs) representing four phyla (Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes) by sequencing and analyzing 16S rRNA gene libraries obtained from three populations of N. lugens, which were maintained on the rice varieties TN1, Mudgo, and ASD7. Several of the OTUs were similar to previously reported secondary symbionts of other insects, including an endosymbiont of the psyllid Glycapsis brimblecombei, an Asaia sp. found in the mosquito Anopheles stephensi, and Wolbachia, found in the mite Metaseiulus occidentalis. However, the species and numbers of the detected OTUs differed substantially among the N. lugens populations. Further, in situ hybridization analysis using digoxigenin-labeled probes indicated that OTU 1 was located in hypogastrium tissues near the ovipositor and ovary in biotype 1 insects, while OTU 2 was located in the front of the ovipositor sheath in biotype 2 insects. In addition, masses of bacterium-like organisms were observed in the tubes of salivary sheaths in rice plant tissues that the insects had fed upon. The results provide indications of the diversity of the bacterial microbes harbored by the brown planthopper and of possible associations between specific bacterial microbes and biotypes of N. lugens.}, }
@article {pmid20097813, year = {2010}, author = {Baldridge, GD and Burkhardt, NY and Labruna, MB and Pacheco, RC and Paddock, CD and Williamson, PC and Billingsley, PM and Felsheim, RF and Kurtti, TJ and Munderloh, UG}, title = {Wide dispersal and possible multiple origins of low-copy-number plasmids in rickettsia species associated with blood-feeding arthropods.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {6}, pages = {1718-1731}, pmid = {20097813}, issn = {1098-5336}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI081690/AI/NIAID NIH HHS/United States ; R01 AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/*genetics ; Heat-Shock Proteins/genetics ; Humans ; Molecular Sequence Data ; Phylogeny ; Plasmids/*genetics ; Rickettsia/*genetics/isolation &amp; purification ; Rickettsia Infections/*microbiology ; Sequence Analysis, DNA ; Sequence Homology ; Ticks/*microbiology ; }, abstract = {Plasmids are mobile genetic elements of bacteria that can impart important adaptive traits, such as increased virulence or antibiotic resistance. We report the existence of plasmids in Rickettsia (Rickettsiales; Rickettsiaceae) species, including Rickettsia akari, "Candidatus Rickettsia amblyommii," R. bellii, R. rhipicephali, and REIS, the rickettsial endosymbiont of Ixodes scapularis. All of the rickettsiae were isolated from humans or North and South American ticks. R. parkeri isolates from both continents did not possess plasmids. We have now demonstrated plasmids in nearly all Rickettsia species that we have surveyed from three continents, which represent three of the four major proposed phylogenetic groups associated with blood-feeding arthropods. Gel-based evidence consistent with the existence of multiple plasmids in some species was confirmed by cloning plasmids with very different sequences from each of two "Ca. Rickettsia amblyommii" isolates. Phylogenetic analysis of rickettsial ParA plasmid partitioning proteins indicated multiple parA gene origins and plasmid incompatibility groups, consistent with possible multiple plasmid origins. Phylogenetic analysis of potentially host-adaptive rickettsial small heat shock proteins showed that hsp2 genes were plasmid specific and that hsp1 genes, found only on plasmids of "Ca. Rickettsia amblyommii," R. felis, R. monacensis, and R. peacockii, were probably acquired independently of the hsp2 genes. Plasmid copy numbers in seven Rickettsia species ranged from 2.4 to 9.2 per chromosomal equivalent, as determined by real-time quantitative PCR. Plasmids may be of significance in rickettsial evolution and epidemiology by conferring genetic plasticity and host-adaptive traits via horizontal gene transfer that counteracts the reductive genome evolution typical of obligate intracellular bacteria.}, }
@article {pmid20093081, year = {2010}, author = {Gosalbes, MJ and Latorre, A and Lamelas, A and Moya, A}, title = {Genomics of intracellular symbionts in insects.}, journal = {International journal of medical microbiology : IJMM}, volume = {300}, number = {5}, pages = {271-278}, doi = {10.1016/j.ijmm.2009.12.001}, pmid = {20093081}, issn = {1618-0607}, mesh = {Animals ; Bacteria/*genetics/isolation &amp; purification/*metabolism ; Bacterial Physiological Phenomena ; *Genomics ; Insecta/*microbiology ; Metabolic Networks and Pathways/*genetics ; *Symbiosis ; }, abstract = {Endosymbiotic bacteria play a vital role in the evolution of many insect species. For instance, endosymbionts have evolved metabolically to complement their host's natural diet, thereby enabling them to explore new habitats. In this paper, we will review and give some examples of the nature of the metabolic coupling of different primary and secondary endosymbionts that have evolved in hosts with different nutritional diets (i.e., phloem, xylem, blood, omnivores, and grain). Particular emphasis is given to the evolutionary functional convergence of phylogenetically distant endosymbionts, which are evolving in hosts with similar diets.}, }
@article {pmid20087394, year = {2010}, author = {Raychoudhury, R and Desjardins, CA and Buellesbach, J and Loehlin, DW and Grillenberger, BK and Beukeboom, L and Schmitt, T and Werren, JH}, title = {Behavioral and genetic characteristics of a new species of Nasonia.}, journal = {Heredity}, volume = {104}, number = {3}, pages = {278-288}, pmid = {20087394}, issn = {1365-2540}, support = {R24 GM084917/GM/NIGMS NIH HHS/United States ; R24 GM084917-02/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; *Behavior, Animal ; Evolution, Molecular ; Female ; Male ; Phylogeny ; Sexual Behavior, Animal ; Wasps/anatomy &amp; histology/*classification/*genetics/physiology ; }, abstract = {Nasonia (Hymenoptera: Pteromalidae) is a genus of parasitoid wasps, which is fast emerging as a model system for evolutionary, genetic, developmental and host-endosymbiont interaction studies. In this study, we report a new species, Nasonia oneida, distinguish its behavioral, genetic and morphological features, and characterize its pre-mating and post-mating isolation with the other Nasonia species. Phylogenetic analyses indicate that N. oneida is the sister species to Nasonia giraulti with its own uniquely distinct cuticular hydrocarbon profiles, behavioral characteristics and subtle morphological differences. An important characteristic of N. oneida is the strong mate discrimination shown by the females against all the other Nasonia species. A genetic analysis of this phenotype by interspecies hybridization indicates that this strong discriminating phenotype is recessive. A formal species description of N. oneida Raychoudhury &amp; Desjardins is also provided.}, }
@article {pmid20083406, year = {2010}, author = {Kent, BN and Bordenstein, SR}, title = {Phage WO of Wolbachia: lambda of the endosymbiont world.}, journal = {Trends in microbiology}, volume = {18}, number = {4}, pages = {173-181}, pmid = {20083406}, issn = {1878-4380}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; R01 GM085163-01/GM/NIGMS NIH HHS/United States ; R01 GM085163-02/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Arthropods/microbiology/physiology ; Bacteriophage lambda/genetics/physiology ; Bacteriophages/genetics/*physiology ; Evolution, Molecular ; *Symbiosis ; Wolbachia/genetics/*physiology/*virology ; }, abstract = {The discovery of an extraordinarily high level of mobile elements in the genome of Wolbachia, a widespread arthropod and nematode endosymbiont, suggests that this bacterium could be an excellent model for assessing the evolution and function of mobile DNA in specialized bacteria. In this paper, we discuss how studies on the temperate bacteriophage WO of Wolbachia have revealed unexpected levels of genomic flux and are challenging previously held views about the clonality of obligate intracellular bacteria. We also discuss the roles this phage might play in the Wolbachia-arthropod symbiosis and infer how this research can be translated to combating human diseases vectored by arthropods. We expect that this temperate phage will be a preeminent model system to understand phage genetics, evolution and ecology in obligate intracellular bacteria. In this sense, phage WO might be likened to phage lambda of the endosymbiont world.}, }
@article {pmid20081357, year = {2010}, author = {Haselkorn, TS}, title = {The Spiroplasma heritable bacterial endosymbiont of Drosophila.}, journal = {Fly}, volume = {4}, number = {1}, pages = {80-87}, doi = {10.4161/fly.4.1.10883}, pmid = {20081357}, issn = {1933-6942}, mesh = {Animals ; Bacterial Infections/transmission ; Biodiversity ; Biological Evolution ; Drosophila/*microbiology ; Spiroplasma/*physiology ; *Symbiosis ; }, abstract = {Since the discovery of the small, gram-positive bacteria, Spiroplasma, as a sex-ratio distorting agent in Drosophila over 50 years ago, substantial progress has been made in understanding the relationship of this bacteria with its insect host. Thus far, Spiroplasma have been found as heritable endosymbionts in sixteen different species of Drosophila. In some species these bacteria cause a male-killing phenotype, where the males die during embryogenesis. In other species, however, Spiroplasma does not cause male-killing, and its fitness effects are unclear. Though recent research has identified multiple factors that affect the prevalence and transmission of Spiroplasma in Drosophila populations, much work remains to fully characterize this symbiosis. Spiroplasma is the only identified heritable bacterial endosymbiont of Drosophila, other than Wolbachia, and can serve as a useful as model for elucidating the nature of insect/bacterial interactions.}, }
@article {pmid22476074, year = {2010}, author = {Pyke, KA}, title = {Plastid division.}, journal = {AoB PLANTS}, volume = {2010}, number = {}, pages = {plq016}, pmid = {22476074}, issn = {2041-2851}, abstract = {BACKGROUND AND AIMS: Plastids undergo a process of binary fission in order to replicate. Plastid replication is required at two distinct stages of plant growth: during cell division to ensure correct plastid segregation, and during cell expansion and development to generate large populations of functional plastids, as in leaf mesophyll cells. This review considers some of the recent advances in the understanding of how plastids undergo binary fission, a process which uses several different proteins, both internal and external to the plastid, which have been derived from the original endosymbiont's genome as well as new proteins that have been recruited from the host genome.<br><br>KEY POINTS: Several of the proteins currently used in this process in higher plants have homologues in modern-day bacteria. An alternative mode of replication by a budding-type mechanism also appears to be used in some circumstances. The review also highlights how most of our knowledge of plastid division is centred on the chloroplast developing in leaf mesophyll cells and a role for plastid division during the development of other plastid types is poorly understood. Whilst models for a protein-based mechanism have been devised, exactly how the division process is controlled at the plastid level and at the plastid population level is poorly understood.}, }
@article {pmid21687765, year = {2010}, author = {Georgiades, K and Raoult, D}, title = {Defining pathogenic bacterial species in the genomic era.}, journal = {Frontiers in microbiology}, volume = {1}, number = {}, pages = {151}, pmid = {21687765}, issn = {1664-302X}, abstract = {Actual definitions of bacterial species are limited due to the current criteria of definition and the use of restrictive genetic tools. The 16S ribosomal RNA sequence, for example, has been widely used as a marker for phylogenetic analyses; however, its use often leads to misleading species definitions. According to the first genetic studies, removing a certain number of genes from pathogenic bacteria removes their capacity to infect hosts. However, more recent studies have demonstrated that the specialization of bacteria in eukaryotic cells is associated with massive gene loss, especially for allopatric endosymbionts that have been isolated for a long time in an intracellular niche. Indeed, sympatric free-living bacteria often have bigger genomes and exhibit greater resistance and plasticity and constitute species complexes rather than true species. Specialists, such as pathogenic bacteria, escape these bacterial complexes and colonize a niche, thereby gaining a species name. Their specialization allows them to become allopatric, and their gene losses eventually favor reductive genome evolution. A pathogenic species is characterized by a gene repertoire that is defined not only by genes that are present but also by those that are lacking. It is likely that current bacterial pathogens will disappear soon and be replaced by new ones that will emerge from bacterial complexes that are already in contact with humans.}, }
@article {pmid21687758, year = {2010}, author = {Price, CT and Kwaik, YA}, title = {Exploitation of Host Polyubiquitination Machinery through Molecular Mimicry by Eukaryotic-Like Bacterial F-Box Effectors.}, journal = {Frontiers in microbiology}, volume = {1}, number = {}, pages = {122}, pmid = {21687758}, issn = {1664-302X}, support = {R01 AI043965/AI/NIAID NIH HHS/United States ; R01 AI069321/AI/NIAID NIH HHS/United States ; }, abstract = {Microbial pathogens have evolved exquisite mechanisms to interfere and intercept host biological processes, often through molecular mimicry of specific host proteins. Ubiquitination is a highly conserved eukaryotic post-translational modification essential in determining protein fate, and is often hijacked by pathogenic bacteria. The conserved SKP1/CUL1/F-box (SCF) E3 ubiquitin ligase complex plays a key role in ubiquitination of proteins in eukaryotic cells. The F-box protein component of the SCF complex provides specificity to ubiquitination by binding to specific cellular proteins, targeting them to be ubiquitinated by the SCF complex. The bacterial pathogens. Legionella pneumophila, Agrobacterium tumefaciens, and Ralstonia solanacearum utilize type III or IV translocation systems to inject into the host cell eukaryotic-like F-box effectors that interact with the host SKP1 component of the SCF complex to trigger ubiquitination of specific host cells targets, which is essential to promote proliferation of these pathogens. Our bioinformatic analyses have identified at least 74 genes encoding putative F-box proteins belonging to 22 other bacterial species, including human pathogens, plant pathogens, and amebal endosymbionts. Therefore, subversion of the host ubiquitination machinery by bacterial F-box proteins may be a widespread strategy amongst pathogenic bacteria. The findings that bacterial F-box proteins harbor Ankyrin repeats as protein-protein interaction domains, which are present in F-box proteins of primitive but not higher eukaryotes, suggest acquisition of many bacterial F-box proteins from primitive eukaryotic hosts rather than the mammalian host.}, }
@article {pmid20036630, year = {2010}, author = {Brooks, CF and Johnsen, H and van Dooren, GG and Muthalagi, M and Lin, SS and Bohne, W and Fischer, K and Striepen, B}, title = {The toxoplasma apicoplast phosphate translocator links cytosolic and apicoplast metabolism and is essential for parasite survival.}, journal = {Cell host &amp; microbe}, volume = {7}, number = {1}, pages = {62-73}, pmid = {20036630}, issn = {1934-6069}, support = {R56 AI084415-01/AI/NIAID NIH HHS/United States ; AI64671/AI/NIAID NIH HHS/United States ; R01 AI064671-04/AI/NIAID NIH HHS/United States ; AI084415/AI/NIAID NIH HHS/United States ; R56 AI084415/AI/NIAID NIH HHS/United States ; R01 AI084415/AI/NIAID NIH HHS/United States ; R01 AI064671/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Energy Metabolism ; Gene Knockout Techniques ; Genes, Essential ; Membrane Transport Proteins/*metabolism ; Metabolic Networks and Pathways ; Microbial Viability ; Models, Biological ; Organelles/*physiology ; Phosphates/*metabolism ; Toxoplasma/*physiology ; }, abstract = {Apicomplexa are unicellular eukaryotic pathogens that carry a vestigial algal endosymbiont, the apicoplast. The physiological function of the apicoplast and its integration into parasite metabolism remain poorly understood and at times controversial. We establish that the Toxoplasma apicoplast membrane-localized phosphate translocator (TgAPT) is an essential metabolic link between the endosymbiont and the parasite cytoplasm. TgAPT is required for fatty acid synthesis in the apicoplast, but this may not be its most critical function. Further analyses demonstrate that TgAPT also functions to supply the apicoplast with carbon skeletons for additional pathways and, indirectly, with energy and reduction power. Genetic ablation of the transporter results in rapid death of parasites. The dramatic consequences of loss of its activity suggest that targeting TgAPT could be a viable strategy to identify antiparasitic compounds.}, }
@article {pmid20035767, year = {2010}, author = {Perlman, SJ and Magnus, SA and Copley, CR}, title = {Pervasive associations between Cybaeus spiders and the bacterial symbiont Cardinium.}, journal = {Journal of invertebrate pathology}, volume = {103}, number = {3}, pages = {150-155}, doi = {10.1016/j.jip.2009.12.009}, pmid = {20035767}, issn = {1096-0805}, mesh = {Animals ; Bacteroidetes/*genetics/pathogenicity ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Gene Transfer, Horizontal ; Haplotypes ; Male ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Spiders/*genetics/*microbiology ; Symbiosis/*genetics ; }, abstract = {Cardinium is a recently discovered maternally transmitted bacterial endosymbiont in the Bacteroidetes that has thus far been documented in five arthropod orders. While its effects on his hosts are largely unknown, a few strains have been shown to manipulate host reproduction in parasitic wasps and in mites, either by transforming males into females, or by causing mating incompatibilities between infected males and uninfected males. Cardinium has recently been reported to be widespread in spiders, and in this study, we document pervasive infections in Cybaeus spiders, which are some of the most abundant yet understudied spiders in the understory of moist Western North American forests. 12/20 species, as well as 96% of individuals in a local population of Cybaeus signifer were infected. Phylogenetic analysis revealed three closely related symbiont haplotypes within Cybaeus. Haplotypes clustered within geographically close species, suggesting that horizontal transmission might be quite high in this symbiont lineage.}, }
@article {pmid20034492, year = {2010}, author = {Tompkins, JB and Stitt, LE and Ardelli, BF}, title = {Brugia malayi: in vitro effects of ivermectin and moxidectin on adults and microfilariae.}, journal = {Experimental parasitology}, volume = {124}, number = {4}, pages = {394-402}, doi = {10.1016/j.exppara.2009.12.003}, pmid = {20034492}, issn = {1090-2449}, mesh = {Analysis of Variance ; Animals ; Antinematodal Agents/*pharmacology ; Antiparasitic Agents/*pharmacology ; Brugia malayi/*drug effects/microbiology/physiology ; Female ; Fertility/drug effects ; Gerbillinae ; Ivermectin/*pharmacology ; Macrolides/pharmacology ; Male ; Microfilariae/drug effects/microbiology/physiology ; Movement/drug effects ; Polymerase Chain Reaction ; RNA, Bacterial/analysis ; Random Allocation ; Time Factors ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {The effect of ivermectin and moxidectin on the motility of Brugia malayi adults and microfilariae and on the fertility of B. malayi females was examined. Motility was reduced in adults after exposure to both drugs and worms were non-motile and dead within eight days. The motility of microfilariae was significantly reduced at all drug concentrations and ceased at concentrations of 2500 and 5000mug/mL. The motility of microfilariae released by females was reduced after exposure to both drugs, however ivermectin had a greater effect at concentrations between 170 and 5000mug/mL. Both drugs reduced the number of microfilariae released by females and within four days their release was inhibited. The presence of the bacterial endosymbiont Wolbachia was examined in adults and microfilariae after exposure to increasing concentrations of ivermectin and moxidectin. A decrease in wsp expression was correlated with increasing drug concentration.}, }
@article {pmid20031220, year = {2010}, author = {Iovieno, A and Ledee, DR and Miller, D and Alfonso, EC}, title = {Detection of bacterial endosymbionts in clinical acanthamoeba isolates.}, journal = {Ophthalmology}, volume = {117}, number = {3}, pages = {445-52, 452.e1-3}, pmid = {20031220}, issn = {1549-4713}, support = {P30 EY014801/EY/NEI NIH HHS/United States ; P30 EY014801-01A1/EY/NEI NIH HHS/United States ; P30: EY014801/EY/NEI NIH HHS/United States ; }, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology ; Acanthamoeba Keratitis/microbiology/*parasitology ; Animals ; Chlamydia/genetics/*isolation &amp; purification ; Contact Lenses/microbiology/*parasitology ; Cornea/microbiology/parasitology ; DNA, Bacterial/analysis ; Genotype ; Humans ; In Situ Hybridization, Fluorescence ; Legionella/genetics/*isolation &amp; purification ; Microscopy, Electron, Transmission ; Mycobacterium/genetics/*isolation &amp; purification ; Polymerase Chain Reaction ; Pseudomonas/genetics/*isolation &amp; purification ; Symbiosis ; }, abstract = {PURPOSE: To determine the presence of 4 clinically relevant bacterial endosymbionts in Acanthamoeba isolates obtained from patients with Acanthamoeba keratitis (AK) and the possible contribution of endosymbionts to the pathogenesis of AK.<br><br>DESIGN: Experimental study.<br><br>PARTICIPANTS: Acanthamoeba isolates (N = 37) recovered from the cornea and contact lens paraphernalia of 23 patients with culture-proven AK and 1 environmental isolate.<br><br>METHODS: Acanthamoeba isolates were evaluated for the presence of microbial endosymbionts belonging to the bacterial genera Legionella, Pseudomonas, Mycobacterium, and Chlamydia using molecular techniques (polymerase chain reaction and sequence analysis, fluorescence in situ hybridization) and transmission electron microscopy. Corneal toxicity and virulence of Acanthamoeba isolates with and without endosymbionts were compared using a cytopathic effect (CPE) assay on human corneal epithelial cells in vitro. Initial visual acuity, location and characteristics of the infiltrate, time to detection of the infection, and symptom duration at presentation were evaluated in all patients.<br><br>MAIN OUTCOME MEASURES: Prevalence and potential pathobiology of bacterial endosymbionts detected in Acanthamoeba isolates recovered from AK.<br><br>RESULTS: Twenty-two (59.4%) of the 38 cultures examined contained at least 1 bacterial endosymbiont. One isolate contained 2 endosymbionts, Legionella and Chlamydia, confirmed by fluorescence in situ hybridization. Corneal toxicity (CPE) was significantly higher for Acanthamoeba-hosting endosymbionts compared with isolates without endosymbionts (P<0.05). Corneal pathogenic endosymbionts such as Pseudomonas and Mycobacterium enhanced Acanthamoeba CPE significantly more than Legionella (P<0.05). In the presence of bacterial endosymbionts, there was a trend toward worse initial visual acuity (P>0.05), central location (P<0.05), absence of radial perineuritis (P<0.05), delayed time to detection (P>0.05), and longer symptom duration at presentation (P>0.05).<br><br>CONCLUSIONS: Most Acanthamoeba isolates responsible for AK harbor 1 or more bacterial endosymbionts. The presence of endosymbionts enhances the corneal pathogenicity of Acanthamoeba isolates and may impact detection time and clinical features of AK.}, }
@article {pmid20027221, year = {2009}, author = {Felsheim, RF and Kurtti, TJ and Munderloh, UG}, title = {Genome sequence of the endosymbiont Rickettsia peacockii and comparison with virulent Rickettsia rickettsii: identification of virulence factors.}, journal = {PloS one}, volume = {4}, number = {12}, pages = {e8361}, pmid = {20027221}, issn = {1932-6203}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; 2R01 AI49424-06A2/AI/NIAID NIH HHS/United States ; }, mesh = {Base Sequence ; Codon, Nonsense/genetics ; DNA Transposable Elements/genetics ; Gene Deletion ; Genome, Bacterial/*genetics ; Multigene Family/genetics ; Phylogeny ; Plasmids/genetics ; Rickettsia/*genetics ; Rickettsia rickettsii/*genetics/*pathogenicity ; Sequence Alignment ; Symbiosis/*genetics ; Virulence/genetics ; Virulence Factors/*genetics ; }, abstract = {Rickettsia peacockii, also known as the East Side Agent, is a non-pathogenic obligate intracellular bacterium found as an endosymbiont in Dermacentor andersoni ticks in the western USA and Canada. Its presence in ticks is correlated with reduced prevalence of Rickettsia rickettsii, the agent of Rocky Mountain Spotted Fever. It has been proposed that a virulent SFG rickettsia underwent changes to become the East Side Agent. We determined the genome sequence of R. peacockii and provide a comparison to a closely related virulent R. rickettsii. The presence of 42 chromosomal copies of the ISRpe1 transposon in the genome of R. peacockii is associated with a lack of synteny with the genome of R. rickettsii and numerous deletions via recombination between transposon copies. The plasmid contains a number of genes from distantly related organisms, such as part of the glycosylation island of Pseudomonas aeruginosa. Genes deleted or mutated in R. peacockii which may relate to loss of virulence include those coding for an ankyrin repeat containing protein, DsbA, RickA, protease II, OmpA, ScaI, and a putative phosphoethanolamine transferase. The gene coding for the ankyrin repeat containing protein is especially implicated as it is mutated in R. rickettsii strain Iowa, which has attenuated virulence. Presence of numerous copies of the ISRpe1 transposon, likely acquired by lateral transfer from a Cardinium species, are associated with extensive genomic reorganization and deletions. The deletion and mutation of genes possibly involved in loss of virulence have been identified by this genomic comparison. It also illustrates that the introduction of a transposon into the genome can have varied effects; either correlating with an increase in pathogenicity as in Francisella tularensis or a loss of pathogenicity as in R. peacockii and the recombination enabled by multiple transposon copies can cause significant deletions in some genomes while not in others.}, }
@article {pmid20023413, year = {2010}, author = {Okazaki, K and Kabeya, Y and Miyagishima, SY}, title = {The evolution of the regulatory mechanism of chloroplast division.}, journal = {Plant signaling &amp; behavior}, volume = {5}, number = {2}, pages = {164-167}, pmid = {20023413}, issn = {1559-2324}, abstract = {Chloroplasts arose from a cyanobacterial endosymbiont and multiply by division, reminiscent of their free-living ancestor. However, chloroplasts can not divide by themselves, and the division is performed and controlled by proteins that are encoded by the host nucleus. The continuity of chloroplasts was originally established by synchronization of endosymbiotic cell division with host cell division, as seen in existent algae. In contrast, land plant cells contain multiple chloroplasts, the division of which is not synchronized, even in the same cell. Land plants have evolved cell and chloroplast differentiation systems in which the size and number of chloroplasts (or other types of plastids) change along with their respective cellular function by changes in the division rate. We recently reported that PLASTID DIVISION (PDV) proteins, land-plant specific components of the chloroplast division apparatus, determined the rate of chloroplast division. The level of PDV protein is regulated by the cell differentiation program based on cytokinin, and the increase or decrease of the PDV level gives rise to an increase or decrease in the chloroplast division rate. Thus, the integration of PDV proteins into the chloroplast division machinery enabled land plant cells to change chloroplast size and number in accord with the fate of cell differentiation.}, }
@article {pmid20022511, year = {2010}, author = {Caetano, FH and Zara, FJ and Bution, ML}, title = {A new strategy of endosymbiont midgut bacteria in ant (Ponerinae).}, journal = {Micron (Oxford, England : 1993)}, volume = {41}, number = {3}, pages = {183-186}, doi = {10.1016/j.micron.2009.11.007}, pmid = {20022511}, issn = {1878-4291}, mesh = {Animals ; Ants/*microbiology ; Bacteria/*isolation &amp; purification/ultrastructure ; Gastrointestinal Tract/microbiology/ultrastructure ; Intestinal Mucosa/microbiology/ultrastructure ; Microscopy, Electron, Transmission ; }, abstract = {The location and ultrastructure of bacteria associated with microvilli in the midgut of Odontomachus bauri were examined by transmission electron microscopy. These filamentous type bacteria are the second morphotype described in the midgut of this ant. They colonizes only the ectoperitrophic space, more specifically attaching along microvilli. A thick capsule attaches bacteria to microvilli and protect them from acidic pH and digestive enzymes. Details of the location and association with microvilli are discussed.}, }
@article {pmid20015388, year = {2009}, author = {Wernegreen, JJ and Kauppinen, SN and Brady, SG and Ward, PS}, title = {One nutritional symbiosis begat another: phylogenetic evidence that the ant tribe Camponotini acquired Blochmannia by tending sap-feeding insects.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {292}, pmid = {20015388}, issn = {1471-2148}, support = {R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/*classification/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Gammaproteobacteria/classification/genetics/*physiology ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: Bacterial endosymbiosis has a recurring significance in the evolution of insects. An estimated 10-20% of insect species depend on bacterial associates for their nutrition and reproductive viability. Members of the ant tribe Camponotini, the focus of this study, possess a stable, intracellular bacterial mutualist. The bacterium, Blochmannia, was first discovered in Camponotus and has since been documented in a distinct subgenus of Camponotus, Colobopsis, and in the related genus Polyrhachis. However, the distribution of Blochmannia throughout the Camponotini remains in question. Documenting the true host range of this bacterial mutualist is an important first step toward understanding the various ecological contexts in which it has evolved, and toward identifying its closest bacterial relatives. In this study, we performed a molecular screen, based on PCR amplification of 16S rDNA, to identify bacterial associates of diverse Camponotini species.<br><br>RESULTS: Phylogenetic analyses of 16S rDNA gave four important insights: (i) Blochmannia occurs in a broad range of Camponotini genera including Calomyrmex, Echinopla, and Opisthopsis, and did not occur in outgroups related to this tribe (e.g., Notostigma). This suggests that the mutualism originated in the ancestor of the tribe Camponotini. (ii) The known bacteriocyte-associated symbionts of ants, in Formica, Plagiolepis, and the Camponotini, arose independently. (iii) Blochmannia is nestled within a diverse clade of endosymbionts of sap-feeding hemipteran insects, such as mealybugs, aphids, and psyllids. In our analyses, a group of secondary symbionts of mealybugs are the closest relatives of Blochmannia. (iv) Blochmannia has cospeciated with its known hosts, although deep divergences at the genus level remain uncertain.<br><br>CONCLUSIONS: The Blochmannia mutualism occurs in Calomyrmex, Echinopla, and Opisthopsis, in addition to Camponotus, and probably originated in the ancestral lineage leading to the Camponotini. This significant expansion of its known host range implies that the mutualism is more ancient and ecologically diverse than previously documented. Blochmannia is most closely related to endosymbionts of sap-feeding hemipterans, which ants tend for their carbohydrate-rich honeydew. Based on phylogenetic results, we propose Camponotini might have originally acquired this bacterial mutualist through a nutritional symbiosis with other insects.}, }
@article {pmid20015249, year = {2010}, author = {Gibson, CM and Hunter, MS}, title = {Extraordinarily widespread and fantastically complex: comparative biology of endosymbiotic bacterial and fungal mutualists of insects.}, journal = {Ecology letters}, volume = {13}, number = {2}, pages = {223-234}, doi = {10.1111/j.1461-0248.2009.01416.x}, pmid = {20015249}, issn = {1461-0248}, mesh = {Animals ; *Bacteria ; *Biological Evolution ; *Fungi ; Insecta/*microbiology ; *Symbiosis ; }, abstract = {Endosymbiosis is a pervasive, powerful force in arthropod evolution. In the recent literature, bacterial symbionts of insects have been shown to function as reproductive manipulators, nutritional mutualists and as defenders of their hosts. Fungi, like bacteria, are also frequently associated with insects. Initial estimates suggest that insect-fungal endosymbionts are hyperdiverse, yet there has been comparatively little research investigating the roles that fungi play in their insect hosts. In many systems in which the bacterial symbionts are well-characterized, the possible presence of fungi has been routinely ignored. Why has there been so little research on this important group of symbionts? Here, we explore the differences between fungal and bacterial endosymbiotic insect mutualists. We make predictions about why a bacterium or fungus might be found associated with an insect host given particular ecological, physiological, or evolutionary conditions. We also touch on the various hurdles for studying fungal vs. bacterial endosymbionts and potential future research directions.}, }
@article {pmid20002580, year = {2010}, author = {Jaenike, J and Stahlhut, JK and Boelio, LM and Unckless, RL}, title = {Association between Wolbachia and Spiroplasma within Drosophila neotestacea: an emerging symbiotic mutualism?.}, journal = {Molecular ecology}, volume = {19}, number = {2}, pages = {414-425}, doi = {10.1111/j.1365-294X.2009.04448.x}, pmid = {20002580}, issn = {1365-294X}, mesh = {Animals ; Cytoplasm/genetics ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Drosophila/genetics/*microbiology ; Evolution, Molecular ; Female ; Haplotypes ; Male ; *Phylogeny ; Spiroplasma/*genetics ; *Symbiosis ; Wolbachia/*genetics ; }, abstract = {Interspecific mutualism can evolve when specific lineages of different species tend to be associated with each other from one generation to the next. Different maternally transmitted endosymbionts occurring within the same cytoplasmic lineage fulfil this requirement. Drosophila neotestacea is infected with maternally transmitted Wolbachia and Spiroplasma, which are cotransmitted at high frequency in natural populations. Molecular phylogenetic evidence indicates that both endosymbionts have been present in D. neotestacea for considerable evolutionary periods. Thus, conditions are suitable for the evolution of mutualism between them. In support of this possibility, there is a significant positive association between Wolbachia and Spiroplasma infection in many samples of D. neotestacea from natural populations. Theoretically, such a positive association can result from either mutualism between these endosymbionts or recent spread. Collections from present-day populations suggest that recent spread and mutualism have both operated to generate the positive association between Wolbachia and Spiroplasma. If selection acts on the combination of these two endosymbionts, they may be in the early stages of evolution of a more complex, cooperative association.}, }
@article {pmid19968994, year = {2010}, author = {Korený, L and Lukes, J and Oborník, M}, title = {Evolution of the haem synthetic pathway in kinetoplastid flagellates: an essential pathway that is not essential after all?.}, journal = {International journal for parasitology}, volume = {40}, number = {2}, pages = {149-156}, doi = {10.1016/j.ijpara.2009.11.007}, pmid = {19968994}, issn = {1879-0135}, mesh = {*Biological Evolution ; Gammaproteobacteria/physiology ; Heme/*biosynthesis ; Kinetoplastida/classification/genetics/*metabolism/*microbiology ; Phylogeny ; Protozoan Proteins/genetics/metabolism ; Symbiosis ; }, abstract = {For a vast majority of living organisms, haem is an essential compound that is synthesised through a conserved biosynthetic pathway. However, certain organisms are haem auxotrophs and need to obtain this molecule from exogenous sources. Kinetoplastid flagellates represent an interesting group of species, as some of them lost the complete pathway while others possess only the last three biosynthetic steps. We decided to supplement a current view on the phylogeny of these important pathogens with the expected state of haem synthesis in representative species. We propose a scenario in which the ancestor of all trypanosomatids was completely deficient of the synthesis of haem. In trypanosomatids other than members of the genus Trypanosoma, the pathway was partially rescued by genes encoding enzymes for the last three steps, supposedly obtained by horizontal transfer from a gamma-proteobacterium. This event preceded the diversification of the non-Trypanosoma trypanosomatids. Later, some flagellates acquired a beta-proteobacterial endosymbiont which supplied them with haem precursors. On the other hand, the medically important trypanosomes have remained fully deficient of haem synthesis and obtain this compound from the host.}, }
@article {pmid19967080, year = {2009}, author = {Choi, SH and Cho, MK and Ahn, SC and Lee, JE and Lee, JS and Kim, DH and Xuan, YH and Hong, YC and Kong, HH and Chung, DI and Yu, HS}, title = {Endosymbionts of Acanthamoeba isolated from domestic tap water in Korea.}, journal = {The Korean journal of parasitology}, volume = {47}, number = {4}, pages = {337-344}, pmid = {19967080}, issn = {1738-0006}, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology/ultrastructure ; Alphaproteobacteria/classification/genetics/*isolation &amp; purification ; Animals ; Bacteroidetes/classification/genetics/*isolation &amp; purification ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Fresh Water/*parasitology ; Korea ; Methylophilus/classification/genetics/*isolation &amp; purification ; Microscopy, Electron, Transmission ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {In a previous study, we reported our discovery of Acanthamoeba contamination in domestic tap water; in that study, we determined that some Acanthamoeba strains harbor endosymbiotic bacteria, via our molecular characterization by mitochondrial DNA restriction fragment length polymorphism (Mt DNA RFLP). Five (29.4%) among 17 Acanthamoeba isolates contained endosymbionts in their cytoplasm, as demonstrated via orcein staining. In order to estimate their pathogenicity, we conducted a genetic characterization of the endosymbionts in Acanthamoeba isolated from domestic tap water via 16S rDNA sequencing. The endosymbionts of Acanthamoeba sp. KA/WP3 and KA/WP4 evidenced the highest level of similarity, at 97% of the recently published 16S rDNA sequence of the bacterium, Candidatus Amoebophilus asiaticus. The endosymbionts of Acanthamoeba sp. KA/WP8 and KA/WP12 shared a 97% sequence similarity with each other, and were also highly similar to Candidatus Odyssella thessalonicensis, a member of the alpha-proteobacteria. The endosymbiont of Acanthamoeba sp. KA/WP9 exhibits a high degree of similarity (85-95%) with genus Methylophilus, which is not yet known to harbor any endosymbionts. This is the first report, to the best of our knowledge, to show that Methylophilus spp. can live in the cytoplasm of Acanthamoeba.}, }
@article {pmid19962988, year = {2010}, author = {Francis, F and Guillonneau, F and Leprince, P and De Pauw, E and Haubruge, E and Jia, L and Goggin, FL}, title = {Tritrophic interactions among Macrosiphum euphorbiae aphids, their host plants and endosymbionts: investigation by a proteomic approach.}, journal = {Journal of insect physiology}, volume = {56}, number = {6}, pages = {575-585}, doi = {10.1016/j.jinsphys.2009.12.001}, pmid = {19962988}, issn = {1879-1611}, mesh = {Animals ; Aphids/chemistry/microbiology/*physiology ; Bacterial Proteins/isolation &amp; purification ; Cytoskeletal Proteins/analysis/isolation &amp; purification ; Electrophoresis, Gel, Two-Dimensional ; Insect Proteins/isolation &amp; purification ; Lycopersicon esculentum/*parasitology ; Molecular Sequence Data ; Plant Proteins/isolation &amp; purification ; Plants, Genetically Modified/chemistry/parasitology ; Polymerase Chain Reaction ; *Proteomics ; Rickettsia/chemistry/physiology ; Symbiosis/*physiology ; }, abstract = {The Mi-1.2 gene in tomato confers resistance against certain clones of the potato aphid (Macrosiphum euphorbiae). This study used 2D-DIGE coupled with protein identification by MALDI-TOF-MS to compare the proteome patterns of avirulent and semivirulent potato aphids and their bacterial endosymbionts on resistant (Mi-1.2+) and susceptible (Mi-1.2-) tomato lines. Avirulent aphids had low survival on resistant plants, whereas the semivirulent clone could colonize these plants. Eighty-two protein spots showed significant quantitative differences among the four treatment groups, and of these, 48 could be assigned putative identities. Numerous structural proteins and enzymes associated with primary metabolism were more abundant in the semivirulent than in the avirulent aphid clone. Several proteins were also up-regulated in semivirulent aphids when they were transferred from susceptible to resistant plants. Nearly 25% of the differentially regulated proteins originated from aphid endosymbionts and not the aphid itself. Six were assigned to the primary endosymbiont Buchnera aphidicola, and 5 appeared to be derived from a Rickettsia-like secondary symbiont. These results indicate that symbiont expression patterns differ between aphid clones with differing levels of virulence, and are influenced by the aphids' host plant. Potentially, symbionts may contribute to differential adaptation of aphids to host plant resistance.}, }
@article {pmid19962263, year = {2010}, author = {Grünwald, S and Pilhofer, M and Höll, W}, title = {Microbial associations in gut systems of wood- and bark-inhabiting longhorned beetles [Coleoptera: Cerambycidae].}, journal = {Systematic and applied microbiology}, volume = {33}, number = {1}, pages = {25-34}, doi = {10.1016/j.syapm.2009.10.002}, pmid = {19962263}, issn = {1618-0984}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; *Biodiversity ; Cluster Analysis ; Coleoptera/*microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Fungi/*classification/*isolation &amp; purification ; Gastrointestinal Tract/*microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {Using fluorescence in situ hybridization (FISH) techniques and PCR-based rDNA sequencing, gut microflora in the larvae of bark- and wood-inhabiting cerambycid beetles (Rhagium inquisitor, Tetropium castaneum, Plagionotus arcuatus and Leptura rubra [Coleoptera: Cerambycidae]) was investigated. A total of 12 novel ascomycetous yeast strains were isolated from the gut content. Panfungal and strain-specific oligonucleotide probes identified two yeast strains as Candida rhagii and Candida shehatae, which were colonizing specialized organs (mycetomes) adhering to the gut of R. inquisitor and L. rubra larvae, respectively. Fragments containing these organisms were constantly being released from the mycetomes into the gut lumen. Whereas the mycetome symbiont of T. castaneum could not be identified, all larvae of this species harbored an additional bacterial endocytobiont in their gut epithelium. This novel gammaproteobacterium belonged to the Sodalis clade of insect symbionts, which includes the secondary endosymbiont of tsetse flies (Sodalis glossinidius) and the Sitophilus oryzae primary endosymbiont (SOPE). Extracellular gut flora of the investigated cerambycid larvae was comprised of Alpha-, Beta-, and Gammaproteobacteria, Actinobacteria, Firmicutes, Verrucomicrobia and Acidobacteria. However, the individual composition among investigated larvae was highly variable and supposedly depended on individual host nutrition.}, }
@article {pmid19961900, year = {2010}, author = {Olszewski, NE and West, CM and Sassi, SO and Hartweck, LM}, title = {O-GlcNAc protein modification in plants: Evolution and function.}, journal = {Biochimica et biophysica acta}, volume = {1800}, number = {2}, pages = {49-56}, pmid = {19961900}, issn = {0006-3002}, support = {R01 GM037539/GM/NIGMS NIH HHS/United States ; R01 GM037539-09/GM/NIGMS NIH HHS/United States ; R01 GM37539/GM/NIGMS NIH HHS/United States ; }, mesh = {Acetylglucosamine/*metabolism ; Amino Acid Sequence ; Arabidopsis Proteins/physiology ; *Evolution, Molecular ; N-Acetylglucosaminyltransferases/*metabolism/physiology ; Phylogeny ; Plants/genetics/*metabolism ; Protein Processing, Post-Translational ; Protein Structure, Tertiary ; Repetitive Sequences, Amino Acid/genetics ; Repressor Proteins/physiology ; Sequence Alignment ; }, abstract = {The role in plants of posttranslational modification of proteins with O-linked N-acetylglucosamine and the evolution and function of O-GlcNAc transferases responsible for this modification are reviewed. Phylogenetic analysis of eukaryotic O-GlcNAc transferases (OGTs) leads us to propose that plants have two distinct OGTs, SEC- and SPY-like, that originated in prokaryotes. Animals and some fungi have a SEC-like enzyme while plants have both. Green algae and some members of the Apicomplexa and amoebozoa have the SPY-like enzyme. Interestingly the progenitor of the Apicomplexa lineage likely had a photosynthetic plastid that persists in a degenerated form in some species, raising the possibility that plant SPY-like OGTs are derived from a photosynthetic endosymbiont. OGTs have multiple tetratricopeptide repeats (TPRs) that within the SEC- and SPY-like classes exhibit evidence of strong selective pressure on specific repeats, suggesting that the function of these repeats is conserved. SPY-like and SEC-like OGTs have both unique and overlapping roles in the plant. The phenotypes of sec and spy single and double mutants indicate that O-GlcNAc modification is essential and that it affects diverse plant processes including response to hormones and environmental signals, circadian rhythms, development, intercellular transport and virus infection. The mechanistic details of how O-GlcNAc modification affects these processes are largely unknown. A major impediment to understanding this is the lack of knowledge of the identities of the modified proteins.}, }
@article {pmid19957445, year = {2009}, author = {Bator, T and Pado, R}, title = {The influence of hypergravity on the Paramecium bursaria-Chlorella sp. symbiotic association.}, journal = {Zeitschrift fur Naturforschung. C, Journal of biosciences}, volume = {64}, number = {9-10}, pages = {743-746}, doi = {10.1515/znc-2009-9-1021}, pmid = {19957445}, issn = {0939-5075}, mesh = {Chlorella/*physiology ; *Hypergravity ; Paramecium/*physiology ; *Symbiosis ; }, abstract = {The aim of the research was to determine the influence of strong hypergravity on the Paramecium bursaria-Chlorella sp. symbiotic association, which is considered to be a model example of symbiosis between a heterotroph and an autotroph. The paramecia cells were exposed to 1073 x g, 4293 x g, and 9658 x g hypergravity for 15 min. Then they were incubated for 21 d on a standard lettuce medium. The experiments were conducted in parallel under constant white light and in the dark. The changes in the number of paramecia cells during incubation were determined. Measurements of the number of Chlorella sp. endosymbionts inside host cells were also made. The results showed that a 15-min exposure to hypergravity attenuates the subsequent growth of Paramecium bursaria in the dark, but it may stimulate the growth of paramecia under constant light. Moreover, it causes an increase in the number of algae inside the paramecia cells. Presumably, the influence of hypergravity on the studied symbiotic complex is connected with its effect on the endosymbiotic Chlorella sp. cells. This subject requires further research, focused on the influence of hypergravity on the physiology and growth of the Chlorella sp. endosymbionts living inside the Paramecium bursaria cells.}, }
@article {pmid19955479, year = {2010}, author = {Wernegreen, JJ and Kauppinen, SN and Degnan, PH}, title = {Slip into something more functional: selection maintains ancient frameshifts in homopolymeric sequences.}, journal = {Molecular biology and evolution}, volume = {27}, number = {4}, pages = {833-839}, pmid = {19955479}, issn = {1537-1719}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01GM062626/GM/NIGMS NIH HHS/United States ; }, mesh = {Base Sequence ; Enterobacteriaceae/*genetics ; *Frameshift Mutation ; INDEL Mutation ; Poly A/genetics ; Poly T/genetics ; Selection, Genetic ; Transcription, Genetic ; }, abstract = {Mutational hotspots offer significant sources of genetic variability upon which selection can act. However, with a few notable exceptions, we know little about the dynamics and fitness consequences of mutations in these regions. Here, we explore evolutionary forces shaping homopolymeric tracts that are especially vulnerable to slippage errors during replication and transcription. Such tracts are typically eliminated by selection from most bacterial sequences, yet persist in genomes of endosymbionts with small effective population sizes (N(e)) and biased base compositions. Focusing on Blochmannia, a bacterial endosymbiont of ants, we track the divergence of genes that contain frameshift mutations within long (9-11 bp) polyA or polyT tracts. Earlier experimental work documented that transcriptional slippage restores the reading frame in a fraction of messenger RNA molecules and thereby rescues the function of frameshifted genes. In this study, we demonstrate a surprising persistence of these frameshifts and associated tracts for millions of years. Across the genome of this ant mutualist, rates of indel mutation within homopolymeric tracts far exceed the synonymous mutation rate, indicating that long-term conservation of frameshifts within these tracts is inconsistent with neutrality. In addition, the homopolymeric tracts themselves are more conserved than expected by chance, given extensive neutral substitutions that occur elsewhere in the genes sampled. These data suggest an unexpected role for slippage-prone DNA tracts and highlight a new mechanism for their persistence. That is, when such tracts contain a frameshift, transcriptional slippage plays a critical role in rescuing gene function. In such cases, selection will purge nucleotide changes interrupting the slippery tract so that otherwise volatile sequences become frozen in evolutionary time. Although the advantage of the frameshift itself is less clear, it may offer a mechanism to lower effective gene expression by reducing but not eliminating transcripts that encode full-length proteins.}, }
@article {pmid19954456, year = {2009}, author = {Shiny, C and Krushna, NS and Archana, B and Farzana, B and Narayanan, RB}, title = {Serum antibody responses to Wolbachia surface protein in patients with human lymphatic filariasis.}, journal = {Microbiology and immunology}, volume = {53}, number = {12}, pages = {685-693}, doi = {10.1111/j.1348-0421.2009.00172.x}, pmid = {19954456}, issn = {0385-5600}, mesh = {Amino Acid Sequence ; Animals ; Antibodies/*blood ; B-Lymphocytes/immunology ; Bacterial Proteins/genetics/immunology ; Brugia malayi/*microbiology ; Cloning, Molecular ; DNA, Protozoan/genetics ; Elephantiasis, Filarial/blood/immunology/microbiology ; Epitopes/analysis/chemistry/immunology ; HLA-D Antigens/immunology ; Helminth Proteins/genetics ; Humans ; Immunoglobulin E/blood ; Immunoglobulin G/blood ; Membrane Proteins/genetics/immunology ; Polymerase Chain Reaction ; T-Lymphocytes/immunology ; Wolbachia/*immunology ; }, abstract = {Wolbachia surface protein (WSP), which is the most abundantly expressed protein of Wolbachia from the human filarial parasite Brugia malayi, was chosen for the present study. B-cell epitope prediction of the WSP protein sequence indicates a high antigenicity, surface probability and hydrophilicity by DNA STAR software analysis. ProPred analysis suggests the presence of HLA class II binding regions in the WSP protein that contribute to T-cell responses and isotype reactivity. In order to validate these findings, the gene coding for endosymbiont WSP was PCR-amplified from the genomic DNA of the human filarial parasite Brugia malayi and cloned in T-7 expression vector pRSET-A. Western blot and ELISA at the total IgG level with recombiant WSP indicated a significantly elevated reactivity in CP compared to MF, EN and NEN individuals. Isotype ELISA also suggested an elevated reactivity in CP patients at the IgG1 level. In contrast, WSP-specific IgG4 levels were found to be elevated in MF patients compared to CP and EN. Besides this, WSP-specific IgE levels indicated an elevated reactivity in CP and MF patients compared to normals. Observations from ELISA supported the in silico predictions that indicate the presence of B- and T-cell epitopes. Hence, a combinatorial approach of in silico predictions and wet-lab studies provides interesting insights into the role of Wolbachia proteins in filarial pathogenesis.}, }
@article {pmid19949823, year = {2010}, author = {Baumeister, S and Winterberg, M and Przyborski, JM and Lingelbach, K}, title = {The malaria parasite Plasmodium falciparum: cell biological peculiarities and nutritional consequences.}, journal = {Protoplasma}, volume = {240}, number = {1-4}, pages = {3-12}, pmid = {19949823}, issn = {1615-6102}, mesh = {Animals ; Cell Compartmentation ; Cell Membrane Permeability ; Erythrocyte Membrane/metabolism ; Erythrocytes/metabolism/parasitology/ultrastructure ; Host-Parasite Interactions/physiology ; Humans ; Malaria, Falciparum/blood/parasitology ; Models, Biological ; Organelles/metabolism ; Plasmodium falciparum/growth &amp; development/*pathogenicity/*physiology ; Vacuoles/parasitology ; }, abstract = {Apicomplexan parasites obligatorily invade and multiply within eukaryotic cells. Phylogenetically, they are related to a group of algae which, during their evolution, have acquired a secondary endosymbiont. This organelle, which in the parasite is called the apicoplast, is highly reduced compared to the endosymbionts of algae, but still contains many plant-specific biosynthetic pathways. The malaria parasite Plasmodium falciparum infects mammalian erythrocytes which are devoid of intracellular compartments and which largely lack biosynthetic pathways. Despite the limited resources of nutrition, the parasite grows and generates up to 32 merozoites which are the infectious stages of the complex life cycle. A large part of the intra-erythrocytic development takes place in the so-called parasitophorous vacuole, a compartment which forms an interface between the parasite and the cytoplasm of the host cell. In the course of parasite growth, the host cell undergoes dramatic alterations which on one hand contribute directly to the symptoms of severe malaria and which, on the other hand, are also required for parasite survival. Some of these alterations facilitate the acquisition of nutrients from the extracellular environment which are not provided by the host cell. Here, we describe the cell biologically unique interactions between an intracellular eukaryotic pathogen and its metabolically highly reduced host cell. We further discuss current models to explain the appearance of pathogen-induced novel physiological properties in a host cell which has lost its genetic programme.}, }
@article {pmid19948801, year = {2010}, author = {Vahling, CM and Duan, Y and Lin, H}, title = {Characterization of an ATP translocase identified in the destructive plant pathogen "Candidatus Liberibacter asiaticus".}, journal = {Journal of bacteriology}, volume = {192}, number = {3}, pages = {834-840}, pmid = {19948801}, issn = {1098-5530}, mesh = {Adenosine Diphosphate/metabolism ; Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Bacterial Proteins/genetics/*metabolism ; Computational Biology ; Mitochondrial ADP, ATP Translocases/genetics/*physiology ; Models, Biological ; Molecular Sequence Data ; Plant Diseases/*microbiology ; Rhizobiaceae/*enzymology ; Sequence Homology, Amino Acid ; }, abstract = {ATP/ADP translocases transport ATP across a lipid bilayer, which is normally impermeable to this molecule due to its size and charge. These transport proteins appear to be unique to mitochondria, plant plastids, and obligate intracellular bacteria. All bacterial ATP/ADP translocases characterized thus far have been found in endosymbionts of protozoa or pathogens of higher-order animals, including humans. A putative ATP/ADP translocase was uncovered during the genomic sequencing of the intracellular plant pathogen "Candidatus Liberibacter asiaticus," the causal agent of citrus huanglongbing. Bioinformatic analysis of the protein revealed 12 transmembrane helices and predicted an isoelectric point of 9.4, both of which are characteristic of this family of proteins. The "Ca. Liberibacter asiaticus" gene (nttA) encoding the translocase was subsequently expressed in Escherichia coli and shown to enable E. coli to import ATP directly into the cell. Competition assays with the heterologous E. coli system demonstrated that the translocase was highly specific for ATP and ADP but that other nucleotides, if present in high concentrations, could also be taken up and/or block the ability of the translocase to import ATP. In addition, a protein homologous to NttA was identified in "Ca. Liberibacter solanacearum," the bacterium associated with potato zebra chip disease. This is the first reported characterization of an ATP translocase from "Ca. Liberibacter asiaticus," indicating that some intracellular bacteria of plants also have the potential to import ATP directly from their environment.}, }
@article {pmid23129882, year = {2009}, author = {Paily, KP and Hoti, SL and Das, PK}, title = {A review of the complexity of biology of lymphatic filarial parasites.}, journal = {Journal of parasitic diseases : official organ of the Indian Society for Parasitology}, volume = {33}, number = {1-2}, pages = {3-12}, pmid = {23129882}, issn = {0971-7196}, abstract = {There are about five more common, including Wuchereria bancrofti and Brugia malayi, and four less common filarial parasites infecting human. Genetic analysis of W. bancrofti populations in India showed that two strains of the species are prevalent in the country. The adult filarial parasites are tissue specific in the human host and their embryonic stage, called microfilariae (mf), are found in the blood or skin of the host, depending upon the species of the parasite. Three genetically determined physiological races exist in W. bancrofti and B. malayi, based on the microfilarial periodicity. They are the nocturnally periodic, nocturnally subperiodic and diurnally subperiodic forms. The susceptibility of a mosquito species to filarial infection depends on various factors, which could be genetic, physiological or physical. Survival analysis of Culex quinquefasciatus infected with W. bancrofti showed that the parasite load in the mosquito is a risk factor of vector survival. The extrinsic life cycle of the parasite is initiated when the mf are ingested by a mosquito vector during feeding on the host blood. On maturity, most of the infective L3 stage larvae migrate to the head and proboscis of the mosquito to get transmitted to the mammalian host during subsequent feeding. They develop to the adult L5 stage and the period of development and the longevity of the parasites varies according to the species of the nematode and the mammalian host. The rate of production of mf by the adult female was found to be stable at least for a period of five years. The life span of the mf has some influence on the dynamics of transmission of filariasis. Recent studies show that the endosymbiont, Wolbachia, plays an important role in the survival of filarial parasites. The possibility of in vitro and in vivo culture of filarial parasites is also reviewed.}, }
@article {pmid19942312, year = {2010}, author = {Rohm, B and Scherlach, K and Möbius, N and Partida-Martinez, LP and Hertweck, C}, title = {Toxin production by bacterial endosymbionts of a Rhizopus microsporus strain used for tempe/sufu processing.}, journal = {International journal of food microbiology}, volume = {136}, number = {3}, pages = {368-371}, doi = {10.1016/j.ijfoodmicro.2009.10.010}, pmid = {19942312}, issn = {1879-3460}, mesh = {Burkholderia/growth &amp; development/*metabolism ; Fermentation ; *Food Microbiology ; Macrolides/metabolism ; Mycotoxins/*metabolism ; Rhizopus/*growth &amp; development/metabolism ; Soybeans/*microbiology ; Symbiosis ; }, abstract = {Mould fungi are not only well known for food spoilage through toxin formation but also for the production of fermented foods. In Asian countries, the fermentation of soy beans and tofu for tempe and sufu production with various Rhizopus strains is widespread. Here we report the finding of toxinogenic bacteria in a starter culture used for sufu production. By means of metabolic profiling of the fungus under standard conditions for tempe and sufu production, we found that toxins of the rhizoxin complex are produced in critical amounts. Considering that rhizoxins are severe toxins with strong antimitotic activity it is important to notice that our findings uncover a health-threatening symbiosis in food processing. A simple PCR method for detecting toxinogenic endofungal bacteria in starter cultures is proposed.}, }
@article {pmid19940933, year = {2009}, author = {Kölsch, G and Matz-Grund, C and Pedersen, BV}, title = {Ultrastructural and molecular characterization of endosymbionts of the reed beetle genus Macroplea (Chrysomelidae, Donaciinae), and proposal of "Candidatus Macropleicola appendiculatae" and "Candidatus Macropleicola muticae".}, journal = {Canadian journal of microbiology}, volume = {55}, number = {11}, pages = {1250-1260}, doi = {10.1139/w09-085}, pmid = {19940933}, issn = {1480-3275}, mesh = {Animals ; Coleoptera/*microbiology/physiology ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal/genetics ; Gammaproteobacteria/classification/genetics/physiology/*ultrastructure ; In Situ Hybridization, Fluorescence ; Malpighian Tubules/microbiology ; Microscopy, Electron, Transmission ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Intracellular bacterial symbionts are known from various insect groups, particularly from those feeding on unbalanced diets, where the bacteria provide essential nutrients to the host. In the case of reed beetles (Coleoptera: Chrysomelidae, Donaciinae), however, the endosymbionts appear to be associated with specialized "glands" that secrete a material used for the beetles' unusual water-tight cocoon. These glands were discovered over a century ago, but the bacteria they contain have yet to be characterized and placed in a phylogenetic context. Here, we describe the ultrastructure of two endosymbiotic species ("Candidatus Macropleicola appendiculatae" and "Candidatus Macropleicola muticae") that reside in cells of the Malpighian tubules of the reed beetle species Macroplea appendiculata and Macroplea mutica, respectively. Fluorescent in situ hybridization using oligonucleotides targeting the 16S rRNA gene specific to Macroplea symbionts verified the localization of the symbionts in these organs. Phylogenetic analysis of 16S rRNA placed "Candidatus Macropleicola" in a clade of typically endosymbiotic Enterobacteriaceae (gamma-proteobacteria). Finally, we discuss the evidence available for the hypothesis that the beetle larvae use a secretion produced by the bacteria for the formation of an underwater cocoon.}, }
@article {pmid19940927, year = {2009}, author = {Hakoyama, T and Niimi, K and Watanabe, H and Tabata, R and Matsubara, J and Sato, S and Nakamura, Y and Tabata, S and Jichun, L and Matsumoto, T and Tatsumi, K and Nomura, M and Tajima, S and Ishizaka, M and Yano, K and Imaizumi-Anraku, H and Kawaguchi, M and Kouchi, H and Suganuma, N}, title = {Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen fixation.}, journal = {Nature}, volume = {462}, number = {7272}, pages = {514-517}, pmid = {19940927}, issn = {1476-4687}, mesh = {Azotobacter vinelandii ; Gene Expression Regulation, Plant ; *Genes, Bacterial ; Genes, Plant/genetics ; Genetic Complementation Test ; Genome, Plant/*genetics ; Ketoglutaric Acids/metabolism ; Lotus/enzymology/*genetics/*metabolism ; Molecular Sequence Data ; Mutation/genetics ; Nitrogen Fixation/*genetics ; Oxo-Acid-Lyases/deficiency/genetics/metabolism ; Plant Proteins/genetics/metabolism ; Rhizobium/genetics/*metabolism ; Saccharomyces cerevisiae/enzymology/genetics ; Symbiosis/*genetics ; Tricarboxylic Acids/metabolism ; }, abstract = {Homocitrate is a component of the iron-molybdenum cofactor in nitrogenase, where nitrogen fixation occurs. NifV, which encodes homocitrate synthase (HCS), has been identified from various diazotrophs but is not present in most rhizobial species that perform efficient nitrogen fixation only in symbiotic association with legumes. Here we show that the FEN1 gene of a model legume, Lotus japonicus, overcomes the lack of NifV in rhizobia for symbiotic nitrogen fixation. A Fix(-) (non-fixing) plant mutant, fen1, forms morphologically normal but ineffective nodules. The causal gene, FEN1, was shown to encode HCS by its ability to complement a HCS-defective mutant of Saccharomyces cerevisiae. Homocitrate was present abundantly in wild-type nodules but was absent from ineffective fen1 nodules. Inoculation with Mesorhizobium loti carrying FEN1 or Azotobacter vinelandii NifV rescued the defect in nitrogen-fixing activity of the fen1 nodules. Exogenous supply of homocitrate also recovered the nitrogen-fixing activity of the fen1 nodules through de novo nitrogenase synthesis in the rhizobial bacteroids. These results indicate that homocitrate derived from the host plant cells is essential for the efficient and continuing synthesis of the nitrogenase system in endosymbionts, and thus provide a molecular basis for the complementary and indispensable partnership between legumes and rhizobia in symbiotic nitrogen fixation.}, }
@article {pmid19934219, year = {2009}, author = {Albertson, R and Casper-Lindley, C and Cao, J and Tram, U and Sullivan, W}, title = {Symmetric and asymmetric mitotic segregation patterns influence Wolbachia distribution in host somatic tissue.}, journal = {Journal of cell science}, volume = {122}, number = {Pt 24}, pages = {4570-4583}, pmid = {19934219}, issn = {1477-9137}, support = {5R01GM046409/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Brain/microbiology ; Cell Division ; Centrosome/microbiology/physiology ; Drosophila melanogaster/embryology/*microbiology/*physiology ; Microtubules/microbiology/physiology ; *Mitosis ; Organ Specificity ; Wolbachia/*physiology ; }, abstract = {Wolbachia are maternally inherited bacterial endosymbionts that occupy many but not all tissues of adult insects. During the initial mitotic divisions in Drosophila embryogenesis, Wolbachia exhibit a symmetric pattern of segregation. Wolbachia undergo microtubule-dependent and cell-cycle-regulated movement between centrosomes. Symmetric segregation occurs during late anaphase when Wolbachia cluster around duplicated and separating centrosomes. This centrosome association is microtubule-dependent and promotes an even Wolbachia distribution throughout the host embryo. By contrast, during the later embryonic and larval neuroblast divisions, Wolbachia segregate asymmetrically with the apical self-renewing neuroblast. During these polarized asymmetric neuroblast divisions, Wolbachia colocalize with the apical centrosome and apically localized Par complex. This localization depends on microtubules, but not the cortical actin-based cytoskeleton. We also found that Wolbachia concentrate in specific regions of the adult brain, which might be a direct consequence of the asymmetric Wolbachia segregation in the earlier neuroblast divisions. Finally, we demonstrate that the fidelity of asymmetric segregation to the self-renewing neuroblast is lower in the virulent Popcorn strain of Wolbachia.}, }
@article {pmid19923192, year = {2010}, author = {Castillo, DM and Pawlowska, TE}, title = {Molecular evolution in bacterial endosymbionts of fungi.}, journal = {Molecular biology and evolution}, volume = {27}, number = {3}, pages = {622-636}, doi = {10.1093/molbev/msp280}, pmid = {19923192}, issn = {1537-1719}, mesh = {Burkholderia/*genetics ; DNA, Bacterial/*genetics ; *Evolution, Molecular ; Genes, rRNA/*genetics ; Glomeromycota/*genetics ; Mutation ; Phylogeny ; Poisson Distribution ; RNA Stability ; Rhizopus/*genetics ; Symbiosis/*genetics ; Thermodynamics ; }, abstract = {The prediction that progressive coupling of host and symbiont metabolic and reproductive interests leads to reduced mixing of symbiont lineages has been verified extensively in maternally transmitted bacterial endosymbionts of insects. To test whether this prediction is also applicable to associations of bacteria with fungi, we explored patterns of molecular evolution in two lineages of mutualistic endosymbionts of fungi: the Burkholderia endosymbionts of Rhizopus microsporus (Mucormycotina) and Candidatus Glomeribacter gigasporarum endosymbionts of arbuscular mycorrhizal fungi (Glomeromycota). We compared these two lineages with the closely related Candidatus Tremblaya princeps endosymbionts of mealybugs (Hemiptera, Coccoidea, Pseudococcidae) and to free-living Burkholderia species. To make inferences about the life histories of the endosymbionts, we relied on the empirically validated predictions of the nearly neutral theory of molecular evolution that a reduction of the effective population size increases the rate of fixation of slightly deleterious mutations. Our analyses showed that the slightly deleterious mutation accumulation patterns in the Burkholderia endosymbionts of Rhizopus were nearly indistinguishable from those in their free-living relatives. In contrast, Ca. Glomeribacter showed unique patterns of molecular evolution that differentiated them from both the Burkholderia endosymbionts of Rhizopus and from the Ca. Tremblaya endosymbionts of insects. These findings imply that reduced mixing of symbiont lineages is not a universal feature of symbioses between fungi and endocellular bacteria.}, }
@article {pmid19922288, year = {2010}, author = {Yancey, PH and Heppenstall, M and Ly, S and Andrell, RM and Gates, RD and Carter, VL and Hagedorn, M}, title = {Betaines and dimethylsulfoniopropionate as major osmolytes in cnidaria with endosymbiotic dinoflagellates.}, journal = {Physiological and biochemical zoology : PBZ}, volume = {83}, number = {1}, pages = {167-173}, doi = {10.1086/644625}, pmid = {19922288}, issn = {1537-5293}, mesh = {Animals ; Betaine/*analysis ; Chromatography, High Pressure Liquid ; Cnidaria/*chemistry/physiology ; Dinoflagellida/*chemistry/physiology ; Hawaii ; Osmolar Concentration ; Sulfonium Compounds/*analysis ; Symbiosis/physiology ; }, abstract = {Most marine invertebrates and algae are osmoconformers whose cells accumulate organic osmolytes that provide half or more of cellular osmotic pressure. These solutes are primarily free amino acids and glycine betaine in most invertebrates and small carbohydrates and dimethylsulfoniopropionate (DMSP) in many algae. Corals with endosymbiotic dinoflagellates (Symbiodinium spp.) have been reported to obtain from the symbionts potential organic osmolytes such as glycerol, amino acids, and DMSP. However, corals and their endosymbionts have not been fully analyzed for osmolytes. We quantified small carbohydrates, free amino acids, methylamines, and DMSP in tissues of the corals Fungia scutaria, Pocillopora damicornis, Pocillopora meandrina, Montipora capitata, Porites compressa, and Porites lobata (all with symbionts) plus Tubastrea aurea (asymbiotic) from Kaneohe Bay, Oahu (Hawaii). Glycine betaine, at 33-69 mmol/kg wet mass, was found to constitute 90% or more of the measured organic solutes in all except the Porites species. Those were dominated by proline betaine and dimethyltaurine. DMSP was found at 0.5-3 mmol/kg in all species with endosymbionts. Freshly isolated Symbiodinium from Fungia, P. damicornis, and P. compressa were also analyzed. DMSP and glycine betaine dominated in the first two; Porites endosymbionts had DMSP, proline betaine, and dimethyltaurine. In all specimens, glycerol and glucose were detected by high-performance liquid chromatography only at 0-1 mmol/kg wet mass. An enzymatic assay for glycerol plus glycerol 3-phosphate and dihydroxyacetone phosphate yielded 1-10 mmol/kg. Cassiopeia andromeda (upside-down jelly; Scyphozoan) and Aiptasia puchella (solitary anemone; Anthozoan) were also analyzed; both have endosymbiotic dinoflagellates. In both, glycine betaine, taurine, and DMSP were the dominant osmolytes. In summary, methylated osmolytes dominate in many Cnidaria; in those with algal symbionts, host and symbiont have similar methylated amino acids, as do congeners. However, little glycerol was present as an osmolyte and was probably metabolized before it could accumulate.}, }
@article {pmid19921698, year = {2009}, author = {Elias, M and Archibald, JM}, title = {Sizing up the genomic footprint of endosymbiosis.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {31}, number = {12}, pages = {1273-1279}, doi = {10.1002/bies.200900117}, pmid = {19921698}, issn = {1521-1878}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Biological Evolution ; Diatoms/genetics ; Eukaryota/genetics ; Genome/*genetics ; Symbiosis/*genetics ; }, abstract = {A flurry of recent publications have challenged consensus views on the tempo and mode of plastid (chloroplast) evolution in eukaryotes and, more generally, the impact of endosymbiosis in the evolution of the nuclear genome. Endosymbiont-to-nucleus gene transfer is an essential component of the transition from endosymbiont to organelle, but the sheer diversity of algal-derived genes in photosynthetic organisms such as diatoms, as well as the existence of genes of putative plastid ancestry in the nuclear genomes of plastid-lacking eukaryotes such as ciliates and choanoflagellates, defy simple explanation. Collectively, these papers underscore the power of comparative genomics and, at the same time, reveal how little we know with certainty about the earliest stages of the evolution of photosynthetic eukaryotes.}, }
@article {pmid19916630, year = {2010}, author = {Michalski, ML and Bain, O and Fischer, K and Fischer, PU and Kumar, S and Foster, JM}, title = {Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont.}, journal = {The Journal of parasitology}, volume = {96}, number = {2}, pages = {412-419}, doi = {10.1645/GE-2208.1}, pmid = {19916630}, issn = {1937-2345}, support = {R15 AI067295/AI/NIAID NIH HHS/United States ; 1R15AI067295-01A/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; DNA, Bacterial/chemistry ; DNA, Helminth/chemistry ; DNA, Ribosomal/chemistry ; Dirofilaria/anatomy &amp; histology/*classification/genetics/microbiology ; Dirofilariasis/epidemiology/*parasitology ; Dogs ; Female ; Immunohistochemistry/veterinary ; Male ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/veterinary ; Prevalence ; RNA, Ribosomal, 5S/genetics ; Sequence Alignment/veterinary ; *Symbiosis ; Ursidae/*parasitology ; Wisconsin/epidemiology ; Wolbachia/classification/genetics/*physiology ; }, abstract = {Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus Pallas, 1780) that is vectored by black flies (Simuliidae) in many parts of the United States. In northwestern Wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). Unsheathed blood microfilariae from Wisconsin bears possess characters consistent with the original description of D. ursi, as do adult worms observed histologically and grossly. Immunohistochemistry was used to identify the Wolbachia endosymbiont in the hypodermis and lateral cords of an adult female D. ursi. Amplification of wsp, gatB, coxA, fbpA, and ftsZ bacterial sequences from parasite DNA confirmed the presence of Wolbachia, and molecular phylogenetic analysis of the Wolbachia ftsZ gene groups the endosymbiont with Wolbachia from D. immitis and D. repens. Phylogenetic analysis of D. ursi 5s rDNA sequence confirms the morphological observations grouping this parasite as a member of Dirofilaria, and within the Dirofilaria - Onchocerca clade of filarial nematodes. This is the first report of Wolbachia characterization and molecular phylogeny information for D. ursi.}, }
@article {pmid19911043, year = {2009}, author = {López-Sánchez, MJ and Neef, A and Peretó, J and Patiño-Navarrete, R and Pignatelli, M and Latorre, A and Moya, A}, title = {Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.}, journal = {PLoS genetics}, volume = {5}, number = {11}, pages = {e1000721}, pmid = {19911043}, issn = {1553-7404}, mesh = {Amino Acids/metabolism ; Ammonia/metabolism ; Animals ; Ants/microbiology ; Bacteroidetes/*genetics ; Cockroaches/*microbiology ; Enterobacteriaceae/genetics ; *Evolution, Molecular ; Genome, Bacterial ; Genomics/methods ; Host-Pathogen Interactions/genetics ; Metabolic Networks and Pathways ; Nitrogen/*metabolism ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state.}, }
@article {pmid19910386, year = {2010}, author = {Suzuki, K and Miyagishima, SY}, title = {Eukaryotic and eubacterial contributions to the establishment of plastid proteome estimated by large-scale phylogenetic analyses.}, journal = {Molecular biology and evolution}, volume = {27}, number = {3}, pages = {581-590}, doi = {10.1093/molbev/msp273}, pmid = {19910386}, issn = {1537-1719}, mesh = {Algal Proteins/classification/*genetics ; Arabidopsis/genetics ; Bacteria/genetics ; Bacterial Proteins/classification/genetics ; Cell Nucleus ; Cyanobacteria/genetics ; Evolution, Molecular ; Gene Transfer, Horizontal ; *Phylogeny ; Plant Proteins/classification/*genetics ; Plastids/*genetics ; Proteome/*genetics ; Rhodophyta/genetics ; Symbiosis ; }, abstract = {Plastids including chloroplasts arose from a cyanobacterial endosymbiont and have retained their own genome, but the size has been reduced to less than one-tenth of the original bacterial genome. Over time, genes essential to plastid function have been transferred from the ancestral plastid genome to the nucleus, and the gene products are now targeted into the plastid from the host cytosol. However, phylogenetic analyses have suggested that the functions of certain original proteins encoded by the endosymbiont genome have been replaced by nucleus-encoded proteins of noncyanobacterial origin and that several proteins have been newly added to maintain and control plastids. In order to evaluate the rate and origin of noncyanobacterial proteins that have contributed to the establishment of the plastid proteome, we performed phylogenetic analyses of plastid-targeted proteins that are shared by the red alga Cyanidioschyzon merolae (455 proteins) and the Viridiplanta Arabidopsis thaliana (744 proteins). Our results show that approximately 40% of the plastid proteome common to red algae and green plants originated from genes of both the ancestral eukaryotic host and various lineages of bacteria (eubacteria) other than cyanobacteria. The replacement or addition of components was frequently observed for most of the plastid functions except for the light reaction of photosynthesis and the translation and degradation of proteins in the plastid. These results suggest that a considerable amount of bacterial metagenomic material, as well as the genomes of the host and the endosymbiont, has contributed to the establishment of the plastid before the split of the red and green algae.}, }
@article {pmid19909925, year = {2009}, author = {Brinza, L and Viñuelas, J and Cottret, L and Calevro, F and Rahbé, Y and Febvay, G and Duport, G and Colella, S and Rabatel, A and Gautier, C and Fayard, JM and Sagot, MF and Charles, H}, title = {Systemic analysis of the symbiotic function of Buchnera aphidicola, the primary endosymbiont of the pea aphid Acyrthosiphon pisum.}, journal = {Comptes rendus biologies}, volume = {332}, number = {11}, pages = {1034-1049}, doi = {10.1016/j.crvi.2009.09.007}, pmid = {19909925}, issn = {1768-3238}, mesh = {Amino Acids/metabolism ; Animals ; Aphids/cytology/*microbiology/physiology ; Bacterial Proteins/genetics/physiology ; Buchnera/classification/genetics/*physiology ; Chromosomes, Bacterial/genetics ; Evolution, Molecular ; Gene Expression Regulation, Bacterial ; Gene Regulatory Networks ; Genes, Bacterial ; Genetic Drift ; *Genome, Bacterial ; *Genomics ; Metabolic Networks and Pathways/genetics ; Peas/*parasitology ; Phylogeny ; Symbiosis/genetics/*physiology ; }, abstract = {Buchnera aphidicola is the primary obligate intracellular symbiont of most aphid species. B. aphidicola and aphids have been evolving in parallel since their association started, about 150 Myr ago. Both partners have lost their autonomy, and aphid diversification has been confined to smaller ecological niches by this co-evolution. B. aphidicola has undergone major genomic and biochemical changes as a result of adapting to intracellular life. Several genomes of B. aphidicola from different aphid species have been sequenced in the last decade, making it possible to carry out analyses and comparative studies using system-level in silico methods. This review attempts to provide a systemic description of the symbiotic function of aphid endosymbionts, particularly of B. aphidicola from the pea aphid Acyrthosiphon pisum, by analyzing their structural genomic properties, as well as their genetic and metabolic networks.}, }
@article {pmid19907699, year = {2009}, author = {Nakanishi, H and Suzuki, K and Kabeya, Y and Okazaki, K and Miyagishima, SY}, title = {Conservation and differences of the Min system in the chloroplast and bacterial division site placement.}, journal = {Communicative &amp; integrative biology}, volume = {2}, number = {5}, pages = {400-402}, pmid = {19907699}, issn = {1942-0889}, abstract = {Chloroplasts are descended from a cyanobacterial endosymbiont and divide by binary fission. Reminiscent of the process in their bacterial ancestor, chloroplast division involves a part of cyanobacteria-derived division machineries in addition to those acquired during chloroplast evolution.1,2 In both bacterial and chloroplast division, formation of the FtsZ ring at the mid position is required for subsequent constriction and fission at the mid division site.1-4 As in bacteria, positioning of the FtsZ ring at the mid-chloroplast is mediated by the Min system.1,2 Recently, we identified the MCD1 protein, a plant-specific component of the Min system in Arabidopsis thaliana chloroplasts.5 Unlike other division components that have been acquired after endosymbiosis and function outside of the chloroplasts (i.e., in/on the outer envelope membrane),6-9 MCD1 functions inside the chloroplast. Since we already discussed about the function and significance of MCD1 as a division component of plant origin,5 here we focus on and discuss about the diversity and evolution of the Min system.}, }
@article {pmid19906794, year = {2010}, author = {Chafee, ME and Funk, DJ and Harrison, RG and Bordenstein, SR}, title = {Lateral phage transfer in obligate intracellular bacteria (wolbachia): verification from natural populations.}, journal = {Molecular biology and evolution}, volume = {27}, number = {3}, pages = {501-505}, pmid = {19906794}, issn = {1537-1719}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; R01 GM085163-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteriophages/*genetics ; Bayes Theorem ; Coleoptera/genetics/*microbiology/virology ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Gryllidae/genetics/*microbiology/virology ; Interspersed Repetitive Sequences ; Phylogeny ; Wolbachia/*genetics/virology ; }, abstract = {Lateral transfer of mobile DNA is a hallmark of bacteria with a free-living replicative stage; however, its significance in obligate intracellular bacteria and other heritable endosymbionts remains controversial. Comparative sequence analyses from laboratory stocks infected with Wolbachia pipientis provide some of the most compelling evidence that bacteriophage WO-B transfers laterally between infections of the same insect host. Lateral transfer between coinfections, however, has been evaluated neither in natural populations nor between closely related Wolbachia strains. Here, we analyze bacterial and phage genes from two pairs of natural sympatric field isolates, of Gryllus pennsylvanicus field crickets and of Neochlamisus bebbianae leaf beetles, to demonstrate WO-B transfers between supergroup B Wolbachia. N. bebbianae revealed the highest number of phage haplotypes yet recorded, hinting that lab lines could underestimate phage haplotype variation and lateral transfer. Finally, using the approximate age of insect host species as the maximum available time for phage transfer between host-associated bacteria, we very conservatively estimate phage WO-B transfer to occur at least once every 0-5.4 My within a host species. Increasing discoveries of mobile elements, intragenic recombination, and bacterial coinfections in host-switching obligate intracellular bacteria specify that mobile element transfer is common in these species.}, }
@article {pmid19903219, year = {2010}, author = {Kuijper, B and Pen, I}, title = {The evolution of haplodiploidy by male-killing endosymbionts: importance of population structure and endosymbiont mutualisms.}, journal = {Journal of evolutionary biology}, volume = {23}, number = {1}, pages = {40-52}, doi = {10.1111/j.1420-9101.2009.01854.x}, pmid = {19903219}, issn = {1420-9101}, mesh = {Animals ; Computer Simulation ; *Diploidy ; *Evolution, Molecular ; Female ; *Haploidy ; Male ; *Models, Genetic ; Sex Ratio ; Symbiosis ; }, abstract = {Haplodiploid inheritance systems, characterized by male transmission of only their maternally inherited genomic elements, have evolved more than 20 times within the animal kingdom. A number of theoretical studies have argued that infection with certain male-killing endosymbionts can potentially lead to the evolution of haplodiploidy. By explicitly investigating the coevolutionary dynamics between host and endosymbiont, we show that the assumptions of current models cannot explain the evolution of haplodiploidy very well, as the endosymbiont will often go extinct in the long term. Here, we provide two additional mechanisms that can explain the stable evolution of haplodiploidy by male-killing endosymbionts. First of all, a spatially structured population can facilitate the long-term persistence of haplodiploidy, but this applies only when levels of inbreeding are very high. By contrast, endosymbionts that are mutualistic with their hosts provide a much more general and promising route to the stable evolution of haplodiploidy. This model is the first to provide a formal explanation of the supposed association between the evolution of haplodiploidy and the highly inbred lifestyles of some ancestors, while it also provides a hypothesis for the evolution of haplodiploidy in more outbred ancestors.}, }
@article {pmid19900566, year = {2010}, author = {Kölsch, G and Pedersen, BV}, title = {Can the tight co-speciation between reed beetles (Col., Chrysomelidae, Donaciinae) and their bacterial endosymbionts, which provide cocoon material, clarify the deeper phylogeny of the hosts?.}, journal = {Molecular phylogenetics and evolution}, volume = {54}, number = {3}, pages = {810-821}, doi = {10.1016/j.ympev.2009.10.038}, pmid = {19900566}, issn = {1095-9513}, mesh = {Animals ; Bacteria/classification/*genetics ; Coleoptera/classification/*genetics/microbiology ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; *Evolution, Molecular ; Genes, Insect ; Genetic Speciation ; Models, Genetic ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {In most mutualistic symbioses of insects and intracellular bacteria, the endosymbionts provide additional nutrients to a host that feeds on an unbalanced diet. A strictly vertical transmission leads to co-speciation between the two partners. We have investigated an insect-bacteria relationship with a non-nutritional basis. The reed beetles (Donaciinae) harbor bacteria that produce a secretion used by the larvae for building a cocoon for pupation in mud underwater. The 16S rRNA of the bacteria and the cytochrome c oxidase I and elongation factor 1alpha of the beetles have been partially sequenced. The bacterial and the host phylogeny were highly congruent. Larger taxonomic units (genera) and host species groups/pairs have been recovered in the bacterial phylogeny. The symbiont data still cannot clarify the hitherto unresolved deeper phylogeny of the hosts, which is interpreted as a sign of rapid adaptive radiation of the reed beetles soon after their origin. The rate of sequence evolution among/within host species is discussed.}, }
@article {pmid19891414, year = {2009}, author = {Vaĭsman, NIa and Ilinskiĭ, IuIu and Golubovskiĭ, MD}, title = {[Population genetic analysis of Drosophila melanogaster longevity: similar effects of endosymbiont Wolbachia and tumor suppressor lgl under conditions of temperature stress].}, journal = {Zhurnal obshchei biologii}, volume = {70}, number = {5}, pages = {438-447}, pmid = {19891414}, issn = {0044-4596}, mesh = {Animals ; Drosophila Proteins/*genetics ; Drosophila melanogaster/*genetics/growth &amp; development/microbiology ; *Genetics, Population ; Longevity/*genetics ; Stress, Physiological/*genetics ; *Symbiosis ; Temperature ; Tumor Suppressor Proteins/*genetics ; Wolbachia/*growth &amp; development ; }, abstract = {Before, it has been shown that keeping of Drosophila wild populations under temperature stress leads to prevalence of deletion alleles of tumor suppressor lgl, and higher survival of heterozygous lgl(-)/+ females descendants (haploadaptivity). On the other hand, recent investigations have demonstrated that an additional dose of lgl gene in transgenic males has inadaptive effect--cytoplasmic incompatibility, caused by the gene, is similar to the effect caused by the widespread endosymbiont Wolbachia. Both triple dose of lgl and Wolbachia infection invoke hyperexpression of some cytoskeleton proteins which leads to sperm defects and sterility of hybrid zygotes. Proceeding from this similarity, we studied the Wolbachia effect on Drosophila longevity (LG) depending on the bacteria strain, host genotype and sex, and maintenance temperature. With use of tetracycline, six Wolbachia-free lines were produced, analogical to the infected wild ones. After analyzing LG under optimal temperature conditions (25 degrees C), the lines were subdivided into three genotypic groups, differing by the LG, mortality dynamics, and type of sexual dimorphism. Under conditions of temperature stress (16 degrees C and 29 degrees C) the lines ranks with respect to LG remained as they were, though the distinctions between them were smoothed out. In other words, the effect of the genes regulating LG parameters depends on maintenance conditions. The research also revealed sharp genetic distinctions between LG parameters of two standard laboratory lines Canton and Oregon that were taken as the control. These distinctions do not disappear in crossings. In the infected lines, in seven experiments out of thirty (20% of cases) significant sex-specific influence of Wolbachia on LG was revealed, namely, in two combinations at the optimal temperature 25 degrees C, and in five combinations at stress temperatures. Under the optimal temperature conditions the endosymbiont shortened its host LG in both cases, while at stress temperatures, in four cases out of five, it extended the host LG. Females of the long-living line Bi90 (wMel) from a mountain Kirghiz population appeared to be especially sensitive to the infection carriage--their endosymbiont-caused LG extension was observed both under cold and heat stresses. This result is analogues to the effect of diminishing the oncosupressor lgl dose. In both cases LG extends only under temperature stress, and this positive effect is sex-specific.}, }
@article {pmid19888992, year = {2010}, author = {Maralikova, B and Ali, V and Nakada-Tsukui, K and Nozaki, T and van der Giezen, M and Henze, K and Tovar, J}, title = {Bacterial-type oxygen detoxification and iron-sulfur cluster assembly in amoebal relict mitochondria.}, journal = {Cellular microbiology}, volume = {12}, number = {3}, pages = {331-342}, doi = {10.1111/j.1462-5822.2009.01397.x}, pmid = {19888992}, issn = {1462-5822}, support = {BB/C507145/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/C507145/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacterial Proteins/*metabolism ; Entamoeba histolytica/*metabolism ; Hemerythrin/metabolism ; Iron/*metabolism ; Microscopy, Fluorescence ; Microscopy, Immunoelectron ; Organelles/*metabolism ; Oxygen/*antagonists &amp; inhibitors ; Peroxidase/metabolism ; Rubredoxins/metabolism ; Sulfur/*metabolism ; }, abstract = {The assembly of vital reactive iron-sulfur (Fe-S) cofactors in eukaryotes is mediated by proteins inherited from the original mitochondrial endosymbiont. Uniquely among eukaryotes, however, Entamoeba and Mastigamoeba lack such mitochondrial-type Fe-S cluster assembly proteins and possess instead an analogous bacterial-type system acquired by lateral gene transfer. Here we demonstrate, using immunomicroscopy and biochemical methods, that beyond their predicted cytosolic distribution the bacterial-type Fe-S cluster assembly proteins NifS and NifU have been recruited to function within the relict mitochondrial organelles (mitosomes) of Entamoeba histolytica. Both Nif proteins are 10-fold more concentrated within mitosomes compared with their cytosolic distribution suggesting that active Fe-S protein maturation occurs in these organelles. Quantitative immunoelectron microscopy showed that amoebal mitosomes are minute but highly abundant cellular structures that occupy up to 2% of the total cell volume. In addition, protein colocalization studies allowed identification of the amoebal hydroperoxide detoxification enzyme rubrerythrin as a mitosomal protein. This protein contains functional Fe-S centres and exhibits peroxidase activity in vitro. Our findings demonstrate the role of analogous protein replacement in mitochondrial organelle evolution and suggest that the relict mitochondrial organelles of Entamoeba are important sites of metabolic activity that function in Fe-S protein-mediated oxygen detoxification.}, }
@article {pmid19880743, year = {2009}, author = {Sabree, ZL and Kambhampati, S and Moran, NA}, title = {Nitrogen recycling and nutritional provisioning by Blattabacterium, the cockroach endosymbiont.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, number = {46}, pages = {19521-19526}, pmid = {19880743}, issn = {1091-6490}, support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; 2 K12 GM000708/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/biosynthesis/genetics ; Animals ; Bacteroidetes/classification/genetics/*metabolism ; Base Sequence ; *Gene Expression Regulation, Bacterial ; Genome, Bacterial ; Molecular Sequence Data ; Nitrogen/*metabolism ; Periplaneta/metabolism/*microbiology ; Phylogeny ; RNA Polymerase Sigma 54/genetics/metabolism ; *Symbiosis ; Uric Acid/metabolism ; }, abstract = {Nitrogen acquisition and assimilation is a primary concern of insects feeding on diets largely composed of plant material. Reclaiming nitrogen from waste products provides a rich reserve for this limited resource, provided that recycling mechanisms are in place. Cockroaches, unlike most terrestrial insects, excrete waste nitrogen within their fat bodies as uric acids, postulated to be a supplement when dietary nitrogen is limited. The fat bodies of most cockroaches are inhabited by Blattabacterium, which are vertically transmitted, Gram-negative bacteria that have been hypothesized to participate in uric acid degradation, nitrogen assimilation, and nutrient provisioning. We have sequenced completely the Blattabacterium genome from Periplaneta americana. Genomic analysis confirms that Blattabacterium is a member of the Flavobacteriales (Bacteroidetes), with its closest known relative being the endosymbiont Sulcia muelleri, which is found in many sap-feeding insects. Metabolic reconstruction indicates that it lacks recognizable uricolytic enzymes, but it can recycle nitrogen from urea and ammonia, which are uric acid degradation products, into glutamate, using urease and glutamate dehydrogenase. Subsequently, Blattabacterium can produce all of the essential amino acids, various vitamins, and other required compounds from a limited palette of metabolic substrates. The ancient association with Blattabacterium has allowed cockroaches to subsist successfully on nitrogen-poor diets and to exploit nitrogenous wastes, capabilities that are critical to the ecological range and global distribution of cockroach species.}, }
@article {pmid19880647, year = {2010}, author = {Toju, H and Hosokawa, T and Koga, R and Nikoh, N and Meng, XY and Kimura, N and Fukatsu, T}, title = {"Candidatus Curculioniphilus buchneri," a novel clade of bacterial endocellular symbionts from weevils of the genus Curculio.}, journal = {Applied and environmental microbiology}, volume = {76}, number = {1}, pages = {275-282}, pmid = {19880647}, issn = {1098-5336}, mesh = {Animals ; Bacterial Proteins/genetics ; Chaperonin 60/genetics ; Cluster Analysis ; Cytoplasm/microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Enterobacteriaceae/*classification/genetics/isolation &amp; purification/*physiology ; Female ; Gastrointestinal Tract/microbiology ; In Situ Hybridization ; Male ; Molecular Sequence Data ; Ovary/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Weevils/*microbiology ; }, abstract = {Here we investigated the bacterial endosymbionts of weevils of the genus Curculio. From all four species of Curculio weevils examined, a novel group of bacterial gene sequences were consistently identified. Molecular phylogenetic analyses demonstrated that the sequences formed a distinct clade in the Gammaproteobacteria, which was not related to previously known groups of weevil endosymbionts such as Nardonella spp. and Sodalis-allied symbionts. In situ hybridization revealed that the bacterium was intracellularly harbored in a bacteriome associated with larval midgut. In adult females, the bacterium was localized in the germalia at the tip of each overiole, suggesting vertical transmission via ovarial passage. Diagnostic PCR surveys detected high prevalence of the bacterial infection in natural host populations. Electron microscopy identified the reduced cell wall of the bacterial cells, and the bacterial genes exhibited AT-biased nucleotide composition and accelerated molecular evolution, which are suggestive of a long-lasting endosymbiotic association. On the basis of these results, we conclude that the novel endocellular bacteria represent the primary symbiont of Curculio weevils and proposed the designation "Candidatus Curculioniphilus buchneri." In addition to "Ca. Curculioniphilus," we identified Sodalis-allied gammaproteobacterial endosymbionts from the chestnut weevil, Curculio sikkimensis, which exhibited partial infection frequencies in host insect populations and neither AT-biased nucleotide composition nor accelerated molecular evolution. We suggest that such Sodalis-allied secondary symbionts in weevils might provide a potential source for symbiont replacements, as has occurred in an ancestor of Sitophilus grain weevils.}, }
@article {pmid19862011, year = {2010}, author = {Godfray, HC}, title = {An insect-endosymbiont conundrum.}, journal = {Heredity}, volume = {104}, number = {3}, pages = {237-238}, doi = {10.1038/hdy.2009.144}, pmid = {19862011}, issn = {1365-2540}, mesh = {Animals ; Bacteroidetes/genetics/*physiology ; Insecta/genetics/*microbiology/*physiology ; *Symbiosis ; }, }
@article {pmid19857482, year = {2010}, author = {Hagedorn, M and Carter, VL and Leong, JC and Kleinhans, FW}, title = {Physiology and cryosensitivity of coral endosymbiotic algae (Symbiodinium).}, journal = {Cryobiology}, volume = {60}, number = {2}, pages = {147-158}, doi = {10.1016/j.cryobiol.2009.10.005}, pmid = {19857482}, issn = {1090-2392}, mesh = {Animals ; Anthozoa/*microbiology ; Cell Membrane Permeability ; Conservation of Natural Resources ; *Cryopreservation/methods ; Cryoprotective Agents/pharmacokinetics/toxicity ; Deuterium Oxide ; Dinoflagellida/classification/drug effects/*physiology ; Glycerol/pharmacokinetics/toxicity ; Osmotic Pressure ; Species Specificity ; Symbiosis ; }, abstract = {Coral throughout the world are under threat. To save coral via cryopreservation methods, the Symbiodinium algae that live within many coral cells must also be considered. Coral juvenile must often take up these important cells from their surrounding water and when adult coral bleach, they lose their endosymbiotic algae and will die if they are not regained. The focus of this paper was to understand some of the cryo-physiology of the endosymbiotic algae, Symbiodinium, living within three species of Hawaiian coral, Fungia scutaria, Porites compressa and Pocillopora damicornis in Kaneohe Bay, Hawaii. Although cryopreservation of algae is common, the successful cryopreservation of these important coral endosymbionts is not common, and these species are often maintained in live serial cultures within stock centers worldwide. Freshly-extracted Symbiodinium were exposed to cryobiologically appropriate physiological stresses and their viability assessed with a Pulse Amplitude Fluorometer. Stresses included sensitivity to chilling temperatures, osmotic stress, and toxic effects of various concentrations and types of cryoprotectants (i.e., dimethyl sulfoxide, propylene glycol, glycerol and methanol). To determine the water and cryoprotectant permeabilities of Symbiodinium, uptake of radio-labeled glycerol and heavy water (D(2)O) were measured. The three different Symbiodinium subtypes studied demonstrated remarkable similarities in their morphology, sensitivity to cryoprotectants and permeability characteristics; however, they differed greatly in their sensitivity to hypo- and hyposmotic challenges and sensitivity to chilling, suggesting that standard slow freezing cryopreservation may not work well for all Symbiodinium. An appendix describes our H(2)O:D(2)O water exchange experiments and compares the diffusionally determined permeability with the two parameter model osmotic permeability.}, }
@article {pmid19851452, year = {2009}, author = {Kremer, N and Voronin, D and Charif, D and Mavingui, P and Mollereau, B and Vavre, F}, title = {Wolbachia interferes with ferritin expression and iron metabolism in insects.}, journal = {PLoS pathogens}, volume = {5}, number = {10}, pages = {e1000630}, pmid = {19851452}, issn = {1553-7374}, mesh = {Aedes/genetics/growth &amp; development/metabolism/microbiology ; Animals ; Base Sequence ; Chromosome Mapping ; Drosophila/genetics/growth &amp; development/metabolism/microbiology ; Female ; Ferritins/*genetics/metabolism ; Gene Expression Regulation ; Genetic Loci ; Host-Parasite Interactions/genetics ; Insecta/*genetics/growth &amp; development/*metabolism/microbiology ; Iron/*metabolism/pharmacology ; Molecular Sequence Data ; Nucleic Acid Conformation ; Rickettsiaceae Infections/genetics/metabolism ; Symbiosis/genetics ; Wasps/genetics/growth &amp; development/metabolism/microbiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia is an intracellular bacterium generally described as being a facultative reproductive parasite. However, Wolbachia is necessary for oogenesis completion in the wasp Asobara tabida. This dependence has evolved recently as a result of interference with apoptosis during oogenesis. Through comparative transcriptomics between symbiotic and aposymbiotic individuals, we observed a differential expression of ferritin, which forms a complex involved in iron storage. Iron is an essential element that is in limited supply in the cell. However, it is also a highly toxic precursor of Reactive Oxygen Species (ROS). Ferritin has also been shown to play a key role in host-pathogen interactions. Measuring ferritin by quantitative RT-PCR, we confirmed that ferritin was upregulated in aposymbiotic compared to symbiotic individuals. Manipulating the iron content in the diet, we showed that iron overload markedly affected wasp development and induced apoptotic processes during oogenesis in A. tabida, suggesting that the regulation of iron homeostasis may also be related to the obligate dependence of the wasp. Finally, we demonstrated that iron metabolism is influenced by the presence of Wolbachia not only in the obligate mutualism with A. tabida, but also in facultative parasitism involving Drosophila simulans and in Aedes aegypti cells. In these latter cases, the expression of Wolbachia bacterioferritin was also increased in the presence of iron, showing that Wolbachia responds to the concentration of iron. Our results indicate that Wolbachia may generally interfere with iron metabolism. The high affinity of Wolbachia for iron might be due to physiological requirement of the bacterium, but it could also be what allows the symbiont to persist in the organism by reducing the labile iron concentration, thus protecting the cell from oxidative stress and apoptosis. These findings also reinforce the idea that pathogenic, parasitic and mutualistic intracellular bacteria all use the same molecular mechanisms to survive and replicate within host cells. By impacting the general physiology of the host, the presence of a symbiont may select for host compensatory mechanisms, which extends the possible consequences of persistent endosymbiont on the evolution of their hosts.}, }
@article {pmid19850725, year = {2010}, author = {Kaminuma, E and Mashima, J and Kodama, Y and Gojobori, T and Ogasawara, O and Okubo, K and Takagi, T and Nakamura, Y}, title = {DDBJ launches a new archive database with analytical tools for next-generation sequence data.}, journal = {Nucleic acids research}, volume = {38}, number = {Database issue}, pages = {D33-8}, pmid = {19850725}, issn = {1362-4962}, mesh = {Algorithms ; Animals ; Computational Biology/*methods/trends ; *Databases, Genetic ; *Databases, Nucleic Acid ; Databases, Protein ; Genome, Bacterial ; Humans ; Information Storage and Retrieval/methods ; Internet ; Japan ; Software ; }, abstract = {The DNA Data Bank of Japan (DDBJ) (http://www.ddbj.nig.ac.jp) has collected and released 1,701,110 entries/1,116,138,614 bases between July 2008 and June 2009. A few highlighted data releases from DDBJ were the complete genome sequence of an endosymbiont within protist cells in the termite gut and Cap Analysis Gene Expression tags for human and mouse deposited from the Functional Annotation of the Mammalian cDNA consortium. In this period, we started a novel user announcement service using Really Simple Syndication (RSS) to deliver a list of data released from DDBJ on a daily basis. Comprehensive visualization of a DDBJ release data was attempted by using a word cloud program. Moreover, a new archive for sequencing data from next-generation sequencers, the 'DDBJ Read Archive' (DRA), was launched. Concurrently, for read data registered in DRA, a semi-automatic annotation tool called the 'DDBJ Read Annotation Pipeline' was released as a preliminary step. The pipeline consists of two parts: basic analysis for reference genome mapping and de novo assembly and high-level analysis of structural and functional annotations. These new services will aid users' research and provide easier access to DDBJ databases.}, }
@article {pmid19847819, year = {2009}, author = {Bodył, A and Mackiewicz, P and Stiller, JW}, title = {Early steps in plastid evolution: current ideas and controversies.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {31}, number = {11}, pages = {1219-1232}, doi = {10.1002/bies.200900073}, pmid = {19847819}, issn = {1521-1878}, mesh = {Arabidopsis/metabolism ; Biological Evolution ; Carbonic Anhydrases/*genetics ; Cell Membrane/metabolism ; Evolution, Molecular ; Glycosylation ; Mitochondria/metabolism ; Models, Biological ; Models, Theoretical ; Peptides/chemistry ; Phosphates/metabolism ; Plastids/*genetics/metabolism ; Protein Processing, Post-Translational ; Protein Transport ; Symbiosis ; }, abstract = {Some nuclear-encoded proteins are imported into higher plant plastids via the endomembrane (EM) system. Compared with multi-protein Toc and Tic translocons required for most plastid protein import, the relatively uncomplicated nature of EM trafficking led to suggestions that it was the original transport mechanism for nuclear-encoded endosymbiont proteins, and critical for the early stages of plastid evolution. Its apparent simplicity disappears, however, when EM transport is considered in light of selective constraints likely encountered during the conversion of stable endosymbionts into fully integrated organelles. From this perspective it is more parsimonious to presume the early evolution of post-translational protein import via simpler, ancestral forms of modern Toc and Tic plastid translocons, with EM trafficking arising later to accommodate glycosylation and/or protein targeting to multiple cellular locations. This hypothesis is supported by both empirical and comparative data, and is consistent with the relative paucity of EM-based transport to modern primary plastids.}, }
@article {pmid19843329, year = {2009}, author = {Stiller, JW and Huang, J and Ding, Q and Tian, J and Goodwillie, C}, title = {Are algal genes in nonphotosynthetic protists evidence of historical plastid endosymbioses?.}, journal = {BMC genomics}, volume = {10}, number = {}, pages = {484}, pmid = {19843329}, issn = {1471-2164}, mesh = {Computational Biology ; DNA, Algal/genetics ; Databases, Genetic ; Diatoms/genetics ; *Evolution, Molecular ; *Models, Genetic ; Phytophthora/*genetics ; Plastids/*genetics ; Rhodophyta/*genetics ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: How photosynthetic organelles, or plastids, were acquired by diverse eukaryotes is among the most hotly debated topics in broad scale eukaryotic evolution. The history of plastid endosymbioses commonly is interpreted under the "chromalveolate" hypothesis, which requires numerous plastid losses from certain heterotrophic groups that now are entirely aplastidic. In this context, discoveries of putatively algal genes in plastid-lacking protists have been cited as evidence of gene transfer from a photosynthetic endosymbiont that subsequently was lost completely. Here we examine this evidence, as it pertains to the chromalveolate hypothesis, through genome-level statistical analyses of similarity scores from queries with two diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana, and two aplastidic sister taxa, Phytophthora ramorum and P. sojae.<br><br>RESULTS: Contingency tests of specific predictions of the chromalveolate model find no evidence for an unusual red algal contribution to Phytophthora genomes, nor that putative cyanobacterial sequences that are present entered these genomes through a red algal endosymbiosis. Examination of genes unrelated to plastid function provide extraordinarily significant support for both of these predictions in diatoms, the control group where a red endosymbiosis is known to have occurred, but none of that support is present in genes specifically conserved between diatoms and oomycetes. In addition, we uncovered a strong association between overall sequence similarities among taxa and relative sizes of genomic data sets in numbers of genes.<br><br>CONCLUSION: Signal from "algal" genes in oomycete genomes is inconsistent with the chromalveolate hypothesis, and better explained by alternative models of sequence and genome evolution. Combined with the numerous sources of intragenomic phylogenetic conflict characterized previously, our results underscore the potential to be mislead by a posteriori interpretations of variable phylogenetic signals contained in complex genome-level data. They argue strongly for explicit testing of the different a priori assumptions inherent in competing evolutionary hypotheses.}, }
@article {pmid19825106, year = {2009}, author = {Pfarr, KM and Debrah, AY and Specht, S and Hoerauf, A}, title = {Filariasis and lymphoedema.}, journal = {Parasite immunology}, volume = {31}, number = {11}, pages = {664-672}, pmid = {19825106}, issn = {1365-3024}, mesh = {Animals ; Elephantiasis, Filarial/*complications/parasitology ; Humans ; Immune Tolerance ; Immunity, Innate ; Lymphatic Vessels/metabolism/physiopathology ; Lymphedema/*etiology/metabolism/physiopathology ; Vascular Endothelial Growth Factor A/immunology/metabolism ; Wolbachia/immunology ; }, abstract = {Among the causes of lymphoedema (LE), secondary LE due to filariasis is the most prevalent. It affects only a minority of the 120 million people infected with the causative organisms of lymphatic filariasis (LF), Wuchereria bancrofti and Brugia malayi/timori, but is clustered in families, indicating a genetic basis for development of this pathology. The majority of infected individuals develop filarial-specific immunosuppression that starts even before birth in cases where mothers are infected and is characterized by regulatory T-cell responses and high levels of IgG4, thus tolerating high parasite loads and microfilaraemia. In contrast, individuals with this pathology show stronger immune reactions biased towards Th1, Th2 and probably also Th17. Importantly, as for the aberrant lymph vessel development, innate immune responses that are triggered by the filarial antigen ultimately result in the activation of vascular endothelial growth factors (VEGF), thus promoting lymph vessel hyperplasia as a first step to lymphoedema development. Wolbachia endosymbionts are major inducers of these responses in vitro, and their depletion by doxycycline in LF patients reduces plasma VEGF and soluble VEGF-receptor-3 levels to those seen in endemic normals preceding pathology improvement. The search for the immunogenetic basis for LE could lead to the identification of risk factors and thus, to prevention; and has so far led to the identification of single-nucleotide polymorphisms (SNP) with potential functional relevance to VEGF, cytokine and toll-like receptor (TLR) genes. Hydrocele, a pathology with some similarity to LE in which both lymph vessel dilation and lymph extravasation are shared sequelae, has been found to be strongly associated with a VEGF-A SNP known for upregulation of this (lymph-)angiogenesis factor.}, }
@article {pmid19821733, year = {2009}, author = {Bressan, A and Sémétey, O and Arneodo, J and Lherminier, J and Boudon-Padieu, E}, title = {Vector transmission of a plant-pathogenic bacterium in the Arsenophonus clade sharing ecological traits with facultative insect endosymbionts.}, journal = {Phytopathology}, volume = {99}, number = {11}, pages = {1289-1296}, doi = {10.1094/PHYTO-99-11-1289}, pmid = {19821733}, issn = {0031-949X}, mesh = {Animals ; Beta vulgaris/*microbiology ; Biological Evolution ; Female ; Gammaproteobacteria/*physiology ; Hemiptera/growth &amp; development/*microbiology/ultrastructure ; Insect Vectors/*microbiology ; Male ; Microscopy, Electron, Transmission ; Nymph/microbiology ; Plant Diseases/microbiology ; Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {The planthopper Pentastiridius leporinus (Hemiptera: Cixiidae) is the major vector of a nonculturable plant-pathogenic gamma-3 proteobacterium associated with a disease of sugar beet called syndrome "basses richesses" (SBR). The bacterium, here called SBR bacterium, belongs to the Arsenophonous clade, which includes mostly insect-associated facultative symbionts. Assays using field-collected planthopper nymphs and adults were carried out to investigate the interaction of SBR bacterium with the insect vector and its transmission to sugar beet. Field-collected planthoppers showed a percentage of infection that averaged from 57% for early instar nymphs to near 100% for late instar nymphs and emerging adults. SBR bacterium was persistently transmitted by emerging adults. Root-feeding nymphs were able to inoculate SBR bacterium to sugar beet. The bacterium was transmitted vertically from infected parental females to their respective offspring with an average frequency of 30%. Real-time polymerase chain reaction assays on dissected planthopper internal organs revealed a high concentration of the bacterium within male and female reproductive organs and within female salivary glands. SBR-like bacteria were observed through transmission electron microscopy in the cytoplasm of different insect organs including ovaries, salivary glands, and guts with no evidence for cytological disorders. SBR bacterium seems to share common ecological traits of insect-transmitted plant pathogens and facultative insect endosymbionts suggesting it may have evolved primarily as an insect-associated bacterium.}, }
@article {pmid19820157, year = {2009}, author = {Sun, HY and Noe, J and Barber, J and Coyne, RS and Cassidy-Hanley, D and Clark, TG and Findly, RC and Dickerson, HW}, title = {Endosymbiotic bacteria in the parasitic ciliate Ichthyophthirius multifiliis.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {23}, pages = {7445-7452}, pmid = {19820157}, issn = {1098-5336}, mesh = {Animals ; Ciliophora/*microbiology/physiology ; Cluster Analysis ; Cytoplasm/microbiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Flavobacterium/*isolation &amp; purification ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*isolation &amp; purification ; Sequence Analysis, DNA ; Sphingobacterium/*isolation &amp; purification ; *Symbiosis ; }, abstract = {Endosymbiotic bacteria were identified in the parasitic ciliate Ichthyophthirius multifiliis, a common pathogen of freshwater fish. PCR amplification of DNA prepared from two isolates of I. multifiliis, using primers that bind conserved sequences in bacterial 16S rRNA genes, generated an approximately 1,460-bp DNA product, which was cloned and sequenced. Sequence analysis demonstrated that 16S rRNA gene sequences from three classes of bacteria were present in the PCR product. These included Alphaproteobacteria (Rickettsiales), Sphingobacteria, and Flavobacterium columnare. DAPI (4',6-diamidino-2-phenylindole) staining showed endosymbionts dispersed throughout the cytoplasm of trophonts and, in most, but not all theronts. Endosymbionts were observed by transmission electron microscopy in the cytoplasm, surrounded by a prominent, electron-translucent halo characteristic of Rickettsia. Fluorescence in situ hybridization demonstrated that bacteria from the Rickettsiales and Sphingobacteriales classes are endosymbionts of I. multifiliis, found in the cytoplasm, but not in the macronucleus or micronucleus. In contrast, F. columnare was not detected by fluorescence in situ hybridization. It likely adheres to I. multifiliis through association with cilia. The role that endosymbiotic bacteria play in the life history of I. multifiliis is not known.}, }
@article {pmid19820149, year = {2009}, author = {Suh, E and Mercer, DR and Fu, Y and Dobson, SL}, title = {Pathogenicity of life-shortening Wolbachia in Aedes albopictus after transfer from Drosophila melanogaster.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {24}, pages = {7783-7788}, pmid = {19820149}, issn = {1098-5336}, mesh = {Aedes/genetics/*microbiology/*physiology ; Animals ; Cytoplasm/microbiology ; Drosophila melanogaster/*microbiology ; Embryo, Nonmammalian/microbiology ; Female ; Fertility ; Longevity ; Male ; Mosquito Control ; Symbiosis ; Wolbachia/genetics/*pathogenicity/*physiology ; }, abstract = {Maternally inherited Wolbachia bacteria have evolved mechanisms to manipulate the reproduction of their invertebrate hosts, promoting infection spread. A high fitness cost to the host is maladaptive for obligate endosymbionts, and prior studies show rapid selection of new Wolbachia associations toward commensal or mutualistic symbioses. Here, wMelPop Wolbachia is transferred from Drosophila melanogaster into the mosquito Aedes albopictus. Characterization of the resulting strain provides an extreme example of Wolbachia as a pathogen. In addition to reduced longevity and fecundity, abnormally high Wolbachia density is associated with embryonic mortality that masks the typical pattern of cytoplasmic incompatibility. The results are consistent with earlier reports that show unpredictable shifts in the Wolbachia phenotype after interspecific transfer, which can complicate proposed strategies to modify the age structure of medically important vector populations.}, }
@article {pmid19812617, year = {2010}, author = {Harris, LR and Kelly, SE and Hunter, MS and Perlman, SJ}, title = {Population dynamics and rapid spread of Cardinium, a bacterial endosymbiont causing cytoplasmic incompatibility in Encarsia pergandiella (Hymenoptera: Aphelinidae).}, journal = {Heredity}, volume = {104}, number = {3}, pages = {239-246}, doi = {10.1038/hdy.2009.130}, pmid = {19812617}, issn = {1365-2540}, mesh = {Animals ; Bacteroidetes/genetics/*physiology ; Female ; Infertility ; Male ; Molecular Sequence Data ; Population Dynamics ; *Symbiosis ; Wasps/genetics/*microbiology/*physiology ; }, abstract = {Cytoplasmic incompatibility (CI) is a common phenotype of maternally inherited bacterial symbionts of arthropods; in its simplest expression, uninfected females produce few or no viable progeny when mated to infected males. Infected females thus experience a reproductive advantage relative to that of uninfected females, with the potential for the symbiont to spread rapidly. CI population dynamics are predicted to depend primarily on the strength of incompatibility, the fitness cost of the infection and how faithfully symbionts are inherited. Although the bacterial symbiont lineage Wolbachia has been most identified with the CI phenotype, an unrelated bacterium, Cardinium may also cause CI. In the first examination of population dynamics of CI-inducing Cardinium, we used population cages of the parasitic wasp Encarsia pergandiella (Hymenoptera: Aphelinidae) with varying initial infection frequencies to test a model of invasion. Cardinium was found to spread rapidly in all populations, even in cases where the initial infection frequency was well below the predicted invasion threshold frequency. The discrepancy between the modeled and actual results is best explained by weaker CI than measured in the lab and a cryptic fitness benefit to the infection.}, }
@article {pmid19812409, year = {2009}, author = {Hoerauf, A}, title = {Mansonella perstans--the importance of an endosymbiont.}, journal = {The New England journal of medicine}, volume = {361}, number = {15}, pages = {1502-1504}, doi = {10.1056/NEJMe0905193}, pmid = {19812409}, issn = {1533-4406}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Doxycycline/*therapeutic use ; Drug Therapy, Combination ; Elephantiasis, Filarial/complications/drug therapy ; Filaricides/*therapeutic use ; Humans ; Mansonella ; Mansonelliasis/complications/*drug therapy ; Rickettsiaceae Infections/*complications/drug therapy ; *Symbiosis ; *Wolbachia ; Wuchereria bancrofti/isolation &amp; purification ; }, }
@article {pmid19812401, year = {2009}, author = {Coulibaly, YI and Dembele, B and Diallo, AA and Lipner, EM and Doumbia, SS and Coulibaly, SY and Konate, S and Diallo, DA and Yalcouye, D and Kubofcik, J and Doumbo, OK and Traore, AK and Keita, AD and Fay, MP and Traore, SF and Nutman, TB and Klion, AD}, title = {A randomized trial of doxycycline for Mansonella perstans infection.}, journal = {The New England journal of medicine}, volume = {361}, number = {15}, pages = {1448-1458}, pmid = {19812401}, issn = {1533-4406}, support = {ZIA AI001063-04/ImNIH/Intramural NIH HHS/United States ; }, mesh = {Adolescent ; Adult ; Aged ; Albendazole/therapeutic use ; Animals ; Anti-Bacterial Agents/administration &amp; dosage/adverse effects/*therapeutic use ; Doxycycline/administration &amp; dosage/adverse effects/*therapeutic use ; Drug Therapy, Combination ; Elephantiasis, Filarial/complications/drug therapy ; Female ; Filaricides/*therapeutic use ; Humans ; Ivermectin/therapeutic use ; Male ; *Mansonella/isolation &amp; purification ; Mansonelliasis/complications/*drug therapy ; Middle Aged ; Rickettsiaceae Infections/complications/*drug therapy ; Symbiosis ; Treatment Outcome ; *Wolbachia ; Wuchereria bancrofti/isolation &amp; purification ; Young Adult ; }, abstract = {BACKGROUND: Mansonella perstans infection is common in areas of Africa where Wuchereria bancrofti, a causative agent of lymphatic filariasis, is endemic. M. perstans is refractory to standard antifilarial therapies. The recent discovery of bacterial endosymbionts (e.g., wolbachia) in most filarial species, including M. perstans, provides new therapeutic options for reducing microfilaremia.<br><br>METHODS: In an open-label, randomized trial, we recruited subjects with M. perstans microfilaremia, with or without concomitant W. bancrofti infection, from four villages in Mali and randomly assigned them to receive doxycycline, at a dose of 200 mg daily for 6 weeks (106 subjects), or no treatment (110). At 6 months, subjects who were coinfected with W. bancrofti underwent a second random assignment, to treatment with a single dose of albendazole (400 mg) and ivermectin (150 microg per kilogram of body weight) or no treatment. Subjects were monitored daily during the first 6-week study period for adverse events. M. perstans and W. bancrofti microfilarial levels were assessed at 6, 12, and 36 months.<br><br>RESULTS: At 12 months, 67 of 69 subjects who had received treatment with doxycycline only (97%) had no detectable M. perstans microfilariae per 60 microl of blood, as compared with 10 of 63 subjects who had received no treatment (16%) (relative risk, 6.18; 95% confidence interval, 3.63 to 11.89; P<0.001). At 36 months, M. perstans microfilaremia remained suppressed in 48 of 64 subjects who had received treatment with doxycycline only (75%), a finding that was consistent with a macrofilaricidal effect of doxycycline. Vomiting was more frequent in the doxycycline-treated group than in the untreated group (17% vs. 4%).<br><br>CONCLUSIONS: These results are consistent with previous findings that M. perstans harbors the intracellular endosymbiont, wolbachia, and suggest that doxycycline is an effective therapy for M. perstans infection. (ClinicalTrials.gov number, NCT00340691.)}, }
@article {pmid19810815, year = {2009}, author = {Sinharoy, S and DasGupta, M}, title = {RNA interference highlights the role of CCaMK in dissemination of endosymbionts in the Aeschynomeneae legume Arachis.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {22}, number = {11}, pages = {1466-1475}, doi = {10.1094/MPMI-22-11-1466}, pmid = {19810815}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Arachis/genetics/*metabolism ; Gene Expression Regulation, Plant/*physiology ; Models, Molecular ; Mycorrhizae/*physiology ; Phylogeny ; Plant Root Nodulation/genetics/*physiology ; Protein Conformation ; *RNA Interference ; Symbiosis/physiology ; }, abstract = {In legume-rhizobia symbiosis, Ca2+/calmodulin-dependent protein kinase (CCaMK) is essential for rhizobial invasion through infection threads in the epidermis and nodule organogenesis in the cortex. Though CCaMK is actively transcribed in the infected zone of nodules, its role in the later stages of nodule development remain elusive because of the epidermal arrest of "loss-of-function" mutants. In Aeschynomeneae legumes such as Arachis hypogea, rhizobia directly access the cortex, where nodule organogenesis as well as endosymbiont dissemination take place by multiplication of infected cortical cells. We characterized CCaMK (GI:195542474) from A. hypogea and downregulated the kinase through RNA interference (RNAi) to understand its role during organogenesis of its characteristic aeschynomenoid nodules. In CCaMK downregulated plants, the inception of nodules was delayed by approximately 4 weeks and nodulation capacity was decreased (>90%). The infected zones of the RNA interference nodules were scattered with uninfected or binucleated cells as opposed to the homogeneous infection zone in empty-vector-transformed nodules. Symbiosomes in RNAi nodules were pleomorphic with diverse geometrical shapes or arrested during division in the final stages of their fission as opposed to uniform-sized, spherical symbiosomes in empty-vector-transformed nodules. Together, our results reveal CCaMK to be essential for development of functional aeschynomenoid nodules, with a critical role in rhizobial dissemination during nodule organogenesis.}, }
@article {pmid19808683, year = {2009}, author = {Agrawal, S and van Dooren, GG and Beatty, WL and Striepen, B}, title = {Genetic evidence that an endosymbiont-derived endoplasmic reticulum-associated protein degradation (ERAD) system functions in import of apicoplast proteins.}, journal = {The Journal of biological chemistry}, volume = {284}, number = {48}, pages = {33683-33691}, pmid = {19808683}, issn = {1083-351X}, support = {R01 AI064671/AI/NIAID NIH HHS/United States ; AI64671/AI/NIAID NIH HHS/United States ; }, mesh = {Adenosine Triphosphatases/classification/genetics/metabolism ; Animals ; Blotting, Western ; Cell Cycle Proteins/classification/genetics/metabolism ; Cryoelectron Microscopy ; Endoplasmic Reticulum/*metabolism ; Eukaryota/physiology ; Fibroblasts/parasitology/ultrastructure ; Fluorescent Antibody Technique ; Humans ; Intracellular Membranes/metabolism ; Molecular Sequence Data ; Mutation ; Phylogeny ; Plastids/*metabolism ; Protein Transport ; Protozoan Proteins/classification/genetics/*metabolism ; Sequence Analysis, DNA ; Symbiosis ; Toxoplasma/genetics/*metabolism/microbiology ; Valosin Containing Protein ; }, abstract = {Most apicomplexan parasites harbor a relict chloroplast, the apicoplast, that is critical for their survival. Whereas the apicoplast maintains a small genome, the bulk of its proteins are nuclear encoded and imported into the organelle. Several models have been proposed to explain how proteins might cross the four membranes that surround the apicoplast; however, experimental data discriminating these models are largely missing. Here we present genetic evidence that apicoplast protein import depends on elements derived from the ER-associated protein degradation (ERAD) system of the endosymbiont. We identified two sets of ERAD components in Toxoplasma gondii, one associated with the ER and cytoplasm and one localized to the membranes of the apicoplast. We engineered a conditional null mutant in apicoplast Der1, the putative pore of the apicoplast ERAD complex, and found that loss of Der1(Ap) results in loss of apicoplast protein import and subsequent death of the parasite.}, }
@article {pmid19806204, year = {2009}, author = {Ghedin, E and Hailemariam, T and DePasse, JV and Zhang, X and Oksov, Y and Unnasch, TR and Lustigman, S}, title = {Brugia malayi gene expression in response to the targeting of the Wolbachia endosymbiont by tetracycline treatment.}, journal = {PLoS neglected tropical diseases}, volume = {3}, number = {10}, pages = {e525}, pmid = {19806204}, issn = {1935-2735}, support = {R01 AI072465/AI/NIAID NIH HHS/United States ; AI072465/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Brugia malayi/*drug effects/*genetics/microbiology/physiology ; Female ; Gene Expression Regulation/*drug effects ; Helminth Proteins/genetics ; *Symbiosis ; Tetracycline/*pharmacology ; Wolbachia/*drug effects/physiology ; }, abstract = {BACKGROUND: Brugia malayi, like most human filarial parasite species, harbors an endosymbiotic bacterium of the genus Wolbachia. Elimination of the endosymbiont leads to sterilization of the adult female. Previous biochemical and genetic studies have established that communication with its endobacterium is essential for survival of the worm.<br><br>We used electron microscopy to examine the effects of antibiotic treatment on Wolbachia cell structure. We have also used microarray and quantitative RT-PCR analyses to examine the regulation of the B. malayi transcripts altered in response to the anti-Wolbachia treatment. Microscopy of worms taken from animals treated with tetracycline for 14 and 21 days (14 d and 21 d) demonstrated substantial morphologic effects on the Wolbachia endobacterium by 14 d and complete degeneration of the endobacterial structures by 21 d. We observed upregulation of transcripts primarily encoding proteins involved in amino acid synthesis and protein translation, and downregulation of transcripts involved in cuticle biosynthesis after both 7 d and 14 d of treatment. In worms exposed to tetracycline in culture, substantial effects on endobacteria morphology were evident by day 3, and extensive death of the endobacteria was observed by day 5. In a detailed examination of the expression kinetics of selected signaling genes carried out on such cultured worms, a bimodal pattern of regulation was observed. The selected genes were upregulated during the early phase of antibiotic treatment and quickly downregulated in the following days. These same genes were upregulated once more at 6 days post-treatment.<br><br>CONCLUSIONS/SIGNIFICANCE: Upregulation of protein translation and amino acid synthesis may indicate a generalized stress response induced in B. malayi due to a shortage of essential nutrients/factors that are otherwise supplied by Wolbachia. Downregulation of transcripts involved in cuticle biosynthesis perhaps reflects a disruption in the normal embryogenic program. This is confirmed by the expression pattern of transcripts that may be representative of the worms' response to Wolbachia in different tissues; the early peak potentially reflects the effect of bacteria death on the embryogenic program while the second peak may be a manifestation of the adult worm response to the affected bacteria within the hypodermis.}, }
@article {pmid19805299, year = {2009}, author = {Peccoud, J and Simon, JC and McLaughlin, HJ and Moran, NA}, title = {Post-Pleistocene radiation of the pea aphid complex revealed by rapidly evolving endosymbionts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, number = {38}, pages = {16315-16320}, pmid = {19805299}, issn = {1091-6490}, mesh = {Animals ; Aphids/*classification/genetics/microbiology ; Buchnera/*genetics/physiology ; DNA, Bacterial/genetics ; Evolution, Molecular ; Genetic Variation ; Host-Pathogen Interactions ; Models, Genetic ; Peas/*parasitology ; *Phylogeny ; Symbiosis/genetics ; Time Factors ; }, abstract = {Adaptation to different resources has the potential to cause rapid species diversification, but few studies have been able to quantify the time scale of recent adaptive radiations. The pea aphid, Acyrthosiphon pisum, a model of speciation for host-specialized parasites, consists of several biotypes (races or species) living on distinct legume hosts. To document this radiation, we used rapidly evolving sequences from Buchnera, the maternally transmitted bacterial endosymbiont of aphids. Analyses of Buchnera pseudogene sequences revealed that 11 host-associated biotypes sort mostly into distinct matrilines despite low sequence divergence. A calibration based on divergence times of 7 sequenced genomes of Buchnera allowed us to date the last maternal ancestor of these biotypes between 8,000 and 16,000 years, with a burst of diversification at an estimated 3,600-9,500 years. The recency of this diversification, which is supported by microsatellite data, implies that the pea aphid complex ranks among the most rapid adaptive radiations yet documented. This diversification coincides with post-Pleistocene warming and with the domestication and anthropogenic range expansion of several of the legume hosts of pea aphids. Thus, we hypothesize that the new availability or abundance of resources triggered a cascade of divergence events in this newly formed complex.}, }
@article {pmid19788732, year = {2009}, author = {Kuo, CH and Ochman, H}, title = {Inferring clocks when lacking rocks: the variable rates of molecular evolution in bacteria.}, journal = {Biology direct}, volume = {4}, number = {}, pages = {35}, pmid = {19788732}, issn = {1745-6150}, support = {R01 GM056120/GM/NIGMS NIH HHS/United States ; GM56120/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacteria/*genetics ; Base Sequence ; Calibration ; Conserved Sequence ; *Evolution, Molecular ; *Fossils ; Genetic Variation ; Open Reading Frames/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis/genetics ; Time Factors ; }, abstract = {BACKGROUND: Because bacteria do not have a robust fossil record, attempts to infer the timing of events in their evolutionary history requires comparisons of molecular sequences. This use of molecular clocks is based on the assumptions that substitution rates for homologous genes or sites are fairly constant through time and across taxa. Violation of these conditions can lead to erroneous inferences and result in estimates that are off by orders of magnitude. In this study, we examine the consistency of substitution rates among a set of conserved genes in diverse bacterial lineages, and address the questions regarding the validity of molecular dating.<br><br>RESULTS: By examining the evolution of 16S rRNA gene in obligate endosymbionts, which can be calibrated by the fossil record of their hosts, we found that the rates are consistent within a clade but varied widely across different bacterial lineages. Genome-wide estimates of nonsynonymous and synonymous substitutions suggest that these two measures are highly variable in their rates across bacterial taxa. Genetic drift plays a fundamental role in determining the accumulation of substitutions in 16S rRNA genes and at nonsynonymous sites. Moreover, divergence estimates based on a set of universally conserved protein-coding genes also exhibit low correspondence to those based on 16S rRNA genes.<br><br>CONCLUSION: Our results document a wide range of substitution rates across genes and bacterial taxa. This high level of variation cautions against the assumption of a universal molecular clock for inferring divergence times in bacteria. However, by applying relative-rate tests to homologous genes, it is possible to derive reliable local clocks that can be used to calibrate bacterial evolution.<br><br>REVIEWERS: This article was reviewed by Adam Eyre-Walker, Simonetta Gribaldo and Tal Pupko (nominated by Dan Graur).}, }
@article {pmid19777955, year = {2009}, author = {Michalik, A and Jankowska, W and Szklarzewicz, T}, title = {Ultrastructure and transovarial transmission of endosymbiotic microorganisms in Conomelus anceps and Metcalfa pruinosa (Insecta, Hemiptera, Fulgoromorpha).}, journal = {Folia biologica}, volume = {57}, number = {3-4}, pages = {131-137}, doi = {10.3409/fb57_3-4.131-137}, pmid = {19777955}, issn = {0015-5497}, mesh = {Animals ; Female ; Hemiptera/*microbiology/physiology/ultrastructure ; Male ; Microscopy, Electron, Transmission ; Ovary/*microbiology/physiology/ultrastructure ; Symbiosis/*physiology ; Yeasts/*physiology/ultrastructure ; }, abstract = {Endosymbiotic microorganisms commonly occur in fulgoromorphans, as in other plant sap-sucking hemipterans. Large syncytial organs termed mycetomes are present in the body cavities of Conomelus anceps (Delphacidae) and Metcalfa pruinosa (Flatidae), in the close vicinity of the ovaries. The mycetomes are surrounded by a one-layered epithelium. The mycetome cytoplasm is filled with yeast-like symbiotic microorganisms (YLSs). The YLSs are transovarially transmitted to the next generation. The endosymbionts are released from the mycetomes and migrate towards the ovarioles containing vitellogenic oocytes. The YLSs pass through the cells of the ovariole stalk (pedicel) and enter the perivitelline space. Then, a deep depression is formed at the posterior pole of the oocyte. The YLSs accumulate in the oocyte depression and form a characteristic "symbiont ball". The mycetome cytoplasm of Metcalfa pruinosa as well as epithelial cells surrounding the mycetome contain small, rod-shaped bacteria.}, }
@article {pmid19776066, year = {2010}, author = {Vorburger, C and Gehrer, L and Rodriguez, P}, title = {A strain of the bacterial symbiont Regiella insecticola protects aphids against parasitoids.}, journal = {Biology letters}, volume = {6}, number = {1}, pages = {109-111}, pmid = {19776066}, issn = {1744-957X}, mesh = {Animals ; Aphids/*microbiology/parasitology ; Australia ; Base Sequence ; Body Size ; Enterobacteriaceae/genetics/*physiology ; Fertility/physiology ; Host-Parasite Interactions ; Linear Models ; Molecular Sequence Data ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Wasps/physiology ; }, abstract = {Aphids commonly harbour facultative bacterial endosymbionts and may benefit from their presence through increased resistance to parasitoids. This has been demonstrated for Hamiltonella defensa and Serratia symbiotica, while a third common endosymbiont, Regiella insecticola, did not provide such protection. However, this symbiont was recently detected in a highly resistant clone of the peach-potato aphid, Myzus persicae, from Australia. To test if resistance was indeed conferred by the endosymbiont, we eliminated it from this clone with antibiotics, and we transferred it to two other clones of the same and one clone of a different aphid species (Aphis fabae). Exposing these lines to the parasitoid Aphidius colemani showed clearly that unlike other strains of this bacterium, this specific isolate of R. insecticola provides strong protection against parasitic wasps, suggesting that the ability to protect their host against natural enemies may evolve readily in multiple species of endosymbiotic bacteria.}, }
@article {pmid19773076, year = {2009}, author = {Vavre, F and Mouton, L and Pannebakker, BA}, title = {Drosophila-parasitoid communities as model systems for host-Wolbachia interactions.}, journal = {Advances in parasitology}, volume = {70}, number = {}, pages = {299-331}, doi = {10.1016/S0065-308X(09)70012-0}, pmid = {19773076}, issn = {2163-6079}, mesh = {Animals ; Biological Evolution ; Drosophila/*parasitology ; Drosophila melanogaster/parasitology ; Female ; Genetic Variation ; Host-Parasite Interactions/*physiology ; Male ; *Models, Biological ; Oogenesis/physiology ; Phenotype ; Phylogeny ; Wasps/microbiology/*physiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia bacteria are cytoplasmic endosymbionts that infect a wide range of arthropod and nematode hosts. They are transmitted from mother to offspring via the eggs (vertical transmission) and enhance their transmission to the next generation by manipulating the reproductive system of their hosts. These manipulations occur in many forms, such as the induction of cytoplasmic incompatibility, feminization, male killing and parthenogenesis induction. Wolbachia is estimated to occur in up to 66% of all insect species, but the greatest diversity of reproductive manipulations is found in the order of the Hymenoptera. Studies of Wolbachia in Drosophila-parasitoid communities have allowed for important insights into different aspects of Wolbachia biology. The extensive knowledge available on Drosophila parasitoids provides a solid base on which to test new hypotheses on host-Wolbachia interactions. The large range of Wolbachia phenotypes present in Drosophila parasitoids, combined with the recent acquisition of the bacteria from their Drosophilid hosts, make them an ideal model system to study the evolution and dynamics of Wolbachia infections, both in the laboratory as in the field. In this chapter, we aim to review the current knowledge on the associations between Wolbachia and Drosophila parasitoids, and identify open questions and specify new research directions.}, }
@article {pmid19767463, year = {2009}, author = {Estes, AM and Hearn, DJ and Bronstein, JL and Pierson, EA}, title = {The olive fly endosymbiont, "Candidatus Erwinia dacicola," switches from an intracellular existence to an extracellular existence during host insect development.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {22}, pages = {7097-7106}, pmid = {19767463}, issn = {1098-5336}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Base Composition ; DNA, Bacterial/chemistry/genetics ; Erwinia/classification/genetics/*physiology ; Extracellular Space/*microbiology ; In Situ Hybridization, Fluorescence ; Intracellular Space/*microbiology ; Larva/microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rec A Recombinases/genetics ; Southwestern United States ; *Symbiosis ; Tephritidae/*microbiology ; }, abstract = {As polyphagous, holometabolous insects, tephritid fruit flies (Diptera: Tephritidae) provide a unique habitat for endosymbiotic bacteria, especially those microbes associated with the digestive system. Here we examine the endosymbiont of the olive fly [Bactrocera oleae (Rossi) (Diptera: Tephritidae)], a tephritid of great economic importance. "Candidatus Erwinia dacicola" was found in the digestive systems of all life stages of wild olive flies from the southwestern United States. PCR and microscopy demonstrated that "Ca. Erwinia dacicola" resided intracellularly in the gastric ceca of the larval midgut but extracellularly in the lumen of the foregut and ovipositor diverticulum of adult flies. "Ca. Erwinia dacicola" is one of the few nonpathogenic endosymbionts that transitions between intracellular and extracellular lifestyles during specific stages of the host's life cycle. Another unique feature of the olive fly endosymbiont is that unlike obligate endosymbionts of monophagous insects, "Ca. Erwinia dacicola" has a G+C nucleotide composition similar to those of closely related plant-pathogenic and free-living bacteria. These two characteristics of "Ca. Erwinia dacicola," the ability to transition between intracellular and extracellular lifestyles and a G+C nucleotide composition similar to those of free-living relatives, may facilitate survival in a changing environment during the development of a polyphagous, holometabolous host. We propose that insect-bacterial symbioses should be classified based on the environment that the host provides to the endosymbiont (the endosymbiont environment).}, }
@article {pmid19762334, year = {2010}, author = {Liu, H and Aris-Brosou, S and Probert, I and de Vargas, C}, title = {A time line of the environmental genetics of the haptophytes.}, journal = {Molecular biology and evolution}, volume = {27}, number = {1}, pages = {161-176}, doi = {10.1093/molbev/msp222}, pmid = {19762334}, issn = {1537-1719}, mesh = {Cell Nucleus/genetics ; Evolution, Molecular ; Metagenomics/*methods ; Models, Genetic ; Phylogeny ; Phytoplankton/classification/*genetics ; Plastids/genetics ; }, abstract = {The use of genomic data and the rise of phylogenomics have radically changed our view of the eukaryotic tree of life at a high taxonomic level by identifying 4-6 "supergroups." Yet, our understanding of the evolution of key innovations within each of these supergroups is limited because of poor species sampling relative to the massive diversity encompassed by each supergroup. Here we apply a multigene approach that incorporates a wide taxonomic diversity to infer the time line of the emergence of strategic evolutionary transitions in the haptophytes, a group of ecologically and biogeochemically significant marine protists that belong to the Chromalveolata supergroup. Four genes (SSU, LSU, tufA, and rbcL) were extensively analyzed under several Bayesian models to assess the robustness of the phylogeny, particularly with respect to 1) data partitioning; 2) the origin of the genes (host vs. endosymbiont); 3) across-site rate variation; and 4) across-lineage rate variation. We show with a relaxed clock analysis that the origin of haptophytes dates back to 824 million years ago (Ma) (95% highest probability density 1,031-637 Ma). Our dating results show that the ability to calcify evolved earlier than previously thought, between 329 and 291 Ma, in the Carboniferous period and that the transition from mixotrophy to autotrophy occurred during the same time period. Although these two transitions precede a habitat change of major diversities from coastal/neritic waters to the pelagic realm (291-243 Ma, around the Permian/Triassic boundary event), the emergence of calcification, full autotrophy, and oceanic lifestyle seem mutually independent.}, }
@article {pmid19753103, year = {2009}, author = {Turley, AP and Moreira, LA and O'Neill, SL and McGraw, EA}, title = {Wolbachia infection reduces blood-feeding success in the dengue fever mosquito, Aedes aegypti.}, journal = {PLoS neglected tropical diseases}, volume = {3}, number = {9}, pages = {e516}, pmid = {19753103}, issn = {1935-2735}, abstract = {BACKGROUND: The mosquito Aedes aegypti was recently transinfected with a life-shortening strain of the endosymbiont Wolbachia pipientis (wMelPop) as the first step in developing a biocontrol strategy for dengue virus transmission. In addition to life-shortening, the wMelPop-infected mosquitoes also exhibit increased daytime activity and metabolic rates. Here we sought to quantify the blood-feeding behaviour of Wolbachia-infected females as an indicator of any virulence or energetic drain associated with Wolbachia infection.<br><br>In a series of blood-feeding trials in response to humans, we have shown that Wolbachia-infected mosquitoes do not differ in their response time to humans, but that as they age they obtain fewer and smaller blood meals than Wolbachia-uninfected controls. Lastly, we observed a behavioural characteristic in the Wolbachia infected mosquitoes best described as a "bendy" proboscis that may explain the decreased biting success.<br><br>CONCLUSIONS/SIGNIFICANCE: Taken together the evidence suggests that wMelPop infection may be causing tissue damage in a manner that intensifies with mosquito age and that leads to reduced blood-feeding success. These behavioural changes require further investigation with respect to a possible physiological mechanism and their role in vectorial capacity of the insect. The selective decrease of feeding success in older mosquitoes may act synergistically with other Wolbachia-associated traits including life-shortening and viral protection in biocontrol strategies.}, }
@article {pmid19747532, year = {2010}, author = {Ogino, K and Tsuneki, K and Furuya, H}, title = {Unique genome of dicyemid mesozoan: highly shortened spliceosomal introns in conservative exon/intron structure.}, journal = {Gene}, volume = {449}, number = {1-2}, pages = {70-76}, doi = {10.1016/j.gene.2009.09.002}, pmid = {19747532}, issn = {1879-0038}, mesh = {Animals ; *Exons ; *Genome ; *Introns ; Parasites/*genetics ; Spliceosomes/*genetics ; }, abstract = {Dicyemids are enigmatic endoparasites, or endosymbionts, living in the renal sac of benthic cephalopod molluscs. The body of dicyemids consists of only 9-41 cells, with neither extracellular matrices nor differentiated tissues. Due to the unusually simple body organization, dicyemids have long been the subject of phylogenetic controversy. Molecular evidences suggest dicyemids are lophotrochozoans that have secondarily lost many morphological characters. We studied 40 genes of the dicyemid Dicyema japonicum and found that their spliceosomal introns are very short (mean length=26 bp). This size was shorter than that of introns of animals, such as Fugu rubripes and Oikopleura dioica which possess compact genome and introns. In the intron size, the dicyemid was nearly equal to the chlorarachniophyte Bigelowiella natans nucleomorph (18-21 bp) which has the shortest introns of any known eukaryote. Despite the short introns, the intron density (5.3 introns/gene) of the dicyemid is similar to that in model invertebrates. In addition, the exon/intron structure of the dicyemid is more similar to vertebrates than to the model invertebrates. These results suggest that the positions of the introns are possibly conserved under functional constraints.}, }
@article {pmid19747389, year = {2009}, author = {Chan, YL and Pochon, X and Fisher, MA and Wagner, D and Concepcion, GT and Kahng, SE and Toonen, RJ and Gates, RD}, title = {Generalist dinoflagellate endosymbionts and host genotype diversity detected from mesophotic (67-100 m depths) coral Leptoseris.}, journal = {BMC ecology}, volume = {9}, number = {}, pages = {21}, pmid = {19747389}, issn = {1472-6785}, mesh = {Animals ; Anthozoa/classification/*genetics ; DNA Fingerprinting ; Dinoflagellida/classification/*genetics/metabolism ; Genetic Variation ; Genotype ; Protozoan Proteins/genetics/metabolism ; Symbiosis ; }, abstract = {BACKGROUND: Mesophotic corals (light-dependent corals in the deepest half of the photic zone at depths of 30-150 m) provide a unique opportunity to study the limits of the interactions between corals and endosymbiotic dinoflagellates in the genus Symbiodinium. We sampled Leptoseris spp. in Hawaii via manned submersibles across a depth range of 67-100 m. Both the host and Symbiodinium communities were genotyped, using a non-coding region of the mitochondrial ND5 intron (NAD5) and the nuclear ribosomal internal transcribed spacer region 2 (ITS2), respectively.<br><br>RESULTS: Coral colonies harbored endosymbiotic communities dominated by previously identified shallow water Symbiodinium ITS2 types (C1_ AF333515, C1c_ AY239364, C27_ AY239379, and C1b_ AY239363) and exhibited genetic variability at mitochondrial NAD5.<br><br>CONCLUSION: This is one of the first studies to examine genetic diversity in corals and their endosymbiotic dinoflagellates sampled at the limits of the depth and light gradients for hermatypic corals. The results reveal that these corals associate with generalist endosymbiont types commonly found in shallow water corals and implies that the composition of the Symbiodinium community (based on ITS2) alone is not responsible for the dominance and broad depth distribution of Leptoseris spp. The level of genetic diversity detected in the coral NAD5 suggests that there is undescribed taxonomic diversity in the genus Leptoseris from Hawaii.}, }
@article {pmid19744675, year = {2009}, author = {Carnahan, EA and Hoare, AM and Hallock, P and Lidz, BH and Reich, CD}, title = {Foraminiferal assemblages in Biscayne Bay, Florida, USA: responses to urban and agricultural influence in a subtropical estuary.}, journal = {Marine pollution bulletin}, volume = {59}, number = {8-12}, pages = {221-233}, doi = {10.1016/j.marpolbul.2009.08.008}, pmid = {19744675}, issn = {1879-3363}, mesh = {*Agriculture ; *Biodiversity ; Florida ; Foraminifera/*physiology ; Geologic Sediments/*analysis ; Population Density ; *Urban Renewal ; Water Pollutants, Chemical/analysis ; }, abstract = {This study assessed foraminiferal assemblages in Biscayne Bay, Florida, a heavily utilized estuary, interpreting changes over the past 65 years and providing a baseline for future comparisons. Analyses of foraminiferal data at the genus level revealed three distinct biotopes. The assemblage from the northern bay was characterized by stress-tolerant taxa, especially Ammonia, present in low abundances (approximately 2.0 x 10(3) foraminifers/gram) though relatively high diversity (approximately 19 genera/sample). The southwestern margin of the bay was dominated by Ammonia and Quinqueloculina, an assemblage characterized by the lowest diversities (approximately 12 genera/sample) and highest abundances (approximately 1.1 x 10(4) foraminifers/gram), influenced by both reduced salinity and elevated organic-carbon concentrations. A diverse assemblage of smaller miliolids and rotaliids (approximately 26 genera/sample) characterized the open-bay assemblage, which also had a significant component (approximately 10%) of taxa that host algal endosymbionts. In the past 65 years, populations of symbiont-bearing taxa, which are indicators of normal-marine conditions, have decreased while stress-tolerant taxa, especially Ammonia spp., have increased in predominance.}, }
@article {pmid19727445, year = {2009}, author = {Carnoy, C and Roten, CA}, title = {The dif/Xer recombination systems in proteobacteria.}, journal = {PloS one}, volume = {4}, number = {9}, pages = {e6531}, pmid = {19727445}, issn = {1932-6203}, mesh = {Base Sequence ; Binding Sites ; Campylobacter/*genetics ; Escherichia coli/genetics ; Escherichia coli Proteins/*genetics/physiology ; Genetic Variation ; Genome, Bacterial ; Helicobacter/*genetics ; Integrases/*genetics/physiology ; Molecular Sequence Data ; Protein Structure, Tertiary ; Proteobacteria/*genetics ; *Recombination, Genetic ; Sequence Homology, Nucleic Acid ; Species Specificity ; }, abstract = {In E. coli, 10 to 15% of growing bacteria produce dimeric chromosomes during DNA replication. These dimers are resolved by XerC and XerD, two tyrosine recombinases that target the 28-nucleotide motif (dif) associated with the chromosome's replication terminus. In streptococci and lactococci, an alternative system is composed of a unique, Xer-like recombinase (XerS) genetically linked to a dif-like motif (dif(SL)) located at the replication terminus. Preliminary observations have suggested that the dif/Xer system is commonly found in bacteria with circular chromosomes but that assumption has not been confirmed in an exhaustive analysis. The aim of the present study was to extensively characterize the dif/Xer system in the proteobacteria, since this taxon accounts for the majority of genomes sequenced to date. To that end, we analyzed 234 chromosomes from 156 proteobacterial species and showed that most species (87.8%) harbor XerC and XerD-like recombinases and a dif-related sequence which (i) is located in non-coding sequences, (ii) is close to the replication terminus (as defined by the cumulative GC skew) (iii) has a palindromic structure, (iv) is encoded by a low G+C content and (v) contains a highly conserved XerD binding site. However, not all proteobacteria display this dif/XerCD system. Indeed, a sub-group of pathogenic epsilon-proteobacteria (including Helicobacter sp and Campylobacter sp) harbors a different recombination system, composed of a single recombinase (XerH) which is phylogenetically distinct from the other Xer recombinases and a motif (dif(H)) sharing homologies with dif(SL). Furthermore, no homologs to dif or Xer recombinases could be detected in small endosymbiont genomes or in certain bacteria with larger chromosomes like the Legionellales. This raises the question of the presence of other chromosomal deconcatenation systems in these species. Our study highlights the complexity of dif/Xer recombinase systems in proteobacteria and paves the way for systematic detection of these components in prokaryotes.}, }
@article {pmid19722191, year = {2009}, author = {Dangi, A and Vedi, S and Nag, JK and Paithankar, S and Singh, MP and Kar, SK and Dube, A and Misra-Bhattacharya, S}, title = {Tetracycline treatment targeting Wolbachia affects expression of an array of proteins in Brugia malayi parasite.}, journal = {Proteomics}, volume = {9}, number = {17}, pages = {4192-4208}, doi = {10.1002/pmic.200800324}, pmid = {19722191}, issn = {1615-9861}, mesh = {Animals ; Antibodies, Helminth ; Brugia malayi/drug effects/immunology/*metabolism/*microbiology ; Electrophoresis, Gel, Two-Dimensional ; Electrophoresis, Polyacrylamide Gel ; Helminth Proteins/*metabolism ; Immunoblotting ; Parasites/drug effects/*metabolism/*microbiology ; Polymerase Chain Reaction ; Proteome/analysis ; Reproducibility of Results ; Tetracycline/*pharmacology ; Wolbachia/*drug effects ; }, abstract = {Wolbachia is an intracellular endosymbiont of Brugia malayi parasite whose presence is essential for the survival of the parasite. Treatment of B. malayi-infected jirds with tetracycline eliminates Wolbachia, which affects parasite survival and fitness. In the present study we have tried to identify parasite proteins that are affected when Wolbachia is targeted by tetracycline. For this Wolbachia depleted parasites (B. malayi) were obtained by tetracycline treatment of infected Mongolian jirds (Meriones unguiculatus) and their protein profile after 2-DE separation was compared with that of untreated parasites harboring Wolbachia. Approximately 100 protein spots could be visualized followed by CBB staining of 2-D gel and included for comparative analysis. Of these, 54 showed differential expressions, while two new protein spots emerged (of 90.3 and 64.4 kDa). These proteins were subjected to further analysis by MALDI-TOF for their identification using Brugia coding sequence database composed of both genomic and EST sequences. Our study unravels two crucial findings: (i) the parasite or Wolbachia proteins, which disappeared/down-regulated appear be essential for parasite survival and may be used as drug targets and (ii) tetracycline treatment interferes with the regulatory machinery vital for parasites cellular integrity and defense and thus could possibly be a molecular mechanism for the killing of filarial parasite. This is the first proteomic study substantiating the wolbachial genome integrity with its nematode host and providing functional genomic data of human lymphatic filarial parasite B. malayi.}, }
@article {pmid19721822, year = {2009}, author = {Cilia, M and Fish, T and Yang, X and McLaughlin, M and Thannhauser, TW and Gray, S}, title = {A comparison of protein extraction methods suitable for gel-based proteomic studies of aphid proteins.}, journal = {Journal of biomolecular techniques : JBT}, volume = {20}, number = {4}, pages = {201-215}, pmid = {19721822}, issn = {1943-4731}, mesh = {Acetone ; Animals ; Aphids/*chemistry ; Carbocyanines/analysis ; Detergents ; Electrophoresis, Gel, Two-Dimensional/methods ; Electrophoresis, Polyacrylamide Gel/*methods ; Female ; Fluorescent Dyes/analysis ; Insect Proteins/analysis/*isolation &amp; purification ; Mass Spectrometry ; Phenol ; Proteomics/*methods ; Tissue Extracts/analysis ; Trichloroacetic Acid ; }, abstract = {Protein extraction methods can vary widely in reproducibility and in representation of the total proteome, yet there are limited data comparing protein isolation methods. The methodical comparison of protein isolation methods is the first critical step for proteomic studies. To address this, we compared three methods for isolation, purification, and solubilization of insect proteins. The aphid Schizaphis graminum, an agricultural pest, was the source of insect tissue. Proteins were extracted using TCA in acetone (TCA-acetone), phenol, or multi-detergents in a chaotrope solution. Extracted proteins were solubilized in a multiple chaotrope solution and examined using 1-D and 2-D electrophoresis and compared directly using 2-D Difference Gel Electrophoresis (2-D DIGE). Mass spectrometry was used to identify proteins from each extraction type. We were unable to ascribe the differences in the proteins extracted to particular physical characteristics, cell location, or biological function. The TCA-acetone extraction yielded the greatest amount of protein from aphid tissues. Each extraction method isolated a unique subset of the aphid proteome. The TCA-acetone method was explored further for its quantitative reliability using 2-D DIGE. Principal component analysis showed that little of the variation in the data was a result of technical issues, thus demonstrating that the TCA-acetone extraction is a reliable method for preparing aphid proteins for a quantitative proteomics experiment. These data suggest that although the TCA-acetone method is a suitable method for quantitative aphid proteomics, a combination of extraction approaches is recommended for increasing proteome coverage when using gel-based separation techniques.}, }
@article {pmid19717453, year = {2009}, author = {Clements, A and Bursac, D and Gatsos, X and Perry, AJ and Civciristov, S and Celik, N and Likic, VA and Poggio, S and Jacobs-Wagner, C and Strugnell, RA and Lithgow, T}, title = {The reducible complexity of a mitochondrial molecular machine.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, number = {37}, pages = {15791-15795}, pmid = {19717453}, issn = {1091-6490}, support = {R01 GM065835/GM/NIGMS NIH HHS/United States ; R01 GM076698/GM/NIGMS NIH HHS/United States ; GM076698/GM/NIGMS NIH HHS/United States ; GM065835/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacterial Proteins/chemistry/*genetics/*metabolism ; Carrier Proteins/genetics/metabolism ; Caulobacter crescentus/genetics/metabolism ; Humans ; Membrane Proteins/genetics/metabolism ; Mitochondrial Membrane Transport Proteins/chemistry/*genetics/*metabolism ; Mitochondrial Precursor Protein Import Complex Proteins ; Mitochondrial Proteins/genetics/metabolism ; Models, Molecular ; Protein Conformation ; Protein Structure, Tertiary ; Saccharomyces cerevisiae Proteins/genetics/metabolism ; Species Specificity ; }, abstract = {Molecular machines drive essential biological processes, with the component parts of these machines each contributing a partial function or structural element. Mitochondria are organelles of eukaryotic cells, and depend for their biogenesis on a set of molecular machines for protein transport. How these molecular machines evolved is a fundamental question. Mitochondria were derived from an alpha-proteobacterial endosymbiont, and we identified in alpha-proteobacteria the component parts of a mitochondrial protein transport machine. In bacteria, the components are found in the inner membrane, topologically equivalent to the mitochondrial proteins. Although the bacterial proteins function in simple assemblies, relatively little mutation would be required to convert them to function as a protein transport machine. This analysis of protein transport provides a blueprint for the evolution of cellular machinery in general.}, }
@article {pmid19710065, year = {2009}, author = {Koop, JL and Zeh, DW and Bonilla, MM and Zeh, JA}, title = {Reproductive compensation favours male-killing Wolbachia in a live-bearing host.}, journal = {Proceedings. Biological sciences}, volume = {276}, number = {1675}, pages = {4021-4028}, pmid = {19710065}, issn = {0962-8452}, mesh = {Animals ; Arachnida/genetics/*microbiology/*physiology ; Female ; Hydrogen-Ion Concentration ; Male ; Phylogeny ; Reproduction/physiology ; Sex Ratio ; Wolbachia/*classification ; }, abstract = {Wolbachia are maternally inherited, cellular endosymbionts that can enhance their fitness by biasing host sex ratio in favour of females. Male killing (MK) is an extreme form of sex-ratio manipulation that is selectively advantageous if the self-sacrifice of Wolbachia in males increases transmission through females. In live-bearing hosts, females typically produce more embryos than can be carried to term, and reproductive compensation through maternal resource reallocation from dead males to female embryos could increase the number of daughters born to infected females. Here, we report a new strain of MK Wolbachia (wCsc2) in the pseudoscorpion, Cordylochernes scorpioides, and present the first empirical evidence that reproductive compensation favours the killing of males in a viviparous host. Females infected with the wCsc2 strain produced 26 per cent more and significantly larger daughters than tetracycline-cured females. In contrast to the previously described wCsc1 MK Wolbachia strain in C. scorpioides, wCsc2 infection was not accompanied by an increase in the rate of spontaneous brood abortion. Characterization of the wCsc1 and wCsc2 strains by multi-locus sequence typing and by Wolbachia surface protein (wsp) gene sequencing indicates that the marked divergence between these two MK strains in their impact on host reproductive success, and hence in their potential to spread, has occurred in association with homologous recombination in the wsp gene.}, }
@article {pmid19704881, year = {2008}, author = {Thornhill, DJ and Fielman, KT and Santos, SR and Halanych, KM}, title = {Siboglinid-bacteria endosymbiosis: A model system for studying symbiotic mechanisms.}, journal = {Communicative &amp; integrative biology}, volume = {1}, number = {2}, pages = {163-166}, pmid = {19704881}, issn = {1942-0889}, abstract = {Siboglinid worms are a group of gutless marine annelids which are nutritionally dependent upon endosymbiotic bacteria.1,2 Four major groups of siboglinids are known including vestimentiferans, Osedax spp., frenulates and moniliferans.3-5 Very little is known about the diversity of bacterial endosymbionts associated with frenulate or monoliferan siboglinids. This lack of knowledge is surprising considering the global distribution of siboglinids; this system is likely among the most common symbioses in the deep sea. At least three distinct clades of endosymbiotic gamma-proteobacteria associate with siboglinid annelids.6 Frenulates harbor a clade of gamma-proteobacteria that are divergent from both the thiotrophic bacteria of vestimentiferans and monoliferans as well as the heterotrophic bacteria of Osedax spp.6,7 We also discuss priorities for future siboglinid research and the need to move beyond descriptive studies. A promising new method, laser-capture microdissection (LCM), allows for the precise excision of tissue regions of interest.8 This method, when used in concert with molecular and genomic techniques, such as Expressed Sequence Tag (EST) surveys using pyrosequencing technology, will likely enable investigations into physiological processes and mechanisms in these symbioses. Furthermore, adopting a comparative approach using different siboglinid groups, such as worms harboring thiotrophic versus methanotrophic endosymbionts, may yield considerable insight into the ecology and evolution of the Siboglinidae.}, }
@article {pmid19698196, year = {2010}, author = {Kawasaki, Y and Ito, M and Miura, K and Kajimura, H}, title = {Superinfection of five Wolbachia in the alnus ambrosia beetle, Xylosandrus germanus (Blandford) (Coleoptera: Curuculionidae).}, journal = {Bulletin of entomological research}, volume = {100}, number = {2}, pages = {231-239}, doi = {10.1017/S000748530999023X}, pmid = {19698196}, issn = {1475-2670}, mesh = {Animals ; Coleoptera/*microbiology ; Electron Transport Complex IV/genetics ; Genes, Bacterial/genetics ; Haplotypes ; Phylogeny ; Polymorphism, Genetic ; Wolbachia/*physiology ; }, abstract = {Wolbachia bacteria are among the most common endosymbionts in insects. In Wolbachia research, the Wolbachia surface protein (wsp) gene has been used as a phylogenetic tool, but relationships inferred by single-locus analysis can be unreliable because of the extensive genome recombination among Wolbachia strains. Therefore, a multilocus sequence typing (MLST) method for Wolbachia, which relies upon a set of five conserved genes, is recommended. In this study, we examined whether the alnus ambrosia beetle, Xylosandrus germanus (Blandford), is infected with Wolbachia using wsp and MLST genes. Wolbachia was detected from all tested specimens of X. germanus (n=120) by wsp amplification. Five distinct sequences (i.e. five alleles) for wsp were found, and labeled as wXge1-5. MLST analysis and molecular phylogeny of concatenated sequences of MLST genes identified wXge3 and wXge5 as closely-related strains. The detection rate of wXge4 and wXge1 was 100% and 63.3%, respectively; wXge2, wXge3 and wXge5 were detected from less than 15% of specimens. We performed mitochondrial haplotype analyses that identified three genetic types of X. germanus, i.e. Clades A, B and C. Wsp alleles wXge1, wXge2 and wXge4 were detected in all clade A beetles; wXge2 allele was absent from Clades B and C. We concluded that (i) five wsp alleles were found from X. germanus, (ii) use of MLST genes, rather than the wsp gene, are more suited to construct Wolbachia phylogenies and (iii) wsp alleles wXge2 and wXge3/wXge5 would infect clade A and clade B/C of X. germanus, respectively.}, }
@article {pmid19698188, year = {2009}, author = {Pike, N and Kingcombe, R}, title = {Antibiotic treatment leads to the elimination of Wolbachia endosymbionts and sterility in the diplodiploid collembolan Folsomia candida.}, journal = {BMC biology}, volume = {7}, number = {}, pages = {54}, pmid = {19698188}, issn = {1741-7007}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Arthropods/chemistry/*microbiology/physiology ; Cloning, Organism ; Clutch Size/drug effects ; Denmark ; Diet ; Diploidy ; Female ; France ; Male ; Ovum/drug effects ; Parthenogenesis ; Polymerase Chain Reaction ; Reproduction/drug effects ; Rifampin/*pharmacology ; Symbiosis/*drug effects ; Tetracycline/*pharmacology ; United Kingdom ; Wolbachia/chemistry/*drug effects/physiology ; }, abstract = {BACKGROUND: Wolbachia is an extremely widespread bacterial endosymbiont of arthropods and nematodes that causes a variety of reproductive peculiarities. Parthenogenesis is one such peculiarity but it has been hypothesised that this phenomenon may be functionally restricted to organisms that employ haplodiploid sex determination. Using two antibiotics, tetracycline and rifampicin, we attempted to eliminate Wolbachia from the diplodiploid host Folsomia candida, a species of springtail which is a widely used study organism.<br><br>RESULTS: Molecular assays confirmed that elimination of Wolbachia was successfully achieved through continuous exposure of populations (over two generations and several weeks) to rifampicin administered as 2.7% dry weight of their yeast food source. The consequence of this elimination was total sterility of all individuals, despite the continuation of normal egg production.<br><br>CONCLUSION: Microbial endosymbionts play an obligatory role in the reproduction of their diplodiploid host, most likely one in which the parthenogenetic process is facilitated by Wolbachia. A hitherto unknown level of host-parasite interdependence is thus recorded.}, }
@article {pmid19695326, year = {2009}, author = {Narayanan, N and Krishnakumar, B and Anupama, VN and Manilal, VB}, title = {Methanosaeta sp., the major archaeal endosymbiont of Metopus es.}, journal = {Research in microbiology}, volume = {160}, number = {8}, pages = {600-607}, doi = {10.1016/j.resmic.2009.07.011}, pmid = {19695326}, issn = {1769-7123}, mesh = {Acetates/metabolism ; Animals ; Ciliophora/*microbiology/*physiology ; Humans ; In Situ Hybridization, Fluorescence ; Methane/metabolism ; Methanosarcinales/cytology/*isolation &amp; purification/*physiology ; Microscopy, Fluorescence ; *Symbiosis ; }, abstract = {Epifluorescence microscopy and whole cell in situ hybridization analysis revealed the presence of Methanosaeta sp. as endosymbionts in Metopus es. Direct microscopic observation under epifluorescent microscope showed the presence of long slender rods with an average length of 3.4 microm. The number of methanogenic rods varied from 792 +/- 12 in a single M. es cell with a biovolume of 3.4 x 10(5) microm(3). At the exponential growth stage, a single symbiotic methanogen in M. es produced about 1 fmol methane/h leading to a methane production rate of 0.85 pmol/ciliate/h. The presence of endosymbiotic methanogens in the domain archaea and Methanosaeta sp. was confirmed by FISH with ARCH 915 and MX 825 oligonucleotide probes specific to domain archaea and Methanosaeta respectively. The homogenized cells of M. es also showed bright fluorescing rods with MX 825 hybridization. The culture obtained on inoculation of the released endosymbiotic organisms on Methanosaeta-specific medium lent support to the growth of long slender rods having the same range of mean length (3.6 microm) as that of the endosymbiotic methanogens observed. Both intra- and extracellular production of acetate was detected in M. es culture.}, }
@article {pmid19693078, year = {2009}, author = {Lake, JA}, title = {Evidence for an early prokaryotic endosymbiosis.}, journal = {Nature}, volume = {460}, number = {7258}, pages = {967-971}, pmid = {19693078}, issn = {1476-4687}, mesh = {Actinobacteria/*cytology ; *Biological Evolution ; Clostridium/*cytology ; *Endocytosis ; Eukaryotic Cells/cytology ; Gene Flow ; *Models, Biological ; Phylogeny ; Prokaryotic Cells/classification/*cytology ; *Symbiosis ; }, abstract = {Endosymbioses have dramatically altered eukaryotic life, but are thought to have negligibly affected prokaryotic evolution. Here, by analysing the flows of protein families, I present evidence that the double-membrane, gram-negative prokaryotes were formed as the result of a symbiosis between an ancient actinobacterium and an ancient clostridium. The resulting taxon has been extraordinarily successful, and has profoundly altered the evolution of life by providing endosymbionts necessary for the emergence of eukaryotes and by generating Earth's oxygen atmosphere. Their double-membrane architecture and the observed genome flows into them suggest a common evolutionary mechanism for their origin: an endosymbiosis between a clostridium and actinobacterium.}, }
@article {pmid19692410, year = {2009}, author = {Ikeya, T and Broughton, S and Alic, N and Grandison, R and Partridge, L}, title = {The endosymbiont Wolbachia increases insulin/IGF-like signalling in Drosophila.}, journal = {Proceedings. Biological sciences}, volume = {276}, number = {1674}, pages = {3799-3807}, pmid = {19692410}, issn = {0962-8452}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Drosophila melanogaster/*metabolism/*microbiology ; Fat Body/metabolism ; Gene Expression Regulation ; Insulin/*metabolism ; Mutation ; Signal Transduction ; Somatomedins/*metabolism ; Wolbachia/*physiology ; }, abstract = {Insulin/IGF-like signalling (IIS) is an evolutionarily conserved pathway that has diverse functions in multi-cellular organisms. Mutations that reduce IIS can have pleiotropic effects on growth, development, metabolic homeostasis, fecundity, stress resistance and lifespan. IIS is also modified by extrinsic factors. For instance, in the fruitfly Drosophila melanogaster, both nutrition and stress can alter the activity of the pathway. Here, we test experimentally the hypothesis that a widespread endosymbiont of arthropods, Wolbachia pipientis, can alter the degree to which mutations in genes encoding IIS components affect IIS and its resultant phenotypes. Wolbachia infection, which is widespread in D. melanogaster in nature and has been estimated to infect 30 per cent of strains in the Bloomington stock centre, can affect broad aspects of insect physiology, particularly traits associated with reproduction. We measured a range of IIS-related phenotypes in flies ubiquitously mutant for IIS in the presence and absence of Wolbachia. We show that removal of Wolbachia further reduces IIS and hence enhances the mutant phenotypes, suggesting that Wolbachia normally acts to increase insulin signalling. This effect of Wolbachia infection on IIS could have an evolutionary explanation, and has some implications for studies of IIS in Drosophila and other organisms that harbour endosymbionts.}, }
@article {pmid19692404, year = {2009}, author = {Aikawa, T and Anbutsu, H and Nikoh, N and Kikuchi, T and Shibata, F and Fukatsu, T}, title = {Longicorn beetle that vectors pinewood nematode carries many Wolbachia genes on an autosome.}, journal = {Proceedings. Biological sciences}, volume = {276}, number = {1674}, pages = {3791-3798}, pmid = {19692404}, issn = {0962-8452}, mesh = {Animals ; Coleoptera/*microbiology/*parasitology ; Female ; Genes, Bacterial ; Genome, Insect ; Male ; Nematoda/*physiology ; Phylogeny ; Wolbachia/*genetics ; }, abstract = {Monochamus alternatus is the longicorn beetle notorious as a vector of the pinewood nematode that causes the pine wilt disease. When two populations of M. alternatus were subjected to diagnostic polymerase chain reaction (PCR) detection of four Wolbachia genes, only the ftsZ gene was detected from one of the populations. The Wolbachia ftsZ gene persisted even after larvae were fed with a tetracycline-containing diet for six weeks. The inheritance of the ftsZ gene was not maternal but biparental, exhibiting a typical Mendelian pattern. The ftsZ gene titres in homozygotic ftsZ(+) insects were nearly twice as high as those in heterozygotic ftsZ(+) insects. Exhaustive PCR surveys revealed that 31 and 30 of 214 Wolbachia genes examined were detected from the two insect populations, respectively. Many of these Wolbachia genes contained stop codon(s) and/or frame shift(s). Fluorescent in situ hybridization confirmed the location of the Wolbachia genes on an autosome. On the basis of these results, we conclude that a large Wolbachia genomic region has been transferred to and located on an autosome of M. alternatus. The discovery of massive gene transfer from Wolbachia to M. alternatus would provide further insights into the evolution and fate of laterally transferred endosymbiont genes in multicellular host organisms.}, }
@article {pmid19686079, year = {2009}, author = {Moore, CE and Archibald, JM}, title = {Nucleomorph genomes.}, journal = {Annual review of genetics}, volume = {43}, number = {}, pages = {251-264}, doi = {10.1146/annurev-genet-102108-134809}, pmid = {19686079}, issn = {1545-2948}, support = {//Canadian Institutes of Health Research/Canada ; }, mesh = {Chlorophyta/genetics ; Cryptophyta/classification/cytology/*genetics ; Eukaryota/classification/cytology/*genetics ; *Genome ; Rhodophyta/genetics ; }, abstract = {Nucleomorphs are the remnant nuclei of algal endosymbionts in cryptophytes and chlorarachniophytes, two evolutionarily distinct unicellular eukaryotic lineages that acquired photosynthesis secondarily by the engulfment of red and green algae, respectively. At less than one million base pairs in size, nucleomorph genomes are the most highly reduced nuclear genomes known, with three small linear chromosomes and a gene density similar to that seen in prokaryotes. The independent origin of nucleomorphs in cryptophytes and chlorarachniophytes presents an interesting opportunity to study the reductive evolutionary forces that have led to their remarkable convergence upon similar genome architectures and coding capacities. In this article, we review the current state of knowledge with respect to the structure, function, origin, and evolution of nucleomorph genomes across the known diversity of cryptophyte and chlorarachniophyte algae.}, }
@article {pmid19663639, year = {2009}, author = {Matsuura, Y and Koga, R and Nikoh, N and Meng, XY and Hanada, S and Fukatsu, T}, title = {Huge symbiotic organs in giant scale insects of the genus Drosicha (Coccoidea: Monophlebidae) harbor flavobacterial and enterobacterial endosymbionts.}, journal = {Zoological science}, volume = {26}, number = {7}, pages = {448-456}, doi = {10.2108/zsj.26.448}, pmid = {19663639}, issn = {0289-0003}, mesh = {Animals ; Enterobacteriaceae/genetics/*isolation &amp; purification/ultrastructure ; Flavobacteriaceae/genetics/*isolation &amp; purification/ultrastructure ; Hemiptera/*anatomy &amp; histology/*microbiology ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*physiology ; }, abstract = {Giant scale insects (Drosicha: Coccoldea: Monophlebidae) were investigated for their symbiotic organs and bacterial endosymbionts. Two types of bacterial 16S rRNA gene sequences, flavobacterial and enterobacterial, were consistently detected in D. corpulenta and D. pinicola. The former sequences formed a compact clade in the Bacteroidetes, allied to the symbionts of cushion and armored scales. The latter sequences formed a robust clade in the gamma-Proteobacteria, allied to enteric bacteria like Enterobacter aerogenes and Escherichia coli. Another type of 16S sequence derived from Wolbachia was also detected in D. pinicola. In-situ hybridization demonstrated that the flavobacterial and enterobacterial symbionts were localized in a pair of huge bacteriomes in the abdomen, the former in uninucleated peripheral bacteriocytes and the latter in syncytial central bacteriocytes. Electron microscopy confirmed the endocellular locations of the pleomorphic flavobacterial symbiont and the rod-shaped enterobacterial symbiont, and also revealed the location and fine structure of the Wolbachia symbiont in D. pinicola. Infection frequencies of the flavobacterial and enterobacterial symbionts were consistently 100% in populations of D. corpulenta and D. pinicola, while the Wolbachia symbiont exhibited 0% and 100% infection frequencies in D. corpulente and D. pinicola, respectively. Neither the flavobacterial symbiont nor the enterobacterial symbiont exhibited AT-biased nucleotide composition or accelerated molecular evolution. The huge bacteriomes of Drosicha giant scales would provide a useful system for investigating biochemical, physiological, and genomic aspects of the host-symbiont and symbiont-symbiont interactions.}, }
@article {pmid19656046, year = {2009}, author = {Maclean, AM and White, CE and Fowler, JE and Finan, TM}, title = {Identification of a hydroxyproline transport system in the legume endosymbiont Sinorhizobium meliloti.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {22}, number = {9}, pages = {1116-1127}, doi = {10.1094/MPMI-22-9-1116}, pmid = {19656046}, issn = {0894-0282}, mesh = {Bacterial Proteins/genetics/metabolism ; Base Sequence ; Biological Transport/drug effects ; Fabaceae/drug effects/metabolism/*microbiology ; Gene Expression Regulation, Bacterial/drug effects ; Genes, Bacterial ; Hydroxyproline/*metabolism/pharmacology ; Immunohistochemistry ; Medicago sativa/cytology/drug effects/metabolism/microbiology ; Molecular Sequence Data ; Multigene Family ; Phylogeny ; Promoter Regions, Genetic/genetics ; Root Nodules, Plant/cytology/drug effects/metabolism/microbiology ; Sinorhizobium meliloti/drug effects/genetics/growth &amp; development/*metabolism ; *Symbiosis ; Transcription Initiation Site ; }, abstract = {Hydroxyproline-rich proteins in plants offer a source of carbon and nitrogen to soil-dwelling microorganisms in the form of root exudates and decaying organic matter. This report describes an ABC-type transport system dedicated to the uptake of hydroxyproline in the legume endosymbiont Sinorhizobium meliloti. We have designated genes involved in hydroxyproline metabolism as hyp genes and show that an S. meliloti strain lacking putative transport genes (DeltahypMNPQ) is unable to grow with or transport trans-4-hydroxy-l-proline when this compound is available as a sole source of carbon. Expression of hypM is upregulated in the presence of trans-4-hydroxy-l-proline and cis-4-hydroxy-d-proline, as modulated by a repressor (HypR) of the GntR/FadR subfamily. Although alfalfa root nodules contain hydroxyproline-rich proteins, we demonstrate that the transport system is not highly expressed in nodules, suggesting that bacteroids are not exposed to high levels of free hydroxyproline in planta. In addition to hypMNPQ, we report that S. meliloti encodes a second independent mechanism that enables transport of trans-4-hydroxy-l-proline. This secondary transport mechanism is induced in proline-grown cells and likely entails a system involved in l-proline uptake. This study represents the first genetic description of a prokaryotic hydroxyproline transport system, and the ability to metabolize hydroxyproline may contribute significantly toward the ecological success of plant-associated bacteria such as the rhizobia.}, }
@article {pmid19647785, year = {2010}, author = {Takano, H and Takechi, K}, title = {Plastid peptidoglycan.}, journal = {Biochimica et biophysica acta}, volume = {1800}, number = {2}, pages = {144-151}, doi = {10.1016/j.bbagen.2009.07.020}, pmid = {19647785}, issn = {0006-3002}, mesh = {Arabidopsis/enzymology/genetics ; Bryopsida/genetics ; Gene Expression Regulation, Plant ; *Genes, Plant ; Peptidoglycan/*biosynthesis ; Plastids/*genetics/*metabolism ; }, abstract = {It is now widely accepted that an endosymbiotic cyanobacterium evolved into the plastid of the primary photosynthetic eukaryotes: glaucocystophytes, red algae, and green plants. It has been thought that during the evolution of plants, the peptidoglycan wall (or murein) was lost from the endosymbiont immediately after the branching off of the glaucocystophytes, which have peptidoglycan-armed plastids termed cyanelles. However, we found that the moss Physcomitrella patens has all of the genes for peptidoglycan biosynthesis with the exception of one racemase. The aim of the present review is to summarize recent findings on plastid peptidoglycan and to present a hypothesis for the evolution of plastids containing peptidoglycan. Gene knockout experiments for the Mur(ein) genes, including MurE in P. patens, showed that the peptidoglycan synthesis pathway is related to plastid division, although no structure can be detected between the inner and outer envelopes of the chloroplasts by electron microscopy. On the other hand, MurE in Arabidopsis thaliana has a function in plastid gene expression and not in division. Based on data regarding plant genomes and antibiotic treatment experiments of plastid division, we propose that the loss of peptidoglycan occurred independently at least three times during plant evolution: from the lineage of red algae, from the chlorophytes, and during land plant evolution.}, }
@article {pmid19640319, year = {2009}, author = {Smith, DT and Hosken, DJ and Ffrench-Constant, RH and Wedell, N}, title = {Variation in sex peptide expression in D. melanogaster.}, journal = {Genetics research}, volume = {91}, number = {4}, pages = {237-242}, doi = {10.1017/S0016672309000226}, pmid = {19640319}, issn = {1469-5073}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Drosophila Proteins/*genetics ; Drosophila melanogaster/*genetics/microbiology/physiology ; Female ; *Gene Expression Profiling ; *Genetic Variation ; Host-Pathogen Interactions ; Male ; Peptides/*genetics ; Regression Analysis ; Reverse Transcriptase Polymerase Chain Reaction ; Sexual Behavior, Animal ; Species Specificity ; Wolbachia/physiology ; }, abstract = {Male Drosophila melanogaster transfers many accessory-gland proteins to females during copulation. Sex peptide (SP) is one of these and one of its main effects is to decrease female remating propensity. To date, there has been no investigation of genetic variation in SP-gene expression levels, or if such potential variation directly influences female remating behaviour. We assessed both these possibilities and found significant variation in expression levels of the SP gene across D. melanogaster isolines. A non-linear association between SP expression levels and female remating delay suggestive of disruptive selection on expression levels was also documented. Finally, while some isolines were infected with the endosymbiont Wolbachia, no association between Wolbachia and SP expression level was found.}, }
@article {pmid19633116, year = {2009}, author = {Stewart, FJ and Baik, AH and Cavanaugh, CM}, title = {Genetic subdivision of chemosynthetic endosymbionts of Solemya velum along the Southern New England coast.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {18}, pages = {6005-6007}, pmid = {19633116}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*genetics/isolation &amp; purification ; Bivalvia/*classification/*genetics/microbiology/physiology ; DNA, Mitochondrial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; *Genetic Variation ; Molecular Sequence Data ; New England ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Population-level genetic diversity in the obligate symbiosis between the bivalve Solemya velum and its thioautotrophic bacterial endosymbiont was examined. Distinct populations along the New England coast shared a single mitochondrial genotype but were fixed for unique symbiont genotypes, indicating high levels of symbiont genetic structuring and potential symbiont-host decoupling.}, }
@article {pmid19627494, year = {2009}, author = {Abrego, D and VAN Oppen, MJ and Willis, BL}, title = {Onset of algal endosymbiont specificity varies among closely related species of Acropora corals during early ontogeny.}, journal = {Molecular ecology}, volume = {18}, number = {16}, pages = {3532-3543}, doi = {10.1111/j.1365-294X.2009.04276.x}, pmid = {19627494}, issn = {1365-294X}, mesh = {Animals ; Anthozoa/*growth &amp; development ; Dinoflagellida/*genetics ; Ecosystem ; Life Cycle Stages ; Species Specificity ; *Symbiosis ; Time Factors ; }, abstract = {Juveniles of a number of corals with horizontal transmission of dinoflagellate endosymbionts naturally acquire and maintain Symbiodinium types that differ from those found in adult populations. However, the duration of this early period of symbiont flexibility and successional changes leading to dominance by the characteristic adult (homologous) type are unknown. To document natural succession of Symbiodinium types within juvenile corals, we monitored Symbiodinium communities in juveniles of Acropora tenuis and Acropora millepora for 3.5 years. Juveniles originating from one of three reef populations, characterized by differing adult coral-Symbiodinium associations, were raised in a common environment. In four out of five cases, juveniles became dominated initially by a nonhomologous adult type. Changes in Symbiodinium communities associated with A. tenuis juveniles led to the establishment of the adult homologous association at approximately 3.5 years of age. These changes were not linked to the onset of reproductive maturity, but may be linked to micro-environmental changes associated with vertical growth of juvenile corals. We hypothesize that fine-tuning of specificity mechanisms takes place during ontogeny in A. tenuis, leading to the eventual establishment of the adult homologous association. However, Symbiodinium communities in A. millepora juveniles did not change significantly over the 3.5 years, potentially reflecting (i) lack of specificity, (ii) more than a 3.5-year delay in the onset of specificity, or (iii) lack of availability of the adult Symbiodinium type. This study demonstrates that juvenile corals may survive for extended periods of time with nonhomologous Symbiodinium types and that closely related species of Acropora differ in the timing of the onset of specificity for algal symbionts.}, }
@article {pmid19617710, year = {2009}, author = {Mao, C and Bhardwaj, K and Sharkady, SM and Fish, RI and Driscoll, T and Wower, J and Zwieb, C and Sobral, BW and Williams, KP}, title = {Variations on the tmRNA gene.}, journal = {RNA biology}, volume = {6}, number = {4}, pages = {355-361}, doi = {10.4161/rna.6.4.9172}, pmid = {19617710}, issn = {1555-8584}, support = {GM59881/GM/NIGMS NIH HHS/United States ; }, mesh = {Betaproteobacteria/genetics ; Chromosomes, Bacterial/genetics ; Cyanobacteria/genetics ; Genes, Bacterial/genetics ; Interspersed Repetitive Sequences/genetics ; Introns/genetics ; Phylogeny ; RNA, Bacterial/chemistry/*genetics ; Rickettsia/genetics ; Sinorhizobium/*genetics ; Symbiosis/genetics ; }, abstract = {tmRNA employs both tRNA-like and mRNA-like properties as it rescues stalled bacterial ribosomes, while targeting the defective mRNA and incomplete nascent protein for degradation. We describe variation of the tmRNA gene (ssrA) and how it informs tmRNA structure and function. Endosymbiont tmRNAs tend to lose secondary structure and length in the mRNA-like region as nucleotide composition drifts with that of the whole genome. A dramatic gene structure variation is circular permutation, which produces two-piece tmRNAs in three bacterial lineages; new sequences blur these lineages. We present evidence that Sinorhizobium two-piece tmRNA retains the 5'-triphosphate of transcriptional initiation and predict a new structure at the 5' end of cyanobacterial two-piece tmRNA precursor. ssrA is a target for some mobile DNAs and a passenger on others. It has been found interrupted (but not functionally disrupted) by mobile elements such as group I introns, genomic islands and palindromic elements. The alphaproteobacterial permuted genes are significantly less frequently interrupted by genomic islands than are their standard counterparts, yet are a hotspot for insertion or swapping of rickettsial palindromic elements, in contrast to other rickettsial loci that show steady decay of a single ancestral element. Bacteriophages, plasmids and genomic islands can carry tmRNA genes; we describe a native bacterial ssrA disrupted by insertion of a genomic island that carries its own ssrA, a genome encoding both one- and two-piece tmRNA, and a phage encoding a tmRNA variant lacking the mRNA-like function, which may counteract host tmRNA during infection.}, }
@article {pmid19617523, year = {2009}, author = {Archibald, JM and Lane, CE}, title = {Going, going, not quite gone: nucleomorphs as a case study in nuclear genome reduction.}, journal = {The Journal of heredity}, volume = {100}, number = {5}, pages = {582-590}, doi = {10.1093/jhered/esp055}, pmid = {19617523}, issn = {1465-7333}, mesh = {Cell Nucleus/*genetics ; Chromosomes/chemistry ; Cryptophyta/*genetics ; Evolution, Molecular ; Genome ; Plastids/*genetics ; Symbiosis/genetics ; }, abstract = {Nucleomorphs are the relic nuclei of algal endosymbionts that became permanent fixtures inside nonphotosynthetic eukaryotic host cells. These unusual organelles exist in only 2 lineages, the cryptophytes, which possess nucleomorphs and plastids (chloroplasts) derived from the uptake of a red algal endosymbiont, and the chlorarachniophytes, which harbor green algal derived nucleomorphs and plastids. Despite having evolved independently of one another, the nucleomorph genomes of cryptophytes and chlorarachniophytes are strikingly similar in size and basic structure. Both are <1 Mbp in size-the smallest nuclear genomes known-and are composed of only 3 chromosomes, each with its own subtelomeric rDNA repeats. Nucleomorph-containing algae thus represent an interesting system in which to study genome and chromosome evolution in eukaryotes. Here, we provide an overview of nucleomorph genome biology and focus on new information gleaned from comparisons of complete nucleomorph genome sequences, both within and between cryptophytes and chlorarachniophytes. Such comparisons provide fascinating insight into the evolution of these highly derived organelles and, more generally, the potential causes and consequences of genome reduction in eukaryotes.}, }
@article {pmid19608593, year = {2009}, author = {Weinert, LA and Welch, JJ and Jiggins, FM}, title = {Conjugation genes are common throughout the genus Rickettsia and are transmitted horizontally.}, journal = {Proceedings. Biological sciences}, volume = {276}, number = {1673}, pages = {3619-3627}, pmid = {19608593}, issn = {0962-8452}, mesh = {Animals ; Arthropods/microbiology ; Conjugation, Genetic/*genetics ; Gene Expression Regulation, Bacterial ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Genome, Bacterial ; Phylogeny ; Rickettsia/*genetics ; Synteny ; }, abstract = {Rickettsia are endosymbionts of arthropods, some of which are vectored to vertebrates where they cause disease. Recently, it has been found that some Rickettsia strains harbour conjugative plasmids and others encode some conjugative machinery within the bacterial genome. We investigated the distribution of these conjugation genes in a phylogenetically diverse collection of Rickettsia isolated from arthropods. We found that these genes are common throughout the genus and, in stark contrast to other genes in the genome, conjugation genes are frequently horizontally transmitted between strains. There is no evidence to suggest that these genes are preferentially transferred between phylogenetically related strains, which is surprising given that closely related strains infect similar host species. In addition to detecting patterns of horizontal transmission between diverse Rickettsia species, these findings have implications for the evolution of pathogenicity, the evolution of Rickettsia genomes and the genetic manipulation of intracellular bacteria.}, }
@article {pmid19603151, year = {2009}, author = {Alvarez-Martínez, ER and Valverde, A and Ramírez-Bahena, MH and García-Fraile, P and Tejedor, C and Mateos, PF and Santillana, N and Zúñiga, D and Peix, A and Velázquez, E}, title = {The analysis of core and symbiotic genes of rhizobia nodulating Vicia from different continents reveals their common phylogenetic origin and suggests the distribution of Rhizobium leguminosarum strains together with Vicia seeds.}, journal = {Archives of microbiology}, volume = {191}, number = {8}, pages = {659-668}, doi = {10.1007/s00203-009-0495-6}, pmid = {19603151}, issn = {1432-072X}, mesh = {Bacterial Proteins/genetics ; DNA Fingerprinting ; DNA, Bacterial/genetics ; DNA, Ribosomal Spacer/genetics ; *Evolution, Molecular ; Geography ; N-Acetylglucosaminyltransferases/genetics ; *Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Rhizobium leguminosarum/classification/*genetics ; Root Nodules, Plant/microbiology ; Seeds/microbiology ; Sequence Analysis, DNA ; Soil Microbiology ; Spain ; Symbiosis/*genetics ; Vicia/*microbiology ; }, abstract = {In this work, we analysed the core and symbiotic genes of rhizobial strains isolated from Vicia sativa in three soils from the Northwest of Spain, and compared them with other Vicia endosymbionts isolated in other geographical locations. The analysis of rrs, recA and atpD genes and 16S-23S rRNA intergenic spacer showed that the Spanish strains nodulating V. sativa are phylogenetically close to those isolated from V. sativa and V. faba in different European, American and Asian countries forming a group related to Rhizobium leguminosarum. The analysis of the nodC gene of strains nodulating V. sativa and V. faba in different continents showed they belong to a phylogenetically compact group indicating that these legumes are restrictive hosts. The results of the nodC gene analysis allow the delineation of the biovar viciae showing a common phylogenetic origin of V. sativa and V. faba endosymbionts in several continents. Since these two legume species are indigenous from Europe, our results suggest a world distribution of strains from R. leguminosarum together with the V. sativa and V. faba seeds and a close coevolution among chromosome, symbiotic genes and legume host in this Rhizobium-Vicia symbiosis.}, }
@article {pmid19602081, year = {2009}, author = {Visvesvara, GS and Sriram, R and Qvarnstrom, Y and Bandyopadhyay, K and Da Silva, AJ and Pieniazek, NJ and Cabral, GA}, title = {Paravahlkampfia francinae n. sp. masquerading as an agent of primary amoebic meningoencephalitis.}, journal = {The Journal of eukaryotic microbiology}, volume = {56}, number = {4}, pages = {357-366}, doi = {10.1111/j.1550-7408.2009.00410.x}, pmid = {19602081}, issn = {1550-7408}, support = {5P30 NS047463/NS/NINDS NIH HHS/United States ; }, mesh = {Adolescent ; Amphotericin B/administration &amp; dosage ; Animals ; Antiprotozoal Agents/administration &amp; dosage ; Central Nervous System Protozoal Infections/*parasitology ; DNA, Protozoan/analysis/genetics ; Genes, rRNA ; Humans ; Male ; Mice ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Protozoan Infections/*parasitology ; Schizopyrenida/drug effects/*pathogenicity/*physiology/*ultrastructure ; Species Specificity ; Virulence ; }, abstract = {Paravahlkampfia francinae n. sp., a new species of the free-living amoeba genus Paravahlkampfia, designated as CDC:V595, was isolated from the cerebrospinal fluid of a patient with headache, sore throat, and vomiting, typical symptoms of primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri. The isolate grew at 33 degrees C, 37 degrees C, 40 degrees C, and 42 degrees C and destroyed mammalian cell cultures. However, it did not kill young mice upon intranasal inoculation. P. francinae does not produce flagellates and does not grow on agar plates coated with Gram-negative bacteria such as Escherichia coli, the usual food source of Paravahlkampfia ustiana, the type species of the genus. The trophozoite at light microscopy exhibited eruptive locomotion and possessed a single vesicular nucleus. Ultrastructurally, the trophozoites had numerous mitochondria with discoidal cristae but did not have a Golgi apparatus. The trophozoites differentiated into cysts after consuming most of the monolayer. The cyst had an inner well-differentiated endocyst and an outer thin, wrinkled, and wavy ectocyst with no pores. During excystation trophozoites ruptured the cyst wall and emerged from the cysts. A unique feature seen in the cysts was the presence of bacterial endosymbionts, both in the endoplasm and within the cyst wall. Full-length sequencing analysis of the 18S and 5.8S RNA genes of P. francinae showed that they were distinct from those of other Paravahlkampfia species. The patient recovered within a few days indicating that some of the previously reported cases of PAM that survived may have been due to P. francinae.}, }
@article {pmid19597542, year = {2009}, author = {Wu, B and Novelli, J and Foster, J and Vaisvila, R and Conway, L and Ingram, J and Ganatra, M and Rao, AU and Hamza, I and Slatko, B}, title = {The heme biosynthetic pathway of the obligate Wolbachia endosymbiont of Brugia malayi as a potential anti-filarial drug target.}, journal = {PLoS neglected tropical diseases}, volume = {3}, number = {7}, pages = {e475}, pmid = {19597542}, issn = {1935-2735}, support = {R01 DK074797/DK/NIDDK NIH HHS/United States ; R01 DK074797-01/DK/NIDDK NIH HHS/United States ; DK074797/DK/NIDDK NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/antagonists &amp; inhibitors/genetics ; Biosynthetic Pathways/*drug effects/genetics ; Brugia malayi/*growth &amp; development/*microbiology/physiology ; Cloning, Molecular ; Cluster Analysis ; Drug Evaluation, Preclinical/methods ; Enzyme Inhibitors/pharmacology ; Escherichia coli/drug effects/genetics ; Female ; Genetic Complementation Test ; Heme/*biosynthesis/genetics ; Humans ; Locomotion ; Male ; Phylogeny ; Sequence Homology ; Wolbachia/*drug effects/isolation &amp; purification/*metabolism ; }, abstract = {BACKGROUND: Filarial parasites (e.g., Brugia malayi, Onchocerca volvulus, and Wuchereria bancrofti) are causative agents of lymphatic filariasis and onchocerciasis, which are among the most disabling of neglected tropical diseases. There is an urgent need to develop macro-filaricidal drugs, as current anti-filarial chemotherapy (e.g., diethylcarbamazine [DEC], ivermectin and albendazole) can interrupt transmission predominantly by killing microfilariae (mf) larvae, but is less effective on adult worms, which can live for decades in the human host. All medically relevant human filarial parasites appear to contain an obligate endosymbiotic bacterium, Wolbachia. This alpha-proteobacterial mutualist has been recognized as a potential target for filarial nematode life cycle intervention, as antibiotic treatments of filarial worms harboring Wolbachia result in the loss of worm fertility and viability upon antibiotic treatments both in vitro and in vivo. Human trials have confirmed this approach, although the length of treatments, high doses required and medical counter-indications for young children and pregnant women warrant the identification of additional anti-Wolbachia drugs.<br><br>METHODS AND FINDINGS: Genome sequence analysis indicated that enzymes involved in heme biosynthesis might constitute a potential anti-Wolbachia target set. We tested different heme biosynthetic pathway inhibitors in ex vivo B. malayi viability assays and report a specific effect of N-methyl mesoporphyrin (NMMP), which targets ferrochelatase (FC, the last step). Our phylogenetic analysis indicates evolutionarily significant divergence between Wolbachia heme genes and their human homologues. We therefore undertook the cloning, overexpression and analysis of several enzymes of this pathway alongside their human homologues, and prepared proteins for drug targeting. In vitro enzyme assays revealed a approximately 600-fold difference in drug sensitivities to succinyl acetone (SA) between Wolbachia and human 5'-aminolevulinic acid dehydratase (ALAD, the second step). Similarly, Escherichia coli hemH (FC) deficient strains transformed with human and Wolbachia FC homologues showed significantly different sensitivities to NMMP. This approach enables functional complementation in E. coli heme deficient mutants as an alternative E. coli-based method for drug screening.<br><br>CONCLUSIONS: Our studies indicate that the heme biosynthetic genes in the Wolbachia of B. malayi (wBm) might be essential for the filarial host survival. In addition, the results suggest they are likely candidate drug targets based upon significant differences in phylogenetic distance, biochemical properties and sensitivities to heme biosynthesis inhibitors, as compared to their human homologues.}, }
@article {pmid19592535, year = {2009}, author = {Tanaka, K and Furukawa, S and Nikoh, N and Sasaki, T and Fukatsu, T}, title = {Complete WO phage sequences reveal their dynamic evolutionary trajectories and putative functional elements required for integration into the Wolbachia genome.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {17}, pages = {5676-5686}, pmid = {19592535}, issn = {1098-5336}, mesh = {Bacteriophages/*genetics/physiology ; DNA, Viral/*chemistry/genetics ; Evolution, Molecular ; Gene Order ; *Genome, Viral ; Molecular Sequence Data ; Phylogeny ; Prophages/*genetics/physiology ; *Sequence Analysis, DNA ; Sequence Homology ; Viral Proteins/genetics/physiology ; Virus Integration ; Wolbachia/*virology ; }, abstract = {Wolbachia endosymbionts are ubiquitously found in diverse insects including many medical and hygienic pests, causing a variety of reproductive phenotypes, such as cytoplasmic incompatibility, and thereby efficiently spreading in host insect populations. Recently, Wolbachia-mediated approaches to pest control and management have been proposed, but the application of these approaches has been hindered by the lack of genetic transformation techniques for symbiotic bacteria. Here, we report the genome and structure of active bacteriophages from a Wolbachia endosymbiont. From the Wolbachia strain wCauB infecting the moth Ephestia kuehniella two closely related WO prophages, WOcauB2 of 43,016 bp with 47 open reading frames (ORFs) and WOcauB3 of 45,078 bp with 46 ORFs, were characterized. In each of the prophage genomes, an integrase gene and an attachment site core sequence were identified, which are putatively involved in integration and excision of the mobile genetic elements. The 3' region of the prophages encoded genes with sequence motifs related to bacterial virulence and protein-protein interactions, which might represent effector molecules that affect cellular processes and functions of their host bacterium and/or insect. Database searches and phylogenetic analyses revealed that the prophage genes have experienced dynamic evolutionary trajectories. Genes similar to the prophage genes were found across divergent bacterial phyla, highlighting the active and mobile nature of the genetic elements. We suggest that the active WO prophage genomes and their constituent sequence elements would provide a clue to development of a genetic transformation vector for Wolbachia endosymbionts.}, }
@article {pmid19587241, year = {2009}, author = {Wang, J and Wu, Y and Yang, G and Aksoy, S}, title = {Interactions between mutualist Wigglesworthia and tsetse peptidoglycan recognition protein (PGRP-LB) influence trypanosome transmission.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, number = {29}, pages = {12133-12138}, pmid = {19587241}, issn = {1091-6490}, support = {R01 AI051584/AI/NIAID NIH HHS/United States ; 068932/WT_/Wellcome Trust/United Kingdom ; 051584//PHS HHS/United States ; 069449//PHS HHS/United States ; }, mesh = {Animals ; Carrier Proteins/genetics/*metabolism ; Fat Body/metabolism ; Female ; Gene Expression Regulation ; Homeostasis ; Immunity, Innate ; Insect Proteins/metabolism ; Parasites/physiology ; *Symbiosis ; Time Factors ; Trypanosoma/*physiology ; Tsetse Flies/immunology/*microbiology/*parasitology ; Wigglesworthia/cytology/*physiology ; }, abstract = {Tsetse flies, the sole vectors of African trypanosomes, have coevolved with mutualistic endosymbiont Wigglesworthia glossinidiae. Elimination of Wigglesworthia renders tsetse sterile and increases their trypanosome infection susceptibility. We show that a tsetse peptidoglycan recognition protein (PGRP-LB) is crucial for symbiotic tolerance and trypanosome infection processes. Tsetse pgrp-lb is expressed in the Wigglesworthia-harboring organ (bacteriome) in the midgut, and its level of expression correlates with symbiont numbers. Adult tsetse cured of Wigglesworthia infections have significantly lower pgrp-lb levels than corresponding normal adults. RNA interference (RNAi)-mediated depletion of pgrp-lb results in the activation of the immune deficiency (IMD) signaling pathway and leads to the synthesis of antimicrobial peptides (AMPs), which decrease Wigglesworthia density. Depletion of pgrp-lb also increases the host's susceptibility to trypanosome infections. Finally, parasitized adults have significantly lower pgrp-lb levels than flies, which have successfully eliminated trypanosome infections. When both PGRP-LB and IMD immunity pathway functions are blocked, flies become unusually susceptible to parasitism. Based on the presence of conserved amidase domains, tsetse PGRP-LB may scavenge the peptidoglycan (PGN) released by Wigglesworthia and prevent the activation of symbiont-damaging host immune responses. In addition, tsetse PGRP-LB may have an anti-protozoal activity that confers parasite resistance. The symbiotic adaptations and the limited exposure of tsetse to foreign microbes may have led to the considerable differences in pgrp-lb expression and regulation noted in tsetse from that of closely related Drosophila. A dynamic interplay between Wigglesworthia and host immunity apparently is influential in tsetse's ability to transmit trypanosomes.}, }
@article {pmid19586555, year = {2009}, author = {Noda, S and Hongoh, Y and Sato, T and Ohkuma, M}, title = {Complex coevolutionary history of symbiotic Bacteroidales bacteria of various protists in the gut of termites.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {158}, pmid = {19586555}, issn = {1471-2148}, mesh = {Animals ; Bacteroidetes/*genetics ; *Biological Evolution ; DNA, Bacterial/genetics ; Eukaryota/*microbiology ; Gastrointestinal Tract/microbiology ; In Situ Hybridization, Fluorescence ; Isoptera/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {BACKGROUND: The microbial community in the gut of termites is responsible for the efficient decomposition of recalcitrant lignocellulose. Prominent features of this community are its complexity and the associations of prokaryotes with the cells of cellulolytic flagellated protists. Bacteria in the order Bacteroidales are involved in associations with a wide variety of gut protist species as either intracellular endosymbionts or surface-attached ectosymbionts. In particular, ectosymbionts exhibit distinct morphological patterns of the associations. Therefore, these Bacteroidales symbionts provide an opportunity to investigate not only the coevolutionary relationships with the host protists and their morphological evolution but also how symbiotic associations between prokaryotes and eukaryotes occur and evolve within a complex symbiotic community.<br><br>RESULTS: Molecular phylogeny of 31 taxa of Bacteroidales symbionts from 17 protist genera in 10 families was examined based on 16S rRNA gene sequences. Their localization, morphology, and specificity were also examined by fluorescent in situ hybridizations. Although a monophyletic grouping of the ectosymbionts occurred in three related protist families, the symbionts of different protist genera were usually dispersed among several phylogenetic clusters unique to termite-gut bacteria. Similar morphologies of the associations occurred in multiple lineages of the symbionts. Nevertheless, the symbionts of congeneric protist species were closely related to one another, and in most cases, each host species harbored a unique Bacteroidales species. The endosymbionts were distantly related to the ectosymbionts examined so far.<br><br>CONCLUSION: The coevolutionary history of gut protists and their associated Bacteroidales symbionts is complex. We suggest multiple independent acquisitions of the Bacteroidales symbionts by different protist genera from a pool of diverse bacteria in the gut community. In this sense, the gut could serve as a reservoir of diverse bacteria for associations with the protist cells. The similar morphologies are considered a result of evolutionary convergence. Despite the complicated evolutionary history, the host-symbiont relationships are mutually specific, suggesting their cospeciations at the protist genus level with only occasional replacements.}, }
@article {pmid19583787, year = {2009}, author = {Kaltenpoth, M and Winter, SA and Kleinhammer, A}, title = {Localization and transmission route of Coriobacterium glomerans, the endosymbiont of pyrrhocorid bugs.}, journal = {FEMS microbiology ecology}, volume = {69}, number = {3}, pages = {373-383}, doi = {10.1111/j.1574-6941.2009.00722.x}, pmid = {19583787}, issn = {1574-6941}, mesh = {Actinobacteria/classification/genetics/*isolation &amp; purification ; Animals ; DNA, Bacterial/genetics ; Female ; Genes, rRNA ; Heteroptera/*microbiology ; Male ; Oviposition ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Endosymbiotic gut bacteria play an essential role in the nutrition of many insects. Most of the nutritional interactions investigated so far involve gammaproteobacterial symbionts, whereas other groups have received comparatively little attention. Here, we report on the localization and the transmission route of the specific actinobacterial symbiont Coriobacterium glomerans from the gut of the red firebug, Pyrrhocoris apterus (Hemiptera: Pyrrhocoridae). The symbionts were detected by diagnostic PCRs and FISH in the midgut section M3, in the rectum and in feces of the bugs as well as in the hemolymph of some females. Furthermore, adult female bugs apply the symbionts to the surface of the eggs during oviposition, from where they are later taken up by the hatchlings. Surface sterilization of egg clutches generated aposymbiotic insects and thereby confirmed the vertical transmission route via the egg surface. However, symbionts were readily acquired horizontally when the nymphs were reared in the presence of symbiont-containing eggshells, feces, or adult bugs. Using diagnostic PCRs and partial sequencing of the 16S rRNA gene, closely related bacterial symbionts were detected in the cotton stainer bug Dysdercus fasciatus (Hemiptera: Pyrrhocoridae), suggesting that the symbiosis with Actinobacteria may be widespread among pyrrhocorid bugs.}, }
@article {pmid19582169, year = {2009}, author = {Morris, PF and Schlosser, LR and Onasch, KD and Wittenschlaeger, T and Austin, R and Provart, N}, title = {Multiple horizontal gene transfer events and domain fusions have created novel regulatory and metabolic networks in the oomycete genome.}, journal = {PloS one}, volume = {4}, number = {7}, pages = {e6133}, pmid = {19582169}, issn = {1932-6203}, mesh = {*Gene Fusion ; *Gene Transfer, Horizontal ; *Genome, Fungal ; Oomycetes/*genetics/metabolism ; Species Specificity ; }, abstract = {Complex enzymes with multiple catalytic activities are hypothesized to have evolved from more primitive precursors. Global analysis of the Phytophthora sojae genome using conservative criteria for evaluation of complex proteins identified 273 novel multifunctional proteins that were also conserved in P. ramorum. Each of these proteins contains combinations of protein motifs that are not present in bacterial, plant, animal, or fungal genomes. A subset of these proteins were also identified in the two diatom genomes, but the majority of these proteins have formed after the split between diatoms and oomycetes. Documentation of multiple cases of domain fusions that are common to both oomycetes and diatom genomes lends additional support for the hypothesis that oomycetes and diatoms are monophyletic. Bifunctional proteins that catalyze two steps in a metabolic pathway can be used to infer the interaction of orthologous proteins that exist as separate entities in other genomes. We postulated that the novel multifunctional proteins of oomycetes could function as potential Rosetta Stones to identify interacting proteins of conserved metabolic and regulatory networks in other eukaryotic genomes. However ortholog analysis of each domain within our set of 273 multifunctional proteins against 39 sequenced bacterial and eukaryotic genomes, identified only 18 candidate Rosetta Stone proteins. Thus the majority of multifunctional proteins are not Rosetta Stones, but they may nonetheless be useful in identifying novel metabolic and regulatory networks in oomycetes. Phylogenetic analysis of all the enzymes in three pathways with one or more novel multifunctional proteins was conducted to determine the probable origins of individual enzymes. These analyses revealed multiple examples of horizontal transfer from both bacterial genomes and the photosynthetic endosymbiont in the ancestral genome of Stramenopiles. The complexity of the phylogenetic origins of these metabolic pathways and the paucity of Rosetta Stones relative to the total number of multifunctional proteins suggests that the proteome of oomycetes has few features in common with other Kingdoms.}, }
@article {pmid19568951, year = {2009}, author = {Komura, M and Itoh, S}, title = {Fluorescence measurement by a streak camera in a single-photon-counting mode.}, journal = {Photosynthesis research}, volume = {101}, number = {2-3}, pages = {119-133}, pmid = {19568951}, issn = {1573-5079}, mesh = {Arabidopsis/physiology ; Energy Transfer ; *Photons ; Photosystem II Protein Complex/metabolism ; Spectrometry, Fluorescence/*instrumentation/*methods ; Time Factors ; }, abstract = {We describe here a recently developed fluorescence measurement system that uses a streak camera to detect fluorescence decay in a single photon-counting mode. This system allows for easy measurements of various samples and provides 2D images of fluorescence in the wavelength and time domains. The great advantage of the system is that the data can be handled with ease; furthermore, the data are amenable to detailed analysis. We describe the picosecond kinetics of fluorescence in spinach Photosystem (PS) II particles at 4-77 K as a typical experimental example. Through the global analysis of the data, we have identified a new fluorescence band (F689) in addition to the already established F680, F685, and F695 emission bands. The blue shift of the steady-state fluorescence spectrum upon cooling below 77 K can be interpreted as an increase of the shorter-wavelength fluorescence, especially F689, due to the slowdown of the excitation energy transfer process. The F685 and F695 bands seem to be thermally equilibrated at 77 K but not at 4 K. The simple and efficient photon accumulation feature of the system allows us to measure fluorescence from leaves, solutions, single colonies, and even single cells. The 2D fluorescence images obtained by this system are presented for isolated spinach PS II particles, intact leaves of Arabidopsis thaliana, the PS I super-complex of a marine centric diatom, Chaetoceros gracilis, isolated membranes of a purple photosynthetic bacterium, Acidiphilium rubrum, which contains Zn-BChl a, and a coral that contains a green fluorescent protein and an algal endosymbiont, Zooxanthella.}, }
@article {pmid19568419, year = {2009}, author = {Yang, JC and Madupu, R and Durkin, AS and Ekborg, NA and Pedamallu, CS and Hostetler, JB and Radune, D and Toms, BS and Henrissat, B and Coutinho, PM and Schwarz, S and Field, L and Trindade-Silva, AE and Soares, CA and Elshahawi, S and Hanora, A and Schmidt, EW and Haygood, MG and Posfai, J and Benner, J and Madinger, C and Nove, J and Anton, B and Chaudhary, K and Foster, J and Holman, A and Kumar, S and Lessard, PA and Luyten, YA and Slatko, B and Wood, N and Wu, B and Teplitski, M and Mougous, JD and Ward, N and Eisen, JA and Badger, JH and Distel, DL}, title = {The complete genome of Teredinibacter turnerae T7901: an intracellular endosymbiont of marine wood-boring bivalves (shipworms).}, journal = {PloS one}, volume = {4}, number = {7}, pages = {e6085}, pmid = {19568419}, issn = {1932-6203}, mesh = {Animals ; Bivalvia/metabolism/*microbiology ; Computational Biology ; *Genome, Bacterial ; *Marine Biology ; Nitrogen/metabolism ; Phylogeny ; Polysaccharides/metabolism ; Proteobacteria/classification/enzymology/*genetics/physiology ; Quorum Sensing ; Spectrometry, Mass, Electrospray Ionization ; *Symbiosis ; Tandem Mass Spectrometry ; *Wood ; }, abstract = {Here we report the complete genome sequence of Teredinibacter turnerae T7901. T. turnerae is a marine gamma proteobacterium that occurs as an intracellular endosymbiont in the gills of wood-boring marine bivalves of the family Teredinidae (shipworms). This species is the sole cultivated member of an endosymbiotic consortium thought to provide the host with enzymes, including cellulases and nitrogenase, critical for digestion of wood and supplementation of the host's nitrogen-deficient diet. T. turnerae is closely related to the free-living marine polysaccharide degrading bacterium Saccharophagus degradans str. 2-40 and to as yet uncultivated endosymbionts with which it coexists in shipworm cells. Like S. degradans, the T. turnerae genome encodes a large number of enzymes predicted to be involved in complex polysaccharide degradation (>100). However, unlike S. degradans, which degrades a broad spectrum (>10 classes) of complex plant, fungal and algal polysaccharides, T. turnerae primarily encodes enzymes associated with deconstruction of terrestrial woody plant material. Also unlike S. degradans and many other eubacteria, T. turnerae dedicates a large proportion of its genome to genes predicted to function in secondary metabolism. Despite its intracellular niche, the T. turnerae genome lacks many features associated with obligate intracellular existence (e.g. reduced genome size, reduced %G+C, loss of genes of core metabolism) and displays evidence of adaptations common to free-living bacteria (e.g. defense against bacteriophage infection). These results suggest that T. turnerae is likely a facultative intracellular ensosymbiont whose niche presently includes, or recently included, free-living existence. As such, the T. turnerae genome provides insights into the range of genomic adaptations associated with intracellular endosymbiosis as well as enzymatic mechanisms relevant to the recycling of plant materials in marine environments and the production of cellulose-derived biofuels.}, }
@article {pmid19567561, year = {2009}, author = {Hahn, MW and Lang, E and Brandt, U and Wu, QL and Scheuerl, T}, title = {Emended description of the genus Polynucleobacter and the species Polynucleobacter necessarius and proposal of two subspecies, P. necessarius subsp. necessarius subsp. nov. and P. necessarius subsp. asymbioticus subsp. nov.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {59}, number = {Pt 8}, pages = {2002-2009}, pmid = {19567561}, issn = {1466-5026}, support = {P 19853/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Bacterial Typing Techniques ; Base Composition ; Burkholderiaceae/chemistry/*classification/genetics/physiology ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Euplotes/microbiology ; Fatty Acids/analysis ; Genome, Bacterial ; Locomotion ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {Heckmann and Schmidt described the genus Polynucleobacter for bacterial endosymbionts of freshwater ciliates affiliated with the genus Euplotes, and the species Polynucleobacter necessarius for obligate endosymbionts living in the cytoplasm of Euplotes aediculatus. Pure cultures of the type strain could not be established due to the obligate nature of the symbiotic relationship between the endosymbionts and their hosts. Therefore, Polynucleobacter necessarius is one of a few bacterial species with validly published names that lack a deposited pure culture. Meanwhile, it was demonstrated that the endosymbionts used for the description of the type of Polynucleobacter necessarius are closely related to obligately free-living strains. Similarity values of the 16S rRNA gene sequences obtained from the endosymbionts in the ciliate culture and free-living isolates in the range 99.1-99.4% indicate that these organisms belong to the same species. Here, we have emended the description of Polynucleobacter necessarius by characterization of free-living strains maintained as pure cultures. The species Polynucleobacter necessarius was characterized as having low G+C contents of the DNA (44-46 mol%), small genome sizes (1.5-2.5 Mbp) and a lack of motility. Because of distinct differences in lifestyle and the genome size of Polynucleobacter necessarius strains, we propose that two novel subspecies should be established, Polynucleobacter necessarius subsp. necessarius subsp. nov. [with a type, which is a description based on endosymbionts in the culture 'stock 15' of the ciliate E. aediculatus (ATCC 30859)] and Polynucleobacter necessarius subsp. asymbioticus subsp. nov. [with the type strain QLW-P1DMWA-1T (=DSM 18221T=CIP 109841T)], for the obligate endosymbionts of E. aediculatus and Euplotes harpa and obligately free-living strains, respectively.}, }
@article {pmid19556510, year = {2009}, author = {Moustafa, A and Beszteri, B and Maier, UG and Bowler, C and Valentin, K and Bhattacharya, D}, title = {Genomic footprints of a cryptic plastid endosymbiosis in diatoms.}, journal = {Science (New York, N.Y.)}, volume = {324}, number = {5935}, pages = {1724-1726}, doi = {10.1126/science.1172983}, pmid = {19556510}, issn = {1095-9203}, support = {R01ES013679/ES/NIEHS NIH HHS/United States ; T32 GM98629/GM/NIGMS NIH HHS/United States ; }, mesh = {Biological Evolution ; Cell Nucleus/genetics ; Chlorophyta/classification/*genetics/physiology ; Diatoms/classification/*genetics/physiology ; Gene Transfer, Horizontal ; Genes ; *Genome ; Phylogeny ; Plastids/*genetics ; Rhodophyta/classification/*genetics/physiology ; *Symbiosis ; }, abstract = {Diatoms and other chromalveolates are among the dominant phytoplankters in the world's oceans. Endosymbiosis was essential to the success of chromalveolates, and it appears that the ancestral plastid in this group had a red algal origin via an ancient secondary endosymbiosis. However, recent analyses have turned up a handful of nuclear genes in chromalveolates that are of green algal derivation. Using a genome-wide approach to estimate the "green" contribution to diatoms, we identified >1700 green gene transfers, constituting 16% of the diatom nuclear coding potential. These genes were probably introduced into diatoms and other chromalveolates from a cryptic endosymbiont related to prasinophyte-like green algae. Chromalveolates appear to have recruited genes from the two major existing algal groups to forge a highly successful, species-rich protist lineage.}, }
@article {pmid19549139, year = {2009}, author = {Bieri, AP and Härri, SA and Vorburger, C and Müller, CB}, title = {Aphid genotypes vary in their response to the presence of fungal endosymbionts in host plants.}, journal = {Journal of evolutionary biology}, volume = {22}, number = {8}, pages = {1775-1780}, doi = {10.1111/j.1420-9101.2009.01788.x}, pmid = {19549139}, issn = {1420-9101}, mesh = {Animals ; Aphids/*genetics/microbiology ; Fungi/*physiology ; Genotype ; Host-Parasite Interactions ; Lolium/microbiology/*parasitology ; *Symbiosis ; }, abstract = {Genetic variation for fitness-relevant traits may be maintained in natural populations by fitness differences that depend on environmental conditions. For herbivores, plant quality and variation in chemical plant defences can maintain genetic variation in performance. Apart from plant secondary compounds, symbiosis between plants and endosymbiotic fungi (endophytes) can produce herbivore-toxic compounds. We show that there is significant variation among aphid genotypes in response to endophytes by comparing life-history traits of 37 clones of the bird cherry-oat aphid Rhopalosiphum padi feeding on endophyte-free and endophyte-infected tall fescue Lolium arundinaceum. Clonal variation for life-history traits was large, and most clones performed better on endophyte-free plants. However, the clones differed in the relative performance across the two environments, resulting in significant genotype x environment interactions for all reproductive traits. These findings suggest that natural variation in prevalence of endophyte infection can contribute to the maintenance of genetic diversity in aphid populations.}, }
@article {pmid19545353, year = {2009}, author = {Goodacre, SL and Martin, OY and Bonte, D and Hutchings, L and Woolley, C and Ibrahim, K and George Thomas, C and Hewitt, GM}, title = {Microbial modification of host long-distance dispersal capacity.}, journal = {BMC biology}, volume = {7}, number = {}, pages = {32}, pmid = {19545353}, issn = {1741-7007}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Behavior, Animal ; Female ; Male ; Maternal Exposure ; Population Dynamics ; Rickettsia/drug effects/growth &amp; development ; Spiders/drug effects/*microbiology ; Spiroplasma/drug effects/growth &amp; development ; Symbiosis ; Wolbachia/drug effects/growth &amp; development ; }, abstract = {BACKGROUND: Dispersal plays a key role in shaping biological and ecological processes such as the distribution of spatially-structured populations or the pace and scale of invasion. Here we have studied the relationship between long-distance dispersal behaviour of a pest-controlling money spider, Erigone atra, and the distribution of maternally acquired endosymbionts within the wider meta-population. This spider persists in heterogeneous environments because of its ability to recolonise areas through active long-distance airborne dispersal using silk as a sail, in a process termed 'ballooning'.<br><br>RESULTS: We show that there is spatial heterogeneity in the prevalence of two maternally acquired endosymbiont infections within the wider E. atra meta-population and we demonstrate through several independent approaches a link between the presence of one of these endosymbionts, Rickettsia, and the tendency for long-distance movement.<br><br>CONCLUSION: This novel finding that particular endosymbionts can influence host dispersal is of broad importance given the extremely widespread occurrence of similar bacteria within arthropod communities. A bacterial phenotype that limits dispersal has the potential not only to reduce gene flow and thus contribute to degrees of reproductive isolation within species, but also to influence species distribution and thus overall community composition.}, }
@article {pmid19534824, year = {2009}, author = {Zhang, YJ and Tian, HF and Wen, JF}, title = {The evolution of YidC/Oxa/Alb3 family in the three domains of life: a phylogenomic analysis.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {137}, pmid = {19534824}, issn = {1471-2148}, mesh = {Algal Proteins/genetics ; Animals ; Archaeal Proteins/genetics ; Bacterial Proteins/genetics ; *Evolution, Molecular ; Humans ; Likelihood Functions ; Membrane Transport Proteins/*genetics ; Mitochondrial Proteins/genetics ; *Phylogeny ; Plant Proteins/genetics ; Protozoan Proteins/genetics ; Sequence Alignment ; Thylakoids/genetics ; }, abstract = {BACKGROUND: YidC/Oxa/Alb3 family includes a group of conserved translocases that are essential for protein insertion into inner membranes of bacteria and mitochondria, and thylakoid membranes of chloroplasts. Because mitochondria and chloroplasts are of bacterial origin, Oxa and Alb3, like many other mitochondrial/chloroplastic proteins, are hypothetically derived from the pre-existing protein (YidC) of bacterial endosymbionts. Here, we test this hypothesis and investigate the evolutionary history of the whole YidC/Oxa/Alb3 family in the three domains of life.<br><br>RESULTS: Our comprehensive analyses of the phylogenetic distribution and phylogeny of the YidC/Oxa/Alb3 family lead to the following findings: 1) In archaea, YidC homologs are only sporadically distributed in Euryarchaeota; 2) Most bacteria contain only one YidC gene copy; some species in a few taxa (Bacillus, Lactobacillales, Actinobacteria and Clostridia) have two gene copies; 3) Eukaryotic Oxa and Alb3 have two separate prokaryotic origins, but they might not arise directly from the YidC of proteobacteria and cyanobacteria through the endosymbiosis origins of mitochondrium and chloroplast, respectively; 4) An ancient duplication occurred on both Oxa and Alb3 immediately after their origins, and thus most eukaryotes generally bear two Oxa and two Alb3. However, secondary loss, duplication or acquisition of new domain also occurred on the two genes in some lineages, especially in protists, resulting in a rich diversity or adaptive differentiation of the two translocases in these lineages.<br><br>CONCLUSION: YidC is distributed in bacteria and some Euryarchaeota. Although mitochondrial Oxa and chloroplastic Alb3 are derived from the prokaryotic YidC, their origin might be not related to the endosymbiosis events of the two organelles. In some eukaryotic lineages, especially in protists, Oxa and Alb3 have diverse evolutionary histories. Finally, a model for the evolutionary history of the entire YidC/Oxa/Alb3 family in the three domains of life is proposed.}, }
@article {pmid19523069, year = {2009}, author = {Machtelinckx, T and Van Leeuwen, T and Vanholme, B and Gehesquière, B and Dermauw, W and Vandekerkhove, B and Gheysen, G and De Clercq, P}, title = {Wolbachia induces strong cytoplasmic incompatibility in the predatory bug Macrolophus pygmaeus.}, journal = {Insect molecular biology}, volume = {18}, number = {3}, pages = {373-381}, doi = {10.1111/j.1365-2583.2009.00877.x}, pmid = {19523069}, issn = {1365-2583}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Female ; Fluorescent Antibody Technique ; Heteroptera/*microbiology/physiology ; Male ; Phylogeny ; Polymerase Chain Reaction ; Reproduction ; *Symbiosis ; Tetracycline ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {Macrolophus pygmaeus is a heteropteran predator that is widely used in European glasshouses for the biological control of whiteflies, aphids, thrips and spider mites. We have demonstrated that the insect is infected with the endosymbiotic bacterium Wolbachia pipientis. Several gene fragments of the endosymbiont were sequenced and subsequently used for phylogenetic analysis, revealing that it belongs to the Wolbachia supergroup B. The endosymbiont was visualized within the ovarioles using immunolocalization. Tetracycline treatments were used to cure M. pygmaeus from its infection. Although a completely cured line could not be obtained by this approach, the application of a constant antibiotic pressure over 13 generations resulted in a line with a significantly reduced Wolbachia concentration. Crosses performed with this tetracycline-treated line revealed that the endosymbiont causes severe cytoplasmic incompatibility. This is the first report of a reproductive effect induced by Wolbachia in an economically important heteropteran predator that may have vital implications for its commercial production and use in biological control.}, }
@article {pmid19523050, year = {2010}, author = {Mumcuoglu, KY and Huberman, L and Cohen, R and Temper, V and Adler, A and Galun, R and Block, C}, title = {Elimination of symbiotic Aeromonas spp. from the intestinal tract of the medicinal leech, Hirudo medicinalis, using ciprofloxacin feeding.}, journal = {Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases}, volume = {16}, number = {6}, pages = {563-567}, doi = {10.1111/j.1469-0691.2009.02868.x}, pmid = {19523050}, issn = {1469-0691}, mesh = {Aeromonas/classification/*drug effects/genetics/*isolation &amp; purification ; Animals ; Anti-Bacterial Agents/*administration &amp; dosage ; Bacterial Proteins/genetics ; Ciprofloxacin/*administration &amp; dosage ; Cluster Analysis ; DNA Gyrase/genetics ; Fungi/classification/isolation &amp; purification ; Gastrointestinal Tract/microbiology ; Genotype ; Hirudo medicinalis/*microbiology ; Humans ; Leeching/methods ; Sequence Analysis, DNA ; Sequence Homology ; }, abstract = {The use of the medicinal leech (Hirudo medicinalis) in promoting venous drainage in tissues whose vitality is threatened by venous congestion and obstruction, especially in plastic and reconstructive surgery, has been complicated by infections caused by Aeromonas spp. These are leech endosymbionts for which patients undergoing hirudotherapy frequently receive systemic chemoprophylaxis. In order to evaluate the possibility of rendering leeches safe for use on patients, H. medicinalis were fed artificially with a 2 g/L arginine solution (used as a phagostimulant) supplemented with ciprofloxacin (100 mg/L). Aeromonads were detected in 57 out of 80 control leeches (71.3%), but in none of the 56 leeches treated with ciprofloxacin (p <0.001). Treated leeches survived for up to 4 months. Tested weekly, 61% of these leeches took human blood for at least 4 weeks after treatment and all remained negative for aeromonads. All water samples in which leeches were kept before treatment were contaminated with Aeromonas spp.; none were detected in any of the NaCl/arginine solutions with which treated animals were fed. Molecular characterization of two phenotypically distinct isolates using gyrB sequencing showed that one clustered tightly with A. veronii and the other was closely related to A. media. Other environmental bacteria and fungi were isolated from 26.5% of treated leeches that had taken a blood meal 1-4 weeks after treatment. Ciprofloxacin reduced the number of leech-associated aeromonads to undetectable levels for extended periods. Most treated leeches were ready to take a blood meal after treatment, suggesting the possibility of using ciprofloxacin-treated leeches instead of chemoprophylaxis in patients undergoing hirudotherapy.}, }
@article {pmid19519634, year = {2009}, author = {Dannowski, J and Flor, M and Telschow, A and Hammerstein, P}, title = {The effect of sibmating on the infection dynamics of male-killing bacteria.}, journal = {Evolution; international journal of organic evolution}, volume = {63}, number = {10}, pages = {2525-2534}, doi = {10.1111/j.1558-5646.2009.00749.x}, pmid = {19519634}, issn = {1558-5646}, mesh = {Animals ; Female ; Insecta/*microbiology ; Male ; Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {Male-killing (MK) bacteria are vertically transmitted endosymbionts that selectively kill the male offspring of their hosts. Simple mathematical models describe the infection dynamics using two parameters, the bacterial transmission rate and a fitness compensation for siblings of killed males. These models cannot explain two phenomena that have been observed in nature: the persistence of extreme MK causing all-female broods, and the coexistence of two different strains of MK bacteria in the same host population. In the present study, we extend the simple MK models and investigate theoretically the effects of sibmating on the infection dynamics. We demonstrate analytically that, in general, sibmating reduces MK prevalence, and can even cause its extinction. As a special case of this finding, we show that sibmating allows a stable coexistence between no infection and extreme MK. Furthermore, we performed computer simulations and showed that, depending on male mating capacity, a stable coexistence of two strains is possible if sibmating occurs but is below a threshold. The results suggest that sibmating might be an important factor for understanding the infection dynamics of MK bacteria.}, }
@article {pmid19513200, year = {2008}, author = {Nagamune, K and Xiong, L and Chini, E and Sibley, LD}, title = {Plants, endosymbionts and parasites: Abscisic acid and calcium signaling.}, journal = {Communicative &amp; integrative biology}, volume = {1}, number = {1}, pages = {62-65}, pmid = {19513200}, issn = {1942-0889}, support = {R01 AI034036/AI/NIAID NIH HHS/United States ; R21 AI067051/AI/NIAID NIH HHS/United States ; }, abstract = {It was recently discovered that the protozoan parasite, Toxoplasma gondii produces and uses the plant hormone, abscisic acid (ABA), for communication. Following intracellular replication, ABA production influences the timing of parasite egress from the host cell. This density-dependent signal may serve to coordinate exit from the host cell in a synchronous manner by triggering calcium-dependent activation of motility. In the absence of ABA production, parasites undergo differentiation to the semidormant, tissue cyst. The pathway for ABA production in T. gondii may be derived from a relict endosymbiont, acquired by ingestion of a red algal cell. Although the parasite has lost the capacity for photosynthesis, the plant-like nature of this signaling pathway may be exploited to develop new drugs. In support of this idea, an inhibitor of ABA biosynthesis protected mice against lethal infection with T. gondii. Here, we compare the role of ABA in parasites to its activities in plants, where it is know to control development and stress responses.}, }
@article {pmid19513091, year = {2009}, author = {Lorenzo-Carballa, MO and Cordero-Rivera, A}, title = {Thelytokous parthenogenesis in the damselfly Ischnura hastata (Odonata, Coenagrionidae): genetic mechanisms and lack of bacterial infection.}, journal = {Heredity}, volume = {103}, number = {5}, pages = {377-384}, doi = {10.1038/hdy.2009.65}, pmid = {19513091}, issn = {1365-2540}, mesh = {Animals ; Bacterial Infections/*genetics ; DNA, Bacterial/analysis ; Female ; Host-Pathogen Interactions/genetics ; Insecta/*genetics/microbiology/*physiology ; Male ; Microsatellite Repeats/genetics ; Parthenogenesis/*genetics/physiology ; Polymerase Chain Reaction ; Reproduction/genetics ; Symbiosis/genetics ; }, abstract = {Thelytokous parthenogenesis, the production of female-only offspring from unfertilized eggs, has been described in all the insect orders, but is a rare phenomenon in the Odonata (dragonflies and damselflies). The only-known case of parthenogenesis in this group is the North American damselfly species Ischnura hastata, which has parthenogenetic populations in the Azores Islands. Here, we present for the first time the results of laboratory rearing, which showed parthenogenetic reproduction in the Azorean I. hastata populations. In an attempt to understand how parthenogenesis could have evolved in this species, we first determined the genetic mode of parthenogenesis by analysing the genotype of parthenogenetic females and their offspring at three polymorphic microsatellite loci. In addition, we used polymerase chain reaction amplification to test whether parthenogenesis in I. hastata could be bacterially induced. Our data indicate that thelytoky is achieved through an (at least functionally) apomictic mechanism and that parthenogenesis is not caused by endosymbionts. Finally, we discuss possible routes to parthenogenetic reproduction, as well as the evolutionary implications of this type of parthenogenesis.}, }
@article {pmid19508425, year = {2009}, author = {Yano, K and Shibata, S and Chen, WL and Sato, S and Kaneko, T and Jurkiewicz, A and Sandal, N and Banba, M and Imaizumi-Anraku, H and Kojima, T and Ohtomo, R and Szczyglowski, K and Stougaard, J and Tabata, S and Hayashi, M and Kouchi, H and Umehara, Y}, title = {CERBERUS, a novel U-box protein containing WD-40 repeats, is required for formation of the infection thread and nodule development in the legume-Rhizobium symbiosis.}, journal = {The Plant journal : for cell and molecular biology}, volume = {60}, number = {1}, pages = {168-180}, doi = {10.1111/j.1365-313X.2009.03943.x}, pmid = {19508425}, issn = {1365-313X}, mesh = {Amino Acid Sequence ; Chromosome Mapping ; Cloning, Molecular ; DNA, Plant/genetics ; Gene Expression Profiling ; Gene Expression Regulation, Plant ; Genetic Complementation Test ; Lotus/*genetics/microbiology ; Molecular Sequence Data ; Phenotype ; Plant Proteins/genetics/*metabolism ; Rhizobium/*physiology ; Root Nodules, Plant/*growth &amp; development/microbiology ; Sequence Alignment ; *Symbiosis ; }, abstract = {Endosymbiotic infection of legume plants by Rhizobium bacteria is initiated through infection threads (ITs) which are initiated within and penetrate from root hairs and deliver the endosymbionts into nodule cells. Despite recent progress in understanding the mutual recognition and early symbiotic signaling cascades in host legumes, the molecular mechanisms underlying bacterial infection processes and successive nodule organogenesis are still poorly understood. We isolated a novel symbiotic mutant of Lotus japonicus, cerberus, which shows defects in IT formation and nodule organogenesis. Map-based cloning of the causal gene allowed us to identify the CERBERUS gene, which encodes a novel protein containing a U-box domain and WD-40 repeats. CERBERUS expression was detected in the roots and nodules, and was enhanced after inoculation of Mesorhizobium loti. Strong expression was detected in developing nodule primordia and the infected zone of mature nodules. In cerberus mutants, Rhizobium colonized curled root hair tips, but hardly penetrated into root hair cells. The occasional ITs that were formed inside the root hair cells were mostly arrested within the epidermal cell layer. Nodule organogenesis was aborted prematurely, resulting in the formation of a large number of small bumps which contained no endosymbiotic bacteria. These phenotypic and genetic analyses, together with comparisons with other legume mutants with defects in IT formation, indicate that CERBERUS plays a critical role in the very early steps of IT formation as well as in growth and differentiation of nodules.}, }
@article {pmid19506574, year = {2009}, author = {Gross, J and Bhattacharya, D}, title = {Mitochondrial and plastid evolution in eukaryotes: an outsiders' perspective.}, journal = {Nature reviews. Genetics}, volume = {10}, number = {7}, pages = {495-505}, pmid = {19506574}, issn = {1471-0064}, mesh = {Animals ; Eukaryotic Cells/*physiology ; *Evolution, Molecular ; Humans ; Plants ; Plastids/*physiology ; Protein Transport/physiology ; }, abstract = {The eukaryotic organelles mitochondrion and plastid originated from eubacterial endosymbionts. Here we propose that, in both cases, prokaryote-to-organelle conversion was driven by the internalization of host-encoded factors progressing from the outer membrane of the endosymbionts towards the intermembrane space, inner membrane and finally the organelle interior. This was made possible by an outside-to-inside establishment in the endosymbionts of host-controlled protein-sorting components, which enabled the gradual integration of organelle functions into the nuclear genome. Such a convergent trajectory for mitochondrion and plastid establishment suggests a novel paradigm for organelle evolution that affects theories of eukaryogenesis.}, }
@article {pmid19504759, year = {2009}, author = {Haegeman, A and Vanholme, B and Jacob, J and Vandekerckhove, TT and Claeys, M and Borgonie, G and Gheysen, G}, title = {An endosymbiotic bacterium in a plant-parasitic nematode: member of a new Wolbachia supergroup.}, journal = {International journal for parasitology}, volume = {39}, number = {9}, pages = {1045-1054}, doi = {10.1016/j.ijpara.2009.01.006}, pmid = {19504759}, issn = {1879-0135}, mesh = {Animals ; Arthropods/*genetics/parasitology ; Gene Expression Profiling ; Genes, Helminth/*genetics ; Host-Parasite Interactions ; Molecular Sequence Data ; Nematoda/*genetics ; Phylogeny ; Sequence Analysis, DNA ; Symbiosis/*genetics ; Wolbachia/classification/*genetics ; }, abstract = {Wolbachia is an endosymbiotic bacterium widely present in arthropods and animal-parasitic nematodes. Despite previous efforts, it has never been identified in plant-parasitic nematodes. Random sequencing of genes expressed by the burrowing nematode Radopholus similis resulted in several sequences with similarity to Wolbachia genes. The presence of a Wolbachia-like endosymbiont in this plant-parasitic nematode was investigated using both morphological and molecular approaches. Transmission electronmicroscopy, fluorescent immunolocalisation and staining with DAPI confirmed the presence of the endosymbiont within the reproductive tract of female adults. 16S rDNA, ftsZ and groEL gene sequences showed that the endosymbiont of R. similis is distantly related to the known Wolbachia supergroups. Finally, based on our initial success in finding sequences of this endosymbiont by screening an expressed sequence tag (EST) dataset, all nematode ESTs were mined for Wolbachia-like sequences. Although the retained sequences belonged to six different nematode species, R. similis was the only plant-parasitic nematode with traces of Wolbachia. Based on our phylogenetic study and the current literature we designate the endosymbiont of R. similis to a new supergroup (supergroup I) rather than considering it as a new species. Although its role remains unknown, the endosymbiont was found in all individuals tested, pointing towards an essential function of the bacteria.}, }
@article {pmid19500365, year = {2009}, author = {Sunagawa, S and Wilson, EC and Thaler, M and Smith, ML and Caruso, C and Pringle, JR and Weis, VM and Medina, M and Schwarz, JA}, title = {Generation and analysis of transcriptomic resources for a model system on the rise: the sea anemone Aiptasia pallida and its dinoflagellate endosymbiont.}, journal = {BMC genomics}, volume = {10}, number = {}, pages = {258}, pmid = {19500365}, issn = {1471-2164}, mesh = {Animals ; Cluster Analysis ; Databases, Genetic ; Dinoflagellida/*genetics ; *Expressed Sequence Tags ; *Gene Expression Profiling ; Gene Library ; Sea Anemones/*genetics ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between cnidarian hosts and unicellular dinoflagellate algae. The molecular mechanisms underlying the establishment, maintenance, and breakdown of the symbiotic partnership are, however, not well understood. Efforts to dissect these questions have been slow, as corals are notoriously difficult to work with. In order to expedite this field of research, we generated and analyzed a collection of expressed sequence tags (ESTs) from the sea anemone Aiptasia pallida and its dinoflagellate symbiont (Symbiodinium sp.), a system that is gaining popularity as a model to study cellular, molecular, and genomic questions related to cnidarian-dinoflagellate symbioses.<br><br>RESULTS: A set of 4,925 unique sequences (UniSeqs) comprising 1,427 clusters of 2 or more ESTs (contigs) and 3,498 unclustered ESTs (singletons) was generated by analyzing 10,285 high-quality ESTs from a mixed host/symbiont cDNA library. Using a BLAST-based approach to predict which unique sequences derived from the host versus symbiont genomes, we found that the contribution of the symbiont genome to the transcriptome was surprisingly small (1.6-6.4%). This may reflect low levels of gene expression in the symbionts, low coverage of alveolate genes in the sequence databases, a small number of symbiont cells relative to the total cellular content of the anemones, or failure to adequately lyse symbiont cells. Furthermore, we were able to identify groups of genes that are known or likely to play a role in cnidarian-dinoflagellate symbioses, including oxidative stress pathways that emerged as a prominent biological feature of this transcriptome. All ESTs and UniSeqs along with annotation results and other tools have been made accessible through the implementation of a publicly accessible database named AiptasiaBase.<br><br>CONCLUSION: We have established the first large-scale transcriptomic resource for Aiptasia pallida and its dinoflagellate symbiont. These data provide researchers with tools to study questions related to cnidarian-dinoflagellate symbioses on a molecular, cellular, and genomic level. This groundwork represents a crucial step towards the establishment of a tractable model system that can be utilized to better understand cnidarian-dinoflagellate symbioses. With the advent of next-generation sequencing methods, the transcriptomic inventory of A. pallida and its symbiont, and thus the extent of AiptasiaBase, should expand dramatically in the near future.}, }
@article {pmid19496436, year = {2009}, author = {Baldridge, GD and Scoles, GA and Burkhardt, NY and Schloeder, B and Kurtti, TJ and Munderloh, UG}, title = {Transovarial transmission of Francisella-like endosymbionts and Anaplasma phagocytophilum variants in Dermacentor albipictus (Acari: Ixodidae).}, journal = {Journal of medical entomology}, volume = {46}, number = {3}, pages = {625-632}, pmid = {19496436}, issn = {0022-2585}, support = {R01 AI042792/AI/NIAID NIH HHS/United States ; R01 AI042792-10/AI/NIAID NIH HHS/United States ; R29 AI042792/AI/NIAID NIH HHS/United States ; AI042792/AI/NIAID NIH HHS/United States ; }, mesh = {Anaplasma/genetics/isolation &amp; purification ; Anaplasmosis/*microbiology/transmission ; Animals ; Arthropod Vectors/growth &amp; development/*microbiology/physiology ; DNA, Bacterial/chemistry/isolation &amp; purification ; Deer/*parasitology ; Dermacentor/growth &amp; development/*microbiology/physiology ; Ehrlichia/genetics/isolation &amp; purification ; Female ; Francisella/genetics/isolation &amp; purification ; Larva/microbiology ; Male ; Nymph/microbiology ; Polymorphism, Genetic ; Rickettsia/genetics/isolation &amp; purification ; Sequence Alignment ; Sequence Analysis, DNA ; }, abstract = {Dermacentor albipictus (Packard) is a North American tick that feeds on cervids and livestock. It is a suspected vector of anaplasmosis in cattle, but its microbial flora and vector potential remain underevaluated. We screened D. albipictus ticks collected from Minnesota white-tailed deer (Odocoileus virginianus) for bacteria of the genera Anaplasma, Ehrlichia, Francisella, and Rickettsia using polymerase chain reaction (PCR) gene amplification and sequence analyses. We detected Anaplasma phagocytophilum and Francisella-like endosymbionts (FLEs) in nymphal and adult ticks of both sexes at 45 and 94% prevalences, respectively. The A. phagocytophilum and FLEs were transovarially transmitted to F1 larvae by individual ticks at efficiencies of 10-40 and 95-100%, respectively. The FLEs were transovarially transmitted to F2 larvae obtained as progeny of adults from F1 larval ticks reared to maturity on a calf, but A. phagocytophilum were not. Based on PCR and tissue culture inoculation assays, A. phagocytophilum and FLEs were not transmitted to the calf. The amplified FLE 16S rRNA gene sequences were identical to that of an FLE detected in a D. albipictus from Texas, whereas those of the A. phagocytophilum were nearly identical to those of probable human-nonpathogenic A. phagocytophilum WI-1 and WI-2 variants detected in white-tailed deer from central Wisconsin. However, the D. albipictus A. phagocytophilum sequences differed from that of the nonpathogenic A. phagocytophilum variant-1 associated with Ixodes scapularis ticks and white-tailed deer as well as that of the human-pathogenic A. phagocytophilum ha variant associated with I. scapularis and the white-footed mouse, Peromyscus leucopus. The transovarial transmission of A. phagocytophilum variants in Dermacentor ticks suggests that maintenance of A. phagocytophilum in nature may not be solely dependent on horizontal transmission.}, }
@article {pmid19496412, year = {2009}, author = {Gavotte, L and Mercer, DR and Vandyke, R and Mains, JW and Dobson, SL}, title = {Wolbachia infection and resource competition effects on immature Aedes albopictus (Diptera: Culicidae).}, journal = {Journal of medical entomology}, volume = {46}, number = {3}, pages = {451-459}, pmid = {19496412}, issn = {0022-2585}, support = {R01 AI051533/AI/NIAID NIH HHS/United States ; AI-51533/AI/NIAID NIH HHS/United States ; R01 AI067434-01A1/AI/NIAID NIH HHS/United States ; R01 AI051533-01A1/AI/NIAID NIH HHS/United States ; AI-67434/AI/NIAID NIH HHS/United States ; R01 AI067434/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/growth &amp; development/*microbiology/physiology ; Animals ; *Competitive Behavior ; Feeding Behavior ; Female ; Larva/growth &amp; development/microbiology/physiology ; Male ; Sex Factors ; Wolbachia/*physiology ; }, abstract = {Wolbachia pipientis Hertig and Wolbach (Rickettsiales: Rickettsiaceae) are intracellular alpha-proteobacteria that occur naturally in Aedes albopictus (Skuse) (Diptera: Culicidae) and numerous other invertebrates. These endosymbionts can invade host populations by manipulating host reproduction. Wolbachia infections have been shown to impart both costs and benefits to hosts in terms of development, survival, and fecundity. Here, we monitor intraspecific competition among independent cohorts of infected or uninfected larvae. Levels of competition are manipulated by varying initial larval densities and food levels. Although larval density is observed to have major impacts on immature survivorship, sex ratio of eclosing adults, and developmental rates, the Wolbachia infection status had minimal impact on male immatures and no effect on immature females under these experimental conditions. Female and male immatures were observed to respond differently to competitive pressure, with the functional relationships of females and males consistent with scramble and contest competition, respectively. The results are discussed in relation to the evolution of naturally occurring Wolbachia infections in Ae. albopictus (i.e., natural population replacement events) and public health strategies that propose the manipulation of Wolbachia infections in Ae. albopictus populations.}, }
@article {pmid19492355, year = {2009}, author = {Davidov, Y and Jurkevitch, E}, title = {Predation between prokaryotes and the origin of eukaryotes.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {31}, number = {7}, pages = {748-757}, doi = {10.1002/bies.200900018}, pmid = {19492355}, issn = {1521-1878}, mesh = {*Biological Evolution ; Endocytosis ; Eukaryotic Cells/cytology/*metabolism ; Mitochondria/metabolism ; Phylogeny ; Prokaryotic Cells/cytology/*metabolism ; *Symbiosis ; }, abstract = {Accumulating data suggest that the eukaryotic cell originated from a merger of two prokaryotes, an archaeal host and a bacterial endosymbiont. However, since prokaryotes are unable to perform phagocytosis, the means by which the endosymbiont entered its host is an enigma. We suggest that a predatory or parasitic interaction between prokaryotes provides a reasonable explanation for this conundrum. According to the model presented here, the host in this interaction was an anaerobic archaeon with a periplasm-like space. The predator was a small (facultative) aerobic alpha-proteobacterium, which penetrated and replicated within the host periplasm, and later became the mitochondria. Plausible conditions under which this interaction took place and circumstances that may have led to the contemporary complex eukaryotic cell are discussed.}, }
@article {pmid19487243, year = {2009}, author = {De Riso, V and Raniello, R and Maumus, F and Rogato, A and Bowler, C and Falciatore, A}, title = {Gene silencing in the marine diatom Phaeodactylum tricornutum.}, journal = {Nucleic acids research}, volume = {37}, number = {14}, pages = {e96}, pmid = {19487243}, issn = {1362-4962}, mesh = {Algal Proteins/genetics ; Clone Cells ; Cryptochromes ; Cytosine/metabolism ; DNA Methylation ; Diatoms/*genetics/metabolism ; Flavoproteins/genetics ; *Gene Knockdown Techniques ; *Gene Silencing ; Genes, Reporter ; Genome ; Phenotype ; Phytochrome/genetics ; RNA Interference ; Transgenes ; }, abstract = {Diatoms are a major but poorly understood phytoplankton group. The recent completion of two whole genome sequences has revealed that they contain unique combinations of genes, likely recruited during their history as secondary endosymbionts, as well as by horizontal gene transfer from bacteria. A major limitation for the study of diatom biology and gene function is the lack of tools to generate targeted gene knockout or knockdown mutants. In this work, we have assessed the possibility of triggering gene silencing in Phaeodactylum tricornutum using constructs containing either anti-sense or inverted repeat sequences of selected target genes. We report the successful silencing of a GUS reporter gene expressed in transgenic lines, as well as the knockdown of endogenous phytochrome (DPH1) and cryptochrome (CPF1) genes. To highlight the utility of the approach we also report the first phenotypic characterization of a diatom mutant (cpf1). Our data open the way for reverse genetics in diatoms and represent a major advance for understanding their biology and ecology. Initial molecular analyses reveal that targeted downregulation likely occurs through transcriptional and post-transcriptional gene silencing mechanisms. Interestingly, molecular players involved in RNA silencing in other eukaryotes are only poorly conserved in diatoms.}, }
@article {pmid19486895, year = {2009}, author = {Pichon, S and Bouchon, D and Cordaux, R and Chen, L and Garrett, RA and Grève, P}, title = {Conservation of the Type IV secretion system throughout Wolbachia evolution.}, journal = {Biochemical and biophysical research communications}, volume = {385}, number = {4}, pages = {557-562}, doi = {10.1016/j.bbrc.2009.05.118}, pmid = {19486895}, issn = {1090-2104}, mesh = {Biological Transport/genetics ; DNA/*metabolism ; *Evolution, Molecular ; Gene Order ; Genome, Bacterial ; *Operon ; Protein Transport/genetics ; Proteins/*metabolism ; Wolbachia/*genetics/*metabolism ; }, abstract = {The Type IV Secretion System (T4SS) is an efficient pathway with which bacteria can mediate the transfer of DNA and/or proteins to eukaryotic cells. In Wolbachia pipientis, a maternally inherited obligate endosymbiont of arthropods and nematodes, two operons of vir genes, virB3-B6 and virB8-D4, encoding a T4SS were previously identified and characterized at two separate genomic loci. Using the largest data set of Wolbachia strains studied so far, we show that vir gene sequence and organization are strictly conserved among 37 Wolbachia strains inducing various phenotypes such as cytoplasmic incompatibility, feminization, or oogenesis in their arthropod hosts. In sharp contrast, extensive variation of genomic sequences flanking the virB8-D4 operon suggested its distinct location among Wolbachia genomes. Long term conservation of the T4SS may imply maintenance of a functional effector translocation system in Wolbachia, thereby suggesting the importance for the T4SS in Wolbachia biology and survival inside host cells.}, }
@article {pmid19485799, year = {2009}, author = {Bockarie, MJ and Taylor, MJ and Gyapong, JO}, title = {Current practices in the management of lymphatic filariasis.}, journal = {Expert review of anti-infective therapy}, volume = {7}, number = {5}, pages = {595-605}, doi = {10.1586/eri.09.36}, pmid = {19485799}, issn = {1744-8336}, mesh = {Animals ; Brugia/drug effects/microbiology ; Culex/parasitology ; Delivery of Health Care ; Elephantiasis, Filarial/*drug therapy/parasitology/*prevention &amp; control/transmission ; Filaricides/*therapeutic use ; Humans ; Insect Vectors/parasitology ; Microfilariae/drug effects ; Wolbachia/drug effects ; Wuchereria bancrofti/drug effects/microbiology ; }, abstract = {Lymphatic filariasis is a major cause of acute and chronic morbidity in 81 countries. The availability of safe treatment regimens along with rapid diagnostic tools resulted in a global program to eliminate the disease. The two main objectives of the global elimination program are to interrupt transmission of the parasites and to provide care for those with the disease. The strategy for transmission interruption is preventive chemotherapy through mass drug administration. This article reviews the current treatment regimens for lymphatic filariasis and discusses the challenges posed by co-endemicity with other diseases. The role of integrated vector management as a supplementary strategy for mass drug administration and new strategies for treatment and morbidity control through antibiotic targeting of the Wolbachia endosymbionts are also discussed.}, }
@article {pmid23100759, year = {2009}, author = {Rajagopal, R}, title = {Beneficial interactions between insects and gut bacteria.}, journal = {Indian journal of microbiology}, volume = {49}, number = {2}, pages = {114-119}, pmid = {23100759}, issn = {0046-8991}, abstract = {Insects are amongst the most successful of animals, both in terms of diversity and in colonizing all ecological niches. Recent studies have highlighted the benefi ciary roles that bacteria play in the success and establishment of insects. By adopting techniques like 16S rRNA sequencing we are now in a position to understand the diversity of bacteria present in insect guts. It has been shown that some of these bacteria, like Wolbachia and Cardinium are involved in manipulating insect populations and distorting their sex ratio. Attempts have been made to culture these bacteria in insect cell lines, as they are recalcitrant to culture under normal microbiological conditions. The diversity of bacteria associated with insects and the functional role played by them in the insect is discussed below.}, }
@article {pmid19464894, year = {2009}, author = {Sharples, GJ}, title = {For absent friends: life without recombination in mutualistic gamma-proteobacteria.}, journal = {Trends in microbiology}, volume = {17}, number = {6}, pages = {233-242}, doi = {10.1016/j.tim.2009.03.005}, pmid = {19464894}, issn = {1878-4380}, support = {BB/C514523/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; BB/F020503/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Bacterial Proteins/physiology ; Bivalvia/microbiology ; *DNA Repair ; Gammaproteobacteria/genetics/*physiology ; Insecta/microbiology ; Models, Biological ; Rec A Recombinases/physiology ; *Recombination, Genetic ; *Symbiosis ; }, abstract = {Almost all cellular organisms employ RecA orthologues to guide the strand invasion reactions necessary for DNA recombination and repair. One of the few exceptions to this orthodoxy is a group of gamma-proteobacteria flourishing in obligate intracellular symbiosis with insects and deep-sea clams. The apparent inability of these bacteria to commence the recombinational exchange process seems to confer genetic stability by preventing any further rearrangements or lateral transfer events. Although debate has centred on the absence of selected recombination functions and their impact on a fixed genomic architecture, no explanation has been offered for how bacteria survive the loss of such an integral DNA repair system. This question is addressed here by speculating on how the current repertoire of recombinases in symbiotic bacteria could enable recovery from potentially lethal injuries to the DNA template. Depending on which functions remain, several different options are plausible. The possibility that specific defects in recombination encourage radical genome erosion in mutualistic endosymbionts and other intracellular bacteria is discussed.}, }
@article {pmid19453612, year = {2009}, author = {Bengtson, P and Bastviken, D and de Boer, W and Oberg, G}, title = {Possible role of reactive chlorine in microbial antagonism and organic matter chlorination in terrestrial environments.}, journal = {Environmental microbiology}, volume = {11}, number = {6}, pages = {1330-1339}, doi = {10.1111/j.1462-2920.2009.01915.x}, pmid = {19453612}, issn = {1462-2920}, mesh = {Anti-Infective Agents/chemical synthesis/metabolism ; *Antibiosis ; Bacteria/growth &amp; development ; Chloride Peroxidase/metabolism ; Chlorine/analysis/*metabolism ; *Environmental Microbiology ; Fungi/growth &amp; development ; Hypochlorous Acid/chemical synthesis/metabolism ; Organic Chemicals/chemistry ; Plants/chemistry ; Soil/analysis ; }, abstract = {Several studies have demonstrated that extensive formation of organically bound chlorine occurs both in soil and in decaying plant material. Previous studies suggest that enzymatic formation of reactive chlorine outside cells is a major source. However, the ecological role of microbial-induced extracellular chlorination processes remains unclear. In the present paper, we assess whether or not the literature supports the hypothesis that extracellular chlorination is involved in direct antagonism against competitors for the same resources. Our review shows that it is by no means rare that biotic processes create conditions that render biocidal concentrations of reactive chlorine compounds, which suggest that extracellular production of reactive chlorine may have an important role in antagonistic microbial interactions. To test the validity, we searched the UniprotPK database for microorganisms that are known to produce haloperoxidases. It appeared that many of the identified haloperoxidases from terrestrial environments are originating from organisms that are associated with living plants or decomposing plant material. The results of the in silico screening were supported by various field and laboratory studies on natural chlorination. Hence, the ability to produce reactive chlorine seems to be especially common in environments that are known for antibiotic-mediated competition for resources (interference competition). Yet, the ability to produce haloperoxidases is also recorded, for example, for plant endosymbionts and parasites, and there is little or no empirical evidence that suggests that these organisms are antagonistic.}, }
@article {pmid19451630, year = {2009}, author = {Degnan, PH and Yu, Y and Sisneros, N and Wing, RA and Moran, NA}, title = {Hamiltonella defensa, genome evolution of protective bacterial endosymbiont from pathogenic ancestors.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {106}, number = {22}, pages = {9063-9068}, pmid = {19451630}, issn = {1091-6490}, mesh = {Base Sequence ; Enterobacteriaceae/*classification/*genetics/pathogenicity ; *Evolution, Molecular ; *Genome, Bacterial ; Genomics ; Molecular Sequence Data ; Phylogeny ; Proteome/genetics ; Symbiosis ; }, abstract = {Eukaryotes engage in a multitude of beneficial and deleterious interactions with bacteria. Hamiltonella defensa, an endosymbiont of aphids and other sap-feeding insects, protects its aphid host from attack by parasitoid wasps. Thus H. defensa is only conditionally beneficial to hosts, unlike ancient nutritional symbionts, such as Buchnera, that are obligate. Similar to pathogenic bacteria, H. defensa is able to invade naive hosts and circumvent host immune responses. We have sequenced the genome of H. defensa to identify possible mechanisms that underlie its persistence in healthy aphids and protection from parasitoids. The 2.1-Mb genome has undergone significant reduction in size relative to its closest free-living relatives, which include Yersinia and Serratia species (4.6-5.4 Mb). Auxotrophic for 8 of the 10 essential amino acids, H. defensa is reliant upon the essential amino acids produced by Buchnera. Despite these losses, the H. defensa genome retains more genes and pathways for a variety of cell structures and processes than do obligate symbionts, such as Buchnera. Furthermore, putative pathogenicity loci, encoding type-3 secretion systems, and toxin homologs, which are absent in obligate symbionts, are abundant in the H. defensa genome, as are regulatory genes that likely control the timing of their expression. The genome is also littered with mobile DNA, including phage-derived genes, plasmids, and insertion-sequence elements, highlighting its dynamic nature and the continued role horizontal gene transfer plays in shaping it.}, }
@article {pmid19435739, year = {2009}, author = {Spencer, M and Sangaralingam, A}, title = {A phylogenetic mixture model for gene family loss in parasitic bacteria.}, journal = {Molecular biology and evolution}, volume = {26}, number = {8}, pages = {1901-1908}, doi = {10.1093/molbev/msp102}, pmid = {19435739}, issn = {1537-1719}, support = {BB/E019005/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Bacteria/*genetics ; Genes, Bacterial ; *Models, Genetic ; Phylogeny ; }, abstract = {Gene families are frequently gained and lost from prokaryotic genomes. It is widely believed that the rate of loss was accelerated for some but not all gene families in lineages that became parasites or endosymbionts. This leads to a form of heterotachy that may be responsible for the poor performance of phylogeny estimation based on gene content. We describe a mixture model that accounts for this heterotachy. We show that this model fits data on the distribution of gene families across bacteria from the COG database much better than previous models. However, it still favors an artifactual tree topology in which parasites form a clade over the more plausible 16S topology. In contrast to a previous model of genome dynamics, our model suggests that the ancestral bacterium had a small genome. We suggest that models of gene family gain and loss are likely to be more useful for understanding genome dynamics than for estimating phylogenetic trees.}, }
@article {pmid19435469, year = {2009}, author = {Feldhaar, H and Gross, R}, title = {Genome degeneration affects both extracellular and intracellular bacterial endosymbionts.}, journal = {Journal of biology}, volume = {8}, number = {3}, pages = {31}, pmid = {19435469}, issn = {1475-4924}, mesh = {Animals ; Bacteria/*genetics ; Bacterial Infections/transmission ; Evolution, Molecular ; Genes, Bacterial ; Genetic Variation ; *Genome, Bacterial ; Infectious Disease Transmission, Vertical ; Insecta/genetics/*microbiology ; *Symbiosis ; }, abstract = {The obligate intracellular bacterial endosymbionts of insects are a paradigm for reductive genome evolution. A study published recently in BMC Biology demonstrates that similar evolutionary forces shaping genome structure may also apply to extracellular endosymbionts.}, }
@article {pmid19435425, year = {2009}, author = {Wernegreen, JJ and Wheeler, DE}, title = {Remaining flexible in old alliances: functional plasticity in constrained mutualisms.}, journal = {DNA and cell biology}, volume = {28}, number = {8}, pages = {371-382}, pmid = {19435425}, issn = {1557-7430}, mesh = {Animals ; Ants/*genetics/microbiology ; Bacteria/classification/*genetics/growth &amp; development ; Enterobacteriaceae/genetics/physiology ; Gene Expression Regulation ; Genetic Variation ; Host-Pathogen Interactions ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Central to any beneficial interaction is the capacity of partners to detect and respond to significant changes in the other. Recent studies of microbial mutualists show their close integration with host development, immune responses, and acclimation to a dynamic external environment. While the significance of microbial players is broadly appreciated, we are just beginning to understand the genetic, ecological, and physiological mechanisms that generate variation in symbiont functions, broadly termed "symbiont plasticity" here. Some possible mechanisms include shifts in symbiont community composition, genetic changes via DNA acquisition, gene expression fluctuations, and variation in symbiont densities. In this review, we examine mechanisms for plasticity in the exceptionally stable mutualisms between insects and bacterial endosymbionts. Despite the severe ecological and genomic constraints imposed by their specialized lifestyle, these bacteria retain the capacity to modulate functions depending on the particular requirements of the host. Focusing on the mutualism between Blochmannia and ants, we discuss the roles of gene expression fluctuations and shifts in bacterial densities in generating symbiont plasticity. This symbiont variation is best understood by considering ant colony as the host superorganism. In this eusocial host, the bacteria meet the needs of the colony and not necessarily the individual ants that house them.}, }
@article {pmid19430817, year = {2009}, author = {Datta, S and Maitra, S and Gayen, P and Sinha Babu, SP}, title = {Improved efficacy of tetracycline by acaciasides on Dirofilaria immitis.}, journal = {Parasitology research}, volume = {105}, number = {3}, pages = {697-702}, pmid = {19430817}, issn = {1432-1955}, mesh = {Animals ; Dirofilaria immitis/*drug effects ; Dirofilariasis/*drug therapy ; Dog Diseases/*drug therapy/parasitology ; Dogs ; Drug Synergism ; Female ; Filaricides/administration &amp; dosage/*therapeutic use ; Male ; Saponins/administration &amp; dosage/*therapeutic use ; Tetracycline/administration &amp; dosage/*therapeutic use ; Treatment Outcome ; Triterpenes/administration &amp; dosage/*therapeutic use ; }, abstract = {The discovery of Wolbachia, a bacterial endosymbiont that occurs in the filarial parasite and its sensitivity to tetracycline, has fostered a new initiative in the development of suitable antifilarial drugs. The present study is an attempt to investigate whether adding acaciasides (saponins from Acacia auriculiformis) to the standard dose of tetracycline would further improve the efficacy of tetracycline treatment against Dirofilaria immitis microfilariae in vivo. Treatment of microfilaremic adult dogs (body weight range 8-12 kg) with tetracycline at 10 mg/kg/day for 40 days resulted in 72% and 83% reduction in mf count on days 15 and 30, respectively, and the maximum reduction in mf count (91%) was achieved on day 75 post-treatment. However, treatment with tetracycline (10 mg/kg/day for 40 days) followed by acaciasides (10 mg/kg/day for 7 days) resulted in almost 100% clearance of mf at a faster rate on day 45 post-treatment and ensured long-term (until 4 months post-treatment) protection against microfilaremia. Data from polymerase chain reaction analysis reveals that compared to untreated dogs, in treated dogs, there was marked reduction in Wolbachia specific wsp markers in fast depleting mf population. The present data indicate that prior tetracycline treatment enhances microfilaricidal activity of saponins. This effect may be additive or synergistic as the worms are weakened by Wolbachia depletion, and these weakened microfilariae are possibly killed by the saponins.}, }
@article {pmid19419989, year = {2009}, author = {Unckless, RL and Boelio, LM and Herren, JK and Jaenike, J}, title = {Wolbachia as populations within individual insects: causes and consequences of density variation in natural populations.}, journal = {Proceedings. Biological sciences}, volume = {276}, number = {1668}, pages = {2805-2811}, pmid = {19419989}, issn = {0962-8452}, mesh = {Aging ; Animals ; Drosophila/*microbiology ; Feeding Behavior ; Female ; Male ; Sex Ratio ; Wolbachia/*physiology ; }, abstract = {The population-level dynamics of maternally transmitted endosymbionts, including reproductive parasites, depends primarily on the fitness effects and transmission fidelity of these infections. Although experimental laboratory studies have shown that within-host endosymbiont density can affect both of these factors, the existence of such effects in natural populations has not yet been documented. Using quantitative PCR, we survey the density of male-killing Wolbachia in natural populations of Drosophila innubila females from the Chiricahua Mountains of Arizona. We find that there is substantial (20 000-fold) variation in Wolbachia density among wild flies and that within-host Wolbachia density is positively correlated with both the efficacy of male killing and maternal transmission fidelity. Mean Wolbachia density increases three- to five-fold from early to late in the season. This pattern suggests that Wolbachia density declines with fly age, a conclusion corroborated by a laboratory study of Wolbachia density as a function of age. Finally, we suggest three alternative hypotheses to account for the approximately lognormal distribution of Wolbachia density among wild flies.}, }
@article {pmid19414524, year = {2009}, author = {Cordaux, R}, title = {Gene conversion maintains nonfunctional transposable elements in an obligate mutualistic endosymbiont.}, journal = {Molecular biology and evolution}, volume = {26}, number = {8}, pages = {1679-1682}, doi = {10.1093/molbev/msp093}, pmid = {19414524}, issn = {1537-1719}, mesh = {Animals ; *DNA Transposable Elements ; *Gene Conversion ; Nematoda/*microbiology/physiology ; *Symbiosis ; Wolbachia/*genetics/physiology ; }, abstract = {Long-term bacterial endosymbionts typically exhibit reduced genomes, lack genes encoding recombination functions and transposable elements, such as insertion sequences (ISs). In sharp contrast, I found that ISs constitute 2.4% of the genome of the obligate mutualistic endosymbiont Wolbachia wBm. Although no IS copy is transpositionally functional, I show that ISs persist in wBm because of frequent recombinational gene conversion (GC) homogenizing homologous IS sequences. These results not only indicate that there exists a functional recombination molecular machinery in wBm, but they also suggest that, by slowing down the rate of IS degradation and loss, GC may represent a major force influencing reductive evolution in wBm.}, }
@article {pmid19402134, year = {2009}, author = {Yancey, PH and Ishikawa, J and Meyer, B and Girguis, PR and Lee, RW}, title = {Thiotaurine and hypotaurine contents in hydrothermal-vent polychaetes without thiotrophic endosymbionts: correlation With sulfide exposure.}, journal = {Journal of experimental zoology. Part A, Ecological genetics and physiology}, volume = {311}, number = {6}, pages = {439-447}, doi = {10.1002/jez.541}, pmid = {19402134}, issn = {1932-5223}, mesh = {Adaptation, Physiological ; Animals ; Gastropoda/chemistry/*metabolism/*microbiology ; Host-Parasite Interactions/*physiology ; Hydrogen Sulfide/*metabolism ; Sulfur-Reducing Bacteria/*metabolism ; Symbiosis/physiology ; Taurine/*analogs &amp; derivatives/metabolism ; }, abstract = {Invertebrates at hydrothermal vents and cold seeps must cope with toxic H(2)S. One proposed protection mechanism involves taurine derivatives: At vents and seeps, many animals have high levels of hypotaurine and thiotaurine (a product of hypotaurine and HS), originally found in animals with thiotrophic endosymbionts. To further test the role of these compounds, we analyzed them in vent polychaetes without endosymbionts: Paralvinella sulfincola, P. palmiformis and P. pandorae (paralvinellids) and Nicomache venticola (maldanid). P. sulfincola were collected from a high temperature (42-68 degrees C) and a warm site (21-35 degrees C). P. palmiformis and pandorae were from cool sites (12-18 degrees C) and N. venticola were from a cold site (4 degrees C). H(2)S concentrations in vent effluent largely correlate with temperature. Some specimens were frozen; other ones were kept alive in laboratory chambers, with and without sulfide. Tissues were analyzed for taurine derivatives and other solutes that serve as organic osmolytes. The major osmolyte of all species was glycine. Thiotaurine contents were significantly different among all species, in the order P. sulfincola hot>P. sulfincola warm>P. pandorae>P. palmiformis>N. venticola. P. sulfincola also had high levels of sarcosine; others species had none. Sarcosine and hypotaurine contents of P. sulfincola's branchiae were higher, while glycine contents were lower, than in main body. In P. palmiformis kept in pressure chambers with sulfide, thiotaurine contents were higher and hypotaurine lower than in those kept without sulfide. These results support the hypothesis that conversion of hypotaurine to thiotaurine detoxifies sulfide in vent animals without endosymbionts.}, }
@article {pmid19400650, year = {2009}, author = {Kobayashi, DY and Crouch, JA}, title = {Bacterial/Fungal interactions: from pathogens to mutualistic endosymbionts.}, journal = {Annual review of phytopathology}, volume = {47}, number = {}, pages = {63-82}, doi = {10.1146/annurev-phyto-080508-081729}, pmid = {19400650}, issn = {0066-4286}, mesh = {Bacteria/*pathogenicity ; *Bacterial Physiological Phenomena ; Fungi/*physiology ; Host-Parasite Interactions/*physiology ; }, abstract = {A fundamental issue in biology is the question of how bacteria initiate and maintain pathogenic relationships with eukaryotic hosts. Despite billions of years of coexistence, far less is known about bacterial/fungal interactions than the equivalent associations formed by either of these types of microorganisms with higher eukaryotes. This review highlights recent research advances in the field of bacterial/fungal interactions, and provides examples of the various forms such interactions may assume, ranging from simple antagonism and parasitism to more intimate associations of pathogenesis and endosymbiosis. Information derived from the associations of bacteria and fungi in the context of natural and agronomic ecosystems is emphasized, including interactions observed from biological control systems, endosymbiotic relationships, diseases of cultivated mushrooms, and model systems that expand our understanding of human disease. The benefits of studying these systems at the molecular level are also emphasized.}, }
@article {pmid19399587, year = {2009}, author = {Walther, DM and Rapaport, D and Tommassen, J}, title = {Biogenesis of beta-barrel membrane proteins in bacteria and eukaryotes: evolutionary conservation and divergence.}, journal = {Cellular and molecular life sciences : CMLS}, volume = {66}, number = {17}, pages = {2789-2804}, pmid = {19399587}, issn = {1420-9071}, mesh = {Animals ; Bacterial Outer Membrane Proteins/chemistry/genetics/metabolism ; Bacterial Proteins/*chemistry/genetics ; Cell Membrane/chemistry ; Chloroplasts/chemistry/metabolism/ultrastructure ; Eukaryotic Cells/*chemistry ; *Evolution, Molecular ; *Gram-Negative Bacteria/chemistry/cytology/genetics ; Membrane Proteins/*chemistry/genetics/metabolism ; Mitochondrial Membranes/chemistry/metabolism ; Mitochondrial Proteins/chemistry/genetics/metabolism ; Models, Molecular ; Multiprotein Complexes/chemistry/metabolism ; *Protein Structure, Secondary ; *Protein Structure, Tertiary ; }, abstract = {Membrane-embedded beta-barrel proteins span the membrane via multiple amphipathic beta-strands arranged in a cylindrical shape. These proteins are found in the outer membranes of Gram-negative bacteria, mitochondria and chloroplasts. This situation is thought to reflect the evolutionary origin of mitochondria and chloroplasts from Gram-negative bacterial endosymbionts. beta-barrel proteins fulfil a variety of functions; among them are pore-forming proteins that allow the flux of metabolites across the membrane by passive diffusion, active transporters of siderophores, enzymes, structural proteins, and proteins that mediate protein translocation across or insertion into membranes. The biogenesis process of these proteins combines evolutionary conservation of the central elements with some noticeable differences in signals and machineries. This review summarizes our current knowledge of the functions and biogenesis of this special family of proteins.}, }
@article {pmid19397674, year = {2009}, author = {Stewart, FJ and Cavanaugh, CM}, title = {Pyrosequencing analysis of endosymbiont population structure: co-occurrence of divergent symbiont lineages in a single vesicomyid host clam.}, journal = {Environmental microbiology}, volume = {11}, number = {8}, pages = {2136-2147}, doi = {10.1111/j.1462-2920.2009.01933.x}, pmid = {19397674}, issn = {1462-2920}, mesh = {Animals ; Base Sequence ; Bivalvia/*microbiology ; Gammaproteobacteria/*classification/genetics ; Molecular Sequence Data ; Polymerase Chain Reaction ; Sequence Analysis, DNA/*methods ; Symbiosis/*genetics ; }, abstract = {Bacteria-eukaryote endosymbioses are perhaps the most pervasive co-evolutionary associations in nature. Here, intracellular chemosynthetic symbionts of deep-sea clams (Vesicomyidae) were analysed by amplicon pyrosequencing to explore how symbiont transmission mode affects the genetic diversity of the within-host symbiont population. Vesicomyid symbionts (Gammaproteobacteria) are presumed to be obligately intracellular, to undergo nearly strict vertical transmission between host generations, and to be clonal within a host. However, recent data show that vesicomyid symbionts can be acquired laterally via horizontal transfer between hosts or uptake from the environment, potentially creating opportunities for multiple symbiont strains to occupy the same host. Here, genotype-specific PCR and direct sequencing of the bacterial internal transcribed spacer initially demonstrated the co-occurrence of two symbiont strains, symA and symB (93.5% nt identity), in 8 of 118 Vesicomya sp. clams from 3 of 7 hydrothermal vent sites on the Juan de Fuca Ridge. To confirm multiple strains within individual clams, amplicon pyrosequencing of two symbiont loci was used to obtain deep-coverage measurements (mean: approximately 1500x coverage per locus per clam) of symbiont population structure. Pyrosequencing confirmed symA-symB co-occurrence for two individuals, showing the presence of both genotypes in amplicon pools. However, in the majority of clams, the endosymbiont population was remarkably homogenous, with > 99.5% of sequences collapsing into a single symbiont genotype in each clam. These results support the hypothesis that a predominantly vertical transmission strategy leads to the fixation of a single symbiont strain in most hosts. However, mixed symbiont populations do occur in vesicomyids, potentially facilitating the exchange of genetic material between divergent symbiont lineages.}, }
@article {pmid19389774, year = {2009}, author = {Ishmael, N and Hotopp, JCD and Ioannidis, P and Biber, S and Sakamoto, J and Siozios, S and Nene, V and Werren, J and Bourtzis, K and Bordenstein, SR and Tettelin, H}, title = {Extensive genomic diversity of closely related Wolbachia strains.}, journal = {Microbiology (Reading, England)}, volume = {155}, number = {Pt 7}, pages = {2211-2222}, pmid = {19389774}, issn = {1350-0872}, support = {R01 GM085163/GM/NIGMS NIH HHS/United States ; R01-GM085163-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ankyrins/genetics ; Comparative Genomic Hybridization ; DNA, Bacterial/analysis/genetics ; Drosophila melanogaster/*microbiology ; Evolution, Molecular ; Gene Transfer, Horizontal ; Genes, Bacterial ; Genetic Variation ; Genome, Bacterial ; Interspersed Repetitive Sequences ; Species Specificity ; Wolbachia/*genetics ; }, abstract = {Using microarray-based comparative genome hybridization (mCGH), the genomic content of Wolbachia pipientis wMel from Drosophila melanogaster was compared to the closely related Wolbachia from D. innubila (wInn), D. santomea (wSan), and three strains from D. simulans (wAu, wRi, wSim). A large number of auxiliary genes are identified in these five strains, with most absent/divergent genes being unique to a given strain. Each strain caused an average of approximately 60 genes to be removed from the core genome. As such, these organisms do not appear to have the streamlined genomes expected of obligate intracellular bacteria. Prophage, hypothetical and ankyrin repeat genes are over-represented in the absent/divergent genes, with 21-87% of absent/divergent genes coming from prophage regions. The only wMel region absent/divergent in all five query strains is that containing WD_0509 to WD_0511, including a DNA mismatch repair protein MutL-2, a degenerate RNase, and a conserved hypothetical protein. A region flanked by the two portions of the WO-B prophage in wMel is found in four of the five Wolbachia strains as well as on a plasmid of a rickettsial endosymbiont of Ixodes scapularis, suggesting lateral gene transfer between these two obligate intracellular species. Overall, these insect-associated Wolbachia have highly mosaic genomes, with lateral gene transfer playing an important role in their diversity and evolution.}, }
@article {pmid19383035, year = {2009}, author = {Wolfgang, A and Markus, R and Dimitrios, A and Christian, S}, title = {Evidence for low-titre infections in insect symbiosis: Wolbachia in the bark beetle Pityogenes chalcographus (Coleoptera, Scolytinae).}, journal = {Environmental microbiology}, volume = {11}, number = {8}, pages = {1923-1933}, doi = {10.1111/j.1462-2920.2009.01914.x}, pmid = {19383035}, issn = {1462-2920}, support = {P 21147/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics/metabolism ; DNA Fingerprinting ; Polymerase Chain Reaction/methods ; *Symbiosis ; Weevils/*microbiology ; Wolbachia/classification/*isolation &amp; purification ; }, abstract = {Wolbachia are obligatory endosymbiotic alpha-proteobacteria found in many insect species. They are maternally transmitted and often exhibit reproductive phenotypes like cytoplasmic incompatibility. Pityogenes chalcographus is a bark beetle causing severe damage in spruce stands. Its European populations are divided into several mitochondrial clades separated by partial crossing barriers. In this study, we tested a large sample set covering the natural range of the beetle in Europe for the presence of Wolbachia and associations between infection pattern and mitotypes using a highly sensitive nested PCR technique. 35.5% of the individuals were infected with the endosymbiont and two distinct strains were identified. Both strains occur in low titre not accessible by conventional detection methods. The infections are present all over Europe, unlikely to cause the partial crossing barriers in this host and uncoupled from mitochondrial clades. This pattern is indicative for populations evolving towards endosymbiont loss and for repeated intraspecific horizontal transfer of Wolbachia. Alternatively, the low-titre infections found in P. chalcographus are yet another example for Wolbachia that can persist in host species at low densities and frequencies.}, }
@article {pmid19380463, year = {2009}, author = {Slamovits, CH and Keeling, PJ}, title = {Evolution of ultrasmall spliceosomal introns in highly reduced nuclear genomes.}, journal = {Molecular biology and evolution}, volume = {26}, number = {8}, pages = {1699-1705}, doi = {10.1093/molbev/msp081}, pmid = {19380463}, issn = {1537-1719}, mesh = {Cell Nucleus/*genetics ; Cryptophyta/cytology/*genetics/physiology ; *Evolution, Molecular ; Genome ; *Introns ; Spliceosomes/*genetics ; Symbiosis ; }, abstract = {Intron reduction and loss is a significant component of genome compaction in many eukaryotic lineages, including yeasts, microsporidia, and some nucleomorphs. Nucleomorphs are the extremely reduced relicts of algal endosymbiont nuclei found in two lineages, cryptomonads and chlorarachniophytes. In cryptomonads, introns are rare or even lost altogether. In contrast, the nucleomorph of the chlorarachniophyte Bigelowiella natans contains the smallest nuclear genome known but paradoxically also retained over 800 tiny spliceosomal introns, ranging from 18 to 21 nt in length. Because introns have not been described in any other chlorarachniophyte nucleomorph, we do not know when these introns were reduced or whether they have been lost in other lineages. To gain insight into the evolution of these unique introns, we sequenced more than 150 spliceosomal introns in the nucleomorph of the chlorarachniophyte Gymnochlora stellata and compared size distribution, sequence features, and patterns of gain/loss. To clarify the possible relationship between intron size and splicing efficiency, we also analyzed the outcome of 580 splicing events. Overall, these data indicate that the radical intron size reduction took place in the ancestor of all extant chlorarachniophytes and that although most introns have been retained through this reductive process, intron loss has also occurred. We also show that intron size is not static, and splicing is not determined strictly by size, but that size does play a strong role in splicing efficiency, likely as part of a combination of sequence features and size.}, }
@article {pmid19379544, year = {2009}, author = {Specht, S and Wanji, S}, title = {New insights into the biology of filarial infections.}, journal = {Journal of helminthology}, volume = {83}, number = {2}, pages = {199-202}, doi = {10.1017/S0022149X09344922}, pmid = {19379544}, issn = {1475-2697}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Elephantiasis, Filarial/drug therapy/*prevention &amp; control ; Filaricides/*therapeutic use ; Humans ; Onchocerciasis/drug therapy/*prevention &amp; control ; }, abstract = {Recent successes in the control of lymphatic filariasis and onchocerciasis need continuing research in order to sustain the achievements and to develop further tools to tackle the new questions that arise when only reduced infection prevalences prevail. In this regard, in a symposium held at the Xth European Multicolloquium of Parasitology (August 2008, Paris) questions such as the impact of filarial immunosuppression, and its lack following filarial control, on the outcome of co-infections were addressed, as were new approaches to treatment with promising drugs such as moxidectin or the antibiotic chemotherapy against Wolbachia endosymbionts in filariae. In particular, longer treatment courses of doxycycline could be carried out by community-directed treatment at high coverage, thus potentially allowing its use in restricted areas with suboptimal responses to ivermectin against onchocerciasis, or in areas with co-infection by loiasis where onchocerciasis or lymphatic filariasis need to be controlled. New, more potent drugs, or eventually vaccines, will be of importance because in many vector-filarial parasite relationships worldwide, transmission efficacy increases with low numbers of ingested microfilariae, and since ivermectin may render treated hosts more susceptible to new infection.}, }
@article {pmid19378410, year = {2008}, author = {Gómez-Valero, L and Latorre, A and Gil, R and Gadau, J and Feldhaar, H and Silva, FJ}, title = {Patterns and rates of nucleotide substitution, insertion and deletion in the endosymbiont of ants Blochmannia floridanus.}, journal = {Molecular ecology}, volume = {17}, number = {19}, pages = {4382-4392}, doi = {10.1111/j.1365-294x.2008.03912.x}, pmid = {19378410}, issn = {0962-1083}, mesh = {Animals ; Ants/classification/*genetics/*physiology ; Base Sequence ; DNA Transposable Elements ; Ecosystem ; Florida ; Genome ; Phylogeny ; Polymerase Chain Reaction ; *Polymorphism, Single Nucleotide ; Sequence Deletion ; Symbiosis/*genetics ; }, abstract = {Genome reduction is a general process that has been studied in numerous symbiotic bacteria associated with insects. We investigated the last stages of genome degradation in Blochmannia floridanus, a mutualistic bacterial endosymbiont of the ant Camponotus floridanus. We determined the tempo (rates of insertion and deletion) and mode (size and number of insertion-deletion events) of the process in the last 200,000 years by analysing a total of 16 intergenic regions in several strains of this endosymbiont from different ant populations. We provide the first calculation of the reduction rate for noncoding DNA in this endosymbiont (2.2 x 10(-8) lost nucleotides/site/year) and compare it with the rate of loss in other species. Our results confirm, as it has been observed in other organisms like Buchnera aphidicola or Rickettsia spp., that deletions larger than one nucleotide can still appear in advanced stages of genome reduction and that a substitutional deletion bias exists. However, this bias is not due to a higher proportion of deletion over insertion events but to a few deletion events being larger than the rest. Moreover, we detected a substitutional AT bias that is probably responsible for the increase in the number of the small and moderate indel events in the last stages of genome reduction. Accordingly, we found intrapopulational polymorphisms for the detected microsatellites in contrast to the stability associated with these in free-living bacteria such as Escherichia coli.}, }
@article {pmid19377060, year = {2009}, author = {Hempel, F and Bullmann, L and Lau, J and Zauner, S and Maier, UG}, title = {ERAD-derived preprotein transport across the second outermost plastid membrane of diatoms.}, journal = {Molecular biology and evolution}, volume = {26}, number = {8}, pages = {1781-1790}, doi = {10.1093/molbev/msp079}, pmid = {19377060}, issn = {1537-1719}, mesh = {Diatoms/*cytology/*genetics/metabolism ; Endoplasmic Reticulum/metabolism ; Intracellular Membranes/metabolism ; Plastids/chemistry/*genetics/*metabolism ; *Protein Transport ; }, abstract = {The diatom Phaeodactylum tricornutum harbors a plastid that is surrounded by four membranes and evolved by way of secondary endosymbiosis. Like land plants, most of its plastid proteins are encoded as preproteins on the nuclear genome of the host cell and are resultantly redirected into the organelle. Because two more membranes are present in diatoms than the one pair surrounding primary plastids, the targeting situation is obviously different and more complex. In this work, we focus on preprotein transport across the second outermost plastid membrane -- an issue that was experimentally inaccessible until now. We provide first indications that our hypothesis of an ERAD (ER-associated degradation)-derived preprotein transport system might be correct. Our data demonstrate that the symbiont-specific Der1 proteins, sDer1-1 and sDer1-2, form an oligomeric complex within the second outermost membrane of the complex plastid. Moreover, we present first evidence that the complex interacts with transit peptides of preproteins being transported across this membrane into the periplastidal compartment but not with transit peptides of stromal-targeted proteins. Thus, the sDer1 complex might have an additional role in discriminating preproteins that are transported across the two outermost membranes from preproteins directed across all four membranes of the complex plastid. Altogether, our studies of the symbiont-specific ERAD-like machinery of diatoms suggest that a preexisting cellular machinery was recycled to fulfill a novel function during the transition of a former free-living eukaryote into a secondary endosymbiont.}, }
@article {pmid19376923, year = {2009}, author = {Zouache, K and Voronin, D and Tran-Van, V and Mavingui, P}, title = {Composition of bacterial communities associated with natural and laboratory populations of Asobara tabida infected with Wolbachia.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {11}, pages = {3755-3764}, pmid = {19376923}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; *Biodiversity ; Cluster Analysis ; DNA Fingerprinting ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Electrophoresis, Polyacrylamide Gel ; France ; Gram-Negative Bacterial Infections/microbiology/*veterinary ; Hymenoptera/*microbiology ; Molecular Sequence Data ; Nucleic Acid Denaturation ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; }, abstract = {Asobara tabida wasps are fly endoparasitoids that naturally harbor three Wolbachia strains, which induce cytoplasmic incompatibility and control oogenesis. To investigate whether other bacteria play a role in wasp biology, we surveyed the bacterial communities of wild A. tabida populations originating from different regions of France and of laboratory colonies using PCR-denaturing gradient gel electrophoresis and culture methods. Proteobacteria and Firmicutes were found to be the main phyla represented in these populations. Among these were several cultured and uncultured representatives of the genera Acetobacter, Acidomonas, Bacillus, Brevibacillus, Duganella, Herbaspirillum, Pseudomonas, Staphylococcus, and Streptococcus. In addition to Wolbachia, wild individuals harbored Rickettsia, which tended to be lost when insects were reared in the laboratory. The antibiotic treatment used to generate wasp sublines singly infected with Wolbachia also affected the overall bacterial composition, with most fingerprint sequences being characteristic of the family Enterobacteriaceae. We also screened for potentially heritable endosymbionts by PCR and fluorescence in situ hybridization in stable laboratory lines, with only Wolbachia being consistently found in wasp ovaries.}, }
@article {pmid19368218, year = {2009}, author = {Pollack, K and Balazs, K and Ogunseitan, O}, title = {Proteomic assessment of caffeine effects on coral symbionts.}, journal = {Environmental science &amp; technology}, volume = {43}, number = {6}, pages = {2085-2091}, doi = {10.1021/es802617f}, pmid = {19368218}, issn = {0013-936X}, mesh = {Algal Proteins/genetics/metabolism ; Animals ; Anthozoa/*physiology ; Caffeine/*toxicity ; Eukaryota/*drug effects/*metabolism ; Gene Expression Regulation/drug effects ; Proteome ; Symbiosis ; Time Factors ; Water Pollutants, Chemical/*toxicity ; }, abstract = {Caffeine isthe mostwidely consumed and excreted psychoactive drug in the world. It is a ubiquitous tracer of urban wastewater, but its ecological effects are notwell understood. We hypothesized that caffeine exposure is associated with coral bleaching. Here we report the effects of caffeine on four species of coral algae endosymbionts belonging to three widely distributed clades: Clade A Symbiodinium microadriaticum (A), Clade B Symbiodinium sp. from Aiptasia pallida (B6), Clade B Symbiodinium sp. from Pseudoterogorgia bipinnata (B7), and Clade C Symbiodinium goreaui (C). To assess the effect of caffeine on algal physiology we used two-dimensional polyacrylamide gel electrophoresis and peptide mass spectrometry to identify protein sensitive to caffeine exposure. The results show several upregulated and several downregulated polypeptides in all algae species tested. The heat-shock proteins are among the commonly affected proteins, suggesting that caffeine exposure associated with sewage discharge into natural waters may exacerbate the effects of stress from other environmental factors such as changes in ocean temperature and pH.}, }
@article {pmid19361881, year = {2009}, author = {Dieterich, C and Sommer, RJ}, title = {How to become a parasite - lessons from the genomes of nematodes.}, journal = {Trends in genetics : TIG}, volume = {25}, number = {5}, pages = {203-209}, doi = {10.1016/j.tig.2009.03.006}, pmid = {19361881}, issn = {0168-9525}, mesh = {Adaptation, Physiological/genetics ; Animals ; Evolution, Molecular ; Gene Transfer, Horizontal ; *Genome, Helminth ; Genomics/*methods ; Helminthiasis, Animal/parasitology ; Humans ; Life Cycle Stages/genetics ; Nematoda/classification/*genetics/growth &amp; development ; Nematode Infections/parasitology ; Phylogeny ; Plant Diseases/parasitology ; }, abstract = {The phylum Nematoda is biologically diverse; it includes parasites of plants and animals in addition to free-living taxa. To date, the genomes of six nematodes have been sequenced. Comparative analyses of these ecologically diverse nematodes are beginning to reveal the mechanisms by which parasites arise and how they evolve. Here, we discuss some emerging principles for the mechanisms and evolution of parasitism. First, horizontal gene transfer represents a common theme in nematode parasites. Second, the human parasite Brugia malayi lost otherwise essential genes most probably owing to the mutualistic relationship with a bacterial endosymbiont. Finally, some parasitic features evolved under free-living conditions. A recent study revealed a conserved endocrine mechanism controlling the formation of dauer and infective larvae in nematodes.}, }
@article {pmid19353951, year = {2009}, author = {Junker, K and Barbuto, M and Casiraghi, M and Martin, C and Uni, S and Boomker, J and Bain, O}, title = {Litomosa chiropterorum Ortlepp, 1932 (Nematoda: Filarioidea) from a South African miniopterid: redescription, Wolbachia screening and phylogenetic relationships with Litomosoides.}, journal = {Parasite (Paris, France)}, volume = {16}, number = {1}, pages = {43-50}, doi = {10.1051/parasite/2009161043}, pmid = {19353951}, issn = {1252-607X}, mesh = {Animals ; Chiroptera/*parasitology ; Female ; Filarioidea/*anatomy &amp; histology/*classification/microbiology ; Male ; *Phylogeny ; Prevalence ; South Africa ; Wolbachia/isolation &amp; purification ; }, abstract = {69 Miniopterus notalensis, type host of the onchocercid Litomosa chiropterorum, were collected in caves in the Western Province and Gauteng Province, South Africa. The prevalence of these filariae was about 50 %. The microfilaria is folded, as in other Litomosa and an area rugosa composed of cuticular bosses is present in the male posterior region. L. chiropterorum is close to the species parasitic in other Miniopterus spp. and some Rhinolophus spp. from Africa, Madagascar and Europe; it is unique with the expanded anterior extremity and the four cephalic submedian bosses. The molecular analysis of L. chiropterorum, the first done with Litomosa species from a bat, supports the hypothesis that Litomosa and Litomosoides, which have an exceptionally large buccal capsule in common, form a group in which Litomosa has a basal position. Interestingly, L. chiropterorum does not harbour Wolbachia, as proved with immunohistological staining and PCR screening using the 16S rDNA gene as target. This is contrary to L. westi from rodents and the majority of the Litomosoides species parasitic in bats or rodents. The absence of Wolbachia in a filarioid group considered ancient based on traditional and molecular approaches opens interesting scenarios on the evolution of the endosymbionts spread through filarial lineages.}, }
@article {pmid19351090, year = {2009}, author = {Machado-Ferreira, E and Piesman, J and Zeidner, NS and Soares, CA}, title = {Francisella-like endosymbiont DNA and Francisella tularensis virulence-related genes in Brazilian ticks (Acari: Ixodidae).}, journal = {Journal of medical entomology}, volume = {46}, number = {2}, pages = {369-374}, doi = {10.1603/033.046.0224}, pmid = {19351090}, issn = {0022-2585}, mesh = {Amino Acid Sequence ; Animals ; Brazil ; DNA, Bacterial/isolation &amp; purification ; Francisella tularensis/*genetics/isolation &amp; purification/pathogenicity ; *Genes, Bacterial ; Ixodidae/*microbiology ; Molecular Sequence Data ; *Symbiosis ; }, abstract = {Ticks are vectors of a variety of pathogens, including Francisella tularensis. Bacteria in the genus Francisella have been identified mostly in the Northern Hemisphere and include tick endosymbionts. Francisella has never been described in Brazil, where Amblyomma spp. ticks are known as the vector of many bacterial zoonotic pathogens. In the present work, we have identified bacterial DNA sequences with identity to Francisella genes in Amblyomma dubitatum Neumann Dermacentor nitens (Neumann), and Rhipicephalus microplus (Canestrini) in Brazil. DNA fragments with homology to Francisella spp. 16S rDNA and the tul4 gene were polymerase chain reaction amplified from tick DNA samples collected in Minas Gerais and Mato Grosso states. These sequences were 96-99% identical to the reported sequences for Francisella-like tick endosymbionts (FLEs). Sequences similar to the tularemia agent F. tularensis pathogenicity island gene iglC and its regulatory gene mglA also were identified in FLEs.}, }
@article {pmid19346359, year = {2009}, author = {Caro, A and Got, P and Bouvy, M and Troussellier, M and Gros, O}, title = {Effects of long-term starvation on a host bivalve (Codakia orbicularis, Lucinidae) and its symbiont population.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {10}, pages = {3304-3313}, pmid = {19346359}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*growth &amp; development/metabolism ; Bivalvia/*microbiology ; Colony Count, Microbial ; Gills/*microbiology/*ultrastructure ; Microscopy, Electron, Transmission ; *Starvation ; }, abstract = {The bivalve Codakia orbicularis, hosting sulfur-oxidizing gill endosymbionts, was starved (in artificial seawater filtered through a 0.22-mum-pore-size membrane) for a long-term experiment (4 months). The effects of starvation were observed using transmission electron microscopy, fluorescence in situ hybridization and catalyzed reporter deposition (CARD-FISH), and flow cytometry to monitor the anatomical and physiological modifications in the gill organization of the host and in the symbiotic population housed in bacteriocytes. The abundance of the symbiotic population decreased through starvation, with a loss of one-third of the bacterial population each month, as shown by CARD-FISH. At the same time, flow cytometry revealed significant changes in the physiology of symbiotic cells, with a decrease in cell size and modifications to the nucleic acid content, while most of the symbionts maintained a high respiratory activity (measured using the 5-cyano-2,3-ditolyl tetrazolium chloride method). Progressively, the number of symbiont subpopulations was reduced, and the subsequent multigenomic state, characteristic of this symbiont in freshly collected clams, turned into one and five equivalent genome copies for the two remaining subpopulations after 3 months. Concomitant structural modifications appeared in the gill organization. Lysosymes became visible in the bacteriocytes, while large symbionts disappeared, and bacteriocytes were gradually replaced by granule cells throughout the entire lateral zone. Those data suggested that host survival under these starvation conditions was linked to symbiont digestion as the main nutritional source.}, }
@article {pmid19344532, year = {2009}, author = {Suzuki, K and Nakanishi, H and Bower, J and Yoder, DW and Osteryoung, KW and Miyagishima, SY}, title = {Plastid chaperonin proteins Cpn60 alpha and Cpn60 beta are required for plastid division in Arabidopsis thaliana.}, journal = {BMC plant biology}, volume = {9}, number = {}, pages = {38}, pmid = {19344532}, issn = {1471-2229}, mesh = {Arabidopsis/*genetics/metabolism ; Arabidopsis Proteins/genetics/*metabolism ; Chaperonin 60/genetics/*metabolism ; Chloroplasts/*metabolism ; Cloning, Molecular ; DNA, Plant/genetics ; Gene Expression Regulation, Plant ; Genes, Plant ; Genome, Plant ; Mutagenesis, Insertional ; Mutation ; Phylogeny ; Plant Leaves/genetics/metabolism ; Plant Proteins/metabolism ; Plants, Genetically Modified/genetics/metabolism ; Sequence Alignment ; }, abstract = {BACKGROUND: Plastids arose from a free-living cyanobacterial endosymbiont and multiply by binary division as do cyanobacteria. Plastid division involves nucleus-encoded homologs of cyanobacterial division proteins such as FtsZ, MinD, MinE, and ARC6. However, homologs of many other cyanobacterial division genes are missing in plant genomes and proteins of host eukaryotic origin, such as a dynamin-related protein, PDV1 and PDV2 are involved in the division process. Recent identification of plastid division proteins has started to elucidate the similarities and differences between plastid division and cyanobacterial cell division. To further identify new proteins that are required for plastid division, we characterized previously and newly isolated plastid division mutants of Arabidopsis thaliana.<br><br>RESULTS: Leaf cells of two mutants, br04 and arc2, contain fewer, larger chloroplasts than those of wild type. We found that ARC2 and BR04 are identical to nuclear genes encoding the plastid chaperonin 60 alpha (ptCpn60alpha) and chaperonin 60 beta (ptCpn60beta) proteins, respectively. In both mutants, plastid division FtsZ ring formation was partially perturbed though the level of FtsZ2-1 protein in plastids of ptcpn60beta mutants was similar to that in wild type. Phylogenetic analyses showed that both ptCpn60 proteins are derived from ancestral cyanobacterial proteins. The A. thaliana genome encodes two members of ptCpn60alpha family and four members of ptCpn60beta family respectively. We found that a null mutation in ptCpn60alpha abolished greening of plastids and resulted in an albino phenotype while a weaker mutation impairs plastid division and reduced chlorophyll levels. The functions of at least two ptCpn60beta proteins are redundant and the appearance of chloroplast division defects is dependent on the number of mutant alleles.<br><br>CONCLUSION: Our results suggest that both ptCpn60alpha and ptCpn60beta are required for the formation of a normal plastid division apparatus, as the prokaryotic counterparts are required for assembly of the cell division apparatus. Since moderate reduction of ptCpn60 levels impaired normal FtsZ ring formation but not import of FtsZ into plastids, it is suggested that the proper levels of ptCpn60 are required for folding of stromal plastid division proteins and/or regulation of FtsZ polymer dynamics.}, }
@article {pmid19343224, year = {2009}, author = {Toft, C and Williams, TA and Fares, MA}, title = {Genome-wide functional divergence after the symbiosis of proteobacteria with insects unraveled through a novel computational approach.}, journal = {PLoS computational biology}, volume = {5}, number = {4}, pages = {e1000344}, pmid = {19343224}, issn = {1553-7358}, mesh = {Animals ; Ants/*genetics ; Aphids/*genetics ; Archaea/*genetics ; Chromosome Mapping/*methods ; Genetic Variation/genetics ; Genomic Islands/*genetics ; *Selection, Genetic ; Symbiosis/*genetics ; }, abstract = {Symbiosis has been among the most important evolutionary steps to generate biological complexity. The establishment of symbiosis required an intimate metabolic link between biological systems with different complexity levels. The strict endo-cellular symbiotic bacteria of insects are beautiful examples of the metabolic coupling between organisms belonging to different kingdoms, a eukaryote and a prokaryote. The host (eukaryote) provides the endosymbiont (prokaryote) with a stable cellular environment while the endosymbiont supplements the host's diet with essential metabolites. For such communication to take place, endosymbionts' genomes have suffered dramatic modifications and reconfigurations of proteins' functions. Two of the main modifications, loss of genes redundant for endosymbiotic bacteria or the host and bacterial genome streamlining, have been extensively studied. However, no studies have accounted for possible functional shifts in the endosymbiotic proteomes. Here, we develop a simple method to screen genomes for evidence of functional divergence between two species clusters, and we apply it to identify functional shifts in the endosymbiotic proteomes. Despite the strong effects of genetic drift in the endosymbiotic systems, we unexpectedly identified genes to be under stronger selective constraints in endosymbionts of aphids and ants than in their free-living bacterial relatives. These genes are directly involved in supplementing the host's diet with essential metabolites. A test of functional divergence supports a strong relationship between the endosymbiosis and the functional shifts of proteins involved in the metabolic communication with the insect host. The correlation between functional divergence in the endosymbiotic bacterium and the ecological requirements of the host uncovers their intimate biochemical and metabolic communication and provides insights on the role of symbiosis in generating species diversity.}, }
@article {pmid19343208, year = {2009}, author = {Brownlie, JC and Cass, BN and Riegler, M and Witsenburg, JJ and Iturbe-Ormaetxe, I and McGraw, EA and O'Neill, SL}, title = {Evidence for metabolic provisioning by a common invertebrate endosymbiont, Wolbachia pipientis, during periods of nutritional stress.}, journal = {PLoS pathogens}, volume = {5}, number = {4}, pages = {e1000368}, pmid = {19343208}, issn = {1553-7374}, mesh = {Analysis of Variance ; Animals ; Drosophila melanogaster/growth &amp; development/*microbiology/physiology ; Female ; Fertility ; Iron/*metabolism ; Male ; Statistics, Nonparametric ; *Stress, Physiological ; *Symbiosis ; Wolbachia/metabolism/*physiology ; }, abstract = {Wolbachia are ubiquitous inherited endosymbionts of invertebrates that invade host populations by modifying host reproductive systems. However, some strains lack the ability to impose reproductive modification and yet are still capable of successfully invading host populations. To explain this paradox, theory predicts that such strains should provide a fitness benefit, but to date none has been detected. Recently completed genome sequences of different Wolbachia strains show that these bacteria may have the genetic machinery to influence iron utilization of hosts. Here we show that Wolbachia infection can confer a positive fecundity benefit for Drosophila melanogaster reared on iron-restricted or -overloaded diets. Furthermore, iron levels measured from field-collected flies indicated that nutritional conditions in the field were overall comparable to those of flies reared in the laboratory on restricted diets. These data suggest that Wolbachia may play a previously unrecognized role as nutritional mutualists in insects.}, }
@article {pmid19329661, year = {2009}, author = {Jin, C and Ren, X and Rasgon, JL}, title = {The virulent Wolbachia strain wMelPop efficiently establishes somatic infections in the malaria vector Anopheles gambiae.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {10}, pages = {3373-3376}, pmid = {19329661}, issn = {1098-5336}, support = {R21 AI070178/AI/NIAID NIH HHS/United States ; R21 AI070178-02/AI/NIAID NIH HHS/United States ; R21AI070178/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anopheles/*microbiology ; Microbial Viability ; Wolbachia/*growth &amp; development/*isolation &amp; purification ; }, abstract = {Wolbachia pipientis bacteria are maternally inherited endosymbionts that are of interest to control the Anopheles mosquito vectors of malaria. Wolbachia does not infect Anopheles mosquitoes in nature, although cultured Anopheles cells can be infected. Here, we show that the virulent Wolbachia strain wMelPop can survive and replicate when injected into female Anopheles gambiae adults, but the somatic infections established are avirulent. These in vivo data suggest that stable Wolbachia infections of Anopheles may be possible.}, }
@article {pmid19329646, year = {2009}, author = {Stoll, S and Feldhaar, H and Gross, R}, title = {Promoter characterization in the AT-rich genome of the obligate endosymbiont "Candidatus Blochmannia floridanus".}, journal = {Journal of bacteriology}, volume = {191}, number = {11}, pages = {3747-3751}, pmid = {19329646}, issn = {1098-5530}, mesh = {DNA-Directed RNA Polymerases/genetics ; Enterobacteriaceae/*genetics ; Genome, Bacterial/*genetics ; Heat-Shock Proteins/genetics ; Promoter Regions, Genetic/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sigma Factor/genetics ; Transcription Initiation Site ; }, abstract = {The characterization of transcriptional start sites of 14 genes encoded by the extremely AT-rich genome of "Candidatus Blochmannia floridanus" revealed a high degree of conservation with the RpoD promoter consensus sequence of the free-living relative Escherichia coli. Moreover, in agreement with the presence of the alternative heat shock sigma factor RpoH in "Ca. Blochmannia," typical RpoH-dependent promoters were identified. However, no heat shock response resembling that of E. coli could be detected in "Ca. Blochmannia."}, }
@article {pmid19307609, year = {2009}, author = {Gros, PA and Tenaillon, O}, title = {Selection for chaperone-like mediated genetic robustness at low mutation rate: impact of drift, epistasis and complexity.}, journal = {Genetics}, volume = {182}, number = {2}, pages = {555-564}, pmid = {19307609}, issn = {0016-6731}, mesh = {Adaptation, Physiological ; *Epistasis, Genetic ; Evolution, Molecular ; *Genetic Drift ; Models, Biological ; Molecular Chaperones/*metabolism ; *Mutagenesis ; Mutation ; Phenotype ; *Selection, Genetic ; Time Factors ; }, abstract = {Genetic robustness is defined as the constancy of a phenotype in the face of deleterious mutations. Overexpression of chaperones, to assist the folding of proteins carrying deleterious mutations, is so far one of the most accepted molecular mechanisms enhancing genetic robustness. Most theories on the evolution of robustness have focused on the implications of high mutation rate. Here we show that genetic drift, which is modulated by population size, organism complexity, and epistasis, can be a sufficient force to select for chaperone-mediated genetic robustness. Using an exact analytical solution, we also show that selection for costly genetic robustness leads to a paradox: the decrease of population fitness on long timescales and the long-term dependency on robustness mechanisms. We suggest that selection for genetic robustness could be universal and not restricted to high mutation rate organisms such as RNA viruses. The evolution of the endosymbiont Buchnera illustrates this selection mechanism and its paradox: the increased dependency on chaperones mediating genetic robustness. Our model explains why most chaperones might have become essential even in optimal growth conditions.}, }
@article {pmid19305500, year = {2009}, author = {Allen, JM and Light, JE and Perotti, MA and Braig, HR and Reed, DL}, title = {Mutational meltdown in primary endosymbionts: selection limits Muller's ratchet.}, journal = {PloS one}, volume = {4}, number = {3}, pages = {e4969}, pmid = {19305500}, issn = {1932-6203}, mesh = {Animals ; Bacteria/*genetics/metabolism ; Evolution, Molecular ; Humans ; Insecta/*microbiology ; Likelihood Functions ; *Mutation ; Phylogeny ; *Selection, Genetic ; Symbiosis/*physiology ; }, abstract = {BACKGROUND: Primary bacterial endosymbionts of insects (p-endosymbionts) are thought to be undergoing the process of Muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. If this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. Although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that Muller's ratchet may be slowed or even stopped over time. For example, selection may act to slow the effects of Muller's ratchet by removing slightly deleterious mutations before they go to fixation thereby causing a decrease in nucleotide substitutions rates in older p-endosymbiont lineages.<br><br>To determine whether selection is slowing the effects of Muller's ratchet, we determined the age of the Candidatus Riesia/sucking louse assemblage and analyzed the nucleotide substitution rates of several p-endosymbiont lineages that differ in the length of time that they have been associated with their insect hosts. We find that Riesia is the youngest p-endosymbiont known to date, and has been associated with its louse hosts for only 13-25 My. Further, it is the fastest evolving p-endosymbiont with substitution rates of 19-34% per 50 My. When comparing Riesia to other insect p-endosymbionts, we find that nucleotide substitution rates decrease dramatically as the age of endosymbiosis increases.<br><br>CONCLUSIONS/SIGNIFICANCE: A decrease in nucleotide substitution rates over time suggests that selection may be limiting the effects of Muller's ratchet by removing individuals with the highest mutational loads and decreasing the rate at which new mutations become fixed. This countering effect of selection could slow the overall rate of endosymbiont extinction.}, }
@article {pmid19304816, year = {2009}, author = {Fukatsu, T and Hosokawa, T and Koga, R and Nikoh, N and Kato, T and Hayama, S and Takefushi, H and Tanaka, I}, title = {Intestinal endocellular symbiotic bacterium of the macaque louse Pedicinus obtusus: Distinct endosymbiont origins in anthropoid primate lice and the old world monkey louse.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {11}, pages = {3796-3799}, pmid = {19304816}, issn = {1098-5336}, mesh = {Animals ; Anoplura/*microbiology ; Bacteria/*classification/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Bacterial Proteins/genetics ; Chaperonin 60/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Epithelium/microbiology ; Female ; Gastrointestinal Tract/*microbiology ; Molecular Sequence Data ; Ovary/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {A symbiotic bacterium of the macaque louse, Pedicinus obtusus, was characterized. The symbiont constituted a gammaproteobacterial lineage distinct from the symbionts of anthropoid primate lice, localized in the midgut epithelium and the ovaries and exhibiting AT-biased genes and accelerated molecular evolution. The designation "Candidatus Puchtella pedicinophila" was proposed for it.}, }
@article {pmid19300496, year = {2009}, author = {Landmann, F and Orsi, GA and Loppin, B and Sullivan, W}, title = {Wolbachia-mediated cytoplasmic incompatibility is associated with impaired histone deposition in the male pronucleus.}, journal = {PLoS pathogens}, volume = {5}, number = {3}, pages = {e1000343}, pmid = {19300496}, issn = {1553-7374}, mesh = {Animals ; Animals, Genetically Modified ; Cell Nucleus ; Drosophila/genetics/*microbiology ; Embryo, Nonmammalian ; Female ; Fluorescent Antibody Technique ; Histones/*metabolism ; Host-Pathogen Interactions/*genetics ; Infertility, Male/genetics/microbiology ; Male ; Microscopy, Confocal ; Rickettsia Infections/*genetics ; Spermatozoa/pathology ; Wolbachia/*physiology ; }, abstract = {Wolbachia is a bacteria endosymbiont that rapidly infects insect populations through a mechanism known as cytoplasmic incompatibility (CI). In CI, crosses between Wolbachia-infected males and uninfected females produce severe cell cycle defects in the male pronucleus resulting in early embryonic lethality. In contrast, viable progeny are produced when both parents are infected (the Rescue cross). An important consequence of CI-Rescue is that infected females have a selective advantage over uninfected females facilitating the rapid spread of Wolbachia through insect populations. CI disrupts a number of prophase and metaphase events in the male pronucleus, including Cdk1 activation, chromosome condensation, and segregation. Here, we demonstrate that CI disrupts earlier interphase cell cycle events. Specifically, CI delays the H3.3 and H4 deposition that occurs immediately after protamine removal from the male pronucleus. In addition, we find prolonged retention of the replication factor PCNA in the male pronucleus into metaphase, indicating progression into mitosis with incompletely replicated DNA. We propose that these CI-induced interphase defects in de novo nucleosome assembly and replication are the cause of the observed mitotic condensation and segregation defects. In addition, these interphase chromosome defects likely activate S-phase checkpoints, accounting for the previously described delays in Cdk1 activation. These results have important implications for the mechanism of Rescue and other Wolbachia-induced phenotypes.}, }
@article {pmid19289597, year = {2009}, author = {Stewart, FJ and Young, CR and Cavanaugh, CM}, title = {Evidence for homologous recombination in intracellular chemosynthetic clam symbionts.}, journal = {Molecular biology and evolution}, volume = {26}, number = {6}, pages = {1391-1404}, doi = {10.1093/molbev/msp049}, pmid = {19289597}, issn = {1537-1719}, mesh = {Algorithms ; Animals ; Bacteria/*genetics ; Bacterial Physiological Phenomena ; Base Composition ; Base Sequence ; Bayes Theorem ; Bivalvia/*microbiology ; Data Interpretation, Statistical ; Genetic Variation ; Models, Genetic ; Molecular Sequence Data ; Phylogeny ; *Recombination, Genetic ; Sequence Alignment ; *Symbiosis ; }, abstract = {Homologous recombination is a fundamental mechanism for the genetic diversification of free-living bacteria. However, recombination may be limited in endosymbiotic bacteria, as these taxa are locked into an intracellular niche and may rarely encounter sources of foreign DNA. This study tested the hypothesis that vertically transmitted endosymbionts of deep-sea clams (Bivalvia: Vesicomyidae) show little or no evidence of recombination. Phylogenetic analysis of 13 loci distributed across the genomes of 14 vesicomyid symbionts revealed multiple, well-supported inconsistencies among gene tree topologies, and maximum likelihood-based tests rejected a hypothesis of shared evolutionary history (linkage) among loci. Further, multiple statistical methods confirmed the presence of recombination by detecting intragenic breakpoints in two symbiont loci. Recombination may be confined to a subset of vesicomyid symbionts, as some clades showed high levels of genomic stability, whereas others showed clear patterns of homologous exchange. Notably, a mosaic genome is present in symB, a symbiont lineage shown to have been acquired laterally (i.e., nonvertically) by Vesicomya sp. JdF clams. The majority of loci analyzed here supported a tight sister clustering of symB with the symbiont of a host species from the Mid-Atlantic Ridge, whereas others placed symB in a clade with symA, the dominant phylotype of V. sp. JdF clams. This result raises the hypothesis that lateral symbiont transfer between hosts may facilitate recombination by bringing divergent symbiont lineages into contact. Together, the data show that homologous recombination contributes to the diversification of vesicomyid clam symbionts, despite the intracellular lifestyle of these bacteria.}, }
@article {pmid19286793, year = {2009}, author = {Lackner, G and Möbius, N and Scherlach, K and Partida-Martinez, LP and Winkler, R and Schmitt, I and Hertweck, C}, title = {Global distribution and evolution of a toxinogenic Burkholderia-Rhizopus symbiosis.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {9}, pages = {2982-2986}, pmid = {19286793}, issn = {1098-5336}, mesh = {Bacterial Toxins/*biosynthesis ; Burkholderia/chemistry/*classification/isolation &amp; purification/*physiology ; DNA, Bacterial/genetics ; Phylogeny ; Rhizopus/growth &amp; development/*physiology ; Sequence Analysis, DNA ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; *Symbiosis ; }, abstract = {Toxinogenic endobacteria were isolated from a collection of Rhizopus spp. representing highly diverse geographic origins and ecological niches. All endosymbionts belonged to the Burkholderia rhizoxinica complex according to matrix-assisted laser desorption ionization-time of flight biotyping and multilocus sequence typing, suggesting a common ancestor. Comparison of host and symbiont phylogenies provides insights into possible cospeciation and horizontal-transmission events.}, }
@article {pmid19281454, year = {2009}, author = {Gueguen, G and Rolain, JM and Zchori-Fein, E and Vavre, F and Fleury, F and Raoult, D}, title = {Molecular detection and identification of Rickettsia endosymbiont in different biotypes of Bemisia tabaci.}, journal = {Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases}, volume = {15 Suppl 2}, number = {}, pages = {271-272}, doi = {10.1111/j.1469-0691.2008.02231.x}, pmid = {19281454}, issn = {1469-0691}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Citrate (si)-Synthase/genetics ; Cluster Analysis ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Hemiptera/*microbiology/physiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*classification/genetics/*isolation &amp; purification/physiology ; Sequence Analysis, DNA ; *Symbiosis ; }, }
@article {pmid19272014, year = {2009}, author = {Engelstädter, J and Hurst, GD}, title = {What use are male hosts? The dynamics of maternally inherited bacteria showing sexual transmission or male killing.}, journal = {The American naturalist}, volume = {173}, number = {5}, pages = {E159-70}, doi = {10.1086/597375}, pmid = {19272014}, issn = {1537-5323}, mesh = {Animals ; Arthropods/*microbiology ; Female ; Male ; *Models, Biological ; Sex Ratio ; Sexual Behavior, Animal ; *Symbiosis ; }, abstract = {Closely related pathogens and parasites often have distinctly different strategies for transmission. In some cases, presence of one potential mode of transmission reduces the rate of or forbids another. In these cases, one can ask what the conditions are that favor the use of one mode of transmission over the other. We constructed a mathematical model to examine this issue for the case of maternally inherited endosymbionts of insects. Here, killing males (to enhance transmission through the female line by reducing sibling competition) and retaining live males as a vehicle for sexual transmission are mutually exclusive strategies. Our model indicates that sexual transmission of a maternally inherited parasite can exclude a male-killing strain, provided that a sexually transmitted infection can take over an infection by a male-killing strain either following exposure or when male killing is incomplete and sexual transmission is efficient. The presence of sexual transmission may also explain why secondary symbionts do not degrade toward the evolution of male killing but remain as "beneficial partners" to both male and female hosts. This stabilization may be fundamental to the evolution toward obligate mutualism, and thus it is important in the ecology and evolution of many arthropod groups.}, }
@article {pmid19271205, year = {2009}, author = {Mitreva, M and Smant, G and Helder, J}, title = {Role of horizontal gene transfer in the evolution of plant parasitism among nematodes.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {532}, number = {}, pages = {517-535}, doi = {10.1007/978-1-60327-853-9_30}, pmid = {19271205}, issn = {1064-3745}, support = {AI46593/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Biological Evolution ; Cellulase/genetics ; Ecosystem ; Expressed Sequence Tags ; *Gene Transfer, Horizontal ; Genes, Helminth ; Host-Parasite Interactions/genetics ; Models, Genetic ; Nematoda/*genetics/*pathogenicity ; Phylogeny ; Plants/*parasitology ; Symbiosis/genetics ; }, abstract = {Horizontal gene transfer (HGT) implies the non-sexual exchange of genetic material between species - in some cases even across kingdoms. Although common among Bacteria and Archaea, HGTs from pro- to eukaryotes and between eukaryotes were thought to be extremely rare. Recent studies on intracellular bacteria and their hosts seriously question this view. Recipient organisms could benefit from HGT as new gene packages could allow them to broaden or change their diet, colonize new habitats, or survive conditions that previously would have been lethal.About a decade ago, plant parasitic nematodes were shown to produce and secrete cellulases. Prior to this, animals were thought to fully depend on microbial symbionts for the breakdown of plant cell walls. This discovery prompted Keen and Roberts (1) to hypothesize that the ability of nematodes to parasitize plants was acquired by HGT from soil bacteria to (ancestral) bacterivorous nematodes. Since the identification of the first nematode cellulases, many more plant cell wall-degrading enzymes (CWDE) have been identified in a range of plant parasitic nematode species.Here we discuss a number of criteria that can be used to underpin an HGT claim. HGT requires close physical contact between donor and recipient, and this could be achieved in, for example, a symbiont-host, or a trophic relationship. The former type of relationship was indeed shown to potentially result in the transfer of genetic material (e.g., Brugia malayi and Wolbachia). However, currently known endosymbionts of nematodes may not be the source of CWDEs. Remarkably, all cellulases discovered so far within the order Tylenchida belong to a single glycoside hydrolase family (GHF5). A range of soil bacteria harbours GHF5 cellulases, but of course nothing can be said about the gene content of soil bacteria at the time HGT took place (if at all). We suggest that characterisation of cellulases (and other CWDEs) and their genomic organisation in more basal (facultative) plant parasitic Tylenchida is needed to find out if CWDEs were indeed acquired via HGT from bacteria. A more complete picture about the evolution of CWDEs among plant parasitic Tylenchida will require a detailed characterisation of two - so far - fully unexplored basal suborders, Tylenchina and Criconematina. Finally, we performed a computational high-throughput identification of potential HGT candidates (including ones unrelated to CWDEs) in plant parasitic nematodes using a genomics approach.}, }
@article {pmid19270135, year = {2009}, author = {Geissinger, O and Herlemann, DP and Mörschel, E and Maier, UG and Brune, A}, title = {The ultramicrobacterium "Elusimicrobium minutum" gen. nov., sp. nov., the first cultivated representative of the termite group 1 phylum.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {9}, pages = {2831-2840}, pmid = {19270135}, issn = {1098-5336}, mesh = {Anaerobiosis ; Animals ; Bacteria/*classification/cytology/genetics/*isolation &amp; purification ; Bacterial Typing Techniques ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gastrointestinal Tract/microbiology ; Genes, rRNA ; Isoptera/*microbiology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; }, abstract = {Insect intestinal tracts harbor several novel, deep-rooting clades of as-yet-uncultivated bacteria whose biology is typically completely unknown. Here, we report the isolation of the first representative of the termite group 1 (TG1) phylum from sterile-filtered gut homogenates of a humivorous scarab beetle larva. Strain Pei191(T) is a mesophilic, obligately anaerobic ultramicrobacterium with a gram-negative cell envelope. Cells are typically rod shaped, but cultures are pleomorphic in all growth phases (0.3 to 2.5 microm long and 0.17 to 0.3 microm wide). The isolate grows heterotrophically on sugars and ferments D-galactose, D-glucose, D-fructose, D-glucosamine, and N-acetyl-D-glucosamine to acetate, ethanol, hydrogen, and alanine as major products but only if amino acids are present in the medium. PCR-based screening and comparative 16S rRNA gene sequence analysis revealed that strain Pei191(T) belongs to the "intestinal cluster," a lineage of hitherto uncultivated bacteria present in arthropod and mammalian gut systems. It is only distantly related to the previously described so-called "endomicrobia" lineage, which comprises mainly uncultivated endosymbionts of termite gut flagellates. We propose the name "Elusimicrobium minutum" gen. nov., sp. nov. (type strain, Pei191(T) = ATCC BAA-1559(T) = JCM 14958(T)) for the first isolate of this deep-branching lineage and the name "Elusimicrobia" phyl. nov. for the former TG1 phylum.}, }
@article {pmid19270083, year = {2009}, author = {Barabote, RD and Xie, G and Leu, DH and Normand, P and Necsulea, A and Daubin, V and Médigue, C and Adney, WS and Xu, XC and Lapidus, A and Parales, RE and Detter, C and Pujic, P and Bruce, D and Lavire, C and Challacombe, JF and Brettin, TS and Berry, AM}, title = {Complete genome of the cellulolytic thermophile Acidothermus cellulolyticus 11B provides insights into its ecophysiological and evolutionary adaptations.}, journal = {Genome research}, volume = {19}, number = {6}, pages = {1033-1043}, pmid = {19270083}, issn = {1088-9051}, mesh = {Actinomycetales/*genetics/growth &amp; development ; Adaptation, Physiological/*genetics ; Bacterial Proteins/genetics/metabolism ; Base Composition/genetics ; Chromosomes, Bacterial/genetics ; DNA, Bacterial/chemistry/genetics ; Ecology ; *Evolution, Molecular ; Flagella/genetics/physiology ; *Genome, Bacterial ; Hot Temperature ; Principal Component Analysis ; Sequence Analysis, DNA ; }, abstract = {We present here the complete 2.4-Mb genome of the cellulolytic actinobacterial thermophile Acidothermus cellulolyticus 11B. New secreted glycoside hydrolases and carbohydrate esterases were identified in the genome, revealing a diverse biomass-degrading enzyme repertoire far greater than previously characterized and elevating the industrial value of this organism. A sizable fraction of these hydrolytic enzymes break down plant cell walls, and the remaining either degrade components in fungal cell walls or metabolize storage carbohydrates such as glycogen and trehalose, implicating the relative importance of these different carbon sources. Several of the A. cellulolyticus secreted cellulolytic and xylanolytic enzymes are fused to multiple tandemly arranged carbohydrate binding modules (CBM), from families 2 and 3. For the most part, thermophilic patterns in the genome and proteome of A. cellulolyticus were weak, which may be reflective of the recent evolutionary history of A. cellulolyticus since its divergence from its closest phylogenetic neighbor Frankia, a mesophilic plant endosymbiont and soil dweller. However, ribosomal proteins and noncoding RNAs (rRNA and tRNAs) in A. cellulolyticus showed thermophilic traits suggesting the importance of adaptation of cellular translational machinery to environmental temperature. Elevated occurrence of IVYWREL amino acids in A. cellulolyticus orthologs compared to mesophiles and inverse preferences for G and A at the first and third codon positions also point to its ongoing thermoadaptation. Additional interesting features in the genome of this cellulolytic, hot-springs-dwelling prokaryote include a low occurrence of pseudogenes or mobile genetic elements, an unexpected complement of flagellar genes, and the presence of three laterally acquired genomic islands of likely ecophysiological value.}, }
@article {pmid19265485, year = {2009}, author = {Kurz, M and Iturbe-Ormaetxe, I and Jarrott, R and Shouldice, SR and Wouters, MA and Frei, P and Glockshuber, R and O'Neill, SL and Heras, B and Martin, JL}, title = {Structural and functional characterization of the oxidoreductase alpha-DsbA1 from Wolbachia pipientis.}, journal = {Antioxidants &amp; redox signaling}, volume = {11}, number = {7}, pages = {1485-1500}, doi = {10.1089/ars.2008.2420}, pmid = {19265485}, issn = {1557-7716}, mesh = {Base Sequence ; Crystallography, X-Ray ; DNA Primers ; Oxidation-Reduction ; Oxidoreductases/chemistry/*metabolism ; Protein Conformation ; Protein Folding ; Structure-Activity Relationship ; Wolbachia/*enzymology ; }, abstract = {The alpha-proteobacterium Wolbachia pipientis is a highly successful intracellular endosymbiont of invertebrates that manipulates its host's reproductive biology to facilitate its own maternal transmission. The fastidious nature of Wolbachia and the lack of genetic transformation have hampered analysis of the molecular basis of these manipulations. Structure determination of key Wolbachia proteins will enable the development of inhibitors for chemical genetics studies. Wolbachia encodes a homologue (alpha-DsbA1) of the Escherichia coli dithiol oxidase enzyme EcDsbA, essential for the oxidative folding of many exported proteins. We found that the active-site cysteine pair of Wolbachia alpha-DsbA1 has the most reducing redox potential of any characterized DsbA. In addition, Wolbachia alpha-DsbA1 possesses a second disulfide that is highly conserved in alpha-proteobacterial DsbAs but not in other DsbAs. The alpha-DsbA1 structure lacks the characteristic hydrophobic features of EcDsbA, and the protein neither complements EcDsbA deletion mutants in E. coli nor interacts with EcDsbB, the redox partner of EcDsbA. The surface characteristics and redox profile of alpha-DsbA1 indicate that it probably plays a specialized oxidative folding role with a narrow substrate specificity. This first report of a Wolbachia protein structure provides the basis for future chemical genetics studies.}, }
@article {pmid19265021, year = {2009}, author = {Harmon, JP and Moran, NA and Ives, AR}, title = {Species response to environmental change: impacts of food web interactions and evolution.}, journal = {Science (New York, N.Y.)}, volume = {323}, number = {5919}, pages = {1347-1350}, doi = {10.1126/science.1167396}, pmid = {19265021}, issn = {1095-9203}, mesh = {Animals ; Aphids/genetics/microbiology/*physiology ; Biological Evolution ; Buchnera/genetics/physiology ; Coleoptera/*physiology ; *Ecosystem ; *Food Chain ; *Hot Temperature ; Models, Biological ; Population Density ; Population Dynamics ; Population Growth ; Predatory Behavior ; Symbiosis ; }, abstract = {How environmental change affects species abundances depends on both the food web within which species interact and their potential to evolve. Using field experiments, we investigated both ecological and evolutionary responses of pea aphids (Acyrthosiphon pisum), a common agricultural pest, to increased frequency of episodic heat shocks. One predator species ameliorated the decrease in aphid population growth with increasing heat shocks, whereas a second predator did not, with this contrast caused by behavioral differences between predators. We also compared aphid strains with stably inherited differences in heat tolerance caused by bacterial endosymbionts and showed the potential for rapid evolution for heat-shock tolerance. Our results illustrate how ecological and evolutionary complexities should be incorporated into predictions of the consequences of environmental change for species' populations.}, }
@article {pmid19257899, year = {2009}, author = {Delgado, AM and Cook, JM}, title = {Effects of a sex-ratio distorting endosymbiont on mtDNA variation in a global insect pest.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {49}, pmid = {19257899}, issn = {1471-2148}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Mitochondrial/*genetics ; Evolution, Molecular ; Female ; Genes, Insect ; Genetic Variation ; *Genetics, Population ; Geography ; Haplotypes ; Male ; Mitochondria/genetics ; Moths/*genetics/microbiology ; Phenotype ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; *Sex Ratio ; Symbiosis ; *Wolbachia/genetics ; }, abstract = {BACKGROUND: Patterns of mtDNA variation within a species reflect long-term population structure, but may also be influenced by maternally inherited endosymbionts, such as Wolbachia. These bacteria often alter host reproductive biology and can drive particular mtDNA haplotypes through populations. We investigated the impacts of Wolbachia infection and geography on mtDNA variation in the diamondback moth, a major global pest whose geographic distribution reflects both natural processes and transport via human agricultural activities.<br><br>RESULTS: The mtDNA phylogeny of 95 individuals sampled from 10 countries on four continents revealed two major clades. One contained only Wolbachia-infected individuals from Malaysia and Kenya, while the other contained only uninfected individuals, from all countries including Malaysia and Kenya. Within the uninfected group was a further clade containing all individuals from Australasia and displaying very limited sequence variation. In contrast, a biparental nuclear gene phylogeny did not have infected and uninfected clades, supporting the notion that maternally-inherited Wolbachia are responsible for the mtDNA pattern. Only about 5% (15/306) of our global sample of individuals was infected with the plutWB1 isolate and even within infected local populations, many insects were uninfected. Comparisons of infected and uninfected isofemale lines revealed that plutWB1 is associated with sex ratio distortion. Uninfected lines have a 1:1 sex ratio, while infected ones show a 2:1 female bias.<br><br>CONCLUSION: The main correlate of mtDNA variation in P. xylostella is presence or absence of the plutWB1 infection. This is associated with substantial sex ratio distortion and the underlying mechanisms deserve further study. In contrast, geographic origin is a poor predictor of moth mtDNA sequences, reflecting human activity in moving the insects around the globe. The exception is a clade of Australasian individuals, which may reflect a bottleneck during their recent introduction to this region.}, }
@article {pmid19220345, year = {2009}, author = {Moya, A and Gil, R and Latorre, A}, title = {The evolutionary history of symbiotic associations among bacteria and their animal hosts: a model.}, journal = {Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases}, volume = {15 Suppl 1}, number = {}, pages = {11-13}, doi = {10.1111/j.1469-0691.2008.02689.x}, pmid = {19220345}, issn = {1469-0691}, mesh = {Animals ; Bacteria/*growth &amp; development ; *Bacterial Physiological Phenomena ; *Evolution, Molecular ; Gene Deletion ; Genome, Bacterial ; Sequence Deletion ; *Symbiosis ; Weevils/*microbiology ; }, abstract = {A model to explain the evolutionary history of animal-bacteria obligatory mutualistic symbiosis is presented. Dispensability of genes and genetic isolation are key factors in the reduction process of these bacterial genomes. Major steps in such genome reductive evolution, leading towards primary endosimbiosis, and the possibility of complementation or replacement by a secondary symbiont are also indicated. Yet, we need to understand what happens at the beginning of the adaptative process towards an obligate mutualistic relationship. For this purpose, we propose to sequence the complete genome of SOPE, the primary endosymbiont of the rice weevil.}, }
@article {pmid19245710, year = {2009}, author = {Yutin, N and Wolf, MY and Wolf, YI and Koonin, EV}, title = {The origins of phagocytosis and eukaryogenesis.}, journal = {Biology direct}, volume = {4}, number = {}, pages = {9}, pmid = {19245710}, issn = {1745-6150}, support = {//Intramural NIH HHS/United States ; }, mesh = {Actins/chemistry ; Amino Acid Sequence ; Animals ; Archaea/genetics/metabolism ; Bacteria/enzymology ; Conserved Sequence ; Eukaryotic Cells/*cytology/enzymology ; Microfilament Proteins/chemistry ; Molecular Sequence Data ; Monomeric GTP-Binding Proteins/chemistry/genetics ; *Phagocytosis ; Phylogeny ; Proteomics ; Sequence Homology, Amino Acid ; Symbiosis ; ras Proteins/genetics ; }, abstract = {BACKGROUND: Phagocytosis, that is, engulfment of large particles by eukaryotic cells, is found in diverse organisms and is often thought to be central to the very origin of the eukaryotic cell, in particular, for the acquisition of bacterial endosymbionts including the ancestor of the mitochondrion.<br><br>RESULTS: Comparisons of the sets of proteins implicated in phagocytosis in different eukaryotes reveal extreme diversity, with very few highly conserved components that typically do not possess readily identifiable prokaryotic homologs. Nevertheless, phylogenetic analysis of those proteins for which such homologs do exist yields clues to the possible origin of phagocytosis. The central finding is that a subset of archaea encode actins that are not only monophyletic with eukaryotic actins but also share unique structural features with actin-related proteins (Arp) 2 and 3. All phagocytic processes are strictly dependent on remodeling of the actin cytoskeleton and the formation of branched filaments for which Arp2/3 are responsible. The presence of common structural features in Arp2/3 and the archaeal actins suggests that the common ancestors of the archaeal and eukaryotic actins were capable of forming branched filaments, like modern Arp2/3. The Rho family GTPases that are ubiquitous regulators of phagocytosis in eukaryotes appear to be of bacterial origin, so assuming that the host of the mitochondrial endosymbiont was an archaeon, the genes for these GTPases come via horizontal gene transfer from the endosymbiont or in an earlier event.<br><br>CONCLUSION: The present findings suggest a hypothetical scenario of eukaryogenesis under which the archaeal ancestor of eukaryotes had no cell wall (like modern Thermoplasma) but had an actin-based cytoskeleton including branched actin filaments that allowed this organism to produce actin-supported membrane protrusions. These protrusions would facilitate accidental, occasional engulfment of bacteria, one of which eventually became the mitochondrion. The acquisition of the endosymbiont triggered eukaryogenesis, in particular, the emergence of the endomembrane system that eventually led to the evolution of modern-type phagocytosis, independently in several eukaryotic lineages.}, }
@article {pmid19245183, year = {2008}, author = {Sen, D and Appunu, C and Singh, RK}, title = {Regulation of urease in Bradyrhizobium colonizing green gram (Vigna radiata (L.) Wilczek).}, journal = {Indian journal of experimental biology}, volume = {46}, number = {12}, pages = {846-851}, pmid = {19245183}, issn = {0019-5189}, mesh = {Ammonia/pharmacology ; Enzyme Activation/drug effects ; Fabaceae/*enzymology/genetics ; *Gene Expression Regulation, Enzymologic ; *Gene Expression Regulation, Plant ; Urease/genetics/*metabolism ; }, abstract = {In the present study attempts have been made to characterize urease expression in slow growing Bradyrhizobium strains TAL442 and MO5 which are endosymbionts of green gram (Vigna radiata (L.)Wilczek). It was found that urease activity in vegetative cells of both the strains was inducible unlike their fast growing counterparts. Mode of regulation in TAL442 was governed by presence of ammonia. Urease expression was also detectable in bacteroids of both the strains which was not influenced by presence of external nickel chloride in high concentration, a situation detrimental to the vegetative cells.}, }
@article {pmid19231282, year = {2009}, author = {Figueroa, RI and Bravo, I and Fraga, S and Garcés, E and Llaveria, G}, title = {The life history and cell cycle of Kryptoperidinium foliaceum, a dinoflagellate with two eukaryotic nuclei.}, journal = {Protist}, volume = {160}, number = {2}, pages = {285-300}, doi = {10.1016/j.protis.2008.12.003}, pmid = {19231282}, issn = {1618-0941}, mesh = {Animals ; *Cell Cycle ; Cell Nucleus/*chemistry ; Cell Size ; Dinoflagellida/chemistry/cytology/*growth &amp; development ; *Life Cycle Stages ; }, abstract = {Kryptoperidinium foliaceum is a binucleate dinoflagellate that contains an endosymbiont nucleus of diatom origin. However, it is unknown whether the binucleate condition is permanent or not and how the diatom nucleus behaves during the life history processes. In this sense, it is also unknown if there is a sexual cycle or a resting stage during the life history of this species, two key aspects necessary to understand the life history strategy of this dinoflagellate. To answer these questions, life history and cell cycle studies were performed with the following results: (i) Kryptoperidinium foliaceum has a sexual cycle and in the dinoflagellate strains studied, the binucleate condition is permanent. Sexuality in the host was confirmed by the presence of fusing gamete pairs and planozygotes in clonal cultures (revealing homothallism), but signs of meiosis in the endosymbiont were not observed. The endosymbiont nucleus likely fuses first, because fusing gamete pairs were found to have two dinoflagellate nuclei but only one endosymbiont nucleus. After complete gamete fusion, the planozygotes had apparently normal endosymbiont and dinoflagellate nuclei. (ii) Asexual division studies using flow cytometry showed that the S phase in the endosymbiont (diatom) nucleus starts 6-8h later than in the host nucleus, but there was no evidence of mitosis in the former. (iii) Sexual and asexual cysts were formed in culture. Neither cysts from natural samples nor those formed in culture exhibited a dormancy period before germination.}, }
@article {pmid19229488, year = {2009}, author = {Jeong, G and Lee, K and Choi, J and Hwang, S and Park, B and Kim, W and Choi, Y and Park, I and Kim, J}, title = {Incidence of Wolbachia and Cardinium endosymbionts in the Osmia community in Korea.}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {47}, number = {1}, pages = {28-32}, pmid = {19229488}, issn = {1976-3794}, mesh = {Animals ; Bacteroidetes/genetics/*isolation &amp; purification ; Bees/genetics/*microbiology/parasitology ; Diptera/genetics/microbiology ; Gene Transfer, Horizontal ; Korea ; Mites/genetics/microbiology ; Pest Control, Biological ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sex Ratio ; *Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Sex ratio distorting endosymbionts induce reproductive anomalies in their arthropod hosts. They have recently been paid much attention as firstly texts of evolution of host-symbiont relationships and secondly potential biological control agents to control arthropod pests. Among such organisms, Wolbachia and Cardinium bacteria are well characterized. This study aims at probing such bacteria in the Osmia community to evaluate their potential utilization to control arthropod pests. Among 17 PCR tested species, Osmia cornifrons and a parasitic fly are infected with Wolbachia and a mite species is infected with Cardinium. Phylogenetic tree analyses suggest that horizontal transfer of the bacteria occurred between phylogenetically distant hosts.}, }
@article {pmid19228189, year = {2009}, author = {Vorburger, C and Sandrock, C and Gouskov, A and Castañeda, LE and Ferrari, J}, title = {Genotypic variation and the role of defensive endosymbionts in an all-parthenogenetic host-parasitoid interaction.}, journal = {Evolution; international journal of organic evolution}, volume = {63}, number = {6}, pages = {1439-1450}, doi = {10.1111/j.1558-5646.2009.00660.x}, pmid = {19228189}, issn = {1558-5646}, mesh = {Animals ; Aphids/microbiology/*parasitology/physiology ; Biological Evolution ; Enterobacteriaceae/*physiology ; *Genetic Variation ; Genotype ; Host-Parasite Interactions/*physiology ; Models, Genetic ; *Parthenogenesis ; Symbiosis/*physiology ; Wasps/*physiology ; }, abstract = {Models of host-parasite coevolution predict pronounced genetic dynamics if resistance and infectivity are genotype-specific or associated with costs, and if selection is fueled by sufficient genetic variation. We addressed these assumptions in the black bean aphid, Aphis fabae, and its parasitoid Lysiphlebus fabarum. Parasitoid genotypes differed in infectivity and host clones exhibited huge variation for susceptibility. This variation occurred at two levels. Clones harboring Hamiltonella defensa, a bacterial endosymbiont known to protect pea aphids against parasitoids, enjoyed greatly reduced susceptibility, yet clones without H. defensa also exhibited significant variation. Although there was no evidence for genotype-specificity in the H. defensa-free clones' interaction with parasitoids, we found such evidence in clones containing the bacterium. This suggests that parasitoid genotypes differ in their ability to overcome H. defensa, resulting in an apparent host x parasitoid genotype interaction that may in fact be due to an underlying symbiont x parasitoid genotype interaction. Aphid susceptibility to parasitoids correlated negatively with fecundity and rate of increase, due to H. defensa-bearing clones being more fecund on average. Hence, possessing symbionts may also be favorable in the absence of parasitoids, which raises the question why H. defensa does not go to fixation and highlights the need to develop new models to understand the dynamics of endosymbiont-mediated coevolution.}, }
@article {pmid19226322, year = {2009}, author = {Haselkorn, TS and Markow, TA and Moran, NA}, title = {Multiple introductions of the Spiroplasma bacterial endosymbiont into Drosophila.}, journal = {Molecular ecology}, volume = {18}, number = {6}, pages = {1294-1305}, doi = {10.1111/j.1365-294X.2009.04085.x}, pmid = {19226322}, issn = {1365-294X}, mesh = {Animals ; Bacterial Typing Techniques ; Bayes Theorem ; *Biological Evolution ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Drosophila/genetics/*microbiology ; Genetic Variation ; Genetics, Population ; Haplotypes ; Mitochondria/genetics ; *Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Spiroplasma/classification/*genetics ; *Symbiosis ; }, abstract = {Bacterial endosymbionts are common in insects and can have dramatic effects on their host's evolution. So far, the only heritable symbionts found in Drosophila have been Wolbachia and Spiroplasma. While the incidence and effects of Wolbachia have been studied extensively, the prevalence and significance of Spiroplasma infections in Drosophila are less clear. These small, gram-positive, helical bacteria infect a diverse array of plant and arthropod hosts, conferring a variety of fitness effects. Male-killing Spiroplasma are known from certain Drosophila species; however, in others, Spiroplasma appear not to affect sex ratio. Previous studies have identified different Spiroplasma haplotypes in Drosophila populations, although no extensive surveys have yet been reported. We used a multilocus sequence analysis to reconstruct a robust Spiroplasma endosymbiont phylogeny, assess genetic diversity, and look for evidence of recombination. Six loci were sequenced from over 65 Spiroplasma-infected individuals from nine different Drosophila species. Analysis of these sequences reveals at least five separate introductions of four phylogenetically distinct Spiroplasma haplotypes, indicating that more extensive sampling will likely reveal an even greater Spiroplasma endosymbiont diversity. Patterns of variation in Drosophila mitochondrial haplotypes in Spiroplasma-infected and uninfected flies imply imperfect vertical transmission in host populations and possible horizontal transmission.}, }
@article {pmid19225559, year = {2009}, author = {Sussman, M and Mieog, JC and Doyle, J and Victor, S and Willis, BL and Bourne, DG}, title = {Vibrio zinc-metalloprotease causes photoinactivation of coral endosymbionts and coral tissue lesions.}, journal = {PloS one}, volume = {4}, number = {2}, pages = {e4511}, pmid = {19225559}, issn = {1932-6203}, mesh = {Animals ; Anthozoa/*microbiology ; Bacterial Infections/enzymology ; Metalloproteases/*physiology ; Photosystem II Protein Complex/*antagonists &amp; inhibitors ; Vibrio/enzymology/*pathogenicity ; Zinc ; }, abstract = {BACKGROUND: Coral diseases are emerging as a serious threat to coral reefs worldwide. Of nine coral infectious diseases, whose pathogens have been characterized, six are caused by agents from the family Vibrionacae, raising questions as to their origin and role in coral disease aetiology.<br><br>Here we report on a Vibrio zinc-metalloprotease causing rapid photoinactivation of susceptible Symbiodinium endosymbionts followed by lesions in coral tissue. Symbiodinium photosystem II inactivation was diagnosed by an imaging pulse amplitude modulation fluorometer in two bioassays, performed by exposing Symbiodinium cells and coral juveniles to non-inhibited and EDTA-inhibited supernatants derived from coral white syndrome pathogens.<br><br>CONCLUSION/SIGNIFICANCE: These findings demonstrate a common virulence factor from four phylogenetically related coral pathogens, suggesting that zinc-metalloproteases may play an important role in Vibrio pathogenicity in scleractinian corals.}, }
@article {pmid19224954, year = {2009}, author = {Ishikawa, M and Fujiwara, M and Sonoike, K and Sato, N}, title = {Orthogenomics of photosynthetic organisms: bioinformatic and experimental analysis of chloroplast proteins of endosymbiont origin in Arabidopsis and their counterparts in Synechocystis.}, journal = {Plant &amp; cell physiology}, volume = {50}, number = {4}, pages = {773-788}, doi = {10.1093/pcp/pcp027}, pmid = {19224954}, issn = {1471-9053}, mesh = {Algal Proteins/genetics ; Amino Acid Sequence ; Arabidopsis/*genetics ; Arabidopsis Proteins/genetics ; Chloroplasts/*genetics ; Computational Biology/methods ; Evolution, Molecular ; Genes, Plant ; Genome, Chloroplast ; Genome, Plant ; Genomics/*methods ; Molecular Sequence Data ; Mutagenesis ; Phylogeny ; RNA, Plant/genetics ; Sequence Alignment ; Symbiosis/*genetics ; Synechocystis/*genetics ; }, abstract = {Chloroplasts are descendents of a cyanobacterial endosymbiont, but many chloroplast protein genes of endosymbiont origin are encoded by the nucleus. The chloroplast-cyanobacteria relationship is a typical target of orthogenomics, an analytical method that focuses on the relationship of orthologous genes. Here, we present results of a pilot study of functional orthogenomics, combining bioinformatic and experimental analyses, to identify nuclear-encoded chloroplast proteins of endosymbiont origin (CPRENDOs). Phylogenetic profiling based on complete clustering of all proteins in 17 organisms, including eight cyanobacteria and two photosynthetic eukaryotes, was used to deduce 65 protein groups that are conserved in all oxygenic autotrophs analyzed but not in non-oxygenic organisms. With the exception of 28 well-characterized protein groups, 56 Arabidopsis proteins and 43 Synechocystis proteins in the 37 conserved homolog groups were analyzed. Green fluorescent protein (GFP) targeting experiments indicated that 54 Arabidopsis proteins were targeted to plastids. Expression of 39 Arabidopsis genes was promoted by light. Among the 40 disruptants of Synechocystis, 22 showed phenotypes related to photosynthesis. Arabidopsis mutants in 21 groups, including those reported previously, showed phenotypes. Characteristics of pulse amplitude modulation fluorescence were markedly different in corresponding mutants of Arabidopsis and Synechocystis in most cases. We conclude that phylogenetic profiling is useful in finding CPRENDOs, but the physiological functions of orthologous genes may be different in chloroplasts and cyanobacteria.}, }
@article {pmid19223921, year = {2009}, author = {White, JA and Kelly, SE and Perlman, SJ and Hunter, MS}, title = {Cytoplasmic incompatibility in the parasitic wasp Encarsia inaron: disentangling the roles of Cardinium and Wolbachia symbionts.}, journal = {Heredity}, volume = {102}, number = {5}, pages = {483-489}, pmid = {19223921}, issn = {1365-2540}, support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; K12 GM00708-06/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteroidetes/*physiology ; Extrachromosomal Inheritance ; Female ; *Host-Pathogen Interactions ; Male ; Reproduction ; Sex Ratio ; *Symbiosis ; Wasps/*genetics/*microbiology/physiology ; Wolbachia/*physiology ; }, abstract = {Many bacterial endosymbionts of insects are capable of manipulating their host's reproduction for their own benefit. The most common strategy of manipulation is cytoplasmic incompatibility (CI), in which embryonic mortality results from matings between uninfected females and infected males. In contrast, embryos develop normally in infected females, whether or not their mate is infected, and infected progeny are produced. In this way, the proportion of infected females increases in the insect population, thereby promoting the spread of the maternally inherited bacteria. However, what happens when multiple endosymbionts inhabit the same host? The parasitoid wasp Encarsia inaron is naturally infected with two unrelated endosymbionts, Cardinium and Wolbachia, both of which have been documented to cause CI in other insects. Doubly infected wasps show the CI phenotype. We differentially cured E. inaron of each endosymbiont, and crossed hosts of different infection status to determine whether either or both bacteria caused the observed CI phenotype in this parasitoid, and whether the two symbionts interacted within their common host. We found that Wolbachia caused CI in E. inaron, but Cardinium did not. We did not find evidence that Cardinium was able to modify or rescue Wolbachia-induced CI, nor did we find that Cardinium caused progeny sex ratio distortion, leaving the role of Cardinium in E. inaron a mystery.}, }
@article {pmid19219460, year = {2009}, author = {Desneux, N and Barta, RJ and Hoelmer, KA and Hopper, KR and Heimpel, GE}, title = {Multifaceted determinants of host specificity in an aphid parasitoid.}, journal = {Oecologia}, volume = {160}, number = {2}, pages = {387-398}, pmid = {19219460}, issn = {1432-1939}, mesh = {Animals ; Aphids/genetics/microbiology/*parasitology ; Host-Parasite Interactions ; Oviposition/physiology ; Phylogeny ; Reproduction/physiology ; Species Specificity ; Wasps/*physiology ; }, abstract = {The host specificity of insect parasitoids and herbivores is thought to be shaped by a suite of traits that mediate host acceptance and host suitability. We conducted laboratory experiments to identify mechanisms shaping the host specificity of the aphid parasitoid Binodoxys communis. Twenty species of aphids were exposed to B. communis females in microcosms, and detailed observations and rearing studies of 15 of these species were done to determine whether patterns of host use resulted from variation in factors such as host acceptance or variation in host suitability. Six species of aphids exposed to B. communis showed no signs of parasitism. Four of these species were not recognized as hosts and two effectively defended themselves from attack by B. communis. Other aphid species into which parasitoids laid eggs had low suitability as hosts. Parasitoid mortality occurred in the egg or early larval stages for some of these hosts but for others it occurred in late larval stages. Two hypotheses explaining low suitability were investigated in separate experiments: the presence of endosymbiotic bacteria conferring resistance to parasitoids, and aphids feeding on toxic plants. An association between resistance and endosymbiont infection was found in one species (Aphis craccivora), and evidence for the toxic plant hypothesis was found for the milkweed aphids Aphis asclepiadis and Aphis nerii. This research highlights the multifaceted nature of factors determining host specificity in parasitoids.}, }
@article {pmid19208259, year = {2009}, author = {Zhang, Y and Rodionov, DA and Gelfand, MS and Gladyshev, VN}, title = {Comparative genomic analyses of nickel, cobalt and vitamin B12 utilization.}, journal = {BMC genomics}, volume = {10}, number = {}, pages = {78}, pmid = {19208259}, issn = {1471-2164}, support = {R01 GM061603/GM/NIGMS NIH HHS/United States ; GM061603/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Cobalt/*metabolism ; *Comparative Genomic Hybridization ; Deltaproteobacteria/genetics/metabolism ; Evolution, Molecular ; Fungi/genetics/metabolism ; Methanosarcina/genetics/metabolism ; Molecular Sequence Data ; Multigene Family ; Nickel/*metabolism ; Phylogeny ; Plants/genetics/metabolism ; Sequence Alignment ; Vitamin B 12/*metabolism ; }, abstract = {BACKGROUND: Nickel (Ni) and cobalt (Co) are trace elements required for a variety of biological processes. Ni is directly coordinated by proteins, whereas Co is mainly used as a component of vitamin B12. Although a number of Ni and Co-dependent enzymes have been characterized, systematic evolutionary analyses of utilization of these metals are limited.<br><br>RESULTS: We carried out comparative genomic analyses to examine occurrence and evolutionary dynamics of the use of Ni and Co at the level of (i) transport systems, and (ii) metalloproteomes. Our data show that both metals are widely used in bacteria and archaea. Cbi/NikMNQO is the most common prokaryotic Ni/Co transporter, while Ni-dependent urease and Ni-Fe hydrogenase, and B12-dependent methionine synthase (MetH), ribonucleotide reductase and methylmalonyl-CoA mutase are the most widespread metalloproteins for Ni and Co, respectively. Occurrence of other metalloenzymes showed a mosaic distribution and a new B12-dependent protein family was predicted. Deltaproteobacteria and Methanosarcina generally have larger Ni- and Co-dependent proteomes. On the other hand, utilization of these two metals is limited in eukaryotes, and very few of these organisms utilize both of them. The Ni-utilizing eukaryotes are mostly fungi (except saccharomycotina) and plants, whereas most B12-utilizing organisms are animals. The NiCoT transporter family is the most widespread eukaryotic Ni transporter, and eukaryotic urease and MetH are the most common Ni- and B12-dependent enzymes, respectively. Finally, investigation of environmental and other conditions and identity of organisms that show dependence on Ni or Co revealed that host-associated organisms (particularly obligate intracellular parasites and endosymbionts) have a tendency for loss of Ni/Co utilization.<br><br>CONCLUSION: Our data provide information on the evolutionary dynamics of Ni and Co utilization and highlight widespread use of these metals in the three domains of life, yet only a limited number of user proteins.}, }
@article {pmid19206228, year = {2009}, author = {Zimmermann, K and Engeser, M and Blunt, JW and Munro, MH and Piel, J}, title = {Pederin-type pathways of uncultivated bacterial symbionts: analysis of o-methyltransferases and generation of a biosynthetic hybrid.}, journal = {Journal of the American Chemical Society}, volume = {131}, number = {8}, pages = {2780-2781}, doi = {10.1021/ja808889k}, pmid = {19206228}, issn = {1520-5126}, mesh = {Animals ; Leukemia P388/drug therapy ; Methyltransferases/chemistry/genetics/*metabolism ; Mice ; Nuclear Magnetic Resonance, Biomolecular ; Porifera/chemistry/metabolism ; Pseudomonas/genetics/*metabolism ; Pyrans/chemistry/*metabolism/pharmacology ; Symbiosis ; Tandem Mass Spectrometry ; }, abstract = {The complex polyketide pederin is a potent antitumor agent isolated from Paederus spp. rove beetles. We have previously isolated a set of genes from a bacterial endosymbiont that are good candidates for pederin biosynthesis. To biochemically study this pathway, we expressed three methyltransferases from the putative pederin pathway and used the partially unmethylated analogue mycalamide A from the marine sponge Mycale hentscheli as test substrate. Analysis by high-resolution MS/MS and NMR revealed that PedO regiospecifically methylates the marine compound to generate the nonnatural hybrid compound 18-O-methylmycalamide A with increased cytotoxicity. To our knowledge, this is the first biochemical evidence that invertebrates can obtain defensive complex polyketides from bacterial symbionts.}, }
@article {pmid19200360, year = {2009}, author = {de Souza, DJ and Bézier, A and Depoix, D and Drezen, JM and Lenoir, A}, title = {Blochmannia endosymbionts improve colony growth and immune defence in the ant Camponotus fellah.}, journal = {BMC microbiology}, volume = {9}, number = {}, pages = {29}, pmid = {19200360}, issn = {1471-2180}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Ants/*immunology/*microbiology/physiology ; DNA, Bacterial/genetics ; Enterobacteriaceae/drug effects/genetics/*physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: Microorganisms are a large and diverse form of life. Many of them live in association with large multicellular organisms, developing symbiotic relations with the host and some have even evolved to form obligate endosymbiosis. All Carpenter ants (genus Camponotus) studied hitherto harbour primary endosymbiotic bacteria of the Blochmannia genus. The role of these bacteria in ant nutrition has been demonstrated but the omnivorous diet of these ants lead us to hypothesize that the bacteria might provide additional advantages to their host. In this study, we establish links between Blochmannia, growth of starting new colonies and the host immune response.<br><br>RESULTS: We manipulated the number of bacterial endosymbionts in incipient laboratory-reared colonies of Camponotus fellah by administrating doses of an antibiotic (Rifampin) mixed in honey-solution. Efficiency of the treatment was estimated by quantitative polymerase chain reaction and Fluorescent in situ hybridization (FISH), using Blochmannia specific primers (qPCR) and two fluorescent probes (one for all Eubacterial and other specific for Blochmannia). Very few or no bacteria could be detected in treated ants. Incipient Rifampin treated colonies had significantly lower numbers of brood and adult workers than control colonies. The immune response of ants from control and treated colonies was estimated by inserting nylon filaments in the gaster and removing it after 24 h. In the control colonies, the encapsulation response was positively correlated to the bacterial amount, while no correlation was observed in treated colonies. Indeed, antibiotic treatment increased the encapsulation response of the workers, probably due to stress conditions.<br><br>CONCLUSION: The increased growth rate observed in non-treated colonies confirms the importance of Blochmannia in this phase of colony development. This would provide an important selective advantage during colony founding, where the colonies are faced with severe inter and intraspecific competition. Furthermore, the bacteria improve the workers encapsulation response. Thus, these ants are likely to be less susceptible to various pathogen attacks, such as the Phoridae fly parasitoids, normally found in the vicinity of Camponotus nests. These advantages might explain the remarkable ecological success of this ant genus, comprising more than 1000 species.}, }
@article {pmid19198544, year = {2008}, author = {Zhukova, MV and Voronin, DA and Kiseleva, EV}, title = {[High temperature initiates changes of Wolbachia ultrastructure in the ovaries and early embryos of Drosophila melanogaster].}, journal = {Tsitologiia}, volume = {50}, number = {12}, pages = {1050-1060}, pmid = {19198544}, issn = {0041-3771}, mesh = {Animals ; Drosophila melanogaster/embryology/*microbiology ; Embryo, Nonmammalian/*microbiology/ultrastructure ; Female ; Genome, Insect ; Hot Temperature ; Ovary/*microbiology/ultrastructure ; Symbiosis ; Wolbachia/physiology/*ultrastructure ; }, abstract = {Electron microscopic analysis of Drosophila melanogaster (w1118) ovarian cells has demonstrated that stressful heat treatment of flies results in the appearance of electron dense granules and large lysosomes in the cytoplasm of ovarian cells, which is not related with the presence of Wolbachia, as these changes are observed in both the infected and uninfected flies. High temperature initiates essential envelope defects and other structural changes of symbiotic bacteria in the cytoplasm of ovarian cells. Some embryos developing from eggs of heat shocked flies die, however, bacteria in the survival embryos retain their typical morphology. Endosymbionts do not change their localization and their contacts with the mitochondria and endoplasmic reticulum in the ovarian cells and early embryos after heat shock treatment of the flies. The results obtained show that high temperature influences on both the host and the endosymbiont, but does not change their structural mutual interactions.}, }
@article {pmid19192183, year = {2009}, author = {Ikeda-Ohtsubo, W and Brune, A}, title = {Cospeciation of termite gut flagellates and their bacterial endosymbionts: Trichonympha species and 'Candidatus Endomicrobium trichonymphae'.}, journal = {Molecular ecology}, volume = {18}, number = {2}, pages = {332-342}, doi = {10.1111/j.1365-294X.2008.04029.x}, pmid = {19192183}, issn = {1365-294X}, mesh = {Animals ; Bacteria/*classification/genetics ; Bayes Theorem ; Eukaryota/classification/*microbiology ; Evolution, Molecular ; Genes, rRNA ; *Genetic Speciation ; Isoptera/*microbiology ; Likelihood Functions ; Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal/genetics ; Sequence Alignment ; *Symbiosis ; }, abstract = {Symbiotic flagellates play a major role in the digestion of lignocellulose in the hindgut of lower termites. Many termite gut flagellates harbour a distinct lineage of bacterial endosymbionts, so-called Endomicrobia, which belong to the candidate phylum Termite Group 1. Using an rRNA-based approach, we investigated the phylogeny of Trichonympha, the predominant flagellates in a wide range of termite species, and of their Endomicrobia symbionts. We found that Trichonympha species constitute three well-supported clusters in the Parabasalia tree. Endomicrobia were detected only in the apical lineage (Cluster I), which comprises flagellates present in the termite families Termopsidae and Rhinotermitidae, but apparently absent in the basal lineages (Clusters II and III) consisting of flagellates from other termite families and from the wood-feeding cockroach, Cryptocercus punctulatus. The endosymbionts of Cluster I form a monophyletic group distinct from many other lineages of Endomicrobia and seem to have cospeciated with their flagellate host. The distribution pattern of the symbiotic pairs among different termite species indicates that cospeciation of flagellates and endosymbionts is not simply the result of a spatial separation of the flagellate lineages in different termite species, but that Endomicrobia are inherited among Trichonympha species by vertical transmission. We suggest extending the previously proposed candidatus name 'Endomicrobium trichonymphae' to all Endomicrobia symbionts of Trichonympha species, and estimate that the acquisition by an ancestor of Trichonympha Cluster I must have occurred about 40-70 million years ago, long after the flagellates entered the termites.}, }
@article {pmid19181828, year = {2009}, author = {Mouton, L and Henri, H and Fleury, F}, title = {Interactions between coexisting intracellular genomes: mitochondrial density and Wolbachia infection.}, journal = {Applied and environmental microbiology}, volume = {75}, number = {7}, pages = {1916-1921}, pmid = {19181828}, issn = {1098-5336}, mesh = {Animals ; Drosophila/*genetics/*microbiology ; *Host-Parasite Interactions ; Mitochondria/*genetics ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Many arthropods are infected with maternally transmitted microorganisms, leading to the coexistence of several intracellular genomes within the host cells, including their own mitochondria. As these genomes are cotransmitted, their patterns of evolution have been intimately linked, with possible consequences for the diversity and evolution of the host mitochondrial DNA. The evolutionary aspects of the situation have been thoroughly investigated, especially the selective sweep on the mitochondria as a result of Wolbachia invasion, whereas direct interactions between mitochondria and intracellular symbionts within the host cells or body have received little attention. Since endosymbionts exploit host resources but mitochondria supply energy to meet the bioenergetic demands of organisms, an unanswered question concerns the correlation between their densities. Here, we investigated the influence of Wolbachia symbiosis on mitochondrial density in two parasitic wasps of Drosophila species, both of which are naturally infected by three Wolbachia strains, but they differ in their degree of dependency on these bacteria. In Leptopilina heterotoma, all Wolbachia strains are facultative, whereas Asobara tabida requires a strain of Wolbachia for oogenesis to occur. In both species, Wolbachia infections are stable and well regulated, since the density of each strain does not depend on the presence or absence of other strains. Using lines that harbor various Wolbachia infection statuses, we found that mitochondrial density was not affected by the infection regardless of the sex and age of the host, which is strongly reminiscent of the independent regulation of specific Wolbachia strains and suggest that the protagonists coexist independently of each other as the result of a long-term coevolutionary interaction.}, }
@article {pmid21566374, year = {2009}, author = {Kikuchi, Y}, title = {Endosymbiotic bacteria in insects: their diversity and culturability.}, journal = {Microbes and environments}, volume = {24}, number = {3}, pages = {195-204}, doi = {10.1264/jsme2.me09140s}, pmid = {21566374}, issn = {1342-6311}, abstract = {Many animals and plants possess symbiotic microorganisms inside their body, wherein intimate interactions occur between the partners. The Insecta, often rated as the most diverse animal group, show various types of endosymbiotic associations, ranging from obligate mutualism to facultative parasitism. Although technological advancements in culture-independent molecular techniques, such as quantitative PCR, molecular phylogeny and in situ hybridization, as well as genomic and metagenomic analyses, have allowed us to directly observe endosymbiotic associations in vivo, the molecular mechanisms underlying insect-microbe interactions are not well understood, because most of these insect endosymbionts are neither culturable nor genetically manipulatable. However, recent studies have succeeded in the isolation of several facultative symbionts by using insect cell lines or axenic media, revolutionizing studies of insect endosymbiosis. This article reviews the amazing diversity of bacterial endosymbiosis in insects, focusing on several model systems with culturable endosymbionts, which provide a new perspective towards understanding how intimate symbiotic associations may have evolved and how they are maintained within insects.}, }
@article {pmid21564569, year = {2009}, author = {Mieog, JC and VAN Oppen, MJ and Berkelmans, R and Stam, WT and Olsen, JL}, title = {Quantification of algal endosymbionts (Symbiodinium) in coral tissue using real-time PCR.}, journal = {Molecular ecology resources}, volume = {9}, number = {1}, pages = {74-82}, doi = {10.1111/j.1755-0998.2008.02222.x}, pmid = {21564569}, issn = {1755-098X}, abstract = {Understanding the flexibility of the endosymbioses between scleractinian corals and single-cell algae of the genus Symbiodinium will provide valuable insights into the future of coral reefs. Here, a real-time polymerase chain reaction (PCR) assay is presented to accurately determine the cell densities of Symbiodinium clades C and D in the scleractinian coral Acropora millepora, which can be extended to other coral-symbiont associations in the future. The assay targets single- to low-copy genes of the actin family of both the coral host and algal symbiont. Symbiont densities are expressed as the ratio of Symbiodinium cells to each host cell (S/H ratio, error within 30%), but can also be normalized to coral surface area. Greater accuracy in estimating ratios of associations involving multiple clades is achieved compared with previous real-time PCR assays based on high-copy ribosomal DNA loci (error within an order of magnitude). Healthy adult A. millepora containing ~1.4 × 10(6) zooxanthellae per cm(2) (as determined by haemocytometer counts) had S/H ratios of c. 0.15, i.e. ~15 symbiont cells per 100 host cells. In severely bleached colonies, this ratio decreased to less than 0.005. Because of its capacity to accurately determine both densities and ratios of multiple symbionts within one sample, the assay will open the door for novel research into the mechanisms of symbiont shuffling and switching.}, }
@article {pmid21558694, year = {2008}, author = {Inoue, J and Noda, S and Hongoh, Y and Ui, S and Ohkuma, M}, title = {Identification of Endosymbiotic Methanogen and Ectosymbiotic Spirochetes of Gut Protists of the Termite Coptotermes formosanus.}, journal = {Microbes and environments}, volume = {23}, number = {1}, pages = {94-97}, doi = {10.1264/jsme2.23.94}, pmid = {21558694}, issn = {1342-6311}, abstract = {Prokaryotic associations with gut protists of the termite Coptotermes formosanus were investigated based on 16S rRNA gene sequences. An endosymbiotic methanogen of Spirotrichonympha leidyi phylogenetically grouped with endosymbionts of other gut protists in the genus Methanobrevibacter, seemed to be unrelated to the host protist phylogeny. Three different lineages of ectosymbiotic spirochetes in the genus Treponema were identified in single cells of Holomastigotoides mirabile, indicating their simultaneous occurrence. Although these symbionts represented mere minor populations in the gut, their phylogenetic assignments suggest a common symbiotic relationship involving H(2) metabolism.}, }
@article {pmid21558692, year = {2008}, author = {Aida, M and Kanemori, M and Kubota, N and Matada, M and Sasayama, Y and Fukumori, Y}, title = {Distribution and Population of Free-Living Cells Related to Endosymbiont A Harbored in Oligobrachia mashikoi (a Siboglinid Polychaete) Inhabiting Tsukumo Bay.}, journal = {Microbes and environments}, volume = {23}, number = {1}, pages = {81-88}, doi = {10.1264/jsme2.23.81}, pmid = {21558692}, issn = {1342-6311}, abstract = {Beard worms (Siboglinidae, Polychaeta), which lack a mouth and a digestive tract, harbor thioautotrophic or methanotrophic bacteria in special cells called bacteriocytes. These endosymbionts have been considered to be trapped at a specific larval stage from the environment. Although many species of beard worms have been discovered in various abyssal seas, Oligobrachia mashikoi inhabits Tsukumo Bay which is only 25 m deep. At least seven types of endosymbionts (endosymbiont A-G) have been distinguished in O. mashikoi. In this study, we investigated the distribution pattern of free-living cells related to the major endosymbiont (endosymbiont A) in Tsukumo Bay by quantitative PCR targeting the 16S rRNA gene. The endosymbiont A-related phylotype was detected in almost all sediment samples collected from 23 points in Tsukumo Bay, ranging in copy number of the 16S rRNA gene from 2.22×10(4) to 1.42×10(6) copies per gram of dry-sediment. Furthermore, the free-living cells made up less than 9% of the total eubacterial population, suggesting that the O. mashikoi larvae precisely select candidates for their endosymbiont from bacterial flora in the environment. This is the first report on the ecological characterization of a free-living bacterium related to the endosymbiont of the siboglinid polychaete, O. mashikoi.}, }
@article {pmid19425156, year = {2008}, author = {Moustafa, A and Chan, CX and Danforth, M and Zear, D and Ahmed, H and Jadhav, N and Savage, T and Bhattacharya, D}, title = {A phylogenomic approach for studying plastid endosymbiosis.}, journal = {Genome informatics. International Conference on Genome Informatics}, volume = {21}, number = {}, pages = {165-176}, pmid = {19425156}, issn = {0919-9454}, support = {R01ES013679/ES/NIEHS NIH HHS/United States ; }, mesh = {Bacteria/classification/genetics ; Diatoms/genetics ; Enzymes/genetics ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Genome ; Genome, Bacterial ; Genome, Plant ; *Models, Genetic ; Multigene Family ; *Phylogeny ; Plants/genetics ; Plastids/*genetics ; Rhodophyta/classification/*genetics ; Software ; Symbiosis/*genetics ; }, abstract = {Gene transfer is a major contributing factor to functional innovation in genomes. Endosymbiotic gene transfer (EGT) is a specific instance of lateral gene transfer (LGT) in which genetic materials are acquired by the host genome from an endosymbiont that has been engulfed and retained in the cytoplasm. Here we present a comprehensive approach for detecting gene transfer within a phylogenetic framework. We applied the approach to examine EGT of red algal genes into Thalassiosira pseudonana, a free-living diatom for which a complete genome sequence has recently been determined. Out of 11,390 predicted protein-coding sequences from the genome of T. pseudonana, 124 (1.1%, clustered into 80 gene families) are inferred to be of red algal origin (bootstrap support >or= 75%). Of these 80 gene families, 22 (27.5%) encode novel, unknown functions. We found 21.3% of the gene families to putatively encode non-plastid-targeted proteins. Our results suggest that EGT of red algal genes provides a relatively minor contribution to the nuclear genome of the diatom, but the transferred genes have functions that extend beyond photosynthesis. This assertion awaits experimental validation. Whereas the current study is focused within the context of secondary endosymbiosis, our approach can be applied to large-scale detection of gene transfer in any system.}, }
@article {pmid19704752, year = {2007}, author = {Richards, TA and Talbot, NJ}, title = {Plant parasitic oomycetes such as phytophthora species contain genes derived from three eukaryotic lineages.}, journal = {Plant signaling &amp; behavior}, volume = {2}, number = {2}, pages = {112-114}, pmid = {19704752}, issn = {1559-2316}, abstract = {Fungi and the oomycetes include several groups of plant pathogenic microbes. Although these two eukaryotic groups are unrelated they have a number of phenotypic similarities suggested to have evolved convergently. We have recently shown that gene transfer events have occurred from fungi to the oomycetes. These gene transfer events appear to be only one part of a complex and chimeric ancestry for the oomycete genome, which has also received genes from a red algal endosymbiont.}, }
@article {pmid20331397, year = {2007}, author = {Mattila, JT and Munderloh, UG and Kurtti, TJ}, title = {Phagocytosis of the Lyme disease spirochete, Borrelia burgdorferi, by cells from the ticks, Ixodes scapularis and Dermacentor andersoni, infected with an endosymbiont, Rickettsia peacockii.}, journal = {Journal of insect science (Online)}, volume = {7}, number = {}, pages = {58}, pmid = {20331397}, issn = {1536-2442}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; 5R01 AI049424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Borrelia burgdorferi/metabolism/*physiology ; Cell Line ; Cytochalasin B/pharmacology ; Dermacentor/cytology/*metabolism/*microbiology ; Green Fluorescent Proteins/metabolism ; Ixodes/cytology/*metabolism/*microbiology ; *Phagocytosis/drug effects ; Rickettsia/*physiology ; Symbiosis ; }, abstract = {Tick cell lines were used to model the effects of endosymbiont infection on phagocytic immune responses. The lines tested for their ability to phagocytose the Lyme disease spirochete, Borrelia burgdorferi (Spirochaetales: Spirochaetaceae), were ISE6 and IDE12 from the black-legged tick, Ixodes scapularis Say (Acari: Ixodidae) and DAE15 from the Rocky Mountain wood tick, Dermacentor andersoni Stiles. Rickettsia peacockii (Rickettsiales: Rickettsiaceae), an endosymbiont of D. andersoni, was used as a representative tick endosymbiont. 70-80% of uninfected or R. peacocciz-infected IDE12 and DAE15 cells phagocytosed heat-killed borreliae and 80-90% of IDE12 and DAE15 cells phagocytosed viable spirochetes. ISE6 cells were permissive of spirochetes; less than 1% of these cells phagocytosed borreliae, and spirochetes remained adherent to the cells seven days after inoculation. Cytochalasin B blocked phagocytosis of killed and viable borreliae by IDE12 cells, and prevented phagocytosis of killed spirochetes by DAE15 cells, whereas viable spirochetes successfully invaded cytochalasin-treated DAE15. IDE12 and DAE15 cells degraded borreliae within phagolysosome-like compartments. Time-lapse microscopy showed that DAE15 cells phagocytosed borreliae more rapidly than IDE12 cells. IDE12 and DAE15 cells eliminated most adherent spirochetes within 7 days of inoculation. Thus, endosymbiont infection does not significantly interfere with the phagocytic activity of immunocompetent tick cells.}, }
@article {pmid20302539, year = {2007}, author = {Gray, SM and Caillaud, MC and Burrows, M and Smith, DM}, title = {Transmission of two viruses that cause Barley Yellow Dwarf is controlled by different loci in the aphid, Schizaphis graminum.}, journal = {Journal of insect science (Online)}, volume = {7}, number = {}, pages = {1-15}, pmid = {20302539}, issn = {1536-2442}, mesh = {Animals ; Aphids/*genetics/*virology ; Female ; Genetic Loci/genetics ; Genotype ; Luteovirus/*physiology ; Male ; Triticum/*virology ; }, abstract = {Clonal populations of the aphid, Schizaphis graminum, have been separated into biotypes based on host preference and their ability to overcome resistance genes in wheat. Recently, several biotypes were found to differ in their ability to transmit one or more of the viruses that cause barley yellow dwarf disease in grain crops, and vector competence was linked to host preference. The genetics of host preference has been studied in S. graminum, but how this may relate to the transmission of plant viruses is unknown. Sexual morphs of a vector and nonvector S. graminum genotype were induced from parthenogenetic females and reciprocal crosses made. Eighty-nine hybrids were generated and maintained by parthenogenesis. Each hybrid was evaluated for its ability to transmit Barley yellow dwarf virus-PAV and Cereal yellow dwarf virus-RPV, and for its ability to colonize two wheat genotypes each expressing a different gene that confers resistance to S. graminum. The F1 genotypes were genetically variable for their ability to transmit virus and to colonize the aphid resistant wheat, but these traits were not genetically correlated. Individual F1 genotypes ranged in transmission efficiency from 0-100% for both viruses, although the overall mean transmission efficiency was similar to the transmission competent parent, indicating directional dominance. The direction of the cross did not significantly affect the vector competency for either virus, suggesting that maternally inherited cytoplasmic factors, or bacterial endosymbionts, did not contribute significantly to the inheritance of vector competency in S. graminum. Importantly, there was no genetic correlation between the ability to transmit Barley yellow dwarf virus and Cereal yellow dwarf virus-RPV in the F1 genotypes. These results taken together indicate that multiple loci are involved in the circulative transmission, and that the successful transmission of these closely related viruses is regulated by different sets of aphid genes.}, }
@article {pmid19455199, year = {2007}, author = {Neumann, N and Jeffares, DC and Poole, AM}, title = {Outsourcing the nucleus: nuclear pore complex genes are no longer encoded in nucleomorph genomes.}, journal = {Evolutionary bioinformatics online}, volume = {2}, number = {}, pages = {23-34}, pmid = {19455199}, issn = {1176-9343}, abstract = {The nuclear pore complex (NPC) facilitates transport between nucleus and cytoplasm. The protein constituents of the NPC, termed nucleoporins (Nups), are conserved across a wide diversity of eukaryotes. In apparent exception to this, no nucleoporin genes have been identified in nucleomorph genomes. Nucleomorphs, nuclear remnants of once free-living eukaryotes, took up residence as secondary endosymbionts in cryptomonad and chlorarachniophyte algae. As these genomes are highly reduced, Nup genes may have been lost, or relocated to the host nucleus. However, Nup genes are often poorly conserved between species, so absence may be an artifact of low sequence similarity. We therefore constructed an evolutionary bioinformatic screen to establish whether the apparent absence of Nup genes in nucleomorph genomes is due to genuine absence or the inability of current methods to detect homologues. We searched green plant (Arabidopsis and rice), green alga (Chlamydomonas reinhardtii) and red alga (Cyanidioschyzon merolae) genomes, plus two nucleomorph genomes (Bigelowiella natans and Guillardia theta) with profile hidden Markov models (HMMs) from curated alignments of known vertebrate/yeast Nups. Since the plant, algal and nucleomorph genomes all belong to the kingdom Plantae, and are evolutionarily distant from the outgroup (vertebrate/yeast) training set, we use the plant and algal genomes as internal positive controls for the sensitivity of the searches in nucleomorph genomes. We find numerous Nup homologues in all plant and free-living algal species, but none in either nucleomorph genome. BLAST searches using identified plant and algal Nups also failed to detect nucleomorph homologues. We conclude that nucleomorph Nup genes have either been lost, being replaced by host Nup genes, or, that nucleomorph Nup genes have been transferred to the host nucleus twice independently; once in the evolution of the red algal nucleomorph and once in the green algal nucleomorph.}, }
@article {pmid21676806, year = {2005}, author = {Furla, P and Allemand, D and Shick, JM and Ferrier-Pagès, C and Richier, S and Plantivaux, A and Merle, PL and Tambutté, S}, title = {The Symbiotic Anthozoan: A Physiological Chimera between Alga and Animal.}, journal = {Integrative and comparative biology}, volume = {45}, number = {4}, pages = {595-604}, doi = {10.1093/icb/45.4.595}, pmid = {21676806}, issn = {1540-7063}, abstract = {The symbiotic life style involves mutual ecological, physiological, structural, and molecular adaptations between the partners. In the symbiotic association between anthozoans and photosynthetic dinoflagellates (Symbiodinium spp., also called zooxanthellae), the presence of the endosymbiont in the animal cells has constrained the host in several ways. It adopts behaviors that optimize photosynthesis of the zooxanthellae. The animal partner has had to evolve the ability to absorb and concentrate dissolved inorganic carbon from seawater in order to supply the symbiont's photosynthesis. Exposing itself to sunlight to illuminate its symbionts sufficiently also subjects the host to damaging solar ultraviolet radiation. Protection against this is provided by biochemical sunscreens, including mycosporine-like amino acids, themselves produced by the symbiont and translocated to the host. Moreover, to protect itself against oxygen produced during algal photosynthesis, the cnidarian host has developed certain antioxidant defenses that are unique among animals. Finally, living in nutrient-poor waters, the animal partner has developed several mechanisms for nitrogen assimilation and conservation such as the ability to absorb inorganic nitrogen, highly unusual for a metazoan. These facts suggest a parallel evolution of symbiotic cnidarians and plants, in which the animal host has adopted characteristics usually associated with phototrophic organisms.}, }
@article {pmid20565652, year = {2005}, author = {Kang, M and Dunigan, DD and VAN Etten, JL}, title = {Chlorovirus: a genus of Phycodnaviridae that infects certain chlorella-like green algae.}, journal = {Molecular plant pathology}, volume = {6}, number = {3}, pages = {213-224}, doi = {10.1111/j.1364-3703.2005.00281.x}, pmid = {20565652}, issn = {1364-3703}, abstract = {SUMMARY Taxonomy: Chlorella viruses are assigned to the family Phycodnaviridae, genus Chlorovirus, and are divided into three species: Chlorella NC64A viruses, Chlorella Pbi viruses and Hydra viridis Chlorella viruses. Chlorella viruses are large, icosahedral, plaque-forming, dsDNA viruses that infect certain unicellular, chlorella-like green algae. The type member is Paramecium bursaria chlorella virus 1 (PBCV-1). Physical properties: Chlorella virus particles are large (molecular weight approximately 1 x 10(9) Da) and complex. The virion of PBCV-1 contains more than 100 different proteins; the major capsid protein, Vp54, comprises approximately 40% of the virus protein. Cryoelectron microscopy and three-dimensional image reconstruction of PBCV-1 virions indicate that the outer glycoprotein-containing capsid shell is icosahedral and surrounds a lipid bilayered membrane. The diameter of the viral capsid ranges from 1650 A along the two- and three-fold axes to 1900 A along the five-fold axis. The virus contains 5040 copies of Vp54, and the triangulation number is 169. The PBCV-1 genome is a linear, 330 744-bp, non-permuted dsDNA with covalently closed hairpin ends. The PBCV-1 genome contains approximately 375 protein-encoding genes and 11 tRNA genes. About 50% of the protein-encoding genes match proteins in the databases. Hosts: Chlorella NC64A and Chlorella Pbi, the hosts for NC64A viruses and Pbi viruses, respectively, are endosymbionts of the protozoan Paramecium bursaria. However, they can be grown in the laboratory free of both the paramecium and the virus. These two chlorella species are hosts to viruses that have been isolated from fresh water collected around the world. The host for hydra chlorella virus, a symbiotic chlorella from Hydra viridis, has not been grown independently of its host; thus the virus can only be obtained from chlorella cells freshly released from hydra.}, }
@article {pmid21676782, year = {2005}, author = {Thacker, RW}, title = {Impacts of Shading on Sponge-Cyanobacteria Symbioses: A Comparison between Host-Specific and Generalist Associations.}, journal = {Integrative and comparative biology}, volume = {45}, number = {2}, pages = {369-376}, doi = {10.1093/icb/45.2.369}, pmid = {21676782}, issn = {1540-7063}, abstract = {The marine sponge Lamellodysidea chlorea contains large populations of the host-specific, filamentous cyanobacterium Oscillatoria spongeliae. Other marine sponges, including Xestospongia exigua, contain the generalist, unicellular cyanobacterium Synechococcus spongiarum. The impact of cyanobacterial photosynthesis on host sponges was manipulated by shading these sponge-cyanobacteria associations. If cyanobacteria benefit their hosts, shading should reduce this benefit. Chlorophyll a concentrations were measured as an index of cyanobacterial abundance. After two weeks, shaded L. chlorea lost more mass than controls, while shaded and control X. exigua did not lose a significant amount of mass. Chlorophyll a concentrations in shaded X. exigua were lower than in controls, but were not significantly different between shaded and control L. chlorea. In addition, L. chlorea shaded in situ lost over 40% of their initial area, but did not differ in chlorophyll a concentrations from controls. These results suggest that Oscillatoria symbionts benefit their host sponges in a mutualistic association. Synechococcus symbionts may be commensals that exploit the resources provided by their sponge hosts without significantly affecting sponge mass. When shaded, Synechococcus symbionts may be consumed by their hosts or may be able to disperse from this unfavorable environment. These data support the hypothesis that more specialized symbionts provide a greater benefit to their hosts, but hypotheses concerning the dispersal abilities of these symbionts remain to be explored. Sponge-cyanobacteria symbioses provide model systems for investigating the costs and benefits of symbiosis and the roles of dispersal, environmental conditions, and phylogenetic history in determining the specificity of endosymbionts for their hosts.}, }
@article {pmid19712370, year = {2004}, author = {Selvin, J and Joseph, S and Asha, KR and Manjusha, WA and Sangeetha, VS and Jayaseema, DM and Antony, MC and Denslin Vinitha, AJ}, title = {Antibacterial potential of antagonistic Streptomyces sp. isolated from marine sponge Dendrilla nigra.}, journal = {FEMS microbiology ecology}, volume = {50}, number = {2}, pages = {117-122}, doi = {10.1016/j.femsec.2004.06.007}, pmid = {19712370}, issn = {1574-6941}, mesh = {Animals ; Anti-Bacterial Agents/*biosynthesis ; *Antibiosis ; Culture Media/chemistry ; Microbial Sensitivity Tests ; Microbial Viability ; Micrococcus luteus/drug effects/growth &amp; development ; Porifera/*microbiology ; Streptomyces/*isolation &amp; purification/*physiology ; }, abstract = {The role of Streptomyces sp. (BTL7) in synthesis of antibacterial agents reported from the marine sponge Dendrilla nigra was evaluated. Selective isolation of actinomycetes was performed on the newly developed selective media, Sponge Agar (SA) 1 and SA 2. The growth rate and antibiotic production were increased on the media supplemented with sponge extract. The chosen isolate BTL7 showed inhibitory interaction with Micrococcus luteus and the extracellular products contained potent antibacterial agents. The minimum inhibitory concentration of BTL7 against M. luteus was 44 microg protein/ml and the minimum bactericidal concentration was 88 microg protein/ml. Peak antibacterial activity was observed at 72 h in batch culture. Based on the findings, it could be inferred that bacterial endosymbionts sponges could form a reliable source for bioprospecting of next generation pharmaceutical agents.}, }
@article {pmid21148896, year = {2004}, author = {Suh, SO and White, MM and Nguyen, NH and Blackwell, M}, title = {The status and characterization of Enteroramus dimorphus: a xylose-fermenting yeast attached to the gut of beetles.}, journal = {Mycologia}, volume = {96}, number = {4}, pages = {756-760}, doi = {10.1080/15572536.2005.11832923}, pmid = {21148896}, issn = {0027-5514}, abstract = {Enteroramus dimorphus from the gut of the passalid beetle Odontotaenius disjunctus was described originally as a yeast-like fungus of unknown taxonomic affiliation. The fungus can be observed in situ, attached by a specialized cell to the beetle hindgut wall. In a recent study of yeast endosymbionts from a variety of beetles, we discovered that E. dimorphus is a member of the Pichia stipitis (Saccharomycetes) clade, known for xylose fermentation and assimilation. The closest relative of E. dimorphus is the PASS1 isolate, repeatedly acquired from passalid beetles in eastern North America from Pennsylvania to Louisiana. In addition to xylose fermentation and assimilation, these yeasts are characterized by the production of hat-shaped ascospores in culture, assimilation of a wide range of sugars, and synthesis of several vitamins. Enteroramus dimorphus, however, can be distinguished from close relatives by several physiological characteristics and rDNA sequences, which vary slightly from the more widespread PASS1 genotype. We present an amended description of E. dimorphus and discuss its symbiotic phase in association with O. disjunctus, including a holdfast that parallels those of unrelated symbiotic yeasts associated with nematodes.}, }
@article {pmid19262760, year = {2003}, author = {Bordenstein, SR and Fitch, DH and Werren, JH}, title = {Absence of wolbachia in nonfilariid nematodes.}, journal = {Journal of nematology}, volume = {35}, number = {3}, pages = {266-270}, pmid = {19262760}, issn = {0022-300X}, abstract = {Intracellular bacteria of the genus Wolbachia are among the most abundant endosymbionts on the planet, occurring in at least two major phyla-the Arthropoda and Nematoda. Current surveys of Wolbachia distribution have found contrasting patterns within these groups. Whereas Wolbachia are widespread and occur in all three major subphyla of arthropods, with estimates placing them in at least several million arthropod species, the presence of nematodes carrying Wolbachia is currently confined to the filariids, in which they occur at appreciable frequencies. It has been hypothesized that Wolbachia entered the ancestor of modern-day filariids in a single acquisition event, and subsequently cospeciated with their filariid hosts. To further investigate this hypothesis, we examined the broader distribution of Wolbachia in nematodes using a polymerase chain reaction (PCR) assay in a diverse set of nonfilariid species. The assay consisted of three different types of PCR screens on adults of 20 secernentean nematode species (14 rhabditids, 2 strongylid parasites of vertebrates; 1 diplogasterid; 3 cephalobid relatives, 1 myolaim, and 1 filariid) and two adenophorean species (plectids). Two PCR screens were specific to the 16S rDNA and ftsZ protein coding gene of Wolbachia; and the third screen was specific to the 18S rDNA of the nematodes. Based upon our results, we conclude that Wolbachia are absent in all 21 non-filariid species encompassing all the major groups of the Secernentea and two species of Adenophorea, from which the Secernentea derived. The absence of Wolbachia in these non-filariids is consistent with the hypothesis that Wolbachia entered the nematode phylum once, in an ancestral lineage of extant filariids.}, }
@article {pmid21680407, year = {2003}, author = {Dewel, RA and Connell, MU and Dewel, WC}, title = {Bridging morphological transitions to the metazoa.}, journal = {Integrative and comparative biology}, volume = {43}, number = {1}, pages = {28-46}, doi = {10.1093/icb/43.1.28}, pmid = {21680407}, issn = {1540-7063}, abstract = {Our inability to answer many questions regarding the development of metazoan complexity may be due in part to the prevailing idea that most eukaryote "phyla" originated within a short period of geologic time from simple unicellular ancestors. This view, however, is contradicted by evidence that larger groups of eukaryotes share characters, suggesting that these assemblages inherited characters from a common ancestor. Because molecular analyses have had limited success in resolving the relationships of higher eukaryote taxa, we have undertaken a phylogenetic analysis based primarily on morphological characters. The analysis emphasizes characters considered to have a high probability of having evolved only once. Transitions between taxa are evaluated for the likelihood of character-state transformations. The analysis indicates that the evolutionary history of the clade containing the Metazoa has been complex, encompassing the gain and loss of a secondary and perhaps a primary photosynthetic endosymbiont with accompanying changes in trophic level. The history also appears to have included a hetero-autotrophic ancestor that possessed a "conoid" feeding apparatus and may have involved a transformation from a flagellate to an amoeboid body form, a trend toward increased intracellular compartmentation, and the development of complex social behavior. Such changes could have been critical for establishing the underlying complexity required for a rapid diversification of cell and tissue types in the early stages of metazoan evolution.}, }
@article {pmid23194718, year = {1998}, author = {Edgcomb, V and Viscogliosi, E and Simpson, AG and Delgado-Viscogliosi, P and Roger, AJ and Sogin, ML}, title = {New Insights into the Phylogeny of Trichomonads Inferred from Small Subunit rRNA Sequences.}, journal = {Protist}, volume = {149}, number = {4}, pages = {359-366}, doi = {10.1016/S1434-4610(98)70042-2}, pmid = {23194718}, issn = {1434-4610}, abstract = {Small subunit ribosomal DNA sequences were obtained by polymerase chain reaction from four trichomonad species: a frog endosymbiont Trichomitus batrachorum, an intestinal endosymbiont of a squamate reptile, Hypotrichomonas acosta and two free-living isolates, Monotrichomonas carabina and Monotrichomonas sp. Molecular trees inferred by distance, parsimony and likelihood techniques identify three well-resolved clusters within the trichomonads, however bootstrap values do not strongly support a particular branching order for these lineages. The first cluster includes the Devescovinidae and the Calonymphidae. The second clade unites Trichomitus batrachorum and Hypotrichomonas acosta. The third cluster embraces all known free-living genera, including Monotrichomonas, and various members of the Trichomonadinae subfamily such as Trichomonas vaginalis, and Pentatrichomonoides scroa. Neither Monocercomonadidae nor the Trichomonadidae as envisaged are monophyletic. Most of the monocercomonads, which possess a rudimentary cytoskeleton, were likely descendants of more complex forms. The study also suggests that the genus Trichomitus is currently polyphyletic, partly explaining the discordant positions of this genus in previous molecular analyses.}, }
@article {pmid21238234, year = {1998}, author = {Sues, HD and Reisz, RR}, title = {Origins and early evolution of herbivory in tetrapods.}, journal = {Trends in ecology &amp; evolution}, volume = {13}, number = {4}, pages = {141-145}, doi = {10.1016/s0169-5347(97)01257-3}, pmid = {21238234}, issn = {0169-5347}, abstract = {The first herbivorous tetrapods date from the Late Carboniferous, about 300 million years ago. By the Late Permian, continental ecosystems of `modern' aspect had been established, with a vast standing crop of herbivores supporting relatively few carnivores. Processing of high-fibre plant material requires (1) structural modifications of the dentition, jaw apparatus and digestive tract and (2) the acquisition of microbial endosymbionts that produce the enzymes needed for fermentative digestion of cellulose, the principal compound of cell walls in plants. Recent phylogenetic analyses of tetrapods indicate that endosymbiotic cellulysis was acquired independently in a number of lineages during the late Palaeozoic.}, }
@article {pmid21236874, year = {1994}, author = {Brul, S and Stumm, CK}, title = {Symbionts and organelles in ancrobic protozoa and fungi.}, journal = {Trends in ecology &amp; evolution}, volume = {9}, number = {9}, pages = {319-324}, doi = {10.1016/0169-5347(94)90151-1}, pmid = {21236874}, issn = {0169-5347}, abstract = {The discovery of methanogenic bacteria as endosymbionts of free-living anaerobic protozoa opened new fields of research in microbial ecology, cell physiology and molecular biology. Recent information from 16S rRNA sequence studies has shown in three cases that endosymbiotic methanogenic bacteria differ from free-living species. Frequently, endosymbiotic methanogens are localized in anaerobic protozoa near hydrogenosomes - organelles that produce H2, C02 and acetate, all of which are substrates for methanogenesis. Hydrogenosomes are also present in anaerobic fungi. The current view is that the organelles are endosymbllont-derived and were probably acquired on several distinct occasions during evolution.}, }
@article {pmid21236755, year = {1994}, author = {Moran, N and Baumann, P}, title = {Phylogenetics of cytoplasmically inherited microorganisms of arthropods.}, journal = {Trends in ecology &amp; evolution}, volume = {9}, number = {1}, pages = {15-20}, doi = {10.1016/0169-5347(94)90226-7}, pmid = {21236755}, issn = {0169-5347}, abstract = {Associations with cytoplasmically inherited microorganisms are fundamental to the ecology and reproductive biology of many insects. Molecular phylogenetics now provides a window into the previously obscure history of these associations. This approach has recently yielded striking findings for two cases: the mutualistic endosymbionts of aphids and relatives, and some of the cytoplasmically inherited organisms that induce reproductive abnormalities in various arthropods. These examples provide useful reference points for future extensions of molecular phylogenetic methods to other prokaryote-eukaryote associations.}, }
@article {pmid23195535, year = {1993}, author = {Sitte, P}, title = {Symbiogenetic evolution of complex cells and complex plastids.}, journal = {European journal of protistology}, volume = {29}, number = {2}, pages = {131-143}, doi = {10.1016/S0932-4739(11)80266-X}, pmid = {23195535}, issn = {0932-4739}, abstract = {It is generally accepted today that mitochondria and plastids of eukaryotic cells ("eucytes") have their phylogenetic origins in prokaryotic cells ("protocytes") that had been taken up into urkaryotic host cells as intracellular symbionts. This concept, strongly supported (among other evidence) by comparisons of rRNA and protein sequence data, has many important consequences for understanding both cellular evolution and cellular compartmentation. According to the Serial Endosymbiont Theory (SET), the eucyte came about by the formation of stable intracellular symbioses of quite different cells. The formation of such symbioses is referred to here as intertaxonic combination (ITC). In addition to mutation and genetic recombination, ITC emerges as a third progressive power in evolution. The situation can be complicated by repeated ITC. This is discussed in detail by taking the evolution of complex plastids as an example. Plastids of this kind, possessing 3 or 4 enveloping membranes instead of 2, are widespread in algae. They appear to be remnants of eukaryotic, and phototrophic, endocytobionts in phagotrophic host cells. The phylogeny of complex plastids could recently be fully reconstructed in the case of cryptomonads, and partly also in the case of Chlorarachnion.}, }
@article {pmid23195450, year = {1993}, author = {Broers, CA and Meijers, HH and Symens, JC and Stumm, CK and Vogels, GD and Brugerolle, G}, title = {Symbiotic association of Psalteriomonas vulgaris n. spec. with Methanobacterium formicicum.}, journal = {European journal of protistology}, volume = {29}, number = {1}, pages = {98-105}, doi = {10.1016/S0932-4739(11)80302-0}, pmid = {23195450}, issn = {0932-4739}, abstract = {The free-living anaerobic flagellate Psalteriomonas vulgaris n. spec. is described. The organism has four flagella of equal length which arise immediately subapically to the anterior part of the cell, within the apex of the ventral groove. The ultrastructural organization of the mastigont system and the ventral groove show the characteristics of the genus Psalteriomonas. The cells harboured methanogenic endosymbionts which were associated with hydrogenosome-like organelles in which hydrogenase could be localized. The methanogenic bacteria were isolated and identified as Methanobacterium formicicum. After addition of 5% O(2) to the cultures, the cells lost the methanogenic endosymbionts. P. vulgaris lacked cytochrome oxidase and catalase but contained superoxide dismutase.}, }
@article {pmid23195097, year = {1992}, author = {Finlay, BJ and Fenchel, T}, title = {An anaerobic ciliate as a natural chemostat for the growth of endosymbiotic methanogens.}, journal = {European journal of protistology}, volume = {28}, number = {2}, pages = {127-137}, doi = {10.1016/S0932-4739(11)80041-6}, pmid = {23195097}, issn = {0932-4739}, abstract = {An anaerobic ciliate (Metopus palaeformis) with methanogen endosymbionts was grown in batch culture. The growth of both partners was monitored for four ciliate generations following re-feeding. Methanogens consistently accounted for approximately 1% of total consortium biovolume. Minor variations in ciliate and methanogen biovolume were closely correlated. Methanogens completed one to two generations per ciliate generation. The growth of methanogens in these ciliates is analogous to the growth of microbes in a chemostat, with methanogen growth rate rapidly converging on a rate that is equal to the 'dilution rate' provided by the expanding ciliate cell volume. Methanogen digestion was insignificant in growing ciliates and no other loss processes were recognised. We conclude that the growth rates of ciliates and methanogens are approximately equivalent. The only exception occurs in ciliates showing no net growth, when substrate supply within the ciliate is still sufficient to promote measurable growth of methanogens. The methanogens within each ciliate appear to divide simultaneously and irrespective of their size. This phenomenon is not apparently integrated with events in the host cell cycle. It may give the methanogens some selective advantage in securing their persistence in successive ciliate generations.}, }
@article {pmid23194703, year = {1991}, author = {Fujishima, M and Nagahara, K and Kojima, Y and Sayama, Y}, title = {Sensitivity of the infectious long form of the macronuclear endosymbiont Holospora obtusa of the ciliate Paramecium caudatum against chemical and physical factors.}, journal = {European journal of protistology}, volume = {27}, number = {2}, pages = {119-126}, doi = {10.1016/S0932-4739(11)80333-0}, pmid = {23194703}, issn = {0932-4739}, abstract = {Effects of various temperatures, pHs and drugs on the morphology, infectivity to the macronucleus of Paramecium caudatum (ability to penetrate macronuclear membrane), and reproductive ability of the infectious long form of Holospora obtusa were examined. The infectivity was not lost between pH 3-12, suggesting that acidosomal fusion with the bacteria-bearing food vacuoles does not inactivate the bacterial infectivity because pH in the food vacuoles at the maximum acidification has been known to be 3. However, bacteria treated with 220 μg/ml α-mannosidase could not infect the macronucleus though they could invade the host cytoplasm, via food vacuoles. This indicates that the bacteria have to escape from the food vacuole and invade the host cytoplasm within 8 min after being engulfed into the food vacuoles for successful infection, because it is known that the lysosomal fusion occurs at 8 min and a-mannosidase activity has been detected in P. caudatum. Other glycoside hydrolases and proteases examined did not affect the bacteria. The bacteria could be kept at -85°C for 6 months without any damage, but they easily lost the infectivity at temperatures higher than 30°C. Treatments with 250 units/ml penicillin and 0.25 % (w/v) kanamycin for 1 week at 25°C did not affect the bacteria, suggesting that the infectious long form is metabolically inactive. The bacteria became cell-wall ghosts in 50 % (w/v) acetic acid and soon lysed in 0.5 N NaOH, but hardly lysed in various detergents used.}, }
@article {pmid23196051, year = {1990}, author = {Broers, CA and Stumm, CK and Vogels, GD and Brugerolle, G}, title = {Psalteriomonas lanterna gen. nov., sp. nov., a free-living amoeboflagellate isolated from freshwater anaerobic sediments.}, journal = {European journal of protistology}, volume = {25}, number = {4}, pages = {369-380}, doi = {10.1016/S0932-4739(11)80130-6}, pmid = {23196051}, issn = {0932-4739}, abstract = {A novel amoeboflagellate, isolated from anoxic sediment samples, is described and named Psalteriomonas lanterna gen. nov., sp. nov. The cells of the flagellate stage show a fourfold rotational symmetry with four nuclei, four ventral grooves and four mastigont systems. Each mastigont has four flagella of equal length. Microtubular roots, striated roots or rhizoplasts and electron-dense structures are associated with their basal bodies. A Golgi apparatus is absent. Organelles surrounded by rough endoplasmic reticulum (RER) are presumably modified mitochondria. Methanogenic endosymbiotic bacteria are closely associated with microbodies and form a central body. Nuclear division shows the characteristics of a closed mitosis. Cells of the amoeboid stage are mononucleated and lack the methanogenic endosymbionts. Reproduction occurs in both stages of the life cycle.}, }
@article {pmid23195469, year = {1988}, author = {Meier, R and Wiessner, W}, title = {Infection of algae-free Paramecium bursaria with symbiotic Chlorella sp. Isolated from green paramecia: I. Effect of the incubation period.}, journal = {European journal of protistology}, volume = {24}, number = {1}, pages = {69-74}, doi = {10.1016/S0932-4739(88)80011-7}, pmid = {23195469}, issn = {0932-4739}, abstract = {The significance of the length of incubation (30 sec to 48 h) of algae-free Paramecium bursaria with symbiotic Chlorella sp. for the success of infection, i.e. the reestablishment of the endosymbiotic algae has been investigated. When algae are brought together with paramecia, they are rapidly taken up by the ciliates. During a 30 sec incubation one ciliate engulfs about 50 chlorellae. A prolongation of the incubation period increases the number of ingested algae. However, the success of infection, determined one and five day(s) after the end of the incubation, is independent from the length of the incubation period and, consequently, does not depend on the number of ingested algae, either: In all experiments about 50% of the Paramecium population becomes infected and one to three algae are primarily enclosed in individual perialgal vacuoles within a ciliate cell. Thus, the endosymbiont population of a Paramecium cell originates on an average from two algae. Since successful infection is restricted only to a part of the Paramecium population and since the number of primarily established endosymbionts does not depend on the number of ingested algae, the success of infection and the formation of perialgal vacuoles seem to be not limited by properties of the algae but by features of the host, the possible nature of which is discussed.}, }
@article {pmid19171941, year = {2009}, author = {Sun, S and Cline, TW}, title = {Effects of Wolbachia infection and ovarian tumor mutations on Sex-lethal germline functioning in Drosophila.}, journal = {Genetics}, volume = {181}, number = {4}, pages = {1291-1301}, pmid = {19171941}, issn = {0016-6731}, support = {R01 GM023468/GM/NIGMS NIH HHS/United States ; GM23468/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila Proteins/*genetics/metabolism/*physiology ; Drosophila melanogaster/*genetics/physiology ; Epistasis, Genetic/physiology ; Female ; Gene Dosage ; Gene Expression Regulation, Developmental ; Germ Cells/*metabolism/physiology ; Mutation/physiology ; Ovary/growth &amp; development/metabolism ; RNA-Binding Proteins/genetics/metabolism/*physiology ; Recombination, Genetic ; Rickettsiaceae Infections/*genetics/physiopathology/veterinary ; Vitellogenesis/genetics ; Vitellogenins/genetics/metabolism ; *Wolbachia/physiology ; X Chromosome/genetics ; }, abstract = {Wolbachia is a ubiquitous intracellular endosymbiont of invertebrates. Surprisingly, infection of Drosophila melanogaster by this maternally inherited bacterium restores fertility to females carrying ovarian tumor (cystocyte overproliferation) mutant alleles of the Drosophila master sex-determination gene, Sex-lethal (Sxl). We scanned the Drosophila genome for effects of infection on transcript levels in wild-type previtellogenic ovaries that might be relevant to this suppression of female-sterile Sxl mutants by Wolbachia. Yolk protein gene transcript levels were most affected, being reduced by infection, but no genes showed significantly more than a twofold difference. The yolk gene effect likely signals a small, infection-induced delay in egg chamber maturation unrelated to suppression. In a genetic study of the Wolbachia-Sxl interaction, we established that germline Sxl controls meiotic recombination as well as cystocyte proliferation, but Wolbachia only influences the cystocyte function. In contrast, we found that mutations in ovarian tumor (otu) interfere with both Sxl germline functions. We were led to otu through characterization of a spontaneous dominant suppressor of the Wolbachia-Sxl interaction, which proved to be an otu mutation. Clearly Sxl and otu work together in the female germline. These studies of meiosis in Sxl mutant females revealed that X chromosome recombination is considerably more sensitive than autosomal recombination to reduced Sxl activity.}, }
@article {pmid19170725, year = {2009}, author = {Sato, T and Hongoh, Y and Noda, S and Hattori, S and Ui, S and Ohkuma, M}, title = {Candidatus Desulfovibrio trichonymphae, a novel intracellular symbiont of the flagellate Trichonympha agilis in termite gut.}, journal = {Environmental microbiology}, volume = {11}, number = {4}, pages = {1007-1015}, doi = {10.1111/j.1462-2920.2008.01827.x}, pmid = {19170725}, issn = {1462-2920}, mesh = {Animals ; Bacterial Proteins/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Desulfovibrio/*classification/*isolation &amp; purification/physiology ; Eukaryota/*microbiology ; Gastrointestinal Tract/*parasitology ; Genes, rRNA ; In Situ Hybridization, Fluorescence ; Isoptera/*parasitology ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {Rs-N31, a 16S rRNA phylotype affiliated with the genus Desulfovibrio, has frequently been detected from the gut of the wood-feeding termite Reticulitermes speratus. In this study, we designed a probe specifically targeting phylotype Rs-N31 and performed fluorescence in situ hybridization to identify the corresponding cells. The signals were detected exclusively inside the cells of the flagellate Trichonympha agilis, which simultaneously harbours another intracellular bacterium belonging to the candidate phylum Termite Group 1 (TG1). The detected cells were coccoid or short rods and specifically localized in the cortical layer of mainly, the anterior part of the flagellate cell. Approximately 1800 cells were contained in a single host cell, accounting for, in total, 2% of the whole prokaryotic gut microbiota. The genes dsrAB and apsA for sulfate reduction and a gene-encoding H(2)-uptake hydrogenase, both possessing a high sequence identity with those of known desulfovibrios, were obtained by polymerase chain reaction (PCR) from the host cells isolated using a micromanipulator, and their expression was verified by reverse-transcription PCR. Thus, we suggest that this endosymbiont acts as a sink for the hydrogen generated by both the flagellates and possibly TG1 symbionts. For this uncultured bacterium, we propose a novel species, 'Candidatus Desulfovibrio trichonymphae'.}, }
@article {pmid19169549, year = {2008}, author = {Copeland, CS and Matthews, RW and González, JM and Aluja, M and Sivinski, J}, title = {Wolbachia in two populations of Melittobia digitata Dahms (Hymenoptera: Eulophidae).}, journal = {Neotropical entomology}, volume = {37}, number = {6}, pages = {633-640}, doi = {10.1590/s1519-566x2008000600002}, pmid = {19169549}, issn = {1519-566X}, mesh = {Animals ; Female ; Hymenoptera/*microbiology ; Male ; Polymerase Chain Reaction ; Wolbachia/*isolation &amp; purification ; }, abstract = {We investigated two populations of Melittobia digitata Dahms, a gregarious parasitoid (primarily upon a wide range of solitary bees, wasps, and flies), in search of Wolbachia infection. The first population, from Xalapa, Mexico, was originally collected from and reared on Mexican fruit fly pupae, Anastrepha ludens Loew (Diptera: Tephritidae); the other, from Athens, Georgia, was collected from and reared on prepupae of mud dauber wasps, Trypoxylon politum Say (Hymenoptera: Crabronidae). PCR studies of the ITS2 region corroborated that both parasitoid populations were the same species; this potentially provides a useful molecular taxonomic profile since females of Melittobia species are superficially similar. Amplification of the Wolbachia surface protein gene (wsp) confirmed the presence of this endosymbiont in both populations. Sequencing revealed that the Wolbachia harbored in both populations exhibited a wsp belonging to a unique subgroup (denoted here as Dig) within the B-supergroup of known wsp genes. This new subgroup of wsp may either belong to a different strain of Wolbachia from those previously found to infect Melittobia or may be the result of a recombination event. In either case, known hosts of Wolbachia with a wsp of this subgroup are only distantly related taxonomically. Reasons are advanced as to why Melittobia - an easily reared and managed parasitoid - holds promise as an instructive model organism of Wolbachia infection amenable to the investigation of Wolbachia strains among its diverse hosts.}, }
@article {pmid19157810, year = {2009}, author = {Yoshida, M and Nakayama, T and Inouye, I}, title = {Nuclearia thermophila sp. nov. (Nucleariidae), a new nucleariid species isolated from Yunoko Lake in Nikko (Japan).}, journal = {European journal of protistology}, volume = {45}, number = {2}, pages = {147-155}, doi = {10.1016/j.ejop.2008.09.004}, pmid = {19157810}, issn = {1618-0429}, mesh = {Animals ; DNA, Ribosomal/genetics ; Eukaryota/*classification/cytology/*physiology/ultrastructure ; *Fresh Water ; Japan ; Molecular Sequence Data ; Phagocytosis/physiology ; Phylogeny ; }, abstract = {A new species of unicellular opisthokont protist, Nuclearia thermophila sp. nov., was isolated from the warm spring water of Yunoko Lake, Japan, and has been described using light and electron microscopy. It exists as a spherical floating form and a flattened amoeboid form showing various shapes. The cells occasionally extended as branches or knobbed filopodia. The spherical form when suspended in medium measured 20-40microm in diameter (excluding filopodia). The amoeboid form may exceed 65microm along the longest axis. A nucleus with an obvious spherical nucleolus, dictyosomes, mitochondria with flat cristae, food vacuoles, and lipid droplet-like vacuoles with homogeneous contents were observed; no extracellular matrix or bacterial endosymbionts were present. The cells ingested flour particles. No cysts were seen. The molecular phylogenetic tree constructed on the basis of the small subunit ribosomal DNA revealed the novelty of N. thermophila and its relationships with previously known nucleariids.}, }
@article {pmid19154382, year = {2009}, author = {Wade, MJ and Brandvain, Y}, title = {Reversing mother's curse: selection on male mitochondrial fitness effects.}, journal = {Evolution; international journal of organic evolution}, volume = {63}, number = {4}, pages = {1084-1089}, pmid = {19154382}, issn = {1558-5646}, support = {1T32HD49336/HD/NICHD NIH HHS/United States ; R01 GM084238/GM/NIGMS NIH HHS/United States ; R01 GM084238-01/GM/NIGMS NIH HHS/United States ; R01GM084238-01/GM/NIGMS NIH HHS/United States ; T32 HD049336/HD/NICHD NIH HHS/United States ; }, mesh = {Alleles ; Animals ; Female ; Humans ; Inbreeding ; Male ; Mitochondria/*genetics ; *Models, Biological ; Reproduction/genetics/*physiology ; Selection, Genetic ; }, abstract = {Many essential organelles and endosymbionts exhibit a strict matrilineal pattern of inheritance. The absence of paternal transmission of such extranuclear components is thought to preclude a response to selection on their effects on male viability and fertility. We overturn this dogma by showing that two mechanisms, inbreeding and kin selection, allow mitochondria to respond to selection on both male viability and fertility. Even modest levels of inbreeding allow such a response to selection when there are direct fitness effects of mitochondria on male fertility because inbreeding associates male fertility traits with mitochondrial matrilines. Male viability effects of mitochondria are also selectable whenever there are indirect fitness effects of males on the fitness of their sisters. When either of these effects is sufficiently strong, we show that there are conditions that allow the spread of mitochondria with direct effects that are harmful to females, contrary to standard expectation. We discuss the implications of our findings for the evolution of organelles and endosymbionts and genomic conflict.}, }
@article {pmid19149895, year = {2009}, author = {Bonte, D and Hovestadt, T and Poethke, HJ}, title = {Sex-specific dispersal and evolutionary rescue in metapopulations infected by male killing endosymbionts.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {16}, pmid = {19149895}, issn = {1471-2148}, mesh = {Animals ; Arthropods/genetics/*parasitology ; *Biological Evolution ; Computer Simulation ; Female ; Host-Pathogen Interactions ; Male ; Population Dynamics ; Sex Ratio ; Symbiosis ; }, abstract = {BACKGROUND: Male killing endosymbionts manipulate their arthropod host reproduction by only allowing female embryos to develop into infected females and killing all male offspring. Because the resulting change in sex ratio is expected to affect the evolution of sex-specific dispersal, we investigated under which environmental conditions strong sex-biased dispersal would emerge, and how this would affect host and endosymbiont metapopulation persistence.<br><br>RESULTS: We simulated host-endosymbiont metapopulation dynamics in an individual-based model, in which dispersal rates are allowed to evolve independently for the two sexes. Prominent male-biased dispersal emerges under conditions of low environmental stochasticity and high dispersal mortality. By applying a reshuffling algorithm, we show that kin-competition is a major driver of this evolutionary pattern because of the high within-population relatedness of males compared to those of females. Moreover, the evolution of sex-specific dispersal rescues metapopulations from extinction by (i) reducing endosymbiont fixation rates and (ii) by enhancing the extinction of endosymbionts within metapopulations that are characterized by low environmental stochasticity.<br><br>CONCLUSION: Male killing endosymbionts induce the evolution of sex-specific dispersal, with prominent male-biased dispersal under conditions of low environmental stochasticity and high dispersal mortality. This male-biased dispersal emerges from stronger kin-competition in males compared to females and induces an evolutionary rescue mechanism.}, }
@article {pmid19145467, year = {2009}, author = {De Luna, CJ and Moro, CV and Guy, JH and Zenner, L and Sparagano, OA}, title = {Endosymbiotic bacteria living inside the poultry red mite (Dermanyssus gallinae).}, journal = {Experimental &amp; applied acarology}, volume = {48}, number = {1-2}, pages = {105-113}, pmid = {19145467}, issn = {1572-9702}, mesh = {Animals ; Bacteroidetes/classification/genetics/*isolation &amp; purification ; Base Sequence ; Coxiellaceae/classification/genetics/*isolation &amp; purification ; France ; Mites/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Spiroplasma/classification/genetics/*isolation &amp; purification ; Symbiosis ; United Kingdom ; Xanthomonadaceae/classification/genetics/*isolation &amp; purification ; }, abstract = {This study investigated the endosymbiotic bacteria living inside the poultry red mite collected from five samples of one commercial farm from the UK and 16 farms from France using genus-specific PCR, PCR-TTGE and DNA sequencing. Endosymbiotic bacteria are intracellular obligate organisms that can cause several phenotypic and reproductive anomalies to their host and they are found widespread living inside arthropods. The farm sampled from the UK was positive for bacteria of the genera Cardinium sp. and Spiroplasma sp. From France, 7 farms were positive for Cardinium sp., 1 farm was positive for Spiroplasma sp., 1 farm was positive for Rickettsiella sp. and 2 farms were positive for Schineria sp. However, it was not possible to detect the presence of the genus Wolbachia sp. which has been observed in other ectoparasites. This study is the first report of the presence of endosymbionts living inside the poultry red mite. The results obtained suggest that it may be possible that these bacterial endosymbionts cause biological modifications to the poultry red mite.}, }
@article {pmid19138386, year = {2009}, author = {Hinderhofer, M and Walker, CA and Friemel, A and Stuermer, CA and Möller, HM and Reuter, A}, title = {Evolution of prokaryotic SPFH proteins.}, journal = {BMC evolutionary biology}, volume = {9}, number = {}, pages = {10}, pmid = {19138386}, issn = {1471-2148}, mesh = {Amino Acid Sequence ; Bacterial Proteins/chemistry/*genetics ; Conserved Sequence ; Databases, Protein ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Genome, Bacterial ; Membrane Proteins/chemistry/*genetics ; Molecular Sequence Data ; Operon ; Phylogeny ; Protein Structure, Tertiary ; Sequence Alignment ; Sequence Analysis, Protein ; }, abstract = {BACKGROUND: The SPFH protein superfamily is a diverse family of proteins whose eukaryotic members are involved in the scaffolding of detergent-resistant microdomains. Recently the origin of the SPFH proteins has been questioned. Instead, convergent evolution has been proposed. However, an independent, convergent evolution of three large prokaryotic and three eukaryotic families is highly unlikely, especially when other mechanisms such as lateral gene transfer which could also explain their distribution pattern have not yet been considered.To gain better insight into this very diverse protein family, we have analyzed the genomes of 497 microorganisms and investigated the pattern of occurrence as well as the genomic vicinity of the prokaryotic SPFH members.<br><br>RESULTS: According to sequence and operon structure, a clear division into 12 subfamilies was evident. Three subfamilies (SPFH1, SPFH2 and SPFH5) show a conserved operon structure and two additional subfamilies are linked to those three through functional aspects (SPFH1, SPFH3, SPFH4: interaction with FtsH protease). Therefore these subgroups most likely share common ancestry. The complex pattern of occurrence among the different phyla is indicative of lateral gene transfer. Organisms that do not possess a single SPFH protein are almost exclusively endosymbionts or endoparasites.<br><br>CONCLUSION: The conserved operon structure and functional similarities suggest that at least 5 subfamilies that encompass almost 75% of all prokaryotic SPFH members share a common origin. Their similarity to the different eukaryotic SPFH families, as well as functional similarities, suggests that the eukaryotic SPFH families originated from different prokaryotic SPFH families rather than one. This explains the difficulties in obtaining a consistent phylogenetic tree of the eukaryotic SPFH members. Phylogenetic evidence points towards lateral gene transfer as one source of the very diverse patterns of occurrence in bacterial species.}, }
@article {pmid19135368, year = {2009}, author = {Nakanishi, H and Suzuki, K and Kabeya, Y and Miyagishima, SY}, title = {Plant-specific protein MCD1 determines the site of chloroplast division in concert with bacteria-derived MinD.}, journal = {Current biology : CB}, volume = {19}, number = {2}, pages = {151-156}, doi = {10.1016/j.cub.2008.12.018}, pmid = {19135368}, issn = {1879-0445}, mesh = {Arabidopsis/cytology/metabolism ; Arabidopsis Proteins/genetics/metabolism ; Bacterial Proteins/genetics/*metabolism ; *Chloroplasts/physiology/ultrastructure ; Intracellular Membranes/metabolism/ultrastructure ; Plant Proteins/genetics/*metabolism ; Recombinant Fusion Proteins/genetics/metabolism ; }, abstract = {Chloroplasts evolved from a cyanobacterial endosymbiont, and chloroplast division requires the formation of an FtsZ division ring, which is descended from the cytokinetic machinery of cyanobacteria. As in bacteria, the positioning of the chloroplast FtsZ ring is regulated by the proteins MinD and MinE. However, chloroplast division also involves mechanisms invented by the eukaryotic host cell. Here we show that a plant-specific protein MULTIPLE CHLOROPLAST DIVISION SITE 1 (MCD1) regulates FtsZ ring positioning in Arabidopsis thaliana chloroplasts. Our analyses show that both MCD1 and MinD are required for chloroplast division, localizing at the division sites and punctate structures dispersed on the inner envelope. MinD overexpression inhibited FtsZ ring formation whereas MCD1 overexpression did not. Localization studies suggest that MCD1 is required for MinD localization to regulate FtsZ ring formation. Furthermore, the interaction between MCD1 and MinD in yeast two-hybrid assays suggests that MCD1 recruits MinD by direct interaction. These results point out differences in the MinD localization mechanism between chloroplasts and bacterial model systems and suggest that the plant cell evolved a component to modulate the cyanobacteria-derived Min system so as to regulate chloroplast FtsZ ring positioning.}, }
@article {pmid19133077, year = {2008}, author = {Tortosa, P and Courtiol, A and Moutailler, S and Failloux, AB and Weill, M}, title = {Chikungunya-Wolbachia interplay in Aedes albopictus.}, journal = {Insect molecular biology}, volume = {17}, number = {6}, pages = {677-684}, doi = {10.1111/j.1365-2583.2008.00842.x}, pmid = {19133077}, issn = {1365-2583}, mesh = {Aedes/*microbiology/*virology ; Animals ; Bacteriophages/*genetics ; Chikungunya virus/*genetics ; DNA Primers/genetics ; Female ; Host-Parasite Interactions ; *Insect Vectors ; Plasmids/genetics ; Polymerase Chain Reaction ; Reunion ; Sex Factors ; Virus Replication/physiology ; Wolbachia/genetics/*virology ; }, abstract = {A severe Chikungunya (CHIK) outbreak recently hit several countries of the Indian Ocean. On La Réunion Island, Aedes albopictus was incriminated as the major vector. This mosquito species is naturally co-infected with two distinct strains of the endosymbiont Wolbachia, namely wAlbA and wAlbB, which are increasingly attracting interest as potential tools for vector control. A PCR quantitative assay was developed to investigate Wolbachia/mosquito host interactions. We show that Wolbachia densities are slightly decreased in CHIK virus (CHIKV)-infected females. We measured the impact of CHIKV replication on a lysogenic virus: WO bacteriophage. Our data indicate that WO is sheltered by wAlbB, likely at a single copy per bacteria, and that CHIKV replication is not a physiological stress triggering WO entrance into the lytic cycle.}, }
@article {pmid19127968, year = {2008}, author = {Grandi, G and Morchon, R and Kramer, L and Kartashev, V and Simon, F}, title = {Wolbachia in Dirofilaria repens, an agent causing human subcutaneous dirofilariasis.}, journal = {The Journal of parasitology}, volume = {94}, number = {6}, pages = {1421-1423}, doi = {10.1645/GE-1575.1}, pmid = {19127968}, issn = {0022-3395}, mesh = {Adult ; Animals ; Antibodies, Bacterial/blood ; Bacterial Proteins/immunology ; Dirofilaria/immunology/*microbiology/pathogenicity ; Dirofilariasis/immunology/*parasitology/pathology ; Female ; Granuloma/immunology/*parasitology/pathology ; Humans ; Immunoglobulin G/blood ; Immunohistochemistry ; Male ; Membrane Proteins/immunology ; Middle Aged ; Skin Diseases, Parasitic/immunology/*parasitology/pathology ; Symbiosis ; Wolbachia/immunology/*physiology ; Young Adult ; }, abstract = {Human subcutaneous dirofilariasis is an increasingly reported zoonosis caused by several filarial species, in particular by Dirofilaria (Nochtiella) repens. Like many filarial worms, D. repens harbors the bacterial endosymbiont Wolbachia that has been implicated in the inflammatory features of filarial infection. Immunohistochemical staining against the Wolbachia surface protein (WSP) was carried out on 14 skin nodules and showed numerous bacteria within the intact worms and occasional positive staining within the surrounding inflammatory infiltrate. Serum samples from 11 of these patients resulted positive for total immunoglobulin G titers against WSP as examined in enzyme-linked immunosorbent assay. This is the first description of Wolbachia distribution in D. repens and the first report of specific immune response to Wolbachia in patients with subcutaneous dirofilariasis.}, }
@article {pmid19126868, year = {2009}, author = {Toft, C and Fares, MA}, title = {Selection for translational robustness in Buchnera aphidicola, endosymbiotic bacteria of aphids.}, journal = {Molecular biology and evolution}, volume = {26}, number = {4}, pages = {743-751}, doi = {10.1093/molbev/msn301}, pmid = {19126868}, issn = {1537-1719}, mesh = {Bacterial Proteins/*genetics ; Buchnera/*genetics/physiology ; *Evolution, Molecular ; Protein Biosynthesis ; }, abstract = {Its strong intergenerational bottlenecks and effectively asexual reproduction have led Buchnera aphidicola, the endocellular symbiotic bacterium of aphids, to spectacular evolutionary and genomic changes in comparison with its free-living bacterial cousins. These changes summarize into high fixation rates of mildly deleterious destabilizing mutations. This predicts a sharp decline of its fitness and the consequent early demise of this endosymbiotic bacterium. Its survival for hundreds of millions of years casts doubt on genetic drift as the sole evolutionary force and seeks further explanation. We identify in Buchnera selection to increase the robustness of proteins to misfolding translation errors. Translational robustness varies between Buchnera lineages and protein functional categories. Metabolic proteins have been under selection for translational efficiency, whereas evolutionary rates of proteins involved in fundamental cellular processes have been largely determined by selection for translational robustness. We detect the strongest signal of translational robustness in B. aphidicola Cinara cedri with a very similar pattern to that inferred for the most common symbiotic ancestor of Buchnera lineages. This indicates that B. aphidicola Cinara cedri lineage may have probably reached the minimum evolutionary stable gene composition for endosymbiotic lifestyle. The evolutionary patterns from the comparative genomic analyses of these endosymbionts support a paradoxically complex dynamic for apparently simple genomes.}, }
@article {pmid19120467, year = {2009}, author = {Brissac, T and Gros, O and Merçot, H}, title = {Lack of endosymbiont release by two Lucinidae (Bivalvia) of the genus Codakia: consequences for symbiotic relationships.}, journal = {FEMS microbiology ecology}, volume = {67}, number = {2}, pages = {261-267}, doi = {10.1111/j.1574-6941.2008.00626.x}, pmid = {19120467}, issn = {1574-6941}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Bivalvia/classification/growth &amp; development/*microbiology/*ultrastructure ; *Gills/microbiology/ultrastructure ; In Situ Hybridization, Fluorescence/methods ; Microscopy, Electron, Transmission ; Oxidation-Reduction ; Seawater/microbiology ; Species Specificity ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Associations between marine invertebrates and chemoautotrophic bacteria constitute a wide field for the study of symbiotic associations. In these interactions, symbiont transmission must represent the cornerstone allowing the persistence of the association throughout generations. Within Bivalvia, in families such as Solemyidae or Vesicomyidae, symbiont transmission is undoubtedly vertical. However, in Lucinidae, symbiont transmission is described in the literature as 'environmental', symbionts being acquired from the environment by the new host generations. Hence, if there is transmission, symbionts should be transmitted from adults to juveniles via the environment. Consequently, we should observe a release of the symbiont by adults. We attempted to detect such a release within two Lucinidae species of the genus Codakia. We sampled 10 Codakia orbicularis and 20 Codakia orbiculata distributed in 10 crystallizing dishes containing filtered seawater. During 1 month of investigation, we analyzed water of the dishes in order to detect any release of a symbiont using catalyzed report deposition-FISH techniques. For 140 observations realized during this period, we did not observe any release of symbionts. This suggests that the idea of host-to-host passage in Lucinidae is inaccurate. We could therefore consider that the transmission mode from generation to generation does not occur within Lucinidae, symbiosis appearing to be advantageous in this case only for the host, and constitutes an evolutionary dead-end for the bacteria.}, }
@article {pmid19116010, year = {2008}, author = {Desjardins, CA and Gundersen-Rindal, DE and Hostetler, JB and Tallon, LJ and Fadrosh, DW and Fuester, RW and Pedroni, MJ and Haas, BJ and Schatz, MC and Jones, KM and Crabtree, J and Forberger, H and Nene, V}, title = {Comparative genomics of mutualistic viruses of Glyptapanteles parasitic wasps.}, journal = {Genome biology}, volume = {9}, number = {12}, pages = {R183}, pmid = {19116010}, issn = {1474-760X}, mesh = {Animals ; DNA Transposable Elements ; Genome, Viral ; Molecular Sequence Data ; Polydnaviridae/*genetics/physiology ; Proviruses/genetics ; Wasps/*virology ; }, abstract = {BACKGROUND: Polydnaviruses, double-stranded DNA viruses with segmented genomes, have evolved as obligate endosymbionts of parasitoid wasps. Virus particles are replication deficient and produced by female wasps from proviral sequences integrated into the wasp genome. These particles are co-injected with eggs into caterpillar hosts, where viral gene expression facilitates parasitoid survival and, thereby, survival of proviral DNA. Here we characterize and compare the encapsidated viral genome sequences of bracoviruses in the family Polydnaviridae associated with Glyptapanteles gypsy moth parasitoids, along with near complete proviral sequences from which both viral genomes are derived.<br><br>RESULTS: The encapsidated Glyptapanteles indiensis and Glyptapanteles flavicoxis bracoviral genomes, each composed of 29 different size segments, total approximately 517 and 594 kbp, respectively. They are generated from a minimum of seven distinct loci in the wasp genome. Annotation of these sequences revealed numerous novel features for polydnaviruses, including insect-like sugar transporter genes and transposable elements. Evolutionary analyses suggest that positive selection is widespread among bracoviral genes.<br><br>CONCLUSIONS: The structure and organization of G. indiensis and G. flavicoxis bracovirus proviral segments as multiple loci containing one to many viral segments, flanked and separated by wasp gene-encoding DNA, is confirmed. Rapid evolution of bracovirus genes supports the hypothesis of bracovirus genes in an 'arms race' between bracovirus and caterpillar. Phylogenetic analyses of the bracoviral genes encoding sugar transporters provides the first robust evidence of a wasp origin for some polydnavirus genes. We hypothesize transposable elements, such as those described here, could facilitate transfer of genes between proviral segments and host DNA.}, }
@article {pmid19114486, year = {2009}, author = {Salzberg, SL and Puiu, D and Sommer, DD and Nene, V and Lee, NH}, title = {Genome sequence of the Wolbachia endosymbiont of Culex quinquefasciatus JHB.}, journal = {Journal of bacteriology}, volume = {191}, number = {5}, pages = {1725}, pmid = {19114486}, issn = {1098-5530}, support = {R01 GM083873/GM/NIGMS NIH HHS/United States ; R01-LM006845/LM/NLM NIH HHS/United States ; R01 LM006845-09/LM/NLM NIH HHS/United States ; R01 LM006845/LM/NLM NIH HHS/United States ; R01 GM083873-05/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Culex/*microbiology ; *Genome, Bacterial ; Molecular Sequence Data ; *Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*genetics ; }, abstract = {Wolbachia species are endosymbionts of a wide range of invertebrates, including mosquitoes, fruit flies, and nematodes. The wPip strains can cause cytoplasmic incompatibility in some strains of the Culex mosquito. Here we describe the genome sequence of a Wolbachia strain that was discovered in the whole-genome sequencing data for the mosquito Culex quinquefasciatus strain JHB.}, }
@article {pmid19077212, year = {2008}, author = {Braeken, K and Fauvart, M and Vercruysse, M and Beullens, S and Lambrichts, I and Michiels, J}, title = {Pleiotropic effects of a rel mutation on stress survival of Rhizobium etli CNPAF512.}, journal = {BMC microbiology}, volume = {8}, number = {}, pages = {219}, pmid = {19077212}, issn = {1471-2180}, mesh = {Colony Count, Microbial ; Hydrogen Peroxide/metabolism ; Ligases/*genetics/metabolism ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; *Mutation ; Phenotype ; Rhizobium etli/cytology/genetics/growth &amp; development/*physiology ; Sodium Chloride/metabolism ; *Stress, Physiological ; Temperature ; }, abstract = {BACKGROUND: The rel gene of Rhizobium etli (relRet), the nodulating endosymbiont of the common bean plant, determines the cellular level of the alarmone (p)ppGpp and was previously shown to affect free-living growth and symbiosis. Here, we demonstrate its role in cellular adaptation and survival in response to various stresses.<br><br>RESULTS: Growth of the R. etli relRet mutant was strongly reduced or abolished in the presence of elevated NaCl levels or at 37 degrees C, compared to the wild type. In addition, depending on the cell density, decreased survival of exponentially growing or stationary phase relRet mutant cells was obtained after H2O2, heat or NaCl shock compared to the wild-type strain. Survival of unstressed stationary phase cultures was differentially affected depending on the growth medium used. Colony forming units (CFU) of relRet mutant cultures continuously decreased in minimal medium supplemented with succinate, whereas wild-type cultures stabilised at higher CFU levels. Microscopic examination of stationary phase cells indicated that the relRet mutant was unable to reach the typical coccoid morphology of the wild type in stationary phase cultures. Assessment of stress resistance of re-isolated bacteroids showed increased sensitivity of the relRet mutant to H2O2 and a slightly increased resistance to elevated temperature (45 degrees C) or NaCl shock, compared to wild-type bacteroids.<br><br>CONCLUSION: The relRet gene is an important factor in regulating rhizobial physiology, during free-living growth as well as in symbiotic conditions. Additionally, differential responses to several stresses applied to bacteroids and free-living exponential or stationary phase cells point to essential physiological differences between the different states.}, }
@article {pmid19076736, year = {2009}, author = {Yli-Pirilä, T and Kusnetsov, J and Hirvonen, MR and Seuri, M and Nevalainen, A}, title = {Survival of amoebae on building materials.}, journal = {Indoor air}, volume = {19}, number = {2}, pages = {113-121}, doi = {10.1111/j.1600-0668.2008.00567.x}, pmid = {19076736}, issn = {1600-0668}, mesh = {Amoeba/*growth &amp; development ; Animals ; Construction Materials/microbiology/*parasitology ; Environment, Controlled ; Escherichia coli/growth &amp; development ; Water ; }, abstract = {UNLABELLED: Moisture damage and concurrent microbial growth in buildings are associated with adverse health effects among the occupants. However, the causal agents for the symptoms are unclear although microbes are assumed to play a major role. Fungi and bacteria are not the only microbes inhabiting moist building materials; it was recently revealed that amoebae are also present. As amoebae have the potential to harbor many pathogens and to modulate the characteristics of growing microbes, a better appreciation of the growth and survival of amoebae in moisture damage conditions will add to the understanding of their effects on health outcomes. In this study, we investigated the ability of amoebae to survive on six building materials. Furthermore, both aged and unused materials were tested. Amoebae survived on gypsum board and mineral wool for the whole 2 months experiment even without additional sustenance. When sustenance (heat-killed bacteria) was available, aged pine wood and birch wood also allowed their survival. In contrast, amoebae were quickly killed on fresh pine wood and they did not survive on concrete or linoleum. In conclusion, our data show that amoebae can persist on several common building materials once these materials become wet.<br><br>PRACTICAL IMPLICATIONS: Amoebae are able to survive on many building materials should the materials become wet. Amoebae have the potential to increase growth, cytotoxicity, and pathogenicity of other microbes present in moisture damages, and they may carry potentially pathogenic bacteria as endosymbionts and thus introduce them into the indoor air. Therefore, amoebae may have a prominent role in the microbial exposures occurring in moisture-damaged buildings. The presence of amoebae could be usefully included in reporting the microbial damage of material samples.}, }
@article {pmid19074760, year = {2009}, author = {Turmel, M and Gagnon, MC and O'Kelly, CJ and Otis, C and Lemieux, C}, title = {The chloroplast genomes of the green algae Pyramimonas, Monomastix, and Pycnococcus shed new light on the evolutionary history of prasinophytes and the origin of the secondary chloroplasts of euglenids.}, journal = {Molecular biology and evolution}, volume = {26}, number = {3}, pages = {631-648}, doi = {10.1093/molbev/msn285}, pmid = {19074760}, issn = {1537-1719}, mesh = {Animals ; Chlorophyta/*genetics ; Chloroplasts/*genetics ; DNA, Algal ; Euglenida/*genetics ; *Genome, Chloroplast ; Sequence Analysis, DNA ; }, abstract = {Because they represent the earliest divergences of the Chlorophyta and include the smallest known eukaryotes (e.g., the coccoid Ostreococcus), the morphologically diverse unicellular green algae making up the Prasinophyceae are central to our understanding of the evolutionary patterns that accompanied the radiation of chlorophytes and the reduction of cell size in some lineages. Seven prasinophyte lineages, four of which exhibit a coccoid cell organization (no flagella nor scales), were uncovered from analysis of nuclear-encoded 18S rDNA data; however, their order of divergence remains unknown. In this study, the chloroplast genome sequences of the scaly quadriflagellate Pyramimonas parkeae (clade I), the coccoid Pycnococcus provasolii (clade V), and the scaly uniflagellate Monomastix (unknown affiliation) were determined, annotated, and compared with those previously reported for green algae/land plants, including two prasinophytes (Nephroselmis olivacea, clade III and Ostreococcus tauri, clade II). The chlorarachniophyte Bigelowiella natans and the euglenid Euglena gracilis, whose chloroplasts originate presumably from distinct green algal endosymbionts, were also included in our comparisons. The three newly sequenced prasinophyte genomes differ considerably from one another and from their homologs in overall structure, gene content, and gene order, with the 80,211-bp Pycnococcus and 114,528-bp Monomastix genomes (98 and 94 conserved genes, respectively) resembling the 71,666-bp Ostreococcus genome (88 genes) in featuring a significantly reduced gene content. The 101,605-bp Pyramimonas genome (110 genes) features two conserved genes (rpl22 and ycf65) and ancestral gene linkages previously unrecognized in chlorophytes as well as a DNA primase gene putatively acquired from a virus. The Pyramimonas and Euglena cpDNAs revealed uniquely shared derived gene clusters. Besides providing unequivocal evidence that the green algal ancestor of the euglenid chloroplasts belonged to the Pyramimonadales, phylogenetic analyses of concatenated chloroplast genes and proteins elucidated the position of Monomastix and showed that the Mamiellales, a clade comprising Ostreococcus and Monomastix, are sister to the Pyramimonadales + Euglena clade. Our results also revealed that major reduction in gene content and restructuring of the chloroplast genome occurred in conjunction with important changes in cell organization in at least two independent prasinophyte lineages, the Mamiellales and the Pycnococcaceae.}, }
@article {pmid19070618, year = {2009}, author = {Matteoli, FP and d'Avila-Levy, CM and Santos, LO and Barbosa, GM and Holandino, C and Branquinha, MH and Santos, AL}, title = {Roles of the endosymbiont and leishmanolysin-like molecules expressed by Crithidia deanei in the interaction with mammalian fibroblasts.}, journal = {Experimental parasitology}, volume = {121}, number = {3}, pages = {246-253}, doi = {10.1016/j.exppara.2008.11.011}, pmid = {19070618}, issn = {1090-2449}, mesh = {3T3 Cells ; Animals ; Bacteria/*pathogenicity ; Crithidia/*microbiology/physiology ; Electrophoresis, Polyacrylamide Gel ; Fibroblasts/metabolism/*parasitology ; Flow Cytometry ; Host-Parasite Interactions ; Metalloendopeptidases/*physiology ; Mice ; Receptors, Cell Surface/analysis/metabolism ; *Symbiosis ; }, abstract = {Crithidia deanei is an insect trypanosomatid that harbors a bacterial endosymbiont in its cytoplasm. In this work, we have demonstrated the influence of the endosymbiont on the interaction of C. deanei with mammalian fibroblasts, also implicating the surface leishmanolysin-like molecules of C. deanei in this process. The wild strain of C. deanei expressed a higher amount (2-fold) of leishmanolysin-like molecules in the parasite surface than the aposymbiotic strain. The treatment of parasites with anti-leishmanolysin antibodies or the fibroblasts with purified leishmanolysin-like molecules from C. deanei significantly reduced the association index. The aposymbiotic strain of C. deanei presented interaction rates about 2- and 3-fold lower with fibroblasts than the endosymbiont-bearing counterpart after 1 and 2h, respectively. However, the association indexes were similar after 3 and 4h of interaction. Additionally, we observed a 2-fold increase in the association index after 24-96 h of parasite-fibroblast interaction when compared to the interaction process performed for 4h, irrespective to the presence of the endosymbiont, suggesting that fibroblasts support multiplication and survival of C. deanei. Both parasite strains were able to induce fibroblast lysis. Interestingly, the wild strain led to a 2-fold increase in fibroblasts death in comparison to the aposymbiotic strain after 48-96 h. We also showed that both wild and aposymbiotic biotinylated live parasites recognized the same receptor in the fibroblast cells.}, }
@article {pmid19056502, year = {2009}, author = {Linares, MC and Soto-Calderón, ID and Lees, DC and Anthony, NM}, title = {High mitochondrial diversity in geographically widespread butterflies of Madagascar: a test of the DNA barcoding approach.}, journal = {Molecular phylogenetics and evolution}, volume = {50}, number = {3}, pages = {485-495}, doi = {10.1016/j.ympev.2008.11.008}, pmid = {19056502}, issn = {1095-9513}, support = {BBS/B/04358//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Butterflies/classification/*genetics/microbiology ; DNA, Mitochondrial/*genetics ; Electron Transport Complex IV/genetics ; Evolution, Molecular ; Gene Flow ; *Genetic Variation ; Genetics, Population ; Geography ; Mitochondria/genetics ; *Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; Wolbachia/genetics ; }, abstract = {The standardized use of mitochondrial cytochrome c oxidase subunit I (COI) gene sequences as DNA barcodes has been widely promoted as a high-throughput method for species identification and discovery. Species delimitation has been based on the following criteria: (1) monophyletic association and less frequently (2) a minimum 10x greater divergence between than within species. Divergence estimates, however, can be inflated if sister species pairs are not included and the geographic extent of variation within any given taxon is not sampled comprehensively. This paper addresses both potential biases in DNA divergence estimation by sampling range-wide variation in several morphologically distinct, endemic butterfly species in the genus Heteropsis, some of which are sister taxa. We also explored the extent to which mitochondrial DNA from the barcode region can be used to assess the effects of historical rainforest fragmentation by comparing genetic variation across Heteropsis populations with an unrelated forest-associated taxon Saribia tepahi. Unexpectedly, generalized primers led to the inadvertent amplification of the endosymbiont Wolbachia, undermining the use of universal primers and necessitating the design of genus-specific COI primers alongside a Wolbachia-specific PCR assay. Regardless of the high intra-specific genetic variation observed, most species satisfy DNA barcoding criteria and can be differentiated in the nuclear phylogeny. Nevertheless, two morphologically distinguishable candidate species fail to satisfy the barcoding 10x genetic distance criterion, underlining the difficulties of applying a standard distance threshold to species delimitation. Phylogeographic analysis of COI data suggests that forest fragmentation may have played an important role in the recent evolutionary diversification of these butterflies. Further work on other Malagasy taxa using both mitochondrial and nuclear data will provide better insight into the role of historical habitat fragmentation in species diversification and may potentially contribute to the identification of priority areas for conservation.}, }
@article {pmid19055818, year = {2008}, author = {Newton, IL and Girguis, PR and Cavanaugh, CM}, title = {Comparative genomics of vesicomyid clam (Bivalvia: Mollusca) chemosynthetic symbionts.}, journal = {BMC genomics}, volume = {9}, number = {}, pages = {585}, pmid = {19055818}, issn = {1471-2164}, support = {//Howard Hughes Medical Institute/United States ; }, mesh = {Animals ; Bivalvia/*microbiology ; Comparative Genomic Hybridization ; Computational Biology ; DNA, Bacterial/genetics ; Evolution, Molecular ; Gammaproteobacteria/*genetics ; *Genome, Bacterial ; *Genomics ; Oligonucleotide Array Sequence Analysis ; Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {BACKGROUND: The Vesicomyidae (Bivalvia: Mollusca) are a family of clams that form symbioses with chemosynthetic gamma-proteobacteria. They exist in environments such as hydrothermal vents and cold seeps and have a reduced gut and feeding groove, indicating a large dependence on their endosymbionts for nutrition. Recently, two vesicomyid symbiont genomes were sequenced, illuminating the possible nutritional contributions of the symbiont to the host and making genome-wide evolutionary analyses possible.<br><br>RESULTS: To examine the genomic evolution of the vesicomyid symbionts, a comparative genomics framework, including the existing genomic data combined with heterologous microarray hybridization results, was used to analyze conserved gene content in four vesicomyid symbiont genomes. These four symbionts were chosen to include a broad phylogenetic sampling of the vesicomyid symbionts and represent distinct chemosynthetic environments: cold seeps and hydrothermal vents.<br><br>CONCLUSION: The results of this comparative genomics analysis emphasize the importance of the symbionts' chemoautotrophic metabolism within their hosts. The fact that these symbionts appear to be metabolically capable autotrophs underscores the extent to which the host depends on them for nutrition and reveals the key to invertebrate colonization of these challenging environments.}, }
@article {pmid19043737, year = {2009}, author = {Foster, JM and Raverdy, S and Ganatra, MB and Colussi, PA and Taron, CH and Carlow, CK}, title = {The Wolbachia endosymbiont of Brugia malayi has an active phosphoglycerate mutase: a candidate target for anti-filarial therapies.}, journal = {Parasitology research}, volume = {104}, number = {5}, pages = {1047-1052}, pmid = {19043737}, issn = {1432-1955}, support = {2R44 A1061865-02//PHS HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/*genetics/isolation &amp; purification/*metabolism ; Brugia malayi/*microbiology ; Cloning, Molecular ; Escherichia coli/genetics ; Gene Expression ; Kluyveromyces/genetics ; Molecular Sequence Data ; NAD/metabolism ; Phosphoglycerate Mutase/*genetics/isolation &amp; purification/*metabolism ; Sequence Alignment ; Wolbachia/*enzymology/genetics ; }, abstract = {Phosphoglycerate mutases (PGM) interconvert 2- and 3-phosphoglycerate in the glycolytic and gluconeogenic pathways. A putative cofactor-independent phosphoglycerate mutase gene (iPGM) was identified in the genome sequence of the Wolbachia endosymbiont from the filarial nematode, Brugia malayi (wBm). Since iPGM has no sequence or structural similarity to the cofactor-dependent phosphoglycerate mutase (dPGM) found in mammals, it may represent an attractive Wolbachia drug target. In the present study, wBm-iPGM cloned and expressed in Escherichia coli was mostly insoluble and inactive. However, the protein was successfully produced in the yeast Kluyveromyces lactis and the purified recombinant wBm-iPGM showed typical PGM activity. Our results provide a foundation for further development of wBm-iPGM as a promising new drug target for novel anti-filarial therapies that selectively target the endosymbiont.}, }
@article {pmid19042148, year = {2009}, author = {Gross, J and Bhattacharya, D}, title = {Revaluating the evolution of the Toc and Tic protein translocons.}, journal = {Trends in plant science}, volume = {14}, number = {1}, pages = {13-20}, doi = {10.1016/j.tplants.2008.10.003}, pmid = {19042148}, issn = {1360-1385}, mesh = {Chloroplasts/*metabolism ; *Evolution, Molecular ; Intracellular Membranes/metabolism ; Membrane Proteins/genetics/*physiology ; Phylogeny ; Plant Proteins/genetics/*physiology ; Plants/*metabolism ; Protein Subunits/physiology ; Protein Transport/genetics/physiology ; }, abstract = {The origin of the plastid from a cyanobacterial endosymbiont necessitated the establishment of specialized molecular machines (translocons) to facilitate the import of nuclear-encoded proteins into the organelle. To improve our understanding of the evolution of the translocons at the outer and inner envelope membrane of chloroplasts (Toc and Tic, respectively), we critically reassess the prevalent notion that their subunits have a function exclusive to protein import. We propose that many translocon components are multifunctional, conserving ancestral pre-endosymbiotic properties that predate their recruitment into the primitive translocon (putatively composed of subunits Toc34, Toc75 and Tic110 and associated chaperones). Multifunctionality seems to be a hallmark of the Tic complex, in which protein import is integrated with a broad array of plastid processes.}, }
@article {pmid19040455, year = {2009}, author = {Stoll, S and Feldhaar, H and Gross, R}, title = {Transcriptional profiling of the endosymbiont Blochmannia floridanus during different developmental stages of its holometabolous ant host.}, journal = {Environmental microbiology}, volume = {11}, number = {4}, pages = {877-888}, doi = {10.1111/j.1462-2920.2008.01808.x}, pmid = {19040455}, issn = {1462-2920}, mesh = {Animals ; Colony Count, Microbial ; Enterobacteriaceae/*physiology ; *Gene Expression Profiling ; Hymenoptera/*growth &amp; development/*microbiology ; Oligonucleotide Array Sequence Analysis ; }, abstract = {The transcriptome of Blochmannia floridanus, the endosymbiont of the carpenter ant Camponotus floridanus, is presented during various developmental stages of its holometabolous host by use of a whole-genome DNA macroarray. The detected transcription patterns indicate the presence of local transcription units as well as global regulatory mechanisms. Yet, the overall regulation scale is very modest, rarely exceeding a factor of three. A large number of genes show differential expression in different life stages and a distinct expression pattern of genes possibly involved in symbiotic function as compared with housekeeping genes is apparent. However, these transcriptional changes are small as compared with the changes in the number of bacteria during host development, which is the highest in pupae and in young imagines. Control of replication of the bacteria in certain life stages may therefore be the decisive parameter influencing the overall level of gene expression of Blochmannia in the animal. The few highly expressed genes like those encoding molecular chaperones exhibit a significantly higher G+C content than moderately expressed genes.}, }
@article {pmid19028913, year = {2009}, author = {Espino, CI and Gómez, T and González, G and do Santos, MF and Solano, J and Sousa, O and Moreno, N and Windsor, D and Ying, A and Vilchez, S and Osuna, A}, title = {Detection of Wolbachia bacteria in multiple organs and feces of the triatomine insect Rhodnius pallescens (Hemiptera, Reduviidae).}, journal = {Applied and environmental microbiology}, volume = {75}, number = {2}, pages = {547-550}, pmid = {19028913}, issn = {1098-5336}, mesh = {Animal Structures/*microbiology ; Animals ; Feces/*microbiology ; Rhodnius/*microbiology ; Trypanosomatina/isolation &amp; purification ; Wolbachia/*isolation &amp; purification ; }, abstract = {At least two types of Wolbachia bacteria were detected in wild and insectarium-raised Rhodnius pallescens, a natural vector of Trypanosoma cruzi and Trypanosoma rangeli. Wolbachia was detected in all the organs and tissues studied and in the feces, and this provided a methodological advantage for determining the presence of this endosymbiont in this host, obviating the need to kill the specimens. The occurrence of trypanosomatids in wild individuals was also studied.}, }
@article {pmid19027065, year = {2009}, author = {Valiente Moro, C and Thioulouse, J and Chauve, C and Normand, P and Zenner, L}, title = {Bacterial taxa associated with the hematophagous mite Dermanyssus gallinae detected by 16S rRNA PCR amplification and TTGE fingerprinting.}, journal = {Research in microbiology}, volume = {160}, number = {1}, pages = {63-70}, doi = {10.1016/j.resmic.2008.10.006}, pmid = {19027065}, issn = {0923-2508}, mesh = {Animals ; Bacteria/classification/*genetics/*isolation &amp; purification ; Biodiversity ; Chickens/parasitology ; DNA Fingerprinting ; France ; Genes, rRNA ; Mites/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/methods ; Principal Component Analysis ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; }, abstract = {Dermanyssus gallinae (Arthropoda, Mesostigmata) is suspected to be involved in the transmission of a wide variety of pathogens, but nothing is known about its associated non-pathogenic bacterial community. To address this question, we examined the composition of bacterial communities in D. gallinae collected from standard poultry farms in Brittany, France. Genetic fingerprints of bacterial communities were generated by temporal temperature gradient gel electrophoresis (TTGE) separation of individual polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments, followed by DNA sequence analysis. Most of the sequences belonged to the Proteobacteria and Firmicute phyla, with a majority of sequences corresponding to the Enterobacteriales order and the Staphylococcus genus. By using statistical analysis, we showed differences in biodiversity between poultry farms. We also determined the major phylotypes that compose the characteristic microbiota associated with D. gallinae. Saprophytes, opportunistic pathogens and pathogenic agents such as Pasteurella multocida, Erysipelothrix rhusiopathiae and sequences close to the genus Aerococcus were identified. Endosymbionts such as Schineria sp., Spiroplasma sp. Anistosticta, "Candidatus Cardinium hertigii" and Rickettsiella sp. were also present in the subdominant bacterial community. Identification of potential targets within the symbiont community may be considered in the future as a means of ectoparasite control.}, }
@article {pmid19025664, year = {2008}, author = {Tokuda, G and Lo, N and Takase, A and Yamada, A and Hayashi, Y and Watanabe, H}, title = {Purification and partial genome characterization of the bacterial endosymbiont Blattabacterium cuenoti from the fat bodies of cockroaches.}, journal = {BMC research notes}, volume = {1}, number = {}, pages = {118}, pmid = {19025664}, issn = {1756-0500}, abstract = {BACKGROUND: Symbiotic relationships between intracellular bacteria and eukaryotes are widespread in nature. Genome sequencing of the bacterial partner has provided a number of key insights into the basis of these symbioses. A challenging aspect of sequencing symbiont genomes is separating the bacteria from the host tissues. In the present study, we describe a simple method of endosymbiont purification from complex environment, using Blattabacterium cuenoti inhabiting in cockroaches as a model system.<br><br>FINDINGS: B. cuenoti cells were successfully purified from the fat bodies of the cockroach Panesthia angustipennis by a combination of slow- and fast-speed centrifugal fractionations, nylon-membrane filtration, and centrifugation with Percoll solutions. We performed pulse-field electrophoresis, diagnostic PCR and random sequencing of the shoutgun library. These experiments confirmed minimal contamination of host and mitochondrial DNA. The genome size and the G+C content of B. cuenoti were inferred to be 650 kb and 32.1 +/- 7.6%, respectively.<br><br>CONCLUSION: The present study showed successful purification and characterization of the genome of B. cuenoti. Our methodology should be applicable for future symbiont genome sequencing projects. An advantage of the present purification method is that each step is easily performed with ordinary microtubes and a microcentrifuge, and without DNase treatment.}, }
@article {pmid19025557, year = {2008}, author = {López-Sánchez, MJ and Neef, A and Patiño-Navarrete, R and Navarro, L and Jiménez, R and Latorre, A and Moya, A}, title = {Blattabacteria, the endosymbionts of cockroaches, have small genome sizes and high genome copy numbers.}, journal = {Environmental microbiology}, volume = {10}, number = {12}, pages = {3417-3422}, doi = {10.1111/j.1462-2920.2008.01776.x}, pmid = {19025557}, issn = {1462-2920}, mesh = {Animals ; Bacteroidetes/*genetics ; Blattellidae/*microbiology ; Cockroaches/*microbiology ; DNA, Bacterial/genetics ; Electrophoresis, Gel, Pulsed-Field ; Fat Body/microbiology ; *Genome, Bacterial ; In Situ Hybridization ; Periplaneta/*microbiology ; }, abstract = {Blattabacteria are intracellular endosymbionts of cockroaches and primitive termites that belong to the class Flavobacteria and live only in specialized cells in the abdominal fat body of their hosts. In the present study we determined genome sizes as well as genome copy numbers for the endosymbionts of three cockroach species, Blattella germanica, Periplaneta americana and Blatta orientalis. The sole presence of blattabacteria in the fat body was demonstrated by rRNA-targeting techniques. The genome sizes of the three blattabacteria were determined by pulsed field gel electrophoresis. The resulting total genome sizes for the three symbionts were all approximately 650 +/- 15 kb. Comparison of the genome sizes with those of free-living Bacteroidetes shows extended reduction, as occurs in other obligatory insect endosymbionts. Genome copy numbers were determined based on cell counts and determination of DNA amounts via quantitative PCR. Values between 10.2 and 18.3 and between 323 and 353 were found for the symbionts of P. americana and B. orientalis respectively. Polyploidy in intracellular bacteria may play a significant role in the genome reduction process.}, }
@article {pmid19017066, year = {2008}, author = {Montagnes, DJ and Allen, J and Brown, L and Bulit, C and Davidson, R and Díaz-Avalos, C and Fielding, S and Heath, M and Holliday, NP and Rasmussen, J and Sanders, R and Waniek, JJ and Wilson, D}, title = {Factors controlling the abundance and size distribution of the phototrophic ciliate Myrionecta rubra in open waters of the North Atlantic.}, journal = {The Journal of eukaryotic microbiology}, volume = {55}, number = {5}, pages = {457-465}, doi = {10.1111/j.1550-7408.2008.00344.x}, pmid = {19017066}, issn = {1550-7408}, mesh = {Animals ; Atlantic Ocean ; Biomass ; *Cell Count ; Ciliophora/*growth &amp; development/*isolation &amp; purification ; Nitrates/analysis ; Phytoplankton/growth &amp; development ; Seasons ; Seawater/chemistry/*parasitology ; Temperature ; }, abstract = {Myrionecta rubra, a ubiquitous planktonic ciliate, has received much attention due to its wide distribution, occurrence as a red tide organism, and unusual cryptophyte endosymbiont. Although well studied in coastal waters, M. rubra is poorly examined in the open ocean. In the Irminger Basin, North Atlantic, the abundance of M. rubra was 0-5 cells/ml, which is low compared with that found in coastal areas. Distinct patchiness (100 km) was revealed by geostatistical analysis. Multiple regression indicated there was little relationship between M. rubra abundance and a number of environmental factors, with the exception of temperature and phytoplankton biomass, which influenced abundance in the spring. We also improve on studies that indicate distinct size classes of M. rubra; we statistically recognise four significantly distinct width classes (5-16, 12-23, 18-27, 21-33 microm), which decrease in abundance with increasing size. A multinomial logistic regression revealed the main variable correlated with this size distribution was ambient nitrate concentration. Finally, we propose a hypothesis for the distribution of sizes, involving nutrients, feeding, and dividing of the endosymbiont.}, }
@article {pmid19008447, year = {2008}, author = {Hongoh, Y and Sharma, VK and Prakash, T and Noda, S and Toh, H and Taylor, TD and Kudo, T and Sakaki, Y and Toyoda, A and Hattori, M and Ohkuma, M}, title = {Genome of an endosymbiont coupling N2 fixation to cellulolysis within protist cells in termite gut.}, journal = {Science (New York, N.Y.)}, volume = {322}, number = {5904}, pages = {1108-1109}, doi = {10.1126/science.1165578}, pmid = {19008447}, issn = {1095-9203}, mesh = {Amino Acids/metabolism ; Animals ; Bacteroidetes/classification/*genetics/isolation &amp; purification/metabolism ; Cellulose/*metabolism ; Chromosomes, Bacterial/genetics ; Digestive System/metabolism/microbiology/parasitology ; Eukaryota/isolation &amp; purification/metabolism/*microbiology ; Fermentation ; Genes, Bacterial ; *Genome, Bacterial ; Glycolysis ; Isoptera/metabolism/*microbiology/parasitology ; Metabolic Networks and Pathways ; Molecular Sequence Data ; Monosaccharides/metabolism ; *Nitrogen Fixation/genetics ; Oxidoreductases/genetics ; Phylogeny ; *Symbiosis ; Wood/metabolism ; }, abstract = {Termites harbor diverse symbiotic gut microorganisms, the majority of which are as yet uncultivable and their interrelationships unclear. Here, we present the complete genome sequence of the uncultured Bacteroidales endosymbiont of the cellulolytic protist Pseudotrichonympha grassii, which accounts for 70% of the bacterial cells in the gut of the termite Coptotermes formosanus. Functional annotation of the chromosome (1,114,206 base pairs) unveiled its ability to fix dinitrogen and recycle putative host nitrogen wastes for biosynthesis of diverse amino acids and cofactors, and import glucose and xylose as energy and carbon sources. Thus, nitrogen fixation and cellulolysis are coupled within the protist's cells. This highly evolved symbiotic system probably underlies the ability of the worldwide pest termites Coptotermes to use wood as their sole food.}, }
@article {pmid18998587, year = {2008}, author = {Rodríguez, F and Feist, SW and Guillou, L and Harkestad, LS and Bateman, K and Renault, T and Mortensen, S}, title = {Phylogenetic and morphological characterisation of the green algae infesting blue mussel Mytilus edulis in the North and South Atlantic oceans.}, journal = {Diseases of aquatic organisms}, volume = {81}, number = {3}, pages = {231-240}, doi = {10.3354/dao01956}, pmid = {18998587}, issn = {0177-5103}, mesh = {Animals ; Atlantic Ocean ; Chlorophyta/*classification/cytology/physiology/*ultrastructure ; Microscopy, Electron, Transmission ; Mytilus edulis/*parasitology ; *Phylogeny ; Pigments, Biological/chemistry ; }, abstract = {Blue mussels Mytilus edulis with shell deformations and green pustules containing parasitic algae were collected at 3 coastal sites (Burøy, Norway; Bockholm, Denmark; Goose Green, Falkland Islands). A comparative study, including mussel histopathology, algal morphology, ultrastructure and phylogenetic position was performed. Green pustules were mainly located in the posterior portion of the mantle and gonad tissues and the posterior adductor muscle. Electron microscopy confirmed the presence of algal cells with similar morphology to Coccomyxa parasitica. Algae were oval shaped with a single nucleus and chloroplast, 1 or 2 mitochondria and a dense granular cytoplasm with a lipid inclusion body, Golgi apparatus and small vesicles. Partial small subunit (SSU) rRNA phylogeny confirmed the inclusion of parasitic algae into the Coccomyxa clade. However, the sequence identity between almost full SSU rRNA sequences of parasitic algae and others in this clade yielded an unexpected result. Green algae from mussels were distant from C. parasitica Culture Collection of Algae and Protozoa (CCAP) strain 216/18 (94% identity), but very similar (99% identity) to C. glaronensis (a lichen endosymbiont) and green endophytes from the tree Ginkgo biloba. The CCAP strain 216/18 was a sister sequence to Nannochloris algae, far from the Coccomyxa clade. These results suggest a misidentification or outgrowth of the original CCAP strain 216/18 by a different 'Nannochloris-like' trebouxiophycean organism. In contrast, our sequences directly obtained from infested mussels could represent the true C. parasitica responsible for the green pustules in blue mussels.}, }
@article {pmid18991607, year = {2008}, author = {Fleige, T and Soldati-Favre, D}, title = {Targeting the transcriptional and translational machinery of the endosymbiotic organelle in apicomplexans.}, journal = {Current drug targets}, volume = {9}, number = {11}, pages = {948-956}, doi = {10.2174/138945008786786073}, pmid = {18991607}, issn = {1873-5592}, mesh = {Animals ; Antiprotozoal Agents/*pharmacology ; Apicomplexa/*drug effects/genetics/metabolism ; DNA Replication/drug effects ; Genome, Plastid/genetics ; Models, Biological ; Organelles/*drug effects/genetics/metabolism ; Plastids/drug effects/genetics/metabolism ; Protein Biosynthesis/drug effects ; Transcription, Genetic/drug effects ; }, abstract = {Apicomplexans are obligate intracellular parasites causing devastating disease in both humans and livestock. Nearly all apicomplexans, with the exception of Cryptosporidium, contain two endosymbiontic organelles carrying their own DNA; the mitochondrion and the plastid-like organelle called the apicoplast. The apicoplast is an attractive drug target as it harbors not only metabolic pathways not found in the host cell, but it is also dependent on its ancient transcriptional and translational machinery. These parasites rely on the plastid, and inhibition of its function or loss of this organelle leads to immediate or delayed death. Replication of plastidic DNA shows differences between the members of this phylum. In Plasmodium parasites, two forms of replication are observed--unidirectional single-stranded replication and a rolling circle mechanism--whereas in Toxoplasma gondii only the rolling circle is found. Targeting enzymes involved in DNA-replication leads to a delayed death of the parasite. Most of the genes in the apicoplast genome encode elements of their own transcriptional and translational machinery, and they are highly similar to those found in bacteria. Several anti-bacterials which target this machinery are also active against apicomplexan parasites and inhibition leads mostly to the delayed death phenomenon.}, }
@article {pmid18990608, year = {2008}, author = {Yang, Y and Glynn, JM and Olson, BJ and Schmitz, AJ and Osteryoung, KW}, title = {Plastid division: across time and space.}, journal = {Current opinion in plant biology}, volume = {11}, number = {6}, pages = {577-584}, doi = {10.1016/j.pbi.2008.10.001}, pmid = {18990608}, issn = {1879-0356}, mesh = {Cytosol/metabolism ; Plastids/*metabolism ; Prokaryotic Cells/cytology ; Time Factors ; }, abstract = {Plastid division is executed by the coordinated action of at least two molecular machineries--an internal machinery situated on the stromal side of the inner envelope membrane that was contributed by the cyanobacterial endosymbiont from which plastids evolved, and an external machinery situated on the cytosolic side of the outer envelope membrane that was contributed by the host. Here we review progress in defining the components of the plastid division complex and understanding the mechanisms of envelope constriction and division-site placement in plants. We also highlight recent work identifying the first molecular linkage between the internal and external division machineries, shedding light on how their mid-plastid positioning is coordinated across the envelope membranes. Little is known about the mechanisms that regulate plastid division in plant cells, but recent studies have begun to hint at potential mechanisms.}, }
@article {pmid18990190, year = {2008}, author = {Cuív, PO and Keogh, D and Clarke, P and O'Connell, M}, title = {The hmuUV genes of Sinorhizobium meliloti 2011 encode the permease and ATPase components of an ABC transport system for the utilization of both haem and the hydroxamate siderophores, ferrichrome and ferrioxamine B.}, journal = {Molecular microbiology}, volume = {70}, number = {5}, pages = {1261-1273}, doi = {10.1111/j.1365-2958.2008.06479.x}, pmid = {18990190}, issn = {1365-2958}, mesh = {ATP-Binding Cassette Transporters/genetics/*metabolism ; Adenosine Triphosphatases/genetics/*metabolism ; Bacterial Outer Membrane Proteins/genetics/*metabolism ; Biological Transport ; Cosmids ; DNA, Bacterial/genetics ; Deferoxamine/metabolism ; Escherichia coli/genetics/metabolism ; Ferric Compounds/metabolism ; Ferrichrome/metabolism ; Genes, Bacterial ; Heme/*metabolism ; Hydroxamic Acids/metabolism ; Iron/metabolism ; Medicago sativa/microbiology ; Mutagenesis ; Mutation ; Nitrogen Fixation ; Periplasmic Binding Proteins/genetics/metabolism ; Siderophores/genetics/*metabolism ; Sinorhizobium meliloti/*genetics/metabolism ; Transformation, Bacterial ; }, abstract = {Sinorhizobium meliloti, the endosymbiont of Medicago sativa, can use haem compounds, including haemoglobin and leghaemoglobin, when growing in the free-living state. The components of the system involved in haem acquisition were confirmed to be ShmR, an outer membrane receptor, and HmuTUV, predicted to be an ABC transport system comprising a periplasmic protein, a permease and an ATPase respectively. The roles of HmuTUV in haem transport were confirmed in a heterologous expression system in Escherichia coli in conjunction with HasR, the outer membrane haem receptor of Serratia marcescens. hmuTUV mutants of S. meliloti showed a reduced capacity to acquire haem, suggesting the presence of a second haem acquisition system in the organism. S. meliloti can also acquire iron from xenosiderophores and the genes encoding the outer membrane receptors for ferrichrome and ferrioxamine B, fhuA1 and fhuA2, respectively, were identified. In light of this it is proposed that fhuA2 should be renamed foxA in the S. meliloti 1021 genome sequence. A siderophore reductase, FhuF, with the capacity to complement an E. coli ferrioxamine B reductase mutant, was identified encoded by a gene next to fhuA2. In the same transcriptional unit as fhuF the gene fhuP was identified and shown to encode a protein necessary for transport of ferrichrome and ferrioxamine B and predicted to be periplasmic. Interestingly, the remaining components of the transport system for the siderophores are HmuU and HmuV. Ferrichrome, ferrioxamine B and haem compounds therefore share components of the same transport system in S. meliloti.}, }
@article {pmid18988686, year = {2009}, author = {Woolfit, M and Iturbe-Ormaetxe, I and McGraw, EA and O'Neill, SL}, title = {An ancient horizontal gene transfer between mosquito and the endosymbiotic bacterium Wolbachia pipientis.}, journal = {Molecular biology and evolution}, volume = {26}, number = {2}, pages = {367-374}, doi = {10.1093/molbev/msn253}, pmid = {18988686}, issn = {1537-1719}, mesh = {Animals ; Culicidae/*genetics/*microbiology/physiology ; Drosophila melanogaster/microbiology ; Gene Transfer, Horizontal ; Phylogeny ; Symbiosis ; Wolbachia/*genetics/physiology ; }, abstract = {The extent and biological relevance of horizontal gene transfer (HGT) in eukaryotic evolution remain highly controversial. Recent studies have demonstrated frequent and large-scale HGT from endosymbiotic bacteria to their hosts, but the great majority of these transferred genes rapidly become nonfunctional in the recipient genome. Here, we investigate an ancient HGT between a host metazoan and an endosymbiotic bacterium, Wolbachia pipientis. The transferred gene has so far been found only in mosquitoes and Wolbachia. In mosquitoes, it is a member of a gene family encoding candidate receptors required for malaria sporozoite invasion of the mosquito salivary gland. The gene copy in Wolbachia has substantially diverged in sequence from the mosquito homolog, is evolving under purifying selection, and is expressed, suggesting that this gene is also functional in the bacterial genome. Several lines of evidence indicate that the gene may have been transferred from eukaryotic host to bacterial endosymbiont. Regardless of the direction of transfer, however, these results demonstrate that interdomain HGT may give rise to functional, persistent, and possibly evolutionarily significant new genes.}, }
@article {pmid18984902, year = {2009}, author = {Balbi, KJ and Rocha, EP and Feil, EJ}, title = {The temporal dynamics of slightly deleterious mutations in Escherichia coli and Shigella spp.}, journal = {Molecular biology and evolution}, volume = {26}, number = {2}, pages = {345-355}, doi = {10.1093/molbev/msn252}, pmid = {18984902}, issn = {1537-1719}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Base Composition ; Escherichia coli/classification/*genetics ; Genome, Bacterial ; *Mutation ; Principal Component Analysis ; Shigella/classification/*genetics ; Shigella sonnei/classification/genetics ; }, abstract = {The Shigella are recently emerged clones of Escherichia coli, which have independently adopted an intracellular pathogenic lifestyle. We examined the molecular evolutionary consequences of this niche specialization by comparing the normalized, directional frequency profiles of unique polymorphisms within 2,098 orthologues representing the intersection of five E. coli and four Shigella genomes. We note a surfeit of AT-enriching changes (GC-->AT), transversions, and nonsynonymous changes in the Shigella genomes. By examining these differences within a temporal framework, we conclude that our results are consistent with relaxed or inefficient selection in Shigella owing to a reduced effective population size. Alternative interpretations, and the interesting exception of Shigella sonnei, are discussed. Finally, this analysis lends support to the view that nucleotide composition typically does not lie at mutational equilibrium but that selection plays a role in maintaining a higher GC content than would result solely from mutation bias. This argument sheds light on the enrichment of adenine and thymine in the genomes of bacterial endosymbionts where purifying selection is very weak.}, }
@article {pmid18978537, year = {2008}, author = {Hoerauf, A}, title = {Filariasis: new drugs and new opportunities for lymphatic filariasis and onchocerciasis.}, journal = {Current opinion in infectious diseases}, volume = {21}, number = {6}, pages = {673-681}, doi = {10.1097/QCO.0b013e328315cde7}, pmid = {18978537}, issn = {1473-6527}, mesh = {Animals ; Doxycycline/administration &amp; dosage/*therapeutic use ; Elephantiasis, Filarial/*drug therapy ; Filaricides/administration &amp; dosage/*therapeutic use ; Humans ; Onchocerca volvulus/drug effects ; Onchocerciasis/*drug therapy ; Wuchereria bancrofti/drug effects ; }, abstract = {PURPOSE OF REVIEW: Chemotherapy against onchocerciasis and lymphatic filariasis has been discussed mainly within the framework of mass drug administration with diethylcarbamazine, ivermectin and albendazole. Although strong reductions in infection prevalence were achieved, the regimes for these drugs do not fully cover needs of individual patients who seek treatment because of symptoms. Chemotherapy against filarial Wolbachia endosymbionts with doxycycline showed higher antiparasitic efficacy in onchocerciasis and lymphatic filariasis and also improved disease. This review details the recent indications for this new treatment, focussing on regimes for individual drug administration.<br><br>RECENT FINDINGS: A regimen of 6-week/100 mg doxycycline per day sterilized adult female Onchocerca volvulus. Two hundred milligrams doxycycline per day for 4 or 6 weeks revealed 50 and 60% macrofilaricidal effects, respectively. Reduction of 80-90% of adult worms was observed in bancroftian filariasis with 200 mg/day doxycycline for 4 or 6 weeks. The latter regimen showed reduction of lymph vessel dilation and of hydrocele. Lymphoedema progression was halted and reversed in early stages.<br><br>SUMMARY: Different options for antiwolbachial individual drug administration are summarized here. With improving health systems in endemic countries, individuals will demand best-possible treatment and accelerate a shift from mass drug administration-only approaches to integrated approaches combining both mass drug administration and individual drug administration. Treatment may be further improved by new antibiotics detected in high-throughput settings.}, }
@article {pmid18974344, year = {2008}, author = {Hedges, LM and Brownlie, JC and O'Neill, SL and Johnson, KN}, title = {Wolbachia and virus protection in insects.}, journal = {Science (New York, N.Y.)}, volume = {322}, number = {5902}, pages = {702}, doi = {10.1126/science.1162418}, pmid = {18974344}, issn = {1095-9203}, mesh = {Animals ; Drosophila melanogaster/*microbiology/physiology/*virology ; Host-Pathogen Interactions ; Insect Viruses/*pathogenicity ; Nodaviridae/pathogenicity ; RNA Viruses/*pathogenicity ; Wolbachia/*physiology ; }, abstract = {Wolbachia pipientis bacteria are common endosymbionts of insects that are best known for their ability to increase their prevalence in populations by manipulating host reproductive systems. However, there are examples of Wolbachia that exist in nature that seem to induce no reproductive parasitism trait and yet are able to invade populations. We demonstrate a fitness benefit for Wolbachia-infected insects that may explain this paradox. Drosophila melanogaster flies infected with Wolbachia are less susceptible to mortality induced by a range of RNA viruses. The antiviral protection associated with Wolbachia infection might be exploited in future strategies to reduce transmission of pathogens by insects.}, }
@article {pmid18973689, year = {2008}, author = {Lohman, DJ and Peggie, D and Pierce, NE and Meier, R}, title = {Phylogeography and genetic diversity of a widespread Old World butterfly, Lampides boeticus (Lepidoptera: Lycaenidae).}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {301}, pmid = {18973689}, issn = {1471-2148}, mesh = {Animals ; Cytochromes b/genetics ; Electron Transport Complex IV/genetics ; *Genetic Variation ; Genetics, Population ; Haplotypes/genetics ; Lepidoptera/*classification/*genetics ; *Phylogeny ; }, abstract = {BACKGROUND: Evolutionary genetics provides a rich theoretical framework for empirical studies of phylogeography. Investigations of intraspecific genetic variation can uncover new putative species while allowing inference into the evolutionary origin and history of extant populations. With a distribution on four continents ranging throughout most of the Old World, Lampides boeticus (Lepidoptera: Lycaenidae) is one of the most widely distributed species of butterfly. It is placed in a monotypic genus with no commonly accepted subspecies. Here, we investigate the demographic history and taxonomic status of this widespread species, and screen for the presence or absence of the bacterial endosymbiont Wolbachia.<br><br>RESULTS: We performed phylogenetic, population genetic, and phylogeographic analyses using 1799 bp of mitochondrial sequence data from 57 specimens collected throughout the species' range. Most of the samples (>90%) were nearly genetically identical, with uncorrected pairwise sequence differences of 0-0.5% across geographic distances >9,000 km. However, five samples from central Thailand, Madagascar, northern Australia and the Moluccas formed two divergent clades differing from the majority of samples by uncorrected pairwise distances ranging from 1.79-2.21%. Phylogenetic analyses suggest that L. boeticus is almost certainly monophyletic, with all sampled genes coalescing well after the divergence from three closely related taxa included for outgroup comparisons. Analyses of molecular diversity indicate that most L. boeticus individuals in extant populations are descended from one or two relatively recent population bottlenecks.<br><br>CONCLUSION: The combined analyses suggest a scenario in which the most recent common ancestor of L. boeticus and its sister taxon lived in the African region approximately 7 Mya; extant lineages of L. boeticus began spreading throughout the Old World at least 1.5 Mya. More recently, expansion after population bottlenecks approximately 1.4 Mya seem to have displaced most of the ancestral polymorphism throughout its range, though at least two early-branching lineages still persist. One of these lineages, in northern Australia and the Moluccas, may have experienced accelerated differentiation due to infection with the bacterial endosymbiont Wolbachia, which affects reproduction. Examination of a haplotype network suggests that Australia has been colonized by the species several times. While there is little evidence for the existence of morphologically cryptic species, these results suggest a complex history affected by repeated dispersal events.}, }
@article {pmid18958153, year = {2008}, author = {Pontes, MH and Babst, M and Lochhead, R and Oakeson, K and Smith, K and Dale, C}, title = {Quorum sensing primes the oxidative stress response in the insect endosymbiont, Sodalis glossinidius.}, journal = {PloS one}, volume = {3}, number = {10}, pages = {e3541}, pmid = {18958153}, issn = {1932-6203}, mesh = {Animals ; Enterobacteriaceae/genetics/metabolism/*physiology ; Gene Expression Profiling ; Gene Expression Regulation, Bacterial ; Host-Pathogen Interactions/genetics/*physiology ; Insecta/metabolism/microbiology ; Models, Biological ; Oligonucleotide Array Sequence Analysis ; *Oxidative Stress/genetics/physiology ; Quorum Sensing/genetics/*physiology ; *Symbiosis/physiology ; Tsetse Flies/metabolism/*microbiology ; }, abstract = {BACKGROUND: Sodalis glossinidius, a maternally transmitted bacterial endosymbiont of tsetse flies (Glossina spp.), uses an acylated homoserine lactone (AHL)-based quorum sensing system to modulate gene expression in accordance with bacterial cell density. The S. glossinidius quorum sensing system relies on the function of two regulatory proteins; SogI (a LuxI homolog) synthesizes a signaling molecule, characterized as N-(3-oxohexanoyl) homoserine lactone (OHHL), and SogR1 (a LuxR homolog) interacts with OHHL to modulate transcription of specific target genes.<br><br>We used a tiling microarray to analyze the S. glossinidius transcriptome in the presence and absence of exogenous OHHL. The major finding is that OHHL increases transcription of a large number of genes that are known to be involved in the oxidative stress response. We also show that the obligate symbiont of the rice weevil, Sitophilus oryzae (SOPE), maintains copies of the quorum sensing regulatory genes that are found in S. glossinidius. Molecular evolutionary analyses indicate that these sequences are evolving under stabilizing selection, consistent with the maintenance of their functions in the SOPE symbiosis. Finally, the expression studies in S. glossinidius also reveal that quorum sensing regulates the expression of a cryptic, degenerate gene (carA) that arose from an ancient deletion in the last common ancestor of S. glossinidius and SOPE.<br><br>CONCLUSIONS/SIGNIFICANCE: This oxidative stress response is likely mandated under conditions of dense intracellular symbiont infection, when intense metabolic activity is expected to generate a heavy oxidative burden. Such conditions are known to arise in the bacteriocytes of grain weevils, which harbor dense intracellular infections of symbiotic bacteria that are closely related to S. glossinidius. The presence of a degenerate carA sequence in S. glossinidius and SOPE indicates the potential for neofunctionalization to occur during the process of genome degeneration.}, }
@article {pmid18952872, year = {2008}, author = {Dougherty, KM and Plague, GR}, title = {Transposable element loads in a bacterial symbiont of weevils are extremely variable.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {24}, pages = {7832-7834}, pmid = {18952872}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; *DNA Transposable Elements ; *Genetic Variation ; Symbiosis ; Weevils/*microbiology/physiology ; }, abstract = {Not only are transposable elements profuse in the bacterial endosymbiont of maize weevils, but we found that their quantities also vary approximately 10-fold among individual weevils. Because multicopy elements can facilitate homologous recombination, this insertion sequence (IS) load variability suggests that these essentially asexual bacteria may exhibit substantial intraspecific genomic variation.}, }
@article {pmid18951917, year = {2009}, author = {Park, M and Kim, MS and Lee, KM and Hwang, SY and Ahn, TI}, title = {Characterization of a cryptic plasmid from an alpha-proteobacterial endosymbiont of Amoeba proteus.}, journal = {Plasmid}, volume = {61}, number = {1}, pages = {78-87}, doi = {10.1016/j.plasmid.2008.09.007}, pmid = {18951917}, issn = {1095-9890}, mesh = {Alphaproteobacteria/*genetics/physiology ; Amino Acid Sequence ; Amoeba/*microbiology ; Animals ; Bacterial Proteins/chemistry/genetics ; Base Sequence ; DNA, Bacterial/genetics ; Molecular Sequence Data ; Open Reading Frames ; Phosphoric Monoester Hydrolases/*genetics/metabolism ; Phylogeny ; Plasmids/*genetics/isolation &amp; purification ; Sequence Alignment ; *Symbiosis ; }, abstract = {A new cryptic plasmid pAP3.9 was discovered in symbiotic alpha-proteobacteria present in the cytoplasm of Amoeba proteus. The plasmid is 3869bp with a GC content of 34.66% and contains replication origins for both double-strand (dso) and single-strand (sso). It has three putative ORFs encoding Mob, Rep and phosphoglycolate phosphatase (PGPase). The pAP3.9 plasmid appears to propagate by the conjugative rolling-circle replication (RCR), since it contains all required factors such as Rep, sso and dso. Mob and Rep showed highest similarities to those of the cryptic plasmid pBMYdx in Bacillus mycoides. The PGPase was homologous to that of Bacillus cereus and formed a clade with those of Bacillus sp. in molecular phylogeny. These results imply that the pAP3.9 plasmid evolved by the passage through Bacillus species. We hypothesize that the plasmid-encoded PGPase may have contributed to the establishment of bacterial symbiosis within the hostile environment of amoeba cytoplasm.}, }
@article {pmid18947926, year = {2008}, author = {Kramer, L and Grandi, G and Leoni, M and Passeri, B and McCall, J and Genchi, C and Mortarino, M and Bazzocchi, C}, title = {Wolbachia and its influence on the pathology and immunology of Dirofilaria immitis infection.}, journal = {Veterinary parasitology}, volume = {158}, number = {3}, pages = {191-195}, doi = {10.1016/j.vetpar.2008.09.014}, pmid = {18947926}, issn = {0304-4017}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Arsenicals/therapeutic use ; Bacterial Outer Membrane Proteins/immunology ; Dirofilaria immitis/*microbiology/pathogenicity ; Dirofilariasis/immunology/microbiology/parasitology/*pathology ; Dog Diseases/immunology/microbiology/parasitology/*pathology ; Dogs ; Doxycycline/therapeutic use ; Female ; Filaricides/*therapeutic use ; Immunohistochemistry/veterinary ; Ivermectin/therapeutic use ; Lung/parasitology/*pathology ; Male ; Severity of Illness Index ; Triazines/therapeutic use ; Wolbachia/drug effects/*immunology ; }, abstract = {Since the definitive identification in 1995 of the bacterial endosymbiont Wolbachia that resides in different tissues of the filarial worm Dirofilaria immitis, there has been increasing interest to understand whether and what role it plays in the pathogenesis of and immune response to heartworm infection. The present study evaluated the effects of treatments on lung pathology in 20 beagle dogs experimentally infected with D. immitis. Dogs in Group 1 were treated with doxycycline (10 mg/kg/day) orally from weeks 0-6, 10-12, 16-18, 22-26, and 28-34. Dogs in Group 2 served as infected, non-treated controls. Dogs in Group 3 were given doxycycline as described for Group 1 combined with weekly oral doses of ivermectin (6 mcg/kg) for 34 weeks and intramuscular (IM) melarsomine (2.5 mg/kg) at week 24, followed by two additional melarsomine injections 24h apart 1 month later. Group 4 received only melarsomine as described for Group 3. Lung lesion criteria, scored by two independent blinded pathologists, included perivascular inflammation and endothelial proliferation. Doxycycline treatment alone had no effect on lesion scores, whereas the combination of doxycycline and ivermectin resulted in less severe perivascular inflammation. All lungs were evaluated for positive immunostaining for the Wolbachia surface protein (WSP). Control dogs showed numerous thrombi, intense perivascular and interstitial inflammation and, occasionally, positive staining for WSP. Interestingly, dogs receiving doxycycline/ivermectin/melarsomine showed significantly less severe arterial lesions and the virtual absence of thrombi.}, }
@article {pmid18947377, year = {2008}, author = {Reynolds, S and Rolff, J}, title = {Immune function keeps endosymbionts under control.}, journal = {Journal of biology}, volume = {7}, number = {8}, pages = {28}, pmid = {18947377}, issn = {1475-4924}, mesh = {Animals ; Bacteria/*genetics/*immunology ; Bacterial Physiological Phenomena ; *Gene Expression Regulation ; Host-Parasite Interactions ; Immune System/*physiology ; Symbiosis/*genetics ; *Weevils/genetics/immunology/microbiology ; Zea mays/parasitology ; }, abstract = {How does an animal host prevent intracellular symbionts getting out of hand? A new paper in BMC Biology provides evidence that the mutualism between a beetle and its bacterial endosymbiont could be mediated through the expression of host immune genes.}, }
@article {pmid18945184, year = {2009}, author = {Sréter-Lancz, Z and Széll, Z and Sréter, T and Márialigeti, K}, title = {Detection of a novel Francisella in Dermacentor reticulatus: a need for careful evaluation of PCR-based identification of Francisella tularensis in Eurasian ticks.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {9}, number = {1}, pages = {123-126}, doi = {10.1089/vbz.2008.0010}, pmid = {18945184}, issn = {1557-7759}, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacterial Proteins/genetics ; Base Sequence ; Dermacentor/*microbiology ; Foxes/parasitology ; Francisella tularensis/classification/genetics/*isolation &amp; purification ; Genotype ; Hungary/epidemiology ; Ixodes/microbiology ; Ixodidae/microbiology ; Lipoproteins/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Tularemia/*epidemiology/transmission ; }, abstract = {Francisella tularensis, the causative agent of tularemia, has been detected in ixodid ticks in some regions of North America, Europe, and Asia. In the present study, 245 Dermacentor reticulatus, 211 Ixodes ricinus, and 194 Haemaphysalis concinna adults from Hungary were tested for the presence of F. tularensis by polymerase chain reaction (PCR) assays based on 16S ribosomal RNA (16S rDNA) and T-cell epitope of a Francisella membrane protein (TUL4). No Francisella-specific amplification products were detected in I. ricinus and H. concinna ticks. Francisella DNA was identified using PCR assays based on 16S rDNA and TUL4 gene in D. reticulatus with similar prevalence (minimum 1.2%) as demonstrated in earlier European and Asian studies detecting F. tularensis in D. reticulatus. However, the 16S rDNA and TUL4 gene sequences of the Francisella-like agent occurring in D. reticulatus differed from the homologous sequences of Francisella spp. deposited in GenBank. Phylogenetic reconstructions showed that the new genotype detected in D. reticulatus was closely related to Francisella-like endosymbionts of North American Dermacentor ticks. Although further studies are needed on the relationship of this bacterium with ticks, the results highlight the need for careful evaluation of PCR-based identification in European and Asian laboratories that screen ixodid ticks for F. tularensis.}, }
@article {pmid18942939, year = {2007}, author = {Sémétey, O and Gatineau, F and Bressan, A and Boudon-Padieu, E}, title = {Characterization of a gamma-3 Proteobacteria Responsible for the Syndrome "Basses Richesses" of Sugar Beet Transmitted by Pentastiridius sp. (Hemiptera, Cixiidae).}, journal = {Phytopathology}, volume = {97}, number = {1}, pages = {72-78}, doi = {10.1094/PHYTO-97-0072}, pmid = {18942939}, issn = {0031-949X}, abstract = {The disease syndrome "basses richesses" (SBR) has affected sugar beet crops in Burgundy (France) since 1991. It mainly is associated with an uncultivable phloem-restricted bacterium-like organism (BLO) called SBR BLO. Transmission tests showed that field-collected Pentastiridius sp. (Hemiptera, Cixiidae) were able to transmit the SBR BLO to sugar beet. In the present work, sequences of a 1,507-bp 16S ribosomal (r)DNA fragment of SBR BLO were amplified from DNA extracts of SBR-affected field sugar beet plants, of field-collected Pentastiridius sp. plant-hoppers, and of Pentastiridiussp.-exposed sugar beet seedlings that expressed SBR symptoms. The sequences showed total identity, confirming the role of SBR BLO in the etiology of SBR and the vector role of Pentastiridius sp. Our surveys on SBR-affected sugar beet plants and Pentastiridius sp. planthoppers collected in different fields and different years suggest that a unique BLO was involved in SBR. Furthermore, comparison of 16S rDNA sequences permitted the identification of the SBR BLO as a new plant-pathogenic gamma-3 proteobacteria different from 'Candidatus Phlomobacter fragariae,' another BLO responsible for marginal chlorosis disease of strawberry in France. Phylogenetic analysis revealed a close relationship between the SBR bacterium and several bacteria described as endosymbionts of hemipteran insects.}, }
@article {pmid18931357, year = {2008}, author = {Lee, SA and Lee, SG and Choi, EJ and Hyun, C}, title = {Prevalence of the endosymbiont Wolbachia in heartworms (Dirofilaria immitis).}, journal = {The Veterinary record}, volume = {163}, number = {16}, pages = {484-486}, doi = {10.1136/vr.163.16.484}, pmid = {18931357}, issn = {0042-4900}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics/*isolation &amp; purification ; DNA, Bacterial/analysis ; DNA, Helminth/analysis ; Dirofilaria immitis/genetics/isolation &amp; purification/*microbiology ; Dirofilariasis/*parasitology ; Dog Diseases/*parasitology ; Dogs ; Female ; Korea ; Male ; Polymerase Chain Reaction ; Prevalence ; *Symbiosis ; Wolbachia/genetics/*isolation &amp; purification/physiology ; }, }
@article {pmid18931144, year = {2008}, author = {Willmund, F and Dorn, KV and Schulz-Raffelt, M and Schroda, M}, title = {The chloroplast DnaJ homolog CDJ1 of Chlamydomonas reinhardtii is part of a multichaperone complex containing HSP70B, CGE1, and HSP90C.}, journal = {Plant physiology}, volume = {148}, number = {4}, pages = {2070-2082}, pmid = {18931144}, issn = {0032-0889}, mesh = {Algal Proteins/chemistry/genetics/*metabolism ; Amino Acid Sequence ; Animals ; Chlamydomonas reinhardtii/genetics/*metabolism ; Chloroplasts/*metabolism ; Dimerization ; HSP40 Heat-Shock Proteins/chemistry/genetics/*metabolism ; HSP70 Heat-Shock Proteins/*metabolism ; HSP90 Heat-Shock Proteins/*metabolism ; Molecular Sequence Data ; Phylogeny ; Plant Proteins ; Protozoan Proteins/*metabolism ; Sequence Alignment ; Zinc Fingers ; }, abstract = {We report on the molecular and biochemical characterization of CDJ1, one of three zinc-finger-containing J-domain proteins encoded by the Chlamydomonas reinhardtii genome. Fractionation experiments indicate that CDJ1 is a plastidic protein. In the chloroplast, CDJ1 was localized to the soluble stroma fraction, but also to thylakoids and to low density membranes. Although the CDJ1 gene was strongly heat shock inducible, CDJ1 protein levels increased only slightly during heat shock. Cellular CDJ1 concentrations were close to those of heat shock protein 70B (HSP70B), the major HSP70 in the Chlamydomonas chloroplast. CDJ1 complemented the temperature-sensitive phenotype of an Escherichia coli mutant lacking its dnaJ gene and interacted with E. coli DnaK, hence classifying it as a bona fide DnaJ protein. In soluble cell extracts, CDJ1 was found to organize into stable dimers and into complexes of high molecular mass. Immunoprecipitation experiments revealed that CDJ1 forms common complexes with plastidic HSP90C, HSP70B, and CGE1. In blue native-polyacrylamide gel electrophoresis, all four (co)chaperones migrated at 40% to 90% higher apparent than calculated molecular masses, indicating that greatest care must be taken when molecular masses of protein complexes are estimated from their migration relative to standard native marker proteins. Immunoprecipitation experiments from size-fractioned soluble cell extracts suggested that HSP90C and HSP70B exist as preformed complex that is joined by CDJ1. In summary, CDJ1 and CGE1 are novel cohort proteins of the chloroplast HSP90-HSP70 multichaperone complex. As HSP70B, CDJ1, and CGE1 are derived from the endosymbiont, whereas HSP90C is of eukaryotic origin, we observe in the chloroplast the interaction of two chaperone systems of distinct evolutionary origin.}, }
@article {pmid18925938, year = {2008}, author = {Anselme, C and Pérez-Brocal, V and Vallier, A and Vincent-Monegat, C and Charif, D and Latorre, A and Moya, A and Heddi, A}, title = {Identification of the weevil immune genes and their expression in the bacteriome tissue.}, journal = {BMC biology}, volume = {6}, number = {}, pages = {43}, pmid = {18925938}, issn = {1741-7007}, mesh = {Alphaproteobacteria/physiology ; Animals ; Antimicrobial Cationic Peptides/genetics ; Carrier Proteins/genetics ; Escherichia coli/physiology ; *Gene Expression Regulation ; Insect Proteins/*genetics ; Intracellular Signaling Peptides and Proteins/genetics ; Larva/immunology/microbiology ; Molecular Sequence Data ; Muramidase/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Weevils/genetics/immunology/microbiology ; }, abstract = {BACKGROUND: Persistent infections with mutualistic intracellular bacteria (endosymbionts) are well represented in insects and are considered to be a driving force in evolution. However, while pathogenic relationships have been well studied over the last decades very little is known about the recognition of the endosymbionts by the host immune system and the mechanism that limits their infection to the bacteria-bearing host tissue (the bacteriome).<br><br>RESULTS: To study bacteriome immune specificity, we first identified immune-relevant genes of the weevil Sitophilus zeamais by using suppressive subtractive hybridization (SSH) and then analyzed their full-length coding sequences obtained by RACE-PCR experiments. We then measured immune gene expression in the bacteriome, and in the aposymbiotic larvae following S. zeamais primary endosymbiont (SZPE) injection into the hemolymph, in order to consider the questions of bacteriome immune specificity and the insect humoral response to symbionts. We show that larval challenge with the endosymbiont results in a significant induction of antibacterial peptide genes, providing evidence that, outside the bacteriome, SZPE are recognized as microbial intruders by the host. In the bacteriome, gene expression analysis shows the overexpression of one antibacterial peptide from the coleoptericin family and, intriguingly, homologs to genes described as immune modulators (that is, PGRP-LB, Tollip) were also shown to be highly expressed in the bacteriome.<br><br>CONCLUSION: The current data provide the first description of immune gene expression in the insect bacteriome. Compared with the insect humoral response to SZPE, the bacteriome expresses few genes among those investigated in this work. This local immune gene expression may help to maintain the endosymbiont in the bacteriome and prevent its invasion into insect tissues. Further investigations of the coleoptericin, the PGRP and the Tollip genes should elucidate the role of the host immune system in the maintenance and regulation of endosymbiosis.}, }
@article {pmid18923393, year = {2008}, author = {Bowler, C and Allen, AE and Badger, JH and Grimwood, J and Jabbari, K and Kuo, A and Maheswari, U and Martens, C and Maumus, F and Otillar, RP and Rayko, E and Salamov, A and Vandepoele, K and Beszteri, B and Gruber, A and Heijde, M and Katinka, M and Mock, T and Valentin, K and Verret, F and Berges, JA and Brownlee, C and Cadoret, JP and Chiovitti, A and Choi, CJ and Coesel, S and De Martino, A and Detter, JC and Durkin, C and Falciatore, A and Fournet, J and Haruta, M and Huysman, MJ and Jenkins, BD and Jiroutova, K and Jorgensen, RE and Joubert, Y and Kaplan, A and Kröger, N and Kroth, PG and La Roche, J and Lindquist, E and Lommer, M and Martin-Jézéquel, V and Lopez, PJ and Lucas, S and Mangogna, M and McGinnis, K and Medlin, LK and Montsant, A and Oudot-Le Secq, MP and Napoli, C and Obornik, M and Parker, MS and Petit, JL and Porcel, BM and Poulsen, N and Robison, M and Rychlewski, L and Rynearson, TA and Schmutz, J and Shapiro, H and Siaut, M and Stanley, M and Sussman, MR and Taylor, AR and Vardi, A and von Dassow, P and Vyverman, W and Willis, A and Wyrwicz, LS and Rokhsar, DS and Weissenbach, J and Armbrust, EV and Green, BR and Van de Peer, Y and Grigoriev, IV}, title = {The Phaeodactylum genome reveals the evolutionary history of diatom genomes.}, journal = {Nature}, volume = {456}, number = {7219}, pages = {239-244}, doi = {10.1038/nature07410}, pmid = {18923393}, issn = {1476-4687}, mesh = {DNA, Algal/analysis ; Diatoms/*genetics ; *Evolution, Molecular ; Genes, Bacterial/genetics ; Genome/*genetics ; Molecular Sequence Data ; Protein Structure, Tertiary ; Sequence Homology, Amino Acid ; Signal Transduction ; }, abstract = {Diatoms are photosynthetic secondary endosymbionts found throughout marine and freshwater environments, and are believed to be responsible for around one-fifth of the primary productivity on Earth. The genome sequence of the marine centric diatom Thalassiosira pseudonana was recently reported, revealing a wealth of information about diatom biology. Here we report the complete genome sequence of the pennate diatom Phaeodactylum tricornutum and compare it with that of T. pseudonana to clarify evolutionary origins, functional significance and ubiquity of these features throughout diatoms. In spite of the fact that the pennate and centric lineages have only been diverging for 90 million years, their genome structures are dramatically different and a substantial fraction of genes (approximately 40%) are not shared by these representatives of the two lineages. Analysis of molecular divergence compared with yeasts and metazoans reveals rapid rates of gene diversification in diatoms. Contributing factors include selective gene family expansions, differential losses and gains of genes and introns, and differential mobilization of transposable elements. Most significantly, we document the presence of hundreds of genes from bacteria. More than 300 of these gene transfers are found in both diatoms, attesting to their ancient origins, and many are likely to provide novel possibilities for metabolite management and for perception of environmental signals. These findings go a long way towards explaining the incredible diversity and success of the diatoms in contemporary oceans.}, }
@article {pmid18845550, year = {2009}, author = {Hu, J and Blanchard, JL}, title = {Environmental sequence data from the Sargasso Sea reveal that the characteristics of genome reduction in Prochlorococcus are not a harbinger for an escalation in genetic drift.}, journal = {Molecular biology and evolution}, volume = {26}, number = {1}, pages = {5-13}, doi = {10.1093/molbev/msn217}, pmid = {18845550}, issn = {1537-1719}, mesh = {*Evolution, Molecular ; Genetic Drift ; Genomics ; Prochlorococcus/classification/*genetics/physiology ; Seawater/*microbiology ; Synechococcus/classification/genetics ; }, abstract = {The marine cyanobacterium Prochlorococcus MED4 has the smallest sequenced genome of any photosynthetic organism. Prochlorococcus MED4 shares many genomic characteristics with chloroplasts and bacterial endosymbionts, including a reduced coding capacity, missing DNA repair genes, a minimal transcriptional regulatory network, a marked AT% bias, and an accelerated rate of amino acid changes. In chloroplasts and endosymbionts, these molecular phenotypes appear to be symptomatic of a relative increase in genetic drift due to restrictions on effective population size in the host environment. As a free-living bacterium, Prochlorococcus MED4 is not known to be subject to similar ecological constraints. To test whether the high-light-adapted Prochlorococcus MED4 is experiencing a reduction in selection efficiency resulting from genetic drift, we examine two data sets, namely, the environmental genome shotgun sequencing data from the Sargasso Sea and a set of cyanobacterial genome sequences. After integrating these data sets, we compare the evolutionary profile of a high-light Prochlorococcus group to that of a group of Synechococcus (a closely related group of marine cyanobacteria) that does not exhibit a similar small-genome syndrome. The average pairwise dN/dS ratios in the high-light-adapted Prochlorococcus group are significantly lower than those in the Synechococcus group, leading us to reject the hypothesis that the Prochlorococcus group is currently experiencing higher levels of genetic drift.}, }
@article {pmid18818770, year = {2008}, author = {Braquart-Varnier, C and Lachat, M and Herbinière, J and Johnson, M and Caubet, Y and Bouchon, D and Sicard, M}, title = {Wolbachia mediate variation of host immunocompetence.}, journal = {PloS one}, volume = {3}, number = {9}, pages = {e3286}, pmid = {18818770}, issn = {1932-6203}, mesh = {Animals ; Antibody Formation ; Arthropods/*microbiology/physiology ; Cell Lineage ; DNA, Mitochondrial/metabolism ; Female ; Hemocytes/metabolism ; Hemolymph/metabolism ; Immune System ; Immunocompetence/*genetics ; Models, Biological ; Phenotype ; Symbiosis/genetics ; Wolbachia/*genetics/*physiology ; }, abstract = {BACKGROUND: After decades during which endosymbionts were considered as silent in their hosts, in particular concerning the immune system, recent studies have revealed the contrary. In the present paper, we addressed the effect of Wolbachia, the most prevalent endosymbiont in arthropods, on host immunocompetence. To this end, we chose the A. vulgare-Wolbachia symbiosis as a model system because it leads to compare consequences of two Wolbachia strains (wVulC and wVulM) on hosts from the same population. Moreover, A. vulgare is the only host-species in which Wolbachia have been directly observed within haemocytes which are responsible for both humoral and cellular immune responses.<br><br>We sampled gravid females from the same population that were either asymbiotic, infected with wVulC, or infected with wVulM. The offspring from these females were tested and it was revealed that individuals harbouring wVulC exhibited: (i) lower haemocyte densities, (ii) more intense septicaemia in their haemolymph and (iii) a reduced lifespan as compared to individuals habouring wVulM or asymbiotic ones. Therefore, individuals in this population of A. vulgare appeared to suffer more from wVulC than from wVulM. Symbiotic titer and location in the haemocytes did not differ for the two Wolbachia strains showing that these two parameters were not responsible for differences observed in their extended phenotypes in A. vulgare.<br><br>CONCLUSION/SIGNIFICANCE: The two Wolbachia strains infecting A. vulgare in the same population induced variation in immunocompetence and survival of their hosts. Such variation should highly influence the dynamics of this host-symbiont system. We propose in accordance with previous population genetic works, that wVulM is a local strain that has attenuated its virulence through a long term adaptation process towards local A. vulgare genotypes whereas wVulC, which is a widespread and invasive strain, is not locally adapted.}, }
@article {pmid18815381, year = {2008}, author = {Tamas, I and Wernegreen, JJ and Nystedt, B and Kauppinen, SN and Darby, AC and Gomez-Valero, L and Lundin, D and Poole, AM and Andersson, SG}, title = {Endosymbiont gene functions impaired and rescued by polymerase infidelity at poly(A) tracts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {39}, pages = {14934-14939}, pmid = {18815381}, issn = {1091-6490}, mesh = {Animals ; Aphids/embryology/enzymology/microbiology ; Base Sequence ; Buchnera/*genetics/physiology ; Cell Wall/genetics ; Computer Simulation ; DNA-Directed RNA Polymerases/*metabolism ; Embryo, Nonmammalian/embryology/enzymology/microbiology ; *Evolution, Molecular ; Frameshift Mutation ; Gene Expression ; Genome, Bacterial ; Histidine/biosynthesis ; Molecular Sequence Data ; Open Reading Frames ; Peptide Synthases/biosynthesis/genetics ; Polyadenylation/*genetics ; RNA, Messenger/*biosynthesis/genetics ; Symbiosis/*genetics ; Transcription, Genetic ; }, abstract = {Among host-dependent bacteria that have evolved by extreme reductive genome evolution, long-term bacterial endosymbionts of insects have the smallest (160-790 kb) and most A + T-rich (>70%) bacterial genomes known to date. These genomes are riddled with poly(A) tracts, and 5-50% of genes contain tracts of 10 As or more. Here, we demonstrate transcriptional slippage at poly(A) tracts within genes of Buchnera aphidicola associated with aphids and Blochmannia pennsylvanicus associated with ants. Several tracts contain single frameshift deletions; these apparent pseudogenes showed patterns of constraint consistent with purifying selection on the encoded proteins. Transcriptional slippage yielded a heterogeneous population of transcripts with variable numbers of As in the tract. Across several frameshifted genes, including B. aphidicola cell wall biosynthesis genes and a B. pennsylvanicus histidine biosynthesis gene, 12-50% of transcripts contained corrected reading frames that could potentially yield full-length proteins. In situ immunostaining confirmed the production of the cell wall biosynthetic enzyme UDP-N-acetylmuramyl pentapeptide synthase encoded by the frameshifted murF gene. Simulation studies indicated an overrepresentation of poly(A) tracts in endosymbiont genomes relative to other A + T-rich bacterial genomes. Polymerase infidelity at poly(A) tracts rescues the functionality of genes with frameshift mutations and, conversely, reduces the efficiency of expression for in-frame genes carrying poly(A) regions. These features of homopolymeric tracts could be exploited to manipulate gene expression in small synthetic genomes.}, }
@article {pmid18812496, year = {2008}, author = {Glynn, JM and Froehlich, JE and Osteryoung, KW}, title = {Arabidopsis ARC6 coordinates the division machineries of the inner and outer chloroplast membranes through interaction with PDV2 in the intermembrane space.}, journal = {The Plant cell}, volume = {20}, number = {9}, pages = {2460-2470}, pmid = {18812496}, issn = {1040-4651}, mesh = {Amino Acid Sequence ; Arabidopsis/genetics/*metabolism ; Arabidopsis Proteins/classification/genetics/*metabolism ; Chloroplasts/*metabolism ; Immunoblotting ; Intracellular Membranes/*metabolism ; Microscopy, Fluorescence ; Models, Biological ; Molecular Sequence Data ; Phylogeny ; Protein Binding ; Sequence Homology, Amino Acid ; Two-Hybrid System Techniques ; }, abstract = {Chloroplasts arose from a free-living cyanobacterial endosymbiont and divide by binary fission. Division involves the assembly and constriction of the endosymbiont-derived, tubulin-like FtsZ ring on the stromal surface of the inner envelope membrane and the host-derived, dynamin-like ARC5 ring on the cytosolic surface of the outer envelope membrane. Despite the identification of many proteins required for plastid division, the factors coordinating the internal and external division machineries are unknown. Here, we provide evidence that this coordination is mediated in Arabidopsis thaliana by an interaction between ARC6, an FtsZ assembly factor spanning the inner envelope membrane, and PDV2, an ARC5 recruitment factor spanning the outer envelope membrane. ARC6 and PDV2 interact via their C-terminal domains in the intermembrane space, consistent with their in vivo topologies. ARC6 acts upstream of PDV2 to localize PDV2 (and hence ARC5) to the division site. We present a model whereby ARC6 relays information on stromal FtsZ ring positioning through PDV2 to the chloroplast surface to specify the site of ARC5 recruitment. Because orthologs of ARC6 occur in land plants, green algae, and cyanobacteria but PDV2 occurs only in land plants, the connection between ARC6 and PDV2 represents the evolution of a plant-specific adaptation to coordinate the assembly and activity of the endosymbiont- and host-derived plastid division components.}, }
@article {pmid18809930, year = {2008}, author = {Miyagishima, SY and Kuwayama, H and Urushihara, H and Nakanishi, H}, title = {Evolutionary linkage between eukaryotic cytokinesis and chloroplast division by dynamin proteins.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {39}, pages = {15202-15207}, pmid = {18809930}, issn = {1091-6490}, mesh = {Amoeba/physiology ; Animals ; Arabidopsis/cytology/enzymology/physiology ; Chloroplasts/enzymology/*physiology ; *Cytokinesis ; Dynamins/*classification/genetics/physiology ; *Evolution, Molecular ; Phylogeny ; Plant Proteins/*classification/genetics/physiology ; Protozoan Proteins/*classification/genetics/physiology ; }, abstract = {Chloroplasts have evolved from a cyanobacterial endosymbiont and been retained for more than 1 billion years by coordinated chloroplast division in multiplying eukaryotic cells. Chloroplast division is performed by ring structures at the division site, encompassing both the inside and the outside of the two envelopes. A part of the division machinery is derived from the cyanobacterial cytokinetic activity based on the FtsZ protein. In contrast, other parts of the division machinery involve proteins specific to eukaryotes, including a member of the dynamin family. Each member of the dynamin family is involved in the division or fusion of a distinct eukaryotic membrane system. To gain insight into the kind of ancestral dynamin protein and eukaryotic membrane activity that evolved to regulate chloroplast division, we investigated the functions of the dynamin proteins that are most closely related to chloroplast division proteins. These proteins in the amoeba Dictyostelium discoideum and Arabidopsis thaliana localize at the sites of cell division, where they are involved in cytokinesis. Our results suggest that the dynamin for chloroplast division is derived from that involved in eukaryotic cytokinesis. Therefore, the chloroplast division machinery is a mixture of bacterial and eukaryotic cytokinesis components, with the latter a key factor in the synchronization of endosymbiotic cell division with host cell division, thus helping to establish the permanent endosymbiotic relationship.}, }
@article {pmid18801163, year = {2008}, author = {Foster, JM and Kumar, S and Ford, L and Johnston, KL and Ben, R and Graeff-Teixeira, C and Taylor, MJ}, title = {Absence of Wolbachia endobacteria in the non-filariid nematodes Angiostrongylus cantonensis and A. costaricensis.}, journal = {Parasites &amp; vectors}, volume = {1}, number = {1}, pages = {31}, pmid = {18801163}, issn = {1756-3305}, abstract = {The majority of filarial nematodes harbour Wolbachia endobacteria, including the major pathogenic species in humans, Onchocerca volvulus, Brugia malayi and Wuchereria bancrofti. These obligate endosymbionts have never been demonstrated unequivocally in any non-filariid nematode. However, a recent report described the detection by PCR of Wolbachia in the metastrongylid nematode, Angiostrongylus cantonensis (rat lungworm), a leading cause of eosinophilic meningitis in humans. To address the intriguing possibility of Wolbachia infection in nematode species distinct from the Family Onchocercidae, we used both PCR and immunohistochemistry to screen samples of A. cantonensis and A. costaricensis for the presence of this endosymbiont. We were unable to detect Wolbachia in either species using these methodologies. In addition, bioinformatic and phylogenetic analyses of the Wolbachia gene sequences reported previously from A. cantonensis indicate that they most likely result from contamination with DNA from arthropods and filarial nematodes. This study demonstrates the need for caution in relying solely on PCR for identification of new endosymbiont strains from invertebrate DNA samples.}, }
@article {pmid18799712, year = {2008}, author = {Frommolt, R and Werner, S and Paulsen, H and Goss, R and Wilhelm, C and Zauner, S and Maier, UG and Grossman, AR and Bhattacharya, D and Lohr, M}, title = {Ancient recruitment by chromists of green algal genes encoding enzymes for carotenoid biosynthesis.}, journal = {Molecular biology and evolution}, volume = {25}, number = {12}, pages = {2653-2667}, doi = {10.1093/molbev/msn206}, pmid = {18799712}, issn = {1537-1719}, mesh = {*Biological Evolution ; Carotenoids/*biosynthesis ; Chlorophyta/enzymology/*genetics ; Eukaryota/classification/*genetics ; Phylogeny ; Plastids/genetics ; }, abstract = {Chromist algae (stramenopiles, cryptophytes, and haptophytes) are major contributors to marine primary productivity. These eukaryotes acquired their plastid via secondary endosymbiosis, whereby an early-diverging red alga was engulfed by a protist and the plastid was retained and its associated nuclear-encoded genes were transferred to the host genome. Current data suggest, however, that chromists are paraphyletic; therefore, it remains unclear whether their plastids trace back to a single secondary endosymbiosis or, alternatively, this organelle has resulted from multiple independent events in the different chromist lineages. Both scenarios, however, predict that plastid-targeted, nucleus-encoded chromist proteins should be most closely related to their red algal homologs. Here we analyzed the biosynthetic pathway of carotenoids that are essential components of all photosynthetic eukaryotes and find a mosaic evolutionary origin of these enzymes in chromists. Surprisingly, about one-third (5/16) of the proteins are most closely related to green algal homologs with three branching within or sister to the early-diverging Prasinophyceae. This phylogenetic association is corroborated by shared diagnostic indels and the syntenic arrangement of a specific gene pair involved in the photoprotective xanthophyll cycle. The combined data suggest that the prasinophyte genes may have been acquired before the ancient split of stramenopiles, haptophytes, cryptophytes, and putatively also dinoflagellates. The latter point is supported by the observed monophyly of alveolates and stramenopiles in most molecular trees. One possible explanation for our results is that the green genes are remnants of a cryptic endosymbiosis that occurred early in chromalveolate evolution; that is, prior to the postulated split of stramenopiles, alveolates, haptophytes, and cryptophytes. The subsequent red algal capture would have led to the loss or replacement of most green genes via intracellular gene transfer from the new endosymbiont. We argue that the prasinophyte genes were retained because they enhance photosynthetic performance in chromalveolates, thus extending the niches available to these organisms. The alternate explanation of green gene origin via serial endosymbiotic or horizontal gene transfers is also plausible, but the latter would require the independent origins of the same five genes in some or all the different chromalveolate lineages.}, }
@article {pmid18794912, year = {2008}, author = {Werren, JH and Baldo, L and Clark, ME}, title = {Wolbachia: master manipulators of invertebrate biology.}, journal = {Nature reviews. Microbiology}, volume = {6}, number = {10}, pages = {741-751}, doi = {10.1038/nrmicro1969}, pmid = {18794912}, issn = {1740-1534}, mesh = {Animals ; Arthropods/microbiology/*physiology ; Bacterial Proteins/genetics ; Host-Parasite Interactions/genetics ; Nematoda/*microbiology/*physiology ; Symbiosis/genetics/*physiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia are common intracellular bacteria that are found in arthropods and nematodes. These alphaproteobacteria endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, including the induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-egg incompatibility. They can also move horizontally across species boundaries, resulting in a widespread and global distribution in diverse invertebrate hosts. Here, we review the basic biology of Wolbachia, with emphasis on recent advances in our understanding of these fascinating endosymbionts.}, }
@article {pmid18791000, year = {2008}, author = {Degnan, PH and Moran, NA}, title = {Diverse phage-encoded toxins in a protective insect endosymbiont.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {21}, pages = {6782-6791}, pmid = {18791000}, issn = {1098-5336}, mesh = {Animals ; Aphids/*microbiology ; Bacterial Toxins/biosynthesis/*genetics ; Bacteriophages/*genetics ; DNA, Viral/genetics ; Enterobacteriaceae/*virology ; Gene Order ; Gene Rearrangement ; Molecular Sequence Data ; Phylogeny ; Recombination, Genetic ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Synteny ; Viral Proteins/biosynthesis/*genetics ; Wasps/drug effects ; }, abstract = {The lysogenic bacteriophage APSE infects "Candidatus Hamiltonella defensa," a facultative endosymbiont of aphids and other sap-feeding insects. This endosymbiont has established a beneficial association with aphids, increasing survivorship following attack by parasitoid wasps. Although APSE and "Ca. Hamiltonella defensa" are effectively maternally transmitted between aphid generations, they can also be horizontally transferred among insect hosts, which results in genetically distinct "Ca. Hamiltonella defensa" strains infecting the same aphid species and sporadic distributions of both APSE and "Ca. Hamiltonella defensa" among hosts. Aphids infected only with "Ca. Hamiltonella defensa" have significantly less protection than those infected with both "Ca. Hamiltonella defensa" and APSE. This protection has been proposed to be connected to eukaryote-targeted toxins previously discovered in the genomes of two characterized APSE strains. In this study, we have sequenced partial genomes from seven additional APSE strains to address the evolution and extent of toxin variation in this phage. The APSE lysis region has been a hot spot for nonhomologous recombination of novel virulence cassettes. We identified four new toxins from three protein families, Shiga-like toxin, cytolethal distending toxin, and YD-repeat toxins. These recombination events have also resulted in reassortment of the downstream lysozyme and holin genes. Analysis of the conserved APSE genes flanking the variable toxin cassettes reveals a close phylogenetic association with phage sequences from two other facultative endosymbionts of insects. Thus, phage may act as a conduit for ongoing gene exchange among heritable endosymbionts.}, }
@article {pmid18772939, year = {2008}, author = {Graham, RI and Zahner, V and Lucarotti, CJ}, title = {An intracellular symbiont and other microbiota associated with field-collected populations of sawflies (Hymenoptera: Symphyta).}, journal = {Canadian journal of microbiology}, volume = {54}, number = {9}, pages = {758-768}, doi = {10.1139/w08-067}, pmid = {18772939}, issn = {0008-4166}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; *Bacterial Physiological Phenomena ; Bacteriophages/genetics/*isolation &amp; purification ; Canada ; Hymenoptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Restriction Fragment Length ; *Symbiosis ; Wolbachia/genetics/isolation &amp; purification/physiology/virology ; }, abstract = {Six species of sawfly (Hymenoptera: Symphyta) from four taxonomic families (Agridae, Diprionidae, Pamphiliidae, and Tenthredinidae) were collected from locations across Canada and surveyed for their associated microbiota. Total DNA was extracted from individual insects, and polymerase chain reaction (PCR) was used to amplify the conserved 16S rRNA gene from microbiota. Denaturing gradient gel electrophoresis (DGGE) and restriction fragment length polymorphism (RFLP) were undertaken to separate bacterial clones associated with the host insect. Sequencing of the PCR-DGGE and PCR--RFLP products revealed a dominance of alpha- and gamma-Proteobacteria, with most sequences showing high similarity to bacteria previously identified from other insect species and environmental samples. Additionally, a strain of the bacterial endosymbiont Wolbachia and a Wolbachia bacteriophage were identified from the mountain ash sawfly (Pristiphora geniculata).}, }
@article {pmid18764948, year = {2008}, author = {Bonte, D and Hovestadt, T and Poethke, HJ}, title = {Male-killing endosymbionts: influence of environmental conditions on persistence of host metapopulation.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {243}, pmid = {18764948}, issn = {1471-2148}, mesh = {Animals ; Arthropods/microbiology ; Bacterial Physiological Phenomena ; Biological Evolution ; Computer Simulation ; *Environment ; Extinction, Biological ; Female ; Host-Pathogen Interactions/*physiology ; Male ; Models, Biological ; Population Dynamics ; *Sex Ratio ; *Symbiosis ; }, abstract = {BACKGROUND: Male killing endosymbionts manipulate their arthropod host reproduction by only allowing female embryos to develop into infected females and killing all male offspring. Because of the reproductive manipulation, we expect them to have an effect on the evolution of host dispersal rates. In addition, male killing endosymbionts are expected to approach fixation when fitness of infected individuals is larger than that of uninfected ones and when transmission from mother to offspring is nearly perfect. They then vanish as the host population crashes. High observed infection rates and among-population variation in natural systems can consequently not be explained if defense mechanisms are absent and when transmission efficiency is perfect.<br><br>RESULTS: By simulating the host-endosymbiont dynamics in an individual-based metapopulation model we show that male killing endosymbionts increase host dispersal rates. No fitness compensations were built into the model for male killing endosymbionts, but they spread as a group beneficial trait. Host and parasite populations face extinction under panmictic conditions, i.e. conditions that favor the evolution of high dispersal in hosts. On the other hand, deterministic 'curing' (only parasite goes extinct) can occur under conditions of low dispersal, e.g. under low environmental stochasticity and high dispersal mortality. However, high and stable infection rates can be maintained in metapopulations over a considerable spectrum of conditions favoring intermediate levels of dispersal in the host.<br><br>CONCLUSION: Male killing endosymbionts without explicit fitness compensation spread as a group selected trait into a metapopulation. Emergent feedbacks through increased evolutionary stable dispersal rates provide an alternative explanation for both, the high male-killing endosymbiont infection rates and the high among-population variation in local infection rates reported for some natural systems.}, }
@article {pmid18758845, year = {2009}, author = {Gibson, CM and Hunter, MS}, title = {Inherited fungal and bacterial endosymbionts of a parasitic wasp and its cockroach host.}, journal = {Microbial ecology}, volume = {57}, number = {3}, pages = {542-549}, pmid = {18758845}, issn = {1432-184X}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Bayes Theorem ; *Biological Evolution ; Cockroaches/*microbiology/parasitology ; DNA, Bacterial/genetics ; DNA, Fungal/genetics ; Fungi/classification/*genetics/isolation &amp; purification ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; Wasps/*microbiology ; }, abstract = {Bacterial endosymbionts of insects are increasingly being recognized as common, diverse, and integral to the biology of their hosts. Inherited fungal symbionts have been largely overlooked, however, even though insect guts appear to be a key habitat for an incredible array of fungal diversity. Like bacteria, fungal symbionts also likely play important roles in the ecology and evolution of their insect associates. The objective of this study was to lay the foundations for understanding the roles of the vertically transmitted fungal and bacterial associates of both the brownbanded cockroach, Supella longipalpa, and its parasitic wasp, Comperia merceti. We used culture-dependent and culture-independent molecular methods and phylogenetic analyses in order to identify the symbionts. Two fungal associates of brownbanded cockroaches were found. To our knowledge, this is the first record of vertically transmitted fungal symbionts in the order Blattaria. The wasp was found to house a close relative of one of the cockroach fungi but no bacterial symbionts. Finally, the brownbanded cockroaches also harbored three lineages of bacterial symbionts: Blattabacterium and two lineages of Wolbachia, indicating the number of vertically transmitted symbionts in this insect may be as many as five.}, }
@article {pmid18755670, year = {2008}, author = {Jansen, VA and Turelli, M and Godfray, HC}, title = {Stochastic spread of Wolbachia.}, journal = {Proceedings. Biological sciences}, volume = {275}, number = {1652}, pages = {2769-2776}, pmid = {18755670}, issn = {0962-8452}, mesh = {Animals ; Female ; *Genetics, Population ; Insecta/*microbiology ; *Models, Biological ; Population Dynamics ; *Stochastic Processes ; Wolbachia/*growth &amp; development ; }, abstract = {Wolbachia are very common, maternally transmitted endosymbionts of insects. They often spread by a mechanism termed cytoplasmic incompatibility (CI) that involves reduced egg hatch when Wolbachia-free ova are fertilized by sperm from Wolbachia-infected males. Because the progeny of Wolbachia-infected females generally do not suffer CI-induced mortality, infected females are often at a reproductive advantage in polymorphic populations. Deterministic models show that Wolbachia that impose no costs on their hosts and have perfect maternal transmission will spread from arbitrarily low frequencies (though initially very slowly); otherwise, there will be a threshold frequency below which Wolbachia frequencies decline to extinction and above which they increase to fixation or a high stable equilibrium. Stochastic theory was used to calculate the probability of fixation in populations of different size for arbitrary current frequencies of Wolbachia, with special attention paid to the case of spread after the arrival of a single infected female. Exact results are given based on a Moran process that assumes a specific demographic model, and approximate results are obtained using the more general Wright-Fisher theory. A new analytical approximation for the probability of fixation is derived, which performs well for small population sizes. The significance of stochastic effects in the natural spread of Wolbachia and their relevance to the use of Wolbachia as a drive mechanism in vector and pest management are discussed.}, }
@article {pmid18717746, year = {2008}, author = {Jaenike, J and Dyer, KA}, title = {No resistance to male-killing Wolbachia after thousands of years of infection.}, journal = {Journal of evolutionary biology}, volume = {21}, number = {6}, pages = {1570-1577}, doi = {10.1111/j.1420-9101.2008.01607.x}, pmid = {18717746}, issn = {1420-9101}, support = {EF-0328363//PHS HHS/United States ; }, mesh = {Animals ; Drosophila/*genetics/*microbiology ; Electron Transport Complex IV/genetics ; Female ; Genetic Variation ; Host-Pathogen Interactions/physiology ; Male ; Sex Ratio ; Wolbachia/*physiology ; }, abstract = {Maternally transmitted male-killing endosymbionts can exert strong and relentless selection pressure on their hosts to evolve resistance to these infections. Surveys of current infection prevalence and mtDNA diversity indicate that Drosophila innubila is and has been infected with male-killing Wolbachia at moderate frequencies for extended evolutionary periods. Here, we use coalescent simulations to infer the minimum age of the Wolbachia infection in this species, and estimate that the infection is at least 15,000 and perhaps over 700,000 years old. We also surveyed this species for genetic variation for resistance to the male-killing effects of infection. Our surveys revealed no evidence for any resistance polymorphism, such that all flies are completely susceptible to male killing. Given the general assumption that Drosophila can be selected for anything, the lack of resistance, despite thousands of years of strong selection, is an apparent evolutionary conundrum. We hypothesize that resistance requires a mutation of major effect that acts early in development, and that the adverse pleiotropic consequences of such mutations in both infected and uninfected individuals may exceed the possible benefit to infected flies.}, }
@article {pmid18713719, year = {2008}, author = {Adachi-Hagimori, T and Miura, K and Stouthamer, R}, title = {A new cytogenetic mechanism for bacterial endosymbiont-induced parthenogenesis in Hymenoptera.}, journal = {Proceedings. Biological sciences}, volume = {275}, number = {1652}, pages = {2667-2673}, pmid = {18713719}, issn = {0962-8452}, mesh = {Animals ; Bacteroidetes ; Base Sequence ; Cytogenetic Analysis ; DNA Primers/genetics ; Hymenoptera/*microbiology/*physiology ; Meiosis/*physiology ; Microsatellite Repeats/genetics ; Molecular Sequence Data ; Parthenogenesis/*physiology ; Rickettsia ; Symbiosis/*physiology ; Wolbachia ; }, abstract = {Vertically transmitted endosymbiotic bacteria, such as Wolbachia, Cardinium and Rickettsia, modify host reproduction in several ways to facilitate their own spread. One such modification results in parthenogenesis induction, where males, which are unable to transmit the bacteria, are not produced. In Hymenoptera, the mechanism of diploidization due to Wolbachia infection, known as gamete duplication, is a post-meiotic modification. During gamete duplication, the meiotic mechanism is normal, but in the first mitosis the anaphase is aborted. The two haploid sets of chromosomes do not separate and thus result in a single nucleus containing two identical sets of haploid chromosomes. Here, we outline an alternative cytogenetic mechanism for bacterial endosymbiont-induced parthenogenesis in Hymenoptera. During female gamete formation in Rickettsia-infected Neochrysocharis formosa (Westwood) parasitoids, meiotic cells undergo only a single equational division followed by the expulsion of a single polar body. This absence of meiotic recombination and reduction corresponds well with a non-segregation pattern in the offspring of heterozygous females. We conclude that diploidy in N. formosa is maintained through a functionally apomictic cloning mechanism that differs entirely from the mechanism induced by Wolbachia.}, }
@article {pmid18707616, year = {2008}, author = {Lösekann, T and Robador, A and Niemann, H and Knittel, K and Boetius, A and Dubilier, N}, title = {Endosymbioses between bacteria and deep-sea siboglinid tubeworms from an Arctic Cold Seep (Haakon Mosby Mud Volcano, Barents Sea).}, journal = {Environmental microbiology}, volume = {10}, number = {12}, pages = {3237-3254}, doi = {10.1111/j.1462-2920.2008.01712.x}, pmid = {18707616}, issn = {1462-2920}, mesh = {Animals ; Arctic Regions ; Bacteria/*classification/*isolation &amp; purification ; Bacterial Physiological Phenomena ; DNA, Bacterial/chemistry/genetics ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genes, rRNA ; Helminths/*microbiology/physiology ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; *Seawater ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Siboglinid tubeworms do not have a mouth or gut and live in obligate associations with bacterial endosymbionts. Little is currently known about the phylogeny of frenulate and moniliferan siboglinids and their symbionts. In this study, we investigated the symbioses of two co-occurring siboglinid species from a methane emitting mud volcano in the Arctic Ocean (Haakon Mosby Mud Volcano, HMMV): Oligobrachia haakonmosbiensis (Frenulata) and Sclerolinum contortum (Monilifera). Comparative sequence analysis of the host-specific 18S and the symbiont-specific 16S rRNA genes of S. contortum showed that the close phylogenetic relationship of this host to vestimentiferan siboglinids was mirrored in the close relationship of its symbionts to the sulfur-oxidizing gammaproteobacterial symbionts of vestimentiferans. A similar congruence between host and symbiont phylogeny was observed in O. haakonmosbiensis: both this host and its symbionts were most closely related to the frenulate siboglinid O. mashikoi and its gammaproteobacterial symbiont. The symbiont sequences from O. haakonmosbiensis and O. mashikoi formed a clade unaffiliated with known methane- or sulfur-oxidizing bacteria. Fluorescence in situ hybridization indicated that the dominant bacterial phylotypes originated from endosymbionts residing inside the host trophosome. In both S. contortum and O. haakonmosbiensis, characteristic genes for autotrophy (cbbLM) and sulfur oxidation (aprA) were present, while genes diagnostic for methanotrophy were not detected. The molecular data suggest that both HMMV tubeworm species harbour chemoautotrophic sulfur-oxidizing symbionts. In S. contortum, average stable carbon isotope values of fatty acids and cholesterol of -43 per thousand were highly negative for a sulfur oxidizing symbiosis, but can be explained by a (13)C-depleted CO(2) source at HMMV. In O. haakonmosbiensis, stable carbon isotope values of fatty acids and cholesterol of -70 per thousand are difficult to reconcile with our current knowledge of isotope signatures for chemoautotrophic processes.}, }
@article {pmid18694335, year = {2008}, author = {Ibrahim, AS and Gebremariam, T and Liu, M and Chamilos, G and Kontoyiannis, D and Mink, R and Kwon-Chung, KJ and Fu, Y and Skory, CD and Edwards, JE and Spellberg, B}, title = {Bacterial endosymbiosis is widely present among zygomycetes but does not contribute to the pathogenesis of mucormycosis.}, journal = {The Journal of infectious diseases}, volume = {198}, number = {7}, pages = {1083-1090}, pmid = {18694335}, issn = {0022-1899}, support = {K08 AI060641/AI/NIAID NIH HHS/United States ; R01 AI063503/AI/NIAID NIH HHS/United States ; R21 AI064716/AI/NIAID NIH HHS/United States ; Z01 AI000657-16/ImNIH/Intramural NIH HHS/United States ; }, mesh = {Animals ; Burkholderia/*growth &amp; development ; Endothelial Cells/physiology ; Humans ; Macrolides/metabolism ; Male ; Mice ; Mice, Inbred BALB C ; Mucor/*growth &amp; development ; Mucormycosis/*etiology ; Rhizopus/*growth &amp; development ; *Symbiosis ; }, abstract = {Environmental isolates of the fungus Rhizopus have been shown to harbor a bacterial endosymbiont (Burkholderia) that produces rhixozin, a plant mycotoxin. We sought to define the role of rhizoxin production by endosymbionts in the pathogenesis of mucormycosis. Endosymbiotic bacteria were identified by polymerase chain reaction in 15 (54%) of 28 clinical isolates of Zygomycetes, with 33% of the bacterial strains showing 87% identity to Burkholderia 16S rDNA. The presence of rhizoxin in myclial extracts from fungi harboring bacteria was confirmed by high-performance liquid chromatography analysis. However, fungal strains with or without endosymbionts did not differ in their ability to cause endothelial cell injury in vitro, nor did antibiotic-mediated eradication of endosymbionts and rhizoxin production decrease the virulence of fungal strains in mice or flies. In summary, although bacterial endosymbiosis is widely detected in clinical isolates of Zygomycetes, including Rhizopus oryzae strains, we found no evidence that bacterial endosymbionts and rhizoxin contribute to the pathogenesis of mucormycosis in the models studied.}, }
@article {pmid18689508, year = {2008}, author = {Sassera, D and Lo, N and Bouman, EA and Epis, S and Mortarino, M and Bandi, C}, title = {"Candidatus Midichloria" endosymbionts bloom after the blood meal of the host, the hard tick Ixodes ricinus.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {19}, pages = {6138-6140}, pmid = {18689508}, issn = {1098-5336}, mesh = {Alphaproteobacteria/genetics/growth &amp; development/*physiology ; Animals ; Colony Count, Microbial/methods ; DNA, Bacterial/genetics ; Female ; Genes, Bacterial ; Ixodes/*microbiology/physiology ; Male ; Polymerase Chain Reaction/methods ; *Symbiosis ; }, abstract = {"Candidatus Midichloria mitochondrii," an intracellular symbiont of the tick Ixodes ricinus, is the only described organism able to invade the mitochondria of any multicellular organism. We used quantitative PCR to examine cycles of bacterial growth and death throughout the host's development and found that they correspond with the phases of engorgement and molt, respectively.}, }
@article {pmid18689507, year = {2008}, author = {Pais, R and Lohs, C and Wu, Y and Wang, J and Aksoy, S}, title = {The obligate mutualist Wigglesworthia glossinidia influences reproduction, digestion, and immunity processes of its host, the tsetse fly.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {19}, pages = {5965-5974}, pmid = {18689507}, issn = {1098-5336}, support = {069449//PHS HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; 051584//PHS HHS/United States ; R01 GM069449-04/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R01 AI051584-05/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage ; *Digestion ; Enterobacteriaceae/drug effects/physiology ; Female ; *Fertility ; Hemoglobins/metabolism ; *Immunity ; In Situ Hybridization, Fluorescence ; Male ; Polymerase Chain Reaction/methods ; Survival Analysis ; *Symbiosis ; Tsetse Flies/*microbiology/*physiology ; Wigglesworthia/drug effects/*physiology ; }, abstract = {Tsetse flies (Diptera: Glossinidae) are vectors for trypanosome parasites, the agents of the deadly sleeping sickness disease in Africa. Tsetse also harbor two maternally transmitted enteric mutualist endosymbionts: the primary intracellular obligate Wigglesworthia glossinidia and the secondary commensal Sodalis glossinidius. Both endosymbionts are transmitted to the intrauterine progeny through the milk gland secretions of the viviparous female. We administered various antibiotics either continuously by per os supplementation of the host blood meal diet or discretely by hemocoelic injections into fertile females in an effort to selectively eliminate the symbionts to study their individual functions. A symbiont-specific PCR amplification assay and fluorescence in situ hybridization analysis were used to evaluate symbiont infection outcomes. Tetracycline and rifampin treatments eliminated all tsetse symbionts but reduced the fecundity of the treated females. Ampicillin treatments did not affect the intracellular Wigglesworthia localized in the bacteriome organ and retained female fecundity. The resulting progeny of ampicillin-treated females, however, lacked Wigglesworthia but still harbored the commensal Sodalis. Our results confirm the presence of two physiologically distinct Wigglesworthia populations: the bacteriome-localized Wigglesworthia involved with nutritional symbiosis and free-living Wigglesworthia in the milk gland organ responsible for maternal transmission to the progeny. We evaluated the reproductive fitness, longevity, digestion, and vectorial competence of flies that were devoid of Wigglesworthia. The absence of Wigglesworthia completely abolished the fertility of females but not that of males. Both the male and female Wigglesworthia-free adult progeny displayed longevity costs and were significantly compromised in their blood meal digestion ability. Finally, while the vectorial competence of the young newly hatched adults without Wigglesworthia was comparable to that of their wild-type counterparts, older flies displayed higher susceptibility to trypanosome infections, indicating a role for the mutualistic symbiosis in host immunobiology. The ability to rear adult tsetse that lack the obligate Wigglesworthia endosymbionts will now enable functional investigations into this ancient symbiosis.}, }
@article {pmid18683631, year = {2008}, author = {Gil, R and Belda, E and Gosalbes, MJ and Delaye, L and Vallier, A and Vincent-Monégat, C and Heddi, A and Silva, FJ and Moya, A and Latorre, A}, title = {Massive presence of insertion sequences in the genome of SOPE, the primary endosymbiont of the rice weevil Sitophilus oryzae.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {11}, number = {1}, pages = {41-48}, pmid = {18683631}, issn = {1139-6709}, mesh = {Animals ; Evolution, Molecular ; Gammaproteobacteria/*physiology ; Genome, Bacterial/*genetics ; Insecta/*microbiology/physiology ; *Mutagenesis, Insertional ; Open Reading Frames ; Oryza/parasitology ; *Symbiosis ; Weevils/*microbiology/physiology ; }, abstract = {Bacteria that establish an obligate intracellular relationship with eukaryotic hosts undergo an evolutionary genomic reductive process. Recent studies have shown an increase in the number of mobile elements in the first stage of the adaptive process towards intracellular life, although these elements are absent in ancient endosymbionts. Here, the genome of SOPE, the obligate mutualistic endosymbiont of rice weevils, was used as a model to analyze the initial events that occur after symbiotic integration. During the first phases of the SOPE genome project, four different types of insertion sequence (IS) elements, belonging to well-characterized IS families from gamma-proteobacteria, were identified. In the present study, these elements, which may represent more than 20% of the complete genome, were completely characterized; their relevance as a source of gene inactivation, chromosomal rearrangements, and as participants in the genome reductive process are discussed herein.}, }
@article {pmid18682837, year = {2008}, author = {Coesel, S and Oborník, M and Varela, J and Falciatore, A and Bowler, C}, title = {Evolutionary origins and functions of the carotenoid biosynthetic pathway in marine diatoms.}, journal = {PloS one}, volume = {3}, number = {8}, pages = {e2896}, pmid = {18682837}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Carotenoids/*biosynthesis ; Conserved Sequence ; Diatoms/enzymology/genetics/*metabolism ; Molecular Sequence Data ; Oxidoreductases/genetics/metabolism ; Seawater/microbiology ; Sequence Alignment ; }, abstract = {Carotenoids are produced by all photosynthetic organisms, where they play essential roles in light harvesting and photoprotection. The carotenoid biosynthetic pathway of diatoms is largely unstudied, but is of particular interest because these organisms have a very different evolutionary history with respect to the Plantae and are thought to be derived from an ancient secondary endosymbiosis between heterotrophic and autotrophic eukaryotes. Furthermore, diatoms have an additional xanthophyll-based cycle for dissipating excess light energy with respect to green algae and higher plants. To explore the origins and functions of the carotenoid pathway in diatoms we searched for genes encoding pathway components in the recently completed genome sequences of two marine diatoms. Consistent with the supplemental xanthophyll cycle in diatoms, we found more copies of the genes encoding violaxanthin de-epoxidase (VDE) and zeaxanthin epoxidase (ZEP) enzymes compared with other photosynthetic eukaryotes. However, the similarity of these enzymes with those of higher plants indicates that they had very probably diversified before the secondary endosymbiosis had occurred, implying that VDE and ZEP represent early eukaryotic innovations in the Plantae. Consequently, the diatom chromist lineage likely obtained all paralogues of ZEP and VDE genes during the process of secondary endosymbiosis by gene transfer from the nucleus of the algal endosymbiont to the host nucleus. Furthermore, the presence of a ZEP gene in Tetrahymena thermophila provides the first evidence for a secondary plastid gene encoded in a heterotrophic ciliate, providing support for the chromalveolate hypothesis. Protein domain structures and expression analyses in the pennate diatom Phaeodactylum tricornutum indicate diverse roles for the different ZEP and VDE isoforms and demonstrate that they are differentially regulated by light. These studies therefore reveal the ancient origins of several components of the carotenoid biosynthesis pathway in photosynthetic eukaryotes and provide information about how they have diversified and acquired new functions in the diatoms.}, }
@article {pmid18682373, year = {2008}, author = {Härri, SA and Krauss, J and Müller, CB}, title = {Fungal endosymbionts of plants reduce lifespan of an aphid secondary parasitoid and influence host selection.}, journal = {Proceedings. Biological sciences}, volume = {275}, number = {1651}, pages = {2627-2632}, pmid = {18682373}, issn = {0962-8452}, mesh = {Animals ; Aphids/*physiology ; Female ; Fungi/*physiology ; Host-Parasite Interactions ; Plants/*microbiology ; Wasps/*physiology ; }, abstract = {Complex biotic interactions shape ecological communities of plants, herbivores and their natural enemies. In studies of multi-trophic interactions, the presence of small, invisible micro-organisms associated with plants and those of a fourth above-ground trophic level have often been neglected. Incorporating these neglected factors improves our understanding of the processes within a multi-trophic network. Here, we ask whether the presence of a fungal endosymbiont, which alters plant quality by producing herbivore-toxic substances, trickles up the food chain and affects the performance and host-selection behaviour of aphid secondary parasitoids. We simultaneously offered hosts from endophyte-free and endophyte-infected environments to secondary parasitoids. Older and more experienced parasitoid females discriminated against hosts from the endophyte-infected environment. Developing in lower quality hosts from the endophyte-infected environment reduced the lifespan of secondary parasitoids. This indicates that aphid secondary parasitoids can perceive the disadvantage for their developing offspring in parasitoids from the endophyte environment and can learn to discriminate against them. In the field, this discrimination ability may shift the success of primary parasitoids to endophyte-infected plants, which co-occur with endophyte-free plants. Ultimately, the control of aphids depends on complex interactions between primary and secondary parasitoids and their relative sensitivity to endophytic fungi.}, }
@article {pmid18678931, year = {2008}, author = {Akazaki, H and Kawai, F and Chida, H and Matsumoto, Y and Hirayama, M and Hoshikawa, K and Unzai, S and Hakamata, W and Nishio, T and Park, SY and Oku, T}, title = {Cloning, expression and purification of cytochrome c(6) from the brown alga Hizikia fusiformis and complete X-ray diffraction analysis of the structure.}, journal = {Acta crystallographica. Section F, Structural biology and crystallization communications}, volume = {64}, number = {Pt 8}, pages = {674-680}, pmid = {18678931}, issn = {1744-3091}, mesh = {Base Sequence ; Cloning, Molecular ; Crystallography, X-Ray ; Cytochromes c6/chemistry/*genetics/*isolation &amp; purification ; DNA Primers ; Phaeophyta/*enzymology ; Protein Conformation ; }, abstract = {The primary sequence of cytochrome c(6) from the brown alga Hizikia fusiformis has been determined by cDNA cloning and the crystal structure has been solved at 1.6 A resolution. The crystal belonged to the tetragonal space group P4(1)2(1)2, with unit-cell parameters a = b = 84.58, c = 232.91 A and six molecules per asymmetric unit. The genome code, amino-acid sequence and crystal structure of H. fusiformis cytochrome c(6) were most similar to those of red algal cytochrome c(6). These results support the hypothesis that brown algae acquired their chloroplasts via secondary endosymbiosis involving a red algal endosymbiont and a eukaryote host.}, }
@article {pmid18657108, year = {2008}, author = {Muglia, C and Comai, G and Spegazzini, E and Riccillo, PM and Aguilar, OM}, title = {Glutathione produced by Rhizobium tropici is important to prevent early senescence in common bean nodules.}, journal = {FEMS microbiology letters}, volume = {286}, number = {2}, pages = {191-198}, doi = {10.1111/j.1574-6968.2008.01285.x}, pmid = {18657108}, issn = {0378-1097}, mesh = {*Aging ; Bacterial Proteins/genetics ; Biomass ; Gene Deletion ; Gene Expression Profiling ; Glutathione/*biosynthesis ; Nitrogen Fixation ; Phaseolus/chemistry/growth &amp; development/*microbiology/*physiology ; Plant Roots/chemistry/microbiology ; Rhizobium tropici/*metabolism ; Superoxides/analysis ; *Symbiosis ; }, abstract = {In this paper, we examine the importance of glutathione in symbiosis, using a glutathione biosynthetic gshB mutant derived from Rhizobium tropici CIAT899, a common bean (Phaseolus vulgaris) endosymbiont. Plants infected with the mutant strain presented a delayed nodulation phenotype and a reduction in the dry weight of aerial part of plants, suggesting diminished nitrogen-fixation activity. In addition, bacterial gshB expression was assayed in wild-type infected nodules, during the different steps of nodulation, and found to increase in mature and early senescent nodules. Conspicuously, nodules induced by gshB mutant bacteria presented an early senescent pattern, which was associated with increased levels of superoxide accumulation. These results provide a direct evidence of the role of bacterial glutathione in protecting nodules from reactive oxygen species, which may determine nodule senescence.}, }
@article {pmid18650358, year = {2008}, author = {Escudero, R and Toledo, A and Gil, H and Kovácsová, K and Rodríguez-Vargas, M and Jado, I and García-Amil, C and Lobo, B and Bhide, M and Anda, P}, title = {Molecular method for discrimination between Francisella tularensis and Francisella-like endosymbionts.}, journal = {Journal of clinical microbiology}, volume = {46}, number = {9}, pages = {3139-3143}, pmid = {18650358}, issn = {1098-660X}, mesh = {DNA Probes/genetics ; DNA, Bacterial/genetics ; Francisella/*genetics ; Francisella tularensis/*genetics ; Humans ; Sensitivity and Specificity ; Sequence Alignment ; Tularemia/*diagnosis/microbiology ; }, abstract = {Environmental studies on the distribution of Francisella spp. are hampered by the frequency of Francisella-like endosymbionts that can produce a misleading positive result. A new, efficient molecular method for detection of Francisella tularensis and its discrimination from Francisella-like endosymbionts, as well as two variants associated with human disease (unusual F. tularensis strain FnSp1 and F. tularensis subsp. novicida-like strain 3523), is described. The method is highly specific and sensitive, detecting up to one plasmid copy or 10 genome equivalents.}, }
@article {pmid18648995, year = {2008}, author = {Novelli, VM and Freitas-Astúa, J and Segatti, N and Mineiro, JL and Arthur, V and Bastianel, M and Hilf, ME and Gottwald, TR and Machado, MA}, title = {Effects of radiation (Cobalt-60) on the elimination of Brevipalpus phoenicis (Acari: Tenuipalpidae) Cardinium endosymbiont.}, journal = {Experimental &amp; applied acarology}, volume = {45}, number = {3-4}, pages = {147-153}, pmid = {18648995}, issn = {1572-9702}, mesh = {Animals ; Bacteroidetes/*radiation effects ; *Cobalt Radioisotopes ; Dose-Response Relationship, Radiation ; Female ; Male ; Mites/growth &amp; development/*microbiology/radiation effects ; Plant Diseases ; }, abstract = {Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) is a polyphagous mite with worldwide distribution and it is also a vector of several plant viruses. In citrus, B. phoenicis transmits Citrus leprosis virus (CiLV), the causal agent of leprosis, a disease that costs millions of dollars per year for its prevention and control. Brevipalpus phoenicis mites reproduce through thelytokous parthenogenesis, producing haploid females. This characteristic is attributable to the presence of an endosymbiont bacterium of the genus Cardinium; however, very little is known about the biological and ecological implications of the presence of this endosymbiont in Brevipalpus mites. In order to investigate the role of Cardinium in the transmission of CiLV to citrus plants, our goal was to eliminate the bacterium from the mite. We assessed the effectiveness of different doses of radiation from a Cobalt-60 source to cure B. phoenicis populations from Cardinium sp. The efficiency of irradiation on the elimination of the endosymbiont was determined by counting the number of females and males obtained in the F(1) generation after irradiation and confirming the presence of the endosymbiont by PCR. Both radiation treatments influenced the oviposition period and the number of eggs laid by irradiated females. Also, irradiation eliminated the Cardinium endosymbiont and increased the number of males in progeny of the exposed populations. Although macroscopic morphological abnormalities were not observed among the treated mites, the mortality was higher compared to the non-irradiated control group.}, }
@article {pmid18647605, year = {2008}, author = {Attardo, GM and Lohs, C and Heddi, A and Alam, UH and Yildirim, S and Aksoy, S}, title = {Analysis of milk gland structure and function in Glossina morsitans: milk protein production, symbiont populations and fecundity.}, journal = {Journal of insect physiology}, volume = {54}, number = {8}, pages = {1236-1242}, pmid = {18647605}, issn = {0022-1910}, support = {R01 AI081774/AI/NIAID NIH HHS/United States ; 069449//PHS HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; 051584//PHS HHS/United States ; F32 GM077964/GM/NIGMS NIH HHS/United States ; R01 GM069449-04/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; R01 AI051584-05/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Enterobacteriaceae/*physiology ; Female ; Fertility ; Insect Proteins/*metabolism ; Reproduction ; *Symbiosis ; Tsetse Flies/anatomy &amp; histology/genetics/microbiology/*physiology ; Wigglesworthia/*physiology ; }, abstract = {A key process in the tsetse reproductive cycle is the transfer of essential nutrients and bacterial symbionts from mother to intrauterine offspring. The tissue mediating this transfer is the milk gland. This work focuses upon the localization and function of two milk proteins (milk gland protein (GmmMGP) and transferrin (GmmTsf)) and the tsetse endosymbionts (Sodalis and Wigglesworthia), in the context of milk gland physiology. Fluorescent in situ hybridization (FISH) and immunohistochemical analysis confirm that the milk gland secretory cells synthesize and secrete milk gland protein and transferrin. Knockdown of gmmmgp by double stranded RNA (dsRNA) mediated RNA interference results in reduction of tsetse fecundity, demonstrating its functional importance in larval nutrition and development. Bacterial species-specific in situ hybridizations of milk gland sections reveal large numbers of Sodalis and Wigglesworthia within the lumen of the milk gland. Sodalis is also localized within the cytoplasm of the secretory cells. Within the lumen, Wigglesworthia localize close to the channels leading to the milk storage reservoir of the milk gland secretory cells. We discuss the significance of the milk gland in larval nutrition and in transmission of symbiotic bacteria to developing offspring.}, }
@article {pmid18647416, year = {2008}, author = {Chantangsi, C and Esson, HJ and Leander, BS}, title = {Morphology and molecular phylogeny of a marine interstitial tetraflagellate with putative endosymbionts: Auranticordis quadriverberis n. gen. et sp. (Cercozoa).}, journal = {BMC microbiology}, volume = {8}, number = {}, pages = {123}, pmid = {18647416}, issn = {1471-2180}, mesh = {Adhesives ; Animals ; Base Sequence ; DNA/genetics ; DNA, Ribosomal/genetics ; Eukaryota/classification/*genetics/ultrastructure ; Flagella/ultrastructure ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; Pigments, Biological ; Polymerase Chain Reaction ; Sequence Alignment ; *Symbiosis ; }, abstract = {BACKGROUND: Comparative morphological studies and environmental sequencing surveys indicate that marine benthic environments contain a diverse assortment of microorganisms that are just beginning to be explored and characterized. The most conspicuous predatory flagellates in these habitats range from about 20-150 mum in size and fall into three major groups of eukaryotes that are very distantly related to one another: dinoflagellates, euglenids and cercozoans. The Cercozoa is a diverse group of amoeboflagellates that cluster together in molecular phylogenies inferred mainly from ribosomal gene sequences. These molecular phylogenetic studies have demonstrated that several enigmatic taxa, previously treated as Eukaryota insertae sedis, fall within the Cercozoa, and suggest that the actual diversity of this group is largely unknown. Improved knowledge of cercozoan diversity is expected to help resolve major branches in the tree of eukaryotes and demonstrate important cellular innovations for understanding eukaryote evolution.<br><br>RESULTS: A rare tetraflagellate, Auranticordis quadriverberis n. gen. et sp., was isolated from marine sand samples. Uncultured cells were in low abundance and were individually prepared for electron microscopy and DNA sequencing. These flagellates possessed several novel features, such as (1) gliding motility associated with four bundled recurrent flagella, (2) heart-shaped cells about 35-75 microm in diam., and (3) bright orange coloration caused by linear arrays of muciferous bodies. Each cell also possessed about 2-30 pale orange bodies (usually 4-5 microm in diam.) that were enveloped by two membranes and sac-like vesicles. The innermost membrane invaginated to form unstacked thylakoids that extended towards a central pyrenoid containing tailed viral particles. Although to our knowledge, these bodies have never been described in any other eukaryote, the ultrastructure was most consistent with photosynthetic endosymbionts of cyanobacterial origin. This combination of morphological features did not allow us to assign A. quadriverberis to any known eukaryotic supergroup. Thus, we sequenced the small subunit rDNA sequence from two different isolates and demonstrated that this lineage evolved from within the Cercozoa.<br><br>CONCLUSION: Our discovery and characterization of A. quadriverberis underscores how poorly we understand the diversity of cercozoans and, potentially, represents one of the few independent cases of primary endosymbiosis within the Cercozoa and beyond.}, }
@article {pmid18643952, year = {2008}, author = {Dove, SG and Lovell, C and Fine, M and Deckenback, J and Hoegh-Guldberg, O and Iglesias-Prieto, R and Anthony, KR}, title = {Host pigments: potential facilitators of photosynthesis in coral symbioses.}, journal = {Plant, cell &amp; environment}, volume = {31}, number = {11}, pages = {1523-1533}, doi = {10.1111/j.1365-3040.2008.01852.x}, pmid = {18643952}, issn = {1365-3040}, mesh = {Acclimatization ; Analysis of Variance ; Animals ; Anthozoa/chemistry/*metabolism ; Dinoflagellida/chemistry/*metabolism ; Light ; Oxygen/metabolism ; *Photosynthesis ; Pigmentation/physiology ; Pigments, Biological/chemistry/*physiology ; Species Specificity ; *Symbiosis ; }, abstract = {Reef-building corals occur as a range of colour morphs because of varying types and concentrations of pigments within the host tissues, but little is known about their physiological or ecological significance. Here, we examined whether specific host pigments act as an alternative mechanism for photoacclimation in the coral holobiont. We used the coral Montipora monasteriata (Forskål 1775) as a case study because it occurs in multiple colour morphs (tan, blue, brown, green and red) within varying light-habitat distributions. We demonstrated that two of the non-fluorescent host pigments are responsive to changes in external irradiance, with some host pigments up-regulating in response to elevated irradiance. This appeared to facilitate the retention of antennal chlorophyll by endosymbionts and hence, photosynthetic capacity. Specifically, net P(max) Chl a(-1) correlated strongly with the concentration of an orange-absorbing non-fluorescent pigment (CP-580). This had major implications for the energetics of bleached blue-pigmented (CP-580) colonies that maintained net P(max) cm(-2) by increasing P(max) Chl a(-1). The data suggested that blue morphs can bleach, decreasing their symbiont populations by an order of magnitude without compromising symbiont or coral health.}, }
@article {pmid18641160, year = {2008}, author = {Schmitz-Esser, S and Toenshoff, ER and Haider, S and Heinz, E and Hoenninger, VM and Wagner, M and Horn, M}, title = {Diversity of bacterial endosymbionts of environmental acanthamoeba isolates.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {18}, pages = {5822-5831}, pmid = {18641160}, issn = {1098-5336}, support = {P 19252/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Acanthamoeba/genetics/*microbiology ; Animals ; Bacteria/*classification/genetics ; *Biodiversity ; DNA, Bacterial/genetics ; DNA, Protozoan/genetics ; Genes, Bacterial ; Genes, Protozoan ; Genes, rRNA ; Geologic Sediments/microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Soil Microbiology ; *Symbiosis ; Water Microbiology ; }, abstract = {Free-living amoebae are frequent hosts for bacterial endosymbionts. In this study, the symbionts of eight novel environmental Acanthamoeba strains isolated from different locations worldwide were characterized. Phylogenetic analysis revealed that they were related to one of four evolutionary lineages of amoeba symbionts recognized previously. This study provides evidence for the existence of only a small number of phylogenetically well-separated groups of obligate intracellular endosymbionts of acanthamoebae with global distribution.}, }
@article {pmid18640072, year = {2009}, author = {Feldhaar, H and Gross, R}, title = {Insects as hosts for mutualistic bacteria.}, journal = {International journal of medical microbiology : IJMM}, volume = {299}, number = {1}, pages = {1-8}, doi = {10.1016/j.ijmm.2008.05.010}, pmid = {18640072}, issn = {1618-0607}, mesh = {Animals ; *Bacterial Physiological Phenomena ; *Cell Physiological Phenomena ; Cells/*microbiology ; Insecta/cytology/*microbiology/*physiology ; *Symbiosis ; }, abstract = {Insects are among the most successful animals on Earth both with regard to their biomass and biodiversity. It is estimated that up to 20% of all insects are obligately associated with symbiotic microorganisms, and it is likely that their capacity to engage microbial companions has greatly contributed to their evolutionary success. The main focus of this review lies on obligately intracellular bacteria residing in specialized cells, the bacteriocytes, provided by the host. In the past few years the focus in research on these bacteria has been on their biological role for the host and the consequences on the genome and metabolic capacities shaped by a long-lasting obligate association confined to the interior of a eukaryotic host cell. Here, we compare those endosymbiont-host interactions where the genome of the bacterium is sequenced.}, }
@article {pmid18638407, year = {2008}, author = {Mahadav, A and Gerling, D and Gottlieb, Y and Czosnek, H and Ghanim, M}, title = {Parasitization by the wasp Eretmocerus mundus induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly Bemisia tabaci.}, journal = {BMC genomics}, volume = {9}, number = {}, pages = {342}, pmid = {18638407}, issn = {1471-2164}, mesh = {Animals ; Bacteria/*growth &amp; development ; Genes, Insect/*immunology ; Hemiptera/*microbiology/parasitology ; Host-Parasite Interactions ; *Symbiosis ; *Transcription, Genetic ; Wasps/*physiology ; }, abstract = {BACKGROUND: The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and the viruses it transmits, are a major constraint to growing vegetable crops worldwide. Although the whitefly is often controlled using chemical pesticides, biological control agents constitute an important component in integrated pest management programs, especially in protected agriculture. One of these agents is the wasp Eretmocerus mundus (Mercet) (Hymenoptera: Aphelinidae). E. mundus lays its egg on the leaf underneath the second-third instar nymph of B. tabaci. First instars of the wasp hatch and penetrate the whitefly nymphs. Initiation of parasitization induces the host to form a capsule composed of epidermal cells around the parasitoid. The physiological and molecular processes underlying B. tabaci-E. mundus interactions have never been investigated.<br><br>RESULTS: We used a cDNA microarray containing 6,000 expressed sequence tags (ESTs) from the whitefly genome to study the parasitoid-whitefly interaction. We compared RNA samples collected at two time points of the parasitization process: when the parasitoid first instar starts the penetration process and once it has fully penetrated the host. The results clearly indicated that genes known to be part of the defense pathways described in other insects are also involved in the response of B. tabaci to parasitization by E. mundus. Some of these responses included repression of a serine protease inhibitor (serpin) and induction of a melanization cascade. A second set of genes that responded strongly to parasitization were bacterial, encoded by whitefly symbionts. Quantitative real-time PCR and FISH analyses showed that proliferation of Rickettsia, a facultative secondary symbiont, is strongly induced upon initiation of the parasitization process, a result that supported previous reports suggesting that endosymbionts might be involved in the insect host's resistance to various environmental stresses.<br><br>CONCLUSION: This is the first study to examine the transcriptional response of a hemipteran insect to attack by a biological control agent (hymenopterous parasitoid), using a new genomic approach developed for this insect pest. The defense response in B. tabaci involves genes related to the immune response as described in model organisms such as Drosophila melanogaster. Moreover, endosymbionts of B. tabaci appear to play a role in the response to parasitization, as supported by previously published results from aphids.}, }
@article {pmid18636277, year = {2008}, author = {Härri, SA and Krauss, J and Müller, CB}, title = {Trophic cascades initiated by fungal plant endosymbionts impair reproductive performance of parasitoids in the second generation.}, journal = {Oecologia}, volume = {157}, number = {3}, pages = {399-407}, pmid = {18636277}, issn = {0029-8549}, mesh = {Animals ; Aphids/*parasitology/*physiology ; Female ; *Food Chain ; Fungi/physiology ; Host-Parasite Interactions/*physiology ; Lolium/*microbiology ; Male ; Reproduction/physiology ; *Symbiosis ; Wasps/growth &amp; development/*physiology ; }, abstract = {Variation in plant quality can transmit up the food chain and may affect herbivores and their antagonists in the same direction. Fungal endosymbionts of grasses change the resource quality by producing toxins. We used an aphid-parasitoid model system to explore how endophyte effects cascade up the food chain and influence individual parasitoid performance. We show that the presence of an endophyte in the grass Lolium perenne has a much stronger negative impact on the performance of the parasitoid Aphidius ervi than on its aphid host Metopolophium festucae. Although the presence of endophytes did not influence the parasitism rate of endophyte-naïve parasitoids or their offspring's survival to adulthood, most parasitoids developing within aphids from endophyte-infected plants did not reproduce at all. This indicates a delayed but very strong effect of endophytes on parasitoid performance, which should ultimately affect plant performance negatively by releasing endophyte-tolerant herbivores from top-down limitations.}, }
@article {pmid18635679, year = {2008}, author = {Toft, C and Fares, MA}, title = {The evolution of the flagellar assembly pathway in endosymbiotic bacterial genomes.}, journal = {Molecular biology and evolution}, volume = {25}, number = {9}, pages = {2069-2076}, doi = {10.1093/molbev/msn153}, pmid = {18635679}, issn = {1537-1719}, mesh = {Animals ; Aphids/microbiology ; Bacterial Proteins/metabolism ; Buchnera/genetics ; Escherichia coli/genetics ; *Evolution, Molecular ; Flagella/*genetics ; Gammaproteobacteria/*genetics/physiology ; Gene Deletion ; *Genome, Bacterial ; Protein Transport/genetics ; Salmonella typhimurium/genetics ; Selection, Genetic ; Symbiosis/*genetics ; }, abstract = {Genome shrinkage is a common feature of most intracellular pathogens and symbionts. Reduction of genome sizes is among the best-characterized evolutionary ways of intracellular organisms to save and avoid maintaining expensive redundant biological processes. Endosymbiotic bacteria of insects are examples of biological economy taken to completion because their genomes are dramatically reduced. These bacteria are nonmotile, and their biochemical processes are intimately related to those of their host. Because of this relationship, many of the processes in these bacteria have been either lost or have suffered massive remodeling to adapt to the intracellular symbiotic lifestyle. An example of such changes is the flagellum structure that is essential for bacterial motility and infectivity. Our analysis indicates that genes responsible for flagellar assembly have been partially or totally lost in most intracellular symbionts of gamma-Proteobacteria. Comparative genomic analyses show that flagellar genes have been differentially lost in endosymbiotic bacteria of insects. Only proteins involved in protein export within the flagella assembly pathway (type III secretion system and the basal body) have been kept in most of the endosymbionts, whereas those involved in building the filament and hook of flagella have only in few instances been kept, indicating a change in the functional purpose of this pathway. In some endosymbionts, genes controlling protein-export switch and hook length have undergone functional divergence as shown through an analysis of their evolutionary dynamics. Based on our results, we suggest that genes of flagellum have diverged functionally as to specialize in the export of proteins from the bacterium to the host.}, }
@article {pmid18628941, year = {2001}, author = {Wixon, J}, title = {Featured organism: reductive evolution in bacteria: Buchnera sp., Rickettsia prowazekii and Mycobacterium leprae.}, journal = {Comparative and functional genomics}, volume = {2}, number = {1}, pages = {44-48}, pmid = {18628941}, issn = {1531-6912}, abstract = {Obligate intracellular bacteria commonly have much reduced genome sizes compared to their nearest free-living relatives. One reason for this is reductive evolution: the loss of genes rendered non-essential due to the intracellular habitat. This can occur because of the presence of orthologous genes in the host, combined with the ability of the bacteria to import the protein or metabolite products of the host genes. In this article we take a look at three such bacteria whose genomes have been fully sequenced. Buchnera is an endosymbiont of the pea aphid, Acyrthosiphon pisum, the relationship between these two organisms being so essential that neither can reproduce in the absence of the other. Rickettsia prowazekii is the causative agent of louse-borne typhus in humans and Mycobacterium leprae infection of humans leads to leprosy. Both of these human pathogens have fastidious growth requirements, which has made them very difficult to study.}, }
@article {pmid18627380, year = {2008}, author = {Labropoulou, V and Douris, V and Stefanou, D and Magrioti, C and Swevers, L and Iatrou, K}, title = {Endoparasitoid wasp bracovirus-mediated inhibition of hemolin function and lepidopteran host immunosuppression.}, journal = {Cellular microbiology}, volume = {10}, number = {10}, pages = {2118-2128}, doi = {10.1111/j.1462-5822.2008.01195.x}, pmid = {18627380}, issn = {1462-5822}, mesh = {Agglutination ; Animals ; Bombyx/*immunology ; Cell Membrane/chemistry ; Hemocytes/immunology ; Immunoglobulins/immunology ; *Immunosuppression Therapy ; Insect Proteins/*antagonists &amp; inhibitors/immunology ; Microscopy, Fluorescence ; Polydnaviridae/*immunology ; Protein Binding ; Viral Proteins/analysis ; Wasps/*virology ; }, abstract = {Successful embryonic development of parasitoid wasps in lepidopteran hosts is achieved through co-injection of polydna viruses whose gene products are thought to target the immune responses of the host. One gene product of the endosymbiont bracovirus of the parasitic wasp Cotesia rubecula, CrV1, has been reported to inhibit the immune responses of its endoparasitized lepidopteran host through interference with the haematocyte cytoskeletal structure. Here we establish that CcV1, the Cotesia congregata bracovirus orthologue of CrV1, is also uptaken by lepidopteran haemocytes and haemocyte-like established cell lines, but we also report on a different function of CcV1, which is highly relevant to the inhibition of the host immune responses and is based on its direct interaction with the pattern recognition molecule hemolin. Recombinant CcV1 inhibits hemolin functions, such as lipopolysaccharide binding and bacterial agglutination as well as bacterial phagocytosis by haemocytes and haemocyte-like cell lines, producing functional phenotypes equivalent to those observed to arise from RNAi-based inhibition of hemolin gene expression. Finally, we show that CcV1 and hemolin colocalize on the membrane surface of hemolin-expressing cells, a finding suggesting that CcV1 may be uptaken by haemocytes and inhibit haemocyte function as a result of its interaction with membrane-anchored hemolin.}, }
@article {pmid18619822, year = {2008}, author = {Dyková, I and Fiala, I and Dvoráková, H and Pecková, H}, title = {Living together: the marine amoeba Thecamoeba hilla Schaeffer, 1926 and its endosymbiont Labyrinthula sp.}, journal = {European journal of protistology}, volume = {44}, number = {4}, pages = {308-316}, doi = {10.1016/j.ejop.2008.04.001}, pmid = {18619822}, issn = {0932-4739}, mesh = {Amoeba/genetics/*physiology/ultrastructure ; Animals ; Phylogeny ; *Symbiosis ; }, abstract = {Two protists isolated simultaneously from the same sample of gill tissue of Psetta maxima (L.) were identified as Thecamoeba hilla Schaeffer, 1926 and Labyrinthula sp. A Labyrinthula strain (LTH) derived from a mixed culture of both organisms was well established in a short time, while subcultures of T. hilla continued to be associated with Labyrinthula cells despite all efforts to eliminate them. Ultrastructural examination, repeated several times in the course of long-lasting subculturing of amoebae, revealed that trophozoites of T. hilla host in their cytoplasm multiplying labyrinthulid cells. Comparison of SSU rDNA sequences of the Labyrinthula strain LTH and those from labyrinthulid endosymbionts from T. hilla verified the assumption that the extra- and intra-cellularly multiplying Labyrinthula cells are identical organisms. The association of the marine amoeba T. hilla and Labyrinthula sp. displayed signs of mutualistic symbiosis.}, }
@article {pmid18618173, year = {2008}, author = {Osaka, R and Nomura, M and Watada, M and Kageyama, D}, title = {Negative effects of low temperatures on the vertical transmission and infection density of a spiroplasma endosymbiont in Drosophila hydei.}, journal = {Current microbiology}, volume = {57}, number = {4}, pages = {335-339}, pmid = {18618173}, issn = {0343-8651}, mesh = {Animals ; Bacterial Proteins/genetics ; DNA, Bacterial/analysis ; DNA-Binding Proteins/genetics ; Drosophila/classification/growth &amp; development/*microbiology ; Female ; *Host-Pathogen Interactions ; Japan ; Male ; Polymerase Chain Reaction ; Spiroplasma/genetics/growth &amp; development/*isolation &amp; purification/*physiology ; *Symbiosis ; *Temperature ; }, abstract = {Maternally transmitted endosymbionts of the genus Spiroplasma infecting several species of Drosophila are known to cause selective death of male offspring (male killing). The male-killing trait is considered to be advantageous for maternally transmitted endosymbionts. However, a non-male-killing spiroplasma is present in Japanese populations of Drosophila hydei at high frequencies (23-66%). This spiroplasma is phylogenetically closely related to the male-killing spiroplasma infecting other Drosophila species. It is unknown why this spiroplasma is maintained in its host populations despite its inability to cause male killing. We examined the susceptibilities of the spiroplasma in D. hydei to four different temperatures (28, 25, 18, and 15 degrees C). Diagnostic PCR revealed that vertical transmission of the spiroplasma was nearly perfect at 28 and 25 degrees C, partially suppressed at 18 degrees C, and completely blocked at 15 degrees C. Furthermore, quantitative PCR demonstrated that offspring treated at 18 degrees C exhibited dramatically lower densities of spiroplasma (i.e., approximately one-tenth) compared to offspring treated at 28 and 25 degrees C. Considering the low temperatures during winter in Japan, some unknown advantageous effects of the spiroplasma that compensate for the failure of vertical transmission are suggested to act in natural populations of D. hydei.}, }
@article {pmid18599495, year = {2008}, author = {Gile, GH and Keeling, PJ}, title = {Nucleus-encoded periplastid-targeted EFL in chlorarachniophytes.}, journal = {Molecular biology and evolution}, volume = {25}, number = {9}, pages = {1967-1977}, doi = {10.1093/molbev/msn147}, pmid = {18599495}, issn = {1537-1719}, mesh = {Blotting, Western ; Cell Nucleus/genetics ; Chlorophyta/*genetics/metabolism ; Cryptophyta/genetics/metabolism ; Cytosol/metabolism ; Eukaryotic Cells ; Eukaryotic Initiation Factors/genetics/metabolism ; Evolution, Molecular ; GTP Phosphohydrolases/*genetics/metabolism ; Intracellular Membranes/metabolism ; Neoplasm Proteins/genetics/metabolism ; Nerve Tissue Proteins/genetics/metabolism ; Plastids/genetics ; *Protein Transport ; Symbiosis/genetics ; }, abstract = {Chlorarachniophytes are cercozoan amoeboflagellates that acquired photosynthesis by enslaving a green alga, which has retained a highly reduced nucleus called a nucleomorph. The nucleomorph lacks many genes necessary for its own maintenance and expression, suggesting that some genes have been moved to the host nucleus and their products are now targeted back to the periplastid compartment (PPC), the reduced eukaryotic cytoplasm of the endosymbiont. Protein trafficking in chlorarachniophytes is therefore complex, including nucleus-encoded plastid-targeted proteins, nucleomorph-encoded plastid-targeted proteins, and nucleus-encoded periplastid-targeted proteins. A major gap in our understanding of this system is the PPC-targeted proteins because none have been described in any chlorarachniophytes. Here we describe the first such protein, the GTPase EFL. EFL was characterized from 7 chlorarachniophytes, and 2 distinct types were found. One is related to foraminiferan EFL and lacks an amino-terminal extension. The second, distantly related, type encodes an amino-terminal extension consisting of a signal peptide followed by sequence sharing many characteristics with transit peptides from nucleus-encoded plastid-targeted proteins and which we conclude is most likely PPC targeted. Western blotting with antibodies specific to putative host and PPC-targeted EFL from the chlorarachniophytes Bigelowiella natans and Gymnochlora stellata is consistent with posttranslational cleavage of the leaders from PPC-targeted proteins. Immunolocalization of both proteins in B. natans confirmed the cytosolic location of the leaderless EFL and a distinct localization pattern for the PPC-targeted protein but could not rule out a plastid location (albeit very unlikely). We sought other proteins with a similar leader and identified a eukaryotic translation initiation factor 1 encoding a bipartite extension with the same properties. Transit peptide sequences were characterized from all 3 classes of targeted protein by comparing all examples of each class from expressed sequence tag surveys of B. natans and G. stellata. No recognizable difference between plastid- and PPC-targeted proteins was observed, but nucleomorph-encoded transit peptides differ, likely reflecting high AT content of nucleomorph genomes. Taken together, the data suggest that the system that directs proteins to the PPC in chlorarachniophytes uses a bipartite targeting sequence, as does the PPC-targeting system that evolved independently in cryptomonads.}, }
@article {pmid18598237, year = {2009}, author = {Himmel, D and Maurin, LC and Gros, O and Mansot, JL}, title = {Raman microspectrometry sulfur detection and characterization in the marine ectosymbiotic nematode Eubostrichus dianae (Desmodoridae, Stilbonematidae).}, journal = {Biology of the cell}, volume = {101}, number = {1}, pages = {43-54}, doi = {10.1042/BC20080051}, pmid = {18598237}, issn = {1768-322X}, mesh = {Animals ; Bacteria/chemistry ; Bivalvia/microbiology ; Microscopy ; Nematoda/*microbiology ; Spectrum Analysis, Raman/*methods ; Sulfur/*analysis ; *Symbiosis ; }, abstract = {BACKGROUND INFORMATION: Marine nematodes belonging to the Stilbonematidae (Desmodoridae) family are described as living in obligatory association with sulfur-oxidizing chemoautotrophic ectosymbionts. The symbiotic bacteria carrying out this chemosynthesis should contain elemental sulfur in periplasmic granules as sulfur granules of chemoautotrophic endosymbionts described in various marine invertebrates.<br><br>RESULTS: Based on TEM (transmission electron microscopy) analyses, extracellular bacteria surrounding Eubostrichus dianae possess these spherical periplasmic granules. Few investigative techniques can be used to identify elemental sulfur, S(8), such as EDXS (energy dispersive X-ray spectroscopy) and EELS (electron energy loss spectroscopy), which are associated with cryo-fixation of the sample to avoid sulfur loss. These techniques are time consuming, expensive and require technical skills. Raman microspectrometry applied to the analysis of E. dianae allowed us to detect elemental sulfur, S8, and confirmed the location of these sulfur clusters in the bacterial coat. In the same way, Raman spectrometry was positively applied to the endosymbiotic bivalve Codakia orbicularis, suggesting that this technique can be used to characterize sulfur in ecto- as well as in endo-symbiotic sulfur-oxidizing bacteria.<br><br>CONCLUSIONS: As Raman spectrometry can be used on living organisms (without preliminary fixation) without sample damage and preserving the molecular structure of the sulfur (denatured during chemical fixation), it represents a very well-adapted investigative tool for biologists. This technique therefore permits us to detect quickly and easily (in a few seconds and on entire living animals) the presence of sulfur compounds in the symbiotic nematode.}, }
@article {pmid18596972, year = {2008}, author = {Fishman, Y and Zlotkin, E and Sher, D}, title = {Expulsion of symbiotic algae during feeding by the green hydra--a mechanism for regulating symbiont density?.}, journal = {PloS one}, volume = {3}, number = {7}, pages = {e2603}, pmid = {18596972}, issn = {1932-6203}, mesh = {Animals ; Eukaryota/*physiology ; *Feeding Behavior ; Hydra/*physiology ; *Symbiosis ; }, abstract = {BACKGROUND: Algal-cnidarian symbiosis is one of the main factors contributing to the success of cnidarians, and is crucial for the maintenance of coral reefs. While loss of the symbionts (such as in coral bleaching) may cause the death of the cnidarian host, over-proliferation of the algae may also harm the host. Thus, there is a need for the host to regulate the population density of its symbionts. In the green hydra, Chlorohydra viridissima, the density of symbiotic algae may be controlled through host modulation of the algal cell cycle. Alternatively, Chlorohydra may actively expel their endosymbionts, although this phenomenon has only been observed under experimentally contrived stress conditions.<br><br>PRINCIPAL FINDINGS: We show, using light and electron microscopy, that Chlorohydra actively expel endosymbiotic algal cells during predatory feeding on Artemia. This expulsion occurs as part of the apocrine mode of secretion from the endodermal digestive cells, but may also occur via an independent exocytotic mechanism.<br><br>SIGNIFICANCE: Our results demonstrate, for the first time, active expulsion of endosymbiotic algae from cnidarians under natural conditions. We suggest this phenomenon may represent a mechanism whereby cnidarians can expel excess symbiotic algae when an alternative form of nutrition is available in the form of prey.}, }
@article {pmid18586942, year = {2008}, author = {Gosalbes, MJ and Lamelas, A and Moya, A and Latorre, A}, title = {The striking case of tryptophan provision in the cedar aphid Cinara cedri.}, journal = {Journal of bacteriology}, volume = {190}, number = {17}, pages = {6026-6029}, pmid = {18586942}, issn = {1098-5530}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/genetics/*metabolism/physiology ; Genes, Bacterial/genetics ; In Situ Hybridization ; Models, Genetic ; Molecular Sequence Data ; Plasmids/genetics/metabolism ; Symbiosis/genetics ; Tryptophan/*metabolism ; }, abstract = {Buchnera aphidicola BCc has lost its symbiotic role as the tryptophan supplier to the aphid Cinara cedri. We report the presence of a plasmid in this endosymbiont that contains the trpEG genes. The remaining genes for the pathway (trpDCBA) are located on the chromosome of the secondary endosymbiont "Candidatus Serratia symbiotica." Thus, we propose that a symbiotic consortium is necessary to provide tryptophan.}, }
@article {pmid18580972, year = {2008}, author = {Zeev, EB and Yogev, T and Man-Aharonovich, D and Kress, N and Herut, B and Béjà, O and Berman-Frank, I}, title = {Seasonal dynamics of the endosymbiotic, nitrogen-fixing cyanobacterium Richelia intracellularis in the eastern Mediterranean Sea.}, journal = {The ISME journal}, volume = {2}, number = {9}, pages = {911-923}, doi = {10.1038/ismej.2008.56}, pmid = {18580972}, issn = {1751-7370}, mesh = {Cyanobacteria/*growth &amp; development/*isolation &amp; purification/physiology ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Diatoms/microbiology ; Genes, rRNA ; Mediterranean Sea ; Molecular Sequence Data ; Nitrates/analysis ; Nitrites/analysis ; Nitrogen Fixation ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Seasons ; Seawater/chemistry/*microbiology ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Silicic Acid/analysis ; Symbiosis ; }, abstract = {Biological nitrogen fixation has been suggested as an important source of nitrogen for the ultra-oligotrophic waters of the Levantine Basin of the Mediterranean Sea. In this study, we identify and characterize the spatial and temporal distribution of the N-fixing (diazotrophic) cyanobacterium Richelia intracellularis. R. intracellularis is usually found as an endosymbiont within diatoms such as Rhizosolenia spp and Hemiaulus spp. and is an important diazotroph in marine tropical oceans. In this study, two stations off the Mediterranean coast of Israel were sampled monthly during 2005-2007. R. intracellularis was identified by microscopy and by reverse transcribed-PCR which confirmed a 98.8% identity with known nifH sequences of R. intracellularis from around the world. The diatom-diazotroph associations were found throughout the year peaking during autumn (October-November) at both stations. Abundance of R. intracellularis ranged from 10 to 55 heterocysts l(-1) and correlated positively with the dissolved Si(OH)(4)/(NO(3)+NO(2)) ratio in surface waters. Although the rates of nitrogen fixation were very low, averaging approximately 1.1 nmol N l(-1) day(-1) for the R. intracellularis size fraction (>10 microm) from surface waters, they correlated positively with heterocyst counts during thermal stratification. The lack of large-scale diatom-diazotroph blooms and the low rates of nitrogen fixation by these diazotrophs may result from the P-starved conditions affecting the Levantine basin.}, }
@article {pmid18577506, year = {2008}, author = {Abrego, D and Ulstrup, KE and Willis, BL and van Oppen, MJ}, title = {Species-specific interactions between algal endosymbionts and coral hosts define their bleaching response to heat and light stress.}, journal = {Proceedings. Biological sciences}, volume = {275}, number = {1648}, pages = {2273-2282}, pmid = {18577506}, issn = {0962-8452}, mesh = {Animals ; Anthozoa/*physiology ; Chlorophyll/analysis ; Chlorophyll A ; Eukaryota/*physiology ; Greenhouse Effect ; Photosynthesis/physiology ; Pilot Projects ; Species Specificity ; Statistics, Nonparametric ; Symbiosis/physiology ; Xanthophylls/analysis ; }, abstract = {The impacts of warming seas on the frequency and severity of bleaching events are well documented, but the potential for different Symbiodinium types to enhance the physiological tolerance of reef corals is not well understood. Here we compare the functionality and physiological properties of juvenile corals when experimentally infected with one of two homologous Symbiodinium types and exposed to combined heat and light stress. A suite of physiological indicators including chlorophyll a fluorescence, oxygen production and respiration, as well as pigment concentration consistently demonstrated lower metabolic costs and enhanced physiological tolerance of Acropora tenuis juveniles when hosting Symbiodinium type C1 compared with type D. In other studies, the same D-type has been shown to confer higher thermal tolerance than both C2 in adults and C1 in juveniles of the closely related species Acropora millepora. Our results challenge speculations that associations with type D are universally most robust to thermal stress. Although the heat tolerance of corals may be contingent on the Symbiodinium strain in hospite, our results highlight the complexity of interactions between symbiotic partners and a potential role for host factors in determining the physiological performance of reef corals.}, }
@article {pmid18573842, year = {2008}, author = {Ueda, M and Fujimoto, M and Arimura, S and Tsutsumi, N and Kadowaki, K}, title = {Presence of a latent mitochondrial targeting signal in gene on mitochondrial genome.}, journal = {Molecular biology and evolution}, volume = {25}, number = {9}, pages = {1791-1793}, doi = {10.1093/molbev/msn139}, pmid = {18573842}, issn = {1537-1719}, mesh = {Arabidopsis ; Arabidopsis Proteins/genetics/metabolism ; Cell Nucleus/genetics ; *Genes, Mitochondrial ; *Genes, Plant ; Genome, Plant ; Oryza ; Plant Proteins/*genetics/metabolism ; Protein Transport/*genetics ; Recombination, Genetic ; Ribosomal Proteins/genetics/metabolism ; }, abstract = {Organelles, such as mitochondria and chloroplasts, are derived from endosymbionts. Gene transfer events from organelles to the nucleus have occurred over evolutionary time. In the case that a transferred gene in the nucleus needs to go back to the original organelle, it must obtain targeting information for sorting its protein to that organelle. Here, we reveal that the genes for the ribosomal proteins L2 and S4 in the Arabidopsis thaliana mitochondrial (mt) genome contain information for protein targeting into the mitochondria. Similarly, the genes for the ribosomal proteins L2 and S19 in the Oryza sativa mt genome contain information for protein targeting into mitochondria. These results suggest that targeting information already existed in each gene in the plant mt genome before the transfer event to the nucleus occurred. We provide new insights into the timing of the appearance of targeting signals in evolution.}, }
@article {pmid18564376, year = {2008}, author = {McBride, R and Greig, D and Travisano, M}, title = {Fungal viral mutualism moderated by ploidy.}, journal = {Evolution; international journal of organic evolution}, volume = {62}, number = {9}, pages = {2372-2380}, doi = {10.1111/j.1558-5646.2008.00443.x}, pmid = {18564376}, issn = {0014-3820}, mesh = {*Diploidy ; *Haploidy ; Hydrogen-Ion Concentration ; RNA Viruses/*physiology ; Saccharomyces cerevisiae/physiology/*virology ; *Symbiosis ; }, abstract = {Endosymbionts and their hosts have inherently ambiguous relationships as symbionts typically depend upon their hosts for shelter, nutrition, and reproduction. Endosymbionts can acquire these needs by two alternative strategies: exploitation and cooperation. Parasites exploit hosts to advance their own reproduction at the cost of host fitness. In contrast, mutualists increase their reproductive output by increasing host fitness. Very often the distinction between parasites and mutualists is not discrete but rather contingent on the environment in which the interaction occurs, and can shift along a continuous scale from parasitism to mutualism. The cost benefit dynamics at any point along this continuum are of particular interest as they establish the likelihood of an interaction persisting or breaking down. Here we show how the interaction between the yeast Saccharomyces cerevisiae and an endosymbiotic killer virus is strongly dependent on both host ploidy and environmental pH. Additionally we elucidate the mechanisms underlying the ploidy-dependent interaction. Understanding these dynamics in the short-term is key to understanding how genetic and environmental factors impact community diversity.}, }
@article {pmid18562339, year = {2008}, author = {Cordaux, R and Pichon, S and Ling, A and Pérez, P and Delaunay, C and Vavre, F and Bouchon, D and Grève, P}, title = {Intense transpositional activity of insertion sequences in an ancient obligate endosymbiont.}, journal = {Molecular biology and evolution}, volume = {25}, number = {9}, pages = {1889-1896}, pmid = {18562339}, issn = {1537-1719}, mesh = {Animals ; Crustacea/microbiology ; *DNA Transposable Elements ; *DNA, Bacterial ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Insecta/microbiology ; Molecular Sequence Data ; Sequence Homology, Nucleic Acid ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {The streamlined genomes of ancient obligate endosymbionts generally lack transposable elements, such as insertion sequences (IS). Yet, the genome of Wolbachia, one of the most abundant bacterial endosymbionts on Earth, is littered with IS. Such a paradox raises the question as to why there are so many ISs in the genome of this ancient endosymbiont. To address this question, we investigated IS transpositional activity in the unculturable Wolbachia by tracking the evolutionary dynamics and history of ISWpi1 elements. We show that 1) ISWpi1 is widespread in Wolbachia, being present in at least 55% of the 40 sampled strains, 2) ISWpi1 copies exhibit virtually identical nucleotide sequences both within and among Wolbachia genomes and possess an intact transposase gene, 3) individual ISWpi1 copies are differentially inserted among Wolbachia genomes, and 4) ISWpi1 occurs at variable copy numbers among Wolbachia genomes. Collectively, our results provide compelling evidence for intense ISWpi1 transpositional activity and frequent ISWpi1 horizontal transmission among strains during recent Wolbachia evolution. Thus, the genomes of ancient obligate endosymbionts can carry high loads of functional and transpositionally active transposable elements. Our results also indicate that Wolbachia genomes have experienced multiple and temporally distinct ISWpi1 invasions during their evolutionary history. Such recurrent exposition to new IS invasions may explain, at least partly, the unusually high density of transposable elements found in the genomes of Wolbachia endosymbionts.}, }
@article {pmid18542983, year = {2008}, author = {Cavalcanti, DP and Thiry, M and de Souza, W and Motta, MC}, title = {The kinetoplast ultrastructural organization of endosymbiont-bearing trypanosomatids as revealed by deep-etching, cytochemical and immunocytochemical analysis.}, journal = {Histochemistry and cell biology}, volume = {130}, number = {6}, pages = {1177-1185}, pmid = {18542983}, issn = {0948-6143}, mesh = {Animals ; Crithidia/microbiology/ultrastructure ; DNA, Kinetoplast/*ultrastructure ; DNA, Protozoan/*ultrastructure ; Evolution, Molecular ; Flagella/microbiology/ultrastructure ; Freeze Etching ; Histocytochemistry ; Immunohistochemistry ; Microscopy, Electron, Transmission ; Mitochondrial Membranes/microbiology/ultrastructure ; *Nucleic Acid Conformation ; *Symbiosis ; Trypanosomatina/microbiology/*ultrastructure ; }, abstract = {The endosymbiont-bearing trypanosomatids present a typical kDNA arrangement, which is not well characterized. In the majority of trypanosomatids, the kinetoplast forms a bar-like structure containing tightly packed kDNA fibers. On the contrary, in trypanosomatids that harbor an endosymbiotic bacterium, the kDNA fibers are disposed in a looser arrangement that fills the kinetoplast matrix. In order to shed light on the kinetoplast structural organization in these protozoa, we used cytochemical and immunocytological approaches. Our results showed that in endosymbiont-containing species, DNA and basic proteins are distributed not only in the kDNA network, but also in the kinetoflagellar zone (KFZ), which corresponds to the region between the kDNA and the inner mitochondrial membrane nearest the flagellum. The presence of DNA in the KFZ is in accordance with the actual model of kDNA replication, whereas the detection of basic proteins in this region may be related to the basic character of the intramitochondrial filaments found in this area, which are part of the complex that connects the kDNA to the basal body. The kinetoplast structural organization of Bodo sp. was also analyzed, since this protozoan lacks the highly ordered kDNA-packaging characteristic of trypanosomatid and represents an evolutionary ancestral of the Trypanosomatidae family.}, }
@article {pmid18539347, year = {2008}, author = {Raverdy, S and Foster, JM and Roopenian, E and Carlow, CK}, title = {The Wolbachia endosymbiont of Brugia malayi has an active pyruvate phosphate dikinase.}, journal = {Molecular and biochemical parasitology}, volume = {160}, number = {2}, pages = {163-166}, doi = {10.1016/j.molbiopara.2008.04.014}, pmid = {18539347}, issn = {0166-6851}, mesh = {Amino Acid Sequence ; Animals ; Brugia malayi/*microbiology ; Cloning, Molecular ; Gene Expression ; Molecular Sequence Data ; Phylogeny ; Pyruvate, Orthophosphate Dikinase/genetics/*metabolism ; Sequence Alignment ; Wolbachia/*enzymology/genetics ; }, abstract = {Genome analysis of the glycolytic/gluconeogenic pathway in the Wolbachia endosymbiont from the filarial parasite Brugia malayi (wBm) has revealed that wBm lacks pyruvate kinase (PK) and may instead utilize the enzyme pyruvate phosphate dikinase (PPDK; ATP:pyruvate, orthophosphate phosphotransferase, EC 2.7.9.1). PPDK catalyses the reversible conversion of AMP, PPi and phosphoenolpyruvate (PEP) into ATP, Pi and pyruvate. The glycolytic pathway of most organisms, including mammals, contains exclusively PK for the production of pyruvate from PEP. Therefore, the absence of PPDK in mammals makes the enzyme an attractive Wolbachia drug target. In the present study, we have cloned and expressed an active wBm-PPDK, thereby providing insight into the energy metabolism of the endosymbiont. Our results support the development of wBm-PPDK as a promising new drug target in an anti-symbiotic approach to controlling filarial infection.}, }
@article {pmid18538871, year = {2008}, author = {Keiser, PB and Coulibaly, Y and Kubofcik, J and Diallo, AA and Klion, AD and Traoré, SF and Nutman, TB}, title = {Molecular identification of Wolbachia from the filarial nematode Mansonella perstans.}, journal = {Molecular and biochemical parasitology}, volume = {160}, number = {2}, pages = {123-128}, pmid = {18538871}, issn = {0166-6851}, support = {Z01 AI000512-20/ImNIH/Intramural NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/isolation &amp; purification ; DNA Primers/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genes, rRNA ; Mansonella/genetics/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 5S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Wolbachia/*classification/*genetics/isolation &amp; purification ; }, abstract = {Wolbachiae are bacterial endosymbionts of insects and many filarial nematodes whose products trigger inflammation in filarial infections. The dependence of the parasites on their endosymbionts has also led to the use of antibiotics directed against the Wolbachiae, therapy that has been demonstrated to have a profound salutary effect on filarial infections. The identification of Wolbachiae in Mansonella species has been conclusively shown for Mansonella ozzardi (Mo), but not for Mansonella perstans (Mp). Using primers known to amplify the 16S ribosomal DNA of other filarial Wolbachiae, an identical 1393bp band was found in all samples tested. Sequence analysis of these samples demonstrated a single consensus sequence for Mp Wolbachia 16S rDNA that was most similar to Wolbachia sequences from other filarial nematodes. When aligned with the only other Mansonella Wolbachia sequence (Mo) there were only 8 nucleotide differences in the 1369bp overlapping sequence. Phylogenetic dendrograms, examining the relationship of the Mp Wolbachia to other Wolbachia 16S rDNA, showed that the Wolbachia tracked almost identically to the 5S rRNA of their parasite host. Wolbachia surface protein (WSP) was also demonstrated in protein extracted from Mp-containing whole blood. In advance of a treatment trial of Mp, a method for the quantitation of Mp Wolbachia was developed and used to demonstrate not only a relationship between microfilarial numbers and Wolbachia copy numbers, but also to demonstrate the effect of antibiotic on ridding Mp of Wolbachia.}, }
@article {pmid18507740, year = {2008}, author = {Johnson, LJ}, title = {Selfish genetic elements favor the evolution of a distinction between soma and germline.}, journal = {Evolution; international journal of organic evolution}, volume = {62}, number = {8}, pages = {2122-2124}, doi = {10.1111/j.1558-5646.2008.00433.x}, pmid = {18507740}, issn = {0014-3820}, mesh = {Algorithms ; Animals ; *Biological Evolution ; DNA Transposable Elements/genetics ; Female ; Genes ; Genetics ; Genomics ; Male ; *Models, Genetic ; Models, Theoretical ; Phylogeny ; Selection, Genetic ; Symbiosis ; }, abstract = {Many multicellular organisms have evolved a dedicated germline. This can benefit the whole organism, but its advantages to genetic parasites have not been explored. Here I model the evolutionary success of a selfish element, such as a transposable element or endosymbiont, which is capable of creating or strengthening a germline-soma distinction in a primitively multicellular host, and find that it will always benefit the element to do so. Genes causing germline sequestration can therefore spread in a population even if germline sequestration is maladaptive for the host organism. Costly selfish elements are expected to survive only in sexual populations, so sexual species may experience an additional push toward germline-soma distinction, and hence toward cell differentiation and multicellularity.}, }
@article {pmid18503548, year = {2008}, author = {Nakagawa, S and Takai, K}, title = {Deep-sea vent chemoautotrophs: diversity, biochemistry and ecological significance.}, journal = {FEMS microbiology ecology}, volume = {65}, number = {1}, pages = {1-14}, doi = {10.1111/j.1574-6941.2008.00502.x}, pmid = {18503548}, issn = {0168-6496}, mesh = {Animals ; *Archaea/classification/genetics/growth &amp; development/physiology ; Carbon/metabolism ; *Chemoautotrophic Growth ; Ecosystem ; Gastropoda/microbiology ; Genetic Variation ; Mollusca/microbiology ; Phylogeny ; *Proteobacteria/classification/genetics/growth &amp; development/physiology ; Seawater/*microbiology ; Symbiosis ; }, abstract = {Deep-sea vents support productive ecosystems driven primarily by chemoautotrophs. Chemoautotrophs are organisms that are able to fix inorganic carbon using a chemical energy obtained through the oxidation of reduced compounds. Following the discovery of deep-sea vent ecosystems in 1977, there has been an increasing knowledge that deep-sea vent chemoautotrophs display remarkable physiological and phylogenetic diversity. Cultivation-dependent and -independent studies have led to an emerging view that the majority of deep-sea vent chemoautotrophs have the ability to derive energy from a variety of redox couples other than the conventional sulfur-oxygen couple, and fix inorganic carbon via the reductive tricarboxylic acid cycle. In addition, recent genomic, metagenomic and postgenomic studies have considerably accelerated the comprehensive understanding of molecular mechanisms of deep-sea vent chemoautotrophy, even in yet uncultivable endosymbionts of vent fauna. Genomic analysis also suggested that there are previously unrecognized evolutionary links between deep-sea vent chemoautotrophs and important human/animal pathogens. This review summarizes chemoautotrophy in deep-sea vents, highlighting recent biochemical and genomic discoveries.}, }
@article {pmid18502932, year = {2008}, author = {Lamelas, A and Pérez-Brocal, V and Gómez-Valero, L and Gosalbes, MJ and Moya, A and Latorre, A}, title = {Evolution of the secondary symbiont "Candidatus serratia symbiotica" in aphid species of the subfamily lachninae.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {13}, pages = {4236-4240}, pmid = {18502932}, issn = {1098-5336}, mesh = {Animals ; Aphids/classification/*microbiology ; Buchnera/genetics/isolation &amp; purification/physiology ; *Evolution, Molecular ; Genes, rRNA ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Serratia/classification/*genetics/*physiology ; *Symbiosis ; }, abstract = {Buchnera aphidicola BCc, the primary endosymbiont of the aphid Cinara cedri (subfamily Lachninae), is losing its symbiotic capacity and might be replaced by the coresident "Candidatus Serratia symbiotica." Phylogenetic and morphological analyses within the subfamily Lachninae indicate two different "Ca. Serratia symbiotica" lineages and support the longtime coevolution of both symbionts in C. cedri.}, }
@article {pmid18495345, year = {2008}, author = {Hornok, S and Földvári, G and Elek, V and Naranjo, V and Farkas, R and de la Fuente, J}, title = {Molecular identification of Anaplasma marginale and rickettsial endosymbionts in blood-sucking flies (Diptera: Tabanidae, Muscidae) and hard ticks (Acari: Ixodidae).}, journal = {Veterinary parasitology}, volume = {154}, number = {3-4}, pages = {354-359}, doi = {10.1016/j.vetpar.2008.03.019}, pmid = {18495345}, issn = {0304-4017}, mesh = {Anaplasma marginale/*genetics ; Anaplasmosis/microbiology/transmission ; Animals ; Cattle ; Cattle Diseases/transmission ; Insect Vectors/microbiology ; Ixodidae/*microbiology ; Muscidae/*microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*isolation &amp; purification ; }, abstract = {In an attempt to identify the main vector and possible transmission routes of Anaplasma spp. in a region of Hungary with high prevalence of ovine and bovine anaplasmosis, DNA was extracted from 316 haematophagous arthropods (individually or in pools), including 4 species of ixodid ticks, 6 species of tabanid flies and hornflies. Midichloria-like organisms were identified with PCR (amplifying a portion of the 16S rRNA gene) and sequencing from Dermacentor marginatus and Ixodes ricinus. Significantly higher 16S positive D. marginatus individuals were collected in March than in April, suggesting earlier questing of ticks that contain rickettsial agents (thus endosymbionts). Midichloria- and Wolbachia-like organisms were also found in randomly caught horse flies (Tabanus bovinus and T. tergestinus) as well as hornflies (Haematobia irritans), respectively, with 97-99% similarity to sequences deposited in the GenBank. Although all ticks were negative in the Anaplasma spp.-specific msp4 PCR, four individuals of T. bovinus collected near to grazing cattle were positive for Anaplasma marginale. The results of the present study provide the first molecular evidence for the potential mechanical vector role of T. bovinus in the transmission of A. marginale, and broaden the range of haematophagous arthropods harbouring Midichloria-like bacteria, for the first time in any Dermacentor or Tabanus species.}, }
@article {pmid18493612, year = {2008}, author = {Moustafa, A and Reyes-Prieto, A and Bhattacharya, D}, title = {Chlamydiae has contributed at least 55 genes to Plantae with predominantly plastid functions.}, journal = {PloS one}, volume = {3}, number = {5}, pages = {e2205}, pmid = {18493612}, issn = {1932-6203}, support = {R01 ES013679/ES/NIEHS NIH HHS/United States ; T32 GM008629/GM/NIGMS NIH HHS/United States ; R01ES013679/ES/NIEHS NIH HHS/United States ; }, mesh = {Chlamydia/*genetics ; *Genes, Bacterial ; Plants/genetics/*microbiology ; *Plastids ; }, abstract = {BACKGROUND: The photosynthetic organelle (plastid) originated via primary endosymbiosis in which a phagotrophic protist captured and harnessed a cyanobacterium. The plastid was inherited by the common ancestor of the red, green (including land plants), and glaucophyte algae (together, the Plantae). Despite the critical importance of primary plastid endosymbiosis, its ancient derivation has left behind very few "footprints" of early key events in organelle genesis.<br><br>To gain insights into this process, we conducted an in-depth phylogenomic analysis of genomic data (nuclear proteins) from 17 Plantae species to identify genes of a surprising provenance in these taxa, Chlamydiae bacteria. Previous studies show that Chlamydiae contributed many genes (at least 21 in one study) to Plantae that primarily have plastid functions and were postulated to have played a fundamental role in organelle evolution. Using our comprehensive approach, we identify at least 55 Chlamydiae-derived genes in algae and plants, of which 67% (37/55) are putatively plastid targeted and at least 3 have mitochondrial functions. The remainder of the proteins does not contain a bioinformatically predicted organelle import signal although one has an N-terminal extension in comparison to the Chlamydiae homolog. Our data suggest that environmental Chlamydiae were significant contributors to early Plantae genomes that extend beyond plastid metabolism. The chlamydial gene distribution and protein tree topologies provide evidence for both endosymbiotic gene transfer and a horizontal gene transfer ratchet driven by recurrent endoparasitism as explanations for gene origin.<br><br>CONCLUSIONS/SIGNIFICANCE: Our findings paint a more complex picture of gene origin than can easily be explained by endosymbiotic gene transfer from an organelle-like point source. These data significantly extend the genomic impact of Chlamydiae on Plantae and show that about one-half (30/55) of the transferred genes are most closely related to sequences emanating from the genome of the only environmental isolate that is currently available. This strain, Candidatus Protochlamydia amoebophila UWE25 is an endosymbiont of Acanthamoeba and likely represents the type of endoparasite that contributed the genes to Plantae.}, }
@article {pmid18486691, year = {2008}, author = {McCall, JW and Genchi, C and Kramer, LH and Guerrero, J and Venco, L}, title = {Heartworm disease in animals and humans.}, journal = {Advances in parasitology}, volume = {66}, number = {}, pages = {193-285}, doi = {10.1016/S0065-308X(08)00204-2}, pmid = {18486691}, issn = {0065-308X}, mesh = {Animals ; Cat Diseases/diagnosis/epidemiology/parasitology/prevention &amp; control ; Cats ; Dirofilaria immitis/immunology/*pathogenicity ; *Dirofilariasis/diagnosis/epidemiology/parasitology/prevention &amp; control ; Dog Diseases/diagnosis/epidemiology/parasitology/prevention &amp; control ; Dogs ; Female ; Ferrets ; Filaricides/therapeutic use ; *Host-Parasite Interactions ; Humans ; Male ; Symbiosis ; Wolbachia/growth &amp; development ; }, abstract = {Heartworm disease due to Dirofilaria immitis continues to cause severe disease and even death in dogs and other animals in many parts of the world, even though safe, highly effective and convenient preventatives have been available for the past two decades. Moreover, the parasite and vector mosquitoes continue to spread into areas where they have not been reported previously. Heartworm societies have been established in the USA and Japan and the First European Dirofilaria Days (FEDD) Conference was held in Zagreb, Croatia, in February of 2007. These organizations promote awareness, encourage research and provide updated guidelines for the diagnosis, treatment and prevention of heartworm disease. The chapter begins with a review of the biology and life cycle of the parasite. It continues with the prevalence and distribution of the disease in domestic and wild animals, with emphasis on more recent data on the spreading of the disease and the use of molecular biology techniques in vector studies. The section on pathogenesis and immunology also includes a discussion of the current knowledge of the potential role of the Wolbachia endosymbiont in inflammatory and immune responses to D. immitis infection, diagnostic use of specific immune responses to the bacteria, immunomodulatory activity and antibiotic treatment of infected animals. Canine, feline and ferret heartworm disease are updated with regard to the clinical presentation, diagnosis, prevention, therapy and management of the disease, with special emphasis on the recently described Heartworm Associated Respiratory Disease (HARD) Syndrome in cats. The section devoted to heartworm infection in humans also includes notes on other epizootic filariae, particularly D. repens in humans in Europe. The chapter concludes with a discussion on emerging strategies in heartworm treatment and control, highlighting the potential role of tetracycline antibiotics in adulticidal therapy.}, }
@article {pmid18478288, year = {2008}, author = {Huang, CY and Lee, CY and Wu, HC and Kuo, MH and Lai, CY}, title = {Interactions of chaperonin with a weakly active anthranilate synthase from the aphid endosymbiont Buchnera aphidicola.}, journal = {Microbial ecology}, volume = {56}, number = {4}, pages = {696-703}, pmid = {18478288}, issn = {0095-3628}, mesh = {Animals ; Anthranilate Synthase/genetics/*metabolism ; Aphids/*microbiology ; Bacterial Proteins/genetics/*metabolism ; Buchnera/*enzymology ; Chaperonins/*metabolism ; Escherichia coli/genetics ; Genetic Complementation Test ; Mutation ; Polymerase Chain Reaction ; Protein Binding ; Recombinant Proteins/metabolism ; Symbiosis ; }, abstract = {The endosymbiotic bacterium Buchnera provides its aphid host with essential amino acids. Buchnera is typical of intracellular symbiotic and parasitic microorganisms in having a small effective population size, which is believed to accelerate genetic drift and reduce the stability of gene products. It is hypothesized that Buchnera mitigates protein instability with an increased production of the chaperonins GroESL. In this paper, we report the expression and functional analysis of trpE, a plasmid-borne fast-evolving gene encoding the tryptophan biosynthesis enzyme anthranilate synthase. We overcame the problem of low enzyme stability by using an anthranilate synthase-deficient mutant of E. coli as the expression host and the method of genetic complementation for detection of the enzyme activity. We showed that the Buchnera anthranilate synthase was only weakly active at the temperature of 26 degrees C but became inactive at the higher temperatures of 32 degrees C and 37 degrees C and that the coexpression with chaperonin genes groESL of E. coli enhanced the function of the Buchnera enzyme. These findings are consistent with the proposed role of groESL in the Buchnera-aphid symbiosis.}, }
@article {pmid18478054, year = {2008}, author = {Suh, JM and Stenesen, D and Peters, JM and Inoue, A and Cade, A and Graff, JM}, title = {An RGS-containing sorting nexin controls Drosophila lifespan.}, journal = {PloS one}, volume = {3}, number = {5}, pages = {e2152}, pmid = {18478054}, issn = {1932-6203}, mesh = {5' Untranslated Regions ; Animals ; Animals, Genetically Modified ; Carrier Proteins/chemistry/*physiology ; Drosophila/genetics/*physiology ; Fat Body/physiology ; Larva/physiology ; *Longevity ; Mutation ; Oligopeptides/*chemistry ; Sorting Nexins ; Vesicular Transport Proteins/chemistry/*physiology ; }, abstract = {The pursuit of eternal youth has existed for centuries and recent data indicate that fat-storing tissues control lifespan. In a D. melanogaster fat body insertional mutagenic enhancer trap screen designed to isolate genes that control longevity, we identified a regulator of G protein signaling (RGS) domain containing sorting nexin, termed snazarus (sorting nexin lazarus, snz). Flies with insertions into the 5' UTR of snz live up to twice as long as controls. Transgenic expression of UAS-Snz from the snz Gal4 enhancer trap insertion, active in fat metabolic tissues, rescued lifespan extension. Further, the lifespan extension of snz mutants was independent of endosymbiont, e.g., Wolbachia, effects. Notably, old snz mutant flies remain active and fertile indicating that snz mutants have prolonged youthfulness, a goal of aging research. Since mammals have snz-related genes, it is possible that the functions of the snz family may be conserved to humans.}, }
@article {pmid18474103, year = {2008}, author = {Kim, E and Lane, CE and Curtis, BA and Kozera, C and Bowman, S and Archibald, JM}, title = {Complete sequence and analysis of the mitochondrial genome of Hemiselmis andersenii CCMP644 (Cryptophyceae).}, journal = {BMC genomics}, volume = {9}, number = {}, pages = {215}, pmid = {18474103}, issn = {1471-2164}, mesh = {Algal Proteins/genetics ; Base Composition ; Base Sequence ; Chromosome Mapping ; Codon/genetics ; Cryptophyta/classification/*genetics ; DNA Primers/genetics ; DNA, Algal/chemistry/*genetics ; DNA, Mitochondrial/chemistry/*genetics ; Evolution, Molecular ; *Genome, Mitochondrial ; Models, Molecular ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Algal/chemistry/genetics ; RNA, Transfer/chemistry/genetics ; Repetitive Sequences, Nucleic Acid ; Reverse Transcriptase Polymerase Chain Reaction ; Species Specificity ; }, abstract = {BACKGROUND: Cryptophytes are an enigmatic group of unicellular eukaryotes with plastids derived by secondary (i.e., eukaryote-eukaryote) endosymbiosis. Cryptophytes are unusual in that they possess four genomes-a host cell-derived nuclear and mitochondrial genome and an endosymbiont-derived plastid and 'nucleomorph' genome. The evolutionary origins of the host and endosymbiont components of cryptophyte algae are at present poorly understood. Thus far, a single complete mitochondrial genome sequence has been determined for the cryptophyte Rhodomonas salina. Here, the second complete mitochondrial genome of the cryptophyte alga Hemiselmis andersenii CCMP644 is presented.<br><br>RESULTS: The H. andersenii mtDNA is 60,553 bp in size and encodes 30 structural RNAs and 36 protein-coding genes, all located on the same strand. A prominent feature of the genome is the presence of a approximately 20 Kbp long intergenic region comprised of numerous tandem and dispersed repeat units of between 22-336 bp. Adjacent to these repeats are 27 copies of palindromic sequences predicted to form stable DNA stem-loop structures. One such stem-loop is located near a GC-rich and GC-poor region and may have a regulatory function in replication or transcription. The H. andersenii mtDNA shares a number of features in common with the genome of the cryptophyte Rhodomonas salina, including general architecture, gene content, and the presence of a large repeat region. However, the H. andersenii mtDNA is devoid of inverted repeats and introns, which are present in R. salina. Comparative analyses of the suite of tRNAs encoded in the two genomes reveal that the H. andersenii mtDNA has lost or converted its original trnK(uuu) gene and possesses a trnS-derived 'trnK(uuu)', which appears unable to produce a functional tRNA. Mitochondrial protein coding gene phylogenies strongly support a variety of previously established eukaryotic groups, but fail to resolve the relationships among higher-order eukaryotic lineages.<br><br>CONCLUSION: Comparison of the H. andersenii and R. salina mitochondrial genomes reveals a number of cryptophyte-specific genomic features, most notably the presence of a large repeat-rich intergenic region. However, unlike R. salina, the H. andersenii mtDNA does not possess introns and lacks a Lys-tRNA, which is presumably imported from the cytosol.}, }
@article {pmid18469124, year = {2008}, author = {Kono, M and Koga, R and Shimada, M and Fukatsu, T}, title = {Infection dynamics of coexisting beta- and gammaproteobacteria in the nested endosymbiotic system of mealybugs.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {13}, pages = {4175-4184}, pmid = {18469124}, issn = {1098-5336}, mesh = {Animals ; Betaproteobacteria/classification/genetics/*physiology ; Chaperonin 60/genetics ; Female ; Gammaproteobacteria/classification/genetics/*physiology ; Genes, rRNA ; Hemiptera/growth &amp; development/*microbiology ; Male ; Molecular Sequence Data ; Nymph/genetics/microbiology ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {We investigated the infection dynamics of endosymbiotic bacteria in the developmental course of the mealybugs Planococcus kraunhiae and Pseudococcus comstocki. Molecular phylogenetic analyses identified a betaproteobacterium and a gammaproteobacterium from each of the mealybug species. The former bacterium was related to the beta-endosymbionts of other mealybugs, i.e., "Candidatus Tremblaya princeps," and formed a compact clade in the Betaproteobacteria. Meanwhile, the latter bacterium was related to the gamma-endosymbionts of other mealybugs but belonged to distinct clades in the Gammaproteobacteria. Whole-mount in situ hybridization confirmed the peculiar nested formation in the endosymbiotic system of the mealybugs: the beta-endosymbiont cells were present in the cytoplasm of the bacteriocytes, and the gamma-endosymbiont cells were located in the beta-endosymbiont cells. In nymphal and female development, a large oval bacteriome consisting of a number of bacteriocytes was present in the abdomen, wherein the endosymbionts were harbored. In male development, strikingly, the bacteriome progressively degenerated in prepupae and pupae and became almost unrecognizable in adult males. In the degeneration process, the gamma-endosymbionts disappeared more rapidly than the beta-endosymbionts did. Quantitative PCR analyses revealed that (i) the population dynamics of the endosymbionts in female development reflected the reproductive activity of the insects, (ii) the population dynamics of the endosymbionts were strikingly different between female development and male development, (iii) the endosymbiont populations drastically decreased in male development, and (iv) the gamma-endosymbiont populations decreased more rapidly than the beta-endosymbiont populations in male development. Possible mechanisms underlying the uncoupled regulation of the beta- and gamma-endosymbiont populations are discussed in relation to the establishment and evolution of this unique prokaryote-prokaryote endosymbiotic system.}, }
@article {pmid18468982, year = {2008}, author = {Howe, CJ and Barbrook, AC and Nisbet, RE and Lockhart, PJ and Larkum, AW}, title = {The origin of plastids.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {363}, number = {1504}, pages = {2675-2685}, pmid = {18468982}, issn = {0962-8436}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Electron Transport ; Electron Transport Chain Complex Proteins/genetics/metabolism ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Models, Biological ; Photosynthesis ; Phylogeny ; Plastids/classification/*genetics/*metabolism ; Symbiosis ; }, abstract = {It is generally accepted that plastids first arose by acquisition of photosynthetic prokaryotic endosymbionts by non-photosynthetic eukaryotic hosts. It is also accepted that photosynthetic eukaryotes were acquired on several occasions as endosymbionts by non-photosynthetic eukaryote hosts to form secondary plastids. In some lineages, secondary plastids were lost and new symbionts were acquired, to form tertiary plastids. Most recent work has been interpreted to indicate that primary plastids arose only once, referred to as a 'monophyletic' origin. We critically assess the evidence for this. We argue that the combination of Ockham's razor and poor taxon sampling will bias studies in favour of monophyly. We discuss possible concerns in phylogenetic reconstruction from sequence data. We argue that improved understanding of lineage-specific substitution processes is needed to assess the reliability of sequence-based trees. Improved understanding of the timing of the radiation of present-day cyanobacteria is also needed. We suggest that acquisition of plastids is better described as the result of a process rather than something occurring at a discrete time, and describe the 'shopping bag' model of plastid origin. We argue that dinoflagellates and other lineages provide evidence in support of this.}, }
@article {pmid18461124, year = {2008}, author = {Brennan, LJ and Keddie, BA and Braig, HR and Harris, HL}, title = {The endosymbiont Wolbachia pipientis induces the expression of host antioxidant proteins in an Aedes albopictus cell line.}, journal = {PloS one}, volume = {3}, number = {5}, pages = {e2083}, pmid = {18461124}, issn = {1932-6203}, mesh = {Aedes/*microbiology/*physiology ; Animals ; Bacterial Proteins/genetics/isolation &amp; purification ; Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Flow Cytometry ; *Gene Expression Regulation ; Glutathione Peroxidase/genetics ; Insect Proteins/*genetics/isolation &amp; purification ; Polymerase Chain Reaction ; Reactive Oxygen Species/metabolism ; Rifampin/pharmacology ; Superoxide Dismutase/genetics ; Symbiosis ; Wolbachia/drug effects/genetics/*physiology ; }, abstract = {Wolbachia are obligate intracellular bacteria which commonly infect arthropods. They are maternally inherited and capable of altering host development, sex determination, and reproduction. Reproductive manipulations include feminization, male-killing, parthenogenesis, and cytoplasmic incompatibility. The mechanism by which Wolbachia avoid destruction by the host immune response is unknown. Generation of antimicrobial peptides (AMPs) and reactive oxygen species (ROS) by the host are among the first lines of traditional antimicrobial defense. Previous work shows no link between a Wolbachia infection and the induction of AMPs. Here we compare the expression of protein in a cell line naturally infected with Wolbachia and an identical cell line cured of the infection through the use of antibiotics. Protein extracts of each cell line were analyzed by two dimensional gel electrophoresis and LC/MS/MS. Our results show the upregulation of host antioxidant proteins, which are active against ROS generated by aerobic cell metabolism and during an immune response. Furthermore, flow cytometric and microscopic analysis demonstrates that ROS production is significantly greater in Wolbachia-infected mosquito cells and is associated with endosymbiont-containing vacuoles located in the host cell cytoplasm. This is the first empirical data supporting an association between Wolbachia and the insect antioxidant system.}, }
@article {pmid18460604, year = {2008}, author = {Kreimer, A and Borenstein, E and Gophna, U and Ruppin, E}, title = {The evolution of modularity in bacterial metabolic networks.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {19}, pages = {6976-6981}, pmid = {18460604}, issn = {1091-6490}, support = {R01 GM028016/GM/NIGMS NIH HHS/United States ; GM28016/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacteria/*metabolism ; *Biological Evolution ; *Metabolic Networks and Pathways ; Proteobacteria/metabolism ; }, abstract = {Deciphering the modular organization of metabolic networks and understanding how modularity evolves have attracted tremendous interest in recent years. Here, we present a comprehensive large scale characterization of modularity across the bacterial tree of life, systematically quantifying the modularity of the metabolic networks of >300 bacterial species. Three main determinants of metabolic network modularity are identified. First, network size is an important topological determinant of network modularity. Second, several environmental factors influence network modularity, with endosymbionts and mammal-specific pathogens having lower modularity scores than bacterial species that occupy a wider range of niches. Moreover, even among the pathogens, those that alternate between two distinct niches, such as insect and mammal, tend to have relatively high metabolic network modularity. Third, horizontal gene transfer is an important force that contributes significantly to metabolic modularity. We additionally reconstruct the metabolic network of ancestral bacterial species and examine the evolution of modularity across the tree of life. This reveals a trend of modularity decrease from ancestors to descendants that is likely the outcome of niche specialization and the incorporation of peripheral metabolic reactions.}, }
@article {pmid18458997, year = {2008}, author = {Kageyama, D and Narita, S and Noda, H}, title = {Transfection of feminizing Wolbachia endosymbionts of the butterfly, Eurema hecabe, into the cell culture and various immature stages of the silkmoth, Bombyx mori.}, journal = {Microbial ecology}, volume = {56}, number = {4}, pages = {733-741}, pmid = {18458997}, issn = {0095-3628}, mesh = {Animals ; Bombyx/cytology/genetics/*microbiology ; Butterflies/*microbiology ; Cell Line ; Female ; Male ; Oocytes/metabolism ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {Wolbachia are maternally inherited endosymbiotic bacteria of invertebrates that can manipulate the reproductive systems of their arthropod hosts in a variety of ways. To establish a useful model system for investigating the mechanism of Wolbachia-induced host feminization, we conducted the following series of experiments: (1) feminizing Wolbachia of the butterfly, Eurema hecabe, were transferred into cell cultures of the silkmoth, Bombyx mori, and (2) the transfected Wolbachia in cell cultures were inoculated into B. mori at four immature stages. Wolbachia were successfully transfected into the cell cultures and stably maintained for more than 1 year (>30 passages). However, none of the inoculated insects produced mature oocytes that were Wolbachia-positive. This finding was consistent with the fact that Wolbachia was not detected in individuals in subsequent generations. In contrast, Wolbachia were detected at relatively high frequencies (60-80% of individuals) in the somatic tissues of inoculated insects. Real-time quantitative polymerase chain reaction revealed that the Wolbachia densities in the cultured cells were approximately tenfold higher than those in the native host E. hecabe. Among B. mori individuals inoculated at various developmental stages, those inoculated at early stages exhibited higher Wolbachia densities at the adult stage. The Wolbachia densities in individuals inoculated at the second-instar stage were comparable to those in intact E. hecabe. These results suggest that infection and/or proliferation of Wolbachia in germline cells are actively hindered by regulation in B. mori but feasible in somatic cells and that the Wolbachia densities in somatic tissues are regulated by the living host insects.}, }
@article {pmid18458328, year = {2008}, author = {Robledo, M and Jiménez-Zurdo, JI and Velázquez, E and Trujillo, ME and Zurdo-Piñeiro, JL and Ramírez-Bahena, MH and Ramos, B and Díaz-Mínguez, JM and Dazzo, F and Martínez-Molina, E and Mateos, PF}, title = {Rhizobium cellulase CelC2 is essential for primary symbiotic infection of legume host roots.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {19}, pages = {7064-7069}, pmid = {18458328}, issn = {1091-6490}, mesh = {Cellulase/genetics/isolation &amp; purification/*metabolism ; Cellulose/biosynthesis ; Cloning, Molecular ; Fabaceae/cytology/*microbiology ; Genes, Bacterial ; Genetic Linkage ; Medicago/cytology/microbiology ; Molecular Sequence Data ; Mutation/genetics ; Phenotype ; Plant Roots/cytology/*microbiology ; Rhizobium leguminosarum/cytology/*enzymology/genetics ; Root Nodules, Plant/cytology/microbiology ; Seedlings/microbiology ; *Symbiosis ; }, abstract = {The rhizobia-legume, root-nodule symbiosis provides the most efficient source of biologically fixed ammonia fertilizer for agricultural crops. Its development involves pathways of specificity, infectivity, and effectivity resulting from expressed traits of the bacterium and host plant. A key event of the infection process required for development of this root-nodule symbiosis is a highly localized, complete erosion of the plant cell wall through which the bacterial symbiont penetrates to establish a nitrogen-fixing, intracellular endosymbiotic state within the host. This process of wall degradation must be delicately balanced to avoid lysis and destruction of the host cell. Here, we describe the purification, biochemical characterization, molecular genetic analysis, biological activity, and symbiotic function of a cell-bound bacterial cellulase (CelC2) enzyme from Rhizobium leguminosarum bv. trifolii, the clover-nodulating endosymbiont. The purified enzyme can erode the noncrystalline tip of the white clover host root hair wall, making a localized hole of sufficient size to allow wild-type microsymbiont penetration. This CelC2 enzyme is not active on root hairs of the nonhost legume alfalfa. Microscopy analysis of the symbiotic phenotypes of the ANU843 wild type and CelC2 knockout mutant derivative revealed that this enzyme fulfils an essential role in the primary infection process required for development of the canonical nitrogen-fixing R. leguminosarum bv. trifolii-white clover symbiosis.}, }
@article {pmid18454590, year = {2008}, author = {Portillo, A and Santibáñez, P and Santibáñez, S and Pérez-Martínez, L and Oteo, JA}, title = {Detection of Rickettsia spp. in Haemaphysalis ticks collected in La Rioja, Spain.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {8}, number = {5}, pages = {653-658}, doi = {10.1089/vbz.2007.0272}, pmid = {18454590}, issn = {1557-7759}, mesh = {Animals ; Cattle ; Cattle Diseases/parasitology ; DNA, Bacterial/isolation &amp; purification ; Rickettsia/*isolation &amp; purification ; Sheep ; Sheep Diseases/parasitology ; Spain ; Tick Infestations/epidemiology/veterinary ; Ticks/*microbiology ; }, abstract = {In an attempt to know the potential risk of human disease after exposure to ticks in La Rioja (North of Spain), the objective of our study was to investigate the presence of Rickettsia species in Haemaphysalis ticks collected in our area. A total of 177 Haemaphysalis spp. belonging to three species (H. punctata, H. sulcata, and H. inermis) were subjected to DNA extraction and tested by polymerase chain reaction (PCR) targeting three rickettsial genes: gltA, ompB, and ompA. Six (3 H. inermis, 2 H. punctata, and 1 H. sulcata) of the 177 specimens were found to be infected (3.4%). The rickettsiae in H. inermis ticks (n = 3) were identified as Rickettsia aeschlimannii by sequencing of the genes coding for gltA, ompB, and ompA. Nucleotide sequences from H. punctata and H. sulcata samples that yielded PCR products (n = 3), showed >99% similarity with sequences of Rickettsia endosymbiont of H. sulcata and 'Candidatus Rickettsia hoogstraalii' for gltA and ompB genes, respectively. Attempts to amplify ompA from these two H. punctata and one H. sulcata failed. This study suggests that H. inermis could be a vector for tick-borne spotted fever caused by R. aeschlimannii in the north of Spain. Further studies on characterization and culture of rickettsial endosymbionts found in Haemaphysalis spp. should be performed.}, }
@article {pmid18449191, year = {2008}, author = {Tsaousis, AD and Kunji, ER and Goldberg, AV and Lucocq, JM and Hirt, RP and Embley, TM}, title = {A novel route for ATP acquisition by the remnant mitochondria of Encephalitozoon cuniculi.}, journal = {Nature}, volume = {453}, number = {7194}, pages = {553-556}, doi = {10.1038/nature06903}, pmid = {18449191}, issn = {1476-4687}, support = {MC_U105663139/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Adenosine Triphosphate/*metabolism ; Animals ; Biological Transport ; Carrier Proteins/genetics/immunology/metabolism ; Cell Line ; Encephalitozoon cuniculi/*cytology/genetics/*metabolism ; Escherichia coli/genetics/metabolism ; Fungal Proteins/genetics/immunology/metabolism ; Genome, Fungal/genetics ; Genome, Mitochondrial/genetics ; Mitochondria/genetics/*metabolism ; Models, Biological ; Molecular Sequence Data ; Rabbits ; Rats ; Symbiosis ; }, abstract = {Mitochondria use transport proteins of the eukaryotic mitochondrial carrier family (MCF) to mediate the exchange of diverse substrates, including ATP, with the host cell cytosol. According to classical endosymbiosis theory, insertion of a host-nuclear-encoded MCF transporter into the protomitochondrion was the key step that allowed the host cell to harvest ATP from the enslaved endosymbiont. Notably the genome of the microsporidian Encephalitozoon cuniculi has lost all of its genes for MCF proteins. This raises the question of how the recently discovered microsporidian remnant mitochondrion, called a mitosome, acquires ATP to support protein import and other predicted ATP-dependent activities. The E. cuniculi genome does contain four genes for an unrelated type of nucleotide transporter used by plastids and bacterial intracellular parasites, such as Rickettsia and Chlamydia, to import ATP from the cytosol of their eukaryotic host cells. The inference is that E. cuniculi also uses these proteins to steal ATP from its eukaryotic host to sustain its lifestyle as an obligate intracellular parasite. Here we show that, consistent with this hypothesis, all four E. cuniculi transporters can transport ATP, and three of them are expressed on the surface of the parasite when it is living inside host cells. The fourth transporter co-locates with mitochondrial Hsp70 to the E. cuniculi mitosome. Thus, uniquely among eukaryotes, the traditional relationship between mitochondrion and host has been subverted in E. cuniculi, by reductive evolution and analogous gene replacement. Instead of the mitosome providing the parasite cytosol with ATP, the parasite cytosol now seems to provide ATP for the organelle.}, }
@article {pmid18445834, year = {2008}, author = {Guse, AH}, title = {Back from the dormant stage: second messenger cyclic ADP-ribose essential for Toxoplasma gondii pathogenicity.}, journal = {Science signaling}, volume = {1}, number = {17}, pages = {pe18}, doi = {10.1126/stke.117pe18}, pmid = {18445834}, issn = {1937-9145}, mesh = {Animals ; Calcium/*metabolism ; *Calcium Signaling ; Cyclic ADP-Ribose/metabolism/*physiology ; GTP-Binding Proteins/metabolism ; *Gene Expression Regulation ; Mice ; Models, Biological ; Phosphorylation ; Second Messenger Systems ; Signal Transduction ; Symbiosis ; Toxoplasma/*metabolism/pathogenicity ; }, abstract = {Cyclic adenosine diphosphoribose (cADPR) is an endogenous Ca2+-mobilizing second messenger found in cells of animals, plants, and protozoans. It is formed by a specific class of enzymes, the ADP-ribosyl cyclases. cADPR stimulates Ca2+ release by means of ryanodine receptors located in the sarcoplasmic and endoplasmic reticulum. Recently, a role for cADPR has been demonstrated in the obligate intracellular protozoan pathogen Toxoplasma gondii. In T. gondii, stress conditions evoked synthesis of the plant hormone abscisic acid by the apicoplast, a remnant organelle of an algal endosymbiont of T. gondii. Abscisic acid in turn activated formation of cADPR within T. gondii, resulting in Ca2+ release and secretion of proteins involved in egress of T. gondii from its host cell. Evidence for a synthetic pathway of plant origin was obtained with the ABA synthesis inhibitor fluridone, which antagonized cellular egress and induced differentiation of long-lived semidormant cystic forms of T. gondii. Moreover, fluridone protected mice from toxoplasmosis.}, }
@article {pmid18439691, year = {2008}, author = {Hewitson, JP and Harcus, YM and Curwen, RS and Dowle, AA and Atmadja, AK and Ashton, PD and Wilson, A and Maizels, RM}, title = {The secretome of the filarial parasite, Brugia malayi: proteomic profile of adult excretory-secretory products.}, journal = {Molecular and biochemical parasitology}, volume = {160}, number = {1}, pages = {8-21}, doi = {10.1016/j.molbiopara.2008.02.007}, pmid = {18439691}, issn = {0166-6851}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Blotting, Western ; Brugia malayi/*chemistry ; Chromatography, Liquid ; Computational Biology ; Electrophoresis, Gel, Two-Dimensional ; Filariasis/parasitology ; Galectins/analysis ; Helminth Proteins/*analysis/*metabolism ; Humans ; Macrophage Migration-Inhibitory Factors/analysis ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases/analysis ; Proteome/*analysis/*metabolism ; Proteomics/methods ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; }, abstract = {The secretome of a parasite in its definitive host can be considered to be its genome in trans, to the extent that secreted products encoded by the parasite fulfill their function in the host milieu. The 'extended phenotype' of the filarial parasite, Brugia malayi, is of particular interest because of the evidence that infection results in potent down-modulation of the host immune response. We collected B. malayi 'excretory-secretory' (BES) proteins from adult parasites and using a combination of shotgun LC-MS/MS and 2D gel electrophoresis, identified 80 B. malayi and two host proteins in BES, of which 31 (38%) were detectable in whole worm extract (BmA). Products which were enriched in BES relative to BmA included phosphatidylethanolamine-binding protein (PEB), leucyl aminopeptidase (LAP, homologue of ES-62 from the related filaria Acanthocheilonema viteae), N-acetylglucosaminyltransferase (GlcNAcT) and galectin-1, in addition to the previously described major surface glycoprotein, glutathione peroxidase (gp29, GPX-1) and the cytokine homologue macrophage migration inhibitory factor (MIF-1). One of the most abundant released proteins was triose phosphate isomerase (TPI), yet many other glycolytic enzymes (such as aldolase and GAPDH) were found only in the somatic extract. Among the more prominent novel products identified in BES were a set of 11 small transthyretin-like proteins, and three glutamine-rich-repeat mucin-like proteins. Notably, no evidence was found of any secreted protein corresponding to the genome of the Wolbachia endosymbiont present in B. malayi. Western blotting with anti-phosphorylcholine (PC) monoclonal antibody identified that GlcNAcT, and not the ES-62 homologue, is the major PC-bearing protein in BES, while probing with human filariasis sera showed preferential reactivity to galectin-1 and to processed forms of myotactin. Overall, this analysis demonstrates selective release of a suite of newly identified proteins not previously suspected to be involved at the host-parasite interface, and provides important new perspectives on the biology of the filarial parasite.}, }
@article {pmid18433753, year = {2008}, author = {Bazzocchi, C and Mortarino, M and Grandi, G and Kramer, LH and Genchi, C and Bandi, C and Genchi, M and Sacchi, L and McCall, JW}, title = {Combined ivermectin and doxycycline treatment has microfilaricidal and adulticidal activity against Dirofilaria immitis in experimentally infected dogs.}, journal = {International journal for parasitology}, volume = {38}, number = {12}, pages = {1401-1410}, doi = {10.1016/j.ijpara.2008.03.002}, pmid = {18433753}, issn = {1879-0135}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Antigens, Helminth/immunology ; Dirofilaria immitis/*drug effects/immunology ; Dirofilariasis/*drug therapy/immunology ; Dog Diseases/drug therapy ; Dogs ; Doxycycline/immunology/*therapeutic use ; Filaricides/immunology/*therapeutic use ; Immunohistochemistry ; Ivermectin/*therapeutic use ; Microfilariae/isolation &amp; purification ; Polymerase Chain Reaction ; Wolbachia/drug effects/isolation &amp; purification ; }, abstract = {There is still a pressing need for effective adulticide treatment for human and animal filarial infections. Like many filarial nematodes, Dirofilaria immitis, the causative agent of canine heartworm disease, harbours the bacterial endosymbiont Wolbachia, which has been shown to be essential for worm development, fecundity and survival. Here the authors report the effect of different treatment regimens in dogs experimentally infected with adult D. immitis on microfilariemia, antigenemia, worm recovery and Wolbachia content. Treatment with ivermectin (IVM; 6 microg/kg per os weekly) combined with doxycycline (DOXY; 10 mg/kg/day orally from Weeks 0-6, 10-12, 16-18, 22-26 and 28-34) resulted in a significantly faster decrease of circulating microfilariae and higher adulticidal activity compared with either IVM or DOXY alone. Quantitative PCR analysis of ftsZ (Wolbachia DNA) and 18S rDNA (nematode DNA) absolute copy numbers showed significant decreases in Wolbachia content compared with controls in worms recovered from DOXY-treated dogs that were not, however, associated with worm death. Worms from IVM/DOXY-treated dogs, on the other hand, had Wolbachia/nematode DNA ratios similar to those of control worms, suggesting a loss of both Wolbachia and nematode DNA as indicated by absolute copy number values. Histology and transmission electron microscopy of worms recovered from the IVM/DOXY combination group showed complete loss of uterine content in females and immunohistochemistry for Wolbachia was negative. Results indicate that the combination of these two drugs causes adult worm death. This could have important implications for control of human and animal filarial infections.}, }
@article {pmid18433492, year = {2008}, author = {Gross, J and Meurer, J and Bhattacharya, D}, title = {Evidence of a chimeric genome in the cyanobacterial ancestor of plastids.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {117}, pmid = {18433492}, issn = {1471-2148}, mesh = {Chimera ; Cyanobacteria/*genetics/metabolism ; Evolution, Molecular ; *Gene Transfer, Horizontal ; *Genome, Bacterial ; *Genome, Plastid ; Markov Chains ; Monte Carlo Method ; Photosystem I Protein Complex/genetics ; Phylogeny ; Plastids/*genetics ; Rhodophyta/*genetics/metabolism ; }, abstract = {BACKGROUND: Horizontal gene transfer (HGT) is a vexing fact of life for microbial phylogeneticists. Given the substantial rates of HGT observed in modern-day bacterial chromosomes, it is envisaged that ancient prokaryotic genomes must have been similarly chimeric. But where can one find an ancient prokaryotic genome that has maintained its ancestral condition to address this issue? An excellent candidate is the cyanobacterial endosymbiont that was harnessed over a billion years ago by a heterotrophic protist, giving rise to the plastid. Genetic remnants of the endosymbiont are still preserved in plastids as a highly reduced chromosome encoding 54 - 264 genes. These data provide an ideal target to assess genome chimericism in an ancient cyanobacterial lineage.<br><br>RESULTS: Here we demonstrate that the origin of the plastid-encoded gene cluster for menaquinone/phylloquinone biosynthesis in the extremophilic red algae Cyanidiales contradicts a cyanobacterial genealogy. These genes are relics of an ancestral cluster related to homologs in Chlorobi/Gammaproteobacteria that we hypothesize was established by HGT in the progenitor of plastids, thus providing a 'footprint' of genome chimericism in ancient cyanobacteria. In addition to menB, four components of the original gene cluster (menF, menD, menC, and menH) are now encoded in the nuclear genome of the majority of non-Cyanidiales algae and plants as the unique tetra-gene fusion named PHYLLO. These genes are monophyletic in Plantae and chromalveolates, indicating that loci introduced by HGT into the ancestral cyanobacterium were moved over time into the host nucleus.<br><br>CONCLUSION: Our study provides unambiguous evidence for the existence of genome chimericism in ancient cyanobacteria. In addition we show genes that originated via HGT in the cyanobacterial ancestor of the plastid made their way to the host nucleus via endosymbiotic gene transfer (EGT).}, }
@article {pmid18430636, year = {2008}, author = {Keeling, PJ and Archibald, JM}, title = {Organelle evolution: what's in a name?.}, journal = {Current biology : CB}, volume = {18}, number = {8}, pages = {R345-7}, doi = {10.1016/j.cub.2008.02.065}, pmid = {18430636}, issn = {0960-9822}, mesh = {Animals ; *Biological Evolution ; Cyanobacteria/genetics ; Eukaryota/genetics/*microbiology ; Genome, Bacterial ; Genome, Plastid ; Organelles/*genetics ; Symbiosis/*physiology ; }, abstract = {Plastids are organelles derived from cyanobacterial endosymbionts and the evolutionary process that gave rise to them is well understood. Or is it? The complete genome sequence of a recently evolved photosynthetic body in Paulinella chromatophora is cause for reflection on the distinction between 'endosymbiont' and 'organelle', and how the boundaries between these terms can blur.}, }
@article {pmid18410406, year = {2008}, author = {Pankewitz, F and Hilker, M}, title = {Polyketides in insects: ecological role of these widespread chemicals and evolutionary aspects of their biogenesis.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {83}, number = {2}, pages = {209-226}, doi = {10.1111/j.1469-185X.2008.00040.x}, pmid = {18410406}, issn = {1464-7931}, mesh = {Animals ; Fatty Acid Synthases/metabolism ; Fungi/*enzymology ; Insecta/*microbiology ; Macrolides/*metabolism ; Polyketide Synthases/*metabolism ; Symbiosis/physiology ; }, abstract = {Polyketides are known to be used by insects for pheromone communication and defence against enemies. Although in microorganisms (fungi, bacteria) and plants polyketide biogenesis is known to be catalysed by polyketide synthases (PKS), no insect PKS involved in biosynthesis of pheromones or defensive compounds have yet been found. Polyketides detected in insects may also be biosynthesized by endosymbionts. From a chemical perspective, polyketide biogenesis involves the formation of a polyketide chain using carboxylic acids as precursors. Fatty acid biosynthesis also requires carboxylic acids as precursors, but utilizes fatty acid synthases (FAS) to catalyse this process. In the present review, studies of the biosynthesis of insect polyketides applying labelled carboxylic acids as precursors are outlined to exemplify chemical approaches used to elucidate insect polyketide formation. However, since compounds biosynthesised by FAS may use the same precursors, it still remains unclear whether the structures that are formed from e.g. acetate chains (acetogenins) or propanoate chains (propanogenins) are PKS or FAS products. A critical comparison of PKS and FAS architectures and activities supports the hypothesis of a common evolutionary origin of these enzyme complexes and highlights why PKS can catalyse the biosynthesis of much more complex products than can FAS. Finally, we summarise knowledge which might assist researchers in designing approaches for the detection of insect PKS genes.}, }
@article {pmid18408062, year = {2008}, author = {Harmer, TL and Rotjan, RD and Nussbaumer, AD and Bright, M and Ng, AW and DeChaine, EG and Cavanaugh, CM}, title = {Free-living tube worm endosymbionts found at deep-sea vents.}, journal = {Applied and environmental microbiology}, volume = {74}, number = {12}, pages = {3895-3898}, pmid = {18408062}, issn = {1098-5336}, mesh = {Animals ; Bacteria/*classification/*isolation &amp; purification ; Bacterial Physiological Phenomena ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Helminths/*microbiology/physiology ; Hot Springs/*microbiology ; In Situ Hybridization, Fluorescence ; Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Recent evidence suggests that deep-sea vestimentiferan tube worms acquire their endosymbiotic bacteria from the environment each generation; thus, free-living symbionts should exist. Here, free-living tube worm symbiont phylotypes were detected in vent seawater and in biofilms at multiple deep-sea vent habitats by PCR amplification, DNA sequence analysis, and fluorescence in situ hybridization. These findings support environmental transmission as a means of symbiont acquisition for deep-sea tube worms.}, }
@article {pmid18402145, year = {2008}, author = {Steiner, FE and Pinger, RR and Vann, CN and Grindle, N and Civitello, D and Clay, K and Fuqua, C}, title = {Infection and co-infection rates of Anaplasma phagocytophilum variants, Babesia spp., Borrelia burgdorferi, and the rickettsial endosymbiont in Ixodes scapularis (Acari: Ixodidae) from sites in Indiana, Maine, Pennsylvania, and Wisconsin.}, journal = {Journal of medical entomology}, volume = {45}, number = {2}, pages = {289-297}, doi = {10.1603/0022-2585(2008)45[289:iacroa]2.0.co;2}, pmid = {18402145}, issn = {0022-2585}, mesh = {Anaplasma phagocytophilum/classification/genetics/*isolation &amp; purification ; Animals ; Babesia/genetics/*isolation &amp; purification ; Borrelia burgdorferi/genetics/*isolation &amp; purification ; Female ; Great Lakes Region ; Ixodes/*microbiology ; Maine ; Male ; Polymerase Chain Reaction ; Rickettsia/genetics/*isolation &amp; purification ; Symbiosis/physiology ; Tick-Borne Diseases/transmission ; }, abstract = {In total, 394 questing adult blacklegged ticks, Ixodes scapularis Say (Acari: Ixodidae), collected at four sites were analyzed by polymerase chain reaction (PCR) for five microbial species: Anaplasma phagocytophilum, Babesia microti, Babesia odocoilei, Borrelia burgdorferi, and the rickettsial I. scapularis endosymbiont. Identities of genetic variants of A. phagocytophilum were determined by sequencing a portion of the 16S DNA. In 55% of infected ticks (193/351), a single agent was detected. In 45% (158/351), two or more agents were detected; 37% harbored two agents and 8% harbored three agents. One male tick, collected from Ft. McCoy, WI, harbored all four microbial genera The highest rates of co-infection were by the Ixodes endosymbiont and B. burgdorferi (95/351). Two species of Babesia co-occurred within a single tick population in Wells National Estuarine Research Reserve, Wells, ME, whereas only B. odocoilei was found in other tick populations. Only A. phagocytophilum human anaplasmosis variant was detected in questing ticks from Tippecanoe River State Park, IN; from Wells; and Ft. McCoy, whereas a single infected tick from Presque Isle, PA, was infected by AP-Variant 1. Partially engorged ticks from deer in Tippecanoe River State Park were all infected with AP-Variant 1. Frequency of infections with each agent varied among populations. Rates and types of co-infections were not significantly different from random except for the Ixodes endosymbiont and B. burgdorferi in male ticks, which co-occurred less frequently than expected. Thus, I. scapularis hosts an array of pathogenic and symbiotic agents and potential evidence of interactions among microbial species was observed.}, }
@article {pmid18400995, year = {2008}, author = {Thornhill, DJ and Wiley, AA and Campbell, AL and Bartol, FF and Teske, A and Halanych, KM}, title = {Endosymbionts of Siboglinum fiordicum and the phylogeny of bacterial endosymbionts in Siboglinidae (Annelida).}, journal = {The Biological bulletin}, volume = {214}, number = {2}, pages = {135-144}, doi = {10.2307/25066670}, pmid = {18400995}, issn = {0006-3185}, mesh = {Animals ; DNA, Ribosomal/*genetics ; Gammaproteobacteria/classification/*genetics ; Microdissection ; *Phylogeny ; Polychaeta/*microbiology ; Symbiosis/*genetics ; }, abstract = {Siboglinid worms are a group of gutless marine annelids that are nutritionally dependent upon endosymbiotic bacteria. Four major groups of siboglinids are known-vestimentiferans, moniliferans, Osedax spp. and frenulates. Although endosymbionts of vestimentiferans and Osedax spp. have been previously characterized, little is currently known about endosymbiotic bacteria associated with frenulate and moniliferan siboglinids. This is particularly surprising given that frenulates are the most diverse and widely distributed group of siboglinids. Here, we molecularly characterize endosymbiotic bacteria associated with the frenulate siboglinid Siboglinum fiordicum by using 16S rDNA ribotyping in concert with laser-capture microdissection (LCM). Phylogenetic analysis indicates that at least three major clades of endosymbiotic gamma-proteobacteria associate with siboglinid annelids, with each clade corresponding to a major siboglinid group. S. fiordicum endosymbionts are a group of gamma-proteobacteria that are divergent from bacteria associated with vestimentiferan or Osedax hosts. Interestingly, symbionts of S. fiordicum, from Norway, are most closely related to symbionts of the frenulate Oligobrachia mashikoi from Japan, suggesting that symbionts of frenulates may share common evolutionary history or metabolic features.}, }
@article {pmid18399908, year = {2008}, author = {Partida-Martinez, LP and Bandemer, S and Rüchel, R and Dannaoui, E and Hertweck, C}, title = {Lack of evidence of endosymbiotic toxin-producing bacteria in clinical Rhizopus isolates.}, journal = {Mycoses}, volume = {51}, number = {3}, pages = {266-269}, doi = {10.1111/j.1439-0507.2007.01477.x}, pmid = {18399908}, issn = {1439-0507}, mesh = {Burkholderia/genetics/growth &amp; development/*physiology ; DNA, Fungal/analysis ; DNA, Ribosomal ; Humans ; Mycotoxins/chemistry/*metabolism ; RNA, Ribosomal, 16S/analysis/genetics ; Rhizopus/growth &amp; development/*physiology ; Symbiosis ; Zygomycosis/epidemiology/*microbiology ; }, abstract = {Infections by Rhizopus spp. account for about 90% of zygomycoses, many of which are lethal in immunocompromised patients. We recently noted that several strains of Rhizopus microsporus harbour rare bacterial endosymbionts (Burkholderia sp.) for the production of 'mycotoxins', which might play a role as virulence factors in human Rhizopus infections. In this study eight clinical Rhizopus spp. isolates have been investigated for the presence of toxin-producing bacterial endosymbionts. By metabolomic data, PCR targeting bacterial 16S rDNA and microscopic investigations with fluorescence dyes we provide three lines of evidence showing that the fungal strains are not associated with endofungal bacteria. Consequently, toxin-producing bacteria are not essential for Rhizopus infections and the development of zygomycoses in humans.}, }
@article {pmid18397952, year = {2008}, author = {Khan, H and Archibald, JM}, title = {Lateral transfer of introns in the cryptophyte plastid genome.}, journal = {Nucleic acids research}, volume = {36}, number = {9}, pages = {3043-3053}, pmid = {18397952}, issn = {1362-4962}, mesh = {Algal Proteins/classification/genetics ; Base Sequence ; Cryptophyta/*genetics ; *Gene Transfer, Horizontal ; Genetic Variation ; *Genome, Plastid ; *Introns ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA Splicing ; }, abstract = {Cryptophytes are unicellular eukaryotic algae that acquired photosynthesis secondarily through the uptake and retention of a red-algal endosymbiont. The plastid genome of the cryptophyte Rhodomonas salina CCMP1319 was recently sequenced and found to contain a genetic element similar to a group II intron. Here, we explore the distribution, structure and function of group II introns in the plastid genomes of distantly and closely related cryptophytes. The predicted secondary structures of six introns contained in three different genes were examined and found to be generally similar to group II introns but unusually large in size (including the largest known noncoding intron). Phylogenetic analysis suggests that the cryptophyte group II introns were acquired via lateral gene transfer (LGT) from a euglenid-like species. Unexpectedly, the six introns occupy five distinct genomic locations, suggesting multiple LGT events or recent transposition (or both). Combined with structural considerations, RT-PCR experiments suggest that the transferred introns are degenerate 'twintrons' (i.e. nested group II/group III introns) in which the internal intron has lost its splicing capability, resulting in an amalgamation with the outer intron.}, }
@article {pmid18397288, year = {2008}, author = {Galvez Rojas, RL and Frossard, ML and Machado Motta, MC and Silber, AM}, title = {L-Proline uptake in Crithidia deanei is influenced by its endosymbiont bacterium.}, journal = {FEMS microbiology letters}, volume = {283}, number = {1}, pages = {15-22}, doi = {10.1111/j.1574-6968.2008.01125.x}, pmid = {18397288}, issn = {0378-1097}, mesh = {Animals ; Antimycin A/analogs &amp; derivatives/pharmacology ; Bacteria/metabolism ; Crithidia/*metabolism/*microbiology ; Culture Media ; DNA, Bacterial/analysis ; Depression, Chemical ; Hydrogen-Ion Concentration ; Monensin/pharmacology ; Potassium/metabolism ; Proline/*metabolism ; RNA, Ribosomal, 16S/analysis ; Rotenone/pharmacology ; Sodium/metabolism ; *Symbiosis ; Temperature ; Time Factors ; Up-Regulation ; Valinomycin/pharmacology ; }, abstract = {Crithidia deanei, a monoxenic trypanosomatid, presents an endosymbiotic bacterium in its cytoplasm. Both the protozoan and the bacterium maintain intensive metabolic exchange, resulting in an interesting model to study the coevolution of metabolisms. The relevance of l-proline for the growth of C. deanei and its transport into these cells was studied. Both the endosymbiont-containing (wild) and the endosymbiont-free protozoa (aposymbiont or cured) strains, when grown in medium supplemented with l-proline, reached higher cell densities than those grown in unsupplemented media. We biochemically characterized the uptake of l-proline in both the wild (K(m)=0.153+/-0.022 mM, V(max)=0.239+/-0.011 nmol min(-1) per 4 x 10(7) cells) and the aposymbiont strains (K(m)=0.177+/-0.049 mM, V(max)=0.132+/-0.012 nmol min(-1) per 4 x 10(7) cells). These data suggest a single type of proline transporter whose activity is upregulated by the presence of the symbiotic bacterium. Proline transport was further characterized and was found to be insensitive to the extracellular concentration of Na+, but sensitive to K+ and pH. The abolition of proline uptake by respiratory chain inhibitors and valinomycin indicates that the proline transport in C. deanei is dependent on the plasma membrane K+ gradient.}, }
@article {pmid18396388, year = {2008}, author = {Dyková, I and Fiala, I and Pecková, H}, title = {Neoparamoeba spp. and their eukaryotic endosymbionts similar to Perkinsela amoebae (Hollande, 1980): coevolution demonstrated by SSU rRNA gene phylogenies.}, journal = {European journal of protistology}, volume = {44}, number = {4}, pages = {269-277}, doi = {10.1016/j.ejop.2008.01.004}, pmid = {18396388}, issn = {0932-4739}, mesh = {Animals ; Eukaryota/*classification/*genetics ; *Phylogeny ; RNA Splicing ; RNA, Protozoan/*genetics ; RNA, Ribosomal/*genetics ; Symbiosis/genetics ; }, abstract = {The molecular phylogeny of Neoparamoeba spp. based on SSU rDNA was updated by including new sequences of strains isolated from an invertebrate and an alga. In total, 59 sequences of strains representating N. pemaquidensis, N. branchiphila, N. aestuarina and N. perurans were analysed. Sequences of SSU rDNA of eukaryotic endosymbionts (Perkinsela amoebae-like organisms) were prepared from 34 samples of genomic DNA of strain-representatives of N. pemaquidensis, N. branchiphila and N. aestuarina. Comparison of phylograms reconstructed from corresponding SSU rDNA sequences of host amoebae and their symbionts revealed a high level of congruence, which argues very strongly for coevolution of these two eukaryotic organisms.}, }
@article {pmid18396164, year = {2008}, author = {Inoue, K and Tsukuda, K and Koito, T and Miyazaki, Y and Hosoi, M and Kado, R and Miyazaki, N and Toyohara, H}, title = {Possible role of a taurine transporter in the deep-sea mussel Bathymodiolus septemdierum in adaptation to hydrothermal vents.}, journal = {FEBS letters}, volume = {582}, number = {10}, pages = {1542-1546}, doi = {10.1016/j.febslet.2008.03.052}, pmid = {18396164}, issn = {0014-5793}, mesh = {*Acclimatization ; Amino Acid Sequence ; Animals ; Anura ; Biological Transport ; Cloning, Molecular ; Conserved Sequence ; DNA, Complementary/genetics ; Membrane Glycoproteins/genetics/*metabolism ; Membrane Transport Proteins/genetics/*metabolism ; Molecular Sequence Data ; Mytilidae/genetics/metabolism/*physiology ; Oocytes/metabolism ; RNA, Messenger/metabolism ; Taurine/*metabolism ; Tissue Distribution ; }, abstract = {Various invertebrates inhabiting hydrothermal vents possess sulfur-oxidizing bacteria in their tissues; however, the mechanisms by which toxic sulfides are delivered to these endosymbionts remain unknown. Recently, detoxification of sulfides using thiotaurine, a sulfur-containing amino acid, has been suggested. In this study, we propose the involvement of a taurine transporter in sulfide detoxification in the deep-sea mussel Bathymodiolus septemdierum by demonstrating: (i) the abundance of its mRNA in the gill; (ii) its activity under a wide range of salinities; (iii) its low Michaelis constant value in taurine transportation; and (iv) its affinity for thiotaurine and the thiotaurine precursor, hypotaurine.}, }
@article {pmid18393999, year = {2008}, author = {Allen, JW and Jackson, AP and Rigden, DJ and Willis, AC and Ferguson, SJ and Ginger, ML}, title = {Order within a mosaic distribution of mitochondrial c-type cytochrome biogenesis systems?.}, journal = {The FEBS journal}, volume = {275}, number = {10}, pages = {2385-2402}, doi = {10.1111/j.1742-4658.2008.06380.x}, pmid = {18393999}, issn = {1742-464X}, support = {BB/C508118/1//Biotechnology and Biological Sciences Research Council/United Kingdom ; //Wellcome Trust/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/genetics/metabolism ; Computational Biology ; Cysteine/chemistry/metabolism ; Cytochromes c/*biosynthesis/chemistry/genetics ; Cytochromes c1/*biosynthesis/chemistry/genetics ; Eukaryotic Cells/classification/physiology ; Evolution, Molecular ; Heme/chemistry/metabolism ; Lyases/genetics/metabolism ; Mitochondria/*metabolism ; Molecular Sequence Data ; Molecular Structure ; Phylogeny ; Plant Proteins/genetics/metabolism ; }, abstract = {Mitochondrial cytochromes c and c(1) are present in all eukaryotes that use oxygen as the terminal electron acceptor in the respiratory chain. Maturation of c-type cytochromes requires covalent attachment of the heme cofactor to the protein, and there are at least five distinct biogenesis systems that catalyze this post-translational modification in different organisms and organelles. In this study, we use biochemical data, comparative genomic and structural bioinformatics investigations to provide a holistic view of mitochondrial c-type cytochrome biogenesis and its evolution. There are three pathways for mitochondrial c-type cytochrome maturation, only one of which is present in prokaryotes. We analyze the evolutionary distribution of these biogenesis systems, which include the Ccm system (System I) and the enzyme heme lyase (System III). We conclude that heme lyase evolved once and, in many lineages, replaced the multicomponent Ccm system (present in the proto-mitochondrial endosymbiont), probably as a consequence of lateral gene transfer. We find no evidence of a System III precursor in prokaryotes, and argue that System III is incompatible with multi-heme cytochromes common to bacteria, but absent from eukaryotes. The evolution of the eukaryotic-specific protein heme lyase is strikingly unusual, given that this protein provides a function (thioether bond formation) that is also ubiquitous in prokaryotes. The absence of any known c-type cytochrome biogenesis system from the sequenced genomes of various trypanosome species indicates the presence of a third distinct mitochondrial pathway. Interestingly, this system attaches heme to mitochondrial cytochromes c that contain only one cysteine residue, rather than the usual two, within the heme-binding motif. The isolation of single-cysteine-containing mitochondrial cytochromes c from free-living kinetoplastids, Euglena and the marine flagellate Diplonema papillatum suggests that this unique form of heme attachment is restricted to, but conserved throughout, the protist phylum Euglenozoa.}, }
@article {pmid18387836, year = {2008}, author = {Bettencourt, R and Dando, P and Rosa, D and Riou, V and Colaço, A and Sarrazin, J and Sarradin, PM and Santos, RS}, title = {Changes of gill and hemocyte-related bio-indicators during long term maintenance of the vent mussel Bathymodiolus azoricus held in aquaria at atmospheric pressure.}, journal = {Comparative biochemistry and physiology. Part A, Molecular &amp; integrative physiology}, volume = {150}, number = {1}, pages = {1-7}, doi = {10.1016/j.cbpa.2008.02.020}, pmid = {18387836}, issn = {1531-4332}, mesh = {Animals ; Bivalvia/*anatomy &amp; histology/*metabolism ; Carbohydrates/biosynthesis ; Gills/*anatomy &amp; histology/*metabolism ; Hemocytes/*cytology/*metabolism ; Phagocytosis ; Pressure ; Time Factors ; }, abstract = {The deep-sea hydrothermal vent mussel Bathymodiolus azoricus has been the subject of several studies aimed at understanding the physiological adaptations that vent animals have developed in order to cope with the particular physical and chemical conditions of hydrothermal environments. In spite of reports describing successful procedures to maintain vent mussels under laboratory conditions at atmospheric pressure, few studies have described the mussel's physiological state after a long period in aquaria. In the present study, we investigate changes in mucocytes and hemocytes in B. azoricus over the course of several months after deep-sea retrieval. The visualization of granules of mucopolysaccharide or glycoprotein was made possible through their inherent auto-fluorescent property and the Alcian blue-Periodic Acid Schiff staining method. The density and distribution of droplets of mucus-like granules was observed at the ventral end of lamellae during acclimatization period. The mucus-like granules were greatly reduced after 3 months and nearly absent after 6 months of aquarium conditions. Additionally, we examined the depletion of endosymbiont bacteria from gill tissues, which typically occurs within a few weeks in sea water under laboratory conditions. The physiological state of B. azoricus after 6 months of acclimatization was also examined by means of phagocytosis assays using hemocytes. Hemocytes from mussels held in aquaria up to 6 months were still capable of phagocytosis but to a lesser extent when compared to the number of ingested yeast particles per phagocytic hemocytes from freshly collected vent mussels. We suggest that the changes in gill mucopolysaccharides and hemocyte glycoproteins, the endosymbiont abundance in gill tissues and phagocytosis are useful health criteria to assess long term maintenance of B. azoricus in aquaria. Furthermore, the laboratory set up to which vent mussels were acclimatized is an applicable system to study physiological reactions such as hemocyte immunocompetence even in the absence of the high hydrostatic pressure found at deep-sea vent sites.}, }
@article {pmid18387819, year = {2008}, author = {Kurz, M and Iturbe-Ormaetxe, I and Jarrott, R and Cowieson, N and Robin, G and Jones, A and King, GJ and Frei, P and Glockshuber, R and O'Neill, SL and Heras, B and Martin, JL}, title = {Cloning, expression, purification and characterization of a DsbA-like protein from Wolbachia pipientis.}, journal = {Protein expression and purification}, volume = {59}, number = {2}, pages = {266-273}, doi = {10.1016/j.pep.2008.02.008}, pmid = {18387819}, issn = {1096-0279}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*biosynthesis/*chemistry/isolation &amp; purification ; Cloning, Molecular ; Escherichia coli/genetics ; Molecular Sequence Data ; Protein Disulfide-Isomerases/*biosynthesis/*chemistry/isolation &amp; purification ; Sequence Alignment ; Wolbachia/*enzymology/genetics ; }, abstract = {Wolbachia pipientis are obligate endosymbionts that infect a wide range of insect and other arthropod species. They act as reproductive parasites by manipulating the host reproduction machinery to enhance their own transmission. This unusual phenotype is thought to be a consequence of the actions of secreted Wolbachia proteins that are likely to contain disulfide bonds to stabilize the protein structure. In bacteria, the introduction or isomerization of disulfide bonds in proteins is catalyzed by Dsb proteins. The Wolbachia genome encodes two proteins, alpha-DsbA1 and alpha-DsbA2, that might catalyze these steps. In this work we focussed on the 234 residue protein alpha-DsbA1; the gene was cloned and expressed in Escherichia coli, the protein was purified and its identity confirmed by mass spectrometry. The sequence identity of alpha-DsbA1 for both dithiol oxidants (E. coli DsbA, 12%) and disulfide isomerases (E. coli DsbC, 14%) is similar. We therefore sought to establish whether alpha-DsbA1 is an oxidant or an isomerase based on functional activity. The purified alpha-DsbA1 was active in an oxidoreductase assay but had little isomerase activity, indicating that alpha-DsbA1 is DsbA-like rather than DsbC-like. This work represents the first successful example of the characterization of a recombinant Wolbachia protein. Purified alpha-DsbA1 will now be used in further functional studies to identify protein substrates that could help explain the molecular basis for the unusual Wolbachia phenotypes, and in structural studies to explore its relationship to other disulfide oxidoreductase proteins.}, }
@article {pmid18386064, year = {2008}, author = {Jacob, J and Mitreva, M and Vanholme, B and Gheysen, G}, title = {Exploring the transcriptome of the burrowing nematode Radopholus similis.}, journal = {Molecular genetics and genomics : MGG}, volume = {280}, number = {1}, pages = {1-17}, pmid = {18386064}, issn = {1617-4615}, support = {AI 46593/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Databases, Genetic ; *Gene Expression Profiling ; Genes, Helminth/physiology ; Host-Parasite Interactions/genetics ; Nematoda/*genetics ; RNA, Helminth/genetics/physiology ; RNA, Small Interfering/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Wolbachia/genetics ; }, abstract = {Radopholus similis is an important nematode pest on fruit crops in the tropics. Unraveling the transcriptome of this migratory plant-parasitic nematode can provide insight in the parasitism process and lead to more efficient control measures. For the first high throughput molecular characterization of this devastating nematode, 5,853 expressed sequence tags from a mixed stage population were generated. Adding 1,154 tags from the EST division of GenBank for subsequent analysis, resulted in a total of 7,007 ESTs, which represent approximately 3,200 genes. The mean G + C content of the nucleotides at the third codon position (GC3%) was calculated to be as high as 64.8%, the highest for nematodes reported to date. BLAST-searches resulted in about 70% of the clustered ESTs having homology to (DNA and protein) sequences from the GenBank database, whereas one-third of them did not match to any known sequence. Roughly 40% of these latter sequences are predicted to be coding, representing putative novel protein coding genes. Functional annotation of the sequences by GO annotation revealed the abundance of genes involved in reproduction and development, which reflects the nematode population biology. Genes with a role in the parasitism process are identified, as well as genes essential for nematode survival, providing information useful for parasite control. No evidence was found for the presence of trans-spliced leader sequences commonly occurring in nematodes, despite the use of various approaches. In conclusion, we found three different sources for the EST sequences: the majority has a nuclear origin, approximately 1% of the EST sequences are derived from the mitochondrial transcriptome, and interestingly, 1% of the tags are with high probability derived from Wolbachia, providing the first molecular indication for the presence of this endosymbiont in a plant-parasitic nematode.}, }
@article {pmid18377816, year = {2008}, author = {Klion, AD}, title = {Filarial infections in travelers and immigrants.}, journal = {Current infectious disease reports}, volume = {10}, number = {1}, pages = {50-57}, pmid = {18377816}, issn = {1523-3847}, abstract = {Filarial infections including loiasis, onchocerciasis, and lymphatic filariasis are important causes of morbidity in endemic populations worldwide, and they present a risk to travelers to endemic areas. Definitive diagnosis is complicated by overlap in the geographic distribution and clinical manifestations of the different filarial parasites, as well as similarities in their antigenic and nucleic acid composition. This has important implications for treatment, because the efficacies and toxicities of available antifilarial agents differ dramatically among filarial species. Recent advances, including the visualization of adult filarial worms in vivo by high-frequency ultrasound and the identification of the bacterial endosymbiont, Wolbachia, have greatly improved our understanding of the pathogenesis of filarial infection and have led to novel approaches to the diagnosis and treatment of travelers and immigrants from filarial-endemic regions.}, }
@article {pmid18375759, year = {2008}, author = {Ruiz, N and Gronenberg, LS and Kahne, D and Silhavy, TJ}, title = {Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {14}, pages = {5537-5542}, pmid = {18375759}, issn = {1091-6490}, support = {GM66174/GM/NIGMS NIH HHS/United States ; R01 GM034821/GM/NIGMS NIH HHS/United States ; R01 GM066174/GM/NIGMS NIH HHS/United States ; GM34821/GM/NIGMS NIH HHS/United States ; R01 AI081059/AI/NIAID NIH HHS/United States ; R37 GM034821/GM/NIGMS NIH HHS/United States ; }, mesh = {ATP-Binding Cassette Transporters/*physiology ; Biological Transport ; Cell Membrane/*metabolism ; Computational Biology ; Escherichia coli ; Escherichia coli Proteins/*physiology ; Lipopolysaccharides/*metabolism ; Membrane Proteins/*physiology ; }, abstract = {The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. LPS, or endotoxin, is a molecule of important biological activities. In the host, LPS elicits a potent immune response, while in the bacterium, it plays a crucial role by establishing a barrier to limit entry of hydrophobic molecules. Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. Much is known about the biosynthesis of LPS but, until recently, little was known about its transport and assembly. We applied a reductionist bioinformatic approach that takes advantage of the small size of the proteome of the Gram-negative endosymbiont Blochmannia floridanus to search for novel factors involved in OM biogenesis. This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM.}, }
@article {pmid18371947, year = {2008}, author = {Pucciarelli, S and Buonanno, F and Pellegrini, G and Pozzi, S and Ballarini, P and Miceli, C}, title = {Biomonitoring of Lake Garda: Identification of ciliate species and symbiotic algae responsible for the "black-spot" bloom during the summer of 2004.}, journal = {Environmental research}, volume = {107}, number = {2}, pages = {194-200}, doi = {10.1016/j.envres.2008.02.001}, pmid = {18371947}, issn = {1096-0953}, mesh = {Animals ; Chlorella/*isolation &amp; purification/physiology ; Ciliophora/*isolation &amp; purification/microbiology ; *Ecosystem ; Eutrophication/*physiology ; Fresh Water/*microbiology ; Italy ; Symbiosis/physiology ; }, abstract = {At the end of July 2004, a "black-spot" appeared in the western portion of Lake Garda, an oligomictic lake classified as meso-oligotrophic. A few days later, this phenomenon spread throughout the lake. A first analysis by optical microscopy revealed that the origin of the black spot was a ciliated protozoan. Ciliates represent a small percentage of the total zooplanktonic community of Lake Garda and have never produced bloom episodes. Using morphological and molecular analysis, we characterized the protozoan responsible for the bloom as Stentor amethystinus and its symbiotic algae as a Chlorella sp. Continuous monitoring of the northeast of Lake Garda showed that the apex of the S. amethystinus bloom took place during the first 20 days of August, and the highest density of S. amethystinus occurred in the euphotic zone. During this period, high chlorophyll a values were obtained in water samples collected from the euphotic zone due to the presence of the endosymbiont Chlorella. After early September, the black spot completely disappeared, and the causative organism was detected at low concentration only in the southern basin of the lake. The results obtained on the progress of the black spot phenomenon led us to hypothesize that: (i) S. amethystinus was recently introduced in Lake Garda by anthropogenic activities or it was already a member of the zooplanktonic community but at a very low concentration; (ii) S. amethystinus blooms may have been driven by an unusual high availability of total phosphorous in the euphotic zone and (iii) Lake Garda is not the preferred habitat for S. amethystinus.}, }
@article {pmid18356055, year = {2008}, author = {Nowack, EC and Melkonian, M and Glöckner, G}, title = {Chromatophore genome sequence of Paulinella sheds light on acquisition of photosynthesis by eukaryotes.}, journal = {Current biology : CB}, volume = {18}, number = {6}, pages = {410-418}, doi = {10.1016/j.cub.2008.02.051}, pmid = {18356055}, issn = {0960-9822}, mesh = {Animals ; Biological Transport/genetics ; Biosynthetic Pathways/genetics ; Cell Division/genetics ; Cell Membrane/genetics ; Cell Wall/genetics ; DNA Repair/genetics ; DNA Replication/genetics ; Eukaryota/*genetics ; Eukaryotic Cells/physiology ; Gene Deletion ; Genome, Plastid ; Photosynthesis/*genetics ; Plastids/*genetics ; Sequence Homology, Nucleic Acid ; Symbiosis/*genetics ; Synechococcus/genetics ; Time Factors ; }, abstract = {BACKGROUND: It is commonly accepted that a single primary endosymbiosis gave rise to the photosynthetic organelles of plants, the plastids. Recently, we presented evidence that photosynthetic inclusions, termed "chromatophores," present in the filose thecamoeba Paulinella chromatophora originated from an independent, more recent primary endosymbiotic event. To clarify metabolic capabilities of the chromatophore and its state of integration into the host, we present here the complete genome sequence of the chromatophore.<br><br>RESULTS: Our data reveal a fundamental reduction of the chromatophore genome. The single, circular chromosome of 1.02 Mb encodes 867 protein-coding genes and is, therewith, the smallest cyanobacterial genome reported to date. Compared to Synechococcus WH5701, a free-living relative of the chromatophore, only 26% of the genes were retained. Eleven putative pseudogenes were identified, indicating that reductive genome evolution is ongoing. Although the chromatophore genome contains a complete set of photosynthesis genes, it lacks not only genes thought to be dispensable for an intracellular lifestyle but also genes of essential pathways for amino acid and cofactor synthesis.<br><br>CONCLUSIONS: Our data characterize the chromatophore as a photosynthetic entity that is absolutely dependent on its host for growth and survival. Thus, the chromatophores of P. chromatophora are the only known cyanobacterial descendants besides plastids with a significantly reduced genome that confer photosynthesis to their eukaryotic host. Their comparison with plastids and bacterial endosymbionts of invertebrates sheds light on early steps of the integration of a photosynthetic prokaryote into a eukaryotic cell.}, }
@article {pmid18355299, year = {2008}, author = {van Overbeek, L and Gassner, F and van der Plas, CL and Kastelein, P and Nunes-da Rocha, U and Takken, W}, title = {Diversity of Ixodes ricinus tick-associated bacterial communities from different forests.}, journal = {FEMS microbiology ecology}, volume = {66}, number = {1}, pages = {72-84}, doi = {10.1111/j.1574-6941.2008.00468.x}, pmid = {18355299}, issn = {0168-6496}, mesh = {Animals ; Bacteria/*genetics ; *Biodiversity ; Borrelia/genetics/growth &amp; development ; DNA, Bacterial/genetics ; Genes, Bacterial ; Genes, rRNA ; Geography ; Ixodes/*microbiology ; Netherlands ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Species Specificity ; }, abstract = {Nymphal Ixodes ricinus ticks (n=180) were collected from three different areas in the Netherlands to investigate the effect of forest composition on tick-associated microbial communities. Sampled habitats differed in thickness of leaf litter and humus layers and vegetation associations and were located near Amsterdam (Beech-Oak), Ede (Birch-Oak) and Veldhoven (Birch-Oak). Analysis of nine 16S rRNA gene clone libraries made from individual ticks showed nearest matches with presumed pathogens Candidatus Neoehrlichia mikurensis and Rickettsia australis and arthropod endosymbionts Wolbachia pipientis and Candidatus Midichloria mitochondrii. Total bacterial species diversity (Shannon index) and Borrelia species infections were determined in I. ricinus by, respectively, PCR-denaturing gradient gel-electrophoresis and PCR-reverse line blot with probes specific for Borrelia burgdorferi sensu stricto, Borrelia afzelii, Borrelia garinii, Borrelia valaisiana, Borrelia lusitaniae and Borrelia ruski. Bacterial diversity differed significantly per area and was lowest in Ede. In contrast, Borrelia species-infected ticks were more abundant in Ede, Candidatus Neoehrlichia mikurensis-infected ticks in Ede and Veldhoven, and R. australis-infected ticks in Amsterdam. Borrelia afzelii was the most common Borrelia species found in all three areas. Bacterial tick diversity was influenced by local differences in forest structure, which is proposed to modulate animal populations that are commonly parasitized by I. ricinus.}, }
@article {pmid18353992, year = {2008}, author = {Tonkin, CJ and Foth, BJ and Ralph, SA and Struck, N and Cowman, AF and McFadden, GI}, title = {Evolution of malaria parasite plastid targeting sequences.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, number = {12}, pages = {4781-4785}, pmid = {18353992}, issn = {1091-6490}, support = {//Howard Hughes Medical Institute/United States ; }, mesh = {Amino Acid Sequence ; Animals ; *Evolution, Molecular ; Exons/genetics ; Genome, Protozoan ; Green Fluorescent Proteins/metabolism ; Humans ; Malaria/*parasitology ; Molecular Sequence Data ; Parasites/*chemistry ; Peptides/chemistry ; Plasmodium falciparum/*chemistry/cytology/genetics ; Plastids ; *Protein Sorting Signals ; }, abstract = {The transfer of genes from an endosymbiont to its host typically requires acquisition of targeting signals by the gene product to ensure its return to the endosymbiont for function. Many hundreds of plastid-derived genes must have acquired transit peptides for successful relocation to the nucleus. Here, we explore potential evolutionary origins of plastid transit peptides in the malaria parasite Plasmodium falciparum. We show that exons of the P. falciparum genome could serve as transit peptides after exon shuffling. We further demonstrate that numerous randomized peptides and even whimsical sequences based on English words can also function as transit peptides in vivo. Thus, facile acquisition of transit peptides from existing sequence likely expedited endosymbiont integration through intracellular gene transfer.}, }
@article {pmid18348962, year = {2008}, author = {Jones, AM and Berkelmans, R and van Oppen, MJ and Mieog, JC and Sinclair, W}, title = {A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.}, journal = {Proceedings. Biological sciences}, volume = {275}, number = {1641}, pages = {1359-1365}, pmid = {18348962}, issn = {0962-8452}, mesh = {Acclimatization/*physiology ; Animals ; Anthozoa/genetics/*physiology ; DNA/chemistry/genetics ; DNA, Intergenic/chemistry/genetics ; *Ecosystem ; Eukaryota/*physiology ; Genetic Variation ; Greenhouse Effect ; Polymorphism, Single-Stranded Conformational ; Regression Analysis ; Symbiosis ; Temperature ; }, abstract = {The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. Although the potential exists for this to translate into substantial thermal acclimatization of coral communities, to date there is no evidence to show that this takes place under natural conditions. In this study, we show field evidence of a dramatic change in the symbiont community of Acropora millepora, a common and widespread Indo-Pacific hard coral species, after a natural bleaching event in early 2006 in the Keppel Islands (Great Barrier Reef). Before bleaching, 93.5% (n=460) of the randomly sampled and tagged colonies predominantly harboured the thermally sensitive Symbiodinium type C2, while the remainder harboured a tolerant Symbiodinium type belonging to clade D or mixtures of C2 and D. After bleaching, 71% of the surviving tagged colonies that were initially C2 predominant changed to D or C1 predominance. Colonies that were originally C2 predominant suffered high mortality (37%) compared with D-predominant colonies (8%). We estimate that just over 18% of the original A. millepora population survived unchanged leaving 29% of the population C2 and 71% D or C1 predominant six months after the bleaching event. This change in the symbiont community structure, while it persists, is likely to have substantially increased the thermal tolerance of this coral population. Understanding the processes that underpin the temporal changes in symbiont communities is key to assessing the acclimatization potential of reef corals.}, }
@article {pmid18315522, year = {2008}, author = {Gould, SB and Waller, RF and McFadden, GI}, title = {Plastid evolution.}, journal = {Annual review of plant biology}, volume = {59}, number = {}, pages = {491-517}, doi = {10.1146/annurev.arplant.59.032607.092915}, pmid = {18315522}, issn = {1543-5008}, support = {//Howard Hughes Medical Institute/United States ; }, mesh = {Chlorophyll/physiology ; Eukaryotic Cells/physiology ; *Evolution, Molecular ; Models, Biological ; Plant Physiological Phenomena ; Plants/genetics ; Plastids/*genetics ; Symbiosis ; }, abstract = {The ancestors of modern cyanobacteria invented O(2)-generating photosynthesis some 3.6 billion years ago. The conversion of water and CO(2) into energy-rich sugars and O(2) slowly transformed the planet, eventually creating the biosphere as we know it today. Eukaryotes didn't invent photosynthesis; they co-opted it from prokaryotes by engulfing and stably integrating a photoautotrophic prokaryote in a process known as primary endosymbiosis. After approximately a billion of years of coevolution, the eukaryotic host and its endosymbiont have achieved an extraordinary level of integration and have spawned a bewildering array of primary producers that now underpin life on land and in the water. No partnership has been more important to life on earth. Secondary endosymbioses have created additional autotrophic eukaryotic lineages that include key organisms in the marine environment. Some of these organisms have subsequently reverted to heterotrophic lifestyles, becoming significant pathogens, microscopic predators, and consumers. We review the origins, integration, and functions of the different plastid types with special emphasis on their biochemical abilities, transfer of genes to the host, and the back supply of proteins to the endosymbiont.}, }
@article {pmid18312338, year = {2008}, author = {Härri, SA and Krauss, J and Müller, CB}, title = {Natural enemies act faster than endophytic fungi in population control of cereal aphids.}, journal = {The Journal of animal ecology}, volume = {77}, number = {3}, pages = {605-611}, doi = {10.1111/j.1365-2656.2008.01373.x}, pmid = {18312338}, issn = {1365-2656}, mesh = {Animals ; Aphids/microbiology/*physiology ; *Ecosystem ; Hypocreales/*physiology ; Linear Models ; Lolium/*microbiology ; Nymph/physiology ; *Pest Control, Biological/methods ; Population Density ; Predatory Behavior/physiology ; Random Allocation ; }, abstract = {1. Fast-growing populations of phytophagous insects can be limited by the presence of natural enemies and by alkaloids that are produced by symbiotic associations of many temperate grass species with endophytic fungi. It is unclear if and how acquired plant defences derived from endophytic fungi interact with natural enemies to affect phytophagous insect populations. 2. To assess the relative importance of endophytic fungi compared to that of natural enemies on the population dynamics of phytophagous insects, we carried out a fully factorial field experiment, in which the presence of natural enemies and the presence of endophytic fungi were manipulated simultaneously. Target colonies of aphids were monitored for 8 weeks starting from their natural appearance in the field to the end of the aphid season. 3. We show that on Lolium perenne increased natural enemy densities reduced the individual numbers of two common cereal aphids, Rhopalosiphum padi and Metopolophium festucae. 4. The presence of the endophytic fungi Neotyphodium lolii reduced the number of M. festucae but did not affect the number of R. padi. The reduction in R. padi numbers by predators and parasitoids was not influenced by the presence of endophytes. For adult M. festucae, however, the negative effects of natural enemies were significant only in the absence of endophytes. 5. Over the duration of the experiment, the effect of natural enemies on aphid colony growth was much stronger than the effect of the endophytic fungi N. lolii, presumably because predator and parasitoid action on aphid colonies is much faster than any effects of endophytes. 6. Our results demonstrate that with simultaneous action of acquired endosymbionts and natural enemies, both factors can control aphid colony growth but they generally act independently of each other.}, }
@article {pmid18310662, year = {2008}, author = {Conord, C and Despres, L and Vallier, A and Balmand, S and Miquel, C and Zundel, S and Lemperiere, G and Heddi, A}, title = {Long-term evolutionary stability of bacterial endosymbiosis in curculionoidea: additional evidence of symbiont replacement in the dryophthoridae family.}, journal = {Molecular biology and evolution}, volume = {25}, number = {5}, pages = {859-868}, doi = {10.1093/molbev/msn027}, pmid = {18310662}, issn = {1537-1719}, mesh = {Animals ; *Biological Evolution ; DNA, Bacterial ; DNA, Ribosomal ; *Gammaproteobacteria/classification ; Genetic Speciation ; In Situ Hybridization, Fluorescence ; Phylogeny ; Symbiosis ; Weevils/classification/*microbiology ; }, abstract = {Bacterial intracellular symbiosis (endosymbiosis) is well documented in the insect world where it is believed to play a crucial role in adaptation and evolution. However, although Coleopteran insects are of huge ecological and economical interest, endosymbiont molecular analysis is limited to the Dryophthoridae family. Here, we have analyzed the intracellular symbiotic bacteria in 2 Hylobius species belonging to the Molytinae subfamily (Curculionoidea superfamily) that exhibit different features from the Dryophthoridae insects in terms of their ecology and geographical spanning. Fluorescence in situ hybridization has shown that both Hylobius species harbor rod-shaped pleiomorphic symbiotic bacteria in the oocyte and in the bacteria-bearing organ (the bacteriome), with a shape and location similar to those of the Dryophthoridae bacteriome. Phylogenetic analysis of the 16S ribosomal DNA gene sequences, using the heterogeneous model of DNA evolution, has placed the Hylobius spp. endosymbionts (H-group) at the basal position of the ancestral R-clade of Dryophthoridae endosymbionts named Candidatus Nardonella but relatively distant from the S-clade of Sitophilus spp. endosymbionts. Endosymbionts from the H-group and the R-clade evolved more quickly compared with free-living enteric bacteria and endosymbionts from the S- and D-clades of Dryophthoridae. They are AT biased (58.3% A + T), and they exhibit AT-rich insertions at the same position as previously described in the Candidatus Nardonella 16S rDNA sequence. Moreover, the host phylogenetic tree based on the mitochondrial COI gene was shown to be highly congruent with the H-group and the R-clade, the divergence of which was estimated to be around 125 MYA. These new molecular data show that endosymbiosis is old in Curculionids, going back at least to the common ancestor of Molytinae and Dryophthoridae, and is evolutionary stable, except in 2 Dryophthoridae clades, providing additional and independent supplementary evidence for endosymbiont replacement in these taxa.}, }
@article {pmid18294414, year = {2008}, author = {Xu, Q and Meng, L and Li, B and Mills, N}, title = {Influence of host size variation on the development of a koinobiont aphid parasitoid, Lysiphlebus ambiguus Haliday (Braconidae, Hymenoptera).}, journal = {Bulletin of entomological research}, volume = {98}, number = {4}, pages = {389-395}, doi = {10.1017/S0007485308005683}, pmid = {18294414}, issn = {0007-4853}, mesh = {Animals ; Aphids/*growth &amp; development/parasitology/*pathogenicity ; Body Size ; Female ; Host-Parasite Interactions ; Hymenoptera/*growth &amp; development/parasitology/*pathogenicity ; Larva ; }, abstract = {To determine whether host body size is the currency used by the aphidiine parasitoid, Lysiphlebus ambiguus Haliday (Hymenoptera: Braconidae), in assessing host quality, the aphid, Aphis fabae Scopoli (Homoptera: Aphididae), was reared at either high or low temperature to yield hosts of the same instar with different body sizes. Cohorts of A. fabae raised at 15 degrees C and 30 degrees C and exposed to individual female L. ambiguus in no-choice tests were successfully parasitized in all host stages from 1st instar nymphs to adults. However, younger and smaller aphids were more susceptible to parasitism than older and larger nymphs or adults, as measured by the number of mummies produced. For aphid cohorts reared at 15 degrees C, the proportion of female progeny, progeny adult size, and development time all increased linearly with aphid size at the time of attack. In contrast, for aphid cohorts raised at 30 degrees C, the proportion of female progeny and progeny adult size declined with aphid size, while development time remained unaffected. Through manipulation of host rearing temperature, we have shown that at cooler temperatures the koinobiont parasitoid, L. ambiguus, responds to host size in the same way as an idiobiont parasitoid, but that this response is compromised at higher temperatures. Our results suggest that differential mortality during development is likely to influence the observed secondary sex ratio in relation to aphid size for aphid cohorts raised at higher temperatures due to disruption of the activity of the host's primary endosymbiont and that such reduced nutritional quality of aphids cannot be compensated by increased development time.}, }
@article {pmid18291041, year = {2008}, author = {Viljakainen, L and Reuter, M and Pamilo, P}, title = {Wolbachia transmission dynamics in Formica wood ants.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {55}, pmid = {18291041}, issn = {1471-2148}, mesh = {Animals ; Ants/classification/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genetic Variation ; Haplotypes ; *Host-Pathogen Interactions ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Wolbachia/classification/*physiology ; }, abstract = {BACKGROUND: The role of Wolbachia endosymbionts in shaping the mitochondrial diversity of their arthropod host depends on the effects they have on host reproduction and on the mode of transmission of the bacteria. We have compared the sequence diversity of wsp (Wolbachia surface protein gene) and the host mtDNA in a group of Formica ant species that have diverged approximately 0.5 million years ago (MYA). The aim was to study the relationship of Wolbachia and its ant hosts in terms of vertical and horizontal transmission of the bacteria.<br><br>RESULTS: All studied ant species were doubly infected with two Wolbachia strains (wFex1 and wFex4) all over their geographical distribution area in Eurasia. The most common haplotypes of these strains were identical with strains previously described from a more distantly related Formica ant, with an estimated divergence time of 3.5 - 4 MYA. Some strain haplotypes were associated to the same or closely related mtDNA haplotypes as expected under vertical transmission. However, in several cases the wsp haplotypes coexisted with distant mtDNA haplotypes, a pattern which is more compatible with horizontal transmission of the bacteria.<br><br>CONCLUSION: Two lines of evidence suggest that the sharing of Wolbachia strains by all F. rufa species is rather due to horizontal than vertical transmission. First, the fact that endosymbiont strains identical to those of F. rufa ants have been found in another species that diverged 3.5-4 MYA strongly suggests that horizontal transfer can and does occur between Formica ants. Second, the frequent sharing of identical Wolbachia strains by distant mitochondrial lineages within the F. rufa group further shows that horizontal transmission has occurred repeatedly. Nevertheless, our dataset also provides some evidence for longer-term persistence of infection, indicating that Wolbachia infection within this host clade has been shaped by both horizontal and vertical transmission of symbionts. The fact that all the ants were infected irrespective of the family structure of their societies gives no support to the proposed hypotheses that the spreading of Wolbachia in ants might be associated to the types of their societies.}, }
@article {pmid18282572, year = {2008}, author = {Arumugam, S and Pfarr, KM and Hoerauf, A}, title = {Infection of the intermediate mite host with Wolbachia-depleted Litomosoides sigmodontis microfilariae: impaired L1 to L3 development and subsequent sex-ratio distortion in adult worms.}, journal = {International journal for parasitology}, volume = {38}, number = {8-9}, pages = {981-987}, doi = {10.1016/j.ijpara.2007.12.006}, pmid = {18282572}, issn = {0020-7519}, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage/*pharmacology ; DNA, Bacterial/analysis ; DNA, Helminth/analysis/drug effects ; Gerbillinae/*parasitology ; Humans ; Male ; Microfilariae/*growth &amp; development/microbiology ; Mites/parasitology ; Polymerase Chain Reaction ; *Sex Ratio ; Tetracycline/administration &amp; dosage/*pharmacology ; Wolbachia/*drug effects/isolation &amp; purification ; }, abstract = {The rodent filaria Litomosoides sigmodontis harbour Wolbachia, endosymbionts essential for worm embryogenesis, larval development and adult survival. To study the effect of tetracycline, which depletes Wolbachia, on the development of microfilariae (L1s, MF) to L3 in the intermediate host Ornithonyssus bacoti, and to observe the development of Wolbachia-depleted L3s in Mongolian gerbils (Meriones unguiculatus); microfilaremic gerbils were treated orally with tetracycline for 6 weeks (primary infected Tet) or untreated (primary Con). Treatment resulted in a significant reduction of Wolbachia per MF in primary Tet gerbils. Naïve mites then fed on the primary Tet and primary Con gerbils in the week after treatment ended, when MF levels were not significantly different, and used to infect new gerbils (secondary infected) Tet, secondary Con) via natural infection. The infection rate from dissected mites was 9% and 54% (primary Tet and primary Con, respectively). After 3 months, worms were isolated from secondary gerbils. Significantly fewer female worms developed in secondary Tet gerbils. In contrast, there was no difference in the number of male worms that developed in secondary gerbils, resulting in a male biased sex-ratio. Although secondary Tet male worms had fewer Wolbachia than secondary Con males, development was not impaired. Female worms that developed from Wolbachia-depleted MF had Wolbachia levels equivalent to worms from secondary Con animals. Thus, tetracycline pre-treatment selected for female worms with high numbers of Wolbachia, whereas male worms had median Wolbachia levels significantly lower than secondary Con males. Therefore, female worms require a higher threshold of Wolbachia for their development. The worms analysed were only exposed to tetracycline as MF, ruling out direct effects of tetracycline during larval development in the mites or secondary gerbils, suggesting that the depletion of Wolbachia in MF was the cause of impaired larval development.}, }
@article {pmid18272191, year = {2008}, author = {Sacchi, L and Genchi, M and Clementi, E and Bigliardi, E and Avanzati, AM and Pajoro, M and Negri, I and Marzorati, M and Gonella, E and Alma, A and Daffonchio, D and Bandi, C}, title = {Multiple symbiosis in the leafhopper Scaphoideus titanus (Hemiptera: Cicadellidae): details of transovarial transmission of Cardinium sp. and yeast-like endosymbionts.}, journal = {Tissue &amp; cell}, volume = {40}, number = {4}, pages = {231-242}, doi = {10.1016/j.tice.2007.12.005}, pmid = {18272191}, issn = {0040-8166}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Bacteroidetes/ultrastructure ; Digestive System/microbiology/ultrastructure ; Embryo, Nonmammalian/ultrastructure ; Fat Body/microbiology/ultrastructure ; Female ; Hemiptera/*microbiology/ultrastructure ; In Situ Hybridization ; Ovary/*microbiology/ultrastructure ; Polymerase Chain Reaction ; *Symbiosis ; Yeasts/*physiology/ultrastructure ; }, abstract = {Scaphoideus titanus is the insect vector of flavescence dorée (FD), a yellow disease of grapevines. Observations on adult females and nymphs of S. titanus showed that this insect is associated with a complex microbial community. Ultrastructural analysis showed that the fat body, salivary glands and ovary of the insect harbour microorganisms showing the brush-like structure typically observed in the genus Cardinium. In particular, it has been shown that these symbiotic bacteria are present both in the follicular cells and in the eggs. In addition, cells resembling bacteriocytes, harbouring numerous Cardinium symbionts in the cytoplasm, were observed in the apical portion of the ovary in adult females. These cells are likely responsible for bacterial transmission to the ovary. Optical microscopy showed that the fat body harbours an enormous population of yeast-like symbionts (YLSs). Ultrastructural observations showed that these symbionts are enclosed within specialized cells of the fat body and are also present in the ovary, where they are found in both the follicular cells and the eggs. There is thus evidence that both Cardinium and the YLSs are transovarially transmitted to the offspring. To our knowledge, S. titanus is the sole insect known to transmit two different kinds of symbionts to the eggs, a prokaryote and an eukaryote. Gene sequence analysis and in situ hybridization led to the identification of YLSs as members of the class Sordariomycetes (=Pyrenomycetes). Finally, ultrastructural observation of the midgut content revealed the presence, in both adult females and nymphs, of a complex microbial community, which include a phytoplasma-like microorganism, likely the agent of FD.}, }
@article {pmid18268509, year = {2008}, author = {Moya, A and Peretó, J and Gil, R and Latorre, A}, title = {Learning how to live together: genomic insights into prokaryote-animal symbioses.}, journal = {Nature reviews. Genetics}, volume = {9}, number = {3}, pages = {218-229}, doi = {10.1038/nrg2319}, pmid = {18268509}, issn = {1471-0064}, mesh = {Animals ; Bacteria/*genetics ; Bacterial Physiological Phenomena ; *Genomics ; *Symbiosis ; }, abstract = {Our understanding of prokaryote-eukaryote symbioses as a source of evolutionary innovation has been rapidly increased by the advent of genomics, which has made possible the biological study of uncultivable endosymbionts. Genomics is allowing the dissection of the evolutionary process that starts with host invasion then progresses from facultative to obligate symbiosis and ends with replacement by, or coexistence with, new symbionts. Moreover, genomics has provided important clues on the mechanisms driving the genome-reduction process, the functions that are retained by the endosymbionts, the role of the host, and the factors that might determine whether the association will become parasitic or mutualistic.}, }
@article {pmid18266738, year = {2008}, author = {Chang, WS and Park, KM and Koh, SC and So, JS}, title = {Characterization of the Bradyrhizobium japonicum galE gene: its impact on lipopolysaccharide profile and nodulation of soybean.}, journal = {FEMS microbiology letters}, volume = {280}, number = {2}, pages = {242-249}, doi = {10.1111/j.1574-6968.2008.01066.x}, pmid = {18266738}, issn = {0378-1097}, mesh = {Bradyrhizobium/genetics/*physiology ; Lipopolysaccharides/*biosynthesis ; Nitrogen Fixation/drug effects ; Plant Roots/*growth &amp; development/microbiology ; Soybeans/*microbiology ; }, abstract = {The galE gene from Bradyrhizobium japonicum 61A101C, a soybean endosymbiont, was cloned and characterized. Its deduced amino-acid sequence showed a high similarity with that of other rhizobia. Functional identification of the galE gene was achieved by complementation of a galE mutant strain, PL2, with a series of pKM subclones. Disruption of the B. japonicum galE gene affects the lipopolysaccharide profile compared with that of the wild type, suggesting that galE is responsible for alteration of lipopolysaccharide structure. Examination of nodule formation by the wild-type and galE mutant revealed that the former displayed normal nodule development on soybean roots, whereas the latter showed no nodule formation at all time points examined except for 20 days after inoculation when <10% of soybean formed pseudo-nodules.}, }
@article {pmid18259058, year = {2008}, author = {Kurz, M and Iturbe-Ormaetxe, I and Jarrott, R and O'Neill, SL and Byriel, KA and Martin, JL and Heras, B}, title = {Crystallization and preliminary diffraction analysis of a DsbA homologue from Wolbachia pipientis.}, journal = {Acta crystallographica. Section F, Structural biology and crystallization communications}, volume = {64}, number = {Pt 2}, pages = {94-97}, pmid = {18259058}, issn = {1744-3091}, mesh = {Crystallization ; Crystallography, X-Ray ; Polymerase Chain Reaction ; Protein Disulfide-Isomerases/*chemistry ; Recombinant Proteins/chemistry ; Wolbachia/*chemistry ; }, abstract = {alpha-DsbA1 is one of two DsbA homologues encoded by the Gram-negative alpha-proteobacterium Wolbachia pipientis, an endosymbiont that can behave as a reproductive parasite in insects and as a mutualist in medically important filarial nematodes. The alpha-DsbA1 protein is thought to be important for the folding and secretion of Wolbachia proteins involved in the induction of reproductive distortions. Crystals of native and SeMet alpha-DsbA1 were grown by vapour diffusion and belong to the monoclinic space group C2, with unit-cell parameters a = 71.4, b = 49.5, c = 69.3 A, beta = 107.0 degrees and one molecule in the asymmetric unit (44% solvent content). X-ray data were recorded from native crystals to a resolution of 2.01 A using a copper anode and data from SeMet alpha-DsbA1 crystals were recorded to 2.45 A resolution using a chromium anode.}, }
@article {pmid18258101, year = {2008}, author = {Casson, N and Michel, R and Müller, KD and Aubert, JD and Greub, G}, title = {Protochlamydia naegleriophila as etiologic agent of pneumonia.}, journal = {Emerging infectious diseases}, volume = {14}, number = {1}, pages = {168-172}, pmid = {18258101}, issn = {1080-6040}, mesh = {Acanthamoeba castellanii/microbiology ; Animals ; Bronchoalveolar Lavage Fluid/*microbiology ; *Chlamydia Infections ; Chlamydiales/*classification/genetics/*pathogenicity ; DNA, Bacterial/classification/isolation &amp; purification ; Humans ; Naegleria/microbiology ; Pneumonia, Bacterial/*microbiology/pathology ; Polymerase Chain Reaction ; }, abstract = {Using ameba coculture, we grew a Naegleria endosymbiont. Phenotypic, genetic, and phylogenetic analyses supported its affiliation as Protochlamydia naegleriophila sp. nov. We then developed a specific diagnostic PCR for Protochlamydia spp. When applied to bronchoalveolar lavages, results of this PCR were positive for 1 patient with pneumonia. Further studies are needed to assess the role of Protochlamydia spp. in pneumonia.}, }
@article {pmid18257289, year = {2007}, author = {Nefedova, LN and Kim, AI}, title = {[Evolution from retrotransposons to retroviruses: origin of the env gene].}, journal = {Zhurnal obshchei biologii}, volume = {68}, number = {6}, pages = {459-467}, pmid = {18257289}, issn = {0044-4596}, mesh = {Animals ; Drosophila melanogaster ; *Evolution, Molecular ; Gene Products, env/*genetics ; Genome, Insect/physiology ; Retroelements/*physiology ; Retroviridae/*physiology ; }, abstract = {In genome of Drosophila melanogaster, various families of retrotransposons with different combination of functional domens and mechanisms of transposition are present. However only retrotransposons of gypsy family are retroviruses related to errantiviruses. Other families seemingly appeared as intermediate forms of retroviruses evolution. Despite the fact that the question on origin of retroviruses remains unclear, now the hypothesis of their origin from retrotransoposons can be considered the most consistent. Infectious properties of errantiviruses are linked to the presence of the third open reading frame (the env gene). Acquisition of the env gene conversed retrotransposons into retroviruses. So, origin of this gene is of special interest. Homologues of the env gene of errantiviruses are discovered in genomes of D. melanogaster, as well as in baculoviruses and in bacteria Wolbachia pipientis, the endosymbiont of Drosophila. It was shown that homologue of the env gene come to Wolbachia genome from Drosophila genome by horizontal transfer of the gypsy group retrotransposon. Thus, Wolbachia was not a donor of the env gene for errantiviruses. Seemingly, errantiviruses captured the baculoviral homologue of the env gene (f). However origin of the f gene is not clear. At the same time the env gene homologue in D. melanogaster genome exist (Iris). It must not be ruled out that the Iris gene was the source of the env gene of errantiviruses and baculoviruses.}, }
@article {pmid18248682, year = {2008}, author = {Patron, NJ and Durnford, DG and Kopriva, S}, title = {Sulfate assimilation in eukaryotes: fusions, relocations and lateral transfers.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {39}, pmid = {18248682}, issn = {1471-2148}, support = {//Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Adenosine Triphosphate/metabolism ; Cyanobacteria/genetics ; Eukaryotic Cells/*metabolism ; Gene Transfer, Horizontal/genetics ; Microscopy, Electron, Transmission ; Oxidoreductases/classification/genetics/metabolism ; Oxidoreductases Acting on Sulfur Group Donors/classification/genetics/metabolism ; Phylogeny ; Plastids/metabolism ; Protein Isoforms/genetics/metabolism ; Sulfate Adenylyltransferase/classification/genetics/metabolism ; Sulfates/*metabolism ; }, abstract = {BACKGROUND: The sulfate assimilation pathway is present in photosynthetic organisms, fungi, and many bacteria, providing reduced sulfur for the synthesis of cysteine and methionine and a range of other metabolites. In photosynthetic eukaryotes sulfate is reduced in the plastids whereas in aplastidic eukaryotes the pathway is cytosolic. The only known exception is Euglena gracilis, where the pathway is localized in mitochondria. To obtain an insight into the evolution of the sulfate assimilation pathway in eukaryotes and relationships of the differently compartmentalized isoforms we determined the locations of the pathway in lineages for which this was unknown and performed detailed phylogenetic analyses of three enzymes involved in sulfate reduction: ATP sulfurylase (ATPS), adenosine 5'-phosphosulfate reductase (APR) and sulfite reductase (SiR).<br><br>RESULTS: The inheritance of ATPS, APR and the related 3'-phosphoadenosine 5'-phosphosulfate reductase (PAPR) are remarkable, with multiple origins in the lineages that comprise the opisthokonts, different isoforms in chlorophytes and streptophytes, gene fusions with other enzymes of the pathway, evidence a eukaryote to prokaryote lateral gene transfer, changes in substrate specificity and two reversals of cellular location of host- and endosymbiont-originating enzymes. We also found that the ATPS and APR active in the mitochondria of Euglena were inherited from its secondary, green algal plastid.<br><br>CONCLUSION: Our results reveal a complex history for the enzymes of the sulfate assimilation pathway. Whilst they shed light on the origin of some characterised novelties, such as a recently described novel isoform of APR from Bryophytes and the origin of the pathway active in the mitochondria of Euglenids, the many distinct and novel isoforms identified here represent an excellent resource for detailed biochemical studies of the enzyme structure/function relationships.}, }
@article {pmid18248510, year = {2008}, author = {Fathinejad, S and Steiner, JM and Reipert, S and Marchetti, M and Allmaier, G and Burey, SC and Ohnishi, N and Fukuzawa, H and Löffelhardt, W and Bohnert, HJ}, title = {A carboxysomal carbon-concentrating mechanism in the cyanelles of the 'coelacanth' of the algal world, Cyanophora paradoxa?.}, journal = {Physiologia plantarum}, volume = {133}, number = {1}, pages = {27-32}, doi = {10.1111/j.1399-3054.2007.01030.x}, pmid = {18248510}, issn = {1399-3054}, mesh = {Algal Proteins/metabolism/physiology ; Carbon/*metabolism ; Carbon Dioxide/*metabolism ; Cyanophora/cytology/*metabolism ; }, abstract = {Cyanelles are the peculiar plastids of glaucocystophyte algae that retained a peptidoglycan wall from the ancestral cyanobacterial endosymbiont. All cyanobacteria and most algae possess an inorganic carbon-concentrating mechanism (CCM) that involves a microcompartment--carboxysomes in prokaryotes and pyrenoids in eukaryotes--harboring the bulk of cellular (plastidic) Rubisco. In the case of the living fossil, Cyanophora paradoxa, the existence of a CCM was a matter of debate. Microarray data revealing 142 CO(2)-responsive genes (induced or repressed through a shift from high to low CO(2) conditions), gas exchange measurements and measurements of photosynthetic affinity provided strong support for a CCM. We favor a recent hypothesis that glaucocystophyte cyanelles as the closest cousins to cyanobacteria among plastids contain 'eukaryotic carboxysomes': bicarbonate enrichment within cyanelles should be considerably higher than in chloroplasts with their pyrenoid-based CCM. Thus, the stress-bearing function of the peptidoglycan layer, the other unique heritage, would be indispensable. An isolation method for cyanelle 'carboxysomes' was developed and the protein components other than Rubisco analyzed by MS. Rubisco activase was identified and corroborated by western blotting. The well-established cyanelle in vitro import system allows to use them as 'honorary cyanobacteria': assembly processes of supramolecular structures as phycobilisomes and carboxysomes thus can be studied after import of nucleus-encoded precursor proteins and subsequent fractionation. Even minor components can easily be tracked and a surprisingly dynamic view is obtained. Labeled pre-activase was imported into isolated cyanelles and 30% of the mature protein was found to be incorporated into the carboxysome fraction. A final decision between carboxysome or pyrenoid must await the identification of cyanelle carbonic anhydrase and, especially, the demonstration of shell proteins.}, }
@article {pmid18237306, year = {2008}, author = {Robidart, JC and Bench, SR and Feldman, RA and Novoradovsky, A and Podell, SB and Gaasterland, T and Allen, EE and Felbeck, H}, title = {Metabolic versatility of the Riftia pachyptila endosymbiont revealed through metagenomics.}, journal = {Environmental microbiology}, volume = {10}, number = {3}, pages = {727-737}, doi = {10.1111/j.1462-2920.2007.01496.x}, pmid = {18237306}, issn = {1462-2920}, support = {2P30CA23100-18/CA/NCI NIH HHS/United States ; }, mesh = {Animals ; Bacterial Physiological Phenomena ; Helicobacter heilmannii/genetics/*physiology ; Molecular Sequence Data ; Polychaeta/metabolism/*microbiology/*physiology ; *Symbiosis ; }, abstract = {The facultative symbiont of Riftia pachyptila, named here Candidatus Endoriftia persephone, has evaded culture to date, but much has been learned regarding this symbiosis over the past three decades since its discovery. The symbiont population metagenome was sequenced in order to gain insight into its physiology. The population genome indicates that the symbionts use a partial Calvin-Benson Cycle for carbon fixation and the reverse TCA cycle (an alternative pathway for carbon fixation) that contains an unusual ATP citrate lyase. The presence of all genes necessary for heterotrophic metabolism, a phosphotransferase system, and dicarboxylate and ABC transporters indicate that the symbiont can live mixotrophically. The metagenome has a large suite of signal transduction, defence (both biological and environmental) and chemotaxis mechanisms. The physiology of Candidatus Endoriftia persephone is explored with respect to functionality while associated with a eukaryotic host, versus free-living in the hydrothermal environment.}, }
@article {pmid18226230, year = {2008}, author = {Kneip, C and Voss, C and Lockhart, PJ and Maier, UG}, title = {The cyanobacterial endosymbiont of the unicellular algae Rhopalodia gibba shows reductive genome evolution.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {30}, pmid = {18226230}, issn = {1471-2148}, mesh = {Algal Proteins/genetics ; Bacterial Proteins/genetics ; Cloning, Molecular ; Cyanothece/*genetics ; DNA-Binding Proteins/genetics ; Diatoms/*genetics ; Gene Deletion ; *Genome, Bacterial ; Nitrogen Fixation/*genetics ; Operon ; Phylogeny ; Pseudogenes ; Rec A Recombinases/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: Bacteria occur in facultative association and intracellular symbiosis with a diversity of eukaryotic hosts. Recently, we have helped to characterise an intracellular nitrogen fixing bacterium, the so-called spheroid body, located within the diatom Rhopalodia gibba. Spheroid bodies are of cyanobacterial origin and exhibit features that suggest physiological adaptation to their intracellular life style. To investigate the genome modifications that have accompanied the process of endosymbiosis, here we compare gene structure, content and organisation in spheroid body and cyanobacterial genomes.<br><br>RESULTS: Comparison of the spheroid body's genome sequence with corresponding regions of near free-living relatives indicates that multiple modifications have occurred in the endosymbiont's genome. These include localised changes that have led to elimination of some genes. This gene loss has been accompanied either by deletion of the respective DNA region or replacement with non-coding DNA that is AT rich in composition. In addition, genome modifications have led to the fusion and truncation of genes. We also report that in the spheroid body's genome there is an accumulation of deleterious mutations in genes for cell wall biosynthesis and processes controlled by transposases. Interestingly, the formation of pseudogenes in the spheroid body has occurred in the presence of intact, and presumably functional, recA and recF genes. This is in contrast to the situation in most investigated obligate intracellular bacterium-eukaryote symbioses, where at least either recA or recF has been eliminated.<br><br>CONCLUSION: Our analyses suggest highly specific targeting/loss of individual genes during the process of genome reduction and establishment of a cyanobacterial endosymbiont inside a eukaryotic cell. Our findings confirm, at the genome level, earlier speculation on the obligate intracellular status of the spheroid body in Rhopalodia gibba. This association is the first example of an obligate cyanobacterial symbiosis involving nitrogen fixation for which genomic data are available. It represents a new model system to study molecular adaptations of genome evolution that accompany a switch from free-living to intracellular existence.}, }
@article {pmid18226217, year = {2008}, author = {Mastronunzio, JE and Tisa, LS and Normand, P and Benson, DR}, title = {Comparative secretome analysis suggests low plant cell wall degrading capacity in Frankia symbionts.}, journal = {BMC genomics}, volume = {9}, number = {}, pages = {47}, pmid = {18226217}, issn = {1471-2164}, mesh = {Cell Wall/microbiology ; Chromosome Mapping ; Frankia/*genetics/*physiology ; Genome, Bacterial ; Hydrolases/genetics/physiology ; Phylogeny ; Plants/*microbiology ; Proteome ; Species Specificity ; Symbiosis/genetics/physiology ; }, abstract = {BACKGROUND: Frankia sp. strains, the nitrogen-fixing facultative endosymbionts of actinorhizal plants, have long been proposed to secrete hydrolytic enzymes such as cellulases, pectinases, and proteases that may contribute to plant root penetration and formation of symbiotic root nodules. These or other secreted proteins might logically be involved in the as yet unknown molecular interactions between Frankia and their host plants. We compared the genome-based secretomes of three Frankia strains representing diverse host specificities. Signal peptide detection algorithms were used to predict the individual secretomes of each strain, and the set of secreted proteins shared among the strains, termed the core Frankia secretome. Proteins in the core secretome may be involved in the actinorhizal symbiosis.<br><br>RESULTS: The Frankia genomes have conserved Sec (general secretory) and Tat (twin arginine translocase) secretion systems. The potential secretome of each Frankia strain comprised 4-5% of the total proteome, a lower percentage than that found in the genomes of other actinobacteria, legume endosymbionts, and plant pathogens. Hydrolytic enzymes made up only a small fraction of the total number of predicted secreted proteins in each strain. Surprisingly, polysaccharide-degrading enzymes were few in number, especially in strain CcI3, with more esterolytic, lipolytic and proteolytic enzymes having signal peptides. A total of 161 orthologous proteins belong to the core Frankia secretome. Of these, 52 also lack homologs in closely related actinobacteria, and are termed "Frankia-specific." The genes encoding these conserved secreted proteins are often clustered near secretion machinery genes.<br><br>CONCLUSION: The predicted secretomes of Frankia sp. are relatively small and include few hydrolases, which could reflect adaptation to a symbiotic lifestyle. There are no well-conserved secreted polysaccharide-degrading enzymes present in all three Frankia genomes, suggesting that plant cell wall polysaccharide degradation may not be crucial to root infection, or that this degradation varies among strains. We hypothesize that the relative lack of secreted polysaccharide-degrading enzymes in Frankia reflects a strategy used by these bacteria to avoid eliciting host defense responses. The esterases, lipases, and proteases found in the core Frankia secretome might facilitate hyphal penetration through the cell wall, release carbon sources, or modify chemical signals. The core secretome also includes extracellular solute-binding proteins and Frankia-specific hypothetical proteins that may enable the actinorhizal symbiosis.}, }
@article {pmid18222943, year = {2008}, author = {Deusch, O and Landan, G and Roettger, M and Gruenheit, N and Kowallik, KV and Allen, JF and Martin, W and Dagan, T}, title = {Genes of cyanobacterial origin in plant nuclear genomes point to a heterocyst-forming plastid ancestor.}, journal = {Molecular biology and evolution}, volume = {25}, number = {4}, pages = {748-761}, doi = {10.1093/molbev/msn022}, pmid = {18222943}, issn = {1537-1719}, mesh = {Amino Acid Sequence ; Animals ; Arabidopsis/genetics ; Bacterial Proteins/chemistry/genetics ; Cell Nucleus/*genetics ; Chlamydomonas/genetics ; Conserved Sequence ; Cyanobacteria/*genetics ; Gene Transfer, Horizontal ; *Genes, Bacterial ; Genome, Plant/*genetics ; Molecular Sequence Data ; Nitrogen Fixation/genetics ; Oryza/genetics ; Phylogeny ; Plants/*genetics ; Plastids/*genetics ; Rhodophyta/genetics ; Sequence Alignment ; Symbiosis/genetics ; }, abstract = {Plastids are descended from a cyanobacterial symbiosis which occurred over 1.2 billion years ago. During the course of endosymbiosis, most genes were lost from the cyanobacterium's genome and many were relocated to the host nucleus through endosymbiotic gene transfer (EGT). The issue of how many genes were acquired through EGT in different plant lineages is unresolved. Here, we report the genome-wide frequency of gene acquisitions from cyanobacteria in 4 photosynthetic eukaryotes--Arabidopsis, rice, Chlamydomonas, and the red alga Cyanidioschyzon--by comparison of the 83,138 proteins encoded in their genomes with 851,607 proteins encoded in 9 sequenced cyanobacterial genomes, 215 other reference prokaryotic genomes, and 13 reference eukaryotic genomes. The analyses entail 11,569 phylogenies inferred with both maximum likelihood and Neighbor-Joining approaches. Because each phylogenetic result is dependent not only upon the reconstruction method but also upon the site patterns in the underlying alignment, we investigated how the reliability of site pattern generation via alignment affects our results: if the site patterns in an alignment differ depending upon the order in which amino acids are introduced into multiple sequence alignment--N- to C-terminal versus C- to N-terminal--then the phylogenetic result is likely to be artifactual. Excluding unreliable alignments by this means, we obtain a conservative estimate, wherein about 14% of the proteins examined in each plant genome indicate a cyanobacterial origin for the corresponding nuclear gene, with higher proportions (17-25%) observed among the more reliable alignments. The identification of cyanobacterial genes in plant genomes affords access to an important question: from which type of cyanobacterium did the ancestor of plastids arise? Among the 9 cyanobacterial genomes sampled, Nostoc sp. PCC7120 and Anabaena variabilis ATCC29143 were found to harbor collections of genes which are-in terms of presence/absence and sequence similarity-more like those possessed by the plastid ancestor than those of the other 7 cyanobacterial genomes sampled here. This suggests that the ancestor of plastids might have been an organism more similar to filamentous, heterocyst-forming (nitrogen-fixing) representatives of section IV recognized in Stanier's cyanobacterial classification. Members of section IV are very common partners in contemporary symbiotic associations involving endosymbiotic cyanobacteria, which generally provide nitrogen to their host, consistent with suggestions that fixed nitrogen supplied by the endosymbiont might have played an important role during the origin of plastids.}, }
@article {pmid18219282, year = {2008}, author = {Halary, S and Riou, V and Gaill, F and Boudier, T and Duperron, S}, title = {3D FISH for the quantification of methane- and sulphur-oxidizing endosymbionts in bacteriocytes of the hydrothermal vent mussel Bathymodiolus azoricus.}, journal = {The ISME journal}, volume = {2}, number = {3}, pages = {284-292}, doi = {10.1038/ismej.2008.3}, pmid = {18219282}, issn = {1751-7362}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Bacteriological Techniques ; Epithelial Cells/*microbiology ; Gills/cytology/*microbiology ; Imaging, Three-Dimensional/*methods ; In Situ Hybridization, Fluorescence/*methods ; Methane/metabolism ; Mytilidae/*microbiology ; Oxidation-Reduction ; Seawater ; Sulfur/metabolism ; Symbiosis ; }, abstract = {Dual endosymbioses involving methane- and sulphur-oxidizing bacteria occur in the gills of several species of mussels from deep-sea hydrothermal vents and cold seeps. Variations of total and relative abundances of symbionts depending on local environmental parameters are not yet understood, due to a lack of reliable quantification of bacteria in the host tissue. Here, we report the first attempt to quantify volumes occupied by each type of symbiont in bacteriocyte sections from a vent mussel, Bathymodiolus azoricus, using fluorescence in situ hybridization (FISH) coupled to three dimentional microscopy and image analysis carried out by a dedicated software, which we developed. Bacteriocytes from mussels recovered at different vent sites displayed significantly different abundances of bacteria. Specimens kept in aquaria at atmospheric pressure and exposed to an artificial pulse of sulphur displayed an increase in absolute and relative abundance of sulphur oxidizers within their bacteriocytes. Distributions of all measured parameters fitted normal distributions, indicating that bacteriocytes from a specimen tend to display similar behaviours. This study shows that symbiont volume quantification is tractable using 3D FISH, and confirms the impact of local environmental parameters on symbiont abundances.}, }
@article {pmid18218025, year = {2008}, author = {Duperron, S and Laurent, MC and Gaill, F and Gros, O}, title = {Sulphur-oxidizing extracellular bacteria in the gills of Mytilidae associated with wood falls.}, journal = {FEMS microbiology ecology}, volume = {63}, number = {3}, pages = {338-349}, doi = {10.1111/j.1574-6941.2008.00438.x}, pmid = {18218025}, issn = {0168-6496}, mesh = {Adenosine Phosphosulfate/metabolism ; Animals ; Bivalvia/growth &amp; development/*microbiology ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification/metabolism ; Gills/*microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Oxidation-Reduction ; Oxidoreductases Acting on Sulfur Group Donors/genetics ; Philippines ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sequence Analysis, DNA ; Sulfur/*metabolism ; Symbiosis ; Wood/*microbiology ; }, abstract = {Six morphotypes of small mussels (Bivalvia: Mytilidae) were found attached to naturally sunken wood collected in the Bohol Sea (Philippines). These specimens are related to the large Bathymodiolus mussels that are found worldwide at cold seeps and hydrothermal vents. In these habitats, the mytilids harbour sulphur- and methane-oxidizing endosymbionts in their gills and depend on the energy and carbon provided by the symbionts. In this study, bacteria associated with the gills of wood-associated mussels are characterized using molecular and microscopic techniques. The existence of bacteria in the lateral zone of gill filaments in all specimens is demonstrated. Comparative analyses of 16S rRNA gene and adenosine 5'-phosphosulphate (APS) reductase gene sequences indicate that the bacteria are closely related to sulphur-oxidizing endosymbionts of Bathymodiolus. FISHs using specific probes confirm that sulphur oxidizers are by far the most abundant, if not the only bacteria present. Electron micrographs displayed mostly extracellular bacteria located between microvilli at the apical surface of host gill epithelial cells all along the lateral zone of each gill filament. In some specimens, occasional occurrence of intracellular bacteria with similar morphology was noted. This study provides the first molecular evidence for the presence of possible thiotrophic symbiosis in sunken wood ecosystems. With their epibiotic bacteria, wood-associated mussels display a less integrated type of interaction than described in their seep, vent and whale fall relatives.}, }
@article {pmid18208321, year = {2008}, author = {Wang, H and Benham, CJ}, title = {Superhelical destabilization in regulatory regions of stress response genes.}, journal = {PLoS computational biology}, volume = {4}, number = {1}, pages = {e17}, pmid = {18208321}, issn = {1553-7358}, support = {R01 GM068903/GM/NIGMS NIH HHS/United States ; R01-GM68903/GM/NIGMS NIH HHS/United States ; }, mesh = {Computer Simulation ; *DNA Damage ; DNA, Bacterial/*chemistry/*genetics ; DNA-Binding Proteins/*chemistry/*genetics ; Heat Shock Transcription Factors ; *Models, Chemical ; *Models, Genetic ; Models, Molecular ; Nucleic Acid Conformation ; Regulatory Sequences, Nucleic Acid/*genetics ; Transcription Factors/*chemistry/*genetics ; }, abstract = {Stress-induced DNA duplex destabilization (SIDD) analysis exploits the known structural and energetic properties of DNA to predict sites that are susceptible to strand separation under negative superhelical stress. When this approach was used to calculate the SIDD profile of the entire Escherichia coli K12 genome, it was found that strongly destabilized sites occur preferentially in intergenic regions that are either known or inferred to contain promoters, but rarely occur in coding regions. Here, we investigate whether the genes grouped in different functional categories have characteristic SIDD properties in their upstream flanks. We report that strong SIDD sites in the E. coli K12 genome are statistically significantly overrepresented in the upstream regions of genes encoding transcriptional regulators. In particular, the upstream regions of genes that directly respond to physiological and environmental stimuli are more destabilized than are those regions of genes that are not involved in these responses. Moreover, if a pathway is controlled by a transcriptional regulator whose gene has a destabilized 5' flank, then the genes (operons) in that pathway also usually contain strongly destabilized SIDD sites in their 5' flanks. We observe this statistically significant association of SIDD sites with upstream regions of genes functioning in transcription in 38 of 43 genomes of free-living bacteria, but in only four of 18 genomes of endosymbionts or obligate parasitic bacteria. These results suggest that strong SIDD sites 5' to participating genes may be involved in transcriptional responses to environmental changes, which are known to transiently alter superhelicity. We propose that these SIDD sites are active and necessary participants in superhelically mediated regulatory mechanisms governing changes in the global pattern of gene expression in prokaryotes in response to physiological or environmental changes.}, }
@article {pmid18194581, year = {2008}, author = {Moustafa, A and Bhattacharya, D}, title = {PhyloSort: a user-friendly phylogenetic sorting tool and its application to estimating the cyanobacterial contribution to the nuclear genome of Chlamydomonas.}, journal = {BMC evolutionary biology}, volume = {8}, number = {}, pages = {6}, pmid = {18194581}, issn = {1471-2148}, support = {T32 GM008629/GM/NIGMS NIH HHS/United States ; R01ES013679/ES/NIEHS NIH HHS/United States ; }, mesh = {Animals ; Chlamydomonas reinhardtii/classification/*genetics ; Cyanobacteria/*genetics ; Expressed Sequence Tags ; *Gene Transfer, Horizontal ; Genome, Bacterial ; Genome, Protozoan ; Genomics ; *Phylogeny ; Plastids/*genetics ; Symbiosis/genetics ; User-Computer Interface ; }, abstract = {BACKGROUND: Phylogenomic pipelines generate a large collection of phylogenetic trees that require manual inspection to answer questions about gene or genome evolution. A notable application of phylogenomics is to photosynthetic organelle (plastid) endosymbiosis. In the case of primary endosymbiosis, a heterotrophic protist engulfed a cyanobacterium, giving rise to the first photosynthetic eukaryote. Plastid establishment precipitated extensive gene transfer from the endosymbiont to the nuclear genome of the 'host'. Estimating the magnitude of this endosymbiotic gene transfer (EGT) and determining the functions of the prokaryotic genes remain controversial issues. We used phylogenomics to study EGT in the model green alga Chlamydomonas reinhardtii. To facilitate this procedure, we developed PhyloSort to rapidly search large collection of trees for monophyletic relationships. Here we present PhyloSort and its application to estimating EGT in Chlamydomonas.<br><br>RESULTS: PhyloSort is an open-source tool to sort phylogenetic trees by searching for user specified subtrees that contain a monophyletic group of interest defined by operational taxonomic units in a phylogenomic context. Using PhyloSort, we identified 897 Chlamydomonas genes of putative cyanobacterial origin, of which 531 had bootstrap support values >/= 50% for the grouping of the algal and cyanobacterial homologs.<br><br>CONCLUSION: PhyloSort can be applied to quantify the number of genes that support different evolutionary hypotheses such as a taxonomic classification or endosymbiotic or horizontal gene transfer events. In our application, we demonstrate that cyanobacteria account for 3.5-6% of the protein-coding genes in the nuclear genome of Chlamydomonas.}, }
@article {pmid18194345, year = {2008}, author = {Muresu, R and Polone, E and Sulas, L and Baldan, B and Tondello, A and Delogu, G and Cappuccinelli, P and Alberghini, S and Benhizia, Y and Benhizia, H and Benguedouar, A and Mori, B and Calamassi, R and Dazzo, FB and Squartini, A}, title = {Coexistence of predominantly nonculturable rhizobia with diverse, endophytic bacterial taxa within nodules of wild legumes.}, journal = {FEMS microbiology ecology}, volume = {63}, number = {3}, pages = {383-400}, doi = {10.1111/j.1574-6941.2007.00424.x}, pmid = {18194345}, issn = {0168-6496}, mesh = {Algeria ; Bacteria/*classification/*growth &amp; development ; Culture Media ; DNA, Bacterial/analysis ; Enterobacter/growth &amp; development ; Fabaceae/classification/*microbiology ; Italy ; Microscopy, Fluorescence ; *Nitrogen Fixation ; Plant Roots/*microbiology/ultrastructure ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Rhizobiaceae/classification/genetics/*growth &amp; development/isolation &amp; purification ; Symbiosis ; }, abstract = {A previous analysis showed that Gammaproteobacteria could be the sole recoverable bacteria from surface-sterilized nodules of three wild species of Hedysarum. In this study we extended the analysis to eight Mediterranean native, uninoculated legumes never previously investigated regarding their root-nodule microsymbionts. The structural organization of the nodules was studied by light and electron microscopy, and their bacterial occupants were assessed by combined cultural and molecular approaches. On examination of 100 field-collected nodules, culturable isolates of rhizobia were hardly ever found, whereas over 24 other bacterial taxa were isolated from nodules. None of these nonrhizobial isolates could nodulate the original host when reinoculated in gnotobiotic culture. Despite the inability to culture rhizobial endosymbionts from within the nodules using standard culture media, a direct 16S rRNA gene PCR analysis revealed that most of these nodules contained rhizobia as the predominant population. The presence of nodular endophytes colocalized with rhizobia was verified by immunofluorescence microscopy of nodule sections using an Enterobacter-specific antibody. Hypotheses to explain the nonculturability of rhizobia are presented, and pertinent literature on legume endophytes is discussed.}, }
@article {pmid18185591, year = {2008}, author = {Nagamune, K and Hicks, LM and Fux, B and Brossier, F and Chini, EN and Sibley, LD}, title = {Abscisic acid controls calcium-dependent egress and development in Toxoplasma gondii.}, journal = {Nature}, volume = {451}, number = {7175}, pages = {207-210}, pmid = {18185591}, issn = {1476-4687}, support = {R01 AI034036/AI/NIAID NIH HHS/United States ; R01 AI034036-16/AI/NIAID NIH HHS/United States ; R21 AI067051/AI/NIAID NIH HHS/United States ; R21 AI067051-02/AI/NIAID NIH HHS/United States ; }, mesh = {Abscisic Acid/analysis/biosynthesis/*metabolism/pharmacology ; Animals ; Calcium/*metabolism ; *Calcium Signaling/drug effects ; Cyclic ADP-Ribose/biosynthesis/metabolism ; Disease Models, Animal ; Mice ; Mice, Inbred BALB C ; Plant Growth Regulators ; Protozoan Proteins/metabolism ; Pyridones/pharmacology ; Toxoplasma/drug effects/*growth &amp; development/*metabolism/pathogenicity ; Toxoplasmosis/parasitology/pathology/prevention &amp; control ; }, abstract = {Calcium controls a number of critical events, including motility, secretion, cell invasion and egress by apicomplexan parasites. Compared to animal and plant cells, the molecular mechanisms that govern calcium signalling in parasites are poorly understood. Here we show that the production of the phytohormone abscisic acid (ABA) controls calcium signalling within the apicomplexan parasite Toxoplasma gondii, an opportunistic human pathogen. In plants, ABA controls a number of important events, including environmental stress responses, embryo development and seed dormancy. ABA induces production of the second-messenger cyclic ADP ribose (cADPR), which controls release of intracellular calcium stores in plants. cADPR also controls intracellular calcium release in the protozoan parasite T. gondii; however, previous studies have not revealed the molecular basis of this pathway. We found that addition of exogenous ABA induced formation of cADPR in T. gondii, stimulated calcium-dependent protein secretion, and induced parasite egress from the infected host cell in a density-dependent manner. Production of endogenous ABA within the parasite was confirmed by purification (using high-performance liquid chromatography) and analysis (by gas chromatography-mass spectrometry). Selective disruption of ABA synthesis by the inhibitor fluridone delayed egress and induced development of the slow-growing, dormant cyst stage of the parasite. Thus, ABA-mediated calcium signalling controls the decision between lytic and chronic stage growth, a developmental switch that is central in pathogenesis and transmission. The pathway for ABA production was probably acquired with an algal endosymbiont that was retained as a non-photosynthetic plastid known as the apicoplast. The plant-like nature of this pathway may be exploited therapeutically, as shown by the ability of a specific inhibitor of ABA synthesis to prevent toxoplasmosis in the mouse model.}, }
@article {pmid18180957, year = {2008}, author = {Shakya, S and Bajpai, P and Sharma, S and Misra-Bhattacharya, S}, title = {Prior killing of intracellular bacteria Wolbachia reduces inflammatory reactions and improves antifilarial efficacy of diethylcarbamazine in rodent model of Brugia malayi.}, journal = {Parasitology research}, volume = {102}, number = {5}, pages = {963-972}, pmid = {18180957}, issn = {0932-0113}, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage/pharmacology/*therapeutic use ; *Brugia malayi/drug effects/microbiology ; Diethylcarbamazine/administration &amp; dosage/*therapeutic use ; Disease Models, Animal ; Drug Administration Schedule ; Drug Therapy, Combination ; Female ; Filariasis/*drug therapy/immunology/parasitology ; Filaricides/administration &amp; dosage/*therapeutic use ; Gerbillinae ; Host-Parasite Interactions ; Humans ; Inflammation/drug therapy/immunology/parasitology ; Male ; Murinae ; Tetracycline/administration &amp; dosage/pharmacology/*therapeutic use ; Treatment Outcome ; Wolbachia/*drug effects ; }, abstract = {The discovery of the endosymbiont Wolbachia, which has a mutualistic relationship with filarial nematodes, and its importance in filarial parasite biology has provided a lead for developing novel chemotherapeutic agents against human filariasis. Wolbachia also appears to be involved in immunopathological responses as well as adverse reactions after antifilarial therapy. The aim of the present study was to explore the potential of administering anti-Wolbachial therapy before antifilarial treatment to improve the filaricidal efficacy of the present-day filaricide diethylcarbamazine. An additional objective was to minimize host inflammatory reactions using a rodent model Mastomys coucha and Meriones unguiculatus infected with human lymphatic filariid Brugia malayi. We observed: (1) a 40-day treatment schedule of tetracycline alone resulted in delayed reduction in microfilaraemia and a low degree of macrofilaricidal efficacy; (2) tetracycline therapy followed by 100 mg/kg diethylcarbamazine (DEC) x5 days led to marked reduction in microfilaraemia from day 48 onward after initiation of treatment. The combination treatment also brought about approximately 70% death of adult B. malayi and sterilization of 82.3% of the surviving female worms, thus exhibiting remarkable enhancement in the antifilarial activity of DEC; (3) tissue inflammatory reactions and pathogenesis were significantly reduced as observed by histopathology, and peritoneal macrophage mediated oxidative burst shown by fluorescence-activated cell sorting (FACS) analysis using dichlorofluorescein diacetate (DCF-DA); and (4) the characteristic filarial antigen-specific and mitogen-specific cellular unresponsiveness was significantly reversed, possibly due to marked clearance of microfilaraemia. It is therefore advisable to give an anti-Wolbachial antibiotic trial before starting antifilarial therapy to achieve maximum benefits.}, }
@article {pmid18180748, year = {2008}, author = {Briones, AM and Shililu, J and Githure, J and Novak, R and Raskin, L}, title = {Thorsellia anophelis is the dominant bacterium in a Kenyan population of adult Anopheles gambiae mosquitoes.}, journal = {The ISME journal}, volume = {2}, number = {1}, pages = {74-82}, doi = {10.1038/ismej.2007.95}, pmid = {18180748}, issn = {1751-7362}, support = {U01A1054889//PHS HHS/United States ; }, mesh = {Animals ; Anopheles/growth &amp; development/*microbiology ; Culicidae/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Enterobacteriaceae/classification/genetics/*isolation &amp; purification ; Female ; Kenya ; Larva/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Anopheles gambiae mosquitoes are not known to harbor endosymbiotic bacteria. Here we show, using nucleic acid-based methods, that 16S rRNA gene sequences specific to a recently described mosquito midgut bacterium, Thorsellia anophelis, is predominant in the midgut of adult An. gambiae s.l. mosquitoes captured in residences in central Kenya, and also occurs in the aquatic rice paddy environment nearby. PCR consistently detected T. anophelis in the surface microlayer of rice paddies, which is also consistent with the surface-feeding behavior of A. gambiae s.l. larvae. Phylogenetic analysis of cloned environmental 16S rRNA genes identified four major Thorsellia lineages, which are closely affiliated to an insect endosymbiont of the genus Arsenophonus. Physiological characterizations support the hypothesis that T. anophelis is well adapted to the female anopheline midgut by utilizing blood and tolerating the alkaline conditions in this environment. The results suggest that aquatically derived bacteria such as T. anophelis can persist through mosquito metamorphosis and become well-established in the adult mosquito midgut.}, }
@article {pmid18179432, year = {2008}, author = {Baldo, L and Ayoub, NA and Hayashi, CY and Russell, JA and Stahlhut, JK and Werren, JH}, title = {Insight into the routes of Wolbachia invasion: high levels of horizontal transfer in the spider genus Agelenopsis revealed by Wolbachia strain and mitochondrial DNA diversity.}, journal = {Molecular ecology}, volume = {17}, number = {2}, pages = {557-569}, doi = {10.1111/j.1365-294X.2007.03608.x}, pmid = {18179432}, issn = {0962-1083}, mesh = {Animals ; DNA, Mitochondrial/*genetics ; Gene Transfer, Horizontal/*genetics ; Genetic Variation ; Geography ; Haplotypes ; Host-Pathogen Interactions ; Phylogeny ; Spiders/classification/*genetics/microbiology ; United States ; Wolbachia/*genetics ; }, abstract = {The pandemic distribution of Wolbachia (alpha-proteobacteria) across arthropods is largely due to the ability of these maternally inherited endosymbionts to successfully shift hosts across species boundaries. Yet it remains unclear whether Wolbachia has preferential routes of transfer among species. Here, we examined populations of eight species of the North American funnel-web spider genus Agelenopsis to evaluate whether Wolbachia show evidence for host specificity and the relative contribution of horizontal vs. vertical transmission of strains within and among related host species. Wolbachia strains were characterized by multilocus sequence typing (MLST) and Wolbachia surface protein (WSP) sequences, and analysed in relation to host phylogeny, mitochondrial diversity and geographical range. Results indicate that at least three sets of divergent Wolbachia strains invaded the genus Agelenopsis. After each invasion, the Wolbachia strains preferentially shuffled across species of this host genus by horizontal transfer rather than cospeciation. Decoupling of Wolbachia and host mitochondrial haplotype (mitotypes) evolutionary histories within single species reveals an extensive contribution of horizontal transfer also in the rapid dispersal of Wolbachia among conspecific host populations. These findings provide some of the strongest evidence to support the association of related Wolbachia strains with related hosts by means of both vertical and horizontal strain transmission. Similar analyses across a broader range of invertebrate taxa are needed, using sensitive methods for strain typing such as MLST, to determine if this pattern of Wolbachia dispersal is peculiar to Agelenopsis (or spiders), or is in fact a general pattern in arthropods.}, }
@article {pmid18179430, year = {2008}, author = {Degnan, PH and Moran, NA}, title = {Evolutionary genetics of a defensive facultative symbiont of insects: exchange of toxin-encoding bacteriophage.}, journal = {Molecular ecology}, volume = {17}, number = {3}, pages = {916-929}, doi = {10.1111/j.1365-294X.2007.03616.x}, pmid = {18179430}, issn = {1365-294X}, mesh = {Animals ; Aphids/*microbiology ; Bacterial Toxins/*genetics/metabolism ; Bacteriophages/*genetics/metabolism ; DNA, Bacterial/chemistry/genetics ; Enterobacteriaceae/*genetics/*virology ; *Evolution, Molecular ; Markov Chains ; Monte Carlo Method ; Phylogeny ; Polymerase Chain Reaction ; Symbiosis ; }, abstract = {The facultative endosymbiont of aphids, Hamiltonella defensa, kills parasitoid wasp larvae, allowing aphid hosts to survive and reproduce. This protection may depend on toxins that are encoded by the genomes of H. defensa and of its bacteriophage (APSE). Strains of H. defensa vary in degree of protection conferred upon Acyrthosiphon pisum (pea aphid). Although H. defensa is known to undergo some horizontal transmission among aphid maternal lineages, divergence, recombination, and population structure in H. defensa and APSE have not been characterized. We performed a multilocus sequence analysis of 10 bacterial and five phage loci for strains isolated from A. pisum and other aphid species. The H. defensa chromosome was found to be largely clonal, allowing us to generate a well-resolved H. defensa strain phylogeny. In contrast, APSE chromosomes undergo recombination and numerous H. defensa strains have probably lost the phage. Within a set of H. defensa strains that are indistinguishable on the basis of chromosomal genes or restriction digests of chromosomal fragments, loss of APSE is associated with decreased protection, strongly suggesting that APSE-encoded genes contribute to the defensive phenotype. Thus, homologous recombination of APSE genes and sexual transmission of symbionts and phage are likely factors influencing the exchange of ecologically important genes among symbionts. Although H. defensa has been lost, transferred and gained within A. pisum, one subclade of H. defensa appears to be universal within a subclade of the aphid genus Uroleucon, suggesting a transition from facultative, horizontal transmission to strictly vertical inheritance.}, }
@article {pmid18171476, year = {2008}, author = {Xi, Z and Gavotte, L and Xie, Y and Dobson, SL}, title = {Genome-wide analysis of the interaction between the endosymbiotic bacterium Wolbachia and its Drosophila host.}, journal = {BMC genomics}, volume = {9}, number = {}, pages = {1}, pmid = {18171476}, issn = {1471-2164}, support = {R01 AI051533/AI/NIAID NIH HHS/United States ; AI-51533/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cell Line ; Down-Regulation ; Drosophila/*genetics/immunology/*microbiology ; Female ; Gene Expression Profiling ; Genome, Insect/*genetics ; Gonads/enzymology ; Gram-Negative Bacterial Infections/genetics ; Heat-Shock Proteins/genetics ; Host-Pathogen Interactions/*genetics ; Male ; *Oligonucleotide Array Sequence Analysis ; Peptidyl-Dipeptidase A/genetics ; Phenotype ; Reproduction/genetics ; Sex Characteristics ; Symbiosis/*genetics ; Up-Regulation ; Wolbachia/*physiology ; }, abstract = {BACKGROUND: Intracellular Wolbachia bacteria are obligate, maternally-inherited, endosymbionts found frequently in insects and other invertebrates. The success of Wolbachia can be attributed in part to an ability to alter host reproduction via mechanisms including cytoplasmic incompatibility (CI), parthenogenesis, feminization and male killing. Despite substantial scientific effort, the molecular mechanisms underlying the Wolbachia/host interaction are unknown.<br><br>RESULTS: Here, an in vitro Wolbachia infection was generated in the Drosophila S2 cell line, and transcription profiles of infected and uninfected cells were compared by microarray. Differentially-expressed patterns related to reproduction, immune response and heat stress response are observed, including multiple genes that have been previously reported to be involved in the Wolbachia/host interaction. Subsequent in vivo characterization of differentially-expressed products in gonads demonstrates that Angiotensin Converting Enzyme (Ance) varies between Wolbachia infected and uninfected flies and that the variation occurs in a sex-specific manner. Consistent with expectations for the conserved CI mechanism, the observed Ance expression pattern is repeatable in different Drosophila species and with different Wolbachia types. To examine Ance involvement in the CI phenotype, compatible and incompatible crosses of Ance mutant flies were conducted. Significant differences are observed in the egg hatch rate resulting from incompatible crosses, providing support for additional experiments examining for an interaction of Ance with the CI mechanism.<br><br>CONCLUSION: Wolbachia infection is shown to affect the expression of multiple host genes, including Ance. Evidence for potential Ance involvement in the CI mechanism is described, including the prior report of Ance in spermatid differentiation, Wolbachia-induced sex-specific effects on Ance expression and an Ance mutation effect on CI levels. The results support the use of Wolbachia infected cell cultures as an appropriate model for predicting in vivo host/Wolbachia interactions.}, }
@article {pmid18167542, year = {2008}, author = {Hampl, V and Silberman, JD and Stechmann, A and Diaz-Triviño, S and Johnson, PJ and Roger, AJ}, title = {Genetic evidence for a mitochondriate ancestry in the 'amitochondriate' flagellate Trimastix pyriformis.}, journal = {PloS one}, volume = {3}, number = {1}, pages = {e1383}, pmid = {18167542}, issn = {1932-6203}, mesh = {Amino Acid Sequence ; Amino Acids/metabolism ; Animals ; DNA, Mitochondrial/*genetics ; Energy Metabolism ; Eukaryota/classification/*genetics/metabolism ; Expressed Sequence Tags ; Molecular Sequence Data ; Phylogeny ; Protein Transport ; Sequence Homology, Amino Acid ; }, abstract = {Most modern eukaryotes diverged from a common ancestor that contained the alpha-proteobacterial endosymbiont that gave rise to mitochondria. The 'amitochondriate' anaerobic protist parasites that have been studied to date, such as Giardia and Trichomonas harbor mitochondrion-related organelles, such as mitosomes or hydrogenosomes. Yet there is one remaining group of mitochondrion-lacking flagellates known as the Preaxostyla that could represent a primitive 'pre-mitochondrial' lineage of eukaryotes. To test this hypothesis, we conducted an expressed sequence tag (EST) survey on the preaxostylid flagellate Trimastix pyriformis, a poorly-studied free-living anaerobe. Among the ESTs we detected 19 proteins that, in other eukaryotes, typically function in mitochondria, hydrogenosomes or mitosomes, 12 of which are found exclusively within these organelles. Interestingly, one of the proteins, aconitase, functions in the tricarboxylic acid cycle typical of aerobic mitochondria, whereas others, such as pyruvate:ferredoxin oxidoreductase and [FeFe] hydrogenase, are characteristic of anaerobic hydrogenosomes. Since Trimastix retains genetic evidence of a mitochondriate ancestry, we can now say definitively that all known living eukaryote lineages descend from a common ancestor that had mitochondria.}, }
@article {pmid18093159, year = {2008}, author = {Duperron, S and Halary, S and Lorion, J and Sibuet, M and Gaill, F}, title = {Unexpected co-occurrence of six bacterial symbionts in the gills of the cold seep mussel Idas sp. (Bivalvia: Mytilidae).}, journal = {Environmental microbiology}, volume = {10}, number = {2}, pages = {433-445}, doi = {10.1111/j.1462-2920.2007.01465.x}, pmid = {18093159}, issn = {1462-2920}, mesh = {Animals ; Bacteroidetes/classification/genetics/growth &amp; development/*isolation &amp; purification ; Cold Temperature ; DNA, Bacterial/analysis ; Gammaproteobacteria/classification/genetics/growth &amp; development/*isolation &amp; purification ; Gills/*microbiology ; In Situ Hybridization, Fluorescence ; Mediterranean Sea ; Molecular Sequence Data ; Mytilidae/genetics/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Bathymodioline mussels occur in chemosynthesis-based ecosystems such as cold seeps, hydrothermal vents and organic debris worldwide. Their key adaptation to these environments is their association with bacterial endosymbionts which ensure a chemosynthetic primary production based on the oxidation of reduced compounds such as methane and sulfide. We herein report a multiple symbiosis involving six distinct bacterial 16S rRNA phylotypes, including two belonging to groups not yet reported as symbionts in mytilids, in a small Idas mussel found on carbonate crusts in a cold seep area located north to the Nile deep-sea fan (Eastern Mediterranean). Symbionts co-occur within hosts bacteriocytes based on fluorescence in situ hybridizations, and sequencing of functional genes suggests they have the potential to perform autotrophy, and sulfide and methane oxidation. Previous studies indicated the presence of only one or two symbiont 16S rRNA phylotypes in bathymodioline mussels. Together with the recent discovery of four bacterial symbionts in the large seep species Bathymodiolus heckerae, this study shows that symbiont diversity has probably been underestimated, and questions whether the common ancestor of bathymodioline mussels was associated with multiple bacteria.}, }
@article {pmid18092388, year = {1999}, author = {Cavalier-Smith, T}, title = {Principles of protein and lipid targeting in secondary symbiogenesis: euglenoid, dinoflagellate, and sporozoan plastid origins and the eukaryote family tree.}, journal = {The Journal of eukaryotic microbiology}, volume = {46}, number = {4}, pages = {347-366}, doi = {10.1111/j.1550-7408.1999.tb04614.x}, pmid = {18092388}, issn = {1066-5234}, mesh = {Animals ; Apicomplexa/*physiology ; Biological Evolution ; Dinoflagellida/*physiology ; Euglenida/*physiology ; Eukaryotic Cells ; Lipids/physiology ; Plastids/*physiology ; Protozoan Proteins/physiology ; *Symbiosis ; }, abstract = {The biggest unsolved problems in chloroplast evolution are the origins of dinoflagellate and euglenoid chloroplasts,which have envelopes of three membranes not two like plants and chromists, and of the sporozoan plastid, bounded by four smooth membranes. I review evidence that all three of these protozoan plastid types originated by secondary symbiogenesis from eukaryotic symbionts. Instead of separate symbiogenetic events, I argue that dinoflagellate and sporozoan plastids are directly related and that the common ancestor of dinoflagellates and Sporozoa was photosynthetic. I suggest that the last common ancestor of all Alveolata was photosynthetic and acquired its chlorophyll c-containing plastids in the same endosymbiogenetic event as those of Chromista. Chromistaand Alveolata are postulated to be a clade designated chrornalveolates. I propose that euglenoids obtained their plastids from the same(possibly ulvophycean) green alga as chlorarachneans and that Discicristata (Euglenozoa plus Percolozoa) and Cercozoa (the group including chlorarachneans) form a clade designated cabozoa (protozoa with chlorophyll a + b). If both theories are correct, there were only two secondary symbiogenetic events (witnessed by the chlorarachnean and cryptomonad nucleormorphs) in the history of life, not seven as commonly assumed. This greatly reduces the postulated number of independent origins of chloroplast protein-targeting machinery and of gene transfers from endosymbiont to host nuclei. I discuss the membrane and plastid losses and innovations in protein targeting implied by these theories, the comparative evidence for them, and their implications for eukaryote megaphylogeny. The principle of evolutionary conservatism leads to a novel theory for the function of periplastid vesicles in membrane biogenesis ofchlorarachneans and chromists and of the key steps in secondary symbiogenesis. Protozoan classification is also slightly revised by abandoning the probably polyphyletic infrakingdom Actinopoda, grouping Foraminifera and Radiolaria as a new infrakingdom Retaria,placing Heliozoa within a revised infrakingdom Sarcomastigota, establishing a new flagellate phylum Loukozoa for Jakobea plus Anaeromonadea within an emended subkingdom Eozoa, and ranking Archezoa as an infrakingdom within Eozoa.}, }
@article {pmid18089010, year = {2003}, author = {Koteja, J and Pyka-Fościak, G and Vogelgesang, M and Szklarzewicz, T}, title = {Structure of the ovary in Steingelia (Sternorrhyncha: Coccinea), and its phylogenetic implications.}, journal = {Arthropod structure &amp; development}, volume = {32}, number = {2-3}, pages = {247-256}, doi = {10.1016/S1467-8039(03)00046-X}, pmid = {18089010}, issn = {1873-5495}, abstract = {The paired ovaries of Steingelia gorodetskia are composed of about 100 telotrophic ovarioles devoid of terminal filaments (scale insect autapomorphy). In structure they resemble those of other scale insects, but differ in the following details: (a) all ovarioles develop synchronously, (b) they are suspended to the lateral oviducts by means of long stalks, (c) the tropharium is tubular (unique in scale insects) and (d) consists of 15-35, trophocytes, 2-4 previtellogenic oocytes that further develop, and numerous somatic prefollicular cells, (e) the vitellarium houses 2-4 linearly arranged vitellarial oocytes (versus one in most scale insects). Most of these features must be considered as plesiomorphic corresponding with the conditions in the most primitive Heteroptera. Bacterial endosymbionts have been found in some somatic cells, trophocytes, oocytes and in the nutritive cord. Present results support the opinion, based on external morphology, that the Steingeliidae are closely related to the Ortheziidae, Xylococcidae and Matsucoccidae.}, }
@article {pmid18077423, year = {2007}, author = {Lane, CE and van den Heuvel, K and Kozera, C and Curtis, BA and Parsons, BJ and Bowman, S and Archibald, JM}, title = {Nucleomorph genome of Hemiselmis andersenii reveals complete intron loss and compaction as a driver of protein structure and function.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {104}, number = {50}, pages = {19908-19913}, pmid = {18077423}, issn = {1091-6490}, mesh = {Algal Proteins/*chemistry/*genetics/physiology ; Cell Nucleus/*genetics ; Cryptophyta/*chemistry/*genetics ; *Evolution, Molecular ; *Genome ; Introns/*genetics ; Molecular Sequence Data ; Structure-Activity Relationship ; Symbiosis ; }, abstract = {Nucleomorphs are the remnant nuclei of algal endosymbionts that took up residence inside a nonphotosynthetic eukaryotic host. The nucleomorphs of cryptophytes and chlorarachniophytes are derived from red and green algal endosymbionts, respectively, and represent a stunning example of convergent evolution: their genomes have independently been reduced and compacted to <1 megabase pairs (Mbp) in size (the smallest nuclear genomes known) and to a similar three-chromosome architecture. The molecular processes underlying genome reduction and compaction in eukaryotes are largely unknown, as is the impact of reduction/compaction on protein structure and function. Here, we present the complete 0.572-Mbp nucleomorph genome of the cryptophyte Hemiselmis andersenii and show that it is completely devoid of spliceosomal introns and genes for splicing RNAs-a case of complete intron loss in a nuclear genome. Comparison of H. andersenii proteins to those encoded in the slightly smaller (0.551-Mbp) nucleomorph genome of another cryptophyte, Guillardia theta, and to their homologs in the unicellular red alga Cyanidioschyzon merolae reveal that (i) cryptophyte nucleomorph genomes encode proteins that are significantly smaller than those in their free-living algal ancestors, and (ii) the smaller, more compact G. theta nucleomorph genome encodes significantly smaller proteins than that of H. andersenii. These results indicate that genome compaction can eliminate both coding and noncoding DNA and, consequently, drive the evolution of protein structure and function. Nucleomorph proteins have the potential to reveal the minimal functional units required for basic eukaryotic cellular processes.}, }
@article {pmid18073380, year = {2008}, author = {Nikoh, N and Tanaka, K and Shibata, F and Kondo, N and Hizume, M and Shimada, M and Fukatsu, T}, title = {Wolbachia genome integrated in an insect chromosome: evolution and fate of laterally transferred endosymbiont genes.}, journal = {Genome research}, volume = {18}, number = {2}, pages = {272-280}, pmid = {18073380}, issn = {1088-9051}, mesh = {Animals ; Base Sequence ; Blotting, Southern ; Chromosome Mapping ; Chromosomes/*genetics ; Coleoptera/genetics/*microbiology ; *Evolution, Molecular ; Gene Transfer, Horizontal/*genetics ; Genome/*genetics ; In Situ Hybridization, Fluorescence ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Pseudogenes/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*genetics ; }, abstract = {Recent accumulation of microbial genome data has demonstrated that lateral gene transfers constitute an important and universal evolutionary process in prokaryotes, while those in multicellular eukaryotes are still regarded as unusual, except for endosymbiotic gene transfers from mitochondria and plastids. Here we thoroughly investigated the bacterial genes derived from a Wolbachia endosymbiont on the nuclear genome of the beetle Callosobruchus chinensis. Exhaustive PCR detection and Southern blot analysis suggested that approximately 30% of Wolbachia genes, in terms of the gene repertoire of wMel, are present on the insect nuclear genome. Fluorescent in situ hybridization located the transferred genes on the proximal region of the basal short arm of the X chromosome. Molecular evolutionary and other lines of evidence indicated that the transferred genes are probably derived from a single lateral transfer event. The transferred genes were, for the length examined, structurally disrupted, freed from functional constraints, and transcriptionally inactive. Hence, most, if not all, of the transferred genes have been pseudogenized. Notwithstanding this, the transferred genes were ubiquitously detected from Japanese and Taiwanese populations of C. chinensis, while the number of the transferred genes detected differed between the populations. The transferred genes were not detected from congenic beetle species, indicating that the transfer event occurred after speciation of C. chinensis, which was estimated to be one or several million years ago. These features of the laterally transferred endosymbiont genes are compared with the evolutionary patterns of mitochondrial and plastid genome fragments acquired by nuclear genomes through recent endosymbiotic gene transfers.}, }
@article {pmid18071758, year = {2008}, author = {Shanmughapriya, S and Krishnaveni, J and Selvin, J and Gandhimathi, R and Arunkumar, M and Thangavelu, T and Kiran, GS and Natarajaseenivasan, K}, title = {Optimization of extracellular thermotolerant alkaline protease produced by marine Roseobacter sp. (MMD040).}, journal = {Bioprocess and biosystems engineering}, volume = {31}, number = {5}, pages = {427-433}, doi = {10.1007/s00449-007-0179-z}, pmid = {18071758}, issn = {1615-7591}, mesh = {Bacterial Proteins/*chemistry/*metabolism ; *Bioreactors ; Cell Culture Techniques/*methods ; Endopeptidases/*chemistry/*metabolism ; Enzyme Activation ; Enzyme Stability ; Extracellular Fluid/metabolism ; Hydrogen-Ion Concentration ; Marine Biology ; Quality Control ; Roseobacter/*enzymology ; Temperature ; }, abstract = {Marine endosymbiontic Roseobacter sp. (MMD040), which produced high yields of protease, was isolated from marine sponge Fasciospongia cavernosa, collected from the peninsular coast of India. Maximum production of enzyme was obtained in Luria-Bertani broth. Catabolite repression was observed when the medium was supplemented with readily available carbon sources. The optimum temperature and pH for the enzyme production was 37 degrees C and 7.0, respectively. The enzyme exhibited maximum activity in pH range of 6-9 with an optimum pH of 8.0 and retained nearly 92.5% activity at pH 9.0. The enzyme was stable at 40 degrees C and showed 89% activity at 50 degrees C. Based on the present findings, the enzyme was characterized as thermotolerant alkaline protease, which can be developed for industrial applications.}, }
@article {pmid18070083, year = {2008}, author = {O'Fallon, B}, title = {Population structure, levels of selection, and the evolution of intracellular symbionts.}, journal = {Evolution; international journal of organic evolution}, volume = {62}, number = {2}, pages = {361-373}, doi = {10.1111/j.1558-5646.2007.00289.x}, pmid = {18070083}, issn = {0014-3820}, mesh = {Alleles ; Animals ; Bacteria/genetics ; *Biological Evolution ; *Evolution, Molecular ; *Genetics, Population ; Insecta/*microbiology ; Models, Genetic ; Models, Statistical ; *Mutation ; Probability ; RNA/*chemistry ; *Selection, Genetic ; *Symbiosis ; }, abstract = {Many obligately intracellular symbionts exhibit a characteristic set of genetic changes that include an increase in substitution rates, loss of many genes, and apparent destabilization of many proteins and structural RNAs. Authors have suggested that these changes are due to increased mutation rates, or, more commonly, decreased effective population size due to population bottlenecks at the symbiont or, perhaps, host level. I propose that the increase in substitution rates and accumulation of deleterious mutations is a consequence of the population structure imposed on the endosymbionts by strict host association, loss of horizontal transmission and potentially conflicting levels of selection. I analyze a population genetic model of endosymbiont evolution, and demonstrate that substitution rates will increase, and the effect of those substitutions on endosymbiont fitness will become more deleterious as horizontal transmission among hosts decreases. Additionally, I find that there is a critical level of horizontal transmission below which natural selection cannot effectively purge deleterious mutations, leading to an expected loss of fitness over time. This critical level varies across loci with the degree of correlation between host and endosymbiont fitness, and may help explain differential retention and loss of certain genes.}, }
@article {pmid18055594, year = {2008}, author = {MacLean, AM and Anstey, MI and Finan, TM}, title = {Binding site determinants for the LysR-type transcriptional regulator PcaQ in the legume endosymbiont Sinorhizobium meliloti.}, journal = {Journal of bacteriology}, volume = {190}, number = {4}, pages = {1237-1246}, pmid = {18055594}, issn = {1098-5530}, mesh = {Agrobacterium tumefaciens/genetics ; Bacterial Proteins/genetics/*metabolism ; Base Sequence ; Binding Sites/genetics ; DNA Fingerprinting ; Electrophoretic Mobility Shift Assay ; Fabaceae/*microbiology ; Gene Expression Regulation, Bacterial/genetics ; Lac Operon/genetics ; Models, Genetic ; Molecular Sequence Data ; Mutagenesis, Site-Directed ; Operon/genetics ; Protein Binding ; Recombinant Fusion Proteins/genetics/metabolism ; Rhizobium etli/genetics/growth &amp; development/metabolism ; Rhizobium leguminosarum/genetics/growth &amp; development/metabolism ; Sequence Homology, Amino Acid ; Sinorhizobium meliloti/genetics/growth &amp; development/*metabolism ; Trans-Activators/genetics/*metabolism ; Transcription Initiation Site ; Transcription, Genetic ; }, abstract = {LysR-type transcriptional regulators represent one of the largest groups of prokaryotic regulators described to date. In the gram-negative legume endosymbiont Sinorhizobium meliloti, enzymes involved in the protocatechuate branch of the beta-ketoadipate pathway are encoded within the pcaDCHGB operon, which is subject to regulation by the LysR-type protein PcaQ. In this work, purified PcaQ was shown to bind strongly (equilibrium dissociation constant, 0.54 nM) to a region at positions -78 to -45 upstream of the pcaD transcriptional start site. Within this region, we defined a PcaQ binding site with dyad symmetry that is required for regulation of pcaD expression in vivo and for binding of PcaQ in vitro. We also demonstrated that PcaQ participates in negative autoregulation by monitoring expression of pcaQ via a transcriptional fusion to lacZ. Although pcaQ homologues are present in many alpha-proteobacteria, this work describes the first reported purification of this regulator, as well as characterization of its binding site, which is conserved in Agrobacterium tumefaciens, Rhizobium leguminosarum, Rhizobium etli, and Mesorhizobium loti.}, }
@article {pmid18047211, year = {2007}, author = {Mattila, JT and Burkhardt, NY and Hutcheson, HJ and Munderloh, UG and Kurtti, TJ}, title = {Isolation of cell lines and a rickettsial endosymbiont from the soft tick Carios capensis (Acari: Argasidae: Ornithodorinae).}, journal = {Journal of medical entomology}, volume = {44}, number = {6}, pages = {1091-1101}, doi = {10.1603/0022-2585(2007)44[1091:ioclaa]2.0.co;2}, pmid = {18047211}, issn = {0022-2585}, support = {5R01 AI049424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Argasidae/genetics/*microbiology ; Cell Line ; Ovum ; Phylogeny ; Rickettsia/*isolation &amp; purification ; }, abstract = {Soft ticks are medically important ectoparasites of birds and mammals that are found throughout the world. This report describes isolation and partial characterization of two embryonic cell lines, CCE2 and CCE3, from the seabird soft tick Carios capensis (Neumann). Sequencing of the mitochondrial 16S rRNA gene and karyology confirmed the lines were derived from C. capensis. CCE3 cells were diploid with a modal chromosome number of 20. The population doubling time for cell lines CCE2 and 3 in passage 40 was 6-9 d. A rickettsial endosymbiont, RCCE3, was co-isolated along with line CCE3. Nucleotide sequences of polymerase chain reaction (PCR) products generated using primers specific for rickettsial 17-kDa antigen, outer membrane protein (omp) A, ompB, and citrate synthase genes along with phylogenetic analyses demonstrated that RCCE3 is a previously uncultured endosymbiont. The rickettsia was identified as a symbiont of C. capensis, closely related to rickettsiae previously detected by PCR in C. capensis, Ornithodoros moubata (Murray) and Hemaphysalis sulcata Canestrini &amp; Fanzago, a hard tick. RCCE3 caused a cytopathic effect in C. capensis host cells, and it was transferred to Ixodes scapularis Say cell line ISE6 for maintenance. The rickettsial endosymbiont was eliminated from CCE3 by treatment with oxytetracycline. Cell lines from C. capensis will be useful to researchers investigating interactions between soft ticks and microorganisms, soft tick physiology, and molecular biology. The rickettsia adds to the growing number of Rickettsia species that have been isolated in tick cell culture, and it is available for characterization.}, }
@article {pmid18045498, year = {2007}, author = {Gupta, RS and Mok, A}, title = {Phylogenomics and signature proteins for the alpha proteobacteria and its main groups.}, journal = {BMC microbiology}, volume = {7}, number = {}, pages = {106}, pmid = {18045498}, issn = {1471-2180}, mesh = {Alphaproteobacteria/*chemistry/*classification/genetics ; Amino Acid Sequence ; Bacterial Proteins/*analysis ; Evolution, Molecular ; Molecular Sequence Data ; Open Reading Frames ; *Phylogeny ; Sequence Alignment ; }, abstract = {BACKGROUND: Alpha proteobacteria are one of the largest and most extensively studied groups within bacteria. However, for these bacteria as a whole and for all of its major subgroups (viz. Rhizobiales, Rhodobacterales, Rhodospirillales, Rickettsiales, Sphingomonadales and Caulobacterales), very few or no distinctive molecular or biochemical characteristics are known.<br><br>RESULTS: We have carried out comprehensive phylogenomic analyses by means of Blastp and PSI-Blast searches on the open reading frames in the genomes of several alpha-proteobacteria (viz. Bradyrhizobium japonicum, Brucella suis, Caulobacter crescentus, Gluconobacter oxydans, Mesorhizobium loti, Nitrobacter winogradskyi, Novosphingobium aromaticivorans, Rhodobacter sphaeroides 2.4.1, Silicibacter sp. TM1040, Rhodospirillum rubrum and Wolbachia (Drosophila) endosymbiont). These studies have identified several proteins that are distinctive characteristics of all alpha-proteobacteria, as well as numerous proteins that are unique repertoires of all of its main orders (viz. Rhizobiales, Rhodobacterales, Rhodospirillales, Rickettsiales, Sphingomonadales and Caulobacterales) and many families (viz. Rickettsiaceae, Anaplasmataceae, Rhodospirillaceae, Acetobacteraceae, Bradyrhiozobiaceae, Brucellaceae and Bartonellaceae). Many other proteins that are present at different phylogenetic depths in alpha-proteobacteria provide important information regarding their evolution. The evolutionary relationships among alpha-proteobacteria as deduced from these studies are in excellent agreement with their branching pattern in the phylogenetic trees and character compatibility cliques based on concatenated sequences for many conserved proteins. These studies provide evidence that the major groups within alpha-proteobacteria have diverged in the following order: (Rickettsiales(Rhodospirillales (Sphingomonadales (Rhodobacterales (Caulobacterales-Parvularculales (Rhizobiales)))))). We also describe two conserved inserts in DNA Gyrase B and RNA polymerase beta subunit that are distinctive characteristics of the Sphingomonadales and Rhodosprilllales species, respectively. The results presented here also provide support for the grouping of Hyphomonadaceae and Parvularcula species with the Caulobacterales and the placement of Stappia aggregata with the Rhizobiaceae group.<br><br>CONCLUSION: The alpha-proteobacteria-specific proteins and indels described here provide novel and powerful means for the taxonomic, biochemical and molecular biological studies on these bacteria. Their functional studies should prove helpful in identifying novel biochemical and physiological characteristics that are unique to these bacteria.}, }
@article {pmid18043659, year = {2007}, author = {Pornwiroon, W and Kearney, MT and Husseneder, C and Foil, LD and Macaluso, KR}, title = {Comparative microbiota of Rickettsia felis-uninfected and -infected colonized cat fleas, Ctenocephalides felis.}, journal = {The ISME journal}, volume = {1}, number = {5}, pages = {394-402}, doi = {10.1038/ismej.2007.38}, pmid = {18043659}, issn = {1751-7362}, support = {AI60821/AI/NIAID NIH HHS/United States ; P20 RR0201595/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Cats ; Host-Pathogen Interactions ; Insect Vectors/*microbiology ; Rickettsia felis/*physiology ; Siphonaptera/*microbiology ; }, abstract = {Fleas serve as arthropod vectors for several emerging and re-emerging infectious disease causing agents including, Rickettsia felis. Although the prevalence of R. felis infection in colonies of fleas has been examined, the influence of the R. felis infection on flea microbiota has not been investigated. We identified three colonies of cat fleas, Ctenocephalides felis, with varying prevalence of R. felis infection (Louisiana State University (LSU), 93.8%; Professional Laboratory and Research Services Inc. (PLRS), 16.4%; Elward II (EL), 0%) and subsequently utilized polymerase chain reaction amplification, restriction fragment length polymorphism analysis and sequencing of the 1.4-kb portions of 16S rRNA genes to examine the diversity of bacteria in the flea populations. A total of 17 different bacterial 16S rRNA gene sequences were identified among the C. felis colonies. The prevalence of two Wolbachia species that were identified in each flea colony differed between colonies and R. felis-uninfected and -infected fleas. Species richness was unchanged among the R. felis-uninfected (LSU, PLRS and EL colonies) and -infected (LSU and PLRS colonies) fleas; however, between R. felis-uninfected and -infected fleas within both the LSU and PLRS colonies, R. felis-uninfected fleas have greater species richness. Diversity indices did not identify a difference in diversity between any of the flea samples. The interaction of endosymbionts within arthropods can widely impact the dissemination of vertically transmitted pathogenic bacteria; and the reciprocal may be true. These results suggest that carriage of R. felis has an impact on the richness of flea microbiota.}, }
@article {pmid18027391, year = {2007}, author = {Bhattacharya, D and Archibald, JM and Weber, AP and Reyes-Prieto, A}, title = {How do endosymbionts become organelles? Understanding early events in plastid evolution.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {29}, number = {12}, pages = {1239-1246}, doi = {10.1002/bies.20671}, pmid = {18027391}, issn = {0265-9247}, mesh = {*Biological Evolution ; Models, Biological ; Plant Proteins/chemistry ; Plastids/*physiology ; Protein Transport ; *Symbiosis ; }, abstract = {What factors drove the transformation of the cyanobacterial progenitor of plastids (e.g. chloroplasts) from endosymbiont to bona fide organelle? This question lies at the heart of organelle genesis because, whereas intracellular endosymbionts are widespread in both unicellular and multicellular eukaryotes (e.g. rhizobial bacteria, Chlorella cells in ciliates, Buchnera in aphids), only two canonical eukaryotic organelles of endosymbiotic origin are recognized, the plastids of algae and plants and the mitochondrion. Emerging data on (1) the discovery of non-canonical plastid protein targeting, (2) the recent origin of a cyanobacterial-derived organelle in the filose amoeba Paulinella chromatophora, and (3) the extraordinarily reduced genomes of psyllid bacterial endosymbionts begin to blur the distinction between endosymbiont and organelle. Here we discuss the use of these terms in light of new data in order to highlight the unique aspects of plastids and mitochondria and underscore their central role in eukaryotic evolution.}, }
@article {pmid18001684, year = {2007}, author = {Corich, V and Giacomini, A and Vendramin, E and Vian, P and Carlot, M and Concheri, G and Polone, E and Casella, S and Nuti, MP and Squartini, A}, title = {Long term evaluation of field-released genetically modified rhizobia.}, journal = {Environmental biosafety research}, volume = {6}, number = {3}, pages = {167-181}, doi = {10.1051/ebr:2007006}, pmid = {18001684}, issn = {1635-7922}, mesh = {Agriculture ; Colony Count, Microbial ; DNA, Bacterial/analysis ; Environment ; *Gene Flow ; Italy ; Organisms, Genetically Modified ; Peas/*microbiology ; Rhizobium leguminosarum/*genetics/growth &amp; development/*isolation &amp; purification ; Soil/analysis ; Soil Microbiology ; Time ; Vicia faba/*microbiology ; }, abstract = {This is the report of the first open field release of genetically modified microorganisms (GMMs) in Italy. It covers ten years of monitoring, and follows in-field GMM dynamics from strain release to disappearance below detection limits, as well as assessment of impact on resident microorganisms. The bacteria released belong to the nitrogen fixing legume endosymbiont Rhizobium leguminosarum bv. viciae, and were engineered with non-agronomically-proficient traits, in order to assess their behavior and fate without GMM-specific positive feedback from the plant. A DNA cassette containing mercury resistance and ss-galactosidase genes was introduced in either plasmid-borne or chromosomally integrated versions, in order to test the resulting strain stability. A synthetic promoter was used to drive the lacZ gene, conferring high catabolic activity to the GMM. Two different wild-type Rhizobium backgrounds were tested, comparing a non-indigenous vs. an indigenous, highly competitive strain. The latter had much greater persistence, since it was able to survive and establish at technically detectable levels for over four years after release. Selection factors, such as reiterated presence of the plant host, or lactose substrate supply, enhanced long-term survival to different extents. The lactose treatment showed that even a single trophic supplementation can surpass the benefits of symbiotic interaction for a period of several years. Concerning impact, the GMMs did not alter substantially the other soil community general microbiota. However, there were some significant differences in microbiota as a consequence of the Rhizobium inoculation. This effect was observed with either the WT or GMM, and was more evident in the release of the indigenous Rhizobium. Moreover, as the indigenous GMM had its parental, dominant wild-type in the same soil, it was possible to evaluate to what extent the GMM version could result in parent displacement ("self-impact"), and how much the two rhizobia would additively contribute to nodulation.}, }
@article {pmid17990528, year = {2007}, author = {Panteleev, DIu and Goriacheva, II and Andrianov, BV and Reznik, NL and Lazebnyĭ, OE and Kulikov, AM}, title = {[The endosymbiotic bacterium Wolbachia enhances the nonspecific resistance to insect pathogens and alters behavior of Drosophila melanogaster].}, journal = {Genetika}, volume = {43}, number = {9}, pages = {1277-1280}, pmid = {17990528}, issn = {0016-6758}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Beauveria/physiology ; Drosophila melanogaster/microbiology/*physiology ; Feeding Behavior ; Female ; Male ; Oviposition ; Sexual Behavior, Animal ; Symbiosis ; Tetracycline/*pharmacology ; Wolbachia/drug effects/*physiology ; }, abstract = {To determine biologically important effects of the cytoplasmic endosymbiont Wolbachia, two substrains of the same Drosophila melanogaster strain have been studied, one of them infected with Wolbachia and the other treated with tetracycline to eliminate the bacterium. Female D. melanogaster infected with Wolbachia are more resistant to the fungus Bauveria bassiana (an insect pathogen) than uninfected females; infected females also exhibited changes in oviposition substrate preference. Males infected with the bacterium are more competitive than uninfected males. The possible role of Wolbachia in the formation of alternative ecological strategies of D. melanogaster is discussed.}, }
@article {pmid17983575, year = {2007}, author = {Bordenstein, SR}, title = {Evolutionary genomics: transdomain gene transfers.}, journal = {Current biology : CB}, volume = {17}, number = {21}, pages = {R935-6}, doi = {10.1016/j.cub.2007.09.022}, pmid = {17983575}, issn = {0960-9822}, mesh = {Animals ; Arthropods/*genetics/*microbiology ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Genomics ; Nematoda/*genetics/*microbiology ; Wolbachia/*genetics ; }, abstract = {Biologists have until now conceded that bacterial gene transfer to multicellular animals is relatively uncommon in Nature. A new study showing promiscuous insertions of bacterial endosymbiont genes into invertebrate genomes ushers in a shift in this paradigm.}, }
@article {pmid17983265, year = {2007}, author = {Gabaldón, T and Huynen, MA}, title = {From endosymbiont to host-controlled organelle: the hijacking of mitochondrial protein synthesis and metabolism.}, journal = {PLoS computational biology}, volume = {3}, number = {11}, pages = {e219}, pmid = {17983265}, issn = {1553-7358}, mesh = {Biological Evolution ; Computer Simulation ; DNA Mutational Analysis/methods ; *Evolution, Molecular ; Fungal Proteins/*physiology ; Genetic Variation/genetics ; Humans ; Mitochondria/*physiology ; Mitochondrial Proteins/*physiology ; *Models, Genetic ; Organelles/physiology ; Protein Biosynthesis/*genetics ; Symbiosis/*genetics ; }, abstract = {Mitochondria are eukaryotic organelles that originated from the endosymbiosis of an alpha-proteobacterium. To gain insight into the evolution of the mitochondrial proteome as it proceeded through the transition from a free-living cell to a specialized organelle, we compared a reconstructed ancestral proteome of the mitochondrion with the proteomes of alpha-proteobacteria as well as with the mitochondrial proteomes in yeast and man. Overall, there has been a large turnover of the mitochondrial proteome during the evolution of mitochondria. Early in the evolution of the mitochondrion, proteins involved in cell envelope synthesis have virtually disappeared, whereas proteins involved in replication, transcription, cell division, transport, regulation, and signal transduction have been replaced by eukaryotic proteins. More than half of what remains from the mitochondrial ancestor in modern mitochondria corresponds to translation, including post-translational modifications, and to metabolic pathways that are directly, or indirectly, involved in energy conversion. Altogether, the results indicate that the eukaryotic host has hijacked the proto-mitochondrion, taking control of its protein synthesis and metabolism.}, }
@article {pmid17981967, year = {2008}, author = {Plague, GR and Dunbar, HE and Tran, PL and Moran, NA}, title = {Extensive proliferation of transposable elements in heritable bacterial symbionts.}, journal = {Journal of bacteriology}, volume = {190}, number = {2}, pages = {777-779}, pmid = {17981967}, issn = {1098-5530}, support = {K12 GM000708/GM/NIGMS NIH HHS/United States ; 1 K12 GM00708/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics ; *DNA Transposable Elements ; DNA, Bacterial/chemistry/genetics ; Molecular Sequence Data ; Sequence Analysis, DNA ; Weevils/*microbiology ; }, abstract = {We found that insertion sequence (IS) elements are unusually abundant in the relatively recently evolved bacterial endosymbionts of maize weevils. Because multicopy elements can facilitate genomic recombination and deletion, this IS expansion may represent an early stage in the genomic reduction that is common in most ancient endosymbionts.}, }
@article {pmid17978222, year = {2007}, author = {Partida-Martinez, LP and Groth, I and Schmitt, I and Richter, W and Roth, M and Hertweck, C}, title = {Burkholderia rhizoxinica sp. nov. and Burkholderia endofungorum sp. nov., bacterial endosymbionts of the plant-pathogenic fungus Rhizopus microsporus.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {57}, number = {Pt 11}, pages = {2583-2590}, doi = {10.1099/ijs.0.64660-0}, pmid = {17978222}, issn = {1466-5026}, mesh = {Bacterial Typing Techniques ; Burkholderia/chemistry/*classification/genetics/*growth &amp; development ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Fatty Acids/analysis ; Freeze Fracturing ; Genes, rRNA ; Microscopy, Electron ; Molecular Sequence Data ; Nucleic Acid Hybridization ; Oryza/microbiology ; Phylogeny ; Plant Diseases/*microbiology ; RNA, Ribosomal, 16S/genetics ; *Rhizopus/growth &amp; development/pathogenicity/ultrastructure ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {Several strains of the fungus Rhizopus microsporus harbour endosymbiotic bacteria for the production of the causal agent of rice seedling blight, rhizoxin, and the toxic cyclopeptide rhizonin. R. microsporus and isolated endobacteria were selected for freeze-fracture electron microscopy, which allowed visualization of bacterial cells within the fungal cytosol by their two parallel-running envelope membranes and by the fine structure of the lipopolysaccharide layer of the outer membrane. Two representatives of bacterial endosymbionts were chosen for phylogenetic analyses on the basis of full 16S rRNA gene sequences, which revealed that the novel fungal endosymbionts formed a monophyletic group within the genus Burkholderia. Inter-sequence similarities ranged from 98.94 to 100%, and sequence similarities to members of the Burkholderia pseudomallei group, the closest neighbours, were 96.74-97.38%. In addition, the bacterial strains were distinguished from their phylogenetic neighbours by their fatty acid profiles and other biochemical characteristics. The phylogenetic studies based on 16S rRNA gene sequence data, together with conclusive DNA-DNA reassociation experiments, strongly support the proposal that these strains represent two novel species within the genus Burkholderia, for which the names Burkholderia rhizoxinica sp. nov. (type strain, HKI 454T=DSM 19002T=CIP 109453T) and Burkholderia endofungorum sp. nov. (type strain, HKI 456T=DSM 19003T=CIP 109454T) are proposed.}, }
@article {pmid17974547, year = {2008}, author = {Basu, MK and Rogozin, IB and Deusch, O and Dagan, T and Martin, W and Koonin, EV}, title = {Evolutionary dynamics of introns in plastid-derived genes in plants: saturation nearly reached but slow intron gain continues.}, journal = {Molecular biology and evolution}, volume = {25}, number = {1}, pages = {111-119}, doi = {10.1093/molbev/msm234}, pmid = {17974547}, issn = {1537-1719}, support = {//Intramural NIH HHS/United States ; }, mesh = {DNA, Chloroplast/*genetics ; *Evolution, Molecular ; Genes, Plant/*genetics ; Introns/*genetics ; Plants/*genetics ; Plastids/*genetics ; Species Specificity ; }, abstract = {Some of the principal transitions in the evolution of eukaryotes are characterized by engulfment of prokaryotes by primitive eukaryotic cells. In particular, approximately 1.6 billion years ago, engulfment of a cyanobacterium that became the ancestor of chloroplasts and other plastids gave rise to Plantae, the major branch of eukaryotes comprised of glaucophytes, red algae, green algae, and green plants. After endosymbiosis, there was large-scale migration of genes from the endosymbiont to the nuclear genome of the host such that approximately 18% of the nuclear genes in Arabidopsis appear to be of chloroplast origin. To gain insights into the process of evolution of gene structure in these, originally, intronless genes, we compared the properties and the evolutionary dynamics of introns in genes of plastid origin and ancestral eukaryotic genes in Arabidopsis, poplar, and rice genomes. We found that intron densities in plastid-derived genes were slightly but significantly lower than those in ancestral eukaryotic genes. Although most of the introns in both categories of genes were conserved between monocots (rice) and dicots (Arabidopsis and poplar), lineage-specific intron gain was more pronounced in plastid-derived genes than in ancestral genes, whereas there was no significant difference in the intron loss rates between the 2 classes of genes. Thus, after the transfer to the nuclear genome, the plastid-derived genes have undergone a massive intron invasion that, by the time of the divergence of dicots and monocots (150-200 MYA), yielded intron densities only slightly lower than those in ancestral genes. Nevertheless, the accumulation of introns in plastid-derived genes appears not to have reached saturation and continues to this time, albeit at a low rate. The overall pattern of intron gain and loss in the plastid-derived genes is shaped by this continuing gain and the more general tendency for loss that is characteristic of the recent evolution of plant genes.}, }
@article {pmid17971224, year = {2007}, author = {Feldhaar, H and Straka, J and Krischke, M and Berthold, K and Stoll, S and Mueller, MJ and Gross, R}, title = {Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia.}, journal = {BMC biology}, volume = {5}, number = {}, pages = {48}, pmid = {17971224}, issn = {1741-7007}, mesh = {Amino Acids/analysis ; Animal Nutritional Physiological Phenomena ; Animals ; Ants/microbiology/*physiology ; DNA Fingerprinting ; DNA, Bacterial/genetics ; Enterobacteriaceae/*physiology ; Hemolymph/chemistry ; In Situ Hybridization, Fluorescence ; Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {BACKGROUND: Carpenter ants (genus Camponotus) are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine) of the amino acids essential to the host.<br><br>RESULTS: Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with brood-raising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control groups were fed with cockroaches, honey water and Bhatkar agar. Worker-groups were provided with brood collected from the queenright mother-colonies (45 eggs and 45 first instar larvae each). Brood production did not differ significantly between groups of symbiotic workers on diets with and without essential amino acids. However, aposymbiotic worker groups raised significantly less brood on a diet lacking essential amino acids. Reduced brood production by aposymbiotic workers was compensated when those groups were provided with essential amino acids in their diet. Decrease of endosymbionts due to treatment with antibiotic was monitored by qRT-PCR and FISH after the 90-day experimental period. Urease function was confirmed by feeding experiments using 15N-labelled urea. GC-MS analysis of 15N-enrichment of free amino acids in workers revealed significant labelling of the non-essential amino acids alanine, glycine, aspartic acid, and glutamic acid, as well as of the essential amino acids methionine and phenylalanine.<br><br>CONCLUSION: Our results show that endosymbiotic Blochmannia nutritionally upgrade the diet of C. floridanus hosts to provide essential amino acids, and that it may also play a role in nitrogen recycling via its functional urease. Blochmannia may confer a significant fitness advantage via nutritional upgrading by enhancing competitive ability of Camponotus with other ant species lacking such an endosymbiont. Domestication of the endosymbiont may have facilitated the evolutionary success of the genus Camponotus.}, }
@article {pmid17971083, year = {2007}, author = {del Val, C and Rivas, E and Torres-Quesada, O and Toro, N and Jiménez-Zurdo, JI}, title = {Identification of differentially expressed small non-coding RNAs in the legume endosymbiont Sinorhizobium meliloti by comparative genomics.}, journal = {Molecular microbiology}, volume = {66}, number = {5}, pages = {1080-1091}, pmid = {17971083}, issn = {0950-382X}, support = {R01 GM070538/GM/NIGMS NIH HHS/United States ; R01GM070538-02/GM/NIGMS NIH HHS/United States ; }, mesh = {Blotting, Northern ; Computational Biology/methods ; DNA, Intergenic ; Fabaceae/microbiology ; Genome, Bacterial/genetics ; Nucleic Acid Conformation ; Promoter Regions, Genetic ; RNA, Bacterial/*biosynthesis/*genetics ; RNA, Double-Stranded/genetics ; RNA, Untranslated/*biosynthesis/*genetics ; Sinorhizobium meliloti/chemistry/*genetics/physiology ; Transcription, Genetic ; }, abstract = {Bacterial small non-coding RNAs (sRNAs) are being recognized as novel widespread regulators of gene expression in response to environmental signals. Here, we present the first search for sRNA-encoding genes in the nitrogen-fixing endosymbiont Sinorhizobium meliloti, performed by a genome-wide computational analysis of its intergenic regions. Comparative sequence data from eight related alpha-proteobacteria were obtained, and the interspecies pairwise alignments were scored with the programs eQRNA and RNAz as complementary predictive tools to identify conserved and stable secondary structures corresponding to putative non-coding RNAs. Northern experiments confirmed that eight of the predicted loci, selected among the original 32 candidates as most probable sRNA genes, expressed small transcripts. This result supports the combined use of eQRNA and RNAz as a robust strategy to identify novel sRNAs in bacteria. Furthermore, seven of the transcripts accumulated differentially in free-living and symbiotic conditions. Experimental mapping of the 5'-ends of the detected transcripts revealed that their encoding genes are organized in autonomous transcription units with recognizable promoter and, in most cases, termination signatures. These findings suggest novel regulatory functions for sRNAs related to the interactions of alpha-proteobacteria with their eukaryotic hosts.}, }
@article {pmid17945218, year = {2008}, author = {d'Avila-Levy, CM and Santos, LO and Marinho, FA and Matteoli, FP and Lopes, AH and Motta, MC and Santos, AL and Branquinha, MH}, title = {Crithidia deanei: influence of parasite gp63 homologue on the interaction of endosymbiont-harboring and aposymbiotic strains with Aedes aegypti midgut.}, journal = {Experimental parasitology}, volume = {118}, number = {3}, pages = {345-353}, doi = {10.1016/j.exppara.2007.09.007}, pmid = {17945218}, issn = {0014-4894}, mesh = {Aedes/*parasitology ; Animals ; Antibodies, Protozoan/immunology ; Antigens, Protozoan/immunology/physiology ; Blotting, Western ; Cell Adhesion/physiology ; Crithidia/immunology/*physiology/ultrastructure ; Female ; Flow Cytometry ; Glycosylphosphatidylinositols/immunology/*physiology ; Host-Parasite Interactions ; Immunohistochemistry ; Intestines/parasitology ; Metalloendopeptidases/immunology/*physiology ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Protozoan Proteins/immunology/physiology ; Symbiosis/*physiology ; Type C Phospholipases/metabolism ; }, abstract = {The present study demonstrates that the endosymbiont of Crithidia deanei influences the expression of surface gp63 molecules. Ultrastructural immunocytochemical analysis shows the presence of the gp63-like protein in the protozoan flagellum and flagellar pocket, either attached to shed membranes or in a free form. This molecule is glycosylphosphatidylinositol (GPI) anchored to the plasma membrane as demonstrated by phospholipase C (PLC) treatment and cross-reacting determinant detection by immunoblotting. The gp63 molecule mediates the adhesive process of the protozoan to Aedes aegypti explanted guts, since the binding was reduced by pre-incubating the C. deanei parasites (wild and aposymbiotic strains) with anti-gp63 antibodies, PLC or PLC followed by anti-gp63 antibodies incubation. In addition, the number of wild C. deanei bound to A. aegypti explanted guts was twice as that of aposymbiotic parasites. Flow cytometry assays revealed that the reactivity of the wild strain with anti-gp63 antibodies was approximately twice as that of the aposymbiotic strain. We may conclude that higher expression of surface gp63 by the wild strain of C. deanei may positively influence this interaction, posing a prominent advantage for the endosymbiont-containing trypanosomatids.}, }
@article {pmid17933945, year = {2007}, author = {Ekborg, NA and Morrill, W and Burgoyne, AM and Li, L and Distel, DL}, title = {CelAB, a multifunctional cellulase encoded by Teredinibacter turnerae T7902T, a culturable symbiont isolated from the wood-boring marine bivalve Lyrodus pedicellatus.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {23}, pages = {7785-7788}, pmid = {17933945}, issn = {1098-5336}, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/genetics/isolation &amp; purification/*metabolism ; Binding Sites/genetics ; Bivalvia/*microbiology ; Cellulase/genetics/isolation &amp; purification/*metabolism ; Cellulose/metabolism ; Chitin/metabolism ; Gammaproteobacteria/*enzymology/genetics/growth &amp; development ; Polysaccharides/metabolism ; Protein Binding ; }, abstract = {We characterized a multifunctional cellulase (CelAB) encoded by the endosymbiont Teredinibacter turnerae T7902(T). CelAB contains two catalytic and two carbohydrate-binding domains, each separated by polyserine linker regions. CelAB binds cellulose and chitin, degrades multiple complex polysaccharides, and displays two catalytic activities, cellobiohydrolase (EC 3.2.1.91) and beta-1,4(3) endoglucanase (EC 3.2.1.4).}, }
@article {pmid17933921, year = {2007}, author = {Hansen, AK and Jeong, G and Paine, TD and Stouthamer, R}, title = {Frequency of secondary symbiont infection in an invasive psyllid relates to parasitism pressure on a geographic scale in California.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {23}, pages = {7531-7535}, pmid = {17933921}, issn = {1098-5336}, mesh = {Animals ; Bacteria/classification/genetics/*growth &amp; development ; California ; Geography ; Hemiptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Two endosymbionts, an obligate primary symbiont and a facultative secondary symbiont, are harbored within the invasive red gum (eucalyptus) lerp psyllid, Glycaspis brimblecombei, in California. An extensive survey of diversity and frequency of G. brimblecombei's secondary symbiont in multiple populations throughout the state of California was conducted using PCR detection, restriction enzymes, cloning, and sequencing. A total of 380 G. brimblecombei individuals in 19 populations were screened for secondary symbionts. Based on molecular screening results, only one type of secondary symbiont was present in G. brimblecombei populations in California. Overall, 40% of the 380 psyllids screened were infected with the secondary symbiont. Interestingly, secondary symbiont infection frequencies in G. brimblecombei populations varied dramatically from 0 to 75% and were significantly related to parasitism pressure by Psyllaphaegus bliteus, a solitary endoparasitoid of the psyllid.}, }
@article {pmid17919582, year = {2008}, author = {Lamb, TJ and Harris, A and Le Goff, L and Read, AF and Allen, JE}, title = {Litomosoides sigmodontis: vaccine-induced immune responses against Wolbachia surface protein can enhance the survival of filarial nematodes during primary infection.}, journal = {Experimental parasitology}, volume = {118}, number = {2}, pages = {285-289}, doi = {10.1016/j.exppara.2007.08.011}, pmid = {17919582}, issn = {0014-4894}, support = {G9901118/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Analysis of Variance ; Animals ; Bacterial Outer Membrane Proteins/*immunology ; Bacterial Vaccines/*immunology ; Cytokines/metabolism ; Female ; Filariasis/immunology/*parasitology ; Filarioidea/microbiology/*physiology ; Immunoglobulin G/blood ; Male ; Mice ; Mice, Inbred BALB C ; Symbiosis ; Vaccination ; Wolbachia/*immunology ; }, abstract = {Wolbachia are bacteria present within the tissues of most filarial nematodes. Filarial nematode survival is known to be affected by immune responses generated during filarial nematode infection and immune responses to Wolbachia can be found in different species harbouring filarial nematode infections, including humans. Using the rodent filarial model Litomosoides sigmodontis, we show that pre-exposure to wolbachia surface protein in a Th1 context (but not in a Th2-context) enhances worm survival on subsequent challenge. This study suggests that despite abundant evidence that pro-inflammatory reactions to the endosymbiont have detrimental effects on the both the nematode and mammalian host, they may under some circumstances be beneficial to the nematode.}, }
@article {pmid17919328, year = {2007}, author = {Tyra, HM and Linka, M and Weber, AP and Bhattacharya, D}, title = {Host origin of plastid solute transporters in the first photosynthetic eukaryotes.}, journal = {Genome biology}, volume = {8}, number = {10}, pages = {R212}, pmid = {17919328}, issn = {1474-760X}, support = {R01 ES013679/ES/NIEHS NIH HHS/United States ; R01 ES013679-01/ES/NIEHS NIH HHS/United States ; }, mesh = {Arabidopsis/*genetics/metabolism ; Bayes Theorem ; Carrier Proteins/*genetics/metabolism ; Cluster Analysis ; Cyanobacteria/*genetics/metabolism ; *Evolution, Molecular ; Likelihood Functions ; *Models, Biological ; Models, Genetic ; *Phylogeny ; Plastids/genetics/*metabolism ; *Symbiosis ; }, abstract = {BACKGROUND: It is generally accepted that a single primary endosymbiosis in the Plantae (red, green (including land plants), and glaucophyte algae) common ancestor gave rise to the ancestral photosynthetic organelle (plastid). Plastid establishment necessitated many steps, including the transfer and activation of endosymbiont genes that were relocated to the nuclear genome of the 'host' followed by import of the encoded proteins into the organelle. These innovations are, however, highly complex and could not have driven the initial formation of the endosymbiosis. We postulate that the re-targeting of existing host solute transporters to the plastid fore-runner was critical for the early success of the primary endosymbiosis, allowing the host to harvest endosymbiont primary production.<br><br>RESULTS: We tested this model of transporter evolution by conducting a comprehensive analysis of the plastid permeome in Arabidopsis thaliana. Of 137 well-annotated transporter proteins that were initially considered, 83 that are broadly distributed in Plantae were submitted to phylogenetic analysis. Consistent with our hypothesis, we find that 58% of Arabidopsis transporters, including all carbohydrate transporters, are of host origin, whereas only 12% arose from the cyanobacterial endosymbiont. Four transporter genes are derived from a Chlamydia-like source, suggesting that establishment of the primary plastid likely involved contributions from at least two prokaryotic sources.<br><br>CONCLUSION: Our results indicate that the existing plastid solute transport system shared by Plantae is derived primarily from host genes. Important contributions also came from the cyanobacterial endosymbiont and Chlamydia-like bacteria likely co-resident in the first algae.}, }
@article {pmid17915272, year = {2008}, author = {Engelstädter, J and Telschow, A and Yamamura, N}, title = {Coexistence of cytoplasmic incompatibility and male-killing-inducing endosymbionts, and their impact on host gene flow.}, journal = {Theoretical population biology}, volume = {73}, number = {1}, pages = {125-133}, doi = {10.1016/j.tpb.2007.08.004}, pmid = {17915272}, issn = {0040-5809}, mesh = {Animal Migration ; Animals ; Butterflies/*parasitology ; Cytoplasm/*genetics ; Gene Flow/*genetics ; Male ; Models, Statistical ; Sex Ratio ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Male-killing (MK) and cytoplasmic incompatibility (CI) inducing bacteria are among the most common endosymbionts of arthropods. Previous theoretical research has demonstrated that these two types of endosymbionts cannot stably coexist within a single unstructured host population if no doubly infected host individuals occur. Here, we analyse a model of two host subpopulations connected by migration. We demonstrate that coexistence of MK- and CI-inducing endosymbionts is possible if migration rates are sufficiently low. In particular, our results suggest that for coexistence to be possible, migration rates into the subpopulation infected predominantly with MK-inducing endosymbionts must be considerably low, while migration rates from the MK- to the CI-infected subpopulation can be very high. We also analyse how the presence of MK- and CI-inducing endosymbionts affects host gene flow between the two subpopulations. Employing the concept of the 'effective migration rate', we demonstrate that compared with an uninfected subdivided population, gene flow is increased towards the MK-infected island, but decreased towards the CI-infected island. We discuss our results with respect to the butterfly Hypolimnas bolina, in which infection polymorphism of CI- and MK-inducing Wolbachia has been reported across South-Pacific island populations.}, }
@article {pmid17912611, year = {2008}, author = {Bogorad, L}, title = {Evolution of early eukaryotic cells: genomes, proteomes, and compartments.}, journal = {Photosynthesis research}, volume = {95}, number = {1}, pages = {11-21}, pmid = {17912611}, issn = {0166-8595}, mesh = {Animals ; *Biological Evolution ; *Cell Compartmentation ; Eukaryotic Cells/*cytology/*metabolism ; Genome/*genetics ; Mitochondria/metabolism ; Proteome/*metabolism ; }, abstract = {Eukaryotes arose from an endosymbiotic association of an alpha-proteobacterium-like organism (the ancestor of mitochondria) with a host cell (lacking mitochondria or plastids). Plants arose by the addition of a cyanobacterium-like endosymbiont (the ancestor of plastids) to the two-member association. Each member of the association brought a unique internal environment and a unique genome. Analyses of recently acquired genomic sequences with newly developed algorithms have revealed (a) that the number of endosymbiont genes that remain in eukaryotic cells-principally in the nucleus-is surprisingly large, (b) that protein products of a large number of genes (or their descendents) that entered the association in the genome of the host are now directed to an organelle derived from an endosymbiont, and (c) that protein products of genes traceable to endosymbiont genomes are directed to the nucleo-cytoplasmic compartment. Consideration of these remarkable findings has led to the present suggestion that contemporary eukaryotic cells evolved through continual chance relocation and testing of genes as well as combinations of gene products and biochemical processes in each unique cell compartment derived from a member of the eukaryotic association. Most of these events occurred during about 300 million years, or so, before contemporary forms of eukaryotic cells appear in the fossil record; they continue today.}, }
@article {pmid17910686, year = {2007}, author = {Caraguel, CG and O'Kelly, CJ and Legendre, P and Frasca, S and Gast, RJ and Després, BM and Cawthorn, RJ and Greenwood, SJ}, title = {Microheterogeneity and coevolution: an examination of rDNA sequence characteristics in Neoparamoeba pemaquidensis and its prokinetoplastid endosymbiont.}, journal = {The Journal of eukaryotic microbiology}, volume = {54}, number = {5}, pages = {418-426}, doi = {10.1111/j.1550-7408.2007.00281.x}, pmid = {17910686}, issn = {1066-5234}, mesh = {Animals ; DNA, Ribosomal/*genetics ; DNA, Ribosomal Spacer/genetics ; Evolution, Molecular ; Genetic Variation ; Lobosea/classification/*genetics ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 5.8S/genetics ; Sequence Analysis, DNA ; }, abstract = {Neoparamoeba pemaquidensis, the etiological agent of amoebic gill disease, has shown surprising sequence variability among different copies of the 18S ribosomal RNA gene within an isolate. This intra-genomic microheterogeneity was confirmed and extended to an analysis of the internal transcribed spacer (ITS) region. High levels of intra-genomic nucleotide diversity (Pi=0.0201-0.0313) were found among sequenced ITS regions from individual host amoeba isolates. In contrast, the ITS region of its endosymbiont revealed significantly lower levels of intra-genomic nucleotide diversity (Pi=0.0028-0.0056) compared with the host N. pemaquidensis. Phylogenetic and ParaFit coevolution analyses involving N. pemaquidensis isolates and their respective endosymbionts confirmed a significant coevolutionary relationship between the two protists. The observation of non-shared microheterogeneity and coevolution emphasizes the complexity of the interactions between N. pemaquidensis and its obligate endosymbiont.}, }
@article {pmid17910684, year = {2007}, author = {Silver, TD and Koike, S and Yabuki, A and Kofuji, R and Archibald, JM and Ishida, K}, title = {Phylogeny and nucleomorph karyotype diversity of chlorarachniophyte algae.}, journal = {The Journal of eukaryotic microbiology}, volume = {54}, number = {5}, pages = {403-410}, doi = {10.1111/j.1550-7408.2007.00279.x}, pmid = {17910684}, issn = {1066-5234}, mesh = {Electrophoresis, Gel, Pulsed-Field ; Eukaryota/classification/*genetics ; Genetic Variation ; Karyotyping ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; }, abstract = {Chlorarachniophytes are flagellated and/or reticulopod-forming marine algae with chlorophyll a- and b-containing plastids of secondary endosymbiotic origin. They are one of only two algal groups known to possess a "nucleomorph" (i.e. the remnant nucleus of the eukaryotic endosymbiont that donated the plastid). Apart from the recently sequenced nucleomorph genome of Bigelowiella natans, little is known about the size, structure, and composition of chlorarachniophyte nucleomorph genomes. Toward the goal of better understanding nucleomorph genome diversity, as well as establishing a phylogenetic framework with which to interpret variation in chlorarachniophyte morphology, ultrastructure, and life cycle, we are studying a wide range of chlorarachniophyte strains from public culture collections and natural habitats. We have obtained 22 new chlorarachniophyte nuclear and nucleomorph 18S rRNA gene (18S rDNA) sequences and nucleomorph genome size estimates for 14 different strains. Consistent with previous studies, all of the chlorarachniophytes examined appear to possess three nucleomorph chromosomes. However, our results suggest considerable variation in nucleomorph genome size and structure, with individual chromosome sizes ranging from approximately 90 to approximately 210 kbp, and total genome sizes between approximately 330 kbp in Lotharella amoebiformis and approximately 610 kbp in unidentified chlorarachniophyte strain CCMP622. The significance of these phylogenetic and nucleomorph karyotype data is discussed.}, }
@article {pmid17908294, year = {2007}, author = {Tamames, J and Gil, R and Latorre, A and Peretó, J and Silva, FJ and Moya, A}, title = {The frontier between cell and organelle: genome analysis of Candidatus Carsonella ruddii.}, journal = {BMC evolutionary biology}, volume = {7}, number = {}, pages = {181}, pmid = {17908294}, issn = {1471-2148}, mesh = {Animals ; DNA, Bacterial ; Gammaproteobacteria/*genetics ; Genes, Bacterial ; Genes, rRNA ; *Genome, Bacterial ; Hemiptera/microbiology ; Open Reading Frames ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {BACKGROUND: Bacterial symbioses are widespread among insects. The early establishment of such symbiotic associations has probably been one of the key factors for the evolutionary success of insects, since it may have allowed access to novel ecological niches and to new imbalanced food resources, such as plant sap or blood. Several genomes of bacterial endosymbionts of different insect species have been recently sequenced, and their biology has been extensively studied. Recently, the complete genome sequence of Candidatus Carsonella ruddii, considered the primary endosymbiont of the psyllid Pachpsylla venusta, has been published. This genome consists of a circular chromosome of 159,662 bp and has been proposed as the smallest bacterial endosymbiont genome known to date.<br><br>RESULTS: The detailed analysis of the gene content of C. ruddii shows that the extensive degradation of the genome is not compatible with its consideration as a mutualistic endosymbiont and, even more, as a living organism. The ability to perform most essential functions for a cell to be considered alive is heavily impaired by the lack of genes involved in DNA replication, transcription and translation. Furthermore, the shortening of genes causes, in some cases, the loss of essential domains and functional residues needed to fulfill such vital functions. In addition, at least half of the pathways towards the biosynthesis of essential amino acids, its proposed symbiotic function, are completely or partially lost.<br><br>CONCLUSION: We propose that this strain of C. ruddii can be viewed as a further step towards the degeneration of the former primary endosymbiont and its transformation in a subcellular new entity between living cells and organelles. Although the transition of genes from C. ruddii to the host nucleus has been proposed, the amount of genes that should have been transferred to the germinal line of the insect would be so big that it would be more plausible to consider the implication of the mitochondrial machinery encoded in the insect nucleus. Furthermore, since most genes for the biosynthesis of essential amino acids have also been lost, it is likely that the host depends on another yet unidentified symbiont to complement its deficient diet.}, }
@article {pmid17899809, year = {2007}, author = {Ilinskiĭ, IuIu and Zakharov, IK}, title = {[The endosymbiont Wolbachia in Eurasian populations of Drosophila melanogaster].}, journal = {Genetika}, volume = {43}, number = {7}, pages = {905-915}, pmid = {17899809}, issn = {0016-6758}, mesh = {Animals ; Asia, Central ; Drosophila melanogaster/*microbiology ; Europe, Eastern ; Genetics, Population ; Genotype ; Transcaucasia ; Wolbachia/*genetics/isolation &amp; purification/physiology ; }, abstract = {The endosymbiotic [alpha]-proteobacteria Wolbachia is widely spread among arthropods and Filariidae nematodes. This bacterium is transmitted vertically via a transovarian route. Wolbachia is a cause of several reproductive abnormalities in the host species. We analyzed the isofemale lines created using flies collected from Drosophila melanogaster natural populations for infection with the endosymbiont Wolbachia. Wolbachia were genotyped according to five variable markers: the presence of insertion sequence IS5 in two loci, the copy number of two minisatellite repeats, and an inversion. Overall, 665 isofemale lines isolated from the populations of D. melanogaster from Ukraine, Belarus, Moldova, Caucasus, Central Asia, Ural, Udmurtia, Altai, West and East Siberia, and Far East in 1974 through 2005 were used in the work. The samples from Ukrainian, Altaian, and Middle Asian populations were largest. The infection rate of D. melanogaster populations from Middle Asia, Altaian, and Eastern Europe (Ukraine, Moldavia, and Belarus) with Wolbachia amounted to 64, 56, and 39%, respectively. The D. melanogaster population from the Caucasus displayed heterogeneity in the genotypes of this cytoplasmic infection. The Wolbachia genotype wMel, detected in all the populations studied, was the most abundant. The genotype wMelCS2 was always present in the populations from Middle Asia and Altai and was among the rare variants in the D. melanogaster populations from the Eastern Europe. Single instances of the Wolbachia genotype wMelCS occurred in a few flies from the Central Asian and Altai populations, but was not found this genotype in the other regions.}, }
@article {pmid17892581, year = {2007}, author = {Imanian, B and Keeling, PJ}, title = {The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum retain functionally overlapping mitochondria from two evolutionarily distinct lineages.}, journal = {BMC evolutionary biology}, volume = {7}, number = {}, pages = {172}, pmid = {17892581}, issn = {1471-2148}, mesh = {Animals ; DNA Primers ; DNA, Complementary ; DNA, Mitochondrial/*genetics ; DNA, Protozoan/*genetics ; Dinoflagellida/classification/enzymology/*genetics/ultrastructure ; Electron Transport Complex IV/genetics ; *Genome, Mitochondrial ; Likelihood Functions ; Mitochondria/*ultrastructure ; Phylogeny ; RNA, Protozoan ; Sequence Analysis, DNA ; Symbiosis ; Transcription, Genetic ; }, abstract = {BACKGROUND: The dinoflagellates Durinskia baltica and Kryptoperidinium foliaceum are distinguished by the presence of a tertiary plastid derived from a diatom endosymbiont. The diatom is fully integrated with the host cell cycle and is so altered in structure as to be difficult to recognize it as a diatom, and yet it retains a number of features normally lost in tertiary and secondary endosymbionts, most notably mitochondria. The dinoflagellate host is also reported to retain mitochondrion-like structures, making these cells unique in retaining two evolutionarily distinct mitochondria. This redundancy raises the question of whether the organelles share any functions in common or have distributed functions between them.<br><br>RESULTS: We show that both host and endosymbiont mitochondrial genomes encode genes for electron transport proteins. We have characterized cytochrome c oxidase 1 (cox1), cytochrome oxidase 2 (cox2), cytochrome oxidase 3 (cox3), cytochrome b (cob), and large subunit of ribosomal RNA (LSUrRNA) of endosymbiont mitochondrial ancestry, and cox1 and cob of host mitochondrial ancestry. We show that all genes are transcribed and that those ascribed to the host mitochondrial genome are extensively edited at the RNA level, as expected for a dinoflagellate mitochondrion-encoded gene. We also found evidence for extensive recombination in the host mitochondrial genes and that recombination products are also transcribed, as expected for a dinoflagellate.<br><br>CONCLUSION: Durinskia baltica and K. foliaceum retain two mitochondria from evolutionarily distinct lineages, and the functions of these organelles are at least partially overlapping, since both express genes for proteins in electron transport.}, }
@article {pmid17887971, year = {2007}, author = {Hayashi, TI and Marshall, JL and Gavrilets, S}, title = {The dynamics of sexual conflict over mating rate with endosymbiont infection that affects reproductive phenotypes.}, journal = {Journal of evolutionary biology}, volume = {20}, number = {6}, pages = {2154-2164}, doi = {10.1111/j.1420-9101.2007.01429.x}, pmid = {17887971}, issn = {1010-061X}, support = {GM56693/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Female ; Male ; Orthoptera/genetics/*microbiology/*physiology ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Maternally inherited endosymbionts have been implicated as significant drivers of sexual conflict within their hosts, typically through sex-ratio manipulation. Empirical studies show that some of these endosymbionts have the potential to influence sexual conflict not by sex-ratio distortion, but by altering reproductive traits within their hosts. Research has already shown that reproductive traits involved in mating/fertilization process are integral 'players' in sexual conflict, thus suggesting the novel hypothesis that endosymbiont-induced changes in reproductive phenotypes can impact the dynamics of sexual conflict. Here, we use a standard quantitative genetic approach to model the effects of endosymbiont-induced changes in a female reproductive trait on the dynamics of sexual conflict over mating/fertilization rate. Our model shows that an endosymbiont-induced alteration of a host female reproductive trait that affects mating rate can maintain the endosymbiont infection within the host population, and does so in the absence of sex-ratio distortion and cytoplasmic incompatibility.}, }
@article {pmid17885136, year = {2007}, author = {Ghedin, E and Wang, S and Spiro, D and Caler, E and Zhao, Q and Crabtree, J and Allen, JE and Delcher, AL and Guiliano, DB and Miranda-Saavedra, D and Angiuoli, SV and Creasy, T and Amedeo, P and Haas, B and El-Sayed, NM and Wortman, JR and Feldblyum, T and Tallon, L and Schatz, M and Shumway, M and Koo, H and Salzberg, SL and Schobel, S and Pertea, M and Pop, M and White, O and Barton, GJ and Carlow, CK and Crawford, MJ and Daub, J and Dimmic, MW and Estes, CF and Foster, JM and Ganatra, M and Gregory, WF and Johnson, NM and Jin, J and Komuniecki, R and Korf, I and Kumar, S and Laney, S and Li, BW and Li, W and Lindblom, TH and Lustigman, S and Ma, D and Maina, CV and Martin, DM and McCarter, JP and McReynolds, L and Mitreva, M and Nutman, TB and Parkinson, J and Peregrín-Alvarez, JM and Poole, C and Ren, Q and Saunders, L and Sluder, AE and Smith, K and Stanke, M and Unnasch, TR and Ware, J and Wei, AD and Weil, G and Williams, DJ and Zhang, Y and Williams, SA and Fraser-Liggett, C and Slatko, B and Blaxter, ML and Scott, AL}, title = {Draft genome of the filarial nematode parasite Brugia malayi.}, journal = {Science (New York, N.Y.)}, volume = {317}, number = {5845}, pages = {1756-1760}, pmid = {17885136}, issn = {1095-9203}, support = {R15 ES013128/ES/NIEHS NIH HHS/United States ; R01 LM006845-08/LM/NLM NIH HHS/United States ; R01 LM007938/LM/NLM NIH HHS/United States ; R01 AI048562-09/AI/NIAID NIH HHS/United States ; R01 LM006845/LM/NLM NIH HHS/United States ; R15 ES013128-01/ES/NIEHS NIH HHS/United States ; U01-AI50903/AI/NIAID NIH HHS/United States ; R01 LM007938-04/LM/NLM NIH HHS/United States ; U01 AI048828/AI/NIAID NIH HHS/United States ; R01 AI048562/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/*genetics/physiology ; Caenorhabditis/genetics ; Drosophila melanogaster/genetics ; Drug Resistance/genetics ; Filariasis/parasitology ; *Genome, Helminth ; Humans ; Molecular Sequence Data ; }, abstract = {Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design.}, }
@article {pmid17879233, year = {2007}, author = {Pankewitz, F and Zöllmer, A and Gräser, Y and Hilker, M}, title = {Anthraquinones as defensive compounds in eggs of Galerucini leaf beetles: biosynthesis by the beetles?.}, journal = {Archives of insect biochemistry and physiology}, volume = {66}, number = {2}, pages = {98-108}, doi = {10.1002/arch.20215}, pmid = {17879233}, issn = {0739-4462}, mesh = {Animals ; Anthraquinones/*metabolism ; Coleoptera/*metabolism/microbiology ; DNA, Bacterial/*analysis ; DNA, Fungal/*analysis ; Female ; Ovum/chemistry/*metabolism/microbiology ; }, abstract = {Eggs of leaf beetles of the tribe Galerucini, subfamily Galerucinae, contain polyketides that are unusual in insects: 1,8-dihydroxylated anthraquinones (chrysazin, chrysophanol) and anthrones (dithranol, chrysarobin) deterring predators. The host plants do not contain these compounds. In the present study, we tested the hypothesis that the beetles, but not bacterial or fungal microorganisms living as endosymbionts within the beetles, produce the anthraquinones. The tansy leaf beetle Galeruca tanaceti was used as Galerucini model organism. It was treated with antimicrobial substances to eradicate the microorganisms and inhibit the hypothesised endosymbiotic anthraquinone production. Despite treatment, female G. tanaceti laid eggs containing anthraquinones. Although broad spectrum antimicrobials were used, it cannot be excluded that the potential endosymbiotic microorganisms are resistant. Given that the hypothesised endosymbionts are transferred via the eggs from one generation to the next, bacterial or fungal DNA was expected to be present in the eggs. With the exception of Wolbachia pipientis, however, no further 16S rDNA from bacteria responsible for anthraquinone biosynthesis was detected in eggs of untreated beetles. Because Wolbachia were also found in closely related anthraquinone-free insects, we exclude these bacteria as producers of the defensive polyketides. Nor was any 18S rDNA from fungi with anthraquinone biosynthetic abilities detected. Our results indicate that anthraquinones and anthrones in eggs of Galerucini are produced by beetle enzymes and not by endosymbiotic microorganisms within the eggs.}, }
@article {pmid17827169, year = {2007}, author = {Reyes-Prieto, A and Bhattacharya, D}, title = {Phylogeny of nuclear-encoded plastid-targeted proteins supports an early divergence of glaucophytes within Plantae.}, journal = {Molecular biology and evolution}, volume = {24}, number = {11}, pages = {2358-2361}, doi = {10.1093/molbev/msm186}, pmid = {17827169}, issn = {0737-4038}, mesh = {Algal Proteins/genetics/metabolism ; Cell Nucleus/genetics/metabolism ; Chlorophyta/genetics ; Cyanophora/genetics ; Evolution, Molecular ; *Phylogeny ; Plant Proteins/genetics/metabolism ; Plants/*genetics/metabolism ; Plastids/*metabolism ; Rhodophyta/genetics ; }, abstract = {The phylogenetic position of the glaucophyte algae within the eukaryotic supergroup Plantae remains to be unambiguously established. Here, we assembled a multigene data set of conserved nuclear-encoded plastid-targeted proteins of cyanobacterial origin (i.e., through primary endosymbiotic gene transfer) from glaucophyte, red, and green (including land plants) algae to infer the branching order within this supergroup. We find strong support for the early divergence of glaucophytes within the Plantae, corroborating 2 important putatively ancestral characters shared by glaucophyte plastids and the cyanobacterial endosymbiont that gave rise to this organelle: the presence of a peptidoglycan deposition between the 2 organelle membranes and carboxysomes. Both these traits were apparently lost in the common ancestor of red and green algae after the divergence of glaucophytes.}, }
@article {pmid17826337, year = {2007}, author = {Opperdoes, FR and Michels, PA}, title = {Horizontal gene transfer in trypanosomatids.}, journal = {Trends in parasitology}, volume = {23}, number = {10}, pages = {470-476}, doi = {10.1016/j.pt.2007.08.002}, pmid = {17826337}, issn = {1471-4922}, mesh = {Animals ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Genes, Plant ; Genes, Viral ; Genome, Protozoan ; Phylogeny ; Trypanosomatina/*genetics ; }, abstract = {Trypanosomes harbour a large number of structural and biochemical peculiarities. Kinetoplast DNA, mitochondrial RNA editing, the sequestration of glycolysis inside glycosomes and unique oxidative-stress protection mechanisms (to name but a few) are found only in the members of the order Kinetoplastida. Thus, it is not surprising that they have provoked much speculation about why and how such oddities have evolved in trypanosomes. However, the true reasons for their existence within the eukaryotic world are still far from clear. Here, Fred Opperdoes and Paul Michels argue that the trypanosome-specific evolution of novel processes and organization could only have been made possible by the acquisition of a large number of foreign genes, which entered a trypanosomatid ancestor through lateral gene transfer. Many different organisms must have served as donors. Some of them were viruses, and others were bacteria, such as cyanobacterial endosymbionts and non-phototrophic bacteria.}, }
@article {pmid17767409, year = {2007}, author = {Eremeeva, ME and Oliveira, A and Moriarity, J and Robinson, JB and Tokarevich, NK and Antyukova, LP and Pyanyh, VA and Emeljanova, ON and Ignatjeva, VN and Buzinov, R and Pyankova, V and Dasch, GA}, title = {Detection and identification of bacterial agents in Ixodes persulcatus Schulze ticks from the north western region of Russia.}, journal = {Vector borne and zoonotic diseases (Larchmont, N.Y.)}, volume = {7}, number = {3}, pages = {426-436}, doi = {10.1089/vbz.2007.0112}, pmid = {17767409}, issn = {1530-3667}, mesh = {Anaplasmataceae/genetics/isolation &amp; purification ; Animals ; Arthropod Vectors/*microbiology ; Bacteria/genetics/*isolation &amp; purification ; Benzothiazoles ; Borrelia/genetics/isolation &amp; purification ; Diamines ; Ehrlichia/genetics/isolation &amp; purification ; Female ; Ixodes/*microbiology ; Male ; Molecular Sequence Data ; Organic Chemicals/analysis ; Polymerase Chain Reaction ; Prevalence ; Quinolines ; Rickettsia/genetics/isolation &amp; purification ; Russia ; }, abstract = {Ixodes persulcatus Schultze ticks are traditionally associated with transmission of Lyme disease, babesiosis, and tick-borne encephalitis. Here we compared the prevalence of infection with Borrelia burgdorferi, and rickettsial and ehrlichial agents in I. persulcatus ticks collected in different locations of the North Western administrative region of Russia. Altogether, 27.7% of ticks were infected with at least one organism, while the DNA of two or more bacteria was found in 11.8% of ticks tested. The highest average prevalence of Anaplasmataceae (20.8%) was detected in ticks from Arkhangel'sk province, while the prevalence in ticks from Novgorod province and St. Petersburg, respectively, was 7.3% and 12.2%. Only Ehrlichia muris DNA was identified by DNA sequencing. In comparison, the prevalence of B. burdorferi DNA was 16.6%, 5.8%, and 24.5% in the respective locations. The 382-bp amplicon of gltA from Candidatus Rickettsia tarasevichiae was detected in 2.75% and 1.6%, respectively, of ticks from Arkhangel'sk and Novgorod provinces, extending further west and north the area where this rickettsia is known to be present. DNA of the rickettsia-like endosymbiont Montezuma was primarily associated with female ticks, 8-28% of which were infected. Since I. persulcatus is so commonly infected with multiple agents that may cause human diseases, exposure to these ticks poses significant risk to human health in this region.}, }
@article {pmid17766458, year = {2007}, author = {Fukatsu, T and Koga, R and Smith, WA and Tanaka, K and Nikoh, N and Sasaki-Fukatsu, K and Yoshizawa, K and Dale, C and Clayton, DH}, title = {Bacterial endosymbiont of the slender pigeon louse, Columbicola columbae, allied to endosymbionts of grain weevils and tsetse flies.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {20}, pages = {6660-6668}, pmid = {17766458}, issn = {0099-2240}, mesh = {Animals ; DNA, Bacterial/analysis/isolation &amp; purification ; Female ; Gammaproteobacteria/classification/genetics/growth &amp; development ; In Situ Hybridization, Fluorescence ; Male ; Molecular Sequence Data ; Nymph/microbiology ; Phthiraptera/growth &amp; development/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Tsetse Flies/*microbiology ; Weevils/*microbiology ; }, abstract = {The current study focuses on a symbiotic bacterium found in the slender pigeon louse, Columbicola columbae (Insecta: Phthiraptera). Molecular phylogenetic analyses indicated that the symbiont belongs to the gamma subdivision of the class Proteobacteria and is allied to Sodalis glossinidius, the secondary symbiont of tsetse flies (Glossina spp.) and also to the primary symbiont of grain weevils (Sitophilus spp.). Relative-rate tests revealed that the symbiont of C. columbae exhibits accelerated molecular evolution in comparison with the tsetse fly symbiont and the weevil symbiont. Whole-mount in situ hybridization was used to localize the symbiont and determine infection dynamics during host development. In first- and second-instar nymphs, the symbionts were localized in the cytoplasm of oval bacteriocytes that formed small aggregates on both sides of the body cavity. In third-instar nymphs, the bacteriocytes migrated to the central body and were finally located in the anterior region of the lateral oviducts, forming conspicuous tissue formations called ovarial ampullae. In adult females, the symbionts were transmitted from the ovarial ampullae to developing oocytes in the ovarioles. In adult males, the bacteriocytes often disappeared without migration. A diagnostic PCR survey of insects collected from Japan, the United States, Australia, and Argentina detected 96.5% (109/113) infection, with a few uninfected male insects. This study provides the first microbial characterization of a bacteriocyte-associated symbiont from a chewing louse. Possible biological roles of the symbiont are discussed in relation to the host nutritional physiology associated with the feather-feeding lifestyle.}, }
@article {pmid17761848, year = {2007}, author = {Dunning Hotopp, JC and Clark, ME and Oliveira, DC and Foster, JM and Fischer, P and Muñoz Torres, MC and Giebel, JD and Kumar, N and Ishmael, N and Wang, S and Ingram, J and Nene, RV and Shepard, J and Tomkins, J and Richards, S and Spiro, DJ and Ghedin, E and Slatko, BE and Tettelin, H and Werren, JH}, title = {Widespread lateral gene transfer from intracellular bacteria to multicellular eukaryotes.}, journal = {Science (New York, N.Y.)}, volume = {317}, number = {5845}, pages = {1753-1756}, doi = {10.1126/science.1142490}, pmid = {17761848}, issn = {1095-9203}, mesh = {Animals ; Chromosome Mapping ; Crosses, Genetic ; DNA, Bacterial ; Drosophila/genetics/microbiology ; Female ; *Gene Transfer, Horizontal ; Genes, Bacterial ; In Situ Hybridization, Fluorescence ; Insecta/*genetics/microbiology ; Male ; Molecular Sequence Data ; Nematoda/*genetics/microbiology ; Retroelements ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {Although common among bacteria, lateral gene transfer-the movement of genes between distantly related organisms-is thought to occur only rarely between bacteria and multicellular eukaryotes. However, the presence of endosymbionts, such as Wolbachia pipientis, within some eukaryotic germlines may facilitate bacterial gene transfers to eukaryotic host genomes. We therefore examined host genomes for evidence of gene transfer events from Wolbachia bacteria to their hosts. We found and confirmed transfers into the genomes of four insect and four nematode species that range from nearly the entire Wolbachia genome (>1 megabase) to short (<500 base pairs) insertions. Potential Wolbachia-to-host transfers were also detected computationally in three additional sequenced insect genomes. We also show that some of these inserted Wolbachia genes are transcribed within eukaryotic cells lacking endosymbionts. Therefore, heritable lateral gene transfer occurs into eukaryotic hosts from their prokaryote symbionts, potentially providing a mechanism for acquisition of new genes and functions.}, }
@article {pmid17760387, year = {2007}, author = {Caraguel, CG and Donay, N and Frasca, S and O'Kelly, CJ and Cawthorn, RJ and Greenwood, SJ}, title = {Characterization of Neoparamoeba pemaquidensis strains: PCR-RFLP of the internal transcribed spacer region from the amoeba and endosymbiont.}, journal = {Diseases of aquatic organisms}, volume = {76}, number = {2}, pages = {141-149}, doi = {10.3354/dao076141}, pmid = {17760387}, issn = {0177-5103}, mesh = {Animals ; DNA Primers/chemistry ; DNA Restriction Enzymes/metabolism ; DNA, Ribosomal Spacer/*genetics ; Lobosea/*genetics/isolation &amp; purification ; Molecular Sequence Data ; Polymerase Chain Reaction/methods/*veterinary ; Polymorphism, Restriction Fragment Length ; Protozoan Infections/parasitology ; *Protozoan Infections, Animal ; Salmo salar/*parasitology ; Time Factors ; }, abstract = {Neoparamoeba pemaquidensis continues to be an ongoing problem for commercial finfish aquaculture and has also sporadically been associated with mass mortalities of commercially relevant marine invertebrates. Despite the ubiquity and importance of this amphizoic amoeba, our understanding of the biology as it applies to host range, pathogenicity, tissue tropism, and geographic distribution is severely lacking. This may stem from the inability of current diagnostic tests based on morphology, immunology, and molecular biology to differentiate strains at the subspecies level. In the present study, we developed a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method based on the internal transcribed spacer (ITS) region that can accurately differentiate amoeba strains of N. pemaquidensis. The investigation focused on the complications of the amoeba ITS microheterogeneity in the development of a subspecies marker and the use of the endosymbiont, Ichthyobodo necator related organism (IRO), ITS region as an alternative marker. The combination of host amoeba and endosymbiont ITS PCR-RFLP analyses was successfully used to correctly identify and characterize an N. pemaquidensis isolate from an outbreak of amoebic gill disease in Atlantic salmon Salmo salar from the west coast of North America (Washington State, USA).}, }
@article {pmid17722860, year = {2007}, author = {Ghosh, S and Azhahianambi, P and Yadav, MP}, title = {Upcoming and future strategies of tick control: a review.}, journal = {Journal of vector borne diseases}, volume = {44}, number = {2}, pages = {79-89}, pmid = {17722860}, issn = {0972-9062}, mesh = {Animals ; Disease Reservoirs ; Humans ; Insecticides/administration &amp; dosage ; Tick Infestations/prevention &amp; control/veterinary ; Tick-Borne Diseases/*prevention &amp; control/transmission ; Ticks/*immunology ; Vaccines/*therapeutic use ; }, abstract = {Ticks are distributed worldwide and significantly impact human and animal health. Due to severe problems associated with the continuous use of acaricides on animals, integrated tick management is recommended. Increasing public health concern over the tick-borne diseases demands the strategic control of ticks on animals that transmit diseases to human beings. Immunological control of tick vector of Kyasanur Forest Disease (KFD) on cattle and other wild reservoir hosts is one of the possible alternative strategy for reducing the transmission of KFD to man. Chemical-vaccine synergies have been demonstrated and a combination of chemical and vaccine for tick and tick-borne disease control has been identified as a sustainable option. Studies have suggested the possibility of vaccine strategies directed towards both tick control and transmission of pathogens. Besides tick vaccine, use of endosymbionts, which are essential for the survival of arthropod hosts, for the control of tick vectors will be one of the targeted areas of research in near future. India with huge natural resources of herbs and other medicinal plants, the possibilities of developing herbal acaricides is discussed. The future of research directed towards target identification is exciting because of new and emerging technologies for gene discovery and vaccine formulation.}, }
@article {pmid17720830, year = {2007}, author = {Klyachko, O and Stein, BD and Grindle, N and Clay, K and Fuqua, C}, title = {Localization and visualization of a coxiella-type symbiont within the lone star tick, Amblyomma americanum.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {20}, pages = {6584-6594}, pmid = {17720830}, issn = {0099-2240}, mesh = {Animals ; Coxiella/classification/genetics/*isolation &amp; purification/*ultrastructure ; DNA, Bacterial/analysis/isolation &amp; purification ; In Situ Hybridization, Fluorescence ; Ixodidae/anatomy &amp; histology/growth &amp; development/*microbiology ; Microscopy, Confocal ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Salivary Glands/microbiology ; *Symbiosis ; }, abstract = {A Coxiella-type microbe occurs at 100% frequency in all Amblyomma americanum ticks thus far tested. Using laboratory-reared ticks free of other microbes, we identified the Amblyomma-associated Coxiella microbe in several types of tissue and at various stages of the life cycle of A. americanum by 16S rRNA gene sequencing and diagnostic PCR. We visualized Amblyomma-associated Coxiella through the use of a diagnostic fluorescence in situ hybridization (FISH) assay supplemented with PCR-based detection, nucleic acid fluorescent staining, wide-field epifluorescence and confocal microscopy, and transmission electron microscopy (TEM). Specific fluorescent foci were observed in several tick tissues, including the midgut and the Malpighian tubules, but particularly bright signals were observed in the granular acini of salivary gland clusters and in both small and large oocytes. TEM confirmed intracellular bacterial structures in the same tissues. The presence of Amblyomma-associated Coxiella within oocytes is consistent with the vertical transmission of these endosymbionts. Further, the presence of the Amblyomma-associated Coxiella symbiont in other tissues such as salivary glands could potentially lead to interactions with horizontally acquired pathogens.}, }
@article {pmid17716833, year = {2007}, author = {Ahmadinejad, N and Dagan, T and Martin, W}, title = {Genome history in the symbiotic hybrid Euglena gracilis.}, journal = {Gene}, volume = {402}, number = {1-2}, pages = {35-39}, doi = {10.1016/j.gene.2007.07.023}, pmid = {17716833}, issn = {0378-1119}, mesh = {Animals ; Chimera/*genetics/metabolism ; DNA, Complementary/metabolism ; Euglena gracilis/*genetics/metabolism ; Evolution, Molecular ; *Genome ; Humans ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {Euglena gracilis has a chimeric gene collection in which some genes were inherited from its heterotrophic host and others were acquired from a photoautotrophic endosymbiont during secondary endosymbiosis. The evolutionary reconstruction of such a hybrid genome poses a challenge for standard phylogenetic tools that produce bifurcating trees because genome evolution by endosymbiotic gene transfer is a non tree-like process. We sequenced 2770 ESTs from E. gracilis, of which 841 have homologues in a sample of other eukaryotes. Most of these homologues are found in all of the eukaryotes in our sample, but 117 of them are specific to photoautotrophic eukaryotes. A phylogenetic tree fails to account for this observation but the distribution of homologues and a phylogenetic network clearly show the common origin of E. gracilis from both kinetoplastid and photoautotrophic ancestors.}, }
@article {pmid17714482, year = {2007}, author = {de Azevedo-Martins, AC and Frossard, ML and de Souza, W and Einicker-Lamas, M and Motta, MC}, title = {Phosphatidylcholine synthesis in Crithidia deanei: the influence of the endosymbiont.}, journal = {FEMS microbiology letters}, volume = {275}, number = {2}, pages = {229-236}, doi = {10.1111/j.1574-6968.2007.00892.x}, pmid = {17714482}, issn = {0378-1097}, mesh = {Animals ; Bacteria/*metabolism ; Cell Membrane/metabolism ; Crithidia/growth &amp; development/metabolism/*microbiology ; Culture Media ; Mitochondria/metabolism ; Phosphatidylcholines/*metabolism ; Phospholipids/metabolism ; Phosphorus Radioisotopes/metabolism ; *Symbiosis ; }, abstract = {In this study, the role of phospholipid biosynthetic pathways was investigated in the establishment of the mutualistic relationship between the trypanosomatid protozoan Crithidia deanei and its symbiotic bacterium. Although the endosymbiont displays two unit membranes, it lacks a typical Gram-negative cell wall. As in other intracellular bacteria, phosphatidylcholine is a major component of the symbiont envelope. Here, it was shown that symbiont-bearing C. deanei incorporates more than two-fold (32)Pi into phospholipids as compared with the aposymbiotic strain. The major phospholipid synthesized by both strains was phosphatidylcholine, followed by phosphatidylethanolamine and phosphatidylinositol. Cellular fractioning indicated that (32)Pi-phosphatidylcholine is the major phospholipid component of the isolated symbionts, as well as of mitochondria. Although the data indicated that isolated symbionts synthesized phospholipids independently of the trypanosomatid host, a key finding was that the isolated bacteria synthesized mostly phosphatidylethanolamine, rather than phosphatidylcholine. These results indicate that phosphatidylcholine production by the symbiont depends on metabolic exchanges with the host protozoan. Insight about the mechanisms underlying lipid biosynthesis in symbiont-bearing C. deanei might help to understand how the prokaryote/trypanosomatid relation has evolved in the establishment of symbiosis.}, }
@article {pmid17704269, year = {2007}, author = {Herlemann, DP and Geissinger, O and Brune, A}, title = {The termite group I phylum is highly diverse and widespread in the environment.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {20}, pages = {6682-6685}, pmid = {17704269}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/genetics ; Cattle/microbiology ; DNA Primers ; Databases, Genetic ; Isoptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rumen/*microbiology ; Sequence Analysis, DNA ; *Soil Microbiology ; *Symbiosis ; }, abstract = {The bacterial candidate phylum Termite Group I (TG-1) presently consists mostly of "Endomicrobia," which are endosymbionts of flagellate protists occurring exclusively in the hindguts of termites and wood-feeding cockroaches. Here, we show that public databases contain many, mostly undocumented 16S rRNA gene sequences from other habitats that are affiliated with the TG-1 phylum but are only distantly related to "Endomicrobia." Phylogenetic analysis of the expanded data set revealed several diverse and deeply branching lineages comprising clones from many different habitats. In addition, we designed specific primers to explore the diversity and environmental distribution of bacteria in the TG-1 phylum.}, }
@article {pmid17693143, year = {2007}, author = {Fauvart, M and Braeken, K and Daniels, R and Vos, K and Ndayizeye, M and Noben, JP and Robben, J and Vanderleyden, J and Michiels, J}, title = {Identification of a novel glyoxylate reductase supports phylogeny-based enzymatic substrate specificity prediction.}, journal = {Biochimica et biophysica acta}, volume = {1774}, number = {9}, pages = {1092-1098}, doi = {10.1016/j.bbapap.2007.06.009}, pmid = {17693143}, issn = {0006-3002}, mesh = {Alcohol Oxidoreductases/isolation &amp; purification/*metabolism ; Amino Acid Sequence ; Kinetics ; Molecular Sequence Data ; Phylogeny ; Rhizobium etli/enzymology ; Sequence Alignment ; Substrate Specificity ; }, abstract = {Phylogenetic analysis of the superfamily of D-2-hydroxyacid dehydrogenases identified the previously unrecognized cluster of glyoxylate/hydroxypyruvate reductases (GHPR). Based on the genome sequence of Rhizobium etli, the nodulating endosymbiont of the common bean plant, we predicted a putative 3-phosphoglycerate dehydrogenase to exhibit GHPR activity instead. The protein was overexpressed and purified. The enzyme is homodimeric under native conditions and is indeed capable of reducing both glyoxylate and hydroxypyruvate. Other substrates are phenylpyruvate and ketobutyrate. The highest activity was observed with glyoxylate and phenylpyruvate, both having approximately the same kcat/Km ratio. This kind of substrate specificity has not been reported previously for a GHPR. The optimal pH for the reduction of phenylpyruvate to phenyllactate is pH 7. These data lend support to the idea of predicting enzymatic substrate specificity based on phylogenetic clustering.}, }
@article {pmid17686026, year = {2007}, author = {Elsaied, H and Stokes, HW and Nakamura, T and Kitamura, K and Fuse, H and Maruyama, A}, title = {Novel and diverse integron integrase genes and integron-like gene cassettes are prevalent in deep-sea hydrothermal vents.}, journal = {Environmental microbiology}, volume = {9}, number = {9}, pages = {2298-2312}, doi = {10.1111/j.1462-2920.2007.01344.x}, pmid = {17686026}, issn = {1462-2912}, mesh = {Archaea/enzymology/*genetics ; Bacteria/enzymology/*genetics ; Integrases/classification/*genetics ; Integrons/*genetics ; Japan ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/classification ; Seawater/*microbiology ; Sequence Analysis, DNA ; }, abstract = {The lack of information about mobile DNA in deep-sea hydrothermal vents limits our understanding of the phylogenetic diversity of the mobile genome of bacteria in these environments. We used culture-independent techniques to explore the diversity of the integron/mobile gene cassette system in a variety of hydrothermal vent communities. Three samples, which included two different hydrothermal vent fluids and a mussel species that contained essentially monophyletic sulfur-oxidizing bacterial endosymbionts, were collected from Suiyo Seamount, Izu-Bonin, Japan, and Pika site, Mariana arc. First, using degenerate polymerase chain reaction (PCR) primers, we amplified integron integrase genes from metagenomic DNA from each sample. From vent fluids, we discovered 74 new integrase genes that were classified into 11 previously undescribed integron classes. One integrase gene was recorded in the mussel symbiont and was phylogenetically distant from those recovered from vent fluids. Second, using PCR primers targeting the gene cassette recombination site (59-be), we amplified and subsequently identified 60 diverse gene cassettes. In multicassette amplicons, a total of 13 59-be sites were identified. Most of these sites displayed features that were atypical of the features previously well conserved in this family. The Suiyo vent fluid was characterized by gene cassette open reading frames (ORFs) that had significant homologies with transferases, DNA-binding proteins and metal transporter proteins, while the majority of Pika vent fluid gene cassettes contained novel ORFs with no identifiable homologues in databases. The symbiont gene cassette ORFs were found to be matched with DNA repair proteins, methionine aminopeptidase, aminopeptidase N, O-sialoglycoprotein endopeptidase and glutamate synthase, which are proteins expected to play a role in animal/symbiont metabolism. The success of this study indicates that the integron/gene cassette system is common in deep-sea hydrothermal vents, an environment type well removed from anthropogenic disturbance.}, }
@article {pmid17684698, year = {2007}, author = {Waters, ER and Rioflorido, I}, title = {Evolutionary analysis of the small heat shock proteins in five complete algal genomes.}, journal = {Journal of molecular evolution}, volume = {65}, number = {2}, pages = {162-174}, pmid = {17684698}, issn = {0022-2844}, mesh = {Algal Proteins/*genetics ; Amino Acid Sequence ; Animals ; Chlamydomonas reinhardtii/genetics ; Chlorophyta/genetics ; Diatoms/genetics ; Eukaryota/classification/*genetics ; *Evolution, Molecular ; *Genome ; Heat-Shock Proteins, Small/*genetics ; Molecular Sequence Data ; Phylogeny ; Rhodophyta/genetics ; Sequence Alignment ; Sequence Analysis, Protein ; Species Specificity ; }, abstract = {Small heat shock proteins (sHSPs) are chaperones that are crucial in the heat shock response but also have important nonstress roles within the cell. sHSPs are found in all three domains of life (Bacteria, Archaea, and Eukarya). These proteins are particularly diverse within land plants and the evolutionary origin of the land plant sHSP families is still an open question. Here we describe the identification of 17 small sHSPs from the complete genome sequences of five diverse algae: Chlamydomonas reinhardtii, Cyanidioschyzon merolae, Ostreococcus lucimarinus, Ostreococcus tauri, and Thalassiosira pseudonana. Our analysis indicates that the number and diversity of algal sHSPs are not correlated with adaptation to extreme conditions. While all of the algal sHSPs identified are members of this large and important superfamily, none of these sHSPs are members of the diverse land plant sHSP families. The evolutionary relationships among the algal sHSPs and homologues from bacteria and other eukaryotes are consistent with the hypothesis that the land plant chloroplast and mitochondrion sHSPs did not originate from the endosymbionts of the chloroplast and mitochondria. In addition the evolutionary history of the sHSPs is very different from that of the HSP70s. Finally, our analysis of the algal sHSPs sequences in light of the known sHSP crystal structures and functional data suggests that the sHSPs possess considerable structural and functional diversity.}, }
@article {pmid17684548, year = {2007}, author = {Telschow, A and Flor, M and Kobayashi, Y and Hammerstein, P and Werren, JH}, title = {Wolbachia-induced unidirectional cytoplasmic incompatibility and speciation: mainland-island model.}, journal = {PloS one}, volume = {2}, number = {8}, pages = {e701}, pmid = {17684548}, issn = {1932-6203}, mesh = {Animals ; *Cytoplasm ; Female ; Gene Flow ; *Genetic Speciation ; Genetics, Population ; *Geography ; Host-Parasite Interactions/genetics ; Insecta/genetics/microbiology ; Male ; *Models, Genetic ; Selection, Genetic ; Sexual Behavior, Animal ; Symbiosis/genetics ; *Wolbachia/cytology/genetics ; }, abstract = {Bacteria of the genus Wolbachia are among the most common endosymbionts in the world. In many insect species these bacteria induce a sperm-egg incompatibility between the gametes of infected males and uninfected females, commonly called unidirectional cytoplasmic incompatibility (CI). It is generally believed that unidirectional CI cannot promote speciation in hosts because infection differences between populations will be unstable and subsequent gene flow will eliminate genetic differences between diverging populations. In the present study we investigate this question theoretically in a mainland-island model with migration from mainland to island. Our analysis shows that (a) the infection polymorphism is stable below a critical migration rate, (b) an (initially) uninfected "island" can better maintain divergence at a selected locus (e.g. can adapt locally) in the presence of CI, and (c) unidirectional CI selects for premating isolation in (initially) uninfected island populations if they receive migration from a Wolbachia-infected mainland. Interestingly, premating isolation is most likely to evolve if levels of incompatibility are intermediate and if either the infection causes fecundity reductions or Wolbachia transmission is incomplete. This is because under these circumstances an infection pattern with an infected mainland and a mostly uninfected island can persist in the face of comparably high migration. We present analytical results for all three findings: (a) a lower estimation of the critical migration rate in the presence of local adaptation, (b) an analytical approximation for the gene flow reduction caused by unidirectional CI, and (c) a heuristic formula describing the invasion success of mutants at a mate preference locus. These findings generally suggest that Wolbachia-induced unidirectional CI can be a factor in divergence and speciation of hosts.}, }
@article {pmid17681859, year = {2007}, author = {Kröber, T and Guerin, PM}, title = {In vitro feeding assays for hard ticks.}, journal = {Trends in parasitology}, volume = {23}, number = {9}, pages = {445-449}, doi = {10.1016/j.pt.2007.07.010}, pmid = {17681859}, issn = {1471-4922}, mesh = {Animals ; Biological Assay ; Feeding Behavior/*physiology ; *Host-Parasite Interactions ; Humans ; In Vitro Techniques ; Ixodidae/*physiology ; Models, Biological ; Tick-Borne Diseases/prevention &amp; control/*transmission ; }, abstract = {Prevention of tick bites and transmission of tick-borne pathogens requires the use of molecules that target physiological processes crucial to both tick and pathogen survival. These molecules are best tested in standardized in vitro assays. Because hard ticks require several days to feed to repletion, the development of in vitro feeding assays for these species is challenging. A standard and easily automated feeding assay has been developed for the tick Ixodes ricinus that involves feeding on blood through a membrane that mimics the elasticity of skin. The system can be adapted to feed other hard tick species in vitro. This assay permits, among others, investigations on the role of tick endosymbionts on tick survival, the identification of potential vaccine candidates and drugs, and the application of genomic tools in vitro, including RNA interference experiments.}, }
@article {pmid17674756, year = {2007}, author = {Gao, LJ and Wang, XF and Yang, HY and Gao, XZ and Lü, YC and Cui, ZJ}, title = {[Effects of a lactic acid bacteria community SFC-2 treated on rice straw].}, journal = {Huan jing ke xue= Huanjing kexue}, volume = {28}, number = {6}, pages = {1392-1396}, pmid = {17674756}, issn = {0250-3301}, mesh = {Electrophoresis, Polyacrylamide Gel ; *Fermentation ; Lactic Acid/analysis ; Lactobacillus/*metabolism ; Oryza/microbiology ; Plant Stems/*microbiology ; Refuse Disposal/*methods ; }, abstract = {Aimed to utilize rice straw and lessen the pressure of environment, the rice straw was used as the fermentation material, and a lactic acid bacteria community SFC-2 from my laboratory was inoculated into the rice straw to investigate the inoculation effects. After 30 days fermentation, the inoculated fermented straw smelt acid-fragrant, and the pH value was 3.8, which was lower than the control of 4.1. Furthermore, lactic acid concentration was more than that in the control. Especially L-lactic acid concentration was two times more than in the control, and the crude protein content was 10.16% higher than that in the control, and the crude fiber content was 3.2% lower than that in the control. From the patterns of denaturing gradient gel electrophoresis (DGGE), Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus paracasei rapidly became the advantageous species in the inoculated straws. However, Enterobacter sakazakii, Pantoea agglomerans, Enterobacter endosymbiont, Pantoea ananatis, whichwere predominate in the controls, were not detected in the inoculated straws, and the fermented quality was improved significantly.}, }
@article {pmid17673369, year = {2007}, author = {Sréter-Lancz, Z and Széll, Z and Sréter, T}, title = {Molecular genetic comparison of Onchocerca sp. infecting dogs in Europe with other spirurid nematodes including Onchocerca lienalis.}, journal = {Veterinary parasitology}, volume = {148}, number = {3-4}, pages = {365-370}, doi = {10.1016/j.vetpar.2007.06.021}, pmid = {17673369}, issn = {0304-4017}, mesh = {Animals ; Dog Diseases/microbiology/*parasitology ; Dogs ; Electron Transport Complex IV/genetics ; Europe ; Female ; Molecular Sequence Data ; NADH Dehydrogenase/genetics ; Onchocerca/classification/enzymology/*genetics/microbiology ; Onchocerciasis, Ocular/microbiology/parasitology/*veterinary ; Phylogeny ; Spirurida/enzymology/*genetics ; Wolbachia/genetics ; }, abstract = {In the past 15 years, subconjunctival onchocercosis has been reported from 63 dogs in south-western United States (Arizona, California, Utah) and Southern and Central Europe (Germany, Greece, Hungary, Portugal, Switzerland). To reveal the taxonomic status of the parasite responsible for these infections, fragments of the mitochondrial cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 5 (ND5) genes of three European strains of canine Onchocerca sp. and the 16S ribosomal RNA (16S rRNA) gene of their Wolbachia endosymbionts were sequenced and compared to the homologous sequences of other spirurid nematodes. The evolutionary divergence between COI and ND5 gene sequences of Greek, Hungarian and Portuguese strains of canine Onchocerca sp. were similar in magnitude to that seen within Thelazia callipaeda or Onchocerca lienalis. The evolutionary divergence between the sequences of canine Onchocerca sp. and other Onchocerca spp. including O. lienalis were similar or higher in magnitude to that seen between other Onchocerca spp. The results of the current and earlier phylogenetic analyses indicate that canine Onchocerca sp. separated from other Onchocerca spp. early in the evolution. Based on the similar clinical pictures, the identical morphology of nematodes and the sequence analyses of COI and ND5 genes of the worms and 16S rRNA gene of their wolbachiae, the Onchocerca worms isolated from European dogs appear to belong to the same species. The results support the earlier biological and morphological arguments that a distinct species, most likely O. lupi originally described from the subconjunctival tissues of a Caucasian wolf is responsible for canine ocular onchocercosis in Europe.}, }
@article {pmid17664430, year = {2007}, author = {Fraune, S and Bosch, TC}, title = {Long-term maintenance of species-specific bacterial microbiota in the basal metazoan Hydra.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {104}, number = {32}, pages = {13146-13151}, pmid = {17664430}, issn = {0027-8424}, mesh = {Animals ; Bacteria/*classification ; Base Sequence ; Epithelial Cells/microbiology ; Fresh Water/microbiology ; Hydra/*microbiology ; Immunity, Innate ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Restriction Fragment Length ; Species Specificity ; Symbiosis ; }, abstract = {Epithelia in animals are colonized by complex communities of microbes. Although a topic of long-standing interest, understanding the evolution of the microbial communities and their role in triggering innate immune responses has resisted analysis. Cnidaria are among the simplest animals at the tissue grade of organization. To obtain a better understanding of the microbiota associated with phylogenetically ancient epithelia, we have identified the epibiotic and endosymbiotic bacteria of two species of the cnidarian Hydra on the basis of rRNA comparisons. We analyzed individuals of Hydra oligactis and Hydra vulgaris from both laboratory cultures and the wild. We discovered that individuals from both species differ greatly in their bacterial microbiota. Although H. vulgaris polyps have a quite diverse microbiota, H. oligactis appears to be associated with only a limited number of microbes; some of them were found, unexpectedly, to be endosymbionts. Surprisingly, the microfauna showed similar characteristics in individuals of cultures maintained in the laboratory for >30 years and polyps directly isolated from the wild. The significant differences in the microbial communities between the two species and the maintenance of specific microbial communities over long periods of time strongly indicate distinct selective pressures imposed on and within the epithelium. Our analysis suggests that the Hydra epithelium actively selects and shapes its microbial community.}, }
@article {pmid17652010, year = {2007}, author = {Goggin, FL}, title = {Plant-aphid interactions: molecular and ecological perspectives.}, journal = {Current opinion in plant biology}, volume = {10}, number = {4}, pages = {399-408}, doi = {10.1016/j.pbi.2007.06.004}, pmid = {17652010}, issn = {1369-5266}, mesh = {Animal Feed ; Animals ; Ants/pathogenicity ; Aphids/*pathogenicity ; Cell Death ; Cell Wall/parasitology/physiology ; Ecosystem ; Immunity, Innate ; Plant Cells ; Plant Development ; Plant Diseases/*parasitology ; Plants/genetics/*parasitology ; }, abstract = {Many aphids are major agricultural pests because of their unparalleled reproductive capacity and their ability to manipulate host plant physiology. Aphid population growth and its impact on plant fitness are strongly influenced by interactions with other organisms, including plant pathogens, endophytes, aphid endosymbionts, predators, parasitoids, ants, and other herbivores. Numerous molecular and genomic resources have recently been developed to identify sources of aphid resistance in plants, as well as potentially novel targets for control in aphids. Moreover, the same model systems that are used to explore direct molecular interactions between plants and aphids can be utilized to study the ecological context in which they occur.}, }
@article {pmid17634867, year = {2007}, author = {Kitajima, EW and Groot, TV and Novelli, VM and Freitas-Astúa, J and Alberti, G and de Moraes, GJ}, title = {In situ observation of the Cardinium symbionts of Brevipalpus (Acari: Tenuipalpidae) by electron microscopy.}, journal = {Experimental &amp; applied acarology}, volume = {42}, number = {4}, pages = {263-271}, pmid = {17634867}, issn = {0168-8162}, mesh = {Animals ; Cytophagaceae/physiology/*ultrastructure ; Female ; Life Cycle Stages ; Microscopy, Electron, Transmission ; Mites/*microbiology/ultrastructure ; Ovum/microbiology ; Polymerase Chain Reaction ; Symbiosis/*physiology ; }, abstract = {Brevipalpus (Acari: Tenuipalpidae) mites are important pests on a variety of host plant species. The mites damage their hosts directly by feeding and some species also serve as vectors of plant viruses. Among more than 200 described Brevipalpus species, three are recognized as vectors of plant viruses: B. phoenicis, B. californicus and B. obovatus. These species occur worldwide in subtropical and tropical regions. Brevipalpus mites reproduce mostly by thelytokous parthenogenesis and this condition was attributed to a bacterial endosymbiont, recently characterized as a member of the genus Cardinium. The same symbiont infects many other arthropods and is capable of manipulating their host reproduction in various ways. Generally the presence of Cardinium is determined by molecular, PCR based, techniques. In the current work we present visual evidence for the presence of these bacteria by transmission electron microscopy as a complement of previous detection by PCR. Cardinium is easily identified by the presence of a unique array of microtubule-like structures (ML) in the cell. Symbionts have been observed in several organs and eggs from different populations of all three Brevipalpus species known as vector of plant viruses. Cardinium cells were always immersed directly within the cytoplasm of infected cells. Bacteria were observed in all females of all instars, but were absent from all males examined. Females from some Brevipalpus populations were observed to be uninfected by Cardinium. This observation confirmed previous PCR-based results that these populations were aposymbiotic. The observed distribution of the bacteria suggests that these bacteria could have other functions in the mite biology beside feminization.}, }
@article {pmid17629911, year = {2007}, author = {Aanen, DK and Ros, VI and de Fine Licht, HH and Mitchell, J and de Beer, ZW and Slippers, B and Rouland-Lefèvre, C and Boomsma, JJ}, title = {Patterns of interaction specificity of fungus-growing termites and Termitomyces symbionts in South Africa.}, journal = {BMC evolutionary biology}, volume = {7}, number = {}, pages = {115}, pmid = {17629911}, issn = {1471-2148}, mesh = {Agaricales/*genetics ; Animals ; DNA, Fungal/genetics ; DNA, Ribosomal Spacer/*genetics ; Genes, Fungal ; Genes, Insect ; Isoptera/*genetics/*microbiology ; Phylogeny ; South Africa ; Species Specificity ; *Symbiosis ; }, abstract = {BACKGROUND: Termites of the subfamily Macrotermitinae live in a mutualistic symbiosis with basidiomycete fungi of the genus Termitomyces. Here, we explored interaction specificity in fungus-growing termites using samples from 101 colonies in South-Africa and Senegal, belonging to eight species divided over three genera. Knowledge of interaction specificity is important to test the hypothesis that inhabitants (symbionts) are taxonomically less diverse than 'exhabitants' (hosts) and to test the hypothesis that transmission mode is an important determinant for interaction specificity.<br><br>RESULTS: Analysis of Molecular Variance among symbiont ITS sequences across termite hosts at three hierarchical levels showed that 47 % of the variation occurred between genera, 18 % between species, and the remaining 35 % between colonies within species. Different patterns of specificity were evident. High mutual specificity was found for the single Macrotermes species studied, as M. natalensis was associated with a single unique fungal haplotype. The three species of the genus Odontotermes showed low symbiont specificity: they were all associated with a genetically diverse set of fungal symbionts, but their fungal symbionts showed some host specificity, as none of the fungal haplotypes were shared between the studied Odontotermes species. Finally, bilaterally low specificity was found for the four tentatively recognized species of the genus Microtermes, which shared and apparently freely exchanged a common pool of divergent fungal symbionts.<br><br>CONCLUSION: Interaction specificity was high at the genus level and generally much lower at the species level. A comparison of the observed diversity among fungal symbionts with the diversity among termite hosts, indicated that the fungal symbiont does not follow the general pattern of an endosymbiont, as we found either similar diversity at both sides or higher diversity in the symbiont. Our results further challenge the hypothesis that transmission-mode is a general key-determinant of interaction specificity in fungus-growing termites.}, }
@article {pmid17626353, year = {2007}, author = {Ogino, K and Tsuneki, K and Furuya, H}, title = {The expression of tubulin and tektin genes in dicyemid mesozoans (Phylum: Dicyemida).}, journal = {The Journal of parasitology}, volume = {93}, number = {3}, pages = {608-618}, doi = {10.1645/GE-1037R.1}, pmid = {17626353}, issn = {0022-3395}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Blotting, Southern ; DNA, Complementary/chemistry ; *Gene Expression Regulation, Developmental ; In Situ Hybridization ; Invertebrates/classification/*genetics/growth &amp; development/metabolism ; Life Cycle Stages ; Microtubule Proteins/chemistry/*genetics/physiology ; Molecular Sequence Data ; Octopodiformes/*parasitology ; Phylogeny ; Tubulin/chemistry/*genetics/physiology ; }, abstract = {Dicyemid mesozoans (Phylum Dicyemida) are endoparasites (or endosymbionts) that typically are found in the renal sac of benthic cephalopod mollusks such as octopuses and cuttlefishes. Adult dicyemids likely adhere to the renal appendage of hosts via cilia of calotte peripheral cells. These cilia seem to be continuously worn away in the interaction between the dicyemids and the epidermal cells of host renal appendages. We cloned 4 cDNAs and genes, alpha-tubulin, beta-tubulin, tektin B, and tektin C, which are thought to play a key role in ciliogenesis, from Dicyema japonicum, and studied expression patterns of these genes by whole-mount in situ hybridization. We detected coexpression of these genes in the calotte peripheral cells, but not in the trunk peripheral cells. This suggests that regeneration and turnover of cilia continuously occur in the calotte. In vermiform and infusoriform embryos, we also detected coexpression patterns of these genes, which might correlate with ciliogenesis during the embryogenesis. We also predicted the secondary structure and the coiled-coil regions of dicyemid tektins.}, }
@article {pmid17621589, year = {2007}, author = {Monsen, KJ and Honchak, BM and Locke, SE and Peterson, MA}, title = {Cytonuclear disequilibrium in chrysochus hybrids is not due to patterns of mate choice.}, journal = {The Journal of heredity}, volume = {98}, number = {4}, pages = {325-330}, doi = {10.1093/jhered/esm039}, pmid = {17621589}, issn = {0022-1503}, mesh = {Animals ; Cell Nucleus/genetics ; Chimera/*genetics ; Choice Behavior/*physiology ; Coleoptera/*genetics/microbiology/physiology ; *Extrachromosomal Inheritance ; Female ; Genome, Insect ; Haplotypes ; *Linkage Disequilibrium ; Male ; *Pair Bond ; Wolbachia/genetics ; }, abstract = {We investigated patterns of cytonuclear disequilibrium between nuclear allozyme loci and partial mitochondrial COI and COII restriction fragment length polymorphism patterns within a population of hybridizing chrysomelid beetles and assessed to what degree the genotype frequencies of F1 hybrids were consistent with patterns of mate choice or endosymbiont infection. We document that in this population, > or = 50% of the heterospecific pairs at a given time are composed of Chrysochus auratus females and Chrysochus cobaltinus males, suggesting that at least half of the F1 hybrids should possess the C. auratus mitochondrial genotype. However, we found that the majority (89%) of F1 hybrids possessed C. cobaltinus mtDNA (P < 0.001). The lack of evidence for Wolbachia infection in these highly promiscuous beetles, coupled with the fact that F1 hybrids of both cross types do exist, indicates that endosymbionts are an unlikely explanation for the discrepancy between cytonuclear genotype frequencies and behavior. We argue that cytonuclear disequilibrium at this focal Chrysochus hybrid site is likely due to a strong directional bias in postmating prezygotic barriers in this system. The results presented here underscore the importance of combining both field and molecular data in studies of cytonuclear disequilibrium and point to the dangers inherent in attributing patterns of cytonuclear disequilibrium to assortative mating.}, }
@article {pmid17610830, year = {2007}, author = {Lane, CE}, title = {Bacterial endosymbionts: genome reduction in a hot spot.}, journal = {Current biology : CB}, volume = {17}, number = {13}, pages = {R508-10}, doi = {10.1016/j.cub.2007.04.035}, pmid = {17610830}, issn = {0960-9822}, mesh = {Animals ; *Biological Evolution ; Bivalvia/*microbiology ; Ecosystem ; *Genome, Bacterial ; Gills/*microbiology ; Hot Temperature ; Pacific Ocean ; Symbiosis/*genetics ; }, abstract = {Prokaryotic symbionts are common in invertebrates and play an essential metabolic role in deep-sea hydrothermal vent communities. Complete genome sequences of bacterial endosymbionts of two deep-sea clams are providing new insights into evolutionary genome reduction.}, }
@article {pmid17600460, year = {2007}, author = {Reyes-Prieto, A and Weber, AP and Bhattacharya, D}, title = {The origin and establishment of the plastid in algae and plants.}, journal = {Annual review of genetics}, volume = {41}, number = {}, pages = {147-168}, doi = {10.1146/annurev.genet.41.110306.130134}, pmid = {17600460}, issn = {0066-4197}, mesh = {Eukaryota/*ultrastructure ; Gene Transfer Techniques ; Plants/*ultrastructure ; *Plasmids ; Symbiosis ; }, abstract = {The establishment of the photosynthetic organelle (plastid) in eukaryotes and the diversification of algae and plants were landmark evolutionary events because these taxa form the base of the food chain for many ecosystems on our planet. The plastid originated via a putative single, ancient primary endosymbiosis in which a heterotrophic protist engulfed and retained a cyanobacterium in its cytoplasm. Once successfully established, this plastid spread into other protist lineages through eukaryote-eukaryote (secondary and tertiary) endosymbioses. This process of serial cell capture and enslavement explains the diversity of photosynthetic eukaryotes. Recent genomic and phylogenomic approaches have significantly clarified plastid genome evolution, the movement of endosymbiont genes to the "host" nuclear genome (endosymbiotic gene transfer), and plastid spread throughout the eukaryotic tree of life. Here we review these aspects of plastid evolution with a focus on understanding early events in plastid endosymbiosis.}, }
@article {pmid17594494, year = {2007}, author = {Desjardins, CA and Gundersen-Rindal, DE and Hostetler, JB and Tallon, LJ and Fuester, RW and Schatz, MC and Pedroni, MJ and Fadrosh, DW and Haas, BJ and Toms, BS and Chen, D and Nene, V}, title = {Structure and evolution of a proviral locus of Glyptapanteles indiensis bracovirus.}, journal = {BMC microbiology}, volume = {7}, number = {}, pages = {61}, pmid = {17594494}, issn = {1471-2180}, mesh = {Animals ; Base Composition ; DNA, Viral/chemistry/genetics ; *Evolution, Molecular ; Genome, Insect ; Genome, Viral ; Male ; Molecular Sequence Data ; Polydnaviridae/*genetics ; *Polymorphism, Genetic ; Proviruses/*genetics ; Sequence Analysis, DNA ; Wasps/*genetics/*virology ; }, abstract = {BACKGROUND: Bracoviruses (BVs), a group of double-stranded DNA viruses with segmented genomes, are mutualistic endosymbionts of parasitoid wasps. Virus particles are replication deficient and are produced only by female wasps from proviral sequences integrated into the wasp genome. Virus particles are injected along with eggs into caterpillar hosts, where viral gene expression facilitates parasitoid survival and therefore perpetuation of proviral DNA. Here we describe a 223 kbp region of Glyptapanteles indiensis genomic DNA which contains a part of the G. indiensis bracovirus (GiBV) proviral genome.<br><br>RESULTS: Eighteen of ~24 GiBV viral segment sequences are encoded by 7 non-overlapping sets of BAC clones, revealing that some proviral segment sequences are separated by long stretches of intervening DNA. Two overlapping BACs, which contain a locus of 8 tandemly arrayed proviral segments flanked on either side by ~35 kbp of non-packaged DNA, were sequenced and annotated. Structural and compositional analyses of this cluster revealed it exhibits a G+C and nucleotide composition distinct from the flanking DNA. By analyzing sequence polymorphisms in the 8 GiBV viral segment sequences, we found evidence for widespread selection acting on both protein-coding and non-coding DNA. Comparative analysis of viral and proviral segment sequences revealed a sequence motif involved in the excision of proviral genome segments which is highly conserved in two other bracoviruses.<br><br>CONCLUSION: Contrary to current concepts of bracovirus proviral genome organization our results demonstrate that some but not all GiBV proviral segment sequences exist in a tandem array. Unexpectedly, non-coding DNA in the 8 proviral genome segments which typically occupies ~70% of BV viral genomes is under selection pressure suggesting it serves some function(s). We hypothesize that selection acting on GiBV proviral sequences maintains the genetic island-like nature of the cluster of proviral genome segments described herein. In contrast to large differences in the predicted gene composition of BV genomes, sequences that appear to mediate processes of viral segment formation, such as proviral segment excision and circularization, appear to be highly conserved, supporting the hypothesis of a single origin for BVs.}, }
@article {pmid17573800, year = {2007}, author = {Reddy D M R, S and Schorderet, M and Feller, U and Reinhardt, D}, title = {A petunia mutant affected in intracellular accommodation and morphogenesis of arbuscular mycorrhizal fungi.}, journal = {The Plant journal : for cell and molecular biology}, volume = {51}, number = {5}, pages = {739-750}, doi = {10.1111/j.1365-313X.2007.03175.x}, pmid = {17573800}, issn = {0960-7412}, mesh = {Gene Expression ; Genes, Plant ; Mutation ; Mycorrhizae/*growth &amp; development/physiology ; Petunia/genetics/*microbiology/physiology ; Phenotype ; Phosphates/metabolism ; Plant Shoots/metabolism ; Symbiosis/*genetics/physiology ; }, abstract = {The regulation of the arbuscular mycorrhizal (AM) symbiosis is largely under the control of a genetic programme of the plant host. This programme includes a common symbiosis signalling pathway that is shared with the root nodule symbiosis. Whereas this common pathway has been investigated in detail, little is known about the mycorrhiza-specific regulatory steps upstream and downstream of the common pathway. To get further insight in the regulation of the AM symbiosis, a transposon-mutagenized population of Petunia hybrida was screened for mutants with defects in AM development. Here, we describe a petunia mutant, penetration and arbuscule morphogenesis1 (pam1), which is characterized by a strong decrease in colonization by three different AM fungi. Penetrating hyphae are frequently aborted in epidermal cells. Occasionally the fungus can progress to the cortex, but fails to develop arbuscules. The resulting hyphal colonization of the cortex in mutant plants does not support symbiotic acquisition of phosphate and copper by the plant. Expression analysis of three petunia orthologues of the common SYM genes LjPOLLUX, LjSYMRK and MtDMI3 indicates that pam1 is not mutated in these genes. We conclude that the PAM1 gene may play a specific role in intracellular accommodation and morphogenesis of the fungal endosymbiont.}, }
@article {pmid17571923, year = {2007}, author = {Toivonen, JM and Walker, GA and Martinez-Diaz, P and Bjedov, I and Driege, Y and Jacobs, HT and Gems, D and Partridge, L}, title = {No influence of Indy on lifespan in Drosophila after correction for genetic and cytoplasmic background effects.}, journal = {PLoS genetics}, volume = {3}, number = {6}, pages = {e95}, pmid = {17571923}, issn = {1553-7404}, support = {/WT_/Wellcome Trust/United Kingdom ; BB/C51705X/1/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; SF19106/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Caenorhabditis elegans/genetics/physiology ; Cytoplasm/genetics/*physiology ; DNA, Mitochondrial/physiology ; Dicarboxylic Acid Transporters/genetics/*physiology ; Drosophila/*genetics/growth &amp; development/physiology ; Drosophila Proteins/genetics/*physiology ; Female ; Longevity/*genetics/physiology ; Male ; Mitochondria/genetics/physiology ; Molecular Sequence Data ; Mutation ; Symporters/genetics/*physiology ; }, abstract = {To investigate whether alterations in mitochondrial metabolism affect longevity in Drosophila melanogaster, we studied lifespan in various single gene mutants, using inbred and outbred genetic backgrounds. As positive controls we included the two most intensively studied mutants of Indy, which encodes a Drosophila Krebs cycle intermediate transporter. It has been reported that flies heterozygous for these Indy mutations, which lie outside the coding region, show almost a doubling of lifespan. We report that only one of the two mutants lowers mRNA levels, implying that the lifespan extension observed is not attributable to the Indy mutations themselves. Moreover, neither Indy mutation extended lifespan in female flies in any genetic background tested. In the original genetic background, only the Indy mutation associated with altered RNA expression extended lifespan in male flies. However, this effect was abolished by backcrossing into standard outbred genetic backgrounds, and was associated with an unidentified locus on the X chromosome. The original Indy line with long-lived males is infected by the cytoplasmic symbiont Wolbachia, and the longevity of Indy males disappeared after tetracycline clearance of this endosymbiont. These findings underscore the critical importance of standardisation of genetic background and of cytoplasm in genetic studies of lifespan, and show that the lifespan extension previously claimed for Indy mutants was entirely attributable to confounding variation from these two sources. In addition, we saw no effects on lifespan of expression knockdown of the Indy orthologues nac-2 and nac-3 in the nematode Caenorhabditis elegans.}, }
@article {pmid17567535, year = {2007}, author = {Horn, S and Ehlers, K and Fritzsch, G and Gil-Rodríguez, MC and Wilhelm, C and Schnetter, R}, title = {Synchroma grande spec. nov. (Synchromophyceae class. nov., Heterokontophyta): an amoeboid marine alga with unique plastid complexes.}, journal = {Protist}, volume = {158}, number = {3}, pages = {277-293}, doi = {10.1016/j.protis.2007.02.004}, pmid = {17567535}, issn = {1434-4610}, mesh = {Algal Proteins/genetics ; Cell Membrane/ultrastructure ; Chloroplasts/ultrastructure ; DNA, Algal/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Eukaryota/*classification/genetics/ultrastructure ; Genes, rRNA ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; Pigments, Biological/biosynthesis ; Plastids/*ultrastructure ; RNA, Algal/genetics ; RNA, Ribosomal, 18S/genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; }, abstract = {Chromist algae including the Heterokontophyta are supposed to have evolved monophyletically by secondary endosymbiosis from a eukaryotic host cell that engulfed a eukaryotic red alga. The red algal endosymbiont was then reduced to a secondary plastid surrounded by four enveloping membranes. On the basis of the amoeboid marine alga Synchroma grande gen. et spec. nov., the Synchromophyceae are described here as a new class of Heterokontophyta. Their taxonomic position is characterized by 18S rRNA and rbcL gene phylogenies, morphology, and pigment composition. The so far unique feature of the Synchromophyceae is the occurrence of conspicuous chloroplast complexes representing multiplastidic red secondary endosymbionts. In these remarkable secondary endosymbionts, several primary chloroplasts are aggregated in a common periplastidial compartment and are collectively enveloped by an additional outer membrane pair. The discovery of this novel plastid morphology is highly relevant for research on algal evolution and is discussed in terms of the postulated monophyletic origin of Chromista.}, }
@article {pmid17565672, year = {2007}, author = {Kiraga, J and Mackiewicz, P and Mackiewicz, D and Kowalczuk, M and Biecek, P and Polak, N and Smolarczyk, K and Dudek, MR and Cebrat, S}, title = {The relationships between the isoelectric point and: length of proteins, taxonomy and ecology of organisms.}, journal = {BMC genomics}, volume = {8}, number = {}, pages = {163}, pmid = {17565672}, issn = {1471-2164}, mesh = {Base Composition/genetics ; Computational Biology ; *Ecosystem ; Isoelectric Point ; Mutation/genetics ; *Phylogeny ; Proteins/*chemistry ; Proteomics/*methods ; Species Specificity ; }, abstract = {BACKGROUND: The distribution of isoelectric point (pI) of proteins in a proteome is universal for all organisms. It is bimodal dividing the proteome into two sets of acidic and basic proteins. Different species however have different abundance of acidic and basic proteins that may be correlated with taxonomy, subcellular localization, ecological niche of organisms and proteome size.<br><br>RESULTS: We have analysed 1784 proteomes encoded by chromosomes of Archaea, Bacteria, Eukaryota, and also mitochondria, plastids, prokaryotic plasmids, phages and viruses. We have found significant correlation in more than 95% of proteomes between the protein length and pI in proteomes--positive for acidic proteins and negative for the basic ones. Plastids, viruses and plasmids encode more basic proteomes while chromosomes of Archaea, Bacteria, Eukaryota, mitochondria and phages more acidic ones. Mitochondrial proteomes of Viridiplantae, Protista and Fungi are more basic than Metazoa. It results from the presence of basic proteins in the former proteomes and their absence from the latter ones and is related with reduction of metazoan genomes. Significant correlation was found between the pI bias of proteomes encoded by prokaryotic chromosomes and proteomes encoded by plasmids but there is no correlation between eukaryotic nuclear-coded proteomes and proteomes encoded by organelles. Detailed analyses of prokaryotic proteomes showed significant relationships between pI distribution and habitat, relation to the host cell and salinity of the environment, but no significant correlation with oxygen and temperature requirements. The salinity is positively correlated with acidicity of proteomes. Host-associated organisms and especially intracellular species have more basic proteomes than free-living ones. The higher rate of mutations accumulation in the intracellular parasites and endosymbionts is responsible for the basicity of their tiny proteomes that explains the observed positive correlation between the decrease of genome size and the increase of basicity of proteomes. The results indicate that even conserved proteins subjected to strong selectional constraints follow the global trend in the pI distribution.<br><br>CONCLUSION: The distribution of pI of proteins in proteomes shows clear relationships with length of proteins, subcellular localization, taxonomy and ecology of organisms. The distribution is also strongly affected by mutational pressure especially in intracellular organisms.}, }
@article {pmid17565107, year = {2007}, author = {Vrijenhoek, RC and Duhaime, M and Jones, WJ}, title = {Subtype variation among bacterial endosymbionts of tubeworms (Annelida: Siboglinidae) from the Gulf of California.}, journal = {The Biological bulletin}, volume = {212}, number = {3}, pages = {180-184}, doi = {10.2307/25066600}, pmid = {17565107}, issn = {0006-3185}, mesh = {Animals ; Annelida/*microbiology ; California ; Gammaproteobacteria/*classification/physiology ; Phylogeny ; RNA, Ribosomal, 16S/chemistry ; Ribulose-Bisphosphate Carboxylase/chemistry ; Species Specificity ; Symbiosis ; }, }
@article {pmid17562224, year = {2007}, author = {Tsai, KH and Huang, CG and Wang, LC and Yu, YW and Wu, WJ and Chen, WJ}, title = {Molecular evidence for the endosymbiont Wolbachia in a non-filaroid nematode, Angiostrongylus cantonensis.}, journal = {Journal of biomedical science}, volume = {14}, number = {5}, pages = {607-615}, doi = {10.1007/s11373-007-9181-3}, pmid = {17562224}, issn = {1021-7770}, mesh = {Angiostrongylus cantonensis/*microbiology ; Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Base Sequence ; Cytoskeletal Proteins/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*classification/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia harbored by most filarial parasites, is critical to both embryogenesis and microfilarial development, and may lead to inflammation and pathogenesis in infected hosts. Based on alignment of the sequences from the wsp, ftsZ, and 16S rRNA genes, Wolbachia was demonstrated to exist in Angiostrongylus cantonensis, a non-filaroid nematode. Although the wsp gene may not be the best candidate for evolutionary analysis of Wolbachia, this gene has been sequenced from a broader coverage of the host species, making it feasible to be used for phylogenetic analysis in this study. The results from both Neighbor-joining and Maximum parsimony methods showed that this novel Wolbachia does not belong to any of the known groups (C or D) of nematode-derived Wolbachia. In addition, the wsp gene sequence of this newly identified endosymbiont revealed a high degree of identity (98%) with that from Diaea circumlita c2, tentatively classified into the putative group G. This suggests that Wolbachia from A. cantonensis could represent a deeply branched lineage in Wolbachia evolution or the occurrence of horizontal transfer between infected hosts. In conclusion, the findings provide some insights into our understanding of the evolution of Wolbachia, particularly the isolate from A. cantonensis.}, }
@article {pmid17554631, year = {2007}, author = {Enigl, M and Schausberger, P}, title = {Incidence of the endosymbionts Wolbachia, Cardinium and Spiroplasma in phytoseiid mites and associated prey.}, journal = {Experimental &amp; applied acarology}, volume = {42}, number = {2}, pages = {75-85}, pmid = {17554631}, issn = {0168-8162}, mesh = {Animals ; Bacteroidetes/genetics/*growth &amp; development ; DNA, Bacterial/chemistry/genetics ; Incidence ; Mites/*microbiology ; Pest Control, Biological/methods ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Spiroplasma/genetics/*growth &amp; development ; Symbiosis ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {Endosymbiotic bacteria that potentially influence reproduction and other fitness-related traits of their hosts are widespread in insects and mites and their appeal to researchers' interest is still increasing. We screened 20 strains of 12 agriculturally relevant herbivorous and predatory mite species for infection with Wolbachia, Cardinium and Spiroplasma by the use of PCR. The majority of specimens originated from Austria and were field collected or mass-reared. Eight out of 20 strains (40%) tested, representing seven of 12 mite species (58%), carried at least one of the three bacteria. We found Wolbachia in the herbivorous spider mites Tetranychus urticae and Bryobia rubrioculus, with the former also carrying Spiroplasma and the latter also carrying Cardinium. Cardinium was furthermore found in two populations of the predatory mite Euseius finlandicus and the spider mite Eotetranychus uncatus. Spiroplasma was detected in the predatory mite Neoseiulus californicus. All bacteria positive PCR products were sequenced, submitted to GenBank and analyzed in BLAST queries. We found high similarities to complete identity with bacteria found in the same and different mite species but also with bacteria found in insect species like ladybirds, butterflies and minute pirate bugs, Orius. We discuss the significance of potential (multiple) infections with the investigated bacteria for biological control.}, }
@article {pmid17550764, year = {2007}, author = {Valdivia, RH and Heitman, J}, title = {Endosymbiosis: the evil within.}, journal = {Current biology : CB}, volume = {17}, number = {11}, pages = {R408-10}, doi = {10.1016/j.cub.2007.04.001}, pmid = {17550764}, issn = {0960-9822}, mesh = {Amoeba/microbiology/pathogenicity ; Animals ; Burkholderia/genetics/*physiology ; Candida albicans/pathogenicity/physiology ; Chlamydiales/physiology ; Genome, Bacterial ; Mycotoxins/biosynthesis ; Oryza/microbiology ; Pseudomonas aeruginosa/genetics/physiology ; Rhizopus/pathogenicity/*physiology ; Spores, Fungal/growth &amp; development ; *Symbiosis ; Virulence ; Virulence Factors/genetics ; }, abstract = {A recent study has revealed a novel feature of the symbiosis between a bacterium and a fungal pathogen. In addition to producing a pathogenic toxin, the endosymbiont of the rice pathogen Rhizopus microsporus controls the ability of the fungus to form sporangia and spores.}, }
@article {pmid17550603, year = {2007}, author = {Marin, B and Nowack, EC and Glöckner, G and Melkonian, M}, title = {The ancestor of the Paulinella chromatophore obtained a carboxysomal operon by horizontal gene transfer from a Nitrococcus-like gamma-proteobacterium.}, journal = {BMC evolutionary biology}, volume = {7}, number = {}, pages = {85}, pmid = {17550603}, issn = {1471-2148}, mesh = {Amino Acid Sequence ; Amoeba/*genetics ; Animals ; Base Sequence ; DNA, Chloroplast ; Evolution, Molecular ; Gammaproteobacteria/*genetics ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Molecular Sequence Data ; *Operon ; *Phylogeny ; RNA, Ribosomal/genetics ; Sequence Alignment ; }, abstract = {BACKGROUND: Paulinella chromatophora is a freshwater filose amoeba with photosynthetic endosymbionts (chromatophores) of cyanobacterial origin that are closely related to free-living Prochlorococcus and Synechococcus species (PS-clade). Members of the PS-clade of cyanobacteria contain a proteobacterial form 1A RubisCO (ribulose-1,5-bisphosphate carboxylase/oxygenase) that was acquired by horizontal gene transfer (HGT) of a carboxysomal operon. In rDNA-phylogenies, the Paulinella chromatophore diverged basal to the PS-clade, raising the question whether the HGT occurred before or after the split of the chromatophore ancestor.<br><br>RESULTS: Phylogenetic analyses of the almost complete rDNA operon with an improved taxon sampling containing most known cyanobacterial lineages recovered the Paulinella chromatophore as sister to the complete PS-clade. The sequence of the complete carboxysomal operon of Paulinella was determined. Analysis of RubisCO large subunit (rbcL) sequences revealed that Paulinella shares the proteobacterial form 1A RubisCO with the PS-clade. The gamma-proteobacterium Nitrococcus mobilis was identified as sister of the Paulinella chromatophore and the PS-clade in the RubisCO phylogeny. Gene content and order in the carboxysomal operon correlates well with the RubisCO phylogeny demonstrating that the complete carboxysomal operon was acquired by the common ancestor of the Paulinella chromatophore and the PS-clade through HGT. The carboxysomal operon shows a significantly elevated AT content in Paulinella, which in the rbcL gene is confined to third codon positions. Combined phylogenies using rbcL and the rDNA-operon resulted in a nearly fully resolved tree of the PS-clade.<br><br>CONCLUSION: The HGT of the carboxysomal operon predated the divergence of the chromatophore ancestor from the PS-clade. Following HGT and divergence of the chromatophore ancestor, diversification of the PS-clade into at least three subclades occurred. The gamma-proteobacterium Nitrococcus mobilis represents the closest known relative to the donor of the carboxysomal operon. The isolated position of the Paulinella chromatophore in molecular phylogenies as well as its elevated AT content suggests that the Paulinella chromatophore has already undergone typical steps in the reductive evolution of an endosymbiont.}, }
@article {pmid17547756, year = {2007}, author = {Viñuelas, J and Calevro, F and Remond, D and Bernillon, J and Rahbé, Y and Febvay, G and Fayard, JM and Charles, H}, title = {Conservation of the links between gene transcription and chromosomal organization in the highly reduced genome of Buchnera aphidicola.}, journal = {BMC genomics}, volume = {8}, number = {}, pages = {143}, pmid = {17547756}, issn = {1471-2164}, mesh = {Analysis of Variance ; Animals ; Aphids/microbiology ; Buchnera/*genetics ; Chromosomes, Bacterial/*genetics ; DNA, Bacterial ; Evolution, Molecular ; Genes, Bacterial ; Genome, Bacterial/*genetics ; Oligonucleotide Array Sequence Analysis ; RNA, Messenger/genetics ; Reproducibility of Results ; *Transcription, Genetic ; }, abstract = {BACKGROUND: Genomic studies on bacteria have clearly shown the existence of chromosomal organization as regards, for example, to gene localization, order and orientation. Moreover, transcriptomic analyses have demonstrated that, in free-living bacteria, gene transcription levels and chromosomal organization are mutually influenced. We have explored the possible conservation of relationships between mRNA abundances and chromosomal organization in the highly reduced genome of Buchnera aphidicola, the primary endosymbiont of the aphids, and a close relative to Escherichia coli.<br><br>RESULTS: Using an oligonucleotide-based microarray, we normalized the transcriptomic data by genomic DNA signals in order to have access to inter-gene comparison data. Our analysis showed that mRNA abundances, gene organization (operon) and gene essentiality are correlated in Buchnera (i.e., the most expressed genes are essential genes organized in operons) whereas no link between mRNA abundances and gene strand bias was found. The effect of Buchnera genome evolution on gene expression levels has also been analysed in order to assess the constraints imposed by the obligate symbiosis with aphids, underlining the importance of some gene sets for the survival of the two partners. Finally, our results show the existence of spatial periodic transcriptional patterns in the genome of Buchnera.<br><br>CONCLUSION: Despite an important reduction in its genome size and an apparent decay of its capacity for regulating transcription, this work reveals a significant correlation between mRNA abundances and chromosomal organization of the aphid-symbiont Buchnera.}, }
@article {pmid17547748, year = {2007}, author = {Huang, J and Gogarten, JP}, title = {Did an ancient chlamydial endosymbiosis facilitate the establishment of primary plastids?.}, journal = {Genome biology}, volume = {8}, number = {6}, pages = {R99}, pmid = {17547748}, issn = {1474-760X}, mesh = {Biological Evolution ; Chlamydia/*genetics/physiology ; Cyanobacteria/genetics ; Gene Transfer, Horizontal ; Genes, Bacterial ; Phylogeny ; Plastids/*genetics ; Rhodophyta/*genetics/physiology ; *Symbiosis ; }, abstract = {BACKGROUND: Ancient endosymbioses are responsible for the origins of mitochondria and plastids, and they contribute to the divergence of several major eukaryotic groups. Although chlamydiae, a group of obligate intracellular bacteria, are not found in plants, an unexpected number of chlamydial genes are most similar to plant homologs, which, interestingly, often contain a plastid-targeting signal. This observation has prompted several hypotheses, including gene transfer between chlamydiae and plant-related groups and an ancestral relationship between chlamydiae and cyanobacteria.<br><br>RESULTS: We conducted phylogenomic analyses of the red alga Cyanidioschyzon merolae to identify genes specifically related to chlamydial homologs. We show that at least 21 genes were transferred between chlamydiae and primary photosynthetic eukaryotes, with the donor most similar to the environmental Protochlamydia. Such an unusually high number of transferred genes suggests an ancient chlamydial endosymbiosis with the ancestral primary photosynthetic eukaryote. We hypothesize that three organisms were involved in establishing the primary photosynthetic lineage: the eukaryotic host cell, the cyanobacterial endosymbiont that provided photosynthetic capability, and a chlamydial endosymbiont or parasite that facilitated the establishment of the cyanobacterial endosymbiont.<br><br>CONCLUSION: Our findings provide a glimpse into the complex interactions that were necessary to establish the primary endosymbiotic relationship between plastid and host cytoplasms, and thereby explain the rarity with which long-term successful endosymbiotic relationships between heterotrophs and photoautotrophs were established. Our data also provide strong and independent support for a common origin of all primary photosynthetic eukaryotes and of the plastids they harbor.}, }
@article {pmid17542845, year = {2007}, author = {Lozier, JD and Roderick, GK and Mills, NJ}, title = {Genetic evidence from mitochondrial, nuclear, and endosymbiont markers for the evolution of host plant associated species in the aphid genus Hyalopterus (Hemiptera: Aphididae).}, journal = {Evolution; international journal of organic evolution}, volume = {61}, number = {6}, pages = {1353-1367}, doi = {10.1111/j.1558-5646.2007.00110.x}, pmid = {17542845}, issn = {0014-3820}, mesh = {Animals ; Aphids/genetics/microbiology/*physiology ; Biodiversity ; *Biological Evolution ; Buchnera/genetics/physiology ; California ; Cluster Analysis ; DNA, Mitochondrial/chemistry ; Feeding Behavior ; Gene Flow ; Genetic Markers ; Genotype ; Geography ; Mediterranean Region ; Microsatellite Repeats ; Phylogeny ; Polymorphism, Genetic ; Prunus/physiology ; Species Specificity ; }, abstract = {Over the past several decades biologists' fascination with plant-herbivore interactions has generated intensive research into the implications of these interactions for insect diversification. The study of closely related phytophagous insect species or populations from an evolutionary perspective can help illuminate ecological and selective forces that drive these interactions. Here we present such an analysis for aphids in the genus Hyalopterus (Hemiptera: Aphididae), a cosmopolitan group that feeds on plants in the genus Prunus (Rosaceae). Hyalopterus currently contains two recognized species associated with different Prunus species, although the taxonomy and evolutionary history of the group is poorly understood. Using mitochondrial COI sequences, 16S rDNA sequences from the aphid endosymbiont Buchnera aphidicola, and nine microsatellite loci we investigated population structure in Hyalopterus from the most commonly used Prunus host species throughout the Mediterranean as well as in California, where the species H. pruni is an invasive pest. We found three deeply divergent lineages structured in large part by specific associations with plum, almond, and peach trees. There was no evidence that geographic or temporal barriers could explain the overall diversity in the genus. Levels of genetic differentiation are consistent with that typically attributed to aphid species and indicate divergence times older than the domestication of Prunus for agriculture. Interestingly, in addition to their typical hosts, aphids from each of the three lineages were frequently found on apricot trees. Apricot also appears to act as a resource mediated hybrid zone for plum and almond associated lineages. Together, results suggest that host plants have played a role in maintaining host-associated differentiation in Hyalopterus for as long as several million years, despite worldwide movement of host plants and the potential for ongoing hybridization.}, }
@article {pmid17537638, year = {2007}, author = {Bodył, A and Mackiewicz, P and Stiller, JW}, title = {The intracellular cyanobacteria of Paulinella chromatophora: endosymbionts or organelles?.}, journal = {Trends in microbiology}, volume = {15}, number = {7}, pages = {295-296}, doi = {10.1016/j.tim.2007.05.002}, pmid = {17537638}, issn = {0966-842X}, mesh = {Amoeba/cytology/*microbiology/physiology ; Animals ; Biological Evolution ; Cyanobacteria/classification/*physiology ; Organelles/classification/*physiology ; Symbiosis/*physiology ; }, abstract = {Endosymbiotic relationships are common across the tree of life and have had profound impacts on cellular evolution and diversity. Recent molecular investigations of the amoeba Paulinella chromatophora have raised a timely and important question: should obligatory intracellular cyanobacteria in Paulinella be considered new organelles, or do plastids and mitochondria hold a unique stature in the history of endosymbiotic events? We argue that drawing a sharp distinction between these two organelles and all other endosymbionts is not supported by accumulating data, neither is it a productive framework for investigating organelle evolution.}, }
@article {pmid17522086, year = {2007}, author = {Khan, H and Parks, N and Kozera, C and Curtis, BA and Parsons, BJ and Bowman, S and Archibald, JM}, title = {Plastid genome sequence of the cryptophyte alga Rhodomonas salina CCMP1319: lateral transfer of putative DNA replication machinery and a test of chromist plastid phylogeny.}, journal = {Molecular biology and evolution}, volume = {24}, number = {8}, pages = {1832-1842}, doi = {10.1093/molbev/msm101}, pmid = {17522086}, issn = {0737-4038}, mesh = {Bacteria/*genetics ; Cryptophyta/*genetics ; *DNA Replication ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genes, Plant ; *Genome ; Phylogeny ; Plastids/*genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Cryptophytes are a group of unicellular algae with chlorophyll c-containing plastids derived from the uptake of a secondary (i.e., eukaryotic) endosymbiont. Biochemical and molecular data indicate that cryptophyte plastids are derived from red algae, yet the question of whether or not cryptophytes acquired their red algal plastids independent of those in heterokont, haptophyte, and dinoflagellate algae is of long-standing debate. To better understand the origin and evolution of the cryptophyte plastid, we have sequenced the plastid genome of Rhodomonas salina CCMP1319: at 135,854 bp, it is the largest secondary plastid genome characterized thus far. It also possesses interesting features not seen in the distantly related cryptophyte Guillardia theta or in other red secondary plastids, including pseudogenes, introns, and a bacterial-derived gene for the tau/gamma subunit of DNA polymerase III (dnaX), the first time putative DNA replication machinery has been found encoded in any plastid genome. Phylogenetic analyses indicate that dnaX was acquired by lateral gene transfer (LGT) in an ancestor of Rhodomonas, most likely from a firmicute bacterium. A phylogenomic survey revealed no additional cases of LGT, beyond a noncyanobacterial type rpl36 gene similar to that recently characterized in other cryptophytes and haptophytes. Rigorous concatenated analysis of 45 proteins encoded in 15 complete plastid genomes produced trees in which the heterokont, haptophyte, and cryptophyte (i.e., chromist) plastids were monophyletic, and heterokonts and haptophytes were each other's closest relatives. However, statistical support for chromist monophyly disappears when amino acids are recoded according to their chemical properties in order to minimize the impact of composition bias, and a significant fraction of the concatenate appears consistent with a sister-group relationship between cryptophyte and haptophyte plastids.}, }
@article {pmid17511520, year = {2007}, author = {Sirand-Pugnet, P and Lartigue, C and Marenda, M and Jacob, D and Barré, A and Barbe, V and Schenowitz, C and Mangenot, S and Couloux, A and Segurens, B and de Daruvar, A and Blanchard, A and Citti, C}, title = {Being pathogenic, plastic, and sexual while living with a nearly minimal bacterial genome.}, journal = {PLoS genetics}, volume = {3}, number = {5}, pages = {e75}, pmid = {17511520}, issn = {1553-7404}, mesh = {Animals ; Bacterial Proteins/genetics ; DNA Restriction-Modification Enzymes ; DNA, Circular/genetics ; DNA, Ribosomal/genetics ; Gene Transfer, Horizontal ; Genes, Bacterial ; Genetic Variation ; *Genome, Bacterial/genetics/physiology ; Lipoproteins/genetics ; Molecular Sequence Data ; Mycoplasma agalactiae/*genetics/*physiology ; Mycoplasma mycoides/genetics ; Phylogeny ; Regulatory Sequences, Nucleic Acid/genetics ; Ruminants/microbiology ; }, abstract = {Mycoplasmas are commonly described as the simplest self-replicating organisms, whose evolution was mainly characterized by genome downsizing with a proposed evolutionary scenario similar to that of obligate intracellular bacteria such as insect endosymbionts. Thus far, analysis of mycoplasma genomes indicates a low level of horizontal gene transfer (HGT) implying that DNA acquisition is strongly limited in these minimal bacteria. In this study, the genome of the ruminant pathogen Mycoplasma agalactiae was sequenced. Comparative genomic data and phylogenetic tree reconstruction revealed that approximately 18% of its small genome (877,438 bp) has undergone HGT with the phylogenetically distinct mycoides cluster, which is composed of significant ruminant pathogens. HGT involves genes often found as clusters, several of which encode lipoproteins that usually play an important role in mycoplasma-host interaction. A decayed form of a conjugative element also described in a member of the mycoides cluster was found in the M. agalactiae genome, suggesting that HGT may have occurred by mobilizing a related genetic element. The possibility of HGT events among other mycoplasmas was evaluated with the available sequenced genomes. Our data indicate marginal levels of HGT among Mycoplasma species except for those described above and, to a lesser extent, for those observed in between the two bird pathogens, M. gallisepticum and M. synoviae. This first description of large-scale HGT among mycoplasmas sharing the same ecological niche challenges the generally accepted evolutionary scenario in which gene loss is the main driving force of mycoplasma evolution. The latter clearly differs from that of other bacteria with small genomes, particularly obligate intracellular bacteria that are isolated within host cells. Consequently, mycoplasmas are not only able to subvert complex hosts but presumably have retained sexual competence, a trait that may prevent them from genome stasis and contribute to adaptation to new hosts.}, }
@article {pmid17504498, year = {2007}, author = {Heinz, E and Kolarov, I and Kästner, C and Toenshoff, ER and Wagner, M and Horn, M}, title = {An Acanthamoeba sp. containing two phylogenetically different bacterial endosymbionts.}, journal = {Environmental microbiology}, volume = {9}, number = {6}, pages = {1604-1609}, pmid = {17504498}, issn = {1462-2912}, mesh = {Acanthamoeba/*microbiology/*ultrastructure ; Animals ; Betaproteobacteria/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/chemistry ; DNA, Protozoan/chemistry ; Molecular Sequence Data ; RNA, Ribosomal, 16S/analysis/chemistry ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Acanthamoebae are ubiquitous free-living amoebae and important predators of microbial communities. They frequently contain obligate intracellular bacterial symbionts, which show a worldwide distribution. All Acanthamoeba spp. described so far harboured no or only a single specific endosymbiont phylotype, and in some cases evidence for coevolution between the symbiotic bacteria and the amoeba host has been reported. In this study we have isolated and characterized an Acanthamoeba sp. (strain OEW1) showing a stable symbiotic relationship with two morphologically different endosymbionts. 16S rRNA sequence analysis assigned these symbionts to the candidate genus Procabacter (Betaproteobacteria) and the genus Parachlamydia (Chlamydiae) respectively. Fluorescence in situ hybridization and transmission electron microscopy confirmed the affiliation of the endosymbionts and showed their co-occurrence in the amoeba host cells and their intracellular location within separate compartments enclosed by host-derived membranes. Further analysis of this stable relationship should provide novel insights into the complex interactions of intracellular multiple-partner associations.}, }
@article {pmid17504480, year = {2007}, author = {Duperron, S and Sibuet, M and MacGregor, BJ and Kuypers, MM and Fisher, CR and Dubilier, N}, title = {Diversity, relative abundance and metabolic potential of bacterial endosymbionts in three Bathymodiolus mussel species from cold seeps in the Gulf of Mexico.}, journal = {Environmental microbiology}, volume = {9}, number = {6}, pages = {1423-1438}, doi = {10.1111/j.1462-2920.2007.01259.x}, pmid = {17504480}, issn = {1462-2912}, mesh = {Animals ; Atlantic Ocean ; Bacteria/classification/genetics/*growth &amp; development ; Bivalvia/classification/*microbiology ; Cold Temperature ; Methane/*metabolism ; Molecular Sequence Data ; RNA, Ribosomal/analysis/genetics ; Symbiosis/genetics/*physiology ; }, abstract = {Cold seeps in the Gulf of Mexico are often dominated by mussels of the genus Bathymodiolus that harbour symbiotic bacteria in their gills. In this study, we analysed symbiont diversity, abundance and metabolic potential in three mussel species from the northern Gulf of Mexico: Bathymodiolus heckerae from the West Florida Escarpment, Bathymodiolus brooksi from Atwater Valley and Alaminos Canyon, and 'Bathymodiolus' childressi, which co-occurs with B. brooksi in Alaminos Canyon. Comparative 16S rRNA sequence analysis confirmed a single methanotroph-related symbiont in 'B.' childressi and a dual symbiosis with a methanotroph- and thiotroph-related symbiont in B. brooksi. A previously unknown diversity of four co-occurring symbionts was discovered in B. heckerae: a methanotroph, two phylogenetically distinct thiotrophs and a methylotroph-related phylotype not previously described from any marine invertebrate symbiosis. A gene characteristic of methane-oxidzing bacteria, pmoA, was identified in all three mussel species confirming the methanotrophic potential of their symbionts. Stable isotope analyses of lipids and whole tissue also confirmed the importance of methanotrophy in the carbon nutrition of all of the mussels. Analyses of absolute and relative symbiont abundance in B. heckerae and B. brooksi using fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization indicated a clear dominance of methanotrophic over thiotrophic symbionts in their gill tissues. A site-dependent variability in total symbiont abundance was observed in B. brooksi, with specimens from Alaminos Canyon harbouring much lower densities than those from Atwater Valley. This shows that symbiont abundance is not species-specific but can vary considerably between populations.}, }
@article {pmid17503075, year = {2007}, author = {Trémouillaux-Guiller, J and Huss, VA}, title = {A cryptic intracellular green alga in Ginkgo biloba: ribosomal DNA markers reveal worldwide distribution.}, journal = {Planta}, volume = {226}, number = {2}, pages = {553-557}, pmid = {17503075}, issn = {0032-0935}, mesh = {Chlorophyta/genetics/*isolation &amp; purification/physiology ; DNA, Ribosomal/chemistry/*classification ; Genetic Markers ; Ginkgo biloba/*cytology/physiology ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Intracellular symbioses involving eukaryotic microalgae and a variety of heterotrophic protists and invertebrates are widespread, but are unknown in higher plants. Recently, we reported the isolation and molecular identification of a Coccomyxa-like green alga from in vitro cell cultures of Ginkgo biloba L. This alga resides intracellularly in an immature "precursor" form with a nonfunctional chloroplast, implying that algal photosynthetic activity has no role in this endosymbiosis. In necrotizing Ginkgo cells, precursors evolved into mature algae, proliferated, and were liberated into the culture medium after host cell bursting. In the present paper we demonstrate by molecular methods a worldwide distribution of the alga in planta. Endosymbiont-specific sequences of ribosomal DNA could be traced in Ginkgo tissues of each specimen examined from different geographic locations in Europe, North America, and Asia. The Ginkgo/Coccomyca association represents a new kind of intracellular, vertically inherited symbiosis. Storage bodies, probably of lipid nature, present in the cytoplasm of each partner suggest a possible involvement of the endosymbiont in metabolic pathways of its host.}, }
@article {pmid17498933, year = {2007}, author = {Karajan, BP and Vishnyakov, AE and Tavrovskaya, MV and Vasyanin, SI}, title = {Infection of algae-free Climacostomum virens with symbiotic Chlorella sp. isolated from algae-containing C. virens.}, journal = {European journal of protistology}, volume = {43}, number = {2}, pages = {141-146}, doi = {10.1016/j.ejop.2007.01.001}, pmid = {17498933}, issn = {0932-4739}, mesh = {Animals ; Chlorella/*cytology/*physiology ; Ciliophora/*cytology/*physiology ; Symbiosis/*physiology ; Vacuoles ; }, abstract = {The ciliate Climacostomum virens normally contains algae as symbionts in its cytoplasm and retains them over many generations. An aposymbiotic strain of C. virens which cannot re-establish a new symbiotic association by ingestion of algae derived from green Climacostomum was recently isolated in our laboratory. Results of infection experiments showed that all newly ingested, potentially symbiotic algae were digested in food vacuoles. To clarify whether these ciliates have completely lost their ability to sustain symbiosis with algae or whether this ability can eventually be re-established, infection experiments were performed using a microinjection technique. We have achieved successful infection of algae-free Climacostomum using this method. The endosymbiont population was established in ciliates from as few as 3-5 injected algae, which have retained an intact perialgal vacuole membrane around them. To our knowledge, this is the first evidence of successful infection of aposymbiotic ciliates with algae by microinjection.}, }
@article {pmid17496135, year = {2007}, author = {Narita, S and Kageyama, D and Nomura, M and Fukatsu, T}, title = {Unexpected mechanism of symbiont-induced reversal of insect sex: feminizing Wolbachia continuously acts on the butterfly Eurema hecabe during larval development.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {13}, pages = {4332-4341}, pmid = {17496135}, issn = {0099-2240}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Base Sequence ; Colony Count, Microbial ; Crustacea/growth &amp; development/microbiology ; DNA Primers/genetics ; DNA, Bacterial/genetics ; Disorders of Sex Development ; Female ; Feminization ; Insecta/growth &amp; development/microbiology ; Larva/growth &amp; development/microbiology ; Male ; Mosaicism ; Moths/drug effects/*growth &amp; development/*microbiology ; Phenotype ; Symbiosis/*physiology ; Wings, Animal/growth &amp; development ; Wolbachia/drug effects/genetics/isolation &amp; purification/*physiology ; }, abstract = {When the butterfly Eurema hecabe is infected with two different strains (wHecCI2 and wHecFem2) of the bacterial endosymbiont Wolbachia, genetic males are transformed into functional females, resulting in production of all-female broods. In an attempt to understand how and when the Wolbachia endosymbiont feminizes genetically male insects, larval insects were fed an antibiotic-containing diet beginning at different developmental stages until pupation. When the adult insects emerged, strikingly, many of them exhibited sexually intermediate traits in their wings, reproductive organs, and genitalia. The expression of intersexual phenotypes was strong in the insects treated from first instar, moderate in the insects treated from third instar, and weak in the insects treated from fourth instar. The insects treated from early larval instar grew and pupated normally but frequently failed to emerge and died in the pupal case. The dead insects in the pupal case contained lower densities of the feminizing Wolbachia endosymbiont than the successfully emerged insects, although none of them were completely cured of the symbiont infection. These results suggest the following: (i) the antibiotic treatment suppressed the population of feminizing Wolbachia endosymbionts; (ii) the suppression probably resulted in attenuated feminizing activity of the symbiont, leading to expression of intersexual host traits; (iii) many of the insects suffered pupal mortality, possibly due to either intersexual defects or Wolbachia-mediated addiction; and hence (iv) the feminizing Wolbachia endosymbiont continuously acts on the host insects during larval development for expression of female phenotypes under a male genotype. Our finding may prompt reconsideration of the notion that Wolbachia-induced reproductive manipulations are already complete before the early embryonic stage and provide insights into the mechanism underlying the symbiont-induced reversal of insect sex.}, }
@article {pmid17483203, year = {2007}, author = {Leidhold, C and Voos, W}, title = {Chaperones and proteases--guardians of protein integrity in eukaryotic organelles.}, journal = {Annals of the New York Academy of Sciences}, volume = {1113}, number = {}, pages = {72-86}, doi = {10.1196/annals.1391.011}, pmid = {17483203}, issn = {0077-8923}, mesh = {Animals ; Eukaryotic Cells/*enzymology/metabolism ; Humans ; Mitochondria/enzymology/physiology ; Molecular Chaperones/*physiology ; Organelles/*enzymology/physiology ; Peptide Hydrolases/*physiology ; }, abstract = {Organelles like mitochondria, chloroplasts, or the endoplasmic reticulum are essential subcompartments of eukaryotic cells that fulfill important metabolic tasks. Organellar protein homeostasis is maintained by a combination of specific protein biogenesis processes and protein quality control (PQC) mechanisms that together guarantee the functional state of the organelle. According to their endosymbiontic origin, mitochondria and chloroplasts contain internal PQC systems that consist of a cooperative network of molecular chaperones and proteases. In contrast, the endoplasmic reticulum employs the main cytosolic degradation machinery, the proteasome, for the removal of damaged or misfolded proteins. Here we present and discuss recent experimental insights into the molecular mechanisms underlying organellar PQC processes.}, }
@article {pmid17476724, year = {2007}, author = {Griffiths, J}, title = {Proteomics of the uncultured endosymbiont of Riftia pachyptila. How deep, fried worms eat.}, journal = {Analytical chemistry}, volume = {79}, number = {7}, pages = {2612}, doi = {10.1021/ac071888d}, pmid = {17476724}, issn = {0003-2700}, mesh = {Animals ; Carbon/metabolism ; Citric Acid Cycle ; Ecosystem ; Energy Metabolism ; Gammaproteobacteria/enzymology/metabolism ; Oxidation-Reduction ; Polychaeta/*microbiology ; *Proteomics ; Sulfur/metabolism ; *Symbiosis ; }, }
@article {pmid17476327, year = {2007}, author = {Zhong, J and Jasinskas, A and Barbour, AG}, title = {Antibiotic treatment of the tick vector Amblyomma americanum reduced reproductive fitness.}, journal = {PloS one}, volume = {2}, number = {5}, pages = {e405}, pmid = {17476327}, issn = {1932-6203}, mesh = {Animals ; *Arachnid Vectors ; Coxiella/isolation &amp; purification ; Female ; Male ; Polymerase Chain Reaction ; Reproduction/drug effects ; Rickettsia/isolation &amp; purification ; Rifampin/pharmacology ; Tetracycline/*pharmacology ; Ticks/microbiology/*physiology ; }, abstract = {BACKGROUND: The lone star tick Amblyomma americanum is a common pest and vector of infectious diseases for humans and other mammals in the southern and eastern United States. A Coxiella sp. bacterial endosymbiont was highly prevalent in both laboratory-reared and field-collected A. americanum. The Coxiella sp. was demonstrated in all stages of tick and in greatest densities in nymphs and adult females, while a Rickettsia sp. was less prevalent and in lower densities when present.<br><br>We manipulated the numbers of both bacterial species in laboratory-reared A. americanum by injecting engorged nymphs or engorged, mated females with single doses of an antibiotic (rifampin or tetracycline) or buffer alone. Burdens of the bacteria after molting or after oviposition were estimated by quantitative polymerase chain reaction with primers and probes specific for each bacterial species or, as an internal standard, the host tick. Post-molt adult ticks that had been treated with rifampin or tetracycline had lower numbers of the Coxiella sp. and Rickettsia sp. and generally weighed less than ticks that received buffer alone. Similarly, after oviposition, females treated previously with either antibiotic had lower burdens of both bacterial species in comparison to controls. Treatment of engorged females with either antibiotic was associated with prolonged time to oviposition, lower proportions of ticks that hatched, lower proportions of viable larvae among total larvae, and lower numbers of viable larvae per tick. These fitness estimators were associated with reduced numbers of the Coxiella sp. but not the Rickettsia sp.<br><br>CONCLUSION/SIGNIFICANCE: The findings indicate that the Coxiella sp. is a primary endosymbiont, perhaps provisioning the obligately hematophagous parasites with essential nutrients. The results also suggest that antibiotics could be incorporated into an integrated pest management plan for control of these and other tick vectors of disease.}, }
@article {pmid17472647, year = {2007}, author = {Musat, N and Giere, O and Gieseke, A and Thiermann, F and Amann, R and Dubilier, N}, title = {Molecular and morphological characterization of the association between bacterial endosymbionts and the marine nematode Astomonema sp. from the Bahamas.}, journal = {Environmental microbiology}, volume = {9}, number = {5}, pages = {1345-1353}, doi = {10.1111/j.1462-2920.2006.01232.x}, pmid = {17472647}, issn = {1462-2912}, mesh = {Animals ; Anthozoa ; Bacteria/*genetics ; Bahamas ; Gammaproteobacteria/*classification/genetics ; Geologic Sediments/microbiology ; Molecular Sequence Data ; Nematoda/classification/*microbiology/physiology ; Oxidoreductases Acting on Sulfur Group Donors/classification/genetics ; Phylogeny ; RNA, Ribosomal, 16S/classification ; Seawater/*microbiology ; Sulfur Compounds/metabolism ; Symbiosis/*physiology ; }, abstract = {Marine nematode worms without a mouth or functional gut are found worldwide in intertidal sandflats, deep-sea muds and methane-rich pock marks, and morphological studies show that they are associated with endosymbiotic bacteria. While it has been hypothesized that the symbionts are chemoautotrophic sulfur oxidizers, to date nothing is known about the phylogeny or function of endosymbionts from marine nematodes. In this study, we characterized the association between bacterial endosymbionts and the marine nematode Astomonema sp. from coral reef sediments in the Bahamas. Phylogenetic analysis of the host based on its 18S rRNA gene showed that Astomonema sp. is most closely related to non-symbiotic nematodes of the families Linhomoeidae and Axonolaimidae and is not closely related to marine stilbonematinid nematodes with ectosymbiotic sulfur-oxidizing bacteria. In contrast, phylogenetic analyses of the symbionts of Astomonema sp. using comparative 16S rRNA gene sequence analysis revealed that these are closely related to the stilbonematinid ectosymbionts (95-96% sequence similarity) as well as to the sulfur-oxidizing endosymbionts from gutless marine oligochaetes. The closest free-living relatives of these gammaproteobacterial symbionts are sulfur-oxidizing bacteria from the family Chromatiaceae. Transmission electron microscopy and fluorescence in situ hybridization showed that the bacterial symbionts completely fill the gut lumen of Astomonema sp., suggesting that these are their main source of nutrition. The close phylogenetic relationship of the Astomonema sp. symbionts to known sulfur-oxidizing bacteria as well as the presence of the aprA gene, typically found in sulfur-oxidizing bacteria, indicates that the Astomonema sp. symbionts use reduced sulfur compounds as an energy source to provide their hosts with nutrition.}, }
@article {pmid17470297, year = {2007}, author = {Brownlie, JC and Adamski, M and Slatko, B and McGraw, EA}, title = {Diversifying selection and host adaptation in two endosymbiont genomes.}, journal = {BMC evolutionary biology}, volume = {7}, number = {}, pages = {68}, pmid = {17470297}, issn = {1471-2148}, mesh = {*Adaptation, Physiological ; Animals ; Brugia malayi/genetics/*microbiology ; Drosophila melanogaster/genetics/*microbiology ; Genome ; Host-Parasite Interactions ; *Selection, Genetic ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {BACKGROUND: The endosymbiont Wolbachia pipientis infects a broad range of arthropod and filarial nematode hosts. These diverse associations form an attractive model for understanding host:symbiont coevolution. Wolbachia's ubiquity and ability to dramatically alter host reproductive biology also form the foundation of research strategies aimed at controlling insect pests and vector-borne disease. The Wolbachia strains that infect nematodes are phylogenetically distinct, strictly vertically transmitted, and required by their hosts for growth and reproduction. Insects in contrast form more fluid associations with Wolbachia. In these taxa, host populations are most often polymorphic for infection, horizontal transmission occurs between distantly related hosts, and direct fitness effects on hosts are mild. Despite extensive interest in the Wolbachia system for many years, relatively little is known about the molecular mechanisms that mediate its varied interactions with different hosts. We have compared the genomes of the Wolbachia that infect Drosophila melanogaster, wMel and the nematode Brugia malayi, wBm to that of an outgroup Anaplasma marginale to identify genes that have experienced diversifying selection in the Wolbachia lineages. The goal of the study was to identify likely molecular mechanisms of the symbiosis and to understand the nature of the diverse association across different hosts.<br><br>RESULTS: The prevalence of selection was far greater in wMel than wBm. Genes contributing to DNA metabolism, cofactor biosynthesis, and secretion were positively selected in both lineages. In wMel there was a greater emphasis on DNA repair, cell division, protein stability, and cell envelope synthesis.<br><br>CONCLUSION: Secretion pathways and outer surface protein encoding genes are highly affected by selection in keeping with host:parasite theory. If evidence of selection on various cofactor molecules reflects possible provisioning, then both insect as well as nematode Wolbachia may be providing substances to hosts. Selection on cell envelope synthesis, DNA replication and repair machinery, heat shock, and two component switching suggest strategies insect Wolbachia may employ to cope with diverse host and intra-host environments.}, }
@article {pmid17470061, year = {2007}, author = {Scharff, LB and Koop, HU}, title = {Targeted inactivation of the tobacco plastome origins of replication A and B.}, journal = {The Plant journal : for cell and molecular biology}, volume = {50}, number = {5}, pages = {782-794}, doi = {10.1111/j.1365-313X.2007.03087.x}, pmid = {17470061}, issn = {0960-7412}, mesh = {Cell Cycle Proteins/*genetics ; DNA Replication ; DNA, Plant/genetics ; *Mutation ; Polymerase Chain Reaction ; Replication Origin/*genetics ; Reproduction/*genetics ; *Sequence Deletion ; Tobacco/genetics/growth &amp; development/*physiology ; }, abstract = {According to the Kolodner and Tewari model [Kolodner, R.D. and Tewari, K.K. (1975) Nature, 256, 708.], plastid DNA replication involves displacement-loop and rolling-circle modes of replication, which are initiated on a pair of origins of replication (ori). In accordance with the model, such a pair of oris -oriA and oriB- was described in Nicotiana tabacum [Kunnimalaiyaan, M. and Nielsen B.L. (1997b) Nucl. Acids Res. 25, 3681.]. However, as reported previously, both copies of oriA can be deleted without abolishing replication. Deletion of both oriBs was not found [Mühlbauer, S.K. et al. (2002) Plant J. 32, 175.]. Here we describe new ori inactivation lines, in which one oriB is deleted and the other copy is strongly mutated. In addition, lines oriA and oriB were deleted from the same inverted repeat. In contrast to the expectations of the model, neither oriA nor oriB is essential. Some of the deletions led to reduced growth of plants and reduced plastid DNA copy number in later stages of leaf development. The gross structure of plastid DNA was unchanged; however, the location of the ends of branched plastid DNA complexes was different in the inactivation mutants. Taken together, the results indicate that there are additional mechanisms of plastid DNA replication and/or additional origins of replication. These mechanisms seem to be different from those found in eubacteria, which, according to the endosymbiont theory, are the progenitors of plastids.}, }
@article {pmid17468963, year = {2007}, author = {Shinzato, N and Watanabe, I and Meng, XY and Sekiguchi, Y and Tamaki, H and Matsui, T and Kamagata, Y}, title = {Phylogenetic analysis and fluorescence in situ hybridization detection of archaeal and bacterial endosymbionts in the anaerobic ciliate trimyema compressum.}, journal = {Microbial ecology}, volume = {54}, number = {4}, pages = {627-636}, pmid = {17468963}, issn = {0095-3628}, mesh = {Anaerobiosis ; Animals ; Bacteria/classification/genetics/growth &amp; development/*isolation &amp; purification ; Ciliophora/growth &amp; development/*microbiology ; DNA, Archaeal/analysis/isolation &amp; purification ; DNA, Bacterial/analysis/isolation &amp; purification ; In Situ Hybridization, Fluorescence ; Methanobrevibacter/classification/genetics/growth &amp; development/*isolation &amp; purification ; Molecular Sequence Data ; *Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The anaerobic free-living ciliate, Trimyema compressum, is known to harbor both methanogenic archaeal and bacterial symbionts in the cytoplasm. To clarify their phylogenetic belongings, a full-cycle rRNA approach was applied to this symbiosis. Phylogenetic analysis showed that the methanogenic symbiont was related to Methanobrevibacter arboriphilicus, which was distantly related to symbionts found in other Trimyema species. This result suggested that Trimyema species do not require very specific methanogenic symbionts, and symbiont replacement could have occurred in the history of Trimyema species. On the other hand, the bacterial symbiont was located near the lineage of the family Syntrophomonadaceae in the phylum Firmicutes. The sequence similarity between the bacterial symbiont and the nearest species was 85%, indicating that bacterial symbionts may be specific to the Trimyema species. The elimination of bacterial symbionts from the ciliate cell by antibiotic treatment resulted in considerably decreased host growth. However, it was not restored by stigmasterol addition (<2 microg ml(-1)), which was different from the previous report that showed that the symbiont-free strain required exogenous sterols for growth. In addition, the decline of host growth was not accompanied by host metabolism shift toward the formation of more reduced products, which suggested that the contribution of bacterial symbionts to the host ciliate was not a dispose of excessive reducing equivalent arising from the host's fermentative metabolism as methanogenic symbionts do. This study showed that bacterial symbionts make a significant contribution to the host ciliate by an unknown function and suggested that interactions between bacterial symbionts and T. compressum are more complicated than hitherto proposed.}, }
@article {pmid17466324, year = {2007}, author = {An Nguyen, TT and Michaud, D and Cloutier, C}, title = {Proteomic profiling of aphid Macrosiphum euphorbiae responses to host-plant-mediated stress induced by defoliation and water deficit.}, journal = {Journal of insect physiology}, volume = {53}, number = {6}, pages = {601-611}, doi = {10.1016/j.jinsphys.2007.02.018}, pmid = {17466324}, issn = {0022-1910}, mesh = {Animals ; Aphids/growth &amp; development/*metabolism ; Coleoptera/growth &amp; development ; Discriminant Analysis ; Electrophoresis, Gel, Two-Dimensional ; Insect Proteins/analysis/*metabolism ; Plant Diseases/*parasitology ; Proteomics/*methods ; Solanum tuberosum ; Water/metabolism ; }, abstract = {Abiotic and biotic host-plant stress, such as desiccation and herbivory, may strongly affect sap-sucking insects such as aphids via changes in plant chemicals of insect nutritional or plant defensive value. Here, we examined (i) water deprivation and (ii) defoliation by the beetle Leptinotarsa decemlineata as stresses indirectly affecting the aphid Macrosiphum euphorbiae via its host plant Solanum tuberosum. For plant-induced stress, aphids were reared on healthy vs. continuously stressed potato for 14 days (no watering; defoliation maintained at approximately 40%). Aphid performance under stress was correlated with metabolic responses monitored by profiling of the aphid proteome. M. euphorbiae was strongly affected by water stress, as adult survival, total aphid number and biomass were reduced by 67%, 64%, and 79%, respectively. Aphids performed normally on defoliated potato, indicating that they were unaffected or able to compensate any stress induced by plant defoliation. Stressed aphid proteomes revealed 419-453 protein spots, including 27 that were modulated specifically or jointly under each kind of host-plant stress. Reduced aphid fitness on water-stressed plants mostly correlated with modulation of proteins involved in energy metabolism, apparently to conserve energy in order to prioritize survival. Despite normal performance, several aphid proteins that are known to be implicated in cell communication were modulated on defoliated plants, possibly suggesting modified aphid behaviour. The GroEL protein (or symbionin) of the endosymbiont Buchnera aphidicola was predominant under all conditions in M. euphorbiae. Its expression level was not significantly affected by aphid host-plant stresses, which is consistent with the high priority of symbiosis in stressed aphids.}, }
@article {pmid17462896, year = {2007}, author = {Patron, NJ and Inagaki, Y and Keeling, PJ}, title = {Multiple gene phylogenies support the monophyly of cryptomonad and haptophyte host lineages.}, journal = {Current biology : CB}, volume = {17}, number = {10}, pages = {887-891}, doi = {10.1016/j.cub.2007.03.069}, pmid = {17462896}, issn = {0960-9822}, mesh = {Algal Proteins/*classification/genetics ; Cryptophyta/classification/genetics ; Eukaryota/*classification/genetics ; Expressed Sequence Tags ; Molecular Sequence Data ; *Phylogeny ; Plastids/genetics ; Rhodophyta/genetics ; Symbiosis ; }, abstract = {Cryptomonad algae acquired their plastids by the secondary endosymbiotic uptake of a eukaryotic red alga. Several other algal lineages acquired plastids through such an event [1], but cryptomonads are distinguished by the retention of a relic red algal nucleus, the nucleomorph [2]. The nucleomorph (and its absence in other lineages) can reveal a great deal about the process and history of endosymbiosis, but only if we know the relationship between cryptomonads and other algae, and this has been controversial. Several recent analyses have suggested a relationship between plastids of cryptomonads and some or all other red alga-containing lineages [3-6], but we must also know whether host nuclear genes mirror this relationship to determine the number of endosymbiotic events, and this has not been demonstrated. We have carried out an expressed sequence tag (EST) survey of the cryptomonad Guillardia theta. Phylogenetic analyses of 102 orthologous nucleus-encoded proteins (18,425 amino acid alignment positions) show a robust sister-group relationship between cryptomonads and the haptophyte algae, which also have a red secondary plastid. This relationship demonstrates that loss of nucleomorphs must have taken place in haptophytes independently of any other red alga-containing lineages and that the ancestor of both already contained a red algal endosymbiont.}, }
@article {pmid17447014, year = {2007}, author = {Novelli, VM and Freitas-Astúa, J and Arrivabem, F and Locali-Fabris, EC and Hilf, ME and Gottwald, TR and Machado, MA}, title = {Effects of temperature, storage period and the number of individuals on the detection of the false spider mite Cardinium endosymbiont.}, journal = {Experimental &amp; applied acarology}, volume = {42}, number = {1}, pages = {17-21}, pmid = {17447014}, issn = {0168-8162}, mesh = {Animals ; Cytophagaceae/*genetics ; DNA, Ribosomal/*analysis ; Mites/*microbiology ; Polymerase Chain Reaction ; Sample Size ; Symbiosis ; *Temperature ; Time Factors ; }, abstract = {Cardinium have been found as endosymbionts of Brevipalpus phoenicis, the mite vector of the Citrus leprosis virus. With the long-term objective being to understand the mechanisms of plant-virus-vector interactions, we evaluated the different storage conditions and periods, as well as the number of mites needed for PCR-amplification of such endosymbionts, making it possible to collect mites in different geographical regions without prolonged storage compromising subsequent analyses.}, }
@article {pmid17443956, year = {2007}, author = {Jaenike, J and Polak, M and Fiskin, A and Helou, M and Minhas, M}, title = {Interspecific transmission of endosymbiotic Spiroplasma by mites.}, journal = {Biology letters}, volume = {3}, number = {1}, pages = {23-25}, pmid = {17443956}, issn = {1744-9561}, mesh = {Animals ; Arachnid Vectors/*physiology ; Drosophila/*microbiology/parasitology ; Female ; Host-Parasite Interactions/physiology ; Male ; Mites/*microbiology/physiology ; Spiroplasma/*physiology ; }, abstract = {The occurrence of closely related strains of maternally transmitted endosymbionts in distantly related insect species indicates that these infections can colonize new host species by lateral transfer, although the mechanisms by which this occurs are unknown. We investigated whether ectoparasitic mites, which feed on insect haemolymph, can serve as interspecific vectors of Spiroplasma poulsonii, a male-killing endosymbiont of Drosophila. Using Spiroplasma-specific primers for PCR, we found that mites can pick up Spiroplasma from infected Drosophila nebulosa females and subsequently transfer the infection to Drosophila willistoni. Some of the progeny of the recipient D. willistoni were infected, indicating successful maternal transmission of the Spiroplasma within the new host species. However, the transmission rate of the infection from recipient flies to their offspring was low, perhaps due to low Spiroplasma density in the recipient flies.}, }
@article {pmid17429433, year = {2007}, author = {de Duve, C}, title = {The origin of eukaryotes: a reappraisal.}, journal = {Nature reviews. Genetics}, volume = {8}, number = {5}, pages = {395-403}, doi = {10.1038/nrg2071}, pmid = {17429433}, issn = {1471-0056}, mesh = {Animals ; *Biological Evolution ; Cell Membrane/physiology ; Cell Nucleus/physiology ; Chimerism ; Cytoskeleton/physiology ; Eukaryotic Cells/*physiology ; Humans ; Hydrogen/metabolism ; Mitochondria/metabolism/physiology ; Models, Biological ; Time Factors ; }, abstract = {Ever since the elucidation of the main structural and functional features of eukaryotic cells and subsequent discovery of the endosymbiotic origin of mitochondria and plastids, two opposing hypotheses have been proposed to account for the origin of eukaryotic cells. One hypothesis postulates that the main features of these cells, including their ability to capture food by endocytosis and to digest it intracellularly, were developed first, and later had a key role in the adoption of endosymbionts; the other proposes that the transformation was triggered by an interaction between two typical prokaryotic cells, one of which became the host and the other the endosymbiont. Re-examination of this question in the light of cell-biological and phylogenetic data leads to the conclusion that the first model is more likely to be the correct one.}, }
@article {pmid17428539, year = {2007}, author = {Mattila, JT and Munderloh, UG and Kurtti, TJ}, title = {Rickettsia peacockii, an endosymbiont of Dermacentor andersoni, does not elicit or inhibit humoral immune responses from immunocompetent D. andersoni or Ixodes scapularis cell lines.}, journal = {Developmental and comparative immunology}, volume = {31}, number = {11}, pages = {1095-1106}, pmid = {17428539}, issn = {0145-305X}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI049424-05/AI/NIAID NIH HHS/United States ; 5R01 AI049424/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Cell Line ; Defensins/chemistry/immunology/*metabolism ; Dermacentor/*immunology/metabolism/microbiology ; Ixodes/*immunology/metabolism/microbiology ; Molecular Sequence Data ; Muramidase/immunology/*metabolism ; Rickettsia/*immunology/physiology ; Sequence Alignment ; Symbiosis ; }, abstract = {Ixodes scapularis and Dermacentor andersoni cell lines were stimulated with heat-killed Escherichia coli and Micrococcus luteus to investigate whether infection by Rickettsia peacockii, an endosymbiont of D. andersoni, modifies humoral immune responses. Radial diffusion assays, western blotting, flow cytometry, and quantitative reverse-transcription PCR were used to determine if expression of bacteriolytic peptides, including lysozyme and defensin, was upregulated by bacterial stimulation or infection with R. peacockii. The I. scapularis line IDE12 upregulated expression of lysozyme and defensin following stimulation. The D. andersoni cell line DAE15 also expressed defensin and lysozyme, but only lysozyme was upregulated by bacterial stimulation. R. peacockii infection alone, or in cells stimulated with bacteria, did not modify defensin or lysozyme expression in either cell line. These results suggest tick endosymbionts may avoid recognition by the tick immune system, and infection may not affect humoral immune responses to bacteria not normally associated with ticks.}, }
@article {pmid17416546, year = {2007}, author = {Larkum, AW and Lockhart, PJ and Howe, CJ}, title = {Shopping for plastids.}, journal = {Trends in plant science}, volume = {12}, number = {5}, pages = {189-195}, doi = {10.1016/j.tplants.2007.03.011}, pmid = {17416546}, issn = {1360-1385}, mesh = {Animals ; *Biological Evolution ; Diatoms/*microbiology ; Eukaryota/*microbiology ; Plastids/*physiology ; Symbiosis/*physiology ; }, abstract = {Recent suggestions that endosymbionts in a diatom and an amoeba represent independent origins of plastids from those in plants and algae raise again the question of how many times plastids have evolved. In this Opinion article, we review the evidence for a single origin or multiple origins of primary plastids. Although the data are widely taken as supporting a single origin, we stress the assumptions underlying that view, and argue for a more cautious interpretation. We also suggest that the implicit view of plastids being acquired from single ancestors at a single point (or points) in time is an over-simplification.}, }
@article {pmid17412585, year = {2007}, author = {Partida-Martinez, LP and Monajembashi, S and Greulich, KO and Hertweck, C}, title = {Endosymbiont-dependent host reproduction maintains bacterial-fungal mutualism.}, journal = {Current biology : CB}, volume = {17}, number = {9}, pages = {773-777}, doi = {10.1016/j.cub.2007.03.039}, pmid = {17412585}, issn = {0960-9822}, mesh = {*Biological Evolution ; Burkholderia/*physiology ; Green Fluorescent Proteins/metabolism ; Microscopy, Confocal ; Mycotoxins/biosynthesis ; Reproduction/physiology ; Rhizopus/*physiology ; Spores, Fungal/growth &amp; development ; *Symbiosis ; }, abstract = {Bacterial endosymbionts play essential roles for many organisms, and thus specialized mechanisms have evolved during evolution that guarantee the persistence of the symbiosis during or after host reproduction. The rice seedling blight fungus Rhizopus microsporus represents a unique example of a mutualistic life form in which a fungus harbors endobacteria (Burkholderia sp.) for the production of a phytotoxin. Here we report the unexpected observation that in the absence of endosymbionts, the host is not capable of vegetative reproduction. Formation of sporangia and spores is restored only upon reintroduction of endobacteria. To monitor this process, we succeeded in GFP labeling cultured endosymbionts. We also established a laserbeam transformation technique for the first controlled introduction of bacteria into fungi to observe their migration to the tips of the aseptate hyphae. The persistence of this fungal-bacterial mutualism through symbiont-dependent sporulation is intriguing from an evolutionary point of view and implies that the symbiont produces factors that are essential for the fungal life cycle. Reproduction of the host has become totally dependent on endofungal bacteria, which in return provide a highly potent toxin for defending the habitat and accessing nutrients from decaying plants. This scenario clearly highlights the significance for a controlled maintenance of this fungal-bacterial symbiotic relationship.}, }
@article {pmid17403155, year = {2007}, author = {Imanian, B and Carpenter, KJ and Keeling, PJ}, title = {Mitochondrial genome of a tertiary endosymbiont retains genes for electron transport proteins.}, journal = {The Journal of eukaryotic microbiology}, volume = {54}, number = {2}, pages = {146-153}, doi = {10.1111/j.1550-7408.2007.00245.x}, pmid = {17403155}, issn = {1066-5234}, mesh = {Animals ; Cytochromes b/genetics ; DNA, Mitochondrial/*genetics ; DNA, Protozoan/chemistry/genetics ; Dinoflagellida/classification/*genetics/*ultrastructure ; Electron Transport/genetics ; Electron Transport Complex IV/genetics ; Microscopy, Electron, Transmission ; Mitochondrial Proteins/*genetics ; Molecular Sequence Data ; Phylogeny ; Protozoan Proteins/*genetics ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {Mitochondria and plastids originated through endosymbiosis, and subsequently became reduced and integrated with the host in similar ways. Plastids spread between lineages through further secondary or even tertiary endosymbioses, but mitochondria appear to have originated once and have not spread between lineages. Mitochondria are also generally lost in secondary and tertiary endosymbionts, with the single exception of the diatom tertiary endosymbiont of dinoflagellates like Kryptoperidinium foliaceum, where both host and endosymbiont are reported to contain mitochondria. Here we describe the first mitochondrial genes from this system: cytochrome c oxidase 1 (cox1), cytochrome oxidase 3 (cox3), and cytochrome b (cob). Phylogenetic analyses demonstrated that all characterized genes were derived from the pennate diatom endosymbiont, and not the host. We also demonstrated that all three genes are expressed, that cox1 contains spliced group II introns, and that cob and cox3 form an operon, all like their diatom relatives. The endosymbiont mitochondria not only retain a genome, but also express their genes, and are therefore likely involved in electron transport. Ultrastructural examination confirmed the endosymbiont mitochondria retain normal tubular cristae. Overall, these data suggest the endosymbiont mitochondria have not reduced at the genomic or functional level.}, }
@article {pmid17400002, year = {2007}, author = {Gruwell, ME and Morse, GE and Normark, BB}, title = {Phylogenetic congruence of armored scale insects (Hemiptera: Diaspididae) and their primary endosymbionts from the phylum Bacteroidetes.}, journal = {Molecular phylogenetics and evolution}, volume = {44}, number = {1}, pages = {267-280}, doi = {10.1016/j.ympev.2007.01.014}, pmid = {17400002}, issn = {1055-7903}, mesh = {Animals ; Bacteroidetes/classification/*genetics/growth &amp; development ; DNA, Ribosomal/*genetics ; Hemiptera/classification/*genetics/microbiology ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {Insects in the sap-sucking hemipteran suborder Sternorrhyncha typically harbor maternally transmitted bacteria housed in a specialized organ, the bacteriome. In three of the four superfamilies of Sternorrhyncha (Aphidoidea, Aleyrodoidea, Psylloidea), the bacteriome-associated (primary) bacterial lineage is from the class Gammaproteobacteria (phylum Proteobacteria). The fourth superfamily, Coccoidea (scale insects), has a diverse array of bacterial endosymbionts whose affinities are largely unexplored. We have amplified fragments of two bacterial ribosomal genes from each of 68 species of armored scale insects (Diaspididae). In spite of initially using primers designed for Gammaproteobacteria, we consistently amplified sequences from a different bacterial phylum: Bacteroidetes. We use these sequences (16S and 23S, 2105 total base pairs), along with previously published sequences from the armored scale hosts (elongation factor 1alpha and 28S rDNA) to investigate phylogenetic congruence between the two clades. The Bayesian tree for the bacteria is roughly congruent with that of the hosts, with 67% of nodes identical. Partition homogeneity tests found no significant difference between the host and bacterial data sets. Of thirteen Shimodaira-Hasegawa tests, comparing the original Bayesian bacterial tree to bacterial trees with incongruent clades forced to match the host tree, 12 found no significant difference. A significant difference in topology was found only when the entire host tree was compared with the entire bacterial tree. For the bacterial data set, the treelengths of the most parsimonious host trees are only 1.8-2.4% longer than that of the most parsimonious bacterial trees. The high level of congruence between the topologies indicates that these Bacteroidetes are the primary endosymbionts of armored scale insects. To investigate the phylogenetic affinities of these endosymbionts, we aligned some of their 16S rDNA sequences with other known Bacteroidetes endosymbionts and with other similar sequences identified by BLAST searches. Although the endosymbionts of armored scales are only distantly related to the endosymbionts of the other sternorrhynchan insects, they are closely related to bacteria associated with eriococcid and margarodid scale insects, to cockroach and auchenorrynchan endosymbionts (Blattabacterium and Sulcia), and to male-killing endosymbionts of ladybird beetles. We propose the name "Candidatus Uzinura diaspidicola" for the primary endosymbionts of armored scale insects.}, }
@article {pmid17391411, year = {2007}, author = {Noda, S and Kitade, O and Inoue, T and Kawai, M and Kanuka, M and Hiroshima, K and Hongoh, Y and Constantino, R and Uys, V and Zhong, J and Kudo, T and Ohkuma, M}, title = {Cospeciation in the triplex symbiosis of termite gut protists (Pseudotrichonympha spp.), their hosts, and their bacterial endosymbionts.}, journal = {Molecular ecology}, volume = {16}, number = {6}, pages = {1257-1266}, doi = {10.1111/j.1365-294X.2006.03219.x}, pmid = {17391411}, issn = {0962-1083}, mesh = {Animals ; Bacteroidaceae/*genetics ; Base Sequence ; Bayes Theorem ; DNA Primers ; DNA, Mitochondrial/genetics ; Digestive System/parasitology ; Eukaryota/*genetics/*microbiology ; *Genetic Speciation ; In Situ Hybridization, Fluorescence ; Isoptera/*genetics/*parasitology ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {A number of cophylogenetic relationships between two organisms namely a host and a symbiont or parasite have been studied to date; however, organismal interactions in nature usually involve multiple members. Here, we investigated the cospeciation of a triplex symbiotic system comprising a hierarchy of three organisms -- termites of the family Rhinotermitidae, cellulolytic protists of the genus Pseudotrichonympha in the guts of these termites, and intracellular bacterial symbionts of the protists. The molecular phylogeny was inferred based on two mitochondrial genes for the termites and nuclear small-subunit rRNA genes for the protists and their endosymbionts, and these were compared. Although intestinal microorganisms are generally considered to have looser associations with the host than intracellular symbionts, the Pseudotrichonympha protists showed almost complete codivergence with the host termites, probably due to strict transmissions by proctodeal trophallaxis or coprophagy based on the social behaviour of the termites. Except for one case, the endosymbiotic bacteria of the protists formed a monophyletic lineage in the order Bacteroidales, and the branching pattern was almost identical to those of the protists and the termites. However, some non-codivergent evolutionary events were evident. The members of this triplex symbiotic system appear to have cospeciated during their evolution with minor exceptions; the evolutionary relationships were probably established by termite sociality and the complex microbial community in the gut.}, }
@article {pmid17391400, year = {2007}, author = {van Oppen, MJ}, title = {Perspective.}, journal = {Molecular ecology}, volume = {16}, number = {6}, pages = {1125-1126}, doi = {10.1111/j.1365-294X.2007.03254.x}, pmid = {17391400}, issn = {0962-1083}, mesh = {Animals ; Anthozoa/*microbiology/physiology ; *Ecosystem ; Eukaryota/*genetics/physiology ; *Genetic Variation ; *Greenhouse Effect ; Oceans and Seas ; *Symbiosis ; }, abstract = {Reef corals are especially sensitive to environmental change since their survival is dependent on a delicate balance between the coral host and its algal endosymbiont. Predicting the responses of reef ecosystems to global climate change requires a detailed understanding of the diversity of both partners in this symbiosis. The current perception of coral-inhabiting symbiont diversity at nuclear ribosomal DNA is shown in this issue of Molecular Ecology to be a significant underestimate of the wide diversity that in fact exists. Apprill &amp; Gates (2007) reveal eight- to tenfold greater diversity than previous methods had identified. The authors underline the importance of detailed knowledge of such diversity if we are to predict, or possibly manage, the acclimatization and adaptation of reef corals to climatic change.}, }
@article {pmid17391329, year = {2007}, author = {Ohkuma, M and Sato, T and Noda, S and Ui, S and Kudo, T and Hongoh, Y}, title = {The candidate phylum 'Termite Group 1' of bacteria: phylogenetic diversity, distribution, and endosymbiont members of various gut flagellated protists.}, journal = {FEMS microbiology ecology}, volume = {60}, number = {3}, pages = {467-476}, doi = {10.1111/j.1574-6941.2007.00311.x}, pmid = {17391329}, issn = {0168-6496}, mesh = {Animals ; Bacteria/*classification/genetics ; Bacterial Physiological Phenomena ; Biodiversity ; Cattle ; Cockroaches/microbiology/parasitology ; DNA, Bacterial ; Eukaryota/*microbiology/physiology ; Gastrointestinal Tract/microbiology/parasitology ; Genes, rRNA ; Isoptera/*microbiology/parasitology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rumen/microbiology/parasitology ; Symbiosis ; }, abstract = {The candidate phylum 'Termite Group 1' (TG1) of bacteria, which is abundant in termite guts but has no culturable representative, was investigated with respect to the in situ localization, distribution, and diversity. Based on the 16S rRNA gene sequence analyses and FISH in termite guts, a number of lineages of TG1 members were identified as endosymbionts of a variety of gut flagellated protists from the orders Trichonymphida, Cristamonadida, and Oxymonadida that are mostly unique to termites. However, the survey in various environments using specific PCR primers revealed that TG1 members were also present in termites, a cockroach, and the bovine rumen that typically lack these protist orders. Most of the TG1 members from gut flagellates, termites, cockroaches, and the rumen formed a monophyletic subcluster that showed a shallow branching pattern in the phylogenetic tree, suggesting their recent diversification. Although endosymbionts of the same protist genera tended to be closely related, the endosymbiont lineages were often independent of the higher level classifications of their host protist and were dispersed in the phylogenetic tree. It appears that their cospeciation is not the sole rule for the diversification of TG1 members of endosymbionts.}, }
@article {pmid17380892, year = {2007}, author = {Emel'ianov, VV}, title = {[Suggested mitochondrial ancestry of non-mitochondrial ATP/ADP].}, journal = {Molekuliarnaia biologiia}, volume = {41}, number = {1}, pages = {59-70}, pmid = {17380892}, issn = {0026-8984}, mesh = {Alphaproteobacteria/enzymology/genetics ; Animals ; Bacterial Proteins/genetics ; Eukaryota/genetics ; *Evolution, Molecular ; Mitochondria/*genetics ; Mitochondrial ADP, ATP Translocases/*genetics ; *Phylogeny ; Plants/genetics ; Plastids/genetics ; Symbiosis/genetics ; }, abstract = {One of the major evolutionary events that transformed endosymbiotic bacterium into mitochondrion was an acquisition of ATP/ADP carrier in order to supply the host with respiration-derived ATP. Along with mitochondrial carrier, unrelated carrier is known which is characteristic of intracellular chlamydiae, plastids, parasitic intracellular eukaryote Encephalitozoon cuniculi, and the genus Rickettsia of obligate endosymbiotic alpha-Proteobacteria. This non-mitochondrial ATP/ADP carrier was recently described in rickettsia-like endosymbionts - a group of obligate intracellular bacteria, classified with the order Rickettsiales, which have diverged after free-living alpha-Proteobacteria but before sister groups of the Rickettsiaceae assemblage (true rickettsiae) and mitochondria. Published controversial phylogenetic data on the non-mitochondrial carrier were reanalysed in the present work using both DNA and protein sequences, and various methods including Bayesian analysis. The data presented are consistent with classic endosymbiont theory for the origin of mitochondria and also suggest that even last but one common ancestor of rickettsiae and organelles may have been an endosymbiotic bacterium in which ATP/ADP carrier has first originated.}, }
@article {pmid17378431, year = {2007}, author = {Perrine-Walker, FM and Gartner, E and Hocart, CH and Becker, A and Rolfe, BG}, title = {Rhizobium-initiated rice growth inhibition caused by nitric oxide accumulation.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {20}, number = {3}, pages = {283-292}, doi = {10.1094/MPMI-20-3-0283}, pmid = {17378431}, issn = {0894-0282}, mesh = {Models, Biological ; Nitrate Reductase/genetics/metabolism ; Nitrates/metabolism ; Nitric Oxide/*metabolism ; Nitrogen Fixation/genetics/physiology ; Oryza/growth &amp; development/*metabolism/microbiology ; Plant Roots/growth &amp; development/*metabolism/microbiology ; Rhizobium/genetics/*growth &amp; development/metabolism ; Seedlings/growth &amp; development/metabolism/microbiology ; }, abstract = {Isolates of Rhizobium leguminosarum bv. trifolii (the clover root-nodule endosymbiont) from the Nile River delta have been found to infect rice roots and colonize the intercellular spaces of the rice roots. Some of these isolates inhibit rice seedling growth but one in particular, R4, has been found in rice roots which develop and grow normally. We present evidence that the induced growth inhibition is due to a toxic accumulation of nitric oxide (NO), from the reduction of nitrate, and suggest that the reason that R4 does not inhibit rice root growth is because it is capable of completing the reduction of NO through to nitrogen gas. Thus, strain R4 is a candidate for engineering into a future biological nitrogen fixation system within these roots.}, }
@article {pmid17376757, year = {2007}, author = {Lo, N and Beninati, T and Stone, F and Walker, J and Sacchi, L}, title = {Cockroaches that lack Blattabacterium endosymbionts: the phylogenetically divergent genus Nocticola.}, journal = {Biology letters}, volume = {3}, number = {3}, pages = {327-330}, pmid = {17376757}, issn = {1744-9561}, mesh = {Animals ; Bacteroidetes/genetics ; Base Sequence ; Bayes Theorem ; Cockroaches/classification/*genetics/*microbiology ; DNA, Mitochondrial/genetics ; Histones/genetics ; Models, Genetic ; Molecular Sequence Data ; Northern Territory ; *Phylogeny ; Queensland ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; }, abstract = {Phylogenetic relationships among termites, mantids and the five traditionally recognized cockroach families have been the subject of several studies during the last half-century. One cockroach lineage that has remained notably absent from such studies is the Nocticolidae. This group of small, elusive surface- and cave-dwelling species from the Old World Tropics has been proposed to represent an additional family. Using molecular sequences, we performed an initial phylogenetic examination of Nocticola spp. The hypothesis that they are phylogenetically divergent was confirmed from the analyses of three genes and a combined dataset. To supplement our phylogenetic analyses, we attempted to amplify 16S rRNA from the obligate mutualistic endosymbiont Blattabacterium cuenoti, present in all cockroaches studied to date. Unexpectedly, amplification was unsuccessful in all Nocticola spp. examined. This result was confirmed by microscopic examinations of fat body tissue. These Nocticola spp. are the first cockroaches found to be uninfected by B. cuenoti, which raise questions about when the bacterium first infected cockroaches.}, }
@article {pmid17374973, year = {2007}, author = {Yu, HS and Jeong, HJ and Hong, YC and Seol, SY and Chung, DI and Kong, HH}, title = {Natural occurrence of Mycobacterium as an endosymbiont of Acanthamoeba isolated from a contact lens storage case.}, journal = {The Korean journal of parasitology}, volume = {45}, number = {1}, pages = {11-18}, pmid = {17374973}, issn = {0023-4001}, mesh = {Acanthamoeba/genetics/isolation &amp; purification/*microbiology ; Animals ; Base Sequence ; Contact Lens Solutions ; *Contact Lenses ; DNA, Mitochondrial/genetics ; Microscopy, Electron, Transmission/methods ; Mycobacterium/genetics/*isolation &amp; purification ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Symbiosis ; }, abstract = {Recent in vitro studies have revealed that a certain Mycobacterium can survive and multiply within free-living amoebae. It is believed that protozoans function as host cells for the intracellular replication and evasion of Mycobacterium spp. under harmful conditions. In this study, we describe the isolation and characterization of a bacterium naturally observed within an amoeba isolate acquired from a contact lens storage case. The bacterium multiplied within Acanthamoeba, but exerted no cytopathic effects on the amoeba during a 6-year amoebic culture. Transmission electron microscopy showed that the bacteria were randomly distributed within the cytoplasm of trophozoites and cysts of Acanthamoeba. On the basis of the results of 18S rRNA gene analysis, the amoeba was identified as A. lugdunensis. A 16S rRNA gene analysis placed this bacterium within the genus Mycobacterium. The bacterium evidenced positive reactivity for acid-fast and fluorescent acid-fast stains. The bacterium was capable of growth on the Middlebrook 7H11-Mycobacterium-specific agar. The identification and characterization of bacterial endosymbionts of free-living protozoa bears significant implications for our understanding of the ecology and the identification of other atypical mycobacterial pathogens.}, }
@article {pmid17374972, year = {2007}, author = {Xuan, YH and Yu, HS and Jeong, HJ and Seol, SY and Chung, DI and Kong, HH}, title = {Molecular characterization of bacterial endosymbionts of Acanthamoeba isolates from infected corneas of Korean patients.}, journal = {The Korean journal of parasitology}, volume = {45}, number = {1}, pages = {1-9}, pmid = {17374972}, issn = {0023-4001}, mesh = {Acanthamoeba/genetics/isolation &amp; purification/*microbiology ; Acanthamoeba Keratitis/*microbiology/*parasitology ; Animals ; Bacteria/*genetics/isolation &amp; purification ; Base Sequence ; Cornea/microbiology/*parasitology ; DNA, Mitochondrial/genetics ; Humans ; Korea ; Microscopy, Electron, Transmission/methods ; Oxazines/metabolism ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Symbiosis ; }, abstract = {The endosymbionts of 4 strains of Acanthamoeba (KA/E9, KA/E21, KA/E22, and KA/E23) isolated from the infected corneas of Korean patients were characterized via orcein stain, transmission electron microscopic examination, and 16S rDNA sequence analysis. Double membrane-bound, rod-shaped endosymbionts were distributed randomly throughout both the trophozoites and cysts of each of Acanthamoeba isolates. The endosymbionts of KA/E9, KA/E22, and KA/E23 were surrounded by electron-translucent areas. No lacunae-like structures were observed in the endosymbionts of KA/E21, the bacterial cell walls of which were studded with host ribosomes. Comparative analyses of the 16S rDNA sequences showed that the endosymbionts of KA/E9, KA/E22 and KA/E23 were closely related to Caedibacter caryophilus, whereas the KA/E21 endosymbiont was assigned to the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum. In the 4 strains of Acanthamoeba, the hosts of the endosymbionts were identified as belonging to the Acanthamoeba castellanii complex, which corresponds to the T4 genotype. Acanthamoeba KA/E21 evidenced characteristics almost identical to those of KA/E6, with the exception of the existence of endosymbionts. The discovery of these endosymbionts from Acanthamoeba may prove essential to future studies focusing on interactions between the endosymbionts and the amoebic hosts.}, }
@article {pmid17373660, year = {2007}, author = {Archibald, JM}, title = {Nucleomorph genomes: structure, function, origin and evolution.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {29}, number = {4}, pages = {392-402}, doi = {10.1002/bies.20551}, pmid = {17373660}, issn = {0265-9247}, mesh = {Animals ; Cell Nucleus/*genetics ; *Evolution, Molecular ; Genome/*genetics ; Genomic Islands ; Models, Genetic ; }, abstract = {The cryptomonads and chlorarachniophytes are two unicellular algal lineages with complex cellular structures and fascinating evolutionary histories. Both groups acquired their photosynthetic abilities through the assimilation of eukaryotic endosymbionts. As a result, they possess two distinct cytosolic compartments and four genomes--two nuclear genomes, an endosymbiont-derived plastid genome and a mitochondrial genome derived from the host cell. Like mitochondrial and plastid genomes, the genome of the endosymbiont nucleus, or 'nucleomorph', of cryptomonad and chlorarachniophyte cells has been greatly reduced through the combined effects of gene loss and intracellular gene transfer. This article focuses on the structure, function, origin and evolution of cryptomonad and chlorarachniophyte nucleomorph genomes in light of recent comparisons of genome sequence data from both groups. It is now possible to speculate on the reasons that nucleomorphs persist in cryptomonads and chlorarachniophytes but have been lost in all other algae with plastids of secondary endosymbiotic origin.}, }
@article {pmid17366133, year = {2007}, author = {Comas, I and Moya, A and González-Candelas, F}, title = {From phylogenetics to phylogenomics: the evolutionary relationships of insect endosymbiotic gamma-Proteobacteria as a test case.}, journal = {Systematic biology}, volume = {56}, number = {1}, pages = {1-16}, doi = {10.1080/10635150601109759}, pmid = {17366133}, issn = {1063-5157}, mesh = {Animals ; Base Sequence ; Bayes Theorem ; Classification/*methods ; Gammaproteobacteria/*genetics ; Genes, Bacterial/*genetics ; Genome/*genetics ; Genomics/*methods ; Insecta/*microbiology ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; }, abstract = {The increasing availability of complete genome sequences and the development of new, faster methods for phylogenetic reconstruction allow the exploration of the set of evolutionary trees for each gene in the genome of any species. This has led to the development of new phylogenomic methods. Here, we have compared different phylogenetic and phylogenomic methods in the analysis of the monophyletic origin of insect endosymbionts from the gamma-Proteobacteria, a hotly debated issue with several recent, conflicting reports. We have obtained the phylogenetic tree for each of the 579 identified protein-coding genes in the genome of the primary endosymbiont of carpenter ants, Blochmannia floridanus, after determining their presumed orthologs in 20 additional Proteobacteria genomes. A reference phylogeny reflecting the monophyletic origin of insect endosymbionts was further confirmed with different approaches, which led us to consider it as the presumed species tree. Remarkably, only 43 individual genes produced exactly the same topology as this presumed species tree. Most discrepancies between this tree and those obtained from individual genes or by concatenation of different genes were due to the grouping of Xanthomonadales with beta-Proteobacteria and not to uncertainties over the monophyly of insect endosymbionts. As previously noted, operational genes were more prone to reject the presumed species tree than those included in information-processing categories, but caution should be exerted when selecting genes for phylogenetic inference on the basis of their functional category assignment. We have obtained strong evidence in support of the monophyletic origin of gamma-Proteobacteria insect endosymbionts by a combination of phylogenetic and phylogenomic methods. In our analysis, the use of concatenated genes has shown to be a valuable tool for analyzing primary phylogenetic signals coded in the genomes. Nevertheless, other phylogenomic methods such as supertree approaches were useful in revealing alternative phylogenetic signals and should be included in comprehensive phylogenomic studies.}, }
@article {pmid17364245, year = {2007}, author = {Pankewitz, F and Zöllmer, A and Hilker, M and Gräser, Y}, title = {Presence of Wolbachia in insect eggs containing antimicrobially active anthraquinones.}, journal = {Microbial ecology}, volume = {54}, number = {4}, pages = {713-721}, pmid = {17364245}, issn = {0095-3628}, mesh = {Animals ; Anthraquinones/analysis ; Anti-Bacterial Agents/analysis ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Coleoptera/chemistry/microbiology/physiology ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/analysis/isolation &amp; purification ; *Hemiptera/chemistry/microbiology/physiology ; Molecular Sequence Data ; Ovum/chemistry/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Wolbachia are obligatory, cytoplasmatically inherited alpha-proteobacteria, which are common endosymbionts in arthropods where they may cause reproductive abnormalities. Many insects are well known to protect themselves from deleterious microorganisms by antibiotic components. In this study, we addressed the question whether Wolbachia are able to infect insects containing antimicrobial anthraquinones and anthrones, and if so, whether these genotypes of Wolbachia comprise a monophyletic cluster within one of the known supergroups. Leaf beetles of the taxon Galerucini (Galerucinae) are known to contain 1,8-dihydroxylated anthraquinones and anthrones. Also, the scale insect Dactylopius contains an anthraquinone glycoside, carminic acid. Our analyses revealed that a representative of the Galerucini, Galeruca tanaceti and Dactylopius, are indeed infected by endosymbiotic Wolbachia bacteria. Phylogenetic analysis of the wsp and ftsZ genes of these bacteria revealed that strains in G. tanaceti cluster in supergroup A, whereas those present in Dactylopius are distinctive from each other and from those of G. tanaceti. They are clustering in supergroups A and B. Wolbachia strains present in close, but anthraquinone-free relatives of G. tanaceti were shown to belong also to supergroup A. From these results, we can conclude (1) a double infection in Dactylopius, (2) that the presence of antimicrobial compounds such as anthraquinones does not necessarily protect insects from infection by Wolbachia, and (3) that genotypes of Wolbachia-infecting anthraquinone-containing insects most likely do not comprise a unique genotype. These results show that Wolbachia bacteria might be adapted to cope even with conditions usually detrimental to other bacteria and that these adaptations are widespread among Wolbachia supergroups.}, }
@article {pmid17335290, year = {2007}, author = {Barb, AW and McClerren, AL and Snehelatha, K and Reynolds, CM and Zhou, P and Raetz, CR}, title = {Inhibition of lipid A biosynthesis as the primary mechanism of CHIR-090 antibiotic activity in Escherichia coli.}, journal = {Biochemistry}, volume = {46}, number = {12}, pages = {3793-3802}, pmid = {17335290}, issn = {0006-2960}, support = {R01 AI055588/AI/NIAID NIH HHS/United States ; T32 GM007184/GM/NIGMS NIH HHS/United States ; R01 AI055588-05A1/AI/NIAID NIH HHS/United States ; GM-51310/GM/NIGMS NIH HHS/United States ; R01 GM051310/GM/NIGMS NIH HHS/United States ; GM-07184/GM/NIGMS NIH HHS/United States ; AI-055588/AI/NIAID NIH HHS/United States ; R01 GM051310-13/GM/NIGMS NIH HHS/United States ; }, mesh = {Amidohydrolases/*antagonists &amp; inhibitors/genetics/*metabolism ; Anti-Bacterial Agents/chemistry/*pharmacology/therapeutic use ; Escherichia coli/genetics/*metabolism ; Gram-Negative Bacteria/enzymology/genetics ; Gram-Negative Bacterial Infections/drug therapy/microbiology ; Hydroxamic Acids/chemistry/*pharmacology/therapeutic use ; Kinetics ; Lipid A/antagonists &amp; inhibitors/*biosynthesis ; }, abstract = {The deacetylation of UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine (UDP-3-O-acyl-GlcNAc) by LpxC is the committed reaction of lipid A biosynthesis. CHIR-090, a novel N-aroyl-l-threonine hydroxamic acid, is a potent, slow, tight-binding inhibitor of the LpxC deacetylase from the hyperthermophile Aquifex aeolicus, and it has excellent antibiotic activity against Pseudomonas aeruginosa and Escherichia coli, as judged by disk diffusion assays. We now report that CHIR-090 is also a two-step slow, tight-binding inhibitor of E. coli LpxC with Ki = 4.0 nM, Ki* = 0.5 nM, k5 = 1.9 min-1, and k6 = 0.18 min-1. CHIR-090 at low nanomolar levels inhibits LpxC orthologues from diverse Gram-negative pathogens, including P. aeruginosa, Neisseria meningitidis, and Helicobacter pylori. In contrast, CHIR-090 is a relatively weak competitive and conventional inhibitor (lacking slow, tight-binding kinetics) of LpxC from Rhizobium leguminosarum (Ki = 340 nM), a Gram-negative plant endosymbiont that is resistant to this compound. The KM (4.8 microM) and the kcat (1.7 s-1) of R. leguminosarum LpxC with UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine as the substrate are similar to values reported for E. coli LpxC. R. leguminosarum LpxC therefore provides a useful control for validating LpxC as the primary target of CHIR-090 in vivo. An E. coli construct in which the chromosomal lpxC gene is replaced by R. leguminosarum lpxC is resistant to CHIR-090 up to 100 microg/mL, or 400 times above the minimal inhibitory concentration for wild-type E. coli. Given its relatively broad spectrum and potency against diverse Gram-negative pathogens, CHIR-090 is an excellent lead for the further development of new antibiotics targeting the lipid A pathway.}, }
@article {pmid17331615, year = {2007}, author = {Keeling, PJ}, title = {Ostreococcus tauri: seeing through the genes to the genome.}, journal = {Trends in genetics : TIG}, volume = {23}, number = {4}, pages = {151-154}, doi = {10.1016/j.tig.2007.02.008}, pmid = {17331615}, issn = {0168-9525}, mesh = {Algal Proteins/*genetics ; Chlorophyta/*genetics ; *Genome ; }, abstract = {The marine green alga Ostreococcus tauri is the smallest-known free-living eukaryote. The recent sequencing of its genome extends this distinction, because it also has one of the smallest and most compact nuclear genomes. For other highly compacted genomes (e.g. those of microsporidian parasites and relic endosymbiont nucleomorphs), compaction is associated with severe gene loss. By contrast, O. tauri has retained a large complement of genes. Studying O. tauri should shed light on forces, other than parasitism and endosymbiosis, that result in densely packed genomes.}, }
@article {pmid17317791, year = {2007}, author = {Blumer, C and Zimmermann, DR and Weilenmann, R and Vaughan, L and Pospischil, A}, title = {Chlamydiae in free-ranging and captive frogs in Switzerland.}, journal = {Veterinary pathology}, volume = {44}, number = {2}, pages = {144-150}, doi = {10.1354/vp.44-2-144}, pmid = {17317791}, issn = {0300-9858}, mesh = {Animals ; Anura/*microbiology ; Bacterial Outer Membrane Proteins/chemistry/genetics ; Chlamydia/genetics/*growth &amp; development ; Chlamydia Infections/*epidemiology/microbiology/*veterinary ; DNA, Bacterial/chemistry/genetics ; Disease Outbreaks/*veterinary ; Immunohistochemistry/veterinary ; Polymerase Chain Reaction/veterinary ; Prevalence ; RNA, Ribosomal, 16S/chemistry/genetics ; Retrospective Studies ; Sequence Analysis, DNA ; Switzerland/epidemiology ; }, abstract = {A total of 210 frog samples originating either from a mass mortality (1991/1992) or from routine postmortem investigations of the years 1990 to 2004 were examined retrospectively for a possible involvement of Chlamydiae. For a prevalence study of Chlamydia in a selected Swiss amphibian population, 403 samples from free-ranging Rana temporaria were examined. Histopathology, immunohistochemistry using a monoclonal antibody against chlamydial lipopolysaccharide, and a 16S rRNA polymerase chain reaction (PCR) followed by DNA sequencing were performed on the formalin-fixed and paraffin-embedded tissues. Using PCR, 8 of 54 (14.8%) frog samples from the mass mortality (1991/1992) were positive for Chlamydia suis S45. A control group of healthy Xenopus laevis had 3 of 38 positive samples, sequenced as C suis S45 (2/3) and an endosymbiont of Acanthamoeba species UWE1 (1/3). Chlamydophila pneumoniae TW-183 was detected from exotic frogs kept in a zoo. Of the frogs collected for the prevalence study, 6 of 238 (2.5%) tested positive, 1 each for C suis S45, Cp pneumoniae TW-183, and uncultured Chlamydiales CRG22, and the remaining 3 revealed Chlamydophila abortus S26/3. In immunohistochemistry, there were 2 positive labeling reactions, 1 in intestine and the other in the epithelium coating the body cavity, both testing positive for Cp pneumoniae TW-183 in PCR. Histologically there were no lesions recorded being characteristic for Chlamydia. Although there is a prevalence of Chlamydia in Swiss frogs, no connection to a mass mortality (1991/1992) could be established. For the first time, C suis S45 and Cp abortus S26/3 were detected in frog material.}, }
@article {pmid17317249, year = {2007}, author = {Mayfield, AB and Gates, RD}, title = {Osmoregulation in anthozoan-dinoflagellate symbiosis.}, journal = {Comparative biochemistry and physiology. Part A, Molecular &amp; integrative physiology}, volume = {147}, number = {1}, pages = {1-10}, doi = {10.1016/j.cbpa.2006.12.042}, pmid = {17317249}, issn = {1095-6433}, mesh = {Animals ; Anthozoa/*physiology ; Dinoflagellida/*physiology ; Eukaryota/physiology ; Osmotic Pressure ; *Symbiosis ; Water-Electrolyte Balance/*physiology ; }, abstract = {Endosymbiosis creates a unique osmotic circumstance. Hosts are not only responsible for balancing their internal osmolarity with respect to the external environment, but they must also maintain a compatible osmotic environment for their endosymbionts, which may themselves contribute to the net osmolarity of the host cell through molecular fluxes and/or exchange. Cnidarian hosts that harbor intracellular dinoflagellates (zooxanthellae) are excellent examples of such a symbiosis. These associations are characterized by the exchange of osmotically active compounds, but they are temporally stable under normal environmental conditions indicating that these osmotically driven exchanges are effectively and rapidly regulated. Although we have some knowledge about how asymbiotic anthozoans and algae osmoregulate, our understanding of the physiological mechanisms involved in regulating an intact anthozoan-dinoflagellate symbiosis is poor. Large-scale expulsion of endosymbiotic zooxanthellae, or bleaching, is currently considered to be one of the greatest threats to coral reefs worldwide. To date, there has been little consideration of the osmotic scenarios that occur when these symbioses are exposed to the conditions that normally elicit bleaching, such as increased seawater temperatures and UV radiation. Here we review what is known about osmoregulation and osmotic stress in anthozoans and dinoflagellates and discuss the osmotic implications of exposure to environmental stress in these globally distributed and ecologically important symbioses.}, }
@article {pmid17313660, year = {2007}, author = {Koga, R and Tsuchida, T and Sakurai, M and Fukatsu, T}, title = {Selective elimination of aphid endosymbionts: effects of antibiotic dose and host genotype, and fitness consequences.}, journal = {FEMS microbiology ecology}, volume = {60}, number = {2}, pages = {229-239}, doi = {10.1111/j.1574-6941.2007.00284.x}, pmid = {17313660}, issn = {0168-6496}, mesh = {Ampicillin/pharmacology ; Animals ; Aphids/drug effects/genetics/*microbiology ; Buchnera/drug effects/*growth &amp; development ; Dose-Response Relationship, Drug ; Genotype ; In Situ Hybridization, Fluorescence ; Rifampin/pharmacology ; Serratia/drug effects/growth &amp; development ; Symbiosis/drug effects/genetics/*physiology ; }, abstract = {Multiple endosymbionts commonly coexist in the same host insects. In order to gain an understanding of the biological roles of the individual symbionts in such complex systems, experimental techniques for enabling the selective removal of a specific symbiont from the host are of great importance. By using the pea aphid-Buchnera-Serratia endosymbiotic system as a model, the efficacy, generality, and fitness consequences of selective elimination techniques at various antibiotic doses and under a variety of host genotypes were investigated. In all the disymbiotic aphid strains examined, the facultative symbiont Serratia was selectively eliminated by ampicillin treatment in a dose-dependent manner, suggesting a generality of the elimination technique irrespective of host genotype. However, fitness consequences of the Serratia elimination differed between the aphid strains, indicating substantial effects of host genotype. In all the disymbiotic aphid strains, the obligate symbiont Buchnera was selectively eliminated by rifampicin treatment irrespective of the antibiotic dose. However, the survival and reproduction of the Buchnera-free aphids varied in a dose-dependent manner, and the dose dependence was strikingly different between the aphid genotypes. These results provide a basis for the development of new protocols for manipulating insect endosymbiotic microbiota.}, }
@article {pmid17305836, year = {2007}, author = {Kenyon, SG and Hunter, MS}, title = {Manipulation of oviposition choice of the parasitoid wasp, Encarsia pergandiella, by the endosymbiotic bacterium Cardinium.}, journal = {Journal of evolutionary biology}, volume = {20}, number = {2}, pages = {707-716}, doi = {10.1111/j.1420-9101.2006.01238.x}, pmid = {17305836}, issn = {1010-061X}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacteroidetes/drug effects/*physiology ; Behavior, Animal ; Female ; Hemiptera/parasitology ; Male ; Oviposition/drug effects/*physiology ; Rifampin/pharmacology ; Wasps/anatomy &amp; histology/*microbiology/physiology ; }, abstract = {Reproductive manipulations of hosts by maternally inherited bacterial endosymbionts often result in an increase in the proportion of infected female hosts in the population. When this involves the conversion of incipient males to genetic or functional females, it presents unique difficulties for symbionts invading hosts with sex-specific reproductive behaviours, such as the autoparasitic Encarsia pergandiella. In sexual forms of this species, female eggs are laid in whitefly nymphs and male eggs are laid in conspecific or heterospecific parasitoids developing within the whitefly cuticle. Further, eggs laid in the 'wrong' host do not ordinarily complete development. This study explored the role of a bacterial symbiont, Cardinium, in manipulating oviposition behaviour in a thelytokous population of E. pergandiella. Oviposition choice was measured by the number and location of eggs deposited by both infected and uninfected adult waSPS in arenas containing equal numbers of hosts suitable for the development of male and female waSPS. Uninfected waSPS included antibiotic-treated female waSPS and (untreated) daughters of antibiotic-treated female waSPS. The choices of waSPS in the thelytokous population treatments were compared with those of a conspecific sexual population. We found that offspring of antibiotic-cured thelytokous waSPS reverted to the behaviour of unmated sexual waSPS, laying their few eggs almost exclusively in hosts appropriate for male eggs. Infected thelytokous waSPS distributed their eggs approximately evenly between host types, much like mated sexual female waSPS. The antibiotic-treated female waSPS exhibited choices intermediate to waSPS in the other two treatments. The change in the observed behaviour appears sufficient to allow invasion and persistence of Cardinium in sexual populations. Lastly, our results suggest a reduction in host discrimination as a possible mechanism by which Cardinium influences this change.}, }
@article {pmid17305834, year = {2007}, author = {Engelstädter, J and Hammerstein, P and Hurst, GD}, title = {The evolution of endosymbiont density in doubly infected host species.}, journal = {Journal of evolutionary biology}, volume = {20}, number = {2}, pages = {685-695}, doi = {10.1111/j.1420-9101.2006.01257.x}, pmid = {17305834}, issn = {1010-061X}, mesh = {Animals ; Bacterial Physiological Phenomena ; *Biological Evolution ; Female ; Fertility/physiology ; *Infectious Disease Transmission, Vertical ; Insecta/microbiology/physiology ; Male ; *Models, Biological ; Wolbachia/physiology ; }, abstract = {Multiple infection of individual hosts with several species or strains of maternally inherited endosymbionts is commonly observed in animals, especially insects. Here, we address theoretically the effect of co-infection on the optimal density of the endosymbionts in doubly infected hosts. Our analysis is based on the observation that a maternally inherited double infection is only stable if doubly infected females produce more doubly infected daughters than singly infected or uninfected females produce daughters. We consider both a general model and a model involving two endosymbionts inducing bidirectional cytoplasmic incompatibility (CI). We demonstrate that the optimal replication rate of endosymbionts in doubly infected hosts can be expected to be similar to or below the optimal replication rate in singly infected hosts. This is in contrast to some theoretical predictions for horizontally transmitted parasites and stems from the two strains of endosymbionts having coupled fitness. We discuss our results with respect to recent empirical results on endosymbiont densities, the evolution of CI-inducing bacteria and, more generally, the evolution of cooperation through direct fitness benefits.}, }
@article {pmid17303757, year = {2007}, author = {Newton, IL and Woyke, T and Auchtung, TA and Dilly, GF and Dutton, RJ and Fisher, MC and Fontanez, KM and Lau, E and Stewart, FJ and Richardson, PM and Barry, KW and Saunders, E and Detter, JC and Wu, D and Eisen, JA and Cavanaugh, CM}, title = {The Calyptogena magnifica chemoautotrophic symbiont genome.}, journal = {Science (New York, N.Y.)}, volume = {315}, number = {5814}, pages = {998-1000}, doi = {10.1126/science.1138438}, pmid = {17303757}, issn = {1095-9203}, mesh = {Animals ; Bivalvia/*microbiology ; Carbon/metabolism ; Chemoautotrophic Growth ; Gammaproteobacteria/*genetics/isolation &amp; purification/metabolism/ultrastructure ; *Genome, Bacterial ; Molecular Sequence Data ; Photosynthesis ; *Symbiosis ; }, abstract = {Chemoautotrophic endosymbionts are the metabolic cornerstone of hydrothermal vent communities, providing invertebrate hosts with nearly all of their nutrition. The Calyptogena magnifica (Bivalvia: Vesicomyidae) symbiont, Candidatus Ruthia magnifica, is the first intracellular sulfur-oxidizing endosymbiont to have its genome sequenced, revealing a suite of metabolic capabilities. The genome encodes major chemoautotrophic pathways as well as pathways for biosynthesis of vitamins, cofactors, and all 20 amino acids required by the clam.}, }
@article {pmid17283365, year = {2007}, author = {Groth-Malonek, M and Wahrmund, U and Polsakiewicz, M and Knoop, V}, title = {Evolution of a pseudogene: exclusive survival of a functional mitochondrial nad7 gene supports Haplomitrium as the earliest liverwort lineage and proposes a secondary loss of RNA editing in Marchantiidae.}, journal = {Molecular biology and evolution}, volume = {24}, number = {4}, pages = {1068-1074}, doi = {10.1093/molbev/msm026}, pmid = {17283365}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Codon, Terminator/genetics ; DNA, Mitochondrial/chemistry/genetics ; DNA, Plant/chemistry/genetics ; Electron Transport Complex I/*genetics ; *Evolution, Molecular ; Exons/genetics ; Hepatophyta/classification/*genetics ; Mitochondrial Proteins/*genetics ; Molecular Sequence Data ; Phylogeny ; Pseudogenes/*genetics ; RNA Editing/*genetics ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; }, abstract = {Gene transfer from the mitochondrion into the nucleus is a corollary of the endosymbiont hypothesis. The frequent and independent transfer of genes for mitochondrial ribosomal proteins is well documented with many examples in angiosperms, whereas transfer of genes for components of the respiratory chain is a rarity. A notable exception is the nad7 gene, encoding subunit 7 of complex I, in the liverwort Marchantia polymorpha, which resides as a full-length, intron-carrying and transcribed, but nonspliced pseudogene in the chondriome, whereas its functional counterpart is nuclear encoded. To elucidate the patterns of pseudogene degeneration, we have investigated the mitochondrial nad7 locus in 12 other liverworts of broad phylogenetic distribution. We find that the mitochondrial nad7 gene is nonfunctional in 11 of them. However, the modes of pseudogene degeneration vary: whereas point mutations, accompanied by single-nucleotide indels, predominantly introduce stop codons into the reading frame in marchantiid liverworts, larger indels introduce frameshifts in the simple thalloid and leafy jungermanniid taxa. Most notably, however, the mitochondrial nad7 reading frame appears to be intact in the isolated liverwort genus Haplomitrium. Its functional expression is shown by cDNA analysis identifying typical RNA-editing events to reconstitute conserved codon identities and also confirming functional splicing of the 2 liverwort-specific group II introns. We interpret our results 1) to indicate the presence of a functional mitochondrial nad7 gene in the earliest land plants and strongly supporting a basal placement of Haplomitrium among the liverworts, 2) to indicate different modes of pseudogene degeneration and chondriome evolution in the later branching liverwort clades, 3) to suggest a surprisingly long maintenance of a nonfunctional gene in the presumed oldest group of land plants, and 4) to support the model of a secondary loss of RNA-editing activity in marchantiid liverworts.}, }
@article {pmid17279094, year = {2007}, author = {Wade, MJ}, title = {The co-evolutionary genetics of ecological communities.}, journal = {Nature reviews. Genetics}, volume = {8}, number = {3}, pages = {185-195}, doi = {10.1038/nrg2031}, pmid = {17279094}, issn = {1471-0056}, mesh = {*Adaptation, Physiological ; Animals ; *Ecosystem ; *Evolution, Molecular ; *Genetic Speciation ; Genomics/methods/trends ; Humans ; Plants ; }, abstract = {Co-evolution has produced many intriguing adaptations and made significant contributions to biodiversity through the co-adaptive radiations of interacting groups, such as pollinating insects and flowering plants or hosts and endosymbionts. New methods from molecular genetics and comparative genomics, in conjunction with advances in evolutionary genetic theory, are for the first time providing tools for detecting, investigating and understanding the genetic bases of the co-adaptive process and co-speciation. Advances in the emerging field of community genetics, which integrates genetics and community ecology, could revolutionize how co-evolution is studied, how genes are functionally annotated and how conservation geneticists implement preservation strategies.}, }
@article {pmid17276538, year = {2007}, author = {Jaenike, J}, title = {Fighting back against male-killers.}, journal = {Trends in ecology &amp; evolution}, volume = {22}, number = {4}, pages = {167-169}, doi = {10.1016/j.tree.2007.01.008}, pmid = {17276538}, issn = {0169-5347}, mesh = {Animals ; Butterflies/*genetics/*microbiology ; Female ; Genetic Variation ; Inbreeding ; Male ; Sex Ratio ; Wolbachia/*pathogenicity/physiology ; }, abstract = {Male-killing endosymbionts create a genetic black hole into which host nuclear genes vanish. In a recent paper, Hornett et al. transferred male-killing Wolbachia between different strains of the butterfly Hypolimnas bolina through hybridization and backcrossing. Their results provide unambiguous evidence of genetic variation for resistance to male-killers. A possible consequence of such variation is that male-killing might appear and disappear quickly on an evolutionary timescale.}, }
@article {pmid17267991, year = {2007}, author = {Svobodová, M and Zídková, L and Čepička, I and Oborník, M and Lukeš, J and Votýpka, J}, title = {Sergeia podlipaevi gen. nov., sp. nov. (Trypanosomatidae, Kinetoplastida), a parasite of biting midges (Ceratopogonidae, Diptera).}, journal = {International journal of systematic and evolutionary microbiology}, volume = {57}, number = {Pt 2}, pages = {423-432}, doi = {10.1099/ijs.0.64557-0}, pmid = {17267991}, issn = {1466-5026}, mesh = {Animals ; Ceratopogonidae/cytology/*parasitology/ultrastructure ; DNA, Kinetoplast/analysis ; DNA, Protozoan/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Gastrointestinal Tract/parasitology ; Genes, rRNA ; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)/genetics ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal, 18S/genetics ; RNA, Ribosomal, 5S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Trypanosomatina/*classification/cytology/genetics/*isolation &amp; purification ; }, abstract = {Three strains of a trypanosomatid protozoan were isolated from the midguts of two naturally infected species of biting midges [Culicoides (Oecacta) festivipennis and Culicoides (Oecacta) truncorum] and characterized by light and electron microscopy and by molecular techniques. Morphological characteristics and sequences of the 18S rRNA, 5S rRNA, spliced leader RNA and glycosomal glyceraldehyde-3-phosphate dehydrogenase genes indicate that the studied flagellates represent a novel phylogenetic lineage within the Trypanosomatidae. Based on phylogenetic analyses, the novel endosymbiont-free, monoxenous trypanosomatid was classified as Sergeia podlipaevi gen. nov., sp. nov. Interestingly, it is closely related to another trypanosomatid species that parasitizes the sand fly Lutzomyia evansi, a blood-sucking dipteran from South America. The type strain of S. podlipaevi sp. nov., ICUL/CZ/2000/CER3, was obtained from Malpighian tubes. Of 2518 females of seven species of biting midges trapped in the Czech Republic, more than 1.5 % were infected by trypanosomatid parasites. An unrelated insect species, Culicoides (Monoculicoides) nubeculosus, was experimentally infected with S. podlipaevi, demonstrating that its host range extends to different subgenera of biting midges.}, }
@article {pmid17251118, year = {2007}, author = {Esser, C and Martin, W and Dagan, T}, title = {The origin of mitochondria in light of a fluid prokaryotic chromosome model.}, journal = {Biology letters}, volume = {3}, number = {2}, pages = {180-184}, pmid = {17251118}, issn = {1744-9561}, mesh = {Alphaproteobacteria/genetics ; Bacterial Proteins/genetics ; Chromosomes/*genetics ; *Evolution, Molecular ; Genome, Bacterial/genetics ; Mitochondria/*genetics ; Phylogeny ; *Prokaryotic Cells ; RNA, Ribosomal, 16S/analysis ; }, abstract = {Biologists agree that the ancestor of mitochondria was an alpha-proteobacterium. But there is no consensus as to what constitutes an alpha-proteobacterial gene. Is it a gene found in all or several alpha-proteobacteria, or in only one? Here, we examine the proportion of alpha-proteobacterial genes in alpha-proteobacterial genomes by means of sequence comparisons. We find that each alpha-proteobacterium harbours a particular collection of genes and that, depending upon the lineage examined, between 97 and 33% are alpha-proteobacterial by the nearest-neighbour criterion. Our findings bear upon attempts to reconstruct the mitochondrial ancestor and upon inferences concerning the collection of genes that the mitochondrial ancestor possessed at the time that it became an endosymbiont.}, }
@article {pmid17241395, year = {2007}, author = {Bazzocchi, C and Comazzi, S and Santoni, R and Bandi, C and Genchi, C and Mortarino, M}, title = {Wolbachia surface protein (WSP) inhibits apoptosis in human neutrophils.}, journal = {Parasite immunology}, volume = {29}, number = {2}, pages = {73-79}, doi = {10.1111/j.1365-3024.2006.00915.x}, pmid = {17241395}, issn = {0141-9838}, mesh = {Animals ; Annexin A5 ; Apoptosis/*drug effects ; Bacterial Outer Membrane Proteins/*pharmacology ; Caspase 3/metabolism ; Fluorescein-5-isothiocyanate ; Humans ; In Situ Nick-End Labeling ; Interleukin-8/metabolism ; Nematoda/microbiology ; Neutrophils/*drug effects/physiology ; Wolbachia/metabolism ; }, abstract = {Polymorphonuclear cells (PMNs) are essential for the innate immune response against invading bacteria. At the same time, modulation of PMNs' apoptosis or cell death by bacteria has emerged as a mechanism of pathogenesis. Wolbachia bacteria are Gram-negative endosymbionts of filarial nematodes and arthropods, phylogenetically related to the genera Anaplasma, Ehrlichia and Neorickettsia (family Anaplasmataceae). Although several pathogens are known to interfere with apoptosis, there is only limited information on specific proteins that modulate this phenomenon. This is the first evidence for the anti-apoptotic activity of a surface protein of Wolbachia from filarial nematode parasites (the Wolbachia surface protein, WSP). The inhibition of apoptosis was demonstrated on purified human PMNs in vitro by different methods. TUNEL assay showed that the percentage of dead cells was reduced after stimulation with WSP; Annexin V-FITC binding assay confirmed that cell death was due mainly to apoptosis and not to necrosis. Reduced caspase-3 activity in stimulated cells also confirmed an inhibition of the apoptotic process.}, }
@article {pmid17240180, year = {2007}, author = {Carney, SL and Flores, JF and Orobona, KM and Butterfield, DA and Fisher, CR and Schaeffer, SW}, title = {Environmental differences in hemoglobin gene expression in the hydrothermal vent tubeworm, Ridgeia piscesae.}, journal = {Comparative biochemistry and physiology. Part B, Biochemistry &amp; molecular biology}, volume = {146}, number = {3}, pages = {326-337}, doi = {10.1016/j.cbpb.2006.11.002}, pmid = {17240180}, issn = {1096-4959}, mesh = {Animals ; Body Fluids/chemistry/metabolism ; *Environment ; Gene Expression ; Globins/chemistry/genetics ; Hemoglobins/genetics/*metabolism ; Hypothermia ; Molecular Sequence Data ; Phenotype ; Phylogeny ; Polychaeta/anatomy &amp; histology/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction/methods ; }, abstract = {Ridgeia piscesae, the siboglinid tubeworm inhabiting the hydrothermal vents of the northeast Pacific Juan de Fuca Ridge, displays a wide range of microhabitat-specific, genetically indistinguishable phenotypes. Local microhabitat conditions are hypothesized to play a role in the differentiation of R. piscesae phenotypes. Extracellular hemoglobins serve to connect the tubeworm and the surrounding vent fluid, binding environmental sulfide and oxygen for transport to endosymbionts that use the chemical energy for carbon fixation. Because hemoglobin is essential for this symbiosis, we examined its expression in two of the most extreme R. piscesae phenotypes at two levels: the mRNA encoding the globin subunits and the whole molecules in coelomic and vascular fluids. Levels of gene expression were up to 12 times greater in short-fat R. piscesae from higher temperature, sulfide chimney environments compared to long-skinny animals from a low temperature, diffuse flow basalt habitat. Gene expression levels were consistent with the relative concentrations of hemoglobin molecules in the vascular and coelomic fluids. Up to a 20-fold variation in globin gene expression was detected between the same phenotype from different sites. These data demonstrate that local environmental factors influence not only phenotype but gene expression and its resulting physiological outcome within this unique species.}, }
@article {pmid17238918, year = {2007}, author = {Richmond, GS and Smith, TK}, title = {A novel phospholipase from Trypanosoma brucei.}, journal = {Molecular microbiology}, volume = {63}, number = {4}, pages = {1078-1095}, pmid = {17238918}, issn = {0950-382X}, support = {067441//Wellcome Trust/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Catalytic Domain ; Cloning, Molecular ; Cytosol/enzymology ; Evolution, Molecular ; Hydrolysis ; Lysophosphatidylcholines/metabolism ; Molecular Sequence Data ; Mutation ; Phosphatidylcholines/metabolism ; Phospholipases A/*genetics/*metabolism ; Phylogeny ; Recombinant Proteins/genetics/isolation &amp; purification/metabolism ; Sequence Homology, Amino Acid ; Substrate Specificity ; Trypanosoma brucei brucei/*enzymology/genetics ; }, abstract = {Phospholipase A(1) activities have been detected in most cells where they have been sought and yet their characterization lags far behind that of the phospholipases A(2), C and D. The study presented here details the first cloning and characterization of a cytosolic PLA(1) that exhibits preference for phosphatidylcholine (GPCho) substrates. Trypanosoma brucei phospholipase A(1) (TbPLA(1)) is unique from previously identified eukaryotic PLA(1) because it is evolutionarily related to bacterial secreted PLA(1). A T. brucei ancestor most likely acquired the PLA(1) from a horizontal gene transfer of a PLA(1) from Sodalis glossinidius, a bacterial endosymbiont of tsetse flies. Nano-electrospray ionization tandem mass spectrometry analysis of TbPLA(1) mutants established that the enzyme functions in vivo to synthesize lysoGPCho metabolites containing long-chain mostly polyunsaturated and highly unsaturated fatty acids. Analysis of purified mutated recombinant forms of TbPLA(1) revealed that this enzyme is a serine hydrolase whose catalytic mechanism involves a triad consisting of the amino acid residues Ser-131, His-234 and Asp-183. The TbPLA(1) homozygous null mutants generated here constitute the only PLA(1) double knockouts from any organism.}, }
@article {pmid17237039, year = {2007}, author = {Delcher, AL and Bratke, KA and Powers, EC and Salzberg, SL}, title = {Identifying bacterial genes and endosymbiont DNA with Glimmer.}, journal = {Bioinformatics (Oxford, England)}, volume = {23}, number = {6}, pages = {673-679}, pmid = {17237039}, issn = {1367-4811}, support = {R01 GM083873/GM/NIGMS NIH HHS/United States ; R01-LM006845/LM/NLM NIH HHS/United States ; R01 LM006845-08/LM/NLM NIH HHS/United States ; R01 LM007938/LM/NLM NIH HHS/United States ; R01-LM007938/LM/NLM NIH HHS/United States ; R01 LM006845/LM/NLM NIH HHS/United States ; R01 LM007938-04/LM/NLM NIH HHS/United States ; HHSN266200400038C//PHS HHS/United States ; }, mesh = {Algorithms ; Animals ; Artifacts ; Chromosome Mapping/*methods ; DNA, Bacterial/*genetics ; Decapodiformes/*genetics/microbiology ; Genome, Bacterial/*genetics ; Prochloron/*genetics ; Reproducibility of Results ; Sensitivity and Specificity ; Sequence Analysis, DNA/methods ; *Software ; Symbiosis/*genetics ; }, abstract = {MOTIVATION: The Glimmer gene-finding software has been successfully used for finding genes in bacteria, archaea and viruses representing hundreds of species. We describe several major changes to the Glimmer system, including improved methods for identifying both coding regions and start codons. We also describe a new module of Glimmer that can distinguish host and endosymbiont DNA. This module was developed in response to the discovery that eukaryotic genome sequencing projects sometimes inadvertently capture the DNA of intracellular bacteria living in the host.<br><br>RESULTS: The new methods dramatically reduce the rate of false-positive predictions, while maintaining Glimmer's 99% sensitivity rate at detecting genes in most species, and they find substantially more correct start sites, as measured by comparisons to known and well-curated genes. We show that our interpolated Markov model (IMM) DNA discriminator correctly separated 99% of the sequences in a recent genome project that produced a mixture of sequences from the bacterium Prochloron didemni and its sea squirt host, Lissoclinum patella.<br><br>AVAILABILITY: Glimmer is OSI Certified Open Source and available at http://cbcb.umd.edu/software/glimmer.}, }
@article {pmid17229454, year = {2007}, author = {Kádár, E and Costa, V and Segonzac, M}, title = {Trophic influences of metal accumulation in natural pollution laboratories at deep-sea hydrothermal vents of the Mid-Atlantic Ridge.}, journal = {The Science of the total environment}, volume = {373}, number = {2-3}, pages = {464-472}, doi = {10.1016/j.scitotenv.2006.12.022}, pmid = {17229454}, issn = {0048-9697}, mesh = {Animals ; Atlantic Ocean ; Ecosystem ; Invertebrates/*drug effects/metabolism ; *Mercury/analysis/pharmacokinetics/toxicity ; Species Specificity ; Symbiosis ; Temperature ; Tissue Distribution ; Trace Elements/analysis/*pharmacokinetics ; *Water Pollutants, Chemical/analysis/pharmacokinetics/toxicity ; }, abstract = {This study reports on the concentration of both, toxic (Hg) and essential (Fe, Cu, Zn) metals in representative species, at four hydrothermal vents along the Mid-Atlantic Ridge (MAR) corresponding to the different exposure conditions that are the result of contrasted geological setting and different depths along the ridge axis. Macro fauna collected from these vent sites showed markedly different whole tissue concentration of metals reflecting exposure levels. Bio-transfer of metals within a typical hydrothermal food chain was investigated. There were trophic level-specific variations in essential metal accumulation showing a general trend within which the secondary consumers (predators/scavengers) and primary consumers (filter-feeder/symbiont reliant species like the mixotrophic mollusks and sponges all having metal concentrations above those in passive suspension-feeders such as echinoderms, gorgonians) accumulated highest concentrations of all elements followed by primary producers such as endosymbiont bacteria. Mercury accumulation followed a somewhat different sequence among the same taxonomic groups: top concentrations in the symbiont-bearing filter-feeder bivalves >crustaceans> sponges > bacteria > echinoderms, gorgonians and tunicates. There were no indications of biomagnification of Hg, Cu and Zn unlike Fe that showed positive transference factors (TF) along two trophic levels of a typical chain at Menez Gwen.}, }
@article {pmid17227954, year = {2007}, author = {Perotti, MA and Allen, JM and Reed, DL and Braig, HR}, title = {Host-symbiont interactions of the primary endosymbiont of human head and body lice.}, journal = {FASEB journal : official publication of the Federation of American Societies for Experimental Biology}, volume = {21}, number = {4}, pages = {1058-1066}, doi = {10.1096/fj.06-6808com}, pmid = {17227954}, issn = {1530-6860}, mesh = {Animals ; Biological Evolution ; Female ; *Host-Parasite Interactions ; Humans ; Immune System ; *Lice Infestations ; Male ; Models, Biological ; Pediculus/*microbiology/*pathogenicity ; Phylogeny ; Scalp/*metabolism ; Species Specificity ; Symbiosis ; }, abstract = {The first mycetome was discovered more than 340 yr ago in the human louse. Despite the remarkable biology and medical and social importance of human lice, its primary endosymbiont has eluded identification and characterization. Here, we report the host-symbiont interaction of the mycetomic bacterium of the head louse Pediculus humanus capitis and the body louse P. h. humanus. The endosymbiont represents a new bacterial lineage in the gamma-Proteobacteria. Its closest sequenced relative is Arsenophonus nasoniae, from which it differs by more than 10%. A. nasoniae is a male-killing endosymbiont of jewel wasps. Using microdissection and multiphoton confocal microscopy, we show the remarkable interaction of this bacterium with its host. This endosymbiont is unique because it occupies sequentially four different mycetomes during the development of its host, undergoes three cycles of proliferation, changes in length from 2-4 microm to more than 100 microm, and has two extracellular migrations, during one of which the endosymbionts have to outrun its host's immune cells. The host and its symbiont have evolved one of the most complex interactions: two provisional or transitory mycetomes, a main mycetome and a paired filial mycetome. Despite the close relatedness of body and head lice, differences are present in the mycetomic provisioning and the immunological response.}, }
@article {pmid17226040, year = {2007}, author = {Rymaszewska, A}, title = {Symbiotic bacteria in oocyte and ovarian cell mitochondria of the tick Ixodes ricinus: biology and phylogenetic position.}, journal = {Parasitology research}, volume = {100}, number = {5}, pages = {917-920}, pmid = {17226040}, issn = {0932-0113}, mesh = {Animals ; Bacteria/*classification/genetics/isolation &amp; purification ; Bacterial Physiological Phenomena ; Ixodes/*microbiology/physiology ; Mitochondria/*microbiology ; Oocytes/*microbiology ; Phylogeny ; Symbiosis ; }, abstract = {Under natural conditions, eukaryote cells may contain bacteria. Arthropods such as ticks, insects or mites are a group particularly favoured by the obligate intracellular bacteria. While arthropods are vectors for some of them, other bacteria inhabit invertebrate host cells having entered mutualistic interactions. Such endosymbionts dwell usually in the host cell vacuoles or cytoplasm but have been also reported from tick oocyte mitochondria. The microorganisms contribute to mitochondria degradation, but their colonies are not eliminated from the tick cells affected. So far, such bacteria have been detected in three research centres. The Italian centre has reported on results of microscope and molecular analyses, while the Polish centre published molecular data. The Danish centre registered a 16S rRNA gene fragment in GenBank. Independent comparisons of the 16S rRNA gene sequences, carried out in the Italian and Polish centres, confirmed that the nucleotide sequences of the Ixodes ricinus endosymbionts formed a single clade with certain non-identified tick bacterium species isolated from the tick Haemaphysalis wellingtoni. On the other hand, pathogenic species of the genera Anaplasma, Ehrlichia and Rickettsia detected in I. ricinus as well as symbionts of the genus Wolbachia present in Culex pipiens and Drosophila simulans have been placed at a different site on the phylogenetic tree.}, }
@article {pmid17222133, year = {2007}, author = {Vannini, C and Pöckl, M and Petroni, G and Wu, QL and Lang, E and Stackebrandt, E and Schrallhammer, M and Richardson, PM and Hahn, MW}, title = {Endosymbiosis in statu nascendi: close phylogenetic relationship between obligately endosymbiotic and obligately free-living Polynucleobacter strains (Betaproteobacteria).}, journal = {Environmental microbiology}, volume = {9}, number = {2}, pages = {347-359}, doi = {10.1111/j.1462-2920.2006.01144.x}, pmid = {17222133}, issn = {1462-2912}, mesh = {Animals ; Base Composition ; Burkholderiaceae/*classification/genetics/physiology ; DNA, Ribosomal Spacer/chemistry/classification ; Euplotes/microbiology ; Fresh Water/microbiology ; Genome, Bacterial ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/chemistry/classification ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Bacterial strains affiliated to the phylogenetically shallow subcluster C (PnecC) of the Polynucleobacter cluster, which is characterized by a minimal 16S rRNA gene sequence similarity of approximately 98.5%, have been reported to occur as obligate endosymbionts of ciliates (Euplotes spp.), as well as to occur as free-living cells in the pelagic zone of freshwater habitats. We investigated if these two groups of closely related bacteria represent strains fundamentally differing in lifestyle, or if they simply represent different stages of a facultative endosymbiotic lifestyle. The phylogenetic analysis of 16S rRNA gene and 16S-23S ITS sequences of five endosymbiont strains from two different Euplotes species and 40 pure culture strains demonstrated host-species-specific clustering of the endosymbiont sequences within the PnecC subcluster. The sequences of the endosymbionts showed characteristics indicating an obligate endosymbiotic lifestyle. Cultivation experiments revealed fundamental differences in physiological adaptations, and determination of the genome sizes indicated a slight size reduction in endosymbiotic strains. We conclude that the two groups of PnecC bacteria represent obligately free-living and obligately endosymbiotic strains, respectively, and do not represent different stages of the same complex life cycle. These closely related strains occupy completely separated ecological niches. To our best knowledge, this is the closest phylogenetic relationship between obligate endosymbionts and obligately free-living bacteria ever revealed.}, }
@article {pmid17220259, year = {2007}, author = {Allen, JM and Reed, DL and Perotti, MA and Braig, HR}, title = {Evolutionary relationships of "Candidatus Riesia spp.," endosymbiotic enterobacteriaceae living within hematophagous primate lice.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {5}, pages = {1659-1664}, pmid = {17220259}, issn = {0099-2240}, mesh = {Animals ; Ape Diseases/parasitology ; Bayes Theorem ; DNA, Bacterial/analysis/isolation &amp; purification ; Enterobacteriaceae/*classification/genetics/isolation &amp; purification ; *Evolution, Molecular ; Humans ; Lice Infestations/parasitology/veterinary ; Molecular Sequence Data ; Pan troglodytes/*parasitology ; Pediculus/*microbiology ; Phthirus/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The primary endosymbiotic bacteria from three species of parasitic primate lice were characterized molecularly. We have confirmed the characterization of the primary endosymbiont (P-endosymbiont) of the human head/body louse Pediculus humanus and provide new characterizations of the P-endosymbionts from Pediculus schaeffi from chimpanzees and Pthirus pubis, the pubic louse of humans. The endosymbionts show an average percent sequence divergence of 11 to 15% from the most closely related known bacterium "Candidatus Arsenophonus insecticola." We propose that two additional species be added to the genus "Candidatus Riesia." The new species proposed within "Candidatus Riesia" have sequence divergences of 3.4% and 10 to 12% based on uncorrected pairwise differences. Our Bayesian analysis shows that the branching pattern for the primary endosymbionts was the same as that for their louse hosts, suggesting a long coevolutionary history between primate lice and their primary endosymbionts. We used a calibration of 5.6 million years to date the divergence between endosymbionts from human and chimpanzee lice and estimated an evolutionary rate of nucleotide substitution of 0.67% per million years, which is 15 to 30 times faster than previous estimates calculated for Buchnera, the primary endosymbiont in aphids. Given the evidence for cospeciation with primate lice and the evidence for fast evolutionary rates, this lineage of endosymbiotic bacteria can be evaluated as a fast-evolving marker of both louse and primate evolutionary histories.}, }
@article {pmid17218528, year = {2007}, author = {Markert, S and Arndt, C and Felbeck, H and Becher, D and Sievert, SM and Hügler, M and Albrecht, D and Robidart, J and Bench, S and Feldman, RA and Hecker, M and Schweder, T}, title = {Physiological proteomics of the uncultured endosymbiont of Riftia pachyptila.}, journal = {Science (New York, N.Y.)}, volume = {315}, number = {5809}, pages = {247-250}, doi = {10.1126/science.1132913}, pmid = {17218528}, issn = {1095-9203}, mesh = {Animals ; Bacterial Proteins/analysis/*metabolism ; Carbon/metabolism ; Carbon Dioxide/metabolism ; Chemoautotrophic Growth ; Citric Acid Cycle ; Cytosol/metabolism ; *Ecosystem ; Energy Metabolism ; Gammaproteobacteria/enzymology/genetics/*metabolism ; Genome, Bacterial ; Hydrogen Sulfide/metabolism ; Hydrogen-Ion Concentration ; Metabolic Networks and Pathways ; Molecular Sequence Data ; Oxidation-Reduction ; Pacific Ocean ; Polychaeta/*microbiology ; Proteome ; *Proteomics ; Sulfur/metabolism ; *Symbiosis ; Temperature ; }, abstract = {The bacterial endosymbiont of the deep-sea tube worm Riftia pachyptila has never been successfully cultivated outside its host. In the absence of cultivation data, we have taken a proteomic approach based on the metagenome sequence to study the metabolism of this peculiar microorganism in detail. As one result, we found that three major sulfide oxidation proteins constitute approximately 12% of the total cytosolic proteome, which highlights the essential role of these enzymes for the symbiont's energy metabolism. Unexpectedly, the symbiont uses the reductive tricarboxylic acid cycle in addition to the previously identified Calvin cycle for CO2 fixation.}, }
@article {pmid17216316, year = {2007}, author = {Simón, F and Kramer, LH and Román, A and Blasini, W and Morchón, R and Marcos-Atxutegi, C and Grandi, G and Genchi, C}, title = {Immunopathology of Dirofilaria immitis infection.}, journal = {Veterinary research communications}, volume = {31}, number = {2}, pages = {161-171}, pmid = {17216316}, issn = {0165-7380}, mesh = {Animals ; Cat Diseases/immunology/microbiology/*parasitology/pathology ; Cats ; Dirofilaria immitis/*immunology ; Dirofilariasis/*immunology/pathology ; Dog Diseases/immunology/microbiology/*parasitology/pathology ; Dogs ; Humans ; Immunity, Innate/immunology ; Th1 Cells/immunology/microbiology/parasitology ; Th2 Cells/immunology/microbiology/parasitology ; Wolbachia/immunology ; }, abstract = {Heartworm disease caused by Dirofilaria immitis affects canine and feline hosts, with infections occasionally being reported in humans. Studies have shown that both dirofilarial antigens and those derived from its bacterial endosymbiont Wolbachia, interact with the host organism during canine, feline and human infections and participate in the development of the pathology and in the regulation of the host's immune response. Both innate and acquired immune responses are observed and the development of the acquired response may depend on the host and, or on its parasitological status. This review aims at illustrating current research on the role of both D. immitis and Wolbachia, in the immunology and immunopathology of dirofilariosis.}, }
@article {pmid17211547, year = {2007}, author = {Khan, H and Kozera, C and Curtis, BA and Bussey, JT and Theophilou, S and Bowman, S and Archibald, JM}, title = {Retrotransposons and tandem repeat sequences in the nuclear genomes of cryptomonad algae.}, journal = {Journal of molecular evolution}, volume = {64}, number = {2}, pages = {223-236}, pmid = {17211547}, issn = {0022-2844}, mesh = {Cloning, Molecular ; Cryptophyta/*classification/*genetics ; DNA/genetics/isolation &amp; purification ; Genetic Variation ; Phylogeny ; Polymerase Chain Reaction ; *Repetitive Sequences, Nucleic Acid ; *Retroelements ; Terminal Repeat Sequences/genetics ; }, abstract = {The cryptomonads are an enigmatic group of unicellular eukaryotic algae that possess two nuclear genomes, having acquired photosynthesis by the uptake and retention of a eukaryotic algal endosymbiont. The endosymbiont nuclear genome, or nucleomorph, of the cryptomonad Guillardia theta has been completely sequenced: at only 551 kilobases (kb) and with a gene density of approximately 1 gene/kb, it is a model of compaction. In contrast, very little is known about the structure and composition of the cryptomonad host nuclear genome. Here we present the results of two small-scale sequencing surveys of fosmid clone libraries from two distantly related cryptomonads, Rhodomonas salina CCMP1319 and Cryptomonas paramecium CCAP977/2A, corresponding to approximately 150 and approximately 235 kb of sequence, respectively. Very few of the random end sequences determined in this study show similarity to known genes in other eukaryotes, underscoring the considerable evolutionary distance between the cryptomonads and other eukaryotes whose nuclear genomes have been completely sequenced. Using a combination of fosmid clone end-sequencing, Southern hybridizations, and PCR, we demonstrate that Ty3-gypsy long-terminal repeat (LTR) retrotransposons and tandem repeat sequences are a prominent feature of the nuclear genomes of both organisms. The complete sequence of a 30.9-kb genomic fragment from R. salina was found to contain a full-length Ty3-gypsy element with near-identical LTRs and a chromodomain, a protein module suggested to mediate the site-specific integration of the retrotransposon. The discovery of chromodomain-containing retroelements in cryptomonads further expands the known distribution of the so-called chromoviruses across the tree of eukaryotes.}, }
@article {pmid17209029, year = {2007}, author = {Clark, AJ and Pontes, M and Jones, T and Dale, C}, title = {A possible heterodimeric prophage-like element in the genome of the insect endosymbiont Sodalis glossinidius.}, journal = {Journal of bacteriology}, volume = {189}, number = {7}, pages = {2949-2951}, pmid = {17209029}, issn = {0021-9193}, mesh = {Animals ; Base Sequence ; Capsid ; Enterobacteriaceae/*genetics/*physiology/virology ; Extrachromosomal Inheritance/*genetics ; Genome, Bacterial ; Insecta/microbiology ; Molecular Sequence Data ; Repetitive Sequences, Nucleic Acid ; Symbiosis ; }, abstract = {Extrachromosomal element pSOG3 (52,162 nucleotides) in the genome of Sodalis glossinidius contains redundant phage-related gene pairs, indicating that it may have been formed by the fusion of two ancestral phage genomes followed by gene degradation. We suggest that pSOG3 is a prophage that has undergone genome degeneration accompanying host adaptation to symbiosis.}, }
@article {pmid17209018, year = {2007}, author = {Keating, DH}, title = {Sinorhizobium meliloti SyrA mediates the transcriptional regulation of genes involved in lipopolysaccharide sulfation and exopolysaccharide biosynthesis.}, journal = {Journal of bacteriology}, volume = {189}, number = {6}, pages = {2510-2520}, pmid = {17209018}, issn = {0021-9193}, mesh = {Bacterial Proteins/genetics/*metabolism ; Culture Media ; *Gene Expression Regulation, Bacterial ; Lipopolysaccharides/*metabolism ; Polysaccharides, Bacterial/*biosynthesis ; Sinorhizobium meliloti/genetics/growth &amp; development/*metabolism ; Sulfates/metabolism ; Sulfotransferases/genetics/*metabolism ; Symbiosis ; *Transcription, Genetic ; }, abstract = {Sinorhizobium meliloti is a gram-negative soil bacterium found either in free-living form or as a nitrogen-fixing endosymbiont of leguminous plants such as Medicago sativa (alfalfa). S. meliloti synthesizes an unusual sulfate-modified form of lipopolysaccharide (LPS). A recent study reported the identification of a gene, lpsS, which encodes an LPS sulfotransferase activity in S. meliloti. Mutants bearing a disrupted version of lpsS exhibit an altered symbiosis, in that they elicit more nodules than wild type. However, under free-living conditions, the lpsS mutant displayed no change in LPS sulfation. These data suggest that the expression of lpsS is differentially regulated, such that it is transcriptionally repressed during free-living conditions but upregulated during symbiosis. Here, I show that the expression of lpsS is upregulated in strains that constitutively express the symbiotic regulator SyrA. SyrA is a small protein that lacks an apparent DNA binding domain and is predicted to be located in the cytoplasmic membrane yet is sufficient to upregulate lpsS transcription. Furthermore, SyrA can mediate the transcriptional upregulation of exo genes involved in the biosynthesis of the symbiotic exopolysaccharide succinoglycan. The SyrA-mediated transcriptional upregulation of lpsS and exo transcription is blocked in mutants harboring a mutation in chvI, which encodes the response regulator of a conserved two-component system. Thus, SyrA likely acts indirectly to promote transcriptional upregulation of lpsS and exo genes through a mechanism that requires the ExoS/ChvI two-component system.}, }
@article {pmid17205805, year = {2006}, author = {Spiridonova, EM and Kuznetsov, BB and Pimenov, NV and Turova, TP}, title = {[Phylogenetic characterization of endosymbionts of the hydrothermal vent mussel Bathymodiolus azoricus by analysis of the 16S rRNA, pmoL, and cbbA genes].}, journal = {Mikrobiologiia}, volume = {75}, number = {6}, pages = {798-806}, pmid = {17205805}, issn = {0026-3656}, mesh = {Animals ; Bacterial Proteins/genetics ; Bivalvia/*microbiology ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification ; Gills/microbiology ; Marine Biology ; Methylobacteriaceae/classification/genetics/*isolation &amp; purification ; Oxygenases/genetics ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; Species Specificity ; *Symbiosis ; }, abstract = {In order to assess the phylogenetic diversity of the endosymbiotic microbial community of the gills of marine shellfish Bathymodiolus azoricus, total DNA was extracted from the gills. The PCR fragments corresponding to the genes encoding 16S rRNA, ribulose-bisphosphate carboxylase (cbbL), and particulate methane monooxygenase (pmoA) were amplified, cloned, and sequenced. For the 16S rDNA genes, only one phylotype was revealed; it belonged to the cluster of Mytilidae thiotrophic symbionts within the Gammaproteobacteria. For the RuBisCO genes, two phylotypes were found, both belonging to Gammaproteobacteria. One of them was closely related to the previously known mytilid symbiont, the other, to a pogonophore symbiont, presumably a methanotrophic bacterium. One phylotype of particulate methane oxygenase genes was also revealed; this finding indicated the presence of a methanotrophic symbiont. Phylogenetic analysis of the pmoA placed this endosymbiont within the Gammaproteobacteria, in a cluster including the methanotrophic bacterial genus Methylobacter and other methanotrophic Bathymodiolus gill symbionts. These results provide evidence for the existence of two types of endosymbionts (thioautotrophic and methanotrophic) in the gills of B. azoricus and demonstrate that, apart from the phylogenetic analysis of 16S rRNA genes, parallel analysis of functional genes is essential.}, }
@article {pmid17190825, year = {2007}, author = {Pannebakker, BA and Loppin, B and Elemans, CP and Humblot, L and Vavre, F}, title = {Parasitic inhibition of cell death facilitates symbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {104}, number = {1}, pages = {213-215}, pmid = {17190825}, issn = {0027-8424}, mesh = {Animals ; *Apoptosis ; Female ; *Oogenesis ; *Symbiosis ; Wasps/*parasitology ; Wolbachia/*physiology ; }, abstract = {Symbiotic microorganisms have had a large impact on eukaryotic evolution, with effects ranging from parasitic to mutualistic. Mitochondria and chloroplasts are prime examples of symbiotic microorganisms that have become obligate for their hosts, allowing for a dramatic extension of suitable habitats for life. Out of the extraordinary diversity of bacterial endosymbionts in insects, most are facultative for their hosts, such as the ubiquitous Wolbachia, which manipulates host reproduction. Some endosymbionts, however, have become obligatory for host reproduction and/or survival. In the parasitoid wasp Asobara tabida the presence of Wolbachia is necessary for host oogenesis, but the mechanism involved is yet unknown. We show that Wolbachia influences programmed cell death processes (a host regulatory feature typically targeted by pathogens) in A. tabida, making its presence essential for the wasps' oocytes to mature. This suggests that parasite strategies, such as bacterial regulation of host apoptosis, can drive the evolution of host dependence, allowing for a swift transition from parasitism to mutualism.}, }
@article {pmid17187354, year = {2007}, author = {Poole, AM and Penny, D}, title = {Evaluating hypotheses for the origin of eukaryotes.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {29}, number = {1}, pages = {74-84}, doi = {10.1002/bies.20516}, pmid = {17187354}, issn = {0265-9247}, mesh = {Archaea ; Bacteria ; *Biological Evolution ; *Eukaryotic Cells ; Mitochondria ; *Models, Biological ; Phylogeny ; Symbiosis ; }, abstract = {Numerous scenarios explain the origin of the eukaryote cell by fusion or endosymbiosis between an archaeon and a bacterium (and sometimes a third partner). We evaluate these hypotheses using the following three criteria. Can the data be explained by the null hypothesis that new features arise sequentially along a stem lineage? Second, hypotheses involving an archaeon and a bacterium should undergo standard phylogenetic tests of gene distribution. Third, accounting for past events by processes observed in modern cells is preferable to postulating unknown processes that have never been observed. For example, there are many eukaryote examples of bacteria as endosymbionts or endoparasites, but none known in archaea. Strictly post-hoc hypotheses that ignore this third criterion should be avoided. Applying these three criteria significantly narrows the number of plausible hypotheses. Given current knowledge, our conclusion is that the eukaryote lineage must have diverged from an ancestor of archaea well prior to the origin of the mitochondrion. Significantly, the absence of ancestrally amitochondriate eukaryotes (archezoa) among extant eukaryotes is neither evidence for an archaeal host for the ancestor of mitochondria, nor evidence against a eukaryotic host.}, }
@article {pmid17174902, year = {2006}, author = {Theissen, U and Martin, W}, title = {The difference between organelles and endosymbionts.}, journal = {Current biology : CB}, volume = {16}, number = {24}, pages = {R1016-7; author reply R1017-8}, doi = {10.1016/j.cub.2006.11.020}, pmid = {17174902}, issn = {0960-9822}, mesh = {Animals ; Cyanobacteria/*physiology ; Eukaryota/*microbiology/physiology/*ultrastructure ; Plastids/genetics/*physiology ; Protein Transport ; RNA, Ribosomal, 16S ; *Symbiosis ; }, }
@article {pmid17158613, year = {2007}, author = {Scott, KM and Cavanaugh, CM}, title = {CO2 uptake and fixation by endosymbiotic chemoautotrophs from the bivalve Solemya velum.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {4}, pages = {1174-1179}, pmid = {17158613}, issn = {0099-2240}, mesh = {Animals ; Autotrophic Processes/physiology ; Bivalvia/*metabolism/physiology ; Carbon Dioxide/*metabolism ; Symbiosis/*physiology ; }, abstract = {Chemoautotrophic symbioses, in which endosymbiotic bacteria are the major source of organic carbon for the host, are found in marine habitats where sulfide and oxygen coexist. The purpose of this study was to determine the influence of pH, alternate sulfur sources, and electron acceptors on carbon fixation and to investigate which form(s) of inorganic carbon is taken up and fixed by the gamma-proteobacterial endosymbionts of the protobranch bivalve Solemya velum. Symbiont-enriched suspensions were generated by homogenization of S. velum gills, followed by velocity centrifugation to pellet the symbiont cells. Carbon fixation was measured by incubating the cells with (14)C-labeled dissolved inorganic carbon. When oxygen was present, both sulfide and thiosulfate stimulated carbon fixation; however, elevated levels of either sulfide (>0.5 mM) or oxygen (1 mM) were inhibitory. In the absence of oxygen, nitrate did not enhance carbon fixation rates when sulfide was present. Symbionts fixed carbon most rapidly between pH 7.5 and 8.5. Under optimal pH, sulfide, and oxygen conditions, symbiont carbon fixation rates correlated with the concentrations of extracellular CO(2) and not with HCO(3)(-) concentrations. The half-saturation constant for carbon fixation with respect to extracellular dissolved CO(2) was 28 +/- 3 microM, and the average maximal velocity was 50.8 +/- 7.1 micromol min(-1) g of protein(-1). The reliance of S. velum symbionts on extracellular CO(2) is consistent with their intracellular lifestyle, since HCO(3)(-) utilization would require protein-mediated transport across the bacteriocyte membrane, perisymbiont vacuole membrane, and symbiont outer and inner membranes. The use of CO(2) may be a general trait shared with many symbioses with an intracellular chemoautotrophic partner.}, }
@article {pmid17158610, year = {2007}, author = {Wilkinson, TL and Koga, R and Fukatsu, T}, title = {Role of host nutrition in symbiont regulation: impact of dietary nitrogen on proliferation of obligate and facultative bacterial endosymbionts of the pea aphid Acyrthosiphon pisum.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {4}, pages = {1362-1366}, pmid = {17158610}, issn = {0099-2240}, mesh = {Animals ; Aphids/*microbiology/physiology ; *Bacterial Physiological Phenomena ; Nitrogen/*pharmacology ; Peas/parasitology ; Serratia/*physiology ; Symbiosis/*physiology ; }, abstract = {The impact of host nutrition on symbiont regulation in the pea aphid Acyrthosiphon pisum was investigated. The population density of the obligate symbiont Buchnera aphidicola positively correlated with dietary nitrogen levels. In contrast, the population density of the facultative symbiont Serratia symbiotica increased in aphids reared on low-nitrogen diets, indicating distinct regulatory mechanisms in the same insect host.}, }
@article {pmid17156426, year = {2006}, author = {Poole, AM}, title = {Did group II intron proliferation in an endosymbiont-bearing archaeon create eukaryotes?.}, journal = {Biology direct}, volume = {1}, number = {}, pages = {36}, pmid = {17156426}, issn = {1745-6150}, abstract = {Martin &amp; Koonin recently proposed that the eukaryote nucleus evolved as a quality control mechanism to prevent ribosome readthrough into introns. In their scenario, the bacterial ancestor of mitochondria was resident in an archaeal cell, and group II introns (carried by the fledgling mitochondrion) inserted into coding regions in the archaeal host genome. They suggest that if transcription and translation were coupled, and because splicing is expected to have been slower than translation, the effect of insertion would have been ribosome readthrough into introns, resulting in production of aberrant proteins. The emergence of the nuclear compartment would thus have served to separate transcription and splicing from translation, thereby alleviating this problem. In this article, I argue that Martin &amp; Koonin's model is not compatible with current knowledge. The model requires that group II introns would spread aggressively through an archaeal genome. It is well known that selfish elements can spread through an outbreeding sexual population despite a substantial fitness cost to the host. The same is not true for asexual lineages however, where both theory and observation argue that such elements will be under pressure to reduce proliferation, and may be lost completely. The recent introduction of group II introns into archaea by horizontal transfer provides a natural test case with which to evaluate Martin &amp; Koonin's model. The distribution and behaviour of these introns fits prior theoretical expectations, not the scenario of aggressive proliferation advocated by Martin &amp; Koonin. I therefore conclude that the mitochondrial seed hypothesis for the origin of eukaryote introns, on which their model is based, better explains the early expansion of introns in eukaryotes. The mitochondrial seed hypothesis has the capacity to separate the origin of eukaryotes from the origin of introns, leaving open the possibility that the cell that engulfed the ancestor of mitochondria was a sexually outcrossing eukaryote cell.}, }
@article {pmid17154220, year = {2007}, author = {Partida-Martinez, LP and Hertweck, C}, title = {A gene cluster encoding rhizoxin biosynthesis in "Burkholderia rhizoxina", the bacterial endosymbiont of the fungus Rhizopus microsporus.}, journal = {Chembiochem : a European journal of chemical biology}, volume = {8}, number = {1}, pages = {41-45}, doi = {10.1002/cbic.200600393}, pmid = {17154220}, issn = {1439-4227}, mesh = {Antimitotic Agents/pharmacology ; Burkholderia ; Chromatography, High Pressure Liquid ; Cosmids/metabolism ; Fungi/*metabolism ; Gene Library ; Macrolides/*chemistry ; Models, Chemical ; Multigene Family ; Mutation ; Rhizopus/*metabolism ; Sequence Analysis, DNA ; Symbiosis ; Time Factors ; }, }
@article {pmid17151259, year = {2007}, author = {Engelstädter, J and Hurst, GD}, title = {The impact of male-killing bacteria on host evolutionary processes.}, journal = {Genetics}, volume = {175}, number = {1}, pages = {245-254}, pmid = {17151259}, issn = {0016-6731}, mesh = {Animals ; *Biological Evolution ; Computer Simulation ; Female ; Gene Flow ; Insecta/growth &amp; development/*microbiology ; Male ; Models, Biological ; Polymorphism, Genetic ; *Selection, Genetic ; Sex Ratio ; *Symbiosis ; Wolbachia/genetics/growth &amp; development/*pathogenicity ; }, abstract = {Male-killing bacteria are maternally inherited endosymbionts that selectively kill male offspring of their arthropod hosts. Using both analytical techniques and computer simulations, we studied the impact of these bacteria on the population genetics of their hosts. In particular, we derived and corroborated formulas for the fixation probability of mutant alleles, mean times to fixation and fixation or extinction, and heterozygosity for varying male-killer prevalence. Our results demonstrate that infections with male-killing bacteria impede the spread of beneficial alleles, facilitate the spread of deleterious alleles, and reduce genetic variation. The reason for this lies in the strongly reduced fitness of infected females combined with no or very limited gene flow from infected females to uninfected individuals. These two properties of male-killer-infected populations reduce the population size relevant for the initial emergence and spread of mutations. In contrast, use of Wright's equation relating sex ratio to effective population size produces misleading predictions. We discuss the relationship to the similar effect of background selection, the impact of other sex-ratio-distorting endosymbionts, and how our results affect the interpretation of empirical data on genetic variation in male-killer-infected populations.}, }
@article {pmid17150410, year = {2007}, author = {Sanchez-Puerta, MV and Lippmeier, JC and Apt, KE and Delwiche, CF}, title = {Plastid genes in a non-photosynthetic dinoflagellate.}, journal = {Protist}, volume = {158}, number = {1}, pages = {105-117}, doi = {10.1016/j.protis.2006.09.004}, pmid = {17150410}, issn = {1434-4610}, mesh = {Animals ; DNA, Protozoan/analysis ; Dinoflagellida/*genetics/growth &amp; development ; *Evolution, Molecular ; Expressed Sequence Tags ; *Genes, Protozoan ; Molecular Sequence Data ; Photosynthesis/genetics ; Phylogeny ; Plastids/*genetics ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {Dinoflagellates are a diverse group of protists, comprising photosynthetic and heterotrophic free-living species, as well as parasitic ones. About half of them are photosynthetic with peridinin-containing plastids being the most common. It is uncertain whether non-photosynthetic dinoflagellates are primitively so, or have lost photosynthesis. Studies of heterotrophic species from this lineage may increase our understanding of plastid evolution. We analyzed an EST project of the early-diverging heterotrophic dinoflagellate Crypthecodinium cohnii looking for evidence of past endosymbiosis. A large number of putative genes of cyanobacterial or algal origin were identified using BLAST, and later screened by metabolic function. Phylogenetic analyses suggest that several proteins could have been acquired from a photosynthetic endosymbiont, arguing for an earlier plastid acquisition in dinoflagellates. In addition, intact N-terminal plastid-targeting peptides were detected, indicating that C. cohnii may contain a reduced plastid and that some of these proteins are imported into this organelle. A number of metabolic pathways, such as heme and isoprenoid biosynthesis, seem to take place in the plastid. Overall, these data indicate that C. cohnii is derived from a photosynthetic ancestor and provide a model for loss of photosynthesis in dinoflagellates and their relatives. This represents the first extensive genomic analysis of a heterotrophic dinoflagellate.}, }
@article {pmid17148240, year = {2005}, author = {Kondo, N and Shimada, M and Fukatsu, T}, title = {Infection density of Wolbachia endosymbiont affected by co-infection and host genotype.}, journal = {Biology letters}, volume = {1}, number = {4}, pages = {488-491}, pmid = {17148240}, issn = {1744-9561}, mesh = {Animals ; Coleoptera/genetics/*microbiology ; Genotype ; Polymerase Chain Reaction ; Symbiosis/*physiology ; Wolbachia/growth &amp; development/*physiology ; }, abstract = {Infection density is among the most important factors for understanding the biological effects of Wolbachia and other endosymbionts on their hosts. To gain insight into the mechanisms of infection density regulation, we investigated the adzuki bean beetles Callosobruchus chinensis and their Wolbachia endosymbionts. Double-infected, single-infected and uninfected host strains with controlled nuclear genetic backgrounds were generated by introgression, and infection densities in these strains were evaluated by a quantitative polymerase chain reaction technique. Our study revealed previously unknown aspects of Wolbachia density regulation: (i) the identification of intra-specific host genotypes that affect Wolbachia density differently and (ii) the suppression of Wolbachia density by co-infecting Wolbachia strains. These findings shed new light on symbiont-symbiont and host-symbiont interactions in the Wolbachia-insect endosymbiosis and strongly suggest that Wolbachia density is determined through a complex interaction between host genotype, symbiont genotype and other factors.}, }
@article {pmid17141613, year = {2006}, author = {Reyes-Prieto, A and Hackett, JD and Soares, MB and Bonaldo, MF and Bhattacharya, D}, title = {Cyanobacterial contribution to algal nuclear genomes is primarily limited to plastid functions.}, journal = {Current biology : CB}, volume = {16}, number = {23}, pages = {2320-2325}, doi = {10.1016/j.cub.2006.09.063}, pmid = {17141613}, issn = {0960-9822}, mesh = {Cell Nucleus/*metabolism ; Cyanobacteria/*genetics ; Cyanophora/classification/*genetics/physiology ; Gene Transfer, Horizontal ; *Genome ; Phylogeny ; Plastids/*physiology ; Symbiosis ; }, abstract = {A single cyanobacterial primary endosymbiosis that occurred approximately 1.5 billion years ago is believed to have given rise to the plastid in the common ancestor of the Plantae or Archaeplastida--the eukaryotic supergroup comprising red, green (including land plants), and glaucophyte algae. Critical to plastid establishment was the transfer of endosymbiont genes to the host nucleus (i.e., endosymbiotic gene transfer [EGT]). It has been postulated that plastid-derived EGT played a significant role in plant nuclear-genome evolution, with 18% (or 4,500) of all nuclear genes in Arabidopsis thaliana having a cyanobacterial origin with about one-half of these recruited for nonplastid functions. Here, we determine whether the level of cyanobacterial gene recruitment proposed for Arabidopsis is of the same magnitude in the algal sisters of plants by analyzing expressed-sequence tag (EST) data from the glaucophyte alga Cyanophora paradoxa. Bioinformatic analysis of 3,576 Cyanophora nuclear genes shows that 10.8% of these with significant database hits are of cyanobacterial origin and one-ninth of these have nonplastid functions. Our data indicate that unlike plants, early-diverging algal groups appear to retain a smaller number of endosymbiont genes in their nucleus, with only a minor proportion of these recruited for nonplastid functions.}, }
@article {pmid17139418, year = {2007}, author = {Pienaar, RN and Sakai, H and Horiguchi, T}, title = {Description of a new dinoflagellate with a diatom endosymbiont, Durinskia capensis sp. nov. (Peridiniales, Dinophyceae) from South Africa.}, journal = {Journal of plant research}, volume = {120}, number = {2}, pages = {247-258}, pmid = {17139418}, issn = {0918-9440}, mesh = {Animals ; Diatoms/*cytology/ultrastructure ; Dinoflagellida/*cytology/ultrastructure ; Likelihood Functions ; Microscopy, Electron, Scanning ; Phylogeny ; South Africa ; *Symbiosis ; }, abstract = {A new dinoflagellate Durinskia capensis Pienaar, Sakai et Horiguchi sp. nov. (Peridiniales, Dinophyceae), from tidal pools along the west coast of the Cape Peninsula, Republic of South Africa, is described. The dinoflagellate produces characteristic dense orange-red colored blooms in tidal pools. The organism is characterized by having a eukaryotic endosymbiotic alga. Ultrastructure study revealed the organism has a cellular construction similar to that of other diatom-harboring dinoflagellates. The cell is thecate and the plate formula is: Po, x, 4', 2a, 6'', 5c, 4s, 5''', 2'''', which is the same as that of Durinskia baltica, the type species of the genus Durinskia. D. capensis can, however, be distinguished from D. baltica by overall cell shape, the relative size of the 1a and 2a plates, the degree of cingular displacement, and the shape of the eyespot. Our molecular analysis based on SSU rDNA revealed that D. capensis is closely allied to D. baltica, thus supporting the assignment of this new species to this genus. This Durinskia clade takes a sister position to another diatom-harboring dinoflagellate clade, which includes Kryptoperidinium foliaceum and Galeidinium rugatum. Molecular analysis based on the rbcL gene sequence and ultrastructure study revealed that the endosymbiont of D. capensis is a diatom. The SSU rDNA gene trees indicated that four species with a diatom endosymbiont formed a clade, suggesting a single endosymbiotic origin.}, }
@article {pmid17138581, year = {2007}, author = {Maple, J and Møller, SG}, title = {Plastid division: evolution, mechanism and complexity.}, journal = {Annals of botany}, volume = {99}, number = {4}, pages = {565-579}, pmid = {17138581}, issn = {0305-7364}, mesh = {Arabidopsis Proteins ; *Biological Evolution ; Cell Division/physiology ; Chloroplasts/*physiology ; Escherichia coli/cytology ; *Models, Biological ; Plant Proteins/physiology ; Plastids/physiology ; }, abstract = {BACKGROUND: The continuity of chloroplasts is maintained by division of pre-existing chloroplasts. Chloroplasts originated as bacterial endosymbionts; however, the majority of bacterial division factors are absent from chloroplasts and the eukaryotic host has added several new components. For example, the ftsZ gene has been duplicated and modified, and the Min system has retained MinE and MinD but lost MinC, acquiring at least one new component ARC3. Further, the mechanism has evolved to include two members of the dynamin protein family, ARC5 and FZL, and plastid-dividing (PD) rings were most probably added by the eukaryotic host.<br><br>SCOPE: Deciphering how the division of plastids is coordinated and controlled by nuclear-encoded factors is key to our understanding of this important biological process. Through a number of molecular-genetic and biochemical approaches, it is evident that FtsZ initiates plastid division where the coordinated action of MinD and MinE ensures correct FtsZ (Z)-ring placement. Although the classical FtsZ antagonist MinC does not exist in plants, ARC3 may fulfil this role. Together with other prokaryotic-derived proteins such as ARC6 and GC1 and key eukaryotic-derived proteins such as ARC5 and FZL, these proteins make up a sophisticated division machinery. The regulation of plastid division in a cellular context is largely unknown; however, recent microarray data shed light on this. Here the current understanding of the mechanism of chloroplast division in higher plants is reviewed with an emphasis on how recent findings are beginning to shape our understanding of the function and evolution of the components.<br><br>CONCLUSIONS: Extrapolation from the mechanism of bacterial cell division provides valuable clues as to how the chloroplast division process is achieved in plant cells. However, it is becoming increasingly clear that the highly regulated mechanism of plastid division within the host cell has led to the evolution of features unique to the plastid division process.}, }
@article {pmid17126589, year = {2007}, author = {Morchón, R and Bazzocchi, C and López-Belmonte, J and Martín-Pacho, JR and Kramer, LH and Grandi, G and Simón, F}, title = {iNOs expression is stimulated by the major surface protein (rWSP) from Wolbachia bacterial endosymbiont of Dirofilaria immitis following subcutaneous injection in mice.}, journal = {Parasitology international}, volume = {56}, number = {1}, pages = {71-75}, doi = {10.1016/j.parint.2006.10.003}, pmid = {17126589}, issn = {1383-5769}, mesh = {Animals ; Antibodies, Bacterial/biosynthesis ; Bacterial Outer Membrane Proteins/*immunology ; Chaperonin 60/immunology ; Dirofilaria immitis/*microbiology/physiology ; Dirofilariasis/immunology/parasitology ; Inflammation/immunology ; Interferon-gamma/genetics/immunology ; Interleukin-10/genetics ; Interleukin-4/genetics ; Mice ; Mice, Inbred BALB C ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type II/genetics/*metabolism ; RNA, Messenger ; Recombinant Proteins/immunology ; Symbiosis ; Th1 Cells/immunology ; Wolbachia/*immunology/physiology ; }, abstract = {The bacterial endosymbiont Wolbachia of several species of filarial nematodes plays an important role in the inflammatory pathology of filariasis. Nitric oxide (NO) production has also been implicated in the immune response during filarial infections. Here we present data indicating that a recombinant Wolbachia surface protein (rWSP) induces iNOs mRNA expression and NO production, as well as IFN-gamma and a Th1-type antibody response, in inoculated BALB/c mice. This effect is not observed when mice are inoculated with a recombinant heat shock protein from Wolbachia (GroEL).}, }
@article {pmid17125789, year = {2007}, author = {Baldridge, GD and Kurtti, TJ and Burkhardt, N and Baldridge, AS and Nelson, CM and Oliva, AS and Munderloh, UG}, title = {Infection of Ixodes scapularis ticks with Rickettsia monacensis expressing green fluorescent protein: a model system.}, journal = {Journal of invertebrate pathology}, volume = {94}, number = {3}, pages = {163-174}, pmid = {17125789}, issn = {0022-2011}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Cricetinae ; Disease Transmission, Infectious ; Female ; Fluorescent Dyes/*analysis ; Green Fluorescent Proteins/*analysis/genetics ; Insect Vectors/virology ; Ixodes/*microbiology ; Ixodidae/microbiology ; Larva/microbiology ; Male ; Microscopy, Fluorescence ; Models, Animal ; Nymph/microbiology ; Rabbits ; Rickettsia/genetics/*physiology ; Salivary Glands/microbiology ; }, abstract = {Ticks (Acari: Ixodidae) are ubiquitous hosts of rickettsiae (Rickettsiaceae: Rickettsia), obligate intracellular bacteria that occur as a continuum from nonpathogenic arthropod endosymbionts to virulent pathogens of both arthropod vectors and vertebrates. Visualization of rickettsiae in hosts has traditionally been limited to techniques utilizing fixed tissues. We report epifluorescence microscopy observations of unfixed tick tissues infected with a spotted fever group endosymbiont, Rickettsia monacensis, transformed to express green fluorescent protein (GFP). Fluorescent rickettsiae were readily visualized in tick tissues. In adult female, but not male, Ixodes scapularis infected by capillary feeding, R. monacensis disseminated from the gut and infected the salivary glands that are crucial to the role of ticks as vectors. The rickettsiae infected the respiratory tracheal system, a potential dissemination pathway and possible infection reservoir during tick molting. R. monacensis disseminated from the gut of capillary fed I. scapularis nymphs and was transstadially transmitted to adults. Larvae, infected by immersion, transstadially transmitted the rickettsiae to nymphs. Infected female I. scapularis did not transovarially transmit R. monacensis to progeny and the rickettsiae were not horizontally transmitted to a rabbit or hamsters. Survival of infected nymphal and adult I. scapularis did not differ from that of uninfected control ticks. R. monacensis did not disseminate from the gut of capillary fed adult female Amblyomma americanum (L.), or adult Dermacentor variabilis (Say) ticks of either sex. Infection of I. scapularis with R. monacensis expressing GFP provides a model system allowing visualization and study of live rickettsiae in unfixed tissues of an arthropod host.}, }
@article {pmid17125547, year = {2006}, author = {Bakke, TA and Cable, J and Ostbø, M}, title = {The ultrastructure of hypersymbionts on the monogenean Gyrodactylus salaris infecting Atlantic salmon Salmo salar.}, journal = {Journal of helminthology}, volume = {80}, number = {4}, pages = {377-386}, doi = {10.1017/joh2006368}, pmid = {17125547}, issn = {0022-149X}, mesh = {Animals ; Bacteria/*ultrastructure ; Eukaryota/*ultrastructure ; Fish Diseases/microbiology/*parasitology ; Host-Parasite Interactions ; Life Cycle Stages ; Microscopy, Electron, Scanning ; Norway ; Salmo salar/microbiology/*parasitology ; Seasons ; Symbiosis ; Trematoda/*microbiology/parasitology ; }, abstract = {There is increasing pressure to develop alternative control strategies against the pathogen Gyrodactylus salaris, which has devastated wild Atlantic salmon Salmo salar in Norway. Hyperparasitism is one option for biological control and electron microscopy has revealed two ectosymbionts associated with G. salaris: unidentified rod-shaped bacteria, and the protist, Ichthyobodo necator. No endosymbionts were detected. The flagellate I. necator occurred only occasionally on fish suffering costiosis, whereas bacterial infections on the tegument of G. salaris were observed throughout the year, but at variable densities. Bacteria were seldom observed attached to fish epidermis, even when individuals of G. salaris on the same host were heavily infected. Wounds on salmon epidermis caused by the feeding activity of bacteria-infected G. salaris did not appear to be infected with bacteria. On heavily infected gyrodactylids, bacteria were most abundant anteriorly on the cephalic lobes, including the sensory structures, but no damaged tissue was detected by transmission electron microscopy in the region of bacterial adherence. Furthermore, transmission and survival of infected G. salaris on wild salmon did not appear to be influenced by the bacterial infection. The lack of structural damage and impact on G. salaris biology indicates that these bacteria are not a potential agent for control of gyrodactylosis. However, this may not be the case for all gyrodactylid-bacterial interactions and a review of bacterial infections of platyhelminths is presented.}, }
@article {pmid17123904, year = {2006}, author = {Corsaro, D and Venditti, D}, title = {Diversity of the parachlamydiae in the environment.}, journal = {Critical reviews in microbiology}, volume = {32}, number = {4}, pages = {185-199}, doi = {10.1080/10408410601023102}, pmid = {17123904}, issn = {1040-841X}, mesh = {Acanthamoeba/microbiology ; Animals ; *Biodiversity ; Chlamydiales/classification/*genetics/*physiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; *Ecosystem ; *Environmental Microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Chlamydiae are obligate intracellular bacteria, parasites of a variety of eukaryotes ranging from amoebae to humans. Among them, the family Parachlamydiaceae comprises endosymbionts of amoebae, mainly Acanthamoeba, currently investigated as emerging pathogens of humans and other vertebrates. 16S rDNA-based PCR culture-independent studies in environmental samples have demonstrated the presence of Chlamydiales in various types of nonmedical habitats. Here we reviewed the biology of the Parachlamydiaceae, and more particularly those studies reporting molecular evidences for their presence in the environment, with a re-analysis of the 16S rDNA phylotypes.}, }
@article {pmid17123416, year = {2006}, author = {Lane, CE and Archibald, JM}, title = {Novel nucleomorph genome architecture in the cryptomonad genus hemiselmis.}, journal = {The Journal of eukaryotic microbiology}, volume = {53}, number = {6}, pages = {515-521}, doi = {10.1111/j.1550-7408.2006.00135.x}, pmid = {17123416}, issn = {1066-5234}, mesh = {Blotting, Southern ; Cell Nucleus ; Cryptophyta/classification/*genetics ; DNA, Ribosomal/*genetics/isolation &amp; purification ; Electrophoresis, Gel, Pulsed-Field ; Eukaryota ; *Genome ; *Repetitive Sequences, Nucleic Acid ; Telomere ; }, abstract = {Cryptomonads are ubiquitous aquatic unicellular eukaryotes that acquired photosynthesis through the uptake and retention of a red algal endosymbiont. The nuclear genome of the red alga persists in a highly reduced form termed a nucleomorph. The nucleomorph genome of the model cryptomonad Guillardia theta has been completely sequenced and is a mere 551 kilobases (kb) in size, spread over three chromosomes. The presence of three chromosomes appears to be a universal characteristic of nucleomorph genomes in cryptomonad algae as well as in the chlorarachniophytes, an unrelated algal lineage with a nucleomorph and plastid genome derived from a green algal endosymbiont. Another feature of nucleomorph genomes in all cryptomonads and chlorarachniophytes examined thus far is the presence of subtelomeric ribosomal DNA (rDNA) repeats at the ends of each chromosome. Here we describe the first exception to this canonical nucleomorph genome architecture in the cryptomonad Hemiselmis rufescens CCMP644. Using pulsed-field gel electrophoresis (PFGE), we estimate the size of the H. rufescens nucleomorph genome to be approximately 580 kb, slightly larger than the G. theta genome. Unlike the situation in G. theta and all other known cryptomonads, sub-telomeric repeats of the rDNA cistron appear to be absent on both ends of the second largest chromosome in H. rufescens and two other members of this genus. Southern hybridizations using a variety of nucleomorph protein gene probes against PFGE-separated H. rufescens chromosomes indicate that recombination has been a major factor in shaping the karyotype and genomic structure of cryptomonad nucleomorphs.}, }
@article {pmid17123414, year = {2006}, author = {Schrallhammer, M and Fokin, SI and Schleifer, KH and Petroni, G}, title = {Molecular characterization of the obligate endosymbiont "Caedibacter macronucleorum"Fokin and Görtz, 1993 and of its host Paramecium duboscqui strain Ku4-8.}, journal = {The Journal of eukaryotic microbiology}, volume = {53}, number = {6}, pages = {499-506}, doi = {10.1111/j.1550-7408.2006.00133.x}, pmid = {17123414}, issn = {1066-5234}, mesh = {Alphaproteobacteria/*classification/genetics ; Animals ; Paramecium/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/*analysis/genetics ; *Symbiosis ; }, abstract = {Bacterial endosymbionts of protozoa were often described as new species by protozoologists mainly on the basis of few morphological characters and partly by host specificity. Many of these species have never been validated by prokaryotic microbiologists whose taxonomic rules are quite different from those of protozoologists, who use the Zoological Code of Nomenclature. "Caedibacter macronucleorum"Fokin and Görtz 1993, an endosymbiont of Paramecium duboscqui, belongs to this category. Here we provide the molecular characterization of this organism and of its host P. duboscqui strain Ku4-8. Bacterial 16S rRNA gene sequence analysis proved that "C. macronucleorum" belongs to the Alphaproteobacteria. It is closely related to Caedibacter caryophilus but not to Caedibacter taeniospiralis, which belongs to the Gammaproteobacteria. "Caedibacter macronucleorum" and C. caryophilus 16S rRNA genes show a similarity value of 99%. This high 16S rRNA sequence similarity and the lack of a specific oligonucleotide probe for distinguishing the two endosymbionts do not allow validating "C. macronucleorum" as a provisional taxon (Candidatus). Nevertheless, "C. macronucleorum" and C. caryophilus can be easily discriminated on the basis of a highly variable stretch of nucleotides that interrupts the 16S rRNA genes of both organisms.}, }
@article {pmid17122400, year = {2007}, author = {Partida-Martinez, LP and de Looss, CF and Ishida, K and Ishida, M and Roth, M and Buder, K and Hertweck, C}, title = {Rhizonin, the first mycotoxin isolated from the zygomycota, is not a fungal metabolite but is produced by bacterial endosymbionts.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {3}, pages = {793-797}, pmid = {17122400}, issn = {0099-2240}, mesh = {Burkholderia/genetics/*growth &amp; development/*metabolism/ultrastructure ; Chromatography, High Pressure Liquid ; Cytosol/microbiology ; Magnetic Resonance Spectroscopy ; Molecular Sequence Data ; Mycelium/ultrastructure ; Mycotoxins/chemistry/*metabolism ; Peptides, Cyclic/chemistry/*metabolism ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rhizopus/*growth &amp; development/metabolism/ultrastructure ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Rhizonin is a hepatotoxic cyclopeptide isolated from cultures of a fungal Rhizopus microsporus strain that grew on moldy ground nuts in Mozambique. Reinvestigation of this fungal strain by a series of experiments unequivocally revealed that this "first mycotoxin from lower fungi" is actually not produced by the fungus. PCR experiments and phylogenetic studies based on 16S rRNA gene sequences revealed that the fungus is associated with bacteria belonging to the genus Burkholderia. By transmission electron microscopy, the bacteria were localized within the fungal cytosol. Toxin production and the presence of the endosymbionts were correlated by curing the fungus with an antibiotic, yielding a nonproducing, symbiont-free phenotype. The final evidence for a bacterial biogenesis of the toxin was obtained by the successful fermentation of the endosymbiotic bacteria in pure culture and isolation of rhizonin A from the broth. This finding is of particular interest since Rhizopus microsporus and related Rhizopus species are frequently used in food preparations such as tempeh and sufu.}, }
@article {pmid17119612, year = {2005}, author = {Puttaraju, HP and Prakash, BM}, title = {Effects of Wolbachia in the uzifly, Exorista sorbillans, a parasitoid of the silkworm, Bombyx mori.}, journal = {Journal of insect science (Online)}, volume = {5}, number = {}, pages = {30}, pmid = {17119612}, issn = {1536-2442}, mesh = {Animals ; Bombyx/*parasitology ; Diptera/*microbiology ; Dose-Response Relationship, Drug ; Female ; Male ; Oxytetracycline/pharmacology ; Reproduction ; Sex Ratio ; Wolbachia/drug effects/*physiology ; }, abstract = {The uzifly, Exorista sorbillans (Diptera: Tachinidae), a parasitoid of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), harbours Wolbachia (Rickettsia) endosymbionts. Administration of 0.05 mg/ml oxytetracycline to the adult uziflies removed Wolbachia endosymbionts and resulted in different reproductive disorders, such as i) reduction in fecundity of uninfected females, ii) cytoplasmic incompatibility in crosses between infected males and uninfected females, iii) sterility in the crosses between both males and females from uninfected populations, and iv) sex-ratio distortion in uninfected females irrespective of the presence of Wolbachia in males. However, tetracycline treatment did not have much effect on longevity of the uzifly. These results suggest that the interaction of Wolbachia with its uzifly host is one of mutual symbiosis as it controls the reproductive physiology of its hosts.}, }
@article {pmid17114724, year = {2006}, author = {Eremeeva, ME and Oliveira, A and Robinson, JB and Ribakova, N and Tokarevich, NK and Dasch, GA}, title = {Prevalence of bacterial agents in Ixodes persulcatus ticks from the Vologda Province of Russia.}, journal = {Annals of the New York Academy of Sciences}, volume = {1078}, number = {}, pages = {291-298}, doi = {10.1196/annals.1374.054}, pmid = {17114724}, issn = {0077-8923}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Base Sequence ; Boutonneuse Fever/epidemiology ; DNA, Bacterial/genetics/isolation &amp; purification ; Ehrlichia/genetics/isolation &amp; purification ; Geography ; Humans ; Ixodes/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Rickettsia Infections/*epidemiology ; Rickettsiaceae/genetics/*isolation &amp; purification ; Russia/epidemiology ; Symbiosis ; }, abstract = {The prevalence of rickettsiae, ehrlichiae, and the rickettsia-like endosymbiont called Montezuma relative to that of Borrelia was determined in questing Ixodes persulcatus (I. persulcatus) ticks collected in 2002-2003 from Vologda Province, Russia. Ehrlichia muris, Anaplasma phagocytophilum, Montezuma, and new spotted fever group rickettsiae were detected by polymerase chain reaction (PCR) for the first time in this area. The rickettsiae were all Candidatus Rickettsia tarasevichiae, the furthest west this organism has been detected. After Borrelia, Montezuma was the agent most frequently detected; it may be present throughout the distribution of I. persulcatus in Russia. Ehrlichiae and rickettsiae frequently share the same tick host with Borrelia burgdorferi sensu lato so cotransmission and mixed infections in vertebrate hosts, including humans, may occur.}, }
@article {pmid17113827, year = {2007}, author = {Pfarr, KM and Hoerauf, A}, title = {A niche for Wolbachia.}, journal = {Trends in parasitology}, volume = {23}, number = {1}, pages = {5-7}, doi = {10.1016/j.pt.2006.11.002}, pmid = {17113827}, issn = {1471-4922}, mesh = {Animals ; Arthropods/*microbiology ; Drosophila/microbiology ; Female ; Nematoda/*microbiology ; Phenotype ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia are endosymbionts of arthropods and filarial nematodes. Arthropods infected with these endobacteria display altered reproductive phenotypes, including cytoplasmic incompatibility and sex-ratio distortion. In nematodes, the endobacteria are essential for embryogenesis and worm survival. Wolbachia are transmitted vertically from mother to progeny, and Frydman et al. recently showed that, after transfer to uninfected Drosophila, Wolbachia rapidly accumulate in the somatic stem cell niche. From this location, the endobacteria might enter the developing oocytes and infect the progeny.}, }
@article {pmid17113100, year = {2007}, author = {de Avelar, DM and Bussolotti, AS and do Carmo A Ramos, M and Linardi, PM}, title = {Endosymbionts of Ctenocephalides felis felis (Siphonaptera: Pulicidae) obtained from dogs captured in Belo Horizonte, Minas Gerais, Brazil.}, journal = {Journal of invertebrate pathology}, volume = {94}, number = {2}, pages = {149-152}, doi = {10.1016/j.jip.2006.10.001}, pmid = {17113100}, issn = {0022-2011}, mesh = {Animals ; Brazil ; Cestoda/pathogenicity/physiology ; Climate ; Dog Diseases/*parasitology ; Dogs ; Ectoparasitic Infestations/parasitology/*veterinary ; Eukaryota/pathogenicity/physiology ; Female ; Host-Parasite Interactions ; Male ; Seasons ; Siphonaptera/*parasitology ; *Symbiosis ; }, abstract = {Specimens of fleas Ctenocephalides felis felis (1052 female symbol/448 male symbol), obtained from 150 dogs in Centro de Controle de Zoonoses de Belo Horizonte, Minas Gerais, Brazil, were dissected and examined for endosymbionts. Three protozoan, Nolleria pulicis, a gregarine (Actinocephalidae) and Leptomonas sp., together with one cestode, Dipylidium caninum were identified. Infections by N. pulicis and Leptomonas sp. occurred mainly in the warm-rainy period. The prevalence and distribution of these endosymbionts in fleas derived from Brazil and South America, and the their variation according to sex and season, are reported for the first time.}, }
@article {pmid17110309, year = {2006}, author = {Gergely, P and Perl, A and Poór, G}, title = {Possible pathogenic nature of the recently discovered TT virus: does it play a role in autoimmune rheumatic diseases?.}, journal = {Autoimmunity reviews}, volume = {6}, number = {1}, pages = {5-9}, doi = {10.1016/j.autrev.2006.03.002}, pmid = {17110309}, issn = {1568-9972}, support = {F05 TW05421/TW/FIC NIH HHS/United States ; R01 AI48079/AI/NIAID NIH HHS/United States ; }, mesh = {Autoimmune Diseases/etiology/immunology/*virology ; DNA Virus Infections/*diagnosis/epidemiology ; Humans ; Rheumatic Diseases/*etiology/*virology ; Torque teno virus/genetics/*isolation &amp; purification ; }, abstract = {Pathogenesis of viral origin has long been suggested in autoimmune rheumatic diseases. Beside the well-defined virus induced transient or chronic rheumatic diseases often resembling systemic autoimmune disorders such as rheumatoid arthritis, viruses can contribute to disease pathogenesis by several different pathomechanisms. TT virus is a recently discovered virus of extremely high genetic diversity which commonly infects humans. Despite accumulated evidence on the biological characteristics of TTV, its pathogenicity is still in question; many consider TTV as a harmless endosymbiont. The recent paper overviews the biology of TT virus and investigates the hypothesis that TTV might have a causative role in human diseases with special attention to the possibility that TTV might trigger autoimmunity in rheumatic disorders.}, }
@article {pmid17108184, year = {2007}, author = {Khachane, AN and Timmis, KN and Martins dos Santos, VA}, title = {Dynamics of reductive genome evolution in mitochondria and obligate intracellular microbes.}, journal = {Molecular biology and evolution}, volume = {24}, number = {2}, pages = {449-456}, doi = {10.1093/molbev/msl174}, pmid = {17108184}, issn = {0737-4038}, mesh = {Base Composition ; Biological Evolution ; Buchnera/*genetics ; DNA, Mitochondrial ; DNA, Ribosomal/genetics ; *Evolution, Molecular ; Extrachromosomal Inheritance ; Genome ; *Genome, Bacterial ; Mitochondria/*genetics ; Models, Genetic ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Reductive evolution in mitochondria and obligate intracellular microbes has led to a significant reduction in their genome size and guanine plus cytosine content (GC). We show that genome shrinkage during reductive evolution in prokaryotes follows an exponential decay pattern and provide a method to predict the extent of this decay on an evolutionary timescale. We validated predictions by comparison with estimated extents of genome reduction known to have occurred in mitochondria and Buchnera aphidicola, through comparative genomics and by drawing on available fossil evidences. The model shows how the mitochondrial ancestor would have quickly shed most of its genome, shortly after its incorporation into the protoeukaryotic cell and prior to codivergence subsequent to the split of eukaryotic lineages. It also predicts that the primary rickettsial parasitic event would have occurred between 180 and 425 million years ago (MYA), an event of relatively recent evolutionary origin considering the fact that Rickettsia and mitochondria evolved from a common alphaproteobacterial ancestor. This suggests that the symbiotic events of Rickettsia and mitochondria originated at different time points. Moreover, our model results predict that the ancestor of Wigglesworthia glossinidia brevipalpis, dated around the time of origin of its symbiotic association with the tsetse fly (50-100 MYA), was likely to have been an endosymbiont itself, thus supporting an earlier proposition that Wigglesworthia, which is currently a maternally inherited primary endosymbiont, evolved from a secondary endosymbiont.}, }
@article {pmid17107559, year = {2006}, author = {Davidov, Y and Huchon, D and Koval, SF and Jurkevitch, E}, title = {A new alpha-proteobacterial clade of Bdellovibrio-like predators: implications for the mitochondrial endosymbiotic theory.}, journal = {Environmental microbiology}, volume = {8}, number = {12}, pages = {2179-2188}, doi = {10.1111/j.1462-2920.2006.01101.x}, pmid = {17107559}, issn = {1462-2912}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification ; Bdellovibrio/classification/genetics/*isolation &amp; purification ; *Biological Evolution ; DNA, Mitochondrial/*physiology ; Mitochondria/*classification/physiology ; Molecular Sequence Data ; Phylogeny ; Prokaryotic Cells/cytology ; RNA, Ribosomal, 16S ; *Soil Microbiology ; Symbiosis/*physiology ; }, abstract = {Bdellovibrio-and-like organisms (BALOs) are peculiar, ubiquitous, small-sized, highly motile Gram-negative bacteria that are obligatory predators of other bacteria. Typically, these predators invade the periplasm of their prey where they grow and replicate. To date, BALOs constitute two highly diverse families affiliated with the delta-proteobacteria class. In this study, Micavibrio spp., a BALO lineage of epibiotic predators, were isolated from soil. These bacteria attach to digest and grow at the expense of other prokaryotes, much like other BALOs. Multiple phylogenetic analyses based on six genes revealed that they formed a deep branch within the alpha-proteobacteria, not affiliated with any of the alpha-proteobacterial orders. The presence of BALOs deep among the alpha-proteobacteria suggests that their peculiar mode of parasitism maybe an ancestral character in this proteobacterial class. The origin of the mitochondrion from an alpha-proteobacterium endosymbiont is strongly supported by molecular phylogenies. Accumulating data suggest that the endosymbiont's host was also a prokaryote. As prokaryotes are unable to phagocytose, the means by which the endosymbiont gained access into its host remains mysterious. We here propose a scenario based on the BALO feeding-mode to hypothesize a mechanism at play at the origin of the mitochondrial endosymbiosis.}, }
@article {pmid17099847, year = {2007}, author = {Nyati, S and Beck, A and Honegger, R}, title = {Fine structure and phylogeny of green algal photobionts in the microfilamentous genus Psoroglaena (Verrucariaceae, lichen-forming ascomycetes).}, journal = {Plant biology (Stuttgart, Germany)}, volume = {9}, number = {3}, pages = {390-399}, doi = {10.1055/s-2006-924654}, pmid = {17099847}, issn = {1435-8603}, mesh = {Ascomycota/*growth &amp; development ; Chlorophyta/classification/*genetics/ultrastructure ; DNA, Algal/chemistry/genetics ; Lichens/microbiology ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Photosynthesis ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal/genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {According to the literature the microfilamentous thalli of lichen-forming ascomycetes of the genus Psoroglaena are assumed to harbour vivid green "prochlorophyte" cyanobacterial photobionts. As this would be the first report of terrestrial "prochlorophytes" we investigated the fine structure and two molecular markers (SSU rDNA and rbcL) of the photobionts of P. stigonemoides (Orange) Henssen and P. epiphylla Lücking. Both Psoroglaena spp. had unicellular green algal photobionts, representatives of the Trebouxiophyceae. The photobiont of P. stigonemoides is closely related to the non-symbiotic auxenochlorella protothecoides and to a Chlorella endosymbiont of the freshwater polyp Hydra viridis. The putative photobiont of P. epiphylla may be related to Chlorella luteoviridis, C. saccharophila, and a Pseudochlorella isolate. In contrast to other microfilamentous lichens, which derive their shape from filamentous green algae or cyanobacterial colonies overgrown and ensheathed by the fungal partner, Psoroglaena mycobionts position their unicellular photobiont in uni- or multiseriate rows which strongly resemble the situation in filamentous cyanobacterial colonies.}, }
@article {pmid17098378, year = {2007}, author = {Gómez-Valero, L and Silva, FJ and Christophe Simon, J and Latorre, A}, title = {Genome reduction of the aphid endosymbiont Buchnera aphidicola in a recent evolutionary time scale.}, journal = {Gene}, volume = {389}, number = {1}, pages = {87-95}, doi = {10.1016/j.gene.2006.10.001}, pmid = {17098378}, issn = {0378-1119}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; Buchnera/*genetics ; Calibration ; DNA, Mitochondrial/genetics ; *Evolution, Molecular ; *Genome, Bacterial ; Geography ; Haplotypes ; Mutation/genetics ; Nucleotides/genetics ; Phylogeny ; Symbiosis/*genetics ; Time Factors ; }, abstract = {Genome reduction, a typical feature of symbiotic bacteria, was analyzed in the last stages of evolution of Buchnera aphidicola, the primary aphid endosymbiont, in two neutrally evolving regions: the pseudogene cmk and an intergenic region. These two regions were examined in endosymbionts from several lineages of their aphid host Rhopalosiphum padi, and different species of the same genus, whose divergence times ranged from 0.62 to 19.51 million years. Estimates of nucleotide substitution rates were between 4.3 and 6.7x10(-9) substitution/site/year, with G or C nucleotides being substituted around four times more frequently than A or T. Two different types of indel events were detected, of which many were small (1-10 nt) but one was large (about 200 nucleotides). With respect to the large one and considering the proportion and size of the deletions and insertions, the reduction rate was 1.3x10(-8) lost nucleotides/site/year. We propose a stepwise scenario for the last stages of evolution in B. aphidicola: together with a very slow and gradual degradation, considerable indels would punctually emerge. The only restriction to large deletion fixation is that the lost fragment does not contain essential genes.}, }
@article {pmid17085709, year = {2007}, author = {Jasinskas, A and Zhong, J and Barbour, AG}, title = {Highly prevalent Coxiella sp. bacterium in the tick vector Amblyomma americanum.}, journal = {Applied and environmental microbiology}, volume = {73}, number = {1}, pages = {334-336}, pmid = {17085709}, issn = {0099-2240}, support = {U54 AI065359/AI/NIAID NIH HHS/United States ; AI 065359/AI/NIAID NIH HHS/United States ; CI 00017-03/CI/NCPDCID CDC HHS/United States ; }, mesh = {Animals ; Arachnid Vectors/*microbiology ; *Coxiella/classification/genetics/growth &amp; development/isolation &amp; purification ; Female ; Gene Library ; Ixodidae/*microbiology ; Prevalence ; RNA, Bacterial/analysis/genetics ; Rickettsia/classification/genetics/isolation &amp; purification ; *Symbiosis ; }, abstract = {Laboratory-reared and field-collected Amblyomma americanum ticks were hosts of a Coxiella sp. and a Rickettsia sp. While the Coxiella sp. was detected in 50 of 50 field-collected ticks, the Rickettsia sp. was absent from 32% of ticks. The Coxiella sp. showed evidence of a reduced genome and may be an obligate endosymbiont.}, }
@article {pmid17085684, year = {2006}, author = {Stegemann, S and Bock, R}, title = {Experimental reconstruction of functional gene transfer from the tobacco plastid genome to the nucleus.}, journal = {The Plant cell}, volume = {18}, number = {11}, pages = {2869-2878}, pmid = {17085684}, issn = {1040-4651}, mesh = {Base Sequence ; Cell Nucleus/*metabolism ; Chromosome Segregation ; Chromosomes, Plant/metabolism ; Crosses, Genetic ; Drug Resistance ; Gene Rearrangement ; *Gene Transfer Techniques ; *Genes, Plant ; Genome, Plant/*genetics ; Molecular Sequence Data ; Plastids/*metabolism ; RNA 3' End Processing/genetics ; RNA, Messenger/genetics/metabolism ; Selection, Genetic ; Tobacco/*genetics ; Transcriptional Activation ; }, abstract = {Eukaryotic cells arose through the uptake of free-living bacteria by endosymbiosis and their gradual conversion into organelles (plastids and mitochondria). Capture of the endosymbionts was followed by massive translocation of their genes to the genome of the host cell. How genes were transferred from the (prokaryotic) organellar genome to the (eukaryotic) nuclear genome and how the genes became functional in their new eukaryotic genetic environment is largely unknown. Here, we report the successful experimental reconstruction of functional gene transfer between an organelle and the nucleus, a process that normally occurs only on large evolutionary timescales. In consecutive genetic screens, we first transferred a chloroplast genome segment to the nucleus and then selected for gene activation in the nuclear genome. We show that DNA-mediated gene transfer can give rise to functional nuclear genes if followed by suitable rearrangements in the nuclear genome. Acquisition of gene function involves (1) transcriptional activation by capture of the promoter of an upstream nuclear gene and (2) utilization of AT-rich noncoding sequences downstream of the plastid gene as RNA cleavage and polyadenylation sites. Our results reveal the molecular mechanisms of how organellar DNA transferred to the nucleus gives rise to functional genes and reproduce in the laboratory a key process in the evolution of eukaryotic cells.}, }
@article {pmid17082386, year = {2006}, author = {Sassera, D and Beninati, T and Bandi, C and Bouman, EAP and Sacchi, L and Fabbi, M and Lo, N}, title = {'Candidatus Midichloria mitochondrii', an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {56}, number = {Pt 11}, pages = {2535-2540}, doi = {10.1099/ijs.0.64386-0}, pmid = {17082386}, issn = {1466-5026}, mesh = {Alphaproteobacteria/*classification/*isolation &amp; purification/physiology/ultrastructure ; Animals ; Cytoplasm/microbiology ; DNA Gyrase/genetics ; DNA, Bacterial/chemistry/genetics ; Female ; In Situ Hybridization ; Ixodes/*microbiology/ultrastructure ; Male ; Microscopy, Electron, Transmission ; Mitochondria/*microbiology ; Mitochondrial Membranes/microbiology ; Molecular Sequence Data ; Ovary/cytology/microbiology ; Phylogeny ; Sequence Analysis, DNA ; Sequence Homology ; *Symbiosis ; }, abstract = {An intracellular bacterium with the unique ability to enter mitochondria exists in the European vector of Lyme disease, the hard tick Ixodes ricinus. Previous phylogenetic analyses based on 16S rRNA gene sequences suggested that the bacterium formed a divergent lineage within the Rickettsiales (Alphaproteobacteria). Here, we present additional phylogenetic evidence, based on the gyrB gene sequence, that confirms the phylogenetic position of the bacterium. Based on these data, as well as electron microscopy (EM), in situ hybridization and other observations, we propose the name 'Candidatus Midichloria mitochondrii' for this bacterium. The symbiont appears to be ubiquitous in females of I. ricinus across the tick's distribution, while lower prevalence is observed in males (44%). Based on EM and in situ hybridization studies, the presence of 'Candidatus M. mitochondrii' in females appears to be restricted to ovarian cells. The bacterium was found to be localized both in the cytoplasm and in the intermembrane space of the mitochondria of ovarian cells. 'Candidatus M. mitochondrii' is the first bacterium to be identified that resides within animal mitochondria.}, }
@article {pmid17054489, year = {2006}, author = {van Oppen, MJ and Gates, RD}, title = {Conservation genetics and the resilience of reef-building corals.}, journal = {Molecular ecology}, volume = {15}, number = {13}, pages = {3863-3883}, doi = {10.1111/j.1365-294X.2006.03026.x}, pmid = {17054489}, issn = {0962-1083}, mesh = {Animals ; Anthozoa/*genetics/physiology ; *Biological Evolution ; Biomarkers ; Chimera ; Conservation of Natural Resources ; Genetic Variation ; *Genetics, Population ; Marine Biology ; }, abstract = {Coral reefs have suffered long-term decline due to a range of anthropogenic disturbances and are now also under threat from climate change. For appropriate management of these vulnerable and valuable ecosystems it is important to understand the factors and processes that determine their resilience and that of the organisms inhabiting them, as well as those that have led to existing patterns of coral reef biodiversity. The scleractinian (stony) corals deposit the structural framework that supports and promotes the maintenance of biological diversity and complexity of coral reefs, and as such, are major components of these ecosystems. The success of reef-building corals is related to their obligate symbiotic association with dinoflagellates of the genus Symbiodinium. These one-celled algal symbionts (zooxanthellae) live in the endodermal tissues of their coral host, provide most of the host's energy budget and promote rapid calcification. Furthermore, zooxanthellae are the main primary producers on coral reefs due to the oligotrophic nature of the surrounding waters. In this review paper, we summarize and critically evaluate studies that have employed genetics and/or molecular biology in examining questions relating to the evolution and ecology of reef-building corals and their algal endosymbionts, and that bear relevance to coral reef conservation. We discuss how these studies can focus future efforts, and examine how these approaches enhance our understanding of the resilience of reef-building corals.}, }
@article {pmid17044263, year = {2006}, author = {Szklarzewicz, T and Kedra, K and Niznik, S}, title = {Ultrastructure and transovarial transmission of endosymbiotic microorganisms in Palaeococcus fuscipennis (Burmeister) (Insecta, Hemiptera, Coccinea: Monophlebidae).}, journal = {Folia biologica}, volume = {54}, number = {1-2}, pages = {69-74}, pmid = {17044263}, issn = {0015-5497}, mesh = {Animals ; Female ; Hemiptera/*microbiology/*ultrastructure ; Ovary/*microbiology/*ultrastructure ; }, abstract = {Ovaries ofPalaeococcus fuscipennis (Burmeister) are accompanied by large organs termed bacteriomes which are composed of large cells termed bacteriocytes. Each bacteriocyte is surrounded with small epithelial cells. The bacteriocyte cytoplasm is tightly packed with pleomorphic bacteria, whereas in epithelial cells small coccoid microorganisms are present. The number of coccoid bacteria is significantly lower than pleomorphic bacteria. The ovarioles containing choriogenic oocytes are invaded both by pleomorphic as well by coccoid bacteria. Microorganisms traverse the follicular epithelium and enter the perivitelline space. During advanced choriogenesis, endosymbionts are accumulated in the deep depression of the oocyte. Bacteria do not enter the ooplasm until the end of oocyte growth.}, }
@article {pmid17038625, year = {2006}, author = {Pérez-Brocal, V and Gil, R and Ramos, S and Lamelas, A and Postigo, M and Michelena, JM and Silva, FJ and Moya, A and Latorre, A}, title = {A small microbial genome: the end of a long symbiotic relationship?.}, journal = {Science (New York, N.Y.)}, volume = {314}, number = {5797}, pages = {312-313}, doi = {10.1126/science.1130441}, pmid = {17038625}, issn = {1095-9203}, mesh = {Amino Acids/biosynthesis ; Animals ; Aphids/*microbiology/physiology ; Base Pairing ; Buchnera/*genetics/metabolism/physiology ; Chromosomes, Bacterial/genetics ; Evolution, Molecular ; Genes, Bacterial ; *Genome, Bacterial ; Molecular Sequence Data ; Sequence Analysis, DNA ; Serratia/genetics/metabolism/physiology ; *Symbiosis ; Tryptophan/biosynthesis ; }, abstract = {Intracellular bacteria are characterized by genome reduction. The 422,434-base pair genome of Buchnera aphidicola BCc, primary endosymbiont of the aphid Cinara cedri, is approximately 200 kilobases smaller than the previously sequenced B. aphidicola genomes. B. aphidicola BCc has lost most metabolic functions, including the ability to synthesize the essential amino acid tryptophan and riboflavin. In addition, most retained genes are evolving rapidly. Possibly, B. aphidicola BCc is losing its symbiotic capacity and is being complemented (and might be replaced) by the highly abundant coexisting secondary symbiont.}, }
@article {pmid17038615, year = {2006}, author = {Nakabachi, A and Yamashita, A and Toh, H and Ishikawa, H and Dunbar, HE and Moran, NA and Hattori, M}, title = {The 160-kilobase genome of the bacterial endosymbiont Carsonella.}, journal = {Science (New York, N.Y.)}, volume = {314}, number = {5797}, pages = {267}, doi = {10.1126/science.1134196}, pmid = {17038615}, issn = {1095-9203}, mesh = {Amino Acids/biosynthesis ; Animals ; Base Composition ; Chromosomes, Bacterial ; DNA, Bacterial/chemistry/genetics ; Gammaproteobacteria/*genetics/physiology ; *Genes, Bacterial ; Genes, Overlapping ; Genes, rRNA ; *Genome, Bacterial ; Hemiptera/genetics/*microbiology/physiology ; Molecular Sequence Data ; Open Reading Frames ; RNA, Transfer/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Previous studies have suggested that the minimal cellular genome could be as small as 400 kilobases. Here, we report the complete genome sequence of the psyllid symbiont Carsonella ruddii, which consists of a circular chromosome of 159,662 base pairs, averaging 16.5% GC content. It is by far the smallest and most AT-rich bacterial genome yet characterized. The genome has a high coding density (97%) with many overlapping genes and reduced gene length. Genes for translation and amino acid biosynthesis are relatively well represented, but numerous genes considered essential for life are missing, suggesting that Carsonella may have achieved organelle-like status.}, }
@article {pmid17036209, year = {2006}, author = {Paraskevopoulos, C and Bordenstein, SR and Wernegreen, JJ and Werren, JH and Bourtzis, K}, title = {Toward a Wolbachia multilocus sequence typing system: discrimination of Wolbachia strains present in Drosophila species.}, journal = {Current microbiology}, volume = {53}, number = {5}, pages = {388-395}, pmid = {17036209}, issn = {0343-8651}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacterial Typing Techniques/*methods ; Drosophila/*microbiology ; Genetic Variation ; Recombination, Genetic ; *Sequence Analysis, DNA ; Wolbachia/*classification ; }, abstract = {Among the diverse maternally inherited symbionts in arthropods, Wolbachia are the most common and infect over 20% of all species. In a departure from traditional genotyping or phylogenetic methods relying on single Wolbachia genes, the present study represents an initial Multilocus Sequence Typing (MLST) analysis to discriminate closely related Wolbachia pipientis strains, and additional data on sequence diversity in Wolbachia. We report a new phylogenetic characterization of four genes (aspC, atpD, sucB, and pdhB), and provide an expanded analysis of markers described in previous studies (16S rDNA, ftsZ, groEL, dnaA, and gltA). MLST analysis of the bacterial strains present in 16 different Drosophila-Wolbachia associations detected four distinct clonal complexes that also corresponded to maximum-likelihood identified phylogenetic clades. Among the 16 associations analyzed, six could not be assigned to MLST clonal complexes and were also shown to be in conflict with relationships predicted by maximum-likelihood phylogenetic inferences. The results demonstrate the discriminatory power of MLST for identifying strains and clonal lineages of Wolbachia and provide a robust foundation for studying the ecology and evolution of this widespread endosymbiont.}, }
@article {pmid17032063, year = {2006}, author = {Jaenike, J and Dyer, KA and Cornish, C and Minhas, MS}, title = {Asymmetrical reinforcement and Wolbachia infection in Drosophila.}, journal = {PLoS biology}, volume = {4}, number = {10}, pages = {e325}, pmid = {17032063}, issn = {1545-7885}, mesh = {Animals ; *Biological Evolution ; Crosses, Genetic ; DNA, Mitochondrial/metabolism ; Drosophila/*genetics/*microbiology ; Female ; Genetic Variation ; *Hybridization, Genetic ; Male ; Molecular Sequence Data ; Reproduction ; Species Specificity ; Wolbachia/*pathogenicity ; }, abstract = {Reinforcement refers to the evolution of increased mating discrimination against heterospecific individuals in zones of geographic overlap and can be considered a final stage in the speciation process. One the factors that may affect reinforcement is the degree to which hybrid matings result in the permanent loss of genes from a species' gene pool. Matings between females of Drosophila subquinaria and males of D. recens result in high levels of offspring mortality, due to interspecific cytoplasmic incompatibility caused by Wolbachia infection of D. recens. Such hybrid inviability is not manifested in matings between D. recens females and D. subquinaria males. Here we ask whether the asymmetrical hybrid inviability is associated with a corresponding asymmetry in the level of reinforcement. The geographic ranges of D. recens and D. subquinaria were found to overlap across a broad belt of boreal forest in central Canada. Females of D. subquinaria from the zone of sympatry exhibit much stronger levels of discrimination against males of D. recens than do females from allopatric populations. In contrast, such reproductive character displacement is not evident in D. recens, consistent with the expected effects of unidirectional cytoplasmic incompatibility. Furthermore, there is substantial behavioral isolation within D. subquinaria, because females from populations sympatric with D. recens discriminate against allopatric conspecific males, whereas females from populations allopatric with D. recens show no discrimination against any conspecific males. Patterns of general genetic differentiation among populations are not consistent with patterns of behavioral discrimination, which suggests that the behavioral isolation within D. subquinaria results from selection against mating with Wolbachia-infected D. recens. Interspecific cytoplasmic incompatibility may contribute not only to post-mating isolation, an effect already widely recognized, but also to reinforcement, particularly in the uninfected species. The resulting reproductive character displacement not only increases behavioral isolation from the Wolbachia-infected species, but may also lead to behavioral isolation between populations of the uninfected species. Given the widespread occurrence of Wolbachia among insects, it thus appears that there are multiple ways by which these endosymbionts may directly and indirectly contribute to reproductive isolation and speciation.}, }
@article {pmid17030538, year = {2007}, author = {Lunn, JE}, title = {Compartmentation in plant metabolism.}, journal = {Journal of experimental botany}, volume = {58}, number = {1}, pages = {35-47}, doi = {10.1093/jxb/erl134}, pmid = {17030538}, issn = {0022-0957}, mesh = {Arabidopsis/cytology/metabolism ; Cell Compartmentation ; Chloroplasts/metabolism ; Coenzymes/biosynthesis ; Cytosol/metabolism ; Gene Expression Regulation, Plant ; Gluconeogenesis ; Glycolysis ; *Metabolic Networks and Pathways ; Photosynthesis ; *Plant Cells ; Plant Proteins/chemistry ; Plants/*metabolism ; Proteome/analysis ; Terpenes/metabolism ; Vitamins/biosynthesis ; }, abstract = {Cell fractionation and immunohistochemical studies in the last 40 years have revealed the extensive compartmentation of plant metabolism. In recent years, new protein mass spectrometry and fluorescent-protein tagging technologies have accelerated the flow of information, especially for Arabidopsis thaliana, but the intracellular locations of the majority of proteins in the plant proteome are still not known. Prediction programs that search for targeting information within protein sequences can be applied to whole proteomes, but predictions from different programs often do not agree with each other or, indeed, with experimentally determined results. The compartmentation of most pathways of primary metabolism is generally covered in plant physiology textbooks, so the focus here is mainly on newly discovered metabolic pathways in plants or pathways that have recently been revised. Ultimately, all of the pathways of plant metabolism are interconnected, and a major challenge facing plant biochemists is to understand the regulation and control of metabolic networks. One of the best-characterized networks links sucrose synthesis in the cytosol with photosynthetic CO(2) fixation and starch synthesis in the chloroplasts. One of the key features of this network is how the transport of pathway intermediates and signal metabolites across the chloroplast envelope conveys information between the two compartments, influencing the regulation of several enzymes to co-ordinate fluxes through the different pathways. It is widely accepted that chloroplasts and mitochondria originated from prokaryotic endosymbionts, and that new transporters and regulatory networks evolved to integrate metabolism in these organelles with the rest of the cell. Curiously, the present-day locations of many metabolic pathways within the cell often do not reflect their evolutionary origin, and there is evidence of extensive shuffling of enzymes and whole pathways between compartments during the evolution of plants.}, }
@article {pmid17028934, year = {2006}, author = {Stewart, FJ and Cavanaugh, CM}, title = {Bacterial endosymbioses in Solemya (Mollusca: Bivalvia)--model systems for studies of symbiont-host adaptation.}, journal = {Antonie van Leeuwenhoek}, volume = {90}, number = {4}, pages = {343-360}, doi = {10.1007/s10482-006-9086-6}, pmid = {17028934}, issn = {0003-6072}, mesh = {Adaptation, Physiological ; Animals ; Biological Evolution ; Bivalvia/anatomy &amp; histology/*microbiology/physiology ; Carbon/metabolism ; Gammaproteobacteria/*physiology/ultrastructure ; Nitrogen/metabolism ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Endosymbioses between chemosynthetic bacteria and marine invertebrates are remarkable biological adaptations to life in sulfide-rich environments. In these mutualistic associations, sulfur-oxidizing chemoautotrophic bacteria living directly within host cells both aid in the detoxification of toxic sulfide and fix carbon to support the metabolic needs of the host. Though best described for deep-sea vents and cold seeps, these symbioses are ubiquitous in shallow-water reducing environments. Indeed, considerable insight into sulfur-oxidizing endosymbioses in general comes from detailed studies of shallow-water protobranch clams in the genus Solemya. This review highlights the impressive body of work characterizing bacterial symbiosis in Solemya species, all of which are presumed to harbor endosymbionts. In particular, studies of the coastal Atlantic species Solemya velum and its larger Pacific congener Solemya reidi are the foundation for our understanding of the metabolism and physiology of marine bivalve symbioses, which are now known to occur in five families. Solemya velum, in particular, is an excellent model organism for symbiosis research. This clam can be collected easily from coastal eelgrass beds and maintained in laboratory aquaria for extended periods. In addition, the genome of the S. velum symbiont is currently being sequenced. The integration of genomic data with additional experimental analyses will help reveal the molecular basis of the symbiont-host interaction in Solemya, thereby complementing the wide array of research programs aimed at better understanding the diverse relationships between bacterial and eukaryotic cells.}, }
@article {pmid17028229, year = {2006}, author = {Rasgon, JL and Ren, X and Petridis, M}, title = {Can Anopheles gambiae be infected with Wolbachia pipientis? Insights from an in vitro system.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {12}, pages = {7718-7722}, pmid = {17028229}, issn = {0099-2240}, mesh = {Animals ; Anopheles/*microbiology ; Cell Line ; Immunocompetence ; In Situ Hybridization, Fluorescence ; Insect Vectors/microbiology ; Malaria/prevention &amp; control/transmission ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Wolbachia/classification/genetics/isolation &amp; purification/*pathogenicity ; }, abstract = {Wolbachia pipientis are maternally inherited endosymbionts associated with cytoplasmic incompatibility, a potential mechanism to drive transgenic traits into Anopheles populations for malaria control. W. pipientis infections are common in many mosquito genera but have never been observed in any Anopheles species, leading to the hypothesis that Anopheles mosquitoes are incapable of harboring infection. We used an in vitro system to evaluate the ability of Anopheles gambiae cells to harbor diverse W. pipientis infections. We successfully established W. pipientis infections (strains wRi and wAlbB) in the immunocompetent Anopheles gambiae cell line Sua5B. Infection was confirmed by PCR, antibiotic curing, DNA sequencing, and direct observation using fluorescence in situ hybridization. The infections were maintained at high passage rates for >30 passages. Our results indicate that there is no intrinsic genetic block to W. pipientis infection in A. gambiae cells, suggesting that establishment of in vivo W. pipientis infections in Anopheles mosquitoes may be feasible.}, }
@article {pmid17021229, year = {2006}, author = {Anselme, C and Vallier, A and Balmand, S and Fauvarque, MO and Heddi, A}, title = {Host PGRP gene expression and bacterial release in endosymbiosis of the weevil Sitophilus zeamais.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {10}, pages = {6766-6772}, pmid = {17021229}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*metabolism ; Bacterial Physiological Phenomena ; Carrier Proteins/genetics/*metabolism ; Gene Expression ; In Situ Hybridization, Fluorescence ; Reverse Transcriptase Polymerase Chain Reaction ; *Symbiosis ; Weevils/*microbiology/physiology ; }, abstract = {Intracellular symbiosis (endosymbiosis) with gram-negative bacteria is common in insects, yet little is known about how the host immune system perceives the endosymbionts and controls their growth and invasion without complete bacterial clearance. In this study, we have explored the expression of a peptidoglycan recognition protein gene of the weevil Sitophilus zeamais (wPGRP); an ortholog in Drosophila (i.e., PGRP-LB) was recently shown to downregulate the Imd pathway (A. Zaidman-Remy, M. Herve, M. Poidevin, S. Pili-Floury, M. S. Kim, D. Blanot, B. H. Oh, R. Ueda, D. Mengin-Lecreulx, and B. Lemaitre, Immunity 24:463-473, 2006). Insect challenges with bacteria have demonstrated that wPGRP is induced by gram-negative bacteria and that the level of induction depends on bacterial growth. Real-time reverse transcription-PCR quantification of the wPGRP gene transcript performed at different points in insect development has shown a high steady-state level in the bacteria-bearing organ (the bacteriome) of larvae and a high level of wPGRP up-regulation in the symbiotic nymphal phase. Concomitantly, during this stage fluorescence in situ hybridization has revealed an endosymbiont release from the host bacteriocytes. Together with the previously described high induction level of endosymbiont virulence genes at the nymphal phase (C. Dale, G. R. Plague, B. Wang, H. Ochman, and N. A. Moran, Proc. Natl. Acad. Sci. USA 99:12397-12402, 2002), these findings indicate that insect mutualistic relationships evolve through an interplay between bacterial virulence and host immune defense and that the host immunity engages the PGRP gene family in that interplay.}, }
@article {pmid17021218, year = {2006}, author = {Kageyama, D and Anbutsu, H and Watada, M and Hosokawa, T and Shimada, M and Fukatsu, T}, title = {Prevalence of a non-male-killing spiroplasma in natural populations of Drosophila hydei.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {10}, pages = {6667-6673}, pmid = {17021218}, issn = {0099-2240}, mesh = {Animals ; DNA, Bacterial/analysis ; Drosophila/*microbiology ; Male ; Phylogeny ; Spiroplasma/isolation &amp; purification/*physiology ; }, abstract = {Male-killing phenotypes are found in a variety of insects and are often associated with maternally inherited endosymbiotic bacteria. In several species of Drosophila, male-killing endosymbionts of the genus Spiroplasma have been found at low frequencies (0.1 to 3%). In this study, spiroplasma infection without causing male-killing was shown to be prevalent (23 to 66%) in Japanese populations of Drosophila hydei. Molecular phylogenetic analyses showed that D. hydei was infected with a single strain of spiroplasma, which was closely related to male-killing spiroplasmas from other Drosophila species. Artificial-transfer experiments suggested that the spiroplasma genotype rather than the host genotype was responsible for the absence of the male-killing phenotype. Infection densities of the spiroplasma in the natural host, D. hydei, and in the artificial host, Drosophila melanogaster, were significantly lower than those of the male-killing spiroplasma NSRO, which was in accordance with the hypothesis that a threshold infection density is needed for the spiroplasma-induced male-killing expression.}, }
@article {pmid17014490, year = {2006}, author = {DeChaine, EG and Bates, AE and Shank, TM and Cavanaugh, CM}, title = {Off-axis symbiosis found: Characterization and biogeography of bacterial symbionts of Bathymodiolus mussels from Lost City hydrothermal vents.}, journal = {Environmental microbiology}, volume = {8}, number = {11}, pages = {1902-1912}, doi = {10.1111/j.1462-2920.2005.01113.x}, pmid = {17014490}, issn = {1462-2912}, mesh = {Animals ; Atlantic Ocean ; Bacteria/*classification/genetics/*isolation &amp; purification/metabolism ; Bivalvia/*microbiology ; Chemoautotrophic Growth ; *Ecosystem ; Genes, rRNA ; Geography ; Phylogeny ; RNA, Ribosomal, 16S ; *Symbiosis ; Temperature ; }, abstract = {Organisms at hydrothermal vents inhabit discontinuous chemical 'islands' along mid-ocean ridges, a scenario that may promote genetic divergence among populations. The 2003 discovery of mussels at the Lost City Hydrothermal Field provided a means of evaluating factors that govern the biogeography of symbiotic bacteria in the deep sea. The unusual chemical composition of vent fluids, the remote location, and paucity of characteristic vent macrofauna at the site, raised the question of whether microbial symbioses existed at the extraordinary Lost City. If so, how did symbiotic bacteria therein relate to those hosted by invertebrates at the closest known hydrothermal vents along the Mid-Atlantic Ridge (MAR)? To answer these questions, we performed microscopic and molecular analyses on the bacteria found within the gill tissue of Bathymodiolus mussels (Mytilidae, Bathymodiolinae) that were discovered at the Lost City. Here we show that Lost City mussels harbour chemoautotrophic and methanotrophic endosymbionts simultaneously. Furthermore, populations of the chemoautotrophic symbionts from the Lost City and two sites along the MAR are genetically distinct from each other, which suggests spatial isolation of bacteria in the deep sea. These findings provide new insights into the processes that drive diversification of bacteria and evolution of symbioses at hydrothermal vents.}, }
@article {pmid17013599, year = {2006}, author = {O'Grady, SP and Dearing, MD}, title = {Isotopic insight into host-endosymbiont relationships in Liolaemid lizards.}, journal = {Oecologia}, volume = {150}, number = {3}, pages = {355-361}, pmid = {17013599}, issn = {0029-8549}, mesh = {Analysis of Variance ; Animals ; Argentina ; Body Weights and Measures ; Carbon Isotopes/metabolism ; *Food Chain ; Gastrointestinal Contents/chemistry ; Lizards/*metabolism/*parasitology ; Nematoda/*chemistry ; Nitrogen Isotopes/analysis ; *Symbiosis ; }, abstract = {Nitrogen isotopes have been widely used to investigate trophic levels in ecological systems. Isotopic enrichment of 2-5 per thousand occurs with trophic level increases in food webs. Host-parasite relationships deviate from traditional food webs in that parasites are minimally enriched relative to their hosts. Although this host-parasite enrichment pattern has been shown in multiple systems, few studies have used isotopic relationships to examine other potential symbioses. We examined the relationship between two gut-nematodes and their lizard hosts. One species, Physaloptera retusa, is a documented parasite in the stomach, whereas the relationship of the other species, Parapharyngodon riojensis (pinworms), to the host is putatively commensalistic or mutualistic. Based on the established trophic enrichments, we predicted that, relative to host tissue, parasitic nematodes would be minimally enriched (0-1 per thousand), whereas pinworms, either as commensals or mutualists, would be significantly enriched by 2-5 per thousand. We measured the (15)N values of food, digesta, gut tissue, and nematodes of eight lizard species in the family Liolaemidae. Parasitic worms were enriched 1+/-0.2 per thousand relative to host tissue, while the average enrichment value for pinworms relative to gut tissue was 6.7+/-0.2 per thousand. The results support previous findings that isotopic fractionation in a host-parasite system is lower than traditional food webs. Additionally, the larger enrichment of pinworms relative to known parasites suggests that they are not parasitic and may be several trophic levels beyond the host.}, }
@article {pmid17012281, year = {2006}, author = {Glanz, S and Bunse, A and Wimbert, A and Balczun, C and Kück, U}, title = {A nucleosome assembly protein-like polypeptide binds to chloroplast group II intron RNA in Chlamydomonas reinhardtii.}, journal = {Nucleic acids research}, volume = {34}, number = {18}, pages = {5337-5351}, pmid = {17012281}, issn = {1362-4962}, mesh = {Algal Proteins/classification/genetics/*metabolism ; Amino Acid Sequence ; Animals ; Binding Sites ; Chlamydomonas reinhardtii/*genetics/metabolism ; Chloroplasts/chemistry/*genetics ; *Introns ; Molecular Sequence Data ; Nuclear Proteins/genetics ; Nucleosomes/metabolism ; Peptides/genetics/metabolism ; Phylogeny ; RNA, Algal/chemistry/metabolism ; RNA, Messenger/metabolism ; RNA-Binding Proteins/classification/genetics/*metabolism ; Sequence Homology, Amino Acid ; Two-Hybrid System Techniques ; }, abstract = {In the unicellular green alga Chlamydomonas reinhardtii, the chloroplast-encoded tscA RNA is part of a tripartite group IIB intron, which is involved in trans-splicing of precursor mRNAs. We have used the yeast three-hybrid system to identify chloroplast group II intron RNA-binding proteins, capable of interacting with the tscA RNA. Of 14 candidate cDNAs, 13 encode identical polypeptides with significant homology to members of the nuclear nucleosome assembly protein (NAP) family. The RNA-binding property of the identified polypeptide was demonstrated by electrophoretic mobility shift assays using different domains of the tripartite group II intron as well as further chloroplast transcripts. Because of its binding to chloroplast RNA it was designated as NAP-like (cNAPL). In silico analysis revealed that the derived polypeptide carries a 46 amino acid chloroplast leader peptide, in contrast to nuclear NAPs. The chloroplast localization of cNAPL was demonstrated by laser scanning confocal fluorescence microscopy using different chimeric cGFP fusion proteins. Phylogenetic analysis shows that no homologues of cNAPL and its related nuclear counterparts are present in prokaryotic genomes. These data indicate that the chloroplast protein described here is a novel member of the NAP family and most probably has not been acquired from a prokaryotic endosymbiont.}, }
@article {pmid17011644, year = {2006}, author = {Léon, S and Goodman, JM and Subramani, S}, title = {Uniqueness of the mechanism of protein import into the peroxisome matrix: transport of folded, co-factor-bound and oligomeric proteins by shuttling receptors.}, journal = {Biochimica et biophysica acta}, volume = {1763}, number = {12}, pages = {1552-1564}, doi = {10.1016/j.bbamcr.2006.08.037}, pmid = {17011644}, issn = {0006-3002}, support = {R37 DK041737-15/DK/NIDDK NIH HHS/United States ; GM59844/GM/NIGMS NIH HHS/United States ; R37 DK041737/DK/NIDDK NIH HHS/United States ; R01 DK041737/DK/NIDDK NIH HHS/United States ; DK41737/DK/NIDDK NIH HHS/United States ; }, mesh = {Cytoplasm/physiology ; Humans ; Intracellular Membranes/metabolism ; *Models, Biological ; Peroxisomal Targeting Signal 2 Receptor ; Peroxisome-Targeting Signal 1 Receptor ; Peroxisomes/*metabolism ; Plant Proteins/metabolism ; *Protein Folding ; *Protein Transport ; Receptors, Cytoplasmic and Nuclear/*metabolism ; Saccharomyces cerevisiae Proteins/metabolism ; }, abstract = {Based on earlier suggestions that peroxisomes may have arisen from endosymbionts that later lost their DNA, it was expected that protein transport into this organelle would have parallels to systems found in other organelles of endosymbiont origin, such as mitochondria and chloroplasts. This review highlights three features of peroxisomal matrix protein import that make it unique in comparison with these other subcellular compartments - the ability of this organelle to transport folded, co-factor-bound and oligomeric proteins, the dynamics of the import receptors during the matrix protein import cycle and the existence of a peroxisomal quality-control pathway, which insures that the peroxisome membrane is cleared of cargo-free receptors.}, }
@article {pmid17004028, year = {2006}, author = {Loftis, AD and Reeves, WK and Szumlas, DE and Abbassy, MM and Helmy, IM and Moriarity, JR and Dasch, GA}, title = {Rickettsial agents in Egyptian ticks collected from domestic animals.}, journal = {Experimental &amp; applied acarology}, volume = {40}, number = {1}, pages = {67-81}, pmid = {17004028}, issn = {0168-8162}, mesh = {Animals ; Animals, Domestic/*parasitology ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; Egypt ; Female ; Male ; Polymerase Chain Reaction/veterinary ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/chemistry/genetics ; RNA, Ribosomal, 18S/chemistry/genetics ; Rickettsia/genetics/*isolation &amp; purification ; Rural Population ; Tick-Borne Diseases/*microbiology ; Ticks/*microbiology ; }, abstract = {To assess the presence of rickettsial pathogens in ticks from Egypt, we collected ticks from domestic and peridomestic animals between June 2002 and July 2003. DNA extracts from 1019 ticks were tested, using PCR and sequencing, for Anaplasma spp., Bartonella spp., Coxiella burnetii, Ehrlichia spp., and Rickettsia spp. Ticks included: 29 Argas persicus, 10 Hyalomma anatolicum anatolicum, 55 Hyalomma anatolicum excavatum, 174 Hyalomma dromedarii, 2 Hyalomma impeltatum, 3 Hyalomma marginatum rufipes, 55 unidentified nymphal Hyalomma, 625 Rhipicephalus (Boophilus) annulatus, 49 Rhipicephalus sanguineus, and 17 Rhipicephalus turanicus. Ticks were collected predominantly (>80%) from buffalo, cattle, and camels, with smaller numbers from chicken and rabbit sheds, sheep, foxes, a domestic dog, a hedgehog, and a black rat. We detected Anaplasma marginale, Coxiella burnetii, Rickettsia aeschlimannii, and four novel genotypes similar to: "Anaplasma platys," Ehrlichia canis, Ehrlichia spp. reported from Asian ticks, and a Rickettsiales endosymbiont of Ixodes ricinus.}, }
@article {pmid16990439, year = {2007}, author = {Rogers, MB and Gilson, PR and Su, V and McFadden, GI and Keeling, PJ}, title = {The complete chloroplast genome of the chlorarachniophyte Bigelowiella natans: evidence for independent origins of chlorarachniophyte and euglenid secondary endosymbionts.}, journal = {Molecular biology and evolution}, volume = {24}, number = {1}, pages = {54-62}, doi = {10.1093/molbev/msl129}, pmid = {16990439}, issn = {0737-4038}, mesh = {Animals ; Chlorophyta/*genetics/physiology ; Chloroplasts/*genetics ; Euglenida/*genetics/physiology ; *Genome ; Molecular Sequence Data ; Phylogeny ; RNA, Transfer/genetics ; *Symbiosis ; }, abstract = {Chlorarachniophytes are amoeboflagellate cercozoans that acquired a plastid by secondary endosymbiosis. Chlorarachniophytes are the last major group of algae for which there is no completely sequenced plastid genome. Here we describe the 69.2-kbp chloroplast genome of the model chlorarachniophyte Bigelowiella natans. The genome is highly reduced in size compared with plastids of other photosynthetic algae and is closer in size to genomes of several nonphotosynthetic plastids. Unlike nonphotosynthetic plastids, however, the B. natans chloroplast genome has not sustained a massive loss of genes, and it retains nearly all of the functional photosynthesis-related genes represented in the genomes of other green algae. Instead, the genome is highly compacted and gene dense. The genes are organized with a strong strand bias, and several unusual rearrangements and inversions also characterize the genome; notably, an inversion in the small-subunit rRNA gene, a translocation of 3 genes in the major ribosomal protein operon, and the fragmentation of the cluster encoding the large photosystem proteins PsaA and PsaB. The chloroplast endosymbiont is known to be a green alga, but its evolutionary origin and relationship to other primary and secondary green plastids has been much debated. A recent hypothesis proposes that the endosymbionts of chlorarachniophytes and euglenids share a common origin (the Cabozoa hypothesis). We inferred phylogenies using individual and concatenated gene sequences for all genes in the genome. Concatenated gene phylogenies show a relationship between the B. natans plastid and the ulvophyte-trebouxiophyte-chlorophyte clade of green algae to the exclusion of Euglena. The B. natans plastid is thus not closely related to that of Euglena, which suggests that plastids originated independently in these 2 groups and the Cabozoa hypothesis is false.}, }
@article {pmid16963554, year = {2006}, author = {Triplett, LR and Zhao, Y and Sundin, GW}, title = {Genetic differences between blight-causing Erwinia species with differing host specificities, identified by suppression subtractive hybridization.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {11}, pages = {7359-7364}, pmid = {16963554}, issn = {0099-2240}, mesh = {Bacterial Proteins/chemistry/genetics ; Base Sequence ; DNA, Bacterial/analysis ; Erwinia/*classification/*genetics/pathogenicity ; Erwinia amylovora/classification/growth &amp; development/pathogenicity ; Malus/*microbiology ; Nucleic Acid Hybridization/*methods ; Plant Diseases/*microbiology ; Pyrus/*microbiology ; Species Specificity ; }, abstract = {PCR-based subtractive hybridization was used to isolate sequences from Erwinia amylovora strain Ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: E. amylovora MR1, which is pathogenic only on Rubus spp.; Erwinia pyrifoliae Ep1/96, the causal agent of shoot blight of Asian pears; and Erwinia sp. strain Ejp556, the causal agent of bacterial shoot blight of pear in Japan. In total, six subtractive libraries were constructed and analyzed. Recovered sequences included type III secretion components, hypothetical membrane proteins, and ATP-binding proteins. In addition, we identified an Ea110-specific sequence with homology to a type III secretion apparatus component of the insect endosymbiont Sodalis glossinidius, as well as an Ep1/96-specific sequence with homology to the Yersinia pestis effector protein tyrosine phosphatase YopH.}, }
@article {pmid16957225, year = {2006}, author = {Zientz, E and Beyaert, I and Gross, R and Feldhaar, H}, title = {Relevance of the endosymbiosis of Blochmannia floridanus and carpenter ants at different stages of the life cycle of the host.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {9}, pages = {6027-6033}, pmid = {16957225}, issn = {0099-2240}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Ants/drug effects/growth &amp; development/*microbiology/physiology ; Base Sequence ; DNA, Bacterial/genetics ; Enterobacteriaceae/genetics/*physiology ; Gene Expression ; Genes, Bacterial ; Nitrogen/metabolism ; Social Behavior ; *Symbiosis/genetics/physiology ; Tyrosine/biosynthesis ; }, abstract = {Expression of several genes possibly involved in the symbiotic relationship between the obligate intracellular endosymbiont Blochmannia floridanus and its ant host Camponotus floridanus was investigated at different developmental stages of the host by real-time quantitative PCR. These included a set of genes related to nitrogen metabolism (ureC, ureF, glnA, and speB) as well as genes involved in the synthesis of the aromatic amino acid tyrosine (tyrA, aspC, and hisC). The overall transcriptional activity of Blochmannia was found to be quite low during early developmental stages and to increase steadily with host age. However, a concerted peak of gene expression related to nitrogen recycling could be detected around the entire process of pupation, while expression of biosynthesis pathways for aromatic amino acids was elevated only during a short phase in pupation. These data suggest an important role of certain metabolic functions for the symbiotic interactions of the bacteria and an individual host organism in early phases of development. General relevance of Blochmannia for its ant host was tested in fostering experiments with worker groups of Camponotus floridanus, and their success in raising pupae from first-instar larvae was used as a fitness measure. Groups treated with antibiotics had a significantly reduced success in raising the brood in comparison to untreated control groups, indicating that the symbiosis is relevant for the development of the entire colony.}, }
@article {pmid16950907, year = {2006}, author = {Weiss, BL and Mouchotte, R and Rio, RV and Wu, YN and Wu, Z and Heddi, A and Aksoy, S}, title = {Interspecific transfer of bacterial endosymbionts between tsetse fly species: infection establishment and effect on host fitness.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {11}, pages = {7013-7021}, pmid = {16950907}, issn = {0099-2240}, support = {T32AI07404/AI/NIAID NIH HHS/United States ; F32AI062680/AI/NIAID NIH HHS/United States ; AI51584/AI/NIAID NIH HHS/United States ; F32 AI062680/AI/NIAID NIH HHS/United States ; GM069449/GM/NIGMS NIH HHS/United States ; R01 AI051584/AI/NIAID NIH HHS/United States ; T32 AI007404/AI/NIAID NIH HHS/United States ; T01CT122306/CT/CIT NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; Enterobacteriaceae/genetics/*growth &amp; development/*pathogenicity ; Female ; Insect Vectors/classification/growth &amp; development/microbiology ; Phylogeny ; Polymerase Chain Reaction ; Species Specificity ; *Symbiosis ; Trypanosomiasis/prevention &amp; control/transmission ; Tsetse Flies/classification/*growth &amp; development/*microbiology ; }, abstract = {Tsetse flies (Glossina spp.) can harbor up to three distinct species of endosymbiotic bacteria that exhibit unique modes of transmission and evolutionary histories with their host. Two mutualist enterics, Wigglesworthia and Sodalis, are transmitted maternally to tsetse flies' intrauterine larvae. The third symbiont, from the genus Wolbachia, parasitizes developing oocytes. In this study, we determined that Sodalis isolates from several tsetse fly species are virtually identical based on a phylogenetic analysis of their ftsZ gene sequences. Furthermore, restriction fragment-length polymorphism analysis revealed little variation in the genomes of Sodalis isolates from tsetse fly species within different subgenera (Glossina fuscipes fuscipes and Glossina morsitans morsitans). We also examined the impact on host fitness of transinfecting G. fuscipes fuscipes and G. morsitans morsitans flies with reciprocal Sodalis strains. Tsetse flies cleared of their native Sodalis symbionts were successfully repopulated with the Sodalis species isolated from a different tsetse fly species. These transinfected flies effectively transmitted the novel symbionts to their offspring and experienced no detrimental fitness effects compared to their wild-type counterparts, as measured by longevity and fecundity. Quantitative PCR analysis revealed that transinfected flies maintained their Sodalis populations at densities comparable to those in flies harboring native symbionts. Our ability to transinfect tsetse flies is indicative of Sodalis ' recent evolutionary history with its tsetse fly host and demonstrates that this procedure may be used as a means of streamlining future paratransgenesis experiments.}, }
@article {pmid16950085, year = {2006}, author = {Yoon, HS and Reyes-Prieto, A and Melkonian, M and Bhattacharya, D}, title = {Minimal plastid genome evolution in the Paulinella endosymbiont.}, journal = {Current biology : CB}, volume = {16}, number = {17}, pages = {R670-2}, doi = {10.1016/j.cub.2006.08.018}, pmid = {16950085}, issn = {0960-9822}, mesh = {Animals ; *Biological Evolution ; Cyanobacteria/genetics ; Eukaryota/*genetics ; Gene Order ; Genome, Bacterial ; Genome, Protozoan ; Plastids/*genetics ; Symbiosis/*genetics ; Synechococcus/genetics ; Synteny ; }, }
@article {pmid16944340, year = {2006}, author = {Azanza, MP and Azanza, RV and Vargas, VM and Hedreyda, CT}, title = {Bacterial endosymbionts of Pyrodinium bahamense var. compressum.}, journal = {Microbial ecology}, volume = {52}, number = {4}, pages = {756-764}, pmid = {16944340}, issn = {0095-3628}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification/metabolism ; Chromatography, High Pressure Liquid ; Dinoflagellida/*microbiology ; Marine Toxins/analysis/toxicity ; Mice ; Philippines ; RNA, Ribosomal, 16S/genetics ; Saxitoxin/analysis/toxicity ; Symbiosis ; }, abstract = {The study presents evidence in support of the bacterial theory associated with the toxicity of Pyrodinium bahamense var. compressum. Bacterial endosymbionts from Philippine P. bahamense var. compressum strain Pbc MZRVA 042595 were isolated and identified via 16S rDNA sequence analysis. Taxonomic diversity of the identified culturable intracellular microbiota associated with Philippine P. bahamense var. compressum was established to be limited to the Phyla Proteobacteria, Actinobacteria, and Firmicutes. Major endosymbionts identified included Moraxella spp., Erythrobacter spp., and Bacillus spp., whereas Pseudomonas putida, Micrococcus spp., and Dietzia maris were identified as minor isolates. All identified strains except D. maris, P. putida, and Micrococcus spp. were shown to contain either saxitoxin or neo saxitoxin or both at levels < or =73 ng/10(7) bacterial cells based on high-performance liquid chromatography analysis. Paralytic shellfish poisoning-like physiologic reactions in test animals used in the mouse assay were recorded for the endosymbionts except for P. putida. The study is the first to elucidate the possible contribution of bacterial endosymbionts in the toxicity of P. bahamense var. compressum isolated in the Philippines.}, }
@article {pmid16939276, year = {2006}, author = {Scherlach, K and Partida-Martinez, LP and Dahse, HM and Hertweck, C}, title = {Antimitotic rhizoxin derivatives from a cultured bacterial endosymbiont of the rice pathogenic fungus Rhizopus microsporus.}, journal = {Journal of the American Chemical Society}, volume = {128}, number = {35}, pages = {11529-11536}, doi = {10.1021/ja062953o}, pmid = {16939276}, issn = {0002-7863}, mesh = {Animals ; Antimitotic Agents/chemistry/*isolation &amp; purification/pharmacology ; *Burkholderia/isolation &amp; purification/metabolism/pathogenicity ; Cell Proliferation/drug effects ; Cell Survival/drug effects ; Chromatography, High Pressure Liquid ; Fibroblasts/drug effects ; HeLa Cells ; Humans ; K562 Cells ; Macrolides/chemistry/*isolation &amp; purification/pharmacology ; Mice ; Microtubule Proteins/chemistry ; Molecular Structure ; Oryza/*microbiology ; *Rhizopus/isolation &amp; purification/metabolism/pathogenicity ; Structure-Activity Relationship ; *Symbiosis ; }, abstract = {The potent antimitotic polyketide macrolide rhizoxin, the causal agent of rice seedling blight, is not produced by the fungus Rhizopus microsporus, as has been believed for over two decades, but by endosymbiotic bacteria that reside within the fungal mycelium. Here we report the successful isolation and large-scale fermentation of the bacterial endosymbiont ("Burkholderia rhizoxina") in pure culture, which resulted in a significantly elevated (10x higher) production of antimitotics. In addition to several known rhizoxin derivatives, numerous novel natural and semisynthetic variants were isolated, and their structures were fully elucidated. Cell-based assays as well as tubulin binding experiments revealed that methylated seco-rhizoxin derivatives are 1000-10000 times more active than rhizoxin and thus rank among the most potent antiproliferative agents known to date. Furthermore, more stable didesepoxy rhizoxin analogues were obtained by efficiently inhibiting a putative P-450 monooxygenase involved in macrolide tailoring.}, }
@article {pmid16936055, year = {2006}, author = {Baldo, L and Dunning Hotopp, JC and Jolley, KA and Bordenstein, SR and Biber, SA and Choudhury, RR and Hayashi, C and Maiden, MC and Tettelin, H and Werren, JH}, title = {Multilocus sequence typing system for the endosymbiont Wolbachia pipientis.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {11}, pages = {7098-7110}, pmid = {16936055}, issn = {0099-2240}, mesh = {Alleles ; Animals ; Arthropods/classification/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/*genetics ; *Bacterial Typing Techniques ; DNA, Bacterial/analysis/isolation &amp; purification ; Genetic Variation ; Molecular Sequence Data ; Recombination, Genetic ; *Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Wolbachia/*classification/genetics/growth &amp; development ; }, abstract = {The eubacterial genus Wolbachia comprises one of the most abundant groups of obligate intracellular bacteria, and it has a host range that spans the phyla Arthropoda and Nematoda. Here we developed a multilocus sequence typing (MLST) scheme as a universal genotyping tool for Wolbachia. Internal fragments of five ubiquitous genes (gatB, coxA, hcpA, fbpA, and ftsZ) were chosen, and primers that amplified across the major Wolbachia supergroups found in arthropods, as well as other divergent lineages, were designed. A supplemental typing system using the hypervariable regions of the Wolbachia surface protein (WSP) was also developed. Thirty-seven strains belonging to supergroups A, B, D, and F obtained from singly infected hosts were characterized by using MLST and WSP. The number of alleles per MLST locus ranged from 25 to 31, and the average levels of genetic diversity among alleles were 6.5% to 9.2%. A total of 35 unique allelic profiles were found. The results confirmed that there is a high level of recombination in chromosomal genes. MLST was shown to be effective for detecting diversity among strains within a single host species, as well as for identifying closely related strains found in different arthropod hosts. Identical or similar allelic profiles were obtained for strains harbored by different insect species and causing distinct reproductive phenotypes. Strains with similar WSP sequences can have very different MLST allelic profiles and vice versa, indicating the importance of the MLST approach for strain identification. The MLST system provides a universal and unambiguous tool for strain typing, population genetics, and molecular evolutionary studies. The central database for storing and organizing Wolbachia bacterial and host information can be accessed at http://pubmlst.org/wolbachia/.}, }
@article {pmid16934288, year = {2006}, author = {Frati, F and Negri, I and Fanciulli, PP and Pellecchia, M and Dallai, R}, title = {Ultrastructural and molecular identification of a new Rickettsia endosymbiont in the springtail Onychiurus sinensis (Hexapoda, Collembola).}, journal = {Journal of invertebrate pathology}, volume = {93}, number = {3}, pages = {150-156}, doi = {10.1016/j.jip.2006.07.002}, pmid = {16934288}, issn = {0022-2011}, mesh = {Animals ; Biological Evolution ; Female ; Gonads/*microbiology/ultrastructure ; Insecta/*microbiology ; Likelihood Functions ; Male ; Microscopy, Electron, Transmission ; Phylogeny ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/genetics ; Rickettsia/*genetics/isolation &amp; purification/*ultrastructure ; Rickettsia Infections/genetics/*microbiology/pathology ; Soil ; *Symbiosis ; }, abstract = {In this paper we provide microscopic and molecular evidence for the presence of an endosymbiontic bacterium in male and female gonads of the soil arthropod Onychiurus sinensis. The sequence of the gene encoding for the 16S rRNA shows that the bacterium is a member of the genus Rickettsia, and some anomalies presumably associated with the presence of these microorganisms have been detected. Although the Rickettsia found in O. sinensis has the smallest genetic divergence with Rickettsia bellii, the phylogenetic analysis fails to find support for a sister-group relationship between these two species, rather suggesting that most Rickettsia species/strains isolated in various arthropods have rapidly evolved and diversified in what appears to be a sudden burst of evolution.}, }
@article {pmid16911042, year = {2006}, author = {Ventura, M and Canchaya, C and Zhang, Z and Bernini, V and Fitzgerald, GF and van Sinderen, D}, title = {How high G+C Gram-positive bacteria and in particular bifidobacteria cope with heat stress: protein players and regulators.}, journal = {FEMS microbiology reviews}, volume = {30}, number = {5}, pages = {734-759}, doi = {10.1111/j.1574-6976.2006.00031.x}, pmid = {16911042}, issn = {0168-6445}, mesh = {Actinobacteria/genetics/*physiology ; *Adaptation, Physiological ; Bacterial Proteins/physiology ; Bifidobacterium/genetics/*physiology ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; *Genes, Regulator ; Heat-Shock Proteins/physiology ; *Hot Temperature ; Molecular Chaperones/*physiology ; Regulon/physiology ; }, abstract = {The Actinobacteridae group of bacteria includes pathogens, plant commensals, endosymbionts as well as inhabitants of the gastrointestinal tract. For various reasons, these microorganisms represent a growing area of interest with respect to genomics, molecular biology and genetics. This review will discuss the current knowledge on the molecular players that allow actinobacteria to contend with heat stress, with an emphasis on bifidobacteria. We describe the principal molecular chaperones involved in heat stress. Temporal expression of heat-shock genes based on functional genomics in members of the Actinobacteridae group is also discussed, as well as the emerging molecular mechanisms controlling the heat-stress response.}, }
@article {pmid16907971, year = {2006}, author = {Koonin, EV}, title = {The origin of introns and their role in eukaryogenesis: a compromise solution to the introns-early versus introns-late debate?.}, journal = {Biology direct}, volume = {1}, number = {}, pages = {22}, pmid = {16907971}, issn = {1745-6150}, abstract = {BACKGROUND: Ever since the discovery of 'genes in pieces' and mRNA splicing in eukaryotes, origin and evolution of spliceosomal introns have been considered within the conceptual framework of the 'introns early' versus 'introns late' debate. The 'introns early' hypothesis, which is closely linked to the so-called exon theory of gene evolution, posits that protein-coding genes were interrupted by numerous introns even at the earliest stages of life's evolution and that introns played a major role in the origin of proteins by facilitating recombination of sequences coding for small protein/peptide modules. Under this scenario, the absence of spliceosomal introns in prokaryotes is considered to be a result of "genome streamlining". The 'introns late' hypothesis counters that spliceosomal introns emerged only in eukaryotes, and moreover, have been inserted into protein-coding genes continuously throughout the evolution of eukaryotes. Beyond the formal dilemma, the more substantial side of this debate has to do with possible roles of introns in the evolution of eukaryotes.<br><br>RESULTS: I argue that several lines of evidence now suggest a coherent solution to the introns-early versus introns-late debate, and the emerging picture of intron evolution integrates aspects of both views although, formally, there seems to be no support for the original version of introns-early. Firstly, there is growing evidence that spliceosomal introns evolved from group II self-splicing introns which are present, usually, in small numbers, in many bacteria, and probably, moved into the evolving eukaryotic genome from the alpha-proteobacterial progenitor of the mitochondria. Secondly, the concept of a primordial pool of 'virus-like' genetic elements implies that self-splicing introns are among the most ancient genetic entities. Thirdly, reconstructions of the ancestral state of eukaryotic genes suggest that the last common ancestor of extant eukaryotes had an intron-rich genome. Thus, it appears that ancestors of spliceosomal introns, indeed, have existed since the earliest stages of life's evolution, in a formal agreement with the introns-early scenario. However, there is no evidence that these ancient introns ever became widespread before the emergence of eukaryotes, hence, the central tenet of introns-early, the role of introns in early evolution of proteins, has no support. However, the demonstration that numerous introns invaded eukaryotic genes at the outset of eukaryotic evolution and that subsequent intron gain has been limited in many eukaryotic lineages implicates introns as an ancestral feature of eukaryotic genomes and refutes radical versions of introns-late. Perhaps, most importantly, I argue that the intron invasion triggered other pivotal events of eukaryogenesis, including the emergence of the spliceosome, the nucleus, the linear chromosomes, the telomerase, and the ubiquitin signaling system. This concept of eukaryogenesis, in a sense, revives some tenets of the exon hypothesis, by assigning to introns crucial roles in eukaryotic evolutionary innovation.<br><br>CONCLUSION: The scenario of the origin and evolution of introns that is best compatible with the results of comparative genomics and theoretical considerations goes as follows: self-splicing introns since the earliest stages of life's evolution--numerous spliceosomal introns invading genes of the emerging eukaryote during eukaryogenesis--subsequent lineage-specific loss and gain of introns. The intron invasion, probably, spawned by the mitochondrial endosymbiont, might have critically contributed to the emergence of the principal features of the eukaryotic cell. This scenario combines aspects of the introns-early and introns-late views.<br><br>REVIEWERS: this article was reviewed by W. Ford Doolittle, James Darnell (nominated by W. Ford Doolittle), William Martin, and Anthony Poole.}, }
@article {pmid16901216, year = {2006}, author = {Boore, JL}, title = {Requirements and standards for organelle genome databases.}, journal = {Omics : a journal of integrative biology}, volume = {10}, number = {2}, pages = {119-126}, doi = {10.1089/omi.2006.10.119}, pmid = {16901216}, issn = {1536-2310}, mesh = {Animals ; Chloroplasts/genetics ; Databases, Nucleic Acid/*standards ; *Genome ; *Genome, Human ; Genomics/*standards ; Humans ; Mitochondria/genetics ; Organelles/*genetics ; }, abstract = {Mitochondria and plastids (collectively called organelles) descended from prokaryotes that adopted an intracellular, endosymbiotic lifestyle within early eukaryotes. Comparisons of their remnant genomes address a wide variety of biological questions, especially when including the genomes of their prokaryotic relatives and the many genes transferred to the eukaryotic nucleus during the transitions from endosymbiont to organelle. The pace of producing complete organellar genome sequences now makes it unfeasible to do broad comparisons using the primary literature and, even if it were feasible, it is now becoming uncommon for journals to accept detailed descriptions of genome-level features. Unfortunately, no database is completely useful for this task, since they have little standardization and are riddled with error. Further, the descriptors necessary to make full use of these data are generally lacking. Here, I outline what is currently wrong and what must be done to make this data useful to the scientific community.}, }
@article {pmid16901089, year = {2005}, author = {Sato, N and Ishikawa, M and Fujiwara, M and Sonoike, K}, title = {Mass identification of chloroplast proteins of endosymbiont origin by phylogenetic profiling based on organism-optimized homologous protein groups.}, journal = {Genome informatics. International Conference on Genome Informatics}, volume = {16}, number = {2}, pages = {56-68}, pmid = {16901089}, issn = {0919-9454}, mesh = {Animals ; Arabidopsis/chemistry/genetics ; Chlamydomonas/chemistry/genetics ; Chloroplasts/*chemistry/genetics ; Multigene Family ; Mutation ; *Phylogeny ; Plant Proteins/*chemistry/genetics ; *Structural Homology, Protein ; Symbiosis/genetics/*physiology ; Synechocystis/chemistry/genetics ; }, abstract = {Chloroplasts originate from ancient cyanobacteria-like endosymbiont. Several tens of chloroplast proteins are encoded by the chloroplast genome, while more than hundreds are encoded by the nuclear genome in plants and algae, but the exact number and identity of nuclear-encoded chloroplast proteins are still unknown. We describe here attempts to identify a large number of unidentified chloroplast proteins of endosymbiont origin (CPRENDOs). Our strategy consists of whole genome protein clustering by the homolog group method, which is optimized for organism number, and phylogenetic profiling that extract groups conserved in cyanobacteria and photosynthetic eukaryotes. An initial minimal set of CPRENDOs was predicted without targeting prediction and experimentally validated.}, }
@article {pmid16892635, year = {2006}, author = {Tsai, KH and Huang, CG and Wu, WJ and Chuang, CK and Lin, CC and Chen, WJ}, title = {Parallel infection of Japanese encephalitis virus and Wolbachia within cells of mosquito salivary glands.}, journal = {Journal of medical entomology}, volume = {43}, number = {4}, pages = {752-756}, doi = {10.1603/0022-2585(2006)43[752:piojev]2.0.co;2}, pmid = {16892635}, issn = {0022-2585}, mesh = {Animals ; Culicidae/*microbiology/*virology ; Cytoplasm/microbiology ; DNA Primers/chemistry ; Encephalitis Virus, Japanese/*isolation &amp; purification ; Female ; Fluorescent Antibody Technique, Indirect/methods ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Salivary Glands/microbiology/ultrastructure/virology ; Time Factors ; Wolbachia/*isolation &amp; purification ; }, abstract = {The endosymbiont Wolbachia usually causes cytoplasmic incompatibility in dipteran hosts, including mosquitoes. However, some important arbovirus-transmitting mosquitoes such as Aedes aegypti (L.) are not heritably infected by Wolbachia. In Wolbachia-harboring mosquito Armigeres subalbatus Coquillett, colocalization of Wolbachia and inoculated Japanese encephalitis virus (family Flaviviridae, genus Flavivirus, JEV) in salivary gland (SG) cells was shown by electron microscopy. The infection rate of JEV in SGs, detected with either immunofluorescent antibody test or reverse transcription-polymerase chain reaction, did not show significant differences between Wolbachia-infected and -free colonies. It is suggested that Wolbachia did not mediate resistance of SG cells to superinfection by JEV, although both microorgamisms coexist in the same niche, i.e., the same SG cell. Therefore, a SG escape barrier may not be elevated due to Wolbachia infection, which presumably has no deleterious effects on vector competence in Wolbachia-harboring mosquitoes.}, }
@article {pmid16885306, year = {2006}, author = {Blazejak, A and Kuever, J and Erséus, C and Amann, R and Dubilier, N}, title = {Phylogeny of 16S rRNA, ribulose 1,5-bisphosphate carboxylase/oxygenase, and adenosine 5'-phosphosulfate reductase genes from gamma- and alphaproteobacterial symbionts in gutless marine worms (oligochaeta) from Bermuda and the Bahamas.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {8}, pages = {5527-5536}, pmid = {16885306}, issn = {0099-2240}, mesh = {Adenosine Phosphosulfate/metabolism ; Alphaproteobacteria/*classification/enzymology/genetics ; Animals ; Gammaproteobacteria/*classification/enzymology/genetics ; Molecular Sequence Data ; Oligochaeta/*microbiology ; Oxidoreductases/genetics ; *Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Gutless oligochaetes are small marine worms that live in obligate associations with bacterial endosymbionts. While symbionts from several host species belonging to the genus Olavius have been described, little is known of the symbionts from the host genus Inanidrilus. In this study, the diversity of bacterial endosymbionts in Inanidrilus leukodermatus from Bermuda and Inanidrilus makropetalos from the Bahamas was investigated using comparative sequence analysis of the 16S rRNA gene and fluorescence in situ hybridization. As in all other gutless oligochaetes examined to date, I. leukodermatus and I. makropetalos harbor large, oval bacteria identified as Gamma 1 symbionts. The presence of genes coding for ribulose-1,5-bisphosphate carboxylase/oxygenase form I (cbbL) and adenosine 5'-phosphosulfate reductase (aprA) supports earlier studies indicating that these symbionts are chemoautotrophic sulfur oxidizers. Alphaproteobacteria, previously identified only in the gutless oligochaete Olavius loisae from the southwest Pacific Ocean, coexist with the Gamma 1 symbionts in both I. leukodermatus and I. makropetalos, with the former harboring four and the latter two alphaproteobacterial phylotypes. The presence of these symbionts in hosts from such geographically distant oceans as the Atlantic and Pacific suggests that symbioses with alphaproteobacterial symbionts may be widespread in gutless oligochaetes. The high phylogenetic diversity of bacterial endosymbionts in two species of the genus Inanidrilus, previously known only from members of the genus Olavius, shows that the stable coexistence of multiple symbionts is a common feature in gutless oligochaetes.}, }
@article {pmid16877498, year = {2006}, author = {Nosenko, T and Lidie, KL and Van Dolah, FM and Lindquist, E and Cheng, JF and Bhattacharya, D}, title = {Chimeric plastid proteome in the Florida "red tide" dinoflagellate Karenia brevis.}, journal = {Molecular biology and evolution}, volume = {23}, number = {11}, pages = {2026-2038}, doi = {10.1093/molbev/msl074}, pmid = {16877498}, issn = {0737-4038}, mesh = {Algal Proteins/*genetics ; Animals ; Cell Line ; Chlorophyta/*genetics ; Dinoflagellida/*genetics ; Evolution, Molecular ; Expressed Sequence Tags ; Florida ; Gene Transfer, Horizontal ; Models, Genetic ; Molecular Sequence Data ; Phylogeny ; Plastids/*genetics ; *Proteome ; Rhodophyta/*genetics ; Symbiosis ; }, abstract = {Current understanding of the plastid proteome comes almost exclusively from studies of plants and red algae. The proteome in these taxa has a relatively simple origin via integration of proteins from a single cyanobacterial primary endosymbiont and the host. However, the most successful algae in marine environments are the chlorophyll c-containing chromalveolates such as diatoms and dinoflagellates that contain a plastid of red algal origin derived via secondary or tertiary endosymbiosis. Virtually nothing is known about the plastid proteome in these taxa. We analyzed expressed sequence tag data from the toxic "Florida red tide" dinoflagellate Karenia brevis that has undergone a tertiary plastid endosymbiosis. Comparative analyses identified 30 nuclear-encoded plastid-targeted proteins in this chromalveolate that originated via endosymbiotic or horizontal gene transfer (HGT) from multiple different sources. We identify a fundamental divide between plant/red algal and chromalveolate plastid proteomes that reflects a history of mixotrophy in the latter group resulting in a highly chimeric proteome. Loss of phagocytosis in the "red" and "green" clades effectively froze their proteomes, whereas chromalveolate lineages retain the ability to engulf prey allowing them to continually recruit new, potentially adaptive genes through subsequent endosymbioses and HGT. One of these genes is an electron transfer protein (plastocyanin) of green algal origin in K. brevis that likely allows this species to thrive under conditions of iron depletion.}, }
@article {pmid16860767, year = {2006}, author = {Bisht, R and Hoti, SL and Thangadurai, R and Das, PK}, title = {Isolation of Wuchereria bancrofti microfilariae from archived stained blood slides for use in genetic studies and amplification of parasite and endosymbiont genes.}, journal = {Acta tropica}, volume = {99}, number = {1}, pages = {1-5}, doi = {10.1016/j.actatropica.2005.12.009}, pmid = {16860767}, issn = {0001-706X}, mesh = {Animals ; DNA, Helminth/chemistry/genetics ; Filariasis/*blood ; Genetic Variation ; Humans ; India ; Phylogeny ; Random Amplified Polymorphic DNA Technique ; Wuchereria bancrofti/*genetics/*isolation &amp; purification ; }, abstract = {Information on change in genetic diversity of Wuchereria bancrofti is important in view of the launching of the Global Lymphatic Filariasis Elimination Programme, as it may have important consequences on the control operations and on the potential resurgence after their withdrawal. Since attention was not paid to generate such information when the programme was launched, use of archived parasite material will provide an opportunity to derive this information in a prospective manner. In this paper a simple and effective technique is reported for isolation of microfilariae of W. bancrofti from dried and stained slides archived for several years and their utility in analysis of genetic structure and amplification of certain genes of the parasite is tested. The method was found to be efficient in purifying mf from the dried smears and the DNA of the parasite found to be useful in studying the genetic structure of Wuchereria bancrofti populations using random amplified polymorphic DNA (RAPD)-PCR and for amplifying genes of the parasite and its endosymbiont, Wolbachia sp.}, }
@article {pmid16857931, year = {2006}, author = {Dolezal, P and Likic, V and Tachezy, J and Lithgow, T}, title = {Evolution of the molecular machines for protein import into mitochondria.}, journal = {Science (New York, N.Y.)}, volume = {313}, number = {5785}, pages = {314-318}, doi = {10.1126/science.1127895}, pmid = {16857931}, issn = {1095-9203}, mesh = {Bacterial Proteins/chemistry/metabolism ; Eukaryotic Cells/metabolism ; *Evolution, Molecular ; Intracellular Membranes/metabolism ; Membrane Proteins/metabolism ; Membrane Transport Proteins/chemistry/*genetics/*metabolism ; Mitochondria/*metabolism ; Mitochondrial Proteins/*metabolism ; Molecular Chaperones/metabolism ; *Protein Transport ; Serine Endopeptidases/metabolism ; Symbiosis ; }, abstract = {In creating mitochondria some 2 billion years ago, the first eukaryotes needed to establish protein import machinery in the membranes of what was a bacterial endosymbiont. Some of the preexisting protein translocation apparatus of the endosymbiont appears to have been commandeered, including molecular chaperones, the signal peptidase, and some components of the protein-targeting machinery. However, the protein translocases that drive protein import into mitochondria have no obvious counterparts in bacteria, making it likely that these machines were created de novo. The presence of similar translocase subunits in all eukaryotic genomes sequenced to date suggests that all eukaryotes can be considered descendants of a single ancestor species that carried an ancestral "protomitochondria."}, }
@article {pmid16850225, year = {2006}, author = {Montenegro, H and Petherwick, AS and Hurst, GD and Klaczko, LB}, title = {Fitness effects of Wolbachia and Spiroplasma in Drosophila melanogaster.}, journal = {Genetica}, volume = {127}, number = {1-3}, pages = {207-215}, doi = {10.1007/s10709-005-3766-4}, pmid = {16850225}, issn = {0016-6707}, mesh = {Animals ; Cell Survival ; Drosophila/*microbiology ; Extrachromosomal Inheritance ; Female ; Fertility ; Larva/growth &amp; development ; Male ; Spiroplasma/*pathogenicity ; Symbiosis/*physiology ; Wolbachia/*pathogenicity ; }, abstract = {Maternally inherited endosymbionts that manipulate the reproduction of their insect host are very common. Aside from the reproductive manipulation they produce, the fitness of these symbionts depends in part on the direct impact they have on the female host. Although this parameter has commonly been investigated for single infections, it has much more rarely been established in dual infections. We here establish the direct effect of infection with two different symbionts exhibiting different reproductive manipulation phenotypes, both alone and in combination, in the fruit fly Drosophila melanogaster. This species carries a cytoplasmic incompatibility inducing Wolbachia and a male-killing Spiroplasma, occurring as single or double (co-) infections in natural populations. We assessed direct fitness effects of these bacteria on their host, by comparing larval competitiveness and adult fecundity of uninfected, Wolbachia, Spiroplasma and Wolbachia-Spiroplasma co-infected females. We found no effect of infection status on the fitness of females for both estimates, that is, no evidence of any benefits or costs to either single or co-infection. This leads to the conclusion that both bacteria probably have other sources of benefits to persist in D. melanogaster populations, either by means of their reproductive manipulations (fitness compensation from male death in Spiroplasma infection and cytoplasmic incompatibility in Wolbachia infection) or by positive fitness interactions on other fitness components.}, }
@article {pmid16848891, year = {2006}, author = {Delmotte, F and Rispe, C and Schaber, J and Silva, FJ and Moya, A}, title = {Tempo and mode of early gene loss in endosymbiotic bacteria from insects.}, journal = {BMC evolutionary biology}, volume = {6}, number = {}, pages = {56}, pmid = {16848891}, issn = {1471-2148}, mesh = {Animals ; Gammaproteobacteria/*genetics ; *Gene Deletion ; *Genome, Bacterial ; Insecta/*microbiology ; Phylogeny ; *Selection, Genetic ; *Symbiosis ; }, abstract = {BACKGROUND: Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that measures the level of adaptive codon bias in E. coli (i.e. codon adaptive index, or CAI), and also estimates of evolutionary rates (Ka) between pairs of orthologs either in free-living bacteria or in pairs of symbionts.<br><br>RESULTS: Our results demonstrate that genes lost in the early stages of symbiosis were on average less selectively constrained than genes conserved in any of the extant symbiotic strains studied. These results also extend to more recent events of gene losses (i.e. among Buchnera strains) that still tend to concentrate on genes with low adaptive bias in E. coli and high evolutionary rates both in free-living and in symbiotic lineages. In addition, we analyzed the physical organization of gene losses for early steps of symbiosis acquisition under the hypothesis of a common origin of different symbioses. In contrast with previous findings we show that gene losses mostly occurred through loss of rather small blocks and mostly in syntenic regions between at least one of the symbionts and present-day E. coli.<br><br>CONCLUSION: At both ancient and recent stages of symbiosis evolution, gene loss was at least partially influenced by selection, highly conserved genes being retained more readily than lowly conserved genes: although losses might result from drift due to the bottlenecking of endosymbiontic populations, we demonstrated that purifying selection also acted by retaining genes of greater selective importance.}, }
@article {pmid16846383, year = {2007}, author = {Hance, T and van Baaren, J and Vernon, P and Boivin, G}, title = {Impact of extreme temperatures on parasitoids in a climate change perspective.}, journal = {Annual review of entomology}, volume = {52}, number = {}, pages = {107-126}, doi = {10.1146/annurev.ento.52.110405.091333}, pmid = {16846383}, issn = {0066-4170}, mesh = {Adaptation, Physiological ; Animals ; *Climate ; Food Chain ; Geography ; Host-Parasite Interactions/physiology ; Insecta/parasitology/*physiology ; *Temperature ; Time Factors ; }, abstract = {Parasitoids depend on a series of adaptations to the ecology and physiology of their hosts and host plants for survival and are thus likely highly susceptible to changes in environmental conditions. We analyze the effects of global warming and extreme temperatures on the life-history traits of parasitoids and interactions with their hosts. Adaptations of parasitoids to low temperatures are similar to those of most ectotherms, but these adaptations are constrained by the responses of their hosts. Life-history traits are affected by cold exposure, and extreme temperatures can reduce endosymbiont populations inside a parasitoid, eventually eliminating populations of endosymbionts that are susceptible to high temperatures. In several cases, divergences between the thermal preferences of the host and those of the parasitoid lead to a disruption of the temporal or geographical synchronization, increasing the risk of host outbreaks. A careful analysis on how host-parasitoid systems react to changes in temperature is needed so that researchers may predict and manage the consequences of global change at the ecosystem level.}, }
@article {pmid16835809, year = {2006}, author = {Pankewitz, F and Hilker, M}, title = {Defensive components in insect eggs: are anthraquinones produced during egg development?.}, journal = {Journal of chemical ecology}, volume = {32}, number = {9}, pages = {2067-2072}, pmid = {16835809}, issn = {0098-0331}, mesh = {Animals ; Anthracenes/metabolism ; Anthralin/metabolism ; Anthraquinones/*metabolism ; Coleoptera/parasitology/*physiology ; Female ; Gas Chromatography-Mass Spectrometry ; Larva/drug effects/*growth &amp; development ; Oviposition/*physiology ; Ovum/drug effects/parasitology/*physiology ; }, abstract = {Eggs of several insect species are protected against natural enemies by noxious components. However, almost nothing is known about the fate of these defensive substances during egg development nor their site of biosynthesis. The eggs of several leaf beetle species of the taxon Galerucini contain components that are unusual in insects: 1,8-dihydroxylated anthraquinones and anthrones that deter predators such as ants and birds. These components, i.e., the anthrones dithranol and chrysarobin, and the anthraquinones chrysazin and chrysophanol, are not sequestered from host plants. We asked whether the amounts of these components in the overwintering eggs of Galeruca tanaceti change from deposition to larval hatching. Gas chromatography-mass spectroscopy (GC-MS) analyses of eggs revealed a significant decrease in total amounts of dithranol and chrysophanol from egg deposition in autumn to the next spring 5 months later. Thus, these results do not provide any hint of active anthraquinone biosynthesis within eggs. Instead, the anthrones and anthraquinones that must be incorporated by the female into the eggs seem to be degraded to some extent either by the embryo or endosymbionts. GC-MS analyses showed that parasitization of eggs had some effects on the quantities of anthrones and anthraquinones.}, }
@article {pmid16825653, year = {2006}, author = {Noel, GR and Atibalentja, N}, title = {'Candidatus Paenicardinium endonii', an endosymbiont of the plant-parasitic nematode Heterodera glycines (Nemata: Tylenchida), affiliated to the phylum Bacteroidetes.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {56}, number = {Pt 7}, pages = {1697-1702}, doi = {10.1099/ijs.0.64234-0}, pmid = {16825653}, issn = {1466-5026}, mesh = {Actin Cytoskeleton/ultrastructure ; Animal Structures/microbiology ; Animals ; Bacterial Proteins/genetics ; Bacteroidetes/*classification/cytology/genetics/*isolation &amp; purification ; DNA Gyrase/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genes, rRNA ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Symbiosis ; Tylenchoidea/*microbiology ; }, abstract = {Bacteria-like endosymbionts of females of the plant-parasitic nematodes Globodera rostochiensis and Heterodera goettingiana and juveniles of Heterodera glycines were first observed during transmission electron microscopy (TEM) studies conducted in the 1970s. These organisms were characterized as being rod-shaped, ranging in size from 0.3 to 0.5 microm in diameter and 1.8 to 3 microm in length and containing structures labelled as striated inclusion bodies or tubular structures. A population of H. glycines was obtained from the soybean field where infected nematodes were first discovered in order to conduct TEM studies of females and males and to determine the phylogenetic position of the H. glycines endosymbiont among bacteria by studying the 16S rRNA and gyrB gene sequences. The bacterium was observed in the pseudocoelom and intestine of juveniles, females and males, in hypodermal chords of juveniles and males, in ovary walls and in oocytes and spermatozoa. The bacterium was polymorphic, measuring 0.4-0.8 x 2.5-4.5 microm, and many specimens contained an array of microfilament-like structures similar to those observed in "Candidatus Cardinium hertigii", the endosymbiont of Encarsia spp. wasps. Phylogenetic analysis of the 16S rRNA and gyrB genes of the H. glycines-infecting bacterium revealed 93 % and 81 % sequence identity, respectively, to the homologous genes in "Candidatus C. hertigii". Thus, the name "Candidatus Paenicardinium endonii" is proposed for the bacterial endosymbiont of the plant-parasitic nematode H. glycines.}, }
@article {pmid16824010, year = {2006}, author = {Lynch, M}, title = {Streamlining and simplification of microbial genome architecture.}, journal = {Annual review of microbiology}, volume = {60}, number = {}, pages = {327-349}, doi = {10.1146/annurev.micro.60.080805.142300}, pmid = {16824010}, issn = {0066-4227}, mesh = {Animals ; Arthropods/genetics ; Evolution, Molecular ; Genes, Mitochondrial ; Genetic Drift ; *Genetics, Microbial ; *Genome ; Genome, Bacterial ; Genome, Viral ; Mutation ; Operon ; Phenotype ; Symbiosis ; }, abstract = {The genomes of unicellular species, particularly prokaryotes, are greatly reduced in size and simplified in terms of gene structure relative to those of multicellular eukaryotes. Arguments proposed to explain this disparity include selection for metabolic efficiency and elevated rates of deletion in microbes, but the evidence in support of these hypotheses is at best equivocal. An alternative explanation based on fundamental population-genetic principles is proposed here. By increasing the mutational target sizes of associated genes, most forms of nonfunctional DNA are opposed by weak selection. Free-living microbial species have elevated effective population sizes, and the consequent reduction in the power of random genetic drift appears to be sufficient to enable natural selection to inhibit the accumulation of excess DNA. This hypothesis provides a potentially unifying explanation for the continuity in genomic scaling from prokaryotes to multicellular eukaryotes, the divergent patterns of mitochondrial evolution in animals and land plants, and various aspects of genomic modification in microbial endosymbionts.}, }
@article {pmid16822756, year = {2006}, author = {Cavalier-Smith, T}, title = {Origin of mitochondria by intracellular enslavement of a photosynthetic purple bacterium.}, journal = {Proceedings. Biological sciences}, volume = {273}, number = {1596}, pages = {1943-1952}, pmid = {16822756}, issn = {0962-8452}, mesh = {Bacterial Proteins/classification/metabolism/physiology ; *Biological Evolution ; Eukaryotic Cells/ultrastructure ; Gene Transfer, Horizontal ; Genome ; Membrane Proteins/classification/metabolism/physiology ; Mitochondria/genetics/*metabolism/ultrastructure ; Mitochondrial Membrane Transport Proteins/classification/genetics/metabolism ; Mitochondrial Membranes/metabolism/ultrastructure ; Mitochondrial Proteins/classification/metabolism/physiology ; Models, Biological ; Phagocytosis ; Photosynthesis ; Proteobacteria/genetics/*metabolism/ultrastructure ; Symbiosis ; }, abstract = {Mitochondria originated by permanent enslavement of purple non-sulphur bacteria. These endosymbionts became organelles through the origin of complex protein-import machinery and insertion into their inner membranes of protein carriers for extracting energy for the host. A chicken-and-egg problem exists: selective advantages for evolving import machinery were absent until inner membrane carriers were present, but this very machinery is now required for carrier insertion. I argue here that this problem was probably circumvented by conversion of the symbiont protein-export machinery into protein-import machinery, in three phases. I suggest that the first carrier entered the periplasmic space via pre-existing beta-barrel proteins in the bacterial outer membrane that later became Tom40, and inserted into the inner membrane probably helped by a pre-existing inner membrane protein, thereby immediately providing the protoeukaryote host with photosynthesate. This would have created a powerful selective advantage for evolving more efficient carrier import by inserting Tom70 receptors. Massive gene transfer to the nucleus inevitably occurred by mutation pressure. Finally, pressure from harmful, non-selected gene transfer to the nucleus probably caused evolution of the presequence mechanism, and photosynthesis was lost.}, }
@article {pmid16820474, year = {2006}, author = {Goto, S and Anbutsu, H and Fukatsu, T}, title = {Asymmetrical interactions between Wolbachia and Spiroplasma endosymbionts coexisting in the same insect host.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {7}, pages = {4805-4810}, pmid = {16820474}, issn = {0099-2240}, mesh = {Animals ; DNA/analysis/isolation &amp; purification ; DNA, Bacterial/analysis/isolation &amp; purification ; Drosophila melanogaster/growth &amp; development/*microbiology ; Female ; Polymerase Chain Reaction ; Spiroplasma/genetics/*growth &amp; development ; *Symbiosis ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {We investigated the interactions between the endosymbionts Wolbachia pipientis strain wMel and Spiroplasma sp. strain NSRO coinfecting the host insect Drosophila melanogaster. By making use of antibiotic therapy, temperature stress, and hemolymph microinjection, we established the following strains in the same host genetic background: the SW strain, infected with both Spiroplasma and Wolbachia; the S strain, infected with Spiroplasma only; and the W strain, infected with Wolbachia only. The infection dynamics of the symbionts in these strains were monitored by quantitative PCR during host development. The infection densities of Spiroplasma exhibited no significant differences between the SW and S strains throughout the developmental course. In contrast, the infection densities of Wolbachia were significantly lower in the SW strain than in the W strain at the pupal and young adult stages. These results indicated that the interactions between the coinfecting symbionts were asymmetrical, i.e., Spiroplasma organisms negatively affected the population of Wolbachia organisms, while Wolbachia organisms did not influence the population of Spiroplasma organisms. In the host body, the symbionts exhibited their own tissue tropisms: among the tissues examined, Spiroplasma was the most abundant in the ovaries, while Wolbachia showed the highest density in Malpighian tubules. Strikingly, basically no Wolbachia organisms were detected in hemolymph, the principal location of Spiroplasma. These results suggest that different host tissues act as distinct microhabitats for the symbionts and that the lytic process in host metamorphosis might be involved in the asymmetrical interactions between the coinfecting symbionts.}, }
@article {pmid16818783, year = {2006}, author = {Turner, JD and Langley, RS and Johnston, KL and Egerton, G and Wanji, S and Taylor, MJ}, title = {Wolbachia endosymbiotic bacteria of Brugia malayi mediate macrophage tolerance to TLR- and CD40-specific stimuli in a MyD88/TLR2-dependent manner.}, journal = {Journal of immunology (Baltimore, Md. : 1950)}, volume = {177}, number = {2}, pages = {1240-1249}, doi = {10.4049/jimmunol.177.2.1240}, pmid = {16818783}, issn = {0022-1767}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Adaptor Proteins, Signal Transducing/*physiology ; Animals ; Brugia malayi/*immunology/microbiology ; CD40 Antigens/biosynthesis/*physiology ; Cells, Cultured ; Dose-Response Relationship, Immunologic ; Down-Regulation/immunology ; Female ; *Immune Tolerance ; Lipopolysaccharide Receptors/biosynthesis ; Lipopolysaccharides/administration &amp; dosage/pharmacology ; Macrophage Activation/immunology ; Macrophages, Peritoneal/*immunology/metabolism/microbiology ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C3H ; Mice, Inbred C57BL ; Mice, Knockout ; Myeloid Differentiation Factor 88 ; Symbiosis/*immunology ; Toll-Like Receptor 2/biosynthesis/deficiency/genetics/*physiology ; Toll-Like Receptor 4/antagonists &amp; inhibitors/biosynthesis ; Transforming Growth Factor beta/biosynthesis ; Transforming Growth Factor beta1 ; Up-Regulation/immunology ; Wolbachia/*immunology ; }, abstract = {Lymphatic filarial nematodes are able to down-regulate parasite-specific and nonspecific responses of lymphocytes and APC. Lymphatic filariae are reliant on Wolbachia endosymbiotic bacteria for development and survival. We tested the hypothesis that repeated exposure to Wolbachia endosymbionts would drive macrophage tolerance in vitro and in vivo. We pre-exposed murine peritoneal-elicited macrophages to soluble extracts of Brugia malayi female worms (BMFE) before restimulating with BMFE or TLR agonists. BMFE tolerized macrophages (in terms of IFN-beta, IL-1beta, IL-6, IL-12p40, and TNF-alpha inflammatory cytokine production) in a dose-dependent manner toward self, LPS, MyD88-dependent TLR2 or TLR9 ligands (peptidoglycan, triacyl lipopeptide, CpG DNA) and the MyD88-independent/TRIF-dependent TLR3 ligand, polyinosinic-polycytidylic acid. This was accompanied with down-regulation in surface expression of TLR4 and up-regulation of CD14, CD40, and TLR2. BMFE tolerance extended to CD40 activation in vitro and systemic inflammation following lethal challenge in an in vivo model of endotoxin shock. The mechanism of BMFE-mediated macrophage tolerance was dependent on MyD88 and TLR2 but not TLR4. Evidence that desensitization was driven by Wolbachia-specific ligands was determined by use of extracts from Wolbachia-depleted B. malayi, aposymbiotic filarial species, and a cell line stably infected with Wolbachia pipientis. Our data promote a role for Wolbachia in contributing toward the dysregulated and tolerized immunological phenotype that accompanies the majority of human filarial infections.}, }
@article {pmid16800120, year = {2006}, author = {Guerrero, R and Bain, O and Attout, T and Martin, C}, title = {The infective larva of Litomosoides yutajensis Guerrero et al., 2003 (Nematoda: Onchocercidae), a Wolbachia-free filaria from bat.}, journal = {Parasite (Paris, France)}, volume = {13}, number = {2}, pages = {127-130}, doi = {10.1051/parasite/2006132127}, pmid = {16800120}, issn = {1252-607X}, mesh = {Animals ; Arachnid Vectors/parasitology ; Chiroptera/*parasitology ; Female ; Filariasis/parasitology/transmission/*veterinary ; Filarioidea/anatomy &amp; histology/*classification/growth &amp; development ; Host-Parasite Interactions ; Larva ; *Life Cycle Stages ; Male ; Mites/parasitology ; Phylogeny ; Species Specificity ; Venezuela ; }, abstract = {The infective larva of Litomosoides yutajensis Guerrero et al., 2003, a parasite of the bat Pteronotus pamellii, is described; it is distinct from congeneric infective larvae by the absence of caudal lappets. The life cycles of five other species of Litomosoides are known; three are parasites of rodents, one of a marsupial and one of a bat. As with these species, the experimental vector of L. yutoajensis used was the macronyssid mite Ornithonyssus bacoti. In nature, the main vectors are probably other macronyssids but transmission by O. bacoti, with its large host-range, could account for the characteristic host-switchings in the evolution of Litomosoides. Unlike the murine model L. sigmodontis Chandler, 1931, L. yutajensis is devoid of the endosymbiontic bacteria Wolbachia and may be of great interest.}, }
@article {pmid16788898, year = {2006}, author = {Rosenberg, NK and Lee, RW and Yancey, PH}, title = {High contents of hypotaurine and thiotaurine in hydrothermal-vent gastropods without thiotrophic endosymbionts.}, journal = {Journal of experimental zoology. Part A, Comparative experimental biology}, volume = {305}, number = {8}, pages = {655-662}, doi = {10.1002/jez.a.316}, pmid = {16788898}, issn = {1548-8969}, mesh = {Adaptation, Physiological/physiology ; Animals ; Betaine/analysis/metabolism ; Gastropoda/chemistry/*metabolism/*microbiology ; Glycerylphosphorylcholine/analysis/metabolism ; *Hot Temperature ; Hydrogen Sulfide/metabolism ; Oceans and Seas ; Sulfur-Reducing Bacteria/*metabolism ; Symbiosis/*physiology ; Taurine/*analogs &amp; derivatives/analysis/metabolism ; }, abstract = {Invertebrates at hydrothermal vents and cold seeps must cope with high levels of toxic H2S. In addition, these and all marine invertebrates must balance internal osmotic pressure with that of the ocean. Cells usually do so with organic osmolytes, primarily free amino acids (e.g., taurine, glycine) and methylamines (e.g., betaine). At vents and seeps, clams, mussels, and vestimentiferans with thiotrophic endosymbionts have high levels of hypotaurine and thiotaurine (a product of hypotaurine and HS-). These serve as osmolytes but their primary function may be to transport and/or detoxify sulfide; indeed, thiotaurine has been proposed to be a marker of thiotrophic symbiosis. To test this, we analyzed Depressigyra globulus snails and Lepetodrilus fucensis limpets from Juan de Fuca Ridge vents (1,530 m). Neither has endosymbionts, though the latter has thiotrophic ectosymbionts. Some specimens were rapidly frozen, while other live ones were kept in laboratory chambers, some with and others without sulfide. Non-vent gastropods from a variety of depths (2-3,000 m) were also collected. Tissues were analyzed for major osmolytes and taurine derivatives. The dominant osmolytes of non-vent snails were betaine in all species, and either taurine in shallow-living species or scyllo-inositol, glycerophosphorylcholine, and other amino acids in deep-sea species. In contrast, the dominant osmolytes were hypotaurine and betaine in D. globulus, and hypotaurine in L. fucensis. Both species had thiotaurine (as well as hypotaurine) at levels much greater than previously reported for vent and seep animals without endosymbionts. The ratio of thio- to thio- plus hypotaurine, a possible indicator of sulfide exposure, decreased in both species when kept in laboratory chambers with low or no sulfide, but stayed at high levels in snails kept with 3-5 mM sulfide. Thus, in some vent animals without endosymbionts, sulfide may be detoxified via conversion of hypotaurine to thiotaurine. The latter may be a marker of high sulfide exposure but not of thiotrophic endosymbionts.}, }
@article {pmid16783009, year = {2006}, author = {Mateos, M and Castrezana, SJ and Nankivell, BJ and Estes, AM and Markow, TA and Moran, NA}, title = {Heritable endosymbionts of Drosophila.}, journal = {Genetics}, volume = {174}, number = {1}, pages = {363-376}, pmid = {16783009}, issn = {0016-6731}, mesh = {Animals ; Bacterial Infections/*transmission ; DNA, Bacterial/analysis ; Drosophila/*genetics/*microbiology ; Female ; Gene Frequency ; Genetic Variation ; *Infectious Disease Transmission, Vertical ; Male ; Molecular Sequence Data ; Phylogeny ; Spiroplasma/genetics/physiology ; Symbiosis/*genetics ; Wolbachia/genetics/physiology ; }, abstract = {Although heritable microorganisms are increasingly recognized as widespread in insects, no systematic screens for such symbionts have been conducted in Drosophila species (the primary insect genetic models for studies of evolution, development, and innate immunity). Previous efforts screened relatively few Drosophila lineages, mainly for Wolbachia. We conducted an extensive survey of potentially heritable endosymbionts from any bacterial lineage via PCR screens of mature ovaries in 181 recently collected fly strains representing 35 species from 11 species groups. Due to our fly sampling methods, however, we are likely to have missed fly strains infected with sex ratio-distorting endosymbionts. Only Wolbachia and Spiroplasma, both widespread in insects, were confirmed as symbionts. These findings indicate that in contrast to some other insect groups, other heritable symbionts are uncommon in Drosophila species, possibly reflecting a robust innate immune response that eliminates many bacteria. A more extensive survey targeted these two symbiont types through diagnostic PCR in 1225 strains representing 225 species from 32 species groups. Of these, 19 species were infected by Wolbachia while only 3 species had Spiroplasma. Several new strains of Wolbachia and Spiroplasma were discovered, including ones divergent from any reported to date. The phylogenetic distribution of Wolbachia and Spiroplasma in Drosophila is discussed.}, }
@article {pmid16780600, year = {2006}, author = {Chen, B and Zhong, D and Monteiro, A}, title = {Comparative genomics and evolution of the HSP90 family of genes across all kingdoms of organisms.}, journal = {BMC genomics}, volume = {7}, number = {}, pages = {156}, pmid = {16780600}, issn = {1471-2164}, mesh = {Alternative Splicing ; Amino Acid Sequence ; Animals ; Archaeal Proteins/chemistry/genetics ; Bacterial Proteins/chemistry/genetics ; Chromosome Mapping ; Complementarity Determining Regions ; Conserved Sequence ; *Evolution, Molecular ; Genetic Variation ; Genomics ; HSP90 Heat-Shock Proteins/chemistry/*genetics/physiology ; Molecular Sequence Data ; Multigene Family ; Sequence Alignment ; Sequence Homology, Amino Acid ; Terminology as Topic ; Vertebrates ; }, abstract = {BACKGROUND: HSP90 proteins are essential molecular chaperones involved in signal transduction, cell cycle control, stress management, and folding, degradation, and transport of proteins. HSP90 proteins have been found in a variety of organisms suggesting that they are ancient and conserved. In this study we investigate the nuclear genomes of 32 species across all kingdoms of organisms, and all sequences available in GenBank, and address the diversity, evolution, gene structure, conservation and nomenclature of the HSP90 family of genes across all organisms.<br><br>RESULTS: Twelve new genes and a new type HSP90C2 were identified. The chromosomal location, exon splicing, and prediction of whether they are functional copies were documented, as well as the amino acid length and molecular mass of their polypeptides. The conserved regions across all protein sequences, and signature sequences in each subfamily were determined, and a standardized nomenclature system for this gene family is presented. The proeukaryote HSP90 homologue, HTPG, exists in most Bacteria species but not in Archaea, and it evolved into three lineages (Groups A, B and C) via two gene duplication events. None of the organellar-localized HSP90s were derived from endosymbionts of early eukaryotes. Mitochondrial TRAP and endoplasmic reticulum HSP90B separately originated from the ancestors of HTPG Group A in Firmicutes-like organisms very early in the formation of the eukaryotic cell. TRAP is monophyletic and present in all Animalia and some Protista species, while HSP90B is paraphyletic and present in all eukaryotes with the exception of some Fungi species, which appear to have lost it. Both HSP90C (chloroplast HSP90C1 and location-undetermined SP90C2) and cytosolic HSP90A are monophyletic, and originated from HSP90B by independent gene duplications. HSP90C exists only in Plantae, and was duplicated into HSP90C1 and HSP90C2 isoforms in higher plants. HSP90A occurs across all eukaryotes, and duplicated into HSP90AA and HSP90AB in vertebrates. Diplomonadida was identified as the most basal organism in the eukaryote lineage.<br><br>CONCLUSION: The present study presents the first comparative genomic study and evolutionary analysis of the HSP90 family of genes across all kingdoms of organisms. HSP90 family members underwent multiple duplications and also subsequent losses during their evolution. This study established an overall framework of information for the family of genes, which may facilitate and stimulate the study of this gene family across all organisms.}, }
@article {pmid16777718, year = {2006}, author = {Xi, Z and Khoo, CC and Dobson, SL}, title = {Interspecific transfer of Wolbachia into the mosquito disease vector Aedes albopictus.}, journal = {Proceedings. Biological sciences}, volume = {273}, number = {1592}, pages = {1317-1322}, pmid = {16777718}, issn = {0962-8452}, support = {R01 AI051533/AI/NIAID NIH HHS/United States ; AI 51533/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*microbiology/physiology ; Animals ; Drosophila/microbiology ; Female ; Fertility ; Insect Vectors/*microbiology ; Male ; Microinjections ; Oocytes/cytology/microbiology ; Population Control/methods ; Rickettsiaceae Infections/*prevention &amp; control/transmission ; Wolbachia/genetics/*physiology ; }, abstract = {Intracellular Wolbachia bacteria are obligate, maternally inherited endosymbionts found frequently in insects and other invertebrates. The evolutionary success of Wolbachia is due in part to an ability to manipulate reproduction. In mosquitoes and many other insects, Wolbachia causes a form of sterility known as cytoplasmic incompatibility (CI). Wolbachia-induced CI has attracted interest as a potential agent for affecting medically important disease vectors. However, application of the approach has been restricted by an absence of appropriate, naturally occurring Wolbachia infections. Here, we report the interspecific transfer of Wolbachia infection into a medically important mosquito. Using embryonic microinjection, Wolbachia is transferred from Drosophila simulans into the invasive pest and disease vector: Aedes albopictus (Asian tiger mosquito). The resulting infection is stably maintained and displays a unique pattern of bidirectional CI in crosses with naturally infected mosquitoes. Laboratory population cage experiments examine a strategy in which releases of Wolbachia-infected males are used to suppress mosquito egg hatch. We discuss the results in relation to developing appropriate Wolbachia-infected mosquito strains for population replacement and population suppression strategies.}, }
@article {pmid16769630, year = {2006}, author = {Rasgon, JL and Cornel, AJ and Scott, TW}, title = {Evolutionary history of a mosquito endosymbiont revealed through mitochondrial hitchhiking.}, journal = {Proceedings. Biological sciences}, volume = {273}, number = {1594}, pages = {1603-1611}, pmid = {16769630}, issn = {0962-8452}, support = {F31 GM020092/GM/NIGMS NIH HHS/United States ; GM020092/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Culex/*genetics/microbiology ; DNA, Mitochondrial/*chemistry ; *Evolution, Molecular ; *Genes, Mitochondrial ; Genetic Variation ; Haplotypes ; Phylogeny ; Symbiosis ; Wolbachia/*physiology ; }, abstract = {Due to cytoplasmic inheritance, spread of maternally inherited Wolbachia symbionts can result in reduction of mitochondrial variation in populations. We examined sequence diversity of the mitochondrial NADH dehydrogenase subunit 4 (ND4) gene in Wolbachia-infected (South Africa (SA), California and Thailand) and uninfected (SA) Culex pipiens complex populations. In total, we identified 12 haplotypes (A-L). In infected populations, 99% of individuals had haplotype K. In the uninfected SA population, 11 haplotypes were present, including K. Nuclear allozyme diversity was similar between infected and uninfected SA populations. Analysis of nuclear DNA sequences suggested that haplotype K presence in uninfected SA Cx. pipiens was probably due to a shared ancestral polymorphism rather than hybrid introgression. These data indicate that Wolbachia spread has resulted in drastic reduction of mitochondrial variability in widely separated Cx. pipiens complex populations. In contrast, the uninfected SA population is probably a cryptic species where Wolbachia introgression has been prevented by reproductive isolation, maintaining ancestral levels of mitochondrial diversity. Molecular clock analyses suggest that the Wolbachia sweep occurred within the last 47000 years. The effect of Wolbachia on mitochondrial dynamics can provide insight on the potential for Wolbachia to spread transgenes into mosquito populations to control vector-borne diseases.}, }
@article {pmid16769511, year = {2006}, author = {Zhang, N and Scott, V and Al-Samarrai, TH and Tan, YY and Spiering, MJ and McMillan, LK and Lane, GA and Scott, DB and Christensen, MJ and Schmid, J}, title = {Transformation of the ryegrass endophyte Neotyphodium lolii can alter its in planta mycelial morphology.}, journal = {Mycological research}, volume = {110}, number = {Pt 5}, pages = {601-611}, doi = {10.1016/j.mycres.2006.01.011}, pmid = {16769511}, issn = {0953-7562}, mesh = {Alkaloids/analysis ; Hydroxymethylglutaryl CoA Reductases/genetics ; Hypocreales/cytology/*genetics/growth &amp; development ; Lolium/chemistry/*microbiology ; Mycelium/*cytology ; Promoter Regions, Genetic ; Symbiosis ; Transformation, Genetic ; }, abstract = {The fungus Neotyphodium lolii grows in the intercellular spaces of perennial ryegrass as a mutualistic endosymbiont. One of the benefits it conveys to the plant is the production of alkaloids toxic to herbivores. We wanted to determine in planta expression patterns of the N. lolii 3-hydroxy-3-methylglutaryl-CoA reductase (HMG CoA reductase) gene, believed to be involved in the synthesis of two of these alkaloid toxins, lolitrem B and ergovaline. We transformed the N. lolii strain Lp19 with plasmids, in which DNA fragments upstream of the open reading frame of the N. lolii HMG CoA reductase gene controlled expression of the GUS (gusA; Escherichia coli beta-glucuronidase) reporter gene. In exponentially growing cultures, the GUS gene was not expressed if the length of upstream sequence was less than 400 bp, and >1100 bp were required for maximum expression. When reintroduced into ryegrass plants, transformants often showed highly increased hyphal branching compared to the wild-type parent strain, although in culture their growth kinetics and morphology were indistinguishable from that of the wild-type. Deterioration of hyphae and the hypha-plant interface occurred and in one transformant reduced tillering (formation of new plants, referred to in agronomy as tillers) and death of infected plants. We found no evidence that these abnormalities were caused by interference of the construct with the function of the native gene, as judged by analysis of the site of integration of the promoter-GUS cassette, expression of the native gene and lolitrem B and ergovaline levels in infected plants. However, there was some correlation between GUS expression and the degree of hyphal branching, suggesting that high levels of beta-glucuronidase may disturb the symbiotic interaction. Levels of another alkaloid, peramine, were also not significantly affected by transformation. In previous studies increased in planta branching of the endophyte has been shown to be associated with a severe reduction of alkaloid production. Our results show that a plant-endophyte association in which increased branching occurs is still able to produce alkaloids.}, }
@article {pmid16761196, year = {2006}, author = {Elsaied, HE and Kaneko, R and Naganuma, T}, title = {Molecular characterization of a deep-sea methanotrophic mussel symbiont that carries a RuBisCO gene.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {8}, number = {5}, pages = {511-520}, pmid = {16761196}, issn = {1436-2228}, mesh = {Animals ; Bivalvia/*microbiology ; Methylococcaceae/*enzymology/*genetics ; Oceans and Seas ; Phylogeny ; Ribulose-Bisphosphate Carboxylase/*genetics/metabolism ; Symbiosis/*physiology ; }, abstract = {In our previous investigation on the genes of 1,5-ribulose bisphosphate carboxylase/oxygenase (RuBisCO; EC 4.1.1.39) in deep-sea chemoautotrophic and methanotrophic endosymbioses, the gene encoding the large subunit of RuBisCO form I (cbbL) had been detected in the gill of a mussel belonging to the genus Bathymodiolus from a western Pacific back-arc hydrothermal vent. This study further examined the symbiont source of the RuBisCO cbbL gene along with the genes of 16S ribosomal RNA (16S rDNA) and particulate methane monooxygenase (EC 1.14.13.25; pmoA) and probed for the presence of the ATP sulfurylase gene (EC 2.7.7.4; sopT). The 16S rDNA sequence analysis indicated that the mussel harbors a monospecific methanotrophic Gammaproteobacterium. This was confirmed by amplification and sequencing of the methanotrophic pmoA, while thiotrophic sopT was not amplified from the same symbiotic genome DNA. Fluorescence in situ hybridization demonstrated simultaneous occurrence of the symbiont-specific 16S rDNA, cbbL and pmoA, but not sopT, in the mussel gill. This is the first molecular and visual evidence for a methanotrophic bacterial endosymbiont that bears the RuBisCO cbbL gene relevant to autotrophic CO(2) fixation.}, }
@article {pmid16760254, year = {2006}, author = {Gilson, PR and Su, V and Slamovits, CH and Reith, ME and Keeling, PJ and McFadden, GI}, title = {Complete nucleotide sequence of the chlorarachniophyte nucleomorph: nature's smallest nucleus.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {103}, number = {25}, pages = {9566-9571}, pmid = {16760254}, issn = {0027-8424}, mesh = {Base Sequence ; Biological Evolution ; Cell Nucleus/*genetics ; Cell Size ; Chromosome Mapping ; Chromosomes/genetics ; Eukaryota/*cytology/*genetics ; Genome/genetics ; Introns/genetics ; Molecular Sequence Data ; Plastids/metabolism ; RNA Splicing ; }, abstract = {The introduction of plastids into different heterotrophic protists created lineages of algae that diversified explosively, proliferated in marine and freshwater environments, and radically altered the biosphere. The origins of these secondary plastids are usually inferred from the presence of additional plastid membranes. However, two examples provide unique snapshots of secondary-endosymbiosis-in-action, because they retain a vestige of the endosymbiont nucleus known as the nucleomorph. These are chlorarachniophytes and cryptomonads, which acquired their plastids from a green and red alga respectively. To allow comparisons between them, we have sequenced the nucleomorph genome from the chlorarachniophyte Bigelowiella natans: at a mere 373,000 bp and with only 331 genes, the smallest nuclear genome known and a model for extreme reduction. The genome is eukaryotic in nature, with three linear chromosomes containing densely packed genes with numerous overlaps. The genome is replete with 852 introns, but these are the smallest introns known, being only 18, 19, 20, or 21 nt in length. These pygmy introns are shown to be miniaturized versions of normal-sized introns present in the endosymbiont at the time of capture. Seventeen nucleomorph genes encode proteins that function in the plastid. The other nucleomorph genes are housekeeping entities, presumably underpinning maintenance and expression of these plastid proteins. Chlorarachniophyte plastids are thus serviced by three different genomes (plastid, nucleomorph, and host nucleus) requiring remarkable coordination and targeting. Although originating by two independent endosymbioses, chlorarachniophyte and cryptomonad nucleomorph genomes have converged upon remarkably similar architectures but differ in many molecular details that reflect two distinct trajectories to hypercompaction and reduction.}, }
@article {pmid16754614, year = {2006}, author = {Embley, TM}, title = {Multiple secondary origins of the anaerobic lifestyle in eukaryotes.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {361}, number = {1470}, pages = {1055-1067}, pmid = {16754614}, issn = {0962-8436}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Anaerobiosis/*physiology ; *Biological Evolution ; Eukaryotic Cells/enzymology/*physiology ; Hydrogenase/genetics ; Iron-Sulfur Proteins/genetics ; Mitochondria/genetics/metabolism ; Phylogeny ; Pyruvate Synthase/genetics ; }, abstract = {Classical ideas for early eukaryotic evolution often posited a period of anaerobic evolution producing a nucleated phagocytic cell to engulf the mitochondrial endosymbiont, whose presence allowed the host to colonize emerging aerobic environments. This idea was given credence by the existence of contemporary anaerobic eukaryotes that were thought to primitively lack mitochondria, thus providing examples of the type of host cell needed. However, the groups key to this hypothesis have now been shown to contain previously overlooked mitochondrial homologues called hydrogenosomes or mitosomes; organelles that share common ancestry with mitochondria but which do not carry out aerobic respiration. Mapping these data on the unfolding eukaryotic tree reveals that secondary adaptation to anaerobic habitats is a reoccurring theme among eukaryotes. The apparent ubiquity of mitochondrial homologues bears testament to the importance of the mitochondrial endosymbiosis, perhaps as a founding event, in eukaryotic evolution. Comparative study of different mitochondrial homologues is needed to determine their fundamental importance for contemporary eukaryotic cells.}, }
@article {pmid16752208, year = {2006}, author = {Gould, SB and Sommer, MS and Hadfi, K and Zauner, S and Kroth, PG and Maier, UG}, title = {Protein targeting into the complex plastid of cryptophytes.}, journal = {Journal of molecular evolution}, volume = {62}, number = {6}, pages = {674-681}, pmid = {16752208}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Biological Transport ; Computational Biology ; Cryptophyta/*physiology ; Membrane Proteins/*metabolism ; Molecular Sequence Data ; Plastids/*physiology ; Protein Sorting Signals/*genetics ; Protein Transport/physiology ; Proteins/*metabolism ; Symbiosis/physiology ; Transferases/genetics ; }, abstract = {The cryptophyte Guillardia theta harbors a plastid surrounded by four membranes. This turns protein targeting of nucleus-encoded endosymbiont localized proteins into quite a challenge, as the respective precursors have to pass either all four membranes to reach the plastid stroma or only the outermost two membranes to enter the periplastidal compartment. Therefore two sets of nuclear-encoded proteins imported into the endosymbiont can be distinguished and their topogenic signals may serve as good indicators for studying protein targeting and subsequent transport across the outermost membranes of the cryptophyte plastid. We isolated genes encoding enzymes involved in two different biochemical pathways, both of which are predicted to be localized inside the periplastidal compartment, and compared their topogenic signals to those of precursor proteins for the plastid stroma, which are encoded on either the nucleus or the nucleomorph. By this and exemplary in vitro and in vivo analyses of the topogenic signal of one protein localized in the periplastidal compartment, we present new data implicating the mechanism of targeting and transport of proteins to and across the outermost plastid membranes. Furthermore, we demonstrate that one single, but conserved amino acid is the triggering key for the discrimination between nucleus-encoded plastid and periplastidal proteins.}, }
@article {pmid16739448, year = {2006}, author = {Wade, MJ and Goodnight, CJ}, title = {Cyto-nuclear epistasis: two-locus random genetic drift in hermaphroditic and dioecious species.}, journal = {Evolution; international journal of organic evolution}, volume = {60}, number = {4}, pages = {643-659}, pmid = {16739448}, issn = {0014-3820}, support = {1R01GM 065414-01A1/GM/NIGMS NIH HHS/United States ; }, mesh = {Alleles ; Animals ; Cell Nucleus/metabolism ; Cytoplasm/metabolism ; *Epistasis, Genetic ; Evolution, Molecular ; Female ; Genetic Drift ; Genetic Variation ; Genome ; Male ; Models, Genetic ; Wolbachia ; }, abstract = {We report the findings of our theoretical investigation of the effect of random genetic drift on the covariance of identity-by-descent (ibd) of nuclear and cytoplasmic genes. The covariance in ibd measures of the degree to which cyto-nuclear gene combinations are heritable, that is, transmitted together from parents to offspring. We show how the mating system affects the covariance of ibd, a potentially important aspect of host-pathogen or host-symbiont coevolution. The magnitude of this covariance influences the degree to which the evolution of apparently neutral cytoplasmic genes, often used in molecular phylogenetics, might be influenced by selection acting on unlinked nuclear genes. To the extent that cyto-nuclear gene combinations are inherited together, genomic conflict is mitigated and intergenomic transfer it facilitated, because genes in both organelle and nuclear genomes share the same evolutionary fate. The covariance of ibd also affects the rate at which cyto-nuclear epistatic variance is converted to additive variance necessary for a response to selection. We find that conversion is biased in species with separate sexes, so that the increment of additive variance added to the nuclear genome exceeds that added to the cytoplasmic genome. As a result, the host might have an adaptive advantage in a coevolutionary arms race with vertically (maternally) transmitted pathogens. Similarly, the nuclear genome could be a source of compensatory mutations for its organellar genomes, as occurs in cytoplasmic male sterility in some plant species. We also discuss the possibility that adaptive cytoplasmic elements, such as favorable mitochondrial mutations or endosymbionts (e.g., Wolbachia), have the potential to release heritable nuclear variation as they sweep through a host population, supporting the view that cytoplasmic introgression plays an important role in adaptation and speciation.}, }
@article {pmid16738121, year = {2006}, author = {Kaltenpoth, M and Goettler, W and Dale, C and Stubblefield, JW and Herzner, G and Roeser-Mueller, K and Strohm, E}, title = {'Candidatus Streptomyces philanthi', an endosymbiotic streptomycete in the antennae of Philanthus digger wasps.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {56}, number = {Pt 6}, pages = {1403-1411}, doi = {10.1099/ijs.0.64117-0}, pmid = {16738121}, issn = {1466-5026}, mesh = {Animals ; Base Sequence ; Geography ; In Situ Hybridization, Fluorescence ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; *Phylogeny ; Streptomyces/*classification/genetics/isolation &amp; purification/physiology/ultrastructure ; Streptomycetaceae/*classification/genetics/isolation &amp; purification ; Symbiosis ; Wasps/*microbiology ; }, abstract = {Symbiotic interactions with bacteria are essential for the survival and reproduction of many insects. The European beewolf (Philanthus triangulum, Hymenoptera, Crabronidae) engages in a highly specific association with bacteria of the genus Streptomyces that appears to protect beewolf offspring against infection by pathogens. Using transmission and scanning electron microscopy, the bacteria were located in the antennal glands of female wasps, where they form dense cell clusters. Using genetic methods, closely related streptomycetes were found in the antennae of 27 Philanthus species (including two subspecies of P. triangulum from distant localities). In contrast, no endosymbionts could be detected in the antennae of other genera within the subfamily Philanthinae (Aphilanthops, Clypeadon and Cerceris). On the basis of morphological, genetic and ecological data, 'Candidatus Streptomyces philanthi' is proposed. 16S rRNA gene sequence data are provided for 28 ecotypes of 'Candidatus Streptomyces philanthi' that reside in different host species and subspecies of the genus Philanthus. Primers for the selective amplification of 'Candidatus Streptomyces philanthi' and an oligonucleotide probe for specific detection by fluorescence in situ hybridization (FISH) are described.}, }
@article {pmid16729848, year = {2006}, author = {Wu, D and Daugherty, SC and Van Aken, SE and Pai, GH and Watkins, KL and Khouri, H and Tallon, LJ and Zaborsky, JM and Dunbar, HE and Tran, PL and Moran, NA and Eisen, JA}, title = {Metabolic complementarity and genomics of the dual bacterial symbiosis of sharpshooters.}, journal = {PLoS biology}, volume = {4}, number = {6}, pages = {e188}, pmid = {16729848}, issn = {1545-7885}, mesh = {Amino Acids/biosynthesis/deficiency ; Animals ; Aphids/*metabolism/*microbiology ; Bacteroidetes/*metabolism ; Coenzymes/biosynthesis ; Evolution, Molecular ; Forecasting ; Genes, Bacterial ; Genome, Bacterial ; Genomics/methods ; Metabolic Networks and Pathways ; Models, Biological ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Single Nucleotide ; Sequence Analysis, DNA/methods ; Symbiosis/*genetics/*physiology ; Vitamins/biosynthesis ; }, abstract = {Mutualistic intracellular symbiosis between bacteria and insects is a widespread phenomenon that has contributed to the global success of insects. The symbionts, by provisioning nutrients lacking from diets, allow various insects to occupy or dominate ecological niches that might otherwise be unavailable. One such insect is the glassy-winged sharpshooter (Homalodisca coagulata), which feeds on xylem fluid, a diet exceptionally poor in organic nutrients. Phylogenetic studies based on rRNA have shown two types of bacterial symbionts to be coevolving with sharpshooters: the gamma-proteobacterium Baumannia cicadellinicola and the Bacteroidetes species Sulcia muelleri. We report here the sequencing and analysis of the 686,192-base pair genome of B. cicadellinicola and approximately 150 kilobase pairs of the small genome of S. muelleri, both isolated from H. coagulata. Our study, which to our knowledge is the first genomic analysis of an obligate symbiosis involving multiple partners, suggests striking complementarity in the biosynthetic capabilities of the two symbionts: B. cicadellinicola devotes a substantial portion of its genome to the biosynthesis of vitamins and cofactors required by animals and lacks most amino acid biosynthetic pathways, whereas S. muelleri apparently produces most or all of the essential amino acids needed by its host. This finding, along with other results of our genome analysis, suggests the existence of metabolic codependency among the two unrelated endosymbionts and their insect host. This dual symbiosis provides a model case for studying correlated genome evolution and genome reduction involving multiple organisms in an intimate, obligate mutualistic relationship. In addition, our analysis provides insight for the first time into the differences in symbionts between insects (e.g., aphids) that feed on phloem versus those like H. coagulata that feed on xylem. Finally, the genomes of these two symbionts provide potential targets for controlling plant pathogens such as Xylella fastidiosa, a major agroeconomic problem, for which H. coagulata and other sharpshooters serve as vectors of transmission.}, }
@article {pmid16720406, year = {2006}, author = {de Sassi, C and Müller, CB and Krauss, J}, title = {Fungal plant endosymbionts alter life history and reproductive success of aphid predators.}, journal = {Proceedings. Biological sciences}, volume = {273}, number = {1591}, pages = {1301-1306}, pmid = {16720406}, issn = {0962-8452}, mesh = {Animals ; Aphids/*physiology ; Body Size ; Coleoptera/anatomy &amp; histology/*growth &amp; development/*microbiology ; Fertility ; *Food Chain ; Hypocreales/*physiology ; Larva/growth &amp; development/microbiology/physiology ; Lolium/*microbiology ; Longevity ; Mycotoxins/metabolism ; Reproduction ; *Symbiosis ; }, abstract = {Endosymbionts occur in most plant species and may affect interactions among herbivores and their predators through the production of toxic alkaloids. Here, we ask whether effects of mycotoxins produced by the symbiosis of the fungal endophyte Neotyphodium lolii and the grass Lolium perenne are transmitted to the aphidophagous ladybird Coccinella septempunctata when feeding on cereal aphids Rhopalosiphum padi on infected plants. The larval development of coccinellids was extended, while their survival was reduced when feeding exclusively on aphids from infected plants. Ladybirds developing on aphids from infected plants showed reduced fecundity and impaired reproductive performance. Body size and symmetries of ladybird adults were not affected by the endophytes. Consistently strong, negative effects of endophytes on the lifetime performance of ladybirds indicates that mycotoxins are transmitted along food chains, causing significant damage for top predators. Such cascading effects will influence the population dynamics of aphid predators in the long term and could feedback to the primary plant producers.}, }
@article {pmid16710453, year = {2006}, author = {Bordenstein, SR and Marshall, ML and Fry, AJ and Kim, U and Wernegreen, JJ}, title = {The tripartite associations between bacteriophage, Wolbachia, and arthropods.}, journal = {PLoS pathogens}, volume = {2}, number = {5}, pages = {e43}, pmid = {16710453}, issn = {1553-7374}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteriophages/growth &amp; development/*physiology ; Female ; Gene Dosage ; Gram-Negative Bacterial Infections/microbiology ; Male ; Penetrance ; Spermatids/physiology ; Symbiosis/*physiology ; Wasps/microbiology/*physiology ; Wolbachia/genetics/growth &amp; development/*physiology ; }, abstract = {By manipulating arthropod reproduction worldwide, the heritable endosymbiont Wolbachia has spread to pandemic levels. Little is known about the microbial basis of cytoplasmic incompatibility (CI) except that bacterial densities and percentages of infected sperm cysts associate with incompatibility strength. The recent discovery of a temperate bacteriophage (WO-B) of Wolbachia containing ankyrin-encoding genes and virulence factors has led to intensifying debate that bacteriophage WO-B induces CI. However, current hypotheses have not considered the separate roles that lytic and lysogenic phage might have on bacterial fitness and phenotype. Here we describe a set of quantitative approaches to characterize phage densities and its associations with bacterial densities and CI. We enumerated genome copy number of phage WO-B and Wolbachia and CI penetrance in supergroup A- and B-infected males of the parasitoid wasp Nasonia vitripennis. We report several findings: (1) variability in CI strength for A-infected males is positively associated with bacterial densities, as expected under the bacterial density model of CI, (2) phage and bacterial densities have a significant inverse association, as expected for an active lytic infection, and (3) CI strength and phage densities are inversely related in A-infected males; similarly, males expressing incomplete CI have significantly higher phage densities than males expressing complete CI. Ultrastructural analyses indicate that approximately 12% of the A Wolbachia have phage particles, and aggregations of these particles can putatively occur outside the Wolbachia cell. Physical interactions were observed between approximately 16% of the Wolbachia cells and spermatid tails. The results support a low to moderate frequency of lytic development in Wolbachia and an overall negative density relationship between bacteriophage and Wolbachia. The findings motivate a novel phage density model of CI in which lytic phage repress Wolbachia densities and therefore reproductive parasitism. We conclude that phage, Wolbachia, and arthropods form a tripartite symbiotic association in which all three are integral to understanding the biology of this widespread endosymbiosis. Clarifying the roles of lytic and lysogenic phage development in Wolbachia biology will effectively structure inquiries into this research topic.}, }
@article {pmid16710420, year = {2006}, author = {Nussbaumer, AD and Fisher, CR and Bright, M}, title = {Horizontal endosymbiont transmission in hydrothermal vent tubeworms.}, journal = {Nature}, volume = {441}, number = {7091}, pages = {345-348}, doi = {10.1038/nature04793}, pmid = {16710420}, issn = {1476-4687}, mesh = {Animals ; Annelida/cytology/*microbiology/*physiology ; Apoptosis ; Bacteria/genetics/isolation &amp; purification ; Epidermis/microbiology ; *Hot Springs ; In Situ Hybridization, Fluorescence ; Larva/microbiology/physiology ; Mesoderm/microbiology ; *Symbiosis ; }, abstract = {Transmission of obligate bacterial symbionts between generations is vital for the survival of the host. Although the larvae of certain hydrothermal vent tubeworms (Vestimentifera, Siboglinidae) are symbiont-free and possess a transient digestive system, these structures are lost during development, resulting in adult animals that are nutritionally dependent on their bacterial symbionts. Thus, each generation of tubeworms must be newly colonized with its specific symbiont. Here we present a model for tubeworm symbiont acquisition and the development of the symbiont-housing organ, the trophosome. Our data indicate that the bacterial symbionts colonize the developing tube of the settled larvae and enter the host through the skin, a process that continues through the early juvenile stages during which the trophosome is established from mesodermal tissue. In later juvenile stages we observed massive apoptosis of host epidermis, muscles and undifferentiated mesodermal tissue, which was coincident with the cessation of the colonization process. Characterizing the symbiont transmission process in this finely tuned mutualistic symbiosis provides another model of symbiont acquisition and additional insights into underlying mechanisms common to both pathogenic infections and beneficial host-symbiont interactions.}, }
@article {pmid16706173, year = {2005}, author = {Galitskiĭ, VA}, title = {[The origin of eukaryotic cells and origination of apoptosis].}, journal = {Tsitologiia}, volume = {47}, number = {2}, pages = {103-120}, pmid = {16706173}, issn = {0041-3771}, mesh = {Animals ; Apoptosis/*physiology ; *Biological Evolution ; Chloroplasts ; Cytoplasm/physiology ; Cytoskeleton ; Eukaryotic Cells/cytology/*physiology ; Intracellular Membranes/physiology ; Mitochondria/physiology ; Oncogene Proteins ; Prokaryotic Cells/physiology ; Proto-Oncogene Proteins c-bcl-2/metabolism ; Signal Transduction ; Spindle Apparatus ; Symbiosis ; Tumor Suppressor Protein p53/metabolism ; Viral Proteins ; }, abstract = {The unified conception of the origin of eukaryotic cells has been proposed. In the author's opinion, evolutionary transformation of prokaryotic cell into eukaryotic cell took place 3.3-1.4 billion years ago and involved the next four stages: 1) the appearance of intracellular membranes due to prokaryotic cell plasmalemma invaginating into its cytoplasm; 2) the cell nucleus formation by the double sheet of intracellular membrane surrounding and sequestrating genetic material of the cell; 3) the appearance of cytoskeleton in parallel with mitotic spindle formation and gradual transition from prokaryotic way of cell division to mitosis; 4) the establishment of symbiosis between the evolving nucleated cell and prokaryotic microorganicsms that subsequently transform into mitochondria and chloroplasts. Apoptosis of cells of the present day multicellular eukaryotic organisms is supposed to be an evolutionary altered response of mitochondrian predecessors to the influence of factors, which are able to damage eukaryotic host cell. The initial biological significance of this reaction pertained to attempts of endosymbionts to leave the host cell as soon as possible, if the probability of its irreversible injury was very high, and by this to escape from their death. It is possible that numerous proteins, known as sensors or transducers of proapoptotic signals in Bcl-2--p53-dependent apoptotic pathway, were initially encoded by mitochondrial genome, whereas antiapoptotic factors and also components of receptor-mediated and granzyme B perforin dependent apoptotic pathways have cellular origin.}, }
@article {pmid16701327, year = {2004}, author = {Rand, DM and Haney, RA and Fry, AJ}, title = {Cytonuclear coevolution: the genomics of cooperation.}, journal = {Trends in ecology &amp; evolution}, volume = {19}, number = {12}, pages = {645-653}, doi = {10.1016/j.tree.2004.10.003}, pmid = {16701327}, issn = {0169-5347}, abstract = {Without mitochondria we would be in big trouble, and there would be a global biological energy crisis if it were not for chloroplasts. Fortunately, genomic evolution over the past two billion years has ensured that the functions of these key organelles are with us to stay. Whole-genome analyses have not only proven that mitochondria and chloroplasts are descended from formerly free-living bacteria, but have also shown that it is difficult to define eukaryotes without reference to the fusion and coevolution of host and endosymbiont genomes. Here, we review how the macro- and microevolutionary insights that follow from the genomics of cytonuclear interactions are uniting molecular evolution, structural proteomics, population genetics and problems in aging and disease. Our goals are to clarify the coevolutionary events that have governed nuclear and organelle evolution, and to encourage further critical analyses of these interactions as problems in the study of co-adapted gene complexes.}, }
@article {pmid16699169, year = {2006}, author = {Shalchian-Tabrizi, K and Skånseng, M and Ronquist, F and Klaveness, D and Bachvaroff, TR and Delwiche, CF and Botnen, A and Tengs, T and Jakobsen, KS}, title = {Heterotachy processes in rhodophyte-derived secondhand plastid genes: Implications for addressing the origin and evolution of dinoflagellate plastids.}, journal = {Molecular biology and evolution}, volume = {23}, number = {8}, pages = {1504-1515}, doi = {10.1093/molbev/msl011}, pmid = {16699169}, issn = {0737-4038}, mesh = {Animals ; Bayes Theorem ; Biological Evolution ; *DNA, Protozoan ; Dinoflagellida/*genetics ; Molecular Sequence Data ; Photosystem I Protein Complex/genetics ; Photosystem II Protein Complex/genetics ; *Phylogeny ; Plastids/*genetics ; Rhodophyta/*genetics ; Sequence Analysis, DNA ; }, abstract = {Serial transfer of plastids from one eukaryotic host to another is the key process involved in evolution of secondhand plastids. Such transfers drastically change the environment of the plastids and hence the selection regimes, presumably leading to changes over time in the characteristics of plastid gene evolution and to misleading phylogenetic inferences. About half of the dinoflagellate protists species are photosynthetic and unique in harboring a diversity of plastids acquired from a wide range of eukaryotic algae. They are therefore ideal for studying evolutionary processes of plastids gained through secondary and tertiary endosymbioses. In the light of these processes, we have evaluated the origin of 2 types of dinoflagellate plastids, containing the peridinin or 19'-hexanoyloxyfucoxanthin (19'-HNOF) pigments, by inferring the phylogeny using "covarion" evolutionary models allowing the pattern of among-site rate variation to change over time. Our investigations of genes from secondary and tertiary plastids derived from the rhodophyte plastid lineage clearly reveal "heterotachy" processes characterized as stationary covarion substitution patterns and changes in proportion of variable sites across sequences. Failure to accommodate covarion-like substitution patterns can have strong effects on the plastid tree topology. Importantly, multigene analyses performed with probabilistic methods using among-site rate and covarion models of evolution conflict with proposed single origin of the peridinin- and 19'-HNOF-containing plastids, suggesting that analysis of secondhand plastids can be hampered by convergence in the evolutionary signature of the plastid DNA sequences. Another type of sequence convergence was detected at protein level involving the psaA gene. Excluding the psaA sequence from a concatenated protein alignment grouped the peridinin plastid with haptophytes, congruent with all DNA trees. Altogether, taking account of complex processes involved in the evolution of dinoflagellate plastid sequences (both at the DNA and amino acid level), we demonstrate the difficulty of excluding independent, tertiary origin for both the peridinin and 19'-HNOF plastids involving engulfment of haptophyte-like algae. In addition, the refined topologies suggest the red algal order, Porphyridales, as the endosymbiont ancestor of the secondary plastids in cryptophytes, haptophytes, and heterokonts.}, }
@article {pmid16689936, year = {2006}, author = {Burri, L and Vascotto, K and Gentle, IE and Chan, NC and Beilharz, T and Stapleton, DI and Ramage, L and Lithgow, T}, title = {Integral membrane proteins in the mitochondrial outer membrane of Saccharomyces cerevisiae.}, journal = {The FEBS journal}, volume = {273}, number = {7}, pages = {1507-1515}, doi = {10.1111/j.1742-4658.2006.05171.x}, pmid = {16689936}, issn = {1742-464X}, mesh = {Amino Acid Sequence ; Membrane Proteins/*chemistry/genetics/metabolism ; Mitochondria/*metabolism/ultrastructure ; Mitochondrial Proteins/*chemistry/genetics/metabolism ; Molecular Sequence Data ; Protein Conformation ; Saccharomyces cerevisiae/*cytology/metabolism ; Saccharomyces cerevisiae Proteins/*chemistry/genetics/metabolism ; }, abstract = {Mitochondria evolved from a bacterial endosymbiont ancestor in which the integral outer membrane proteins would have been beta-barrel structured within the plane of the membrane. Initial proteomics on the outer membrane from yeast mitochondria suggest that while most of the protein components are integral in the membrane, most of these mitochondrial proteins behave as if they have alpha-helical transmembrane domains, rather than beta-barrels. These proteins are usually predicted to have a single alpha-helical transmembrane segment at either the N- or C-terminus, however, more complex topologies are also seen. We purified the novel outer membrane protein Om14 and show it is encoded in the gene YBR230c. Protein sequencing revealed an intron is spliced from the transcript, and both transcription from the YBR230c gene and steady-state level of the Om14 protein is dramatically less in cells grown on glucose than in cells grown on nonfermentable carbon sources. Hydropathy predictions together with data from limited protease digestion show three alpha-helical transmembrane segments in Om14. The alpha-helical outer membrane proteins provide functions derived after the endosymbiotic event, and require the translocase in the outer mitochondrial membrane complex for insertion into the outer membrane.}, }
@article {pmid16685282, year = {2006}, author = {Pool, JE and Wong, A and Aquadro, CF}, title = {Finding of male-killing Spiroplasma infecting Drosophila melanogaster in Africa implies transatlantic migration of this endosymbiont.}, journal = {Heredity}, volume = {97}, number = {1}, pages = {27-32}, pmid = {16685282}, issn = {0018-067X}, support = {R01 GM036431/GM/NIGMS NIH HHS/United States ; R01 GM036431-14/GM/NIGMS NIH HHS/United States ; GM36431/GM/NIGMS NIH HHS/United States ; }, mesh = {Aging ; Animal Migration ; Animals ; Drosophila melanogaster/*genetics/*microbiology/physiology ; Female ; Male ; Reproduction ; Sex Ratio ; Spiroplasma/*genetics/isolation &amp; purification/physiology ; Symbiosis ; Uganda ; Wolbachia/genetics/isolation &amp; purification/physiology ; }, abstract = {We report the identification of male-killing Spiroplasma in a wild-caught female Drosophila melanogaster from Uganda, the first such infection to be found in this species outside of South America. Among 38 female flies collected from Namulonge, Uganda in April, 2005, one produced a total of 41 female offspring but no males. PCR testing of subsequent generations revealed that females retaining Spiroplasma infection continued to produce a large excess of female progeny, while females that had lost Spiroplasma produced offspring with normal sex ratios. Consistent with earlier work, we find that male-killing and transmission efficiency appear to increase with female age, and we note that males born in sex ratio broods display much lower survivorship than their female siblings. DNA sequence comparisons at three loci suggest that this Spiroplasma strain is closely related to the male-killing strain previously found to infect D. melanogaster in Brazil, although part of one locus appears to show a recombinant history. Implications for the origin and history of male-killing Spiroplasma in D. melanogaster are discussed.}, }
@article {pmid16674583, year = {2006}, author = {Telschow, A and Engelstädter, J and Yamamura, N and Hammerstein, P and Hurst, GD}, title = {Asymmetric gene flow and constraints on adaptation caused by sex ratio distorters.}, journal = {Journal of evolutionary biology}, volume = {19}, number = {3}, pages = {869-878}, doi = {10.1111/j.1420-9101.2005.01049.x}, pmid = {16674583}, issn = {1010-061X}, mesh = {Acclimatization/*physiology ; Animal Migration ; Animals ; Birds/genetics/physiology ; Environment ; Female ; Gene Flow/*physiology ; Male ; Selection, Genetic ; Sex Ratio ; }, abstract = {Asymmetric gene flow is generally believed to oppose natural selection and potentially impede adaptation. Whilst the cause of asymmetric gene flow has been seen largely in terms of variation in population density over space, asymmetric gene flow can also result from varying sex ratios across subpopulations with similar population sizes. We model the process of adaptation in a scenario in which two adjacent subpopulations have different sex ratios, associated with different levels of infection with maternally inherited endosymbionts that selectively kill male hosts. Two models are analyzed in detail. First, we consider one host locus with two alleles, each of which possesses a selective advantage in one of the subpopulations. We found that local adaptation can strongly be impeded in the subpopulation with the more female biased population sex ratio. Second, we analyze host alleles that provide resistance against the male-killing (MK) endosymbionts and show that asymmetric gene flow can prevent the spread of such alleles under certain conditions. These results might have important implications for the coevolution of MK bacteria and their hosts.}, }
@article {pmid16673939, year = {2006}, author = {Mitreva-Dautova, M and Roze, E and Overmars, H and de Graaff, L and Schots, A and Helder, J and Goverse, A and Bakker, J and Smant, G}, title = {A symbiont-independent endo-1,4-beta-xylanase from the plant-parasitic nematode Meloidogyne incognita.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {19}, number = {5}, pages = {521-529}, doi = {10.1094/MPMI-19-0521}, pmid = {16673939}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Animals ; Cell Wall/chemistry ; Cellulases/chemistry ; Endo-1,4-beta Xylanases/*genetics ; Evolution, Molecular ; Gene Expression ; Genes, Helminth ; Host-Parasite Interactions ; Molecular Sequence Data ; Multigene Family ; Plants/parasitology ; Protein Structure, Secondary ; Sequence Alignment ; Sequence Homology, Amino Acid ; Tylenchida/*enzymology/genetics ; }, abstract = {Substituted xylan polymers constitute a major part of the hemicellulose fraction of plant cell walls, especially in monocotyledons. Endo-1,4-beta-xylanases (EC 3.2.1.8) are capable of hydrolyzing substituted xylan polymers into fragments of random size. Many herbivorous animals have evolved intimate relationships with endosymbionts to exploit their enzyme complexes for the degradation of xylan. Here, we report the first finding of a functional endo-1,4-beta-xylanase gene from an animal. The gene (Mi-xyl1) was found in the obligate plant-parasitic root-knot nematode Meloidogyne incognita, and encodes a protein that is classified as a member of glycosyl hydrolase family 5. The expression of Mi-xyl1 is localized in the subventral esophageal gland cells of the nematode. Previous studies have shown that M. incognita has the ability to degrade cellulose and pectic polysaccharides in plant cell walls independent of endosymbionts. Including our current data on Mi-xyl1, we show that the endogenous enzyme complex in root-knot nematode secretions targets essentially all major cell wall carbohydrates to facilitate a stealthy intercellular migration in the host plant.}, }
@article {pmid16672453, year = {2006}, author = {Sakamoto, JM and Feinstein, J and Rasgon, JL}, title = {Wolbachia infections in the Cimicidae: museum specimens as an untapped resource for endosymbiont surveys.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {5}, pages = {3161-3167}, pmid = {16672453}, issn = {0099-2240}, mesh = {Animals ; Cimicidae/classification/*microbiology ; DNA, Bacterial/analysis/isolation &amp; purification ; Molecular Sequence Data ; *Museums ; Phylogeny ; Polymerase Chain Reaction ; Prevalence ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/genetics/*isolation &amp; purification/*pathogenicity ; }, abstract = {Wolbachia spp. are obligate maternally inherited endosymbiotic bacteria that infect diverse arthropods and filarial nematodes. Previous microscopic and molecular studies have identified Wolbachia in several bed bug species (Cimicidae), but little is known about how widespread Wolbachia infections are among the Cimicidae. Because cimicids of non-medical importance are not commonly collected, we hypothesized that preserved museum specimens could be assayed for Wolbachia infections. For the screening of museum specimens, we designed a set of primers that specifically amplify small diagnostic fragments (130 to 240 bp) of the Wolbachia 16S rRNA gene. Using these and other previously published primers, we screened 39 cimicid species (spanning 16 genera and all 6 recognized subfamilies) and 2 species of the sister family Polyctenidae for Wolbachia infections using museum and wild-caught material. Amplified fragments were sequenced to confirm that our primers were amplifying Wolbachia DNA. We identified 10 infections, 8 of which were previously undescribed. Infections in the F supergroup were common in the subfamily Cimicinae, while infections in the A supergroup were identified in the subfamilies Afrocimicinae and Haematosiphoninae. Even though specimens were degraded, we detected infections in over 23% of cimicid species. Our results indicate that Wolbachia infections may be common among cimicids and that archived museum material is a useful untapped resource for invertebrate endosymbiont surveys. The new screening primers listed in this report will be useful for other researchers conducting Wolbachia surveys with specimens with less-than-optimum DNA quality.}, }
@article {pmid16638123, year = {2006}, author = {Erdner, DL and Anderson, DM}, title = {Global transcriptional profiling of the toxic dinoflagellate Alexandrium fundyense using Massively Parallel Signature Sequencing.}, journal = {BMC genomics}, volume = {7}, number = {}, pages = {88}, pmid = {16638123}, issn = {1471-2164}, support = {P50 ES012742/ES/NIEHS NIH HHS/United States ; 1 P50 ES012742-01/ES/NIEHS NIH HHS/United States ; }, mesh = {Animals ; Arabidopsis/genetics ; Biological Evolution ; Dinoflagellida/*genetics/growth &amp; development/metabolism ; Expressed Sequence Tags ; Gene Expression Profiling/*methods ; Gene Library ; Genome ; Humans ; Sequence Analysis, DNA/*methods ; Species Specificity ; *Transcription, Genetic ; }, abstract = {BACKGROUND: Dinoflagellates are one of the most important classes of marine and freshwater algae, notable both for their functional diversity and ecological significance. They occur naturally as free-living cells, as endosymbionts of marine invertebrates and are well known for their involvement in "red tides". Dinoflagellates are also notable for their unusual genome content and structure, which suggests that the organization and regulation of dinoflagellate genes may be very different from that of most eukaryotes. To investigate the content and regulation of the dinoflagellate genome, we performed a global analysis of the transcriptome of the toxic dinoflagellate Alexandrium fundyense under nitrate- and phosphate-limited conditions using Massively Parallel Signature Sequencing (MPSS).<br><br>RESULTS: Data from the two MPSS libraries showed that the number of unique signatures found in A. fundyense cells is similar to that of humans and Arabidopsis thaliana, two eukaryotes that have been extensively analyzed using this method. The general distribution, abundance and expression patterns of the A. fundyense signatures were also quite similar to other eukaryotes, and at least 10% of the A. fundyense signatures were differentially expressed between the two conditions. RACE amplification and sequencing of a subset of signatures showed that multiple signatures arose from sequence variants of a single gene. Single signatures also mapped to different sequence variants of the same gene.<br><br>CONCLUSION: The MPSS data presented here provide a quantitative view of the transcriptome and its regulation in these unusual single-celled eukaryotes. The observed signature abundance and distribution in Alexandrium is similar to that of other eukaryotes that have been analyzed using MPSS. Results of signature mapping via RACE indicate that many signatures result from sequence variants of individual genes. These data add to the growing body of evidence for widespread gene duplication in dinoflagellates, which would contribute to the transcriptional complexity of these organisms. The MPSS data also demonstrate that a significant number of dinoflagellate mRNAs are transcriptionally regulated, indicating that dinoflagellates commonly employ transcriptional gene regulation along with the post-transcriptional regulation that has been well documented in these organisms.}, }
@article {pmid16623396, year = {2006}, author = {DeChaine, EG and Cavanaugh, CM}, title = {Symbioses of methanotrophs and deep-sea mussels (Mytilidae: Bathymodiolinae).}, journal = {Progress in molecular and subcellular biology}, volume = {41}, number = {}, pages = {227-249}, doi = {10.1007/3-540-28221-1_11}, pmid = {16623396}, issn = {0079-6484}, mesh = {Animals ; Euryarchaeota/*metabolism ; Host-Parasite Interactions ; Methane/*metabolism ; Mytilidae/metabolism/*microbiology/ultrastructure ; Nutritional Physiological Phenomena ; *Seawater ; *Symbiosis ; }, abstract = {The symbioses between invertebrates and chemosynthetic bacteria allow both host and symbiont to colonize and thrive in otherwise inhospitable deep-sea habitats. Given the global distribution of the bathymodioline symbioses, this association is an excellent model for evaluating co-speciation and evolution of symbioses. Thus far, the methanotroph and chemoautotroph endosymbionts of mussels are tightly clustered within two independent clades of gamma Proteobacteria, respectively. Further physiological and genomic studies will elucidate the ecological and evolutionary roles that these bacterial clades play in the symbiosis and chemosynthetic community. Due to the overall abundance of the methanotrophic symbioses at hydrothermal vents and hydrocarbon seeps, they likely play a significant, but as of yet unquantified, role in the biogeochemical cycling of methane. With this in mind, the search for methanotrophic symbioses should not be restricted to these known deep-sea habitats, but rather should be expanded to include methane-rich coastal marine and freshwater environments inhabited by methanotrophs and bivalves. Our current understanding of the bathymodioline symbioses provides a strong foundation for future explorations into the origin, ecology, and evolution of methanotroph symbioses, which are now becoming possible through a combination of classical and advanced molecular techniques.}, }
@article {pmid16608447, year = {2006}, author = {Lumini, E and Ghignone, S and Bianciotto, V and Bonfante, P}, title = {Endobacteria or bacterial endosymbionts? To be or not to be.}, journal = {The New phytologist}, volume = {170}, number = {2}, pages = {205-208}, doi = {10.1111/j.1469-8137.2006.01673.x}, pmid = {16608447}, issn = {0028-646X}, mesh = {*Bacterial Physiological Phenomena ; Burkholderiaceae/physiology/ultrastructure ; DNA, Ribosomal/classification ; Fungi/*physiology ; Mycorrhizae/physiology/ultrastructure ; Phylogeny ; Plant Diseases/microbiology ; Rhizopus/physiology ; *Symbiosis ; }, }
@article {pmid16601001, year = {2006}, author = {Toft, C and Fares, MA}, title = {GRAST: a new way of genome reduction analysis using comparative genomics.}, journal = {Bioinformatics (Oxford, England)}, volume = {22}, number = {13}, pages = {1551-1561}, doi = {10.1093/bioinformatics/btl139}, pmid = {16601001}, issn = {1367-4803}, mesh = {Algorithms ; Animals ; Aphids ; Computational Biology/*methods ; Databases, Genetic ; Evolution, Molecular ; *Genome ; Genome, Bacterial ; Genomics/*methods ; Models, Genetic ; Models, Statistical ; Multigene Family ; Software ; }, abstract = {MOTIVATION: Establishment of intra-cellular life involved a profound re-configuration of the genetic characteristics of bacteria, including genome reduction and rearrangements. Understanding the mechanisms underlying these phenomena will shed light on the genome rearrangements essential for the development of an intra-cellular lifestyle. Comparison of genomes with differences in their sizes poses statistical as well as computational problems. Little efforts have been made to develop flexible computational tools with which to analyse genome reduction and rearrangements.<br><br>RESULTS: Investigation of genome reduction and rearrangements in endosymbionts using a novel computational tool (GRAST) identified gathering of genes with similar functions. Conserved clusters of functionally related genes (CGSCs) were detected. Heterogeneous gene and gene cluster non-functionalization/loss are identified between genome regions, functional gene categories and during evolution. Results show that gene non-functionalisation has accelerated during the last 50 MY of Buchnera's evolution while CGSCs have been static.}, }
@article {pmid16598010, year = {2006}, author = {Ainsworth, TD and Fine, M and Blackall, LL and Hoegh-Guldberg, O}, title = {Fluorescence in situ hybridization and spectral imaging of coral-associated bacterial communities.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {4}, pages = {3016-3020}, pmid = {16598010}, issn = {0099-2240}, mesh = {Animals ; Anthozoa/*microbiology/parasitology/*physiology ; Bacteria/growth &amp; development/*metabolism ; Carbocyanines/*analysis ; Fluorescence ; Fluorescent Dyes/*analysis ; Image Processing, Computer-Assisted ; In Situ Hybridization, Fluorescence/*methods ; Microscopy, Confocal ; Snails/physiology ; Symbiosis ; }, abstract = {Microbial communities play important roles in the functioning of coral reef communities. However, extensive autofluorescence of coral tissues and endosymbionts limits the application of standard fluorescence in situ hybridization (FISH) techniques for the identification of the coral-associated bacterial communities. This study overcomes these limitations by combining FISH and spectral imaging.}, }
@article {pmid16598007, year = {2006}, author = {Dale, C and Beeton, M and Harbison, C and Jones, T and Pontes, M}, title = {Isolation, pure culture, and characterization of "Candidatus Arsenophonus arthropodicus," an intracellular secondary endosymbiont from the hippoboscid louse fly Pseudolynchia canariensis.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {4}, pages = {2997-3004}, pmid = {16598007}, issn = {0099-2240}, mesh = {Aedes ; Animals ; Cell Line ; Culture Media ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Diptera/growth &amp; development/*microbiology ; *Enterobacteriaceae/classification/genetics/growth &amp; development/isolation &amp; purification ; Molecular Sequence Data ; Phylogeny ; Pupa/microbiology ; RNA, Ribosomal, 16S ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Members of the genus Arsenophonus comprise a large group of bacterial endosymbionts that are widely distributed in arthropods of medical, veterinary, and agricultural importance. At present, little is known about the role of these bacteria in arthropods, because few representatives have been isolated and cultured in the laboratory. In the current study, we describe the isolation and pure culture of an Arsenophonus endosymbiont from the hippoboscid louse fly Pseudolynchia canariensis. We propose provisional nomenclature for this bacterium in the genus Arsenophonus as "Candidatus Arsenophonus arthropodicus." Phylogenetic analyses indicate that "Candidatus Arsenophonus arthropodicus" is closely related to the Arsenophonus endosymbionts found in psyllids, whiteflies, aphids, and mealybugs. The pure culture of this endosymbiont offers new opportunities to examine the role of Arsenophonus in insects. To this end, we describe methods for the culture of "Candidatus Arsenophonus arthropodicus" in an insect cell line and the transformation of this bacterium with a broad-host-range plasmid.}, }
@article {pmid16597203, year = {2006}, author = {Hoerauf, A}, title = {New strategies to combat filariasis.}, journal = {Expert review of anti-infective therapy}, volume = {4}, number = {2}, pages = {211-222}, doi = {10.1586/14787210.4.2.211}, pmid = {16597203}, issn = {1744-8336}, mesh = {Animals ; Doxycycline/*administration &amp; dosage/therapeutic use ; Drug Delivery Systems/methods/*trends ; Filariasis/*drug therapy/microbiology ; Filaricides/*administration &amp; dosage/therapeutic use ; Humans ; }, abstract = {Two of the major filarial infections, lymphatic filariasis (LF) and onchocerciasis, affect 150 million people, while 1 billion living in endemic areas are at risk of infection. Public health programs to control these infections have successfully existed for years and have evolved from activities driven by the WHO into global programs with public-private partnerships. Currently, these programs use yearly mass application of drugs that mainly kill the larval stages (the microfilariae), with the aim of preventing uptake by the transmitting insect vectors and thus, to block transmission and reduce the infections to such levels that in 15-30 years from now, they will no longer pose a public health problem. While the programs have been very successful in general, there are drawbacks such as coverage being too low within the population, reappearance of infection by migration of infected people into controlled areas, targeting of a stage (the microfilaria) that does not induce pathology in LF and thus lowers compliance, and the potential development of drug resistance, first indications of which have been clearly observed in onchocerciasis. In addition, even without drawbacks, program scopes are not the eradication of filarial infections, which is, however, an ultimate goal of control activities. There is therefore an unequivocal call for the development of higher efficient, complementary chemotherapeutical approaches that lead to a long-lasting reduction of the pathology-inducing worm stages; that is, microfilariae in onchocerciasis and adult worms in LF, or to a macrofilaricidal effect. The recent discovery that depletion of Wolbachia endosymbionts by tetracycline antibiotics leads to long-lasting sterility of adult female worms in onchocerciasis and a macrofilaricidal effect in LF fulfils these requirements. Successful regimens have already been published and agreed upon for use by expert panels. While these regimens are still too long for mass application, the antiwolbachial chemotherapy can currently be applied in the form of a suitable doxycycline regimen for 6 weeks for the treatment of individuals, and exploited in the future for the development of new drugs suitable for mass application. In addition, first data suggest that Wolbachia may also be major mediators of lymphangiogenesis and that their depletion is associated with reduction of lymph vessel-specific vascular endothelial growth factors and reduced lymph vessel size.}, }
@article {pmid16596351, year = {2006}, author = {Reeves, WK and Dowling, AP and Dasch, GA}, title = {Rickettsial agents from parasitic dermanyssoidea (Acari: Mesostigmata).}, journal = {Experimental &amp; applied acarology}, volume = {38}, number = {2-3}, pages = {181-188}, pmid = {16596351}, issn = {0168-8162}, mesh = {Anaplasma/genetics/isolation &amp; purification ; Animals ; Bartonella/genetics/isolation &amp; purification ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; Gram-Negative Bacteria/genetics/*isolation &amp; purification ; Mites/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/chemistry/genetics ; Rickettsia/genetics/isolation &amp; purification ; Sequence Analysis, DNA ; Spiroplasma/genetics/isolation &amp; purification ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {Mites are often overlooked as vectors of pathogens, but have been shown to harbor and transmit rickettsial agents such as Rickettsia akari and Orientia tsutsugamushi. We screened DNA extracts from 27 mites representing 25 species of dermanyssoids for rickettsial agents such as Anaplasma, Bartonella, Rickettsia, and Wolbachia by PCR amplification and sequencing. DNA from Anaplasma spp., a novel Bartonella sp., Spiroplasma sp., Wolbachia sp., and an unclassified Rickettsiales were detected in mites. These could represent mite-borne bacterial agents, bacterial DNA from blood meals, or novel endosymbionts of mites.}, }
@article {pmid16575724, year = {2006}, author = {Turner, JD and Mand, S and Debrah, AY and Muehlfeld, J and Pfarr, K and McGarry, HF and Adjei, O and Taylor, MJ and Hoerauf, A}, title = {A randomized, double-blind clinical trial of a 3-week course of doxycycline plus albendazole and ivermectin for the treatment of Wuchereria bancrofti infection.}, journal = {Clinical infectious diseases : an official publication of the Infectious Diseases Society of America}, volume = {42}, number = {8}, pages = {1081-1089}, doi = {10.1086/501351}, pmid = {16575724}, issn = {1537-6591}, mesh = {Adolescent ; Adult ; Aged ; Albendazole/*therapeutic use ; Animals ; Anthelmintics/therapeutic use ; Double-Blind Method ; Doxycycline/*therapeutic use ; Drug Therapy, Combination ; Filariasis/*drug therapy ; Ghana ; Humans ; Ivermectin/*therapeutic use ; Middle Aged ; Patient Dropouts ; *Wuchereria bancrofti ; }, abstract = {BACKGROUND: Eight- and 6-week courses of doxycycline are superior to standard treatment of bancroftian filariasis. Standard treatment (albendazole plus ivermectin) is associated with adverse reactions. We assessed whether a shorter (i.e, 3-week) course of doxycycline with standard treatment would show superior efficacy to standard treatment alone and reduce the incidence of adverse reactions.<br><br>METHODS: A total of 44 adults from Ghana were recruited in January 2003: 20 received doxycycline (200 mg/day) for 3 weeks, and 24 received matching placebo. Participants received albendazole (400 mg) and ivermectin (150 microg/kg) at month 4, and adverse reactions were assessed 48 h later. Treatment efficacy was evaluated at months 4, 12, and 24.<br><br>RESULTS: The microfilariae level was significantly reduced after receipt of doxycycline treatment at months 4 (P = .017), 12 (P = .001), and 24 (P = .005). The microfilariae level was only significantly reduced at month 12 in the placebo group (P = .041). At all follow-up points, the microfilariae level was significantly lower in the doxycycline group. Adverse reactions to standard antifilarial treatment were similar in frequency between the doxycycline group (in 7 of 11 subjects) and the placebo group (in 13 of 17 subjects). Moderate reactions only occurred in the placebo group (in 3 of 17 subjects). Severity of adverse reaction was associated with microfilaremia (P = .037), Wolbachia bacteria in plasma (P = .048), and proinflammatory cytokines in plasma (P = .019). Adult parasite viability was not significantly different between doxycycline and placebo groups at months 12 or 24.<br><br>CONCLUSIONS: Treatment with doxycycline for 3 weeks is more effective in inducing a long-term amicrofilaremia than is standard treatment alone, but it is ineffective at inducing curative effects. Inflammatory reactions to antifilarial treatment are associated with levels of microfilariae and Wolbachia endosymbionts released into plasma.}, }
@article {pmid16572337, year = {2006}, author = {Corrêa-da-Silva, MS and Fampa, P and Lessa, LP and Silva, Edos R and dos Santos Mallet, JR and Saraiva, EM and Motta, MC}, title = {Colonization of Aedes aegypti midgut by the endosymbiont-bearing trypanosomatid Blastocrithidia culicis.}, journal = {Parasitology research}, volume = {99}, number = {4}, pages = {384-391}, pmid = {16572337}, issn = {0932-0113}, mesh = {Aedes/*parasitology/ultrastructure ; Animals ; Female ; Host-Parasite Interactions ; Insect Vectors/*parasitology/ultrastructure ; Intestines/*parasitology/ultrastructure ; Life Cycle Stages/*physiology ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Symbiosis ; Trypanosomatina/*physiology/ultrastructure ; }, abstract = {Monoxenous trypanosomatids inhabit invertebrate hosts throughout their life cycle. However, there have been cases of HIV-positive patients who have presented opportunistic infections caused by these protozoa, offering new perspectives to the study of interactions between monoxenics and hematophagous insect vectors. Some monoxenous trypanosomatids present a symbiotic bacterium in the cytoplasm, which seems to promote biochemical and morphological changes in the host trypanosomatids, such as alterations in plasma membrane carbohydrates and the reduction of the paraxial rod. In this work, we investigated the colonization of Aedes aegypti with Blastocrithidia culicis, an endosymbiont-bearing trypanosomatid. B. culicis remained in the insect digestive tract for 38 days after feeding. Optical microscopy analysis revealed an infection process characterized by a homogenous distribution of the trypanosomatid along the midgut epithelium; no preferential interaction of protozoa with any cell type was observed. Ultrastructural analysis showed that during the colonization process, trypanosomatids interacted mainly with midgut cells through their flagellum, which penetrates the microvilli preferentially near the tight junctions. Prolonged infections promoted insect midgut degradation, culminating with the arrival of protozoa in the hemocel. By demonstrating B. culicis colonization in a bloodsucking insect, we suggest that vector transmission of monoxenous trypanosomatids to vertebrate host may occur in nature.}, }
@article {pmid16570126, year = {2006}, author = {Tanifuji, G and Erata, M and Ishida, K and Onodera, N and Hara, Y}, title = {Diversity of secondary endosymbiont-derived actin-coding genes in cryptomonads and their evolutionary implications.}, journal = {Journal of plant research}, volume = {119}, number = {3}, pages = {205-215}, pmid = {16570126}, issn = {0918-9440}, mesh = {Actins/*genetics ; Base Sequence ; Cryptophyta/*genetics/*metabolism ; *Evolution, Molecular ; Gene Expression Regulation, Plant ; *Genetic Variation ; Phylogeny ; Symbiosis/genetics ; }, abstract = {In the secondary endosymbiotic organisms of cryptomonads, the symbiont actin genes have been found together with the host one. To examine whether they are commonly conserved and where they are encoded, host and symbiont actin genes from Pyrenomonas helgolandii were isolated, and their specific and homologous regions were digoxigenin (DIG) labeled separately. Using these probes, Southern hybridization was performed on 13 species of cryptomonads. They were divided into three groups: (1) both host and symbiont actin gene signals were detected, (2) only the host actin gene signal was detected, and (3) host and unknown actin signals were detected. The phylogenetic analysis of these actin gene sequences indicated that the evolutionary rates of the symbiont actin genes were accelerated more than those of the hosts. The unknown actin signals were recognized as the highly diverged symbiont actin genes. One of the diverged symbiont actin sequences from Guillardia theta is presumed to be as a pseudogene or to its precursor. Southern hybridizations based on the samples divided by pulsed-field gel electrophoresis showed that all actin genes were encoded by the host nuclei. These results possibly represent the evolutionary fate of the symbiont actin gene in cryptomonads, which was firstly transferred from the symbiont nucleus or nucleomorph, to the host nucleus and became a pseudogene and then finally disappeared there.}, }
@article {pmid16566221, year = {2005}, author = {Chen, HY and Jiang, QW and Li, QX and Li, ZH}, title = {[A micro-culture method for continuous observation of free-living amoebae].}, journal = {Zhongguo ji sheng chong xue yu ji sheng chong bing za zhi = Chinese journal of parasitology &amp; parasitic diseases}, volume = {23}, number = {6}, pages = {453-455}, pmid = {16566221}, issn = {1000-7423}, mesh = {Amoeba/*growth &amp; development/physiology ; Animals ; Candida albicans ; Coculture Techniques ; Culture Media ; Phagocytosis ; Temperature ; }, abstract = {OBJECTIVE: To establish a method for co-culture of amoebae and endosymbionts, also for continuously observing the microphenotype of amoebae.<br><br>METHODS: 24 wells culture plate with cover glass on the wells was used as containers. Amoebae and Candida albicans were co-cultured in microdrop of medium in the wells at 37 degrees C, and observed under x1000.<br><br>RESULTS: Continuous observation revealed trophozoites in various shapes like letters T, K, or Y, their movement and ingestion phenomenon were observed.<br><br>CONCLUSION: The micro-culture method is useful in observing the amoebal morphology and its phagocytic process to Candida albicans.}, }
@article {pmid16563429, year = {2006}, author = {Zeh, JA and Zeh, DW}, title = {Male-killing Wolbachia in a live-bearing arthropod: brood abortion as a constraint on the spread of a selfish microbe.}, journal = {Journal of invertebrate pathology}, volume = {92}, number = {1}, pages = {33-38}, doi = {10.1016/j.jip.2006.02.004}, pmid = {16563429}, issn = {0022-2011}, mesh = {Animals ; Arthropods/*parasitology ; Female ; Host-Parasite Interactions ; Male ; *Sex Ratio ; Wolbachia/*physiology ; }, abstract = {Maternally inherited, cellular endosymbionts can enhance their fitness by biasing host sex ratio in favor of females. Male killing (MK), an extreme form of sex-ratio manipulation, is selectively advantageous, if the death of males results in increased microbe transmission through female siblings. In live-bearing hosts, females typically produce more embryos than are brought to term, and reproductive compensation through maternal resource reallocation from dead male embryos to female siblings provides a direct, physiological mechanism that could increase the number of daughters born to infected females, thereby promoting MK endosymbiont spread. In this study, a Wolbachia-infected line and an uninfected line of the viviparous pseudoscorpion, Cordylochernes scorpioides were genetically homogenized for nuclear DNA by repeated backcrossing of the infected line with the uninfected, laboratory population. Photomicroscopy of early-stage embryos demonstrated that female C. scorpioides invariably produced an excess of embryos, with Wolbachia-infected females producing as many early-stage embryos as uninfected female controls. However, Wolbachia-infected females that successfully carried broods to term gave birth to significantly fewer offspring, indicating that the extreme female bias characteristic of their broods results from the killing rather than the feminization of male embryos. Infected females that carried broods to term gave birth to significantly larger nymphs and did produce 10% more female offspring than uninfected females. However, the slight transmission advantage that the MK Wolbachia accrued from this reproductive compensation appears to be heavily outweighed by the high rate of spontaneous brood abortion suffered by infected females.}, }
@article {pmid16563157, year = {2006}, author = {Townson, S and Tagboto, S and McGarry, HF and Egerton, GL and Taylor, MJ}, title = {Onchocerca parasites and Wolbachia endosymbionts: evaluation of a spectrum of antibiotic types for activity against Onchocerca gutturosa in vitro.}, journal = {Filaria journal}, volume = {5}, number = {}, pages = {4}, pmid = {16563157}, issn = {1475-2883}, abstract = {BACKGROUND: The filarial parasites of major importance in humans contain the symbiotic bacterium Wolbachia and recent studies have shown that targeting of these bacteria with antibiotics results in a reduction in worm viability, development, embryogenesis, and survival. Doxycycline has been effective in human trials, but there is a need to develop drugs that can be given for shorter periods and to pregnant women and children. The World Health Organisation-approved assay to screen for anti-filarial activity in vitro uses male Onchocerca gutturosa, with effects being determined by worm motility and viability as measured by reduction of MTT to MTT formazan. Here we have used this system to screen antibiotics for anti-filarial activity. In addition we have determined the contribution of Wolbachia depletion to the MTT reduction assay.<br><br>METHODS: Adult male O. gutturosa were cultured on a monkey kidney cell (LLCMK 2) feeder layer in 24-well plates with antibiotics and antibiotic combinations (6 to 10 worms per group). The macrofilaricide CGP 6140 (Amocarzine) was used as a positive control. Worm viability was assessed by two methods, (i) motility levels and (ii) MTT/formazan colorimetry. Worm motility was scored on a scale of 0 (immotile) to 10 (maximum) every 5 days up to 40 days. On day 40 worm viability was evaluated by MTT/formazan colorimetry, and results were expressed as a mean percentage reduction compared with untreated control values at day 40. To determine the contribution of Wolbachia to the MTT assay, the MTT formazan formation of an insect cell-line (C6/36) with or without insect Wolbachia infection and treated or untreated with tetracycline was compared.<br><br>RESULTS: Antibiotics with known anti-Wolbachia activity were efficacious in this system. Rifampicin (5 x 10(-5) M) was the most effective anti-mycobacterial agent; clofazimine (1.25 x 10(-5) M and 3.13 x 10(-6) M) produced a gradual reduction in motility and by 40 days had reduced worm viability. The other anti-mycobacterial drugs tested had limited or no activity. Doxycycline (5 x 10(-5) M) was filaricidal, but minocycline was more effective and at a lower concentration (5 x 10(-5) M and 1.25 x 10(-5) M). Inactive compounds included erythromycin, oxytetracycline, trimethoprim and sulphamethoxazole. The MTT assay on the insect cell-line showed that Wolbachia made a significant contribution to the metabolic activity within the cells, which could be reduced when they were exposed to tetracycline.<br><br>CONCLUSION: The O. gutturosa adult male screen for anti-filarial drug activity is also valid for the screening of antibiotics for anti-Wolbachia activity. In agreement with previous findings, rifampicin and doxycycline were effective; however, the most active antibiotic was minocycline. Wolbachia contributed to the formation of MTT formazan in the MTT assay of viability and is therefore not exclusively a measure of worm viability and indicates that Wolbachia contributes directly to the metabolic activity of the nematode.}, }
@article {pmid16553848, year = {2006}, author = {Lourenço, EE and Cavalcanti, DP and Assine Picchi, GF and Souza, W and Aurélio Krieger, M and Machado Motta, MC and Goldenberg, S and Perdigão Fragoso, S}, title = {Molecular characterization of type II topoisomerase in the endosymbiont-bearing Trypanosomatid Blastocrithidia culicis.}, journal = {FEMS microbiology letters}, volume = {257}, number = {1}, pages = {163-170}, doi = {10.1111/j.1574-6968.2006.00164.x}, pmid = {16553848}, issn = {0378-1097}, mesh = {Amino Acid Sequence ; Animals ; Cell Nucleus/enzymology/ultrastructure ; *DNA Topoisomerases, Type II/chemistry/genetics/isolation &amp; purification/metabolism ; Humans ; Immunohistochemistry ; Molecular Sequence Data ; Sequence Alignment ; Trypanosomatina/*enzymology/genetics/ultrastructure ; }, abstract = {DNA topoisomerases are involved in DNA metabolism. These enzymes are inhibited by antimicrobial and antitumoral agents and might be important targets in the chemotherapy of diseases caused by parasites. We have cloned and characterized the gene encoding topoisomerase II from the monoxenic trypanosomatid Blastocrithidia culicis (BcTOP2). The BcTOP2 gene has a 3693 nucleotide-long open reading frame that encodes a 138 kDa polypeptide. The B. culicis topoisomerase II (BctopoII) amino-acid sequence shares high similarity (>74%) with topoisomerases from other trypanosomatids, and shares a lower similarity (41%) with other eukaryotic topoisomerases II from yeast to humans. BcTOP2 is a single copy gene and encodes a 4.4 kb mRNA. Western blotting of B. culicis extracts using the antiserum raised against a C-terminal portion of BctopoII showed a 138 kDa polypeptide. Immunolocalization assays showed that the antiserum recognized the nuclear topoisomerase II.}, }
@article {pmid16552514, year = {2006}, author = {Dishaw, LJ and Herrera, ML and Bigger, CH}, title = {Characterization and phylogenetic analysis of a cnidarian LMP X-like cDNA.}, journal = {Immunogenetics}, volume = {58}, number = {5-6}, pages = {454-464}, pmid = {16552514}, issn = {0093-7711}, support = {GM061347/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Anthozoa/*enzymology/genetics/*immunology ; DNA, Complementary/genetics ; Evolution, Molecular ; Hydrophobic and Hydrophilic Interactions ; Major Histocompatibility Complex/*immunology ; Molecular Sequence Data ; Multienzyme Complexes/classification/genetics ; Phylogeny ; Proteasome Endopeptidase Complex/*classification/*genetics ; Protein Subunits/classification/genetics ; }, abstract = {Proteasomes are multisubunit protease complexes which are partly responsible for metabolism of intracellular, ubiquitinylated proteins. Vertebrates have adapted a second and specialized structure responsible for the generation of peptides presented to the adaptive immune system and is thus, commonly referred to as the immunoproteasome. This complex is assembled from paralogous copies of subunits belonging to the constitutive, housekeeping proteasome. The immunoproteasome is more efficient in the generation of peptides for display on major histocompatibility complex (MHC) molecules. Important components of this complex are the paralogous members, LMP X and 7; where the latter replaces the former in the assembly of the immunoproteasome of vertebrates. In this report, we describe an LMP X-like cDNA from an endosymbiont-free gorgonian coral, Swiftia exserta. Cnidarians predate the phylogenetic divergence of protostomes and deuterostomes (P-D split), and are becoming an essential model for our comprehension of immune system evolution. Phylogenetic analyses of available sequences indicates that invertebrate LMP X-like sequences are outgroups to vertebrate LMP X and LMP 7, and is in agreement with previous observations that the duplication event giving rise to the two rapidly diverging lineages of proteasomal subunits occurred before jawed fished divergence.}, }
@article {pmid16547129, year = {2006}, author = {Mergaert, P and Uchiumi, T and Alunni, B and Evanno, G and Cheron, A and Catrice, O and Mausset, AE and Barloy-Hubler, F and Galibert, F and Kondorosi, A and Kondorosi, E}, title = {Eukaryotic control on bacterial cell cycle and differentiation in the Rhizobium-legume symbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {103}, number = {13}, pages = {5230-5235}, pmid = {16547129}, issn = {0027-8424}, mesh = {*Cell Cycle ; Cell Enlargement ; DNA, Bacterial/genetics ; Eukaryotic Cells/*physiology ; Fabaceae/classification/*physiology ; Genome, Bacterial/genetics ; Rhizobium/*cytology/physiology ; Symbiosis ; }, abstract = {Symbiosis between legumes and Rhizobium bacteria leads to the formation of root nodules where bacteria in the infected plant cells are converted into nitrogen-fixing bacteroids. Nodules with a persistent meristem are indeterminate, whereas nodules without meristem are determinate. The symbiotic plant cells in both nodule types are polyploid because of several cycles of endoreduplication (genome replication without mitosis and cytokinesis) and grow consequently to extreme sizes. Here we demonstrate that differentiation of bacteroids in indeterminate nodules of Medicago and related legumes from the galegoid clade shows remarkable similarity to host cell differentiation. During bacteroid maturation, repeated DNA replication without cytokinesis results in extensive amplification of the entire bacterial genome and elongation of bacteria. This finding reveals a positive correlation in prokaryotes between DNA content and cell size, similar to that in eukaryotes. These polyploid bacteroids are metabolically functional but display increased membrane permeability and are nonviable, because they lose their ability to resume growth. In contrast, bacteroids in determinate nodules of the nongalegoid legumes lotus and bean are comparable to free-living bacteria in their genomic DNA content, cell size, and viability. Using recombinant Rhizobium strains nodulating both legume types, we show that bacteroid differentiation is controlled by the host plant. Plant factors present in nodules of galegoid legumes but absent from nodules of nongalegoid legumes block bacterial cell division and trigger endoreduplication cycles, thereby forcing the endosymbionts toward a terminally differentiated state. Hence, Medicago and related legumes have evolved a mechanism to dominate the symbiosis.}, }
@article {pmid16546131, year = {2006}, author = {Frossard, ML and Seabra, SH and DaMatta, RA and de Souza, W and de Mello, FG and Machado Motta, MC}, title = {An endosymbiont positively modulates ornithine decarboxylase in host trypanosomatids.}, journal = {Biochemical and biophysical research communications}, volume = {343}, number = {2}, pages = {443-449}, doi = {10.1016/j.bbrc.2006.02.168}, pmid = {16546131}, issn = {0006-291X}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Bacterial Proteins/*metabolism ; Crithidia/classification/*enzymology/*microbiology ; Enzyme Activation ; Ornithine Decarboxylase/*metabolism ; Species Specificity ; Symbiosis/*physiology ; }, abstract = {Some trypanosomatids, such as Crithidia deanei, are endosymbiont-containing species. Aposymbiotic strains are obtained after antibiotic treatment, revealing interesting aspects of this symbiotic association. Ornithine decarboxylase (ODC) promotes polyamine biosynthesis and contributes to cell proliferation. Here, we show that ODC activity is higher in endosymbiont-bearing trypanosomatids than in aposymbiotic cells, but isolated endosymbionts did not display this enzyme activity. Intriguingly, expressed levels of ODC were similar in both strains, suggesting that ODC is positively modulated in endosymbiont-bearing cells. When the aposymbiotic strain was grown in conditioned medium, obtained after cultivation of the endosymbiont-bearing strain, cellular proliferation as well as ODC activity and localization were similar to that observed in the endosymbiont-containing trypanosomatids. Furthermore, dialyzed-heated medium and trypsin treatment reduced ODC activity of the aposymbiont strain. Taken together, these data indicate that the endosymbiont can enhance the protozoan ODC activity by providing factors of protein nature, which increase the host polyamine metabolism.}, }
@article {pmid16542785, year = {2006}, author = {Apte, SP and Apte, PP}, title = {Antimicrobial drugs that target human--not microbial--genotypes or phenotypes: a paradigm change in human evolutionary response to pathogen selection pressure.}, journal = {Medical hypotheses}, volume = {67}, number = {2}, pages = {359-361}, doi = {10.1016/j.mehy.2006.01.043}, pmid = {16542785}, issn = {0306-9877}, mesh = {Anti-Infective Agents/*pharmacology ; Drug Resistance/*genetics ; *Evolution, Molecular ; Genome, Human/*drug effects/genetics ; Genotype ; Humans ; Phenotype ; *Selection, Genetic ; }, abstract = {Conventional antimicrobial drugs that target microbial life processes impose a selection pressure on pathogens and attenuate pathogen imposed selection pressure on human hosts. The simultaneous increase and decrease that result in pathogen and human host evolvability/adaptability, respectively, distorts the natural Darwinian evolutionary process. Such drugs may create an aberrant Darwinian genotype in human hosts that is ill prepared to resist emerging virulent pathogenic strains in the event of a decrease in host ontogenic potential. In contrast, antimicrobial drugs that target host human genes exert a selective pressure both on the human genome (without population decimation) as well as on pathogenic microbes. Such drugs maintain the evolvability/adaptability of the host in tandem with that of the pathogens in the context of Darwinian evolution. Such drugs retain the capacity of the human host to evolve genotypes that may confer resistance to future pathogenic microbial strains, to assimilate prokaryotic endosymbionts and to increase the probability of survival in the event of a decrease in host ontogenic potential.}, }
@article {pmid16536873, year = {2006}, author = {Wilson, AC and Dunbar, HE and Davis, GK and Hunter, WB and Stern, DL and Moran, NA}, title = {A dual-genome microarray for the pea aphid, Acyrthosiphon pisum, and its obligate bacterial symbiont, Buchnera aphidicola.}, journal = {BMC genomics}, volume = {7}, number = {}, pages = {50}, pmid = {16536873}, issn = {1471-2164}, support = {1R01GM63622-01/GM/NIGMS NIH HHS/United States ; 5F32GM069102-03/GM/NIGMS NIH HHS/United States ; K12 GM000708/GM/NIGMS NIH HHS/United States ; 1 K12 GM00708/GM/NIGMS NIH HHS/United States ; R01 GM063622/GM/NIGMS NIH HHS/United States ; F32 GM069102/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aphids/*genetics/metabolism/*microbiology ; Buchnera/*genetics/metabolism ; Expressed Sequence Tags ; Gene Expression Profiling/*methods ; *Gene Expression Regulation ; Genome, Insect ; Genomics ; Heat-Shock Response/genetics ; Oligonucleotide Array Sequence Analysis/*methods ; Symbiosis ; }, abstract = {BACKGROUND: The best studied insect-symbiont system is that of aphids and their primary bacterial endosymbiont Buchnera aphidicola. Buchnera inhabits specialized host cells called bacteriocytes, provides nutrients to the aphid and has co-speciated with its aphid hosts for the past 150 million years. We have used a single microarray to examine gene expression in the pea aphid, Acyrthosiphon pisum, and its resident Buchnera. Very little is known of gene expression in aphids, few studies have examined gene expression in Buchnera, and no study has examined simultaneously the expression profiles of a host and its symbiont. Expression profiling of aphids, in studies such as this, will be critical for assigning newly discovered A. pisum genes to functional roles. In particular, because aphids possess many genes that are absent from Drosophila and other holometabolous insect taxa, aphid genome annotation efforts cannot rely entirely on homology to the best-studied insect systems. Development of this dual-genome array represents a first attempt to characterize gene expression in this emerging model system.<br><br>RESULTS: We chose to examine heat shock response because it has been well characterized both in Buchnera and in other insect species. Our results from the Buchnera of A. pisum show responses for the same gene set as an earlier study of heat shock response in Buchnera for the host aphid Schizaphis graminum. Additionally, analyses of aphid transcripts showed the expected response for homologs of known heat shock genes as well as responses for several genes with unknown functional roles.<br><br>CONCLUSION: We examined gene expression under heat shock of an insect and its bacterial symbiont in a single assay using a dual-genome microarray. Further, our results indicate that microarrays are a useful tool for inferring functional roles of genes in A. pisum and other insects and suggest that the pea aphid genome may contain many gene paralogs that are differentially regulated.}, }
@article {pmid16533820, year = {2006}, author = {Shutt, TE and Gray, MW}, title = {Homologs of mitochondrial transcription factor B, sparsely distributed within the eukaryotic radiation, are likely derived from the dimethyladenosine methyltransferase of the mitochondrial endosymbiont.}, journal = {Molecular biology and evolution}, volume = {23}, number = {6}, pages = {1169-1179}, doi = {10.1093/molbev/msk001}, pmid = {16533820}, issn = {0737-4038}, mesh = {Acanthamoeba castellanii/genetics ; Alphaproteobacteria/genetics ; Amino Acid Sequence ; Animals ; DNA-Binding Proteins/genetics ; Dictyostelium/genetics ; Eukaryota/*genetics ; Eukaryotic Cells ; *Evolution, Molecular ; Hartmannella/genetics ; Humans ; Introns ; Mitochondria/*genetics ; Mitochondrial Proteins/*genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Homology, Nucleic Acid ; Symbiosis ; Transcription Factors/*genetics ; }, abstract = {Mitochondrial transcription factor B (mtTFB), an essential component in regulating the expression of mitochondrial DNA-encoded genes in both yeast and humans, is a dimethyladenosine methyltransferase (DMT) that has acquired a secondary role in mitochondrial transcription. So far, mtTFB has only been well studied in Opisthokonta (metazoan animals and fungi). Here we investigate the phylogenetic distribution of mtTFB homologs throughout the domain Eucarya, documenting the first examples of this protein outside of the opisthokonts. Surprisingly, we identified putative mtTFB homologs only in amoebozoan protists and trypanosomatids. Phylogenetic analysis together with conservation of intron positions in amoebozoan and human genes supports the grouping of the putative mtTFB homologs as a distinct clade. Phylogenetic analysis further demonstrates that the mtTFB is most likely derived from the DMT of the mitochondrial endosymbiont.}, }
@article {pmid16517650, year = {2006}, author = {Rinke, C and Schmitz-Esser, S and Stoecker, K and Nussbaumer, AD and Molnár, DA and Vanura, K and Wagner, M and Horn, M and Ott, JA and Bright, M}, title = {"Candidatus Thiobios zoothamnicoli," an ectosymbiotic bacterium covering the giant marine ciliate Zoothamnium niveum.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {3}, pages = {2014-2021}, pmid = {16517650}, issn = {0099-2240}, support = {P 16840/FWF_/Austrian Science Fund FWF/Austria ; }, mesh = {Animals ; Ciliophora/*microbiology ; DNA, Bacterial/analysis ; DNA, Ribosomal Spacer/analysis ; Gammaproteobacteria/*classification/genetics/ultrastructure ; Genes, rRNA ; In Situ Hybridization, Fluorescence ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Seawater/*parasitology ; Sequence Analysis, DNA ; Sulfides/metabolism ; *Symbiosis ; }, abstract = {Zoothamnium niveum is a giant, colonial marine ciliate from sulfide-rich habitats obligatorily covered with chemoautotrophic, sulfide-oxidizing bacteria which appear as coccoid rods and rods with a series of intermediate shapes. Comparative 16S rRNA gene sequence analysis and fluorescence in situ hybridization showed that the ectosymbiont of Z. niveum belongs to only one pleomorphic phylotype. The Z. niveum ectosymbiont is only moderately related to previously identified groups of thiotrophic symbionts within the Gammaproteobacteria, and shows highest 16S rRNA sequence similarity with the free-living sulfur-oxidizing bacterial strain ODIII6 from shallow-water hydrothermal vents of the Mediterranean Sea (94.5%) and an endosymbiont from a deep-sea hydrothermal vent gastropod of the Indian Ocean Ridge (93.1%). A replacement of this specific ectosymbiont by a variety of other bacteria was observed only for senescent basal parts of the host colonies. The taxonomic status "Candidatus Thiobios zoothamnicoli" is proposed for the ectosymbiont of Z. niveum based on its ultrastructure, its 16S rRNA gene, the intergenic spacer region, and its partial 23S rRNA gene sequence.}, }
@article {pmid16497674, year = {2006}, author = {Kanjilal-Kolar, S and Basu, SS and Kanipes, MI and Guan, Z and Garrett, TA and Raetz, CR}, title = {Expression cloning of three Rhizobium leguminosarum lipopolysaccharide core galacturonosyltransferases.}, journal = {The Journal of biological chemistry}, volume = {281}, number = {18}, pages = {12865-12878}, pmid = {16497674}, issn = {0021-9258}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; U54 GM069338/GM/NIGMS NIH HHS/United States ; R37-GM-51796/GM/NIGMS NIH HHS/United States ; R37 GM051796-10/GM/NIGMS NIH HHS/United States ; GM-069338/GM/NIGMS NIH HHS/United States ; }, mesh = {Carbohydrate Sequence ; Cloning, Molecular ; Cosmids/metabolism ; Escherichia coli/metabolism ; Glucuronosyltransferase/*chemistry/*genetics ; Hexuronic Acids/chemistry ; Lipopolysaccharides/*chemistry ; Models, Chemical ; Molecular Sequence Data ; Plasmids/metabolism ; Rhizobium leguminosarum/*genetics ; Species Specificity ; Substrate Specificity ; Sugar Acids/chemistry ; }, abstract = {The lipid A and core regions of the lipopolysaccharide in Rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, are strikingly different from those of Escherichia coli. In R. leguminosarum lipopolysaccharide, the inner core is modified with three galacturonic acid (GalA) moieties, two on the distal 3-deoxy-D-manno-octulosonic acid (Kdo) unit and one on the mannose residue. Here we describe the expression cloning of three novel GalA transferases from a 22-kb R. leguminosarum genomic DNA insert-containing cosmid (pSGAT). Two of these enzymes modify the substrate, Kdo2-[4'-(32)P]lipid IV(A) and its 1-dephosphorylated derivative on the distal Kdo residue, as indicated by mild acid hydrolysis. The third enzyme modifies the mannose unit of the substrate mannosyl-Kdo2-1-dephospho-[4'-(32)P]lipid IV(A). Sequencing of a 7-kb subclone derived from pSGAT revealed three putative membrane-bound glycosyltransferases, now designated RgtA, RgtB, and RgtC. Transfer by tri-parental mating of these genes into Sinorhizobium meliloti 1021, a strain that lacks these particular GalA residues, results in the heterologous expression of the GalA transferase activities seen in membranes of cells expressing pSGAT. Reconstitution experiments with the individual genes demonstrated that the activity of RgtA precedes and is necessary for the subsequent activity of RgtB, which is followed by the activity of RgtC. Electrospray ionization-tandem mass spectrometry and gas-liquid chromatography of the product generated in vitro by RgtA confirmed the presence of a GalA moiety. No in vitro activity was detected when RgtA was expressed in Escherichia coli unless Rhizobiaceae membranes were also included.}, }
@article {pmid16497220, year = {2006}, author = {Kessler, F and Schnell, DJ}, title = {The function and diversity of plastid protein import pathways: a multilane GTPase highway into plastids.}, journal = {Traffic (Copenhagen, Denmark)}, volume = {7}, number = {3}, pages = {248-257}, doi = {10.1111/j.1600-0854.2005.00382.x}, pmid = {16497220}, issn = {1398-9219}, support = {GM-61893/GM/NIGMS NIH HHS/United States ; }, mesh = {Forecasting ; GTP Phosphohydrolases/genetics/*physiology ; Intracellular Membranes/physiology ; Models, Biological ; Plant Proteins/genetics/*metabolism ; Plastids/metabolism/*physiology ; Protein Precursors/metabolism ; *Protein Transport ; }, abstract = {The photosynthetic chloroplast is the hallmark organelle of green plants. During the endosymbiotic evolution of chloroplasts, the vast majority of genes from the original cyanobacterial endosymbiont were transferred to the host cell nucleus. Chloroplast biogenesis therefore requires the import of nucleus-encoded proteins from their site of synthesis in the cytosol. The majority of proteins are imported by the activity of Toc and Tic complexes located within the chloroplast envelope. In addition to chloroplasts, plants have evolved additional, non-photosynthetic plastid types that are essential components of all cells. Recent studies indicate that the biogenesis of various plastid types relies on distinct but homologous Toc-Tic import pathways that have specialized in the import of specific classes of substrates. These different import pathways appear to be necessary to balance the essential physiological role of plastids in cellular metabolism with the demands of cellular differentiation and plant development.}, }
@article {pmid16495348, year = {2006}, author = {Robertson, DL and Tartar, A}, title = {Evolution of glutamine synthetase in heterokonts: evidence for endosymbiotic gene transfer and the early evolution of photosynthesis.}, journal = {Molecular biology and evolution}, volume = {23}, number = {5}, pages = {1048-1055}, doi = {10.1093/molbev/msj110}, pmid = {16495348}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Diatoms ; Evolution, Molecular ; *Genetics ; Glutamate-Ammonia Ligase/*genetics ; Lagenidium/genetics ; Molecular Sequence Data ; Oomycetes ; *Photosynthesis ; Phylogeny ; Protein Structure, Tertiary ; Rhodophyta/metabolism ; *Symbiosis ; }, abstract = {Although the endosymbiotic evolution of chloroplasts through primary and secondary associations is well established, the evolutionary timing and stability of the secondary endosymbiotic events is less well resolved. Heterokonts include both photosynthetic and nonphotosynthetic members and the nonphotosynthetic lineages branch basally in phylogenetic reconstructions. Molecular and morphological data indicate that heterokont chloroplasts evolved via a secondary endosymbiosis, involving a heterotrophic host cell and a photosynthetic ancestor of the red algae and this endosymbiotic event may have preceded the divergence of heterokonts and alveolates. If photosynthesis evolved early in this lineage, nuclear genomes of the nonphotosynthetic groups may contain genes that are not essential to photosynthesis but were derived from the endosymbiont genome through gene transfer. These genes offer the potential to trace the evolutionary history of chloroplast gains and losses within these lineages. Glutamine synthetase (GS) is essential for ammonium assimilation and glutamine biosynthesis in all organisms. Three paralogous gene families (GSI, GSII, and GSIII) have been identified and are broadly distributed among prokaryotic and eukaryotic lineages. In diatoms (Heterokonta), the nuclear-encoded chloroplast and cytosolic-localized GS isoforms are encoded by members of the GSII and GSIII family, respectively. Here, we explore the evolutionary history of GSII in both photosynthetic and nonphotosynthetic heterokonts, red algae, and other eukaryotes. GSII cDNA sequences were obtained from two species of oomycetes by polymerase chain reaction amplification. Additional GSII sequences from eukaryotes and bacteria were obtained from publicly available databases and genome projects. Bayesian inference and maximum likelihood phylogenetic analyses of GSII provided strong support for the monophyly of heterokonts, rhodophytes, chlorophytes, and plants and strong to moderate support for the Opisthokonts. Although the phylogeny is reflective of the unikont/bikont division of eukaryotes, we propose based on the robustness of the phylogenetic analyses that the heterokont GSII gene evolved via endosymbiotic gene transfer from the nucleus of the red-algal endosymbiont to the nucleus of the host. The lack of GSIII sequences in the oomycetes examined here further suggests that the GSIII gene that functions in the cytosol of photosynthetic heterokonts was replaced by the endosymbiont-derived GSII gene.}, }
@article {pmid16494962, year = {2006}, author = {Iyer, LM and Balaji, S and Koonin, EV and Aravind, L}, title = {Evolutionary genomics of nucleo-cytoplasmic large DNA viruses.}, journal = {Virus research}, volume = {117}, number = {1}, pages = {156-184}, doi = {10.1016/j.virusres.2006.01.009}, pmid = {16494962}, issn = {0168-1702}, support = {//Intramural NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Cell Nucleus/*virology ; Cytoplasm/*virology ; DNA Viruses/classification/*genetics ; Eukaryotic Cells/virology ; *Evolution, Molecular ; Genome, Viral ; *Genomics ; Humans ; Molecular Sequence Data ; Phylogeny ; Transcription Factors/chemistry/genetics ; Viral Proteins/chemistry/genetics ; }, abstract = {A previous comparative-genomic study of large nuclear and cytoplasmic DNA viruses (NCLDVs) of eukaryotes revealed the monophyletic origin of four viral families: poxviruses, asfarviruses, iridoviruses, and phycodnaviruses [Iyer, L.M., Aravind, L., Koonin, E.V., 2001. Common origin of four diverse families of large eukaryotic DNA viruses. J. Virol. 75 (23), 11720-11734]. Here we update this analysis by including the recently sequenced giant genome of the mimiviruses and several additional genomes of iridoviruses, phycodnaviruses, and poxviruses. The parsimonious reconstruction of the gene complement of the ancestral NCLDV shows that it was a complex virus with at least 41 genes that encoded the replication machinery, up to four RNA polymerase subunits, at least three transcription factors, capping and polyadenylation enzymes, the DNA packaging apparatus, and structural components of an icosahedral capsid and the viral membrane. The phylogeny of the NCLDVs is reconstructed by cladistic analysis of the viral gene complements, and it is shown that the two principal lineages of NCLDVs are comprised of poxviruses grouped with asfarviruses and iridoviruses grouped with phycodnaviruses-mimiviruses. The phycodna-mimivirus grouping was strongly supported by several derived shared characters, which seemed to rule out the previously suggested basal position of the mimivirus [Raoult, D., Audic, S., Robert, C., Abergel, C., Renesto, P., Ogata, H., La Scola, B., Suzan, M., Claverie, J.M. 2004. The 1.2-megabase genome sequence of Mimivirus. Science 306 (5700), 1344-1350]. These results indicate that the divergence of the major NCLDV families occurred at an early stage of evolution, prior to the divergence of the major eukaryotic lineages. It is shown that subsequent evolution of the NCLDV genomes involved lineage-specific expansion of paralogous gene families and acquisition of numerous genes via horizontal gene transfer from the eukaryotic hosts, other viruses, and bacteria (primarily, endosymbionts and parasites). Amongst the expansions, there are multiple families of predicted virus-specific signaling and regulatory domains. Most NCLDVs have also acquired large arrays of genes related to ubiquitin signaling, and the animal viruses in particular have independently evolved several defenses against apoptosis and immune response, including growth factors and potential inhibitors of cytokine signaling. The mimivirus displays an enormous array of genes of bacterial provenance, including a representative of a new class of predicted papain-like peptidases. It is further demonstrated that a significant number of genes found in NCLDVs also have homologs in bacteriophages, although a vertical relationship between the NCLDVs and a particular bacteriophage group could not be established. On the basis of these observations, two alternative scenarios for the origin of the NCLDVs and other groups of large DNA viruses of eukaryotes are considered. One of these scenarios posits an early assembly of an already large DNA virus precursor from which various large DNA viruses diverged through an ongoing process of displacement of the original genes by xenologous or non-orthologous genes from various sources. The second scenario posits convergent emergence, on multiple occasions, of large DNA viruses from small plasmid-like precursors through independent accretion of similar sets of genes due to strong selective pressures imposed by their life cycles and hosts.}, }
@article {pmid16490209, year = {2006}, author = {Patron, NJ and Waller, RF and Keeling, PJ}, title = {A tertiary plastid uses genes from two endosymbionts.}, journal = {Journal of molecular biology}, volume = {357}, number = {5}, pages = {1373-1382}, doi = {10.1016/j.jmb.2006.01.084}, pmid = {16490209}, issn = {0022-2836}, mesh = {Algal Proteins/classification/genetics ; Amino Acid Sequence ; Animals ; Biological Evolution ; Dinoflagellida/classification/*genetics/metabolism ; Eukaryota/genetics/metabolism ; Expressed Sequence Tags ; Molecular Sequence Data ; Peptides/classification/genetics ; Phylogeny ; Plastids/*genetics/metabolism ; Protein Isoforms/classification/genetics ; *Symbiosis ; }, abstract = {The origin and subsequent spread of plastids by endosymbiosis had a major environmental impact and altered the course of a great proportion of eukaryotic biodiversity. The ancestor of dinoflagellates contained a secondary plastid that was acquired in an ancient endosymbiotic event, where a eukaryotic cell engulfed a red alga. This is known as secondary endosymbiosis and has happened several times in eukaryotic evolution. Certain dinoflagellates, however, are unique in having replaced this secondary plastid in an additional (tertiary) round of endosymbiosis. Most plastid proteins are encoded in the nucleus of the host and are targeted to the organelle. When secondary or tertiary endosymbiosis takes place, it is thought that these genes move from nucleus to nucleus, so the plastid retains the same proteome. We have conducted large-scale expressed sequence tag (EST) surveys from Karlodinium micrum, a dinoflagellate with a tertiary haptophyte-derived plastid, and two haptophytes, Isochrysis galbana and Pavlova lutheri. We have identified all plastid-targeted proteins, analysed the phylogenetic origin of each protein, and compared their plastid-targeting transit peptides. Many plastid-targeted genes in the Karlodinium nucleus are indeed of haptophyte origin, but some genes were also retained from the original plastid (showing the two plastids likely co-existed in the same cell), in other cases multiple isoforms of different origins exist. We analysed plastid-targeting sequences and found the transit peptides in K.micrum are different from those found in either dinoflagellates or haptophytes, pointing to a plastid with an evolutionarily chimeric proteome, and a massive remodelling of protein trafficking during plastid replacement.}, }
@article {pmid16478052, year = {2005}, author = {Velázquez, E and Peix, A and Zurdo-Piñeiro, JL and Palomo, JL and Mateos, PF and Rivas, R and Muñoz-Adelantado, E and Toro, N and García-Benavides, P and Martínez-Molina, E}, title = {The coexistence of symbiosis and pathogenicity-determining genes in Rhizobium rhizogenes strains enables them to induce nodules and tumors or hairy roots in plants.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {18}, number = {12}, pages = {1325-1332}, doi = {10.1094/MPMI-18-1325}, pmid = {16478052}, issn = {0894-0282}, mesh = {Bacterial Proteins/*genetics/*metabolism ; Gene Expression Profiling ; Molecular Sequence Data ; Phaseolus/metabolism/microbiology ; Phylogeny ; Plant Roots/*microbiology ; Plasmids/genetics ; RNA, Ribosomal, 16S/genetics ; Rhizobium/classification/*genetics/*pathogenicity/physiology ; Symbiosis/*genetics ; Virulence/genetics ; }, abstract = {Bacteria belonging to the family Rhizobiaceae may establish beneficial or harmful relationships with plants. The legume endosymbionts contain nod and nif genes responsible for nodule formation and nitrogen fixation, respectively, whereas the pathogenic strains carry vir genes responsible for the formation of tumors or hairy roots. The symbiotic and pathogenic strains currently belong to different species of the genus Rhizobium and, until now, no strains able to establish symbiosis with legumes and also to induce tumors or hairy roots in plants have been reported. Here, we report for the first time the occurrence of two rhizobial strains (163C and ATCC11325T) belonging to Rhizobium rhizogenes able to induce hairy roots or tumors in plants and also to nodulate Phaseolus vulgaris under natural environmental conditions. Symbiotic plasmids (pSym) containing nod and nif genes and pTi- or pRi-type plasmids containing vir genes were found in these strains. The nodD and nifH genes of the strains from this study are phylogenetically related to those of Sinorhizobium strains nodulating P. vulgaris. The virA and virB4 genes from strain 163C are phylogenetically related to those of R. tumefaciens C58, whereas the same genes from strain ATCC 11325T are related to those of hairy root-inducing strains. These findings may be of high relevance for the better understanding of plant-microbe interactions and knowledge of rhizobial phylogenetic history.}, }
@article {pmid16476690, year = {2006}, author = {Klasson, L and Andersson, SG}, title = {Strong asymmetric mutation bias in endosymbiont genomes coincide with loss of genes for replication restart pathways.}, journal = {Molecular biology and evolution}, volume = {23}, number = {5}, pages = {1031-1039}, doi = {10.1093/molbev/msj107}, pmid = {16476690}, issn = {0737-4038}, mesh = {Buchnera/genetics ; Codon ; DNA/*genetics ; *DNA Replication ; Evolution, Molecular ; Gammaproteobacteria/genetics ; Genes, Bacterial ; Genetic Variation ; Genetics ; Genome ; Models, Genetic ; Models, Statistical ; *Mutation ; Sequence Analysis, DNA ; }, abstract = {A large majority of bacterial genomes show strand asymmetry, such that G and T preferentially accumulate on the leading strand. The mechanisms are unknown, but cytosine deaminations are thought to play an important role. Here, we have examined DNA strand asymmetry in three strains of the aphid endosymbiont Buchnera aphidicola. These are phylogenetically related, have similar genomic GC contents, and conserved gene order structures, yet B. aphidicola (Bp) shows a fourfold higher replication-induced strand bias than B. aphidicola (Sg) and (Ap). We rule out an increase in the overall substitution frequency as the major cause of the stronger strand bias in B. aphidicola (Bp). Instead, the results suggest that the higher GC skew in this species is caused by a different spectrum of mutations, including a relatively higher frequency of C to T mutations on the leading strand and/or of G to A mutations on the lagging strand. A comparative analysis of 20 gamma-proteobacterial genomes revealed that endosymbiont genomes lacking recA and other genes involved in replication restart processes, such as priA, which codes for primosomal helicase PriA, displayed the strongest strand bias. We hypothesize that cytosine deaminations accumulate during single-strand exposure at arrested replication forks and that inefficient restart mechanisms may lead to high DNA strand asymmetry in bacterial genomes.}, }
@article {pmid16474984, year = {2006}, author = {Field, SF and Bulina, MY and Kelmanson, IV and Bielawski, JP and Matz, MV}, title = {Adaptive evolution of multicolored fluorescent proteins in reef-building corals.}, journal = {Journal of molecular evolution}, volume = {62}, number = {3}, pages = {332-339}, pmid = {16474984}, issn = {0022-2844}, mesh = {Adaptation, Biological ; Animals ; Anthozoa/*chemistry/*genetics ; *Color ; *Evolution, Molecular ; Fluorescence ; Luminescent Proteins/*chemistry/*genetics ; Models, Molecular ; Mutation/genetics ; Phylogeny ; Protein Structure, Tertiary ; Selection, Genetic ; Time Factors ; }, abstract = {Here we investigate the evolutionary scenarios that led to the appearance of fluorescent color diversity in reef-building corals. We show that the mutations that have been responsible for the generation of new cyan and red phenotypes from the ancestral green were fixed with the help of positive natural selection. This fact strongly suggests that the color diversity is a product of adaptive evolution. An unexpected finding was a set of residues arranged as an intermolecular binding interface, which was also identified as a target of positive selection but is nevertheless not related to color diversification. We hypothesize that multicolored fluorescent proteins evolved as part of a mechanism regulating the relationships between the coral and its algal endosymbionts (zooxanthellae). We envision that the effect of the proteins' fluorescence on algal physiology may be achieved not only through photosynthesis modulation, but also through regulatory photosensors analogous to phytochromes and cryptochromes of higher plants. Such a regulation would require relatively subtle, but spectrally precise, modifications of the light field. Evolution of such a mechanism would explain both the adaptive diversification of colors and the coevolutionary chase at the putative algae-protein binding interface in coral fluorescent proteins.}, }
@article {pmid16472187, year = {2006}, author = {Pfarr, KM and Hoerauf, AM}, title = {Antibiotics which target the Wolbachia endosymbionts of filarial parasites: a new strategy for control of filariasis and amelioration of pathology.}, journal = {Mini reviews in medicinal chemistry}, volume = {6}, number = {2}, pages = {203-210}, doi = {10.2174/138955706775475984}, pmid = {16472187}, issn = {1389-5575}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Filariasis/*drug therapy ; Filarioidea/*microbiology/physiology ; Humans ; *Symbiosis ; Wolbachia/*drug effects ; }, abstract = {Wolbachia endosymbionts of filariae are targets for the development of new antifilarial chemotherapy. Doxycycline to deplete Wolbachia from the worm has demonstrated the feasibility of this strategy and has provided a new chemotherapeutic tool. Recent research shows that depleting Wolbachia will also lessen pathology, and lessen adverse reactions to traditional antifilarial drugs.}, }
@article {pmid16469053, year = {2006}, author = {Lapaque, N and Takeuchi, O and Corrales, F and Akira, S and Moriyon, I and Howard, JC and Gorvel, JP}, title = {Differential inductions of TNF-alpha and IGTP, IIGP by structurally diverse classic and non-classic lipopolysaccharides.}, journal = {Cellular microbiology}, volume = {8}, number = {3}, pages = {401-413}, doi = {10.1111/j.1462-5822.2005.00629.x}, pmid = {16469053}, issn = {1462-5814}, mesh = {Animals ; Female ; GTP Phosphohydrolases/*immunology/*metabolism ; Gram-Negative Bacteria/*immunology/metabolism ; Humans ; Lipid A/chemistry/immunology ; Lipopolysaccharides/*chemistry/*immunology ; Macrophages, Peritoneal/immunology/metabolism ; Mice ; Mice, Inbred C3H ; Mice, Inbred C57BL ; O Antigens/chemistry/immunology ; Tumor Necrosis Factor-alpha/*metabolism ; }, abstract = {The innate immune system recognizes microbes by characteristic molecules like the Gram-negative lipopolysaccharide (LPS). Lipid A (the LPS bioactive moiety) signals through toll-like receptors (TLRs) to induce pro-inflammatory molecules and small GTPases of the p47 family involved in intracellular pathogen control. We tested TNF-alpha and p47-GTPase induction in macrophages using classical LPSs [lipid As with glucosamine backbones, ester- and amide-linked C14:0(3-OH) and C12 to C16 in acyloxyacyl groups] of wild type and mutant Escherichia coli and Yersinia species and non-classical LPSs [lipid As with diaminoglucose, ester-linked 3-OH-fatty acids and C28:0(27-OH) and C23:0(29-OH) in acyloxyacyl groups] of plant endosymbionts (Rhizobium), intracellular pathogens (Brucella and Legionella) and phylogenetically related opportunistic bacteria (Ochrobactrum). Classical but not non-classical LPSs efficiently induced TNF-alpha, IIGP and IGTP p47-GTPase expression. Remarkably, the acyloxyacyl groups in classical LPSs necessary to efficiently induce TNF-alpha were not necessary to induce p47-GTPases, suggesting that different aspects of lipid A are involved in this differential induction. This was confirmed by using PPDM2, a non-endotoxic lipid A-structurally related synthetic glycolipid. Despite their different bioactivity, all types of LPSs signalled through TLR-4 and not through TLR-2. However, whereas TNF-alpha induction was myeloid differentiation factor 88 (MyD88)-dependent, that of p47-GTPases occurred via a MyD88-independent pathway. These observations show that different aspects of the LPS pathogen-associated molecular pattern may be triggering different signalling pathways linked to the same TLR. They also reinforce the hypothesis that non-classical lipid As act as virulence factors by favouring the escape from the innate immune system.}, }
@article {pmid16468995, year = {2006}, author = {MacLellan, SR and Zaheer, R and Sartor, AL and MacLean, AM and Finan, TM}, title = {Identification of a megaplasmid centromere reveals genetic structural diversity within the repABC family of basic replicons.}, journal = {Molecular microbiology}, volume = {59}, number = {5}, pages = {1559-1575}, doi = {10.1111/j.1365-2958.2006.05040.x}, pmid = {16468995}, issn = {0950-382X}, mesh = {Bacterial Proteins/genetics ; Base Sequence ; Binding Sites ; Centromere/*genetics ; DNA Helicases/genetics ; DNA-Binding Proteins/genetics ; Gene Expression Regulation, Bacterial ; *Genetic Variation ; Plasmids/*genetics ; Promoter Regions, Genetic ; Regulatory Sequences, Nucleic Acid ; Replicon/*genetics ; Sinorhizobium meliloti/*genetics ; Trans-Activators/genetics ; }, abstract = {The basic replication unit of many plasmids and second chromosomes in the alpha-proteobacteria consists of a repABC locus that encodes the trans- and cis-acting components required for both semiautonomous replication and replicon maintenance in a cell population. In terms of physical genetic organization and at the nucleotide sequence level, repABC loci are well conserved across various genera. As with all repABC-type replicons that have been genetically characterized, the 1.4 Mb pSymA and 1.7 Mb pSymB megaplasmids from the plant endosymbiont Sinorhizobium meliloti encode strong incompatibility (inc) determinants. We have identified a novel inc sequence upstream of the repA2 gene in pSymA that is not present on pSymB and not reported in other repABC plasmids that have been characterized. This region, in concert with the repA and repB genes, stabilizes a test plasmid indicating that it constitutes a partitioning (par) system for the megaplasmid. Purified RepB binds to this sequence and binding may be enhanced by RepA. We have isolated 19 point mutations that eliminate incompatibility, reduce RepB binding or the stabilization phenotype associated with this sequence and all of these map to a 16-nucleotide palindromic sequence centred 330 bp upstream of the repA2 gene. An additional five near-perfect repeats of this palindrome are located further upstream of the repA2 gene and we show that they share some conservation with known RepB binding sites in different locations on other repABC plasmids and to two sequences found on the tumour inducing plasmid of Agrobacterium tumefaciens. These additional palindromes also bind RepB but one of them does not display obvious incompatibility effects. A heterogenic distribution of par sequences demonstrates unexpected diversity in the structural genetic organization of repABC loci, despite their obvious levels of similarity.}, }
@article {pmid16461701, year = {2006}, author = {Marzorati, M and Alma, A and Sacchi, L and Pajoro, M and Palermo, S and Brusetti, L and Raddadi, N and Balloi, A and Tedeschi, R and Clementi, E and Corona, S and Quaglino, F and Bianco, PA and Beninati, T and Bandi, C and Daffonchio, D}, title = {A novel Bacteroidetes symbiont is localized in Scaphoideus titanus, the insect vector of Flavescence dorée in Vitis vinifera.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {2}, pages = {1467-1475}, pmid = {16461701}, issn = {0099-2240}, mesh = {Animals ; Bacteroidetes/genetics/*isolation &amp; purification/pathogenicity/ultrastructure ; Base Sequence ; DNA, Bacterial/genetics ; Fat Body/microbiology/ultrastructure ; Female ; Hemiptera/*microbiology/ultrastructure ; Insect Vectors/*microbiology/ultrastructure ; Male ; Microscopy, Electron ; Molecular Sequence Data ; Ovary/microbiology/ultrastructure ; Phylogeny ; Plant Diseases/*microbiology/*parasitology ; Salivary Glands/microbiology/ultrastructure ; Symbiosis ; Vitis/*microbiology/*parasitology ; }, abstract = {Flavescence dorée (FD) is a grapevine disease that afflicts several wine production areas in Europe, from Portugal to Serbia. FD is caused by a bacterium, "Candidatus Phytoplasma vitis," which is spread throughout the vineyards by a leafhopper, Scaphoideus titanus (Cicadellidae). After collection of S. titanus specimens from FD-contaminated vineyards in three different areas in the Piedmont region of Italy, we performed a survey to characterize the bacterial microflora associated with this insect. Using length heterogeneity PCR with universal primers for bacteria we identified a major peak associated with almost all of the individuals examined (both males and females). Characterization by denaturing gradient gel electrophoresis confirmed the presence of a major band that, after sequencing, showed a 97 to 99% identity with Bacteroidetes symbionts of the "Candidatus Cardinium hertigii" group. In addition, electron microscopy of tissues of S. titanus fed for 3 months on phytoplasma-infected grapevine plants showed bacterial cells with the typical morphology of "Ca. Cardinium hertigii." This endosymbiont, tentatively designated ST1-C, was found in the cytoplasm of previtellogenic and vitellogenic ovarian cells, in the follicle cells, and in the fat body and salivary glands. In addition, cell morphologies resembling those of "Ca. Phytoplasma vitis" were detected in the midgut, and specific PCR assays indicated the presence of the phytoplasma in the gut, fat body and salivary glands. These results indicate that ST1-C and "Ca. Phytoplasma vitis" have a complex life cycle in the body of S. titanus and are colocalized in different organs and tissues.}, }
@article {pmid16461691, year = {2006}, author = {Suzuki, Y and Kojima, S and Sasaki, T and Suzuki, M and Utsumi, T and Watanabe, H and Urakawa, H and Tsuchida, S and Nunoura, T and Hirayama, H and Takai, K and Nealson, KH and Horikoshi, K}, title = {Host-symbiont relationships in hydrothermal vent gastropods of the genus Alviniconcha from the Southwest Pacific.}, journal = {Applied and environmental microbiology}, volume = {72}, number = {2}, pages = {1388-1393}, pmid = {16461691}, issn = {0099-2240}, mesh = {Animals ; Carbon/metabolism ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Mitochondrial/genetics/isolation &amp; purification ; Electron Transport Complex IV/genetics ; Epsilonproteobacteria/classification/genetics/*isolation &amp; purification/metabolism ; Gammaproteobacteria/classification/genetics/*isolation &amp; purification/metabolism ; Gastropoda/classification/enzymology/genetics/*microbiology ; Molecular Sequence Data ; Pacific Ocean ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Hydrothermal vent gastropods of the genus Alviniconcha are unique among metazoans in their ability to derive their nutrition from chemoautotrophic gamma- and epsilon-proteobacterial endosymbionts. Although host-symbiont relationships in Alviniconcha gastropods from the Central Indian Ridge in the Indian Ocean and the Mariana Trough in the Western Pacific have been studied extensively, host-symbiont relationships in Alviniconcha gastropods from the Southwest Pacific remain largely unknown. Phylogenetic analysis using mitochondrial cytochrome c oxidase subunit I gene sequences of host gastropods from the Manus, North Fiji, and Lau Back-Arc Basins in the Southwest Pacific has revealed a new host lineage in a Alviniconcha gastropod from the Lau Basin and the occurrence of the host lineage Alviniconcha sp. type 2 in the Manus Basin. Based on 16S rRNA gene sequences of bacterial endosymbionts, two gamma-proteobacterial lineages and one epsilon-proteobacterial lineage were identified in the present study. The carbon isotopic compositions of the biomass and fatty acids of the gastropod tissues suggest that the gamma- and epsilon-proteobacterial endosymbionts mediate the Calvin-Benson cycle and the reductive tricarboxylic acid cycle, respectively, for their chemoautotrophic growth. Coupling of the host and symbiont lineages from the three Southwest Pacific basins revealed that each of the Alviniconcha lineages harbors different bacterial endosymbionts belonging to either the gamma- or epsilon-Proteobacteria. The host specificity exhibited in symbiont selection provides support for the recognition of each of the host lineages as a distinct species. The results from the present study also suggest the possibility that Alviniconcha sp. types 1 and 2 separately inhabit hydrothermal vent sites approximately 120 m apart in the North Fiji Basin and 500 m apart in the Manus Basin.}, }
@article {pmid16448417, year = {2006}, author = {Goodacre, SL and Martin, OY and Thomas, CF and Hewitt, GM}, title = {Wolbachia and other endosymbiont infections in spiders.}, journal = {Molecular ecology}, volume = {15}, number = {2}, pages = {517-527}, doi = {10.1111/j.1365-294X.2005.02802.x}, pmid = {16448417}, issn = {0962-1083}, mesh = {Animal Diseases/microbiology ; Animals ; Female ; Male ; Molecular Sequence Data ; *Phylogeny ; Rickettsia/genetics ; Spiders/*microbiology ; Spiroplasma/genetics ; Symbiosis ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Maternally inherited endosymbiotic bacteria, such as Wolbachia, Rickettsia and Spiroplasma, have been shown to have wide-ranging effects on the reproduction of their hosts. We present data on the presence of each of these sorts of bacteria in spiders, a group for which there are currently few data, but where such infections could explain many observed reproductive characteristics, such as sex ratio skew. The Wolbachia and Spiroplasma variants that we find in spiders belong to the same clades previously found to infect other arthropods, but many of the rickettsias belong to two, novel, hitherto spider-specific bacterial lineages. We find evidence for coexistence of different bacterial types within species, and in some cases, within individuals. We suggest that spiders present a useful opportunity for studying the effect of these sorts of bacteria on the evolution of host traits, such as those that are under sexual selection.}, }
@article {pmid16436059, year = {2006}, author = {Palmié-Peixoto, IV and Rocha, MR and Urbina, JA and de Souza, W and Einicker-Lamas, M and Motta, MC}, title = {Effects of sterol biosynthesis inhibitors on endosymbiont-bearing trypanosomatids.}, journal = {FEMS microbiology letters}, volume = {255}, number = {1}, pages = {33-42}, doi = {10.1111/j.1574-6968.2005.00056.x}, pmid = {16436059}, issn = {0378-1097}, mesh = {Animals ; Bacteria/chemistry/*drug effects ; Cholestanol/*analogs &amp; derivatives/pharmacology ; Enzyme Inhibitors/*pharmacology ; Sterols/*antagonists &amp; inhibitors/biosynthesis ; *Symbiosis ; Trypanosomatina/metabolism/*microbiology/ultrastructure ; }, abstract = {Some protozoa of the Trypanosomatidae family have a close relationship with an endosymbiotic bacterium. As the prokaryote envelope has a controversial origin, a sterol 24-methyltransferase inhibitor (20-piperidin-2-yl-5alpha-pregnan-3beta,20-diol; 22,26-azasterol) was used as a tool to investigate lipid biosynthetic pathways in Crithidia deanei, an endosymbiont-bearing trypanosomatid. Apart from antiproliferative effects, this drug induced ultrastructural alterations, consisting of myelin-like figures in the cytoplasm and endosymbiont envelope vesiculation. Concurrently, a dramatic reduction of 24-alkyl sterols was observed after 22,26-azasterol treatment, both in whole cell homogenates, as well as in isolated mitochondria. These effects were associated with changes of phospholipid composition, in particular a reduction of the phosphatidylcholine content and a concomitant increase in phosphatidylethanolamine levels. Lipid analyses of purified endosymbionts indicated a complete absence of sterols, and their phospholipid composition was different from that of mitochondria or whole protozoa, being similar to eubacteria closely associated with eukaryotes.}, }
@article {pmid16423015, year = {2006}, author = {Mrázek, J and Spormann, AM and Karlin, S}, title = {Genomic comparisons among gamma-proteobacteria.}, journal = {Environmental microbiology}, volume = {8}, number = {2}, pages = {273-288}, doi = {10.1111/j.1462-2920.2005.00894.x}, pmid = {16423015}, issn = {1462-2912}, mesh = {Bacterial Proteins/*genetics ; DNA, Bacterial/analysis ; Gammaproteobacteria/*genetics/metabolism ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; Multigene Family ; Predictive Value of Tests ; }, abstract = {Predicted highly expressed (PHX) genes are compared for 16 gamma-proteobacteria and their similarities and differences are interpreted with respect to known or predicted physiological characteristics of the organisms. Predicted highly expressed genes often reflect the organism's predominant lifestyle, habitat, nutrition sources and metabolic propensities. This technique allows to predict principal metabolic activities of the microorganisms operating in their natural habitats. Among our findings is an unusually high number of PHX enzymes acting in cell wall biosynthesis, amino acid biosynthesis and replication in the ant endosymbiont Blochmannia floridanus. We ascribe the abundance of these PHX genes to specific aspects of the relationship between the bacterium and its host. Xanthomonas campestris is unique with a very high number of PHX genes acting in flagellum biosynthesis, which may play a special role during its pathogenicity. Shewanella oneidensis possesses three protein complexes which all can function as complex I in the respiratory chain but only the Na(+)-transporting NADH:ubiquinone oxidoreductase nqr-2 operon is PHX. The PHX genes of Vibrio parahaemolyticus are consistent with the microorganism's adaptation to extremely fast growth rates. Comparative analysis of PHX genes from complex environmental genomic sequences as well as from uncultured pathogenic microbes can provide a novel, useful tool to predict global flux of matter and key intermediates.}, }
@article {pmid16419766, year = {2005}, author = {Lynn, DH and Strüder-Kypke, M}, title = {Scuticociliate endosymbionts of echinoids (phylum Echinodermata): phylogenetic relationships among species in the genera Entodiscus, Plagiopyliella, Thyrophylax, and Entorhipidium (phylum Ciliophora).}, journal = {The Journal of parasitology}, volume = {91}, number = {5}, pages = {1190-1199}, doi = {10.1645/GE-445R.1}, pmid = {16419766}, issn = {0022-3395}, mesh = {Animals ; Base Sequence ; Microscopy, Interference/veterinary ; Molecular Sequence Data ; Oligohymenophorea/*classification/genetics/ultrastructure ; *Phylogeny ; Polymerase Chain Reaction/veterinary ; RNA, Ribosomal/*chemistry ; Sequence Alignment/veterinary ; Strongylocentrotus/*parasitology ; *Symbiosis ; }, abstract = {Morphological research on over 50 species of ciliates recorded as endosymbionts of echinoids suggests that invasion of the echinoid microhabitat occurred on at least 4 occasions. Gene sequence data confirm the phylogenetic distinctness of spirotrichean, armophorean, plagiopylean, and oligohymenophorean endosymbionts. It is also likely that oligohymenophoreans have repeatedly invaded the gut habitat. To test this hypothesis, we sequenced small subunit rRNA (SSrRNA) genes of 6 species representing the larger scuticociliate species found in the intestine of Strongylocentrotus pallidus from the northeast Pacific Ocean: Entodiscus borealis (Entodiscidae); Plagiopyliella pacifica and Thyrophylax vorax (Thyrophylacidae); and Entorhipidium pilatum, Entorhipidium tenue, and Entorhipidium sp. (Entorhipidiidae). SsrRNA genes were amplified by PCR, and sequences obtained in both directions. In all phylogenetic analyses, the scuticociliates are well supported as a clade. Entodiscus is distinct from these other echinoid taxa and is the sister taxon to the facultatively parasitic Uronema marinum. The other 5 echinoid species always form a clade whose basal species is the free-living Parauronema longum. The greatest genetic distance among these latter 5 species is less than 1.5%. This probably explains why the Thyrophylacidae and Entorhipidiidae are paraphyletic based on the SSrRNA gene sequences.}, }
@article {pmid16417509, year = {2006}, author = {Mesa, S and Hennecke, H and Fischer, HM}, title = {A multitude of CRP/FNR-like transcription proteins in Bradyrhizobium japonicum.}, journal = {Biochemical Society transactions}, volume = {34}, number = {Pt 1}, pages = {156-159}, doi = {10.1042/BST0340156}, pmid = {16417509}, issn = {0300-5127}, mesh = {Bradyrhizobium/genetics/*metabolism ; DNA-Binding Proteins/classification/genetics/metabolism ; Gene Expression Regulation, Bacterial ; Iron-Sulfur Proteins/genetics/*metabolism ; Nitrogen/chemistry/metabolism ; Oxygen/metabolism ; Phylogeny ; Receptors, Cell Surface/genetics/*metabolism ; Transcription Factors/classification/genetics/*metabolism ; }, abstract = {In Bradyrhizobium japonicum, the nitrogen-fixing soya bean endosymbiont and facultative denitrifier, three CRP (cAMP receptor protein)/FNR (fumarate and nitrate reductase regulatory protein)-type transcription factors [FixK(1), FixK(2) and NnrR (nitrite and nitric oxide reductase regulator)] have been studied previously in the context of the regulation of nitrogen fixation and denitrification. The gene expression of both fixK(1) and nnrR depends on FixK(2), which acts as a key distributor of the 'low-oxygen' signal perceived by the two-component regulatory system FixLJ. While the targets for FixK(1) are not known, NnrR transduces the nitrogen oxide signal to the level of denitrification gene expression. Besides these three regulators, the complete genome sequence of this organism has revealed the existence of 13 additional CRP/FNR-type proteins whose functions have not yet been studied. Based on sequence similarity and phylogenetic analysis, we discuss in this paper the peculiarities of these additional factors.}, }
@article {pmid16415575, year = {2006}, author = {Halle, S}, title = {Polyphasic activity patterns in small mammals.}, journal = {Folia primatologica; international journal of primatology}, volume = {77}, number = {1-2}, pages = {15-26}, doi = {10.1159/000089693}, pmid = {16415575}, issn = {0015-5713}, mesh = {*Adaptation, Physiological ; Animals ; Arvicolinae/*physiology ; Behavior, Animal/*physiology ; Body Size ; Circadian Rhythm/*physiology ; Energy Metabolism/physiology ; *Environment ; Shrews/*physiology ; }, abstract = {Cathemeral species are routinely active during the day, the night and at twilight. For the majority of species it is advantageous to specialize on the environmental conditions of a particular phase of the 24-hour day, so this rather uncommon type of activity must be a consequence of specific constraints. Good examples are the polyphasic activity patterns found in some small mammals. In shrews, with small body size and extremely high metabolic rate, polyphasic activity represents a simple short-term hunger cycle. In voles the short-term rhythm is triggered by an additional endogenous ultradian clock that interacts with the common circadian system, which probably is functionally related to endosymbiont digestion of cellulose-rich food. The activity bouts of individuals are synchronized on the population level to spread predation risk. As cathemeral species, voles are not specifically adapted to particular light conditions, but they are also not restricted to a particular activity phase. Therefore, the benefits from flexible responses in activity timing to environmental challenges may compensate for the disadvantages of not being specialized.}, }
@article {pmid16413149, year = {2006}, author = {Gil, R and Sabater-Muñoz, B and Perez-Brocal, V and Silva, FJ and Latorre, A}, title = {Plasmids in the aphid endosymbiont Buchnera aphidicola with the smallest genomes. A puzzling evolutionary story.}, journal = {Gene}, volume = {370}, number = {}, pages = {17-25}, doi = {10.1016/j.gene.2005.10.043}, pmid = {16413149}, issn = {0378-1119}, mesh = {Amino Acids/biosynthesis/genetics ; Animals ; Aphids/physiology ; Buchnera/*genetics/metabolism ; *Evolution, Molecular ; Genome, Bacterial/*genetics ; Plasmids/*genetics/metabolism ; Rec A Recombinases/genetics ; Recombination, Genetic/*genetics ; Symbiosis/physiology ; }, abstract = {Buchnera aphidicola, the primary endosymbiont of aphids, has undergone important genomic and biochemical changes as an adaptation to intracellular life. The most important structural changes include a drastic genome reduction and the amplification of genes encoding key enzymes for the biosynthesis of amino acids by their translocation to plasmids. Molecular characterization through different aphid subfamilies has revealed that the genes involved in leucine and tryptophan biosynthesis show a variable fate, since they can be located on plasmids or on the chromosome in different lineages. This versatility contrasts with the genomic stasis found in three distantly related B. aphidicola strains already sequenced. We present the analysis of three B. aphidicola strains (BTg, BCt and BCc) belonging to aphids from different tribes of the subfamily Lachninae, that was estimated to harbour the bacteria with the smallest genomes. The presence of both leucine and tryptophan plasmids in BTg, a chimerical leucine-tryptophan plasmid in BCt, and only a leucine plasmid in BCc, indicates the existence of many recombination events in a recA minus bacterium. In addition, these B. aphidicola plasmids are the simplest described in this species, indicating that plasmids are also involved in the genome shrinkage process.}, }
@article {pmid16406301, year = {2006}, author = {Barbrook, AC and Howe, CJ and Purton, S}, title = {Why are plastid genomes retained in non-photosynthetic organisms?.}, journal = {Trends in plant science}, volume = {11}, number = {2}, pages = {101-108}, doi = {10.1016/j.tplants.2005.12.004}, pmid = {16406301}, issn = {1360-1385}, mesh = {Animals ; Apicomplexa/genetics/metabolism ; Genes, Plant ; Genes, rRNA ; *Genome ; Heme/biosynthesis ; Mitochondria/metabolism ; *Photosynthesis/genetics ; Plastids/*genetics ; Protein Biosynthesis ; RNA, Transfer/physiology ; RNA, Transfer, Glu/physiology ; RNA, Transfer, Met/physiology ; }, abstract = {The evolution of the plastid from a photosynthetic bacterial endosymbiont involved a dramatic reduction in the complexity of the plastid genome, with many genes either discarded or transferred to the nucleus of the eukaryotic host. However, this evolutionary process has not gone to completion and a subset of genes remains in all plastids examined to date. The various hypotheses put forward to explain the retention of the plastid genome have tended to focus on the need for photosynthetic organisms to retain a genetic system in the chloroplast, and they fail to explain why heterotrophic plants and algae, and the apicomplexan parasites all retain a genome in their non-photosynthetic plastids. Here we consider two additional explanations: the 'essential tRNAs' hypothesis and the 'transfer-window' hypothesis.}, }
@article {pmid16405591, year = {2006}, author = {Engelstädter, J and Hurst, GD}, title = {Can maternally transmitted endosymbionts facilitate the evolution of haplodiploidy?.}, journal = {Journal of evolutionary biology}, volume = {19}, number = {1}, pages = {194-202}, doi = {10.1111/j.1420-9101.2005.00974.x}, pmid = {16405591}, issn = {1010-061X}, mesh = {Animals ; *Biological Evolution ; Female ; Invertebrates/*genetics/*microbiology ; Male ; *Models, Biological ; *Ploidies ; Sex Ratio ; *Symbiosis ; Wolbachia/physiology ; }, abstract = {Whilst many invertebrate taxa are haplodiploid, the factors underlying the evolution of haplodiploidy remain unresolved. We investigate theoretically whether haplodiploidy might evolve as an outcome of the co-evolution between maternally inherited endosymbionts and their hosts. First, we substantially extend a recently developed model that involves maternally inherited endosymbionts that kill male offspring by eliminating the paternal genome. We also put forward a new hypothesis and develop a model that involves bacteria that induce cytoplasmic incompatibility (CI). Based on these models, we explore the co-evolutionary events that might occur between hosts and symbionts. We find that both with male-killers and CI-inducing endosymbionts, the hosts are likely to develop increased viability of haploid males, which can be considered a preadaptation to haplodiploidy. In addition, populations with haploidizing male-killers can in some cases evolve directly towards a genetic system of paternal genome elimination, a special form of haplodiploidy. These results are combined with consideration of mechanism and ecology to appraise the likelihood of male-killers and CI inducing bacteria being involved in the evolution of haplodiploidy.}, }
@article {pmid16401340, year = {2006}, author = {Gaudermann, P and Vogl, I and Zientz, E and Silva, FJ and Moya, A and Gross, R and Dandekar, T}, title = {Analysis of and function predictions for previously conserved hypothetical or putative proteins in Blochmannia floridanus.}, journal = {BMC microbiology}, volume = {6}, number = {}, pages = {1}, pmid = {16401340}, issn = {1471-2180}, mesh = {Animals ; Ants/microbiology ; Bacterial Proteins/chemistry/*genetics/*metabolism ; Enterobacteriaceae/genetics/*metabolism ; Gene Expression Profiling ; Genome, Bacterial ; Phylogeny ; Protein Conformation ; }, abstract = {BACKGROUND: There is an increasing interest to better understand endosymbiont capabilities in insects both from an ecological point of view and for pest control. Blochmannia floridanus provides important nutrients for its host, the ant Camponotus, while the bacterium in return is provided with a niche to proliferate. Blochmannia floridanus proteins and metabolites are difficult to study due to its endosymbiontic life style; however, its complete genome sequence became recently available.<br><br>RESULTS: Improved sequence analysis algorithms, databanks and gene and pathway context methods allowed us to reveal new information on various enzyme and pathways from the Blochmannia floridanus genome sequence [EMBL-ID BX248583]. Furthermore, these predictions are supported and linked to experimental data for instance from structural genomics projects (e.g. Bfl341, Bfl 499) or available biochemical data on proteins from other species which we show here to be related. We were able to assign a confirmed or at least a putative molecular function for 21 from 27 previously conserved hypothetical proteins. For 48 proteins of 66 with a previous putative assignment the function was further clarified. Several of these proteins occur in many proteobacteria and are found to be conserved even in the compact genome of this endosymbiont. To extend and re-test predictions and links to experimentally verified protein functions, functional clusters and interactions were assembled. These included septum initiation and cell division (Bfl165, Bfl303, Bfl248 et al.); translation; transport; the ubiquinone (Bfl547 et al.), the inositol and nitrogen pathways.<br><br>CONCLUSION: Taken together, our data allow a better and more complete description of the pathway capabilities and life style of this typical endosymbiont.}, }
@article {pmid16391072, year = {2006}, author = {Luyten, YA and Thompson, JR and Morrill, W and Polz, MF and Distel, DL}, title = {Extensive variation in intracellular symbiont community composition among members of a single population of the wood-boring bivalve Lyrodus pedicellatus (Bivalvia: Teredinidae).}, journal = {Applied and environmental microbiology}, volume = {72}, number = {1}, pages = {412-417}, pmid = {16391072}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/genetics/growth &amp; development/isolation &amp; purification ; Bivalvia/cytology/*microbiology ; Cloning, Molecular ; DNA Primers ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal/analysis/genetics ; *Ecosystem ; Electrophoresis, Capillary ; Gene Library ; *Genetic Variation ; Gills/microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Ribotyping ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Shipworms (wood-boring bivalves of the family Teredinidae) harbor in their gills intracellular bacterial symbionts thought to produce enzymes that enable the host to consume cellulose as its primary carbon source. Recently, it was demonstrated that multiple genetically distinct symbiont populations coexist within one shipworm species, Lyrodus pedicellatus. Here we explore the extent to which symbiont communities vary among individuals of this species by quantitatively examining the diversity, abundance, and pattern of occurrence of symbiont ribotypes (unique 16S rRNA sequence types) among specimens drawn from a single laboratory-reared population. A total of 18 ribotypes were identified in two clone libraries generated from gill tissue of (i) a single specimen and (ii) four pooled specimens. Phylogenetic analysis assigned all of the ribotypes to a unique clade within the gamma subgroup of proteobacteria which contained at least five well-supported internal clades (phylotypes). By competitive quantitative PCR and constant denaturant capillary electrophoresis, we estimated the number and abundance of symbiont phylotypes in gill samples of 13 individual shipworm specimens. Phylotype composition varied greatly; however, in all specimens the numerically dominant symbiont belonged to one of two nearly mutually exclusive phylotypes, each of which was detected with similar frequencies among specimens. A third phylotype, containing the culturable symbiont Teredinibacter turnerae, was identified in nearly all specimens, and two additional phylotypes were observed more sporadically. Such extensive variation in ribotype and phylotype composition among host specimens adds to a growing body of evidence that microbial endosymbiont populations may be both complex and dynamic and suggests that such genetic variation should be evaluated with regard to physiological and ecological differentiation.}, }
@article {pmid16380221, year = {2006}, author = {Zhou, T and Sun, X and Lu, Z}, title = {Synonymous codon usage in environmental chlamydia UWE25 reflects an evolutional divergence from pathogenic chlamydiae.}, journal = {Gene}, volume = {368}, number = {}, pages = {117-125}, doi = {10.1016/j.gene.2005.10.035}, pmid = {16380221}, issn = {0378-1119}, mesh = {Amino Acids/*genetics ; Base Composition ; Chlamydia trachomatis/*genetics ; Codon/*genetics ; DNA Replication ; DNA, Bacterial/chemistry/genetics ; *Evolution, Molecular ; *Genetic Variation ; *Genome, Bacterial ; Transcription, Genetic ; }, abstract = {Publication of the complete genome sequence for the Acanthamoeba sp. endosymbiont UWE25 has illuminated the evolution history of chlamydiae. In this study, the codon usage bias in UWE25 and five other species of pathogenic chlamydiae was calculated. It was found that genomic composition constraints are the major source of codon usage variation in UWE25. This result is different from the former observation in pathogenic chlamydiae, whose genomic base composition is more unbiased. Four other factors, such as strand-specific mutational bias, natural selection acting at the level of translation, hydropathy level of each protein and the conservation level of amino acids also have influence in shaping the codon usage in these six species to some extent. Further analysis suggests that the high stability of the UWE25 genome partially account for the difference in codon usage pattern between environmental and pathogenic chlamydiae. Moreover, our results imply that the replicational selection pressure in pathogenic chlamydiae is stronger than that in UWE25. Analyzing the codon usage pattern in the environmental chlamydia and comparing it with that of the pathogenic chlamydiae may provide clues how the chlamydiae have evolved from their common ancestor.}, }
@article {pmid16369937, year = {2006}, author = {Lester, L and Meade, A and Pagel, M}, title = {The slow road to the eukaryotic genome.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {28}, number = {1}, pages = {57-64}, doi = {10.1002/bies.20344}, pmid = {16369937}, issn = {0265-9247}, mesh = {Animals ; Eukaryotic Cells/*metabolism ; Evolution, Molecular ; Genome/*genetics ; Phylogeny ; Recombination, Genetic/genetics ; }, abstract = {The eukaryotic genome is a mosaic of eubacterial and archaeal genes in addition to those unique to itself. The mosaic may have arisen as the result of two prokaryotes merging their genomes, or from genes acquired from an endosymbiont of eubacterial origin. A third possibility is that the eukaryotic genome arose from successive events of lateral gene transfer over long periods of time. This theory does not exclude the endosymbiont, but questions whether it is necessary to explain the peculiar set of eukaryotic genes. We use phylogenetic studies and reconstructions of ancestral first appearances of genes on the prokaryotic phylogeny to assess evidence for the lateral gene transfer scenario. We find that phylogenies advanced to support fusion can also arise from a succession of lateral gene transfer events. Our reconstructions of ancestral first appearances of genes reveal that the various genes that make up the eukaryotic mosaic arose at different times and in diverse lineages on the prokaryotic tree, and were not available in a single lineage. Successive events of lateral gene transfer can explain the unusual mosaic structure of the eukaryotic genome, with its content linked to the immediate adaptive value of the genes its acquired. Progress in understanding eukaryotes may come from identifying ancestral features such as the eukaryotic splicesome that could explain why this lineage invaded, or created, the eukaryotic niche.}, }
@article {pmid16365377, year = {2006}, author = {Toh, H and Weiss, BL and Perkin, SA and Yamashita, A and Oshima, K and Hattori, M and Aksoy, S}, title = {Massive genome erosion and functional adaptations provide insights into the symbiotic lifestyle of Sodalis glossinidius in the tsetse host.}, journal = {Genome research}, volume = {16}, number = {2}, pages = {149-156}, pmid = {16365377}, issn = {1088-9051}, support = {R01 AI051584/AI/NIAID NIH HHS/United States ; R01 GM069449/GM/NIGMS NIH HHS/United States ; AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Adaptation, Physiological/*genetics ; Animals ; Base Sequence ; Enterobacteriaceae/*genetics ; *Evolution, Molecular ; Genes, Bacterial/*genetics ; Molecular Sequence Data ; Symbiosis/*genetics ; Tsetse Flies/*microbiology ; }, abstract = {Sodalis glossinidius is a maternally transmitted endosymbiont of tsetse flies (Glossina spp.), an insect of medical and veterinary significance. Analysis of the complete sequence of Sodalis' chromosome (4,171,146 bp, encoding 2,432 protein coding sequences) indicates a reduced coding capacity of 51%. Furthermore, the chromosome contains 972 pseudogenes, an inordinately high number compared with that of other bacterial species. A high proportion of these pseudogenes are homologs of known proteins that function either in defense or in the transport and metabolism of carbohydrates and inorganic ions, suggesting Sodalis' degenerative adaptations to the immunity and restricted nutritional status of the host. Sodalis possesses three chromosomal symbiosis regions (SSR): SSR-1, SSR-2, and SSR-3, with gene inventories similar to the Type-III secretion system (TTSS) ysa from Yersinia enterolitica and SPI-1 and SPI-2 from Salmonella, respectively. While core components of the needle structure have been conserved, some of the effectors and regulators typically associated with these systems in pathogenic microbes are modified or eliminated in Sodalis. Analysis of SSR-specific invA transcript abundance in Sodalis during host development indicates that the individual symbiosis regions may exhibit different temporal expression profiles. In addition, the Sodalis chromosome encodes a complete flagella structure, key components of which are expressed in immature host developmental stages. These features may be important for the transmission and establishment of symbiont infections in the intra-uterine progeny. The data suggest that Sodalis represents an evolutionary intermediate transitioning from a free-living to a mutualistic lifestyle.}, }
@article {pmid16364493, year = {2006}, author = {Shutt, TE and Gray, MW}, title = {Bacteriophage origins of mitochondrial replication and transcription proteins.}, journal = {Trends in genetics : TIG}, volume = {22}, number = {2}, pages = {90-95}, doi = {10.1016/j.tig.2005.11.007}, pmid = {16364493}, issn = {0168-9525}, mesh = {Bacteriophage T7/*genetics ; DNA Replication ; DNA, Mitochondrial/*genetics ; DNA-Directed RNA Polymerases ; Mitochondria/*metabolism ; Replication Origin ; *Transcription, Genetic ; }, abstract = {Mounting evidence suggests that key components of the mitochondrial transcription and replication apparatus are derived from the T-odd lineage of bacteriophage rather than from an alpha-Proteobacterium, as the endosymbiont hypothesis would predict. We propose that several mitochondrial replication genes were acquired together from an ancestor of T-odd phage early in the evolution of the eukaryotic cell, at the time of the mitochondrial endosymbiosis. We further propose that at a later stage the single-subunit RNA polymerase, originally acquired for mitochondrial DNA replication, was co-opted to serve in mitochondrial transcription.}, }
@article {pmid16360953, year = {2006}, author = {Sanogo, YO and Dobson, SL}, title = {WO bacteriophage transcription in Wolbachia-infected Culex pipiens.}, journal = {Insect biochemistry and molecular biology}, volume = {36}, number = {1}, pages = {80-85}, doi = {10.1016/j.ibmb.2005.11.001}, pmid = {16360953}, issn = {0965-1748}, support = {AI-51533/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteriophages/*genetics ; Culex/classification/*microbiology ; DNA, Viral ; Female ; *Gene Expression Regulation, Viral ; Genetic Variation ; Life Cycle Stages ; Male ; RNA, Viral ; Sex Factors ; Transcription, Genetic ; Wolbachia/*virology ; }, abstract = {Bacteriophages are commonly found in association with free-living bacteria, both as exogenic phages (virions) and as prophages integrated into the bacterial genome. In contrast, the observation of bacteriophages associated with obligate intracellular bacteria has been described infrequently. An exception is provided by Wolbachia endosymbionts, which harbor multiple phage elements that have been designated as WO phage. Wolbachia are maternally inherited bacteria that occur in the cytoplasm of many invertebrates, where they often manipulate host reproduction. Previously, the WO phage orf7 locus and ankyrin repeat-encoding genes have been observed to represent sources of genetic diversity between Wolbachia (wPip) strains infecting mosquitoes of the Culex pipiens complex and have been suggested as potential participants in the reproductive manipulations. We have characterized WO phage associated with multiple Wolbachia-infected Culex strains and an uninfected strain using electron microscopy and RT-PCR. For each strain, different developmental stages were examined for transcription of three WO phage orf7 genes. The results provide evidence for the presence of both actively transcribed virions and inactive prophages. Variable orf7 transcription patterns are observed in comparisons of differing Cx. pipiens strains. Variability includes both mosquito stage-specific and sexually dimorphic orf7 expression patterns. This report provides additional support for the hypothesis that bacteriophages play an important role in Wolbachia and host evolution.}, }
@article {pmid16357252, year = {2005}, author = {Scarborough, CL and Ferrari, J and Godfray, HC}, title = {Aphid protected from pathogen by endosymbiont.}, journal = {Science (New York, N.Y.)}, volume = {310}, number = {5755}, pages = {1781}, doi = {10.1126/science.1120180}, pmid = {16357252}, issn = {1095-9203}, support = {D19263/BB_/Biotechnology and Biological Sciences Research Council/United Kingdom ; }, mesh = {Animals ; Aphids/*microbiology/physiology ; Enterobacteriaceae/genetics/*physiology ; Entomophthorales/pathogenicity/*physiology ; Molecular Sequence Data ; Spores, Fungal/physiology ; *Symbiosis ; }, abstract = {Aphids are associated with several facultative bacterial endosymbionts that may influence their interactions with other organisms. We show here that one of the three most common facultative symbionts of pea aphid (Acyrthosiphon pisum), the bacterium Regiella insecticola, has a major effect on host resistance to a fungal pathogen. Experimental establishment of the bacterium in uninfected aphid clones led to higher survival after fungal attack. The bacteria also increased the aphid's inclusive fitness, because the presence of the symbiont reduced the probability of fungal sporulation on aphid cadavers, hence lowering the rate of transmission of the disease to nearby related aphids.}, }
@article {pmid16357039, year = {2006}, author = {Li, S and Nosenko, T and Hackett, JD and Bhattacharya, D}, title = {Phylogenomic analysis identifies red algal genes of endosymbiotic origin in the chromalveolates.}, journal = {Molecular biology and evolution}, volume = {23}, number = {3}, pages = {663-674}, doi = {10.1093/molbev/msj075}, pmid = {16357039}, issn = {0737-4038}, support = {T 32 GM98629/GM/NIGMS NIH HHS/United States ; }, mesh = {Algal Proteins/genetics ; Animals ; *Gene Transfer, Horizontal ; Genes, Plant ; Molecular Sequence Data ; *Phylogeny ; Plant Proteins/genetics ; Plastids/chemistry ; *Rhodophyta/classification/genetics ; *Symbiosis ; Thylakoids/chemistry ; }, abstract = {Endosymbiosis has spread photosynthesis to many branches of the eukaryotic tree; however, the history of photosynthetic organelle (plastid) gain and loss remains controversial. Fortuitously, endosymbiosis may leave a genomic footprint through the transfer of endosymbiont genes to the "host" nucleus (endosymbiotic gene transfer, EGT). EGT can be detected through comparison of host genomes to uncover the history of past plastid acquisitions. Here we focus on a lineage of chlorophyll c-containing algae and protists ("chromalveolates") that are postulated to share a common red algal secondary endosymbiont. This plastid is originally of cyanobacterial origin through primary endosymbiosis and is closely related among the Plantae (i.e., red, green, and glaucophyte algae). To test these ideas, an automated phylogenomics pipeline was used with a novel unigene data set of 5,081 expressed sequence tags (ESTs) from the haptophyte alga Emiliania huxleyi and genome or EST data from other chromalveolates, red algae, plants, animals, fungi, and bacteria. We focused on nuclear-encoded proteins that are targeted to the plastid to express their function because this group of genes is expected to have phylogenies that are relatively easy to interpret. A total of 708 genes were identified in E. huxleyi that had a significant Blast hit to at least one other taxon in our data set. Forty-six of the alignments that were derived from the 708 genes contained at least one other chromalveolate (i.e., besides E. huxleyi), red and/or green algae (or land plants), and one or more cyanobacteria, whereas 15 alignments contained E. huxleyi, one or more other chromalveolates, and only cyanobacteria. Detailed phylogenetic analyses of these data sets turned up 19 cases of EGT that did not contain significant paralogy and had strong bootstrap support at the internal nodes, allowing us to confidently identify the source of the plastid-targeted gene in E. huxleyi. A total of 17 genes originated from the red algal lineage, whereas 2 genes were of green algal origin. Our data demonstrate the existence of multiple red algal genes that are shared among different chromalveolates, suggesting that at least a subset of this group may share a common origin.}, }
@article {pmid16349492, year = {1998}, author = {Pond, DW and Bell, MV and Dixon, DR and Fallick, AE and Segonzac, M and Sargent, JR}, title = {Stable-carbon-isotope composition of Fatty acids in hydrothermal vent mussels containing methanotrophic and thiotrophic bacterial endosymbionts.}, journal = {Applied and environmental microbiology}, volume = {64}, number = {1}, pages = {370-375}, pmid = {16349492}, issn = {0099-2240}, abstract = {Fatty acid biomarker analysis coupled with gas chromatography-isotope ratio mass spectrometry was used to confirm the presence of methanotrophic and thiotrophic bacterial endosymbionts in the tissues of a hydrothermal vent mussel (Bathymodiolus sp.), collected from the Menez Gwen vent field on the mid-Atlantic ridge. Monounsaturated (n-8) fatty acids, which are diagnostic of methanotrophic bacteria, were detected in all three types of tissues examined (gill, posterior adductor, and mantle), although levels were highest in gill tissues where the bacteria were found. Stable-carbon-isotope compositions (delta-C per mille relative to that of Peedee belemnite) of fatty acids for all three tissues ranged from -24.9 to -34.9 per thousand, which encompasses the range predicted for both thiotroph- and methanotroph-based nutrition. The data suggest that these thio- and methanotrophic bacterial endosymbionts are equally important in the nutrition of the vent mussel at this particular vent site.}, }
@article {pmid16343316, year = {2006}, author = {Artursson, V and Finlay, RD and Jansson, JK}, title = {Interactions between arbuscular mycorrhizal fungi and bacteria and their potential for stimulating plant growth.}, journal = {Environmental microbiology}, volume = {8}, number = {1}, pages = {1-10}, doi = {10.1111/j.1462-2920.2005.00942.x}, pmid = {16343316}, issn = {1462-2912}, mesh = {*Bacterial Physiological Phenomena ; Biological Availability ; Crops, Agricultural/*growth &amp; development/*microbiology ; *Models, Biological ; Mycorrhizae/*physiology ; Nitrogen/pharmacokinetics ; Phosphorus/pharmacokinetics ; Plant Roots/*microbiology ; *Symbiosis ; }, abstract = {Arbuscular mycorrhizal (AM) fungi and bacteria can interact synergistically to stimulate plant growth through a range of mechanisms that include improved nutrient acquisition and inhibition of fungal plant pathogens. These interactions may be of crucial importance within sustainable, low-input agricultural cropping systems that rely on biological processes rather than agrochemicals to maintain soil fertility and plant health. Although there are many studies concerning interactions between AM fungi and bacteria, the underlying mechanisms behind these associations are in general not very well understood, and their functional properties still require further experimental confirmation. Future mycorrhizal research should therefore strive towards an improved understanding of the functional mechanisms behind such microbial interactions, so that optimized combinations of microorganisms can be applied as effective inoculants within sustainable crop production systems. In this context, the present article seeks to review and discuss the current knowledge concerning interactions between AM fungi and plant growth-promoting rhizobacteria, the physical interactions between AM fungi and bacteria, enhancement of phosphorus and nitrogen bioavailability through such interactions, and finally the associations between AM fungi and their bacterial endosymbionts. Overall, this review summarizes what is known to date within the present field, and attempts to identify promising lines of future research.}, }
@article {pmid16342786, year = {2005}, author = {Chu, D and Zhang, YJ and Bi, YP and Fu, HB}, title = {[Wolbachia endosymbionts and their effects on the fitness of the arthropod hosts].}, journal = {Wei sheng wu xue bao = Acta microbiologica Sinica}, volume = {45}, number = {5}, pages = {817-820}, pmid = {16342786}, issn = {0001-6209}, mesh = {Animals ; Arthropods/*microbiology/physiology ; Ecology ; Reproduction ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia are common and maternally inherited bacteria found in reproductive tissue of a wide range of arthropod species. A tremendous amount of progress on their manipulating reproduction of their host has been made over the past 30 years. Recent surveys have found that they could effect the fitness of their hosts. The recent advances on Wolbachia distribution, locality and their effects on the fitness of hosts are reviewed, and the significance and potential implications of the fields are discussed.}, }
@article {pmid16332877, year = {2005}, author = {Noda, S and Iida, T and Kitade, O and Nakajima, H and Kudo, T and Ohkuma, M}, title = {Endosymbiotic Bacteroidales bacteria of the flagellated protist Pseudotrichonympha grassii in the gut of the termite Coptotermes formosanus.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {12}, pages = {8811-8817}, pmid = {16332877}, issn = {0099-2240}, mesh = {Animals ; Bacteroidaceae/classification/genetics/isolation &amp; purification/*physiology ; Base Sequence ; Digestive System/*microbiology ; Flagella/*ultrastructure ; Isoptera/*microbiology/physiology ; Phylogeny ; Polymerase Chain Reaction/methods ; Polymorphism, Restriction Fragment Length ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {A unique lineage of bacteria belonging to the order Bacteroidales was identified as an intracellular endosymbiont of the protist Pseudotrichonympha grassii (Parabasalia, Hypermastigea) in the gut of the termite Coptotermes formosanus. We identified the 16S rRNA, gyrB, elongation factor Tu, and groEL gene sequences in the endosymbiont and detected a very low level of sequence divergence (<0.9% of the nucleotides) in the endosymbiont population within and among protist cells. The Bacteroidales endosymbiont sequence was affiliated with a cluster comprising only sequences from termite gut bacteria and was not closely related to sequences identified for members of the Bacteroidales attached to the cell surfaces of other gut protists. Transmission electron microscopy showed that there were numerous rod-shaped bacteria in the cytoplasm of the host protist, and we detected the endosymbiont by fluorescence in situ hybridization (FISH) with an oligonucleotide probe specific for the 16S rRNA gene identified. Quantification of the abundance of the Bacteroidales endosymbiont by sequence-specific cleavage of rRNA with RNase H and FISH cell counting revealed, surprisingly, that the endosymbiont accounted for 82% of the total bacterial rRNA and 71% of the total bacterial cells in the gut community. The genetically nearly homogeneous endosymbionts of Pseudotrichonympha were very abundant in the gut symbiotic community of the termite.}, }
@article {pmid16332784, year = {2005}, author = {Bontemps, C and Golfier, G and Gris-Liebe, C and Carrere, S and Talini, L and Boivin-Masson, C}, title = {Microarray-based detection and typing of the Rhizobium nodulation gene nodC: potential of DNA arrays to diagnose biological functions of interest.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {12}, pages = {8042-8048}, pmid = {16332784}, issn = {0099-2240}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics ; Bacterial Typing Techniques ; Base Sequence ; DNA Primers ; DNA, Bacterial/*genetics ; Molecular Sequence Data ; Multigene Family ; N-Acetylglucosaminyltransferases/*genetics ; Oligonucleotide Array Sequence Analysis ; Phylogeny ; Rhizobium/classification/enzymology/*genetics ; }, abstract = {Environmental screening of bacteria for the presence of genes of interest is a challenging problem, due to the high variability of the nucleotide sequence of a given gene between species. Here, we tackle this general issue using a particularly well-suited model system that consists of the nodulation gene nodC, which is shared by phylogenetically distant rhizobia. 41mer and 50mer oligonucleotides featuring the nucleotide diversity of two highly conserved regions of the NodC protein were spotted on glass slides and cross hybridized with the radioactive-labeled target genomic DNA under low-stringency conditions. Statistical analysis of the hybridization patterns allowed the detection of known, as well as new, nodC sequences and classified the rhizobial strains accordingly. The microarray was successfully used to type the nodC gene directly from legume nodules, thus eliminating the need of cultivation of the endosymbiont. This approach could be extended to a panel of diagnostic genes and constitute a powerful tool for studying the distribution of genes of interest in the environment, as well as for bacteria identification.}, }
@article {pmid16329896, year = {2005}, author = {Schwarz, MV and Frenzel, P}, title = {Methanogenic symbionts of anaerobic ciliates and their contribution to methanogenesis in an anoxic rice field soil.}, journal = {FEMS microbiology ecology}, volume = {52}, number = {1}, pages = {93-99}, doi = {10.1016/j.femsec.2004.10.009}, pmid = {16329896}, issn = {0168-6496}, mesh = {Animals ; Bacteria, Anaerobic/drug effects/*metabolism ; Ciliophora/drug effects/*microbiology/physiology ; Colchicine/toxicity ; Cycloheximide/toxicity ; Methane/*metabolism ; *Oryza ; Population Dynamics ; *Soil Microbiology ; *Symbiosis ; Time Factors ; }, abstract = {Methanogenesis in rice field soils starts soon after flooding while potentially competing processes like reduction of sulphate and iron take place. Early methanogenesis is mainly driven by hydrogen, while later in the season acetate tends to become more important. Anaerobic ciliates are abundant during this period, and their endosymbionts use hydrogen produced by the ciliates to reduce carbon dioxide to methane. These endosymbiotic methanogens are protected from the competition for substrates with other bacteria that may control methanogenesis outside the protozoan cells. Thus, we focussed on early methanogenesis and on the potential contribution from ciliates and their endosymbionts. Only ciliates of the genus Metopus were found to harbour methanogens, as identified by the F(420)-fluorescence of the endosymbionts. We followed the population dynamics of the ciliates with time, and calculated the ratio of symbiotic methane production to overall methanogenesis. Symbiotic methane production was calculated from the species-specific numbers of methanogenic endosymbionts times the cell-specific methane production of the symbionts. According to this calculation, the symbionts' contribution to overall methane production was only 6.4% at the beginning and decreased with time. In a second experiment, colchicine and cycloheximide were used to inhibit all eukaryotes, comparing the remaining methane production rate to a control without inhibitors. In the inhibition experiment, the contribution from symbionts decreased from 40% to 6% during the first days after flooding, and dropped to near zero within 2 weeks. However, nearly all methane produced from H(2)/CO(2) could be attributed to the ciliates' symbionts between days 5 and 10 after flooding. Both experiments showed that the contribution of methanogenic symbionts to overall methane production is a transient phenomenon, restricted to the first 2 weeks.}, }
@article {pmid16313611, year = {2005}, author = {Gentle, IE and Burri, L and Lithgow, T}, title = {Molecular architecture and function of the Omp85 family of proteins.}, journal = {Molecular microbiology}, volume = {58}, number = {5}, pages = {1216-1225}, doi = {10.1111/j.1365-2958.2005.04906.x}, pmid = {16313611}, issn = {0950-382X}, mesh = {*Bacterial Outer Membrane Proteins/chemistry/genetics/metabolism ; Cell Membrane/*metabolism ; Gram-Negative Bacteria/chemistry/genetics/*metabolism ; }, abstract = {Omp85 is a protein found in Gram-negative bacteria where it serves to integrate proteins into the bacterial outer membrane. Members of the Omp85 family of proteins are defined by the presence of two domains: an N-terminal, periplasmic domain rich in POTRA repeats and a C-terminal beta-barrel domain embedded in the outer membrane. The widespread distribution of Omp85 family members together with their fundamental role in outer membrane assembly suggests the ancestral Omp85 arose early in the evolution of prokaryotic cells. Mitochondria, derived from an ancestral bacterial endosymbiont, also use a member of the Omp85 family to assemble proteins in their outer membranes. More distant relationships are seen between the Omp85 family and both the core proteins in two-partner secretion systems and the Toc75 family of protein translocases found in plastid outer envelopes. Aspects of the ancestry and molecular architecture of the Omp85 family of proteins is providing insight into the mechanism by which proteins might be integrated and assembled into bacterial outer membranes.}, }
@article {pmid16306383, year = {2006}, author = {Lane, CE and Khan, H and MacKinnon, M and Fong, A and Theophilou, S and Archibald, JM and , }, title = {Proceedings of the SMBE Tri-National Young Investigators' Workshop 2005. Insight into the diversity and evolution of the cryptomonad nucleomorph genome.}, journal = {Molecular biology and evolution}, volume = {23}, number = {5}, pages = {856-865}, doi = {10.1093/molbev/msj066}, pmid = {16306383}, issn = {0737-4038}, mesh = {Bayes Theorem ; Biological Evolution ; Blotting, Southern ; Cloning, Molecular ; Conserved Sequence ; Cryptophyta/*genetics ; DNA, Ribosomal/genetics ; Eukaryota/*genetics ; Evolution, Molecular ; Genetic Variation ; *Genome ; HSP90 Heat-Shock Proteins/genetics ; Phylogeny ; Polymerase Chain Reaction ; }, abstract = {The cryptomonads are an enigmatic group of marine and freshwater unicellular algae that acquired their plastids through the engulfment and retention of a eukaryotic ("secondary") endosymbiont. Together with the chlorarachniophyte algae, the cryptomonads are unusual in that they have retained the nucleus of their endosymbiont in a miniaturized form called a nucleomorph. The nucleomorph genome of the cryptomonad Guillardia theta has been completely sequenced and with only three chromosomes and a total size of 551 kb, is a model of nuclear genome compaction. Using this genome as a reference, we have investigated the structure and content of nucleomorph genomes in a wide range of cryptomonad algae. In this study, we have sequenced nine new cryptomonad nucleomorph 18S ribosomal DNA (rDNA) genes and four heat shock protein 90 (hsp90) gene fragments, and using pulsed-field gel electrophoresis and Southern hybridizations, have obtained nucleomorph genome size estimates for nine different species. We also used long-range polymerase chain reaction to obtain nucleomorph genomic fragments from Hanusia phi CCMP325 and Proteomonas sulcata CCMP704 that are syntenic with the subtelomeric region of nucleomorph chromosome I in G. theta. Our results indicate that (1) the presence of three chromosomes is a common feature of the nucleomorph genomes of these organisms, (2) nucleomorph genome size varies dramatically in the cryptomonads examined, (3) unidentified cryptomonad species CCMP1178 has the largest nucleomorph genome identified to date at approximately 845 kb, (4) nucleomorph genome size reductions appear to have occurred multiple times independently during cryptomonad evolution, (5) the relative positions of the 18S rDNA, ubc4, and hsp90 genes are conserved in three different cryptomonad genera, and (6) interchromosomal recombination appears to be rapidly changing the size and sequence of a repetitive subtelomeric region of the nucleomorph genome between the 18S rDNA and ubc4 loci. These results provide a glimpse into the genetic diversity of nucleomorph genomes in cryptomonads and set the stage for more comprehensive sequence-based studies in closely and distantly related taxa.}, }
@article {pmid16306142, year = {2005}, author = {Charron, JB and Ouellet, F and Pelletier, M and Danyluk, J and Chauve, C and Sarhan, F}, title = {Identification, expression, and evolutionary analyses of plant lipocalins.}, journal = {Plant physiology}, volume = {139}, number = {4}, pages = {2017-2028}, pmid = {16306142}, issn = {0032-0889}, mesh = {Amino Acid Sequence ; Circadian Rhythm ; Evolution, Molecular ; Gene Expression ; Genes, Plant ; Lipoproteins/classification/*genetics/metabolism ; Molecular Sequence Data ; Plant Proteins/classification/*genetics/metabolism ; Plants/*genetics/metabolism ; Sequence Homology, Amino Acid ; Triticum/genetics/metabolism ; }, abstract = {Lipocalins are a group of proteins that have been characterized in bacteria, invertebrate, and vertebrate animals. However, very little is known about plant lipocalins. We have previously reported the cloning of the first true plant lipocalins. Here we report the identification and characterization of plant lipocalins and lipocalin-like proteins using an integrated approach of data mining, expression studies, cellular localization, and phylogenetic analyses. Plant lipocalins can be classified into two groups, temperature-induced lipocalins (TILs) and chloroplastic lipocalins (CHLs). In addition, violaxanthin de-epoxidases (VDEs) and zeaxanthin epoxidases (ZEPs) can be classified as lipocalin-like proteins. CHLs, VDEs, and ZEPs possess transit peptides that target them to the chloroplast. On the other hand, TILs do not show any targeting peptide, but localization studies revealed that the proteins are found at the plasma membrane. Expression analyses by quantitative real-time PCR showed that expression of the wheat (Triticum aestivum) lipocalins and lipocalin-like proteins is associated with abiotic stress response and is correlated with the plant's capacity to develop freezing tolerance. In support of this correlation, data mining revealed that lipocalins are present in the desiccation-tolerant red algae Porphyra yezoensis and the cryotolerant marine yeast Debaryomyces hansenii, suggesting a possible association with stress-tolerant organisms. Considering the plant lipocalin properties, tissue specificity, response to temperature stress, and their association with chloroplasts and plasma membranes of green leaves, we hypothesize a protective function of the photosynthetic system against temperature stress. Phylogenetic analyses suggest that TIL lipocalin members in higher plants were probably inherited from a bacterial gene present in a primitive unicellular eukaryote. On the other hand, CHLs, VDEs, and ZEPs may have evolved from a cyanobacterial ancestral gene after the formation of the cyanobacterial endosymbiont from which the chloroplast originated.}, }
@article {pmid16304620, year = {2005}, author = {Puttaraju, HP and Prakash, BM}, title = {Wolbachia and reproductive conflict in Exorista sorbillans.}, journal = {Archives of insect biochemistry and physiology}, volume = {60}, number = {4}, pages = {230-235}, doi = {10.1002/arch.20069}, pmid = {16304620}, issn = {0739-4462}, mesh = {Analysis of Variance ; Animals ; Anti-Bacterial Agents/toxicity ; Bombyx/*parasitology ; Crosses, Genetic ; Diptera/*microbiology/*physiology ; Fertility/physiology ; Host-Parasite Interactions/physiology ; Reproduction/physiology ; Sex Ratio ; *Symbiosis ; Wolbachia/drug effects/*physiology ; }, abstract = {Many arthropods harbour endosymbiotic bacteria of the genus Wolbachia. These endosymbionts are transmitted vertically from one generation to the next and are obligatory in several Dipterans that have been studied to date. These bacteria induce an array of reproductive isolation mechanisms that are implicated in pest management to evolutionary biology of respective hosts. The uzifly, Exorista sorbillans, a tachinid endoparasitoid of the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae), causes enormous losses to the silk industry; now it is known that it harbours Wolbachia endobacteria. The elimination of Wolbachia by antibiotics interrupts embryogenesis and causes various reproductive conflicts such as (1) a reduction of fecundity of uninfected female, (2) cytoplasmic incompatibility in the uninfected females crossed with infected males, (3) genomic incompatibility in crosses between males and females from uninfected population, and (4) sex-ratio distortion in uninfected females irrespective of the presence of Wolbachia in males. These results suggest that the relationship of Wolbachia with its uzifly host is one of mutual symbiosis as it controls the reproductive physiology of its host.}, }
@article {pmid16299326, year = {2005}, author = {Kerepesi, LA and Leon, O and Lustigman, S and Abraham, D}, title = {Protective immunity to the larval stages of onchocerca volvulus is dependent on Toll-like receptor 4.}, journal = {Infection and immunity}, volume = {73}, number = {12}, pages = {8291-8297}, pmid = {16299326}, issn = {0019-9567}, support = {R01 AI047189/AI/NIAID NIH HHS/United States ; AI042328/AI/NIAID NIH HHS/United States ; AI47189/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Antibody Formation ; Helminth Proteins/immunology ; Interferon-gamma/metabolism ; Larva/immunology/ultrastructure ; Mice ; Mice, Mutant Strains ; Onchocerca volvulus/growth &amp; development/*immunology/microbiology ; Onchocerciasis/genetics/*immunology ; Spleen/cytology ; Symbiosis ; Th2 Cells/immunology ; Toll-Like Receptor 4/genetics/*physiology ; Wolbachia/immunology/ultrastructure ; }, abstract = {Toll-like receptor 4 (TLR4) has been shown to be important for the induction of Th2-dependent immune responses in mice. Protective immunity against larval Onchocerca volvulus in mice depends on the development of a Th2 immune response mediated by both interleukin-4 (IL-4) and IL-5. In addition, O. volvulus contains the rickettsial endosymbiont Wolbachia, which has molecules with lipopolysaccharide-like activities that also signal through TLR4. We therefore hypothesized that protective immunity to O. volvulus would not develop in C3H/HeJ mice which have a mutation in the Tlr4 gene (TLR4 mutant), either because of a decreased Th2 response to the larvae or because of the absence of a response to Wolbachia. TLR4-mutant mice were immunized against O. volvulus with irradiated third-stage larvae, and it was observed that Th2 responses were elevated based on increased IL-5 production, total immunoglobulin E (IgE) levels, antigen-specific IgG1 response, and eosinophil recruitment. Protective immunity, however, did not develop in the TLR4-mutant mice. The Th1 response, as measured by gamma interferon production from spleen cells, was comparable in both wild-type and TLR4-mutant mice. Furthermore, antibody responses to Wolbachia were absent in both wild-type and TLR4-mutant mice. Therefore, the defect in the development of a protective immune response against O. volvulus in TLR4-mutant mice is not due to loss of Th2 immunity or the response to Wolbachia but is due to an unidentified TLR4-dependent larval killing mechanism.}, }
@article {pmid16288906, year = {2005}, author = {Kurtti, TJ and Simser, JA and Baldridge, GD and Palmer, AT and Munderloh, UG}, title = {Factors influencing in vitro infectivity and growth of Rickettsia peacockii (Rickettsiales: Rickettsiaceae), an endosymbiont of the Rocky Mountain wood tick, Dermacentor andersoni (Acari, Ixodidae).}, journal = {Journal of invertebrate pathology}, volume = {90}, number = {3}, pages = {177-186}, pmid = {16288906}, issn = {0022-2011}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R21 AI049424/AI/NIAID NIH HHS/United States ; AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Dermacentor/growth &amp; development/*parasitology/ultrastructure ; Female ; Host-Parasite Interactions ; Microscopy, Electron, Transmission ; Rickettsia/pathogenicity/*physiology ; Rickettsia Infections/*microbiology/physiopathology ; Symbiosis ; }, abstract = {Rickettsia peacockii, a spotted fever group rickettsia, is a transovarially transmitted endosymbiont of Rocky Mountain wood ticks, Dermacentor andersoni. This rickettsia, formerly known as the East Side Agent and restricted to female ticks, was detected in a chronically infected embryonic cell line, DAE100, from D. andersoni. We examined infectivity, ability to induce cytopathic effect (CPE) and host cell specificity of R. peacockii using cultured arthropod and mammalian cells. Aposymbiotic DAE100 cells were obtained using oxytetracycline or incubation at 37 degrees C. Uninfected DAE100 sublines grew faster than the parent line, indicating R. peacockii regulation of host cell growth. Nevertheless, DAE100 cellular defenses exerted partial control over R. peacockii growth. Rickettsiae existed free in the cytosol of DAE100 cells or within autophagolysosomes. Exocytosed rickettsiae accumulated in the medium and were occasionally contained within host membranes. R. peacockii multiplied in other cell lines from the hard ticks D. andersoni, Dermacentor albipictus, Ixodes scapularis, and Ixodes ricinus; the soft tick Carios capensis; and the lepidopteran Trichoplusia ni. Lines from the tick Amblyomma americanum, the mosquito Aedes albopictus, and two mammalian cell lines were non-permissive to R. peacockii. High cell densities facilitated rickettsial spread within permissive cell cultures, and an inoculum of one infected to nine uninfected cells resulted in the greatest yield of infected tick cells. Cell-free R. peacockii also were infectious for tick cells and centrifugation onto cell layers enhanced infectivity approximately 100-fold. The ability of R. peacockii to cause mild CPE suggests that its pathogenicity is not completely muted. An analysis of R. peacockii-cell interactions in comparison to pathogenic rickettsiae will provide insights into host cell colonization mechanisms.}, }
@article {pmid16286717, year = {2005}, author = {Maekawa, K and Kon, M and Matsumoto, T and Araya, K and Lo, N}, title = {Phylogenetic analyses of fat body endosymbionts reveal differences in invasion times of blaberid wood-feeding cockroaches (Blaberidae: Panesthiinae) into the Japanese archipelago.}, journal = {Zoological science}, volume = {22}, number = {10}, pages = {1061-1067}, doi = {10.2108/zsj.22.1061}, pmid = {16286717}, issn = {0289-0003}, mesh = {Animals ; Base Sequence ; Bayes Theorem ; Cockroaches/*microbiology/*physiology ; *Demography ; Evolution, Molecular ; Fat Body/*microbiology ; Flavobacteriaceae/*genetics ; Geography ; Japan ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Population Dynamics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Cockroaches have endosymbiotic bacteria in their fat bodies. Recent molecular phylogenetic analyses on both hosts and endosymbionts have revealed that co-evolution has occurred throughout the history of cockroaches and termites. Co-cladogenesis was also shown among closely related taxa (woodroach genus Cryptocercus; Cryptocercidae), and thus endosymbiont data are likely to be useful for biogeographical analyses. To test the possibility of co-cladogenesis among inter-and intraspecific taxa, as well as the utility of endosymbiont data for inferring biogeographical scenarios, we analyzed rRNA genes of endosymbionts of Japanese and Taiwanese Panesthiinae (Salganea and Panesthia; Blaberidae), on which phylogenetic analyses previously had been performed based on the mitochondrial genes. Statistical analyses on the topologies inferred from both endosymbiont and host mitochondria genes showed that co-cladogenesis has occurred. The endosymbiont sequences examined appear to have evolved in a clock-like manner, and their rate of evolution based on the host fossil data showed a major difference in the time of invasion of the two Japanese genera, that is congruent with the recent analyses of their mitochondrial genes.}, }
@article {pmid16274474, year = {2005}, author = {Sahu, BR and Mohapatra, AD and Majumder, A and Das, PK and Ravindran, B}, title = {A flow cytometry based method for studying embryogenesis and immune reactivity to embryogenic stages in filarial parasites.}, journal = {Filaria journal}, volume = {4}, number = {1}, pages = {11}, pmid = {16274474}, issn = {1475-2883}, abstract = {BACKGROUND: In the absence of intermediate animal hosts, the process of embryogenesis leading to fecundity of adult female filarial worms is very critical for persistence of these obligate parasites in human communities. Embryogenesis in adult female filarial parasites involves fertilization of eggs or oocytes by sperms and their subsequent development into motile microfilariae inside the uterine cavity of worms. Development of assays for monitoring embryogenesis in adult female worms is a critical requirement in filariasis research--filarial worms are known to harbour endosymbionts such as Wolbachia which play a significant role in fecundity. Tetracycline or doxycycline treatment of the infected hosts effectively eliminates the endosymbionts resulting in inhibition of embryogenesis in female worms. Currently, inhibition of embryogenesis in adult filarial worms can be monitored only by microscopic examination of in vitro harvested intrauterine stages.<br><br>METHODS: Adult female filarial worms of bovine filarial parasites, Setaria digitata were collected from the peritoneum of infected animals and intrauterine stages were harvested in culture medium and were analyzed for forward and side scatter by flowcytometry using a BD FACS Calibur. Different populations were gated, sorted and identified by phase microscopy. Binding of biotinylated lectins to intra uterine stages was monitored using FITC labeled Avidin and monitored by flow cytometry of gated populations. Similarly, binding of antibodies in human filarial sera to intrauterine stages was monitored using FITC labeled anti-human immunoglobulins.<br><br>RESULTS: The forward and side scatter for intrauterine stages delineated 3 distinct populations labeled as R1, R2 and R3. The three populations were sorted and identified to be a) fully stretched microfilariae, b) early and c) late developmental stages of eggs respectively. Lectins such as Wheat Germ agglutinin or Concanavalin-A were found to bind strongly to egg stages and less prominently to intra-uterine microfilariae. Similarly the binding of antibodies in filarial sera to the three intra-uterine stages could also be precisely quantified.<br><br>CONCLUSION: The manuscript reports a novel flow cytometry based method to monitor progression of embryogenesis in adult filarial worms. Apart from relative quantification of different intra uterine developmental stages, the assay allows quantitative binding of lectins and antibodies to each of the intrauterine stages. It may now be possible to quantify levels of antibodies in infected and immune hosts to monitor anti-fecundity immunity in filariasis--the assay can thus be used as a powerful tool for drug development and in immunological studies in human and experimental filariasis.}, }
@article {pmid16269811, year = {2005}, author = {Kugeler, KJ and Gurfield, N and Creek, JG and Mahoney, KS and Versage, JL and Petersen, JM}, title = {Discrimination between Francisella tularensis and Francisella-like endosymbionts when screening ticks by PCR.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {11}, pages = {7594-7597}, pmid = {16269811}, issn = {0099-2240}, mesh = {Animals ; Francisella/*classification/genetics/isolation &amp; purification ; Francisella tularensis/*classification/genetics/isolation &amp; purification ; Molecular Sequence Data ; Polymerase Chain Reaction/*methods ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; Ticks/*microbiology ; Tularemia/microbiology/transmission ; }, abstract = {The presence of Francisella-like endosymbionts in tick species known to transmit tularemia poses a potential diagnostic problem for laboratories that screen tick samples by PCR for Francisella tularensis. Tick samples initially considered positive for F. tularensis based on standard 16S rRNA gene PCR were found to be positive only for Francisella-like endosymbionts using a multitarget F. tularensis TaqMan assay (ISFtu2, tul4, and iglC) and 16S rRNA gene sequencing. Specificity of PCR-based diagnostics for F. tularensis should be carefully evaluated with appropriate specimen types prior to diagnostic use.}, }
@article {pmid16269768, year = {2005}, author = {Chi, F and Shen, SH and Cheng, HP and Jing, YX and Yanni, YG and Dazzo, FB}, title = {Ascending migration of endophytic rhizobia, from roots to leaves, inside rice plants and assessment of benefits to rice growth physiology.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {11}, pages = {7271-7278}, pmid = {16269768}, issn = {0099-2240}, mesh = {Colony Count, Microbial ; Green Fluorescent Proteins/genetics/metabolism ; Microscopy, Confocal ; Oryza/*growth &amp; development/*microbiology ; Plant Leaves/*microbiology ; Plant Roots/*microbiology ; Rhizobium/genetics/metabolism/*physiology/ultrastructure ; }, abstract = {Rhizobia, the root-nodule endosymbionts of leguminous plants, also form natural endophytic associations with roots of important cereal plants. Despite its widespread occurrence, much remains unknown about colonization of cereals by rhizobia. We examined the infection, dissemination, and colonization of healthy rice plant tissues by four species of gfp-tagged rhizobia and their influence on the growth physiology of rice. The results indicated a dynamic infection process beginning with surface colonization of the rhizoplane (especially at lateral root emergence), followed by endophytic colonization within roots, and then ascending endophytic migration into the stem base, leaf sheath, and leaves where they developed high populations. In situ CMEIAS image analysis indicated local endophytic population densities reaching as high as 9 x 10(10) rhizobia per cm3 of infected host tissues, whereas plating experiments indicated rapid, transient or persistent growth depending on the rhizobial strain and rice tissue examined. Rice plants inoculated with certain test strains of gfp-tagged rhizobia produced significantly higher root and shoot biomass; increased their photosynthetic rate, stomatal conductance, transpiration velocity, water utilization efficiency, and flag leaf area (considered to possess the highest photosynthetic activity); and accumulated higher levels of indoleacetic acid and gibberellin growth-regulating phytohormones. Considered collectively, the results indicate that this endophytic plant-bacterium association is far more inclusive, invasive, and dynamic than previously thought, including dissemination in both below-ground and above-ground tissues and enhancement of growth physiology by several rhizobial species, therefore heightening its interest and potential value as a biofertilizer strategy for sustainable agriculture to produce the world's most important cereal crops.}, }
@article {pmid16269725, year = {2005}, author = {Mavingui, P and Van, VT and Labeyrie, E and Rancès, E and Vavre, F and Simonet, P}, title = {Efficient procedure for purification of obligate intracellular Wolbachia pipientis and representative amplification of its genome by multiple-displacement amplification.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {11}, pages = {6910-6917}, pmid = {16269725}, issn = {0099-2240}, mesh = {Animals ; Bacteriological Techniques ; Cell Line ; DNA, Bacterial/*analysis/*isolation &amp; purification ; Drosophila/growth &amp; development/*microbiology ; Electrophoresis, Gel, Pulsed-Field ; *Genome, Bacterial ; Molecular Sequence Data ; Nucleic Acid Amplification Techniques/*methods ; Ovum/microbiology ; Sequence Analysis, DNA ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Bacteria belonging to the genus Wolbachia are obligatory microendocytobionts that infect a variety of arthropods and a majority of filarial nematode species, where they induce reproductive alterations or establish a mutualistic symbiosis. Although two whole genome sequences of Wolbachia pipientis, for strain wMel from Drosophila melanogaster and strain wBm from Brugia malayi, have been fully completed and six other genome sequencing projects are ongoing (http://www.genomesonline.org/index.cgi?want=Prokaryotic+Ongoin), genetic analyses of these bacteria are still scarce, mainly due to the inability to cultivate them outside of eukaryotic cells. Usually, a large amount of host tissue (a thousand individuals, or about 10 g) is required in order to purify Wolbachia and extract its DNA, which is often recovered in small amounts and contaminated by host cell DNA, thus hindering genomic studies. In this report, we describe an efficient and reliable procedure to representatively amplify the Wolbachia genome by multiple-displacement amplification from limited infected host tissue (0.2 g or 2 x 10(7) cells). We obtained sufficient amounts (8 to 10 microg) of DNA of suitable quality for genomic studies, and we demonstrated that the amplified DNA contained all of the Wolbachia loci targeted. In addition, our data indicated that the genome of strain wRi, an obligatory endosymbiont of Drosophila simulans, shares a similar overall architecture with its relative strain wMel.}, }
@article {pmid16252129, year = {2005}, author = {Bordenstein, S and Rosengaus, RB}, title = {Discovery of a novel Wolbachia super group in Isoptera.}, journal = {Current microbiology}, volume = {51}, number = {6}, pages = {393-398}, pmid = {16252129}, issn = {0343-8651}, mesh = {Animals ; Bacterial Proteins/genetics ; Chaperonin 60/genetics ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Genetic Variation ; Isoptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Wolbachia/*classification/genetics/*isolation &amp; purification ; }, abstract = {Wolbachia are one of the most abundant groups of bacterial endosymbionts in the biosphere. Interest in these heritable microbes has expanded with the discovery of wider genetic diversity in under-sampled host species. Here, we report on the putative discovery of a new genetic lineage, denoted super group H, which infects the Isopteran species Zootermopsis angusticollis and Z. nevadensis. Evidence for this novel super group is based on portions of new Wolbachia gene sequences from each species spanning 3.5 kilobases of DNA and the following genes: 16S rDNA, dnaA, gltA, groEL, and ftsZ. Single-gene and concatenated maximum likelihood phylogenies establish this new super group and validate the positioning of the other Wolbachia super groups. This discovery is the first example of a termite Wolbachia that is highly divergent from the Isopteran Wolbachia previously described in super group F. This study highlights the importance of multilocus approaches to resolving Wolbachia super group relationships. It also suggests that surveys of Wolbachia in more earlier-originating (and under-sampled) groups of arthropods are more apt to reveal novel genetic diversity.}, }
@article {pmid16233803, year = {2005}, author = {Blanco, Y and Blanch, M and Piñón, D and Legaz, ME and Vicente, C}, title = {Antagonism of Gluconacetobacter diazotrophicus (a sugarcane endosymbiont) against Xanthomonas albilineans (pathogen) studied in alginate-immobilized sugarcane stalk tissues.}, journal = {Journal of bioscience and bioengineering}, volume = {99}, number = {4}, pages = {366-371}, doi = {10.1263/jbb.99.366}, pmid = {16233803}, issn = {1389-1723}, mesh = {Bacteriocins/*biosynthesis/*pharmacology ; Gluconacetobacter/*physiology ; Plant Diseases/chemically induced/*microbiology ; Plant Shoots/drug effects/growth &amp; development/microbiology ; Saccharum/*drug effects/growth &amp; development/*microbiology ; Symbiosis/physiology ; Xanthomonas/pathogenicity/*physiology ; }, abstract = {Xanthomonas albilineans, a pathogenic bacterium that produces leaf scald disease of sugarcane, secretes a xanthan-like gum that invades both xylem and phloem of the host. Xanthan production has been verified after experimental infection of stalk segments of healthy plants. Moreover, Gluconacetobacter diazotrophicus is a nitrogen-fixing endosymbiont of sugarcane plants that antagonizes with X. albilineans by impeding the production of the bacterial gum. The physiological basis of this antagonism has been studied using tissues of sugarcane stalks previously inoculated with the endosymbiont, then immobilized in calcium alginate and maintained in a culture medium for Gluconacetobacter. Under these conditions, bacteria infecting immobilized tissues are able to secrete to the medium a lysozyme-like bacteriocin that inhibits the growth of X. albilineans.}, }
@article {pmid16230105, year = {2005}, author = {Taylor, MJ and Bandi, C and Hoerauf, A}, title = {Wolbachia bacterial endosymbionts of filarial nematodes.}, journal = {Advances in parasitology}, volume = {60}, number = {}, pages = {245-284}, doi = {10.1016/S0065-308X(05)60004-8}, pmid = {16230105}, issn = {0065-308X}, mesh = {Animals ; Anti-Bacterial Agents/therapeutic use ; Antibodies, Bacterial/biosynthesis ; Arthropods/*microbiology ; Dogs ; Doxycycline/therapeutic use ; Environment ; *Filariasis/drug therapy/microbiology/parasitology ; Genomics ; Humans ; Inflammation Mediators/metabolism ; Nematoda/*microbiology ; Phylogeny ; Population Dynamics ; *Symbiosis ; Wolbachia/classification/drug effects/growth &amp; development/*physiology ; }, abstract = {Filarial nematodes are important helminth parasites of the tropics and a leading cause of global disability. They include species responsible for onchocerciasis, lymphatic filariasis and dirofilariasis. A unique feature of these nematodes is their dependency upon a symbiotic intracellular bacterium, Wolbachia, which is essential for normal development and fertility. Advances in our understanding of the symbiosis of Wolbachia bacteria with filarial nematodes have made rapid progress in recent years. Here we summarise our current understanding of the evolution of the symbiotic association together with insights into the functional basis of the interaction derived from genomic analysis. Also we discuss the contribution of Wolbachia to inflammatory-mediated pathogenesis and adverse reactions to anti-filarial drugs and describe the outcome of recent field trials using antibiotics as a promising new tool for the treatment of filarial infection and disease.}, }
@article {pmid16224014, year = {2005}, author = {Okamoto, N and Inouye, I}, title = {A secondary symbiosis in progress?.}, journal = {Science (New York, N.Y.)}, volume = {310}, number = {5746}, pages = {287}, doi = {10.1126/science.1116125}, pmid = {16224014}, issn = {1095-9203}, mesh = {Animals ; Chlorophyta/*physiology ; Eukaryota/*microbiology ; Plastids ; *Symbiosis ; }, abstract = {Algae have acquired plastids by developing an endosymbiotic relationship with either a cyanobacterium (primary endosymbiosis) or other eukaryotic algae (secondary endosymbiosis). We report a protist, which we tentatively refer to as Hatena, that hosts an endosymbiotic green algal partner but inherits it unevenly. The endosymbiosis causes drastic morphological changes to both the symbiont and the host cell architecture. This type of life cycle, in which endosymbiont integration has only partially converted the host from predator to autotroph, may represent an early stage of plastid acquisition through secondary symbiosis.}, }
@article {pmid16216441, year = {2005}, author = {d'Avila-Levy, CM and Silva, BA and Hayashi, EA and Vermelho, AB and Alviano, CS and Saraiva, EM and Branquinha, MH and Santos, AL}, title = {Influence of the endosymbiont of Blastocrithidia culicis and Crithidia deanei on the glycoconjugate expression and on Aedes aegypti interaction.}, journal = {FEMS microbiology letters}, volume = {252}, number = {2}, pages = {279-286}, doi = {10.1016/j.femsle.2005.09.012}, pmid = {16216441}, issn = {0378-1097}, mesh = {Aedes/*parasitology ; Animals ; *Bacterial Physiological Phenomena ; Blotting, Western ; Crithidia/*metabolism/*microbiology ; Digestive System/parasitology ; Flow Cytometry ; Glycoconjugates/*analysis/biosynthesis/physiology ; Lectins/metabolism ; Mannose/physiology ; N-Acetylneuraminic Acid/physiology ; Staining and Labeling ; Symbiosis ; Trypanosomatina/*metabolism/*microbiology ; }, abstract = {Blastocrithidia culicis and Crithidia deanei are trypanosomatid protozoa of insects that normally contain intracellular symbiotic bacteria. The protozoa can be rid of their endosymbionts by antibiotics, producing a cured cell line. Here, we analyzed the glycoconjugate profiles of endosymbiont-harboring and cured strains of B. culicis and C. deanei by Western blotting and flow cytometry analyses using lectins that recognize specifically sialic acid and mannose-like residues. The absence of the endosymbiont increased the intensity of the lectins binding on both trypanosomatids. In addition, wild and cured strain-specific glycoconjugate bands were identified. The role of the surface saccharide residues on the interaction with explanted guts from Aedes aegypti gut was assessed. The aposymbiotic strains of B. culicis and C. deanei presented interaction rates 3.3- and 2.3-fold lower with the insect gut, respectively, when compared with the endosymbiont-bearing strains. The interaction rate of sialidase-treated cells of the wild and cured strains of B. culicis and C. deanei was reduced in at least 90% in relation to the control. The interaction of B. culicis (wild strain) with explanted guts was inhibited in the presence of mucin (56%), fetuin (62%), sialyllactose (64%) and alpha-methyl-D-mannoside (80%), while in C. deanei (wild strain) the inhibition was 53%, 56%, 79% and 34%, respectively. Collectively, our results suggest a possible involvement of sialomolecules and mannose-rich glycoconjugates in the interaction between insect trypanosomatids and the invertebrate host.}, }
@article {pmid16199572, year = {2005}, author = {Manyani, H and Rey, L and Palacios, JM and Imperial, J and Ruiz-Argüeso, T}, title = {Gene products of the hupGHIJ operon are involved in maturation of the iron-sulfur subunit of the [NiFe] hydrogenase from Rhizobium leguminosarum bv. viciae.}, journal = {Journal of bacteriology}, volume = {187}, number = {20}, pages = {7018-7026}, pmid = {16199572}, issn = {0021-9193}, mesh = {Hydrogenase/chemistry/*genetics/*metabolism ; Iron/*metabolism ; Membrane Proteins/chemistry/genetics/metabolism ; Operon/physiology ; Oxygen/metabolism ; Protein Subunits/genetics ; Rhizobium leguminosarum/*enzymology/*metabolism ; Sulfur/*metabolism ; Symbiosis/physiology ; }, abstract = {In the present study, we investigate the functions of the hupGHIJ operon in the synthesis of an active [NiFe] hydrogenase in the legume endosymbiont Rhizobium leguminosarum bv. viciae. These genes are clustered with 14 other genes including the hydrogenase structural genes hupSL. A set of isogenic mutants with in-frame deletions (deltahupG, deltahupH, deltahupI, and deltahupJ) was generated and tested for hydrogenase activity in cultures grown at different oxygen concentrations (0.2 to 2.0%) and in symbiosis with peas. In free-living cultures, deletions in these genes severely reduced hydrogenase activity. The deltahupH mutant was totally devoid of hydrogenase activity at any of the O2 concentration tested, whereas the requirement of hupGIJ for hydrogenase activity varied with the O2 concentration, being more crucial at higher pO2. Pea bacteroids from the mutant strains affected in hupH, hupI, and hupJ exhibited reduced (20 to 50%) rates of hydrogenase activity compared to the wild type, whereas rates were not affected in the deltahupG mutant. Immunoblot experiments with HupL- and HupS-specific antisera showed that free-living cultures from deltahupH, deltahupI, and deltahupJ mutants synthesized a fully processed mature HupL protein and accumulated an unprocessed form of HupS (pre-HupS). Both the mature HupL and the pre-HupS forms were located in the cytoplasmic fraction of cultures from the deltahupH mutant. Affinity chromatography experiments revealed that cytoplasmic pre-HupS binds to the HupH protein before the pre-HupS-HupL complex is formed. From these results we propose that hupGHIJ gene products are involved in the maturation of the HupS hydrogenase subunit.}, }
@article {pmid16199029, year = {2006}, author = {Kádár, E and Santos, RS and Powell, JJ}, title = {Biological factors influencing tissue compartmentalization of trace metals in the deep-sea hydrothermal vent bivalve Bathymodiolus azoricus at geochemically distinct vent sites of the Mid-Atlantic Ridge.}, journal = {Environmental research}, volume = {101}, number = {2}, pages = {221-229}, doi = {10.1016/j.envres.2005.08.010}, pmid = {16199029}, issn = {0013-9351}, support = {MC_U105960399/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Animals ; Metals/*metabolism ; Mollusca/*metabolism ; Reference Standards ; Reproducibility of Results ; }, abstract = {In this study, we investigated on concentrations of trace metals (Al, Cd, Mn, Co, and Hg) in the hydrothermal bivalve Bathymodiolus azoricus, a dominant species at most vent sites along the Mid-Atlantic Ridge (MAR), and in its endosymbiont bacteria and commensal parasite Branchipolynoe seepensis. Comparison of our results with data from the literature on non-hydrothermal bivalves suggests lack of "extreme" uptake of trace metals by B. azoricus, except for Hg concentration which exceeded manyfold previously reported values. Mussels collected from three geochemically distinct vent sites, Menez Gwen, Lucky Strike, and Rainbow, along the MAR showed significant differences in tissue concentration of metals. Proportionality of metals in soft tissues of mussels reflected variation of water chemistry at different vents, which in turn conserved the order of trace metal prevalence in undiluted fluids. There were significant tissue-specific differences in trace metal compartmentalization for all metals investigated. Byssus thread contained the highest metal concentration among examined tissues, and thus it is suggested to be an important detoxification route. Size-dependent differences in metal concentrations were detected only for Hg, revealing a general trend of small mussels accumulating more metal than big mussels. Endosymbiont bacteria are shown to exclusively sequester Al from the host gill and contribute to removal of other toxic metals in mussels from Menez Gwen. The commensal parasite present in all mussels from Lucky Strike had higher tissue concentrations of Mn, Al, and Co than the host gill, unlike Cd and Hg which were considerably lower in the former, and thus its role in detoxification remains unclear. Bioaccumulation potential of vent bivalves and associated organisms are quantified as concentration factors and compared to make inferences on the putative role of the endosymbiont bacteria and the commensal parasite in detoxification of trace metals.}, }
@article {pmid16198821, year = {2005}, author = {Simón, F and López-Belmonte, J and Marcos-Atxutegi, C and Morchón, R and Martín-Pacho, JR}, title = {What is happening outside North America regarding human dirofilariasis?.}, journal = {Veterinary parasitology}, volume = {133}, number = {2-3}, pages = {181-189}, doi = {10.1016/j.vetpar.2005.03.033}, pmid = {16198821}, issn = {0304-4017}, mesh = {Animals ; Antibodies, Bacterial/analysis/*blood ; Dirofilaria/*microbiology ; Dirofilaria immitis/microbiology ; Dirofilariasis/blood/*epidemiology/parasitology/transmission ; Europe/epidemiology ; Humans ; Sentinel Surveillance ; Seroepidemiologic Studies ; Symbiosis ; Wolbachia/*immunology ; }, abstract = {The etiologic agents of human dirofilariasis in the Old World are Dirofilaria immitis, which cause pulmonary and subcutaneous nodules, and Dirofilaria repens, which cause ocular lesions. Although reports of new cases of dirofilariasis are sporadic in other parts of the world, a considerable amount of information is generated in Europe regarding human dirofilariasis. Most cases have been detected in the Mediterranean countries, Ukraine, and Russia; however, isolated or short series of cases have been reported in the Balkan Republics and central and northern European countries. Seroepidemiologic studies have provided evidence that humans living in endemic areas present rates of infection similar to those of the autochthonous canine populations. Antibodies against endosymbiont Wolbachia bacteria have been demonstrated recently in human Dirofilaria infections. During D. immitis infections, preadult worms and third- and fourth-stage larvae are often destroyed by the host reaction, releasing a considerable amount of Wolbachia, and a Th1-type response against Wolbachia and/or filarial antigens is mounted. On the contrary, infections with D. repens, in which worms frequently remain intact, no Th1-type response has been observed. As humans are resistant hosts, the Th1-response could have a role in the resistance against parasites. The causes for the rise in the incidence of human dirofilariasis as well as the possible application of Wolbachia antigens in the serodiagnosis of human infections are discussed.}, }
@article {pmid16198819, year = {2005}, author = {Kozek, WJ}, title = {What is new in the Wolbachia/Dirofilaria interaction?.}, journal = {Veterinary parasitology}, volume = {133}, number = {2-3}, pages = {127-132}, doi = {10.1016/j.vetpar.2005.02.005}, pmid = {16198819}, issn = {0304-4017}, support = {2 S06 GM8224/GM/NIGMS NIH HHS/United States ; AI 12095/AI/NIAID NIH HHS/United States ; RR-03051/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Antigens, Bacterial/analysis ; Cats ; Dirofilaria immitis/*microbiology ; Dirofilariasis/diagnosis/*parasitology ; Dogs ; Female ; Life Cycle Stages ; Male ; Symbiosis ; *Wolbachia/growth &amp; development/immunology/pathogenicity/physiology ; }, abstract = {Presence of transovarially-transmitted endosymbiontic Wolbachia bacteria in Dirofilaria immitis, and in other filariae of man and animals, presents a new paradigm for our understanding of pathogenesis, treatment and diagnosis of filarial infections. Many of the basic biological characteristics of Wolbachia have yet to be elucidated, but the results obtained to date suggest that canine or the feline hosts can be exposed to D. immitis Wolbachia when larvae, or adult worms, are killed; when Wolbachia are expulsed, with the deposition of microfilariae, from the uterus of the females; and possibly through the excretory system of both male and female worms. The two organs that have the greatest potential of being affected by the Wolbachial metabolic products/antigens released from the adult worms are the lungs and the kidneys. Population of Wolbachia in D. immitis is polymorphic. The life cycle of Wolbachia is complex and may consist of two reproductive modes: multiplication of the bacillary forms by binary fission and by a more complex mode which resembles the Chlamydia-like cycle that consists of three morphological stages: a small, dense body, an intermediate stage with a dense inclusion, and a bacillary form which represents the final product of development and maturation of the small, dense body. The Chlamydia-like cycle offers a potential survival strategy for the Wolbachia by producing more progeny than multiplication by binary fission, and appears to be more active during growth and development of embryos and of the larvae. The small, dense bodies may be the infectious forms responsible for the spread of Wolbachia through the canalicular system, within the lateral chords of filariae. An amorphous membrane that lines the perienteric surface of the body wall may represent a physical barrier that limits the spread and movement of Wolbachia to the perienteric surface of the lateral chords. Wolbachia in D. immitis may also offer therapeutic and diagnostic possibilities. Elimination of Wolbachia by chemotherapy, and the suppressive effect of aposymbiosis on embryonic development of D. immitis, may have potential application for control (sterilization of female worms) and treatment of dirofilariasis. However, the three stages in the life cycle of Wolbachia may be antigenically different and each stage may have a different susceptibility to therapeutic agents. Persistence of dormant small, dense bodies after treatment would allow the Wolbachia to re-establish once the conditions for development would become favorable. Detection of Wolbachial antigens provides an attractive diagnostic possibility to identify D. immitis early in the infection. Further studies on Wolbachia of filariae, including those of D. immitis, will undoubtedly reveal additional information that can be applied towards treatment, diagnosis, and control of filarial infections.}, }
@article {pmid16195380, year = {2005}, author = {Moran, NA and Degnan, PH and Santos, SR and Dunbar, HE and Ochman, H}, title = {The players in a mutualistic symbiosis: insects, bacteria, viruses, and virulence genes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {102}, number = {47}, pages = {16919-16926}, pmid = {16195380}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology/*virology ; Bacterial Toxins/*genetics ; Buchnera/pathogenicity/physiology ; Chromosomes, Bacterial/genetics ; Enterobacteriaceae/genetics/*pathogenicity/physiology ; Female ; Humans ; Insect Viruses/*pathogenicity/physiology ; Molecular Sequence Data ; Sequence Analysis, DNA ; Sequence Analysis, Protein ; Symbiosis/*genetics ; Virulence/genetics ; }, abstract = {Aphids maintain mutualistic symbioses involving consortia of coinherited organisms. All possess a primary endosymbiont, Buchnera, which compensates for dietary deficiencies; many also contain secondary symbionts, such as Hamiltonella defensa, which confers defense against natural enemies. Genome sequences of uncultivable secondary symbionts have been refractory to analysis due to the difficulties of isolating adequate DNA samples. By amplifying DNA from hemolymph of infected pea aphids, we obtained a set of genomic sequences of H. defensa and an associated bacteriophage. H. defensa harbors two type III secretion systems, related to those that mediate host cell entry by enteric pathogens. The phage, called APSE-2, is a close relative of the previously sequenced APSE-1 but contains intact homologs of the gene encoding cytolethal distending toxin (cdtB), which interrupts the eukaryotic cell cycle and which is known from a variety of mammalian pathogens. The cdtB homolog is highly expressed, and its genomic position corresponds to that of a homolog of stx (encoding Shiga-toxin) within APSE-1. APSE-2 genomes were consistently abundant in infected pea aphids, and related phages were found in all tested isolates of H. defensa, from numerous insect species. Based on their ubiquity and abundance, these phages appear to be an obligate component of the H. defensa life cycle. We propose that, in these mutualistic symbionts, phage-borne toxin genes provide defense to the aphid host and are a basis for the observed protection against eukaryotic parasites.}, }
@article {pmid16175450, year = {2005}, author = {Chatterjee, SN and Taraphdar, T and Mohandas, TP}, title = {Molecular analysis of divergence in tachinid Uzi (Exorista sorbillans) populations in India.}, journal = {Genetica}, volume = {125}, number = {1}, pages = {1-15}, doi = {10.1007/s10709-004-6192-0}, pmid = {16175450}, issn = {0016-6707}, mesh = {Animals ; Bombyx/parasitology ; Climate ; Diptera/*genetics/*pathogenicity ; Gene Flow ; *Genetics, Population ; Genomics ; India ; Phylogeny ; }, abstract = {Exorista sorbillans is a tachinid endoparasitoid of silkworm, Bombyx mori, and is globally known as uzi. It causes economic injury to the cocoon crop in silkworm cultivating areas of India, except those above 400 m above mean sea level (AMSL) in the foothills of the Himalayas (Darjeeling). It is reported that the sericulture tract of south India became infected with this pest only since 1980 through an accidental transportation of cocoons from West Bengal. To ascertain whether the genome of this parasitoid is differentiating into discrete gene pools in contrasting geo-climatic conditions, molecular profiling of four populations (Es (Annatapur), Es(Ramanagaram), Es (Channapatna) and Es(Kodathi) from south India and Es(Murshidabad) from Murshidabad, West Bengal was undertaken with 13 ISSR, 3 RAPD and six non-random primers designed from various repeat sequences of B. mori . MANOVA indicated significance for the Roy's largest root estimate (55.4; F =18.47; p = 0.002) for the variability contributed by the replication. Further, hierarchical clustering done on the basis of Euclidean distance matrix and Nei's unbiased Phylip clustering put Es(Murshidabad) at the maximum distance from those of south India and 29 markers could also be identified which significantly differentiateEs(Murshidabad) from others. However, Nei's statistics for gene diversity in sub-populations reveal considerably high gene-flow (3.44 and 2.51) among the populations around Bangalore. The gene-flow between Es(Murshidabad) and other population is lowest but cannot be ignored. The comparison of endosymbiont specific 16SrRNA and fts Z gene (partial) sequences through clustalW (gcgMSF) revealed a closer relationship of Es(Murshidabad) with Es(Annatapur) and Es (Ramanagaram) and is not congruent with the relationships discussed above. The significance of this maiden study with a tachinid fly-pest is discussed in the context of understanding the diversification of Uzi fly-pest and also establishing this pest as a relevant biological material for studying microevolution in future.}, }
@article {pmid16172008, year = {2005}, author = {Andrade, MA and Siles-Lucas, M and Pérez Arellano, JL and Pou Barreto, C and Valladares, B and Espinoza, E and Muro, A}, title = {Increased rat alveolar macrophage expression of functional iNOS induced by a Dirofilaria immitis immunoglobulin superfamily protein.}, journal = {Nitric oxide : biology and chemistry}, volume = {13}, number = {4}, pages = {217-225}, doi = {10.1016/j.niox.2005.06.003}, pmid = {16172008}, issn = {1089-8603}, mesh = {Animals ; Antigens/chemistry/metabolism ; Cells, Cultured ; Dirofilaria immitis/*immunology ; Immunoglobulins/chemistry/classification/*pharmacology ; Macrophages, Alveolar/*drug effects/*enzymology ; Male ; Nitric Oxide/metabolism ; Nitric Oxide Synthase Type II/*metabolism ; Rats ; Rats, Wistar ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; }, abstract = {Dirofilaria immitis is a worldwide filarial nematode causing heartworm disease in dogs and cats. Several mosquito species, which are able to feed both on humans and animals, can transmit this parasite. Inflammatory progression of host tissues induced by parasites are mediated by several molecules, including nitric oxide (NO), which usually exerts deleterious effects on parasites and occasionally on the host. We analyze the in vitro effect of total D. immitis adult worm somatic antigens on naïve rat alveolar macrophage NO production and further separation of parasite proteins to define specific D. immitis somatic molecules influencing host cell NO secretion. Additionally, we address the possible influence of Wolbachia spp. on the in vitro production of NO by macrophages. Our results demonstrate that D. immitis adult worm soluble antigens are able to specifically induce NO production from host macrophages. Furthermore, we demonstrated that this effect is due to nematode antigens rather than to defined components (LPS and metabolic molecules) derived from its endosymbiont, Wolbachia spp. In addition, we were able to isolate and identify one of the parasite specific components from the DiSo extract, denominated DiID35.3 and putatively belonging to the Immunoglobulin Superfamily Protein (ISP) group, triggering NO release from macrophages in a dose-dependent and specific manner.}, }
@article {pmid16166679, year = {2005}, author = {Collingro, A and Toenshoff, ER and Taylor, MW and Fritsche, TR and Wagner, M and Horn, M}, title = {'Candidatus Protochlamydia amoebophila', an endosymbiont of Acanthamoeba spp.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {55}, number = {Pt 5}, pages = {1863-1866}, doi = {10.1099/ijs.0.63572-0}, pmid = {16166679}, issn = {1466-5026}, mesh = {Acanthamoeba/*microbiology ; Animals ; Chlamydiales/*classification/*genetics/growth &amp; development ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Genes, rRNA ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Ribonuclease P/genetics ; Ribosomal Proteins/genetics ; *Symbiosis ; }, abstract = {The obligately intracellular coccoid bacterium UWE25, a symbiont of Acanthamoeba spp., was previously identified as being related to chlamydiae based upon the presence of a chlamydia-like developmental cycle and its 16S rRNA gene sequence. Analysis of its complete genome sequence demonstrated that UWE25 shows many characteristic features of chlamydiae, including dependency on host-derived metabolites, composition of the cell envelope and the ability to thrive as an energy parasite within the cells of its eukaryotic host. Phylogenetic analysis of 44 ribosomal proteins further confirmed the affiliation of UWE25 to the 'Chlamydiae'. Within this phylum, UWE25 could be assigned to the family Parachlamydiaceae based on comparative analyses of the 16S rRNA, 23S rRNA and endoribonuclease P RNA genes. The distinct dissimilarities from its closest relative, Parachlamydia acanthamoebae Bn(9)(T) (7.1, 9.7 and 28.8%, respectively), observed in this analysis justify its classification in a new genus. Therefore, the name 'Candidatus Protochlamydia amoebophila' is proposed for the designation of the Acanthamoeba sp. symbiont UWE25 (=ATCC PRA-7).}, }
@article {pmid16153167, year = {2005}, author = {Baumann, P}, title = {Biology bacteriocyte-associated endosymbionts of plant sap-sucking insects.}, journal = {Annual review of microbiology}, volume = {59}, number = {}, pages = {155-189}, doi = {10.1146/annurev.micro.59.030804.121041}, pmid = {16153167}, issn = {0066-4227}, mesh = {Animals ; Betaproteobacteria/classification/genetics/*physiology ; Gammaproteobacteria/classification/genetics/*physiology ; Hemiptera/genetics/*microbiology ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {Psyllids, whiteflies, aphids, and mealybugs are members of the suborder Sternorrhyncha and share a common property, namely the utilization of plant sap as their food source. Each of these insect groups has an obligatory association with a different prokaryotic endosymbiont, and the association is the result of a single infection followed by maternal, vertical transmission of the endosymbionts. The result of this association is the domestication of the free-living bacterium to serve the purposes of the host, namely the synthesis of essential amino acids. This domestication is probably in all cases accompanied by a major reduction in genome size. The different properties of the genomes and fragments of the genomes of these endosymbionts suggest that there are different constraints on the permissible evolutionary changes that are probably a function of the gene repertoire of the endosymbiont ancestor and the gene losses that occurred during the reduction of genome size.}, }
@article {pmid16153037, year = {2005}, author = {Dyer, KA and Jaenike, J}, title = {Evolutionary dynamics of a spatially structured host-parasite association: Drosophila innubila and male-killing Wolbachia.}, journal = {Evolution; international journal of organic evolution}, volume = {59}, number = {7}, pages = {1518-1528}, pmid = {16153037}, issn = {0014-3820}, mesh = {Analysis of Variance ; Animals ; Arizona ; Bacterial Outer Membrane Proteins/genetics ; *Biological Evolution ; Cluster Analysis ; Drosophila/genetics/*microbiology ; Electron Transport Complex IV/genetics ; Founder Effect ; *Genetic Variation ; *Genetics, Population ; Geography ; Haplotypes/genetics ; Host-Parasite Interactions ; Population Dynamics ; Sequence Analysis, DNA ; Sex Factors ; *Sex Ratio ; *Symbiosis ; Wolbachia/genetics/*physiology ; }, abstract = {The mode and tempo of host-parasite evolution depend on population structure and history and the strength of selection that the species exert on each other. Here we genetically and epidemiologically characterize populations of the mycophagous fly Drosophila innubila and its male-killing Wolbachia endosymbiont, with the aim of integrating the local through global nature of this association. Drosophila innubila inhabit the forested "sky island" regions of the of the southwestern United States and northern Mexico, where its distribution is highly fragmented. We examine geographically isolated sky island populations of D. innubila, surveying the frequency and expression of Wolbachia infection as well as the distribution of genetic variation within and among populations of the host and parasite. In all populations, Wolbachia infection is associated with virtually complete male-killing, thus providing no evidence for the evolution of population-specific interaction phenotypes or local resistance. Although Wolbachia infection occurs in each of the main populations, there is variation among populations in the prevalence of infection and the resulting population-level sex ratio of D. innubila. Among these populations, the nuclear genes of D. innubila show moderate, though significant, differentiation. In contrast, the host mitochondrial DNA (mtDNA), which shares transmission with Wolbachia, exhibits substantially greater geographic differentiation, even after accounting for differences in transmission between nuclear and mitochondrial genes. We suggest that this pattern is caused by local Wolbachia--but not D. innubila--fluctuations in prevalence that increase the severity of drift experienced only by the mtDNA. Overall, our data suggest that the association between D. innubila and male-killing Wolbachia is ecologically dynamic within local populations, but evolutionarily coherent across the species as a whole.}, }
@article {pmid16151136, year = {2005}, author = {Suzuki, Y and Sasaki, T and Suzuki, M and Nogi, Y and Miwa, T and Takai, K and Nealson, KH and Horikoshi, K}, title = {Novel chemoautotrophic endosymbiosis between a member of the Epsilonproteobacteria and the hydrothermal-vent gastropod Alviniconcha aff. hessleri (Gastropoda: Provannidae) from the Indian Ocean.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {9}, pages = {5440-5450}, pmid = {16151136}, issn = {0099-2240}, mesh = {Animals ; Carbon Isotopes/metabolism ; Citric Acid Cycle ; Epsilonproteobacteria/chemistry/*classification/*genetics/growth &amp; development ; Fatty Acids/analysis ; Gills/microbiology ; In Situ Hybridization, Fluorescence ; Indian Ocean ; Mollusca/*growth &amp; development/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {The hydrothermal-vent gastropod Alviniconcha aff. hessleri from the Kairei hydrothermal field on the Central Indian Ridge houses bacterium-like cells internally in its greatly enlarged gill. A single 16S rRNA gene sequence was obtained from the DNA extract of the gill, and phylogenetic analysis placed the source organism within a lineage of the epsilon subdivision of the Proteobacteria. Fluorescence in situ hybridization analysis with an oligonucleotide probe targeting the specific epsilonproteobacterial subgroup showed the bacterium densely colonizing the gill filaments. Carbon isotopic homogeneity among the gastropod tissue parts, regardless of the abundance of the endosymbiont cells, suggests that the carbon isotopic composition of the endosymbiont biomass is approximately the same as that of the gastropod. Compound-specific carbon isotopic analysis revealed that fatty acids from the gastropod tissues are all (13)C enriched relative to the gastropod biomass and that the monounsaturated C(16) fatty acid that originates from the endosymbiont is as (13)C enriched relative to the gastropod biomass as that of the epsilonproteobacterial cultures grown under chemoautotrophic conditions. This fractionation pattern is most likely due to chemoautotrophy based on the reductive tricarboxylic-acid (rTCA) cycle and subsequent fatty acid biosynthesis from (13)C-enriched acetyl coenzyme A. Enzymatic characterization revealed evident activity of several key enzymes of the rTCA cycle, as well as the absence of ribulose-1,5-bisphosphate carboxylase/oxygenase activity in the gill tissue. The results from anatomic, molecular phylogenetic, bulk and compound-specific carbon isotopic, and enzymatic analyses all support the inference that a novel nutritional strategy relying on chemoautotrophy in the epsilonproteobacterial endosymbiont is utilized by the hydrothermal-vent gastropod from the Indian Ocean. The discrepancies between the data of the present study and those of previous ones for Alviniconcha gastropods from the Pacific Ocean imply that at least two lineages of chemoautotrophic bacteria, phylogenetically distinct at the subdivision level, occur as the primary endosymbiont in one host animal type.}, }
@article {pmid16151107, year = {2005}, author = {Perkins, SL and Budinoff, RB and Siddall, ME}, title = {New gammaproteobacteria associated with blood-feeding leeches and a broad phylogenetic analysis of leech endosymbionts.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {9}, pages = {5219-5224}, pmid = {16151107}, issn = {0099-2240}, support = {R01 GM062351/GM/NIGMS NIH HHS/United States ; 5R01 GM 062351-02/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; In Situ Hybridization, Fluorescence ; Leeches/anatomy &amp; histology/*microbiology ; Leeching ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Many monophagous animals have coevolutionary relationships with bacteria that provide unavailable nutrients to the host. Frequently, these microbial partners are vertically inherited and reside in specialized structures or tissues. Here we report three new lineages of bacterial symbionts of blood-feeding leeches, one from the giant Amazonian leech, Haementeria ghilianii, and two others from Placobdelloides species. These hosts each possess a different mycetome or esophageal organ morphology where the bacterial cells are located. DNA sequencing of the bacterial 16S rRNA genes and fluorescent in situ hybridization placed these symbionts in two separate clades in the class Gammaproteobacteria. We also conducted a broad phylogenetic analysis of the herein-reported DNA sequences as well as others from bacterial symbionts reported elsewhere in the literature, including alphaproteobacterial symbionts from the leech genus Placobdella as well as Aeromonas veronii from the medicinal leech, Hirudo medicinalis, and a Rickettsia sp. detected in Hemiclepsis marginata. Combined, these results indicate that blood-feeding leeches have forged bacterial partnerships at least five times during their evolutionary history.}, }
@article {pmid16118665, year = {2005}, author = {Ren, Q and Paulsen, IT}, title = {Comparative analyses of fundamental differences in membrane transport capabilities in prokaryotes and eukaryotes.}, journal = {PLoS computational biology}, volume = {1}, number = {3}, pages = {e27}, pmid = {16118665}, issn = {1553-734X}, mesh = {Biological Transport ; Computational Biology ; Eukaryotic Cells/classification/*metabolism ; Genome/genetics ; Membrane Transport Proteins/classification/genetics/*metabolism ; Phylogeny ; Prokaryotic Cells/classification/*metabolism ; Substrate Specificity ; }, abstract = {Whole-genome transporter analyses have been conducted on 141 organisms whose complete genome sequences are available. For each organism, the complete set of membrane transport systems was identified with predicted functions, and classified into protein families based on the transporter classification system. Organisms with larger genome sizes generally possessed a relatively greater number of transport systems. In prokaryotes and unicellular eukaryotes, the significant factor in the increase in transporter content with genome size was a greater diversity of transporter types. In contrast, in multicellular eukaryotes, greater number of paralogs in specific transporter families was the more important factor in the increase in transporter content with genome size. Both eukaryotic and prokaryotic intracellular pathogens and endosymbionts exhibited markedly limited transport capabilities. Hierarchical clustering of phylogenetic profiles of transporter families, derived from the presence or absence of a certain transporter family, showed that clustering patterns of organisms were correlated to both their evolutionary history and their overall physiology and lifestyles.}, }
@article {pmid16118664, year = {2005}, author = {Latorre, A and Gil, R and Silva, FJ and Moya, A}, title = {Chromosomal stasis versus plasmid plasticity in aphid endosymbiont Buchnera aphidicola.}, journal = {Heredity}, volume = {95}, number = {5}, pages = {339-347}, doi = {10.1038/sj.hdy.6800716}, pmid = {16118664}, issn = {0018-067X}, mesh = {Animals ; Aphids/*genetics ; Buchnera/enzymology/*genetics ; Chromosomes, Bacterial/*genetics ; Evolution, Molecular ; Leucine/genetics ; Multigene Family ; Phylogeny ; Plasmids/*genetics ; *Symbiosis ; Tryptophan/genetics ; }, abstract = {The study of three genomes of the aphid endosymbiont Buchnera aphidicola has revealed an extraordinary stasis: conservation of gene order and genetic composition of the chromosome, while the chromosome size and number of genes has reduced. The reduction in genome size appears to be ongoing since some lineages we now know to have even smaller chromosomes than the first B. aphidicola analysed. The current sequencing by our group of one of these smaller genomes with an estimated size of 450 kb, and its comparison with the other three available genomes provide insights into the nature of processes involved in shrinkage. We discuss whether B. aphidicola might be driven to extinction and be replaced by secondary aphid endosymbionts. In some lineages, genes encoding key enzymes in the pathways leading to tryptophan and leucine biosynthesis (trpEG and leuABCD, respectively) are located on plasmids, rather than the main chromosome. In contrast to the stasis of the main chromosome, plasmid genes have frequently been transferred to the main chromosome and undergone other gene rearrangements. We propose a two-step scenario to explain these contrasting modes of evolution. Essential genes may have escaped regulation by moving to plasmids in a moving B. aphidicola ancestor. B. aphidicola became polyploidy at a given stage of its evolution and plasmid genes have been transferred to the main chromosome through several independent events.}, }
@article {pmid16109488, year = {2005}, author = {Martin, W}, title = {The missing link between hydrogenosomes and mitochondria.}, journal = {Trends in microbiology}, volume = {13}, number = {10}, pages = {457-459}, doi = {10.1016/j.tim.2005.08.005}, pmid = {16109488}, issn = {0966-842X}, mesh = {Animals ; *Biological Evolution ; Ciliophora/metabolism/*ultrastructure ; Hydrogen/*metabolism ; Mitochondria/genetics/physiology ; Organelles/*genetics/*physiology ; }, abstract = {Mitochondria typically respire oxygen and possess a small DNA genome. But among various groups of oxygen-shunning eukaryotes, typical mitochondria are often lacking, organelles called hydrogenosomes being found instead. Like mitochondria, hydrogenosomes are surrounded by a double-membrane, produce ATP and sometimes even have cristae. In contrast to mitochondria, hydrogenosomes produce molecular hydrogen through fermentations, lack cytochromes and usually lack DNA. Hydrogenosomes do not fit into the conceptual mold cast by the classical endosymbiont hypothesis about the nature of mitochondria. Accordingly, ideas about their evolutionary origins have focussed on the differences between the two organelles instead of their commonalities. Are hydrogenosomes fundamentally different from mitochondria, the result of a different endosymbiosis? Or are our concepts about the mitochondrial archetype simply too narrow? A new report has uncovered DNA in the hydrogenosomes of anaerobic ciliates. The sequences show that these hydrogenosomes are, without a doubt, mitochondria in the evolutionary sense, even though they differ from typical mitochondria in various biochemical properties. The new findings are a benchmark for our understanding of hydrogenosome origins.}, }
@article {pmid16106260, year = {2005}, author = {Sasaki, T and Massaki, N and Kubo, T}, title = {Wolbachia variant that induces two distinct reproductive phenotypes in different hosts.}, journal = {Heredity}, volume = {95}, number = {5}, pages = {389-393}, doi = {10.1038/sj.hdy.6800737}, pmid = {16106260}, issn = {0018-067X}, mesh = {Animals ; Crosses, Genetic ; Female ; *Genetic Variation ; Gram-Negative Bacterial Infections ; Host-Parasite Interactions/*genetics ; Male ; Moths/genetics/parasitology ; Ovary/parasitology ; Phenotype ; Polymerase Chain Reaction ; Symbiosis/genetics ; Tetracycline/pharmacology ; Wolbachia/*genetics/pathogenicity ; }, abstract = {Wolbachia is an intracellular endosymbiont that induces a variety of reproductive alterations in diverse arthropods. The almond moth, Cadra cautella, is double infected with two Wolbachia variants, wCauA and wCauB, and expresses complete cytoplasmic incompatibility (CI). The individual contribution of wCauA and wCauB to the expression of CI are unclear, however, because the two variants have not been separated in this host. The effect of wCauA is of particular interest because it induces male killing when transferred into the Mediterranean flour moth, Ephestia kuehniella. In the present study, we generated C. cautella infected with only wCauA by treating double-infected insects with tetracycline. Single-infected C. cautella exhibited strong CI, demonstrating that wCauA induces two distinct reproductive phenotypes in different hosts: CI in C. cautella and male killing in E. kuehniella. CI was also observed in the cross of double-infected males and single-infected females. Comparison of the single- and double-infected insects by real-time quantitative polymerase chain reaction suggested that the wCauA density is not affected much by the presence or absence of wCauB.}, }
@article {pmid16104860, year = {2005}, author = {Goffredi, SK and Orphan, VJ and Rouse, GW and Jahnke, L and Embaye, T and Turk, K and Lee, R and Vrijenhoek, RC}, title = {Evolutionary innovation: a bone-eating marine symbiosis.}, journal = {Environmental microbiology}, volume = {7}, number = {9}, pages = {1369-1378}, doi = {10.1111/j.1462-2920.2005.00824.x}, pmid = {16104860}, issn = {1462-2912}, mesh = {Animals ; Biodegradation, Environmental ; *Biological Evolution ; Bone and Bones/*chemistry/microbiology ; DNA/genetics ; Fatty Acids/analysis ; Microscopy, Electron ; Oceanospirillaceae/genetics/*growth &amp; development/ultrastructure ; Pacific Ocean ; Phylogeny ; Polychaeta/genetics/*growth &amp; development/ultrastructure ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Whales ; }, abstract = {Symbiotic associations between microbes and invertebrates have resulted in some of the most unusual physiological and morphological adaptations that have evolved in the animal world. We document a new symbiosis between marine polychaetes of the genus Osedax and members of the bacterial group Oceanospirillales, known for heterotrophic degradation of complex organic compounds. These organisms were discovered living on the carcass of a grey whale at 2891 m depth in Monterey Canyon, off the coast of California. The mouthless and gutless worms are unique in their morphological specializations used to obtain nutrition from decomposing mammalian bones. Adult worms possess elaborate posterior root-like extensions that invade whale bone and contain bacteriocytes that house intracellular symbionts. Stable isotopes and fatty acid analyses suggest that these unusual endosymbionts are likely responsible for the nutrition of this locally abundant and reproductively prolific deep-sea worm.}, }
@article {pmid16103603, year = {2005}, author = {Plichart, C and Legrand, AM}, title = {Detection and characterization of Wolbachia infections in Wuchereria bancrofti (Spirurida: Onchocercidae) var. pacifica and Aedes (Stegomyia) polynesiensis (Diptera: Culicidae).}, journal = {The American journal of tropical medicine and hygiene}, volume = {73}, number = {2}, pages = {354-358}, pmid = {16103603}, issn = {0002-9637}, mesh = {Aedes/*microbiology/parasitology ; Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; Filariasis/parasitology/transmission ; Microfilariae/microbiology ; Molecular Sequence Data ; Pest Control, Biological ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/classification/genetics/growth &amp; development/*isolation &amp; purification ; Wuchereria bancrofti/*microbiology ; }, abstract = {Despite control programs based on mass drug administration (MDA) of microfilaricidal compounds, Bancroftian lymphatic filariasis remains a problem in French Polynesia. For an alternative strategy to MDA, we investigated the potential role of Wolbachia to control filarial transmission. Wolbachia are intracellular alpha-proteobacteria endosymbionts that infect a broad range of insects and nematodes. These bacteria have a suspected role in the pathogenesis of filariasis. They also may be useful in mosquito control through cytoplasmic incompatibility. To detect and characterize these bacteria in the filarial and mosquito-vectors in French Polynesia, a survey was conducted on field-collected mosquitoes and microfilariae from infected people. Samples were analyzed by a polymerase chain reaction and gene sequencing. The results indicate that these bacteria are widespread. Sequence analysis of the wsp and ftsZ genes positioned the Aedes polynesiensis Wolbachia in cluster A and Wuchereria bancrofti var. pacifica Wolbachia in cluster D. The implications for possible improved treatment and vector control are discussed.}, }
@article {pmid16103005, year = {2005}, author = {Gunawardena, NK and Fujimaki, Y and Aoki, Y and Mishima, N and Ezaki, T and Uni, S and Kimura, E}, title = {Differential effects of diethylcarbamazine, tetracycline and the combination on Brugia pahangi adult females in vitro.}, journal = {Parasitology international}, volume = {54}, number = {4}, pages = {253-259}, doi = {10.1016/j.parint.2005.06.005}, pmid = {16103005}, issn = {1383-5769}, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage/*pharmacology ; Brugia pahangi/*drug effects/embryology/microbiology/physiology ; Culture Media ; Diethylcarbamazine/administration &amp; dosage/*pharmacology ; Drug Therapy, Combination ; Female ; Filaricides/administration &amp; dosage/*pharmacology ; Microfilariae/drug effects/microbiology ; Parasitic Sensitivity Tests ; Symbiosis ; Tetracycline/administration &amp; dosage/*pharmacology ; Wolbachia/drug effects ; }, abstract = {Anti-filarial effects of diethylcarbamazine (DEC), tetracycline (TC) and the combination on Brugia pahangi adult females were studied in 7-day cell-free culture, in terms of microfilaria release, parasite motility, MTT assay for parasite viability and embryogram. TC 50 microg/ml (TC50) effectively reduced microfilaria release from day 1 of culture. Combined with DEC 100 microg/ml (DEC100) or DEC 500 microg/ml (DEC500), microfilaria release reduced further and synergistically. TC50 also reduced motility, but DEC100 and DEC500 did not. The combination of TC50 and DEC500 reduced motility synergistically. The MTT assay supported the results of motility study in general. The embryogram showed that only DEC500 reduced the total number of intrauterine embryos, especially ova, indicating that DEC500 inhibited early embryogenesis. TC50 did not affect the total number of embryos, but resulted in apparent accumulation of microfilariae in the uterus, suggesting that the drug inhibited release of microfilariae in this in vitro system. These results clarified different anti-female mechanisms between DEC and TC. A PCR-based study showed that endosymbiont bacteria, Wolbachia, in B. pahangi females decreased significantly after TC treatment. However, this study could not determine whether the effects of TC were direct or Wolbachia-mediated.}, }
@article {pmid16096092, year = {2005}, author = {Gwynn, DM and Callaghan, A and Gorham, J and Walters, KF and Fellowes, MD}, title = {Resistance is costly: trade-offs between immunity, fecundity and survival in the pea aphid.}, journal = {Proceedings. Biological sciences}, volume = {272}, number = {1574}, pages = {1803-1808}, pmid = {16096092}, issn = {0962-8452}, mesh = {Analysis of Variance ; Animals ; Aphids/*immunology/*parasitology ; Body Composition ; Body Size ; England ; Fertility/physiology ; Host-Parasite Interactions ; Random Amplified Polymorphic DNA Technique ; Survival Analysis ; *Wasps ; }, abstract = {Parasitoids are among the most important natural enemies of insects in many environments. Acyrthosiphon pisum, the pea aphid, is a common pest of the leguminous crops in temperate regions. Pea aphids are frequently attacked by a range of endoparasitic wasps, including the common aphidiine, Aphidius ervi. Immunity to parasitoid attack is thought to involve secondary symbiotic bacteria, the presence of which is associated with the death of the parasitoid egg. It has been suggested that there is a fecundity cost of resistance, as individuals carrying the secondary symbionts associated with parasitoid resistance have fewer offspring. Supporting this hypothesis, we find a positive relationship between fecundity and susceptibility to parasitoid attack. There is also a negative relationship between fecundity and off-plant survival time (which positively correlates with resistance to parasitoid attack). Taken together, these results suggest that the aphids can either invest in defence (parasitoid resistance, increased off-plant survival time) or reproduction, and speculate that this may be mediated by changes in the aphids' endosymbiont fauna. Furthermore, there is a positive relationship between aphid size and resistance, suggesting that successful resistance to parasitoid attack may involve physical, as well as physiological, defences.}, }
@article {pmid16093570, year = {2005}, author = {Oborník, M and Green, BR}, title = {Mosaic origin of the heme biosynthesis pathway in photosynthetic eukaryotes.}, journal = {Molecular biology and evolution}, volume = {22}, number = {12}, pages = {2343-2353}, doi = {10.1093/molbev/msi230}, pmid = {16093570}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Chlorophyta/genetics/metabolism ; Diatoms/genetics/metabolism ; Eukaryotic Cells/metabolism ; *Evolution, Molecular ; Gene Transfer, Horizontal ; Heme/*biosynthesis/genetics ; Models, Genetic ; Photosynthesis/*genetics ; *Phylogeny ; Plastids ; Rhodophyta/genetics/metabolism ; Symbiosis ; }, abstract = {Heme biosynthesis represents one of the most essential metabolic pathways in living organisms, providing the precursors for cytochrome prosthetic groups, photosynthetic pigments, and vitamin B(12). Using genomic data, we have compared the heme pathway in the diatom Thalassiosira pseudonana and the red alga Cyanidioschyzon merolae to those of green algae and higher plants, as well as to those of heterotrophic eukaryotes (fungi, apicomplexans, and animals). Phylogenetic analyses showed the mosaic character of this pathway in photosynthetic eukaryotes. Although most of the algal and plant enzymes showed the expected plastid (cyanobacterial) origin, at least one of them (porphobilinogen deaminase) appears to have a mitochondrial (alpha-proteobacterial) origin. Another enzyme, glutamyl-tRNA synthase, obviously originated in the eukaryotic nucleus. Because all the plastid-targeted sequences consistently form a well-supported cluster, this suggests that genes were either transferred from the primary endosymbiont (cyanobacteria) to the primary host nucleus shortly after the primary endosymbiotic event or replaced with genes from other sources at an equally early time, i.e., before the formation of three primary plastid lineages. The one striking exception to this pattern is ferrochelatase, the enzyme catalyzing the first committed step to heme and bilin pigments. In this case, two red algal sequences do not cluster either with the other plastid sequences or with cyanobacterial sequences and appear to have a proteobacterial origin like that of the apicomplexan parasites Plasmodium and Toxoplasma. Although the heterokonts also acquired their plastid via secondary endosymbiosis from a red alga, the diatom has a typical plastid-cyanobacterial ferrochelatase. We have not found any remnants of the plastidlike heme pathway in the nonphotosynthetic heterokonts Phytophthora ramorum and Phytophthora sojae.}, }
@article {pmid16092527, year = {2005}, author = {Lister, R and Hulett, JM and Lithgow, T and Whelan, J}, title = {Protein import into mitochondria: origins and functions today (review).}, journal = {Molecular membrane biology}, volume = {22}, number = {1-2}, pages = {87-100}, doi = {10.1080/09687860500041247}, pmid = {16092527}, issn = {0968-7688}, mesh = {Bacterial Physiological Phenomena ; Bacterial Proteins/metabolism ; *Evolution, Molecular ; Fungal Proteins/metabolism ; Membrane Proteins/physiology ; Membrane Transport Proteins/*physiology ; Mitochondria/*metabolism ; Mitochondrial Proteins/*metabolism ; Protein Transport ; Yeasts/physiology ; }, abstract = {Mitochondria are organelles derived from alpha-proteobacteria over the course of one to two billion years. Mitochondria from the major eukaryotic lineages display some variation in functions and coding capacity but sequence analysis demonstrates them to be derived from a single common ancestral endosymbiont. The loss of assorted functions, the transfer of genes to the nucleus, and the acquisition of various 'eukaryotic' proteins have resulted in an organelle that contains approximately 1000 different proteins, with most of these proteins imported into the organelle across one or two membranes. A single translocase in the outer membrane and two translocases in the inner membrane mediate protein import. Comparative sequence analysis and functional complementation experiments suggest some components of the import pathways to be directly derived from the eubacterial endosymbiont's own proteins, and some to have arisen 'de novo' at the earliest stages of 'mitochondrification' of the endosymbiont. A third class of components appears lineage-specific, suggesting they were incorporated into the process of protein import long after mitochondria was established as an organelle and after the divergence of the various eukaryotic lineages. Protein sorting pathways inherited from the endosymbiont have been co-opted and play roles in intraorganelle protein sorting after import. The import apparatus of animals and fungi show significant similarity to one another, but vary considerably to the plant apparatus. Increasing complexity in the eukaryotic lineage, i.e., from single celled to multi-cellular life forms, has been accompanied by an expansion in genes encoding each component, resulting in small gene families encoding many components. The functional differences in these gene families remain to be elucidated, but point to a mosaic import apparatus that can be regulated by a variety of signals.}, }
@article {pmid16092526, year = {2005}, author = {Reumann, S and Inoue, K and Keegstra, K}, title = {Evolution of the general protein import pathway of plastids (review).}, journal = {Molecular membrane biology}, volume = {22}, number = {1-2}, pages = {73-86}, doi = {10.1080/09687860500041916}, pmid = {16092526}, issn = {0968-7688}, mesh = {Active Transport, Cell Nucleus ; Bacterial Proteins/metabolism ; Cell Nucleus ; Cyanobacteria/physiology ; *Evolution, Molecular ; Membrane Proteins/classification/physiology ; Membrane Transport Proteins/classification/*physiology ; Phylogeny ; Plant Proteins/metabolism ; Plastids/*metabolism ; *Protein Transport ; Rhodophyta/physiology ; }, abstract = {The evolutionary process that transformed a cyanobacterial endosymbiont into contemporary plastids involved not only inheritance but also invention. Because gram-negative bacteria lack a system for polypeptide import, the envelope translocon complex of the general protein import pathway was the most important invention of organelle evolution resulting in a pathway to import back into plastids those nuclear-encoded proteins supplemented with a transit peptide. Genome information of cyanobacteria, phylogenetically diverse plastids, and the nuclei of the first red alga, a diatom, and Arabidopsis thaliana allows us to trace back the evolutionary origin of the twelve currently known translocon components and to partly deduce their assembly sequence. Development of the envelope translocon was initiated by recruitment of a cyanobacterial homolog of the protein-import channel Toc75, which belongs to a ubiquitous and essential family of Omp85/D15 outer membrane proteins of gram-negative bacteria that mediate biogenesis of beta-barrel proteins. Likewise, three other translocon subunits (Tic20, Tic22, and Tic55) and several stromal chaperones have been inherited from the ancestral cyanobacterium and modified to take over the novel function of precursor import. Most of the remaining subunits seem to be of eukaryotic origin, recruited from pre-existing nuclear genes. The next subunits that joined the evolving protein import complex likely were Toc34 and Tic110, as indicated by the presence of homologous genes in the red alga Cyanidioschyzon merolae, followed by the stromal processing peptidase, members of the Toc159 receptor family, Toc64, Tic40, and finally some regulatory redox components (Tic62, Tic32), all of which were probably required to increase specificity and efficiency of precursor import.}, }
@article {pmid16088356, year = {2005}, author = {Naganuma, T and Elsaied, HE and Hoshii, D and Kimura, H}, title = {Bacterial endosymbioses of gutless tube-dwelling worms in nonhydrothermal vent habitats.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {7}, number = {5}, pages = {416-428}, pmid = {16088356}, issn = {1436-2228}, mesh = {Animals ; Annelida/*classification/*microbiology/physiology ; Bacteria/*classification/growth &amp; development ; Biotechnology ; Environment ; Fossils ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Gutless tube-dwelling worms of pogonophorans (also known as frenulates) and vestimentiferans depend on primary production of endosymbiotic bacteria. The endosymbionts include thiotrophs that oxidize sulfur for autotrophic production and methanotrophs that oxidize and assimilate methane. Although most of the pogonophoran and vestimentiferan tube worms possess single thiotrophic 16S rRNA genes (16S rDNA) related to gamma-proteobacteria, some pogonohorans are known to bear single methanotroph species or even dual symbionts of thiotrophs and methanotrophs. The vestimentiferan Lamellibrachia sp. L1 shows symbiotic 16S rDNA sequences of alpha-, beta-, gamma-, and epsilon-proteobacteria, varying among specimens, with RuBisCO form II gene (cbbM) sequences related to beta-proteobacteria. An unidentified pogonophoran from the world's deepest cold seep, 7326-m deep in the Japan Trench, hosts a symbiotic thiotroph based on 16S rDNA with the RuBisCO form I gene (cbbL). In contrast, a shallow-water pogonophoran (Oligobrachia mashikoi) in coastal Japan Sea has a methanotrophic 16S rDNA and thiotrophic cbbL, which may suggest the feature of type X methanotrophs. These observations demonstrate that pogonophoran and vestimentiferan worms have higher plasticity in bacterial symbioses than previously suspected.}, }
@article {pmid16077009, year = {2005}, author = {Degnan, PH and Lazarus, AB and Wernegreen, JJ}, title = {Genome sequence of Blochmannia pennsylvanicus indicates parallel evolutionary trends among bacterial mutualists of insects.}, journal = {Genome research}, volume = {15}, number = {8}, pages = {1023-1033}, pmid = {16077009}, issn = {1088-9051}, support = {R01 GM062626/GM/NIGMS NIH HHS/United States ; R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Amino Acid Substitution ; Animals ; Base Sequence ; Conserved Sequence ; DNA, Intergenic ; Enterobacteriaceae/*genetics/metabolism/physiology ; *Evolution, Molecular ; Gene Deletion ; Genetic Variation ; *Genome, Bacterial ; Insecta/*microbiology ; Molecular Sequence Data ; *Mutation ; Polymorphism, Genetic ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; }, abstract = {The distinct lifestyle of obligately intracellular bacteria can alter fundamental forces that drive and constrain genome change. In this study, sequencing the 792-kb genome of Blochmannia pennsylvanicus, an obligate endosymbiont of Camponotus pennsylvanicus, enabled us to trace evolutionary changes that occurred in the context of a bacterial-ant association. Comparison to the genome of Blochmannia floridanus reveals differential loss of genes involved in cofactor biosynthesis, the composition and structure of the cell wall and membrane, gene regulation, and DNA replication. However, the two Blochmannia species show complete conservation in the order and strand orientation of shared genes. This finding of extreme stasis in genome architecture, also reported previously for the aphid endosymbiont Buchnera, suggests that genome stability characterizes long-term bacterial mutualists of insects and constrains their evolutionary potential. Genome-wide analyses of protein divergences reveal 10- to 50-fold faster amino acid substitution rates in Blochmannia compared to related bacteria. Despite these varying features of genome evolution, a striking correlation in the relative divergences of proteins indicates parallel functional constraints on gene functions across ecologically distinct bacterial groups. Furthermore, the increased rates of amino acid substitution and gene loss in Blochmannia have occurred in a lineage-specific fashion, which may reflect life history differences of their ant hosts.}, }
@article {pmid16060695, year = {2005}, author = {Das, S and Pan, A and Paul, S and Dutta, C}, title = {Comparative analyses of codon and amino acid usage in symbiotic island and core genome in nitrogen-fixing symbiotic bacterium Bradyrhizobium japonicum.}, journal = {Journal of biomolecular structure &amp; dynamics}, volume = {23}, number = {2}, pages = {221-232}, doi = {10.1080/07391102.2005.10507061}, pmid = {16060695}, issn = {0739-1102}, mesh = {Amino Acids/*chemistry ; Bradyrhizobium/*genetics ; Codon/*chemistry/*genetics ; Genome, Bacterial ; Nitrogen/*metabolism ; *Symbiosis ; }, abstract = {Genes involved in the symbiotic interactions between the nitrogen-fixing endosymbiont Bradyrhizobium japonicum, and its leguminous host are mostly clustered in a symbiotic island (SI), acquired by the bacterium through a process of horizontal transfer. A comparative analysis of the codon and amino acid usage in core and SI genes/proteins of B. japonicum has been carried out in the present study. The mutational bias, translational selection, and gene length are found to be the major sources of variation in synonymous codon usage in the core genome as well as in SI, the strength of translational selection being higher in core genes than in SI. In core proteins, hydrophobicity is the main source of variation in amino acid usage, expressivity and aromaticity being the second and third important sources. But in SI proteins, aromaticity is the chief source of variation, followed by expressivity and hydrophobicity. In SI proteins, both the mean molecular weight and mean aromaticity of individual proteins exhibit significant positive correlation with gene expressivity, which violate the cost-minimization hypothesis. Investigation of nucleotide substitution patterns in B. japonicum and Mesorhizobium loti orthologous genes reveals that both synonymous and non-synonymous sites of highly expressed genes are more conserved than their lowly expressed counterparts and this conservation is more pronounced in the genes present in core genome than in SI.}, }
@article {pmid16054816, year = {2005}, author = {Stewart, FJ and Newton, IL and Cavanaugh, CM}, title = {Chemosynthetic endosymbioses: adaptations to oxic-anoxic interfaces.}, journal = {Trends in microbiology}, volume = {13}, number = {9}, pages = {439-448}, doi = {10.1016/j.tim.2005.07.007}, pmid = {16054816}, issn = {0966-842X}, mesh = {*Adaptation, Physiological ; Bacteria/*metabolism ; *Bacterial Physiological Phenomena ; Energy Metabolism ; Eukaryotic Cells/*microbiology ; Methane/metabolism ; Sulfur/metabolism ; Symbiosis/*physiology ; }, abstract = {Chemosynthetic endosymbioses occur ubiquitously at oxic-anoxic interfaces in marine environments. In these mutualisms, bacteria living directly within the cell of a eukaryotic host oxidize reduced chemicals (sulfur or methane), fueling their own energetic and biosynthetic needs, in addition to those of their host. In habitats such as deep-sea hydrothermal vents, chemosynthetic symbioses dominate the biomass, contributing substantially to primary production. Although these symbionts have yet to be cultured, physiological, biochemical and molecular approaches have provided insights into symbiont genetics and metabolism, as well as into symbiont-host interactions, adaptations and ecology. Recent studies of endosymbiont biology are reviewed, with emphasis on a conceptual model of thioautotrophic metabolism and studies linking symbiont physiology with the geochemical environment. We also discuss current and future research directions, focusing on the use of genome analyses to reveal mechanisms that initiate and sustain the symbiont-host interaction.}, }
@article {pmid16044198, year = {2005}, author = {Ishida, K}, title = {Protein targeting into plastids: a key to understanding the symbiogenetic acquisitions of plastids.}, journal = {Journal of plant research}, volume = {118}, number = {4}, pages = {237-245}, pmid = {16044198}, issn = {0918-9440}, mesh = {Biological Evolution ; Plant Proteins/*metabolism ; Plastids/*metabolism ; *Symbiosis ; }, abstract = {Recent progress in molecular phylogenetics has proven that photosynthetic eukaryotes acquired plastids via primary and secondary endosymbiosis and has given us information about the origin of each plastid. How a photosynthetic endosymbiont became a plastid in each group is, however, poorly understood, especially for the organisms with secondary plastids. Investigating how a nuclear-encoded plastid protein is targeted into a plastid in each photosynthetic group is one of the most important keys to understanding the evolutionary process of symbiogenetic plastid acquisition and its diversity. For organisms which originated through primary endosymbiosis, protein targeting into plastids has been well studied at the molecular level. For organisms which originated through secondary endosymbiosis, molecular-level studies have just started on the plastid-targeted protein-precursor sequences and the targeting pathways of the precursors. However, little information is available about how the proteins get across the inner two or three envelope membranes in organisms with secondary plastids. A good in vitro protein-import system for isolated plastids and a cell transformation system must be established for each group of photosynthetic eukaryotes in order to understand the mechanisms, the evolutionary processes and the diversity of symbiogenetic plastid acquisitions in photosynthetic eukaryotes.}, }
@article {pmid16040811, year = {2005}, author = {Dolezal, P and Smíd, O and Rada, P and Zubácová, Z and Bursać, D and Suták, R and Nebesárová, J and Lithgow, T and Tachezy, J}, title = {Giardia mitosomes and trichomonad hydrogenosomes share a common mode of protein targeting.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {102}, number = {31}, pages = {10924-10929}, pmid = {16040811}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Biological Transport, Active ; Evolution, Molecular ; Ferredoxins/genetics/metabolism ; Giardia lamblia/genetics/*metabolism/ultrastructure ; Iron-Sulfur Proteins/genetics/metabolism ; Molecular Sequence Data ; Organelles/metabolism ; Protein Processing, Post-Translational ; Protozoan Proteins/genetics/*metabolism ; Recombinant Proteins/genetics/metabolism ; Trichomonas vaginalis/genetics/*metabolism/ultrastructure ; }, abstract = {Mitochondria are archetypal organelles of endosymbiotic origin in eukaryotic cells. Some unicellular eukaryotes (protists) were considered to be primarily amitochondrial organisms that diverged from the eukaryotic lineage before the acquisition of the premitochondrial endosymbiont, but their amitochondrial status was recently challenged by the discovery of mitochondria-like double membrane-bound organelles called mitosomes. Here, we report that proteins targeted into mitosomes of Giardia intestinalis have targeting signals necessary and sufficient to be recognized by the mitosomal protein import machinery. Expression of these mitosomal proteins in Trichomonas vaginalis results in targeting to hydrogenosomes, a hydrogen-producing form of mitochondria. We identify, in Giardia and Trichomonas, proteins related to the component of the translocase in the inner membrane from mitochondria and the processing peptidase. A shared mode of protein targeting supports the hypothesis that mitosomes, hydrogenosomes, and mitochondria represent different forms of the same fundamental organelle having evolved under distinct selection pressures.}, }
@article {pmid16039807, year = {2005}, author = {Fry, AJ and Wernegreen, JJ}, title = {The roles of positive and negative selection in the molecular evolution of insect endosymbionts.}, journal = {Gene}, volume = {355}, number = {}, pages = {1-10}, doi = {10.1016/j.gene.2005.05.021}, pmid = {16039807}, issn = {0378-1119}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/*microbiology ; Bacterial Proteins/genetics ; Bacterial Proton-Translocating ATPases/genetics ; Chaperonin 60/genetics ; Codon/genetics ; *Evolution, Molecular ; Genetic Variation ; Models, Genetic ; Phylogeny ; Proteobacteria/classification/*genetics ; Ribosomal Proteins/genetics ; *Selection, Genetic ; }, abstract = {The evolutionary rate acceleration observed in most endosymbiotic bacteria may be explained by higher mutation rates, changes in selective pressure, and increased fixation of deleterious mutations by genetic drift. Here, we explore the forces influencing molecular evolution in Blochmannia, an obligate endosymbiont of Camponotus and related ant genera. Our goals were to compare rates of sequence evolution in Blochmannia with related bacteria, to explore variation in the strength and efficacy of negative (purifying) selection, and to evaluate the effect of positive selection. For six Blochmannia pairs, plus Buchnera and related enterobacteria, estimates of sequence divergence at four genes confirm faster rates of synonymous evolution in the ant mutualist. This conclusion is based on higher dS between Blochmannia lineages despite their more recent divergence. Likewise, generally higher dN in Blochmannia indicates faster rates of nonsynonymous substitution in this group. One exception is the groEL gene, for which lower dN and dN/dS compared to Buchnera indicate exceptionally strong negative selection in Blochmannia. In addition, we explored evidence for positive selection in Blochmannia using both site-and lineage-based maximum likelihood models. These approaches confirmed heterogeneity of dN/dS among codon sites and revealed significant variation in dN/dS across Blochmannia lineages for three genes. Lineage variation affected genes independently, with no evidence of parallel changes in dN/dS across genes along a given branch. Our data also reveal instances of dN/dS greater than one; however, we do not interpret these large dN/dS ratios as evidence for positive selection. In sum, while drift may contribute to an overall rate acceleration at nonsynonymous sites in Blochmannia, variable selective pressures best explain the apparent gene-specific changes in dN/dS across lineages of this ant mutualist. In the course of this study, we reanalyzed variation at Buchnera groEL and found no evidence of positive selection that was previously reported.}, }
@article {pmid16037215, year = {2005}, author = {Williams, BA and Slamovits, CH and Patron, NJ and Fast, NM and Keeling, PJ}, title = {A high frequency of overlapping gene expression in compacted eukaryotic genomes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {102}, number = {31}, pages = {10936-10941}, pmid = {16037215}, issn = {0027-8424}, mesh = {Animals ; Base Sequence ; Cryptophyta/genetics ; DNA, Algal/genetics ; DNA, Complementary/genetics ; DNA, Protozoan/genetics ; Eukaryotic Cells ; *Evolution, Molecular ; Expressed Sequence Tags ; *Gene Expression ; *Genome ; Microsporidia/genetics ; Models, Genetic ; Molecular Sequence Data ; RNA, Algal/genetics ; RNA, Messenger/genetics ; RNA, Protozoan/genetics ; }, abstract = {The gene density of eukaryotic nuclear genomes is generally low relative to prokaryotes, but several eukaryotic lineages (many parasites or endosymbionts) have independently evolved highly compacted, gene-dense genomes. The best studied of these are the microsporidia, highly adapted fungal parasites, and the nucleomorphs, relict nuclei of endosymbiotic algae found in cryptomonads and chlorarachniophytes. These systems are now models for the effects of compaction on the form and dynamics of the nuclear genome. Here we report a large-scale investigation of gene expression from compacted eukaryotic genomes. We have conducted EST surveys of the microsporidian Antonospora locustae and nucleomorphs of the cryptomonad Guillardia theta and the chlorarachniophyte Bigelowiella natans. In all three systems we find a high frequency of mRNA molecules that encode sequence from more than one gene. There is no bias for these genes to be on the same strand, so it is unlikely that these mRNAs represent operons. Instead, compaction appears to have reduced the intergenic regions to such an extent that control elements like promoters and terminators have been forced into or beyond adjacent genes, resulting in long untranslated regions that encode other genes. Normally, transcriptional overlap can interfere with expression of a gene, but these genomes cope with high frequencies of overlap and with termination signals within expressed genes. These findings also point to serious practical difficulties in studying expression in compacted genomes, because many techniques, such as arrays or serial analysis of gene expression will be misleading.}, }
@article {pmid16020724, year = {2005}, author = {El-Sayed, NM and Myler, PJ and Blandin, G and Berriman, M and Crabtree, J and Aggarwal, G and Caler, E and Renauld, H and Worthey, EA and Hertz-Fowler, C and Ghedin, E and Peacock, C and Bartholomeu, DC and Haas, BJ and Tran, AN and Wortman, JR and Alsmark, UC and Angiuoli, S and Anupama, A and Badger, J and Bringaud, F and Cadag, E and Carlton, JM and Cerqueira, GC and Creasy, T and Delcher, AL and Djikeng, A and Embley, TM and Hauser, C and Ivens, AC and Kummerfeld, SK and Pereira-Leal, JB and Nilsson, D and Peterson, J and Salzberg, SL and Shallom, J and Silva, JC and Sundaram, J and Westenberger, S and White, O and Melville, SE and Donelson, JE and Andersson, B and Stuart, KD and Hall, N}, title = {Comparative genomics of trypanosomatid parasitic protozoa.}, journal = {Science (New York, N.Y.)}, volume = {309}, number = {5733}, pages = {404-409}, doi = {10.1126/science.1112181}, pmid = {16020724}, issn = {1095-9203}, support = {AI45061/AI/NIAID NIH HHS/United States ; AI045039/AI/NIAID NIH HHS/United States ; U01 AI043062/AI/NIAID NIH HHS/United States ; U01 AI045039/AI/NIAID NIH HHS/United States ; AI45038/AI/NIAID NIH HHS/United States ; U01 AI045038/AI/NIAID NIH HHS/United States ; U01 AI040599/AI/NIAID NIH HHS/United States ; R01 AI043062/AI/NIAID NIH HHS/United States ; //Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Biological Evolution ; Chromosomes/genetics ; Evolution, Molecular ; Gene Transfer, Horizontal ; Genes, Protozoan ; *Genome, Protozoan ; Genomics ; Leishmania major/chemistry/*genetics/metabolism ; Molecular Sequence Data ; Multigene Family ; Mutation ; Phylogeny ; Plastids/genetics ; *Proteome ; Protozoan Proteins/chemistry/*genetics/physiology ; Recombination, Genetic ; Retroelements ; Species Specificity ; Symbiosis ; Synteny ; Telomere/genetics ; Trypanosoma brucei brucei/chemistry/*genetics/metabolism ; Trypanosoma cruzi/chemistry/*genetics/metabolism ; }, abstract = {A comparison of gene content and genome architecture of Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major, three related pathogens with different life cycles and disease pathology, revealed a conserved core proteome of about 6200 genes in large syntenic polycistronic gene clusters. Many species-specific genes, especially large surface antigen families, occur at nonsyntenic chromosome-internal and subtelomeric regions. Retroelements, structural RNAs, and gene family expansion are often associated with syntenic discontinuities that-along with gene divergence, acquisition and loss, and rearrangement within the syntenic regions-have shaped the genomes of each parasite. Contrary to recent reports, our analyses reveal no evidence that these species are descended from an ancestor that contained a photosynthetic endosymbiont.}, }
@article {pmid16014485, year = {2005}, author = {Everett, KDE and Thao, M and Horn, M and Dyszynski, GE and Baumann, P}, title = {Novel chlamydiae in whiteflies and scale insects: endosymbionts 'Candidatus Fritschea bemisiae' strain Falk and 'Candidatus Fritschea eriococci' strain Elm.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {55}, number = {Pt 4}, pages = {1581-1587}, doi = {10.1099/ijs.0.63454-0}, pmid = {16014485}, issn = {1466-5026}, mesh = {Animals ; Base Composition ; Chlamydiales/*classification/*genetics/isolation &amp; purification ; Hemiptera/*microbiology ; Microscopy, Electron ; Molecular Sequence Data ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; rRNA Operon ; }, abstract = {Bacteria called 'Fritschea' are endosymbionts of the plant-feeding whitefly Bemisia tabaci and scale insect Eriococcus spurius. In the gut of B. tabaci, these bacteria live within bacteriocyte cells that are transmitted directly from the parent to oocytes. Whiteflies cause serious economic damage to many agricultural crops; B. tabaci fecundity and host range are less than those of Bemisia argentifolii, possibly due to the presence of this endosymbiont. The B. tabaci endosymbiont has been characterized using electron microscopy and DNA analysis but has not been isolated or propagated outside of insects. The present study compared sequences for 11 endosymbiont genes to genomic data for chlamydial families Parachlamydiaceae, Chlamydiaceae and Simkaniaceae and to 16S rRNA gene signature sequences from 330 chlamydiae. We concluded that it was appropriate to propose 'Candidatus Fritschea bemisiae' strain Falk and 'Candidatus Fritschea eriococci' strain Elm as members of the family Simkaniaceae in the Chlamydiales.}, }
@article {pmid16005284, year = {2005}, author = {Brownlie, JC and O'Neill, SL}, title = {Wolbachia genomes: insights into an intracellular lifestyle.}, journal = {Current biology : CB}, volume = {15}, number = {13}, pages = {R507-9}, doi = {10.1016/j.cub.2005.06.029}, pmid = {16005284}, issn = {0960-9822}, mesh = {Animals ; Brugia malayi/genetics/*microbiology ; *Genome, Bacterial ; Heme/genetics ; *Phenotype ; Repetitive Sequences, Nucleic Acid/genetics ; Riboflavin/genetics ; Species Specificity ; Symbiosis/*genetics ; Wolbachia/*genetics/physiology ; }, abstract = {The genome sequence of the Wolbachia endosymbiont that infects the nematode Brugia malayi has recently been determined together with three partial Wolbachia genomes from different Drosophila species. These data along with the previously published Wolbachia genome from Drosophila melanogaster provide new insights into how this endosymbiont has managed to become so successful.}, }
@article {pmid16003470, year = {2005}, author = {Vannini, C and Petroni, G and Verni, F and Rosati, G}, title = {A bacterium belonging to the Rickettsiaceae family inhabits the cytoplasm of the marine ciliate Diophrys appendiculata (Ciliophora, Hypotrichia).}, journal = {Microbial ecology}, volume = {49}, number = {3}, pages = {434-442}, pmid = {16003470}, issn = {0095-3628}, mesh = {Animals ; Ciliophora/*microbiology ; Ecology ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; Rickettsiaceae/*growth &amp; development ; Seawater ; Symbiosis ; Water Microbiology ; }, abstract = {Bacteria of the family Rickettsiaceae (order Rickettsiales, alpha-Proteobacteria) are mainly known to be endosymbionts of arthropods with the capability to infect also vertebrate cells. Recently, they have also been found as leech endocytobionts. In the present paper, we report the first finding of a bacterium belonging to the family Rickettsiaceae in a natural population of a marine ciliate protozoan, namely Diophrys appendiculata, collected in the Baltic Sea. Bacteria were unambiguously identified through morphological characterization and the "full-cycle rRNA approach" (i.e., 16S rRNA gene characterization and use of specifically designed oligonucleotide probes for in situ detection). Symbionts are rod-shaped bacteria that grow freely in the cytoplasm of the host cell. They present two different morphotypes, similar in size, but different in cytoplasmic density. These are typical morphological features of members of the family Rickettsiaceae. 16S rRNA gene sequence showed that Diophrys symbionts share a high similarity value (>92%) with bacteria belonging to the genus Rickettsia. Phylogenetic analysis revealed that these new endosymbionts are clearly included in the clade of the family Rickettsiaceae, but they occupy an independent phylogenetic position with respect to members of the genus Rickettsia. This is the first report of a member of this family from a host protozoan and from a marine habitat. This result shows that this bacterial group is more diversified and widespread than supposed so far, and that its ecological relevance could until now have been underestimated. In light of these considerations, the two 16S rRNA oligonucleotide probes here presented, specific for members of the Rickettsiaceae, can represent useful tools for further researches on the presence and the spread of these microorganisms in the natural environment.}, }
@article {pmid16000242, year = {2005}, author = {Suzuki, Y and Sasaki, T and Suzuki, M and Tsuchida, S and Nealson, KH and Horikoshi, K}, title = {Molecular phylogenetic and isotopic evidence of two lineages of chemoautotrophic endosymbionts distinct at the subdivision level harbored in one host-animal type: the genus Alviniconcha (Gastropoda: Provannidae).}, journal = {FEMS microbiology letters}, volume = {249}, number = {1}, pages = {105-112}, doi = {10.1016/j.femsle.2005.06.023}, pmid = {16000242}, issn = {0378-1097}, mesh = {Animals ; Carbon Isotopes/metabolism ; DNA, Bacterial/analysis ; Fatty Acids/*analysis ; Gammaproteobacteria/chemistry/*classification/genetics/isolation &amp; purification ; Gills/microbiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Mollusca/*microbiology/ultrastructure ; Pacific Ocean ; *Phylogeny ; RNA, Ribosomal, 16S ; Seawater/microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The hydrothermal-vent gastropod Alviniconcha hessleri from the Alice Springs deep-sea hydrothermal field in the Mariana Back-Arc Basin in the Western Pacific houses an intracellular bacterial endosymbiont in its gill. Although enzymatic analysis has revealed that the endosymbiont is a sulfur-oxidizing chemoautotroph using the Calvin-Benson cycle for the fixation of carbon dioxide, the phylogenetic affiliation of, and the trophic relationship of A. hessleri with, the chemoautotrophic endosymbiont remains undetermined. A single 16S rRNA gene sequence was obtained from the DNA extract of the gill, and phylogenetic analysis placed the source organism within the lineage of the gamma subdivision of the Proteobacteria that consists of many chemoautotrophic endosymbionts of marine invertebrates. Fluorescence in situ hybridization analysis showed the bacterium densely colonizing the gill filaments. The fatty acid profile of the symbiont-free mantle contains the high level of the 16:1 fatty acid originating from the endosymbiont, which indicates that the endosymbiont cells are digested by, and incorporated into, the host. Compound-specific carbon isotopic analysis revealed that fatty acids from the gastropod tissues are all (13)C-depleted relative to the gastropod biomass. This fractionation pattern is consistent with chemoautotrophy based on the Calvin-Benson cycle and subsequent fatty-acid biosynthesis from (13)C-depleted acetyl coenzyme A. The results from the present study are clearly different from those from our previous study for A. aff. hessleri from the Indian Ocean that harbors a chemoautotrophic endosymbiont belonging to the epsilon subdivision of the Proteobacteria, which mediates the reductive tricarboxylic acid cycle for carbon fixation. Thus, it is concluded here that two lineages of chemoautotrophic bacteria, phylogenetically distinct at the subdivision level, occur as the primary endosymbiont in one host-animal type, which is unknown for the other metazoans.}, }
@article {pmid15997410, year = {2005}, author = {Müller, HA and Zahner, H}, title = {Lethal LPS-independent side effects after microfilaricidal treatment in Acanthocheilonema viteae-infected rodents.}, journal = {Parasitology research}, volume = {97}, number = {3}, pages = {201-208}, pmid = {15997410}, issn = {0932-0113}, mesh = {Animals ; Diethylcarbamazine/*adverse effects ; *Dipetalonema/immunology/isolation &amp; purification ; Dipetalonema Infections/*drug therapy/mortality/parasitology ; Disease Models, Animal ; Drug Therapy, Combination ; Female ; Filaricides/*adverse effects ; Gerbillinae ; Levamisole/*adverse effects ; *Lipopolysaccharides/metabolism ; Microfilariae/drug effects ; Muridae ; Parasitic Diseases, Animal/*drug therapy/mortality ; Rodent Diseases/drug therapy/parasitology ; Species Specificity ; Survival Rate ; Wolbachia/immunology ; }, abstract = {Mastomys coucha and jirds infected with Acanthocheilonema viteae, a filarial species free of endosymbiontic bacteria of the genus Wolbachia, suffer lethal side effects after effective microfilaricidal therapy with diethylcarbamazine and levamisole, whereas, M. coucha infected with the Wolbachia-infested species Brugia malayi or Litomosoides carinii tolerate corresponding treatment. Mortality in A. viteae infected, treated animals varied with microfilariae density in the blood. It was up to 100% in highly microfilaraemic M. coucha and jirds, but low or absent in animals with low microfilariae counts. Deaths occurred in most cases 5-24 h after treatment. Characteristic symptoms in animals, which died subsequently were a rapid drop in body temperature by 4-7 degrees C, an increase in hematokrit values by up to 10% and a moderate blood acidosis. Lethal effects in A. viteae infections did not depend on a particular status of hypersensitivity of the animals since desensitization procedures, which protected infected M. coucha against an otherwise lethal intravenous challenge with A. viteae homogenate did not protect against adverse reactions to a subsequent microfilaricidal treatment. The animals were protected from treatment induced death by injection of N-LMMA. Thus the final morbific agent seems NO. The data show that adverse effects after effective microfilaricidal therapy may be caused by microfilariae derived components different from Wolbachia-released LPS.}, }
@article {pmid15993645, year = {2005}, author = {Bullerwell, CE and Lang, BF}, title = {Fungal evolution: the case of the vanishing mitochondrion.}, journal = {Current opinion in microbiology}, volume = {8}, number = {4}, pages = {362-369}, doi = {10.1016/j.mib.2005.06.009}, pmid = {15993645}, issn = {1369-5274}, mesh = {DNA, Mitochondrial/genetics ; *Evolution, Molecular ; Fungi/*genetics ; Mitochondria/*genetics ; Mitochondrial Proteins/genetics ; Phylogeny ; }, abstract = {Mitochondria, the energy-producing organelles of the eukaryotic cell, are derived from an ancient endosymbiotic alpha-Proteobacterium. These organelles contain their own genetic system, a remnant of the endosymbiont's genome, which encodes only a fraction of the mitochondrial proteome. The majority of mitochondrial proteins are translated from nuclear genes and are imported into mitochondria. Recent studies of phylogenetically diverse representatives of Fungi reveal that their mitochondrial DNAs are among the most highly derived, encoding only a limited set of genes. Much of the reduction in the coding content of the mitochondrial genome probably occurred early in fungal evolution. Nevertheless, genome reduction is an ongoing process. Fungi in the chytridiomycete order Neocallimastigales and in the pathogenic Microsporidia have taken mitochondrial reduction to the extreme and have permanently lost a mitochondrial genome. These organisms have organelles derived from mitochondria that retain traces of their mitochondrial ancestry.}, }
@article {pmid15986921, year = {2005}, author = {Bright, LJ and Liang, Y and Mitchell, DM and Harris, JM}, title = {The LATD gene of Medicago truncatula is required for both nodule and root development.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {18}, number = {6}, pages = {521-532}, doi = {10.1094/MPMI-18-0521}, pmid = {15986921}, issn = {0894-0282}, support = {1 P20 RR16462/RR/NCRR NIH HHS/United States ; }, mesh = {Chromosome Mapping ; Chromosomes, Plant/genetics ; Genes, Plant/*genetics ; Medicago truncatula/*genetics/growth &amp; development/microbiology ; Mutation ; Phenotype ; Plant Roots/*genetics/growth &amp; development ; Rhizobium/growth &amp; development ; Symbiosis/genetics ; }, abstract = {The evolutionary origins of legume root nodules are largely unknown. We have identified a gene, LATD, of the model legume Medicago truncatula, that is required for both nodule and root development, suggesting that these two developmental processes may share a common evolutionary origin. The latd mutant plants initiate nodule formation but do not complete it, resulting in immature, non-nitrogen-fixing nodules. Similarly, lateral roots initiate, but remain short stumps. The primary root, which initially appears to be wild type, gradually ceases growth and forms an abnormal tip that resembles that of the mutant lateral roots. Infection by the rhizobial partner, Sinorhizobium meliloti, can occur, although infection is rarely completed. Once inside latd mutant nodules, S. meliloti fails to express rhizobial genes associated with the developmental transition from free-living bacterium to endosymbiont, such as bacA and nex38. The infecting rhizobia also fail to express nifH and fix nitrogen. Thus, both plant and bacterial development are blocked in latd mutant roots. Based on the latd mutant phenotype, we propose that the wild-type function of the LATD gene is to maintain root meristems. The strong requirement of both nodules and lateral roots for wild-type LATD gene function supports lateral roots as a possible evolutionary origin for legume nodules.}, }
@article {pmid15977799, year = {2005}, author = {Gamaleĭ, IuV}, title = {[The role of plastids and assimilate transport system in the control of plant development].}, journal = {Ontogenez}, volume = {36}, number = {3}, pages = {165-181}, pmid = {15977799}, issn = {0475-1450}, mesh = {Biological Transport/physiology ; Breeding ; Endoplasmic Reticulum ; *Gene Expression Regulation, Plant ; Genes, Plant ; Phylogeny ; *Plant Development ; Plants/genetics ; Plastids/classification/*physiology ; }, abstract = {Phylogenetic and ontogenetic relationships between the plastids, cell endoplasmic reticulum, and plant transport communication have been reviewed. The initiating role of plastids (endosymbionts) in the origin of endoplasmic reticulum (buffer zone of endosymbiogenesis) has been shown, as well as a similar role of endoplasmic reticulum in the development of transport communication of xylem and phloem. Plastids, sugars and transport system for their distribution can be interpreted as leading sections in the mechanism of developmental control: gene expression of nuclear genome and genome of organelles, cell and tissue differentiation, and plant morphogenesis. The conflict between the bulk of plant genome and low percentage of its realization is explained as a result of limitation of the nuclear genome realization by plastid genome. The concept of development as applied to plant ontogenesis has been critically analyzed. The possibilities of the concept correction by with the help of symbiogenetic hypothesis are discussed.}, }
@article {pmid15969723, year = {2005}, author = {Van Oppen, MJ and Mieog, JC and Sánchez, CA and Fabricius, KE}, title = {Diversity of algal endosymbionts (zooxanthellae) in octocorals: the roles of geography and host relationships.}, journal = {Molecular ecology}, volume = {14}, number = {8}, pages = {2403-2417}, doi = {10.1111/j.1365-294X.2005.02545.x}, pmid = {15969723}, issn = {0962-1083}, mesh = {Animals ; Anthozoa/genetics/*parasitology/physiology ; Atlantic Ocean ; Base Sequence ; Bayes Theorem ; DNA Primers ; DNA, Ribosomal Spacer/genetics ; Dinoflagellida/*genetics ; *Genetic Variation ; Geography ; Models, Genetic ; Molecular Sequence Data ; Pacific Ocean ; *Phylogeny ; Pigmentation/physiology ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The presence, genetic identity and diversity of algal endosymbionts (Symbiodinium) in 114 species from 69 genera (20 families) of octocorals from the Great Barrier Reef (GBR), the far eastern Pacific (EP) and the Caribbean was examined, and patterns of the octocoral-algal symbiosis were compared with patterns in the host phylogeny. Genetic analyses of the zooxanthellae were based on ribosomal DNA internal transcribed spacer 1 (ITS1) region. In the GBR samples, Symbiodinium clades A and G were encountered with A and G being rare. Clade B zooxanthellae have been previously reported from a GBR octocoral, but are also rare in octocorals from this region. Symbiodinium G has so far only been found in Foraminifera, but is rare in these organisms. In the Caribbean samples, only Symbiodinium clades B and C are present. Hence, Symbiodinium diversity at the level of phylogenetic clades is lower in octocorals from the Caribbean compared to those from the GBR. However, an unprecedented level of ITS1 diversity was observed within individual colonies of some Caribbean gorgonians, implying either that these simultaneously harbour multiple strains of clade B zooxanthellae, or that ITS1 heterogeneity exists within the genomes of some zooxanthellae. Intracladal diversity based on ITS should therefore be interpreted with caution, especially in cases where no independent evidence exists to support distinctiveness, such as ecological distribution or physiological characteristics. All samples from EP are azooxanthellate. Three unrelated GBR taxa that are described in the literature as azooxanthellate (Junceella fragilis, Euplexaura nuttingi and Stereonephthya sp. 1) contain clade G zooxanthellae, and their symbiotic association with zooxanthellae was confirmed by histology. These corals are pale in colour, whereas related azooxanthellate species are brightly coloured. The evolutionary loss or gain of zooxanthellae may have altered the light sensitivity of the host tissues, requiring the animals to adopt or reduce pigmentation. Finally, we superimposed patterns of the octocoral-algal symbiosis onto a molecular phylogeny of the host. The data show that many losses/gains of endosymbiosis have occurred during the evolution of octocorals. The ancestral state (azooxanthellate or zooxanthellate) in octocorals remains unclear, but the data suggest that on an evolutionary timescale octocorals can switch more easily between mixotrophy and heterotrophy compared to scleractinian corals, which coincides with a low reliance on photosynthetic carbon gain in the former group of organisms.}, }
@article {pmid15964448, year = {2005}, author = {Taylor, MJ and Makunde, WH and McGarry, HF and Turner, JD and Mand, S and Hoerauf, A}, title = {Macrofilaricidal activity after doxycycline treatment of Wuchereria bancrofti: a double-blind, randomised placebo-controlled trial.}, journal = {Lancet (London, England)}, volume = {365}, number = {9477}, pages = {2116-2121}, doi = {10.1016/S0140-6736(05)66591-9}, pmid = {15964448}, issn = {1474-547X}, mesh = {Adolescent ; Adult ; Aged ; Animals ; Anti-Bacterial Agents/*therapeutic use ; Double-Blind Method ; Doxycycline/*therapeutic use ; Elephantiasis, Filarial/*drug therapy/parasitology ; Humans ; Male ; Middle Aged ; Wolbachia/*drug effects ; Wuchereria bancrofti/drug effects/*microbiology ; }, abstract = {BACKGROUND: Wolbachia endosymbionts of filarial nematodes are vital for larval development and adult-worm fertility and viability. This essential dependency on the bacterium for survival of the parasites has provided a new approach to treat filariasis with antibiotics. We used this strategy to investigate the effects of doxycycline treatment on the major cause of lymphatic filariasis, Wuchereria bancrofti.<br><br>METHODS: We undertook a double-blind, randomised, placebo-controlled field trial of doxycycline (200 mg per day) for 8 weeks in 72 individuals infected with W bancrofti from Kimang'a village, Pangani, Tanzania. Participants were randomly assigned by block randomisation to receive capsules of doxycycline (n=34) or placebo (n=38). We assessed treatment efficacy by monitoring microfilaraemia, antigenaemia, and ultrasound detection of adult worms. Follow-up assessments were done at 5, 8, 11, and 14 months after the start of treatment. Analysis was per protocol.<br><br>FINDINGS: One person from the doxycycline group died from HIV infection. Five (doxycycline) and 11 (placebo) individuals were absent at the time of ultrasound analysis. Doxycycline treatment almost completely eliminated microfilaraemia at 8-14 months' follow-up (for all timepoints p<0.001). Ultrasonography detected adult worms in only six (22%) of 27 individuals treated with doxycycline compared with 24 (88%) of 27 with placebo at 14 months after the start of treatment (p<0.0001). At the same timepoint, filarial antigenaemia in the doxycycline group fell to about half of that before treatment (p=0.015). Adverse events were few and mild.<br><br>INTERPRETATION: An 8-week course of doxycycline is a safe and well-tolerated treatment for lymphatic filariasis with significant activity against adult worms and microfilaraemia.}, }
@article {pmid15962806, year = {2005}, author = {Goethert, HK and Telford, SR}, title = {A new Francisella (Beggiatiales: Francisellaceae) inquiline within Dermacentor variabilis say (Acari: Ixodidae).}, journal = {Journal of medical entomology}, volume = {42}, number = {3}, pages = {502-505}, doi = {10.1093/jmedent/42.3.502}, pmid = {15962806}, issn = {0022-2585}, mesh = {Animals ; DNA, Bacterial/analysis ; Dermacentor/genetics/*microbiology ; Francisella/classification/genetics/*isolation &amp; purification ; Gram-Negative Bacterial Infections/transmission ; Larva/microbiology ; Massachusetts ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; }, abstract = {While estimating the prevalence of the Dermacentor variabilis (Say) symbiont (DVS) in dog ticks on Martha's Vineyard, MA, we identified DNA that may represent a heretofore unrecognized Francisella sp. Polymerase chain reaction targeting a portion of the 16S rDNA specific for DVS yielded an amplicon that was only 96.6% similar to that of DVS accessioned in GenBank. Phylogenetic analysis of the 16S and 23S rDNA genes suggests the presence of a distinct bacterium closely related to the other endosymbionts of Dermacentor spp. Fifty-five percent of dog ticks tested from three sites in Massachusetts showed evidence of infection with this new agent, called Dermacentor variabilis francisella (DVF), whereas 100% tested positive for DVS. All larval progeny of dog ticks known to contain DVF also showed evidence of colonization, demonstrating that this agent may be maintained by transovarial transmission. Coinfection of ticks with both Francisella species did not seem to interfere with transmission.}, }
@article {pmid15961259, year = {2005}, author = {Matthew, CZ and Darby, AC and Young, SA and Hume, LH and Welburn, SC}, title = {The rapid isolation and growth dynamics of the tsetse symbiont Sodalis glossinidius.}, journal = {FEMS microbiology letters}, volume = {248}, number = {1}, pages = {69-74}, doi = {10.1016/j.femsle.2005.05.024}, pmid = {15961259}, issn = {0378-1097}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Aedes/microbiology ; Animals ; Enterobacteriaceae/classification/genetics/*growth &amp; development/*isolation &amp; purification ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/analysis ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Sodalis glossinidius is known exclusively in endosymbiosis with tsetse flies (Genus: Glossina) and is one of the few insect bacterial symbionts that have been successfully cultured in vitro. This study details improved isolation and solid culture protocols that allow for a standardised and rapid preparation/maintenance of clonal material from individual flies. The isolation and culture of S. glossinidius was confirmed by partial sequencing of the 16S rDNA gene and specific PCR. In addition, the growth dynamics and changes in cell viability during liquid culture are described. The potential for culture of other endosymbiont taxa is discussed.}, }
@article {pmid15942697, year = {2005}, author = {Geiger, A and Ravel, S and Frutos, R and Cuny, G}, title = {Sodalis glossinidius (Enterobacteriaceae) and vectorial competence of Glossina palpalis gambiensis and Glossina morsitans morsitans for Trypanosoma congolense savannah type.}, journal = {Current microbiology}, volume = {51}, number = {1}, pages = {35-40}, pmid = {15942697}, issn = {0343-8651}, mesh = {Aedes/microbiology ; Animals ; Enterobacteriaceae/*classification/isolation &amp; purification ; Insect Vectors/classification/*parasitology ; Parasitemia/transmission ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*physiology ; Trypanosoma congolense/*physiology ; Trypanosomiasis, African/parasitology/transmission/veterinary ; Tsetse Flies/*microbiology ; }, abstract = {Sodalis glossinidius is an endosymbiont of Glossina palpalis gambiensis and Glossina morsitans morsitans, the vectors of Trypanosoma congolense. The presence of the symbiont was investigated by PCR in Trypanosoma congolense savannah type-infected and noninfected midguts of both fly species, and into the probosces of flies displaying either mature or immature infection, to investigate possible correlation with the vectorial competence of tsetse flies. Sodalis glossinidius was detected in all midguts, infected or not, from both Glossina species. It was also detected in probosces from Glossina palpalis gambiensis flies displaying mature or immature infection, but never in probosces from Glossina morsitans morsitans. These results suggest that, a) there might be no direct correlation between the presence of Sodalis glossinidius and the vectorial competence of Glossina, and b) the symbiont is probably not involved in Trypanosoma congolense savannah type maturation. It could however participate in the establishment process of the parasite.}, }
@article {pmid15940286, year = {2005}, author = {van der Giezen, M and Tovar, J}, title = {Degenerate mitochondria.}, journal = {EMBO reports}, volume = {6}, number = {6}, pages = {525-530}, pmid = {15940286}, issn = {1469-221X}, mesh = {*Biological Evolution ; DNA, Mitochondrial/*genetics ; *Genetic Variation ; Mitochondria/*genetics/*physiology/ultrastructure ; }, abstract = {Mitochondria are the main sites of biological energy generation in eukaryotes. These organelles are remnants of a bacterial endosymbiont that took up residence inside a host cell over 1,500 million years ago. Comparative genomics studies suggest that the mitochondrion is monophyletic in origin. Thus, the original mitochondrial endosymbiont has evolved independently in anaerobic and aerobic environments that are inhabited by diverse eukaryotic lineages. This process has resulted in a collection of morphologically, genetically and functionally heterogeneous organelle variants that include anaerobic and aerobic mitochondria, hydrogenosomes and mitosomes. Current studies aim to determine whether a central common function drives the retention of mitochondrial organelles in different eukaryotic organisms.}, }
@article {pmid15935576, year = {2005}, author = {Schaber, J and Rispe, C and Wernegreen, J and Buness, A and Delmotte, F and Silva, FJ and Moya, A}, title = {Gene expression levels influence amino acid usage and evolutionary rates in endosymbiotic bacteria.}, journal = {Gene}, volume = {352}, number = {}, pages = {109-117}, doi = {10.1016/j.gene.2005.04.003}, pmid = {15935576}, issn = {0378-1119}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {AT Rich Sequence/genetics ; Amino Acid Substitution/genetics ; Amino Acids/*genetics ; Animals ; Bacteria/*genetics ; Bacterial Proteins/genetics ; Buchnera/genetics ; Codon/genetics ; Databases, Nucleic Acid ; *Evolution, Molecular ; GC Rich Sequence/genetics ; *Gene Expression Regulation, Bacterial ; Insecta/microbiology ; Mutation ; Species Specificity ; Symbiosis ; Wigglesworthia/genetics ; }, abstract = {Most endosymbiotic bacteria have extremely reduced genomes, accelerated evolutionary rates, and strong AT base compositional bias thought to reflect reduced efficacy of selection and increased mutational pressure. Here, we present a comparative study of evolutionary forces shaping five fully sequenced bacterial endosymbionts of insects. The results of this study were three-fold: (i) Stronger conservation of high expression genes at not just nonsynonymous, but also synonymous, sites. (ii) Variation in amino acid usage strongly correlates with GC content and expression level of genes. This pattern is largely explained by greater conservation of high expression genes, leading to their higher GC content. However, we also found indication of selection favoring GC-rich amino acids that contrasts with former studies. (iii) Although the specific nutritional requirements of the insect host are known to affect gene content of endosymbionts, we found no detectable influence on substitution rates, amino acid usage, or codon usage of bacterial genes involved in host nutrition.}, }
@article {pmid15931253, year = {2005}, author = {Zeh, DW and Zeh, JA and Bonilla, MM}, title = {Wolbachia, sex ratio bias and apparent male killing in the harlequin beetle riding pseudoscorpion.}, journal = {Heredity}, volume = {95}, number = {1}, pages = {41-49}, doi = {10.1038/sj.hdy.6800666}, pmid = {15931253}, issn = {0018-067X}, support = {P20 RR16464/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Anti-Bacterial Agents/administration &amp; dosage/pharmacology ; Arachnida/*parasitology ; Female ; Inheritance Patterns ; Larva ; Male ; Mortality ; Selection, Genetic ; Tetracycline/administration &amp; dosage/pharmacology ; Wolbachia/*genetics/*pathogenicity ; }, abstract = {Bacterial endosymbionts that manipulate host reproduction are now known to be widespread in insects and other arthropods. Since they inhabit the cytoplasm and are maternally inherited, these microorganisms can enhance their fitness by biasing host sex ratio in favour of females. At its most extreme, sex ratio manipulation may be achieved by killing male embryos, as occurs in a number of insect species. Here, we provide evidence for the first case of male killing by a tetracycline-sensitive microbe in pseudoscorpions. Using a combination of inheritance studies, antibiotic treatment and molecular assays, we show that a new strain of Wolbachia is associated with extreme female bias in the pseudoscorpion, Cordylochernes scorpioides. In a highly female-biased line, sex ratio distortion was maternally inherited, and occurred in conjunction with a high rate of spontaneous abortion and low reproductive success. Antibiotic treatment cured females of the Wolbachia infection, restored offspring sex ratio to 1:1, and significantly enhanced female reproductive success. The discovery of apparent male-killing in C. scorpioides is of interest because pseudoscorpions are viviparous. Theory predicts that male killing should be favoured, if male death enhances the fitness of infected female siblings. In a live-bearing host, reallocation of maternal resources from dead male embryos to their sisters provides a direct, physiological mechanism through which fitness compensation could favour male killing by cellular endosymbionts. Our results suggest, however, that fitness compensation and the spread of male-killing endosymbionts may be undermined by a high rate of spontaneous abortion in infected females of this viviparous arthropod.}, }
@article {pmid15927071, year = {2005}, author = {Ahrens, ME and Shoemaker, D}, title = {Evolutionary history of Wolbachia infections in the fire ant Solenopsis invicta.}, journal = {BMC evolutionary biology}, volume = {5}, number = {}, pages = {35}, pmid = {15927071}, issn = {1471-2148}, mesh = {Animals ; Ants/*microbiology ; Bacterial Infections/*genetics ; DNA, Mitochondrial/*genetics/metabolism ; Evolution, Molecular ; *Genes, Bacterial ; Genetic Variation ; Genetics, Population ; Haplotypes ; Models, Biological ; Phylogeny ; Time Factors ; Wolbachia/*metabolism ; }, abstract = {BACKGROUND: Wolbachia are endosymbiotic bacteria that commonly infect numerous arthropods. Despite their broad taxonomic distribution, the transmission patterns of these bacteria within and among host species are not well understood. We sequenced a portion of the wsp gene from the Wolbachia genome infecting 138 individuals from eleven geographically distributed native populations of the fire ant Solenopsis invicta. We then compared these wsp sequence data to patterns of mitochondrial DNA (mtDNA) variation of both infected and uninfected host individuals to infer the transmission patterns of Wolbachia in S. invicta.<br><br>RESULTS: Three different Wolbachia (wsp) variants occur within S. invicta, all of which are identical to previously described strains in fire ants. A comparison of the distribution of Wolbachia variants within S. invicta to a phylogeny of mtDNA haplotypes suggests S. invicta has acquired Wolbachia infections on at least three independent occasions. One common Wolbachia variant in S. invicta (wSinvictaB) is associated with two divergent mtDNA haplotype clades. Further, within each of these clades, Wolbachia-infected and uninfected individuals possess virtually identical subsets of mtDNA haplotypes, including both putative derived and ancestral mtDNA haplotypes. The same pattern also holds for wSinvictaA, where at least one and as many as three invasions into S. invicta have occurred. These data suggest that the initial invasions of Wolbachia into host ant populations may be relatively ancient and have been followed by multiple secondary losses of Wolbachia in different infected lineages over time. Finally, our data also provide additional insights into the factors responsible for previously reported variation in Wolbachia prevalence among S. invicta populations.<br><br>CONCLUSION: The history of Wolbachia infections in S. invicta is rather complex and involves multiple invasions or horizontal transmission events of Wolbachia into this species. Although these Wolbachia infections apparently have been present for relatively long time periods, these data clearly indicate that Wolbachia infections frequently have been secondarily lost within different lineages. Importantly, the uncoupled transmission of the Wolbachia and mtDNA genomes suggests that the presumed effects of Wolbachia on mtDNA evolution within S. invicta are less severe than originally predicted. Thus, the common concern that use of mtDNA markers for studying the evolutionary history of insects is confounded by maternally inherited endosymbionts such as Wolbachia may be somewhat unwarranted in the case of S. invicta.}, }
@article {pmid15926693, year = {2005}, author = {Dyer, KA and Minhas, MS and Jaenike, J}, title = {Expression and modulation of embryonic male-killing in Drosophila innubila: opportunities for multilevel selection.}, journal = {Evolution; international journal of organic evolution}, volume = {59}, number = {4}, pages = {838-848}, pmid = {15926693}, issn = {0014-3820}, mesh = {Animals ; Arizona ; DNA Primers ; Drosophila/microbiology/*physiology ; Female ; Male ; Mortality ; Polymerase Chain Reaction/methods ; Population Density ; *Selection, Genetic ; *Sex Ratio ; *Symbiosis ; Temperature ; Tetracycline/toxicity ; Wolbachia/drug effects/genetics/*physiology ; }, abstract = {Organisms and the symbionts they harbor may experience opposing forces of selection. In particular, the contrasting inheritance patterns of maternally transmitted symbionts and their host's nuclear genes can engender conflict among organizational levels over the optimal host offspring sex ratio. This study uses a male-killing Wolbachia endosymbiont and its host Drosophila innubila to experimentally address the potential for multilevel selection in a host-symbiont system. We show that bacterial density can vary among infected females, and that females with a higher density have a more female-biased offspring sex ratio. Furthermore, bacterial density is an epigenetic and heritable trait: females with a low bacterial load have daughters with a lower-than-average bacterial density, whose offspring then experience less severe male-killing. For infected sons, the probability of embryonic mortality increases with the bacterial density in their mothers. The frequency distribution of Wolbachia density among individual D. innubila females, and therefore the dynamics of infection within populations of these flies, results both from processes affecting the growth and regulation of bacterial populations within cytoplasmic lineages and from selection among cytoplasmic lineages that vary in bacterial density. Estimates of effective population size of Wolbachia within cytoplasmic lineages and of D. innubila at the host population level suggest that selection among cytoplasmic lineages is likely to overwhelm the results of selection within lineages.}, }
@article {pmid15901574, year = {2002}, author = {Hu, K and Wu, QS}, title = {[The basic outline of the evolution of single cell life-form].}, journal = {Yi chuan = Hereditas}, volume = {24}, number = {1}, pages = {104-110}, pmid = {15901574}, issn = {0253-9772}, abstract = {In 1960s, kingdoms of organisms were charted generally in a five branching form. Later, the endosymbiont hypothesis for the mitochondria and the chloroplast was proposed. The life-form is divided into two forms, the prokaryotes (bacteria) and the eukaryotes. The study of the molecular biology made the progress faster. In 1980s, Woese, CR.asserted that two-domain view of life was no longer true, a three-domain construct, the Bacteria, the Archaea, and the Eukaryotes had to take its place. At first, phylogeny trees based on differences in the amino acid sequences, then among ribosomal RNAs and also nuclear gene from hundreds of microbial species were depicted and many mini phylogenetic trees grouped the species according to their differences in the sequences. It was found that they shared genes between their contemporaries and across the species barriers. At the root of the phylogeny tree, there was not a single common cell, it was replaced by a common ancestral community of primitive cells. Genes transfered rather freely as the transposons swapping between those cells. There was no last universal common ancestor of single cell that could be found in the revised Tree of Life, It was not easy to represent the genealogical patterns of thousands of different families of genes, in one systematic map, therefor there was no trunk at all.}, }
@article {pmid15895255, year = {2005}, author = {Köhler, S}, title = {Multi-membrane-bound structures of Apicomplexa: I. the architecture of the Toxoplasma gondii apicoplast.}, journal = {Parasitology research}, volume = {96}, number = {4}, pages = {258-272}, pmid = {15895255}, issn = {0932-0113}, mesh = {Animals ; Cell Wall/*ultrastructure ; DNA, Protozoan/analysis/immunology ; Immunohistochemistry ; Intracellular Membranes/*ultrastructure ; Microscopy, Electron, Transmission ; Organelles/*ultrastructure ; Toxoplasma/genetics/growth &amp; development/*ultrastructure ; }, abstract = {Apicomplexan parasites carry a plastid-like organelle termed apicoplast. The previous documentation of four membranes bordering the Toxoplasma gondii apicoplast suggested a secondary endosymbiotic ancestry of this organelle. However, a four-membraned apicoplast wall could not be confirmed for all Apicomplexa including the malarial agents. The latter reportedly possesses a mostly tri-laminar plastid wall but also displays two multi-laminar wall partitions. Since these sectors apparently evolved from regional wall membrane infoldings, the malarial plastid could have lost one secondary wall membrane in the course of evolution. Such wall construction was however not unambiguously resolved. To examine whether the wall of the T. gondii apicoplast is comparably complex, serial ultra-thin sections of tachyzoites were analyzed. This investigation revealed a single pocket-like invagination within a four-laminar wall segment but also disclosed that four individual membranes do not surround the entire T. gondii apicoplast. Instead, this organelle possesses an extensive sector that is bordered by two membranes. Such heterogeneous wall construction could be explained if the inner two membranes of a formerly four-membraned endosymbiont are partially lost. However, our findings are more consistent with an essentially dual-membraned organelle that creates four-laminar wall sectors by expansive infoldings of its interior border. Given this architecture, the T. gondii apicoplast depicts a residual primary plastid not a secondary one as presently proposed.}, }
@article {pmid15892692, year = {2006}, author = {Lechaire, JP and Frébourg, G and Gaill, F and Gros, O}, title = {In situ localization of sulphur in the thioautotrophic symbiotic model Lucina pectinata (Gmelin, 1791) by cryo-EFTEM microanalysis.}, journal = {Biology of the cell}, volume = {98}, number = {3}, pages = {163-170}, doi = {10.1042/BC20040502}, pmid = {15892692}, issn = {0248-4900}, mesh = {Animals ; Bivalvia/microbiology ; Cryoultramicrotomy/*methods ; Freezing ; Gram-Negative Chemolithotrophic Bacteria/*chemistry/ultrastructure ; Microscopy, Electron, Transmission ; Microscopy, Energy-Filtering Transmission Electron/*methods ; Sulfur/*analysis ; *Symbiosis ; }, abstract = {BACKGROUND INFORMATION: Lucina pectinata is a large tropical lucinid known to harbour sulphide-oxidizing bacteria in specialized gill cells. Conventional TEM (transmission electron microscopy) has shown that bacteriocytes also harbour visibly 'empty' vesicles whose chemical content remains, to date, only roughly determined.<br><br>RESULTS: In the present study, L. pectinata gill tissues were cryo-fixed as fast as possible by performing high-pressure freezing before a freeze-substitution process and finally performing a cryo-embedding in Lowicryl. Ultrathin sections were then used for a cryo-EFTEM (where EFTEM stands for energy-filtered TEM) microanalysis. Results show that bacteriocytes within the gill tissues contain elemental sulphur in small vesicles produced by the host itself. In instances of sporadic depletion of sulphur in the environment, such structures may act as energy sources for bacterial endosymbionts.<br><br>CONCLUSIONS: The cryo-EFTEM techniques represent (i) the only method used to date to locate and preserve sulphur at the cellular level and (ii) a powerful tool for sulphur metabolism analysis in thioautotrophic symbiont relationships.}, }
@article {pmid15890537, year = {2005}, author = {Maekawa, K and Park, YC and Lo, N}, title = {Phylogeny of endosymbiont bacteria harbored by the woodroach Cryptocercus spp. (Cryptocercidae: Blattaria): molecular clock evidence for a late Cretaceous--early Tertiary split of Asian and American lineages.}, journal = {Molecular phylogenetics and evolution}, volume = {36}, number = {3}, pages = {728-733}, doi = {10.1016/j.ympev.2005.03.033}, pmid = {15890537}, issn = {1055-7903}, mesh = {Animals ; Asia ; Bacteria/*genetics/isolation &amp; purification ; Cockroaches/*classification/*microbiology ; DNA, Mitochondrial/genetics ; North America ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Time Factors ; }, }
@article {pmid15876578, year = {2005}, author = {Hammerstein, P}, title = {Strategic analysis in evolutionary genetics and the theory of games.}, journal = {Journal of genetics}, volume = {84}, number = {1}, pages = {7-12}, pmid = {15876578}, issn = {0022-1333}, mesh = {Animals ; *Evolution, Molecular ; *Game Theory ; *Models, Genetic ; Phenotype ; Quantitative Trait, Heritable ; Selection, Genetic ; }, abstract = {This paper is written in memory of John Maynard Smith. In a brief survey it discusses essential aspects of how game theory in biology relates to its counterpart in economics, the major transition in game theory initiated by Maynard Smith, the discrepancies between genetic and phenotypic models in evolutionary biology, and a balanced way of reconciling these models. In addition, the paper discusses modern problems in understanding games at the genetic level using the examples of conflict between endosymbionts and their hosts, and the molecular interactions between parasites and the mammalian immune system.}, }
@article {pmid15876457, year = {2005}, author = {Kramer, LH and Tamarozzi, F and Morchón, R and López-Belmonte, J and Marcos-Atxutegi, C and Martín-Pacho, R and Simón, F}, title = {Immune response to and tissue localization of the Wolbachia surface protein (WSP) in dogs with natural heartworm (Dirofilaria immitis) infection.}, journal = {Veterinary immunology and immunopathology}, volume = {106}, number = {3-4}, pages = {303-308}, doi = {10.1016/j.vetimm.2005.03.011}, pmid = {15876457}, issn = {0165-2427}, mesh = {Animals ; Antibodies, Bacterial/biosynthesis ; Bacterial Outer Membrane Proteins/*immunology/metabolism ; Dirofilaria immitis/*microbiology ; Dirofilariasis/*immunology/*microbiology/parasitology ; Dogs ; Female ; Humans ; Immunoglobulin G/biosynthesis ; Immunohistochemistry ; Wolbachia/*immunology ; }, abstract = {Human and animal parasitic filarial nematodes, including the agent of canine and feline heartworm disease Dirofilaria immitis, harbour intracellular bacteria of the genus Wolbachia (Rickettsiaies). It is thought that these bacteria play an important role in the pathogenesis and immune response to filarial infection. Immunoglobulin G (total IgG, IgG1, IgG2) production against and immunohistochemical staining of tissues for the Wolbachia surface protein (WSP) from dogs with natural heartworm infection were evaluated. All infected dogs had significant total anti-WSP IgG levels compared to healthy controls. Interestingly, WSP was recognized by the IgG2 subclass in both microfilariemic dogs and in dogs with no circulating microfilariae (occult infection). However, microfilariemic dogs also produced gG1 antibodies. Positive staining for WSP was observed in lungs, liver and kidneys, in particular in glomerular capillaries of naturally infected dogs who had died from heartworm disease. Our results show for the first time that Wolbachia is recognized specifically by D. immitis--infected dogs and that the bacteria is released into host tissue. Furthermore, microfilariemic status appears to effect immune responses to this endosymbiont.}, }
@article {pmid15872156, year = {2005}, author = {Kawach, O and Voss, C and Wolff, J and Hadfi, K and Maier, UG and Zauner, S}, title = {Unique tRNA introns of an enslaved algal cell.}, journal = {Molecular biology and evolution}, volume = {22}, number = {8}, pages = {1694-1701}, doi = {10.1093/molbev/msi161}, pmid = {15872156}, issn = {0737-4038}, mesh = {Base Sequence ; Cryptophyta/*genetics ; Gene Expression Regulation, Plant/genetics ; Introns/*genetics ; Molecular Sequence Data ; RNA Splicing/*genetics ; RNA, Algal/*genetics ; RNA, Transfer/*genetics ; Transcription, Genetic/genetics ; }, abstract = {Nucleomorphs are remnant nuclei of eukaryotic, secondary endosymbionts exclusively found in cryptophytes and chlorarachniophytes. The nucleomorph of the cryptophyte Guillardia theta codes for 36 transfer RNA (tRNA) genes, 15 of them predicted to contain introns and 1 pseudo-tRNA. Some of the predicted intervening sequences are manifested at positions not known in Eukarya, even tRNAs with more than one intron were suggested. By isolating reverse transcriptase-polymerase chain reaction products of the spliced tRNAs we verify the processing of all predicted intron-harboring tRNAs and demonstrate the splicing of the smallest introns (3 nt) investigated so far. However, the spliced intervening sequences are in some cases shifted in respect to the predicted ones. Moreover, we show that introns, if inserted into the B-box of tRNA genes in the nucleomorph of cryptophytes, mimic promoter regions and do not abolish transcription by RNA polymerase III. Consequently, internal nucleomorph-encoded tRNA promoter regions are in some cases dissected from the sequence of the mature tRNAs. By reanalyzing tRNA introns of a recently sequenced red algae we furthermore show that splicing of introns at unusual positions may be introduced in cryptophytes by its secondary endosymbiont. However, in contrast to the rest of the symbiont genome, introns are not minimized in quantity but are instead scattered along the tRNA genes.}, }
@article {pmid15866917, year = {2005}, author = {Mesa, S and Ucurum, Z and Hennecke, H and Fischer, HM}, title = {Transcription activation in vitro by the Bradyrhizobium japonicum regulatory protein FixK2.}, journal = {Journal of bacteriology}, volume = {187}, number = {10}, pages = {3329-3338}, pmid = {15866917}, issn = {0021-9193}, mesh = {Aerobiosis ; Bacterial Proteins/*genetics/isolation &amp; purification/metabolism ; Bradyrhizobium/*genetics/metabolism ; Coproporphyrinogen Oxidase/genetics ; Gene Expression Regulation, Bacterial/*physiology ; In Vitro Techniques ; Nitrogen Fixation/*genetics ; Promoter Regions, Genetic/physiology ; Transcriptional Activation/*physiology ; }, abstract = {In Bradyrhizobium japonicum, the N2-fixing root nodule endosymbiont of soybean, a group of genes required for microaerobic, anaerobic, or symbiotic growth is controlled by FixK2, a key regulator that is part of the FixLJ-FixK2 cascade. FixK2 belongs to the family of cyclic AMP receptor protein/fumarate and nitrate reductase (CRP/FNR) transcription factors that recognize a palindromic DNA motif (CRP/FNR box) associated with the regulated promoters. Here, we report on a biochemical analysis of FixK2 and its transcription activation activity in vitro. FixK2 was expressed in Escherichia coli and purified as a soluble N-terminally histidine-tagged protein. Gel filtration experiments revealed that increasing the protein concentration shifts the monomer-dimer equilibrium toward the dimer. Purified FixK2 productively interacted with the B. japonicum sigma80-RNA polymerase holoenzyme, but not with E. coli sigma70-RNA polymerase holoenzyme, to activate transcription from the B. japonicum fixNOQP, fixGHIS, and hemN2 promoters in vitro. Furthermore, FixK2 activated transcription from the E. coli FF(-41.5) model promoter, again only in concert with B. japonicum RNA polymerase. All of these promoters are so-called class II CRP/FNR-type promoters. We showed by specific mutagenesis that the FixK2 box at nucleotide position -40.5 in the hemN2 promoter, but not that at -78.5, is crucial for activation both in vivo and in vitro, which argues against recognition of a potential class III promoter. Given the lack of any evidence for the presence of a cofactor in purified FixK2, we surmise that FixK2 alone is sufficient to activate in vitro transcription to at least a basal level. This contrasts with all well-studied CRP/FNR-type proteins, which do require coregulators.}, }
@article {pmid15842494, year = {2005}, author = {Fares, MA and Moya, A and Barrio, E}, title = {Adaptive evolution in GroEL from distantly related endosymbiotic bacteria of insects.}, journal = {Journal of evolutionary biology}, volume = {18}, number = {3}, pages = {651-660}, doi = {10.1111/j.1420-9101.2004.00861.x}, pmid = {15842494}, issn = {1010-061X}, mesh = {Adaptation, Biological/*genetics ; Amino Acid Substitution/genetics ; Animals ; Bacteria/*genetics/metabolism ; Base Sequence ; Chaperonin 60/*genetics/metabolism ; Cluster Analysis ; Codon/genetics ; DNA Primers ; *Evolution, Molecular ; Insecta/*microbiology ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Protein Conformation ; Selection, Genetic ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Many symbioses between bacteria and insects resulted from ancient infections followed by strict vertical transmission within host lineages. The strong bottlenecks under which this transmission occurs promote the neutral fixation of slightly deleterious mutations by genetic drift. As predicted by Muller's ratchet, this fixation will drive endosymbiotic bacteria through an irreversible dynamics of fitness loss. The chaperonin GroEL has been proposed as a compensatory mechanism whereby endosymbiotic bacteria of aphids persist. Here, we show that endosymbiotic bacteria of insects from two phylogenetically very distant bacterial phyla have fixed amino acid substitutions by positive selection in functionally important GroEL regions involved in either GroES/peptide binding or in the en bloc movement of the GroEL apical domain. These results, together with the high levels of constitutive expression of GroEL in these endosymbionts, provide valuable insights into the evolution of a molecular mechanism responsible for the maintenance of the symbiotic lifestyle.}, }
@article {pmid15830815, year = {2005}, author = {D'Avila-Levy, CM and Araújo, FM and Vermelho, AB and Soares, RM and Santos, AL and Branquinha, MH}, title = {Proteolytic expression in Blastocrithidia culicis: influence of the endosymbiont and similarities with virulence factors of pathogenic trypanosomatids.}, journal = {Parasitology}, volume = {130}, number = {Pt 4}, pages = {413-420}, doi = {10.1017/s0031182004006705}, pmid = {15830815}, issn = {0031-1820}, mesh = {Animals ; Blotting, Western ; Caseins/metabolism ; Cysteine Endopeptidases/metabolism ; Electrophoresis, Polyacrylamide Gel ; Gelatin/metabolism ; Glycosylphosphatidylinositol Diacylglycerol-Lyase ; Hemoglobins/metabolism ; Metalloendopeptidases/metabolism ; Peptide Hydrolases/*metabolism ; Phosphatidylinositol Diacylglycerol-Lyase/metabolism ; Protozoan Proteins ; Serum Albumin, Bovine/metabolism ; Symbiosis/physiology ; Trypanosomatina/*enzymology/physiology ; }, abstract = {Blastocrithidia culicis is an insect trypanosomatid that presents bacterial endosymbionts. The cell-associated and secreted proteinases of the endosymbiont-bearing and aposymbiotic strains were compared through the incorporation of proteinaceous substrates into sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Few qualitative changes could be detected in the proteolytic zymograms in the 2 strains studied when gelatin, casein, haemoglobin or bovine serum albumin (BSA) were tested. However, the level of proteolytic activities was significantly higher in the aposymbiotic strain. Some of the B. culicis proteins reacted in Western blots with antibodies raised against gp63, a zinc-metalloproteinase, and cruzipain, a cysteinyl-proteinase, which are virulence factors of the human pathogenic trypanosomatids, Leishmania spp. and Trypanosoma cruzi, respectively. The anti-cross-reacting determinant (CRD) antibody recognized 2 polypeptides (50 and 58 kDa) in the spent culture media and in the supernatant from glycosylphosphatidylinositol-phospholipase C (GPI-PLC)-treated cells, suggesting that these proteins are GPI-anchored to the plasma membrane. In addition, the anti-gp63 reacted with the 50 kDa protein. The identification of protein homologues in trypanosomatids with distinct life-cycles may help to determine the importance of proteinases in trypanosomatids.}, }
@article {pmid15830125, year = {2005}, author = {Chaal, BK and Green, BR}, title = {Protein import pathways in 'complex' chloroplasts derived from secondary endosymbiosis involving a red algal ancestor.}, journal = {Plant molecular biology}, volume = {57}, number = {3}, pages = {333-342}, pmid = {15830125}, issn = {0167-4412}, mesh = {Algal Proteins/genetics/*metabolism ; Amino Acid Sequence ; Animals ; Chloroplasts/drug effects/genetics/*metabolism ; Dinoflagellida/metabolism ; Dogs ; Endoplasmic Reticulum/enzymology ; Membrane Proteins/metabolism ; Metalloendopeptidases/genetics/metabolism ; Microsomes/metabolism ; Molecular Sequence Data ; Peas/genetics/metabolism ; Plant Proteins/genetics/metabolism ; Protein Biosynthesis ; Protein Processing, Post-Translational ; Protein Transport/drug effects ; Protozoan Proteins/metabolism ; Rhodophyta/*genetics/growth &amp; development/metabolism ; Sequence Homology, Amino Acid ; Serine Endopeptidases/metabolism ; Sodium Azide/pharmacology ; Symbiosis ; Thermolysin/pharmacology ; Thylakoids/drug effects/metabolism ; }, abstract = {Heterokont algae such as diatoms and the raphidophyte Heterosigma akashiwo and peridinin-containing dinoflagellates such as Heterocapsa triquetra originally acquired their chloroplasts via secondary endosymbiosis involving a red algal endosymbiont and a eukaryote host, resulting in 'complex' chloroplasts surrounded by four and three membranes, respectively. The precursors of both heterokont and dinoflagellate chloroplast-targeted proteins are first inserted into the ER with removal of an N-terminal signal peptide, but how they traverse the remaining membranes is unclear. Using a nuclear-encoded thylakoid lumen protein, PsbO, from the heterokont alga Heterosigma akashiwo, the dinoflagellate Heterocapsa triquetra and the red alga Porphyra yezoensis we show that precursors without the ER signal peptide can be imported into pea chloroplasts. In the case of the H. triquetra and Porphyra PsbO, the precursors were processed to their predicted mature size and localized within the thylakoid lumen, using the Sec-dependent pathway. We report for the first time a stromal processing peptidase (SPP) activity from an alga of the red lineage. The enzyme processes the Heterosigma PsbO precursor at a single site and appears to have different substrate and reaction specificities from the plant SPP. In spite of the fact that we could not find convincing homologs of the plant chloroplast import machinery in heterokont (diatom) and red algal genomes, it is clear that these three very different lines of algae use similar mechanisms to import chloroplast precursors.}, }
@article {pmid15819856, year = {2005}, author = {Urakawa, H and Dubilier, N and Fujiwara, Y and Cunningham, DE and Kojima, S and Stahl, DA}, title = {Hydrothermal vent gastropods from the same family (Provannidae) harbour epsilon- and gamma-proteobacterial endosymbionts.}, journal = {Environmental microbiology}, volume = {7}, number = {5}, pages = {750-754}, doi = {10.1111/j.1462-2920.2005.00753.x}, pmid = {15819856}, issn = {1462-2912}, mesh = {Animals ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; Epsilonproteobacteria/genetics/growth &amp; development/*physiology/ultrastructure ; Gammaproteobacteria/genetics/growth &amp; development/*physiology/ultrastructure ; Gills/microbiology/ultrastructure ; Microscopy, Electron, Transmission ; Molecular Sequence Data ; Mollusca/*microbiology/ultrastructure ; Pacific Ocean ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/chemistry/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The discovery of new hydrothermal vent systems in the back-arc basins of the Western Pacific revealed chemosynthesis-based faunal communities distinct from those of other vents. These vents are dominated by two related gastropods (Alviniconcha spp. and Ifremeria nautilei) that harbour symbiotic bacteria in their gills. We used comparative 16S ribosomal RNA (rRNA) gene sequencing and in situ hybridization with rRNA-targeted probes to characterize the bacterial symbionts of Alviniconcha sp. and I. nautilei from the Manus Basin in the Western Pacific. The analyses revealed that these two gastropod species, although affiliated with the same family, harbour phylogenetically distant chemosymbionts, suggesting independent origins of these endosymbioses. The I. nautilei endosymbiont clusters with sulfur-oxidizing bacteria within the gamma-Proteobacteria, as is the case for all previously characterized endosymbionts from a wide diversity of host taxa harbouring thioautotrophic prokaryotes. In contrast, the Alviniconcha endosymbiont is affiliated with sulfur-oxidizing bacteria within the epsilon-Proteobacteria. These results show that bacteria from the epsilon-Proteobacteria are also capable of forming endosymbiotic associations with marine invertebrates from chemosynthetic environments. More generally, the endosymbiotic lifestyle is now shown to be distributed throughout all recognized classes of the Proteobacteria.}, }
@article {pmid15811532, year = {2005}, author = {Higazi, TB and Filiano, A and Katholi, CR and Dadzie, Y and Remme, JH and Unnasch, TR}, title = {Wolbachia endosymbiont levels in severe and mild strains of Onchocerca volvulus.}, journal = {Molecular and biochemical parasitology}, volume = {141}, number = {1}, pages = {109-112}, doi = {10.1016/j.molbiopara.2005.02.006}, pmid = {15811532}, issn = {0166-6851}, mesh = {Animals ; DNA, Bacterial/analysis ; Female ; Humans ; Male ; Onchocerca volvulus/isolation &amp; purification/microbiology/*pathogenicity ; Onchocerciasis, Ocular/etiology ; Symbiosis ; Virulence ; Wolbachia/genetics/*physiology ; }, abstract = {Epidemiological, clinical and genetic data have all suggested that the filarial parasite Onchocerca volvulus, the causative agent of onchocerciasis (or river blindness) exists as two strains in West Africa. The severe strain induces severe ocular disease in a large proportion of the infected population, while the mild strain induces little ocular disease. Although DNA probes based upon a non-coding repeat sequence family can distinguish the two strains, the underlying basis for this difference in pathogenicity is not understood. Recently, several studies have implicated products produced by the Wolbachia endosymbiotic bacterium of O. volvulus in the pathogenesis of onchocerciasis. This suggested the hypothesis that differences in the Wolbachia endosymbiont population might be responsible for the pathogenic differences noted in the two strains. To test this hypothesis, quantitative PCR assays were used to measure the amount of Wolbachia DNA per nuclear genome in a collection of well characterized samples of mild and severe strain O. volvulus. The median ratio of Wolbachia DNA to nuclear DNA was significantly greater in severe strain parasites than in mild strain parasites. These data support the hypothesis that the pathogenic differences seen in severe and mild strain O. volvulus may be a function of their relative Wolbachia burden and provide additional support to the hypothesis that Wolbachia products may play a central role in the pathogenesis of ocular onchocerciasis.}, }
@article {pmid15807436, year = {2005}, author = {Dudkina, NV and Kiseleva, EV}, title = {[Structural organization and distribution of the symbiotic bacteria Wolbachia during spermatogenesis of Drosophila simulans].}, journal = {Ontogenez}, volume = {36}, number = {1}, pages = {41-50}, pmid = {15807436}, issn = {0475-1450}, mesh = {Animals ; Drosophila/microbiology/physiology/*ultrastructure ; Male ; Meiosis ; Microscopy, Electron, Transmission ; Microtubules/ultrastructure ; Mitochondria/ultrastructure ; Spermatogenesis ; Spermatozoa/microbiology/*ultrastructure ; Symbiosis ; Wolbachia/physiology/*ultrastructure ; }, abstract = {Electron microscopy and morphometric analysis have shown that the symbiotic bacteria Wolbachia occur the testis cells during spermatogenesis and are absent in mature spermatids. Bacteria did not affect the structural organization of testis cells, which have a typical morphology during morphogenesis. Bacteria were distributed along the meiotic spindle microtubules near the mitochondria. They increased in number in spermatids at the stage of elongation. Endosymbionts aggregated at the spermatid distal end and contained many vacuoles but were absent at the spermatid proximal end near the nuclei. It was shown for the first time that the diameter of spermatids in a strongly infected line was two of three times that in a noninfected line. We hypothesize that the increase in the number of endosymbionts during spermatid elongation can affect the chromatin condensation in the spermatozoon.}, }
@article {pmid15799519, year = {2005}, author = {Chen, WJ and Tsai, KH and Cheng, SL and Huang, CG and Wu, WJ}, title = {Using in situ hybridization to detect endosymbiont Wolbachia in dissected tissues of mosquito host.}, journal = {Journal of medical entomology}, volume = {42}, number = {2}, pages = {120-124}, doi = {10.1093/jmedent/42.2.120}, pmid = {15799519}, issn = {0022-2585}, mesh = {Aedes/*microbiology ; Animals ; Bacterial Outer Membrane Proteins/genetics ; DNA Probes ; *In Situ Hybridization ; Microscopy, Electron ; Salivary Glands/microbiology ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {The endosymbiont Wolbachia, extensively occurring in arthropods, usually causes reproductive distortions of the host, such as mosquitoes. In past years, detection of Wolbachia in host tissues has highly relied on transmission electron microscopy (TEM) that is tedious and usually unable to gain satisfactory results without experienced techniques and expensive instruments. Polymerase chain reaction (PCR) recently has become popular in Wolbachia identification. However, necessity of DNA extraction from host individuals or dissected tissues has limited its application in extensiveness and versatility. At present, in situ hybridization has increased its role in examination of various microbes. This report provides a technique for rapid detection and localization of Wolbachia in tissues dissected from mosquitoes and possibly other infected organisms. To detect Wolbachia and to localize them in host tissues more precisely, in situ hybridization by using digoxigenin (DIG)-labeled probes was invented and applied to Wolbachia detection in this study. The results showed that Wolbachia preferentially aggregate in ovarioles, which is consistent with previous observations by TEM. The endobacteria also were detected in salivary glands, mostly in lateral lobes. Ultrastructurally, Wolbachia has been shown to occur in the cytoplasma of salivary gland cells.}, }
@article {pmid15797929, year = {2005}, author = {Sláviková, S and Vacula, R and Fang, Z and Ehara, T and Osafune, T and Schwartzbach, SD}, title = {Homologous and heterologous reconstitution of Golgi to chloroplast transport and protein import into the complex chloroplasts of Euglena.}, journal = {Journal of cell science}, volume = {118}, number = {Pt 8}, pages = {1651-1661}, doi = {10.1242/jcs.02277}, pmid = {15797929}, issn = {0021-9533}, mesh = {Adenosine Triphosphate/metabolism ; Animals ; Chloroplasts/*metabolism/ultrastructure ; Euglena gracilis/*metabolism/ultrastructure ; Glycosylphosphatidylinositols/metabolism ; Golgi Apparatus/*metabolism/ultrastructure ; Intracellular Membranes/metabolism/ultrastructure ; Light-Harvesting Protein Complexes/metabolism ; Membrane Fusion/physiology ; Peptides/metabolism ; Plant Proteins/*metabolism ; Protein Processing, Post-Translational/physiology ; Protein Structure, Tertiary/physiology ; Protein Transport/physiology ; Ribulose-Bisphosphate Carboxylase/metabolism ; Signal Transduction/physiology ; Transport Vesicles/*metabolism ; }, abstract = {Euglena complex chloroplasts evolved through secondary endosymbiosis between a phagotrophic trypanosome host and eukaryotic algal endosymbiont. Cytoplasmically synthesized chloroplast proteins are transported in vesicles as integral membrane proteins from the ER to the Golgi apparatus to the Euglena chloroplast. Euglena chloroplast preprotein pre-sequences contain a functional N-terminal ER-targeting signal peptide and a domain having characteristics of a higher plant chloroplast targeting transit peptide, which contains a hydrophobic stop-transfer membrane anchor sequence that anchors the precursor in the vesicle membrane. Pulse-chase subcellular fractionation studies showed that (35)S-labeled precursor to the light harvesting chlorophyll a/b binding protein accumulated in the Golgi apparatus of Euglena incubated at 15 degrees C and transport to the chloroplast resumed after transfer to 26 degrees C. Transport of the (35)S-labeled precursor to the chlorophyll a/b binding protein from Euglena Golgi membranes to Euglena chloroplasts and import into chloroplasts was reconstituted using Golgi membranes isolated from 15 degrees C cells returned to 26 degrees C. Transport was dependent upon extra- and intrachloroplast ATP and GTP hydrolysis. Golgi to chloroplast transport was not inhibited by N-ethylmaleimide indicating that fusion of Golgi vesicles to the chloroplast envelope does not require N-ethylmaleimide-sensitive factor (NSF). This suggests that N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are not utilized in the targeting fusion reaction. The Euglena precursor to the chloroplast-localized small subunit of ribulose-1,5-bisphosphate carboxylase was not imported into isolated pea chloroplasts. A precursor with the N-terminal signal peptide deleted was imported, indicating that the Euglena pre-sequence has a transit peptide that functions in pea chloroplasts. A precursor to the small subunit of ribulose-1,5-bisphosphate carboxylase with the hydrophobic membrane anchor and the pre-sequence region C-terminal to the hydrophobic membrane anchor deleted was imported localizing the functional transit peptide to the Euglena pre-sequence region between the signal peptidase cleavage site and the hydrophobic membrane anchor. The Euglena precursor to the small subunit of ribulose-1,5-bisphosphate carboxylase and the deletion constructs were not post-translationally imported into isolated Euglena chloroplasts indicating that vesicular transport is the obligate import mechanism. Taken together, these studies suggest that protein import into complex Euglena chloroplasts evolved by developing a novel vesicle fusion targeting system to link the host secretory system to the transit peptide-dependent chloroplast protein import system of the endosymbiont.}, }
@article {pmid15796009, year = {2005}, author = {El-Shewy, KA and Eid, RA}, title = {In vivo killing of Giardia trophozoites harbouring bacterial endosymbionts by intestinal Paneth cells: an ultrastructural study.}, journal = {Parasitology}, volume = {130}, number = {Pt 3}, pages = {269-274}, doi = {10.1017/s0031182004006547}, pmid = {15796009}, issn = {0031-1820}, mesh = {Animals ; Giardia/*microbiology ; Giardiasis/immunology/parasitology ; Host-Parasite Interactions ; Mice ; Paneth Cells/*physiology/ultrastructure ; Symbiosis ; }, abstract = {To date Paneth cells have not previously been reported to kill Giardia trophozoites and other protozoa in vivo. Here we report the first evidence for in vivo killing of Giardia trophozoites by intestinal Paneth cells. Transmission electron microscopic (TEM) examination of duodenal specimens taken from naturally infected mice revealed that only Giardia trophozoites harbouring peripheral bacterial endosymbionts were destroyed and lysed in the vicinity of the activated Paneth cells. Additionally, intestinal epithelium was more affected by Giardia harbouring bacterial endosymbionts than Giardia with no endosymbionts. Our findings imply that the bacterial endosymbionts within Giardia trophozoites have a role in both host protective and pathological mechanisms, probably through altering the trophozoite antigencity. These observations might shed light on the diversity in infectivity and host specificity of Giardia species.}, }
@article {pmid15780005, year = {2005}, author = {Foster, J and Ganatra, M and Kamal, I and Ware, J and Makarova, K and Ivanova, N and Bhattacharyya, A and Kapatral, V and Kumar, S and Posfai, J and Vincze, T and Ingram, J and Moran, L and Lapidus, A and Omelchenko, M and Kyrpides, N and Ghedin, E and Wang, S and Goltsman, E and Joukov, V and Ostrovskaya, O and Tsukerman, K and Mazur, M and Comb, D and Koonin, E and Slatko, B}, title = {The Wolbachia genome of Brugia malayi: endosymbiont evolution within a human pathogenic nematode.}, journal = {PLoS biology}, volume = {3}, number = {4}, pages = {e121}, pmid = {15780005}, issn = {1545-7885}, mesh = {Animals ; Brugia malayi/*genetics/pathogenicity ; *Evolution, Molecular ; Gene Expression Regulation, Bacterial ; *Genome, Bacterial ; Humans ; Molecular Sequence Data ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {Complete genome DNA sequence and analysis is presented for Wolbachia, the obligate alpha-proteobacterial endosymbiont required for fertility and survival of the human filarial parasitic nematode Brugia malayi. Although, quantitatively, the genome is even more degraded than those of closely related Rickettsia species, Wolbachia has retained more intact metabolic pathways. The ability to provide riboflavin, flavin adenine dinucleotide, heme, and nucleotides is likely to be Wolbachia's principal contribution to the mutualistic relationship, whereas the host nematode likely supplies amino acids required for Wolbachia growth. Genome comparison of the Wolbachia endosymbiont of B. malayi (wBm) with the Wolbachia endosymbiont of Drosophila melanogaster (wMel) shows that they share similar metabolic trends, although their genomes show a high degree of genome shuffling. In contrast to wMel, wBm contains no prophage and has a reduced level of repeated DNA. Both Wolbachia have lost a considerable number of membrane biogenesis genes that apparently make them unable to synthesize lipid A, the usual component of proteobacterial membranes. However, differences in their peptidoglycan structures may reflect the mutualistic lifestyle of wBm in contrast to the parasitic lifestyle of wMel. The smaller genome size of wBm, relative to wMel, may reflect the loss of genes required for infecting host cells and avoiding host defense systems. Analysis of this first sequenced endosymbiont genome from a filarial nematode provides insight into endosymbiont evolution and additionally provides new potential targets for elimination of cutaneous and lymphatic human filarial disease.}, }
@article {pmid15774626, year = {2005}, author = {Vinuesa, P and León-Barrios, M and Silva, C and Willems, A and Jarabo-Lorenzo, A and Pérez-Galdona, R and Werner, D and Martínez-Romero, E}, title = {Bradyrhizobium canariense sp. nov., an acid-tolerant endosymbiont that nodulates endemic genistoid legumes (Papilionoideae: Genisteae) from the Canary Islands, along with Bradyrhizobium japonicum bv. genistearum, Bradyrhizobium genospecies alpha and Bradyrhizobium genospecies beta.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {55}, number = {Pt 2}, pages = {569-575}, doi = {10.1099/ijs.0.63292-0}, pmid = {15774626}, issn = {1466-5026}, mesh = {Bacterial Proteins ; Bradyrhizobium/*classification/drug effects/growth &amp; development ; DNA, Ribosomal Spacer/analysis ; Evolution, Molecular ; Fabaceae/classification/*microbiology ; Hydrogen-Ion Concentration ; Molecular Sequence Data ; N-Acetylglucosaminyltransferases/genetics ; Nucleic Acid Hybridization ; Oxidoreductases/genetics ; Phenotype ; Phylogeny ; Sequence Analysis, DNA ; Spain ; *Symbiosis ; }, abstract = {Highly diverse Bradyrhizobium strains nodulate genistoid legumes (brooms) in the Canary Islands, Morocco, Spain and the Americas. Phylogenetic analyses of ITS, atpD, glnII and recA sequences revealed that these isolates represent at least four distinct evolutionary lineages within the genus, namely Bradyrhizobium japonicum and three unnamed genospecies. DNA-DNA hybridization experiments confirmed that one of the latter represents a new taxonomic species for which the name Bradyrhizobium canariense is proposed. B. canariense populations experience homologous recombination at housekeeping loci, but are sexually isolated from sympatric B. japonicum bv. genistearum strains in soils of the Canary Islands. B. canariense strains are highly acid-tolerant, nodulate diverse legumes in the tribes Genisteae and Loteae, but not Glycine species, whereas acid-sensitive B. japonicum soybean isolates such as USDA 6(T) and USDA 110 do not nodulate genistoid legumes. Based on host-range experiments and phylogenetic analyses of symbiotic nifH and nodC sequences, the biovarieties genistearum and glycinearum for the genistoid legume and soybean isolates, respectively, were proposed. B. canariense bv. genistearum strains display an overlapped host range with B. japonicum bv. genistearum isolates, both sharing monophyletic nifH and nodC alleles, possibly due to the lateral transfer of a conjugative chromosomal symbiotic island across species. B. canariense is the sister species of B. japonicum, as inferred from a maximum-likelihood Bradyrhizobium species phylogeny estimated from congruent glnII+recA sequence partitions, which resolves eight species clades. In addition to the currently described species, this phylogeny uncovered the novel Bradyrhizobium genospecies alpha and beta and the photosynthetic strains as independent evolutionary lineages. The type strain for B. canariense is BTA-1(T) (=ATCC BAA-1002(T)=LMG 22265(T)=CFNE 1008(T)).}, }
@article {pmid15774024, year = {2005}, author = {Salzberg, SL and Dunning Hotopp, JC and Delcher, AL and Pop, M and Smith, DR and Eisen, MB and Nelson, WC}, title = {Serendipitous discovery of Wolbachia genomes in multiple Drosophila species.}, journal = {Genome biology}, volume = {6}, number = {3}, pages = {R23}, pmid = {15774024}, issn = {1474-760X}, support = {R01 LM006845/LM/NLM NIH HHS/United States ; R01 LM007938/LM/NLM NIH HHS/United States ; R01-LM007938/LM/NLM NIH HHS/United States ; R01-LM06845/LM/NLM NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Drosophila/*microbiology ; Gene Transfer, Horizontal ; *Genome, Bacterial ; Genomics ; Molecular Sequence Data ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Wolbachia/classification/*genetics ; }, abstract = {BACKGROUND: The Trace Archive is a repository for the raw, unanalyzed data generated by large-scale genome sequencing projects. The existence of this data offers scientists the possibility of discovering additional genomic sequences beyond those originally sequenced. In particular, if the source DNA for a sequencing project came from a species that was colonized by another organism, then the project may yield substantial amounts of genomic DNA, including near-complete genomes, from the symbiotic or parasitic organism.<br><br>RESULTS: By searching the publicly available repository of DNA sequencing trace data, we discovered three new species of the bacterial endosymbiont Wolbachia pipientis in three different species of fruit fly: Drosophila ananassae, D. simulans, and D. mojavensis. We extracted all sequences with partial matches to a previously sequenced Wolbachia strain and assembled those sequences using customized software. For one of the three new species, the data recovered were sufficient to produce an assembly that covers more than 95% of the genome; for a second species the data produce the equivalent of a 'light shotgun' sampling of the genome, covering an estimated 75-80% of the genome; and for the third species the data cover approximately 6-7% of the genome.<br><br>CONCLUSIONS: The results of this study reveal an unexpected benefit of depositing raw data in a central genome sequence repository: new species can be discovered within this data. The differences between these three new Wolbachia genomes and the previously sequenced strain revealed numerous rearrangements and insertions within each lineage and hundreds of novel genes. The three new genomes, with annotation, have been deposited in GenBank.}, }
@article {pmid15772379, year = {2005}, author = {Belda, E and Moya, A and Silva, FJ}, title = {Genome rearrangement distances and gene order phylogeny in gamma-Proteobacteria.}, journal = {Molecular biology and evolution}, volume = {22}, number = {6}, pages = {1456-1467}, doi = {10.1093/molbev/msi134}, pmid = {15772379}, issn = {0737-4038}, mesh = {Biological Evolution ; Escherichia coli/genetics ; Evolution, Molecular ; Gammaproteobacteria/*genetics ; Gene Order ; Gene Transfer, Horizontal ; Genome ; *Genome, Bacterial ; Models, Genetic ; Models, Theoretical ; Phylogeny ; Time Factors ; Yersinia pestis/genetics ; }, abstract = {Genome rearrangements have been studied in 30 gamma-proteobacterial complete genomes by comparing the order of a reduced set of genes on the chromosome. This set included those genes fulfilling several characteristics, the main ones being that an ortholog was present in every genome and that none of them had been acquired by horizontal gene transfer. Genome rearrangement distances were estimated based on either the number of breakpoints or the minimal number of inversions separating two genomes. Breakpoint and inversion distances were highly correlated, indicating that inversions were the main type of rearrangement event in gamma-Proteobacteria. In general, the progressive increase in sequence-based distances between genome pairs was associated with the increase in their rearrangement-based distances but with several groups of distances not following this pattern. Compared with free-living enteric bacteria, the lineages of Pasteurellaceae were evolving, on average, to relatively higher rates of between 2.02 and 1.64, while the endosymbiotic bacterial lineages of Buchnera aphidicola and Wigglesworthia glossinidia were evolving at moderately higher rates of 1.38 and 1.35, respectively. Because we know that the rearrangement rate in the Bu. aphidicola lineage was close to zero during the last 100-150 Myr of evolution, we deduced that a much higher rate took place in the first period of lineage evolution after the divergence of the Escherichia coli lineage. On the other hand, the lineage of the endosymbiont Blochmannia floridanus did present an almost identical rate to free-living enteric bacteria, indicating that the increase in the genome rearrangement rate is not a general change associated with bacterial endosymbiosis. Phylogenetic reconstruction based on rearrangement distances showed a different topology from the one inferred by sequence information. This topology broke the proposed monophyly of the three endosymbiotic lineages and placed Bl. floridanus as a closer relative to E. coli than Yersinia pestis. These results indicate that the phylogeny of these insect endosymbionts is still an open question that will require the development of specific phylogenetic methods to confirm whether the sisterhood of the three endosymbiotic lineages is real or a consequence of a long-branch attraction phenomenon.}, }
@article {pmid15755914, year = {2005}, author = {Gadelha, C and Wickstead, B and de Souza, W and Gull, K and Cunha-e-Silva, N}, title = {Cryptic paraflagellar rod in endosymbiont-containing kinetoplastid protozoa.}, journal = {Eukaryotic cell}, volume = {4}, number = {3}, pages = {516-525}, pmid = {15755914}, issn = {1535-9778}, mesh = {Amino Acid Sequence ; Animals ; Cell Movement/*physiology ; Crithidia/classification/*cytology/*genetics/metabolism ; Cytoskeleton/metabolism/ultrastructure ; Flagella/genetics/metabolism/*ultrastructure ; Genetic Complementation Test ; Kinetoplastida ; Leishmania mexicana/classification/genetics/metabolism ; Molecular Sequence Data ; Organelles/genetics/metabolism/*ultrastructure ; Phylogeny ; Protozoan Proteins/genetics/*metabolism ; Sequence Alignment ; }, abstract = {Cilia and flagella are central to many biological processes in a diverse range of organisms. The kinetoplastid protozoa are very appealing models for the study of flagellar function, particularly in the light of the availability of extensive trypanosomatid genome information. In addition to the highly conserved 9 + 2 axoneme, the kinetoplastid flagellum contains a characteristic paraflagellar rod structure (PFR). The PFR is necessary for full motility and provides support for metabolic regulators that may influence flagellar beating. However, there is an intriguing puzzle: one clade of endosymbiont-containing kinetoplastids apparently lack a PFR yet are as motile as species that possess a PFR and are able to attach to the invertebrate host epithelia. We investigated how these organisms are able to locomote despite the apparent lack of PFR. Here we have identified a PFR1 gene in the endosymbiont-bearing trypanosome Crithidia deanei. This gene is expressed in C. deanei and is able to partially complement a pfr1 null mutation in Leishmania mexicana cells, demonstrating that the encoded protein is functional. Careful reexamination of C. deanei flagellar ultrastructure revealed a greatly reduced PFR missed by many previous analyses. This affirms the PFR as a canonical organelle of kinetoplastids. Moreover, although PFR proteins have been conserved in evolution, primary sequence differences contribute to particular PFR morphotypes characteristic of different kinetoplastid species.}, }
@article {pmid15752179, year = {2005}, author = {Behbahani, A and Dutton, TJ and Davies, N and Townson, H and Sinkins, SP}, title = {Population differentiation and Wolbachia phylogeny in mosquitoes of the Aedes scutellaris group.}, journal = {Medical and veterinary entomology}, volume = {19}, number = {1}, pages = {66-71}, doi = {10.1111/j.0269-283X.2005.00542.x}, pmid = {15752179}, issn = {0269-283X}, mesh = {Aedes/genetics/*microbiology ; Animals ; Genetic Variation ; Genotype ; Phylogeny ; Wolbachia/*genetics/physiology ; }, abstract = {Mosquito species of the Aedes (Stegomyia) scutellaris (Walker) group (Diptera: Culicidae) are distributed across many islands of the South Pacific and include major regional vectors of filariasis, such as Aedes polynesiensis (Marks). Analysis of populations of Ae. polynesiensis at the extremes of its range, from Fiji and from Moorea, French Polynesia, using the rDNA ITS2 (internal transcribed spacer 2) region and six microsatellite markers showed considerable genetic differentiation between them (F(ST) = 0.298-0.357). Phylogenetic analysis of the Wolbachia endosymbionts in three members of the complex revealed that based on the wsp gene they are all very similar and belong to the Mel subgroup of the A clade, closely related to the Wolbachia strain present in the gall wasp Callyrhytis glandium (Giraud) (Hymenoptera: Cynipidae). By contrast they are only distantly related to the A-clade Wolbachia in Aedes albopictus (Skuse), a species closely allied to the Ae. scutellaris group. There was very low differentiation between the Wolbachia in the Moorea and Fiji populations of Ae. polynesiensis.}, }
@article {pmid15746350, year = {2005}, author = {Stingl, U and Radek, R and Yang, H and Brune, A}, title = {"Endomicrobia": cytoplasmic symbionts of termite gut protozoa form a separate phylum of prokaryotes.}, journal = {Applied and environmental microbiology}, volume = {71}, number = {3}, pages = {1473-1479}, pmid = {15746350}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification/ultrastructure ; Base Sequence ; Cellulose/metabolism ; Cloning, Molecular ; Cytoplasm/microbiology ; DNA, Bacterial/genetics ; Digestive System/metabolism/microbiology/parasitology ; Eukaryota/*microbiology ; In Situ Hybridization, Fluorescence ; Isoptera/metabolism/*microbiology/*parasitology ; Lignin/metabolism ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Prokaryotic Cells ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Terminology as Topic ; }, abstract = {Lignocellulose digestion by wood-feeding termites depends on the mutualistic interaction of unusual, flagellate protists located in their hindgut. Most of the flagellates harbor numerous prokaryotic endosymbionts of so-far-unknown identity and function. Using a full-cycle molecular approach, we show here that the endosymbionts of the larger gut flagellates of Reticulitermes santonensis belong to the so-called termite group 1 (TG-1) bacteria, a group of clones previously obtained exclusively from gut homogenates of Reticulitermes speratus that are only distantly related to other bacteria and are considered a novel bacterial phylum based on their 16S rRNA gene sequences. Fluorescence in situ hybridization with specifically designed oligonucleotide probes confirmed that TG-1 bacteria are indeed located within the flagellate cells and demonstrated that Trichonympha agilis (Hypermastigida) and Pyrsonympha vertens (Oxymonadida) harbor phylogenetically distinct populations of symbionts (<95% sequence similarity). Transmission electron microscopy revealed that the symbionts are small, spindle-shaped cells (0.6 microm in length and 0.3 microm in diameter) surrounded by two membranes and located within the cytoplasm of their hosts. The symbionts of the two flagellates are described as candidate species in the candidate genus "Endomicrobium." Moreover, we provide evidence that the members of the TG-1 phylum, for which we propose the candidate name "Endomicrobia," are phylogenetically extremely diverse and are present in and also restricted to the guts of all lower termites and wood-feeding cockroaches of the genus Cryptocercus, the only insects that are in an exclusive, obligately mutualistic association with such unique cellulose-fermenting protists.}, }
@article {pmid15741997, year = {2005}, author = {Lattorff, HM and Moritz, RF and Fuchs, S}, title = {A single locus determines thelytokous parthenogenesis of laying honeybee workers (Apis mellifera capensis).}, journal = {Heredity}, volume = {94}, number = {5}, pages = {533-537}, doi = {10.1038/sj.hdy.6800654}, pmid = {15741997}, issn = {0018-067X}, mesh = {Animals ; Bees/*genetics ; Biological Evolution ; Eggs ; Female ; *Genetic Linkage ; Genotype ; Parthenogenesis/*genetics ; Quantitative Trait, Heritable ; }, abstract = {The evolution and maintenance of parthenogenetic species are a puzzling issue in evolutionary biology. Although the genetic mechanisms that act to restore diploidy are well studied, the underlying genes that cause the switch from sexual reproduction to parthenogenesis have not been analysed. There are several species that are polymorphic for sexual and parthenogenetic reproduction, which may have a genetic basis. We use the South African honeybee subspecies Apis mellifera capensis to analyse the genetic control of thelytoky (asexual production of female workers). Due to the caste system of honeybees, it is possible to establish classical backcrosses using sexually reproducing queens and drones of both arrhenotokous and thelytokous subspecies, and to score the frequency of parthenogenesis in the resulting workers. We found Mendelian segregation for thelytoky of egg-laying workers, which appears to be controlled by a single major gene (th). The segregation pattern indicates a recessive allele causing thelytoky. We found no evidence for maternal transmission of bacterial endosymbionts controlling parthenogenesis. Thelytokous parthenogenesis of honeybee workers appears to be a classical qualitative trait, because we did not observe mixed parthenogenesis (amphitoky), which might be expected in the case of multi-locus inheritance.}, }
@article {pmid15716086, year = {2005}, author = {Pérez-Brocal, V and Latorre, A and Gil, R and Moya, A}, title = {Comparative analysis of two genomic regions among four strains of Buchnera aphidicola, primary endosymbiont of aphids.}, journal = {Gene}, volume = {345}, number = {1}, pages = {73-80}, doi = {10.1016/j.gene.2004.11.021}, pmid = {15716086}, issn = {0378-1119}, mesh = {Animals ; Aphids/*microbiology ; Base Composition/genetics ; Buchnera/*genetics ; Chromosome Mapping ; DNA, Bacterial/chemistry/genetics ; DNA, Intergenic/genetics ; Genes, Bacterial/genetics ; *Genome, Bacterial ; Molecular Sequence Data ; Sequence Analysis, DNA ; Species Specificity ; Symbiosis ; }, abstract = {Preliminary analysis of two selected genomic regions of Buchnera aphidicola BCc, the primary endosymbiont of the cedar aphid Cinara cedri, has revealed a number of interesting features when compared with the corresponding homologous regions of the three B. aphidicola genomes previously sequenced, that are associated with different aphid species. Both regions exhibit a significant reduction in length and gene number in B. aphidicola BCc, as it could be expected since it possess the smallest bacterial genome. However, the observed genome reduction is not even in both regions, as it appears to be dependent on the nature of their gene content. The region fpr-trxA, that contains mainly metabolic genes, has lost almost half of its genes (45.6%) and has reduced 52.9% its length. The reductive process in the region rrl-aroK, that contains mainly ribosomal protein genes, is less dramatic, since it has lost 9.3% of genes and has reduced 15.5% of its length. Length reduction is mainly due to the loss of protein-coding genes, not to the shortening of ORFs or intergenic regions. In both regions, G+C content is about 4% lower in BCc than in the other B. aphidicola strains. However, when only conserved genes and intergenic regions of the four B. aphidicola strains are compared, the G+C reduction is higher in the fpr-trxA region.}, }
@article {pmid15715838, year = {2005}, author = {Downie, DA and Gullan, PJ}, title = {Phylogenetic congruence of mealybugs and their primary endosymbionts.}, journal = {Journal of evolutionary biology}, volume = {18}, number = {2}, pages = {315-324}, doi = {10.1111/j.1420-9101.2004.00834.x}, pmid = {15715838}, issn = {1010-061X}, mesh = {Animals ; Bacteria/*genetics ; DNA, Ribosomal/genetics ; Hemiptera/*genetics/*microbiology ; Likelihood Functions ; Models, Genetic ; Peptide Elongation Factor 1/genetics ; *Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Tight interactions between unrelated organisms such as is seen in plant-insect, host-parasite, or host-symbiont associations may lead to speciation of the smaller partners when their hosts speciate. Totally congruent phylogenies of interacting taxa have not been observed often but a number of studies have provided evidence that various hemipteran insect taxa and their primary bacterial endosymbionts share phylogenetic histories. Like other hemipterans, mealybugs (Pseudococcidae) harbour multiple intracellular bacterial symbionts, which are thought to be strictly vertically inherited, implying codivergence of hosts and symbionts. Here, robust estimates of phylogeny were generated from four fragments of three nuclear genes for mealybugs of the subfamily Pseudococcinae, and a substantial fragment of the 16S-23S rDNA of their P-endosymbionts. Phylogenetic congruence was highly significant, with 75% of nodes on the two trees identical, and significant correlation of branch lengths indicated coincident timing of cladogenesis. It is suggested that the low level of observed incongruence was influenced by uncertainty in phylogenetic estimation, but evolutionary outcomes other than congruence, including host shifts, could not be rejected.}, }
@article {pmid15710433, year = {2005}, author = {Mounsey, KE and Holt, DC and Fischer, K and Kemp, DJ and Currie, BJ and Walton, SF}, title = {Analysis of Sarcoptes scabiei finds no evidence of infection with Wolbachia.}, journal = {International journal for parasitology}, volume = {35}, number = {2}, pages = {131-135}, doi = {10.1016/j.ijpara.2004.11.007}, pmid = {15710433}, issn = {0020-7519}, mesh = {Animals ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/genetics ; Databases, Nucleic Acid ; Humans ; Polymerase Chain Reaction/methods ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae Infections/genetics/veterinary ; Sarcoptes scabiei/*genetics/parasitology ; Scabies/*genetics/parasitology ; Wolbachia/*genetics ; }, abstract = {The endosymbiont Wolbachia has been detected in a range of filarial nematodes and parasitic mites and is known to affect host reproductive compatibility and potentially evolutionary processes. PCR of Wolbachia surface protein (wsp), ftsZ and 16SrRNA genes from individual Sarcoptes scabiei mites obtained from a series of individual hosts, and database searches of an S. scabiei var. hominis EST library failed to detect Wolbachia genes. Therefore, Wolbachia appears not to be involved in the genetic subdivision observed between varieties of host-associated S. scabiei or, involved in the inflammatory disease pathogenesis of scabies unlike its activity in filarial infection.}, }
@article {pmid15702253, year = {2005}, author = {Baumann, L and Baumann, P}, title = {Cospeciation between the primary endosymbionts of mealybugs and their hosts.}, journal = {Current microbiology}, volume = {50}, number = {2}, pages = {84-87}, pmid = {15702253}, issn = {0343-8651}, mesh = {Animals ; Base Composition ; Base Sequence ; Betaproteobacteria/*genetics ; Cytochromes b/genetics ; DNA/chemistry/genetics ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; Genes, Insect ; Hemiptera/*genetics/*microbiology ; Host-Parasite Interactions/genetics ; Molecular Sequence Data ; Phylogeny ; Plants/*microbiology/*parasitology ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {Mealybugs have an association with prokaryotic endosymbionts that are located in specialized cells called bacteriocytes. In order to compare the phylogeny of the host with that of the previously published phylogeny of the endosymbionts, 3.1 to 3.2 kilobase DNA fragments containing mitochondrial cytB (part), nd1,16S ribosomal DNA(rDNA), and 12S rDNA (part) were amplified and sequenced. A phylogenetic analysis of the data and a comparison with the trees obtained from endosymbiont genes and host 18S and 28S rDNA indicated that all the trees were similar. This result is consistent with an infection of a mealybug ancestor with a precursor of the endosymbiont followed by the vertical transmission of the endosymbiont to progeny. Comparison of the guanine + cytosine (G + C) contents of the mealybug mitochondrial genes with the same genes from other members of Sternorrhyncha and Arthropoda indicated that the mealybug genes had unusually low G + C contents in their DNAs (10.2 to 11.1 mol%).}, }
@article {pmid15693943, year = {2005}, author = {Dufresne, A and Garczarek, L and Partensky, F}, title = {Accelerated evolution associated with genome reduction in a free-living prokaryote.}, journal = {Genome biology}, volume = {6}, number = {2}, pages = {R14}, pmid = {15693943}, issn = {1474-760X}, mesh = {Adaptation, Physiological ; Amino Acid Substitution ; Bacterial Proteins/genetics ; Base Sequence ; DNA Repair ; *Evolution, Molecular ; *Genome, Bacterial ; Genomic Instability ; Genomics ; Molecular Sequence Data ; Prochlorococcus/*genetics ; Synteny ; }, abstract = {BACKGROUND: Three complete genomes of Prochlorococcus species, the smallest and most abundant photosynthetic organism in the ocean, have recently been published. Comparative genome analyses reveal that genome shrinkage has occurred within this genus, associated with a sharp reduction in G+C content. As all examples of genome reduction characterized so far have been restricted to endosymbionts or pathogens, with a host-dependent lifestyle, the observed genome reduction in Prochlorococcus is the first documented example of such a process in a free-living organism.<br><br>RESULTS: Our results clearly indicate that genome reduction has been accompanied by an increased rate of protein evolution in P. marinus SS120 that is even more pronounced in P. marinus MED4. This acceleration has affected every functional category of protein-coding genes. In contrast, the 16S rRNA gene seems to have evolved clock-like in this genus. We observed that MED4 and SS120 have lost several DNA-repair genes, the absence of which could be related to the mutational bias and the acceleration of amino-acid substitution.<br><br>CONCLUSIONS: We have examined the evolutionary mechanisms involved in this process, which are different from those known from host-dependent organisms. Indeed, most substitutions that have occurred in Prochlorococcus have to be selectively neutral, as the large size of populations imposes low genetic drift and strong purifying selection. We assume that the major driving force behind genome reduction within the Prochlorococcus radiation has been a selective process favoring the adaptation of this organism to its environment. A scenario is proposed for genome evolution in this genus.}, }
@article {pmid15681877, year = {2005}, author = {Rajan, TV}, title = {The eye does not see what the mind does not know: the bacterium in the worm.}, journal = {Perspectives in biology and medicine}, volume = {48}, number = {1}, pages = {31-41}, doi = {10.1353/pbm.2005.0015}, pmid = {15681877}, issn = {0031-5982}, mesh = {Animals ; Anti-Bacterial Agents/therapeutic use ; Chlamydia/drug effects/isolation &amp; purification/pathogenicity ; Culicidae/parasitology ; Elephantiasis, Filarial/drug therapy/*parasitology ; *Host-Parasite Interactions ; Humans ; India ; Molecular Biology ; Nematoda ; *Symbiosis ; United States ; Wolbachia/drug effects/isolation &amp; purification/*pathogenicity ; Wuchereria bancrofti/microbiology/*parasitology ; }, abstract = {Symbiotic relationships underlie the evolutionary success of many different life forms. The filarial worms are long, slender nematode parasites that cause considerable pathology in large segments of the world's population. About 25 years ago, investigators first reported the presence of bacterial organisms living inside these parasitic worms. Recent molecular biological studies have indicated that these bacteria belong to the genus Wolbachia, members of which have been known to be associated with numerous species of insects. Elimination of the Wolbachia from the nematodes (by, for instance, treatment with broad spectrum antibiotics) results in profound disturbances in the physiology of the latter, including a complete block in reproduction. This observation, taken together with the fact that every individual worm examined to date contains Wolbachia, validates the classification of the latter as "endosymbionts." Many studies indicate that the Wolbachia may also play an important role in the pathology caused by the nematode worms, and that it might be possible to target therapy against the Wolbachia to treat the filarial disease. Intriguingly, the intense recent interest in Wolbachia is in complete contrast with the virtually complete indifference evoked by the original discovery of these organisms.}, }
@article {pmid15666722, year = {2004}, author = {McEwan, ML and Keeling, PJ}, title = {HSP90, tubulin and actin are retained in the tertiary endosymbiont genome of Kryptoperidinium foliaceum.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {6}, pages = {651-659}, doi = {10.1111/j.1550-7408.2004.tb00604.x}, pmid = {15666722}, issn = {1066-5234}, mesh = {Actins/*genetics ; Animals ; Base Composition ; DNA, Protozoan/chemistry/isolation &amp; purification ; Diatoms/genetics ; Dinoflagellida/*genetics ; Evolution, Molecular ; Genome, Protozoan ; HSP90 Heat-Shock Proteins/*genetics ; Molecular Sequence Data ; Phylogeny ; Protozoan Proteins/*genetics ; Sequence Analysis, DNA ; Sequence Homology ; Symbiosis/genetics ; Tubulin/*genetics ; }, abstract = {The dinoflagellate Kryptoperidinium foliaceum has replaced its ancestral peridinin-containing plastid with a fucoxanthin-containing diatom plastid via tertiary endosymbiosis. The diatom endosymbiont of K. foliaceum is much less reduced than well-studied endosymbiotic intermediates, such as cryptophytes and chlorarachniophytes, where relict nuclear genomes are retained in secondary endosymbionts. The K. foliaceum endosymbiont retains a prominent nucleus, multiple four-membrane plastids, and mitochondria, all within a relatively large volume of cytoplasm that is separated from the host cytoplasm by a single membrane. Here we report the first protein-coding gene sequences from the K. foliaceum endosymbiont and host nuclear genomes. We have characterised genes for nucleus-encoded cytosolic proteins, actin (from endosymbiont), alpha-tubulin (from both), beta-tubulin (from host), and HSP90 (from both), in addition to homologues from pennate diatoms Nitzschia thermalis and Phaeodactylum tricornutum. Phylogenetic reconstruction shows that the actin is diatom-derived, the beta-tubulin dinoflagellate-derived, while both diatom- and dinoflagellate-derived alpha-tubulin and HSP90 genes were found. The base composition biases of these genes co-varied with their phylogenetic position, suggesting that the genes still reside in their respective genomes. The presence of these genes implies they are still functional and more generally indicates that the endosymbiont is less genetically reduced than those of cryptophytes or chlorarachniophytes, raising the interesting question of whether any genes have transferred between the two nuclear genomes.}, }
@article {pmid15659174, year = {2005}, author = {MacLellan, SR and Smallbone, LA and Sibley, CD and Finan, TM}, title = {The expression of a novel antisense gene mediates incompatibility within the large repABC family of alpha-proteobacterial plasmids.}, journal = {Molecular microbiology}, volume = {55}, number = {2}, pages = {611-623}, doi = {10.1111/j.1365-2958.2004.04412.x}, pmid = {15659174}, issn = {0950-382X}, mesh = {Agrobacterium tumefaciens/genetics ; Alphaproteobacteria/*genetics ; Bacterial Proteins/genetics/*metabolism ; Base Sequence ; DNA Helicases/genetics ; DNA, Intergenic/*genetics ; DNA-Binding Proteins/genetics ; Escherichia coli/genetics ; *Gene Expression Regulation, Bacterial ; Molecular Sequence Data ; Mutation ; Plasmids/*genetics ; Promoter Regions, Genetic ; RNA, Antisense/genetics/*metabolism ; Replicon/*genetics ; Sinorhizobium meliloti/genetics/metabolism ; Symbiosis ; Trans-Activators/genetics ; }, abstract = {Large extrachromosomal replicons in many members of the alpha-proteobacteria encode genes that are required for plant or animal pathogenesis or symbiosis. Most of these replicons encode repABC genes that control their replication and faithful segregation during cell division. In addition to its chromosome, the plant endosymbiont Sinorhizobium meliloti also maintains the 1.4 Mb pSymA and 1.7 Mb pSymB symbiotic megaplasmids both of which are repABC-type replicons. In all repABC loci that have been characterized, an apparently untranslated intergenic region between the repB and repC genes encodes a strong incompatibility determinant (referred to as incalpha). Here we report the isolation of mutations within the incalpha regions of pSymA and pSymB that eliminate incompatibility. These mutations map to and inactivate a promoter in the intergenic region that drives the expression of an approximately 56 nucleotide untranslated RNA molecule that mediates incompatibility. This gene, that we have named incA, is transcribed antisense to the repABC genes. Our analysis suggests that the incA gene is conserved in repABC loci from a diverse spectrum of bacteria.}, }
@article {pmid15648826, year = {2004}, author = {Ward, ME and Shields, JD and Van Dover, CL}, title = {Parasitism in species of Bathymodiolus (Bivalvia: Mytilidae) mussels from deep-sea seep and hydrothermal vents.}, journal = {Diseases of aquatic organisms}, volume = {62}, number = {1-2}, pages = {1-16}, doi = {10.3354/dao062001}, pmid = {15648826}, issn = {0177-5103}, mesh = {Age Factors ; Animals ; Atlantic Ocean ; *Bacteria ; Bivalvia/*parasitology ; *Ecosystem ; Hemocytes/cytology ; Histological Techniques ; Host-Parasite Interactions ; Inclusion Bodies/microbiology ; Inclusion Bodies, Viral/virology ; Population Dynamics ; Reproduction/physiology ; Species Specificity ; *Viruses ; }, abstract = {Bivalve species, especially mussels, are biomass dominants in many deep-sea chemosynthetic ecosystems. As in shallow-water environments, parasites are likely to be important factors in the population dynamics of bivalve communities in chemosynthetic ecosystems, but there has been little study of parasitism in deep-sea seep or vent molluscs. In this study, parasite types, diversity, prevalence, infection density and non-infectious indicators of stress or disease as related to host age, reproductive condition, and endosymbiont density were assessed in mussels (Bathymodiolus heckerae) from 2 seep sites and mussels (B. puteoserpentis) from 2 vent sites. We identified 10 microbial or parasitic agents in histological sections. Parasite types included 3 viral-like gut inclusions, 2 rickettsia-like gill inclusions, a rickettsia-like mantle inclusion, a bacterial gill-rosette, a chlamydia-like gut inclusion, gill-dwelling ciliates, and an unidentified inclusion in gut tissues. Parasite species richness was greater in seep mussels than in vent mussels, with the seep mussels possessing 9 types of parasites compared to 2 in the vent mussels. One of the viral-like inclusions infecting the seep mussel B. heckerae was pathogenic, causing lysis of the digestive tubules. The prevalence and intensity of infection by this pathogen were greater in hosts with shell lengths less than 100 mm. Mussels from all 4 sites also exhibited intense infiltration of tissues and blood spaces by enlarged hemocytes. Hemocytic infiltration (hemocytosis) showed variable degrees of severity that were not associated with other host factors examined.}, }
@article {pmid15648724, year = {2004}, author = {Takishita, K and Ishida, K and Maruyama, T}, title = {Phylogeny of nuclear-encoded plastid-targeted GAPDH gene supports separate origins for the peridinin- and the fucoxanthin derivative-containing plastids of dinoflagellates.}, journal = {Protist}, volume = {155}, number = {4}, pages = {447-458}, doi = {10.1078/1434461042650325}, pmid = {15648724}, issn = {1434-4610}, mesh = {Amino Acid Sequence ; Animals ; Carotenoids/analysis ; Dinoflagellida/chemistry/classification/*genetics ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Molecular Sequence Data ; *Phylogeny ; Plastids/chemistry ; Sequence Alignment ; Xanthophylls/analysis ; }, abstract = {Although most photosynthetic dinoflagellates have plastids with peridinin, the three dinoflagellate genera Karenia, Karlodinium, and Takayama possess anomalously pigmented plastids that contain fucoxanthin and its derivatives (19'-hexanoyloxy-fucoxanthin and 19'-butanoyloxy-fucoxanthin) instead of the peridinin. This pigment composition is similar to that of haptophytes. All peridinin-containing dinoflagellates investigated so far have at least two types of glyceraldehyde-3-phosphate dehydrogenase (GAPDH): cytosolic and plastid-targeted forms. In the present study, we cloned and sequenced genes encoding cytosolic and plastid-targeted GAPDH proteins from three species of the fucoxanthin derivative-containing dinoflagellates. Based on the molecular phylogeny, the plastid-targeted GAPDH genes of the fucoxanthin derivative-containing dinoflagellates were closely related to those of haptophyte algae rather than to the peridinin-containing dinoflagellates, while one of several cytosolic versions from the peridinin- and the fucoxanthin derivative-containing dinoflagellates are closely related to each other. Considering a previously reported theory that the plastid-targeted GAPDH from the peridinin-containing dinoflagellates originated by a gene duplication of the cytosolic form before the splitting of the dinoflagellate lineage, it is highly likely that the plastid-targeted GAPDH gene of the peridinin-containing dinoflagellates is original in this algal group and that in the fucoxanthin-containing dinoflagellates, the original plastid-targeted GAPDH was replaced by that of a haptophyte endosymbiont during a tertiary endosymbiosis. The present results strongly support the hypothesis that the plastids of the peridinin- and the fucoxanthin derivative-containing dinoflagellates are of separate origin.}, }
@article {pmid15634195, year = {2005}, author = {Kilian, O and Kroth, PG}, title = {Identification and characterization of a new conserved motif within the presequence of proteins targeted into complex diatom plastids.}, journal = {The Plant journal : for cell and molecular biology}, volume = {41}, number = {2}, pages = {175-183}, doi = {10.1111/j.1365-313X.2004.02294.x}, pmid = {15634195}, issn = {0960-7412}, mesh = {Algal Proteins/*genetics/metabolism ; Amino Acid Motifs ; Conserved Sequence ; Diatoms/*genetics/metabolism ; Models, Biological ; Plastids/*metabolism ; Protein Sorting Signals ; Protein Transport ; Recombinant Fusion Proteins/metabolism ; }, abstract = {Several groups of algae evolved by secondary endocytobiosis, which is defined as the uptake of a eukaryotic alga into a eukaryotic host cell and the subsequent transformation of the endosymbiont into an organelle. Due to this explicit evolutionary history such algae possess plastids that are surrounded by either three or four membranes. Protein targeting into plastids of these organisms depends on N-terminal bipartite presequences consisting of a signal and a transit peptide domain. This suggests that different protein targeting systems may have been combined during establishment of secondary endocytobiosis to enable the transport of proteins into the plastids. Here we demonstrate the presence of an apparently new type of transport into diatom plastids. We analyzed protein targeting into the plastids of diatoms and identified a conserved amino acid sequence motif within plastid preprotein targeting sequences. We expressed several diatom plastid presequence:GFP fusion proteins with or without modifications within that motif in the diatom Phaeodactylum tricornutum and found that a single conserved phenylalanine is crucial for protein transport into the diatom plastids in vivo, thus indicating the presence of a so far unknown new type of targeting signal. We also provide experimental data about the minimal requirements of a diatom plastid targeting presequence and demonstrate that the signal peptides of plastid preproteins and of endoplasmic reticulum-targeted preproteins in diatoms are functionally equivalent. Furthermore we show that treatment of the cells with Brefeldin A arrests protein transport into the diatom plastids suggesting that a vesicular transport step within the plastid membranes may occur.}, }
@article {pmid15616514, year = {2005}, author = {Imaizumi-Anraku, H and Takeda, N and Charpentier, M and Perry, J and Miwa, H and Umehara, Y and Kouchi, H and Murakami, Y and Mulder, L and Vickers, K and Pike, J and Downie, JA and Wang, T and Sato, S and Asamizu, E and Tabata, S and Yoshikawa, M and Murooka, Y and Wu, GJ and Kawaguchi, M and Kawasaki, S and Parniske, M and Hayashi, M}, title = {Plastid proteins crucial for symbiotic fungal and bacterial entry into plant roots.}, journal = {Nature}, volume = {433}, number = {7025}, pages = {527-531}, doi = {10.1038/nature03237}, pmid = {15616514}, issn = {1476-4687}, mesh = {Alleles ; Amino Acid Sequence ; *Bacterial Physiological Phenomena ; Calcium Signaling ; DNA, Complementary/genetics ; Fungi/*physiology ; Genes, Plant/genetics ; Lotus/cytology/genetics/*metabolism/microbiology ; Models, Molecular ; Molecular Sequence Data ; Mutation/genetics ; Phenotype ; Phylogeny ; Plant Proteins/chemistry/genetics/*metabolism ; Plant Roots/cytology/genetics/metabolism/*microbiology ; Plastids/genetics/*metabolism ; Protein Transport ; RNA, Messenger/genetics/metabolism ; Symbiosis/*physiology ; }, abstract = {The roots of most higher plants form arbuscular mycorrhiza, an ancient, phosphate-acquiring symbiosis with fungi, whereas only four related plant orders are able to engage in the evolutionary younger nitrogen-fixing root-nodule symbiosis with bacteria. Plant symbioses with bacteria and fungi require a set of common signal transduction components that redirect root cell development. Here we present two highly homologous genes from Lotus japonicus, CASTOR and POLLUX, that are indispensable for microbial admission into plant cells and act upstream of intracellular calcium spiking, one of the earliest plant responses to symbiotic stimulation. Surprisingly, both twin proteins are localized in the plastids of root cells, indicating a previously unrecognized role of this ancient endosymbiont in controlling intracellular symbioses that evolved more recently.}, }
@article {pmid15615594, year = {2004}, author = {Greub, G and Collyn, F and Guy, L and Roten, CA}, title = {A genomic island present along the bacterial chromosome of the Parachlamydiaceae UWE25, an obligate amoebal endosymbiont, encodes a potentially functional F-like conjugative DNA transfer system.}, journal = {BMC microbiology}, volume = {4}, number = {}, pages = {48}, pmid = {15615594}, issn = {1471-2180}, mesh = {Acanthamoeba/microbiology ; Animals ; Base Composition/genetics ; Chlamydiales/classification/*genetics ; Chromosomes, Bacterial/*genetics ; Computational Biology/methods ; Conjugation, Genetic/*genetics ; DNA, Bacterial/genetics ; Gene Order/genetics ; Genomic Islands/*genetics ; Operon/*genetics ; Phylogeny ; Symbiosis ; }, abstract = {BACKGROUND: The genome of Protochlamydia amoebophila UWE25, a Parachlamydia-related endosymbiont of free-living amoebae, was recently published, providing the opportunity to search for genomic islands (GIs).<br><br>RESULTS: On the residual cumulative G+C content curve, a G+C-rich 19-kb region was observed. This sequence is part of a 100-kb chromosome region, containing 100 highly co-oriented ORFs, flanked by two 17-bp direct repeats. Two identical gly-tRNA genes in tandem are present at the proximal end of this genetic element. Several mobility genes encoding transposases and bacteriophage-related proteins are located within this chromosome region. Thus, this region largely fulfills the criteria of GIs. The G+C content analysis shows that several modules compose this GI. Surprisingly, one of them encodes all genes essential for F-like conjugative DNA transfer (traF, traG, traH, traN, traU, traW, and trbC), involved in sex pilus retraction and mating pair stabilization, strongly suggesting that, similarly to the other F-like operons, the parachlamydial tra unit is devoted to DNA transfer. A close relatedness of this tra unit to F-like tra operons involved in conjugative transfer is confirmed by phylogenetic analyses performed on concatenated genes and gene order conservation. These analyses and that of gly-tRNA distribution in 140 GIs suggest a proteobacterial origin of the parachlamydial tra unit.<br><br>CONCLUSIONS: A GI of the UWE25 chromosome encodes a potentially functional F-like DNA conjugative system. This is the first hint of a putative conjugative system in chlamydiae. Conjugation most probably occurs within free-living amoebae, that may contain hundreds of Parachlamydia bacteria tightly packed in vacuoles. Such a conjugative system might be involved in DNA transfer between internalized bacteria. Since this system is absent from the sequenced genomes of Chlamydiaceae, we hypothesize that it was acquired after the divergence between Parachlamydiaceae and Chlamydiaceae, when the Parachlamydia-related symbiont was an intracellular bacteria. It suggests that this heterologous DNA was acquired from a phylogenetically-distant bacteria sharing an amoebal vacuole. Since Parachlamydiaceae are emerging agents of pneumonia, this GI might be involved in pathogenicity. In future, conjugative systems might be developed as genetic tools for Chlamydiales.}, }
@article {pmid15612632, year = {2004}, author = {Rodríguez-Navarro, DN and Camacho, M and Leidi, EO and Rivas, R and Velázquez, E}, title = {Phenotypic and genotypic characterization of rhizobia from diverse geographical origin that nodulate Pachyrhizus species.}, journal = {Systematic and applied microbiology}, volume = {27}, number = {6}, pages = {737-745}, doi = {10.1078/0723202042369839}, pmid = {15612632}, issn = {0723-2020}, mesh = {Bacterial Proteins/analysis/isolation &amp; purification ; Bradyrhizobium/chemistry/*classification/genetics/*isolation &amp; purification ; DNA Fingerprinting ; DNA, Bacterial/analysis/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry/isolation &amp; purification ; DNA, Ribosomal Spacer/chemistry/isolation &amp; purification ; Electrophoresis, Polyacrylamide Gel ; Genes, rRNA ; Lipopolysaccharides/analysis/isolation &amp; purification ; Molecular Sequence Data ; Pachyrhizus/*microbiology ; Phylogeny ; Proteome/analysis/isolation &amp; purification ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Random Amplified Polymorphic DNA Technique ; Sequence Analysis, DNA ; }, abstract = {Legumes from the genus Pachyrhizus, commonly known as yam bean, are cultivated in several countries from the American continent and constitute an alternative source for sustainable starch, oil and protein production. The endosymbionts of these legumes have been poorly studied although it is known that this legume is nodulated by fast and slow growing rhizobia. In this study we have analyzed a collection of strains isolated in several countries using different phenotypic and molecular methods. The results obtained by SDS-PAGE analysis, LPS profiling and TP-RAPD fingerprinting showed the high diversity of the strains analyzed, although all of them presented slow growth in yeast mannitol agar (YMA) medium. These results were confirmed using 16S-23S internal transcribed spacer (ITS) region and complete sequencing of the 16S rRNA gene, showing that most strains analyzed belong to different species of genus Bradyrhizobium. Three strains were closely related to B. elkanii and the rest of the strains were related to the phylogenetic group constituted by B. japonicum, B. liaoningense, B. yuanmingense and B. betae. These results support that the study of rhizobia nodulating unexplored legumes in different geographical locations will allow the discovery of new species able to establish legume symbioses.}, }
@article {pmid15612285, year = {2004}, author = {Marshall, JL}, title = {The Allonemobius-Wolbachia host-endosymbiont system: evidence for rapid speciation and against reproductive isolation driven by cytoplasmic incompatibility.}, journal = {Evolution; international journal of organic evolution}, volume = {58}, number = {11}, pages = {2409-2425}, doi = {10.1111/j.0014-3820.2004.tb00871.x}, pmid = {15612285}, issn = {0014-3820}, mesh = {Animals ; Base Sequence ; Cytoplasm/*microbiology ; DNA Primers ; DNA, Mitochondrial/genetics ; Fertilization/genetics ; *Genetic Variation ; Gryllidae/genetics/microbiology/*physiology ; Haplotypes/genetics ; Hybridization, Genetic ; Molecular Sequence Data ; *Phylogeny ; Reproduction/physiology ; Sequence Alignment ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; United States ; Wolbachia/*physiology ; }, abstract = {Evidence for the evolution of fertilization incompatibilities and rapid speciation can be biased by the occurrence of hybridization and reproductive endosymbionts such as Wolbachia. For example, patterns of mitochondrial DNA (mtDNA) variation can be obscured by mitotypes hitchhiking on extrachromosomal elements like Wolbachia, while such endosymbionts can also induce phenotypes that mirror the operation of intrinsic fertilization incompatibilities between species. Therefore, before strong inferences can be drawn concerning the rates and processes of speciation in arthropod systems, we must first assess whether extrinsic endosymbionts obscure patterns of speciation. Here, I use the Allonemobius fasciatus-socius species complex to determine what role Wolbachia has played in the presumed rapid divergence of this complex by analyzing patterns of mtDNA and nuclear DNA variation in conjunction with sequence and cytoplasmic incompatibility data on Wolbachia. Data on molecular variation suggest that Wolbachia has not induced a strong selective sweep of the mitochondrial genome; nor does Wolbachia appear to induce cytoplasmic incompatibility. Preliminary evidence indicates that a third species identified within this complex, A. sp. nov. Tex, is partially reproductively isolated from A. socius, its closest relative, via conspecific sperm precedence or some form of postzygotic isolation. Moreover, shared mitotypes between A. sp. nov. Tex and A. socius may indicate the occurrence of a hybrid zone between these species near the border of Texas and Louisiana, although they may also represent shared ancestral polymorphisms. Molecular data also indicate that all three species in this complex diverged from a common ancestor as recently as 3000-30,000 years ago. Finally, the radiation of this complex from its ancestral population likely occurred in the presence of one strain of Wolbachia, thus suggesting a minimal role for Wolbachia during this burst of speciation. In total, barriers to gene flow do appear to have evolved very rapidly in this group of crickets.}, }
@article {pmid15611174, year = {2004}, author = {Shoemaker, DD and Dyer, KA and Ahrens, M and McAbee, K and Jaenike, J}, title = {Decreased diversity but increased substitution rate in host mtDNA as a consequence of Wolbachia endosymbiont infection.}, journal = {Genetics}, volume = {168}, number = {4}, pages = {2049-2058}, pmid = {15611174}, issn = {0016-6731}, mesh = {Animals ; *DNA, Mitochondrial ; Drosophila/*genetics/*microbiology ; *Evolution, Molecular ; Genetic Variation ; Mitochondria/genetics ; Molecular Sequence Data ; Wolbachia/*metabolism ; }, abstract = {A substantial fraction of insects and other terrestrial arthropods are infected with parasitic, maternally transmitted endosymbiotic bacteria that manipulate host reproduction. In addition to imposing direct selection on the host to resist these effects, endosymbionts may also have indirect effects on the evolution of the mtDNA with which they are cotransmitted. Patterns of mtDNA diversity and evolution were examined in Drosophila recens, which is infected with the endosymbiont Wolbachia, and its uninfected sister species D. subquinaria. The level of mitochondrial, but not nuclear, DNA diversity is much lower in D. recens than in D. subquinaria, consistent with the hypothesized diversity-purging effects of an evolutionarily recent Wolbachia sweep. The d(N)/d(S) ratio in mtDNA is significantly greater in D. recens, suggesting that Muller's ratchet has brought about an increased rate of substitution of slightly deleterious mutations. The data also reveal elevated rates of synonymous substitutions in D. recens, suggesting that these sites may experience weak selection. These findings show that maternally transmitted endosymbionts can severely depress levels of mtDNA diversity within an infected host species, while accelerating the rate of divergence among mtDNA lineages in different species.}, }
@article {pmid15604675, year = {2004}, author = {Parisi, G and Perales, M and Fornasari, MS and Colaneri, A and González-Schain, N and Gómez-Casati, D and Zimmermann, S and Brennicke, A and Araya, A and Ferry, JG and Echave, J and Zabaleta, E}, title = {Gamma carbonic anhydrases in plant mitochondria.}, journal = {Plant molecular biology}, volume = {55}, number = {2}, pages = {193-207}, pmid = {15604675}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Arabidopsis/genetics ; Arabidopsis Proteins/genetics/metabolism ; Archaeal Proteins/chemistry/genetics/metabolism ; Binding Sites/genetics ; Carbonic Anhydrases/chemistry/*genetics/metabolism ; Green Fluorescent Proteins/genetics/metabolism ; Isoenzymes/chemistry/genetics/metabolism ; Methanosarcina/genetics ; Microscopy, Confocal ; Mitochondria/metabolism ; Mitochondrial Proteins/chemistry/*genetics/metabolism ; Models, Molecular ; Molecular Sequence Data ; *Phylogeny ; Plant Proteins/chemistry/*genetics/metabolism ; Plants, Genetically Modified ; Protein Conformation ; Protein Structure, Tertiary ; Protein Transport ; Recombinant Fusion Proteins/genetics/metabolism ; Sequence Homology, Amino Acid ; }, abstract = {Three genes from Arabidopsis thaliana with high sequence similarity to gamma carbonic anhydrase (gammaCA), a Zn containing enzyme from Methanosarcina thermophila (CAM), were identified and characterized. Evolutionary and structural analyses predict that these genes code for active forms of gammaCA. Phylogenetic analyses reveal that these Arabidopsis gene products cluster together with CAM and related sequences from alpha and gamma proteobacteria, organisms proposed as the mitochondrial endosymbiont ancestor. Indeed, in vitro and in vivo experiments indicate that these gene products are transported into the mitochondria as occurs with several mitochondrial protein genes transferred, during evolution, from the endosymbiotic bacteria to the host genome. Moreover, putative CAM orthologous genes are detected in other plants and green algae and were predicted to be imported to mitochondria. Structural modeling and sequence analysis performed in more than a hundred homologous sequences show a high conservation of functionally important active site residues. Thus, the three histidine residues involved in Zn coordination (His 81, 117 and 122), Arg 59, Asp 61, Gin 75, and Asp 76 of CAM are conserved and properly arranged in the active site cavity of the models. Two other functionally important residues (Glu 62 and Glu 84 of CAM) are lacking, but alternative amino acids that might serve to their roles are postulated. Accordingly, we propose that photosynthetic eukaryotic organisms (green algae and plants) contain gammaCAs and that these enzymes codified by nuclear genes are imported into mitochondria to accomplish their biological function.}, }
@article {pmid15599516, year = {2004}, author = {Wernegreen, JJ and Funk, DJ}, title = {Mutation exposed: a neutral explanation for extreme base composition of an endosymbiont genome.}, journal = {Journal of molecular evolution}, volume = {59}, number = {6}, pages = {849-858}, pmid = {15599516}, issn = {0022-2844}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aphids/microbiology ; Base Composition/genetics ; Base Sequence ; Buchnera/*genetics ; DNA Primers ; Databases, Nucleic Acid ; *Evolution, Molecular ; *Genetics, Population ; *Genome, Bacterial ; Molecular Sequence Data ; Mutation/*genetics ; *Selection, Genetic ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The influence of neutral mutation pressure versus selection on base composition evolution is a subject of considerable controversy. Yet the present study represents the first explicit population genetic analysis of this issue in prokaryotes, the group in which base composition variation is most dramatic. Here, we explore the impact of mutation and selection on the dynamics of synonymous changes in Buchnera aphidicola, the AT-rich bacterial endosymbiont of aphids. Specifically, we evaluated three forms of evidence. (i) We compared the frequencies of directional base changes (AT-->GC vs. GC-->AT) at synonymous sites within and between Buchnera species, to test for selective preference versus effective neutrality of these mutational categories. Reconstructed mutational changes across a robust intraspecific phylogeny showed a nearly 1:1 AT-->GC:GC-->AT ratio. Likewise, stationarity of base composition among Buchnera species indicated equal rates of AT-->GC and GC-->AT substitutions. The similarity of these patterns within and between species supported the neutral model. (ii) We observed an equivalence of relative per-site AT mutation rate and current AT content at synonymous sites, indicating that base composition is at mutational equilibrium. (iii) We demonstrated statistically greater equality in the frequency of mutational categories in Buchnera than in parallel mammalian studies that documented selection on synonymous sites. Our results indicate that effectively neutral mutational pressure, rather than selection, represents the major force driving base composition evolution in Buchnera. Thus they further corroborate recent evidence for the critical role of reduced N(e) in the molecular evolution of bacterial endosymbionts.}, }
@article {pmid15580780, year = {2005}, author = {Waller, RF and McFadden, GI}, title = {The apicoplast: a review of the derived plastid of apicomplexan parasites.}, journal = {Current issues in molecular biology}, volume = {7}, number = {1}, pages = {57-79}, pmid = {15580780}, issn = {1467-3037}, mesh = {Animals ; Antiprotozoal Agents/pharmacology ; Apicomplexa/drug effects/*physiology/ultrastructure ; Phylogeny ; Plastids/drug effects/*physiology/ultrastructure ; Protein Transport/physiology ; }, abstract = {The apicoplast is a plastid organelle, homologous to chloroplasts of plants, that is found in apicomplexan parasites such as the causative agents of Malaria Plasmodium spp. It occurs throughout the Apicomplexa and is an ancient feature of this group acquired by the process of endosymbiosis. Like plant chloroplasts, apicoplasts are semi-autonomous with their own genome and expression machinery. In addition, apicoplasts import numerous proteins encoded by nuclear genes. These nuclear genes largely derive from the endosymbiont through a process of intracellular gene relocation. The exact role of a plastid in parasites is uncertain but early clues indicate synthesis of lipids, heme and isoprenoids as possibilities. The various metabolic processes of the apicoplast are potentially excellent targets for drug therapy.}, }
@article {pmid15579697, year = {2004}, author = {Dyer, KA and Jaenike, J}, title = {Evolutionarily stable infection by a male-killing endosymbiont in Drosophila innubila: molecular evidence from the host and parasite genomes.}, journal = {Genetics}, volume = {168}, number = {3}, pages = {1443-1455}, pmid = {15579697}, issn = {0016-6731}, mesh = {Animals ; Drosophila/genetics/*microbiology ; Evolution, Molecular ; Female ; Genetic Variation ; Male ; Molecular Sequence Data ; Phylogeny ; Sex Ratio ; Wolbachia/genetics/*physiology ; }, abstract = {Maternally inherited microbes that spread via male-killing are common pathogens of insects, yet very little is known about the evolutionary duration of these associations. The few examples to date indicate very recent, and thus potentially transient, infections. A male-killing strain of Wolbachia has recently been discovered in natural populations of Drosophila innubila. The population-level effects of this infection are significant: approximately 35% of females are infected, infected females produce very strongly female-biased sex ratios, and the resulting population-level sex ratio is significantly female biased. Using data on infection prevalence and Wolbachia transmission rates, infected cytoplasmic lineages are estimated to experience a approximately 5% selective advantage relative to uninfected lineages. The evolutionary history of this infection was explored by surveying patterns of polymorphism in both the host and parasite genomes, comparing the Wolbachia wsp gene and the host mtDNA COI gene to five host nuclear genes. Molecular data suggest that this male-killing infection is evolutionarily old, a conclusion supported with a simple model of parasite and mtDNA transmission dynamics. Despite a large effective population size of the host species and strong selection to evolve resistance, the D. innubila-Wolbachia association is likely at a stable equilibrium that is maintained by imperfect maternal transmission of the bacteria rather than partial resistance in the host species.}, }
@article {pmid15577909, year = {2004}, author = {Hrdy, I and Hirt, RP and Dolezal, P and Bardonová, L and Foster, PG and Tachezy, J and Embley, TM}, title = {Trichomonas hydrogenosomes contain the NADH dehydrogenase module of mitochondrial complex I.}, journal = {Nature}, volume = {432}, number = {7017}, pages = {618-622}, doi = {10.1038/nature03149}, pmid = {15577909}, issn = {1476-4687}, mesh = {Aerobiosis ; Amino Acid Sequence ; Anaerobiosis ; Animals ; Electron Transport Complex I/chemistry/*metabolism ; Hydrogen/*metabolism ; Malates/metabolism ; Mitochondria/*enzymology/metabolism ; Models, Biological ; Molecular Sequence Data ; NAD/metabolism ; NADH Dehydrogenase/chemistry/*metabolism ; Organelles/*enzymology/metabolism ; Phylogeny ; Protein Subunits/chemistry/metabolism ; Protozoan Proteins/chemistry/metabolism ; Sequence Alignment ; Symbiosis ; Trichomonas vaginalis/*cytology/*enzymology/metabolism ; }, abstract = {Hydrogenosomes are double-membraned ATP-producing and hydrogen-producing organelles of diverse anaerobic eukaryotes. In some versions of endosymbiotic theory they are suggested to be homologues of mitochondria, but alternative views suggest they arose from an anaerobic bacterium that was distinct from the mitochondrial endosymbiont. Here we show that the 51-kDa and 24-kDa subunits of the NADH dehydrogenase module in complex I, the first step in the mitochondrial respiratory chain, are active in hydrogenosomes of Trichomonas vaginalis. Like mitochondrial NADH dehydrogenase, the purified Trichomonas enzyme can reduce a variety of electron carriers including ubiquinone, but unlike the mitochondrial enzyme it can also reduce ferredoxin, the electron carrier used for hydrogen production. The presence of NADH dehydrogenase solves the long-standing conundrum of how hydrogenosomes regenerate NAD+ after malate oxidation. Phylogenetic analyses show that the Trichomonas 51-kDa homologue shares common ancestry with the mitochondrial enzyme. Recruitment of complex I subunits into a H2-producing pathway provides evidence that mitochondria and hydrogenosomes are aerobic and anaerobic homologues of the same endosymbiotically derived organelle.}, }
@article {pmid15576054, year = {2004}, author = {Gabaldón, T and Huynen, MA}, title = {Shaping the mitochondrial proteome.}, journal = {Biochimica et biophysica acta}, volume = {1659}, number = {2-3}, pages = {212-220}, doi = {10.1016/j.bbabio.2004.07.011}, pmid = {15576054}, issn = {0006-3002}, mesh = {Animals ; *Biological Evolution ; Biological Transport ; Energy Metabolism ; Eukaryotic Cells/physiology ; Humans ; Mitochondria/*physiology ; Phylogeny ; Proteome/*physiology ; }, abstract = {Mitochondria are eukaryotic organelles that originated from a single bacterial endosymbiosis some 2 billion years ago. The transition from the ancestral endosymbiont to the modern mitochondrion has been accompanied by major changes in its protein content, the so-called proteome. These changes included complete loss of some bacterial pathways, amelioration of others and gain of completely new complexes of eukaryotic origin such as the ATP/ADP translocase and most of the mitochondrial protein import machinery. This renewal of proteins has been so extensive that only 14-16% of modern mitochondrial proteome has an origin that can be traced back to the bacterial endosymbiont. The rest consists of proteins of diverse origin that were eventually recruited to function in the organelle. This shaping of the proteome content reflects the transformation of mitochondria into a highly specialized organelle that, besides ATP production, comprises a variety of functions within the eukaryotic metabolism. Here we review recent advances in the fields of comparative genomics and proteomics that are throwing light on the origin and evolution of the mitochondrial proteome.}, }
@article {pmid15574807, year = {2005}, author = {Dale, C and Jones, T and Pontes, M}, title = {Degenerative evolution and functional diversification of type-III secretion systems in the insect endosymbiont Sodalis glossinidius.}, journal = {Molecular biology and evolution}, volume = {22}, number = {3}, pages = {758-766}, doi = {10.1093/molbev/msi061}, pmid = {15574807}, issn = {0737-4038}, mesh = {Animals ; Bacterial Proteins/*genetics/*metabolism ; Cell Line ; *Evolution, Molecular ; Gram-Negative Bacteria/*genetics/*physiology ; Insecta/physiology ; Symbiosis/genetics/physiology ; }, abstract = {Sodalis glossinidius, a maternally transmitted endosymbiont of tsetse flies, maintains two phylogenetically distinct type-III secretion systems encoded by chromosomal symbiosis regions designated SSR-1 and SSR-2. Although both symbiosis regions are closely related to extant pathogenicity islands with similar gene inventories, SSR-2 has undergone novel degenerative adaptations in the transition to mutualism. Notably, SSR-2 lacks homologs of genes found in SSR-1 that encode secreted effector proteins known to facilitate the host cell cytoskeletal rearrangements necessary for bacterial entry and uptake into eukaryotic cells. Also, as a result of relaxed selection, SSR-2 has undergone inactivation of genes encoding components of the type-III secretion system needle substructure. In the current study, we used quantitative PCR to determine the expression profiles of ysaV (SSR-1) and invA (SSR-2) transcripts when S. glossinidius infects an insect cell line, and we used an invasion assay to characterize the phenotype of an S. glossinidius mutant that lacks the ability to produce an OrgA protein that is required for function of the SSR-2 secretome. Whereas SSR-1 is required for bacterial invasion of host cells and ysaV is expressed when bacteria contact host cells, SSR-2 is required for bacterial proliferation after entry, and invA is only expressed in the intracellular stage of infection. These results demonstrate that degenerative genetic adaptations in SSR-2 have promoted functional diversification of the Sodalis SSR-2 type-III secretion system.}, }
@article {pmid15562592, year = {2004}, author = {Dittmar, K and Whiting, MF}, title = {New Wolbachia endosymbionts from Nearctic and Neotropical fleas (Siphonaptera).}, journal = {The Journal of parasitology}, volume = {90}, number = {5}, pages = {953-957}, doi = {10.1645/GE-186R}, pmid = {15562592}, issn = {0022-3395}, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; Consensus Sequence ; DNA, Bacterial/chemistry ; DNA, Ribosomal/*chemistry ; Female ; Male ; Molecular Sequence Data ; North America ; Phylogeny ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/*genetics ; Siphonaptera/*microbiology ; South America ; Symbiosis ; Wolbachia/*classification/genetics/isolation &amp; purification ; }, abstract = {Several species of fleas (Siphonaptera), ectoparasites of mammals and birds, have recently been shown to harbor species of Wolbachia. Here, we extend this data set to 20 more species of Siphonaptera (Rhopalopsyllidae, Stephanocircidae, Pulicidae, Ceratophyllidae, Ctenophthalmidae, Ischnopsyllidae, Leptopsyllidae, and Malacopsyllidae) from sylvatic populations throughout the Nearctic and Neotropical regions. Using polymerase chain reaction, we targeted the Wolbachia 16S ribosomal DNA (rDNA) gene. Applying maximum parsimony- and maximum likelihood-based algorithms, as well as statistical parsimony, we conducted a phylogenetic analysis of Wolbachia 16S rDNA to evaluate its position within the known Wolbachia spp. The analysis recovered the siphonapteran Wolbachia 16S rDNA sequences as a monophyletic group and shows multiple haplotype connections between the Neotropical and Nearctic Wolbachia strains of fleas.}, }
@article {pmid15562287, year = {2005}, author = {Mouton, L and Henri, H and Boulétreau, M and Vavre, F}, title = {Multiple infections and diversity of cytoplasmic incompatibility in a haplodiploid species.}, journal = {Heredity}, volume = {94}, number = {2}, pages = {187-192}, doi = {10.1038/sj.hdy.6800596}, pmid = {15562287}, issn = {0018-067X}, mesh = {Animals ; Diploidy ; Female ; France ; Haploidy ; Male ; Reproduction/physiology ; Species Specificity ; Wasps/*microbiology/*physiology ; *Wolbachia ; }, abstract = {Cytoplasmic incompatibility (CI) is a sperm-egg incompatibility commonly induced by the intracellular endosymbiont bacterium Wolbachia that, in diploid species, results in embryo mortality. In haplodiploid species, two types of CI exist depending on whether the incompatible fertilized eggs develop into males (male development (MD)) or abort (female mortality (FM)). CI allows multiple infections to be maintained in host populations, and thus allows interactions to occur between co-infecting strains. In Leptopilina heterotoma, three Wolbachia strains coexist naturally (wLhet1, wLhet2, wLhet3). When these three strains are all present, they induce a CI of FM type, whereas wLhet1 alone expresses a CI phenotype intermediate between MD and FM. Here, we compare CI effects in crosses involving insect lines sharing the same nuclear background, but harboring different mixtures of strains. Mating experiments showed that: (i) wLhet2 and wLhet3 also induce an intermediate CI when acting alone, and show a bidirectional incompatibility; (ii) there is no interaction between the co-infecting strains in CI expression; (iii) the diversity of Wolbachia present within a male host influences the expression of CI: an increase in the number of strains is correlated with a decrease in the proportion of the MD type, which is also correlated with an increase in bacterial density. All these data suggest that the CI of FM type results from a stronger effect than the MD type, which conflicts with the conventional hypotheses used to explain CI diversity in haplodiploids, and could provide some new information about CI mechanisms in insects.}, }
@article {pmid15560823, year = {2004}, author = {Park, M and Yun, ST and Kim, MS and Chun, J and Ahn, TI}, title = {Phylogenetic characterization of Legionella-like endosymbiotic X-bacteria in Amoeba proteus: a proposal for 'Candidatus Legionella jeonii' sp. nov.}, journal = {Environmental microbiology}, volume = {6}, number = {12}, pages = {1252-1263}, doi = {10.1111/j.1462-2920.2004.00659.x}, pmid = {15560823}, issn = {1462-2912}, mesh = {Amino Acid Sequence ; Amoeba/*microbiology ; Animals ; Bacterial Proteins/genetics ; DNA, Bacterial/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry/genetics/isolation &amp; purification ; DNA-Directed RNA Polymerases/genetics ; Genes, rRNA ; Immunophilins/genetics ; In Situ Hybridization, Fluorescence ; Legionella/*classification/genetics/*isolation &amp; purification ; Membrane Proteins/genetics ; Molecular Sequence Data ; Peptidylprolyl Isomerase/genetics ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {The X-bacteria which initiated organismic association with the D strain of Amoeba proteus in 1966 as parasites have changed to obligate endosymbionts on which the host depends for survival. Owing to the difficulty in cultivating the bacteria in vitro, the identity of X-bacteria has not been determined. As the life cycle of X-bacteria is similar to that of Legionella spp. in soil amoebae, we applied the polymerase chain reaction method with specific primers aimed at Legionella spp. for the detection and cloning of 16S rRNA gene. The identity and intracellular localization of the endosymbiont were confirmed by the application of a specific fluorescently labelled 16S rRNA-targeted probe. In addition we cloned RNA polymerase beta-subunit gene (rpoB) of X-bacteria by genomic library tagging. A phylogenetic analysis of the 16S rRNA gene placed the bacterium within a unique monophyletic group containing all other members of the genus Legionella. Phylogeny from rpoB and mip genes further confirmed the taxonomic context of X-bacteria to be a Legionella sp. In all three phylogenic analyses, X-bacterium was placed apart from Legionella-like amoebal pathogens present in soil amoebae. Thus, we propose the name 'Candidatus Legionella jeonii' sp. nov. for the endosymbiotic X-bacteria in Amoeba proteus.}, }
@article {pmid15556475, year = {2004}, author = {Pérez-Rueda, E and Collado-Vides, J and Segovia, L}, title = {Phylogenetic distribution of DNA-binding transcription factors in bacteria and archaea.}, journal = {Computational biology and chemistry}, volume = {28}, number = {5-6}, pages = {341-350}, doi = {10.1016/j.compbiolchem.2004.09.004}, pmid = {15556475}, issn = {1476-9271}, mesh = {Amino Acid Sequence ; Archaea/*genetics/metabolism ; Bacteria/*genetics/metabolism ; DNA/chemistry/*genetics/metabolism ; Molecular Sequence Data ; Phylogeny ; Sequence Homology, Amino Acid ; Transcription Factors, General/genetics/*metabolism ; }, abstract = {We have addressed the distribution and abundance of 75 transcription factor (TF) families in complete genomes from 90 different bacterial and archaeal species. We found that the proportion of TFs increases with genome size. The deficit of TFs in some genomes might be compensated by the presence of proteins organizing and compacting DNA, such as histone-like proteins. Nine families are represented in all the bacteria and archaea we analyzed, whereas 17 families are specific to bacteria, providing evidence for regulon specialization at an early stage of evolution between the bacterial and archeal lineages. Ten of the 17 families identified in bacteria belong exclusively to the proteobacteria defining a specific signature for this taxonomical group. In bacteria, 10 families are lost mostly in intracellular pathogens and endosymbionts, while 9 families seem to have been horizontally transferred to archaea. The winged helix-turn-helix (HTH) is by far the most abundant structure (motif) in prokaryotes, and might have been the earliest HTH motif to appear as shown by its distribution and abundance in both bacterial and archaeal cellular domains. Horizontal gene transfer and lineage-specific gene losses suggest a progressive elimination of TFs in the course of archaeal and bacterial evolution. This analysis provides a framework for discussing the selective forces directing the evolution of the transcriptional machinery in prokaryotes.}, }
@article {pmid15545464, year = {2004}, author = {Van Oevelen, S and De Wachter, R and Vandamme, P and Robbrecht, E and Prinsen, E}, title = {'Candidatus Burkholderia calva' and 'Candidatus Burkholderia nigropunctata' as leaf gall endosymbionts of African Psychotria.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {54}, number = {Pt 6}, pages = {2237-2239}, doi = {10.1099/ijs.0.63188-0}, pmid = {15545464}, issn = {1466-5026}, mesh = {Burkholderia/*classification/*isolation &amp; purification/physiology/ultrastructure ; DNA, Bacterial/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry/isolation &amp; purification ; Genes, rRNA ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; Phylogeny ; Plant Leaves/microbiology ; Psychotria/*microbiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Phylogenetic 16S rRNA gene analysis was used to assign the bacterial leaf-nodulating endosymbionts of two tropical African Psychotria species to the genus Burkholderia. The microsymbionts of the different Psychotria hosts were recognized as distinct and novel species of Burkholderia on the basis of relatively low intersequence similarities and sufficiently large evolutionary distances when compared with each other and their closest validly named neighbours. The obligate endosymbiotic nature of the bacteria prevented their in vitro cultivation and the deposition of type strains to culture collections. Therefore, the provisional status Candidatus is assigned to the bacterial partners of Psychotria calva and Psychotria nigropunctata, with the proposal of the names 'Candidatus Burkholderia calva' and 'Candidatus Burkholderia nigropunctata', respectively.}, }
@article {pmid15537084, year = {2004}, author = {Horn, M and Wagner, M}, title = {Bacterial endosymbionts of free-living amoebae.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {5}, pages = {509-514}, doi = {10.1111/j.1550-7408.2004.tb00278.x}, pmid = {15537084}, issn = {1066-5234}, mesh = {Amoeba/genetics/*microbiology ; Animals ; Chlamydia/genetics/metabolism/physiology ; Phylogeny ; RNA, Bacterial/analysis ; Rickettsieae/genetics/metabolism/physiology ; Symbiosis/*physiology ; }, abstract = {The occurrence of bacterial endosymbionts in free-living amoebae has been known for decades, but their obligate intracellular lifestyle hampered their identification. Application of the full cycle rRNA approach, including 16S rRNA gene sequencing and fluorescence in-situ hybridization with 16S rRNA-targeted oligonucleotide probes, assigned the symbionts of Acanthamoeba spp. and Hartmannella sp. to five different evolutionary lineages within the Proteobacteria, the Bacteroidetes, and the Chlamydiae, respectively. Some of these bacterial symbionts are most closely related to bacterial pathogens of humans, and it has been suggested that they should be considered potential emerging pathogens. Complete genome sequence analysis of a chlamydia-related symbiont of Acanthamoeba sp. showed that this endosymbiont uses similar mechanisms for interaction with its eukaryotic host cell as do the well-known bacterial pathogens of humans. Furthermore, phylogenetic analysis suggested that these mechanisms have been evolved by the ancestor of these amoeba symbionts in interplay with ancient unicellular eukaryotes.}, }
@article {pmid15537083, year = {2004}, author = {Jeon, KW}, title = {Genetic and physiological interactions in the amoeba-bacteria symbiosis.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {5}, pages = {502-508}, doi = {10.1111/j.1550-7408.2004.tb00277.x}, pmid = {15537083}, issn = {1066-5234}, mesh = {Amoeba/genetics/*microbiology/physiology ; Animals ; Bacteria/*genetics ; *Bacterial Physiological Phenomena ; Gene Expression Regulation, Enzymologic ; *Symbiosis ; }, abstract = {Amoebae of the xD strain of Amoeba proteus that arose from the D strain by spontaneous infection of Legionella-like X-bacteria are now dependent on their symbionts for survival. Each xD amoeba contains about 42,000 symbionts within symbiosomes, and established xD amoebae die if their symbionts are removed. Thus, harmful infective bacteria changed into necessary cell components. As a result of harboring X-bacteria. xD amoebae exhibit various physiological and genetic characteristics that are different from those of symbiont-free D amoebae. One of the recent findings is that bacterial symbionts control the expression of a host's house-keeping gene. Thus, the expression of the normal amoeba sams gene (sams1) encoding one form of S-adenosylmethionine synthetase is switched to that of sams2 by endosymbiotic X-bacteria. Possible mechanisms for the switching of sams genes brought about by endosymbionts and its significance are discussed.}, }
@article {pmid15537082, year = {2004}, author = {Marciano-Cabral, F}, title = {Introductory remarks: bacterial endosymbionts or pathogens of free-living amebae1.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {5}, pages = {497-501}, doi = {10.1111/j.1550-7408.2004.tb00276.x}, pmid = {15537082}, issn = {1066-5234}, support = {P50DA05274/DA/NIDA NIH HHS/United States ; }, mesh = {Amoeba/*microbiology/ultrastructure ; Animals ; Bacteria/*metabolism/pathogenicity ; Humans ; Symbiosis/*physiology ; }, abstract = {Free-living amebae are ubiquitous in the environment and can be isolated from a variety of habitats including water, soil, air, hospital water systems, dental units, contact lens cases, and cooling towers. The interaction of amebae with other microorganisms in their environment is varied. Bacteria are a major food source for free-living amebae. However, some bacteria have established a stable symbiotic relationship with amebae. Recent reports indicate an association of amebae with intracellular bacterial pathogens. Such amebae may serve as reservoirs for maintaining and dispersing pathogenic bacteria in the environment or as vectors of bacterial disease in humans.}, }
@article {pmid15535864, year = {2004}, author = {Huang, J and Mullapudi, N and Lancto, CA and Scott, M and Abrahamsen, MS and Kissinger, JC}, title = {Phylogenomic evidence supports past endosymbiosis, intracellular and horizontal gene transfer in Cryptosporidium parvum.}, journal = {Genome biology}, volume = {5}, number = {11}, pages = {R88}, pmid = {15535864}, issn = {1474-760X}, support = {R01 AI045806/AI/NIAID NIH HHS/United States ; 1R01AI045806-01A1/AI/NIAID NIH HHS/United States ; AI05093/AI/NIAID NIH HHS/United States ; U01 AI 46397/AI/NIAID NIH HHS/United States ; }, mesh = {1,4-alpha-Glucan Branching Enzyme/genetics ; Animals ; Cryptosporidium parvum/*genetics ; Eukaryota/genetics ; Evolution, Molecular ; Gene Expression Profiling/methods ; Gene Expression Regulation/genetics ; Gene Transfer, Horizontal/*genetics ; Genes/genetics ; Genes, Bacterial/genetics ; *Genome, Protozoan ; *Phylogeny ; Symbiosis/*genetics ; }, abstract = {BACKGROUND: The apicomplexan parasite Cryptosporidium parvum is an emerging pathogen capable of causing illness in humans and other animals and death in immunocompromised individuals. No effective treatment is available and the genome sequence has recently been completed. This parasite differs from other apicomplexans in its lack of a plastid organelle, the apicoplast. Gene transfer, either intracellular from an endosymbiont/donor organelle or horizontal from another organism, can provide evidence of a previous endosymbiotic relationship and/or alter the genetic repertoire of the host organism. Given the importance of gene transfers in eukaryotic evolution and the potential implications for chemotherapy, it is important to identify the complement of transferred genes in Cryptosporidium.<br><br>RESULTS: We have identified 31 genes of likely plastid/endosymbiont (n = 7) or prokaryotic (n = 24) origin using a phylogenomic approach. The findings support the hypothesis that Cryptosporidium evolved from a plastid-containing lineage and subsequently lost its apicoplast during evolution. Expression analyses of candidate genes of algal and eubacterial origin show that these genes are expressed and developmentally regulated during the life cycle of C. parvum.<br><br>CONCLUSIONS: Cryptosporidium is the recipient of a large number of transferred genes, many of which are not shared by other apicomplexan parasites. Genes transferred from distant phylogenetic sources, such as eubacteria, may be potential targets for therapeutic drugs owing to their phylogenetic distance or the lack of homologs in the host. The successful integration and expression of the transferred genes in this genome has changed the genetic and metabolic repertoire of the parasite.}, }
@article {pmid15528727, year = {2004}, author = {Draghi, A and Popov, VL and Kahl, MM and Stanton, JB and Brown, CC and Tsongalis, GJ and West, AB and Frasca, S}, title = {Characterization of "Candidatus piscichlamydia salmonis" (order Chlamydiales), a chlamydia-like bacterium associated with epitheliocystis in farmed Atlantic salmon (Salmo salar).}, journal = {Journal of clinical microbiology}, volume = {42}, number = {11}, pages = {5286-5297}, pmid = {15528727}, issn = {0095-1137}, mesh = {Animals ; Chlamydia Infections/microbiology/pathology/*veterinary ; Chlamydiales/*classification/*genetics/isolation &amp; purification ; DNA, Ribosomal/analysis ; Fish Diseases/*microbiology/pathology ; Gills/microbiology/pathology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Salmo salar/*microbiology ; Sequence Analysis, DNA ; }, abstract = {To characterize intracellular gram-negative bacteria associated with epitheliocystis in farmed Atlantic salmon (Salmo salar), gills with proliferative lesions were collected for histopathology, conventional transmission and immunoelectron microscopy, in situ hybridization, and DNA extraction during epitheliocystis outbreaks in Ireland and Norway in 1999 and 2000, respectively, and compared by ultrastructure and immunoreactivity to nonproliferative gills from Ireland archived in 1995. Genomic DNA from proliferative gills was used to amplify 16S ribosomal DNA (rDNA) for molecular phylogenetic analyses. Epitheliocystis inclusions from proliferative gills possessed variably elongate reticulate bodies, examples of binary fission, and vacuolated and nonvacuolated intermediate bodies, whereas inclusions in nonproliferative gills had typical chlamydial developmental stages plus distinctive head-and-tail cells. Immunogold processing using anti-chlamydial lipopolysaccharide antibody labeled reticulate bodies from proliferative and nonproliferative gills. 16S rDNA amplified directly from Irish (1999) and Norwegian (2000) gill samples demonstrated 99% nucleotide identity, and riboprobes transcribed from cloned near-full-length 16S rDNA amplicons from Norwegian gills hybridized with inclusions in proliferative lesions from Irish (1999) and Norwegian (2000) sections. A 1,487-bp consensus 16S rRNA gene sequence representing the chlamydia-like bacterium (CLB) from proliferative gills had the highest percent nucleotide identity with endosymbionts of Acanthamoeba spp. (order Chlamydiales). Molecular phylogenetic relationships inferred from 16S rRNA gene sequences using distance and parsimony indicated that the CLB from proliferative gills branched with members of the order Chlamydiales. "Candidatus Piscichlamydia salmonis" is proposed for the CLB associated with epitheliocystis from proliferative gills of Atlantic salmon, which exhibits developmental stages different from those identified in nonproliferative gills.}, }
@article {pmid15528527, year = {2004}, author = {Baldridge, GD and Burkhardt, NY and Simser, JA and Kurtti, TJ and Munderloh, UG}, title = {Sequence and expression analysis of the ompA gene of Rickettsia peacockii, an endosymbiont of the Rocky Mountain wood tick, Dermacentor andersoni.}, journal = {Applied and environmental microbiology}, volume = {70}, number = {11}, pages = {6628-6636}, pmid = {15528527}, issn = {0099-2240}, support = {R01 AI049424/AI/NIAID NIH HHS/United States ; R01 AI49424/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/*genetics/*metabolism ; Colorado ; DNA, Bacterial/analysis ; Dermacentor/*microbiology ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Rickettsia/*genetics/growth &amp; development ; Rickettsia rickettsii/genetics ; *Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The transmission dynamics of Rocky Mountain spotted fever in Montana appears to be regulated by Rickettsia peacockii, a tick symbiotic rickettsia that interferes with transmission of virulent Rickettsia rickettsii. To elucidate the molecular relationships between the two rickettsiae and glean information on how to possibly exploit this interference phenomenon, we studied a major rickettsial outer membrane protein gene, ompA, presumed to be involved in infection and pathogenesis of spotted fever group rickettsiae (SFGR) but which is not expressed in the symbiont. Based on PCR amplification and DNA sequence analysis of the SFGR ompA gene, we demonstrate that R. peacockii is the most closely related of all known SFGR to R. rickettsii. We show that R. peacockii, originally described as East Side agent in Dermacentor andersoni ticks from the east side of the Bitterroot Valley in Montana, is still present in that tick population as well as in D. andersoni ticks collected at two widely separated locations in Colorado. The ompA genes of R. peacockii from these locations share three identical premature stop codons and a weakened ribosome binding site consensus sequence relative to ompA of R. rickettsii. The R. peacockii ompA promoter closely resembles that of R. rickettsii and is functional based on reverse transcription-PCR results. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting showed that OmpA translation products were not detected in cultured tick cells infected with R. peacockii. Double immunolabeling studies revealed actin tail structures in tick cells infected with R. rickettsii strain Hlp#2 but not in cells infected with R. peacockii.}, }
@article {pmid15525700, year = {2005}, author = {Herbeck, JT and Degnan, PH and Wernegreen, JJ}, title = {Nonhomogeneous model of sequence evolution indicates independent origins of primary endosymbionts within the enterobacteriales (gamma-Proteobacteria).}, journal = {Molecular biology and evolution}, volume = {22}, number = {3}, pages = {520-532}, doi = {10.1093/molbev/msi036}, pmid = {15525700}, issn = {0737-4038}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Base Sequence/genetics ; Chaperonin 60/*genetics ; Enterobacteriaceae/*genetics ; *Evolution, Molecular ; Genes, Bacterial/*genetics ; *Models, Genetic ; Plants/microbiology ; RNA, Ribosomal, 16S/*genetics ; Symbiosis/genetics ; }, abstract = {Standard methods of phylogenetic reconstruction are based on models that assume homogeneity of nucleotide composition among taxa. However, this assumption is often violated in biological data sets. In this study, we examine possible effects of nucleotide heterogeneity among lineages on the phylogenetic reconstruction of a bacterial group that spans a wide range of genomic nucleotide contents: obligately endosymbiotic bacteria and free-living or commensal species in the gamma-Proteobacteria. We focus on AT-rich primary endosymbionts to better understand the origins of obligately intracellular lifestyles. Previous phylogenetic analyses of this bacterial group point to the importance of accounting for base compositional variation in estimating relationships, particularly between endosymbiotic and free-living taxa. Here, we develop an approach to compare susceptibility of various phylogenetic reconstruction methods to the effects of nucleotide heterogeneity. First, we identify candidate trees of gamma-Proteobacteria groEL and 16S rRNA using approaches that assume homogeneous and stationary base composition, including Bayesian, maximum likelihood, parsimony, and distance methods. We then create permutations of the resulting candidate trees by varying the placement of the AT-rich endosymbiont Buchnera. These permutations are evaluated under the nonhomogeneous and nonstationary maximum likelihood model of Galtier and Gouy, which allows equilibrium base content to vary among examined lineages. Our results show that commonly used phylogenetic methods produce incongruent trees of the Enterobacteriales, and that the placement of Buchnera is especially unstable. However, under a nonhomogeneous model, various groEL and 16S rRNA phylogenies that separate Buchnera from other AT-rich endosymbionts (Blochmannia and Wigglesworthia) have consistently and significantly higher likelihood scores. Blochmannia and Wigglesworthia appear to have evolved from secondary endosymbionts, and represent an origin of primary endosymbiosis that is independent from Buchnera. This application of a nonhomogeneous model offers a computationally feasible way to test specific phylogenetic hypotheses for taxa with heterogeneous and nonstationary base composition.}, }
@article {pmid15522730, year = {2004}, author = {Belda, E and Sentandreu, V and Silva, FJ}, title = {Identification and separation of PCR products based on their GC content by denaturing high-performance liquid chromatography.}, journal = {Journal of chromatography. B, Analytical technologies in the biomedical and life sciences}, volume = {811}, number = {2}, pages = {263-268}, doi = {10.1016/j.jchromb.2004.09.010}, pmid = {15522730}, issn = {1570-0232}, mesh = {Chromatography, High Pressure Liquid/*methods ; Cytidine/*analysis ; DNA/*chemistry ; Guanosine/*analysis ; *Nucleic Acid Denaturation ; Polymerase Chain Reaction/*methods ; }, abstract = {We show that denaturing high-performance liquid chromatography is a suitable method for the separation of DNA molecules of similar sizes but with different GC contents. A mixture of homologous molecules coming from different bacterial species may be obtained when PCR with degenerate primers is used for the amplification of a specific gene from an environmental sample. We have observed that, by selecting an appropriate temperature for the partial denaturation of the molecules, we are able to separate them according to the GC content of each DNA product. This allows us to determine if one or several types of molecules are amplified in the course of a PCR reaction. In the latter case it is possible, even with minority products, to isolate them by collecting the eluted volumes, followed by cloning, sequencing or reamplifying them by PCR, depending on the DNA concentration. We have applied this analysis to the amplification of a fragment of the ribA gene in the bacterial endosymbionts of insects, obtaining a high correlation coefficient (0.978) between retention time and the GC content of the molecules.}, }
@article {pmid15510149, year = {2004}, author = {Dyall, SD and Yan, W and Delgadillo-Correa, MG and Lunceford, A and Loo, JA and Clarke, CF and Johnson, PJ}, title = {Non-mitochondrial complex I proteins in a hydrogenosomal oxidoreductase complex.}, journal = {Nature}, volume = {431}, number = {7012}, pages = {1103-1107}, doi = {10.1038/nature02990}, pmid = {15510149}, issn = {1476-4687}, mesh = {Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Animals ; Biological Evolution ; Carbohydrate Metabolism ; Electron Transport Complex I/chemistry/*metabolism ; Fermentation ; Hydrogen/*metabolism ; Hydrogenase/metabolism ; Iron-Sulfur Proteins/metabolism ; Ketone Oxidoreductases/metabolism ; Mitochondrial Proteins/chemistry ; Models, Biological ; Molecular Sequence Data ; NADH Dehydrogenase/chemistry/*metabolism ; Organelles/*enzymology/metabolism ; Oxidation-Reduction ; Phosphorylation ; Phylogeny ; Protein Binding ; Pyruvate Synthase ; Pyruvic Acid/metabolism ; Symbiosis ; Trichomonas vaginalis/*cytology/*enzymology/metabolism ; }, abstract = {Trichomonas vaginalis is a unicellular microaerophilic eukaryote that lacks mitochondria yet contains an alternative organelle, the hydrogenosome, involved in pyruvate metabolism. Pathways between the two organelles differ substantially: in hydrogenosomes, pyruvate oxidation is catalysed by pyruvate:ferredoxin oxidoreductase (PFOR), with electrons donated to an [Fe]-hydrogenase which produces hydrogen. ATP is generated exclusively by substrate-level phosphorylation in hydrogenosomes, as opposed to oxidative phosphorylation in mitochondria. PFOR and hydrogenase are found in eubacteria and amitochondriate eukaryotes, but not in typical mitochondria. Analyses of mitochondrial genomes indicate that mitochondria have a single endosymbiotic origin from an alpha-proteobacterial-type progenitor. The absence of a genome in trichomonad hydrogenosomes precludes such comparisons, leaving the endosymbiotic history of this organelle unclear. Although phylogenetic reconstructions of a few proteins indicate that trichomonad hydrogenosomes share a common origin with mitochondria, others do not. Here we describe a novel NADH dehydrogenase module of respiratory complex I that is coupled to the central hydrogenosomal fermentative pathway to form a hydrogenosomal oxidoreductase complex that seems to function independently of quinones. Phylogenetic analyses of hydrogenosomal complex I-like proteins Ndh51 and Ndh24 reveal that neither has a common origin with mitochondrial homologues. These studies argue against a vertical origin of trichomonad hydrogenosomes from the proto-mitochondrial endosymbiont.}, }
@article {pmid15501467, year = {2004}, author = {Engelstädter, J and Telschow, A and Hammerstein, P}, title = {Infection dynamics of different Wolbachia-types within one host population.}, journal = {Journal of theoretical biology}, volume = {231}, number = {3}, pages = {345-355}, doi = {10.1016/j.jtbi.2004.06.029}, pmid = {15501467}, issn = {0022-5193}, mesh = {Animals ; Cytoplasm/parasitology ; Death ; Female ; Host-Parasite Interactions ; Male ; Models, Biological ; Parthenogenesis ; Rickettsiaceae Infections/*parasitology ; Symbiosis ; *Wolbachia ; }, abstract = {Wolbachia are widespread intracellular symbionts of arthropods which are known to cause several reproductive manipulations in their hosts, the commonest of which being cytoplasmic incompatibility (CI), male killing (MK), and the induction of parthenogenesis (PI). Strains of endosymbionts inducing one of these effects can be referred to as 'Wolbachia-types'. Here, we try to ascertain whether two of these Wolbachia-types can stably coexist within one population. We investigate this question by means of two discrete-time mathematical models which describe the dynamics of an infection of a host population with either CI- and MK- or CI- and PI-Wolbachia. We derive analytical solutions for two special cases of each model showing that stable coexistence of the respective Wolbachia-types is not possible if no doubly infected individuals occur within the population and that stable coexistence is possible when doubly infected hosts do exist and transmission of the endosymbionts is perfect. Moreover, we show that a population infected with either CI- or MK-Wolbachia at equilibrium can resist invasion of the respective other Wolbachia-type as a single infection. In contrast, a population infected with CI-Wolbachia can be invaded by PI-Wolbachia as a single infection with the CI-Wolbachia going extinct. Computer simulations confirmed these findings for the general models. We discuss our results with respect to the prevalence of the Wolbachia-types considered here and the emergence of PI- from CI-Wolbachia.}, }
@article {pmid15491598, year = {2004}, author = {Harcombe, W and Hoffmann, AA}, title = {Wolbachia effects in Drosophila melanogaster: in search of fitness benefits.}, journal = {Journal of invertebrate pathology}, volume = {87}, number = {1}, pages = {45-50}, doi = {10.1016/j.jip.2004.07.003}, pmid = {15491598}, issn = {0022-2011}, mesh = {Animals ; Drosophila melanogaster/*microbiology/*physiology ; Heat Stress Disorders ; Host-Parasite Interactions ; Nutritional Physiological Phenomena ; Rickettsiaceae Infections/*physiopathology ; Symbiosis/*physiology ; Wolbachia/*physiology ; }, abstract = {Insect endosymbionts often influence host nutrition but these effects have not been comprehensively investigated in Wolbachia endosymbionts that are widespread in insects. Using strains of Drosophila melanogaster with the wMel Wolbachia infection, we showed that Wolbachia did not influence adult starvation resistance. Wolbachia also had no effect on larval development time or the size of emerging adults from a low nutrition medium. While Wolbachia may influence the expression of heat shock proteins, we found that there was no effect on adult heat resistance when tested in terms of survival or virility following heat stress. The absence of nutrition or stress effects suggests that other processes maintain wMel frequencies in natural populations of Drosophila melanogaster.}, }
@article {pmid15491544, year = {2004}, author = {Luchetti, A and Mantovani, B and Fioravanti, ML and Trentini, M}, title = {Wolbachia infection in the newly described Ecuadorian sand flea, Tunga trimamillata.}, journal = {Experimental parasitology}, volume = {108}, number = {1-2}, pages = {18-23}, doi = {10.1016/j.exppara.2004.07.003}, pmid = {15491544}, issn = {0014-4894}, mesh = {Animals ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/*analysis ; DNA, Ribosomal/*analysis ; Female ; Genotype ; Host-Parasite Interactions ; Male ; Molecular Sequence Data ; Phenotype ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; Reproduction ; Sequence Alignment ; Sex Ratio ; Siphonaptera/genetics/*microbiology/physiology ; Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification/physiology ; }, abstract = {Wolbachia pipientis is an intracellular endosymbiont producing reproductive alterations in its hosts. This bacterium have been reported in many arthropods and nematodes. By PCR amplification and sequencing of the 16S rDNA and ftsZ genes we have identified a Wolbachia strain in the newly described sand-flea, Tunga trimamillata. Prevalence of this endosymbiont in the 26 individuals screened is equal to 35%. Sympatric and allopatric specimens of the related species Tunga penetrans were also analysed, but in contrast to literature data, Wolbachia appears absent in the presently analysed 24 specimens. Field studies evidence a female-biased sex-ratio in T. trimamillata, suggesting that Wolbachia may cause sex-ratio distortion in this species. By means of BLAST search and phylogenetic analysis we found that the Wolbachia strain from T. trimamillata pertains to the arthropod-infecting Wolbachia; this strain is highly differentiated from the Wolbachia strain of T. penetrans described in literature.}, }
@article {pmid15482887, year = {2004}, author = {Morchón, R and Ferreira, AC and Martín-Pacho, JR and Montoya, A and Mortarino, M and Genchi, C and Simón, F}, title = {Specific IgG antibody response against antigens of Dirofilaria immitis and its Wolbachia endosymbiont bacterium in cats with natural and experimental infections.}, journal = {Veterinary parasitology}, volume = {125}, number = {3-4}, pages = {313-321}, doi = {10.1016/j.vetpar.2004.08.003}, pmid = {15482887}, issn = {0304-4017}, mesh = {Animals ; Anthelmintics/therapeutic use ; Antibodies, Bacterial/blood ; Antibodies, Helminth/blood ; Antibody Specificity ; Antigens, Helminth/*immunology ; Cat Diseases/drug therapy/immunology/microbiology/*parasitology ; Cats ; Dirofilaria immitis/*immunology/metabolism ; Dirofilariasis/drug therapy/*immunology/parasitology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Female ; Heart/parasitology ; Immunoglobulin G/*biosynthesis/blood/immunology ; Ivermectin/therapeutic use ; Male ; Peptide Fragments/immunology ; Pulmonary Artery/parasitology ; Wolbachia/*immunology/metabolism ; }, abstract = {Sera from three groups of cats under different experimental conditions were studied by ELISA to assess the host's immune response against synthetic peptides derived from Dirofilaria immitis (Dipp) and against the surface protein of its endosymbiont, Wolbachia (WSPr). In experimentally infected cats (Group 1), an increase of IgG antibody against both Dipp and WSPr was observed from 2 months post-infection until the end of the study, 6 months post-infection. In experimentally infected cats, treated against infective larvae (Group 2), anti-Dipp IgG decreased dramatically from 4 months post-infection (3 months post treatment), showing very low values till the end of the study (6.5 months from infection, 5.5 months from treatment), while anti-WSP IgG increased constantly till the end of the study. Of 49 outdoor, asymptomatic cats exposed to a high risk of natural infection (Group 3), 9 were positive for anti-Dipp IgG and for a validated, in-clinic commercial antibody diagnostic kit for cats. Two cats were also found positive for circulating antigens of adult female worm. Anti-WSPr IgG were found in five of nine anti-Dipp IgG-positive sera and from eight ELISADipp-negative sera. Our results confirm the strong IgG response in heartworm infected cats and demonstrate the involvement of the Wolbachia endosymbiont in the immune reaction to the parasite both in experimentally infected cats and in cats exposed to a high risk of natural infection.}, }
@article {pmid15479245, year = {2004}, author = {Gil, R and Latorre, A and Moya, A}, title = {Bacterial endosymbionts of insects: insights from comparative genomics.}, journal = {Environmental microbiology}, volume = {6}, number = {11}, pages = {1109-1122}, doi = {10.1111/j.1462-2920.2004.00691.x}, pmid = {15479245}, issn = {1462-2912}, mesh = {Adaptation, Biological ; Animals ; Bacteria/*genetics/isolation &amp; purification ; *Bacterial Physiological Phenomena ; Biological Evolution ; Genome, Bacterial ; Insecta/*microbiology ; *Symbiosis ; }, abstract = {The development of molecular techniques for the study of uncultured bacteria allowed the extensive study of the widespread association between insects and intracellular symbiotic bacteria. Most of the bacterial endosymbionts involved in such associations are gamma-proteobacteria, closely related to Escherichia coli. In recent years, five genomes from insect endosymbionts have been sequenced, allowing the performance of extensive genome comparative analysis that, as a complement of phylogenetic studies, and analysis on individual genes, can help to understand the different traits of this particular association, including how the symbiotic process is established, the explanation of the special features of these microbial genomes, the bases of this intimate association and the possible future that awaits the endosymbionts with extremely reduced genomes.}, }
@article {pmid15470245, year = {2004}, author = {Patron, NJ and Rogers, MB and Keeling, PJ}, title = {Gene replacement of fructose-1,6-bisphosphate aldolase supports the hypothesis of a single photosynthetic ancestor of chromalveolates.}, journal = {Eukaryotic cell}, volume = {3}, number = {5}, pages = {1169-1175}, pmid = {15470245}, issn = {1535-9778}, mesh = {Base Sequence ; *Biological Evolution ; DNA/genetics ; Fructose-Bisphosphate Aldolase/classification/*genetics ; Models, Genetic ; Photosynthesis/*genetics ; Phylogeny ; Plastids/enzymology/genetics ; Rhodophyta/*genetics/*metabolism ; Symbiosis/genetics ; }, abstract = {Plastids (photosynthetic organelles of plants and algae) are known to have spread between eukaryotic lineages by secondary endosymbiosis, that is, by the uptake of a eukaryotic alga by another eukaryote. But the number of times this has taken place is controversial. This is particularly so in the case of eukaryotes with plastids derived from red algae, which are numerous and diverse. Despite their diversity, it has been suggested that all these eukaryotes share a recent common ancestor and that their plastids originated in a single endosymbiosis, the so-called "chromalveolate hypothesis." Here we describe a novel molecular character that supports the chromalveolate hypothesis. Fructose-1,6-bisphosphate aldolase (FBA) is a glycolytic and Calvin cycle enzyme that exists as two nonhomologous types, class I and class II. Red algal plastid-targeted FBA is a class I enzyme related to homologues from plants and green algae, and it would be predicted that the plastid-targeted FBA from algae with red algal secondary endosymbionts should be related to this class I enzyme. However, we show that plastid-targeted FBA of heterokonts, cryptomonads, haptophytes, and dinoflagellates (all photosynthetic chromalveolates) are class II plastid-targeted enzymes, completely unlike those of red algal plastids. The chromalveolate enzymes form a strongly supported group in FBA phylogeny, and their common possession of this unexpected plastid characteristic provides new evidence for their close relationship and a common origin for their plastids.}, }
@article {pmid15462567, year = {2004}, author = {Gamarra-Luques, CD and Vega, IA and Koch, E and Castro-Vazquez, A}, title = {Intrahost distribution and transmission of a new species of cyclopoid copepod endosymbiotic to a freshwater snail, Pomacea canaliculata (Caenogastropoda, Ampullariidae), from Argentina.}, journal = {Biocell : official journal of the Sociedades Latinoamericanas de Microscopia Electronica ... et. al}, volume = {28}, number = {2}, pages = {155-164}, pmid = {15462567}, issn = {0327-9545}, mesh = {Animals ; Argentina ; Copepoda/*anatomy &amp; histology/*classification/*physiology ; Female ; Host-Parasite Interactions ; Male ; Penis/parasitology ; Population Density ; Sex Ratio ; Snails/parasitology/*physiology ; *Symbiosis ; }, abstract = {A new species of cyclopoid copepod, Ozmana huarpium, is described as a symbiont to Pomacea canaliculata (Lamarck 1822) (Caenogastropoda, Ampullariidae). Rather large numbers (about one hundred copepods per snail) were found, although there was no evidence of harm to the host. To our knowledge, O. haemophila (symbiont to P. maculata), and the currently described species, O. huarpium, are the only copepod species ever recorded as endosymbionts to freshwater invertebrates. While O. haemophila is restricted to the haemocoel of its host, O. huarpium predominate in the penis sheath, the ctenidium and the mantle cavity, figuring in these pallial organs 63-65% of total mature forms. The sex ratio of the symbiont is skewed to the female side in these organs, specially in male hosts. The hypothesis that a special female tropism for the male host's pallial organs might ensure interindividual transmission of the symbiont was tested, with indications that the symbiont is mainly transmitted during copulation.}, }
@article {pmid15461428, year = {2004}, author = {Kilian, O and Kroth, PG}, title = {Presequence acquisition during secondary endocytobiosis and the possible role of introns.}, journal = {Journal of molecular evolution}, volume = {58}, number = {6}, pages = {712-721}, pmid = {15461428}, issn = {0022-2844}, mesh = {Algal Proteins/*genetics/metabolism ; Amino Acid Sequence ; Cell Nucleus/genetics/physiology ; DNA, Complementary/genetics ; Diatoms/*genetics/physiology ; Electrophoresis, Agar Gel ; *Evolution, Molecular ; Gene Library ; Gene Transfer, Horizontal/genetics ; Green Fluorescent Proteins ; Introns/genetics ; Luminescent Proteins/metabolism ; Molecular Sequence Data ; Oligonucleotides ; Phylogeny ; Plastids/genetics ; Polymerase Chain Reaction ; Protein Sorting Signals/genetics/*physiology ; Protein Transport/*physiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Targeting of nucleus-encoded proteins into chloroplasts is mediated by N-terminal presequences. During evolution of plastids from formerly free-living cyanobacteria by endocytobiosis, genes for most plastid proteins have been transferred from the plastid genome to the nucleus and subsequently had to be equipped with such plastid targeting sequences. So far it is unclear how the gene domains coding for presequences and the respective mature proteins may have been assembled. While land plant plastids are supposed to originate from a primary endocytobiosis event (a prokaryotic cyanobacterium was taken up by a eukaryotic cell), organisms with secondary plastids like diatoms experienced a second endocytobiosis step involving a eukaryotic alga taken up by a eukaryotic host cell. In this group of algae, apparently most genes encoding chloroplast proteins have been transferred a second time (from the nucleus of the endosymbiont to the nucleus of the secondary host) and thus must have been equipped with additional targeting signals. We have analyzed cDNAs and the respective genomic DNA fragments of seven plastid preproteins from the diatom Phaeodactylum tricornutum. In all of these genes we found single spliceosomal introns, generally located within the region coding for the N-terminal plastid targeting sequences or shortly downstream of it. The positions of the introns can be related to the putative phylogenetic histories of the respective genes, indicating that the bipartite targeting sequences in these secondary algae might have evolved by recombination events via introns.}, }
@article {pmid15388756, year = {2004}, author = {Moreira, D and López-García, P and Vickerman, K}, title = {An updated view of kinetoplastid phylogeny using environmental sequences and a closer outgroup: proposal for a new classification of the class Kinetoplastea.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {54}, number = {Pt 5}, pages = {1861-1875}, doi = {10.1099/ijs.0.63081-0}, pmid = {15388756}, issn = {1466-5026}, mesh = {Animals ; DNA, Protozoan/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry/isolation &amp; purification ; Genes, rRNA ; Kinetoplastida/*classification/*genetics/isolation &amp; purification ; Molecular Sequence Data ; *Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal, 18S/genetics ; Seawater/parasitology ; Sequence Analysis, DNA ; Trypanosomatina/classification/genetics ; }, abstract = {Given their ecological and medical importance, the classification of the kinetoplastid protists (class Kinetoplastea) has attracted much scientific attention for a long time. Morphology-based taxonomic schemes distinguished two major kinetoplastid groups: the strictly parasitic, uniflagellate trypanosomatids and the biflagellate bodonids. Molecular phylogenetic analyses based on 18S rRNA sequence comparison suggested that the trypanosomatids emerged from within the bodonids. However, these analyses revealed a huge evolutionary distance between the kinetoplastids and their closest relatives (euglenids and diplonemids) that makes very difficult the correct inference of the phylogenetic relationships between the different kinetoplastid groups. Using direct PCR amplification of 18S rRNA genes from hydrothermal vent samples, several new kinetoplastid-like sequences have been reported recently. Three of them emerge robustly at the base of the kinetoplastids, breaking the long branch leading to the euglenids and diplonemids. One of these sequences belongs to a close relative of Ichthyobodo necator (a fish parasite) and of the 'Perkinsiella amoebae'-like endosymbiont of Neoparamoeba spp. amoebae. The authors have studied the reliability of their basal position and used all these slow-evolving basal-emerging sequences as a close outgroup to analyse the phylogeny of the apical kinetoplastids. They thus find a much more stable and resolved kinetoplastid phylogeny, which supports the monophyly of groups that very often emerged as polyphyletic in the trees rooted using the traditional, distant outgroup sequences. A new classification of the class Kinetoplastea is proposed based on the results of the phylogenetic analysis presented. This class is now subdivided into two new subclasses, Prokinetoplastina (accommodating the basal species I. necator and 'Perkinsiella amoebae') and Metakinetoplastina (containing the Trypanosomatida together with three additional new orders: Eubodonida, Parabodonida and Neobodonida). The classification of the species formerly included in the genus Bodo is also revised, with the amendment of this genus and the genus Parabodo and the creation of a new genus, Neobodo.}, }
@article {pmid15375721, year = {2004}, author = {Bodył, A}, title = {Evolutionary origin of a preprotein translocase in the periplastid membrane of complex plastids: a hypothesis.}, journal = {Plant biology (Stuttgart, Germany)}, volume = {6}, number = {5}, pages = {513-518}, doi = {10.1055/s-2004-821092}, pmid = {15375721}, issn = {1435-8603}, mesh = {Biological Evolution ; Cell Compartmentation ; Eukaryota/genetics/metabolism ; Intracellular Membranes/metabolism ; Membrane Transport Proteins/*genetics ; Mitochondrial Proteins/genetics/metabolism ; Models, Biological ; Plastids/*genetics/*metabolism ; Symbiosis ; }, abstract = {Plastids with four envelope membranes have evolved from red and green algae engulfed by phagotrophic protozoans. It is assumed that the Sec translocon resides in their outermost membrane, while in the two innermost membranes the Toc-Tic supercomplex is embedded. However, such a single Sec/single Toc-Tic model cannot explain the passage of proteins across the second (or periplastid) membrane which represents the endosymbiont plasmalemma. One of the most recent models postulates that this membrane contains the Toc75 channel which was relocated here from the endosymbiont plastid. Unfortunately, the precursor of this protein carries a bipartite presequence, which means that its insertion into the new membrane would require relocation and/or modification of two different processing peptidases. I suggest that these obstacles can be easily bypassed by the assumption that the mitochondrial Tim23 channel was inserted into the endosymbiont plasmalemma. In contrast to Toc75, this protein has an internal, uncleavable targeting signal and its insertion into the new membrane would require neither relocation nor modification of additional proteins. Besides, such a relocated Tim23 channel could import not only plastid, but also mitochondrial proteins. I hypothesize that from the latter proteins, initially directed to the endosymbiont mitochondrion, periplastid proteins have evolved which are now targeted to the former cytosol and/or nucleus of the eukaryotic algal endosymbiont.}, }
@article {pmid15375144, year = {2004}, author = {Gómez-Valero, L and Soriano-Navarro, M and Pérez-Brocal, V and Heddi, A and Moya, A and García-Verdugo, JM and Latorre, A}, title = {Coexistence of Wolbachia with Buchnera aphidicola and a secondary symbiont in the aphid Cinara cedri.}, journal = {Journal of bacteriology}, volume = {186}, number = {19}, pages = {6626-6633}, pmid = {15375144}, issn = {0021-9193}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/genetics/*isolation &amp; purification ; DNA, Ribosomal/chemistry ; Microscopy, Electron ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Wolbachia/genetics/*isolation &amp; purification ; }, abstract = {Intracellular symbiosis is very common in the insect world. For the aphid Cinara cedri, we have identified by electron microscopy three symbiotic bacteria that can be characterized by their different sizes, morphologies, and electrodensities. PCR amplification and sequencing of the 16S ribosomal DNA (rDNA) genes showed that, in addition to harboring Buchnera aphidicola, the primary endosymbiont of aphids, C. cedri harbors a secondary symbiont (S symbiont) that was previously found to be associated with aphids (PASS, or R type) and an alpha-proteobacterium that belongs to the Wolbachia genus. Using in situ hybridization with specific bacterial probes designed for symbiont 16S rDNA sequences, we have shown that Wolbachia was represented by only a few minute bacteria surrounding the S symbionts. Moreover, the observed B. aphidicola and the S symbionts had similar sizes and were housed in separate specific bacterial cells, the bacteriocytes. Interestingly, in contrast to the case for all aphids examined thus far, the S symbionts were shown to occupy a similarly sized or even larger bacteriocyte space than B. aphidicola. These findings, along with the facts that C. cedri harbors the B. aphidicola strain with the smallest bacterial genome and that the S symbionts infect all Cinara spp. analyzed so far, suggest the possibility of bacterial replacement in these species.}, }
@article {pmid15352321, year = {2004}, author = {Motta, MC and Picchi, GF and Palmié-Peixoto, IV and Rocha, MR and de Carvalho, TM and Morgado-Diaz, J and de Souza, W and Goldenberg, S and Fragoso, SP}, title = {The microtubule analog protein, FtsZ, in the endosymbiont of trypanosomatid protozoa.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {4}, pages = {394-401}, doi = {10.1111/j.1550-7408.2004.tb00386.x}, pmid = {15352321}, issn = {1066-5234}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/*chemistry ; Bacterial Proteins/*analysis/genetics ; Cloning, Molecular ; Crithidia/*chemistry/microbiology/ultrastructure ; Cytoskeletal Proteins/*analysis/genetics ; Fluorescent Antibody Technique ; Microscopy, Fluorescence ; Microscopy, Immunoelectron ; Molecular Sequence Data ; Polymerase Chain Reaction ; Protozoan Proteins/*analysis/genetics ; Pseudomonas/chemistry ; Sequence Homology ; Symbiosis ; Trypanosomatina/*chemistry/microbiology/ultrastructure ; }, abstract = {Blastocrithidia culicis and Crithidia deanei are trypanosomatids that harbor an endosymbiotic bacterium in their cytoplasm. In prokaryotes, numerous proteins are essential for cell division, such as FtsZ, which is encoded by filament-forming temperature-sensitive (fts) genes. FtsZ is the prokaryotic homolog of eukaryotic tubulin and is present in bacteria and archaea, and has also been identified in mitochondria and chloroplasts. FtsZ plays a key role in the initiation of cytokinesis. It self-assembles into the Z ring, which establishes the division plane during septation. In this study, immunoblotting analysis using a FtsZ polyclonal antibody, revealed a 40-kDa band characteristic of FtsZ in endosymbiont fractions and in whole trypanosomatid homogenates, but not in whole cell extracts of aposymbiotic strains. Confocal microscopy and ultrastructural analysis revealed a specific and dispersed labeling over the endosymbiont. Bars and ring-like structures, which are suggestive of the presence of Z-rings, were never observed, even during the division of the symbiont. This peculiar distribution of FtsZ may represent an arrangement of cytoskeleton protein intermediate between prokaryotic and eukaryotic cells. The endosymbiont ftsz gene was completely sequenced after amplification of DNA from symbiont-bearing trypanosomatids or from pure endosymbiont fractions, using PCR and specific primers. The sequences obtained from the endosymbionts from C. deanei and B. culicis were very similar, and were most closely related to bacteria from the genus Pseudomonas.}, }
@article {pmid15329721, year = {2004}, author = {Montoya, JP and Holl, CM and Zehr, JP and Hansen, A and Villareal, TA and Capone, DG}, title = {High rates of N2 fixation by unicellular diazotrophs in the oligotrophic Pacific Ocean.}, journal = {Nature}, volume = {430}, number = {7003}, pages = {1027-1032}, doi = {10.1038/nature02824}, pmid = {15329721}, issn = {1476-4687}, mesh = {Bacteria/*metabolism ; Cyanobacteria/metabolism ; Hawaii ; Nitrates/metabolism ; Nitrogen/*metabolism ; *Nitrogen Fixation ; Pacific Ocean ; Plankton/*metabolism ; Seawater/*chemistry/*microbiology ; Symbiosis ; }, abstract = {The availability of nitrogen is important in regulating biological productivity in marine environments. Deepwater nitrate has long been considered the major source of new nitrogen supporting primary production in oligotrophic regions of the open ocean, but recent studies have showed that biological N2 fixation has a critical role in supporting oceanic new production. Large colonial cyanobacteria in the genus Trichodesmium and the heterocystous endosymbiont Richelia have traditionally been considered the dominant marine N2 fixers, but unicellular diazotrophic cyanobacteria and bacterioplankton have recently been found in the picoplankton and nanoplankton community of the North Pacific central gyre, and a variety of molecular and isotopic evidence suggests that these unicells could make a major contribution to the oceanic N budget. Here we report rates of N2 fixation by these small, previously overlooked diazotrophs that, although spatially variable, can equal or exceed the rate of N2 fixation reported for larger, more obvious organisms. Direct measurements of 15N2 fixation by small diazotrophs in various parts of the Pacific Ocean, including the waters off Hawaii where the unicellular diazotrophs were first characterized, show that N2 fixation by unicellular diazotrophs can support a significant fraction of total new production in oligotrophic waters.}, }
@article {pmid15322925, year = {2004}, author = {Foster, J and Baldo, L and Blaxter, M and Henkle-Dührsen, K and Whitton, C and Slatko, B and Bandi, C}, title = {The bacterial catalase from filarial DNA preparations derives from common pseudomonad contaminants and not from Wolbachia endosymbionts.}, journal = {Parasitology research}, volume = {94}, number = {2}, pages = {141-146}, pmid = {15322925}, issn = {0932-0113}, mesh = {Animals ; Catalase/*genetics ; DNA, Bacterial/analysis/*genetics ; DNA, Helminth/analysis/*genetics ; DNA, Ribosomal/analysis ; Filarioidea/genetics/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Pseudomonas/*enzymology/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*enzymology/genetics ; }, abstract = {Wolbachia are obligatory endosymbionts in many species of filarial nematodes. Certain bacterial molecules induce antibody responses in mammalian hosts infected with filariae, while others activate inflammatory responses that contribute to pathology. These findings, coupled with antibiotic studies demonstrating the dependence of filarial embryogenesis on the presence of Wolbachia, have intensified research on Wolbachia-nematode interactions, and the effects of Wolbachia molecules on the mammalian immune system. By amplification and sequencing of 16S rDNA and catalase sequences, we show that filarial DNA samples prepared from nematodes collected under typical conditions are frequently contaminated with Pseudomonas DNA. Analysis of a published DNA fragment containing a catalase attributed to the Wolbachia of Onchocerca volvulus showed it to be most like Pseudomonas, both in terms of sequence similarity and genomic organization. Additionally, there was no obvious catalase in either of two available Wolbachia genome sequences. Contamination of filarial DNA with bacterial sequences other than Wolbachia can complicate studies of the role of these symbionts in filarial biology.}, }
@article {pmid15317875, year = {2004}, author = {Gómez-Valero, L and Latorre, A and Silva, FJ}, title = {The evolutionary fate of nonfunctional DNA in the bacterial endosymbiont Buchnera aphidicola.}, journal = {Molecular biology and evolution}, volume = {21}, number = {11}, pages = {2172-2181}, doi = {10.1093/molbev/msh232}, pmid = {15317875}, issn = {0737-4038}, mesh = {Buchnera/*genetics ; DNA/genetics/metabolism ; DNA, Bacterial/*genetics ; Escherichia coli/genetics ; Evolution, Molecular ; Gene Deletion ; Genome, Bacterial ; Models, Genetic ; Sequence Analysis, DNA ; Species Specificity ; Time Factors ; }, abstract = {Reduction of the genome size in endosymbiotic bacteria is the main feature linked to the adaptation to a host-associated lifestyle. We have analyzed the fate of the nonfunctional DNA in Buchnera aphidicola, the primary endosymbiont of aphids. At least 164 gene losses took place during the recent evolution of three B. aphidicola strains, symbionts of the aphids Acyrthosiphon pisum (BAp), Schizaphis graminum (BSg), and Baizongia pistacia (BBp). A typical pattern starts with the inactivation of a gene, which produces a pseudogene, and is followed by the progressive loss of its DNA. Our results show that during the period from the separation of the Aphidinae and Pemphiginae lineages (86-164 MYA) to the divergence of BAp and BSg (50-70 MYA) the half-life of a pseudogene was 23.9 Myr. For the remaining periods of evolution, the ranges of values obtained for this parameter are of the same order of magnitude. These results have revealed that a gene inactivated during B. aphidicola evolution requires 40-60 Myr to become almost completely disintegrated. Moreover, we have shown a positive correlation between the decrease in the GC content and the DNA loss for these nonfunctional DNA regions. When gene losses are classified, based on the detection of a pseudogene or otherwise of an absent gene in the modern B. aphidicola genomes, we have observed a drastic reduction of DNA length in the latter versus the former relative to the functional gene. Finally, we have also detected a slight reduction in size of the intergenic regions in the three B. aphidicola strains, when they are compared with the size of the close relative Escherichia coli.}, }
@article {pmid15316720, year = {2004}, author = {Schwedock, J and Harmer, TL and Scott, KM and Hektor, HJ and Seitz, AP and Fontana, MC and Distel, DL and Cavanaugh, CM}, title = {Characterization and expression of genes from the RubisCO gene cluster of the chemoautotrophic symbiont of Solemya velum: cbbLSQO.}, journal = {Archives of microbiology}, volume = {182}, number = {1}, pages = {18-29}, doi = {10.1007/s00203-004-0689-x}, pmid = {15316720}, issn = {0302-8933}, mesh = {Animals ; Bacteria/*enzymology/genetics ; Bacterial Proteins/genetics/*metabolism ; Carrier Proteins/chemistry/genetics/*metabolism ; Mollusca/*microbiology ; Multigene Family ; Ribulose-Bisphosphate Carboxylase/genetics/*metabolism ; *Symbiosis ; }, abstract = {Chemoautotrophic endosymbionts residing in Solemya velum gills provide this shallow water clam with most of its nutritional requirements. The cbb gene cluster of the S. velum symbiont, including cbbL and cbbS, which encode the large and small subunits of the carbon-fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), was cloned and expressed in Escherichia coli. The recombinant RubisCO had a high specific activity, approximately 3 micromol min(-1) mg protein (-1), and a KCO2 of 40.3 microM. Based on sequence identity and phylogenetic analyses, these genes encode a form IA RubisCO, both subunits of which are closely related to those of the symbiont of the deep-sea hydrothermal vent gastropod Alviniconcha hessleri and the photosynthetic bacterium Allochromatium vinosum. In the cbb gene cluster of the S. velum symbiont, the cbbLS genes were followed by cbbQ and cbbO, which are found in some but not all cbb gene clusters and whose products are implicated in enhancing RubisCO activity post-translationally. cbbQ shares sequence similarity with nirQ and norQ, found in denitrification clusters of Pseudomonas stutzeri and Paracoccus denitrificans. The 3' region of cbbO from the S. velum symbiont, like that of the three other known cbbO genes, shares similarity to the 3' region of norD in the denitrification cluster. This is the first study to explore the cbb gene structure for a chemoautotrophic endosymbiont, which is critical both as an initial step in evaluating cbb operon structure in chemoautotrophic endosymbionts and in understanding the patterns and forces governing RubisCO evolution and physiology.}, }
@article {pmid15315893, year = {2004}, author = {Terry, RS and Smith, JE and Sharpe, RG and Rigaud, T and Littlewood, DT and Ironside, JE and Rollinson, D and Bouchon, D and MacNeil, C and Dick, JT and Dunn, AM}, title = {Widespread vertical transmission and associated host sex-ratio distortion within the eukaryotic phylum Microspora.}, journal = {Proceedings. Biological sciences}, volume = {271}, number = {1550}, pages = {1783-1789}, pmid = {15315893}, issn = {0962-8452}, mesh = {Amphipoda/*parasitology ; Animals ; Base Sequence ; Bayes Theorem ; Female ; Host-Parasite Interactions ; Male ; Microsporidia/*genetics ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; Sex Differentiation/*physiology ; Sex Factors ; *Sex Ratio ; Species Specificity ; }, abstract = {Vertical transmission (VT) and associated manipulation of host reproduction are widely reported among prokaryotic endosymbionts. Here, we present evidence for widespread use of VT and associated sex-ratio distortion in a eukaryotic phylum. The Microspora are an unusual and diverse group of eukaryotic parasites that infect all animal phyla. Following our initial description of a microsporidian that feminizes its crustacean host, we survey the diversity and distribution of VT within the Microspora. We find that vertically transmitted microsporidia are ubiquitous in the amphipod hosts sampled and that they are also diverse, with 11 species of microsporidia detected within 16 host species. We found that infections were more common in females than males, suggesting that host sex-ratio distortion occurs in five out of eight parasite species tested. Phylogenetic reconstruction demonstrates that VT occurs in all major lineages of the phylum Microspora and that sex-ratio distorters are found on multiple branches of the phylogenetic tree. We propose that VT is either an ancestral trait or evolves with peculiar frequency in this phylum. If the association observed here between VT and host sex-ratio distortion holds true across other host taxa, these eukaryotic parasites may join the bacterial endosymbionts in their importance as sex-ratio distorters.}, }
@article {pmid15313549, year = {2004}, author = {Fares, MA and Moya, A and Barrio, E}, title = {GroEL and the maintenance of bacterial endosymbiosis.}, journal = {Trends in genetics : TIG}, volume = {20}, number = {9}, pages = {413-416}, doi = {10.1016/j.tig.2004.07.001}, pmid = {15313549}, issn = {0168-9525}, mesh = {*Bacterial Physiological Phenomena ; Chaperonin 60/*physiology ; Symbiosis/*physiology ; }, abstract = {Many eukaryotic organisms have symbiotic associations with obligate intracellular bacteria. The clonal transmission of endosymbionts between host generations should lead to the irreversible fixation of slightly deleterious mutations in their non-recombinant genome by genetic drift. However, the stability of endosymbiosis indicates that some mechanism is involved in the amelioration of the effects of these mutations. We propose that the chaperone GroEL was involved in the acquisition of an endosymbiotic lifestyle not only by means of its over-production, as proposed by Moran, but also by its adaptive evolution mediated by positive selection to improve the interaction with the unstable endosymbiont proteome.}, }
@article {pmid15311460, year = {2004}, author = {Tsai, KH and Lien, JC and Huang, CG and Wu, WJ and Chen, WJ}, title = {Molecular (sub) grouping of endosymbiont Wolbachia infection among mosquitoes of Taiwan.}, journal = {Journal of medical entomology}, volume = {41}, number = {4}, pages = {677-683}, doi = {10.1603/0022-2585-41.4.677}, pmid = {15311460}, issn = {0022-2585}, mesh = {Animals ; Anopheles/microbiology ; Base Sequence ; Culex/microbiology ; Culicidae/classification/growth &amp; development/*microbiology ; DNA Primers ; DNA, Bacterial/genetics/isolation &amp; purification ; Female ; Larva/microbiology ; Ovary/microbiology ; Parthenogenesis ; Taiwan ; Wolbachia/*classification/genetics/isolation &amp; purification ; }, abstract = {Wolbachia are maternally inherited bacteria that infect a wide range of arthropods as well as filarial worms. The infection usually results in reproductive distortions of the host, primarily cytoplasmic incompatibility, parthenogenesis, and feminization. This study showed that Wolbachia infection (15/29; 51.72%) was prevalent among field-caught mosquitoes in Taiwan. Three mosquito species were identified as having Wolbachia A infection, eight species as having Wolbachia B, and four other species were dually infected by both groups. Each Wolbachia isolate from different mosquitoes was further divided into a specific subgroup. However, there were still some isolates that did not belong to any known subgroup, suggesting that more subgroups remain to be identified. Investigation of tissue tropism in either Aedes albopictus (Skuse) or Armigeres subalbatus (Coquillett) revealed that Wolbachia were extensively distributed within the host, although the ovary was most susceptible to infection. This report provides preliminary features of molecular relationships among Wolbachia groups of mosquitoes from Taiwan.}, }
@article {pmid15305681, year = {2004}, author = {Sacchi, L}, title = {[Ultrastructural basis of interactions between prokaryotes and eukaryotes in different symbiotic models].}, journal = {Parassitologia}, volume = {46}, number = {1-2}, pages = {19-24}, pmid = {15305681}, issn = {0048-2951}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Bdellovibrio/physiology/ultrastructure ; Biological Evolution ; Brugia pahangi/microbiology/ultrastructure ; Cockroaches/cytology/embryology/microbiology ; Eggs/microbiology ; Eukaryotic Cells/*ultrastructure ; Fat Body/microbiology ; Female ; Filarioidea/cytology/*microbiology ; Hemocytes/microbiology ; Insecta/cytology/*microbiology ; Isoptera/cytology/microbiology ; Models, Biological ; Ovary/microbiology ; Prokaryotic Cells/*ultrastructure ; *Symbiosis ; Ticks/cytology/*microbiology ; Wolbachia/physiology/ultrastructure ; }, abstract = {This paper reviews the Author's contribution to the knowledge of the ultrastructural basis of the prokaryote-eukaryote interactions in different models assessed by an ultrastructural approach. In agreement with the hypothesis of the origin of eukaryotic cells, which are chimeras of several prokaryotes with different morpho-functional specializations, symbiosis had major consequence for evolution of life. In Arthropods, one of the most successful lifestyles, the presence of endosymbiotic prokaryotes, plays an important role in their metabolism. In some cases, genome integration has occurred in the endosymbiotic relationships with the host, proving that intracellular symbiosis is not merely a nutritional supplement. Intracellular symbiotic bacteria are also described in nematodes. In particular, the presence of intracellular Wolbachia in filariae, even if its function is not yet completely known, influences positively the reproductive biology and the survival of the host, as proved by antibiotic treatment against this bacterium. The ultrastructural images reported in this review were obtained using different species of cockroaches, termites, ticks and filarial nematodes. The traditional methods of transmission (TEM), scansion (SEM) and immuno electron microscopy were used. In addition, also freeze-fracture and deep-etching techniques were employed. The cockroaches and the primitive termite Mastotermes darwiniensis host symbiotic bacteria in the ovary and in specialized cells (bacteriocytes) of the fat body. These bacteria have the typical cell boundary profile of gram-negative bacteria and are enveloped in a vacuolar membrane produced by the host cell. Molecular sequence data of 16S rDNA of endosymbionts of five species of cockroaches and M. darwiniensis indicate that they are members of the Flavobacteria-bacteroides group and that the infection occurred in an ancestor common to cockroaches and termites probably after the end of the Paleozoic (250 Ma BP). The symbiotic bacteria are transmitted transovarially and, during embryogenesis, they are integrated into the morphogenetic processes. In particular, we were able to demonstrate that the origin of the bacteriocyte should be looked for in the cells of the haemocyte line (embryonic plasmatocytes). The eggs are infected by the bacteria emerging from the bacteriocytes of the ovaric fat body and, at the end of the vitellogenesis, they are actively phagocytized by the egg membrane. In filarial nematodes, intracellular bacteria belonging to the genus Wolbachia have been described: they have evolved an obligatory mutualistic association with their host. In fact, antibiotic treatments lead to the clearance of bacteria and this loss produces a negative impact on reproduction and survival of the filarial host. We evidenced, by TEM, the degenerative events occurring during the embriogenesis of Brugia pahangi and Dirofilaria immitis after tetracycline treatment. The data suggest that the Wolbachia play a direct role in worm metabolism. Finally, a new additional model of the prokaryote-eukaryote interaction has been described: we have recently discovered a new intracellular alpha-proteobacterium, named Iric ES1, which resides in the ovarian tissues of the tick Ixodes ricinus. The intriguing characteristic of this bacterium is its ability to invade and consume the ovaric mitochondria. From an evolutionary perspective, it is interesting to note that Iric ES1 enters mitochondria in a similar way to that employed by the "predatory" bacterium Bdellovibrio bacteriovorus.}, }
@article {pmid15297923, year = {2004}, author = {Ruang-areerate, T and Kittayapong, P and McGraw, EA and Baimai, V and O'Neill, SL}, title = {Wolbachia replication and host cell division in Aedes albopictus.}, journal = {Current microbiology}, volume = {49}, number = {1}, pages = {10-12}, doi = {10.1007/s00284-003-4245-8}, pmid = {15297923}, issn = {0343-8651}, mesh = {Aedes/cytology/*microbiology ; Animals ; Cell Division/physiology ; DNA Replication ; Host-Parasite Interactions/immunology ; Symbiosis/*physiology ; Virulence ; Wolbachia/growth &amp; development/pathogenicity/*physiology ; }, abstract = {Wolbachia pipientis is an obligate intracellular endosymbiont of a range of arthropod species. The microbe is best known for its manipulations of host reproduction that include inducing cytoplasmic incompatibility, parthenogenesis, feminization, and male-killing. Like other vertically transmitted intracellular symbionts, Wolbachia's replication rate must not outpace that of its host cells if it is to remain benign. The mosquito Aedes albopictus is naturally infected both singly and doubly with different strains of Wolbachia pipientis. During diapause in mosquito eggs, no host cell division is believed to occur. Further development is triggered only by subsequent exposure of the egg to water. This study uses diapause in Wolbachia-infected Aedes albopictus eggs to determine whether symbiont replication slows or stops when host cell division ceases or whether it continues at a low but constant rate. We have shown that Wolbachia densities in eggs are greatest during embryonation and then decline throughout diapause, suggesting that Wolbachia replication is dependent on host cell replication.}, }
@article {pmid15291971, year = {2004}, author = {Thao, ML and Baumann, L and Baumann, P}, title = {Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha).}, journal = {BMC evolutionary biology}, volume = {4}, number = {}, pages = {25}, pmid = {15291971}, issn = {1471-2148}, mesh = {Animals ; Anticodon/genetics ; Aphids/*genetics ; Chromosome Deletion ; DNA, Mitochondrial/genetics ; Electron Transport Complex IV/genetics ; Evolution, Molecular ; Gene Order/genetics ; Genes, Insect/genetics ; *Genome ; Hemiptera/*genetics ; Mitochondria/*genetics ; NADH Dehydrogenase/genetics ; Polymerase Chain Reaction/methods ; Protein Subunits/genetics ; RNA, Transfer, Ala/genetics ; RNA, Transfer, Arg/genetics ; RNA, Transfer, Asn/genetics ; RNA, Transfer, Gly/genetics ; RNA, Untranslated/genetics ; Recombination, Genetic/genetics ; Sequence Analysis, DNA/methods ; }, abstract = {BACKGROUND: With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids.<br><br>RESULTS: We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII)-tRNAgly-NADH dehydrogenase subunit 3(ND3)-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types.<br><br>CONCLUSIONS: In whiteflies, the region of the mitochondrial genome consisting of genes encoding for COIII-tRNAgly-ND3-tRNAala-tRNAarg-tRNAasn can be transposed from its ancestral position to four different locations on the mitochondrial genome. Related species within clusters established by phylogenetic analysis of host and endosymbiont genes have the same mitochondrial gene arrangement indicating a transposition in the ancestor of these clusters.}, }
@article {pmid15287587, year = {2004}, author = {McGarry, HF and Egerton, GL and Taylor, MJ}, title = {Population dynamics of Wolbachia bacterial endosymbionts in Brugia malayi.}, journal = {Molecular and biochemical parasitology}, volume = {135}, number = {1}, pages = {57-67}, doi = {10.1016/j.molbiopara.2004.01.006}, pmid = {15287587}, issn = {0166-6851}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Brugia malayi/genetics/isolation &amp; purification/*microbiology ; Colony Count, Microbial ; Culicidae/parasitology ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/analysis ; DNA, Helminth/analysis ; Genes, Bacterial ; Genes, Helminth ; Gerbillinae/parasitology ; Microscopy, Electron ; Polymerase Chain Reaction ; Population Dynamics ; Symbiosis ; Wolbachia/genetics/*growth &amp; development ; }, abstract = {The human filarial nematode Brugia malayi contains an endosymbiotic bacterium, Wolbachia. We used real-time quantitative polymerase chain reaction (QPCR) and microscopy to investigate the population dynamics of the bacterium-nematode association. Two Wolbachia (wsp and ftsZ) and one nematode (gst) genes were amplified from all life-cycle stages of B. malayi and results expressed as gene copies per worm and as Wolbachia/nematode ratios. Since the genes were single copy and there was one genome per Wolbachia, the gene copy numbers were equivalent to the numbers of bacteria. These were similar in microfilariae and the mosquito-borne larval stages (L2 and L3), with the lowest ratios of Wolbachia/nematode DNA. However, within 7 days of infection of the mammalian host, bacteria had increased 600-fold and the bacteria/worm ratio was the highest of all life-cycle stages. The rapid multiplication continued throughout L4 development, so that the major period of bacterial population growth occurred within 4 weeks of infection of the definitive host. Microscopy confirmed that there were few bacteria in mosquito-derived L3 but many, in large groups, in L4 collected 9 and 21 days after infection. In adult male worms up to 15 months of age, the bacterial populations were maintained, whilst in females, bacteria numbers increased as the worms matured and as the ovary and embryonic larval stages became infected. These results support the hypothesis that the bacteria are essential for larval development in the mammalian host and for the long-term survival of adult worms.}, }
@article {pmid15280284, year = {2004}, author = {Vannini, C and Rosati, G and Verni, F and Petroni, G}, title = {Identification of the bacterial endosymbionts of the marine ciliate Euplotes magnicirratus (Ciliophora, Hypotrichia) and proposal of 'Candidatus Devosia euplotis'.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {54}, number = {Pt 4}, pages = {1151-1156}, doi = {10.1099/ijs.0.02759-0}, pmid = {15280284}, issn = {1466-5026}, mesh = {Animals ; Cytoplasm/microbiology ; DNA Probes ; DNA, Bacterial/chemistry/isolation &amp; purification ; DNA, Ribosomal/chemistry ; Euplotes/*microbiology/ultrastructure ; Genes, rRNA ; Hyphomicrobiaceae/*classification/genetics/*isolation &amp; purification/physiology ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Seawater/microbiology ; Sensitivity and Specificity ; Sequence Analysis, DNA ; Sequence Homology ; *Symbiosis ; Vacuoles/microbiology ; Water Microbiology ; }, abstract = {This paper reports the identification of bacterial endosymbionts that inhabit the cytoplasm of the marine ciliated protozoon Euplotes magnicirratus. Ultrastructural and full-cycle rRNA approaches were used to reveal the identity of these bacteria. Based on analysis of 16S rRNA gene sequences, evolutionary trees were constructed; these placed the endosymbiont in the genus Devosia in the alpha-Proteobacteria. The validity of this finding was also shown by fluorescence in situ hybridization with a Devosia-specific oligonucleotide probe. Differences at the 16S rRNA gene level (which allowed the construction of a species-specific oligonucleotide probe) and the peculiar habitat indicate that the endosymbiont represents a novel species. As its cultivation has not been successful to date, the provisional name 'Candidatus Devosia euplotis' is proposed. The species- and group-specific probes designed in this study could represent convenient tools for the detection of 'Candidatus Devosia euplotis' and Devosia-like bacteria in the environment.}, }
@article {pmid15270538, year = {2003}, author = {Casiraghi, M and Werren, JH and Bazzocchi, C and Biserni, A and Bandi, C}, title = {dnaA gene sequences from Wolbachia pipientis support subdivision into supergroups and provide no evidence for recombination in the lineages infecting nematodes.}, journal = {Parassitologia}, volume = {45}, number = {1}, pages = {13-18}, pmid = {15270538}, issn = {0048-2951}, mesh = {Animals ; Bacterial Proteins/*genetics ; DNA, Bacterial/genetics ; DNA-Binding Proteins/*genetics ; Filarioidea/*microbiology ; Insecta/microbiology ; Phylogeny ; Recombination, Genetic ; Sequence Alignment ; Sequence Homology, Nucleic Acid ; Species Specificity ; Wolbachia/classification/*genetics ; }, abstract = {Wolbachia pipientis is an intracellular bacterial endosymbiont of arthropods and filarial nematodes. Six main supergroups of W. pipientis have been described: supergroups A, B, E, and F encompass arthropod wolbachiae; supergroups C and D encompass nematode wolbachiae. The description of these six supergroups has been based on the analysis of only two genes (ftsZ and 16S rDNA) and before decisions are taken on the taxonomic status of the six supergroups, analysis of further genes is required. In addition, the branching order of the six supergroups is still unresolved. Sequence information from other genes is also needed to allow phylogenesis to be addressed through the analysis of a higher number of characters. Here we report sequences from a portion of the gene coding for the DNAA protein of W pipientis, generated from the endosymbionts of 22 host species. Phylogenies based on dnaA gene sequences are congruent with the existence of at least six supergroups of W pipientis. In addition, subtrees generated for nematode wolbachiae in supergroups C and D were compared to the trees based on the already available gene sequences (ftsZ, 16S rDNA and wsp). The congruence observed among the trees based on the different genes agrees with the hypothesis that recombination does not occur in nematode wolbachiae.}, }
@article {pmid15267003, year = {2003}, author = {Sacchi, L and Corona, S and Kramer, L and Calvi, L and Casiraghi, M and Franceschi, A}, title = {Ultrastructural evidence of the degenerative events occurring during embryogenesis of the filarial nematode Brugia pahangi after tetracycline treatment.}, journal = {Parassitologia}, volume = {45}, number = {2}, pages = {89-96}, pmid = {15267003}, issn = {0048-2951}, mesh = {Animals ; Brugia pahangi/*embryology/microbiology/ultrastructure ; Embryo, Nonmammalian/drug effects/microbiology/ultrastructure ; Female ; Male ; Microscopy, Electron ; Oocytes/drug effects/microbiology ; Ovary/cytology/drug effects ; Symbiosis/drug effects ; Tetracycline/*pharmacology ; Vacuoles/ultrastructure ; Wolbachia/*drug effects/isolation &amp; purification ; }, abstract = {Intracellular bacteria belonging to the genus Wolbachia have been described in filarial nematodes and these microorganisms appear to have evolved an obligatory mutualistic association with their filarial hosts. In fact, antibiotic treatment leads to the clearance of bacteria from worms resulting in a block in embryogenesis and, eventually, death of adult filariae. Currently, the antifilarial action of antibiotic treatment is interpreted as a secondary consequence of the bacteriostatic activity against Wolbachia endosymbionts. Here, we demonstrate by transmission electron microscopy the degenerative events occurring during embryogenesis of Brugia pahangi after tetracycline treatment. After 56 days of treatment the cytoplasm of hypodermal cords was totally void of Wolbachia and numerous vacuoles, residual of cytolitic activity, were observed. In the ovary, the morphology of the oocytes was well conserved 33 days after treatment, but the texture of symbiotic bacteria appeared altered. After 56 days of treatment embryogenesis was dramatically affected and the terminal portion of the ovary appeared totally empty. The authors suggest that the symbiotic bacteria play a direct role in worm metabolism and a long-term bacteriostatic effect may block bacterial activity involved in the active control of cytolysis. As a consequence, the bacteriophorous vacuole is transformed into a digestive vacuole and the whole symbiotic population is disrupted.}, }
@article {pmid15265029, year = {2004}, author = {Minic, Z and Hervé, G}, title = {Biochemical and enzymological aspects of the symbiosis between the deep-sea tubeworm Riftia pachyptila and its bacterial endosymbiont.}, journal = {European journal of biochemistry}, volume = {271}, number = {15}, pages = {3093-3102}, doi = {10.1111/j.1432-1033.2004.04248.x}, pmid = {15265029}, issn = {0014-2956}, mesh = {Animals ; Annelida/*enzymology/metabolism/*microbiology ; Arginine/metabolism ; Carbon/metabolism ; Nitrogen/metabolism ; Pyrimidines/metabolism ; *Seawater ; *Symbiosis ; }, abstract = {Riftia pachyptila (Vestimentifera) is a giant tubeworm living around the volcanic deep-sea vents of the East Pacific Rise. This animal is devoid of a digestive tract and lives in an intimate symbiosis with a sulfur-oxidizing chemoautotrophic bacterium. This bacterial endosymbiont is localized in the cells of a richly vascularized organ of the worm: the trophosome. These organisms are adapted to their extreme environment and take advantage of the particular composition of the mixed volcanic and sea waters to extract and assimilate inorganic metabolites, especially carbon, nitrogen, oxygen and sulfur. The high molecular mass hemoglobin of the worm is the transporter for both oxygen and sulfide. This last compound is delivered to the bacterium which possesses the sulfur oxidizing respiratory system, which produces the metabolic energy for the two partners. CO2 is also delivered to the bacterium where it enters the Calvin-Benson cycle. Some of the resulting small carbonated organic molecules are thus provided to the worm for its own metabolism. As far as nitrogen assimilation is concerned, NH3 can be used by the two partners but nitrate can be used only by the bacterium. This very intimate symbiosis applies also to the organization of metabolic pathways such as those of pyrimidine nucleotides and arginine. In particular, the worm lacks the first three enzymes of the de novo pyrimidine biosynthetic pathways as well as some enzymes involved in the biosynthesis of polyamines. The bacterium lacks the enzymes of the pyrimidine salvage pathway. This symbiotic organization constitutes a very interesting system to study the molecular and metabolic basis of biological adaptation.}, }
@article {pmid15264554, year = {2003}, author = {Banaszak, AT and Ayala-Schiaffino, BN and Rodríguez-Román, A and Enríquez, S and Iglesias-Prieto, R}, title = {Response of Millepora alcicornis (Milleporina: Milleporidae) to two bleaching events at Puerto Morelos reef, Mexican Caribbean.}, journal = {Revista de biologia tropical}, volume = {51 Suppl 4}, number = {}, pages = {57-66}, pmid = {15264554}, issn = {0034-7744}, mesh = {Animals ; Anthozoa/*radiation effects ; Chlorophyll/analysis/*radiation effects ; *Environmental Monitoring ; Hot Temperature ; Mexico ; Photobleaching/*radiation effects ; Seasons ; Seawater ; *Ultraviolet Rays ; }, abstract = {Two naturally occurring colonies of Millepora alcicornis were monitored during 1997 and 1998, both years in which this species bleached in the Mexican Caribbean. One colony (HL) was naturally exposed to a high light environment and another nearby colony (LL) was exposed to 5.9 times lower light levels due to shadowing by a pier. For 10 days in August 1997, seawater temperatures in the surrounding reef lagoon rose up to 1.5 degrees C above the 6-year August average. The HL colony bleached to white during this period, whereas, the LL colony remained dark-brown colored. The HL colony recovered its normal dark-brown coloration (reversible bleaching) within several weeks, during which time the seawater temperatures returned to average. The following year, for 10 days, seawater temperatures rose up to 3 degrees C above the 7-year August average and both colonies bleached to white and neither colony recovered (irreversible bleaching). Both colonies were rapidly overgrown by algae and hydroids and, as of June 2003, no recovery has taken place. Prior to the 1997 bleaching, experiments using solar radiation showed that the quantum yield of photosystem II charge separation of branches from HL and LL colonies were affected for several hours by exposure to ultraviolet radiation (UVR, 280 to 400 nm), but recovered by the same evening, suggesting that UVR does not have long-term effects on photochemistry in M. alcicornis. In situ effective quantum yield of photosystem II charge separation (deltaF/Fm') measurements before the 1998 bleaching event indicate that both colonies were healthy in terms of the physiological status of their endosymbionts. During and after the 1998 bleaching event, both colonies showed a reduction in deltaF/Fm' and consequently an increase in excitation pressure on photosystem II. The data suggest that temperature is not the only factor that causes bleaching and that solar radiation may play an important role in coral bleaching.}, }
@article {pmid15262285, year = {2004}, author = {Tagu, D and Prunier-Leterme, N and Legeai, F and Gauthier, JP and Duclert, A and Sabater-Muñoz, B and Bonhomme, J and Simon, JC}, title = {Annotated expressed sequence tags for studies of the regulation of reproductive modes in aphids.}, journal = {Insect biochemistry and molecular biology}, volume = {34}, number = {8}, pages = {809-822}, doi = {10.1016/j.ibmb.2004.05.001}, pmid = {15262285}, issn = {0965-1748}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/*physiology ; Base Sequence ; Databases, Genetic ; *Expressed Sequence Tags ; Gene Expression Profiling/methods ; *Gene Expression Regulation, Developmental ; Gene Library ; Genes, Insect/*genetics ; Molecular Sequence Data ; Parthenogenesis/*genetics ; Reproduction/*genetics ; }, abstract = {The damaging effect of aphids to crops is largely determined by the spectacular rate of increase of populational expansion due to their parthenogenetic generations. Despite this, the molecular processes triggering the transition between the parthenogenetic and sexual phases between their annual life cycle have received little attention. Here, we describe a collection of genes from the cereal aphid Rhopalosiphum padi expressed during the switch from parthenogenetic to sexual reproduction. After cDNA cloning and sequencing, 726 expressed sequence tags (EST) were annotated. The R. padi EST collection contained a substantial number (139) of bacterial endosymbiont sequences. The majority of R. padi cDNAs encoded either unknown proteins (56%) or housekeeping polypeptides (38%). The large proportion of sequences without similarities in the databases is related to both their small size and their high GC content, corresponding probably to the presence of 5'-unstranslated regions. Fifteen genes involved in developmental and differentiation events were identified by similarity to known genes. Some of these may be useful candidates for markers of the early steps of sexual differentiation.}, }
@article {pmid15258248, year = {2004}, author = {Mackiewicz, P and Zakrzewska-Czerwinska, J and Zawilak, A and Dudek, MR and Cebrat, S}, title = {Where does bacterial replication start? Rules for predicting the oriC region.}, journal = {Nucleic acids research}, volume = {32}, number = {13}, pages = {3781-3791}, pmid = {15258248}, issn = {1362-4962}, mesh = {Bacteria/classification/*genetics ; Bacterial Proteins/metabolism ; Chromosomes, Bacterial ; DNA Replication ; DNA, Bacterial/analysis/chemistry ; DNA-Binding Proteins/metabolism ; Phylogeny ; Regulatory Sequences, Nucleic Acid ; *Replication Origin ; Sequence Analysis, DNA ; }, abstract = {Three methods, based on DNA asymmetry, the distribution of DnaA boxes and dnaA gene location, were applied to identify the putative replication origins in 120 chromosomes. The chromosomes were classified according to the agreement of these methods and the applicability of these methods was evaluated. DNA asymmetry is the most universal method of putative oriC identification in bacterial chromosomes, but it should be applied together with other methods to achieve better prediction. The three methods identify the same region as a putative origin in all Bacilli and Clostridia, many Actinobacteria and gamma Proteobacteria. The organization of clusters of DnaA boxes was analysed in detail. For 76 chromosomes, a DNA fragment containing multiple DnaA boxes was identified as a putative origin region. Most bacterial chromosomes exhibit an overrepresentation of DnaA boxes; many of them contain at least two clusters of DnaA boxes in the vicinity of the oriC region. The additional clusters of DnaA boxes are probably involved in controlling replication initiation. Surprisingly, the characteristic features of the initiation of replication, i.e. a cluster of DnaA boxes, a dnaA gene and a switch in asymmetry, were not found in some of the analysed chromosomes, particularly those of obligatory intracellular parasites or endosymbionts. This is presumably connected with many mechanisms disturbing DNA asymmetry, translocation or disappearance of the dnaA gene and decay of the Escherichia coli perfect DnaA box pattern.}, }
@article {pmid15254259, year = {2004}, author = {Bordenstein, SR and Wernegreen, JJ}, title = {Bacteriophage flux in endosymbionts (Wolbachia): infection frequency, lateral transfer, and recombination rates.}, journal = {Molecular biology and evolution}, volume = {21}, number = {10}, pages = {1981-1991}, doi = {10.1093/molbev/msh211}, pmid = {15254259}, issn = {0737-4038}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Bacteriophages/genetics/*physiology ; Base Sequence ; Evolution, Molecular ; Molecular Sequence Data ; Phylogeny ; *Recombination, Genetic ; *Transduction, Genetic ; Wolbachia/*virology ; }, abstract = {The highly specialized genomes of bacterial endosymbionts typically lack one of the major contributors of genomic flux in the free-living microbial world-bacteriophages. This study yields three results that show bacteriophages have, to the contrary, been influential in the genome evolution of the most prevalent bacterial endosymbiont of invertebrates, Wolbachia. First, we show that bacteriophage WO is more widespread in Wolbachia than previously recognized, occurring in at least 89% (35/39) of the sampled genomes. Second, we show through several phylogenetic approaches that bacteriophage WO underwent recent lateral transfers between Wolbachia bacteria that coinfect host cells in the dipteran Drosophila simulans and the hymenopteran Nasonia vitripennis. These two cases, along with a previous report in the lepidopteran Ephestia cautella, support a general mechanism for genetic exchange in endosymbionts--the "intracellular arena" hypothesis--in which genetic material moves horizontally between bacteria that coinfect the same intracellular environment. Third, we show recombination in this bacteriophage; in the region encoding a putative capsid protein, the recombination rate is faster than that of any known recombining genes in the endosymbiont genome. The combination of these three lines of genetic evidence indicates that this bacteriophage is a widespread source of genomic instability in the intracellular bacterium Wolbachia and potentially the invertebrate host. More generally, it is the first bacteriophage implicated in frequent lateral transfer between the genomes of bacterial endosymbionts. Gene transfer by bacteriophages could drive significant evolutionary change in the genomes of intracellular bacteria that are typically considered highly stable and prone to genomic degradation.}, }
@article {pmid15252981, year = {2004}, author = {Weeks, AR and Stouthamer, R}, title = {Increased fecundity associated with infection by a cytophaga-like intracellular bacterium in the predatory mite, Metaseiulus occidentalis.}, journal = {Proceedings. Biological sciences}, volume = {271 Suppl 4}, number = {Suppl 4}, pages = {S193-5}, pmid = {15252981}, issn = {0962-8452}, mesh = {Analysis of Variance ; Animals ; California ; Crosses, Genetic ; *Cytophaga ; Female ; Fertility/physiology ; Host-Parasite Interactions ; Male ; Mites/*microbiology/physiology ; Ovum/physiology ; Sex Ratio ; }, abstract = {The endosymbiont Wolbachia has gained widespread notoriety over the past decade because of its high infection frequency among arthropods, and the unique heterogeneity of the host reproductive effects that it has been implicated as causing to enhance its own spread. Recently, another endosymbiotic bacterium from the Cytophaga-Flavobacterium-Bacteroides phylum has been shown to be widespread among arthropods and manipulate its hosts' reproduction to enhance its own spread. We show that infection by this Cytophaga-like organism (CLO) in the predatory mite Metaseiulus occidentalis (Acari: Phytoseiidae) is associated with a significant increase in the fecundity of infected females. This adds to the growing list of phenotypes that the CLO can induce in its hosts, which now include feminization, parthenogenesis induction, cytoplasmic incompatibility and fecundity enhancement, rivalling Wolbachia for overall diversity of host reproductive manipulations.}, }
@article {pmid15245416, year = {2004}, author = {Fabricius, KE and Mieog, JC and Colin, PL and Idip, D and van Oppen, MJ}, title = {Identity and diversity of coral endosymbionts (zooxanthellae) from three Palauan reefs with contrasting bleaching, temperature and shading histories.}, journal = {Molecular ecology}, volume = {13}, number = {8}, pages = {2445-2458}, doi = {10.1111/j.1365-294X.2004.02230.x}, pmid = {15245416}, issn = {0962-1083}, mesh = {Acclimatization/*physiology ; Animals ; Anthozoa/*microbiology ; Base Sequence ; Bayes Theorem ; DNA, Ribosomal/genetics ; Dinoflagellida/*genetics/physiology ; Geography ; Molecular Sequence Data ; Pacific Ocean ; Palau ; *Phylogeny ; Polymorphism, Single-Stranded Conformational ; Sequence Analysis, DNA ; *Symbiosis ; *Temperature ; Video Recording ; }, abstract = {The potential of corals to associate with more temperature-tolerant strains of algae (zooxanthellae, Symbiodinium) can have important implications for the future of coral reefs in an era of global climate change. In this study, the genetic identity and diversity of zooxanthellae was investigated at three reefs with contrasting histories of bleaching mortality, water temperature and shading, in the Republic of Palau (Micronesia). Single-stranded conformation polymorphism and sequence analysis of the ribosomal DNA internal transcribed spacer (ITS)1 region was used for genotyping. A chronically warm but partly shaded coral reef in a marine lake that is hydrographically well connected to the surrounding waters harboured only two single-stranded conformation polymorphism profiles (i.e. zooxanthella communities). It consisted only of Symbiodinium D in all 13 nonporitid species and two Porites species investigated, with the remaining five Porites harbouring C*. Despite the high temperature in this lake (> 0.5 degrees above ambient), this reef did not suffer coral mortality during the (1998) bleaching event, however, no bleaching-sensitive coral families and genera occur in the coral community. This setting contrasts strongly with two other reefs with generally lower temperatures, in which 10 and 12 zooxanthella communities with moderate to low proportions of clade D zooxanthellae were found. The data indicate that whole coral assemblages, when growing in elevated seawater temperatures and at reduced irradiance, can be composed of colonies associated with the more thermo-tolerant clade D zooxanthellae. Future increases in seawater temperature might, therefore, result in an increasing prevalence of Symbiodinium phylotype D in scleractinian corals, possibly associated with a loss of diversity in both zooxanthellae and corals.}, }
@article {pmid15244853, year = {2004}, author = {Frean, MR and Abraham, ER}, title = {Adaptation and enslavement in endosymbiont-host associations.}, journal = {Physical review. E, Statistical, nonlinear, and soft matter physics}, volume = {69}, number = {5 Pt 1}, pages = {051913}, doi = {10.1103/PhysRevE.69.051913}, pmid = {15244853}, issn = {1539-3755}, mesh = {Animals ; Biological Evolution ; Ecology ; Evolution, Molecular ; Models, Biological ; Models, Statistical ; *Symbiosis ; Time Factors ; }, abstract = {The evolutionary persistence of symbiotic associations is a puzzle. Adaptation should eliminate cooperative traits if it is possible to enjoy the advantages of cooperation without reciprocating-a facet of cooperation known in game theory as the Prisoner's Dilemma. Despite this barrier, symbioses are widespread and may have been necessary for the evolution of complex life. The discovery of strategies such as tit-for-tat has been presented as a general solution to the problem of cooperation. However, this only holds for within-species cooperation, where a single strategy will come to dominate the population. In a symbiotic association each species may have a different strategy, and the theoretical analysis of the single-species problem is no guide to the outcome. We present basic analysis of two-species cooperation and show that a species with a fast adaptation rate is enslaved by a slowly evolving one. Paradoxically, the rapidly evolving species becomes highly cooperative, whereas the slowly evolving one gives little in return. This helps understand the occurrence of endosymbioses where the host benefits, but the symbionts appear to gain little from the association.}, }
@article {pmid15240294, year = {2004}, author = {Duplessis, MR and Ziebis, W and Gros, O and Caro, A and Robidart, J and Felbeck, H}, title = {Respiration strategies utilized by the gill endosymbiont from the host lucinid Codakia orbicularis (Bivalvia: Lucinidae).}, journal = {Applied and environmental microbiology}, volume = {70}, number = {7}, pages = {4144-4150}, pmid = {15240294}, issn = {0099-2240}, mesh = {Anaerobiosis ; Animals ; Bivalvia/*metabolism/*microbiology ; Gills/*microbiology ; Hemolymph/metabolism ; Nitrates/analysis ; Nitrites/analysis ; *Oxygen Consumption ; Sulfides/metabolism ; *Symbiosis ; }, abstract = {The large tropical lucinid clam Codakia orbicularis has a symbiotic relationship with intracellular, sulfide-oxidizing chemoautotrophic bacteria. The respiration strategies utilized by the symbiont were explored using integrative techniques on mechanically purified symbionts and intact clam-symbiont associations along with habitat analysis. Previous work on a related symbiont species found in the host lucinid Lucinoma aequizonata showed that the symbionts obligately used nitrate as an electron acceptor, even under oxygenated conditions. In contrast, the symbionts of C. orbicularis use oxygen as the primary electron acceptor while evidence for nitrate respiration was lacking. Direct measurements obtained by using microelectrodes in purified symbiont suspensions showed that the symbionts consumed oxygen; this intracellular respiration was confirmed by using the redox dye CTC (5-cyano-2,3-ditolyl tetrazolium chloride). In the few intact chemosymbioses tested in previous studies, hydrogen sulfide production was shown to occur when the animal-symbiont association was exposed to anoxia and elemental sulfur stored in the thioautotrophic symbionts was proposed to serve as an electron sink in the absence of oxygen and nitrate. However, this is the first study to show by direct measurements using sulfide microelectrodes in enriched symbiont suspensions that the symbionts are the actual source of sulfide under anoxic conditions.}, }
@article {pmid15239381, year = {2004}, author = {Corsaro, D and Venditti, D}, title = {Emerging chlamydial infections.}, journal = {Critical reviews in microbiology}, volume = {30}, number = {2}, pages = {75-106}, doi = {10.1080/10408410490435106}, pmid = {15239381}, issn = {1040-841X}, mesh = {Abortion, Spontaneous/etiology ; Animals ; Arthropods/microbiology ; Central Nervous System Diseases/microbiology ; *Chlamydia Infections/complications/diagnosis/transmission ; Chlamydiales/classification/*isolation &amp; purification/pathogenicity ; Disease Reservoirs ; Environmental Microbiology ; Eye Infections/microbiology ; Female Urogenital Diseases/complications/microbiology ; Fishes/microbiology ; Humans ; Male Urogenital Diseases ; Phylogeny ; RNA, Ribosomal, 16S/analysis/genetics ; Reptiles/microbiology ; Respiratory Tract Infections/microbiology/transmission ; Symbiosis ; }, abstract = {Chlamydiae are important intracellular bacterial pathogens of vertebrates. In the last years, novel members of this group have been discovered: Parachlamydia acanthamoebae and Simkania negevensis seems to be emerging respiratory human pathogens, while Waddlia chondrophila might be a new agent of bovine abortion. Various species have been showed to infect also the herpetofauna and fishes, and some novel chlamydiae are endosymbionts of arthropods. In addition, molecular studies evidenced a huge diversity of chlamydiae from both environmental and clinical samples, most of such a diversity could be formed by novel lineages of chlamydiae. Experimental studies showed that free-living amoebae may support multiplication of various chlamydiae, then could play an important role as reservoir/vector of chlamydial infections. Here we reviewed literature data concerning chlamydial infections, with a particular emphasis on the novely described chlamydial organisms.}, }
@article {pmid15218707, year = {2004}, author = {Stechmann, A and Cavalier-Smith, T}, title = {Evolutionary origins of Hsp90 chaperones and a deep paralogy in their bacterial ancestors.}, journal = {The Journal of eukaryotic microbiology}, volume = {51}, number = {3}, pages = {364-373}, doi = {10.1111/j.1550-7408.2004.tb00580.x}, pmid = {15218707}, issn = {1066-5234}, mesh = {Animals ; Bacteria/classification/*genetics ; Eukaryotic Cells/*metabolism ; *Evolution, Molecular ; HSP90 Heat-Shock Proteins/*genetics ; Phylogeny ; }, abstract = {The 82-90 kD family of molecular chaperone proteins has homologs in eukaryotes (Hsp90) and many eubacteria (HtpG) but not in Archaebacteria. We used representatives of all four different eukaryotic paralogs (cytosolic, endoplasmic reticulum (ER), chloroplast, mitochondrial) together with numerous eubacterial HtpG proteins for phylogenetic analyses to investigate their evolutionary origins. Our trees confirm that none of the organellar Hsp90s derives from the endosymbionts of early eukaryotes. Contrary to previous suggestions of distant origins through lateral gene transfer (LGT) all eukaryote Hsp90s are related to Gram-positive eubacterial HtpG proteins. The nucleocytosolic, ER and chloroplast Hsp90 paralogs are clearly mutually related. The origin of mitochondrial Hsp90 is more obscure, as these sequences are deeply nested within eubacteria. Our trees also reveal a deep split within eubacteria into a group of mainly long-branching sequences (including the eukaryote mitochondrial Hsp90s) and another group comprising exclusively short-branching HtpG proteins, from which the cytosolic/ER versions probably arose. Both versions are present in several eubacterial phyla, suggesting gene duplication very early in eubacterial evolution and multiple independent losses thereafter. We identified one probable case of LGT within eubacteria. However, multiple losses can simply explain the evolutionary pattern of the eubacterial HtpG paralogs and predominate over LGT. We suggest that the actinobacterial ancestor of eukaryotes harbored genes for both eubacterial HtpG paralogs, as the actinobacterium Streptomyces coelicolor still does; one could have given rise to the mitochondrial Hsp90 and the other, following another duplication event in the ancestral eukaryote, to the cytosolic and ER Hsp90 homologs.}, }
@article {pmid15214644, year = {2004}, author = {Zakhia, F and Jeder, H and Domergue, O and Willems, A and Cleyet-Marel, JC and Gillis, M and Dreyfus, B and de Lajudie, P}, title = {Characterisation of wild legume nodulating bacteria (LNB) in the infra-arid zone of Tunisia.}, journal = {Systematic and applied microbiology}, volume = {27}, number = {3}, pages = {380-395}, doi = {10.1078/0723-2020-00273}, pmid = {15214644}, issn = {0723-2020}, mesh = {Alphaproteobacteria/classification/genetics/*isolation &amp; purification/metabolism ; Bacterial Proteins/analysis/isolation &amp; purification ; Bradyrhizobium/classification/genetics/isolation &amp; purification/metabolism ; DNA Fingerprinting ; DNA, Bacterial/chemistry/isolation &amp; purification ; DNA, Ribosomal/analysis/chemistry/isolation &amp; purification ; DNA, Ribosomal Spacer/chemistry/isolation &amp; purification ; Electrophoresis, Polyacrylamide Gel ; Fabaceae/*microbiology ; Genes, rRNA ; Molecular Sequence Data ; Nitrogen Fixation ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Proteome/analysis/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Rhizobiaceae/*classification/genetics/*isolation &amp; purification/metabolism ; Rhizobium ; Sequence Analysis, DNA ; Sequence Homology ; Sinorhizobium ; Tunisia ; }, abstract = {We report on the isolation and the characterization of nitrogen-fixing root nodule bacteria isolated from natural legumes in a region of South Tunisia corresponding to the infra-arid climatic zone. A collection of 60 new bacterial root nodule isolates were obtained from 19 legume species belonging to the genera Acacia, Anthyllis, Argyrolobium, Astragalus, Calycotome, Coronilla, Ebenus, Genista, Hedysarum, Hippocrepis, Lathyrus, Lotus, Medicago, Ononis. The isolates were characterised by (1) comparative 16S ARDRA using 7 enzymes, (2) total cell protein SDS-PAGE analysis and (3) 16S rDNA sequencing. The results show that these isolates are diverse and belong to the genera Rhizobium, Sinorhizobium, Mesorhizobium and Bradyrhizobium. Bradyrhizobium were further characterised by 16S-23S rDNA IGS sequencing. Surprisingly strains nodulating Astragalus cruciatus, Lotus creticus and Anthyllis henoniana were identified as Rhizobium galegae, a species recorded only as endosymbiont of Galega officinalis and G. orientalis in northern regions so far.}, }
@article {pmid15210803, year = {2004}, author = {Brattig, NW and Bazzocchi, C and Kirschning, CJ and Reiling, N and Büttner, DW and Ceciliani, F and Geisinger, F and Hochrein, H and Ernst, M and Wagner, H and Bandi, C and Hoerauf, A}, title = {The major surface protein of Wolbachia endosymbionts in filarial nematodes elicits immune responses through TLR2 and TLR4.}, journal = {Journal of immunology (Baltimore, Md. : 1950)}, volume = {173}, number = {1}, pages = {437-445}, doi = {10.4049/jimmunol.173.1.437}, pmid = {15210803}, issn = {0022-1767}, mesh = {Adolescent ; Adult ; Animals ; Bacterial Proteins/*immunology ; Cytokines/biosynthesis ; Female ; Humans ; Lymphokines/biosynthesis ; Male ; Membrane Glycoproteins/*physiology ; Membrane Proteins/immunology ; Middle Aged ; Onchocerca volvulus/*microbiology ; Onchocerciasis/*immunology ; Receptors, Cell Surface/*physiology ; Symbiosis ; Toll-Like Receptor 2 ; Toll-Like Receptor 4 ; Toll-Like Receptors ; Wolbachia/*immunology ; }, abstract = {More than 150 million humans in tropical countries are infected by filarial nematodes which harbor intracellular bacterial endosymbionts of the genus Wolbachia (Rickettsiales). These bacteria have been implicated in adverse effects of drug treatment in filariasis. The present study provides evidence that purified major Wolbachia surface protein (rWSP) acts as an inducer of the innate immune system through TLR2 and TLR4: 1) recombinant, stringently purified rWSP elicited the release of TNF-alpha, IL-12, and IL-8 from cultured blood cells of both Onchocerca volvulus-infected and uninfected people; 2) the inflammatory response to rWSP challenge was TLR2- and TLR4-dependent as demonstrated with TLR-transfected fibroblastoid cells, as well as macrophages and dendritic cells from functional TLR-deficient mice; 3) blood cells of onchocerciasis patients exposed to rWSP also generated down-regulating mediators IL-10 and PGE(2) after 6 days of culture; 4) furthermore, rWSP-reactive IgG1 Abs were present in sera of O. volvulus-infected people but not in those of uninfected Europeans. The lack of rWSP-reactive IgE and IgG4 in serum indicated a bias toward a Th1-type adaptive immune response. Abs against rWSP stained endobacteria in living and degenerating adult O. volvulus filariae, tissue microfilariae and host tissue macrophages that apparently had engulfed microfilariae. Thus, filarial helminths, through products of their endobacteria such as WSP, acquire characteristics of a typical microbial pathogen inducing immune responses via TLR2 and TLR4.}, }
@article {pmid15205418, year = {2004}, author = {Cronan, GE and Keating, DH}, title = {Sinorhizobium meliloti sulfotransferase that modifies lipopolysaccharide.}, journal = {Journal of bacteriology}, volume = {186}, number = {13}, pages = {4168-4176}, pmid = {15205418}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Bacterial Proteins/genetics ; Lipopolysaccharides/*metabolism ; Molecular Sequence Data ; Open Reading Frames ; Sinorhizobium meliloti/*enzymology ; Sulfotransferases/genetics/*physiology ; Symbiosis ; }, abstract = {Sinorhizobium meliloti is a gram-negative soil bacterium found either in free-living form or as a nitrogen-fixing endosymbiont of a plant structure called the nodule. Symbiosis between S. meliloti and its plant host alfalfa is dependent on bacterial transcription of nod genes, which encode the enzymes responsible for synthesis of Nod factor. S. meliloti Nod factor is a lipochitooligosaccharide that undergoes a sulfate modification essential for its biological activity. Sulfate also modifies the carbohydrate substituents of the bacterial cell surface, including lipopolysaccharide (LPS) and capsular polysaccharide (K-antigen) (R. A. Cedergren, J. Lee, K. L. Ross, and R. I. Hollingsworth, Biochemistry 34:4467-4477, 1995). We utilized the genomic sequence of S. meliloti to identify an open reading frame, SMc04267 (which we now propose to name lpsS), which encodes an LPS sulfotransferase activity. We expressed LpsS in Escherichia coli and demonstrated that the purified protein functions as an LPS sulfotransferase. Mutants lacking LpsS displayed an 89% reduction in LPS sulfotransferase activity in vitro. However, lpsS mutants retain approximately wild-type levels of sulfated LPS when assayed in vivo, indicating the presence of an additional LPS sulfotransferase activity(ies) in S. meliloti that can compensate for the loss of LpsS. The lpsS mutant did show reduced LPS sulfation, compared to that of the wild type, under conditions that promote nod gene expression, and it elicited a greater number of nodules than did the wild type during symbiosis with alfalfa. These results suggest that sulfation of cell surface polysaccharides and Nod factor may compete for a limiting pool of intracellular sulfate and that LpsS is required for optimal LPS sulfation under these conditions.}, }
@article {pmid15185926, year = {2004}, author = {Scoles, GA}, title = {Phylogenetic analysis of the Francisella-like endosymbionts of Dermacentor ticks.}, journal = {Journal of medical entomology}, volume = {41}, number = {3}, pages = {277-286}, doi = {10.1603/0022-2585-41.3.277}, pmid = {15185926}, issn = {0022-2585}, mesh = {Animals ; Base Sequence ; Biological Evolution ; DNA/genetics ; DNA Primers ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; Dermacentor/*classification/*genetics/physiology ; Francisella tularensis/*classification/genetics/physiology ; Genome ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*physiology ; }, abstract = {Bacterial endosymbionts with significant homology to Francisella tularensis (gamma-proteobacteria) have been described from at least five species of ticks in three different genera, including two North American Dermacentor species [D. andersoni Stiles and D. variabilis (Say)]. The evolutionary relationships among the Francisella-like endosymbionts (FLE) from different hosts and between FLE and the arthropod-borne pathogen F. tularensis are not known. A 1,169-base fragment of the 16s rDNA and a 713-base fragment of the F. tularensis 17-kDa lipoprotein gene homolog of the FLE of six North American Dermacentor tick species [D. anderson, D. variabilis, D. albipictus (Packard), D. occidentalis Marx, D. hunteri Bishopp, and D. (Anocentor) nitens Neumann] and of Amblyomma maculatum Koch and Ornithodoros porcinus (Murry 1877, sensu Walton 1979) as outgroups, were subjected to phylogenetic analysis. These gene phylogenies were compared with a phylogeny of the same tick species constructed from a 435-base fragment of the tick mitochondrial 16s rDNA. Although the phylogenies of the FLE and their tick hosts are parallel at the genus level, the Dermacentor FLE are unresolved at the species level. The FLE and the Dermacentor ticks show little sign of co-speciation, possibly indicating that the association between these endosymbiont and the Dermacentor ticks is of a relatively recent origin. Several ticks were co-infected, either with two FLE with divergent 17-kDa lipoprotein gene sequences or with FLE and an unidentified species of spotted fever group rickettsia (alpha-proteobacteria). Infection with FLE does not seem to have precluded infection with either a second closely related gamma-proteobacterial symbiont or with a second less closely related alpha-proteobacterial symbiont.}, }
@article {pmid15184137, year = {2004}, author = {Thao, ML and Baumann, P}, title = {Evolutionary relationships of primary prokaryotic endosymbionts of whiteflies and their hosts.}, journal = {Applied and environmental microbiology}, volume = {70}, number = {6}, pages = {3401-3406}, pmid = {15184137}, issn = {0099-2240}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; DNA, Bacterial/analysis ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/analysis ; *Evolution, Molecular ; Hemiptera/classification/genetics/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are plant sap-sucking insects that harbor prokaryotic primary endosymbionts (P-endosymbionts) within specialized cells located in their body cavity. Four-kilobase DNA fragments containing 16S-23S ribosomal DNA (rDNA) were amplified from the P-endosymbiont of 24 whiteflies from 22 different species of 2 whitefly subfamilies. In addition, 3-kb DNA fragments containing mitochondrial cytB, nd1, and large-subunit rDNA (LrDNA) were amplified from 17 whitefly species. Comparisons of the P-endosymbiont (16S-23S rDNA) and host (cytB-nd1-LrDNA) phylogenetic trees indicated overall congruence consistent with a single infection of a whitefly ancestor with a bacterium and subsequent cospeciation (cocladogenesis) of the host and the P-endosymbiont. On the basis of both the P-endosymbiont and host trees, the whiteflies could be subdivided into at least five clusters. The major subdivision was between the subfamilies Aleyrodinae and Aleurodicinae. Unlike the P-endosymbionts of may other insects, the P-endosymbionts of whiteflies were related to Pseudomonas and possibly to the P-endosymbionts of psyllids. The lineage consisting of the P-endosymbionts of whiteflies is given the designation "Candidatus Portiera" gen. nov., with a single species, "Candidatus Portiera aleyrodidarum" sp. nov.}, }
@article {pmid15178799, year = {2004}, author = {Little, AF and van Oppen, MJ and Willis, BL}, title = {Flexibility in algal endosymbioses shapes growth in reef corals.}, journal = {Science (New York, N.Y.)}, volume = {304}, number = {5676}, pages = {1492-1494}, doi = {10.1126/science.1095733}, pmid = {15178799}, issn = {1095-9203}, mesh = {Adaptation, Physiological ; Animals ; Anthozoa/*growth &amp; development/physiology ; Dinoflagellida/genetics/*physiology ; Ecosystem ; Environment ; Eukaryota ; Genome, Protozoan ; Larva/growth &amp; development ; Polymorphism, Single-Stranded Conformational ; *Symbiosis ; }, abstract = {The relation between corals and their algal endosymbionts has been a key to the success of scleractinian (stony) corals as modern reef-builders, but little is known about early stages in the establishment of the symbiosis. Here, we show that initial uptake of zooxanthellae by juvenile corals during natural infection is nonspecific (a potentially adaptive trait); the association is flexible and characterized by a change in (dominant) zooxanthella strains over time; and growth rates of experimentally infected coral holobionts are partly contingent on the zooxanthella strain harbored, with clade C-infected juveniles growing two to three times as fast as those infected with clade D.}, }
@article {pmid15165057, year = {2004}, author = {Podlipaev, S and Votýpka, J and Jirků, M and Svobodová, M and Lukes, J}, title = {Herpetomonas ztiplika n. sp. (Kinetoplastida: Trypanosomatidae): a parasite of the blood-sucking biting midge Culicoides kibunensis Tokunaga, 1937 (Diptera: Ceratopogonidae).}, journal = {The Journal of parasitology}, volume = {90}, number = {2}, pages = {342-347}, doi = {10.1645/GE-156R}, pmid = {15165057}, issn = {0022-3395}, mesh = {Animals ; Base Sequence ; Ceratopogonidae/*parasitology ; DNA, Kinetoplast/chemistry ; DNA, Protozoan/chemistry ; Female ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; RNA, Ribosomal, 5S/genetics ; Trypanosomatina/*classification/genetics/ultrastructure ; }, abstract = {Herein, we describe the first case of a natural infection of biting midges by a kinetoplastid protozoan. Flagellates from a female Culicoides kibunensis captured in a bird's nest were introduced into culture and characterized by light and electron microscopy. However, because the morphological data were inconclusive, the novel endosymbiont-free trypanosomatid was assigned into Herpetomonas primarily on the basis of the 18S and 5S ribosomal RNA (rRNA) gene sequences.}, }
@article {pmid15157232, year = {2004}, author = {Dutton, TJ and Sinkins, SP}, title = {Strain-specific quantification of Wolbachia density in Aedes albopictus and effects of larval rearing conditions.}, journal = {Insect molecular biology}, volume = {13}, number = {3}, pages = {317-322}, doi = {10.1111/j.0962-1075.2004.00490.x}, pmid = {15157232}, issn = {0962-1075}, mesh = {Aedes/*microbiology ; Animals ; Bacterial Outer Membrane Proteins/genetics ; Body Weights and Measures ; DNA Primers ; Electrophoresis, Agar Gel ; Fluorometry ; Larva/microbiology/physiology ; Polymerase Chain Reaction ; Population Density ; Population Dynamics ; Reproduction/genetics ; *Symbiosis ; Wolbachia/*genetics/physiology ; }, abstract = {The density of the endosymbiont Wolbachia can influence the expression of the crossing sterilities known as cytoplasmic incompatibility (CI), and also its rate of maternal transmission. Aedes albopictus mosquitoes contain a superinfection with the Wolbachia strains wAlbA and wAlbB. A strain-specific real-time quantitative PCR assay was developed and used to quantify relative Wolbachia strain densities within individual mosquitoes. The wAlbB strain was consistently found to be at higher density than wAlbA, which can explain a slightly lower rate of maternal transmission reported for wAlbA. The effects of larval crowding and nutritional stress were also examined. Larval crowding always reduced adult size, but reduced the density of Wolbachia strains relative to uncrowded conditions only if crowding was accompanied by restricted nutrient availability. Crowded rearing conditions never resulted in strain segregation or in a reduction in the penetrance of CI, however. The rate of maternal transmission and the penetrance of CI are the two most important variables that determine relative Wolbachia population invasion dynamics, and both are considerably higher here than have been reported in the Drosophila simulans model system.}, }
@article {pmid15145251, year = {2004}, author = {Montenegro, H and Klaczko, LB}, title = {Low temperature cure of a male killing agent in Drosophila melanogaster.}, journal = {Journal of invertebrate pathology}, volume = {86}, number = {1-2}, pages = {50-51}, doi = {10.1016/j.jip.2004.03.004}, pmid = {15145251}, issn = {0022-2011}, mesh = {Animals ; *Cold Temperature ; Cytoplasm/physiology ; Drosophila melanogaster/*parasitology ; Environment ; Female ; Male ; Parasites/*pathogenicity ; Sex Ratio ; }, abstract = {Environmental factors can affect transmission or phenotype expression of selfish cytoplasmic endosymbionts such as embryonic male killers. Temperature is one factor that usually affects the transmission rate of selfish cytoplasmic endosymbionts. Heat cures have been described for several host-parasite systems, cold cures, however, are rare. We report a temperature cure of the Drosophila melanogaster male-killing agent, which occurs when flies are raised at 16.5 degrees C. Flies grown at 20, 24, and 28 degrees C maintained an extremely female biased sexual proportion.}, }
@article {pmid15144059, year = {2004}, author = {Bachvaroff, TR and Concepcion, GT and Rogers, CR and Herman, EM and Delwiche, CF}, title = {Dinoflagellate expressed sequence tag data indicate massive transfer of chloroplast genes to the nuclear genome.}, journal = {Protist}, volume = {155}, number = {1}, pages = {65-78}, doi = {10.1078/1434461000165}, pmid = {15144059}, issn = {1434-4610}, mesh = {Animals ; Cell Nucleus/*genetics ; Chloroplasts/*genetics ; DNA, Complementary/chemistry/isolation &amp; purification ; DNA, Protozoan/chemistry/isolation &amp; purification ; Dinoflagellida/*genetics ; Evolution, Molecular ; *Expressed Sequence Tags ; Gene Library ; *Genes, Protozoan ; Genomics ; Molecular Sequence Data ; Recombination, Genetic ; Sequence Analysis, DNA ; }, abstract = {The peridinin-pigmented plastids of dinoflagellates are very poorly understood, in part because of the paucity of molecular data available from these endosymbiotic organelles. To identify additional gene sequences that would carry information about the biology of the peridinin-type dinoflagellate plastid and its evolutionary history, an analysis was undertaken of arbitrarily selected sequences from cDNA libraries constructed from Lingulodinium polyedrum (1012 non-redundant sequences) and Amphidinium carterae (2143). Among the two libraries 118 unique plastid-associated sequences were identified, including 30 (most from A. carterae) that are encoded in the plastid genome of the red alga Porphyra. These sequences probably represent bona fide nuclear genes, and suggest that there has been massive transfer of genes from the plastid to the nuclear genome in dinoflagellates. These data support the hypothesis that the peridinin-type plastid has a minimal genome, and provide data that contradict the hypothesis that there is an unidentified canonical genome in the peridinin-type plastid. Sequences were also identified that were probably transferred directly from the nuclear genome of the red algal endosymbiont, as well as others that are distinctive to the Alveolata. A preliminary report of these data was presented at the Botany 2002 meeting in Madison, WI.}, }
@article {pmid15140268, year = {2004}, author = {Perotti, MA and Catalá, SS and Ormeño, Adel V and Zelazowska, M and Biliński, SM and Braig, HR}, title = {The sex ratio distortion in the human head louse is conserved over time.}, journal = {BMC genetics}, volume = {5}, number = {}, pages = {10}, pmid = {15140268}, issn = {1471-2156}, mesh = {Africa/epidemiology ; Animals ; Anoplura/microbiology ; Argentina/epidemiology ; Asia/epidemiology ; Australia/epidemiology ; Child ; Female ; Humans ; Israel/epidemiology ; Lice Infestations/*epidemiology/parasitology/veterinary ; Male ; Molecular Sequence Data ; North America/epidemiology ; Pediculus/microbiology/*physiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rural Population ; Schools ; *Sex Ratio ; Species Specificity ; Swine Diseases/parasitology ; Time Factors ; United Kingdom/epidemiology ; Urban Population ; Wolbachia/genetics/isolation &amp; purification ; }, abstract = {BACKGROUND: At the turn of the 19th century the first observations of a female-biased sex ratio in broods and populations of the head louse, Pediculus humanus capitis, had been reported. A study by Buxton in 1940 on the sex ratio of lice on prisoners in Ceylon is still today the subject of reanalyses. This sex ratio distortion had been detected in ten different countries. In the last sixty years no new data have been collected, especially on scalp infestations under economically and socially more developed conditions.<br><br>RESULTS: Here we report a female bias of head lice in a survey of 480 school children in Argentina. This bias is independent of the intensity of the pediculosis, which makes local mate competition highly unlikely as the source of the aberrant sex ratio; however, other possible adaptive mechanisms cannot be discounted. These lice as well as lice from pupils in Britain were carrying several strains of the endosymbiotic bacterium Wolbachia pipientis, one of the most wide spread intracellular sex ratio distorters. Similar Wolbachia strains are also present in the pig louse, Haematopinus suis, suggesting that this endosymbiont might have a marked influence on the biology of the whole order. The presence of a related obligate nutritional bacterium in lice prevents the investigation of a causal link between sex ratio and endosymbionts.<br><br>CONCLUSIONS: Regardless of its origin, this sex ratio distortion in head lice that has been reported world wide, is stable over time and is a remarkable deviation from the stability of frequency-dependent selection of Fisher's sex ratio. A female bias first reported in 1898 is still present over a hundred years and a thousand generations later.}, }
@article {pmid15133087, year = {2004}, author = {León-Avila, G and Tovar, J}, title = {Mitosomes of Entamoeba histolytica are abundant mitochondrion-related remnant organelles that lack a detectable organellar genome.}, journal = {Microbiology (Reading, England)}, volume = {150}, number = {Pt 5}, pages = {1245-1250}, doi = {10.1099/mic.0.26923-0}, pmid = {15133087}, issn = {1350-0872}, mesh = {Animals ; Chaperonin 60/metabolism ; DNA, Kinetoplast/analysis ; DNA, Protozoan/*analysis ; Entamoeba histolytica/*chemistry/growth &amp; development/*ultrastructure ; Genome ; Mice ; Microscopy, Confocal ; Microscopy, Fluorescence ; Mitochondria/*ultrastructure ; Organelles/*genetics/metabolism/*ultrastructure ; }, abstract = {The existence of mitochondrion-related relict organelles (mitosomes) in the amitochondrial human pathogen Entamoeba histolytica and the detection of extranuclear DNA-containing cytoplasmic structures (EhKOs) has led to the suggestion that a remnant genome from the original mitochondrial endosymbiont might have been retained in this organism. This study reports on the mutually exclusive distribution of Cpn60 and extranuclear DNA in E. histolytica and on the distribution of Cpn60-containing mitosomes in this parasite. In situ nick-translation coupled to immunofluorescence microscopy failed to detect the presence of DNA in mitosomes, either in fixed parasite trophozoites or in partially purified organellar fractions. These results indicate that a remnant organellar genome has not been retained in E. histolytica mitosomes and demonstrate unequivocally that EhKOs and mitosomes are distinct and unrelated cellular structures.}, }
@article {pmid15132173, year = {2003}, author = {Hori, M and Fujishima, M}, title = {The endosymbiotic bacterium Holospora obtusa enhances heat-shock gene expression of the host Paramecium caudatum.}, journal = {The Journal of eukaryotic microbiology}, volume = {50}, number = {4}, pages = {293-298}, doi = {10.1111/j.1550-7408.2003.tb00137.x}, pmid = {15132173}, issn = {1066-5234}, mesh = {Amino Acid Sequence ; Animals ; Chaperonin 60/*biosynthesis/genetics ; *Gene Expression ; HSP70 Heat-Shock Proteins/biosynthesis/genetics ; Heat-Shock Response ; Holosporaceae/*physiology ; Molecular Sequence Data ; Paramecium/*microbiology ; Symbiosis/*physiology ; }, abstract = {The bacterium Holospora obtusa is a macronuclear-specific symbiont of the ciliate Paramecium caudatum. H. obtusa-bearing paramecia could survive even after the cells were quickly heated from 25 degrees C to 35 degrees C. To determine whether infection with H. obtusa confers heat shock resistance on its host, we isolated genes homologous to the heat shock protein genes hsp60 and hsp70 from P. caudatum. The deduced amino acid sequences of both cDNAs were highly homologous to hsp family sequences from other eukaryotes. Competitive PCR showed that H. obtusa-free paramecia expressed only trace amounts of hsp60 and hsp70 mRNA at 25 degrees C, but that expression of hsp70 was enhanced immediately after the cells were transferred to 35 degrees C. H. obtusa-bearing paramecia expressed high levels of hsp7O mRNA even at 25 degrees C and the level was further enhanced when the cells were incubated at 35 degrees C. In contrast, the expression pattern of hsp60 mRNA was the same in H. obtusa-bearing as in H. obtusa-free paramecia. These results indicate that infection with its endosymbiont can confer a heat-shock resistant nature on its host cells.}, }
@article {pmid15128570, year = {2004}, author = {Goffredi, SK and Warén, A and Orphan, VJ and Van Dover, CL and Vrijenhoek, RC}, title = {Novel forms of structural integration between microbes and a hydrothermal vent gastropod from the Indian Ocean.}, journal = {Applied and environmental microbiology}, volume = {70}, number = {5}, pages = {3082-3090}, pmid = {15128570}, issn = {0099-2240}, mesh = {Animals ; Esophagus/microbiology ; Indian Ocean ; Iron/metabolism ; Molecular Sequence Data ; Phylogeny ; Proteobacteria/classification/genetics/*growth &amp; development/metabolism ; RNA, Ribosomal, 16S ; Seawater/*microbiology ; Sequence Analysis, DNA ; Snails/*anatomy &amp; histology/*microbiology ; Sulfides/metabolism ; *Symbiosis ; }, abstract = {Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of gamma-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the snail tissues, and the presence of internal bacteria suggest a dependence on chemoautotrophy for nutrition. Most notably, this snail is unique in having a dense coat of mineralized scales covering the sides of its foot, a feature seen in no other living metazoan. The scales are coated with iron sulfides (pyrite and greigite) and heavily colonized by epsilon- and delta-proteobacteria, likely participating in mineralization of the sclerites. This novel metazoan-microbial collaboration illustrates the great potential of organismal adaptation in chemically and physically challenging deep-sea environments.}, }
@article {pmid15128464, year = {2004}, author = {Dighe, AS and Jangid, K and González, JM and Pidiyar, VJ and Patole, MS and Ranade, DR and Shouche, YS}, title = {Comparison of 16S rRNA gene sequences of genus Methanobrevibacter.}, journal = {BMC microbiology}, volume = {4}, number = {}, pages = {20}, pmid = {15128464}, issn = {1471-2180}, mesh = {Animals ; Base Sequence ; Ciliophora/microbiology ; *Genes, Archaeal ; *Genes, rRNA ; Methanobrevibacter/*classification/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/*classification/genetics ; Sequence Alignment ; }, abstract = {BACKGROUND: The phylogeny of the genus Methanobrevibacter was established almost 25 years ago on the basis of the similarities of the 16S rRNA oligonucleotide catalogs. Since then, many 16S rRNA gene sequences of newly isolated strains or clones representing the genus Methanobrevibacter have been deposited. We tried to reorganize the 16S rRNA gene sequences of this genus and revise the taxonomic affiliation of the isolates and clones representing the genus Methanobrevibacter.<br><br>RESULTS: The phylogenetic analysis of the genus based on 786 bp aligned region from fifty-four representative sequences of the 120 available sequences for the genus revealed seven multi-member groups namely, Ruminantium, Smithii, Woesei, Curvatus, Arboriphilicus, Filiformis, and the Termite gut symbionts along with three separate lineages represented by Mbr. wolinii, Mbr. acididurans, and termite gut flagellate symbiont LHD12. The cophenetic correlation coefficient, a test for the ultrametric properties of the 16S rRNA gene sequences used for the tree was found to be 0.913 indicating the high degree of goodness of fit of the tree topology. A significant relationship was found between the 16S rRNA sequence similarity (S) and the extent of DNA hybridization (D) for the genus with the correlation coefficient (r) for logD and logS, and for [ln(-lnD) and ln(-lnS)] being 0.73 and 0.796 respectively. Our analysis revealed that for this genus, when S = 0.984, D would be <70% at least 99% of the times, and with 70% D as the species "cutoff", any 16S rRNA gene sequence showing <98% sequence similarity can be considered as a separate species. In addition, we deduced group specific signature positions that have remained conserved in evolution of the genus.<br><br>CONCLUSIONS: A very significant relationship between D and S was found to exist for the genus Methanobrevibacter, implying that it is possible to predict D from S with a known precision for the genus. We propose to include the termite gut flagellate symbiont LHD12, the methanogenic endosymbionts of the ciliate Nyctotherus ovalis, and rat feces isolate RT reported earlier, as separate species of the genus Methanobrevibacter.}, }
@article {pmid15126491, year = {2004}, author = {Daugherty, RM and Linka, N and Audia, JP and Urbany, C and Neuhaus, HE and Winkler, HH}, title = {The nucleotide transporter of Caedibacter caryophilus exhibits an extended substrate spectrum compared to the analogous ATP/ADP translocase of Rickettsia prowazekii.}, journal = {Journal of bacteriology}, volume = {186}, number = {10}, pages = {3262-3265}, pmid = {15126491}, issn = {0021-9193}, support = {R01 AI015035/AI/NIAID NIH HHS/United States ; AI-15035/AI/NIAID NIH HHS/United States ; }, mesh = {Adenosine Triphosphate/*metabolism ; Alphaproteobacteria/*metabolism ; Deoxyadenine Nucleotides/*metabolism ; Mitochondrial ADP, ATP Translocases/*metabolism ; Nucleotide Transport Proteins/*metabolism ; Rickettsia prowazekii/*metabolism ; Substrate Specificity ; }, abstract = {The two obligate intracellular alphaproteobacteria Rickettsia prowazekii and Caedibacter caryophilus, a human pathogen and a paramecium endosymbiont, respectively, possess transport systems to facilitate ATP uptake from the host cell cytosol. These transport proteins, which have 65% identity at the amino acid level, were heterologously expressed in Escherichia coli, and their properties were compared. The results presented here demonstrate that the caedibacter transporter had a broader substrate than the more selective rickettsial transporter. ATP analogs with modified sugar moieties, dATP and ddATP, inhibited the transport of ATP by the caedibacter transporter but not by the rickettsial transporter. Both transporters were specific for di- and trinucleotides with an adenine base in that adenosine tetraphosphate, AMP, UTP, CTP, and GTP were not competitive inhibitors. Furthermore, the antiporter nature of both transport systems was shown by the dependence of the efflux of [alpha-32P]ATP on the influx of substrate (ATP but not dATP for rickettsiae, ATP or dATP for caedibacter).}, }
@article {pmid15119438, year = {2004}, author = {Abbot, P and Withgott, JH}, title = {Phylogenetic and molecular evidence for allochronic speciation in gall-forming aphids (Pemphigus).}, journal = {Evolution; international journal of organic evolution}, volume = {58}, number = {3}, pages = {539-553}, pmid = {15119438}, issn = {0014-3820}, mesh = {Animals ; Aphids/*genetics/*growth &amp; development/physiology ; Base Sequence ; Geography ; Haplotypes/genetics ; Life Cycle Stages/*physiology ; Molecular Sequence Data ; *Phylogeny ; Population Dynamics ; Populus ; Reproduction/physiology ; Sequence Analysis, DNA ; Species Specificity ; Time Factors ; United States ; }, abstract = {Sympatric populations can diverge when variation in phenology or life cycle causes them to mate at distinctly different times. We report patterns consistent with this process (allochronic speciation) in North American gall-forming aphids, in the absence of a host or habitat shift. Pemphigus populi-transversus Riley and P. obesinymphae Aoki form a monophyletic clade within the North American Pemphigus group. They are sympatric on the eastern cottonwood, Populus deltoides (Salicaceae), but have distinctly different life cycles, with sexual stages offset by approximately six months. Field evidence indicates that intermediate phenotypes do not commonly occur, and mitochondrial and bacterial endosymbiont DNA sequences show no maternal gene flow between the two species. Because a genetically distinct population of P. obesinymphae occurs in the southwestern United States on Populus fremontii, we consider the possibility of an initial allopatric phase in the divergence. We discuss the likely origins of the host use patterns in P. obesinymphae, and the larger sequence of evolutionary changes that likely led to the sympatric divergence of P. populi-transversus and P. obesinymphae. A plausible interpretation at this stage of investigation is that a shift in timing of the life cycle in an ancestral population, correlated with an underlying phenological complexity in its host plant, spurred divergence between the incipient species.}, }
@article {pmid15114416, year = {2004}, author = {Rogers, M and Keeling, PJ}, title = {Lateral transfer and recompartmentalization of Calvin cycle enzymes of plants and algae.}, journal = {Journal of molecular evolution}, volume = {58}, number = {4}, pages = {367-375}, pmid = {15114416}, issn = {0022-2844}, mesh = {Eukaryota/*enzymology/genetics ; Fructose-Bisphosphatase/genetics ; Fructose-Bisphosphate Aldolase/genetics ; *Gene Transfer, Horizontal ; Phosphoric Monoester Hydrolases/genetics ; Plants/*enzymology/genetics ; }, abstract = {Certain Calvin cycle enzymes also function in glycolysis or gluconeogenisis, thus photosynthetic eukaryotes would be predicted to have ancestrally possessed cytosolic homologues of these enzymes derived from the eukaryotic host and plastid homologues from the cyanobacterial endosymbiont. In practice, the evolutionary histories of these enzymes are often more complex. Focusing on eukaryotes with secondary plastids, we have examined the evolution of four such genes: class I and II fructose bisphosphate aldolase (FBA), sedoheptulose bisphosphatase (SBPase), and fructose bisphosphatase (FBPase). We show that previously observed distributions of plastid and cytosolic homologues are not always found in algae with secondary plastids: there is evidence for multiple events of both lateral gene transfer and retargeting to a new cellular compartment for both cytosolic and plastid enzymes of plants and algae. In particular, we show that a clade of class II FBAs spans a greater diversity of eukaryotes that previously recognized and contains both plastid-targeted (Phaeodactylum, Odontella) and cytosolic (ascomycetes, oomycetes, Euglena, and Bigelowiella) forms. Lateral transfer events also gave rise to a subset of plant cytosolic FBA, as well as cytosolic FBPase in Toxoplasma and other coccidian apicomplexa. In contrast, it has recently been suggested that the Trypanosoma FBA and SBPase are derived from a plastid, however, greater taxonomic sampling shows that these enzymes provide no evidence for a plastid-containing ancestor of Trypanosoma. Altogether, the evolutionary histories of the FBA and SBPase/FBPase gene families are complex, including extensive paralogy, lateral transfer, and retargeting between cellular compartments.}, }
@article {pmid15112236, year = {2004}, author = {Bazinet, C}, title = {Endosymbiotic origins of sex.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {26}, number = {5}, pages = {558-566}, doi = {10.1002/bies.20023}, pmid = {15112236}, issn = {0265-9247}, support = {HD36498-01/HD/NICHD NIH HHS/United States ; }, mesh = {Animals ; Biological Evolution ; Gene Transfer, Horizontal ; Germ Cells/physiology ; Mitochondria/metabolism ; *Reproduction ; Reproduction, Asexual ; Sperm Motility ; Spermatogenesis/physiology ; *Symbiosis ; }, abstract = {Understanding how complex sexual reproduction arose, and why sexual organisms have been more successful than otherwise similar asexual organisms, is a longstanding problem in evolutionary biology. Within this problem, the potential role of endosymbionts or intracellular pathogens in mediating primitive genetic transfers is a continuing theme. In recent years, several remarkable activities of mitochondria have been observed in the germline cells of complex eukaryotes, and it has been found that bacterial endosymbionts related to mitochondria are capable of manipulating diverse aspects of metazoan gametogenesis. An attempt is made here to rationalize these observations with an endosymbiotic model for the evolutionary origins of sex. It is hypothesized that the contemporary life cycle of germline cells has descended from the life cycle of the endosymbiotic ancestor of the mitochondrion. Through an actin-based motility that drove it from one cell to another, the rickettsial ancestor of mitochondria may have functioned as a primitive transducing particle, the evolutionary progenitor of sperm.}, }
@article {pmid15111095, year = {2004}, author = {Foster, JM and Kumar, S and Ganatra, MB and Kamal, IH and Ware, J and Ingram, J and Pope-Chappell, J and Guiliano, D and Whitton, C and Daub, J and Blaxter, ML and Slatko, BE}, title = {Construction of bacterial artificial chromosome libraries from the parasitic nematode Brugia malayi and physical mapping of the genome of its Wolbachia endosymbiont.}, journal = {International journal for parasitology}, volume = {34}, number = {6}, pages = {733-746}, doi = {10.1016/j.ijpara.2004.02.001}, pmid = {15111095}, issn = {0020-7519}, mesh = {Animals ; Base Sequence ; Brugia malayi/*genetics ; Chromosome Mapping/*methods ; Chromosomes, Artificial, Bacterial/*genetics ; Contig Mapping/methods ; DNA, Bacterial/genetics ; DNA, Protozoan/genetics ; Genome, Bacterial ; Genome, Protozoan ; Genomic Library ; Molecular Weight ; Plasmids ; RNA, Bacterial/genetics ; RNA, Ribosomal/genetics ; Restriction Mapping/methods ; Sequence Analysis, DNA/methods ; Symbiosis/genetics ; Wolbachia/*genetics ; }, abstract = {The parasitic nematode, Brugia malayi, causes lymphatic filariasis in humans, which in severe cases leads to the condition known as elephantiasis. The parasite contains an endosymbiotic alpha-proteobacterium of the genus Wolbachia that is required for normal worm development and fecundity and is also implicated in the pathology associated with infections by these filarial nematodes. Bacterial artificial chromosome libraries were constructed from B. malayi DNA and provide over 11-fold coverage of the nematode genome. Wolbachia genomic fragments were simultaneously cloned into the libraries giving over 5-fold coverage of the 1.1 Mb bacterial genome. A physical framework for the Wolbachia genome was developed by construction of a plasmid library enriched for Wolbachia DNA as a source of sequences to hybridise to high-density bacterial artificial chromosome colony filters. Bacterial artificial chromosome end sequencing provided additional Wolbachia probe sequences to facilitate assembly of a contig that spanned the entire genome. The Wolbachia sequences provided a marker approximately every 10 kb. Four rare-cutting restriction endonucleases were used to restriction map the genome to a resolution of approximately 60 kb and demonstrate concordance between the bacterial artificial chromosome clones and native Wolbachia genomic DNA. Comparison of Wolbachia sequences to public databases using BLAST algorithms under stringent conditions allowed confident prediction of 69 Wolbachia peptide functions and two rRNA genes. Comparison to closely related complete genomes revealed that while most sequences had orthologs in the genome of the Wolbachia endosymbiont from Drosophila melanogaster, there was no evidence for long-range synteny. Rather, there were a few cases of short-range conservation of gene order extending over regions of less than 10 kb. The molecular scaffold produced for the genome of the Wolbachia from B. malayi forms the basis of a genomic sequencing effort for this bacterium, circumventing the difficult challenge of purifying sufficient endosymbiont DNA from a tropical parasite for a whole genome shotgun sequencing strategy.}, }
@article {pmid15094394, year = {2004}, author = {Fujii, Y and Kubo, T and Ishikawa, H and Sasaki, T}, title = {Isolation and characterization of the bacteriophage WO from Wolbachia, an arthropod endosymbiont.}, journal = {Biochemical and biophysical research communications}, volume = {317}, number = {4}, pages = {1183-1188}, doi = {10.1016/j.bbrc.2004.03.164}, pmid = {15094394}, issn = {0006-291X}, mesh = {Animals ; Bacteriophages/genetics/*isolation &amp; purification/ultrastructure ; DNA/isolation &amp; purification ; Electrophoresis, Agar Gel ; Genome, Bacterial ; Lysogeny ; Microscopy, Electron ; Moths/*microbiology ; Open Reading Frames ; Symbiosis ; Viral Proteins/genetics ; Wolbachia/genetics/physiology/*virology ; }, abstract = {Wolbachia is a group of obligate symbiotic bacteria found in many insects and other arthropods. The presence of Wolbachia alters reproduction in the host, but the mechanisms are unknown. Molecular biological studies of Wolbachia have delayed significantly, and one of the reasons is the lack of transformation techniques of this bacterium. In the present study, bacteriophage particles were isolated from Wolbachia for the first time. The purified phage had an isometric head that was approximately 40 nm in diameter and contained linear double-stranded DNA of approximately 20 kbp. Partial sequence information (total of 20,484 bp) revealed that there were 24 open reading frames including a structural gene module, and genes for replication and lysogenic conversion. This bacteriophage is the only known mobile genetic element potentially used for transformation of Wolbachia.}, }
@article {pmid15084508, year = {2004}, author = {Greub, G and Raoult, D}, title = {Microorganisms resistant to free-living amoebae.}, journal = {Clinical microbiology reviews}, volume = {17}, number = {2}, pages = {413-433}, pmid = {15084508}, issn = {0893-8512}, mesh = {Amoeba/growth &amp; development/*microbiology/virology ; Animals ; Bacteria/*classification/*growth &amp; development ; Coculture Techniques ; }, abstract = {Free-living amoebae feed on bacteria, fungi, and algae. However, some microorganisms have evolved to become resistant to these protists. These amoeba-resistant microorganisms include established pathogens, such as Cryptococcus neoformans, Legionella spp., Chlamydophila pneumoniae, Mycobacterium avium, Listeria monocytogenes, Pseudomonas aeruginosa, and Francisella tularensis, and emerging pathogens, such as Bosea spp., Simkania negevensis, Parachlamydia acanthamoebae, and Legionella-like amoebal pathogens. Some of these amoeba-resistant bacteria (ARB) are lytic for their amoebal host, while others are considered endosymbionts, since a stable host-parasite ratio is maintained. Free-living amoebae represent an important reservoir of ARB and may, while encysted, protect the internalized bacteria from chlorine and other biocides. Free-living amoebae may act as a Trojan horse, bringing hidden ARB within the human "Troy," and may produce vesicles filled with ARB, increasing their transmission potential. Free-living amoebae may also play a role in the selection of virulence traits and in adaptation to survival in macrophages. Thus, intra-amoebal growth was found to enhance virulence, and similar mechanisms seem to be implicated in the survival of ARB in response to both amoebae and macrophages. Moreover, free-living amoebae represent a useful tool for the culture of some intracellular bacteria and new bacterial species that might be potential emerging pathogens.}, }
@article {pmid15075277, year = {2004}, author = {Slapeta, J and Keithly, JS}, title = {Cryptosporidium parvum mitochondrial-type HSP70 targets homologous and heterologous mitochondria.}, journal = {Eukaryotic cell}, volume = {3}, number = {2}, pages = {483-494}, pmid = {15075277}, issn = {1535-9778}, support = {D43 TW000915/TW/FIC NIH HHS/United States ; TW00915-05/TW/FIC NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Cryptosporidium parvum/genetics/*metabolism/ultrastructure ; Escherichia coli Proteins/genetics ; Gene Expression ; HSP70 Heat-Shock Proteins/chemistry/genetics/*metabolism ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Mitochondria/genetics/*metabolism/ultrastructure ; Molecular Sequence Data ; Phylogeny ; Protein Sorting Signals ; Protein Structure, Secondary ; Protein Transport ; Sequence Alignment ; Sporozoites/ultrastructure ; }, abstract = {A mitochondrial HSP70 gene (Cp-mtHSP70) is described for the apicomplexan Cryptosporidium parvum, an agent of diarrhea in humans and animals. Mitochondrial HSP70 is known to have been acquired from the proto-mitochondrial endosymbiont. The amino acid sequence of Cp-mtHSP70 shares common domains with mitochondrial and proteobacterial homologues, including 34 amino acids of an NH2-terminal mitochondrion-like targeting presequence. Phylogenetic reconstruction places Cp-mtHSP70 within the mitochondrial clade of HSP70 homologues. Using reverse transcription-PCR, Cp-mtHSP70 mRNA was observed in C. parvum intracellular stages cultured in HCT-8 cells. Polyclonal antibodies to Cp-mtHSP70 recognize a approximately 70-kDa protein in Western blot analysis of sporozoite extracts. Both fluorescein- and immunogold-labeled anti-Cp-mtHSP70 localize to a single mitochondrial compartment in close apposition to the nucleus. Furthermore, the NH2-terminal presequence of Cp-mtHSP70 can correctly target green fluorescent protein to the single mitochondrion of the apicomplexan Toxoplasma gondii and the mitochondrial network of the yeast Saccharomyces cerevisiae. When this presequence was truncated, the predicted amphiphilic alpha-helix was shown to be essential for import into the yeast mitochondrion. These data further support the presence of a secondarily reduced relict mitochondrion in C. parvum.}, }
@article {pmid15073369, year = {2004}, author = {Dyall, SD and Brown, MT and Johnson, PJ}, title = {Ancient invasions: from endosymbionts to organelles.}, journal = {Science (New York, N.Y.)}, volume = {304}, number = {5668}, pages = {253-257}, doi = {10.1126/science.1094884}, pmid = {15073369}, issn = {1095-9203}, support = {AI27857/AI/NIAID NIH HHS/United States ; }, mesh = {Alphaproteobacteria/genetics/physiology ; *Bacterial Physiological Phenomena ; *Biological Evolution ; Chloroplasts/physiology ; Cyanobacteria/genetics/physiology ; Evolution, Molecular ; Genome ; Genome, Bacterial ; Mitochondria/*physiology ; Organelles/*physiology ; Origin of Life ; Plastids/*physiology ; Proteins/chemistry/metabolism ; *Symbiosis ; }, abstract = {The acquisitions of mitochondria and plastids were important events in the evolution of the eukaryotic cell, supplying it with compartmentalized bioenergetic and biosynthetic factories. Ancient invasions by eubacteria through symbiosis more than a billion years ago initiated these processes. Advances in geochemistry, molecular phylogeny, and cell biology have offered insight into complex molecular events that drove the evolution of endosymbionts into contemporary organelles. In losing their autonomy, endosymbionts lost the bulk of their genomes, necessitating the evolution of elaborate mechanisms for organelle biogenesis and metabolite exchange. In the process, symbionts acquired many host-derived properties, lost much of their eubacterial identity, and were transformed into extraordinarily diverse organelles that reveal complex histories that we are only beginning to decipher.}, }
@article {pmid15057483, year = {2004}, author = {Thao, ML and Baumann, P}, title = {Evidence for multiple acquisition of Arsenophonus by whitefly species (Sternorrhyncha: Aleyrodidae).}, journal = {Current microbiology}, volume = {48}, number = {2}, pages = {140-144}, doi = {10.1007/s00284-003-4157-7}, pmid = {15057483}, issn = {0343-8651}, mesh = {Animals ; Base Sequence ; Cluster Analysis ; DNA, Ribosomal/chemistry/isolation &amp; purification ; Enterobacteriaceae/*classification/genetics/*isolation &amp; purification ; Genes, rRNA/genetics ; Hemiptera/*microbiology ; Introns/genetics ; Molecular Sequence Data ; Phylogeny ; Polymorphism, Genetic ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology ; Symbiosis ; }, abstract = {Whiteflies contain primary prokaryotic endosymbionts located within specialized host cells. This endosymbiotic association is the result of a single infection of the host followed by vertical transmission of the endosymbiont to the progeny. Whiteflies may also be associated with other bacteria called secondary (S-) endosymbionts. The nucleotide sequence of the 16S-23S ribosomal DNA from S-endosymbionts of 13 whitefly species was determined. A phylogenetic analysis of these sequences indicated their grouping into two major clusters, one consisting of two S-endosymbionts related to previously described T-type endosymbionts. The second cluster contained the 16S-23S rDNA sequence of the type strain of Arsenophonus nasoniae as well as sequences of S-endosymbionts from 11 whitefly species. This Arsenophonus cluster contained four S-endosymbionts with intervening sequences of 70-184 nucleotides in their 23S rDNAs. The phylogenetic tree of the Arsenophonus cluster differed greatly from the phylogenetic tree of the primary endosymbionts. These results suggest that, unlike the primary endosymbiont, Arsenophonus may infect whiteflies multiple times and may also be horizontally transmitted.}, }
@article {pmid15049082, year = {2003}, author = {Hoti, SL and Sridhar, A and Das, PK}, title = {Presence of Wolbachia endosymbionts in microfilariae of Wuchereria bancrofti (Spirurida: Onchocercidae) from different geographical regions in India.}, journal = {Memorias do Instituto Oswaldo Cruz}, volume = {98}, number = {8}, pages = {1017-1019}, doi = {10.1590/s0074-02762003000800006}, pmid = {15049082}, issn = {0074-0276}, mesh = {Animals ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; India ; Microfilariae/*microbiology ; Polymerase Chain Reaction ; Wolbachia/*isolation &amp; purification ; Wuchereria bancrofti/*microbiology ; }, abstract = {In view of the recent discovery of rickettsial endosymbionts, Wolbachia in lymphatic filarial parasites, Wuchereria bancrofti and Brugia malayi and subsequently of their vital role in the survival and development of the latter, antibiotics such as tetracycline are being suggested for the treatment of lymphatic filariasis, by way of eliminating the endosymbiont. But, it is essential to assess their presence in parasites from areas endemic for lymphatic filariasis before such a new control tool is employed. In the present communication, we report the detection of Wolbachia endosymbionts in microfilariae of W. bancrofti parasites collected from geographically distant locations of India, such as Pondicherry (Union Territory), Calicut (Kerala), Jagadalpur (Madhya Pradesh), Thirukoilur (TamilNadu), Chinnanergunam (TamilNadu), Rajahmundry (Andhra Pradesh), and Varanasi (Uttar Pradesh), using Wolbachia specific 16S rDNA polymerase chain reaction.}, }
@article {pmid15046306, year = {2004}, author = {Coenye, T and Vandamme, P}, title = {Use of the genomic signature in bacterial classification and identification.}, journal = {Systematic and applied microbiology}, volume = {27}, number = {2}, pages = {175-185}, doi = {10.1078/072320204322881790}, pmid = {15046306}, issn = {0723-2020}, mesh = {Bacteria/*classification/*genetics ; Base Composition ; DNA, Bacterial/genetics ; *Genome, Bacterial ; Nucleic Acid Hybridization ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {In this study we investigated the correlation between dinucleotide relative abundance values (the genomic signature) obtained from bacterial whole-genome sequences and two parameters widely used for bacterial classification, 16S rDNA sequence similarity and DNA-DNA hybridisation values. Twenty-eight completely sequenced bacterial genomes were included in the study. The correlation between the genomic signature and DNA-DNA hybridisation values was high and taxa that showed less than 30% DNA-DNA binding will in general not have dinucleotide relative abundance dissimilarity (delta*) values below 40. On the other hand, taxa showing more than 50% DNA-DNA binding will not have delta* values higher than 17. Our data indicate that the overall correlation between genomic signature and 16S rDNA sequence similarity is low, except for closely related organisms (16S rDNA similarity >94%). Statistical analysis of delta* values between different subgroups of the Proteobacteria indicate that the beta- and gamma-Proteobacteria are more closely related to each other than to the other subgroups of the Proteobacteria and that the alpha- and epsilon-Proteobacteria form clearly separate subgroups. Using the genomic signature we have also predicted DNA-DNA binding values for fastidious or unculturable endosymbionts belonging to the genera Rickettsia, Wigglesworthia and Buchnera.}, }
@article {pmid15037105, year = {2004}, author = {Casiraghi, M and Bain, O and Guerrero, R and Martin, C and Pocacqua, V and Gardner, SL and Franceschi, A and Bandi, C}, title = {Mapping the presence of Wolbachia pipientis on the phylogeny of filarial nematodes: evidence for symbiont loss during evolution.}, journal = {International journal for parasitology}, volume = {34}, number = {2}, pages = {191-203}, doi = {10.1016/j.ijpara.2003.10.004}, pmid = {15037105}, issn = {0020-7519}, mesh = {Animals ; Base Sequence ; DNA, Mitochondrial/analysis ; Filarioidea/genetics/*parasitology ; Genes, Bacterial ; Genes, Helminth ; Host-Parasite Interactions ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction/methods ; Symbiosis ; Wolbachia/*classification/genetics ; }, abstract = {Wolbachia pipientis is a bacterial endosymbiont associated with arthropods and filarial nematodes. In filarial nematodes, W. pipientis has been shown to play an important role in the biology of the host and in the immuno-pathology of filariasis. Several species of filariae, including the most important parasites of humans and animals (e.g. Onchocerca volvulus, Wuchereria bancrofti and Dirofilaria immitis) have been shown to harbour these bacteria. Other filarial species, including an important rodent species (Acanthocheilonema viteae), which has been used as a model for the study of filariasis, do not appear to harbour these symbionts. There are still several open questions about the distribution of W. pipientis in filarial nematodes. Firstly the number of species examined is still limited. Secondly, it is not clear whether the absence of W. pipientis in negative species could represent an ancestral characteristic or the result of a secondary loss. Thirdly, several aspects of the phylogeny of filarial nematodes are still unclear and it is thus difficult to overlay the presence/absence of W. pipientis on a tree representing filarial evolution. Here we present the results of a PCR screening for W. pipientis in 16 species of filariae and related nematodes, representing different families/subfamilies. Evidence for the presence of W. pipientis is reported for five species examined for the first time (representing the genera Litomosoides, Litomosa and Dipetalonema); original results on the absence of this bacterium are reported for nine species; for the remaining two species, we have confirmed the absence of W. pipientis recently reported by other authors. In the positive species, the infecting W. pipientis bacteria have been identified through 16S rDNA gene sequence analysis. In addition to the screening for W. pipientis in 16 species, we have generated phylogenetic reconstructions based on mitochondrial gene sequences (12S rDNA; COI), including a total of 28 filarial species and related spirurid nematodes. The mapping of the presence/absence of W. pipientis on the trees generated indicates that these bacteria have possibly been lost during evolution along some lineages of filarial nematodes.}, }
@article {pmid15033707, year = {2003}, author = {Chose, O and Sarde, CO and Noël, C and Gerbod, D and Jimenez, JC and Brenner, C and Capron, M and Viscogliosi, E and Roseto, A}, title = {Cell death in protists without mitochondria.}, journal = {Annals of the New York Academy of Sciences}, volume = {1010}, number = {}, pages = {121-125}, doi = {10.1196/annals.1299.021}, pmid = {15033707}, issn = {0077-8923}, mesh = {Animals ; Apoptosis/*physiology ; Cell Death/*physiology ; Eukaryota/*physiology/ultrastructure ; Giardia lamblia/cytology/physiology ; Humans ; Hydrogen/metabolism ; Mitochondria/*physiology ; Symbiosis ; Trichomonas vaginalis/cytology/physiology ; }, abstract = {Some protozoans, such as Trichomonad species, do not possess mitochondria. Most of the time, they harbor another type of membrane-bounded organelle, called hydrogenosome from its capacity to produce H(2). This is the case for the human parasite Trichomonas vaginalis. Some other parasites, such as the protist Giardia lamblia, do not harbor any of these organelles. From this observation arises naturally a naive question: How do cells die when the mitochondrion, the cornerstone of apoptotic process, is absent? Data strongly suggest that the mitochondrion and the hydrogenosome arose from a common ancestral endosymbiont. But hydrogenosomes do not appear to directly substitute for mitochondria in apoptotic functions. Thus, it appears judicious to examine more closely the genome of unicellular cells, which do not harbor mitochondria, and search for new molecules that could participate in the apoptotic process in these microorganisms.}, }
@article {pmid15033524, year = {2004}, author = {Richly, E and Leister, D}, title = {An improved prediction of chloroplast proteins reveals diversities and commonalities in the chloroplast proteomes of Arabidopsis and rice.}, journal = {Gene}, volume = {329}, number = {}, pages = {11-16}, doi = {10.1016/j.gene.2004.01.008}, pmid = {15033524}, issn = {0378-1119}, mesh = {Arabidopsis/genetics/*metabolism ; Chloroplasts/*metabolism ; Cyanobacteria/genetics ; Genetic Variation ; Oryza/genetics/*metabolism ; Plant Proteins/genetics/metabolism ; Proteome/genetics/*metabolism ; Reproducibility of Results ; *Software ; Species Specificity ; }, abstract = {Proteins that form part of the chloroplast proteome can be identified by computational prediction of the N-terminal presequences (chloroplast transit peptides, cTPs) of their cytoplasmic precursor proteins. The accuracy of four different cTP predictors has been evaluated on a test set of 4500 proteins whose subcellular localization is known, and was found to be substantially lower than previously reported. A combination of cTP prediction programs was superior to any one of the predictors alone. This combination was employed to estimate the size and composition of the chloroplast proteomes of Arabidopsis and rice, and about 2100 (Arabidopsis thaliana) and 4800 (Oryza sativa) different chloroplast proteins with a cTP are predicted to be encoded by their nuclear genomes. A subset of around 900 chloroplast proteins, predominantly derived from the cyanobacterial endosymbiont and with functions mostly related to metabolism, energy and transcription, is shared by the two species. This points to the existence of both conserved nucleus-encoded chloroplast proteins that are predominantly of prokaryotic origin, and a large fraction of taxon-specific chloroplast-targeted proteins, in flowering plants.}, }
@article {pmid15033465, year = {2004}, author = {Fuglsang, A}, title = {The relationship between palindrome avoidance and intragenic codon usage variations: a Monte Carlo study.}, journal = {Biochemical and biophysical research communications}, volume = {316}, number = {3}, pages = {755-762}, doi = {10.1016/j.bbrc.2004.02.117}, pmid = {15033465}, issn = {0006-291X}, mesh = {Algorithms ; Base Composition ; Base Sequence ; Buchnera/genetics ; *Codon ; Escherichia coli/genetics ; Genome ; *Monte Carlo Method ; Wigglesworthia/genetics ; }, abstract = {Several studies have shown that codon usage within genes varies, as it seems dependent on both codon context and codon position within the gene. Given that palindromes in addition often are avoided in genomes, this study aimed at finding out if intragenic variations in codon usage may be a way to control the amount and location of palindromes. A Monte Carlo algorithm was written which resampled the codons in genes while keeping the amino acid sequence of the translation product constant. On the resampled sequences, palindromes were counted and their intragenic positions mapped. Escherichia coli K12 uses type II restriction-modification systems and displays pronounced codon usage phenomena. Using this as a reference organism it was clearly shown that the number of palindromes in genes is generally lower than the amount of palindromes in resampled genes; thus, the succession of codons seems to be a way to decrease the number of palindromes. The intragenic position of palindromes in resampled sequences, however, was largely equal to the position in the native genes, so codon usage phenomena are unlikely to be a way to control the intragenic position of palindromes. The analysis was repeated on two bacteriophages and gave similar same results, even though the virus genomes are much smaller. Studies on the endosymbionts Buchnera sp. APS and Wigglesworthia sp., which seemingly have no type II restriction-modification systems, showed that in these species there is only weak evidence for codon usage acting to control the number of palindromes.}, }
@article {pmid15028723, year = {2004}, author = {Banerjee, S and Hess, D and Majumder, P and Roy, D and Das, S}, title = {The Interactions of Allium sativum leaf agglutinin with a chaperonin group of unique receptor protein isolated from a bacterial endosymbiont of the mustard aphid.}, journal = {The Journal of biological chemistry}, volume = {279}, number = {22}, pages = {23782-23789}, doi = {10.1074/jbc.M401405200}, pmid = {15028723}, issn = {0021-9258}, mesh = {Agglutinins/*metabolism ; Amino Acid Sequence ; Bacterial Proteins/genetics/*metabolism ; Chaperonins/genetics/metabolism ; Garlic/*metabolism ; Models, Molecular ; Molecular Sequence Data ; Mustard Plant/microbiology ; Protein Binding ; Receptors, Cell Surface/genetics/metabolism ; Symbiosis ; }, abstract = {The homopteran sucking insect, Lipaphis erysimi (mustard aphid) causes severe damage to various crops. This pest not only affects plants by sucking on the phloem, but it also transmits single-stranded RNA luteoviruses while feeding, which cause disease and damage in the crop. The mannose-binding Allium sativum (garlic) leaf lectin has been found to be a potent control agent of L. erysimi. The lectin receptor protein isolated from brush border membrane vesicle of insect gut was purified to determine the mechanism of lectin binding to the gut. Purified receptor was identified as an endosymbiotic chaperonin, symbionin, using liquid chromatography-tandem mass spectrometry. Symbionin from endosymbionts of other aphid species have been reported to play a significant role in virus transmission by binding to the read-through domain of the viral coat protein. To understand the molecular interactions of the said lectin and this unique symbionin molecule, the model structures of both molecules were generated using the Modeller program. The interaction was confirmed through docking of the two molecules forming a complex. A surface accessibility test of these molecules demonstrated a significant reduction in the accessibility of the complex molecule compared with that of the free symbionin molecule. This reduction in surface accessibility may have an effect on other molecular interactive processes, including "symbionin virion recognition", which is essential for such symbionin-mediated virus transmission. Thus, garlic leaf lectin provides an important component of a crop management program by controlling, on one hand, aphid attack and on the other hand, symbionin-mediated luteovirus transmission.}, }
@article {pmid15022768, year = {2004}, author = {Siddall, ME and Perkins, SL and Desser, SS}, title = {Leech mycetome endosymbionts are a new lineage of alphaproteobacteria related to the Rhizobiaceae.}, journal = {Molecular phylogenetics and evolution}, volume = {30}, number = {1}, pages = {178-186}, doi = {10.1016/s1055-7903(03)00184-2}, pmid = {15022768}, issn = {1055-7903}, mesh = {Alphaproteobacteria/classification/genetics/*physiology ; Animals ; Base Sequence ; DNA/genetics/isolation &amp; purification ; DNA Primers ; Evolution, Molecular ; In Situ Hybridization, Fluorescence ; Leeches/anatomy &amp; histology/*microbiology/*physiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Rhizobiaceae/classification/genetics/*physiology ; Symbiosis ; }, abstract = {Mycetomal organs attached to the esophagus of hematophagous leeches which are known to harbor endosymbiotic bacteria were removed from three species in the leech family Glossiphoniidae. Anatomical observations indicated that placobdellid mycetomes are paired and caecate, inserting into the esophagus posterior to the proboscis. Light and electron microscopy demonstrated that there is a single layer of mycetome epithelial cells harboring gram-negative rods and that these epithelial cells are ultrastructurally distinct from neighboring esophageal epithelial cells. Fluorescent in situ hybridization with eubacterial and alphaproteobacterial probes localized the bacteria solely to the mycetomes both in adult and in unfed juvenile leeches whereas a gammaproteobacterial probe did not yield a bound fluorescencent signal. DNA was isolated from these tissues and subjected to PCR amplification using bacteria-specific primers for 16S and 23S rDNA. Results from sequencing the amplification products and phylogenetic analysis with other Alphaproteobacteria revealed that the bacteria resident in these organs comprise a new genus of Alphaproteobacteria, Reichenowia n. gen., closely related to the nitrogen-fixing, nodule-forming Rhizobiaceae. The three bacterial strains, though different from each other were each other's closest relatives, suggesting a history of close coevolution with their leech hosts.}, }
@article {pmid15018108, year = {2004}, author = {Baumann, L and Thao, ML and Funk, CJ and Falk, BW and Ng, JC and Baumann, P}, title = {Sequence analysis of DNA fragments from the genome of the primary endosymbiont of the whitefly Bemisia tabaci.}, journal = {Current microbiology}, volume = {48}, number = {1}, pages = {77-81}, doi = {10.1007/s00284-003-4132-3}, pmid = {15018108}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal Spacer/chemistry/genetics ; Hemiptera/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Proteobacteria/*genetics ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis/genetics ; }, abstract = {The whitefly Bemisia tabaci contains a primary prokaryotic endosymbiont housed within specialized cells in the body cavity. Two DNA fragments from the endosymbiont, totaling 33.3 kilobases, were cloned and sequenced. In total, 37 genes were detected and included the ribosomal RNA operon and genes for ribosomal RNA proteins. The guanine plus cytosine of the DNA was 30.2 mol%, different from that of endosymbionts of other plant sap-sucking insects.}, }
@article {pmid15014155, year = {2004}, author = {Canbäck, B and Tamas, I and Andersson, SG}, title = {A phylogenomic study of endosymbiotic bacteria.}, journal = {Molecular biology and evolution}, volume = {21}, number = {6}, pages = {1110-1122}, doi = {10.1093/molbev/msh122}, pmid = {15014155}, issn = {0737-4038}, mesh = {Animals ; Base Composition ; Base Sequence ; Cluster Analysis ; Databases, Genetic ; *Evolution, Molecular ; Gammaproteobacteria/*genetics ; *Genome, Bacterial ; Insecta/microbiology ; Models, Genetic ; *Phylogeny ; Selection, Genetic ; Sequence Alignment ; *Symbiosis ; }, abstract = {Endosymbiotic bacteria of aphids, Buchnera aphidicola, and tsetse flies, Wigglesworthia glossinidia, are descendents of free-living gamma-Proteobacteria. The acceleration of sequence evolution in the endosymbiont genomes is here estimated from a phylogenomic analysis of the gamma-Proteobacteria. The tree topologies associated with the most highly conserved genes suggest that the endosymbionts form a sister group with Escherichia coli, Salmonella sp., and Yersinia pestis. Our results indicate that deviant tree topologies result from high substitution rates and biased nucleotide patterns, rather than from lateral gene transfer, as previously suggested. A reinvestigation of the relative rate increase in the endosymbiont genomes reveals variability among genes that correlate with host-associated metabolic dependencies. The conclusion is that host-level selection has retarded both the loss of genes and the acceleration of sequence evolution in endocellular symbionts.}, }
@article {pmid15012229, year = {1998}, author = {Schnell, DJ}, title = {PROTEIN TARGETING TO THE THYLAKOID MEMBRANE.}, journal = {Annual review of plant physiology and plant molecular biology}, volume = {49}, number = {}, pages = {97-126}, doi = {10.1146/annurev.arplant.49.1.97}, pmid = {15012229}, issn = {1040-2519}, abstract = {The assembly of the photosynthetic apparatus at the thylakoid begins with the targeting of proteins from their site of synthesis in the cytoplasm or stroma to the thylakoid membrane. Plastid-encoded proteins are targeted directly to the thylakoid during or after synthesis on plastid ribosomes. Nuclear-encoded proteins undergo a two-step targeting process requiring posttranslational import into the organelle from the cytoplasm and subsequent targeting to the thylakoid membrane. Recent investigations have revealed a single general import machinery at the envelope that mediates the direct transport of preproteins from the cytoplasm to the stroma. In contrast, at least four distinct pathways exist for the targeting of proteins to the thylakoid membrane. At least two of these systems are homologous to translocation systems that operate in bacteria and at the endoplasmic reticulum, indicating that elements of the targeting mechanisms have been conserved from the original prokaryotic endosymbiont.}, }
@article {pmid15010601, year = {2003}, author = {Hofmann, NR and Theg, SM}, title = {Physcomitrella patens as a model for the study of chloroplast protein transport: conserved machineries between vascular and non-vascular plants.}, journal = {Plant molecular biology}, volume = {53}, number = {5}, pages = {621-632}, pmid = {15010601}, issn = {0167-4412}, mesh = {Bryopsida/*genetics/metabolism ; Chloroplasts/*metabolism ; Cloning, Molecular ; DNA, Complementary/chemistry/genetics ; Evolution, Molecular ; Models, Biological ; Molecular Sequence Data ; Phylogeny ; Plant Proteins/*genetics/metabolism ; Plant Structures/genetics/metabolism ; Plants/genetics/metabolism ; Protein Transport ; Sequence Analysis, DNA ; }, abstract = {A single general import pathway in vascular plants mediates the transport of precursor proteins across the two membranes of the chloroplast envelope, and at least four pathways are responsible for thylakoid protein targeting. While the transport systems in the thylakoid are related to bacterial secretion systems, the envelope machinery is thought to have arisen with the endosymbiotic event and to be derived, at least in part, from proteins present in the original endosymbiont. Recently the moss Physcomitrella patens has gained worldwide attention for its ability to undergo homologous recombination in the nuclear genome at rates unseen in any other land plants. Because of this, we were interested to know whether it would be a useful model system for studying chloroplast protein transport. We searched the large database of P. patens expressed sequence tags for chloroplast transport components and found many putative homologues. We obtained full-length sequences for homologues of three Toc components from moss. To our knowledge, this is the first sequence information for these proteins from non-vascular plants. In addition to identifying components of the transport machinery from moss, we isolated plastids and tested their activity in protein import assays. Our data indicate that moss and pea (Pisum sativum) plastid transport systems are functionally similar. These findings identify P. patens as a potentially useful tool for combining genetic and biochemical approaches for the study of chloroplast protein targeting.}, }
@article {pmid15003491, year = {2004}, author = {Roberts, CW and Roberts, F and Henriquez, FL and Akiyoshi, D and Samuel, BU and Richards, TA and Milhous, W and Kyle, D and McIntosh, L and Hill, GC and Chaudhuri, M and Tzipori, S and McLeod, R}, title = {Evidence for mitochondrial-derived alternative oxidase in the apicomplexan parasite Cryptosporidium parvum: a potential anti-microbial agent target.}, journal = {International journal for parasitology}, volume = {34}, number = {3}, pages = {297-308}, doi = {10.1016/j.ijpara.2003.11.002}, pmid = {15003491}, issn = {0020-7519}, support = {N01 AI25466/AI/NIAID NIH HHS/United States ; R01 AI-43228/AI/NIAID NIH HHS/United States ; R01 AI-50471/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Coccidiostats/*pharmacology ; Cryptosporidium parvum/*drug effects/enzymology/growth &amp; development ; Dose-Response Relationship, Drug ; Enzyme Inhibitors/pharmacology ; Genes, Protozoan ; Genome ; Mitochondria/*enzymology ; Mitochondrial Proteins ; Molecular Sequence Data ; Oxidoreductases/*antagonists &amp; inhibitors/genetics/metabolism ; Oxyquinoline/pharmacology ; Phylogeny ; Plant Proteins ; Plasmodium falciparum/drug effects/growth &amp; development ; Salicylamides/pharmacology ; Sequence Alignment ; Toxoplasma/drug effects/growth &amp; development ; }, abstract = {The observation that Plasmodium falciparum possesses cyanide insensitive respiration that can be inhibited by salicylhydroxamic acid (SHAM) and propyl gallate is consistent with the presence of an alternative oxidase (AOX). However, the completion and annotation of the P. falciparum genome project did not identify any protein with convincing similarity to the previously described AOXs from plants, fungi or protozoa. We undertook a survey of the available apicomplexan genome projects in an attempt to address this anomaly. Putative AOX sequences were identified and sequenced from both type 1 and 2 strains of Cryptosporidium parvum. The gene encodes a polypeptide of 336 amino acids and has a predicted N-terminal transit sequence similar to that found in proteins targeted to the mitochondria of other species. The potential of AOX as a target for new anti-microbial agents for C. parvum is evident by the ability of SHAM and 8-hydroxyquinoline to inhibit in vitro growth of C. parvum. In spite of the lack of a good candidate for AOX in either the P. falciparum or Toxoplasma gondii genome projects, SHAM and 8-hydroxyquinoline were found to inhibit the growth of these parasites. Phylogenetic analysis suggests that AOX and the related protein immutans are derived from gene transfers from the mitochondrial endosymbiont and the chloroplast endosymbiont, respectively. These data are consistent with the functional localisation studies conducted thus far, which demonstrate mitochondrial localisation for some AOX and chloroplastidic localization for immutans. The presence of a mitochondrial compartment is further supported by the prediction of a mitochondrial targeting sequence at the N-terminus of the protein and MitoTracker staining of a subcellular compartment in trophozoite and meront stages. These results give insight into the evolution of AOX and demonstrate the potential of targeting the alternative pathway of respiration in apicomplexans.}, }
@article {pmid15003488, year = {2004}, author = {Huang, J and Mullapudi, N and Sicheritz-Ponten, T and Kissinger, JC}, title = {A first glimpse into the pattern and scale of gene transfer in Apicomplexa.}, journal = {International journal for parasitology}, volume = {34}, number = {3}, pages = {265-274}, doi = {10.1016/j.ijpara.2003.11.025}, pmid = {15003488}, issn = {0020-7519}, support = {1R01AI045806-01A1/AI/NIAID NIH HHS/United States ; AI05093/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Apicomplexa/*genetics ; Cryptosporidium parvum/genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; *Genes, Protozoan ; Genomics ; Phylogeny ; Plasmodium falciparum/genetics ; Theileria annulata/genetics ; Toxoplasma/genetics ; }, abstract = {Reports of plant-like and bacterial-like genes for a number of parasitic organisms, most notably those within the Apicomplexa and Kinetoplastida, have appeared in the literature over the last few years. Among the apicomplexan organisms, following discovery of the apicomplexan plastid (apicoplast), the discovery of plant-like genes was less surprising although the extent of transfer and the relationship of transferred genes to the apicoplast remained unclear. We used new genome sequence data to begin a systematic examination of the extent and origin of transferred genes in the Apicomplexa combined with a phylogenomic approach to detect potential gene transfers in four apicomplexan genomes. We have detected genes of algal nuclear, chloroplast (cyanobacterial) and proteobacterial origin. Plant-like genes were detected in species not currently harbouring a plastid (e.g. Cryptosporidium parvum) and putatively transferred genes were detected that appear to be unrelated to the function of the apicoplast. While the mechanism of acquisition for many of the identified genes is not certain, it appears that some were most likely acquired via intracellular gene transfer from an algal endosymbiont while others may have been acquired via horizontal gene transfer.}, }
@article {pmid14998511, year = {2004}, author = {Jolodar, A and Fischer, P and Büttner, DW and Brattig, NW}, title = {Wolbachia endosymbionts of Onchocerca volvulus express a putative periplasmic HtrA-type serine protease.}, journal = {Microbes and infection}, volume = {6}, number = {2}, pages = {141-149}, doi = {10.1016/j.micinf.2003.10.013}, pmid = {14998511}, issn = {1286-4579}, mesh = {Amino Acid Sequence ; Animals ; Molecular Sequence Data ; Onchocerca volvulus/*microbiology ; Periplasm/*enzymology ; Serine Endopeptidases/genetics/*metabolism ; Symbiosis/*physiology ; Wolbachia/*enzymology/genetics/physiology ; }, abstract = {Wolbachia are intracellular bacteria of many filarial nematodes. A mutualistic interaction between the endobacteria and the filarial host is likely, because the clearance of Wolbachia by tetracycline leads to the obstruction of embryogenesis and larval development. Databases were searched for exported molecules to identify candidates involved in this mutualism. Fragments of a Wolbachia serine protease from the human filarial parasite Onchocerca volvulus were obtained (Wol-Ov-HtrA) by the use of a PCR technique and primers based on the Rickettsia prowazekii genome. The deduced amino acid sequence exhibited 87% and 81% identity to the homologous Wolbachia proteases identified from Brugia malayi and Drosophila melanogaster, respectively. The full-length cDNA encodes 494 amino acids with a calculated mass of 54 kDa. Three characteristic features, (i) a catalytic triad of serine proteases, (ii) two PDZ domains and (iii) a putative signal peptide, classify the endobacterial protein as a member of the periplasmic HtrA family of proteases known to express chaperone and regulator activity of apoptosis. Using a rabbit antiserum raised against a recombinantly expressed 33-kDa fragment of Wol-Ov-HtrA, strong labelling of the antigen was found associated with endobacteria in hypodermis, oocytes, zygotes, all embryonic stages and microfilariae of O. volvulus. Staining of hypodermal cytoplasm surrounding the endobacteria indicated a possible release of the protein from the Wolbachia. The demonstration of Wol-Ov-HtrA-reactive IgG1 antibodies in sera of O. volvulus-infected persons indicated the exposure to the protein and its recognition by the human immune system. Wol-Ov-HtrA is a candidate for an exported Wolbachia protein that may interact with the filarial host metabolism.}, }
@article {pmid14982636, year = {2004}, author = {Tjaden, J and Haferkamp, I and Boxma, B and Tielens, AG and Huynen, M and Hackstein, JH}, title = {A divergent ADP/ATP carrier in the hydrogenosomes of Trichomonas gallinae argues for an independent origin of these organelles.}, journal = {Molecular microbiology}, volume = {51}, number = {5}, pages = {1439-1446}, doi = {10.1111/j.1365-2958.2004.03918.x}, pmid = {14982636}, issn = {0950-382X}, mesh = {Adenosine Diphosphate/metabolism ; Adenosine Triphosphate/metabolism ; Animals ; Anti-Bacterial Agents/metabolism ; Bongkrekic Acid/metabolism ; Escherichia coli/genetics/metabolism ; *Evolution, Molecular ; Hydrogen/metabolism ; Mitochondrial ADP, ATP Translocases/classification/genetics/*metabolism ; Molecular Sequence Data ; Organelles/*metabolism ; Phylogeny ; Plant Proteins/metabolism ; Protozoan Proteins/classification/genetics/*metabolism ; Trichomonas/*cytology/*metabolism ; }, abstract = {The evolution of mitochondrial ADP and ATP exchanging proteins (AACs) highlights a key event in the evolution of the eukaryotic cell, as ATP exporting carriers were indispensable in establishing the role of mitochondria as ATP-generating cellular organelles. Hydrogenosomes, i.e. ATP- and hydrogen-generating organelles of certain anaerobic unicellular eukaryotes, are believed to have evolved from the same ancestral endosymbiont that gave rise to present day mitochondria. Notably, the hydrogenosomes of the parasitic anaerobic flagellate Trichomonas seemed to be deficient in mitochondrial-type AACs. Instead, HMP 31, a different member of the mitochondrial carrier family (MCF) with a hitherto unknown function, is abundant in the hydrogenosomal membranes of Trichomonas vaginalis. Here we show that the homologous HMP 31 of closely related Trichomonas gallinae specifically transports ADP and ATP with high efficiency, as do genuine mitochondrial AACs. However, phylogenetic analysis and its resistance against bongkrekic acid (BKA, an efficient inhibitor of mitochondrial-type AACs) identify HMP 31 as a member of the mitochondrial carrier family that is distinct from all mitochondrial and hydrogenosomal AACs studied so far. Thus, our data support the hypothesis that the various hydrogenosomes evolved repeatedly and independently.}, }
@article {pmid14979660, year = {2004}, author = {Islas, S and Becerra, A and Luisi, PL and Lazcano, A}, title = {Comparative genomics and the gene complement of a minimal cell.}, journal = {Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life}, volume = {34}, number = {1-2}, pages = {243-256}, pmid = {14979660}, issn = {0169-6149}, mesh = {*Cells ; Electrophoresis, Gel, Pulsed-Field ; *Genomics ; }, abstract = {The concept of a minimal cell is discussed from the viewpoint of comparative genomics. Analysis of published DNA content values determined for 641 different archaeal and bacterial species by pulsed field gel electrophoresis has lead to a more precise definition of the genome size ranges of free-living and host-associated organisms. DNA content is not an indicator of phylogenetic position. However, the smallest genomes in our sample do not have a random distribution in rRNA-based evolutionary trees, and are found mostly in (a) the basal branches of the tree where thermophiles are located; and (b) in late clades, such as those of Gram positive bacteria. While the smallest-known genome size for an endosymbiont is only 450 kb, no free-living prokaryote has been described to have genomes < 1450 kb. Estimates of the size of minimal gene complement can provide important insights in the primary biological functions required for a sustainable, reproducing cell nowadays and throughout evolutionary times, but definitions of the minimum cell is dependent on specific environments.}, }
@article {pmid14973020, year = {2004}, author = {Benson, HP and LeVier, K and Guerinot, ML}, title = {A dominant-negative fur mutation in Bradyrhizobium japonicum.}, journal = {Journal of bacteriology}, volume = {186}, number = {5}, pages = {1409-1414}, pmid = {14973020}, issn = {0021-9193}, support = {T32 AI007519/AI/NIAID NIH HHS/United States ; T32 AI07519/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Bacterial Outer Membrane Proteins/genetics/metabolism ; Bacterial Proteins/chemistry/*genetics/metabolism ; Bradyrhizobium/drug effects/*genetics/growth &amp; development/*physiology ; Drug Resistance, Bacterial ; Fabaceae/microbiology ; Gene Expression Regulation, Bacterial ; Manganese/pharmacology ; Molecular Sequence Data ; *Mutation ; Repressor Proteins/chemistry/*genetics/metabolism ; Sequence Analysis, DNA ; Soybeans/*microbiology ; *Symbiosis ; }, abstract = {In many bacteria, the ferric uptake regulator (Fur) protein plays a central role in the regulation of iron uptake genes. Because iron figures prominently in the agriculturally important symbiosis between soybean and its nitrogen-fixing endosymbiont Bradyrhizobium japonicum, we wanted to assess the role of Fur in the interaction. We identified a fur mutant by selecting for manganese resistance. Manganese interacts with the Fur protein and represses iron uptake genes. In the presence of high levels of manganese, bacteria with a wild-type copy of the fur gene repress iron uptake systems and starve for iron, whereas fur mutants fail to repress iron uptake systems and survive. The B. japonicum fur mutant, as expected, fails to repress iron-regulated outer membrane proteins in the presence of iron. Unexpectedly, a wild-type copy of the fur gene cannot complement the fur mutant. Expression of the fur mutant allele in wild-type cells leads to a fur phenotype. Unlike a B. japonicum fur-null mutant, the strain carrying the dominant-negative fur mutation is unable to form functional, nitrogen-fixing nodules on soybean, mung bean, or cowpea, suggesting a role for a Fur-regulated protein or proteins in the symbiosis.}, }
@article {pmid14965905, year = {2004}, author = {Degnan, PH and Lazarus, AB and Brock, CD and Wernegreen, JJ}, title = {Host-symbiont stability and fast evolutionary rates in an ant-bacterium association: cospeciation of camponotus species and their endosymbionts, candidatus blochmannia.}, journal = {Systematic biology}, volume = {53}, number = {1}, pages = {95-110}, doi = {10.1080/10635150490264842}, pmid = {14965905}, issn = {1063-5157}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/*genetics ; Base Sequence ; Bayes Theorem ; DNA Primers ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; Enterobacteriaceae/*genetics ; *Evolution, Molecular ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Bacterial endosymbionts are widespread across several insect orders and are involved in interactions ranging from obligate mutualism to reproductive parasitism. Candidatus Blochmannia gen. nov. (Blochmannia) is an obligate bacterial associate of Camponotus and related ant genera (Hymenoptera: Formicidae). The occurrence of Blochmannia in all Camponotus species sampled from field populations and its maternal transmission to host offspring suggest that this bacterium is engaged in a long-term, stable association with its ant hosts. However, evidence for cospeciation in this system is equivocal because previous phylogenetic studies were based on limited gene sampling, lacked statistical analysis of congruence, and have even suggested host switching. We compared phylogenies of host genes (the nuclear EF-1alphaF2 and mitochondrial COI/II) and Blochmannia genes (16S ribosomal DNA [rDNA], groEL, gidA, and rpsB), totaling more than 7 kilobases for each of 16 Camponotus species. Each data set was analyzed using maximum likelihood and Bayesian phylogenetic reconstruction methods. We found minimal conflict among host and symbiont phylogenies, and the few areas of discordance occurred at deep nodes that were poorly supported by individual data sets. Concatenated protein-coding genes produced a very well-resolved tree that, based on the Shimodaira-Hasegawa test, did not conflict with any host or symbiont data set. Correlated rates of synonymous substitution (d(S)) along corresponding branches of host and symbiont phylogenies further supported the hypothesis of cospeciation. These findings indicate that Blochmannia-Camponotus symbiosis has been evolutionarily stable throughout tens of millions of years. Based on inferred divergence times among the ant hosts, we estimated rates of sequence evolution of Blochmannia to be approximately 0.0024 substitutions per site per million years (s/s/MY) for the 16S rDNA gene and approximately 0.1094 s/s/MY at synonymous positions of the genes sampled. These rates are several-fold higher than those for related bacteria Buchnera aphidicola and Escherichia coli. Phylogenetic congruence among Blochmannia genes indicates genome stability that typifies primary endosymbionts of insects.}, }
@article {pmid14739247, year = {2004}, author = {Lucattini, R and Likic, VA and Lithgow, T}, title = {Bacterial proteins predisposed for targeting to mitochondria.}, journal = {Molecular biology and evolution}, volume = {21}, number = {4}, pages = {652-658}, doi = {10.1093/molbev/msh058}, pmid = {14739247}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics/metabolism ; Computational Biology ; Escherichia coli Proteins/*genetics/metabolism ; *Evolution, Molecular ; Mitochondria/*metabolism ; Mitochondrial Proteins/*genetics/metabolism ; Models, Biological ; Molecular Sequence Data ; Protein Transport/genetics ; Saccharomyces cerevisiae Proteins/genetics/metabolism ; Sequence Alignment ; }, abstract = {Mitochondria evolved from an endosymbiotic proteobacterium in a process that required the transfer of genes from the bacterium to the host cell nucleus, and the translocation of proteins thereby made in the host cell cytosol into the internal compartments of the organelle. According to current models for this evolution, two highly improbable events are required to occur simultaneously: creation of a protein translocation machinery to import proteins back into the endosymbiont and creation of targeting sequences on the protein substrates themselves. Using a combination of two independent prediction methods, validated through tests on simulated genomes, we show that at least 5% of proteins encoded by an extant proteobacterium are predisposed for targeting to mitochondria, and propose we that mitochondrial targeting information was preexisting for many proteins of the endosymbiont. We analyzed a family of proteins whose members exist both in bacteria and in mitochondria of eukaryotes and show that the amino-terminal extensions occasionally found in bacterial family members can function as a crude import sequence when the protein is presented to isolated mitochondria. This activity leaves the development of a primitive translocation channel in the outer membrane of the endosymbiont as a single hurdle to initiating the evolution of mitochondria.}, }
@article {pmid14739242, year = {2004}, author = {Lefèvre, C and Charles, H and Vallier, A and Delobel, B and Farrell, B and Heddi, A}, title = {Endosymbiont phylogenesis in the dryophthoridae weevils: evidence for bacterial replacement.}, journal = {Molecular biology and evolution}, volume = {21}, number = {6}, pages = {965-973}, doi = {10.1093/molbev/msh063}, pmid = {14739242}, issn = {0737-4038}, mesh = {Animals ; Base Composition ; Base Sequence ; DNA Primers ; DNA, Ribosomal/genetics ; Evolution, Molecular ; Gammaproteobacteria/*genetics ; In Situ Hybridization, Fluorescence ; Likelihood Functions ; Models, Genetic ; Molecular Sequence Data ; *Phylogeny ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; Weevils/*microbiology ; }, abstract = {Intracellular symbiosis is widespread in the insect world where it plays an important role in evolution and adaptation. The weevil family Dryophthoridae (Curculionoidea) is of particular interest in intracellular symbiosis evolution with regard to the great economical and ecological features of these invasive insects, and the potential for comparative studies across a wide range of host plants and environments. Here, we have analyzed the intracellular symbiotic bacteria of 19 Dryophthoridae species collected worldwide, representing a wide range of plant species and tissues. All except one (Sitophilus linearis) harbor symbiotic bacteria within specialized cells (the bacteriocytes) assembled as an organ, the bacteriome. Phylogenetic analysis of the 16S rDNA gene sequence of the Dryophthoridae endosymbionts revealed three endosymbiotic clades belonging to gamma3-Proteobacteria and characterized by different GC contents and evolutionary rate. The genus name Candidatus Nardonella was proposed for the ancestral clade infesting Dryophthoridae 100 MYA and represented by five of nine bacterial genera studied. For this clade showing low GC content (40.5% GC) and high evolutionary rate (0.128 substitutions/site per 100 Myr), a single infection and subsequent cospeciation of the host and the endosymbionts was observed. In the two other insect lineage endosymbionts, with relatively high GC content (53.4% and 53.8% GC), competition with ancestral pathogenic bacteria might have occurred, leading to endosymbiont replacement in present-day last insects.}, }
@article {pmid14733727, year = {2003}, author = {Hise, AG and Gillette-Ferguson, I and Pearlman, E}, title = {Immunopathogenesis of Onchocerca volvulus keratitis (river blindness): a novel role for TLR4 and endosymbiotic Wolbachia bacteria.}, journal = {Journal of endotoxin research}, volume = {9}, number = {6}, pages = {390-394}, doi = {10.1179/096805103225002746}, pmid = {14733727}, issn = {0968-0519}, support = {K08 AI054652/AI/NIAID NIH HHS/United States ; EY 10230/EY/NEI NIH HHS/United States ; EY 11373/EY/NEI NIH HHS/United States ; }, mesh = {Animals ; Keratitis/*etiology/immunology/microbiology/parasitology ; Membrane Glycoproteins/immunology/*metabolism ; Mice ; Mice, Inbred C3H ; Mice, Mutant Strains ; Models, Biological ; Onchocerca volvulus/*immunology/ultrastructure ; Onchocerciasis, Ocular/immunology/*microbiology/parasitology/pathology ; Receptors, Cell Surface/immunology/*metabolism ; Symbiosis/*immunology ; Toll-Like Receptor 4 ; Toll-Like Receptors ; Wolbachia/*immunology/metabolism ; }, abstract = {Infection with the parasitic nematode Onchocerca volvulus is associated with inflammation of the skin and cornea that can lead to blindness. Corneal damage is thought to occur as a result of the host inflammatory responses to degenerating microfilariae in the eye. We have utilized a murine model of corneal inflammation (keratitis) to investigate the immune and inflammatory responses associated with river blindness. Soluble extracts of O. volvulus, a filarial species that contains the endosymbiont bacteria Wolbachia or Acanthocheilonema viteae (a nematode not naturally infected with the bacteria) were injected into mouse corneas. Inflammatory responses and corneal changes were measured. We demonstrated a major role for endosymbiont Wolbachia bacteria and Toll-like receptor 4 (TLR4) in the pathogenesis of ocular onchocerciasis.}, }
@article {pmid14729693, year = {2004}, author = {Schmitz-Esser, S and Linka, N and Collingro, A and Beier, CL and Neuhaus, HE and Wagner, M and Horn, M}, title = {ATP/ADP translocases: a common feature of obligate intracellular amoebal symbionts related to Chlamydiae and Rickettsiae.}, journal = {Journal of bacteriology}, volume = {186}, number = {3}, pages = {683-691}, pmid = {14729693}, issn = {0021-9193}, mesh = {Acanthamoeba/*enzymology ; Adenosine Diphosphate/metabolism ; Adenosine Triphosphate/metabolism ; Animals ; Chlamydia/*enzymology ; Mitochondrial ADP, ATP Translocases/*genetics ; Phylogeny ; Rickettsia/*enzymology ; *Symbiosis ; }, abstract = {ATP/ADP translocases catalyze the highly specific transport of ATP across a membrane in an exchange mode with ADP. Such unique transport proteins are employed by plant plastids and have among the prokaryotes so far only been identified in few obligate intracellular bacteria belonging to the Chlamydiales and the Rickettsiales. In this study, 12 phylogenetically diverse bacterial endosymbionts of free-living amoebae and paramecia were screened for the presence of genes encoding ATP/ADP transport proteins. The occurrence of ATP/ADP translocase genes was found to be restricted to endosymbionts related to rickettsiae and chlamydiae. We showed that the ATP/ADP transport protein of the Parachlamydia-related endosymbiont of Acanthamoeba sp. strain UWE25, a recently identified relative of the important human pathogens Chlamydia trachomatis and Chlamydophila pneumoniae, is functional when expressed in the heterologous host Escherichia coli and demonstrated the presence of transcripts during the chlamydial developmental cycle. These findings indicate that the interaction between Parachlamydia-related endosymbionts and their amoeba hosts concerns energy parasitism similar to the interaction between pathogenic chlamydiae and their human host cells. Phylogenetic analysis of all known ATP/ADP translocases indicated that the genes encoding ATP/ADP translocases originated from a chlamydial ancestor and were, after an ancient gene duplication, transferred horizontally to rickettsiae and plants.}, }
@article {pmid14728775, year = {2003}, author = {Koga, R and Tsuchida, T and Fukatsu, T}, title = {Changing partners in an obligate symbiosis: a facultative endosymbiont can compensate for loss of the essential endosymbiont Buchnera in an aphid.}, journal = {Proceedings. Biological sciences}, volume = {270}, number = {1533}, pages = {2543-2550}, pmid = {14728775}, issn = {0962-8452}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; *Biological Evolution ; Buchnera/*physiology ; DNA Primers ; Ecosystem ; Gammaproteobacteria/*genetics/*physiology ; In Situ Hybridization ; Molecular Sequence Data ; Population Dynamics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Almost all aphids harbour an endosymbiotic bacterium, Buchnera aphidicola, in bacteriocytes. Buchnera synthesizes essential nutrients and supports growth and reproduction of the host. Over the long history of endosymbiosis, many essential genes have been lost from the Buchnera genome, resulting in drastic genome reduction and the inability to live outside the host cells. In turn, when deprived of Buchnera, the host aphid suffers retarded growth and sterility. Buchnera and the host aphid are often referred to as highly integrated almost inseparable mutualistic partners. However, we discovered that, even after complete elimination of Buchnera, infection with a facultative endosymbiotic gamma-proteobacterium called pea aphid secondary symbiont (PASS) enabled survival and reproduction of the pea aphid. In the Buchnera-free aphid, PASS infected the cytoplasms of bacteriocytes that normally harbour Buchnera, establishing a novel endosymbiotic system. These results indicate that PASS can compensate for the essential role of Buchnera by physiologically and cytologically taking over the symbiotic niche. By contrast, PASS negatively affected the growth and reproduction of normal host aphids by suppressing the essential symbiont Buchnera. These findings illuminate complex symbiont-symbiont and host-symbiont interactions in an endosymbiotic system, and suggest a possible evolutionary route to novel obligate endosymbiosis by way of facultative endosymbiotic associations.}, }
@article {pmid14714667, year = {2003}, author = {Goddard, J and Sumner, JW and Nicholson, WL and Paddock, CD and Shen, J and Piesman, J}, title = {Survey of ticks collected in Mississippi for Rickettsia, Ehrlichia, and Borrelia species.}, journal = {Journal of vector ecology : journal of the Society for Vector Ecology}, volume = {28}, number = {2}, pages = {184-189}, pmid = {14714667}, issn = {1081-1710}, mesh = {Animals ; Borrelia/genetics/*isolation &amp; purification ; DNA, Bacterial/analysis ; DNA, Protozoan/analysis ; Data Collection ; Deer ; Dogs ; Ehrlichia chaffeensis/genetics/*isolation &amp; purification ; Humans ; Mississippi ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S ; Rickettsia/genetics/*isolation &amp; purification ; Ticks/*microbiology ; }, abstract = {From November 1999 through October 2000, we tested ticks collected from vegetation as well as from deer, dogs, and humans for spotted fever group (SFG) rickettsiae, Ehrlichia chaffeensis, and Borrelia spp. spirochetes. A total of 149 adult ticks representing four species was collected from 11 collection sites from southwestern to northern Mississippi. Amblyomma americanum was most commonly collected (n=68), followed by Ixodes scapularis (n=53). The bird tick, Ixodes brunneus (usually rare), was the third most commonly collected tick (n=17). Eleven Dermacentor variabilis were also collected. Ticks were cut longitudinally to make smears on three microscope slides. The remaining body parts were frozen at -65 degrees C for additional testing. Tick smears were stained by direct immunofluorescence assays (DFA) for Rickettsia spp. and Borrelia spp., while indirect immunofluorescence assays (IFA) were used for Ehrlichia spp. The corresponding tick for each positive smear was evaluated using PCR analysis. None of the 149 ticks tested was DFA positive for Borrelia spp. However, smears of 30 (20%) and 32 (22%) ticks reacted with anti-E. chaffeensis sera and anti-R. rickettsii conjugate (known to react with several members of the spotted fever group), respectively. None of the ticks staining with the IFA for Ehrlichia was positive for E. chaffeensis using PCR. However, 23 (72%) of 32 FA-positive ticks for SFG rickettsiae yielded amplicons of the appropriate size when tested using a PCR assay for SFG rickettsiae, corresponding to an overall infection rate with SFG rickettsiae among the collected ticks of 15%. Smears of 12 (71%) of 17 I. brunneus revealed abundant bacilliform bacteria. PCR amplification of DNA from a single I. brunneus containing these bacteria was performed using universal primers for the 16S rRNA gene as well as Borrelia-specific primers. The predominant sequence obtained using the universal primers did not match any sequence in GenBank, but it showed 91% identity with an endosymbiont of Acanthoamoeba. Other sequences represented in the top 50 Basic Local Alignment Search (BLAST) scores were primarily from soil bacteria, although some similarity to several Anaplasma species and Ehrlichia risticii was indicated. The significance of this finding remains undetermined.}, }
@article {pmid14711652, year = {2004}, author = {Riegler, M and Charlat, S and Stauffer, C and Merçot, H}, title = {Wolbachia transfer from Rhagoletis cerasi to Drosophila simulans: investigating the outcomes of host-symbiont coevolution.}, journal = {Applied and environmental microbiology}, volume = {70}, number = {1}, pages = {273-279}, pmid = {14711652}, issn = {0099-2240}, mesh = {Animals ; *Biological Evolution ; Crosses, Genetic ; Drosophila/*microbiology/physiology ; Drosophila Proteins ; Female ; Fushi Tarazu Transcription Factors ; Genes, rRNA ; Homeodomain Proteins/genetics ; Male ; Molecular Sequence Data ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; Tephritidae/*microbiology/physiology ; Wolbachia/genetics/*physiology ; }, abstract = {Wolbachia is an endosymbiont of diverse arthropod lineages that can induce various alterations of host reproduction for its own benefice. Cytoplasmic incompatibility (CI) is the most common phenomenon, which results in embryonic lethality when males that bear Wolbachia are mated with females that do not. In the cherry fruit fly, Rhagoletis cerasi, Wolbachia seems to be responsible for previously reported patterns of incompatibility between populations. Here we report on the artificial transfer of two Wolbachia variants (wCer1 and wCer2) from R. cerasi into Drosophila simulans, which was performed with two major goals in mind: first, to isolate wCer1 from wCer2 in order to individually test their respective abilities to induce CI in the new host; and, second, to test the theoretical prediction that recent Wolbachia-host associations should be characterized by high levels of CI, fitness costs to the new host, and inefficient transmission from mothers to offspring. wCer1 was unable to develop in the new host, resulting in its rapid loss after successful injection, while wCer2 was established in the new host. Transmission rates of wCer2 were low, and the infection showed negative fitness effects, consistent with our prediction, but CI levels were unexpectedly lower in the new host. Based on these parameter estimates, neither wCer1 nor wCer2 could be naturally maintained in D. simulans. The experiment thus suggests that natural Wolbachia transfer between species might be restricted by many factors, should the ecological barriers be bypassed.}, }
@article {pmid14709722, year = {2004}, author = {Jeon, TJ and Jeon, KW}, title = {Gene switching in Amoeba proteus caused by endosymbiotic bacteria.}, journal = {Journal of cell science}, volume = {117}, number = {Pt 4}, pages = {535-543}, doi = {10.1242/jcs.00894}, pmid = {14709722}, issn = {0021-9533}, mesh = {Amino Acid Sequence ; Amoeba/enzymology/*genetics/*microbiology ; Animals ; Bacteria/*metabolism ; Cloning, Molecular ; Gene Expression Regulation, Enzymologic/*physiology ; *Genes, Protozoan ; Methionine Adenosyltransferase/chemistry/genetics/metabolism ; Molecular Sequence Data ; S-Adenosylmethionine/metabolism/pharmacokinetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis/*genetics ; }, abstract = {The expression of genes for S-adenosylmethionine synthetase (SAMS), which catalyzes the synthesis of S-adenosylmethionine (AdoMet), a major methyl donor in cells, was studied in symbiont-free (D) and symbiont-bearing (xD) amoeba strains to determine the effect of bacterial endosymbionts. The symbionts suppressed the expression of the gene in host xD amoebae, but amoebae still exhibited about half the enzyme activity found in symbiont-free D amoebae. The study was aimed at elucidating mechanisms of the suppression of the amoeba's gene and determining the alternative source for the gene product. Unexpectedly, we found a second sams (sams2) gene in amoebae, which encoded 390 amino acids. Results of experiments measuring SAMS activities and amounts of AdoMet in D and xD amoebae showed that the half SAMS activity found in xD amoebae came from the amoeba's SAMS2 and not from their endosymbionts. The expression of amoeba sams genes was switched from sams1 to sams2 as a result of infection with X-bacteria, raising the possibility that the switch in the expression of sams genes by bacteria plays a role in the development of symbiosis and the host-pathogen interactions. This is the first report showing such a switch in the expression of host sams genes by infecting bacteria.}, }
@article {pmid14706648, year = {2004}, author = {Suzuki, T and Hashimoto, T and Yabu, Y and Kido, Y and Sakamoto, K and Nihei, C and Hato, M and Suzuki, S and Amano, Y and Nagai, K and Hosokawa, T and Minagawa, N and Ohta, N and Kita, K}, title = {Direct evidence for cyanide-insensitive quinol oxidase (alternative oxidase) in apicomplexan parasite Cryptosporidium parvum: phylogenetic and therapeutic implications.}, journal = {Biochemical and biophysical research communications}, volume = {313}, number = {4}, pages = {1044-1052}, doi = {10.1016/j.bbrc.2003.12.038}, pmid = {14706648}, issn = {0006-291X}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; Cryptosporidiosis/drug therapy ; Cryptosporidium parvum/drug effects/*enzymology/genetics ; DNA, Protozoan/genetics ; Enzyme Inhibitors/pharmacology ; Humans ; Mitochondria/enzymology ; Molecular Sequence Data ; Oxidoreductases/antagonists &amp; inhibitors/chemistry/genetics/*metabolism ; Phylogeny ; Recombinant Proteins/antagonists &amp; inhibitors/chemistry/genetics/metabolism ; Sequence Homology, Amino Acid ; Sesquiterpenes/pharmacology ; }, abstract = {Cryptosporidium parvum is a parasitic protozoan that causes the diarrheal disease cryptosporidiosis, for which no satisfactory chemotherapy is currently available. Although the presence of mitochondria in this parasite has been suggested, its respiratory system is poorly understood due to difficulties in performing biochemical analyses. In order to better understand the respiratory chain of C. parvum, we surveyed its genomic DNA database in GenBank and identified a partial sequence encoding cyanide-insensitive alternative oxidase (AOX). Based on this sequence, we cloned C. parvum AOX (CpAOX) cDNA from the phylum apicomplexa for the first time. The deduced amino acid sequence (335 a.a.) of CpAOX contains diiron coordination motifs (-E-, -EXXH-) that are conserved among AOXs. Phylogenetic analysis suggested that CpAOX is a mitochondrial-type AOX, possibly derived from mitochondrial endosymbiont gene transfer. The recombinant enzyme expressed in Escherichia coli showed quinol oxidase activity. This activity was insensitive to cyanide and highly sensitive to ascofuranone, a specific inhibitor of trypanosome AOX.}, }
@article {pmid14681369, year = {2004}, author = {Gueneau de Novoa, P and Williams, KP}, title = {The tmRNA website: reductive evolution of tmRNA in plastids and other endosymbionts.}, journal = {Nucleic acids research}, volume = {32}, number = {Database issue}, pages = {D104-8}, pmid = {14681369}, issn = {1362-4962}, mesh = {Base Sequence ; Computational Biology ; *Databases, Nucleic Acid ; *Evolution, Molecular ; *Internet ; Molecular Sequence Data ; Nucleic Acid Conformation ; Plastids/*genetics ; RNA, Bacterial/chemistry/*genetics ; RNA, Plant/chemistry/*genetics ; Symbiosis/*genetics ; }, abstract = {tmRNA combines tRNA- and mRNA-like properties and ameliorates problems arising from stalled ribosomes. Research on the mechanism, structure and biology of tmRNA is served by the tmRNA website (http://www.indiana.edu/~ tmrna), a collection of sequences, alignments, secondary structures and other information. Because many of these sequences are not in GenBank, a BLAST server has been added; another new feature is an abbreviated alignment for the tRNA-like domain only. Many tmRNA sequences from plastids have been added, five found in public sequence data and another 10 generated by direct sequencing; detection in early-branching members of the green plastid lineage brings coverage to all three primary plastid lineages. The new sequences include the shortest known tmRNA sequence. While bacterial tmRNAs usually have a lone pseudoknot upstream of the mRNA segment and a string of three or four pseudoknots downstream, plastid tmRNAs collectively show loss of pseudoknots at both postions. The pseudoknot-string region is also too short to contain the usual pseudoknot number in another new entry, the tmRNA sequence from a bacterial endosymbiont of insect cells, Tremblaya princeps. Pseudoknots may optimize tmRNA function in free-living bacteria, yet become dispensible when the endosymbiotic lifestyle relaxes selective pressure for fast growth.}, }
@article {pmid14662876, year = {2003}, author = {Babu, S and Nutman, TB}, title = {Proinflammatory cytokines dominate the early immune response to filarial parasites.}, journal = {Journal of immunology (Baltimore, Md. : 1950)}, volume = {171}, number = {12}, pages = {6723-6732}, doi = {10.4049/jimmunol.171.12.6723}, pmid = {14662876}, issn = {0022-1767}, mesh = {Animals ; Antigen-Presenting Cells/immunology/metabolism/parasitology ; Antigens, Helminth/immunology ; Brugia malayi/growth &amp; development/*immunology ; CD4-Positive T-Lymphocytes/cytology/immunology/metabolism/parasitology ; CD8-Positive T-Lymphocytes/cytology/immunology/metabolism/parasitology ; Cell Communication/immunology ; Cells, Cultured ; Cytokines/*biosynthesis ; Flow Cytometry ; Host-Parasite Interactions/immunology ; Humans ; Inflammation Mediators/*metabolism ; Lipopolysaccharides/pharmacology ; Lymphocyte Activation/immunology ; Reverse Transcriptase Polymerase Chain Reaction ; T-Lymphocytes/cytology/*immunology/*metabolism/parasitology ; Th1 Cells/cytology/immunology/metabolism/parasitology ; }, abstract = {Although the early human immune response to the infective-stage larvae (L3) of Brugia malayi has not been well-characterized in vivo (because of the inability to determine the precise time of infection), the consensus has been that it must involve a predominant Th2 environment. We have set up an in vitro system to study this early immune response by culturing PBMC from unexposed individuals with live L3 of B. malayi. After 24 h of culture, T cell responses were examined by flow cytometry and by quantitative real-time RT-PCR for multiple cytokines. T cells were activated early following exposure to L3 as indicated by up-regulation of surface markers CD69 and CD71. The frequency of T cells expressing proinflammatory Th1 cytokines (IFN-gamma, TNF-alpha, GM-CSF, IL-1alpha, and IL-8) but not Th2 cytokines (IL-4, IL-5, IL-6, IL-10, and IL-13) was significantly increased in response to L3. This T cell response occurred in both the CD4 and CD8 T cell compartment and was restricted to the effector/memory pool (CD45RO(+)). This T cell response was not due to LPS activity from the parasite or from its endosymbiont, Wolbachia; moreover, it required the presence of APC as well as direct contact with live L3. Real-time RT-PCR analysis of multiple cytokines in the T cells confirmed the increased expression of proinflammatory Th1 cytokines. Up-regulation of these cytokines suggests that the primary immune response to the live infective stage of the parasite is not predominantly Th2 in nature but rather dominated by a proinflammatory response.}, }
@article {pmid14651884, year = {2003}, author = {Komnenou, A and Egyed, Z and Sréter, T and Eberhard, ML}, title = {Canine onchocercosis in Greece: report of further 20 cases and molecular characterization of the parasite and its Wolbachia endosymbiont.}, journal = {Veterinary parasitology}, volume = {118}, number = {1-2}, pages = {151-155}, doi = {10.1016/j.vetpar.2003.09.007}, pmid = {14651884}, issn = {0304-4017}, mesh = {Animals ; DNA, Bacterial/*analysis ; Dog Diseases/microbiology/*parasitology/surgery ; Dogs ; Greece ; Onchocerca/isolation &amp; purification/*microbiology ; Onchocerciasis, Ocular/microbiology/parasitology/surgery/*veterinary ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; Symbiosis ; Wolbachia/classification/*isolation &amp; purification ; }, abstract = {Recently, sporadic cases of subconjunctival Onchocerca infection have been reported in dogs in Greece and Hungary. Herein we report further cases from Greece and the results of the molecular analysis of Onchocerca sp. removed from Greek dogs and its Wolbachia endosymbionts. Twenty dogs of various breeds, 1-11 years of age with subconjunctival onchocercosis (4 cases each in right or left eye, 12 cases in both eyes) were presented having similar manifestations. Periorbital swelling, exophthalmos, lacrimation, discharge, photophobia, conjunctival congestion, corneal edema, protrusion of the nictitating membrane, and subconjunctival granuloma or cyst formation were the most important clinical signs. After surgical excision of the periocular masses containing the worms, all animals recovered fully from onchocercosis. Based on the similarities of the clinical picture of the Greek and Hungarian cases, the similar morphology of the Greek and Hungarian isolates, and the identical sequences of the cytochrome oxidase gene of the filarial parasites and that of the 16S ribosomal RNA gene from their Wolbachia endosymbionts, the Onchocerca sp. isolated from dogs in Greece and Hungary appears to belong to the same species.}, }
@article {pmid14641977, year = {2003}, author = {Benlarbi, M and Ready, PD}, title = {Host-specific Wolbachia strains in widespread populations of Phlebotomus perniciosus and P. papatasi (Diptera: Psychodidae), and prospects for driving genes into these vectors of Leishmania.}, journal = {Bulletin of entomological research}, volume = {93}, number = {5}, pages = {383-391}, doi = {10.1079/ber2003251}, pmid = {14641977}, issn = {0007-4853}, mesh = {Animals ; Disease Transmission, Infectious/veterinary ; Female ; *Gene Transfer Techniques ; Genetic Vectors ; Host-Parasite Interactions ; Infectious Disease Transmission, Vertical/veterinary ; Insect Vectors/*microbiology/parasitology ; Leishmaniasis/prevention &amp; control/*transmission ; Male ; Phlebotomus/*microbiology/parasitology ; Polymerase Chain Reaction/veterinary ; Reproduction ; Sex Factors ; Species Specificity ; Transgenes ; *Wolbachia/genetics/growth &amp; development ; }, abstract = {A single strain of Wolbachia (alpha-proteobacteria, Rickettsiales) was found in widespread geographical populations of each of two Phlebotomus species, within which there was no indication of 'infectious speciation'. The two strains were identified by sequencing a fragment of wsp (a major surface protein gene), amplified by polymerase chain reaction from DNA extracted from the body parts of individual sandflies. Infection rates were high in the males and females of both sandflies, but they were lower for the B-group wPrn strain of Wolbachia in Phlebotomus perniciosus Newstead (60.3% overall) than for the A-group wPap strain in P. papatasi (Scopoli) (81.7%). Infections were frequent in the thorax, where Leishmania develops infective forms, as well as in the abdomen, where Wolbachia must infect the reproductive tissues to ensure its vertical transmission. These findings were related to knowledge of the population biology of Wolbachia in other insects, leading to the conclusion that this endosymbiont could be useful for driving transgenes through wild populations of both sandflies. This will require characterizing the cytoplasmic incompatibility phenotypes of Wolbachia-sandfly combinations, as well as estimating for them the incidence of paternal transmission and the fidelity of maternal transmission. Paternal transmission is one explanation for finding a single Wolbachia strain associated with all mitochondrial haplotypes and lineages of each sandfly species. However, this distribution pattern could also result from multiple horizontal transmissions or the failure of wsp to provide strain markers.}, }
@article {pmid14629360, year = {2003}, author = {Mouton, L and Henri, H and Bouletreau, M and Vavre, F}, title = {Strain-specific regulation of intracellular Wolbachia density in multiply infected insects.}, journal = {Molecular ecology}, volume = {12}, number = {12}, pages = {3459-3465}, doi = {10.1046/j.1365-294x.2003.02015.x}, pmid = {14629360}, issn = {0962-1083}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; DNA Primers ; Electrophoresis, Agar Gel ; *Genetic Variation ; Population Density ; Species Specificity ; *Symbiosis ; Wasps/*microbiology ; Wolbachia/*genetics/physiology ; }, abstract = {Vertically transmitted symbionts suffer a severe reduction in numbers when they pass through host generations, resulting in genetic homogeneity or even clonality of their populations. Wolbachia endosymbionts that induce cytoplasmic incompatibility in their hosts depart from this rule, because cytoplasmic incompatibility actively maintains multiple infection within hosts. Hosts and symbionts are thus probably under peculiar selective pressures that must shape the way intracellular bacterial populations are regulated. We studied the density and location of Wolbachia within adult Leptopilina heterotoma, a haplodiploid wasp that is parasitic on Drosophila and that is naturally infected with three Wolbachia strains, but for which we also obtained one simply infected and two doubly infected lines. Comparison of these four lines by quantitative polymerase chain reaction using a real-time detection system showed that total Wolbachia density varies according to the infection status of individuals, while the specific density of each Wolbachia strain remains constant regardless of the presence of other strains. This suggests that Wolbachia strains do not compete with one another within the same host individual, and that a strain-specific regulatory mechanism is operating. We discuss the regulatory mechanisms that are involved, and how this process might have evolved as a response to selective pressures acting on both partners.}, }
@article {pmid14622983, year = {2003}, author = {Emelyanov, VV}, title = {Common evolutionary origin of mitochondrial and rickettsial respiratory chains.}, journal = {Archives of biochemistry and biophysics}, volume = {420}, number = {1}, pages = {130-141}, doi = {10.1016/j.abb.2003.09.031}, pmid = {14622983}, issn = {0003-9861}, mesh = {Alphaproteobacteria/enzymology/genetics ; Amino Acid Sequence ; Biological Evolution ; Cell Respiration/*genetics ; Coxiellaceae/*enzymology/*genetics ; Electron Transport Chain Complex Proteins/classification/*genetics ; Electron Transport Complex I ; Electron Transport Complex II ; Electron Transport Complex III ; *Evolution, Molecular ; Gene Expression Profiling/methods ; Gene Expression Regulation, Enzymologic/genetics ; Mitochondria/*enzymology/*genetics ; Molecular Sequence Data ; *Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; }, abstract = {Comprehensive phylogenetic analysis of the subunits of respiratory chain was carried out using a variety of mitochondrial and bacterial sequences including those from all unfinished alpha-proteobacterial genomes known to date. Maximum likelihood, neighbor-joining, and maximum parsimony consensus trees, based on four proton-translocating complexes, placed mitochondria as a sister group to the order Rickettsiales of obligate endosymbiotic bacteria to the exclusion of free-living alpha-proteobacteria. Thus, phylogenetic relationship of most eukaryotic respiratory enzymes conforms to canonical pattern of mitochondrial ancestry, prior established in analyses of ribosomal RNAs, which are encoded by residual mitochondrial genomes. These data suggest that mitochondria may have derived from a reduced intracellular bacterium and that respiration may be the only evolutionary novelty brought into eukaryotes by mitochondrial endosymbiont.}, }
@article {pmid14620780, year = {2003}, author = {von Bomhard, W and Polkinghorne, A and Lu, ZH and Vaughan, L and Vögtlin, A and Zimmermann, DR and Spiess, B and Pospischil, A}, title = {Detection of novel chlamydiae in cats with ocular disease.}, journal = {American journal of veterinary research}, volume = {64}, number = {11}, pages = {1421-1428}, doi = {10.2460/ajvr.2003.64.1421}, pmid = {14620780}, issn = {0002-9645}, mesh = {Animals ; Base Sequence ; Cat Diseases/*diagnosis/microbiology/pathology ; Cats ; Chlamydia/classification/genetics/*isolation &amp; purification ; Chlamydia Infections/diagnosis/pathology/*veterinary ; Conjunctivitis, Inclusion/diagnosis/pathology/*veterinary ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA, Bacterial/genetics/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics/isolation &amp; purification ; RNA, Ribosomal, 23S/genetics/isolation &amp; purification ; Sequence Alignment ; Sequence Homology, Nucleic Acid ; }, abstract = {OBJECTIVE: To detect and characterize the full range of chlamydial infections in cats with ocular disease by use of polymerase chain reaction (PCR) assays, cytologic examination, immunohistochemical analysis, and evaluation of clinical information including status for feline herpesvirus-1 (FeHV-1).<br><br>SAMPLE POPULATION: DNA extracted from 226 conjunctival samples obtained from cats with clinically diagnosed keratitis or conjunctivitis and 30 conjunctival samples from healthy cats.<br><br>PROCEDURE: PCR assays for the 16S rRNA gene specific for the order Chlamydiales and a new Chlamydophila felis (formerly Chlamydia psittaci) species-specific 23S rRNA gene were performed. Seventy-four conjunctival samples were prepared with Romanowsky-type stain, grouped on the basis of inflammatory pattern, and screened for chlamydial inclusions by use of immunohistochemical analysis. Clinical information and FeHV-1 status were recorded.<br><br>RESULTS: 26 (12%) specimens had positive results for the only known feline chlamydial pathogen, C felis. Surprisingly, an additional 88 (39%) were positive for non-C felis chlamydial DNA. Identification of non-C felis chlamydial DNA by direct sequencing revealed 16S rRNA gene sequences that were 99% homologous to the sequence for Neochlamydia hartmannellae, an amebic endosymbiont. Chlamydial prevalence was significantly higher in cats with ocular disease.<br><br>Application of a broad-range detection method resulted in identification of a new agent associated with ocular disease in cats. Finding chlamydia-like agents such as N hartmannellae in coinfections with their obligate amebic host, Hartmannella vermiformis, raises questions about the potential role of these microorganisms in causation or exacerbation of ocular disease in cats.}, }
@article {pmid14614504, year = {2003}, author = {Tovar, J and León-Avila, G and Sánchez, LB and Sutak, R and Tachezy, J and van der Giezen, M and Hernández, M and Müller, M and Lucocq, JM}, title = {Mitochondrial remnant organelles of Giardia function in iron-sulphur protein maturation.}, journal = {Nature}, volume = {426}, number = {6963}, pages = {172-176}, doi = {10.1038/nature01945}, pmid = {14614504}, issn = {1476-4687}, mesh = {Amino Acid Sequence ; Animals ; Biological Evolution ; Cloning, Molecular ; Fluorescent Antibody Technique ; Genes, Protozoan/genetics ; Giardia/*cytology/genetics/*metabolism ; Iron-Sulfur Proteins/*biosynthesis/metabolism ; Microscopy, Immunoelectron ; Mitochondria/*metabolism ; Molecular Sequence Data ; Protein Transport ; Protozoan Proteins/*biosynthesis/metabolism ; Symbiosis ; }, abstract = {Giardia intestinalis (syn. lamblia) is one of the most widespread intestinal protozoan pathogens worldwide, causing hundreds of thousands of cases of diarrhoea each year. Giardia is a member of the diplomonads, often described as an ancient protist group whose primitive nature is suggested by the lack of typical eukaryotic organelles (for example, mitochondria, peroxisomes), the presence of a poorly developed endomembrane system and by their early branching in a number of gene phylogenies. The discovery of nuclear genes of putative mitochondrial ancestry in Giardia and the recent identification of mitochondrial remnant organelles in amitochondrial protists such as Entamoeba histolytica and Trachipleistophora hominis suggest that the eukaryotic amitochondrial state is not a primitive condition but is rather the result of reductive evolution. Using an in vitro protein reconstitution assay and specific antibodies against IscS and IscU--two mitochondrial marker proteins involved in iron-sulphur cluster biosynthesis--here we demonstrate that Giardia contains mitochondrial remnant organelles (mitosomes) bounded by double membranes that function in iron-sulphur protein maturation. Our results indicate that Giardia is not primitively amitochondrial and that it has retained a functional organelle derived from the original mitochondrial endosymbiont.}, }
@article {pmid14613499, year = {2003}, author = {Hannaert, V and Bringaud, F and Opperdoes, FR and Michels, PA}, title = {Evolution of energy metabolism and its compartmentation in Kinetoplastida.}, journal = {Kinetoplastid biology and disease}, volume = {2}, number = {1}, pages = {11}, pmid = {14613499}, issn = {1475-9292}, abstract = {Kinetoplastida are protozoan organisms that probably diverged early in evolution from other eukaryotes. They are characterized by a number of unique features with respect to their energy and carbohydrate metabolism. These organisms possess peculiar peroxisomes, called glycosomes, which play a central role in this metabolism; the organelles harbour enzymes of several catabolic and anabolic routes, including major parts of the glycolytic and pentosephosphate pathways. The kinetoplastid mitochondrion is also unusual with regard to both its structural and functional properties.In this review, we describe the unique compartmentation of metabolism in Kinetoplastida and the metabolic properties resulting from this compartmentation. We discuss the evidence for our recently proposed hypothesis that a common ancestor of Kinetoplastida and Euglenida acquired a photosynthetic alga as an endosymbiont, contrary to the earlier notion that this event occurred at a later stage of evolution, in the Euglenida lineage alone. The endosymbiont was subsequently lost from the kinetoplastid lineage but, during that process, some of its pathways of energy and carbohydrate metabolism were sequestered in the kinetoplastid peroxisomes, which consequently became glycosomes. The evolution of the kinetoplastid glycosomes and the possible selective advantages of these organelles for Kinetoplastida are discussed. We propose that the possession of glycosomes provided metabolic flexibility that has been important for the organisms to adapt easily to changing environmental conditions. It is likely that metabolic flexibility has been an important selective advantage for many kinetoplastid species during their evolution into the highly successful parasites today found in many divergent taxonomic groups.Also addressed is the evolution of the kinetoplastid mitochondrion, from a supposedly pluripotent organelle, attributed to a single endosymbiotic event that resulted in all mitochondria and hydrogenosomes of extant eukaryotes. Furthermore, indications are presented that Kinetoplastida may have acquired other enzymes of energy and carbohydrate metabolism by various lateral gene transfer events different from those that involved the algal- and alpha-proteobacterial-like endosymbionts responsible for the respective formation of the glycosomes and mitochondria.}, }
@article {pmid14602646, year = {2003}, author = {Rio, RV and Lefevre, C and Heddi, A and Aksoy, S}, title = {Comparative genomics of insect-symbiotic bacteria: influence of host environment on microbial genome composition.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {11}, pages = {6825-6832}, pmid = {14602646}, issn = {0099-2240}, support = {T32 AI007404/AI/NIAID NIH HHS/United States ; AI-34033/AI/NIAID NIH HHS/United States ; T01/CCT122306-01/CC/ODCDC CDC HHS/United States ; T32AI07404/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Coleoptera/*microbiology ; DNA, Bacterial/genetics ; Ecosystem ; Escherichia coli/genetics ; Gammaproteobacteria/*genetics/growth &amp; development/metabolism ; *Genome, Bacterial ; Genomics/methods ; Oligonucleotide Array Sequence Analysis/*methods ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Commensal symbionts, thought to be intermediary amid obligate mutualists and facultative parasites, offer insight into forces driving the evolutionary transition into mutualism. Using macroarrays developed for a close relative, Escherichia coli, we utilized a heterologous array hybridization approach to infer the genomic compositions of a clade of bacteria that have recently established symbiotic associations: Sodalis glossinidius with the tsetse fly (Diptera, Glossina spp.) and Sitophilus oryzae primary endosymbiont (SOPE) with the rice weevil (Coleoptera, Sitophilus oryzae). Functional biologies within their hosts currently reflect different forms of symbiotic associations. Their hosts, members of distant insect taxa, occupy distinct ecological niches and have evolved to survive on restricted diets of blood for tsetse and cereal for the rice weevil. Comparison of genome contents between the two microbes indicates statistically significant differences in the retention of genes involved in carbon compound catabolism, energy metabolism, fatty acid metabolism, and transport. The greatest reductions have occurred in carbon catabolism, membrane proteins, and cell structure-related genes for Sodalis and in genes involved in cellular processes (i.e., adaptations towards cellular conditions) for SOPE. Modifications in metabolic pathways, in the form of functional losses complementing particularities in host physiology and ecology, may have occurred upon initial entry from a free-living to a symbiotic state. It is possible that these adaptations, streamlining genomes, act to make a free-living state no longer feasible for the harnessed microbe.}, }
@article {pmid14602641, year = {2003}, author = {Won, YJ and Hallam, SJ and O'Mullan, GD and Pan, IL and Buck, KR and Vrijenhoek, RC}, title = {Environmental acquisition of thiotrophic endosymbionts by deep-sea mussels of the genus bathymodiolus.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {11}, pages = {6785-6792}, pmid = {14602641}, issn = {0099-2240}, mesh = {Animals ; Atlantic Ocean ; Bacteria/classification/genetics/isolation &amp; purification ; DNA, Mitochondrial/genetics ; DNA, Ribosomal Spacer/analysis ; Endocytosis/*physiology ; Gills/cytology/*microbiology/ultrastructure ; Microscopy, Electron ; Molecular Sequence Data ; Mollusca/*microbiology ; Phylogeny ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Sequence Analysis, DNA ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Deep-sea Bathymodiolus mussels, depending on species and location, have the capacity to host sulfur-oxidizing (thiotrophic) and methanotrophic eubacteria in gill bacteriocytes, although little is known about the mussels' mode of symbiont acquisition. Previous studies of Bathymodiolus host and symbiont relationships have been based on collections of nonoverlapping species across wide-ranging geographic settings, creating an apparent model for vertical transmission. We present genetic and cytological evidence for the environmental acquisition of thiotrophic endosymbionts by vent mussels from the Mid-Atlantic Ridge. Open pit structures in cell membranes of the gill surface revealed likely sites for endocytosis of free-living bacteria. A population genetic analysis of the thiotrophic symbionts exploited a hybrid zone where two Bathymodiolus species intergrade. Northern Bathymodiolus azoricus and southern Bathymodiolus puteoserpentis possess species-specific DNA sequences that identify both their symbiont strains (internal transcribed spacer regions) and their mitochondria (ND4). However, the northern and southern symbiont-mitochondrial pairs were decoupled in the hybrid zone. Such decoupling of symbiont-mitochondrial pairs would not occur if the two elements were transmitted strictly vertically through the germ line. Taken together, these findings are consistent with an environmental source of thiotrophic symbionts in Bathymodiolus mussels, although an environmentally "leaky" system of vertical transmission could not be excluded.}, }
@article {pmid14597281, year = {2003}, author = {Bazzocchi, C and Genchi, C and Paltrinieri, S and Lecchi, C and Mortarino, M and Bandi, C}, title = {Immunological role of the endosymbionts of Dirofilaria immitis: the Wolbachia surface protein activates canine neutrophils with production of IL-8.}, journal = {Veterinary parasitology}, volume = {117}, number = {1-2}, pages = {73-83}, doi = {10.1016/j.vetpar.2003.07.013}, pmid = {14597281}, issn = {0304-4017}, mesh = {Animals ; Bacterial Outer Membrane Proteins/immunology ; Chemotaxis/immunology ; Dirofilaria/*microbiology ; Dirofilaria immitis/microbiology ; Dirofilariasis/parasitology ; Dog Diseases/parasitology ; Dogs ; Immunoglobulin G/biosynthesis ; Interleukin-8/biosynthesis ; Neutrophils/metabolism ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; *Symbiosis ; Wolbachia/*immunology ; }, abstract = {Filarial nematodes, including Dirofilaria immitis and D. repens, harbour intracellular bacteria belonging to the genus Wolbachia. These bacteria have been implicated in the pathogenesis of filarial diseases, possibly through their endotoxins. Recent studies have shown that a major surface protein of Wolbachia (WSP) induces a specific IgG response in hosts infected by D. immitis. WSP from the Wolbachia of D. immitis was produced in recombinant form. The purified protein was used in stimulation assays on canine neutrophils. The assays performed using a modified Boyden chamber showed that WSP stimulates neutrophil chemokinesis. In addition, RT-PCR revealed increased production of chemokine IL-8 by cells incubated with this protein. Neutrophils have been shown to play a major role in the pathogenesis of river blindness, and to accumulate in the nodules of onchocerciasis patients. In dogs infected by D. immitis, neutrophils accumulate in kidneys and in the wall of pulmonary arteries. As shown by our studies, Wolbachia could contribute to these inflammatory phenomena through its surface protein WSP, independently from its endotoxin component.}, }
@article {pmid14571386, year = {2002}, author = {Sato, N}, title = {Comparative analysis of the genomes of cyanobacteria and plants.}, journal = {Genome informatics. International Conference on Genome Informatics}, volume = {13}, number = {}, pages = {173-182}, pmid = {14571386}, issn = {0919-9454}, mesh = {Cyanobacteria/*genetics ; Genome, Bacterial ; Genome, Plant ; Phylogeny ; Plants/*genetics ; *Sequence Analysis, DNA ; Sequence Homology ; }, abstract = {Chloroplast genome originates from the genome of ancestral cyanobacterial endosymbiont. The comparison of the genomes of cyanobacteria and plants has been made possible by the advance in genome sequencing. I report here current results of our computational efforts to compare the genomes of cyanobacteria and plants and to trace the process of evolution of cyanobacteria, chloroplasts and plants. Cyanobacteria form a clearly defined monophyletic clade with reasonable level of diversity and are ideal for testing various approaches of genome comparison. Analysis of short sequence features such as genome signature was found to be useful in characterizing cyanobacterial genomes. Comparison of genome contents was performed by homology grouping of predicted protein coding sequences, rather than orthologue-based comparison, to minimize effects of multi-domain proteins and large protein families, both of which are important in cyanobacterial genomes. Comparison of the genomes of six species of cyanobacteria suggests that there are a number of species-specific additions of protein genes, and this information is useful in reconstructing phylogenetic relationship. The homology groups in cyanobacteria were used as a reference to compare plants and non-photosynthetic organisms. The results suggest that 238 groups that are common to all organisms analyzed may define a minimal set of gene groups. In addition, only 80 groups are identified as the gene groups that could not have been acquired by plants without cyanobacterial endosymbiosis. Further study is needed to identify plant genes of cyanobacterial origin.}, }
@article {pmid14568537, year = {2003}, author = {Leipe, DD and Koonin, EV and Aravind, L}, title = {Evolution and classification of P-loop kinases and related proteins.}, journal = {Journal of molecular biology}, volume = {333}, number = {4}, pages = {781-815}, doi = {10.1016/j.jmb.2003.08.040}, pmid = {14568537}, issn = {0022-2836}, mesh = {Amino Acid Sequence ; Animals ; Conserved Sequence ; Evolution, Molecular ; Humans ; Models, Molecular ; Molecular Sequence Data ; Phosphotransferases/chemistry/*classification/*genetics/metabolism ; Phylogeny ; Protein Folding ; Protein Structure, Secondary ; Sequence Alignment ; }, abstract = {Sequences and structures of all P-loop-fold proteins were compared with the aim of reconstructing the principal events in the evolution of P-loop-containing kinases. It is shown that kinases and some related proteins comprise a monophyletic assemblage within the P-loop NTPase fold. An evolutionary classification of these proteins was developed using standard phylogenetic methods, analysis of shared sequence and structural signatures, and similarity-based clustering. This analysis resulted in the identification of approximately 40 distinct protein families within the P-loop kinase class. Most of these enzymes phosphorylate nucleosides and nucleotides, as well as sugars, coenzyme precursors, adenosine 5'-phosphosulfate and polynucleotides. In addition, the class includes sulfotransferases, amide bond ligases, pyrimidine and dihydrofolate reductases, and several other families of enzymes that have acquired new catalytic capabilities distinct from the ancestral kinase reaction. Our reconstruction of the early history of the P-loop NTPase fold includes the initial split into the common ancestor of the kinase and the GTPase classes, and the common ancestor of ATPases. This was followed by the divergence of the kinases, which primarily phosphorylated nucleoside monophosphates (NMP), but could have had broader specificity. We provide evidence for the presence of at least two to four distinct P-loop kinases, including distinct forms specific for dNMP and rNMP, and related enzymes in the last universal common ancestor of all extant life forms. Subsequent evolution of kinases seems to have been dominated by the emergence of new bacterial and, to a lesser extent, archaeal families. Some of these enzymes retained their kinase activity but evolved new substrate specificities, whereas others acquired new activities, such as sulfate transfer and reduction. Eukaryotes appear to have acquired most of their kinases via horizontal gene transfer from Bacteria, partly from the mitochondrial and chloroplast endosymbionts and partly at later stages of evolution. A distinct superfamily of kinases, which we designated DxTN after its sequence signature, appears to have evolved in selfish replicons, such as bacteriophages, and was subsequently widely recruited by eukaryotes for multiple functions related to nucleic acid processing and general metabolism. In the course of this analysis, several previously undetected groups of predicted kinases were identified, including widespread archaeo-eukaryotic and archaeal families. The results could serve as a framework for systematic experimental characterization of new biochemical and biological functions of kinases.}, }
@article {pmid14563170, year = {2003}, author = {Talge, HK and Hallock, P}, title = {Ultrastructural responses in field-bleached and experimentally stressed Amphistegina gibbosa (Class Foraminifera).}, journal = {The Journal of eukaryotic microbiology}, volume = {50}, number = {5}, pages = {324-333}, doi = {10.1111/j.1550-7408.2003.tb00143.x}, pmid = {14563170}, issn = {1066-5234}, mesh = {Animals ; Ecosystem ; Eukaryota/physiology/*ultrastructure ; Florida ; Light/adverse effects ; Microscopy, Electron ; Symbiosis/physiology ; }, abstract = {Amphistegina are the most common foraminifers with algal endosymbionts found on reefs and carbonate shelves worldwide. Like zooxanthellate corals and other reef organisms with algal symbionts, Amphistegina respond to photoxidative stress by bleaching. This paper documents ultrastructural changes that occur during bleaching under field and laboratory conditions. Nine chambers from the outer whorl of each of 22 normal-appearing and 11 partly bleached specimens of Amphistegina gibbosa, which were collected from Conch Reef, Florida, USA, were examined using transmission electron microscopy. The condition and numbers of algal symbionts, as well as the cell area occupied by 10 other intracellular structures of the host, were quantified. Normal-appearing specimens averaged three times more viable symbionts and less than a fourth as many deteriorating symbionts as partly bleached specimens. Foraminifers experimentally exposed to visible light intensities > or = 13 micromole photon m(-2) s(-1) for 35 d were statistically similar to partly bleached field specimens in the number and condition of symbionts, and in chamber area occupied by the evaluated host structures. Exposure to 32 degrees C water temperature at 6-8 micromole photon m(-2) s(-1) for 28 d induced symbiont loss but did not degrade host endoplasm.}, }
@article {pmid14561077, year = {2004}, author = {Nwachuku, N and Gerba, CP}, title = {Health effects of Acanthamoeba spp. and its potential for waterborne transmission.}, journal = {Reviews of environmental contamination and toxicology}, volume = {180}, number = {}, pages = {93-131}, doi = {10.1007/0-387-21729-0_2}, pmid = {14561077}, issn = {0179-5953}, mesh = {Acanthamoeba/*pathogenicity ; Acanthamoeba Keratitis/*transmission ; Amebiasis/*transmission ; Animals ; Contact Lenses/microbiology ; Disinfection ; Humans ; Immunocompromised Host ; Manure ; Population Dynamics ; Risk Assessment ; Sewage ; Water Microbiology ; *Water Purification ; *Water Supply ; }, abstract = {Risk from Acanthamoeba keratitis is complex, depending upon the virulence of the particular strain, exposure, trauma, or other stress to the eye, and host immune response. Bacterial endosymbionts may also play a factor in the pathogenicity of Acanthamoeba. Which factor(s) may be the most important is not clear. The ability of the host to produce IgA antibodies in tears may be a significant factor. The immune response of the host is a significant risk factor for GAE infection. If so, then a certain subpopulation with an inability to produce IgA in the tears may be at greatest risk. There was no sufficient data on the occurrence or types of Acanthamoeba in tapwater in the U.S. Published work on amoebal presence in tapwater does not provide information on the type of treatment the water received or the level of residual chlorine. Assessment of the pathogenicity by cell culture and molecular methods of Acanthamoeba in tapwater would also be useful in the risk assessment process for drinking water. The possibility that Acanthamoeba spp. might serve as vectors for bacterial infections from water sources also should be explored. The bacterial endosymbionts include an interesting array of pathogens such as Vibrio cholerae and Legionella pneumophila, both of which are well recognized waterborne/water-based pathogens. Work is needed to determine if control of Acanthamoeba spp. is needed to control water-based pathogens in water supplies.}, }
@article {pmid14551917, year = {2003}, author = {Braendle, C and Miura, T and Bickel, R and Shingleton, AW and Kambhampati, S and Stern, DL}, title = {Developmental origin and evolution of bacteriocytes in the aphid-Buchnera symbiosis.}, journal = {PLoS biology}, volume = {1}, number = {1}, pages = {E21}, pmid = {14551917}, issn = {1545-7885}, mesh = {Animals ; Aphids/*metabolism ; Buchnera/*metabolism ; Cell Lineage ; Drosophila Proteins/biosynthesis ; Evolution, Molecular ; Female ; *Gene Expression Regulation, Bacterial ; Homeodomain Proteins/biosynthesis ; Male ; Microscopy, Fluorescence ; Models, Biological ; Parthenogenesis ; Species Specificity ; *Symbiosis ; Time Factors ; Transcription Factors/biosynthesis/metabolism ; }, abstract = {Symbiotic relationships between bacteria and insect hosts are common. Although the bacterial endosymbionts have been subjected to intense investigation, little is known of the host cells in which they reside, the bacteriocytes. We have studied the development and evolution of aphid bacteriocytes, the host cells that contain the endosymbiotic bacteria Buchnera aphidicola. We show that bacteriocytes of Acyrthosiphon pisum express several gene products (or their paralogues): Distal-less, Ultrabithorax/Abdominal-A, and Engrailed. Using these markers, we find that a subpopulation of the bacteriocytes is specified prior to the transmission of maternal bacteria to the embryo. In addition, we discovered that a second population of cells is recruited to the bacteriocyte fate later in development. We experimentally demonstrate that bacteriocyte induction and proliferation occur independently of B. aphidicola. Major features of bacteriocyte development, including the two-step recruitment of bacteriocytes, have been conserved in aphids for 80-150 million years. Furthermore, we have investigated two cases of evolutionary loss of bacterial symbionts: in one case, where novel extracellular, eukaryotic symbionts replaced the bacteria, the bacteriocyte is maintained; in another case, where symbionts are absent, the bacteriocytes are initiated but not maintained. The bacteriocyte represents an evolutionarily novel cell fate, which is developmentally determined independently of the bacteria. Three of five transcription factors we examined show novel expression patterns in bacteriocytes, suggesting that bacteriocytes may have evolved to express many additional transcription factors. The evolutionary transition to a symbiosis in which bacteria and an aphid cell form a functional unit, similar to the origin of plastids, has apparently involved extensive molecular adaptations on the part of the host cell.}, }
@article {pmid14535340, year = {2003}, author = {Dyková, I and Veverková, M and Fiala, I and Machácková, B and Pecková, H}, title = {Nuclearia pattersoni sp. n. (Filosea), a new species of amphizoic amoeba isolated from gills of roach (Rutilus rutilus), and its rickettsial endosymbiont.}, journal = {Folia parasitologica}, volume = {50}, number = {3}, pages = {161-170}, pmid = {14535340}, issn = {0015-5683}, mesh = {Amoeba/classification/genetics/*isolation &amp; purification/ultrastructure ; Animals ; Base Sequence ; Cyprinidae/*microbiology/*parasitology ; DNA/genetics ; DNA, Bacterial/genetics ; Gills/microbiology/parasitology ; Microscopy, Electron ; Phylogeny ; Rickettsia/classification/genetics/*isolation &amp; purification ; Symbiosis ; }, abstract = {A new species of amphizoic amoeba, Nuclearia pattersoni sp. n., isolated from gills of Rutilus rutilus L. is described. It is characterised by elongate flattened trophozoites of irregular shape. The longer dimension of their bodies is 13.2 (11.0-15.7) microm. Filopodia radiating mostly from the poles are 2 to 2.5 times longer than the body. The diameter of less frequently observed spherical trophozoites is 8.2-10.8 microm; their filopodia radiate to all directions. Cyst-like stages have shorter pseudopodia that arise from one pole only. The surface of locomotive forms from agar plate cultures has a thin amorphous glycocalyx, while most cells are covered by two layers of extracellular matrix. Mitochondria have flattened cristae, dictyosomes are located in the perinuclear zone. A conspicuous ultrastructural feature of the morphologically similar N. simplex, perinuclear striated band, is not present. Light microscopic and ultrastructural data are completed with the sequence of SSU rRNA gene and phylogenetic analysis including sequences of related taxa. The bacterial endosymbiont found in N. pattersoni type strain RR2G2 is assigned to the genus Rickettsia.}, }
@article {pmid14532089, year = {2003}, author = {Gros, O and Liberge, M and Heddi, A and Khatchadourian, C and Felbeck, H}, title = {Detection of the free-living forms of sulfide-oxidizing gill endosymbionts in the lucinid habitat (Thalassia testudinum environment).}, journal = {Applied and environmental microbiology}, volume = {69}, number = {10}, pages = {6264-6267}, pmid = {14532089}, issn = {0099-2240}, mesh = {Animals ; Bacteria/genetics/*growth &amp; development/isolation &amp; purification ; Geologic Sediments ; Gills/*microbiology ; Hydrocharitaceae/*growth &amp; development ; In Situ Hybridization, Fluorescence ; Mollusca/*microbiology ; Oxidation-Reduction ; Polymerase Chain Reaction ; Seawater ; Sulfides/*metabolism ; *Symbiosis ; }, abstract = {Target DNA from the uncultivable Codakia orbicularis endosymbiont was PCR amplified from sea-grass sediment. To confirm that such amplifications originated from intact bacterial cells rather than free DNA, whole-cell hybridization (fluorescence in situ hybridization technique) with the specific probe Symco2 was performed along with experimental infection of aposymbiotic juveniles placed in contact with the same sediment. Taken together, the data demonstrate that the sulfide-oxidizing gill endosymbiont of Codakia orbicularis is present in the environment as a free-living uncultivable form.}, }
@article {pmid14532065, year = {2003}, author = {Kikuchi, Y and Fukatsu, T}, title = {Diversity of Wolbachia endosymbionts in heteropteran bugs.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {10}, pages = {6082-6090}, pmid = {14532065}, issn = {0099-2240}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Cytoskeletal Proteins/genetics ; DNA, Bacterial/analysis ; *Genetic Variation ; Heteroptera/classification/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sequence Analysis, DNA ; *Symbiosis ; Wolbachia/*classification/genetics ; }, abstract = {An extensive survey of Wolbachia endosymbionts in Japanese terrestrial heteropteran bugs was performed by PCR detection with universal primers for wsp and ftsZ genes of Wolbachia, cloning of the PCR products, restriction fragment length polymorphism analysis of infecting Wolbachia types, and molecular phylogenetic characterization of all the detected Wolbachia strains. Of 134 heteropteran species from 19 families examined, Wolbachia infection was detected in 47 species from 13 families. From the 47 species, 59 Wolbachia strains were identified. Of the 59 strains, 16 and 43 were assigned to A group and B group in the Wolbachia phylogeny, respectively. The 47 species of Wolbachia-infected bugs were classified into 8 species with A infection, 28 species with B infection, 2 species with AA infection, 3 species with AB infection, 5 species with BB infection, and 1 species with ABB infection. Molecular phylogenetic analysis showed little congruence between Wolbachia phylogeny and host systematics, suggesting frequent horizontal transfers of Wolbachia in the evolutionary course of the Heteroptera. The phylogenetic analysis also revealed several novel lineages of Wolbachia. Based on statistical analyses of the multiple infections, we propose a hypothetical view that, in the heteropteran bugs, interactions between coinfecting Wolbachia strains are generally not intense and that Wolbachia coinfections have been established through a stochastic process probably depending on occasional horizontal transfers.}, }
@article {pmid14519197, year = {2003}, author = {Scharf, ME and Wu-Scharf, D and Pittendrigh, BR and Bennett, GW}, title = {Caste- and development-associated gene expression in a lower termite.}, journal = {Genome biology}, volume = {4}, number = {10}, pages = {R62}, pmid = {14519197}, issn = {1474-760X}, mesh = {Animals ; Cellulase/genetics ; Cytoskeleton/genetics ; Electron Transport/genetics ; Expressed Sequence Tags ; *Gene Expression Profiling ; *Gene Expression Regulation, Developmental ; Gene Library ; Genes, Insect/*genetics ; Isoptera/enzymology/*genetics/*growth &amp; development/physiology ; Molecular Sequence Data ; Muscles/metabolism ; Oligonucleotide Array Sequence Analysis ; RNA, Messenger/genetics/metabolism ; Signal Transduction/genetics ; Symbiosis/genetics ; Transcription Factors/genetics ; Transcription, Genetic ; }, abstract = {BACKGROUND: Social insects such as termites express dramatic polyphenism (the occurrence of multiple forms in a species on the basis of differential gene expression) both in association with caste differentiation and between castes after differentiation. We have used cDNA macroarrays to compare gene expression between polyphenic castes and intermediary developmental stages of the termite Reticulitermes flavipes.<br><br>RESULTS: We identified differentially expressed genes from nine ontogenic categories. Quantitative PCR was used to quantify precise differences in gene expression between castes and between intermediary developmental stages. We found worker and nymph-biased expression of transcripts encoding termite and endosymbiont cellulases; presoldier-biased expression of transcripts encoding the storage/hormone-binding protein vitellogenin; and soldier-biased expression of gene transcripts encoding two transcription/translation factors, two signal transduction factors and four cytoskeletal/muscle proteins. The two transcription/translation factors showed significant homology to the bicaudal and bric-a-brac developmental genes of Drosophila.<br><br>CONCLUSIONS: Our results show differential expression of regulatory, structural and enzyme-coding genes in association with termite castes and their developmental precursor stages. They also provide the first glimpse into how insect endosymbiont cellulase gene expression can vary in association with the caste of a host. These findings shed light on molecular processes associated with termite biology, polyphenism, caste differentiation and development and highlight potentially interesting variations in developmental themes between termites, other insects, and higher animals.}, }
@article {pmid14510513, year = {2003}, author = {Yamada, K and Yoshida, K}, title = {Microinjection of magnetic micro-beads instead of endosymbiotic chlorella into Paramecium bursaria and their behavior.}, journal = {Nucleic acids research. Supplement (2001)}, volume = {}, number = {3}, pages = {327-328}, doi = {10.1093/nass/3.1.327}, pmid = {14510513}, mesh = {Animals ; *Chlorella ; Magnetics ; Microinjections ; Paramecium/*microbiology ; *Symbiosis ; }, abstract = {Instead of zoochlorella endosymbionts, magnetic micro-beads (Dynabeads) was microinjected into P. bursaria white strain which can resultantly response to magnetism. The system may provide an interesting artificial endosymbiosis system.}, }
@article {pmid14508655, year = {2003}, author = {Kimura, H and Higashide, Y and Naganuma, T}, title = {Endosymbiotic microflora of the vestimentiferan tubeworm (Lamellibrachia sp.) from a bathyal cold seep.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {5}, number = {6}, pages = {593-603}, pmid = {14508655}, issn = {1436-2228}, mesh = {Animals ; Base Sequence ; DNA Primers ; *Environment ; Histological Techniques ; In Situ Hybridization ; Invertebrates/anatomy &amp; histology/*microbiology ; Molecular Sequence Data ; Oceans and Seas ; *Phylogeny ; Proteobacteria/*genetics ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; Species Specificity ; *Symbiosis ; }, abstract = {Gutless vestimentiferan tubeworms are known to harbor endosymbiotic bacteria in a specialized tissue, the trophosome, which consists of lobules. The endosymbionts of vestimentiferans inhabiting sulfide-rich hydrothermal vents are monospecific for their host. In contrast, previous studies suggest that vestimentiferas of methane-rich seeps may host multispecific symbionts. Phylogenetic analysis and dot-blot hybridization of 16S ribosomal RNA genes (16S rDNA) detected 4 operational taxonomic units (OTUs) in the trophosome of the vestimentifera Lamellibrachia species from a bathyal methane-seep. The OTUs were closely related to 16S rDNA of the species belonging to alpha -Proteobacteria (Sulfitobacter), beta- Proteobacteria (Janthinobacterium), and gamma -Proteobacteria (Acinetobacter and Pseudomonas). Localizations of the 4 OTUs within the trophosome were confirmed by in situ hybridization (ISH). ISH signals of the alpha-proteobacterial OTU were observed in the innermost zone of the trophosome lobules. In contrast, ISH signals of the beta- and gamma-proteobacterial OTUs were observed at the periphery of the lobules; however, whether they occur inside or outside the lobules remains unclear. These results support the possibility that the studied methane-seep tubeworm has a microflora composed of multispecific endosymbionts.}, }
@article {pmid14506854, year = {2003}, author = {Nirgianaki, A and Banks, GK and Frohlich, DR and Veneti, Z and Braig, HR and Miller, TA and Bedford, ID and Markham, PG and Savakis, C and Bourtzis, K}, title = {Wolbachia infections of the whitefly Bemisia tabaci.}, journal = {Current microbiology}, volume = {47}, number = {2}, pages = {93-101}, doi = {10.1007/s00284-002-3969-1}, pmid = {14506854}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Hemiptera/*microbiology ; Insecta/microbiology ; Lepidoptera/microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {We report the first systematic survey for the presence of Wolbachia endosymbionts in aphids and whiteflies, particularly different populations and biotypes of Bemisia tabaci. Additional agriculturally important species included were predator species, leafhoppers, and lepidopterans. We used a polymerase chain reaction (PCR)-based detection assay with ribosomal 16S rDNA and Wolbachia cell surface protein (wsp) gene primers. Wolbachia were detected in a number of whitefly populations and species, whitefly predators, and one leafhopper species; however, none of the aphid species tested were found infected. Single, double, and triple infections were detected in some of the B. tabaci populations. PCR and phylogenetic analysis of wsp gene sequences indicated that all Wolbachia strains found belong to group B. Topologies of the optimal tree derived by maximum likelihood (ML) and a ML tree in which Wolbachia sequences from B. tabaci are constrained to be monophyletic are significantly different. Our results indicate that there have been at least four independent Wolbachia infection events in B. tabaci. The importance of the presence of Wolbachia infections in B. tabaci is discussed.}, }
@article {pmid14502398, year = {2003}, author = {Kimura, H and Sato, M and Sasayama, Y and Naganuma, T}, title = {Molecular characterization and in situ localization of endosymbiotic 16S ribosomal RNA and RuBisCO genes in the pogonophoran tissue.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {5}, number = {3}, pages = {261-269}, pmid = {14502398}, issn = {1436-2228}, mesh = {Animals ; Base Sequence ; DNA Primers ; DNA, Ribosomal/genetics ; Gammaproteobacteria/genetics ; In Situ Hybridization ; Invertebrates/*genetics ; Methylococcaceae/*genetics ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Ribulose-Bisphosphate Carboxylase/*genetics ; Symbiosis/*genetics ; }, abstract = {Gutless pogonophorans are generally thought to live in symbiosis with methane-oxidizing bacteria (methanotrophs). We identified a 16S ribosomal RNA gene (rDNA) and a ribulose-1,5-bisphosphate carboxlase/oxygenase (RuBisCO, E.C.4.1.1.39) gene that encode the form I large subunit (cbbL) from symbiont-bearing tissue of the pogonophoran Oligobrachia mashikoi. Phylogenetic analysis of the 16S rDNA sequence suggested that the pogonophoran endosymbiont belonged to the gamma-subdivision of Proteobacteria. The endosymbiont was most closely related to an uncultured bacterium from a hydrocarbon seep, forming a unique clade adjacent to the known methanotrophic 16S rDNA cluster. The RuBisCO gene from the pogonophoran tissue was closely related to those of the chemoautotrophic genera Thiobacillus and Hydrogenovibrio. Presence of the RuBisCO gene suggested a methanotrophic symbiosis because some methanotrophic bacteria are known to be capable of autotrophy via the Calvin cycle. In contrast, particulate and soluble methane monooxygenase genes (pmoA and mmoX) and the methanol dehydrogenase gene (mxaF), which are indicators for methanotrophs or methylotrophs, were not detected by repeated trial of polymerase chain reaction. For 16S rRNA and RuBisCO genes, endosymbiotic localizations were confirmed by in situ hybridization. These results support the possibilities that the pogonophoran host has a novel endosymbiont which belongs to the gamma-subdivision of Proteobacteria, and that the endosymbiont has the gene of the autotrophic enzyme RuBisCO.}, }
@article {pmid14501992, year = {2003}, author = {Hoerauf, A}, title = {Control of filarial infections: not the beginning of the end, but more research is needed.}, journal = {Current opinion in infectious diseases}, volume = {16}, number = {5}, pages = {403-410}, doi = {10.1097/00001432-200310000-00006}, pmid = {14501992}, issn = {0951-7375}, mesh = {Clinical Trials as Topic ; Filariasis/*prevention &amp; control ; Filaricides/therapeutic use ; Humans ; Mosquito Control ; Onchocerciasis/prevention &amp; control ; Vaccines ; }, abstract = {PURPOSE OF REVIEW: Infections with the filarial nematodes affect more than 150 million people mainly in the tropics. The very successful efforts to control filarial infections, however, have to be sustained by new tools that require long-term commitment to research. This review, focusing on reports from 2002 and 2003, highlights recent advances in research on immunology, understanding of pathogenesis and drug development in lymphatic filariasis and onchocerciasis research with potential relevance to the generation of new tools for control.<br><br>RECENT FINDINGS: Dramatic improvement has been achieved in the control of lymphatic filariasis and onchocerciasis by vector control and mass treatment with microfilaricidal drugs. Additional tools that could help in regional elimination or, ultimately, eradication of filariasis may arise from the development of new drugs or a vaccine. Research into the immune responses mediating protection or pathology has provided new insights into the pathways that lead to effector function and immunosuppression, such as T regulatory responses, as well as into genetic predispositions from the host's side, and to the identification of vaccine candidates that show protection in animal models. Recognition of the role the Wolbachia endosymbionts may play in activating the innate immune system has altered our understanding of immunopathology of filariasis and adverse reactions to microfilaricidal drugs. Wolbachia spp. have also proven to be suitable targets for the development of a long-term sterilizing or potentially macrofilaricidal drug.<br><br>SUMMARY: This review summarizes recent developments in the control of filariasis, in particular lymphatic filariasis and onchocerciasis, as well as in modern research into the immunity of filariasis and new drug development that could lead to additional tools necessary for sustained success in filariasis control.}, }
@article {pmid13129523, year = {2003}, author = {Fampa, P and Corrêa-da-Silva, MS and Lima, DC and Oliveira, SM and Motta, MC and Saraiva, EM}, title = {Interaction of insect trypanosomatids with mosquitoes, sand fly and the respective insect cell lines.}, journal = {International journal for parasitology}, volume = {33}, number = {10}, pages = {1019-1026}, doi = {10.1016/s0020-7519(03)00124-3}, pmid = {13129523}, issn = {0020-7519}, mesh = {Aedes/parasitology/ultrastructure ; Animals ; Anopheles/parasitology/ultrastructure ; Cell Line ; Flagella/physiology/ultrastructure ; Host-Parasite Interactions ; Insect Vectors/*parasitology/ultrastructure ; Intestines/parasitology/ultrastructure ; Microscopy, Electron ; Psychodidae/parasitology/ultrastructure ; Symbiosis ; Trypanosomatina/microbiology/*physiology/ultrastructure ; }, abstract = {Interaction experiments between hematophagous insects and monoxenous trypanosomatids have become relevant, once cases of human infection involving these protozoa have been reported. Moreover, investigations related to the interaction of insects with trypanosomatids that harbour an endosymbiotic bacterium and thereby lack the paraflagellar rod structure are important to elucidate the role of this structure in the adhesion process. In this work, we compared the interaction of endosymbiont-bearing trypanosomatids and their aposymbiotic counterpart strains (without endosymbionts) with cell lines of Anopheles gambiae, Aedes albopictus and Lutzomyia longipalpis and with explanted guts of the respective insects. Endosymbiont-bearing strains interacted better with insect cells and guts when compared with aposymbiotic strains. In vitro binding assays revealed that the trypanosomatids interacted with the gut epithelial cells via flagellum and cell body. Flagella attached to the insect gut were enlarged, containing electrondense filaments between the axoneme and flagellar membrane at the point of adhesion. Interactions involving the flagellum lacking paraflagellar rod structure were mainly observed close to tight junctions, between epithelial cells. Endosymbiont-bearing trypanosomatids were able to colonise Aedes aegypti guts after protozoa feeding.}, }
@article {pmid12964989, year = {2003}, author = {Weeks, AR and Velten, R and Stouthamer, R}, title = {Incidence of a new sex-ratio-distorting endosymbiotic bacterium among arthropods.}, journal = {Proceedings. Biological sciences}, volume = {270}, number = {1526}, pages = {1857-1865}, pmid = {12964989}, issn = {0962-8452}, mesh = {Animals ; Arthropods/*physiology ; Base Sequence ; Cytophaga/*genetics/*physiology ; DNA Primers ; DNA, Ribosomal/genetics ; Likelihood Functions ; Molecular Sequence Data ; Phylogeny ; *Sex Ratio ; Symbiosis/*physiology ; Wolbachia/*physiology ; }, abstract = {Many intracellular micro-organisms are now known to cause reproductive abnormalities and other phenomena in their hosts. The endosymbiont Wolbachia is the best known of these reproductive manipulators owing to its extremely high incidence among arthropods and the diverse host effects it has been implicated as causing. However, recent evidence suggests that another intracellular bacterium, a Cytophaga-like organism (CLO), may also induce several reproductive effects in its hosts. Here, we present the first survey of arthropod hosts for infection by the CLO. We use a sensitive hemi-nested polymerase chain reaction method to screen 223 species from 20 arthropod orders for infection by the CLO and Wolbachia. The results indicate that, although not as prevalent as Wolbachia, the CLO infects a significant number of arthropod hosts (ca. 7.2%). In addition, double infections of the CLO and Wolbachia were found in individuals of seven arthropod species. Sequencing analysis of the 16S rDNA region of the CLO indicates evidence for horizontal transmission of the CLO strains. We discuss these results with reference to future studies on host effects induced by intracellular micro-organisms.}, }
@article {pmid12957940, year = {2003}, author = {Baker, BJ and Hugenholtz, P and Dawson, SC and Banfield, JF}, title = {Extremely acidophilic protists from acid mine drainage host Rickettsiales-lineage endosymbionts that have intervening sequences in their 16S rRNA genes.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {9}, pages = {5512-5518}, pmid = {12957940}, issn = {0099-2240}, mesh = {Base Sequence ; In Situ Hybridization, Fluorescence ; Likelihood Functions ; *Mining ; Molecular Sequence Data ; Nucleic Acid Conformation ; Oligonucleotide Probes ; Phylogeny ; RNA, Bacterial/chemistry/genetics ; RNA, Ribosomal, 16S/*genetics ; Rickettsieae/*classification/genetics/*isolation &amp; purification ; Water Microbiology ; }, abstract = {During a molecular phylogenetic survey of extremely acidic (pH < 1), metal-rich acid mine drainage habitats in the Richmond Mine at Iron Mountain, Calif., we detected 16S rRNA gene sequences of a novel bacterial group belonging to the order Rickettsiales in the Alphaproteobacteria. The closest known relatives of this group (92% 16S rRNA gene sequence identity) are endosymbionts of the protist Acanthamoeba. Oligonucleotide 16S rRNA probes were designed and used to observe members of this group within acidophilic protists. To improve visualization of eukaryotic populations in the acid mine drainage samples, broad-specificity probes for eukaryotes were redesigned and combined to highlight this component of the acid mine drainage community. Approximately 4% of protists in the acid mine drainage samples contained endosymbionts. Measurements of internal pH of the protists showed that their cytosol is close to neutral, indicating that the endosymbionts may be neutrophilic. The endosymbionts had a conserved 273-nucleotide intervening sequence (IVS) in variable region V1 of their 16S rRNA genes. The IVS does not match any sequence in current databases, but the predicted secondary structure forms well-defined stem loops. IVSs are uncommon in rRNA genes and appear to be confined to bacteria living in close association with eukaryotes. Based on the phylogenetic novelty of the endosymbiont sequences and initial culture-independent characterization, we propose the name "Candidatus Captivus acidiprotistae." To our knowledge, this is the first report of an endosymbiotic relationship in an extremely acidic habitat.}, }
@article {pmid12957385, year = {2003}, author = {Ryall, K and Harper, JT and Keeling, PJ}, title = {Plastid-derived Type II fatty acid biosynthetic enzymes in chromists.}, journal = {Gene}, volume = {313}, number = {}, pages = {139-148}, doi = {10.1016/s0378-1119(03)00671-1}, pmid = {12957385}, issn = {0378-1119}, mesh = {Acyl-Carrier Protein S-Malonyltransferase ; Acyltransferases/genetics/metabolism ; Amino Acid Sequence ; Enoyl-(Acyl-Carrier-Protein) Reductase (NADH) ; Eukaryota/enzymology/*genetics/metabolism ; Evolution, Molecular ; Fatty Acid Synthases/*genetics/metabolism ; Fatty Acids/biosynthesis ; Molecular Sequence Data ; Oxidoreductases/genetics ; Phylogeny ; Plastids/*enzymology ; Sequence Homology, Amino Acid ; }, abstract = {Fatty acid biosynthesis is a critical process for living organisms, but the evolution of the enzymes involved in this pathway is poorly understood. Animals and fungi use a Type I fatty acid synthase (FAS), a large multifunctional protein found in the cytosol. Bacteria use a Type II complex, where each enzymatic domain is a discrete polypeptide. In plants, fatty acid biosynthesis takes place in the plastid, and utilises a Type II enzyme complex. Recently, the apicomplexan parasites Plasmodium and Toxoplasma have been shown to contain the plastid-targeted Type II FAS. To investigate the distribution of this pathway, we have characterised two Type II enzymes, FabD and FabI, in three other eukaryotes with plastids derived from red algal endosymbionts: cryptomonads, heterokonts, and haptophytes. Collectively, these are referred to as chromists, and are thought to be related to apicomplexa and their relatives. Phylogenies of these enzymes show that the plastid Type II FAS enzymes are found in all groups studied, which most likely means that they originated from the red algal endosymbiont at the outset of the secondary endosymbiosis of their plastids. In addition, although plastid fab D genes are clearly related to one another, they are not related to cyanobacterial homologues, as would be expected. On the other hand, the strongly supported plastid fab I clade is related to cyanobacteria, and contains genes from chlamydiales.}, }
@article {pmid12949182, year = {2003}, author = {Herbeck, JT and Wall, DP and Wernegreen, JJ}, title = {Gene expression level influences amino acid usage, but not codon usage, in the tsetse fly endosymbiont Wigglesworthia.}, journal = {Microbiology (Reading, England)}, volume = {149}, number = {Pt 9}, pages = {2585-2596}, doi = {10.1099/mic.0.26381-0}, pmid = {12949182}, issn = {1350-0872}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/genetics/*metabolism ; Animals ; Base Composition ; Codon/*genetics ; *Gene Expression Regulation, Bacterial ; Tsetse Flies/*microbiology ; Wigglesworthia/*genetics ; }, abstract = {Wigglesworthia glossinidia brevipalpis, the obligate bacterial endosymbiont of the tsetse fly Glossina brevipalpis, is characterized by extreme genome reduction and AT nucleotide composition bias. Here, multivariate statistical analyses are used to test the hypothesis that mutational bias and genetic drift shape synonymous codon usage and amino acid usage of Wigglesworthia. The results show that synonymous codon usage patterns vary little across the genome and do not distinguish genes of putative high and low expression levels, thus indicating a lack of translational selection. Extreme AT composition bias across the genome also drives relative amino acid usage, but predicted high-expression genes (ribosomal proteins and chaperonins) use GC-rich amino acids more frequently than do low-expression genes. The levels and configuration of amino acid differences between Wigglesworthia and Escherichia coli were compared to test the hypothesis that the relatively GC-rich amino acid profiles of high-expression genes reflect greater amino acid conservation at these loci. This hypothesis is supported by reduced levels of protein divergence at predicted high-expression Wigglesworthia genes and similar configurations of amino acid changes across expression categories. Combined, the results suggest that codon and amino acid usage in the Wigglesworthia genome reflect a strong AT mutational bias and elevated levels of genetic drift, consistent with expected effects of an endosymbiotic lifestyle and repeated population bottlenecks. However, these impacts of mutation and drift are apparently attenuated by selection on amino acid composition at high-expression genes.}, }
@article {pmid12945496, year = {2002}, author = {Arvelo, F}, title = {[Mitochondria and apoptosis].}, journal = {Acta cientifica venezolana}, volume = {53}, number = {4}, pages = {297-306}, pmid = {12945496}, issn = {0001-5504}, mesh = {Apoptosis/*physiology ; Bacteria, Aerobic/physiology ; Biological Evolution ; Heat-Shock Proteins/physiology ; Mitochondria/*physiology ; }, abstract = {It is now accepted that mitochondria are endosymbionts, originated in aerobic bacteria which were integrated by the ancestor of eukaryotic cells. A part of the apoptotic machinery could exist in unicellular eukaryotic and some controlling apoptosis components might be present in prokaryotes. It is therefore possible that the mechanism originally involved in the maintenance of the symbiosis between the bacterial ancestor of the mitochondria and the host cell precursor of eukaryotes, provided the basis for the actual mechanism controlling cell survival. Metazoans would have improved this possibility by connecting to the mitochondria as principal effector of cellular death to the pathways of signal transduction. A variety of events appoint to the mitochondria as principal effector of the apoptosis. This including the release caspase activators (cytochrome c), changes in electron transport, loss of mitochondrial transmembrane potential, altered cellular oxidation-reduction, and participation of pro and antiapoptotic Bcl-2 proteins. The different signals that converge on mitochondria for activation or inhibition of these events, delineate several pathways in the physiology of the cellular death.}, }
@article {pmid12914918, year = {2003}, author = {Illingworth, C and Mayer, MJ and Elliott, K and Hanfrey, C and Walton, NJ and Michael, AJ}, title = {The diverse bacterial origins of the Arabidopsis polyamine biosynthetic pathway.}, journal = {FEBS letters}, volume = {549}, number = {1-3}, pages = {26-30}, doi = {10.1016/s0014-5793(03)00756-7}, pmid = {12914918}, issn = {0014-5793}, mesh = {Amino Acid Sequence ; Arabidopsis/*enzymology/genetics ; Chloroplasts ; Cloning, Molecular ; Cyanobacteria/*enzymology/genetics ; *Evolution, Molecular ; Expressed Sequence Tags ; Genes, Plant ; Hydrolases/*genetics ; Molecular Sequence Data ; Plant Proteins/genetics ; Polyamines ; Putrescine/*biosynthesis ; Sequence Alignment ; }, abstract = {We functionally identified the last remaining step in the plant polyamine biosynthetic pathway by expressing an Arabidopsis thaliana agmatine iminohydrolase cDNA in yeast. Inspection of the whole pathway suggests that the arginine decarboxylase, agmatine iminohydrolase, N-carbamoylputrescine amidohydrolase route to putrescine in plants was inherited from the cyanobacterial ancestor of the chloroplast. However, the rest of the pathway including ornithine decarboxylase and spermidine synthase was probably inherited from bacterial genes present in the original host cell, common ancestor of plants and animals, that acquired the cyanobacterial endosymbiont. An exception is S-adenosylmethionine decarboxylase, which may represent a eukaryote-specific enzyme form.}, }
@article {pmid12897857, year = {2003}, author = {Harris, HL and Braig, HR}, title = {Sperm chromatin remodelling and Wolbachia-induced cytoplasmic incompatibility in Drosophila.}, journal = {Biochemistry and cell biology = Biochimie et biologie cellulaire}, volume = {81}, number = {3}, pages = {229-240}, doi = {10.1139/o03-053}, pmid = {12897857}, issn = {0829-8211}, mesh = {Animals ; Chromatin/*physiology ; Cytoplasm/physiology ; DNA Methylation ; Drosophila/genetics/microbiology/*physiology ; Female ; Fertility/genetics/physiology ; Male ; Mutation ; Spermatogenesis/physiology ; Spermatozoa/*microbiology ; Wolbachia/*physiology ; }, abstract = {Wolbachia pipientis is an obligate bacterial endosymbiont, which has successfully invaded approximately 20% of all insect species by manipulating their normal developmental patterns. Wolbachia-induced phenotypes include parthenogenesis, male killing, and, most notably, cytoplasmic incompatibility. In the future these phenotypes might be useful in controlling or modifying insect populations but this will depend on our understanding of the basic molecular processes underlying insect fertilization and development. Wolbachia-infected Drosophila simulans express high levels of cytoplasmic incompatibility in which the sperm nucleus is modified and does not form a normal male pronucleus when fertilizing eggs from uninfected females. The sperm modification is somehow rescued in eggs infected with the same strain of Wolbachia. Thus, D. simulans has become an excellent model organism for investigating the manner in which endosymbionts can alter reproductive programs in insect hosts. This paper reviews the current knowledge of Drosophila early development and particularly sperm function. Developmental mutations in Drosophila that are known to affect sperm function will also be discussed.incompatibility.}, }
@article {pmid12886019, year = {2003}, author = {Gil, R and Silva, FJ and Zientz, E and Delmotte, F and González-Candelas, F and Latorre, A and Rausell, C and Kamerbeek, J and Gadau, J and Hölldobler, B and van Ham, RC and Gross, R and Moya, A}, title = {The genome sequence of Blochmannia floridanus: comparative analysis of reduced genomes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {100}, number = {16}, pages = {9388-9393}, pmid = {12886019}, issn = {0027-8424}, mesh = {Animals ; Gammaproteobacteria/*genetics ; *Genome, Bacterial ; Insecta ; Models, Biological ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Sequence Analysis, DNA ; }, abstract = {Bacterial symbioses are widespread among insects, probably being one of the key factors of their evolutionary success. We present the complete genome sequence of Blochmannia floridanus, the primary endosymbiont of carpenter ants. Although these ants feed on a complex diet, this symbiosis very likely has a nutritional basis: Blochmannia is able to supply nitrogen and sulfur compounds to the host while it takes advantage of the host metabolic machinery. Remarkably, these bacteria lack all known genes involved in replication initiation (dnaA, priA, and recA). The phylogenetic analysis of a set of conserved protein-coding genes shows that Bl. floridanus is phylogenetically related to Buchnera aphidicola and Wigglesworthia glossinidia, the other endosymbiotic bacteria whose complete genomes have been sequenced so far. Comparative analysis of the five known genomes from insect endosymbiotic bacteria reveals they share only 313 genes, a number that may be close to the minimum gene set necessary to sustain endosymbiotic life.}, }
@article {pmid12882969, year = {2003}, author = {Minic, Z and Herve, G}, title = {Arginine metabolism in the deep sea tube worm Riftia pachyptila and its bacterial endosymbiont.}, journal = {The Journal of biological chemistry}, volume = {278}, number = {42}, pages = {40527-40533}, doi = {10.1074/jbc.M307835200}, pmid = {12882969}, issn = {0021-9258}, mesh = {Animals ; Arginine/chemistry/*metabolism ; Argininosuccinate Synthase/metabolism ; Carbon/metabolism ; Carboxy-Lyases/metabolism ; Chromatography, Ion Exchange ; Dose-Response Relationship, Drug ; Kinetics ; Models, Biological ; Models, Chemical ; Nitrogen/metabolism ; Ornithine Carbamoyltransferase/metabolism ; Parasites ; Polychaeta/*metabolism/*microbiology ; Temperature ; }, abstract = {The present study describes the distribution and properties of enzymes involved in arginine metabolism in Riftia pachyptila, a tubeworm living around deep sea hydrothermal vents and known to be engaged in a highly specific symbiotic association with a bacterium. The results obtained show that the arginine biosynthetic enzymes, carbamyl phosphate synthetase, ornithine transcarbamylase, and argininosuccinate synthetase are present in all of the tissues of the worm and in the bacteria. Thus, Riftia and its bacterial endosymbiont can assimilate nitrogen and carbon via this arginine biosynthetic pathway. The kinetic properties of ornithine transcarbamylase strongly suggest that neither Riftia nor the bacteria possess the catabolic form of this enzyme belonging to the arginine deiminase pathway, the absence of this pathway being confirmed by the lack of arginine deiminase activity. Arginine decarboxylase and ornithine decarboxylase are involved in the biosynthesis of polyamines such as putrescine and agmatine. These activities are present in the trophosome, the symbiont-harboring tissue, and are higher in the isolated bacteria than in the trophosome, indicating that these enzymes are of bacterial origin. This finding indicates that Riftia is dependent on its bacterial endosymbiont for the biosynthesis of polyamines that are important for its metabolism and physiology. These results emphasize a particular organization of the arginine metabolism and the exchanges of metabolites between the two partners of this symbiosis.}, }
@article {pmid12878661, year = {2003}, author = {Pruski, AM and Fiala-Médioni, A}, title = {Stimulatory effect of sulphide on thiotaurine synthesis in three hydrothermal-vent species from the East Pacific Rise.}, journal = {The Journal of experimental biology}, volume = {206}, number = {Pt 17}, pages = {2923-2930}, doi = {10.1242/jeb.00513}, pmid = {12878661}, issn = {0022-0949}, mesh = {*Adaptation, Physiological ; Amino Acids, Sulfur/analysis/*biosynthesis ; Animals ; Chromatography, High Pressure Liquid ; Invertebrates/chemistry/*metabolism ; Kinetics ; Pacific Ocean ; Sulfides/*metabolism ; Sulfur-Reducing Bacteria/*metabolism ; *Symbiosis ; Taurine/*analogs &amp; derivatives/metabolism ; }, abstract = {Symbiotic associations between marine invertebrates and sulphur-oxidising bacteria are a common feature in communities from sulphide-rich environments, such as those flourishing in the vicinity of hydrothermal vents. While the bacterial endosymbionts provide the host with an undoubted nutritional advantage, their presence also requires specific adaptations for the transport and storage of sulphide, which is a potent toxin of aerobic respiration. Although different mechanisms such as the reversible binding of sulphide to serum binding proteins or its oxidation to less toxic forms have been described, many questions still remained unanswered. In the last decade, large amounts of thiotaurine, an unusual sulphur-amino acid, have been reported in sulphur-based symbioses from hydrothermal vents and cold seeps. Compounds such as thiotaurine are known to take part in trans-sulphuration reactions, so the involvement of thiotaurine in sulphide metabolism has been suggested. We present here an experimental study on thiotaurine biosynthesis in three sulphur-oxidising symbiont-bearing species from the East Pacific Rise: the vesicomyid Calyptogena magnifica, the mytilid Bathymodiolus thermophilus and the vestimentiferan Riftia pachyptila. In all three species, thiotaurine synthesis is stimulated in vitro by an input of sulphide, as well as by thiosulphate in B. thermophilus. Several distinct metabolic pathways seem to occur, however, since hypotaurine is the only precursor in the bivalves C. magnifica and B. thermophilus, whereas thiotaurine is also produced from taurine in R. pachyptila. Hypotaurine (NH(2)-CH(2)-CH(2)-SO(2)H) and thiotaurine (NH(2)-CH(2)-CH(2)-SO(2)SH) are two free sulphur amino acids whose chemical formulae differ by only one atom of sulphur. It appears that the extent of thiotaurine synthesis is strongly dependent on the initial equilibrium between these two amino acids, since the strongest thiotaurine synthesis rates are found in tissues with the lowest initial thiotaurine concentration. Moreover, the lack of any effect of sulphide in symbiont-free tissues and in gills of the methanotrophic mussel Bathymodiolus childressi reinforces the assumption that thiotaurine synthesis is a specific adaptation to the thiotrophic mode of life. While the precise function (i.e. transport and/or storage of sulphide) of hypotaurine and thiotaurine has yet to be established, our results strongly support a general role for these free amino acids in the metabolism of sulphide in hydrothermal-vent thiotrophic symbioses.}, }
@article {pmid12871231, year = {2003}, author = {Hoffmeister, M and Martin, W}, title = {Interspecific evolution: microbial symbiosis, endosymbiosis and gene transfer.}, journal = {Environmental microbiology}, volume = {5}, number = {8}, pages = {641-649}, doi = {10.1046/j.1462-2920.2003.00454.x}, pmid = {12871231}, issn = {1462-2912}, mesh = {Animals ; Archaea/*physiology ; *Bacterial Physiological Phenomena ; *Biological Evolution ; Chlorophyta/genetics/physiology/ultrastructure ; Chloroplasts/physiology ; *Gene Transfer, Horizontal ; Genes, Bacterial ; Invertebrates/genetics/microbiology/*physiology ; Mitochondria/physiology ; *Symbiosis ; }, abstract = {Microbial symbioses are interesting in their own right and also serve as exemplary models to help biologists to understand two important symbioses in the evolutionary past of eukaryotic cells: the origins of chloroplasts and mitochondria. Most, if not all, microbial symbioses have a chemical basis: compounds produced by one partner are useful for the other. But symbioses can also entail the transfer of genes from one partner to the other, which in some cases cements two cells into a bipartite, co-evolving unit. Here, we discuss some microbial symbioses in which progress is being made in uncovering the nature of symbiotic interactions: anaerobic methane-oxidizing consortia, marine worms that possess endosymbionts instead of a digestive tract, amino acid-producing endosymbionts of aphids, prokaryotic endosymbionts living within a prokaryotic host within mealybugs, endosymbionts of an insect vector of human disease and a photosynthetic sea slug that steals chloroplasts from algae. In the case of chloroplasts and mitochondria, examples of recent and ancient gene transfer to the chromosomes of their host cell illustrate the process of genetic merger in the wake of organelle origins.}, }
@article {pmid12869541, year = {2003}, author = {Karbarz, MJ and Kalb, SR and Cotter, RJ and Raetz, CR}, title = {Expression cloning and biochemical characterization of a Rhizobium leguminosarum lipid A 1-phosphatase.}, journal = {The Journal of biological chemistry}, volume = {278}, number = {41}, pages = {39269-39279}, pmid = {12869541}, issn = {0021-9258}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; R37 GM051796-06/GM/NIGMS NIH HHS/United States ; GM-08558/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Base Sequence ; Carbohydrate Sequence ; Cloning, Molecular ; Cosmids ; DNA, Bacterial/genetics ; Genes, Bacterial ; Lipid A/biosynthesis/chemistry/*metabolism ; Molecular Sequence Data ; Molecular Structure ; Phosphoric Monoester Hydrolases/chemistry/*genetics/*metabolism ; Recombinant Proteins/chemistry/genetics/metabolism ; Rhizobium leguminosarum/*enzymology/*genetics ; Sinorhizobium meliloti/genetics ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; }, abstract = {Lipid A of Rhizobium leguminosarum, a nitrogen-fixing plant endosymbiont, displays several significant structural differences when compared with Escherichia coli. An especially striking feature of R. leguminosarum lipid A is that it lacks both the 1- and 4'-phosphate groups. Distinct lipid A phosphatases that attack either the 1 or the 4' positions have previously been identified in extracts of R. leguminosarum and Rhizobium etli but not Sinorhizobium meliloti or E. coli. Here we describe the identification of a hybrid cosmid (pMJK-1) containing a 25-kb R. leguminosarum 3841 DNA insert that directs the overexpression of the lipid A 1-phosphatase. Transfer of pMJK-1 into S. meliloti 1021 results in heterologous expression of 1-phosphatase activity, which is normally absent in extracts of strain 1021, and confers resistance to polymyxin. Sequencing of a 7-kb DNA fragment derived from the insert of pMJK-1 revealed the presence of a lipid phosphatase ortholog (designated LpxE). Expression of lpxE in E. coli behind the T7lac promoter results in the appearance of robust 1-phosphatase activity, which is normally absent in E. coli membranes. Matrix-assisted laser-desorption/time of flight and radiochemical analysis of the product generated in vitro from the model substrate lipid IVA confirms the selective removal of the 1-phosphate group. These findings show that lpxE is the structural gene for the 1-phosphatase. The availability of lpxE may facilitate the re-engineering of lipid A structures in diverse Gram-negative bacteria and allow assessment of the role of the 1-phosphatase in R. leguminosarum symbiosis with plants. Possible orthologs of LpxE are present in some intracellular human pathogens, including Francisella tularensis, Brucella melitensis, and Legionella pneumophila.}, }
@article {pmid12860700, year = {2003}, author = {Greub, G and La Scola, B and Raoult, D}, title = {Parachlamydia acanthamoeba is endosymbiotic or lytic for Acanthamoeba polyphaga depending on the incubation temperature.}, journal = {Annals of the New York Academy of Sciences}, volume = {990}, number = {}, pages = {628-634}, doi = {10.1111/j.1749-6632.2003.tb07437.x}, pmid = {12860700}, issn = {0077-8923}, mesh = {Acanthamoeba/microbiology/*physiology ; Animals ; Chlamydiales/genetics/growth &amp; development/*physiology ; DNA, Bacterial/genetics/isolation &amp; purification ; Polymerase Chain Reaction/methods ; *Symbiosis ; Temperature ; }, abstract = {Parachlamydiaceae are potential emerging pathogens that naturally infect free-living amoebae. We investigated the affects of incubation temperature on the growth and cytopathic effect of P. acanthamoeba in Acanthamoeba polyphaga. A. polyphaga were infected with P. acanthamoeba and incubated at different temperatures for ten days. Bacterial growth was quantified by real-time PCR. Cytopathic effects were determined by counting the number of cysts and viable amoebae (unstained with trypan blue) in Nageotte counting chambers. Uninfected amoebae cultures were used as negative control. At 32, 35, and 37 degrees C, we observed a significant decrease in the number of viable A. polyphaga that contrasted with the delayed and smaller decrease in the number of living A. polyphaga observed at 25, 28, and 30 degrees C. Higher incubation temperature, which is associated with amoebal lysis, surprisingly was not associated with increased growth rate. P. acanthamoeba is lytic for A. polyphaga at 32-37 degrees C but endosymbiotic at 25-30 degrees C. This suggests that A. polyphaga may be a reservoir of endosymbionts at the lower temperature of the nasal mucosa, which may be liberated by lysis at higher temperature, for instance, when the amoeba is inhaled and reaches the lower respiratory tract.}, }
@article {pmid12860595, year = {2003}, author = {Rudakov, NV and Shpynov, SN and Samoilenko, IE and Tankibaev, MA}, title = {Ecology and epidemiology of spotted fever group Rickettsiae and new data from their study in Russia and Kazakhstan.}, journal = {Annals of the New York Academy of Sciences}, volume = {990}, number = {}, pages = {12-24}, doi = {10.1111/j.1749-6632.2003.tb07332.x}, pmid = {12860595}, issn = {0077-8923}, mesh = {Animals ; Boutonneuse Fever/*epidemiology/transmission ; Humans ; Kazakhstan/epidemiology ; Rickettsia conorii ; Rickettsia rickettsii ; Rocky Mountain Spotted Fever/*epidemiology/transmission ; Russia/epidemiology ; Tick-Borne Diseases/microbiology/transmission ; Ticks/microbiology ; }, abstract = {Rickettsiae represent a wide range of pathogenicity from classic and new pathogens to endosymbionts of eukaryotic cells. Recent studies of rickettsiae have widened the number of representatives of genus Rickettsia, especially in the spotted fever group (SFG). Rickettsiae of SFG are tick-borne microorganisms with effective transovarial and transstadial transmission. The main hosts are ticks (Dermacentor, Rhipicephalus, Haemophysalis, Ixodes, and Amlyomma). Strategy of maintenance of tick microorganisms is vector-type transfer and tropism to endothelial cells or blood cells of animals. The main epidemiological characteristics of SFG rickettsioses are different kinds of anthropogenic activity and connection of morbidity with seasonal tick activity. Two other important characteristics are quantitative and qualitative heterogeneity of its populations (different genotypes of Rickettsia in the same territory and species of ticks, for example) and coexistence of different tick microorganisms (rickettsiae, borreliae, ehrlichiae, tick-borne encephalitis complex viruses, etc.). The role of new rickettsial genotypes in infectious diseases is poorly understood. Simultaneous study of ticks after bites, blood and skin biopsies of patients may be used for detection of spectrum of tick-borne pathogens in mixed natural foci. Interference between rickettsiae with different virulence may affect its populations and levels of morbidity.}, }
@article {pmid12856950, year = {2003}, author = {Chaal, BK and Ishida, K and Green, BR}, title = {A thylakoidal processing peptidase from the heterokont alga Heterosigma akashiwo.}, journal = {Plant molecular biology}, volume = {52}, number = {2}, pages = {463-472}, pmid = {12856950}, issn = {0167-4412}, mesh = {Algal Proteins/genetics/metabolism ; Amino Acid Sequence ; Chloroplasts/drug effects/enzymology/ultrastructure ; Electrophoresis, Polyacrylamide Gel ; Endopeptidases/*genetics/*metabolism ; Enzyme Inhibitors/pharmacology ; Eukaryota/*enzymology/genetics/ultrastructure ; Microscopy, Electron ; Molecular Sequence Data ; Peas/enzymology ; Protein Precursors/genetics ; Protein Sorting Signals/genetics ; Sequence Homology, Amino Acid ; }, abstract = {Heterokont algae such as diatoms, brown seaweeds and the raphidophyte Heterosigma akashiwo acquired their chloroplasts via a secondary endosymbiosis involving a red algal endosymbiont and a eukaryote host, resulting in chloroplasts surrounded by four membranes rather than two. The precursor of a nuclear-encoded thylakoid lumen protein, PsbO, from Heterosigma has a presequence composed of a typical ER signal peptide followed by putative stromal and thylakoid targeting domains. A processing enzyme associated with Heterosigma thylakoids cleaved the presequence (with or without the ER signal sequence) in a single step, giving a product of the size of the mature protein. Its sensitivity to a penem inhibitor and insensitivity to other protease inhibitors suggest that it is a member of the Type I signal peptidase family. Furthermore the Heterosigma enzyme appeared to have similar substrate specificity to the pea thylakoidal processing peptidase.}, }
@article {pmid12856318, year = {2002}, author = {Fischer, P and Schmetz, C and Bandi, C and Bonow, I and Mand, S and Fischer, K and Büttner, DW}, title = {Tunga penetrans: molecular identification of Wolbachia endobacteria and their recognition by antibodies against proteins of endobacteria from filarial parasites.}, journal = {Experimental parasitology}, volume = {102}, number = {3-4}, pages = {201-211}, doi = {10.1016/s0014-4894(03)00058-4}, pmid = {12856318}, issn = {0014-4894}, mesh = {Amino Acid Sequence ; Animals ; Aspartate Aminotransferases/chemistry/genetics/*immunology ; Bacterial Outer Membrane Proteins/chemistry/genetics/*immunology ; Bacterial Proteins/chemistry/genetics/*immunology ; Base Sequence ; Child ; *Cytoskeletal Proteins ; DNA Primers/chemistry ; DNA, Bacterial/chemistry ; DNA, Ribosomal/chemistry ; Female ; Humans ; Immune Sera/immunology ; Immunohistochemistry ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Alignment ; Siphonaptera/*microbiology/ultrastructure ; Wolbachia/classification/genetics/immunology/*isolation &amp; purification ; }, abstract = {In search of Wolbachia in human parasites, Wolbachia were identified in the sand flea Tunga penetrans. PCR and DNA sequencing of the bacterial 16S rDNA, the ftsZ cell division protein, the Wolbachia surface protein (wsp) and the Wolbachia aspartate aminotransferase genes revealed a high similarity to the respective sequences of endosymbionts of filarial nematodes. Using these sequences a phylogenetic tree was generated, that indicates a close relationship between Wolbachia from T. penetrans and from filarial parasites, but possibly as a member of a new supergroup. Ultrastructural studies showed that Wolbachia are abundant in the ovaries of neosomic fleas, whereas other, smaller and morphologically distinct, bacteria were observed in the lumen of the intestine. Wolbachia were labeled by immunohistology and immunogold electron microscopy using polyclonal antibodies against wsp of Drosophila, of the filarial parasite Dirofilaria immitis, or against hsp 60 from Yersinia enterocolitica. These results show that as in filariasis, humans with tungiasis are exposed to Wolbachia. Furthermore, antisera raised against proteins of Wolbachia from arthropods or from filarial parasites can be immunologically cross-reactive.}, }
@article {pmid12839805, year = {2003}, author = {Ben-Haim, Y and Zicherman-Keren, M and Rosenberg, E}, title = {Temperature-regulated bleaching and lysis of the coral Pocillopora damicornis by the novel pathogen Vibrio coralliilyticus.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {7}, pages = {4236-4242}, pmid = {12839805}, issn = {0099-2240}, mesh = {Amino Acid Sequence ; Animals ; Anthozoa/*metabolism/*microbiology ; Bacteriolysis ; Endopeptidases/chemistry/genetics/metabolism ; Eukaryota/*growth &amp; development ; Molecular Sequence Data ; Seawater ; *Symbiosis ; *Temperature ; Vibrio/enzymology/*pathogenicity/physiology ; }, abstract = {Coral bleaching is the disruption of symbioses between coral animals and their photosynthetic microalgal endosymbionts (zooxanthellae). It has been suggested that large-scale bleaching episodes are linked to global warming. The data presented here demonstrate that Vibrio coralliilyticus is an etiological agent of bleaching of the coral Pocillopora damicornis. This bacterium was present at high levels in bleached P. damicornis but absent from healthy corals. The bacterium was isolated in pure culture, characterized microbiologically, and shown to cause bleaching when it was inoculated onto healthy corals at 25 degrees C. The pathogen was reisolated from the diseased tissues of the infected corals. The zooxanthella concentration in the bacterium-bleached corals was less than 12% of the zooxanthella concentration in healthy corals. When P. damicornis was infected with V. coralliilyticus at higher temperatures (27 and 29 degrees C), the corals lysed within 2 weeks, indicating that the seawater temperature is a critical environmental parameter in determining the outcome of infection. A large increase in the level of the extracellular protease activity of V. coralliilyticus occurred at the same temperature range (24 to 28 degrees C) as the transition from bleaching to lysis of the corals. We suggest that bleaching of P. damicornis results from an attack on the algae, whereas bacterium-induced lysis and death are promoted by bacterial extracellular proteases. The data presented here support the bacterial hypothesis of coral bleaching.}, }
@article {pmid12832648, year = {2003}, author = {Woolfit, M and Bromham, L}, title = {Increased rates of sequence evolution in endosymbiotic bacteria and fungi with small effective population sizes.}, journal = {Molecular biology and evolution}, volume = {20}, number = {9}, pages = {1545-1555}, doi = {10.1093/molbev/msg167}, pmid = {12832648}, issn = {0737-4038}, mesh = {Animals ; Ants/microbiology ; Aphids/microbiology ; Bacteria/*genetics ; Bacterial Physiological Phenomena ; Base Composition ; Coleoptera/microbiology ; *Evolution, Molecular ; Fungi/*genetics ; Genetic Variation ; Genome ; Mutation ; Phylogeny ; RNA, Ribosomal, 16S/chemistry/*genetics ; *Selection, Genetic ; *Symbiosis ; }, abstract = {Mutualistic, maternally transmitted endosymbiotic microorganisms undergo severe population bottlenecks at each host generation, resulting in a reduction in effective population size (Ne). Previous studies of Buchnera, the primary endosymbiont of aphids, and of several other species of endosymbiotic bacteria have shown that these species exhibit an increase in the rate of substitution of slightly deleterious mutations, among other predicted effects of increased drift due to small Ne, such as reduced codon bias. However, these studies have been limited in taxonomic scope, and it was therefore not clear whether the increase in rate is a general feature of endosymbiont lineages. Here, we test the prediction that a long-term reduction in Ne causes an increase in substitution rate using DNA sequences of the 16S rRNA gene from 13 phylogenetically independent comparisons between taxonomically diverse endosymbiotic microorganisms and their free-living relatives. Maximum likelihood and distance-based methods both indicate a significant increase in substitution rate in a wide range of bacterial and fungal endosymbionts compared to closely related free-living lineages. We use the same data set to test whether 16S genes from endosymbionts display increased A + T content, another indicator of increased genetic drift, and find that there is no significant difference in base composition between endosymbiont and nonendosymbiont 16S genes. However, analysis of an additional data set of whole bacterial genomes demonstrates that, while host-dependent bacteria have significantly increased genomic A + T content, the base content of the 16S gene tends to vary less than that of the whole genome. It is possible that selection for stability of rRNA is strong enough to overcome the effects of drift toward increased A + T content in endosymbiont 16S genes, despite the reduced effective population sizes of these organisms.}, }
@article {pmid12832624, year = {2003}, author = {Theissen, U and Hoffmeister, M and Grieshaber, M and Martin, W}, title = {Single eubacterial origin of eukaryotic sulfide:quinone oxidoreductase, a mitochondrial enzyme conserved from the early evolution of eukaryotes during anoxic and sulfidic times.}, journal = {Molecular biology and evolution}, volume = {20}, number = {9}, pages = {1564-1574}, doi = {10.1093/molbev/msg174}, pmid = {12832624}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Anaerobiosis ; Animals ; Bacteria/enzymology/genetics ; Conserved Sequence ; DNA, Mitochondrial/genetics ; Eukaryotic Cells ; *Evolution, Molecular ; Gene Duplication ; Humans ; Mitochondria/*enzymology/genetics ; Models, Genetic ; Molecular Sequence Data ; Phylogeny ; Quinone Reductases/*genetics ; Sequence Homology, Amino Acid ; Sulfides/metabolism ; }, abstract = {Mitochondria occur as aerobic, facultatively anaerobic, and, in the case of hydrogenosomes, strictly anaerobic forms. This physiological diversity of mitochondrial oxygen requirement is paralleled by that of free-living alpha-proteobacteria, the group of eubacteria from which mitochondria arose, many of which are facultative anaerobes. Although ATP synthesis in mitochondria usually involves the oxidation of reduced carbon compounds, many alpha-proteobacteria and some mitochondria are known to use sulfide (H2S) as an electron donor for the respiratory chain and its associated ATP synthesis. In many eubacteria, the oxidation of sulfide involves the enzyme sulfide:quinone oxidoreductase (SQR). Nuclear-encoded homologs of SQR are found in several eukaryotic genomes. Here we show that eukaryotic SQR genes characterized to date can be traced to a single acquisition from a eubacterial donor in the common ancestor of animals and fungi. Yet, SQR is not a well-conserved protein, and our analyses suggest that the SQR gene has furthermore undergone some lateral transfer among prokaryotes during evolution, leaving the precise eubacterial lineage from which eukaryotes obtained their SQR difficult to discern with phylogenetic methods. Newer geochemical data and microfossil evidence indicate that major phases of early eukaryotic diversification occurred during a period of the Earth's history from 1 to 2 billion years before present in which the subsurface ocean waters contained almost no oxygen but contained high concentrations of sulfide, suggesting that the ability to deal with sulfide was essential for prokaryotes and eukaryotes during that time. Notwithstanding poor resolution in deep SQR phylogeny and lack of a specifically alpha-protebacterial branch for the eukaryotic enzyme on the basis of current lineage sampling, a single eubacterial origin of eukaryotic SQR and the evident need of ancient eukaryotes to deal with sulfide, a process today germane to mitochondrial quinone reduction, are compatible with the view that eukaryotic SQR was an acquisition from the mitochondrial endosymbiont.}, }
@article {pmid12823454, year = {2003}, author = {Bazinet, C and Rollins, JE}, title = {Rickettsia-like mitochondrial motility in Drosophila spermiogenesis.}, journal = {Evolution &amp; development}, volume = {5}, number = {4}, pages = {379-385}, doi = {10.1046/j.1525-142x.2003.03045.x}, pmid = {12823454}, issn = {1520-541X}, support = {R01 HD36498-01/HD/NICHD NIH HHS/United States ; }, mesh = {Actins/metabolism ; Animals ; Drosophila melanogaster/*physiology ; Male ; Mitochondria/*physiology ; *Phylogeny ; Rickettsia/*cytology/genetics/metabolism ; *Sperm Motility ; Spermatogenesis/*physiology ; Testis/ultrastructure ; }, abstract = {Although it is generally accepted that mitochondria and chloroplasts are descended in evolution from bacteria, the potential contributions of their endosymbiont ancestors to specialized cellular pathways in development remain largely unexplored. Here we show that a motile behavior of mitochondria in Drosophila spermiogenesis is strikingly similar to the actin-based "comet tail" motility of several bacteria. A combination of electron and fluorescence microscopy demonstrates major reorganization and movement of mitochondria ahead of, and in close association with, dense conical arrays of actin filaments in the sperm individualization complex, which mediates the resolution of male germline syncytia into separate gametes. Because of several other parallels between the movement of the individualization complex and the motility behavior of some rickettsiae, the bacterial family from which mitochondria are most likely descended, this motility phenomenon is a strong candidate for a true vestige of endosymbiont behavior in contemporary mitochondria. The potential conservation of an ancient endosymbiont motility mechanism within a highly conserved feature of gametogenesis, the resolution of germline syncytia, may indicate a formative role for the endosymbiotic ancestor of mitochondria in the evolution of this developmental pathway.}, }
@article {pmid12817081, year = {2003}, author = {Stegemann, S and Hartmann, S and Ruf, S and Bock, R}, title = {High-frequency gene transfer from the chloroplast genome to the nucleus.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {100}, number = {15}, pages = {8828-8833}, pmid = {12817081}, issn = {0027-8424}, mesh = {Base Sequence ; Cell Nucleus/genetics ; Chloroplasts/*genetics ; Crosses, Genetic ; DNA, Chloroplast/genetics ; Evolution, Molecular ; *Gene Transfer, Horizontal ; Genetic Markers ; Genetic Variation ; *Genome, Plant ; Kanamycin Resistance/genetics ; Models, Genetic ; Plants, Genetically Modified ; Symbiosis ; Tobacco/genetics/microbiology ; }, abstract = {Eukaryotic cells arose through endosymbiotic uptake of free-living bacteria followed by massive gene transfer from the genome of the endosymbiont to the host nuclear genome. Because this gene transfer took place over a time scale of hundreds of millions of years, direct observation and analysis of primary transfer events has remained difficult. Hence, very little is known about the evolutionary frequency of gene transfer events, the size of transferred genome fragments, the molecular mechanisms of the transfer process, or the environmental conditions favoring its occurrence. We describe here a genetic system based on transgenic chloroplasts carrying a nuclear selectable marker gene that allows the efficient selection of plants with a nuclear genome that carries pieces transferred from the chloroplast genome. We can select such gene transfer events from a surprisingly small population of plant cells, indicating that the escape of genetic material from the chloroplast to the nuclear genome occurs much more frequently than generally believed and thus may contribute significantly to intraspecific and intraorganismic genetic variation.}, }
@article {pmid12816546, year = {2003}, author = {McGarry, HF and Pfarr, K and Egerton, G and Hoerauf, A and Akue, JP and Enyong, P and Wanji, S and Kläger, SL and Bianco, AE and Beeching, NJ and Taylor, MJ}, title = {Evidence against Wolbachia symbiosis in Loa loa.}, journal = {Filaria journal}, volume = {2}, number = {1}, pages = {9}, pmid = {12816546}, issn = {1475-2883}, abstract = {BACKGROUND: The majority of filarial nematode species are host to Wolbachia bacterial endosymbionts, although a few including Acanthocheilonema viteae, Onchocerca flexuosa and Setaria equina have been shown to be free of infection. Comparisons of species with and without symbionts can provide important information on the role of Wolbachia symbiosis in the biology of the nematode hosts and the contribution of the bacteria to the development of disease. Previous studies by electron microscopy and PCR have failed to detect intracellular bacterial infection in Loa loa. Here we use molecular and immunohistological techniques to confirm this finding. METHODS: We have used a combination of PCR amplification of bacterial genes (16S ribosomal DNA [rDNA], ftsZ and Wolbachia surface protein [WSP]) on samples of L. loa adults, third-stage larvae (L3) and microfilariae (mf) and immunohistology on L. loa adults and mf derived from human volunteers to determine the presence or absence of Wolbachia endosymbionts. Samples used in the PCR analysis included 5 adult female worms, 4 adult male worms, 5 mf samples and 2 samples of L3. The quality and purity of nematode DNA was tested by PCR amplification of nematode 5S rDNA and with diagnostic primers from the target species and used to confirm the absence of contamination from Onchocerca sp., Mansonella perstans, M. streptocerca and Wuchereria bancrofti. Immunohistology was carried out by light and electron microscopy on L. loa adults and mf and sections were probed with rabbit antibodies raised to recombinant Brugia malayi Wolbachia WSP. Samples from nematodes known to be infected with Wolbachia (O. volvulus, O. ochengi, Litomosoides sigmodontis and B. malayi) were used as positive controls and A. viteae as a negative control. RESULTS: Single PCR analysis using primer sets for the bacterial genes 16S rDNA, ftsZ, and WSP were negative for all DNA samples from L. loa. Positive PCR reactions were obtained from DNA samples derived from species known to be infected with Wolbachia, which confirmed the suitability of the primers and PCR conditions. The quality and purity of nematode DNA samples was verified by PCR amplification of 5S rDNA and with nematode diagnostic primers. Additional analysis by 'long PCR' failed to produce any further evidence for Wolbachia symbiosis. Immunohistology of L. loa adults and mf confirmed the results of the PCR with no evidence for Wolbachia symbiosis. CONCLUSION: DNA analysis and immunohistology provided no evidence for Wolbachia symbiosis in L. loa.}, }
@article {pmid12801477, year = {2003}, author = {Rodriguez-Lanetty, M}, title = {Evolving lineages of Symbiodinium-like dinoflagellates based on ITS1 rDNA.}, journal = {Molecular phylogenetics and evolution}, volume = {28}, number = {1}, pages = {152-168}, doi = {10.1016/s1055-7903(03)00033-2}, pmid = {12801477}, issn = {1055-7903}, mesh = {Animals ; DNA, Ribosomal/*genetics ; Dinoflagellida/*classification/genetics/physiology ; Geography ; Haplotypes ; Oceans and Seas ; *Phylogeny ; Recombination, Genetic ; *Symbiosis ; }, abstract = {Symbiodinium-like dinoflagellates have been shown to be a diverse group of endosymbionts that associate mutualistically with many kinds of coral reef dwellers, including cnidarians, molluscs, and protists. A high number of genetically ITS types of symbionts have been reported to date. However, whether these recently identified Symbiodinium ITS types indeed represent independent evolutionary lineages is still unsettled. Here I tested the null hypothesis that certain group of symbionts sampled from different geographical locations are derived from a single evolutionary lineage using a nested clade analysis (NCA). I analyzed a total of 174 ITS1 sequences from GenBank and pooled them into 74 ITS1 distinct haplotypes. Using these haplotypes, the statistical parsimony criterion produced 23 independent network trees, each one corresponding to a genetically independent evolving lineage. Some of these lineages revealed certain degree of specificity with some host groups at least at the phylum level. Within the previously described 28S-rDNA phylotype A, five ITS1 lineages were resolved. Phylotypes B and C resolved each in two ITS1 lineages. The highest ITS1 symbiont diversity was observed within the phylotype F, in which 11 lineages were resolved. Moreover, most of these lineages were associated uniquely with protist hosts from the group of foraminiferans. Here it is suggested that this high genetic diversity of endosymbionts associated with foraminiferans is linked with the evolution of soritacean foraminifera, which seems to have been driven by endosymbiosis. Lastly, the absence of genetic recombination presented in this study, suggest a lack of hybridisation at least among the major 28S-rDNA phylotypes within Symbiodinium-like dinoflagellates. This supports highly the idea that these phylotypes are indeed independent evolutionary units, which should be considered at least as different species. Whether they belong to the same genus or to different higher taxa still needs to be revised.}, }
@article {pmid12797987, year = {2002}, author = {Bernasconi, MV and Casati, S and Péter, O and Piffaretti, JC}, title = {Rhipicephalus ticks infected with Rickettsia and Coxiella in Southern Switzerland (Canton Ticino).}, journal = {Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases}, volume = {2}, number = {2}, pages = {111-120}, doi = {10.1016/s1567-1348(02)00092-8}, pmid = {12797987}, issn = {1567-1348}, mesh = {Animals ; Coxiella/*genetics ; DNA, Ribosomal ; Dogs/parasitology ; Gram-Negative Bacterial Infections/*epidemiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Rickettsia/*genetics ; Rickettsia Infections/*epidemiology ; Sequence Analysis, DNA ; Switzerland ; Ticks/classification/genetics/*microbiology ; }, abstract = {Ticks of the Rhipicephalus sanguineus species complex may be vector of various pathogens including Rickettsia conorii (the etiological agent of the Mediterranean spotted fever) and Coxiella burnetii (cause of the Query (Q) fever). R. sanguineus ticks have been imported in several parts of central and northern Europe, especially in environments such as kennels and houses providing the appropriate microclimatic conditions and the blood source necessary for their survival. Since 1940 these ticks have occasionally been recorded in Switzerland. In Ticino (the southern part of Switzerland), they have been reported since 1980 and their probable establishment in this area has been suggested in the '90s. By means of PCR and direct sequencing, we tested the identity of these ticks (using 12S rDNA gene) and the occurrence of Rickettsia spp. (using 16S rDNA, gltA and OmpA genes) as well as Coxiella sp. (using 16S rDNA). The results indicated that in Ticino, two different tick species coexist, i.e. R. sanguineus sensu stricto and Rhipicephalus turanicus. A few individuals of R. sanguineus sensu stricto are infected with Rickettsia massiliae/Bar29, which are strains of unknown pathogenicity. Coxiella sp., an endosymbiont of Rhipicephalus ticks, has also been identified in both tick species. Due to climatic changes towards global warming, imported tick species may therefore adapt to new area and might be considered as epidemiological markers for a number of infectious agents transmitted by them.}, }
@article {pmid12791133, year = {2003}, author = {Wilcox, JL and Dunbar, HE and Wolfinger, RD and Moran, NA}, title = {Consequences of reductive evolution for gene expression in an obligate endosymbiont.}, journal = {Molecular microbiology}, volume = {48}, number = {6}, pages = {1491-1500}, doi = {10.1046/j.1365-2958.2003.03522.x}, pmid = {12791133}, issn = {0950-382X}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Bacterial Proteins/genetics/metabolism ; Base Sequence ; Buchnera/*genetics/physiology ; Escherichia coli/genetics/metabolism ; *Evolution, Molecular ; Gene Expression Profiling ; *Gene Expression Regulation, Bacterial ; Gene Rearrangement ; *Genome, Bacterial ; Heat-Shock Response ; Molecular Sequence Data ; Oligonucleotide Array Sequence Analysis ; Proteome ; *Symbiosis ; *Transcription, Genetic ; }, abstract = {The smallest cellular genomes are found in obligate symbiotic and pathogenic bacteria living within eukaryotic hosts. In comparison with large genomes of free-living relatives, these reduced genomes are rearranged and have lost most regulatory elements. To test whether reduced bacterial genomes incur reduced regulatory capacities, we used full-genome microarrays to evaluate transcriptional response to environmental stress in Buchnera aphidicola, the obligate endosymbiont of aphids. The 580 genes of the B. aphidicola genome represent a subset of the 4500 genes known from the related organism, Escherichia coli. Although over 20 orthologues of E. coli heat stress (HS) genes are retained by B. aphidicola, only five were differentially expressed after near-lethal heat stress treatments, and only modest shifts were observed. Analyses of upstream regulatory regions revealed loss or degradation of most HS (sigma32) promoters. Genomic rearrangements downstream of an intact HS promoter yielded upregulation of a functionally unrelated and an inactivated gene. Reanalyses of comparable experimental array data for E. coli and Bacillus subtilis revealed that genome-wide differential expression was significantly lower in B. aphidicola. Our demonstration of a diminished stress response validates reports of temperature sensitivity in B. aphidicola and suggests that this reduced bacterial genome exhibits transcriptional inflexibility.}, }
@article {pmid12777624, year = {2003}, author = {Archibald, JM and Rogers, MB and Toop, M and Ishida, K and Keeling, PJ}, title = {Lateral gene transfer and the evolution of plastid-targeted proteins in the secondary plastid-containing alga Bigelowiella natans.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {100}, number = {13}, pages = {7678-7683}, pmid = {12777624}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Cell Lineage ; Chlamydomonas reinhardtii/metabolism ; Chlorophyta/genetics ; DNA, Complementary/metabolism ; Databases as Topic ; Eukaryota/*genetics/metabolism ; *Evolution, Molecular ; Gene Library ; *Gene Transfer, Horizontal ; Molecular Sequence Data ; Phylogeny ; Plastids/*genetics/metabolism ; Sequence Homology, Amino Acid ; }, abstract = {Chlorarachniophytes are amoeboflagellate algae that acquired photosynthesis secondarily by engulfing a green alga and retaining its plastid (chloroplast). An important consequence of secondary endosymbiosis in chlorarachniophytes is that most of the nuclear genes encoding plastid-targeted proteins have moved from the nucleus of the endosymbiont to the host nucleus. We have sequenced and analyzed 83 cDNAs encoding 78 plastid-targeted proteins from the model chlorarachniophyte Bigelowiella natans (formerly Chlorarachnion sp. CCMP621). Phylogenies inferred from the majority of these genes are consistent with a chlorophyte green algal origin. However, a significant number of genes (approximately 21%) show signs of having been acquired by lateral gene transfer from numerous other sources: streptophyte algae, red algae (or algae with red algal endosymbionts), as well as bacteria. The chlorarachniophyte plastid proteome may therefore be regarded as a mosaic derived from various organisms in addition to the ancestral chlorophyte plastid. In contrast, the homologous genes from the chlorophyte Chlamydomonas reinhardtii do not show any indications of lateral gene transfer. This difference is likely a reflection of the mixotrophic nature of Bigelowiella (i.e., it is photosynthetic and phagotrophic), whereas Chlamydomonas is strictly autotrophic. These results underscore the importance of lateral gene transfer in contributing foreign proteins to eukaryotic cells and their organelles, and also suggest that its impact can vary from lineage to lineage.}, }
@article {pmid12777518, year = {2003}, author = {Dale, C and Wang, B and Moran, N and Ochman, H}, title = {Loss of DNA recombinational repair enzymes in the initial stages of genome degeneration.}, journal = {Molecular biology and evolution}, volume = {20}, number = {8}, pages = {1188-1194}, doi = {10.1093/molbev/msg138}, pmid = {12777518}, issn = {0737-4038}, support = {GM56120/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Coleoptera/microbiology ; *DNA Repair Enzymes/genetics/metabolism ; DNA, Bacterial/analysis/genetics/isolation &amp; purification ; DNA, Ribosomal/genetics ; DNA-Binding Proteins/genetics/metabolism ; Enterobacteriaceae/*genetics/physiology ; Escherichia coli/genetics ; *Escherichia coli Proteins ; *Evolution, Molecular ; Gene Conversion ; Genes, Bacterial ; *Genome, Bacterial ; Phylogeny ; Rec A Recombinases/genetics/metabolism ; *Recombination, Genetic ; Symbiosis/*genetics ; rRNA Operon ; }, abstract = {Many obligate intracellular pathogens and symbionts undergo genome degeneration during long-term association with eukaryotic hosts; however, very little is known about genome changes that occur in the initial stages of such intracellular associations. By focusing on a clade of bacteria that have recently established symbiotic associations with insect hosts, we have identified events that may contribute to the reduction and degeneration of symbiont genomes. Unlike virtually all other bacteria, the obligate symbionts of maize and rice weevils each display substantial sequence divergence between multiple copies of their rDNA genes, resulting from a reduction in the efficacy of recombinational gene conversion, coincident with the inactivation of the recombinational repair gene recF in the common ancestor of both symbionts. The maize weevil endosymbiont also lacks a functional recA, resulting in further reduction in the efficacy of gene conversion between paralogous rDNAs and in a novel IS-mediated deletion in a 23S rDNA gene. Similar events may be pervasive during the evolution of symbiosis because symbiont genomes typically lack recombinational repair genes and have reduced numbers of ribosomal operons.}, }
@article {pmid12770389, year = {1999}, author = {Nakabachi, A and Ishikawa, H}, title = {Provision of riboflavin to the host aphid, Acyrthosiphon pisum, by endosymbiotic bacteria, Buchnera.}, journal = {Journal of insect physiology}, volume = {45}, number = {1}, pages = {1-6}, doi = {10.1016/s0022-1910(98)00104-8}, pmid = {12770389}, issn = {1879-1611}, abstract = {Differential cDNA display and quantitative RT-PCR suggested that the riboflavin synthase complex of the aphid endosymbiont, Buchnera, is active only when the symbiotic system is maintained and well organized in young hosts. Since this finding suggested the provision of riboflavin by Buchnera, we examined the effect of dietary riboflavin on the performance of symbiotic and aposymbiotic aphids using chemically-defined diets. Our results indicate: (1) dietary riboflavin is slightly detrimental to young, symbiotic aphids; (2) dietary riboflavin is essential to aposymbiotic aphids; (3) dietary riboflavin remarkably improves the performance of aposymbiotic aphids. These results strongly suggest that young, symbiotic aphids are provided with riboflavin by their endosymbionts, Buchnera.}, }
@article {pmid12770078, year = {2002}, author = {Rahbé, Y and Digilio, MC and Febvay, G and Guillaud, J and Fanti, P and Pennacchio, F}, title = {Metabolic and symbiotic interactions in amino acid pools of the pea aphid, Acyrthosiphon pisum, parasitized by the braconid Aphidius ervi.}, journal = {Journal of insect physiology}, volume = {48}, number = {5}, pages = {507-516}, doi = {10.1016/s0022-1910(02)00053-7}, pmid = {12770078}, issn = {1879-1611}, abstract = {Aphidius ervi Haliday (Hymenoptera, Braconidae) is an endophagous parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera, Aphididae). This parasitoid strongly redirects host reproduction and metabolism to favour nutrition and development of its juvenile stages. Parasite-regulated biosynthesis and mobilization of nitrogen metabolites determine a significant increase of host nutritional suitability. The aim of the present study was mainly to investigate the temporal changes of A. pisum amino acid pools, as affected by A. ervi parasitism, and to assess the role of the aphid bacterial endosymbiont Buchnera in determining the observed changes. In parasitized aphids, we observed a very significant increase in total free amino acids, compared with synchronous non-parasitized controls, starting from day 4 after parasitization (+51%). This trend culminated with more than doubling the control value (+152%) on day 6 after parasitization. However, a significant "parasitism" effect was observed only for 10 of the 28 amino acids detected. Tyrosine accumulation was the most prominent parasitoid-induced alteration, with a fourfold increase over control levels registered on day 6. In parasitized hosts, the amino acid biosynthetic capacity of Buchnera was unaltered, or even enhanced for the phenolic pool, and contributed greatly to the definition and maintainance of host free amino acid pools. The hypertyrosinemic syndrome was not dependent on food supply of the aromatic nucleus but was induced by parasitism, which likely enhanced the aromatic shuttle mediating phenylalanine transfer from bacteria to the host tissues, where tyrosine conversion occurs. This process is likely associated with a selective disruption of the host's functions requiring tyrosine, leading to the remarkable accumulation of this amino acid. The possible mechanisms determining these parasitism-induced host alterations, and their nutritional significance for the developing parasitoid larva, are discussed.}, }
@article {pmid12760642, year = {2003}, author = {Gorham, CH and Fang, QQ and Durden, LA}, title = {Wolbachia endosymbionts in fleas (Siphonaptera).}, journal = {The Journal of parasitology}, volume = {89}, number = {2}, pages = {283-289}, doi = {10.1645/0022-3395(2003)089[0283:WEIFS]2.0.CO;2}, pmid = {12760642}, issn = {0022-3395}, mesh = {Animals ; Cats ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Dogs ; Female ; Georgia ; Male ; New York ; Opossums ; Phylogeny ; Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sciuridae ; Sequence Alignment ; Sigmodontinae ; Siphonaptera/classification/*microbiology ; *Symbiosis ; Wolbachia/classification/genetics/isolation &amp; purification/*physiology ; }, abstract = {Intracellular endosymbionts, Wolbachia spp., have been reported in many different orders of insects and in nematodes but not previously in fleas. This is the first conclusive report of Wolbachia spp. within members of the Siphonaptera. Using nested polymerase chain reaction (PCR) targeting of the 16S ribosomal RNA gene, we screened for Wolbachia spp. in fleas collected from 3 counties in Georgia and 1 in New York. The prevalence of Wolbachia spp. detected varied among the 6 different species screened: 21% in the cat flea Ctenocephalides felis (n = 604), 7% in the dog flea C. canis (n = 28), 25% in Polygenus gwyni (n = 8), 80% in Orchopeas howardi (n = 15), 94% in Pulex simulans (n = 255), and 24% in the sticktight flea Echidnophaga gallinacea (n = 101). Wolbachia spp. infection in fleas was confirmed by sequencing positive PCR products, comparing sequenced 16S ribosomal DNA (rDNA) with Wolbachia spp. sequences in GenBank using BLAST search, and subjecting sequence data to phylogenetic analysis. For further confirmation, 16S rDNA-positive samples were reamplified using the wsp gene.}, }
@article {pmid12756279, year = {2003}, author = {Fehrenbacher, K and Huckaba, T and Yang, HC and Boldogh, I and Pon, L}, title = {Actin comet tails, endosomes and endosymbionts.}, journal = {The Journal of experimental biology}, volume = {206}, number = {Pt 12}, pages = {1977-1984}, doi = {10.1242/jeb.00240}, pmid = {12756279}, issn = {0022-0949}, support = {GM45735/GM/NIGMS NIH HHS/United States ; GM66307/GM/NIGMS NIH HHS/United States ; }, mesh = {Actins/*physiology ; Cell Movement/physiology ; Cytoskeleton/*physiology ; Organelles/*physiology ; }, abstract = {The Arp2/3 complex consists of seven highly conserved and tightly associated subunits, two of which are the actin-related proteins Arp2 and Arp3. One of the best-studied functions of the Arp2/3 complex is to stimulate actin nucleation and force production at the leading edge of motile cells. What is now clear is that Arp2/3-complex-mediated force production drives many intracellular movements, including movement of bacterial pathogens in infected host cells, internalization of extracellular materials via phagocytosis and endocytosis, and movement of mitochondria during cell division in budding yeast. Here, we describe recent advances in the mechanisms underlying Arp2/3 complex-driven intracellular movement.}, }
@article {pmid12753227, year = {2003}, author = {Plague, GR and Dale, C and Moran, NA}, title = {Low and homogeneous copy number of plasmid-borne symbiont genes affecting host nutrition in Buchnera aphidicola of the aphid Uroleucon ambrosiae.}, journal = {Molecular ecology}, volume = {12}, number = {4}, pages = {1095-1100}, doi = {10.1046/j.1365-294x.2003.01782.x}, pmid = {12753227}, issn = {0962-1083}, support = {GM00708-02/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*genetics ; DNA Primers ; *Genetic Variation ; Leucine/biosynthesis/*genetics ; Polymerase Chain Reaction ; *Symbiosis ; Tryptophan/biosynthesis/*genetics ; United States ; }, abstract = {The bacterial endosymbiont of aphids, Buchnera aphidicola, often provides amino acids to its hosts. Plasmid amplification of leucine (leuABCD) and tryptophan (trpEG) biosynthesis genes may be a mechanism by which some Buchnera over-produce these nutrients. We used quantitative polymerase chain reaction to assess the leuABCD/trpEG copy variability within Uroleucon ambrosiae, an aphid with a wide diet breadth and range. Both leuABCD and trpEG abundances are: (i) similar for aphids across 15 populations, and (ii) low compared to Buchnera from other aphid species (particularly trpEG). Consequently, the plasmid location of trpEG combined with Buchnera's chromosomal polyploidy may functionally limit, rather than increase, tryptophan production within Uroleucon ambrosiae.}, }
@article {pmid12729582, year = {2003}, author = {Frank, S and Robert, EG and Youle, RJ}, title = {Scission, spores, and apoptosis: a proposal for the evolutionary origin of mitochondria in cell death induction.}, journal = {Biochemical and biophysical research communications}, volume = {304}, number = {3}, pages = {481-486}, doi = {10.1016/s0006-291x(03)00620-x}, pmid = {12729582}, issn = {0006-291X}, mesh = {*Apoptosis ; Bacteria/ultrastructure ; Bacterial Physiological Phenomena ; Bacterial Proteins/metabolism ; *Biological Evolution ; Cell Death ; *Cytoskeletal Proteins ; Mitochondria/classification/*physiology/ultrastructure ; *Models, Biological ; Phylogeny ; Spores, Bacterial/ultrastructure ; }, abstract = {Mitochondria fragment prior to caspase activation during many pathways of apoptosis. Inhibition of the machinery that normally regulates mitochondrial morphology in healthy cells inhibits the fission that occurs during apoptosis and actually delays the process of cell death. Interestingly, there are certain parallels between mitochondrial fission and bacterial sporulation. As bacterial sporulation can be considered a stress response we suggest that a primordial stress response of endosymbiont mitochondrial progenitors may have been adopted for the stress response of early eukaryotes. Thus, the mitochondrial fission process may represent an early stress response of primitive mitochondria that could have integrated the stress signals and acted as an initial sensor for the eukaryotic response system. The fact that mitochondria fragment during apoptosis using the machinery descended from or that superceded the bacterial stress response of sporulation is consistent with this hypothesis. This hypothesis would explain why what is generally considered the "power house" of the cell came to integrate the cell death response and regulate apoptosis.}, }
@article {pmid12725815, year = {2003}, author = {Karatayev, AY and Mastitsky, SE and Burlakova, LE and Molloy, DP and Vezhnovets, GG}, title = {Seasonal dynamics of endosymbiotic ciliates and nematodes in Dreissena polymorpha.}, journal = {Journal of invertebrate pathology}, volume = {83}, number = {1}, pages = {73-82}, doi = {10.1016/s0022-2011(03)00043-0}, pmid = {12725815}, issn = {0022-2011}, mesh = {Animals ; Bivalvia/*parasitology ; Ciliophora/*physiology ; Ciliophora Infections/*epidemiology/physiopathology ; Host-Parasite Interactions ; Nematoda/*physiology ; Nematode Infections/*epidemiology/physiopathology ; Prevalence ; Republic of Belarus ; Seasons ; Symbiosis ; Temperature ; }, abstract = {We report the results of a two-year study in the Svisloch River (Minsk, Belarus) on the dynamics of infection in Dreissena polymorpha by nematodes and three ciliate species Conchophthirus acuminatus, Ophryoglena sp., and Ancistrumina limnica. Although these endosymbionts were present in most of the samples, their prevalence and infection intensity differed significantly. C. acuminatus and A. limnica infection intensities in both years of the study had a maximum in summer and were positively correlated with water temperature. In contrast, Ophryoglena sp. and nematode infection intensities were considerably lower in summer versus winter and were negatively correlated with temperature. In the first long-term study to monitor the size and reproductive rate of C. acuminatus, we found that mean length was negatively correlated with temperature and that temperature was positively correlated with asexual reproduction, with a peak of cell division in April as water temperatures increased.}, }
@article {pmid12725810, year = {2003}, author = {Ebbert, MA and Marlowe, JL and Burkholder, JJ}, title = {Protozoan and intracellular fungal gut endosymbionts in Drosophila: prevalence and fitness effects of single and dual infections.}, journal = {Journal of invertebrate pathology}, volume = {83}, number = {1}, pages = {37-45}, doi = {10.1016/s0022-2011(03)00033-8}, pmid = {12725810}, issn = {0022-2011}, mesh = {Animals ; Ascomycota/*physiology ; Drosophila/growth &amp; development/*parasitology ; Female ; Host-Parasite Interactions/physiology ; Intestines/parasitology ; Male ; Mycoses/epidemiology/*physiopathology ; Prevalence ; Protozoan Infections/epidemiology/*physiopathology ; Pupa ; Sex Factors ; Species Specificity ; Symbiosis ; Trypanosomatina/*physiology ; }, abstract = {We report on the effect of single and mixed infections with two gut symbionts, trypanosomatids and the intracellular fungus Coccidiascus legeri, on the life history of their host, Drosophila melanogaster. We also provide the first report on the prevalence of C. legeri in natural populations of Drosophila. Prevalence overall was low (3.4%), and differed with host species, but persisted from the first to the second year of our survey. We documented delayed pupation in flies exposed to trypanosomatids, but larvae exposed to the fungus eclosed more quickly than controls. Larvae exposed to mixed infections pupated more slowly, but eclosed more quickly than controls.}, }
@article {pmid12716997, year = {2003}, author = {Lo, N and Bandi, C and Watanabe, H and Nalepa, C and Beninati, T}, title = {Evidence for cocladogenesis between diverse dictyopteran lineages and their intracellular endosymbionts.}, journal = {Molecular biology and evolution}, volume = {20}, number = {6}, pages = {907-913}, doi = {10.1093/molbev/msg097}, pmid = {12716997}, issn = {0737-4038}, mesh = {Animals ; Bacteria/genetics ; Cockroaches/classification/*genetics/microbiology ; DNA, Ribosomal/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Bacteria of the genus Blattabacterium are intracellular symbionts that reside in specialized cells of cockroaches and the termite Mastotermes darwiniensis. They appear to be obligate mutualists, and are transmitted vertically in the eggs. Such characteristics are expected to lead to equivalent phylogenies for host and symbiont, and we tested this hypothesis using recently accumulated data on relationships among termites and cockroaches and their Blattabacterium spp. Host and symbiont topologies were found to be highly similar, and various tests indicated that they were not statistically different. A close relationship between endosymbionts from termites and members of the wood-feeding cockroach genus Cryptocercus was found, supporting the hypothesis that the former evolved from subsocial, wood-dwelling cockroaches. The majority of the Blattabacterium spp. sequences appear to have undergone similar rates of evolution since their divergence from a common ancestor, and an estimate of this rate was determined based on early Cretaceous host fossils. The results support the idea that the stem group of modern cockroaches radiated sometime between the late Jurassic and early Cretaceous-not the Carboniferous, as has been suggested on the basis of roach-like fossils from this epoch.}, }
@article {pmid12713468, year = {2003}, author = {Scott, KM}, title = {A delta13C-based carbon flux model for the hydrothermal vent chemoautotrophic symbiosis Riftia pachyptila predicts sizeable CO(2) gradients at the host-symbiont interface.}, journal = {Environmental microbiology}, volume = {5}, number = {5}, pages = {424-432}, doi = {10.1046/j.1462-2920.2003.00416.x}, pmid = {12713468}, issn = {1462-2912}, mesh = {Animals ; Annelida/*physiology ; Biomass ; Carbon Dioxide/*metabolism ; Carbon Isotopes/*metabolism ; Mathematics ; Models, Biological ; Proteobacteria/*metabolism ; Seawater ; *Symbiosis ; }, abstract = {The chemoautotrophic symbiosis Riftia pachyptila has extremely 13C-enriched delta13C values. Neither isotopic discrimination by the RubisCO enzyme of their bacterial endosymbionts, nor the delta13C value of CO2 at their hydrothermal vent habitat, suffice to explain biomass delta13C values in this organism, which range from - 9 to - 16 per thousand. However, these 13C-enriched delta13C values are consistent with the presence of 13C-enriched CO2 within the symbiont cytoplasm. Such a 13C-enriched pool of CO2 is expected when the rate of CO2 fixation by RubisCO, which fixes 12CO2 more rapidly than 13CO2, approaches the rate of exchange between intracellular and extracellular CO2 pools. Rapid CO2 fixation rates will also generate concentration gradients between these two pools. In order to estimate the size of these concentration gradients, an equation was derived, which describes the delta13C of tubeworm biomass in terms of the size of the CO2 gradient between the hydrothermal vent environment and the symbiont cytoplasm. Using mass balance equations for CO2 exchange and fixation by the symbionts and the tubeworm host, this model predicts that a CO2 concentration gradient of up to 17-fold between the symbiont cytoplasm and the environment is sufficient to explain even the most 13C-enriched R. pachyptila biomass. This model illustrates how both physical and enzymatic factors can act to influence the delta13C of intracellular CO2, which, in turn, highlights the danger of assigning a carbon fixation pathway to an autotroph based solely on its biomass delta13C value.}, }
@article {pmid12701381, year = {2002}, author = {Baldo, L and Bartos, JD and Werren, JH and Bazzocchi, C and Casiraghi, M and Panelli, S}, title = {Different rates of nucleotide substitutions in Wolbachia endosymbionts of arthropods and nematodes: arms race or host shifts?.}, journal = {Parassitologia}, volume = {44}, number = {3-4}, pages = {179-187}, pmid = {12701381}, issn = {0048-2951}, mesh = {Animals ; Arthropods/*microbiology ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; Base Sequence ; Codon/genetics ; DNA-Binding Proteins/genetics ; *Evolution, Molecular ; Fushi Tarazu Transcription Factors ; Genes, Bacterial ; Homeodomain Proteins/genetics ; Likelihood Functions ; *Mutagenesis ; Nematoda/*microbiology ; Phylogeny ; Selection, Genetic ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; Species Specificity ; Wolbachia/*genetics/ultrastructure ; }, abstract = {The genus Wolbachia encompasses intracellular bacteria found in arthropods and in filarial nematodes. In arthropods, Wolbachia is primarily a reproductive parasite and shows relatively frequent horizontal transfer between host species, while in nematodes it appears to be a mutualist and is strictly vertically transmitted. We can expect that different selective pressures are acting on their genomes. Here we present an analysis of three Wolbachia genes, wsp, ftsZ and dnaA. In wsp of arthropod Wolbachia, an excess of non-synonymous substitutions was observed, providing evidence for positive selection. In nematode Wolbachia, no evidence for positive selection was found. Pressure for amino acid variation in wsp of arthropod Wolbachia could derive either from an arms race with the host or from the occurrence of more frequent hosts shifts due to horizontal transmission. In nematode Wolbachia, the lack of positively selected sites could result from the absence of an arms race, or from the homogeneity of the biochemical environment they exist in (ensured by strict vertical transmission). In ftsZ minor differences in substitution patterns were observed between arthropod and nematode Wolbachia, only in the 3'-portion of the gene. dnaA showed comparable patterns of variation in both lineages, with evidence for strong conservation.}, }
@article {pmid12700158, year = {2003}, author = {Wernegreen, JJ and Degnan, PH and Lazarus, AB and Palacios, C and Bordenstein, SR}, title = {Genome evolution in an insect cell: distinct features of an ant-bacterial partnership.}, journal = {The Biological bulletin}, volume = {204}, number = {2}, pages = {221-231}, doi = {10.2307/1543563}, pmid = {12700158}, issn = {0006-3185}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/*physiology ; Enterobacteriaceae/*genetics/physiology ; *Evolution, Molecular ; Genetics, Population ; *Genome ; *Phylogeny ; Symbiosis/*genetics ; }, abstract = {Bacteria that live exclusively within eukaryotic host cells include not only well-known pathogens, but also obligate mutualists, many of which occur in diverse insect groups such as aphids, psyllids, tsetse flies, and the ant genus Camponotus (Buchner, 1965; Douglas, 1998; Moran and Telang, 1998; Baumann et al., 2000; Moran and Baumann, 2000). In contrast to intracellular pathogens, these primary (P) endosymbionts of insects are required for the survival and reproduction of the host, exist within specialized host cells called bacteriocytes, and undergo stable maternal transmission through host lineages (Buchner, 1965; McLean and Houk, 1973). Due to their long-term host associations and close phylogenetic relationship with well-characterized enterobacteria (Fig. 1), P-endosymbionts of insects are ideal model systems to examine changes in genome content and architecture that occur in the context of beneficial, intracellular associations. Since these bacteria have not been cultured outside of the host cell, they are difficult to study with traditional genetic or physiological approaches. However, in recent years, molecular and computational approaches have provided important insights into their genetic diversity and ecological significance. This review describes some recent insights into the evolutionary genetics of obligate insect-bacteria symbioses, with a particular focus on an intriguing association between the bacterial endosymbiont Blochmannia and its ant hosts.}, }
@article {pmid12700156, year = {2003}, author = {Gast, RJ and Beaudoin, DJ and Caron, DA}, title = {Isolation of symbiotically expressed genes from the dinoflagellate symbiont of the solitary radiolarian Thalassicolla nucleata.}, journal = {The Biological bulletin}, volume = {204}, number = {2}, pages = {210-214}, doi = {10.2307/1543561}, pmid = {12700156}, issn = {0006-3185}, mesh = {Animals ; Dinoflagellida/*genetics/physiology ; Eukaryota/*microbiology ; Gene Expression/genetics/physiology ; Genomics ; Nucleic Acid Hybridization ; RNA/genetics/*isolation &amp; purification ; Symbiosis/*genetics ; }, abstract = {Symbiotic associations are fundamental to the survival of many organisms on Earth. The ability of the symbiont to perform key biochemical functions often allows the host to occupy environments that it would otherwise find inhospitable. This can have profound impacts upon the diversification and distribution of the host. Cellular organelles (chloroplasts and mitochondria) represent the final stages of integration of endosymbionts. These organelles were of critical importance to the evolution and success of eukaryotic lineages on our planet because they allowed the host cells to harness light energy and to thrive in the presence of oxygen. The marine photosymbiotic associations that we study represent an earlier stage in the process of symbiont integration-one in which the photobiont can still be removed from the host and exist on its own. These systems are of interest to us for two reasons. First, they are ecologically important in the marine environment where they occur. These organisms form zones of photosynthetic production in oceanic regions typically low in nutrients. Second, investigation of these interactions may shed light on the molecular and evolutionary mechanisms involved in the integration of cells and their genomes.}, }
@article {pmid12694905, year = {2003}, author = {Motta, MC and de Souza, W and Thiry, M}, title = {Immunocytochemical detection of DNA and RNA in endosymbiont-bearing trypanosomatids.}, journal = {FEMS microbiology letters}, volume = {221}, number = {1}, pages = {17-23}, doi = {10.1016/S0378-1097(03)00087-9}, pmid = {12694905}, issn = {0378-1097}, mesh = {Animals ; Bacteria/chemistry ; Cell Cycle ; Crithidia/chemistry/*cytology/microbiology/virology ; DNA Nucleotidylexotransferase ; DNA, Bacterial/analysis ; DNA, Kinetoplast/analysis ; DNA, Protozoan/*analysis ; Immunohistochemistry ; RNA, Protozoan/*analysis ; Symbiosis ; Trypanosomatina/chemistry/*cytology/microbiology ; Virion/chemistry ; }, abstract = {Research about the kinetoplast of trypanosomatids has yielded valuable information about the organization of extranuclear structure. However, the ultrastructural localization of nucleic acids within these protozoa remains uncertain. We have applied cytochemical and immunocytochemical approaches to precisely identify DNA and RNA in lower endosymbiont-bearing trypanosomatids. Using the Terminal deoxynucleotidyl Transferase (TdT) immunogold technique, we showed that nuclear DNA is seen associated with the nuclear envelope during the trypanosomatid cell cycle. By combining the TdT technique with the acetylation method, which improves the contrast between structures containing fibrils and granules, we have demonstrated that the nucleolus of endosymbiont-bearing trypanosomatids is composed of two constituents: a granular component and a DNA-positive fibrillar zone. Moreover, we revealed that DNA of endosymbiotic bacteria consisted of electron-dense filaments which are usually in close contact with the prokaryote envelope. Using a Lowicryl post-embedding immunogold labeling procedure with anti-RNA antibodies, we showed the presence of RNA not only over the cytoplasm, the interchromatin spaces and the nucleolus, but also over the kinetoplast and virus-like particles present in Crithidia desouzai.}, }
@article {pmid12694284, year = {2003}, author = {McGovern, TM and Hellberg, ME}, title = {Cryptic species, cryptic endosymbionts, and geographical variation in chemical defences in the bryozoan Bugula neritina.}, journal = {Molecular ecology}, volume = {12}, number = {5}, pages = {1207-1215}, doi = {10.1046/j.1365-294x.2003.01758.x}, pmid = {12694284}, issn = {0962-1083}, mesh = {Animals ; Atlantic Ocean ; Base Sequence ; Bryozoa/*genetics/*microbiology/physiology ; Cluster Analysis ; DNA Primers ; DNA, Mitochondrial/genetics ; Gammaproteobacteria/chemistry/*genetics ; *Genetic Variation ; Geography ; Likelihood Functions ; Molecular Sequence Data ; Phylogeny ; Symbiosis/*physiology ; }, abstract = {Molecular markers often offer the only means to discriminate between species and to elucidate the specificity of many community interactions, both of which are key to the understanding of ecological patterns. Western Atlantic populations of the bryozoan Bugula neritina vary in the palatability of their larvae to predators: individuals south of Cape Hatteras produce chemical deterrents to fish predators that are absent in more northern individuals. We use mitochondrial cytochrome oxidase c subunit I (COI) sequences to show that the differences in palatability between populations correlate with the geographical distributions of two cryptic species within B. neritina. Furthermore, these cryptic species differ in their associations with bacteria that may confer chemical resistance to predation. Small subunit rRNA primers specific to a subset of gamma-proteobacteria amplified only the bacterium Endobugula sertula from the southern cryptic species. Endobugula sertula produces a family of chemical compounds (bryostatins) that may deter predators of its animal host. In contrast, the same primers amplified an array of gamma-proteobacteria from the unprotected northern cryptic bryozoan species, but never E. sertula. In combination, these findings suggest that the geographical variation in palatability observed in the larvae of B. neritina is not the result of local adaptation of a single species to regions of differing predation pressure, but rather results from the comparison of cryptic species that differ in the presence or absence of a bacterium that may provide protection against predators. The ability to identify the cryptic Bugula species and their differing relationships with bacterial associates provides an example of the important role molecular techniques may play in addressing ecological questions.}, }
@article {pmid12693853, year = {2003}, author = {Hirunkanokpun, S and Kittayapong, P and Cornet, JP and Gonzalez, JP}, title = {Molecular evidence for novel tick-associated spotted fever group rickettsiae from Thailand.}, journal = {Journal of medical entomology}, volume = {40}, number = {2}, pages = {230-237}, doi = {10.1603/0022-2585-40.2.230}, pmid = {12693853}, issn = {0022-2585}, mesh = {Animals ; Base Sequence ; Cattle/microbiology ; DNA Primers ; Dogs/microbiology ; Genotype ; Humans ; Phylogeny ; Rats/microbiology ; Rickettsia/*classification/*genetics/isolation &amp; purification ; Rickettsia Infections/*epidemiology ; Thailand/epidemiology ; Ticks/*microbiology ; }, abstract = {Ticks are of considerable medical and veterinary importance because they directly harm the host through their feeding action and indirectly through vectoring many bacterial pathogens. Despite many ticks being known from Thailand, very little is known about the bacteria they may harbor. We report here the results of a survey of tick-associated bacteria in Thailand. A total of 334 individuals representing 14 species of ticks in five genera were collected from 10 locations in Thailand and were examined for the human pathogens, Borrelia, Francisella, Rickettsia, and the common arthropod endosymbionts, Wolbachia, by polymerase chain reaction (PCR) assay using specific primers. Rickettsial DNA was detected in 30% (9/30) of Amblyomma testudinarium (Koch, 1844) collected from Khao Yai National Park, Nakhon Nayok Province and 16.84% (16/95) of Hemaphysalis ornithophila (Hoogstraal and Kohls, 1959) collected from Khao Yai National Park, Nakhon Nayok Province and Khao Ang Rue Nai Wildlife Sanctuary, Chachoengsao Province. Rickettsial DNA was not detected in any of the other tick species and no DNA of Borrelia, Francisella, or Wolbachia was detected in any of 14 tick species. Phylogenetic relationships among the rickettsiae detected in this study and those of other rickettsiae were inferred from comparison of sequences of the 17-kDa antigen gene, the citrate synthase gene (gltA), and the 190-kDa outer membrane protein gene (ompA). Results indicated that the three Thai rickettsiae detected in this study represent new rickettsial genotypes and form a separate cluster among the spotted fever group rickettsiae.}, }
@article {pmid12684880, year = {2003}, author = {Suganuma, N and Nakamura, Y and Yamamoto, M and Ohta, T and Koiwa, H and Akao, S and Kawaguchi, M}, title = {The Lotus japonicus Sen1 gene controls rhizobial differentiation into nitrogen-fixing bacteroids in nodules.}, journal = {Molecular genetics and genomics : MGG}, volume = {269}, number = {3}, pages = {312-320}, pmid = {12684880}, issn = {1617-4615}, mesh = {Chromosome Mapping ; Leghemoglobin/metabolism ; Lotus/*genetics/metabolism/microbiology ; Nitrogen Fixation/*genetics/physiology ; Nitrogenase/metabolism ; Plant Proteins/*genetics/metabolism ; Rhizobiaceae/metabolism ; }, abstract = {A Lotus japonicus mutant, Ljsym75, which forms ineffective symbiotic nodules and defines a new locus involved in the process of nitrogen fixation, was characterized in detail in order to identify the stage of developmental arrest of the nodules. No nitrogen-fixing activity was detectable in Ljsym75 nodules at any stage during plant development, and plant growth was markedly retarded. Ljsym75 plants formed twice as many nodules as the wild-type Gifu, and this phenotype was not influenced by the application of low concentrations of nitrate. Although the ineffective nodules formed on Ljsym75 were anatomically similar to effective Gifu nodules, Ljsym75 nodules senesced prematurely. Microscopic examination revealed that bacteria endocytosed into Ljsym75 nodules failed to differentiate into bacteroids. Moreover, the bacteria contained no nitrogenase proteins, whereas leghemoglobin was detected in the cytosol of the nodules. These results indicate that Ljsym75 is required for bacterial differentiation into nitrogen-fixing bacteroids in nodules, and thus the Ljsym75 gene was renamed sen1 (for stationary endosymbiont nodule). Linkage analysis using DNA markers showed that Sen1 is located on chromosome 4.}, }
@article {pmid12684759, year = {2003}, author = {Hoerauf, A and Mand, S and Fischer, K and Kruppa, T and Marfo-Debrekyei, Y and Debrah, AY and Pfarr, KM and Adjei, O and Büttner, DW}, title = {Doxycycline as a novel strategy against bancroftian filariasis-depletion of Wolbachia endosymbionts from Wuchereria bancrofti and stop of microfilaria production.}, journal = {Medical microbiology and immunology}, volume = {192}, number = {4}, pages = {211-216}, pmid = {12684759}, issn = {0300-8584}, mesh = {Adolescent ; Adult ; Animals ; Anti-Bacterial Agents/administration &amp; dosage/pharmacology/*therapeutic use ; Doxycycline/administration &amp; dosage/pharmacology/*therapeutic use ; Elephantiasis, Filarial/*drug therapy/*parasitology ; Female ; Filaricides/administration &amp; dosage/pharmacology/therapeutic use ; Ghana ; Humans ; Ivermectin/administration &amp; dosage/pharmacology/therapeutic use ; Male ; Microfilariae/drug effects ; Middle Aged ; Parasitemia/drug therapy ; Symbiosis ; Wolbachia/*drug effects/growth &amp; development ; Wuchereria bancrofti/drug effects/growth &amp; development/*microbiology ; }, abstract = {Chemotherapy of onchocerciasis by doxycycline, which targets symbiotic Wolbachia endobacteria, has been shown to result in a long-term sterility of adult female worms and corresponding absence of microfilariae. It represents an additional chemotherapeutic approach. The aim of this study was to determine whether a similar regimen would also show efficacy against Wuchereria bancrofti. Ghanaian individuals (n=93) with lymphatic filariasis and a minimum microfilaremia of 40 microfilariae/ml were included in a treatment study consisting of four arms: (1) doxycycline 200 mg/day for 6 weeks; (2) doxycycline as in (1), followed by a single dose of ivermectin after 4 months; (3) ivermectin only; or (4) no treatment during observation period of 1 year (ivermectin at the end of the study). Doxycycline treatment resulted in a 96% loss of Wolbachia, as determined by real time PCR from microfilariae. After 12 months, doxycycline had led to a 99% reduction of microfilaremia when given alone, and to a complete amicrofilaremia together with ivermectin. In contrast, after ivermectin treatment alone a significant presence of microfilariae remained (9% compared to pretreatment), as known from other studies. This study shows that doxycycline is also effective in depleting Wolbachia from W. bancrofti. It is likely that the mechanism of doxycycline is similar to that in other filarial species, i.e., a predominant blockade of embryogenesis, leading to a decline of microfilariae according to their half-life. This could render doxycycline treatment an additional tool for the treatment of microfilaria-associated diseases in bancroftian filariasis, such as tropical pulmonary eosinophilia and microfiluria.}, }
@article {pmid12683537, year = {2003}, author = {Vavre, F and Fouillet, P and Fleury, F}, title = {Between- and within-host species selection on cytoplasmic incompatibility-inducing Wolbachia in haplodiploids.}, journal = {Evolution; international journal of organic evolution}, volume = {57}, number = {2}, pages = {421-427}, doi = {10.1111/j.0014-3820.2003.tb00275.x}, pmid = {12683537}, issn = {0014-3820}, mesh = {Alleles ; Animals ; Biological Evolution ; Cytoplasm/microbiology ; Diploidy ; Female ; Genes, Insect ; Genetic Variation ; Haploidy ; Insecta/*genetics/*microbiology ; Male ; Models, Biological ; Reproduction/genetics ; Species Specificity ; Symbiosis/genetics/physiology ; Wolbachia/genetics/pathogenicity/*physiology ; }, abstract = {The most common effect of the endosymbiont Wolbachia is cytoplasmic incompatibility (CI), a form of postzygotic reproductive isolation that occurs in crosses where the male is infected by at least one Wolbachia strain that the female lacks. We revisited two puzzling features of Wolbachia biology: how Wolbachia can invade a new species and spread among populations, and how the association, once established in a host species, can evolve, with emphasis on the possible process of infection loss. These questions are particularly relevant in haplodiploid species, where males develop from unfertilized eggs, and females from fertilized eggs. When CI occurs in such species, fertilized eggs either die (female mortality type: FM), or develop into males (male development type: MD), raising one more question: how transition among CI types is possible. We reached the following conclusions: (1) the FM type is a better invader and should be retained preferentially after a new host is captured; (2) given the assumptions of the models, FM and MD types are selected on neither the bacterial side nor the host side; (3) selective pressures acting on both partners are more or less congruent in the FM type, but divergent in the MD type; (4) host and symbiont evolution can drive infection to extinction for all CI types, but the MD type is more susceptible to the phenomenon; and (5) under realistic conditions, transition from MD to FM type is possible. Finally, all these results suggest that the FM type should be more frequent than the MD type, which is consistent with the results obtained so far in haplodiploids.}, }
@article {pmid12676683, year = {2003}, author = {Hurtado, LA and Mateos, M and Lutz, RA and Vrijenhoek, RC}, title = {Coupling of bacterial endosymbiont and host mitochondrial genomes in the hydrothermal vent clam Calyptogena magnifica.}, journal = {Applied and environmental microbiology}, volume = {69}, number = {4}, pages = {2058-2064}, pmid = {12676683}, issn = {0099-2240}, mesh = {Animals ; Bivalvia/genetics/*microbiology ; DNA/analysis ; DNA, Bacterial/analysis ; DNA, Mitochondrial/genetics ; *Evolution, Molecular ; Gammaproteobacteria/*genetics/growth &amp; development ; Genetic Variation ; Genome ; Genome, Bacterial ; Hot Temperature ; Phylogeny ; Polymorphism, Genetic ; Seawater/microbiology ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The hydrothermal vent clam Calyptogena magnifica (Bivalvia: Vesicomyidae) depends for its nutrition on sulfur-oxidizing symbiotic bacteria housed in its gill tissues. This symbiont is transmitted vertically between generations via the clam's eggs; however, it remains uncertain whether occasionally symbionts are horizontally transmitted or acquired from the environment. If symbionts are transmitted strictly vertically through the egg cytoplasm, inheritance of symbiont lineages should behave as if coupled to the host's maternally inherited mitochondrial DNA. This coupling would be obscured, however, with low rates of horizontal or environmental transfers, the equivalent of recombination between host lineages. Population genetic analyses of C. magnifica clams and associated symbionts from eastern Pacific hydrothermal vents clearly supported the hypothesis of strictly maternal cotransmission. Host mitochondrial and symbiont DNA sequences were coupled in a clam population that was polymorphic for both genetic markers. These markers were not similarly coupled with sequence variation at a nuclear gene locus, as expected for a randomly mating sexual population. Phylogenetic analysis of the two cytoplasmic genes also revealed no evidence for recombination. The tight association between vesicomyid clams and their vertically transmitted bacterial endosymbionts is phylogenetically very young (<50 million years) and may serve as a model for the origin and evolution of eukaryotic organelles.}, }
@article {pmid12676551, year = {2003}, author = {Nakabachi, A and Ishikawa, H and Kudo, T}, title = {Extraordinary proliferation of microorganisms in aposymbiotic pea aphids, Acyrthosiphon pisum.}, journal = {Journal of invertebrate pathology}, volume = {82}, number = {3}, pages = {152-161}, doi = {10.1016/s0022-2011(03)00020-x}, pmid = {12676551}, issn = {0022-2011}, mesh = {Animals ; Aphids/metabolism/*microbiology ; Bacteria/*genetics/isolation &amp; purification ; Buchnera/genetics/isolation &amp; purification ; Chromatography, High Pressure Liquid ; DNA, Ribosomal/analysis ; Diet ; Fungi/*genetics/isolation &amp; purification ; Histamine/analysis ; *Phylogeny ; Polymerase Chain Reaction ; Symbiosis/physiology ; Vicia faba/*microbiology ; }, abstract = {Aposymbiotic pea aphids, which were deprived of their intracellular symbiotic bacterium, Buchnera, exhibit growth retardation and no fecundity. High performance liquid chromatographic (HPLC) analysis revealed that these aposymbiotic aphids, when reared on broad bean plants, accumulated a large amount of histamine. To assess the possibility of extraordinary proliferation of microorganisms other than Buchnera, we enumerated eubacteria and fungi in aphids using the real-time quantitative PCR method that targets genes encoding small-subunit rRNAs. The result showed that these microorganisms were extremely abundant in the aposymbiotic aphids reared on plants. Microbial communities in aposymbiotic aphids were further profiled by phylogenetic analysis of small-subunit rDNAs. Of 172 nonchimeric sequences of fungal 18S rDNAs, 138 (80.2%) belonged to the phylum Ascomycota. Among them, 21 clustered within a monophyletic group consisting of insect-pathogenic fungi and yeast-like symbionts of homopteran insects. Thirty-one (18.0%), two (1.2%), and one (0.6%) clones were clustered within the Basidiomycota, Zygomycota, and Oomycota, respectively. Of 167 nonchimeric sequences of eubacterial 16S rDNAs, 84 (50.3%) belonged to the gamma-subdivision of Proteobacteria to which most primary endosymbionts of insects and prolific histamine producers belong. Forty (24.0%), 25 (15.0%), 10 (6.0%), and five (3.0%) clones were clustered within alpha-Proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group, Actinobacteria, and beta-Proteobacteria, respectively. Three had no phylogenetic association with known taxonomic divisions. None of the sequences studied in this study coincided exactly with those deposited in GenBank.}, }
@article {pmid12675680, year = {2003}, author = {Punj, V and Chakrabarty, AM}, title = {Redox proteins in mammalian cell death: an evolutionarily conserved function in mitochondria and prokaryotes.}, journal = {Cellular microbiology}, volume = {5}, number = {4}, pages = {225-231}, doi = {10.1046/j.1462-5822.2003.00269.x}, pmid = {12675680}, issn = {1462-5814}, support = {ES-04050-17/ES/NIEHS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Azurin/genetics/metabolism ; Bacterial Proteins/genetics/*metabolism ; Biological Evolution ; Cell Death/*physiology ; Cytochrome c Group/metabolism ; Humans ; Mitochondria/enzymology/*metabolism ; Molecular Sequence Data ; Oxidation-Reduction ; Prokaryotic Cells/*metabolism ; Sequence Alignment ; Tumor Cells, Cultured ; }, abstract = {Mammalian cell mitochondria are believed to have prokaryotic ancestry. Mitochondria are not only the powerhouse of energy generation within the eukaryotic cell but they also play a major role in inducing apoptotic cell death through release of redox proteins such as cytochrome c and the apoptosis-inducing factor (AIF), a flavoprotein with NADH oxidase activity. Recent evidence indicates that some present day prokaryotes release redox proteins that induce apoptosis in mammalian cells through stabilization of the tumour suppressor protein p53. p53 interacts with mitochondria either directly or through activation of the genes for pro-apoptotic proteins such as Bax or NOXA or genes that encode redox enzymes responsible for the production of reactive oxygen species (ROS). The analogy between the ancient ancestors of present day bacteria, the mitochondria, and the present day bacteria with regard to their ability to release redox proteins for triggering mammalian cell death is an interesting example of functional conservation during the hundreds of millions of years of evolution. It is possible that the ancestors of the present day prokaryotes released redox proteins to kill the ancestors of the eukaryotes. During evolution of the mitochondria from prokaryotes as obligate endosymbionts, the mitochondria maintained the same functions to programme their own host cell death.}, }
@article {pmid12675371, year = {2003}, author = {Vala, F and Van Opijnen, T and Breeuwer, JA and Sabelis, MW}, title = {Genetic conflicts over sex ratio: mite-endosymbiont interactions.}, journal = {The American naturalist}, volume = {161}, number = {2}, pages = {254-266}, doi = {10.1086/345856}, pmid = {12675371}, issn = {0003-0147}, mesh = {Animals ; Biological Evolution ; Female ; Host-Parasite Interactions ; Litter Size ; Male ; *Reproduction ; *Sex Ratio ; *Symbiosis ; Tetranychidae/genetics/*microbiology/*physiology ; Wolbachia/*physiology ; }, abstract = {Nucleocytoplasmic genetic conflicts arise as a result of asymmetric transmission of cytoplasmic and nuclear genes. Spread of a cytoplasmic element promoting female-biased sex ratios creates selection on nuclear genes for mechanisms that decrease the bias. Here we investigate the conflict over sex ratio between the cytoplasmic bacterium Wolbachia and the two-spotted spider mite Tetranychus urticae Koch. We show that, first, infected females produce significantly more female-biased sex ratios than uninfected (cured) females. Second, this effect is not due to parthenogenesis, male killing, or feminization, phenotypes commonly associated with infection by Wolbachia. Third, sex ratio is a trait with a heritable component in this species; thus, it can evolve under selection. Fourth, the sex ratio produced by uninfected (cured) females changes over time, approaching the sex ratio produced by females from the infected culture. On the basis of these results, we suggest that after sex ratio manipulation by Wolbachia, a host compensatory mechanism evolved that allows infected females to produce the sex ratio favored by nuclear genes. We discuss the evolution of "mutualism" with respect to the evolution of host mechanisms that compensate for effects induced by vertically transmitted "parasites."}, }
@article {pmid12674481, year = {2003}, author = {Jeon, TJ and Jeon, KW}, title = {Characterization of sams genes of Amoeba proteus and the endosymbiotic X-bacteria.}, journal = {The Journal of eukaryotic microbiology}, volume = {50}, number = {1}, pages = {61-69}, doi = {10.1111/j.1550-7408.2003.tb00107.x}, pmid = {12674481}, issn = {1066-5234}, mesh = {Amino Acid Sequence ; Amoeba/classification/*enzymology/*microbiology ; Animals ; Bacteria/classification/genetics ; Base Sequence ; Cloning, Molecular ; Codon, Initiator/analysis ; Codon, Terminator/analysis ; *Genes, Bacterial ; Legionellaceae/*enzymology ; Methionine Adenosyltransferase/analysis/*genetics/metabolism ; Molecular Sequence Data ; Sequence Alignment ; Symbiosis ; }, abstract = {As a result of harboring obligatory bacterial endosymbionts, the xD strain of Amoeba proteus no longer produces its own S-adenosylmethionine synthetase (SAMS). When symbiont-free D amoebae are infected with symbionts (X-bacteria), the amount of amoeba SAMS decreases to a negligible level within four weeks, but about 47% of the SAMS activity, which apparently comes from another source, is still detected. Complete nucleotide sequences of sams genes of D and xD amoebae are presented and show that there are no differences between the two. Long-established xD amoebae contain an intact sams gene and thus the loss of xD amoeba's SAMS is not due to the loss of the gene itself. The open reading frame of the amoeba's sams gene has 1,281 nucleotides, encoding SAMS of 426 amino acids with a mass of 48 kDa and pI of 6.5. The amino acid sequence of amoeba SAMS is longer than the SAMS of other organisms by having an extra internal stretch of 28 amino acids. The 5'-flanking region of amoeba sams contains consensus-binding sites for several transcription factors that are related to the regulation of sams genes in E. coli and yeast. The complete nucleotide sequence of the symbiont's sams gene is also presented. The open reading frame of X-bacteria sams is 1,146 nucleotides long, encoding SAMS of 381 amino acids with a mass of 41 kDa and pI of 6.0. The X-bacteria SAMS has 45% sequence identity with that of A. proteus.}, }
@article {pmid12656162, year = {2003}, author = {Bianciotto, V and Lumini, E and Bonfante, P and Vandamme, P}, title = {'Candidatus glomeribacter gigasporarum' gen. nov., sp. nov., an endosymbiont of arbuscular mycorrhizal fungi.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {53}, number = {Pt 1}, pages = {121-124}, doi = {10.1099/ijs.0.02382-0}, pmid = {12656162}, issn = {1466-5026}, mesh = {Bacteria/*classification/*genetics/isolation &amp; purification/ultrastructure ; Base Sequence ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Fungi/*ultrastructure ; Genome, Bacterial ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Plants/microbiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Arbuscular mycorrhizal fungi are obligate endosymbionts that colonize the roots of almost 80 % of land plants. The present paper describes morphological and molecular data on a bacterial endosymbiont living in the cytoplasm of dormant or germinating spores and symbiotic mycelia of the fungal species Gigaspora margarita, Scutellospora persica and Scutellospora castanea. PCR amplification of almost the entire 16S rRNA gene of the Gigaspora margarita BEG 34 endosymbiont, using universal bacterial primers, and subsequent sequence analysis demonstrated that this organism occupies a very distinct phylogenetic position within the beta-Proteobacteria, with the genera Burkholderia, Pandoraea and Ralstonia as its closest neighbours. Primers specific to the 16S rDNA of the endosymbiotic bacteria of BEG 34 allowed amplification of spore DNA from endosymbionts of Gigaspora margarita, Gigaspora decipiens, S. persica and S. castanea, but not from the Gigaspora gigantea endosymbiont (which was morphologically different) or from the cytoplasm of Gigaspora rosea (which did not contain endosymbiotic bacteria). These specific primers were successfully used as a probe for the in-situ hybridization of endobacteria in Gigaspora margarita spores. The overall rod-shaped morphology of the Gigaspora margarita, Gigaspora decipiens, S. persica and S. castanea endosymbionts was similar, and amplification and sequence analysis of the almost-complete 16S rRNA genes of several Gigaspora margarita, S. persica and S. castanea endosymbionts revealed over 98% sequence similarity. These morphological and genomic characteristics were used to assign the endosymbionts of these three species (five isolates) of arbuscular mycorrhizal fungi as 'Candidatus Glomeribacter gigasporarum' gen. nov., sp. nov.}, }
@article {pmid12652910, year = {2002}, author = {Kang, L and Zhu, H and Cheng, Q and Zhou, W and Sun, L and Cai, L and Ma, X and Chen, C and Zhao, S and Li, C}, title = {Cloning and characterization of a gene encoding glutathione-regulated potassium-efflux system protein KefKL from the endosymbiont Wolbachia.}, journal = {DNA sequence : the journal of DNA sequencing and mapping}, volume = {13}, number = {6}, pages = {375-381}, doi = {10.1080/1042517021000003897}, pmid = {12652910}, issn = {1042-5179}, mesh = {Amino Acid Sequence ; Base Sequence ; Glutathione/*metabolism ; Molecular Sequence Data ; Potassium-Hydrogen Antiporters/*genetics/metabolism ; Sequence Analysis, DNA ; Wolbachia/*genetics/metabolism ; }, abstract = {The maternally inherited intracellular symbiont Wolbachia is well known for inducing a variety of reproductive and developmental abnormalities in the diverse arthropod hosts it infects. It has been implicated in causing cytoplasmic incompatibility (CI), parthenogenesis, feminization of genetic males and male killing in different hosts. However, the molecular mechanisms by which this fastidious bacterium causes these abnormalities have not yet been determined. In our study, representational difference analysis (RDA) was used to analyze the genomic difference between different Wolbachia strains. A gene encoding glutathione-regulated potassium-efflux system protein KefKL from Wolbachia in Drosophila simulans Riverside (w Ri) was isolated. The homologous genes from Wolbachia in Drosophila melanogaster yw67c23 (wMel) and Wolbachia in Drosophila melanogaster CantonS (wMelCS) were also cloned and sequenced. Sequence analysis showed that these deduced amino acid sequences contained two important motifs: Na+/H+ antiportor and NAD binding domain, which shared conserved sequences among different strains. Considering the crucial function of KefKL for ionic homeostasis, this gene might play an important role in Wolbachia physiology. Further study indicated that there was no homologue detected from Wolbachia in Drosophila simulans DSW/Mau (wMa) and Wolbachia in Drosophila simulans Noumea (wNo). Whether Wolbachia contained KefKL (or the homologous gene) was consistent with the phylogenetic studies using wsp sequences, which showed that wMa and wNo were grouped into one branch, while w Ri, wMel and wMelCS were more closely related.}, }
@article {pmid12632152, year = {2003}, author = {Kramer, LH and Passeri, B and Corona, S and Simoncini, L and Casiraghi, M}, title = {Immunohistochemical/immunogold detection and distribution of the endosymbiont Wolbachia of Dirofilaria immitis and Brugia pahangi using a polyclonal antiserum raised against WSP (Wolbachia surface protein).}, journal = {Parasitology research}, volume = {89}, number = {5}, pages = {381-386}, doi = {10.1007/s00436-002-0765-6}, pmid = {12632152}, issn = {0932-0113}, mesh = {Animals ; Antibodies, Bacterial/*immunology ; Antigens, Bacterial/analysis ; Bacterial Outer Membrane Proteins/*analysis/immunology ; Brugia pahangi/*microbiology ; Dirofilaria immitis/*microbiology ; Dirofilariasis/parasitology ; Dogs ; Doxycycline/pharmacology ; Female ; Gerbillinae/parasitology ; Immunohistochemistry ; Male ; Microscopy, Immunoelectron ; Symbiosis ; Wolbachia/drug effects/immunology/*isolation &amp; purification ; }, abstract = {Intracellular bacteria in filarial nematodes were described as early as the 1970s, yet it was only with the work on Dirofilaria immitis, the agent of canine and feline heartworm disease, that these microorganisms were identified as belonging to Wolbachia, a genus known for encompassing bacteria infecting insects and other arthropods. The implications for the presence of intracellular bacteria in filarial nematodes is now the subject of intense research, particularly regarding their role in the immunology and pathogenesis of disease in infected humans and animals and as a possible target for therapy. Here, the authors report results on the immunohistochemical and immunogold staining of Wolbachia in D. immitis and Brugia pahangi using polyclonal antibodies raised against the recombinant Wolbachia surface protein (WSP). The bacteria were present in the lateral hypodermal chords of both male and female worms and in the reproductive tract of adult females (oocytes, morulae, microfilariae). In D. immitis and B. pahangi from animals treated with tetracycline, positive staining was observed in the lateral chords of adult males and females, but was absent from the oocytes and morulae. These results indicate that Wolbachia endosymbionts can be identified immunohistochemically with anti-WSP polyclonal antibodies, that their distribution matches that already described for Wolbachia of other filarial worms, and that antibiotic treatment may impede the vertical transmission of these bacteria. Unequivocal detection of Wolbachia is essential for the study of this symbiont, in particular to monitor the effects of antibiotic treatment on worms. The use of a specific marker for bacteria in their nematode hosts represents an extremely useful tool in evaluating the pathogenic role and the effect of antibiotic treatment on these potential targets in the control of filarial disease.}, }
@article {pmid12597646, year = {2003}, author = {Ruang-Areerate, T and Kittayapong, P and Baimai, V and O'Neill, SL}, title = {Molecular phylogeny of Wolbachia endosymbionts in Southeast Asian mosquitoes (Diptera: Culicidae) based on wsp gene sequences.}, journal = {Journal of medical entomology}, volume = {40}, number = {1}, pages = {1-5}, doi = {10.1603/0022-2585-40.1.1}, pmid = {12597646}, issn = {0022-2585}, mesh = {Aedes/classification/genetics/microbiology ; Animals ; Asia, Southeastern ; Bacterial Outer Membrane Proteins/*genetics ; Base Sequence ; Culicidae/classification/genetics/*microbiology ; DNA Primers ; DNA, Bacterial/*genetics ; Genes, Bacterial ; Phylogeny ; Symbiosis ; Wolbachia/*classification/genetics/physiology ; }, abstract = {Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and nematodes and are associated with various reproductive abnormalities in their hosts. Insect-associated Wolbachia form a monophyletic clade in the alpha-Proteobacteria and recently have been separated into two supergroups (A and B) and 19 groups. Our recent polymerase chain reaction (PCR) survey using wsp specific primers indicated that various strains of Wolbachia were present in mosquitoes collected from Southeast Asia. Here, we report the phylogenetic relationship of the Wolbachia strains found in these mosquitoes using wsp gene sequences. Our phylogenetic analysis revealed eight new Wolbachia strains, five in the A supergroup and three in the B supergroup. Most of the Wolbachia strains present in Southeast Asian mosquitoes belong to the established Mors, Con, and Pip groups.}, }
@article {pmid12594927, year = {2003}, author = {Embley, TM and van der Giezen, M and Horner, DS and Dyal, PL and Foster, P}, title = {Mitochondria and hydrogenosomes are two forms of the same fundamental organelle.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {358}, number = {1429}, pages = {191-201; discussion 201-2}, pmid = {12594927}, issn = {0962-8436}, mesh = {Anaerobiosis ; *Biological Evolution ; Eukaryotic Cells/*cytology/enzymology/metabolism ; Hydrogen/*metabolism ; Hydrogenase/genetics/metabolism ; Mitochondria/*metabolism ; Organelles/*metabolism ; Phylogeny ; }, abstract = {Published data suggest that hydrogenosomes, organelles found in diverse anaerobic eukaryotes that make energy and hydrogen, were once mitochondria. As hydrogenosomes generally lack a genome, the conversion is probably one way. The sources of the key hydrogenosomal enzymes, pyruvate : ferredoxin oxidoreductase (PFO) and hydrogenase, are not resolved by current phylogenetic analyses, but it is likely that both were present at an early stage of eukaryotic evolution. Once thought to be restricted to a few unusual anaerobic eukaryotes, the proteins are intimately integrated into the fabric of diverse eukaryotic cells, where they are targeted to different cell compartments, and not just hydrogenosomes. There is no evidence supporting the view that PFO and hydrogenase originated from the mitochondrial endosymbiont, as posited by the hydrogen hypothesis for eukaryogenesis. Other organelles derived from mitochondria have now been described in anaerobic and parasitic microbial eukaryotes, including species that were once thought to have diverged before the mitochondrial symbiosis. It thus seems possible that all eukaryotes may eventually be shown to contain an organelle of mitochondrial ancestry, to which different types of biochemistry can be targeted. It remains to be seen if, despite their obvious differences, this family of organelles shares a common function of importance for the eukaryotic cell, other than energy production, that might provide the underlying selection pressure for organelle retention.}, }
@article {pmid12594925, year = {2003}, author = {Andersson, SG and Karlberg, O and Canbäck, B and Kurland, CG}, title = {On the origin of mitochondria: a genomics perspective.}, journal = {Philosophical transactions of the Royal Society of London. Series B, Biological sciences}, volume = {358}, number = {1429}, pages = {165-77; discussion 177-9}, pmid = {12594925}, issn = {0962-8436}, mesh = {Adenosine Triphosphate/metabolism ; Cell Nucleus/genetics ; DNA, Mitochondrial/*genetics ; Eukaryotic Cells/cytology ; *Evolution, Molecular ; *Genomics ; Mitochondria/*genetics/metabolism ; Phylogeny ; Protein Transport ; }, abstract = {The availability of complete genome sequence data from both bacteria and eukaryotes provides information about the contribution of bacterial genes to the origin and evolution of mitochondria. Phylogenetic analyses based on genes located in the mitochondrial genome indicate that these genes originated from within the alpha-proteobacteria. A number of ancestral bacterial genes have also been transferred from the mitochondrial to the nuclear genome, as evidenced by the presence of orthologous genes in the mitochondrial genome in some species and in the nuclear genome of other species. However, a multitude of mitochondrial proteins encoded in the nucleus display no homology to bacterial proteins, indicating that these originated within the eukaryotic cell subsequent to the acquisition of the endosymbiont. An analysis of the expression patterns of yeast nuclear genes coding for mitochondrial proteins has shown that genes predicted to be of eukaryotic origin are mainly translated on polysomes that are free in the cytosol whereas those of putative bacterial origin are translated on polysomes attached to the mitochondrion. The strong relationship with alpha-proteobacterial genes observed for some mitochondrial genes, combined with the lack of such a relationship for others, indicates that the modern mitochondrial proteome is the product of both reductive and expansive processes.}, }
@article {pmid12581590, year = {2003}, author = {Marcos-Atxutegi, C and Kramer, LH and Fernandez, I and Simoncini, L and Genchi, M and Prieto, G and Simón, F}, title = {Th1 response in BALB/c mice immunized with Dirofilaria immitis soluble antigens: a possible role for Wolbachia?.}, journal = {Veterinary parasitology}, volume = {112}, number = {1-2}, pages = {117-130}, doi = {10.1016/s0304-4017(02)00419-3}, pmid = {12581590}, issn = {0304-4017}, mesh = {Animals ; Antibodies, Bacterial/immunology ; Antibodies, Helminth/immunology ; Antigens, Helminth/chemistry/*immunology ; Cytokines/blood ; Dirofilaria immitis/chemistry/*immunology/*microbiology ; Eosinophils/immunology ; Female ; Immunoglobulin E/blood ; Immunoglobulin G/blood ; Leukocyte Count ; Mice ; Mice, Inbred BALB C ; Neutrophils/immunology ; Solubility ; Th1 Cells/*immunology ; Th2 Cells/immunology ; Time Factors ; Wolbachia/*immunology/*physiology ; }, abstract = {The immune response to filarial infection has been shown to be of both the Th1 and Th2 types. Studies aimed at developing immunization strategies against Dirofilaria immitis infection in dogs have shown that protection against larval challenge is of the Th2 type and that several proteins are recognized by immunized or infected animals. The bacterial endosymbiont Wolbachia, harbored by many filarial species including D. immitis, has recently been shown to interact with the host immune system. Specific antibodies to the Wolbachia recombinant surface protein (WSPr) have been observed in cats infected with D. immitis. In this work the authors have determined cytokine production and antibody response in BALB/c mice inoculated with soluble antigens from third stage larvae or from adult worms of D. immitis. Inoculated mice first produced IFN-gamma followed by a peak in IL-4. Specific antibodies to the Wolbachia protein WSPr were exclusively IgG2a, while antibodies against peptides derived from antigens of D. immitis were in the IgG1 and IgE subclasses. The cytokine response is thus similar to that reported for other filarial infection, where Th1 response shifts towards Th2. Antibody response indicates that Wolbachia may induce preferentially a Th1 response during filarial infection, while nematode antigens may be involved in Th2 response. There is thus an overall agreement with current opinions on the role of bacterial versus nematode molecules in driving the response towards the different directions.}, }
@article {pmid12574860, year = {2003}, author = {Amiri, H and Karlberg, O and Andersson, SG}, title = {Deep origin of plastid/parasite ATP/ADP translocases.}, journal = {Journal of molecular evolution}, volume = {56}, number = {2}, pages = {137-150}, doi = {10.1007/s00239-002-2387-0}, pmid = {12574860}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Bacterial Proteins/genetics ; Chlamydiaceae/enzymology/genetics ; Eukaryotic Cells/enzymology/microbiology ; Evolution, Molecular ; Gene Transfer, Horizontal ; Host-Parasite Interactions ; Mitochondria/enzymology/genetics ; Mitochondrial ADP, ATP Translocases/*genetics ; Molecular Sequence Data ; *Phylogeny ; Plastids/*enzymology/genetics ; Rickettsia/*enzymology/genetics ; Rickettsia rickettsii/enzymology/genetics ; Rickettsia typhi ; Sequence Analysis ; Sequence Homology, Amino Acid ; }, abstract = {Membrane proteins that transport ATP and ADP have been identified in mitochondria, plastids, and obligate intracellular parasites. The mitochondrial ATP/ADP transporters are derived from a broad-specificity transport family of eukaryotic origin, whereas the origin of the plastid/parasite ATP/ADP translocase is more elusive. Here we present the sequences of five genes coding for ATP/ADP translocases from four species of Rickettsia. The results are consistent with an early duplication and divergence of the five ATP/ADP translocases within the rickettsial lineage. A comparison of the phylogenetic depths of the mitochondrial and the plastid/parasite ATP/ADP translocases indicates a deep origin for both transporters. The results provide no evidence for a recent acquisition of the ATP/ADP transporters in Rickettsia via horizontal gene transfer, as previously suggested. A possible function of the two types of ATP/ADP translocases was to allow switches between glycolysis and aerobic respiration in the early eukaryotic cell and its endosymbiont.}, }
@article {pmid12573064, year = {2002}, author = {Groenenboom, MA and Hogeweg, P}, title = {Space and the persistence of male-killing endosymbionts in insect populations.}, journal = {Proceedings. Biological sciences}, volume = {269}, number = {1509}, pages = {2509-2518}, pmid = {12573064}, issn = {0962-8452}, mesh = {Animals ; Female ; Insecta/growth &amp; development/*microbiology ; Male ; Models, Biological ; Polymorphism, Genetic ; Sex Ratio ; *Symbiosis ; Wolbachia/genetics/*growth &amp; development/*pathogenicity ; }, abstract = {Male-killing bacteria are bacteria that are transmitted vertically through the females of their insect hosts. They can distort the sex ratio of their hosts by killing infected male offspring. In nature, male-killing endosymbionts (male killers) often have a 100% efficient vertical transmission, and multiple male-killing bacteria infecting a single population are observed. We use different model formalisms to study these observations. In mean-field models a male killer with perfect transmission drives the host population to extinction, and coexistence between multiple male killers within one population is impossible; however, in spatially explicit models, both phenomena are readily observed. We show how the spatial pattern formation underlies these results. In the case of high transmission efficiencies, waves with a high density of male killers alternate with waves of mainly wild-type hosts. The male killers cause local extinction, but this creates an opportunity for uninfected hosts to re-invade these areas. Spatial pattern formation also creates an opportunity for two male killers to coexist within one population: different strains create spatial regions that are qualitatively different; these areas then serve as different niches, making coexistence possible.}, }
@article {pmid12572614, year = {1998}, author = {Spaulding, AW and von Dohlen, CD}, title = {Phylogenetic characterization and molecular evolution of bacterial endosymbionts in psyllids (Hemiptera: Sternorrhyncha).}, journal = {Molecular biology and evolution}, volume = {15}, number = {11}, pages = {1506-1513}, doi = {10.1093/oxfordjournals.molbev.a025878}, pmid = {12572614}, issn = {0737-4038}, mesh = {Animals ; Bacteria/*genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Eubacterium/genetics ; *Evolution, Molecular ; Gammaproteobacteria/genetics ; Hemiptera/*classification/genetics/*microbiology ; Mutagenesis/genetics ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis/*genetics ; }, abstract = {Most sternorrhynchan insects harbor endosymbiotic bacteria in specialized cells (bacteriocytes) near the gut which provide essential nutrients for hosts. In lineages investigated so far with molecular methods (aphids, mealybugs, whiteflies), endosymbionts apparently have arisen from independent infections of common host ancestors and co-speciated with their hosts. Some endosymbionts also exhibit putatively negative genetic effects from their symbiotic association. In this study, the identity of endosymbionts in one major sternorrhynchan lineage, psyllids (Psylloidea), was investigated to determine their position in eubacterial phylogeny and their relationship to other sternorrhynchan endosymbionts. Small-subunit ribosomal RNA genes (16S rDNA) from bacteria in three psyllid species (families Psyllidae and Triozidae) were sequenced and incorporated into an alignment including other insect endosymbionts and free-living bacteria. In phylogenetic analysis, all sequences were placed within the gamma subdivision of the Proteobacteria. Three sequences, one from each psyllid species, formed a highly supported monophyletic group whose branching order matched the host phylogeny, and also exhibited accelerated rates of evolution and mutational bias toward A and T nucleotides. These attributes, characteristic of primary (P) bacteriocyte-dwelling endosymbionts, suggested that these sequences were from the putative psyllid P endosymbiont. Two other sequences were placed within the gamma-3 subgroup of Proteobacteria and were hypothesized to be secondary endosymbionts. The analysis also suggested a sister relationship between P endosymbionts of psyllids and whiteflies. Thus, a continuous mutualistic association between bacteria and insects may have existed since the common ancestor of psyllids and whiteflies. Calculations using a universal substitution rate in bacteria corrected for endosymbiont rate acceleration support the idea that this common ancestor was also the ancestor of all Sternorrhyncha. Compared with other P endosymbiont lineages, the genetic consequences of intracellular life for some psyllid endosymbionts have been exaggerated, indicating possible differences in population structures of bacteria and/or hosts.}, }
@article {pmid12537121, year = {2002}, author = {Chirgwin, SR and Porthouse, KH and Nowling, JM and Klei, TR}, title = {The filarial endosymbiont Wolbachia sp. is absent from Setaria equina.}, journal = {The Journal of parasitology}, volume = {88}, number = {6}, pages = {1248-1250}, doi = {10.1645/0022-3395(2002)088[1248:TFEWSI]2.0.CO;2}, pmid = {12537121}, issn = {0022-3395}, support = {AI-19199-16/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Female ; Horse Diseases/parasitology ; Horses ; Male ; Peritoneal Cavity/parasitology ; Polymerase Chain Reaction/veterinary ; RNA, Ribosomal, 16S/genetics ; Setaria Nematode/microbiology/*physiology ; Setariasis/parasitology ; *Symbiosis ; Wolbachia/genetics/isolation &amp; purification/*physiology ; }, abstract = {Wolbachia sp. was first reported in filarial nematodes over 25 yr ago. Today, much research is focused on the role of these bacteria in filarial worm biology. The filarial symbionts are closely related to arthropod symbionts, which are known to modify host reproduction and biology through various mechanisms. Similarly, it has been suggested that Wolbachia sp. is essential for long-term survival and reproduction of filariae. We report that Wolbachia sp. 16S rDNA was not found in the equine filarial nematode Setaria equina, using either polymerase chain reaction (PCR) or DNA hybridization. In addition, ultrastructural analysis of adult worms did not reveal the presence of Wolbachia sp. in hypodermal cords or reproductive tissues. These data suggest that like Onchocerca flexuosa and Acanthocheilonema vitae, S. equina may not be dependent on Wolbachia sp. for survival.}, }
@article {pmid12531908, year = {2003}, author = {Que-Gewirth, NL and Karbarz, MJ and Kalb, SR and Cotter, RJ and Raetz, CR}, title = {Origin of the 2-amino-2-deoxy-gluconate unit in Rhizobium leguminosarum lipid A. Expression cloning of the outer membrane oxidase LpxQ.}, journal = {The Journal of biological chemistry}, volume = {278}, number = {14}, pages = {12120-12129}, pmid = {12531908}, issn = {0021-9258}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; R37-GM51796/GM/NIGMS NIH HHS/United States ; GM-08558/GM/NIGMS NIH HHS/United States ; R37 GM051796-06/GM/NIGMS NIH HHS/United States ; GM54882/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Anaerobiosis ; Bacterial Outer Membrane Proteins/*genetics/metabolism ; Cloning, Molecular ; Deoxyribonuclease HindIII ; Escherichia coli ; Gene Expression Regulation, Bacterial ; Gene Expression Regulation, Enzymologic ; Glucosamine/*analogs &amp; derivatives/chemistry/*metabolism ; In Vitro Techniques ; Lipid A/*metabolism ; Mass Spectrometry ; Molecular Sequence Data ; Oxidoreductases/*genetics/metabolism ; Phosphotransferases (Alcohol Group Acceptor)/*genetics/metabolism ; Recombinant Proteins/genetics/metabolism ; Rhizobium leguminosarum/enzymology/*genetics ; }, abstract = {An unusual feature of the lipid A from the plant endosymbionts Rhizobium etli and Rhizobium leguminosarum is the presence of a proximal sugar unit consisting of a 2-amino-2-deoxy-gluconate moiety in place of glucosamine. An outer membrane oxidase that generates the 2-amino-2-deoxy-gluconate unit from a glucosamine-containing precursor is present in membranes of R. leguminosarum and R. etli but not in S. meliloti or Escherichia coli. We now report the identification of a hybrid cosmid that directs the overexpression of this activity by screening 1800 lysates of individual colonies of a R. leguminosarum 3841 genomic DNA library in the host strain R. etli CE3. Two cosmids (p1S11D and p1U12G) were identified in this manner and transferred into S. meliloti, in which they also directed the expression of oxidase activity in the absence of any chromosomal background. Subcloning and sequencing of the oxidase gene on a 6.5-kb fragment derived from the approximately 20-kb insert in p1S11D revealed that the enzyme is encoded by a gene (lpxQ) that specifies a protein of 224 amino acid residues with a putative signal sequence cleavage site at position 28. Heterologous expression of lpxQ using the T7lac promoter system in E. coli resulted in the production of catalytically active oxidase that was localized in the outer membrane. A new outer membrane protein of the size expected for LpxQ was present in this construct and was subjected to microsequencing to confirm its identity and the site of signal peptide cleavage. LpxQ expressed in E. coli generates the same products as seen in R. leguminosarum membranes. LpxQ is dependent on O(2) for activity, as demonstrated by inhibition of the reaction under strictly anaerobic conditions. An ortholog of LpxQ is present in the genome of Agrobacterium tumefaciens, as shown by heterologous expression of oxidase activity in E. coli.}, }
@article {pmid12530210, year = {2002}, author = {Haines, LR and Haddow, JD and Aksoy, S and Gooding, RH and Pearson, TW}, title = {The major protein in the midgut of teneral Glossina morsitans morsitans is a molecular chaperone from the endosymbiotic bacterium Wigglesworthia glossinidia.}, journal = {Insect biochemistry and molecular biology}, volume = {32}, number = {11}, pages = {1429-1438}, doi = {10.1016/s0965-1748(02)00063-2}, pmid = {12530210}, issn = {0965-1748}, support = {AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Cloning, Molecular ; Digestive System/*chemistry ; Enterobacteriaceae/*physiology ; Insect Proteins/*chemistry/genetics/isolation &amp; purification ; Life Cycle Stages ; Mass Spectrometry ; Molecular Chaperones/*chemistry/genetics/isolation &amp; purification ; Molecular Sequence Data ; Peptide Fragments/chemistry/isolation &amp; purification ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis ; Tsetse Flies/growth &amp; development/microbiology/*physiology ; }, abstract = {Molecules in the midgut of the tsetse fly (Diptera: Glossinidiae) are thought to play an important role in the life cycle of African trypanosomes by influencing their initial establishment in the midgut and subsequent differentiation events that ultimately affect parasite transmission. It is thus important to determine the molecular composition of the tsetse midgut to aid in understanding disease transmission by these medically important insect vectors. Here, we report that the most abundant protein in the midguts of teneral (unfed) Glossina morsitans morsitans is a 60 kDa molecular chaperone of bacterial origin. Two species of symbiotic bacteria reside in the tsetse midgut, Sodalis glossinidius and Wigglesworthia glossinidia. To determine the exact origin of the 60 kDa molecule, a protein microchemical approach involving two-dimensional (2-D) gel electrophoresis and mass spectrometry was used. Peptide mass maps were compared to virtual peptide maps predicted for S. glossinidius and W. glossinidia 60 kDa chaperone sequences. Four signature peptides were identified, revealing that the source of the chaperone was W. glossinidia. Comparative 2-D gel electrophoresis and immunoblotting further revealed that this protein was localized to the bacteriome and not the distal portion of the tsetse midgut. The possible function of this highly abundant endosymbiont chaperone in the tsetse midgut is discussed.}, }
@article {pmid12522059, year = {2003}, author = {Simón, F and Prieto, G and Morchón, R and Bazzocchi, C and Bandi, C and Genchi, C}, title = {Immunoglobulin G antibodies against the endosymbionts of filarial nematodes (Wolbachia) in patients with pulmonary dirofilariasis.}, journal = {Clinical and diagnostic laboratory immunology}, volume = {10}, number = {1}, pages = {180-181}, pmid = {12522059}, issn = {1071-412X}, mesh = {Animals ; Antibodies, Bacterial/*blood ; Antibody Formation ; Dirofilaria ; Dirofilariasis/*diagnosis/epidemiology ; Disease Vectors ; Enzyme-Linked Immunosorbent Assay ; Humans ; Immunoglobulin G/blood ; Solitary Pulmonary Nodule/parasitology ; Symbiosis ; Wolbachia/immunology ; }, abstract = {The dog parasite Dirofilaria immitis can infect humans. Patients with pulmonary dirofilariasis were tested for immunoglobulin G (IgG) antibodies against the surface protein of Wolbachia, the bacterial endosymbiont of D. immitis. These patients showed significantly higher IgG titers than healthy individuals from areas in which D. immitis was endemic as well as areas in which it was not endemic. Titration of anti-Wolbachia surface protein IgG could become useful for diagnostic applications.}, }
@article {pmid12519917, year = {2003}, author = {Marx, S and Baumgärtner, M and Kannan, S and Braun, HP and Lang, BF and Burger, G}, title = {Structure of the bc1 complex from Seculamonas ecuadoriensis, a jakobid flagellate with an ancestral mitochondrial genome.}, journal = {Molecular biology and evolution}, volume = {20}, number = {1}, pages = {145-153}, doi = {10.1093/molbev/msg016}, pmid = {12519917}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Animals ; Cells, Cultured ; Electron Transport Complex III/*chemistry/*genetics ; Eukaryota/*chemistry/genetics ; Evolution, Molecular ; Humans ; Mitochondria/*genetics/physiology ; Molecular Sequence Data ; *Protein Structure, Quaternary ; Protein Subunits/chemistry/genetics ; Sequence Alignment ; }, abstract = {In eubacteria, the respiratory bc(1) complex (complex III) consists of three or four different subunits, whereas that of mitochondria, which have descended from an alpha-proteobacterial endosymbiont, contains about seven additional subunits. To understand better how mitochondrial protein complexes evolved from their simpler bacterial predecessors, we purified complex III of Seculamonas ecuadoriensis, a member of the jakobid protists, which possess the most bacteria-like mitochondrial genomes known. The S. ecuadoriensis complex III has an apparent molecular mass of 460 kDa and exhibits antimycin-sensitive quinol:cytochrome c oxidoreductase activity. It is composed of at least eight subunits between 6 and 46 kDa in size, including two large "core" subunits and the three "respiratory" subunits. The molecular mass of the S. ecuadoriensis bc(1) complex is slightly lower than that reported for other eukaryotes, but about 2x as large as complex III in bacteria. This indicates that the departure from the small bacteria-like complex III took place at an early stage in mitochondrial evolution, prior to the divergence of jakobids. We posit that the recruitment of additional subunits in mitochondrial respiratory complexes is a consequence of the migration of originally alpha-proteobacterial genes to the nucleus.}, }
@article {pmid12508863, year = {2002}, author = {Van Oevelen, S and De Wachter, R and Vandamme, P and Robbrecht, E and Prinsen, E}, title = {Identification of the bacterial endosymbionts in leaf galls of Psychotria (Rubiaceae, angiosperms) and proposal of 'Candidatus Burkholderia kirkii' sp. nov.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {52}, number = {Pt 6}, pages = {2023-2027}, doi = {10.1099/00207713-52-6-2023}, pmid = {12508863}, issn = {1466-5026}, mesh = {Base Sequence ; Burkholderia/*classification/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Genes, Bacterial ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Psychotria/*microbiology ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; Terminology as Topic ; }, abstract = {This paper reports the identification of bacterial endosymbionts inhabiting the leaf galls of Psychotria kirkii. A phylogenetic approach was used to reveal the identity of these as yet uncultivable bacterial endophytes. Based on the analysis of 16S rDNA sequences, evolutionary trees were constructed that place the endosymbiont in the genus Burkholderia. Low levels of sequence identity and rather large evolutionary distances to the closest validly named relatives indicate that these symbiotic bacteria represent a novel species. Until cultivation is successful or until more phenotypic data become available the provisional name 'Candidatus Burkholderia kirkii' sp. nov. is proposed.}, }
@article {pmid12503847, year = {2003}, author = {Hashimoto, H}, title = {Plastid division: its origins and evolution.}, journal = {International review of cytology}, volume = {222}, number = {}, pages = {63-98}, doi = {10.1016/s0074-7696(02)22012-4}, pmid = {12503847}, issn = {0074-7696}, mesh = {Animals ; Arabidopsis Proteins ; Cell Division ; Cyanobacteria/genetics/physiology ; Eukaryota/genetics/metabolism ; *Evolution, Molecular ; Intracellular Membranes/physiology ; Plant Proteins ; Plastids/*genetics/metabolism ; Symbiosis ; }, abstract = {Photosynthetic eukaryotes have evolved plastid division mechanisms since acquisition of plastids through endosymbiosis. The emerging evolutionary origin of the plastid division mechanism is remarkably complex. The constituents of the division apparatus of plastids may have complex origins. The one constituent is the plastid FtsZ ring taken over from the cyanobacteria-like ancestral endosymbionts. The second is the doublet of concentric plastid dividing rings (or triplet in red algae), possibly acquired by ancestral host eukaryotes following the primary endosymbiotic event. Placement of the division apparatus at the correct division site may involve a system analogous to the bacterial Min system. Plastid nucleoid partitioning may be mediated by binding to envelope or thylakoid membranes. Multiple copies of plastid DNA and symmetrical distribution of the nucleoids in the plastids may permit faithful transmission to daughter plastids via equal binary plastid divisions. Cyanelles retain peptidoglycan wall and cyanelle division occurs through septum formation such as bacterial cell division. Cyanelle division involves the cyanelle ring analogous to the inner stromal plastid-dividing (PD) ring. According to the prevailing hypothesis that primary endosymbiosis occurred only once, cyanelle division may represent an intermediate stage between cyanobacterial division and the well-known plastid division among extant plants. With the secondary plastids, which are surrounded by three or four membranes, the PD ring also participates in division of the inner two "true" plastid envelope membranes, and the third and the outermost membranes divide by unknown mechanisms.}, }
@article {pmid12503681, year = {2002}, author = {Lynn, DH and Strüder-Kypke, M}, title = {Phylogenetic position of Licnophora, Lechriopyla, and Schizocaryum, three unusual ciliates (phylum Ciliophora) endosymbiotic in echinoderms (phylum Echinodermata).}, journal = {The Journal of eukaryotic microbiology}, volume = {49}, number = {6}, pages = {460-468}, doi = {10.1111/j.1550-7408.2002.tb00229.x}, pmid = {12503681}, issn = {1066-5234}, mesh = {Animals ; Ciliophora/classification/*genetics/growth &amp; development ; Echinodermata/*parasitology ; Molecular Sequence Data ; *Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Various echinoderms are colonized by species from several classes of the Phylum Ciliophora, indicating that the echinoderm "habitat" has been invaded independently on numerous occasions throughout evolutionary history. Two "echinoderm" ciliates whose phylogenetic positions have been problematic are Licnophora macfarlandi Stevens, 1901 and Schizocaryum dogieli Poljansky and Golikova, 1957. Licnophora macfarlandi is an endosymbiont of the respiratory trees of holothuroids, and S. dogieli is found in the esophagus of echinoids. A third species, Lechriopyla mystax Lynch, 1930, is a plagiopylid ciliate found in the intestine of echinoids. Host echinoderms were collected near the Friday Harbor Laboratories, San Juan Island, WA. Specimens of S. dogieli and L. mystax were obtained from the esophagus and intestine, respectively, of the sea urchin Strongylocentrotus pallidus. Specimens of L. macfarlandi were collected from the fluid obtained from the respiratory trees of Parastichopus californicus. Using small subunit ribosomal RNA (SSrRNA) sequences of these three ciliates and a global alignment of SSrRNA sequences of other ciliates, we established the following. 1) Licnophora is a spirotrich ciliate, clearly related to the hypotrichs and stichotrichs; this is corroborated by its possession of macronuclear replication bands. 2) Lechriopyla is the sister genus to Plagiopyla and is a member of the Class Plagiopylea, which was predicted based on its cytology. 3) Schizocaryum clusters in the Class Oligohymenophorea and is most closely related to the scuticociliates; there are currently no morphological features known to relate Schizocaryum to the scuticociliates.}, }
@article {pmid12503402, year = {2002}, author = {Sayed, WF and Wheeler, CT and el-Sharouny, HM and Mohawad, SM and Abdel-Karim, MM}, title = {Effects of storage time and temperature on the infectivity and effectiveness of Frankia entrapped in polyacrylamide gel.}, journal = {Folia microbiologica}, volume = {47}, number = {5}, pages = {545-550}, pmid = {12503402}, issn = {0015-5632}, mesh = {*Acrylic Resins ; Culture Media ; Frankia/growth &amp; development/*pathogenicity ; Microbiological Techniques ; Plant Roots/microbiology ; Plants/*microbiology ; *Symbiosis ; *Temperature ; }, abstract = {Four Frankia-Casuarina endosymbiont strains were tested for their infectivity and effectiveness on C. equisetifolia plants after 1 d, 3 and 6 months of Frankia storage at 7, 28 and 40 degrees C as liquid-cultures and polyacrylamide gel (PAG)-immobilized inocula. At lower temperature the number of nodules was the same or higher than control for liquid inocula except after 6 months of storage. For the PAG-entrapped Frankia lower numbers of nodules were recorded due to the use of high Frankia titers. In general, the results showed comparable plant dry mass, total nitrogen, root to shoot and nodules to plant ratios at lower temperature treatments. Increasing time and temperature was accompanied with reduced infectivity and effectiveness on inoculated plants. No nodulation was scored on plants inoculated with liquid and PAG-entrapped inocula stored at 40 degrees C for 6 months; subsequently, plant growth was inhibited. The variations in results obtained for different strains and treatments lead to variations in plant nitrogen-fixing ability. The use of PAG as a carrier for different Frankia strains is suggested; the recommended storage temperature for PAG-immobilized Frankia in 7-28 degrees C for up to 3 months.}, }
@article {pmid12480722, year = {2002}, author = {Shick, JM and Dunlap, WC and Pearse, JS and Pearse, VB}, title = {Mycosporine-like amino acid content in four species of sea anemones in the genus Anthopleura reflects phylogenetic but not environmental or symbiotic relationships.}, journal = {The Biological bulletin}, volume = {203}, number = {3}, pages = {315-330}, doi = {10.2307/1543574}, pmid = {12480722}, issn = {0006-3185}, mesh = {Amino Acids/*analysis ; Animals ; *Environment ; Eukaryota/chemistry/isolation &amp; purification/physiology ; Light ; *Phylogeny ; Sea Anemones/*chemistry/*classification/physiology ; Species Specificity ; *Symbiosis ; Ultraviolet Rays ; }, abstract = {We examine the occurrence of UV-absorbing, mycosporine-like amino acids (MAAs) in four sympatric species of sea anemones in the genus Anthopleura, all collected from intertidal habitats on the Pacific Coast of temperate North America. We compare patterns of MAAs in A. elegantissima of several types: specimens having predominately zooxanthellae (dinoflagellates comprising at least two species) or zoochlorellae as symbionts; those containing algal endosymbionts of both kinds, and naturally occurring aposymbiotic specimens that lack the endosymbionts typically found in most specimens. We also compare MAAs in zooxanthellate specimens of A. sola and A. xanthogrammica, and specimens from the asymbiotic species A. artemisia. Our findings indicate that the complements of the four major MAAs in these species of Anthopleura (mycosporine-taurine, shinorine, porphyra-334, and mycosporine-2 glycine) broadly reflect phylogenetic differences among the anemones rather than the taxon of endosymbionts, presence or absence of symbionts, or environmental factors. An exception, however, occurs in A. elegantissima, where mycosporine-2 glycine increases in concentration with the density of zooxanthellae. Our evidence also shows that A. elegantissima can accumulate MAAs from its food, which may explain the occasional occurrence of minor MAAs in some individuals.}, }
@article {pmid12475050, year = {2002}, author = {Zimmer, M}, title = {Nutrition in terrestrial isopods (Isopoda: Oniscidea): an evolutionary-ecological approach.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {77}, number = {4}, pages = {455-493}, doi = {10.1017/s1464793102005912}, pmid = {12475050}, issn = {1464-7931}, mesh = {Adaptation, Physiological ; *Animal Nutritional Physiological Phenomena ; Animals ; Biological Evolution ; Digestion ; Ecosystem ; Feces/microbiology ; Isopoda/anatomy &amp; histology/enzymology/*physiology ; Nutritional Requirements ; }, abstract = {The nutritional morphology, physiology and ecology of terrestrial isopods (Isopoda: Oniscidea) is significant in two respects. (1) Most oniscid isopods are truly terrestrial in terms of being totally independent of the aquatic environment. Thus, they have evolved adaptations to terrestrial food sources. (2) In many terrestrial ecosystems, isopods play an important role in decomposition processes through mechanical and chemical breakdown of plant litter and by enhancing microbial activity. While the latter aspect of nutrition is discussed only briefly in this review, I focus on the evolutionary ecology of feeding in terrestrial isopods. Due to their possessing chewing mouthparts, leaf litter is comminuted prior to being ingested, facilitating both enzymatic degradation during gut passage and microbial colonization of egested faeces. Digestion of food through endogenous enzymes produced in the caeca of the midgut glands (hepatopancreas) and through microbial enzymes, either ingested along with microbially colonized food or secreted by microbial endosymbionts, mainly takes place in the anterior part of the hindgut. Digestive processes include the activity of carbohydrases, proteases, dehydrogenases, esterases, lipases, arylamidases and oxidases, as well as the nutritional utilization of microbial cells. Absorption of nutrients is brought about by the hepatopancreas and/or the hindgut epithelium, the latter being also involved in osmoregulation and water balance. Minerals and metal cations are effectively extracted from the food, while overall assimilation efficiencies may be low. Heavy metals are stored in special organelles of the hepatopancreatic tissue. Nitrogenous waste products are excreted via ammonia in its gaseous form, with only little egested along with the faeces. Nonetheless, faeces are characterized by high nitrogen content and provide a favourable substrate for microbial colonization and growth. The presence of a dense microbial population on faecal material is one reason for the coprophagous behaviour of terrestrial isopods. For the same reason, terrestrial isopods prefer feeding on decaying rather than fresh leaf litter, the former also being more palatable and easier to digest. Acceptable food sources are detected through distance and contact chemoreceptors. The 'quality' of the food source determines individual growth, fecundity and mortality, and thus maintenance at the population level. Due to their physiological adaptations to feeding on and digesting leaf litter, terrestrial isopods contribute strongly to nutrient recycling during decomposition processes. Yet, many of these adaptations are still not well understood.}, }
@article {pmid12471902, year = {2000}, author = {Schnell, DJ}, title = {Functions and origins of the chloroplast protein-import machinery.}, journal = {Essays in biochemistry}, volume = {36}, number = {}, pages = {47-59}, doi = {10.1042/bse0360047}, pmid = {12471902}, issn = {0071-1365}, mesh = {Chloroplasts/*metabolism ; Intracellular Membranes/metabolism ; Plant Proteins/*metabolism ; Protein Precursors/*metabolism ; *Protein Transport ; }, abstract = {The vast majority of chloroplast proteins are nuclear-encoded and are imported into the organelle after synthesis in the cytoplasm. Targeting to chloroplasts is mediated by a variety of intrinsic targeting signals that direct the preprotein to its proper organelle subcompartment. Translocation at the envelope membrane is directed by the interactions of an N-terminal transit sequences on the preprotein and a general import machinery composed of the outer-membrane Toc machinery and the inner-membrane Tic machinery. The Toc and Tic components interact to bypass the intermembrane space and provide direct transport of preproteins from the cytoplasm to the stroma. There are at least four targeting pathways to the thylakoid membrane, the cpSec pathway, the delta pH pathway, the cpSRP pathway and the spontaneous pathway. These pathways require distinct intrinsic targeting signals, and apparently evolved to accommodate the translocation of classes of proteins with particular characteristics. Proteins similar to some components of the envelope and thylakoid translocation pathways are found in bacterial systems. However, a number of components do not have bacterial counterparts and are unique to the chloroplast pathways. It therefore appears that the chloroplast translocation systems have evolved from membrane-transport systems that were present in the original endosymbiont by incorporating proteins necessary to adapt to the constraints of endosymbiosis.}, }
@article {pmid12470940, year = {2003}, author = {Clark, JW and Kambhampati, S}, title = {Phylogenetic analysis of Blattabacterium, endosymbiotic bacteria from the wood roach, Cryptocercus (Blattodea: Cryptocercidae), including a description of three new species.}, journal = {Molecular phylogenetics and evolution}, volume = {26}, number = {1}, pages = {82-88}, doi = {10.1016/s1055-7903(02)00330-5}, pmid = {12470940}, issn = {1055-7903}, mesh = {Animals ; Bacteria/*genetics ; Cockroaches/*microbiology ; Evolution, Molecular ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; }, abstract = {Members of the cockroach genus Cryptocercus are wood-feeding, subsocial insects that live in temperate forests of the Nearctic and Palaearctic. At present, nine species are recognized: Cryptocercus relictus and Cryptocercus kyebangensis in eastern Asia and Russia, Cryptocercus primarius and Cryptocercus matilei in southwestern China, Cryptocercus clevelandi in the western USA, and Cryptocercus darwini, Cryptocercus garciai, Cryptocercus punctulatus, and Cryptocercus wrighti in the eastern USA. Like all extant cockroaches, Cryptocercus harbor endosymbiotic bacteria, Blattabacterium, in their fat bodies. The endosymbionts in all cockroaches have been considered a single species, Blattabacterium cuenoti, since their discovery about a century ago. However, a recent analysis of DNA sequences from representatives of four cockroach families has indicated that there is considerable DNA sequence divergence among B. cuenoti from different host species. As a part of our studies on the evolution of Cryptocercus, we examined DNA sequence divergence among B. cuenoti from six of the nine known Cryptocercus species. Specifically, we sequenced approximately 2,400 bp of the 16S rRNA and 23S rRNA genes of B. cuenoti from six species of Cryptocercus. We found that B. cuenoti in Cryptocercus has differentiated into multiple monophyletic lineages distinguishable by DNA sequence of rRNA genes and host association. Our sequence divergence estimates were consistent with those reported for other, congeneric bacterial species. We propose the recognition of three new species of Blattabacterium within Cryptocercus species as follows: Blattabacterium relictus sp. nov. in C. relictus, Blattabacterium clevelandi sp. nov. in C. clevelandi, and Blattabacterium punctulatus sp. nov. in C. darwini, C. garciai, C. punctulatus, and C. wrighti.}, }
@article {pmid12459260, year = {2002}, author = {Emelyanov, VV}, title = {Phylogenetic relationships of organellar Hsp90 homologs reveal fundamental differences to organellar Hsp70 and Hsp60 evolution.}, journal = {Gene}, volume = {299}, number = {1-2}, pages = {125-133}, doi = {10.1016/s0378-1119(02)01021-1}, pmid = {12459260}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Chaperonin 60/genetics ; Chloroplasts/genetics ; *Evolution, Molecular ; HSP70 Heat-Shock Proteins/genetics ; HSP90 Heat-Shock Proteins/genetics ; Heat-Shock Proteins/*genetics ; Humans ; Mitochondria/genetics ; Models, Genetic ; Molecular Sequence Data ; Organelles/*genetics ; *Phylogeny ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; }, abstract = {In agreement with endosymbiont theory for the origin of organelles, mitochondria and chloroplasts (plastids) are universally accepted to have monophyletically arisen from within alpha-proteobacteria and cyanobacteria, respectively. Convincing particular evidence in support of this theory emerged from phylogenetic analysis of highly conserved, ubiquitous heat shock proteins (Hsps) chaperonin 60 and Hsp70. These apparently indispensable general chaperones have proven to be highly useful molecular tracers of organellar origin. Phylogenetic relationships of Hsp90--a less conserved and less widely distributed general chaperone--are reported here that are strikingly incongruent with canonical patterns of endosymbiotic ancestry. It appears that Hsp90 of chloroplasts derives from the endoplasmic reticulum-specific isoform while mitochondrial Hsp90 homologs affiliate with a eubacterial lineage other than alpha subdivision of proteobacteria. These data suggest that endosymbiont htpG genes, encoding Hsp90, have been either functionally displaced by pre-existing nuclear genes or completely lost during establishment of organelles and subsequently added to initial organellar complement.}, }
@article {pmid12459246, year = {2003}, author = {Schabereiter-Gurtner, C and Lubitz, W and Rölleke, S}, title = {Application of broad-range 16S rRNA PCR amplification and DGGE fingerprinting for detection of tick-infecting bacteria.}, journal = {Journal of microbiological methods}, volume = {52}, number = {2}, pages = {251-260}, doi = {10.1016/s0167-7012(02)00186-0}, pmid = {12459246}, issn = {0167-7012}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Base Sequence ; Cloning, Molecular ; DNA Fingerprinting/*methods ; DNA, Bacterial/*analysis/classification ; Electrophoresis, Polyacrylamide Gel ; Ixodes/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/*methods ; RNA, Ribosomal, 16S/*genetics ; }, abstract = {Ticks play an important role in the transmission of arthropod-borne diseases of viral, protozoal and bacterial origin. The present article describes a molecular-biological based method, which facilitated the broad-range analyses of bacterial communities in ixodid ticks (Ixodes ricinus). DNA was extracted both from single ticks and pooled adult ticks. Eubacterial 16S rRNA gene fragments (16S rDNA) were amplified by polymerase chain reaction (PCR) with broad-range ribosomal primers. Sequences spanning the hypervariable V3 region of the 16S rDNA and representing individual bacterial taxons were separated by denaturing gradient gel electrophoresis (DGGE). For phylogenetic identification, DGGE bands were exised, cloned and sequenced. In addition, we set up a 16S rDNA clone library which was screened by DGGE. Sequences were compared with sequences of known bacteria listed in the GenBank database. A number of bacteria were affiliated with the genera Rickettsia, Bartonella, and Borrelia, which are known to be pathogenic and transmitted by ticks. Two sequences were related to the yet to be cultivated Haemobartonella. To our knowledge, Haemobartonella has never been directly detected in I. ricinus. In addition, members of the genera Staphylococcus, Rhodococcus, Pseudomonas, and Moraxella were detected, which have not been identified in ticks so far. Two bacteria were most closely related to a rickettsial endosymbiont of an Acanthamoeba sp., and to an endosymbiont (Legionellaceae, Coxiella group) of the microarthropod Folsomia candida. The results prove that 16S rDNA genotyping in combination with DGGE analysis is a promising approach for the detection and identification of bacteria infecting ticks, regardless of whether these bacteria are fastidious, obligate intracellular or noncultivable.}, }
@article {pmid12458769, year = {2002}, author = {Krastel, P and Zeeck, A and Gebhardt, K and Fiedler, HP and Rheinheimer, J}, title = {Endophenazines A-D, new phenazine antibiotics from the athropod associated endosymbiont Streptomyces anulatus II. Structure elucidation.}, journal = {The Journal of antibiotics}, volume = {55}, number = {9}, pages = {801-806}, doi = {10.7164/antibiotics.55.801}, pmid = {12458769}, issn = {0021-8820}, mesh = {Animals ; Anti-Bacterial Agents/*chemistry ; Arthropods/*microbiology ; Magnetic Resonance Spectroscopy ; Phenazines/*chemistry ; Streptomyces/*metabolism ; }, abstract = {A detailed screening of the secondary metabolite pattern produced by different athropod associated strains of the species Streptomyces anulatus resulted in the isolation and structure elucidation of the endophenazines A-D (2, 4-6). The structures were assigned by spectroscopic methods and chemical transformations. 4 represents a chromophoric system based on a phenazin-7-one, 5 and 6 are new 5,10-dihydrophenazine derivatives.}, }
@article {pmid12458768, year = {2002}, author = {Gebhardt, K and Schimana, J and Krastel, P and Dettner, K and Rheinheimer, J and Zeeck, A and Fiedler, HP}, title = {Endophenazines A-D, new phenazine antibiotics from the arthropod associated endosymbiont Streptomyces anulatus. I. Taxonomy, fermentation, isolation and biological activities.}, journal = {The Journal of antibiotics}, volume = {55}, number = {9}, pages = {794-800}, doi = {10.7164/antibiotics.55.794}, pmid = {12458768}, issn = {0021-8820}, mesh = {Animals ; Anti-Bacterial Agents/*isolation &amp; purification/pharmacology ; Arthropods/*microbiology ; Bacteria/drug effects ; *Fermentation ; Phenazines/*isolation &amp; purification/pharmacology ; Streptomyces/*classification/metabolism ; *Symbiosis ; }, abstract = {Four new members of the phenazine family, endophenazines A-D, and the already known phenazine-1-carboxylic acid (tubermycin B) were detected in the culture broth of various endosymbiotic Streptomyces anulatus strains by chemical screening in a combination of TLC-staining reagents and HPLC-diode array analysis. The endosymbiotic strains were isolated from four different arthropod hosts at various sites. The new phenazine compounds showed antimicrobial activities against Gram-positive bacteria and some filamentous fungi, and herbicidal activity against Lemna minor (duckweed).}, }
@article {pmid12456672, year = {2003}, author = {Gudlavalleti, SK and Forsberg, LS}, title = {Structural characterization of the lipid A component of Sinorhizobium sp. NGR234 rough and smooth form lipopolysaccharide. Demonstration that the distal amide-linked acyloxyacyl residue containing the long chain fatty acid is conserved in rhizobium and Sinorhizobium sp.}, journal = {The Journal of biological chemistry}, volume = {278}, number = {6}, pages = {3957-3968}, doi = {10.1074/jbc.M210491200}, pmid = {12456672}, issn = {0021-9258}, mesh = {Amides/*chemistry ; Carbohydrate Sequence ; Chromatography, Ion Exchange ; Chromatography, Thin Layer ; Fatty Acids/*chemistry ; Lipid A/*chemistry ; Lipopolysaccharides/*chemistry ; Magnetic Resonance Spectroscopy ; Molecular Sequence Data ; Molecular Structure ; Rhizobium/*chemistry ; Sinorhizobium/*chemistry ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; }, abstract = {A broad-host-range endosymbiont, Sinorhizobium sp. NGR234 is a component of several legume-symbiont model systems; however, there is little structural information on the cell surface glycoconjugates. NGR234 cells in free-living culture produce a major rough lipopolysaccharide (LPS, lacking O-chain) and a minor smooth LPS (containing O-chain), and the structure of the lipid A components was investigated by chemical analyses, mass spectrometry, and NMR spectroscopy of the underivatized lipids A. The lipid A from rough LPS is heterogeneous and consists of six major bisphosphorylated species that differ in acylation. Pentaacyl species (52%) are acylated at positions 2, 3, 2', and 3', and tetraacyl species (46%) lack an acyl group at C-3 of the proximal glucosamine. In contrast to Rhizobium etli and Rhizobium leguminosarum, the NGR234 lipid A contains a bisphosphorylated beta-(1' --> 6)-glucosamine disaccharide, typical of enterobacterial lipid A. However, NGR234 lipid A retains the unusual acylation pattern of R. etli lipid A, including the presence of a distal, amide-linked acyloxyacyl residue containing a long chain fatty acid (LCFA) (e.g. 29-hydroxytriacontanoate) attached as the secondary fatty acid. As in R. etli, a 4-carbon fatty acid, beta-hydroxybutyrate, is esterified to (omega - 1) of the LCFA forming an acyloxyacyl residue at that location. The NGR234 lipid A lacks all other ester-linked acyloxyacyl residues and shows extensive heterogeneity of the amide-linked fatty acids. The N-acyl heterogeneity, including unsaturation, is localized mainly to the proximal glucosamine. The lipid A from smooth LPS contains unique triacyl species (20%) that lack ester-linked fatty acids but retain bisphosphorylation and the LCFA-acyloxyacyl moiety. The unusual structural features shared with R. etli/R. leguminosarum lipid A may be essential for symbiosis.}, }
@article {pmid12455953, year = {2002}, author = {Nixon, JE and Wang, A and Field, J and Morrison, HG and McArthur, AG and Sogin, ML and Loftus, BJ and Samuelson, J}, title = {Evidence for lateral transfer of genes encoding ferredoxins, nitroreductases, NADH oxidase, and alcohol dehydrogenase 3 from anaerobic prokaryotes to Giardia lamblia and Entamoeba histolytica.}, journal = {Eukaryotic cell}, volume = {1}, number = {2}, pages = {181-190}, pmid = {12455953}, issn = {1535-9778}, support = {R01 AI046516/AI/NIAID NIH HHS/United States ; AI43273/AI/NIAID NIH HHS/United States ; R01 AI048082/AI/NIAID NIH HHS/United States ; AI46516/AI/NIAID NIH HHS/United States ; AI33492/AI/NIAID NIH HHS/United States ; }, mesh = {Alcohol Dehydrogenase/analysis/genetics ; Amino Acid Sequence ; Anaerobiosis ; Animals ; Bacteria/genetics ; Entamoeba histolytica/enzymology/*genetics ; Fermentation ; Ferredoxins/analysis/classification/*genetics ; *Gene Transfer, Horizontal ; Giardia lamblia/enzymology/*genetics ; Iron-Sulfur Proteins/genetics ; Mitochondria/genetics ; Models, Biological ; Molecular Sequence Data ; Multienzyme Complexes/analysis/genetics ; NADH, NADPH Oxidoreductases/analysis/genetics ; Nitroreductases/analysis/classification/genetics ; Oxidoreductases/*genetics ; Phylogeny ; Prokaryotic Cells/metabolism ; Sequence Alignment ; Sequence Analysis, Protein ; }, abstract = {Giardia lamblia and Entamoeba histolytica are amitochondriate, microaerophilic protists which use fermentation enzymes like those of bacteria to survive anaerobic conditions within the intestinal lumen. Genes encoding fermentation enzymes and related electron transport peptides (e.g., ferredoxins) in giardia organisms and amebae are hypothesized to be derived from either an ancient anaerobic eukaryote (amitochondriate fossil hypothesis), a mitochondrial endosymbiont (hydrogen hypothesis), or anaerobic bacteria (lateral transfer hypothesis). The goals here were to complete the molecular characterization of giardial and amebic fermentation enzymes and to determine the origins of the genes encoding them, when possible. A putative giardia [2Fe-2S]ferredoxin which had a hypothetical organelle-targeting sequence at its N terminus showed similarity to mitochondrial ferredoxins and the hydrogenosomal ferredoxin of Trichomonas vaginalis (another luminal protist). However, phylogenetic trees were star shaped, with weak bootstrap support, so we were unable to confirm or rule out the endosymbiotic origin of the giardia [2Fe-2S]ferredoxin gene. Putative giardial and amebic 6-kDa ferredoxins, ferredoxin-nitroreductase fusion proteins, and oxygen-insensitive nitroreductases each tentatively supported the lateral transfer hypothesis. Although there were not enough sequences to perform meaningful phylogenetic analyses, the unique common occurrence of these peptides and enzymes in giardia organisms, amebae, and the few anaerobic prokaryotes suggests the possibility of lateral transfer. In contrast, there was more robust phylogenetic evidence for the lateral transfer of G. lamblia genes encoding an NADH oxidase from a gram-positive coccus and a microbial group 3 alcohol dehydrogenase from thermoanaerobic prokaryotes. In further support of lateral transfer, the G. lamblia NADH oxidase and adh3 genes appeared to have an evolutionary history distinct from those of E. histolytica.}, }
@article {pmid12455749, year = {2002}, author = {Kroth, PG}, title = {Protein transport into secondary plastids and the evolution of primary and secondary plastids.}, journal = {International review of cytology}, volume = {221}, number = {}, pages = {191-255}, doi = {10.1016/s0074-7696(02)21013-x}, pmid = {12455749}, issn = {0074-7696}, mesh = {Endocytosis/physiology ; Eukaryota/*metabolism ; *Evolution, Molecular ; Intracellular Membranes/metabolism ; Plants/*metabolism ; Plastids/*metabolism ; Protein Transport/*physiology ; Signal Transduction/physiology ; }, abstract = {Chloroplasts are key organelles in algae and plants due to their photosynthetic abilities. They are thought to have evolved from prokaryotic cyanobacteria taken up by a eukaryotic host cell in a process termed primary endocytobiosis. In addition, a variety of organisms have evolved by subsequent secondary endocytobioses, in which a heterotrophic host cell engulfed a eukaryotic alga. Both processes dramatically enhanced the complexity of the resulting cells. Since the first version of the endosymbiotic theory was proposed more than 100 years ago, morphological, physiological, biochemical, and molecular data have been collected substantiating the emerging picture about the origin and the relationship of individual organisms with different primary or secondary chloroplast types. Depending on their origin, plastids in different lineages may have two, three, or four envelope membranes. The evolutionary success of endocytobioses depends, among other factors, on the specific exchange of molecules between the host and endosymbiont. This raises questions concerning how targeting of nucleus-encoded proteins into the different plastid types occurs and how these processes may have developed. Most studies of protein translocation into plastids have been performed on primary plastids, but in recent years more complex protein-translocation systems of secondary plastids have been investigated. Analyses of transport systems in different algal lineages with secondary plastids reveal that during evolution existing translocation machineries were recycled or recombined rather than being developed de novo. This review deals with current knowledge about the evolution and function of primary and secondary plastids and the respective protein-targeting systems.}, }
@article {pmid12453247, year = {2002}, author = {Abbot, P and Moran, NA}, title = {Extremely low levels of genetic polymorphism in endosymbionts (Buchnera) of aphids (Pemphigus).}, journal = {Molecular ecology}, volume = {11}, number = {12}, pages = {2649-2660}, doi = {10.1046/j.1365-294x.2002.01646.x}, pmid = {12453247}, issn = {0962-1083}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; Buchnera/*genetics ; DNA, Bacterial/chemistry/*genetics ; DNA, Mitochondrial/chemistry/genetics ; Electron Transport Complex IV/chemistry/genetics ; Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; United States ; }, abstract = {Molecular evolutionary studies have suggested that vertically transmitted endosymbionts are subject to accumulation of deleterious mutations through genetic drift. Predictions of this hypothesis for patterns of intraspecific polymorphism were borne out in the single relevant study available, on the symbiont Buchnera aphidicola of Uroleucon ambrosiae. In order to examine the generality of this result, we surveyed DNA sequence variation in Buchnera of the distantly related aphid, Pemphigus obesinymphae. In contrast to Uroleucon species, Pemphigus species have complex life cycles with few dispersal stages. Despite these differences, P. obesinymphae showed patterns of variation at two Buchnera loci and one mitochondrial locus that were remarkably similar to those reported previously for Buchnera of U. ambrosiae. In the western US, Buchnera was nearly monomorphic, and in the eastern US, synonymous divergence ranged from 0.08 to 0.16%. Most polymorphisms involved rare alleles, consistent with a recent range of ancestral polymorphism, probably due to demographic fluctuations in aphid populations. These results support the generality of small effective population size in Buchnera and their aphid hosts.}, }
@article {pmid12450854, year = {2002}, author = {Distel, DL and Beaudoin, DJ and Morrill, W}, title = {Coexistence of multiple proteobacterial endosymbionts in the gills of the wood-boring Bivalve Lyrodus pedicellatus (Bivalvia: Teredinidae).}, journal = {Applied and environmental microbiology}, volume = {68}, number = {12}, pages = {6292-6299}, pmid = {12450854}, issn = {0099-2240}, mesh = {Animals ; Gills/microbiology ; In Situ Hybridization, Fluorescence ; Mollusca/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; Proteobacteria/classification/*growth &amp; development ; RNA, Ribosomal, 16S ; Ribotyping ; *Symbiosis ; }, abstract = {Wood-boring bivalves of the family Teredinidae (commonly called shipworms) are known to harbor dense populations of gram-negative bacteria within specialized cells (bacteriocytes) in their gills. These symbionts are thought to provide enzymes, e.g., cellulase and dinitrogenase, which assist the host in utilizing wood as a primary food source. A cellulolytic, dinitrogen-fixing bacterium, Teredinibacter turnerae, has been isolated from the gill tissues of numerous teredinid bivalves and has been proposed to constitute the sole or predominant symbiont of this bivalve family. Here we demonstrate that one teredinid species, Lyrodus pedicellatus, contains at least four distinct bacterial 16S rRNA types within its gill bacteriocytes, one of which is identical to that of T. turnerae. Phylogenetic analyses indicate that the three newly detected ribotypes are derived from gamma proteobacteria that are related to but distinct (>6.5% sequence divergence) from T. turnerae. In situ hybridizations with 16S rRNA-directed probes demonstrated that the pattern of occurrence of symbiont ribotypes within bacteriocytes was predictable and specific, with some bacteriocytes containing two symbiont ribotypes. However, only two of the six possible pairwise combinations of the four ribotypes were observed to cooccur within the same host cells. The results presented here are consistent with the existence of a complex multiple symbiosis in this shipworm species.}, }
@article {pmid12450827, year = {2002}, author = {Beier, CL and Horn, M and Michel, R and Schweikert, M and Görtz, HD and Wagner, M}, title = {The genus Caedibacter comprises endosymbionts of Paramecium spp. related to the Rickettsiales (Alphaproteobacteria) and to Francisella tularensis (Gammaproteobacteria).}, journal = {Applied and environmental microbiology}, volume = {68}, number = {12}, pages = {6043-6050}, pmid = {12450827}, issn = {0099-2240}, mesh = {Acanthamoeba/microbiology ; Alphaproteobacteria/*classification ; Animals ; Francisella tularensis/*classification ; Paramecium/*microbiology ; Phylogeny ; Proteobacteria/*classification ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Obligate bacterial endosymbionts of paramecia able to form refractile inclusion bodies (R bodies), thereby conferring a killer trait upon their ciliate hosts, have traditionally been grouped into the genus CAEDIBACTER: Of the six species described to date, only the Paramecium caudatum symbiont Caedibacter caryophilus has been phylogenetically characterized by its 16S rRNA gene sequence, and it was found to be a member of the Alphaproteobacteria related to the RICKETTSIALES: In this study, the Caedibacter taeniospiralis type strain, an R-body-producing cytoplasmatic symbiont of Paramecium tetraurelia strain 51k, was investigated by comparative 16S rRNA sequence analysis and fluorescence in situ hybridization with specific oligonucleotide probes. C. taeniospiralis is not closely related to C. caryophilus (80% 16S rRNA sequence similarity) but forms a novel evolutionary lineage within the Gammaproteobacteria with the family Francisellaceae as a sister group (87% 16S rRNA sequence similarity). These findings demonstrate that the genus Caedibacter is polyphyletic and comprises at least two phylogenetically different bacterial species belonging to two different classes of the PROTEOBACTERIA: Comparative phylogenetic analysis of C. caryophilus, five closely related Acanthamoeba endosymbionts (including one previously uncharacterized amoebal symbiont identified in this study), and their hosts suggests that the progenitor of the alphaproteobacterial C. caryophilus lived within acanthamoebae prior to the infection of paramecia.}, }
@article {pmid12449636, year = {2002}, author = {Pimenov, NV and Kaliuzhnaia, MG and Khmelenina, VN and Mitiushina, LL and Trotsenko, IuA}, title = {[Utilization of methane and carbon dioxide by symbiotrophic bacteria in gills of Mytilidae (Bathymodiolus) from the Rainbow and Logachev hydrothermal fields on the Mid-Atlantic Ridge].}, journal = {Mikrobiologiia}, volume = {71}, number = {5}, pages = {681-689}, pmid = {12449636}, issn = {0026-3656}, mesh = {Alcohol Oxidoreductases/analysis ; Aldehyde-Lyases/metabolism ; Animals ; Atlantic Ocean ; Carbon Dioxide/metabolism ; Gills/microbiology ; Methane/metabolism ; Methylobacterium/genetics/isolation &amp; purification/*metabolism ; Methylococcaceae/genetics/isolation &amp; purification/*metabolism ; Microscopy, Electron ; Mollusca/*microbiology ; Oxygenases/analysis ; Phosphotransferases (Alcohol Group Acceptor)/metabolism ; Polymerase Chain Reaction ; Ribulose-Bisphosphate Carboxylase/metabolism ; Symbiosis ; }, abstract = {Bivalve mollusks Bathymodiolus asoricus and Bathymodiolus puteoserpentis collected from the Rainbow and Logachev hydrothermal fields during dives of Mir 1 and Mir 2 deep-sea manned submersibles were studied. Rates of methane oxidation and carbon dioxide assimilation in mussel gill tissue were determined by radiolabel analysis. During oxidation of 14Ch4, radiocarbon was detected in significant quantities not only in carbon dioxide but also in dissolved organic matter, most notably 14C-formate and 14C-acetate, occurring in a 2:1 ratio. Activities of hexulose-phosphate synthase, phosphoribulokinase, and ribulose 1,5-bisphosphate carboxylase were shown in the soluble fraction of gill tissue cells. At the same time, no activity of hydroxypyruvate reductase--the key enzyme of the serine pathway of C1-assimilation--was detected. The results of PCR amplification using genetic probes for membrane-bound methane monooxygenase (pmoA) and methanol dehydrogenase (mxaF) attest to the presence of the genes of these enzymes in the total DNA extracted from gill samples. However, no appropriate PCR responses were obtained with the mmoX primer system, which is a marker for soluble methane monooxygenase. All samples studied showed amplification with primers for the genera Methylobacter and Methylosphaera. At the same time, no genes specific to the genera Methylomonas, Methylococcus, Methylomicrobium, or Methylosinus and Methylocystis were detected. Electron microscopic examinations revealed the presence of two groups of endosymbiotic bacteria in the mussel gill tissue. The first group was represented by large cells possessing a complex system of cytoplasmic membranes, typical of methanotrophs of morphotype I. The other type of endosymbionts, having much smaller cells and lacking intracellular membrane structures, is likely to be constituted by sulfur bacteria.}, }
@article {pmid12442548, year = {2002}, author = {Litoshenko, AIa}, title = {[Evolution of mitochondria].}, journal = {TSitologiia i genetika}, volume = {36}, number = {5}, pages = {49-57}, pmid = {12442548}, issn = {0564-3783}, mesh = {DNA, Mitochondrial/genetics ; Eukaryotic Cells ; *Evolution, Molecular ; Mitochondria/*genetics ; Phylogeny ; Symbiosis ; }, abstract = {Until recently, the origin and evolution of mitochondria was explained by the serial endosymbiosis hypothesis. This hypothesis posits that contemporary mitochondria are the direct descendants of a bacterial endosymbiont, which was settled in a nucleus-containing amitochondriate host cell. Results of the mitochondrial gene sequences support a monophyletic origin of the mitochondria from a single eubacterial ancestor shared with a subdivision of the alpha-proteobacteria. In recent years, the complete sequences of the vast variety of mitochondrial and eubacterial genomes were determined. These data indicate that the mitochondrial genome evolved from a common ancestor of all extant eukaryotes and assume a possibility that the mitochondrial and nuclear constituents of the eukaryotic cell originated simultaneously.}, }
@article {pmid12415315, year = {2002}, author = {Wernegreen, JJ}, title = {Genome evolution in bacterial endosymbionts of insects.}, journal = {Nature reviews. Genetics}, volume = {3}, number = {11}, pages = {850-861}, doi = {10.1038/nrg931}, pmid = {12415315}, issn = {1471-0056}, mesh = {Animals ; Bacteria/classification/*genetics ; *Evolution, Molecular ; Genetic Drift ; *Genome, Bacterial ; Genomics ; Insecta/genetics/*microbiology ; Mutation ; Phylogeny ; *Symbiosis ; }, abstract = {Many insect species rely on intracellular bacterial symbionts for their viability and fecundity. Large-scale DNA-sequence analyses are revealing the forces that shape the evolution of these bacterial associates and the genetic basis of their specialization to an intracellular lifestyle. The full genome sequences of two obligate mutualists, Buchnera aphidicola of aphids and Wigglesworthia glossinidia of tsetse flies, reveal substantial gene loss and an integration of host and symbiont metabolic functions. Further genomic comparisons should reveal the generality of these features among bacterial mutualists and the extent to which they are shared with other intracellular bacteria, including obligate pathogens.}, }
@article {pmid12402526, year = {2001}, author = {Simoncini, L and Casiraghi, M and Bazzocchi, C and Sacchi, L and Bandi, C and Genchi, C}, title = {Real-time PCR for quantification of the bacterial endosymbionts (Wolbachia) of filarial nematodes.}, journal = {Parassitologia}, volume = {43}, number = {4}, pages = {173-178}, pmid = {12402526}, issn = {0048-2951}, mesh = {Animals ; Bacterial Proteins/genetics ; Brugia pahangi/*microbiology ; Computer Systems ; *Cytoskeletal Proteins ; DNA, Bacterial/*analysis ; Dirofilaria immitis/*microbiology ; Dirofilariasis/parasitology ; Dog Diseases/parasitology ; Dogs ; Female ; Gerbillinae/parasitology ; Male ; Polymerase Chain Reaction/*methods ; Reproducibility of Results ; Symbiosis ; Tetracycline/pharmacology ; Wolbachia/drug effects/genetics/*isolation &amp; purification ; }, abstract = {Filarial nematodes harbour intracellular symbiotic bacteria belonging to the genus Wolbachia. Wolbachia is thought to play an important role in the biology of the nematode. Moreover, Wolbachia appears to be involved in the immunopathogenesis of filariasis and in the onset of the side-effects of antifilarial therapy. Investigations in these research areas require reliable methods to quantify Wolbachia both in nematodes and in vertebrate tissues. To this purpose, we designed a quantitative real-time PCR targeted on the ftsZ gene of the Wolbachia of Brugia pahangi, a model filarial species maintained in gerbils. The method was applied to quantify Wolbachia in Brugia pahangi, from animals with or without tetracycline treatment. Our results show that tetracycline treatment leads to dramatic reduction or clearance of Wolbachia from the nematode. Results obtained from different replicates were reproducible and the method appeared very sensitive compared to other PCR protocols for Wolbachia detection. Real-time PCR is thus an appropriate method for investigations on the biological role of Wolbachia and on the implication of these bacteria in the pathogenesis of filariasis. With slight modifications of the primers and probe, the protocol we have developed could be applied in studies of the human pathogen Brugia malayi and on the model filarial species Litomosoides sigmodontis.}, }
@article {pmid12396501, year = {2002}, author = {van Borm, S and Buschinger, A and Boomsma, JJ and Billen, J}, title = {Tetraponera ants have gut symbionts related to nitrogen-fixing root-nodule bacteria.}, journal = {Proceedings. Biological sciences}, volume = {269}, number = {1504}, pages = {2023-2027}, pmid = {12396501}, issn = {0962-8452}, mesh = {Animals ; Ants/anatomy &amp; histology/*microbiology/ultrastructure ; Bacteria/*genetics/*isolation &amp; purification/ultrastructure ; Female ; Intestines/anatomy &amp; histology/microbiology/ultrastructure ; Male ; *Nitrogen Fixation ; *Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Some Tetraponera ants (Formicidae, Pseudomyrmecinae) subsist almost entirely on amino acid deficient honeydew secretions of pseudococcids and harbour a dense aggregation of bacterial symbionts in a unique pouch-shaped organ at the junction of the midgut and the intestine. The organ is surrounded by a network of intruding tracheae and Malpighian tubules, suggesting that these bacteria are involved in the oxidative recycling of nitrogen-rich metabolic waste. We have examined the ultrastructure of these bacteria and have amplified, cloned and sequenced ribosomal RNA-encoding genes, showing that the ant pouch contains a series of close relatives of Flavobacteria and Rhizobium, Methylobacterium, Burkholderia and Pseudomonas nitrogen-fixing root-nodule bacteria. We argue that pouch bacteria have been repeatedly 'domesticated' by the ants as nitrogen-recycling endosymbionts. This ant-associated community of mutualists is, to our knowledge, the first finding of symbionts related to root-nodule bacteria in animals.}, }
@article {pmid12386340, year = {2002}, author = {Kondo, N and Nikoh, N and Ijichi, N and Shimada, M and Fukatsu, T}, title = {Genome fragment of Wolbachia endosymbiont transferred to X chromosome of host insect.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {22}, pages = {14280-14285}, pmid = {12386340}, issn = {0027-8424}, mesh = {Animals ; Base Sequence ; Blotting, Southern/methods ; Coleoptera/*genetics ; DNA, Bacterial ; Drosophila melanogaster/microbiology ; Drug Resistance, Bacterial ; Evolution, Molecular ; Female ; *Gene Transfer, Horizontal ; Genes, Bacterial ; *Genome, Bacterial ; Male ; Molecular Sequence Data ; Polymerase Chain Reaction/methods ; Rifampin/pharmacology ; Symbiosis ; Tetracycline/pharmacology ; Wolbachia/drug effects/*genetics/isolation &amp; purification ; *X Chromosome ; }, abstract = {The adzuki bean beetle, Callosobruchus chinensis, is triple-infected with distinct lineages of Wolbachia endosymbiont, wBruCon, wBruOri, and wBruAus, which were identified by their wsp (Wolbachia surface protein) gene sequences. Whereas wBruCon and wBruOri caused cytoplasmic incompatibility of the host insect, wBruAus did not. Although wBruCon and wBruOri were easily eliminated by antibiotic treatments, wBruAus persisted over five treated generations and could not be eliminated. The inheritance pattern of wBruAus was, surprisingly, explained by sex-linked inheritance in male-heterozygotic organisms, which agreed with the karyotype of C. chinensis (2n = 20, XY). Quantitative PCR analysis demonstrated that females contain around twice as much wsp titer as males, which is concordant with an X chromosome linkage. Specific PCR and Southern blot analyses indicated that the wBruAus-bearing strain of C. chinensis contains only a fraction of the Wolbachia gene repertoire. Several genome fragments of wBruAus were isolated using an inverse PCR technique. The fragments exhibited a bacterial genome structure containing a number of ORFs typical of the alpha-proteobacteria, although some of the ORFs contained disruptive mutations. In the flanking region of ftsZ gene, a non-long terminal repeat (non-LTR) retrotransposon sequence, which is typical of insects but not found from bacteria, was present. These results strongly suggest that wBruAus has no microbial entity but is a genome fragment of Wolbachia endosymbiont transferred to the X chromosome of the host insect.}, }
@article {pmid12385978, year = {2002}, author = {Andersson, SG and Alsmark, C and Canbäck, B and Davids, W and Frank, C and Karlberg, O and Klasson, L and Antoine-Legault, B and Mira, A and Tamas, I}, title = {Comparative genomics of microbial pathogens and symbionts.}, journal = {Bioinformatics (Oxford, England)}, volume = {18 Suppl 2}, number = {}, pages = {S17}, doi = {10.1093/bioinformatics/18.suppl_2.s17}, pmid = {12385978}, issn = {1367-4803}, mesh = {Alphaproteobacteria/genetics ; Chromosome Mapping/*methods ; *Evolution, Molecular ; Gammaproteobacteria/genetics ; Gene Transfer, Horizontal/genetics ; Genetic Variation/*genetics ; *Genome, Bacterial ; Genomic Instability/genetics ; Genomics/methods ; *Models, Genetic ; Mutation ; Phylogeny ; Proteobacteria/classification/*genetics ; Sequence Analysis, DNA/methods ; Species Specificity ; Symbiosis/*genetics ; }, abstract = {We are interested in quantifying the contribution of gene acquisition, loss, expansion and rearrangements to the evolution of microbial genomes. Here, we discuss factors influencing microbial genome divergence based on pair-wise genome comparisons of closely related strains and species with different lifestyles. A particular focus is on intracellular pathogens and symbionts of the genera Rickettsia, Bartonella and BUCHNERA: Extensive gene loss and restricted access to phage and plasmid pools may provide an explanation for why single host pathogens are normally less successful than multihost pathogens. We note that species-specific genes tend to be shorter than orthologous genes, suggesting that a fraction of these may represent fossil-orfs, as also supported by multiple sequence alignments among species. The results of our genome comparisons are placed in the context of phylogenomic analyses of alpha and gamma proteobacteria. We highlight artefacts caused by different rates and patterns of mutations, suggesting that atypical phylogenetic placements can not a priori be taken as evidence for horizontal gene transfer events. The flexibility in genome structure among free-living microbes contrasts with the extreme stability observed for the small genomes of aphid endosymbionts, in which no rearrangements or inflow of genetic material have occurred during the past 50 millions years (1). Taken together, the results suggest that genomic stability correlate with the content of repeated sequences and mobile genetic elements, and thereby indirectly with bacterial lifestyles.}, }
@article {pmid12383434, year = {2002}, author = {Ganassi, S and Moretti, A and Bonvicini Pagliai, AM and Logrieco, A and Agnese Sabatini, M}, title = {Effects of beauvericin on Schizaphis graminum (Aphididae).}, journal = {Journal of invertebrate pathology}, volume = {80}, number = {2}, pages = {90-96}, doi = {10.1016/s0022-2011(02)00125-8}, pmid = {12383434}, issn = {0022-2011}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Aphids/*drug effects/*physiology ; *Depsipeptides ; Female ; *Peptides ; }, abstract = {The effects of beauvericin, a toxic fungal metabolite common contaminant of maize and wheat, on aphid fitness were studied in three consecutive generations of females. Aphids were reared on wheat leaves inserted into a sandy substratum wetted with a solution of beauvericin. Ingestion of this solution through leaves did not significantly decrease the lifespan of females of all generations as compared to controls. However, the mean number of offspring from the third generation of treated females was significantly smaller than those in controls. Furthermore, treated second and third generation females produced a greater number of abortive embryos. Histological analysis revealed abundant DAPI and Feulgen positive material in the cytoplasm of some bacteriocytes of treated third generation females. This material was attributed to the endosymbionts of bacteriocytes. Tests by contact were also carried out and revealed a significantly lower survival of treated first instar aphids as compared to controls 18h after the start of the trial.}, }
@article {pmid12296954, year = {2002}, author = {Tsuchida, T and Koga, R and Shibao, H and Matsumoto, T and Fukatsu, T}, title = {Diversity and geographic distribution of secondary endosymbiotic bacteria in natural populations of the pea aphid, Acyrthosiphon pisum.}, journal = {Molecular ecology}, volume = {11}, number = {10}, pages = {2123-2135}, doi = {10.1046/j.1365-294x.2002.01606.x}, pmid = {12296954}, issn = {0962-1083}, mesh = {Animals ; Aphids/*microbiology ; DNA, Ribosomal/analysis ; Female ; Genetic Variation/*genetics ; *Genetics, Population ; Japan ; Peas/*parasitology ; Polymerase Chain Reaction ; Proteobacteria/*classification/genetics/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Spiroplasma/*classification/genetics/isolation &amp; purification ; Symbiosis ; }, abstract = {In addition to the essential intracellular symbiotic bacterium Buchnera, several facultative endosymbiotic bacteria called collectively secondary symbionts (S-symbionts) have been identified from the pea aphid Acyrthosiphon pisum. We conducted an extensive and systematic survey of S-symbionts in Japanese local populations of A. pisum using a specific PCR detection technique. Five S-symbionts of A. pisum, PASS, PAUS, PABS, Rickettsia and Spiroplasma, and two facultative endosymbionts universally found in various insects, Wolbachia and Arsenophonus, were targeted. Of 119 isofemale strains originating from 81 localities, 66.4% of the strains possessed either of four S-symbionts: PASS (38.7%); PAUS (16.0%); Rickettsia (8.4%); and Spiroplasma (3.4%), while 33.6% of the strains contained only Buchnera. PABS, Wolbachia and Arsenophonus were not detected from the Japanese strains of A. pisum. In order to understand intra- and interpopulational diversity of S-symbiont microbiota in detail, 858 insects collected from 43 localities were examined for infection with the four S-symbionts. It was demonstrated that different S-symbionts coexist commonly in the same local populations, but double infections with two S-symbionts were rarely detected. Notably, the S-symbionts exhibited characteristic geographical distribution patterns: PASS at high frequencies all over Japan; PAUS at high frequencies mainly in the northeastern part of Japan; and Rickettsia and Spiroplasma at low frequencies sporadically in the southwestern part of Japan. These results indicate that the geographical distribution and infection frequency of the S-symbionts, in particular PAUS, might be affected by environmental and/or historical factors. Statistical analyses suggested that the distribution of PAUS infection might be related to host plant species, temperature and precipitation.}, }
@article {pmid12243453, year = {2002}, author = {Schlörke, O and Krastel, P and Müller, I and Usón, I and Dettner, K and Zeeck, A}, title = {Structure and biosynthesis of cetoniacytone A, a cytotoxic aminocarba sugar produced by an endosymbiontic Actinomyces.}, journal = {The Journal of antibiotics}, volume = {55}, number = {7}, pages = {635-642}, doi = {10.7164/antibiotics.55.635}, pmid = {12243453}, issn = {0021-8820}, mesh = {Actinomyces/*chemistry/metabolism ; Antineoplastic Agents/chemistry/isolation &amp; purification/metabolism/pharmacology ; Crystallography, X-Ray ; Culture Media ; Cyclohexanones/*chemistry/isolation &amp; purification/metabolism/*pharmacology ; Drug Screening Assays, Antitumor ; Fermentation ; Glucose/metabolism ; Glycerol/metabolism ; Magnetic Resonance Spectroscopy ; Microbial Sensitivity Tests ; Molecular Structure ; Symbiosis ; Tumor Cells, Cultured ; }, abstract = {Cetoniacytone A (1) and some related minor components (2, 6, 7) were produced by Actinomyces sp. (strain Lu 9419), which was isolated from the intestines of a rose chafer (Cetonia aureata). The structures of the novel metabolites were established by detailed spectroscopic analysis. The absolute configuration of 1 was determined by X-ray analysis and derivatisation with chiral acids. 1 exhibits a significant cytotoxicity against selected tumor cell lines. The biosynthesis of 1 was studied by feeding 13C labelled precursors. The results suggest that the characteristic p-C7N skeleton of the aminocarba sugar is formed via the pentose phosphate pathway by cyclisation of a heptulose phosphate intermediate.}, }
@article {pmid12235368, year = {2002}, author = {Itoh, T and Martin, W and Nei, M}, title = {Acceleration of genomic evolution caused by enhanced mutation rate in endocellular symbionts.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {20}, pages = {12944-12948}, pmid = {12235368}, issn = {0027-8424}, support = {R01 GM020293/GM/NIGMS NIH HHS/United States ; GM 20293/GM/NIGMS NIH HHS/United States ; }, mesh = {Buchnera/*genetics ; Databases as Topic ; Escherichia coli/genetics ; *Evolution, Molecular ; Haemophilus influenzae/genetics ; *Mutation ; Phylogeny ; RNA, Ribosomal, 16S/metabolism ; }, abstract = {Endosymbionts, which are widely observed in nature, have undergone reductive genome evolution because of their long-term intracellular lifestyle. Here we compared the complete genome sequences of two different endosymbionts, Buchnera and a protist mitochondrion, with their close relatives to study the evolutionary rates of functional genes in endosymbionts. The results indicate that the rate of amino acid substitution is two times higher in symbionts than in their relatives. This rate increase was observed uniformly among different functional classes of genes, although strong purifying selection may have counterbalanced the rate increase in a few cases. Our data suggest that, contrary to current views, neither the Muller's ratchet effect nor the slightly deleterious mutation theory sufficiently accounts for the elevated evolutionary rate. Rather, the elevated evolutionary rate appears to be mainly due to enhanced mutation rate, although the possibility of relaxation of purifying selection cannot be ruled out.}, }
@article {pmid12234537, year = {2002}, author = {Grenier, S and Gomes, SM and Pintureau, B and Lassablière, F and Bolland, P}, title = {Use of tetracycline in larval diet to study the effect of Wolbachia on host fecundity and clarify taxonomic status of Trichogramma species in cured bisexual lines.}, journal = {Journal of invertebrate pathology}, volume = {80}, number = {1}, pages = {13-21}, doi = {10.1016/s0022-2011(02)00039-3}, pmid = {12234537}, issn = {0022-2011}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Crosses, Genetic ; Female ; Fertility/drug effects ; Larva/drug effects/microbiology ; Male ; Tetracycline/*pharmacology ; Wasps/drug effects/*microbiology ; Wolbachia/*physiology ; }, abstract = {Endosymbionts of the genus Wolbachia were efficiently cured from Trichogramma species by incorporating 0.02% tetracycline into the artificial diet used to rear larvae. Use of this technique yielded stable cured lines (bisexual and arrhenotokous lines) in which no Wolbachia organisms were detected by PCR for up to 14 generations after curing. Four cured strains of Trichogramma pretiosum showed a significantly lower total fecundity compared to their Wolbachia-infected counterpart. However, the fecundity of a single cured strain of Trichogramma evanescens was similar to its Wolbachia-infected counterpart. These differences in the effect on fecundity may be due to differences between the Wolbachia strains infecting T. pretiosum or T. evanescens, providing additional evidence for the hypothesis that a specific interaction exists between some Trichogramma species and their Wolbachia symbionts. Tetracycline in larval diet was also used to generate bisexual strains of Trichogramma oleae and Trichogramma cordubensis so that these species could be crossed with the closely related species, respectively, T. pretiosum and T. evanescens, to test their compatibility. These crosses showed a lack of compatibility, validating maintenance of these as distinct species.}, }
@article {pmid12234008, year = {2002}, author = {Piñón, D and Casas, M and Blanch, M and Fontaniella, B and Blanco, Y and Vicente, C and Solas, MT and Legaz, ME}, title = {Gluconacetobacter diazotrophicus, a sugar cane endosymbiont, produces a bacteriocin against Xanthomonas albilineans, a sugar cane pathogen.}, journal = {Research in microbiology}, volume = {153}, number = {6}, pages = {345-351}, doi = {10.1016/s0923-2508(02)01336-0}, pmid = {12234008}, issn = {0923-2508}, mesh = {Acetobacteraceae/*metabolism/physiology ; Bacteriocins/*biosynthesis/pharmacology ; Electrophoresis, Polyacrylamide Gel ; Pest Control, Biological ; Plant Diseases/microbiology ; Poaceae/*microbiology ; Symbiosis ; Xanthomonas/drug effects/*physiology/ultrastructure ; }, abstract = {Gluconacetobacter diazotrophicus in liquid culture secretes proteins into the medium. Both medium containing Gluconacetobacter protein and a solution of this protein after acetone precipitation appeared to inhibit the growth of Xanthomonas albilineans in solid culture. This apparent inhibition of bacterial growth has, in fact, been revealed to be lysis of bacterial cells, as demonstrated by transmission electron microscopy. Fractionation of the Gluconacetobacter protein mixture in size-exclusion chromatography reveals a main fraction with lysozyme-like activity which produces lysis of both living bacteria and isolated cell walls.}, }
@article {pmid12221039, year = {2003}, author = {Normark, BB}, title = {The evolution of alternative genetic systems in insects.}, journal = {Annual review of entomology}, volume = {48}, number = {}, pages = {397-423}, doi = {10.1146/annurev.ento.48.091801.112703}, pmid = {12221039}, issn = {0066-4170}, mesh = {Animals ; *Biological Evolution ; Diploidy ; Disorders of Sex Development ; Extrachromosomal Inheritance ; Female ; Haploidy ; Insecta/*genetics/microbiology ; Male ; Models, Genetic ; Parthenogenesis ; Sex Determination Processes ; Wolbachia/genetics ; }, abstract = {There are three major classes of insect genetic systems: those with diploid males (diplodiploidy), those with effectively haploid males (haplodiploidy), and those without males (thelytoky). Mixed systems, involving cyclic or facultative switching between thelytoky and either of the other systems, also occur. I present a classification of the genetic systems of insects and estimate the number of evolutionary transitions between them that have occurred. Obligate thelytoky has arisen from each of the other systems, and there is evidence that over 900 such origins have occurred. The number of origins of facultative thelytoky and the number of reversions from obligate thelytoky to facultative and cyclic thelytoky are difficult to estimate. The other transitions are few in number: five origins of cyclic thelytoky, eight origins of obligate haplodiploidy (including paternal genome elimination), the strange case of Micromalthus, and the two reversions from haplodiploidy to diplodiploidy in scale insects. Available evidence tends to support W.D. Hamilton's hypothesis that maternally transmitted endosymbionts have been involved in the origins of haplodiploidy. Bizarre systems of extrazygotic inheritance in Sternorrhyncha are not easily accommodated into any existing classification of genetic systems.}, }
@article {pmid12218172, year = {2002}, author = {Martin, W and Rujan, T and Richly, E and Hansen, A and Cornelsen, S and Lins, T and Leister, D and Stoebe, B and Hasegawa, M and Penny, D}, title = {Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastid phylogeny and thousands of cyanobacterial genes in the nucleus.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {19}, pages = {12246-12251}, pmid = {12218172}, issn = {0027-8424}, mesh = {Arabidopsis/*genetics/*microbiology ; Arabidopsis Proteins/genetics ; *Biological Evolution ; Cell Nucleus/genetics/microbiology ; Chloroplasts/*genetics/microbiology ; Cyanobacteria/*genetics ; Gene Transfer, Horizontal ; Genes, Bacterial ; Genome, Bacterial ; Genome, Plant ; Models, Genetic ; Multigene Family ; Phylogeny ; Plastids/genetics/microbiology ; }, abstract = {Chloroplasts were once free-living cyanobacteria that became endosymbionts, but the genomes of contemporary plastids encode only approximately 5-10% as many genes as those of their free-living cousins, indicating that many genes were either lost from plastids or transferred to the nucleus during the course of plant evolution. Previous estimates have suggested that between 800 and perhaps as many as 2,000 genes in the Arabidopsis genome might come from cyanobacteria, but genome-wide phylogenetic surveys that could provide direct estimates of this number are lacking. We compared 24,990 proteins encoded in the Arabidopsis genome to the proteins from three cyanobacterial genomes, 16 other prokaryotic reference genomes, and yeast. Of 9,368 Arabidopsis proteins sufficiently conserved for primary sequence comparison, 866 detected homologues only among cyanobacteria and 834 other branched with cyanobacterial homologues in phylogenetic trees. Extrapolating from these conserved proteins to the whole genome, the data suggest that approximately 4,500 of Arabidopsis protein-coding genes (approximately 18% of the total) were acquired from the cyanobacterial ancestor of plastids. These proteins encompass all functional classes, and the majority of them are targeted to cell compartments other than the chloroplast. Analysis of 15 sequenced chloroplast genomes revealed 117 nuclear-encoded proteins that are also still present in at least one chloroplast genome. A phylogeny of chloroplast genomes inferred from 41 proteins and 8,303 amino acids sites indicates that at least two independent secondary endosymbiotic events have occurred involving red algae and that amino acid composition bias in chloroplast proteins strongly affects plastid genome phylogeny.}, }
@article {pmid12213957, year = {2002}, author = {Dale, C and Plague, GR and Wang, B and Ochman, H and Moran, NA}, title = {Type III secretion systems and the evolution of mutualistic endosymbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {19}, pages = {12397-12402}, pmid = {12213957}, issn = {0027-8424}, support = {R01 GM056120/GM/NIGMS NIH HHS/United States ; GM56120/GM/NIGMS NIH HHS/United States ; }, mesh = {Adhesins, Bacterial/genetics ; Animals ; Antigens, Bacterial/genetics ; Base Sequence ; *Biological Evolution ; Cloning, Molecular ; Coleoptera/*genetics/*microbiology/physiology ; DNA, Bacterial/genetics ; Enterobacteriaceae/*genetics/*physiology ; Gene Expression ; Genes, Bacterial ; Molecular Sequence Data ; Phylogeny ; Symbiosis/*genetics ; }, abstract = {The view that parasites can develop cooperative symbiotic relationships with their hosts is both appealing and widely held; however, there is no molecular genetic evidence of such a transition. Here we demonstrate that a mutualistic bacterial endosymbiont of grain weevils maintains and expresses inv/spa genes encoding a type III secretion system homologous to that used for invasion by bacterial pathogens. Phylogenetic analyses indicate that inv/spa genes were present in presymbiotic ancestors of the weevil endosymbionts, occurring at least 50 million years ago. The function of inv/spa genes in maintaining symbiosis is demonstrated by the up-regulation of their expression under both in vivo and in vitro conditions that coincide with host cell invasion.}, }
@article {pmid12208043, year = {2002}, author = {Egyed, Z and Sréter, T and Széll, Z and Nyiro, G and Márialigeti, K and Varga, I}, title = {Molecular phylogenetic analysis of Onchocerca lupi and its Wolbachia endosymbiont.}, journal = {Veterinary parasitology}, volume = {108}, number = {2}, pages = {153-161}, doi = {10.1016/s0304-4017(02)00186-3}, pmid = {12208043}, issn = {0304-4017}, mesh = {Animals ; Bacterial Outer Membrane Proteins/chemistry/genetics ; Bacterial Proteins/chemistry/genetics ; Base Sequence ; *Cytoskeletal Proteins ; Dog Diseases/parasitology ; Dogs ; Electron Transport Complex IV/chemistry/genetics ; Molecular Sequence Data ; Onchocerca/*genetics/growth &amp; development ; Onchocerciasis, Ocular/parasitology/veterinary ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Symbiosis ; Wolbachia/*genetics ; }, abstract = {The morphology of Onchocerca lupi, responsible for canine ocular onchocercosis, is unique within the genus. Earlier analyses of the 5S ribosomal RNA gene spacer region sequence of the parasite and the 16S ribosomal RNA gene sequence of its Wolbachia endosymbiotic bacteria (Rickettsiales) supported the morphological and biological arguments that O. lupi is a distinct species. However, the exact phylogenetic position of O. lupi and its endosymbiont could not be unambiguously determined. Herein we report analyses based on the mitochondrial cytochrome oxidase I (COI) gene of the filarial species and the Wolbachia surface protein (wsp) and the bacterial cell-cycle ftsZ genes of their wolbachiae. Our results indicate that O. lupi separated from other Onchocerca spp. early in evolution. This is in line with the previous morphological analysis demonstrating that O. lupi is an atypical Onchocerca species showing both primitive and evolved characters. The phylogenetic trees generated for the COI sequences of filariae and the wsp and ftsZ sequences of their wolbachiae were congruent with each other, which supports the hypothesis that nematodes and their Wolbachia endobacteria share a long co-evolutionary history.}, }
@article {pmid12200484, year = {2002}, author = {Palacios, C and Wernegreen, JJ}, title = {A strong effect of AT mutational bias on amino acid usage in Buchnera is mitigated at high-expression genes.}, journal = {Molecular biology and evolution}, volume = {19}, number = {9}, pages = {1575-1584}, doi = {10.1093/oxfordjournals.molbev.a004219}, pmid = {12200484}, issn = {0737-4038}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Adenine/*metabolism ; Amino Acids/*genetics ; Bacterial Proteins/chemistry/genetics ; Base Composition ; Base Sequence ; Buchnera/*genetics ; Codon/genetics ; Escherichia coli/genetics ; *Gene Expression Regulation, Bacterial ; Genes, Bacterial/*genetics ; Genetic Variation ; Hydrophobic and Hydrophilic Interactions ; Multivariate Analysis ; Point Mutation/*genetics ; Thymine/*metabolism ; }, abstract = {The advent of full genome sequences provides exceptionally rich data sets to explore molecular and evolutionary mechanisms that shape divergence among and within genomes. In this study, we use multivariate analysis to determine the processes driving genome-wide patterns of amino usage in the obligate endosymbiont Buchnera and its close free-living relative Escherichia coli. In the AT-rich Buchnera genome, the primary source of variation in amino acid usage differentiates high- and low-expression genes. Amino acids of high-expression Buchnera genes are generally less aromatic and use relatively GC-rich codons, suggesting that selection against aromatic amino acids and against amino acids with AT-rich codons is stronger in high-expression genes. Selection to maintain hydrophobic amino acids in integral membrane proteins is a primary factor driving protein evolution in E. coli but is a secondary factor in Buchnera. In E. coli, gene expression is a secondary force driving amino acid usage, and a correlation with tRNA abundance suggests that translational selection contributes to this effect. Although this and previous studies demonstrate that AT mutational bias and genetic drift influence amino acid usage in Buchnera, this genome-wide analysis argues that selection is sufficient to affect the amino acid content of proteins with different expression and hydropathy levels.}, }
@article {pmid12200470, year = {2002}, author = {Bailly, X and Jollivet, D and Vanin, S and Deutsch, J and Zal, F and Lallier, F and Toulmond, A}, title = {Evolution of the sulfide-binding function within the globin multigenic family of the deep-sea hydrothermal vent tubeworm Riftia pachyptila.}, journal = {Molecular biology and evolution}, volume = {19}, number = {9}, pages = {1421-1433}, doi = {10.1093/oxfordjournals.molbev.a004205}, pmid = {12200470}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Animals ; Cysteine/metabolism ; *Evolution, Molecular ; Globins/*genetics/*metabolism ; Hydrogen Sulfide/*metabolism ; Likelihood Functions ; Molecular Sequence Data ; Multigene Family/*genetics ; Mutation, Missense/genetics ; Phylogeny ; Polychaeta/*genetics/*metabolism ; RNA, Messenger/genetics/metabolism ; *Seawater ; Sequence Homology, Amino Acid ; Time Factors ; }, abstract = {The giant extracellular hexagonal bilayer hemoglobin (HBL-Hb) of the deep-sea hydrothermal vent tube worm Riftia pachyptila is able to transport simultaneously O(2) and H(2)S in the blood from the gills to a specific organ: the trophosome that harbors sulfide-oxidizing endosymbionts. This vascular HBL-Hb is made of 144 globins from which four globin types (A1, A2, B1, and B2) coevolve. The H(2)S is bound at a specific location (not on the heme site) onto two of these globin types. In order to understand how such a function emerged and evolved in vestimentiferans and other related annelids, six partial cDNAs corresponding to the six globins known to compose the multigenic family of R. pachyptila have been identified and sequenced. These partial sequences (ca. 120 amino acids, i.e., 80% of the entire protein) were used to reconstruct molecular phylogenies in order to trace duplication events that have led to the family organization of these globins and to locate the position of the free cysteine residues known to bind H(2)S. From these sequences, only two free cysteine residues have been found to occur, at positions Cys + 1 (i.e., 1 a.a. from the well-conserved distal histidine) and Cys + 11 (i.e., 11 a.a. from the same histidine) in globins B2 and A2, respectively. These two positions are well conserved in annelids, vestimentiferans, and pogonophorans, which live in sulfidic environments. The structural comparison of the hydrophobic environment that surrounds these cysteine residues (the sulfide-binding domain) using hydrophobic cluster analysis plots, together with the cysteine positions in paralogous strains, suggests that the sulfide-binding function might have emerged before the annelid radiation in order to detoxify this toxic compound. Moreover, globin evolutionary rates are highly different between paralogous strains. This suggests that either the two globin subfamilies involved in the sulfide-binding function (A2 and B2) have evolved under strong directional selective constraints (negative selection) and that the two other globins (A1 and B1) have accumulated more substitutions through positive selection or have evolved neutrally after a relaxation of selection pressures. A likely scenario on the evolution of this multigenic family is proposed and discussed from this data set.}, }
@article {pmid12200264, year = {2002}, author = {Sauer, C and Dudaczek, D and Hölldobler, B and Gross, R}, title = {Tissue localization of the endosymbiotic bacterium "Candidatus Blochmannia floridanus" in adults and larvae of the carpenter ant Camponotus floridanus.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {9}, pages = {4187-4193}, pmid = {12200264}, issn = {0099-2240}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Ants/*microbiology ; Female ; Larva/growth &amp; development/microbiology ; Male ; Proteobacteria/drug effects/*metabolism ; *Symbiosis ; }, abstract = {The distribution of endosymbiotic bacteria in different tissues of queens, males, and workers of the carpenter ant Camponotus floridanus was investigated by light and electron microscopy and by in situ hybridization. A large number of bacteria could be detected in bacteriocytes within the midguts of workers, young virgin queens, and males. Large amounts of bacteria were also found in the oocytes of workers and queens. In contrast, bacteria were not present in oocyte-associated cells or in the spermathecae of mature queens, although occasionally a small number of bacteria could be detected in the testis follicles of males. Interestingly, the number of bacteriocytes in mature queens was strongly reduced and the bacteriocytes contained only very few or no bacteria at all, although the endosymbionts were present in huge amounts in the ovaries of the same animals. During embryogenesis of the deposited egg, the bacteria were concentrated in a ring of endodermal tissue destined to become the midgut in later developmental stages. However, during larval development, bacteria could also be detected in other tissues although to a lesser extent. Only in the last-instar larvae were bacteria found exclusively in the midgut tissue within typical bacteriocytes. Tetracycline and rifampin efficiently cleansed C. floridanus workers of their symbionts and the bacteriocytes of these animals still remained empty several months after treatment had ceased. Despite the lack of their endosymbionts, these adult animals were able to survive without any obvious negative effect under normal cultivation conditions.}, }
@article {pmid12192407, year = {2002}, author = {Williams, BA and Hirt, RP and Lucocq, JM and Embley, TM}, title = {A mitochondrial remnant in the microsporidian Trachipleistophora hominis.}, journal = {Nature}, volume = {418}, number = {6900}, pages = {865-869}, doi = {10.1038/nature00949}, pmid = {12192407}, issn = {0028-0836}, mesh = {Amino Acid Sequence ; Animals ; Blotting, Western ; Cell Line ; Cloning, Molecular ; Endocytosis ; Eukaryotic Cells/cytology/metabolism/ultrastructure ; Fluorescent Antibody Technique ; Fungi/cytology/genetics/metabolism/ultrastructure ; HSP70 Heat-Shock Proteins/*analysis/chemistry/genetics/immunology ; Humans ; Kidney/parasitology ; Microscopy, Electron ; Microscopy, Immunoelectron ; Microsporidia/*chemistry/*cytology/genetics/ultrastructure ; Mitochondria/*chemistry/genetics/ultrastructure ; Mitochondrial Proteins/analysis/chemistry/genetics/immunology ; Models, Biological ; Molecular Sequence Data ; *Phylogeny ; Rabbits ; Symbiosis ; }, abstract = {Microsporidia are obligate intracellular parasites of several eukaryotes. They have a highly complex and unique infection apparatus but otherwise appear structurally simple. Microsporidia are thought to lack typical eukaryotic organelles, such as mitochondria and peroxisomes. This has been interpreted as support for the hypothesis that these peculiar eukaryotes diverged before the mitochondrial endosymbiosis, which would make them one of the earliest offshoots in eukaryotic evolution. But microsporidial nuclear genes that encode orthologues of typical mitochondrial heatshock Hsp70 proteins have been detected, which provides evidence for secondary loss of the organelle or endosymbiont. In addition, gene trees and more sophisticated phylogenetic analyses have recovered microsporidia as the relatives of fungi, rather than as basal eukaryotes. Here we show that a highly specific antibody raised against a Trachipleistophora hominis Hsp70 protein detects the presence, under light and electron microscopy, of numerous tiny (approximately 50 x 90 nm) organelles with double membranes in this human microsporidial parasite. The finding of relictual mitochondria in microsporidia provides further evidence of the reluctance of eukaryotes to lose the mitochondrial organelle, even when its canonical function of aerobic respiration has been apparently lost.}, }
@article {pmid12188042, year = {2002}, author = {Frank, AC and Amiri, H and Andersson, SG}, title = {Genome deterioration: loss of repeated sequences and accumulation of junk DNA.}, journal = {Genetica}, volume = {115}, number = {1}, pages = {1-12}, doi = {10.1023/a:1016064511533}, pmid = {12188042}, issn = {0016-6707}, mesh = {*DNA, Intergenic ; *Evolution, Molecular ; *Genome, Bacterial ; *Repetitive Sequences, Nucleic Acid ; }, abstract = {A global survey of microbial genomes reveals a correlation between genome size, repeat content and lifestyle. Free-living bacteria have large genomes with a high content of repeated sequences and self-propagating DNA, such as transposons and bacteriophages. In contrast, obligate intracellular bacteria have small genomes with a low content of repeated sequences and no or few genetic parasites. In extreme cases, such as in the 650 kb-genomes of aphid endosymbionts of the genus Buchnera all repeated sequences above 200bp have been eliminated. We speculate that the initial downsizing of the genomes of obligate symbionts and parasites occurred by homologous recombination at repeated genes, leading to the loss of large blocks of DNA as well as to the consumption of repeated sequences. Further sequence elimination in these small genomes seems primarily to result from the accumulation of short deletions within genic sequences. This process may lead to temporary increases in the genomic content of pseudogenes and 'junk' DNA. We discuss causes and long-term consequences of extreme genome size reductions in obligate intracellular bacteria.}, }
@article {pmid12177348, year = {2002}, author = {Wernegreen, JJ and Lazarus, AB and Degnan, PH}, title = {Small genome of Candidatus Blochmannia, the bacterial endosymbiont of Camponotus, implies irreversible specialization to an intracellular lifestyle.}, journal = {Microbiology (Reading, England)}, volume = {148}, number = {Pt 8}, pages = {2551-2556}, doi = {10.1099/00221287-148-8-2551}, pmid = {12177348}, issn = {1350-0872}, support = {R01 GM62626-01/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Ants/classification/enzymology/*microbiology ; DNA, Bacterial/chemistry/genetics ; Electrophoresis, Gel, Pulsed-Field ; Gammaproteobacteria/*genetics/isolation &amp; purification ; Genetic Drift ; *Genome, Bacterial ; Molecular Sequence Data ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Blochmannia (Candidatus Blochmannia gen. nov.) is the primary bacterial endosymbiont of the ant genus CAMPONOTUS: Like other obligate endosymbionts of insects, Blochmannia occurs exclusively within eukaryotic cells and has experienced long-term vertical transmission through host lineages. In this study, PFGE was used to estimate the genome size of Blochmannia as approximately 800 kb, which is significantly smaller than its free-living relatives in the enterobacteria. This small genome implies that Blochmannia has deleted most of the genetic machinery of related free-living bacteria. Due to restricted gene exchange in obligate endosymbionts, the substantial gene loss in Blochmannia and other insect mutualists may reflect irreversible specialization to a host cellular environment.}, }
@article {pmid12176308, year = {2002}, author = {Goldberg, WM}, title = {Gastrodermal structure and feeding responses in the scleractinian Mycetophyllia reesi, a coral with novel digestive filaments.}, journal = {Tissue &amp; cell}, volume = {34}, number = {4}, pages = {246-261}, doi = {10.1016/s0040-8166(02)00008-3}, pmid = {12176308}, issn = {0040-8166}, mesh = {Animal Structures/metabolism/ultrastructure ; Animals ; Anthozoa/*physiology/*ultrastructure ; Cytoskeleton/metabolism/ultrastructure ; Digestive System/*metabolism/*ultrastructure ; Epithelial Cells/*metabolism/*ultrastructure ; Feeding Behavior/*physiology ; Microscopy, Electron ; Microscopy, Electron, Scanning ; }, abstract = {Mycetophyllia reesi Wells is a colonial scleractinian coral whose outer surface consists of a series of oral-pharyngeal openings that lack tentacles. The polyps also lack a column and cannot protrude from the colonial surface. Correspondingly, there is no central digestive cavity. Instead, the pharynx is directly connected to a series of radially arranged mesenterial ducts lying parallel to the skeleton. The ducts, composed primarily of ciliated cells with small mucus inclusions and large, compartmentalized mucocytes, house filaments that protrude through the oral apertures during feeding. The filaments may or may not be directly connected with or originate from the mesenterial ducts and are histologically distinct from them. They are therefore referred to as digestive, rather than mesenterial filaments. In contrast with other scleractinians, the digestive filaments are thin, unequally bilobed stalks with spatulate ends. The cnidoglandular (CG) lobe, the larger of the two, exhibits a distinct cellular zonation. Large mastigophore cnidae and elongated zymogen-like cells are clustered at its distal end. Neither of these cells appear to respond to particulate food material, suggesting that they may be employed in alternative modes of nutrition and/or competition. Behind the distal region, the CG lobe exhibits typical zymogen, mucus, and collar cells as well as numerous atrichous nematocysts. The atrichs and zymogen cells discharge during particulate feeding. Tracts of collar cells with particularly well-defined cilia, elongated rootlets, and mucus inclusions are found at the outer edge of the CG lobe. These cells disgorge their contents during feeding and appear to function in food transport. The smaller lobe of the filament is a muscular sheet containing well-defined fields of circular and longitudinal myofibrils along with associated neurons. Collar cells with lysosome-like inclusions and large, compartmentalized mucocytes are also characteristic of this region. There are no zooxanthellae in the filaments, but these endosymbionts are present as a thin layer in the oral-most portion of the gastrodermis. The cellular zonation and multi-functionality of these digestive filaments suggest another example of a cnidarian structure at the organ level of complexity.}, }
@article {pmid12168259, year = {2002}, author = {Michaux-Charachon, S and Foulongne, V and O'Callaghan, D and Ramuz, M}, title = {[Brucella at the dawn of the third milenium: genomic organization and pathogenesis].}, journal = {Pathologie-biologie}, volume = {50}, number = {6}, pages = {401-412}, doi = {10.1016/s0369-8114(02)00313-9}, pmid = {12168259}, issn = {0369-8114}, mesh = {Animals ; Anti-Bacterial Agents ; Bacterial Vaccines ; Brucella/*genetics/growth &amp; development/*pathogenicity ; Brucellosis/drug therapy/microbiology/prevention &amp; control ; Genome, Bacterial ; Humans ; Zoonoses ; }, abstract = {Bacteria of the genus Brucella, responsible for brucellosis, are pathogenic for animals and occasionally for humans. The cost of this widespread zoonotic infection is still very high for the community. Over the last few years, there have been advances in two main domains. First, the Brucella genome has been shown to be complex, with two circular chromosomes. Second, recent data on the virulence of Brucella suggest common mechanisms shared with plant pathogens and endosymbionts of the alpha-proteobacteria. Understanding virulence will have practical repercussions in the realms of vaccine development and, perhaps, development of new antibiotics. Two complete Brucella genome sequences are now available and will be a gold mine of information to guide future research.}, }
@article {pmid12144012, year = {2002}, author = {Egas, M and Vala, F and Breeuwer, JA}, title = {On the evolution of cytoplasmic incompatibility in haplodiploid species.}, journal = {Evolution; international journal of organic evolution}, volume = {56}, number = {6}, pages = {1101-1109}, doi = {10.1111/j.0014-3820.2002.tb01424.x}, pmid = {12144012}, issn = {0014-3820}, mesh = {Bacterial Infections/genetics ; *Biological Evolution ; Cytoplasm/*physiology ; Female ; *Haploidy ; Humans ; Male ; Species Specificity ; Wolbachia/*genetics/growth &amp; development/pathogenicity ; }, abstract = {The most enigmatic sexual manipulation by Wolbachia endosymbionts is cytoplasmic incompatibility (CI): infected males are reproductively incompatible with uninfected females. In this paper, we extend the theory on population dynamics and evolution of CI, with emphasis on haplodiploid species. First, we focus on the problem of the threshold to invasion of the Wolbachia infection in a population. Simulations of the dynamics of infection in small populations show that it does not suffice to assume invasion by drift alone (or demographic "accident"). We propose several promising alternatives that may facilitate invasion of Wolbachia in uninfected populations: sex-ratio effects, meta population structure, and other fitness-compensating effects. Including sex-ratio effects of Wolbachia allows invasion whenever infected females produce more infected daughters than uninfected females produce uninfected daughters. Several studies on haplodiploid species suggest the presence of such sex-ratio effects. The simple metapopulation model we analyzed predicts that, given that infecteds are better "invaders," uninfecteds must be better "colonizers" to maintain coexistence of infected and uninfected patches. This condition seems more feasible for species that suffer local extinction due to predation (or parasitization) than for species that suffer local extinction due to overexploiting their resource(s). Finally, we analyze the evolution of CI in haplodiploids once a population has been infected. Evolution does not depend on the type of CI (female mortality or male production), but hinges solely on decreasing the fitness cost and/or increasing the transmission efficiency. Our models offer new perspectives for increasing our understanding of the population and evolutionary dynamics of CI.}, }
@article {pmid12132134, year = {2002}, author = {Kager, PA}, title = {[Combatting river blindness by means of chemotherapy directed at the symbiotic Wolbachia bacteria in the causative filariae].}, journal = {Nederlands tijdschrift voor geneeskunde}, volume = {146}, number = {26}, pages = {1212-1215}, pmid = {12132134}, issn = {0028-2162}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Disease Models, Animal ; Doxycycline/pharmacology/*therapeutic use ; *Drosophila Proteins ; Female ; Humans ; Male ; Membrane Glycoproteins/physiology ; Mice ; Onchocerca/microbiology/*physiology ; Onchocerciasis, Ocular/*drug therapy/prevention &amp; control ; Receptors, Cell Surface/physiology ; Symbiosis ; Toll-Like Receptor 4 ; Toll-Like Receptors ; Wolbachia/*drug effects/physiology ; }, abstract = {In a mouse model of river blindness it was demonstrated that Wolbachia bacteria, endosymbionts of filarial nematodes, play an important role in the inflammatory process leading to the disease and that this process depends on Toll-like receptor 4. Wolbachia is found in many arthropods and in all filariae pathogenic for man. Treatment with doxycycline depletes female filariae of Wolbachia and renders them infertile for at least 18 months. Chemotherapy of filarial nematodes should be studied for the reduction and possibly prevention of pathology due to filariae, and for a contribution to control and eradication programmes.}, }
@article {pmid12095241, year = {2002}, author = {Puttaraju, HP and Madhu, M}, title = {Presence of Wolbachia endosymbionts in different silkworm species and races and in their uzi fly parasites.}, journal = {Journal of invertebrate pathology}, volume = {79}, number = {2}, pages = {120-122}, doi = {10.1016/s0022-2011(02)00031-9}, pmid = {12095241}, issn = {0022-2011}, mesh = {Animals ; Bombyx/classification/*microbiology/*parasitology ; Diptera/*microbiology ; *Ectoparasitic Infestations ; *Symbiosis ; Wolbachia/*isolation &amp; purification ; }, }
@article {pmid12089438, year = {2002}, author = {Tamas, I and Klasson, L and Canbäck, B and Näslund, AK and Eriksson, AS and Wernegreen, JJ and Sandström, JP and Moran, NA and Andersson, SG}, title = {50 million years of genomic stasis in endosymbiotic bacteria.}, journal = {Science (New York, N.Y.)}, volume = {296}, number = {5577}, pages = {2376-2379}, doi = {10.1126/science.1071278}, pmid = {12089438}, issn = {1095-9203}, mesh = {Animals ; Aphids/*microbiology/physiology ; Bacterial Proteins/chemistry/genetics ; Biological Evolution ; Buchnera/*genetics/physiology ; DNA, Intergenic ; Diet ; Ecosystem ; Escherichia coli/genetics ; *Evolution, Molecular ; Genes, Bacterial ; Genetic Variation ; *Genome, Bacterial ; Molecular Sequence Data ; Mutation ; Operon ; Pseudogenes ; Recombination, Genetic ; Repetitive Sequences, Nucleic Acid ; Salmonella typhimurium/genetics ; Species Specificity ; *Symbiosis ; }, abstract = {Comparison of two fully sequenced genomes of Buchnera aphidicola, the obligate endosymbionts of aphids, reveals the most extreme genome stability to date: no chromosome rearrangements or gene acquisitions have occurred in the past 50 to 70 million years, despite substantial sequence evolution and the inactivation and loss of individual genes. In contrast, the genomes of their closest free-living relatives, Escherichia coli and Salmonella spp., are more than 2000-fold more labile in content and gene order. The genomic stasis of B. aphidicola, likely attributable to the loss of phages, repeated sequences, and recA, indicates that B. aphidicola is no longer a source of ecological innovation for its hosts.}, }
@article {pmid12089328, year = {2002}, author = {Ishida, K and Green, BR}, title = {Second- and third-hand chloroplasts in dinoflagellates: phylogeny of oxygen-evolving enhancer 1 (PsbO) protein reveals replacement of a nuclear-encoded plastid gene by that of a haptophyte tertiary endosymbiont.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {99}, number = {14}, pages = {9294-9299}, pmid = {12089328}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Chloroplasts/*genetics ; DNA, Protozoan/genetics ; Dinoflagellida/classification/*genetics/*metabolism ; Eukaryota/genetics ; Genes, Protozoan ; Models, Genetic ; Molecular Sequence Data ; Oxygen/metabolism ; Photosynthetic Reaction Center Complex Proteins/*genetics ; *Photosystem II Protein Complex ; Phylogeny ; Plastids/genetics ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; }, abstract = {Several dinoflagellate species have plastids that more closely resemble those of an unrelated algal group, the haptophytes, suggesting these plastids have been obtained by tertiary endosymbiosis. Because both groups are photosynthetic, all of the genes for nuclear-encoded plastid proteins might be supplied by the dinoflagellate host or some of them might have been replaced by haptophyte genes. Sequences of the conserved nuclear psbO gene were obtained from the haptophyte Isochrysis galbana, the peridinin-containing dinoflagellate Heterocapsa triquetra, and the 19'hexanoyloxy-fucoxanthin-containing dinoflagellate Karenia brevis. Phylogenetic analysis of the oxygen-evolving-enhancer (PsbO) proteins confirmed that in K. brevis the original peridinin-type plastid was replaced by that of a haptophyte, an alga which had previously acquired a red algal chloroplast by secondary endosymbiosis. It showed clearly that during this tertiary symbiogenesis the original psbO gene in the dinoflagellate nucleus was replaced by a psbO gene from the haptophyte nucleus. The phylogenetic analysis also confirmed that the origin of the peridinin-type dinoflagellate plastid was indeed a red alga.}, }
@article {pmid12088995, year = {2002}, author = {Baumann, L and Thao, ML and Hess, JM and Johnson, MW and Baumann, P}, title = {The genetic properties of the primary endosymbionts of mealybugs differ from those of other endosymbionts of plant sap-sucking insects.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {7}, pages = {3198-3205}, pmid = {12088995}, issn = {0099-2240}, mesh = {Amino Acids/chemistry ; Animals ; Codon ; Conserved Sequence ; DNA, Bacterial/analysis ; DNA, Intergenic ; GC Rich Sequence ; Gene Duplication ; Hemiptera/*microbiology/physiology ; Molecular Sequence Data ; Operon ; Plants/parasitology ; Proteobacteria/classification/*physiology ; RNA, Ribosomal/genetics ; Symbiosis/*physiology ; }, abstract = {Mealybugs (Hemiptera, Coccoidea, Pseudococcidae), like aphids and psyllids, are plant sap-sucking insects that have an obligate association with prokaryotic endosymbionts that are acquired through vertical, maternal transmission. We sequenced two fragments of the genome of Tremblaya princeps, the endosymbiont of mealybugs, which is a member of the beta subdivision of the Proteobacteria. Each of the fragments (35 and 30 kb) contains a copy of 16S-23S-5S rRNA genes. A total of 37 open reading frames were detected, which corresponded to putative rRNA proteins, chaperones, and enzymes of branched-chain amino acid biosynthesis, DNA replication, protein translation, and RNA synthesis. The genome of T. princeps has a number of properties that distinguish it from the genomes of Buchnera aphidicola and Carsonella ruddii, the endosymbionts of aphids and psyllids, respectively. Among these properties are a high G+C content (57.1 mol%), the same G+C content in intergenic spaces and structural genes, and similar G+C contents of the genes encoding highly and poorly conserved proteins. The high G+C content has a substantial effect on protein composition; about one-third of the residues consist of four amino acids with high-G+C-content codons. Sequence analysis of DNA fragments containing the rRNA operon and adjacent regions from endosymbionts of several mealybug species suggested that there was a single duplication of the rRNA operon and the adjacent genes in an ancestor of the present T. princeps. Subsequently, in one mealybug lineage rpS15, one of the duplicated genes, was retained, while in another lineage it decayed. These results extend the diversity of the types of endosymbiotic associations found in plant sap-sucking insects.}, }
@article {pmid12088994, year = {2002}, author = {Thao, ML and Gullan, PJ and Baumann, P}, title = {Secondary (gamma-Proteobacteria) endosymbionts infect the primary (beta-Proteobacteria) endosymbionts of mealybugs multiple times and coevolve with their hosts.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {7}, pages = {3190-3197}, pmid = {12088994}, issn = {0099-2240}, mesh = {Animals ; Betaproteobacteria/classification/genetics/*physiology ; Gammaproteobacteria/classification/genetics/*physiology ; Hemiptera/*microbiology/physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Symbiosis/*physiology ; Time Factors ; }, abstract = {Mealybugs (Hemiptera, Coccoidea, Pseudococcidae) are plant sap-sucking insects that have within their body cavities specialized cells containing prokaryotic primary endosymbionts (P-endosymbionts). The P-endosymbionts have the unusual property of containing within their cytoplasm prokaryotic secondary endosymbionts (S-endosymbionts) [C. D. von Dohlen, S. Kohler, S. T. Alsop, and W. R. McManus, Nature (London) 412:433-436, 2001]. Four-kilobase fragments containing 16S-23S ribosomal DNA (rDNA) were obtained from the P-endosymbionts of 22 mealybug species and the S-endosymbionts of 12 representative species. Phylogenetic analyses of the P-endosymbionts indicated that they have a monophyletic origin and are members of the beta-subdivision of the Proteobacteria; these organisms were subdivided into five different clusters. The S-endosymbionts were members of the gamma-subdivision of the Proteobacteria and were grouped into clusters similar to those observed with the P-endosymbionts. The S-endosymbiont clusters were distinct from each other and from other insect-associated bacteria. The similarity of the clusters formed by the P- and S-endosymbionts suggests that the P-endosymbionts of mealybugs were infected multiple times with different precursors of the S-endosymbionts and once the association was established, the P- and S-endosymbionts were transmitted together. The lineage consisting of the P-endosymbionts of mealybugs was given the designation "Candidatus Tremblaya" gen. nov., with a single species, "Candidatus Tremblaya princeps" sp. nov. The results of phylogenetic analyses of mitochondrial DNA fragments encoding cytochrome oxidase subunits I and II from four representative mealybug species were in agreement with the results of 16S-23S rDNA analyses, suggesting that relationships among strains of "Candidatus T. princeps" are useful in inferring the phylogeny of their mealybug hosts.}, }
@article {pmid12087426, year = {2002}, author = {Mira, A and Moran, NA}, title = {Estimating population size and transmission bottlenecks in maternally transmitted endosymbiotic bacteria.}, journal = {Microbial ecology}, volume = {44}, number = {2}, pages = {137-143}, doi = {10.1007/s00248-002-0012-9}, pmid = {12087426}, issn = {0095-3628}, mesh = {Animals ; Aphids/*microbiology ; *Buchnera ; Eggs/microbiology ; Embryo, Nonmammalian/microbiology ; *Infectious Disease Transmission, Vertical ; Larva ; Microscopy, Electron ; Population Dynamics ; Symbiosis/*physiology ; }, abstract = {Many species of bacterial endosymbionts are acquired by animal hosts before birth, through direct transmission from mothers to eggs or embryos. This vertical transmission imposes a reduction in numbers or "bottleneck," and the size of this bottleneck affects the population structure and evolution of symbiotic lineages. We have estimated the size of the transmission bottleneck in Buchnera, the bacterial symbiont of aphids, using basic light and electron microscopy techniques. By serial-sectioning whole aphid abdomens, their eggs, and embryos, we determined the following parameters: (i) The average size of a Buchnera cell is 2.9 mm in diameter. (ii) The total number of Buchnera in an Acyrthosiphon pisum embryo was around 36700 whereas a first instar nymph contained more than 119000. (iii) The number of symbionts per bacteriocyte was around 800 in an embryo and 3200 in a first instar nymph. (iv) The total number of Buchnera transmitted to each sexual egg ranged from 850 in Nasonovia to 1800 in A. pisum to more than 8000 in Uroleucon ambrosiae. (v) The total number of secondary endosymbionts in A. pisum was 12170 for an embryo and 18360 for a first instar nymph. Secondary symbionts were arranged both extracellularly and in clusters of 2000-8000 bacteria inside bacteriocytes. These numbers are consistent with the few previous estimates of symbiont population sizes based on counts of gene copies.}, }
@article {pmid12082135, year = {2002}, author = {Fares, MA and Barrio, E and Sabater-Muñoz, B and Moya, A}, title = {The evolution of the heat-shock protein GroEL from Buchnera, the primary endosymbiont of aphids, is governed by positive selection.}, journal = {Molecular biology and evolution}, volume = {19}, number = {7}, pages = {1162-1170}, doi = {10.1093/oxfordjournals.molbev.a004174}, pmid = {12082135}, issn = {0737-4038}, mesh = {Amino Acid Substitution ; Animals ; Aphids/*microbiology ; Buchnera/*metabolism ; Cell Lineage ; Chaperonin 60/*genetics/metabolism ; DNA Primers/chemistry ; Escherichia coli/genetics/*metabolism ; *Evolution, Molecular ; In Vitro Techniques ; Operon/genetics ; Phylogeny ; Polymerase Chain Reaction ; *Selection, Genetic ; Symbiosis/*physiology ; }, abstract = {The heat-shock protein GroEL is a double-ring-structured chaperonin that assists the folding of many newly synthesized proteins in Escherichia coli and the refolding in vitro, with the cochaperonin GroES, of conformationally damaged proteins. This protein is constitutively overexpressed in the primary symbiotic bacteria of many insects, constituting approximately 10% of the total protein in Buchnera, the primary endosymbiont of aphids. In the present study, we perform a maximum likelihood (ML) analysis to unveil the selective constraints in GroEL. In addition, we apply a new statistical approach to determine the patterns of evolution in this highly interesting protein. The main conclusion derived from our analysis is that GroEL has suffered an accelerated rate of amino acid substitution upon the symbiotic integration of Buchnera into the aphids. It is most interesting that the ML analysis of codon substitutions in the different branches of the phylogenetic tree strongly supports the action of positive selection in the different lineages of BUCHNERA: Additionally, the new sliding window analysis of the complete groEL sequence reveals different regions of the molecule under the action of positive selection, mainly located in the apical domain, that are important for both peptide and GroES binding.}, }
@article {pmid12079666, year = {2002}, author = {Berticat, C and Rousset, F and Raymond, M and Berthomieu, A and Weill, M}, title = {High Wolbachia density in insecticide-resistant mosquitoes.}, journal = {Proceedings. Biological sciences}, volume = {269}, number = {1498}, pages = {1413-1416}, pmid = {12079666}, issn = {0962-8452}, mesh = {Animals ; Colony Count, Microbial ; Culex/*drug effects/genetics/*microbiology ; Genes, Insect/genetics ; *Insecticide Resistance/genetics ; Insecticides/*pharmacology ; Polymerase Chain Reaction ; Symbiosis ; Wolbachia/genetics/growth &amp; development/*isolation &amp; purification ; }, abstract = {Wolbachia symbionts are responsible for various alterations in host reproduction. The effects of the host genome on endosymbiont levels have often been suggested, but rarely described. Here, we show that Wolbachia density is strongly modified by the presence of insecticide-resistant genes in the common house mosquito, Culex pipiens. The Wolbachia density was estimated using a real-time quantitative PCR assay. Strains harbouring different genes conferring resistance were more infected than a susceptible strain with the same genetic background. We show that this interaction also operates in natural populations. We propose that mosquitoes may control Wolbachia density less efficiently when they carry an insecticide-resistant gene, i.e. when they suffer from a physiological resistance cost.}, }
@article {pmid12061452, year = {2002}, author = {Kurtti, TJ and Palmer, AT and Oliver, JH}, title = {Rickettsiella-like bacteria in Ixodes woodi (Acari: Ixodidae).}, journal = {Journal of medical entomology}, volume = {39}, number = {3}, pages = {534-540}, doi = {10.1603/0022-2585-39.3.534}, pmid = {12061452}, issn = {0022-2585}, support = {R37 AI-24899/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Ixodes/*microbiology/ultrastructure ; Mice ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; Rabbits ; Rickettsieae/classification/genetics/*isolation &amp; purification/ultrastructure ; Symbiosis ; }, abstract = {We examined a parthenogenetic strain of the hard tick Ixodes woodi Bishopp for the presence of endosymbiotic bacteria. Electron microscopic examination revealed the ovarian tissues and Malpighian tubules were infected with pleomorphic bacteria. Two basic types were observed: a larger granular cell and a smaller condensed cell. Cloning and sequence analysis of polymerase chain reaction (PCR) amplified 16S rRNA gene yielded a single sequence from bacteria present in I. woodi tissues. Phylogenetic analysis of the nearly complete 16S rDNA indicated that the ticks were infected with an endosymbiont belonging to the gamma subdivision of the Proteobacteria. It clustered with the insect pathogenic species Rickettsiellagrylli (Vago and Martoja 1963) and the animal pathogen Coxiella burnetii (Derrick 1939) Philip 1948. Our results suggest that the I. woodi females harbored a single endosymbiotic bacterium related to selected Rickettsiella species and to C burnetii.}, }
@article {pmid12055314, year = {2002}, author = {Elsaied, H and Kimura, H and Naganuma, T}, title = {Molecular characterization and endosymbiotic localization of the gene encoding D-ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO) form II in the deep-sea vestimentiferan trophosome.}, journal = {Microbiology (Reading, England)}, volume = {148}, number = {Pt 6}, pages = {1947-1957}, doi = {10.1099/00221287-148-6-1947}, pmid = {12055314}, issn = {1350-0872}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/classification/*enzymology/*genetics ; Base Sequence ; In Situ Hybridization ; Molecular Sequence Data ; Phylogeny ; Polychaeta/*microbiology ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Ribulose-Bisphosphate Carboxylase/chemistry/classification/*genetics ; Seawater/*microbiology ; Sensitivity and Specificity ; *Symbiosis ; }, abstract = {To better understand the contribution of micro-organisms to the primary production in the deep-sea gutless tubeworm Lamellibrachia sp., the 16S-rDNA-based phylogenetic data would be complemented by knowledge of the genes that encode the enzymes relevant to chemoautotrophic carbon fixation, such as D-ribulose 1,5-bisphosphate carboxylase-oxygenase (RuBisCO; EC 4.1.1.39). To phylogenetically characterize the autotrophic endosymbiosis within the trophosome of the tubeworm Lamellibrachia sp., bulk trophosomal DNA was extracted and analysed based on the 16S-rRNA- and RuBisCO-encoding genes. The 16S-rRNA- and RuBisCO-encoding genes were amplified by PCR, cloned and sequenced. For the 16S rDNA, a total of 50 clones were randomly selected and analysed directly by sequencing. Only one operational taxonomic unit resulted from the 16S rDNA sequence analysis. This may indicate the occurrence of one endosymbiotic bacterial species within the trophosome of the Lamellibrachia sp. used in this study. Phylogenetic analysis of the 16S rDNA showed that the Lamellibrachia sp. endosymbiont was closely related to the genus Rhodobacter, a member of the alpha-Protebacteria. For the RuBisCO genes, only the form II gene (cbbM) was amplified by PCR. A total of 50 cbbM clones were sequenced, and these were grouped into two operational RuBisCO units (ORUs) based on their deduced amino acid sequences. The cbbM ORUs showed high amino acid identities with those recorded from the ambient sediment bacteria. To confirm the results of sequence analysis, the localization of the symbiont-specific 16S rRNA and cbbM sequences in the Lamellibrachia sp. trophosome was visualized by in situ hybridization (ISH), using specific probes. Two types of cells, coccoid and filamentous, were observed at the peripheries of the trophosome lobules. Both the symbiont-specific 16S rDNA and cbbM probes hybridized at the same sites coincident with the location of the coccoid cells, whereas the filamentous cells showed no cbbM-specific signals. The RuBisCO form I gene (cbbL) was neither amplified by PCR nor detected by ISH. This is the first demonstration of chemoautotrophic symbiosis in the deep-sea gutless tubeworm, based on sequence data and in situ localization of both the 16S-rRNA- and RuBisCO-encoding genes.}, }
@article {pmid12051563, year = {2001}, author = {Dolan, MF}, title = {Speciation of termite gut protists: the role of bacterial symbionts.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {4}, number = {4}, pages = {203-208}, doi = {10.1007/s10123-001-0038-8}, pmid = {12051563}, issn = {1139-6709}, mesh = {Animals ; *Bacterial Physiological Phenomena ; Digestive System/parasitology ; Eukaryota/*microbiology ; Isoptera/*parasitology ; *Symbiosis ; }, abstract = {At least 12 termite gut protists have been named because of their bacterial symbionts. Dozens more species are diagnosed by epi- and endosymbionts and more still have regular bacterial associations referred to in their species description. Molecular systematic studies have begun to identify these bacteria, but the ecological relations with their protist bionts are still unknown. Recent findings of acetogenic spirochetes in termite guts may explain the peculiar arrangement of spirochetes on some of these protists. Other bacteria function as motility or chemotactic symbionts of these protists. The size and shape of the parabasal body, a Golgi complex, are morphological characters of the Parabasalia (trichomonads, hypermastigids) that may be influenced by regular, heritable epi- and endosymbiotic bacteria.}, }
@article {pmid12039775, year = {2002}, author = {Vandekerckhove, TT and Coomans, A and Cornelis, K and Baert, P and Gillis, M}, title = {Use of the Verrucomicrobia-specific probe EUB338-III and fluorescent in situ hybridization for detection of "Candidatus Xiphinematobacter" cells in nematode hosts.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {6}, pages = {3121-3125}, pmid = {12039775}, issn = {0099-2240}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; DNA, Bacterial/*analysis ; Fluorescent Dyes/metabolism ; In Situ Hybridization, Fluorescence ; Indoles/metabolism ; Nematoda/*microbiology ; Oligonucleotide Probes/metabolism ; RNA, Ribosomal, 16S/analysis/genetics ; }, abstract = {Fluorescent in situ hybridization with a 16S rRNA probe specific for Verrucomicrobia was used to (i) confirm the division-level identity of and (ii) study the behavior of the obligate intracellular verrucomicrobium "Candidatus Xiphinematobacter" in its nematode hosts. Endosymbionts in the egg move to the pole where the gut primordium arises; hence, they populate the intestinal epithelia of juvenile worms. During the host's molt to adult female, the endosymbionts concentrate around the developing ovaries to occupy the ovarian wall. Some bacteria are enclosed in the ripening oocytes for vertical transmission. Verrucomicrobia in males stay outside the testes because the tiny spermatozoids are not suitable for transmission of cytoplasmic bacteria.}, }
@article {pmid12039769, year = {2002}, author = {Greub, G and Raoult, D}, title = {Crescent bodies of Parachlamydia acanthamoeba and its life cycle within Acanthamoeba polyphaga: an electron micrograph study.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {6}, pages = {3076-3084}, pmid = {12039769}, issn = {0099-2240}, mesh = {Acanthamoeba/*microbiology/ultrastructure ; Animals ; Chlamydiales/physiology/*ultrastructure ; Life Cycle Stages ; Microscopy, Electron ; }, abstract = {Parachlamydiaceae are endosymbionts of free-living amoeba first identified in 1997. Two developmental stages, elementary and reticulate bodies, were observed; however, their localization and proportions according to culture condition and duration remain unknown. The life cycle of Parachlamydia acanthamoeba within Acanthamoeba polyphaga was studied by transmission electron microscopy of 8-, 36-, and 144-h coculture. Morphometry and quantification were performed using SAMBA software. The elementary body, the predominant stage within the amoebae, was located mainly within their vacuoles. The multiplication of Parachlamydia bacteria by binary fission of reticulate bodies was independently associated with culture in PYG broth (odds ratio [OR] = 4.4; 95% confidence interval [CI], 1.55 to 12.46) and with the presence of reticulate bodies within the amoebae (OR = 2.10; 95% CI, 1.53 to 2.89). A third developmental stage was observed, the crescent body. Its presence outside and inside the amoebae was associated mainly with prolonged incubation time (OR = 3.98; 95% CI, 1.49 to 10.68, and OR = 5.98; 95% CI, 1.75 to 20.4, respectively). Elementary and crescent bodies were released into the extracellular medium within vesicles or after amoebal lysis. For both, phagocytosis was their mode of entry. This electron micrograph study revealed another infective developmental stage, the crescent body, and provided quantitative analysis of the life cycle of P. acanthamoeba within A. polyphaga.}, }
@article {pmid12035091, year = {2000}, author = {Kusch, J and Stremmel, M and Breiner, HW and Adams, V and Schweikert, M and Schmidt, HJ}, title = {The Toxic Symbiont Caedibacter caryophila in the Cytoplasm of Paramecium novaurelia.}, journal = {Microbial ecology}, volume = {40}, number = {4}, pages = {330-335}, pmid = {12035091}, issn = {1432-184X}, abstract = {Endosymbiotic bacteria were observed to inhabit the cytoplasm of the freshwater ciliate Paramecium novaurelia. Transmission electron microscopy and toxicity tests with sensitive paramecia showed that the endosymbionts belong to the genus Caedibacter. The bacteria conferred a killer trait to their host paramecia. The production of a proteinaceous inclusion body ("R-body") in the bacterial cell makes them toxic to other paramecia after they become enclosed in food vacuoles. R-bodies of Caedibacter sp were associated with phages, which are known in most other Caedibacter species to code for the R-body proteins. The killer-effect of P. novaurelia on sensitive P. caudatum strains was of the "paralysis" type, which is a characteristic of the symbiont species Caedibacter caryophila. Until now C. caryophila was known to inhabit the macronucleus of Paramecium caudatum only. Sequencing of the 16S rRNA-gene proved that Caedibacter sp from the cytoplasm of P. novaurelia belongs to the species C. caryophila as well. The rDNA-sequence of 1695 bp length differed in a total of only 1 bp from the corresponding gene in C. caryophila from the macronucleus of P. caudatum. The results indicate that the infection of specific host cell compartments may depend on host genes, but not on different traits of the infecting symbiont species. The occurrence of killer and sensitive paramecia strains together in one pond is discussed with respect to the competitive advantage of the killer trait.}, }
@article {pmid12029466, year = {2002}, author = {Kuroiwa, H and Mori, T and Takahara, M and Miyagishima, SY and Kuroiwa, T}, title = {Chloroplast division machinery as revealed by immunofluorescence and electron microscopy.}, journal = {Planta}, volume = {215}, number = {2}, pages = {185-190}, doi = {10.1007/s00425-002-0734-4}, pmid = {12029466}, issn = {0032-0935}, mesh = {Antibodies/immunology ; Arabidopsis/metabolism ; Arabidopsis Proteins ; Chloroplasts/*metabolism/ultrastructure ; Immunoblotting ; Lolium/metabolism ; Magnoliopsida/*metabolism ; Microscopy, Fluorescence/*methods ; Microscopy, Immunoelectron/*methods ; Plant Proteins/immunology/metabolism ; Seeds/metabolism ; }, abstract = {The division of chloroplasts (plastids) is critical for the viability of photosynthetic eukaryotes. Previously we reported on the chloroplast division apparatus, which consists of inner and outer double or triple rings (PD rings). Chloroplasts are assumed to arise from bacterial endosymbionts, while bacterial division is instigated by a bacterial cytokinesis Z-ring protein (FtsZ). Here we present immunofluorescence and electron-microscopic evidence of chloroplast division via complex machinery involving the FtsZ and PD rings in the higher plant Pelargonium zonale Ait. Prior to invagination, the FtsZ protein was attached to a ring at the stromal division site. Following formation of the FtsZ ring, the inner stromal and outer cytosolic PD rings appeared, signifying the initiation of invagination. The FtsZ ring and the PD rings were found at the leading edge of chloroplast constriction throughout division. During chloroplast division, neither the FtsZ nor the inner rings changed width, but the volume of the outer ring gradually increased. We suggest that the FtsZ ring determines the division region, after which the inner and outer PD rings are formed as a lining for the FtsZ ring. With the outer ring providing the motivating force, the FtsZ and inner PD rings ultimately decompose to their base components.}, }
@article {pmid12029363, year = {2002}, author = {Minerdi, D and Fani, R and Bonfante, P}, title = {Identification and evolutionary analysis of putative cytoplasmic mcpA-like protein in a bacterial strain living in symbiosis with a mycorrhizal fungus.}, journal = {Journal of molecular evolution}, volume = {54}, number = {6}, pages = {815-824}, doi = {10.1007/s00239-001-0086-x}, pmid = {12029363}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Bacterial Proteins/chemistry/*genetics/isolation &amp; purification ; Burkholderia/*genetics/physiology ; *Evolution, Molecular ; *Fungi/physiology ; Genes, Bacterial ; Membrane Proteins/*chemistry ; Methyl-Accepting Chemotaxis Proteins ; Molecular Sequence Data ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Homology, Amino Acid ; Spores, Fungal ; Symbiosis ; }, abstract = {In this paper we report the identification and characterization of a DNA region containing putative mcpA-like gene coding for a Methyl Accepting Chemotaxis Protein (MCP) and belonging to a Burkholderia endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. A genomic library of total DNA extracted from the fungal spores, representative of the bacterial genome, was used to investigate the prokaryotic genome. PCR experiments with primers designed on the Burkholderia mcpA-like gene and Southern blot analysis demonstrate that they actually belong to the genome of G. margarita endosymbiont. The expression of the mcpA-like gene in the fungal spores was demonstrated by RT-PCR experiments. The detailed comparative analysis of the bacterial MCPs available in databases allowed to draw a possible evolutionary pathway leading to the present-day mcpA genes. Accordingly, the ancestor of the mcpA-like genes was the result of a domain shuffling event involving two ancestral mini-genes encoding a PAS-PAC and a MA domains, respectively, followed by the elongation of the PAS-PAC moiety. The following evolutionary divergence involved not only point mutations, but also larger rearrangements (insertions and deletions) at the 3' end of the gene.}, }
@article {pmid12019272, year = {2002}, author = {Basu, SS and Karbarz, MJ and Raetz, CR}, title = {Expression cloning and characterization of the C28 acyltransferase of lipid A biosynthesis in Rhizobium leguminosarum.}, journal = {The Journal of biological chemistry}, volume = {277}, number = {32}, pages = {28959-28971}, pmid = {12019272}, issn = {0021-9258}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; R37 GM051796-06/GM/NIGMS NIH HHS/United States ; R37-GM-51796/GM/NIGMS NIH HHS/United States ; GM-08558/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Motifs ; Amino Acid Sequence ; Carbohydrate Sequence ; Cell Division ; Cell-Free System ; Chromatography, High Pressure Liquid ; Cloning, Molecular ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli/genetics/metabolism ; Gene Library ; Hydrolysis ; Lipid A/*chemistry ; Mass Spectrometry ; Models, Biological ; Models, Chemical ; Models, Genetic ; Molecular Sequence Data ; Plasmids/metabolism ; Protein Binding ; Rhizobium leguminosarum/genetics/*metabolism ; Sequence Homology, Amino Acid ; Sinorhizobium meliloti/metabolism ; Time Factors ; }, abstract = {An unusual feature of lipid A from plant endosymbionts of the Rhizobiaceae family is the presence of a 27-hydroxyoctacosanoic acid (C28) moiety. An enzyme that incorporates this acyl chain is present in extracts of Rhizobium leguminosarum, Rhizobium etli, and Sinorhizobium meliloti but not Escherichia coli. The enzyme transfers 27-hydroxyoctacosanate from a specialized acyl carrier protein (AcpXL) to the precursor Kdo2 ((3-deoxy-d-manno-octulosonic acid)2)-lipid IV(A). We now report the identification of five hybrid cosmids that direct the overexpression of this activity by screening approximately 4000 lysates of individual colonies of an R. leguminosarum 3841 genomic DNA library in the host strain S. meliloti 1021. In these heterologous constructs, both the C28 acyltransferase and C28-AcpXL are overproduced. Sequencing of a 9-kb insert from cosmid pSSB-1, which is also present in the other cosmids, shows that acpXL and the lipid A acyltransferase gene (lpxXL) are close to each other but not contiguous. Nine other open reading frames around lpxXL were also sequenced. Four of them encode orthologues of fatty acid and/or polyketide biosynthetic enzymes. AcpXL purified from S. meliloti expressing pSSB-1 is fully acylated, mainly with 27-hydroxyoctacosanoate. Expression of lpxXL in E. coli behind a T7 promoter results in overproduction in vitro of the expected R. leguminosarum acyltransferase, which is C28-AcpXL-dependent and utilizes (3-deoxy-d-manno-octulosonic acid)2-lipid IV(A) as the acceptor. These findings confirm that lpxXL is the structural gene for the C28 acyltransferase. LpxXL is distantly related to the lauroyltransferase (LpxL) of E. coli lipid A biosynthesis, but highly significant LpxXL orthologues are present in Agrobacterium tumefaciens, Brucella melitensis, and all sequenced strains of Rhizobium, consistent with the occurrence of long secondary acyl chains in the lipid A molecules of these organisms.}, }
@article {pmid12010127, year = {2002}, author = {López-García, P and Gaill, F and Moreira, D}, title = {Wide bacterial diversity associated with tubes of the vent worm Riftia pachyptila.}, journal = {Environmental microbiology}, volume = {4}, number = {4}, pages = {204-215}, doi = {10.1046/j.1462-2920.2002.00286.x}, pmid = {12010127}, issn = {1462-2912}, mesh = {Animals ; DNA, Bacterial/analysis ; Eukaryotic Cells/*microbiology ; Marine Biology ; Microscopy, Electron, Scanning ; Molecular Sequence Data ; Phylogeny ; Proteobacteria/classification/genetics/*isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; Water Microbiology ; }, abstract = {We carried out a 16S rDNA-based molecular survey of the prokaryotic diversity associated with the chitin tubes of the giant vent tubeworm Riftia pachyptila (collected at the East Pacific Rise, 9 degrees N and 13 degrees N). Scanning electron microscopy showed dense microbial populations, particularly on the external surface of the middle and upper tube regions, which included very diverse prokaryotic morphotypes. We used archaeal- and bacterial-specific primers for polymerase chain reaction (PCR) amplification, but only bacterial amplicons were obtained. We analysed a total of 87 clones. Most belonged to the epsilon-Proteobacteria, but also to the delta-, alpha- and gamma-Proteobacteria. A broad diversity of phylotypes belonging to other bacterial divisions was detected, including Verrucomicrobia, the Cytophaga-Flavobacterium-Bacteroides group and the candidate division OP8. We also retrieved a sequence, R76-B150, of uncertain phylogenetic affiliation, which could represent a novel candidate division. The sequence of the R. pachyptilagamma-proteobacterial endosymbiont was not detected. The bacterial diversity found suggests that complex metabolic interactions, particularly based on sulphur chemistry, may be occurring in different microniches of the R. pachyptila tubes.}, }
@article {pmid12008915, year = {2002}, author = {Skriwan, C and Fajardo, M and Hägele, S and Horn, M and Wagner, M and Michel, R and Krohne, G and Schleicher, M and Hacker, J and Steinert, M}, title = {Various bacterial pathogens and symbionts infect the amoeba Dictyostelium discoideum.}, journal = {International journal of medical microbiology : IJMM}, volume = {291}, number = {8}, pages = {615-624}, doi = {10.1078/1438-4221-00177}, pmid = {12008915}, issn = {1438-4221}, mesh = {Acanthamoeba/growth &amp; development ; Animals ; Carrier Proteins ; Dictyostelium/*microbiology/ultrastructure ; In Situ Hybridization, Fluorescence ; Legionella pneumophila/genetics/growth &amp; development/*pathogenicity ; Microfilament Proteins/physiology ; Microscopy, Electron ; Mutation ; Mycobacterium avium/growth &amp; development/*pathogenicity ; Protozoan Proteins/physiology ; Pseudomonas aeruginosa/growth &amp; development/*pathogenicity ; RNA, Ribosomal, 16S/genetics ; Salmonella typhi/growth &amp; development/*pathogenicity ; }, abstract = {The haploid soil amoeba Dictyostelium discoideum is a suitable model organism to study host-pathogen interactions with Legionella pneumophila. In this study we show that D. discoideum AX2 is also susceptible to infection with other important human pathogens and obligate intracellular symbionts. Infection assays demonstrated that Legionella-like amoebal pathogens (LLAP K62), Mycobacterium avium and the obligate intracellular endosymbionts of Acanthamoeba sp. strains TUME1, UWE25 and UWC6 were able to multiply within Dictyostelium. Salmonella typhimurium and Pseudomonas aeruginosa also invaded Dictyostelium, however were degraded shortly after uptake. Comitin-minus host cells were more permissive to infections with L. pneumophila and LLAP K62. Furthermore, this mutation significantly delayed the degradation of S. typhimurium. Accompanying electron and fluorescence microscopy of infected AX2 cells revealed that L. pneumophila and M. avium replicate within vacuoles, while LLAP K62, TUME1 and UWE25 were tightly enclosed by membranous structures within the cytoplasm. The beta-proteobacterium UWC6 was found to persist in the cytoplasm. The observed subcellular locations which correspond to the locations within the respective natural hosts suggest that D. discoideum is a representative model system for these pathogens and symbionts.}, }
@article {pmid11999851, year = {2002}, author = {Huang, S and Sirikhachornkit, A and Faris, JD and Su, X and Gill, BS and Haselkorn, R and Gornicki, P}, title = {Phylogenetic analysis of the acetyl-CoA carboxylase and 3-phosphoglycerate kinase loci in wheat and other grasses.}, journal = {Plant molecular biology}, volume = {48}, number = {5-6}, pages = {805-820}, pmid = {11999851}, issn = {0167-4412}, mesh = {Acetyl-CoA Carboxylase/*genetics ; DNA, Plant/chemistry/genetics ; Molecular Sequence Data ; Phosphoglycerate Kinase/*genetics ; *Phylogeny ; Poaceae/classification/enzymology/*genetics ; Sequence Analysis, DNA ; Triticum/enzymology/*genetics ; }, abstract = {We have applied a two-gene system based on the sequences of nuclear genes encoding multi-domain plastid acetyl-CoA carboxylase (ACCase) and plastid 3-phosphoglycerate kinase (PGK) to study grass evolution. Our analysis revealed that these genes are single-copy in most of the grass species studied, allowing the establishment of orthologous relationships between them. These relationships are consistent with the known facts of their evolution: the eukaryotic origin of the plastid ACCase, created by duplication of a gene encoding the cytosolic multi-domain ACCase gene early in grass evolution, and the prokaryotic (endosymbiont) origin of the plastid PGK. The major phylogenetic relationships among grasses deduced from the nucleotide sequence comparisons of ACCase and PGK genes are consistent with each other and with the milestones of grass evolution revealed by other methods. Nucleotide substitution rates were calculated based on multiple pairwise sequence comparisons. On a relative basis, with the divergence of the Pooideae and Panicoideae subfamilies set at 60 million years ago (MYA), events leading to the Triticum/Aegilops complex occurred at the following intervals: divergence of Lolium (Lolium rigidum) at 35 MYA, divergence of Hordeum (Hordeum vulgare) at 11 MYA and divergence of Secale (Secale cereale) at 7 MYA. On the same scale, gene duplication leading to the multi-domain plastid ACCase in grasses occurred at 129 MYA, divergence of grass and dicot plastid PGK genes at 137 MYA, and divergence of grass and dicot cytosolic PGK genes at 155 MYA. The ACCase and PGK genes provide a well-understood two-locus system to study grass phylogeny, evolution and systematics.}, }
@article {pmid11992713, year = {2002}, author = {Egyed, Z and Sréter, T and Széll, Z and Nyirö, G and Dobos-Kovács, M and Márialigeti, K and Varga, I}, title = {Electron microscopic and molecular identification of Wolbachia endosymbionts from Onchocerca lupi: implications for therapy.}, journal = {Veterinary parasitology}, volume = {106}, number = {1}, pages = {75-82}, doi = {10.1016/s0304-4017(02)00029-8}, pmid = {11992713}, issn = {0304-4017}, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Dog Diseases/drug therapy/*parasitology ; Dogs ; Female ; Male ; Microscopy, Electron ; Onchocerca/genetics/growth &amp; development/*microbiology ; Onchocerciasis, Ocular/drug therapy/parasitology/*veterinary ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis ; Wolbachia/*genetics/growth &amp; development/ultrastructure ; }, abstract = {It was recently demonstrated that Wolbachia intracellular bacteria (alpha 2 proteobacteria, Rickettsiales) living in filarial nematodes are obligatory symbionts of their hosts. Herein, we report the electron microscopic and 16S ribosomal DNA-based (16S rDNA) identification of the endobacteria harboring in Onchocerca lupi. The worm nodules containing the nematodes were removed from three Hungarian dogs naturally infected with O. lupi. Wolbachia-like endobacteria were detected by electron microscopy in the lateral chords of both adult worms and microfilariae. The endosymbionts in O. lupi resemble in location, size, and morphology the wolbachiae found in other filariae. The presence of wolbachiae in O. lupi was also confirmed by PCR amplification of the 16S rDNA of the bacteria. The 16S rDNA-based phylogenetic analysis revealed that the endosymbionts of O. lupi infecting dogs belong to the supergroup C of Wolbachia pipientis and are not identical with those of other Onchocerca spp. sequenced so far. Since intermittent treatment with oxytetracycline has adulticid and microfilaricid activity by depletion of Wolbachia endobacteria, this antibiotic treatment regimen may offer an alternative of ivermectin or diethylcarbamazine in the suppression of postoperative microfilaridermia in Onchocerca-infected dogs and may prevent relapse.}, }
@article {pmid11989683, year = {2002}, author = {Ballard, JW and Chernoff, B and James, AC}, title = {Divergence of mitochondrial dna is not corroborated by nuclear dna, morphology, or behavior in Drosophila simulans.}, journal = {Evolution; international journal of organic evolution}, volume = {56}, number = {3}, pages = {527-545}, doi = {10.1111/j.0014-3820.2002.tb01364.x}, pmid = {11989683}, issn = {0014-3820}, mesh = {Animals ; Base Sequence ; Behavior, Animal/*physiology ; Cell Nucleus/*genetics ; DNA/*genetics ; DNA Primers ; DNA, Mitochondrial/*genetics ; Drosophila/classification/*genetics/physiology ; *Evolution, Molecular ; Female ; Genetic Variation ; Geography ; *Phylogeny ; Reproduction/physiology ; Wolbachia/classification/genetics/physiology ; X Chromosome ; }, abstract = {We ask whether the observed mitochondrial DNA (mtDNA) population subdivision of Drosophila simulans is indicative of organismal structure or of specific processes acting on the mitochondrial genome. Factors either intrinsic or extrinsic to the host genome may influence the evolutionary dynamics of mtDNA. Potential intrinsic factors include adaptation of the mitochondrial genome and of nucleomitochondrial gene complexes specific to the local environment. An extrinsic force that has been shown to influence mtDNA evolution in invertebrates is the bacterial endosymbiont Wolbachia. Evidence presented in this study suggests that mtDNA is not a good indicator of organismal subdivision in D. simulans. Furthermore, there is no evidence to suggest that Wolbachia causes any reduction in nuclear gene flow in this species. The observed differentiation in mtDNA is not corroborated by data from NADH: ubiquinone reductase 75kD subunit precursor or the Alcohol dehydrogenase-related loci, from the shape or size of the male genital arch, or from assortative premating behavior. We discuss these results in relation to a mitochondrial genetic species concept and the potential for Wolbachia-induced incompatibility to be a mechanism of speciation in insects. We conclude with an iterated appeal to include phylogenetic and statistical tests of neutrality as a supplement to phylogenetic and population genetic analyses when using mtDNA as an evolutionary marker.}, }
@article {pmid11976331, year = {2002}, author = {van Dooren, GG and Su, V and D'Ombrain, MC and McFadden, GI}, title = {Processing of an apicoplast leader sequence in Plasmodium falciparum and the identification of a putative leader cleavage enzyme.}, journal = {The Journal of biological chemistry}, volume = {277}, number = {26}, pages = {23612-23619}, doi = {10.1074/jbc.M201748200}, pmid = {11976331}, issn = {0021-9258}, mesh = {Alternative Splicing ; Amino Acid Sequence ; Animals ; Heme/biosynthesis ; Metalloendopeptidases/*analysis/genetics/physiology ; Molecular Sequence Data ; Phylogeny ; *Plant Proteins ; Plasmodium falciparum/*chemistry ; Porphobilinogen Synthase/genetics/physiology ; *Protein Sorting Signals ; Protozoan Proteins/chemistry/*metabolism ; }, abstract = {The plastid (apicoplast) of the malaria-causing parasite Plasmodium falciparum was derived via a secondary endosymbiotic process. As in other secondary endosymbionts, numerous genes for apicoplast proteins are located in the nucleus, and the encoded proteins are targeted to the organelle courtesy of a bipartite N-terminal extension. The first part of this leader sequence is a signal peptide that targets proteins to the secretory pathway. The second, so-called transit peptide region is required to direct proteins from the secretory pathway across the multiple membranes surrounding the apicoplast. In this paper we perform a pulse-chase experiment and N-terminal sequencing to show that the transit peptide of an apicoplast-targeted protein is cleaved, presumably upon import of the protein into the apicoplast. We identify a gene whose product likely performs this cleavage reaction, namely a stromal-processing peptidase (SPP) homologue. In plants SPP cleaves the transit peptides of plastid-targeted proteins. The P. falciparum SPP homologue contains a bipartite N-terminal apicoplast-targeting leader. Interestingly, it shares this leader sequence with a Delta-aminolevulinic acid dehydratase homologue via an alternative splicing event.}, }
@article {pmid11976137, year = {2002}, author = {Sabater-Muñoz, B and Gómez-Valero, L and van Ham, RC and Silva, FJ and Latorre, A}, title = {Molecular characterization of the leucine cluster in Buchnera sp. strain PSY, a primary endosymbiont of the aphid Pemphigus spyrothecae.}, journal = {Applied and environmental microbiology}, volume = {68}, number = {5}, pages = {2572-2575}, pmid = {11976137}, issn = {0099-2240}, mesh = {Animals ; Bacterial Proteins/genetics ; Base Sequence ; Buchnera/genetics/*metabolism ; Cloning, Molecular ; DNA, Bacterial/analysis ; Gene Amplification ; *Hydro-Lyases ; Leucine/genetics/*metabolism ; Molecular Sequence Data ; *Multigene Family ; Pemphigus/*microbiology ; Symbiosis/*physiology ; }, abstract = {Buchnera strains from most aphid subfamilies studied to date have been found to carry the leucine gene cluster (leuA, -B, -C, and -D) on a plasmid, an organization unique among bacteria. Here, however, we demonstrate a classical chromosomal location of the cluster in Buchnera sp. strain PSY from the aphid Pemphigus spyrothecae (subfamily Pemphiginae). The genes that flank leuABCD in Buchnera sp. strain PSY appear to be adjacent in the genome of Buchnera sp. strain APS, a strain carrying a leucine plasmid. We propose that the presence of a leucine plasmid predates the diversification of symbiotic Buchnera and that the chromosomal location observed in Buchnera sp. strain PSY arose by a transfer of the leucine genes from a plasmid to the chromosome.}, }
@article {pmid11966820, year = {2002}, author = {Embley, TM}, title = {Anaerobic eukaryotes and their archaebacterial endosymbionts.}, journal = {Environmental microbiology}, volume = {4}, number = {1}, pages = {15-16}, doi = {10.1046/j.1462-2920.2002.t01-4-00257.x}, pmid = {11966820}, issn = {1462-2912}, mesh = {Anaerobiosis ; Archaea/*physiology ; *Bacterial Physiological Phenomena ; Biological Evolution ; *Environmental Microbiology ; Eukaryotic Cells/*physiology ; Symbiosis ; }, }
@article {pmid11964873, year = {2001}, author = {Nutman, TB}, title = {Lymphatic filariasis: new insights and prospects for control.}, journal = {Current opinion in infectious diseases}, volume = {14}, number = {5}, pages = {539-546}, doi = {10.1097/00001432-200110000-00006}, pmid = {11964873}, issn = {0951-7375}, mesh = {Animals ; Elephantiasis, Filarial/diagnosis/*prevention &amp; control/therapy ; Humans ; Wuchereria bancrofti/genetics/immunology/pathogenicity ; }, abstract = {Although lymphatic filariasis remains among the major causes of disability among the tropical infectious diseases, dramatic advances have been made in the approach to its diagnosis, epidemiology and treatment, in our understanding of the molecular composition of the parasites that cause these infections, and in the factors underlying the pathology seen. Superimposing the tools of modern epidemiology, immunology, and molecular biology on field-based clinical trials has allowed the emergence of the concept of elimination of lymphatic filariasis. Much of the important new research emphasizes parasite development in the context of the host response, the importance of both the adult worm and other factors in the pathogenesis of lymphatic filarial disease, the role the Wolbachia endosymbiont holds as both a target for drug treatment and in inducing post-treatment reactions, and the various principles underlying the implementation of control programs.}, }
@article {pmid11964814, year = {2000}, author = {Mackenzie, CD}, title = {Human onchocerciasis: the essential partnership between research and disease control efforts.}, journal = {Current opinion in infectious diseases}, volume = {13}, number = {5}, pages = {457-464}, doi = {10.1097/00001432-200010000-00005}, pmid = {11964814}, issn = {1473-6527}, abstract = {Twenty years ago onchocerciasis was a disease generally ignored by the medical world, except by those who actually worked with the affected people in Africa and Latin America. Now, largely as a result of the success of mass vector control and drug treatment programs, this is a disease management model for developing countries. The recent literature on onchocerciasis has, not surprisingly, mainly focused on various aspects of control. Investigation into the more basic questions is needed to ensure continued effective disease control. The present mass drug control program is based on a single pharmaceutical, ivermectin (Mectizan), which acts almost exclusively on the microfilarial stage of the infection. Efforts are being made to identify other useful drugs; however, no major candidates have yet appeared. The identification of potential biochemical targets for anti-filarial compounds through a better understanding of the biochemistry of these worms is being pursued. The Onchocerca volvulus endosymbiont Wolbachia may provide a target for therapeutic intervention. An improved understanding of the genomics of O. volvulus has made possible the identification of strain differences in the parasites, and an appreciation of the relevance of these strain differences to the clinical disease, onchocerciasis. There is a need for a better understanding of the clinical disease, and the various pathogenic mechanisms that underly the different syndromes. It is particularly important to understand the pathological basis and mechanisms underlying the adverse responses that can occur with chemotherapy. Present control programs now need to be carefully monitored for effectiveness using new assessment tools, such as antigen assays and the identification of organisms in pools of vectors. Current efforts to control onchocerciasis must be coordinated with new chemotherapy-based control programs for other worm diseases that are emerging. The results of laboratory studies are increasingly being applied to improve the effectiveness of field-based control programs and their assessment. Such research is essential for progress towards the goals of controlling and eliminating onchocerciasis.}, }
@article {pmid11950614, year = {2002}, author = {Zerges, W}, title = {Does complexity constrain organelle evolution?.}, journal = {Trends in plant science}, volume = {7}, number = {4}, pages = {175-182}, doi = {10.1016/s1360-1385(02)02233-1}, pmid = {11950614}, issn = {1360-1385}, mesh = {*Biological Evolution ; Chloroplasts/genetics/physiology ; Light ; Mitochondria/genetics/physiology ; Organelles/genetics/*physiology ; Oxidation-Reduction ; Photosynthesis/genetics/*physiology ; Photosynthetic Reaction Center Complex Proteins/genetics/*metabolism ; *Selection, Genetic ; }, abstract = {The evolution of eukaryotes was punctuated by invasions of the bacteria that have evolved to mitochondria and plastids. These bacterial endosymbionts founded major eukaryotic lineages by enabling them to carry out aerobic respiration and oxygenic photosynthesis. Yet, having evolved as free-living organisms, they were at first poorly adapted organelles. Although mitochondria and plastids have integrated within the physiology of eukaryotic cells, this integration has probably been constrained by the high level of complexity of their bacterial ancestors and the inability of gradual evolutionary processes to drastically alter complex systems. Here, I review complex processes that directly involve translation of plastid mRNAs and how they could constrain transfer to the nucleus of the genes encoding them.}, }
@article {pmid11943228, year = {2002}, author = {Monis, PT and Andrews, RH and Saint, CP}, title = {Molecular biology techniques in parasite ecology.}, journal = {International journal for parasitology}, volume = {32}, number = {5}, pages = {551-562}, doi = {10.1016/s0020-7519(01)00352-6}, pmid = {11943228}, issn = {0020-7519}, mesh = {Animals ; *Ecosystem ; Host-Parasite Interactions ; Humans ; Molecular Biology/*methods ; Parasites/*classification/*genetics/growth &amp; development ; }, abstract = {Molecular techniques are increasingly being used to study the ecology of a variety of organisms. These techniques represent important tools for the study of the systematics, population genetics, biogeography and ecology of parasites. Here, we review the techniques that have been employed to study the ecology and systematics of parasites (including bacteria and viruses). Particular emphasis is placed on the techniques of isoenzyme electrophoresis, in situ hybridisation and nucleic acid amplification to characterise parasite/microbial communities. The application of these techniques will be exemplified using ticks, bacterial endosymbionts and parasitic protozoa.}, }
@article {pmid11931173, year = {2002}, author = {Horn, M and Fritsche, TR and Linner, T and Gautom, RK and Harzenetter, MD and Wagner, M}, title = {Obligate bacterial endosymbionts of Acanthamoeba spp. related to the beta-Proteobacteria: proposal of 'Candidatus Procabacter acanthamoebae' gen. nov., sp. nov.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {52}, number = {Pt 2}, pages = {599-605}, doi = {10.1099/00207713-52-2-599}, pmid = {11931173}, issn = {1466-5026}, support = {FO6 TW02279-01/TW/FIC NIH HHS/United States ; }, mesh = {Acanthamoeba/classification/isolation &amp; purification/*microbiology ; Animals ; Base Sequence ; Betaproteobacteria/*classification/genetics/isolation &amp; purification ; DNA, Bacterial/chemistry ; DNA, Protozoan/chemistry ; Environmental Microbiology ; Humans ; Malaysia ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; Polymorphism, Genetic ; RNA, Protozoan/genetics ; RNA, Ribosomal, 16S/chemistry ; RNA, Ribosomal, 18S/chemistry ; RNA, Ribosomal, 23S/chemistry ; Sequence Homology, Nucleic Acid ; Symbiosis ; United States ; }, abstract = {All obligate bacterial endosymbionts of free-living amoebae currently described are affiliated with the alpha-Proteobacteria, the Chlamydiales or the phylum Cytophaga-Flavobacterium-Bacteroides. Here, six rod-shaped gram-negative obligate bacterial endosymbionts of clinical and environmental isolates of Acanthamoeba spp. from the USA and Malaysia are reported. Comparative 16S rDNA sequence analysis demonstrated that these endosymbionts form a novel, monophyletic lineage within the beta-Proteobacteria, showing less than 90% sequence similarity to all other recognized members of this subclass. 23S rDNA sequence analysis of two symbionts confirmed this affiliation and revealed the presence of uncommon putative intervening sequences of 146 bp within helix-25 that shared no sequence homology to any other bacterial rDNA. In addition, the 23S rRNA of these endosymbionts displayed one polymorphism at the target site of oligonucleotide probe BET42a that is conserved in all other sequenced beta-Proteobacteria. Intra-cytoplasmatic localization of the endosymbionts within the amoebal host cells was confirmed by electron microscopy and fluorescence in situ hybridization with a specific 16S rRNA-targeted oligonucleotide probe. Based on these findings, the provisional name 'Candidatus Procabacter acanthamoebae' is proposed for classification of a representative of the six endosymbionts of Acanthamoeba spp. studied in this report. Comparative 18S rDNA sequence analysis of the Acanthamoeba host cells revealed their membership with either Acanthamoeba 18S rDNA sequence type T5 (Acanthamoeba lenticulata) or sequence type T4, which comprises the majority of all Acanthamoeba isolates.}, }
@article {pmid11920298, year = {2002}, author = {Keiser, PB and Reynolds, SM and Awadzi, K and Ottesen, EA and Taylor, MJ and Nutman, TB}, title = {Bacterial endosymbionts of Onchocerca volvulus in the pathogenesis of posttreatment reactions.}, journal = {The Journal of infectious diseases}, volume = {185}, number = {6}, pages = {805-811}, doi = {10.1086/339344}, pmid = {11920298}, issn = {0022-1899}, mesh = {Adolescent ; Adult ; Calcium-Binding Proteins/blood ; Calgranulin B ; DNA, Bacterial/analysis ; Diethylcarbamazine/*adverse effects ; Filaricides/*adverse effects ; Humans ; Ivermectin/*adverse effects ; Leukocyte L1 Antigen Complex ; Male ; Membrane Glycoproteins/blood ; Neural Cell Adhesion Molecules/blood ; Onchocerciasis/*drug therapy/immunology ; *Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {Treatment of onchocerciasis with diethylcarbamazine (DEC) or ivermectin is associated with a posttreatment reaction characterized by fever, tachycardia, hypotension, lymphadenopathy, and pruritus. To investigate the role of the Wolbachia bacterial endosymbiont of Onchocerca volvulus in these reactions, serum samples collected before and after treatment with either anthelmintic were assessed for evidence of Wolbachia DNA. By use of real-time quantitative polymerase chain reaction, Wolbachia DNA was detected in both groups-with significantly higher levels in those who received DEC (P <.0001). In the ivermectin group, there was a significant correlation between levels of bacterial DNA and serum tumor necrosis factor-alpha (P =.013). Peak DNA levels correlated with reaction scores (P =.048). Significant correlations were also seen between Wolbachia DNA and the antibacterial peptides calprotectin (P =.021) and calgranulin B (P <.0001). These findings support a role for Wolbachia products in mediating the inflammatory responses seen following treatment of onchocerciasis and suggest new targets for modulating these reactions.}, }
@article {pmid11920134, year = {2002}, author = {Kittayapong, P and Mongkalangoon, P and Baimai, V and O'Neill, SL}, title = {Host age effect and expression of cytoplasmic incompatibility in field populations of Wolbachia-superinfected Aedes albopictus.}, journal = {Heredity}, volume = {88}, number = {4}, pages = {270-274}, doi = {10.1038/sj.hdy.6800039}, pmid = {11920134}, issn = {0018-067X}, mesh = {Aedes/*microbiology/physiology ; Age Factors ; Animals ; Crosses, Genetic ; Cytoplasm/*physiology ; DNA/metabolism ; Female ; Male ; Polymerase Chain Reaction ; Wolbachia/*physiology ; }, abstract = {The Asian tiger mosquito, Aedes albopictus (Skuse), is a known vector of dengue in South America and Southeast Asia. It is naturally superinfected with two strains of Wolbachia endosymbiont that are able to induce cytoplasmic incompatibility (CI). In this paper, we report the strength of CI expression in crosses involving field-caught males. CI expression was found to be very strong in all crosses between field males and laboratory-reared uninfected or wAlbA infected young females. In addition, crossing experiments with laboratory colonies showed that aged super-infected males could express strong CI when mated with young uninfected or wAlbA infected females. These results provide additional evidence that the CI properties of Wolbachia infecting Aedes albopictus are well suited for applied strategies that seek to utilise Wolbachia for host population modification.}, }
@article {pmid11886773, year = {2002}, author = {Kellner, RL}, title = {Molecular identification of an endosymbiotic bacterium associated with pederin biosynthesis in Paederus sabaeus (Coleoptera: Staphylinidae).}, journal = {Insect biochemistry and molecular biology}, volume = {32}, number = {4}, pages = {389-395}, doi = {10.1016/s0965-1748(01)00115-1}, pmid = {11886773}, issn = {0965-1748}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Base Sequence ; Coleoptera/*microbiology ; DNA, Bacterial ; Female ; Molecular Sequence Data ; Molecular Structure ; Phylogeny ; Pyrans/chemistry/*metabolism ; RNA, Bacterial/analysis ; RNA, Ribosomal, 16S/analysis ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Biosynthesis of the structurally complex hemolymph toxin pederin is an eminent character of Paederus females. For that capability, however, they rely on endosymbiotic bacteria that are lacking in aposymbiotic females. The bacterial inhabitants of the two phenotypes in Paederus sabaeus are evaluated in a PCR-based analysis of 16S rDNA. A certain fragment, which is not found in aposymbiotic females, is highly dominant in the other, biosynthesizing females and thus identifies the endosymbiont. Its DNA sequence reveals a member of the gamma subdivision of the Proteobacteria that is clustered within the genus Pseudomonas (sensu stricto) as it is most closely related to Pseudomonas aeruginosa. These bacteria appear as the hypothesized common producers of pederin and the pederin family of analogs from marine sponges.}, }
@article {pmid11812492, year = {2002}, author = {Ware, J and Moran, L and Foster, J and Posfai, J and Vincze, T and Guiliano, D and Blaxter, M and Eisen, J and Slatko, B}, title = {Sequencing and analysis of a 63 kb bacterial artificial chromosome insert from the Wolbachia endosymbiont of the human filarial parasite Brugia malayi.}, journal = {International journal for parasitology}, volume = {32}, number = {2}, pages = {159-166}, doi = {10.1016/s0020-7519(01)00367-8}, pmid = {11812492}, issn = {0020-7519}, mesh = {Animals ; Base Sequence ; Brugia malayi/*microbiology ; Chromosomes, Artificial, Bacterial/chemistry/*genetics ; DNA, Bacterial/chemistry/genetics ; Molecular Sequence Data ; Open Reading Frames/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Wolbachia/chemistry/*genetics ; }, abstract = {Wolbachia endosymbiotic bacteria are widespread in filarial nematodes and are directly involved in the immune response of the host. In addition, antibiotics which disrupt Wolbachia interfere with filarial nematode development thus, Wolbachia provide an excellent target for control of filariasis. A 63.1 kb bacterial artificial chromosome insert, from the Wolbachia endosymbiont of the human filarial parasite Brugia malayi, has been sequenced using the New England Biolabs Inc. Genome Priming System() transposition kit in conjunction with primer walking methods. The bacterial artificial chromosome insert contains approximately 57 potential ORFs which have been compared by individual protein BLAST analysis with the 35 published complete microbial genomes in the Comprehensive Microbial Resource database at The Institute for Genomic Research and in the NCBI GenBank database, as well as to data from 22 incomplete genomes from the DOE Joint Genome Institute. Twenty five of the putative ORFs have significant similarity to genes from the alpha-proteobacteria Rickettsia prowazekii, the most closely related completed genome, as well as to the newly sequenced alpha-proteobacteria endosymbiont Sinorhizobium meliloti. The bacterial artificial chromosome insert sequence however has little conserved synteny with the R. prowazekii and S. meliloti genomes. Significant sequence similarity was also found in comparisons with the currently available sequence data from the Wolbachia endosymbiont of Drosophila melanogaster. Analysis of this bacterial artificial chromosome insert provides useful gene density and comparative genomic data that will contribute to whole genome sequencing of Wolbachia from the B. malayi host. This will also lead to a better understanding of the interactions between the endosymbiont and its host and will offer novel approaches and drug targets for elimination of filarial disease.}, }
@article {pmid11790257, year = {2001}, author = {Moran, NA and Mira, A}, title = {The process of genome shrinkage in the obligate symbiont Buchnera aphidicola.}, journal = {Genome biology}, volume = {2}, number = {12}, pages = {RESEARCH0054}, pmid = {11790257}, issn = {1474-760X}, mesh = {Buchnera/*genetics/metabolism ; DNA Repair ; DNA, Bacterial/genetics ; DNA, Intergenic ; Escherichia coli/genetics ; *Evolution, Molecular ; *Gene Deletion ; Gene Expression Regulation, Bacterial ; Gene Frequency ; Gene Rearrangement ; *Genome, Bacterial ; Phylogeny ; Promoter Regions, Genetic ; RNA, Bacterial/genetics ; Symbiosis ; Synteny ; }, abstract = {BACKGROUND: Very small genomes have evolved repeatedly in eubacterial lineages that have adopted obligate associations with eukaryotic hosts. Complete genome sequences have revealed that small genomes retain very different gene sets, raising the question of how final genome content is determined. To examine the process of genome reduction, the tiny genome of the endosymbiont Buchnera aphidicola was compared to the larger ancestral genome, reconstructed on the basis of the phylogenetic distribution of gene orthologs among fully sequenced relatives of Escherichia coli and Buchnera.<br><br>RESULTS: The reconstructed ancestral genome contained 2,425 open reading frames (ORFs). The Buchnera genome, containing 564 ORFs, consists of 153 fragments of 1-34 genes that are syntenic with reconstructed ancestral regions. On the basis of this reconstruction, 503 genes were eliminated within syntenic fragments, and 1,403 genes were lost from the gaps between syntenic fragments, probably in connection with genome rearrangements. Lost regions are sometimes large, and often span functionally unrelated genes. In addition, individual genes and regulatory regions have been lost or eroded. For the categories of DNA repair genes and rRNA genes, most lost loci fall in regions between syntenic fragments. This history of gene loss is reflected in the sequences of intergenic spacers at positions where genes were once present.<br><br>CONCLUSIONS: The most plausible interpretation of this reconstruction is that Buchnera lost many genes through the fixation of large deletions soon after the acquisition of an obligate endosymbiotic lifestyle. An implication is that final genome composition may be partly the chance outcome of initial deletions and that neighboring genes influence the likelihood of loss of particular genes and pathways.}, }
@article {pmid11750661, year = {2001}, author = {van Dooren, GG and Schwartzbach, SD and Osafune, T and McFadden, GI}, title = {Translocation of proteins across the multiple membranes of complex plastids.}, journal = {Biochimica et biophysica acta}, volume = {1541}, number = {1-2}, pages = {34-53}, doi = {10.1016/s0167-4889(01)00154-9}, pmid = {11750661}, issn = {0006-3002}, mesh = {Amino Acid Sequence ; Cell Membrane/*metabolism ; Chloroplasts/metabolism ; Cyanobacteria ; Endoplasmic Reticulum/metabolism ; Eukaryota ; Intracellular Membranes/*metabolism ; Models, Chemical ; Molecular Sequence Data ; Plant Proteins/*metabolism ; Plastids/*metabolism ; *Protein Transport ; Sequence Alignment ; Symbiosis ; }, abstract = {Secondary endosymbiosis describes the origin of plastids in several major algal groups such as dinoflagellates, euglenoids, heterokonts, haptophytes, cryptomonads, chlorarachniophytes and parasites such as apicomplexa. An integral part of secondary endosymbiosis has been the transfer of genes for plastid proteins from the endosymbiont to the host nucleus. Targeting of the encoded proteins back to the plastid from their new site of synthesis in the host involves targeting across the multiple membranes surrounding these complex plastids. Although this process shows many overall similarities in the different algal groups, it is emerging that differences exist in the mechanisms adopted.}, }
@article {pmid11741630, year = {2001}, author = {Cross, HF and Haarbrink, M and Egerton, G and Yazdanbakhsh, M and Taylor, MJ}, title = {Severe reactions to filarial chemotherapy and release of Wolbachia endosymbionts into blood.}, journal = {Lancet (London, England)}, volume = {358}, number = {9296}, pages = {1873-1875}, doi = {10.1016/S0140-6736(01)06899-4}, pmid = {11741630}, issn = {0140-6736}, mesh = {Animals ; *Brugia malayi ; Diethylcarbamazine/*adverse effects ; Filariasis/blood/*drug therapy ; Filaricides/*adverse effects ; Humans ; Polymerase Chain Reaction ; Severity of Illness Index ; Systemic Inflammatory Response Syndrome/*chemically induced/classification/microbiology ; Wolbachia/*isolation &amp; purification ; }, abstract = {Wolbachia bacteria seem to have evolved as essential endosymbionts of their filarial nematode hosts. Studies in mice have suggested that these bacteria are associated with systemic inflammatory reactions to filarial chemotherapy. We took blood samples from 15 Indonesian patients before and after treatment with diethylcarbamazine for Brugia malayi infection, and recorded the severity of any post-treatment inflammatory reactions. Blood from all three patients with severe adverse reactions and from one of six with moderate reactions was positive for Wolbachia DNA 4-48 h after diethylcarbamazine treatment. We suggest that these severe inflammatory reactions are associated with the release of endosymbionts into the blood after treatment for filariasis.}, }
@article {pmid11737290, year = {2001}, author = {Michel-Salzat, A and Cordaux, R and Bouchon, D}, title = {Wolbachia diversity in the Porcellionides pruinosus complex of species (Crustacea: Oniscidea): evidence for host-dependent patterns of infection.}, journal = {Heredity}, volume = {87}, number = {Pt 4}, pages = {428-434}, doi = {10.1046/j.1365-2540.2001.00920.x}, pmid = {11737290}, issn = {0018-067X}, mesh = {Animals ; Bacterial Infections/microbiology ; Base Sequence ; Biological Evolution ; Crustacea/*genetics/*microbiology ; DNA, Mitochondrial/genetics ; Ecosystem ; Genes, Bacterial/genetics ; Genetic Variation/*genetics ; Haplotypes/genetics ; Host-Parasite Interactions/*genetics ; Likelihood Functions ; Male ; Molecular Sequence Data ; Phylogeny ; Sequence Homology, Nucleic Acid ; Species Specificity ; Symbiosis/genetics ; Wolbachia/classification/*genetics ; }, abstract = {Porcellionides pruinosus is a cosmopolitan woodlouse. It is known to exhibit patterns of geographical variation between populations, and has been suspected to consist of several very closely related species. This species was found to carry Wolbachia endosymbionts, alpha-proteobacteria which are known to modify the reproduction of their crustacean hosts by inducing cytoplasmic incompatibility or feminization. In the P. pruinosus complex, Wolbachia induced feminization, but two different patterns of infection were reported: high prevalence and presence of infected males, or low prevalence and absence of infected males. In this study we investigated nine populations described as Porcellionides pruinosus carrying different Wolbachia strains, with the aim of investigating the possibility of coevolution between symbionts and hosts. Molecular analyses were carried out on both Wolbachia DNA (wsp gene) and host mitochondrial DNA (mt LSU rDNA). We show that (1) the nine host populations exhibited a high genetic differentiation so that they have to be split into two sibling species; (2) three different Wolbachia strains were found in the host complex but were not species-specific; and (3) the pattern of infection by Wolbachia was more host-dependent than symbiont-dependent.}, }
@article {pmid11737276, year = {2001}, author = {Rokas, A and Atkinson, RJ and Brown, GS and West, SA and Stone, GN}, title = {Understanding patterns of genetic diversity in the oak gallwasp Biorhiza pallida: demographic history or a Wolbachia selective sweep?.}, journal = {Heredity}, volume = {87}, number = {Pt 3}, pages = {294-304}, doi = {10.1046/j.1365-2540.2001.00872.x}, pmid = {11737276}, issn = {0018-067X}, mesh = {Animals ; Base Sequence ; Cytochrome b Group/chemistry/genetics ; DNA Primers/chemistry ; DNA, Bacterial/analysis ; DNA, Mitochondrial/genetics ; Europe ; Female ; *Genetic Variation ; Haplotypes/genetics ; Isoenzymes/metabolism ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Wasps/*genetics/microbiology ; Wolbachia/*physiology ; }, abstract = {The endosymbiont Wolbachia can be responsible for selective sweeps on mitochondrial DNA variability within species. Similar signals can also result from demographic processes, although crucially the latter affect nuclear as well as mitochondrial loci. Here we present data on Wolbachia infection status and phylogeographic patterning for a widely distributed insect host, the oak gallwasp Biorhiza pallida (Hymenoptera: Cynipidae). Two hundred and eighteen females from eight European countries were screened for Wolbachia. All individuals from Hungary, Italy, France, U.K., Ireland, Switzerland, Sweden, and northern and southern Spain were infected with a single group A strain of Wolbachia, while populations in central Spain were not infected. A mitochondrial marker (cytochrome b) shows low variation and departure from neutrality in infected populations, but greater variation and no deviation from neutrality in Wolbachia-free populations. This pattern is compatible with a Wolbachia-induced selective sweep. However, we also find parallel differences between infected and uninfected populations for nuclear markers (sequence data for ITS1 and ITS2). All markers support the existence of a deep split between populations in Spain (some free of Wolbachia), and those in the rest of Europe (all infected). Allelic variation for five allozyme loci is also consistent with the Spain-rest of Europe split. Concordant patterns for nuclear and mitochondrial markers suggest that differences in the nature and extent of genetic diversity between these two regions are best explained by differing demographic histories (perhaps associated with range expansion from Pleistocene glacial refugia), rather than a Wolbachia-associated selective sweep.}, }
@article {pmid11732319, year = {2001}, author = {Szklarzewicz, T and Moskal, A}, title = {Ultrastructure, distribution, and transmission of endosymbionts in the whitefly Aleurochiton aceris Modeer (Insecta, Hemiptera, Aleyrodinea).}, journal = {Protoplasma}, volume = {218}, number = {1-2}, pages = {45-53}, pmid = {11732319}, issn = {0033-183X}, mesh = {Animals ; Female ; Hemiptera/*cytology/*microbiology/physiology ; Microscopy, Fluorescence ; Oocytes/physiology/ultrastructure ; Ovary/cytology ; Symbiosis/*physiology ; Vitellogenesis/physiology ; }, abstract = {The body of the whitefly Aleurochiton aceris contains specialized cells, termed mycetocytes, that enclose endosymbiotic microorganisms. The endosymbionts are transmitted from one generation to the next transovarially. In contrast to other insects, in whiteflies whole intact mycetocytes migrate into the ovaries, traverse the follicular epithelium, and reach the oocyte surface (i.e., perivitellin space). The migration of mycetocytes begins in the last instar, called puparium, from which imagines emerge. During this stage the cytoplasm of mycetocytes is tightly packed with pleomorphic bacteria and less numerous coccoid microorganisms. In adult females the mycetocytes gather extracellularly in the depression of the vitellarial oocyte. Till the end of oogenesis neither pleomorphic nor coccoid microorganisms are released from mycetocytes into the oocyte.}, }
@article {pmid11724564, year = {2001}, author = {Beynon, JD and MacRae, IJ and Huston, SL and Nelson, DC and Segel, IH and Fisher, AJ}, title = {Crystal structure of ATP sulfurylase from the bacterial symbiont of the hydrothermal vent tubeworm Riftia pachyptila.}, journal = {Biochemistry}, volume = {40}, number = {48}, pages = {14509-14517}, doi = {10.1021/bi015643l}, pmid = {11724564}, issn = {0006-2960}, support = {T32GM07377/GM/NIGMS NIH HHS/United States ; }, mesh = {Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Animals ; Bacteria/*enzymology ; Cloning, Molecular ; Crystallization ; Crystallography, X-Ray ; Hot Temperature ; Molecular Sequence Data ; Peptide Fragments/chemistry ; Plasmids ; Polychaeta/*microbiology ; Protein Conformation ; Sequence Homology, Amino Acid ; Sulfate Adenylyltransferase/*chemistry/metabolism ; Sulfates/chemistry/metabolism ; Symbiosis/*genetics ; }, abstract = {In sulfur chemolithotrophic bacteria, the enzyme ATP sulfurylase functions to produce ATP and inorganic sulfate from APS and inorganic pyrophosphate, which is the final step in the biological oxidation of hydrogen sulfide to sulfate. The giant tubeworm, Riftia pachyptila, which lives near hydrothermal vents on the ocean floor, harbors a sulfur chemolithotroph as an endosymbiont in its trophosome tissue. This yet-to-be-named bacterium was found to contain high levels of ATP sulfurylase that may provide a substantial fraction of the organisms ATP. We present here, the crystal structure of ATP sulfurylase from this bacterium at 1.7 A resolution. As predicted from sequence homology, the enzyme folds into distinct N-terminal and catalytic domains, but lacks the APS kinase-like C-terminal domain that is present in fungal ATP sulfurylase. The enzyme crystallizes as a dimer with one subunit in the crystallographic asymmetric unit. Many buried solvent molecules mediate subunit contacts at the interface. Despite the high concentration of sulfate needed for crystallization, no ordered sulfate was observed in the sulfate-binding pocket. The structure reveals a mobile loop positioned over the active site. This loop is in a "closed" or "down" position in the reported crystal structures of fungal ATP sulfurylases, which contained bound substrates, but it is in an "open" or "up" position in the ligand-free Riftia symbiont enzyme. Thus, closure of the loop correlates with occupancy of the active site, although the loop itself does not interact directly with bound ligands. Rather, it appears to assist in the orientation of residues that do interact with active-site ligands. Amino acid differences between the mobile loops of the enzymes from sulfate assimilators and sulfur chemolithotrophs may account for the significant kinetic differences between the two classes of ATP sulfurylase.}, }
@article {pmid11682181, year = {2001}, author = {Horn, M and Wagner, M}, title = {Evidence for additional genus-level diversity of Chlamydiales in the environment.}, journal = {FEMS microbiology letters}, volume = {204}, number = {1}, pages = {71-74}, doi = {10.1111/j.1574-6968.2001.tb10865.x}, pmid = {11682181}, issn = {0378-1097}, mesh = {Chlamydiales/*classification/*genetics ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal/analysis/genetics ; Industrial Waste ; Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Sewage/*microbiology ; Waste Disposal, Fluid ; }, abstract = {The medically important order Chlamydiales has long been considered to contain a few closely related bacteria which occur exclusively in animals and humans. This perception of diversity and habitat had to be revised with the recent identification of the genera Simkania, Waddlia, Parachlamydia, and Neochlamydia with the latter two comprising endosymbionts of amoebae. Application of a newly developed PCR assay for the specific amplification of a near full length 16S rDNA fragment of these novel Chlamydia-related bacteria on activated sludge samples revealed the existence of at least four additional, previously unknown evolutionary lineages of Chlamydiales (each showing less than 92% 16S rRNA sequence similarity with all recognized members of this order). These findings suggest that some waste water treatment plants represent reservoirs for a diverse assemblage of environmental chlamydiae, a discovery which might also be of relevance from the viewpoint of human public health.}, }
@article {pmid11679361, year = {2001}, author = {Fukatsu, T}, title = {Secondary intracellular symbiotic bacteria in aphids of the genus Yamatocallis (Homoptera: Aphididae: Drepanosiphinae).}, journal = {Applied and environmental microbiology}, volume = {67}, number = {11}, pages = {5315-5320}, pmid = {11679361}, issn = {0099-2240}, mesh = {Animals ; Aphids/*microbiology ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal/analysis/genetics ; Gammaproteobacteria/*classification/genetics/*isolation &amp; purification/physiology ; In Situ Hybridization ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {A novel secondary intracellular symbiotic bacterium from aphids of the genus Yamatocallis (subfamily Drepanosiphinae) was characterized by using molecular phylogenetic analysis, in situ hybridization, and diagnostic PCR detection. In the aphid tissues, this bacterium (tentatively designated YSMS [Yamatocallis secondary mycetocyte symbiont]) was found specifically in large cells surrounded by primary mycetocytes harboring Buchnera cells. Of nine drepanosiphine aphids examined, YSMS was detected in only two species of the same genus, Yamatocallis tokyoensis and Yamatocallis hirayamae. In natural populations of these aphids, YSMS was present in 100% of the individuals. Phylogenetic analysis based on 16S ribosomal DNA (rDNA) sequences demonstrated that YSMS of Y. tokyoensis and Y. hirayamae constitute a distinct and isolated clade in the gamma subdivision of the class Proteobacteria. No 16S rDNA sequences of secondary endosymbionts characterized so far from other aphids showed phylogenetic affinity to YSMS. Based on these results, I suggest that YSMS was acquired by an ancestor of the genus Yamatocallis and has been conserved throughout the evolution of the lineage. By using the nucleotide substitution rate for 16S rDNA of Buchnera spp., the time of acquisition of YSMS was estimated to be about 13 to 26 million years ago, in the Miocene epoch of the Tertiary period.}, }
@article {pmid11672844, year = {2001}, author = {Silva, FJ and Latorre, A and Moya, A}, title = {Genome size reduction through multiple events of gene disintegration in Buchnera APS.}, journal = {Trends in genetics : TIG}, volume = {17}, number = {11}, pages = {615-618}, doi = {10.1016/s0168-9525(01)02483-0}, pmid = {11672844}, issn = {0168-9525}, mesh = {Biological Evolution ; Buchnera/*genetics ; Escherichia coli/genetics ; Gene Deletion ; *Genome, Bacterial ; Pseudogenes ; Vibrio cholerae/genetics ; }, abstract = {The evolution of the endosymbiont Buchnera during its adaptation to intracellular life involved a massive reduction in its genome. By comparing the orthologous genes of Buchnera, Escherichia coli and Vibrio cholerae, we show that the minimal genome size of Buchnera arose from multiple events of gene disintegration dispersed over the whole genome. The elimination of the genes was a continuous process that began with gene inactivation and progressed until the DNA corresponding to the pseudogenes were completely deleted.}, }
@article {pmid11642360, year = {2001}, author = {Hoffmann, M and Kuhn, J and Däschner, K and Binder, S}, title = {The RNA world of plant mitochondria.}, journal = {Progress in nucleic acid research and molecular biology}, volume = {70}, number = {}, pages = {119-154}, doi = {10.1016/s0079-6603(01)70015-3}, pmid = {11642360}, issn = {0079-6603}, mesh = {Base Sequence ; Genome, Plant ; Mitochondria/*genetics ; Plants/*genetics ; RNA Processing, Post-Transcriptional ; RNA, Plant/*genetics/metabolism ; Transcription, Genetic ; }, abstract = {Mitochondria are well known as the cellular power factory. Much less is known about these organelles as a genetic system. This is particularly true for mitochondria of plants, which subsist with respect to attention by the scientific community in the shadow of the chloroplasts. Nevertheless the mitochondrial genetic system is essential for the function of mitochondria and thus for the survival of the plant. In plant mitochondria the pathway from the genetic information encoded in the DNA to the functional protein leads through a very diverse RNA world. How the RNA is generated and what kinds of regulation and control mechanisms are operative in transcription are current topics in research. Furthermore, the modes of posttranscriptional alterations and their consequences for RNA stability and thus for gene expression in plant mitochondria are currently objects of intensive investigations. In this article current results obtained in the examination of plant mitochondrial transcription, RNA processing, and RNA stability are illustrated. Recent developments in the characterization of promoter structure and the respective transcription apparatus as well as new aspects of RNA processing steps including mRNA 3' processing and stability, mRNA polyadenylation, RNA editing, and tRNA maturation are presented. We also consider new suggestions concerning the endosymbiont hypothesis and evolution of mitochondria. These novel considerations may yield important clues for the further analysis of the plant mitochondrial genetic system. Conversely, an increasing knowledge about the mechanisms and components of the organellar genetic system might reveal new aspects of the evolutionary history of mitochondria.}, }
@article {pmid11605956, year = {2001}, author = {Koltai, H and Dhandaydham, M and Opperman, C and Thomas, J and Bird, D}, title = {Overlapping plant signal transduction pathways induced by a parasitic nematode and a rhizobial endosymbiont.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {14}, number = {10}, pages = {1168-1177}, doi = {10.1094/MPMI.2001.14.10.1168}, pmid = {11605956}, issn = {0894-0282}, mesh = {Amino Acid Sequence ; Animals ; Cell Cycle Proteins/genetics/physiology ; Cell Size ; DNA-Binding Proteins/genetics/physiology ; Gene Expression Regulation, Plant ; Growth Substances/genetics/physiology ; Homeodomain Proteins/genetics/physiology ; Host-Parasite Interactions ; Humans ; Medicago/genetics/microbiology/parasitology ; Mitosis ; Molecular Sequence Data ; Nematoda/genetics/physiology ; Nuclear Proteins/genetics/physiology ; *Plant Diseases/microbiology/parasitology ; Plant Proteins/genetics/*physiology ; Plant Roots/genetics/microbiology/parasitology ; *Proto-Oncogene Proteins c-myb ; Sequence Homology, Amino Acid ; Signal Transduction/*physiology ; Sinorhizobium meliloti/genetics/physiology ; Symbiosis ; }, abstract = {Root-knot nematodes and rhizobia establish interactions with roots characterized by the de novo induction of host structures, termed giant cells and nodules, respectively. Two transcription regulators, PHAN and KNOX, required for the establishment of meristems were previously shown to be expressed in tomato giant cells. We isolated the orthologues of PHAN and KNOX (Mt-phan and Mt-knox-1) from the model legume Medicago truncatula, and established the spatial distribution of their expression in situ. We confirmed that Mt-phan and Mt-knox-1 are expressed in lateral root initials and in nematode-induced giant cells and showed that they are expressed in nodules induced by Sinorhizobium meliloti. Expression of both genes becomes spatially restricted as the nodules develop. We further examined nematode feeding sites for the expression of two genes involved in nodule formation, ccs52 (encodes a mitotic inhibitor) and ENOD40 (encodes an early, nodulation mitogen), and found transcripts of both genes to be present in and around giant cells induced in Medicago. Collectively, these results reveal common elements of host responses to mutualistic and parasitic plant endosymbionts and imply that overlapping regulatory pathways lead to giant cells and nodules. We discuss these pathways in the context of phytohormones and parallels between beneficial symbiosis and disease.}, }
@article {pmid11595053, year = {2001}, author = {Olsen, K and Reynolds, KT and Hoffmann, AA}, title = {A field cage test of the effects of the endosymbiont Wolbachia on Drosophila melanogaster.}, journal = {Heredity}, volume = {86}, number = {Pt 6}, pages = {731-737}, doi = {10.1046/j.1365-2540.2001.00892.x}, pmid = {11595053}, issn = {0018-067X}, mesh = {Analysis of Variance ; Animals ; Climate ; Drosophila melanogaster/*microbiology/*physiology ; Female ; Fertility ; Male ; Queensland ; Seasons ; Survival Rate ; *Symbiosis ; Victoria ; Wolbachia/pathogenicity/*physiology ; }, abstract = {Wolbachia endosymbionts are known to affect the fitness of their hosts, but most of this information is from laboratory studies. In Drosophila melanogaster, Wolbachia frequencies vary clinically in frequency in Australia and may confound climatic adaptation. Here we use field cages in a reciprocal exchange design to test for Wolbachia effects in D. melanogaster in winter at temperate and tropical sites. Infected flies of both populations had a lower fecundity in tropical north Queensland, whilst in temperate southern Victoria Wolbachia effects depended on the nuclear population background. Here infected flies from Victoria were more fecund. Wolbachia also influenced larval/pupal viability in the tropics but this was dependent on population background. In comparisons of the populations, there was no evidence for local adaptation for total fecundity, viability or survival over winter. However, in Victoria, a local population had a higher late-life fecundity than a tropical population from Queensland that had higher early-life fecundity. At a tropical site, local Queensland flies had a higher early fecundity than Victorian flies. In contrast to many laboratory studies, mortality rates in the field cages increased only slightly over time. Both the Wolbachia effects and population differences have not been previously detected in laboratory studies with D. melanogaster and highlight the utility of Drosophila field studies in fitness experiments.}, }
@article {pmid11594465, year = {2001}, author = {Rosado-Ruiz, T and Antommattei-Pérez, FM and Cadilla, CL and López-Garriga, J}, title = {Expression and purification of recombinant hemoglobin I from Lucina pectinata.}, journal = {Journal of protein chemistry}, volume = {20}, number = {4}, pages = {311-315}, pmid = {11594465}, issn = {0277-8033}, support = {G12 RR003051/RR/NCRR NIH HHS/United States ; G12RR03051/RR/NCRR NIH HHS/United States ; S06-GM0810327/GM/NIGMS NIH HHS/United States ; S06-GM08224/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Bivalvia/*genetics ; Cloning, Molecular ; DNA, Complementary ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli/genetics ; Gene Expression ; Heme/metabolism ; *Hemoglobins ; Hemoglobins, Abnormal/*genetics/*isolation &amp; purification/metabolism ; Molecular Sequence Data ; Recombinant Proteins ; }, abstract = {Hemoglobin I (HbI) from Lucina pectinata reacts with hydrogen sulfide to form the ferric sulfide complex needed to transport H2S to the bacterial endosymbiont. To further study HbI, expression studies of this protein were performed in Escherichia coli. This is the first time that the recombinant HbI was produced using a recombinant DNA expression system. Hemoglobin I cDNA was amplified and cloned into the TOPO-PBAD expression vector, which contains a fusion tag of six histidine residues (6XHis tag). Plasmid clone sequence analysis was carried out in order to ensure that the insert was in the correct reading frame for proper protein expression in E. coli. The expression of recombinant HbI was optimal when induced for 5 hr with 0.002% of L-arabinose as detected by Western blot analysis. The proto-porphyrin group was inserted into the recombinant HbI. Purification of the heme-bound recombinant protein was performed under native conditions by affinity chromatography using Ni-NTA and Probond resins. The sodium dithionite-reduced recombinant protein presented a shift from the Soret band at 413-435 nm, indicating the presence of the heme group in the adequate amino acid environment of HbI. These results indicate that recombinant HbI from Lucina pectinata can be successfully expressed in a prokaryotic system retaining its activity toward reduction, oxidation, and ligand binding.}, }
@article {pmid11591717, year = {2002}, author = {Minic, Z and Pastra-Landis, S and Gaill, F and Hervé, G}, title = {Catabolism of pyrimidine nucleotides in the deep-sea tube worm Riftia pachyptila.}, journal = {The Journal of biological chemistry}, volume = {277}, number = {1}, pages = {127-134}, doi = {10.1074/jbc.M108035200}, pmid = {11591717}, issn = {0021-9258}, mesh = {5'-Nucleotidase/metabolism ; Animals ; Chromatography, Ion Exchange ; Cytidine Triphosphate/metabolism ; Hydrogen-Ion Concentration ; Polychaeta/*metabolism ; Pyrimidine Nucleotides/*metabolism ; Substrate Specificity ; Symbiosis ; }, abstract = {The present study describes the distribution and properties of enzymes of the catabolic pathway of pyrimidine nucleotides in Riftia pachyptila, a tubeworm living around deep-sea hydrothermal vents and known to be involved in a highly specialized symbiotic association with a bacterium. The catabolic enzymes, 5'-nucleotidase, uridine phosphorylase, and uracil reductase, are present in all tissues of the worm, whereas none of these enzymatic activities were found in the symbiotic bacteria. The 5'-nucleotidase activity was particularly high in the trophosome, the symbiont-harboring tissue. These results suggest that the production of nucleosides in the trophosome may represent an alternative source of carbon and nitrogen for R. pachyptila, because these nucleosides can be delivered to other parts of the worm. This process would complement the source of carbon and nitrogen from organic metabolites provided by the bacterial assimilatory pathways. The localization of the enzymes participating in catabolism, 5'-nucleotidase and uridine phosphorylase, and of the enzymes involved in the biosynthesis of pyrimidine nucleotides, aspartate transcarbamylase and dihydroorotase, shows a non-homogeneous distribution of these enzymes in the trophosome. The catabolic enzymes 5'-nucleotidase and uridine phosphorylase activities increase from the center of the trophosome to its periphery. In contrast, the anabolic enzymes aspartate transcarbamylase and dihydroorotase activities decrease from the center toward the periphery of the trophosome. We propose a general scheme of anatomical and physiological organization of the metabolic pathways of the pyrimidine nucleotides in R. pachyptila and its bacterial endosymbiont.}, }
@article {pmid11571178, year = {2001}, author = {Gulledge, J and Ahmad, A and Steudler, PA and Pomerantz, WJ and Cavanaugh, CM}, title = {Family- and genus-level 16S rRNA-targeted oligonucleotide probes for ecological studies of methanotrophic bacteria.}, journal = {Applied and environmental microbiology}, volume = {67}, number = {10}, pages = {4726-4733}, pmid = {11571178}, issn = {0099-2240}, mesh = {Alphaproteobacteria/classification/*genetics ; *Ecosystem ; *Environmental Microbiology ; Genes, rRNA ; Methane/metabolism ; Methylococcaceae/classification/*genetics ; Molecular Sequence Data ; Oligonucleotide Probes/*genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA ; Species Specificity ; }, abstract = {Methanotrophic bacteria play a major role in the global carbon cycle, degrade xenobiotic pollutants, and have the potential for a variety of biotechnological applications. To facilitate ecological studies of these important organisms, we developed a suite of oligonucleotide probes for quantitative analysis of methanotroph-specific 16S rRNA from environmental samples. Two probes target methanotrophs in the family Methylocystaceae (type II methanotrophs) as a group. No oligonucleotide signatures that distinguish between the two genera in this family, Methylocystis and Methylosinus, were identified. Two other probes target, as a single group, a majority of the known methanotrophs belonging to the family Methylococcaceae (type I/X methanotrophs). The remaining probes target members of individual genera of the Methylococcaceae, including Methylobacter, Methylomonas, Methylomicrobium, Methylococcus, and Methylocaldum. One of the family-level probes also covers all methanotrophic endosymbionts of marine mollusks for which 16S rRNA sequences have been published. The two known species of the newly described genus Methylosarcina gen. nov. are covered by a probe that otherwise targets only members of the closely related genus Methylomicrobium. None of the probes covers strains of the newly proposed genera Methylocella and "Methylothermus," which are polyphyletic with respect to the recognized methanotrophic families. Empirically determined midpoint dissociation temperatures were 49 to 57 degrees C for all probes. In dot blot screening against RNA from positive- and negative-control strains, the probes were specific to their intended targets. The broad coverage and high degree of specificity of this new suite of probes will provide more detailed, quantitative information about the community structure of methanotrophs in environmental samples than was previously available.}, }
@article {pmid11553234, year = {2001}, author = {Horn, M and Harzenetter, MD and Linner, T and Schmid, EN and Müller, KD and Michel, R and Wagner, M}, title = {Members of the Cytophaga-Flavobacterium-Bacteroides phylum as intracellular bacteria of acanthamoebae: proposal of 'Candidatus Amoebophilus asiaticus'.}, journal = {Environmental microbiology}, volume = {3}, number = {7}, pages = {440-449}, doi = {10.1046/j.1462-2920.2001.00210.x}, pmid = {11553234}, issn = {1462-2912}, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology/ultrastructure ; Animals ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Flavobacterium/classification ; Genes, rRNA ; Gram-Negative Bacteria/*classification/growth &amp; development/*isolation &amp; purification/ultrastructure ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Symbiosis ; }, abstract = {Three Gram-negative, rod-shaped bacteria that were found intracellularly in two environmental and one clinical Acanthamoeba sp. isolates were analysed. Two endocytobionts showing a parasitic behaviour were propagated successfully outside their amoebal host cells and were identified subsequently by comparative 16S rRNA sequence analysis as being most closely affiliated with Flavobacterium succinicans (99% 16S rRNA sequence similarity) or Flavobacterium johnsoniae (98% 16S rRNA sequence similarity). One endocytobiont could neither be cultivated outside its original Acanthamoeba host (Acanthamoeba sp. TUMSJ-321) nor transferred into other amoebae. Electron microscopy revealed that the amoebal trophozoites and cysts were almost completely filled with cells of this endosymbiont which are surrounded by a host-derived membrane. According to 16S rRNA sequence analysis, this endosymbiont could also be assigned to the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum, but was not closely affiliated to any recognized species within this phylogenetic group (less than 82% 16S rRNA sequence similarity). Identity and intracellular localization of this endosymbiont were confirmed by application of a specific fluorescently labelled 16S rRNA-targeted probe. Based on these findings, we propose classification of this obligate Acanthamoeba endosymbiont as 'Candidatus Amoebophilus asiaticus'. Comparative 18S rRNA sequence analysis of the host of 'Candidatus Amoebophilus asiaticus' revealed its membership with Acanthamoeba 18S rDNA sequence type T4 that comprises the majority of all Acanthamoeba isolates.}, }
@article {pmid11552656, year = {2001}, author = {Karadzhian, BP and Vishniakov, AE}, title = {[Comparison of two aposymbiotic ciliate clones of Climacostomum virens by their ability for reinfection].}, journal = {Tsitologiia}, volume = {43}, number = {7}, pages = {714-720}, pmid = {11552656}, issn = {0041-3771}, mesh = {Animals ; Chlorella/*parasitology ; Ciliophora/*pathogenicity/ultrastructure ; Clone Cells ; Microscopy, Electron ; Recurrence ; }, abstract = {The ability of two aposymbiotic (algae-free) subclones of the same green clone of C. virens to establish a stable symbiotic association with Chlorella sp. has been studied by light and electron microscopy. Alga-free subclone No. 1 was obtained from the original green clone by a long-term cultivation in darkness, while subclone No. 2 originated from one cell that spontaneously lost the algae and was found among normal green cells during daily inspection. For infection, algae isolated from ciliates with chlorellae of parental clone of C. virens were used. 5-10 minutes after feeding with Chlorella, specimens of both subclones show numerous algae mostly inside food vacuoles, but some rare algae (3-4 per cell) may occur in individual perialgal vacuoles. Later on, the number of symbiotic chlorellae in ciliates of subclone No. 1 increased, and a stable symbiotic association was reestablished. Unlike, in specimens of subclone No. 2 all newly ingested algae were seen digested within food vacuoles. Within 24-28 h all the ciliates investigated appeared free of algae. However, obviously stable symbiotic ciliate-algae systems in this subclone were obtained after improving the microinjection technique. Injection of algae into alga-free ciliates resulted in maintenance of intact chlorellae in these ciliates. The algae were seen to be located individually within perialgal vacuoles, being presumably protected against host lytic enzyme attack. The endosymbiont population in ciliates was established from as many as 3-5 originally injected algae. The number of symbiotic chlorellae increased steadily reaching the value equal to that in the parental clone 28-30 days after the start of experiment.}, }
@article {pmid11545272, year = {2001}, author = {Panina, EM and Vitreschak, AG and Mironov, AA and Gelfand, MS}, title = {Regulation of aromatic amino acid biosynthesis in gamma-proteobacteria.}, journal = {Journal of molecular microbiology and biotechnology}, volume = {3}, number = {4}, pages = {529-543}, pmid = {11545272}, issn = {1464-1801}, mesh = {Allosteric Regulation ; Amino Acid Sequence ; Amino Acids, Aromatic/*biosynthesis/*genetics ; Bacterial Proteins/genetics ; Base Sequence ; Biological Evolution ; DNA, Bacterial/genetics ; Gammaproteobacteria/*genetics/*metabolism ; Genes, Bacterial ; Genetic Techniques ; Molecular Sequence Data ; Nucleic Acid Conformation ; Operon ; Pseudomonas aeruginosa/genetics ; RNA, Bacterial/chemistry/genetics ; Regulon ; Sequence Homology, Amino Acid ; }, abstract = {Computational comparative techniques were applied to analysis of the aromatic amino acid regulons in gamma-proteobacteria. This resulted in characterization of the TrpR and TyrR regulons in the genomes of Yersinia pestis, Haemophilus influenzae, Vibrio cholerae and other bacteria and identification of new members of the PhhR regulon in the genome of Pseudomonas aeruginosa. Candidate attenuators were constructed for all studied genomes, including the trpBA operon of the very distantly related bacterium Chlamidia trachomatis. The pheA attenuator of Y. pestis is an integration site for the insertion element IS-200. It was shown that the triplication of the DAHP-synthase genes occurred prior to the divergence of families Enterobacteriaceae, Vibrionaceae and Alteromonadaceae. The candidate allosteric control site of the DAHP-syntheases was identified. This site is deteriorated in AroH of Buchnera sp. APS. The known DAHP-synthase of Bordetella pertussis is likely to be feedback-inhibited by phenylalanine, and the DAHP-synthase of Corynebacterium glutamicum could be inhibited by tyrosine. Overall, the most extensive regulation was observed in Escherichia coli, whereas the regulation in other genomes seems to be less developed. At the extreme, the tryptophan production in the aphid endosymbiont Buchnera sp. APS is free from transcriptional, attenuation, and allosteric control.}, }
@article {pmid11532218, year = {2001}, author = {Gilson, PR}, title = {Nucleomorph genomes: much ado about practically nothing.}, journal = {Genome biology}, volume = {2}, number = {8}, pages = {REVIEWS1022}, pmid = {11532218}, issn = {1474-760X}, mesh = {Animals ; Chlorophyta/cytology/*genetics ; Chromosomes/genetics ; DNA, Chloroplast/genetics ; Eukaryotic Cells/*cytology/*metabolism ; *Evolution, Molecular ; *Genome ; Introns/genetics ; Sequence Deletion/genetics ; Symbiosis/*genetics ; }, abstract = {The DNA sequence of one of the smallest eukaryotic genomes has recently been finished - that of the reduced nucleus, or nucleomorph, of an algal endosymbiont that resides within a cryptomonad host cell. Its sequence promises insights into chloroplast acquisition, the constraints on genome size and the basic workings of eukaryotic cells.}, }
@article {pmid11527469, year = {2001}, author = {Martinez-Torres, D and Buades, C and Latorre, A and Moya, A}, title = {Molecular systematics of aphids and their primary endosymbionts.}, journal = {Molecular phylogenetics and evolution}, volume = {20}, number = {3}, pages = {437-449}, doi = {10.1006/mpev.2001.0983}, pmid = {11527469}, issn = {1055-7903}, mesh = {Animals ; Aphids/classification/*genetics/microbiology ; Buchnera/*genetics ; DNA/chemistry/genetics ; DNA, Bacterial/chemistry/genetics ; Evolution, Molecular ; Genes, Bacterial/genetics ; Genes, Insect/genetics ; Molecular Sequence Data ; *Phylogeny ; Proton-Translocating ATPases/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Aphids constitute a monophyletic group within the order Homoptera (i.e., superfamily Aphidoidea). The Aphidoidea originated in the Jurassic about 150 my ago from some aphidiform ancestor whose origin can be traced back to about 250 my ago. They exhibit a mutualistic association with intracellular bacteria (Buchnera sp.) related to Escherichia coli. Buchnera is usually considered the aphids' primary endosymbiont. The association is obligate for both partners. The 16S rDNA-based phylogeny of Buchnera from four aphid families showed complete concordance with the morphology-based phylogeny of their aphid hosts, which pointed to a single original infection in a common ancestor of aphids some 100-250 my ago followed by cospeciation of aphids and Buchnera. This study concentrated on the molecular phylogeny of both the aphids and their primary endosymbionts of five aphid families including for the first time representatives of the family Lachnidae. We discuss results based on two Buchnera genes (16S rDNA and the beta subunit of the F-ATPase complex) and on one host mitochondrial gene (the subunit 6 of the F-ATPase complex). Although our data do not allow definitive evolutionary relationships to be established among the different aphid families, some traditionally accepted groupings are put into question from both bacterial and insect data. In particular, the Lachnidae and the Aphididae, which from morphological data are considered recently evolved sister groups, do not seem to be as closely related as is usually accepted. Finally, we discuss our results in the light of the proposed parallel evolution of aphids and their endosymbionts.}, }
@article {pmid11526220, year = {2001}, author = {Keeling, PJ and Palmer, JD}, title = {Lateral transfer at the gene and subgenic levels in the evolution of eukaryotic enolase.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {19}, pages = {10745-10750}, pmid = {11526220}, issn = {0027-8424}, support = {R01 GM035087/GM/NIGMS NIH HHS/United States ; R01 GM35087/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Arabidopsis ; Eukaryotic Cells ; *Evolution, Molecular ; *Gene Transfer, Horizontal ; Humans ; Molecular Sequence Data ; Phosphopyruvate Hydratase/*genetics ; Phylogeny ; }, abstract = {Enolase genes from land plants and apicomplexa (intracellular parasites, including the malarial parasite, Plasmodium) share two short insertions. This observation has led to the suggestion that the apicomplexan enolase is the product of a lateral transfer event involving the algal endosymbiont from which the apicomplexan plastid is derived. We have examined enolases from a wide variety of algae, as well as ciliates (close relatives of apicomplexa), to determine whether lateral transfer can account for the origin of the apicomplexan enolase. We find that lateral gene transfer, likely occurring intracellularly between endosymbiont and host nucleus, does account for the evolution of cryptomonad and chlorarachniophyte algal enolases but fails to explain the apicomplexan enolase. This failure is because the phylogenetic distribution of the insertions--which we find in apicomplexa, ciliates, land plants, and charophyte green algae--directly conflicts with the phylogeny of the gene itself. Protein insertions have traditionally been treated as reliable markers of evolutionary events; however, these enolase insertions do not seem to reflect accurately the evolutionary history of the molecule. The lack of congruence between insertions and phylogeny could be because of the parallel loss of both insertions in two or more lineages, or what is more likely, because the insertions were transmitted between distantly related genes by lateral transfer and fine-scale recombination, resulting in a mosaic gene. This latter process would be difficult to detect without such insertions to act as markers, and such mosaic genes could blur the "tree of life" beyond the extent to which whole-gene lateral transfer is already known to confound evolutionary reconstruction.}, }
@article {pmid11523007, year = {2001}, author = {Saldarriaga, JF and Taylor, FJ and Keeling, PJ and Cavalier-Smith, T}, title = {Dinoflagellate nuclear SSU rRNA phylogeny suggests multiple plastid losses and replacements.}, journal = {Journal of molecular evolution}, volume = {53}, number = {3}, pages = {204-213}, doi = {10.1007/s002390010210}, pmid = {11523007}, issn = {0022-2844}, mesh = {Animals ; Cell Nucleus/*genetics ; Dinoflagellida/*cytology/*genetics ; Endocytosis ; *Evolution, Molecular ; Models, Biological ; Photosynthesis ; Phylogeny ; Plastids/*genetics/*physiology ; RNA, Ribosomal/*genetics ; RNA, Ribosomal, 18S/genetics ; Ribosomes/genetics ; Symbiosis ; }, abstract = {Dinoflagellates are a trophically diverse group of protists with photosynthetic and non-photosynthetic members that appears to incorporate and lose endosymbionts relatively easily. To trace the gain and loss of plastids in dinoflagellates, we have sequenced the nuclear small subunit rRNA gene of 28 photosynthetic and four non-photosynthetic species, and produced phylogenetic trees with a total of 81 dinoflagellate sequences. Patterns of plastid gain, loss, and replacement were plotted onto this phylogeny. With the exception of the apparently early-diverging Syndiniales and Noctilucales, all non-photosynthetic dinoflagellates are very likely to have had photosynthetic ancestors with peridinin-containing plastids. The same is true for all dinoflagellates with plastids other than the peridinin-containing plastid: their ancestors have replaced one type of plastid for another, in some cases most likely through a non-photosynthetic intermediate. Eight independent instances of plastid loss and three of replacement can be inferred from existing data, but as more non-photosynthetic lineages are characterized these numbers will surely grow.}, }
@article {pmid11508688, year = {2001}, author = {Emelyanov, VV}, title = {Rickettsiaceae, rickettsia-like endosymbionts, and the origin of mitochondria.}, journal = {Bioscience reports}, volume = {21}, number = {1}, pages = {1-17}, doi = {10.1023/a:1010409415723}, pmid = {11508688}, issn = {0144-8463}, mesh = {Animals ; Bacteria/cytology/genetics/metabolism ; Chaperonin 60/genetics/metabolism ; Energy Metabolism/genetics ; Eukaryotic Cells/*cytology/metabolism ; Humans ; Mitochondria/genetics/metabolism/*ultrastructure ; *Phylogeny ; Rickettsiaceae/*cytology/genetics/metabolism ; Symbiosis/*genetics ; }, abstract = {Accumulating evolutionary data point to a monophyletic origin of mitochondria from the order Rickettsiales. This large group of obligate intracellular alpha-Proteobacteria includes the family Rickettsiaceae and several rickettsia-like endosymbionts (RLEs). Detailed phylogenetic analysis of small subunit (SSU) rRNA and chaperonin 60 (Cpn60) sequences testify to polyphyly of the Rickettsiales, and consistently indicate a sisterhood of Rickettsiaceae and mitochondria that excludes RLEs. Thus RLEs are considered as the nearest extant relatives of an extinct last common ancestor of mitochondria and rickettsiae. Phylogenetic inferences prompt the following assumptions. (1) Mitochondrial origin has been predisposed by the long-term endosymbiotic relationship between rickettsia-like bacteria and proto-eukaryotes, in which many endosymbiont genes have been lost while some indispensable genes have been transferred to the host genome. (2) The obligate dependence of rickettsiae upon a eukaryotic host rests on the import of proteins encoded by these transferred genes. The nature of a proto-eukaryotic cell still remains elusive. The divergence of Rickettsiaceae and mitochondria based on Cpn60, and the evolutionary history of two aminoacyl-tRNA synthetases favor the hypothesis that it was a chimera created by fusion of an archaebacterium and a eubacterium not long before an endosymbiotic event. These and other, mostly biochemical data suggest that all the mitochondrion-related organelles, i.e., both aerobically and anaerobically respiring mitochondria and hydrogenosomes, have originated from the same RLE, while hydrogenosomal energy metabolism may have a separate origin resulting from a eubacterial fusion partner.}, }
@article {pmid11506910, year = {2001}, author = {d'Avila-Levy, CM and Melo, AC and Vermelho, AB and Branquinha, MH}, title = {Differential expression of proteolytic enzymes in endosymbiont-harboring Crithidia species.}, journal = {FEMS microbiology letters}, volume = {202}, number = {1}, pages = {73-77}, doi = {10.1111/j.1574-6968.2001.tb10782.x}, pmid = {11506910}, issn = {0378-1097}, mesh = {Animals ; Bacteria/isolation &amp; purification ; Crithidia/cytology/*enzymology/genetics/*microbiology ; Cysteine Endopeptidases/genetics/metabolism ; Electrophoresis, Polyacrylamide Gel ; *Endocytosis ; Isoenzymes/chemistry/genetics/metabolism ; Metalloendopeptidases/chemistry/genetics/metabolism ; Molecular Weight ; Symbiosis/*physiology ; }, abstract = {Crithidia oncopelti, Crithidia deanei and Crithidia desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Gelatin-SDS-PAGE analysis was used to characterize cell-associated and extracellular proteinases in these organisms. Our survey indicates that the proteolytic profiles of C. deanei and C. desouzai are identical; that C. oncopelti displays a distinct zymogram; and that species naturally lacking endosymbionts have a more complex extracellular proteolytic activity, which illustrates the heterogeneity of this genus. This is the first report on the presence of cysteine proteinases in the culture supernatant of monoxenic trypanosomatids, and by the use of wild and aposymbiotic strains from C. deanei we also demonstrated that the prokaryote endosymbiont somehow alters quantitatively the expression of extracellular proteinases in this trypanosomatid.}, }
@article {pmid11488969, year = {2001}, author = {Moret, Y and Juchault, P and Rigaud, T}, title = {Wolbachia endosymbiont responsible for cytoplasmic incompatibility in a terrestrial crustacean: effects in natural and foreign hosts.}, journal = {Heredity}, volume = {86}, number = {Pt 3}, pages = {325-332}, doi = {10.1046/j.1365-2540.2001.00831.x}, pmid = {11488969}, issn = {0018-067X}, mesh = {Animals ; Crosses, Genetic ; Crustacea/*microbiology/*physiology ; Cytoplasm/physiology ; Embryonic Development ; Female ; Male ; Mitosis ; Reproduction ; Sexual Behavior, Animal ; *Symbiosis ; Wolbachia/*physiology ; }, abstract = {Wolbachia bacteria are vertically transmitted endosymbionts that disturb the reproduction of many arthropods thereby enhancing their spread in host populations. Wolbachia are often responsible for changes of sex ratios in terrestrial isopods, a result of the feminization of genotypic males. Here we found that the Wolbachia hosted by Cylisticus convexus (wCc) caused unidirectional cytoplasmic incompatibility (CI), an effect commonly found in insects. To understand the diversity of Wolbachia-induced effects in isopods, wCc were experimentally transferred in a novel isopod host, Armadillidium vulgare. wCc conserved the ability to induce CI. However, Wolbachia were not transmitted to the eggs, so the capacity to restore the compatibility in crosses involving two transinfected individuals was lost. The feminizing Wolbachia hosted by A. vulgare was unable to rescue CI induced by wCc. These results showed that Wolbachia in isopods did not evolved broadly to induce feminization, and that CI and the feminizing effect are probably due to different mechanisms. In addition, wCc reduces the mating capacity of infected C. convexus males, suggesting that the bacteria might alter reproductive behaviour. The maintenance of wCc in host populations is discussed.}, }
@article {pmid11481431, year = {2001}, author = {Finan, TM and Weidner, S and Wong, K and Buhrmester, J and Chain, P and Vorhölter, FJ and Hernandez-Lucas, I and Becker, A and Cowie, A and Gouzy, J and Golding, B and Pühler, A}, title = {The complete sequence of the 1,683-kb pSymB megaplasmid from the N2-fixing endosymbiont Sinorhizobium meliloti.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {17}, pages = {9889-9894}, pmid = {11481431}, issn = {0027-8424}, mesh = {Bacterial Proteins/genetics/physiology ; Carbohydrate Metabolism ; Carrier Proteins/genetics ; Chaperonins/genetics ; DNA, Bacterial/genetics ; Drug Resistance, Microbial/genetics ; Enzymes/genetics ; Gene Expression Regulation, Bacterial ; Gene Library ; Genes, Bacterial ; Lipopolysaccharides/biosynthesis ; Molecular Sequence Data ; Nitrogen Fixation/genetics ; Plasmids/*genetics ; RNA, Transfer, Arg/genetics ; Replication Origin/genetics ; Replicon/genetics ; Sequence Analysis, DNA ; Sinorhizobium meliloti/*genetics ; Species Specificity ; Transcription, Genetic/genetics ; }, abstract = {Analysis of the 1,683,333-nt sequence of the pSymB megaplasmid from the symbiotic N(2)-fixing bacterium Sinorhizobium meliloti revealed that the replicon has a high gene density with a total of 1,570 protein-coding regions, with few insertion elements and regions duplicated elsewhere in the genome. The only copies of an essential arg-tRNA gene and the minCDE genes are located on pSymB. Almost 20% of the pSymB sequence carries genes encoding solute uptake systems, most of which were of the ATP-binding cassette family. Many previously unsuspected genes involved in polysaccharide biosynthesis were identified and these, together with the two known distinct exopolysaccharide synthesis gene clusters, show that 14% of the pSymB sequence is dedicated to polysaccharide synthesis. Other recognizable gene clusters include many involved in catabolic activities such as protocatechuate utilization and phosphonate degradation. The functions of these genes are consistent with the notion that pSymB plays a major role in the saprophytic competence of the bacteria in the soil environment.}, }
@article {pmid11476638, year = {2001}, author = {Cameron, SL and Adlard, RD and O'Donoghue, PJ}, title = {Evidence for an independent radiation of endosymbiotic litostome ciliates within Australian marsupial herbivores.}, journal = {Molecular phylogenetics and evolution}, volume = {20}, number = {2}, pages = {302-310}, doi = {10.1006/mpev.2001.0986}, pmid = {11476638}, issn = {1055-7903}, mesh = {Animals ; Ciliophora/classification/*genetics ; DNA, Protozoan/chemistry/genetics ; Evolution, Molecular ; Marsupialia/*parasitology ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {The recent discovery of isotrichid-like ciliates occurring as endosymbionts in macropodid marsupials posed interesting questions in regard to both their phyletic origin (all previous records confined to eutherian mammals) and their morphological evolution (Australian forms possibly representing missing links between previously described genera). The SSU rRNA gene was sequenced for three species (Dasytricha dehorityi, D. dogieli, and Bitricha tasmaniensis) and aligned against representatives of all major ciliate classes. The Australian species did not group with the other isotrichid species but instead formed an independent radiation. Discrepancies between recent global phylogenies of the phylum Ciliophora were examined by manipulation of the aligned sequence data set. Sources of conflict between these studies did not stem from differences in outgroup choice or phylogenetic reconstruction methods. Differences in the application of confidence limits and primary sequence alignment have probably resulted in the reporting of spurious associations which are not supported by more conservative confidence or alignment methodology. At present, the ciliate subphylum Intramacronucleata is an unresolved polytomy which may be due to deficiencies in the SSU rRNA gene sequence dataset or indicate that the ciliates radiated into their extant classes by rapid burst-like evolution.}, }
@article {pmid11473316, year = {2001}, author = {von Dohlen, CD and Kohler, S and Alsop, ST and McManus, WR}, title = {Mealybug beta-proteobacterial endosymbionts contain gamma-proteobacterial symbionts.}, journal = {Nature}, volume = {412}, number = {6845}, pages = {433-436}, doi = {10.1038/35086563}, pmid = {11473316}, issn = {0028-0836}, mesh = {Animals ; Betaproteobacteria/*physiology/ultrastructure ; Female ; Gammaproteobacteria/*physiology/ultrastructure ; Hemiptera/*microbiology/ultrastructure ; Polymerase Chain Reaction ; *Symbiosis ; }, abstract = {Some insects have cultivated intimate relationships with mutualistic bacteria since their early evolutionary history. Most ancient 'primary' endosymbionts live within the cytoplasm of large, polyploid host cells of a specialized organ (bacteriome). Within their large, ovoid bacteriomes, mealybugs (Pseudococcidae) package the intracellular endosymbionts into 'mucus-filled' spheres, which surround the host cell nucleus and occupy most of the cytoplasm. The genesis of symbiotic spheres has not been determined, and they are structurally unlike eukaryotic cell vesicles. Recent molecular phylogenetic and fluorescent in situ hybridization (FISH) studies suggested that two unrelated bacterial species may share individual host cells, and that bacteria within spheres comprise these two species. Here we show that mealybug host cells do indeed harbour both beta- and gamma-subdivision Proteobacteria, but they are not co-inhabitants of the spheres. Rather, we show that the symbiotic spheres themselves are beta-proteobacterial cells. Thus, gamma-Proteobacteria live symbiotically inside beta-Proteobacteria. This is the first report, to our knowledge, of an intracellular symbiosis involving two species of bacteria.}, }
@article {pmid11470849, year = {2001}, author = {Gerbod, D and Edgcomb, VP and Noël, C and Vanácová, S and Wintjens, R and Tachezy, J and Sogin, ML and Viscogliosi, E}, title = {Phylogenetic relationships of class II fumarase genes from trichomonad species.}, journal = {Molecular biology and evolution}, volume = {18}, number = {8}, pages = {1574-1584}, doi = {10.1093/oxfordjournals.molbev.a003944}, pmid = {11470849}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Animals ; DNA, Protozoan/chemistry/genetics ; Evolution, Molecular ; Fumarate Hydratase/*genetics ; Gene Expression Regulation, Enzymologic ; Molecular Sequence Data ; *Phylogeny ; RNA, Protozoan/genetics/metabolism ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Trichomonadida/classification/enzymology/*genetics ; }, abstract = {Class II fumarase sequences were obtained by polymerase chain reaction from five trichomonad species. All residues known to be highly conserved in this enzyme were present. Nuclear run-on assays showed that one of the two genes identified in Tritrichomonas foetus was expressed, whereas no fumarase transcripts were detected in the related species Trichomonas vaginalis. These findings corroborate previous biochemical data. Fumarase genes were also expressed in Monocercomonas sp. and Tetratrichomonas gallinarum but not in Pentatrichomonas hominis, Trichomonas gallinae, Trichomonas tenax, and Trichomitus batrachorum under the culture conditions used. Molecular trees inferred by likelihood methods reveal that trichomonad sequences have no affinity to described class II fumarase genes from other eukaryotes. The absence of functional mitochondria in protists such as trichomonads suggests that they diverged from other eukaryotes prior to the alpha-proteobacterial symbiosis that led to mitochondria. Furthermore, they are basal to other eukaryotes in rRNA analyses. However, support for the early-branching status of trichomonads and other amitochondriate protists based on phylogenetic analyses of multiple data sets has been equivocal. Although the presence of hydrogenosomes suggests that trichomonads once had mitochondria, their class II iron-independent fumarase sequences differ markedly from those of other mitochondriate eukaryotes. All of the class II fumarase genes described from other eukaryotes are of apparent alpha-proteobacterial origin and hence a marker of mitochondrial evolution. In contrast, the class II fumarase from trichomonads emerges among other eubacterial homologs. This is intriguing evidence for an independent acquisition of these genes in trichomonads apart from the mitochondrial endosymbiosis event that gave rise to the form present in other eukaryotes. The ancestral trichomonad class II fumarase may represent a prokaryotic form that was replaced in other eukaryotes after the divergence of trichomonads with the movement of endosymbiont genes into the nucleus. Alternatively, it may have been acquired via a separate endosymbiotic event or lateral gene transfer.}, }
@article {pmid11463468, year = {2001}, author = {Kawazu, S and Komaki, K and Tsuji, N and Kawai, S and Ikenoue, N and Hatabu, T and Ishikawa, H and Matsumoto, Y and Himeno, K and Kano, S}, title = {Molecular characterization of a 2-Cys peroxiredoxin from the human malaria parasite Plasmodium falciparum.}, journal = {Molecular and biochemical parasitology}, volume = {116}, number = {1}, pages = {73-79}, doi = {10.1016/s0166-6851(01)00308-5}, pmid = {11463468}, issn = {0166-6851}, mesh = {Amino Acid Sequence ; Animals ; Antioxidants ; Cloning, Molecular ; Molecular Sequence Data ; Peroxidases/*genetics ; Peroxiredoxin VI ; Peroxiredoxins ; Plasmodium falciparum/enzymology/*genetics/pathogenicity ; Protozoan Proteins/genetics ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; }, abstract = {We have identified the 2-Cys peroxiredoxin (PfPrx-1) from the human malaria parasite Plasmodium falciparum. The PfPrx-1 showed the highest identity at amino acid level to the type II Prx among the currently known six subfamilies of mammalian Prx. The sequence identity between the PfPrx-1 and the previously reported 1-Cys Prx of P. falciparum (PfPrx-2), which corresponded to mammalian type VI Prx, was 25%. This suggests that the parasite possesses two Prx subfamilies. The PfPrx-1 showed significant sequence similarities with those of 2-Cys peroxiredoxins of plants in the BLASTX search. This may reflect the consequences of a genetic transfer from an algal endosymbiont to the parasite nucleus during evolution. The recombinant PfPrx-1 protein (rPfPrx-1) was expressed as a histidine fusion protein in Escherichia coli and purified with Ni chromatography. The rPfPrx-1 existed as dimers under non-reducing conditions and dissociated into monomers in the presence of dithiothreitol. The PfPrx-1 protein also exists as a dimer in the parasites themselves. The reduction of the oxidized enzyme by the donation of electrons from E. coli thioredoxin (Trx)/Trx reductase system was demonstrated in its reaction with H(2)O(2), using the rPfPrx-1 protein. These results suggested that the PfPrx-1 can act as a terminal peroxidase of the parasite Trx system. An elevated expression of the PfPrx-1 protein seen in the trophozoite, the stage with active metabolism, suggests an association of the parasite Trx system with its intracellular redox control.}, }
@article {pmid11457448, year = {2001}, author = {Emelyanov, VV}, title = {Evolutionary relationship of Rickettsiae and mitochondria.}, journal = {FEBS letters}, volume = {501}, number = {1}, pages = {11-18}, doi = {10.1016/s0014-5793(01)02618-7}, pmid = {11457448}, issn = {0014-5793}, mesh = {Energy Metabolism ; Genome ; Mitochondria/genetics/metabolism/*physiology ; *Models, Biological ; *Phylogeny ; Rickettsia/classification/genetics/*physiology ; Symbiosis ; }, abstract = {Phylogenetic data support an origin of mitochondria from the alpha-proteobacterial order Rickettsiales. This high-rank taxon comprises exceptionally obligate intracellular endosymbionts of eukaryotic cells, and includes family Rickettsiaceae and a group of microorganisms termed Rickettsia-like endosymbionts (RLEs). Most detailed phylogenetic analyses of small subunit rRNA and chaperonin 60 sequences consistently show the RLEs to have emerged before Rickettsiaceae and mitochondria sister clades. These data suggest that the origin of mitochondria and Rickettsiae has been preceded by the long-term mutualistic relationship of an intracellular bacterium with a pro-eukaryote, in which an invader has lost many dispensable genes, yet evolved carrier proteins to exchange respiration-derived ATP for host metabolites as envisaged in classic endosymbiont theory.}, }
@article {pmid11443086, year = {2001}, author = {Akman, L and Rio, RV and Beard, CB and Aksoy, S}, title = {Genome size determination and coding capacity of Sodalis glossinidius, an enteric symbiont of tsetse flies, as revealed by hybridization to Escherichia coli gene arrays.}, journal = {Journal of bacteriology}, volume = {183}, number = {15}, pages = {4517-4525}, pmid = {11443086}, issn = {0021-9193}, support = {AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; DNA Methylation ; DNA, Bacterial ; Enterobacteriaceae/*genetics ; Escherichia coli/genetics ; *Genome, Bacterial ; Molecular Sequence Data ; Nucleic Acid Hybridization ; Plasmids ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Recent molecular characterization of various microbial genomes has revealed differences in genome size and coding capacity between obligate symbionts and intracellular pathogens versus free-living organisms. Multiple symbiotic microorganisms have evolved with tsetse fly, the vector of African trypanosomes, over long evolutionary times. Although these symbionts are indispensable for tsetse fecundity, the biochemical and molecular basis of their functional significance is unknown. Here, we report on the genomic aspects of the secondary symbiont Sodalis glossinidius. The genome size of Sodalis is approximately 2 Mb. Its DNA is subject to extensive methylation and based on some of its conserved gene sequences has an A+T content of only 45%, compared to the typically AT-rich genomes of endosymbionts. Sodalis also harbors an extrachromosomal plasmid about 134 kb in size. We used a novel approach to gain insight into Sodalis genomic contents, i.e., hybridizing its DNA to macroarrays developed for Escherichia coli, a closely related enteric bacterium. In this analysis we detected 1,800 orthologous genes, corresponding to about 85% of the Sodalis genome. The Sodalis genome has apparently retained its genes for DNA replication, transcription, translation, transport, and the biosynthesis of amino acids, nucleic acids, vitamins, and cofactors. However, many genes involved in energy metabolism and carbon compound assimilation are apparently missing, which may indicate an adaptation to the energy sources available in the only nutrient of the tsetse host, blood. We present gene arrays as a rapid tool for comparative genomics in the absence of whole genome sequence to advance our understanding of closely related bacteria.}, }
@article {pmid11429143, year = {2001}, author = {Viola, R and Nyvall, P and Pedersén, M}, title = {The unique features of starch metabolism in red algae.}, journal = {Proceedings. Biological sciences}, volume = {268}, number = {1474}, pages = {1417-1422}, doi = {10.1098/rspb.2001.1644}, pmid = {11429143}, issn = {0962-8452}, mesh = {Photosynthesis ; Rhodophyta/*metabolism ; Starch/*metabolism ; }, abstract = {Red algae (Rhodophyceae) are photosynthetic eukaryotes that accumulate starch granules outside of their plastids. The starch granules from red algae (floridean starch) show structural similarities with higher plant starch granules but lack amylose. Recent studies have indicated that the extra-plastidic starch synthesis in red algae proceeds via a UDP glucose-selective alpha-glucan synthase, in analogy with the cytosolic pathway of glycogen synthesis in other eukaryotes. On the other hand, plastidic starch synthesis in green cells occurs selectively via ADP glucose in analogy with the pathway of glycogen synthesis in prokaryotes from which plastids have evolved. Given the emerging consensus of a monophyletic origin of plastids, it would appear that the capacity for starch synthesis selectively evolved from the alpha-glucan synthesizing machinery of the host ancestor and its endosymbiont in red algae and green algae, respectively. This implies the evolution of fundamentally different functional relationships between the different subcellular compartments with regard to photosynthetic carbon metabolism in these organisms. It is suggested that the biochemical and molecular elucidation of floridean starch synthesis may offer new insights into the metabolic strategies of photosynthetic eukaryotes.}, }
@article {pmid11411846, year = {2001}, author = {Pawlowski, J and Holzmann, M and Fahrni, JF and Pochon, X and Lee, JJ}, title = {Molecular identification of algal endosymbionts in large miliolid Foraminifera: 2. Dinofiagellates.}, journal = {The Journal of eukaryotic microbiology}, volume = {48}, number = {3}, pages = {368-373}, doi = {10.1111/j.1550-7408.2001.tb00326.x}, pmid = {11411846}, issn = {1066-5234}, support = {GMS 08168/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Chlorophyta/chemistry/classification/*genetics ; Cluster Analysis ; DNA, Protozoan/chemistry/*genetics/isolation &amp; purification ; DNA, Ribosomal/chemistry/genetics ; Dinoflagellida/chemistry/classification/*genetics ; Eukaryota/*microbiology ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction ; Sequence Homology, Nucleic Acid ; Symbiosis/genetics ; }, abstract = {Large miliolid foraminifers of the subfamily Soritinae bear symbiotic dinoflagellates morphologically similar to the species of the "Symbiodinium" complex, commonly found in corals and other marine invertebrates. Soritid foraminifers are abundant in coral reefs and it has been proposed that they share their symbionts with other dinoflagellate-bearing reef dwellers. In order to test this hypothesis, we have analysed partial large subunit ribosomal DNA sequences from dinoflagellates symbionts obtained from 28 foraminiferal specimens, and compared them to the corresponding sequences of Symbiodinium-like endosymbionts from various groups of invertebrates. Phylogenetic analysis of our data shows that all soritid symbionts belong to the "Symbiodinium" species complex, within which they form seven different molecular types (Frl-Fr7). Only one of these types (Fr1) branches within a group of invertebrate symbionts, previously described as type C. The remaining six types form sister groups to coral symbionts previously designed as types B, C, and D. Our data indicate a high genetic diversity and specificity of Symbiodinium-like symbionts in soritids. Except for type C, we have found no evidence for the transmission of symbionts between foraminifers and other symbiont-bearing invertebrates from the same localities. However, exchanges must have occurred frequently between the different species of Soritinae, as suggested by the lack of host specificity and some biogeographical patterns observed in symbiont distribution. Our data suggest that members of the subfamily Soritinae acquired their symbionts at least three times during their history, each acquisition being followed by a rapid diversification and independent radiation of symbionts within the foraminiferal hosts.}, }
@article {pmid11411845, year = {2001}, author = {Pawlowski, J and Holzmann, M and Fahrni, JF and Hallock, P}, title = {Molecular identification of algal endosymbionts in large miliolid foraminifera: 1. Chlorophytes.}, journal = {The Journal of eukaryotic microbiology}, volume = {48}, number = {3}, pages = {362-367}, doi = {10.1111/j.1550-7408.2001.tb00325.x}, pmid = {11411845}, issn = {1066-5234}, mesh = {Animals ; Base Sequence ; Chlamydomonas/chemistry/classification/*genetics ; Chlorophyta/chemistry/classification/*genetics ; DNA, Protozoan/chemistry/*genetics/isolation &amp; purification ; DNA, Ribosomal Spacer/chemistry/genetics ; Eukaryota/*microbiology ; Molecular Sequence Data ; *Phylogeny ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {Large miliolid foraminifers bear various types of algal endosymbionts including chlorophytes, dinoflagellates, rhodophytes, and diatoms. Symbiosis plays a key role in the adaptation of large foraminifera to survival and growth in oligotrophic seas. The identity and diversity of foraminiferal symbionts, however, remain largely unknown. In the present work we use ribosomal DNA (rDNA) sequences to identify chlorophyte endosymbionts in large miliolid foraminifera of the superfamily Soritacea. Partial 18S and complete Internal Transcribed Spacer (ITS) rDNA sequences were obtained from symbionts of eight species representing all genera of extant chlorophyte-bearing Soritacea. Phylogenetic analysis of the sequences confirms the previous fine structure-based identification of these endosymbionts as belonging to the genus Chlamydomonas. All foraminiferal symbionts form a monophyletic group closely related to Chlamydomonas noctigama. The group is composed of seven types identified in this study, including one previously morphologically described species, Chlamydomonas hedleyi. Each of these types can be considered as a separate species, based on the comparison of genetic differences observed between other established Chlamydomonas species. Several foraminiferal species share the same symbiont type, but only one species, Archaias angulatus, was found to bear more than one type.}, }
@article {pmid11411291, year = {2001}, author = {Charles, H and Heddi, A and Rahbe, Y}, title = {A putative insect intracellular endosymbiont stem clade, within the Enterobacteriaceae, infered from phylogenetic analysis based on a heterogeneous model of DNA evolution.}, journal = {Comptes rendus de l'Academie des sciences. Serie III, Sciences de la vie}, volume = {324}, number = {5}, pages = {489-494}, doi = {10.1016/s0764-4469(01)01328-2}, pmid = {11411291}, issn = {0764-4469}, mesh = {Animals ; DNA/*analysis ; *Enterobacteriaceae/genetics/growth &amp; development ; *Evolution, Molecular ; Insecta/genetics/*microbiology ; *Phylogeny ; *Symbiosis ; }, abstract = {Insect intracellular symbiotic bacteria (intracellular endosymbionts, or endocytobionts) were positioned within the gamma 3-Proteobacteria using a non-homogeneous model of DNA evolution, allowing for rate variability among sites, for GC content heterogeneity among sequences, and applied to a maximum likelihood framework. Most of them were found to be closely related within the Enterobacteriaceae family, located between Proteus and Yersinia. These results suggest that such a bacterial group might possess several traits allowing for insect infection and the stable establishment of symbiotic relationships and that this could represent a stem clade for numerous insect endocytobionts. Based on the estimations of the equilibrium GC content and branch lengths in the phylogenetic tree, we have made comparisons of the relative ages of these different symbioses.}, }
@article {pmid11404467, year = {2001}, author = {Akman, L and Aksoy, S}, title = {A novel application of gene arrays: Escherichia coli array provides insight into the biology of the obligate endosymbiont of tsetse flies.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {13}, pages = {7546-7551}, pmid = {11404467}, issn = {0027-8424}, support = {AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/genetics ; DNA Methylation ; DNA Replication ; DNA, Bacterial/genetics ; DNA, Complementary ; Enterobacteriaceae/*genetics/physiology ; Escherichia coli/*genetics ; Genome, Bacterial ; Molecular Sequence Data ; Nucleic Acid Hybridization ; Oligonucleotide Array Sequence Analysis/methods ; Protein Biosynthesis ; Symbiosis ; Transcription, Genetic ; Tsetse Flies/*microbiology ; }, abstract = {Symbiotic associations with microorganisms are pivotal in many insects. Yet, the functional roles of obligate symbionts have been difficult to study because it has not been possible to cultivate these organisms in vitro. The medically important tsetse fly (Diptera: Glossinidae) relies on its obligate endosymbiont, Wigglesworthia glossinidia, a member of the Enterobacteriaceae, closely related to Escherichia coli, for fertility and possibly nutrition. We show here that the intracellular Wigglesworthia has a reduced genome size smaller than 770 kb. In an attempt to understand the composition of its genome, we used the gene arrays developed for E. coli. We were able to identify 650 orthologous genes in Wigglesworthia corresponding to approximately 85% of its genome. The arrays were also applied for expression analysis using Wigglesworthia cDNA and 61 gene products were detected, presumably coding for some of its most abundant products. Overall, genes involved in cell processes, DNA replication, transcription, and translation were found largely retained in the small genome of Wigglesworthia. In addition, genes coding for transport proteins, chaperones, biosynthesis of cofactors, and some amino acids were found to comprise a significant portion, suggesting an important role for these proteins in its symbiotic life. Based on its expression profile, we predict that Wigglesworthia may be a facultative anaerobic organism that utilizes ammonia as its major source of nitrogen. We present an application of E. coli gene arrays to obtain broad genome information for a closely related organism in the absence of complete genome sequence data.}, }
@article {pmid11384164, year = {2001}, author = {Pfarr, KM and Qazi, S and Fuhrman, JA}, title = {Nitric oxide synthase in filariae: demonstration of nitric oxide production by embryos in Brugia malayi and Acanthocheilonema viteae.}, journal = {Experimental parasitology}, volume = {97}, number = {4}, pages = {205-214}, doi = {10.1006/expr.2001.4613}, pmid = {11384164}, issn = {0014-4894}, support = {AI 02642/AI/NIAID NIH HHS/United States ; AI 33395/AI/NIAID NIH HHS/United States ; NS30566/NS/NINDS NIH HHS/United States ; }, mesh = {Animals ; Brugia malayi/embryology/*enzymology ; Dipetalonema/embryology/*enzymology ; Female ; Gerbillinae ; Immunohistochemistry ; Male ; Nitric Oxide/*biosynthesis ; Nitric Oxide Synthase/isolation &amp; purification/*metabolism ; }, abstract = {The radical gas nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) from l-arginine and molecular oxygen. Nitric oxide is an important signaling molecule in invertebrate and vertebrate systems. Previously we have shown that NOS is localized to more tissues in Brugia malayi than has been reported in Ascaris suum. In this paper, we analyze the distribution of NOS in Acanthocheilonema viteae, a filarial nematode that differs from B. malayi in that A. viteae females release microfilariae without a sheath. A. viteae is also one of a few filarial parasites without the Wolbachia intracellular endosymbiont. By use of a specific antibody, NOS was demonstrated in extracts of A. viteae and Dirofilaria immitis. The localization pattern of NOS in A. viteae was similar to that seen in B. malayi, with the enzyme localized to the body wall muscles of both sexes, developing spermatozoa, intrauterine sperm, and early embryos. By use of DAF-2, a fluorescent indicator specific for nitric oxide, the embryos of B. malayi and A. viteae were demonstrated to produce NO ex utero. The near identical staining patterns seen in A. viteae and B. malayi argue that NO is not produced by Wolbachia, nor is it produced by the nematodes in response to the infection. Localization of NOS to the sperm of filarial nematodes suggests a role for NO during fertilization as has been described for sea urchin and ascidian fertilization. Demonstration of the activity of embryonic NOS supports our earlier hypothesis that NO is a signaling molecule during embryogenesis in filarial nematodes.}, }
@article {pmid11381334, year = {2001}, author = {Thao, ML and Clark, MA and Burckhardt, DH and Moran, NA and Baumann, P}, title = {Phylogenetic analysis of vertically transmitted psyllid endosymbionts (Candidatus Carsonella ruddii) based on atpAGD and rpoC: comparisons with 16S-23S rDNA-derived phylogeny.}, journal = {Current microbiology}, volume = {42}, number = {6}, pages = {419-421}, doi = {10.1007/s002840010240}, pmid = {11381334}, issn = {0343-8651}, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; DNA-Directed RNA Polymerases/genetics ; Evolution, Molecular ; Gammaproteobacteria/*classification/genetics ; Hemiptera/*microbiology ; Phylogeny ; Proton-Translocating ATPases/genetics ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Symbiosis ; }, abstract = {Psyllids are insects that harbor endosymbionts (Candidatuus Carsonella ruddii) within specialized cells found in the insect's body cavity. Previous phylogenetic analyses based on endosymbiont 16S-23S ribosomal DNA and a host gene were concordant (M.L. Thao, et al., Appl. Env. Microbiol. 66:2898, 2000). Additional analyses with atpAGD and rpoBC gave similar trees showing the agreement expected from organisms that evolve through vertical transmission with no gene exchange.}, }
@article {pmid11375084, year = {2001}, author = {Arakaki, N and Miyoshi, T and Noda, H}, title = {Wolbachia-mediated parthenogenesis in the predatory thrips Franklinothrips vespiformis (Thysanoptera: Insecta).}, journal = {Proceedings. Biological sciences}, volume = {268}, number = {1471}, pages = {1011-1016}, doi = {10.1098/rspb.2001.1628}, pmid = {11375084}, issn = {0962-8452}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Female ; Genes, Bacterial ; Insecta/microbiology/*physiology ; Male ; *Parthenogenesis ; Phylogeny ; Polymerase Chain Reaction/methods ; Temperature ; Tetracycline/pharmacology ; Wolbachia/classification/genetics/isolation &amp; purification/*physiology ; }, abstract = {Wolbachia are bacterial endosymbionts in arthropods and filarial nematodes. They cause thelytoky, which is a form of parthenogenesis in which females produce females without males, in hymenopteran insects. Infection of this parthenogenesis-inducing Wolbachia has been restricted to the order Hymenoptera, but was found in another insect order, Thysanoptera. A parthenogenetic colony of a predatory thrips Franklinothrips vespiformis (Aeolothripidae) possessed B-group Wolbachia. Male progeny were produced from this thrips by heat and tetracycline treatments. Males produced motile sperm, which were transferred to the female spermatheca by mating. However, the mating did not affect the sex ratios of the next generation, suggesting that the sperm do not fertilize the eggs.}, }
@article {pmid11371588, year = {2001}, author = {Suh, SO and Noda, H and Blackwell, M}, title = {Insect symbiosis: derivation of yeast-like endosymbionts within an entomopathogenic filamentous lineage.}, journal = {Molecular biology and evolution}, volume = {18}, number = {6}, pages = {995-1000}, doi = {10.1093/oxfordjournals.molbev.a003901}, pmid = {11371588}, issn = {0737-4038}, mesh = {Animals ; Ascomycota/classification/genetics ; DNA, Fungal/chemistry/genetics ; Evolution, Molecular ; Insecta/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Yeast-like endosymbionts (YLSs) of insects often are restricted to specific hosts and are essential to the host's survival. For example, in planthoppers (Homoptera: Delphacidae), endosymbionts function in sterol utilization and nitrogen recycling for the hosts. Our study, designed to investigate evolutionary changes in the YLS lineage involved in the planthopper association, strongly suggests an origin of the YLSs from within the filamentous ascomycetes (Euascomycetes), not the true yeasts (Saccharomycetes), as their morphology might indicate. During divergence of the planthopper YLSs, dramatic changes would have occurred in the insect-fungus interaction and the fungal morphology that have previously been undescribed in filamentous ascomycetes. Phylogenetic trees were based on individual and combined data sets of 2.6 kb of the nuclear small- and large-subunit ribosomal RNA genes for YLSs from three rice planthoppers (Laodelphax striatellus, Nilaparvata lugens, and Sogatella furcifera) compared with 56 other fungi. Parsimony analysis placed the planthopper YLSs within Cordyceps (Euascomycetes: Hypocreales: Clavicipitaceae), a genus of filamentous insects and a few fungal pathogenic ascomycetes. Another YLS species restricted to the aphid Hamiltonaphis styraci (Homoptera: Aphididae) was a sister taxon to the planthopper YLSS: Filamentous insect pathogens (Metarhizium and Beauveria) specific to the same species of insect hosts as the YLSs also formed lineages within the Clavicipitaceae, but these were distinct from the clade comprising YLS species. Trees constrained to include the YLSs in families of the Hypocreales other than the Clavicipitaceae were rejected by the Kishino-Hasegawa test. In addition, the results of this study support a hypothesis of two independent origins of insect-associated YLSs from among filamentous ascomycetes: the planthopper YLSs in the Clavicipitaceae and the YLSs associated with anobiid beetles (Symbiotaphrina species). Several lineages of true yeasts (Saccharomycetes) also formed endosymbiotic associations with beetles, but they were not closely related to either group derived from the filamentous ascomycetes.}, }
@article {pmid11357130, year = {2001}, author = {Dubilier, N and Mülders, C and Ferdelman, T and de Beer, D and Pernthaler, A and Klein, M and Wagner, M and Erséus, C and Thiermann, F and Krieger, J and Giere, O and Amann, R}, title = {Endosymbiotic sulphate-reducing and sulphide-oxidizing bacteria in an oligochaete worm.}, journal = {Nature}, volume = {411}, number = {6835}, pages = {298-302}, doi = {10.1038/35077067}, pmid = {11357130}, issn = {0028-0836}, mesh = {Aerobiosis ; Agar ; Animals ; Carbon Dioxide/metabolism ; Deltaproteobacteria/genetics/*metabolism/ultrastructure ; Gammaproteobacteria/genetics/*metabolism/ultrastructure ; In Situ Hybridization, Fluorescence ; Kinetics ; Likelihood Functions ; Microscopy, Electron ; Models, Biological ; Molecular Sequence Data ; Oligochaeta/*microbiology/ultrastructure ; Oxidation-Reduction ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Silicon Dioxide ; Sulfates/*metabolism ; Sulfides/*metabolism ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {Stable associations of more than one species of symbiont within a single host cell or tissue are assumed to be rare in metazoans because competition for space and resources between symbionts can be detrimental to the host. In animals with multiple endosymbionts, such as mussels from deep-sea hydrothermal vents and reef-building corals, the costs of competition between the symbionts are outweighed by the ecological and physiological flexibility gained by the hosts. A further option for the coexistence of multiple symbionts within a host is if these benefit directly from one another, but such symbioses have not been previously described. Here we show that in the gutless marine oligochaete Olavius algarvensis, endosymbiotic sulphate-reducing bacteria produce sulphide that can serve as an energy source for sulphide-oxidizing symbionts of the host. Thus, these symbionts do not compete for resources but rather share a mutalistic relationship with each other in an endosymbiotic sulphur cycle, in addition to their symbiotic relationship with the oligochaete host.}, }
@article {pmid11355885, year = {2001}, author = {Masui, S and Kuroiwa, H and Sasaki, T and Inui, M and Kuroiwa, T and Ishikawa, H}, title = {Bacteriophage WO and virus-like particles in Wolbachia, an endosymbiont of arthropods.}, journal = {Biochemical and biophysical research communications}, volume = {283}, number = {5}, pages = {1099-1104}, doi = {10.1006/bbrc.2001.4906}, pmid = {11355885}, issn = {0006-291X}, mesh = {Animals ; Bacteriophages/genetics/*isolation &amp; purification/ultrastructure ; Base Sequence ; Female ; Genome, Bacterial ; Gryllidae/*microbiology ; Lysogeny ; Molecular Sequence Data ; Open Reading Frames ; Ovary/microbiology ; Symbiosis/*physiology ; Wolbachia/genetics/*physiology/*virology ; }, abstract = {Wolbachia are intracellular symbionts mainly found in arthropods, causing various sexual alterations on their hosts by unknown mechanisms. Here we report the results that strongly suggest that Wolbachia have virus-like particles of phage WO, which was previously identified as a prophage-like element in the Wolbachia genome. Wolbachia (strain wTai) infection in an insect was detected with the antibody against Wsp, an outer surface protein of Wolbachia, by fluorescence microscopy and immunoelectron-microscopy for the first time. Virus-like particles in Wolbachia were observed by electron-microscopy. The 0.22-microm filtrate of insect ovary contained DAPI-positive particles, and PCR analysis demonstrated that a phage WO DNA passed through the filter while Wolbachia DNA were eliminated, suggesting that the DAPI-positive particles were phage WO.}, }
@article {pmid11347902, year = {2001}, author = {Legen, J and Miséra, S and Herrmann, RG and Meurer, J}, title = {Map positions of 69 Arabidopsis thaliana genes of all known nuclear encoded constituent polypeptides and various regulatory factors of the photosynthetic membrane: a case study.}, journal = {DNA research : an international journal for rapid publication of reports on genes and genomes}, volume = {8}, number = {2}, pages = {53-60}, doi = {10.1093/dnares/8.2.53}, pmid = {11347902}, issn = {1340-2838}, mesh = {Arabidopsis/*genetics ; *Chromosome Mapping ; Chromosomes, Artificial, Bacterial/genetics ; Crosses, Genetic ; Gene Duplication ; *Genome, Plant ; Membrane Proteins/biosynthesis/genetics/*physiology ; Nuclear Proteins/biosynthesis/genetics/*physiology ; Photosynthetic Reaction Center Complex Proteins/genetics ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Thylakoids/chemistry/genetics/*physiology ; }, abstract = {Landsberg erecta x Columbia F8 recombinant inbred lines of Arabidopsis thaliana, arrayed BAC clones covering most of the genome, and databank sequence information were used to map the positions of 69 genes in the genome of A. thaliana. These genes encode all known constituents of the photosynthetic thylakoid membrane, some regulatory factors involved in its biogenesis, and the RNA polymerases of nuclear origin that operate in chloroplasts and mitochondria. Designations of novel genes are proposed. The data of these three approaches are generally consistent, although ambiguities have been noted for some genome segments and with gene duplications. For thylakoid multi-subunit structures, no positional clustering of genes has been found, not even for genes encoding different subunits of the same membrane complex. The genes of the lhc superfamily encoding antenna apoproteins and their relatives are a particularly intriguing example. The lack of positional clustering is consistent with phylogenetically independent gene translocations from the plastid (endosymbiont) to the nucleus. This raises the basic question of how independently translocated genes which acquired different promoter sequences and transit peptides were functionally integrated into common signal transduction chains.}, }
@article {pmid11339864, year = {2001}, author = {Shweiki, D}, title = {Earth--moon evolution: implications for the mechanism of the biological clock?.}, journal = {Medical hypotheses}, volume = {56}, number = {4}, pages = {547-551}, doi = {10.1054/mehy.2000.1259}, pmid = {11339864}, issn = {0306-9877}, mesh = {Animals ; *Biological Clocks ; *Biological Evolution ; *Earth, Planet ; Models, Theoretical ; *Moon ; Time ; }, abstract = {The geophysical characteristics of the planet Earth dictate the physiological traits of living organisms. Changes in the geophysical conditions over the course of geological time are responsible for major evolutionary changes in life emergence and evolvement. Calendar day length is one of earth's geophysical characteristics which is under a constant, if extremely small, progressive change. This enforces an adjustment of circadian rhythmicity throughout geological time. The calendar day has extended approximately 9 hours in the last 3.5 billion years. Two mechanisms for circadian-rhythm adjustment are suggested: a directional selection mechanism -- an endogenous -- oriented explanation regarding a genetic drift in the population's endogenous oscillation toward a lengthened daily cycle; and an exogenous calibration mechanism - a hypothesis on the existence of a geophysical responsive element which senses a geophysical stimuli and calibrates the inner cellular oscillation in accordance with the length of the calendar day. A distinguishing experiment between the two explanations is suggested and discussed. Circadian rhythm mechanism and the evolution of circadian rhythmicity are tightly connected. Circadian rhythms' evolutionary theories are discussed in light of their contribution to our understanding of the selective pressures being applied throughout geological time and of how, once the clock has been established, it maintains an ongoing adjustment to a continuous change in the length of day.I argue that the exogenous calibration mechanism combines with the endosymbiont coordination theory, together, present an explanation to the path by which the calendar day adjustment was acquired and maintained. This hypothesis suggests a role for gravity cyclic force and for cytoskeleton's components in calendar day adjustment mechanism and circadian rhythm entrainment.}, }
@article {pmid11334953, year = {2001}, author = {Dale, C and Welburn, SC}, title = {The endosymbionts of tsetse flies: manipulating host-parasite interactions.}, journal = {International journal for parasitology}, volume = {31}, number = {5-6}, pages = {628-631}, doi = {10.1016/s0020-7519(01)00151-5}, pmid = {11334953}, issn = {0020-7519}, mesh = {Acetylglucosamine/metabolism ; Ampicillin/pharmacology ; Animals ; Anti-Bacterial Agents/pharmacology ; Chitinases/biosynthesis ; Enterobacteriaceae/drug effects/genetics/*physiology ; Female ; Host-Parasite Interactions ; Insect Vectors ; Male ; Streptozocin/pharmacology ; Symbiosis/physiology ; Tetracycline/pharmacology ; Trypanosoma/growth &amp; development/physiology ; Tsetse Flies/growth &amp; development/*microbiology/parasitology ; }, abstract = {Through understanding the mechanisms by which tsetse endosymbionts potentiate trypanosome susceptibility in tsetse, it may be possible to engineer modified endosymbionts which, when introduced into tsetse, render these insects incapable of transmitting parasites. In this study we have assayed the effect of three different antibiotics on the endosymbiotic microflora of tsetse (Glossina morsitans morsitans). We showed that the broad-spectrum antibiotics, ampicillin and tetracycline, have a dramatic impact on tsetse fecundity and pupal emergence, effectively rendering these insects sterile. This results from the loss of the tsetse primary endosymbiont, Wigglesworthia glossinidia, which is eradicated by ampicillin and tetracycline treatment. Using the sugar analogue and antibiotic, streptozotocin, we demonstrated specific elimination of the tsetse secondary endosymbiont, Sodalis glossinidius, with no observed detrimental effect upon W. glossinidia. The specific eradication of S. glossinidius had a negligible effect upon the reproductive capability of tsetse but did effect a significant reduction in fly longevity. Furthermore, elimination of S. glossinidius resulted in increased refractoriness to trypanosome infection in tsetse, providing further evidence that S. glossinidius plays an important role in potentiating trypanosome susceptibility in this important disease vector. In the light of these findings, we highlight progress made towards developing recombinant Sodalis strains engineered to avoid potentiating trypanosome susceptibility in tsetse. In particular, we focus on the chitinase/N-acetyl-D-glucosamine catabolic machinery of Sodalis which has previously been implicated in causing immune inhibition in tsetse.}, }
@article {pmid11328780, year = {2001}, author = {Hermans, PG and Hart, CA and Trees, AJ}, title = {In vitro activity of antimicrobial agents against the endosymbiont Wolbachia pipientis.}, journal = {The Journal of antimicrobial chemotherapy}, volume = {47}, number = {5}, pages = {659-663}, doi = {10.1093/jac/47.5.659}, pmid = {11328780}, issn = {0305-7453}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Cells, Cultured/microbiology ; Doxycycline/*pharmacology ; Humans ; Insecta ; Microbial Sensitivity Tests ; Rickettsiaceae Infections/microbiology ; Wolbachia/*drug effects ; }, abstract = {Arthropod-transmitted (filarial) nematodes are important causes of disease in humans in tropical countries, yet no safe drug appropriate for mass delivery kills the adult worms. However, most filarial nematodes contain rickettsia-like bacteria of the genus Wolbachia, and related bacteria also occur in insects. There is increasing evidence that these bacteria have significant functions in the biology of filarial nematodes. They are thus important targets in the search for antifilarial drugs and experiments in animals and humans have suggested that antibiotic therapy has potential in treating filarial infections. To optimize future clinical trials there is a need for a fast and simple in vitro drug screen to compare drug efficacies against Wolbachia. In the absence of Wolbachia-infected nematode cell lines, we have utilized an Aedes albopictus insect cell line, naturally infected with Wolbachia, to test the activity of antimicrobial agents. Of the five antibiotics tested, doxycycline, oxytetracycline and rifampicin showed good activity (MICs of 0.0625, 4 and 0.0625 mg/L, respectively) whereas ciprofloxacin and penicillin were shown to have no effect.}, }
@article {pmid11315189, year = {2001}, author = {Bauer, J and Hiltbrunner, A and Kessler, F}, title = {Molecular biology of chloroplast biogenesis: gene expression, protein import and intraorganellar sorting.}, journal = {Cellular and molecular life sciences : CMLS}, volume = {58}, number = {3}, pages = {420-433}, doi = {10.1007/PL00000867}, pmid = {11315189}, issn = {1420-682X}, mesh = {Biological Transport ; Carrier Proteins/metabolism ; Chloroplast Proteins ; Chloroplasts/*metabolism ; *Gene Expression Regulation, Developmental ; *Gene Expression Regulation, Plant ; Genes, Plant ; Hydrogen-Ion Concentration ; Intracellular Membranes/metabolism ; Light ; Membrane Proteins/metabolism ; *Membrane Transport Proteins ; Molecular Biology ; Organelles/metabolism ; Photosynthesis/genetics ; Plant Proteins/genetics/*metabolism ; Signal Recognition Particle ; Thylakoids/metabolism ; }, abstract = {The chloroplast is the hallmark organelle of plants. It performs photosynthesis and is therefore required for photoautotrophic plant growth. The chloroplast is the most prominent member of a family of related organelles termed plastids which are ubiquitous in plant cells. Biogenesis of the chloroplast from undifferentiated proplastids is induced by light. The generally accepted endosymbiont hypothesis states that chloroplasts have arisen from an internalized cyanobacterial ancestor. Although chloroplasts have maintained remnants of the ancestral genome (plastome), the vast majority of the genes encoding chloroplast proteins have been transferred to the nucleus. This poses two major challenges to the plant cell during chloroplast biogenesis: First, light and developmental signals must be interpreted to coordinately express genetic information contained in two distinct compartments. This is to ensure supply and stoichiometry of abundant chloroplast components. Second, developing chloroplasts must efficiently import nuclear encoded and cytosolically synthesized proteins. A subset of proteins, including such encoded by the plastome, must further be sorted to the thylakoid compartments for assembly into the photosynthetic apparatus.}, }
@article {pmid11308016, year = {2001}, author = {Tomáska, L and Nosek, J and Kucejová, B}, title = {Mitochondrial single-stranded DNA-binding proteins: in search for new functions.}, journal = {Biological chemistry}, volume = {382}, number = {2}, pages = {179-186}, doi = {10.1515/BC.2001.025}, pmid = {11308016}, issn = {1431-6730}, mesh = {Amino Acid Sequence ; Animals ; Bacterial Proteins/metabolism ; Candida/genetics/metabolism ; DNA, Single-Stranded/*metabolism ; DNA-Binding Proteins/*chemistry/genetics/*metabolism ; *Evolution, Molecular ; Humans ; Mitochondria/*metabolism ; Molecular Sequence Data ; Protein Conformation ; Sequence Homology, Amino Acid ; }, abstract = {During the evolution of the eukaryotic cell, genes encoding proteins involved in the metabolism of mitochondrial DNA (mtDNA) have been transferred from the endosymbiont into the host genome. Mitochondrial single-stranded DNA-binding (mtSSB) proteins serve as an excellent argument supporting this aspect of the endosymbiotic theory. The crystal structure of the human mtSSB, together with an abundance of biochemical and genetic data, revealed several exciting features of mtSSB proteins and enabled a detailed comparison with their prokaryotic counterparts. Moreover, identification of a novel member of the mtSSB family, mitochondrial telomere-binding protein of the yeast Candida parapsilosis, has raised interesting questions regarding mtDNA metabolism and evolution.}, }
@article {pmid11306586, year = {2001}, author = {Minic, Z and Simon, V and Penverne, B and Gaill, F and Hervé, G}, title = {Contribution of the bacterial endosymbiont to the biosynthesis of pyrimidine nucleotides in the deep-sea tube worm Riftia pachyptila.}, journal = {The Journal of biological chemistry}, volume = {276}, number = {26}, pages = {23777-23784}, doi = {10.1074/jbc.M102249200}, pmid = {11306586}, issn = {0021-9258}, mesh = {Animals ; Aspartate Carbamoyltransferase/metabolism ; Bacteria/enzymology/*metabolism ; Bacterial Proteins/metabolism ; Carbamoyl-Phosphate Synthase (Ammonia)/metabolism ; Chromatography, Ion Exchange ; Dihydroorotase/metabolism ; Glutamate-Ammonia Ligase/metabolism ; Invertebrates/anatomy &amp; histology/enzymology/*metabolism/*microbiology ; Models, Biological ; Nitrate Reductase ; Nitrate Reductases/metabolism ; Orotic Acid/analogs &amp; derivatives/metabolism ; Pyrimidine Nucleotides/*biosynthesis ; Seawater ; *Symbiosis ; Tissue Extracts/analysis ; }, abstract = {The deep-sea tube worm Riftia pachyptila (Vestimentifera) from hydrothermal vents lives in an intimate symbiosis with a sulfur-oxidizing bacterium. That involves specific interactions and obligatory metabolic exchanges between the two organisms. In this work, we analyzed the contribution of the two partners to the biosynthesis of pyrimidine nucleotides through both the "de novo" and "salvage" pathways. The first three enzymes of the de novo pathway, carbamyl-phosphate synthetase, aspartate transcarbamylase, and dihydroorotase, were present only in the trophosome, the symbiont-containing tissue. The study of these enzymes in terms of their catalytic and regulatory properties in both the trophosome and the isolated symbiotic bacteria provided a clear indication of the microbial origin of these enzymes. In contrast, the succeeding enzymes of this de novo pathway, dihydroorotate dehydrogenase and orotate phosphoribosyltransferase, were present in all body parts of the worm. This finding indicates that the animal is fully dependent on the symbiont for the de novo biosynthesis of pyrimidines. In addition, it suggests that the synthesis of pyrimidines in other tissues is possible from the intermediary metabolites provided by the trophosomal tissue and from nucleic acid degradation products since the enzymes of the salvage pathway appear to be present in all tissues of the worm. Analysis of these salvage pathway enzymes in the trophosome strongly suggested that these enzymes belong to the worm. In accordance with this conclusion, none of these enzyme activities was found in the isolated bacteria. The enzymes involved in the production of the precursors of carbamyl phosphate and nitrogen assimilation, glutamine synthetase and nitrate reductase, were also investigated, and it appears that these two enzymes are present in the bacteria.}, }
@article {pmid11296829, year = {2001}, author = {Ono, M and Braig, HR and Munstermann, LE and Ferro, C and O'Neill, SL}, title = {Wolbachia infections of phlebotomine sand flies (Diptera: Psychodidae).}, journal = {Journal of medical entomology}, volume = {38}, number = {2}, pages = {237-241}, doi = {10.1603/0022-2585-38.2.237}, pmid = {11296829}, issn = {0022-2585}, support = {AI 34521/AI/NIAID NIH HHS/United States ; AI 40620/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Base Sequence ; DNA, Bacterial ; Molecular Sequence Data ; Polymerase Chain Reaction/methods ; Psychodidae/*microbiology ; Wolbachia/classification/genetics/*isolation &amp; purification ; }, abstract = {Old and New World phlebotomine sand fly species were screened for infection with Wolbachia, intracellular bacterial endosymbionts found in many arthropods and filarial nematodes. Of 53 samples representing 15 species, nine samples offour species were found positive for Wolbachia by polymerase chain reaction amplification using primers for the Wolbachia surface protein (wsp) gene. Five of the wsp gene fragments from four species were cloned, sequenced, and used for phylogenetic analysis. These wsp sequences were placed in three different clades within the arthropod associated Wolbachia (groups A and B), suggesting that Wolbacia has infected sand flies on more than one occasion. Two distantly related sand fly species, Lutzomyia (Psanthyromyia) shannoi (Dyar) and Lutzomyia (Nyssomyia) whitmani (Antunes &amp; Coutinho), infected with an identical Wolbachia strain suggest a very recent horizontal transmission.}, }
@article {pmid11274340, year = {2001}, author = {Weber, RE and Vinogradov, SN}, title = {Nonvertebrate hemoglobins: functions and molecular adaptations.}, journal = {Physiological reviews}, volume = {81}, number = {2}, pages = {569-628}, doi = {10.1152/physrev.2001.81.2.569}, pmid = {11274340}, issn = {0031-9333}, mesh = {Animals ; Erythrocytes/physiology ; Hemoglobins/*chemistry/*physiology ; Invertebrates/*physiology ; Models, Molecular ; Oxyhemoglobins/metabolism ; Protein Conformation ; }, abstract = {Hemoglobin (Hb) occurs in all the kingdoms of living organisms. Its distribution is episodic among the nonvertebrate groups in contrast to vertebrates. Nonvertebrate Hbs range from single-chain globins found in bacteria, algae, protozoa, and plants to large, multisubunit, multidomain Hbs found in nematodes, molluscs and crustaceans, and the giant annelid and vestimentiferan Hbs comprised of globin and nonglobin subunits. Chimeric hemoglobins have been found recently in bacteria and fungi. Hb occurs intracellularly in specific tissues and in circulating red blood cells (RBCs) and freely dissolved in various body fluids. In addition to transporting and storing O(2) and facilitating its diffusion, several novel Hb functions have emerged, including control of nitric oxide (NO) levels in microorganisms, use of NO to control the level of O(2) in nematodes, binding and transport of sulfide in endosymbiont-harboring species and protection against sulfide, scavenging of O(2)in symbiotic leguminous plants, O(2)sensing in bacteria and archaebacteria, and dehaloperoxidase activity useful in detoxification of chlorinated materials. This review focuses on the extensive variation in the functional properties of nonvertebrate Hbs, their O(2)binding affinities, their homotropic interactions (cooperativity), and the sensitivities of these parameters to temperature and heterotropic effectors such as protons and cations. Whenever possible, it attempts to relate the ligand binding properties to the known molecular structures. The divergent and convergent evolutionary trends evident in the structures and functions of nonvertebrate Hbs appear to be adaptive in extending the inhabitable environment available to Hb-containing organisms.}, }
@article {pmid11270436, year = {2001}, author = {Clark, JW and Hossain, S and Burnside, CA and Kambhampati, S}, title = {Coevolution between a cockroach and its bacterial endosymbiont: a biogeographical perspective.}, journal = {Proceedings. Biological sciences}, volume = {268}, number = {1465}, pages = {393-398}, pmid = {11270436}, issn = {0962-8452}, mesh = {Animals ; Bacteria/classification/*genetics ; *Biological Evolution ; Cockroaches/classification/*microbiology ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Genetic Variation ; Phylogeny ; RNA, Ribosomal, 16S ; RNA, Ribosomal, 23S ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Cryptocercus are subsocial, xylophagous cockroaches that live in temperate forests. Like other cockroaches, Cryptocercus harbour endosymbiotic bacteria in their fat bodies. Two species of Cryptocercus occur in the palaearctic, one each in eastern Russia and south-central China. In the USA, there are five species: one in the north-west and four in the south-east. Little is known about the relationship between the Eurasian and North American Cryptocercus or the causes of the disjunct distribution. Here, a molecular phylogeny for six out of the seven Cryptocercus species and their endosymbionts is inferred in an attempt to understand the evolution and biogeography of the genus. Our analysis showed that the North American Cryptocercus are monophyletic, suggesting that a single colonization event was followed by vicariance. There was complete concordance between the host and endosymbiont phylogenetic trees. Divergence estimates based on endosymbiont DNA sequences suggested that the palaearctic and nearctic Cryptocercus diverged 70-115 million years (Myr) ago and the eastern- and western-USA species diverged 53-88 Myr ago. These divergence estimates were correlated with biogeographical events, and a hypothesis is presented to explain the current distribution of Cryptocercus. Our findings suggest that Cryptocercus has had a long evolutionary history, dating back to the Jurassic.}, }
@article {pmid11259647, year = {2001}, author = {Nierman, WC and Feldblyum, TV and Laub, MT and Paulsen, IT and Nelson, KE and Eisen, JA and Heidelberg, JF and Alley, MR and Ohta, N and Maddock, JR and Potocka, I and Nelson, WC and Newton, A and Stephens, C and Phadke, ND and Ely, B and DeBoy, RT and Dodson, RJ and Durkin, AS and Gwinn, ML and Haft, DH and Kolonay, JF and Smit, J and Craven, MB and Khouri, H and Shetty, J and Berry, K and Utterback, T and Tran, K and Wolf, A and Vamathevan, J and Ermolaeva, M and White, O and Salzberg, SL and Venter, JC and Shapiro, L and Fraser, CM}, title = {Complete genome sequence of Caulobacter crescentus.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {7}, pages = {4136-4141}, pmid = {11259647}, issn = {0027-8424}, mesh = {Adaptation, Biological/genetics ; Caulobacter crescentus/*genetics ; Cell Cycle/genetics ; DNA Methylation ; Dinucleotide Repeats ; *Genome, Bacterial ; Molecular Sequence Data ; Peptide Hydrolases/genetics ; Phylogeny ; Signal Transduction ; Transcription, Genetic ; }, abstract = {The complete genome sequence of Caulobacter crescentus was determined to be 4,016,942 base pairs in a single circular chromosome encoding 3,767 genes. This organism, which grows in a dilute aquatic environment, coordinates the cell division cycle and multiple cell differentiation events. With the annotated genome sequence, a full description of the genetic network that controls bacterial differentiation, cell growth, and cell cycle progression is within reach. Two-component signal transduction proteins are known to play a significant role in cell cycle progression. Genome analysis revealed that the C. crescentus genome encodes a significantly higher number of these signaling proteins (105) than any bacterial genome sequenced thus far. Another regulatory mechanism involved in cell cycle progression is DNA methylation. The occurrence of the recognition sequence for an essential DNA methylating enzyme that is required for cell cycle regulation is severely limited and shows a bias to intergenic regions. The genome contains multiple clusters of genes encoding proteins essential for survival in a nutrient poor habitat. Included are those involved in chemotaxis, outer membrane channel function, degradation of aromatic ring compounds, and the breakdown of plant-derived carbon sources, in addition to many extracytoplasmic function sigma factors, providing the organism with the ability to respond to a wide range of environmental fluctuations. C. crescentus is, to our knowledge, the first free-living alpha-class proteobacterium to be sequenced and will serve as a foundation for exploring the biology of this group of bacteria, which includes the obligate endosymbiont and human pathogen Rickettsia prowazekii, the plant pathogen Agrobacterium tumefaciens, and the bovine and human pathogen Brucella abortus.}, }
@article {pmid11251800, year = {2001}, author = {Sandström, JP and Russell, JA and White, JP and Moran, NA}, title = {Independent origins and horizontal transfer of bacterial symbionts of aphids.}, journal = {Molecular ecology}, volume = {10}, number = {1}, pages = {217-228}, doi = {10.1046/j.1365-294x.2001.01189.x}, pmid = {11251800}, issn = {0962-1083}, mesh = {Animals ; Aphids/genetics/*microbiology ; Bacteriophages/genetics/metabolism ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Enterobacteriaceae/*genetics/ultrastructure ; *Gene Transfer, Horizontal ; *Genes, Bacterial ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; *Sequence Analysis, DNA ; Symbiosis/*physiology ; }, abstract = {Many insect groups have obligate associations with primary endosymbionts: mutualistic bacteria that are maternally transmitted and derived from an ancient infection. Often, the same insects are hosts to 'secondary' bacterial symbionts which are maternally transmitted but relatively labile within host lineages. To explore the dynamics of secondary symbiont associations in aphids, we characterized bacteria infecting 15 species of macrosiphine aphids using DNA sequencing, diagnostic polymerase chain reaction (PCR), diagnostic restriction digests, phylogenetic analyses, and electron microscopy to examine aphids from nature and from laboratory colonies. Three types of bacteria besides Buchnera were found repeatedly; all three fall within the Enterobacteriaceae. The R-type has a 16S rDNA less than 0.1% different from that of the secondary symbiont previously reported from Acyrthosiphon pisum and is related to Serratia species. The T-type includes a symbiont previously reported from a whitefly; the U-type comprises a new cluster near the T-type. The T-type was found in every one of 40 Uroleucon ambrosiae clones collected throughout the United States. In contrast, A. pisum individuals were infected by any combination of the three symbiont types. Secondary symbionts were maternally transmitted for 11 months within laboratory-reared A. pisum clones and were present in sexually produced eggs. PCR screens for a bacteriophage, APSE-1, indicated its presence in both A. pisum and U. ambrosiae containing secondary symbionts. Electron microscopy of R-type and T-type bacteria in A. pisum and in U. ambrosiae revealed rod-shaped organisms that attain extremely high densities within a few bacteriocytes.}, }
@article {pmid11240637, year = {2001}, author = {Spaulding, AW and von Dohlen, CD}, title = {Psyllid endosymbionts exhibit patterns of co-speciation with hosts and destabilizing substitutions in ribosomal RNA.}, journal = {Insect molecular biology}, volume = {10}, number = {1}, pages = {57-67}, doi = {10.1046/j.1365-2583.2001.00231.x}, pmid = {11240637}, issn = {0962-1075}, mesh = {Animals ; Base Sequence ; DNA, Bacterial/*analysis/classification ; DNA, Complementary ; DNA, Ribosomal/*analysis/classification ; Eubacterium/classification/*genetics ; Evolution, Molecular ; Hemiptera/*microbiology ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Ribosomal/analysis/chemistry/classification ; RNA, Ribosomal, 16S/*analysis/chemistry/classification ; Symbiosis ; }, abstract = {Eubacterial 16S rDNAs were sequenced from endosymbionts of seven psyllids (Psylloidea) and one whitefly (Aleyrodoidea), to investigate the evolution of endosymbionts and their hosts. Primary endosymbionts from all psyllids formed a highly supported clade, tentatively placed as the sister to whitefly primary endosymbionts, and showing several points of congruence with the host morphological phylogeny. Almost all host taxa yielded an additional eubacterial sequence, related either to known psyllid secondary endosymbionts or to other insect endosymbionts or parasites. The relationships of some secondary endosymbionts also suggested cospeciation with psyllid hosts, or ancient horizontal transfers. All primary endosymbionts, and some secondary endosymbionts, exhibited molecular genetic effects of a long-term, intracellular existence in their biased nucleotide content and decreased stability of rRNA secondary structure.}, }
@article {pmid11237467, year = {2001}, author = {Loppin, B and Berger, F and Couble, P}, title = {Paternal chromosome incorporation into the zygote nucleus is controlled by maternal haploid in Drosophila.}, journal = {Developmental biology}, volume = {231}, number = {2}, pages = {383-396}, doi = {10.1006/dbio.2000.0152}, pmid = {11237467}, issn = {0012-1606}, mesh = {Aneuploidy ; Animals ; Cell Movement ; Cell Nucleus/*metabolism/ultrastructure ; Chromosomes/*metabolism/ultrastructure ; Drosophila ; Female ; Fertilization/physiology ; Haploidy ; Heterochromatin/physiology ; Male ; Microscopy, Confocal ; *Mitosis ; Mutation ; Phenotype ; Sex Factors ; Time Factors ; Zygote/*physiology/ultrastructure ; }, abstract = {maternal haploid (mh) is a strict maternal effect mutation that causes the production of haploid gynogenetic embryos (eggs are fertilized but only maternal chromosomes participate in development). We conducted a cytological analysis of fertilization and early development in mh eggs to elucidate the mechanism of paternal chromosome elimination. In mh eggs, as in wild-type eggs, male and female pronuclei migrate and appose, the first mitotic spindle forms, and both parental sets of chromosomes congress on the metaphase plate. In contrast to control eggs, mh paternal sister chromatids fail to separate in anaphase of the first division. As a consequence the paternal chromatin stretches and forms a bridge in telophase. During the first three embryonic divisions, damaged paternal chromosomes are progressively eliminated from the spindles that organize around maternal chromosomes. A majority of mh embryos do not survive the deleterious presence of aneuploid nuclei and rapidly arrest their development. The rest of mh embryos develop as haploid gynogenetic embryos and die before hatching. The mh phenotype is highly reminiscent of the early developmental defects observed in eggs fertilized by ms(3)K81 mutant males and in eggs produced in incompatible crosses of Drosophila harboring the endosymbiont bacteria Wolbachia.}, }
@article {pmid11222582, year = {2001}, author = {Clark, MA and Baumann, L and Thao, ML and Moran, NA and Baumann, P}, title = {Degenerative minimalism in the genome of a psyllid endosymbiont.}, journal = {Journal of bacteriology}, volume = {183}, number = {6}, pages = {1853-1861}, pmid = {11222582}, issn = {0021-9193}, mesh = {Amino Acids/analysis ; Animals ; Bacterial Proteins/chemistry ; Base Composition ; Base Sequence ; Codon ; DNA, Bacterial/chemistry/genetics ; DNA, Intergenic/genetics ; Gammaproteobacteria/chemistry/*genetics ; *Genome, Bacterial ; Hemiptera/*microbiology ; Molecular Sequence Data ; Open Reading Frames/genetics ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; *Symbiosis ; rRNA Operon/genetics ; }, abstract = {Psyllids, like aphids, feed on plant phloem sap and are obligately associated with prokaryotic endosymbionts acquired through vertical transmission from an ancestral infection. We have sequenced 37 kb of DNA of the genome of Carsonella ruddii, the endosymbiont of psyllids, and found that it has a number of unusual properties revealing a more extreme case of degeneration than was previously reported from studies of eubacterial genomes, including that of the aphid endosymbiont Buchnera aphidicola. Among the unusual properties are an exceptionally low guanine-plus-cytosine content (19.9%), almost complete absence of intergenic spaces, operon fusion, and lack of the usual promoter sequences upstream of 16S rDNA. These features suggest the synthesis of long mRNAs and translational coupling. The most extreme instances of base compositional bias occur in the genes encoding proteins that have less highly conserved amino acid sequences; the guanine-plus-cytosine content of some protein-coding sequences is as low as 10%. The shift in base composition has a large effect on proteins: in polypeptides of C. ruddii, half of the residues consist of five amino acids with codons low in guanine plus cytosine. Furthermore, the proteins of C. ruddii are reduced in size, with an average of about 9% fewer amino acids than in homologous proteins of related bacteria. These observations suggest that the C. ruddii genome is not subject to constraints that limit the evolution of other known eubacteria.}, }
@article {pmid11214099, year = {2000}, author = {Townson, S and Hutton, D and Siemienska, J and Hollick, L and Scanlon, T and Tagboto, SK and Taylor, MJ}, title = {Antibiotics and Wolbachia in filarial nematodes: antifilarial activity of rifampicin, oxytetracycline and chloramphenicol against Onchocerca gutturosa, Onchocerca lienalis and Brugia pahangi.}, journal = {Annals of tropical medicine and parasitology}, volume = {94}, number = {8}, pages = {801-816}, doi = {10.1080/00034980020027988}, pmid = {11214099}, issn = {0003-4983}, mesh = {Animals ; Anti-Bacterial Agents/*therapeutic use ; Brugia pahangi/*drug effects/ultrastructure ; Cattle ; Chloramphenicol/therapeutic use ; Female ; Filariasis/*drug therapy ; Gerbillinae ; Male ; Mice ; Mice, Inbred CBA ; Microscopy, Electron ; Onchocerciasis/*drug therapy ; Oxytetracycline/therapeutic use ; Rifampin/therapeutic use ; Treatment Outcome ; Wolbachia/*drug effects/ultrastructure ; }, abstract = {The activity against filarial parasites of the antibiotics rifampicin, oxytetracycline and chloramphenicol was examined. In addition, transmission electron microscopy was used to study the effects of rifampicin and oxytetracycline on filarial tissues and on the endosymbiont bacterium, Wolbachia. When tested in vitro at a concentration of 50.0 microM, each of the three antibiotics significantly reduced the motility levels of male Onchocerca gutturosa. Rifampicin, however, was the most active, virtually immobilizing the parasite by the end of the 40-day trial and producing an 84% reduction in viability (as measured by formazan-based colorimetry). In tests against O. lienalis microfilariae (mff) in CBA mice, the numbers of mff recovered after treatment with oxytetracycline at 100, 25 or 6.5 mg/kg daily, for 15 days, were 56% (P < or = 0.03), 38% (P> 0.05) and 45% (P = 0.05) less than that recovered from the untreated controls, respectively. In another trial in mice, rifampicin (100 mg/kg daily for 15 days) was found to be the most active (causing a 74% reduction in the number of mff recovered--approximately equal to that achieved with the positive control of a single dose of ivermectin at 2 microg/kg), with chloramphenicol also showing significant activity (39% reduction). In further, in-vivo trials, at three dose levels (100, 25 or 6.25 mg/kg daily, for 15 days), all three antibiotics were tested against adult Brugia pahangi in the peritoneal cavities of jirds. None of the antibiotics produced a significant reduction in the numbers of live worms recovered, although a marginal effect was observed in eight of the nine antibiotic-treated groups. A further extended trial with rifampicin and oxytetracycline resulted in 43% and 38% reductions in worm recoveries, respectively (not statistically significant but consistent with a marginal effect); some of these worms appeared less motile and qualitatively in poor condition compared with those recovered from untreated jirds. Ultrastructural studies of these treated worms revealed that virtually all of the endosymbiont bacteria had been cleared from the parasite tissues. The tissues of the adult worms appeared to be largely intact but with a granulomatous response of host cells adhering to some specimens. However, developing uterine forms appeared to be abnormal and extensively damaged, showing an abrogation of embryogenesis. In contrast, worms recovered from control animals contained large numbers of Wolbachia, had no adherent host cells, and showed normal ultrastructure; the female worms exhibited a full range of intra-uterine developing stages from eggs to stretched mff. It is likely that the activity of these antibiotics against the endosymbiont Wolbachia causes the observed antifilarial activity, although some direct effect of each drug on filarial viability cannot be ruled out.}, }
@article {pmid11212896, year = {2000}, author = {Jaenicke, L}, title = {A problem cannot be solved unless one sees it (F. Schmitz 1883). Lothar geitler (1899-1990) and the endosymbionts: revolutionary as a twen, conservative till ripe old age.}, journal = {Protist}, volume = {151}, number = {4}, pages = {353-365}, doi = {10.1078/S1434-4610(04)70034-6}, pmid = {11212896}, issn = {1434-4610}, mesh = {History, 19th Century ; History, 20th Century ; *Phylogeny ; *Symbiosis ; }, }
@article {pmid11209779, year = {2000}, author = {Price, CS and Kim, CH and Posluszny, J and Coyne, JA}, title = {Mechanisms of conspecific sperm precedence in Drosophila.}, journal = {Evolution; international journal of organic evolution}, volume = {54}, number = {6}, pages = {2028-2037}, doi = {10.1111/j.0014-3820.2000.tb01246.x}, pmid = {11209779}, issn = {0014-3820}, support = {GM-07197/GM/NIGMS NIH HHS/United States ; R01 GM58260/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Drosophila/anatomy &amp; histology/microbiology/*physiology ; Female ; Genitalia, Male/anatomy &amp; histology ; Male ; Reproduction ; Sexual Behavior, Animal/physiology ; Spermatozoa/microbiology/*physiology ; Wolbachia/pathogenicity ; }, abstract = {The postmating, prezygotic isolating mechanism known as conspecific sperm precedence (CSP) may play an important role in speciation, and understanding the mechanism of CSP is important in reconstructing its evolution. When a Drosophila simulans female mates with both a D. simulans male and a D. mauritiana male, the vast majority of her progeny are fathered by D. simulans, regardless of the order of mating. The dearth of hybrid progeny does not result from inviability of eggs fertilized by heterospecific sperm or from the relative inviability of heterospecific larvae. Instead, CSP apparently results from a prefertilization obstacle to heterospecific sperm. We identified two independent barriers to heterospecific fertilization, sperm displacement and incapacitation, whose action depends on the order of mating. When a D. simulans female mates first with a conspecific male, the seminal fluid from this mating incapacitates heterospecific sperm transferred two days later. This sperm incapacitation occurs with no change in the retention of stored sperm over time, but does not occur when the conspecific mating lasts for only 5 min. When the order of matings is reversed, the seminal fluid from the second mating physically displaces heterospecific sperm from storage, even if the conspecific copulation lasts only 5 min. Conspecific sperm are not susceptible to displacement by a second conspecific copulation, but are susceptible to interference by heterospecific sperm if the conspecific copulation is interrupted after 12 min. Curing the D. mauritiana males of their infection with the endosymbiont Wolbachia had no effect on CSP. Sperm displacement and incapacitation involve the same basic mechanisms seen in second-male sperm precedence within species, supporting the hypothesis that CSP is an evolutionary by-product of adaptations affecting sperm competition within species.}, }
@article {pmid11207753, year = {1999}, author = {Horn, M and Fritsche, TR and Gautom, RK and Schleifer, KH and Wagner, M}, title = {Novel bacterial endosymbionts of Acanthamoeba spp. related to the Paramecium caudatum symbiont Caedibacter caryophilus.}, journal = {Environmental microbiology}, volume = {1}, number = {4}, pages = {357-367}, doi = {10.1046/j.1462-2920.1999.00045.x}, pmid = {11207753}, issn = {1462-2912}, support = {FO6 TW02279-01/TW/FIC NIH HHS/United States ; }, mesh = {Acanthamoeba/classification/genetics/*microbiology ; Alphaproteobacteria/*classification/*genetics ; Animals ; Base Sequence ; DNA, Ribosomal/analysis/genetics ; Genes, rRNA ; Humans ; In Situ Hybridization, Fluorescence ; Microscopy, Confocal ; Molecular Sequence Data ; Paramecium/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Acanthamoebae are increasingly being recognized as hosts for obligate bacterial endosymbionts, most of which are presently uncharacterized. In this study, the phylogeny of three Gram-negative, rod-shaped endosymbionts and their Acanthamoeba host cells was analysed by the rRNA approach. Comparative analyses of 16S rDNA sequences retrieved from amoebic cell lysates revealed that the endosymbionts of Acanthamoeba polyphaga HN-3, Acanthamoeba sp. UWC9 and Acanthamoeba sp. UWE39 are related to the Paramecium caudatum endosymbionts Caedibacter caryophilus, Holospora elegans and Holospora obtusa. With overall 16S rRNA sequence similarities to their closest relative, C. caryophilus, of between 87% and 93%, these endosymbionts represent three distinct new species. In situ hybridization with fluorescently labelled endosymbiont-specific 16S rRNA-targeted probes demonstrated that the retrieved 16S rDNA sequences originated from the endosymbionts and confirmed their intracellular localization. We propose to classify provisionally the endosymbiont of Acanthamoeba polyphaga HN-3 as 'Candidatus Caedibacter acanthamoebae', the endosymbiont of Acanthamoeba sp. strain UWC9 as 'Candidatus Paracaedibacter acanthamoebae' and the endosymbiont of Acanthamoeba sp. strain UWE39 as 'Candidatus Paracaedibacter symbiosus'. The phylogeny of the Acanthamoeba host cells was analysed by comparative sequence analyses of their 18S rRNA. Although Acanthamoeba polyphaga HN-3 clearly groups together with most of the known Acanthamoeba isolates (18S rRNA sequence type 4), Acanthamoeba sp. UWC9 and UWE39 exhibit <92% 18S rRNA sequence similarity to each other and to other Acanthamoeba isolates. Therefore, we propose two new sequence types (T13 and T14) within the genus Acanthamoeba containing, respectively, Acanthamoeba sp. UWC9 and Acanthamoeba sp. UWE39.}, }
@article {pmid11197770, year = {2001}, author = {Casiraghi, M and Anderson, TJ and Bandi, C and Bazzocchi, C and Genchi, C}, title = {A phylogenetic analysis of filarial nematodes: comparison with the phylogeny of Wolbachia endosymbionts.}, journal = {Parasitology}, volume = {122 Pt 1}, number = {}, pages = {93-103}, doi = {10.1017/s0031182000007149}, pmid = {11197770}, issn = {0031-1820}, mesh = {Animals ; Bacterial Outer Membrane Proteins/genetics ; Bacterial Proteins/genetics ; *Cytoskeletal Proteins ; Electron Transport Complex IV/genetics ; Filarioidea/*classification/enzymology/genetics/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/chemistry ; Symbiosis ; Thelazioidea/classification/enzymology/genetics ; Wolbachia/*classification/enzymology ; }, abstract = {Infection with the endosymbiotic bacteria Wolbachia is widespread in filarial nematodes. Previous studies have suggested concordance between the phylogeny of Wolbachia with that of their nematode hosts. However, there is only one published molecular phylogenetic study of filarial species, based on the 5S rRNA gene spacer. The phylogeny proposed by this study is partially incongruent with previous classifications of filarial nematodes, based on morphological characters. Furthermore, both traditional classifications and molecular phylogenies are, in part, inconsistent with the phylogeny of Wolbachia. Here we report mitochondrial cytochrome oxidase I (COI) gene sequences for 11 species of filaria and for another spirurid nematode which was included as an outgroup. In addition, 16S rRNA, wsp and ftsZ gene sequences were generated for the Wolbachia of several filarial species, in order to complete the available data sets and further resolve the phylogeny of Wolbachia in nematodes. We used these data to evaluate whether nematode and Wolbachia phylogenies are concordant. Some of the possible phylogenetic reconstructions based on COI gene were congruent with the phylogeny of Wolbachia and supported the grouping of the rodent filaria Litomosoides sigmodontis with the lymphatic filariae (i.e. Brugia spp. and Wuchereria spp.) and the sister group relationship of Dirofilaria spp. and Onchocerca spp. However, the placement of the Wolbachia-free filaria Acanthocheilonema viteae is ambiguous and dependent on the phylogenetic methods used.}, }
@article {pmid11197128, year = {2000}, author = {Funk, DJ and Helbling, L and Wernegreen, JJ and Moran, NA}, title = {Intraspecific phylogenetic congruence among multiple symbiont genomes.}, journal = {Proceedings. Biological sciences}, volume = {267}, number = {1461}, pages = {2517-2521}, pmid = {11197128}, issn = {0962-8452}, mesh = {Animals ; Aphids/*genetics/*microbiology ; Buchnera/*genetics ; Chromosomes, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Evolution, Molecular ; Genome ; Molecular Sequence Data ; *Phylogeny ; Plasmids/genetics ; Polymorphism, Genetic ; Sequence Analysis, DNA ; Symbiosis ; }, abstract = {Eukaryotes often form intimate endosymbioses with prokaryotic organisms. Cases in which these symbionts are transmitted cytoplasmically to host progeny create the potential for co-speciation or congruent evolution among the distinct genomes of these partners. If symbionts do not move horizontally between different eukaryotic hosts, strict phylogenetic congruence of their genomes is predicted and should extend to relationships within a single host species. Conversely, even rare 'host shifts' among closely related lineages should yield conflicting tree topologies at the intraspecific level. Here, we investigate the historical associations among four symbiotic genomes residing within an aphid host: the mitochondrial DNA of Uroleucon ambrosiae aphids, the bacterial chromosome of their Buchnera bacterial endosymbionts, and two plasmids associated with Buchnera. DNA sequence polymorphisms provided a significant phylogenetic signal and no homoplasy for each data set, yielding completely and significantly congruent phylogenies for these four genomes and no evidence of horizontal transmission. This study thus provides the first evidence for strictly vertical transmission and 'co-speciation' of symbiotic organisms at the intraspecific level, and represents the lowest phylogenetic level at which such coevolution has been demonstrated. These results may reflect the obligate nature of this intimate mutualism and indicate opportunities for adaptive coevolution among linked symbiont genomes.}, }
@article {pmid11197127, year = {2000}, author = {Bazzocchi, C and Ceciliani, F and McCall, JW and Ricci, I and Genchi, C and Bandi, C}, title = {Antigenic role of the endosymbionts of filarial nematodes: IgG response against the Wolbachia surface protein in cats infected with Dirofilaria immitis.}, journal = {Proceedings. Biological sciences}, volume = {267}, number = {1461}, pages = {2511-2516}, pmid = {11197127}, issn = {0962-8452}, mesh = {Amino Acid Sequence ; Animals ; Antigens, Bacterial/genetics/*immunology ; Base Sequence ; Blotting, Western ; Cat Diseases/immunology/*parasitology ; Cats ; Dirofilaria immitis/*microbiology ; Dirofilariasis/parasitology ; Immunoglobulin G/blood ; Membrane Proteins/genetics/immunology ; Molecular Sequence Data ; Sequence Alignment ; *Symbiosis ; Wolbachia/*immunology ; }, abstract = {Filarial nematodes harbour intracellular endosymbiotic bacteria, which have been assigned to the genus Wolbachia. These bacteria appear to play an important role in the pathogenesis of filarial diseases through their lipopolysaccharides. In view of the presence of Wolbachia endosymbionts in the body of filarial nematodes, one might also expect that proteins from these bacteria play an antigenic role in humans and animals affected by filariases. To test this hypothesis, we produced in recombinant form the surface protein WSP and a portion of the cell-cycle protein FTSZ from the Wolbachia of Dirofilaria immitis. Western immunoblot assays were then performed using cat sera to test the immunogenicity of these proteins. Sera were collected from owners' cats, which were either sero-negative or sero-positive for D. immitis and from cats before and after experimental infection with D. immitis. FTSZ was recognized in Western blots by sera from both positive and negative cats and from both uninfected and experimentally infected cats. WSP was recognized only by sera from positive cats and from cats experimentally infected with D. immitis; this protein was not recognized by sera from negative cats and from cats before experimental infection with D. immitis. The results of Western blot assays on WSP thus support the hypothesis that infection with filarial nematodes induces the production of antibodies against Wolbachia proteins.}, }
@article {pmid11195584, year = {2000}, author = {Pimenov, NV and Savvichev, AS and Rusanov, II and Lein, AIu and Ivanov, MV}, title = {[Microbiological processes of the carbon and sulfur cycle in cold methane seeps in the North Atlantic].}, journal = {Mikrobiologiia}, volume = {69}, number = {6}, pages = {831-843}, pmid = {11195584}, issn = {0026-3656}, mesh = {Bacteria/*metabolism/ultrastructure ; Carbon/*metabolism ; Cold Temperature ; Microscopy, Electron ; Oceans and Seas ; Sulfur/*metabolism ; Water Microbiology ; }, abstract = {Functioning of microbial communities in surface sediments of the Haakon Mosby underwater mud volcano (lat. 72 degrees N) and in gas seepage fields of the Vestnesa Ridge was investigated using Mir-1 and Mir-2 deep-sea submersibles during the 40th expedition of the research vessel Academician Mstislav Keldysh. Large areas of sedimentary deposits of the Haakon Mosby mud volcano (HMMV) and pockmarks of the Vestnesa Ridge (VR) are covered with bacterial mats 0.1 to 0.5 cm thick. The microbial community making up bacterial mats of the HMMV was predominated by large filamentous bacteria with filaments measuring up to 100 microns in length and 2 to 8 microns in width. The occurrence of rosettes allowed the observed filamentous bacteria to be referred to the morphologically similar genera Leucothrix or Thiothrix. Three morphological types of filamentous bacteria were identified in bacterial mats covering VR pockmarks. Filaments of type one are morphologically similar with representatives of the genera Thioploca or Desmanthos. Type two filaments had numerous inclusions of sulfur and resembled representatives of the genus Thiothrix. The third morphological type was constituted by single filaments made up of tightly connected disk-like cells and can, apparently, be assigned to the genus Beggiatoa. The rates of methane oxidation (up to 1570 microliters C/(dm3 day)) and sulfate reduction (up to 17 mg S/(dm3 day)) measured in surface sediments of HMMV and VR were close to the maximum rates of these processes observed in badly polluted regions of the northwestern shelf of the Black Sea. High rates of microbiological processes correlated with the high number of bacteria. The rate of methane production in sediments studied was notably lower and ranged from 0.1 to 3.5 microliters CH4/(dm3 day). Large areas of the HMMV caldera were populated by pogonophoras, represented by the two species, Sclerolinum sp. and Oligobrachia sp. The mass development of Sclerolinum sp. in the HMMV caldera was by the activity of aerobic methane-oxidizing bacteria localized inside the cells of these animals. Bacterial cells were also found in the trophosome tissue of Oligobrachia sp., but in cells of these bacteria, we did not observe the membrane structures typical of methanotrophs. The localization pattern of pogonophoras on the surface of reduced sediments suggests that the predominant bacteria in Oligobrachia tissues are sulfur-oxidizing endosymbionts.}, }
@article {pmid11177735, year = {2001}, author = {Schwartzman, JD}, title = {Toxoplasmosis.}, journal = {Current infectious disease reports}, volume = {3}, number = {1}, pages = {85-89}, pmid = {11177735}, issn = {1523-3847}, abstract = {Recent advances in understanding toxoplasmosis have been made in the areas of the basic biology of the parasite and the host-parasite interaction, especially the cellular immune response. There is new insight into the biology of the cyst stage that is responsible for meat-associated transmission of infection and for the reactivation of disease in chronically infected humans. Fewer recent advances have been made in clinical diagnosis and treatment of toxoplasmosis. The fascinating revelation that Toxoplasma gondii contains an organelle--now known as the apicoplast--that derives from an algal endosymbiont, has opened many avenues of basic investigation. An understanding of the fundamental biology of T. gondii promises future progress in prevention or treatment of toxoplasmosis.}, }
@article {pmid11173035, year = {2001}, author = {Boschiroli, ML and Foulongne, V and O'Callaghan, D}, title = {Brucellosis: a worldwide zoonosis.}, journal = {Current opinion in microbiology}, volume = {4}, number = {1}, pages = {58-64}, doi = {10.1016/s1369-5274(00)00165-x}, pmid = {11173035}, issn = {1369-5274}, mesh = {Animals ; Brucella/classification/genetics/*pathogenicity ; *Brucellosis/epidemiology/microbiology/pathology ; Chromosomes, Bacterial ; *Genome, Bacterial ; Humans ; Phylogeny ; Zoonoses ; }, abstract = {Brucella is one of the world's major zoonotic pathogens, and is responsible for enormous economic losses as well as considerable human morbidity in endemic areas. Control of brucellosis requires practical solutions that can be easily applied to the field. Rapid DNA-based diagnostic tests for both humans and livestock have now proved themselves on an experimental level. Data on the virulence of Brucella suggest common mechanisms shared with plant pathogens and endosymbionts of the alpha-proteobacteria. Understanding virulence will have practical repercussions in the realms of vaccine development and, perhaps, development of new antibiotics. The first complete Brucella genome sequence will be released soon, and this will help greatly in our understanding of the biology and evolution of this pathogen.}, }
@article {pmid11172045, year = {2001}, author = {Dale, C and Young, SA and Haydon, DT and Welburn, SC}, title = {The insect endosymbiont Sodalis glossinidius utilizes a type III secretion system for cell invasion.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {98}, number = {4}, pages = {1883-1888}, pmid = {11172045}, issn = {0027-8424}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Aedes ; Animals ; *Antigens, Bacterial ; Bacterial Proteins/genetics/physiology ; Base Sequence ; Cell Line ; DNA Transposable Elements ; DNA, Bacterial ; Enterobacteriaceae/classification/*genetics/metabolism/*pathogenicity ; Female ; Genes, Bacterial ; In Situ Hybridization/methods ; *Membrane Glycoproteins ; Molecular Sequence Data ; Mutagenesis, Insertional ; Phylogeny ; Polymerase Chain Reaction/methods ; Proton-Translocating ATPases/genetics/physiology ; Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Sodalis glossinidius is a maternally transmitted secondary endosymbiont residing intracellularly in tissues of the tsetse flies, Glossina spp. In this study, we have used Tn5 mutagenesis and a negative selection procedure to derive a S. glossinidius mutant that is incapable of invading insect cells in vitro and is aposymbiotic when microinjected into tsetse. This mutant strain harbors Tn5 integrated into a chromosomal gene sharing high sequence identity with a type III secretion system invasion gene (invC) previously identified in Salmonella enterica. With the use of degenerate PCR, we have amplified a further six Sodalis inv/spa genes sharing high sequence identity with type III secretion system genes encoded by Salmonella pathogenicity island 1. Phylogenetic reconstructions based on the inv/spa genes of Sodalis and other members of the family Enterobacteriaceae have consistently identified a well-supported clade containing Sodalis and the enteric pathogens Shigella and Salmonella. These results suggest that Sodalis may have evolved from an ancestor with a parasitic intracellular lifestyle, possibly a latter-day entomopathogen. These observations lend credence to a hypothesis suggesting that vertically transmitted mutualistic endosymbionts evolve from horizontally transmitted parasites through a parasitism-mutualism continuum.}, }
@article {pmid11166312, year = {2001}, author = {Kellner, RL}, title = {Suppression of pederin biosynthesis through antibiotic elimination of endosymbionts in Paederus sabaeus.}, journal = {Journal of insect physiology}, volume = {47}, number = {4-5}, pages = {475-483}, doi = {10.1016/s0022-1910(00)00140-2}, pmid = {11166312}, issn = {1879-1611}, abstract = {Biosynthesis of the unique defensive compound pederin is confined to female rove beetles of the genus Paederus (Coleoptera: Staphylinidae). These (+)-females endow their eggs with toxin whereas (-)-females, which occur both naturally and in laboratory reared specimens, do not. The latter are aposymbionts lacking biosynthetic capabilities because of endosymbiotic deficiency. They can, however, be induced to accumulate pederin if fed with (+)-eggs during larval development. The endosymbionts can thus be transmitted by ingestion of (+)-Eggs. (+)-eggs treated with benzylpenicillin, erythromycin, oxytetracycline or streptomycin show that the induction of pederin accumulation depends on the antibiotic's spectrum of efficaciousness, its dosage and duration of the treatment. Certain bacteria, probably belonging to the gram-negative type, must be transmitted to produce (+)-females.}, }
@article {pmid11157237, year = {2001}, author = {Minerdi, D and Fani, R and Gallo, R and Boarino, A and Bonfante, P}, title = {Nitrogen fixation genes in an endosymbiotic Burkholderia strain.}, journal = {Applied and environmental microbiology}, volume = {67}, number = {2}, pages = {725-732}, pmid = {11157237}, issn = {0099-2240}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; Burkholderia/*genetics/growth &amp; development/metabolism ; Fungi/genetics/*growth &amp; development ; Molecular Sequence Data ; Nitrogen Fixation/*genetics ; Operon/genetics ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Alignment ; Sequence Analysis, DNA ; Spores, Fungal/genetics ; *Symbiosis ; }, abstract = {In this paper we report the identification and characterization of a DNA region containing putative nif genes and belonging to a Burkholderia endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. A genomic library of total DNA extracted from the fungal spores was also representative of the bacterial genome and was used to investigate the prokaryotic genome. Screening of the library with Azospirillum brasilense nifHDK genes as the prokaryotic probes led to the identification of a 6,413-bp region. Analysis revealed three open reading frames encoding putative proteins with a very high degree of sequence similarity with the two subunits (NifD and NifK) of the component I and with component II (NifH) of nitrogenase from different diazotrophs. The three genes were arranged in an operon similar to that shown by most archaeal and bacterial diazotrophs. PCR experiments with primers designed on the Burkholderia nifHDK genes and Southern blot analysis demonstrate that they actually belong to the genome of the G. margarita endosymbiont. They offer, therefore, the first sequence for the nif operon described for Burkholderia. Reverse transcriptase PCR experiments with primers designed on the Burkholderia nifH and nifD genes and performed on total RNA extracted from spores demonstrate that the gene expression was limited to the germination phase. A phylogenetic analysis performed on the available nifK sequences placed the endosymbiotic Burkholderia close to A. brasilense.}, }
@article {pmid11156972, year = {2001}, author = {Funk, DJ and Wernegreen, JJ and Moran, NA}, title = {Intraspecific variation in symbiont genomes: bottlenecks and the aphid-buchnera association.}, journal = {Genetics}, volume = {157}, number = {2}, pages = {477-489}, pmid = {11156972}, issn = {0016-6731}, mesh = {Alleles ; Animals ; Aphids/*genetics ; Buchnera/*genetics ; Chromosomes ; DNA/genetics ; Evolution, Molecular ; *Genetic Variation ; *Genome ; Haplotypes ; Mitochondria/metabolism ; Models, Genetic ; Mutation ; Phylogeny ; Polymorphism, Genetic ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Buchnera are maternally transmitted bacterial endosymbionts that synthesize amino acids that are limiting in the diet of their aphid hosts. Previous studies demonstrated accelerated sequence evolution in Buchnera compared to free-living bacteria, especially for nonsynonymous substitutions. Two mechanisms may explain this acceleration: relaxed purifying selection and increased fixation of slightly deleterious alleles under drift. Here, we test the divergent predictions of these hypotheses for intraspecific polymorphism using Buchnera associated with natural populations of the ragweed aphid, Uroleucon ambrosiae. Contrary to expectations under relaxed selection, U. ambrosiae from across the United States yielded strikingly low sequence diversity at three Buchnera loci (dnaN, trpBC, trpEG), revealing polymorphism three orders of magnitude lower than in enteric bacteria. An excess of nonsynonymous polymorphism and of rare alleles was also observed. Local sampling of additional dnaN sequences revealed similar patterns of polymorphism and no evidence of food plant-associated genetic structure. Aphid mitochondrial sequences further suggested that host bottlenecks and large-scale dispersal may contribute to genetic homogenization of aphids and symbionts. Together, our results support reduced N(e) as a primary cause of accelerated sequence evolution in Buchnera. However, our study cannot rule out the possibility that mechanisms other than bottlenecks also contribute to reduced N(e) at aphid and endosymbiont loci.}, }
@article {pmid11155997, year = {2000}, author = {Vandekerckhove, TT and Willems, A and Gillis, M and Coomans, A}, title = {Occurrence of novel verrucomicrobial species, endosymbiotic and associated with parthenogenesis in Xiphinema americanum-group species (Nematoda, Longidoridae).}, journal = {International journal of systematic and evolutionary microbiology}, volume = {50 Pt 6}, number = {}, pages = {2197-2205}, doi = {10.1099/00207713-50-6-2197}, pmid = {11155997}, issn = {1466-5026}, mesh = {Animals ; DNA, Ribosomal/analysis ; Female ; Gram-Negative Bacteria/*classification/genetics/physiology ; Indoles ; Microscopy, Electron ; Microscopy, Fluorescence/methods ; Molecular Sequence Data ; Nematoda/*microbiology/physiology ; Parthenogenesis/*physiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Numerous micro-organisms have been described as cytoplasmic symbionts of eukaryotes. Many so-called obligate endosymbionts rely exclusively on maternal (vertical or transovarial) transmission to maintain themselves, rendering them dependent on the host sex ratio, which they would tend to manipulate to their own advantage. The latter phenomenon is often associated with the presence of Wolbachia pipientis (alpha-Proteobacteria) in arthropods and nematodes. A potentially similar situation was discovered involving members of a new clade of Verrucomicrobia, another main line of descent in the Bacteria. Nematode species of the Xiphinema americanum group (Nematoda, Longidoridae), viz. Xiphinema americanum, Xiphinema rivesi and Xiphinema brevicollum, each harbour their own specific verrucomicrobial endosymbionts. They are exclusively maternally inherited and their hosts reproduce by thelytokous (mother-to-daughter) parthenogenesis, males being extremely rare. A new genus, 'Candidatus Xiphinematobacter' gen. nov., along with three new candidate verrucomicrobial species, 'Candidatus Xiphinematobacter americani' sp. nov., 'Candidatus Xiphinematobacter rivesi' sp. nov. and 'Candidatus Xiphinematobacter brevicolli' sp. nov., are described on the basis of transmission electron microscopy, scanning electron microscopy, DAPI (4',6-diamidino-2-phenylindole) epifluorescence microscopy and 16S rDNA sequence analysis. These are the first endosymbiotic species described among the Verrucomicrobia. They share a mean 16S rDNA similarity of about 93%, whereas similarity to their closest relative, clone WCHD3-88, is less than 87%. Thus, the endosymbionts form a homogeneous clade for which the new candidate genus 'Candidatus Xiphinematobacter' gen. nov. is proposed. The type species is 'Candidatus Xiphinematobacter brevicolli' sp. nov.}, }
@article {pmid11155982, year = {2000}, author = {Inagaki, Y and Dacks, JB and Doolittle, WF and Watanabe, KI and Ohama, T}, title = {Evolutionary relationship between dinoflagellates bearing obligate diatom endosymbionts: insight into tertiary endosymbiosis.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {50 Pt 6}, number = {}, pages = {2075-2081}, doi = {10.1099/00207713-50-6-2075}, pmid = {11155982}, issn = {1466-5026}, mesh = {Animals ; DNA, Ribosomal/analysis ; Diatoms/*growth &amp; development ; Dinoflagellida/*classification/*genetics/growth &amp; development ; *Evolution, Molecular ; Genes, rRNA ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The marine dinoflagellates Peridinium balticum and Peridinium foliaceum are known for bearing diatom endosymbionts instead of peridinin-containing plastids. While evidence clearly indicates that their endosymbionts are closely related, the relationship between the host dinoflagellate cells is not settled. To examine the relationship of the two dinoflagellates, the DNA sequences of nuclear small-subunit rRNA genes (SSU rDNA) from Peridinium balticum, Peridinium foliaceum and one other peridinin-containing species, Peridinium bipes, were amplified, cloned and sequenced. While phylogenetic analyses under simple models of nucleotide substitution weakly support the monophyly of Peridinium balticum and Peridinium foliaceum, analyses under more sophisticated models significantly increased the statistical support for this relationship. Combining these results with the similarity between the two endosymbionts, it is concluded that (i) the two hosts have the closest sister relationship among dinoflagellates tested, (ii) the hypothesis that the diatom endosymbiosis occurred prior to the separation of the host cells is most likely to explain their evolutionary histories, and (iii) phylogenetic inferences under complex nucleotide evolution models seem to be able to compensate significant rate variation in the two SSU rDNA.}, }
@article {pmid11133977, year = {2001}, author = {Wernegreen, JJ and Moran, NA}, title = {Vertical transmission of biosynthetic plasmids in aphid endosymbionts (Buchnera).}, journal = {Journal of bacteriology}, volume = {183}, number = {2}, pages = {785-790}, pmid = {11133977}, issn = {0021-9193}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/classification/*genetics ; Genes, Bacterial ; Likelihood Functions ; Molecular Sequence Data ; Phylogeny ; Plasmids/classification/*genetics ; *Symbiosis ; }, abstract = {This study tested for horizontal transfer of plasmids among Buchnera aphidicola strains associated with ecologically and phylogenetically related aphid hosts (Uroleucon species). Phylogenetic congruence of Buchnera plasmid (trpEG and leuABC) and chromosomal (dnaN and trpB) genes supports strictly vertical long-term transmission of plasmids, which persist due to their contributions to host nutrition rather than capacity for infectious transfer. Synonymous divergences indicate elevated mutation on plasmids relative to chromosomal genes.}, }
@article {pmid11133434, year = {2001}, author = {Campbell, BJ and Cary, SC}, title = {Characterization of a novel spirochete associated with the hydrothermal vent polychaete annelid, Alvinella pompejana.}, journal = {Applied and environmental microbiology}, volume = {67}, number = {1}, pages = {110-117}, pmid = {11133434}, issn = {0099-2240}, mesh = {Animals ; DNA, Bacterial/analysis/genetics ; DNA, Ribosomal/analysis/genetics ; Electrophoresis/methods ; *Marine Biology ; Molecular Sequence Data ; Phylogeny ; Polychaeta/*microbiology ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Spirochaeta/*classification/genetics/physiology ; Symbiosis ; Temperature ; }, abstract = {A highly integrated, morphologically diverse bacterial community is associated with the dorsal surface of Alvinella pompejana, a polychaetous annelid that inhabits active high-temperature deep-sea hydrothermal vent sites along the East Pacific Rise (EPR). Analysis of a previously prepared bacterial 16S ribosomal DNA (rDNA) library identified a spirochete most closely related to an endosymbiont of the oligochete Olavius loisae. This spirochete phylotype (spirochete A) comprised only 2.2% of the 16S rDNA clone library but appeared to be much more dominant when the same sample was analyzed by denaturing gradient gel electrophoresis (DGGE) and the terminal restriction fragment length polymorphism procedure (12 to 18%). PCR amplification of the community with spirochete-specific primers used in conjunction with DGGE analysis identified two spirochete phylotypes. The first spirochete was identical to spirochete A but was present in only one A. pompejana specimen. The second spirochete (spirochete B) was 84.5% similar to spirochete A and, more interestingly, was present in the epibiont communities of all of the A. pompejana specimens sampled throughout the geographic range of the worm (13 degrees N to 32 degrees S along the EPR). The sequence variation of the spirochete B phylotype was less than 3% for the range of A. pompejana specimens tested, suggesting that a single spirochete species was present in the A. pompejana epibiotic community. Additional analysis of the environments surrounding the worm revealed that spirochetes are a ubiquitous component of high-temperature vents and may play an important role in this unique ecosystem.}, }
@article {pmid11128800, year = {2000}, author = {Fleury, F and Vavre, F and Ris, N and Fouillet, P and Boulétreau, M}, title = {Physiological cost induced by the maternally-transmitted endosymbiont Wolbachia in the Drosophila parasitoid Leptopilina heterotoma.}, journal = {Parasitology}, volume = {121 Pt 5}, number = {}, pages = {493-500}, doi = {10.1017/s0031182099006599}, pmid = {11128800}, issn = {0031-1820}, mesh = {Animals ; Drosophila melanogaster/*parasitology ; Female ; Fertility/physiology ; Host-Parasite Interactions ; Image Processing, Computer-Assisted ; Male ; Motor Activity/physiology ; Sex Ratio ; Videotape Recording ; Wasps/growth &amp; development/*microbiology/*physiology ; Wolbachia/*pathogenicity ; }, abstract = {Endosymbiotic bacteria of the genus Wolbachia infect a number of invertebrate species in which they induce various alterations in host reproduction, mainly cytoplasmic incompatibility (CI). In contrast to most other maternally transmitted parasites, manipulation of host reproduction makes the spread of Wolbachia possible even if they induce a physiological cost on their hosts. Current studies have shown that fitness consequences of Wolbachia infection could range from positive (mutualist) to negative (parasitic) but, in most cases, Wolbachia do not have strong deleterious effects on host fitness and the status of association remains unclear. Here, we show that in the Drosophila parasitoid wasp Leptopilina heterotoma, Wolbachia infection has a negative impact on several host fitness traits of both sexes. Fecundity, adult survival and locomotor performance are significantly reduced, whereas circadian rhythm, development time and offspring sex-ratio are not affected. Although the cost of bacterial infection can be overcome by effects on host reproduction i.e. cytoplasmic incompatibility, it could influence the spread of the bacterium at the early stages of the invasion process. Clearly, results underline the wide spectrum of phenotypic effects of Wolbachia infection and, to our knowledge, Wolbachia infection of L. heterotoma appears to be one of the most virulent that has ever been observed in insects.}, }
@article {pmid11112376, year = {2000}, author = {Sun, LV and Scoles, GA and Fish, D and O'Neill, SL}, title = {Francisella-like endosymbionts of ticks.}, journal = {Journal of invertebrate pathology}, volume = {76}, number = {4}, pages = {301-303}, doi = {10.1006/jipa.2000.4983}, pmid = {11112376}, issn = {0022-2011}, mesh = {Animals ; DNA, Bacterial/chemistry ; DNA, Ribosomal/chemistry ; *Francisella/classification/genetics ; Phylogeny ; *Symbiosis ; Ticks/*microbiology ; }, }
@article {pmid10943385, year = {1999}, author = {Buades, C and Michelena, JM and Latorre, A and Moya, A}, title = {Accelerated evolution in bacterial endosymbionts of aphids.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {2}, number = {1}, pages = {11-14}, pmid = {10943385}, issn = {1139-6709}, mesh = {Animals ; Aphids/*microbiology ; Base Composition ; Buchnera/*genetics ; *Evolution, Molecular ; Kinetics ; Proton-Translocating ATPases/genetics ; Sequence Homology, Nucleic Acid ; Species Specificity ; *Symbiosis ; }, abstract = {When compared with free living bacteria, it is proposed that there are at least two endosymbiotic processes in aphids based on the A + T content as well as the increased evolutionary rate of the beta-subunit of the F-ATPase complex in different endosymbiotic bacteria. The first well established process corresponds to the integration of Buchnera aphidicola more than 150 million years ago. The other is postulated to correspond to new endosymbiotic processes in which the bacteria involved contain less A + T and show a lower increase of evolutionary rates when compared with B. aphidicola. It is proposed, therefore, that endosymbioses are active processes in aphid evolution.}, }
@article {pmid11104819, year = {2000}, author = {Kurland, CG and Andersson, SG}, title = {Origin and evolution of the mitochondrial proteome.}, journal = {Microbiology and molecular biology reviews : MMBR}, volume = {64}, number = {4}, pages = {786-820}, pmid = {11104819}, issn = {1092-2172}, mesh = {Alphaproteobacteria/genetics ; *Biological Evolution ; Energy Metabolism ; Eukaryotic Cells ; *Mitochondria/genetics ; Models, Biological ; *Proteome ; Saccharomyces cerevisiae/physiology ; Symbiosis ; }, abstract = {The endosymbiotic theory for the origin of mitochondria requires substantial modification. The three identifiable ancestral sources to the proteome of mitochondria are proteins descended from the ancestral alpha-proteobacteria symbiont, proteins with no homology to bacterial orthologs, and diverse proteins with bacterial affinities not derived from alpha-proteobacteria. Random mutations in the form of deletions large and small seem to have eliminated nonessential genes from the endosymbiont-mitochondrial genome lineages. This process, together with the transfer of genes from the endosymbiont-mitochondrial genome to nuclei, has led to a marked reduction in the size of mitochondrial genomes. All proteins of bacterial descent that are encoded by nuclear genes were probably transferred by the same mechanism, involving the disintegration of mitochondria or bacteria by the intracellular membranous vacuoles of cells to release nucleic acid fragments that transform the nuclear genome. This ongoing process has intermittently introduced bacterial genes to nuclear genomes. The genomes of the last common ancestor of all organisms, in particular of mitochondria, encoded cytochrome oxidase homologues. There are no phylogenetic indications either in the mitochondrial proteome or in the nuclear genomes that the initial or subsequent function of the ancestor to the mitochondria was anaerobic. In contrast, there are indications that relatively advanced eukaryotes adapted to anaerobiosis by dismantling their mitochondria and refitting them as hydrogenosomes. Accordingly, a continuous history of aerobic respiration seems to have been the fate of most mitochondrial lineages. The initial phases of this history may have involved aerobic respiration by the symbiont functioning as a scavenger of toxic oxygen. The transition to mitochondria capable of active ATP export to the host cell seems to have required recruitment of eukaryotic ATP transport proteins from the nucleus. The identity of the ancestral host of the alpha-proteobacterial endosymbiont is unclear, but there is no indication that it was an autotroph. There are no indications of a specific alpha-proteobacterial origin to genes for glycolysis. In the absence of data to the contrary, it is assumed that the ancestral host cell was a heterotroph.}, }
@article {pmid11081576, year = {2000}, author = {Lee, JE and Ahn, TI}, title = {Periplasmic localization of a GroES homologue in Escherichia coli transformed with groESx cloned from Legionella-like endosymbionts in Amoeba proteus.}, journal = {Research in microbiology}, volume = {151}, number = {8}, pages = {605-618}, doi = {10.1016/s0923-2508(00)90133-5}, pmid = {11081576}, issn = {0923-2508}, mesh = {Amoeba/*genetics ; Animals ; Chaperonin 10/*analysis/genetics/physiology ; Escherichia coli/genetics/*metabolism ; Hot Temperature ; Legionella/*metabolism ; Recombinant Proteins/biosynthesis ; Symbiosis ; *Transformation, Bacterial ; }, abstract = {Escherichia coli MC4100 transformed with a groE homologous operon cloned from X-bacteria accumulated large amounts of the gene product when cultured at 30 or 37 degrees C. Heat shock for 10-30 min at 42 degrees C or ethanol (5%) shock for 2 h increased GroESx levels to about twice that in E. coli grown at 30 degrees C. The subcellular localization of GroESx in transformed E. coli was determined by several subcellular fractionation methods, by the analysis of extracted proteins in SDS polyacrylamide gels and by assays of marker enzymes. The GroESx protein was detected in both the periplasmic and cytoplasmic extracts and a large amount of the protein was accumulated in the periplasm. The GroEL protein and recombinant beta-galactosidase were exclusively localized in the cytoplasmic fraction, eliminating the possibility that periplasmic GroESx might be due to simple overproduction. N-terminal amino acid sequencing confirmed that the protein resolved on a 2-D gel was GroESx. This work represents the first report of the periplasmic location of GroES homologues in E. coli.}, }
@article {pmid11080372, year = {2000}, author = {Masui, S and Kamoda, S and Sasaki, T and Ishikawa, H}, title = {Distribution and evolution of bacteriophage WO in Wolbachia, the endosymbiont causing sexual alterations in arthropods.}, journal = {Journal of molecular evolution}, volume = {51}, number = {5}, pages = {491-497}, doi = {10.1007/s002390010112}, pmid = {11080372}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Animals ; Arthropods/genetics/*virology ; Bacteriophages/*genetics ; Cloning, Molecular ; DNA, Bacterial/chemistry/genetics ; DNA, Viral/chemistry/genetics ; *Evolution, Molecular ; Gene Expression Regulation, Viral ; Genes, Viral/genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sex Determination Processes ; Symbiosis/genetics ; Wolbachia/*genetics/virology ; }, abstract = {Wolbachia are obligatory intracellular and maternally inherited bacteria, known to infect many species of arthropod. In this study, we discovered a bacteriophage-like genetic element in Wolbachia, which was tentatively named bacteriophage WO. The phylogenetic tree based on phage WO genes of several Wolbachia strains was not congruent with that based on chromosomal genes of the same strains, suggesting that phage WO was active and horizontally transmitted among various Wolbachia strains. All the strains of Wolbachia used in this study were infected with phage WO. Although the phage genome contained genes of diverse origins, the average G+C content and codon usage of these genes were quite similar to those of a chromosomal gene of Wolbachia. These results raised the possibility that phage WO has been associated with Wolbachia for a very long time, conferring some benefit to its hosts. The evolution and possible roles of phage WO in various reproductive alterations of insects caused by Wolbachia are discussed.}, }
@article {pmid11076020, year = {2000}, author = {Vothknecht, UC and Soll, J}, title = {Protein import: the hitchhikers guide into chloroplasts.}, journal = {Biological chemistry}, volume = {381}, number = {9-10}, pages = {887-897}, doi = {10.1515/BC.2000.110}, pmid = {11076020}, issn = {1431-6730}, mesh = {Chloroplasts/*physiology ; Eukaryota/*physiology/ultrastructure ; *Plant Physiological Phenomena ; Plant Proteins/*metabolism ; Plastids/physiology/ultrastructure ; }, abstract = {Plastids originated from an endosymbiotic event between an early eukaryotic host cell and an ancestor of today's cyanobacteria. During the events by which the engulfed endosymbiont was transformed into a permanent organelle, many genes were transferred from the plastidal genome to the nucleus of the host cell. Proteins encoded by these genes are synthesised in the cytosol and subsequently translocated into the plastid. Therefore they contain an N-terminal cleavable transit sequence that is necessary for translocation. The sequence is plastid-specific, thus preventing mistargeting into other organelles. Receptors embedded into the outer envelope of the plastid recognise the transit sequences, and precursor proteins are translocated into the chloroplast by a proteinaceous import machinery located in both the outer and inner envelopes. Inside the stroma the transit sequences are cleaved off and the proteins are further routed to their final locations within the plastid.}, }
@article {pmid11074465, year = {2000}, author = {Mushahwar, IK}, title = {Recently discovered blood-borne viruses: are they hepatitis viruses or merely endosymbionts?.}, journal = {Journal of medical virology}, volume = {62}, number = {4}, pages = {399-404}, doi = {10.1002/1096-9071(200012)62:4&lt;399::aid-jmv1&gt;3.0.co;2-u}, pmid = {11074465}, issn = {0146-6615}, mesh = {Animals ; *Blood-Borne Pathogens ; Circoviridae/classification/genetics ; Circoviridae Infections/*virology ; *Flaviviridae/classification/genetics ; Hepatitis, Viral, Human/*virology ; Humans ; Symbiosis ; }, }
@article {pmid11070060, year = {2000}, author = {Stibitz, TB and Keeling, PJ and Bhattacharya, D}, title = {Symbiotic origin of a novel actin gene in the cryptophyte Pyrenomonas helgolandii.}, journal = {Molecular biology and evolution}, volume = {17}, number = {11}, pages = {1731-1738}, doi = {10.1093/oxfordjournals.molbev.a026271}, pmid = {11070060}, issn = {0737-4038}, mesh = {Actins/*genetics ; Amino Acid Sequence ; Base Sequence ; Blotting, Southern ; DNA/chemistry/genetics ; DNA, Complementary/chemistry/genetics ; Eukaryota/*genetics ; *Evolution, Molecular ; Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Rhodophyta/genetics ; Sequence Analysis, DNA ; Symbiosis/*genetics ; }, abstract = {Cryptophytes are photosynthetic protists that have acquired their plastids through the secondary symbiotic uptake of a red alga. A remarkable feature of cryptophytes is that they maintain a reduced form of the red algal nucleus, the nucleomorph, between the second and third plastid membranes (periplastidial compartment; PC). The nucleomorph is thought to be a transition state in the evolution of secondary plastids, with this genome ultimately being lost when photosynthesis comes under full control of the "host" nucleus (e.g., as in heterokonts, haptophytes, and euglenophytes). Genes presently found in the nucleomorph seem to be restricted to those involved in its own maintenance and to that of the plastid; other genes were lost as the endosymbiont was progressively reduced to its present state. Surprisingly, we found that the cryptophyte Pyrenomonas helgolandii possesses a novel type of actin gene that originated from the nucleomorph genome of the symbiont. Our results demonstrate for the first time that secondary symbionts can contribute genes to the host lineage which are unrelated to plastid function. These genes are akin to the products of gene duplication or lateral transfer and provide a source of evolutionary novelty that can significantly increase the genetic diversity of the host lineage. We postulate that this may be a common phenomenon in algae containing secondary plastids that has yet to be fully appreciated due to a dearth of evolutionary studies of nuclear genes in these taxa.}, }
@article {pmid11050446, year = {2000}, author = {Rotte, C and Henze, K and Müller, M and Martin, W}, title = {Origins of hydrogenosomes and mitochondria.}, journal = {Current opinion in microbiology}, volume = {3}, number = {5}, pages = {481-486}, doi = {10.1016/s1369-5274(00)00126-0}, pmid = {11050446}, issn = {1369-5274}, mesh = {Aerobiosis ; Alphaproteobacteria ; Anaerobiosis ; Animals ; *Biological Evolution ; *Electron Transport ; Eukaryota ; Mitochondria/*physiology ; Organelles/*physiology ; }, abstract = {Complete genome sequences for many oxygen-respiring mitochondria, as well as for some bacteria, leave no doubt that mitochondria are descendants of alpha-proteobacteria, a finding for which the endosymbiont hypothesis can easily account. Yet a wealth of data indicate that mitochondria and hydrogenosomes - the ATP-producing organelles of many anaerobic protists - share a common ancestry, a finding that traditional formulations of the endosymbiont hypothesis less readily accommodates. Available evidence suggests that a more in-depth understanding of the origins of eukaryotes and their organelles will hinge upon data from the genomes of protists that synthesize ATP without the need for oxygen.}, }
@article {pmid11034499, year = {2000}, author = {Sauer, C and Stackebrandt, E and Gadau, J and Hölldobler, B and Gross, R}, title = {Systematic relationships and cospeciation of bacterial endosymbionts and their carpenter ant host species: proposal of the new taxon Candidatus Blochmannia gen. nov.}, journal = {International journal of systematic and evolutionary microbiology}, volume = {50 Pt 5}, number = {}, pages = {1877-1886}, doi = {10.1099/00207713-50-5-1877}, pmid = {11034499}, issn = {1466-5026}, mesh = {Animals ; Ants/classification/enzymology/*microbiology ; Base Composition ; Base Sequence ; DNA, Bacterial/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Digestive System/microbiology ; Electron Transport Complex IV/genetics ; Gammaproteobacteria/*classification/genetics/isolation &amp; purification ; Genes, rRNA ; In Situ Hybridization ; Introns ; Mitochondria/enzymology ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; rRNA Operon ; }, abstract = {The systematic relationships of intracellular bacteria of 13 Camponotus species (carpenter ants) from America and Europe were compared to those of their hosts. Phylogenetic trees of the bacteria and the ants were based on 16S rDNA (rrs) gene sequences and mitochondrial cytochrome oxidase subunit I (COI) gene sequences, respectively. The bacterial endosymbionts of Camponotus spp. form a distinct lineage in the y-subclass of the Proteobacteria. The taxa most closely related to these bacteria are endosymbionts of aphids and the tsetse fly. The bacterial and host phylogenies deduced from the sequence data show a high degree of congruence, providing significant evidence for cospeciation of the bacteria and the ants and a maternal transmission route of the symbionts. The cloned rrs genes of the endosymbionts contain putative intervening sequences (IVSs) with a much lower G+C content than the mean of the respective rrs genes. By in situ hybridization specific 16S rDNA oligonucleotide probes verified the presence of the bacteria within tissues of three of the eukaryotic hosts. It is proposed that the endosymbionts of these three carpenter ants be assigned to a new taxon 'Candidatus Blochmannia gen. nov.' with the symbionts of the individual ants being species named according to their host, 'Candidatus Blochmannia floridanus sp. nov.', 'Candidatus Blochmannia herculeanus sp. nov.' and 'Candidatus Blochmannia rufipes sp. nov.'.}, }
@article {pmid11032741, year = {2000}, author = {Inagaki, J and Fujita, Y and Hase, T and Yamamoto, Y}, title = {Protein translocation within chloroplast is similar in Euglena and higher plants.}, journal = {Biochemical and biophysical research communications}, volume = {277}, number = {2}, pages = {436-442}, doi = {10.1006/bbrc.2000.3702}, pmid = {11032741}, issn = {0006-291X}, mesh = {Adenosine Triphosphate/pharmacology ; *Algal Proteins ; Amino Acid Sequence ; Animals ; Biological Evolution ; Chloroplasts/*metabolism/*physiology ; DNA, Complementary/metabolism ; Dose-Response Relationship, Drug ; Electrophoresis, Polyacrylamide Gel ; Euglena/chemistry/*metabolism ; Molecular Sequence Data ; Photosynthetic Reaction Center Complex Proteins/chemistry/*metabolism ; *Photosystem II Protein Complex ; Plasmids/chemistry ; Protein Biosynthesis ; Protein Processing, Post-Translational ; Protein Structure, Tertiary ; Protein Transport ; Proteins/*metabolism ; *Protozoan Proteins ; Sequence Homology, Amino Acid ; Spinacia oleracea/chemistry/metabolism ; Thylakoids/chemistry ; Time Factors ; Transcription, Genetic ; }, abstract = {It is currently thought that chloroplasts of higher plants were derived from endosymbiont oxygenic photosynthetic bacteria (primary endosymbiosis), while Euglena, a photosynthetic protista, gained chloroplasts by secondary endosymbiosis (i.e., incorporation of a photosynthetic eukaryote into heterotrophic eukaryotic host). To examine if the protein transport inside chloroplasts is similar between these organisms, we carried out heterologous protein import experiments with Euglena precursor proteins and spinach chloroplasts. The precursor of a 30-kDa subunit of the oxygen-evolving complex (OEC30) from the thylakoid lumen of Euglena chloroplasts contained the N-terminal signal, stroma targeting, and thylakoid transfer domains. Truncated preOEC30s lacking the N-terminal domain were post-translationally imported into spinach chloroplasts, transported into the thylakoid lumen, and processed to a mature protein. These results showed that protein translocations within chloroplasts in Euglena and higher plants are similar and supported the hypothesis that Euglena chloroplasts are derived from the ancestral Chlorophyta.}, }
@article {pmid11030433, year = {2000}, author = {Spiteller, D and Dettner, K and Bolan, W}, title = {Gut bacteria may be involved in interactions between plants, herbivores and their predators: microbial biosynthesis of N-acylglutamine surfactants as elicitors of plant volatiles.}, journal = {Biological chemistry}, volume = {381}, number = {8}, pages = {755-762}, doi = {10.1515/BC.2000.096}, pmid = {11030433}, issn = {1431-6730}, mesh = {Acylation ; Animals ; Bacteria/chemistry/*metabolism ; Bacterial Proteins/biosynthesis/metabolism/pharmacokinetics ; Biological Transport ; Chromatography, High Pressure Liquid ; Fatty Acids/analysis/metabolism ; *Food Chain ; Gastroesophageal Reflux/metabolism ; Glutamine/*analogs &amp; derivatives/biosynthesis/metabolism/pharmacokinetics ; Immunity, Innate ; Insecta/anatomy &amp; histology/metabolism/*microbiology ; Intestines/*microbiology ; Mass Spectrometry ; Molecular Structure ; Plants/*immunology ; Substrate Specificity ; Surface-Active Agents/metabolism/pharmacokinetics ; }, abstract = {N-Acylamino acids are dominant and widespread constituents of insect oral secretions (regurgitants), serving the insect as biosurfactants in the digestive process. During feeding the conjugates may be introduced into damaged leaves and contribute there to the elicitation of plant defenses such as the induction of volatile biosynthesis. From gut segments of Spodoptera exigua, Mamestra brassicae and Agrotis segetum 23 bacterial strains were isolated, ten of which were able to synthesise typical lepidopteran N-acylamino acids from externally added precursors. Four strains, Providencia rettgeri, Ochrobactrum spec., Myroides odoratus and Acinetobacter sp. genospecies 11 were identified on the basis of their 16 S rDNA. The organisms displayed a very broad substrate tolerance, since fatty acids of different chain length and different degree of saturation were converted into N-acylamino acids. Moreover, most of the proteinogenic amino acids, but not glutamic and aspartic acid, were used as substrates. The dominant occurrence of fatty acids conjugated with glutamine may result from a preferred transport of glutamine from the hemolymph into the gut of the insects. The involvement of bacteria in the biosynthesis of compounds which play a pivotal role in the interaction of plants, herbivores and their predators adds a new trophic level to this complex network of interactions. Due to their short generation cycle and the ease of adaptation endosymbiontic bacteria may have an outstanding importance for the coevolution of plant-insect interactions.}, }
@article {pmid11029673, year = {2000}, author = {Oh, HW and Kim, MG and Shin, SW and Bae, KS and Ahn, YJ and Park, HY}, title = {Ultrastructural and molecular identification of a Wolbachia endosymbiont in a spider, Nephila clavata.}, journal = {Insect molecular biology}, volume = {9}, number = {5}, pages = {539-543}, doi = {10.1046/j.1365-2583.2000.00218.x}, pmid = {11029673}, issn = {0962-1075}, mesh = {Animals ; Bacterial Proteins/genetics ; *Cytoskeletal Proteins ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Genes, Bacterial ; Microscopy, Electron ; Molecular Sequence Data ; Ovum/microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Spiders/*microbiology ; *Symbiosis ; Wolbachia/*classification/genetics/*ultrastructure ; }, abstract = {Wolbachia-like bacteria were observed in the egg cells of golden orb-weaving spider, Nephila clavata, by means of transmission electron microscopy. The bacteria exhibited the typical morphology of Wolbachia, including three enveloping membranes. Based on the amplification and sequencing of partial 16S rDNA and ftsZ gene, the bacteria were identified as Wolbachia, intracellular, transovarially inherited alpha-proteobacteria in invertebrates. Phylogenetic analysis based on 16S rDNA and ftsZ gene sequences invariably indicated that the intracellular bacteria from N. clavata belonged to group A Wolbachia, which were found only from insects. Clustering of Wolbachia from N. clavata with group A Wolbachia indicates that the bacteria were probably transferred horizontally between insects and the spider.}, }
@article {pmid11029071, year = {2000}, author = {Hongoh, Y and Ishikawa, H}, title = {Evolutionary studies on uricases of fungal endosymbionts of aphids and planthoppers.}, journal = {Journal of molecular evolution}, volume = {51}, number = {3}, pages = {265-277}, doi = {10.1007/s002390010088}, pmid = {11029071}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Animals ; Aphids/metabolism/*microbiology ; Base Sequence ; Cloning, Molecular ; DNA Primers/genetics ; DNA, Fungal/genetics ; Evolution, Molecular ; Fungi/classification/*enzymology/*genetics ; Genes, Fungal ; Hemiptera/metabolism/*microbiology ; Molecular Sequence Data ; Mutation ; Phylogeny ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; Symbiosis ; Urate Oxidase/*genetics ; Uric Acid/metabolism ; }, abstract = {Aphids belonging to the three genera Tuberaphis, Glyphinaphis, and Cerataphis contain extracellular fungal symbionts that resemble endocellular yeast-like symbionts of planthoppers. Whereas the symbiont of planthoppers has a uricase (urate oxidase; EC 1.7.3.3) and recycles uric acid that the host stores, no uric acid was found in Tuberaphis styraci, and its fungal symbiont did not exhibit the uricase activity. However, the fungal symbionts of these aphids, including that of T. styraci, were shown to have putative uricase genes, or pseudogenes, for the uricase. Sequence analysis of these genes revealed that deleterious mutations occurred independently on each lineage of Glyphinaphis and Tuberaphis, while no such mutation was found in the lineage of Cerataphis. These genes were almost identical to those cloned from the symbionts of planthoppers, though the host aphids and planthoppers are phylogenetically distant. To estimate the phylogenetic relationship in detail between the fungal symbionts of aphids and those of planthoppers, a gene tree was constructed based on the sequences of the uricase genes including their flanking regions. As a result, the symbionts of planthoppers and Tuberaphis aphids formed a sister group against those of Glyphinaphis and Cerataphis aphids with high bootstrap confidence levels, which strongly suggests that symbionts have been horizontally transferred from the aphids' lineage to the planthoppers'.}, }
@article {pmid11029064, year = {2000}, author = {Collins, LJ and Moulton, V and Penny, D}, title = {Use of RNA secondary structure for studying the evolution of RNase P and RNase MRP.}, journal = {Journal of molecular evolution}, volume = {51}, number = {3}, pages = {194-204}, doi = {10.1007/s002390010081}, pmid = {11029064}, issn = {0022-2844}, mesh = {Animals ; Base Sequence ; Endoribonucleases/*genetics ; *Evolution, Molecular ; Humans ; Models, Genetic ; Molecular Sequence Data ; *Nucleic Acid Conformation ; Phylogeny ; RNA, Catalytic/*chemistry/*genetics ; RNA, Ribosomal, 16S/chemistry/genetics ; Ribonuclease P ; }, abstract = {Secondary structure is evaluated for determining evolutionary relationships between catalytic RNA molecules that are so distantly related they are scarcely alignable. The ribonucleoproteins RNase P (P) and RNase MRP (MRP) have been suggested to be evolutionarily related because of similarities in both function and secondary structure. However, their RNA sequences cannot be aligned with any confidence, and this leads to uncertainty in any trees inferred from sequences. We report several approaches to using secondary structures for inferring evolutionary trees and emphasize quantitative tests to demonstrate that evolutionary information can be recovered. For P and MRP, three hypotheses for the relatedness are considered. The first is that MRP is derived from P in early eukaryotes. The next is that MRP is derived from P from an early endosymbiont. The third is that both P and MRP evolved in the RNA-world (and the need for MRP has since been lost in prokaryotes). Quantitative comparisons of the pRNA and mrpRNA secondary structures have found that the possibility of an organellar origin of MRP is unlikely. In addition, comparison of secondary structures support the identity of an RNase P-like sequence in the maize chloroplast genome. Overall, it is concluded that RNA secondary structure is useful for evaluating evolutionary relatedness, even with sequences that cannot be aligned with confidence.}, }
@article {pmid11025528, year = {2000}, author = {Karlberg, O and Canbäck, B and Kurland, CG and Andersson, SG}, title = {The dual origin of the yeast mitochondrial proteome.}, journal = {Yeast (Chichester, England)}, volume = {17}, number = {3}, pages = {170-187}, pmid = {11025528}, issn = {0749-503X}, mesh = {Alphaproteobacteria/chemistry/genetics ; Databases, Factual ; *Evolution, Molecular ; Fungal Proteins/chemistry/*genetics ; Humans ; Mitochondria/chemistry/*genetics ; Phylogeny ; Proteome/*genetics ; Rickettsia prowazekii/chemistry/genetics ; Saccharomyces cerevisiae/chemistry/*genetics ; }, abstract = {We propose a scheme for the origin of mitochondria based on phylogenetic reconstructions with more than 400 yeast nuclear genes that encode mitochondrial proteins. Half of the yeast mitochondrial proteins have no discernable bacterial homologues, while one-tenth are unequivocally of alpha-proteobacterial origin. These data suggest that the majority of genes encoding yeast mitochondrial proteins are descendants of two different genomic lineages that have evolved in different modes. First, the ancestral free-living alpha-proteobacterium evolved into an endosymbiont of an anaerobic host. Most of the ancestral bacterial genes were lost, but a small fraction of genes supporting bioenergetic and translational processes were retained and eventually transferred to what became the host nuclear genome. In a second, parallel mode, a larger number of novel mitochondrial genes were recruited from the nuclear genome to complement the remaining genes from the bacterial ancestor. These eukaryotic genes, which are primarily involved in transport and regulatory functions, transformed the endosymbiont into an ATP-exporting organelle.}, }
@article {pmid11018130, year = {2000}, author = {Spaink, HP}, title = {Root nodulation and infection factors produced by rhizobial bacteria.}, journal = {Annual review of microbiology}, volume = {54}, number = {}, pages = {257-288}, doi = {10.1146/annurev.micro.54.1.257}, pmid = {11018130}, issn = {0066-4227}, mesh = {Carbohydrate Sequence ; Cell Communication ; Fabaceae/*microbiology ; Molecular Sequence Data ; Plant Roots/*microbiology ; *Plants, Medicinal ; Polysaccharides, Bacterial ; Rhizobiaceae/*physiology ; Species Specificity ; *Symbiosis ; }, abstract = {Rhizobia are soil bacteria that can engage in a symbiosis with leguminous plants that produces nitrogen-fixing root nodules. This symbiosis is based on specific recognition of signal molecules, which are produced by both the bacterial and plant partners. In this review, recognition factors from the bacterial endosymbionts are discussed, with particular attention to secreted and cell surface glycans. Glycans that are discussed include the Nod factors, the extracellular polysaccharides, the lipopolysaccharides, the K-antigens, and the cyclic glucans. Recent advances in the understanding of the biosynthesis, secretion, and regulation of production of these glycans are reviewed, and their functions are compared with glycans produced by other bacteria, such as plant pathogens.}, }
@article {pmid11013755, year = {2001}, author = {Dunn, AM and Terry, RS and Smith, JE}, title = {Transovarial transmission in the microsporidia.}, journal = {Advances in parasitology}, volume = {48}, number = {}, pages = {57-100}, doi = {10.1016/s0065-308x(01)48005-5}, pmid = {11013755}, issn = {0065-308X}, mesh = {Animals ; Arthropods/growth &amp; development/*parasitology ; Biological Evolution ; Female ; Host-Parasite Interactions ; Male ; Microsporidia/genetics/growth &amp; development/pathogenicity/*physiology ; Microsporidiosis/parasitology/transmission ; Ovary/parasitology ; Sex Ratio ; Virulence ; }, abstract = {The microsporidia are an ancient and diverse group of protists which have many unusual characteristics. These include prokaryotic-like 70s ribosomes, enclosed nuclear division, a lack of mitochondria and complex life cycles which frequently involve vertical transmission. This use of vertical transmission is unparalleled by other protists and is seen only among bacterial endosymbionts and sex ratio distorters and in host cell organelles. Transovarially transmitted microsporidia can have unusual and profound effects on host population sex ratios. We here consider the mechanisms of transovarial transmission and its implications for parasite evolution. We review parasite/host relationships and the evolution of virulence under transovarial transmission and consider the implications of these parasites for host ecology and evolution.}, }
@article {pmid11010905, year = {2000}, author = {Bianciotto, V and Lumini, E and Lanfranco, L and Minerdi, D and Bonfante, P and Perotto, S}, title = {Detection and identification of bacterial endosymbionts in arbuscular mycorrhizal fungi belonging to the family Gigasporaceae.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {10}, pages = {4503-4509}, pmid = {11010905}, issn = {0099-2240}, mesh = {Burkholderia/*classification/isolation &amp; purification/*physiology ; DNA, Ribosomal/genetics ; Fungi/classification/isolation &amp; purification/*physiology ; In Situ Hybridization ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Spores, Fungal ; *Symbiosis ; }, abstract = {Intracellular bacteria have been found previously in one isolate of the arbuscular mycorrhizal (AM) fungus Gigaspora margarita BEG 34. In this study, we extended our investigation to 11 fungal isolates obtained from different geographic areas and belonging to six different species of the family Gigasporaceae. With the exception of Gigaspora rosea, isolates of all of the AM species harbored bacteria, and their DNA could be PCR amplified with universal bacterial primers. Primers specific for the endosymbiotic bacteria of BEG 34 could also amplify spore DNA from four species. These specific primers were successfully used as probes for in situ hybridization of endobacteria in G. margarita spores. Neighbor-joining analysis of the 16S ribosomal DNA sequences obtained from isolates of Scutellospora persica, Scutellospora castanea, and G. margarita revealed a single, strongly supported branch nested in the genus Burkholderia.}, }
@article {pmid10984505, year = {2000}, author = {Van Ham, RC and Gonzalez-Candelas, F and Silva, FJ and Sabater, B and Moya, A and Latorre, A}, title = {Postsymbiotic plasmid acquisition and evolution of the repA1-replicon in Buchnera aphidicola.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {97}, number = {20}, pages = {10855-10860}, pmid = {10984505}, issn = {0027-8424}, mesh = {Bacterial Proteins/*genetics ; Base Sequence ; Buchnera/*genetics ; DNA Replication ; *Evolution, Molecular ; Molecular Sequence Data ; Plasmids/genetics ; Replicon/genetics ; Sequence Alignment ; Symbiosis/genetics ; }, abstract = {Buchnera aphidicola is an obligate, strictly vertically transmitted, bacterial symbiont of aphids. It supplies its host with essential amino acids, nutrients required by aphids but deficient in their diet of plant phloem sap. Several lineages of Buchnera show adaptation to their nutritional role in the form of plasmid-mediated amplification of key-genes involved in the biosynthesis of tryptophan (trpEG) and leucine (leuABCD). Phylogenetic analyses of these plasmid-encoded functions have thus far suggested the absence of horizontal plasmid exchange among lineages of Buchnera. Here, we describe three new Buchnera plasmids, obtained from species of the aphid host families Lachnidae and Pemphigidae. All three plasmids belong to the repA1 family of Buchnera plasmids, which is characterized by the presence of a repA1-replicon responsible for replication initiation. A comprehensive analysis of this family of plasmids unexpectedly revealed significantly incongruent phylogenies for different plasmid and chromosomally encoded loci. We infer from these incongruencies a case of horizontal plasmid transfer in Buchnera. This process may have been mediated by secondary endosymbionts, which occasionally undergo horizontal transmission in aphids.}, }
@article {pmid10983826, year = {2000}, author = {Wernegreen, JJ and Moran, NA}, title = {Decay of mutualistic potential in aphid endosymbionts through silencing of biosynthetic loci: Buchnera of Diuraphis.}, journal = {Proceedings. Biological sciences}, volume = {267}, number = {1451}, pages = {1423-1431}, pmid = {10983826}, issn = {0962-8452}, mesh = {Animals ; *Anthranilate Synthase ; Aphids/*microbiology ; Base Sequence ; Buchnera/*genetics ; DNA, Bacterial ; *Gene Silencing ; *Genes, Bacterial ; Molecular Sequence Data ; Nitrogenous Group Transferases/*genetics ; Pseudogenes ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {Buchnera, the primary bacterial endosymbiont of aphids, is known to provision essential amino acids lacking in the hosts' diet of plant sap. The recent discovery of silenced copies of genes for tryptophan biosynthesis (trpEG) in certain Buchnera lineages suggests a decay in symbiotic functions in some aphid species. However, neither the distribution of pseudogenes among lineages nor the impact of this gene silencing on amino-acid availability in hosts has been assessed. In Buchnera of the aphid Diuraphis noxia, tandem repeats of these pseudogenes have persisted in diverse lineages, and thpEG pseudogenes have originated at least twice within this aphid genus. Measures of amino-acid concentrations in Diuraphis species have shown that the presence of the pseudogene is associated with a decreased availability of tryptophan, indicating that gene silencing decreases nutrient provisioning by symbionts. In Buchnera of Diuraphis, rates of nonsynonymous substitutions are elevated in functional trpE copies, supporting the hypothesis that pseudogene origin and persistence reflect a reduced selection for symbiont biosynthetic contributions. The parallel evolution of trpEG pseudogenes in Buchnera of Diuraphis and certain other aphid hosts suggests that either selection at the host level is not effective or that fitness in these aphids is not limited by tryptophan availability.}, }
@article {pmid10977900, year = {2000}, author = {Thao, ML and Clark, MA and Baumann, L and Brennan, EB and Moran, NA and Baumann, P}, title = {Secondary endosymbionts of psyllids have been acquired multiple times.}, journal = {Current microbiology}, volume = {41}, number = {4}, pages = {300-304}, doi = {10.1007/s002840010138}, pmid = {10977900}, issn = {0343-8651}, mesh = {Animals ; Bacteria/classification/*genetics ; Base Sequence ; DNA, Bacterial/genetics ; Enterobacteriaceae/genetics ; Hemiptera/*microbiology ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/analysis ; RNA, Ribosomal, 23S/analysis ; Symbiosis ; }, abstract = {Previous studies have established that psyllids (Hemiptera, Psylloidea) contain primary endosymbionts, designated as Carsonella ruddii, which cospeciate with the psyllid host. This association appears to be the consequence of a single infection of a psyllid ancestor with a bacterium. Some psyllids may have additional secondary (S-) endosymbionts. We have cloned and sequenced the 16S-23S ribosomal RNA genes of seven representative psyllid S-endosymbionts. Comparison of the S-endosymbiont phylogenetic trees with those of C. ruddii indicates a lack of congruence, a finding consistent with multiple infections of psyllids with different precursors of the S-endosymbionts and/or possible horizontal transmission. Additional comparisons indicate that the S-endosymbionts are related to members of the Enterobacteriaceae as well as to several other endosymbionts and insect-associated bacteria.}, }
@article {pmid10946109, year = {2000}, author = {Zerges, W}, title = {Translation in chloroplasts.}, journal = {Biochimie}, volume = {82}, number = {6-7}, pages = {583-601}, doi = {10.1016/s0300-9084(00)00603-9}, pmid = {10946109}, issn = {0300-9084}, mesh = {Chloroplasts/genetics/*metabolism ; *Protein Biosynthesis ; }, abstract = {The discovery that chloroplasts have semi-autonomous genetic systems has led to many insights into the biogenesis of these organelles and their evolution from free-living photosynthetic bacteria. Recent developments of our understanding of the molecular mechanisms of translation in chloroplasts suggest selective pressures that have maintained the 100-200 genes of the ancestral endosymbiont in chloroplast genomes. The ability to introduce modified genes into chloroplast genomes by homologous recombination and the recent development of an in vitro chloroplast translation system have been exploited for analyses of the cis-acting requirements for chloroplast translation. Trans-acting translational factors have been identified by genetic and biochemical approaches. Several studies have suggested that chloroplast mRNAs are translated in association with membranes.}, }
@article {pmid10937228, year = {2000}, author = {Clark, MA and Moran, NA and Baumann, P and Wernegreen, JJ}, title = {Cospeciation between bacterial endosymbionts (Buchnera) and a recent radiation of aphids (Uroleucon) and pitfalls of testing for phylogenetic congruence.}, journal = {Evolution; international journal of organic evolution}, volume = {54}, number = {2}, pages = {517-525}, doi = {10.1111/j.0014-3820.2000.tb00054.x}, pmid = {10937228}, issn = {0014-3820}, mesh = {Animals ; Aphids/classification/genetics/*microbiology ; Buchnera/*physiology ; Likelihood Functions ; *Phylogeny ; Species Specificity ; Symbiosis ; }, abstract = {Previous studies of phylogenetic congruence between aphids and their symbiotic bacteria (Buchnera) supported long-term vertical transmission of symbionts. However, those studies were based on distantly related aphids and would not have revealed horizontal transfer of symbionts among closely related hosts. Aphid species of the genus Uroleucon are closely related phylogenetically and overlap in geographic ranges, habitats, and parasitoids. To examine support for congruence of phylogenies of Buchnera and Uroleucon, sequences from four mitochondrial, one nuclear, and one endosymbiont gene (trpB) were obtained. Congruence of phylogenies based on pooled aphid genes with phylogenies based on trpB was highly significant: Most nodes resolved by trpB corresponded to nodes resolved by the pooled aphid genes. Furthermore, no nodes were both inconsistent between the trees and strongly supported in both trees. Two kinds of analyses testing the null hypothesis of perfect congruence between pairwise combinations of datasets and tree topologies were performed: the Kishino-Hasegawa test and the likelihood-ratio test. Both tests indicated significant disagreement among most pairwise combinations of mitochondrial, nuclear, and symbiont datasets. Because rampant recombination among mitochondrial genomes of different aphid species is unlikely, inaccurate assumptions in the evolutionary models underlying these tests appear to be causing the hypothesis of a shared history to be incorrectly rejected. Moreover, trpB was more consistent with the aphid genes as a set than any single aphid gene was with the others, suggesting that the symbionts show the same phylogeny as the aphids. Overall, analyses support the interpretation that symbionts and aphids have undergone strict cospeciation, with no horizontal transmission of symbionts even among closely related, ecologically similar aphid hosts.}, }
@article {pmid10919785, year = {2000}, author = {Nakabachi, A and Ishikawa, H}, title = {Polyamine composition and expression of genes related to polyamine biosynthesis in an aphid endosymbiont, Buchnera.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {8}, pages = {3305-3309}, pmid = {10919785}, issn = {0099-2240}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*genetics/*metabolism ; Gene Expression ; Genes, Bacterial ; Polyamines/analysis/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Spermidine/metabolism ; *Symbiosis ; }, abstract = {Polyamine composition in an aphid endosymbiotic bacterium, Buchnera sp., was determined by high-performance liquid chromatographic analysis. We found that Buchnera contained virtually only a single polyamine, spermidine. The spermidine content of Buchnera was considerably higher in young aphids and tended to decrease with the age of the host. Expression of speD and speE, whose gene products are key enzymes in the synthesis of spermidine, was analyzed by real-time quantitative reverse transcription-PCR. It was shown that the levels of their mRNAs fluctuated in line with the spermidine content.}, }
@article {pmid10908848, year = {2000}, author = {Le Pennec, M and Beninger, PG}, title = {Reproductive characteristics and strategies of reducing-system bivalves.}, journal = {Comparative biochemistry and physiology. Part A, Molecular &amp; integrative physiology}, volume = {126}, number = {1}, pages = {1-16}, doi = {10.1016/s0742-8413(00)00100-6}, pmid = {10908848}, issn = {1095-6433}, mesh = {Animals ; Bacteria/metabolism ; Environment ; Germ Cells/physiology ; Larva/growth &amp; development/physiology ; Mollusca/*physiology ; Oxidation-Reduction ; Reducing Agents/*metabolism ; Reproduction/physiology ; Rickettsiaceae/metabolism ; }, abstract = {The reproductive biology of Type 3 reducing-system bivalves (those whose pallial cavity is irrigated with water rich in reducing substances) is reviewed, with respect to size-at-maturity, sexuality, reproductive cycle, gamete size, symbiont transmission, and larval development/dispersal strategies. The pattern which emerges from the fragmentary data is that these organisms present reproductive particularities associated with their habitat, and with their degree of reliance on bacterial endosymbionts. A partial exception to this pattern is the genus Bathymodiolus, which also presents fewer trophic adaptations to the reducing environment, suggesting a bivalent adaptive strategy. A more complete understanding of the reproductive biology of Type 3 bivalves requires much more data, which may not be feasible for some aspects in the deep-sea species.}, }
@article {pmid10890444, year = {2000}, author = {Gustafson, DE and Stoecker, DK and Johnson, MD and Van Heukelem, WF and Sneider, K}, title = {Cryptophyte algae are robbed of their organelles by the marine ciliate Mesodinium rubrum.}, journal = {Nature}, volume = {405}, number = {6790}, pages = {1049-1052}, doi = {10.1038/35016570}, pmid = {10890444}, issn = {0028-0836}, mesh = {Animals ; Chlorophyll/metabolism ; Ciliophora/*physiology ; Eukaryota/*physiology ; *Organelles ; Photosynthesis ; Phytoplankton/*physiology ; *Symbiosis ; }, abstract = {Mesodinium rubrum (Lohmann 1908) Jankowski 1976 (= Myrionecta rubra) is a common photosynthetic marine planktonic ciliate which can form coastal red-tides. It may represent a 'species complex' and since Darwin's voyage on the Beagle, it has been of great cytological, physiological and evolutionary interest. It is considered to be functionally a phytoplankter because it was thought to have lost the capacity to feed and possesses a highly modified algal endosymbiont. Whether M. rubrum is the result of a permanent endosymbiosis or a transient association between a ciliate and an alga is controversial. We conducted 'feeding' experiments to determine how exposure to a cryptophyte alga affects M. rubrum. Here we show that although M. rubrum lacks a cytostome (oral cavity), it ingests cryptophytes and steals their organelles, and may not maintain a permanent endosymbiont. M. rubrum does not fall into recognized cellular or functional categories, but may be a chimaera partially supported by organelle robbery.}, }
@article {pmid10877784, year = {2000}, author = {Thao, ML and Moran, NA and Abbot, P and Brennan, EB and Burckhardt, DH and Baumann, P}, title = {Cospeciation of psyllids and their primary prokaryotic endosymbionts.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {7}, pages = {2898-2905}, pmid = {10877784}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; Cloning, Molecular ; DNA, Ribosomal/genetics ; Genes, Insect/genetics ; Hemiptera/*classification/genetics/*microbiology/physiology ; Insect Proteins/genetics/metabolism ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Psyllids are plant sap-feeding insects that harbor prokaryotic endosymbionts in specialized cells within the body cavity. Four-kilobase DNA fragments containing 16S and 23S ribosomal DNA (rDNA) were amplified from the primary (P) endosymbiont of 32 species of psyllids representing three psyllid families and eight subfamilies. In addition, 0.54-kb fragments of the psyllid nuclear gene wingless were also amplified from 26 species. Phylogenetic trees derived from 16S-23S rDNA and from the host wingless gene are very similar, and tests of compatibility of the data sets show no significant conflict between host and endosymbiont phylogenies. This result is consistent with a single infection of a shared psyllid ancestor and subsequent cospeciation of the host and the endosymbiont. In addition, the phylogenies based on DNA sequences generally agreed with psyllid taxonomy based on morphology. The 3' end of the 16S rDNA of the P endosymbionts differs from that of other members of the domain Bacteria in the lack of a sequence complementary to the mRNA ribosome binding site. The rate of sequence change in the 16S-23S rDNA of the psyllid P endosymbiont was considerably higher than that of other bacteria, including other fast-evolving insect endosymbionts. The lineage consisting of the P endosymbionts of psyllids was given the designation Candidatus Carsonella (gen. nov.) with a single species, Candidatus Carsonella ruddii (sp. nov.).}, }
@article {pmid10856373, year = {2000}, author = {Bazzocchi, C and Jamnongluk, W and O'Neill, SL and Anderson, TJ and Genchi, C and Bandi, C}, title = {wsp gene sequences from the Wolbachia of filarial nematodes.}, journal = {Current microbiology}, volume = {41}, number = {2}, pages = {96-100}, doi = {10.1007/s002840010100}, pmid = {10856373}, issn = {0343-8651}, support = {AI40620/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Outer Membrane Proteins/*genetics ; Brugia malayi/microbiology ; Cloning, Molecular ; DNA Primers ; Dirofilaria/microbiology ; *Genes, Bacterial ; Molecular Sequence Data ; Nematoda/*microbiology ; Phylogeny ; Symbiosis/genetics ; Wolbachia/chemistry/*genetics ; Wuchereria bancrofti/microbiology ; }, abstract = {Wolbachia endosymbiotic bacteria are widespread in arthropods and are also present in filarial nematodes. Almost all filarial species so far examined have been found to harbor these endosymbionts. The sequences of only three genes have been published for nematode Wolbachia (i.e., the genes coding for the proteins FtsZ and catalase and for 16S rRNA). Here we present the sequences of the genes coding for the Wolbachia surface protein (WSP) from the endosymbionts of eight species of filaria. Complete gene sequences were obtained from the endosymbionts of two different species, Dirofilaria immitis and Brugia malayi. These sequences allowed us to design general primers for amplification of the wsp gene from the Wolbachia of all filarial species examined. For these species, partial WSP sequences (about 600 base pairs) were obtained with these primers. Phylogenetic analysis groups these nematode wsp sequences into a coherent cluster. Within the nematode cluster, wsp-based Wolbachia phylogeny matches a previous phylogeny obtained with ftsZ gene sequences, with a good consistency of the phylogeny of hosts (nematodes) and symbionts (Wolbachia). In addition, different individuals of the same host species (Dirofilaria immitis and Wuchereria bancrofti) show identical wsp gene sequences.}, }
@article {pmid10856303, year = {2000}, author = {Que, NL and Lin, S and Cotter, RJ and Raetz, CR}, title = {Purification and mass spectrometry of six lipid A species from the bacterial endosymbiont Rhizobium etli. Demonstration of a conserved distal unit and a variable proximal portion.}, journal = {The Journal of biological chemistry}, volume = {275}, number = {36}, pages = {28006-28016}, pmid = {10856303}, issn = {0021-9258}, support = {R37 GM051796/GM/NIGMS NIH HHS/United States ; R37 GM051796-05/GM/NIGMS NIH HHS/United States ; R37-GM-51796/GM/NIGMS NIH HHS/United States ; GM-54882/GM/NIGMS NIH HHS/United States ; }, mesh = {Carbohydrate Conformation ; Carbohydrate Sequence ; Chromatography, Ion Exchange ; Chromatography, Thin Layer ; Escherichia coli/chemistry ; Lipid A/biosynthesis/*chemistry/isolation &amp; purification ; Mass Spectrometry ; Molecular Conformation ; Molecular Sequence Data ; Rhizobium/*chemistry/physiology ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Symbiosis ; }, abstract = {Lipid A of Rhizobium etli CE3 differs dramatically from that of other Gram-negative bacteria. Key features include the presence of an unusual C28 acyl chain, a galacturonic acid moiety at position 4', and an acylated aminogluconate unit in place of the proximal glucosamine. In addition, R. etli lipid A is reported to lack phosphate and acyloxyacyl residues. Most of these remarkable structural claims are consistent with our recent enzymatic studies. However, the proposed R. etli lipid A structure is inconsistent with the ability of the precursor (3-deoxy-D-manno-octulosonic acid)(2)-4'-(32)P-lipid IV(A) to accept a C28 chain in vitro (Brozek, K. A., Carlson, R. W., and Raetz, C. R. H. (1996) J. Biol. Chem. 271, 32126-32136). To re-evaluate the structure, CE3 lipid A was isolated by new chromatographic procedures. CE3 lipid A is now resolved into six related components. Aminogluconate is present in D-1, D-2, and E, whereas B and C contain the typical glucosamine disaccharide seen in lipid A of most other bacteria. All the components possess a peculiar acyloxyacyl moiety at position 2', which includes the ester-linked C28 chain. As judged by mass spectrometry, the distal glucosamine units of A through E are the same, but the proximal units are variable. As described in the accompanying article (Que, N. L. S., Ribeiro, A. A., and Raetz, C. R. H. (2000) J. Biol. Chem. 275, 28017-28027), the discovery of component B suggests a plausible enzymatic pathway for the biosynthesis of the aminogluconate residue found in species D-1, D-2, and E of R. etli lipid A. We suggest that the unusual lipid A species of R. etli might be essential during symbiosis with leguminous host plants.}, }
@article {pmid10851160, year = {2000}, author = {Moran, NA and Baumann, P}, title = {Bacterial endosymbionts in animals.}, journal = {Current opinion in microbiology}, volume = {3}, number = {3}, pages = {270-275}, doi = {10.1016/s1369-5274(00)00088-6}, pmid = {10851160}, issn = {1369-5274}, mesh = {Animals ; Bacteria/*genetics/metabolism ; *Biological Evolution ; Plasmids/physiology ; Symbiosis/*physiology ; }, abstract = {Molecular phylogenetic studies reveal that many endosymbioses between bacteria and invertebrate hosts result from ancient infections followed by strict vertical transmission within host lineages. Endosymbionts display a distinctive constellation of genetic properties including AT-biased base composition, accelerated sequence evolution, and, at least sometimes, small genome size; these features suggest increased genetic drift. Molecular genetic characterization also has revealed adaptive, host-beneficial traits such as amplification of genes underlying nutrient provision.}, }
@article {pmid10833226, year = {2000}, author = {Ruiz-Lozano, JM and Bonfante, P}, title = {A Burkholderia Strain Living Inside the Arbuscular Mycorrhizal Fungus Gigaspora margarita Possesses the vacB Gene, Which Is Involved in Host Cell Colonization by Bacteria.}, journal = {Microbial ecology}, volume = {39}, number = {2}, pages = {137-144}, doi = {10.1007/s002480000008}, pmid = {10833226}, issn = {1432-184X}, abstract = {The arbuscular mycorrhizal (AM) fungus Gigaspora margarita harbors a resident population of endosymbiontic Burkholderia in its cytoplasm. Nothing is known about the acquisition of such bacteria and about the molecular bases which allow colonization of the fungus. We wondered whether the intracellular Burkholderia strain possesses genetic determinants involved in colonization of a eukaryotic cell. Using degenerated oligonucleotide primers for vacB, a gene involved in host cell colonization by pathogenic bacteria, an 842 bp DNA fragment was cloned, sequenced, and identified as a part of the vacB gene in Burkholderia sp. The insert was used as a probe to screen a fungal library that, because of the presence of intracellular Burkholderia cells, was also representative of the bacterial genome. The complete nucleotide sequence of vacB and flanking genes was determined. The bacterial origin of this genomic region was established by PCR, using specific vacB primers on DNA from Gigasporaceae that did or did not contain cytoplasmic Burkholderia, as well as on DNA from other bacteria, including free-living Burkholderia. We hypothesize that the vacB gene is part of a new genetic region acquired by a rhizospheric Burkholderia strain, which became able to establish a symbiotic interaction with the AM fungus G. margarita.}, }
@article {pmid10831445, year = {2000}, author = {Fritsche, TR and Horn, M and Wagner, M and Herwig, RP and Schleifer, KH and Gautom, RK}, title = {Phylogenetic diversity among geographically dispersed Chlamydiales endosymbionts recovered from clinical and environmental isolates of Acanthamoeba spp.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {6}, pages = {2613-2619}, pmid = {10831445}, issn = {0099-2240}, support = {F06 TW002279/TW/FIC NIH HHS/United States ; F06 TW02279-01/TW/FIC NIH HHS/United States ; }, mesh = {Acanthamoeba/*microbiology/ultrastructure ; Acanthamoeba Keratitis/parasitology ; Animals ; Chlamydiales/*genetics/isolation &amp; purification/ultrastructure ; Environmental Microbiology ; Genes, rRNA ; *Genetic Variation ; In Situ Hybridization, Fluorescence ; Molecular Sequence Data ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The recently proposed reorganization of the order Chlamydiales and description of new taxa are broadening our perception of this once narrowly defined taxon. We have recovered four strains of gram-negative cocci endosymbiotic in Acanthamoeba spp., representing 5% of the Acanthamoeba sp. isolates examined, which displayed developmental life cycles typical of members of the Chlamydiales. One of these endosymbiont strains was found stably infecting an amoebic isolate recovered from a case of amoebic keratitis in North America, with three others found in acanthamoebae recovered from environmental sources in North America (two isolates) and Europe (one isolate). Analyses of nearly full-length 16S rRNA gene sequences of these isolates by neighbor joining, parsimony, and distance matrix methods revealed their clustering with other members of the Chlamydiales but in a lineage separate from those of the genera Chlamydia, Chlamydophila, Simkania, and Waddlia (sequence similarities, <88%) and including the recently described species Parachlamydia acanthamoebae (sequence similarities, 91.2 to 93.1%). With sequence similarities to each other of 91.4 to 99.4%, these four isolates of intra-amoebal endosymbionts may represent three distinct species and, perhaps, new genera within the recently proposed family Parachlamydiaceae. Fluorescently labeled oligonucleotide probes targeted to 16S rRNA signature regions were able to readily differentiate two groups of intra-amoebal endosymbionts which corresponded to two phylogenetic lineages. These results reveal significant phylogenetic diversity occurring among the Chlamydiales in nontraditional host species and supports the existence of a large environmental reservoir of related species. Considering that all described species of Chlamydiales are known to be pathogenic, further investigation of intra-amoebal parachlamydiae as disease-producing agents is warranted.}, }
@article {pmid10817144, year = {1999}, author = {Simpson, SJ and Raubenheimer, D}, title = {Assuaging nutritional complexity: a geometrical approach.}, journal = {The Proceedings of the Nutrition Society}, volume = {58}, number = {4}, pages = {779-789}, doi = {10.1017/s0029665199001068}, pmid = {10817144}, issn = {0029-6651}, mesh = {*Animal Nutritional Physiological Phenomena ; Animals ; Behavior, Animal ; Biological Evolution ; Eating ; Ecology ; Homeostasis ; Mathematics ; Models, Biological ; Nutritional Requirements ; Phylogeny ; }, abstract = {We have introduced a framework that enables the identification of the important elements in complex nutritional systems, and the quantification of the interactions among them. These interactions include those among the multiple constituents of the ingesta, as well as between behavioural (ingestive) and physiological (post-ingestive) components of nutritional homeostasis. The resulting descriptions provide a powerful means to generate and test hypotheses concerning the mechanisms, ecology and evolution of nutritional systems. We provide an overview of the key concepts involved in our scheme, and then introduce four examples in which the framework is used to develop and test hypotheses. In the first example we use comparative methods based on a data set of 117 insect species to test a prediction about the relationship between evolving an association with bacterial endosymbionts and the composition of the optimal diet. Second, using two species of locusts (a grass specialist and a generalist), we consider the relationship between an animal's diet breadth and the decision rules employed when feeding on foods containing suboptimal protein: carbohydrate values. Third, we introduce a mathematical model that predicts the dose-response properties of gustatory systems in the context of nutritional homeostasis. Finally, we consider the interaction between tannic acid and macronutrient balance in the diet of locusts.}, }
@article {pmid10781569, year = {2000}, author = {Jiménez, N and González-Candelas, F and Silva, FJ}, title = {Prephenate dehydratase from the aphid endosymbiont (Buchnera) displays changes in the regulatory domain that suggest its desensitization to inhibition by phenylalanine.}, journal = {Journal of bacteriology}, volume = {182}, number = {10}, pages = {2967-2969}, pmid = {10781569}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Base Sequence ; Binding Sites ; Buchnera/*enzymology/genetics ; Chorismate Mutase/*genetics ; DNA, Bacterial ; Enzyme Inhibitors ; Escherichia coli/genetics ; Genome, Bacterial ; Humans ; Molecular Sequence Data ; Phenylalanine/*metabolism ; Prephenate Dehydratase/*genetics ; Sequence Homology, Amino Acid ; *Symbiosis ; }, abstract = {Buchnera aphidicola, the prokaryotic endosymbiont of aphids, complements dietary deficiencies with the synthesis and provision of several essential amino acids. We have cloned and sequenced a region of the genome of B. aphidicola isolated from Acyrthosiphon pisum which includes the two-domain aroQ/pheA gene. This gene encodes the bifunctional chorismate mutase-prephenate dehydratase protein, which plays a central role in L-phenylalanine biosynthesis. Two changes involved in the overproduction of this amino acid have been detected. First, the absence of an attenuator region suggests a constitutive expression of this gene. Second, the regulatory domain of the Buchnera prephenate dehydratase shows changes in the ESRP sequence, which is involved in the allosteric binding of phenylalanine and is strongly conserved in prephenate dehydratase proteins from practically all known organisms. These changes suggest the desensitization of the enzyme to inhibition by phenylalanine and would permit the bacterial endosymbiont to overproduce phenylalanine.}, }
@article {pmid10775590, year = {2000}, author = {Hogenhout, SA and van der Wilk, F and Verbeek, M and Goldbach, RW and van den Heuvel, JF}, title = {Identifying the determinants in the equatorial domain of Buchnera GroEL implicated in binding Potato leafroll virus.}, journal = {Journal of virology}, volume = {74}, number = {10}, pages = {4541-4548}, pmid = {10775590}, issn = {0022-538X}, mesh = {Alanine/chemistry/metabolism ; Amino Acid Sequence ; Amino Acid Substitution ; Amino Acids/chemistry ; Animals ; Aphids/*microbiology ; Binding Sites ; Buchnera/genetics/*metabolism ; Chaperonin 60/chemistry/genetics/*metabolism ; Gene Deletion ; Luteovirus/*metabolism ; Models, Molecular ; Molecular Sequence Data ; Mutation ; Protein Structure, Tertiary ; Sequence Alignment ; Solanum tuberosum/virology ; }, abstract = {Luteoviruses avoid degradation in the hemolymph of their aphid vector by interacting with a GroEL homolog from the aphid's primary endosymbiotic bacterium (Buchnera sp.). Mutational analysis of GroEL from the primary endosymbiont of Myzus persicae (MpB GroEL) revealed that the amino acids mediating binding of Potato leafroll virus (PLRV; Luteoviridae) are located within residues 9 to 19 and 427 to 457 of the N-terminal and C-terminal regions, respectively, of the discontinuous equatorial domain. Virus overlay assays with a series of overlapping synthetic decameric peptides and their derivatives demonstrated that R13, K15, L17, and R18 of the N-terminal region and R441 and R445 of the C-terminal region of the equatorial domain of GroEL are critical for PLRV binding. Replacement of R441 and R445 by alanine in full-length MpB GroEL and in MpB GroEL deletion mutants reduced but did not abolish PLRV binding. Alanine substitution of either R13 or K15 eliminated the PLRV-binding capacity of the other and those of L17 and R18. In the predicted tertiary structure of GroEL, the determinants mediating virus binding are juxtaposed in the equatorial plain.}, }
@article {pmid10770808, year = {2000}, author = {Taylor, MJ and Cross, HF and Bilo, K}, title = {Inflammatory responses induced by the filarial nematode Brugia malayi are mediated by lipopolysaccharide-like activity from endosymbiotic Wolbachia bacteria.}, journal = {The Journal of experimental medicine}, volume = {191}, number = {8}, pages = {1429-1436}, pmid = {10770808}, issn = {0022-1007}, mesh = {Animals ; Brugia malayi/*microbiology/*pathogenicity ; Cell Line ; Culicidae ; Filariasis/*etiology ; Humans ; Inflammation/*etiology ; Inflammation Mediators/isolation &amp; purification/toxicity ; Lipopolysaccharides/isolation &amp; purification/toxicity ; Mice ; Mice, Inbred C3H ; Symbiosis ; Wolbachia/*pathogenicity ; }, abstract = {The pathogenesis of filarial disease is characterized by acute and chronic inflammation. Inflammatory responses are thought to be generated by either the parasite, the immune response, or opportunistic infection. We show that soluble extracts of the human filarial parasite Brugia malayi can induce potent inflammatory responses, including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and nitric oxide (NO) from macrophages. The active component is heat stable, reacts positively in the Limulus amebocyte lysate assay, and can be inhibited by polymyxin B. TNF-alpha, IL-1beta, and NO responses were not induced in macrophages from lipopolysaccharide (LPS)-nonresponsive C3H/HeJ mice. The production of TNF-alpha after chemotherapy of microfilariae was also only detected in LPS-responsive C3H/HeN mice, suggesting that signaling through the Toll-like receptor 4 (TLR4) is necessary for these responses. We also show that CD14 is required for optimal TNF-alpha responses at low concentrations. Together, these results suggest that extracts of B. malayi contain bacterial LPS. Extracts from the rodent filaria, Acanthocheilonema viteae, which is not infected with the endosymbiotic Wolbachia bacteria found in the majority of filarial parasites, failed to induce any inflammatory responses from macrophages, suggesting that the source of bacterial LPS in extracts of B. malayi is the Wolbachia endosymbiont. Wolbachia extracts derived from a mosquito cell line induced similar LPS-dependent TNF-alpha and NO responses from C3H/HeN macrophages, which were eliminated after tetracycline treatment of the bacteria. Thus, Wolbachia LPS may be one of the major mediators of inflammatory pathogenesis in filarial nematode disease.}, }
@article {pmid10768471, year = {2000}, author = {Jeanthon, C}, title = {Molecular ecology of hydrothermal vent microbial communities.}, journal = {Antonie van Leeuwenhoek}, volume = {77}, number = {2}, pages = {117-133}, doi = {10.1023/a:1002463825025}, pmid = {10768471}, issn = {0003-6072}, mesh = {Animals ; Archaea/classification ; *Ecosystem ; Evolution, Molecular ; Hot Temperature ; Invertebrates/microbiology ; Lipids/analysis ; Nucleic Acid Hybridization ; Proteobacteria/classification ; Seawater/*microbiology ; Symbiosis ; }, abstract = {The study of the structure and diversity of hydrothermal vent microbial communities has long been restricted to the morphological description of microorganisms and the use of enrichment culture-based techniques. Until recently the identification of the culturable fraction required the isolation of pure cultures followed by testing for multiple physiological and biochemical traits. However, peculiar inhabitants of the hydrothermal ecosystem such as the invertebrate endosymbionts and the dense microbial mat filaments have eluded laboratory cultivation. Substantial progress has been achieved in recent years in techniques for the identification of microorganisms in natural environments. Application of molecular approaches has revealed the existence of unique and previously unrecognized microorganisms. These have provided fresh insight into the ecology, diversity and evolution of mesophilic and thermophilic microbial communities from the deep-sea hydrothermal ecosystem. This review reports the main discoveries made through the introduction of these powerful techniques in the study of deep-sea hydrothermal vent microbiology.}, }
@article {pmid16465265, year = {1997}, author = {Kroemer, G}, title = {Mitochondrial implication in apoptosis. Towards an endosymbiont hypothesis of apoptosis evolution.}, journal = {Cell death and differentiation}, volume = {4}, number = {6}, pages = {443-456}, doi = {10.1038/sj.cdd.4400266}, pmid = {16465265}, issn = {1350-9047}, abstract = {Recent evidence indicates that a profound alteration in mitochondrial function constitutes an obligatory early event of the apoptotic process. The molecular mechanism accounting for this alteration is mitochondrial permeability transition (PT). PT is both sufficient and necessary for apoptosis to occur. Experiments performed in cell-free systems of apoptosis demonstrate that mitochondria undergoing PT release protease activators that can trigger nuclear manifestations of apoptosis. Bcl-2 and its homologs are endogenous regulators of PT. It appears that some types of necrosis, those inhibited by Bcl-2, involve PT. If PT is a rate-limiting event of both apoptosis and necrosis, then downstream events including caspase activation and the bioenergetic consequences of PT must determine the choice between both modes of cell death. PT without caspase activation would cause necrosis. These findings have important implications for the comprehension of the apoptotic process, for the dichotomy between apoptosis and necrosis, and for the phylogeny of programmed cell death. Apoptosis may have evolved together with the endosymbiotic incorporation of aerobic bacteria (the precursors of mitochondria) into ancestral unicellular eukaryotes.}, }
@article {pmid18811258, year = {1997}, author = {Clancy, DJ and Hoffmann, AA}, title = {Behavior of Wolbachia endosymbionts from Drosophila simulans in Drosophila serrata, a novel host.}, journal = {The American naturalist}, volume = {149}, number = {5}, pages = {975-988}, doi = {10.1086/286033}, pmid = {18811258}, issn = {0003-0147}, abstract = {Many species harbor the incompatibility-inducing microbe Wolbachia, a maternally inherited endoparasite that causes reduced egg hatch in crosses between infected males and uninfected females. Infected females are immune to this effect, which gives them a relative fitness advantage that results in the spread of the infection. The strength of incompatibility, fitness deficits associated with the infection, and transmission rate from mother to offspring largely determine the rate and extent of spread of Wolbachia in a population. We transferred Wolbachia from Drosophila simulans to Drosophila serrata, a novel host, and compared parameter estimates with those from three naturally occurring Drosophila-Wolbachia associations believed to be of different ages. Transfected D. serrata showed strong incompatibility, low transmission efficiency, and an associated fitness deficit, and they would probably be unable to spread in nature. The comparisons generally supported the predicted evolution of a host-Wolbachia association. The parameters peculiar to any given host-Wolbachia association may determine whether the microbial strain can spread in that host.}, }
@article {pmid16031855, year = {1995}, author = {Clark, JM}, title = {The diet of the parasitic mite Trichosurolaelaps crassipes Womersley, 1956 and its potential to act as a disease vector.}, journal = {New Zealand veterinary journal}, volume = {43}, number = {6}, pages = {215-218}, doi = {10.1080/00480169.1995.35895}, pmid = {16031855}, issn = {0048-0169}, abstract = {The anatomy of the gaster of Trichosurolaelaps crassipes is illustrated. Protonymphs, deutonymphs and adults were all seen with a scarlet gut and gave strongly positive results to occult blood tests. Host blood cells were identified in a gut smear from a female mite. An adult female gut could hold about 7.1 x 10(-6) ml. The mite was seen frequenting small open skin lesions. Gram-negative bacteria identified in the mite's gut are most likely to be endosymbionts. Mite larvae have their gastric caeca invaded by these bacteria before birth. There is a potential for this mite to act as a weak vector of disease from one possum to another.}, }
@article {pmid11539474, year = {1995}, author = {Duval, B and Margulis, L}, title = {The microbial community of Ophrydium versatile colonies: endosymbionts, residents, and tenants.}, journal = {Symbiosis (Philadelphia, Pa.)}, volume = {18}, number = {}, pages = {181-210}, pmid = {11539474}, issn = {0334-5114}, mesh = {Animals ; Bacteria/growth &amp; development ; Chlorophyta ; Diatoms/growth &amp; development ; Ecosystem ; Fresh Water ; Light ; Massachusetts ; Oligohymenophorea/cytology/growth &amp; development/*microbiology ; Seasons ; *Symbiosis ; *Water Microbiology ; }, abstract = {Ophrydium versatile is a sessile peritrichous ciliate (Kingdom Protoctista, class Oligohymenophora, order Peritrichida, suborder Sessilina) that forms green, gelatinous colonies. Chlorophyll a and b impart a green color to Ophrydium masses due to 400-500 Chlorella-like endosymbionts in each peritrich. Ophrydium colonies, collected from two bog wetlands (Hawley and Leverett, Massachusetts) were analyzed for their gel inhabitants. Other protists include ciliates, mastigotes, euglenids, chlorophytes, and heliozoa. Routine constituents include from 50-100,000 Nitzschia per ml of gel and at least four other diatom genera (Navicula, Pinnularia, Gyrosigma, Cymbella) that may participate in synthesis of the gel matrix. Among the prokaryotes are filamentous and coccoid cyanobacteria, large rod-shaped bacteria, at least three types of spirochetes and one unidentified Saprospira-like organism. Endosymbiotic methanogenic bacteria, observed using fluorescence microscopy, were present in unidentified hypotrichous ciliates. Animals found inside the gel include rotifers, nematodes, and occasional copepods. The latter were observed in the water reservoir of larger Ophrydium masses. From 30-46% of incident visible radiation could be attenuated by Ophrydium green jelly masses in laboratory observations. Protargol staining was used to visualize the elongate macronuclei and small micronucleus of O. versatile zooids and symbiotic algal nuclei. Electron microscopic analysis of the wall of the Chlorella-like symbiont suggests that although the Ophrydium zooids from British Columbia harbor Chlorella vulgaris, those from Hawley Bog contain Graesiella sp. The growth habit in the photic zone and loose level of individuation of macroscopic Ophrydium masses are interpretable as extant analogs of certain Ediacaran biota: colonial protists in the Vendian fossil record.}, }
@article {pmid16349393, year = {1994}, author = {Baumann, L and Baumann, P}, title = {Growth Kinetics of the Endosymbiont Buchnera aphidicola in the Aphid Schizaphis graminum.}, journal = {Applied and environmental microbiology}, volume = {60}, number = {9}, pages = {3440-3443}, pmid = {16349393}, issn = {0099-2240}, abstract = {The aphid Schizaphis graminum is dependent on its prokaryotic endosymbiont, Buchnera aphidicola. As a means of determining B. aphidicola numbers during the growth cycle of the aphid we have used the quantitative PCR to measure the number of copies of rrs (the gene coding for 16S rRNA, which is present as one copy in the B. aphidicola genome). In addition we have measured the aphid wet weight and the DNA and protein content. The results indicate an approximately parallel (23- to 31-fold) increase of these properties during the period of aphid growth. A 1-day-old aphid (24 mug [wet weight]) has 0.2 x 10 copies of rrs, while a 9-day-old aphid (497 mug [wet weight]) has 5.6 x 10 copies. The coupling of endosymbiont and aphid growth is consistent with the requirement of the endosymbiont for growth and reproduction of the aphid.}, }
@article {pmid16349079, year = {1993}, author = {Ferguson, NH and Rice, JS and Allgood, NG}, title = {Variation in Nitrogen Utilization in Acremonium coenophialum Isolates.}, journal = {Applied and environmental microbiology}, volume = {59}, number = {11}, pages = {3602-3604}, pmid = {16349079}, issn = {0099-2240}, abstract = {Acremonium coenophialum, a fungal endosymbiont in tall fescue, is responsible for the production of alkaloid toxins. Animals grazing endophyte-infected tall fescue often show toxicosis. In marginal environments, the endophyte is important for long-term survival of tall fescue. Few differences in endophyte isolates from individual tall fescue plants have been reported. To aid development of a toxicosis-free tall fescue, it is important to identify differences in endophyte isolates. This report describes variation in nitrogen utilization in a defined culture medium by endophyte isolates from Kentucky-31 tall fescue. Overall, the best nitrogen sources for dry weight production of mycelium were proline and potassium nitrate. Thirty-four isolates grown on agar-solidified defined media with single nitrogen sources showed variation in nitrogen utilization. Fifty percent of the isolates were unable to utilize two or more amino acids. Manipulation of endophyte variation could lead to development of a toxicosis-free tall fescue cultivar.}, }
@article {pmid11607337, year = {1992}, author = {Iglesias-Prieto, R and Matta, JL and Robins, WA and Trench, RK}, title = {Photosynthetic response to elevated temperature in the symbiotic dinoflagellate Symbiodinium microadriaticum in culture.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {89}, number = {21}, pages = {10302-10305}, pmid = {11607337}, issn = {0027-8424}, abstract = {Elevated temperature (28-34 degrees C) has been hypothesized as the primary cause of the loss of algal endosymbionts in coral reef-associated invertebrates, a phenomenon observed on a world-wide scale over the last decade. In past studies of this "bleaching" phenomenon, there has been an underlying assumption that temperature adversely affects the animal hosts, the algae thereby being relegated to a more passive role. Because photosynthesis is a sensitive indicator of thermal stress in plants and has a central role in the nutrition of symbiotic invertebrates, we have tested the hypothesis that elevated temperature adversely affects photosynthesis in the symbiotic dinoflagellate Symbiodinium microadriaticum. The results, based on analyses of light-mediated O2 evolution and in vivo fluorescence, indicate that photosynthesis is impaired at temperatures above 30 degrees C and ceases completely at 34-36 degrees C. These observations are discussed in the context of possible mechanisms that may function in the disassociation of algal-invertebrate symbioses in response to elevated temperature.}, }
@article {pmid17773605, year = {1991}, author = {Carpenter, EJ and Romans, K}, title = {Major role of the cyanobacterium trichodesmium in nutrient cycling in the north atlantic ocean.}, journal = {Science (New York, N.Y.)}, volume = {254}, number = {5036}, pages = {1356-1358}, doi = {10.1126/science.254.5036.1356}, pmid = {17773605}, issn = {0036-8075}, abstract = {The diazotrophic cyanobacterium Trichodesmium is a large (about 0.5 by 3 millimeters) phytoplankter that is common in tropical open-ocean waters. Measurements of abundance, plus a review of earlier observations, indicate that it, rather than the picophytoplankton, is the most important primary producer (about 165 milligrams of carbon per square meter per day) in the tropical North Atlantic Ocean. Furthermore, nitrogen fixation by Trichodesmium introduces the largest fraction of new nitrogen to the euphotic zone, approximately 30 milligrams of nitrogen per square meter per day, a value exceeding the estimated flux of nitrate across the thermocline. Inclusion of this organism, plus the abundant diazotrophic endosymbiont Richelia intracellularis that is present in some large diatoms, in biogeochemical studies of carbon and nitrogen may help explain the disparity between various methods of measuring productivity in the oligotrophic ocean. Carbon and nitrogen fixation by these large phytoplankters also introduces a new paradigm in the biogeochemistry of these elements in the sea.}, }
@article {pmid16348540, year = {1991}, author = {Berk, SG and Parks, LH and Ting, RS}, title = {Photoadaptation Alters the Ingestion Rate of Paramecium bursaria, a Mixotrophic Ciliate.}, journal = {Applied and environmental microbiology}, volume = {57}, number = {8}, pages = {2312-2316}, pmid = {16348540}, issn = {0099-2240}, abstract = {Bacteriovorous protozoa harboring symbiotic algae are abundant in aquatic ecosystems, yet despite a recent interest in protozoan bacterivory, the influence of light on their ingestion rates has not been investigated. In this study, Paramecium bursaria containing endosymbiotic Chlorella was tested for the effect of light on its ingestion rate. P. bursaria was grown for 4 to 6 days under five different light fluxes ranging from 1 to 90 microeinsteins s m. Ingestion rates were determined by using 0.77-mum-diameter fluorescent microspheres. 4',6-Diamidino-2-phenylindole dihydrochloride-labeled Enterobacter cloacae was used in one experiment to confirm differences in uptake rates of bacteria by P. bursaria. Unlike phagotrophic phytoflagellates, the ciliates demonstrated different ingestion rates in response to different light intensities. Although symbionts contribute carbon to their host via photosynthesis, the paramecia of the present study fed faster after exposure to higher light intensities, whereas their aposymbiotic counterparts (lacking endosymbionts) were unaffected. Light-induced changes in ingestion rates were not immediate, but corresponded to the period of time required for endosymbiont populations to change significantly. This strongly suggests that the symbionts, stimulated by higher light levels, may dictate the feeding rates of their hosts. Thus, light, apart from temperature, may influence the impact of certain protists on natural bacteria and may affect laboratory-based determinations of protistan feeding rates.}, }
@article {pmid17816191, year = {1991}, author = {Rowan, R and Powers, DA}, title = {A molecular genetic classification of zooxanthellae and the evolution of animal-algal symbioses.}, journal = {Science (New York, N.Y.)}, volume = {251}, number = {4999}, pages = {1348-1351}, doi = {10.1126/science.251.4999.1348}, pmid = {17816191}, issn = {0036-8075}, abstract = {Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of marine invertebrate species. Because zooxanthellae have traditionally been difficult to classify, little is known about the natural history of these symbioses. Zooxanthellae were isolated from 131 individuals in 22 host taxa and characterized by the use of restriction fragment length polymorphisms (RFLPs) in nuclear genes that encode small ribosomal subunit RNA (ssRNA). Six algal RFLPs, distributed host species specifically, were detected. Individual hosts contained one algal RFLP. Zooxanthella phylogenetic relationships were estimated from 22 algal ssRNA sequences-one from each host species. Closely related algae were found in dissimilar hosts, suggesting that animal and algal lineages have maintained a flexible evolutionary relation with each other.}, }
@article {pmid16348366, year = {1990}, author = {Tang, LF and Watanabe, I and Liu, CC}, title = {Limited Multiplication of Symbiotic Cyanobacteria of Azolla spp. on Artificial Media.}, journal = {Applied and environmental microbiology}, volume = {56}, number = {11}, pages = {3623-3626}, pmid = {16348366}, issn = {0099-2240}, abstract = {We examined various media and conditions to isolate symbiotic cyanobacteria from the leaf cavities of Azolla spp. Cyanobacteria survived and multiplied to a limited extent on a medium with fructose, Casamino Acids, yeast extract, and NaNO(3) under 1% O(2). These cyanobacteria were antigenically identical to the endosymbionts.}, }
@article {pmid16348182, year = {1990}, author = {Plazinski, J and Zheng, Q and Taylor, R and Croft, L and Rolfe, BG and Gunning, BE}, title = {DNA probes show genetic variation in cyanobacterial symbionts of the azolla fern and a closer relationship to free-living nostoc strains than to free-living anabaena strains.}, journal = {Applied and environmental microbiology}, volume = {56}, number = {5}, pages = {1263-1270}, pmid = {16348182}, issn = {0099-2240}, abstract = {Twenty-two isolates of Anabaena azollae derived from seven Azolla species from various geographic and ecological sources were characterized by DNA-DNA hybridization. Cloned DNA fragments derived from the genomic sequences of three different A. azollae isolates were used to detect restriction fragment length polymorphism among all symbiotic anabaenas. DNA clones were radiolabeled and hybridized against southern blot transfers of genomic DNAs of different isolates of A. azollae digested with restriction endonucleases. Eight DNA probes were selected to identify the Anabaena strains tested. Two were strain specific and hybridized only to A. azollae strains isolated from Azolla microphylla or Azolla caroliniana. One DNA probe was section specific (hybridized only to anabaenas isolated from Azolla ferns representing the section Euazolla), and five other probes gave finer discrimination among anabaenas representing various ecotypes of Azolla species. These cloned genomic DNA probes identified 11 different genotypes of A. azollae isolates. These included three endosymbiotic genotypes within Azolla filiculoides species and two genotypes within both A. caroliniana and Azolla pinnata endosymbionts. Although we were not able to discriminate among anabaenas extracted from different ecotypes of Azolla nilotica, Azolla mexicina, Azolla rubra and Azolla microphylla species, each of the endosymbionts was easily identified as a unique genotype. When total DNA isolated from free-living Anabaena sp. strain PCC7120 was screened, none of the genomic DNA probes gave detectable positive hybridization. Total DNA of Nostoc cycas PCC7422 hybridized with six of eight genomic DNA fragments. These data imply that the dominant symbiotic organism in association with Azolla spp. is more closely related to Nostoc spp. than to free-living Anabaena spp.}, }
@article {pmid17800067, year = {1990}, author = {Fisher, CR and Kennicutt, MC and Brooks, JM}, title = {Stable carbon isotopic evidence for carbon limitation in hydrothermal vent vestimentiferans.}, journal = {Science (New York, N.Y.)}, volume = {247}, number = {4946}, pages = {1094-1096}, doi = {10.1126/science.247.4946.1094}, pmid = {17800067}, issn = {0036-8075}, abstract = {Stable carbon isotope composition (delta(13)C values) can be used to evaluate an animal's source of nutritional carbon. Most animals with chemoautotrophic endosymbionts have quite negative tissue delta(13)C values due to discrimination against (13)C associated with chemoautotrophic assimilation of inorganic carbon. However, the delta(13)C values of hydrothermal vent (HTV) vestimentiferans are significantly higher than the values reported for non-HTV vestimentiferans or other invertebrates with chemoautotrophic endosymbionts. Tissue delta(13)C values of two species of HTV vestimentiferans increase with increasing size of the animals. This relation supports the hypothesis that the relatively high delta(13)C values are the result of inorganic carbon limitation during carbon fixation. A more favorable relation between gas exchange and carbon fixation in the smaller individuals is expected, due to differences in the geometric scaling of gas-exchange surfaces and trophosome volume.}, }
@article {pmid11536580, year = {1987}, author = {Delihas, N and Fox, GE}, title = {Origins of the plant chloroplasts and mitochondria based on comparisons of 5S ribosomal RNAs.}, journal = {Annals of the New York Academy of Sciences}, volume = {503}, number = {}, pages = {92-102}, doi = {10.1111/j.1749-6632.1987.tb40601.x}, pmid = {11536580}, issn = {0077-8923}, support = {DMB 85-02213/MB/BHP HRSA HHS/United States ; NSG-7440/NS/NINDS NIH HHS/United States ; }, mesh = {Animals ; Bacteria ; *Biological Evolution ; Cyanobacteria ; Euglena gracilis ; Mitochondria/*genetics/physiology ; Plants/*genetics/ultrastructure ; *RNA, Bacterial ; *RNA, Chloroplast ; RNA, Plant ; RNA, Protozoan ; RNA, Ribosomal, 5S/classification/*genetics/physiology ; Sequence Analysis, RNA ; Sequence Homology, Nucleic Acid ; Symbiosis ; Triticum ; }, abstract = {In this paper, we provide macromolecular comparisons utilizing the 5S ribosomal RNA structure to suggest extant bacteria that are the likely descendants of chloroplast and mitochondria endosymbionts. The genetic stability and near universality of the 5S ribosomal gene allows for a useful means to study ancient evolutionary changes by macromolecular comparisons. The value in current and future ribosomal RNA comparisons is in fine tuning the assignment of ancestors to the organelles and in establishing extant species likely to be descendants of bacteria involved in presumed multiple endosymbiotic events.}, }
@article {pmid15275586, year = {1985}, author = {Roitman, I and Camargo, EP}, title = {Endosymbionts of trypanosomatidae.}, journal = {Parasitology today (Personal ed.)}, volume = {1}, number = {5}, pages = {143-144}, doi = {10.1016/0169-4758(85)90060-2}, pmid = {15275586}, issn = {0169-4758}, }
@article {pmid16593600, year = {1985}, author = {Marvel, DJ and Kuldau, G and Hirsch, A and Richards, E and Torrey, JG and Ausubel, FM}, title = {Conservation of nodulation genes between Rhizobium meliloti and a slow-growing Rhizobium strain that nodulates a nonlegume host.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {82}, number = {17}, pages = {5841-5845}, pmid = {16593600}, issn = {0027-8424}, abstract = {Parasponia, a woody member of the elm family, is the only nonlegume genus whose members are known to form an effective nitrogen-fixing symbiosis with a Rhizobium species. The bacterial strain RP501 is a slow-growing strain of Rhizobium isolated from Parasponia nodules. Strain RP501 also nodulates the legumes siratro (Macroptilium atropurpureum) and cowpea (Vigna unguiculata). Using a cosmid clone bank of RP501 DNA, we isolated a 13.4-kilobase (kb) EcoRI fragment that complemented insertion and point mutations in three contiguous nodulation genes (nodABC) of Rhizobium meliloti, the endosymbiont of alfalfa (Medicago sativa). The complemented R. meliloti nod mutants induced effective nitrogen-fixing nodules on alfalfa seedlings but not on siratro, cowpeas, or Parasponia. The cloned RP501 nodulation locus hybridized to DNA fragments carrying the R. meliloti nodABC genes. A 3-kb cluster of Tn5 insertion mutations on the RP501 13.4-kb EcoRI fragment prevented complementation of R. meliloti nodABC mutations.}, }
@article {pmid17843078, year = {1985}, author = {Wilcox, LW and Wedemayer, GJ}, title = {Dinoflagellate with blue-green chloroplasts derived from an endosymbiotic eukaryote.}, journal = {Science (New York, N.Y.)}, volume = {227}, number = {4683}, pages = {192-194}, doi = {10.1126/science.227.4683.192}, pmid = {17843078}, issn = {0036-8075}, abstract = {The dinoflagellate, Amphidinium wigrense, contains triple membrane-bound bodies we have termed "blue-green chloroplasts." We believe these chloroplasts were derived from a cryptomonad endosymbiont similar to that present in another blue-green dinoflagellate, Gymnodinium acidotum. These dinoflagellates provide evidence that a chloroplast has evolved from an endosymbiotic eukaryote.}, }
@article {pmid11541973, year = {1984}, author = {Hartman, H}, title = {The origin of the eukaryotic cell.}, journal = {Speculations in science and technology}, volume = {7}, number = {2}, pages = {77-81}, pmid = {11541973}, issn = {0155-7785}, mesh = {*Biological Evolution ; Cell Nucleus/*physiology ; Chromosomes/physiology ; DNA/physiology ; Eukaryotic Cells/*physiology ; RNA/*physiology ; Symbiosis ; }, abstract = {The endosymbiotic hypothesis for the origin of the eukaryotic cell has been applied to the origin of the mitochondria and chloroplasts. However as has been pointed out by Mereschowsky in 1905, it should also be applied to the nucleus as well. If the nucleus, mitochondria and chloroplasts are endosymbionts, then it is likely that the organism that did the engulfing was not a DNA-based organism. In fact, it is useful to postulate that this organism was a primitive RNA-based organism. This hypothesis would explain the preponderance of RNA viruses found in eukaryotic cells. The centriole and basal body do not have a double membrane or DNA. Like all MTOCs (microtubule organising centres), they have a structural or morphic RNA implicated in their formation. This would argue for their origin in the early RNA-based organism rather than in an endosymbiotic event involving bacteria. Finally, the eukaryotic cell uses RNA in ways quite unlike bacteria, thus pointing to a greater emphasis of RNA in both control and structure in the cell. The origin of the eukaryotic cell may tell us why it rather than its prokaryotic relative evolved into the metazoans who are reading this paper.}, }
@article {pmid17769213, year = {1983}, author = {Martínez, L and Silver, MW and King, JM and Alldredge, AL}, title = {Nitrogen fixation by floating diatom mats: a source of new nitrogen to oligotrophic ocean waters.}, journal = {Science (New York, N.Y.)}, volume = {221}, number = {4606}, pages = {152-154}, doi = {10.1126/science.221.4606.152}, pmid = {17769213}, issn = {0036-8075}, abstract = {Nitrogen fixation, apparently by bacterial endosymbionts, is associated with intertwining chains of two species of the diatom Rhizosolenia. In situ fixation rates were enhanced by incubation in the dark, whereas concurrent shipboard experiments either underestimated or did not detect nitrogen fixation. This is the first example of nitrogen fixation associated with a bacteria-diatom symbiosis in the pelagic zone, and it indicates that these systems may contribute a significant amount of "new" nitrogen to oligotrophic waters.}, }
@article {pmid16662839, year = {1983}, author = {Giddings, TH and Wasmann, C and Staehelin, LA}, title = {Structure of the Thylakoids and Envelope Membranes of the Cyanelles of Cyanophora paradoxa.}, journal = {Plant physiology}, volume = {71}, number = {2}, pages = {409-419}, pmid = {16662839}, issn = {0032-0889}, abstract = {The cyanelles of Cyanophora paradoxa Korsch. are photosynthetically active obligate endosymbionts in which phycobiliproteins serve as the major accessory pigments. Freeze-fracture electron micrographs of thylakoids in isolated cyanelles reveal long parallel rows of particles covering most of the E-face, while a more random particle arrangement is evident in some areas. The center-to-center spacing of particles within these rows is about 10 nanometers. Their mean diameter was measured at 9.4 nanometers. The particles on the P-face have a mean diameter of 7.2 nanometers. Thylakoids that retained nearly the full complement of phycobiliproteins (determined spectrophotometrically and by gel electrophoresis) were isolated from the cyanelles. In thin sections of these preparations, rows of disc-shaped phycobilisomes are evident on the surface of the thylakoids. The spacing of the rows of phycobilisomes corresponds to that of the rows of E-face particles (approximately 45 nanometers, center to center). The periodicity of the disc-shaped phycobilisomes within a row is 10 nanometers suggesting a one-to-one association between phycobilisomes and E-face particles.In addition, visualization of the protoplasmic surface (PS) of isolated thylakoids by freeze-etch electron microscopy shows that rows of disc-shaped phycobilisomes are aligned directly above rows of particles exhibiting two subunits, presumably the P-surface projections of the 10-nanometer intramembrane particles. These observations, together with earlier studies indicating that the 10-nanometer E-face particles probably represent photosystem II (PSII) complexes, suggest that phycobilisomes are positioned on the thylakoid surface in direct contact with PSII centers within the thylakoid membrane.The inner envelope membrane of the cyanelles, observed in freeze-fracture replicas, resembles cyanobacterial plasma membranes and is dissimilar to the chloroplast envelope membranes of red or green algae. The envelope of isolated cyanelles exhibits two additional layers: (a) a 5- to 7-nanometer-thick layer that lies adjacent to the inner membrane and which seems to correspond to the peptidoglycan layer of cyanobacteria; and (b) a layer external to the purported peptidoglycan layer that exhibits fracture faces similar to those of the lipopolysaccharide layer of gram negative bacteria. Our findings indicate that the supramolecular architecture of cyanelles differs only slightly from free-living cyanobacteria to which they are presumably related.}, }
@article {pmid17780880, year = {1981}, author = {Paau, AS and Leps, WT and Brill, WJ}, title = {Agglutinin from Alfalfa Necessary for Binding and Nodulation by Rhizobium meliloti.}, journal = {Science (New York, N.Y.)}, volume = {213}, number = {4515}, pages = {1513-1515}, doi = {10.1126/science.213.4515.1513}, pmid = {17780880}, issn = {0036-8075}, abstract = {A protein that specifically agglutinates Rhizobium meliloti, the alfalfa root nodule endosymbiont, has been purified from alfalfa seed. Material cross-reactive to antiserum prepared against the purified agglutinin is present in all alfalfa varieties that were tested but is absent in corn and other legumes not nodulated by Rhizobium meliloti. Studies with nonnodulating mutants of this microorganism incapable of binding to alfalfa roots suggest that the agglutinin is responsible for specific recognition between Rhizobium meliloti and alfalfa and that this recognition is an essential step in nodule formation.}, }
@article {pmid17847470, year = {1981}, author = {Doolittle, WF}, title = {The endosymbiont hypothesis.}, journal = {Science (New York, N.Y.)}, volume = {213}, number = {4508}, pages = {640-641}, doi = {10.1126/science.213.4508.640}, pmid = {17847470}, issn = {0036-8075}, }
@article {pmid17754039, year = {1978}, author = {Jeon, KW and Ahn, TI}, title = {Temperature sensitivity: a cell character determined by obligate endosymbionts in amoebas.}, journal = {Science (New York, N.Y.)}, volume = {202}, number = {4368}, pages = {635-637}, doi = {10.1126/science.202.4368.635}, pmid = {17754039}, issn = {0036-8075}, abstract = {A strain of Amoeba proteus has lost its ability to survive at temperatures above 26 degrees C as a result of becoming dependent on endosymbiotic bacteria that are psychrophile-like. The observed temperature sensitivity develops in fewer than 200 host cell generations (18 months of culture) after the host cells are experimentally infected with the symbionts.}, }
@article {pmid14492436, year = {1962}, author = {RIS, H and PLAUT, W}, title = {Ultrastructure of DNA-containing areas in the chloroplast of Chlamydomonas.}, journal = {The Journal of cell biology}, volume = {13}, number = {3}, pages = {383-391}, pmid = {14492436}, issn = {0021-9525}, mesh = {*Chlamydomonas ; *Chloroplasts ; DNA/*chemistry ; *Electrons ; Eukaryota/*chemistry ; *Microscopy ; *Microscopy, Electron ; }, abstract = {The chloroplast of Chlamydomonas moewusii was examined by electron microscopic and cytochemical methods for the possible presence of DNA. Both the Feulgen reaction and acridine orange indicated the presence within the chloroplast of one or more irregularly shaped DNA-containing bodies generally in the vicinity of the pyrenoid. Electron micrographs revealed 25 A microfibrils in these areas which correspond to DNA macromolecules with respect to their location, morphology, and sensitivity to deoxyribonuclease digestion. The possibility that this material is the genetic system of the chloroplast and the hypothesis that the chloroplast represents an evolved endosymbiont are discussed.}, }
@article {pmid10765727, year = {2000}, author = {Emel'ianov, VV}, title = {[Evolutionary relationship of Rickettsia and eukaryotic mitochondria].}, journal = {Vestnik Rossiiskoi akademii meditsinskikh nauk}, volume = {}, number = {3}, pages = {3-7}, pmid = {10765727}, issn = {0869-6047}, mesh = {Animals ; Archaea/genetics ; Eukaryota/genetics ; Heat-Shock Proteins/genetics ; Mitochondria/*genetics ; Paramecium/genetics ; *Phylogeny ; Rickettsia/*genetics ; Rickettsia prowazekii/genetics ; }, abstract = {To clarify the evolutionary relationship of rickettsiae and mitochondria, the conserved flat heat-shock protein Hsp60 was phylogenetically studied in detail by using PHYLIP and PROTML packages. The ample data set (50 species) included as many as possible representatives from the Rickettsiaceae family, mitochondrial-type homologs from Archezoa and mitochondrial homologs from Protozoa. Rickettsia prowazekii (that is the genus Rickettsia) was shown to be the least diverging member within Rickettsia--a sister group to the monophyletic clade of mitochondria. These findings were also evidenced by the phylogenetic analysis of 16S rRNA. Rickettsia-like endosymbionts (the parasites Paramecium caudatum and the etiological agent of hepatopancreatitis in shrimps) included within the order Rickettsiales appear to have diverged prior to the Rickettsiaceae/mitochondria cluster. Thus, the Rickettsiales does not seem to be a monophyletic group. An idea concerning the nature of obligate intracellular parasitism of rickettsiae is proposed in the paper from the suggested profound similarity of Rickettsiae genus bacteria and mitochondria which could have a common evolutionary history.}, }
@article {pmid10762429, year = {2000}, author = {Stanley, K and Fenton, B}, title = {A member of the Hsp60 gene family from the peach potato aphid, Myzus persicae (Sulzer.).}, journal = {Insect molecular biology}, volume = {9}, number = {2}, pages = {211-215}, doi = {10.1046/j.1365-2583.2000.00174.x}, pmid = {10762429}, issn = {0962-1075}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics ; Base Sequence ; Chaperonin 60/*genetics ; Gene Library ; *Genes, Insect ; Insect Vectors ; Luteovirus ; Mitochondria ; Molecular Sequence Data ; *Multigene Family ; Plant Diseases ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {A novel cDNA clone encoding a mitochondrial Hsp60 was isolated from a Myzus persicae cDNA library. The nucleotide sequence consisted of 2348 bp and contained an open reading frame (ORF) of 1722 bases. The putative protein encoded by this ORF consisted of 574 amino acids and was designated MPHSP60. Comparison of MPHSP60 with other Hsp60s found that it was most similar to Hsp60 from Culicoides variipennis (85.6% similarity). Phylogenetic analysis revealed that MPHSP60 is clustered together with other insect Hsp60s. Comparisons were also made between MPHSP60 and SymL, the GroEL homologue of Myzus persicae endosymbionts.}, }
@article {pmid10761696, year = {2000}, author = {Faria-e-Silva, PM and Attias, M and de Souza, W}, title = {Biochemical and ultrastructural changes in Herpetomonas roitmani related to the energy metabolism.}, journal = {Biology of the cell}, volume = {92}, number = {1}, pages = {39-47}, doi = {10.1016/S0248-4900(00)88762-6}, pmid = {10761696}, issn = {0248-4900}, support = {RR0450/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Culture Media/pharmacology ; Energy Metabolism/drug effects/*physiology ; Flagella/metabolism/ultrastructure ; Glucose/metabolism/pharmacology ; Image Processing, Computer-Assisted ; Microscopy, Electron ; Mitochondria/metabolism/ultrastructure ; Proline/metabolism/pharmacology ; *Trypanosomatina/growth &amp; development/metabolism/ultrastructure ; }, abstract = {Herpetomonas roitmani, a non-pathogenic trypanosomatid was grown in chemically defined media either containing proline or glucose as carbon source. Using transmission electron microscopy we observed that cells grown in the presence of proline present more lipid inclusions, and a larger mitochondrion with more cristae and higher activity of succinate cytochrome c reductase. On the other hand, cells grown with glucose as carbon source had more glycosomes, which were preferentially located close to the bacterium endosymbiont, and a much higher activity of hexokinase, a typical glycosome marker. Three-dimensional reconstruction and morphometrical analysis confirm these observations. The number of promastigotes of H. roitmani increased in the presence of proline. Taken together these results indicate that the growth conditions markedly influenced the ultrastructure and the metabolism of H. roitmani.}, }
@article {pmid10749774, year = {2000}, author = {Furla, P and Allemand, D and Orsenigo, MN}, title = {Involvement of H(+)-ATPase and carbonic anhydrase in inorganic carbon uptake for endosymbiont photosynthesis.}, journal = {American journal of physiology. Regulatory, integrative and comparative physiology}, volume = {278}, number = {4}, pages = {R870-81}, doi = {10.1152/ajpregu.2000.278.4.R870}, pmid = {10749774}, issn = {0363-6119}, mesh = {4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid/pharmacology ; Adenosine Triphosphatases/metabolism ; Animals ; Anion Transport Proteins ; Azides/pharmacology ; Bicarbonates/metabolism ; Biological Transport/drug effects/physiology ; Carbon/*pharmacokinetics ; Carbon Radioisotopes/pharmacokinetics ; Carbonic Anhydrases/*metabolism ; Cell Membrane/metabolism ; Chlorides/pharmacokinetics ; Chlorine/pharmacokinetics ; Ectoderm/metabolism ; Enzyme Inhibitors/pharmacology ; Eukaryota/enzymology ; Hydrogen-Ion Concentration ; Membrane Potentials/physiology ; Microvilli/metabolism ; Nitrobenzoates/pharmacology ; Oligomycins/pharmacology ; Osmolar Concentration ; Photosynthesis/*physiology ; Proton-Translocating ATPases/antagonists &amp; inhibitors/*metabolism ; Protons ; Radioisotopes/pharmacokinetics ; Rickettsiaceae/*enzymology ; Sea Anemones/*metabolism ; Vanadates/pharmacology ; ortho-Aminobenzoates/pharmacology ; }, abstract = {Symbiotic cnidarians absorb inorganic carbon from seawater to supply intracellular dinoflagellates with CO(2) for their photosynthesis. To determine the mechanism of inorganic carbon transport by animal cells, we used plasma membrane vesicles prepared from ectodermal cells isolated from tentacles of the sea anemone, Anemonia viridis. H(14)CO(-)(3) uptake in the presence of an outward NaCl gradient or inward H(+) gradient, showed no evidence for a Cl(-)- or H(+)- driven HCO(-)(3) transport. H(14)CO(-)(3) and (36)Cl(-) uptakes were stimulated by a positive inside-membrane diffusion potential, suggesting the presence of HCO(-)(3) and Cl(-) conductances. A carbonic anhydrase (CA) activity was measured on plasma membrane (4%) and in the cytoplasm of the ectodermal cells (96%) and was sensitive to acetazolamide (IC(50) = 20 nM) and ethoxyzolamide (IC(50) = 2.5 nM). A strong DIDS-sensitive H(+)-ATPase activity was observed (IC(50) = 14 microM). This activity was also highly sensitive to vanadate and allyl isothiocyanate, two inhibitors of P-type H(+)-ATPases. Present data suggest that HCO(-)(3) absorption by ectodermal cells is carried out by H(+) secretion by H(+)-ATPase, resulting in the formation of carbonic acid in the surrounding seawater, which is quickly dehydrated into CO(2) by a membrane-bound CA. CO(2) then diffuses passively into the cell where it is hydrated in HCO(-)(3) by a cytosolic CA.}, }
@article {pmid10742516, year = {2000}, author = {Clarebrough, C and Mira, A and Raubenheimer, D}, title = {Sex-specific differences in nitrogen intake and investment by feral and laboratory-cultured cockroaches.}, journal = {Journal of insect physiology}, volume = {46}, number = {5}, pages = {677-684}, doi = {10.1016/s0022-1910(99)00156-0}, pmid = {10742516}, issn = {1879-1611}, abstract = {We compared nutrient selection in a laboratory culture of the American cockroach (Periplaneta americana: Insecta, Blattodea) and a feral population which was founded by escapees from the culture approximately 14 generations prior to the study. In a first experiment, adult male and female cockroaches were provided with two nutritionally complementary synthetic foods, and thus allowed to select the protein and carbohydrate components of their diet independently. There were no differences in the amounts of carbohydrate eaten by the two populations. However, feral males ingested more protein than cultured males. In a second experiment, the construction of nitrogen budgets showed that the additional nitrogen ingested by feral males was allocated preferentially to accessory sex glands, rather than somatic tissue or excretion via the faeces. This suggests a possible role for sexual selection in the dietary difference between the strains. By contrast with males, there was no statistically significant difference in the amount of protein eaten by females of the two populations. However, feral females were found to have a higher density of bacterial endosymbionts than cultured females. Since these symbionts are involved in the synthesis of essential amino acids, this might account for greater reproductive output observed in a previous study in the feral compared with the culture females.}, }
@article {pmid10742267, year = {2000}, author = {Cifuentes, A and Antón, J and Benlloch, S and Donnelly, A and Herbert, RA and Rodríguez-Valera, F}, title = {Prokaryotic diversity in Zostera noltii-colonized marine sediments.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {4}, pages = {1715-1719}, pmid = {10742267}, issn = {0099-2240}, mesh = {Archaea/genetics/growth &amp; development/*isolation &amp; purification ; Bacteria/genetics/growth &amp; development/*isolation &amp; purification ; Cloning, Molecular ; DNA, Archaeal/analysis/isolation &amp; purification ; DNA, Bacterial/analysis/isolation &amp; purification ; DNA, Ribosomal/genetics ; Gene Library ; Geologic Sediments/*microbiology ; Molecular Sequence Data ; Phylogeny ; Poaceae/*growth &amp; development ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Seawater/*microbiology ; Water Microbiology ; }, abstract = {The diversity of microorganisms present in a sediment colonized by the phanerogam Zostera noltii has been analyzed. Microbial DNA was extracted and used for constructing two 16S rDNA clone libraries for Bacteria and Archaea. Bacterial diversity was very high in these samples, since 57 different sequences were found among the 60 clones analyzed. Eight major lineages of the Domain Bacteria were represented in the library. The most frequently retrieved bacterial group (36% of the clones) was delta-Proteobacteria related to sulfate-reducing bacteria. The second most abundant group (27%) was gamma-Proteobacteria, including five clones closely related to S-oxidizing endosymbionts. The archaeal clone library included members of Crenarchaeota and Euryarchaeota, with nine different sequences among the 15 analyzed clones, indicating less diversity when compared to the Bacteria organisms. None of these sequences was closely related to cultured Archaea organisms.}, }
@article {pmid10731575, year = {2000}, author = {Unnasch, TR and Williams, SA}, title = {The genomes of Onchocerca volvulus.}, journal = {International journal for parasitology}, volume = {30}, number = {4}, pages = {543-552}, doi = {10.1016/s0020-7519(99)00184-8}, pmid = {10731575}, issn = {0020-7519}, mesh = {Animals ; DNA, Mitochondrial/chemistry ; Gene Expression ; Genetic Variation ; *Genome ; Onchocerca volvulus/*genetics ; }, abstract = {Onchocerca volvulus, the filarial parasite that causes onchocerciasis or river blindness, contains three distinct genomes. These include the nuclear genome, the mitochondrial genome and the genome of an intracellular endosymbiont of the genus Wolbachia. The nuclear genome is roughly 1.5x10(8) bp in size, and is arranged on four chromosome pairs. Analysis of expressed sequence tags from different life-cycle stages has resulted in the identification of transcripts from roughly 4000 O. volvulus genes. Several of these transcripts are highly abundant, including those encoding collagen and cuticular proteins. Analysis of several gene sequences from O. volvulus suggests that the nuclear genes of O. volvulus are relatively compact and are interrupted relatively frequently by small introns. The intron-exon boundaries of these genes generally follow the GU-AG rule characteristic of the splice donor and acceptors of other vertebrate organisms. The nuclear genome also contains at least one repeated sequence family of a 150 bp repeat which is arranged in tandem arrays and appears subject to concerted evolution. The mitochondrial genome of O. volvulus is remarkably compact, only 13747 bp in size. Consistent with the small size of the genome, four gene pairs overlap, eight contain no intergenic regions and the remaining gene pairs are separated by small intergenic domains ranging from 1 to 46 bp. The protein-coding genes of the O. volvulus mitochondrial genome exhibit a striking codon bias, with 15/20 amino acids having a single codon preference greater than 70%. Intraspecific variation in both the nuclear and mitochondrial genomes appears to be quite limited, consistent with the hypothesis that O. volvulus has suffered a genetic bottleneck in the recent past.}, }
@article {pmid10731564, year = {2000}, author = {Williams, SA and Lizotte-Waniewski, MR and Foster, J and Guiliano, D and Daub, J and Scott, AL and Slatko, B and Blaxter, ML}, title = {The filarial genome project: analysis of the nuclear, mitochondrial and endosymbiont genomes of Brugia malayi.}, journal = {International journal for parasitology}, volume = {30}, number = {4}, pages = {411-419}, doi = {10.1016/s0020-7519(00)00014-x}, pmid = {10731564}, issn = {0020-7519}, mesh = {Animals ; Brugia malayi/*genetics ; Chromosome Mapping ; DNA, Mitochondrial/chemistry ; Expressed Sequence Tags ; Filariasis/genetics ; *Genome ; Humans ; Wolbachia/genetics ; }, abstract = {The Filarial Genome Project (FGP) was initiated in 1994 under the auspices of the World Health Organisation. Brugia malayi was chosen as the model organism due to the availability of all life cycle stages for the construction of cDNA libraries. To date, over 20000 cDNA clones have been partially sequenced and submitted to the EST database (dbEST). These ESTs define approximately 7000 new Brugia genes. Analysis of the EST dataset provides useful information on the expression pattern of the most abundantly expressed Brugia genes. Some highly expressed genes have been identified that are expressed in all stages of the parasite's life cycle, while other highly expressed genes appear to be stage-specific. To elucidate the structure of the Brugia genome and to provide a basis for comparison to the Caenorhabditis elegans genome, the FGP is also constructing a physical map of the Brugia chromosomes and is sequencing genomic BAC clones. In addition to the nuclear genome, B. malayi possesses two other genomes: the mitochondrial genome and the genome of a bacterial endosymbiont. Eighty percent of the mitochondrial genome of B. malayi has been sequenced and is being compared to mitochondrial sequences of other nematodes. The bacterial endosymbiont genome found in B. malayi is closely related to the Wolbachia group of rickettsia-like bacteria that infects many insect species. A set of overlapping BAC clones is being assembled to cover the entire bacterial genome. Currently, half of the bacterial genome has been assembled into four contigs. A consortium has been established to sequence the entire genome of the Brugia endosymbiont. The sequence and mapping data provided by the FGP is being utilised by the nematode research community to develop a better understanding of the biology of filarial parasites and to identify new vaccine candidates and drug targets to aid the elimination of human filariasis.}, }
@article {pmid10713172, year = {2000}, author = {Dyall, SD and Koehler, CM and Delgadillo-Correa, MG and Bradley, PJ and Plümper, E and Leuenberger, D and Turck, CW and Johnson, PJ}, title = {Presence of a member of the mitochondrial carrier family in hydrogenosomes: conservation of membrane-targeting pathways between hydrogenosomes and mitochondria.}, journal = {Molecular and cellular biology}, volume = {20}, number = {7}, pages = {2488-2497}, pmid = {10713172}, issn = {0270-7306}, support = {T32 AI007323/AI/NIAID NIH HHS/United States ; R01 AI027857/AI/NIAID NIH HHS/United States ; AI07323/AI/NIAID NIH HHS/United States ; AI27857/AI/NIAID NIH HHS/United States ; /WT_/Wellcome Trust/United Kingdom ; R37 AI027857/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Carrier Proteins/chemistry/*genetics/metabolism ; Cloning, Molecular ; Energy Metabolism ; Evolution, Molecular ; Fungal Proteins/chemistry ; Membrane Proteins/chemistry/genetics/metabolism ; Mitochondria/*metabolism ; Mitochondrial ADP, ATP Translocases/chemistry/genetics/metabolism ; Molecular Sequence Data ; Phylogeny ; Protein Sorting Signals/chemistry/metabolism ; Protozoan Proteins/chemistry/*genetics/metabolism ; *Saccharomyces cerevisiae Proteins ; Sequence Alignment ; Trichomonas vaginalis/*chemistry/cytology ; }, abstract = {A number of microaerophilic eukaryotes lack mitochondria but possess another organelle involved in energy metabolism, the hydrogenosome. Limited phylogenetic analyses of nuclear genes support a common origin for these two organelles. We have identified a protein of the mitochondrial carrier family in the hydrogenosome of Trichomonas vaginalis and have shown that this protein, Hmp31, is phylogenetically related to the mitochondrial ADP-ATP carrier (AAC). We demonstrate that the hydrogenosomal AAC can be targeted to the inner membrane of mitochondria isolated from Saccharomyces cerevisiae through the Tim9-Tim10 import pathway used for the assembly of mitochondrial carrier proteins. Conversely, yeast mitochondrial AAC can be targeted into the membranes of hydrogenosomes. The hydrogenosomal AAC contains a cleavable, N-terminal presequence; however, this sequence is not necessary for targeting the protein to the organelle. These data indicate that the membrane-targeting signal(s) for hydrogenosomal AAC is internal, similar to that found for mitochondrial carrier proteins. Our findings indicate that the membrane carriers and membrane protein-targeting machinery of hydrogenosomes and mitochondria have a common evolutionary origin. Together, they provide strong evidence that a single endosymbiont evolved into a progenitor organelle in early eukaryotic cells that ultimately give rise to these two distinct organelles and support the hydrogen hypothesis for the origin of the eukaryotic cell.}, }
@article {pmid10677847, year = {2000}, author = {van Hoek, AH and van Alen, TA and Sprakel, VS and Leunissen, JA and Brigge, T and Vogels, GD and Hackstein, JH}, title = {Multiple acquisition of methanogenic archaeal symbionts by anaerobic ciliates.}, journal = {Molecular biology and evolution}, volume = {17}, number = {2}, pages = {251-258}, doi = {10.1093/oxfordjournals.molbev.a026304}, pmid = {10677847}, issn = {0737-4038}, mesh = {Anaerobiosis ; Animals ; Ciliophora/genetics/*physiology ; Cockroaches ; DNA, Archaeal/genetics ; DNA, Ribosomal/genetics ; Euryarchaeota/genetics/*physiology ; *Phylogeny ; RNA, Archaeal/genetics ; RNA, Ribosomal, 16S/*genetics ; Rana ridibunda ; *Symbiosis ; }, abstract = {Anaerobic heterotrichous ciliates (Armophoridae and Clevelandellidae) possess hydrogenosomes that generate molecular hydrogen and ATP. This intracellular source of hydrogen provides the basis for a stable endosymbiotic association with methanogenic archaea. We analyzed the SSU rRNA genes of 18 heterotrichous anaerobic ciliates and their methanogenic endosymbionts in order to unravel the evolution of this mutualistic association. Here, we show that the anaerobic heterotrichous ciliates constitute at least three evolutionary lines. One group consists predominantly of gut-dwelling ciliates, and two to three, potentially four, additional clades comprise ciliates that thrive in freshwater sediments. Their methanogenic endosymbionts belong to only two different taxa that are closely related to free-living methanogenic archaea from the particular ecological niches. The close phylogenetic relationships between the endosymbionts and free-living methanogenic archaea argue for multiple acquisitions from environmental sources, notwithstanding the strictly vertical transmission of the endosymbionts. Since phylogenetic analysis of the small-subunit (SSU) rRNA genes of the hydrogenosomes of these ciliates indicates a descent from the mitochondria of aerobic ciliates, it is likely that anaerobic heterotrichous ciliates hosted endosymbiotic methanogens prior to their radiation. Therefore, our data strongly suggest multiple acquisitions and replacements of endosymbiotic methanogenic archaea during their host's adaptation to the various ecological niches.}, }
@article {pmid10699667, year = {2000}, author = {Brüggemann, J and Stephen, JR and Chang, YJ and Macnaughton, SJ and Kowalchuk, GA and Kline, E and White, DC}, title = {Competitive PCR-DGGE analysis of bacterial mixtures: an internal standard and an appraisal of template enumeration accuracy.}, journal = {Journal of microbiological methods}, volume = {40}, number = {2}, pages = {111-123}, doi = {10.1016/s0167-7012(99)00126-8}, pmid = {10699667}, issn = {0167-7012}, mesh = {Alcaligenes/genetics ; DNA Primers ; DNA, Bacterial/analysis ; DNA, Ribosomal/analysis ; Desulfovibrio vulgaris/genetics ; Electrophoresis, Polyacrylamide Gel/methods ; Molecular Sequence Data ; Polymerase Chain Reaction/methods ; Proteobacteria/*genetics ; RNA, Ribosomal, 16S/analysis ; Sensitivity and Specificity ; Shewanella putrefaciens/genetics ; }, abstract = {Analysis of polymerase chain reaction (PCR) amplified 16S rDNA fragments from environmental samples by denaturing gradients of chemicals or heat [denaturing gradient gel electrophoresis (DGGE) and thermal gradient gel electrophoresis (TGGE)] within polyacrylamide gels is a popular tool in microbial ecology. Difficulties in acceptance of the technique and interpretation of the results remain, due to its qualitative nature. In this study we have addressed this problem by the construction and evaluation of a quantitative standard for incorporation into test DNA samples. The standard was based on a naturally occurring 16S rRNA gene carried by the X-endosymbiont of the psyllid Anomoneura mori, a gamma-proteobacterium. This sequence is the most AT-rich 16S rDNA gene recovered from any cultured organism or environmental sample described to date, and a specifically amplified rDNA fragment denatured under exceptionally low stringency denaturing conditions. The native sequence was modified to incorporate perfect matches to the PCR primers used. The efficiency of amplification of this standard in comparison to a range of 16S rDNA sequences and the errors involved in enumerating template molecules under a range of PCR conditions are demonstrated and quantified. Tests indicated that highly accurate counts of released target molecules from a range of bacterial cells could be achieved in both laboratory mixtures and compost.}, }
@article {pmid10696593, year = {2000}, author = {Hongoh, Y and Sasaki, T and Ishikawa, H}, title = {Cloning, sequence analysis and expression in Escherichia coli of the gene encoding a uricase from the yeast-like symbiont of the brown planthopper, Nilaparvata lugens.}, journal = {Insect biochemistry and molecular biology}, volume = {30}, number = {2}, pages = {173-182}, doi = {10.1016/s0965-1748(99)00116-2}, pmid = {10696593}, issn = {0965-1748}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA Primers/genetics ; DNA, Complementary/genetics ; DNA, Fungal/genetics ; Escherichia coli/*genetics ; Fungi/*enzymology/*genetics/isolation &amp; purification ; Gene Expression ; *Genes, Fungal ; Hemiptera/*microbiology ; Isoelectric Point ; Molecular Sequence Data ; Molecular Weight ; Sequence Homology, Amino Acid ; *Symbiosis ; Urate Oxidase/chemistry/*genetics/metabolism ; }, abstract = {A urate oxidase (uricase; EC 1.7.3.3) gene of the yeast-like fungal endosymbiont of the brown planthopper, Nilaparvata lugens, was cloned, and sequenced together with its flanking regions. The gene comprised a open reading frame of 987 bp, that was split into two parts by a single 96 bp intron. The encoded uricase was 296 amino acids with 62% sequence identity with that of Aspergillus flavus. The molecular weight deduced was 32,882, and the predicted isoelectric point was 6.06. The symbiont's uricase conserved all the known consensus motifs, except the C-terminal PTS-1, Ser-basic-Leu. The leucine at the third position of PTS-1 was replaced by serine in the C-terminus of the symbiont's uricase. The symbiont's uricase gene was successfully expressed in Escherichia coli, and the product, tagged with histidine residues, was purified. The symbiont's uricase, thus produced, was as active as those from plants and animals, but less active than those from other fungi.}, }
@article {pmid10690412, year = {1999}, author = {Lang, BF and Gray, MW and Burger, G}, title = {Mitochondrial genome evolution and the origin of eukaryotes.}, journal = {Annual review of genetics}, volume = {33}, number = {}, pages = {351-397}, doi = {10.1146/annurev.genet.33.1.351}, pmid = {10690412}, issn = {0066-4197}, mesh = {Animals ; DNA, Mitochondrial/*genetics ; Eukaryotic Cells ; *Evolution, Molecular ; Fungi/genetics ; Mitochondria/*genetics ; Phylogeny ; }, abstract = {Recent results from ancestral (minimally derived) protists testify to the tremendous diversity of the mitochondrial genome in various eukaryotic lineages, but also reinforce the view that mitochondria, descendants of an endosymbiotic alpha-Proteobacterium, arose only once in evolution. The serial endosymbiosis theory, currently the most popular hypothesis to explain the origin of mitochondria, postulates the capture of an alpha-proteobacterial endosymbiont by a nucleus-containing eukaryotic host resembling extant amitochondriate protists. New sequence data have challenged this scenario, instead raising the possibility that the origin of the mitochondrion was coincident with, and contributed substantially to, the origin of the nuclear genome of the eukaryotic cell. Defining more precisely the alpha-proteobacterial ancestry of the mitochondrial genome, and the contribution of the endosymbiotic event to the nuclear genome, will be essential for a full understanding of the origin and evolution of the eukaryotic cell as a whole.}, }
@article {pmid10678988, year = {2000}, author = {Inglis, TJ and Rigby, P and Robertson, TA and Dutton, NS and Henderson, M and Chang, BJ}, title = {Interaction between Burkholderia pseudomallei and Acanthamoeba species results in coiling phagocytosis, endamebic bacterial survival, and escape.}, journal = {Infection and immunity}, volume = {68}, number = {3}, pages = {1681-1686}, pmid = {10678988}, issn = {0019-9567}, mesh = {Acanthamoeba/*physiology ; Animals ; Burkholderia pseudomallei/*physiology ; Coculture Techniques ; Humans ; Microscopy, Confocal ; Microscopy, Electron ; *Phagocytosis ; }, abstract = {Burkholderia pseudomallei causes melioidosis, a potentially fatal disease whose clinical outcomes include rapid-onset septicemia and relapsing and delayed-onset infections. Like other facultative intracellular bacterial pathogens, B. pseudomallei is capable of survival in human phagocytic cells, but unlike mycobacteria, Listeria monocytogenes, and Salmonella serovar Typhimurium, the species has not been reported to survive as an endosymbiont in free-living amebae. We investigated the consequences of exposing Acanthamoeba astronyxis, A. castellani, and A. polyphaga to B. pseudomallei NCTC 10276 in a series of coculture experiments. Bacterial endocytosis was observed in all three Acanthamoeba species. A more extensive range of cellular interactions including bacterial adhesion, incorporation into amebic vacuoles, and separation was observed with A. astronyxis in timed coculture experiments. Amebic trophozoites containing motile intravacuolar bacilli were found throughout 72 h of coculture. Confocal microscopy was used to confirm the intracellular location of endamebic B. pseudomallei cells. Transmission electron microscopy of coculture preparations revealed clusters of intact bacilli in membrane-lined vesicles inside the trophozoite cytoplasm; 5 x 10(2) CFU of bacteria per ml were recovered from lysed amebic trophozoites after 60 min of coculture. Demonstration of an interaction between B. pseudomallei and free-living acanthamebae in vitro raises the possibility that a similar interaction in vivo might affect environmental survival of B. pseudomallei and subsequent human exposure. Endamebic passage of B. pseudomallei warrants further investigation as a potential in vitro model of intracellular B. pseudomallei infection.}, }
@article {pmid10688696, year = {2000}, author = {Soler, T and Latorre, A and Sabater, B and Silva, FJ}, title = {Molecular characterization of the leucine plasmid from Buchnera aphidicola, primary endosymbiont of the aphid Acyrthosiphon pisum.}, journal = {Current microbiology}, volume = {40}, number = {4}, pages = {264-268}, doi = {10.1007/s002849910052}, pmid = {10688696}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; Buchnera/*genetics ; *Genes, Bacterial ; Leucine/*genetics ; Microsatellite Repeats ; Minisatellite Repeats ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; Plasmids/*genetics ; Symbiosis/genetics ; }, abstract = {The complete sequence of the leucine plasmid of Buchnera aphidicola from the aphid Acyrthosiphon pisum (pLeu-BAp) is reported. Its gene organization was concordant with those of other leucine plasmids of Buchnera from aphids of the Aphidini and Macrosiphini tribes. Three inverted repeats are present in pLeu-BAp. Two of them are also present in pLeu from the family Aphididae: (i) SIR1, located downstream the leucine operon, resembles a rho-independent terminator of transcription, and (ii) LIR1, located upstream of the leucine operon, is suggested to be involved in transcription termination or messenger stability. The third, located near the putative ATGC repeats involved in the origin of replication, is specific in aphids of the Macrosiphini tribe. Phylogenetic analyses based on sequences of leuA, leuB, leuC, leuD, repA1 and ORF1 showed a closer relationship between Buchnera (A. pisum) and Buchnera (Diuraphis noxia). However, tree topologies indicate that the split between both aphid species took place soon after the formation of the Macrosiphini lineage.}, }
@article {pmid10668862, year = {1999}, author = {van Opijnen, T and Breeuwer, JA}, title = {High temperatures eliminate Wolbachia, a cytoplasmic incompatibility inducing endosymbiont, from the two-spotted spider mite.}, journal = {Experimental &amp; applied acarology}, volume = {23}, number = {11}, pages = {871-881}, pmid = {10668862}, issn = {0168-8162}, mesh = {Administration, Oral ; Animals ; Anti-Bacterial Agents/administration &amp; dosage/pharmacology ; Crosses, Genetic ; DNA, Bacterial/genetics/isolation &amp; purification ; Female ; Hot Temperature ; Male ; Mites/*microbiology/physiology ; Polymerase Chain Reaction ; Sex Ratio ; *Symbiosis ; Wolbachia/drug effects/genetics/*physiology ; }, abstract = {Wolbachia can induce cytoplasmic incompatibility (CI) in the arrhenotokous two-spotted spider mite between uninfected females and infected males. Cytoplasmic incompatibility is expressed through a male-biased sex ratio and a low hatchability, and can be suppressed by removing Wolbachia from spider mites reared on a diet with antibiotics. Here we investigated whether heat-treatment can elimate Wolbachia from infected mites. Using a PCR assay with a Wolbachia-specific primer pair (ftsZ), and by standard crosses, we were able to show that 71 per cent of the mites had lost the Wolbachia infection after rearing the infected population at 32+/-0.5 degrees C for four generations. The infection could be completely removed when mites were reared at 32+/-0.5 degrees C for six generations. Curing through high temperatures could be one of the reasons why mixed infected/uninfected populations occur in the field. An additional consequence of rearing mites at 32+/-0.5 degrees C was the shortened development time. The effect of environmental temperature on the abundance of Wolbachia and possible behavioural consequences for the spider mite are discussed.}, }
@article {pmid10653731, year = {2000}, author = {Di Meo, CA and Wilbur, AE and Holben, WE and Feldman, RA and Vrijenhoek, RC and Cary, SC}, title = {Genetic variation among endosymbionts of widely distributed vestimentiferan tubeworms.}, journal = {Applied and environmental microbiology}, volume = {66}, number = {2}, pages = {651-658}, pmid = {10653731}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*genetics ; Base Sequence ; DNA Fingerprinting ; DNA, Ribosomal/analysis ; Genes, rRNA ; *Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Polychaeta/*microbiology ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Repetitive Sequences, Nucleic Acid ; Seawater ; Sequence Alignment ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {Vestimentiferan tubeworms thriving in sulfidic deep-sea hydrothermal vents and cold seeps are constrained by their nutritional reliance on chemoautotrophic endosymbionts. In a recent phylogenetic study using 16S ribosomal DNA, we found that endosymbionts from vent and seep habitats form two distinct clades with little variation within each clade. In the present study, we used two different approaches to assess the genetic variation among biogeographically distinct vestimentiferan symbionts. DNA sequences were obtained for the noncoding, internal transcribed spacer (ITS) regions of the rRNA operons of symbionts associated with six different genera of vestimentiferan tubeworms. ITS sequences from endosymbionts of host genera collected from different habitats and widely distributed vent sites were surprisingly conserved. Because the ITS region was not sufficient for distinguishing endosymbionts from different habitats or locations, we used a DNA fingerprinting technique, repetitive-extragenic-palindrome PCR (REP-PCR), to reveal differences in the distribution of repetitive sequences in the genomes of the bacterial endosymbionts. Most of the endosymbionts displayed unique REP-PCR patterns. A cladogram generated from these fingerprints reflected relationships that may be influenced by a variety of factors, including host genera, geographic location, and bottom type.}, }
@article {pmid10653730, year = {2000}, author = {Fukatsu, T and Nikoh, N}, title = {Endosymbiotic microbiota of the bamboo pseudococcid Antonina crawii (Insecta, Homoptera).}, journal = {Applied and environmental microbiology}, volume = {66}, number = {2}, pages = {643-650}, pmid = {10653730}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/genetics/*isolation &amp; purification ; Betaproteobacteria/classification/genetics/isolation &amp; purification ; Cloning, Molecular ; DNA, Ribosomal/analysis/genetics ; Gammaproteobacteria/classification/genetics/isolation &amp; purification ; Genes, rRNA ; In Situ Hybridization ; Insecta/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Spiroplasma/classification/genetics/isolation &amp; purification ; *Symbiosis ; }, abstract = {We characterized the intracellular symbiotic microbiota of the bamboo pseudococcid Antonina crawii by performing a molecular phylogenetic analysis in combination with in situ hybridization. Almost the entire length of the bacterial 16S rRNA gene was amplified and cloned from A. crawii whole DNA. Restriction fragment length polymorphism analysis revealed that the clones obtained included three distinct types of sequences. Nucleotide sequences of the three types were determined and subjected to a molecular phylogenetic analysis. The first sequence was a member of the gamma subdivision of the division Proteobacteria (gamma-Proteobacteria) to which no sequences in the database were closely related, although the sequences of endosymbionts of other homopterans, such as psyllids and aphids, were distantly related. The second sequence was a beta-Proteobacteria sequence and formed a monophyletic group with the sequences of endosymbionts from other pseudococcids. The third sequence exhibited a high level of similarity to sequences of Spiroplasma spp. from ladybird beetles and a tick. Localization of the endosymbionts was determined by using tissue sections of A. crawii and in situ hybridization with specific oligonucleotide probes. The gamma- and beta-Proteobacteria symbionts were packed in the cytoplasm of the same mycetocytes (or bacteriocytes) and formed a large mycetome (or bacteriome) in the abdomen. The spiroplasma symbionts were also present intracellularly in various tissues at a low density. We observed that the anterior poles of developing eggs in the ovaries were infected by the gamma- and beta-Proteobacteria symbionts in a systematic way, which ensured vertical transmission. Five representative pseudococcids were examined by performing diagnostic PCR experiments with specific primers; the beta-Proteobacteria symbiont was detected in all five pseudococcids, the gamma-Proteobacteria symbiont was found in three, and the spiroplasma symbiont was detected only in A. crawii.}, }
@article {pmid10620236, year = {1999}, author = {Fukatsu, T}, title = {Acetone preservation: a practical technique for molecular analysis.}, journal = {Molecular ecology}, volume = {8}, number = {11}, pages = {1935-1945}, doi = {10.1046/j.1365-294x.1999.00795.x}, pmid = {10620236}, issn = {0962-1083}, mesh = {*Acetone ; Animals ; Aphids/*genetics/*microbiology ; Buchnera/*physiology ; DNA/chemistry/isolation &amp; purification ; Electrophoresis, Polyacrylamide Gel ; Ethanol ; Immunohistochemistry ; In Situ Hybridization ; Proteins/chemistry/isolation &amp; purification ; RNA/chemistry/isolation &amp; purification ; Specimen Handling ; Symbiosis ; *Tissue Preservation ; }, abstract = {In attempts to establish a convenient and reliable method for field collection and archival preservation of insects and their endosymbiotic microorganisms for molecular analysis, acetone, ethanol, and other organic solvents were tested for DNA preservability of the pea aphid Acyrthosiphon pisum and its intracellular symbiotic bacterium Buchnera sp. After 6 months' storage, not only the band of high-molecular-size DNA but also the bands of rRNA were well preserved in acetone, ethanol, 2-propanol, diethyl ether and ethyl acetate. Polymerase chain reaction (PCR) assays confirmed that the DNA of both the insects and their symbionts was well preserved in these solvents. In contrast, methanol and chloroform showed poor DNA preservability. When water-containing series of acetone and ethanol were examined for DNA preservability, acetone was apparently more robust against water contamination than ethanol. Considering that most biological materials contain high amounts of water, acetone may be a more recommendable preservative for DNA analysis than ethanol which has been widely used for this purpose. The DNA of various insects could be preserved in acetone at room temperature in good condition for several years. In addition to the DNA of the host insects, the DNA of their endosymbionts, including Buchnera and other mycetocyte symbionts, Wolbachia, and gut bacteria, was amplified by PCR after several years of acetone storage. The RNA and protein of the pea aphid and its endosymbiont were also preserved for several years in acetone. After 2 years' storage in acetone, proteins of A. pisum could be analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting, and the endosymbiotic bacteria were successfully detected by immunohistochemistry and in situ hybridization on the tissue sections.}, }
@article {pmid10618395, year = {2000}, author = {Zauner, S and Fraunholz, M and Wastl, J and Penny, S and Beaton, M and Cavalier-Smith, T and Maier, UG and Douglas, S}, title = {Chloroplast protein and centrosomal genes, a tRNA intron, and odd telomeres in an unusually compact eukaryotic genome, the cryptomonad nucleomorph.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {97}, number = {1}, pages = {200-205}, pmid = {10618395}, issn = {0027-8424}, mesh = {Algal Proteins/genetics ; Base Sequence ; Biological Evolution ; *Centrosome ; Chimera/*genetics ; Cloning, Molecular ; Eukaryota/*genetics ; Genes, Plant/genetics ; Genome ; Introns/*genetics ; Molecular Sequence Data ; Nucleic Acid Conformation ; Physical Chromosome Mapping ; RNA, Transfer/*genetics ; Repetitive Sequences, Nucleic Acid ; Telomere/*genetics ; }, abstract = {Cells of several major algal groups are evolutionary chimeras of two radically different eukaryotic cells. Most of these "cells within cells" lost the nucleus of the former algal endosymbiont. But after hundreds of millions of years cryptomonads still retain the nucleus of their former red algal endosymbiont as a tiny relict organelle, the nucleomorph, which has three minute linear chromosomes, but their function and the nature of their ends have been unclear. We report extensive cryptomonad nucleomorph sequences (68.5 kb), from one end of each of the three chromosomes of Guillardia theta. Telomeres of the nucleomorph chromosomes differ dramatically from those of other eukaryotes, being repeats of the 23-mer sequence (AG)(7)AAG(6)A, not a typical hexamer (commonly TTAGGG). The subterminal regions comprising the rRNA cistrons and one protein-coding gene are exactly repeated at all three chromosome ends. Gene density (one per 0.8 kb) is the highest for any cellular genome. None of the 38 protein-coding genes has spliceosomal introns, in marked contrast to the chlorarachniophyte nucleomorph. Most identified nucleomorph genes are for gene expression or protein degradation; histone, tubulin, and putatively centrosomal ranbpm genes are probably important for chromosome segregation. No genes for primary or secondary metabolism have been found. Two of the three tRNA genes have introns, one in a hitherto undescribed location. Intergenic regions are exceptionally short; three genes transcribed by two different RNA polymerases overlap their neighbors. The reported sequences encode two essential chloroplast proteins, FtsZ and rubredoxin, thus explaining why cryptomonad nucleomorphs persist.}, }
@article {pmid10612677, year = {1999}, author = {Osinga, R and Tramper, J and Wijffels, RH}, title = {Cultivation of Marine Sponges.}, journal = {Marine biotechnology (New York, N.Y.)}, volume = {1}, number = {6}, pages = {509-532}, doi = {10.1007/pl00011807}, pmid = {10612677}, issn = {1436-2236}, abstract = {There is increasing interest in biotechnological production of marine sponge biomass owing to the discovery of many commercially important secondary metabolites in this group of animals. In this article, different approaches to producing sponge biomass are reviewed, and several factors that possibly influence culture success are evaluated. In situ sponge aquacultures, based on old methods for producing commercial bath sponges, are still the easiest and least expensive way to obtain sponge biomass in bulk. However, success of cultivation with this method strongly depends on the unpredictable and often suboptimal natural environment. Hence, a better-defined production system would be desirable. Some progress has been made with culturing sponges in semicontrolled systems, but these still use unfiltered natural seawater. Cultivation of sponges under completely controlled conditions has remained a problem. When designing an in vitro cultivation method, it is important to determine both qualitatively and quantitatively the nutritional demands of the species that is to be cultured. An adequate supply of food seems to be the key to successful sponge culture. Recently, some progress has been made with sponge cell cultures. The advantage of cell cultures is that they are completely controlled and can easily be manipulated for optimal production of the target metabolites. However, this technique is still in its infancy: a continuous cell line has yet to be established. Axenic cultures of sponge aggregates (primmorphs) may provide an alternative to cell culture. Some sponge metabolites are, in fact, produced by endosymbiotic bacteria or algae that live in the sponge tissue. Only a few of these endosymbionts have been cultivated so far. The biotechnology for the production of sponge metabolites needs further development. Research efforts should be continued to enable commercial exploitation of this valuable natural resource in the near future.}, }
@article {pmid10607659, year = {1999}, author = {McFadden, GI}, title = {Endosymbiosis and evolution of the plant cell.}, journal = {Current opinion in plant biology}, volume = {2}, number = {6}, pages = {513-519}, doi = {10.1016/s1369-5266(99)00025-4}, pmid = {10607659}, issn = {1369-5266}, mesh = {Chloroplasts/genetics ; Cyanobacteria/genetics ; *Evolution, Molecular ; Plant Cells ; Plants/*genetics ; Symbiosis/*genetics ; }, abstract = {The bacterial origins of plastid division and protein import by plastids are beginning to emerge - thanks largely to the availability of a total genome sequence for a cyanobacterium. Despite existing for hundreds of millions of years within the plant cell host, the chloroplast endosymbiont retains clear hallmarks of its bacterial ancestry. Plastid division relies on proteins that are also responsible for bacterial division, although may of the genes for these proteins have been confiscated by the host. Plastid protein import on the other hand relies on proteins that seem to have functioned originally as exporters but that have now been persuaded to operate in the reverse direction to traffic proteins from the host cell into the endosymbiont.}, }
@article {pmid10607615, year = {1999}, author = {Gray, MW}, title = {Evolution of organellar genomes.}, journal = {Current opinion in genetics &amp; development}, volume = {9}, number = {6}, pages = {678-687}, doi = {10.1016/s0959-437x(99)00030-1}, pmid = {10607615}, issn = {0959-437X}, mesh = {Animals ; Chloroplasts/genetics ; DNA, Chloroplast/*genetics ; DNA, Mitochondrial/*genetics ; *Evolution, Molecular ; Genes, Bacterial/genetics ; Genes, Plant/genetics ; *Genome ; Mitochondria/genetics ; Models, Genetic ; Organelles/*genetics ; Phylogeny ; }, abstract = {Accumulating molecular data, particularly complete organellar genome sequences, continue to advance our understanding of the evolution of mitochondrial and chloroplast DNAs. Although the notion of a single primary origin for each organelle has been reinforced, new models have been proposed that tie the acquisition of mitochondria more closely to the origin of the eukaryotic cell per se than is implied by classic endosymbiont theory. The form and content of the ancestral proto-mitochondrial and proto-chloroplast genomes are becoming clearer but unusual patterns of organellar genome structure and organization continue to be discovered. The 'single-gene circle' arrangement recently reported for dinoflagellate chloroplast genomes is a notable example of a highly derived organellar genome.}, }
@article {pmid10605125, year = {1999}, author = {Charles, H and Mouchiroud, D and Lobry, J and Gonçalves, I and Rahbe, Y}, title = {Gene size reduction in the bacterial aphid endosymbiont, Buchnera.}, journal = {Molecular biology and evolution}, volume = {16}, number = {12}, pages = {1820-1822}, doi = {10.1093/oxfordjournals.molbev.a026096}, pmid = {10605125}, issn = {0737-4038}, mesh = {Animals ; Aphids/*microbiology ; Buchnera/*genetics ; Escherichia coli/genetics ; *Genome, Bacterial ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Deletion ; }, }
@article {pmid10588716, year = {1999}, author = {Waters, ER and Vierling, E}, title = {Chloroplast small heat shock proteins: evidence for atypical evolution of an organelle-localized protein.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {96}, number = {25}, pages = {14394-14399}, pmid = {10588716}, issn = {0027-8424}, support = {R01 GM2762/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; *Biological Evolution ; Chloroplasts/*chemistry ; Conserved Sequence ; Cyanobacteria/chemistry ; Heat-Shock Proteins/*chemistry/isolation &amp; purification/physiology ; Molecular Sequence Data ; Phylogeny ; Protein Structure, Secondary ; }, abstract = {Knowledge of the origin and evolution of gene families is critical to our understanding of the evolution of protein function. To gain a detailed understanding of the evolution of the small heat shock proteins (sHSPs) in plants, we have examined the evolutionary history of the chloroplast (CP)-localized sHSPs. Previously, these nuclear-encoded CP proteins had been identified only from angiosperms. This study reveals the presence of the CP sHSPs in a moss, Funaria hygrometrica. Two clones for CP sHSPs were isolated from a F. hygrometrica heat shock cDNA library that represent two distinct CP sHSP genes. Our analysis of the CP sHSPs reveals unexpected evolutionary relationships and patterns of sequence conservation. Phylogenetic analysis of the CP sHSPs with other plant CP sHSPs and eukaryotic, archaeal, and bacterial sHSPs shows that the CP sHSPs are not closely related to the cyanobacterial sHSPs. Thus, they most likely evolved via gene duplication from a nuclear-encoded cytosolic sHSP and not via gene transfer from the CP endosymbiont. Previous sequence analysis had shown that all angiosperm CP sHSPs possess a methionine-rich region in the N-terminal domain. The primary sequence of this region is not highly conserved in the F. hygrometrica CP sHSPs. This lack of sequence conservation indicates that sometime in land plant evolution, after the divergence of mosses from the common ancestor of angiosperms but before the monocot-dicot divergence, there was a change in the selective constraints acting on the CP sHSPs.}, }
@article {pmid10580277, year = {1999}, author = {Ugalde, RA}, title = {Intracellular lifestyle of Brucella spp. Common genes with other animal pathogens, plant pathogens, and endosymbionts.}, journal = {Microbes and infection}, volume = {1}, number = {14}, pages = {1211-1219}, doi = {10.1016/s1286-4579(99)00240-3}, pmid = {10580277}, issn = {1286-4579}, mesh = {Animals ; Bacterial Adhesion ; Brucella/chemistry/*genetics/growth &amp; development/metabolism/pathogenicity ; Cells/metabolism/microbiology ; Genome, Bacterial ; Glucans/metabolism ; Humans ; Lipopolysaccharides ; Plants/microbiology ; Virulence ; }, abstract = {Brucella spp. are intracellular pathogens that belong, like Agrobacterium, Rhizobium and Rickettsia, to the alpha-2-subgroup of proteobacteria. The genome organization of most Brucella spp. is characterized by the presence of two chromosomes. The intracellular lifestyle of Brucella, as well as the possible genes involved in pathogenesis and host cell signaling, are discussed, including the presence of genes with high similarity to those from other animal pathogens, plant pathogens and endosymbionts.}, }
@article {pmid10555290, year = {1999}, author = {Clark, MA and Moran, NA and Baumann, P}, title = {Sequence evolution in bacterial endosymbionts having extreme base compositions.}, journal = {Molecular biology and evolution}, volume = {16}, number = {11}, pages = {1586-1598}, doi = {10.1093/oxfordjournals.molbev.a026071}, pmid = {10555290}, issn = {0737-4038}, mesh = {AT Rich Sequence ; Amino Acid Substitution ; Base Sequence ; Buchnera/*genetics ; DNA Primers ; *Evolution, Molecular ; }, abstract = {A major limitation on ability to reconstruct bacterial evolution is the lack of dated ancestors that might be used to evaluate and calibrate molecular clocks. Vertically transmitted symbionts that have cospeciated with animal hosts offer a firm basis for calibrating sequence evolution in bacteria, since fossils of the hosts can be used to date divergence events. Sequences for a functionally diverse set of genes have been obtained for bacterial endosymbionts (Buchnera) from two pairs of aphid host species, each pair diverging 50-70 MYA. Using these dates and estimated numbers of Buchnera generations per year, we calculated rates of base substitution for neutral and selected sites of protein-coding genes and overall rates for rRNA genes. Buchnera shows homogeneity among loci with regard to synonymous rate. The Buchnera synonymous rate is about twice that for low-codon-bias genes of Escherichia coli-Salmonella typhimurium on an absolute timescale, and fourfold higher on a generational timescale. Nonsynonymous substitutions show a greater rate disparity in favor of Buchnera, a result consistent with a genomewide decrease in selection efficiency in Buchnera. Ratios of synonymous to nonsynonymous substitutions differ for the two pairs of Buchnera, indicating that selection efficiency varies among lineages. Like numerous other intracellular bacteria, such as Rickettsia and Wolbachia, Buchnera has accumulated amino acids with codons rich in A or T. Phylogenetic reconstruction of amino acid replacements indicates that replacements yielding increased A + T predominated early in the evolution of Buchnera, with the trend slowing or stopping during the last 50 Myr. This suggests that base composition in Buchnera has approached a limit enforced by selective constraint acting on protein function.}, }
@article {pmid10528878, year = {1999}, author = {Winiecka-Krusnell, J and Linder, E}, title = {Free-living amoebae protecting Legionella in water: the tip of an iceberg?.}, journal = {Scandinavian journal of infectious diseases}, volume = {31}, number = {4}, pages = {383-385}, doi = {10.1080/00365549950163833}, pmid = {10528878}, issn = {0036-5548}, mesh = {Amoeba/*microbiology ; Animals ; *Ecosystem ; Humans ; Legionella/*isolation &amp; purification ; Legionellosis/microbiology/transmission ; *Water Microbiology ; }, abstract = {Bacteria are a main food source for free-living amoebae inhabiting aquatic systems. Some bacteria however, have the ability to prevent intracellular destruction and can survive and grow in amoebic cells as endosymbionts. Free-living amoebae are well adapted to their hostile environmental conditions and are resistant to both desiccation, elevated temperatures and various disinfectants. For their endosymbionts, amoebae represent perfect vectors, providing both protection against adverse environmental conditions and transportation. There is increasing interest in the potential role of free-living amoebae as reservoirs and vectors of pathogenic bacteria. The best known of such pathogenic bacteria is Legionella, and several studies provide evidence for the importance of the amoeba-bacterium relationship in the biology and epidemiology of pneumonia caused by this pathogen. Although the relative importance of endosymbiosis of this kind is unknown when it comes to other human bacterial infections and the exact role of amoebic hosts in bacterial survival, multiplication and transmission in the environment is still poorly understood, naming free-living amoebae the "Trojan horses" of the microbial world is appropriate.}, }
@article {pmid10527925, year = {1999}, author = {Delwiche, CF}, title = {Tracing the Thread of Plastid Diversity through the Tapestry of Life.}, journal = {The American naturalist}, volume = {154}, number = {S4}, pages = {S164-S177}, doi = {10.1086/303291}, pmid = {10527925}, issn = {1537-5323}, abstract = {Plastids (chloroplasts) are endosymbiotic organelles derived from previously free-living cyanobacteria. They are dependent on their host cell to the degree that the majority of the proteins expressed in the plastid are encoded in the nuclear genome of the host cell, and it is this genetic dependency that distinguishes organelles from obligate endosymbionts. Reduction in the size of the plastid genome has occurred via gene loss, substitution of nuclear genes, and gene transfer. The plastids of Chlorophyta and plants, Rhodophyta, and Glaucocystophyta are primary plastids (i.e., derived directly from a cyanobacterium). These three lineages may or may not be descended from a single endosymbiotic event. All other lineages of plastids have acquired their plastids by secondary (or tertiary) endosymbiosis, in which a eukaryote already equipped with plastids is preyed upon by a second eukaryote. Considerable gene transfer has occurred among genomes and, at times, between organisms. The eukaryotic crown group Alveolata has a particularly complex history of plastid acquisition.}, }
@article {pmid10525534, year = {1999}, author = {Walker, MB and Roy, LM and Coleman, E and Voelker, R and Barkan, A}, title = {The maize tha4 gene functions in sec-independent protein transport in chloroplasts and is related to hcf106, tatA, and tatB.}, journal = {The Journal of cell biology}, volume = {147}, number = {2}, pages = {267-276}, pmid = {10525534}, issn = {0021-9525}, support = {R01 GM48179/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Bacterial Proteins/genetics ; Biological Transport/genetics ; Chloroplasts/genetics/*metabolism ; Genes, Plant ; Membrane Proteins/*genetics/metabolism ; Molecular Sequence Data ; Plant Proteins/*genetics/metabolism ; Zea mays/genetics/*metabolism ; }, abstract = {Proteins are translocated across the chloroplast thylakoid membrane by a variety of mechanisms. Some proteins engage a translocation machinery that is derived from the bacterial Sec export system and require an interaction with a chloroplast-localized SecA homologue. Other proteins engage a machinery that is SecA-independent, but requires a transmembrane pH gradient. Recently, a counterpart to this Delta pH mechanism was discovered in bacteria. Genetic studies revealed that one maize protein involved in this mechanism, HCF106, is related in both structure and function to the bacterial tatA and tatB gene products. We describe here the mutant phenotype and molecular cloning of a second maize gene that functions in the Delta pH mechanism. This gene, thylakoid assembly 4 (tha4), is required specifically for the translocation of proteins that engage the Delta pH pathway. The sequence of the tha4 gene product resembles those of the maize hcf106 gene and the bacterial tatA and tatB genes. Sequence comparisons suggest that tha4 more closely resembles tatA, and hcf106 more closely resembles tatB. These findings support the notion that this sec-independent translocation mechanism has been highly conserved during the evolution of eucaryotic organelles from bacterial endosymbionts.}, }
@article {pmid10511685, year = {1999}, author = {Taylor, MJ and Hoerauf, A}, title = {Wolbachia bacteria of filarial nematodes.}, journal = {Parasitology today (Personal ed.)}, volume = {15}, number = {11}, pages = {437-442}, doi = {10.1016/s0169-4758(99)01533-1}, pmid = {10511685}, issn = {0169-4758}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Arthropods/microbiology ; Brugia malayi/*microbiology/ultrastructure ; Female ; Filariasis/drug therapy/immunology/microbiology ; Immunohistochemistry ; Male ; Microscopy, Electron ; Onchocerca volvulus/*microbiology/ultrastructure ; Phylogeny ; Symbiosis/genetics ; Wolbachia/*growth &amp; development ; Wuchereria bancrofti/*microbiology/ultrastructure ; }, abstract = {The finding that the intracellular bacteria of filarial nematodes are related to the Wolbachia symbionts of arthropods has generated great interest. Here, Mark Taylor and Achim Hoerauf review recent studies by several groups on the structure, distribution and phylogeny of these endosymbionts, and discuss the potential role for these bacteria in filarial disease and as a target for chemotherapy.}, }
@article {pmid10489345, year = {1999}, author = {van der Wilk, F and Dullemans, AM and Verbeek, M and van den Heuvel, JF}, title = {Isolation and characterization of APSE-1, a bacteriophage infecting the secondary endosymbiont of Acyrthosiphon pisum.}, journal = {Virology}, volume = {262}, number = {1}, pages = {104-113}, doi = {10.1006/viro.1999.9902}, pmid = {10489345}, issn = {0042-6822}, mesh = {Animals ; Aphids/ultrastructure/*virology ; Bacteriophages/*genetics/*isolation &amp; purification/ultrastructure ; Genome, Viral ; Microscopy, Electron ; Molecular Sequence Data ; Open Reading Frames/genetics ; Peas/*parasitology ; Podoviridae/genetics ; *Symbiosis ; Virion/chemistry/genetics/isolation &amp; purification ; }, abstract = {A bacteriophage infecting the secondary endosymbiont of the pea aphid Acyrthosiphon pisum was isolated and characterized. The phage was tentatively named bacteriophage APSE-1, for bacteriophage 1 of the A. pisum secondary endosymbiont. The APSE-1 phage particles morphologically resembled those of species of the Podoviridae. The complete nucleotide sequence of the bacteriophage APSE-1 genome was elucidated, and its genomic organization was deduced. The genome consists of a circularly permuted and terminally redundant double-stranded DNA molecule of 36524 bp. Fifty-four open reading frames, putatively encoding proteins with molecular masses of more than 8 kDa, were distinguished. ORF24 was identified as the gene coding for the major head protein by N-terminal amino acid sequencing of the protein. Comparison of APSE-1 sequences with bacteriophage-derived sequences present in databases revealed the putative function of 24 products, including the lysis proteins, scaffolding protein, transfer proteins, and DNA polymerase. This is the first report of a phage infecting an endosymbiont of an arthropod.}, }
@article {pmid10486984, year = {1999}, author = {Keeling, PJ and Deane, JA and Hink-Schauer, C and Douglas, SE and Maier, UG and McFadden, GI}, title = {The secondary endosymbiont of the cryptomonad Guillardia theta contains alpha-, beta-, and gamma-tubulin genes.}, journal = {Molecular biology and evolution}, volume = {16}, number = {9}, pages = {1308-1313}, doi = {10.1093/oxfordjournals.molbev.a026221}, pmid = {10486984}, issn = {0737-4038}, mesh = {Base Sequence ; DNA Primers/genetics ; Eukaryota/*genetics ; Evolution, Molecular ; *Genes, Plant ; Molecular Sequence Data ; Phylogeny ; Rhodophyta/genetics ; Species Specificity ; Symbiosis/*genetics ; Tubulin/*genetics ; }, abstract = {Cryptomonads have acquired photosynthesis through secondary endosymbiosis: they have engulfed and retained a photosynthetic eukaryote. The remnants of this autotrophic symbiont are severely reduced, but a small volume of cytoplasm surrounding the plastid persists, along with a residual nucleus (the nucleomorph) that encodes only a few hundred genes. We characterized tubulin genes from the cryptomonad Guillardia theta. Despite the apparent absence of microtubules in the endosymbiont, we recovered genes encoding alpha-, beta-, and gamma-tubulins from the nucleomorph genome of G. theta. The presence of tubulin genes in the nucleomorph indicates that some component of the cytoskeleton is still present in the cryptomonad symbiont despite the fact that very little cytoplasm remains, no mitosis is known in the nucleomorph, and microtubules have never been observed anywhere in the symbiont. Phylogenetic analyses with nucleomorph alpha- and beta-tubulins support the origin of the cryptomonad nucleomorph from a red alga. We also characterized alpha and beta-tubulins from the host nucleus of G. theta and compared these with tubulins we isolated from two flagellates, Goniomonas truncata and Cyanophora paradoxa, previously proposed to be related to the cryptomonad host. Phylogenetic analyses support a relationship between the cryptomonad host and Goniomonas but do not support any relationship between cryptomonads and Cyanophora.}, }
@article {pmid10469257, year = {1999}, author = {Van Meer, MM and Witteveldt, J and Stouthamer, R}, title = {Phylogeny of the arthropod endosymbiont Wolbachia based on the wsp gene.}, journal = {Insect molecular biology}, volume = {8}, number = {3}, pages = {399-408}, doi = {10.1046/j.1365-2583.1999.83129.x}, pmid = {10469257}, issn = {0962-1075}, mesh = {Animals ; Arthropods/parasitology ; Bacterial Outer Membrane Proteins/*genetics ; Base Sequence ; DNA Primers ; DNA, Bacterial ; *Genes, Bacterial ; Molecular Sequence Data ; Phenotype ; Phylogeny ; Rickettsiaceae/*classification/genetics ; Symbiosis ; }, abstract = {Bacteria of the genus Wolbachia (Rickettsiae) are widespread in arthropods and can induce cytoplasmic incompatibility (CI), thelytoky (T) or feminization (F) in their host. Recent research on the wsp gene of mainly CI inducing Wolbachia has shown that this gene evolves at a much faster rate than previously sequenced genes such as 16S or ftsZ. As a result this gene appears to be very useful in subdividing the Wolbachia and twelve groups have been distinguished to date. Here we extend the Wolbachia wsp data set with fifteen T-Wolbachia, one F-Wolbachia and three other CI-Wolbachia strains. The results showed: (i) the addition of seven groups; (ii) no relation between host phenotype and Wolbachia phylogenetic position; and (iii) possible horizontal Wolbachia transfer between the moth Ephestia kuehniella and its parasitoid Trichogramma spp.}, }
@article {pmid10461382, year = {1999}, author = {McFadden, GI}, title = {Plastids and protein targeting.}, journal = {The Journal of eukaryotic microbiology}, volume = {46}, number = {4}, pages = {339-346}, doi = {10.1111/j.1550-7408.1999.tb04613.x}, pmid = {10461382}, issn = {1066-5234}, mesh = {Animals ; Biological Transport ; Eukaryota/genetics/*metabolism ; Genes ; Plastids/*genetics/*metabolism ; Protein Sorting Signals/metabolism ; Proteins/*metabolism ; Protozoan Proteins/metabolism ; Symbiosis ; }, abstract = {Plastids with two bounding membranes--as exemplified by red algae, green algae, plants, and glaucophytes--derive from primary endosymbiosis; a process involving engulfment and retention of a cyanobacterium by a phagotrophic eukaryote. Plastids with more than two bounding membranes (such as those of euglenoids, dinoflagellates, heterokonts, haptopytes, apicomplexa, cryptomonads, and chlorarachniophytes) probably arose by secondary endosymbiosis, in which a eukaryotic alga (itself the product of primary endosymbiosis) was engulfed and retained by a phagotroph. Secondary endosymbiosis transfers photosynthetic capacity into heterotrophic lineages, has apparently occurred numerous times, and has created several major eukaryotic lineages comprising upwards of 42,600 species. Plastids acquired by secondary endosymbiosis are sometimes referred to as "second-hand." Establishment of secondary endosymbioses has involved transfer of genes from the endosymbiont nucleus to the secondary host nucleus. Limited gene transfer could initially have served to stabilise the endosymbioses, but it is clear that the transfer process has been extensive, leading in many cases to the complete disappearance of the endosymbiont nucleus. One consequence of these gene transfers is that gene products required in the plastid must be targeted into the organelle across multiple membranes: at least three for stromal proteins in euglenoids and dinoflagellates, and across five membranes in the case of thylakoid lumen proteins in plastids with four bounding membranes. Evolution of such targeting mechanisms was obviously a key step in the successful establishment of each different secondary endosymbiosis. Analysis of targeted proteins in the various organisms now suggests that a similar system is used by each group. However, rather than interpreting this similarity as evidence of an homologous origin, I believe that targeting has evolved convergently by combining and recycling existing protein trafficking mechanisms already existing in the endosymbiont and host. Indeed, by analyzing the multiple motifs in targeting sequences of some genes it is possible to infer that they originated in the plastid genome, transferred from there into the primary host nucleus, and subsequently moved into the secondary host nucleus. Thus, each step of the targeting process in "second-hand" plastids recapitulates the gene's previous intracellular transfers.}, }
@article {pmid10430591, year = {1999}, author = {Rigaud, T and Bouchon, D and Souty-Grosset, C and Raimond, R}, title = {Mitochondrial DNA polymorphism, sex ratio distorters and population genetics in the isopod Armadillidium vulgare.}, journal = {Genetics}, volume = {152}, number = {4}, pages = {1669-1677}, pmid = {10430591}, issn = {0016-6731}, mesh = {Animals ; Crustacea/*genetics/microbiology/physiology ; DNA, Mitochondrial/*genetics ; Female ; France ; Genetics, Population ; Male ; Plasmids/*genetics ; Rickettsiaceae/*genetics ; *Sex Ratio ; }, abstract = {Two maternally inherited sex ratio distorters (SRD) impose female-biased sex ratios on the wood louse Armadillidium vulgare by feminizing putative males. These SRD are (i) an intracytoplasmic bacterium of the genus Wolbachia, and (ii) another non-Mendelian element of unknown nature: the f element. Mitochondrial DNA variation was investigated in A. vulgare field populations to trace the evolution of host-SRD relationships and to investigate the effect of SRD on host cytoplasmic polymorphism. The Wolbachia endosymbionts showed no polymorphism in their ITS2 sequence and were associated with two closely related mitochondrial types. This situation probably reflects a single infection event followed by a slight differentiation of mitochondria. There was no association between the f element and a given mitochondrial type, which may confirm the fact that this element can be partially paternally transmitted. The spreading of a maternally inherited SRD in a population should reduce the mitochondrial diversity by a hitchhiking process. In A. vulgare, however, a within-population mtDNA polymorphism was often found, because of the deficient spread of Wolbachia and the partial paternal inheritance of the f element. The analysis of molecular variance indicated that A. vulgare populations are genetically structured, but without isolation by distance.}, }
@article {pmid10388713, year = {1999}, author = {Millikan, DS and Felbeck, H and Stein, JL}, title = {Identification and characterization of a flagellin gene from the endosymbiont of the hydrothermal vent tubeworm Riftia pachyptila.}, journal = {Applied and environmental microbiology}, volume = {65}, number = {7}, pages = {3129-3133}, pmid = {10388713}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*genetics/metabolism ; Bacterial Physiological Phenomena ; Blotting, Western ; Escherichia coli/genetics/*metabolism ; Flagellin/*genetics/isolation &amp; purification/metabolism ; *Genes, Bacterial ; Microscopy, Electron ; Molecular Sequence Data ; Movement ; Polychaeta/*microbiology ; *Symbiosis ; }, abstract = {The bacterial endosymbionts of the hydrothermal vent tubeworm Riftia pachyptila play a key role in providing their host with fixed carbon. Results of prior research suggest that the symbionts are selected from an environmental bacterial population, although a free-living form has been neither cultured from nor identified in the hydrothermal vent environment. To begin to assess the free-living potential of the symbiont, we cloned and characterized a flagellin gene from a symbiont fosmid library. The symbiont fliC gene has a high degree of homology with other bacterial flagellin genes in the amino- and carboxy-terminal regions, while the central region was found to be nonconserved. A sequence that was homologous to that of a consensus sigma28 RNA polymerase recognition site lay upstream of the proposed translational start site. The symbiont protein was expressed in Escherichia coli, and flagella were observed by electron microscopy. A 30,000-Mr protein subunit was identified in whole-cell extracts by Western blot analysis. These results provide the first direct evidence of a motile free-living stage of a chemoautotrophic symbiont and support the hypothesis that the symbiont of R. pachyptila is acquired with each new host generation.}, }
@article {pmid10371035, year = {1999}, author = {Brennicke, A and Marchfelder, A and Binder, S}, title = {RNA editing.}, journal = {FEMS microbiology reviews}, volume = {23}, number = {3}, pages = {297-316}, doi = {10.1111/j.1574-6976.1999.tb00401.x}, pmid = {10371035}, issn = {0168-6445}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Biological Evolution ; Cell Nucleus/metabolism ; Mitochondria/metabolism ; Molecular Sequence Data ; Plants/metabolism ; Plastids/metabolism ; RNA Editing/genetics/*physiology ; RNA, Messenger/chemistry/metabolism ; }, abstract = {The term RNA editing describes those molecular processes in which the information content is altered in an RNA molecule. To date such changes have been observed in tRNA. rRNA and mRNA molecules of eukaryotes, but not prokaryotes. The demonstration of RNA editing in prokaryotes may only be a matter of time, considering the range of species in which the various RNA editing processes have been found. RNA editing occurs in the nucleus, as well as in mitochondria and plastids, which are thought to have evolved from prokaryotic-like endosymbionts. Most of the RNA editing processes, however, appear to be evolutionarily recent acquisitions that arose independently. The diversity of RNA editing mechanisms includes nucleoside modifications such as C to U and A to I deaminations, as well as non-templated nucleotide additions and insertions. RNA editing in mRNAs effectively alters the amino acid sequence of the encoded protein so that it differs from that predicted by the genomic DNA sequence.}, }
@article {pmid10359795, year = {1999}, author = {Heddi, A and Grenier, AM and Khatchadourian, C and Charles, H and Nardon, P}, title = {Four intracellular genomes direct weevil biology: nuclear, mitochondrial, principal endosymbiont, and Wolbachia.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {96}, number = {12}, pages = {6814-6819}, pmid = {10359795}, issn = {0027-8424}, mesh = {Biological Evolution ; DNA, Mitochondrial ; Gene Expression Regulation ; Genome, Bacterial ; *Genome, Plant ; Molecular Sequence Data ; Oryza/*genetics ; Symbiosis/*genetics ; }, abstract = {Cell physiology in the weevil Sitophilus oryzae is coordinated by three integrated genomes: nuclear, mitochondrial, and the "S. oryzae principal endosymbiont" (SOPE). SOPE, a cytoplasmic bacterium (2 x 10(3) bacteria per specialized bacteriocyte cell and 3 x 10(6) bacteria per weevil) that belongs to the proteobacteria gamma3-subgroup, is present in all weevils studied. We discovered a fourth prokaryotic genome in somatic and germ tissues of 57% of weevil strains of three species, S. oryzae, Sitophilus zeamais, and Sitophilus granarius, distributed worldwide. We assigned this Gram-negative prokaryote to the Wolbachia group (alpha-proteobacteria), on the basis of 16S rDNA sequence and fluorescence in situ DNA-RNA hybridization (FISH). Both bacteria, SOPE and Wolbachia, were selectively eliminated by combined heat and antibiotic treatments. Study of bacteria involvement in this insect's genetics and physiology revealed that SOPE, which induces the specific differentiation of the bacteriocytes, increases mitochondrial oxidative phosphorylation through the supply of pantothenic acid and riboflavin. Elimination of this gamma3-proteobacterium impairs many physiological traits. By contrast, neither the presence nor the absence of Wolbachia significantly affects the weevil's physiology. Wolbachia, disseminated throughout the body cells, is in particularly high density in the germ cells, where it causes nucleocytoplasmic incompatibility. The coexistence of two distinct types of intracellular proteobacteria at different levels of symbiont integration in insects illustrates the genetic complexity of animal tissue. Furthermore, evolutionary timing can be inferred: first nucleocytoplasm, then mitochondria, then SOPE, and finally Wolbachia. Symbiogenesis, the genetic integration of long-term associated members of different species, in the weevil appears to be a mechanism of speciation (with Wolbachia) and provides a means for animals to acquire new genes that permit better adaptation to the environment (with SOPE).}, }
@article {pmid10354621, year = {1999}, author = {Rigaud, T}, title = {Further endosymbiont diversity: a tree hiding in the forest?.}, journal = {Trends in ecology &amp; evolution}, volume = {14}, number = {6}, pages = {212-213}, doi = {10.1016/s0169-5347(99)01599-2}, pmid = {10354621}, issn = {1872-8383}, }
@article {pmid10347020, year = {1999}, author = {Zepp Falz, K and Holliger, C and Grosskopf, R and Liesack, W and Nozhevnikova, AN and Müller, B and Wehrli, B and Hahn, D}, title = {Vertical distribution of methanogens in the anoxic sediment of Rotsee (Switzerland).}, journal = {Applied and environmental microbiology}, volume = {65}, number = {6}, pages = {2402-2408}, pmid = {10347020}, issn = {0099-2240}, mesh = {Anaerobiosis ; Archaea/classification/genetics/*isolation &amp; purification ; DNA, Archaeal/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; *Ecosystem ; Euryarchaeota/classification/genetics/*isolation &amp; purification ; Fresh Water ; Geologic Sediments/*microbiology ; In Situ Hybridization ; Methane/metabolism ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/genetics ; Switzerland ; *Water Microbiology ; }, abstract = {Anoxic sediments from Rotsee (Switzerland) were analyzed for the presence and diversity of methanogens by using molecular tools and for methanogenic activity by using radiotracer techniques, in addition to the measurement of chemical profiles. After PCR-assisted sequence retrieval of the 16S rRNA genes (16S rDNA) from the anoxic sediment of Rotsee, cloning, and sequencing, a phylogenetic analysis identified two clusters of sequences and four separated clones. The sequences in cluster 1 grouped with those of Methanosaeta spp., whereas the sequences in cluster 2 comprised the methanogenic endosymbiont of Plagiopyla nasuta. Discriminative oligonucleotide probes were constructed against both clusters and two of the separated clones. These probes were used subsequently for the analysis of indigenous methanogens in a core of the sediment, in addition to domain-specific probes against members of the domains Bacteria and Archaea and the fluorescent stain 4', 6-diamidino-2-phenylindole (DAPI), by fluorescent in situ hybridization. After DAPI staining, the highest microbial density was obtained in the upper sediment layer; this density decreased with depth from (1.01 +/- 0.25) x 10(10) to (2.62 +/- 0.58) x 10(10) cells per g of sediment (dry weight). This zone corresponded to that of highest metabolic activity, as indicated by the ammonia, alkalinity, and pH profiles, whereas the methane profile was constant. Probes Eub338 and Arch915 detected on average 16 and 6% of the DAPI-stained cells as members of the domains Bacteria and Archaea, respectively. Probe Rotcl1 identified on average 4% of the DAPI-stained cells as Methanosaeta spp., which were present throughout the whole core. In contrast, probe Rotcl2 identified only 0.7% of the DAPI-stained cells as relatives of the methanogenic endosymbiont of P. nasuta, which was present exclusively in the upper 2 cm of the sediment. Probes Rotp13 and Rotp17 did not detect any cells. The spatial distribution of the two methanogenic populations corresponded well to the methane production rates determined by incubation with either [14C]acetate or [14C]bicarbonate. Methanogenesis from acetate accounted for almost all of the total methane production, which concurs with the predominance of acetoclastic Methanosaeta spp. that represented on average 91% of the archaeal population. Significant hydrogenotrophic methanogenesis was found only in the organically enriched upper 2 cm of the sediment, where the probably hydrogenotrophic relatives of the methanogenic endosymbiont of P. nasuta, accounting on average for 7% of the archaeal population, were also detected.}, }
@article {pmid10342099, year = {1999}, author = {Corsaro, D and Venditti, D and Padula, M and Valassina, M}, title = {Intracellular life.}, journal = {Critical reviews in microbiology}, volume = {25}, number = {1}, pages = {39-79}, doi = {10.1080/10408419991299167}, pmid = {10342099}, issn = {1040-841X}, mesh = {Animals ; Biological Evolution ; Host-Parasite Interactions/physiology ; Models, Biological ; Organelles/physiology ; Parasites/*pathogenicity/*physiology ; Symbiosis/*physiology ; Virulence ; }, abstract = {Intracellular parasites and endosymbionts are present in almost all forms of life, including bacteria. Some eukaryotic organelles are believed to be derived from ancestral endosymbionts. Parasites and symbionts show several adaptations to intracellular life. A comparative analysis of their biology suggests some general considerations involved in adapting to intracellular life and reveals a number of independently achieved strategies for the exploitation of an intracellular habitat. Symbioses mainly based on a form of syntrophy may have led to the establishment of unique physiological systems. Generally, a symbiont can be considered to be an attenuated pathogen. The combination of morphological studies, molecular phylogenetic analyses, and palaeobiological data has led to considerable improvement in the understanding of intracellular life evolution. Comparing host and symbiont phylogenies could lead to an explanation of the evolutionary history of symbiosis. These studies also provide strong evidences for the endosymbiogenesis of the eukaryotic cell. Indeed, an eubacterial origin for mitochondria and plastids is well accepted and is suggested for other organelles. The expansion of intracellular living associations is presented, with a particular emphasis on peculiar aspects and/or recent data, providing a global evaluation.}, }
@article {pmid10331254, year = {1999}, author = {Wernegreen, JJ and Moran, NA}, title = {Evidence for genetic drift in endosymbionts (Buchnera): analyses of protein-coding genes.}, journal = {Molecular biology and evolution}, volume = {16}, number = {1}, pages = {83-97}, doi = {10.1093/oxfordjournals.molbev.a026040}, pmid = {10331254}, issn = {0737-4038}, mesh = {Animals ; Aphids/microbiology ; Bacteria/*genetics ; Bacterial Proteins/*genetics ; Chaperonin 60/genetics ; Codon/genetics ; Escherichia coli/genetics ; Evolution, Molecular ; Female ; Gene Frequency ; *Genes, Bacterial ; Mutation ; Symbiosis ; }, abstract = {Buchnera, the bacterial endosymbionts of aphids, undergo severe population bottlenecks during maternal transmission through their hosts. Previous studies suggest an increased effect of drift within these strictly asexual, small populations, resulting in an increased fixation of slightly deleterious mutations. This study further explores sequence evolution in Buchnera using three approaches. First, patterns of codon usage were compared across several homologous Escherichia coli and Buchnera loci, in order to test the prediction that selection for the use of optimal codons is less effective in small populations. A chi 2-based measure of codon bias was developed to adjust for the overall A + T richness of silent positions in the endosymbionts. In contrast to E. coli homologues, adaptive codon bias across Buchnera loci is markedly low, and patterns of codon usage lack a strong relationship with gene expression level. These data suggest that codon usage in Buchnera has been shaped largely by mutational pressure and drift rather than by selection for translational efficiency. One exception to the overall lack of bias is groEL, which is known to be constitutively overexpressed in Buchnera and other endosymbionts. Second, relative-rate tests show elevated rates of sequence evolution of numerous protein-coding loci across Buchnera, compared to E. coli. Finally, consistently higher ratios of nonsynonymous to synonymous substitutions in Buchnera loci relative to the enteric bacteria strongly suggest the accumulation of nonsynonymous substitutions in endosymbiont lineages. Combined, these results suggest a decreased effectiveness of purifying selection in purging endosymbiont populations of slightly deleterious mutations, particularly those affecting codon usage and amino acid identity.}, }
@article {pmid10222188, year = {1999}, author = {Meszaros, A and Bigger, C}, title = {Qualitative and quantitative study of wound healing processes in the coelenterate, Plexaurella fusifera: spatial, temporal, and environmental (light attenuation) influences.}, journal = {Journal of invertebrate pathology}, volume = {73}, number = {3}, pages = {321-331}, doi = {10.1006/jipa.1999.4851}, pmid = {10222188}, issn = {0022-2011}, support = {RR08205/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Cnidaria/cytology/*physiology ; Wound Healing ; }, abstract = {Following injury, the Caribbean soft coral, Plexaurella fusifera, forms an epithelial front containing amoebocytes and zooxanthellae, a photosynthetic endosymbiont. Amoebocytes may be responsible for extruding the connective mesogleal fibers necessary for regeneration of tissue and zooxanthellae may provide the energy for repair. This study examined the effects of time, space, and environment (light attenuation) on wound healing in this coral species and quantitatively confirmed the increase of amoebocyte concentrations in the injured area. A wound was made on coral branchlets by removing approximately 4.5 mm of coenenchyme. At assigned times after injury, samples were collected for gross morphological and histological evaluation, in which amoebocytes and zooxanthellae concentrations were quantified within 0.009 mm3 of tissue. Overall amoebocyte numbers within uninjured and wounded tissue were similar. However, when numbers of amoebocytes per area of injured tissue were calculated and compared to those of uninjured tissue, 82.4% more amoebocytes occurred at distances 0-0.5 mm from the wound edge, while areas of tissue >2 mm from the wound edge were occupied by fewer amoebocytes. Overall increases in concentrations of zooxanthellae also occurred within wounded coral, but no apparent temporal, spatial, or light-related pattern was detected. Therefore, this study supports the conjecture that amoebocyte accumulation at a wound site is an effect of cells migrating from uninjured tissue adjacent to the wounded edge. In addition, this movement occurs regardless of light attenuation. Light, which in this study was confined to ranges between 70 and 545 microE s-1 m-2, did not significantly affect the wound healing process in regard to either closure or cellular concentrations.}, }
@article {pmid10221636, year = {1999}, author = {Bandi, C and McCall, JW and Genchi, C and Corona, S and Venco, L and Sacchi, L}, title = {Effects of tetracycline on the filarial worms Brugia pahangi and Dirofilaria immitis and their bacterial endosymbionts Wolbachia.}, journal = {International journal for parasitology}, volume = {29}, number = {2}, pages = {357-364}, doi = {10.1016/s0020-7519(98)00200-8}, pmid = {10221636}, issn = {0020-7519}, mesh = {Animals ; Anti-Bacterial Agents/*pharmacology ; Brugia/*drug effects/microbiology ; Dirofilaria/*drug effects/microbiology ; Dogs ; Elephantiasis, Filarial/veterinary ; Female ; Gerbillinae/parasitology ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction/methods ; Rickettsiaceae/*drug effects/genetics/isolation &amp; purification ; Symbiosis ; Tetracycline/*pharmacology ; }, abstract = {Wolbachia endosymbiotic bacteria have been shown to be widespread among filarial worms and could thus play some role in the biology of these nematodes. Indeed, tetracycline has been shown to inhibit both the development of adult worms from third-stage larvae and the development of the microfilaraemia in jirds infected with Brugia pahangi. The possibility that these effects are related to the bacteriostatic activity of tetracycline on Wolbachia symbionts should be considered. Here we show that tetracycline treatment is very effective in blocking embryo development in two filarial nematodes, B. pahangi and Dirofilaria immitis. Embryo degeneration was documented by TEM, while the inhibition of the transovarial transmission of Wolbachia was documented by PCR. Phylogenetic analysis on the ssrDNA sequence of the Wolbachia of B. pahangi confirms that the phylogeny of the bacterial endosymbionts is consistent with that of the host worms. The possibility that tetracycline inhibition of embryo development in B. pahangi and D. immitis is determined by cytoplasmic incompatibility is discussed.}, }
@article {pmid10220875, year = {1999}, author = {de Souza, W and Motta, MC}, title = {Endosymbiosis in protozoa of the Trypanosomatidae family.}, journal = {FEMS microbiology letters}, volume = {173}, number = {1}, pages = {1-8}, doi = {10.1111/j.1574-6968.1999.tb13477.x}, pmid = {10220875}, issn = {0378-1097}, mesh = {Animals ; Bacteria/growth &amp; development/isolation &amp; purification/ultrastructure ; *Bacterial Physiological Phenomena ; Phylogeny ; *Symbiosis ; Trypanosomatina/*microbiology/ultrastructure ; }, abstract = {A small number of trypanosomatids present bacterium endosymbionts in the cytoplasm, which divide synchronously with the host cell. Crithidia oncopleti, Crithidia deanei. Crithidia desouzai, Blastocrithidia culicis and Herpetomonas roitmani are the best characterized species. The endosymbiont is surrounded by two membranes separated from each other by an electron-lucent space. The presence of the endosymbiont led to the appearance of morphological changes which include the lack of the paraflagellar rod associated to the axoneme, the morphology of the kinetoplast and the association of the sub-pellicular microtubules with portions of the protozoan plasma membrane. Aposymbiotic strains could be obtained by antibiotic treatment, opening the possibility to make comparative analysis of endosymbiont-containing an endosymbiont-free populations of the same species. It is clear that metabolic cycles are established between the prokaryiont and the host cell. The results obtained show that endosymbiont-containing species of trypanosomatids constitute an excellent model to study basic processes on the endosymbiont-host cell relationship and the origin of new organelles.}, }
@article {pmid10198437, year = {1999}, author = {Maruyama, K and Sato, N and Ohta, N}, title = {Conservation of structure and cold-regulation of RNA-binding proteins in cyanobacteria: probable convergent evolution with eukaryotic glycine-rich RNA-binding proteins.}, journal = {Nucleic acids research}, volume = {27}, number = {9}, pages = {2029-2036}, doi = {10.1093/nar/27.9.2029}, pmid = {10198437}, issn = {0305-1048}, mesh = {Amino Acid Sequence ; *Cold Temperature ; Cyanobacteria/*genetics ; Eukaryotic Cells ; *Evolution, Molecular ; *Gene Expression Regulation, Bacterial ; Glycine/*chemistry ; Humans ; Molecular Sequence Data ; Protein Conformation ; RNA-Binding Proteins/chemistry/*genetics/metabolism ; Sequence Homology, Amino Acid ; }, abstract = {The rbp gene family of the cyanobacterium Anabaena variabilis strain M3 consists of eight members that encode small RNA-binding proteins containing a single RNA recognition motif (RRM). Similar genes are found in the genomes of Synechocystis sp. PCC6803, Helicobacter pylori and Treponema pallidum, but are absent from the other completely sequenced prokaryotic genomes. The expression of the rbp genes of Anabaena is induced by low temperature, with the exception of the rbpD gene. We found four stretches of conserved sequences in the 5'-untranslated region of the cyanobacterial rbp genes that are known to be induced by low temperature. The cold-regulated Rbp proteins contain a short C-terminal glycine-rich domain. In this respect, these proteins are similar to plant and mammalian glycine-rich RNA-binding proteins (GRPs), which also contain a single RRM domain with a C-terminal glycine-rich domain and are highly expressed at low temperature. Detailed phylogenetic analysis showed, however, that the cyanobacterial Rbp proteins and the eukaryotic GRPs do not belong to a single lineage, but that the glycine-rich domains are likely to have been added independently. The cold-regulation of both types of proteins is also likely to have evolved independently. Furthermore, the chloroplast RNA-binding proteins are not likely to have originated from the Rbp proteins of endosymbiont cyanobacterium, but are supposed to have diverged from the GRPs. These results suggest that the cyanobacterial Rbp proteins and the eukaryotic GRPs are similar in both structure and regulation, but that this apparent similarity has resulted from convergent evolution.}, }
@article {pmid10087228, year = {1999}, author = {Morin, S and Ghanim, M and Zeidan, M and Czosnek, H and Verbeek, M and van den Heuvel, JF}, title = {A GroEL homologue from endosymbiotic bacteria of the whitefly Bemisia tabaci is implicated in the circulative transmission of tomato yellow leaf curl virus.}, journal = {Virology}, volume = {256}, number = {1}, pages = {75-84}, doi = {10.1006/viro.1999.9631}, pmid = {10087228}, issn = {0042-6822}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Chaperonin 60/chemistry/*physiology ; Escherichia coli/physiology ; Geminiviridae/*pathogenicity/physiology ; Gossypium/*virology ; Gram-Negative Bacteria/physiology/*virology ; Insect Vectors/physiology/*virology ; Insecta/*microbiology ; Lycopersicon esculentum/*virology ; Molecular Sequence Data ; Plant Diseases/virology ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis ; Virion/physiology ; }, abstract = {Evidence for the involvement of a Bemisia tabaci GroEL homologue in the transmission of tomato yellow leaf curl geminivirus (TYLCV) is presented. A approximately 63-kDa protein was identified in B. tabaci whole-body extracts using an antiserum raised against aphid Buchnera GroEL. The GroEL homologue was immunolocalized to a coccoid-shaped whitefly endosymbiont. The 30 N-terminal amino acids of the whitefly GroEL homologue showed 80% homology with that from different aphid species and GroEL from Escherichia coli. Purified GroEL from B. tabaci exhibited ultrastructural similarities to that of the endosymbiont from aphids and E. coli. In vitro ligand assays showed that tomato yellow leaf curl virus (TYLCV) particles displayed a specific affinity for the B. tabaci 63-kDa GroEL homologue. Feeding whiteflies anti-Buchnera GroEL antiserum before the acquisition of virions reduced TYLCV transmission to tomato test plants by >80%. In the haemolymph of these whiteflies, TYLCV DNA was reduced to amounts below the threshold of detection by Southern blot hybridization. Active antibodies were recovered from the insect haemolymph suggesting that by complexing the GoEL homologue, the antibody disturbed interaction with TYLCV, leading to degradation of the virus. We propose that GroEL of B. tabaci protects the virus from destruction during its passage through the haemolymph.}, }
@article {pmid10066161, year = {1999}, author = {Gray, MW and Burger, G and Lang, BF}, title = {Mitochondrial evolution.}, journal = {Science (New York, N.Y.)}, volume = {283}, number = {5407}, pages = {1476-1481}, doi = {10.1126/science.283.5407.1476}, pmid = {10066161}, issn = {0036-8075}, mesh = {Animals ; Archaea/genetics ; Bacteria/genetics ; *Biological Evolution ; DNA, Mitochondrial/chemistry/*genetics ; *Eukaryotic Cells/physiology/ultrastructure ; Evolution, Molecular ; Genes ; Mitochondria/*genetics ; Models, Biological ; Phylogeny ; Symbiosis ; }, abstract = {The serial endosymbiosis theory is a favored model for explaining the origin of mitochondria, a defining event in the evolution of eukaryotic cells. As usually described, this theory posits that mitochondria are the direct descendants of a bacterial endosymbiont that became established at an early stage in a nucleus-containing (but amitochondriate) host cell. Gene sequence data strongly support a monophyletic origin of the mitochondrion from a eubacterial ancestor shared with a subgroup of the alpha-Proteobacteria. However, recent studies of unicellular eukaryotes (protists), some of them little known, have provided insights that challenge the traditional serial endosymbiosis-based view of how the eukaryotic cell and its mitochondrion came to be. These data indicate that the mitochondrion arose in a common ancestor of all extant eukaryotes and raise the possibility that this organelle originated at essentially the same time as the nuclear component of the eukaryotic cell rather than in a separate, subsequent event.}, }
@article {pmid10028272, year = {1999}, author = {Dale, C and Maudlin, I}, title = {Sodalis gen. nov. and Sodalis glossinidius sp. nov., a microaerophilic secondary endosymbiont of the tsetse fly Glossina morsitans morsitans.}, journal = {International journal of systematic bacteriology}, volume = {49 Pt 1}, number = {}, pages = {267-275}, doi = {10.1099/00207713-49-1-267}, pmid = {10028272}, issn = {0020-7713}, mesh = {Aedes/microbiology ; Animals ; Carbon/metabolism ; Cell Line ; DNA, Bacterial/analysis ; Enterobacteriaceae/*classification/isolation &amp; purification ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {A secondary intracellular symbiotic bacterium was isolated from the haemolymph of the tsetse fly Glossina morsitans morsitans and cultured in Aedes albopictus cell line C6/36. Pure-culture isolation of this bacterium was achieved through the use of solid-phase culture under a microaerobic atmosphere. After isolation of strain M1T, a range of tests was performed to determine the phenotypic properties of this bacterium. Considering the results of these tests, along with the phylogenetic position of this micro-organism, it is proposed that this intracellular symbiont from G. m. morsitans should be classified in a new genus Sodalis gen. nov., as Sodalis glossinidius gen. nov., sp. nov. Strain M1T is the type strain for this new species.}, }
@article {pmid9990094, year = {1999}, author = {Kapranov, P and Jensen, TJ and Poulsen, C and de Bruijn, FJ and Szczyglowski, K}, title = {A protein phosphatase 2C gene, LjNPP2C1, from Lotus japonicus induced during root nodule development.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {96}, number = {4}, pages = {1738-1743}, pmid = {9990094}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Arabidopsis/enzymology/genetics ; Conserved Sequence ; Enzyme Induction ; Gene Expression Regulation, Developmental ; *Gene Expression Regulation, Plant ; Kinetics ; Molecular Sequence Data ; Phosphoprotein Phosphatases/chemistry/*genetics/metabolism ; Plant Development ; Plant Roots/growth &amp; development ; Plants/enzymology/*genetics ; Protein Phosphatase 2 ; Protein Phosphatase 2C ; RNA, Messenger/genetics ; *Saccharomyces cerevisiae Proteins ; Sequence Alignment ; Sequence Homology, Amino Acid ; Transcription, Genetic ; Transcriptional Activation ; }, abstract = {Symbiotic interactions between legumes and compatible strains of rhizobia result in root nodule formation. This new plant organ provides the unique physiological environment required for symbiotic nitrogen fixation by the bacterial endosymbiont and assimilation of this nitrogen by the plant partner. We have isolated two related genes (LjNPP2C1 and LjPP2C2) from the model legume Lotus japonicus that encode protein phosphatase type 2C (PP2C). Expression of the LjNPP2C1 gene was found to be enhanced specifically in L. japonicus nodules, whereas the LjPP2C2 gene was expressed at a similar level in nodules and roots. A glutathione S-transferase-LjNPP2C1 fusion protein was shown to have Mg2+- or Mn2+-dependent and okadaic acid-insensitive PP2C activity in vitro. A chimeric construct containing the full-length LjNPP2C1 cDNA, under the control of the Saccharomyces cerevisiae alcohol dehydrogenase promoter, was found to be able to complement a yeast PP2C-deficient mutant (pct1Delta). The transcript level of the LjNPP2C1 gene was found to increase significantly in mature nodules, and its highest expression level occurred after leghemoglobin (lb) gene induction, a molecular marker for late developmental events in nodule organogenesis. Expression of the LjNPP2C1 gene was found to be drastically altered in specific L. japonicus lines carrying monogenic-recessive mutations in symbiosis-related loci, suggesting that the product of the LjNPP2C1 gene may function at both early and late stages of nodule development.}, }
@article {pmid9929391, year = {1999}, author = {Otsuka, J and Terai, G and Nakano, T}, title = {Phylogeny of organisms investigated by the base-pair changes in the stem regions of small and large ribosomal subunit RNAs.}, journal = {Journal of molecular evolution}, volume = {48}, number = {2}, pages = {218-235}, doi = {10.1007/pl00006461}, pmid = {9929391}, issn = {0022-2844}, mesh = {Algorithms ; Animals ; *Base Pairing ; Evolution, Molecular ; Fungi/genetics ; Humans ; Models, Genetic ; *Mutation ; *Phylogeny ; Plants/genetics ; RNA, Ribosomal/*genetics ; }, abstract = {In order to obtain the evolutionary distance data that are as purely additive as possible, we have developed a novel method for evaluating the evolutionary distances from the base-pair changes in stem regions of ribosomal RNAs (rRNAs). The application of this method to small-subunit (SSU) and large-subunit (LSU) rRNAs provides the distance data, with which both the unweighted pair group method of analysis and the neighbor-joining method give almost the same tree topology of most organisms except for some Protoctista, thermophilic bacteria, parasitic organisms, and endosymbionts. Although the evolutionary distances calculated with LSU rRNAs are somewhat longer than those with SSU rRNAs, the difference, probably due to a slight difference in functional constraint, is substantially decreased when the distances are converted into the divergence times of organisms by the measure of the time scale estimated in each type of rRNAs. The divergence times of main branches agree fairly well with the geological record of organisms, at least after the appearance of oxygen-releasing photosynthesis, although the divergence times of Eukaryota, Archaebacteria, and Eubacteria are somewhat overestimated in comparison with the geological record of Earth formation. This result is explained by considering that the mutation rate is determined by the accumulation of misrepairs for DNA damage caused by radiation and that the effect of radiation had been stronger before the oxygen molecules became abundant in the atmosphere of the Earth.}, }
@article {pmid9929382, year = {1999}, author = {Charles, H and Ishikawa, H}, title = {Physical and genetic map of the genome of Buchnera, the primary endosymbiont of the pea aphid Acyrthosiphon pisum.}, journal = {Journal of molecular evolution}, volume = {48}, number = {2}, pages = {142-150}, doi = {10.1007/pl00006452}, pmid = {9929382}, issn = {0022-2844}, mesh = {Animals ; Aphids/*genetics ; Chromosome Mapping/methods ; *Genome ; Peas/*parasitology ; Restriction Mapping ; Symbiosis ; }, abstract = {The genome of Buchnera, an endosymbiotic bacterium of the pea aphid Acyrthosiphon pisum, was characterized by pulse-field gel electrophoresis (PFGE) as a circular DNA molecule of 657 kb. The enzymes I-CeuI, CpoI, ApaI, SmaI, NaeI, SacII, MluI, FspI, and NruI were used to cleave the DNA of Buchnera into fragments of suitable size for PFGE analysis. A physical map of the Buchnera genome, including restriction fragments from seven of these enzymes, was constructed using double cutting, partial digestion, and hybridization with linking fragments, and 29 genes and operons were localized on the map. In addition, the genomic map of Buchnera was compared with those of Escherichia coli and Haemophilus influenzae. The gene order in Buchnera is more similar to that of E. coli than to H. influenzae. The dramatic shrinkage of the Buchnera genome compared with those of other members of the closely related Enterobacteriaceae family is discussed in terms of evolution under the influence of the intracellular symbiotic association.}, }
@article {pmid9921679, year = {1998}, author = {Bandi, C and Anderson, TJ and Genchi, C and Blaxter, ML}, title = {Phylogeny of Wolbachia in filarial nematodes.}, journal = {Proceedings. Biological sciences}, volume = {265}, number = {1413}, pages = {2407-2413}, pmid = {9921679}, issn = {0962-8452}, mesh = {Animals ; Bacterial Proteins/classification/genetics ; Cattle ; *Cytoskeletal Proteins ; DNA, Bacterial ; DNA, Ribosomal/analysis ; Dogs ; Filarioidea/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S ; Rickettsiaceae/*classification/genetics ; }, abstract = {Intracellular bacteria have been observed in various species of filarial nematodes (family Onchocercidae). The intracellular bacterium of the canine filaria Dirofilaria immitis has been shown to be closely related to Wolbachia, a rickettsia-like micro-organism that is widespread among arthropods. However, the relationships between endosymbionts of different filariae, and between these and the arthropod wolbachiae, appear not to have been studied. To address these issues we have examined ten species of filarial nematodes for the presence of Wolbachia. For nine species, all samples examined were PCR positive using primers specific for the ftsZ gene of Wolbachia. For one species, the examined samples were PCR negative. Sequences of the amplified ftsZ gene fragments of filarial wolbachiae fall into two clusters (C and D), which are distinct from the A and B clusters recognized for arthropod wolbachiae. These four lineages (A-D) are related in a star-like phylogeny, with higher nucleotide divergence observed between C and D wolbachiae than that observed between A and B wolbachiae. In addition, within each of the two lineages of filarial wolbachiae, the phylogeny of the symbionts is consistent with the host phylogeny. Thus, there is no evidence for recent Wolbachia transmission between arthropods and nematodes. Endosymbiont 16S ribosomal DNA sequences from a subset of filarial species support these findings.}, }
@article {pmid9873083, year = {1999}, author = {Wastl, J and Fraunholz, M and Zauner, S and Douglas, S and Maier, UG}, title = {Ancient gene duplication and differential gene flow in plastid lineages: the GroEL/Cpn60 example.}, journal = {Journal of molecular evolution}, volume = {48}, number = {1}, pages = {112-117}, doi = {10.1007/pl00006438}, pmid = {9873083}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Chaperonin 60/*genetics ; Chloroplasts/genetics ; Eukaryota/classification/genetics ; Evolution, Molecular ; *Gene Duplication ; Genes, Plant/*genetics ; Molecular Sequence Data ; Phylogeny ; Plant Proteins/genetics ; Plastids/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {Cryptomonads, small biflagellate algae, contain four different genomes. In addition to the nucleus, mitochondrion, and chloroplast is a fourth DNA-containing organelle the nucleomorph. Nucleomorphs result from the successive reduction of the nucleus of an engulfed phototrophic eukaryotic endosymbiont by a secondary eukaryotic host cell. By sequencing the chloroplast genome and the nucleomorph chromosomes, we identified a groEL homologue in the genome of the chloroplast and a related cpn60 in one of the nucleomorph chromosomes. The nucleomorph-encoded Cpn60 and the chloroplast-encoded GroEL correspond in each case to one of the two divergent GroEL homologues in the cyanobacterium Synechocystis sp. PCC6803. The coexistence of divergent groEL/cpn60 genes in different genomes in one cell offers insights into gene transfer from evolving chloroplasts to cell nuclei and convergent gene evolution in chlorophyll a/b versus chlorophyll a/c/phycobilin eukaryotic lineages.}, }
@article {pmid9873079, year = {1999}, author = {Baumann, L and Baumann, P and Moran, NA and Sandström, J and Thao, ML}, title = {Genetic characterization of plasmids containing genes encoding enzymes of leucine biosynthesis in endosymbionts (Buchnera) of aphids.}, journal = {Journal of molecular evolution}, volume = {48}, number = {1}, pages = {77-85}, doi = {10.1007/pl00006447}, pmid = {9873079}, issn = {0022-2844}, mesh = {Animals ; Aphids/microbiology ; Bacteria/enzymology/*genetics ; Bacterial Proteins/genetics ; Base Composition ; Base Sequence ; Enzymes/*genetics ; Evolution, Molecular ; Gene Dosage ; *Genes, Bacterial ; Leucine/*biosynthesis/genetics ; Molecular Sequence Data ; Phylogeny ; Plasmids/*genetics ; Promoter Regions, Genetic/genetics ; Repetitive Sequences, Nucleic Acid/genetics ; Replication Origin/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {The prokaryotic endosymbionts (Buchnera) of aphids are known to provision their hosts with amino acids that are limiting in the aphid diet. Buchnera from the aphids Schizaphis graminum and Diuraphis noxia have plasmids containing leuABCD, genes that encode enzymes of the leucine biosynthetic pathway, as well as genes encoding proteins probably involved in plasmid replication (repA1 and repA2) and an open reading frame (ORF1) of unknown function. The newly reported plasmids closely resemble a plasmid previously described in Buchnera of the aphid Rhopalosiphum padi [Bracho AM, Martínez-Torres D, Moya A, Latorre A (1995) J Mol Evol 41:67-73]. Nucleotide sequence comparisons indicate conserved regions which may correspond to an origin of replication and two promoters, as well as inverted repeats, one of which resembles a rho-independent terminator. Phylogenetic analyses based on amino acid sequences of leu gene products and ORF1 resulted in trees identical to those obtained from endosymbiont chromosomal genes and the plasmid-borne trpEG. These results are consistent with a single evolutionary origin of the leuABCD-containing plasmid in a common ancestor of Aphididae and the lack of plasmid exchange between endosymbionts of different aphid species. Trees for ORF1 and repA (based on both nucleotides and amino acids) are used to examine the basis for leu plasmid differences between Buchnera of Thelaxes suberi and Aphididae. The most plausible explanation is that a single transfer of the leu genes to an ancestral replicon was followed by rearrangements. The related replicon in Buchnera of Pemphigidae, which lacks leuABCD, appears to represent the ancestral condition, implying that the plasmid location of the leu genes arose after the Pemphigidae diverged from other aphid families. This conclusion parallels previously published observations for the unrelated trpEG plasmid, which is present in Aphididae and absent in Pemphigidae. Recruitment of amino acid biosynthetic genes to plasmids has been ongoing in Buchnera lineages after the infection of aphid hosts.}, }
@article {pmid9873077, year = {1999}, author = {Durnford, DG and Deane, JA and Tan, S and McFadden, GI and Gantt, E and Green, BR}, title = {A phylogenetic assessment of the eukaryotic light-harvesting antenna proteins, with implications for plastid evolution.}, journal = {Journal of molecular evolution}, volume = {48}, number = {1}, pages = {59-68}, doi = {10.1007/pl00006445}, pmid = {9873077}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Carrier Proteins/chemistry/*genetics ; Chloroplasts/*genetics ; *Evolution, Molecular ; *Light-Harvesting Protein Complexes ; Molecular Sequence Data ; Multigene Family ; Photosynthetic Reaction Center Complex Proteins/*genetics ; Photosystem II Protein Complex ; *Phylogeny ; Plants/classification/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {The light-harvesting complexes (LHCs) are a superfamily of chlorophyll-binding proteins present in all photosynthetic eukaryotes. The Lhc genes are nuclear-encoded, yet the pigment-protein complexes are localized to the thylakoid membrane and provide a marker to follow the evolutionary paths of plastids with different pigmentation. The LHCs are divided into the chlorophyll a/b-binding proteins of the green algae, euglenoids, and higher plants and the chlorophyll a/c-binding proteins of various algal taxa. This work examines the phylogenetic position of the LHCs from three additional taxa: the rhodophytes, the cryptophytes, and the chlorarachniophytes. Phylogenetic analysis of the LHC sequences provides strong statistical support for the clustering of the rhodophyte and cryptomonad LHC sequences within the chlorophyll a/c-binding protein lineage, which includes the fucoxanthin-chlorophyll proteins (FCP) of the heterokonts and the intrinsic peridinin-chlorophyll proteins (iPCP) of the dinoflagellates. These associations suggest that plastids from the heterokonts, haptophytes, cryptomonads, and the dinoflagellate, Amphidinium, evolved from a red algal-like ancestor. The Chlorarachnion LHC is part of the chlorophyll a/b-binding protein assemblage, consistent with pigmentation, providing further evidence that its plastid evolved from a green algal secondary endosymbiosis. The Chlorarachnion LHC sequences cluster with the green algal LHCs that are predominantly associated with photosystem II (LHCII). This suggests that the green algal endosymbiont that evolved into the Chlorarachnion plastid was acquired following the emergence of distinct LHCI and LHCII complexes.}, }
@article {pmid9873076, year = {1999}, author = {Chen, X and Li, S and Aksoy, S}, title = {Concordant evolution of a symbiont with its host insect species: molecular phylogeny of genus Glossina and its bacteriome-associated endosymbiont, Wigglesworthia glossinidia.}, journal = {Journal of molecular evolution}, volume = {48}, number = {1}, pages = {49-58}, doi = {10.1007/pl00006444}, pmid = {9873076}, issn = {0022-2844}, support = {NIH-AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; DNA, Ribosomal/genetics ; Enterobacteriaceae/classification/*genetics ; *Evolution, Molecular ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis/*genetics ; Tsetse Flies/classification/*genetics ; }, abstract = {Many arthropods with restricted diets rely on symbiotic associations for full nutrition and fecundity. Tsetse flies (Diptera: Glossinidae) harbor three symbiotic organisms in addition to the parasitic African trypanosomes they transmit. Two of these microorganisms reside in different gut cells, while the third organism is harbored in reproductive tissues and belongs to the genus Wolbachia. The primary symbiont (genus Wigglesworthia glossinidia) lives in differentiated epithelial cells (bacteriocytes) which form an organ (bacteriome) in the anterior gut, while the secondary (S) symbionts are present in midgut cells. Here we have characterized the phylogeny of Wigglesworthia based on their 16S rDNA sequence analysis from eight species representing the three subgenera of Glossina: Austenina (=fusca group), Nemorhina (=palpalis group), and Glossina (=morsitans group). Independently, the ribosomal DNA internal transcribed spacer-2 (ITS-2) regions from these species were analyzed. The analysis of Wigglesworthia indicated that they form a distinct lineage in the gamma subdivision of Proteobacteria and display concordance with their host insect species. The trees generated by parsimony confirmed the monophyletic taxonomic placement of Glossina, where fusca group species formed the deepest branch followed by morsitans and palpalis groups, respectively. The placement of the species Glossina austeni by both the traditional morphological and biochemical criteria has been controversial. Results presented here, based on both the ITS-2 and the symbiont 16S rDNA sequence analysis, suggest that Glossina austeni should be placed into a separate fourth subgenus, Machadomyia, which forms a sister-group relationship with the morsitans group species.}, }
@article {pmid9872781, year = {1999}, author = {Fritsche, TR and Horn, M and Seyedirashti, S and Gautom, RK and Schleifer, KH and Wagner, M}, title = {In situ detection of novel bacterial endosymbionts of Acanthamoeba spp. phylogenetically related to members of the order Rickettsiales.}, journal = {Applied and environmental microbiology}, volume = {65}, number = {1}, pages = {206-212}, pmid = {9872781}, issn = {0099-2240}, support = {F06 TW002279/TW/FIC NIH HHS/United States ; F06 TW02279-01/TW/FIC NIH HHS/United States ; }, mesh = {Acanthamoeba/*microbiology/ultrastructure ; Alphaproteobacteria/classification/*genetics/*isolation &amp; purification ; Animals ; Base Sequence ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Genes, Bacterial ; In Situ Hybridization ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {Acanthamoebae are ubiquitous soil and water bactivores which may serve as amplification vehicles for a variety of pathogenic facultative bacteria and as hosts to other, presently uncultured bacterial endosymbionts. The spectrum of uncultured endosymbionts includes gram-negative rods and gram-variable cocci, the latter recently shown to be members of the Chlamydiales. We report here the isolation from corneal scrapings of two Acanthamoeba strains that harbor gram-negative rod endosymbionts that could not be cultured by standard techniques. These bacteria were phylogenetically characterized following amplification and sequencing of the near-full-length 16S rRNA gene. We used two fluorescently labelled oligonucleotide probes targeting signature regions within the retrieved sequences to detect these organisms in situ. Phylogenetic analyses demonstrated that they displayed 99.6% sequence similarity and formed an independent and well-separated lineage within the Rickettsiales branch of the alpha subdivision of the Proteobacteria. Nearest relatives included members of the genus Rickettsia, with sequence similarities of approximately 85 to 86%, suggesting that these symbionts are representatives of a new genus and, perhaps, family. Distance matrix, parsimony, and maximum-likelihood tree-generating methods all consistently supported deep branching of the 16S rDNA sequences within the Rickettsiales. The oligonucleotide probes displayed at least three mismatches to all other available 16S rDNA sequences, and they both readily permitted the unambiguous detection of rod-shaped bacteria within intact acanthamoebae by confocal laser-scanning microscopy. Considering the long-standing relationship of most Rickettsiales with arthropods, the finding of a related lineage of endosymbionts in protozoan hosts was unexpected and may have implications for the preadaptation and/or recruitment of rickettsia-like bacteria to metazoan hosts.}, }
@article {pmid9871114, year = {1999}, author = {Baumann, L and Baumann, P and Thao, ML}, title = {Detection of messenger RNA transcribed from genes encoding enzymes of amino acid biosynthesis in Buchnera aphidicola (endosymbiont of aphids).}, journal = {Current microbiology}, volume = {38}, number = {2}, pages = {135-136}, doi = {10.1007/s002849900417}, pmid = {9871114}, issn = {0343-8651}, mesh = {Amino Acids, Essential/biosynthesis ; Animals ; Aphids/*genetics ; Enzymes/genetics ; *Genes, Insect ; Molecular Sequence Data ; RNA, Messenger/*analysis ; Reverse Transcriptase Polymerase Chain Reaction/methods ; Symbiosis ; }, abstract = {The aphid Schizaphis graminum is dependent on Buchnera aphidicola, a prokaryotic endosymbiont. One of the functions of the endosymbiont is the synthesis of essential amino acids for the aphid host. Previously we have found that B. aphidicola has many of the genes that encode enzymes of amino acid biosynthesis. Using reverse transcriptase and the polymerase chain reaction, we have detected messenger RNA corresponding to genes involved in the synthesis of tryptophan, isoleucine, valine, leucine, and histidine.}, }
@article {pmid9864188, year = {1999}, author = {Graf, J}, title = {Symbiosis of Aeromonas veronii biovar sobria and Hirudo medicinalis, the medicinal leech: a novel model for digestive tract associations.}, journal = {Infection and immunity}, volume = {67}, number = {1}, pages = {1-7}, pmid = {9864188}, issn = {0019-9567}, mesh = {Aeromonas/chemistry/growth &amp; development/*isolation &amp; purification ; Animals ; Colony Count, Microbial ; DNA, Ribosomal/genetics/isolation &amp; purification ; Digestive System/*microbiology ; Feces/microbiology ; Humans ; Kinetics ; Leeches/*microbiology ; Molecular Sequence Data ; RNA, Ribosomal, 16S/genetics/isolation &amp; purification ; *Symbiosis ; }, abstract = {Hirudo medicinalis, the medicinal leech, is applied postoperatively in modern medicine. Infections by Aeromonas occur in up to 20% of patients unless a preemptive antibiotic treatment is administered. The associated infections demonstrate the need for a better understanding of the digestive tract flora of H. medicinalis. Early studies reported the presence of a single bacterial species in the digestive tract and suggested that these bacteria were endosymbionts contributing to the digestion of blood. In this study, we cultivated bacteria from the digestive tract and characterized them biochemically. The biochemical test results identified the isolates as Aeromonas veronii biovar sobria. This species identification was supported by sequence comparison of a variable region of the genes coding for 16S rRNA. In a colonization assay, a rifampin-resistant derivative of a symbiotic isolate was fed in a blood meal to H. medicinalis. The strain colonized the digestive tract rapidly and reached a concentration similar to that of the native bacterial flora. For the first 12 h, the in vivo doubling time was 1.2 h at 23 degreesC. After 12 h, at a density of 5 x 10(7) CFU/ml, the increase in viable counts ceased, suggesting a dramatic reduction in the bacterial growth rate. Two human fecal isolates, identified as Aeromonas hydrophila and A. veronii biovar sobria, were also able to colonize the digestive tract. These data demonstrate that the main culturable bacterium in the crop of H. medicinalis is A. veronii biovar sobria and that the medicinal leech can be used as a model for digestive tract association of Aeromonas species.}, }
@article {pmid9862473, year = {1998}, author = {Fraunholz, MJ and Moerschel, E and Maier, UG}, title = {The chloroplast division protein FtsZ is encoded by a nucleomorph gene in cryptomonads.}, journal = {Molecular &amp; general genetics : MGG}, volume = {260}, number = {2-3}, pages = {207-211}, doi = {10.1007/s004380050887}, pmid = {9862473}, issn = {0026-8925}, mesh = {Amino Acid Sequence ; Arabidopsis Proteins ; Bacterial Proteins/*genetics/metabolism ; Chloroplasts/*genetics ; Eukaryota/*genetics ; Gene Expression Regulation ; Molecular Sequence Data ; Open Reading Frames ; *Phylogeny ; *Plant Proteins ; Sequence Homology, Amino Acid ; Subcellular Fractions ; }, abstract = {Guillardia theta is a cryptomonad alga, whose phototrophic symbiont was acquired by secondary endocytobiosis. The nucleomorph, the vestigial nucleus of the eukaryotic endosymbiont, harbors three linear chromosomes with a total coding capacity of 515 kb. Sequencing of the nucleomorph genome reveals that it encodes an ORF homologous to the bacterial cell division protein FtsZ, supporting the hypothesis that FtsZ is common in chloroplasts. We show that the nucleomorph-encoded ftsZ gene is transcribed. The transcript is polyadenylated and therefore shows features typical of eukaryotic transcripts. However, 3' processing of nucleomorph mRNA is inaccurate. Transcripts of nucleomorph genes in G. theta overlap with neighboring UTRs and coding regions. We demonstrate that the reading frame encoding NmFtsZ is not interrupted by introns. Subcellular localization of the protein reveals that FtsZ is localized exclusively in the chloroplast of G. theta, demonstrating that FtsZ is imported into the organelle.}, }
@article {pmid9851608, year = {1998}, author = {Henkle-Dührsen, K and Eckelt, VH and Wildenburg, G and Blaxter, M and Walter, RD}, title = {Gene structure, activity and localization of a catalase from intracellular bacteria in Onchocerca volvulus.}, journal = {Molecular and biochemical parasitology}, volume = {96}, number = {1-2}, pages = {69-81}, doi = {10.1016/s0166-6851(98)00109-1}, pmid = {9851608}, issn = {0166-6851}, mesh = {Amino Acid Sequence ; Animals ; Catalase/analysis/chemistry/*genetics/metabolism ; Female ; *Genes, Bacterial ; Genes, rRNA ; Immunoenzyme Techniques ; Male ; Microfilariae/enzymology/microbiology ; Microscopy, Electron ; Molecular Sequence Data ; Onchocerca volvulus/enzymology/growth &amp; development/*microbiology/ultrastructure ; Open Reading Frames ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Recombinant Proteins/chemistry/metabolism ; Rickettsiaceae/enzymology/*genetics/ultrastructure ; Sequence Alignment ; }, abstract = {Within the context of studies on the antioxidant enzymes in Onchocerca volvulus, DNA clones encoding catalase (CAT) were isolated from an O. volvulus adult lambda zapII cDNA library. Analysis of their nucleotide and encoded amino acid sequences revealed that they derive from intracellular bacteria, rather than the O. volvulus nuclear genome. The endobacterial CAT gene was found to lie in a gene cluster, followed by a ferritin gene and an excinuclease gene. The endobacterial CAT gene encodes a functional enzyme capable of detoxifying H2O2, demonstrated by producing an active recombinant protein in an E. coli expression system. The purified 54 kDa protein has CAT activity over a broad pH range, with a specific activity of 103,000 +/- 3000 U mg(-1). The optical spectrum of the endobacterial CAT shows that it is a ferric haem-containing protein with a Soret band at 405 nm. To investigate the phylogeny of the intracellular bacterium in O. volvulus, a segment of the 16S rRNA gene was amplified from total genomic DNA by a polymerase chain reaction using universal eubacterial primers. A phylogenetic analysis of the O. volvulus-derived 16S rRNA sequence revealed that the endobacterium belongs to a distinct Wolbachia clade of the order Rickettsiales. Onchocercomata and biopsies containing different onchocercal species were immunohistochemically stained using polyclonal antibodies raised against the recombinant endobacterial CAT. CAT was detected in the endobacteria in the hypodermis of adult male and female O. volvulus, O. ochengi, O. gibsoni and O. fasciata. The endobacterial enzyme was also detected in onchocercal oocytes and all embryonic stages including intrauterine microfilariae as well as skin microfilariae. O. volvulus thus harbours Wolbachia-like endosymbionts which are transovarially transmitted and show particular affinity for the hypodermal tissues of the lateral chords.}, }
@article {pmid9812361, year = {1998}, author = {Silva, FJ and van Ham, RC and Sabater, B and Latorre, A}, title = {Structure and evolution of the leucine plasmids carried by the endosymbiont (Buchnera aphidicola) from aphids of the family Aphididae.}, journal = {FEMS microbiology letters}, volume = {168}, number = {1}, pages = {43-49}, doi = {10.1111/j.1574-6968.1998.tb13253.x}, pmid = {9812361}, issn = {0378-1097}, mesh = {Amino Acid Sequence ; Animals ; Aphids/classification/*microbiology ; Base Sequence ; Chromosome Mapping ; Enterobacteriaceae/classification/*genetics/isolation &amp; purification ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Leucine/*biosynthesis/genetics ; Molecular Sequence Data ; Nucleic Acid Conformation ; Open Reading Frames ; Phylogeny ; Plasmids/*genetics ; RNA, Bacterial/chemistry/genetics ; RNA, Messenger/chemistry/genetics ; Repetitive Sequences, Nucleic Acid ; Sequence Alignment ; Symbiosis ; }, abstract = {In all examined species of the family Aphididae, the bacterial endosymbiont Buchnera aphidicola carries a plasmid encoding the genes leuABCD (involved in leucine biosynthesis) along with repA1, repA2 and ORF1. The gene organisation of the leucine plasmids was conserved, except in Buchnera isolated from Pterocomma populeum, where ORF1 was located in a different position. An inverted repeat (LIR1) located between repA2 and leuA is found in all of the Buchnera leucine plasmids examined. The predicted secondary structure of the LIR1 transcript conforms to a long hairpin loop, suggesting an involvement in transcription termination or messenger stability. Phylogenetic reconstruction based on repA2 sequences suggests that horizontal transfer of Buchnera leucine plasmids has not occurred.}, }
@article {pmid9783459, year = {1998}, author = {Keeling, PJ and Deane, JA and McFadden, GI}, title = {The phylogenetic position of alpha- and beta-tubulins from the Chlorarachnion host and Cercomonas (Cercozoa).}, journal = {The Journal of eukaryotic microbiology}, volume = {45}, number = {5}, pages = {561-570}, doi = {10.1111/j.1550-7408.1998.tb05117.x}, pmid = {9783459}, issn = {1066-5234}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; DNA Primers ; Eukaryota/*classification/*genetics ; *Evolution, Molecular ; Fungi/classification ; Gene Library ; Humans ; Microsporida/classification ; Molecular Sequence Data ; *Phylogeny ; Plants/classification ; Polymerase Chain Reaction ; Tubulin/*genetics ; }, abstract = {Alpha and beta-tubulin genes from Chlorarachnion and an alpha-tubulin gene from Cercomonas have been characterised. We found the Cercomonas and Chlorarachnion alpha tubulins to be closely related to one another, confirming the proposed relationship of these genera. In addition, the Chlorarachnion host and Cercomonas also appear to be more distantly related to Heterolobosea, Euglenozoa, chlorophytes, heterokonts, and alveolates. Chlorarachnion was also found to have two distinctly different types of both alpha- and beta-tubulin, one type being highly-divergent. Chlorarachnion contains a secondary endosymbiont of green algal origin, raising the possibility that one type of Chlorarachnion tubulins comes from the host and the other from the endosymbiont. Probing pulsed field-separated chromosomes showed that the highly-divergent genes are encoded by the host genome, and neither alpha- nor beta-tubulin cDNAs were found to include 5' extensions that might serve as targeting peptides. It appears that Chlorarachnion has distinct and divergent tubulin paralogues that are all derived from the host lineage. One Chlorarachnion beta-tubulin was also found to be a pseudogene, which is still expressed but aberrantly processed. Numerous unspliced introns and deletions resulting from mis-splicing are contained in the mRNAs from this gene.}, }
@article {pmid9770279, year = {1998}, author = {Fritsche, TR and Sobek, D and Gautom, RK}, title = {Enhancement of in vitro cytopathogenicity by Acanthamoeba spp. following acquisition of bacterial endosymbionts.}, journal = {FEMS microbiology letters}, volume = {166}, number = {2}, pages = {231-236}, doi = {10.1111/j.1574-6968.1998.tb13895.x}, pmid = {9770279}, issn = {0378-1097}, support = {F06 TW02279-01/TW/FIC NIH HHS/United States ; }, mesh = {Acanthamoeba/growth &amp; development/isolation &amp; purification/*microbiology/*pathogenicity ; Animals ; Cell Line ; Culture Media, Conditioned ; Fibroblasts ; Gram-Negative Bacteria/*physiology ; Humans ; *Symbiosis ; Virulence ; }, abstract = {Approximately one in five isolates of Acanthamoeba spp. recovered from clinical and environmental sources are found to harbor obligate, uncultured bacterial endosymbionts of unknown clinical significance. To investigate their possible role in amoebic pathogenesis, four uninfected amoebic strains were exposed to four different endosymbionts, from which 12 stably-infected host-symbiont pairs resulted. Standardized inocula of amoebae with and without endosymbionts were placed on fibroblast monolayers to examine for cytopathic effects (CPEs). Eight to 10 days were required for monolayer effacement by endosymbiont-free amoebae; 5-8 days for amoebae containing Gram-negative rod endosymbionts; and 3 days for two amoebic isolates infected with a Chlamydia-like endosymbiont. All endosymbiont-infected amoebae produced a statistically significant enhancement in CPEs in comparison to uninfected amoebae; endosymbionts alone on monolayers produced no CPEs. This report provides evidence that obligate bacterial endosymbionts are able to enhance amoebic pathogenic potential in vitro by some as-yet unknown mechanism.}, }
@article {pmid9767718, year = {1998}, author = {Clark, MA and Baumann, L and Baumann, P}, title = {Buchnera aphidicola (Aphid endosymbiont) contains genes encoding enzymes of histidine biosynthesis.}, journal = {Current microbiology}, volume = {37}, number = {5}, pages = {356-358}, doi = {10.1007/s002849900392}, pmid = {9767718}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*enzymology/*genetics ; Chromosome Mapping ; Cloning, Molecular ; Codon ; DNA, Bacterial/analysis ; *Genes, Bacterial ; Histidine/*biosynthesis ; Molecular Sequence Data ; Sequence Analysis, DNA ; }, abstract = {Buchnera aphidicola is an endosymbiont of aphids. One of its functions appears to be the synthesis of essential amino acids for the aphid host. A 12.8-kilobase B. aphidicola DNA fragment has been cloned and sequenced. It contains genes encoding all of the enzymes required for the biosynthesis of the essential amino acid histidine. The order of the genes, hisGDCBHAFI, is the same as that found in Escherichia coli and is consistent with their constituting a single transcription unit. The DNA fragment also contained genes involved in aromatic amino acid biosynthesis (aroC), the oxidative pentose pathway (gnd), and 2'-deoxyribonucleotide metabolism (dcd), as well as a tRNA synthase (metG).}, }
@article {pmid9758773, year = {1998}, author = {Fukatsu, T and Nikoh, N}, title = {Two intracellular symbiotic bacteria from the mulberry psyllid Anomoneura mori (Insecta, Homoptera).}, journal = {Applied and environmental microbiology}, volume = {64}, number = {10}, pages = {3599-3606}, pmid = {9758773}, issn = {0099-2240}, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; DNA, Bacterial/chemistry/*genetics ; DNA, Ribosomal/chemistry/*genetics ; Fruit ; Gram-Negative Bacteria/classification/*genetics ; Insecta/*microbiology ; Molecular Sequence Data ; *Phylogeny ; *Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/*genetics ; Sequence Alignment ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {We characterized the intracellular symbiotic bacteria of the mulberry psyllid Anomoneura mori by performing a molecular phylogenetic analysis combined with in situ hybridization. In its abdomen, the psyllid has a large, yellow, bilobed mycetome (or bacteriome) which consists of many round uninucleated mycetocytes (or bacteriocytes) enclosing syncytial tissue. The mycetocytes and syncytium harbor specific intracellular bacteria, the X-symbionts and Y-symbionts, respectively. Almost the entire length of the bacterial 16S ribosomal DNA (rDNA) was amplified and cloned from the whole DNA of A. mori, and two clones, the A-type and B-type clones, were identified by restriction fragment length polymorphism analysis. In situ hybridization with specific oligonucleotide probes demonstrated that the A-type and B-type 16S rDNAs were derived from the X-symbionts and Y-symbionts, respectively. Molecular phylogenetic analyses of the 16S rDNA sequences showed that these symbionts belong to distinct lineages in the gamma subdivision of the Proteobacteria. No 16S rDNA sequences in the databases were closely related to the 16S rDNA sequences of the X- and Y-symbionts. However, the sequences that were relatively closely related to them were the sequences of endosymbionts of other insects. The nucleotide compositions of the 16S rDNAs of the X- and Y-symbionts were highly AT biased, and the sequence of the X-symbiont was the most AT-rich bacterial 16S rDNA sequence reported so far.}, }
@article {pmid9736608, year = {1998}, author = {Meurer, J and Plücken, H and Kowallik, KV and Westhoff, P}, title = {A nuclear-encoded protein of prokaryotic origin is essential for the stability of photosystem II in Arabidopsis thaliana.}, journal = {The EMBO journal}, volume = {17}, number = {18}, pages = {5286-5297}, pmid = {9736608}, issn = {0261-4189}, mesh = {Amino Acid Sequence ; Arabidopsis/genetics/*metabolism ; *Arabidopsis Proteins ; Chlorophyll/analysis ; Chloroplasts/metabolism/ultrastructure ; Cloning, Molecular ; Cyanobacteria/*genetics ; Evolution, Molecular ; Genes, Plant/genetics ; Genetic Complementation Test ; Light-Harvesting Protein Complexes ; Membrane Proteins/biosynthesis/genetics/*physiology ; Molecular Sequence Data ; Mutation ; Nuclear Proteins/biosynthesis/genetics/*physiology ; Photosynthetic Reaction Center Complex Proteins/*metabolism ; Photosystem II Protein Complex ; RNA, Messenger/analysis ; RNA, Plant/analysis ; Sequence Homology, Amino Acid ; }, abstract = {To understand the regulatory mechanisms underlying the biogenesis of photosystem II (PSII) we have characterized the nuclear mutant hcf136 of Arabidopsis thaliana and isolated the affected gene. The mutant is devoid of any photosystem II activity, and none of the nuclear- and plastome-encoded subunits of this photosystem accumulate to significant levels. Protein labelling studies in the presence of cycloheximide showed that the plastome-encoded PSII subunits are synthesized but are not stable. The HCF136 gene was isolated by virtue of its T-DNA tag, and its identity was confirmed by complementation of homozygous hcf136 seedlings. Immunoblot analysis of fractionated chloroplasts showed that the HCF136 protein is a lumenal protein, found only in stromal thylakoid lamellae. The HCF136 protein is produced already in dark-grown seedlings and its levels do not increase dramatically during light-induced greening. This accumulation profile confirms the mutational data by showing that the HCF136 protein must be present when PSII complexes are made. HCF136 homologues are found in the cyanobacterium Synechocystis species PCC6803 (slr2034) and the cyanelle genome of Cyanophora paradoxa (ORF333), but are lacking in the plastomes of chlorophytes and metaphytes as well as from those of rhodo- and chromophytes. We conclude that HCF136 encodes a stability and/or assembly factor of PSII which dates back to the cyanobacterial-like endosymbiont that led to the plastids of the present photosynthetic eukaryotes.}, }
@article {pmid9717755, year = {1998}, author = {Murdoch, D and Gray, TB and Cursons, R and Parr, D}, title = {Acanthamoeba keratitis in New Zealand, including two cases with in vivo resistance to polyhexamethylene biguanide.}, journal = {Australian and New Zealand journal of ophthalmology}, volume = {26}, number = {3}, pages = {231-236}, doi = {10.1111/j.1442-9071.1998.tb01317.x}, pmid = {9717755}, issn = {0814-9763}, mesh = {Acanthamoeba/isolation &amp; purification ; Acanthamoeba Keratitis/diagnosis/drug therapy/epidemiology/*etiology ; Adult ; Animals ; Biguanides/*therapeutic use ; Contact Lens Solutions/*therapeutic use ; Contact Lenses, Hydrophilic/*adverse effects ; Cornea/parasitology ; Drug Resistance ; Female ; Humans ; Male ; Middle Aged ; New Zealand/epidemiology ; Treatment Outcome ; }, abstract = {BACKGROUND: Acanthamoeba keratitis is an uncommon corneal infection that can run a protracted course with, at times, serious visual results. Eighty-five per cent of cases occur in soft contact lens wearers. The first New Zealand case occurred in 1990 and only seven cases have been identified in New Zealand to the end of 1996.<br><br>METHODS: We surveyed the ophthalmologists looking after these seven cases of acanthamoeba keratitis as to time to diagnosis, treatment and outcome.<br><br>RESULTS: New Zealand has a low incidence of this disease. All cases were soft contact lens wearers with defective care in every instance. After an initial two late-diagnosed cases, the time to diagnosis for four of the five other cases has been within 2 weeks. Medical treatment has varied over this series, but since the introduction of the cationic antiseptics polyhexamethylene biguanide (PHMB) and chlorhexidine in 1992, the last five cases were all treated with PHMB. One case diagnosed within 2 weeks ran a devastating course, despite intensive PHMB, and a second case remained culture positive after 1 year of PHMB and the late addition of chlorhexidine. Debridement, 0.1% PHMB and hexamidine eventually settled this eye.<br><br>CONCLUSIONS: For treatment PHMB, hexamidine rather than propamidine and surgical debridement are favoured. While all Acanthamoeba isolates show good in vitro sensitivity to PHMB, the in vivo response is not always proportionate. A bacterial endosymbiont may have been a factor in the favourable outcome of one protracted case.}, }
@article {pmid9707583, year = {1998}, author = {Peek, AS and Feldman, RA and Lutz, RA and Vrijenhoek, RC}, title = {Cospeciation of chemoautotrophic bacteria and deep sea clams.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {95}, number = {17}, pages = {9962-9966}, pmid = {9707583}, issn = {0027-8424}, support = {TW00735-01/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; Bacteria/classification/*genetics ; Bivalvia/classification/*genetics/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Likelihood Functions ; Models, Genetic ; Ovum/microbiology ; Phylogeny ; Species Specificity ; *Symbiosis ; }, abstract = {Vesicomyid clams depend entirely on sulfur-oxidizing endosymbiotic bacteria for their nutriment. Endosymbionts that are transmitted cytoplasmically through eggs, such as these, should exhibit a phylogenetic pattern that closely parallels the phylogeny of host mitochondrial genes. Such parallel patterns are rarely observed, however, because they are obscured easily by small amounts of horizontal symbiont transmission or occasional host switching. The present symbiont genealogy, based on bacterial small subunit (16S) rDNA sequences, was closely congruent with the host genealogy, based on clam mitochondrial cytochrome oxidase subunit I and large subunit (16S) rDNA sequences. This phylogenetic evidence supports the hypothesis of cospeciation and a long term association between the participants in this symbiosis.}, }
@article {pmid9701808, year = {1998}, author = {Sola-Landa, A and Pizarro-Cerdá, J and Grilló, MJ and Moreno, E and Moriyón, I and Blasco, JM and Gorvel, JP and López-Goñi, I}, title = {A two-component regulatory system playing a critical role in plant pathogens and endosymbionts is present in Brucella abortus and controls cell invasion and virulence.}, journal = {Molecular microbiology}, volume = {29}, number = {1}, pages = {125-138}, doi = {10.1046/j.1365-2958.1998.00913.x}, pmid = {9701808}, issn = {0950-382X}, mesh = {Animals ; Base Sequence ; Brucella abortus/*genetics/*pathogenicity ; Cells, Cultured ; Cloning, Molecular ; DNA, Bacterial ; HeLa Cells ; Humans ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Plants/microbiology ; Symbiosis ; Virulence ; }, abstract = {Two mutants showing increased sensitivity to polycations and surfactants were obtained by transposon mutagenesis of virulent Brucella abortus 2308 Nalr. These mutants showed no obvious in vitro growth defects and produced smooth-type lipopolysaccharides. However, they hardly multiplied or persisted in mouse spleens, displayed reduced invasiveness in macrophages and HeLa cells, lost the ability to inhibit lysosome fusion and were unable to replicate intracellularly. Subsequent DNA analyses identified a two-component regulatory system [Brucella virulence related (Bvr)] with a regulatory (BvrR) and sensory (BvrS) protein. Cloning of bvrR in the BvrR-deficient mutant restored the resistance to polycations and, in part, the invasiveness and the ability to multiply intracellularly. BvrR and BvrS were highly similar (87-89% and 70-80% respectively) to the regulatory and sensory proteins of the chromosomally encoded Rhizobium meliloti Chvl-ExoS and Agrobacterium tumefaciens Chvl-ChvG systems previously shown to be critical for endosymbiosis and pathogenicity in plants. Divergence among the three sensory proteins was located mostly within a periplasmic domain probably involved in stimulus sensing. As B. abortus, R. meliloti and A. tumefaciens are phylogenetically related, these observations suggest that these systems have a common ancestor that has evolved to sense stimuli in plant and animal microbial environments.}, }
@article {pmid9688822, year = {1998}, author = {Thao, ML and Baumann, P}, title = {Sequence analysis of a DNA fragment from buchnera aphidicola (Aphid endosymbiont) containing the genes dapD-htrA-ilvI-ilvH-ftsL-ftsI-murE.}, journal = {Current microbiology}, volume = {37}, number = {3}, pages = {214-216}, doi = {10.1007/s002849900365}, pmid = {9688822}, issn = {1432-0991}, abstract = {Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. One of the endosymbiont's functions is the synthesis of branched-chain amino acids. A 9.7-kilobase B. aphidicola chromosomal DNA fragment was cloned and sequenced and found to contain genes encoding acetohydroxy acid synthase (ilvIH), the first enzyme of the parallel pathway of isoleucine and valine biosynthesis. Previously we have detected ilvC and ilvD, encoding the two other enzymes of this pathway. In addition the DNA fragment contained genes for cell division (ftsL, ftsI), murein biosynthesis (murE), lysine biosynthesis (dapD) and a periplasmic protease (htrA). In these properties B. aphidicola resembles free-living bacteria.}, }
@article {pmid9625791, year = {1998}, author = {Baumann, L and Baumann, P and Moran, NA}, title = {The endosymbiont (Buchnera) of the aphid Diuraphis noxia contains all the genes of the tryptophan biosynthetic pathway.}, journal = {Current microbiology}, volume = {37}, number = {1}, pages = {58-59}, doi = {10.1007/s002849900337}, pmid = {9625791}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*genetics/metabolism ; Base Sequence ; *Genes, Bacterial ; Molecular Sequence Data ; Open Reading Frames ; Tryptophan/*genetics/metabolism ; }, abstract = {Previously it has been shown that the prokaryotic endosymbiont (Buchnera) of the aphid Diuraphis noxia contains a plasmid consisting of one copy of the gene for anthranilate synthase (trpEG) and seven trpEG pseudogenes. In the present communication we show that this endosymbiont contains the remaining genes of the tryptophan biosynthetic pathway [trpDC(F)BA] which appear to be functional in that they code for the complete enzyme proteins and are not pseudogenes. As in the case of Buchnera from other endosymbionts, these genes appear to be organized as one transcription unit and are located on the endosymbiont chromosome.}, }
@article {pmid9582417, year = {1998}, author = {Flowers, AE and Garson, MJ and Webb, RI and Dumdei, EJ and Charan, RD}, title = {Cellular origin of chlorinated diketopiperazines in the dictyoceratid sponge Dysidea herbacea (Keller).}, journal = {Cell and tissue research}, volume = {292}, number = {3}, pages = {597-607}, doi = {10.1007/s004410051089}, pmid = {9582417}, issn = {0302-766X}, mesh = {Animals ; Cell Fractionation ; Cell Separation ; Colloids ; Cyanobacteria/*chemistry/metabolism/ultrastructure ; Hydrocarbons, Chlorinated/*analysis ; Microscopy, Electron ; Piperazines/*analysis ; Porifera/*microbiology ; Povidone ; Silicon Dioxide ; Terpenes/analysis ; Vacuoles/ultrastructure ; }, abstract = {The tropical marine sponge Dysidea herbacea (Keller) contains the filamentous unicellular cyanobacterium Oscillatoria spongeliae (Schulze) Hauck as an endosymbiont, plus numerous bacteria, both intracellular and extracellular. Archaeocytes and choanocytes are the major sponge cell types present. Density gradient centrifugation of glutaraldehyde-fixed cells with Percoll as the support medium has been used to separate the cyanobacterial symbiont from the sponge cells on the basis of their differing densities. The protocol also has the advantage of separating broken from intact cells of O. spongeliae. The lighter cell preparations contain archaeocytes and choanocytes together with damaged cyanobacterial cells, whereas heavier cell preparations contain intact cyanobacterial cells, with less than 1% contamination by sponge cells. Gas chromatography/mass spectrometry analysis has revealed that the terpene spirodysin is concentrated in preparations containing archaeocytes and choanocytes, whereas nuclear magnetic resonance analysis of the symbiont cell preparations has shown that they usually contain the chlorinated diketopiperazines, dihydrodysamide C and didechlorodihydrodysamide C, which are the characteristic metabolites of the sponge/symbiont association. However, one symbiont preparation, partitioned by a second Percoll gradient, has been found to be devoid of chlorinated diketopiperazines. The capability to synthesize secondary metabolites may depend on the physiological state of the symbiont; alternatively, there may be two closely related cyanobacterial strains within the sponge tissue.}, }
@article {pmid9627990, year = {1998}, author = {Hollar, L and Lukes, J and Maslov, DA}, title = {Monophyly of endosymbiont containing trypanosomatids: phylogeny versus taxonomy.}, journal = {The Journal of eukaryotic microbiology}, volume = {45}, number = {3}, pages = {293-297}, doi = {10.1111/j.1550-7408.1998.tb04539.x}, pmid = {9627990}, issn = {1066-5234}, mesh = {Animals ; Bacteria ; Crithidia/*classification/genetics/microbiology ; DNA Restriction Enzymes ; DNA, Kinetoplast/*genetics ; Genes, Protozoan ; *Phylogeny ; RNA, Protozoan/genetics ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; Symbiosis ; Trypanosomatina/*classification/genetics/microbiology ; }, abstract = {To obtain additional information on the phylogenetic relationships within the family Trypanosomatidae (order Kinetoplastida), we have sequenced the small subunit ribosomal RNA genes from the endosymbiont containing species Herpetomonas roitmani TCC080, Herpetomonas sp. TCC263, Crithidia oncopelti ATCC 12982 and a partial large subunit rRNA gene from H. roitmani. The small subunit sequences in the two isolates of Herpetomonas are very similar but not identical, and so are their restriction digest profiles of kinetoplast DNA. The size of minicircles in both isolates is 4.2 kilobases. The inferred ribosomal RNA phylogenetic trees shows the genera Herpetomonas and Crithidia as polyphyletic. Endosymbiont-bearing herpetomonads cluster with the endosymbiont-bearing crithidias and a blastocrithidia to form a monophyletic clade, whereas the endosymbiont-free members of these genera are found elsewhere in the tree. These data support the hypothesis of a monophyletic origin of endosymbiosis in trypanosomatid evolution and also suggest that a taxonomic revision is needed in order to better describe the natural affinities in this family.}, }
@article {pmid9604312, year = {1998}, author = {Feldman, RA and Shank, TM and Black, MB and Baco, AR and Smith, CR and Vrijenhoek, RC}, title = {Vestimentiferan on a whale fall.}, journal = {The Biological bulletin}, volume = {194}, number = {2}, pages = {116-119}, doi = {10.2307/1543041}, pmid = {9604312}, issn = {0006-3185}, support = {PHSTW00735-01/PH/PHPPO CDC HHS/United States ; }, mesh = {Animals ; Annelida/*classification/genetics ; Bone and Bones/*parasitology ; California ; DNA, Mitochondrial/chemistry/*isolation &amp; purification ; Electron Transport Complex IV/*genetics ; Gene Amplification ; Polymerase Chain Reaction ; Skull ; Whales/*parasitology ; }, abstract = {Discovery of chemosynthetic communities associated with whale bones led to the hypothesis that whale falls may serve as stepping-stones for faunal dispersal between disjunct hydrothermal vents and cold seeps on the ocean floor (1). The initial observation was followed by a faunal inventory that revealed a diverse assemblage of microbes and invertebrates, supported by chemoautotrophic production, living in close proximity to whale remains (2, 3). To date, the conspicuous absence from whale falls of vestimentiferan tubeworms (a predominant constituent of eastern Pacific vent and seep habitats) has been a major objection to the stepping-stone hypothesis (4-5). We report the first evidence of a vestimentiferan tubeworm associated with a whale fall (Fig. 1). The tubeworm, Escarpia spicata, was identified by morphological criteria and DNA sequence data from a portion of the mitochondrial cytochrome oxidase C subunit I (COI) gene. Additionally, the bacterial endosymbiont in the tubeworm possessed a 16S rRNA gene that was similar to that of endosymbionts from vestimentiferans in sedimented cold-seep environments.}, }
@article {pmid9539759, year = {1998}, author = {Lambert, JD and Moran, NA}, title = {Deleterious mutations destabilize ribosomal RNA in endosymbiotic bacteria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {95}, number = {8}, pages = {4458-4462}, pmid = {9539759}, issn = {0027-8424}, mesh = {Animals ; Ants/microbiology ; Aphids/microbiology ; Bacteria/*genetics ; Bacterial Physiological Phenomena ; Base Composition ; *Biological Evolution ; Coleoptera/microbiology ; Diptera/microbiology ; Escherichia coli/genetics/physiology ; Genetic Variation ; *Mutation ; Nucleic Acid Conformation ; Phylogeny ; RNA, Ribosomal, 16S/chemistry/*genetics ; Selection, Genetic ; *Symbiosis ; }, abstract = {In populations that are small and asexual, mutations with slight negative effects on fitness will drift to fixation more often than in large or sexual populations in which they will be eliminated by selection. If such mutations occur in substantial numbers, the combined effects of long-term asexuality and small population size may result in substantial accumulation of mildly deleterious substitutions. Prokaryotic endosymbionts of animals that are transmitted maternally for very long periods are effectively asexual and experience smaller effective population size than their free-living relatives. The contrast between such endosymbionts and related free-living bacteria allows us to test whether a population structure imposing frequent bottlenecks and asexuality does lead to an accumulation of slightly deleterious substitutions. Here we show that several independently derived insect endosymbionts, each with a long history of maternal transmission, have accumulated destabilizing base substitutions in the highly conserved 16S rRNA. Stabilities of Domain I of this subunit are 15-25% lower in endosymbionts than in closely related free-living bacteria. By mapping destabilizing substitutions onto a reconstructed phylogeny, we show that decreased ribosomal stability has evolved separately in each endosymbiont lineage. Our phylogenetic approach allows us to demonstrate statistical significance for this pattern: becoming endosymbiotic predictably results in decreased stability of rRNA secondary structure.}, }
@article {pmid9580987, year = {1998}, author = {Brynnel, EU and Kurland, CG and Moran, NA and Andersson, SG}, title = {Evolutionary rates for tuf genes in endosymbionts of aphids.}, journal = {Molecular biology and evolution}, volume = {15}, number = {5}, pages = {574-582}, doi = {10.1093/oxfordjournals.molbev.a025958}, pmid = {9580987}, issn = {0737-4038}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Bacteria/*genetics ; Codon ; Escherichia coli/genetics ; *Evolution, Molecular ; Models, Biological ; Molecular Sequence Data ; Mutation ; Peptide Elongation Factor Tu/*genetics ; Phylogeny ; RNA, Ribosomal, 16S ; Recombination, Genetic ; Salmonella typhimurium/genetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {The gene encoding elongation factor Tu (tuf) in aphid endosymbionts (genus Buchnera) evolves at rates of 1.3 x 10(-10) to 2.5 x 10(-10) nonsynonymous substitutions and 3.9 x 10(-9) to 8.0 x 10(-9) synonymous substitutions per position per year. These rates, which are at present among the most reliable substitution rates for protein-coding genes of bacteria, have been obtained by calibrating the nodes in the phylogenetic tree produced from the Buchnera EF-Tu sequences using divergence times for the corresponding ancestral aphid hosts. We also present data suggesting that the rates of nonsynonymous substitutions are significantly higher in the endosymbiont lineages than in the closely related free-living bacteria Escherichia coli and Salmonella typhimurium. Synonymous substitution rates for Buchnera approximate estimated mutation rates for E. coli and S. typhimurium, as expected if synonymous changes act as neutral mutations in Buchnera. We relate the observed differences in substitution frequencies to the absence of selective codon preferences in Buchnera and to the influence of Muller's ratchet on small asexual populations.}, }
@article {pmid9573188, year = {1998}, author = {Braig, HR and Zhou, W and Dobson, SL and O'Neill, SL}, title = {Cloning and characterization of a gene encoding the major surface protein of the bacterial endosymbiont Wolbachia pipientis.}, journal = {Journal of bacteriology}, volume = {180}, number = {9}, pages = {2373-2378}, pmid = {9573188}, issn = {0021-9193}, support = {T32 AI007404/AI/NIAID NIH HHS/United States ; AI 07404/AI/NIAID NIH HHS/United States ; AI 34355/AI/NIAID NIH HHS/United States ; AI40620/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Bacterial Outer Membrane Proteins/*genetics ; Base Sequence ; Cloning, Molecular ; Drosophila/*microbiology ; Escherichia coli/genetics ; *Genes, Bacterial ; Molecular Sequence Data ; Moths/microbiology ; Promoter Regions, Genetic ; Recombinant Proteins ; Rickettsiaceae/*genetics ; Sequence Homology, Amino Acid ; Symbiosis/*genetics ; }, abstract = {The maternally inherited intracellular symbiont Wolbachia pipientis is well known for inducing a variety of reproductive abnormalities in the diverse arthropod hosts it infects. It has been implicated in causing cytoplasmic incompatibility, parthenogenesis, and the feminization of genetic males in different hosts. The molecular mechanisms by which this fastidious intracellular bacterium causes these reproductive and developmental abnormalities have not yet been determined. In this paper, we report on (i) the purification of one of the most abundantly expressed Wolbachia proteins from infected Drosophila eggs and (ii) the subsequent cloning and characterization of the gene (wsp) that encodes it. The functionality of the wsp promoter region was also successfully tested in Escherichia coli. Comparison of sequences of this gene from different strains of Wolbachia revealed a high level of variability. This sequence variation correlated with the ability of certain Wolbachia strains to induce or rescue the cytoplasmic incompatibility phenotype in infected insects. As such, this gene will be a very useful tool for Wolbachia strain typing and phylogenetic analysis, as well as understanding the molecular basis of the interaction of Wolbachia with its host.}, }
@article {pmid9538033, year = {1998}, author = {Schilthuizen, M and Gittenberger, E}, title = {Screening mollusks for Wolbachia infection.}, journal = {Journal of invertebrate pathology}, volume = {71}, number = {3}, pages = {268-270}, doi = {10.1006/jipa.1997.4739}, pmid = {9538033}, issn = {0022-2011}, mesh = {Animals ; Mollusca/*microbiology ; *Rickettsiaceae ; }, abstract = {We screened 38 species of mollusks for infection by Wolbachia, a bacterium that is a common endosymbiont in arthropods, where it induces alterations in reproduction. Using a PCR assay, we could not detect the symbiont in any of the samples, indicating that, in mollusks, it might be absent.}, }
@article {pmid9569646, year = {1997}, author = {Nakabachi, A and Ishikawa, H}, title = {Differential display of mRNAs related to amino acid metabolism in the endosymbiotic system of aphids.}, journal = {Insect biochemistry and molecular biology}, volume = {27}, number = {12}, pages = {1057-1062}, doi = {10.1016/s0965-1748(97)00092-1}, pmid = {9569646}, issn = {0965-1748}, mesh = {Acetyltransferases/genetics ; Amino Acid Sequence ; Amino Acids/genetics/*metabolism ; Amino-Acid N-Acetyltransferase ; Animals ; Aphids/*genetics ; Aspartate Aminotransferases/genetics ; Bacteria/*genetics ; Bacterial Proteins/genetics ; Chaperonins/genetics ; DNA, Complementary/genetics ; Molecular Sequence Data ; Phosphotransferases (Alcohol Group Acceptor)/genetics ; RNA, Messenger/*genetics ; Sequence Alignment ; Symbiosis/*genetics ; }, abstract = {Bacteriocytes harbouring Buchnera endosymbionts were isolated from young and old aphids, Acyrthosiphon pisum, and their mRNA populations were examined by the differential cDNA display and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) technique. It was suggested that several gene products are produced when the symbiotic system is well organized in the young insect, whereas others are produced after the system becomes degenerate in old aphids. Among the gene products that were actively synthesized in the symbiotic system of the young host were putative aspartate aminotransferase, homoserine kinase and N-acetylglutamate synthase. These findings were consistent with the hypothesis that the symbiotic system utilizes glutamate to produce essential amino acids.}, }
@article {pmid9560398, year = {1998}, author = {Bordenstein, SR and Werren, JH}, title = {Effects of A and B Wolbachia and host genotype on interspecies cytoplasmic incompatibility in Nasonia.}, journal = {Genetics}, volume = {148}, number = {4}, pages = {1833-1844}, pmid = {9560398}, issn = {0016-6731}, mesh = {Animals ; Cytoplasm ; Female ; Genotype ; Male ; Reproduction/physiology ; Rickettsiaceae/*physiology ; Sexual Behavior, Animal/physiology ; Species Specificity ; Symbiosis ; Wasps/*genetics/*physiology ; }, abstract = {Wolbachia endosymbionts cause postmating reproductive isolation between the sibling species Nasonia vitripennis and N. giraulti. Most Nasonia are doubly infected with a representative from each of the two major Wolbachia groups (A and B). This study investigates the role of single (A or B) and double (A and B) Wolbachia infections in interspecies cytoplasmic incompatibility (CI) and host genomic influences on the incompatibility phenotype. Results show that the single A Wolbachia harbored in N. vitripennis (wAv) is bidirectionally incompatible with the single A Wolbachia harbored in N. giraulti (wAg). Results also indirectly show that the N. vitripennis wBv is bidirectionally incompatible with the N. giraulti wBg. The findings support current phylogenetic evidence that suggests these single infections have independent origins and were acquired via horizontal transfer. The wAv Wolbachia expresses partial CI in the N. vitripennis nuclear background. However, following genomic replacement by introgression, wAv expresses complete CI in the N. giraulti background and remains bidirectionally incompatible with wAg. Results show that double infections can reinforce interspecies reproductive isolation through the addition of incompatibility types and indicate that the host genome can influence incompatibility levels. This study has implications for host-symbiont coevolution and the role of Wolbachia in speciation.}, }
@article {pmid9516544, year = {1998}, author = {Clark, MA and Baumann, L and Baumann, P}, title = {Sequence analysis of a 34.7-kb DNA segment from the genome of Buchnera aphidicola (endosymbiont of aphids) containing groEL, dnaA, the atp operon, gidA, and rho.}, journal = {Current microbiology}, volume = {36}, number = {3}, pages = {158-163}, doi = {10.1007/pl00006760}, pmid = {9516544}, issn = {0343-8651}, mesh = {*Algal Proteins ; Animals ; Aphids/*microbiology ; Bacteria/*genetics ; Bacterial Proteins/genetics ; Chaperonin 60/genetics ; Chromosome Mapping ; Codon ; DNA-Binding Proteins/genetics ; GTP-Binding Proteins/genetics ; Genes, Bacterial/*genetics ; Genome, Bacterial ; Membrane Proteins/genetics ; Molecular Sequence Data ; Open Reading Frames/genetics ; Operon/genetics ; Plant Proteins/genetics ; Promoter Regions, Genetic/genetics ; Proton-Translocating ATPases/genetics ; Replication Origin/genetics ; Sequence Analysis, DNA ; Terminator Regions, Genetic/genetics ; rhoB GTP-Binding Protein ; }, abstract = {Buchnera aphidicola is a prokaryotic endosymbiont of the aphid Schizaphis graminum. From past and present nucleotide sequence analyses of the B. aphidicola genome, we have assembled a 34. 7-kilobase (kb) DNA segment. This segment contains genes coding for 32 open reading frames (ORFs), which corresponded to 89.9% of the DNA. All of these ORFs could be identified with homologous regions of the Escherichia coli genome. The order of the genes with established functions was groELS-trmE-rnpA-rpmH-dnaA-dnaN-gyrB-atpCDGAH FEB-gidA-fdx-hscA- hscB-nifS-ilvDC-rep-trxA-rho. The order of genes in small DNA fragments was conserved in both B. aphidicola and E. coli. Most of these fragments were in approximately the same region of the E. coli genome. The latter organism, however, contained many additional inserted genes within and between the fragments. The results of the B. aphidicola genome analyses indicate that the endosymbiont has many properties of free-living bacteria.}, }
@article {pmid9501211, year = {1998}, author = {Van Hellemond, JJ and Opperdoes, FR and Tielens, AG}, title = {Trypanosomatidae produce acetate via a mitochondrial acetate:succinate CoA transferase.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {95}, number = {6}, pages = {3036-3041}, pmid = {9501211}, issn = {0027-8424}, mesh = {Acetates/*metabolism ; Acetyl Coenzyme A/metabolism ; Adenosine Diphosphate/metabolism ; Animals ; Cell Compartmentation ; Coenzyme A/metabolism ; Coenzyme A-Transferases/isolation &amp; purification/*metabolism ; Cricetinae ; Fasciola hepatica/enzymology ; Leishmania/enzymology ; Mitochondria/*enzymology ; Phosphates/metabolism ; Species Specificity ; Subcellular Fractions ; Succinate-CoA Ligases/metabolism ; Trypanosoma brucei brucei/enzymology ; Trypanosomatina/*enzymology ; }, abstract = {Hydrogenosome-containing anaerobic protists, such as the trichomonads, produce large amounts of acetate by an acetate:succinate CoA transferase (ASCT)/succinyl CoA synthetase cycle. The notion that mitochondria and hydrogenosomes may have originated from the same alpha-proteobacterial endosymbiont has led us to look for the presence of a similar metabolic pathway in trypanosomatids because these are the earliest-branching mitochondriate eukaryotes and because they also are known to produce acetate. The mechanism of acetate production in these organisms, however, has remained unknown. Four different members of the trypanosomatid family: promastigotes of Leishmania mexicana mexicana, L. infantum and Phytomonas sp., and procyclics of Trypanosoma brucei were analyzed as well as the parasitic helminth Fasciola hepatica. They all use a mitochondrial ASCT for the production of acetate from acetyl CoA. The succinyl CoA that is produced during acetate formation by ASCT is recycled presumably to succinate by a mitochondrial succinyl CoA synthetase, concomitantly producing ATP from ADP. The ASCT of L. mexicana mexicana promastigotes was further characterized after partial purification of the enzyme. It has a high affinity for acetyl CoA (Km 0.26 mM) and a low affinity for succinate (Km 6.9 mM), which shows that significant acetate production can occur only when high mitochondrial succinate concentrations prevail. This study identifies a metabolic pathway common to mitochondria and hydrogenosomes, which strongly supports a common origin for these two organelles.}, }
@article {pmid9504992, year = {1998}, author = {Thao, ML and Baumann, L and Baumann, P and Moran, NA}, title = {Endosymbionts (Buchnera) from the aphids Schizaphis graminum and Diuraphis noxia have different copy numbers of the plasmid containing the leucine biosynthetic genes.}, journal = {Current microbiology}, volume = {36}, number = {4}, pages = {238-240}, doi = {10.1007/s002849900301}, pmid = {9504992}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/*genetics/metabolism ; *Gene Dosage ; Isomerases/*genetics ; Leucine/biosynthesis ; Plasmids/genetics ; Symbiosis ; }, abstract = {The prokaryotic endosymbiont (Buchnera) of the aphid Schizaphis graminum contains 24 copies of a plasmid that has genes encoding enzymes of the leucine biosynthetic pathway while the endosymbiont of the related aphid Diuraphis noxia has only one copy of this plasmid. These results, in conjunction with similar results for the trpEG-containing plasmids, suggest that D. noxia has a reduced demand for endosymbiont-derived essential amino acids.}, }
@article {pmid9501436, year = {1998}, author = {Grosskopf, R and Janssen, PH and Liesack, W}, title = {Diversity and structure of the methanogenic community in anoxic rice paddy soil microcosms as examined by cultivation and direct 16S rRNA gene sequence retrieval.}, journal = {Applied and environmental microbiology}, volume = {64}, number = {3}, pages = {960-969}, pmid = {9501436}, issn = {0099-2240}, mesh = {Acetates/metabolism ; DNA, Ribosomal/*chemistry ; Euryarchaeota/genetics/growth &amp; development/*isolation &amp; purification ; Oryza ; RNA, Ribosomal, 16S/*genetics ; *Soil Microbiology ; }, abstract = {A dual approach consisting of cultivation and molecular retrieval of partial archaeal 16S rRNA genes was carried out to characterize the diversity and structure of the methanogenic community inhabiting the anoxic bulk soil of flooded rice microcosms. The molecular approach identified four groups of known methanogens. Three environmental sequences clustered with Methanobacterium bryantii and Methanobacterium formicicum, six were closely related but not identical to those of strains of Methanosaeta concilii, two grouped with members of the genus Methanosarcina, and two were related to the methanogenic endosymbiont of Plagiopyla nasuta. The cultivation approach via most-probable-number counts with a subsample of the same soil as an inoculum yielded cell numbers of up to 10(7) per g of dry soil for the H2-CO2-utilizing methanogens and of up to 10(6) for the acetate-utilizing methanogens. Strain VeH52, isolated from the terminal positive dilution on H2-CO2, grouped within the phylogenetic radiation characterized by M. bryantii and M. formicicum and the environmental sequences of the Methanobacterium-like group. A consortium of two distinct methanogens grew in the terminal positive culture on acetate. These two organisms showed absolute 16S rRNA gene identities with environmental sequences of the novel Methanosaeta-like group and the Methanobacterium-like group. Methanosarcina spp. were identified only in the less-dilute levels of the same dilution series on acetate. These data correlate well with acetate concentrations of about 11 microM in the pore water of this rice paddy soil. These concentrations are too low for the growth of known Methanosarcina spp. but are at the acetate utilization threshold of Methanosaeta spp. Thus, our data indicated Methanosaeta spp. and Methanobacterium spp. to be the dominant methanogenic groups in the anoxic rice soil, whereas Methanosarcina spp. appeared to be less abundant.}, }
@article {pmid9425245, year = {1998}, author = {Baumann, L and Baumann, P}, title = {Characterization of ftsZ, the cell division gene of Buchnera aphidicola (endosymbiont of aphids) and detection of the product.}, journal = {Current microbiology}, volume = {36}, number = {2}, pages = {85-89}, doi = {10.1007/s002849900284}, pmid = {9425245}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*genetics/microbiology ; Bacterial Proteins/*analysis/*genetics ; Cell Division/genetics ; *Cytoskeletal Proteins ; DNA, Bacterial/analysis/genetics ; Escherichia coli/genetics/physiology ; Gene Expression/genetics/physiology ; Genes, Insect/genetics ; Genetic Complementation Test ; Molecular Sequence Data ; Plasmids/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {Buchnera aphidicola, the endosymbiont of the aphid Schizaphis graminum, contains the gene ftsZ, which codes for a protein involved in the initiation of septum formation during cell division. With immunological techniques, this protein has been detected in cell-free extracts of the endosymbiont. Nucleotide sequence determination of a 6.4-kilobase B. aphidicola DNA fragment has indicated that, as in E. coli, ftsZ is adjacent to genes coding for other cell division proteins as well as genes involved in murein synthesis (murC-ddlB-ftsA-ftsZ). Although B. aphidicola ftsZ is expressed in E. coli, it cannot complement E. coli ftsZ mutants. High levels of B. aphidicola FtsZ results in the formation of long filamentous E. coli cells, suggesting that this protein interferes with cell division. The presence of FtsZ indicates that in this, as well as in many other previously described properties, B. aphidicola resembles free-living bacteria.}, }
@article {pmid9486285, year = {1998}, author = {Furla, P and Bénazet-Tambutté, S and Jaubert, J and Allemand, D}, title = {Functional polarity of the tentacle of the sea anemone Anemonia viridis: role in inorganic carbon acquisition.}, journal = {The American journal of physiology}, volume = {274}, number = {2}, pages = {R303-10}, doi = {10.1152/ajpregu.1998.274.2.R303}, pmid = {9486285}, issn = {0002-9513}, mesh = {Amiloride/pharmacology ; Animals ; Bicarbonates/metabolism ; Carbon/*metabolism ; Endoderm/metabolism ; Hydrogen-Ion Concentration ; Hydroxides/metabolism ; Kinetics ; Light ; Oxygen/metabolism ; Photosynthesis ; Sea Anemones/*anatomy &amp; histology/*metabolism ; Sodium/pharmacology ; }, abstract = {The oral epithelial layers of anthozoans have a polarized morphology: photosynthetic endosymbionts live within endodermal cells facing the coelenteric cavity and are separated from the external seawater by the ectodermal layer and the mesoglea. To study if this morphology plays a role in the supply of inorganic carbon for symbiont photosynthesis, we measured the change in pH and the rate of OH- (H+) fluxes induced by each cell layer on a tentacle of the sea anemone Anemonia viridis. Light-induced pH increase of the medium bathing the endodermal layers led to the generation of a transepithelial pH gradient of approximately 0.8 pH units across the tentacle, whereas darkness induced acidification of this medium. The light-induced pH change was associated with an increase of total alkalinity. Only the endodermal layer was able to induce a net OH- secretion (H+ absorption). The light-induced OH- secretion by the endodermal cell layer was dependent on the presence of HCO3- in the compartment facing the ectoderm and was sensitive to several inhibitors of ion transport. [14C] HCO3- incorporation into photosynthates confirmed the ectodermal supply, the extent of which varied from 25 to > 90%, according to HCO3- availability. Our results suggest that the light-induced OH- secretion by the endodermal cell layer followed the polarized transport of HCO3- and its subsequent decarboxylation within the endodermal cell layer. This polarity may play a significant role both in inorganic carbon absorption and in the control of light-enhanced calcification in scleractinian corals.}, }
@article {pmid9419358, year = {1998}, author = {Roger, AJ and Svärd, SG and Tovar, J and Clark, CG and Smith, MW and Gillin, FD and Sogin, ML}, title = {A mitochondrial-like chaperonin 60 gene in Giardia lamblia: evidence that diplomonads once harbored an endosymbiont related to the progenitor of mitochondria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {95}, number = {1}, pages = {229-234}, pmid = {9419358}, issn = {0027-8424}, support = {GM53835/GM/NIGMS NIH HHS/United States ; AI24285/AI/NIAID NIH HHS/United States ; P01 DK035108/DK/NIDDK NIH HHS/United States ; DK35108/DK/NIDDK NIH HHS/United States ; //Wellcome Trust/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Chaperonin 60/*genetics ; Cloning, Molecular ; Evolution, Molecular ; Giardia lamblia/*genetics ; Mitochondria ; Molecular Sequence Data ; Phylogeny ; Symbiosis ; }, abstract = {Diplomonads, parabasalids, as represented by trichomonads, and microsporidia are three protist lineages lacking mitochondria that branch earlier than all other eukaryotes in small subunit rRNA and elongation factor phylogenies. The absence of mitochondria and plastids in these organisms suggested that they diverged before the origin of these organelles. However, recent discoveries of mitochondrial-like heat shock protein 70 and/or chaperonin 60 (cpn60) genes in trichomonads and microsporidia imply that the ancestors of these two groups once harbored mitochondria or their endosymbiotic progenitors. In this report, we describe a mitochondrial-like cpn60 homolog from the diplomonad parasite Giardia lamblia. Northern and Western blots reveal that the expression of cpn60 is independent of cellular stress and, except during excystation, occurs throughout the G. lamblia life cycle. Phylogenetic analyses position the G. lamblia cpn60 in a clade that includes mitochondrial and hydrogenosomal cpn60 proteins. The most parsimonious interpretation of these data is that the cpn60 gene was transferred from the endosymbiotic ancestors of mitochondria to the nucleus early in eukaryotic evolution, before the divergence of the diplomonads and trichomonads from other extant eukaryotic lineages. A more complicated explanation requires that these genes originated from distinct alpha-proteobacterial endosymbioses that formed transiently within these protist lineages.}, }
@article {pmid9419245, year = {1997}, author = {Ishida, K and Cao, Y and Hasegawa, M and Okada, N and Hara, Y}, title = {The origin of chlorarachniophyte plastids, as inferred from phylogenetic comparisons of amino acid sequences of EF-Tu.}, journal = {Journal of molecular evolution}, volume = {45}, number = {6}, pages = {682-687}, doi = {10.1007/pl00006272}, pmid = {9419245}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Base Sequence ; Eukaryota/*chemistry/genetics ; *Evolution, Molecular ; Molecular Sequence Data ; Multigene Family ; Peptide Elongation Factor Tu/*chemistry/genetics/isolation &amp; purification ; Photosynthesis/genetics ; *Phylogeny ; Plastids/*chemistry/genetics ; Polymerase Chain Reaction ; }, abstract = {A molecular phylogenetic analysis of elongation factor Tu (EF-Tu) proteins from plastids was performed in an attempt to identify the origin of chlorarachniophyte plastids, which are considered to have evolved from the endosymbiont of a photosynthetic eukaryote. Partial sequences of the genes for plastid EF-Tu proteins (1,080-1,089 bp) were determined for three algae that contain chlorophyll b, namely, Gymnochlora stellata (Chlorarachniophyceae), Bryopsis maxima (Ulvophyceae), and Pyramimonas disomata (Prasinophyceae). The deduced amino acid sequences were used to construct phylogenetic trees of the plastid and bacterial EF-Tu proteins by the maximum likelihood, the maximum parsimony, and the neighbor joining methods. The trees obtained in the present analysis suggest that all plastids that contain chlorophyll b are monophyletic and that the chlorarachniophyte plastids are closely related to those of the Ulvophyceae. The phylogenetic trees also suggest that euglenophyte plastids are closely related to prasinophycean plastids. The results indicate that the chlorarachniophyte plastids evolved from a green algal endosymbiont that was closely related to the Ulvophyceae and that at least two secondary endosymbiotic events have occurred in the lineage of algae with plastids that contain chlorophyll b.}, }
@article {pmid9382838, year = {1997}, author = {Hirt, RP and Healy, B and Vossbrinck, CR and Canning, EU and Embley, TM}, title = {A mitochondrial Hsp70 orthologue in Vairimorpha necatrix: molecular evidence that microsporidia once contained mitochondria.}, journal = {Current biology : CB}, volume = {7}, number = {12}, pages = {995-998}, doi = {10.1016/s0960-9822(06)00420-9}, pmid = {9382838}, issn = {0960-9822}, mesh = {Animals ; Base Sequence ; Biological Evolution ; DNA, Protozoan ; HSP70 Heat-Shock Proteins/chemistry/classification/*genetics ; Microsporida/*genetics/ultrastructure ; *Mitochondria ; Molecular Sequence Data ; Phylogeny ; Symbiosis ; }, abstract = {Microsporidia are small (1-20 micron) obligate intracellular parasites of a variety of eukaryotes, and they are serious opportunistic pathogens of immunocompromised patients [1]. Microsporidia are often assigned to the first branch in gene trees of eukaryotes [2,3], and are reported to lack mitochondria [2,4]. Like diplomonads and trichomonads, microsporidia are hypothesised to have diverged from the main eukaryotic stock prior to the event that led to the mitochondrion endosymbiosis [2,4]. They have thus assumed importance as putative relics of premitochondrion eukaryote evolution. Recent data have now revealed that diplomonads and trichomonads contain genes that probably originated from the mitochondrion endosymbiont [5-9], leaving microsporidia as chief candidates for an extant primitively amitochondriate eukaryote group. We have now identified a gene in the microsporidium Vairimorpha necatrix that appears to be orthologous to the eukaryotic (symbiont-derived) Hsp70 gene, the protein product of which normally functions in mitochondria. The simplest interpretation of our data is that microporidia have lost mitochondria while retaining genetic evidence of their past presence. This strongly suggests that microsporidia are not primitively amitochondriate and makes feasible an evolutionary scenario whereby all extant eukaryotes share a common ancestor which contained mitochondria.}, }
@article {pmid9468790, year = {1997}, author = {Gilson, PR and Maier, UG and McFadden, GI}, title = {Size isn't everything: lessons in genetic miniaturisation from nucleomorphs.}, journal = {Current opinion in genetics &amp; development}, volume = {7}, number = {6}, pages = {800-806}, doi = {10.1016/s0959-437x(97)80043-3}, pmid = {9468790}, issn = {0959-437X}, mesh = {Cell Nucleus/genetics ; Eukaryota/*genetics ; *Genome ; Introns ; Particle Size ; Proteins/metabolism ; Spliceosomes ; *Symbiosis ; }, abstract = {Nucleomorphs are the vestigial nuclear genomes of eukaryotic algal cells now existing as endosymbionts within a host cell. Molecular investigation of the endosymbiont genomes has allowed important insights into the process of eukaryote/eukaryote cell endosymbiosis and has also disclosed a plethora of interesting genetic phenomena. Although nucleomorph genomes retain classic eukaryotic traits such as linear chromosomes, telomeres, and introns, they are highly reduced and modified. Nucleomorph chromosomes are extremely small and encode compacted genes which are disrupted by the tiniest spliceosomal introns found in any eukaryote. Mechanisms of gene expression within nucleomorphs have apparently accommodated increasingly parsimonious DNA usage by permitting genes to become co-transcribed or, in select cases, to overlap.}, }
@article {pmid9388293, year = {1997}, author = {Schneider, R and Brors, B and Bürger, F and Camrath, S and Weiss, H}, title = {Two genes of the putative mitochondrial fatty acid synthase in the genome of Saccharomyces cerevisiae.}, journal = {Current genetics}, volume = {32}, number = {6}, pages = {384-388}, doi = {10.1007/s002940050292}, pmid = {9388293}, issn = {0172-8083}, mesh = {3-Oxoacyl-(Acyl-Carrier-Protein) Reductase ; Acyl-Carrier Protein S-Malonyltransferase ; Acyltransferases/genetics ; Alcohol Oxidoreductases/genetics ; Amino Acid Sequence ; Fatty Acid Synthases/*genetics ; Genes, Fungal/*genetics ; Genetic Complementation Test ; Mitochondria/*enzymology/metabolism ; Molecular Sequence Data ; Oxidative Phosphorylation ; Saccharomyces cerevisiae/enzymology/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {In order to find further genes of the mitochondrial fatty acid synthase, we searched the genome of Saccharomyces cerevisiae for sequences that are homologous to conserved regions of bacterial fatty acid synthase genes. We found the gene products of ORF YKL055c (EMBL Accession No. X75781) and of YOR221C (EMBL Accession No. X92441) to be homologous to bacterial 3-oxoacyl-(acyl carrier protein) reductases and to malonyl-CoA:ACP-transferases, respectively. We disrupted these two genes which in both cases led to a respiratory deficient phenotype, as is the case for the genes encoding a mitochondrial acyl carrier protein and a beta-ketoacyl-ACP synthase. We propose to call the above mentioned genes OAR1 [3-oxo-acyl-(acyl carrier protein) reductase] and MCT1 (malonyl-CoA:ACP transferase). They are presumed to be part of a type-II mitochondrial fatty acid synthase, a relic of the endosymbiontic origin of mitochondria, delivering substrates for phospholipid re-modelling and/or repair.}, }
@article {pmid9435125, year = {1997}, author = {Fernandes, O and Teixeira, MM and Sturm, NR and Sousa, MA and Camargo, EP and Degrave, WM and Campbell, DA}, title = {Mini-exon gene sequences define six groups within the genus Crithidia.}, journal = {The Journal of eukaryotic microbiology}, volume = {44}, number = {6}, pages = {535-539}, doi = {10.1111/j.1550-7408.1997.tb05958.x}, pmid = {9435125}, issn = {1066-5234}, support = {T32-AI07323/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; Crithidia/*genetics ; DNA Probes ; Exons/*genetics ; Genes, Protozoan/*genetics ; Genetic Markers ; Molecular Probe Techniques ; Molecular Sequence Data ; Polymerase Chain Reaction/methods ; Repetitive Sequences, Nucleic Acid/*genetics ; Sequence Analysis, DNA ; }, abstract = {To develop molecular markers for lower trypanosmatids, we have examined the mini-exon gene repeats of 17 isolates that were classified as Crithidia by traditional methods. Representative repeats were amplified by polymerase chain reaction and the amplification products were cloned and used as hybridization probes against genomic DNA. Six hybridization groups of Crithidia were defined on the basis of the DNA blotting experiments. The three endosymbiont-bearing species (C. deanei, C. desouzai and C. oncopelti) and C. acanthocephali each belonged to single-member hybridization groups, while the C. fasciculata group contained additional named and undesignated species. The Crithidia lucilae thermophila probe hybridized to multiple undesignated isolates. The DNA sequence of the cloned products revealed that the specificity of the hybridization probes was due to substantial differences in the intron and the nontranscribed spacer regions. These data indicate substantial heterogeneity within the mini-exon gene locus of the taxon Crithidia.}, }
@article {pmid9420234, year = {1998}, author = {Hogenhout, SA and van der Wilk, F and Verbeek, M and Goldbach, RW and van den Heuvel, JF}, title = {Potato leafroll virus binds to the equatorial domain of the aphid endosymbiotic GroEL homolog.}, journal = {Journal of virology}, volume = {72}, number = {1}, pages = {358-365}, pmid = {9420234}, issn = {0022-538X}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology/*virology ; Bacteria/*genetics/*metabolism ; Base Sequence ; Binding Sites/genetics ; Chaperonin 60/*genetics/*metabolism ; DNA, Bacterial/genetics ; Escherichia coli/genetics ; Genes, Bacterial ; Hemolymph/virology ; Luteovirus/*metabolism/pathogenicity ; Molecular Sequence Data ; Operon ; Protein Binding ; Sequence Deletion ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {A GroEL homolog with a molecular mass of 60 kDa, produced by the primary endosymbiotic bacterium (a Buchnera sp.) of Myzus persicae and released into the hemolymph, has previously been shown to be a key protein in the transmission of potato leafroll virus (PLRV). Like other luteoviruses and pea enation mosaic virus, PLRV readily binds to extracellular Buchnera GroEL, and in vivo interference in this interaction coincides with reduced capsid integrity and loss of infectivity. To gain more knowledge of the nature of the association between PLRV and Buchnera GroEL, the groE operon of the primary endosymbiont of M. persicae (MpB groE) and its flanking sequences were characterized and the PLRV-binding domain of Buchnera GroEL was identified by deletion mutant analysis. MpB GroEL has extensive sequence similarity (92%) with Escherichia coli GroEL and other members of the chaperonin-60 family. The genomic organization of the Buchnera groE operon is similar to that of the groE operon of E. coli except that a constitutive promoter sequence could not be identified; only the heat shock promoter was present. By a virus overlay assay of protein blots, it was shown that purified PLRV bound as efficiently to recombinant MpB GroEL (expressed in E. coli) as it did to wild-type MpB GroEL. Mutational analysis of the gene encoding MpB GroEL revealed that the PLRV-binding site was located in the so-called equatorial domain and not in the apical domain which is generally involved in polypeptide binding and folding. Buchnera GroEL mutants lacking the entire equatorial domain or parts of it lost the ability to bind PLRV. The equatorial domain is made up of two regions at the N and C termini that are not contiguous in the amino acid sequence but are in spatial proximity after folding of the GroEL polypeptide. Both the N- and C-terminal regions of the equatorial domain were implicated in virus binding.}, }
@article {pmid9371794, year = {1997}, author = {Feng, DF and Cho, G and Doolittle, RF}, title = {Determining divergence times with a protein clock: update and reevaluation.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {94}, number = {24}, pages = {13028-13033}, pmid = {9371794}, issn = {0027-8424}, mesh = {Archaea/genetics ; Bacteria/genetics ; *Evolution, Molecular ; Phylogeny ; Proteins/*genetics ; }, abstract = {A recent study of the divergence times of the major groups of organisms as gauged by amino acid sequence comparison has been expanded and the data have been reanalyzed with a distance measure that corrects for both constraints on amino acid interchange and variation in substitution rate at different sites. Beyond that, the availability of complete genome sequences for several eubacteria and an archaebacterium has had a great impact on the interpretation of certain aspects of the data. Thus, the majority of the archaebacterial sequences are not consistent with currently accepted views of the Tree of Life which cluster the archaebacteria with eukaryotes. Instead, they are either outliers or mixed in with eubacterial orthologs. The simplest resolution of the problem is to postulate that many of these sequences were carried into eukaryotes by early eubacterial endosymbionts about 2 billion years ago, only very shortly after or even coincident with the divergence of eukaryotes and archaebacteria. The strong resemblances of these same enzymes among the major eubacterial groups suggest that the cyanobacteria and Gram-positive and Gram-negative eubacteria also diverged at about this same time, whereas the much greater differences between archaebacterial and eubacterial sequences indicate these two groups may have diverged between 3 and 4 billion years ago.}, }
@article {pmid9327558, year = {1997}, author = {Niebylski, ML and Peacock, MG and Fischer, ER and Porcella, SF and Schwan, TG}, title = {Characterization of an endosymbiont infecting wood ticks, Dermacentor andersoni, as a member of the genus Francisella.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {10}, pages = {3933-3940}, pmid = {9327558}, issn = {0099-2240}, mesh = {Animals ; Arachnid Vectors/*microbiology/ultrastructure ; Base Sequence ; Chlorocebus aethiops ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Dermacentor/*microbiology/ultrastructure ; Female ; Francisella/genetics/*isolation &amp; purification/ultrastructure ; Microscopy, Electron ; Ovary/microbiology ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Symbiosis ; Vero Cells ; }, abstract = {A microorganism (Dermacantor andersoni symbiont [DAS]) infecting Rocky Mountain wood ticks (D. andersoni) collected in the Bitterroot Mountains of western Montana was characterized as an endosymbiont belonging to the genus Francisella. Previously described as Wolbachia like, the organism's DNA was amplified from both naturally infected tick ovarial tissues and Vero cell cultures by PCR assay with primer sets derived from eubacterial 16S ribosomal DNA (rDNA) and Francisella membrane protein genes. The 16S rDNA gene sequence of the DAS was most similar (95.4%) to that of Francisella tularensis subsp. tularensis. Through a combination of Giménez staining, PCR assay, and restriction fragment length polymorphism analysis, 102 of 108 female ticks collected from 1992 to 1996 were infected. Transovarial transmission to female progeny was 95.6%, but we found no evidence of horizontal transmission.}, }
@article {pmid9327557, year = {1997}, author = {Noda, H and Munderloh, UG and Kurtti, TJ}, title = {Endosymbionts of ticks and their relationship to Wolbachia spp. and tick-borne pathogens of humans and animals.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {10}, pages = {3926-3932}, pmid = {9327557}, issn = {0099-2240}, support = {AR37909/AR/NIAMS NIH HHS/United States ; }, mesh = {Animals ; Arachnid Vectors/*microbiology ; Bacteria/classification/genetics/*isolation &amp; purification ; Base Sequence ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Dogs ; Humans ; Ixodes/microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae/classification/genetics/*isolation &amp; purification ; Symbiosis ; Ticks/*microbiology ; }, abstract = {The presence, internal distribution, and phylogenetic position of endosymbiotic bacteria from four species of specific-pathogen-free ticks were studied. These included the hard ticks Ixodes scapularis (the black-legged tick), Rhipicephalus sanguineus (the brown dog tick), and Haemaphysalis longicornis and the African soft tick Ornithodoros moubata. PCR assays for bacteria, using two sets of general primers for eubacterial 16S and 23S rRNA genes (rDNAs) and seven sets of specific primers for wolbachial, rickettsial, or Francisella genes, indicated that I. scapularis possessed symbiotic rickettsiae in the ovaries and that the other species harbored eubacteria in both the ovaries and Malpighian tubules. Phylogenetic analysis based on the sequence of 16S rDNA indicated that the symbiont of I. scapularis belonged to the alpha subgroup of proteobacteria and was closely related to the members of the genus Rickettsia. The other species had similar microorganisms in the ovaries and Malpighian tubules, which belonged to the gamma subgroup of proteobacteria, and formed a monophyletic group with the Q-fever pathogen, Coxiella burnetii. O. moubata harbored another symbiont, which formed a monophyletic group with Francisella tularensis and Wolbachia persica, the latter a symbiont previously isolated from Malpighian tubules of the soft tick Argas (Persicargas) arboreus. Thus, the symbionts of these four tick species were not related to the Wolbachia species found in insects. The two symbionts that live in the Malpighian tubules, one closely related to C. burnetii and the other closely related to F. tularensis, appear to be of ancient origin and be widely distributed in ticks.}, }
@article {pmid9311800, year = {1997}, author = {van den Heuvel, JF and Bruyère, A and Hogenhout, SA and Ziegler-Graff, V and Brault, V and Verbeek, M and van der Wilk, F and Richards, K}, title = {The N-terminal region of the luteovirus readthrough domain determines virus binding to Buchnera GroEL and is essential for virus persistence in the aphid.}, journal = {Journal of virology}, volume = {71}, number = {10}, pages = {7258-7265}, pmid = {9311800}, issn = {0022-538X}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology/*virology ; Bacteria/virology ; *Bacterial Physiological Phenomena ; Brassica ; Capsid/chemistry/*physiology ; Chaperonin 60/isolation &amp; purification/*metabolism/ultrastructure ; Conserved Sequence ; Escherichia coli/metabolism ; Hemolymph/virology ; Luteovirus/genetics/*physiology ; Molecular Sequence Data ; Molecular Weight ; Peas/virology ; Sequence Alignment ; Sequence Homology, Amino Acid ; Species Specificity ; Symbiosis ; }, abstract = {Luteoviruses and the luteovirus-like pea enation mosaic virus (PEMV; genus Enamovirus) are transmitted by aphids in a circulative, nonreplicative manner. Acquired virus particles persist for several weeks in the aphid hemolymph, in which a GroEL homolog, produced by the primary endosymbiont of the aphid, is abundantly present. Six subgroup II luteoviruses and PEMV displayed a specific but differential affinity for Escherichia coli GroEL and GroEL homologs isolated from the endosymbiotic bacteria of both vector and nonvector aphid species. These observations suggest that the basic virus-binding capacity resides in a conserved region of the GroEL molecule, although other GroEL domains may influence the efficiency of binding. Purified luteovirus and enamovirus particles contain a major 22-kDa coat protein (CP) and lesser amounts of an approximately 54-kDa readthrough protein, expressed by translational readthrough of the CP into the adjacent open reading frame. Beet western yellows luteovirus (BWYV) mutants devoid of the readthrough domain (RTD) did not bind to Buchnera GroEL, demonstrating that the RTD (and not the highly conserved CP) contains the determinants for GroEL binding. In vivo studies showed that virions of these BWYV mutants were significantly less persistent in the aphid hemolymph than were virions containing the readthrough protein. These data suggest that the Buchnera GroEL-RTD interaction protects the virus from rapid degradation in the aphid. Sequence comparison analysis of the RTDs of different luteoviruses and PEMV identified conserved residues potentially important in the interaction with Buchnera GroEL.}, }
@article {pmid9311125, year = {1997}, author = {Benchimol, M and Durand, R and Almeida, JC}, title = {A double membrane surrounds the hydrogenosomes of the anaerobic fungus Neocallimastix frontalis.}, journal = {FEMS microbiology letters}, volume = {154}, number = {2}, pages = {277-282}, doi = {10.1111/j.1574-6968.1997.tb12656.x}, pmid = {9311125}, issn = {0378-1097}, mesh = {Animals ; Cell Membrane/ultrastructure ; Fungi/metabolism/*ultrastructure ; Hydrogen/*metabolism ; Immunohistochemistry ; Rumen/microbiology ; Sheep ; }, abstract = {The structure of hydrogenosomes of the anaerobic fungus Neocallimastix frontalis was analyzed using routine preparations for transmission electron microscopy, freeze-fracture and immunocytochemistry. They appeared as round or elongated structures, always enveloped by two distinct, but tightly apposed membranes. Images of organelle division were very similar to those observed in trichomonad protozoa. These observations suggest that hydrogenosomes are homologous organelles in unrelated species weakening the hypothesis of a polyphyletic origin and supporting the evidence that fungal hydrogenosomes are probably derived from an endosymbiont relationship.}, }
@article {pmid9299222, year = {1997}, author = {Rouhbakhsh, D and Clark, MA and Baumann, L and Moran, NA and Baumann, P}, title = {Evolution of the tryptophan biosynthetic pathway in Buchnera (aphid endosymbionts): studies of plasmid-associated trpEG within the genus Uroleucon.}, journal = {Molecular phylogenetics and evolution}, volume = {8}, number = {2}, pages = {167-176}, doi = {10.1006/mpev.1997.0419}, pmid = {9299222}, issn = {1055-7903}, mesh = {Animals ; *Anthranilate Synthase ; Aphids/*genetics/*microbiology ; Bacteria/classification/*genetics/*metabolism ; Base Sequence ; *Evolution, Molecular ; Molecular Sequence Data ; *Nitrogenous Group Transferases ; Phylogeny ; Plasmids/genetics ; Replication Origin ; Symbiosis/genetics ; Transferases/genetics ; Tryptophan/*biosynthesis/*genetics ; }, abstract = {Aphids obtain tryptophan from prokaryotic endosymbionts assigned to the genus Buchnera. The rate-limiting enzyme in tryptophan biosynthes, anthranilate synthase, is encoded by the genes trpE and trpG. In Buchnera within the family Aphididae, trpEG is plasmid-borne, apparently as an adaptation to overproduce tryptophan for hosts. To explore the evolution of these plasmids, sequences for trpEG, the upstream region containing the plasmid origin of replication, and chromosomal trpB were obtained for Buchnera of three species in the aphid genus Uroleucon and analyzed together with sequences for six other aphid species. Phylogenies based on trpB and trpEG agree with each other and with previous views of aphid phylogeny. Synonymous substitutions are about twice as high for plasmid-borne genes as for chromosomal genes in the same lineages, suggesting higher mutation rates for genes on plasmids. Nonsynonymous rates for trpEG are accelerated within Buchnera of Uroleucon, indicating a change in selection intensity within this genus. Accelerated evolution within Uroleucon also seems to characterize the upstream region containing the putative origin of replication.}, }
@article {pmid9293000, year = {1997}, author = {Hughes, DS and Felbeck, H and Stein, JL}, title = {A histidine protein kinase homolog from the endosymbiont of the hydrothermal vent tubeworm Riftia pachyptila.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {9}, pages = {3494-3498}, pmid = {9293000}, issn = {0099-2240}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/*enzymology/*genetics/isolation &amp; purification ; Base Sequence ; Chromosome Mapping ; Cloning, Molecular ; DNA Primers/genetics ; DNA, Bacterial/genetics ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Histidine Kinase ; Molecular Sequence Data ; Open Reading Frames ; Polychaeta/*microbiology ; Polymerase Chain Reaction ; Protein Kinases/*genetics ; Sequence Homology, Amino Acid ; Signal Transduction ; Symbiosis ; }, abstract = {The uncultivated bacterial endosymbionts of the hydrothermal vent tubeworm Riftia pachyptila play a central role in providing their host with fixed carbon. While this intimate association between host and symbiont indicates tight integration and coordination of function via cellular communication mechanisms, no such systems have been identified. To elucidate potential signal transduction pathways in symbionts that may mediate symbiont-host communication, we cloned and characterized a gene encoding a histidine protein kinase homolog isolated from a symbiont fosmid library. The gene, designated rssA (for Riftia symbiont signal kinase), resembles known sensor kinases and encodes a protein capable of phosphorylating response regulators in Escherichia coli. A second open reading frame, rssB (for Riftia symbiont signal regulator), encodes a protein similar to known response regulators. These results suggest that the symbionts utilize a phosphotransfer signal transduction mechanism to communicate external signals that may mediate recognition of or survival within the host. The specific signals eliciting a response by the signal transduction proteins of the symbiont remain to be elucidated.}, }
@article {pmid9284565, year = {1997}, author = {Feldman, RA and Black, MB and Cary, CS and Lutz, RA and Vrijenhoek, RC}, title = {Molecular phylogenetics of bacterial endosymbionts and their vestimentiferan hosts.}, journal = {Molecular marine biology and biotechnology}, volume = {6}, number = {3}, pages = {268-277}, pmid = {9284565}, issn = {1053-6426}, support = {TW00735-01/TW/FIC NIH HHS/United States ; }, mesh = {Animals ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; DNA, Ribosomal/genetics ; Genetic Variation/genetics ; Gram-Negative Chemolithotrophic Bacteria/*genetics ; Hot Temperature ; Molecular Sequence Data ; Oxidation-Reduction ; *Phylogeny ; Polychaeta/*microbiology ; RNA, Ribosomal, 16S/genetics ; Sulfur/*metabolism ; *Symbiosis ; Whales ; }, abstract = {Vestimentiferan tube worms from deep-sea hydrothermal vents and cold-water seeps rely entirely on sulfur-oxidizing bacterial endosymbionts for nutriment. We examined host-symbiont co-evolution by comparing phylogenetic trees from symbiont 16S ribosomal DNA and host mitochondrial COI genes. The endosymbionts comprised two distinct clades, one associated with tube worms from basaltic vent habitats and the other associated with tube worms from sedimented seep-like environments. Within each symbiont clade, 16S rDNA sequences were nearly identical, suggesting that vent vestimentiferans share a single endosymbiont species that is distinct from the seep endosymbiont species. A third endosymbiont type, related to the seep species, was found in a tube worm collected from a whale carcass. Our results are consistent with a horizontal model of symbiont transmission.}, }
@article {pmid9401467, year = {1997}, author = {Masui, S and Sasaki, T and Ishikawa, H}, title = {groE-homologous operon of Wolbachia, an intracellular symbiont of arthropods: a new approach for their phylogeny.}, journal = {Zoological science}, volume = {14}, number = {4}, pages = {701-706}, doi = {10.2108/zsj.14.701}, pmid = {9401467}, issn = {0289-0003}, mesh = {Amino Acid Sequence ; Animals ; Arthropods/*microbiology ; Bacterial Proteins/*genetics ; Base Sequence ; Chaperonins ; Escherichia coli Proteins ; Heat-Shock Proteins/*genetics ; Molecular Sequence Data ; *Operon ; Phylogeny ; Rickettsia/classification/*genetics ; }, abstract = {Wolbachia, a member of rickettsia found in the cells of many arthropod species, are cytoplasmically inherited bacteria which interfere with host's sexuality and reproduction. Wolbachia strains have been phylogenetically divided into A and B groups based on the nucleotide sequences of their ftsZ genes. In an attempt to further define the phylogenetical relationship among these endosymbionts, we cloned and sequenced the entire length of the groE operon of a Wolbachia harbored by a cricket. The operon encoded two heat shock proteins, which represented the third and fourth proteins of any Wolbachia ever characterized. Also, 800 bp stretches of the groE operons of several other Wolbachia were sequenced, and a phylogenetic tree was constructed based on the results. The groE tree defined the relationship among A group Wolbachia strains that had not been successfully resolved by the ftsZ tree, and suggested unexpected horizontal transmission of these bacteria.}, }
@article {pmid9272448, year = {1997}, author = {Hypsa, V and Aksoy, S}, title = {Phylogenetic characterization of two transovarially transmitted endosymbionts of the bedbug Cimex lectularius (Heteroptera:Cimicidae).}, journal = {Insect molecular biology}, volume = {6}, number = {3}, pages = {301-304}, doi = {10.1046/j.1365-2583.1997.00178.x}, pmid = {9272448}, issn = {0962-1075}, support = {AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*genetics ; Bedbugs/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Female ; Molecular Sequence Data ; Ovary/microbiology ; *Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsieae/*genetics ; *Symbiosis ; }, abstract = {Two different inherited bacterial symbionts from ovary tissue of the bedbug Cimex lectularius were characterized by gene amplification and sequencing analysis of their 16S rDNA gene. The first bacterium belongs to the Wolbachia subgroup of the alpha-Proteobacteria, the second is a member of the gamma-subdivision, and is closely related to the bacterial parasite of the leafhopper Euscelidius variegatus (BEV) which was shown to be capable of transovarial transmission. The high similarity (> 97%) between the C. lectularius symbiont and BEV indicates that these two microorganisms belong to the same lineage and share the ability to invade distant insect hosts to fulfill their symbiotic functions and to establish transovarial transmission to future generations.}, }
@article {pmid9247927, year = {1997}, author = {Germot, A and Philippe, H and Le Guyader, H}, title = {Evidence for loss of mitochondria in Microsporidia from a mitochondrial-type HSP70 in Nosema locustae.}, journal = {Molecular and biochemical parasitology}, volume = {87}, number = {2}, pages = {159-168}, doi = {10.1016/s0166-6851(97)00064-9}, pmid = {9247927}, issn = {0166-6851}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA Primers/genetics ; Eukaryotic Cells ; Genes, Protozoan ; HSP70 Heat-Shock Proteins/*genetics ; Microsporida/*genetics/ultrastructure ; Mitochondria/*genetics ; Molecular Sequence Data ; Nosema/*genetics/ultrastructure ; Open Reading Frames ; Phylogeny ; Polymerase Chain Reaction ; Protozoan Proteins/genetics ; Sequence Homology, Amino Acid ; }, abstract = {In molecular phylogenies based on ribosomal RNA, three amitochondriate protist lineages, Microsporidia, Metamonada (including diplomonads) and Parabasala (including trichomonads), are the earliest offshoots of the eukaryotic tree. As an explantation for the lack of mitochondria in these organisms, the hypothesis that they have diverged before the mitochondrial endosymbiosis is preferred to the less parsimonious hypothesis of several independent losses of the organelle. Nevertheless, if they had descended from mitochondrion-containing ancestors, it may be possible to find in their nuclear DNA genes that derive from the endosymbiont which gave rise to mitochondria. Based on similar evidence, secondary losses of mitochondria have recently been suggested for Entamoeba histolytica and for Trichomonas vaginalis. In this study, we have isolated a gene encoding a chaperone protein (HSP70, 70 kDa heat shock protein) from the microspordian Nosema locustae. In phylogenetic trees, this HSP70 was located within a group of sequences that in other lineages is targetted to the mitochondrial compartment, itself included in the proteobacterial clade. In addition, the N. locustae protein contained the GDAW(V) motif shared by mitochondrial and proteobacterial sequences, with only one conservative substitution. Moreover, microsporidia, a phylum which was assumed to emerge close to the base of the eukaryotic tree, appears as the sister-group of fungi in the HSP70 phylogeny, in agreement with some ultrastructural characters and phylogenies based on alpha- and beta-tubulins. Loss of mitochondria, now demonstrated for several amitochondriate groups, indicates that the common ancestor of all the extant eukaryotic species could have been a mitochondriate eukaryote.}, }
@article {pmid9244264, year = {1997}, author = {van Ham, RC and Moya, A and Latorre, A}, title = {Putative evolutionary origin of plasmids carrying the genes involved in leucine biosynthesis in Buchnera aphidicola (endosymbiont of aphids).}, journal = {Journal of bacteriology}, volume = {179}, number = {15}, pages = {4768-4777}, pmid = {9244264}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Base Sequence ; DNA, Ribosomal ; *Evolution, Molecular ; Genes, Bacterial ; Gram-Negative Bacteria/classification/*genetics ; Leucine/*biosynthesis ; Molecular Sequence Data ; Open Reading Frames ; Phylogeny ; *Plasmids ; Regulatory Sequences, Nucleic Acid ; Replication Origin ; Sequence Homology, Amino Acid ; }, abstract = {An 8.5-kb plasmid encoding genes (leuABCD) involved in leucine biosynthesis and a small plasmid of 1.74 kb of yet unknown function were found in the intracellular symbiont, Buchnera aphidicola, of two divergent aphid species, Thelaxes suberi and Tetraneura caerulescens, respectively. The leuABCD-carrying plasmid (pBTs1) was amplified from total aphid DNA by inverse long PCR, using outwardly oriented oligonucleotide primers specific to leuA. The resulting 8.2-kb PCR fragment as well as the 1.74-kb plasmid (pBTc1) were cloned and sequenced. pBTs1 differed from a previously described B. aphidicola plasmid (pRPE) of the aphid Rhopalosiphum padi by the presence of a small heat shock gene (ibp) and in the order of the leuABCD and repA genes. Comparison of both leucine plasmids to the small plasmid pBTc1 revealed extensive similarity with respect to putative replication functions as well as in the presence of a highly conserved open reading frame that was found to be homologous to Escherichia coli YqhA and Haemophilus influenzae HI0507 and which may encode an integral membrane protein. The three B. aphidicola plasmids most likely evolved from a common ancestral replicon, which in turn may be distantly related to IncFII plasmids. Phylogenetic affiliations of the B. aphidicola strains of the two aphid species were assessed by sequencing of their 16S rRNA genes. Evaluation of the distribution of the leuABCD-encoding plasmids within a phylogenetic framework suggests independent origins for pBTs1 and pRPE from an ancestral replicon resembling pBTc1. The implications for symbiotic essential amino acid biosynthesis and provisioning are discussed.}, }
@article {pmid9216887, year = {1997}, author = {Clark, MA and Baumann, L and Baumann, P}, title = {Buchnera aphidicola (endosymbiont of aphids) contains nuoC(D) genes that encode subunits of NADH dehydrogenase.}, journal = {Current microbiology}, volume = {35}, number = {2}, pages = {122-123}, pmid = {9216887}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Bacteria/*genetics ; Cloning, Molecular ; Molecular Sequence Data ; NADH Dehydrogenase/*genetics ; Open Reading Frames ; Sequence Analysis, DNA ; }, abstract = {A two-kilobase DNA fragment from Buchnera aphidicola, the endosymbiont of aphids, was cloned and sequenced. One open reading frame was detected, coding for a putative protein of 600 amino acids. The N-terminal portion of this protein corresponded to NuoC, while the C-terminal portion corresponded to NuoD. These proteins are constituents of the membrane-associated NADH dehydrogenase. Our results suggest that these two proteins are fused in Buchnera aphidicola, a result consistent with their previously postulated spatial association.}, }
@article {pmid9216881, year = {1997}, author = {Clark, MA and Baumann, P}, title = {The (F1F0) ATP synthase of Buchnera aphidicola (endosymbiont of aphids): genetic analysis of the putative ATP operon.}, journal = {Current microbiology}, volume = {35}, number = {2}, pages = {84-89}, doi = {10.1007/s002849900217}, pmid = {9216881}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Bacteria/*genetics ; Base Sequence ; Chloroplasts/genetics ; Chromosome Mapping ; Cloning, Molecular ; Escherichia coli/genetics ; Mitochondria/genetics ; Molecular Sequence Data ; *Operon ; Proton-Translocating ATPases/*genetics ; }, abstract = {Buchnera aphidicola is an intracellular, non-cultivable prokaryotic symbiont of the aphid Schizaphis graminum. A 6.8-kilobase fragment from B. aphidicola was cloned and sequenced and was found to contain genes encoding for proteins of the ATP synthase. The order of the genes, atpBEFHAGDC, is identical to that found inEscherichia coli and many other prokaryotes. This genetic organization is different from that observed in organelles such as mitochondria and chloroplasts, in which the genes are partitioned between the organellar and nuclear genomes. One difference between B. aphidicola and E. coli was the absence of atpI, a gene of unknown function, which in E. coli precedes atpB. As is the case of many other prokaryotes, atpBEFHAGDC appears to constitute a single transcription unit. The detection in B. aphidicola of the genes encoding the ATP synthase as well as past observations indicating that this organism is capable of respiration are consistent with the utilization byB. aphidicola of a proton gradient for the generation of ATP.}, }
@article {pmid9309164, year = {1997}, author = {Martin, W and Schnarrenberger, C}, title = {The evolution of the Calvin cycle from prokaryotic to eukaryotic chromosomes: a case study of functional redundancy in ancient pathways through endosymbiosis.}, journal = {Current genetics}, volume = {32}, number = {1}, pages = {1-18}, doi = {10.1007/s002940050241}, pmid = {9309164}, issn = {0172-8083}, mesh = {*Biological Evolution ; Chloroplasts/*enzymology ; Genes, Plant ; Photosynthesis/*genetics ; Plants/enzymology ; Symbiosis/*physiology ; }, abstract = {The evolutionary histories of the 12 enzymes that catalyze the reactions of the Calvin cycle in higher-plant chloroplasts are summarized. They are shown to be encoded by a mixture of nuclear genes of cyanobacterial and proteobacterial origin. Moreover, where cytosolic isoforms of these enzymes are found they are almost invariably encoded by genes of clearly endosymbiont origin. We infer that endosymbiosis resulted in functional redundancy that was eliminated through differential gene loss, with intruding eubacterial genes repeatedly replacing pre-existing nuclear counterparts to which they were either functionally or structurally homologous. Our findings fail to support the 'product-specificity corollary', which predicts re-targeting of nuclear-encoded gene products to the organelle from whose genome they originated. Rather it would appear that the enzymes of central carbohydrate metabolism have evolved novel targeting possibilities regardless of their origins. Our findings suggest a new hypothesis to explain organelle genome persistence, based on the testable idea that some organelle-encoded gene products might be toxic when present in the cytosol or other inappropriate cellular compartments.}, }
@article {pmid9296262, year = {1997}, author = {Baumann, P and Moran, NA}, title = {Non-cultivable microorganisms from symbiotic associations of insects and other hosts.}, journal = {Antonie van Leeuwenhoek}, volume = {72}, number = {1}, pages = {39-48}, doi = {10.1023/a:1000239108771}, pmid = {9296262}, issn = {0003-6072}, mesh = {Animals ; Bacteria/*classification ; Insecta/*microbiology ; Phylogeny ; *Symbiosis ; }, abstract = {Many symbiotic associations involve microorganisms which cannot be cultivated on laboratory media. These organisms remained little known until the recent advent of methods of recombinant DNA analysis and molecular phylogenetics. Applications of these methods to endosymbionts have resulted in substantial new insights concerning the genetics and evolution of these organisms. This communication provides a listing of recently studied associations involving non-cultivable symbionts. The associations involve a diverse set of host taxa and a wide range of effects, both favorable and deleterious, on host biology. Among beneficial endosymbionts, a variety of nutritional interactions have been documented. One type of association has been demonstrated for a number of animal hosts, namely endosymbioses that result from a single infection of an ancestral host by a prokaryote. In these associations, endosymbionts are transmitted maternally and are not exchanged between host lineages, resulting in a long-term pattern of codiversification of hosts and endosymbionts. The association between aphids and non-cultivable prokaryotic endosymbionts is a well studied example of such a symbiosis.}, }
@article {pmid9225445, year = {1997}, author = {Chesnick, JM and Kooistra, WH and Wellbrock, U and Medlin, LK}, title = {Ribosomal RNA analysis indicates a benthic pennate diatom ancestry for the endosymbionts of the dinoflagellates Peridinium foliaceum and Peridinium balticum (Pyrrhophyta).}, journal = {The Journal of eukaryotic microbiology}, volume = {44}, number = {4}, pages = {314-320}, doi = {10.1111/j.1550-7408.1997.tb05672.x}, pmid = {9225445}, issn = {1066-5234}, mesh = {Animals ; Base Sequence ; Diatoms/*genetics/physiology ; Dinoflagellida/*physiology ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Ribosomal/*analysis ; *Symbiosis ; }, abstract = {The establishment of chloroplasts as cellular organelles in the dinoflagellate, heterokont (stramenopile), haptophyte, and cryptophyte algae is widely accepted to have been the result of secondary endosymbiotic events, that is, the uptake of a photosynthetic eukaryote by a phagotrophic eukaryote. However, the circumstances that promote such associations between two phylogenetically distinct organisms and result in the integration of their genomes to form a single functional photosynthetic cell is unclear. The dinoflagellates Peridinium foliaceum and Peridinium balticum are unusual in that each contains a membrane-bound eukaryotic heterokont endosymbiont. These symbioses have been interpreted, through data derived from ultrastructural and biochemical investigations, to represent an intermediate stage of secondary endosymbiotic chloroplast acquisition. In this study we have examined the phylogenetic origin of the P. foliaceum and P. balticum heterokont endosymbionts through analysis of their nuclear small subunit ribosomal RNA genes. Our analyses clearly demonstrate both endosymbionts are pennate diatoms belonging to the family Bacillariaceae. Since members of the Bacillariaceae are usually benthic, living on shallow marine sediments, the manner in which establishment of a symbiosis between a planktonic flagellated dinoflagellate and a bottom-dwelling diatom is discussed. In particular, specific environmentally-associated life strategy stages of the host and symbiont, coupled with diatom food preferences by the dinoflagellate, may have been vital to the formation of this association.}, }
@article {pmid9204569, year = {1997}, author = {Pawlowski, K and Twigg, P and Dobritsa, S and Guan, C and Mullin, BC}, title = {A nodule-specific gene family from Alnus glutinosa encodes glycine- and histidine-rich proteins expressed in the early stages of actinorhizal nodule development.}, journal = {Molecular plant-microbe interactions : MPMI}, volume = {10}, number = {5}, pages = {656-664}, doi = {10.1094/MPMI.1997.10.5.656}, pmid = {9204569}, issn = {0894-0282}, mesh = {Actinomycetales/growth &amp; development/metabolism ; Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; DNA, Complementary/genetics ; DNA, Plant/genetics ; Escherichia coli/genetics ; Gene Expression Regulation, Developmental ; Gene Expression Regulation, Plant ; *Genes, Plant ; In Situ Hybridization ; Molecular Sequence Data ; *Multigene Family ; Plant Development ; Plant Proteins/genetics ; Plants/*genetics/microbiology ; Protein Sorting Signals/genetics ; Proteins/genetics ; RNA, Messenger/genetics/metabolism ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {Two cDNAs representing different members (agNt84 and ag164) of a gene family encoding glycine- and histidine-rich proteins have been isolated from cDNA libraries from Alnus glutinosa root nodules. Expression of the corresponding genes could only be detected in nodules. With in situ hybridization, the expression in nodules was found to occur in young, infected cells of the prefixation zone (zone 2). The encoded proteins contain putative signal peptides for targeting to the endomembrane system, sharing sequence similarity with signal peptides from plant glycine-rich proteins, among them nodulin 24, a nodule-specific protein from soybean. This similarity suggests that, analogous to nodulin-24, proteins encoded by agNt84/ag164 may be located at the interface between the host plant membrane and the matrix surrounding the endosymbiont. The 3' untranslated regions of the cDNAs contain unusual poly(AT)n stretches that may play a role in the regulation of RNA stability. The protein encoded by agNt84 cDNA was expressed in Escherichia coli as a fusion with maltose-binding protein, and was shown to have the ability to bind to a nickel-chelating resin, indicating that it may function as a metal-binding protein.}, }
@article {pmid9241987, year = {1997}, author = {Chung, DI and Kong, HH and Kim, TH and Hwang, MY and Yu, HS and Yun, HC and Seol, SY}, title = {[Bacterial endosymbiosis within the cytoplasm of Acanthamoeba lugdunensis isolated from a contact lens storage case].}, journal = {The Korean journal of parasitology}, volume = {35}, number = {2}, pages = {127-133}, doi = {10.3347/kjp.1997.35.2.127}, pmid = {9241987}, issn = {0023-4001}, mesh = {Acanthamoeba/cytology/*microbiology ; Animals ; Bacteria/*isolation &amp; purification ; Colony Count, Microbial ; *Contact Lenses ; Cytoplasm/microbiology ; *Symbiosis ; }, abstract = {Transmission electron microscopy of an Acanthamoeba isolate (KA/L5) from a contact lens case revealed bacterial endosymbionts within cytoplasm of the amoebae. The Acanthamoeba isolate belonged to the morphological group II. Based on the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) of 18S ribosomal RNA coding DNA (rDNA), the isolate was identified as A. lugdunensis. Strain typing by isoenzyme analysis using isoelectric focusing (IEF) and mitochondrial (Mt) DNA RFLP revealed that the isolate was closely related with KA/L1, the most predominant type of isolates from contact lens storage cases, KA/E2, a clinical isolate, KA/W4, previously reported to host endosymbionts, and L3a strains of A. lugdunensis. The endosymbionts were similar to those of KA/W4 in aspects that they were randomly distributed in both trophozoites and cysts, and were rod-shaped bacteria measuring approximately 1.38 x 0.50 microns. But the number of endosymbionts per amoeba was significantly lower than that of KA/W4. They were neither limited by phagosomal membranes nor included in lacunaelike structure.}, }
@article {pmid9218791, year = {1997}, author = {Bradley, PJ and Lahti, CJ and Plümper, E and Johnson, PJ}, title = {Targeting and translocation of proteins into the hydrogenosome of the protist Trichomonas: similarities with mitochondrial protein import.}, journal = {The EMBO journal}, volume = {16}, number = {12}, pages = {3484-3493}, pmid = {9218791}, issn = {0261-4189}, support = {AI07323/AI/NIAID NIH HHS/United States ; }, mesh = {Adenosine Triphosphate/metabolism ; Alkylating Agents/pharmacology ; Animals ; Biological Transport ; Carbonyl Cyanide m-Chlorophenyl Hydrazone/pharmacology ; Ethylmaleimide/pharmacology ; Ferredoxins/metabolism ; Ionophores/pharmacology ; Leucine ; Mitochondria/metabolism ; Mutagenesis, Site-Directed ; Protein Precursors/metabolism ; Protein Processing, Post-Translational ; Protozoan Proteins/*metabolism ; Temperature ; Trichomonas/drug effects/*metabolism ; }, abstract = {Trichomonads are early-diverging eukaryotes that lack both mitochondria and peroxisomes. They do contain a double membrane-bound organelle, called the hydrogenosome, that metabolizes pyruvate and produces ATP. To address the origin and biological nature of hydrogenosomes, we have established an in vitro protein import assay. Using purified hydrogenosomes and radiolabeled hydrogenosomal precursor ferredoxin (pFd), we demonstrate that protein import requires intact organelles, ATP and N-ethylmaleimide-sensitive cytosolic factors. Protein import is also affected by high concentrations of the protonophore, m-chlorophenylhydrazone (CCCP). Binding and translocation of pFd into hydrogenosomes requires the presence of an eight amino acid N-terminal presequence that is similar to presequences found on all examined hydrogenosomal proteins. Upon import, pFd is processed to a size consistent with cleavage of the presequence. Mutation of a conserved leucine at position 2 in the presequence to a glycine disrupts import of pFd into the organelle. Interestingly, a comparison of hydrogenosomal and mitochondrial protein presequences reveals striking similarities. These data indicate that mechanisms underlying protein targeting and biogenesis of hydrogenosomes and mitochondria are similar, consistent with the notion that these two organelles arose from a common endosymbiont.}, }
@article {pmid9168110, year = {1997}, author = {Lang, BF and Burger, G and O'Kelly, CJ and Cedergren, R and Golding, GB and Lemieux, C and Sankoff, D and Turmel, M and Gray, MW}, title = {An ancestral mitochondrial DNA resembling a eubacterial genome in miniature.}, journal = {Nature}, volume = {387}, number = {6632}, pages = {493-497}, doi = {10.1038/387493a0}, pmid = {9168110}, issn = {0028-0836}, mesh = {Animals ; Base Sequence ; DNA, Mitochondrial/*genetics ; DNA, Protozoan/*genetics ; Eukaryota/*genetics ; Evolution, Molecular ; Genome, Bacterial ; Gram-Negative Bacteria/*genetics ; Molecular Sequence Data ; Nucleic Acid Conformation ; Protozoan Proteins/genetics ; RNA, Protozoan ; RNA, Transfer/genetics ; }, abstract = {Mitochondria, organelles specialized in energy conservation reactions in eukaryotic cells, have evolved from eubacteria-like endosymbionts whose closest known relatives are the rickettsial group of alpha-proteobacteria. Because characterized mitochondrial genomes vary markedly in structure, it has been impossible to infer from them the initial form of the proto-mitochondrial genome. This would require the identification of minimally derived mitochondrial DNAs that better reflect the ancestral state. Here we describe such a primitive mitochondrial genome, in the freshwater protozoon Reclinomonas americana. This protist displays ultrastructural characteristics that ally it with the retortamonads, a protozoan group that lacks mitochondria. R. americana mtDNA (69,034 base pairs) contains the largest collection of genes (97) so far identified in any mtDNA, including genes for 5S ribosomal RNA, the RNA component of RNase P, and at least 18 proteins not previously known to be encoded in mitochondria. Most surprising are four genes specifying a multisubunit, eubacterial-type RNA polymerase. Features of gene content together with eubacterial characteristics of genome organization and expression not found before in mitochondrial genomes indicate that R. americana mtDNA more closely resembles the ancestral proto-mitochondrial genome than any other mtDNA investigated to date.}, }
@article {pmid9175861, year = {1997}, author = {Schneider, R and Brors, B and Massow, M and Weiss, H}, title = {Mitochondrial fatty acid synthesis: a relic of endosymbiontic origin and a specialized means for respiration.}, journal = {FEBS letters}, volume = {407}, number = {3}, pages = {249-252}, doi = {10.1016/s0014-5793(97)00360-8}, pmid = {9175861}, issn = {0014-5793}, mesh = {3-Oxoacyl-(Acyl-Carrier-Protein) Synthase/genetics/metabolism ; Acyl Carrier Protein/genetics/metabolism ; Animals ; Electron Transport Complex I ; Fatty Acids/*biosynthesis ; Humans ; Mitochondria/genetics/*metabolism ; Molecular Sequence Data ; NADH Dehydrogenase/metabolism ; NADH, NADPH Oxidoreductases/metabolism ; Oxygen Consumption ; Phospholipids/metabolism ; Phylogeny ; Symbiosis ; }, abstract = {Genes that encode mitochondrial homologues to the bacterial enzymes of fatty acid synthesis were found in various eukaryotic species. Inactivation of these genes leads to a disturbed mitochondrial respiration and an increase in mitochondrial lysophospholipids. We postulate that there is a mitochondrial biosynthetic system providing fatty acids for phospholipid repair. The mitochondrial acyl carrier protein may also play another role, supporting the formation of the respiratory NADH:ubiquinone oxidoreductase.}, }
@article {pmid9162115, year = {1997}, author = {Plaumann, M and Pelzer-Reith, B and Martin, WF and Schnarrenberger, C}, title = {Multiple recruitment of class-I aldolase to chloroplasts and eubacterial origin of eukaryotic class-II aldolases revealed by cDNAs from Euglena gracilis.}, journal = {Current genetics}, volume = {31}, number = {5}, pages = {430-438}, doi = {10.1007/s002940050226}, pmid = {9162115}, issn = {0172-8083}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Cell Nucleus/genetics ; Chloroplasts/enzymology/*genetics ; DNA, Complementary/*genetics/isolation &amp; purification ; DNA, Protozoan/*genetics/isolation &amp; purification ; Euglena gracilis/enzymology/*genetics ; Eukaryotic Cells/enzymology ; Fructose-Bisphosphate Aldolase/*genetics ; Gene Transfer Techniques ; Genetic Code ; Humans ; Isoenzymes/*genetics ; Molecular Sequence Data ; Prokaryotic Cells/enzymology ; Trypanosoma/enzymology/genetics ; }, abstract = {The photosynthetic protist Euglena gracilis is one of few organisms known to possess both class-I and class-II fructose-1,6-bisphosphate aldolases (FBA). We have isolated cDNA clones encoding the precursor of chloroplast class-I FBA and cytosolic class-II FBA from Euglena. Chloroplast class-I FBA is encoded as a single subunit rather than as a polyprotein, its deduced transit peptide of 139 amino acids possesses structural motifs neccessary for precursor import across Euglena's three outer chloroplast membranes. Evolutionary analyses reveal that the class-I FBA of Euglena was recruited to the chloroplast independently from the chloroplast class-I FBA of chlorophytes and may derive from the cytosolic homologue of the secondary chlorophytic endosymbiont. Two distinct subfamilies of class-II FBA genes are shown to exist in eubacteria, which can be traced to an ancient gene duplication which occurred in the common ancestor of contemporary gram-positive and proteobacterial lineages. Subsequent duplications involving eubacterial class-II FBA genes resulted in functional specialization of the encoded products for substrates other than fructose-1,6-bisphosphate. Class-II FBA genes of Euglena and ascomycetes are shown to be of eubacterial origin, having been acquired via endosymbiotic gene transfer, probably from the antecedants of mitochondria. The data provide evidence for the chimaeric nature of eukaryotic genomes.}, }
@article {pmid9143108, year = {1997}, author = {Burnett, WJ and McKenzie, JD}, title = {Subcuticular bacteria from the brittle star Ophiactis balli (Echinodermata: Ophiuroidea) represent a new lineage of extracellular marine symbionts in the alpha subdivision of the class Proteobacteria.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {5}, pages = {1721-1724}, pmid = {9143108}, issn = {0099-2240}, mesh = {Animals ; Bacteria/*classification/*genetics ; DNA Primers/genetics ; Echinodermata/*microbiology ; Molecular Sequence Data ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA ; Symbiosis ; Water Microbiology ; }, abstract = {Many species of echinoderms, in all five extant classes, contain subcuticular bacterial symbionts (SCB). The role of these extracellular symbionts and the nature of the relationship remain unclear. We have sequenced 16S rRNA genes from symbionts to determine their phylogenetic affinities. Symbionts of an ophiuroid, Ophiactis balli, appear closely related to bacteria within the alpha group of the class Proteobacteria, including intracellular endosymbionts and pathogens. SCB are clearly of separate origin from other documented major groups of marine symbiotic bacteria.}, }
@article {pmid9099582, year = {1997}, author = {Aksoy, S and Chen, X and Hypsa, V}, title = {Phylogeny and potential transmission routes of midgut-associated endosymbionts of tsetse (Diptera:Glossinidae).}, journal = {Insect molecular biology}, volume = {6}, number = {2}, pages = {183-190}, doi = {10.1111/j.1365-2583.1997.tb00086.x}, pmid = {9099582}, issn = {0962-1075}, support = {AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification/*genetics ; Base Sequence ; DNA ; Digestive System/microbiology ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Many tsetse species (Diptera: Glossinidae) harbour two morphologically different intracellular endosymbiotic microorganisms associated with gut tissue: primary (P) and secondary (S) endosymbionts. The P-endosymbionts of tsetse (Wigglesworthia glossinidia) are sequestered in specialized epithelial cells, bacteriocytes, which form a structure (bacteriome) in the anterior portion of the gut. Phylogenetic characterization of P-endsymbionts from the three subgenera of genus Glossina has shown that these organisms constitute a distinct lineage within the gamma-subdivision of Proteobacteria and have evolved concordantly with their insect host species, suggesting an evolutionarily ancient association for this symbiosis. The S-endosymbiont is a smaller (1-2 micron) gram-negative rod and is harboured in midgut epithelial cells. Its phylogenetic characterization from Glossina morsitans morsitans had shown that it is a member of the family Enterobacteriaceae within the gamma-3 subdivision of the Proteobacteria, closely related to enteric bacteria. Some tsetse species harbour a third bacterium in their reproductive tissue, which was shown phylogenetically to belong to to the Wolbachia pipientis assemblage of microorganisms. Here, we show that S-endosymbionts from five tsetse species, representing all three subgenera, form a cluster of closely related microorganisms, based on their almost identical 16S rRNA gene sequences. The high similarity provides strong evidence of recent independent acquisition of S-endosymbionts by individual tsetse species, unlike Wigglesworthia which displays concordant evolution with host insect species. A PCR-based assay and restriction fragment length polymorphism (RFLP) analysis was developed to localize the S-endosymbionts and Wigglesworthia in ovary, egg, milk-gland and spermatheca tissues in order to investigate the potential routes for the vertical transmission of these symbionts to the intrauterine larvae. Only S-endosymbionts were found to infect milk gland tissue, suggesting that milk gland secretions represent a route of transmission for these symbionts into the developing larva. The ovary tissue was found to harbour only Wolbachia, confirming its transovarial transmission, whereas the mode of transmission of Wigglesworthia remains unknown.}, }
@article {pmid9145396, year = {1997}, author = {Deming, JW and Reysenbach, AL and Macko, SA and Smith, CR}, title = {Evidence for the microbial basis of a chemoautotrophic invertebrate community at a whale fall on the deep seafloor: bone-colonizing bacteria and invertebrate endosymbionts.}, journal = {Microscopy research and technique}, volume = {37}, number = {2}, pages = {162-170}, doi = {10.1002/(SICI)1097-0029(19970415)37:2&lt;162::AID-JEMT4&gt;3.0.CO;2-Q}, pmid = {9145396}, issn = {1059-910X}, mesh = {Animals ; Bacteria/*ultrastructure ; Bivalvia/microbiology ; Bone and Bones/*microbiology ; Microscopy, Electron ; *Water Microbiology ; Whales/*microbiology ; }, abstract = {To explore the microbial basis for a remarkable macrofaunal community at the site of a whale skeleton on the seafloor of the Santa Catalina Basin, we obtained samples of whale bone, bone-colonizing invertebrates, microbial mats, and the dominant fauna in the adjacent sulfide-rich sediments during Alvin expeditions in 1988 and 1991. Invertebrate tissues were examined by transmission electron microscopy (TEM) and mats and bone-penetrating bacteria by epifluorescence microscopy (EM). Tissues from the dominant bivalve Vesicomya c.f. gigas, the mytilid mussel Idasola washingtonia, and selected gastropods and limpets were also assayed chemically for enzymes diagnostic of sulfur- and methane-based chemoautotrophy and for stable carbon isotopic composition. Results of all analyses were consistent with dominant sulfur-based endosymbioses in the clam and mussel (the first record of endosymbiosis in the genus Idasola) and the general absence of methane symbioses at the site, strengthening the analogy of the whale-skeleton faunal community to those known from distant Pacific hydrothermal vent sites. Examples of minor endosymbionts, either nitrifying or methanotrophic cells according to internal membrane structures by TEM, raised the possibility of a supplemental mode of nutrition to the clam, or means to remove ammonia in the gill tissue, in the event of significant changes in the chemical environment.}, }
@article {pmid9145497, year = {1997}, author = {Distel, DL and Roberts, SJ}, title = {Bacterial endosymbionts in the gills of the deep-sea wood-boring bivalves Xylophaga atlantica and Xylophaga washingtona.}, journal = {The Biological bulletin}, volume = {192}, number = {2}, pages = {253-261}, doi = {10.2307/1542719}, pmid = {9145497}, issn = {0006-3185}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Gills/anatomy &amp; histology/*microbiology ; Mollusca/anatomy &amp; histology/*microbiology ; Symbiosis/*physiology ; }, abstract = {Bacterial endosymbionts found in gill tissues in several bivalve families convert otherwise unavailable energy sources (sulfide, methane, or cellulose) to forms readily metabolized by their hosts. We investigated the existence of such a symbiosis in two species of Xylophaga (family Pholadidae). The genus Xylophaga includes opportunistic species that are the predominant colonizers of wood at depths greater than 150 m. It has been hypothesized that, like their shallow-water counterparts the shipworms (family Teredinidae), species of Xylophaga utilize wood for nutrition. Results from transmission and scanning electron microscopy of X. atlantica and X. washingtona clearly demonstrate the presence of endosymbionts that resemble the shipworm endosymbionts both morphologically and in their anatomical location within the gills. Xylophaga and the teredinids both have a caecum packed with wood chips but lack the dense populations of microorganisms associated with cellulose digestion in termites or ruminants. These observations suggest that Xylophaga has evolved a symbiotic solution to wood digestion similar to that seen in shipworms. Hence, the Xylophaga symbiosis suggests a mechanism for the conversion of terrestrially derived cellulosic carbon from wood into animal biomass in the deep sea.}, }
@article {pmid9141708, year = {1997}, author = {Bowman, JP and McCammon, SA and Skerrat, JH}, title = {Methylosphaera hansonii gen. nov., sp. nov., a psychrophilic, group I methanotroph from Antarctic marine-salinity, meromictic lakes.}, journal = {Microbiology (Reading, England)}, volume = {143 (Pt 4)}, number = {}, pages = {1451-1459}, doi = {10.1099/00221287-143-4-1451}, pmid = {9141708}, issn = {1350-0872}, mesh = {Antarctic Regions ; Bacterial Typing Techniques ; DNA, Ribosomal/genetics ; Evolution, Molecular ; Fatty Acids/analysis ; *Marine Biology ; Methylococcaceae/classification/genetics/*isolation &amp; purification ; Molecular Sequence Data ; Phenotype ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Water Microbiology ; }, abstract = {Methanotrophic bacteria were enumerated and isolated from the chemocline and surface sediments of marine-salinity Antarctic meromictic lakes located in the Vestfold Hills, Antarctica (68 degrees S 78 degrees E). Most probable number (MPN) analysis indicated that at the chemocline of Ace Lake the methanotroph population made up only a small proportion of the total microbial population and was sharply stratified, with higher populations detected in the surface sediments collected at the edge of Ace Lake and Burton Lake. Methanotrophs were not detected in Pendant Lake. Only a single phenotypic group of methanotrophs was successfully enriched, enumerated and isolated into pure culture from the lake samples. Strains of this group were non-motile, coccoidal in morphology, did not form resting cells, reproduced by constriction, and required seawater for growth. The strains were also psychrophilic, with optimal growth occurring at 10-13 degrees C and maximum growth temperatures of 16-21 degrees C. The ribulose monophosphate pathway but not the serine pathway for incorporation of C1 compounds was detectable in the strains. The guanine plus cytosine (G + C) content of the genomic DNA was 43-46 mol%. Whole-cell fatty acid analysis indicated that 16:1 omega 8c (37-41%), 16:1 omega 6c (17-19%), 16:1 omega 7c (15-19%) and 16:0 (14-15%) were the major fatty acids in the strains. 16s rDNA sequence analysis revealed that the strains form a distinct line of descent in the family Methylococcaceae (group I methanotrophs), with the closest relative being the Louisiana Slope methanotrophic mytilid endosymbiont (91.8-92.3% sequence similarity). On the basis of polyphasic taxonomic characteristics the Antarctic lake isolates represent a novel group I methanotrophic genus with the proposed name Methylosphaera hansonii (type strain ACAM 549).}, }
@article {pmid9127737, year = {1997}, author = {Motta, MC and Soares, MJ and Attias, M and Morgado, J and Lemos, AP and Saad-Nehme, J and Meyer-Fernandes, JR and De Souza, W}, title = {Ultrastructural and biochemical analysis of the relationship of Crithidia deanei with its endosymbiont.}, journal = {European journal of cell biology}, volume = {72}, number = {4}, pages = {370-377}, pmid = {9127737}, issn = {0171-9335}, support = {RR0450/RR/NCRR NIH HHS/United States ; }, mesh = {Adenosine Triphosphatases/metabolism ; Animals ; Crithidia/*enzymology/*ultrastructure ; Electron Transport Complex IV/*metabolism ; *Glycolysis ; Mitochondria/ultrastructure ; Phosphoric Monoester Hydrolases/metabolism ; Succinate Cytochrome c Oxidoreductase/metabolism ; Succinate Dehydrogenase/*metabolism ; Symbiosis/*physiology ; }, abstract = {Some protozoa of the Trypanosomatidae family harbor in their cytoplasm bacterial endosymbionts that provide essential nutrients to and induce morphological alterations in the protozoa. In the present study, a close association between endosymbionts and glycosomes, a peroxisome-like organelle where most of the enzymes of the glycolytic pathway are compartmentalized, was identified by conventional transmission electron microscopy in Crithidia deanei. Such an association was further supported by the cytochemical localization of catalase in the glycosome and also confirmed by 3-D reconstruction of the protozoan. The enzymes cytochrome oxidase and succinate dehydrogenase were detected by ultrastructural cytochemistry. A positive reaction was observed in the protozoan mitochondrion but not in the endosymbiont envelope. Enzymatic assays for succinate cytochrome c reductase reinforced these results, as a low enzymatic activity was detected in an endosymbiont-enriched fraction, while high activity was observed in a purified protozoan mitochondrion fraction. We also demonstrated that a purified symbiont fraction was able to hydrolyze ATP. This activity was Mg+2 dependent, since it was highly stimulated by the presence of physiological concentrations of this ion. Taken together, these observations suggest that no electron transporting system is active in the symbionts of Crithidia deanei and that they might obtain energetic molecules derivated from the protozoan glycosomes.}, }
@article {pmid9096383, year = {1997}, author = {Durvasula, RV and Gumbs, A and Panackal, A and Kruglov, O and Aksoy, S and Merrifield, RB and Richards, FF and Beard, CB}, title = {Prevention of insect-borne disease: an approach using transgenic symbiotic bacteria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {94}, number = {7}, pages = {3274-3278}, pmid = {9096383}, issn = {0027-8424}, support = {AI-08614/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Animals, Genetically Modified ; *Antimicrobial Cationic Peptides ; Chagas Disease/*prevention &amp; control/transmission ; *Insect Vectors ; Peptides/genetics/pharmacology ; Recombinant Proteins/genetics ; Rhodnius/microbiology/*parasitology ; Rhodococcus/*genetics/physiology ; Symbiosis ; Transgenes ; Trypanosoma cruzi/drug effects ; }, abstract = {Expression of molecules with antiparasitic activity by genetically transformed symbiotic bacteria of disease-transmitting insects may serve as a powerful approach to control certain arthropod-borne diseases. The endosymbiont of the Chagas disease vector, Rhodnius prolixus, has been transformed to express cecropin A, a peptide lethal to the parasite, Trypanosoma cruzi. In insects carrying the transformed bacteria, cecropin A expression results in elimination or reduction in number of T. cruzi. A method has been devised to spread the transgenic bacteria to populations of R. prolixus, in a manner that mimics their natural coprophagous route of symbiont acquisition.}, }
@article {pmid9058541, year = {1997}, author = {Chen, DQ and Purcell, AH}, title = {Occurrence and transmission of facultative endosymbionts in aphids.}, journal = {Current microbiology}, volume = {34}, number = {4}, pages = {220-225}, doi = {10.1007/s002849900172}, pmid = {9058541}, issn = {0343-8651}, mesh = {Animals ; Aphids/*microbiology ; California/epidemiology ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae/genetics/*isolation &amp; purification ; Rickettsiaceae Infections/*epidemiology/*transmission ; }, abstract = {The occurrence of a secondary bacterial symbiont (PASS) of pea aphid, Acyrthosiphon pisum (Harris), was detected by polymerase chain reaction (PCR) with specific nucleotide primers based on PASS 16S rDNA nucleotide sequences from over 80% (50/57) of clones of pea aphid collected from widely separated locations in California. PASS was also detected by PCR in both red and green phenotypes of rose aphid,Macrosiphum rosae (L.), but not in six other species of aphids examined, including blue alfalfa aphid (A. kondoi Shinji). The nucleotide sequences of the PCR-amplified, partial 16S rDNAs (1060 bp) from pea aphid and rose aphid were identical and 99.9% similar to the published 16S rDNA of PASS. PASS and a recently described new rickettsia of pea aphid (PAR) were transmitted by needle injection of hemolymph from positive pea aphid clones into negative clones and into blue alfalfa aphids. Both PASS and PAR were maintained in the offspring of some of the injected mother aphids via high rate of maternal transmission.}, }
@article {pmid9037042, year = {1997}, author = {Keeling, PJ and Doolittle, WF}, title = {Evidence that eukaryotic triosephosphate isomerase is of alpha-proteobacterial origin.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {94}, number = {4}, pages = {1270-1275}, pmid = {9037042}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Archaea/classification/enzymology/genetics ; *Cell Lineage ; Chlorobi/classification/enzymology/*genetics ; Cloning, Molecular ; Eukaryotic Cells/classification/*enzymology ; Francisella tularensis/classification/enzymology/genetics ; Gene Transfer Techniques ; Genes, Bacterial ; Gram-Negative Aerobic Bacteria/classification/enzymology/*genetics ; Introns ; Models, Biological ; Molecular Sequence Data ; Phylogeny ; Rhizobium/classification/enzymology/genetics ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Symbiosis ; Triose-Phosphate Isomerase/classification/*genetics ; }, abstract = {We have cloned and sequenced genes for triosephosphate isomerase (TPI) from the gamma-proteobacterium Francisella tularensis, the green non-sulfur bacterium Chloroflexus aurantiacus, and the alpha-proteobacterium Rhizobium etli and used these in phylogenetic analysis with TPI sequences from other members of the Bacteria, Archaea, and Eukarya. These analyses show that eukaryotic TPI genes are most closely related to the homologue from the alpha-proteobacterium and most distantly related to archaebacterial homologues. This relationship suggests that the TPI genes present in modern eukaryotic genomes were derived from an alpha-proteobacterial genome (possibly that of the protomitochondrial endosymbiont) after the divergence of Archaea and Eukarya. Among these eukaryotic genes are some from deeply branching, amitochondrial eukaryotes (namely Giardia), which further suggests that this event took place quite early in eukaryotic evolution.}, }
@article {pmid9082070, year = {1997}, author = {Hatzoglou, E and Sekeris, CE}, title = {The detection of nucleotide sequences with strong similarity to hormone responsive elements in the genome of eubacteria and archaebacteria and their possible relation to similar sequences present in the mitochondrial genome.}, journal = {Journal of theoretical biology}, volume = {184}, number = {3}, pages = {339-344}, doi = {10.1006/jtbi.1996.0285}, pmid = {9082070}, issn = {0022-5193}, mesh = {Animals ; Archaea/*genetics ; Base Sequence ; DNA ; *DNA, Mitochondrial ; *Genome, Bacterial ; Humans ; Mice ; Molecular Sequence Data ; Rats ; Receptors, Cell Surface/*genetics ; Symbiosis ; }, abstract = {To account for the presence of nucleotide sequences in mitochondria with similarity to the Hormone Response Elements (HREs) of the nuclear genomes of man, rat and mouse, the genomes of several procaryotes have been screened for the presence of the sequences AGAACA NNN TGTTCT and GGTACA NNN TGTTCT, which represent perfect palindromic and consensus class I HREs, respectively, and for the sequence AGGTCA NNN TGACCT, which represents class II HRE. In many of the examined procaryotes, eubacteria and archaebacteria, almost perfect palindromic class I HREs and perfect or almost perfect class II half palindromic HREs have been detected in various genes, some of which encode proteins involved in energy metabolism, in replication and in transcription control. These findings support the hypothesis that the similar sequences found in mitochondria, potentially involved in hormonal regulation of respiratory enzyme biosynthesis, were introduced into eucaryotic cell by the procaryotic endosymbionts.}, }
@article {pmid9049027, year = {1997}, author = {Hackstein, JH and Vogels, GD}, title = {Endosymbiotic interactions in anaerobic protozoa.}, journal = {Antonie van Leeuwenhoek}, volume = {71}, number = {1-2}, pages = {151-158}, doi = {10.1023/a:1000154526395}, pmid = {9049027}, issn = {0003-6072}, mesh = {Anaerobiosis ; Animals ; *Bacterial Physiological Phenomena ; Eukaryota/metabolism/*microbiology ; Euryarchaeota/*physiology ; Hydrogen/*metabolism ; Organelles/*metabolism ; *Symbiosis ; }, abstract = {Several aspects of the endosymbiosis of methanogenic archaea with anaerobic protozoa are reviewed. Special attention is played to the role of hydrogenosomes and plastid-like organelles that seem to provide the substrates for the methanogenic endosymbionts. Evidence is presented that hydrogenosomes evolved several times in the various protoctistan taxa. Hydrogenosomes are seemingly different, and their common denominator is the production of hydrogen. The absence of nucleic acids and a protein-synthesizing machinery hampers the analysis of their divergent evolutionary history, and molecular genetic data argue not only for different but even a chimeric origin of the hydrogenosomes.}, }
@article {pmid9046247, year = {1997}, author = {Gilson, PR and McFadden, GI}, title = {Good things in small packages: the tiny genomes of chlorarachniophyte endosymbionts.}, journal = {BioEssays : news and reviews in molecular, cellular and developmental biology}, volume = {19}, number = {2}, pages = {167-173}, doi = {10.1002/bies.950190212}, pmid = {9046247}, issn = {0265-9247}, mesh = {Animals ; Eukaryota/*genetics ; *Genome, Protozoan ; Molecular Sequence Data ; Symbiosis ; }, abstract = {Chlorarachniophytes are amoeboflagellate, marine protists that have acquired photosynthetic capacity by engulfing and retaining a green alga. These green algal endosymbionts are severely reduced, retaining only the chloroplast, nucleus, cytoplasm and plasma membrane. The vestigial nucleus of the endosymbiont, called the nucleomorph, contains only three small linear chromosomes and has a haploid genome size of just 380 kb--the smallest eukaryotic genome known. Initial characterisation of nucleomorph DNA has revealed that all chromosomes are capped with inverted repeats comprising a telomere and a single ribosomal RNA operon. The nucleomorph genome is the quintessence of compactness; average space between genes is a mere 65 bp,- some genes overlap, others are cotranscribed. Intense reductive pressures upon nucleomorph genes have apparently squeezed their spliceosomal-type introns down to only 18, 19 or 20 bases in length. Studies to date indicate the nucleomorph--essentially a stripped-down eukaryotic genome--encodes principally genetic housekeeping functions such as translation, transcription and sing.}, }
@article {pmid9013253, year = {1997}, author = {O'Neill, SL and Pettigrew, MM and Sinkins, SP and Braig, HR and Andreadis, TG and Tesh, RB}, title = {In vitro cultivation of Wolbachia pipientis in an Aedes albopictus cell line.}, journal = {Insect molecular biology}, volume = {6}, number = {1}, pages = {33-39}, doi = {10.1046/j.1365-2583.1997.00157.x}, pmid = {9013253}, issn = {0962-1075}, support = {AI28778/AI/NIAID NIH HHS/United States ; AI34355/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*cytology ; Animals ; Cell Line ; Rickettsiaceae/*growth &amp; development ; }, abstract = {A continuous cell line, Aa23, was established from eggs of a strain of the Asian tiger mosquito, Aedes albopictus, naturally infected with the intracellular symbiont Wolbachia pipientis. The resulting cell line was shown to be persistently infected with the bacterial endosymbiont. Treatment with antibiotics cured the cells of the infection. In the course of establishing this cell line it was noticed that RFLPs in the PCR products of two Wolbachia genes from the parental mosquitoes were fixed in the infected cell line. This indicates that the mosquito host was naturally superinfected with different Wolbachia strains, whereas the infected cell line derived from these mosquitoes only contained one of the original Wolbachia strains. The development of an in vitro culture system for this fastidious microorganism should facilitate molecular analysis of the reproduction distorting phenotypes it induces in natural arthropod hosts.}, }
@article {pmid9037104, year = {1997}, author = {Schmidt-Bleek, K and Heiser, V and Thieck, O and Brennicke, A and Grohmann, L}, title = {The 28.5-kDa iron-sulfur protein of mitochondrial complex I is encoded in the nucleus in plants.}, journal = {Molecular &amp; general genetics : MGG}, volume = {253}, number = {4}, pages = {448-454}, doi = {10.1007/s004380050342}, pmid = {9037104}, issn = {0026-8925}, mesh = {Amino Acid Sequence ; Arabidopsis/chemistry/*genetics ; Base Sequence ; Cell Nucleus/*genetics ; Conserved Sequence ; DNA, Complementary/genetics ; Electron Transport Complex I ; Exons ; Gene Expression ; *Genes, Plant ; Introns ; Iron-Sulfur Proteins/chemistry/*genetics ; Mitochondria/chemistry ; Molecular Sequence Data ; Molecular Weight ; NADH, NADPH Oxidoreductases/chemistry/*genetics ; Plant Proteins/chemistry/genetics ; Solanum tuberosum/chemistry/*genetics ; }, abstract = {The intrinsic 28.5-kDa iron-sulfur protein of complex I in the mitochondrial respiratory chain is encoded in the nucleus in animals and fungi, but specified by a mitochondrial gene in trypanosomes. In plants, the homologous protein is now found to be encoded by a single-copy nuclear gene in Arabidopsis thaliana and by two nuclear genes in potato. The cysteine motifs involved in binding two iron-sulfur clusters are conserved in the plant protein sequences. The locations of the seven introns, with sizes between 60 and 1700 nucleotides, are identical in the A. thaliana and the two potato genes, while their primary sequences diverge considerably. The A + T contents of the intron sequences range between 61% and 73%, as is characteristic for dicot plants, but are in some instances not higher than in the adjacent exons. Here, differences in T content may instead serve to discriminate exons and introns. In potato, both genes are expressed, with the highest levels found in flowers. Sequence similarities between the homologous nuclear and mitochondrial genes indicate that the nuclear forms in animals and plants originate from the endosymbiont genome.}, }
@article {pmid9161007, year = {1997}, author = {Ryan, MT and Naylor, DJ and Høj, PB and Clark, MS and Hoogenraad, NJ}, title = {The role of molecular chaperones in mitochondrial protein import and folding.}, journal = {International review of cytology}, volume = {174}, number = {}, pages = {127-193}, doi = {10.1016/s0074-7696(08)62117-8}, pmid = {9161007}, issn = {0074-7696}, mesh = {Animals ; Autoimmunity ; Biological Transport, Active ; Cytosol/metabolism ; Disease/etiology ; Escherichia coli/metabolism ; Female ; Humans ; Intracellular Membranes/metabolism ; Mitochondria/*metabolism ; Models, Biological ; Molecular Chaperones/genetics/immunology/*metabolism ; Pregnancy ; Protein Folding ; Proteins/chemistry/*metabolism ; Ribosomes/metabolism ; Stress, Physiological/metabolism ; }, abstract = {Molecular chaperones play a critical role in many cellular processes. This review concentrates on their role in targeting of proteins to the mitochondria and the subsequent folding of the imported protein. It also reviews the role of molecular chaperons in protein degradation, a process that not only regulates the turnover of proteins but also eliminates proteins that have folded incorrectly or have aggregated as a result of cell stress. Finally, the role of molecular chaperones, in particular to mitochondrial chaperonins, in disease is reviewed. In support of the endosymbiont theory on the origin of mitochondria, the chaperones of the mitochondrial compartment show a high degree of similarity to bacterial molecular chaperones. Thus, studies of protein folding in bacteria such as Escherichia coli have proved to be instructive in understanding the process in the eukaryotic cell. As in bacteria, the molecular chaperone genes of eukaryotes are activated by a variety of stresses. The regulation of stress genes involved in mitochondrial chaperone function is reviewed and major unsolved questions regarding the regulation, function, and involvement in disease of the molecular chaperones are identified.}, }
@article {pmid9071009, year = {1997}, author = {Liaud, MF and Brandt, U and Scherzinger, M and Cerff, R}, title = {Evolutionary origin of cryptomonad microalgae: two novel chloroplast/cytosol-specific GAPDH genes as potential markers of ancestral endosymbiont and host cell components.}, journal = {Journal of molecular evolution}, volume = {44 Suppl 1}, number = {}, pages = {S28-37}, pmid = {9071009}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; *Biological Evolution ; Chloroplasts/enzymology/*genetics ; Cloning, Molecular ; Cytosol/enzymology ; DNA, Complementary/genetics ; Eukaryota/enzymology/*genetics ; Genetic Markers ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Molecular Sequence Data ; Phylogeny ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {Cryptomonads are complex microalgae which share characteristics of chromophytes (chlorophyll c, extra pair of membranes surrounding the plastids) and rhodophytes (phycobiliproteins). Unlike chromophytes, however, they contain a small nucleus-like organelle, the nucleomorph, in the periplastidial space between the inner and outer plastid membrane pairs. These cellular characteristics led to the suggestion that cryptomonads may have originated via a eukaryote-eukaryote endosymbiosis between a phagotrophic host cell and a unicellular red alga, a hypothesis supported by rRNA phylogenies. Here we characterized cDNAs of the nuclear genes encoding chloroplast and cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPDH) from the two cryptomonads Pyrenomonas salina and Guillardia theta. Our results suggest that in cryptomonads the classic Calvin cycle GAPDH enzyme of cyanobacterial origin, GapAB, is absent and functionally replaced by a photosynthetic GapC enzyme of proteobacterial descent, GapC1. The derived GapC1 precursor contains a typical signal/transit peptide of complex structure and sequence signatures diagnostic for dual cosubstrate specificity with NADP and NAD. In addition to this novel GapC1 gene a cytosol-specific GapC2 gene of glycolytic function has been found in both cryptomonads showing conspicuous sequence similarities to animal GAPDH. The present findings support the hypothesis that the host cell component of cryptomonads may be derived from a phototrophic rather than a organotrophic cell which lost its primary plastid after receiving a secondary one. Hence, cellular compartments of endosymbiotic origin may have been lost or replaced several times in eukaryote cell evolution, while the corresponding endosymbiotic genes (e.g., GapC1) were retained, thereby increasing the chimeric potential of the nuclear genome.}, }
@article {pmid9033017, year = {1997}, author = {Rosenthal, B and Mai, Z and Caplivski, D and Ghosh, S and Meckler, J and Samuelson, J}, title = {A revised endosymbiont hypothesis to explain the bacterial origin of amebic glycolytic and fermentation enzymes.}, journal = {Archives of medical research}, volume = {28 Spec No}, number = {}, pages = {71-72}, pmid = {9033017}, issn = {0188-4409}, mesh = {Animals ; Entamoeba histolytica/enzymology/*genetics ; *Evolution, Molecular ; Fermentation/*genetics ; Giardia lamblia/enzymology/*genetics ; Glycolysis/*genetics ; Symbiosis/*genetics ; }, }
@article {pmid8985385, year = {1997}, author = {Filichkin, SA and Brumfield, S and Filichkin, TP and Young, MJ}, title = {In vitro interactions of the aphid endosymbiotic SymL chaperonin with barley yellow dwarf virus.}, journal = {Journal of virology}, volume = {71}, number = {1}, pages = {569-577}, pmid = {8985385}, issn = {0022-538X}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*metabolism ; Bacterial Proteins/genetics/isolation &amp; purification/*metabolism ; Base Sequence ; Centrifugation, Density Gradient ; Chaperonin 60/genetics ; Chaperonins/genetics/isolation &amp; purification/*metabolism ; DNA ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli ; Immunoblotting ; Luteovirus/*metabolism ; Molecular Sequence Data ; Nitrilotriacetic Acid/analogs &amp; derivatives/chemistry ; Organometallic Compounds/chemistry ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sucrose ; Symbiosis ; }, abstract = {Barley yellow dwarf virus (BYDV)-vector relationships suggest that there are specific interactions between BYDV virions and the aphid's cellular components. However, little is known about vector factors that mediate virion recognition, cellular trafficking, and accumulation within the aphid. Symbionins are molecular chaperonins produced by intracellular endosymbiotic bacteria and are the most abundant proteins found in aphids. To elucidate the potential role of symbionins in BYDV transmission, we have isolated and characterized two new symbionin symL genes encoded by the endosymbionts which are harbored by the BYDV aphid vectors Rhopalosiphum padi and Sitobion avenae. Endosymbiont symL-encoded proteins have extensive homology with the pea aphid SymL and Escherichia coli GroEL chaperonin. Recombinant and native SymL proteins can be assembled into oligomeric complexes which are similar to the GroEL oligomer. R. padi SymL protein demonstrates an in vitro binding affinity for BYDV and its recombinant readthrough polypeptide. In contrast to the R. padi SymL, the closely related GroEL does not exhibit a significant binding affinity either for BYDV or for its recombinant readthrough polypeptide. Comparative sequence analysis between SymL and GroEL was used to identify potential SymL-BYDV binding sites. Affinity binding of SymL to BYDV in vitro suggests a potential involvement of endosymbiotic chaperonins in interactions with virions during their trafficking through the aphid.}, }
@article {pmid8979342, year = {1997}, author = {Krueger, DM and Cavanaugh, CM}, title = {Phylogenetic diversity of bacterial symbionts of Solemya hosts based on comparative sequence analysis of 16S rRNA genes.}, journal = {Applied and environmental microbiology}, volume = {63}, number = {1}, pages = {91-98}, pmid = {8979342}, issn = {0099-2240}, mesh = {Animals ; Bacteria/classification/*genetics/isolation &amp; purification ; Base Sequence ; Bivalvia/*microbiology/ultrastructure ; DNA Probes/genetics ; *Genes, Bacterial ; In Situ Hybridization ; Microscopy, Electron ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/*genetics ; *Symbiosis ; }, abstract = {The bacterial endosymbionts of two species of the bivalve genus Solemya from the Pacific Ocean, Solemya terraeregina and Solemya pusilla, were characterized. Prokaryotic cells resembling gram-negative bacteria were observed in the gills of both host species by transmission electron microscopy. The ultrastructure of the symbiosis in both host species is remarkably similar to that of all previously described Solemya spp. By using sequence data from 16S rRNA, the identity and evolutionary origins of the S. terraeregina and S. pusilla symbionts were also determined. Direct sequencing of PCR-amplified products from host gill DNA with primers specific for Bacteria 16S rRNA genes gave a single, unambiguous sequence for each of the two symbiont species. In situ hybridization with symbiont-specific oligonucleotide probes confirmed that these gene sequences belong to the bacteria residing in the hosts gills. Phylogenetic analyses of the 16S rRNA gene sequences by both distance and parsimony methods identify the S. terraeregina and S. pusilla symbionts as members of the gamma subdivision of the Proteobacteria. In contrast to symbionts of other bivalve families, which appear to be monophyletic, the S. terraeregina and S. pusilla symbionts share a more recent common ancestry with bacteria associating endosymbiotically with bivalves of the superfamily Lucinacea than with other Solemya symbionts (host species S. velum, S. occidentalis, and S. reidi). Overall, the 16S rRNA gene sequence data suggest that the symbionts of Solemya hosts represent at least two distinct bacterial lineages within the gamma-Proteobacteria. While it is increasingly clear that all extant species of Solemya live in symbiosis with specific bacteria, the associations appear to have multiple evolutionary origins.}, }
@article {pmid9097044, year = {1996}, author = {Hassan, AK and Moriya, S and Baumann, P and Yoshikawa, H and Ogasawara, N}, title = {Structure of the dnaA region of the endosymbiont, Buchnera aphidicola, of aphid Schizaphis graminum.}, journal = {DNA research : an international journal for rapid publication of reports on genes and genomes}, volume = {3}, number = {6}, pages = {415-419}, doi = {10.1093/dnares/3.6.415}, pmid = {9097044}, issn = {1340-2838}, mesh = {Animals ; Aphids/*microbiology ; Bacterial Proteins/*genetics ; Base Sequence ; Chaperonin 10/*genetics ; Chaperonin 60/*genetics ; *DNA, Bacterial ; Escherichia coli/genetics ; Evolution, Molecular ; *Genes, Bacterial ; Molecular Sequence Data ; Open Reading Frames ; Operon ; Sequence Alignment ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {Buchnera aphidicola is an intracellular prokaryote (endosymbiont) that lives in the body cavity of the aphid. Phylogenetic studies indicated that it is closely related to Escherichia coli and members of Enterobacteria. The gene order of the region containing the dnaA gene is well conserved in many bacteria. Seven genes of the endosymbiont of the aphid Schizaphis graminum, gyrB, dnaN, dnaA, rpmH, rnpA, yidD, and 60K. were found to be homologous in sequence and relative location to those of E. coli. We have further sequenced the region downstream of the 60K gene to elucidate the boundary of the conserved region, and found that one more gene, thdF, is conserved. The comparison of gene organizations of the dnaA region of the related bacteria supported the close phylogenetic relationship of B. aphidicola to E. coli. In addition, we have identified groES and groEL genes next to the thdF gene. GroEL protein was reported to be expressed at an elevated level in the endosymbionts of aphids, and is considered to play an important role in their association with the aphid host. Comparison of the structure of the groE operon with that of the endosymbiont of the aphid Acyrthosiphon pisum revealed the conservation of a sequence resembling the E. coli consensus heat shock promoter, and this sequence may be responsible for the high expression of the groEL gene in aphid endosymbionts.}, }
@article {pmid9035384, year = {1996}, author = {Kantheti, P and Jayarama, KS and Chandra, HS}, title = {Developmental analysis of a female-specific 16S rRNA gene from mycetome-associated endosymbionts of a mealybug, Planococcus lilacinus.}, journal = {Insect biochemistry and molecular biology}, volume = {26}, number = {10}, pages = {997-1009}, doi = {10.1016/s0965-1748(96)00009-4}, pmid = {9035384}, issn = {0965-1748}, mesh = {Animals ; Base Sequence ; Female ; *Gene Expression Regulation, Developmental ; In Situ Hybridization, Fluorescence ; Insecta/embryology/*genetics/parasitology ; Larva/ultrastructure ; Male ; Microscopy, Electron ; Molecular Sequence Data ; RNA, Messenger/*genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {A clone showing female-specific expression was identified from an embryonic cDNA library of a mealybug, Planococcus lilacinus. In Southern blots this clone (P7) showed hybridization to genomic DNA of females, but not to that of males. However, P7 showed no hybridization to nuclei of either sex, raising the possibility that it was extrachromosomal in origin. In sectioned adult females P7 hybridized to an abdominal organ called the mycetome. The mycetome is formed by mycetocytes, which are polyploid cells originating from the polar bodies and cleavage nuclei that harbour maternally transmitted, intracellular symbionts. Electron microscopy confirmed the presence of symbionts within the mycetocytes. Sequence analysis showed that P7 is a 16S rRNA gene, confirming its prokaryotic origin. P7 transcripts are localized to one pole in young embryos but are found in the pole as well as in the germ band during later stages of development. P7 expression is detectable in young embryos of both sexes but the absence of P7 in third instar and adult males suggests that this gene, and hence the endosymbionts, are subject to sex-specific elimination.}, }
@article {pmid8956286, year = {1996}, author = {Johnson, MJ and Casse, N and Pennec, ML}, title = {Spermatogenesis in the endosymbiont-bearing bivalve Loripes lucinalis (Veneroida: Lucinidae).}, journal = {Molecular reproduction and development}, volume = {45}, number = {4}, pages = {476-484}, doi = {10.1002/(SICI)1098-2795(199612)45:4&lt;476::AID-MRD10&gt;3.0.CO;2-V}, pmid = {8956286}, issn = {1040-452X}, mesh = {Animals ; Bivalvia/*physiology ; Male ; Spermatids/*ultrastructure ; Spermatocytes/*ultrastructure ; Spermatogenesis/*physiology ; Spermatozoa/*ultrastructure ; *Symbiosis ; }, abstract = {In the endosymbiont-bearing bivalve Loripes lucinalis, spermatogenesis is similar to that described for numerous bivalve species and leads to the formation of an aquasperm. The head and midpiece measure 10.5 +/- 1.5 microns in length. The head is made up of a cylindrical nucleus slightly tapered apically and capped by a short conical acrosome. The nucleus lacks both an anterior and posterior nuclear invagination. The acrosome is 1.0 +/- 0.1 micron long and consists of an acrosomal cone containing a diffuse subacrosomal material and an apical electron-lucent vacuole. There is no axial rod. The midpiece is made up of four mitochondrial spheres that surround the distal and proximal centrioles. The base of the distal centriole is joined to the plasmic membrane by the pericentriolar complex made up of nine radial arms. A cytoplasmic collar is observed that sheaths the flagellum as it emerges from the distal centriole. The spermatozoa present in mature acini are grouped into characteristic rings, which may have a nutritive function, with the acrosome oriented toward the centre of these ring formations. Also present within the gonad are somatic cells that seem to play a nutritive role in relation to the germinal cells. These nutritive cells undergo a cycle of development and lysis that corresponds to the spermatogenic cycle of the bivalve. These cells are large and rich in glycogen and lipid inclusions. In-depth examination of nutritive cells and gametes reveals that the male gonad is devoid of microorganisms in either a vegetative or cryptic form, suggesting that a vertical transmission through paternal gonadal inheritance is a very unlikely means of symbiont transmission in L. lucinalis.}, }
@article {pmid8955412, year = {1996}, author = {LeVier, K and Guerinot, ML}, title = {The Bradyrhizobium japonicum fegA gene encodes an iron-regulated outer membrane protein with similarity to hydroxamate-type siderophore receptors.}, journal = {Journal of bacteriology}, volume = {178}, number = {24}, pages = {7265-7275}, pmid = {8955412}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Bacterial Outer Membrane Proteins/*genetics/metabolism ; Base Sequence ; Cloning, Molecular ; Culture Media ; DNA, Bacterial ; *Ferric Compounds ; Gene Expression Regulation, Bacterial ; Gram-Negative Bacteria/metabolism ; *Hydroxamic Acids ; Iron/*pharmacokinetics ; Molecular Sequence Data ; Rabbits ; Receptors, Cell Surface/*genetics/metabolism ; Rhizobiaceae/drug effects/*genetics/metabolism ; Sequence Analysis, DNA ; }, abstract = {Iron is important in the symbiosis between soybean and its nitrogen-fixing endosymbiont Bradyrhizobium japonicum, yet little is known about rhizobial iron acquisition strategies. Analysis of outer membrane proteins (OMPs) from B. japonicum 61A152 identified three iron-regulated OMPs in the size range of several known receptors for Fe(III)-scavenging siderophores. One of the iron-regulated proteins, FegA, was purified and microsequenced, and a reverse genetics approach was used to clone a fegA-containing DNA fragment. Sequencing of this fragment revealed a single open reading frame of 750 amino acids. A putative N-terminal signal sequence of 14 amino acids which would result in a mature protein of 736 amino acids with a molecular mass of 80,851 Da was predicted. FegA shares significant amino acid similarity with several Fe(III)-siderophore receptors from gram-negative bacteria and has greater than 50% amino acid similarity and 33% amino acid identity with two [corrected] bacterial receptors for hydroxamate-type Fe(III)-siderophores. A dendrogram describing total inferred sequence similarity among 36 TonB-dependent OMPs was constructed; FegA grouped with Fe(III)-hydroxamate receptors. The transcriptional start site of fegA was mapped by primer extension analysis, and a putative Fur-binding site was found in the promoter. Primer extension and RNA slot blot analysis demonstrated that fegA was expressed only in cells grown under iron-limiting conditions. This is the first report of the cloning of a gene encoding a putative Fe(III)-siderophore receptor from nitrogen-fixing rhizobia.}, }
@article {pmid8923800, year = {1996}, author = {Baker, A and Kaplan, CP and Pool, MR}, title = {Protein targeting and translocation; a comparative survey.}, journal = {Biological reviews of the Cambridge Philosophical Society}, volume = {71}, number = {4}, pages = {637-702}, doi = {10.1111/j.1469-185x.1996.tb01286.x}, pmid = {8923800}, issn = {1464-7931}, mesh = {Bacteria/genetics/metabolism ; Fungi/genetics/metabolism ; *Gene Targeting ; Protein Folding ; Protein Sorting Signals/genetics ; Proteins/chemistry/*genetics/*metabolism ; }, abstract = {The last few years has seen enormous progress in understanding of protein targeting and translocation across biological membranes. Many of the key molecules involved have been identified, isolated, and the corresponding genes cloned, opening up the way for detailed analysis of the structure and function of these molecular machines. It has become clear that the protein translocation machinery of the endoplasmic reticulum is very closely related to that of bacteria, and probably represents an ancient solution to the problem of how to get a protein across a membrane. One of the thylakoid translocation systems looks as if it will also be very similar, and probably represents a pathway inherited from the ancestral endosymbiont. It is interesting that, so far, there is a perfect correlation between thylakoid proteins which are present in photosynthetic prokaryotes and those which use the sec pathway in chloroplasts; conversely, OE16 and 23 which use the delta pH pathway are not found in cyanobacteria. To date, no Sec-related proteins have been found in mitochondria, although these organelles also arose as a result of endosymbiotic events. However, virtually nothing is known about the insertion of mitochondrially encoded proteins into the inner membrane. Is the inner membrane machinery which translocates cytoplasmically synthesized proteins capable of operating in reverse to export proteins from the matrix, or is there a separate system? Alternatively, do membrane proteins encoded by mitochondrial DNA insert independently of accessory proteins? Unlike nuclear-encoded proteins, proteins encoded by mtDNA are not faced with a choice of membrane and, in principle, could simply partition into the inner membrane. The ancestors of mitochondria almost certainly had a Sec system; has this been lost along with many of the proteins once encoded in the endosymbiont genome, or is there still such a system waiting to be discovered? The answer to this question may also shed light on the controversy concerning the sorting of the inter-membrane space proteins cytochrome c1 and cytochrome b2, as the conservative-sorting hypothesis would predict re-export of matrix intermediates via an ancestral (possibly Sec-type) pathway. Whereas the ER and bacterial systems clearly share homologous proteins, the protein import machineries of mitochondria and chloroplasts appear to be analogous rather than homologous. In both cases, import occurs through contact sites and there are separate translocation complexes in each membrane, however, with the exception of some of the chaperone molecules, the individual protein components do not appear to be related. Their similarities may be a case of convergent rather than divergent evolution, and may reflect what appear to be common requirements for translocation, namely unfolding, a receptor, a pore complex and refolding. There are also important differences. Translocation across the mitochondrial inner membrane is absolutely dependent upon delta psi, but no GTP requirement has been identified. In chloroplasts the reverse is the case. The roles of delta psi and GTP, respectively, remain uncertain, but it is tempting to speculate that they may play a role in regulating the import process, perhaps by controlling the assembly of a functional translocation complex. In the case of peroxisomes, much still remains to be learned. Many genes involved in peroxisome biogenesis have been identified but, in most cases, the biochemical function remains to be elucidated. In this respect, understanding of peroxisome biogenesis is at a similar stage to that of the ER 10 years ago. The coming together of genetic and biochemical approaches, as with the other organelles, should provide many of the answers.}, }
@article {pmid8849689, year = {1996}, author = {Pillen, K and Schondelmaier, J and Jung, C and Herrmann, RG}, title = {Genetic mapping of genes for twelve nuclear-encoded polypeptides associated with the thylakoid membranes in Beta vulgaris L.}, journal = {FEBS letters}, volume = {395}, number = {1}, pages = {58-62}, doi = {10.1016/0014-5793(96)01001-0}, pmid = {8849689}, issn = {0014-5793}, mesh = {Cell Nucleus/*genetics ; *Chloroplasts ; Chromosome Mapping ; DNA, Complementary/genetics ; DNA, Plant ; Gene Dosage ; Genes, Plant/*genetics ; Genetic Linkage ; Intracellular Membranes ; Membrane Proteins/*genetics ; Photosynthetic Reaction Center Complex Proteins/genetics ; Plant Proteins/genetics ; Polymorphism, Restriction Fragment Length ; Spinacia oleracea/genetics ; Vegetables/*genetics ; }, abstract = {Thylakoid membranes of chloroplasts are composed of approx. 75 polypeptide species. Nearly 60% originate in nuclear genes, the remainder in plastid genes. In order to localize representatives of the nuclear-encoded gene complement in a eukaryotic plant genome (sugar beet, Beta vulgaris L.), we have investigated the RFLP patterns of 21 cDNAs from spinach that code for thylakoid proteins or proteins peripherally associated with thylakoid membranes. Differences in gene dosage were noted between both related species. Polymorphism was found for 12 cDNA loci in a segregating sugar beet F2 population. These loci were mapped along with genomic RFLP, isozyme, and morphological markers, and shown to be distributed in six of the nine sugar beet linkage groups. The lack of positional clustering even of genes that encode components of the same supramolecular membrane assembly is commensurate with phylogenetically independent gene translocations from the plastid (endosymbiont), and raises the question of the functional integration of various translocated genes into common signal transduction chains.}, }
@article {pmid8790385, year = {1996}, author = {Bui, ET and Bradley, PJ and Johnson, PJ}, title = {A common evolutionary origin for mitochondria and hydrogenosomes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, number = {18}, pages = {9651-9656}, pmid = {8790385}, issn = {0027-8424}, support = {AI07323/AI/NIAID NIH HHS/United States ; AI27857/AI/NIAID NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; *Biological Evolution ; Chaperonin 10/analysis ; Chaperonin 60/analysis ; Conserved Sequence ; HSP70 Heat-Shock Proteins/analysis ; Hydrogen ; *Mitochondria/chemistry ; Molecular Sequence Data ; *Organelles/chemistry ; Sequence Homology, Amino Acid ; *Trichomonas/chemistry ; }, abstract = {Trichomonads are among the earliest eukaryotes to diverge from the main line of eukaryotic descent. Keeping with their ancient nature, these facultative anaerobic protists lack two "hallmark" organelles found in most eukaryotes: mitochondria and peroxisomes. Trichomonads do, however, contain an unusual organelle involved in carbohydrate metabolism called the hydrogenosome. Like mitochondria, hydrogenosomes are double-membrane bounded organelles that produce ATP using pyruvate as the primary substrate. Hydrogenosomes are, however, markedly different from mitochondria as they lack DNA, cytochromes and the citric acid cycle. Instead, they contain enzymes typically found in anaerobic bacteria and are capable of producing molecular hydrogen. We show here that hydrogenosomes contain heat shock proteins, Hsp70, Hsp60, and Hsp10, with signature sequences that are conserved only in mitochondrial and alpha-Gram-negative purple bacterial Hsps. Biochemical analysis of hydrogenosomal Hsp60 shows that the mature protein isolated from the organelle lacks a short, N-terminal sequence, similar to that observed for most nuclear-encoded mitochondrial matrix proteins. Moreover, phylogenetic analyses of hydrogenosomal Hsp70, Hsp60, and Hsp10 show that these proteins branch within a monophyletic group composed exclusively of mitochondrial homologues. These data establish that mitochondria and hydrogenosomes have a common eubacterial ancestor and imply that the earliest-branching eukaryotes contained the endosymbiont that gave rise to mitochondria in higher eukaryotes.}, }
@article {pmid8795235, year = {1996}, author = {Loy, JK and Dewhirst, FE and Weber, W and Frelier, PF and Garbar, TL and Tasca, SI and Templeton, JW}, title = {Molecular phylogeny and in situ detection of the etiologic agent of necrotizing hepatopancreatitis in shrimp.}, journal = {Applied and environmental microbiology}, volume = {62}, number = {9}, pages = {3439-3445}, pmid = {8795235}, issn = {0099-2240}, mesh = {Animals ; Base Sequence ; Decapoda/*microbiology ; Gram-Negative Bacteria/*isolation &amp; purification ; Hepatitis, Animal/*microbiology ; In Situ Hybridization ; Molecular Sequence Data ; Necrosis ; Pancreatitis/*veterinary ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; }, abstract = {Necrotizing hepatopancreatitis (NHP) is a severe disease of farm-raised Penaeus vannamei that has been associated with mortality losses ranging from 20 to 95%. NHP was first recognized in Texas in 1985 (S. K. Johnson, p. 16, in Handbook of Shrimp Diseases, 1989) and is an economically important disease that has limited the ability to culture shrimp in Texas. The putative cause of NHP is a gram-negative, pleomorphic, intracellular, rickettsia-like bacterium that remains uncultured in part because of the absence of established shrimp cell lines. The inability to culture the NHP bacterium necessitated the use of molecular methods for phylogenetic placement of the NHP bacterium. The gene encoding the 16S rRNA (16S rDNA) of this shrimp pathogen was amplified by PCR, cloned, and sequenced. Sequence analysis of the cloned 16S rDNA indicates that the NHP bacterium is a member of the alpha subclass of the Proteobacteria. Within the alpha subclass, the NHP bacterium is shown to be most closely related to bacterial endosymbionts of protozoa, Caedibacter caryophila and Holospora obtusa. Also, the NHP bacterium is distinct from but related to members of the typhus group (Rickettsia typhi and R. prowazekii) and spotted fever group (R. rickettsii) of the family Rickettsiaceae. Fluorescently labeled oligonucleotide DNA probes that bind to variable regions (V2, V6, and V8) of 16S rRNA of the NHP bacterium were used to detect the bacterium in infected shrimp by in situ hybridization. This technique provided direct visual evidence that the 16S rDNA that was amplified, cloned, and sequenced was derived from the intracellular bacterium that infects the hepatopancreas of farm-raised P. vannamei shrimp.}, }
@article {pmid8805838, year = {1996}, author = {Horner, DS and Hirt, RP and Kilvington, S and Lloyd, D and Embley, TM}, title = {Molecular data suggest an early acquisition of the mitochondrion endosymbiont.}, journal = {Proceedings. Biological sciences}, volume = {263}, number = {1373}, pages = {1053-1059}, doi = {10.1098/rspb.1996.0155}, pmid = {8805838}, issn = {0962-8452}, support = {//Wellcome Trust/United Kingdom ; }, mesh = {Animals ; Evolution, Molecular ; *Mitochondria ; Phylogeny ; Symbiosis ; Trichomonas vaginalis/*physiology/ultrastructure ; }, abstract = {The three deepest branching eucaryotic lineages in small subunit ribosomal RNA phylogenies are the amitochondriate Microspora, Metamonada and Parabasala. They are followed by either the Euglenozoa (e.g. Euglena and Trypanosoma) or the Percolozoa as the first mitochondria-containing eucaryotes. To investigate the hypothesis of an even earlier timing of the mitochondrion endosymbiosis we have amplified a partial cpn-60 coding region from the parabasalid Trichomonas vaginalis and the first such sequence from a percolozoan, Naegleria fowleri. Analysis of predicted protein sequences reveals a high degree of sequence similarity (> or = 40%) with a selection of published bacterial and mitochondrial cpn-60s for both taxa. Both sequences were recovered within a strongly supported monophyletic group, otherwise defined by mitochondrial sequences, which systematically clustered with alpha-proteobacteria. These results provide compelling evidence that the ancestor of T. vaginalis once contained the endosymbiont which gave rise to mitochondria, and suggest that this symbiosis probably occurred before the Trichomonas lineage diverged from the main eukaryote trunk. It also makes feasible the published hypothesis that the Trichomonas hydrogenosome might represent a biochemically modified mitochondrion. Analysis of the N. fowleri cpn-60 did not support the hypothesis that the mitochondrion-containing Percolozoa represent an earlier branch in the cpn-60 tree than Trichomonas or Trypanosoma.}, }
@article {pmid8866472, year = {1996}, author = {Schröder, D and Deppisch, H and Obermayer, M and Krohne, G and Stackebrandt, E and Hôlldobler, B and Goebel, W and Gross, R}, title = {Intracellular endosymbiotic bacteria of Camponotus species (carpenter ants): systematics, evolution and ultrastructural characterization.}, journal = {Molecular microbiology}, volume = {21}, number = {3}, pages = {479-489}, doi = {10.1111/j.1365-2958.1996.tb02557.x}, pmid = {8866472}, issn = {0950-382X}, mesh = {Animals ; Ants/*microbiology ; Biological Evolution ; *DNA, Bacterial ; *DNA, Ribosomal ; Female ; Gram-Negative Bacteria/classification/*genetics/ultrastructure ; In Situ Hybridization ; Ovary/microbiology ; Phylogeny ; Polymerase Chain Reaction ; *RNA, Ribosomal, 16S ; *Symbiosis ; }, abstract = {Intracellular endosymbiotic bacteria inherent to ants of the genus Camponotus were characterized. The bacteria were localized in bacteriocytes, which are specialized cells of both workers and queen ants; these cells are intercalated between epithelial cells of the midgut. The bacteriocytes show a different morphology from the normal epithelial cells and carry a large number of the rod-shaped Gram-negative bacteria free in the cytoplasm. The bacteria were never observed in the neighbouring epithelial cells, but they were found intracellularly in oocytes, strongly indicating a maternal transmission of the bacteria. The 16S DNA encoding rrs loci of the endosymbionts of four species of the genus Camponotus derived either from Germany (C. herculeanus and C. ligniperdus), North America (C. floridanus) or South America (C. rufipes) were cloned after polymerase chain reaction (PCR) amplification using oligonucleotides complementary to all so far known eubacterial rrs sequences. The DNA sequences of the rrs loci of the four endosymbionts were determined, and, using various genus- and species-specific oligonucleotides derived from variable regions in the rrs sequences, the identity of the bacteria present in the bacteriocytes and the ovarian cells was confirmed by PCR and in situ hybridization techniques. Comparison of the 16S DNA sequences with the available database showed the endosymbiotic bacteria to be members of the gamma-subclass of Proteobacteria. They formed a distinct taxonomic group, a sister taxon of the taxons defined by the tsetse fly and aphid endosymbionts. Within the gamma-subclass, the cluster of the ant, tsetse fly and aphid endosymbionts are placed adjacent to the family of Enterobacteriaceae. The evolutionary tree of the ant endosymbionts reflects the systematic classification and geographical distribution of their host insects, indicating an early co-evolution of the symbiotic partners and a vertical transmission of the bacteria.}, }
@article {pmid8799741, year = {1996}, author = {Tsagkarakou, A and Guillemaud, T and Rousset, F and Navajas, M}, title = {Molecular identification of a Wolbachia endosymbiont in a Tetranychus urticae strain (Acari: Tetranychidae).}, journal = {Insect molecular biology}, volume = {5}, number = {3}, pages = {217-221}, doi = {10.1111/j.1365-2583.1996.tb00057.x}, pmid = {8799741}, issn = {0962-1075}, mesh = {Animals ; Bacterial Proteins/*genetics ; Base Sequence ; *Cytoskeletal Proteins ; *DNA, Bacterial ; *DNA, Ribosomal ; Female ; Mites/*microbiology ; Molecular Sequence Data ; Phylogeny ; *RNA, Ribosomal, 16S ; Rickettsiaceae/*genetics ; }, abstract = {Wolbachia, a maternally inherited bacterium, is involved in alterations of arthropod sexuality. Reproductive incompatibilities are often observed in miles, but the existence of this microorganism in their cytoplasm has not yet been demonstrated. We identified the presence of Wolbachia in a strain of the spider mite Tetranychus urticae based on the amplification and sequencing of part of the 16S rDNA and ftsZ genes. In order to establish the phylogenetic relationships between Wolbachia found in T. urticae and in other arthropods, we aligned the resulting sequences with already published ones. For both 16S and ftsZ genes the Wolbachia carried by T. urticae clustered together with Wolbachia found in other arthropods.}, }
@article {pmid8702293, year = {1996}, author = {Bianciotto, V and Bandi, C and Minerdi, D and Sironi, M and Tichy, HV and Bonfante, P}, title = {An obligately endosymbiotic mycorrhizal fungus itself harbors obligately intracellular bacteria.}, journal = {Applied and environmental microbiology}, volume = {62}, number = {8}, pages = {3005-3010}, pmid = {8702293}, issn = {0099-2240}, mesh = {Bacteria/*isolation &amp; purification ; Base Sequence ; Fungi/classification/genetics/*ultrastructure ; Molecular Sequence Data ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Arbuscular-mycorrhizal fungi are obligate endosymbionts that colonize the roots of almost 80% of land plants. This paper describes the employment of a combined morphological and molecular approach to demonstrate that the cytoplasm of the arbuscular-mycorrhizal fungus Gigaspora margarita harbors a further bacterial endosymbiont. Intracytoplasmic bacterium-like organisms (BLOs) were detected ultrastructurally in its spores and germinating and symbiotic mycelia. Morphological observations with a fluorescent stain revealed about 250,000 live bacteria inside each spore. The sequence for the small-subunit rRNA gene obtained for the BLOs from the spores was compared with those for representatives of the eubacterial lineages. Molecular phylogenetic analysis unambiguously showed that the endosymbiont of G. margarita was an rRNA group II pseudomanad (genus Burkholderia). PCR assays with specifically designed oligonucleotides were used to check that the sequence came from the BLOs. Successful amplification was obtained when templates from both the spores and the symbiotic mycelia were used. A band of the expected length was also obtained from spores of a Scutellospora sp. No bands were given by the negative controls. These findings indicate that mycorrhizal systems can include plant, fungal, and bacterial cells.}, }
@article {pmid8755545, year = {1996}, author = {Gilson, PR and McFadden, GI}, title = {The miniaturized nuclear genome of eukaryotic endosymbiont contains genes that overlap, genes that are cotranscribed, and the smallest known spliceosomal introns.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, number = {15}, pages = {7737-7742}, pmid = {8755545}, issn = {0027-8424}, mesh = {Amoeba/classification/*genetics ; Animals ; Base Sequence ; Chlorophyta/classification/*genetics ; Consensus Sequence ; *Conserved Sequence ; Evolution, Molecular ; In Situ Hybridization ; Introns ; Microscopy, Electron ; Molecular Sequence Data ; Open Reading Frames ; Plastids ; Polymerase Chain Reaction ; Protein Biosynthesis ; RNA, Small Nuclear/analysis/*biosynthesis ; Restriction Mapping ; Sequence Homology, Nucleic Acid ; Spliceosomes/ultrastructure ; }, abstract = {Chlorarachniophyte algae contain a complex, multi-membraned chloroplast derived from the endosymbiosis of a eukaryotic alga. The vestigial nucleus of the endosymbiont, called the nucleomorph, contains only three small linear chromosomes with a haploid genome size of 380 kb and is the smallest known eukaryotic genome. Nucleotide sequence data from a subtelomeric fragment of chromosome III were analyzed as a preliminary investigation of the coding capacity of this vestigial genome. Several housekeeping genes including U6 small nuclear RNA (snRNA), ribosomal proteins S4 and S13, a core protein of the spliceosome [small nuclear ribonucleoprotein (snRNP) E], and a cip-like protease (clpP) were identified. Expression of these genes was confirmed by combinations of Northern blot analysis, in situ hybridization, immunocytochemistry, and cDNA analysis. The protein-encoding genes are typically eukaryotic in overall structure and their messenger RNAs are polyadenylylated. A novel feature is the abundance of 18-, 19-, or 20-nucleotide introns; the smallest spliceosomal introns known. Two of the genes, U6 and S13, overlap while another two genes, snRNP E and clpP, are cotranscribed in a single mRNA. The overall gene organization is extraordinarily compact, making the nucleomorph a unique model for eukaryotic genomics.}, }
@article {pmid8755544, year = {1996}, author = {Van de Peer, Y and Rensing, SA and Maier, UG and De Wachter, R}, title = {Substitution rate calibration of small subunit ribosomal RNA identifies chlorarachniophyte endosymbionts as remnants of green algae.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, number = {15}, pages = {7732-7736}, pmid = {8755544}, issn = {0027-8424}, mesh = {Amoeba/classification/*genetics ; Animals ; Chlorophyta/classification/*genetics ; Computer Communication Networks ; Databases, Factual ; Dictyostelium/classification/genetics ; Evolution, Molecular ; Models, Theoretical ; *Phylogeny ; Plastids ; RNA, Ribosomal/*chemistry/genetics ; Symbiosis ; }, abstract = {Chlorarachniophytes are amoeboid algae with chlorophyll a and b containing plastids that are surrounded by four membranes instead of two as in plants and green algae. These extra membranes form important support for the hypothesis that chlorarachniophytes have acquired their plastids by the ingestion of another eukaryotic plastid-containing alga. Chlorarachniophytes also contain a small nucleus-like structure called the nucleomorph situated between the two inner and the two outer membranes surrounding the plastid. This nucleomorph is a remnant of the endosymbiont's nucleus and encodes, among other molecules, small subunit ribosomal RNA. Previous phylogenetic analyses on the basis of this molecule provided unexpected and contradictory evidence for the origin of the chlorarachniophyte endosymbiont. We developed a new method for measuring the substitution rates of the individual nucleotides of small subunit ribosomal RNA. From the resulting substitution rate distribution, we derived an equation that gives a more realistic relationship between sequence dissimilarity and evolutionary distance than equations previously available. Phylogenetic trees constructed on the basis of evolutionary distances computed by this new method clearly situate the chlorarachniophyte nucleomorphs among the green algae. Moreover, this relationship is confirmed by transversion analysis of the Chlorarachnion plastid small subunit ribosomal RNA.}, }
@article {pmid8779569, year = {1996}, author = {Gros, O and Darrasse, A and Durand, P and Frenkiel, L and Mouëza, M}, title = {Environmental transmission of a sulfur-oxidizing bacterial gill endosymbiont in the tropical lucinid bivalve Codakia orbicularis.}, journal = {Applied and environmental microbiology}, volume = {62}, number = {7}, pages = {2324-2330}, pmid = {8779569}, issn = {0099-2240}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification/*metabolism ; Base Sequence ; DNA Primers/genetics ; DNA Probes ; DNA, Bacterial/genetics/isolation &amp; purification ; DNA, Ribosomal/genetics ; Gills/microbiology/ultrastructure ; Microscopy, Electron ; Molecular Sequence Data ; Mollusca/genetics/*microbiology/ultrastructure ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sulfur/*metabolism ; *Symbiosis ; }, abstract = {Codakia orbicularis is a large tropical member of the bivalve mollusk family Lucinidae which inhabits shallow-water sea-grass beds (Thalassia testudinum environment) and harbors sulfur-oxidixing endosymbiotic bacteria within bacteriocytes of its gill filaments. When a C. orbicularis-specific 16S rDNA (DNA encoding rRNA) primer is used with a bacterium-specific 16S rDNA reverse primer in amplifications by PCR, the primer set was unsuccessful in amplifying symbiont DNA targets from ovaries, eggs, veligers, and metamorphosed juveniles (600 microns to 1 mm in shell length) cultivated in sterile sand, whereas successful amplifications were obtained from gill tissue of adult specimens and from metamorphosed juveniles (600 microns to 1 mm in shell length) cultivated in unsterilized sea-grass bed sand. To ascertain the presence of the symbiont target in juveniles, restriction fragment length polymorphism analysis, Southern blotting, and transmission electron microscopy were used. Specific hybridizations and observation of endosymbiotic bacteria in the gills of numerous juveniles cultivated in unsterilized sea-grass bed sand showed that the sulfur-oxidizing endosymbionts of C. orbicularis are environmentally transmitted to the new generation after larval metamorphosis.}, }
@article {pmid8764685, year = {1996}, author = {Chang, NW and Wade, MJ}, title = {An improved microinjection protocol for the transfer of Wolbachia pipientis between infected and uninfected strains of the flour beetle Tribolium confusum.}, journal = {Canadian journal of microbiology}, volume = {42}, number = {7}, pages = {711-714}, doi = {10.1139/m96-097}, pmid = {8764685}, issn = {0008-4166}, support = {GM22523/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Cytoplasm/microbiology ; Female ; Larva/microbiology/physiology ; Male ; Microinjections ; Ovum/microbiology ; Reproduction ; Rickettsiaceae/*physiology ; Tribolium/*microbiology/physiology ; }, abstract = {The lethality of halocarbon and other oils to hatching larvae of the flour beetle Tribolium confusum limits existing microinjection protocols, because postinjection survivorship is only 5.6% of the eggs injected. We report the development of an oil-free protocol that improves survivorship fivefold. We used this protocol to transfect the cytoplasmic endosymbiont Wolbachia pipientis from infected donor eggs to uninfected host eggs and observed reproductive incompatibility in 40% of the surviving, injected eggs. Compared with mock injected controls (35.9% survival) or microinjection of uninfected cytoplasm (32.3% survival), injection of Wolbachia-infected cytoplasm into host eggs significantly reduced egg-to-adult survival (25.1%).}, }
@article {pmid8764482, year = {1996}, author = {Durand, P and Gros, O}, title = {Bacterial host specificity of Lucinacea endosymbionts: interspecific variation in 16S rRNA sequences.}, journal = {FEMS microbiology letters}, volume = {140}, number = {2-3}, pages = {193-198}, doi = {10.1016/0378-1097(96)00178-4}, pmid = {8764482}, issn = {0378-1097}, mesh = {Animals ; Bacteria/classification/*genetics/*isolation &amp; purification ; Bivalvia/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Evolution, Molecular ; Genes, Bacterial ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/*genetics ; Species Specificity ; Symbiosis ; }, abstract = {Three tropical lucinid clams (Codakia orbiculata, Codakia pectinella and Lucina nassula) from a shallow coastal environment have been studied regarding to their thioautotrophic bacterial endosymbionts. The 16S rRNA genes (rDNA) from these three endosymbionts were amplified using PCR. Phylogenetic analysis by distance matrix and parsimony methods always placed the newly examined symbionts within the monophyletic group composed of symbionts of the bivalve superfamily Lucinacea. A same single 16S rRNA sequence was found in C. orbiculata and C. pectinella and was identical to that found in C. orbicularis and Linga pensylvanica, two other lucinids living in the same type of environment. These data indicate that a same symbiont species may be associated with different host species. Lucina nassula host a symbiont with a distinct 16S rDNA sequence, but very closely related to the former.}, }
@article {pmid8660431, year = {1996}, author = {Gehrig, H and Schüssler, A and Kluge, M}, title = {Geosiphon pyriforme, a fungus forming endocytobiosis with Nostoc (cyanobacteria), is an ancestral member of the Glomales: evidence by SSU rRNA analysis.}, journal = {Journal of molecular evolution}, volume = {43}, number = {1}, pages = {71-81}, pmid = {8660431}, issn = {0022-2844}, mesh = {Base Sequence ; Cyanobacteria/*physiology ; DNA Primers ; DNA, Fungal/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Endocytosis ; Fungi/*classification/genetics ; Molecular Sequence Data ; Mucorales/classification/genetics/*physiology ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Fungal/*genetics ; RNA, Ribosomal/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {Geosiphon pyriforme inhabiting the surface of humid soils represents the only known example of endocytobiosis between a fungus (Zygomycotina; macrosymbiont) and cyanobacteria (Nostoc; endosymbiont). In order to elucidate the taxonomical and evolutionary relationship of Geosiphon pyriforme to fungi forming arbuscular mycorrhiza (AM fungi), the small-subunit (SSU) ribosomal RNA genes of Geosiphon pyriforme and Glomus versiforme (Glomales; a typical AM fungus) were analyzed and aligned with SSU rRNA sequences of several Basidiomycetes, Ascomycetes, Chytridiomycetes, and Zygomycetes, together with all AM-fungal (Glomales) sequences published yet. The distinct group of the order Glomales, which includes Geosiphon, does not form a clade with any other group of Zygomycetes. Within the Glomales, two main lineages exist. One includes the families Gigasporaceae and Acaulosporaceae; the other one is represented by the genus Glomus, the members of which are very divergent. Glomus etunicatum and Geosiphon pyriforme both form independent lineages ancestral to the Glomales. The data provided by the present paper confirm clearly that Geosiphon represents a fungus belonging to the Glomales. The question remains still open as to whether or not Geosiphon is to be placed within or outside the genus Glomus, since this genus is probably polyphyletic and not well defined yet. Geosiphon shows the ability of a Glomus-like fungus to form a "primitive" symbiosis with a unicellular photoautotrophic organism, in this case a cyanobacterium, leading to the conclusion that a hypothetical association of a Glomus-like fungus with a green alga as a step during the evolution of the land plants appears probable.}, }
@article {pmid8817452, year = {1996}, author = {Lassy, CW and Karr, TL}, title = {Cytological analysis of fertilization and early embryonic development in incompatible crosses of Drosophila simulans.}, journal = {Mechanisms of development}, volume = {57}, number = {1}, pages = {47-58}, doi = {10.1016/0925-4773(96)00527-8}, pmid = {8817452}, issn = {0925-4773}, mesh = {Animals ; Centrosome/physiology ; Chromosome Aberrations/physiology ; Crosses, Genetic ; Drosophila/*embryology/*microbiology/physiology ; Female ; Fertilization ; Infertility/microbiology ; Male ; Rickettsia ; Sperm Tail/physiology ; }, abstract = {Cytoplasmic incompatibility (CI) is a unique form of male sterility found in numerous insect species that harbor a bacterial endosymbiont Wolbachia. CI is characterized by severe reduction in the progeny produced when infected males are crossed to uninfected females. The reduction in progeny correlates with developmental defects that arise during and immediately following fertilization, suggesting that sperm function is disrupted. To investigate the nature of the cellular defects associated with CI, fertilization and early embryonic development were examined in normal and incompatible crosses of Drosophila simulans using anti-sperm, anti-tubulin and anti-chromatin antibodies. Although pleiotropic, defects associated with CI can be classified into five broad categories: (1) sperm defects in the egg; (2) aberrant morphology of the mitotic apparatus; (3) defects in chromatin structure; (4) proliferation of centrosomes in the absence of nuclear division; and (5) loss of mitotic synchrony. Although mitosis and chromosome behavior are severely disrupted in CI crosses during early development, centrosome duplication and migration appear to continue unabated. The available cytological data suggest that the primary defects observed in incompatible crosses are due to defects in chromosome replication/segregation and in associated centrosome/microtubule-based processes.}, }
@article {pmid8805076, year = {1996}, author = {Hackstadt, T}, title = {The biology of rickettsiae.}, journal = {Infectious agents and disease}, volume = {5}, number = {3}, pages = {127-143}, pmid = {8805076}, issn = {1056-2044}, mesh = {Animals ; Arthropod Vectors ; Humans ; *Rickettsia/pathogenicity/physiology/ultrastructure ; Rickettsia Infections/epidemiology/*parasitology ; Rickettsia prowazekii/pathogenicity ; Rickettsia typhi/pathogenicity ; Rocky Mountain Spotted Fever/epidemiology ; Typhus, Endemic Flea-Borne/epidemiology ; Typhus, Epidemic Louse-Borne/epidemiology ; }, abstract = {Rickettsiae are bacterial obligate intracellular parasites ranging from harmless endosymbionts to the etiologic agents of some of the most devastating diseases known to mankind. Rickettsiae are primarily associated with arthropod vectors in which they may exist commensally and, in most cases, only accidentally infect humans. These fascinating microbes are the prototypical obligate intracellular parasites. Other than being extremely fastidious in their growth requirements, however, rickettsiae are typical gram-negative bacteria. Only a few intracellular parasites multiply within the cytoplasm of eukaryotic cells. In this environment, rickettsiae are provided with a rich source of biosynthetic precursors not normally encountered by free-living bacteria and have evolved a number of unique mechanisms to transport such metabolites as nucleotides and nucleotide sugars. The physiologic basis for their obligate parasitism, however, has remained elusive for > 90 years. Other than the obvious property of replicating inside eukaryotic cells, the molecular mechanisms of cellular damage are ill defined. The typhus-group rickettsiae multiply within host cells to great numbers without profound damage until lysis occurs. In contrast, the spotted fever-group rickettsiae spread rapidly from cell to cell by an actin-based motility. This property, in itself, is not sufficient to cause cell death, because avirulent spotted fever-group rickettsiae also spread by actin-based movement but do not cause lysis of the host cell. Despite the obvious limitations imposed by their obligate intracellular lifestyle and the current lack of methods for genetic manipulation, there are enough interesting biological properties of rickettsiae to offer an attractive area for research.}, }
@article {pmid8637928, year = {1996}, author = {Simon, JC and Martinez-Torres, D and Latorre, A and Moya, A and Hebert, PD}, title = {Molecular characterization of cyclic and obligate parthenogens in the aphid Rhopalosiphum padi (L.).}, journal = {Proceedings. Biological sciences}, volume = {263}, number = {1369}, pages = {481-486}, doi = {10.1098/rspb.1996.0072}, pmid = {8637928}, issn = {0962-8452}, mesh = {Animals ; Aphids/*genetics/*growth &amp; development/microbiology ; Base Sequence ; DNA Primers/genetics ; DNA, Mitochondrial/genetics ; Female ; Genetic Linkage ; Haplotypes/genetics ; Male ; Molecular Sequence Data ; Parthenogenesis/*genetics ; Plasmids/genetics ; Random Amplified Polymorphic DNA Technique ; }, abstract = {Holocyclic clones of the aphid Rhopalosiphum padi (L.) reproduce by cyclic parthenogenesis, whereas anholocyclic individuals are obligate parthenogens. Mitochondrial DNA and (mtDNA) and random amplified polymorphic DNA markers in R. padi as well as plasmid DNA markers of its bacterial endosymbiont, Buchnera aphidicola, were examined to determine the extent of genetic divergence between clones with these differing breeding systems. These analyses revealed that cyclically parthenogenetic lineages possessed differing mtDNA and plasmid haplotypes than most obligately asexual clones. The extent of sequence divergence between the maternally inherited molecules suggest a relatively ancient origin of asexuality. Our work also identified a random amplified polymorphic DNA marker linked to the life-cycle variation in R. padi. This marker not only permits the rapid diagnosis of breeding system but sets the stage for studies to identify the gene(s) controlling this variation in mode of reproduction.}, }
@article {pmid8610134, year = {1996}, author = {Moran, NA}, title = {Accelerated evolution and Muller's rachet in endosymbiotic bacteria.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, number = {7}, pages = {2873-2878}, pmid = {8610134}, issn = {0027-8424}, mesh = {Animals ; Aphids/microbiology ; *Biological Evolution ; Codon ; DNA, Bacterial/*genetics/metabolism ; DNA, Ribosomal/*genetics/metabolism ; Escherichia coli/genetics ; Insecta/classification/*genetics ; Lactobacillus/classification/*genetics ; RNA, Ribosomal, 16S/*genetics ; Salmonella typhimurium/genetics ; Symbiosis ; }, abstract = {Many bacteria live only within animal cells and infect hosts through cytoplasmic inheritance. These endosymbiotic lineages show distinctive population structure, with small population size and effectively no recombination. As a result, endosymbionts are expected to accumulate mildly deleterious mutations. If these constitute a substantial proportion of new mutations, endosymbionts will show (i) faster sequence evolution and (ii) a possible shift in base composition reflecting mutational bias. Analyses of 16S rDNA of five independently derived endosymbiont clades show, in every case, faster evolution in endosymbionts than in free-living relatives. For aphid endosymbionts (genus Buchnera), coding genes exhibit accelerated evolution and unusually low ratios of synonymous to nonsynonymous substitutions compared to ratios for the same genes for enterics. This concentration of the rate increase in nonsynonymous substitutions is expected under the hypothesis of increased fixation of deleterious mutations. Polypeptides for all Buchnera genes analyzed have accumulated amino acids with codon families rich in A+T, supporting the hypothesis that substitutions are deleterious in terms of polypeptide function. These observations are best explained as the result of Muller's ratchet within small asexual populations, combined with mutational bias. In light of this explanation, two observations reported earlier for Buchnera, the apparent loss of a repair gene and the overproduction of a chaperonin, may reflect compensatory evolution. An alternative hypothesis, involving selection on genomic base composition, is contradicted by the observation that the speedup is concentrated at nonsynonymous sites.}, }
@article {pmid8642610, year = {1996}, author = {Rouhbakhsh, D and Lai, CY and von Dohlen, CD and Clark, MA and Baumann, L and Baumann, P and Moran, NA and Voegtlin, DJ}, title = {The tryptophan biosynthetic pathway of aphid endosymbionts (Buchnera): genetics and evolution of plasmid-associated anthranilate synthase (trpEG) within the aphididae.}, journal = {Journal of molecular evolution}, volume = {42}, number = {4}, pages = {414-421}, pmid = {8642610}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Animals ; Anthranilate Synthase/*genetics ; Aphids/*microbiology ; Bacteria/*genetics/metabolism ; Base Sequence ; Biological Evolution ; Conserved Sequence ; Escherichia coli/genetics ; Molecular Sequence Data ; Mutagenesis ; Phylogeny ; Plasmids/genetics ; Replication Origin ; Sequence Homology, Amino Acid ; Symbiosis/*genetics ; Tryptophan/*biosynthesis ; Tryptophan Synthase/genetics ; }, abstract = {The bacterial endosymbionts (Buchnera) from the aphids Rhopalosiphum padi, R. maidis, Schizaphis graminum, and Acyrthosiphon pisum contain the genes for anthranilate synthase (trpEG) on plasmids made up of one or more 3.6-kb units. Anthranilate synthase is the first as well as the rate-limiting enzyme in the tryptophan biosynthetic pathway. The amplification of trpEG on plasmids may result in an increase of enzyme protein and overproduction of this essential amino acid, which is required by the aphid host. The nucleotide sequence of trpEG from endosymbionts of different species of aphids is highly conserved, as is an approximately 500-bp upstream DNA segment which has the characteristics of an origin of replication. Phylogenetic analyses were performed using trpE and trpG from the endosymbionts of these four aphids as well as from the endosymbiont of Schlechtendalia chinensis, in which trpEG occurs on the chromosome. The resulting phylogeny was congruent with trees derived from sequences of two chromosome-located bacterial genes (part of trpB and 16S ribosomal DNA). In turn, trees obtained from plasmid-borne and bacterial chromosome-borne sequences were congruent with the tree resulting from phylogenetic analysis of three aphid mitochondrial regions (portions of the small and large ribosomal DNA subunits, as well as cytochrome oxidase II). Congruence of trees based on genes from host mitochondria and from bacteria adds to previous support for exclusively vertical transmission of the endosymbionts within aphid lineages. Congruence with trees based on plasmid-borne genes supports the origin of the plasmid-borne trpEG from the chromosomal genes of the same lineage and the absence of subsequent plasmid exchange among endosymbionts of different species of aphids.}, }
@article {pmid8605300, year = {1996}, author = {Schmitz, G and Schmidt, M and Feierabend, J}, title = {Characterization of a plastid-specific HSP90 homologue: identification of a cDNA sequence, phylogenetic descendence and analysis of its mRNA and protein expression.}, journal = {Plant molecular biology}, volume = {30}, number = {3}, pages = {479-492}, pmid = {8605300}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; DNA, Plant ; Gene Dosage ; Gene Expression Regulation, Plant ; HSP90 Heat-Shock Proteins/classification/*genetics/isolation &amp; purification ; *Heat-Shock Proteins ; Molecular Sequence Data ; Phylogeny ; Plant Proteins/classification/*genetics/isolation &amp; purification ; Plastids/*genetics ; Secale/classification/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {The isolation of cDNAs is described which encode the complete sequence of a precursor protein for a HSP90 homologue consisting of an N-terminal transit peptide of 5850 Da and a mature protein (cpHSP82) of 82 260 Da, located in the plastids of rye leaves (Secale cereale). Hybridization analysis indicated the presence of a single gene in the DNA of rye and a transcript size of 2.8 kb. A phylogenetic tree constructed on the basis of sequence comparisons for HSP90 homologues from different species and compartments indicated that the plastidic HSP82 from rye was more closely related to an eubacterial protein than to HSP90 homologues of the cytosol or ER from both plants and animals. The results suggest that during chloroplast evolution the gene for cpHSP82 was transferred to the nucleus from a prokaryotic endosymbiont. Immunoblots with specific antibodies and Percoll gradient-purified organelles confirmed the location of cpHSP82 in chloroplasts or non-green plastids. In green rye leaves cpHSP82 was constitutively expressed and equally distributed among tissues of different age. The expression of cpHSP82 was enhanced within 2 h by exposure to 42 degrees C. The cpHSP82 transcript and protein were much more strongly expressed in non-green tissues, such as etiolated, 70S ribosome-deficient 32 degrees C-grown, or herbicide-bleached, than in normal green leaves. Also chromoplasts from the pericarp of tomato fruits contained high levels of a HSP90 polypeptide while a photosynthetic protein, the large subunit of ribulose-1,5-bisphosphate carboxylase was largely degraded during ripening.}, }
@article {pmid8593038, year = {1996}, author = {Lai, CY and Baumann, P and Moran, N}, title = {The endosymbiont (Buchnera sp.) of the aphid Diuraphis noxia contains plasmids consisting of trpEG and tandem repeats of trpEG pseudogenes.}, journal = {Applied and environmental microbiology}, volume = {62}, number = {2}, pages = {332-339}, pmid = {8593038}, issn = {0099-2240}, mesh = {Animals ; Anthranilate Synthase/genetics ; Aphids/*microbiology ; Bacteria/*genetics/metabolism ; Base Sequence ; Biological Evolution ; DNA, Bacterial/genetics ; Genes, Bacterial ; Molecular Sequence Data ; Open Reading Frames ; Plasmids/*genetics ; Promoter Regions, Genetic ; Pseudogenes ; *Repetitive Sequences, Nucleic Acid ; Replication Origin ; Restriction Mapping ; Sequence Homology, Nucleic Acid ; Symbiosis ; Tryptophan/biosynthesis ; }, abstract = {Most aphids are dependent for their survival on prokaryotic endosymbionts assigned to the genus Buchnera. Among the functions of Buchnera species is the synthesis of tryptophan, which is required by the aphid host. In Buchnera species from the aphid Diuraphis noxia, the genes for anthranilate synthase (trpEG) were found on a plasmid which consisted of seven tandem repeats of a 3.2-kb unit and one 2.6-kb unit which differed in containing a 0.6-kb deletion. One of the 3.2-kb units contained open reading frames corresponding to trpEG; the remaining units contained trpEG pseudogenes (psi). The nucleotide sequence upstream of trpE contained a region that has characteristics of an origin of replication (ori). Relative to trpB (a chromosomal gene), there were about two copies of the trpEG-containing plasmid. Comparisons of the nucleotide sequences of the 3.2-kb units containing trpEG and psi trpEG indicated that most changes occurred in a 700-nucleotide segment that included the region upstream of trpE and the portion of this gene coding for the N terminus. The consequence of these changes was the silencing of trpEG by inactivation of the putative promoter region and premature termination of the TrpE peptide. In contrast, the nucleotide sequence of the segment corresponding to ori was conserved in the units containing trpEG and psi trpEG. We offer a number of speculations on the evolutionary pressure in this lineage which resulted in the silencing of most of trpEG while still retaining the regions resembling ori.}, }
@article {pmid8574133, year = {1996}, author = {Clark, MA and Baumann, L and Baumann, P and Rouhbakhsh, D}, title = {Ribosomal protein S1 (RpsA) of Buchnera aphidicola, the endosymbiont of aphids: characterization of the gene and detection of the product.}, journal = {Current microbiology}, volume = {32}, number = {2}, pages = {89-94}, doi = {10.1007/s002849900016}, pmid = {8574133}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Amino Acids/biosynthesis ; Animals ; Aphids/*microbiology ; Bacteria/*genetics/metabolism ; Bacterial Proteins/genetics ; Base Sequence ; Carbohydrate Metabolism ; Chromosome Mapping ; Cloning, Molecular ; DNA Probes/genetics ; DNA, Bacterial/genetics ; DNA-Binding Proteins/genetics ; *Genes, Bacterial ; Molecular Sequence Data ; Recombinant Fusion Proteins/genetics ; Ribosomal Proteins/*genetics/isolation &amp; purification ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {Buchnera aphidicola is a prokaryotic endosymbiont found in specialized cells of the aphid Schizaphis graminum. Many of the previously cloned B. aphidicola genes are preceded by a poor ribosome-binding site. Ribosomal protein S1 (RpsA) allows the translation of messenger RNAs that lack or have a poor ribosome binding site. We have cloned and sequenced a 4.5-kilobase (kb) B. aphidicola DNA fragment containing four open reading frames corresponding to aroA-rpsA-himD-tpiA. The deduced amino acid sequence of B. aphidicola RpsA was 75% identical to that of the Escherichia coli protein. The major difference was in the number of basic amino acids, which were present in higher numbers in B. aphidicola RpsA. Antiserum to E. coli RpsA was prepared and used to detect B. aphidicola RpsA in cell-free extracts of aphids. During the first 12 days of aphid growth there is a slight decrease in the amount of RpsA per unit of aphid weight. The three additional genes found on the 4.5-kb DNA fragment encoded for proteins involved in aromatic amino acid biosynthesis (aroA), DNA bending (himD), and carbohydrate metabolism (tpiA). The presence of these genes in B. aphidicola is additional evidence of its similarity to free-living bacteria.}, }
@article {pmid8595875, year = {1996}, author = {Springer, N and Amann, R and Ludwig, W and Schleifer, KH and Schmidt, H}, title = {Polynucleobacter necessarius, an obligate bacterial endosymbiont of the hypotrichous ciliate Euplotes aediculatus, is a member of the beta-subclass of Proteobacteria.}, journal = {FEMS microbiology letters}, volume = {135}, number = {2-3}, pages = {333-336}, doi = {10.1111/j.1574-6968.1996.tb08010.x}, pmid = {8595875}, issn = {0378-1097}, mesh = {Animals ; Base Sequence ; DNA Probes ; Euplotes/*microbiology ; Gram-Negative Bacteria/classification/*genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {An almost full length 16S rRNA gene of the obligate bacterial endosymbiont Polynucleobacter necessarius was amplified using the polymerase chain reaction in combination with site-specific primers. The amplified DNA was directly sequenced and compared with other bacterial 16S rRNA sequences. P. necessarius belongs to the beta-subclass of Proteobacteria and shows the closest relationship to Alcaligenes eutrophus, Burkholderia solanacearum, and B. pickettii. In Proteobacteria and shows the closest relationship to Alcaligenes eutrophus, Burkholderia solanacearum, and B. pickettii. In situ hybridization with a specific oligonucleotide probe corroborated the assignment of the retrieved sequence to P. necessarius.}, }
@article {pmid8970720, year = {1996}, author = {Cline, K and Henry, R}, title = {Import and routing of nucleus-encoded chloroplast proteins.}, journal = {Annual review of cell and developmental biology}, volume = {12}, number = {}, pages = {1-26}, doi = {10.1146/annurev.cellbio.12.1.1}, pmid = {8970720}, issn = {1081-0706}, support = {R01 GM46951/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Biological Transport ; Cell Nucleus/*genetics/metabolism ; Chloroplasts/*metabolism ; Molecular Sequence Data ; Plant Proteins/genetics/*metabolism ; Plants/genetics/*metabolism ; }, abstract = {Most chloroplast proteins are nuclear encoded, synthesized as larger precursor proteins in the cytosol, posttranslationally imported into the organelle, and routed to one of six different compartments. Import across the outer and inner envelope membranes into the stroma is the major means for entry of proteins destined for the stroma, the thylakoid membrane, and the thylakoid lumen. Recent investigations have identified several unique protein components of the envelope translocation machinery. These include two GTP-binding proteins that appear to participate in the early events of import and probably regulate precursor recognition and advancement into the translocon. Localization of imported precursor proteins to the thylakoid membrane and thylakoid lumen is accomplished by four distinct mechanisms; two are homologous to bacterial and endoplasmic reticulum protein transport systems, one appears unique, and the last may be a spontaneous mechanism. Thus chloroplast protein targeting is a unique and surprisingly complex process. The presence of GTP-binding proteins in the envelope translocation machinery indicates a different precursor recognition process than is present in mitochondria. Mechanisms for thylakoid protein localization are in part derived from the prokaryotic endosymbiont, but are more unusual and diverse than expected.}, }
@article {pmid8915541, year = {1996}, author = {Dietrich, A and Small, I and Cosset, A and Weil, JH and Maréchal-Drouard, L}, title = {Editing and import: strategies for providing plant mitochondria with a complete set of functional transfer RNAs.}, journal = {Biochimie}, volume = {78}, number = {6}, pages = {518-529}, doi = {10.1016/0300-9084(96)84758-4}, pmid = {8915541}, issn = {0300-9084}, mesh = {Biological Transport/genetics ; Blotting, Western ; Evolution, Molecular ; Fabaceae/metabolism ; Gene Expression Regulation, Plant/genetics ; Genes, Plant/genetics ; Mitochondria/chemistry/genetics/*metabolism ; Plants, Genetically Modified ; Plants, Medicinal ; RNA Editing/*genetics ; RNA Processing, Post-Transcriptional/genetics ; RNA, Transfer/*metabolism ; Solanum tuberosum/metabolism ; Transcription, Genetic/genetics ; }, abstract = {The recombinations and mutations that plant mitochondrial DNA has undergone during evolution have led to the inactivation or complete loss of a number of the 'native' transfer RNA genes deriving from the genome of the ancestral endosymbiont. Following sequence divergence in their genes, some native mitochondrial tRNAs are 'rescued' by editing, a post-transcriptional process which changes the RNA primary sequence. According to in vitro studies with the native mitochondrial tRNA(Phe) from potato and tRNA(His) from larch, editing is required for efficient processing. Some of the native tRNA genes which have been inactivated or lost have been replaced by tRNA genes present in plastid DNA sequences acquired by the mitochondrial genome during evolution, which raises the problem of the transcriptional regulation of tRNA genes in plant mitochondria. Finally, tRNAs for which no gene is present in the mitochondrial genome are imported from the cytosol. This process is highly specific for certain tRNAs, and it has been suggested that the cognate aminoacyl-tRNA synthetases may be responsible for this specificity. Indeed, a mutation which blocks recognition of the cytosolic Arabidopsis thaliana tRNA(Ala) by the corresponding alanyl-tRNA synthetase also prevents mitochondrial import of this tRNA in transgenic plants. Conversely, no significant mitochondrial co-import of the normally cytosol-specific tRNA(Asp) was detected in transgenic plants expressing the yeast cytosolic aspartyl-tRNA synthetase fused to a mitochondrial targeting sequence, suggesting that, although necessary, recognition by a cognate aminoacyl-tRNA synthetase might not be sufficient to allow tRNA import into plant mitochondria.}, }
@article {pmid8751355, year = {1996}, author = {Springer, N and Amann, R and Ludwig, W}, title = {The design and application of ribosomal RNA-targeted, fluorescent oligonucleotide probes for the identification of endosymbionts in protozoa.}, journal = {Methods in molecular biology (Clifton, N.J.)}, volume = {50}, number = {}, pages = {133-144}, doi = {10.1385/0-89603-323-6:133}, pmid = {8751355}, issn = {1064-3745}, mesh = {Animals ; Eukaryota/*microbiology ; Nucleic Acid Hybridization ; *Oligonucleotide Probes ; RNA, Ribosomal/*analysis ; *Symbiosis ; }, }
@article {pmid8616244, year = {1996}, author = {Brinkmann, H and Martin, W}, title = {Higher-plant chloroplast and cytosolic 3-phosphoglycerate kinases: a case of endosymbiotic gene replacement.}, journal = {Plant molecular biology}, volume = {30}, number = {1}, pages = {65-75}, pmid = {8616244}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Base Sequence ; Biological Evolution ; Chloroplasts/*enzymology ; Cytosol/*enzymology ; Eukaryotic Cells ; Gene Library ; *Genes, Bacterial ; Halobacteriaceae/enzymology/*genetics ; Isoenzymes/genetics ; Molecular Sequence Data ; Multigene Family ; Phosphoglycerate Kinase/*genetics ; Plants/*enzymology ; Prokaryotic Cells ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; }, abstract = {Previous studies indicated that plant nuclear genes for chloroplast and cytosolic isoenzymes of 3-phosphoglycerate kinase (PGK) arose through recombination between a preexisting gene of the eukaryotic host nucleus for the cytosolic enzyme and an endosymbiont-derived gene for the chloroplast enzyme. We readdressed the evolution of eukaryotic pgk genes through isolation and characterisation of a pgk gene from the extreme halophilic, photosynthetic archaebacterium Haloarcula vallismortis and analysis of PGK sequences from the three urkingdoms. A very high calculated net negative charge of 63 for PGK from H. vallismortis was found which is suggested to result from selection for enzyme solubility in this extremely halophilic cytosol. We refute the recombination hypothesis proposed for the origin of plant PGK isoenzymes. The data indicate that the ancestral gene from which contemporary homologues for the Calvin cycle/glycolytic isoenzymes in higher plants derive was acquired by the nucleus from (endosymbiotic) eubacteria. Gene duplication subsequent to separation of Chlamydomonas and land plant lineages gave rise to the contemporary genes for chloroplast and cytosolic PGK isoenzymes in higher plants, and resulted in replacement of the preexisting gene for PGK of the eukaryotic cytosol. Evidence suggesting a eubacterial origin of plant genes for PGK via endosymbiotic gene replacement indicates that plant nuclear genomes are more highly chimaeric, i.e. contain more genes of eubacterial origin, than is generally assumed.}, }
@article {pmid8578971, year = {1996}, author = {Johnson, EA and Schroeder, WA}, title = {Microbial carotenoids.}, journal = {Advances in biochemical engineering/biotechnology}, volume = {53}, number = {}, pages = {119-178}, doi = {10.1007/BFb0102327}, pmid = {8578971}, issn = {0724-6145}, mesh = {Antioxidants/pharmacology/therapeutic use ; Bacteria/chemistry ; *Carotenoids/biosynthesis/chemistry/genetics/metabolism/pharmacology/physiology/therapeutic use ; Clinical Trials as Topic ; Eukaryota/chemistry ; Fungi/chemistry ; Humans ; Phylogeny ; Plants/chemistry ; Preventive Medicine ; Structure-Activity Relationship ; }, abstract = {Carotenoids occur universally in photosynthetic organisms but sporadically in nonphotosynthetic bacteria and eukaryotes. The primordial carotenogenic organisms were cyanobacteria and eubacteria that carried out anoxygenic photosynthesis. The phylogeny of carotenogenic organisms is evaluated to describe groups of organisms which could serve as sources of carotenoids. Terrestrial plants, green algae, and red algae acquired stable endosymbionts (probably cyanobacteria) and have a predictable complement of carotenoids compared to prokaryotes, other algae, and higher fungi which have a more diverse array of pigments. Although carotenoids are not synthesized by animals, they are becoming known for their important role in protecting against damage by singlet oxygen and preventing chronic diseases in humans. The growth of aquaculture during the past decade as well as the biological roles of carotenoids in human disease will increase the demand for carotenoids. Microbial synthesis offers a promising method for production of carotenoids.}, }
@article {pmid8572692, year = {1996}, author = {Noda, H and Kodama, K}, title = {Phylogenetic position of yeastlike endosymbionts of anobiid beetles.}, journal = {Applied and environmental microbiology}, volume = {62}, number = {1}, pages = {162-167}, pmid = {8572692}, issn = {0099-2240}, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; Coleoptera/*microbiology ; Introns/genetics ; Mitosporic Fungi/classification/*genetics ; Molecular Sequence Data ; *Phylogeny ; RNA, Fungal/genetics ; RNA, Ribosomal/genetics ; Sequence Analysis, DNA ; *Symbiosis ; }, abstract = {The Anobiid beetles Stegobium paniceum and Lasioderma serricorne possess the intracellular yeastlike symbionts Symbiotaphrina buchneri and Symbiotaphrina kochii, respectively, in the mycetome between the foregut and midgut. The nucleotide sequences of the small-subunit rRNA-encoding genes of the symbionts were determined for phylogenetic analysis. Five group I introns were found in the small-subunit rRNA-encoding genes of S. buchneri, but S. kochii lacked introns. The phylogenetic position of both symbionts was close to the class Discomycetes, which is a paraphyletic group. The two symbionts formed a monophyletic group distinct from the other major lineages. Both appear to have parted from other filamentous fungi during the early radiation of the euascomycetes and to have later become obligatory partners of the beetles.}, }
@article {pmid8719164, year = {1995}, author = {Sironi, M and Bandi, C and Sacchi, L and Di Sacco, B and Damiani, G and Genchi, C}, title = {Molecular evidence for a close relative of the arthropod endosymbiont Wolbachia in a filarial worm.}, journal = {Molecular and biochemical parasitology}, volume = {74}, number = {2}, pages = {223-227}, doi = {10.1016/0166-6851(95)02494-8}, pmid = {8719164}, issn = {0166-6851}, mesh = {Animals ; Arthropods/*microbiology ; Base Sequence ; DNA Primers/genetics ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Dirofilaria/*microbiology/ultrastructure ; Dogs ; Female ; Male ; Microscopy, Electron ; Molecular Sequence Data ; Rickettsiaceae/classification/*genetics/*isolation &amp; purification ; Symbiosis ; }, }
@article {pmid8520584, year = {1995}, author = {Gilson, P and Waller, R and McFadden, G}, title = {Preliminary characterisation of chlorarachniophyte mitochondrial DNA.}, journal = {The Journal of eukaryotic microbiology}, volume = {42}, number = {6}, pages = {696-701}, doi = {10.1111/j.1550-7408.1995.tb01618.x}, pmid = {8520584}, issn = {1066-5234}, mesh = {Animals ; Bacteria/classification/genetics ; Chloroplasts/metabolism ; DNA, Mitochondrial/*genetics/isolation &amp; purification ; DNA, Protozoan/*genetics/isolation &amp; purification ; Eukaryota/classification/*genetics ; Fungi/classification/genetics ; Humans ; In Situ Hybridization ; Karyotyping ; Mitochondria/metabolism ; *Phylogeny ; Plants/classification/genetics ; Transcription, Genetic ; }, abstract = {The division Chlorarachniophyte comprises amoeboflagellate protists with complex chloroplasts derived from the endosymbiosis of a eukaryotic alga. Analysis of chlorarachniophyte chromosomal DNAs by pulsed-field gel electrophoresis revealed an apparently linear 36-kb chromosome that could not be ascribed to either the host or endosymbiont nuclei. A single eubacterial-like small subunit ribosomal RNA gene is encoded on this chromosome and phylogenetic analyses places this gene within a clade of mitochondrial genes from other eukaryotes. High resolution in situ hybridization demonstrates that transcripts of the small subunit ribosomal RNA gene encoded by the 36-kb chromosome are exclusively located in the mitochondria. The 36-kb chromosome thus likely represents a linear mitochondrial genome. Small amounts of an apparently dimeric (72 kb) form are also detectable in pulsed-field gel electrophoresis.}, }
@article {pmid8564308, year = {1995}, author = {Nakamura, M and Obokata, J}, title = {Tobacco nuclear genes for Photosystem I subunits, psaD, psaE and psaH share an octamer motif bound with nuclear proteins.}, journal = {Plant &amp; cell physiology}, volume = {36}, number = {7}, pages = {1393-1397}, pmid = {8564308}, issn = {0032-0781}, mesh = {Base Sequence ; DNA, Plant/genetics ; Genes, Plant ; Molecular Sequence Data ; Nuclear Proteins/*metabolism ; Photosynthetic Reaction Center Complex Proteins/*genetics ; Photosystem I Protein Complex ; *Plants, Toxic ; Protein Binding ; Tobacco/*genetics ; }, abstract = {In Nicotiana sylvestris, nuclear-encoded photosystem I (PSI) genes, psaD, psaE and psaH, share an octamer motif bound with three phosphoproteins. This motif is not found in the chloroplast genome. From the view point of endosymbiont hypothesis, these results suggest that a set of ancient PSI genes acquired a common cis-element in the nucleus after they were transferred from the ancestral organelle.}, }
@article {pmid7547309, year = {1995}, author = {Aksoy, S}, title = {Wigglesworthia gen. nov. and Wigglesworthia glossinidia sp. nov., taxa consisting of the mycetocyte-associated, primary endosymbionts of tsetse flies.}, journal = {International journal of systematic bacteriology}, volume = {45}, number = {4}, pages = {848-851}, doi = {10.1099/00207713-45-4-848}, pmid = {7547309}, issn = {0020-7713}, support = {AI-28778/AI/NIAID NIH HHS/United States ; AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacteria/*classification ; Base Sequence ; Enterobacteriaceae/classification ; Molecular Sequence Data ; Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {The primary endosymbionts (P-endosymbionts) of tsetse flies (Diptera: Glossinidae) are harbored inside specialized cells (mycetocytes) in the anterior region of the gut, and these specialized cells form a white, U-shaped organelle called mycetome. The P-endosymbionts of five tsetse fly species belonging to the Glossinidae have been characterized morphologically, and their 16S ribosomal DNA sequences have been determined for phylogenetic analysis. These organisms were found to belong to a distinct lineage related to the family Enterobacteriaceae in the gamma subdivision of Proteobacteria, which includes the secondary endosymbionts of various insects and Escherichia coli. These bacteria are also related to the P-endosymbionts of aphids, Buchnera aphidicola. Signature sequences in the 16S ribosomal DNA and genomic organizational differences which distinguish the tsetse fly P-endosymbionts from members of the Enterobacteriaceae and from the genus Buchnera are described in this paper. I propose that the P-endosymbionts of tsetse flies should be classified in a new genus, the genus Wigglesworthia, and a new species, Wigglesworthia glossinidia. The P-endosymbiont found in the mycetocytes of Glossina morsitans morsitans is designated the type strain of this species.}, }
@article {pmid8579685, year = {1995}, author = {Supriyono, A and Schwarz, B and Wray, V and Witte, L and Müller, WE and van Soest, R and Sumaryono, W and Proksch, P}, title = {Bioactive alkaloids from the tropical marine sponge Axinella carteri.}, journal = {Zeitschrift fur Naturforschung. C, Journal of biosciences}, volume = {50}, number = {9-10}, pages = {669-674}, doi = {10.1515/znc-1995-9-1012}, pmid = {8579685}, issn = {0939-5075}, mesh = {Alkaloids/chemistry/*isolation &amp; purification/*toxicity ; Animals ; Cell Survival/*drug effects ; Chromatography, High Pressure Liquid ; Indonesia ; Larva ; Leukemia L5178 ; Magnetic Resonance Spectroscopy ; Mice ; Molecular Structure ; *Porifera ; Seawater ; *Spodoptera ; Structure-Activity Relationship ; Tropical Climate ; Tumor Cells, Cultured ; }, abstract = {Analysis of the tropical marine sponge Axinella carteri afforded six unusual alkaloids, including the new brominated guanidine derivative 3-bromo-hymenialdisine. The structure elucidation of the new alkaloid is described. The alkaloid patterns of sponges collected in Indonesia or in the Philippines were shown to be qualitatively identical suggesting de novo synthesis by the sponge or by endosymbiontic microorganisms rather than uptake by filter feeding. All alkaloids were screened for insecticidal activity as well as for cytotoxicity. The guanidine alkaloids hymenialdisine and debromohymenialdisine exhibited insecticidal activity towards neonate larvae of the polyphagous pest insect Spodoptera littoralis (LD50s of 88 and 125 ppm, respectively), when incorporated into artificial diet and offered to the larvae in a chronic feeding bioassay. The remaining alkaloids, including the new compound were inactive in this bioassay. Cytotoxicity was studied in vitro using L5178y mouse lymphoma cells. Debromohymenialdisine was again the most active compound (ED50 1.8 micrograms/ml) followed by hymenialdisine and 3-bromohymenialdisine, which were essentially equitoxic and exhibited ED50s of 3.9 micrograms/ml in both cases. The remaining alkaloids were inactive against this cell line.}, }
@article {pmid7581321, year = {1995}, author = {Gautom, RK and Fritsche, TR}, title = {Transmissibility of bacterial endosymbionts between isolates of Acanthamoeba spp.}, journal = {The Journal of eukaryotic microbiology}, volume = {42}, number = {5}, pages = {452-456}, doi = {10.1111/j.1550-7408.1995.tb05890.x}, pmid = {7581321}, issn = {1066-5234}, mesh = {Acanthamoeba/*microbiology ; Animals ; Cornea/parasitology ; DNA Fingerprinting ; DNA, Mitochondrial/genetics ; DNA, Protozoan/genetics ; Gram-Negative Bacteria/growth &amp; development/*physiology ; Humans ; *Symbiosis ; }, abstract = {Experimental transmission of two bacterial endosymbionts to symbiont-free isolates of Acanthamoeba spp. was studied to determine specificity of the host-symbiont relationship. Both symbionts originated from amoebic isolates displaying an identical mitochondrial DNA EcoRI fingerprint (group AcUW II). Symbioses were readily established in one amoebic isolate which displayed a homologous mtDNA fingerprint (group AcUW II). Exposure of a heterologous amoebic isolate (group AcUW IV) to the two symbionts resulted in either cell death or encystation without the establishment of symbioses. While symbioses were established with an amoebic isolate from a second heterologous group (AcUWI), a unique membranous sheath appeared and persisted around one of the symbionts which did not exist in the original host. An isolate representing a third heterologous amoebic group (AcUW VI) was variable in its susceptibility with one symbiont unable to infect the host and the other becoming established only after an initial reaction in which trophozoites rounded-up and floated off the substrate. These studies suggest that a specific recognition system exists between particular isolates of Acanthamoeba and their symbionts, and that the appearance of a killer phenotype is related to contact between mismatched though recognized, pairs.}, }
@article {pmid7666450, year = {1995}, author = {Helmchen, TA and Bhattacharya, D and Melkonian, M}, title = {Analyses of ribosomal RNA sequences from glaucocystophyte cyanelles provide new insights into the evolutionary relationships of plastids.}, journal = {Journal of molecular evolution}, volume = {41}, number = {2}, pages = {203-210}, pmid = {7666450}, issn = {0022-2844}, mesh = {Base Sequence ; DNA, Ribosomal/genetics ; Eukaryota/*genetics ; Molecular Sequence Data ; Phycobilisomes ; *Phylogeny ; Plastids/*genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, DNA ; }, abstract = {Glaucocystophyte algae (sensu Kies, Berl. Deutsch. Bot. Ges. 92, 1979) contain plastids (cyanelles) that retain the peptidoglycan wall of the putative cyano-bacterial endosymbiont; this and other ultrastructural characters (e.g., unstacked thylakoids, phycobilisomes) have suggested that cyanelles are "primitive" plastids that may represent undeveloped associations between heterotrophic "host" cells (i.e., glaucocystophytes) and cyanobacteria. To test the monophyly of glaucocystophyte cyanelles and to determine their evolutionary relationship to other plastids, complete 16S ribosomal RNA sequences were determined for Cyanophora paradoxa, Glaucocystis nostochinearum, Glaucosphaera vacuolata, and Gloeochaete wittrockiana. Plastid rRNAs were analyzed with the maximum-likelihood, maximum-parsimony, and neighbor-joining methods. The phylogenetic analyses show that the cyanelles of C. paradoxa, G. nostochinearum, and G. wittrockiana form a distinct evolutionary lineage; these cyanelles presumably share a monophyletic origin. The rDNA sequence of G. vacuolata was positioned within the nongreen plastid lineage. This result is consistent with analyses of nuclear-encoded rRNAs that identify G. vacuolata as a rhodophyte and support is removal from the Glaucocystophyta. Results of a global search with the maximum-likelihood method suggest that cyanelles are the first divergence among all plastids; this result is consistent with a single loss of the peptidoglycan wall in plastids after the divergence of the cyanelles. User-defined tree analyses with the maximum-likelihood method indicate, however, that the position of the cyanelles is not stable within the rRNA phylogenies. Both maximum-parsimony and neighbor-joining analyses showed a close evolutionary relationship between cyanelles and non-green plastids; these phylogenetic methods were sensitive to inclusion/exclusion of the G. wittrockiana cyanelle sequence.(ABSTRACT TRUNCATED AT 250 WORDS)}, }
@article {pmid7608990, year = {1995}, author = {Bracho, AM and Martínez-Torres, D and Moya, A and Latorre, A}, title = {Discovery and molecular characterization of a plasmid localized in Buchnera sp. bacterial endosymbiont of the aphid Rhopalosiphum padi.}, journal = {Journal of molecular evolution}, volume = {41}, number = {1}, pages = {67-73}, pmid = {7608990}, issn = {0022-2844}, mesh = {Amino Acid Sequence ; Animals ; Aphids/genetics/*microbiology ; Base Sequence ; Conserved Sequence ; DNA, Circular/chemistry/genetics ; Gram-Negative Bacteria/*genetics/isolation &amp; purification ; Molecular Sequence Data ; *Plasmids ; Replicon ; Sequence Homology, Amino Acid ; Species Specificity ; *Symbiosis ; }, abstract = {We have identified and completely sequenced a novel plasmid isolated from the aphid Rhopalosiphum padi. Evidence which suggests that the plasmid occurs localized within the bacterial endosymbionts is presented. The plasmid contains the four genes that constitute the entire leucine operon. This fact makes it really unique since most plasmids are dispensable and lack genes that encode essential anabolic functions. Four more phloem-feeding aphid species also seem to contain homologous plasmids. Although further work is necessary, we hypothesize that this plasmid has appeared during the evolution of the symbiotic association between the aphid and the bacterial endosymbiont. The fact that this plasmid contains the entire leucine operon can be related to physiological evidence showing that the aphid host's diet of plant phloem is deficient in essential amino acids.}, }
@article {pmid7793955, year = {1995}, author = {Dubilier, N and Giere, O and Distel, DL and Cavanaugh, CM}, title = {Characterization of chemoautotrophic bacterial symbionts in a gutless marine worm Oligochaeta, Annelida) by phylogenetic 16S rRNA sequence analysis and in situ hybridization.}, journal = {Applied and environmental microbiology}, volume = {61}, number = {6}, pages = {2346-2350}, pmid = {7793955}, issn = {0099-2240}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; Base Sequence ; In Situ Hybridization ; Molecular Sequence Data ; Oligochaeta/*microbiology ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Sequence Analysis ; Symbiosis ; }, abstract = {The phylogenetic relationships of chemoautotrophic endosymbionts in the gutless marine oligochaete Inanidrilus leukodermatus to chemoautotrophic ecto- and endosymbionts from other host phyla and to free-living bacteria were determined by comparative 16S rRNA sequence analysis. Fluorescent in situ hybridization confirmed that the 16S rRNA sequence obtained from these worms originated from the symbionts. The symbiont sequence is unique to I. leukodermatus. In phylogenetic trees inferred by both distance and parsimony methods, the oligochaete symbiont is peripherally associated with one of two clusters of chemoautotrophic symbionts that belong to the gamma subdivision of the Proteobacteria. The endosymbionts of this oligochaete form a monophyletic group with chemoautotrophic ectosymbionts of a marine nematode. The oligochaete and nematode symbionts are very closely related, although their hosts belong to separate, unrelated animal phyla. Thus, cospeciation between the nematode and oligochaete hosts and their symbionts could not have occurred. Instead, the similar geographic locations and habitats of the hosts may have influenced the establishment of these symbioses.}, }
@article {pmid7643412, year = {1995}, author = {Cole, RA and Slade, MB and Williams, KL}, title = {Dictyostelium discoideum mitochondrial DNA encodes a NADH:ubiquinone oxidoreductase subunit which is nuclear encoded in other eukaryotes.}, journal = {Journal of molecular evolution}, volume = {40}, number = {6}, pages = {616-621}, pmid = {7643412}, issn = {0022-2844}, mesh = {Animals ; Base Sequence ; Biological Evolution ; DNA, Mitochondrial/*genetics ; Dictyostelium/enzymology/*genetics ; Electron Transport Complex I ; Molecular Sequence Data ; NADH, NADPH Oxidoreductases/*genetics ; Paracoccus denitrificans/enzymology/genetics ; Phylogeny ; Sequence Alignment ; }, abstract = {Complex I, a key component of the mitochondrial electron transport system, is thought to have evolved from at least two separate enzyme systems prior to the evolution of mitochondria from a bacterial endosymbiont, but the genes for one of the enzyme systems are thought to have subsequently been transferred to the nuclear DNA. We demonstrated that the cellular slime mold Dictyostelium discoideum retains the ancestral characteristic of having mitochondria encoding at least one gene (80-kDa subunit) that is nuclear encoded in other eukaryotes. This is consistent with the cellular slime molds of the family Dictyosteliaceae having diverged from other eukaryotes at an early stage prior to the loss of the mitochondrial gene in the lineage giving rise to plants and animals. The D. discoideum mitochondrially encoded 80-kDa subunit of complex I exhibits a twofold-higher mutation rate compared with the homologous chromosomal gene in other eukaryotes, making it the most divergent eukaryotic form of this protein.}, }
@article {pmid7766160, year = {1995}, author = {Kolibachuk, D and Rouhbakhsh, D and Baumann, P}, title = {Aromatic amino acid biosynthesis in Buchnera aphidicola (endosymbiont of aphids): cloning and sequencing of a DNA fragment containing aroH-thrS-infC-rpmI-rplT.}, journal = {Current microbiology}, volume = {30}, number = {5}, pages = {313-316}, pmid = {7766160}, issn = {0343-8651}, mesh = {3-Deoxy-7-Phosphoheptulonate Synthase/genetics ; Amino Acids/*biosynthesis ; Animals ; Aphids/*microbiology ; Bacteria/*genetics/*metabolism ; Base Sequence ; Cloning, Molecular ; DNA, Bacterial/genetics ; Escherichia coli/genetics ; *Genes, Bacterial ; Molecular Sequence Data ; Operon ; Restriction Mapping ; Symbiosis ; }, abstract = {A 4.5-kilobase DNA fragment from Buchnera aphidicola, the endosymbiont of the aphid Schizaphis graminum, was cloned and sequenced. On the basis of homology to Escherichia coli, the following genes were found in the order listed: aroH-thrS-infC-rpmI-rplT. AroH corresponds to the E. coli tryptophan-inhibited 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) synthase. Evidence was presented indicating that this is the sole gene for DAHP synthase in the B. aphidicola genome. This enzyme initiates the complex branched pathway leading to aromatic amino acid biosynthesis. The presence of aroH is consistent with past observations indicating that aphid endosymbionts are able to synthesize tryptophan for the aphid host. thrS, infC, rpmI, and rplT correspond to genes for threonine tRNA synthase, initiation factor-3, and large ribosome subunit proteins L35 and L20, respectively. Sequence comparisons indicate some differences and similarities between E. coli and B. aphidicola with respect to the possible regulation of synthesis of these proteins.}, }
@article {pmid7751302, year = {1995}, author = {Margolin, W and Bramhill, D and Long, SR}, title = {The dnaA gene of Rhizobium meliloti lies within an unusual gene arrangement.}, journal = {Journal of bacteriology}, volume = {177}, number = {10}, pages = {2892-2900}, pmid = {7751302}, issn = {0021-9193}, support = {2R01-GM30962/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Bacteria/genetics ; Bacterial Proteins/*genetics ; Base Sequence ; Biological Evolution ; Caulobacter/genetics ; Conserved Sequence ; DNA-Binding Proteins/*genetics ; Enoyl-CoA Hydratase/genetics ; Genes, Bacterial/*genetics ; Genomic Library ; Mitochondria/enzymology/genetics ; Molecular Sequence Data ; Open Reading Frames/genetics ; Restriction Mapping ; Ribosomal Proteins/genetics ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sinorhizobium meliloti/*genetics ; }, abstract = {Rhizobium meliloti exists either as a free-living soil organism or as a differentiated endosymbiont bacteroid form within the nodules of its host plant, alfalfa (Medicago sativa), where it fixes atmospheric N2. Differentiation is accompanied by major changes in DNA replication and cell division. In addition, R. meliloti harbors three unique large circular chromosome-like elements whose replication coordination may be complex. As part of a study of DNA replication control in R. meliloti, we isolated a dnaA homolog. The deduced open reading frame predicts a protein of 57 kDa that is 36% identical to the DnaA protein of Escherichia coli, and the predicted protein was confirmed by immunoblot analysis. In a comparison with the other known DnaA proteins, this protein showed the highest similarity to that of Caulobacter crescentus and was divergent in some domains that are highly conserved in other unrelated species. The dnaA genes of a diverse group of bacteria are adjacent to a common set of genes. Surprisingly, analysis of the DNA sequence flanking dnaA revealed none of these genes, except for an rpsT homolog, also found upstream of dnaA in C. crescentus. Instead, upstream of rpsT lie homologs of fpg, encoding a DNA glycosylase, and fadB1, encoding an enoyl-coenzyme A hydratase with a strikingly high (53 to 55%) level of predicted amino acid identity to two mammalian mitochondrial homologs. Downstream of dnaA, there are two open reading frames that are probably expressed but are not highly similar to any genes in the databases. These results show that R. meliloti dnaA is located within a novel gene arrangement.}, }
@article {pmid7587586, year = {1995}, author = {Gilson, P and McFadden, GI}, title = {The chlorarachniophyte: a cell with two different nuclei and two different telomeres.}, journal = {Chromosoma}, volume = {103}, number = {9}, pages = {635-641}, pmid = {7587586}, issn = {0009-5915}, mesh = {Animals ; Base Sequence ; Blotting, Southern ; Cell Nucleus/*genetics/ultrastructure ; Chloroplasts/*genetics/ultrastructure ; Chromosome Mapping ; Chromosomes ; Cloning, Molecular ; DNA/analysis ; DNA, Ribosomal/genetics ; Electrophoresis, Gel, Pulsed-Field ; Eukaryota/*genetics ; Microscopy, Electron ; Molecular Sequence Data ; RNA, Ribosomal, 18S/genetics ; RNA, Ribosomal, 5.8S/genetics ; Repetitive Sequences, Nucleic Acid ; Symbiosis ; Telomere/*genetics ; }, abstract = {Chlorarachniophyte algae contain a complex chloroplast derived from the endosymbiosis of a eukaryotic alga. The reduced nucleus of the endosymbiont, the nucleomorph, is located between the inner and outer pair of membranes surrounding the chloroplast. The nucleomorph of chlorarachniophytes has previously been demonstrated to contain at least three small linear chromosomes. Here we describe cloning the end of the smallest nucleomorph chromosome which is shown to carry a telomere consisting of a tandemly repeated 7 bp sequence, TCTAGGG. Using the telomere repeat as a probe, we show that nucleomorph telomeres display typical hetero-disperse size distribution. The nucleomorph is shown to contain only three chromosomes with a haploid genome size of just 380 kb. All six nucleomorph chromosome termini are identical with an rRNA cistron closely linked to the telomere. The nucleomorph chromosomes thus have relatively large inverted repeats at their ends. Chromosomes from the host nucleus are shown to have a different telomere repeat motif to that of the nucleomorph chromosomes.}, }
@article {pmid7711069, year = {1995}, author = {Schmidt, M and Svendsen, I and Feierabend, J}, title = {Analysis of the primary structure of the chloroplast isozyme of triosephosphate isomerase from rye leaves by protein and cDNA sequencing indicates a eukaryotic origin of its gene.}, journal = {Biochimica et biophysica acta}, volume = {1261}, number = {2}, pages = {257-264}, doi = {10.1016/0167-4781(95)00015-9}, pmid = {7711069}, issn = {0006-3002}, mesh = {Amino Acid Sequence ; Base Sequence ; Chloroplasts/*enzymology ; *Genes, Plant ; Molecular Sequence Data ; Phylogeny ; Secale/*enzymology ; Triose-Phosphate Isomerase/*chemistry/genetics ; }, abstract = {The primary structure of the chloroplast isozyme of triosephosphate isomerase from rye leaves was identified by protein and cDNA sequencing and compared to the deduced amino acid sequence of a cDNA for the cytosolic isozyme. The mature cytosolic and chloroplast isozyme proteins share 64% amino acid sequence identity. The cDNA for the chloroplast isozyme codes for a precursor protein consisting of an N-terminal transit peptide of Mr 4351 and a mature subunit of Mr 27,282. Southern blot analysis indicates that the two rye isozymes are encoded by two independent single genes. Amino acid residues or sequence regions of basic functional relevance in known triosephosphate isomerases are strictly conserved in the chloroplast isozyme. The chloroplast isozyme contains 6 cysteine residues, instead of 4 in the cytosolic isozyme. A cysteine at position 143 of the chloroplast isozyme appears to be modified. Phylogenetic trees constructed on the basis of sequence comparisons for triosephosphate isomerases from different species of all major taxonomic groups indicate that the chloroplast isozyme is much more closely related to eukaryotic cytosolic enzymes than to eubacterial enzymes. The results indicate that the nuclear gene for the chloroplast isozyme originated with that for the cytosolic isozyme through duplication of an ancestral eukaryotic gene, rather than through gene transfer from a prokaryotic endosymbiont.}, }
@article {pmid7708736, year = {1995}, author = {Rowan, R and Knowlton, N}, title = {Intraspecific diversity and ecological zonation in coral-algal symbiosis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {92}, number = {7}, pages = {2850-2853}, pmid = {7708736}, issn = {0027-8424}, mesh = {Animals ; *Ecology ; Eukaryota/*physiology ; Genotype ; Molecular Sequence Data ; Mollusca/genetics/*physiology ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Species Specificity ; *Symbiosis ; }, abstract = {All reef-building corals are obligately associated with photosynthetic microalgal endosymbionts called zooxanthellae. Zooxanthella taxonomy has emphasized differences between species of hosts, but the possibility of ecologically significant zooxanthella diversity within hosts has been the subject of speculation for decades. Analysis of two dominant Caribbean corals showed that each associates with three taxa of zooxanthellae that exhibit zonation with depth--the primary environmental gradient for light-dependent marine organisms. Some colonies apparently host two taxa of symbionts in proportions that can vary across the colony. This common occurrence of polymorphic, habitat-specific symbioses challenges conventional understanding of the units of biodiversity but also illuminates many distinctive aspects of marine animal-algal associations. Habitat specificity provides ecological explanations for the previously documented poor concordance between host and symbiont phylogenies and the otherwise surprising lack of direct, maternal transmission of symbionts in many species of hosts. Polymorphic symbioses may underlie the conspicuous and enigmatic variability characteristic of responses to environmental stress (e.g., coral "bleaching") and contribute importantly to the phenomenon of photoadaptation.}, }
@article {pmid7740047, year = {1995}, author = {Bandi, C and Sironi, M and Damiani, G and Magrassi, L and Nalepa, CA and Laudani, U and Sacchi, L}, title = {The establishment of intracellular symbiosis in an ancestor of cockroaches and termites.}, journal = {Proceedings. Biological sciences}, volume = {259}, number = {1356}, pages = {293-299}, doi = {10.1098/rspb.1995.0043}, pmid = {7740047}, issn = {0962-8452}, mesh = {Animals ; Bacteria/*genetics/isolation &amp; purification ; Base Sequence ; Biological Evolution ; Cockroaches/genetics/*microbiology ; DNA, Bacterial/genetics ; DNA, Ribosomal/genetics ; Fat Body/microbiology ; Insecta/genetics/*microbiology ; Molecular Sequence Data ; *Symbiosis ; }, abstract = {All cockroaches examined so far have been found to harbour a bacterial endosymbiont in specialized cells of the fat body, whereas Mastotermes darwiniensis is the only termite currently known to harbour an intracellular symbiont. The localization and mode of transmission of these bacteria are surprisingly similar, but so far no data have been published on their phylogenetic relationships. To address this issue, molecular sequence data were obtained from the genes encoding the small subunit ribosomal RNA of the M. darwiniensis endosymbiont, and compared with those obtained from endosymbionts of seven species of cockroaches. Molecular phylogenetic analysis unambiguously placed all these bacteria among the flavobacteria-bacteroides, indicating that the endosymbiont of M. darwiniensis is the sister group to the cockroach endosymbionts examined. Additionally, nucleotide divergence between the endosymbionts appears to be congruent with the palaeontological data on the hosts's evolution. These results support previous claims that the original infection occurred in an ancestor common to cockroaches and termites. A loss of endosymbionts should subsequently have occurred in all termite lineages, except that which gave rise to M. darwiniensis.}, }
@article {pmid7535281, year = {1995}, author = {Rouhbakhsh, D and Baumann, P}, title = {Characterization of a putative 23S-5S rRNA operon of Buchnera aphidicola (endosymbiont of aphids) unlinked to the 16S rRNA-encoding gene.}, journal = {Gene}, volume = {155}, number = {1}, pages = {107-112}, doi = {10.1016/0378-1119(94)00910-k}, pmid = {7535281}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Bacteria/*genetics ; Base Sequence ; Molecular Sequence Data ; Nucleic Acid Conformation ; RNA, Bacterial/*genetics ; RNA, Ribosomal, 16S/genetics ; RNA, Ribosomal, 23S/genetics ; RNA, Ribosomal, 5S/genetics ; Sequence Homology, Nucleic Acid ; rRNA Operon/*genetics ; }, abstract = {Buchnera aphidicola (Ba) is an endosymbiont of the aphid Schizaphis graminum. In order to obtain information on highly expressed genes, we have chosen to study Ba genes coding for rRNAs. Previously, the single-copy rrs gene was cloned and sequenced [Munson et al., Gene 137 (1993) 171-178], and found to constitute a single transcription unit unlinked to rrl and rrf. In the present study, a 6.1-kb Ba DNA fragment containing rrl was cloned into Escherichia coli (Ec) and sequenced. Based on sequence similarity to Ec, the following genes were identified: aroE-tRNA(Glu)-rrl-rrf-cysS. AroE and CysS had 48 and 54% amino acid (aa) identity, respectively, to the corresponding Ec proteins; tRNA(Glu), rrl and rrf had 80-90% nucleotide (nt) identity with the corresponding genes of Ec rrnB. Ba tRNA(Glu)-rrl-rrs appears to be part of a single transcriptional unit; a putative promoter and a Rho-independent terminator were identified. Comparisons of sequences of aroE-rrl from endosymbionts of seven additional species of aphids indicated conservation of the -35 (TTGACT) and -10 (TGTAA/TT) promoter regions, and boxA, tRNA(Glu) and boxC. Secondary structure analysis indicated that the Ba tRNA(Glu)-rrl-rrf operon resembled the homologous region of Ec rrnB. The results of this and previous studies indicate that Ba differs from most bacteria in having the single-copy rRNA genes organized into two transcription units.}, }
@article {pmid7737148, year = {1995}, author = {Jaussi, R}, title = {Homologous nuclear-encoded mitochondrial and cytosolic isoproteins. A review of structure, biosynthesis and genes.}, journal = {European journal of biochemistry}, volume = {228}, number = {3}, pages = {551-561}, doi = {10.1111/j.1432-1033.1995.tb20294.x}, pmid = {7737148}, issn = {0014-2956}, mesh = {Animals ; Cell Nucleus/*metabolism ; Cytosol/*metabolism ; Gene Expression Regulation ; Humans ; Mitochondria/*metabolism ; Protein Biosynthesis ; Protein Conformation ; *Proteins/chemistry/genetics ; RNA, Messenger/genetics ; }, abstract = {Mitochondrial and cytosolic proteins may be expected to differ in specific traits due to their different intracellular location. However, the identification of these differences between mitochondrial and cytosolic proteins is complicated by the heterogeneity of the two protein groups. These difficulties have been overcome by comparing traits of homologous genes, which are derived from a common ancestor gene, and their gene products. An earlier report [Hartmann, C., Christen, P. &amp; Jaussi, R. (1991) Nature 352, 762-763] describing a positive net charge difference between the mature parts of nuclear-encoded mitochondrial proteins and their homologous cytosolic isoproteins, could be corroborated by extending the data collection. New data were gathered from computer databases and published studies. The average isoelectric points of the mitochondrial and cytosolic isoproteins are 7.5 and 6.5, respectively. Depending on the type of protein, the observed difference results from differences in the number of basic and/or acidic amino acid residues in the isoproteins. Probably both the conditions required for mitochondrial protein import and the local conditions within the organelle furthered the evolution of basic protein structures. The contribution of the mitochondrial targeting peptide to the positive charge of precursors of nuclear-encoded mitochondrial proteins is largest when the value of the isoelectric point of the mature protein is small. This mutual dependence of the charge of the targeting peptide and the mature protein part supports the notion that positive charge is essential for mitochondrial protein import. Several traits other than electric charge, i.e. codon usage, chromosome location, structural organization or regulation of the genes, do not show specific differences between the sets of the heterotopic isoproteins. There is no preference of gene location for any of the gene sets; only rarely are the genes for a mitochondrial and a cytosolic isoprotein located on the same chromosome. A variant of the 3' splice-site consensus exists in genes of nuclear-encoded mitochondrial proteins. This is most likely a consequence of the evolution of the genes in separate lineages before endosymbiosis led to the formation of mitochondria. Some of the original mRNA group II intron self-splicing functions of the endosymbiont seem to persist in part of the cytosolic splicing machinery and apparently require a specific consensus sequence [Juretic, N., Jaussi, R., Mattes, U. &amp; Christen, P. (1987) Nucleic Acids Res.15, 10083-10086].}, }
@article {pmid7765846, year = {1995}, author = {Kolibachuk, D and Baumann, P}, title = {Buchnera aphidicola (aphid-endosymbiont) glyceraldehyde-3-phosphate dehydrogenase: molecular cloning and sequence analysis.}, journal = {Current microbiology}, volume = {30}, number = {3}, pages = {133-136}, pmid = {7765846}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Base Sequence ; Chromosome Mapping ; DNA, Bacterial/genetics ; Escherichia coli/genetics ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Gram-Negative Bacteria/*enzymology/genetics ; Molecular Sequence Data ; Sequence Homology, Amino Acid ; }, abstract = {Buchnera aphidicola is an endosymbiont of the aphid Schizaphis graminum. A 3.9-kb B. aphidicola DNA fragment was sequenced and found to contain two open reading frames (ORFs). The deduced amino acid sequence of one of the ORFs had an 85% identity to Escherichia coli glyceraldehyde-3-phosphate dehydrogenase (Gap). Both of these proteins have a higher similarity to eukaryotic than to prokaryotic Gaps. The second ORF could not be readily identified. The sequence of the putative product indicated that it was a member of the family of ATP-binding, membrane-associated proteins. The highest amino acid identity (36%) was with E. coli FtsE, a protein involved in cell division.}, }
@article {pmid7742976, year = {1995}, author = {Lai, CY and Baumann, P and Moran, NA}, title = {Genetics of the tryptophan biosynthetic pathway of the prokaryotic endosymbiont (Buchnera) of the aphid Schlechtendalia chinensis.}, journal = {Insect molecular biology}, volume = {4}, number = {1}, pages = {47-59}, doi = {10.1111/j.1365-2583.1995.tb00007.x}, pmid = {7742976}, issn = {0962-1075}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Base Sequence ; Biological Evolution ; Chromosomes, Bacterial ; Cloning, Molecular ; DNA, Bacterial/genetics ; Genes, Bacterial ; Gram-Negative Bacteria/*genetics/metabolism ; Molecular Sequence Data ; *Symbiosis ; Tryptophan/*biosynthesis ; }, abstract = {Two DNA fragments (3941 and 7152 base pairs) from the procaryotic endosymbiont (Buchnera) of the aphid Schlechtendalia chinensis were cloned and sequenced. The smaller fragment contained trpEG and the larger fragment contained trpDC(F)BA, genes coding for enzymes of the tryptophan biosynthetic pathway which convert chorismate to tryptophan. Both of these gene clusters were present as one copy on the endosymbiont chromosome and probably constitute two transcription units. The deduced amino acid sequences of the proteins was 51-61% identical to the corresponding proteins were previously studied in Buchnera of the aphid Schizaphis graminum. In this endosymbiont, trpEG is amplified and located on a plasmid, whereas, in the endosymbiont of S. chinensis, as in other eubacteria, trpEG occurs as a single copy on the bacterial chromosome. Implications of these findings for the evolution of this mutualistic association are discussed.}, }
@article {pmid7742973, year = {1995}, author = {Aksoy, S and Pourhosseini, AA and Chow, A}, title = {Mycetome endosymbionts of tsetse flies constitute a distinct lineage related to Enterobacteriaceae.}, journal = {Insect molecular biology}, volume = {4}, number = {1}, pages = {15-22}, doi = {10.1111/j.1365-2583.1995.tb00003.x}, pmid = {7742973}, issn = {0962-1075}, support = {AI-28778/AI/NIAID NIH HHS/United States ; AI-34033/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Biological Evolution ; DNA Primers ; Digestive System/*microbiology/ultrastructure ; Enterobacteriaceae/*classification ; Molecular Sequence Data ; Phylogeny ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Tsetse flies (Diptera: Glossinidae) harbour two morphologically different endosymbionts intracellularly associated with gut tissue: a primary (P) and a secondary (S) organism. The P-endosymbiont is a gram-negative rod, 8-10 microns in size, and resides intracellularly within specialized cells, mycetocytes which are organized into an organelle (mycetome), in the anterior portion of the gut. The S-endosymbiont is a smaller (1-2 microns) gram-negative rod and is harboured in the epithelial sheath cells in midgut. Phylogenetic characterization of S-endosymbionts from taxonomically distant insects including tsetse flies has shown that they are related to the free-living bacterium, Escherichia coli, and are members of the family Enterobacteriaceae within the gamma-3 subdivision of Proteobacteria. In this study, a polymerase chain reaction (PCR) based assay was designed utilizing the conserved sequences of 16S rDNA in order to phylogenetically characterize the mycetome-associated P-endosymbionts directly from tsetse mycetome tissue. Analysis from five species of flies representing the three major subgenera of genus Glossina indicates that P-endosymbionts constitute a distinct lineage within the gamma-3 subdivision of Proteobacteria. Mycetome endosymbiont phylogeny appears to parallel the classic taxonomic assignments independently developed for their insect host species. This suggests an ancient association for this symbiosis, which may have subsequently radiated with time, giving rise to the current species of tsetse flies and their modern-day endosymbionts. Based on endosymbiont phylogeny, the fusca flies constitute the most ancient subgenus, followed by the morsitans and palpalis groups.}, }
@article {pmid7736608, year = {1995}, author = {Gilson, PR and Adcock, GJ and Howlett, BJ and McFadden, GI}, title = {Organisation and sequence analysis of nuclear-encoded 5s ribosomal RNA genes in cryptomonad algae.}, journal = {Current genetics}, volume = {27}, number = {3}, pages = {239-242}, pmid = {7736608}, issn = {0172-8083}, mesh = {Base Sequence ; DNA, Ribosomal/*genetics ; Eukaryota/*genetics ; Molecular Sequence Data ; Polymerase Chain Reaction ; Polymorphism, Genetic ; RNA, Ribosomal, 5S/chemistry/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {Southern hybridisation, polymerase chain reaction (PCR), and nucleotide sequence, data indicate that the 5s ribosomal RNA (rRNA) gene is linked to the main rRNA gene repeat in the nuclear genome of four cryptomonad algae (Rhinomonas pauca, Storeatula major, Komma caudata, and isolate Cs 134). The 5s gene is apparently transcribed in the same direction as the large and small subunit rRNA genes. The intergenic spacer between the 5s gene and the large subunit rRNA gene exhibits length and sequence polymorphism among the different species. Cryptomonads contain two different eukaryotic genomes: the host nucleus and the nucleus of a eukaryotic endosymbiont. Mapping experiments with isolated chromosomes of the host and endosymbiont genomes showed that the intergenic spacer between the large subunit and the 5s rRNA gene, which was amplified from total DNA by PCR, was derived from the host nuclear genome.}, }
@article {pmid7574622, year = {1995}, author = {Kim, YW and Yasuda, M and Yamagishi, A and Oshima, T and Ohta, S}, title = {Characterization of the endosymbiont of a deep-sea bivalve, Calyptogena soyoae.}, journal = {Applied and environmental microbiology}, volume = {61}, number = {2}, pages = {823-827}, pmid = {7574622}, issn = {0099-2240}, mesh = {Animals ; Bacteria/classification/genetics/*isolation &amp; purification ; Base Sequence ; Bivalvia/*microbiology ; DNA Primers/genetics ; DNA Probes/genetics ; DNA, Bacterial/genetics ; Gills/microbiology ; In Situ Hybridization ; Molecular Sequence Data ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Sequence Homology, Nucleic Acid ; *Symbiosis ; }, abstract = {We have purified DNA from gill tissue of a marine bivalve, Calyptogena soyoae, collected from the deep-sea cold seep communities in Sagami Bay, Japan. An rRNA gene was amplified, cloned, and sequenced. In situ hybridization revealed that the sequence is that of a bacterial endosymbiont within the gill of C. soyoae.}, }
@article {pmid7538012, year = {1995}, author = {Aksoy, S}, title = {Molecular analysis of the endosymbionts of tsetse flies: 16S rDNA locus and over-expression of a chaperonin.}, journal = {Insect molecular biology}, volume = {4}, number = {1}, pages = {23-29}, doi = {10.1111/j.1365-2583.1995.tb00004.x}, pmid = {7538012}, issn = {0962-1075}, support = {AI-34033/AI/NIAID NIH HHS/United States ; AI028778/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/metabolism ; Base Sequence ; Chaperonins/*biosynthesis ; DNA, Bacterial/*genetics ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Gram-Negative Bacteria/*classification/genetics ; Molecular Sequence Data ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/*genetics ; *Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Based on 16S rDNA sequence comparison, intracellular mycetome-associated endosymbionts (P-endosymbionts) of tsetse flies (Diptera: Glossinidae) form a distinct lineage within the gamma-3 subdivision of proteobacteria, related to the free-living bacterium Escherichia coli, midgut S-endosymbionts of various insects including tsetse flies, and to the P-endosymbiont lineage of aphids, Buchnera aphidicola. Gene organization and expression of several loci in intracellular microorganisms have revealed differences from free-living bacteria. This study analyses two of these characteristics in tsetse endosymbionts; the copy number and gene organization of rDNA operations and the nature of the abundant protein(s) synthesized by these microorganisms. Results indicate that Glossina morsitans morsitans S-endosymbionts have multiple (seven) rDNA operons coding for 16S (rrs) followed by 23S (rrl) gene sequences, whereas tsetse P-endosymbionts have a single, similarly organized rDNA operon. In tsetse mycetocytes in vitro, P-endosymbionts synthesize a predominant protein of 60 kDa in size (p60) which by Western blot analysis shows immunological cross-reactivity with the abundant 63 kDa (p63) protein of B. aphidicola. p63 (also referred to as symbionin) has been characterized as a molecular chaperone, structurally and functionally similar to the groEL protein of E. coli. Under in vitro conditions, tsetse S-endosymbionts synthesize high levels of a similarly-sized protein that cross-reacts with p63 chaperonin. Antisera against the tsetse p60 protein also recognizes p63 protein of B. aphidicola, suggesting that the abundant tsetse endosymbiont protein is a chaperonin.}, }
@article {pmid7800041, year = {1995}, author = {Wade, MJ and Chang, NW}, title = {Increased male fertility in Tribolium confusum beetles after infection with the intracellular parasite Wolbachia.}, journal = {Nature}, volume = {373}, number = {6509}, pages = {72-74}, doi = {10.1038/373072a0}, pmid = {7800041}, issn = {0028-0836}, mesh = {Animals ; Female ; *Fertility ; Male ; Rickettsiaceae/*physiology ; Symbiosis ; Tribolium/genetics/microbiology/*physiology ; }, abstract = {The cytoplasmically inherited microorganism Wolbachia pipientis behaves like a sexually selected trait in its host, the flour beetle Tribolium confusum, enhancing male fertility at the expense of female fecundity. Here we show that infected females have fewer offspring than uninfected females but infected males have a large fertility advantage over uninfected males within multiply-inseminated infected or uninfected females. The male fertility effect accelerates the spread of the Wolbachia through the host population and expands the initial opportunity for hitch-hiking of host nuclear genes. Sperm competition in a host, mediated by endosymbionts, has not been previously described.}, }
@article {pmid8925499, year = {1995}, author = {Bull, L and Fogarty, TC}, title = {Artificial symbiogenesis.}, journal = {Artificial life}, volume = {2}, number = {3}, pages = {269-292}, doi = {10.1162/artl.1995.2.3.269}, pmid = {8925499}, issn = {1064-5462}, mesh = {Algorithms ; *Biological Evolution ; Computer Simulation ; Endocytosis ; Epistasis, Genetic ; Gene Transfer Techniques ; Genetics, Population ; Models, Theoretical ; *Symbiosis ; }, abstract = {Symbiosis is the phenomenon in which organisms of different species live together in close association, resulting in a raised level of fitness for one or more of the organisms. Symbiogenesis is the name given to the process by which symbiotic partners combine and unify-forming endosymbioses and then potentially transferring genetic material-giving rise to new morphologies and physiologies evolutionarily more advanced than their constitutents. In this article we begin by using the NKC model of coevolution to examine endosymbiosis and its effect on the evolutionary performance of the partners involved. We are then able to suggest the conditions under which endosymbioses are more likely to occur and why; we find they emerge between organisms within a window of their respective "chaotic gas regimes" and hence that the association represents a more stable state for the partners. The conditions under which gene transfer is more likely to represent an advantage for such endosymbionts are then examined within the same model. We find that, providing a suitable pathway exists, such a process can lead to a more efficient genetic configuration for the symbionts within a window that overlaps that in which endosymbioses occur. Finally, the results are used as grounds for implementing symbiogenesis within artificial evolutionary multiagent systems.}, }
@article {pmid8561471, year = {1995}, author = {Baumann, P and Baumann, L and Lai, CY and Rouhbakhsh, D and Moran, NA and Clark, MA}, title = {Genetics, physiology, and evolutionary relationships of the genus Buchnera: intracellular symbionts of aphids.}, journal = {Annual review of microbiology}, volume = {49}, number = {}, pages = {55-94}, doi = {10.1146/annurev.mi.49.100195.000415}, pmid = {8561471}, issn = {0066-4227}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/genetics ; *Bacterial Physiological Phenomena ; *Biological Evolution ; Symbiosis/*physiology ; }, abstract = {Evolutionary studies suggest that 200-250 million years ago an aphid ancestor was infected with a free-living eubacterium. The latter became established within aphid cells. Host and endosymbiont (genus Buchnera) became interdependent and unable to survive without each other. The growth of Buchnera became integrated with that of the aphids, which acquired the endosymbionts from their mothers before birth. Speciation of host lineages was paralleled by divergence of associated endosymbiont lineages, resulting in parallel evolution of Buchnera and aphids. Present day Buchnera retains many of the properties of its free-living ancestor, containing genes for proteins involved in DNA replication, transcription, and translation, as well as chaperonins and proteins involved in secretion, energy-yielding metabolism, and amino acid biosynthesis. Some of these processes are also observed in isolated endosymbiont cells. Genetic and physiological studies indicate that Buchnera can synthesize methionine, cysteine, and tryptophan and supply these amino acids to the aphid host. In the case of some fast-growing species of aphids, the overproduction of tryptophan by Buchnera involves plasmid-amplification of the gene coding for anthranilate synthase, the first enzyme of the tryptophan biosynthetic pathway. These recent studies provide a beginning in our understanding of Buchnera and its role in the endosymbiosis with aphids.}, }
@article {pmid7731932, year = {1995}, author = {Yagita, K and Matias, RR and Yasuda, T and Natividad, FF and Enriquez, GL and Endo, T}, title = {Acanthamoeba sp. from the Philippines: electron microscopy studies on naturally occurring bacterial symbionts.}, journal = {Parasitology research}, volume = {81}, number = {2}, pages = {98-102}, pmid = {7731932}, issn = {0932-0113}, mesh = {Acanthamoeba/classification/physiology/*ultrastructure ; Animals ; Bacteria/ultrastructure ; Bacterial Physiological Phenomena ; DNA, Mitochondrial/*isolation &amp; purification ; DNA, Protozoan/*isolation &amp; purification ; Electrophoresis, Agar Gel ; Fresh Water ; Lysosomes/ultrastructure ; Microscopy, Electron ; Organelles/ultrastructure ; Phagocytosis ; Philippines ; Plasmids/analysis ; Polymerase Chain Reaction ; Ribosomes/ultrastructure ; Symbiosis ; }, abstract = {The isolation of two plasmid-like circular DNAs, measuring 52 and 42 kbp, from an Acanthamoeba sp. from the Philippines has led to the demonstration of a bacterial endosymbiont occurring in this free-living amoeba. The 52-kbp band hybridized with a short sequence of cytochrome b gene and was identified as the mitochondrial DNA, whereas the 42-kbp band was identified as plasmid DNA of the bacterial symbionts on the basis of electron microscopy. The endosymbionts are gram-negative, rod-shaped bacteria measuring approximately 1.3 x 0.43 microns and numbering about eight to ten cells per section. They are randomly distributed in both cysts and trophozoites and are surrounded neither by a phagolysosomal membrane nor by a clear or electron-translucent region. The endosymbiont membrane appears to have a close association with ribosomes, which are seen to be more concentrated within the vicinity of the symbionts than elsewhere within the cytoplasm. Attempts to grow the symbionts and the amoebae separately have failed.}, }
@article {pmid7809132, year = {1994}, author = {Karlin, S and Campbell, AM}, title = {Which bacterium is the ancestor of the animal mitochondrial genome?.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {26}, pages = {12842-12846}, pmid = {7809132}, issn = {0027-8424}, support = {GM10452-30/GM/NIGMS NIH HHS/United States ; GM51117/GM/NIGMS NIH HHS/United States ; HG00335-07/HG/NHGRI NIH HHS/United States ; }, mesh = {Base Composition ; Biological Evolution ; DNA, Bacterial/*genetics ; DNA, Mitochondrial/*genetics ; Mycoplasma/*genetics ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Sulfolobus/*genetics ; }, abstract = {We present considerable data supporting the hypothesis that a Sulfolobus- or Mycoplasma-like endosymbiont, rather than an alpha-proteobacterium, is the ancestor of animal mitochondrial genomes. This hypothesis is based on pronounced similarities in oligonucleotide relative abundance extremes common to animal mtDNA, Sulfolobus, and Mycoplasma capricolum and pronounced discrepancies of these relative abundance values with respect to alpha-proteobacteria. In addition, genomic dinucleotide relative abundance measures place Sulfolobus and M. capricolum among the closest to animal mitochondrial genomes, whereas the classical eubacteria, especially the alpha-proteobacteria, are at excessive distances. There are also considerable molecular and cellular phenotypic analogies among mtDNA, Sulfolobus, and M. capricolum.}, }
@article {pmid7821795, year = {1994}, author = {Müller, SB and Rensing, SA and Maier, UG}, title = {The cryptomonad histone H4-encoding gene: structure and chromosomal localization.}, journal = {Gene}, volume = {150}, number = {2}, pages = {299-302}, doi = {10.1016/0378-1119(94)90441-3}, pmid = {7821795}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Blotting, Northern ; Blotting, Southern ; Cell Nucleus/metabolism ; *Chromosome Mapping ; DNA, Protozoan/analysis/genetics ; Eukaryota/*genetics ; *Genes, Protozoan ; Histones/*genetics ; Intracellular Membranes/metabolism ; Molecular Sequence Data ; RNA, Protozoan/biosynthesis ; Ribosomes/metabolism ; }, abstract = {Cryptomonads are unicellular flagellates whose plastids are surrounded by four membranes. A periplastidal compartment, containing eukaryote-type ribosomes, starch grains and a so-called nucleomorph, is located between the inner and outer membrane pairs. The nucleomorph has been shown to be the vestigial nucleus of a eukaryotic endosymbiont. In order to obtain more information about the chromatin structure of the nucleomorph and the host nuclear chromosomes, we studied the distribution of the histone, H4. H4 was not detectable in the nucleomorph by immunolocalization, thus supporting earlier findings by Gibbs [In: Wiesner et al. (Eds.), Experimental Phycology 1, 1990, pp. 145-157]. Likewise, no H4 DNA was demonstrable in the nucleomorph by Southern hybridization. Sequence analysis, and Southern and Northern blot data of a cryptomonad gene, H4, indicate an intermediate position for these genes between animals and plants.}, }
@article {pmid7529016, year = {1994}, author = {Polz, MF and Distel, DL and Zarda, B and Amann, R and Felbeck, H and Ott, JA and Cavanaugh, CM}, title = {Phylogenetic analysis of a highly specific association between ectosymbiotic, sulfur-oxidizing bacteria and a marine nematode.}, journal = {Applied and environmental microbiology}, volume = {60}, number = {12}, pages = {4461-4467}, pmid = {7529016}, issn = {0099-2240}, mesh = {Animals ; Base Sequence ; DNA Probes ; Gram-Negative Bacteria/classification/*isolation &amp; purification/ultrastructure ; Molecular Sequence Data ; Nematoda/*microbiology ; Oxidation-Reduction ; *Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Analysis, RNA ; Sulfur/metabolism ; *Symbiosis ; }, abstract = {The phylogenetic relationship of chemoautotrophic, sulfur-oxidizing, ectosymbiotic bacteria growing on a marine nematode, a Laxus sp. (formerly a Catanema sp.), to known endosymbionts and free-living bacteria was determined. Comparative 16S rRNA sequencing was used to investigate the unculturable nematode epibionts, and rRNA-targeted oligonucleotide hybridization probes were used to identify the ectosymbionts in situ. Both analyses revealed a remarkably specific and stable symbiosis. Unique hybridization of a specific probe to the ectosymbionts indicated that only one species of bacteria was present and growing on the cuticle of the nematode. Distance and parsimony methods used to infer phylogenetic trees both placed the nematode ectosymbionts at the base of a branch containing chemoautotrophic, sulfur-oxidizing endosymbionts of three bivalve families and of the tube worm Riftia pachyptila. The most closely related free-living bacteria were chemoautotrophic sulfur oxidizers belonging to the genus Thiomicrospira. Furthermore, our results suggested that a second, only distantly related group of thioautotrophic endosymbionts has as its deepest branch surface-colonizing bacteria belonging to the genus Thiothrix, some of which are capable of sulfur-oxidizing chemoautotrophic growth.}, }
@article {pmid7972066, year = {1994}, author = {Cavalier-Smith, T and Allsopp, MT and Chao, EE}, title = {Chimeric conundra: are nucleomorphs and chromists monophyletic or polyphyletic?.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {24}, pages = {11368-11372}, pmid = {7972066}, issn = {0027-8424}, mesh = {Animals ; Base Sequence ; Eukaryota/*genetics ; Fungi/*genetics ; Molecular Sequence Data ; Phylogeny ; Plants/*genetics ; RNA, Ribosomal, 18S/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {All algae with chloroplasts located not freely in the cytosol, but inside two extra membranes, probably arose chimerically by the permanent fusion of two different eukaryote cells: a protozoan host and a eukaryotic algal symbiont. Two such groups, cryptomonads (phylum Cryptista) and Chlorarachniophyta, still retain a DNA-containing relic of the nucleus of the algal endosymbiont, known as the nucleomorph, as well as the host nucleus. These two phyla were traditionally assumed to have obtained their chloroplasts separately by two independent symbioses. We have sequenced the nuclear and the nucleomorph 18S rRNA genes of the nonphotosynthetic cryptomonad Chilomonas paramecium. Our phylogenetic analysis suggests that cryptomonad and chlorarachniophyte nucleomorphs may be related to each other and raises the possibility that both phyla may have diverged from a common ancestral chimeric cell that originated by a single endosymbiosis involving an algal endosymbiont related to the ancestor of red algae. But, because of the instability of the molecular trees when different taxa are added, there is insufficient evidence to overturn the traditional view that Chlorarachnion nucleomorphs evolved separately from a relative of green algae. The four phyla that contain chromophyte algae (those with chlorophyll c--i.e., Cryptista, Heterokonta, Haptophyta, Dinozoa) are distantly related to each other and to Chlorarachniophyta on our trees. However, all of the photosynthetic taxa within each of these four phyla radiate from each other very substantially after the radiation of the four phyla themselves. This favors the view that the common ancestor of these four phyla was not photosynthetic and that chloroplasts were implanted separately into each much more recently. This probable polyphyly of the chromophyte algae, if confirmed, would make it desirable to treat Cryptista, Heterokonta, and Haptophyta as separate kingdoms, rather than to group them together in the single kingdom Chromista.}, }
@article {pmid7973633, year = {1994}, author = {Yuan, J and Henry, R and McCaffery, M and Cline, K}, title = {SecA homolog in protein transport within chloroplasts: evidence for endosymbiont-derived sorting.}, journal = {Science (New York, N.Y.)}, volume = {266}, number = {5186}, pages = {796-798}, doi = {10.1126/science.7973633}, pmid = {7973633}, issn = {0036-8075}, support = {1 R01 GM46951/GM/NIGMS NIH HHS/United States ; }, mesh = {Adenosine Triphosphatases/metabolism ; Azides/pharmacology ; Bacterial Proteins/metabolism ; Base Sequence ; Biological Transport/drug effects ; Carrier Proteins/chemistry/isolation &amp; purification/*metabolism ; Chloroplast Proteins ; Chloroplasts/*metabolism ; *Escherichia coli Proteins ; Intracellular Membranes/metabolism ; *Membrane Proteins ; *Membrane Transport Proteins ; Molecular Sequence Data ; Peas ; Photosynthetic Reaction Center Complex Proteins/*metabolism ; *Photosystem II Protein Complex ; Plant Proteins/chemistry/isolation &amp; purification/*metabolism ; Plastocyanin/*metabolism ; SEC Translocation Channels ; SecA Proteins ; Sodium Azide ; Symbiosis ; }, abstract = {The SecA protein is an essential, azide-sensitive component of the bacterial protein translocation machinery. A SecA protein homolog (CPSecA) now identified in pea chloroplasts was purified to homogeneity. CPSecA supported protein transport into thylakoids, the chloroplast internal membrane network, in an azide-sensitive fashion. Only one of three pathways for protein transport into thylakoids uses the CPSecA mechanism. The use of a bacteria-homologous mechanism in intrachloroplast protein transport provides evidence for conservative sorting of proteins within chloroplasts.}, }
@article {pmid7896735, year = {1994}, author = {Morioka, M and Muraoka, H and Yamamoto, K and Ishikawa, H}, title = {An endosymbiont chaperonin is a novel type of histidine protein kinase.}, journal = {Journal of biochemistry}, volume = {116}, number = {5}, pages = {1075-1081}, doi = {10.1093/oxfordjournals.jbchem.a124630}, pmid = {7896735}, issn = {0021-924X}, mesh = {Adenosine Diphosphate/metabolism ; Adenosine Triphosphate/metabolism ; Animals ; Aphids/microbiology ; Bacterial Proteins/*chemistry ; Binding Sites ; Chaperonins/*chemistry ; Histidine/*chemistry ; Phosphorus Radioisotopes ; Phosphorylation ; }, abstract = {Symbionin, a GroEL homologous molecular chaperone produced by an intracellular symbiont of the pea aphid, is able to transfer its high-energy phosphate bond to other compounds through its autophosphorylation. When the urea-dissociated monomeric symbionin fixed onto a polyvinylidene difluoride membrane was incubated with [gamma-32P] ATP, it was efficiently phosphorylated at elevated temperatures. The autophosphorylated monomeric 32P-labeled symbionin, when incubated with ADP, transferred a significant portion of its radioactivity to ADP, suggesting that the autocatalytically phosphorylated monomeric symbionin contains high-energy phosphate bonds. It was also shown that when symbiotic proteins were electrophoretically separated, blotted onto a polyvinylidene disulfide membrane and incubated with 32P-labeled symbionin, radioactivity was found on several kinds of polypeptides, indicating that the phosphoryl group was transferred from symbionin to other symbiotic proteins. Peptide sequence analysis and thin-layer chromatographic analysis of the 32P-labeled tryptic fragment of the phosphorylated symbionin revealed that the site of phosphorylation is His-133. These results suggested that symbionin functions as a histidine protein kinase, or a sensor molecule, of the two-component pathway known in other organisms. However, symbionin is not similar in amino acid sequence to any known histidine protein kinase.}, }
@article {pmid7874738, year = {1994}, author = {Rensing, SA and Goddemeier, M and Hofmann, CJ and Maier, UG}, title = {The presence of a nucleomorph hsp70 gene is a common feature of Cryptophyta and Chlorarachniophyta.}, journal = {Current genetics}, volume = {26}, number = {5-6}, pages = {451-455}, pmid = {7874738}, issn = {0172-8083}, mesh = {Blotting, Southern ; Chromosomes ; DNA Probes ; DNA, Ribosomal/isolation &amp; purification ; Eukaryota/*genetics/metabolism ; *Genes, Plant ; HSP70 Heat-Shock Proteins/*genetics ; Karyotyping ; Species Specificity ; }, abstract = {Cryptomonad algae and Chlorarachniophyta are evolutionary chimaeras derived from the engulfment of an eukaryotic phototrophic endosymbiont by a eukaryotic host cell. Although much reduced, the endosymbiont's eukaryotic plasmatic compartment still contains a nucleus, the so-called nucleomorph. These nucleomorphs carry the smallest known eukaryotic genomes. We have characterized the genomes of several cryptomonads and a Chlorarachnion species by means of PFGE (pulsed-field gel electrophoresis). Hybridization studies with small subunit rDNA were used to identify the nucleomorph chromosomes. We also performed hybridization experiments with an hsp70 probe to estimate the distribution of this gene among the different algal species. The evolutionary, genetical, and physiological implications of our studies are discussed. A model on the possible function of the nucleomorph hsp70 gene products is presented.}, }
@article {pmid7535631, year = {1994}, author = {Rouhbakhsh, D and Moran, NA and Baumann, L and Voegtlin, DJ and Baumann, P}, title = {Detection of Buchnera, the primary prokaryotic endosymbiont of aphids, using the polymerase chain reaction.}, journal = {Insect molecular biology}, volume = {3}, number = {4}, pages = {213-217}, doi = {10.1111/j.1365-2583.1994.tb00169.x}, pmid = {7535631}, issn = {0962-1075}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/genetics/*isolation &amp; purification ; Base Sequence ; DNA Primers ; DNA, Complementary/genetics ; *Genes, Bacterial ; Genetic Linkage ; Molecular Sequence Data ; Operon ; *Polymerase Chain Reaction ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/*genetics ; RNA, Ribosomal, 23S/*genetics ; Symbiosis ; }, abstract = {Members of the genus Buchnera constitute a distinct prokaryotic lineage containing the primary endosymbionts of aphids (Homoptera: Aphidoidea). Using synthetic oligonucleotides in conjunction with the polymerase chain reaction, we propose three approaches for the identification of members of this genus. The first is based on unique sequences within rrs (gene coding for 16S ribosomal RNA). The second is based on a different and unique organization of the ribosomal RNA operons of Buchnera and the close proximity of aroE upstream of rrl (gene coding for 23S rRNA). The third is based on the linkage relationship of argS which is upstream of rrs. Validation of these three approaches requires their more extensive application.}, }
@article {pmid7931143, year = {1994}, author = {van den Heuvel, JF and Verbeek, M and van der Wilk, F}, title = {Endosymbiotic bacteria associated with circulative transmission of potato leafroll virus by Myzus persicae.}, journal = {The Journal of general virology}, volume = {75 (Pt 10)}, number = {}, pages = {2559-2565}, doi = {10.1099/0022-1317-75-10-2559}, pmid = {7931143}, issn = {0022-1317}, mesh = {Amino Acid Sequence ; Animals ; Anti-Bacterial Agents/pharmacology ; Aphids/*microbiology ; Bacteria/drug effects ; *Bacterial Physiological Phenomena ; Bacterial Proteins/analysis/*biosynthesis/isolation &amp; purification ; Carrier Proteins/analysis/biosynthesis/isolation &amp; purification ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Female ; Insect Vectors ; Luteovirus/*physiology ; Microscopy, Immunoelectron ; Molecular Sequence Data ; Solanum tuberosum/*microbiology ; Symbiosis ; }, abstract = {In order to understand the molecular mechanisms underlying circulative transmission of potato leafroll virus (PLRV) by aphids, we screened Myzus persicae proteins as putative PLRV binding molecules using a virus overlay assay of protein blots. In this way, we found that purified PLRV particles exhibited affinity for five aphid proteins. The one most readily detected has an M(r) of 63K, and was identified as symbionin. This is the predominant protein synthesized by the bacterial endosymbiont of the aphid and is released into the haemolymph. Since further studies clearly showed that PLRV particles also bind to native symbionin, it was envisaged that virus particles when acquired into the haemocoel of an aphid interact with symbionin. Inhibition of prokaryotic protein synthesis by feeding M. persicae nymphs on an antibiotic-containing artificial diet prior to PLRV acquisition reduced virus transmission by more than 70%. The major coat protein of the virus was found to be degraded in the antibiotic-treated aphids; this would obviously have resulted in an increased exposure of viral RNA to enzymic breakdown and concomitant loss of infectivity. For these reasons we conclude that endosymbiotic bacteria play a crucial role in determining the persistent nature of PLRV in the aphid haemolymph and that symbionin is probably the key protein in this interaction.}, }
@article {pmid7521530, year = {1994}, author = {Du, Y and Maslov, DA and Chang, KP}, title = {Monophyletic origin of beta-division proteobacterial endosymbionts and their coevolution with insect trypanosomatid protozoa Blastocrithidia culicis and Crithidia spp.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {18}, pages = {8437-8441}, pmid = {7521530}, issn = {0027-8424}, support = {AI20486/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; *Crithidia/genetics ; DNA Primers/chemistry ; DNA, Bacterial/genetics ; DNA, Ribosomal/*genetics ; *Genes, Bacterial ; Genes, Protozoan ; Molecular Sequence Data ; Nucleic Acid Conformation ; Phylogeny ; RNA, Bacterial/genetics ; RNA, Ribosomal, 18S/genetics ; Sequence Alignment ; Sequence Homology, Nucleic Acid ; Symbiosis ; *Trypanosomatina/genetics ; }, abstract = {Some trypanosomatid protozoa (order Kinetoplastida) are well known to harbor bacterial endosymbionts. Their phylogenetic positions and evolutionary relationships with the hosts were deduced by comparing the rRNA gene sequences. Earlier, we observed that these symbionts from three Crithidia spp. are identical and are closely related to Bordetella bronchiseptica. We have now sequenced the genes of another endosymbiont and the host protozoan Blastocrithidia culicis. The 16S rRNA genes of the Blastocrithidia and Crithidia symbionts share approximately 97% identity and form a distinct group, branching off the B. bronchiseptica lineage in the beta-division of Proteobacteria. Comparison of their secondary structures in the stem regions suggests compensatory mutations of the symbiont sequences, contributing to their biased base transitions from G to A and C to T. Two putative genes encoding tRNA(Ile) and tRNA(Ala) are highly conserved in the otherwise variable internal transcribed spacer region. Comparisons of the host rRNA gene sequences suggest that the symbiont-containing Crithidia and Blastocrithidia are more akin to each other than to other trypanosomatids. The evidence suggests that Blastocrithidia and Crithidia symbionts descend from a common ancestor, which had presumably entered an ancestral host and thence coevolved with it into different species. We therefore propose naming the symbionts Kinetoplastibacterium blastocrithidii and Kinetoplastibacterium crithidii.}, }
@article {pmid8001167, year = {1994}, author = {Ohta, N and Kawano, S and Kuroiwa, T}, title = {Physical map of the plastid genome of the unicellular red alga Cyanidium caldarium strain RK-1.}, journal = {Current genetics}, volume = {26}, number = {2}, pages = {136-138}, pmid = {8001167}, issn = {0172-8083}, mesh = {Amino Acid Sequence ; Base Sequence ; Genes, Plant ; *Genome ; Molecular Sequence Data ; *Plastids ; Repetitive Sequences, Nucleic Acid ; Restriction Mapping ; Rhodophyta/*genetics ; Sequence Homology, Amino Acid ; Thioredoxins/chemistry/genetics ; }, abstract = {The physical map of the plasmid genome of the unicellular red alga Cyanidium caldarium strain RK-1 was constructed. The 150-kbp genome was circular and had an inverted repeated region (IR) which contained the genes for 16 s and 23 s ribosomal RNAs, as is usually seen in most plastid genomes. Since C. caldarium is a very "primitive" alga, the results suggest that the ancestral cyanobacteria lost most of its genome as an endosymbiont comparatively early in the process of plastid formation. After that, several genes seem to have been lost from plastid genomes, step by step, during the course of evolution.}, }
@article {pmid7981970, year = {1994}, author = {Kannenberg, EL and Brewin, NJ}, title = {Host-plant invasion by Rhizobium: the role of cell-surface components.}, journal = {Trends in microbiology}, volume = {2}, number = {8}, pages = {277-283}, doi = {10.1016/0966-842x(94)90004-3}, pmid = {7981970}, issn = {0966-842X}, mesh = {Bacterial Adhesion ; Fabaceae/*microbiology ; Host-Parasite Interactions ; Plant Roots/physiology ; *Plants, Medicinal ; Polysaccharides, Bacterial/*physiology ; Rhizobium/growth &amp; development/*physiology ; Symbiosis/physiology ; }, abstract = {Rhizobia are soil bacteria that can become endosymbionts, reducing atmospheric nitrogen within nodules formed on the roots of legume plants. During tissue and cell invasion, bacterial cell-surface components adapt the bacterium to survive as an endophyte without eliciting host-defence responses. The structures of many of these components have been established recently, allowing their possible roles in invasion to be defined more clearly.}, }
@article {pmid7932778, year = {1994}, author = {Knoop, V and Brennicke, A}, title = {Promiscuous mitochondrial group II intron sequences in plant nuclear genomes.}, journal = {Journal of molecular evolution}, volume = {39}, number = {2}, pages = {144-150}, pmid = {7932778}, issn = {0022-2844}, mesh = {Base Sequence ; DNA, Complementary ; DNA, Mitochondrial/*genetics/metabolism ; Genome, Plant ; Introns/*genetics ; Molecular Sequence Data ; NADH Dehydrogenase/genetics ; *Plants, Toxic ; Polymerase Chain Reaction ; Tobacco/*genetics ; }, abstract = {Gene translocations from the organelles to the nucleus are postulated by the endosymbiont hypothesis. We here report evidence for sequence insertions in the nuclear genomes of plants that are derived from noncoding regions of the mitochondrial genome. Fragments of mitochondrial group II introns are identified in the nuclear genomes of tobacco and a bean species. The duplicated intron sequences of 75-140 bp are derived from cis- and trans-splicing introns of genes encoding subunits 1 and 5 of the NADH dehydrogenase. The mitochondrial sequences are inserted in the vicinities of a lectin gene, different glucanase genes and a gene encoding a subunit of photosystem II. Sequence similarities between the nuclear and mitochondrial copies are in the range of 80 to 97%, suggesting recent transfer events that occurred in the basic glucanase genes before and in the lectin gene after the gene duplications in the evolution of the nuclear gene families. Overlapping regions of the same introns are in two instances also involved in intramitochondrial sequence duplications.}, }
@article {pmid7914923, year = {1994}, author = {Soltys, BJ and Gupta, RS}, title = {Presence and cellular distribution of a 60-kDa protein related to mitochondrial hsp60 in Giardia lamblia.}, journal = {The Journal of parasitology}, volume = {80}, number = {4}, pages = {580-590}, pmid = {7914923}, issn = {0022-3395}, mesh = {Animals ; Antibodies, Monoclonal/immunology ; Antibodies, Protozoan/immunology ; Blotting, Western ; Chaperonin 60 ; Cross Reactions ; DNA, Protozoan/analysis ; Electrophoresis, Polyacrylamide Gel ; Fluorescent Antibody Technique ; Giardia lamblia/*chemistry/genetics/ultrastructure ; Heat-Shock Proteins/*analysis/immunology ; Microscopy, Immunoelectron ; Protozoan Proteins/*analysis/immunology ; }, abstract = {Giardia lamblia trophozoites contain a 60-kDa protein recognized in immunoblots by antibody to mammalian hsp60, a protein localized in mitochondria in eukaryotic cells. The cellular distribution of this protein is evaluated by immunofluorescence microscopy using monoclonal antibody to human hsp60, polyclonal antibody to rodent hsp60, and 2 monoclonal antibodies to mycobacterial 65-kDa antigen, a prokaryotic hsp60 homolog. All of these antibodies, except 1, which is specific for prokaryotic hsp60, give a punctate labeling pattern throughout the cytoplasm, indicating that the 60-kDa protein is concentrated at discrete sites in the cytoplasm. The polyclonal hsp60 antiserum reveals additional punctate labeling colocalized on axonemes of the anterior flagella. Postembedment immunogold labeling and electron microscopy confirm that the antigen is clustered at foci in the cytoplasm but show no evidence of association with a membranous organelle. The hsp60 reactivity is also observed on anterior axonemes within the cytoplasm and on the adhesive disc. Hoechst 33258 DNA staining as well as electron microscopy give no evidence of endosymbionts, so a false positive due to a prokaryotic hsp60 homolog is unlikely. The presence of an hsp60-related protein in G. lamblia raises interesting questions concerning its origin.}, }
@article {pmid7529723, year = {1994}, author = {Lloyd, D and Ralphs, J and Durrant, L and Williams, AG and Amann, R}, title = {Studies of the bacterial endosymbionts of "anaerobic protozoa" using fluorescently-labelled rRNA-targetted oligonucleotide probes.}, journal = {Biochemical Society transactions}, volume = {22}, number = {3}, pages = {323S}, doi = {10.1042/bst022323s}, pmid = {7529723}, issn = {0300-5127}, mesh = {Anaerobiosis ; Animals ; Archaea/genetics/isolation &amp; purification/metabolism ; Bacteria/genetics/*isolation &amp; purification/metabolism ; Base Sequence ; Ciliophora/metabolism/*microbiology ; DNA Probes/genetics/metabolism ; Euryarchaeota/genetics/isolation &amp; purification ; Hydrogen/metabolism ; Methane/metabolism ; Molecular Sequence Data ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; Rumen/microbiology/parasitology ; Symbiosis ; }, }
@article {pmid8090791, year = {1994}, author = {Bandi, C and Damiani, G and Magrassi, L and Grigolo, A and Fani, R and Sacchi, L}, title = {Flavobacteria as intracellular symbionts in cockroaches.}, journal = {Proceedings. Biological sciences}, volume = {257}, number = {1348}, pages = {43-48}, doi = {10.1098/rspb.1994.0092}, pmid = {8090791}, issn = {0962-8452}, mesh = {Animals ; Bacteria/genetics ; Base Sequence ; Biological Evolution ; Cockroaches/*microbiology ; DNA Primers ; DNA, Ribosomal/chemistry/*genetics ; Flavobacterium/genetics/isolation &amp; purification/*physiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*genetics ; *Symbiosis ; }, abstract = {Animal cells are the sole habitat for a variety of bacteria. Molecular sequence data have been used to position a number of these intracellular microorganisms in the overall scheme of eubacterial evolution. Most of them have been classified as proteobacteria or chlamydiae. Here we present molecular evidence placing an intracellular symbiont among the flavobacteria-bacteroides. This microorganism inhabits specialized cells in the cockroach fat body and has been described as a mutualistic endosymbiont of uncertain phylogenetic position. The small subunit ribosomal DNA of these bacteria was analysed after polymerase chain reaction amplification to investigate their phylogeny. The endosymbionts of five species of cockroaches were found to make up a coherent group with no close relatives within the eubacterial phylum defined by the flavobacteria. In addition, the relationships among the endosymbionts, as revealed by DNA sequence data, appeared to be congruent with the host taxonomic relationships. Based on the host fossil record, a tentative calibration of the nucleotide substitution rate for the cockroach flavobacteria gave results congruent with those obtained for the aphid endosymbiotic proteobacteria.}, }
@article {pmid8208251, year = {1994}, author = {Hofmann, CJ and Rensing, SA and Häuber, MM and Martin, WF and Müller, SB and Couch, J and McFadden, GI and Igloi, GL and Maier, UG}, title = {The smallest known eukaryotic genomes encode a protein gene: towards an understanding of nucleomorph functions.}, journal = {Molecular &amp; general genetics : MGG}, volume = {243}, number = {5}, pages = {600-604}, pmid = {8208251}, issn = {0026-8925}, mesh = {Biological Transport ; Cell Membrane ; Electrophoresis, Gel, Pulsed-Field ; Eukaryota/*genetics ; Eukaryotic Cells ; *Genes, Plant ; Genomic Library ; Heat-Shock Proteins/biosynthesis/*genetics ; *Organelles ; Phylogeny ; Plant Proteins/*genetics ; Plastids ; Proteins/metabolism ; Sequence Homology, Amino Acid ; Symbiosis/*physiology ; }, abstract = {Cryptomonads are unicellular algae with plastids surrounded by four membranes. Between the two pairs of membranes lies a periplastidal compartment that harbours a DNA-containing organelle, termed the nucleomorph. The nucleomorph is the vestigial nucleus of a phototrophic, eukaryotic endosymbiont. Subcloning of parts of one nucleomorph chromosome revealed a gene coding for an Hsp70 protein. We demonstrate the expression of this nucleomorph protein-coding gene and present a model for protein transport from the host to the endosymbiont compartment.}, }
@article {pmid8206850, year = {1994}, author = {Laue, BE and Nelson, DC}, title = {Characterization of the gene encoding the autotrophic ATP sulfurylase from the bacterial endosymbiont of the hydrothermal vent tubeworm Riftia pachyptila.}, journal = {Journal of bacteriology}, volume = {176}, number = {12}, pages = {3723-3729}, pmid = {8206850}, issn = {0021-9193}, mesh = {Adenosine Triphosphate/*metabolism ; Amino Acid Sequence ; Animals ; Bacteria/enzymology/*genetics ; Base Sequence ; Cloning, Molecular ; Genes, Bacterial/*genetics ; Hot Temperature ; Molecular Sequence Data ; Nucleic Acid Probes ; Oceans and Seas ; Polychaeta/*microbiology ; Polymerase Chain Reaction ; Restriction Mapping ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sulfate Adenylyltransferase/*genetics ; Sulfur/metabolism ; Symbiosis/*genetics ; }, abstract = {ATP sulfurylase is a key enzyme in the energy-generating sulfur oxidation pathways of many chemoautotrophic bacteria. The utilization of reduced sulfur compounds to fuel CO2 fixation by the still-uncultured bacterial endosymbionts provides the basis of nutrition in invertebrates, such as the tubeworm Riftia pachyptila, found at deep-sea hydrothermal vents. The symbiont-containing trophosome tissue contains high levels of ATP sulfurylase activity, facilitating the recent purification of the enzyme. The gene encoding the ATP sulfurylase from the Riftia symbiont (sopT) has now been cloned and sequenced by using the partial amino acid sequence of the purified protein. Characterization of the sopT gene has unequivocally shown its bacterial origin. This is the first ATP sulfurylase gene to be cloned and sequenced from a sulfur-oxidizing bacterium. The deduced amino acid sequence was compared to those of ATP sulfurylases reported from organisms which assimilate sulfate, resulting in the discovery that there is substantial homology with the Saccharomyces cerevisiae MET3 gene product but none with the products of the cysDN genes from Escherichia coli nor with the nodP and nodQ genes from Rhizobium meliloti. This and emerging evidence from other sources suggests that E. coli may be atypical, even among prokaryotic sulfate assimilators, in the enzyme it employs for adenosine 5'-phosphosulfate formation. The sopT gene probe also was shown to specifically identify chemoautotrophic bacteria which utilize ATP sulfurylase to oxidize sulfur compounds.}, }
@article {pmid8206833, year = {1994}, author = {Heruth, DP and Pond, FR and Dilts, JA and Quackenbush, RL}, title = {Characterization of genetic determinants for R body synthesis and assembly in Caedibacter taeniospiralis 47 and 116.}, journal = {Journal of bacteriology}, volume = {176}, number = {12}, pages = {3559-3567}, pmid = {8206833}, issn = {0021-9193}, support = {1R15 GM46045-01/GM/NIGMS NIH HHS/United States ; GM36293/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Animals ; Bacteria/*genetics ; Bacterial Proteins/biosynthesis/*genetics/isolation &amp; purification ; Base Sequence ; Cloning, Molecular ; Escherichia coli/genetics ; Genes, Bacterial/*genetics ; Genetic Code ; Inclusion Bodies/*physiology ; Isoelectric Point ; Molecular Sequence Data ; Molecular Weight ; Paramecium tetraurelia/microbiology ; Protein Conformation ; Recombinant Proteins/biosynthesis ; Sequence Analysis, DNA ; Sequence Deletion ; Sequence Homology ; Symbiosis ; }, abstract = {Caedibacter taeniospiralis, an obligate bacterial endosymbiont of Paramecium tetraurelia, confers a killing trait upon its host paramecium. Type 51 R bodies (refractile inclusion bodies) are synthesized by these endosymbionts and are required for expression of the killing trait. The nucleotide sequence of the genetic determinants for type 51 R body synthesis and assembly was determined for C. taeniospiralis 47 and 116. Three independently transcribed genes (rebA, rebB, and rebC) were characterized. To date these are the only genes from C. taeniospiralis to be sequenced and characterized. DNA regulatory regions are recognized by Escherichia coli, and codon usage appears similar to that in E. coli. A fourth open reading frame with appropriate regulatory sequences was found within the reb locus, but no evidence was obtained to suggest that this putative gene is expressed in E. coli. The R body-encoding sequences from both strains are identical. Two-dimensional gel electrophoresis of deletion derivatives shows that two polymerization events are involved in R body assembly. One polymerization event requires only RebB and RebC; the other requires all three proteins. Expression of RebC is necessary for the posttranslational modification of RebA and RebB into species with three and two different molecular weights, respectively. In the presence of RebC, each species of RebB with a different molecular weight has six different isoelectric points.}, }
@article {pmid7922376, year = {1994}, author = {Karr, TL}, title = {Cytoplasmic incompatibility. Giant steps sideways.}, journal = {Current biology : CB}, volume = {4}, number = {6}, pages = {537-540}, doi = {10.1016/s0960-9822(00)00118-4}, pmid = {7922376}, issn = {0960-9822}, mesh = {Animals ; Cytoplasm/microbiology ; Female ; Insecta/*microbiology/physiology ; Male ; Pest Control, Biological ; Reproduction ; Rickettsiaceae/*physiology ; Symbiosis ; }, abstract = {The horizontal transfer of a bacterial endosymbiont that is intimately associated with reproductive isolation in insects is now feasible and may, in principle, lead to new strategies for biological pest control.}, }
@article {pmid8188611, year = {1994}, author = {Du, Y and McLaughlin, G and Chang, KP}, title = {16S ribosomal DNA sequence identities of beta-proteobacterial endosymbionts in three Crithidia species.}, journal = {Journal of bacteriology}, volume = {176}, number = {10}, pages = {3081-3084}, pmid = {8188611}, issn = {0021-9193}, mesh = {Animals ; Bacteria/classification/genetics/isolation &amp; purification ; Bordetella/genetics/*isolation &amp; purification ; Crithidia/*microbiology ; DNA, Bacterial/*isolation &amp; purification ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Sequence Homology, Nucleic Acid ; Symbiosis/*genetics ; }, abstract = {The 16S ribosomal DNA sequences of endosymbionts from the trypanosomatid protozoa (Crithidia spp.) are most homologous to that of Bordetella spp. This finding extends the polyphyletic origin of endosymbionts for the first time to the beta Proteobacteria. Biased base transitions and compensatory mutations of the symbionts' sequences that may contribute to their identity in the three Crithidia spp. are noted.}, }
@article {pmid8170994, year = {1994}, author = {Lai, CY and Baumann, L and Baumann, P}, title = {Amplification of trpEG: adaptation of Buchnera aphidicola to an endosymbiotic association with aphids.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {9}, pages = {3819-3823}, pmid = {8170994}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Anthranilate Synthase/genetics ; Aphids/*microbiology ; Bacteria/*genetics ; Base Sequence ; Biological Evolution ; DNA, Bacterial/genetics ; Gene Expression Regulation, Bacterial ; *Genes, Bacterial ; Molecular Sequence Data ; Operon ; Plasmids ; Repetitive Sequences, Nucleic Acid ; Restriction Mapping ; *Symbiosis ; Tryptophan/*metabolism ; }, abstract = {Survival of aphids is dependent on an association with a prokaryotic endosymbiont (Buchnera aphidicola) found in specialized cells within the aphid body cavity. Recent nutritional and physiological studies have indicated that one of the functions of the endosymbionts is the synthesis of tryptophan [Douglas, A. E. &amp; Prosser, W. A. (1992) J. Insect Physiol. 38, 565-568]. B. aphidicola resembles in many of its properties free-living prokaryotes. An adaptation to an endosymbiosis involving the overproduction of tryptophan would necessitate alterations that modify the effect of regulatory systems that in free-living organisms function to reduce enzyme activity under conditions of excess tryptophan. We have cloned and sequenced the genes for B. aphidicola trpEG encoding anthranilate synthase, the first enzyme of the tryptophan biosynthetic pathway, which in free-living bacteria is feedback-inhibited by tryptophan. Amino acid sequence comparisons indicate that the B. aphidicola enzyme has all of the key residues involved in allosteric feedback inhibition. Evidence is presented indicating that trpEG is present as four tandem repeats on a circular plasmid. Relative to B. aphidicola trpDC(F)BA (the chromosomal genes coding for the remaining enzymes of the tryptophan biosynthetic pathway) trpEG is amplified 14- to 15-fold. These findings suggest that the effect of inhibition by accumulated tryptophan may be overcome by overproduction of anthranilate synthase. Our results demonstrate the acquisition of a new property (gene amplification) as an adaptation to an endosymbiotic association in which B. aphidicola overproduces tryptophan for the aphid host.}, }
@article {pmid8170970, year = {1994}, author = {McFadden, GI and Gilson, PR and Hofmann, CJ and Adcock, GJ and Maier, UG}, title = {Evidence that an amoeba acquired a chloroplast by retaining part of an engulfed eukaryotic alga.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {9}, pages = {3690-3694}, pmid = {8170970}, issn = {0027-8424}, mesh = {Amoeba/*genetics/ultrastructure ; Animals ; Base Sequence ; *Biological Evolution ; *Chloroplasts ; Chromosome Mapping ; DNA Primers/chemistry ; DNA, Ribosomal/*genetics ; Endocytosis ; Eukaryota/*genetics ; Gene Expression ; Molecular Sequence Data ; RNA, Ribosomal/*genetics ; Symbiosis ; }, abstract = {Chlorarachniophytes are amoeboid algae with unusual chloroplasts. Instead of the usual two membranes that surround the chloroplasts of plants, green algae, and red algae, the chloroplasts of chlorarachniophytes have four bounding membranes. The extra membranes may reflect an unusual origin of chlorarachniophyte chloroplasts. Rather than inheriting the organelle directly from their ancestors, chlorarachniophytes may have adopted the chloroplast of an algal cell ingested as prey. Parts of the algal cell are postulated to remain within the amoeba as a reduced eukaryotic endosymbiont [Hibberd, D. J. &amp; Norris, R. E. (1984) J. Phycol. 20, 310-330]. A small nucleus-like structure, proposed to be a vestige of the endosymbiont's nucleus, is located in a space between the second and third chloroplast membranes. We cloned and sequenced nuclear-type rRNA genes from chlorarachniophytes and found two highly divergent genes. In situ hybridization shows that one gene is expressed by the amoebal (host) nucleus and the other is expressed by the putative endosymbiont nucleus, suggesting that the latter is indeed a foreign genome. Transcripts from the endosymbiont gene accumulate in the small cytoplasmic compartment between the second and third chloroplast membranes, which we believe to be the remnant cytoplasm of the endosymbiont. Using the endosymbiont gene as a probe, we identified three small chromosomes belonging to the endosymbiont nucleus. This knowledge should allow a detailed molecular analysis of the role of the endosymbiont's genome and cytoplasm in the partnership.}, }
@article {pmid8159671, year = {1994}, author = {Lake, JA and Rivera, MC}, title = {Was the nucleus the first endosymbiont?.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {91}, number = {8}, pages = {2880-2881}, pmid = {8159671}, issn = {0027-8424}, mesh = {Biological Evolution ; Cell Nucleus/*physiology ; *Eukaryotic Cells ; Origin of Life ; *Symbiosis ; }, }
@article {pmid8177222, year = {1994}, author = {Williamson, DH and Gardner, MJ and Preiser, P and Moore, DJ and Rangachari, K and Wilson, RJ}, title = {The evolutionary origin of the 35 kb circular DNA of Plasmodium falciparum: new evidence supports a possible rhodophyte ancestry.}, journal = {Molecular &amp; general genetics : MGG}, volume = {243}, number = {2}, pages = {249-252}, pmid = {8177222}, issn = {0026-8925}, support = {MC_U117532072/MRC_/Medical Research Council/United Kingdom ; }, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Consensus Sequence ; DNA, Circular/*genetics ; DNA, Protozoan/genetics ; Extrachromosomal Inheritance/genetics ; Genes, Plant/genetics ; Genes, Protozoan/*genetics ; Molecular Sequence Data ; Open Reading Frames ; *Phylogeny ; Plant Proteins/genetics ; Plasmodium falciparum/*genetics ; *Plastids ; Rhodophyta/*genetics ; Sequence Alignment ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; }, abstract = {In common with other Apicomplexan parasites, Plasmodium falciparum carries two extrachromosomal DNAs, one of which, the 6 kb element, is undoubtedly mitochondrial. The second, generally referred to as the 35 kb circle, is of unknown provenance, but the nature and organization of its genetic content makes a mitochondrial association unlikely and the molecule has features reminiscent of plastid genomes. We now report the occurrence on the circle of an open reading frame specifying a predicted 470 amino acid protein that shares more than 50% identity with a gene currently known only on the plastome of red algae. This high degree of conservation confirms the 35 kb circle's plastid ancestry, and we speculate that it may have originated from the rhodoplast of an ancient red algal endosymbiont in the progenitor of the Apicomplexa.}, }
@article {pmid8144471, year = {1994}, author = {Margolin, W and Long, SR}, title = {Rhizobium meliloti contains a novel second homolog of the cell division gene ftsZ.}, journal = {Journal of bacteriology}, volume = {176}, number = {7}, pages = {2033-2043}, pmid = {8144471}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Bacterial Proteins/biosynthesis/*genetics ; Base Sequence ; Cell Division/*genetics ; Chromosome Mapping ; *Cytoskeletal Proteins ; DNA Mutational Analysis ; Escherichia coli/genetics ; GTP-Binding Proteins/*genetics ; Genes, Bacterial/*genetics ; Genetic Linkage ; Genomic Library ; Molecular Sequence Data ; Multigene Family/*genetics ; Mutagenesis, Insertional ; Recombinant Proteins/biosynthesis ; Restriction Mapping ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Sinorhizobium meliloti/*genetics ; }, abstract = {We have identified a second homolog of the cell division gene, ftsZ, in the endosymbiont Rhizobium meliloti. The ftsZ2 gene was cloned by screening a genomic lambda library with a probe derived from PCR amplification of a highly conserved domain. It encodes a 36-kDa protein which shares a high level of sequence similarity with the FtsZ proteins of Escherichia coli and Bacillus subtilis and FtsZ1 (Z1) of R. meliloti but lacks the carboxy-terminal region conserved in other FtsZ proteins. The identity of the ftsZ2 gene product was confirmed both by in vitro transcription-translation in an R. meliloti S-30 extract and by overproduction in R. meliloti cells. As with Z1, the overproduction of FtsZ2 in E. coli inhibited cell division and induced filamentation, although to a lesser extent than with Z1. However, the expression of ftsZ2 in E. coli under certain conditions caused some cells to coil dramatically, a phenotype not observed during Z1 overproduction. Although several Tn3-GUS (glucuronidase) insertions in a plasmid-borne ftsZ2 gene failed to cross into the chromosome, one interruption in the chromosomal ftsZ2 gene was isolated, suggesting that ftsZ2 is nonessential for viability. The two ftsZ genes were genetically mapped to the R. meliloti main chromosome, approximately 100 kb apart.}, }
@article {pmid8144459, year = {1994}, author = {Distel, DL and Cavanaugh, CM}, title = {Independent phylogenetic origins of methanotrophic and chemoautotrophic bacterial endosymbioses in marine bivalves.}, journal = {Journal of bacteriology}, volume = {176}, number = {7}, pages = {1932-1938}, pmid = {8144459}, issn = {0021-9193}, mesh = {Animals ; Bacteria/*classification/genetics ; Base Sequence ; Biological Evolution ; Bivalvia/*microbiology/ultrastructure ; DNA, Ribosomal/genetics ; Gills/microbiology/ultrastructure ; In Situ Hybridization ; Methylococcaceae/*classification/genetics/isolation &amp; purification/ultrastructure ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {The discovery of bacterium-bivalve symbioses capable of utilizing methane as a carbon and energy source indicates that the endosymbionts of hydrothermal vent and cold seep bivalves are not restricted to sulfur-oxidizing chemoautotrophic bacteria but also include methanotrophic bacteria. The phylogenetic origin of methanotrophic endosymbionts and their relationship to known symbiotic and free-living bacteria, however, have remained unexplored. In situ localization and phylogenetic analysis of a symbiont 16S rRNA gene cloned from the gills of a recently described deep-sea mussel species demonstrate that this symbiont represents a new taxon which is closely related to free-living, cultivable Type I methanotrophic bacteria. This symbiont is distinct from known chemoautotrophic symbionts. Thus, despite compelling similarities between the symbioses, chemoautotrophic and methanotrophic symbionts of marine bivalves have independent phylogenetic origins.}, }
@article {pmid8056788, year = {1994}, author = {Michels, PA and Hannaert, V}, title = {The evolution of kinetoplastid glycosomes.}, journal = {Journal of bioenergetics and biomembranes}, volume = {26}, number = {2}, pages = {213-219}, pmid = {8056788}, issn = {0145-479X}, mesh = {Amino Acid Sequence ; Animals ; *Biological Evolution ; Carbohydrate Metabolism ; Cell Compartmentation ; Energy Metabolism ; Glycolysis ; Isoenzymes/metabolism ; Kinetoplastida/genetics/*metabolism/ultrastructure ; Microbodies/metabolism ; Molecular Sequence Data ; Oligopeptides/genetics/metabolism ; Organelles/*metabolism ; Protein Sorting Signals/genetics/metabolism ; }, abstract = {The available data on carbohydrate metabolism in Kinetoplastida have been reviewed. Based on the metabolic pattern of different kinetoplastid organisms, on the subcellular distribution of their glycolytic enzymes, and on the structural and regulatory properties of these proteins, we propose that the glycosome developed from an endosymbiont, as a specific manner to control carbohydrate and energy metabolism. It is discussed how the enzymes were subcellularly recompartmentalized during evolution as adaptation to the environment encountered by the organisms.}, }
@article {pmid8016269, year = {1994}, author = {Kaczor, CM and Smith, MW and Sangwan, I and O'Brian, MR}, title = {Plant delta-aminolevulinic acid dehydratase. Expression in soybean root nodules and evidence for a bacterial lineage of the Alad gene.}, journal = {Plant physiology}, volume = {104}, number = {4}, pages = {1411-1417}, pmid = {8016269}, issn = {0032-0889}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/enzymology/genetics ; Base Sequence ; DNA Probes ; Genes, Bacterial ; Genes, Plant ; Humans ; Mice ; Molecular Sequence Data ; *Phylogeny ; Plants/enzymology/genetics ; Porphobilinogen Synthase/biosynthesis/*genetics ; RNA, Messenger/biosynthesis/metabolism ; Soybeans/*enzymology/*genetics ; }, abstract = {We isolated a soybean (Glycine max) cDNA encoding the heme and chlorophyll synthesis enzyme delta-aminolevulinic acid (ALA) dehydratase by functional complementation of an Escherichia coli hemB mutant, and we designated the gene Alad. ALA dehydratase was strongly expressed in nodules but not in uninfected roots, although Alad mRNA was only 2- to 3-fold greater in the symbiotic tissue. Light was not essential for expression of Alad in leaves of dark-grown etiolated plantlets as discerned by mRNA, protein, and enzyme activity levels; hence, its expression in subterranean nodules was not unique in that regard. The data show that soybean can metabolize the ALA it synthesizes in nodules, which argues in favor of tetrapyrrole formation by the plant host in that organ. Molecular phylogenetic analysis of ALA dehydratases from 11 organisms indicated that plant and bacterial enzymes have a common lineage not shared by animals and yeast. We suggest that plant ALA dehydratase is descended from the bacterial endosymbiont ancestor of chloroplasts and that the Alad gene was transferred to the nucleus during plant evolution.}, }
@article {pmid8003693, year = {1994}, author = {Reynolds, AE and Chesnick, JM and Woolford, J and Cattolico, RA}, title = {Chloroplast encoded thioredoxin genes in the red algae Porphyra yezoensis and Griffithsia pacifica: evolutionary implications.}, journal = {Plant molecular biology}, volume = {25}, number = {1}, pages = {13-21}, pmid = {8003693}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Base Sequence ; Cell Nucleus/chemistry ; Chloroplasts/*chemistry ; Molecular Sequence Data ; Rhodophyta/*genetics/ultrastructure ; Sequence Homology, Amino Acid ; Thioredoxins/chemistry/*genetics ; }, abstract = {A gene encoding a thioredoxin protein was identified in the chloroplast genome of the rhodophyte Porphyra yezoensis. The P. yezoensis trxA gene contains 324 bp and is transcribed into a 0.7 kb messenger RNA. Analysis of the transcription start site demonstrates that canonical chloroplast -10 and -35 sequences are not present. The deduced amino acid sequence of the thioredoxin gene from the red algae has the greatest similarity to type m thioredoxins, providing strong support for the hypothesis that type m thioredoxins in photosynthetic eukaryotes originated from an engulfed bacterial endosymbiont. Hybridization analysis of nuclear and chloroplast DNAs from several members of the phyla Chromophyta and Rhodophyta using P. yezoensis DNA as a probe demonstrated strong hybridization to the chloroplast and nuclear genomes of Griffithsia pacifica and a weak cross-hybridization to the chromophyte P. foliaceum. The G. pacifica chloroplast gene has a 66% identity with the P. yezoensis DNA, contains conserved active site amino acid residues, but lacks a methionine start codon.}, }
@article {pmid8207087, year = {1994}, author = {McFadden, GI and Gilson, PR and Douglas, SE}, title = {The photosynthetic endosymbiont in cryptomonad cells produces both chloroplast and cytoplasmic-type ribosomes.}, journal = {Journal of cell science}, volume = {107 (Pt 2)}, number = {}, pages = {649-657}, doi = {10.1242/jcs.107.2.649}, pmid = {8207087}, issn = {0021-9533}, mesh = {Base Sequence ; Chloroplasts/metabolism/ultrastructure ; Chromosome Mapping ; Eukaryota/genetics/*metabolism/*ultrastructure ; Microscopy, Electron ; Molecular Sequence Data ; Photosynthesis ; RNA, Ribosomal/genetics ; Ribosomes/metabolism/ultrastructure ; Symbiosis ; }, abstract = {Cryptomonad algae contain a photosynthetic, eukaryotic endosymbiont. The endosymbiont is much reduced but retains a small nucleus. DNA from this endosymbiont nucleus encodes rRNAs, and it is presumed that these rRNAs are incorporated into ribosomes. Surrounding the endosymbiont nucleus is a small volume of cytoplasm proposed to be the vestigial cytoplasm of the endosymbiont. If this compartment is indeed the endosymbiont's cytoplasm, it would be expected to contain ribosomes with components encoded by the endosymbiont nucleus. In this paper, we used in situ hybridization to localize rRNAs encoded by the endosymbiont nucleus of the cryptomonad alga, Cryptomonas phi. Transcripts of the endosymbiont rRNA gene were observed within the endosymbiont nucleus, and in the compartment thought to represent the endosymbiont's cytoplasm. These results indicate that the endosymbiont produces its own set of cytoplasmic translation machinery. We also localized transcripts of the host nucleus rRNA gene. These transcripts were found in the nucleolus of the host nucleus, and throughout the host cytoplasm, but never in the endosymbiont compartment. Our rRNA localizations indicate that the cryptomonad cell produces two different of sets of cytoplasmic-type ribosomes in two separate subcellular compartments. The results suggest that there is no exchange of rRNAs between these compartments. We also used the probe specific for the endosymbiont rRNA gene to identify chromosomes from the endosymbiont nucleus in pulsed field gel electrophoresis. Like other cryptomonads, the endosymbiont nucleus of Cryptomonas phi contains three small chromosomes.}, }
@article {pmid8180687, year = {1994}, author = {Embley, TM and Finlay, BJ}, title = {The use of small subunit rRNA sequences to unravel the relationships between anaerobic ciliates and their methanogen endosymbionts.}, journal = {Microbiology (Reading, England)}, volume = {140 (Pt 2)}, number = {}, pages = {225-235}, doi = {10.1099/13500872-140-2-225}, pmid = {8180687}, issn = {1350-0872}, mesh = {Anaerobiosis ; Animals ; Bacterial Proteins/genetics/*physiology ; Ciliophora/genetics/*microbiology ; Euryarchaeota/*genetics/isolation &amp; purification ; Hemolysin Proteins ; Phenotype ; Phylogeny ; RNA, Ribosomal/*genetics ; RNA, Ribosomal, 16S/*genetics ; Sequence Homology, Nucleic Acid ; Species Specificity ; Symbiosis ; }, }
@article {pmid8021104, year = {1994}, author = {Stenzel, DJ and Boreham, PF}, title = {Bacteria-like endosymbionts in Blastocystis sp.}, journal = {International journal for parasitology}, volume = {24}, number = {1}, pages = {147-149}, doi = {10.1016/0020-7519(94)90070-1}, pmid = {8021104}, issn = {0020-7519}, mesh = {Animals ; Bacteria/ultrastructure ; *Bacterial Physiological Phenomena ; Blastocystis/*physiology/ultrastructure ; Ducks ; Feces/parasitology ; Macaca mulatta ; Microscopy, Electron ; *Symbiosis ; }, abstract = {Bacteria-like endosymbionts were found in vacuolar cells and cysts of Blastocystis sp. from duck and monkey faecal material. The organisms ultrastructurally resembled Gram-negative bacilli, and were present in the nucleus of Blastocystis sp. from the duck and in the cytoplasm of Blastocystis sp. from the monkey. Based on size and differences in intracellular location, it is probable that these represent two distinct species of organisms.}, }
@article {pmid8276120, year = {1994}, author = {Roise, D and Maduke, M}, title = {Import of a mitochondrial presequence into P. denitrificans. Insight into the evolution of protein transport.}, journal = {FEBS letters}, volume = {337}, number = {1}, pages = {9-13}, doi = {10.1016/0014-5793(94)80619-5}, pmid = {8276120}, issn = {0014-5793}, support = {T32-GM08326/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; *Biological Evolution ; Biological Transport ; Electron Transport Complex IV/chemistry/*metabolism ; Mitochondria/*enzymology ; Molecular Sequence Data ; Paracoccus denitrificans/*metabolism ; Peptide Fragments/chemistry/metabolism ; Protein Precursors/*metabolism ; Saccharomyces cerevisiae/enzymology/ultrastructure ; }, abstract = {According to the endosymbiont hypothesis, mitochondria are descended from ancient aerobic bacteria that were engulfed by protoeukaryotic cells. Experiments described here show that a synthetic peptide corresponding to a yeast mitochondrial targeting sequence can be imported into Paracoccus denitrificans, a soil bacterium thought to be closely related to the protomitochondrion. The import is very similar to that observed with isolated yeast mitochondria. The results suggest that the protomitochondrion may have been inherently able to translocate mitochondrial presequences. This ability may partly explain the development of the protein import process during the evolution of the mitochondrion.}, }
@article {pmid8790455, year = {1994}, author = {Ferretti, V and Lang, BF and Sankoff, D}, title = {Skewed base compositions, asymmetric transition matrices, and phylogenetic invariants.}, journal = {Journal of computational biology : a journal of computational molecular cell biology}, volume = {1}, number = {1}, pages = {77-92}, doi = {10.1089/cmb.1994.1.77}, pmid = {8790455}, issn = {1066-5277}, mesh = {Algorithms ; Aspergillus ; *Base Composition ; Computer Simulation ; Models, Biological ; *Phylogeny ; Rhizobium ; Rickettsia ; Saccharomyces cerevisiae ; Schizosaccharomyces ; }, abstract = {Evolutionary inference methods that assume equal DNA base compositions and symmetric nucleotide substitution matrices, where these assumptions do not hold, are likely to group species on the basis of similar base compositions rather than true phylogenetic relationships. We propose an invariants-based method for dealing with this problem. An invariant QT of a tree T under a k-state Markov model, where a generalized time parameter is identified with the E edges of T, allows us to recognize whether data on N observed species can be associated with the N terminal vertices of T in the sense of having been generated on T rather than on any other tree with N terminals. The form of the generalized time parameter is a positive determinant matrix in some semigroup S of stochastic matrices. The invariance is with respect to the choice of the set of E matrices in S, one associated with each of the E edges of T. We apply a general "empirical" method of finding invariants of a parametrized functional form. It involves calculating the probability f of all KN data possibilities for each of m sets of E matrices in S to associate with the edges of T, then solving for the parameters using the m equations of form Q(f) = 0. We discuss the problems of finding asymmetric models satisfying the property of semigroup closure, of finding asymmetric models that admit invariants at all, and of the computational complexity of the method. We propose a class of semigroups Sc containing matrices of form [formula: see text] to account for A+T versus G+C asymmetries in DNA base composition. Quadratic invariants are obtained for rooted trees with three and with four terminals. In the latter case the smallest set of algebraically independent invariants is sought. These invariants are applied to data pertaining the fungal evolution and to the origin of mitochondria as bacterial endosymbionts.}, }
@article {pmid8262651, year = {1994}, author = {Kim, KJ and Na, YE and Jeon, KW}, title = {Bacterial endosymbiont-derived lipopolysaccharides and a protein on symbiosome membranes in newly infected amoebae and their roles in lysosome-symbiosome fusion.}, journal = {Infection and immunity}, volume = {62}, number = {1}, pages = {65-71}, pmid = {8262651}, issn = {0019-9567}, mesh = {Amoeba/*microbiology ; Animals ; Antibodies, Monoclonal/immunology ; Fluorescent Antibody Technique ; Gram-Negative Bacteria/*growth &amp; development ; Intracellular Membranes/physiology ; Lipopolysaccharides/immunology/metabolism ; Lysosomes/physiology ; Membrane Fusion ; Symbiosis ; Vacuoles/physiology ; }, abstract = {Experimental results are presented to support the view that symbiont-derived lipopolysaccharides are involved in the prevention of lysosome-symbiosome fusion in xD amoebae harboring bacterial endosymbionts. Monoclonal antibodies against lipopolysaccharides and a 96-kDa protein present on symbiosome membranes of amoebae were used to monitor the appearance of the membrane-specific components in newly infected amoebae with endosymbionts from xD amoebae. The lipopolysaccharides and protein appeared on the newly forming symbiosome membranes within 3 to 7 days, as detected by indirect immunofluorescence staining with monoclonal antibodies. The lysosome-symbiosome fusion was followed by double staining of two antigens with different monoclonal antibodies applied to the same amoeba. Antilipopolysaccharide monoclonal antibodies were detected by staining with a fluorescein isothiocyanate-conjugated secondary antibody, and a biotinylated anti-lysosomal protein monoclonal antibody was detected by staining with Texas Red-conjugated streptavidin. In xD amoebae injected with an antilipopolysaccharide antibody, lysosomes fused with some of the symbiosomes that did not fuse with lysosomes in noninjected cells.}, }
@article {pmid8124266, year = {1994}, author = {Faria e Silva, PM and Fiorini, JE and Soares, MJ and Alviano, CS and de Souza, W and Angluster, J}, title = {Membrane-associated polysaccharides composition, nutritional requirements and cell differentiation in Herpetomonas roitmani: influence of the endosymbiont.}, journal = {The Journal of eukaryotic microbiology}, volume = {41}, number = {1}, pages = {55-59}, doi = {10.1111/j.1550-7408.1994.tb05934.x}, pmid = {8124266}, issn = {1066-5234}, mesh = {Animals ; Bacteria/metabolism ; Cell Membrane/chemistry ; Chloramphenicol/pharmacology ; Polysaccharides/*analysis ; *Symbiosis ; Trypanosomatina/*chemistry/cytology/drug effects/ultrastructure ; }, abstract = {Herpetomonas roitmani, a trypanosomatid containing a bacterial endosymbiont, was cured by high doses of chloramphenicol. Wild-type and cured flagellates were compared as to polysaccharide composition, nutritional requirements and cellular differentiation. Fucose (18.0%), xylose (15.7%), mannose (38.9%), galactose (10.8%), glucose (16.4%) and inositol (< 1.0%) were identified as polysaccharide components of cured H. roitmani as assessed by gas-liquid chromatography. However, the wild-type strain displayed a markedly different sugar profile, in that xylose was absent and inositol preferentially synthesized, whereas the other monosaccharide components remained unchanged. Variations in nutritional pattern also occurred between both strains. The bacterial endosymbiont seems to provide the flagellates with nutritional factors, including usual amino acids, vitamins, purine (as adenine) and hemin. The process of cell differentiation was also significantly influenced by the endosymbiont. Opisthomastigote forms predominate (72.0%) in cured as compared with wild-type H. roitmani (37.0%).}, }
@article {pmid7584036, year = {1994}, author = {Abe, R and Yamashita, A and Isono, K}, title = {Cloning and characterization of the ribosomal protein genes in the spc operon of a prokaryotic endosymbiont of the pea aphid, Acyrthosiphon kondoi.}, journal = {DNA research : an international journal for rapid publication of reports on genes and genomes}, volume = {1}, number = {3}, pages = {103-114}, doi = {10.1093/dnares/1.3.103}, pmid = {7584036}, issn = {1340-2838}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Bacteria/*genetics ; Bacterial Proteins/*genetics ; Base Composition ; Base Sequence ; Cloning, Molecular ; Escherichia coli/genetics ; *Escherichia coli Proteins ; Genes, Bacterial/*genetics ; Molecular Sequence Data ; Operon/genetics ; Peas/parasitology ; Ribosomal Proteins/*genetics ; SEC Translocation Channels ; Sequence Analysis, DNA ; Sequence Homology, Amino Acid ; Symbiosis ; }, abstract = {To correlate a prokaryotic endosymbiont in the pea aphid, Acyrthosiphon kondoi, with the endosymbionts in related aphid species as well as with free-living bacteria and subcellular organelles, and to study the mode of its gene expression within aphid cells, we have cloned and characterized the genes encoding ribosomal proteins S3, L16, L29, S17, L14, L24, L5, S14, S8, L6, L18, S5, L30, L15 and secretion protein Y (Sec Y) from the S10 and spc ribosomal protein gene operons of this endosymbiont. The organization of these genes is identical to that in Escherichia coli, and their nucleotide sequences are highly similar (87% identity) to the corresponding E. coli genes. They are much less similar to the corresponding chloroplast and mitochondrial genes. The guanine plus cytosine G+C content of the genes of the A. kondoi endosymbiont is much higher than those of the endosymbionts in related aphid species reported so far. It appears either that the A. kondoi endosymbiont is derived from an ancestral bacterium different from those in other aphids or that its G+C content increased in a relatively short time after the evolutionary divergence of its host.}, }
@article {pmid7507875, year = {1993}, author = {Munson, MA and Baumann, L and Baumann, P}, title = {Buchnera aphidicola (a prokaryotic endosymbiont of aphids) contains a putative 16S rRNA operon unlinked to the 23S rRNA-encoding gene: sequence determination, and promoter and terminator analysis.}, journal = {Gene}, volume = {137}, number = {2}, pages = {171-178}, doi = {10.1016/0378-1119(93)90003-l}, pmid = {7507875}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Bacteria/*genetics ; Base Sequence ; DNA, Bacterial ; Genetic Linkage ; Molecular Sequence Data ; Nucleic Acid Conformation ; Open Reading Frames ; *Operon ; *Promoter Regions, Genetic ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/*genetics ; RNA, Ribosomal, 23S/*genetics ; *Terminator Regions, Genetic ; }, abstract = {The aphid Schizaphis graminum is dependent on an association with Buchnera aphidicola, an eubacterial endosymbiont located in specialized host cells. Past studies have indicated that Escherichia coli is the closest known relative of the endosymbiont which has many genetic attributes of free-living bacteria. In order to obtain information on the properties of highly expressed genes, we have chosen for study the single-copy rrs (gene encoding 16S rRNA) of B. aphidicola. A 4.4-kb DNA fragment was cloned into E. coli and the nucleotide (nt) sequence determined. Several ORFs were identified; the order of genes was argS-rrs-ORF1-rnh-dnaQ. ArgS, RNase H and DnaQ had 36-57% amino acid (aa) identity to the homologous proteins of E. coli. B. aphidicola rrs appears to be part of an operon consisting of a putative promoter, rrs and two inverted repeats resembling Rho-independent terminators. Comparisons of the sequences of argS-rrn DNA fragments from endosymbionts of six additional aphid species indicated conservation of sequences corresponding to a single -35 (TTGACA) and -10 (TGTAAT) promoter region, as well as boxA (sequence involved in antitermination) and boxC. The B. aphidicola argS-rrn DNA fragments from endosymbionts from seven species of aphids had promoter activities in E. coli which ranged from 6 to 135% of that observed with a comparable DNA fragment of E. coli rrnB. Similarly, the putative B. aphidicola terminator was functional in E. coli. In most eubacteria, the rRNA-encoding genes are arranged in the order, 16S, 23S, 5S, and are part of a single operon.(ABSTRACT TRUNCATED AT 250 WORDS)}, }
@article {pmid8118213, year = {1993}, author = {Gray, MW}, title = {Origin and evolution of organelle genomes.}, journal = {Current opinion in genetics &amp; development}, volume = {3}, number = {6}, pages = {884-890}, doi = {10.1016/0959-437x(93)90009-e}, pmid = {8118213}, issn = {0959-437X}, mesh = {*Biological Evolution ; Eukaryotic Cells ; *Genome ; Mitochondria ; *Organelles ; Plastids ; RNA Editing ; Symbiosis ; }, abstract = {Molecular data (particularly sequence analyses) have established that two eukaryotic organelles, the mitochondrion and the plastid, are the descendants of endosymbiotic (eu)bacteria whose closest living relatives are the alpha-Proteobacteria (mitochondrion) and Cyanobacteria (plastid). This review describes recent data that favor the view that each organelle arose via this primary endosymbiotic pathway only once (monophyletic origin), such as the discovery of group I introns that appear to be structurally homologous and have identical insertion sites in metaphyte, chlorophyte and fungal mitochondrial genomes. However, it is also evident that the plastids in certain algal groups were acquired secondarily through a eukaryotic rather than a prokaryotic endosymbiont.}, }
@article {pmid8234331, year = {1993}, author = {Springer, N and Ludwig, W and Amann, R and Schmidt, HJ and Görtz, HD and Schleifer, KH}, title = {Occurrence of fragmented 16S rRNA in an obligate bacterial endosymbiont of Paramecium caudatum.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {90}, number = {21}, pages = {9892-9895}, pmid = {8234331}, issn = {0027-8424}, mesh = {Animals ; Base Sequence ; Blotting, Northern ; Blotting, Southern ; DNA Primers ; In Situ Hybridization ; Models, Structural ; Molecular Sequence Data ; Nucleic Acid Conformation ; Paramecium/classification/*genetics ; Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/analysis/chemistry/*genetics ; }, abstract = {The phylogenetic position of Caedibacter caryophila, a so far noncultured killer symbiont of Paramecium caudatum, was elucidated by comparative sequence analysis of in vitro amplified 16S rRNA genes (rDNA). C. caryophila is a member of the alpha subclass of the Proteobacteria phylum. Within this subclass C. caryophila is moderately related to Holospora obtusa, which is another obligate endosymbiont of Paramecium caudatum, and to Rickettsia. A 16S rRNA targeted specific hybridization probe was designed and used for in situ detection of C. caryophila within its host cell. Comparison of the 16S rDNA primary structure of C. caryophila with homologous sequences from other bacteria revealed an unusual insertion of 194 base pairs within the 5'-terminal part of the corresponding gene. The intervening sequence is not present in mature 16S rRNA of C. caryophila. It was demonstrated that C. caryophila contained fragmented 16S rRNA.}, }
@article {pmid8226669, year = {1993}, author = {Chauhan, S and O'Brian, MR}, title = {Bradyrhizobium japonicum delta-aminolevulinic acid dehydratase is essential for symbiosis with soybean and contains a novel metal-binding domain.}, journal = {Journal of bacteriology}, volume = {175}, number = {22}, pages = {7222-7227}, pmid = {8226669}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Base Sequence ; Binding Sites ; Cloning, Molecular ; DNA, Bacterial/isolation &amp; purification/metabolism ; Edetic Acid/pharmacology ; Escherichia coli ; Gene Expression ; *Genes, Bacterial ; Genetic Complementation Test ; Genomic Library ; Humans ; Kinetics ; Magnesium/metabolism/pharmacology ; Molecular Sequence Data ; Plasmids ; Porphobilinogen Synthase/*genetics/*metabolism ; Recombinant Proteins/pharmacology ; Rhizobiaceae/*enzymology/genetics/*physiology ; Sequence Homology, Amino Acid ; Soybeans/*physiology ; *Symbiosis ; Zinc/*metabolism/pharmacology ; }, abstract = {The Bradyrhizobium japonicum hemA gene product delta-aminolevulinic acid (ALA) synthase is not required for symbiosis of that bacterium with soybean. Hence, the essentiality of the subsequent heme synthesis enzyme, ALA dehydratase, was examined. The B. japonicum ALA dehydratase gene, termed hemB, was isolated and identified on the basis of its ability to confer hemin prototrophy and enzyme activity on an Escherichia coli hemB mutant, and it encoded a protein that was highly homologous to ALA dehydratases from diverse organisms. A novel metal-binding domain in the B. japonicum ALA dehydratase was identified that is a structural composite of the Mg(2+)-binding domain found in plant ALA dehydratases and the Zn(2+)-binding region of nonplant ALA dehydratases. Enzyme activity in dialyzed extracts of cells that overexpressed the hemB gene was reconstituted by the addition of Mg2+ but not by addition of Zn2+, indicating that the B. japonicum ALA dehydratase is similar to the plant enzymes with respect to its metal requirement. Unlike the B. japonicum hemA mutant, the hemB mutant strain KP32 elicited undeveloped nodules on soybean, indicated by the lack of nitrogen fixation activity and plant hemoglobin. We conclude that the hemB gene is required for nodule development and propose that B. japonicum ALA dehydratase is the first essential bacterial enzyme for B. japonicum heme synthesis in soybean root nodules. In addition, we postulate that ALA is the only heme intermediate that can be translocated from the plant to the endosymbiont to support bacterial heme synthesis in nodules.}, }
@article {pmid8407819, year = {1993}, author = {Munson, MA and Baumann, P}, title = {Molecular cloning and nucleotide sequence of a putative trpDC(F)BA operon in Buchnera aphidicola (endosymbiont of the aphid Schizaphis graminum).}, journal = {Journal of bacteriology}, volume = {175}, number = {20}, pages = {6426-6432}, pmid = {8407819}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Bacteria/*genetics ; Base Sequence ; Cloning, Molecular ; DNA Primers/chemistry ; Escherichia coli/genetics ; *Genes, Bacterial ; Molecular Sequence Data ; Open Reading Frames ; *Operon ; Regulatory Sequences, Nucleic Acid ; Sequence Alignment ; Symbiosis ; *Tryptophan ; }, abstract = {A 8,392-nucleotide-long DNA fragment from Buchnera aphidicola (endosymbiont of the aphid Schizaphis graminum) contained five genes of the tryptophan biosynthetic pathway [trpDC(F)BA] which code for enzymes converting anthranilate to tryptophan. These genes are probably arranged as a single transcription unit. Downstream of the trp genes were ORF-V, ORF-VI, and P14, three open reading frames which in Escherichia coli are also found downstream of the trp operon. Upstream of the B. aphidicola trp genes were two unidentified open reading frames, one of which potentially codes for a membrane-spanning protein with a leader sequence. Evidence for the presence of trpB in the endosymbionts of eight additional species of aphids and two species of whiteflies was obtained. These results as well as those of A. E. Douglas and W. A. Prosser (J. Insect Physiol. 38:565-568, 1992) suggest that aphid endosymbionts are capable of synthesizing tryptophan, which is required by the aphid host.}, }
@article {pmid8219057, year = {1993}, author = {Kostrzewa, M and Zetsche, K}, title = {Organization of plastid-encoded ATPase genes and flanking regions including homologues of infB and tsf in the thermophilic red alga Galdieria sulphuraria.}, journal = {Plant molecular biology}, volume = {23}, number = {1}, pages = {67-76}, pmid = {8219057}, issn = {0167-4412}, mesh = {Adenosine Triphosphatases/*genetics ; Amino Acid Sequence ; Biological Evolution ; Blotting, Northern ; Molecular Sequence Data ; Phylogeny ; Plastids/*enzymology ; Restriction Mapping ; Rhodophyta/enzymology/*genetics ; Sequence Homology, Amino Acid ; Transcription, Genetic ; }, abstract = {We have cloned and sequenced the plastid ATPase operons (atp1 and atp2) and flanking regions from the unicellular red alga Galdieria sulphuraria (Cyanidium caldarium). Six genes (5 atpI, H, G, F, D and A 3) are linked in atp1 encoding ATPase subunits a, c, b, b, delta and alpha, respectively. The atpF gene does not contain an intron and overlaps atpD by 1 bp. As in the genome of chloroplasts from land plants, the cluster is located downstream of rps2, but between this gene and atp1 we found the gene for the prokaryotic translation elongation factor TS. Downstream of atpA, we detected two open reading frames, one encoding a putative transport protein. The genes atpB and atpE, encoding ATPase subunits beta and epsilon, respectively, are linked in atp2, separated by a 2 bp spacer. Upstream of atpB, an uninterrupted orf167 was detected which is homologous to an intron-containing open reading frame in land plant chloroplasts. This orf167 is preceded on the opposite DNA strand by a homologue to initiation factor 2 in prokaryotes. The arrangement of atp1 and atp2 is the same as observed in the multicellular red alga Antithamnion sp., indicating a conserved genome arrangement in the red algal plastid genome. Differences compared to green chloroplast genomes suggest a large phylogenetic distance between red algae and green plants, while similarities in arrangement and sequence to chromophytic ATPase operons support a red algal origin of chlorophyll a/c-containing plastids or alternatively point to a common prokaryotic endosymbiont.}, }
@article {pmid8180629, year = {1993}, author = {Stein, JL and Felbeck, H}, title = {Kinetic and physical properties of a recombinant RuBisCO from a chemoautotrophic endosymbiont.}, journal = {Molecular marine biology and biotechnology}, volume = {2}, number = {5}, pages = {280-290}, pmid = {8180629}, issn = {1053-6426}, mesh = {Animals ; Bacteria/*enzymology ; Enzyme Stability ; Recombinant Proteins/metabolism ; Ribulose-Bisphosphate Carboxylase/genetics/*metabolism ; Snails/*microbiology ; *Symbiosis ; }, abstract = {Ribulose 1,5 bisphosphate carboxylase/oxygenase (RuBisCO), which catalyzes the key step in autotrophic CO2 fixation, is present at high activity in the symbiont-containing tissues of many hydrothermal vent invertebrates. The genes encoding RuBisCO from a gill endosymbiont of the hydrothermal vent gastropod Alviniconcha hessleri have been cloned, sequenced, and functionally expressed in Escherichia coli under control of the lac promoter in the vector pBlueScript. The purified protein is a hexadecamer (L8S8) with an apparent molecular weight of 554 kDa and a specific carboxylase activity of 2.9 mumol/min/mg protein. Unlike previously characterized RuBisCOs, which display sharp temperature optima, the symbiont RuBisCO maintains a high level of activity over a broad temperature span, although it is not thermally stable after extended exposure to temperatures above 50 degrees C. This funding suggests an adaptation to the thermal transients measured at vent openings where the host snail resides. The enzyme also maintains 90% of its 1 atm activity at 370 atm pressure, whereas spinach RuBisCO retains 28% activity under similar conditions. At 1 atm pressure and 20 degrees C, the Km(CO2) and the relative substrate specificity (Srel) of the symbiont enzyme were 80 and 32.5 mumol/L, respectively, which are similar to values reported for RuBisCOs from cyanobacteria and the purple photosynthetic bacteria. The relatively low specificity of the enzyme for substrate CO2 indicates that the intracellular environment of the endosymbionts may be microaerophilic for RuBisCO to maintain net carboxylation.}, }
@article {pmid7903968, year = {1993}, author = {Morioka, M and Ishikawa, H}, title = {Self-assembly of symbionin, a chaperonin of intracellular symbiont.}, journal = {Journal of biochemistry}, volume = {114}, number = {4}, pages = {468-472}, doi = {10.1093/oxfordjournals.jbchem.a124201}, pmid = {7903968}, issn = {0021-924X}, mesh = {Adenosine Triphosphatases/metabolism ; Adenosine Triphosphate/pharmacology ; Animals ; Aphids ; Bacterial Proteins/*chemistry ; Chaperonin 10 ; Chaperonin 60 ; *Chaperonins ; Chromatography, High Pressure Liquid ; Escherichia coli/chemistry ; Heat-Shock Proteins/chemistry/pharmacology ; Kinetics ; Macromolecular Substances ; Molecular Weight ; Phosphotransferases/metabolism ; Urea/pharmacology ; }, abstract = {Symbionin, a homologue of Escherichia coli GroEL, which functions as a molecular chaperone in the aphid endosymbiont, exists as a double-doughnut structure, consisting of two rings of seven 63-kDa subunits. Symbionin had a more labile oligomeric structure than GroEL and completely disassembled into monomeric (1-mer) components in 3 M urea. The urea-dissociated symbionin self-assembled into 14-mer symbionin in a Mg-ATP dependent manner. When 1-mer symbionin was incubated in the presence of Mg-ATP, its reassembly proceeded hyperbolically with time. The yield of reassembled symbionin increased in response to increase in the initial concentration of 1-mer symbionin. The reassembled symbionin not only had the same molecular mass as native symbionin but also exhibited the same ATPase and phosphotransferase activity, suggesting that the correct three-dimensional structure was restored in vitro. While the self-assembly of symbionin was markedly stimulated by the presence of reassembled symbionin, it was not affected by the presence of native symbionin, which may suggest that native symbionin contains component(s) inhibitory to its chaperoning activity. As in the self-assembly of GroEL, that of symbionin was stimulated by the presence of GroES.}, }
@article {pmid8378350, year = {1993}, author = {Martin, W and Brinkmann, H and Savonna, C and Cerff, R}, title = {Evidence for a chimeric nature of nuclear genomes: eubacterial origin of eukaryotic glyceraldehyde-3-phosphate dehydrogenase genes.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {90}, number = {18}, pages = {8692-8696}, pmid = {8378350}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Anabaena/*enzymology/*genetics ; Animals ; *Biological Evolution ; Blotting, Southern ; Escherichia coli/enzymology/*genetics ; Genes, Bacterial ; Genes, Plant ; Genetic Variation ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Glycolysis ; Humans ; Molecular Sequence Data ; *Multigene Family ; *Phylogeny ; Sequence Homology, Amino Acid ; }, abstract = {Higher plants process two distinct, nuclear gene-encoded glyceraldehyde-3-phosphate dehydrogenase (GAPDH) proteins, a Calvin-cycle enzyme active within chloroplasts and a glycolytic enzyme active within the cytosol. The gene for the chloroplast enzyme was previously suggested to be of endosymbiotic origin. Since the ancestors of plastids were related to cyanobacteria, we have studied GAPDH genes in the cyanobacterium Anabaena variabilis. Our results confirm that the nuclear gene for higher plant chloroplast GAPDH indeed derives from the genome of a cyanobacterium-like endosymbiont. But two additional GAPDH genes were found in the Anabaena genome and, surprisingly, one of these sequences is very similar to nuclear genes encoding the GAPDH enzyme of glycolysis in plants, animals, and fungi. Evidence that the eukaryotic nuclear genes for glycolytic GAPDH, as well as the Calvin-cycle genes, are of eubacterial origin suggests that eukaryotic genomes are more highly chimeric than previously assumed.}, }
@article {pmid7685713, year = {1993}, author = {Brennicke, A and Grohmann, L and Hiesel, R and Knoop, V and Schuster, W}, title = {The mitochondrial genome on its way to the nucleus: different stages of gene transfer in higher plants.}, journal = {FEBS letters}, volume = {325}, number = {1-2}, pages = {140-145}, doi = {10.1016/0014-5793(93)81430-8}, pmid = {7685713}, issn = {0014-5793}, mesh = {Cell Nucleus/*metabolism ; DNA/metabolism ; *Genes, Plant ; Mitochondria/*metabolism ; Plants/*genetics/ultrastructure ; RNA/metabolism ; }, abstract = {The vast majority of mitochondrial proteins are in all eukaryotes encoded in the nuclear genomes by genes which have been transferred from the original endosymbiont. DNA as well as RNA was and is exchanged between organelles. A functionally successful information transfer, however, requires complex structural and regulatory alterations of the concerned gene. The recently identified variations of the information content in mitochondrial genomes of different plant species represent different stages of the transfer process. These evolutionary intermediates allow a definition of requirements and chances of successful gene transfers.}, }
@article {pmid8511587, year = {1993}, author = {Boyle, L and O'Neill, SL and Robertson, HM and Karr, TL}, title = {Interspecific and intraspecific horizontal transfer of Wolbachia in Drosophila.}, journal = {Science (New York, N.Y.)}, volume = {260}, number = {5115}, pages = {1796-1799}, doi = {10.1126/science.8511587}, pmid = {8511587}, issn = {0036-8075}, mesh = {Animals ; Cytoplasm/microbiology/physiology ; Drosophila/*microbiology/physiology ; Drosophila melanogaster/*microbiology/physiology ; Female ; Male ; Microinjections ; Microscopy ; Ovum/microbiology/physiology ; Rickettsiaceae/*physiology ; }, abstract = {Cytoplasmic incompatibility (CI) in Drosophila simulans is related to infection of the germ line by a rickettsial endosymbiont (genus Wolbachia). Wolbachia were transferred by microinjection of egg cytoplasm into uninfected eggs of both D. simulans and D. melanogaster to generate infected populations. Transinfected strains of D. melanogaster with lower densities of Wolbachia than the naturally infected D. simulans strain did not express high levels of CI. However, transinfected D. melanogaster egg cytoplasm, transferred back into D. simulans, generated infected populations that expressed CI at levels near those of the naturally infected strain. A transinfected D. melanogaster line selected for increased levels of CI expression also displayed increased symbiont densities. These data suggest that a threshold level of infection is required for normal expression of CI and that host factors help determine the density of the symbiont in the host.}, }
@article {pmid8100068, year = {1993}, author = {Cary, SC and Giovannoni, SJ}, title = {Transovarial inheritance of endosymbiotic bacteria in clams inhabiting deep-sea hydrothermal vents and cold seeps.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {90}, number = {12}, pages = {5695-5699}, pmid = {8100068}, issn = {0027-8424}, mesh = {Animals ; Bacteria/genetics/isolation &amp; purification ; *Bacterial Physiological Phenomena ; Base Sequence ; Bivalvia/*microbiology ; DNA, Bacterial/genetics/isolation &amp; purification ; Female ; Genes, Bacterial ; In Situ Hybridization ; Oligonucleotide Probes ; Ovary/microbiology ; Polymorphism, Restriction Fragment Length ; RNA, Ribosomal, 16S/analysis/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {Vesicomyid clams are conspicuous fauna at many deep-sea hydrothermal-vent and cold-seep habitats. All species examined have specialized gill tissue harboring endosymbiotic bacteria, which are thought to provide the hosts' sole nutritional support. In these species mechanisms of symbiont inheritance are likely to be key elements of dispersal strategies. These mechanisms have remained unresolved because the early life stages are not available for developmental studies. A specific 16S rRNA-directed oligodeoxynucleotide probe (CG1255R) for the vesocomyid endosymbionts was used in a combination of sensitive hybridization techniques to detect and localize the endosymbionts in host germ tissues. Symbiont-specific polymerase chain reaction amplifications, comparative gene sequencing, and restriction fragment length polymorphisms were used to detect and confirm the presence of symbiont target in tissue nucleic acid extracts. Nonradioactive in situ hybridizations were used to resolve the position of the bacterial endosymbionts in host cells. Symbiont 16S rRNA genes were consistently amplified from the ovarial tissue of three species of vesicomyid clams: Calyptogena magnifica, C. phaseoliformis, and C. pacifica. The nucleotide sequences of the genes amplified from ovaries were identical to those from the respective host symbionts. In situ hybridizations to CG1255R labeled with digoxigenin-11-dUTP were performed on ovarial tissue from each of the vesicomyid clams. Detection of hybrids localized the symbionts to follicle cells surrounding the primary oocytes. These results suggest that vesicomyid clams assure successful, host-specific inoculation of all progeny by using a transovarial mechanism of symbiont transmission.}, }
@article {pmid8102406, year = {1993}, author = {Fukatsu, T and Ishikawa, H}, title = {Occurrence of chaperonin 60 and chaperonin 10 in primary and secondary bacterial symbionts of aphids: implications for the evolution of an endosymbiotic system in aphids.}, journal = {Journal of molecular evolution}, volume = {36}, number = {6}, pages = {568-577}, pmid = {8102406}, issn = {0022-2844}, mesh = {Animals ; Aphids/classification/embryology/genetics/*microbiology ; Bacterial Proteins/*genetics ; Blotting, Western ; Chaperonin 10 ; Chaperonin 60 ; Chaperonins ; Escherichia coli/genetics ; *Genes, Insect ; Heat-Shock Proteins/genetics ; Immunoenzyme Techniques ; Male ; Models, Biological ; Organelles ; Phylogeny ; Prokaryotic Cells/*chemistry ; Proteins/*genetics ; Rabbits ; Species Specificity ; *Symbiosis ; }, abstract = {All aphids harbor symbiotrophic prokaryotes ("primary symbionts") in a specialized-abdominal cell, the bacteriocyte. Chaperonin 60 (Cpn60, symbionin) and chaperonin 10 (Cpn10), which are high and low molecular weight heatshock proteins, were sought in tissues of more than 60 aphid species. The endosymbionts were compared immunologically and histologically. It was demonstrated that (1) there are two types of aphids in terms of the endosymbiotic system: some with only primary symbionts and others with, in addition, secondary symbionts; (2) the primary symbionts of various aphids are quite similar in morphology whereas the secondary symbionts vary; and (3) irrespective of the aphid species, Cpn60 is abundant in both the primary and secondary symbionts, while Cpn10 is abundant in the secondary symbionts but present in small amounts in the primary ones. Based on these results, we suggest that the primary symbionts have been derived from a prokaryote that was acquired by the common ancestor of aphids whereas the secondary symbionts have been acquired by various aphids independently after divergence of the aphid species. In addition, we point out the possibility that the prokaryotes under intracellular conditions have been subject to some common evolutionary pressures, and as a result, have come to resemble cell organelles.}, }
@article {pmid8501212, year = {1993}, author = {Fritsche, TR and Gautom, RK and Seyedirashti, S and Bergeron, DL and Lindquist, TD}, title = {Occurrence of bacterial endosymbionts in Acanthamoeba spp. isolated from corneal and environmental specimens and contact lenses.}, journal = {Journal of clinical microbiology}, volume = {31}, number = {5}, pages = {1122-1126}, pmid = {8501212}, issn = {0095-1137}, support = {EY08179/EY/NEI NIH HHS/United States ; }, mesh = {Acanthamoeba/isolation &amp; purification/*microbiology ; Acanthamoeba Keratitis/microbiology/parasitology ; Animals ; Contact Lenses/adverse effects ; Cornea/microbiology/parasitology ; Environment ; Gram-Negative Bacteria/classification/*isolation &amp; purification/ultrastructure ; Humans ; Microscopy, Electron ; Symbiosis ; }, abstract = {Free-living and parasitic protozoa are known to harbor a variety of endosymbiotic bacteria, although the roles such endosymbionts play in host survival, infectivity, and invasiveness are unclear. We have identified the presence of intracellular bacteria in 14 of 57 (24%) axenically grown Acanthamoeba isolates examined. These organisms are gram negative and non-acid fast, and they cannot be cultured by routine methodologies, although electron microscopy reveals evidence for multiplication within the amoebic cytoplasm. Examination for Legionella spp. with culture and nucleic acid probes has proven unsuccessful. We conclude that these bacteria are endosymbionts which have an obligate need to multiply within their amoebic hosts. Rod-shaped bacteria were identified in 5 of 23 clinical Acanthamoeba isolates (3 of 19 corneal isolates and 2 of 4 contact lens isolates), 4 of 25 environmental Acanthamoeba isolates, and 2 of 9 American Type Culture Collection Acanthamoeba isolates (ATCC 30868 and ATCC 30871) previously unrecognized as having endosymbionts. Coccus-shaped bacteria were present in one clinical (corneal) isolate and two environmental isolates. There was no statistical difference (P > 0.8) between the numbers of endosymbiont strains originating from clinical (26% positive) and environmental (24% positive) amoebic isolates, suggesting that the presence alone of these bacteria does not enhance amoebic infectivity. Rods and cocci were found in both clinical and environmental isolates from different geographical areas (Seattle, Wash., and Portland, Oreg.), demonstrating their widespread occurrence in nature. Our findings suggest that endosymbiosis occurs commonly among members of the family Acanthamoebidae and that the endosymbionts comprise a diverse taxonomic assemblage. The role such endosymbionts may play in pathogenesis remains unknown, although a variety of exogenous bacteria have been implicated in the development of amoebic keratitis, warranting further evaluation.}, }
@article {pmid7689622, year = {1993}, author = {Bressac, C and Rousset, F}, title = {The reproductive incompatibility system in Drosophila simulans: DAPI-staining analysis of the Wolbachia symbionts in sperm cysts.}, journal = {Journal of invertebrate pathology}, volume = {61}, number = {3}, pages = {226-230}, doi = {10.1006/jipa.1993.1044}, pmid = {7689622}, issn = {0022-2011}, mesh = {Aging ; Animals ; Drosophila/*microbiology ; Fluorescent Dyes ; Indoles ; Male ; Rickettsiaceae/*isolation &amp; purification ; Spermatozoa/microbiology ; Staining and Labeling/*methods ; }, abstract = {Any hitherto available technique used to detect the presence of Wolbachia, a rickettsia-like endosymbiont of Drosophila simulans, i.e., crossing with tester strains, electron microscope observations, DAPI-staining of embryo, or amplification of specific sequences by PCR are notably time-consuming techniques. Staining sperm cysts with the fluorochrome DAPI is here shown to be a fast and reliable technique to detect the symbiont and evaluate the level of infection of individual males. Wolbachia cells are abundant in sperm cysts and make up a mass which is eliminated in the waste bag during spermatogenesis. Such a mass was absent in all those strains known to be aposymbiotic. In infected strains, tetracycline treatment led to the disappearance of the symbionts within sperm cysts. In aging males, a decrease in the proportion of infected cysts were observed. There was however no apparent change in the number of symbionts in the cysts which remained infected. The reduction of reproductive incompatibility, which is observed in older males, may be explained by this process, i.e., a decrease in the frequency of infected cysts.}, }
@article {pmid8463282, year = {1993}, author = {Flachmann, R and Michalowski, CB and Löffelhardt, W and Bohnert, HJ}, title = {SecY, an integral subunit of the bacterial preprotein translocase, is encoded by a plastid genome.}, journal = {The Journal of biological chemistry}, volume = {268}, number = {10}, pages = {7514-7519}, pmid = {8463282}, issn = {0021-9258}, mesh = {Adenosine Triphosphatases/*genetics/metabolism ; Amino Acid Sequence ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; Cyanobacteria/genetics ; DNA ; Escherichia coli ; *Escherichia coli Proteins ; Eukaryota/*genetics/metabolism ; Genetic Complementation Test ; *Membrane Transport Proteins ; Molecular Sequence Data ; Organelles/*metabolism ; Recombinant Fusion Proteins/genetics/metabolism ; SEC Translocation Channels ; SecA Proteins ; Sequence Homology, Amino Acid ; }, abstract = {Although the paradigm for the acquisition of photosynthetic organelles is the endocytosis of cyanobacteria-like progenitors by heterotrophic protists, details of this evolutionary process are unclear. The small organellar chromosomes are remnants of the larger bacterial genomes with most genes from the endosymbiont's DNA having been either relocated to the protist's nucleus or entirely lost. As a result of those gene transfers, differences exist between plastids from different algal phyla and higher plants. We report here on the retention of a secY gene in cyanelle (= plastid) DNA of the eukaryotic protist Cyanophora paradoxa. This cyanelle secY encodes a functional protein homologous to SecY of Escherichia coli, identified as a subunit of the preprotein translocase complex. Similarity of the cyanelle and E. coli SecY topology, predicted from sequence information, has been confirmed experimentally through SecY-PhoA fusion protein analysis in E. coli. Cyanelle SecY, expressed in an E. coli secY mutant, substituted for the defective prokaryotic SecY. A plastid-encoded gene for a membrane protein functioning in protein transport across plastid membranes is unprecedented in higher plants. From these results we infer that a functional homolog of the prokaryotic preprotein translocation machinery is retained in some plastids.}, }
@article {pmid8318698, year = {1993}, author = {Brewin, NJ}, title = {The Rhizobium-legume symbiosis: plant morphogenesis in a nodule.}, journal = {Seminars in cell biology}, volume = {4}, number = {2}, pages = {149-156}, doi = {10.1006/scel.1993.1018}, pmid = {8318698}, issn = {1043-4682}, mesh = {Extracellular Matrix/microbiology ; Fabaceae/*microbiology/ultrastructure ; Flavonoids/chemistry/physiology ; Genes, Bacterial ; Lipopolysaccharides/metabolism ; Morphogenesis ; Nitrogen Fixation/genetics ; *Plants, Medicinal ; Rhizobium/*physiology ; Signal Transduction ; *Symbiosis ; }, abstract = {Development of the legume root nodule can be divided conceptually into two parallel processes. On the one hand, there is the induction of a nodule meristem and the progressive differentiation of specialised cells and tissues. On the other hand, there is cell and tissue invasion by Rhizobium, which leads ultimately to the differentiation of intracellular bacteroids as specialised nitrogen-fixing endosymbionts. The early stages of plant-microbe communication seem to be mostly mediated by the exchange of soluble, diffusible signal molecules: flavonoid compounds are secreted by plant roots, and chitin-like lipooligosaccharides are secreted by rhizobia. Further development of the nodule structure may involve the interplay of fairly conventional plant growth regulators. Direct physical contact between the cell surfaces of the symbionts also plays a prominent role in the process of tissue and cell invasion.}, }
@article {pmid7763501, year = {1993}, author = {Clark, MA and Baumann, P}, title = {Aspects of energy-yielding metabolism in the aphid, Schizaphis graminum, and its endosymbiont: detection of gene fragments potentially coding for the ATP synthase beta-subunit and glyceraldehyde-3-phosphate dehydrogenase.}, journal = {Current microbiology}, volume = {26}, number = {4}, pages = {233-237}, pmid = {7763501}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Bacteria/enzymology/*genetics ; Bacteroides ; Base Sequence ; Cloning, Molecular ; Energy Metabolism/genetics ; Genes, Bacterial/*genetics ; Glyceraldehyde-3-Phosphate Dehydrogenases/*genetics ; Molecular Sequence Data ; Proton-Translocating ATPases/*genetics ; Sequence Homology, Amino Acid ; Symbiosis/physiology ; }, abstract = {Specialized cells within the aphid, Schizaphis graminum, contain intracellular, vesicle-enclosed eubacterial endosymbionts (Buchnera aphidicola). Using oligonucleotide probes derived from conserved sequences of the ATP synthase beta-subunit and glyceraldehyde-3-phosphate dehydrogenase, and the polymerase chain reaction (PCR), we have amplified, cloned, and sequenced three DNA fragments. Amino acid sequence similarity indicated that two of these fragments corresponded to endosymbiont and host genes potentially coding for the beta-subunit of ATP synthase. The host gene fragment contained two putative introns. The third DNA fragment corresponded to a portion of a gene coding for a glyceraldehyde-3-phosphate dehydrogenase that was highly related to one of the enzymes from Escherichia coli (GapA). These results indicate that B. aphidicola may have an ATP synthase and consequently could synthesize ATP from a proton motive force generated within the intracellular vesicles of host cells containing the endosymbionts. The detection of a gene fragment coding for a protein similar to glyceraldehyde-3-phosphate dehydrogenase suggests the presence of this glycolytic enzyme in the endosymbiont and its involvement in energy-yielding metabolism.}, }
@article {pmid8490140, year = {1993}, author = {Luque, I and Flores, E and Herrero, A}, title = {Nitrite reductase gene from Synechococcus sp. PCC 7942: homology between cyanobacterial and higher-plant nitrite reductases.}, journal = {Plant molecular biology}, volume = {21}, number = {6}, pages = {1201-1205}, pmid = {8490140}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Base Sequence ; Cloning, Molecular ; Cyanobacteria/enzymology/*genetics ; DNA ; Molecular Sequence Data ; Nitrate Reductase ; Nitrate Reductases/*genetics/metabolism ; Plants/enzymology/*genetics ; Sequence Homology, Amino Acid ; }, abstract = {The gene encoding nitrite reductase (nir) from the cyanobacterium Synechococcus sp. PCC 7942 has been identified and sequenced. This gene comprises 1536 nucleotides and would encode a polypeptide of 56,506 Da that shows similarity to nitrite reductase from higher plants and to the sulfite reductase hemoprotein from enteric bacteria. Identities found at positions corresponding to those amino acids which in the above-mentioned proteins hold the Fe4S4-siroheme active center suggest that nitrite reductase from Synechococcus bears an active site much alike that present in those reductases. The fact that the Synechococcus and higher-plant nitrite reductases are homologous proteins gives support to the endosymbiont theory for the origin of chloroplasts.}, }
@article {pmid7763374, year = {1993}, author = {Campbell, BC}, title = {Congruent evolution between whiteflies (Homoptera: Aleyrodidae) and their bacterial endosymbionts based on respective 18S and 16S rDNAs.}, journal = {Current microbiology}, volume = {26}, number = {3}, pages = {129-132}, pmid = {7763374}, issn = {0343-8651}, mesh = {Animals ; Base Sequence ; Biological Evolution ; Cloning, Molecular ; DNA, Bacterial/genetics ; DNA, Ribosomal/*genetics ; Eubacterium/genetics ; Insecta/*genetics/*microbiology ; Molecular Sequence Data ; Polymerase Chain Reaction ; Symbiosis/*genetics ; }, abstract = {Whiteflies (family Aleyrodidae) possess heritable eubacterial endosymbionts sustained in specialized organ-like structure called mycetomes. Comparisons of distances between the ash whitefly, Siphoninus phillyreae, and two biotypes ("A" and "B") of the sweetpotato whitefly, Bemisia tabaci, based on sequence analysis of genes for 18S rRNAs (rDNAs), were equivalent to the distances represented by the 16S rDNAs of their respective endosymbionts. This finding indicates that evolutionary divergence in whitefly hosts and their endosymbionts is congruent. The nucleotide sequences of the 18S rDNAs and endosymbiont 16S rDNAs indicate the two biotypes of B. tabaci are the same species.}, }
@article {pmid8433382, year = {1993}, author = {Ohtaka, C and Ishikawa, H}, title = {Accumulation of adenine and thymine in a groE-homologous operon of an intracellular symbiont.}, journal = {Journal of molecular evolution}, volume = {36}, number = {2}, pages = {121-126}, pmid = {8433382}, issn = {0022-2844}, mesh = {Adenine/*metabolism ; Animals ; Aphids/microbiology ; Bacterial Proteins/*genetics/metabolism ; Base Sequence ; Biological Evolution ; *Chaperonins ; Cloning, Molecular ; Codon ; DNA, Bacterial ; Escherichia coli/genetics ; Escherichia coli Proteins ; Gram-Negative Bacteria/*genetics/metabolism ; Heat-Shock Proteins/*genetics/metabolism ; Molecular Sequence Data ; *Operon ; Sequence Homology, Nucleic Acid ; Symbiosis ; Thymine/*metabolism ; }, abstract = {As a result of the nucleotide sequence analysis of an aphid endosymbiont's operon homologous to the Escherichia coli groE, we noted that directional base substitutions tending toward an increase of A + T content represent an obvious evolutionary trend in this prokaryotic operon, housed for a long period by an eukaryotic cell. This result, when taken together with previous reports, raised the possibility that genomic DNA of prokaryotes residing in an eukaryotic cell is subject to A/T-biased directional mutation pressure and/or both negative and positive selection operating under conditions specific to the intracellular environments.}, }
@article {pmid8364689, year = {1993}, author = {Cary, SC and Warren, W and Anderson, E and Giovannoni, SJ}, title = {Identification and localization of bacterial endosymbionts in hydrothermal vent taxa with symbiont-specific polymerase chain reaction amplification and in situ hybridization techniques.}, journal = {Molecular marine biology and biotechnology}, volume = {2}, number = {1}, pages = {51-62}, pmid = {8364689}, issn = {1053-6426}, mesh = {Animals ; Annelida/*microbiology ; Bacteria/genetics/*isolation &amp; purification ; Base Sequence ; Computers ; DNA, Bacterial/isolation &amp; purification ; In Situ Hybridization ; Molecular Sequence Data ; Mollusca/*microbiology ; Nucleic Acid Conformation ; Oligonucleotide Probes ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/*chemistry/genetics/isolation &amp; purification ; Sensitivity and Specificity ; *Symbiosis ; }, abstract = {Invertebrates that contain endosymbiotic chemoautotrophic eubacteria are widely distributed in a variety of reducing marine habitats, including deepsea hydrothermal vents. The mechanisms of symbiont transmission in these invertebrates are not understood. To test the hypothesis that symbionts are transmitted via the eggs of hosts, we used group-specific hybridization probes complementary to 16S ribosomal RNAs (rRNAs) to look for symbionts in eggs and ovaries. 16S rRNA sequences were examined for domains unique to the symbionts of three vent animals: Calyptogena magnifica, Bathymodiolus thermophilus, and Riftia pachyptila. Three 16S rRNA-directed oligodeoxynucleotide hybridization probes (CG-1255R, RP-1243R, BT-1255R) specific for these endosymbionts were synthesized and evaluated by dot-blot hybridization. At higher stringencies, all three probes showed a high degree of specificity for their target endosymbionts rRNAs. The probes were also used as polymerase chain reaction (PCR) primers for detection of the symbiont 16S rRNA genes in genomic DNA isolated from host tissues known to contain symbionts. All three symbiont-specific probes were highly sensitive and specific as PCR primers; they successfully amplified 1 pg target DNA. However, all amplifications of extracted egg DNA from the vestimentiferan R. pachyptila with either universal eubacterial (Eub A/B) or the Riftia symbiont-specific (RP-1243R/Eub B) primer sets were unsuccessful. Nonradioactive in situ hybridizations were performed on ovarian tissue from the vestimentiferan Ridgea piscesae using RP-1243R, 3' end-labeled with digoxigenin-11-dUTP (Boehringer Mannheim). The probe was subsequently detected with an alkaline phosphatase-conjugated immunoglobulin G antibody specific for the digoxigenin moeity. The probe bound only to the tissue of R. pisceasae coincident with the known location of symbiont cells and was not detected in any region of the ovary. These data indicate that transovarial symbiont transmission in the vestimentiferans does not take place and that symbiont acquisition is probably a post-spawning event.}, }
@article {pmid8383274, year = {1993}, author = {Wieseler, B and Müller, M}, title = {Translocation of precytochrome c2 into intracytoplasmic membrane vesicles of Rhodobacter capsulatus requires a peripheral membrane protein.}, journal = {Molecular microbiology}, volume = {7}, number = {2}, pages = {167-176}, doi = {10.1111/j.1365-2958.1993.tb01108.x}, pmid = {8383274}, issn = {0950-382X}, mesh = {Bacterial Proteins/*metabolism ; Biological Transport, Active ; Cell-Free System ; Cytochrome c Group/*metabolism ; Electrochemistry ; Intracellular Membranes/*metabolism ; Membrane Proteins/*metabolism ; Osmolar Concentration ; Protein Precursors/*metabolism ; Proton-Translocating ATPases/antagonists &amp; inhibitors/metabolism ; Protons ; Recombinant Fusion Proteins/metabolism ; Rhodobacter capsulatus/*metabolism ; }, abstract = {Rhodobacter capsulatus is a member of the group of alpha-purple bacteria which are closely related to the ancestral endosymbiont that gave rise to mitochondria. It has therefore been hypothesized that the molecular mechanisms governing protein export in alpha-purple bacteria have been conserved during the evolution of mitochondria. To enable analysis of protein export in alpha-purple bacteria we describe here the development of a homologous cell-free synthesis/export system consisting entirely of components of R. capsulatus. Translocation of precytochrome c2 into intracytoplasmic membrane vesicles of this organism was found to require the proton-motive force and proceed at a significantly higher efficiency when membranes were present during protein synthesis. Furthermore, we show that, in this cell-free system, translocation depends on a preparation of peripheral membrane proteins which do not possess detectable SecA- and SecB-like activities.}, }
@article {pmid8365693, year = {1993}, author = {Stünkel, S and Alves, J and Kunstýr, I}, title = {Characterization of two "Metabacterium" sp. from the gut of rodents. 2. Heteroxenic cultivation and proof of dipicolinic acid in "M. polyspora".}, journal = {Folia microbiologica}, volume = {38}, number = {3}, pages = {171-175}, pmid = {8365693}, issn = {0015-5632}, mesh = {Animals ; Cecum/*microbiology ; Chromatography, High Pressure Liquid ; Gram-Negative Bacteria/growth &amp; development/*isolation &amp; purification/metabolism/ultrastructure ; Guinea Pigs ; Microscopy, Electron, Scanning ; Picolinic Acids/*metabolism ; }, abstract = {The vegetative cell of "Metabacterium polyspora" is "cucumber-shaped", about 21 x 5.7 microns, Gram-negative. Cylindrical endospores are best stained by Rakette and Ziehl-Neelsen staining. The bacterium reproduces by sporulation (2 to 8 endospores per cell) and by binary fission. Lateral, bow-like "hatching" of the endospores was seen. About 52% of guinea pigs harbor 5 x 10(6), 36% below 2 x 10(6) and 1% more than 1 x 10(8) "M. polyspora" in 1 g of caecal content. Dipicolinic acid was demonstrated using HPLC in the caecum homogenate from a guinea pig. The amount of it was proportional to the number of spores. Cultivation under strict anaerobic conditions did not succeed. It was possible to cultivate this giant endosymbiont in vitro in a heteroxenic culture incubated in a 5% CO2 atmosphere using liquid medium supplemented with cell-free filtrate of the caecum. The caecum filtrate containing undefined growth factor(s) is necessary for long-term culture. The replication rate was low. These findings suggest that the giant endosymbiont "M. polyspora" is a spore-forming prokaryote without the attributes of a strict anaerobe.}, }
@article {pmid8278337, year = {1993}, author = {Motta, MC and Soares, MJ and de Souza, W}, title = {Intracellular lectin-binding sites in symbiont-bearing Crithidia species.}, journal = {Parasitology research}, volume = {79}, number = {7}, pages = {551-558}, pmid = {8278337}, issn = {0932-0113}, mesh = {Amino Sugars/metabolism ; Animals ; Cell Nucleus/chemistry/ultrastructure ; Crithidia/*chemistry/microbiology/ultrastructure ; Endoplasmic Reticulum/chemistry/ultrastructure ; Flagella/chemistry/ultrastructure ; Histocytochemistry ; Lectins/metabolism ; Microscopy, Electron ; Monosaccharides/metabolism ; Receptors, Mitogen/*isolation &amp; purification ; *Symbiosis ; }, abstract = {Crithidia oncopelti, C. deanei, and C. desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Direct and indirect lectin-gold labeling techniques were used at the electron microscopic level in Lowicryl K4M-embedded cells to demonstrate the presence of intracellular lectin-binding sites. We used the lectins Ulex europaeus I, Griffonia simplicifolia II, Ricinus communis I, Arachis hypogaea, G. simplicifolia I, Wistaria floribunda, Limulus polyphemus, and Canavalia ensiformis, which recognize alpha-L-fucose, alpha- and beta-N-acetylglucosamine, beta-galactose and beta-N-acetylgalactosamine, beta-galactose, alpha-galactose, beta-N-acetylgalactosamine, sialic acid and alpha-D-mannose, and alpha-D-glucose residues, respectively. The nucleus was the cellular structure most frequently labeled by the lectins. The Golgi complex was seldom labeled, whereas the endoplasmic reticulum and the flagellar pocket presented a large number of binding sites. Symbionts had their two unit membranes weakly labeled by the different lectins but displayed no labeling of the space between the membranes.}, }
@article {pmid8269090, year = {1993}, author = {Beard, CB and O'Neill, SL and Mason, P and Mandelco, L and Woese, CR and Tesh, RB and Richards, FF and Aksoy, S}, title = {Genetic transformation and phylogeny of bacterial symbionts from tsetse.}, journal = {Insect molecular biology}, volume = {1}, number = {3}, pages = {123-131}, doi = {10.1111/j.1365-2583.1993.tb00113.x}, pmid = {8269090}, issn = {0962-1075}, support = {AI-08614/AI/NIAID NIH HHS/United States ; AI-10984/AI/NIAID NIH HHS/United States ; AI-28778/AI/NIAID NIH HHS/United States ; }, mesh = {Animals ; Base Sequence ; DNA, Bacterial/genetics ; Gram-Negative Bacteria/*classification/*genetics/isolation &amp; purification/ultrastructure ; Molecular Sequence Data ; Plasmids ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; Transformation, Genetic ; Trypanosoma/pathogenicity ; Trypanosomiasis/transmission ; Tsetse Flies/*microbiology/parasitology/ultrastructure ; }, abstract = {Two isolates of bacterial endosymbionts, GP01 and GM02, were established in cell free medium from haemolymph of the tsetse, Glossina pallidipes and G. morsitans. These microorganisms appear similar to rickettsia-like organisms reported previously from various tsetse species. The 16S rRNA sequence analysis, however, placed them within the gamma subdivision of the Proteobacteria, phylogenetically distinct from most members of the Rickettsiaceae which align with the alpha subdivision. Distinct multiple endogenous plasmids are harboured by GP01 and GM02, suggesting that the two isolates are different. Restriction mapping analysis showed that one of the conserved plasmids is present in high copy number and is at least 80 kb in size. A heterologous plasmid pSUP204, which contains the broad host range oriV replication origin, was used to transfect bacterial cultures. The symbiont GM02 was transformed, and it expressed plasmid encoded resistance to the antibiotics ampicillin, tetracycline and chloramphenicol. Transformation of these symbionts may provide a novel means for expressing anti-parasitic genes within tsetse populations.}, }
@article {pmid8096432, year = {1993}, author = {Ndiaye, M and Mattei, X}, title = {Endosymbiotic relationship between a rickettsia-like microorganism and the male germ-cells of Culex tigripes.}, journal = {Journal of submicroscopic cytology and pathology}, volume = {25}, number = {1}, pages = {71-77}, pmid = {8096432}, issn = {1122-9497}, mesh = {Animals ; Culicidae/*parasitology ; Host-Parasite Interactions ; Male ; *Rickettsia/ultrastructure ; Rickettsia Infections/*transmission ; Seminal Vesicles/ultrastructure ; Spermatogonia/*parasitology/ultrastructure ; Symbiosis ; Testis/parasitology/ultrastructure ; }, abstract = {The male mosquitoes of the species Culex tigripes possess endosymbionts localized in the cytoplasm of the germ-cells. The somatic cells of the testis do not exhibit this particularity. The spermatogonia, spermatocytes and spermatids all possess a few symbionts. They are eliminated in the residual body at the end of spermiogenesis when the spermatozoon matures. They are absent from the seminal vesicles. A few spermatocytes and spermatids show a proliferation of the endosymbionts. This seems to be associated with an abnormal spermiogenesis. These symbionts are comparable to the Wolbachia described in two other species of mosquitoes: Culex pipiens and Aedes scutellaris.}, }
@article {pmid8085789, year = {1993}, author = {Embley, TM and Finlay, BJ}, title = {Systematic and morphological diversity of endosymbiotic methanogens in anaerobic ciliates.}, journal = {Antonie van Leeuwenhoek}, volume = {64}, number = {3-4}, pages = {261-271}, pmid = {8085789}, issn = {0003-6072}, mesh = {Anaerobiosis ; Animals ; Base Sequence ; Ciliophora/*microbiology/ultrastructure ; Euryarchaeota/classification/*genetics/isolation &amp; purification ; Molecular Sequence Data ; Nucleic Acid Conformation ; Oligodeoxyribonucleotides ; *Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Ribosomal, 16S/analysis/chemistry/*genetics ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {The identities and taxonomic diversity of the endosymbiotic methanogens from the anaerobic protozoa Metopus contortus, Metopus striatus, Metopus palaeformis, Trimyema sp. and Pelomyxa palustris were determined by comparative analysis of their 16S ribosomal RNA sequences. Fluorescent oligonucleotide probes were designed to bind to the symbiont rRNA sequences and to provide direct visual evidence of their origins from methanogenic archaea contained within the host cells. Confocal microscopy was used to analyze the morphology of the endosymbionts in whole cells of Metopus palaeformis, Metopus contortus, Trimyema sp, and Cyclidium porcatum. The endosymbionts are taxonomically diverse and are drawn from three different genera; Methanobacterium, Methanocorpusculum and Methanoplanus. In every case the symbionts are closely related to, but different from, free-living methanogens for which sequences are available. It is thus apparent that symbioses have been formed repeatedly and independently. Ciliates which are unrelated to each other (Trimyema sp. and Metopus contortus) may contain symbionts which are closely related, and congeneric ciliates (Metopus palaeformis and M. contortus) may contain symbionts which are distantly related to each other. This suggests that some of the symbiotic associations must be relatively recent. For example, at least one of the symbioses in Metopus must postdate the speciation of M. palaeformis and M. contortus. Despite this, Metopus contortus, Trimyema sp., Cyclidium porcatum and their respective endosymbionts show sophisticated morphological interactions which probably facilitate the exchange of materials between the partners.}, }
@article {pmid7678762, year = {1993}, author = {Apt, KE and Grossman, AR}, title = {Characterization and transcript analysis of the major phycobiliprotein subunit genes from Aglaothamnion neglectum (Rhodophyta).}, journal = {Plant molecular biology}, volume = {21}, number = {1}, pages = {27-38}, pmid = {7678762}, issn = {0167-4412}, mesh = {Amino Acid Sequence ; Base Sequence ; Binding Sites ; Cloning, Molecular ; DNA/genetics/isolation &amp; purification ; Genes, Plant ; Light-Harvesting Protein Complexes ; Macromolecular Substances ; Molecular Sequence Data ; Operon ; Phycobilisomes ; Phycocyanin/genetics ; Phycoerythrin/genetics ; Pigments, Biological/*genetics ; Plant Proteins/*genetics ; RNA/genetics/isolation &amp; purification ; Restriction Mapping ; Rhodophyta/*genetics ; Ribosomes/metabolism ; Sequence Homology, Amino Acid ; Sequence Homology, Nucleic Acid ; *Transcription, Genetic ; }, abstract = {The genes encoding the alpha and beta subunits of allophycocyanin, phycocyanin and phycoerythrin from the red alga Aglaothamnion neglectum were isolated and characterized. While the operons containing the different phycobiliprotein genes are dispersed on the plastid genome, the genes encoding the alpha and beta subunits for each phycobiliprotein are contiguous. The beta subunit gene is 5' for both the phycocyanin and phycoerythrin operons, while the alpha subunit gene is 5' for the allophycocyanin operon. The amino acid sequences of A. neglectum phycobiliproteins, as deduced from the nucleotide sequences of the genes, are 65-85% identical to analogous proteins from other red algae and cyanobacteria. The conserved nature of the plastid-encoded red algal and cyanobacterial phycobiliprotein genes supports the proposed origin of red algal plastids from cyanobacterial endosymbionts. Many environmental factors effect phycobilisome biosynthesis. The effect of both nutrient availability and light quantity on the level of A. neglectum phycobiliprotein subunits and the mRNA species encoding those subunits is described.}, }
@article {pmid1361987, year = {1992}, author = {Rousset, F and Bouchon, D and Pintureau, B and Juchault, P and Solignac, M}, title = {Wolbachia endosymbionts responsible for various alterations of sexuality in arthropods.}, journal = {Proceedings. Biological sciences}, volume = {250}, number = {1328}, pages = {91-98}, doi = {10.1098/rspb.1992.0135}, pmid = {1361987}, issn = {0962-8452}, mesh = {Animals ; Base Sequence ; DNA, Ribosomal/genetics/*isolation &amp; purification ; Escherichia coli/genetics ; Female ; Insecta/genetics/*physiology ; Male ; Molecular Sequence Data ; Oligodeoxyribonucleotides ; Ovary ; Phylogeny ; Polymerase Chain Reaction ; Rickettsiaceae/*physiology ; Sequence Homology, Nucleic Acid ; *Sex Determination Analysis ; Testis ; Wasps/genetics/*physiology ; }, abstract = {Rickettsia-like maternally inherited bacteria have been shown to be involved in a variety of alterations of arthropod sexuality, such as female-biased sex ratios, parthenogenesis, and sterility of crosses either between infected males and uninfected females or between infected individuals (cytoplasmic incompatibility). We have characterized several of these microorganisms through partial sequences of the small (16S) and large (23S) subunit ribosomal DNA. All the symbionts identified, which include several cytoplasmic incompatibility microorganisms, several endosymbionts of terrestrial isopods, and symbionts of two thelytokous Trichogramma wasp species, belong to a monophyletic group of related symbionts, some of which have previously been detected in several insects exhibiting cytoplasmic incompatibility. Three molecular lineages can be identified on the basis of 16S as well as 23S sequences. Although they are only known as endocellular symbionts, Wolbachia spread by horizontal transfer across host lineages as evidenced by their diversification which occurred long after that of their hosts, and by the non-congruence of the phylogenetic relationships of symbionts and their hosts. Indeed, symbionts of two different lineages have been found in the same host species, whereas closely related endosymbionts are found in distinct insect orders. Isopod endosymbionts form a separate lineage, and they can determine feminization as well as cytoplasmic incompatibility. The ability to determine cytoplasmic incompatibility, found in all lineages, is probably ancestral to this group.}, }
@article {pmid1369199, year = {1992}, author = {Clark, MA and Baumann, L and Baumann, P}, title = {Sequence analysis of an aphid endosymbiont DNA fragment containing rpoB (beta-subunit of RNA polymerase) and portions of rplL and rpoC.}, journal = {Current microbiology}, volume = {25}, number = {5}, pages = {283-290}, pmid = {1369199}, issn = {0343-8651}, mesh = {Amino Acid Sequence ; Animals ; Aphids/genetics/*microbiology ; Base Sequence ; Codon/analysis ; DNA, Bacterial/*analysis ; DNA, Ribosomal/analysis ; DNA-Directed RNA Polymerases/*genetics/metabolism ; Eubacterium/*genetics ; *Genes, Bacterial ; Genetic Code ; Molecular Sequence Data ; Restriction Mapping ; *Symbiosis ; Transcription, Genetic ; }, abstract = {The aphid Schizaphis graminum is dependent on an association with a prokaryotic endosymbiont (Buchnera aphidicola). The nucleotide (nt) sequence of a 5040 base pair (bp) DNA fragment of B. aphidicola, homologous to the rplL-rpoB-rpoC portion of the Escherichia coli beta operon, was determined. The DNA coded for the terminal 35 amino acids of RplL (large ribosomal subunit protein L7/L12), the complete RpoB (beta-subunit of RNA polymerase), and the first 209 amino acids of RpoC (beta'-subunit of RNA polymerase). The deduced sequences of B. aphidicola RplL, RpoB, and RpoC were 71, 84, and 91% identical, respectively, to the homologous proteins of E. coli. The sequences of two portions of the intergenic region between rplL and rpoB were nearly identical in both B. aphidicola and E. coli. One sequence constituted an inverted repeat that could be an RNase III-messenger RNA processing site; the other sequence preceded RpoB. A compilation of the codon usage for RpoB, RpoC, and other B. aphidicola proteins indicated a major preference for A or T in the first and third positions, a result consistent with the low guanine plus cytosine (G + C) content of the DNA of this organism.}, }
@article {pmid1398077, year = {1992}, author = {Lai, CY and Baumann, P}, title = {Sequence analysis of a DNA fragment from Buchnera aphidicola (an endosymbiont of aphids) containing genes homologous to dnaG, rpoD, cysE, and secB.}, journal = {Gene}, volume = {119}, number = {1}, pages = {113-118}, doi = {10.1016/0378-1119(92)90074-y}, pmid = {1398077}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Aphids/microbiology ; Bacterial Proteins/*genetics ; Base Sequence ; *DNA, Bacterial ; *DNA-Directed RNA Polymerases ; Escherichia coli/genetics ; Gene Expression Regulation, Bacterial ; Gram-Negative Bacteria/*genetics ; Molecular Sequence Data ; Sigma Factor/*genetics ; Symbiosis ; }, abstract = {The aphid, Schizaphis graminum, contains a prokaryotic, obligately intracellular endosymbiont, Buchnera aphidicola, which is necessary for the survival of the host. A recent study of Bu. aphidicola 16S rRNA has indicated that it is a member of the gamma-3 subdivision of the eubacterial class, Proteobacteria, which includes Escherichia coli. In order to further characterize the endosymbiont and establish its similarity to free-living eubacteria and/or organelles, we have cloned and sequenced a 4534-bp DNA fragment containing dnaG-rpoD-cysE-secB. The deduced amino acid (aa) sequence identity to the homologous E. coli proteins ranged from 47 to 80%. The close proximity of the pair, dnaG-rpoD, to the pair, cysE-secB, on the Bu. aphidicola DNA, differed from E. coli, in which these two pairs of genes are 14 min apart on the bacterial chromosome. The results of past physiological studies of the endosymbiont were consistent with the presence and function of DNA primase (DnaG), sigma factor (RpoD) and components of the secretory system (SecB). Comparison of the deduced aa sequence of Bu. aphidicola CysE (serine acetyltransferase, a key allosterically regulated enzyme in cysteine biosynthesis) with the E. coli wild-type enzyme and a mutant defective in feedback inhibition suggested that the endosymbiont CysE may not be regulated. By analogy with E. coli, the lack of feedback inhibition may lead to overproduction of cysteine by the endosymbiont. The results of this and previous investigations indicate that Bu. aphidicola has many of the properties of free-living bacteria and not of organelles.}, }
@article {pmid1514803, year = {1992}, author = {Gijzen, HJ and Barugahare, M}, title = {Contribution of anaerobic protozoa and methanogens to hindgut metabolic activities of the American cockroach, Periplaneta americana.}, journal = {Applied and environmental microbiology}, volume = {58}, number = {8}, pages = {2565-2570}, pmid = {1514803}, issn = {0099-2240}, mesh = {Anaerobiosis ; Animals ; Ciliophora/*metabolism ; Cockroaches/metabolism/*microbiology/*parasitology ; Digestive System/metabolism/microbiology/parasitology ; Euryarchaeota/*metabolism ; Fatty Acids/biosynthesis ; Methane/metabolism ; Symbiosis ; }, abstract = {The ciliate Nyctotherus ovalis occurs in high numbers in the hindgut of the American cockroach (Periplaneta americana) and harbors methanogenic bacteria as endosymbionts. The contribution of these hindgut microorganisms to metabolic and developmental processes of P. americana was studied by comparing cultures of cockroaches in which the composition of the hindgut microbial population was altered in various ways. Rearing the insects protozoan free resulted in increased insect generation time, decreased adult body weight, and absence of methane production. After feeding of protozoan-free adult cockroaches with a hindgut suspension containing N. ovalis and methanogens, methane increased to normal values and insect body weight was restored during the development of the second generation of insects. Feeding the protozoan-free cockroaches a hindgut suspension which was made free of N. ovalis resulted in an increase in methane production to only about 20% of the normal methane production level. This suggests that the methanogenic endosymbionts of N. ovalis are the major source of methane production in the hindgut. Inhibition of methanogens by addition of bromoethanesulfonic acid to the drinking water of a normal cockroach culture resulted in a reduction of methane production to about 2% of the normal level. No effects on insect body weight or the number of N. ovalis organisms were observed, but the fermentation pattern in the hindgut was shifted towards a relative increase in propionate levels. Similar results were obtained for in vitro cultures of hindgut microorganisms treated with bromoethanesulfonic acid. The results suggest a major role for hindgut protozoa in cockroach metabolic activities, especially during the insect growth period. The relatively large amounts of methane produced by cockroaches and by other methane-producing xylophagous insects suggest a major contribution by insects to global methane production.}, }
@article {pmid1512578, year = {1992}, author = {Embley, TM and Finlay, BJ and Thomas, RH and Dyal, PL}, title = {The use of rRNA sequences and fluorescent probes to investigate the phylogenetic positions of the anaerobic ciliate Metopus palaeformis and its archaeobacterial endosymbiont.}, journal = {Journal of general microbiology}, volume = {138}, number = {7}, pages = {1479-1487}, doi = {10.1099/00221287-138-7-1479}, pmid = {1512578}, issn = {0022-1287}, mesh = {Animals ; Archaea/*classification ; Base Sequence ; Ciliophora/*classification/microbiology ; DNA, Bacterial/chemistry ; DNA, Protozoan/chemistry ; DNA, Ribosomal/*chemistry ; Fluorescent Dyes ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal/*genetics ; *Symbiosis ; }, abstract = {The polymerase chain reaction (PCR) was used to amplify small-subunit ribosomal DNA from the anaerobic ciliated protozoon Metopus palaeformis, and from its uncultured endosymbiotic bacteria. This was accomplished directly from total DNA extracted from protozoa without prior isolation or enrichment for symbiont cells. The double-stranded amplification products were precipitated and directly sequenced using the linear PCR reaction. Fluorescent oligonucleotide probes were designed and used in whole-cell hybridizations to provide direct visual evidence that the sequences originated from the host ciliate and from the endosymbiont. Phylogenetic analysis of the Metopus palaeformis sequence consistently placed it as a deep-branching lineage near the root of the ciliate tree. However, the present data were insufficient to resolve the detailed relationship between Blepharisma and Metopus and thus to determine if the heterotrichs are mono- or paraphyletic. Phylogenetic analysis of the symbiont partial sequence clearly demonstrated that it is an archaeobacterium and that it is closely related to, but distinct from, Methanobacterium formicicum.}, }
@article {pmid1597427, year = {1992}, author = {Agron, PG and Ditta, GS and Helinski, DR}, title = {Mutational analysis of the Rhizobium meliloti nifA promoter.}, journal = {Journal of bacteriology}, volume = {174}, number = {12}, pages = {4120-4129}, pmid = {1597427}, issn = {0021-9193}, support = {89-6685//PHS HHS/United States ; }, mesh = {Bacterial Proteins/*genetics ; Base Sequence ; DNA Mutational Analysis ; Gene Expression Regulation, Bacterial/*genetics ; Molecular Sequence Data ; Mutagenesis, Site-Directed/genetics ; Plasmids/genetics ; Promoter Regions, Genetic/*genetics ; Recombinant Fusion Proteins/genetics ; Sinorhizobium meliloti/*genetics ; Transcription Factors/*genetics ; }, abstract = {The nifA gene of Rhizobium meliloti, the bacterial endosymbiont of alfalfa, is a regulatory nitrogen fixation gene required for the induction of several key nif and fix genes. Transcription of nifA is strongly induced in planta and under microaerobic conditions ex planta. Induction of nifA, in turn, is positively controlled by the fixL and fixJ genes of R. meliloti, the sensor and regulator, respectively, of a two-component system responsible for oxygen sensing by this bacterium. This system is also responsible for the positive induction of fixK. Here, we report that chemical and oligonucleotide site-directed mutageneses of the nifA promoter (nifAp) were conducted to identify nucleotides essential for induction. Nineteen mutants, including 14 single-point mutants, were analyzed for microaerobic induction of nifAp in R. meliloti. Critical residues were identified in an upstream region between base pairs -54 and -39 relative to the transcription start site. Attempts at separating the upstream and downstream regions of the nifA promoter so as to maintain fixJ-dependent activity were unsuccessful. A 5' deletion of the fixK promoter (fixKp) to -67 indicates that sequences upstream of this position are not required for microaerobic induction. A sequence comparison of the -54 to -39 region of nifAp with the upstream sequences of fixKp does not reveal a block of identical nucleotides that could account for the fixJ-dependent microaerobic induction of both promoters. Many of the defective nifAp mutants in this region, however, are in residues with identity to fixKp in an alignment of the promoters according to their transcription start sites. Therefore, it is possible that there is a common sequence motif in the -54 to -39 region of the two promoters that is required for fixLJ-dependent microaerobic induction.}, }
@article {pmid1579169, year = {1992}, author = {Reinhold-Hurek, B and Shub, DA}, title = {Self-splicing introns in tRNA genes of widely divergent bacteria.}, journal = {Nature}, volume = {357}, number = {6374}, pages = {173-176}, doi = {10.1038/357173a0}, pmid = {1579169}, issn = {0028-0836}, mesh = {Base Sequence ; *Genes, Bacterial ; Genetic Variation ; Gram-Negative Facultatively Anaerobic Rods/*genetics ; *Introns ; Molecular Sequence Data ; Nucleic Acid Conformation ; Oligodeoxyribonucleotides ; *RNA Splicing ; RNA, Transfer/*genetics ; RNA, Transfer, Arg/chemistry/genetics ; RNA, Transfer, Ile/chemistry/genetics ; RNA, Transfer, Leu/chemistry/genetics ; Rhizobium/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {The organization of eukaryotic genes into exons separated by introns has been considered as a primordial arrangement but because it does not exist in eubacterial genomes it may be that introns are relatively recent acquisitions. A self-splicing group I intron has been found in cyanobacteria at the same position of the same gene (that encoding leucyl transfer RNA, UAA anticodon) as a similar group I intron of chloroplasts, which indicates that this intron predates the invasion of eukaryotic cells by cyanobacterial endosymbionts. But it is not clear from this isolated example whether introns are more generally present in different genes or in more diverse branches of the eubacteria. Many mitochondria have intron-rich genomes and were probably derived from the alpha subgroup of the purple bacteria (or Proteobacteria), so ancient introns might also have been retained in these bacteria. We describe here the discovery of two small (237 and 205 nucleotides) self-splicing group I introns in members of two proteobacterial subgroups, Agrobacterium tumefaciens (alpha) and Azoarcus sp. (beta). The introns are inserted in genes for tRNA(Arg) and tRNA(Ile), respectively, after the third anticodon nucleotide. Their occurrence in different genes of phylogenetically diverse bacteria indicates that group I introns have a widespread distribution among eubacteria.}, }
@article {pmid1526126, year = {1992}, author = {Conway, NM and McDowell Capuzzo, JE}, title = {High taurine levels in the Solemya velum symbiosis.}, journal = {Comparative biochemistry and physiology. B, Comparative biochemistry}, volume = {102}, number = {1}, pages = {175-185}, doi = {10.1016/0305-0491(92)90292-y}, pmid = {1526126}, issn = {0305-0491}, mesh = {Amino Acids/metabolism ; Animals ; Bacteria/metabolism ; Bivalvia/metabolism ; Mollusca/*metabolism/microbiology ; Proteins/metabolism ; Species Specificity ; Symbiosis/physiology ; Taurine/*metabolism ; }, abstract = {1. To compare biochemical differences between bivalves with and without endosymbiotic chemoautotrophic bacteria, specimens of Solemya velum, a bivalve species known to contain bacterial endosymbionts, and the symbiont-free soft-shelled clam Mya arenaria, were collected from the same subtidal reducing sediments during October and November 1988. 2. Total and free amino acid compositions were determined for both species. Protein-bound amino acids were calculated as the difference between total and free amino acids. In addition, stable isotope ratios of the total and free amino acids of each species were measured to determine potential sources for these molecules. 3. Both species had similar total hydrolyzable- and protein-bound amino acid compositions; approximately 50% of the protein-bound amino acids were essential amino acids. In S. velum, the small size of the digestive system suggests that these amino acids are probably synthesized by the endosymbiotic bacteria and translocated to the animal tissue. The delta 13C and delta 15N ratios of the amino acids are very similar to the isotope ratios previously found in both the endosymbionts and whole tissues of S. velum. The relative and absolute amounts of free amino acids are very different in the two species. In S. velum, the absolute concentrations of taurine, a sulfur-containing amino acid, were greater than the total free amino acid concentrations found in other bivalves. 4. The delta 34S ratios of the free amino acids of S. velum, which were predominantly composed of taurine, were extremely negative (-17.2/1000) suggesting that taurine is synthesized using sulfur originally derived from external reduced sulfur sources, such as pore water sulfides. The possible roles for taurine in this animal-bacteria symbiosis are discussed.}, }
@article {pmid1572539, year = {1992}, author = {Lai, CY and Baumann, P}, title = {Genetic analysis of an aphid endosymbiont DNA fragment homologous to the rnpA-rpmH-dnaA-dnaN-gyrB region of eubacteria.}, journal = {Gene}, volume = {113}, number = {2}, pages = {175-181}, doi = {10.1016/0378-1119(92)90393-4}, pmid = {1572539}, issn = {0378-1119}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Base Sequence ; Chromosomes, Bacterial ; DNA, Bacterial/*genetics ; Gram-Negative Bacteria/*genetics ; Molecular Sequence Data ; Regulatory Sequences, Nucleic Acid ; Restriction Mapping ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {Buchnera aphidicola is a Gram- eubacterium with a DNA G+C content of 28-30 mol%. This organism is an obligate intracellular symbiont of aphids. To determine its similarity to or difference from other eubacteria, a 4.9-kb DNA fragment from B. aphidicola containing the gene homologous to Escherichia coli dnaA (a gene involved in the initiation of chromosome replication) was cloned into E. coli and sequenced. The order of genes on this fragment, 60K-10K-rnpA-rpmH-dnaA-dnaN-gyrB, was similar to that found in other eubacteria. The sole difference was the absence of recF between dnaN and gyrB. The deduced amino acid sequence of these proteins resembled those of E. coli by a 41 to 83% identity. Except for E. coli, in all the eubacteria so far examined, dnaA is preceded by multiple 9-nucleotide repeats known as a DnaA boxes. No DnaA boxes were detected in the endosymbiont DNA. The possibility that this observation is a consequence of the low G+C content of this DNA fragment (14 mol% G+C) is unlikely since in Mycoplasma capricolum this fragment (19 mol% G+C) has eight DnaA boxes (Fujita et al., 1992). The presence of the sequence, GATC, recognized by the Dam methyl-transferase system, only within six regions coding for proteins suggests that methylation is not a factor in the regulation of the initiation of endosymbiont chromosome replication.}, }
@article {pmid1565660, year = {1992}, author = {Rowan, R and Powers, DA}, title = {Ribosomal RNA sequences and the diversity of symbiotic dinoflagellates (zooxanthellae).}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {89}, number = {8}, pages = {3639-3643}, pmid = {1565660}, issn = {0027-8424}, mesh = {Animals ; Base Sequence ; DNA/genetics/isolation &amp; purification ; Dinoflagellida/*genetics/physiology ; *Genetic Variation ; Molecular Sequence Data ; Oligodeoxyribonucleotides ; *Phylogeny ; Polymerase Chain Reaction/methods ; RNA, Ribosomal/*genetics ; Sequence Homology, Nucleic Acid ; Species Specificity ; Symbiosis ; }, abstract = {Zooxanthellae are unicellular algae that occur as endosymbionts in many hundreds of common marine invertebrates. The issue of zooxanthella diversity has been difficult to address. Most zooxanthellae have been placed in the dinoflagellate genus Symbiodinium as one or several species that are not easily distinguished. We compared Symbiodinium and nonsymbiotic dinoflagellates using small ribosomal subunit RNA sequences. Surprisingly, small ribosomal subunit RNA diversity within the genus Symbiodinium is comparable to that observed among different orders of nonsymbiotic dinoflagellates. These data reinforce the conclusion that Symbiodinium-like zooxanthellae represent a collection of distinct species and provide a precedent for a molecular genetic taxonomy of the genus Symbiodinium.}, }
@article {pmid1618730, year = {1992}, author = {Morioka, M and Ishikawa, H}, title = {Mutualism based on stress: selective synthesis and phosphorylation of a stress protein by an intracellular symbiont.}, journal = {Journal of biochemistry}, volume = {111}, number = {4}, pages = {431-435}, doi = {10.1093/oxfordjournals.jbchem.a123774}, pmid = {1618730}, issn = {0021-924X}, mesh = {Animals ; Aphids ; Bacterial Proteins/metabolism ; *Chaperonins ; Heat-Shock Proteins/biosynthesis/chemistry/*metabolism ; Intracellular Fluid/metabolism ; Male ; Molecular Weight ; Phosphorylation ; Rabbits ; Symbiosis/*physiology ; }, abstract = {The effects of a temperature shift-up and various metabolic inhibitors on the protein synthesis of an endosymbiont isolated from the pea aphid were studied. The syntheses of at least three major polypeptides were stimulated transiently immediately after a temperature shift-up, and treatment with ethanol and heavy metals (Cd2+ and As2+). One of these proteins, the 63 kDa heat-shock protein (63-kDa HSP), was immunoprecipitated with antiserum raised against symbionin, which is selectively synthesized by the endosymbiont harbored by the aphid bacteriocytes. The 63 kDa heat-shock protein has a molecular mass of 800 kDa and is more acidic than symbionin. It was also shown that symbionin is subject to phosphorylation in vivo and in vitro after a temperature shift-up. It was thought likely that forms of environmental stress such as heat shock and metabolic inhibitors stimulate the synthesis of a phosphorylated form of symbionin. It was also suggested that the in vitro phosphorylation of symbionin is due to its own catalytic activity. Since symbionin is a homolog of the Escherichia coli groEL protein, a stress protein, it is likely that the endosymbiont suffers stress when harbored by the bacteriocytes and responds in a similar manner to environmental stress when outside these cells.}, }
@article {pmid1557375, year = {1992}, author = {O'Neill, SL and Giordano, R and Colbert, AM and Karr, TL and Robertson, HM}, title = {16S rRNA phylogenetic analysis of the bacterial endosymbionts associated with cytoplasmic incompatibility in insects.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {89}, number = {7}, pages = {2699-2702}, pmid = {1557375}, issn = {0027-8424}, mesh = {Animals ; Bacteria/*genetics ; Bacterial Infections/diagnosis/veterinary ; Base Sequence ; Insecta/genetics/*microbiology ; Molecular Sequence Data ; Oligodeoxyribonucleotides/chemistry ; RNA, Ribosomal, 16S/*genetics ; Symbiosis ; }, abstract = {Bacterial endosymbionts of insects have long been implicated in the phenomenon of cytoplasmic incompatibility, in which certain crosses between symbiont-infected individuals lead to embryonic death or sex ratio distortion. The taxonomic position of these bacteria has, however, not been known with any certainty. Similarly, the relatedness of the bacteria infecting various insect hosts has been unclear. The inability to grow these bacteria on defined cell-free medium has been the major factor underlying these uncertainties. We circumvented this problem by selective PCR amplification and subsequent sequencing of the symbiont 16S rRNA genes directly from infected insect tissue. Maximum parsimony analysis of these sequences indicates that the symbionts belong in the alpha-subdivision of the Proteobacteria, where they are most closely related to the Rickettsia and their relatives. They are all closely related to each other and are assigned to the type species Wolbachia pipientis. Lack of congruence between the phylogeny of the symbionts and their insect hosts suggest that horizontal transfer of symbionts between insect species may occur. Comparison of the sequences for W. pipientis and for Wolbachia persica, an endosymbiont of ticks, shows that the genus Wolbachia is polyphyletic. A PCR assay based on 16S primers was designed for the detection of W. pipientis in insect tissue, and initial screening of insects indicates that cytoplasmic incompatibility may be a more general phenomenon in insects than is currently recognized.}, }
@article {pmid1350096, year = {1992}, author = {Rousset, F and Vautrin, D and Solignac, M}, title = {Molecular identification of Wolbachia, the agent of cytoplasmic incompatibility in Drosophila simulans, and variability in relation with host mitochondrial types.}, journal = {Proceedings. Biological sciences}, volume = {247}, number = {1320}, pages = {163-168}, doi = {10.1098/rspb.1992.0023}, pmid = {1350096}, issn = {0962-8452}, mesh = {Animals ; Base Sequence ; Cytoplasm/microbiology ; DNA, Bacterial/genetics ; DNA, Mitochondrial/genetics ; Drosophila/genetics/*microbiology ; Female ; Male ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/genetics ; Rickettsiaceae/*genetics/isolation &amp; purification ; Sequence Homology, Nucleic Acid ; Symbiosis ; }, abstract = {Sequences of a segment of the 16S ribosomal DNA of Wolbachia, a rickettsia-like microorganism responsible for cytoplasmic incompatibility in Drosophila simulans, have been obtained after polymerase chain reaction (PCR) amplification. Their comparison with other eubacterial sequences allows us to assign these endosymbionts to the alpha subdivision of purple bacteria. Four related sequences have been obtained for microorganisms carried by eight isofemale lines representative of the three mitochondrial types of D. simulans. Their phylogeny and level of divergence do not parallel that of the mitochondrial DNA, suggesting that several independent infections occurred. There is no direct relation between bacterial phylogeny and formerly identified incompatibility types.}, }
@article {pmid1347769, year = {1992}, author = {Ohtaka, C and Nakamura, H and Ishikawa, H}, title = {Structures of chaperonins from an intracellular symbiont and their functional expression in Escherichia coli groE mutants.}, journal = {Journal of bacteriology}, volume = {174}, number = {6}, pages = {1869-1874}, pmid = {1347769}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Animals ; Aphids/*microbiology ; Bacterial Proteins/chemistry/*genetics ; Base Sequence ; Chaperonin 10 ; Chaperonin 60 ; Chaperonins ; Cloning, Molecular ; Gene Expression Regulation, Bacterial ; Genes, Bacterial ; Genetic Complementation Test ; Heat-Shock Proteins/genetics ; Hydrogen Bonding ; Molecular Sequence Data ; Nucleic Acid Conformation ; Operon ; Promoter Regions, Genetic ; Proteins/chemistry/*genetics ; Restriction Mapping ; Sequence Alignment ; Symbiosis ; }, abstract = {An intracellular symbiont harbored by the aphid bacteriocyte, a specialized fat body cell, synthesizes in vivo substantially only one protein, symbionin, which is a member of the chaperonin-60 family of molecular chaperones. Nucleotide sequence determination of the symbionin region of the endosymbiont genome revealed that it contains the two-cistron operon sym. Just like the Escherichia coli groE operon, the sym operon was dually led by a heat shock and an ordinary promoter sequence. According to the nucleotide sequence, symbionin was 85.5% identical to GroEL of E. coli at the amino acid sequence level. SymS, another protein encoded in the sym operon, which is a member of chaperonin-10, was 79.6% identical to GroES. Complementation experiments with E. coli groE mutants showed that the chaperonin-10 and chaperonin-60 genes from the endosymbiont are expressed in E. coli and that they can function as molecular chaperones together with endogenous GroEL and GroES, respectively.}, }
@article {pmid1342920, year = {1992}, author = {Munson, MA and Baumann, P and Moran, NA}, title = {Phylogenetic relationships of the endosymbionts of mealybugs (Homoptera: Pseudococcidae) based on 16S rDNA sequences.}, journal = {Molecular phylogenetics and evolution}, volume = {1}, number = {1}, pages = {26-30}, doi = {10.1016/1055-7903(92)90032-c}, pmid = {1342920}, issn = {1055-7903}, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; DNA Primers/genetics ; DNA, Bacterial/*genetics ; DNA, Ribosomal/*genetics ; Gram-Negative Bacteria/classification/*genetics ; Hemiptera/*microbiology ; Molecular Sequence Data ; *Phylogeny ; Polymerase Chain Reaction ; RNA, Ribosomal, 16S/genetics ; Sequence Homology, Nucleic Acid ; Symbiosis/*genetics ; }, abstract = {A portion of the gene coding for the 16S ribosomal RNA from the endosymbionts of three species of mealybugs [Pseudococcus longispinus (Targioni-Tozzetti), Pseudococcus maritimus (Ehrhorn), and Dysmicoccus neobrevipes (Beardsley)] was cloned, sequenced, and compared to a homologous fragment from bacteria representative of aphid endosymbionts as well as major subdivisions of the Proteobacteria. Parsimony analysis of the sequences indicated that the mealybug endosymbionts are related and belong to the beta-subdivision; in contrast, previous studies showed that aphid endosymbionts are part of the gamma-subdivision. These findings suggest that the endosymbiosis of mealybugs is a consequence of a single bacterial infection and indicate that this ancestor was different from the ancestor involved in aphid endosymbiosis.}, }
@article {pmid1556750, year = {1992}, author = {Lockhart, PJ and Howe, CJ and Bryant, DA and Beanland, TJ and Larkum, AW}, title = {Substitutional bias confounds inference of cyanelle origins from sequence data.}, journal = {Journal of molecular evolution}, volume = {34}, number = {2}, pages = {153-162}, pmid = {1556750}, issn = {0022-2844}, mesh = {Base Composition ; *Biological Evolution ; Chloroplasts ; Eukaryota/classification/*genetics ; *Organelles ; *Phylogeny ; Plants/genetics ; }, abstract = {Available molecular and biochemical data offer conflicting evidence for the origin of the cyanelle of Cyanophora paradoxa. We show that the similarity of cyanelle and green chloroplast sequences is probably a result of these two lineages independently developing the same pattern of directional nucleotide change (substitutional bias). This finding suggests caution should be exercised in the interpretation of nucleotide sequence analyses that appear to favor the view of a common endosymbiont for the cyanelle and chlorophyll-b-containing chloroplasts. The data and approaches needed to resolve the issue of cyanelle origins are discussed. Our findings also have general implications for phylogenetic inference under conditions where the base compositions (compositional bias) of the sequences analyzed differ.}, }
@article {pmid1452433, year = {1992}, author = {Gray, MW}, title = {The endosymbiont hypothesis revisited.}, journal = {International review of cytology}, volume = {141}, number = {}, pages = {233-357}, doi = {10.1016/s0074-7696(08)62068-9}, pmid = {1452433}, issn = {0074-7696}, mesh = {Animals ; Bacteria/genetics ; *Biological Evolution ; DNA, Mitochondrial/genetics ; Eukaryotic Cells ; *Mitochondria ; *Models, Biological ; *Organelles ; Phylogeny ; Plants/genetics ; RNA, Ribosomal/genetics ; *Symbiosis ; }, }
@article {pmid1438362, year = {1992}, author = {Yang, SY}, title = {The fadBA operon of Escherichia coli and evidence for the endosymbiont origin of peroxisomes.}, journal = {Progress in clinical and biological research}, volume = {375}, number = {}, pages = {183-188}, pmid = {1438362}, issn = {0361-7742}, mesh = {3-Hydroxyacyl CoA Dehydrogenases/genetics ; Acetyl-CoA C-Acyltransferase/genetics ; *Biological Evolution ; Enoyl-CoA Hydratase/genetics ; Escherichia coli/*genetics ; Microbodies/*metabolism ; Operon/*genetics ; Symbiosis/*genetics ; }, }
@article {pmid1292670, year = {1992}, author = {Cavalier-Smith, T}, title = {The number of symbiotic origins of organelles.}, journal = {Bio Systems}, volume = {28}, number = {1-3}, pages = {91-106; discussion 107-8}, doi = {10.1016/0303-2647(92)90011-m}, pmid = {1292670}, issn = {0303-2647}, mesh = {*Biological Evolution ; Chloroplasts/ultrastructure ; Eukaryotic Cells/ultrastructure ; Mitochondria/ultrastructure ; Models, Biological ; *Organelles/ultrastructure ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {Mitochondria and chloroplasts both originated from bacterial endosymbionts. The available evidence strongly supports a single origin for mitochondria and only somewhat less strongly a single, slightly later, origin for chloroplasts. The arguments and evidence that have sometimes been presented in favor of the alternative theories of the multiple or polyphyletic origins of these two organelles are evaluated and the kinds of data that are needed to test more rigorously the monophyletic theory are discussed. Although chloroplasts probably originated only once, eukaryotic algae are polyphyletic because chloroplasts have been secondarily transferred to new lineages by the permanent incorporation of a photosynthetic eukaryotic algal cell into a phagotrophic protozoan host. How often this has happened is much less clear. It is particularly unclear whether or not the chloroplasts of typical dinoflagellates and euglenoids originated in this way from a eukaryotic symbiont: their direct divergence from the ancestral chloroplast cannot be ruled out and indeed has several arguments in its favor. The evidence for and against the view that the chloroplast of the kingdom Chromista was acquired in a single endosymbiotic event is discussed. The possibility that even the chloroplast of Chlorarachnion might have been acquired during the same symbiosis that created the cryptomonad cell, if the symbiont was a primitive alga that had chlorophyll a, b and c as well as phycobilins, is also considered. An alga with such a combination of pigments might have been ancestral to all eukaryote algae.}, }
@article {pmid1292667, year = {1992}, author = {Douglas, SE}, title = {Eukaryote-eukaryote endosymbioses: insights from studies of a cryptomonad alga.}, journal = {Bio Systems}, volume = {28}, number = {1-3}, pages = {57-68}, doi = {10.1016/0303-2647(92)90008-m}, pmid = {1292667}, issn = {0303-2647}, mesh = {Amino Acid Sequence ; Chromosome Mapping ; Eukaryota/classification/*genetics ; Molecular Sequence Data ; Multigene Family ; Photosynthesis/genetics ; Phylogeny ; Proteins/genetics ; RNA, Ribosomal/genetics ; Sequence Homology, Amino Acid ; Symbiosis/genetics ; }, abstract = {It has been proposed that those plants which contain photosynthetic plastids surrounded by more than two membranes have arisen through secondary endosymbiotic events. Molecular evidence confirms this proposal, but the nature of the endosymbiont(s) and the number of endosymbioses remain unresolved. Whether plastids arose from one type of prokaryotic ancestor or multiple types is the subject of some controversy. In order to try to resolve this question, the plastid gene content and arrangement has been studied from a cryptomonad alga. Most of the gene clusters common to photosynthetic prokaryotes and plastids are preserved and seventeen genes which are not found on the plastid genomes of land plants have been found. Together with previously published phylogenetic analyses of plastid genes, the present data support the notion that the type of prokaryote involved in the initial endosymbiosis was from within the cyanobacterial assemblage and that an early divergence giving rise to the green plant lineage and the rhodophyte lineage resulted in the differences in plastid gene content and sequence between these two groups. Multiple secondary endosymbiotic events involving a eukaryotic (probably rhodophytic alga) and different hosts are hypothesized to have occurred subsequently, giving rise to the chromophyte, cryptophyte and euglenophyte lineages.}, }
@article {pmid1959634, year = {1991}, author = {Pulgar, V and Gaete, L and Allende, J and Orellana, O and Jordana, X and Jedlicki, E}, title = {Isolation and nucleotide sequence of the Thiobacillus ferrooxidans genes for the small and large subunits of ribulose 1,5-bisphosphate carboxylase/oxygenase.}, journal = {FEBS letters}, volume = {292}, number = {1-2}, pages = {85-89}, doi = {10.1016/0014-5793(91)80840-y}, pmid = {1959634}, issn = {0014-5793}, mesh = {Amino Acid Sequence ; Base Sequence ; Chromosomes, Bacterial ; Cloning, Molecular ; DNA, Bacterial/genetics ; *Genes, Bacterial ; Molecular Sequence Data ; Restriction Mapping ; Ribulose-Bisphosphate Carboxylase/*genetics ; Sequence Homology, Nucleic Acid ; Thiobacillus/*genetics ; }, abstract = {The genes encoding for the large (rbcL) and small (rbcS) subunits of ribulose-1,5-bisphosphate carboxylase (RuBisCO) were cloned from the obligate autotroph Thiobacillus ferrooxidans, a bacterium involved in the bioleaching of minerals. Nucleotide sequence analysis of the cloned DNA showed that the two coding regions are separated by a 30-bp intergenic region, the smallest described for the RuBisCO genes. The rbcL and rbcS genes encode polypeptides of 473 and 118 amino acids, respectively. Comparison of the nucleotide and amino acid sequences with those of the genes for rbcL and rbcS found in other species demonstrated that the T. ferrooxidans genes have the closest degree of identity with those of Chromatium vinosum and of Alvinoconcha hessleri endosymbiont. Both T. ferrooxidans enzyme subunits contain all the conserved amino acids that are known to participate in the catalytic process or in holoenzyme assembly.}, }
@article {pmid1787328, year = {1991}, author = {O'Neill, SL}, title = {Cytoplasmic incompatibility in Drosophila populations: influence of assortative mating on symbiont distribution.}, journal = {Journal of invertebrate pathology}, volume = {58}, number = {3}, pages = {436-443}, doi = {10.1016/0022-2011(91)90190-2}, pmid = {1787328}, issn = {0022-2011}, mesh = {Animals ; *Crosses, Genetic ; Drosophila/genetics/*microbiology ; Drosophila melanogaster/genetics/*microbiology ; Female ; Male ; Rickettsiaceae/*physiology ; Symbiosis ; }, abstract = {Cytoplasmic incompatibility is known to occur between strains of both Drosophila simulans and D. melanogaster. Incompatibility is associated with the infection of Drosophila with microorganismal endosymbionts. This paper reports survey work conducted on strains of D. simulans and D. melanogaster from diverse geographical locations finding that infected populations are relatively rare and scattered in their distribution. The distribution of infected populations of D. simulans appears to be at odds with deterministic models predicting the rapid spread of the infection through uninfected populations. Examination of isofemale lines from four localities in California where populations appear to be polymorphic for the infection failed to find evidence for consistent assortative mating preferences between infected and uninfected populations that may explain the basis for the observed polymorphism.}, }
@article {pmid1720859, year = {1991}, author = {Maier, UG and Hofmann, CJ and Eschbach, S and Wolters, J and Igloi, GL}, title = {Demonstration of nucleomorph-encoded eukaryotic small subunit ribosomal RNA in cryptomonads.}, journal = {Molecular &amp; general genetics : MGG}, volume = {230}, number = {1-2}, pages = {155-160}, pmid = {1720859}, issn = {0026-8925}, mesh = {Animals ; Base Sequence ; Electrophoresis ; Eukaryota/*chemistry/genetics/ultrastructure ; Eukaryotic Cells/*chemistry ; Molecular Sequence Data ; Nucleic Acid Conformation ; Organelles/chemistry ; Phylogeny ; RNA ; RNA, Ribosomal/*analysis ; Symbiosis ; }, abstract = {In cryptomonads, unicellular phototrophic flagellates, the plastid(s) is (are) located in a special narrow compartment which is bordered by two membranes; it harbours neither mitochondria nor Golgi dictyosomes but comprises eukaryotic ribosomes and starch grains together with a small organelle called the nucleomorph. The nucleomorph contains DNA and is surrounded by a double membrane with pores. It is thought to be the vestigial nucleus of a phototrophic eukaryotic endosymbiont. Cryptomonads are therefore supposed to represent an intermediate state in the evolution of complex plastids from endosymbionts. We have succeeded in isolating pure nucleomorph fractions, and can thus provide, using pulsed field gel electrophoresis, polymerase chain reaction and sequence analysis, definitive proof for the eukaryotic nature of the symbiont and its phylogenetic origin.}, }
@article {pmid1917864, year = {1991}, author = {Munson, MA and Baumann, P and Clark, MA and Baumann, L and Moran, NA and Voegtlin, DJ and Campbell, BC}, title = {Evidence for the establishment of aphid-eubacterium endosymbiosis in an ancestor of four aphid families.}, journal = {Journal of bacteriology}, volume = {173}, number = {20}, pages = {6321-6324}, pmid = {1917864}, issn = {0021-9193}, mesh = {Animals ; Aphids/*microbiology ; Base Sequence ; Blotting, Southern ; Cloning, Molecular ; DNA, Bacterial/genetics ; DNA, Ribosomal/*genetics ; Gram-Negative Anaerobic Bacteria/classification/genetics ; Gram-Negative Bacteria/*genetics ; Gram-Negative Facultatively Anaerobic Rods/classification/genetics ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 16S/*genetics ; Restriction Mapping ; *Symbiosis ; }, abstract = {Aphids (superfamily Aphidoidea) contain eubacterial endosymbionts localized within specialized cells (mycetocytes). The endosymbionts are essential for the survival of the aphid hosts. Sequence analyses of the 16S rRNAs from endosymbionts of 11 aphid species from seven tribes and four families have indicated that the endosymbionts are monophyletic. Furthermore, phylogenetic relationships within the symbiont clade parallel the relationships of the corresponding aphid hosts. Our findings suggest that this endocytobiotic association was established in a common ancestor of the four aphid families with subsequent diversification into the present species of aphids and their endosymbionts.}, }
@article {pmid1685735, year = {1991}, author = {Kakeda, K and Ishikawa, H}, title = {Molecular chaperon produced by an intracellular symbiont.}, journal = {Journal of biochemistry}, volume = {110}, number = {4}, pages = {583-587}, doi = {10.1093/oxfordjournals.jbchem.a123623}, pmid = {1685735}, issn = {0021-924X}, mesh = {Adenosine Triphosphatases/metabolism ; Animals ; Aphids/*microbiology ; *Bacterial Physiological Phenomena ; Bacterial Proteins/metabolism ; Chaperonin 60 ; *Chaperonins ; Escherichia coli/metabolism ; Heat-Shock Proteins/metabolism ; Insect Hormones/*biosynthesis ; Macromolecular Substances ; Molecular Weight ; *Protein Biosynthesis ; Protein Conformation ; Proteins/isolation &amp; purification/metabolism ; Ribulose-Bisphosphate Carboxylase/metabolism ; Symbiosis ; }, abstract = {Symbionin, that is selectively produced by an intracellular symbiont harbored by the aphid bacteriocyte, is structurally homologous to the Escherichia coli groEL protein, a heat shock protein functioning as a molecular chaperon. It was shown that symbionin has ATPase activity and, in the presence of Mg-ATP, is converted into lower molecular mass species. Like the groEL protein, symbionin was able to reconstitute dimeric ribulose 1,5-bisphosphate carboxylase/oxygenase holoenzyme from its unfolded subunits in vitro, suggesting that this protein functions as a molecular chaperon in the endosymbiont. The groES-homologous protein did exist in the endosymbiont, but its amount was small relative to that of symbionin.}, }
@article {pmid1920151, year = {1991}, author = {Broers, CA and Stumm, CK and Vogels, GD}, title = {Axenic cultivation of the anaerobic free-living ciliate Trimyema compressum.}, journal = {The Journal of protozoology}, volume = {38}, number = {5}, pages = {507-511}, doi = {10.1111/j.1550-7408.1991.tb04825.x}, pmid = {1920151}, issn = {0022-3921}, mesh = {Anaerobiosis ; Animals ; Bacteria/growth &amp; development ; Ciliophora/enzymology/*growth &amp; development ; Culture Media ; Fluorescent Antibody Technique ; Germ-Free Life ; Hydrogenase/analysis ; Symbiosis ; }, abstract = {The strain N of Trimyema compressum, an anaerobic free-living ciliate, was cultivated axenically in a medium containing a buffered salt solution, yeast extract, trypticase, and glutathione. Dead bacteria were indispensable as food; a culture of the ciliate together with heat-killed Klebsiella pneumoniae has been established for more than one year. In the medium described, the ciliates grow to a higher cell density than in cultures with living bacteria as food. During the process of axenization, a nonmethanogenic bacterial endosymbiont was lost. In the microbodies of T. compressum, hydrogenase could be localized by the technique of indirect immunofluorescence.}, }
@article {pmid1920148, year = {1991}, author = {Faria e Silva, PM and Solé-Cava, AM and Soares, MJ and Motta, MC and Fiorini, JE and de Souza, W}, title = {Herpetomonas roitmani (Fiorini et al., 1989) n. comb.: a trypanosomatid with a bacterium-like endosymbiont in the cytoplasm.}, journal = {The Journal of protozoology}, volume = {38}, number = {5}, pages = {489-494}, doi = {10.1111/j.1550-7408.1991.tb04822.x}, pmid = {1920148}, issn = {0022-3921}, mesh = {Animals ; Bacteria/ultrastructure ; Crithidia/classification/enzymology/microbiology/ultrastructure ; Isoenzymes/analysis ; Phylogeny ; Symbiosis ; Trypanosomatina/*classification/enzymology/microbiology/ultrastructure ; }, abstract = {The trypanosomatid previously described as Crithidia roitmani is characterized here at the ultrastructural and biochemical levels. The data indicates that the parasite belongs to the Herpetomonas genus, and we therefore suggest the flagellate to be denominated as Herpetomonas roitmani n. comb. Cladistic analysis of isoenzyme data generated by eight different enzymes showed that the parasite presented a distinct banding pattern and could be grouped with some Herpetomonas spp., but not with Crithidia spp., used as reference strains. Accordingly, when the parasites were grown for longer periods in Roitman's defined medium, expontaneous differentiation from promastigotes to opisthomastigotes (typical of the Herpetomonas genus) occurred. Transmission electron microscopy revealed the presence of bacterium-like endosymbionts in the cytoplasm of all evolutive forms of the parasite. All morphological alterations characteristic of endosymbiont-bearing trypanosomatids could be observed.}, }
@article {pmid1908205, year = {1991}, author = {Gijzen, HJ and Broers, CA and Barughare, M and Stumm, CK}, title = {Methanogenic bacteria as endosymbionts of the ciliate Nyctotherus ovalis in the cockroach hindgut.}, journal = {Applied and environmental microbiology}, volume = {57}, number = {6}, pages = {1630-1634}, pmid = {1908205}, issn = {0099-2240}, mesh = {Animals ; Ciliophora/*microbiology ; Euryarchaeota/*growth &amp; development ; Feeding Behavior ; Methane/metabolism ; Metronidazole/pharmacology ; Microscopy, Electron ; Periplaneta/drug effects/growth &amp; development/*microbiology/ultrastructure ; *Symbiosis ; }, abstract = {Production of methane in the hindgut of the cockroach Periplaneta americana was found to vary, depending on the feeding regimen. Methane production was positively correlated with the numbers of the ciliate Nyctotherus ovalis living in the cockroach hindgut. Defaunation of the cockroaches by means of low concentrations of metronidazole (Flagyl) resulted in a quick drop of methane production. Addition of the methanogenic substrates acetate and formate to isolated hindguts stimulated methane production. Inside the ciliate cells, autofluorescing bacteria could be demonstrated which were presumed to be methanogens. Electron microscopy revealed that the bacteria resembled Methanobrevibacter and that they were closely associated with organelles which contained infolded membranes and which were presumably hydrogenosomes.}, }
@article {pmid1764529, year = {1991}, author = {Smooker, PM and Schmidt, J and Subramanian, AR}, title = {The nuclear:organelle distribution of chloroplast ribosomal proteins genes. Features of a cDNA clone encoding the cytoplasmic precursor of L11.}, journal = {Biochimie}, volume = {73}, number = {6}, pages = {845-851}, doi = {10.1016/0300-9084(91)90064-8}, pmid = {1764529}, issn = {0300-9084}, mesh = {Amino Acid Sequence ; Bacteria/genetics ; *Biological Evolution ; Cell Nucleus/*chemistry ; Chloroplasts/*chemistry ; Molecular Sequence Data ; Nucleic Acid Conformation ; Plants/*genetics ; Protein Precursors/genetics ; Protein Sorting Signals/chemistry ; Ribosomal Proteins/drug effects/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {The majority of chloroplast ribosomal proteins are encoded in the nuclear genome. In order to characterize these proteins through their mRNA, we have previously constructed a spinach cDNA expression library and raised antisera to several spinach chloroplast ribosomal proteins. Here we describe the immuno isolation of cDNA clones encoding protein L11 and its chloroplast-targeting presequence. The cytoplasmic precursor form of L11 is 224 amino acid residues long (Mr 23,662); the mature L11 and the transit sequence are predicted to be of approximately 159 and approximately 65 residues, respectively. The predicted chloroplast L11 is significantly longer than the E coli L11, but similar (in size) to archaebacterial and yeast cytoplasmic L11. In sequence it is closer to E coli L11 (54% identity) than to the archaebacterial (32%) or yeast (23%) proteins. These results and the conservation of the contexts of the 3 methyl modified residues found in E coli L11 are discussed in the light of the endosymbiont theory and nuclear relocation of the rp/KAJL gene cluster.}, }
@article {pmid1709451, year = {1991}, author = {Amann, R and Springer, N and Ludwig, W and Görtz, HD and Schleifer, KH}, title = {Identification in situ and phylogeny of uncultured bacterial endosymbionts.}, journal = {Nature}, volume = {351}, number = {6322}, pages = {161-164}, doi = {10.1038/351161a0}, pmid = {1709451}, issn = {0028-0836}, mesh = {Animals ; Base Sequence ; Cloning, Molecular ; DNA, Bacterial/genetics/*isolation &amp; purification ; Gram-Negative Bacteria/classification/genetics/*isolation &amp; purification/physiology ; Molecular Sequence Data ; Oligonucleotide Probes ; Paramecium/*microbiology ; Phylogeny ; Polymerase Chain Reaction ; RNA Probes ; RNA, Bacterial/genetics ; RNA, Ribosomal, 16S/genetics ; *Symbiosis ; }, abstract = {The use of Koch's technique to isolate bacteria in pure cultures has enabled thousands of bacterial species to be characterized. But for the many microorganisms that have never been cultivated, DNA amplification in vitro using the polymerase chain reaction is now making their genes accessible. Here we use this technique to study bacteria of the genus Holospora, which live in ciliates and whose phylogenetic relationship has remained unknown because they are impossible to cultivate. Species of Holospora are highly infectious and live in the nuclei of their specific host cells: H. elegans and H. undulata infect micronuclei of Paramecium caudatum, whereas H. obtusa infects the macronucleus in other strains of the same host species; Holospora species have a common developmental cycle. We have amplified, cloned and sequenced gene fragments encoding ribosomal RNA of H. obtusa. The phylogenetic position of H. obtusa in the alpha group of Proteobacteria was determined by 16S rRNA sequence analysis. The sequences were then used to design species- as well as genus-specific rRNA hybridization probes, which enabled us to detect and differentiate individual cells of the endosymbionts in situ. The large amount of rRNA in the cells indicates a high physiological activity of the endosymbionts in the host nuclei.}, }
@article {pmid1830906, year = {1991}, author = {Jacobs, HT}, title = {Structural similarities between a mitochondrially encoded polypeptide and a family of prokaryotic respiratory toxins involved in plasmid maintenance suggest a novel mechanism for the evolutionary maintenance of mitochondrial DNA.}, journal = {Journal of molecular evolution}, volume = {32}, number = {4}, pages = {333-339}, pmid = {1830906}, issn = {0022-2844}, mesh = {*Biological Evolution ; DNA, Mitochondrial/*genetics ; Molecular Structure ; Peptides/chemistry/genetics ; Plasmids ; Prokaryotic Cells ; Proton-Translocating ATPases/genetics ; Sequence Homology, Nucleic Acid ; Toxins, Biological/chemistry/genetics ; }, abstract = {Subunit 8 of mitochondrial ATP synthase (A8), a mitochondrially encoded polypeptide, has no known homologue in any prokaryotic or plastid ATP synthase, suggesting that it has been recruited to its present role in the enzyme from an extraneous source. The polypeptide is poorly conserved at the primary sequence level, but shows a well-conserved hydropathy profile. The hydropathy profiles of A8 from diverse taxa were compared with those of the hok family of prokaryotic respiratory toxins, some of whose members are involved in plasmid maintenance, through postsegregational killing of cells that lose the plasmid at cell division. Such comparisons revealed a highly significant degree of similarity, suggesting a functional relationship. Based on these findings, it is proposed that A8 evolved from a hok-like protein, whose original role was the maintenance of an extrachromosomal replicon in the endosymbiont ancestor of mitochondria. An aggressive mechanism for the evolutionary maintenance of mitochondrial DNA overcomes many of the failings of traditional explanations for its retention as a separate genome.}, }
@article {pmid2005963, year = {1991}, author = {Douglas, SE and Murphy, CA and Spencer, DF and Gray, MW}, title = {Cryptomonad algae are evolutionary chimaeras of two phylogenetically distinct unicellular eukaryotes.}, journal = {Nature}, volume = {350}, number = {6314}, pages = {148-151}, doi = {10.1038/350148a0}, pmid = {2005963}, issn = {0028-0836}, mesh = {Animals ; Base Sequence ; Chimera ; DNA, Ribosomal/*genetics ; Electrophoresis, Agar Gel ; Eukaryota/*genetics ; Eukaryotic Cells ; Molecular Sequence Data ; Phylogeny ; RNA, Ribosomal, 18S/*genetics ; Repetitive Sequences, Nucleic Acid ; Sequence Alignment ; Symbiosis ; Transcription, Genetic ; }, abstract = {Although it is widely accepted that the plastids of plants and algae originated as endosymbionts, the details of this evolutionary process are unclear. It has been proposed that in organisms whose plastids are surrounded by more than two membranes, the endosymbiont was a eukaryotic alga rather than a photosynthetic prokaryote. The DNA-containing nucleomorph of cryptomonad algae appears to be the vestigial nucleus of such an algal endosymbiont. Eukaryotic-type ribosomal RNA sequences have been localized to a nucleolus-like structure in the nucleomorph. In support of the hypothesis that cryptomonads are evolutionary chimaeras of two distinct eukaryotic cells, we show here that Cryptomonas phi contains two phylogenetically separate, nuclear-type small-subunit rRNA genes, both of which are transcriptionally active. We incorporate our rRNA sequence data into phylogenetic trees, from which we infer the evolutionary ancestry of the host and symbiont components of Cryptomonas phi. Such trees do not support the thesis that chromophyte algae evolved directly from a cryptomonad-like ancestor.}, }
@article {pmid2004348, year = {1991}, author = {Zierdt, CH}, title = {Blastocystis hominis--past and future.}, journal = {Clinical microbiology reviews}, volume = {4}, number = {1}, pages = {61-79}, pmid = {2004348}, issn = {0893-8512}, mesh = {Animals ; Eukaryota/*classification/isolation &amp; purification/ultrastructure ; Humans ; Intestinal Diseases, Parasitic/drug therapy/*parasitology ; Mitochondria/ultrastructure ; Protozoan Infections/drug therapy/*parasitology ; }, abstract = {The history of B. hominis is unique. Few infectious agents have provoked the many misconceptions that plague this enigmatic parasitic ameba. Conflicting descriptions of its nature and pathogenesis have continued throughout the 20th century. As seen by the greatly expanded number of reports in recent years, B. hominis is now a major subject of study, particularly for evidence of disease causation. Physicians are treating patients with intestinal disease caused by B. hominis. Many mild cases resolve in about 3 days without treatment, but others are acute and chronic disease is common. As with E. histolytica, the carrier state is often seen without symptoms. Treatment is usually with metronidazole, but emetine (for refractory infections), trimethoprim-sulfamethoxazole, and pentamidine are also effective. In fecal samples, this complex protozoan appears in a variety of cell forms which makes microscopic diagnosis difficult. As yet, no specific fluorescent-antibody test is available for diagnosis. A culture method to demonstrate the more easily recognized CB form is available, but probably not feasible for most diagnostic laboratories. The common cell forms are the CB form, the granular (mitochondria) form, and the ameba form. The unexpected size range of these forms in clinical material, from yeast size (ca. 7 microns) to giant cells of 20 to 40 microns, makes diagnosis difficult Pseudopodia may be demonstrated by the ameba form in heated microscope stage culture chambers. The anaerobic B. hominis has no cyst form. Its mitochondria are uniquely anaerobic and have no cytochrome protein or oxidative mitochondrial enzymes. Because of its many cell forms and anaerobic mitochondria, B. hominis is an organism of great interest for morphologic and biochemical study. Reproduction is asexual, usually by binary fission. Shizogony occurs in cultured cells. The CB appears to be an organelle whose specific purpose is for reproduction by shizogony. From 2 to 30 progeny are derived from schizogony. The ameba form reproduces by plasmotomy; it has no CB. The pathology of B. hominis infections has been studied in gnotobiotic guinea pigs in which inflammation of the intestinal mucosa and invasion of the superficial layers were seen. Only limited studies of human pathology are available. Those who have studied mucosal histopathology report inflammation and cellular changes that resolve after treatment. More study in this area is strongly indicated (32, 44, 57, 62, 67, 75). Ultrastructural details of B. hominis major forms, except for the schizont, are complete. The organism has no cell wall. The concentric CB takes up as much as 95% of the cell. The major organelles, which include multiple nuclei, Golgi apparatus, mitochondria, endoplasmic reticulum, fat, and other inclusions, are confined in two or four opposed pods in a thin band of peripheral cytoplasm between the spherical entire plasma membrane and the CB membrane. The pods buldge the CB membrane inward. There is evidence of a bacteroid endosymbiont. Education about B. hominis is needed. Entry of recent findings into new textbooks is imperative for its understanding among medical practitioners. Laboratory workers need to be aware of it for many reasons. The College of American Pathologists includes B. hominis in its proficiency testing samples and requires that it be reported from clinical samples.}, }
@article {pmid1912387, year = {1991}, author = {Choi, EY and Ahn, GS and Jeon, KW}, title = {Elevated levels of stress proteins associated with bacterial symbiosis in Amoeba proteus and soybean root nodule cells.}, journal = {Bio Systems}, volume = {25}, number = {3}, pages = {205-212}, doi = {10.1016/0303-2647(91)90006-7}, pmid = {1912387}, issn = {0303-2647}, mesh = {Amoeba/metabolism/microbiology ; Animals ; Bacterial Proteins/metabolism ; Chaperonins ; Cross Reactions ; Escherichia coli Proteins ; Heat-Shock Proteins/chemistry/immunology/*metabolism ; Molecular Weight ; Plants/metabolism ; Rhizobiaceae/metabolism ; Symbiosis ; }, abstract = {Obligatory bacterial endosymbionts of Amoeba proteus and symbiotic Bradyrhizobium japonicum bacteroids in soybean-root nodules contained large amounts of 67-kDa and 65-kDa proteins, respectively, antigenically related to groEL of E. coli and the 58-kDa heat-shock protein of Tetrahymena. Monoclonal antibodies against the 67-kDa protein recognized groEL analogs from several different organisms. The quantity of the stress protein in symbiotic B. japonicum bacteroids was augmented seven times that in the free-living counterparts. The increase in these proteins in endosymbionts, as determined by immunoblot techniques, indicated that intracellular symbiosis is a stress condition even when the symbiotic relationship is considered to be mutually beneficial. Mitochondria and chloroplasts may also be under a stressed condition like endosymbionts in view of the presence of heat-shock proteins in these cell organelles.}, }
@article {pmid2234083, year = {1990}, author = {O'Neill, SL and Karr, TL}, title = {Bidirectional incompatibility between conspecific populations of Drosophila simulans.}, journal = {Nature}, volume = {348}, number = {6297}, pages = {178-180}, doi = {10.1038/348178a0}, pmid = {2234083}, issn = {0028-0836}, mesh = {Animals ; Drosophila/embryology/*microbiology ; Female ; Infertility ; Male ; Ovum/microbiology ; Rickettsia/*pathogenicity ; Spermatozoa/microbiology ; Tetracycline/therapeutic use ; }, abstract = {Cytoplasmic incompatibility (CI) describes the phenomenon whereby eggs fertilized by sperm from insects infected with a rickettsial endosymbiont fail to hatch. Unidirectional CI between conspecific populations of insects is a well documented phenomenon. Bidirectional CI has, however, only been described in mosquito populations, and recently between closely related species of parasitic wasps, where it is of interest as both an unusual form of reproductive isolation and as a potential means of insect population suppression. Here we report on the first known example of bidirectional CI between conspecific populations of Drosophila simulans. Further, we show that defects as early as the first cleavage division are associated with CI. This observation suggests that the cellular basis of CI involves disruption of processes before or during zygote formation and that CI arises from defects in the structure and/or function of the sperm during fertilization.}, }
@article {pmid2280390, year = {1990}, author = {Beard, CB and Butler, JF and Hall, DW}, title = {Prevalence and biology of endosymbionts of fleas (Siphonaptera: Pulicidae) from dogs and cats in Alachua County, Florida.}, journal = {Journal of medical entomology}, volume = {27}, number = {6}, pages = {1050-1061}, doi = {10.1093/jmedent/27.6.1050}, pmid = {2280390}, issn = {0022-2585}, support = {A1-08614//PHS HHS/United States ; }, mesh = {Animals ; Cat Diseases/*parasitology ; Cats ; Dog Diseases/*parasitology ; Dogs ; Ectoparasitic Infestations/parasitology/*veterinary ; Florida ; Pest Control, Biological ; Siphonaptera/microbiology/*parasitology ; }, abstract = {A study was conducted to determine the prevalence and biology of endosymbionts in local populations of fleas collected from dogs and cats in Alachua Co., Florida. Four hundred three Ctenocephalides felis (Bouché), 194 Pulex simulans Baker, and 44 Echidnophaga gallinacea (Westwood) were examined. Fleas were collected from 52 dogs and 51 cats. From 1 to 20 fleas were dissected from each host. A variety of microorganisms and metazoa was observed, including a baculovirus, gram-negative bacteria, rickettsia-like organisms, amoebae, trypanosomatid flagellates, cephaline gregarines, and microsporidia. Microfilariae of the dog heartworm, Dirofilaria immitis, entomophilic nematodes, and metacestodes of the tapeworm Dipylidium caninum were also observed.}, }
@article {pmid2247456, year = {1990}, author = {Stein, JL and Haygood, M and Felbeck, H}, title = {Nucleotide sequence and expression of a deep-sea ribulose-1,5-bisphosphate carboxylase gene cloned from a chemoautotrophic bacterial endosymbiont.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {87}, number = {22}, pages = {8850-8854}, pmid = {2247456}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Animals ; Bacteria/*genetics ; Base Sequence ; Cloning, Molecular ; Gene Expression ; *Genes, Bacterial ; Molecular Sequence Data ; Mollusca/microbiology ; Oligonucleotides ; Polymerase Chain Reaction ; Recombinant Proteins ; Restriction Mapping ; Ribulose-Bisphosphate Carboxylase/*genetics ; Symbiosis ; }, abstract = {The gene coding for ribulose-1,5-bisphosphate carboxylase [RuBisCO; 3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39] was cloned from a sulfur-oxidizing chemoautotrophic bacterium that resides as an endosymbiont within the gill tissues of Alvinoconcha hessleri, a gastropod inhabiting deep-sea hydrothermal vents. Nucleotide sequence analysis of the cloned fragment demonstrated that the genes encoding the large (RbcL) and small (RbcS) subunits of the symbiont RuBisCO were organized similarly to the RuBisCO operons of free-living photo- and chemoautotrophic prokaryotes. The symbiont rbcL gene shared the highest degree of nucleotide sequence identity with the cyanobacterium Anabaena (69%) while the rbcS nucleotide sequence shared 61% identity with that of the green alga Chlamydomonas reinhardtii. Comparison with a 153-nucleotide partial rbcL sequence from a symbiont of the bivalve Solemya reidi indicated that the two symbiont sequences shared 85% sequence identity at the nucleotide level and 93% at the amino acid level, suggesting a relatively recent common origin. Escherichia coli transformed with a plasmid carrying the RuBisCO operon of the gastropod symbiont in the proper orientation for transcription from the plasmid lac promoter expressed catalytically active RuBisCO. The presence of enzyme activity suggests the proper assembly of the subunits of this deep-sea RuBisCO into the holoenzyme.}, }
@article {pmid2271612, year = {1990}, author = {Smooker, PM and Choli, T and Subramanian, AR}, title = {Ribosomal protein L35: identification in spinach chloroplasts and isolation of a cDNA clone encoding its cytoplasmic precursor.}, journal = {Biochemistry}, volume = {29}, number = {41}, pages = {9733-9736}, doi = {10.1021/bi00493a032}, pmid = {2271612}, issn = {0006-2960}, mesh = {Amino Acid Sequence ; Base Sequence ; Chloroplasts/*metabolism ; Cloning, Molecular ; DNA/genetics/isolation &amp; purification ; Escherichia coli/genetics ; *Escherichia coli Proteins ; Molecular Sequence Data ; Plants/*genetics/metabolism ; Protein Precursors/*genetics ; Ribosomal Proteins/*genetics/isolation &amp; purification ; Ribosomes/metabolism ; Sequence Homology, Nucleic Acid ; }, abstract = {We describe the isolation of spinach chloroplast ribosomal protein L35 and characterization of a cDNA clone encoding its cytoplasmic precursor. This protein was only recently identified in ribosomes, but the sequences of four L35 genes have now been reported and confirm its presence in eubacteria, chloroplasts, and cyanelles. Using N-terminal sequence data, oligonucleotides were designed and a cDNA library was screened. The nucleotide sequence of the cDNA clones shows that the spinach L35 protein is encoded as a precursor of 159 residues, comprising a mature protein of 73 residues and a transit peptide of 86 residues. The cleavage site for forming the mature protein is deduced to be Thr-Val-Phe-Ala decreases Ala-Lys-Gly-Tyr. The L35 protein in the photosynthetic organelle of the protozoan Cyanophora paradoxa is encoded in the organelle DNA [Bryant &amp; Stirewalt (1990) FEBS Lett. 259, 273-280]. The corresponding gene has not been found in the chloroplast DNA of a lower plant (liverwort) and two higher plants. Our results demonstrate that the L35 protein in a higher plant (spinach) is encoded in the nucleus. This finding, in light of the endosymbiont hypothesis, suggests an organelle to nucleus transfer of the L35 gene at the evolutionary beginnings of land plants.}, }
@article {pmid2145157, year = {1990}, author = {Mahlke, K and Pfanner, N and Martin, J and Horwich, AL and Hartl, FU and Neupert, W}, title = {Sorting pathways of mitochondrial inner membrane proteins.}, journal = {European journal of biochemistry}, volume = {192}, number = {2}, pages = {551-555}, doi = {10.1111/j.1432-1033.1990.tb19260.x}, pmid = {2145157}, issn = {0014-2956}, mesh = {Base Sequence ; Biological Evolution ; DNA, Fungal/genetics/isolation &amp; purification ; Heat-Shock Proteins/metabolism ; Intracellular Membranes/*enzymology ; Mitochondrial ADP, ATP Translocases/genetics/metabolism ; Molecular Sequence Data ; Neurospora crassa/enzymology/*genetics ; Oligonucleotide Probes ; *Protein Processing, Post-Translational ; Proton-Translocating ATPases/*genetics/metabolism ; Recombinant Fusion Proteins/metabolism ; Submitochondrial Particles/*enzymology ; }, abstract = {Two distinct pathways of sorting and assembly of nuclear-encoded mitochondrial inner membrane proteins are described. In the first pathway, precursor proteins that carry amino-terminal targeting signals are initially translocated via contact sites between both mitochondrial membranes into the mitochondrial matrix. They become proteolytically processed, interact with the 60-kDa heat-shock protein hsp60 in the matrix and are retranslocated to the inner membrane. The sorting of subunit 9 of Neurospora crassa F0-ATPase has been studied as an example. F0 subunit 9 belongs to that class of nuclear-encoded mitochondrial proteins which are evolutionarily derived from a prokaryotic ancestor according to the endosymbiont hypothesis. We suggest that after import into mitochondria, these proteins follow the ancestral sorting and assembly pathways established in prokaryotes (conservative sorting). On the other hand, ADP/ATP carrier was found not to require interaction with hsp60 for import and assembly. This agrees with previous findings that the ADP/ATP carrier possesses non-amino-terminal targeting signals and uses a different import receptor to other mitochondrial precursor proteins. It is proposed that the ADP/ATP carrier represents a class of mitochondrial inner membrane proteins which do not have a prokaryotic equivalent and thus appear to follow a non-conservative sorting pathway.}, }
@article {pmid2401287, year = {1990}, author = {Juretić, N and Mattes, U and Ziak, M and Christen, P and Jaussi, R}, title = {Structure of the genes of two homologous intracellularly heterotopic isoenzymes. Cytosolic and mitochondrial aspartate aminotransferase of chicken.}, journal = {European journal of biochemistry}, volume = {192}, number = {1}, pages = {119-126}, doi = {10.1111/j.1432-1033.1990.tb19204.x}, pmid = {2401287}, issn = {0014-2956}, mesh = {Amino Acid Sequence ; Animals ; Aspartate Aminotransferases/*genetics ; Base Sequence ; Biological Evolution ; Body Fluids/*enzymology ; Chickens ; Chromosome Mapping ; Cloning, Molecular ; Cytosol/enzymology ; Exons ; Intracellular Fluid/*enzymology ; Introns ; Mitochondria/enzymology ; Molecular Sequence Data ; Protein Conformation ; Restriction Mapping ; Sequence Homology, Nucleic Acid ; }, abstract = {The genes of mitochondrial and cytosolic aspartate aminotransferase of chicken were cloned and sequenced. In both genes nine exons encode the mature enzyme. The additional exon for the N-terminal presequence that directs mitochondrial aspartate aminotransferase into the mitochondria is separated by the largest intron from the rest of the gene. A comparison of the two genes of chicken with the aspartate aminotransferase genes of mouse [Tsuzuki, T., Obaru, K., Setoyama, C. &amp; Shimada, K. (1987) J. Mol. Biol. 198, 21-31; Obaru, K., Tsuzuki, T., Setoyama, C. &amp; Shimada, K. (1988) J. Mol. Biol. 200, 13-22] reveals closely similar structures: in the gene of both the mitochondrial and the cytosolic isoenzyme all but one intron positions are conserved in the two species and five introns out of nine are placed at the same positions in all four genes indicating that the introns were in place before the genes of the two isoenzymes diverged. The variant consensus sequence (T/C)11 T(C/T)AG at the 3' splice site of the introns of the genes for nuclear-encoded mitochondrial proteins, which had been deduced from a total of 34 introns [Juretić, N., Jaussi, R., Mattes, U. &amp; Christen, P. (1987) Nucleic Acids Res. 15, 10,083-10,086], was confirmed by including an additional 22 introns into the comparison. The position -4 at the 3' splice site is occupied by base T in 43% of the total 56 introns and appears to be subject to a special evolutionary constraint in this particular group of genes. The following course of evolution of the aspartate aminotransferase genes is proposed. Originating from a common ancestor, the genes of the two isoenzymes intermediarily evolved in separate lineages, i.e. the ancestor eukaryotic and ancestor endosymbiontic cells. When endosymbiosis was established, part of the endosymbiontic genome, including the aspartate aminotransferase gene, was transferred to the nucleus. This process probably led to the conservation of certain splicing factors specific for nuclear-encoded mitochondrial proteins. The presequence for the mitochondrial isoenzyme was acquired by DNA rearrangement. In the eukaryotic lineage, the mitochondrial isoenzyme evolved more slowly than its cytosolic counterpart.}, }
@article {pmid2119815, year = {1990}, author = {Sibold, C and Subramanian, AR}, title = {Cloning and characterization of the genes for ribosomal proteins L10 and L12 from Synechocystis Sp. PCC 6803: comparison of gene clustering pattern and protein sequence homology between cyanobacteria and chloroplasts.}, journal = {Biochimica et biophysica acta}, volume = {1050}, number = {1-3}, pages = {61-68}, doi = {10.1016/0167-4781(90)90142-o}, pmid = {2119815}, issn = {0006-3002}, mesh = {Amino Acid Sequence ; Base Sequence ; Chloroplasts/*metabolism ; Cloning, Molecular ; Codon/genetics ; Cyanobacteria/*genetics ; DNA/genetics/isolation &amp; purification ; Molecular Sequence Data ; *Multigene Family ; Plants/*genetics ; Restriction Mapping ; Ribosomal Protein L10 ; Ribosomal Proteins/*genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {The endosymbiont theory proposes that chloroplasts have originated from ancestral cyanobacteria through a process of engulfment and subsequent symbiotic adaptation. The molecular data for testing this theory have mainly been the nucleotide sequence of rRNAs and of photosystem component genes. In order to provide additional data in this area, we have isolated genomic clones of Synechocystis DNA containing the ribosomal protein gene cluster rplJL. The nucleotide sequence of this cluster and flanking regions was determined and the derived amino acid sequences were compared to the available homologous sequences from other eubacteria and chloroplasts. In Escherichia coli these two genes are part of a larger cluster, i.e., rplKAJL-rpoBC. In Synechocystis, the genes for the RNA polymerase subunit (rpoBC) are shown to be widely separated from the r-protein genes. The Synechocystis gene arrangement is similar to that in the chloroplast system, where the rpoBC1C2 and rplKAJL clusters are separated and located in two cell compartments, the chloroplast and the nucleus, respectively.}, }
@article {pmid2376575, year = {1990}, author = {Johnson, CH and Kruft, V and Subramanian, AR}, title = {Identification of a plastid-specific ribosomal protein in the 30 S subunit of chloroplast ribosomes and isolation of the cDNA clone encoding its cytoplasmic precursor.}, journal = {The Journal of biological chemistry}, volume = {265}, number = {22}, pages = {12790-12795}, pmid = {2376575}, issn = {0021-9258}, mesh = {Amino Acid Sequence ; Chloroplasts/*metabolism ; Cloning, Molecular ; DNA/genetics ; Gene Library ; Molecular Sequence Data ; Molecular Weight ; Peptide Fragments/isolation &amp; purification ; Peptide Mapping ; Plants/*genetics/metabolism ; Restriction Mapping ; Ribosomal Proteins/isolation &amp; purification/*metabolism ; Ribosomes/*metabolism ; }, abstract = {We describe the isolation and characterization of a chloroplast ribosomal protein and a clone of its cDNA. This protein has no homology to any Escherichia coli ribosomal protein or to any known proteins. Due to this novel finding we propose it be called PSrp-1, i.e. a plastid-specific ribosomal protein. The precursor form of PSrp-1, deduced from the cDNA sequence, is 302-amino acid residues long. The mature PSrp-1, identified by amino-terminal sequencing, is a protein of 236 residues. The NH2-terminal 66 amino acids form the transit peptide that targets PSrp-1 into the chloroplast. We show that PSrp-1 is a protein of the chloroplast 30 S ribosomal subunit by Western blotting and sequencing the excised protein after two-dimensional gel electrophoresis. The possible evolutionary origin of PSrp-1 from the nucleated host cell of the endosymbiont theory is discussed.}, }
@article {pmid2200721, year = {1990}, author = {Hennecke, H}, title = {Nitrogen fixation genes involved in the Bradyrhizobium japonicum-soybean symbiosis.}, journal = {FEBS letters}, volume = {268}, number = {2}, pages = {422-426}, doi = {10.1016/0014-5793(90)81297-2}, pmid = {2200721}, issn = {0014-5793}, mesh = {Amino Acid Sequence ; Gene Expression Regulation, Bacterial ; *Genes, Bacterial ; Molecular Sequence Data ; *Multigene Family ; Nitrogen Fixation/*genetics ; Rhizobiaceae/*genetics ; Sequence Homology, Nucleic Acid ; Soybeans/*microbiology ; Symbiosis ; }, abstract = {The symbiotic nitrogen fixation genes (nif, fix) of Bradyrhizobium japonicum, the root nodule endosymbiont of soybean, are organized in at least two separate chromosomal gene clusters. These genes code for proteins of the nitrogenase complex, for proteins involved in their assembly with cofactors and for putative electron transport functions. One gene, nifA, codes for a transcriptional regulatory protein that plays a central role in the control of expression of the other genes in response to the cellular oxygen status. Only at low partial pressures of O2 will the target promoters be activated by NifA.}, }
@article {pmid2165219, year = {1990}, author = {Thorsness, PE and Fox, TD}, title = {Escape of DNA from mitochondria to the nucleus in Saccharomyces cerevisiae.}, journal = {Nature}, volume = {346}, number = {6282}, pages = {376-379}, doi = {10.1038/346376a0}, pmid = {2165219}, issn = {0028-0836}, mesh = {Cell Nucleus/*metabolism ; DNA, Fungal/genetics/*metabolism ; DNA, Mitochondrial/genetics/*metabolism ; Electron Transport Complex IV/genetics ; Genes, Fungal ; Genotype ; Mitochondria/*metabolism ; Plasmids ; Saccharomyces cerevisiae/*genetics/growth &amp; development/metabolism ; Temperature ; }, abstract = {The migration of genetic information from ancestral prokaryotic endosymbionts into eukaryotic nuclei is thought to have had an important role in the evolution of mitochondria and chloroplasts. Here we describe an assay for the detection of movement of DNA between mitochondria and the nucleus in yeast. Because recombinant plasmid DNA replicates after transformation into mitochondria of yeast strains lacking endogenous mitochondrial DNA we were able to propagate the nuclear genetic marker URA3 in mitochondria. As expected, the wild-type URA3 gene in mitochondria failed to complement the uracil auxotrophy (Ura-) caused by a nuclear ura3 mutation. But selection of Ura+ prototrophs from a Ura- strain carrying URA3 on a plasmid in its mitochondria enabled us to detect plasmid movement to the nucleus. Conversely, as the plasmid used also contained the mitochondrial gene COX2 required for respiratory growth, we were able to set up corresponding selections to detect migration of DNA from the nucleus to the mitochondria. Our results show that, in yeast, DNA escapes from mitochondria and appears in the nucleus at a surprisingly high frequency (approximately 2 x 10(-5) per cell per generation). But the rate at which DNA makes the journey in the opposite direction--nucleus to mitochondria--is apparently at least 100,000 times less.}, }
@article {pmid2320582, year = {1990}, author = {Göttfert, M and Grob, P and Hennecke, H}, title = {Proposed regulatory pathway encoded by the nodV and nodW genes, determinants of host specificity in Bradyrhizobium japonicum.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {87}, number = {7}, pages = {2680-2684}, pmid = {2320582}, issn = {0027-8424}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics ; Base Sequence ; Cloning, Molecular ; *Genes, Bacterial ; *Genes, Regulator ; Kinetics ; Molecular Sequence Data ; Mutation ; *Phosphotransferases ; Plants/microbiology ; Restriction Mapping ; Rhizobiaceae/*genetics ; Sequence Homology, Nucleic Acid ; *Transcription Factors ; }, abstract = {Bradyrhizobium japonicum is the root nodule endosymbiont of soybean (Glycine max), mung bean (Vigna radiata), cowpea (Vigna unguiculata), and Siratro (Macroptilium atropurpureum). We report the characteristics of a nodulation-gene region of B. japonicum that contributes only marginally to the bacterium's ability to nodulate soybean but is essential for the nodulation of the three alternative hosts. This DNA region consists of two open reading frames designated nodV and nodW. The predicted amino acid sequences of the NodV and NodW proteins suggest that they are members of the family of two-component regulatory systems, which supports the hypothesis that NodV responds to an environmental stimulus and, after signal transduction, NodW may be required to positively regulate the transcription of one or several unknown genes involved in the nodulation process. It seems likely that all host plants produce the necessary signal, whereas host specificity may be brought about by the product(s) of the gene(s) activated by NodW.}, }
@article {pmid2314461, year = {1990}, author = {Baldauf, SL and Palmer, JD}, title = {Evolutionary transfer of the chloroplast tufA gene to the nucleus.}, journal = {Nature}, volume = {344}, number = {6263}, pages = {262-265}, doi = {10.1038/344262a0}, pmid = {2314461}, issn = {0028-0836}, mesh = {Amino Acid Sequence ; Base Sequence ; *Biological Evolution ; Cell Nucleus/*metabolism ; Chlorophyta/genetics ; Chloroplasts/*metabolism ; DNA/*genetics ; Molecular Sequence Data ; Neurospora/genetics ; Nucleic Acid Hybridization ; Peptide Elongation Factor Tu/*genetics ; Plants/genetics ; Sequence Homology, Nucleic Acid ; }, abstract = {Evolutionary gene transfer is a basic corollary of the now widely accepted endosymbiotic theory, which proposes that mitochondria and chloroplasts originated from once free-living eubacteria. The small organellar chromosomes are remnants of larger bacterial genomes, with most endosymbiont genes having been either transferred to the nucleus soon after endosymbiosis or lost entirely, with some being functionally replaced by pre-existing nuclear genes. Several lines of evidence indicate that relocation of some organelle genes could have been more recent. These include the abundance of non-functional organelle sequences of recent origin in nuclear DNA, successful artificial transfer of functional organelle genes to the nucleus, and several examples of recently lost organelle genes, although none of these is known to have been replaced by a nuclear homologue that is clearly of organellar ancestry. We present gene sequence and molecular phylogenetic evidence for the transfer of the chloroplast tufA gene to the nucleus in the green algal ancestor of land plants.}, }
@article {pmid2406905, year = {1990}, author = {Hartl, FU and Neupert, W}, title = {Protein sorting to mitochondria: evolutionary conservations of folding and assembly.}, journal = {Science (New York, N.Y.)}, volume = {247}, number = {4945}, pages = {930-938}, doi = {10.1126/science.2406905}, pmid = {2406905}, issn = {0036-8075}, mesh = {Amino Acid Sequence ; *Biological Evolution ; Biological Transport, Active ; Cytosol/metabolism ; Heat-Shock Proteins/metabolism ; Intracellular Membranes/metabolism ; Mitochondria/*metabolism ; Models, Biological ; Molecular Sequence Data ; Peptide Hydrolases/metabolism ; Protein Conformation ; Protein Precursors/metabolism ; Proteins/*metabolism ; }, abstract = {According to the endosymbiont hypothesis, mitochondria have lost the autonomy of their prokaryotic ancestors. They have to import most of their proteins from the cytosol because the mitochondrial genome codes for only a small percentage of the polypeptides that reside in the organelle. Recent findings show that the sorting of proteins into the mitochondrial subcompartments and their folding and assembly follow principles already developed in prokaryotes. The components involved may have structural and functional equivalents in bacteria.}, }
@article {pmid2406240, year = {1990}, author = {Gantt, JS and Thompson, MD}, title = {Plant cytosolic ribosomal protein S11 and chloroplast ribosomal protein CS17. Their primary structures and evolutionary relationships.}, journal = {The Journal of biological chemistry}, volume = {265}, number = {5}, pages = {2763-2767}, pmid = {2406240}, issn = {0021-9258}, support = {GM38769/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; *Arabidopsis Proteins ; Base Sequence ; *Biological Evolution ; Chloroplasts/metabolism ; Cloning, Molecular ; Cytosol/metabolism ; DNA/genetics/isolation &amp; purification ; Escherichia coli/genetics ; Fabaceae/genetics ; Genes ; Molecular Sequence Data ; Plants/*genetics ; Plants, Medicinal ; Ribosomal Proteins/*genetics ; Sequence Homology, Nucleic Acid ; Soybeans/genetics ; }, abstract = {We have isolated cDNA clones specific for Arabidopsis thaliana cytosolic ribosomal protein S11 and plastid ribosomal protein CS17, both of which are encoded in the nuclear genome, through the use of the corresponding soybean and pea cDNAs as probes, respectively. The nucleotide sequences of all four cDNAs were determined. The amino acid sequences derived from these cDNA sequences show that the soybean and A. thaliana S11 cDNAs encode proteins that are homologous to rat ribosomal protein S11 and that the pea and A. thaliana CS17 cDNAs encode proteins that are homologous to Escherichia coli ribosomal protein S17. The plant S11 cytosolic ribosomal proteins also show significant sequence similarity to both E. coli ribosomal protein S17 and plastid CS17 indicating that these are all related proteins. Comparison of A. thaliana CS17 with A. thaliana S11 and with E. coli S17 suggests that CS17 is more related to S17 than it is to S11. These results support the idea that the gene encoding CS17 was derived from a prokaryotic endosymbiont and not from a duplication of the eukaryotic S11 gene.}, }
@article {pmid2392479, year = {1990}, author = {Feierabend, J and Kurzok, HG and Schmidt, M}, title = {Genetics and evolution of chloroplast isozymes of triosephosphate isomerase.}, journal = {Progress in clinical and biological research}, volume = {344}, number = {}, pages = {665-682}, pmid = {2392479}, issn = {0361-7742}, mesh = {*Biological Evolution ; Carbohydrate Epimerases/*genetics ; Chloroplasts/*enzymology ; *Genes, Plant ; Isoenzymes/*genetics ; Phylogeny ; Triose-Phosphate Isomerase/*genetics ; Triticum/enzymology/genetics ; }, abstract = {Triosephosphate isomerase is an ubiquitous and highly conservative dimeric enzyme, consisting of subunits of Mr 26,000-27,000. Plants usually contain one cytosolic and one plastid isozyme. While 2x wheats also contain one plastid isozyme, 4x wheats contain 3, and 6x cultural wheats contain five plastid isozymes. The multiplicity of the isozyme pattern in 6x wheats is explainable by the presence of three different genomes (AABBDD), each contributing a distinct triosephosphate isomerase gene (alpha',beta,delta), and by the formation of homodimeric and heterodimeric isozyme forms. While the beta beta-form was, as expected, also found in Aegilops speltoides which is regarded as donor of the B genome, the descent of the other genes for plastid triosephosphate isomerase did not occur in accordance with common contentions on the evolution of 6x cultural wheat and its presumptive ancestors. In the reciprocal intergeneric hybrids between wheat and rye, Secalotricum and Triticale, the patterns of both the cytosolic and the plastid-specific triosephosphate isomerases were biparentally inherited, indicating also that the plastid isozyme was nuclear-encoded. Data which are available about amino acid sequences and gene organization and immunological observations show that the cytosolic triosephosphate isomerase of plants is strongly related to other eukaryotic animal triosephosphate isomerase genes. Multiple evidence has been presented that the plastid- specific isozyme represents a distinct polypeptide and is specified by a distinct gene, relative to the cytosolic isozyme. Immunological comparisons indicate that the plastid isozyme shares homologies with the cytosolic isozyme but is not related to the enzyme from prokaryotic cyanobacteria or bacteria. To enable a more precise comparison, plastid triosephosphate isomerase has been cloned from a cDNA library from rye, and cDNA clones are being sequenced. The plastid enzyme of triosephosphate isomerase appears to have evolved from a duplication on an ancestral nuclear gene of the primordial plant cell. For other plastid-specific isozymes evidence exists that their genes were incorporated into the nucleus by gene transfer from a prokaryotic endosymbiont.}, }
@article {pmid2266771, year = {1990}, author = {Grace, SC}, title = {Phylogenetic distribution of superoxide dismutase supports an endosymbiotic origin for chloroplasts and mitochondria.}, journal = {Life sciences}, volume = {47}, number = {21}, pages = {1875-1886}, doi = {10.1016/0024-3205(90)90399-c}, pmid = {2266771}, issn = {0024-3205}, mesh = {Animals ; Chloroplasts/*enzymology ; Isoenzymes/genetics/*physiology ; Mitochondria/*enzymology ; *Phylogeny ; Plants/enzymology ; Species Specificity ; Superoxide Dismutase/genetics/*physiology ; Symbiosis/genetics ; }, abstract = {Three isozymes of superoxide dismutase (SOD) have been identified and characterized. The iron and manganese isozymes (Fe-SOD and Mn-SOD, respectively) show extensive primary sequence and structural homology, suggesting a common evolutionary ancestor. In contrast, the copper/zinc isozyme (CuZn-SOD) shows no homology with Fe-SOD or Mn-SOD, suggesting an independent origin for this enzyme. The three isozymes are unequally distributed throughout the biological kingdoms and are located in different subcellular compartments. Obligate anaerobes and aerobic diazotrophs contain Fe-SOD exclusively. Facultative aerobes contain either Fe-SOD or Mn-SOD or both. Fe-SOD is found in the cytosol of cyanobacteria while the thylakoid membranes of these organisms contain a tightly bound Mn-SOD. Similarly, most eukaryotic algae contain Fe-SOD in the chloroplast stroma and Mn-SOD bound to the thylakoids. Most higher plants contain a cytosol-specific and a chloroplast-specific CuZn-SOD, and possibly a thylakoid-bound Mn-SOD as well. Plants also contain Mn-SOD in their mitochondria. Likewise, animals and fungi contain a cytosolic CuZn-SOD and a mitochondrial Mn-SOD. The Mn-SOD found in the mitochondria of eukaryotes shows strong homology to the prokaryotic form of the enzyme. Taken together, the phylogenetic distribution and subcellular localization of the SOD isozymes provide strong support for the hypothesis that the chloroplasts and mitochondria of eukaryotic cells arose from prokaryotic endosymbionts.}, }
@article {pmid2103939, year = {1990}, author = {Nakamura, H and Hase, A}, title = {Cellular differentiation in the process of generation of the eukaryotic cell.}, journal = {Origins of life and evolution of the biosphere : the journal of the International Society for the Study of the Origin of Life}, volume = {20}, number = {6}, pages = {499-514}, pmid = {2103939}, issn = {0169-6149}, mesh = {Amino Acid Sequence ; Animals ; *Biological Evolution ; Cell Differentiation ; Eukaryotic Cells/*cytology/metabolism ; Fermentation ; Glyceraldehyde-3-Phosphate Dehydrogenases/genetics ; Humans ; Intracellular Membranes/metabolism ; Models, Biological ; Molecular Sequence Data ; Proteins/genetics ; }, abstract = {Primitive atmosphere of the earth did not contain oxygen gas (O2) when the proto-cells were generated successfully as the result of chemical evolution and then evolved. Therefore, they first had acquired anaerobic energy metabolism, fermentation. The cellular metabolisms have often been formed by reorganizing to combine or recombinate between pre-existing metabolisms and newly born bioreactions. Photosynthetic metabolism in eukaryotic chloroplast consists of an electron-transfer photosystem and a fermentative reductive pentose phosphate cycle. On the other hand, O2-respiration of eukaryotic mitochondrion is made of Embden-Meyerhof (EM) pathway and tricarboxylic acid cycle, which originate from a connection of fermentative metabolisms, and an electron-transfer respiratory chain, which has been derived from the photosystem. These metabolisms already are completed in some evolved prokaryotes, for example the cyanobacterium Chlorogloea fritschii and aerobic photosynthetic bacteria Rhodospirillum rubrum and Erythrobacter sp. Therefore, it can be reasonably presumed that the eukaryotic chloroplast and mitochondrion have once been formed as the result of metabolic (and genetic) differentiations in most evolved cyanobacterium. Symbiotic theory has explained the origin of eukaryotic cell as that in which the mitochondrion and chloroplast have been derived from endosymbionts of aerobic bacterium and cyanobacterium, respectively, and has mentioned as one of the most potent supportive evidences that amino acid sequences of the photosynthetic and O2 -respiratory enzymes show similarities to corresponding prokaryotic enzymes. However, as will be shown in this discussion, many examples have shown currently that prokaryotic sequences of informative molecules are conserved well not only in those of the mitochondrial and chloroplast molecules but also in the nuclear molecules. In fact, the similarities in sequence of informative molecules are preserved well among the organisms not only in phylogenetically close relationships but also under highly selective pressure, that is under a physiological constraint for the species in their habitats. Therefore, the similarities in amino acid sequences of proteins between the prokaryotes and the organelles are not necessarily direct evidence for their phylogenetical closeness: it gives still less evidence for a symbiotic relationship between the prokaryotes and the organelles. The metabolic compartmentalization of the membranes is an important tendency in cellular evolution to guarantee high specificity and rate of the metabolisms. It is suggested from the data that the intracellular membranes are not static but undergo dynamic turnover. Furthermore, these facts strongly support the Membrane Evolution Theory which was proposed by one of the authors in 1975.}, }
@article {pmid2793830, year = {1989}, author = {Martin, GB and Thomashow, MF and Chelm, BK}, title = {Bradyrhizobium japonicum glnB, a putative nitrogen-regulatory gene, is regulated by NtrC at tandem promoters.}, journal = {Journal of bacteriology}, volume = {171}, number = {10}, pages = {5638-5645}, pmid = {2793830}, issn = {0021-9193}, mesh = {Amino Acid Sequence ; Bacterial Proteins/*genetics ; Base Sequence ; *Gene Expression Regulation, Bacterial ; *Genes, Bacterial ; Molecular Sequence Data ; Nitrogen Fixation/*genetics ; PII Nitrogen Regulatory Proteins ; Promoter Regions, Genetic ; RNA, Messenger/genetics ; Restriction Mapping ; Rhizobiaceae/*genetics ; }, abstract = {The glnB gene from Bradyrhizobium japonicum, the endosymbiont of soybeans (Glycine max), was isolated and sequenced, and its expression was examined under various culture conditions and in soybean nodules. The B. japonicum glnB gene encodes a 12,237-dalton polypeptide that is highly homologous to the glnB gene products from Klebsiella pneumoniae and Escherichia coli. The gene is located directly upstream from glnA (encoding glutamine synthetase), a linkage not observed in enteric bacteria. The glnB gene from B. japonicum is expressed from tandem promoters, which are differentially regulated in response to the nitrogen status of the medium. Expression from the downstream promoter involves the B. japonicum ntrC gene product (NtrC) in both free-living and symbiotic cells. Thus, glnB, a putative nitrogen-regulatory gene in B. japonicum, is itself Ntr regulated, and NtrC is active in B. japonicum cells in their symbiotic state.}, }
@article {pmid2571331, year = {1989}, author = {Gupta, RS and Picketts, DJ and Ahmad, S}, title = {A novel ubiquitous protein 'chaperonin' supports the endosymbiotic origin of mitochondrion and plant chloroplast.}, journal = {Biochemical and biophysical research communications}, volume = {163}, number = {2}, pages = {780-787}, doi = {10.1016/0006-291x(89)92290-0}, pmid = {2571331}, issn = {0006-291X}, mesh = {Amino Acid Sequence ; Animals ; Biological Evolution ; Cells, Cultured ; Chaperonins ; *Chloroplasts ; Coxiella ; Cricetinae ; Cricetulus ; Cyanobacteria ; Escherichia coli ; Humans ; *Mitochondria ; Molecular Sequence Data ; Mycobacterium ; *Plants ; *Proteins ; Saccharomyces cerevisiae ; }, abstract = {The deduced amino acid sequences for a major mitochondrial protein (designated P1, related to the 'chaperonin' family of proteins) from human and Chinese hamster cells show extensive similarity (greater than 60% identity observed over the entire length) with a related protein present in evolutionarily as divergent organisms as Escherichia coli, Coxiella burnetii, Mycobacterium species, cyanobacteria as well as in yeast mitochondria and higher plant chloroplasts. Of the different groups of bacteria for which sequence data is available, maximum similarity of the mammalian/yeast P1 protein is observed with the corresponding protein from purple bacteria (especially C. burnetii) while the protein from plant chloroplasts exhibited highest similarity with the corresponding protein from cyanobacteria. The sequence data for this protein thus support the contention that the endosymbiont that gave rise to mitochondrion was a member of purple bacteria, while plant chloroplast originated from a member of the cyanobacterial lineage.}, }
@article {pmid2686121, year = {1989}, author = {Gray, MW}, title = {The evolutionary origins of organelles.}, journal = {Trends in genetics : TIG}, volume = {5}, number = {9}, pages = {294-299}, doi = {10.1016/0168-9525(89)90111-x}, pmid = {2686121}, issn = {0168-9525}, mesh = {*Biological Evolution ; Chloroplasts ; DNA, Mitochondrial ; Mitochondria ; *Organelles ; RNA, Ribosomal/analysis ; Sequence Homology, Nucleic Acid ; }, abstract = {Analysis of organellar genomes strongly supports the idea that chloroplasts and mitochondria originated in evolution as eubacteria-like endosymbionts, whose closest contemporaries are cyanobacteria and purple photosynthetic bacteria, respectively. However, there is still much debate about whether a single endosymbiotic event or multiple ones gave rise to each organelle in different eukaryotes, and considerable uncertainty about what has happened to the genomes of chloroplasts and mitochondria since their appearance in the eukaryotic cell.}, }
@article {pmid2541921, year = {1989}, author = {Thöny-Meyer, L and Stax, D and Hennecke, H}, title = {An unusual gene cluster for the cytochrome bc1 complex in Bradyrhizobium japonicum and its requirement for effective root nodule symbiosis.}, journal = {Cell}, volume = {57}, number = {4}, pages = {683-697}, doi = {10.1016/0092-8674(89)90137-2}, pmid = {2541921}, issn = {0092-8674}, mesh = {Bacteria, Aerobic/*genetics ; Base Sequence ; Cell Membrane/analysis ; Cloning, Molecular ; DNA, Bacterial/analysis ; Electron Transport Complex III/analysis/*genetics ; Gene Expression Regulation ; Genes ; Genes, Bacterial ; Genetic Complementation Test ; Molecular Sequence Data ; *Multigene Family ; Mutation ; Phenotype ; *Plant Physiological Phenomena ; *Symbiosis ; Transcription, Genetic ; }, abstract = {Two adjacent genes in Bradyrhizobium japonicum, fbcF and fbcH, encode the Rieske iron sulfur protein and cytochromes b and c1, characteristic constituents of the respiratory complex III. Remarkably, fbcH is a single gene of which the 5' half codes for cytochrome b and the 3' half codes for cytochrome c1. Experimental evidence suggests that a large FbcH precursor is posttranslationally processed into the two proteins. B. japonicum fbcF and fbcH insertion mutants grow aerobically but are unable to fix nitrogen in root nodule symbiosis with soybean. Thus, fbcF and fbcH are symbiotically essential. We propose that B. japonicum makes use of a cytochrome bc1-containing respiratory chain on its way to become a microaerobic endosymbiont, whereas under aerobiosis, respiration can occur by a bc1-independent pathway.}, }
@article {pmid2651865, year = {1989}, author = {Pond, FR and Gibson, I and Lalucat, J and Quackenbush, RL}, title = {R-body-producing bacteria.}, journal = {Microbiological reviews}, volume = {53}, number = {1}, pages = {25-67}, pmid = {2651865}, issn = {0146-0749}, support = {GM36293/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/analysis/genetics/*ultrastructure ; Bacterial Physiological Phenomena ; *Bacterial Proteins/genetics/ultrastructure ; Bacteriophages ; Paramecium/physiology/ultrastructure ; Plasmids ; Restriction Mapping ; Symbiosis ; }, abstract = {Until 10 years ago, R bodies were known only as diagnostic features by which endosymbionts of paramecia were identified as kappa particles. They were thought to be limited to the cytoplasm of two species in the Paramecium aurelia species complex. Now, R bodies have been found in free-living bacteria and other Paramecium species. The organisms now known to form R bodies include the cytoplasmic kappa endosymbionts of P. biaurelia and P. tetraurelia, the macronuclear kappa endosymbionts of P. caudatum, Pseudomonas avenae (a free-living plant pathogen), Pseudomonas taeniospiralis (a hydrogen-oxidizing soil microorganism), Rhodospirillum centenum (a photosynthetic bacterium), and a soil bacterium, EPS-5028, which is probably a pseudomonad. R bodies themselves fall into five distinct groups, distinguished by size, the morphology of the R-body ribbons, and the unrolling behavior of wound R bodies. In recent years, the inherent difficulties in studying the organization and assembly of R bodies by the obligate endosymbiont kappa, have been alleviated by cloning and expressing genetic determinants for these R bodies (type 51) in Escherichia coli. Type 51 R-body synthesis requires three low-molecular-mass polypeptides. One of these is modified posttranslationally, giving rise to 12 polypeptide species, which are the major structural subunits of the R body. R bodies are encoded in kappa species by extrachromosomal elements. Type 51 R bodies, produced in Caedibacter taeniospiralis, are encoded by a plasmid, whereas bacteriophage genomes probably control R-body synthesis in other kappa species. However, there is no evidence that either bacteriophages or plasmids are present in P. avenae or P. taeniospiralis. No sequence homology was detected between type 51 R-body-encoding DNA and DNA from any R-body-producing species, except C. varicaedens 1038. The evolutionary relatedness of different types of R bodies remains unknown.}, }
@article {pmid2720490, year = {1989}, author = {Lake, JA}, title = {Origin of the eukaryotic nucleus: eukaryotes and eocytes are genotypically related.}, journal = {Canadian journal of microbiology}, volume = {35}, number = {1}, pages = {109-118}, doi = {10.1139/m89-017}, pmid = {2720490}, issn = {0008-4166}, mesh = {*Biological Evolution ; Cell Nucleus/*ultrastructure ; Cells/*ultrastructure ; Eukaryotic Cells/metabolism/*ultrastructure ; Hot Temperature ; Prokaryotic Cells/ultrastructure ; RNA, Ribosomal/genetics ; Sulfur/metabolism ; }, abstract = {The origin of the eukaryotic nucleus is difficult to reconstruct. While eukaryotic organelles (chloroplast, mitochondrion) are eubacterial endosymbionts, the source of nuclear genes has been obscured by multiple nucleotide substitutions. Using evolutionary parsimony, a newly developed rate-invariant treeing algorithm, the eukaryotic rRNA genes are shown to have evolved from the eocytes, a group of extremely thermophilic, sulfur-metabolizing, anucleate cells. The deepest bifurcation yet found separates the reconstructed tree into two taxonomic divisions. These are a proto-eukaryotic group (karyotes) and an essentially bacterial one (parkaryotes). Within the precision of the rooting procedure, the tree is not consistent with either the prokaryotic--eukaryotic or the archaebacterial--eubacterial--eukaryotic groupings. It implies that the last common ancestor of extant life, and the early ancestors of eukaryotes, very likely lacked nuclei, metabolized sulfur, and lived at near boiling temperatures.}, }
@article {pmid2903856, year = {1988}, author = {Martin, GB and Chapman, KA and Chelm, BK}, title = {Role of the Bradyrhizobium japonicum ntrC gene product in differential regulation of the glutamine synthetase II gene (glnII).}, journal = {Journal of bacteriology}, volume = {170}, number = {12}, pages = {5452-5459}, pmid = {2903856}, issn = {0021-9193}, mesh = {*Genes ; *Genes, Bacterial ; *Genes, Regulator ; Glutamate-Ammonia Ligase/*genetics ; Mutation ; Nitrogen/*metabolism ; Plasmids ; Restriction Mapping ; Rhizobiaceae/enzymology/*genetics ; }, abstract = {We isolated the ntrC gene from Bradyrhizobium japonicum, the endosymbiont of soybean (Glycine max), and examined its role in regulating nitrogen assimilation. Two independent ntrC mutants were constructed by gene replacement techniques. One mutant was unable to produce NtrC protein, while the other constitutively produced a stable, truncated NtrC protein. Both ntrC mutants were unable to utilize potassium nitrate as a sole nitrogen source. In contrast to wild-type B. japonicum, the NtrC null mutant lacked glnII transcripts in aerobic, nitrogen-starved cultures. However, the truncated-NtrC mutant expressed glnII in both nitrogen-starved and nitrogen-excess cultures. Both mutants expressed glnII under oxygen-limited culture conditions and in symbiotic cells. These results suggest that nitrogen assimilation in B. japonicum is regulated in response to both nitrogen limitation and oxygen limitation and that separate regulatory networks exist in free-living and symbiotic cells.}, }
@article {pmid2842748, year = {1988}, author = {Kallas, T and Spiller, S and Malkin, R}, title = {Primary structure of cotranscribed genes encoding the Rieske Fe-S and cytochrome f proteins of the cyanobacterium Nostoc PCC 7906.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {85}, number = {16}, pages = {5794-5798}, pmid = {2842748}, issn = {0027-8424}, support = {GM-20571/GM/NIGMS NIH HHS/United States ; RR01865-05/RR/NCRR NIH HHS/United States ; }, mesh = {Amino Acid Sequence ; Base Sequence ; Biological Evolution ; Chromosome Mapping ; Codon ; Cyanobacteria/*genetics ; Cytochrome c Group/analysis ; Cytochromes/analysis/*genetics ; Cytochromes f ; *Electron Transport Complex III ; Iron-Sulfur Proteins/analysis/*genetics ; Metalloproteins/*genetics ; Molecular Sequence Data ; *Transcription, Genetic ; }, abstract = {The thylakoid membrane cytochrome b6-f complex (plastoquinol:oxidized-plastocyanin oxidoreductase, EC 1.10.99.1) catalyzes electron-transfer and proton-translocation reactions essential for oxygenic photosynthesis. We have isolated and determined the nucleotide sequences of the petC and petA genes encoding the Rieske Fe-S and cytochrome f polypeptides from the filamentous cyanobacterium Nostoc PCC 7906. These genes occur as single genomic copies, are tightly linked, and, as indicated by hybridization of gene-specific probes to Nostoc RNA, are cotranscribed as a 2.0-kilobase message. The Rieske Fe-S/cytochrome f gene pair thus represents an example of clustering and cotranscription in cyanobacteria of functionally related genes that, in photosynthetic eukaryotes, reside on separate nuclear and plastid genomes. These data are consistent with the progressive degeneration of the modern chloroplast genome from the ancestral, cyanobacterial-like genome of an endosymbiont. The Rieske Fe-S and the mature cytochrome f apoproteins are encoded by 537 and 867 nucleotides and have molecular masses of 19.2 and 31.2 kDa, respectively. They show 59% and 60% protein sequence identity, respectively, relative to spinach. Forty-four amino acids (4.7 kDa) resembling a prokaryotic signal sequence precede apocytochrome f. In contrast, the Rieske Fe-S protein appears to be translated without a presequence. The 183 bases separating the Rieske Fe-S and preapocytochrome f genes contain two families of 7- to 9-base tandem repeats, and some part of this sequence is highly reiterated in the genome. The C terminus of the Rieske Fe-S protein contains cysteine and histidine residues (probable ligands for the Fe2S2 center) in two peptides, Cys-Thr-His-Leu-Gly-Cys-Val and Cys-Pro-Cys-His-Gly-Ser, which have been conserved in spinach and in the five available Rieske Fe-S sequences from the mitochondrial-type cytochrome b-c1 complexes. Cytochrome f shows the heme binding residues Cys-Xaa-Xaa-Cys-His near its N terminus. Single, long hydrophobic stretches occur near the N and C termini, respectively, of the Rieske Fe-S and cytochrome f proteins and may form membrane-spanning helices.}, }
@article {pmid3286609, year = {1988}, author = {Distel, DL and Lane, DJ and Olsen, GJ and Giovannoni, SJ and Pace, B and Pace, NR and Stahl, DA and Felbeck, H}, title = {Sulfur-oxidizing bacterial endosymbionts: analysis of phylogeny and specificity by 16S rRNA sequences.}, journal = {Journal of bacteriology}, volume = {170}, number = {6}, pages = {2506-2510}, pmid = {3286609}, issn = {0021-9193}, support = {R01 GM34527/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteroidetes/*genetics ; Escherichia coli/*genetics ; Gills/microbiology ; *Marine Biology ; Mollusca/microbiology ; Oxidation-Reduction ; Phylogeny ; RNA, Ribosomal/*analysis ; RNA, Ribosomal, 16S/*analysis ; Sulfur/*metabolism ; Symbiosis ; }, abstract = {The 16S rRNAs from the bacterial endosymbionts of six marine invertebrates from diverse environments were isolated and partially sequenced. These symbionts included the trophosome symbiont of Riftia pachyptila, the gill symbionts of Calyptogena magnifica and Bathymodiolus thermophilus (from deep-sea hydrothermal vents), and the gill symbionts of Lucinoma annulata, Lucinoma aequizonata, and Codakia orbicularis (from relatively shallow coastal environments). Only one type of bacterial 16S rRNA was detected in each symbiosis. Using nucleotide sequence comparisons, we showed that each of the bacterial symbionts is distinct from the others and that all fall within a limited domain of the gamma subdivision of the purple bacteria (one of the major eubacterial divisions previously defined by 16S rRNA analysis [C. R. Woese, Microbiol. Rev. 51: 221-271, 1987]). Two host specimens were analyzed in five of the symbioses; in each case, identical bacterial rRNA sequences were obtained from conspecific host specimens. These data indicate that the symbioses examined are species specific and that the symbiont species are unique to and invariant within their respective host species.}, }
@article {pmid3044395, year = {1988}, author = {Gray, MW}, title = {Organelle origins and ribosomal RNA.}, journal = {Biochemistry and cell biology = Biochimie et biologie cellulaire}, volume = {66}, number = {5}, pages = {325-348}, doi = {10.1139/o88-042}, pmid = {3044395}, issn = {0829-8211}, mesh = {*Biological Evolution ; Mitochondria/metabolism ; RNA, Ribosomal/*genetics ; Subcellular Fractions/*metabolism ; }, abstract = {As the detailed molecular biology of organelle genomes has unfolded, there has been a general acceptance of the view that plastids and mitochondria are of endosymbiotic, eubacterial origin. Plastid genes are strikingly similar to their eubacterial (particularly cyanobacterial) counterparts in sequence, organization, and mode of expression, and such features strongly support the hypothesis that the plastid and its genome were derived in evolution from a blue-green alga-like endosymbiont. Mitochondria, on the other hand, are problematic: mitochondrial genes are organized and expressed in remarkably diverse ways in the different major groups of eukaryotes, and in no case are these features particularly characteristic of either bacterial or nuclear genomes. There is, however, clear evidence derived from gene sequence supporting the eubacterial ancestry of mitochondria, and some of the most compelling data have come from analyses of mitochondrial ribosomal RNA (rRNA). Plant mitochondrial rRNA genes diverge in sequence at a particularly slow rate, and these genes have proven to be especially supportive of the endosymbiont hypothesis, pointing to an origin of mitochondria from within the alpha subdivision of the purple bacteria. Ribosomal RNA sequences provide a basis for the construction of global phylogenetic trees that probe the evolutionary history of organelles, and that address the question of whether mitochondria and plastids are monophyletic or polyphyletic in origin. Such studies raise the possibility that the rRNA genes of plant mitochondria originated separately from the mitochondrial rRNA genes of other eukaryotes.}, }
@article {pmid3353366, year = {1988}, author = {Kohl, DH and Schubert, KR and Carter, MB and Hagedorn, CH and Shearer, G}, title = {Proline metabolism in N2-fixing root nodules: energy transfer and regulation of purine synthesis.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {85}, number = {7}, pages = {2036-2040}, pmid = {3353366}, issn = {0027-8424}, support = {GM38786-01/GM/NIGMS NIH HHS/United States ; S07 RR07054-21/RR/NCRR NIH HHS/United States ; }, mesh = {Animals ; Bacterial Proteins/metabolism ; Energy Transfer ; Fabaceae ; Mitochondria, Liver/metabolism ; *Nitrogen Fixation ; Oxidoreductases Acting on CH-NH Group Donors/*metabolism ; Plants, Medicinal ; Proline/*metabolism ; Proline Oxidase/*metabolism ; Purines/*biosynthesis ; Pyrroline Carboxylate Reductases/metabolism ; Rats ; Rhizobium/*metabolism ; Soybeans ; }, abstract = {N2-fixing root nodules of soybean (Glycine max L. Merr.) convert atmospheric N2 to ammonia(um) in an energy-intensive enzymatic reaction. These nodules synthesize large quantities of purines because nitrogen fixed by bacteria contained within this tissue is transferred to the shoots in the form of ureides, which are degradation products of purines. In animal systems, it has been proposed that proline biosynthesis by pyrroline-5-carboxylate reductase (P5CR) is used to generate the NADP+ required for the synthesis of the purine precursor ribose 5-phosphate. We have examined the levels, properties, and location of P5CR and proline dehydrogenase (ProDH) in soybean nodules. Nodule P5CR was found in the plant cytosol. Its activity was substantially higher than that reported for other animal and plant tissues and is 4-fold higher than in pea (Pisum sativum) nodules (which export amides). The Km for NADPH was lower by a factor of 25 than the Km for NADH, while the Vmax with NADPH was one-third of that with NADH. P5CR activity was diminished by NADP+ but not by proline. These characteristics are consistent with a role for P5CR in supporting nodule purine biosynthesis rather than in producing proline for incorporation into protein. ProDH activity was divided between the bacteroids and plant cytosol, but less than 2% was in the mitochondria-rich fractions. The specific activity of ProDH in soybean nodule bacteroids was comparable to that in rat liver mitochondria. In addition, we propose that some of the proline synthesized in the plant cytosol by P5CR is catabolized within the bacteroids by ProDH and that this represents a novel mechanism for transferring energy from the plant to its endosymbiont.}, }
@article {pmid3368006, year = {1988}, author = {Schubert, I}, title = {Eukaryotic nuclei of endosymbiontic origin?.}, journal = {Die Naturwissenschaften}, volume = {75}, number = {2}, pages = {89-91}, pmid = {3368006}, issn = {0028-1042}, mesh = {Animals ; Biological Evolution ; Cell Nucleus/*physiology ; *Cell Physiological Phenomena ; Chromosomes/physiology ; DNA/genetics ; Eukaryotic Cells/*physiology ; Organoids/physiology ; }, }
@article {pmid3340165, year = {1988}, author = {Lake, JA}, title = {Origin of the eukaryotic nucleus determined by rate-invariant analysis of rRNA sequences.}, journal = {Nature}, volume = {331}, number = {6152}, pages = {184-186}, doi = {10.1038/331184a0}, pmid = {3340165}, issn = {0028-0836}, mesh = {Algorithms ; Base Sequence ; Biological Evolution ; Cell Nucleus ; *Cells/ultrastructure ; *Eukaryotic Cells/ultrastructure ; RNA, Ribosomal/*genetics ; }, abstract = {The origin of the eukaryotic nucleus is difficult to reconstruct. Eukaryotic organelles (chloroplast, mitochondrion) are eubacterial endosymbionts, but the source of nuclear genes has been obscured by multiple nucleotide substitutions. Using evolutionary parsimony, a newly developed rate-invariant treeing algorithm, the eukaryotic ribosomal rRNA genes are shown to have evolved from the eocytes, a group of extremely thermophilic, sulphur-metabolizing, anucleate cells. The deepest bifurcation yet found separates the reconstructed tree into two taxonomic divisions. These are a proto-eukaryotic group (karyotes) and an essentially bacterial one (parkaryotes). Within the precision of the rooting procedure, the tree is not consistent with either the prokaryotic-eukaryotic or the archaebacterial-eubacterial-eukaryotic groupings. It implies that the last common ancestor of extant life, and the early ancestors of eukaryotes, probably lacked nuclei, metabolized sulphur and lived at near-boiling temperatures.}, }
@article {pmid3395682, year = {1988}, author = {Rizzo, PJ and Morris, RL and Zweidler, A}, title = {The histones of the endosymbiont alga of Peridinium balticum (Dinophyceae).}, journal = {Bio Systems}, volume = {21}, number = {3-4}, pages = {231-238}, doi = {10.1016/0303-2647(88)90018-4}, pmid = {3395682}, issn = {0303-2647}, support = {CA-06927/CA/NCI NIH HHS/United States ; CA-15135/CA/NCI NIH HHS/United States ; RR-05539/RR/NCRR NIH HHS/United States ; }, mesh = {Amino Acids/analysis ; Animals ; Dinoflagellida/*genetics ; Eukaryota/*genetics ; Histones/*genetics/isolation &amp; purification ; Molecular Weight ; Peptide Mapping ; Symbiosis ; }, abstract = {The histones of the endosymbiont nucleus of the binucleate dinoflagellate Peridinium balticum were characterized by amino acid analysis and peptide mapping, and compared to calf thymus histones. Using these and various other criteria we have identified two H1-like histones as well as the highly conserved histones H3 and H4. A 13,000 dalton component in sodium dodecyl sulphate (SDS) gels can be separated into two components in Triton-containing gels. We suggest that these histones (HPb1 and HPb2) correspond to the vertebrate histones H2A and H2B, respectively.}, }
@article {pmid3335230, year = {1988}, author = {Schmidt, HJ and Görtz, HD and Pond, FR and Quackenbush, RL}, title = {Characterization of Caedibacter endonucleobionts from the macronucleus of Paramecium caudatum and the identification of a mutant with blocked R-body synthesis.}, journal = {Experimental cell research}, volume = {174}, number = {1}, pages = {49-57}, doi = {10.1016/0014-4827(88)90141-3}, pmid = {3335230}, issn = {0014-4827}, support = {GM36293/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics/*growth &amp; development/ultrastructure ; Cell Nucleus/microbiology ; DNA/isolation &amp; purification ; DNA, Bacterial/isolation &amp; purification ; Microscopy, Electron ; Mutation ; Paramecium/*microbiology/ultrastructure ; Symbiosis ; }, abstract = {Cytology, DNA and host-symbiont relationships of x-like endosymbionts from Paramecium caudatum are described. The symbionts (Caedibacter caryophila, sp. nov.) live in the macronuclei of their hosts. They confer the killer trait upon their hosts and appear well adapted to their endonucleobiotic way of life. R bodies (proteinaceous ribbons associated with killing) are produced, but differ significantly from any of the four R-body classes previously described. C. caryophila and their R bodies were isolated. DNA was extracted from purified symbionts and used to demonstrate that one P. caudatum line harbors a natural mutant which is deficient in R-body production. Melting studies indicate a GC content of 34.6%. No sequence homology between the C. caryophila DNA and the coding sequence for type 51 R-body production was observed. C. caryophila is parasitic, causing the death of its hosts in starving cultures.}, }
@article {pmid3137350, year = {1988}, author = {Van den Eynde, H and De Baere, R and De Roeck, E and Van de Peer, Y and Vandenberghe, A and Willekens, P and De Wachter, R}, title = {The 5S ribosomal RNA sequences of a red algal rhodoplast and a gymnosperm chloroplast. Implications for the evolution of plastids and cyanobacteria.}, journal = {Journal of molecular evolution}, volume = {27}, number = {2}, pages = {126-132}, pmid = {3137350}, issn = {0022-2844}, mesh = {Base Sequence ; *Biological Evolution ; Chloroplasts/analysis ; Cyanobacteria/*genetics ; Molecular Sequence Data ; Nucleic Acid Conformation ; Plants/*genetics ; RNA, Ribosomal/*genetics ; RNA, Ribosomal, 5S/*genetics ; Rhodophyta/*genetics ; Species Specificity ; }, abstract = {The 5S ribosomal RNA sequences have been determined for the rhodoplast of the red alga Porphyra umbilicalis and the chloroplast of the conifer Juniperus media. The 5S RNA sequence of the Vicia faba chloroplast is corrected with respect to a previous report. A survey of the known sequences and secondary structures of 5S RNAs from plastids and cyanobacteria shows a close structural similarity between all 5S RNAs from land plant chloroplasts. The algal plastid 5S RNAs on the other hand show much more structural diversity and have certain structural features in common with bacterial 5S RNAs. A dendrogram constructed from the aligned sequences by a clustering algorithm points to a common ancestor for the present-living cyanobacteria and the land plant plastids. However, the algal plastids branch off at an early stage within the plastid-cyanobacteria cluster, before the divergence between cyanobacteria and land plant chloroplasts. This evolutionary picture points to the occurrence of multiple endosymbiotic events, with the ancestors of the present algal plastids already established as photosynthetic endosymbionts at a time when the ancestors of the present land plant chloroplasts were still free-living cells.}, }
@article {pmid2833325, year = {1988}, author = {Kite, GC and Rothschild, LJ and Dodge, JD}, title = {Nuclear and plastid DNAs from the binucleate dinoflagellates Glenodinium (Peridinium) foliaceum and Peridinium balticum.}, journal = {Bio Systems}, volume = {21}, number = {2}, pages = {151-163}, doi = {10.1016/0303-2647(88)90008-1}, pmid = {2833325}, issn = {0303-2647}, mesh = {Animals ; Cell Nucleus/analysis ; Centrifugation, Density Gradient ; DNA/*analysis/isolation &amp; purification ; DNA Restriction Enzymes/metabolism ; Dinoflagellida/*genetics ; Electrophoresis, Agar Gel ; Kinetics ; Transfection ; Ultracentrifugation ; }, abstract = {The binucleate dinoflagellates Glenodinium (Peridinium) foliaceum Stein and Peridinium balticum (Levander) Lemmermann were found to contain two major buoyant density classes of DNA. The heavier peak (1.730 g/cm3) was derived from the "dinokaryotic" nucleus and the lighter peak (1.706 g/cm3) from the "endosymbiont" nucleus and this allowed for the fractionation of G. foliaceum DNA in CsCl/EtBr density gradients. An initial CsCl/Hoechst Dye gradient removed a minor A-T rich satellite species which was identified as plastid DNA with a size of about 100-106 kb. Analysis of the nuclear DNA by agarose gel electrophoresis and renaturation studies showed that the endosymbiont nucleus lacked amplified gene-sized DNA molecules, however, this nucleus did have a comparatively high level of DNA. The total amount of DNA per cell and the relative contributions of the two nuclei appeared to vary between two strains of G. foliaceum (75 pg/cell in CCAP strain and 58 pg in UTEX strain). The only strain of P. balticum examined contained 73 pg cell. These results are discussed in relation to the status and possible functioning of the endosymbiont nucleus and the idea that these dinoflagellates provide model systems with which to study the evolution of plastids.}, }
@article {pmid3503180, year = {1987}, author = {Rozental, S and de Carvalho, TU and de Souza, W}, title = {Influence of the endosymbiont on the interaction of Crithidia deanei with macrophages.}, journal = {Microscopia electronica y biologia celular : organo oficial de las Sociedades Latinoamericana de Microscopia Electronica e Iberoamericana de Biologia Celular}, volume = {11}, number = {2}, pages = {167-177}, pmid = {3503180}, issn = {0326-3142}, mesh = {Animals ; Crithidia/*physiology/ultrastructure ; Endocytosis ; Macrophages/*parasitology/ultrastructure ; Mice ; Microscopy, Electron ; *Symbiosis ; }, }
@article {pmid3037278, year = {1987}, author = {So, JS and Hodgson, AL and Haugland, R and Leavitt, M and Banfalvi, Z and Nieuwkoop, AJ and Stacey, G}, title = {Transposon-induced symbiotic mutants of Bradyrhizobium japonicum: isolation of two gene regions essential for nodulation.}, journal = {Molecular &amp; general genetics : MGG}, volume = {207}, number = {1}, pages = {15-23}, pmid = {3037278}, issn = {0026-8925}, support = {1-RO1-GM 33494-O1A1/GM/NIGMS NIH HHS/United States ; }, mesh = {*DNA Transposable Elements ; DNA, Bacterial/genetics ; DNA, Recombinant ; *Genes, Bacterial ; Nitrogen Fixation ; Rhizobiaceae/*genetics/physiology ; Rhizobium/genetics ; Sequence Homology, Nucleic Acid ; Soybeans/*microbiology ; Species Specificity ; *Symbiosis ; }, abstract = {Two strains of the soybean endosymbiont Bradyrhizobium japonicum, USDA 110 and 61 A101 C, were mutagenized with transposon Tn5. After plant infection tests of a total of 6,926 kanamycin and streptomycin resistant transconjugants, 25 mutants were identified that are defective in nodule formation (Nod-) or nitrogen fixation (Fix-). Seven Nod- mutants were isolated from strain USDA110 and from strain 61 A101 C, 4 Nod- mutants and 14 Fix- mutants were identified. Subsequent auxotrophic tests on these symbiotically defective mutants identified 4 His- Nod- mutants of USDA110. Genomic Southern analysis of the 25 mutants revealed that each of them carried a single copy of Tn5 integrated in the genome. Three 61 A101 C Fix- mutants were found to have vector DNA co-integrated along with Tn5 in the genome. Two independent DNA regions flanking Tn5 were cloned from the three non-auxotrophic Nod- mutants and one His-Nod- mutant of USDA110. Homogenotization of the cloned fragments into wild-type strain USDA110 and subsequent nodulation assay of the resulting homogenotes confirmed that the Tn5 insertion was responsible for the Nod- phenotype. Partial EcoR1 restriction enzyme maps around the Tn5 insertion sites were generated. Hybridization of these cloned regions to the previously cloned nod regions of R. meliloti and nif and nod regions of B. japonicum USDA110 showed no homology, suggesting that these regions represent new symbiotic clusters of B. japonicum.}, }
@article {pmid2881918, year = {1987}, author = {Szeto, WW and Nixon, BT and Ronson, CW and Ausubel, FM}, title = {Identification and characterization of the Rhizobium meliloti ntrC gene: R. meliloti has separate regulatory pathways for activation of nitrogen fixation genes in free-living and symbiotic cells.}, journal = {Journal of bacteriology}, volume = {169}, number = {4}, pages = {1423-1432}, pmid = {2881918}, issn = {0021-9193}, mesh = {Base Sequence ; Chromosome Mapping ; Chromosomes, Bacterial ; Cloning, Molecular ; DNA Transposable Elements ; DNA, Bacterial/genetics ; Genes, Bacterial ; *Genes, Regulator ; Genetic Linkage ; Glutamate-Ammonia Ligase/genetics ; Mutation ; *Nitrogen Fixation ; Phenotype ; Promoter Regions, Genetic ; Rhizobium/*genetics/metabolism/physiology ; Symbiosis ; Transcription, Genetic ; }, abstract = {We show here that Rhizobium meliloti, the nitrogen-fixing endosymbiont of alfalfa (Medicago sativa), has a regulatory gene that is structurally homologous to previously characterized ntrC genes in enteric bacteria. DNA sequence analysis showed that R. meliloti ntrC is homologous to previously sequenced ntrC genes from Klebsiella pneumoniae and Bradyrhizobium sp. (Parasponia) and that an ntrB-like gene is situated directly upstream from R. meliloti ntrC. Similar to its counterparts in K. pneumoniae and Escherichia coli, R. meliloti ntrC is expressed when the cells are grown in nitrogen-limiting media. In addition, R. meliloti ntrC is required for growth on media containing nitrate as the sole nitrogen source and for the ex planta transcription of several R. meliloti nif genes. On the other hand, root nodules elicited by R. meliloti ntrC mutants fix nitrogen as well as nodules elicited by wild-type R. meliloti. These latter results indicate that R. meliloti has separate regulatory pathways for activating nif gene expression ex planta and during symbiotic nitrogen fixation.}, }
@article {pmid3689888, year = {1987}, author = {Chesnick, JM and Cox, ER}, title = {Synchronized sexuality of an algal symbiont and its dinoflagellate host, Peridinium balticum (Levander) Lemmermann.}, journal = {Bio Systems}, volume = {21}, number = {1}, pages = {69-78}, doi = {10.1016/0303-2647(87)90007-4}, pmid = {3689888}, issn = {0303-2647}, mesh = {Animals ; Biological Evolution ; Cell Nucleus/ultrastructure ; Dinoflagellida/*physiology/ultrastructure ; Eukaryota/*physiology/ultrastructure ; Meiosis ; Microscopy, Electron ; Reproduction ; *Symbiosis ; }, abstract = {We report synchronized sexual reproduction between the chlorophyll c-containing algal endosymbiont and its dinoflagellate host in Peridinium balticum (Pyrrhophyta). This organism's importance lies in that it may represent an intermediate between primitive non-photosynthetic and advanced photosynthetic dinoflagellates. Fusion of the endosymbionts and their nuclei occurred concomitantly with syngamy of the host gametes. Significant morphological changes, including condensation of chromatin and crystalline rod formation, occurred in the symbiont nucleus during zygote development. These observations provide evidence that the endosymbiotic nucleus is not passive in sexual processes, as opposed to its reported passive state during mitosis. P. balticum may not only represent an intermediate in the evolution of chloroplast acquisition by dinoflagellates, but also, an intermediate in the evolution of the peridinian dinoflagellate sexual life history.}, }
@article {pmid3557112, year = {1987}, author = {Landis, WG}, title = {Factors determining the frequency of the killer trait within populations of the Paramecium aurelia complex.}, journal = {Genetics}, volume = {115}, number = {1}, pages = {197-205}, pmid = {3557112}, issn = {0016-6731}, support = {PHS R01 6M 20038-05/PH/PHPPO CDC HHS/United States ; }, mesh = {Alleles ; Animals ; Computer Simulation ; Conjugation, Genetic ; Gene Frequency ; Paramecium/*genetics/physiology ; Selection, Genetic ; }, abstract = {The factors maintaining the cytoplasmically inherited killer trait in populations of Paramecium tetraurelia and Paramecium biaurelia were examined using, in part, computer simulation. Frequency of the K and k alleles, infection and loss of the endosymbionts, recombination during conjugation and autogamy, cytoplasmic exchange and natural selection were incorporated in a model. Infection during cytoplasmic exchange at conjugation and natural selection were factors that would increase the proportion of killers in a population. Conversely, k alleles reduced the proportion of killers in a population, acting through conjugation and autogamy. Field studies indicate that the odd mating type is prevalent in P. tetraurelia isolated from nature. Conjugation and therefore transmission by cytoplasmic transfer would be rare. Competition studies indicate a strong selective disadvantage for sensitives at concentrations found in nature. Natural selection must therefore be the factor maintaining the killer trait in P. tetraurelia.}, }
@article {pmid3116275, year = {1987}, author = {Mikelsaar, R}, title = {A view of early cellular evolution.}, journal = {Journal of molecular evolution}, volume = {25}, number = {2}, pages = {168-183}, pmid = {3116275}, issn = {0022-2844}, mesh = {Animals ; *Biological Evolution ; DNA, Mitochondrial/genetics ; Genetic Code ; *Models, Genetic ; Phylogeny ; Species Specificity ; }, abstract = {Some recent puzzling data on mitochondria put in question their place on the phylogenetic tree. A hypothesis, the archigenetic hypothesis, is presented, which generally agrees with Woese-Fox's concept of the common origin of eubacteria, archaebacteria, and eukaryotic hosts. However, for the first time, a case is made for the evolution of mitochondria from the ancient predecessors of pro- and eukaryotes (protobionts), not from eubacteria. Animal, fungal, and plant mitochondria are considered to be endosymbionts derived from independent free-living cells (mitobionts), which, having arisen at different developmental stages of protobionts, retained some of their ancient primitive features of the genetic code and the transcription-translation systems. The molecular-biological, bioenergetic, and paleontological aspects of this new concept of cellular evolution are discussed.}, }
@article {pmid2446672, year = {1987}, author = {Benne, R and Sloof, P}, title = {Evolution of the mitochondrial protein synthetic machinery.}, journal = {Bio Systems}, volume = {21}, number = {1}, pages = {51-68}, doi = {10.1016/0303-2647(87)90006-2}, pmid = {2446672}, issn = {0303-2647}, mesh = {Animals ; *Biological Evolution ; Eukaryota/genetics/metabolism ; Mitochondria/*metabolism ; *Protein Biosynthesis ; RNA/genetics/metabolism ; RNA, Mitochondrial ; Ribosomal Proteins/genetics/metabolism ; Ribosomes/metabolism ; }, abstract = {Comparative analysis of the components of the mitochondrial translational apparatus reveals a remarkable variability. For example the mitochondrial ribosomal rRNAs, display a three-fold difference in size in different organisms as a result of insertions or deletions, which affect specific areas of the rRNA molecule. This suggests that such areas are either not essential for mitoribosome function or that they can be replaced by proteins. Also mitochondrial tRNAs and mitoribosomal proteins are much less conserved than their cytoplasmic counterparts. Not only do the mitochondrial translational molecules vary in properties, also the location of the genes from which they are derived is not the same in all cases: mitochondrial tRNA genes which usually are found in the mtDNA, may have a nuclear location in protozoa and, conversely, only in fungi one finds a mitoribosomal protein gene in the organellar genome. The high rate of change of the components of the mitochondrial protein synthesizing machinery is accompanied by a number of unique features of the translation process: (i) the mitochondrial genetic code differs substantially from the standard code in a species-specific manner; (ii) special codon-anticodon recognition rules are followed; (iii) unusual mechanisms of translational initiation may exist. These observations suggest that the evolutionary pressures that have shaped the present day mitochondrial translational apparatus have been different in different organisms and also distinct from those acting on the cytoplasmic machinery. In spite of the interspecies variability, however, many features of the mitochondrial and bacterial protein synthetic apparatus show a clear resemblance, providing support for the hypothesis of a prokaryotic endosymbiont ancestry of mitochondria.}, }
@article {pmid3759909, year = {1986}, author = {Kanabrocki, JA and Quackenbush, RL and Pond, FR}, title = {Organization and expression of genetic determinants for synthesis and assembly of type 51 R bodies.}, journal = {Journal of bacteriology}, volume = {168}, number = {1}, pages = {40-48}, pmid = {3759909}, issn = {0021-9193}, support = {GM36293/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Bacteria/genetics/metabolism/*ultrastructure ; Bacterial Proteins/biosynthesis/*genetics ; Cloning, Molecular ; Gene Expression Regulation ; *Genes, Bacterial ; Paramecium/microbiology ; Symbiosis ; Transcription, Genetic ; }, abstract = {Type 51 R bodies are produced by all bacterial endosymbionts (Caedibacter taeniospiralis) of Paramecium tetraurelia that confer the hump-killer trait upon their hosts. Type 51 R-body synthesis by C. taeniospiralis is required for expression of the hump-killer trait. The genetic determinants for type 51 R-body synthesis by C. taeniospiralis 47 have been cloned and expressed in Escherichia coli. In this communication we describe three species of polypeptides required for R-body synthesis and the organization of their genetic determinants. Each polypeptide species is controlled by a separate gene that is expressed as an independent transcriptional unit possessing regulatory signals that are recognized by E. coli. Two polypeptide species of 10 and 18 kilodaltons are required for R-body synthesis but apparently are not structural subunits. The third polypeptide species (13 kilodaltons) is the major structural subunit. R-body assembly involves polymerization reactions that result in high-molecular-mass polypeptide complexes, primarily composed of the 13-kilodalton polypeptide species, that appear to be the result of covalent cross-linking between structural subunits. The results presented here have been suggested to apply to the assembly and structure of all type 51 R bodies, but not necessarily to other R-body types.}, }
@article {pmid3020008, year = {1986}, author = {Soldo, AT and Brickson, SA and Castiglione, GA and Freytag, AF}, title = {Association of transformation of xenosomes from nonkiller to killer with extrachromosomal DNA.}, journal = {Journal of bacteriology}, volume = {168}, number = {1}, pages = {96-102}, pmid = {3020008}, issn = {0021-9193}, mesh = {Animals ; Bacteria/*genetics ; Bacterial Physiological Phenomena ; Ciliophora/microbiology ; DNA Restriction Enzymes ; DNA, Bacterial/analysis ; Deoxyribonuclease BamHI ; *Plasmids ; Symbiosis ; }, abstract = {Extrachromosomal DNA in the form of covalently closed circular DNA molecules was isolated from killer and nonkiller xenosomes, bacterial endosymbionts of the marine protozoan Parauronema acutum. Restriction endonuclease digests of these molecules derived from 12 isolates revealed consistent, readily identifiable, differences in the pattern of fragments of the killer as compared with those present in the nonkiller. Transformation of the nonkiller to killer by infection is also accompanied by a change from the nonkiller to killer pattern. Based on analysis of fragments resulting from restriction endonuclease digests, two circular duplex DNA molecules, each 63 kilobase pairs (kbp) in length, were identified in the 263-20 nonkiller stock and mapped. The maps revealed that each possesses a single BamHI site and multiple BglI, BstIIE, PstI, and SalI sites. A distinguishing feature of these maps is that the two molecules share a region about 17 kbp in length in which multiple restriction sites are in register with each other. Allowing for a 0.5-kbp insertion or deletion and the introduction or removal of only a few restriction sites, an additional stretch extending approximately 31 kbp beyond this sequence could also be considered to be homologous. The structure of the killer plasmid appears to be more complex, and we have been unable, as yet, to construct physical maps for this DNA. We postulate that the killer plasmid DNA is composed of three, perhaps four, circular 63-kbp duplexes, at least one which contains a single BamHI site and another which contains two BamHI sites. The remaining molecules may represent copies of either or both of the other two, modified to contain additional restriction sites. Transformation from the nonkiller to the killer is visualized as the insertion of restriction sites at various points along parent nonkiller plasmid DNA molecules. The mechanism by which these sites are introduced is unknown.}, }
@article {pmid2484670, year = {1986}, author = {Ishikawa, H and Hashimoto, H}, title = {The molecular biology of symbiotic bacteria of aphididae.}, journal = {Microbiological sciences}, volume = {3}, number = {4}, pages = {117-120}, pmid = {2484670}, issn = {0265-1351}, mesh = {Animals ; Aphids/*microbiology ; Bacteria/genetics/*metabolism ; Bacterial Proteins/biosynthesis ; DNA, Bacterial/biosynthesis ; RNA, Bacterial/biosynthesis ; *Symbiosis ; }, abstract = {The aphid endosymbiont has a genome larger than that of E. coli, with a high adenine and thymine content. Though the symbiont can synthesize several hundred proteins in vitro, intracellularly it concentrates on producing only one protein, symbionin, which is not among those synthesized extracellularly.}, }
@article {pmid3767641, year = {1986}, author = {Silard, R and Burghelea, B}, title = {Endosymbionts in Dientamoeba fragilis trophozoites resistant to antiprotozoal drugs.}, journal = {Archives roumaines de pathologie experimentales et de microbiologie}, volume = {45}, number = {1}, pages = {65-74}, pmid = {3767641}, issn = {0004-0037}, mesh = {Animals ; Antiprotozoal Agents/*antagonists &amp; inhibitors ; Dientamoeba/drug effects/*microbiology/ultrastructure ; Drug Resistance ; Gram-Negative Bacteria/ultrastructure ; Microscopy, Electron ; *Symbiosis ; }, }
@article {pmid3032139, year = {1986}, author = {Quackenbush, RL and Cox, BJ and Kanabrocki, JA}, title = {Extrachromosomal elements of extrachromosomal elements of Paramecium and their extrachromosomal elements.}, journal = {Basic life sciences}, volume = {40}, number = {}, pages = {265-278}, doi = {10.1007/978-1-4684-5251-8_21}, pmid = {3032139}, issn = {0090-5542}, support = {GM36293/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; DNA Restriction Enzymes ; *DNA Transposable Elements ; Gram-Negative Bacteria/*genetics/ultrastructure ; Microscopy, Electron ; Paramecium/*genetics/microbiology ; Symbiosis ; }, abstract = {Expression of killer traits in Paramecium is due to a complex interaction between the lower eukaryote host and two or three elements that can be viewed either as extrachromosomal elements or as endosymbionts. In all cases, the determinants of the killer trait are carried by obligate bacterial endosymbionts belonging to the genus Caedibacter. However, the actual genetic determinants for expression of these traits are not an integral part of the symbiont genome. They are located on extrachromosomal genetic elements (plasmids or bacteriophages) which essentially are molecular endosymbionts of Caedibacter. In the case of the plasmids, they are associated with yet another set of extrachromosomal genetic elements, which are transposons. These transposons have been observed to move into new sites in the plasmids and even to disrupt expression of R body production and the killer trait. Thus, the transposons can be considered either as extrachromosomal elements of extrachromosomal elements (plasmids) of extrachromosomal elements (C. taeniospiralis) of paramecia, or as molecular parasites of molecular endosymbionts (plasmids) of bacterial endosymbionts of paramecia.}, }
@article {pmid2869943, year = {1986}, author = {Nierzwicki-Bauer, SA and Haselkorn, R}, title = {Differences in mRNA levels in Anabaena living freely or in symbiotic association with Azolla.}, journal = {The EMBO journal}, volume = {5}, number = {1}, pages = {29-35}, pmid = {2869943}, issn = {0261-4189}, support = {GM 21823/GM/NIGMS NIH HHS/United States ; }, mesh = {Chlorophyll/genetics ; *Cloning, Molecular ; Cyanobacteria/*genetics/physiology ; *Genes ; Glutamate-Ammonia Ligase/genetics ; Light-Harvesting Protein Complexes ; Nitrogenase/genetics ; Photosynthetic Reaction Center Complex Proteins ; Photosystem II Protein Complex ; *Plant Physiological Phenomena ; Plant Proteins/genetics ; RNA, Messenger/*genetics/isolation &amp; purification ; Ribulose-Bisphosphate Carboxylase/genetics ; *Symbiosis ; Transcription, Genetic ; }, abstract = {Azolla is a small water fern in whose leaf cavities the filamentous nitrogen-fixing cyanobacterium Anabaena azollae is symbiotically associated. Using cloned genes from Anabaena 7120 for glutamine synthetase (GS), ribulose-1,5-bisphosphate (RuBP) carboxylase, nitrogenase and the 32-kd protein of photosystem II, mRNA levels of the corresponding genes in the Anabaena endosymbiont were studied by Northern hybridization. In RNA isolated from the endosymbiont there is a 10-fold reduction of GS transcript levels, a greater than 5-fold increase in 32-kd transcript levels and a greater than 5-fold decrease in RuBP carboxylase transcript levels, compared with levels in the free-living Anabaena azollae. In the endosymbiont and in heterocysts of the free-living Anabaena azollae the nif H, nif D, and nif K genes are transcribed from a single nif HDK operon.}, }
@article {pmid3932327, year = {1985}, author = {Lambert, DH and Bryant, DA and Stirewalt, VL and Dubbs, JM and Stevens, SE and Porter, RD}, title = {Gene map for the Cyanophora paradoxa cyanelle genome.}, journal = {Journal of bacteriology}, volume = {164}, number = {2}, pages = {659-664}, pmid = {3932327}, issn = {0021-9193}, support = {GM 31625/GM/NIGMS NIH HHS/United States ; }, mesh = {Animals ; Chloroplasts ; Cloning, Molecular ; Cyanobacteria/genetics ; Eukaryota/*genetics/ultrastructure ; *Genes ; Nucleic Acid Hybridization ; Organoids ; Photosynthesis ; Phycocyanin/genetics ; RNA, Ribosomal/genetics ; Ribulose-Bisphosphate Carboxylase/genetics ; }, abstract = {The genes for the following proteins were localized by hybridization analysis on the cyanelle genome of Cyanophora paradoxa: the alpha and beta subunits of phycocyanin (cpcA and cpcB); the alpha and beta subunits of allophycocyanin (apcA and apcB); the large and small subunits of ribulose-1,5-bisphosphate carboxylase (rbcL and rbcS); the two putative chlorophyll alpha-binding apoproteins of the photosystem I-P700 complex (psaA and psaB); four apoproteins believed to be components of the photosystem II core complex (psbA, psbB, psbC, and psbD); the two apoprotein subunits of cytochrome b-559 which is also found in the core complex of photosystem II (psbE and psbF); three subunits of the ATP synthase complex (atpA and atpBE); and the cytochrome f apoprotein (petA). Eighty-five percent of the genome was cloned as BamHI, BglII, or PstI fragments. These cloned fragments were used to construct a physical map of the cyanelle genome and to localize more precisely some of the genes listed above. The genes for phycocyanin and allophycocyanin were not clustered and were separated by about 25 kilobases. Although the rbcL gene was adjacent to the atpBE genes and the psbC and psbD genes were adjacent, the arrangement of other genes encoding various polypeptide subunits of protein complexes involved in photosynthetic functions was dissimilar to that observed for known chloroplast genomes. These results are consistent with the independent development of this cyanelle from a cyanobacterial endosymbiont.}, }
@article {pmid4052383, year = {1985}, author = {Rauhut, R and Gabius, HJ and Cramer, F}, title = {Evolutionary aspects of accuracy of phenylalanyl-tRNA synthetase. Accuracy of the cytoplasmic and chloroplastic enzymes of a higher plant (Phaseolus vulgaris).}, journal = {Biochemistry}, volume = {24}, number = {15}, pages = {4052-4057}, doi = {10.1021/bi00336a038}, pmid = {4052383}, issn = {0006-2960}, mesh = {Amino Acyl-tRNA Synthetases/*genetics ; Animals ; *Biological Evolution ; Chloroplasts/*enzymology ; Cytoplasm/enzymology ; Kinetics ; Phenylalanine-tRNA Ligase/*genetics/metabolism ; Plants/*enzymology ; Species Specificity ; Substrate Specificity ; }, abstract = {The phenylalanyl-tRNA synthetases from cytoplasm and chloroplasts of bean (Phaseolus vulgaris) leaves employ different strategies with respect to accuracy. The chloroplastic enzyme that is coded for by the nuclear genome follows the pathway of posttransfer proofreading, also characteristic for enzymes from eubacteria and cytoplasm and mitochondria of lower eukaryotic organisms. In contrast, the cytoplasmic enzyme uses pretransfer proofreading in the case of noncognate natural amino acids, characteristic for higher eukaryotic organisms and archaebacteria. Dependent on the nature of the noncognate amino acid, pretransfer proofreading in this case occurs without tRNA stimulation or with tRNA stimulated with no or little effect of the nonaccepting 3'-OH group of the terminal adenosine. The fundamental mechanistic difference in proofreading between the heterotopic intracellular isoenzymes of the plant cell supports the idea of the origin of the chloroplastic gene by gene transfer from a eubacterial endosymbiont to the nucleus. Origin by duplication of the nuclear gene, as indicated for mitochondrial phenylalanyl-tRNA synthetases [Gabius, H.-J., Engelhardt, R., Schroeder, F.R., &amp; Cramer, F. (1983) Biochemistry 22, 5306-5315], appears unlikely. Further analyses of the ATP/PPi pyrophosphate exchange and aminoacylation of tRNAPhe-C-C-A(3'NH2), using 11 phenylalanine analogues, reveal intraspecies and interspecies variability of the architecture of the amino acid binding part within the active site.}, }
@article {pmid3892535, year = {1985}, author = {Yang, D and Oyaizu, Y and Oyaizu, H and Olsen, GJ and Woese, CR}, title = {Mitochondrial origins.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {82}, number = {13}, pages = {4443-4447}, pmid = {3892535}, issn = {0027-8424}, support = {AM-34527/AM/NIADDK NIH HHS/United States ; }, mesh = {Base Sequence ; Escherichia coli/genetics ; *Mitochondria ; Phylogeny ; Pseudomonas/*ultrastructure ; RNA, Ribosomal/analysis ; Rhizobium/*ultrastructure ; }, abstract = {The 16S ribosomal RNA sequences from Agrobacterium tumefaciens and Pseudomonas testosteroni have been determined to further delimit the origin of the endosymbiont that gave rise to the mitochondrion. These two prokaryotes represent the alpha and beta subdivisions, respectively, of the so-called purple bacteria. The endosymbiont that gave rise to the mitochondrion belonged to the alpha subdivision, a group that also contains the rhizobacteria, the agrobacteria, and the rickettsias--all prokaryotes that have developed intracellular or other close relationships with eukaryotic cells.}, }
@article {pmid3981353, year = {1985}, author = {Hall, J and Voelz, H}, title = {Bacterial endosymbionts of Acanthamoeba sp.}, journal = {The Journal of parasitology}, volume = {71}, number = {1}, pages = {89-95}, pmid = {3981353}, issn = {0022-3395}, support = {S07-RR05433-18/RR/NCRR NIH HHS/United States ; }, mesh = {Amoeba/*microbiology/ultrastructure ; Animals ; Cytoplasm/ultrastructure ; Microscopy, Electron ; *Symbiosis ; }, abstract = {Gimenez staining of presumably axenic Acanthamoeba sp., strain HN-3, showed rod-shaped cytoplasmic inclusions. Electron microscopy of thin sections of the amebae showed these to be bacilli which measured 1.3 to 3.3 microns by 0.22 to 0.33 micron. Their cell envelopes were those typical of gram-negative bacteria, surrounded by an electron-translucent area that stains with ruthenium red, suggesting the presence of a capsule. The bacilli grew and reproduced in the cytoplasm of both trophozoites and cysts of Acanthamoeba sp. There was no evidence of a surrounding phagosomal or phagolysosomal membrane. They were retained by the ameba both during encystment and excystment. All attempts to isolate the endosymbionts in embryonated eggs and/or standard bacteriological media failed; and they persisted within the amebae for 1 to 6 mo despite temperature shocking or constant treatment of cultures with penicillin, streptomycin, chloramphenicol, tetracycline, erythromycin, polymyxin B, ampicillin, isoniazid, rifampicin, or gentamycin at concentrations of 10(-5) to 10(-3) M.}, }
@article {pmid3931719, year = {1985}, author = {Ishikawa, H and Yamaji, M}, title = {Protein synthesis by intracellular symbionts in two closely interrelated aphid species.}, journal = {Bio Systems}, volume = {17}, number = {4}, pages = {327-335}, doi = {10.1016/0303-2647(85)90048-6}, pmid = {3931719}, issn = {0303-2647}, mesh = {Animals ; Aphids/metabolism/*microbiology ; Bacterial Proteins/*biosynthesis ; *Chaperonins ; Cycloheximide/pharmacology ; Protein Biosynthesis ; Proteins/isolation &amp; purification ; Rickettsiaceae/*metabolism ; Species Specificity ; }, abstract = {An aphid endosymbiont in vivo synthesizes symbionin almost exclusively which is not produced in vitro by the same symbiont. While symbionin produced by the endosymbiont of the pea aphid is an acidic protein with a molecular weight of 63,000, that by the symbiont of the kondo aphid, the closest relative to the former, is a distinct, less acidic, molecule. While the two endosymbionts in vivo in old insects synthesize about 11 protein species in common, they produce many different proteins when incubated extracellularly.}, }
@article {pmid6326060, year = {1984}, author = {Douglas, SE and Doolittle, WF}, title = {Complete nucleotide sequence of the 23S rRNA gene of the Cyanobacterium, Anacystis nidulans.}, journal = {Nucleic acids research}, volume = {12}, number = {7}, pages = {3373-3386}, pmid = {6326060}, issn = {0305-1048}, mesh = {Base Sequence ; Cyanobacteria/*genetics ; DNA Restriction Enzymes ; Escherichia coli/genetics ; *Genes ; Molecular Weight ; Nucleic Acid Conformation ; RNA, Ribosomal/*genetics ; Species Specificity ; Transcription, Genetic ; }, abstract = {The nucleotide sequence of the Anacystis nidulans 23S rRNA gene, including the 5'- and 3'-flanking regions has been determined. The gene is 2876 nucleotides long and shows higher primary sequence homology to the 23S rRNAs of plastids (84.5%) than to that of E. coli (79%). The predicted rRNA transcript also shares many secondary structural features with those of plastids, reinforcing the endosymbiont hypothesis for the origin of these organelles.}, }
@article {pmid6582483, year = {1984}, author = {Somerson, NL and Ehrman, L and Kocka, JP and Gottlieb, FJ}, title = {Streptococcal L-forms isolated from Drosophila paulistorum semispecies cause sterility in male progeny.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {81}, number = {1}, pages = {282-285}, pmid = {6582483}, issn = {0027-8424}, mesh = {Crosses, Genetic ; Drosophila/*microbiology/physiology ; Female ; Infertility, Male/*microbiology ; L Forms/isolation &amp; purification/*pathogenicity ; Male ; Streptococcus/isolation &amp; purification/*pathogenicity ; }, abstract = {The Drosophila paulistorum complex contains six semispecies that do not normally interbreed. In the laboratory, crosses between semispecies produce fertile daughters and sterile sons. Microbial endosymbionts have been observed in all D. paulistorum flies that display this male sterility. Streptococcal L-forms have been isolated from the Andean-Brazilian (Mesitas) and Transitional (Santa Marta) semispecies and cultured in artificial medium. Transfer of these L-forms from their native hosts into reciprocal semispecies resulted in sterile male progeny. When L-forms were inoculated into the semispecies from which they had been isolated, most of the male progeny were fertile. Control streptococcal L-forms did not show this sterility pattern.}, }
@article {pmid6442121, year = {1984}, author = {Vogels, GD and van der Drift, C and Stumm, CK and Keltjens, JT and Zwart, KB}, title = {Methanogenesis: surprising molecules, microorganisms and ecosystems.}, journal = {Antonie van Leeuwenhoek}, volume = {50}, number = {5-6}, pages = {557-567}, pmid = {6442121}, issn = {0003-6072}, mesh = {Acetates/metabolism ; Anaerobiosis ; Animals ; Bacteria/*metabolism ; Carbon Dioxide/metabolism ; Chemical Phenomena ; Chemistry ; Coenzymes/metabolism ; Electron Transport ; Eukaryota/metabolism ; Euryarchaeota/metabolism ; Formates/metabolism ; Hydrogen/metabolism ; Methane/*biosynthesis ; Methanol/metabolism ; Microscopy, Electron ; Species Specificity ; Symbiosis ; }, abstract = {Methanogenesis involves a novel set of coenzymes as one-carbon and electron carriers. Consequently, metabolic processes of methanogens deviate from those present in non-methanogenic bacteria. Methanogenic bacteria can be classified on the basis of substrate utilization. Group I (24 species) grows at the expense of hydrogen plus CO2 and/or formate and group II (7 species) uses methanol and/or acetate. Hydrogen-consuming methanogens are found as epi- or endosymbionts of anaerobic ciliates.}, }
@article {pmid6441609, year = {1984}, author = {Ishikawa, H}, title = {Alteration with age of symbiosis of gene expression in aphid endosymbionts.}, journal = {Bio Systems}, volume = {17}, number = {2}, pages = {127-134}, doi = {10.1016/0303-2647(84)90004-2}, pmid = {6441609}, issn = {0303-2647}, mesh = {Age Factors ; Animals ; Aphids/*microbiology ; *Bacterial Proteins ; *Chaperonins ; *Gene Expression Regulation ; Protein Biosynthesis ; Rickettsiaceae/*genetics ; *Symbiosis ; }, abstract = {Aphid endosymbionts in vivo in young hosts synthesized almost exclusively only one protein, symbionin. The synthesis of symbionin declined with age of the host and instead the endosymbiont began to express some of its own genes which were expressed in vitro but were repressed in vivo in young host. A prolonged treatment of young host with cycloheximide brought about a physiological state similar to that in old insect. Though in the very old insect symbionin was no longer produced by its endosymbiont, the host seemed to depend almost entirely upon the gene products of the endosymbiont.}, }
@article {pmid6099426, year = {1984}, author = {Stewart, KD and Mattox, KR}, title = {The case for a polyphyletic origin of mitochondria: morphological and molecular comparisons.}, journal = {Journal of molecular evolution}, volume = {21}, number = {1}, pages = {54-57}, pmid = {6099426}, issn = {0022-2844}, mesh = {*Biological Evolution ; Cytochrome c Group/genetics ; Mitochondria/*ultrastructure ; *Models, Genetic ; Rhodospirillaceae/genetics/*ultrastructure ; }, abstract = {The comparative morphology and pigmentation of protists suggest that those with tubular mitochondrial cristae belong to a different lineage than those with lamellar cristae and that the evolutionary divergence might have been very early. We propose that the difference in cristal morphology is the result of separate origins of the mitochondria from endosymbionts related to the Rhodospirillaceae (purple nonsulfur bacteria) but differing in the morphology of their internal membranes. Comparisons of the cytochromes c of protists and the Rhodospirillaceae and of 16s rRNA T1 oligonucleotide catalogs in the Rhodospirillaceae do not contradict, and in fact provide support for, the idea. More extensive evidence may be lacking simply because cytochromes c have been studied in very few protists with tubular mitochondrial cristae.}, }
@article {pmid6413642, year = {1983}, author = {Soldo, AT and Brickson, SA and Larin, F}, title = {The size and structure of the DNA genome of symbiont xenosome particles in the ciliate Parauronema acutum.}, journal = {Journal of general microbiology}, volume = {129}, number = {5}, pages = {1317-1325}, doi = {10.1099/00221287-129-5-1317}, pmid = {6413642}, issn = {0022-1287}, mesh = {Animals ; Base Composition ; Centrifugation, Density Gradient ; Ciliophora/analysis/*genetics/ultrastructure ; DNA/*genetics/isolation &amp; purification ; Kinetics ; Molecular Weight ; Nucleic Acid Renaturation ; Symbiosis ; }, abstract = {The size and structure of the DNA genome of xenosomes, bacterial endosymbionts of the marine hymenostome ciliate, Parauronema acutum 110-3, were investigated. Renaturation kinetic measurements, determined optically and by hydroxyapatite chromatography, suggested a genome size of 0.34 x 10(9) daltons. Sedimentation rate measurements of DNA gently released from the symbionts yielded molecules of comparable size. The analytical complexity, determined chemically, was 3.03 x 10(9) daltons. Consistent with these and other data is a model for the structure of the symbiont genome in which the DNA exists in the form of nine circularly permuted, double-stranded DNA molecules of unique sequence, each of molecular weight 0.34 x 10(9). It is suggested that xenosomes and certain symbionts found in ciliated protozoa may be extant forms of once free-living bacteria that have adapted to the intracellular environment.}, }
@article {pmid6306706, year = {1983}, author = {Quackenbush, RL}, title = {Plasmids from bacterial endosymbionts of hump-killer paramecia.}, journal = {Plasmid}, volume = {9}, number = {3}, pages = {298-306}, doi = {10.1016/0147-619x(83)90007-0}, pmid = {6306706}, issn = {0147-619X}, mesh = {Animals ; Bacteria/*genetics ; Chromosome Mapping ; DNA Restriction Enzymes ; DNA, Bacterial/isolation &amp; purification ; Paramecium/*microbiology ; *Plasmids ; Symbiosis ; }, abstract = {Six isolates of Caedibacter taeniospiralis, collected from four continents, were screened for plasmid DNA. Plasmid DNA species containing between 41.5 and 49.5 kilobase pairs (kb) were observed in all strains. Physical maps of plasmids were constructed by determining relative positions of the restriction endonuclease (BamHI, SalI, XhoI, SacI, PstI, AvaI, and EcoRI) recognition sequences in each plasmid. The physical map of the smallest plasmid (41.5 kb), pKAP30, is reflected in each of the plasmids isolated from the other strains of C. taeniospiralis. Plasmid DNA from three of the isolates (strains 51 and 116 both from Indiana and strain 169 from Japan) each contain 43 kb, where 41.5 kb appear to be identical to pKAP30 (obtained from the Australian strain, A30). The extra 1.5 kb present in pKAP51, pKAP116, and pKAP169 is included as a single polynucleotide sequence. The 1.5-kb inclusion is located at apparently identical positions in pKAP116 and pKAP169 and at a totally different position in pKAP51. The two remaining plasmids, pKAP47 (from California strain 47) and pKAP298 (from Panama strain 298), both contain 49 kb to include a continuous 41.5-kb sequence that is apparently identical to pKAP30. The results indicate that the polynucleotide sequences of these plasmids are highly conserved and that the observed variations among them may be accounted for by transposable elements.}, }
@article {pmid6571998, year = {1983}, author = {Quackenbush, RL and Burbach, JA}, title = {Cloning and expression of DNA sequences associated with the killer trait of Paramecium tetraurelia stock 47.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {80}, number = {1}, pages = {250-254}, pmid = {6571998}, issn = {0027-8424}, mesh = {Bacteria/*genetics ; Cloning, Molecular ; DNA, Bacterial/*genetics ; Paramecium/*genetics ; *Plasmids ; Symbiosis ; }, abstract = {We have presented direct evidence that at least one of the traits associated with killing of paramecia by kappa particles is determined by an extrachromosomal genetic element. Plasmid DNA was isolated from Caedibacter taeniospiralis 47 (commonly known as 47 kappa), which is an obligate cytoplasmic endosymbiont of Paramecium tetraurelia. Fragments of pKAP47 DNA generated by Pst I digestion were inserted into pBR328 and then introduced into Escherichia coli 294 by transformation. Clones carrying recombinant plasmids were screened for toxicity toward sensitive strains of paramecia or for the ability to produce R bodies. None of the clones appeared to be toxic. However, three clones were found to have the ability to produce R bodies, which are proteinaceous ribbons (10-20 microns long, 0.5 microns wide, and 13 nm thick) rolled up inside the cell to form a hollow cylinder about 0.5 microns in diameter and 0.5 microns long. Each of these clones carry plasmids that contain the Pst I B fragment from pKAP47. Subclones of one of the recombinant plasmids, pBQ51, were constructed to determine the approximate location of DNA sequences necessary for R-body synthesis. The left-hand boundary of the required sequences was found to occur within a 600-base-pair region, and the location of the right-hand boundary was determined to occur within a 700-base-pair region. The minimum and maximum sizes of sequences required for R-body synthesis are between 1,300 and 2,600 base pairs.}, }
@article {pmid7117400, year = {1982}, author = {Schmidt, HJ}, title = {Isolation of Omikron-endosymbionts from mass cultures of Euplotes aediculatus and characterization of their DNA.}, journal = {Experimental cell research}, volume = {140}, number = {2}, pages = {417-425}, doi = {10.1016/0014-4827(82)90132-x}, pmid = {7117400}, issn = {0014-4827}, mesh = {Animals ; Bacteria/genetics/*isolation &amp; purification ; DNA, Bacterial/genetics/isolation &amp; purification ; Eukaryota/*microbiology ; *Symbiosis ; }, }
@article {pmid6806116, year = {1982}, author = {Alfieri, SC and Camargo, EP}, title = {Trypanosomatidae: isoleucine requirement and threonine deaminase in species with and without endosymbionts.}, journal = {Experimental parasitology}, volume = {53}, number = {3}, pages = {371-380}, doi = {10.1016/0014-4894(82)90080-7}, pmid = {6806116}, issn = {0014-4894}, mesh = {Animals ; Bacteria/enzymology ; *Bacterial Physiological Phenomena ; Crithidia/metabolism ; Eukaryota/metabolism/*microbiology ; Isoleucine/biosynthesis/*pharmacology ; Leishmania/metabolism ; Leucine/pharmacology ; *Symbiosis ; Threonine/pharmacology ; Threonine Dehydratase/*metabolism ; Trypanosoma cruzi/metabolism ; Valine/pharmacology ; }, }
@article {pmid6804254, year = {1982}, author = {Verni, F}, title = {Differential action of penicillin and uv-light on endosymbionts of the ciliate Euplotes crassus.}, journal = {Experientia}, volume = {38}, number = {3}, pages = {335-336}, pmid = {6804254}, issn = {0014-4754}, mesh = {Animals ; Bacteria/drug effects/*radiation effects ; Cell Division ; Ciliophora/*microbiology/physiology/ultrastructure ; Microscopy, Electron ; Penicillins/*pharmacology ; Symbiosis/drug effects/*radiation effects ; *Ultraviolet Rays ; }, }
@article {pmid6178009, year = {1982}, author = {Gray, MW and Doolittle, WF}, title = {Has the endosymbiont hypothesis been proven?.}, journal = {Microbiological reviews}, volume = {46}, number = {1}, pages = {1-42}, pmid = {6178009}, issn = {0146-0749}, mesh = {Amino Acid Sequence ; Bacteria/genetics ; Base Sequence ; *Biological Evolution ; *Cell Nucleus ; DNA ; Fungi/genetics ; Genes ; Genetic Code ; *Mitochondria ; *Plasmids ; Protein Biosynthesis ; Proteins ; RNA ; *Symbiosis ; Transcription, Genetic ; }, }
@article {pmid7120423, year = {1982}, author = {Harington, A and Thornley, AL}, title = {Biochemical and genetic consequences of gene transfer from endosymbiont to host genome.}, journal = {Journal of molecular evolution}, volume = {18}, number = {5}, pages = {287-292}, pmid = {7120423}, issn = {0022-2844}, mesh = {*Biological Evolution ; Chloroplasts/*physiology ; DNA, Mitochondrial/*genetics ; Gene Expression Regulation ; Genes ; Mitochondria/physiology ; Models, Biological ; Permeability ; Phagocytosis ; Proteins/genetics ; Recombination, Genetic ; *Symbiosis ; }, }
@article {pmid7024533, year = {1981}, author = {Freymuller, E and Camargo, EP}, title = {Ultrastructural differences between species of trypanosomatids with and without endosymbionts.}, journal = {The Journal of protozoology}, volume = {28}, number = {2}, pages = {175-182}, doi = {10.1111/j.1550-7408.1981.tb02829.x}, pmid = {7024533}, issn = {0022-3921}, mesh = {Animals ; Cell Nucleus/ultrastructure ; Crithidia/parasitology/*ultrastructure ; Eukaryota/microbiology/*ultrastructure ; Flagella/ultrastructure ; Microscopy, Electron ; Mitochondria/ultrastructure ; Organoids/ultrastructure ; *Symbiosis ; Trypanosoma cruzi/microbiology/*ultrastructure ; }, abstract = {Species of trypanosomatids without endosymbionts (Leptomonas seymouri, L. collosoma, L. samueli, crithidia fasciculata, C. luciliae, C. acanthocephali, Herpetomonas megaseliae, H. mariadeanei, H. samuelpessoai, H. muscarum muscarum, Trypanosoma cruzi) and species of trypanosomatids with endosymbionts (Crithidia deanei, C. oncopelti, Blastocrithidia culicis) were comparatively studied by means of electron microscopy. Artificially aposymbiotic strains derived from species with symbiont were also included in the survey. Species with symbiont were found to differ in some ultrastructural aspects from the group of species without symbiont. Paraxial rods of flagella or intraflagellar structure were found exclusively in species without symbiont. Peripheral branching of mitochondria, accompanied by absence of subpellicular microtubules in sites where the mitochondrial branches are appressed to the cell membrane, were found exclusively in species with symbiont. Networks of kinetoplast DNA fibrils were found to be larger and looser in species with symbiont. Symbiont-free strains of species with symbiont retained the same morphological characteristics of their parental species.}, }
@article {pmid7265265, year = {1981}, author = {Weeden, NF}, title = {Genetic and biochemical implications of the endosymbiotic origin of the chloroplast.}, journal = {Journal of molecular evolution}, volume = {17}, number = {3}, pages = {133-139}, pmid = {7265265}, issn = {0022-2844}, support = {5 T32 GMO7467/GM/NIGMS NIH HHS/United States ; }, mesh = {Amino Acids/biosynthesis ; Aminolevulinic Acid/metabolism ; *Biological Evolution ; Carbohydrate Metabolism ; Chloroplasts/*metabolism ; Genes ; Glycolysis ; Photosynthesis ; Plants/metabolism ; }, abstract = {The hypothesis stating that chloroplasts were derived from a photosynthetic procaryote is explored at a genetic and biochemical level. A transfer of genetic material from the endosymbiont to the nucleus of the host cell is proposed along with a corollary argument that the protein products of such transferred genes have remained specific to the chloroplast. This model provides an explanation for the presence of plastid-specific isozymes which are coded by nuclear DNA. It also suggests that the genome of the endosymbiont contributed the information necessary for the biosynthesis of carotenoids and the "essential" amino acids and the assimilation of nitrate-nitrogen and sulfate-sulfur. Animal cells lack these capabilities not because such were lost subsequent to the divergence of the plant and animal lines, but because animal cells did not become host to the appropriate symbionts. Additional implications of this thesis are discussed.}, }
@article {pmid7011067, year = {1981}, author = {Tesh, RB and Cornet, M}, title = {The location of San Angelo virus in developing ovaries of transovarially infected Aedes albopictus mosquitoes as revealed by fluorescent antibody technique.}, journal = {The American journal of tropical medicine and hygiene}, volume = {30}, number = {1}, pages = {212-218}, doi = {10.4269/ajtmh.1981.30.212}, pmid = {7011067}, issn = {0002-9637}, support = {N01 AI 82560/AI/NIAID NIH HHS/United States ; }, mesh = {Aedes/*microbiology ; Animals ; Antigens, Viral/analysis ; Bunyaviridae/*isolation &amp; purification ; Encephalitis Virus, California/growth &amp; development/*isolation &amp; purification ; Female ; Fluorescent Antibody Technique ; Ovary/microbiology ; }, abstract = {Aedes albopictus adult female mosquitoes, transovarially infected with San Angelo (SA) virus, were examined by fluorescent antibody technique during various stages of ovarian development to determine how the virus enters the egg. Upon emergence from the day of adulthood, it was visible in the follicular epithelium, oocytes and nurse cells of the primary follicles. In the 72-hour period between the ingestion of blood and oviposition, there was a marked increase in the amount of viral antigen in the oocyte, indicating rapid virus accumulation. After oviposition, SA viral antigen was also seen in the secondary ovarian follicles. The observed sequence of infection of the mosquito ovariole with SA virus is analogous to that described with certain endosymbionts of insects.}, }
@article {pmid6941730, year = {1981}, author = {Levandowsky, M}, title = {Endosymbionts, biogenic amines, and a heterodyne hypothesis for circadian rhythms.}, journal = {Annals of the New York Academy of Sciences}, volume = {361}, number = {}, pages = {369-375}, doi = {10.1111/j.1749-6632.1981.tb46532.x}, pmid = {6941730}, issn = {0077-8923}, support = {FR-05596//PHS HHS/United States ; }, mesh = {Biogenic Amines/*metabolism ; Biological Clocks ; *Cells/metabolism ; *Circadian Rhythm ; *Eukaryotic Cells/metabolism ; *Symbiosis ; }, }
@article {pmid6175358, year = {1981}, author = {Rizzo, PJ}, title = {Comparative aspects of basic chromatin proteins in dinoflagellates.}, journal = {Bio Systems}, volume = {14}, number = {3-4}, pages = {433-443}, doi = {10.1016/0303-2647(81)90048-4}, pmid = {6175358}, issn = {0303-2647}, mesh = {Animals ; Cell Nucleus/analysis ; Chromatin/*analysis/ultrastructure ; Dinoflagellida/*analysis ; Histones/analysis ; Microscopy, Electron ; Nucleoproteins/*analysis ; Species Specificity ; Staining and Labeling ; }, abstract = {Previous work on histone-like proteins in dinoflagellates is summarized, together with some new data to give an overview of basic proteins in these algae. The first two dinoflagellates studied were both found to contain one major acid-soluble protein that migrated to the same position in acidic-urea gels. When several other genera were studied however, it became apparent that the histone-like proteins from different dinoflagellates were similar but not identical. In view of the great diversity of living dinoflagellates it is speculated that further differences in dinoflagellate basic chromatin proteins will be revealed. Electrophoretic data from the eukaryotic (endosymbiont) nucleus of Peridinium balticum showed the presence of five major components. It is speculated that two of these proteins represent an H1-like doublet and two others correspond to the highly conserved histones H3 and H4. The fifth component is a new histone that may substitute for H2A and H2B in the nucleosome. Because histones and nucleosomes are present in all higher organisms but completely lacking in procaryotes, studies on basic proteins in dinoflagellates will provides insights into the evolution of histones and eucaryotic chromatin organization.}, }
@article {pmid7412621, year = {1980}, author = {Suetin, SO and Pariĭskaia, AN and Kalakutskiĭ, LV}, title = {[Electron microscopic study of the developmental cycle of an actinomycete endosymbiont in the nitrogen-fixing nodules on the roots of Alnus glutinosa].}, journal = {Mikrobiologiia}, volume = {49}, number = {4}, pages = {604-607}, pmid = {7412621}, issn = {0026-3656}, mesh = {Actinomycetales/growth &amp; development/*ultrastructure ; Ecology ; *Microscopy, Electron ; *Nitrogen Fixation ; *Symbiosis ; *Trees ; }, abstract = {As has been shown by electron microscopy, the development of the endosymbiont in the nitrogen-fixing nodules of A. glutinosa proceeds either along the known (hyphae leads to vesicles) or less convenient pattern (hyphae leads to sporangia leads to spores). The paper presents more complete information about the structure of layers which separate the endosymbiont from the cytoplasm of host cells and about changes in the structure of the both partners accompanying sporogenesis.}, }
@article {pmid6457239, year = {1980}, author = {Seckbach, J and Fredrick, JF}, title = {A primaeval alga bridging the blue-green and the red algae: further biochemical and ultrastructure studies of Cyanidium caldarium with special reference to the plastid membranes.}, journal = {Microbios}, volume = {29}, number = {117-118}, pages = {135-147}, pmid = {6457239}, issn = {0026-2633}, mesh = {Chlorella/metabolism/ultrastructure ; Chloroplasts/ultrastructure ; Cyanobacteria/metabolism/ultrastructure ; Glucans/metabolism ; Glucosyltransferases/metabolism ; *Phylogeny ; Rhodophyta/*classification/metabolism/ultrastructure ; }, abstract = {The storage polyglucan and isozyme distribution together with the fine structure of the chloroplasts have been investigated in Cyanidium caldarium. This alga is a unicellular eukaryote which thrives in acid hot habitats. Our observations propose C. caldarium as a primitive Rhodophytan which is the "bridge" alga linking the prokaryotic blue-green and the red algae. some features of the Cyanidium chloroplast e.g. the single membrane enveloping the plastid, or the cyanobacterial nature of its thylakoids and other cellular characteristics, point to the primaeval status of this early-evolved eukaryote which is considered a "living fossil". It seems to be the true transitional organism between the anucleated and nucleated algae and is unlikely to be an endosymbiontic association of two or more cells, as speculated elsewhere.}, }
@article {pmid43084, year = {1979}, author = {Wink, M}, title = {The endosymbionts of Glossina morsitans and G. palpalis: cultivation experiments and some physiological properties.}, journal = {Acta tropica}, volume = {36}, number = {3}, pages = {215-222}, pmid = {43084}, issn = {0001-706X}, mesh = {Animals ; Antimycin A/pharmacology ; Bacteria/growth &amp; development/metabolism ; *Bacterial Physiological Phenomena ; Culture Media ; Culture Techniques ; Intestines/microbiology ; Malates/metabolism ; Oxygen Consumption/drug effects ; Pyruvates/metabolism ; Rotenone/pharmacology ; Succinates/metabolism ; Symbiosis ; Tsetse Flies/*microbiology ; }, abstract = {Pyruvate, malate, and succinate are the main substrates for bacteroid respiration; oxygen uptake can be inhibited by rotenone and antimycin A, but not by cyanide. The symbionts displayed limited growth and survival for over 80 days in a medium with succinate and pyruvate as main substrates, and supplemented with nucleotides. It was not possible to cultivate the endosymbionts of G. morsitans and G. palpalis intracellularly in cell cultures of the tsetse fly or of vertebrates. A high attraction between cells and symbionts was observed in these systems; about 10% of all bacteroids were incorporatedby the cells but they were lysed and digested within 48 h.}, }
@article {pmid479640, year = {1979}, author = {Nemanic, PC and Owen, RL and Stevens, DP and Mueller, JC}, title = {Ultrastructural observations on giardiasis in a mouse model. II. Endosymbiosis and organelle distribution in Giardia muris and Giardia lamblia.}, journal = {The Journal of infectious diseases}, volume = {140}, number = {2}, pages = {222-228}, doi = {10.1093/infdis/140.2.222}, pmid = {479640}, issn = {0022-1899}, mesh = {Animals ; Female ; Giardia/growth &amp; development/*microbiology/ultrastructure ; Giardiasis/parasitology/*pathology ; Humans ; Jejunum/parasitology/ultrastructure ; Mice ; Organoids/ultrastructure ; Symbiosis ; }, abstract = {Ultrastructural observations of Giardia muris in a mouse model revealed endosymbiotic microbes not previously reported in Giardia. Endosymbionts 240--360 nm wide, 600--1,400 nm long, and with an internal structure similar to that of bacilli were not seen entering Giardia but were found and appeared to divide within Giardia. No evidence was found of digestion of the endosymbionts by the giardia host in either the trophozoite or the cyst form. Endosymbionts were concentrated centrally around the nuclear area and were uncommon in peripheral feeding regions. The same cellular organelles seen in G. muris were found in Giardia lamblia from human jejunal biopsy material, but no endosymbionts were identified in G. lamblia trophozoites from the seven patients examined. Endosymbionts within Giardia may be found to alter trophozoite pathogenicity, metabolism, range of infectivity, antigenic surface characteristics, and host specificity, as they do in other protozoa.}, }
@article {pmid36627, year = {1979}, author = {Taylor, FJ}, title = {Symbionticism revisited: a discussion of the evolutionary impact of intracellular symbioses.}, journal = {Proceedings of the Royal Society of London. Series B, Biological sciences}, volume = {204}, number = {1155}, pages = {267-286}, doi = {10.1098/rspb.1979.0027}, pmid = {36627}, issn = {0950-1193}, mesh = {Animals ; Bacterial Physiological Phenomena ; *Biological Evolution ; Chloroplasts/physiology ; DNA/metabolism ; Dinoflagellida/physiology ; Mitochondria/physiology ; Photosynthesis ; Protein Biosynthesis ; RNA/metabolism ; Species Specificity ; *Symbiosis ; Transcription, Genetic ; }, abstract = {Wallin (1927) first published the notion that the fusion of bacteria with host cells was the principal source of genetic novelty for speciation. He suggested that mitochondria are transitional elements in this process. While the significance that he attributed to symbiosis now seem excessive, he was one of the first authors to be aware of the evolutionary potential of symbiotic events and his view of mitochondria may not seem strange to many cell biologist today. The most significant evolutionary development which has been attributed to intracellular symbiosis is the origin of eukaryotic cellular organization. The current status of the 'serial endosymbiosis hypothesis' is briefly review. The case for the symbiotic origin of the chloroplast, based principally on 16 S RNA oligonucleotide cataloguing, is very strong. Mitochondrial origins are more obscure but also appear to be symbiotic due to recent 18 S cataloguing from wheat embryos. The probablility of the multiple origin of some eukaryotic organelles is also examined, the processes in question being the acquisition of distinct stocks of chloroplasts from disparate photosynthetic prokaryotes and the secondary donation of organelles from degenerate eukaryotic endosymbionts to their hosts, with specific reference to the dinoflagellates Peridinium balticum, Kryptoperidinium foliaceum and the ciliate Mesodinium rubrum. It is concluded that the evolutionary potential of intracellular symbiosis ('cytobiosis': a term introduced in this paper) is great, with the best established influence being on the origin of eukaryotic chloroplasts. Together with the potential effects of viral vectors, symbiosis serves as a supplementary speciation mechanism capable of producing directed evolutionary changes. It is likely that these processes will explain some of the apparent anomalies in evolutionary rates and direction which are not readily explicable by the conventional synthetic theory of evolution.}, }
@article {pmid36618, year = {1979}, author = {Muscatine, L and Pool, RR}, title = {Regulation of numbers of intracellular algae.}, journal = {Proceedings of the Royal Society of London. Series B, Biological sciences}, volume = {204}, number = {1155}, pages = {131-139}, doi = {10.1098/rspb.1979.0018}, pmid = {36618}, issn = {0950-1193}, mesh = {Animals ; Cnidaria/parasitology ; Eukaryota/*growth &amp; development/physiology ; Kinetics ; Light ; Species Specificity ; }, abstract = {Members of three classes of unicellular algae have exploited an intracellular habitat and occur as endosymbionts in aquatic invertebrates, including Protozoa. Such associations manifest a range of host--symbiont cellular interactions and achieve stability through the regulation of symbiont numbers. The mechanism of regulation is poorly understood. Steady-state algae:host cell ratios might be achieved by expulsion, digestion, or inhibition of growth of algal symbionts. Digestion and expulsion have been observed directly in some associations but their role in regulating numbers is circumstantial. Inhibition of growth as a result of nutrient limitation or inhibitor secretion is an attractive, but inadequately tested, hypothesis. The relation between the host cell mitosis and algal proliferation is a potential focal point for further study.}, }
@article {pmid118849, year = {1979}, author = {Schwemmler, W and Herrmann, M}, title = {[Oscillations in the energy metabolism of the host and symbiont of a cicada. I. Analysis of possible metabolic and physiologic correlations of both systems].}, journal = {Cytobios}, volume = {25}, number = {97}, pages = {45-62}, pmid = {118849}, issn = {0011-4529}, mesh = {Adenine Nucleotides/*metabolism ; Adenosine Diphosphate/metabolism ; Adenosine Monophosphate/metabolism ; Adenosine Triphosphate/metabolism ; Animals ; Energy Metabolism ; Female ; Grasshoppers/metabolism/*microbiology ; Ovum/metabolism/microbiology ; Rickettsiaceae/*metabolism ; }, abstract = {The insect group which includes cicadas harbours intracellular bacterial symbionts which are passed on from generation to generation in the form of a 'symbiont ball' inserted between the egg membrane and the rear pole of the egg cell. Bioluminiscence methods can be used to measure the oscillations in ATP, ADP and AMP levels in egg systems which have been separated into a host and a symbiont part (Euscelidius variegatus, Euscelis incisus), and which are exposed to constant light or light-dark variations under otherwise constant conditions (26 degrees C, 70% relative humidity, 7000 lux). The energy charge can be calculated from the ATP, ADP and AMP concentrations. Comparisons of such curves suggest an 'antagonistic' relationship in the energy metabolism of the host and symbiont parts of the egg. The minima of oscilaltions in the host's energy metabolism generally occur at the same time as the maxima in the endocytobionts energy metabolism. Antagonistic correlations between the nucleus/cytoplasm and mitochondria/plastids were also observed in the eucyte system. Analogies between the two systems can be explained satisfactorily by the endosymbiont theory of the origin of eucytes. It follows that insect endocytobioses can serve as an experimental model for the biochemical analysis of the eucyte system.}, }
@article {pmid592424, year = {1977}, author = {Woese, CR}, title = {Endosymbionts and mitochondrial origins.}, journal = {Journal of molecular evolution}, volume = {10}, number = {2}, pages = {93-96}, pmid = {592424}, issn = {0022-2844}, mesh = {*Biological Evolution ; Chloroplasts ; DNA, Mitochondrial/genetics ; Genes ; *Mitochondria ; Oxygen Consumption ; *Symbiosis ; }, abstract = {The possibility is put forth that the mitochondrion did not originate from an endosymbiosis, 1-2 billion years ago, involving an aerobic bacterium. Rather, it arose by endosymbiosis in a much early, anaerobic period, and was initially a photosynthetic organelle, analogous to the modern chloroplast. This suggestion arises from a reconsideration of the nature of endosymbiosis. It explains the remarkable diversity in mitochondrial information storage and processing systems.}, }
@article {pmid927516, year = {1977}, author = {Camargo, EP and Freymuller, E}, title = {Endosymbiont as supplier of ornithine carbamoyltransferase in a trypanosomatid.}, journal = {Nature}, volume = {270}, number = {5632}, pages = {52-53}, doi = {10.1038/270052a0}, pmid = {927516}, issn = {0028-0836}, mesh = {Animals ; Eukaryota/enzymology/*microbiology ; Ornithine Carbamoyltransferase/*metabolism ; *Symbiosis ; }, }
@article {pmid838692, year = {1977}, author = {Quackenbush, RL}, title = {Phylogenetic relationships of bacterial endosymbionts of Paramecium aurelia: polynucleotide sequence relationships of 51 kappa and its mutants.}, journal = {Journal of bacteriology}, volume = {129}, number = {2}, pages = {895-900}, pmid = {838692}, issn = {0021-9193}, mesh = {Animals ; Bacteria/*analysis ; Base Sequence ; Cytosine/analysis ; DNA, Bacterial/*analysis ; Guanine/analysis ; Molecular Weight ; Mutation ; Nucleic Acid Conformation ; Paramecium/*microbiology ; Phylogeny ; Polynucleotides/*analysis ; Symbiosis ; }, abstract = {Hydroxyapatite chromatographic procedures were used to investigate the deoxyribonucleic acid (DNA) sequence relationships of kappa of Paramecium tetraurelia stock 51 and the organisms that have been designated as mutants of 51 kappa. Of the "mutants" studied, only 51m43 kappa possessed a high percentage (89%) of DNA sequences homologous to those of 51 kappa. All other "mutant" strains possessed less than 25% polynucleotide sequence homology to 51 kappa DNA. The three strains of pi endosymbionts (51m1 pi, 51m43 pi, and 139 pi) share greater than 75% DNA sequence homology with each other and approximately 50% DNA sequence homology with 138 mu, the mate-killer endosymbiont found in P. octaurelia. Only 23% of the 51 kappa DNA sequences were found to be homologous with those of 51m1 kappa. The data indicate that of the "mutants" studied, only 51m43 kappa could be a mutant of 51 kappa. The pi endosymbionts comprise a closely related group of organisms that are also related to 138 mu but not to any of the kappas tested. The group of organisms designated as kappa appears to be comprised of at least two distinct phylogenetic groups.}, }
@article {pmid838691, year = {1977}, author = {Dilts, JA}, title = {Chromosomal and extrachromosomal deoxyribonucleic acid from four bacterial endosymbionts derived from stock 51 of Paramecium tetraurelia.}, journal = {Journal of bacteriology}, volume = {129}, number = {2}, pages = {888-894}, pmid = {838691}, issn = {0021-9193}, mesh = {Animals ; Bacteria/*analysis/growth &amp; development/ultrastructure ; Chromosomes, Bacterial/*analysis ; DNA, Bacterial/*analysis ; DNA, Circular/*analysis ; *Extrachromosomal Inheritance ; Genetic Variation ; Molecular Weight ; Paramecium/growth &amp; development/*microbiology ; *Plasmids ; Symbiosis ; }, abstract = {Four variant lines of stock 51 kappa (Paramecium tetraurelia) were screened for the presence of covalently closed circular (CCC) deoxyribonucleic acid (DNA). Stock 51m43 kappa, a nonkiller resistant to 51 killing, contained four classes of CCC DNA: 2.9 X 10(7), 9.7 X 10(7), and 11.8 X 10(7) daltons. The buoyant densities of 51m43 kappa chromosomal and CCC DNA were 1.700 and 1.698 g/cm3, respectively. Stock 51m43 pi, a sensitive nonkiller, contained two CCC species: 0.3 X 10(7) and 4.4 X 10(7) daltons. The buoyant densities of both the chromosomal and CCC DNA were 1.694 to 1.695 g/cm3. Three sizes of CCC DNA were found in 51m1 pi: 0.3 X 10(7), 2.3 X 10(7), and 4.5 X 10(7) daltons. The buoyant densities of both the chromosoaml DNA and the CC DNA were 1.694 to 1.695 g/cm3. It is not known whether 51m1 kappa, a sensitive spinner killer, contains CCC DNA. The buoyant density of its chromosomal DNA was 1.703 g/cm3. Of the four variant lines, only 51m43 kappa appears to be a mutant of 51 kappa. The chromosomal and CCC DNAs of 51m43 kappa have the same buoyant densities as those of 51 kappa; in addition 51m43 kappa contain a CCC molecule the same size as that found in 51 kappa (2.8 x 10(7) daltons). The three other lines are probably bacterial species that are distinct from 51 kappa and which, at one time, were co-inhabitants with 51 kappa in stock 51 paramecia.}, }
@article {pmid987836, year = {1976}, author = {Bismanis, JE}, title = {Endosymbionts of Sitodrepa panicea.}, journal = {Canadian journal of microbiology}, volume = {22}, number = {10}, pages = {1415-1424}, doi = {10.1139/m76-210}, pmid = {987836}, issn = {0008-4166}, mesh = {Animals ; *Candida/classification/growth &amp; development/metabolism ; Carbohydrate Metabolism ; Coleoptera/*microbiology ; Nitrogen/metabolism ; Symbiosis ; Vitamins/metabolism ; }, abstract = {Morphological and physiological characteristics of seven strains of yeast-like symbionts isolated from Sitodrepa panicea justify their inclusion into the genus Torulopsis as a new species: T. buchnerii. The symbiotic relationship is mutually beneficial: the symbionts obtain some nitrogenous compounds and carbohydrates, such as proline and trehalose from the host's hemolymph, and synthesize and make available to the host all the essential amino acids and vitamins, except biotin.}, }
@article {pmid972171, year = {1976}, author = {Jeon, KW and Jeon, MS}, title = {Endosymbiosis in amoebae: recently established endosymbionts have become required cytoplasmic components.}, journal = {Journal of cellular physiology}, volume = {89}, number = {2}, pages = {337-344}, doi = {10.1002/jcp.1040890216}, pmid = {972171}, issn = {0021-9541}, mesh = {Acid Phosphatase/metabolism ; Amoeba/enzymology/*growth &amp; development/ultrastructure ; Animals ; Bacteria ; Nuclear Transfer Techniques ; Species Specificity ; *Symbiosis ; }, abstract = {A strain of large, free-living amoeba that became dependent on bacterial endosymbionts which had infected the amoebae initially as intracellular parasites, was studied by micrurgy and electron microscopy. The results show that the infected host cells require the presence of live endosymbionts for their survival.Thus, the nucleus of an infected amoeba can form a viable cell with the cytoplasm of a noninfected amoeba only when live endosymbionts are present. The endosymbiotic bacteria are not digested by the host amoebae and are not themselves used as nutritional supplement. While the host amoebae are dependent specifically on the endosymbionts, the latter can live inside amoebae of different strains, indicating that their dependence on the host cells is not yet strain specific.}, }
@article {pmid828338, year = {1976}, author = {Harrison, DN and Dorsey, CH and Brown, CA}, title = {Studies on a macronuclear endosymbiont of Spirostomum ambiguum. II. Ultrastructural comparison of the in situ and the cultivated endosymbiont.}, journal = {Transactions of the American Microscopical Society}, volume = {95}, number = {4}, pages = {565-568}, pmid = {828338}, issn = {0003-0023}, mesh = {Bacteria/*ultrastructure ; Cell Membrane/ultrastructure ; Cell Nucleus/microbiology ; Ciliophora/*microbiology ; Symbiosis ; }, }
@article {pmid828337, year = {1976}, author = {Harrison, DN and Dorsey, CH and Finley, HE}, title = {Studies on a macronuclear endosymbiont of Spirostomum ambiguum. I. Isolation of the microorganism from the macronucleus.}, journal = {Transactions of the American Microscopical Society}, volume = {95}, number = {4}, pages = {560-564}, pmid = {828337}, issn = {0003-0023}, mesh = {Animals ; Bacteria/classification/*isolation &amp; purification ; Cell Nucleus/microbiology ; Ciliophora/*microbiology ; Symbiosis ; }, }
@article {pmid987046, year = {1976}, author = {Tippit, DH and Pickett-Heaps, JD}, title = {Apparent amitosis in the binucleate dinoflagellate Peridinium balticum.}, journal = {Journal of cell science}, volume = {21}, number = {2}, pages = {273-289}, doi = {10.1242/jcs.21.2.273}, pmid = {987046}, issn = {0021-9533}, mesh = {Cell Division ; Cell Nucleolus/ultrastructure ; Cell Nucleus/*ultrastructure ; Chromosomes/ultrastructure ; Dinoflagellida/*ultrastructure ; Eukaryota/*ultrastructure ; Microtubules/ultrastructure ; *Mitosis ; }, abstract = {Mitosis and cytokinesis in the free-living binucleate dinoflagellate Peridinium balticum are described, P. balticum contains 2 nuclei; one is a typical dinoflagellate nucleus and the other resembles the interphase nuclei of some eucaryotic cells and is here named the supernumerary nucleus (formerly called the eucaryotic nucleus). The dinoflagellate nucleus divides in the characteristic manner already described for certain other dinoflagellates. The supernumerary nucleus does not undergo normal mitosis; its chromatin does not condense, a spindle is not differentiated for its division, nor are any microtubules present inside the nucleus during any stage of its division. Instead the supernumerary nucleus divides by simple cleavage, which is concurrent with cytoplasmic cleavage. The nucleus cleaves first on its side facing the wall, but later it cleaves circumferentially as the cytoplasmic cleavage furrow draws closer. Invariably at late cytokinesis, a portion of the dividing nucleus passes through the only remaining uncleaved area of the cell. The final separation of the supernumerary nucleus is probably accomplished by the ingrowing furrow pinching the nucleus in two. There is no apparent precise segregation of genetic material during division, nor are there any structural changes inside the dividing nucleus which distinguish it from the interphase nucleus. Certain aspects of amitosis, and previously postulated theories concerning the endosymbiont origin of the second nucleus, are discussed.}, }
@article {pmid178679, year = {1976}, author = {Pardy, RL}, title = {The morphology of green hydra endosymbionts as influenced by host strain and host environment.}, journal = {Journal of cell science}, volume = {20}, number = {3}, pages = {655-669}, doi = {10.1242/jcs.20.3.655}, pmid = {178679}, issn = {0021-9533}, mesh = {Chlorophyta/*ultrastructure ; Chloroplasts/ultrastructure ; Darkness ; Fasting ; Hydra/*physiology ; Inclusion Bodies/ultrastructure ; Organoids/ultrastructure ; Species Specificity ; Starch ; *Symbiosis ; }, abstract = {The ultrastructure of Chlorella-like algal endosymbionts from the Florida and English strains of green hydra was compared under different host feeding and photoperiodic regimes. Under standard conditions (host fed daily, 12-h photoperiod) the algae from the 2 strains exhibited considerable differences. The English symbionts had a pyrenoid, compact chloroplast membranes and vesiculated polyphosphate bodies. By comparison, Florida symbionts lacked a pyrenoid, had chloroplasts with less compact membranes and exhibited spherical polyphosphate bodies. When maintained in the dark, algae from English hydra lost their pyrenoids, showed great compaction of the chloroplast and developed large, shield-shaped, electron-dense bodies. In contrast, algae from Florida hosts did not exhibit gross ultrastructural modification. Reciprocal cross-transfers of symbionts were made by placing Florida algae in English aposymbiotic (algal-free) hosts and vice versa. After residence in Florida hosts, English symbionts appeared to undergo ultrastructural modifications resulting in a morphology indistinguishable from the native Florida symbionts. Florida algae showed no modifications resulting from residence in English hosts. It thus appears that the English symbiont has great morphological plasticity, as its structure is greatly modified depending upon the host in which it resides and the conditions under which the host is maintained. The results of these studies are discussed and compared with published accounts of free-living Chlorella and with reports dealing with other Chlorella symbionts.}, }
@article {pmid1278680, year = {1976}, author = {Dilts, JA}, title = {Covalently closed, circular DNA in kappa endosymbionts of Paramecium.}, journal = {Genetical research}, volume = {27}, number = {2}, pages = {161-170}, doi = {10.1017/s0016672300016360}, pmid = {1278680}, mesh = {Animals ; *Bacteria ; Centrifugation, Density Gradient ; DNA, Bacterial/*analysis ; DNA, Circular/*analysis ; Microscopy, Electron ; Nucleic Acid Conformation ; *Paramecium ; Phenotype ; Symbiosis ; }, }
@article {pmid1099218, year = {1975}, author = {Reijnders, L}, title = {The origin of mitochondria.}, journal = {Journal of molecular evolution}, volume = {5}, number = {3}, pages = {167-176}, pmid = {1099218}, issn = {0022-2844}, mesh = {Bacteria/ultrastructure ; *Biological Evolution ; Cell Nucleus/metabolism ; DNA/metabolism ; DNA, Mitochondrial/metabolism ; Genes ; *Mitochondria/metabolism ; Models, Biological ; Plasmids ; Symbiosis ; }, abstract = {The endosymbiont and episome theories about the origin of mitochondria are reviewed. Biochemical and genetic data, relevant to these theories are discussed. An alternative theory is also proposed; this theory is that nuclear and mitochondrial DNAs developed from compartmentalized duplicate prokaryote DNAs.}, }
@article {pmid806081, year = {1975}, author = {Zablen, LB and Kissil, MS and Woese, CR and Buetow, DE}, title = {Phylogenetic origin of the chloroplast and prokaryotic nature of its ribosomal RNA.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {72}, number = {6}, pages = {2418-2422}, pmid = {806081}, issn = {0027-8424}, mesh = {Base Sequence ; *Biological Evolution ; Chloroplasts/*analysis ; Coliphages/enzymology ; Electrophoresis, Polyacrylamide Gel ; Euglena gracilis/*analysis/ultrastructure ; Oligonucleotides/analysis/isolation &amp; purification ; RNA, Ribosomal/*analysis ; Ribonucleases ; Species Specificity ; }, abstract = {The 16S ribosomal RNA of the Euglena gracilis chloroplast has been characterized in terms of its two-dimensional electrophoretic "fingerprint" (T1 ribonuclease). Results show it to be a typically prokaryotic 16 S rRNA. By the present criterion, different chloroplasts are shown to be related to one another and at least distantly to blue-green algae and perhaps to Bacillaceae. These results argue in favor of an endosymbiont origin of the chloroplast.}, }
@article {pmid803475, year = {1975}, author = {Proca-Ciobanu, M and Lupascu, GH and Petrovici, Al and Ionescu, MD}, title = {Electron microscopic study of a pathogenic Acanthamoeba castellani strain: the presence of bacterial endosymbionts.}, journal = {International journal for parasitology}, volume = {5}, number = {1}, pages = {49-56}, doi = {10.1016/0020-7519(75)90097-1}, pmid = {803475}, issn = {0020-7519}, mesh = {Amoeba/growth &amp; development/*ultrastructure ; Cell Nucleus/ultrastructure ; Cytoplasmic Granules/ultrastructure ; Endoplasmic Reticulum/ultrastructure ; Golgi Apparatus/ultrastructure ; Microscopy, Electron ; Mitochondria/ultrastructure ; Rickettsiaceae/*ultrastructure ; }, }
@article {pmid1118907, year = {1975}, author = {Osipov, DV and Skoblo, II and Rautian, MS}, title = {[Symbiotic bacteria of the macronucleus of Paramecium caudatum].}, journal = {Tsitologiia}, volume = {17}, number = {1}, pages = {95-98}, pmid = {1118907}, issn = {0041-3771}, mesh = {Animals ; Bacteria/*isolation &amp; purification ; Paramecium/*microbiology ; Symbiosis ; }, abstract = {Particles of a newly described endosymbiont of Paramecium caudatum, clone M-115, here referred to as iota--particles, are Gram--negative bacteria. The symbionts are only present within macronuclei and not in the cytoplasm or in the micronuclei. The cells of clone M-115 iota do not display any killer-effect when mixed with "clean" cultures of Paramecia. In life cycle of the symbiont, there is an alternation of two morphological forms: a spindle-shaped form 2.0--2.5 microns long and a rod-shaped form -- about 18 microns long. The data obtained revealed a high ability to infect cell of "clean" clones of P. caudatum with iota-particles. The antagonistic relationships between two different species of endonucleosymbionts: iota- and omega-particles, are detected. The revealed biological features of iota can be used for studying the mechanisms of nuclear differentiation in ciliates.}, }
@article {pmid785667, year = {1975}, author = {Chang, KP}, title = {Haematophagous insect and haemoflagellate as hosts for prokaryotic endosymbionts.}, journal = {Symposia of the Society for Experimental Biology}, volume = {}, number = {29}, pages = {407-428}, pmid = {785667}, issn = {0081-1386}, mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Bacteria/drug effects/ultrastructure ; Bedbugs/metabolism/*microbiology ; Cell Division ; Eukaryota/growth &amp; development/metabolism/*microbiology ; Heme/biosynthesis ; Lysosomes/metabolism ; Porphyrins/biosynthesis ; Rickettsia/metabolism ; Spheroplasts/drug effects ; *Symbiosis ; Temperature ; }, }
@article {pmid4278787, year = {1974}, author = {Mundim, MH and Roitman, I and Hermans, MA and Kitajima, EW}, title = {Simple nutrition of Crithidia deanei, a reduviid trypanosomatid with an endosymbiont.}, journal = {The Journal of protozoology}, volume = {21}, number = {4}, pages = {518-521}, doi = {10.1111/j.1550-7408.1974.tb03691.x}, pmid = {4278787}, issn = {0022-3921}, mesh = {Biotin/metabolism ; Culture Media ; Eukaryota/growth &amp; development/isolation &amp; purification/*metabolism/microbiology/ultrastructure ; Folic Acid/metabolism ; Fructose/metabolism ; Glucose/metabolism ; Hemiptera/*parasitology ; Mannose/metabolism ; Methionine/metabolism ; Niacinamide/metabolism ; Rickettsiaceae/*isolation &amp; purification ; Sucrose/metabolism ; Thiamine/metabolism ; Tyrosine/metabolism ; }, }
@article {pmid4845245, year = {1974}, author = {Pardy, RL}, title = {Some factors affecting the growth and distribution of the algal endosymbionts of Hydraviridis.}, journal = {The Biological bulletin}, volume = {147}, number = {1}, pages = {105-118}, doi = {10.2307/1540572}, pmid = {4845245}, issn = {0006-3185}, mesh = {Animals ; Eukaryota/*growth &amp; development ; Hydra/*growth &amp; development ; *Symbiosis ; }, }
@article {pmid4211983, year = {1974}, author = {Schwemmler, W}, title = {Endosymbionts: factors on egg pattern formation.}, journal = {Journal of insect physiology}, volume = {20}, number = {8}, pages = {1467-1474}, doi = {10.1016/0022-1910(74)90078-x}, pmid = {4211983}, issn = {0022-1910}, mesh = {Animals ; Ecology ; Female ; Insecta/*growth &amp; development ; Ovum/growth &amp; development ; *Rickettsiaceae ; }, }
@article {pmid4599970, year = {1974}, author = {Preer, JR and Preer, LB and Jurand, A}, title = {Kappa and other endosymbionts in Paramecium aurelia.}, journal = {Bacteriological reviews}, volume = {38}, number = {2}, pages = {113-163}, pmid = {4599970}, issn = {0005-3678}, mesh = {Antigens, Bacterial ; Bacteria/analysis/classification/*cytology/enzymology/growth &amp; development/immunology/metabolism ; Bacteriophages ; Conjugation, Genetic ; Cytoplasm ; DNA, Bacterial/analysis ; Electron Transport ; Flagella ; Genes ; Microscopy, Electron ; Microscopy, Phase-Contrast ; Mutation ; Nucleic Acid Hybridization ; Oxygen Consumption ; Paramecium/*cytology ; RNA, Bacterial/analysis ; RNA, Ribosomal/analysis ; *Symbiosis ; Toxins, Biological/biosynthesis ; }, }
@article {pmid4832979, year = {1974}, author = {Uzzell, T and Spolsky, C}, title = {Mitochondria and plastids as endosymbionts: a revival of special creation?.}, journal = {American scientist}, volume = {62}, number = {3}, pages = {334-343}, pmid = {4832979}, issn = {0003-0996}, mesh = {Animals ; Bacteria/cytology ; Biological Evolution ; DNA/analysis ; DNA, Mitochondrial/analysis ; Eukaryota/cytology ; Mice ; Mitochondria/*analysis ; Organoids/*analysis ; Rats ; *Symbiosis ; }, }
@article {pmid4605256, year = {1974}, author = {Gibson, I}, title = {The endosymbionts of Paramecium.}, journal = {CRC critical reviews in microbiology}, volume = {3}, number = {3}, pages = {243-273}, doi = {10.3109/10408417409108752}, pmid = {4605256}, issn = {0045-6454}, mesh = {Animals ; Bacteria/analysis/classification/cytology/*growth &amp; development/isolation &amp; purification/metabolism ; Bacterial Proteins/analysis ; Bacteriophages ; Cytoplasm ; DNA Viruses ; DNA, Bacterial/analysis ; Genes ; Microscopy, Electron ; Microscopy, Phase-Contrast ; Mutation ; Paramecium/*cytology ; RNA, Bacterial/analysis ; *Symbiosis ; }, }
@article {pmid4208322, year = {1974}, author = {Kies, L}, title = {[Electron microscopical investigations on Paulinella chromatophora Lauterborn, a thecamoeba containing blue-green endosymbionts (Cyanelles) (author's transl)].}, journal = {Protoplasma}, volume = {80}, number = {1}, pages = {69-89}, pmid = {4208322}, issn = {0033-183X}, mesh = {Chromatophores ; *Cyanobacteria/cytology ; Cytoplasm ; Eukaryota/*cytology ; Microscopy, Electron ; Microtubules ; Symbiosis ; }, }
@article {pmid4703195, year = {1973}, author = {Zaĭtseva, GN and Salikhov, TA}, title = {[Effect of chloramphenicol and cycloheximide on protein synthesis in the bipolar body (endosymbiont) of Strigomonas oncopelti cells].}, journal = {Izvestiia Akademii nauk SSSR. Seriia biologicheskaia}, volume = {2}, number = {}, pages = {252-259}, pmid = {4703195}, issn = {0002-3329}, mesh = {Animals ; Chloramphenicol/*pharmacology ; Cycloheximide/*pharmacology ; Eukaryota/*cytology/drug effects ; *Protein Biosynthesis ; Proteins/*pharmacology ; }, }
@article {pmid4633042, year = {1973}, author = {Gibson, I}, title = {Transplantation of killer endosymbionts in paramecium.}, journal = {Nature}, volume = {241}, number = {5385}, pages = {127-129}, pmid = {4633042}, issn = {0028-0836}, mesh = {Animals ; *Genetics, Microbial ; *Paramecium ; *Rickettsiaceae ; Symbiosis ; }, abstract = {SEVERAL syngens or breeding groups of Paramecium aurelia contain endosymbionts which may result in the development of the killer trait[1]. The symbionts are of different morphological types and it has been suggested that these are non-randomly distributed between syngens[2]. Experiments involving crosses between paramecia with and without symbionts showed that each endosymbiont required a specific nuclear gene for its maintenance. A single gene controlled the presence or absence of endosymbionts as shown by segregation in the F2 generation. The pattern of loss of symbionts in some of those F2 clones varies, generally extending over a number of asexual fissions which for different endosymbionts can be from two to over sixty. Infection experiments also demonstrate the requirement for a specific gene. Infection of endosymbionts from homogenates or purified preparations occurs via the medium but only into particular cells possessing a specific gene[1,3]. Finally, some endosymbionts growing in vitro retain their infectivity into certain paramecia (author's laboratory).}, }
@article {pmid4665127, year = {1972}, author = {Chinnarajan, AM and Jayaraj, S and Narayanan, K}, title = {Destruction of endosymbionts with oxytetracycline and sulphanilamide in the gourd fruitfly, Dacus cucurbitae Coq. (Trypetidae, Diptera).}, journal = {Hindustan antibiotics bulletin}, volume = {15}, number = {1}, pages = {16-22}, pmid = {4665127}, issn = {0018-1935}, mesh = {Adipose Tissue/drug effects ; Animals ; Bacteria/*drug effects ; Cell Count ; Diptera/*drug effects ; Epithelium/drug effects ; Female ; Hemolymph/cytology ; Intestines/drug effects ; Larva/drug effects ; Male ; Oxytetracycline/*pharmacology ; Pupa/drug effects ; Sulfanilamides/*pharmacology ; *Symbiosis ; }, }
@article {pmid5050962, year = {1972}, author = {Zaĭtseva, GN and Salikhov, TA}, title = {[Comparison of the ribosomes of cytoplasm and bipolar body (endosymbiont) in the cells of the zooflagellate Strigomonas oncopelti].}, journal = {Doklady Akademii nauk SSSR}, volume = {205}, number = {2}, pages = {457-460}, pmid = {5050962}, issn = {0002-3264}, mesh = {Animals ; *Cytoplasm ; Electrophoresis, Disc ; Eukaryota/*cytology ; RNA, Ribosomal ; *Ribosomes ; *Symbiosis ; }, }
@article {pmid5001940, year = {1971}, author = {Gibson, I and Chance, M and Williams, J}, title = {Extranuclear DNA and the endosymbionts of Paramecium aurelia.}, journal = {Nature: New biology}, volume = {234}, number = {46}, pages = {75-77}, doi = {10.1038/newbio234075a0}, pmid = {5001940}, issn = {0090-0028}, mesh = {Autoradiography ; Base Sequence ; Centrifugation, Density Gradient ; DNA/*analysis ; Nucleic Acid Hybridization ; Paramecium/*analysis ; RNA/analysis ; Rickettsiaceae/*analysis ; Tritium ; }, }
@article {pmid4901086, year = {1969}, author = {Beale, GN and Jurand, A and Preer, JR}, title = {The classes of endosymbiont of Paramecium aurelia.}, journal = {Journal of cell science}, volume = {5}, number = {1}, pages = {65-91}, doi = {10.1242/jcs.5.1.65}, pmid = {4901086}, issn = {0021-9533}, mesh = {Animals ; Bacteria/*metabolism ; Cell Membrane ; Cell Nucleus ; Cytoplasm ; Endoplasmic Reticulum ; Flagella ; Microscopy, Electron ; Microscopy, Phase-Contrast ; Mutation ; Paramecium/*metabolism ; Species Specificity ; *Symbiosis ; Toxins, Biological/biosynthesis ; }, }
@article {pmid4973484, year = {1968}, author = {Pratt, WB and Gross, SR and Aronow, L}, title = {Endosymbionts as a source of cytoplasmic satellite deoxyribonucleic acid.}, journal = {Journal of molecular biology}, volume = {33}, number = {2}, pages = {521-525}, doi = {10.1016/0022-2836(68)90211-8}, pmid = {4973484}, issn = {0022-2836}, mesh = {Animals ; Cell Nucleolus/analysis ; Cell Nucleus/analysis ; Centrifugation, Density Gradient ; Cytoplasm ; DNA/*analysis ; Densitometry ; Deoxyribonucleases ; Fibroblasts ; Mice ; Mitochondria/analysis ; *Mycoplasma ; *Rickettsiaceae ; }, }